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Biomedical subjects

H Morais

Publications and source records attributed to H Morais.

11 recordsLinked to original sources
PubMed2002

Effect of ascorbic acid on the stability of beta-carotene and capsanthin in paprika (Capsicum annuum) powder.

The effect of ascorbic acid, light, and storage on the stability of the pigments beta-carotene and capsanthin in red pepper (Capsicum annuum) powder has been elucidated by determining the amount of pigment in samples treated by various concentrations of ascorbic acid. Determination of pigment concentration has been performed after different storage times using high-performance liquid chromatography. The dependence of the concentration of pigments on the concentration of ascorbic acid, presence of light and the storage time has been assessed by stepwise regression analysis. The concentration of pigments decreased at longer storage time and increased at higher concentration of ascorbic acid, beta-carotene being more sensitive towards storage time and concentration of ascorbic acid than capsanthin. Interaction between the effects of light and storage time, and light and concentration of ascorbic acid has been established.

Antioxidants↗
PubMed2001

Effects of fluorescent light and vacuum packaging on the rate of decomposition of pigments in paprika (Capsicum annuum) powder determined by reversed-phase high-performance liquid chromatography.

The effect of storage time, the presence of light and oxygen on the decomposition rate of carotenoid pigments in paprika (Capsicum annuum) powders was determined by reversed-phase high-performance liquid chromatography (RP-HPLC). The similarities and dissimilarities of pigment composition of samples under various storage conditions was elucidated by principal component analysis (PCA) and stepwise regression analysis (SRA). Calculations proved that the overall decomposition rate of pigment sections equally depended on the storage time and on the presence of light and oxygen, the effect of storage time being the most decisive factor while the impact of oxygen was the lowest. The selectivity of decomposition also depended on the storage time and on the presence of oxygen the influence of storage time being the most important. RP-HPLC followed by PCA and SRA can be successfully used for the study of the impact of environmental conditions on the decomposition of carotenoid pigments of paprika powders.

Capsicum↗
PubMed2001

Profiling of colour pigments of chili powders of different origin by high-performance liquid chromatography.

The colour pigments of five chili powders of different origins were separated and quantified by reversed-phase high-performance liquid chromatography (RP-HPLC). The similarities and dissimilarities of pigment composition of chili powders were elucidated by principal component analysis (PCA). RP-HPLC separated 50-100 pigment fractions depending on the detection wavelength and on the origin of chili powder. It was found that the pigment composition of chili powders from Malaysia and China and from India and Pakistan show marked similarities while the composition of colour pigments of chili powder from Thailand was different. It was further established that the chromatograms are similar in the first 5-35 min of development, they are highly different between 35 and 75 min and moderately different at the end of the chromatograms. It was concluded that RP-HPLC followed by PCA can be successfully used for the identification of chili powders according to the composition of their colour pigments.

Capsicum↗
PubMed2000

Classification of chili powders by thin-layer chromatography and principal component analysis.

Silica gel, aluminium oxide, diatomaceous earth, polyamide, cyano, diol and amino plates have been tested for their capacity to separate the color pigments of six chili powders of different origin by both adsorption and reversed-phase thin-layer chromatography. The plates were evaluated at 340 and 440 nm wavelengths. Best separation of color pigments was obtained on impregnated diatomaceous earth layer using acetone-water 17:3 v/v eluent. It was found that the pigment composition of chili powders showed marked differences. Principal component analysis employed for the classification of the chili powders according to their pigment composition indicated that these differences can be used for the determination of the similarity or dissimilarity of the chili powders.

Capsicum↗
PubMed2000

Optimisation of the microwave-assisted extraction of pigments from paprika (Capsicum annuum L.) powders.

The efficiency of microwave-assisted extraction (MAE) for the extraction of colour pigments from paprika (Capsicum annuum) powders was evaluated using 30 extracting solvent mixtures. The separation efficacy and selectivity of MAE was carried out using a spectral mapping technique and the relationship between the efficacy and selectivity of extraction and the physicochemical parameters of solvent mixtures was calculated by stepwise regression analysis. The calculation results were verified experimentally by the separation of pigment fractions by high-performance liquid chromatography. It was established that both the efficacy and selectivity of MAE depend significantly on the dielectric constant of the extraction solvent mixture.

Capsicum↗
PubMed2000

Tissue Doppler imaging in different locations of the mitral annulus: all different or all the same?

BACKGROUND: The assessment of the mitral annulus motion with tissue Doppler imaging is claimed to be an accurate method to quantify global left ventricular systolic and diastolic function. However, it is not yet perfectly defined which site of the annulus must be selected. Familial amyloidotic polyneuropathy of the Portuguese type (FAP) is an hereditary systemic disease in which diastolic dysfunction may occur. AIM: 1--To determine if in FAP patients the mitral annulus motion is independent of the selected site. 2--To compare pulsed wave Doppler parameters with tissue Doppler parameters in the different annular sites. METHODS: Of 24 FAP patients studied, 14 were included. In each patient we performed conventional transmitral pulsed wave Doppler and tissue Doppler in the 4 sites of the mitral annulus and measured the velocities of the rapid filling wave e, of the atrial contraction wave a and calculated e/a ratio. RESULTS: According to the transmitral inflow profile, patients were divided in 2 groups: Group I--normal global diastolic function and Group II--abnormal relaxation. Group I--33% of these patients showed e/a > 1 in the four sites and 67% showed e/a > 1 in at least 1, but not in all the sites. The rate of normal sites per patient was 3.1. Group II--25% of these patients showed e/a < 1 in the 4 sites of the annulus and 75% had e/a < 1 in at least 1, but not in all the sites analysed. The rate of abnormal sites/patient was 3.1. in this group. When conventional and tissue Doppler data were compared (bland and altman) the septal portion of the annulus was the one with the best correlation. CONCLUSIONS: 1--The assessment of the mitral annulus motion with tissue Doppler imaging is dependent on the site selected for study. 2--The septal site was the one that showed the highest correlation and concordance between pulsed wave Doppler and tissue Doppler. 3--The relative number of normal versus abnormal sites was determinant of the transmitral pattern. 4--Tissue Doppler imaging identified: a) among patients until now classified as normal diastolic function, a subgroup of patients with abnormal function in some sites of the annulus and b) among patients with abnormal relaxation, a subgroup with normal diastolic function in some sites of the annulus.

Adult↗
PubMed2000

Tissue Doppler imaging: clinical topics for the new millenium.

INTRODUCTION: Tissue Doppler imaging is an echocardiographic technique that allows the selective visualization and quantification of myocardial signals. Its aim is to complement the conventional Doppler study, adding more and better information on specific topics of cardiovascular diseases. During the first seven years of the technique, much scientific work was produced and some clinical applications of the method have emerged. CLINICAL APPLICATIONS: I--non ischemic heart disease: The technique has been widely used in diastology, in hypertrophic cardiomyopathy, in heart transplant patients and in arrhythmology. II--ischemic heart disease: The quantitative assessment of regional diastolic and systolic function makes the technique very promising during stress echocardiography and during percutaneous transluminal coronary angioplasty. CONCLUSIONS: In 2000, tissue Doppler echocardiography is still a young, exciting and promising technique. Despite the fact that much has already been done, there is still a long way to go, implying a great amount of time and personal investment. How often do we feel that we are building a small part of the future?

Echocardiography, Doppler↗
PubMed2000

[Diastolic dysfunction and left ventricular hypertrophy in familial amyloidotic polyneuropathy: a cause-effect relationship?].

UNLABELLED: TTR Met30 Familial Amyloidotic Polyneuropathy of the Portuguese type (FAP) is an incapacitating and lethal hereditary disorder that affects predominantly young adults of both genders. Portuguese type FAP patients have sensory, motor and autonomic polyneuropathy. The generalised systemic amyloid infiltration involves the heart, leading to the characteristic granular bright sparkling echocardiographic pattern. LV wall thickening occurs in the late phases of the disease. LV diastolic dysfunction has been reported in the absence of systolic dysfunction; an abnormal diastolic transmitral flow pattern assessed by pulsed wave Doppler (PW) was described. PW is very much dependent on load conditions. Tissue Doppler imaging (TDI) has been used as a more reliable method to assess long axis diastolic function. OBJECTIVE: 1--To identify the incremental value of TDI in the assessment of diastolic function in FAP. 2--To correlate diastolic pattern abnormalities and left ventricular mass index (LVMI) in FAP patients. METHODS: We performed a prospective evaluation of 24 consecutive FAP patients and selected 14 (sinus rhythm, age < 45 years). Diastolic function was assessed by PW and classified as normal (GI-E/A > 1) or abnormal (GII-E/A < 1). TDI was performed in 4 sites of the mitral annulus (septum, lateral, inferior, anterior). Velocities of the rapid filling wave (E') and atrial contraction wave (A') were measured and E'/A' calculated. In each site we considered the TDI as normal (E'/A' > 1) or abnormal (E'/A' < 1). The LVMI was calculated by Devereux's formula. RESULTS: Age, gender and heart rate were similar in both groups. TDI at the septal mitral annulus was normal in all of the GI patients (E'/A': 1.29 +/- 0.19) and suggestive of abnormal LV relaxation in all of the GII patients (E'/A': 0.82 +/- 0.11, p < 0.0001). TDI revealed abnormal diastolic pattern when a restricted number of sites of the mitral annulus were assessed, even in GI patients and before PW abnormalities occurred. Fractional shortening (FS) and LVMI were similar in GI and GII (FS-GI: 45.5 +/- 5.3, GII 43.5 +/- 8.1%, p: NS; LVMI--GI: 66 +/- 9.3, GII: 67 +/- 3.0 g/m2 p: NS). CONCLUSION: The assessment of mitral annulus motion has introduced new data in the study of diastolic function of FAP patients. An abnormal LV relaxation pattern occurred early in the evolution of the disease in patients with normal LVMI and systolic function.

Adult↗
PubMed1993

["Severe" congestive heart failure at a medical center].

UNLABELLED: Heart failure (HF) is a dynamic clinical syndrome depending on multiple hemodynamic and neurohormonal factors. This syndrome concerns not only left ventricular systolic dysfunction but also left ventricular diastolic dysfunction and right ventricular dysfunction. Clinical features and therapeutic approaches are different for each of them. NYHA class IV is just one of the various prognostic factors of heart failure; consequently, severe heart failure is not synonymous of NYHA class IV. OBJECTIVE: To study hospitalised patients with heart failure in NYHA class IV, in order to characterise the predominant dysfunction, and analyze evolution and mortality. DESIGN: A retrospective analysis of a prospective study. SETTING: Hundred and eight hospitalised patients (1985-89). Patients with chronic obstructive pulmonary disease and acute myocardial infarction were excluded. PATIENTS: Sixty nine patients: 29 female and 40 male, aged 18 to 81 years old (m = 59 +/- 15.5). METHODS: Patients were clinically examined and had chest radiographs, electrocardiogram and M + 2D mode echocardiogram. Three groups were identified: Group I-patients with predominant left ventricular systolic dysfunction; Group II-patients with predominant left ventricular diastolic dysfunction; Group III-patients with predominant right ventricular dysfunction. RESULTS: 41% of the patients had coronary artery disease; 44%, valvular heart disease; 11.8% dilated cardiomyopathy; 8.7% hypertrophic cardiomyopathy; 8.7% hypertensive cardiomyopathy. Fifty five percent of the patients were in group I and the major aetiology were coronary artery disease and valvular heart disease; 25% of the patients were in group II and the major aetiology were coronary artery disease and hypertrophic cardiomyopathy; 20% of the patients were in group III, all had valvular heart disease. The global mortality during the hospitalisation period was 15.9%, mostly group III (29%) and II (17%). CONCLUSIONS: Heart failure patients in NYHA class IV formed an heterogeneous group, requiring individualised therapeutic approaches. Left ventricular systolic dysfunction was the major pathophysiological mechanism, however, diastolic dysfunction and right ventricular dysfunction were frequent. Coronary artery disease presented as a frequent aetiology of heart failure, resulting in diastolic and/or systolic dysfunction. Valvular heart disease can be present as left ventricular systolic or diastolic dysfunction or as a right ventricular dysfunction, depending on the valvulopathy and the time of evolution. Echocardiography, in association with clinical features, has been very useful for each patient approach, allowing HF aetiology and pathophysiological mechanisms characterisation. The low mortality observed in this study was related certainly to the correction of precipitating factors, together with early etiologic diagnosis and pathophysiological characterisation, and adequate individualised treatment.

Adolescent↗