Biomedical subjects
Publications and source records attributed to M Almeida.
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Androgens are considered to have immunomodulatory effects but their cellular mechanisms of action remain largely unknown. In the present study we prospectively analyzed the serial effects of androgen-replacement therapy on both the distribution of peripheral blood lymphocytes, monocytes and dendritic cells as well as on the production of interleukin (IL)-1beta, IL-6 and tumor necrosis factor alpha (TNFalpha) inflammatory cytokines by circulating monocytes and CD33 myeloid, CD16 and plasmacytoid dendritic cell subsets, the most potent antigen-presenting cells (APCs) in type-2 diabetic men with partial androgen deficiency. Analyses were performed before therapy and at 1, 3, 6 and 12 months after treatment with 150 mg testosterone enanthate every 2 weeks in a group of 13 type-2 diabetic men. Our results show for the first time that testosterone-replacement therapy is associated with a reduction or complete abrogation of spontaneous ex vivo production of IL-1beta, IL-6 and TNFalpha by APCs. Meanwhile, the in vitro production of inflammatory cytokines by these cells after stimulation with lipopolysaccharide plus recombinant human interferon-gamma remained unchanged, suggesting that APCs preserve their constitutive machinery to produce inflammatory cytokines under androgen treatment. These results confirm and extend previous observations about the anti-inflammatory effects of androgen therapy on APCs in a new, previously unexplored model of androgen deficiency; namely, aging type-2 diabetic men. A decreased production of inflammatory cytokines by APCs might have important consequences for sex differences in susceptibility to autoimmune diseases, inflammatory response to injury and atheromatosis.
Elucidation of kinase-initiated routes by which the estrogen receptors alpha and beta (ERalpha and ERbeta) control gene transcription, along with evidence of distinct biologic outcomes in response to ligands that can selectively activate nongenotropic signaling of the ERs or the androgen receptor, suggest that the ERs control a range of genes wider than that regulated by their direct association with DNA. To ascertain the extent and significance of nongenotropic ER-mediated transcription, we employed transduced HeLa cells expressing wild-type ERalpha or the ligand binding domain of ERalpha localized to the cell membrane (E-Mem), the OB-6 osteoblastic cell line, MCF-7 breast carcinoma cells and uteri from mice treated with 17beta-estradiol (E(2)), or the nongenotropic signaling activator 4-estren-3alpha,17beta-diol (estren). E(2) and estren induced ERK1/2 and Akt phosphorylation in ERalpha or E-Mem stably transfected HeLa cells; however, the phosphorylation kinetics differed between the two cell lines. In all four models, nongenotropic ER actions regulated a population of genes distinct from those regulated by genotropic ER actions. Specifically, the expression of Wnt2, Frizzled10, Egr-1, and c-Fos was strongly up-regulated in E-Mem-containing HeLa cells treated with E(2) or estren, or in ERalpha-containing HeLa cells treated with estren. Up-regulation of Frizzled10 by estren was reproduced in MCF-7 cells. Egr-1 was up-regulated by both estren and E(2); but complement 3, only by E(2) in the uteri. Estren had no effect on complement 3, cathepsin D, progesterone receptor, bcl-2, and cyclin D1 in MCF-7 cells, whereas E(2) up-regulated all these estrogen response element or activating protein-1-containing genes. These results support an extensive divergence in gene expression depending on the mode of ER activation.
Acute renal artery occlusion is rarely found in daily clinical practice. Its rarity and inespecific clinical presentation are responsible for late diagnosis or diagnostic errors, with symptoms frequently being erroneously attributed to other more common entities. There is no consensus in what concerns therapeutic options. Multiple treatment modalities are described in the available literature. Some defend anticoagulant therapy and support measures only while others recommend other more invasive alternatives reaching even open surgery. The authors present two additional case reports of acute embolic renal ischemia. A thorough literature review is also presented comprehending etiological, clinic, diagnostic and therapeutic aspects.
The quasi-one-dimensional organic conductor (Per)2Pt(mnt)2 exhibits a charge density wave ground state below 8 K. Magnetoresistance and magnetization measurements show that the charge density wave is suppressed with magnetic fields of order 20 T, above which a high resistance state, with a cascade of subphases, appears. This new state, tentatively identified as a field induced charge density wave, reenters a low resistance state above 40 T. The results are presented in light of theoretical work [D. Zanchi et al. Phys. Rev. B 53, 1240 (1996)]] involving field induced charge density wave ground states in high magnetic fields.
OBJECTIVE: This study was undertaken to evaluate the subjective success rates, and complications, of Burch colposuspension. DESIGN: A retrospective review. SAMPLE: Fortynine women undergoing surgery - Burch colposuspension - for genuine stress incontinence, between 1994 and 2000, were reviewed. METHODS: Choice of surgical procedure was made on the basis of clinical and urodynamic findings and physician preference. The subjective cure rate was determined by means of historical report and defined as no or occasional stress or urge incontinence (< one episode per week). Clinical follow-up started six weeks after the surgical procedure and continued for one to seven years. RESULTS: Thirty-six (73.5%) of the 49 women submitted to Burch colposuspension were subjectively cured of the stress urinary incontinence and three (6,1%) had improvement with mainly urge incontinence, while ten (19.2%) operations failed (n= 52). CONCLUSION: Burch colposuspension is an effective and safe procedure for women with urinary stress incontinence (even after retropubic continence surgery).
Aging in the male is associated with both a higher incidence of type 2 diabetes and hypogonadism. However, little information is available about the complex of symptoms and hormonal changes related to partial androgen deficiency in aging (called andropause) in type 2 diabetic men. Here, for the first time, we used a combination of clinical and hormonal criteria to define andropause and to analyze the relationships between the androgen environment and glucose metabolism in 55 type 2 diabetic men (63.6 +/- 7.9 years, mean +/- SD). Low plasma levels of total testosterone (< or =3.4 ng/mL) and free testosterone (< or =11 pg/mL) were found in 20% and 54.5%, respectively, of the diabetic men. The fraction of diabetic men with subnormal levels of total testosterone increased with aging: 14.2% (50 to 59 years), 17.4% (60 to 69 years) and 36% (> 70 years). The corresponding figures for subnormal values of free testosterone were 38%, 69.6%, and 54.5%, respectively. In the whole group of type 2 diabetic men, no significant linear correlations between total or free testosterone with fasting plasma glucose, insulin, C-peptide, or fructosamine values could be established. Total testosterone was positively correlated with glycosylated haemoglobin (HbA(1c)) levels (r =.322, P =.01). Although fasting plasma glucose was marginally higher in aging type 2 diabetic patients with andropause than in those without andropause (162 +/- 6.9 v 139 +/- 8.9, mean +/- SEM, P =.05), there were no differences between both subgroups for plasma fasting insulin, C-peptide, fructosamine, or HbA(1c) levels. Replacement therapy (150 mg intramuscular [IM] of enanthate of testosterone every 14 days for 6 months) was applied in 10 type 2 diabetic men with clinical features of andropause associated with subnormal concentrations of serum testosterone. The treatment induced significant increases in total plasma testosterone (baseline: 3.9 +/- 0.3; at 6 months: 7.1 +/- 0.9 ng/mL, mean +/- SEM, P =.003) and free testosterone (baseline: 9.3 +/- 0.6; at 6 months 17.6 +/- 2.4 pg/mL, P =.003), but had a neutral effect on overall glycemic control. These data show a high prevalence of andropause in aging type 2 diabetic men and suggest that the endogenous androgen environment, as well as correction of the partial androgen deficiency, do not have a meaningful effect on glycemic control.
Characteristics of wastewater vary during transportation through sewer systems as a result of a number of processes. Under aerobic conditions, in long sewer systems, the reduction of the BOD or COD may be similar to the reduction obtained in conventional primary settling tanks. The mathematical model that was developed is based on a number of different existing models: the ASM n. 1 and ASM n. 2 models, the AEROSEPT model and the WATS model. The model also includes a prediction of reaeration at falls. The module of the anoxic conditions was adapted from the ASM n. 2 model. This module is a first attempt to model the degradation of organic matter in sewer systems under anoxic conditions. The mathematical model was applied to the Costa do Estoril intercepting sewer, and the obtained results are discussed taken into account the experimental data that was collected during a three-month period. Average removals of dissolved COD over 20% have been obtained. In the paper special emphasis is given to the importance of the performance of the Costa do Estoril sewer system as a biological reactor.
The aim of this study is to characterize the influence of organic dispersants on the stability of hydroxyapatite (HAP) dispersions, using viscosity measurements, electrokinetic sonic amplitude (ESA) measurements and adsorption isotherms. Colloidal stability of aqueous suspensions of HAP as a function of solids loading and of the type and concentration of deflocculant has been studied. The interaction between particles and dispersant molecules was characterized. Adsorption measurements of the amount of dispersants on the particles surface, viscosity and electrophoretic measurements as a function of the dispersant concentration are correlated. Suspension parameters have been adjusted in order to obtain a high solids loading slurry with a plastic viscosity which will allow its use in colloidal processing.
The gold complexes n-Bu4N[Au(alpha-tpdt)2] (5), n-Bu4N[Au(dtpdt)2] (4) and n-Bu4N[Au(tpdt)2] (6) based on new dithiothiophene ligands (alpha-tpdt= 2,3-thiophenedithiolate, dtpdt=2,3-dihydro-5,6-thiophenedithiolate and tpdt = 3,4-thiophenedithiolate) have been prepared and characterised. These gold(III) complexes are diamagnetic, but they can be oxidised with iodine to the paramagnetic compounds [Au(alpha-tpdt)2] (8), [Au(dtpdt)2] (7) and n-Bu4N[[Au(tpdt)2]n-2] (9), which were isolated as fine powders and which exhibit paramagnetic susceptibilities that are almost temperature independent with room temperature values of 2.5 x 10(-4), 2.0 x 10(-4) and 5 x 10(-4) emu x mol(-1), respectively. Interestingly, the neutral complex [Au(alpha-tpdt)2] (8) as a polycrystalline sample displays the properties of a metallic system with a room temperature electrical conductivity of 6 S x cm(-1) and a thermoelectric power of 5.5 microVK(-1); this is the first time that this metallic property has been observed in a molecular system based on a neutral species.
Vanadium haloperoxidases were extracted, purified and characterized from three different species of Laminariaceae--Laminaria saccharina (Linné) Lamouroux, Laminaria hyperborea (Gunner) Foslie and Laminaria ochroleuca de la Pylaie. Two different forms of the vanadium haloperoxidases were purified from L. saccharina and L. hyperborea and one form from L. ochroleuca species. Reconstitution experiments in the presence of several metal ions showed that only vanadium(V) completely restored the enzymes activity. The stability of some enzymes in mixtures of buffer solution and several organic solvents such as acetone, ethanol, methanol and 1-propanol was noteworthy; for instance, after 30 days at least 40% of the initial activity for some isoforms remained in mixtures of 3:1 buffer solution/organic solvent. The enzymes were also moderately thermostable, keeping full activity up to 40 degrees C. Some preliminary steady-state kinetic studies were performed and apparent Michaelis-Menten kinetic parameters were determined for the substrates iodide and hydrogen peroxide. Histochemical studies were also performed in fresh tissue sections from stipe and blade of L. hyperborea and L. saccharina, showing that haloperoxidase activity was concentrated in the external cortex near the cuticle, although some activity was also observed in the inner cortical region.
Hydroxytyrosol acetate was synthesized, and the antioxidant activity of this olive oil component was assessed in comparison with that of other olive oil components, namely hydroxytyrosol, oleuropein, 3,4-DHPEA-EA, and alpha-tocopherol in bulk oil and oil-in-water emulsions. The activity of the compounds was also assessed by scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Hydroxytyrosol acetate had a weaker DPPH radical scavenging activity than hydroxytyrosol, oleuropein, or 3,4-DHPEA-EA but it had a radical scavenging activity similar to that of alpha-tocopherol. In oil, the antioxidant activity of hydroxytyrosol acetate was much higher than that of alpha-tocopherol or oleuropein, but in an emulsion 3,4-DHPEA-EA and alpha-tocopherol were more effective as antioxidants than hydroxytyrosol acetate. The antioxidant activity of hydroxytyrosol acetate was rather similar to that of hydroxytyrosol in oil and emulsions despite the difference in DPPH radical scavenging activity.
Hereditary nonpolyposis colorectal cancer syndrome (HNPCC) is an autosomal dominant condition accounting for 2-5% of all colorectal carcinomas as well as a small subset of endometrial, upper urinary tract and other gastrointestinal cancers. An assay to detect the underlying defect in HNPCC, inactivation of a DNA mismatch repair enzyme, would be useful in identifying HNPCC probands. Monoclonal antibodies against hMLH1 and hMSH2, two DNA mismatch repair proteins which account for most HNPCC cancers, are commercially available. This study sought to investigate the potential utility of these antibodies in determining the expression status of these proteins in paraffin-embedded formalin-fixed tissue and to identify key technical protocol components associated with successful staining. A set of 20 colorectal carcinoma cases of known hMLH1 and hMSH2 mutation and expression status underwent immunoperoxidase staining at multiple institutions, each of which used their own technical protocol. Staining for hMSH2 was successful in most laboratories while staining for hMLH1 proved problematic in multiple labs. However, a significant minority of laboratories demonstrated excellent results including high discriminatory power with both monoclonal antibodies. These laboratories appropriately identified hMLH1 or hMSH2 inactivation with high sensitivity and specificity. The key protocol point associated with successful staining was an antigen retrieval step involving heat treatment and either EDTA or citrate buffer. This study demonstrates the potential utility of immunohistochemistry in detecting HNPCC probands and identifies key technical components for successful staining.
Previous studies carried out with Sm14 in experimental vaccination against Schistosoma mansoni or Fasciola hepatica infections were performed with recombinant Sm14 (rSm14) produced in Escherichia coli by the pGEMEX system (Promega). The rSm14 was expressed as a 40 kDa fusion protein with the major bacteriophage T7 capsid protein. Vaccination experiments with this rSm14 in animal models resulted in consistent high protective activity against S. mansoni cercariae challenge and enabled rSm14 to be included among the vaccine antigens endorsed by the World Health Organization for phase I/II clinical trials. Since the preparation of pGEMEX based rSm14 is time consuming and results in low yield for large scale production, we have tested other E. coli expression systems which would be more suitable for scale up and downstream processing. We expressed two different 6XHis-tagged Sm14 fusion proteins in a T7 promoter based plasmids. The 6XHis-tag fusions allowed rapid purification of the recombinant proteins through a Ni+2-charged resin. The resulted recombinant 18 and 16 kDa proteins were recognized by anti-Sm14 antibodies and also by antiserum against adult S. mansoni soluble secreted/excreted proteins in Western-Blot. Both proteins were also protective against S. mansoni cercariae infection to the same extent as the rSm14 expressed by the pGEMEX system.
INTRODUCTION: Stents are being used with increasing frequency in percutaneous transluminal coronary angioplasty (PTCA) but their use in small vessels is still controversial, due to the possibility of excessively high rates of adverse events and restenosis. OBJECTIVE: To assess the safety and clinical efficacy of ACS RX Multi-Link (ML) 2.5 mm stents, in "de novo" coronary stenosis. DESIGN: Prospective Registry, with 6 months clinical follow-up, involving all Portuguese centers of Interventional Cardiology. POPULATION: Between April 7 and November 20 1998, 102 patients were enrolled, 82 male and with ages ranging from 30 to 86 years (average 58 +/- 11). Clinical presentation for PTCA was stable angina in 53%, unstable angina in 36% and silent ischemia in 11%. There was a history of previous myocardial infarction in 29% of patients. The main risk factors were hypertension (58%), hyperlipidemia (57%), smoking (25%) and diabetes (20%). Multivessel coronary artery disease was present in 46% of patients and left ventricular function was normal in 89%. Of the 217 existing lesions, 188 (87%) were treated: 35 with balloon angioplasty and 153 with stent implantation, 114 of which were ML 2.5 mm: 79 of 15 mm in length and 35 of 25 mm. METHODS: Angiographic success with ML stent implantation and major adverse cardiac events (MACE)--myocardial infarction (MI), coronary artery bypass graft (CABG), new target vessel revascularizations and death--were evaluated during hospital stay, and at 1 and 6 months clinical follow-up. RESULTS: Angiographic success was 97.4%. In one patient it was not possible to cross the lesion, in another there was stent migration and in a third distal coronary flow after stenting was TIMI grade 1. Clinical success was 96.1% and there were no cases of death, Q-wave MI or urgent CABG. Two patients had non-Q wave MI and two required urgent repeat angioplasty. Subacute stent thrombosis occurred in 1 patient. There were no additional MACE at 1 month follow-up. At 6-month follow-up (in 97% of patients) MACE had occurred in 14.1%: 2 deaths (one non-cardiac), 3 MI (one non-Q) and 14 new PTCA (one in a non-ML stent). There was no need for CABG in any patient. Six-month survival rate was 97.9%, 94.9% were free of infarction and 84.8% were free of infarction and new revascularization. CONCLUSIONS: Multi-Link 2.5 mm stent implantation appears to be safe and efficient with a low incidence of immediate and 6-month adverse events in the range of centers and operators of the Registry.
INTRODUCTION: The restenosis rate of stents implanted into small coronary arteries is considered higher than that of stents in arteries > or = 3 mm, but could be influenced by clinical parameters and by the type and length of the stents. OBJECTIVE: To assess the incidence of angiographic restenosis at 6 months after implantation of 2.5 mm ACS RX Multi-Link (ML) stents, 15 and 25 mm length, in de novo coronary stenosis. DESIGN: Angiographic substudy of the Portuguese Multi-Link 2.5 Registry, which included Interventional Cardiology centers with facilities for coronary angiographic recordings allowing quantitative analysis. POPULATION: Between April 7 and November 20 1998 and in the 5 hospitals that agreed to participate, 61 patients were enrolled and 40 selected as having procedural and 6-month angiographies of sufficient quality for quantitative analysis. The only significant differences in the demographic, clinical and angiographic characteristics of the patients relative to those of the Registry were the lower prevalence of unstable angina and smoking in the angiographic substudy. There were 43 lesions and 46 ML stents were implanted. In 37% the lesions were located in the LAD, in 37% in the LCx and 26% in the RCA. 29 stents of 15 mm length and 17 stents of 25 mm were used. METHODS: The morphologic characteristics of the lesions were analyzed subjectively using the AHA/ACC classification. Quantitative coronary analysis (QCA) was performed, in an independent laboratory using the CAAS 2 system, for reference vessel diameter, lesion length, percentage of stenosis, minimum lumen diameter (MLD) and related parameters. Restenosis was defined as > or = 50% lumen obstruction at 6-month angiography. RESULTS: In the subjective analysis, 2 lesions were type B1, 27 type B2 and 14 type C. The overall restenosis rate was 32.6%. Restenosis was 27.7% for 15 mm stents and 36% for 25 mm stents (p = 0.4). For the QCA parameters analyzed, only MLD at the end of stent implantation was a predictor of 6-month restenosis (2.19 +/- 0.30 without vs. 2.03 +/- 0.18 with restenosis, p = 0.048). CONCLUSIONS: The restenosis rate of the Multi-Link 2.5 mm stents, of 15 and 25 mm length, was similar to that described with other types of stents in small coronary arteries. Minimum lumen diameter after stenting was found to be the best predictor of 6-month restenosis.
The authors report a case study of a 73-year-old male, with signs of right-sided heart failure with 6 months of evolution. It was constrictive pericarditis, without radiologic, echocardiographic and magnetic resonance imaging manifestations, diagnosed on the basis of the clinical situation and hemodynamic evaluation during cardiac catheterization. The authors suggest that the lack of imagiologic manifestations might have been the result of an early diagnosis, before the development of the classic picture. Pericardiectomy, performed with success, was followed by resolution of the heart failure. It was not possible, histologically, to draw conclusions about the etiology. The development of mitral regurgitation after pericardiectomy has enriched this case with an unusual, but previously described, complication of this type of surgery.
To understand the basis for the clinical heterogeneity of phenylalanine hydroxylase deficiency among Portuguese hyperphenylalaninemic patients, genotype-phenotype correlations were established. A group of 61 patients was completely genotyped, leading to the identification of 20 different mutant alleles in 36 different genotypic combinations, including a mutant allele not reported previously. The severity of those mutations found within this hyperphenylalaninemic population, which have not been previously expressed in vitro, were assessed. The results obtained by the present study exhibit a strong correlation between the predicted residual enzyme activity, as deduced from the genotype of the patients, and the biochemical phenotype represented by the diagnostic parameters (phenylalanine levels before the beginning of treatment and the dietary phenylalanine tolerance). It was observed that only a judicious follow-up and compliance with the appropriate diet permits the correct assessment of the clinical phenotype of the patients. Additionally, based upon the correlation observed between genotypes and diagnostic parameters, it was possible to predict the potential residual enzyme activity of those mutations (identified in our patients) which have not yet been studied in vitro.