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Biomedical subjects

A Cabrera

Publications and source records attributed to A Cabrera.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1995

Double-chambered right ventricle.

UNLABELLED: Between May 1974 and December 1993, 37 patients (0.75%) with a double-chambered right ventricle underwent surgical repair. The patients ranged in age from 11 months to 12 years (mean 4 +/- 1.1 years). Cardiac catheterization was performed in 36 patients. The proximal right chamber pressure was 118 +/- 10 mmHg and the mean ventricular gradient pressure was 75 +/- 10 mmHg. A ventricular septal defect was present in 36 cases and fixed subaortic stenosis in eight. Longitudinal right ventriculotomy, group I, was performed in 19 patients (51.3%): 11 had a perimembranous ventricular septal defect and eight an infundibular ventricular septal defect. Combined pulmonary arteriotomy and right atriotomy, group II, was performed in 18 patients (48.7%): 17 patients had a perimembranous ventricular septal defect. The ventricular septal defect was closed using a double velour patch in 26 patients, continuous suture in four and a Gore-Tex patch in six. In the ventriculotomy group one patient died shortly after the operation (following pulmonary complication), and ten patients required inotropic support. Two patients developed patch dehiscence and underwent reoperation. There were no complications in group II patients who underwent right atriotomy. Associated cardiac anomalies were corrected in all patients. Follow-up of 6.5 +/- 3.1 years after operation showed that 36 patients were alive and asymptomatic. CONCLUSION: the transatrial approach with pulmonary arteriotomy is an appropriate and effective double-chambered right ventricle correction even if it is associated with a perimembranous ventricular septal defect.

Child↗
PubMed1995

[Unilateral agenesis of the pulmonary branch. Its diagnosis by color echo-Doppler and nuclear magnetic resonance].

We present two symptomatic patients of five and six months old with unilateral agenesis of main pulmonary branch (right and left) without associated anomalies. The diagnostic was made with magnetic resonance imaging and two-dimensional echocardiographic with Doppler color flow. We think that the magnetic resonance, must be used with priority in this pathology for being a non invasive diagnostic method, that is able to diagnostic the basic cardiopathy and the intracardiac and extracardiac associated anomalies. His association with the Doppler-echocardiography allow to ignore the arteriography upon to get a accurate diagnostic.

Abnormalities, Multiple↗
PubMed1995

Subcutaneous Nocardia asteroides abscess in a bone marrow transplant recipient.

We describe a case of cutaneous Nocardia asteroides infection in a 13-year-old Venezuelan boy with aplastic anemia, following allogeneic BMT. He was receiving immunosuppressive therapy with corticosteroids for GVHD and trimethoprim/sulfamethoxazole (TMP/SMX) for prophylaxis against Pneumocystis carinii pneumonia (PCP). He was not neutropenic and gave no history of cutaneous inoculation or trauma. He developed an abscess on the plantar surface of his right big toe from which Nocardia asteroides was isolated. He was successfully treated with a combination of TMP/SMX and minocycline. Despite prolonged immunosuppressive therapy for GVHD, the infection responded and did not recur. TMP/SMX prophylaxis for PCP in BMT recipients with GVHD does not always prevent nocardial infection but may prevent or delay the development of dissemination.

Abscess↗
PubMed1995

Dietary factors in epidemic neuropathy on the Isle of Youth, Cuba.

An epidemic neuropathy that broke out in Cuba in late 1991 has exhibited clinical manifestations similar to those of other polyneuropathies of nutritional origin. To investigate its possible association with diet, a study was conducted on the Isle of Youth in 1993, at the start of an outbreak there. Thirty-four subjects with cases and 65 controls were interviewed regarding their diets, measured anthropometrically, and evaluated. As a whole, the subjects with cases demonstrated greater weight loss before the onset of disease, lower body mass indexes (BMI), lower percentages of body fat, and more deficient diets than the control subjects. Analysis of individual variables found associations between occurrence of the disease and the following: weight loss, low BMI, a broad range of specific dietary deficiencies, a sugar intake exceeding 15% of total caloric intake, alcohol consumption, and smoking. Also, protective associations were found between absence of the disease and regular consumption of certain foods at or above specified levels. Multivariate analysis indicated that while smoking and alcohol consumption reinforced the effects of the dietary deficiencies, they did not account for occurrence of the disease by themselves. Overall, the results indicate that diets which are deficient in caloric energy, protein, fat, and the micronutrients included in the study, and which reflect an imbalance resulting from a relative excess of sugar, with consequent effects on body weight, are strongly associated with, and causally related to, the occurrence of epidemic neuropathy in Cuba.

Adult↗