PubMed Health⌕ Search

Biomedical subjects

A L Fernández

Publications and source records attributed to A L Fernández.

18 recordsLinked to original sources
PubMed2006

High thoracic epidural blockade increases myocardial oxygen availability in coronary surgery patients.

BACKGROUND: High thoracic epidural techniques are increasingly being used in patients scheduled for cardiothoracic surgery, including coronary artery bypass grafting. In the present study, we evaluated the acute effects of the epidural blockade on myocardial oxygen availability by means of tissue oxygen pressure monitoring in patients submitted for surgical revascularization. METHODS: Fifty adult patients were included in a prospective, randomized, double-blind study. After placement of an epidural catheter in thoracic space T1-T2, and under general anesthesia, 5-10 ml of either normal saline or 0.3% ropivacaine was injected through the epidural catheter. Hemodynamic parameters and the intramyocardial oxygen partial pressure were recorded before and 20 min after the epidural injection. RESULTS: There were no demographic or hemodynamic differences between the groups before intervention. A significant increase in intramyocardial partial oxygen pressure was observed in the ropivacaine group (14.6 mmHg vs. 25.1 mmHg, P < 0.0005). CONCLUSION: High thoracic epidural blockade with 5-10 ml of 0.3% ropivacaine increases myocardial oxygen availability in coronary diseased patients prior to surgical revascularization without deleterious hemodynamic disturbances.

Aged↗
PubMed2001

Study of the polymerization of anthracene oil with AlCl3 by chromatography and related techniques.

The structure and composition of products from the reaction of anthracene oil with anhydrous AlCl3 have been examined. Size-exclusion chromatography has been carried out using a column with polystyrene-polydivinylbenzene as stationary phase, 1-methyl-2-pyrrolidinone at 80 degrees C as eluent and variable-wavelength UV-absorption detection. This system provides a chromatogram of the sample with several peaks. Molecular masses corresponding to these peaks were estimated using a calibration curve obtained with polycyclic aromatic hydrocarbon standards, ranging from 92 to 532 u. The most abundant compounds of the substrate were dimers and trimers of the main anthracene oil components. These results are corroborated on a qualitative level by synchronous UV-fluorescence spectra.

Aluminum Chloride↗
PubMed2001

Effect of storage of plasma and serum on enzymatic determination of non-esterified fatty acids.

Many contradictory results have been published on the stability of total non-esterified fatty acids in blood, plasma and serum under different storage conditions. The present study was undertaken to investigate the stability of non-esterified fatty acids, measured with an enzymatic method, in samples of EDTA-treated plasma and serum under different temperature conditions. We conclude that EDTA-treated plasma and serum can both be used for analysis. Specific reference values should be established depending on the type of sample chosen. Samples that cannot be analysed immediately can be stored at -20 degrees C for at least 14 days without significant changes in the concentration of total non-esterified fatty acids. None of the other storage conditions and periods studied are suitable for the measurement of non-esterified fatty acid concentration.

Adult↗
PubMed1999

Monitoring the synthesis of new pitches from coal tar and its fractions by chromatography and related techniques.

The aim of this paper is to study the applications of chromatography and related techniques in the transformation of coal-derived products into pitches for specific uses. Anthracene oil, tar and pitch were thermally treated in the presence of air (and sulfur in the case of anthracene oil) in order to cause the polymerization/condensation of their components. The evolution of the components of the parent materials during the treatments was monitored by gas chromatography-mass spectrometry, gas chromatography-atomic emission detection, probe mass spectrometry and size-exclusion chromatography. From the results obtained, possible mechanisms for the transformation of coal-derived products into new pitches were established.

Air↗
PubMed1997

Heart transplantation for Finnish type familial systemic amyloidosis.

A patient with Finnish type familial systemic amyloidosis associated with lattice corneal dystrophy (Meretoja's syndrome) underwent heart transplantation with uneventful postoperative course. Five years later the patient has mild chronic renal failure, normal cardiac allograft function and almost total bilateral blindness.

Amyloidosis↗
PubMed1997

Spontaneous and isolated dissection of the common iliac artery.

A patient with isolated dissection of the common iliac artery is presented. A 56-year-old man was admitted because of sudden intermittent claudication of the left lower limb. Angiography showed a left popliteal artery interruption associated with an asymptomatic dissection of the right common iliac artery. The patient was treated with a left femoropopliteal bypass and a right aortofemoral bypass. The etiology of primary dissections of peripheral arteries is discussed.

Aortic Dissection↗
PubMed1996

Diverticulum of the left ventricle associated with subvalvar aortic stenosis.

Diverticula of the left ventricle are rare and only a few cases have been documented in adults. They may be asymptomatic or may present with embolization, pain, endocarditis, or sudden death. We report the case of a 34-year-old woman who presented a cardiac arrest with ventricular fibrillation which required electrical cardioversion. She was found to have a left ventricular diverticulum associated with a subvalvar aortic stenosis. The diverticulum arose from the apex with a narrow connection to the ventricular cavity. A subvalvar fibrous ridge stenosis with a systolic pressure gradient of 115 mmHg was observed. Coronary angiography revealed normal coronary arteries. The diverticulum and the subvalvar fibrous ridge were resected. Histologic examination of the diverticulum wall demonstrated the presence of the three normal layers with marked muscle cell hypertrophy, atypical plexiform structure and fibrous endocardium. The pathophysioloy of diverticula associated with subvalvar aortic stenosis are discussed.

Adult↗
PubMed1996

Primary graft failure after heart transplantation. Successful recovery with pneumatic biventricular assistance.

A 41-year-old male underwent orthotopic heart transplantation complicated by intraoperative acute allograft failure. The patient required immediate placement of a pneumatic biventricular assist device which was kept for 49 days until graft recovery resulted in successful explantation of the device. The patient was discharged from hospital on postoperative day 112. Management of primary cardiac allograft failure with mechanical ventricular assistance is discussed.

Adult↗
PubMed1995

Skin cancer in heart transplant recipients.

BACKGROUND: The frequency of skin cancer in organ transplant recipients is high, up to 15%. OBJECTIVE: Our purpose was to determine the incidence of skin cancer in patients who underwent immunosuppression after heart transplantation and to determine the factors important in the appearance of skin cancer. METHODS: We studied the frequency of skin cancer in 92 of 111 patients after they underwent heart transplantation between January 1984 and December 1993. RESULTS: At least one cutaneous neoplasm (squamous cell carcinoma and/or basal cell carcinoma) developed in 14 patients (15.2%). The basal cell carcinoma to squamous cell carcinoma ratio was 1:1.5. The skin cancer appeared an average of 31.5 months after transplantation; the average was 36 months for squamous cell carcinoma and 25.3 months for basal cell carcinoma. Cumulative risk rose from 4.3% at 1 year up to 43.8% at 7 years after transplantation. The overall incidence of both types of skin cancer was 45.3 per 1000 posttransplant person-years, with an incidence of 25.8 for basal cell carcinoma and 29.1 for squamous cell carcinoma. Most skin cancers developed between 2 and 3 years after transplantation. All patients were exposed to a significant amount of ultraviolet radiation and had skin type II or III. We did not find a significant association between skin cancer and haplotype HLA-A3, HLA-A11, HLA-DR, and the number of mismatches for HLA-B. CONCLUSION: We found an increased progressive cumulative incidence of skin cancer in heart transplant recipients for two reasons: (1) immunosuppression and increased exposure to ultraviolet radiation in some patients, and (2) the skin type of certain patients. We emphasize the need for photoprotection in this group of patients and regular skin cancer screening examinations.

Adult↗
PubMed1995

[Lymphoproliferative disease and cancer in the transplant patient].

According to the Spanish Cardiac Transplantation Registry, malignant neoplasm remain the fifth leading cause of death in heart transplant recipients. Skin cancers are the most common malignancies and they are frequently associated to solar keratosis, warts and keratoacanthoma. Geographic areas are high cumulative ultraviolet exposure have a greater incidence of skin cancer. Skin tumors are often located in chronically sun-exposed areas of the body. Lymphoproliferative disorders are the second most frequent malignant neoplasm after heart transplantation. Incidence of lymphoma is 350 times greater in heart transplant recipients than in the general population. B-cell tumors are the most common histologic type and it is associated with infection by the Epstein-Barr virus. T-cell tumors account for a 12% of all lymphoproliferative diseases and are not related to viral infections. Kaposi's sarcoma is the thirth commonest neoplasm in heart transplant recipients. Other malignat tumors are: uterine cervix, vulva, scrotum, colon, stomach, kidney and biliary tract. Prevention of neoplasm in heart transplant recipients include a decrease of immunosuppression and the avoidance of multiple immunosuppressive drug association. Some cases of neoplasm regression have been described when immunosuppressive therapy is decreased.

Heart Neoplasms↗
PubMedDate not supplied

Different antiganglioside antibody pattern between relapsing-remitting and progressive multiple sclerosis.

INTRODUCTION: Multiple sclerosis (MS) is an autoimmune disorder, but an unique antigen has not been found. Antiganglioside antibodies (AGA) have been reported in MS, nevertheless, a clinical significance of AGA in MS has not been established. The aims of this study were to study AGA in sera of MS patients and to investigate relationships between AGA and clinical course of MS. MATERIAL AND METHODS: 42 patients with MS who fulfilled the criteria of clinically definite disease (59% RRMS, 21% SPMS, 20% PPMS), 89 patients with systemic lupus erythematosus and 36 healthy controls were studied. A modification of previously described ELISA techniques was used to estimate serum IgG and IgM anti-GM1, asialoGM1 and anti-GD1a antibodies. RESULTS: 47.6% of the patients showed AGA reactivity. Anti-GM1 was found in 38% of MS patients, anti-asialoGM1 in 23.8% and anti-GD1a in 33.3%. IgG was the isotype more commonly found. A correlation between presence of AGA and progressive disease and between anti-GD1a and PPMS was found. CONCLUSIONS: The presence of AGA in MS patients is elevated. In contrast with the results of others authors, a strong correlation between AGA and progressive disease is showed in our study.

Adult↗
PubMedDate not supplied

[Right heart support during coronary artery bypass grafting without cardiopulmonary bypass].

BACKGROUND AND OBJECTIVES: Exposure of lateral and inferior coronary vessels during off-pump coronary artery bypass grafting may cause significant hemodynamic compromise due to right ventricular compression when tilting the heart. Some new right ventricular assistance devices have been developed in order to avoid this problem but only a few series have been published. A preliminary experience with a right heart circulatory support system is reported. METHODS: A total of eight patients underwent off-pump coronary artery bypass grafting using a right heart support device. Technical procedure and clinical outcome are analyzed. RESULTS: The right heart circulatory support device insertion and management were performed without any complication. A total of 21 distal coronary anastomoses were completed. They were located on the anterior descending artery(8), circumflex branches(6), diagonal branches(2), posterior descending artery(3) and right coronary artery(2). The right ventricular support device delivered flow at a medium rate of 2.2 L/min, providing hemodynamic stability when tilting the heart and exposing the coronary arteries. CONCLUSIONS: The use of right heart support devices is a simple and low risk procedure which may facilitate surgical anastomoses on lateral and inferior epicardial vessels during off-pump coronary artery surgery.

Aged↗