Search PubMed⌕ Search

Biomedical subjects

A Cabrera

Publications and source records attributed to A Cabrera.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Changes in the left ventricular function with growing doses of dobutamine in healthy individuals].

The study aimed to assess ventricular function in response to increasing doses of dobutamine in healthy young volunteers. Isotopic ventriculography was performed at baseline, low dose (10 microg/Kg/min) and high dose (40 microg/Kg/min) of dobutamine. Global and segmentary ejection fraction, ejection fraction in the first third of systole, peak filling rate and peak filling rate time were analysed. A progressive increase in the global ejection fraction in relation to the increasing doses was observed. The segmentary ejection fraction and ejection fraction in the first third of systole also increased with the low dose, but no significant differences were found between both doses. Concerning the diastolic function, the peak filling rate increased significantly with both doses, with no differences between them. We conclude that dobutamine at these doses leads to an increase in all systolic parameters and in the peak filling rate without changing the peak filling rate time in healthy subjects.

Adolescent↗
PubMed1999

[Thallium-201 uptake in lung and heart with different types of stress. Study in healthy volunteers].

Forty healthy male volunteers, aged 1,7 +/- 0.9 years, were studied to verify any possible differences in lung and heart Thallium-201 uptake with different types of stress. All of them were studied with myocardial perfusion SPECT after the injection of 201Thallium. The 40 individuals were randomized into four groups of 10 subjects and each group was subjected to a different type of stress: physical exercise, dobutamine, dipyridamole and adenosine triphosphate (ATP). Significant differences were observed with regard to lung and heart 201Thallium uptake, both of them being lower with physical exercise than with any of the drugs. However, the lung/heart ratio was equivalent for all the groups. We conclude that, even though physical exercise induces a lower lung and heart 201Thallium uptake than does pharmacological stress, the lung/heart ratio is comparable in the four types of stress and has a value of 0.28 +/- 0.03 in healthy young subjects.

Adenosine Triphosphate↗
PubMed1999

Stent implantation in a central aorto-pulmonary shunt.

A 5.5-week-old infant with tricuspid atresia presented with severe hypoxemia not responding to the placement of a central shunt (4 mm polytetrafluorethylene). The infant was taken to the catheterization laboratory, where an AVE stent was successfully implanted in a severe postoperative stenosis, at the pulmonary end of the anastomosis. The oxygen saturation improved significantly, however, the infant died due to renal failure. The post-mortem anatomical findings are shown.

Aorta↗
PubMed1998

[Bacterial endocarditis in the aortic valve of a three month old infant. Correction with an aortic homograft].

We report the case of a three-month-old infant with an infective endocarditis of the aortic valve, showing perforation of two valve leaflets and a perivalvular abscess. The patient was operated on using a cryopreservated homograft with anastomosis of both coronary arteries. The outcome is good two years after surgery. This is the youngest patient operated on using this technique in our country.

Aortic Valve↗
PubMed1997

Sequential computerized tomography changes and related final outcome in severe head injury patients.

The authors analysed the serial computerized tomography (CT) findings in a large series of severely head injured patients in order to assess the variability in gross intracranial pathology through the acute posttraumatic period and determine the most common patterns of CT change. A second aim was to compare the prognostic significance of the different CT diagnostic categories used in the study (Traumatic Coma Data Bank CT pathological classification) when gleaned either from the initial (postadmission) or the control CT scans, and determine the extent to which having a second CT scan provides more prognostic information than only one scan. 92 patients (13.3% of the total population) died soon after injury. Of the 587 who survived long enough to have at least one control CT scan 23.6% developed new diffuse brain swelling, and 20.9% new focal mass lesions most of which had to be evacuated. The relative risk for requiring a delayed operation as related to the diagnostic category established by using the initial CT scans was by decreasing order: diffuse injury IV (30.7%), diffuse injury III (30.5%), non evacuated mass (20%), evacuated mass (20.2%), diffuse injury II (12.1%), and diffuse injury I (8.6%). Overall, 51.2% of the patients developed significant CT changes (for worse or better) occurring either spontaneously or following surgery, and their final outcomes were more closely related to the control than to the initial CT diagnoses. In fact, the final outcome was more accurately predicted by using the control CT scans (81.2% of the cases) than by using the initial CT scans (71.5% of the cases only). Since the majority of relevant CT changes developed within 48 hours after injury a pathological categorization made by using an early control CT scan seems to be most useful for prognostic purposes. Prognosis associated with the CT pathological categories used in the study was similar independently of the moment of the acute posttraumatic period at which diagnoses were made.

Adolescent↗
PubMed1997

[Experience with Palmaz stent in pulmonary branch stenosis].

INTRODUCTION AND OBJECTIVES: Since 1989, the balloon expandable Palmaz stent (Johnson & Johnson Interventional Systems) has been used for the treatment of congenital heart disease. This study reports the results and the technique used for its implantation in native and post surgical retraction pulmonary branch stenosis. MATERIALS AND METHODS: From february 1995 to june 1996, we have performed this technique in 11 symptomatic children/adolescents with pulmonary branch stenosis, the mean age was 11 +/- 2 years. Fourteen procedures were made and 16 stents were implanted. The mean condition of the patients was: 7 with tetralogy of Fallot after a previous complete correction, 1 with Noonan syndrome and a surgically corrected atrial septal defect, 1 with pulmonary trunk aneurysm and a previous surgical correction for pulmonary valve and branch stenosis, 1 with pulmonary atresia and an intact septum who underwent a surgical valvotomy and posterior percutaneous valvuloplasty with a good ventricular development, and final was a tricuspid atresia with a previous Waterston anastomosis which produced a stenosis at the right pulmonary branch who underwent a modified Fontan operation with the result of a severe stenosis at the medial and inferior right pulmonary artery. The branch ostium was affected in five cases, and in one case with diffuse hypoplasia of the right branch, the stenosis was at both sites. The stenosis was native in nine cases and post surgery in the other five (2 Waterston, 1 Blalock-Taussig, 1 Fontan). We used the right and/or left femoral vein in all cases except two, in which we used the internal jugular vein. We followed the technique reported by the Boston-Houston experience, with an extra stiff guide and Mullins sheath towards the site of the stenosis. RESULTS: The procedure was effective in all cases except one. The mean pulmonary branch and balloon diameter was 11 +/- 3 mm and 14 +/- 2 mm, respectively, rate 1.2. The stenosis diameter rose from 4.8 +/- 1 to 11 +/- 2 mm (p < 0.001) with a percentage fall from 63 +/- 5 to 2 +/- 1% (p < 0.001). The pressure gradient fell from 30 +/- 5 to 5 +/- 1 mmHg (p < 0.001) and the right ventricle systolic pressure fell from 77 +/- 6 to 48 +/- 3 mmHg (p < 0.01). The mean followup was 10 +/- 3 months, a symptomatic and pulmonary perfusion improvement was seen. After 8 +/- 4 months, we evaluated six patients/nine stents with angiography, and we excluded thrombosis, aneurysms and occlusion of lobar or segmental branches. One case had a proximal stent re-stenosis as it did not cover the whole stenosis, so a new stent was implanted. Three patients/four stents underwent redilatation getting a slightly higher diameter than previously. COMPLICATIONS: One patient had a stent migration and he underwent surgical stent retrieval. CONCLUSIONS: Implantation of the Palmaz stent is a useful procedure for the treatment of native or post-operative pulmonary stenosis. It is possible to apply it to hypoplastic and ostial pulmonary stenosis. We confirm the effectiveness of redilatation at mid term.

Adolescent↗
PubMed1997

[Isotopic ventriculography in healthy young volunteers. Their response to different types of stress].

BACKGROUND: Due to the increasing use of pharmacologic stress tests and the lack of comparative studies on ventricular function, this study was designed to establish the average limits in ventricular function with different kinds of stress, and to compare the response among them. METHODS: A randomized, open, controlled phase II clinical trial in 4 parallel groups was designed. Forty healthy male volunteers between 18 and 25 years were randomized into 4 groups of 10 individuals each: physical exercise (group 1), dobutamine (group 2), adenosine triphosphate (ATP) (group 3) and dipyridamole (group 4). Each volunteer underwent equilibrium radionuclide angiography, at rest and during stress. RESULTS: The global and regional ejection fraction increased significantly with the 4 kinds of stress. The maximal increase was reached with dobutamine and the minimal with dipyridamole. Physical exercise induced an increase in global ejection of 13 +/- 5%; dobutamine 16 +/- 6%; ATP 9 +/- 3% and dipyridamole 4 +/- 3%. CONCLUSIONS: The global and regional ejection fraction increases significantly more with dobutamine than with the other stress tests. Dipyridamole elicits the minimal increase.

Adenosine Triphosphate↗
PubMed1997

Superior mesenteric arterial embolism: local fibrinolytic treatment with urokinase.

PURPOSE: To evaluate the efficacy of intraarterial urokinase in the treatment of superior mesenteric arterial (SMA) embolism. MATERIALS AND METHODS: Within 3 years, 10 patients (six men, four women; aged 62-82 years) with angiographically proved SMA emboli were selected on the basis of absence of peritoneal signs of intestinal necrosis at physical examination and normal abdominal plain radiographs to undergo local lysis with urokinase. RESULTS: The procedure was performed without complications in all 10 patients. The embolus was successfully lysed in nine patients (90%). Clinical success was achieved in seven patients (70%); however, in one patient laparotomy was required to confirm the clinical finding. None of these patients had recurrent embolism or postischemic intestinal stenosis during follow-up (mean, 11.2 months). The three remaining patients (30%) underwent laparotomy subsequent to failure of intraarterial treatment with urokinase. CONCLUSION: Fibrinolytic treatment with urokinase may be an effective alternative to surgical embolectomy in patients with SMA embolism without clinical or radiologic signs of intestinal infarction. In this small series, abatement of abdominal pain in the 1st hour of fibrinolytic treatment was the best indicator of clinical success. Pain persisted in patients with intestinal infarction.

Aged↗
PubMed1997

Delivery rates for preventive services in 44 midwestern clinics.

OBJECTIVE: To determine the rates at which private primary-care clinics are recommending blood pressure and cholesterol measurement, smoking cessation, clinical breast examination, screening mammography, Papanicolaou testing, and influenza and pneumococcus immunizations. MATERIAL AND METHODS: We conducted a mail survey of 7,997 randomly selected patients from 44 primary-care clinics in and around Minneapolis-St. Paul, Minnesota, of whom 6,830 (85.4%) completed the questionnaire on preventive services delivery rates. The responses were analyzed statistically, including stratification by reason for the clinic visit. RESULTS: On the average, about two-thirds of the patients in each clinic reported being up-to-date on preventive services before their clinic visit; an exception was pneumococcus immunization (mean rate, 33%). Except for blood pressure and smoking cessation advice, less than 30% of patients who were not up-to-date on a preventive service were offered it if the clinic visit was for a reason other than a checkup or physical examination. For patients who said that they saw their physician for a checkup or physical examination, the rate was more than 50% only for Papanicolaou smear. In contrast, nearly all responding practitioners agreed that each of the eight preventive services was very important or important. CONCLUSION: Preventive services consensus goals are not being met, even for patients who report that their clinic visit was for a checkup or physical examination. This finding suggests that it may be necessary to develop clinical systems that support and enable the delivery of preventive services.

Adult↗
PubMed1997

Suprasellar papillary squamous craniopharyngioma. A case report.

Papillary squamous craniopharyngioma is an unusual variant of craniopharyngioma that presents almost exclusively in adults. We report a case of a 51-year-old man, who presented with visual and mental symptoms. A CT scan showed a suprasellar and intraventricular, uncalcified mass. After craniotomy a partly solid and cystic mass was resected. Light microscopy examination of the solid part shows a well-differentiated papillary squamous epithelium arranged in anastomosing cords and papillae. Peripheral palisading of cells, "stellate reticulum" and keratoid nodules were not present. No cholesterol clefts or calcifications are seen. The differential diagnosis of this tumor is discussed.

Craniopharyngioma↗
PubMed1996

Brain oedema in patients with intracranial meningioma. Correlation between clinical, radiological, and histological factors and the presence and intensity of oedema.

The authors analysed the correlation between different clinical, radiological, and pathological variables and the presence and intensity of brain oedema associated to intracranial meningioma in 400 consecutive patients studied by computerized tomography (CT). The following factors did not show significant correlation with brain oedema development: the age and sex of the patient, the occurrence of focal deficits, the presence of skull changes (endostosis, exostosis, osteolysis), the occurrence of tumour calcification, the density of the tumour on plain CT scan, the presence of a cystic component, the pathological subtype of meningioma (both conventional and non-conventional), and the presence of histological features of tumour aggressiveness, such as an increased vascularization, high cellularity, high mitotic index, pleomorphism, necrosis, and brain infiltration. Factors showing a statistically significant correlation with the presence and intensity of brain oedema at the bivariate analysis were: the presence of symptoms (p < 0.001), the duration of the clinical history (p < 0.05), the location and size of the tumour (p < 0.001), the type (heterogeneous vs homogeneous), and intensity of tumour contrast enhancement (p < 0.001), the presence of irregular tumour margins (p < 0.001), and the existence of focal low density intratumoural areas (p < 0.001). The multivariate analysis using only clinical parameters showed that the group of variables with the highest power for predicting the presence of brain oedema (concordance level of 76.8%) included: the presence of symptoms, the occurrence of seizures (focal or generalized), the presence of an intracranial hypertension syndrome, and the age of the patient. The multivariate analysis using only anatomico-radiological parameters showed that the model which included the size of the tumour, the intensity of contrast enhancement, the tumour margins, and meningioma location, predicted the presence of brain oedema in 80.8% of the cases. Though the results of the present study do not definitively support any of the major physiopathological theories proposed to explain brain oedema formation in patients with intracranial meningioma, some findings could favour the so-called hydrodynamic theory.

Adolescent↗
PubMed1996

Patient-doctor communication in cross-national perspective. A study in Mexico.

The authors assessed the cross-national replicability previously used to study medical encounters in the United States by adapting them to Mexico. The main research questions focused on information-giving, gender and social class differences in communication, and attention to socioemotional concerns in primary encounters. Sixty-two primary care encounters were audiotaped. Questionnaires were translated into Spanish, then translated back into English. Coding and transcription techniques were taught to Spanish-speaking researchers. Measures of communication were treated as dependent variables and were related by nonparametric statistical analyses to characteristics of physicians, patients, and clinical settings. Doctors in Mexico spent an average of 2.1 minutes (+/- 1.7 standard deviation [SD]), or 16.7% (+/- 10.7 SD) of total interaction time, in information-giving. Mexican doctors asked an average of 27.3 questions per encounter (+/- 18.0 SD), whereas patients asked an average of 1.5 questions (+/- 2.0 SD). Substantial interphysician variability was observed in total time of interaction (Kruskal-Wallis analysis of variance, chi-square = 27.2, P = 0.000), physician time in information giving (chi-square = 16.4, P = 0.022), and physician questions (chi-square = 36.7, P = 0.000). Patient characteristics associated with physician information-giving included male gender (chi-square = 4.1, P = 0.04) and age (Kendall's tau-b = .17, P = 0.05) but not education (tau-b = .08, P = 0.41). Information-giving in public clinics did not differ from that in private practices (chi-square = 0.0, P = 0.91). A bootstrap approach to multiple nonlinear regression permitted additional analysis of physicians', patients', and situational characteristics in explaining measures of patient-doctor communication; this analysis further demonstrated the importance of interphysician variability in communicative behavior. Previous methods for studying patient-doctor communication can be adapted and replicated in a non-English-speaking society. With certain exceptions, findings from Mexico were similar to those obtained in the United States.

Adult↗
PubMed1996

[Evaluation of pulmonary arteries using nuclear magnetic resonance in patients with pulmonary atresia].

OBJECTIVES: Patients with pulmonary atresia and a ventricular septal defect have one outlet vessel; the aorta. The pulmonary arteries may be present or absent, and there is a collateral shunt. Magnetic resonance imaging is used to study this. MATERIAL AND METHODS: We evaluated 10 patients with pulmonary atresia with ventricular septal defect. Five were males and the others were females, ages ranged between 1 day and 25 years, three patients were newborns. We used common planes, but mainly: axial-transverse and coronal, normal and right or left oblique projections. RESULTS: The size of the ventricular septal defect was 1.75 +/- 0.67 cm (0.5-3.2). The pulmonary trunk was absent in 7 patients, it was atretic in 2 and it was present in one. Confluent pulmonary branches were seen in 6 patients (right 0.58 +/- 0.12, left 0.53 +/- 0.19), not confluent in 2 (with only one branch in each case) and absent in the other two. There was collateral shunt flowing from the descending aorta in 7 patients, from the ascending aorta in two and from the aortic in the final case. The ascending aorta was dilated in all cases (diameter 3.04 +/- 1.39), afterwards the relation between the ascending aorta and the descending aorta was 1.87 +/- 0.25. The aortic arch was right sided in 5 patients. CONCLUSIONS: Magnetic resonance imaging is an alternative diagnostic method to angiocardiography. It gives complete information about the size, the position and the connection of the pulmonary arteries. It is also useful to evaluate the aortopulmonary to bronchial shunt.

Adult↗
PubMed1996

[Acquired aortic coarctation after surgical operation of ductus arteriosus in a preterm infant].

The coarctation of the aorta can be acquired or secondary to the surgical correction of congenital anomalies of the great vessels. We report the cases of two newborns operated for patency of the ductus arteriosus (normal aortic arch and a great left-to-right-shunt). During the postoperative period the patients were asymptomatic and the echocardiogram showed no abnormalities. Later, both patients developed coarctation of the aorta. This is the first report of this condition during the neonatal period.

Aortic Coarctation↗
PubMed1996

[Surgical treatment of partial anomalous pulmonary venous drainage].

OBJECTIVES: We studied all patients operated for partial anomalous pulmonary venous drainage and half-time follow-up. MATERIALS AND METHODS: Twenty-eight patients with a mean age of 5 +/- 5 years (5 patients were less than 1 year old). There were sixteen male and twelve female patients. Thirteen patients were symptomatic (47%). The drainage was to the superior vena cava in thirteen cases, to the inferior vena cava in eight cases, to the right atrium in five cases, mixed (to the superior vena cava and to the inferior vena cava) in one case and to the innominate vein in one patient. The diagnosis was made through echocardiography and catheterization in 25 patients, whereas nuclear magnetic resonance was performed in the last five patients. All cases were corrected through medium thoracotomy, except for the single case in which the drainage was to the innominate vein). In 27 patients, the pulmonary veins were guided to the left atrium through an enlarged present atrial septal defect or through a created atrial septal defect. In one case a direct connection was performed from the veins to the left atrium. After the surgical correction, all patients underwent a color-coded Doppler echocardiography study and a nuclear magnetic resonance study was performed in five patients. RESULTS: Twenty-seven patients survived after surgical correction. The patient with a mixed drainage developed an obstruction of the superior vena cava, the pressure gradient was 9 mmHg. He required a second surgical procedure followed with angioplasty on two occasions during a six month period. Two patients showed an ectopic atrial rhythm at some late time. The patient who died was one month old and had an associated pulmonary parenchymal sequestration. CONCLUSION: Partial anomalous venous connection is a congenital heart disease which has an easy surgical correction. Complications may arise after the surgical correction, among them obstruction of the superior vena cava and arrythmias are most frequently found. Obstruction is present when 50% of the caval area is occupied by the patch. The arrythmias occur following all surgical techniques. In order to decrease the arrythmias it is necessary to perform a good hemosthasis at the site of the patch, to leave the sinus node free of compression and to perform the atrial incision at the posterior wall. The diagnosis and the follow-up can be performed with non-invasive procedures.

Adolescent↗
PubMed1996

[Histo-morphometry of bone mass and cellularity using image analysis: characterization of infiltration patterns in CLL].

PURPOSE: The aim of this study was to investigate a possible influence of lymphocytic infiltration in Chronic Lymphocytic Leukemia (CLL) on bone mass, according to the infiltration patterns. MATERIAL AND METHODS: We have studied histological preparations from decalcified and paraffin included bone biopsies and used a histomorphometric study through a mixed (interactive-automatic) image analysis, in order to quantify bone trabecular (BT/TV) and cellular volume (CV). Preparations were visualized via a 2.5 objective; a video camera was adapted and connected to a computer with analogical-digital converter incorporated. After the image was captured, a binarization was made by trabecular and medullary spaces segmentation; automatically, we calculated trabecular area (TA) and cellular area (CA). Expressions indicated above were used to calculate BV/TV and CV, expressed in percentage: BV/TV (%) = [TA/(TA + CA)] x 100, and CV (%) = [CA/(TA + CA)] x 100. RESULTS: 92 normal biopsies and 79 CLL biopsies were studied (Nodular 12, Diffuse 22, Interstitial 23, Mixed 22). BT/TV in normal subjects age over 45, was 18.40%; it was lower in CLL subjects, 17.25%. CV was 33.62% in normal cases and significantly higher in CLL with 42.95%. According to the infiltration patterns, Nodular pattern showed similar value to normal biopsies, versus Diffuse pattern with BT/TV of 16.19% and CV of 51.49%. Significantly, a high CV value was accompanied of a low B/TV value, in normal and CLL subjects. CONCLUSIONS: We analyzed histomorphometrically trabecular volume as expression of bone mass in undecalcified biopsies. CLL infiltration tended to show a lower trabecular volume. Diffuse pattern presented the higher cellular infiltration and bone mass destruction.

Aged↗