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Biomedical subjects

H Pereira

Publications and source records attributed to H Pereira.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of a compost obtained from forestry wastes and solid phase of pig slurry as a substrate for seedlings production.

A composted material obtained from forestry wastes and solid phase of pig slurry was evaluated as a substrate component for the production of tomato and lettuce seedlings. Four different substrates were tested: compost (100C), a mixture of 75% compost and 25% peat substrate (75C), a mixture of 50% compost and 50% peat substrate (50C), and peat-based substrate (control). Compost increased the pH of the substrate from 6.3 (control) to 6.9 (100C) but did not affect the electrical conductivity (0.26 and 0.27 mScm(-1), respectively, for control and 100C). Germination and growth of lettuce seedlings were not affected by the substrate type, contrasting with tomato seedlings where the highest growth occurred at 100C substrate. Increasing compost percentage on substrate increased nitrogen, calcium and magnesium availability and, consequently, the concentration of these elements in plant tissues increased. On the contrary, potassium and manganese concentration decreased. Results from the study suggest that the compost studied is a good alternative to peat-based substrates for the production of vegetable seedlings.

Animals↗
PubMed2006

Supplementation requirements of brewery's spent grain hydrolysate for biomass and xylitol production by Debaryomyces hansenii CCMI 941.

The effect of nutrient supplementation of brewery's spent grain (BSG) hydrolysates was evaluated with respect to biomass and xylitol production by Debaryomyces hansenii. For optimal biomass production, supplementation of full-strength BSG hydrolysates required only phosphate (0.5 g l(-1) KH(2)PO(4)), leading to a biomass yield and productivity of 0.60 g g(-1) monosaccharides and 0.55 g l(-1 )h(-1), respectively. Under the conditions studied, no metabolic products other than CO(2) and biomass were identified. For xylitol production, fourfold and sixfold concentrated hydrolysate-based media were used to assess the supplementation effects. The type of nutrient supplementation modulated the ratio of total polyols/total extracellular metabolites as well as the xylitol/arabitol ratio. While the former varied from 0.8 to 1, the xylitol/arabitol ratio reached a maximum value of 2.6 for yeast extract (YE)-supplemented hydrolysates. The increase in xylitol productivity and yield was related to the increase of the percentage of consumed xylose induced by supplementation. The best xylitol yield and productivity were found for YE supplementation corresponding to 0.55 g g(-1) and 0.36 g l(-1 )h(-1), respectively. In sixfold concentrated hydrolysates, providing that the hydrolysate was supplemented, the levels of xylitol produced were similar or higher than those for arabitol. Xylitol yield exhibited a further increase in the sixfold hydrolysate supplemented with trace elements, vitamins and minerals to 0.65 g g(-1), albeit the xylitol productivity was somewhat lower. The effect of using activated charcoal detoxification in non-supplemented versus supplemented sixfold hydrolysates was also studied. Detoxification did not improve polyols formation, suggesting that the hemicellulose-derived inhibitor levels present in concentrated BSG hydrolysates are well tolerated by D. hansenii.

Alcoholic Beverages↗
PubMed2004

Arundo donax L. reed: new perspectives for pulping and bleaching. Part 4. Peroxide bleaching of organosolv pulps.

A comparative study on TCF (totally chlorine-free) bleachability of organosolv pulps from the annual fibre crop Arundo donax L. (giant reed) was carried out using a simple three-stage peroxide bleaching sequence without oxygen pre-bleaching. ASAM (alkali-sulfite-anthraquinone-methanol), Organocell (alkali-anthraquinone-methanol) and ethanol-soda organosolv pulps were bleached and compared with kraft pulp, as a reference. The final brightness of 76-78% ISO was attained for all tested pulps. The chemical charge required to reach this level of brightness varied for different pulps (despite the equal initial content of the residual lignin) and directly related to starting brightness values. No direct correlation between brightness improvement and lignin removal during bleaching was found, indicating the influence of the specific pulp properties introduced by pulping process on bleaching chemistry. The general higher bleaching response of organosolv pulps from A. donax was noted in comparison with kraft.

Biodegradation, Environmental↗
PubMed2004

Secretory breast carcinoma--case report and review of the medical literature.

Secretory breast carcinoma (SBC) is a rare type of invasive breast cancer. Since little is known about the biology of this rare tumour, it is useful to report every such case, in order to make as much information as possible available in the medical literature. We present the case of an 18-year-old woman with a SBC treated by mastectomy (Madden) and axillary node dissection (stage pT3N1M0) followed by chemotherapy (FEC regimen) and radiotherapy. The patient has meanwhile completed 4 years of follow-up with no evidence of recurrence. The authors review the literature and summarize relevant findings concerning definition, pathology, clinical picture, treatment, and follow-up.

Adolescent↗
PubMed2004

Production of oligosaccharides by autohydrolysis of brewery's spent grain.

Brewery's spent grain was treated with water in a process oriented towards the production of xylo-oligosaccharides (XOS). A wide range of temperatures and reaction times were tested and the effects of these operational variables on hemicellulose solubilization and reaction products were investigated. The maximal XOS yield (61% of the feedstock xylan) was obtained at 190 degrees C after 5 min of reaction. Several oligosaccharide mixtures with different molecular weight distributions were obtained depending on temperature and reaction time. Longer reaction times led to decreased oligosaccharide production and enhanced concentrations of monosaccharides, sugar decomposition products and acetic acid. With reaction times leading to the maximal yields of XOS, little decomposition into organic acids and aldehydes was found at all the temperatures assayed. From the composition of processed solids, it was calculated that 63-77% of the initial xylan was selectively solubilized in autohydrolysis treatments.

Hordeum↗
PubMed2001

[Changes in regional wall contractility induced by effort in women with normal coronary angiography --report of a clinical case].

The diagnosis of coronary artery disease in women has been thought to be more difficult than in men, owing to the lower overall prevalence of disease in women, as well as more subtle clinical presentations and unspecific changes in ST segment. The authors report a clinical case of a 61-year old woman, with low cardiovascular risk and history of atypical chest pain and a positive treadmill exercise test on the inferior leads. She did an exercise echocardiogram that revealed severe hypokinesis on the anterior wall and septum with late normalization. The patient was submitted to a coronary angiography that revealed normal arteries. An echocardiogram with hyperventilation was later performed and showed the same ischemic changes as exercise did, on the inferior leads but no regional wall motions abnormalities occurred. The patient is currently asymptomatic under calcium antagonist treatment.

Coronary Angiography↗
PubMed2001

Atropine in exercise stress echocardiography? Case report.

Stress echocardiography is widely used in the investigation of coronary heart disease. Exercise stress echocardiography offers the advantage of visualizing myocardial motion abnormalities during physiological stress testing. The authors report the use of atropine, as an adjunct to exercise echocardiography, in risk stratification after myocardial infarction.

Atropine↗
PubMed2001

Use of stents for small coronary arteries. Results of the Multi-Link 2.5 Portuguese Registry.

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.

Adult↗
PubMed2001

Results of the quantitative coronary angiographic analysis in the angiographic subgroup of the Multi-Link 2.5 Portuguese 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.

Coronary Angiography↗
PubMed2000

Suberin structure in potato periderm: glycerol, long-chain monomers, and glyceryl and feruloyl dimers.

Suberin in extractive-free potato periderm amounts to approximately 25% determined by NaOCH(3) methanolysis. Monomeric composition is characterized by glycerol (20% of monomers), long-chain alpha, omega-diacids, omega-hydroxyacids, alkanoic acids, and alkan-1-ols, with predominance of octadec-9-enodioic acid and 18-hydroxyoctadec-9-enoic acid (39 and 15% of long-chain monomers, respectively). Aromatic hydroxycinnamyl monomers were also present (<1%). Partial depolymerization of potato periderm suberin using a Ca(OH)(2)-catalyzed methanolysis solubilized approximately 10% of suberin aliphatics. GC-MS analysis showed the presence of monomers, dimers, and trimers (87, 12, and 1% of identified compounds, respectively). A total of 26 dimers were identified by EIMS: monoacylglyceryl esters of alpha,omega-diacids, omega-hydroxyacids, and alkanoic acids (with predominance of the 1- and 2-isomers of the monoacylglyceryl ester of the octadec-9-enodioic acid), as well as feruloyl esters of omega-hydroxyacids and alkan-1-ols and a small quantity of a monoferuloylglycerol. Following a discussion of suberin macromolecular structure, it is proposed that in suberized cell walls, the polyaliphatic polymers have a three-dimensional development ensured by glycerol and exist independently from the associated polyaromatics.

Carboxylic Acids↗
PubMed2000

Cardiac rupture during exercise stress echocardiography: a case report.

Stress echocardiography is widely used in the evaluation of coronary artery disease. Dobutamine stress echocardiography has been the preferred method, but many centers have adopted exercise stress echocardiography, which can visualize myocardial motion during physiologic stress testing. The complications of this method in the post-myocardial infarction period are the same as those identified in conventional exercise testing. We report a case of myocardial rupture in the postinfarction period during exercise stress echocardiography.

Aged↗
PubMed2000

[Plasma total anti-oxidant status in young survivors of myocardial infarction].

UNLABELLED: Free oxygen radicals are involved in the endothelial lesion process which leads to the formation of the atheroma plaque and thrombosis. There is some evidence that antioxidant therapy may be beneficial in coronary heart disease prevention. Our objective was to study the plasma total anti-oxidant status in young survivors of acute myocardial infarction. POPULATION: 23 patients, mean age 35.2 years (22-40) admitted for acute myocardial infarction from January 1995 to June 1998 (20 males). RISK FACTORS: Tobacco smoking 22/23, systemic arterial hypertension 4/23, hypercholesterolemia 17/23, positive family history for coronary heart disease 5 patients, previous history of angina 4 patients, none of these patients had diabetes mellitus. The location of the infarct was anterior in 12 patients, inferior in 10 patients and non-Q wave in one patient. Blood samples were drawn after overnight fasting and the plasma total antioxidant status (TAS) was determined by a colorymethric method (Trolox equivalent). The mean time elapsed since the acute myocardial infarction until sample collection was 16.5 +/- 10.7 months. RESULTS: 18 patients had low TAS values, mean 1.23 +/- 0.11 mmol/L (below the reference values: 1.3-1.77 mmol/L). CONCLUSIONS: In this group of patients, the plasma total antioxidant capacity was globally decreased, which may constitute a risk factor for coronary heart disease.

Adult↗
PubMed2000

[Non-infectious thrombotic endocarditis: a case report].

A 48 year-old female patient, admitted with an ischemic stroke, had a transesophageal echocardiogram (TEE) that revealed a dense vegetation in the noncoronary aortic cusp, which was considered the probable source of embolism. The clinical investigation did not identify any other disease or infectious process. However the lack of histologic proof, the absence of fever, the fact that the blood cultures were persistently negative, the patient recovery with no need of antibiotics, and the results of the TEE, are highly suggestive of the presence of a non infectious thrombotic endocarditis. After 18 months of anti-platelet treatment, the patient showed no new embolic episodes and TEE demonstrated the resolution of the vegetation.

Echocardiography, Transesophageal↗