RESUMEN
In patients with end-stage heart failure (ESHF) who are candidates for isolated heart transplant (HRT), dialysis dependence (DD) is considered an indication for combined heart-kidney transplantation (HKT). HKT remains controversial in ESHF transplant candidates with nondialysis-dependent renal insufficiency (NDDRI). Using United Network for Organ Sharing data, we examined the cumulative incidences of transplant and mortality in patients with DD and NDDRI waitlisted for HKT or HRT. In all groups, 3-month waitlist mortality was dismal: 31% and 21% for HRT- and HKT-listed patients with DD and 12% and 7% for HRT- and HKT-listed patients with NDDRI. Five-year posttransplant survival was improved in HKT recipients compared with HRT recipients for both patients with DD (73% vs. 51%, p<0.001) and NDDRI (80% vs. 69%, p<0.001). Likewise, multivariable analysis associated HKT with better outcomes than HRT in HKT-listed patients, although both improved survival. These data argue strongly for HKT in ESHF transplant candidates with DD. However, in patients with NDDRI, HKT must be weighed against the possibility of renal recovery with isolated HRT. Whether HRT (followed by a staged kidney transplant in patients who do not recover renal function after HRT), as opposed to HKT, maximizes organ benefit for patients with NDDRI and ESHF requires assessment. Nevertheless, given their dismal waitlist outcomes and excellent posttransplant results, we suggest that patients with DD and NDDRI with ESHF be considered for early listing and transplant.
Asunto(s)
Insuficiencia Cardíaca/cirugía , Trasplante de Corazón , Trasplante de Riñón , Insuficiencia Renal/cirugía , Obtención de Tejidos y Órganos/estadística & datos numéricos , Listas de Espera , Adulto , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Insuficiencia Renal/complicaciones , Insuficiencia Renal/mortalidad , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
Combined heart-liver transplant (HLT) is a viable therapy for patients with concomitant end-stage heart and liver failure. Using data from the United Network for Organ Sharing database, we examined the cumulative incidences of transplant and mortality in waitlisted candidates for HLT, isolated heart transplant (HRT) and isolated liver transplant (LIV) in the Model for End-Stage Liver Disease era. The incidence of waitlist mortality was higher in HLT candidates than in HRT candidates (p = 0.001, 26% vs. 12% at 1 year) or LIV candidates (p = 0.005, 26% vs. 14% at 1 year). These differences persisted after stratifying by disease severity. Posttransplant survival was not significantly different between HLT and HRT recipients or between HLT and LIV recipients. In a multivariable model, undergoing HLT was associated with enhanced survival for HLT candidates (hazard ratio, 0.41; confidence interval, 0.21-0.79; p = 0.008), but undergoing HRT alone was not. Interestingly, 90% of HLT recipients were allocated an organ locally, compared to 60% of HRT candidates and 73% of LIV candidates (both p < 0.001). These data suggest that the current cardiac and liver allocation systems may underestimate the risk of death for patients with concomitant end-stage heart and liver failure on the HLT waitlist.
Asunto(s)
Enfermedad Hepática en Estado Terminal/cirugía , Supervivencia de Injerto/fisiología , Trasplante de Corazón , Trasplante de Hígado , Obtención de Tejidos y Órganos , Listas de Espera/mortalidad , Enfermedad Hepática en Estado Terminal/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Tasa de SupervivenciaRESUMEN
The response of isolated guinea pig hearts to perfusion with purified streptolysin O is characterized by a rapid, but transient, decrease in rate and amplitude of contraction; these reactions are superimposed upon a gradual, irreversible, loss of ventricular contractility. At ventricular standstill, the atria continue to beat spontaneously in a normal way. Isolated ventricle strips prepared from such preparations can be driven electrically, and their behavior is functionally indistinguishable from that of similar preparations made from normal hearts. Tests on spontaneously beating isolated atrial pairs show that the toxin induces a dose-dependent, reversible, decline in rate and amplitude which is accompanied by a marked, but transient, increase in the velocity of repolarization of the intracellular potential. The atrial reactions were completely blocked by atropine and potentiated by eserine. Acetylcholine was detected in the perfusates obtained by incubating a large pool of atrial tissue with active toxin, supporting the inference that the transient mechanical and electrophysiological reactions to toxin might be consequences of the release of acetylcholine from these tissues by the active toxin. Control studies showed that only the active toxin had the capacity to induce the cardiac responses. The toxin was active only in the reduced but not the oxidized form. The effects of the active toxin were modified if it were heated prior to challenge, and they could be neutralized by specific antiserum and inhibited by cholesterol. Since the driven ventricle strip was mechanically and electrophysiologically insensitive to streptolysin O, the irreversible changes in the whole heart must have occurred because of a defect in the atrioventricular conduction system.
Asunto(s)
Corazón/efectos de los fármacos , Estreptolisinas/toxicidad , Acetilcolina/análisis , Animales , Atropina/farmacología , Bovinos , Colesterol/farmacología , Cobayas , Atrios Cardíacos/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Ventrículos Cardíacos/efectos de los fármacos , Humanos , Fisostigmina/farmacología , Albúmina Sérica , Estreptolisinas/antagonistas & inhibidores , Estreptolisinas/farmacología , gammaglobulinasRESUMEN
Human heart transplantation started 40 years ago. Medical records of all cardiac transplants performed at Stanford were reviewed. A total of 1446 heart transplantations have been performed between January 1968 and December 2007 with an increase of 1-year survival from 43.1% to 90.2%. Sixty patients who were transplanted between 1968 and 1987 were identified who survived at least 20 years. Twenty-year survivors had a mean age at transplant of 29.4 +/- 13.6 years. Rejection-free and infection-free 1-year survivals were 14.3% and 18.8%, respectively. At their last follow-up, 86.7% of long-term survivors were treated for hypertension, 28.3% showed chronic renal dysfunction, 6.7% required hemodialysis, 10% were status postkidney transplantation, 13.3% were treated for diabetes mellitus, 36.7% had a history of malignancy and 43.3% had evidence of allograft vasculopathy. The half-life conditional on survival to 20 years was 28.1 years. Eleven patients received a second heart transplant after 11.9 +/- 8.0 years. The most common causes of death were allograft vasculopathy (56.3%) and nonlymphoid malignancy (25.0%). Twenty-year survival was achieved in 12.5% of patients transplanted before 1988. Although still associated with considerable morbidity, long-term survival is expected to occur at much higher rates in the future due to major advances in the field over the past decade.
Asunto(s)
Centros Médicos Académicos , Rechazo de Injerto/epidemiología , Rechazo de Injerto/cirugía , Trasplante de Corazón/mortalidad , Sobrevivientes , Adolescente , Adulto , Femenino , Supervivencia de Injerto , Trasplante de Corazón/estadística & datos numéricos , Humanos , Terapia de Inmunosupresión , Inmunosupresores , Masculino , Morbilidad , Análisis de Supervivencia , Estados Unidos/epidemiologíaRESUMEN
We examined the inotropic effect of tachycardia in nine postsurgical aortocoronary bypass graft patients (with intact cardiac innervation) and nine cardiac allograft recipients (with denervated hearts). The changes in stroke volume (SV) and velocity of circumferential fiber shortening (VCF) which accompany sudden increases and decreases in atrial pacing frequency were determined by computer-aided fluoroscopic analysis of the motion of surgically implanted midwall myocardial markers. Because the first beat after a change in rate retains the frequency characteristics of the preceding rate, we compared the first posttachycardia beat with control beats and late tachycardia beats with the first tachycardia beat; afterload and preload for each pair of beats were similar. For an increase in heart rate of 50 beats/min, SV and VCF rose 79 and 64% from the first tachycardia beat to late tachycardia beats, and SV and VCF rose 8 and 35% from control beats to the first posttachycardia beat in the innervated group. Responses in the denervated group were not significantly different from those in the innervated group. The degree of the inotropic response was positively correlated with the magnitude of the increase in heart rate (r = 0.91). The decay in augmented contractility after decreasing the rate back to control levels fits an exponential relationship with a mean t((1/2)) of 1.7 s. Thus, in conscious man, increases in heart rate represent a positive inotropic stimulus, independent of other factors influencing ventricular performance and unaffected by neural innervation, and should be considered when changes in cardiac function are interpreted during serial studies or after drug administration.
Asunto(s)
Contracción Miocárdica , Taquicardia/fisiopatología , Adolescente , Adulto , Puente de Arteria Coronaria , Corazón/inervación , Corazón/fisiopatología , Frecuencia Cardíaca , Ventrículos Cardíacos/fisiopatología , Humanos , Persona de Mediana Edad , Desnervación MuscularRESUMEN
The effects of 25-hydroxycholesterol (25-OHC), a potent inhibitor of sterol synthesis, on the growth, viability, and sterol content of C-6 rat glioma cells have been studied. Suppression of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and sterol synthesis in cells that were proliferating in medium supplemented with lipoprotein-poor fetal calf serum caused an arrest of growth after 24 hr. Prolonged incubation of serum-supplemented cells with 25-OHC resulted in a loss of morphological integrity and an 80% decline in cell viability, determined by trypan blue dye exclusion. In contrast, C-6 cells that were induced to enter a quiescent state by removal of serum from the medium remained viable and morphologically differentiated in the presence of 25-OHC. Following the addition of whole fetal calf serum to the medium, serum-free cells that had been incubated with 25-OHC for 3 days were able to resume proliferation. the selective killing of proliferating C-6 glioma cells by 25-OHC was correlated with a 45 to 50% decline in the sterol/phospholipid molar ratio, whereas the sterol/phospholipid ratio in the quiescent cells was not affected by 25-OHC. The results suggest that inhibitors of sterol synthesis may have potential as agents that might selectively decrease the growth and viability of glioma cells in the central nervous system without detriment to the normal nondividing neural cells.
Asunto(s)
Glioma/metabolismo , Hidroxicolesteroles/farmacología , Animales , Sangre , División Celular/efectos de los fármacos , Supervivencia Celular , Células Cultivadas , Represión Enzimática/efectos de los fármacos , Glioma/patología , Hidroximetilglutaril-CoA Reductasas/metabolismo , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/patología , Ratas , Esteroles/biosíntesisRESUMEN
The relationship between cell density and de novo synthesis of sterols and fatty acids has been studied in monolayer cultures of L-M cells grown in serum-free medium. Incorporation of radioactivity from [14C] acetate or 3H2O into sterols and fatty acids declined sharply as cultures approached stationary phase. The activities of 3-hydroxy-3-methylglutaryl-CoA reductase and 3-hydroxy-3-methylglutaryl-CoA synthase declined in conjunction with the decrease in sterol synthesis; however, the activity of acetoacetyl-CoA thiolase did not decrease until after sterol synthesis had begun to decline. The magnitude of the initial decline in reductase activity was not diminished when activation of latent enzyme activity was prevented by addition of fluoride to cell homogenates. The diminution in the rate of fatty acid synthesis at high cell density was accompanied by a decrease in the activity of fatty acid synthetase, whereas the activity of acetyl-CoA carboxylase increased slightly. The data suggest that lipogenesis is regulated in coordination with the changes in the rate of cell proliferation that occur when L-M cells attain a high density in monolayer culture. Moreover, these studies establish the feasibility of using the L-M cell culture system to investigate the relationship between cell density and the enzymatic regulation of lipogenesis.
Asunto(s)
Células Cultivadas/metabolismo , Ácidos Grasos/biosíntesis , Esteroles/biosíntesis , Acetil-CoA C-Acetiltransferasa/metabolismo , Animales , Ácidos Grasos/efectos adversos , Hidroximetilglutaril-CoA Reductasas/metabolismo , Hidroximetilglutaril-CoA Sintasa/metabolismo , Ratones , Esteroles/efectos adversosRESUMEN
To identify specific histologic abnormalities that could predict early cardiac rejection before the development of myocyte necrosis, 167 consecutive endomyocardial biopsy samples from 18 cardiac transplant recipients were retrospectively analyzed and 17 histologic variables were semiquantitatively graded from 0 to 3. Forty-five biopsy samples contained foci of myocyte necrosis and were labeled Rejectors. The two samples immediately preceding Rejector biopsies were labeled Predictors (n = 44). All remaining samples were labeled Others (n = 78). Endocardial and interstitial infiltrates, interstitial mononuclear cells, pyroninophilic mononuclear cells, polymorphonuclear leukocytes and other cells (eosinophils and plasma cells) were significantly increased in graded severity in Rejector biopsy samples as compared with Predictors or Others (p less than 0.001, ANOVA testing). These variables cannot distinguish Predictor biopsy specimens from Others. On the other hand, interstitial edema, perivascular karyorrhexis and perivascular infiltrate with intermyocyte extension are histologic abnormalities that can distinguish Predictor biopsy samples from Others (p less than 0.001, ANOVA testing). Multiple logistic regression analysis indicates that the relative risk of developing myocyte necrosis when a biopsy sample contains interstitial edema is 8.1. With perivascular infiltrate with intermyocyte extension in addition, the relative risk is 41.4. In summary, three histologic abnormalities have been identified that help predict the future development of myocyte necrosis within the next two endomyocardial biopsies. Biopsy specimens with these abnormalities probably represent early cardiac rejection before the development of myocyte necrosis.
Asunto(s)
Rechazo de Injerto , Trasplante de Corazón , Miocardio/patología , Biopsia , Eritrocitos/patología , Humanos , Monocitos/patología , Necrosis/patología , Neutrófilos/patología , Probabilidad , Estudios RetrospectivosRESUMEN
To ascertain the immediate effects of coronary artery bypass grafting on regional myocardial function, intraoperative transesophageal two-dimensional echocardiograms were obtained in 20 patients using a 3.5 MHz phased array transducer at the tip of a flexible gastroscope. Cross-sectional images of the left ventricle were obtained at multiple levels before skin incision and were repeated serially before and immediately after cardiopulmonary bypass. Using a computer-aided contouring system, percent systolic wall thickening was determined for eight anatomic segments in each patient at similar loading conditions (four each at mitral and papillary muscle levels). Of the 152 segments analyzed, systolic wall thickening improved from a prerevascularization mean value (+/- SEM) of 42.7 +/- 2.9% to a postrevascularization mean value of 51.6 +/- 2.6% (p less than 0.001). Thickening improved most in those segments with the worst preoperative function (p less than 0.001). Chest wall echocardiograms obtained 8.4 +/- 2.3 days after operation showed no deterioration or further improvement in segmental motion compared with transesophageal echocardiograms obtained after revascularization. Thus: regional myocardial function frequently improves immediately after bypass grafting, with increases in regional thickening being most marked in those segments demonstrating the most severe preoperative dysfunction, and this improvement appears to be sustained; and in some patients, chronic subclinical ischemic dysfunction is present which can be improved by revascularization.
Asunto(s)
Puente de Arteria Coronaria , Enfermedad Coronaria/cirugía , Ecocardiografía/métodos , Anciano , Computadores , Enfermedad Coronaria/fisiopatología , Femenino , Hemodinámica , Humanos , Cuidados Intraoperatorios , Masculino , Persona de Mediana Edad , Contracción Miocárdica , Periodo Posoperatorio , Factores de TiempoRESUMEN
The promoter of the capsid-coding genes of the autonomous parvovirus minute virus of mice (MVM) is shown to drive high levels of expression of the heterologous bovine growth hormone (bGH) gene in a bovine papilloma virus (BPV)-based shuttle vector. The expression of bGH directed by the MVM p39 promoter was, on average, higher than that obtained from the widely used metallothionein promoter. These results indicate that the MVM-p39/BPV shuttle vector will be generally useful for the high-level expression of heterologous genes.
Asunto(s)
Vectores Genéticos , Hormona del Crecimiento/genética , Regiones Promotoras Genéticas , Animales , Papillomavirus Bovino 1/genética , Bovinos , Clonación Molecular , Regulación de la Expresión Génica , Hormona del Crecimiento/biosíntesis , Virus Diminuto del Ratón/genéticaRESUMEN
The gene coding for bovine growth hormone (bGH) was isolated from a lambda-phage library constructed using bovine pituitary DNA partially digested with MboI. Expression of this gene transfected into mouse and monkey cells was studied. CV-1 monkey cells transfected with simian virus 40 (SV40) vectors containing the intact bGH gene, including the putative promoter region, did not express bGH. However, replacement of the bGH promoter with the mouse metallothionein-I (MT) promoter resulted in high-level synthesis and secretion of bGH. These results show that the bGH promoter functions poorly in CV-1 cells but CV-1 cells process and translate the bGH mRNA accurately. The MT-bGH chimeric gene was used to establish permanent bGH-secreting mouse C127 cell lines using the 69% transforming fragment of bovine papilloma virus (BPV) as the vector. One such cell line produced high levels of bGH and secreted it into the medium efficiently. Secreted bGH is processed accurately and is bioactive as judged by its ability to bind to rabbit liver membrane preparations.
Asunto(s)
Hormona del Crecimiento/genética , Animales , Bioensayo , Bovinos , Células Cultivadas , Chlorocebus aethiops , Mapeo Cromosómico , Enzimas de Restricción del ADN , ADN Recombinante , Regulación de la Expresión Génica , Vectores Genéticos , Metalotioneína/genética , Ratones , Regiones Promotoras Genéticas , Procesamiento Proteico-Postraduccional , Procesamiento Postranscripcional del ARNRESUMEN
Cardiac papillary fibroelastomas are rare and have been considered a "benign," incidental finding. With two-dimensional echocardiography, these tumors can now be readily diagnosed. A young male patient who had a stroke due to a mitral valve papillary fibroelastoma is described. In this patient, not only did preoperative echocardiography establish the diagnosis, but intraoperative transesophageal two-dimensional echocardiography was utilized to guide tumor excision.
Asunto(s)
Trastornos Cerebrovasculares/etiología , Fibroma/complicaciones , Neoplasias Cardíacas/complicaciones , Adulto , Ecocardiografía/métodos , Fibroma/diagnóstico , Fibroma/cirugía , Neoplasias Cardíacas/diagnóstico , Neoplasias Cardíacas/cirugía , Humanos , Cuidados Intraoperatorios , Masculino , Válvula Mitral/patología , Cuidados PreoperatoriosRESUMEN
Between January 1968 and March 1980, 202 hearts had been transplanted into 185 patients at Stanford University Medical Center. Occasionally, patients after transplantation develop myocardial failure which is amenable only to retransplantation. Sixteen patients underwent initial orthotopic allograft using standard techniques. Eight patients developed accelerated arteriosclerotic coronary disease, six had unrelenting rejection, and two had donor heart dysrrhythmia or right ventricular failure requiring retransplantation. One patient required a third transplant because of donor left ventricular ischemia. All sequential transplants were managed similarly to the primary transplant. Of the initial transplant hearts at risk, 60% survived for more than 1 year, and 57% survived for more than 2 years. These results are similar to those of patients not requiring retransplantation. Of the secondary transplant hearts at risk, 31% survived for more than 1 year and 29% survived for more than 2 years. The severity of infection and/or rejection contributed most significantly to secondary heart transplant mortality. Sequential orthotopic cardiac transplantation offers an acceptable alternative to patients with allograft failure. Survival is not as favorable as with initial transplantation because of the prolonged immunosuppression during sequential transplantation.
Asunto(s)
Rechazo de Injerto , Trasplante de Corazón , Humanos , Complicaciones Posoperatorias , Estudios Retrospectivos , Factores de Tiempo , Trasplante HomólogoRESUMEN
Combination CsA with corticosteroids is the most commonly used maintenance immunosuppressive regimen after cardiac transplantation, although their high-toxicity profiles frequently limit their clinical benefit. Immunosuppressive agents that would act synergistically with CsA but without the toxicity profile of corticosteroids would be clinically useful. Thalidomide was removed from the market due to its teratogenic effects, although it has known immunomodulatory activity. The purpose of this study was (1) to determine whether maintenance immunosuppression with thalidomide and subtherapeutic doses of CsA can help prevent rat cardiac allograft rejection; and (2) to compare its synergism with CsA to the commonly used corticosteroid, methylprednisolone. ACI-LEW allografts were all treated with subtherapeutic doses of CsA (10 mg/g/day, s.c.) for 4 days. When CsA was then discontinued, severe rejection developed by posttransplant day 14. Group 1 received CsA alone. Group 2 received in addition oral thalidomide 100 mg/day for 14 days. Groups 3, 4, and 5 received CsA and methylprednisolone (low dose: 0.2 mg/kg/day s.c.; moderate dose: 2.0 mg/kg/day s.c.; and high dose: 20 mg/kg/day s.c. Twelve histologic parameters of rejection were semiquantitatively graded 0-4, and total pathology scores were determined. The combination of thalidomide and subtherapeutic CsA significantly reduced the severity of myocardial necrosis, interstitial inflammation, interstitial edema, and the total pathology score. Thalidomide was found to be equally as effective as low-, moderate-, and high-dose methylprednisolone. The results of this study suggest the potential clinical role of CsA and thalidomide in maintenance immunosuppressive regimens, thereby avoiding the use of corticosteroids.
Asunto(s)
Ciclosporinas/administración & dosificación , Rechazo de Injerto/efectos de los fármacos , Trasplante de Corazón , Metilprednisolona/administración & dosificación , Talidomida/administración & dosificación , Animales , Quimioterapia Combinada , Terapia de Inmunosupresión , Masculino , Ratas , Ratas Endogámicas Lew , Trasplante HomólogoRESUMEN
Bronchoscopy with transbronchial biopsy (TBBx) and bronchoalveolar lavage (BAL) has an appreciable yield in detecting asymptomatic abnormalities in heart-lung transplant recipients (HLTR) during the early postoperative period. The utility of annual surveillance procedures has not been critically evaluated. We reviewed all annual bronchoscopies performed on 29 HLTR to determine the frequency of asymptomatic abnormalities. Surveillance bronchoscopies (SB) were performed on asymptomatic subjects with unchanged lung function compared with baseline. Surveillance/clinical bronchoscopies (SCB) were those performed in patients with stable decrements in lung function. Nineteen patients underwent 48 SB and 8 had 18 SCB. Five of 15 (33%) SB performed at one year yielded an abnormal TBBx (1 grade 2 acute rejection [AR], 1 grade 1 AR, 1 grade 1 AR with obliterative bronchiolitis [OB] and 2 Pneumocystis carinii pneumonia). At 2 or more years, TBBx was abnormal in 2 of 33 (6%, p = 0.024 compared with first year TBBx) (1 grade 1 AR, 1 lymphocytic bronchiolitis). Pathogens were identified in BAL in 19 (40%) SB. Fourteen (78%) SCB were abnormal. Nine (50%) revealed an abnormal TBBx (all OB), but only 2 (11%) of these altered patient management. Seven (39%) demonstrated pathogens in BAL. We conclude that in HLTR (1) surveillance TBBx rarely yields positive findings 2 or more years posttransplant, (2) surveillance TBBx seldom alters management in patients with stable decrements in lung function, and (3) BAL is useful to screen for potential pathogens.
Asunto(s)
Rechazo de Injerto/patología , Trasplante de Corazón-Pulmón , Adolescente , Adulto , Lavado Broncoalveolar , Broncoscopía , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Accelerated graft arteriosclerosis is a major cause of death in human heart transplantation. Despite many investigations, the pathogenesis of this disease remains undetermined and its control inadequate. In this study using a rat heart transplant model and cyclosporin A, a new immunosuppressant, acute rejection was prevented but arteriosclerotic-like vessel disease still developed consistently as early as 20 days postoperatively. The combination of cyclosporin A and dipyridamole prevented the development of this vessel disease in transplanted hearts at 20 and 50 days postoperatively. Sulfinpyrazone and cyclosporin A reduced but did not prevent the disease. These findings suggest that immunologically induced graft arteriosclerosis can be prevented in transplanted rat hearts by the combination of cyclosporin A and dipyridamole.
Asunto(s)
Arteriosclerosis/prevención & control , Rechazo de Injerto/efectos de los fármacos , Trasplante de Corazón , Inmunosupresores/uso terapéutico , Péptidos Cíclicos/uso terapéutico , Animales , Ciclosporinas , Dipiridamol/uso terapéutico , Quimioterapia Combinada , Modelos Biológicos , Ratas , Sulfinpirazona/uso terapéutico , Trasplante HomólogoRESUMEN
Uncontrolled pulmonary hypertension during autoperfusion of the heart and lungs for preservation has been described, and it may result in extensive pulmonary injury and occasional early failure of the preparation. In order to investigate the neurohumoral mediators of the vasoconstrictor response in the pulmonary circulation of the autoperfused working heart-lung preparation, heart-lung organ blocks were harvested from calves, placed in a normothermic autoperfusion circuit, and studied. Effects of beta-adrenergic stimulation with isoproterenol, nonspecific vasodilatation with nitroglycerin, alpha-adrenergic blockade with phentolamine, phospholipase A2 inhibition with methylprednisolone, cyclooxygenase inhibition with indomethacin, and white blood cell depletion were independently evaluated. Untreated animals, pre- and postexplant, served as controls. Multipoint pulmonary vascular pressure-cardiac output plots were constructed for each animal. An index of pulmonary vascular resistance was obtained from the linear relation: mean pulmonary artery pressure minus pulmonary capillary wedge pressure divided by cardiac output. An intense flow-dependent pulmonary vasoconstrictor response was confirmed to exist in the denervated bovine autoperfused working heart-lung preparation. Isoproterenol afforded better protection against this response than the other agents studied. White blood cell depletion reduced postexplant pulmonary vasoconstriction, implying that circulating polymorphonuclear leukocytes mediate the response in the autoperfused working heart-lung preparation. White blood cell depletion and the administration of selected pharmacologic agents provide modalities for regulating the pulmonary vasoconstrictor response, and thus may enhance lung preservation in the autoperfusion model.
Asunto(s)
Trasplante de Corazón , Trasplante de Corazón-Pulmón , Trasplante de Pulmón , Neurotransmisores/fisiología , Preservación de Órganos/métodos , Perfusión/métodos , Vasoconstricción , Animales , Análisis de los Gases de la Sangre , Bovinos , Corazón/fisiología , Indometacina/farmacología , Isoproterenol/farmacología , Leucopenia/fisiopatología , Pulmón/irrigación sanguínea , Pulmón/fisiología , Metilprednisolona/farmacología , Nitroglicerina/farmacología , Fentolamina/farmacología , Presión Esfenoidal Pulmonar/efectos de los fármacos , Trasplante Autólogo/métodos , Vasoconstricción/efectos de los fármacosRESUMEN
To investigate the long-term histologic consequences of combined heart and lung transplantation, heart and lung biopsies were obtained from six rhesus monkeys; two had undergone heart-lung autotransplantation 3.5 and 4.5 years previously, two were the recipients of heart-lung allografts 4.1 and 4.5 years previously, and the results were compared with two normal control animals. Cyclosporine had been used as maintenance immunosuppression in the allograft group. The heart and lung biopsies in the autograft animals were essentially normal. Dense adhesions were noted in the allografts, adn in one the visceral pleura was grossly thickened. Cardiac biopsies in the allografts were unimpressive, with a normal myocardium in one, and minimal interstitial fibrosis in the other. Intimal hyperplasia was present in the pulmonary arterioles of one of the allografted animals. Focal scarring was present in the lung of one allograft recipient, and the other animal showed severe thickening and fibrosis of the alveolar septae, as well as marked interstitial fibrosis such that large areas of the specimen were replaced by connective tissue. Histologic abnormalities in the allografted lungs correlated with the abnormal hemodynamics in these animals reported in a previous study. It is suggested that the histologic appearances in the lung are a consequence of chronic rejection, and that these findings may become a significant problem in human heart-lung transplant recipients.
Asunto(s)
Trasplante de Corazón , Trasplante de Corazón-Pulmón , Trasplante de Pulmón , Animales , Biopsia , Estudios de Seguimiento , Corazón/anatomía & histología , Pulmón/anatomía & histología , Macaca mulatta , Trasplante AutólogoRESUMEN
The development of post-transplantation coronary graft disease (CGD) is a major cause of late morbidity and mortality. Recent reports have suggested that CGD is a type of chronic vascular rejection, possibly enhanced by cofactors such as concurrent CMV infection and hyperlipidemia. It remains controversial whether established CGD can be improved by modifications in immunosuppressive therapy. The purpose of this study was to examine whether CsA could reverse or halt the progression of CGD after it was already established. Lewis to Fisher (F-344) heterotopic heart allografts develop CGD resembling human disease. Group 1 (n = 29) had no CsA therapy for chronic rat CMV (RCMV) infection in recipients for 8 weeks before transplant. Group 2 (n = 17) had chronic RCMV infection along with CsA therapy from days 15 to 28 post-transplant. Allografts were killed at 2 and 4 weeks and 90 days post-transplantation. In group 1, leukocyte adhesion to arterial endothelium and intimal hyperplasia were well established at 2 weeks and progressed to stenotic, proliferative arterial lesions at 4 weeks. In group 2, CsA therapy was effective in significantly reversing histologic parameters of vascular rejection such as leukocyte adhesion, intimal proliferation, and periarterial edema at 4 weeks. By 90 days, however, arterial pathology was as severe as in group 1. In conclusion, these results support the hypothesis that CGD is a form of chronic vascular rejection, and once established, can be significantly modified by CsA therapy. These effects are not permanent, and progressive CGD recurs after CsA therapy is discontinued.