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Biomedical subjects

D M Braile

Publications and source records attributed to D M Braile.

At least 19 recordsLinked to original sources

Standardization of an isolated pig heart preparation with parabiotic circulation: methodological considerations.

In the present study we standardized an experimental model of parabiotic circulation of isolated pig heart. The isolated heart was perfused with arterial blood from a second animal as support and submitted to regional ischemia for 30 min, followed by total ischemia for 90 min and reperfusion for 90 min. Parameters for measurement of ventricular performance using different indices measured directly or indirectly from intraventricular pressure were defined as: maximum peak pressure, final diastolic pressure, pressure developed, first derivative of maximum pressure (dP/dt max), first derivative of minimum pressure (dP/dt min), systolic stress of the left ventricle (sigmas), and maximum elastance of the left ventricle. Isolated hearts subjected to regional and global ischemia presented significant worsening of all measured parameters. Less discriminative parameters were dP/dt max and dP/dt min. Elastance was the most sensitive parameter during the reperfusion period, demonstrating an early loss of ventricular function during reperfusion. The model proved to be stable and reproducible and permitted the study of several variables in the isolated heart, such as ischemia and reperfusion phenomena, the effects of different drugs, surgical interventions, etc. The model introduces an advantage over the classical models which use crystalloid solutions as perfusate, because parabiotic circulation mimics heart surgery with extracorporeal circulation.

Analysis of Variance↗

Speed of particles ejected from animal skin by CO2 laser pulses, measured by laser Doppler velocimetry.

During ablation of tissue with laser pulses rapid sublimation of matter occurs and high pressures are exerted within the tissue, resulting in steam. smoke and particles being expelled. In this paper we report the speed of particles ejected from animal tissue exposed to CO2 laser pulses measured directly by laser Doppler velocimetry (LDV). Speeds recorded just above animal skin were in the range of 9 to 18 m s(-1) for laser pulses of 128 to 384 J cm(-2) respectively. Aerodynamic turbulence slowed the particles down to a critical speed Vc of 4 m s(-1) within a few millimetres above the laser ablation site. Once the particles reach this minimum speed, if no collisions occur, they will only decelerate by gravitational action and the residual kinetic energy will send the particles up to about 0.87 m from the skin surface. Since ejected particles may carry viable cells, acting as disease vectors during laser surgery, our results suggest that the LDV technique should be used to measure the speed of particles ejected from healthy or pathological human tissues, helping to establish safe conditions during laser surgery.

Animals↗

Quality of life and peripheral lymphedema.

Evaluation of the health-related quality of life (QOL) is becoming commonplace, seeking to provide information about the everyday well-being of a patient. This work examined the QOL of 23 consecutive patients with lymphedema of the upper or lower extremities. Five were men and the other eighteen were women. Their ages ranged from 19 to 74 years (mean 48.3). After clinical examination, and with informed consent of each patient, they were assessed by a psychologist and submitted to a QOL test (SF-36). For controls, twenty-three women and five men with age range of 28 to 66 years (mean 47) were similarly evaluated. The results showed the lymphedema group had a statistically significantly reduced QOL in both physical and mental health as well as social interaction.

Arm↗

Prevalence of antithrombin deficiency in patients with chronic leg ulcer.

Antithrombin is one of the main endogenous anticoagulants and its deficiency is associated with deep venous thrombosis. The aim of the present study was to evaluate the prevalence of antithrombin deficiency in patients with chronic lower extremity ulcers. Forty-eight patients with chronic lower limb ulcers for longer than 10 years, evaluated during 1997, were studied: 40 were female (83.3%) and eight were male (16.6%), with ages ranging from 43 to 73 years (mean, 55.2 years). Antithrombin was dosed by the coagulometric method, with evaluation of the functional activity. Measurement was repeated in those cases where deficiency was found to be present. The highest prevalence rate for antithrombin deficiency in the general population was one in every 2000 cases. Data analysis was performed by utilizing the odds ratio with a confidence interval of 95% and P < 0.05. Deficiency in antithrombin levels was recorded in two (4.1%) of the patients with chronic ulcer. These results indicate a higher prevalence rate of antithrombin deficiency in those patients with chronic leg ulcers, suggesting that an association may be present. Further studies with a larger number of patients are required to confirm this hypothesis.

Adult↗

Superficial thrombophlebitis and anticardiolipin antibodies--report of association.

The aim of this study was to determine a possible association between recidivist superficial thrombophlebitis and anticardiolipin antibodies. Forty-five patients with two or more episodes of superficial thrombophlebitis in lower limbs (33 women and 12 men with ages ranging from 17 to 60 years, average: 39.8) were studied. The control group was formed by 100 voluntary donors from the blood bank (83 men and 17 women, age range: 21 to 59 years, average: 35.4). Anticardiolipin antibody concentrations were determined by enzyme-linked immunosorbent assay (ELISA). For semiquantitative detection in human sera with use of QUANTA Lite ACA IgG/IgM--INOVA Diagnostic, Inc., and positive values were considered as 15 GPL units/mL and 12.5 MPL units/mL for immunoglobulin G (IgG) and IgM, respectively, as recommended by the test. The Odds Ratio method was chosen for statistical analysis with a confidence interval (CI) of 95%. In 15 patients (33.3%) anticardiolipin antibody positivity was detected, whereas in 12 patients (26.7%) it occurred as immunoglobulin M (IgM) anticardiolipin and in 3 (6.7%) as immunoglobulin G anticardiolipin. In the control group, positivity was found in 7 patients (7%) for those antibodies. Furthermore, the Odds Ratio = 6.64 with CI = 95% and values ranging from 2.48 to 17.82 (p < 0.05) were significant, as well as for IgM/IgG anticardiolipin proportion with Odds Ratio = 5.09, C = 95% and values varying from 1.33 to 19.54 (p < 0.05). The authors conclude that there is a correlation between the presence of anticardiolipin antibodies and recurrent superficial thrombophlebitis.

Adult↗

The surgeon.

Explore the source record for details and available documents.

Humans↗

Dynamic cardiomyoplasty: long-term clinical results in patients with dilated cardiomyopathy.

BACKGROUND: Dynamic cardiomyoplasty has been considered to be an effective method of surgical treatment of patients with end-stage heart failure, and is an alternative to heart transplantation. METHODS: We critically evaluated the long-term course of 52 patients with dilated cardiomyopathy who underwent dynamic cardiomyoplasty and were followed-up for up to 110 months. RESULTS: Dilated cardiomyopathy was due to undetermined cause in 42 patients (80.8%), Chagas disease in 8 (15.4%), viral infection in 1 (1.9%), and peripartum cardiomyopathy in 1 (1.9%). In the nonchagasic group the survival rates were 79.5% +/- 6.1%, 67.8% +/- 7.1%, 53.7% +/- 8.3%, 49.9% +/- 8.3%, 14.9% +/- 12.2%, and 14.9% +/- 12.2%, respectively, at 12, 24, 48, 60, 80 and 110 months of follow-up. In the chagasic patients the survival rates were 37.5% +/- 17.1%, 12.5% +/- 11.7%, 12.5% +/- 11.7% and 0%, respectively, at 12, 24, 48, and 60 months of follow-up, making chagasic cardiomyopathy a possible contraindication for dynamic cardiomyoplasty. CONCLUSIONS: There was no correlation between the clinical improvement and hemodynamic data. Ventricular fibrillation was a frequent cause of immediate and late death, suggesting the need for prophylactic use of antiarrhythmic drugs or implantable cardioverter/ defibrillators.

Adolescent↗

Reconstruction of the pulmonary valve and outflow tract with bicuspid prosthesis in tetralogy of Fallot.

BACKGROUND: Right ventricular outflow tract and pulmonary valve implant in patients with tetralogy of Fallot may be required to avoid late postoperative right ventricular impairment. The use of porcine bicuspid prosthesis might be a technical alternative, although comprehensive studies on the long-term use of these prostheses are not available. METHODS: Sixty-three patients (aged 5 months to 34 years; mean, 6 years) with tetralogy of Fallot and pulmonary hypoplasia underwent surgical repair and enlargement of the right ventricular outflow using preserved porcine pulmonary bicuspid prostheses. Fifty-two patients (82.5%) were followed and underwent clinical evaluation and serial Doppler echocardiography. The first 15 patients (29.4%), with ages ranging from 5 to 16 years (mean, 8.2 years) and postoperative follow-up of 48 to 87 months (mean, 65.1 months) underwent hemodynamic and cineangiographic evaluations. RESULTS: There were 11 deaths (17.4%) in the early postoperative period. Of the 52 surviving patients (82.5%), 51 (80.9%) were followed for 1 to 87 months (mean, 42.0 months). Four patients (7.6%) had additional treatment. Of the 15 patients (29.1%) undergoing hemodynamic evaluation, 9 (60%), had mild valvular pulmonary insufficiency and 6 (40%) had moderate insufficiency. Only the right ventricle-to-pulmonary artery pressure gradients and the right ventricular ejection fraction showed statistically significant differences between groups. Right ventricular dimension, although increased in all patients, did not show statistically significant differences. CONCLUSIONS: Right ventricular outflow tract and pulmonary valve repair in patients with tetralogy of Fallot using a bicuspid porcine pulmonary prosthesis is a simple, reliable procedure with good results in postoperative medium term follow-up.

Adolescent↗

Preparation and characterization of collagen-elastin matrices from blood vessels intended as small diameter vascular grafts.

This study describes the selective removal of cell and cell residues from small and large diameter blood vessels for the preparation of tubular collagen:elastin matrices intended for small diameter vascular prosthesis. The results showed that total or partially devitalized collagen:elastin matrices may be conveniently prepared without denaturation of the collagen:elastin matrix with a high degree of preservation of the proteins. The efficiency of cell removal and the extent collagen and elastic fiber preservation were dependent on the segment and the type of blood vessel under study, with arteries characterized by a higher susceptibility of cell removal and better preservation of the collagen-elastin matrix.

Alkalies↗

Prevalence of anticardiolipin antibodies in peripheral arterial thrombosis.

The aim of this study was to assess prospectively the prevalence of anticardiolipin antibodies in patients with peripheral arterial thrombosis. Fifty-nine patients with arterial thrombosis (38 men, 21 women), ages ranging from 24 to 80 years, mean age, 45.5 years, were studied. The control group included 100 volunteer blood donors. After confirmation of the thrombotic event, anticardiolipin antibodies were dosed by the immunoassay enzyme method and by dilution. In Group I these antibodies were present in 62.7% of the patients, of which 33.9% were borderline and 28.8% were positive. In the control group 6% of the patients were borderline and 1% was positive. The statistical analysis showed that the prevalence found was statistically significant (p < 0.001), even when the borderline titers were not considered positive. Patients with peripheral arterial thrombosis have a high prevalence of anticardiolipin antibodies.

Adult↗

Mitral valve repair with a malleable bovine pericardium ring.

OBJECTIVE: To describe a surgical procedure utilizing a malleable bovine pericardium ring in mitral valve repair and clinical and Doppler echocardiographic results. METHODS: Thirty-two (25 female and 7 male) patients, aged between 9 and 66 (M=36.4+/-17.2) years, were studied over a 16-month period, with 100% follow-up. In 23 (72%) of the patients, the mitral approach was the only one applied; 9 patients underwent associated operations. The technique applied consisted of measuring the perimeter of the anterior leaflet and implanting, according to this measurement, a flexible bovine pericardium prosthesis for reinforcement and conformation of the posterior mitral annulus, reducing it to the perimeter of the anterior leaflet with adjustment of the valve apparatus. RESULTS: The patient survival ratio was 93.8%, with 2 (6.2%) fatal outcomes, one from unknown causes, the other due to left ventricular failure. Only one reoperation was performed. On Doppler echocardiography, 88% of the patients had functional recovery of the mitral valve (50% without and 38% with mild insufficiency and no hemodynamic repercussions). Of four (12%) of the remaining patients, 6% had moderate and 6% had accented insufficiency. Twenty-eight percent of class II patients and 72% of class III patients passed into classes I (65%), II (32%), and III (3%), according to NYHA classification criteria. CONCLUSION: Being flexible, the bovine pericardium ring fit perfectly into the valve annulus, taking into account its geometry and contractility. Valve repair was shown to be reproducible, demonstrating significant advantages during patient evolution, which did not require anticoagulation measures.

Adolescent↗

The chemical protecting group concept applied in crosslinking of natural tissues with glutaraldehyde acetals.

This work describes the results of the controlled crosslinking of collagen matrices by glutaraldehyde based on a double protection strategy, glutaraldehyde acetals and lysine protonation due to the acidic conditions of acetal formation. Materials crosslinked by this approach were characterized by thermal stability comparable to those obtained by conventional procedures with mechanical properties expected for bioprosthesis manufacture and with a higher stability toward collagenase hydrolysis. The integrity of the microfibrillar structure was confirmed by optical and scanning electronic microscopy. The results indicate that the glutaraldehyde acetals procedure may be of potential use for the crosslinking of bovine pericardium used in the manufacture of bioprosthetic devices. Advantages may be related to the production of materials with homogeneous crosslinking distributions, associated with better definition in the nature of the chemical link that they introduce, due to a better distribution of glutaraldehyde within the tissue matrix before the crosslinking reaction is allowed to occur. As a result, materials with improved biological and mechanical properties are expected.

Acetals↗

[Left atrial myxoma and isquemic stroke in a child].

The authors present a case of left atrial myxoma with stroke in an 8-year-old female child. The tumor was removed and two months after the surgery a left atrial septum mass was observed suggesting recurrence. The child was asymptomatic. Literature review emphasizes the rarity and clinically aggressive behavior of this tumor at this age group and demonstrates rare recurrence rates after surgery.

Brain Ischemia↗