RESUMEN
OBJECTIVES: The stability and inflammatory activity in atherosclerotic plaques may be modulated by lipids and lipoproteins as well as the pleiotropic effects of statins. The aim of this study was to analyse the effect of statin treatment as well as the relation of plasma lipids and lipoproteins to tissue composition in atherosclerotic plaques. DESIGN: Patients with stable angina and coronary plaques suitable for directional coronary atherectomy (DCA) were randomized to atorvastatin (80 mg once daily) or placebo (29 randomized, 22 underwent DCA, 11/group). After an average treatment of 10 weeks, patients underwent DCA, tissue specimens were obtained, and the tissue composition was determined by immunohistochemistry. RESULTS: Atorvastatin reduced the T-cell content, but did not change lipid, collagen, smooth muscle cell, or macrophage content. Plasma levels of apolipoprotein AI (apoAI) correlated positively with tissue collagen and inversely with metalloproteinase-9 and macrophage content. About half the specimens contained neutrophil granulocytes. CONCLUSIONS: Short-term atorvastatin treatment tended to reduce the T-cell content of atherosclerotic plaques, indicating modulation of cell-mediated immunity. High plasma levels of apoAI correlated with increased collagen content and reduced inflammation, supporting the notion that plasma apoAI stabilizes atherosclerotic plaques. The significance of neutrophils in the lesions merits further study.
Asunto(s)
Angina de Pecho/terapia , Aterectomía Coronaria , Enfermedad de la Arteria Coronaria/terapia , Ácidos Heptanoicos/uso terapéutico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Lípidos/sangre , Pirroles/uso terapéutico , Adulto , Anciano , Angina de Pecho/inmunología , Angina de Pecho/metabolismo , Apolipoproteína A-I/sangre , Atorvastatina , Biomarcadores/análisis , Colágeno/análisis , Terapia Combinada , Enfermedad de la Arteria Coronaria/inmunología , Enfermedad de la Arteria Coronaria/metabolismo , Método Doble Ciego , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Inmunidad Celular/efectos de los fármacos , Mediadores de Inflamación/sangre , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunologíaRESUMEN
BACKGROUND: A device to perform sutureless end-to-side coronary artery anastomosis has been developed by means of stent technology (GraftConnector). The present study assesses the long-term quality of the GraftConnector anastomosis in a sheep model. METHODS: In 8 adult sheep, 40-55 kg in weight, through left anterior thoracotomy, the right internal mammary artery (RIMA) was prepared and connected to the left anterior descending artery (LAD) by means of GraftConnector, on beating heart, without using any stabilizer. Ticlopidine 250 mg/day for anticoagulation for 4 weeks and Aspirin 100 mg/day for 6 months were given. The animals were sacrificed after 6 months and histological examination of anastomoses was carried out after slicing with the connector in situ for morphological analysis. RESULTS: All animals survived at 6 months. All anastomoses were patent and mean luminal width at histology was 1.8 +/- 0.2 mm; mean myotomia hyperplasia thickness was 0.21 +/- 0.1 mm. CONCLUSIONS: Long-term results demonstrate that OPCABGs performed with GraftConnector had 100% patency rate. The mean anastomotic luminal width corresponds to mean LAD's adult sheep diameter. We may speculate that myotomia hyperplasia occurred as a result of local device oversizing.
Asunto(s)
Anastomosis Interna Mamario-Coronaria/instrumentación , Animales , Vasos Coronarios/patología , Displasia Fibromuscular/patología , Ovinos , Grado de Desobstrucción Vascular/fisiología , Cicatrización de Heridas/fisiologíaRESUMEN
BACKGROUND: An animal study was carried out to compare long-term patency rates of coronary anastomoses performed with the GraftConnector versus running suture technique. METHODS: 10 sheep, 45 to 55 kg, underwent off-pump coronary artery bypass grafting (right internal mammary artery to left anterior descending artery). In 5 animals, the anastomosis was performed with a GraftConnector and in 5 animals with 7-0 running suture. Intraoperative fluoroscopy and a fluoroscopic control at 6 months were performed. After 6 months, the animals were sacrificed and the anastomoses were examined histologically. RESULTS: All animals survived at 6 months with 100% anastomosis patency rates in both groups. In the GraftConnector group, the anastomosis diameter at 6 months fluoroscopy was 118% of native left anterior descending artery versus 97% of the control group. Luminal anastomotic width at histology was 1.7 +/- 0.2 mm in the device group versus 1.6 +/- 0.1 mm in the control group. Mean intimal hyperplasia thickness was 0.21 +/- 0.1 mm in the device group versus 0.01 mm in the control group. CONCLUSIONS: The GraftConnector provides a consistent and reproducible coronary artery anastomosis and reduces technical demand and manual dexterity in coronary operations. Long-term results demonstrate that off-pump coronary artery bypass grafting performed with the GraftConnector had the same patency rate and luminal width as those performed with running suture.
Asunto(s)
Anastomosis Quirúrgica/instrumentación , Anastomosis Interna Mamario-Coronaria/instrumentación , Técnicas de Sutura , Animales , Angiografía Coronaria , Vasos Coronarios/patología , Estudios de Factibilidad , Fluoroscopía , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentación , Ovinos , Stents , Grado de Desobstrucción VascularRESUMEN
OBJECTIVE: A new device for performing quick sutureless vascular anastomosis by means of stent technology has recently been developed by Jomed International, Helsingborg, Sweden. The efficacy of this GraftConnector was studied in a sheep model. METHODS: In adult sheep, a left anterior thoracotomy under the fourth rib extended across the sternum gave good access to the left anterior descending branch (LAD) and the right internal mammary artery (RIMA). On beating hearts, the GraftConnector group had the RIMA connected to the LAD by means of the new device, while the control animals had the same anastomoses sutured with continuous 7-0 polypropylene sutures. The time for completing the anastomosis (ischemic time) was recorded and the blood flow in the RIMA was recorded with the proximal LAD open and closed, respectively. An intra-operative fluoroscopy with contrast injection directly into the graft was done. Finally the proximal LAD was ligated. The surviving animals are to be followed up. RESULTS: Seven (46%) of the 15 animals operated on with the traditional suturing technique and seven (63%) of the 11 GraftConnector sheep survived the procedures and are to be followed up. The 11 anastomoses done with the GraftConnector were completed in 2.41+/-0.2 min, and the 14 anastomoses sutured with continuous suture were completed in 6.93+/-0.419 min (P<0.0001). The RIMA blood-flows in the two groups were comparable and are presented. All the surviving animals had open anastomoses at fluoroscopy. CONCLUSIONS: Quick coronary artery anastomoses without suturing on beating hearts can be completed with the new GraftConnector. The GraftConnector creates reproducible anastomoses in much less time than suturing, the per-operative mortality in the GraftConnector Group was accordingly lower. Long-time follow-up of the patency in surviving animals is pending. The presented device may ultimately permit quick anastomoses endoscopically.
Asunto(s)
Anastomosis Quirúrgica/instrumentación , Anastomosis Interna Mamario-Coronaria/instrumentación , Anastomosis Interna Mamario-Coronaria/métodos , Animales , Estudios de Evaluación como Asunto , OvinosRESUMEN
BACKGROUND: Minor cerebral complications are common after cardiac surgery. Several biochemical markers for brain injury are under research; one of these is neuron-specific enolase (NSE). The purpose of this study was to investigate the release of this enzyme into the blood during and immediately after extracorporeal circulation and to evaluate the effect of hemolysis on this release. METHODS: Sixteen patients scheduled for elective heart surgery were included in the study. Blood samples for analysis of NSE and free hemoglobin in plasma were drawn before, during, and up to 48 hours after the end of extracorporeal circulation. The release of NSE from erythrocytes and its correlation to the release of free hemoglobin was studied by serial dilution and hemolysis in vitro. RESULTS: The peri- and postoperative course was uneventful in all patients. Extracorporeal circulation initiated a release of NSE that reached a maximum 6 hours after the end of perfusion. Thereafter, the levels declined with an estimated t1/2 of 30 hours. The concentration of free hemoglobin increased during the perfusion, with maximum levels at the end of perfusion, after which they fell rapidly to normal values. The in vitro study showed a strong linearity between the release of NSE and free hemoglobin after induced hemolysis. CONCLUSIONS: The increased levels of enolase at the end of cardiopulmonary bypass can, to a major part, be explained by the release from hemolysed erythrocytes. The value of NSE as a marker for brain injury in these situations is therefore doubtful.
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Circulación Extracorporea , Hemólisis/fisiología , Fosfopiruvato Hidratasa/sangre , Adulto , Anciano , Femenino , Hemoglobinas/análisis , Humanos , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
BACKGROUND: Reduced heart rate variability (HRV) after acute myocardial infarction (AMI) indicates poor prognosis. HRV in patients with uncomplicated coronary artery disease is reduced, and an association with poor prognosis has been suggested. The mechanism of the HRV reduction is not known, but ischemia is a possibility. AIM: To evaluate, in angina patients with no prior AMI, no other disease and drug-free, if complete revascularization and thus important reduction of ischemia by means of PTCA influences HRV. PATIENTS AND METHODS: Twenty-four-hour Holter recordings were performed at baseline prior to PTCA in 48 patients with angina and in 41 age-matched healthy control subjects. The recording was repeated 1 and 6 months after complete revascularization. In addition, HRV was registered during controlled respiration in the supine and standing positions and during cold pressure test at baseline in all angina patients and controls and in 17 consecutive angina patients 6 months after PTCA. RESULTS: Compared to controls, angina patients had a significantly reduced mean RR interval (p = 0.02), SD (p = 0.003), rMSSD (p = 0.03), pNN50 (p = 0.03), total power (p = 0.003), low- (p = 0.004) and high-frequency peak (p = 0.04), but normal SDNN, SDANN and LF/HF. One and 6 months after PTCA, 42/46 and 32/40 follow-up patients, respectively, were free of angina. Six months after PTCA, there was a significant recovery of vagal modulation seen in the frequency domain during controlled respiration, but only nonsignificant trends in HRV parameters analyzed over 24 h. CONCLUSION: Patients with uncomplicated angina had reduced HRV, mainly affecting vagal activity, but normal low frequency variability associated with mortality. Complete revascularization caused a partial normalization of vagal modulation indicating that ischemia may be one of but not the only mechanism of the HRV reduction in uncomplicated chronic coronary artery disease.
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Angina de Pecho/complicaciones , Angina de Pecho/terapia , Angioplastia Coronaria con Balón , Bradicardia/etiología , Anciano , Electrocardiografía Ambulatoria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/terapiaRESUMEN
UNLABELLED: We evaluated short and long-term effects on QT dispersion and autonomic balance after endoscopic transthoracic sympathicotomy (ETS). Heart rate variability (HRV) reflects autonomic balance of the heart. QT dispersion is a marker of cardiac electrical instability in patients with ischemic heart disease. Holter recordings for 24 h and a twelve-lead ECG were made prior to, 1 month, 1 year and 2 years after ETS. HRV was analysed in time domain and spectral analysis was performed during controlled respiration in supine position and during head up tilt. Dispersion of QT time and QTc were calculated. Of 88 patients, 62 (60) were eligible for HRV (QT-dispersion) analysis after 1 month, 39 (38) patients after 1 year and 23 (24) patients after 2 years. The HRV analysis showed a significant change of indices reflecting sympatho-vagal balance indicating significantly reduced sympathetic (LF) and increased vagal (HF, rMSSD) tone. These changes still persisted after 2 years. Global HRV increased over time with significant elevation of SDANN after 2 years. QT dispersion was significantly reduced 1 month after surgery and the dispersion was further diminished 2 years later. CONCLUSION: ETS changed HRV and QT dispersion which could imply reduced risk for malignant arrhythmias and death after ETS.
Asunto(s)
Angina de Pecho/fisiopatología , Electrocardiografía Ambulatoria , Ganglios Simpáticos/fisiopatología , Ganglionectomía/métodos , Frecuencia Cardíaca , Corazón/inervación , Anciano , Angina de Pecho/diagnóstico , Angina de Pecho/cirugía , Ritmo Circadiano , Angiografía Coronaria , Endoscopía , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Ventriculografía con Radionúclidos , Estudios Retrospectivos , Pruebas de Mesa InclinadaRESUMEN
BACKGROUND: Because of the limited supply of donor hearts, prospective recipients continue to die while on the waiting list for heart transplantation. Use of long-term mechanical circulatory support devices as a bridge to transplantation may reduce this mortality. However, with the present state of technology, continued clinical evaluation of the various long-term, mechanical circulatory support devices available is mandatory. METHODS: Sixteen patients were bridged with the HeartMate left ventricular assist device (LVAD) to heart transplantation for New York Heart Association functional class IV cardiac failure. Twelve pneumatic and six electric devices were used. The mean cardiac index and the mean pulmonary vascular resistance of the patient cohort were 1.71 x min(-1) x m(-2) and 3.1 Wood units, respectively. RESULTS: The mean LVAD support time per transplanted patient was 237 days, with a cumulative LVAD support time of about 7.2 years. Bleeding was the main operative and postoperative complication. Two patients suffered from neurologic complications and there were two major incidents of device malfunction. Twelve patients (75%) now have received a transplant, 3 (19%) are awaiting a transplant, and in 1 patient (6%), the device was explanted after spontaneous left ventricular recovery. Eleven of the 12 patients who received a transplant are alive and doing well. The HeartMate LVAD gave adequate circulatory support over extended periods of time and reversed the vital organ dysfunction. Since the start of the LVAD program, only 1 patient has died on our heart transplantation waiting list, compared to nine deaths in the 2 preceding years. CONCLUSIONS: The HeartMate LVAD bridge to heart transplantation can be performed with low post-LVAD implantation and posttransplantation mortality and offers 1- and 2-year posttransplantation actuarial survival rates comparable to those for nonbridged heart transplant recipients.
Asunto(s)
Trasplante de Corazón , Corazón Auxiliar , Análisis Actuarial , Adolescente , Adulto , Pérdida de Sangre Quirúrgica , Gasto Cardíaco , Trastornos Cerebrovasculares/etiología , Estudios de Cohortes , Diseño de Equipo , Falla de Equipo , Estudios de Evaluación como Asunto , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/clasificación , Insuficiencia Cardíaca/terapia , Corazón Auxiliar/efectos adversos , Corazón Auxiliar/clasificación , Humanos , Masculino , Ensayo de Materiales , Ciencia del Laboratorio Clínico , Persona de Mediana Edad , Hemorragia Posoperatoria , Arteria Pulmonar , Tasa de Supervivencia , Factores de Tiempo , Resistencia Vascular , Listas de EsperaRESUMEN
Between 1990 and 1995 39 patients were lung transplanted at the University Hospital in Lund. This is a retrospective review of survival and lung function in these patients. There were 17 single-lung transplants (SLT), 21 double-lung transplants (DLT) and 1 heart-lung transplant (HLT). Seven patients died during the period, giving an overall survival of 82%. One-year survival according to Kaplan-Meier survival analysis was 87%, and 2-year survival was 83%. Vital capacity and forced expiratory volume in 1 s (FEV1) 1 year after transplantation were 91% and 100% of predicted, respectively, in the DLT group and 60% and 50% in the SLT group. Bronchiolitis obliterans syndrome (BOS) developed in 11 of the 35 patients (31%) surviving more than 6 months, 2/21 in the DLT group and 8/13 in the SLT group and in the patient with HLT. The median time until detection of BOS was 11 months after the operation (range 6-18 months). Working capacity 1 year after transplantation was 60% of predicted in the DLT group and 47% of predicted in the SLT group. Ventilatory capacity was no longer function limiting. Lung transplantation today is a therapeutic option with a good medium-term survival and good functional results in selected patients with severe lung disease.
Asunto(s)
Hospitales Universitarios , Trasplante de Pulmón , Adolescente , Adulto , Bronquiolitis Obliterante/etiología , Bronquiolitis Obliterante/mortalidad , Bronquiolitis Obliterante/fisiopatología , Niño , Preescolar , Femenino , Estudios de Seguimiento , Humanos , Enfermedades Pulmonares/cirugía , Trasplante de Pulmón/efectos adversos , Trasplante de Pulmón/mortalidad , Trasplante de Pulmón/rehabilitación , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Valor Predictivo de las Pruebas , Pruebas de Función Respiratoria , Estudios Retrospectivos , Tasa de Supervivencia , Suecia/epidemiología , Síndrome , Evaluación de Capacidad de TrabajoRESUMEN
BACKGROUND: To enhance clinical decision support, presented messages are increasingly supplemented with information from the medical literature. The goal of this study was to identify types of evidence that can lead to the biggest difference. METHODS: Seven versions of a questionnaire were mailed to randomly selected active family practice physicians and internists across the United States. They were asked about the perceived values of evidence from randomized controlled trials, locally developed recommendations, no evidence, cost-effectiveness studies, expert opinion, epidemiologic studies, and clinical studies. Analysis of variance and pairwise comparisons were used for statistical testing. RESULTS: Seventy-six (52%) physicians responded. On a Likert scale from one to six, randomized controlled clinical trial was the highest rated evidence (mean 5.07, SD +/- 1.14). Such evidence was significantly superior to locally developed recommendations and no evidence at all (P < .05). The interaction was also strong between the types of evidence and clinical areas (P = .0001). CONCLUSION: While most health care organizations present data without interpretation or simply try to enforce locally developed recommendations, such approaches appear to be inferior to techniques of reporting data with pertinent controlled evidence from the literature. Investigating physicians' perceptions is likely to benefit the design of computer generated messages.
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Actitud del Personal de Salud , Técnicas de Apoyo para la Decisión , Medicina Basada en la Evidencia , Adulto , Anciano , Análisis de Varianza , Recolección de Datos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Médicos/psicología , Atención Primaria de Salud , Ensayos Clínicos Controlados Aleatorios como Asunto , Estados UnidosRESUMEN
OBJECTIVE: To investigate the appearance and elimination of brain-specific S-100 protein in serum during and immediately after cardiopulmonary bypass. DESIGN: Prospective study. PARTICIPANTS: Twenty-nine patients undergoing elective cardiac surgery. INTERVENTIONS: Twenty-seven patients were operated on for coronary artery disease; two patients had valve replacement. Serial measurements of S-100 in arterial blood during and up to 48 hours after cardiopulmonary bypass were made. MEASUREMENTS AND MAIN RESULTS: The perioperative and postoperative course was uneventful in 25 patients, with no clinical signs of neurologic complications. S-100 was not detected before extracorporeal circulation was started. Detectable concentrations (detection limit, 0.2 microgram/L) appeared in serum after 10 minutes of perfusion and reached maximum levels, 2.43 +/- 0.3 micrograms/L, at the end of bypass. The levels then declined with elimination t1/2 of 2.2 hours. Only two patients had detectable concentrations of S-100 48 hours after the end of bypass. In four patients who developed clinical signs of cerebral injury, levels of S-100 were significantly higher at the end of bypass and 24 hours after the end of bypass. CONCLUSIONS: Cardiopulmonary bypass initiates a release of brain-specific S-100 to the systemic circulation. The release and elimination of S-100 seem to follow a reproducible pattern in patients with no signs of cerebral injury. In patients who developed cerebral injury, the concentrations of S-100 in blood were increased, thus suggesting that S-100 may be a usable marker for cerebral injury after extracorporeal circulation.
Asunto(s)
Encefalopatías/diagnóstico , Puente Cardiopulmonar/efectos adversos , Complicaciones Posoperatorias/diagnóstico , Proteínas S100/sangre , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
A new imaging technology is under advanced development that has several key advantages over conventional forms of microimaging performed with standard light microscopes, confocal light microscopes, and electron microscopes. The image created by this microscope possesses several unique features: It is intrinsically three-dimensional; it can be formed with very high contrast, a characteristic of the phase-sensitive nature of the recording; the information contained in the image is obtained in a single exposure of the specimen, a feature that eliminates the accumulation of damage to living systems that can occur with techniques utilizing multiple exposures; the method of image construction is fundamentally free from aberration (distortion), thereby obviating the need to employ complex procedures for correction; the exact focal plane of any optical section is digitally determined through computation and is not based on any mechanical adjustments; and the principles of operation, including the computational processes and modalities of image presentation, are uniform over the full range of spectral coverage spanning from the visible (approximately 500 nm) to the X-ray (approximately 0.3 nm) regions. The application of this new technology is expected to open new cost-effective avenues to the understanding, prevention and treatment of broad areas of human disease.
Asunto(s)
Holografía , Procesamiento de Imagen Asistido por Computador/métodos , Microscopía/métodos , Animales , Drosophila melanogaster , Humanos , Procesamiento de Imagen Asistido por Computador/instrumentación , Rayos Ultravioleta , Rayos XRESUMEN
BACKGROUND: There is no simple method to determine the incidence or severity of brain injury after a cardiac operation. A serum marker equivalent to cardiac enzymes is required. S100 protein leaks from the cerebrospinal fluid to blood after cerebral injury. We sought to determine the pattern of release after extracorporeal circulation (ECC). METHODS: Thirty-four patients without neurologic problems underwent coronary bypass using ECC. Four had carotid stenoses. Nine others underwent coronary bypass without ECC. Serum S100 levels were measured before, during, and after the operation. RESULTS: S100 was not detected before sternotomy. Postoperative levels of S100 were related to duration of perfusion (r = 0.89, p < 0.001). Patients who did not have ECC had undetectable or fractionally raised levels except in 1 who suffered a stroke. No patient in whom ECC was used suffered an event, but those with carotid stenosis had greater S100 levels. CONCLUSIONS: S100 protein leaks into blood during ECC and may reflect both cerebral injury and increased permeability of the blood brain barrier. S100 is a promising marker for cerebral injury in cardiac surgery if elevated levels can be linked with clinical outcome.
Asunto(s)
Puente Cardiopulmonar/efectos adversos , Trastornos Cerebrovasculares/diagnóstico , Proteínas S100/sangre , Anciano , Biomarcadores/sangre , Trastornos Cerebrovasculares/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y EspecificidadRESUMEN
Four transplant candidates fulfilling the Food and Drug Administration criteria for a permanent left ventricular assist device received a pneumatic HeartMate system as a bridge to heart transplantation. All patients survived and were fully rehabilitated at the time of transplantation, which was carried out 2 to 6 months after the initial operation. There were no major complications associated with the procedures. We are impressed by the effectiveness and safety of the device.
Asunto(s)
Cardiomiopatía Dilatada/terapia , Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Adulto , Diseño de Equipo , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Standardized intra-abdominal hemorrhage was induced in 7 anesthetized pigs. The resulting hypovolemic shock was treated with pneumatic anti-shock garment (PASG) followed by intra-aortic balloon occlusion. The effects of this treatment on circulation, lung mechanics and gas exchange were studied. Hemorrhage was induced by pulling out sutures introduced in the inferior caval vein. We found that the use of PASG partially restored mean arterial blood pressure from 44 +/- 6 to 66 +/- 6 mm Hg. When intraaortic balloon occlusion was added, the arterial pressure returned to basal levels. Cardiac output fell severely due to the hemorrhage from 3.7 +/- 0.2 to 1.3 +/- 0.2 liters/min and could not be restored during the treatment. A severe fall in total lung compliance was recorded after inflation of the PASG from 18.6 +/- 0.9 to 10 +/- 0.7 ml/cm H2O, this was accompanied by a fall in alveolar ventilation. These findings emphasize the severe restriction in lung function that occurred during treatment with PASG. Both parameters returned to near normal values when the PASG was deflated and the intra-aortic balloon was inflated. Pulmonary vascular resistance increased by more than 400% and remained high during the study period. There was no change in arterial PO2, however the fall in mixed venous PO2 caused by hemorrhage was reversed at the end of the treatment. Indirect monitoring of cerebral function by continuous EEG showed a decreased voltage during the hemorrhage, this was reversed by the combined treatment. We conclude that the outlined treatment makes it possible to restore central hemodynamics and preserve cerebral function at least for a short period of time until definite surgical treatment can be performed. However, severe restriction on lung mechanics, especially when PASG was inflated, makes it probable that ventilatory support can be necessary in such cases.
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Cateterismo , Trajes Gravitatorios , Intercambio Gaseoso Pulmonar , Mecánica Respiratoria , Choque Hemorrágico/fisiopatología , Abdomen , Animales , Modelos Animales de Enfermedad , Hemodinámica , Pruebas de Función Respiratoria , Choque Hemorrágico/etiología , Choque Hemorrágico/terapia , PorcinosRESUMEN
Glutathione transferases play an important role in the detoxification of many different endogeneous and exogenous compounds such as metabolites of polycyclic aromatic hydrocarbons (PAH) of cigarette tar. There is evidence that PAH may be atherogenic. The glutathione transferase activity towards trans-stilbene oxide (GST-tSBO) can be separated in blood in GST-positive and GST-negative phenotypes. We have previously suggested that the GST-negative phenotype may be associated with a higher morbidity in intermittent claudication among middle aged smokers. In the present study, GST-tSBO could easily be measured in human, rabbit and bovine arterial smooth muscle cells (SMC) in culture. The level of GST-tSBO was higher in rabbit than in bovine SMC. It was stable in bovine SMC during 5 cell passages and it could be induced twofold by long-time incubation with dimethylsulfoxide-soluble particulate matter from cigarette smoke or 3,4-benzo(a)pyrene. There was a positive correlation between the level of GST-tSBO in blood and in "healthy" arterial and venous tissue from individuals operated with coronary bypass. The enzyme levels in arterial tissue were lower than in venous tissue. GST-tSBO in atherosclerotic segments of human arteries was lower than in "healthy" segments from the same artery. These findings suggest that the arterial wall may have a low defense against toxic compounds that may decrease further as atherosclerosis proceeds. It is concluded that SMC are suitable for the study of the effects of PAH in relation to GST-tSBO and that the enzyme activity in blood will reflect the individual GST-tSBO phenotype also in vascular tissues.
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Glutatión Transferasa/metabolismo , Músculo Liso Vascular/enzimología , Adulto , Animales , Arteriosclerosis/patología , Bovinos , Células Cultivadas , Femenino , Glutatión Transferasa/genética , Humanos , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Músculo Liso Vascular/efectos de los fármacos , Fenotipo , Compuestos Policíclicos/farmacología , Conejos , Fumar/patología , Estilbenos/metabolismoRESUMEN
We describe a holographic microscope with a spatial resolution approaching the diffraction limit. The instrument uses a tiny drop of glycerol as a lens to create the spherically diverging reference illumination necessary for Fourier-transform holography. Measurement of the point-spread function, which is obtained by imaging a knife edge in dark-field illumination, indicates a transverse resolution of 1.4 microm with wavelength lambda = 514.5 nm. Longitudinal resolution is obtained from the holograms by the numerical equivalent of optical sectioning. We describe the method of reconstruction and demonstrate the microscope's capability with selected biological specimens. The instrument offers two unique capabilities: (1) it can collect three-dimensional information in a single pulse of light, avoiding specimen damage and bleaching; and (2) it can record three-dimensional motion pictures from a series of light pulses. The conceptual design is applicable to a broad range of wavelengths and we discuss extension to the x-ray regime.
RESUMEN
Euro-Collins (ECS) and UCLA-formula organ preservation solutions induced strong vasocontraction in porcine pulmonary arteries when studied in organ baths at temperatures of 37 degrees C and 30 degrees C. At 20 degrees C ECS induced a 30% contraction, but at 6 degrees C no contraction (n = 5) or a weak contraction (n = 1) was elicited. Neither prostaglandin E1 nor nifedipine caused any significant reduction of the vasocontraction elicited by ECS and UCLA. Krebs solution, enriched with potassium in amounts corresponding to those in ECS (115 mmol/L) or UCLA (30 mmol/L), induced vasocontraction comparing well with those induced by ECS or UCLA, indicating that it is the high potassium content that causes the vasocontraction. In a second experiment lung segments were stored at 4 degrees C for 9 hours in ECS, UCLA, or Krebs solution. Pulmonary arterial segments were then studied in organ baths at 37 degrees C. The choice of preservation solution did not significantly affect the contractile properties of potassium, noradrenaline, or the thromboxane mimic U-46619. To conclude, high potassium contents in organ preservation solutions induce strong pulmonary vasocontraction in lung temperatures greater than 20 degrees C but not in temperatures less than 10 degrees C. These vasocontractions are not significantly reduced by prostaglandin E1 or nifedipine. We suggest that the initial preservation solution used to cool down the lungs should contain 4 mmol/L or no potassium. When the lung temperature is less than 10 degrees C, a second perfusion might be done, and then a high potassium content (if thought to be essential) will not cause vasocontraction.
Asunto(s)
Soluciones Hipertónicas/farmacología , Soluciones Isotónicas/farmacología , Contracción Muscular/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Preservación de Órganos , Potasio/farmacología , Arteria Pulmonar/efectos de los fármacos , Soluciones , Alprostadil/farmacología , Animales , Relación Dosis-Respuesta a Droga , Nifedipino/farmacología , Potasio/antagonistas & inhibidores , PorcinosRESUMEN
Intravenous infusions of 750 and 1000 ml 2.2% sodium citrate were given over a 60 min period to 17 pigs to study its effect on aortic pressure, electrocardiogram, ionised calcium, and citrate clearance. In group 1 (seven pigs) the animals did not receive calcium and the median survival time was 30 min (range 20-70 min). In groups 2 and 3 (five in each group) the pigs were treated with calcium chloride infusions (1 ml 10% calcium chloride to 10 ml citrate) and they all survived. In group 1 the ionised calcium concentrations in blood fell to values below 0.4 mmol/l, after which the blood pressure dropped abruptly. In the animals treated with calcium the mean ionised calcium concentration fell to 0.6 mmol/l, whereas total calcium increased to more than 7 mmol/l. The aortic pressure was consistently within normal values in the groups treated with calcium, but in the group that was not treated the blood pressure fell dramatically. There was no correlation between electrocardiographic changes and ionised calcium concentrations. In summary, calcium was an effective antidote to lethal citrate intoxication, and the only reliable method of determining the necessary dose of calcium was monitoring of ionised calcium concentrations.