Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
Methods Mol Biol ; 2631: 53-101, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36995664

RESUMO

Genetically engineered mice are used as avatars to understand mammalian gene function and develop therapies for human disease. During genetic modification, unintended changes can occur, and these changes may result in misassigned gene-phenotype relationships leading to incorrect or incomplete experimental interpretations. The types of unintended changes that may occur depend on the allele type being made and the genetic engineering approach used. Here we broadly categorize allele types as deletions, insertions, base changes, and transgenes derived from engineered embryonic stem (ES) cells or edited mouse embryos. However, the methods we describe can be adapted to other allele types and engineering strategies. We describe the sources and consequ ences of common unintended changes and best practices for detecting both intended and unintended changes by screening and genetic and molecular quality control (QC) of chimeras, founders, and their progeny. Employing these practices, along with careful allele design and good colony management, will increase the chance that investigations using genetically engineered mice will produce high-quality reproducible results, to enable a robust understanding of gene function, human disease etiology, and therapeutic development.


Assuntos
Edição de Genes , Engenharia Genética , Camundongos , Animais , Humanos , Edição de Genes/métodos , Células-Tronco Embrionárias , Transgenes , Controle de Qualidade , Sistemas CRISPR-Cas , Mamíferos/genética
2.
Commun Biol ; 6(1): 626, 2023 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-37301944

RESUMO

Genome editing with CRISPR-associated (Cas) proteins holds exceptional promise for "correcting" variants causing genetic disease. To realize this promise, off-target genomic changes cannot occur during the editing process. Here, we use whole genome sequencing to compare the genomes of 50 Cas9-edited founder mice to 28 untreated control mice to assess the occurrence of S. pyogenes Cas9-induced off-target mutagenesis. Computational analysis of whole-genome sequencing data detects 26 unique sequence variants at 23 predicted off-target sites for 18/163 guides used. While computationally detected variants are identified in 30% (15/50) of Cas9 gene-edited founder animals, only 38% (10/26) of the variants in 8/15 founders validate by Sanger sequencing. In vitro assays for Cas9 off-target activity identify only two unpredicted off-target sites present in genome sequencing data. In total, only 4.9% (8/163) of guides tested have detectable off-target activity, a rate of 0.2 Cas9 off-target mutations per founder analyzed. In comparison, we observe ~1,100 unique variants in each mouse regardless of genome exposure to Cas9 indicating off-target variants comprise a small fraction of genetic heterogeneity in Cas9-edited mice. These findings will inform future design and use of Cas9-edited animal models as well as provide context for evaluating off-target potential in genetically diverse patient populations.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Camundongos , Animais , Genoma , Mutação , Mutagênese
3.
J Endocrinol Invest ; 30(6): 525-8, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17646730

RESUMO

Cushing's Syndrome (CS) may sometimes lead to dilated cardiomyopathy, even though this condition can be partially or completely reversed after treatment. In this article we report the case of a 28-yr-old woman with CS secondary to adrenal adenoma who exhibited congestive heart failure as an initial symptom. Two weeks before being admitted to our hospital, the patient started complaining of shortness of breath, orthopnea, paroxysmal nocturnal dyspnea and generalized edema. A physical examination did not reveal signs of hypercortisolism. Chest auscultation revealed bilateral diffused crepitation; blood pressure was 180/120 mmHg with heart rate of 90 beats/min. A chest X-ray showed a cardiac shade enlargement due to congestive heart failure. Transthoracic echocardiography demonstrated a dilated left ventricle and an impaired left ventricular systolic function. The patient's urinary cortisol excretion was elevated and circadian rhythm of cortisol was absent. ACTH level was low. In addition, plasma cortisol failed to decrease after administration of dexamethasone. An abdominal magnetic resonance imaging scan showed a 7-cm right adrenal mass. The patient was administered oxygen, spironolactone, ACE-inhibitor and the signs and symptoms of heart failure gradually improved. A laparoscopic right adrenalectomy was performed and pathological examination of the gland showed a benign adrenocortical adenoma. After the adrenalectomy the patient was started on hydrocortisone therapy and 5 months later the wall thickness of the left ventricle was within normal range and the patient's blood pressure was 130/80 mmHg. In conclusion we report the case of heart failure as the main clinical symptom in CS secondary to adrenal adenoma.


Assuntos
Adenoma Adrenocortical/complicações , Síndrome de Cushing , Insuficiência Cardíaca/etiologia , Adenoma Adrenocortical/diagnóstico , Adenoma Adrenocortical/patologia , Adenoma Adrenocortical/cirurgia , Adulto , Síndrome de Cushing/complicações , Síndrome de Cushing/diagnóstico , Síndrome de Cushing/etiologia , Síndrome de Cushing/cirurgia , Ecocardiografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino
4.
Handchir Mikrochir Plast Chir ; 39(1): 73-7, 2007 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-17402144

RESUMO

BACKGROUND: Based on the fact that not every extra-articular distal radius fracture is stable, we asked ourselves whether there would be a place for other methods for stable fracture management besides on the one hand the plaster cast or pin osteosynthesis, respectively, external fixateur and, on the other hand, the traditional plate fixation (from a palmar or dorsal direction). PATIENTS AND METHODS: In this paper, we report our first experience with a novel plate that has been in use in Europe since April 2005. It is a fixed-angle, intrafocal nail plate. We started using it in April 2005 and up to October 31, 2006 have treated 32 patients. RESULTS, COMPLICATIONS: After one year we can only provide provisional results. Among the 32 cases we experienced two complications: a rupture of the long thumb extensor tendon and a loosening of the locking screws. CONCLUSIONS: The nail plate always has a firm place in our daily routine for those cases where a stable osteosynthesis with minimal impairment of soft tissue is desired. A prerequisite for success is a correct indication and an exactly performed operative technique. Apart from a palmar splint for ten days to spare the soft tissue, immobilisation is not necessary.


Assuntos
Fixação Intramedular de Fraturas/instrumentação , Fraturas do Rádio/cirurgia , Placas Ósseas , Fixação Intramedular de Fraturas/efeitos adversos , Fixação Intramedular de Fraturas/métodos , Humanos , Imobilização , Fixadores Internos , Fraturas do Rádio/reabilitação , Fatores de Tempo
5.
Consult Pharm ; 22(4): 283-94, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17658961

RESUMO

Pain is a common complaint in the elderly patient. Chronic pain can be either nociceptive or neuropathic. Postherpetic neuralgia and painful diabetic neuropathy are two of the most common forms of neuropathic pain. Neuropathic pain can significantly affect an elderly patient's quality of life and increase use of health care resources. Several pharmacologic treatments have been shown to provide relief for neuropathic pain, including tricyclic antidepressants, anticonvulsants, tramadol, and opioids. Topical analgesics may also provide some benefit.


Assuntos
Analgésicos/uso terapêutico , Neuralgia/tratamento farmacológico , Qualidade de Vida , Idoso , Analgésicos/farmacologia , Neuropatias Diabéticas/tratamento farmacológico , Neuropatias Diabéticas/fisiopatologia , Humanos , Neuralgia/diagnóstico , Neuralgia/economia , Neuralgia/epidemiologia , Neuralgia/fisiopatologia , Neuralgia Pós-Herpética/tratamento farmacológico , Neuralgia Pós-Herpética/fisiopatologia
6.
J Am Coll Cardiol ; 38(4): 963-8, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11583865

RESUMO

OBJECTIVES: The goal of this study was to investigate the hemodynamic and circulatory adjustments to extracorporeal ultrafiltration (UF) in refractory congestive heart failure (rCHF). BACKGROUND: In rCHF, UF allows clinical improvement and restores diuretic efficacy. However, in the course of a UF session, patients are exposed to rapid variations of body fluid composition so that, as fluid is withdrawn from the intravascular compartment, hypotension or even shock could occur. METHODS: In 24 patients with rCHF undergoing UF, we measured, after every liter of plasma water removed, hemodynamics, blood gas analysis (in both systemic and pulmonary arteries), plasma volume changes (PV) and plasma refilling rate (PRR). The PV and PRR were calculated by considering hematocrit and ultrafiltrate volume. RESULTS: In all patients, UF was performed safely, without side effects or hemodynamic instability (ultrafiltrate = 4,880 +/- 896 ml). Mean right atrial, pulmonary artery and wedge pressures progressively reduced during the procedure. Cardiac output increased at the end of the procedure and, to a greater extent, 24 h later, in relation to the increase of stroke volume. Heart rate and systemic vascular resistance did not increase, and other peripheral biochemical parameters did not worsen during UF. Intravascular volume remained stable throughout the entire duration of the procedure, indicating that a proportional volume of fluid was refilled from the congested parenchyma. CONCLUSIONS: In patients with rCHF, subtraction of plasma water by UF is associated with hemodynamic improvement. Fluid refilling from the overhydrated interstitium is the major compensatory mechanism for intravascular fluid removal, and hypotension does not occur when plasma refilling rate is adequate to prevent hypovolemia.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Hemofiltração , Idoso , Gasometria , Volume Sanguíneo , Débito Cardíaco , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
J Am Coll Cardiol ; 21(2): 424-31, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8426008

RESUMO

OBJECTIVES: The aim of this study was to evaluate whether ultrafiltration is beneficial in patients with moderate congestive heart failure. BACKGROUND: Ultrafiltration is beneficial in patients with severe congestive heart failure. METHODS: We studied 36 patients in New York Heart Association functional classes II and III in stable clinical condition. Eighteen patients (group A) were randomly selected and underwent a single session of ultrafiltration (venovenous bypass, mean [+/- SEM] ultrafiltrate 1,880 +/- 174 ml, approximately 600 ml/h) and 18 (group B) served as control subjects. RESULTS: Two patients in group A and three in group B did not complete the 6-month follow-up study. In group A, soon after ultrafiltration there were significant reductions in right atrial pressure (from 8 +/- 1 to 3.4 +/- 0.7 mm Hg, pulmonary wedge pressure (from 18 +/- 2.5 to 10 +/- 1.9 mm Hg) and cardiac index (from 2.8 +/- 0.2 to 2.3 +/- 0.2 liters/min). During the follow-up period, lung function improved, extravascular lung water (X-ray score) decreased and peak oxygen consumption (ml/min per kg) increased significantly from 15.5 +/- 1 (day -1) to 17.6 +/- 0.9 (day 4), to 17.8 +/- 0.9 (day 30), to 18.9 +/- 1 (day 90) and to 19.1 +/- 1 (day 180). Oxygen consumption at anaerobic threshold (ml/min per kg) also increased significantly from 11.6 +/- 0.8 (day -1) to 13 +/- 0.7 (day 4), to 13.7 +/- 0.5 (day 30), to 15.5 +/- 0.8 (day 90) and to 15.2 +/- 0.8 (day 180). These changes were associated with increased ventilation, tidal volume and dead space/tidal volume ratio at peak exercise. The improvement in exercise performance was associated with a decrease in norepinephrine at rest, a downward shift of norepinephrine kinetics at submaximal exercise and an increase in norepinephrine during orthostatic tilt. None of these changes were recorded in group B. CONCLUSIONS: In patients with moderate congestive heart failure, ultrafiltration reduces the severity of the syndrome.


Assuntos
Insuficiência Cardíaca/terapia , Hemodinâmica/fisiologia , Hemofiltração , Idoso , Feminino , Seguimentos , Insuficiência Cardíaca/diagnóstico , Testes de Função Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Testes de Função Respiratória , Fatores de Tempo , Ultrafiltração
8.
Am J Med ; 96(3): 191-9, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8154506

RESUMO

OBJECTIVES: This study was designed to investigate whether a subclinical accumulation of fluid in the lung interstitium associated with moderate congestive heart failure interferes with the patient's functional capacity, and whether furosemide treatment can promote reabsorption of the excessive fluid. BACKGROUND: In patients with moderate congestive heart failure, pulmonary overhydration may be detected by chest roentgenography even if therapy is optimized to keep the urinary output normal and to prevent weight gain and dependent edema formation. Removal of the overhydration may help define its significance. METHODS: Patients, whose regimens of digoxin, oral furosemide, and angiotensin-converting enzyme (ACE) inhibitor therapy were kept constant, were randomly allocated to receive ultrafiltration (8 cases) or an intravenous bolus of supplemental furosemide (mean dose: 248 mg; 8 cases). The amount of body fluid removed with each method approximated 1600 mL. Functional performance was assessed with cardiopulmonary exercise tests. RESULTS: Soon after fluid withdrawal by either method, the filling pressures of the two ventricles and body weight were reduced and plasma renin activity, norepinephrine, and aldosterone were augmented. After furosemide administration, hormone levels remained elevated for the next 4 days, and during this period, patients had positive water metabolism, recovery of the elevated ventricular filling pressures, and re-occurrence of lung congestion with no improvement in functional capacity. After ultrafiltration, levels of renin, norepinephrine, and aldosterone fell to below control values within the first 48 hours and water metabolism was equilibrated at a new set point (less fluid intake and diuresis without weight gain). The favorable circulatory and ventilatory adjustments consequent to the reabsorption of lung water improved the functional capacity of these patients. That may also have restored the lung's ability to clear norepinephrine, thus restraining its facilitation of renin release. The improvement continued 3 months after the procedure. CONCLUSIONS: In patients with congestive heart failure the set point of fluid balance is altered in spite of oral furosemide therapy; supplemental intravenous furosemide does not shift the set point, at least not when combined with ACE inhibition. Excessive, although asymptomatic, lung water limits the functional capacity of the patient.


Assuntos
Furosemida/uso terapêutico , Insuficiência Cardíaca/terapia , Edema Pulmonar/fisiopatologia , Ultrafiltração , Idoso , Doença Crônica , Teste de Esforço , Feminino , Furosemida/administração & dosagem , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/fisiologia , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Edema Pulmonar/etiologia , Testes de Função Respiratória , Fatores de Tempo , Resultado do Tratamento
9.
Am J Med ; 94(1): 49-56, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8420299

RESUMO

PURPOSE: We investigated the mechanisms involved in the regulation of salt and water metabolism in patients with congestive heart failure (CHF). Extracorporeal ultrafiltration was utilized as a nonpharmacologic method for withdrawal of body fluid. PATIENTS, METHODS, AND RESULTS: In 32 consecutive patients with CHF (New York Heart Association functional class II to IV) and different degrees of water retention, 24-hour diuresis and natriuresis were inversely best correlated with the combination of circulating renin, aldosterone, norepinephrine, and renal perfusion pressure (RPP, mean aortic pressure minus mean right atrial pressure). Fluid withdrawal (600 to 5,000 mL) at a rate of 500 mL/h, until right atrial pressure decreased to 50% of baseline, caused variable humoral, circulatory, and diuretic effects that were mainly related to the extent of fluid retention. In fact, in 10 patients (Group 1) with overhydration refractory to drug therapy and with urinary output less than 1,000 mL/24 h (mean, 370 mL), soon after the procedure, plasma renin (-39%), aldosterone (-50%), and norepinephrine (-47%) were reduced and RPP was increased (+16%), and in the subsequent 24 hours, diuresis was increased by 493%; in 9 patients (Group 2) whose baseline urinary output exceeded 1,000 mL/24 h (mean, 1,785 mL), renin increased by 40%, norepinephrine, aldosterone, and RPP each decreased by 12%, and diuresis remained unchanged; in 13 patients (Group 3) with a daily urinary excretion as in Group 2 and without overhydration, RPP decreased (-7%), renin (+196%), aldosterone (+170%), and norepinephrine (+52%) increased, and diuresis decreased by 45%. There was an overall correlation (p < 0.0001) between the combination of changes in these circulatory and hormonal variables and changes in diuresis and natriuresis with ultrafiltration. CONCLUSIONS: It appears that in CHF, (1) retention of sodium and water results from an interaction of hormonal and hemodynamic (primarily RPP) alterations that may exert a reciprocal positive feedback; (2) depending on the presence and severity of fluid retention, the response to withdrawal of body fluid may vary from neurohumoral activation and restriction of diuresis to neurohumoral depression and extreme potentiation of salt and water excretion; (3) refractory CHF requires the interruption of the humoral-hemodynamic vicious circle, and ultrafiltration is able to accomplish that.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/fisiologia , Norepinefrina/metabolismo , Cloreto de Sódio/metabolismo , Ultrafiltração , Água/metabolismo , Adulto , Idoso , Aldosterona/metabolismo , Diurese , Feminino , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Renina/metabolismo , Ultrafiltração/métodos
10.
Am J Cardiol ; 68(5): 492-7, 1991 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-1872277

RESUMO

Clinical and experimental data show that type I atrial flutter is due to a reentry mechanism with an excitable gap. To define the location of the reentry circuit of atrial flutter, width of excitable gap, poststimulation cycle and pattern of reset after premature stimulus were analyzed in 18 patients during atrial flutter at multiple atrial sites (high, lateral, posterior and septal right atrium, and coronary sinus). The pattern of reset was defined as flat or increasing whether the return cycle remained unchanged or prolonged with increasing prematurity. Shorter values of the excitable gap were found at the coronary sinus (33 +/- 8 ms) and high right atrium (30 +/- 10 ms) than at the posterior (43 +/- 9 ms) or septal right atrium (45 +/- 11 ms). Intermediate values (36 +/- 8 ms) were measured at the lateral right atrium. Poststimulation cycle, corrected for atrial flutter cycle length, was shorter in the posterior (6 +/- 7 ms) and septal right atrium (5 +/- 7 ms) than in the coronary sinus (35 +/- 9 ms), and the high (23 +/- 10 ms) and lateral right atrium (15 +/- 9 ms). A flat pattern of resetting occurred more frequently at the septal (18 of 18 patients) and posterior right atrium (15 of 18) than at the lateral (8 of 18) and high right atrium (2 of 17), and was never observed at the coronary sinus. Atrial flutter was successfully terminated by overdrive atrial pacing in 15 of 18 patients, and termination was more easily obtained from the septal and posterior right atrium.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Flutter Atrial/etiologia , Eletrocardiografia , Flutter Atrial/fisiopatologia , Flutter Atrial/terapia , Estimulação Cardíaca Artificial , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
11.
Am J Cardiol ; 63(12): 812-6, 1989 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-2929438

RESUMO

The administration of class IA antiarrhythmic drugs facilities termination of atrial flutter by overdrive pacing. To investigate the electrophysiologic determinants of this effect, changes in the cycle length, the effective refractory period and the excitable gap of spontaneous type I atrial flutter were studied in 11 patients given intravenous disopyramide (3 mg/kg in 1 hour). After drug infusion, the cycle length of atrial flutter increased from 238 +/- 26 to 298 +/- 38 ms (+25%; p less than 0.001) and the effective refractory period prolonged from 169 +/- 19 to 192 +/- 25 ms (+14%; p less than 0.01). The excitable gap prolonged from 62 +/- 16 to 96 +/- 27 ms (+55%; p less than 0.001). Atrial flutter was terminated by overdrive pacing (mean cycle 203) in 10 of 11 patients; in 1 patient atrial fibrillation resulted after high rate stimulation. In the setting of an anatomically defined reentry circuit, as in type I atrial flutter, the administration of disopyramide prolongs both cycle length and refractory period. The finding of an increased excitable gap suggests that the drug exerts its prominent effect by depressing conduction velocity. A wider excitable gap allows easier penetration of the stimulus in the reentry circuit and accounts for the beneficial effects of type IA antiarrhythmic drugs on the termination of atrial flutter by overdrive pacing.


Assuntos
Flutter Atrial/fisiopatologia , Estimulação Cardíaca Artificial , Disopiramida/farmacologia , Eletrocardiografia , Idoso , Flutter Atrial/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Período Refratário Eletrofisiológico/efeitos dos fármacos
12.
Am J Cardiol ; 79(8): 1120-4, 1997 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-9114779

RESUMO

In chronic heart failure, oxygen delivery during exercise is impaired mainly because of failure of cardiac output to increase normally. Compensatory mechanisms are hemoglobin concentration increase, right-ward shift in the oxyhemoglobin dissociation curve, and blood flow redistribution from the nonexercising organs to the exercising muscles.


Assuntos
Cardiomiopatia Dilatada/metabolismo , Exercício Físico , Insuficiência Cardíaca/metabolismo , Músculo Esquelético/metabolismo , Consumo de Oxigênio , Idoso , Cardiomiopatia Dilatada/complicações , Doença Crônica , Insuficiência Cardíaca/etiologia , Humanos , Pessoa de Meia-Idade
13.
Am J Cardiol ; 76(11): 793-8, 1995 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-7572657

RESUMO

We investigated exercise capacity after fluid depletion in patients with moderate congestive heart failure (CHF). Twenty-one patients underwent ultrafiltration (mean volume +/- SEM: 1,770 +/- 135 ml). Echocardiography, tests of pulmonary function, and a cardiopulmonary exercise test with hemodynamic and esophageal pressure monitoring were performed before ultrafiltration and 3 months later. Tests without invasive measurements were repeated 4 and 30 days after ultrafiltration. Twenty-one control patients followed the same protocol but did not have ultrafiltration. Patients who underwent ultrafiltration and increased their oxygen consumption at peak exercise (peak VO2) by > 10% at the 3-month evaluation (group A1, n = 9) were separated from those who did not (group A2, n = 8); 3 patients did not complete the follow-up. Four days after the procedure, peak VO2 had risen from 17.3 +/- 0.8 to 19.3 +/- 0.9 ml/min/kg in group A1, and from 11.9 +/- 0.7 to 14.1 +/- 0.7 ml/min/kg in group A2 (p < 0.01). Plasma norepinephrine and pulmonary function were consistent with a greater severity of the syndrome in group A2. At 3 months in group A1, the relations of filling pressure to cardiac index of the right and left ventricles were shifted upward; the esophageal pressure swing (differences between end-expiratory and end-inspiratory pressure) for a given tidal volume was lower; the peak exercise dynamic lung compliance had increased from 0.10 +/- 0.05 to 0.14 +/- 0.03 L/mm Hg (p < 0.01). None of these changes were detected in group A2 and control patients.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Líquidos Corporais/metabolismo , Tolerância ao Exercício , Insuficiência Cardíaca/fisiopatologia , Coração/fisiopatologia , Pulmão/fisiopatologia , Idoso , Análise de Variância , Esôfago/fisiopatologia , Teste de Esforço , Seguimentos , Insuficiência Cardíaca/metabolismo , Hemodinâmica , Humanos , Complacência Pulmonar , Pessoa de Meia-Idade , Norepinefrina/sangue , Consumo de Oxigênio , Pressão , Volume de Ventilação Pulmonar , Ultrafiltração , Pressão Ventricular
14.
Chest ; 108(1): 94-8, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7607000

RESUMO

OBJECTIVE: Ultrafiltration (UF) can improve the exercise performance of patients with moderate congestive heart failure (CHF). Our aim was to define the starting levels of performance below which UF is beneficial. PATIENTS AND METHOD: We studied 26 patients in 2 to 3 NYHA class, whose clinical condition was stable, left ventricle ejection fraction (echocardiography) was < 35% and peak exercise oxygen uptake (VO2) was > or = 14 mL/min/kg. They underwent a single extracorporeal UF (about 600 mL of ultrafiltrate per hour). Before that, we evaluated pulmonary function (PFT), functional capacity (cardiopulmonary exercise test [CPX]), cardiac index, left ventricle ejection fraction, ventricular filling pressures, and plasma norepinephrine at rest. The PFTs and CPXs were repeated 3 months after UF. RESULTS: Sixteen patients had a rise of peak exercise VO2 > 1 mL/min/kg at the 3-month evaluation (group A, ultrafiltrate = 2,040 +/- 241 mL) and 10 did not (group B, ultrafiltrate = 1,870 +/- 169 mL). Forced expiratory volume (1 s), maximal voluntary ventilation, and vital capacity were lower in group A than in group B and improved after UF only in group A. Before UF, VO2 at peak exercise and at anaerobic threshold (15.5 +/- 0.4 mL/min/kg and 11.0 +/- 0.5, respectively) was also lower in group A than in group B (21.2 +/- 0.7 mL/min/kg and 14.8 +/- 0.9, p < 0.01). Patients whose pre-UF peak exercise VO2 was > 18.5 mL/min/kg (group B) had no increase in this variable. No significant group differences were detected regarding norepinephrine, left ventricular ejection fraction, and hemodyanmic parameters at rest. CONCLUSION: In patients with moderate CHF undergoing UF, exercise capacity improvement is inversely related to the pre-UF level of physical performance and pulmonary function; VO2 at peak exercise seems useful for identification of patients not benefiting from the procedure.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Hemofiltração , Consumo de Oxigênio , Teste de Esforço , Volume Expiratório Forçado , Hemodinâmica , Humanos , Pessoa de Meia-Idade , Volume Sistólico , Resultado do Tratamento , Capacidade Vital
15.
Eur J Heart Fail ; 1(2): 161-7, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10937926

RESUMO

BACKGROUND: Peripheral adaptations and ventricular abnormalities influence physical performance in chronic heart failure. However, the role of the heart in determining exercise capacity has not been completely elucidated. AIMS: To define cardiac determinants of exercise capacity in patients with dilated cardiomyopathy. METHODS: In 101 patients with heart failure (NYHA class II-III) due to primary or ischemic dilated cardiomyopathy we measured peak exercise oxygen consumption (Pvo2), left ventricular ejection fraction (EF), left and right atrial and ventricular cavity dimensions, mitral and tricuspid flows. Patients were subdivided in class A (Pvo2 > 20 ml/min per kg; n = 44), class B (Pvo2 16-20 ml/min per kg; n = 42) and class C (Pvo2 < 16 ml/min per kg; n = 15). RESULTS: Left ventricular diastolic and systolic dimensions, left atrial diameter, right atrial and ventricular areas were greater in class C than in class B and A; EF was lower in class C than in the other two classes; mitral peak flow velocity at early diastole (PFVE) and the ratio between early and late peak flow velocity (PFVE/PFVA) were higher in class C; mitral and tricuspid deceleration time (DT) in class B and A significantly exceeded those in class C. Peak vo2 was correlated with left and right ventricular dimensions, left atrial diameter, EF, mitral PFVE and PFVE/PFVA, mitral and tricuspid DT. Left ventricular EF, DT of the mitral valve and left ventricular diastolic diameter were independent predictors of peak vo2 at multivariate analysis. CONCLUSIONS: In patients with dilated cardiomyopathy Pvo2 is related to left and right ventricular dimensions, left and right ventricular filling pattern and EF. Both systolic and diastolic dysfunction influence functional capacity.


Assuntos
Cardiomiopatia Dilatada/complicações , Diástole/fisiologia , Exercício Físico/fisiologia , Insuficiência Cardíaca/fisiopatologia , Isquemia Miocárdica/complicações , Sístole/fisiologia , Velocidade do Fluxo Sanguíneo , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/fisiopatologia , Ecocardiografia Doppler , Teste de Esforço , Feminino , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/metabolismo , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/metabolismo , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/fisiopatologia , Variações Dependentes do Observador , Consumo de Oxigênio , Prognóstico , Volume Sistólico
16.
J Appl Physiol (1985) ; 80(2): 623-31, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8929607

RESUMO

Arteriovenous O2 content (a-vCO2) differences increase during exercise in normal subjects through several mechanisms including PO2, O2 pressure at which hemoglobin (Hb) is half saturated with O2 (P50), and Hb concentration changes. The present study was undertaken to evaluate how much these biochemical changes are relevant to a-vCO2 difference through exercise in patients with heart failure. Twenty-seven patients with congestive heart failure [10 patients in functional class A (peak exercise O2 uptake >20 ml x kg-1 x min-1), 9 in class B (20-15 ml x kg-1 x min-1), and 8 in class C (15-10 ml x kg-1 x min-1)] underwent a cardiopulmonary exercise test with once-per-minute simultaneous blood sampling from the pulmonary and systemic arteries for determination of Hb, PO2, PCO2, pH, O2 content (CO2), Hb saturation and lactic acid (pulmonary artery only), and calculation of P50. Analysis of data was done at six exercise stages: the first at rest, the last at peak exercise, and the second to the fifth at one-, two-, three-, and four-fifths of O2 consumption increase. a-vCO2 difference at peak exercise was 14.3 +/- 2.1, 16.9 +/- 2.4, and 14.7 +/- 2.1 (SD) ml/dl in class A, B, and C patients, respectively. The contribution of Hb, P50, and PO2 changes to the increments of a-vCO2 difference during exercise was 21, 17, and 63%, respectively; the only interclass difference observed was for P50, which plays a greater role in a-vCO2 difference in class A. Hb changes act mainly at the arterial site, whereas P50 and PO2 act at the venous site. Hb increase was constant through the test, venous P50 increase was greater above anaerobic threshold, and venous PO2 reduction was most remarkable at the onset of exercise; in class C patients, no venous PO2 change was recorded in the second half of exercise. Thus a-vCO2 difference increase during exercise is notable in patients with heart failure but unrelated to the severity of the syndrome. Hb, P50, and, to the greatest degree, PO2 changes participate in the increment of a-vCO2 difference. In class C patients, the lack of PO2 reduction in the second half of exercise suggests the achievement of a "whole body critical venous PO2."


Assuntos
Exercício Físico/fisiologia , Insuficiência Cardíaca/metabolismo , Hemoglobinas/metabolismo , Consumo de Oxigênio/fisiologia , Oxigênio/sangue , Limiar Anaeróbio/fisiologia , Gasometria , Dióxido de Carbono/sangue , Carboxihemoglobina/metabolismo , Teste de Esforço , Feminino , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Humanos , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade
17.
Am J Med Sci ; 321(6): 359-66, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11417750

RESUMO

BACKGROUND: In chronic heart failure (CHF), cardiac dysfunction is considered the major determinant of neurohumoral activation but the role of renal impairment has not been defined. We investigated the relationship between both cardiac and renal dysfunction and neurohumoral activation, and their possible influence on prognosis. METHODS: Hemodynamics, renal function, plasma neurohormones, and long-term follow-up were evaluated in 148 CHF patients, grouped according to systolic volume index (SVI) and serum creatinine (CRE) values: SVI > 28 mL/m2 and CRE < 1.5 mg/dL (group I, n = 55), SVI < 28 mL/m2 and CRE < 1.5 mg/dL (group II, n = 37), SVI > 28 mL/m2 and CRE > 1.5 mg/dL (group III, n = 25), SVI < 28 mL/m2 and CRE > 1.5 mg/dL (group IV, n = 31). RESULTS: Neurohormones progressively increased from Group I through IV and correlated with both cardiac and renal function. The hemodynamic pattern was similar in patients with normal or abnormal renal function, whereas neurohormones were only moderately increased in the former group and markedly increased in the latter group. Long-term survival progressively decreased from Group I through IV and was significantly poorer in patients with renal dysfunction. CONCLUSIONS: Our study confirms that, in CHF, neurohumoral activation is strictly related to long-term survival and that many factors contribute to its development and progression; among these, cardiac and renal dysfunction seem to play a major role.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Coração/fisiopatologia , Rim/fisiopatologia , Neurotransmissores/fisiologia , Adulto , Idoso , Aldosterona/sangue , Creatinina/sangue , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Norepinefrina/sangue , Prognóstico , Renina/sangue
18.
Tumori ; 81(1): 56-62, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7754544

RESUMO

AIMS AND BACKGROUND: In sarcomas of shoulder and of chest wall, latissimus dorsi muscle gives the opportunity to solve any plastic problem without recourse to free flaps. The authors report their experience in the use of latissimus dorsi pedicled flap as adjuvant procedure in the surgery of bone and soft tissue sarcoma. METHODS: The latissimus dorsi pedicled flap was used in seventeen patients to reconstruct composite tissue defects after sarcoma resection of the shoulder or of the chest wall. Three groups were recognized. The eight patients of Group I received the flap to close the chest cavity after a multiple rib resection performed to remove a tumor of the chest wall. In Group II four patients had the latissimus dorsi transported to reconstruct the soft tissue coverage over a proximal humerus prosthesis previously applied after bone tumor resection. The five patients of Group III had the flap performed at the same time of the resection of a tumor arising in the shoulder area (1 bone and 4 soft tissue sarcoma). RESULTS: Two patients of the Group II presented a recurrent skin failure. A satisfactory coverage without any flap complication was provided in all the other 15 patients (88%). CONCLUSIONS: Latissimus dorsi pedicled flap represents a reliable and effective technique to reconstruct large chest wall or shoulder soft tissue defects.


Assuntos
Músculo Esquelético/cirurgia , Osteossarcoma/cirurgia , Sarcoma/cirurgia , Ombro/cirurgia , Retalhos Cirúrgicos , Cirurgia Torácica/métodos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Chir Organi Mov ; 81(3): 287-93, 1996.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-9009412

RESUMO

Between 1989 and 1994 free gracilis muscle reinnervation was used to treat three patients severely affected with Volkmann's syndrome of the forearm. All three patients were males and they had supracondyloid fracture of the humerus, treated nonsurgically an average of 7.6 years previously. Mean age at the time of surgery was 19.3 years. The flap was transplanted in flexor function of the fingers in two of the patients, in extensor function of the wrist in one. Electromyography and successive clinical monitoring revealed an increase in contractile strength up to one year after surgery. In the first two cases final hold strength exceeded by more than 50% that of the contralateral limb, in the third case excursion of the wrist which could not be quantified, but which was useful for elementary activities was recovered. When myotendinous units for transplantation are not available, free gracilis muscle reinnervation constitutes a valid surgical solution in cases of severe Volkmann's syndrome of the forearm.


Assuntos
Síndromes Compartimentais/cirurgia , Antebraço , Músculo Esquelético/transplante , Retalhos Cirúrgicos , Adulto , Criança , Síndromes Compartimentais/etiologia , Síndromes Compartimentais/reabilitação , Humanos , Fraturas do Úmero/complicações , Imobilização , Masculino , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa