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Biomedical subjects

A Azevedo

Publications and source records attributed to A Azevedo.

At least 19 recordsLinked to original sources
PubMed2006

Stress and burnout among Portuguese anaesthesiologists.

BACKGROUND AND OBJECTIVE: Anaesthesiology is considered a stressful occupation. Our purpose was to assess stress and burnout among Portuguese anaesthesiologists. METHODS: A cross-sectional survey based on an anonymous questionnaire was sent to all Portuguese anaesthesiologists registered by the Portuguese Medical Association. Data on patient characteristics and professional variables, perceived stress (Perceived Stress Scale), the subscale of work satisfaction of the Pressure Management Indicator scale, burnout (Maslach Burnout Inventory) and main stress factors were collected. The proportion of participation was 31.8%. RESULTS: The average value of perceived stress scale was 24.0 (range: 0-56). Among the 263 anaesthesiologists, 57.9% experienced emotional exhaustion, 44.8% lack of personal accomplishment and 90.9% depersonalisation. Lack of personal accomplishment increased with number of children among women but not among men; depersonalisation was more frequent among anaesthesiologists working in community hospitals and anaesthesiologists with leadership functions experienced less professional stress. CONCLUSION: There are stress conditions and burnout amongst Portuguese anaesthesiologists. The prevalence of depersonalisation was extremely high in the studied sample. Emotional exhaustion is partially explained by high perceived-stress and low satisfaction with organisation in the job according to Pressure Management Indicator scale.

Adult↗
PubMed2005

Spin-wave theory for the dynamics induced by direct currents in magnetic multilayers.

A spin-wave theory is presented for the magnetization dynamics in a ferromagnetic film that is traversed by spin-polarized carriers at high direct-current densities. It is shown that nonlinear effects due to four-magnon interactions arising from dipolar and surface anisotropy energies limit the growth of the driven spin wave and produce shifts in the microwave frequency oscillations. The theory explains quantitatively recent experimental results in nanometric point contacts onto magnetic multilayers showing downward frequency shifts (redshifts) with increasing current, if the external field is on the film plane, and upward shifts (blueshifts), if the field is perpendicular to the film.

Journal Article↗
PubMed2005

Viremia and nasal and rectal shedding of rotavirus in gnotobiotic pigs inoculated with Wa human rotavirus.

Respiratory symptoms with rotavirus shedding in nasopharyngeal secretions have been reported in children with and without gastrointestinal symptoms (Zheng et al., 1991, J. Med. Virol. 34:29-37). To investigate if attenuated and virulent human rotavirus (HRV) strains cause upper respiratory tract infections or viremia in gnotobiotic pigs, we inoculated them with attenuated or virulent HRV intranasally, intravenously, or orally or via feeding tube (gavage) and assayed virus shedding. After oral or intranasal inoculation with attenuated HRV, the pigs remained asymptomatic, but 79 to 95% shed virus nasally and 5 to 17% shed virus rectally. After inoculation by gavage, no pigs shed virus nasally or rectally, but all pigs seroconverted with antibodies to HRV. No viremia was detected through postinoculation day 10. Controls inoculated intranasally with nonreplicating rotavirus-like particles or mock inoculated did not shed virus. In contrast, 100% of pigs inoculated with virulent HRV (oral, intranasal, or gavage) developed diarrhea, shed virus nasally and rectally, and had viremia. The infectivity of sera from the viremic virulent HRV-inoculated pigs was confirmed by inoculating gnotobiotic pigs orally with pooled HRV-positive serum. Serum-inoculated pigs developed diarrhea and fecal and nasal virus shedding and seroconverted with serum and intestinal HRV antibodies. Pigs inoculated intravenously with serum or intestinal contents from the viremic virulent HRV-inoculated pigs developed diarrhea, virus shedding, and viremia, similar to the orally inoculated pigs. This study provides new evidence that virulent HRV causes transient viremia and upper respiratory tract infection in addition to gastrointestinal infection in gnotobiotic pigs, confirming previous reports of rotavirus antigenemia (Blutt et al., Lancet 362:1445-1449, 2003). Our data also suggest that intestinal infection might be initiated from the basolateral side of the epithelial cells via viremia. Additionally, virus shedding patterns indicate a different pathogenesis for attenuated versus virulent HRV.

Animals↗
PubMed2002

Cerebral venous sinus thrombosis in a neonate due to factor V Leiden deficiency.

UNLABELLED: A case is described of cerebral venous sinus thrombosis due to factor V Leiden deficiency that occurred in the neonatal period, presenting with seizures. Diagnosis was based on ultrasonography, Doppler ultrasound (US) and magnetic resonance imaging (MRI). The aetiology was only recognized after blood-clotting tests, antithrombin III, C and S protein levels and factor V Leiden were studied. This situation was treated with intravenous heparin controlled by activated partial thromboplastin time (APTT). MRI angiography and Doppler US were important in the follow-up. It is important to assess periodically the neurological development of the baby and to prevent situations such as dehydration or severe infection, which can precipitate further thrombotic events. Molecular genetics allowed the identification of this trait in other family members. CONCLUSION: In every newborn with a thrombotic episode, coagulation studies must be performed, including testing for activated protein C (APC) resistance. Doppler US flow measurement and the MRI studies provide the best tools for diagnosis and follow-up. Heparin should be given to double the initial individual APTT. It is important to prevent any risk situation such as dehydration or severe infection, which could lead to a recurrence of a thrombotic episode. Regular assessment of the child's neurodevelopment is an important aspect of further care.

Activated Protein C Resistance↗
PubMed2002

Morphology and histoenzymology of eosinophilic granulocytes in the circulating blood of the turtle (Chrysemys dorbignih).

The studies on the characterization of eosinophils and neutrophils/heterophils of turtles are contradictory. Some authors have pointed out the existence of two distinct cell types: eosinophils and heterophils. Other authors have proposed that eosinophils and heterophils may be the same cells in different stages of maturation. These interpretations are based only on a morphological analysis. In the blood of the turtle (Chrysemys dorbignih), a South American freshwater species, there are two types of granulocytes with eosinophilic staining pattern: the first with round cytoplasmic granules and the second with ellipsoidal cytoplasmic granules. In the present study by using histoenzymological methods for the analyses of enzymological cellular content, we found that the cells with round cytoplasmic granules were positive for nonspecific esterase and the cells with ellipsoidal granules were positives for acid phosphatase, alkaline phosphatase, nonspecific esterase and peroxidase. The results show that these cells are distinct cells and that the cells with ellipsoidal cytoplasmic granules have the same histoenzymological characteristics as the neutrophils/heterophils of mammalians and other vertebrates.

Acid Phosphatase↗
PubMed2002

The thrombocyte aggregation process in the turtle Phrynopys hilarii (Chelonia). An ultrastructural study.

This study investigates the thrombocyte aggregation process in the South American fresh water turtle (Phrynopys hilarii) using electron microscopy. Blood was taken from surgically exposed lateral neck vessels of ten turtles Phrynopys hilarii during the spring and summer seasons, when the mean temperature is 37 degrees C. Blood samples were fixed with Karnovsky solution for processing by transmission electron microscopy. The turtle thrombocytes were spindle-shaped with lobulated nuclei. Prominent vesicles and canaliculi were found throughout the cytoplasm. The cytoplasm organelles showed an agranular endoplasmatic reticulum, Golgi complex near the centrioles and scattered free ribosomes. These cells are similar to bird thrombocytes but distinct from fish and frog thrombocytes. Blood clotting time was 5 min +/- 30 sec measured by the Lee and White method. Structural alterations resulting from the aggregation process occurred after activation. Thrombocytes developed numerous filopodial projections, an increased number of vacuoles and changed from spindle to spherical shape. P. hilarii thrombocytes have different morphologic characteristics compared to other non-mammalian vertebrate cells. These cells can participate in the aggregation process, as observed in birds.

Animals↗
PubMed2002

Localization of peroxidase activity in blood mononuclear phagocytes in pacu fish (Piaractus mesopotamicus).

The localization of peroxidase activity in different cell regions is used as a criterion for classifying the stage of maturity of mammalian mononuclear phagocytes, with a positive peroxidase reaction indicating the presence of monoblasts, promonocytes, monocytes, and macrophages. Peroxidase activity was observed ultrastructurally in the circulating blood of pacu fish (Piaractus mesopotamicus), identifying monoblasts, promonocytes, monocytes, and macrophages. These observations suggest that differentiation of mononuclear phagocytes occurs in the blood circulation of fish, whereas in mammals, monoblasts and promonocytes are detected in bone marrow, with only monocytes detected in circulating blood and differentiation into macrophages occurring in other body compartments.

Animals↗
PubMed2001

Transradial approach for coronary interventions.

OBJECTIVE: To assess the feasibility and safety of coronary interventions performed through the radial artery. METHODS: We studied 103 patients with ages from 38 to 86 years (57+/-8.7), 90 (87%) males, and: radial pulse with a good amplitude, presence of ulnar pulse, a good collateral flow through the palmar arch assessed with the Allen's test. RESULTS: The vascular approach was obtained in 97 (94%) patients, 88 (91%) treated electively and 9 (9%) during acute myocardial infarction, for primary angioplasty; 56 (64%) unstable angina; 22 (25%) stable angina; 10 (11%) were asymptomatic, 6 referred for recanalization of chronic occlusion and 4 silent ischemia in the first week after acute myocardial infarction. We approached 107 arteries: anterior descending artery, 49 (46%); right coronary artery, 27 (25%); circumflex artery, 25 (23%); diagonal artery, 6 (6%); and 2 saphenous vein bypass grafts. We treated 129 lesions: 80 (62%) B2 type; 23 (18%) B1 type; 17 (13%) C type; and 9 (7%). A type. There were 70 stents, and 59 balloon angioplasties performed. Thirty-two (33%) patients used GP IIb/IIIa inhibitors. The mean duration of the elective procedure was 42.3+/-12.8 min. Success, correct stent deployment and residual lesion <20%, was reached in 100% of the lesions treated with stent implantation; arterial dilation with residual lesion <50% was obtained in 96% of the lesions treated with transluminal coronary angioplasty (TCA). Complications, were: 1 (1.0%) non-Q-wave acute myocardial infarction; 2 (2%) hematomas in the forearm; and 2 losses of radial pulse. CONCLUSION: Radial artery approach is practical and safe for percutaneous coronary interventions there was a low incidence of complications.

Adult↗
PubMed2001

[Relationship between respiratory syncytial virus subtype and clinical severity in bronchiolitis].

BACKGROUND: Respiratory syncytial virus (RSV) is the most frequently implicated agent in bronchiolitis. The virus presents two antigenic subtypes (A and B). The results of studies on the relationship between viral subtype and clinical severity are conflicting. PURPOSE: To evaluate whether the subtype of this virus constitutes an independent variable in the severity of clinical expression of RSV infection. PATIENTS AND METHODS: We prospectively studied previously healthy children aged less than 2 years admitted for RSV infection during an epidemic season. Clinical presentation and evolution, laboratory and radiological aspects were compared in subsets of children infected with RSV subtype A or B. Clinical severity parameters included score and duration of respiratory distress, oxygen requirements, admission to the intensive care unit, mechanical ventilation and length of hospital stay. RESULTS: Eighty-five patients were enrolled in the study (50 boys and 35 girls; mean age 4.8,4.3 months). Fifty-nine children were infected with RSV subtype A. No differences were found in age, sex or antecedents but children with subtype B were less likely to have been breast-fed. Clinical presentation and laboratory and radiological findings were similar in both groups. No statistically significant differences in clinical severity parameters were found between subsets A and B. Age less than 3 months was associated with greater duration of respiratory distress and longer hospital stay. CONCLUSION: The results do not support the hypothesis that subtype A infection is associated with more severe respiratory syncytial virus disease.

Bronchiolitis↗
PubMed2000

Magnon excitation by spin injection in thin Fe/Cr/Fe films

The technique of Brillouin light scattering is used to observe strong excitation of magnons in antiferromagnetically coupled trilayers of Fe/Cr/Fe at room temperature. The magnons are driven out of equilibrium by a microwave current applied in the trilayer through point contacts. The magnitude of the scattering intensity is investigated as a function of the magnon wave number and applied magnetic field. Confirming recent theoretical predictions, the observations provide strong evidence of electronic spin injection in the rf driving field.

Journal Article↗
PubMed1999

Upper-body adiposity and risk of myocardial infarction.

BACKGROUND: The relation between obesity and coronary heart disease (CHD) has long been studied, but no convincing conclusion has been drawn. OBJECTIVE: To estimate the relative risk associated with upper-body adiposity which is at present believed to be a better predictor of CHD. DESIGN: This was a community-based case-control study. METHODS: We studied 338 consecutively admitted patients who had had their first acute myocardial infarction (AMI) and 662 community controls who had not suffered AMI selected as a random sample of adults living in the catchment area of the hospital. We defined three classes of body mass index (BMI) and waist: hip circumference ratio on the basis of tertiles of distribution for controls. Odds ratios (OR) were estimated using unconditional logistic regression. Separate models were built for men and women. RESULTS: In univariate analysis we found a higher risk of AMI for men and women with hypertension, dyslipidaemia, diabetes and lower levels of education, for older women, for male smokers and for men with family histories of CHD. Both for men and for women a higher BMI was associated with a slightly higher risk, whereas the adjusted risk of AMI increased with increasing waist: hip circumference ratio [for men OR (second tertile)= 2.5, 95% confidence interval (CI) 1.3-4.9 and OR (third tertile)= 11.1, 95% CI 6.0-20.6; for women OR (second tertile) = 3.0, 95% CI 0.6-14.8 and OR (third tertile) = 14.1,95% CI 3.2-62.7]. This relation held for each BMI class and was stronger for classes of lower BMI. CONCLUSIONS: Distribution of body fat rather than BMI is a strong marker of risk for AMI and there is a clear interaction between these two variables.

Adult↗
PubMed1999

Tobacco smoking among Portuguese high-school students.

The aim of this study was to evaluate the prevalence, behavioural patterns, and determinants of smoking among a large sample of high-school students from Porto, the second largest city in Portugal, information on sociodemographic characteristics and personal history of tobacco, alcohol, coffee, and illicit drug use was obtained from 2974 students, aged 12-19 years (48.7% female, 51.3% male), using an anonymous self-administered questionnaire. Crude and adjusted odds ratios (OR) were calculated by logistic regression analysis to estimate the association between smoking and the characteristics evaluated. Overall, 35.8% students had never smoked, 39.4% had tried it ("experimental" smokers) but were not smokers, 3.3% were former smokers, 6.6% occasional smokers, and 14.9% regular smokers. The mean age for starting smoking was 13.4 +/- 2.1 years for males and 13.4 +/- 1.6 years for females. The prevalence of current smoking was higher among males than females, but the difference was not significant. Male students were significantly more likely to smoke more cigarettes per day than were females. The prevalence of smoking was significantly associated with the following variables: being aged > 12 years; having parents who had attended school for < 4 years; having a mother (OR = 1.88), siblings (OR = 1.96) or friends (OR = 1.75) who smoked; low academic performance (OR = 1.74 for one or two failures and OR = 2.27 for more than two failures at school); and consumption of coffee (OR = 2.90), alcohol (OR = 3.53), or illicit drugs (OR = 6.69). The prevalence of smoking among adolescents increased with age. There is therefore a need for school-based tobacco prevention programmes which also deal with family influences on smoking.

Adolescent↗
PubMed1998

A case of neonatal haemochromatosis.

We describe a case of neonatal haemochromatosis, pointing out the difficulties in diagnosing this fatal disease, which here involved the early occurrence of hepatic carcinoma.

Autopsy↗
PubMed1995

[Congenital rubella. Still with us].

After vaccination against rubella was introduced, the number of cases of rubella and congenital rubella syndrome decreased significantly. The presentation of a case report of rubella virus congenital infection with important sequellae, stresses the need to reinforce prevention. The existence of rare cases of reinfection imply good surveillance that gestations should be maintained even in women previously immune.

Aortic Coarctation↗
PubMed1995

[The role of low-molecular-weight heparin in unstable angina, acute myocardial infarction and post-elective percutaneous transluminal coronary angioplasty].

PURPOSE: To evaluate the clinical efficacy and safety of subcutaneous (SC) low molecular weight heparin (LMWH) compared to intravenous (IV) non fractioned heparin (NFH) in unstable angina, acute myocardial infarction and post-percutaneous transluminal coronary angioplasty. METHODS: From September/92 to April/94, 314 patients were randomized in two groups. Group I-- 154 patients treated with SC LMWH, using in the 1st phase SC LMWH with a dosage of 160 UaXa IC/kg/day (group IA--92 patients), and in the 2nd, a dosage of 320 UaXa IC/kg/day (group IB--62 patients). Group II--160 patients treated with IV NFH 100UI/kg (bolus), followed by 1000UI/h with adjusted dosage by activated partial thromboplastin time. RESULTS: There was not a statistically significant difference among the three groups in relation to cardiac events, hemorrhagic complications and deaths. CONCLUSION: The clinical efficacy and safety of SC LMWH in patients with unstable angina, acute myocardial infarction and post-percutaneous transluminal coronary angioplasty were similar to IV NFH with the dosages used in this study.

Angina, Unstable↗