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Biomedical subjects

I Machado

Publications and source records attributed to I Machado.

At least 19 recordsLinked to original sources
PubMed1998

Characterization of local memory cells in stage-classified pulmonary tuberculosis: preliminary observations.

Immunophenotype analysis and proliferative responses were investigated in bronchoalveolar lavage (BAL) cells from 21 patients with stage-classified tuberculosis: six with localized pulmonary infiltrate (LPI); seven with diffuse pulmonary infiltrate (DPI); and eight with pleural effusions (PE). Bronchoalveolar lavage cells from these patients contained a high number of cells/ml. The macrophage number was significantly lower in the DPI group (P < 0.05) compared to the LPI or PE groups. Conversely, neutrophils were markedly increased in DPI patients compared to LPI (P < 0.01) and PE (P < 0.01) patients. Lymphocyte infiltration (97.7 +/- 2.3% CD3+, > 83% alphabeta+ and CD4+ > CD8+) was observed in the three groups. A significant increase in the number of total lymphocytes (P < 0.01) and CD4+ cells (P < 0.05) was observed in the LPI group compared to the PE group. In the LPI group CD4+CD45RO+ cell infiltration was higher than CD4+CD45RA+ cells (P < 0.001), contrasting to similar numbers of these subpopulations in the DPI group. Lymphocytes from three out of three LPI patients (alphabeta+CD4+CD45RO+) responded against tuberculin purified protein derivative contrasting to the unresponsiveness of five patients with either DPI or PE. This impaired response was reverted in two out of five patients by using peripheral blood monocytes instead of alveolar macrophages. It is suggested that, in humans, alphabetaCD4+CD45RO cells are the main lymphocyte type involved in the initial local cell-mediated immune response against Mycobacterium tuberculosis.

Adolescent↗
PubMed1996

[Echocardiographic evaluation of the aortic and pulmonary valve areas in the newborn infant. Normal patterns].

OBJECTIVES: To determine normal values of the aortic and pulmonary functional valve areas in healthy newborn children. MATERIAL AND METHODS: We prospectively studied 32 newborns (17 boys) who were included in the following criteria: healthy parents, normal pregnancy, eutocic delivery, Apgar index 10 at 5 minutes weight between 2.500 and 4.000 kg, normal physical and echocardiographical examinations. The echocardiographical examination was executed during the first 48 hours of life. We used the continuity equation to calculate the aortic and pulmonary functional valve areas. As a reference we used the anatomic (pi r2) aortic and pulmonary valve areas, calculated in the bidimensional images from the distance measured between the two insertion points of the sigmoid valves. RESULTS: We had echocardiographic images and Doppler registrations of excellent quality, in all the newborn children. The functional pulmonary valve area ranged between 0.30 and 0.50 cm2 (mean +/- SD = 0.41 +/- 0.06) and the anatomical one ranged between 0.29 and 0.49 cm2 (mean +/- SD = 0.49 +/- 0.05), without statistical significance and with a correlation index 0.92. The functional aortic valve area ranged between 0.20 and 0.40 cm2 (mean +/- SD = 0.31 +/- 0.05) and the anatomical ranged between 0.21 and 0.36 cm2 (mean +/- SD = 0.29 +/- 0.05), without statistical significance and with a correlation index 0.91. CONCLUSION: There is a good correlation between the functional aortic and pulmonary valve areas, calculated from the continuity equation, and the anatomical ones. These values will be useful in characterizing the critical stenosis of the newborn child with decreased ventricular function, where the transvalvular gradient is inaccurate in the quantification of the obstruction.

Aortic Valve↗
PubMed1994

[Atrial myxoma. Apropos a clinical case].

The authors report a case of a 61-years-old woman with hypertension and palpitations, who was diagnosed as having a left auricular myxoma. This diagnosis was established by echocardiography and confirmed afterwards by an histological survey. On the basis of this case the authors reviewed the subject and discuss the role of echocardiography in the diagnosis and follow-up of this kind of patients.

Arrhythmias, Cardiac↗
PubMed1994

[Percutaneous closure of interatrial defect using the buttoned double-disk prosthesis].

BACKGROUND: Surgical repair is the procedure of choice for atrial septal defect correction. Even though surgical mortality is low (< 1%), morbidity is significant (anesthesia, thoracotomy, cardiopulmonary bypass, longer hospitalization and intensive care unit monitoring). Transcatheter methods to occlude atrial septal defects have been in development during the last two decades. We report our experience in Italy with the Sideris buttoned double-disk device. METHODS: From March 1992 to April 1993, 14 patients aged 20 months to 52 years, weight 10 to 82 kg, underwent transcatheter atrial septal defect occlusion with the Sideris buttoned device. The buttoned device is a miniaturized two disk device introduced through small venous sheaths (8-9 F). The diameter of atrial septal defects by echocardiography varied between 9 and 23 mm, while the balloon stretched diameter of the defects varied between 13 and 24 mm. The devices selected were 19 +/- 4 mm larger than the stretched diameter of the defect, but less than the total length of the septum (33-56 mm) by echo. RESULTS: Pulmonary-to-systemic flow ratio varied between 1.5 to 4.0. Mean pulmonary artery pressure varied between 10 and 24 mmHg (mean value 17 +/- 3.5 mm Hg). The relationship between different atrial septal defect measurements (echo, shunt flow, stretched diameter) was statistically analysed: transthoracic echo diameter had a good correlation with the balloon stretched diameter (r = 0.63, p < 0.001). The atrial septal defect was occluded in 12 patients (86% success rate). There was one early "unbuttoning" which was surgically corrected with success. The other patient underwent surgical correction 3 months later because of unsuitability for transcatheter closure. Minimal residual shunt detected by color flow mapping at 1 month follow-up was seen in 4 patients (33%). No complications occurred in any of our patients. CONCLUSIONS: This initial experience with the Sideris buttoned double-disk device demonstrated that transcatheter closure of atrial septal defect is feasible and effective. It can be accomplished through small introducing sheaths. Further clinical trials are justified. This method could become the procedure of choice for the correction of small ASDs.

Adolescent↗
PubMed1993

[Cardiac changes in a case of mitochondrial encephalomyopathy].

In the present article the authors describe a case of a twenty-one year-old patient with a mitochondrial encephalomyopathy presenting cardiac changes. Mitochondrial encephalomyopathy a multisystemic disease is described in various publications having cardiac involvement although there are sparse references about cardiomyopathy in this same disease. In the present case, the patient had a syndrome of both Mitochondrial Encephalopathy, Lactic Acidosis and Stroke like episodes (MELAS) and Myoclonic Epilepsy and Ragged Red Fibers (MERRF). There were no significant changes in the cardiac conductivity studied by ECG but an echocardiographic pattern of hypertrophic cardiomyopathy was found.

Adult↗
PubMed1985

Proliferative response in solid culture of T cells from healthy aged subjects.

T lymphocytes from healthy aged subjects were challenged with 12-O-tetradecanoylphorbol-13-acetate (TPA, a T-cell mitogen) in solid cultures and compared under the same experimental conditions to a group of younger controls. The aged cells showed diminished proliferation and incorporation of tritiated thymidine (3H-Tdr). However, when unfractionated peripheral blood mononuclear cells or isolated T cells from the aged individuals were cultured in the presence of 2-mercaptoethanol, autologous erythrocytes or co-cultured with a non-T cell fraction, an increased proliferative response was observed. Our results suggest that the reduction in proliferative capacity of aged T cells observed in liquid culture is also elicited in solid conditions. However, under appropriate signals a TPA-susceptible T-cell subpopulation may contribute significantly in enhancing their in vitro response. This in turn would suggest that age-related cellular changes are intrinsic in nature and not fully reversible with potentiating factors.

Adolescent↗
PubMed1981

Human colonic mononuclear cells: studies of cytotoxic function.

We isolated lymphocytes from the lamina propria of colon from 19 patients with inflammatory bowel disease, colon cancer, and certain benign conditions to determine: (1) if these lymphocytes could mediate mitogen-induced (MICC) and spontaneous cell-mediated cytotoxicity (SCMC), and (2) if there were any differences in cytotoxic effectiveness which could relate to the underlying disease. We found that lamina propria lymphocytes functioned well in MICC reactions with phytohaemagglutinin, but not concanavalin A as the inducing mitogen (specific lysis 28 5% vs 5 3%). Lamina propria lymphocytes did not mediate SCMC (specific lysis 0.3%). Neither the presence of inflammation not the underlying disease of the patient influenced the cytotoxic activity. Peripheral blood lymphocytes from normal subjects and patients performed well in MICC assay with both phytohaemagglutinin and concanvalin A as the inducing mitogen and were equally effective in SCMC reactions.

Colon↗
PubMed1975

Ascending aorta-right pulmonary artery anastomosis in children with complex cardiac malformations. Long-term results in 30 cases.

In this report, we shall analyze the results obtained with palliative treatment in 30 patients with congenital heart disease who were operated upon at the University Hospital of Caracas during the period 1968 to 1972. In all cases, an ascending aorta-right pulmonary artery anastomosis was performed. Although we believe that the Blalock-Taussig and Potts shunt are satisfactory operations in some cases, at the present time we prefer the aorta-right pulmonary branch anastomosis in Fallots tetralogy and other congenital heart diseases such as single ventricle. In Fallot's tetralogy, particularly, this procedure provides better results, because the anastomosis can be closed through the aorta when these patients are later subjected to total correction with extracorporeal circulation.

Adolescent↗
PubMed1970

Wilms' tumour propagated through the inferior vena cava into the right heart cavities.

A report is made of a rare case of Wilms' tumour which simulated clinically a syndrome of ;right heart failure', as found in some cases of Ebstein's disease. The clinical, radiological, and electrocardiographic study led to the suspicion of this type of malformation. The cine-angiographic study revealed two important facts: the impossibility of approaching the inferior vena cava with opaque material injected into the azygos vein and a filling defect of the right atrium. The post-mortem study revealed the presence of a Wilms' tumour of the right kidney which extended into the inferior vena cava and into the right atrium without producing metastases. This seems to be the first case of this peculiar course of a Wilm's tumour which has grown into the right atrium, resulting in this bizarre clinical picture.

Child, Preschool↗
PubMedDate not supplied

[Single ventricle. II. Clinical study. Special studies and surgical treatment].

A study was made of 29 cases of single ventricle confirmed by autopsy, hemodynamic study, or both. It must be emphasized that the term single ventricle excludes whatever malformation which shows traces of an intraventricular septum. Thus conceived, the malformation has been seen to have different clinical courses, which only permit partial diagnosis that may suggest the possibility of "single ventricle". In live patients this can only be diagnosed with specialized studies. In outline, there exist 4 types of clinical hemodynamic behavior: 1) The type with marked increase of pulmonary flow, in which the single cavity vascular systems, pulmonary and aortic, had similar pressures. This type behaves, in a certain way, like large interventricular communications. 2) The type which behaves hemodynamically like a large hypertensive communication with delayed cyanosis of rapid evolution and with few manifestations of heart failure. 3) The third type also has pulmonary hypertension with delayed cyanosis. This differs from the preceeding in that there is a preferential flow in such a way that the venous blood proceeding from the right atrium empties into the aorta and the arterial blood from the left atrium empties into the pulmonary artery. 4) The fourth type is characterized by rapid cyanosis and from the anatomical point of view has stenosis or atresia of the pulmonary artery. An analysis was made of the varieties which within these four classes actually ocurred or cases which were present as theoretical possibilities: single ventricle with crossed great arteries; single ventricle with transposition of the great arteries; single ventricle with partial distortion of the great arteries; single ventricle with common trunc. A detailed analysis was made of the clinical, hemodynamic, electrocardiographic, and radiological manifestations which are seen in these combinations and an anatomic-embriologic classification is proposed on the basis of the systematization of the 29 cases of the present study. Finally brief considerations are made of the operability of those cases of single ventricle according to their anatomic variety.

Angiocardiography↗
PubMedDate not supplied

[Risk of occupational exposure to hepatitis B virus in Venezuelan health workers. Multicenter study].

In a multicenter study, 970 serum samples were collected from venezuelan health workers. Presence of HBV serological markers (HBsAg, antiHBs and total anticore) were screened by microELISA. Two-hundred and forty-seven samples (27%) showed at least one positive marker, being the most frequently found the antisurface antibody which was present in different working areas, including those considered at the low exposure level (medicine 24.7%). The proportion of antisurface positive samples also was significantly higher in the group with more than 10 years of service compared to the prevalence showed by the group with less than 5 years (19.1 vs 12.8%). Groups considered to be at low risk, contrary to the expected results, showed a similar or higher prevalence compared to the groups classified as continues or frequent exposure (17.7 vs 8.6%). Our findings suggest a permanent HBV load circulation at the venezuelan hospitals environment.

Biomarkers↗
PubMedDate not supplied

[Chronic infection due to hepatitis B virus in patients less than 16 years of age: therapeutic approach by means of interferon alfa-2b].

Twenty children with chronic Hepatitis B virus infection where treated with alfa interferon 2b and compared with a group of 24 non treated patients with similar age and sex distribution. Both treated and untreated patients, all Hepatitis B surface antigen positive for a minimum of 6 months, were divided in 2 groups according to HBeAg status: positive and negative. The treatment was ambulatory at a dose of 5.000.000 U per square meter of body surface, administered 3 times a week during 16 weeks. Tolerance of the drug was good with secondary reactions only at the beginning of the treatment. The only change in laboratory tests was the normalization of aminotransferases in HBeAg positive children. There was no significant difference between the treated and untreated group of HBeAg positive patients regarding the rate of HBeAg seroconversion. There was a striking difference in negativization of HBsAg in HBeAg negative patients: 8% in the treated group and 81% in the untreated group, this is explained by important epidemiological differences between both groups.

Adolescent↗