PubMed HealthSearch

Biomedical subjects

A C Carvalho

Publications and source records attributed to A C Carvalho.

At least 19 recordsLinked to original sources

Absence of an aortic valve cusp, a cause of severe aortic regurgitation in infancy.

Congenital aortic regurgitation is an extremely rare cardiac lesion. This is a case report of an infant with a severe degree of valve regurgitation due to absence of the noncoronary aortic cusp. We show the echocardiographic, angiographic, and surgical aspects of the case, emphasizing the importance of a precise anatomical diagnosis and the problems of early valve replacement.

Angiocardiography

Pregnancy in patients with prosthetic heart valves: the effects of anticoagulation on mother, fetus, and neonate.

Maternal and fetal complications in a consecutive series of 60 pregnancies in 49 patients with prosthetic heart valves were prospectively evaluated. Group 1 consisted of 40 pregnancies in 31 patients who were taking oral anticoagulants. No oral anticoagulation was used in 20 pregnancies in 19 patients (group 2). In group 1 there were three instances of acute valvular thrombosis during the 35 pregnancies in patients with mechanical prostheses, with two maternal deaths. There were two episodes of cerebral embolism, one in group 1 and one in group 2. Patients with isolated aortic valve replacement had fewer maternal complications (2 of 13) than patients with isolated mitral valve replacement (15 of 42) without statistical significance. Severe bioprosthesis dysfunction occurred in 4 of 25 pregnancies (one rupture and three stenosis) with two maternal deaths, one in the puerperium and the other in the postoperative period of cardiac surgery during pregnancy. When analyzing obstetric events we observed seven spontaneous abortions and one hydatidiform mole. All spontaneous abortions occurred in group 1. The incidences of prematurity and low birth weight were significantly higher in group 1 than in group 2 (46.6% vs 10.5%, p less than 0.05, and 50% vs 10.5%, p less than 0.05, respectively). Moreover, there was a significant association between prematurity and the mother's New York Heart Association functional class (61.5% in classes III and IV vs 22.2% in classes I and II, p less than 0.05). There were five neonatal deaths, all in group 1 (p = NS vs group 2). Three infants had warfarin-related congenital defects.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced

Lung and myocardial thallium-201 kinetics in resting patients with congestive heart failure: correlation with pulmonary capillary wedge pressure.

Increased lung thallium-201 activity occurs with exercise in patients with severe coronary artery disease as a result of increased pulmonary capillary wedge pressure. No study has shown resting lung kinetics in chronic congestive heart failure. To better understand the relationship between lung and myocardial thallium uptake and pulmonary capillary wedge pressure, this study was performed. Resting lung and myocardial thallium uptake, expressed as a ratio, were compared with simultaneous pulmonary capillary wedge pressure in 16 patients with congestive heart failure and cardiomyopathy, all New York Heart Association class IV. There were no variations in pulmonary capillary wedge pressure throughout the study protocol. There was a significant reduction in the lung/myocardium thallium ratio from 10 to 60 minutes (0.83 +/- 0.30 to 0.59 +/- 0.17; p less than 0.001). At 60 minutes after thallium injection there was a linear correlation between the lung/myocardium ratio and capillary wedge pressure with an r value of 0.62 (p less than 0.01). Thus thallium-201 washout is rapid despite persistence of pulmonary capillary wedge pressure elevation, indicating that clearance does not imply resolution of congestive heart failure. In addition, a significant but imprecise correlation was found between capillary pressure and the lung/myocardium ratio. Rapid changes in lung activity during the early postinjection period may limit the clinical use of the lung/myocardium ratio.

Catheterization, Swan-Ganz

Symptomatic cardiac involvement in juvenile rheumatoid arthritis.

In a retrospective study of 172 patients with juvenile rheumatoid arthritis, symptomatic cardiac involvement occurred in 13 (7.6%) patients (11 systemic and 2 polyarticular). There was predominance of the male sex and in most patients the involvement occurred in the initial years of the disease. Pericarditis occurred in seven patients; perimyocarditis in four and myocarditis in two patients. In the follow-up, one of the patients with pericarditis died of an arrhythmia during pericardiocentesis for cardiac tamponade. Among the patients with myocarditis, three died of septicemia during active disease. One of these three patients had myocarditis associated with cardiac tamponade. Among the 172 patients with juvenile rheumatoid arthritis, five children died; four belonged to the symptomatic cardiac involvement group (P less than 0.001). Cardiac involvement, in particular myocarditis and cardiac tamponade, can be regarded as a factor of worse prognosis.

Adolescent

Cardiopulmonary exercise testing early after catheter-balloon mitral valvuloplasty in patients with mitral stenosis.

Seven female patients (age 27 to 53 yr) with significant mitral stenosis performed continuous, incremental, maximal treadmill exercise tests the day before and within 3-5 days after catheter-balloon valvuloplasty. Mitral valve area determined by the echo-Doppler method increased from 0.9 +/- 0.3 cm2 to 1.9 +/- 0.7 cm2 (p < 0.02). Mean left atrial pressure was reduced from 24 +/- 8 to 13 +/- 7 mmHg (p < 0.01) and mean pulmonary artery pressure from 36 +/- 13 to 28 +/- 10 mmHg (p < 0.02) with a non-significant increase in cardiac output from 3.6 +/- 1.2 to 4.0 +/- 1.7 l/min. After catheter-balloon valvuloplasty all patients reached a higher maximal workload during exercise, and mean value of oxygen consumption and pulmonary ventilation were significantly lower in submaximal workloads. The calculated ventilatory equivalent for oxygen was significantly reduced in submaximal and in maximal workloads after catheter-balloon valvuloplasty. Peak oxygen consumption and the ventilatory anaerobic threshold were not changed after catheter-balloon valvuloplasty (pre 15.59 +/- 2.72 vs post 16.90 +/- 3.44 and pre 12.10 +/- 2.55 vs post 12.62 +/- 2.71 ml/kg/min, respectively). We concluded that after catheter-balloon valvuloplasty the cost of breathing was reduced and the oxygen consumed was more effectively utilized during exercise. Increases in peak oxygen consumption and in ventilatory anaerobic threshold would require circulatory and metabolic adaptations in response to increased physical activity and were not observed when cardiopulmonary tests were performed early after catheter-balloon valvuloplasty.

Adult

Protein S and C alterations in acutely ill patients.

Protein C, a potent vitamin K-dependent protein activated by an endothelial cell cofactor, thrombomodulin, has anticoagulant and profibrinolytic activity. Free protein S, a cofactor for protein C, potentiates protein C activity at the endothelial cell surface. Pulmonary thromboemboli are a consistent finding in adult respiratory distress syndrome (ARDS). To determine if protein S or protein C were affected by widespread endothelial cell damage in ARDS, we measured bound and free protein S levels and protein C antigenic and functional levels in 18 patients with acute lung injury, 6 critically ill patients without lung history, and 22 normal subjects. Free (PS:F) and bound (PS:Ag) protein S and protein C antigen (PC:Ag) levels were measured using an enzyme-linked immunoassay and protein C function (PC:Fn) by measuring its anticoagulant activity. We found a significant decrease in bound and free protein S levels of both patient groups in comparison to normal and a shift toward the inactive, bound protein S form. In addition, a significant decrease in free protein S compared to bound protein S in both patient groups was observed. While both PC:Ag and PC:Fn were significantly reduced compared to normal, the PC:Fn was significantly and severely decreased out of proportion to the PC:Ag in both patient groups. There was no difference between those with and without lung injury for both protein S and protein C. Analyzed according to etiology of lung injury, there was no difference in the bound and free protein S, nor in PC:Ag and PC:Fn levels between patients with sepsis and trauma. However, there were significant decreases in both protein S and protein C levels compared with normal subjects. Levels of both PS and PC levels in patients who survived did not differ from those who died. In summary, our data show that both protein S and C are markedly deranged in acutely ill patients who suffered from either sepsis or trauma, and these changes are independent of lung injury. The marked reductions in functional activity of PS and PC may be contributing factors to the thromboembolic complications often observed in these patients.

Acute Disease

Histopathological study of porcine gastric mucosa with and without a spiral bacterium ("Gastrospirillum suis").

Tightly spiralled bacteria ("Gastrospirillum suis") were seen in the pyloric mucosa of the stomach of 13 (10.8%) of 120 pigs that appeared clinically healthy at slaughter and in the fundic mucosa of three (5.0%) out of 60 pigs. The spiral organism could not be cultured from any pig. Chronic gastritis was observed in the pyloric mucosa of 53 (44.2%) of 120 pigs and in the fundic mucosa of 7 (11.7%) of 60 pigs. The 13 pigs with spiral bacteria in the pyloric region comprised one animal (7.7%) with normal pyloric mucosa, two (15.4%) with "borderline gastritis", and 10 (76.9%) with chronic gastritis--in one instance accompanied by signs of activity (numerous polymorphonuclear cells). The three pigs with spiral bacteria in the fundic mucosa comprised two animals with a normal fundic region and one with "borderline gastritis". The presence of the spiral bacterium was significantly associated with pyloric gastritis (p = 0.013) and with numbers of lymphoid follicles (p = 0.014).

Animals

Virulence factors in Escherichia coli strains isolated from pigs in the Ribeirao Preto region, State of Sao Paulo, Brazil.

Three-hundred faecal swabs were obtained from pigs with diarrhoea in farms located in different areas of the Ribeirao Preto region in the State of Sao Paulo. One-hundred Escherichia coli strains were isolated and tested for production of thermolabile (TL) and thermostable (STRa and STb) enterotoxins, and for the presence of colonization factors F4, F5 and F6. The strains were also tested for sensitivity to 14 antibiotics and chemotherapeutic agents. Twenty-four Escherichia coli strains produced enterotoxin STb, 5 produced LT and 3 produced STa. In the mannose-resistant haemagglutination reaction, one strain reacted positively with sheep, chicken, horse and human red blood cells and another reacted positively with guinea pig, sheep, chicken, horse and human red cells. However, both strains were negative for colonization factors F4, F5 and F6 when submitted to the slide agglutination test. All Escherichia coli strains were resistant to at least one antibiotic, the highest percentages being obtained for resistance to penicillin, tetracycline and cephalotin. In addition to the importance of the virulence factors normally encountered in enterotoxigenic Escherichia coli strains from pigs, the present results show the possible existence of new colonization factors other than F4, F5 and F6 participating in E. coli-induced pigs colibacillosis in the Ribeirao Preto region.

Animals

[Pulmonary artery pressure evaluation in adults by Doppler echocardiography].

PURPOSE: To assess the role of pulsed Doppler echocardiography (PDE) in the indirect assessment of pulmonary artery (PA) pressure (P), analysing the pulmonary velocity blood flow curves (PVBFC) profile. PATIENTS AND METHODS: Sixty-one adults with several kinds of heart disease were submitted to heart catheterization to obtain PAP (systolic, diastolic, mean), and other hemodynamic variables. A PDE examination was performed in all to obtain the PVBFC at the level of the pulmonic annulus. Qualitative features of the curve were analysed (morphological pattern, presence of pulmonic regurgitation) as well as quantitative data (acceleration time = AT, right ventricle ejection time = RVET index, AT/RVET index AT corrected for heart rate = ATC), which were compared to the invasive measurements. RESULTS: An abnormal rapid acceleration of the PVBFC, with triangular configuration, was noted in patient with pulmonary hypertension (PH), in contrast to the dome-like shape of the PVBFC in normal PAP. Pulmonary regurgitation was more frequent (p less than 0.05) in patients with severe PH (mean PAP greater than or equal to 40 mmHg), comparing with patients with PAP less than 40 mmHg. Inverse linear correlations were observed between AT and mean PAP, particularly when sinus rhythm was present (r = 0.89; p less than 0.05) excluding patients with atrial fibrilation (19 cases). CONCLUSION: PDE is an useful and noninvasive method for indirect evaluation of PAP in adults, especially during stable sinus rhythm, in heart rate range from 60 to 115 bpm.

Adolescent

[Systemic-pulmonary shunts in congenital heart diseases with decreased pulmonary blood flow: critical analysis of the surgical techniques and immediate results].

PURPOSE: To evaluate immediate postoperative results in children with congenital heart disease and decreased pulmonary blood flow who underwent a systemic to pulmonary shunt. PATIENTS AND METHODS: Sixty-four patients underwent surgery, 46.8% (30) of them males with ages from 1 day to 17 years old. They were divided in three groups: I--13 pts (20.3%) who underwent classical Blalock-Taussig (BT) shunt; II--46 pts (71.8%) who underwent modified BT shunts, 34 of them with polytetrafluoroetylene (PTFE) and 12 of them with umbilical vein shunts; III--5 pts (7.8%) with central anastomosis that were made with three different types of graft; 3 PTFE, umbilical vein and bovine mammary artery in one each. The simultaneous procedures were: section and suture of PDA--2, closure of systemic-pulmonary collaterals--3, pulmonary valvotomy--3, right ventricular outflow patch--3, pulmonary branch stenosis (enlargement)--2. RESULTS: In group I there were 4 (30.7%) closures, with two immediate reoperation and a total mortality of 30.7%. In group II there were 4 closures (8.6%) and two reoperations with a mortality of 15.2% (7 cases). In group III there was one graft closure and an overall mortality of 80% (4 pts). When analysing deaths due to the shunt itself the mortality rate was respectively 15.3%, 8.6% and 40.0%. CONCLUSION: Modified BT operation was performed most frequently in our service; it was associated with less closure and mortality than the other types of shunt. It is considered our first alternative for a systemic-pulmonary shunt.

Adolescent

Thromboxane and prostacyclin release after endotoxin infusion in the rat.

To determine in the rat whether pulmonary artery hypertension accompanies thromboxane release, we sequentially monitored pulmonary and systemic artery pressures and cardiac output. We measured pulmonary and aortic plasma levels of TxB2 as well as 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) in awake unrestrained adult male Sprague-Dawley rats given a single infusion of endotoxin at the relatively high dose commonly administered to this endotoxin-resistant species. At 40 min after endotoxin infusion, both pulmonary and aortic TxB2 and 6-keto-PGF1 alpha levels increased nine-fold and seven-fold above baseline, respectively. In the pulmonary artery, 40 min after infusion, both mediator levels differed significantly from baseline (p less than 0.05), whereas in the aorta, because of marked variance in the response of different animals, only the 6-keto-PGF1 alpha levels achieved significance (p less than 0.05). These changes were associated with a fall in systemic blood pressure and cardiac output, but no demonstrable rise in pulmonary artery pressure (PAP). Despite ultrastructural evidence of vascular injury, these data indicate that in the rat thromboxane and prostacyclin release following a single infusion of endotoxin is not associated with pulmonary hypertension and that increased prostacyclin production may contribute to systemic hypotension.

6-Ketoprostaglandin F1 alpha

A spiral microorganism in the stomach of pigs.

Light and electron microscopic and microbiologic evaluations were performed on mucosa of stomachs from 120 healthy slaughtered pigs. Helicobacter pylori was not found, but a tightly spiralled bacterium, not previously described, was seen in histological sections and/or in carbol fuchsin stained smears in 13 (10.8%) stomachs. In paraffin sections stained with carbol fuchsin, the bacteria were seen in the mucus of the lumen of the antral pits and in the mucosa surface within and beneath the mucus. In this sections of Polilyte embedded tissue the bacteria had three to eight spiral turns per cell (mean = five), flattened ends, a Gram-negative cell-wall structure and a sheathed flagella. The urease test was positive in gastric mucosa of 13 bacteria-positive pigs (10.8%). The microorganism was not cultured and did not cross-react with polyclonal antibodies raised in rabbits against H. pylori. Superficial chronic gastritis and "borderline" gastritis were observed in antral mucosa of 10 (76.9%) and of two (15.4%) spiral bacteria-positive pigs, respectively.

Animals

Acquired platelet dysfunction in patients with uremia.

The current status of knowledge of the uremic hemorrhagic diathesis is reviewed. Discussions of clinical features, classification and pathogenesis, retention products and hemostatic defects, and therapy are included.

Blood Coagulation Factors

Activation of the contact system of plasma proteolysis in the adult respiratory distress syndrome.

Adult respiratory distress syndrome (ARDS) is a complex pulmonary clinicopathologic condition associated with pulmonary endothelial injury and blood coagulation activation. In patients with ARDS from all causes, factor VII levels were significantly reduced. Patients with ARDS caused by sepsis had more evidence of intravascular coagulation and fibrinolysis than did patients with trauma-related ARDS by having significantly (p less than or equal to 0.05) increased prothrombin times, activated partial thromboplastin times, and fibrin degradation products, and decreased antithrombin III concentration. We sought to determine whether the proteins of the contact system of plasma proteolysis (factor XII, prekallikrein, high molecular weight kininogen, and C1 inhibitor) were also activated after acute lung injury. Patients with ARDS caused by either trauma or sepsis had significantly (p less than or equal to 0.01) reduced factor XII levels, high molecular weight kininogen functional activity, prekallikrein activity, and prekallikrein antigen levels compared with controls. In both the sepsis-related and trauma-related ARDS groups, C1 inhibitor activity was significantly reduced but C1 inhibitor antigen levels were significantly elevated from control. These findings showed that the proteins of the contact system were more extensively activated in ARDS than were the proteins that contribute to later reactions in intravascular coagulation and fibrinolysis. Activation of the contact system proteins could be the result of endothelial injury occurring as part of ARDS. Intravascular coagulation and fibrinolysis in patients with ARDS also arise from components independent from contact system activation.

Blood Coagulation