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Biomedical subjects

J A da Silva

Publications and source records attributed to J A da Silva.

At least 19 recordsLinked to original sources
PubMed2001

Essential oils from Azorean Laurus azorica.

The essential oils isolated from leaves of ten and from unripe berries of eight populations of Laurus azorica (Seub.) Franco, collected on five islands of the Azorean archipelago, were analysed by GC and GC-MS. All oil samples were dominated by their monoterpene fraction (60-94%), alpha-pinene (15-37%) and 1,8-cineole (12-31%) being the main components of the leaf oils, while trans-beta-ocimene (27-45%) and alpha-pinene (12-22%) were the main components of the oils from the berries. The sesquiterpene fractions of the oils ranged from 3 to 17% and the main components were beta-caryophyllene (traces-8%) and beta-elemene (traces-3%) both in the leaf and berry oils. Some phenylpropanoid components were also present, in total amounting to 17%, trans-cinnamyl acetate (215% of the leaf oils) being the main component of this fraction. Cluster analysis of the enantiomeric composition of alpha- and beta-pinene in the oils from the leaves clearly showed two groups, one constituted by the two populations growing on the island S. Jorge, and the other constituted by the remaining populations.

Chromatography, Gas↗
PubMed2001

Vanadium haloperoxidases from brown algae of the Laminariaceae family.

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.

Chromatography, Ion Exchange↗
PubMed2001

Influence of sex, age, and menopausal state on the course of early rheumatoid arthritis.

OBJECTIVE: To investigate the influences of the menopausal state, sex, and age on the course and outcome of rheumatoid arthritis (RA). METHODS: A cohort of patients with early RA (209 female, 123 male) was studied. Sex, age, and menopausal state at baseline, and disease activity, radiographic joint destruction, and physical disability during 6 years of followup were assessed. RESULTS: The Disease Activity Score (DAS) was significantly higher in female compared to male patients at any time point except at the time of inclusion. This was mainly due to postmenopausal patients. Radiographic joint destruction (RJD) was significantly worse in female patients compared to males at the time of inclusion. Postmenopausal patients had significantly higher RJD than premenopausal patients at the time of inclusion and 3 years thereafter. Older male patients showed worse RJD than younger male patients at all time points measured. Physical disability was significantly worse in female compared to male patients, as well as in postmenopausal compared to premenopausal patients, and older male compared to younger male patients. Stepwise regression analysis revealed that at 3 years higher age and female sex were the best predictors for a worse DAS. Higher age and the interaction term between menopausal state and age best predicted higher RJD. Higher age and the interaction term between menopausal state and age best predicted Health Assessment Questionnaire (HAQ) score. CONCLUSION: Higher age at presentation of RA leads to a more severe disease course in terms of DAS, RJD, and HAQ. Although female sex has a deteriorating effect on the DAS, the menopausal state is responsible for the major part of the differences in outcome between men and women. Postmenopausal state in early RA influences future disability and damage, especially in older patients.

Adolescent↗
PubMed2000

[Estimation of the number of minimum salaries attributed to professions in function of their prestige].

The purpose of this study was to verify the relationship between professional prestige scaled through estimations and the professional prestige scaled through estimation of the number of minimum salaries attributed to professions in function of their prestige in society. Results showed: 1--the relationship between the estimation of magnitudes and the estimation of the number of minimum salaries attributed to the professions in function of their prestige is characterized by a function of potence with an exponent lower than 1,0,2--the orders of degrees of prestige of the professions resultant from different experiments involving different samples of subjects are highly concordant (W = 0.85; p < 0.001), considering the modality used as a number (estimation of magnitudes of minimum salaries).

Attitude to Health↗
PubMed2000

[Comparison of two psychophysical methods for the estimation of the severity of illness].

In this study, 15 diagnoses were selected and evaluated by the methods of estimation of magnitudes and estimation of categories. These methods were performed by 46 subjects (10 physicians, 20 nurses and 16 psychologists). The results show that the non-metric continuum of seriousness of an illness exhibits prosthetic characteristics and the variability of estimates is a linear function of the magnitude estimation, thus confirming that Ekman's law is also valid for non-metric continua.

Brazil↗
PubMed1999

Statistical aspects of genetic mapping in autopolyploids.

Many plant species of agriculture importance are polyploid, having more than two copies of each chromosome per cell. In this paper, we describe statistical methods for genetic map construction in autopolyploid species with particular reference to the use of molecular markers. The first step is to determine the dosage of each DNA fragment (electrophoretic band) from its segregation ratio. Fragments present in a single dose can be used to construct framework maps for individual chromosomes. Fragments present in multiple doses can often be used to link the single chromosome maps into homologous groups and provide additional ordering information. Marker phenotype probabilities were calculated for pairs of markers arranged in different configurations among the homologous chromosomes. These probabilities were used to compute a maximum likelihood estimator of the recombination fraction between pairs of markers. A likelihood ratio test for linkage of multidose markers was derived. The information provided by each configuration and power and sample size considerations are also discussed. A set of 294 RFLP markers scored on 90 plants of the species Saccharum spontaneum L. was used to illustrate the construction of an autopolyploid map. Previous studies conducted on the same data revealed that this species of sugar cane is an autooctaploid with 64 chromosomes arranged into eight homologous groups. The methodology described permitted consolidation of 54 linkage groups into ten homologous groups.

Chromosomes↗
PubMed1999

A complex case of hepatitis in a patient with systemic lupus erythematosus.

Liver involvement in patients with systemic lupus erythematosus (SLE) is considered rare. Previous treatment with potentially hepatotoxic drugs or viral hepatitis have usually been implicated as the main causes of liver disease in SLE patients. On the other hand, even after careful exclusion of these aetiologies, the problem remains whether to classify the patient as having a primary liver disease with associated autoimmune clinical and laboratory features resembling SLE, such as autoimmune hepatitis, or as having liver disease as a manifestation of SLE. We report the case of an elderly woman who presented with acute hepatitis, who had been diagnosed with SLE 14 years ago and who also had Sjögren's syndrome and anti-phospholipid's syndrome for several years. The histology depicted chronic active hepatitis and, after drug-induced hepatitis and viral hepatitis were excluded, the serological and clinical features were shown to be typical of liver damage caused by SLE. The patient was treated with azathioprine 100 mg/d and prednisone 30 mg/d. The clinical symptoms resolved in 10 days and the laboratory values were normal at the end of the first month of therapy. Prednisone was progressively reduced, during a period of 4 months, to 10 mg/d but azathioprine was kept to the same dose. One year after the diagnoses the patient is still in remission. Although uncommon, hepatic involvement is well recognised in SLE. The interest of this case lies in the differential diagnosis and recognition of this condition, which deserves an aggressive treatment.

Acute Disease↗
PubMed1999

[Ratio scaling evaluation of nurses' professional prestige through a cross-modality method].

Professional prestige was determined using the psychophysical methods of magnitude estimation and cross-modality matching with line lengths and dynamometric forces as responses. The main results revealed that: (a) the rankings order resulting from all methods employed provide degrees of prestige which are in close agreement with the different professions (w = 0.94), (b) the non-metric continuum of professional prestige exhibits prothetic characteristics, (c) the variability of estimations is a linear function of the estimation of magnitudes, thus confirming that Ekman's law is also valid for non-metric continua, (d) the exponents obtained using matchings of number, line lengths and force of hangrip were not significantly different from the exponents predicted by the transitivity property of scales and, finally (e) the data furnish a scale of professional prestige which, at the level of ratio measurement, is valid, stable and consistent.

Adolescent↗
PubMed1999

[Evaluation of the severity of clinical illness: a psychophysical approach].

The severity of clinical illness was evaluated through the psychophysics method of magnitude estimation. The purpose of this experiment was: 1) to compare the scales derived from right judgement (magnitude estimation) used in three different Brazilian samples; 2) to verify the stability and agreement of severity estimations of clinical situations judged in Brazil, USA and England. In order to develop this study, professionals who work in the areas of psychology, nursing and medicine were invited. The lower coefficient of Pearson's correlation among the groups were of 0.88 the and the greater of 0.94. The exponents found between the Brazilian and American samples were of 1.22 and between the Brazilian and English samples of 1.15.

Adult↗
PubMed1998

[Intracranial arachnoid cyst. Report of 9 operated cases].

Analysis of nine patients with intracranial arachnoid cysts surgically treated from 1974 to 1995. The treatment consisted of cystoperitoneal shunt in seven patients and craniotomy with excision of cyst membrane in the other two cases. After surgery, bacterial meningitis and failure shunt device were observed in three cases. Both the infectious process and the shunt device were respectively treated and corrected at once. It has been observed total clinical improvement in all nine cases. A review of the literature has been made and some pathophysiological, diagnostic and therapeutic aspects are discussed.

Adolescent↗
PubMed1998

[Profile of the resistance to macrolides and imidazoles of Helicobacter pylori in a sample of the Portuguese population].

We studied the sensitivity of H. pylori to clarithromycin and metronidazole, as well as the sensitivity and specificity of H. pylori culture, urease test and histology on a sample of 166 Portuguese patients. We observed a prevalence of 5.8% resistance to clarithromycin and 60% resistance to metronidazole. The sensitivity and specificity for the diagnostic tests were: culture 98% and 100%, urease test 98% and 91%, histology 50% and 95%, respectively.

Anti-Bacterial Agents↗
PubMed1998

Cholestasis secondary to Hodgkin's disease: report of 2 cases of vanishing bile duct syndrome.

Only a small percentage of patients with Hodgkin's disease become clinically Jaundiced during their disease. This Jaundice may be secondary to biliary obstruction, hemolysis, direct hepatic infiltration by the disease, drug toxicity or viral hepatitis. Vanishing bile duct syndrome secondary to Hodgkin's disease is a rare cause of cholestasis in these patients, only 13 cases having been reported so far. The authors describe 2 patients who developed severe Jaundice secondary to Hodgkin's disease due to vanishing bile duct syndrome affecting small intrahepatic bile ducts.

Adult↗
PubMed1997

[Progressive facial hemiatrophy (Parry-Romberg disease). Report of two cases associated with trigeminal neuralgia and cramps].

The authors report two cases of progressive facial hemiatrophy (PFH) associated with cranial nerves hyperexcitability. One of them (Case 1), a 41-year-old-woman noticed a slight atrophy on the left side of her face at age of ten. For the last three months, she has been suffering from fits of neuralgic pains on the left side of her face which have not ceased by drug treatment In view of this, a surgery procedure was planned for the patient. The other patient (Case 2), a 33-year-old-woman has a 8 year history which started with cutaneous abnormalities (white and dark spots). Two years later she observed that her right cheek and right thigh had got a mild atrophy. Frequently, she has been complaining of cramps in the mandibular region which are precipitated, sometimes, by opening the mouth. A probable relation between neural excitability and PHF is discussed.

Adult↗
PubMed1997

[Sex hormones and osteoporosis: a physiological perspective for prevention and therapy].

Estrogen deficiency is the main cause of post-menopausal osteoporosis and hormone replacement therapy is consensually regarded as the first line choice for its prevention. Hormone-replacement has also been shown to prevent bone loss associated with rheumatoid arthritis (RA) and corticotherapy. The rationale for its use in RA is reinforced by evidence of beneficial effects on disease activity. Estrogens also have bone-protective effects in males. C-19 progestagens seem to potentiate the skeletal effects of estrogens whereas C-21 derivatives appear to have no significant influence. Progestagens may be particularly useful in the prevention of steroid-induced osteopenia. Testosterone is an effective treatment for male osteoporosis associated with hypogonadism and is also promising in the treatment of osteoporosis in aged eugonadal males. The association of this hormone potentiates the effects of estrogens on bone mineral density in post-menopausal women. However, anabolic androgens have been preferred in this condition, due to a lower androgenizing effect. They represent a valid therapeutic alternative, particularly in cases of cortical osteoporosis with low bone turnover and in the aged and frail. In general, the different modalities of hormonal therapy clearly deserve a higher degree of preference in the treatment and prevention of osteoporosis than common present practice in our country. It is time to reassess this matter, clear unfounded fears and reinforce the physiological and scientific foundations of our therapeutic options for osteoporosis.

Androgens↗
PubMed1996

[Use and application of psychophysical methods in nursing research].

Concepts and subjective phenomena such as social attitudes, opinions, and judgment processes have always been difficult to measure accurately. Many concepts or variables in nursing are of a subjective nature. As with the social sciences, the nursing profession has faced many problems in attempting to obtain precise measurements of such variables. The psychophysical methodology, specially the magnitude estimation and cross-modality matching procedures, developed in sensory psychophysics and currently being used in the social sciences, shows promise for providing nursing with an instrument of precisely scaling subjective phenomena. The purpose of this paper is to describe these measurement techniques, the theoretical paradigm on which it is based, and several social, clinical and nursing studies that have utilized these sensitive measurement strategies.

Humans↗
PubMed1995

Kinetics and thermal behaviour of the structure formation process in HMP/sucrose gelation.

The concentration and temperature dependence of the gelation kinetics of high-methoxyl pectin (HMP; 60% sucrose, pH 3) was investigated using measurements of small-amplitude oscillatory shear. The rate of gelation close to the gel point can be described as a second-order rate process using the kinetic model of Ross-Murphy (Carbohydr. Polym. 1991, 14, 281) and a critical exponent close to that predicted by the percolation approach. The modulus after a long ageing time showed a power concentration dependence with an exponent around 3.1, higher than the classical square of concentration dependence, which was probably either due to the nonequilibrium state of the HMP gels even after long ageing times, or due to the proximity of the concentration range studied to the critical gelling concentration. The gelation rate of HMP/sucrose systems is strongly dependent on the temperature. An Arrhenius relationship was applied to describe this dependence. Two different processes are proposed to explain the discontinuity observed, each one having rates with different temperature dependence. The applicable kinetics at longer times are quite different, with a lower dependence on polymer concentration and ageing temperature. A non-isothermal kinetic model was used to describe the gelation process of the HMP/sucrose system during cooling.

Food Technology↗
PubMed1995

[Acute neurogenic pulmonary edema: a case report].

The authors report a case of acute neurogenic pulmonary edema in a 28-year-old woman who presented rupture of an internal carotid artery aneurysm and subarachnoid hemorrhage. The respiratory disorders started at the same time the patient's symptomatology aggravated. Some etiological and pathophysiological aspects on neurogenic pulmonary edema are revised.

Acute Disease↗