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Biomedical subjects

F Amaral

Publications and source records attributed to F Amaral.

At least 19 recordsLinked to original sources
PubMed2005

Testosterone rapidly stimulates insulin release from isolated pancreatic islets through a non-genomic dependent mechanism.

The action of testosterone on the 45Ca2+ uptake and insulin secretion was studied in short-term experiments using isolated pancreatic islets of Langerhans. Testosterone (1 microM) stimulated 45Ca2+ uptake within 60 seconds of incubation on similar proportion than tolbutamide. Also, the hormone rapidly increased insulin release (34%; 180 seconds) on the presence of non-stimulatory concentrations of glucose (3 mM). Impermeant testosterone-BSA significantly stimulated the secretion of insulin to a lower percentage (10%). The action of the hormone is specific--neither 17beta-E2 nor progesterone stimulated insulin secretion in the presence of 3 mM glucose. The action of testosterone on insulin secretion was dose-dependent, and at rat plasma physiological concentrations (25 nM), stimulus was 17% (p < 0.05). In conclusion, in isolated pancreatic islets experiments, physiological concentration of testosterone rapidly stimulate insulin secretion and 45Ca2+ uptake through a membrane bound mechanism.

Animals↗
PubMed2001

Lymphatic filariasis in children: adenopathy and its evolution in two young girls.

Lymphatic filariasis is a widespread infectious disease of children in endemic areas, but little is known about the early lymphatic damage in children and its evolution, either with or without treatment. Two girls (ages 6 and 12 years) from a Wuchereria bancrofti endemic region of Brazil presented with chronic inguinal adenopathy. Neither had microfilaremia. By ultrasound both were shown to have living adult worms in their enlarged inguinal nodes and had occult local lymphatic damage (lymphangiectasis). One girl spontaneously developed acute adenitis in the affected node prior to any intervention; this adenitis resolved within 10 days and was associated with the progressive disappearance over 45-90 days of all local abnormalities detectable by ultrasound. In the other child, after treatment with a single dose of diethylcarbamazine (DEC), the same clinical picture of transient adenitis and resolving abnormalities (detectable by ultrasound) occurred. These findings demonstrated filariasis as the cause of adenopathy in children, and also both spontaneous and treatment-induced worm-death, with subsequent reversal of lymphatic abnormalities.

Animals↗
PubMed2000

Congenital atresia of the ostium of the left coronary artery. Diagnostic difficulty and successful surgical revascularization in two patients.

We report two cases of congenital atresia of the ostium of the left coronary artery. Case 1: a six-month-old infant presenting with serious cardiac insufficiency. A noninvasive diagnosis of dilated myocardiopathy was established and the clinical picture was pharmacologically compensated. When the patient was nine months of age, a hemodynamic study was performed that revealed congenital atresia of the ostium of the left coronary artery; the infant immediately underwent a successful anastomosis of the internal mammary artery with the left coronary artery. Case 2: an eleven-year-old asymptomatic boy with a history of heart murmur from the age of six months on, was referred for surgery with a diagnosis of anomalous origin of the left coronary artery from pulmonary trunk. A definitive diagnosis of atresia of the left coronary ostium was only established during surgery. Successful surgical revascularization with the left internal mammary artery, and left ventricular aneurysmectomy were performed.

Child↗
PubMed1999

Cardiologic evaluation of children with suspected heart disease: experience of a public outpatient clinic in Brazil.

CONTEXT: During initial evaluation of children on an outpatient basis, the index of suspected heart disease may be high, particularly if we consider that innocent murmur occurs in about 50% of the pediatric population. This is the most common cause of referral to the pediatric cardiologist. OBJECTIVE: To report on the experience of a public outpatient clinic in the southeastern region of Brazil. DESIGN: Retrospective analysis of all patients submitted to cardiologic evaluation within a 39 month period. SETTING: Public pediatric cardiology outpatient clinic. PARTICIPANTS: 2675 consecutive children aged</=15 years referred from the local and regional basic health units due to suspected heart disease. MAIN MEASUREMENTS: Reason for referral, diagnostic investigation, final diagnosis based on the reason for referral, therapeutic procedures. RESULTS: The main reasons for referral were: murmur (70%), precordial pain (9%), suspicion of arrhythmia (9%) and breathlessness (5%). Of the total number, 695 cases (26%) did not complete the investigation and were not included in the analysis. A final diagnosis was obtained based on the reason for referral and the main conclusions were: l) a high incidence of normality was found: murmur (83%), pain (98%), arrhythmia (97%) and breathless (94%); 2) heart disease was unlikely, based on other referral reasons; 3) 14% of the children were considered abnormal and 1% needed therapeutical procedures. CONCLUSIONS: The establishment of a pediatric cardiology outpatient clinic within the public health service in the region seems to be justifiable, due to the high current demand. The low global incidence of heart disease, with a high prevalence of children with innocent murmur, discloses the need for a specific training program in cardiology for pediatricians.

Ambulatory Care Facilities↗
PubMed1999

Anomalous origin of the left coronary artery from the pulmonary trunk. Clinical features and midterm results after surgical treatment.

OBJECTIVE: To report the authors' experience with the anomalous origin of the left coronary artery (AOLCA) from the pulmonary trunk, emphasizing preoperative data, surgical aspects and midterm results of the follow-up. METHODS: Retrospective analysis of 11 patients operated upon at the Royal Brompton Hospital from October, 84 to April, 97. RESULTS: Nine infants had heart failure (HF) and two other children presented with dyspnea and chest pain. All had ECG changes. The echocardio-gram identified the anomalous origin of the coronary artery in 7 (64%) patients and hemodynamic studies were performed in 7 patients. All infants were operated upon between the 2nd and 10th month of life. Six patients were treated with aortic reimplantation of the left coronary artery, whereas five were operated upon according to the Takeuchi technique. All patients are alive, with clear improvement of the ECG changes and ventricular function, as evaluated by echocardiography. Two patients operated upon according to the Takeuchi technique required additional surgery due to severe supravalvular pulmonary stenosis. CONCLUSION: AOLCA is a rare disease. Most patients show early signs of severe HF associated with ECG findings. Surgical therapy must be instituted early in the disease, preferentially through aortic implantation of the anomalous coronary artery, with a high possibility of success. Shortly after surgery, clinical and ECG improvement, as well as normalization of left ventricular function, should be expected.

Adolescent↗
PubMed1998

Ultrasonographic detection of living adult Wuchereria bancrofti using a 3.5-MHz transducer.

Adult Wuchereria bancrofti can be readily detected by ultrasound in the lymphatic vessels of the spermatic cord with a 7.5-MHz transducer, but most ultrasound machines in developing countries are equipped with 3.5-MHz transducers. To assess the potential for ultrasound as a tool for diagnosis and epidemiologic assessment in lymphatic filariasis, we compared the performance of 3.5-MHz and 7.5-MHz transducers in 61 men in Recife, Brazil. All men had three ultrasound examinations using a 3.5 MHz transducer and an examination with a 7.5-MHz probe. Using the 7.5-MHz transducer, adult W. bancrofti were detected in 41 men; 81 adult worm nests were detected. Sixty-four (79%) nests were detected with the 3.5-MHz probe, each on all three examinations. The 3.5-MHz probe correctly identified 35 (85.4%) of 41 men as infected; sensitivity increased with lymphatic vessel diameter. Ultrasonographic examination with a 3.5-MHz transducer is a sensitive method for detection of adult W. bancrofti in men and merits consideration as a tool for rapid epidemiologic assessment.

Adolescent↗
PubMed1997

Transfontanelle ultrasonography in infants: comparative study with cranial computed tomography.

The findings of transfontanelle ultrasonography, undertaken in 36 infants with clinical evidence of central nervous system (CNS) disorders, were compared with the findings of cranial computed tomography (CT). Considering the CT scan findings as gold standard, cranial ultrasonography had a sensitivity of 82 per cent and a specificity of 75 per cent in identifying cerebral pathology. The positive predictive value was 92 per cent and negative predictive value was 45 per cent.

Brain Diseases↗
PubMed1997

[Emergency percutaneous balloon mitral valvuloplasty in a pregnant woman].

We report the case of a 33-year-old woman in the 28th week of pregnancy and with signs of fetal death, admitted to hospital in an emergency due to pulmonary edema secondary to severe mitral valve stenosis. Intensive medical treatment was unsuccessful and the patient was submitted to an emergency percutaneous balloon mitral valvoplasty with prompt clinical improvement. Subsequent clinical deterioration secondary to fetal death was managed by cesarean section resulting in clinical establization. The patient was discharged 10 days after admission and at 11 months after the procedure she had mild symptoms without drug therapy and echocardiographic signs of mild residual mitral stenosis (mitral valve area: 2.0 cm2).

Acute Disease↗
PubMed1997

[Quality of life after surgical correction of the aorta coarctation. Retrospective analysis of a group of patients with long-term follow-up].

PURPOSE: To report on the long-term results after operation for coarctation of the aorta. METHODS: One hundred and four patients were studied, divided in four groups (G1, G2, G3 and G4), according to age at operation. Data analysed: reoperation, persistent hypertension, residual lesions, left ventricular function and ability index. RESULTS: Reoperation was frequent, mainly in G1 (60%) and G4 (29%). Resting hypertension occurred predominantly in cases operated on after the 10th year of life: 28% (G3) and 29% (G4). Exercise hypertension was found in cases operated on after the 20th year. Residual lesions were frequent: 97%, 98%, 83% and 65% (G1 to G4). Individual functional limitation was uncommon. The ability index was normal in the great majority of the patients (94%). CONCLUSION: Reoperation is frequent, particularly for recoarctation and aortic stenosis. Rest and/or exercise hypertension is common and related to delayed surgery. Aortic residual lesions are frequent. Physical limitation is uncommon. Postoperative follow-up is essential in order to detect late complications, which, usually, do not limit the individual patient.

Adolescent↗
PubMed1996

Ultrasonographic assessment of the adulticidal efficacy of repeat high-dose ivermectin in bancroftian filariasis.

Since diethylcarbamazine, the drug recommended for treatment of lymphatic filariasis, seems only partially effective against the adult worm, intense interest persists in identifying a macrofilaricidal drug for this infection. To evaluate directly in vivo the macrofilaricidal activity of repeat high-dose ivermectin, 15 men who had living adult Wuchereria bancrofti detected in the scrotal area by ultrasound were treated with 400 micrograms/kg of ivermectin at 2-week intervals for 6 months (total dose, 4.8 mg/kg). Serial ultrasound examinations were performed before, during, and for 6 months after treatment. Profound suppression of microfilaraemia followed the first dose of ivermectin, but movements characteristic of the adult worm on ultrasound remained unchanged both in location and pattern. Even when given in total doses of 4.8 mg/kg, ivermectin appears to have no observable activity against adult W. bancrofti, although its ability to suppress microfilaraemia makes it potentially useful for the control of lymphatic filariasis.

Adult↗
PubMed1994

Live adult worms detected by ultrasonography in human Bancroftian filariasis.

Ultrasonographic examination of the scrotal area was performed in 14 asymptomatic individuals with bancroftian filariasis and microfilaremia. While in seven subjects (50%) the ultrasonographic findings were normal, lymphatic dilation and tortuosity were observed in the other seven. In these vessels, structures with peculiar aleatory movements (filaria dance sign) were detected. A segment of the lymphatic tract containing these mobile intraluminal structures that was resected surgically from the left spermatic cord of one individual confirmed that these structures were living Wuchereria bancrofti adult worms (two females and one male). Our study demonstrates for the first time the feasibility of using a low-cost, widely available, noninvasive technique (ultrasonography) to detect and monitor living adult worms and lymphatic dilation in patients with bancroftian filariasis.

Adolescent↗
PubMedDate not supplied

Direct assessment of the adulticidal efficacy of a single dose of ivermectin in bancroftian filariasis.

Although the potent microfilaricidal activity of ivermectin is well established, its efficacy against adult Wuchereria bancrofti is unknown. We used longitudinal ultrasound examinations for periods of 3-9 months to assess directly the macrofilaricidal effect of a single 400 micrograms/kg dose of ivermectin in 15 men from Recife, Brazil who were infected with W. bancrofti. Before treatment, microfilarial densities ranged from 3 to 3098 microfilariae per mL of blood, and movements characteristic of the living adult worm (the 'filaria dance sign') were observed by ultrasound examination of the scrotal lymphatic vessels in all 15 men. Following treatment, microfilarial density was markedly reduced in all men, but the filaria dance sign remained unchanged in both location and pattern. Eight months after treatment, a dilated lymphatic vessel was surgically removed from one patient at the site of the filaria dance sign, and 3 intact adult worms were released. When given as a single 400 micrograms/kg dose, ivermectin had no observable effect on adult W. bancrofti. Therefore, prolonged suppression of microfilaraemia following treatment with ivermectin cannot be explained by a macrofilaricidal effect of the drug. Ultrasound is a valuable new tool for directly and rapidly assessing the macrofilaricidal efficacy of antifilarial drugs in lymphatic filariasis.

Adult↗