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Biomedical subjects

M Coutinho

Publications and source records attributed to M Coutinho.

At least 19 recordsLinked to original sources
PubMed2002

Air quality management in Portugal: example of needs and available tools.

The Framework Directive (FWD) and the proposed Daughter Directives are the newest legislative instruments concerning a new political strategy and air quality management approach for Europe. Additionally, the member countries of the United Nations Economic Commission for Europe have included the concepts of critical load and level for planning air pollution abatement strategies and as a base of international agreements concerning limitation of the emissions of air pollutants. These concepts imply an accurate knowledge about pollutants deposition fluxes. The paper describes the main needs and the tools available to define a strategy of air quality management in Portugal. Two study cases are presented: (1) extensive monitoring plan to assess the impact of an urban incinerator plant; and (2) contribution to a methodology to estimate critical levels for a coastal region in Portugal. These different approaches allowed illustrating the complexity of the implementation of an air pollution management strategy.

Air Pollution↗
PubMed2001

The aesthetic implication of scar position in breast reconstruction.

In these enlightened times of patient involvement in operative planning, the patient has a much greater input into procedure selection, especially where several options are available. Breast reconstruction is a prime example of combined decision making, although options are still limited by pre-existing scars and previous treatment. In this study we eliminated all variables of reconstruction except the resulting scar pattern in an attempt to discover what was most acceptable to the patient. Various postoperative results, such as single scars and flaps, were mimicked unilaterally and bilaterally by drawing them on the same live subject. These photographic images were then formulated into a questionnaire and distributed to various female groups for scoring. Results show a preference for single-line horizontal scars in unilateral and bilateral reconstructions; scars that encroached the upper medial quadrant scored less well. The preferred flap reconstruction is also positioned horizontally, but in the lower pole. Overall, the preferred reconstruction in all groups was a single unilateral horizontal scar.

Adolescent↗
PubMed1999

Ninety years of Chagas disease: a success story at the periphery.

Periphral countries are at a disadvantage with respect to the construction of scientific knowledge, which is mostly carried out by a small number of traditional core loci countries. However, in a few cases, groups of scientists are able to break through exclusion barriers. Sometimes they tackle relevant issues, share values and procedures with core loci representatives, and take part in heated controversies: in short, they participate in the construction of legitimate science. These scientists form centers of excellence in scientifically marginal countries. In this paper, contextual conditions involving the emergence, establishment and decline of such enterprises are discussed, on the basis of examples drawn from the history of Chagas disease (Cd). In this history, we see a major discovery established, deconstructed and re-established. Quantitative analyses of publication on CD over 70 years show the relation between the choice of different types of journals and methodological approaches, and the legitimation strategies adopted by different groups of practitioners. It also shows the outcomes of such strategies in terms of production concentration, emergence of new authors and growth of institutional work. This story shows that it is important for the pioneers to establish a different intellectual culture in their local environment. Unless they do so, and gain its acceptance among their immediate colleagues, the enterprise cannot preserve its status as a centre of excellence.

Brazil↗
PubMed1999

The noble enigma: Chagas' nominations for the Nobel prize.

Carlos Chagas, a Brazilian physician, discovered the American trypanosomiasis in 1909. Like other remarkable discoveries of those days, his work helped to articulate the insect-vector theory and other theoretical guidelines in tropical medicine. Unlike all other discoveries, all the stages of this work were accomplished in a few months and by a single man. Chagas' discovery was widely recognized at home and abroad. He was twice nominated for the Nobel Prize - in 1913 and in 1921-, but never received the award. Evidence suggests that the reasons for this failure are related to the violent opposition that Chagas faced in Brazil. The contentions towards Chagas were related to a rejection of the meritocratic procedures that gave him prominence, as well as to local petty politics.

Brazil↗
PubMed1999

The relationship between glucose and incident cardiovascular events. A metaregression analysis of published data from 20 studies of 95,783 individuals followed for 12.4 years.

OBJECTIVE: To assess the relationship between nondiabetic glucose levels and cardio vascular risk. RESEARCH DESIGN AND METHODS: Three independent searches using MEDLINE (1966-1996), followed by a manual search of the references from each retrieved article, were conducted by two physicians and one medical librarian. Data had to be reported in at least three quantiles or intervals so that the nature of the relationship between glucose and cardiovascular events (i.e., linear or nonlinear) could be explored, and to ensure that any incremental cardiovascular risk was consistent across quantiles or intervals. RESULTS: Analyzed studies comprised 95,783 people (94% male) who had 3,707 cardiovascular events over 12.4 years (1,193,231 person-years). Studies reporting fasting glucose levels (n = 6), 2-h glucose levels (n = 7), 1-h glucose levels (n = 5), and casual glucose levels (n = 4) were included. The glucose load used varied from 50 to 100 g. The highest glucose interval for most studies included glucose values in the diabetic range. The relationship between glucose levels and the risk of a cardiovascular event was modeled for each study and the beta-coefficients were combined. Compared with a glucose level of 4.2 mmol/l (75 mg/dl), a fasting and 2-h glucose level of 6.1 mmol/dl (110 mg/dl) and 7.8 mmol/l (140 mg/dl) was associated with a relative cardiovascular event risk of 1.33 (95% CI 1.06-1.67) and 1.58 (95% CI 1.19-2.10), respectively. CONCLUSIONS: The progressive relationship between glucose levels and cardiovascular risk extends below the diabetic threshold.

Adult↗
PubMed1996

Treatment for acute myocardial infarction. Overview of randomized clinical trials.

This review summarizes the results of several pharmacological interventions that have been evaluated in the management of acute myocardial infarction. Of these, thrombolytic therapy, aspirin, beta-blockers and angiotensin converting enzyme inhibitors have all been proven to reduce mortality risk and the latter three classes of drugs have also been shown to reduce morbidity. Routine use of heparin or nitrates is not recommended although they may be useful in specific circumstances such as post-infarction angina or large infarcts. Drugs that have as yet not been shown to have a role in the routine management of acute myocardial infarction include Class I antiarrhythmic agents, magnesium and calcium antagonists. Management of patients with acute myocardial infarction can now be appropriately based on the evidence generated from well conducted randomized clinical trials and appropriate therapeutic choices based on such information can be expected to reduce their morbidity and mortality risks.

Evaluation Studies as Topic↗
PubMed1994

Functional analysis of the serpin domain of C1 inhibitor.

To analyze the role of the heavily glycosylated amino-terminal domain of C1 inhibitor in protease inhibitory activity, two truncated C1 inhibitor molecules were constructed. The abilities of the recombinant truncated inhibitors to complex with target proteases were compared with that of the wild-type recombinant protein. One recombinant truncated molecule consisted of amino acid residues 76 to 478 (C-serp(76)) and the other of residues 98 to 478 (C-serp(98)). The recombinant proteins were each expressed in similar quantities. The thermal denaturation profiles of the two truncated proteins were similar to that of the wild-type protein. Identical binding of C1s, C1r, kallikrein, and beta factor XIIa was observed with the three molecules. Furthermore, the truncated molecules also effectively inhibited C1 activity in hemolytic assays. These studies therefore clearly demonstrate that the amino-terminal domain of C1 inhibitor does not influence complex formation with target proteases.

Complement C1 Inactivator Proteins↗
PubMed1994

Corticotropin-releasing hormone (CRH) is a respiratory stimulant in humans: a comparative study of human and ovine CRH.

Previous experimental and clinical studies clearly demonstrated that exogenously administered CRH possesses respiratory properties. Until now, these effects were investigated using human (h) CRH in both healthy volunteers and patients under long-term respiration. We now compared the effects of hCRH with those of ovine (o) CRH in ten healthy young males. In particular it should be evaluated whether oCRH with its longer plasma half-life induces a more profound respiratory stimulation. On two separate days within two weeks, ventilation and cardiac performance were measured during steady state conditions by using a computerized cardio-pulmonary exercise testing system. In this placebo controlled double-blind-crossover study h- and oCRH (100 ug i.v. each) both augmented minute volume significantly during the observation period. Heart rate also increased after both analogues. All effects were comparable without a significant difference between both substances. There were no major side effects observable. Our data thus demonstrate that both analogues might be suitable for both diagnostic (i.e., testing of respiratory and autonomic responses) and therapeutic purposes.

Adrenocorticotropic Hormone↗
PubMed1994

[The VO2 performance index for evaluation of cardiopulmonary capacity in respiratory minute volume controlled VVI-R stimulation].

This study was designed to assess the effect of acute minute ventilation sensing, rate-responsive pacing on cardiopulmonary exercise capacity in 27 patients (mean age 60 years) with chronotropic incompetence. The exercise protocol consisted of bicycle exercise in semisupine position with breath-to-breath analysis of gas exchange. At the anaerobic threshold heart rate increased from 75 +/- 9 in the VVI-mode to 113 +/- 21 beats/min in the VVI-R-mode (p < 0.001), oxygen uptake from 9.3 +/- 3.4 to 10.9 +/- 4.3 ml/kg/min (p < 0.001) and work rate from 52 +/- 20 to 65 +/- 24 watts (p < 0.001). Compared to 41 normal subjects, VVI-R pacing increased oxygen uptake up to 75% and work rate up to 79% of normal values, while heart rate increased similarly in both groups. The VO2 to work rate ratio (dVO2/dWR), calculated as the slope of the relation of oxygen uptake to work rate below the anaerobic threshold, improved from 7.9 +/- 2.3 to 10.2 +/- 2.4 ml/min/watts (p < 0.001) in the VVI-R-mode; so it did not differ from normal values. Thus, acute respiratory dependent rate-responsive pacing results in substantial improvement in cardiopulmonary exercise capacity in patients with chronotropic incompetence. The VO2 to work rate ratio demonstrated to be a reliable parameter for assessing this improvement.

Adolescent↗
PubMed1994

[Semi-supine cardiopulmonary stress test in middle-aged probands with healthy hearts].

Normal values for cardiopulmonary bicycle exercise testing in semisupine position using a ramping protocol in a middle-aged group of untrained men and women are presented. We exercised 23 men and 16 women aged from 33 to 66 years without evidence of cardiopulmonary or cardiovascular disease and normal findings during complete heart catheterization. Clinical findings, x-ray, resting and exercise ECG, and laboratory findings were normal. Exercise testing was performed using a ramping protocol with a work rate increase of 20 watts/min. Respiratory gas analysis (breath-to-breath method) was performed and oxygen uptake (VO2), carbon-dioxide production (VCO2), and minute ventilation (VE) were determined at maximal work load and at the ventilatory anaerobic threshold. Work rate increase and heart rate were continuously monitored. From these data oxygen pulse, the respiratory quotient (RQ), and the ventilatory equivalents VE/VO2 and VE/VCO2 were derived. Furthermore, the VO2 to work rate ratio, and the VO2 to heart rate ratio were analyzed. Maximal VO2 was within the 95% confidence interval of predicted VO2max. The anaerobic threshold (V-slope method) was 60% of VO2 max at the RQ of 0.81 for men and 66% of VO2max at the RQ of 0.84 for women. The O2 pulse was 100% of the age predicted value. The VO2 to work rate ratio was 10.7 +/- 1.4 for men and 9.7 +/- 1.2 ml/watts/min for women (p < 0.05). The slope of heart rate to VO2 from rest to peak exercise as a measure of chronotropic competence was nonlinear in 59% of the subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Ventilation and heart rate response during exercise in normals: relevance for rate variable pacing.

The observation of a close relationship of heart rate to oxygen uptake (HR-VO2) and heart rate to minute ventilation (HR-VE) has been shown to be of particular value in rate variable pacing. However, the impact of anaerobic threshold (AT) for the HR-VO2 and HR-VE slope has been studied less. Twenty-three male and 16 female subjects, mean age 52 +/- 7 years, were selected in whom complete heart catherization and extensive noninvasive studies excluded major cardiopulmonary disease. Semisupine bicycle exercise testing with analysis of respiratory gas exchange was performed using a ramping work rate protocol with work increments of 20 watts/min. At the respiratory AT, determined by the V slope method, oxygen uptake (VO2-AT) was 15.2 +/- 3.0 mL/kg in males versus 13.8 +/- 2.3 mL/kg in females and heart rate (HR-AT) was 109 +/- 18 beats/min versus 119 +/- 20 beats/min, respectively. Heart rate was highly correlated (r > or = 0.9) to VO2 and minute ventilation (VE). A linear regression for HR-VO2, however, was found only in 16/39 and for HR-VE in 11/39 subjects. Assuming the AT as the breakpoint of two linear curves, it could be demonstrated that compared to low exercise HR appeared to increase at maximal exercise more in relation to VO2 but less in relation to VE; in men the individual slopes for HR-VO2 were 2.6 +/- 0.7 below but 3.2 +/- 1.0 above AT (P < 0.05) and the slopes for HR-VE were 1.6 +/- 0.5 below but 1.0 +/- 0.4 above AT (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Anaerobic Threshold↗
PubMed1992

C5 deficiency in A/J mice is not associated with resistance to the development of secondary amyloidosis.

The aim of the study was to determine whether C5 deficiency in the mouse is associated with resistance to the development of secondary amyloidosis. Chronic inflammation was induced in the F2 progeny, derived from matings between amyloid-susceptible and amyloid-resistance mice, by daily injections of azocasein for thirty days. Using a restriction fragment length polymorphism generated by digestion of genomic DNA with the restriction enzyme HindIII, C5 sufficient and deficient DNA can be clearly differentiated. Eight mice were found to be C5 sufficient, 32 were heterozygotes and 14 were found to be C5 deficient. Grading of the splenic amyloid load from negative to 4+ was performed after staining tissue squashes with Congo red and viewing them under a polarizing microscope. Seventeen mice were noted to have negative to trace, 18 had moderate (1+ - 2+) and 19 had heavy (3+ - 4+) amyloid deposition. There was no correlation between splenic amyloid load and C5 deficiency. Based on these results it is clear that C5 deficiency and resistance to secondary amyloidosis are not associated.

Amyloid↗
PubMed1992

[Not Available].

Explore the source record for details and available documents.

Biology↗
PubMed1990

[Cardiopulmonary stress: control of the function of frequency variable pacemaker systems].

Based on the linear relationship between cardiac output and oxygen uptake direct breath-to-breath gas exchange measurements during exercise allow accurate determinations of cardiopulmonary function. We used cardiopulmonary exercise testing to assess the physiologic benefit of rate response VVIR pacing in 17 patients with chronotropic incompetence. 13 patients had an activity-rate-response pacemaker, two patients had a temperature-controlled pacemaker and two patients a respiratory-dependent system. Exercise testing was performed with the pacemaker, either programmed to fixed rate VVI or to rate variable VVIR pacing. All patients were exercised on a bicycle using a ramp protocol with 10 to 20 watts/min increments. Maximal oxygen uptake and the anaerobic threshold were determined. Compared with findings in the VVI mode, rate response VVIR pacing increased maximal exercise heart rate from 74 +/- 10 to 118 +/- 21 bpm (p less than 0.001). This increase in heart rate was associated with an increase of maximal oxygen uptake from 14.3 +/- 5 to 18.3 +/- 6 ml/kg per min (p less than 0.04) and a delay of the anaerobic threshold to a higher oxygen consumption of 14.6 +/- 5 vs 10.6 +/- 5 ml/kg per min (p less than 0.04). The individual increase in oxygen uptake was a direct function of the change in exercise heart rate independent of the implanted pacing device. The improved aerobic capacity resulted in a 17% increase in exercise tolerance and a 19% increase of exercise time. Cardiopulmonary exercise testing appears to be a useful noninvasive technique to quantify the cardiopulmonary benefit of rate response pacing.

Adult↗
PubMed1989

Femoral duplication: a case report.

Femoral duplication is a rare anomaly that has been described as an isolated entity and in association with other congenital defects. Since the description by Erlich in 1885, 24 additional cases have been reported. The present report concerns a 34-week black female infant with apparent bilateral femoral duplication associated with a meningocele and abdominal, genitourinary, vertebral, and lower-limb anomalies. The cause is unknown. Femoral duplication is a developmental field defect, hence causally heterogeneous.

Abnormalities, Multiple↗