PubMed Health⌕ Search

Biomedical subjects

A A Monteiro

Publications and source records attributed to A A Monteiro.

17 recordsLinked to original sources
PubMed1994

[Free thrombi in the left atrium. Report of a clinical case].

The authors describe a case of a floating thrombus in the left atrium, detected by a 2D echocardiography in a female patient suffering from dilated cardiomyopathy. At the follow-up, it was found that the mass was no longer detected inside the left atrium. This occurrence was not associated to any major embolic phenomena. A transesophageal echocardiographic study revealed the presence of a thrombus in the left atrial appendage.

Echocardiography, Transesophageal↗
PubMed1989

Comparison of 133Xe clearance and laser Doppler flowmetry in assessment of blood flow changes in human masseter muscle induced by isometric contraction.

Changes induced by 30 s of isometric contraction at 10% and 50% of the maximum voluntary contraction were assessed in 10 healthy subjects; there was a median increase of 1.8 and 0.3 times in 133Xe clearance and 5.3 and 2.7 times in laser Doppler flowmetry. In the first minute after 10% maximum voluntary contraction, 133Xe clearance increased 12.1 times in relation to the initial resting level, and flowmetry values decreased to become 3.5 times higher than the basal flow; corresponding values after 50% maximum voluntary contraction were 24.3 times and 3.7 times. From the second minute after contraction, there was a rapid decrease in 133Xe clearance and a slow decrease in flowmetry values. Five minutes after biting at 10% maximum voluntary contraction, both methods showed a total net increase of about 15 times; after biting at 50% maximum voluntary contraction the corresponding values were 38 and 23 times. Thus laser Doppler flowmetry can be used to assess changes in blood flow in the masseter; it registers a greater increase in flow during isometric contraction than does 133Xe clearance. The significant difference between methods immediately after either chosen level of contraction disappears when the total net post-contraction hyperaemia is assessed over a period of 2 and 5 min, respectively.

Adult↗
PubMed1989

Reproducibility of estimation of blood flow in the human masseter muscle from measurements of 133Xe clearance.

The reproducibility of estimations of the masseter intramuscular blood flow (IMBF) was assessed bilaterally within and between clinical sessions. The 133Xe clearance in nine normal individuals was measured before, during, immediately after, and after endurance of isometric contraction at an attempted level of 50% of maximum voluntary clenching contraction. An overall low reproducibility of the estimations was found. This result was probably caused by uncertainties about the exact site of intramuscular 133Xe deposition, errors in assessment of the plots of clearance, and variabilities in the relative contraction levels sustained and, especially, in the overall muscle effort. In agreement with previous reports concerning other skeletal muscles, the 133Xe clearance method provided inconsistent estimates of absolute values of IMBF also in this clinical setting. Although there was a high intra-individual variation in the relative level of isometric contraction sustained, the endurance test induced distinct changes in IMBF, among which the estimate of post-endurance hyperemia was the most consistent for each individual. Therefore, measurements of 133Xe clearance seem to be useful to detect intra-individual changes in masseter IMBF resulting from isometric work.

Electromyography↗
PubMed1989

[Are we overdiagnosing and overtreating mild arterial hypertension?].

Mild hypertension is the most difficult type of hypertension do diagnose in clinical practice due to the great variability of blood pressure and to the alert reaction. There is evidence that overdiagnosis and overtreatment of mild hypertension are a common finding. We suggest that more baseline readings should be obtained before establishing the diagnosis. Also an individualized approach should be used and in selected cases, the 24-hour blood pressure monitoring can be useful.

Blood Pressure↗
PubMed1989

The sufficiency of blood flow in human masseter muscle during endurance of biting in the intercuspal position and on a force transducer.

Blood flow changes caused by endurance of voluntary isometric muscle contraction and the sufficiency of flow during contraction were assessed by measuring 133Xe clearance. Aiming at 50% maximum voluntary contraction (MVC), 9 healthy persons sustained biting in the intercuspal position (ICP group) at an actual medium EMG activity level of 55% MVC, while receiving a visual feedback of the average-integrated EMG activity. Eleven persons sustained unilateral biting (UBF group) on a force transducer at 40% MVC, receiving feedback of the force output. The significantly lower % MVC for the UBF group was due in part to a decrease in the EMG activity during endurance, while force was constant. Blood flow changes over time were significant; however, the changes differed significantly between groups during endurance: the ICP group had a median reduction in blood flow to 0.4 of the initial resting value, and the UBF group had a 0.2-fold median increase. Following endurance, flow changes integrated over 3 minutes were about 43-fold the initial resting values of both groups. This similarity was probably a result of their equivalent effort. The endurance flow accounted for 1% of the total change for the ICP group and 5% for the UBF group. Overall, the proportion of the total flow that took place during endurance decreased logarithmically with greater level of contraction and masseter effort. Therefore, sufficiency of blood flow to maintain muscle fibre homeostasis is less when the rate of metabolic turnover is greater, thus contributing to an earlier onset of masseter fatigue, pain and exhaustion at high contraction levels.

Adult↗
PubMed1988

Estimation of blood flow by 133Xe clearance in human masseter muscle during rest, endurance of isometric contraction, and recovery.

Sixty-four measurements of 133Xe clearance from the masseters of 9 individuals, who had no facial or oral pain, were used to evaluate changes in intramuscular blood flow (IMBF) caused by endurance of isometric contraction at approx. 50 per cent of maximum voluntary EMG activity. On average, the IMBF during endurance increased by 4.2 times in 6 individuals and decreased 62 per cent of the rest flow in 3 individuals. Overall, the group average of endurance flow was 2.5 times higher than the initial rest flow. The group average of post-endurance hyperaemia was 27 times higher than the initial rest flow and 11 times higher than the endurance flow. IMBF during the final rest was 1.7 times higher than the initial rest flow. The relative IMBF during endurance was negatively correlated to muscle effort, and the post-endurance flow in relation to the endurance flow presented a compensatory positive correlation to the muscle effort. Although the average IMBF tended to increase during endurance, it was insufficient to meet the demand of the much higher relative increase in muscle activity, as indicated by the pronounced post-endurance hyperaemia, especially after long endurance.

Adult↗
PubMed1988

History factors associated with symptoms of temporomandibular disorders.

Differences in prevalence of head or neck trauma, orthodontic treatment and molar oral surgery procedures reported by individuals were compared among patients with temporomandibular disorders (TMD) and with two comparison groups (a sample of asymptomatic individuals, and a sample with mild or early signs). Association to specific TMD symptoms was tested amongst the comparison groups. Trauma was the most significant factor characterizing TMD patients. History of trauma was also more common among those otherwise normal but symptomatic individuals in the non-patient comparison group. Specific TMD symptoms were significantly associated with history of trauma in the comparison group. Significantly more women TMD patients had a history of orthodontic and molar oral surgery treatment than the asymptomatic comparison group. History of orthodontics was also associated with the symptomatic sample of the comparison group in women, but it was not significantly related to any specific TMD symptoms. Symptomatic members of the comparison group could not be differentiated based upon history of molar oral surgery. Certain risk factors may have been delineated, but causal relationship of treatment requires study of co-existing and predisposing behavioural and structural factors.

Adolescent↗
PubMed1981

Free flaps for reconstruction of the lower extremity.

Experience with the use of free flaps for lower extremity reconstruction during the period 1973 to 1980 is reviewed. From 1973 to 1977, 12 groin and 2 deltopectoral flaps were used, with 8 successes and 6 failures. From 1978 to 1980, 19 myocutaneous flaps (15 latissimus dorsi, 3 tensor fascia lata, and 1 osteocutaneous groin flap based on the deep circumflex vessels) were performed, 17 successfully and 2 unsuccessfully. The reasons for the improved results seem to be the longer and bigger vascular pedicle, the use of more end-to-side arterial anastomoses, and the choice of arterial trunks that are more distal and easier to work with. For these reasons, myocutaneous free flaps are the flap of choice for microsurgical soft tissue reconstruction of the lower limb.

Adolescent↗
PubMedDate not supplied

[Lower limb repair. Bipedicled fasciocutaneous flap. A new technical approach].

The authors present an anatomical study of a fasciocutaneous flap of the lower limb and its clinical application. Sixteen patients with loss of cutaneous substance and exposure of the leg bone were operated on. The bipedicled fasciocutaneous flap presented by the authors allows the coverage of large areas of the lower limb in the initial stage of treatment. Preservation of the superficial venous system allows for a better vascularization of the flap and, thus, for the use of larger flaps.

Accidents, Traffic↗
PubMedDate not supplied

[Collapse of the aortic valve in dilated myocardiopathies: echocardiographic study].

In order to clarify the early systolic partial closure (notching) of aortic valve in patients (pts) with dilated cardiomyopathy (DC), authors (AA) evaluated the M-mode echocardiograms corresponding to 41 pts with DC. Pts were separated in two groups, according to the presence of systolic notching: group A (18 pts) presenting systolic notching; group B (23 pts) in which no systolic notching was observed. For each group, the same echocardiographic parameters were evaluated related to aortic root, left atrium, left ventricule (LV), aortic valve and mitral valve. Both groups were compared statistically. Results--Group A presented a reduced motion of aortic root and greater initial maximal aortic cuspids separation. AA therefore conclude that in pts with DC the systolic notching has no eventual relation with mitral regurgitation. In this setting no conclusions about LV function can be inferred, and it is suggested that systolic notching may bear some relation with differences in the distribution of transvalvular aortic flow.

Adult↗