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F Valdés

Publications and source records attributed to F Valdés.

At least 37 records · Page 2Linked to original sources
PubMed2001

Role of exercise and ascorbate on plasma antioxidant capacity in thoroughbred race horses.

During exercise, the oxygen consumption and the production of free radicals increase and can lead to oxidative stress with a deleterious effect on cellular structures involved in physical activity. To evaluate the oxidative stress produced by exercise and the role of ascorbate as an antioxidant, venous blood samples were obtained from 44 thoroughbred racehorses, before and after a 1000+/-200-m race at maximum velocity. Fourteen of these horses were treated intravenously with 5 g of ascorbate before running. Antioxidant capacity (PAOC), endogenous and exogenous ascorbate concentration, total antioxidant reactivity (TAR), urate concentration, creatine kinase activity, protein concentration and thiobarbiturate reactive substances (TBAR) as oxidative stress indicators were measured in the plasma of some of these horses. PAOC, TAR and TBAR increased after the race, while plasma ascorbate and urate concentrations remained unchanged. Total plasma protein (TPP) concentrations increased in line with antioxidant capacity. As predicted, both the plasma ascorbate concentration and PAOC increased immediately after ascorbate administration, but was not modified after the race, such as TBAR. However, in both groups plasma creatine kinase activity increased after the race. These results would suggest that the administration of ascorbate could nullify the oxidative stress produced by exercise in thoroughbred racehorses, but could not prevent muscular damage.

Animals↗
PubMed2001

Prospective comparison of clinical and echocardiographic diagnosis of rheumatic carditis: long term follow up of patients with subclinical disease.

OBJECTIVE: To determine the frequency of occurrence and long term evolution of subclinical carditis in patients with acute rheumatic fever. DESIGN: Valvar incompetence was detected by clinical examination and Doppler echocardiographic imaging during the acute and quiescent phases of rheumatic fever. Patients were followed prospectively and submitted to repeat examinations at one and five years after the acute attack. Persistence of acute mitral and aortic lesions detected solely by echocardiography (subclinical disease) was compared with that of disease detected by clinical examination as well (thereby fulfilling the latest 1992 Jones criteria for rheumatic carditis). SETTING: Three general hospitals with a university affiliation in Chile. PATIENTS: 35 consecutive patients fulfilling the revised Jones criteria for rheumatic fever. Clinical and echocardiographic examination was repeated in 32 patients after one year and in 17 after five years. Ten patients had subclinical carditis on admission, six of whom were followed for five years. MAIN OUTCOME MEASURES: Auscultatory and echocardiographic evidence of mitral or aortic regurgitation during the acute attack or at follow up. RESULTS: Mitral or aortic regurgitation was detected by Doppler echocardiographic imaging in 25/35 rheumatic fever patients as opposed to 5/35 by clinical examination (p = 0.03). Doppler echocardiography revealed acute valvar lesions in 10 of 20 rheumatic fever patients who had no auscultatory evidence of rheumatic carditis (subclinical carditis). Three of these subclinical lesions and three of the clinical or auscultatory lesions detected on admission were still present after five years of follow up, emphasising that subclinical lesions are not necessarily transient. CONCLUSIONS: Doppler echocardiographic imaging improves the detection of rheumatic carditis. Subclinical valve lesions, detected only by Doppler imaging, can persist. Echocardiographic findings should be accepted as a major criterion for the diagnosis of rheumatic fever.

Adolescent↗
PubMed2001

[Endovascular therapy of superior vena cava syndrome: clinical case].

The treatment of superior vena cava syndrome is usually oriented to the underlying cause, that can be too slow in emergency cases. We report a 49 years old woman with a multiple myeloma that was admitted due to a superior vena cava syndrome caused by a central venous catheter used for chemotherapy for 20 weeks. She was successfully treated with thrombolysis, angioplasty and stent placement. The patient died 7 months later due to the underlying disease. Long term catheters are the responsible for 20 to 30% of superior vena cava syndromes. Endovascular treatment of the syndrome is successful in 60 to 100% of cases with a symptomatic relapse in 4 to 45% of patients.

Angioplasty, Balloon↗
PubMed2001

[Ruptured thoracic aorta aneurysm: endovascular treatment].

In 1991, a technique to exclude aortic aneurysms from circulation inserting an endoluminal graft through the femoral artery, was described. This procedure, usually used for elective abdominal aneurysms, can also be used in the thoracic aorta. We report a 41 years old male with a Marfan syndrome, presenting with a descending aorta aneurysm that ruptured to the mediastinum and pleural cavity. He was compensated hemodynamically and an endovascular stent-graft was deployed at the ruptured zone, through the femoral artery. The postoperative evolution of the patient was uneventful. This technique will allow a less invasive treatment of ruptured aortic aneurysms.

Adult↗
PubMed2000

[Carotid endarterectomy under regional anesthesia: initial experience].

BACKGROUND: Endarterectomy is the treatment of choice for internal carotid artery critical stenosis. Some authors have proposed that the use of regional anesthesia has advantages over general anesthesia. AIM: To report our initial experience with carotid endarterectomy under regional anesthesia. PATIENTS AND METHODS: Between 1998 and 1999, patients with critical carotid artery stenosis, asymptomatic or with transient and recovered symptoms, were selected. A C2, C3, C4 root deep cervical block and superficial block was performed, using a mixture of lidocaine and bupivacaine. A carotid endarterectomy with patch and without routine shunt insertion, with standard and neurological monitoring, was performed. RESULTS: During the study period, 94 carotid endarterectomies were done, 22 under regional anesthesia in 21 patients (12 male, age range 58-90 years old). Ninety five percent had hypertension, 52% smoked and 38% had renal dysfunction. One patient was converted to general anesthesia. Seventeen patients were discharged within 48 hours of the procedure and the rest, within 72 hours. There was no mortality or complications. CONCLUSIONS: Endarterectomy under regional anesthesia is less invasive, has excellent results and is well accepted by patients.

Aged↗
PubMed1999

Early proteinuria in renal transplant recipients treated with cyclosporin.

PURPOSE: To establish the risk profile for the development of proteinuria in the first months after renal transplantation and to disclose the prognostic significance of this finding. DESIGN: We conducted an observational historic cohort study. SETTING: We conducted the study in a tertiary care hospital renal transplantation unit covering a potential population of approximately 2 million. We made extensive use of suboptimal donors. POPULATION: In our unit, 560 cadaveric renal transplants were performed between January 1988 and June 1997, under Cyclosporine immunosuppression, with a minimum follow up of 1 year. METHOD: The risk profile analysis explored early clinical factors reported to be related to the late course of renal transplantation. The study of the prognostic significance of proteinuria included survival analysis and correlation with late markers of graft dysfunction, taking into consideration the intensity and persistence of early proteinuria. A multivariate approach was used in all cases. RESULTS: Early proteinuria was strongly associated with delayed graft function (odds ratio [OR] 1.03/day of dialysis), acute rejection (OR 1.7 for steroid-sensitive and 6.2 for steroid-resistant rejection), renal transplant to a hypersensitized recipient (OR 2.5), and pediatric (<5 years)(OR 4.1) or older (>60 years)(OR 3.0) donors. The predictive model for persistency of proteinuria was very similar, whereas transient proteinuria could not be adequately modeled. Increasing intensity of proteinuria was strongly associated with poor patient and graft survival. Persistent, but not transient, proteinuria supported this relationship. CONCLUSIONS: Proteinuria appearing early after renal transplantation is strongly associated with delayed graft function, acute rejection, and the use of pediatric or older donors. Whatever its background, proteinuria is a strong predictor of poor patient and graft survival. This effect is directly related to the intensity and persistence of the disorder.

Adolescent↗
PubMed1999

Early immunologic and nonimmunologic predictors of arterial hypertension after renal transplantation.

We followed up a cohort of 680 renal transplant recipients receiving cyclosporine (CsA) immunosuppression with the aim of establishing an early-risk profile for early and late hypertension (HT) after renal transplantation (RTx), specifically comparing the predictive role of immunologic and nonimmunologic markers of graft prognosis. HT was defined as the need for antihypertensive drugs. The prevalence of HT was 65% at the time of RTx, increased to a peak of 78% at the end of the first year, and stabilized between 71% and 73% thereafter. Multivariate analysis identified HT at the time of RTx, basal renal disease, and grafting the right kidney as independent predictors of HT 3 months after RTx. The risk profile for HT 12 months after RTx included HT present at RTx, grafting the right kidney, markers of early ischemia-reperfusion injury (delayed graft function, cold and warm ischemia), and transplant from an elderly or female donor. Polytransfusion before RTx was associated with a decreased risk for HT, but retransplantation, increased reactivity against the lymphocyte panel, poor HLA compatibility, and early acute rejection did not portend an increased risk for the complication under study. The CsA schedule (dose, trough levels) correlated poorly with the blood pressure status of the patients, but simultaneous graft function was independently associated with late HT. In conclusion, the early predictive profile for HT after RTx includes, preferentially, nonimmunologic markers of graft prognosis. Hyperfiltration damage may be a significant pathogenic mechanism for this complication of RTx.

Adolescent↗
PubMed1999

[Popliteal vein aneurysm].

The popliteal vein aneurysm is a rare condition that can lead to local symptoms, thrombosis and pulmonary embolism. We report the case of a 67 years old, otherwise healthy white male, who presented to us with localised swelling and pain in the left popliteal fossa. Duplex ultrasound and venography were obtained, confirming the diagnosis of popliteal vein aneurysm. The patient underwent tangential aneurysmectomy and lateral venorrhaphy, recovery was uneventful remaining asymptomatic. The reconstruction was demonstrated patent on a duplex scan. The popliteal vein aneurysm is a potentially fatal condition for which surgical treatment is recommended.

Aged↗
PubMed1999

[Ilio femoral thrombosis: an infrequent complication of an aortic and iliac aneurysm. Report of two cases].

Death due to rupture of and abdominal aortic or iliac aneurysm, is their most frequent complication. We report two male patients, both over seventy years old, who presented with unexplained unilateral ilio-femoral deep vein thrombosis. During diagnostic work up an aortic and iliac aneurysm, compressing the deep venous system with secondary thrombosis, was found. In both patients a prophylactic inferior vena caval filter was inserted and standard elective surgery was then performed. No perioperative complications occurred and both patients remain asymptomatic during follow up. Deep vein thrombosis due to compression by an abdominal aortic and iliac aneurysm is infrequent. It must be ruled out together with intrabdominal cancer, in the elderly patient presenting with unexplained deep vein thrombosis.

Aged↗
PubMed1998

The prognostic significance of acute renal failure after renal transplantation in patients treated with cyclosporin.

We studied 733 cadaveric renal transplant patients (747 transplants) under cyclosporin immunosuppression, to: (i) establish the risk profile for acute renal failure (ARF) after renal transplantation in a unit using many sub-optimal donors; (ii) assess the long-term prognostic relevance of ARF; and (iii) explore the synergistic prognostic significance of delayed graft function and acute rejection during the early post-transplant period. Transplanting from a non-heart-beating or elderly donor, protracted cold ischaemia, haemodialysis immediately before transplant surgery, poor HLA matching, and grafting to a hypersensitized recipient without residual renal function, all independently predicted delayed graft function. This delay had no detrimental effect on patient or graft survival, but prolonged ARF was associated with increased mortality from infection. Late markers of graft dysfunction (poor graft function, proteinuria, hypertension) were highly prevalent among grafts affected by ARF, specially in prolonged ARF. Delayed graft function and early acute rejection showed a definite, albeit not strong, additive impact on late graft survival, and also on the prevalence of late markers of graft dysfunction.

Acute Kidney Injury↗
PubMed1998

[Inferior vena cava filters. Indications and results in 111 patients].

BACKGROUND: Anticoagulation is the treatment of choice for deep vein thrombosis and pulmonary embolism. Occasionally this treatment is contraindicated or fails to prevent pulmonary embolism. In these patients, inferior cava vein interruption is indicated and filter insertion is the procedure commonly performed. AIM: To report the results of inferior cava vein filter insertions in 111 patients. PATIENTS AND METHODS: A retrospective review of patients in whom inferior cava vein filters were inserted was performed. RESULTS: During the period 1983-1997, filters were inserted in 111 patients (56 female) aged 15 to 93 years old. Indications were pulmonary embolism with contraindication or failure of anticoagulation therapy or poor respiratory function (58 patients), deep vein thrombosis and contraindication for anticoagulation (32 patients) and other indications in 20 patients. In 47 patients, treated before 1993, the insertion required a cut-down. Since then, a percutaneous approach was used in the remaining 64 cases. Three insertion attempts failed, all using cut-down. One of these patients died due to a massive pulmonary embolism. In 88% of the patients the jugular vein was the access site and in 10 patients, the filter was deliberately deployed above the renal veins. There was no mortality or complications. Patients were followed during a maximal period of 147 months and 27 died of unrelated disorders. Survival at 5 and 10 years was 63 and 47% respectively. Symptomatic inferior cava vein obstruction was detected in 5 patients during the follow up period. CONCLUSIONS: Inferior cava vein filter insertion is a safe measure to prevent pulmonary embolism and its consequences.

Adolescent↗
PubMed1997

[Lower extremity salvage in diabetics: microsurgical muscle transplantation with and without previous vascular reconstruction].

Soft tissues wounds with or without bony involvement are a common problem and a cause of limb loss in diabetics. Usually local care, antibiotics, minor debridement and skin grafting are enough for successful handling of these lesions. When there is associated limb ischemia, revascularization is indicated. In patients with large ulcers, proximal bony involvement and tendon exposure, the incidence of primary amputation rises, frequently being considered the only alternative. Two cases of diabetic patients with indication of primary amputation of a lower limb for large infected ulcers are reported. A microvascularized muscle transplant was used to cover large defects of soft tissue, tendons and infected bone. One patient presented also critical ischaemia of the limb, requiring iliac angioplasty and a femoro-distal by-pass with in situ greater saphenous vein previous to the muscle graft. Both patients had no postoperative complications, being able to walk two months after the operation with their useful limb. Microvascularized muscle transplant with or without revascularization is a very useful alternative to amputation in the management of complex wounds of selected diabetic patients.

Adult↗
PubMed1997

[Abdominal aortic aneurysm: course of morbimortality of elective surgery in 20 years].

Abdominal aortic aneurysms (AAA) usually undergo progressive dilatation and eventually may rupture, complication that carries a high mortality rate. If certain clinical conditions, like operative risk and aortic diameter are met, all patients should be considered for surgical repair. Analysis of our results with the surgical treatment of asymptomatic AAA prompted this study. Out of 479 consecutive patients operated because of AAA between 1976 and 1995, 378 (79%) were electively treated. Two decades: 1976-85 (101 patients) and 1986-95 (277 patients) were compared as far as associated medical conditions, surgical procedures, complications and mortality rate. There was no difference in age, sex, risk factors and aortic diameter. During the second decade we favoured the use of aortic tube grafts (53% vs 25%, p < 0.01) and epidural anesthesia (94% vs 35%, p < 0.01). During the last decade only 53.3% of the patients received blood transfusion, compared to 95.3% during the first period (p < 0.001). Operative mortality decreased from 5.94% to 0.72% (p < 0.05). Postoperative hospital stay diminished from 11.2 +/- 8.2 to 9.6 +/- 6.3 days (p < 0.05). These results compare favourably with those reported from other academic centers and support our therapeutic approach. Our contemporary surgical results serve as a reference for future clinical evaluation of endovascular procedures currently under investigation.

Aged↗