Biomedical subjects
Publications and source records attributed to I Machado.
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.
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.
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.
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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.
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.
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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.
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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.
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.
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.
Sixty per cent of the patients with immuno-compromise of the humoral compartment may show chronic diarrhoea, specially seen in the common variable hypogammaglobulinemia (CVH). We presented 3 cases of late-onset CVH who referred chronic diarrhoea as the main symptom. The immunodiagnosis revealed undetectable or subnormal immunoglobulins levels (G, M, A), preserved total haemolytic complement and a negative autoimmune screening. The cell compartment analysis showed increased number of suppressor T lymphocytes (CD8) plus hyporesponsiveness of the total peripheral lymphocytes to polyclonal mitogens such PHA. The clinical approach of the CVH patients should be performed by a multispecialized team including the clinical immunologist and the gastrointestinal and infectious diseases specialists.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.