RESUMEN
The orthocladiine Chironomidae genus Stictocladius Edwards was described originally from South America. Although recognised subsequently as present also in Australia and New Zealand, the true diversity in the Neotropics has remained unclear. After more than a decade of collections of both isolated adults and aquatic immature stages, we can recognise several new taxa and associate some immature stages. Thus, we describe Stictocladius prati n. sp. as male, female, pupa and larva; Stictocladius acutus n. sp. and Stictocladius acrilobus n. sp. as male, female and pupa; Stictocladius fimbriatus n. sp. as male and female; Stictocladius fovigus n. sp. and Stictocladius nudiventer n. sp. as male and pupa; and Stictocladius privicalcar n. sp. and Stictocladius prostatus n. sp. each as male imago alone. The male and female of Stictocladius pulchripennis Edwards is redescribed and the pupa described. The male and female of Stictocladius flavozonatus Edwards and the male of Stictocladius calonotum Edwards are described. Five pupal types are described: Stictocladius sp. A (near S. acrilobus), Stictocladius sp. B (possibly S. calonotum), Stictocladius sp. C (near S. calonotum), Stictocladius sp. D (possibly S. flavozonatus) and Stictocladius sp. E with uncertain affinity. A larva from Chile of the Stictocladius 'sofour type' (Stictocladius sp. F) and an unreared larva from North America (Stictocladius sp. G) possibly belonging to S. acutus are described. Keys to named Neotropical male and female imagines of Stictocladius and to all pupal forms of Neotropical Stictocladius are provided. Some data concerning fourth instars of Stictocladius are presented. Means of differentiation from putative sister taxon Lopescladius are discussed.
Asunto(s)
Chironomidae/anatomía & histología , Chironomidae/clasificación , Américas , Animales , Femenino , Larva/anatomía & histología , Masculino , Pupa/anatomía & histologíaRESUMEN
Although hydrocephalus is usually considered a disorder of periventricular white matter, disturbance of gray matter is probably also involved. However, so far gray matter metabolism has not been studied in experimental hydrocephalus using high resolution in vivo magnetic resonance spectroscopy (MRS). Therefore 15 rats were made hydrocephalic by injection of 0.1 ml kaolin into the cisterna magna, whereas 10 sham-operated rats served as controls. (1)H MRS and magnetic resonance imaging were performed longitudinally in acute hydrocephalus 2 and 4 weeks after kaolin treatment and in chronic hydrocephalus after 6 weeks. Volumes of interest included the gray matter regions cortex, thalamus and hippocampus. In hydrocephalic animals, (1)H MRS revealed decreased glutamate levels in all examined areas at all time points. Moreover, in acute hydrocephalus disturbances were noted in the hippocampus with decreased concentrations of N-acetyl aspartate, creatine, inositol and taurine, and in the cortex with decreased taurine levels. A clear lactate peak was detected in CSF spectra from hydrocephalic rats. In addition, T2-weighted images showed increase of free water in the hippocampus. It can be concluded that glutamate metabolism is deranged in gray matter in acute and chronic hydrocephalus in rats. If confirmed in humans, early detection of glutamatergic disturbances and lactate accumulation using in vivo(1)H MRS might serve as an indication for surgical treatment of hydrocephalus before irreversible neuronal damage develops.
Asunto(s)
Encéfalo/metabolismo , Encéfalo/patología , Hidrocefalia/metabolismo , Hidrocefalia/patología , Análisis de Varianza , Animales , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Química Encefálica/fisiología , Mapeo Encefálico , Creatina/metabolismo , Modelos Animales de Enfermedad , Ácido Glutámico/metabolismo , Hidrocefalia/inducido químicamente , Procesamiento de Imagen Asistido por Computador , Inositol/metabolismo , Caolín , Ácido Láctico/metabolismo , Imagen por Resonancia Magnética/métodos , Espectroscopía de Resonancia Magnética/métodos , Masculino , Ratas , Ratas Sprague-Dawley , Factores de Tiempo , TritioRESUMEN
OBJECTIVE: To investigate the effect of thoracic aortic cross-clamping on blood perfusion of the brain, spinal cord, heart, muscular tissue and visceral organs. MATERIAL AND METHODS: Nine pigs underwent 30 min cross-clamping of the descending thoracic aorta. Multiple coloured microspheres (15.0 microm +/- 0.1) were infused into the left ventricle before and during aortic cross-clamping (XC) and after declamping (DC). Tissue samples were analysed by spectrophotometry. RESULTS: Blood perfusion of the middle and lower segments of the spinal cord was significantly reduced during aortic XC. Perfusion of the brain was not significantly altered by aortic XC, while perfusion of myocardium increased 3-fold. During XC, perfusion of the deltoid muscle and diaphragm increased 5-fold and 13-fold, respectively, while a decrease was found in the gluteus muscle. Renal blood flow was significantly reduced during XC. Finally, XC induced a significant decrease of perfusion in the bowel, spleen, liver and pancreas. CONCLUSION: During XC of the thoracic aorta, the perfusion of the muscular tissue was significantly increased proximal to the level of XC. The circulation of the brain was unchanged, probably because of autoregulatory mechanisms. Blood perfusion of the myocardium increased 3-fold during XC.
Asunto(s)
Aorta Torácica/fisiopatología , Sistema Nervioso Central/irrigación sanguínea , Vasos Coronarios , Músculo Esquelético/irrigación sanguínea , Circulación Esplácnica , Porcinos/fisiología , Procedimientos Quirúrgicos Vasculares/efectos adversos , Animales , Aorta Torácica/cirugía , Constricción , Modelos Animales de Enfermedad , Femenino , Complicaciones Intraoperatorias , Masculino , Microesferas , Flujo Sanguíneo Regional/fisiologíaRESUMEN
OBJECTIVE: To study consistency of data and completeness of reporting in a national vascular registry, NorKar, and a national administrative registry, The Norwegian patient register (NPR). DESIGN: Comparative registry-based national study supplemented with a comprehensive control of patients registered in one major hospital. MATERIAL: All patients registered with a procedure-code for treatment of AAA in NorKar or NPR during 2001 or 2002, were included. METHOD: We compared the reporting of procedure-codes, diagnosis-codes and in-hospital deaths after treatment for abdominal aortic aneurysm (AAA) in the two registries to evaluate completeness. Consistency between procedure-codes and diagnoses were evaluated within both registries. Completeness of reporting to one NorKar Local Registry was investigated in more detail in one of the hospitals. RESULTS: Compared with the NPR numbers, NorKar contained 69% of the patients treated for AAA in Norway, while completeness for NorKar member hospitals was 84%. The detailed investigation in one of the hospitals showed a completeness of 91% and a false inclusion of 5.3% of all cases treated for AAA. The consistency between procedure-codes and diagnosis-codes was 93% in both registries. We found evidence of substantial underreporting of in-hospital deaths to NorKar in several hospitals. Overall reporting of early deaths to NorKar relative to completeness of reported cases was estimated to 72%. CONCLUSION: There is an underreporting of patients with AAA to NorKar according to the NPR numbers and a need for better control of procedure-diagnosis consistency in both registries. There seems to be a substantial underreporting of early deaths to NorKar. Introduction of unique patient-identifiable data could improve the quality of both registries by making matching of data possible.
Asunto(s)
Angioplastia de Balón/estadística & datos numéricos , Aneurisma de la Aorta Abdominal/terapia , Implantación de Prótesis Vascular/estadística & datos numéricos , Recolección de Datos/normas , Evaluación de Procesos y Resultados en Atención de Salud/normas , Sistema de Registros/normas , Stents/estadística & datos numéricos , Aneurisma de la Aorta Abdominal/mortalidad , Sesgo , Causas de Muerte , Recolección de Datos/estadística & datos numéricos , Control de Formularios y Registros/normas , Control de Formularios y Registros/estadística & datos numéricos , Mortalidad Hospitalaria , Humanos , Noruega , Evaluación de Procesos y Resultados en Atención de Salud/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Sistema de Registros/estadística & datos numéricosRESUMEN
AIM OF THE STUDY: In the clinical situation there is discrepancy between various investigations regarding the cardiac response of thoracic aortic cross-clamping. The aim was therefore to investigate the hemodynamic response and blood gases during proximal aortic cross-clamping (XC) in patients operated for descending thoracic and thoracoabdominal aortic aneurysm without circulatory support. PATIENTS AND METHODS: Altogether 51 patients operated on for thoracoabdominal (n=31) or descending thoracic aortic aneurysm (n=20) were included in the investigation. All patients were operated with aortic XC, but no circulatory support was applied. Hemodynamic variables and blood gases were recorded before and during XC. RESULTS: A significant increase in cardiac output during XC from 4.7 to 6.0 liters/min was observed (p<0.01). There was a similar percentual increase in heart rate and also the proximal systolic blood pressure increased. A metabolic acidosis occurred during XC. CONCLUSION: Cardiac output was significantly increased during XC in patients operated on for thoracoabdominal or descending thoracic aneurysm using direct aortic XC without circulatory support. Simultaneously, the heart rate was increased and there was a hyperdynamic circulatory state proximal to the aortic clamp. Redistribution of the blood volume in addition to catecholamine release may be responsible for the observed changes. These observations may influence the selection of operative strategy for some of these patients.
Asunto(s)
Aorta Torácica/cirugía , Aneurisma de la Aorta Abdominal/fisiopatología , Aneurisma de la Aorta Abdominal/cirugía , Aneurisma de la Aorta Torácica/fisiopatología , Aneurisma de la Aorta Torácica/cirugía , Procedimientos Quirúrgicos Vasculares , Equilibrio Ácido-Base , Acidosis/etiología , Acidosis Respiratoria/etiología , Anciano , Anciano de 80 o más Años , Gasto Cardíaco , Constricción , Femenino , Hemodinámica , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Vasculares/efectos adversosRESUMEN
The aim of this study was to describe the results of resection and graft replacement for type III and IV thoracoabdominal aortic aneurysm repair. In this retrospective study, 27 patients underwent resection and graft replacement for type III (10) or type IV (17) thoracoabdominal aortic aneurysms. Nine patients had rupture, 12 were symptomatic, and 6 were operated on electively. The "clamp-and-sew" technique was applied in six cases. In 12 patients with type IV aneurysm the proximal part of the vascular graft was beveled, including the orifices of the celiac, superior mesenteric, and one or both renal arteries in the proximal anastomosis. Finally, eight patients underwent surgical application of a shunt for perfusion of the celiac and superior mesenteric arteries. One patient was treated with a combination of open and endovascular surgery. There were four early deaths (14.8%), all following operations for rupture, which represents a 45% mortality rate in this subgroup of patients. Two patients with type III aneurysm had postoperative paraparesis. One was symptomatic whereas the other was operated on electively. Excluding the patients with rupture, the accumulated 5-year survival rate was 65%. These results indicate that direct cross-clamping of the aorta gives limited time for performing the necessary anastomoses without inducing mesenteric ischemia. Inclusion of the orifices of the visceral arteries in the upper anastomosis is a feasible method during surgery for type IV aneurysms. Finally, shunting of the celiac and the superior mesenteric arteries seems to be useful, especially during surgery for type III aneurysms.
Asunto(s)
Aneurisma de la Aorta Abdominal/cirugía , Aneurisma de la Aorta Torácica/cirugía , Anciano , Aneurisma de la Aorta Abdominal/clasificación , Aneurisma de la Aorta Abdominal/mortalidad , Aneurisma de la Aorta Torácica/clasificación , Aneurisma de la Aorta Torácica/mortalidad , Rotura de la Aorta/mortalidad , Rotura de la Aorta/cirugía , Derivación Arteriovenosa Quirúrgica/métodos , Implantación de Prótesis Vascular , Procedimientos Quirúrgicos Cardiovasculares/métodos , Femenino , Humanos , Cuidados Intraoperatorios , Masculino , Estudios Retrospectivos , Factores de Riesgo , Tasa de SupervivenciaRESUMEN
OBJECTIVES: To describe our experience with shunting of the coeliac and superior mesenteric arteries during thoracoabdominal aneurysm repair. DESIGN: Retrospective study. MATERIAL: Eight patients undergoing resection and graft replacement of Crawford type III (5) and type IV (3) thoracoabdominal aortic aneurysms were included in this series. One patient had rupture, four were symptomatic and three were operated on electively. METHODS: A vascular graft with a sidearm was applied for the reconstructions. A T-shunt was connected to the sidearm. Following completion of the proximal anastomosis the shunt was inserted into the coeliac and superior mesenteric arteries. The anastomoses to these arteries and the renal arteries were then completed. Finally the distal anastomosis was performed. RESULTS: There was no early mortality (30 days). One patient had postoperative paraparesis, but recovered quite well. Reoperation became necessary due to sigmoid necrosis in one patient and due to haemorrhage in another. During the follow-up period four patients died but the other patients are alive between 3 and 8 years after surgery. CONCLUSION: The application of shunting of the superior mesenteric and coeliac arteries during thoracoabdominal aortic surgery is feasible and the results have been acceptable. Further investigation of the optimal blood flow needed to avoid intestinal ischaemia in a larger series of patients is desirable.
Asunto(s)
Aneurisma de la Aorta Abdominal/cirugía , Aneurisma de la Aorta Torácica/cirugía , Implantación de Prótesis Vascular/métodos , Arteria Celíaca/cirugía , Arteria Mesentérica Superior/cirugía , Anciano , Anastomosis Quirúrgica/métodos , Implantación de Prótesis Vascular/efectos adversos , Femenino , Humanos , Isquemia/etiología , Isquemia/prevención & control , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Vísceras/irrigación sanguíneaRESUMEN
OBJECTIVE: It has been suggested that certain genetic risk factors indicative of an autoimmune mechanism can be identified in patients with inflammatory aortic aneurysm (IAA). We therefore investigated whether there was a higher incidence of autoimmune diseases in patients with IAA. Further, we explored risk factors, need for in-hospital resources, and early results of treatment, in a case-control study in a university hospital setting. Material and methods From 1983 to 1994, 520 patients were operated because of abdominal aortic aneurysm (AAA). Thirty-one patients had IAA. Control subjects were matched for aneurysm rupture, emergency or elective hospital admission, and date of operation. Two noninflammatory AAA were included for every IAA. RESULTS: Of the 31 patients with IAA, 6 patients (19%) had autoimmune disease, compared with none of the control subjects (P =.0017). Two patients had rheumatoid arthritis, 2 patients had systemic lupus erythematosus, 1 had giant cell arteritis, and 1 patient had an undifferentiated seronegative polyarthritis diagnosed as rheumatoid arthritis. Nineteen patients (61%) with IAA had involvement of the duodenum, and 8 patients (26%) had hydronephrosis with ureteral involvement. Operating time was longer in the IAA group, which also had a higher need for blood transfusion. Hospital stay, intensive care unit stay, and 30-day mortality were similar in the two groups. CONCLUSION: Except for longer operating time and more need for blood transfusions in the IAA group, use of hospital resources was similar after operations to treat IAA or noninflammatory AAA. The study findings indicate an association between IAA and autoimmune disease. This is in accordance with other reports that showed a genetic risk determinant mapped to the human leukocyte antigen (HLA) molecule in these patients. Further research is necessary to explore whether IAA might be a separate entity with a role of antigen binding in the origin of the disease.
Asunto(s)
Aneurisma Infectado/epidemiología , Aneurisma Infectado/patología , Aneurisma de la Aorta Abdominal/epidemiología , Aneurisma de la Aorta Abdominal/patología , Enfermedades Autoinmunes/epidemiología , Distribución por Edad , Anciano , Anciano de 80 o más Años , Aneurisma Infectado/cirugía , Aneurisma de la Aorta Abdominal/cirugía , Enfermedades Autoinmunes/diagnóstico , Estudios de Casos y Controles , Comorbilidad , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Probabilidad , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Distribución por Sexo , Estadísticas no Paramétricas , Análisis de Supervivencia , Procedimientos Quirúrgicos VascularesRESUMEN
The aim of this study was to evaluate whether universal (all neonates) or selective (neonates belonging to the risk groups) ultrasound screening of the hips should be recommended at birth. We carried out a prospective, randomised trial between 1988 and 1992, including all newborn infants at our hospital. A total of 15 529 infants was randomised to either clinical screening and ultrasound examination of all hips or clinical screening of all hips and ultrasound examination only of those at risk. The effect of the screening was assessed by the rate of late detection of congenital or developmental hip dysplasia in the two groups. During follow-up of between six and 11 years, only one late-detected hip dysplasia was seen in the universal group, compared with five in the subjective group, representing a rate of 0.13 and 0.65 per 1,000, respectively. The difference in late detection between the two groups was not statistically significant (p = 0.22). When clinical screening is of high quality, as in our study, the effect of an additional ultrasound examination, measured as late-presenting hip dysplasia, is marginal. Under such circumstances, we consider that universal ultrasound screening is not necessary, but recommend selective ultrasound screening for neonates with abnormal or suspicious clinical findings and those with risk factors for hip dysplasia.
Asunto(s)
Luxación Congénita de la Cadera/diagnóstico por imagen , Cadera/anomalías , Cadera/diagnóstico por imagen , Inestabilidad de la Articulación/diagnóstico por imagen , Tamizaje Neonatal/métodos , Algoritmos , Femenino , Humanos , Recién Nacido , Masculino , Estudios Prospectivos , Factores de Riesgo , UltrasonografíaRESUMEN
OBJECTIVE: investigate the metabolic response of the spinal cord and the effect of allopurinol following cross clamping of the descending thoracic aorta in a porcine model. DESIGN: experimental animal study. MATERIALS: twelve domestic swine. Six pigs were pre-treated with allopurinol, while six pigs served as controls. METHODS: measurement of extracellular concentrations of glucose, pyruvate, lactate, glycerol and glutamate using microdialysis in the lumbar spinal cord. Measurement of lumbar spinal blood flow using laser Doppler technique. RESULTS: for all animals there was a significant decrease in concentrations of glucose and pyruvate together with a significant increase in the lactate-pyruvate ratio during aortic cross clamping. There was also a significant increase in glycerol concentrations 60 min after cross clamping, and a significant decrease in glutamate concentrations after 50 min. No differences in concentrations of glucose, pyruvate, lactate and glutamate or the glutamate-pyruvate ratio were observed between animals used as controls and those treated with allopurinol. The laser Doppler flux decreased to 40% of pre cross-clamp level, returning to normal values at declamping. CONCLUSION: the changes in energy-related metabolites reflect a considerable ischaemia in the spinal cord tissue but there was no convincing effect of allopurinol on the lumbar spinal cord metabolism during thoracic aortic cross clamping in this model.
Asunto(s)
Alopurinol/farmacología , Antimetabolitos/farmacología , Aorta Torácica/cirugía , Isquemia de la Médula Espinal/metabolismo , Médula Espinal/metabolismo , Animales , Constricción , Flujometría por Láser-Doppler , Microdiálisis , Flujo Sanguíneo Regional , Médula Espinal/irrigación sanguínea , Estadísticas no Paramétricas , PorcinosRESUMEN
Astrocytes are intimately involved in both glutamate and gamma-aminobutyric acid (GABA) synthesis, and ischemia-induced disruption of normal neuroastrocytic interactions may have important implications for neuronal survival. The effects of middle cerebral artery occlusion (MCAO) on neuronal and astrocytic intermediary metabolism were studied in rats 30, 60, 120, and 240 minutes after MCAO using in vivo injection of [1-13C]glucose and [1,2- 13C]acetate combined with ex vivo 13C magnetic resonance spectroscopy and high-performance liquid chromatography analysis of the ischemic core (lateral caudoputamen and lower parietal cortex) and penumbra (upper frontoparietal cortex). In the ischemic core, both neuronal and astrocytic metabolism were impaired from 30 minutes MCAO. There was a continuous loss of glutamate from glutamatergic neurons that was not replaced as neuronal glucose metabolism and use of astrocytic precursors gradually declined. In GABAergic neurons astrocytic precursors were not used in GABA synthesis at any time after MCAO, and neuronal glucose metabolism and GABA-shunt activity declined with time. No flux through the tricarboxylic acid cycle was found in GABAergic neurons at 240 minutes MCAO, indicating neuronal death. In the penumbra, the neurotransmitter pool of glutamate coming from astrocytic glutamine was preserved while neuronal metabolism progressively declined, implying that glutamine contributed significantly to glutamate excitotoxicity. In GABAergic neurons, astrocytic precursors were used to a limited extent during the initial 120 minutes, and tricarboxylic acid cycle activity was continued for 240 minutes. The present study showed the paradoxical role that astrocytes play in neuronal survival in ischemia, and changes in the use of astrocytic precursors appeared to contribute significantly to neuronal death, albeit through different mechanisms in glutamatergic and GABAergic neurons.
Asunto(s)
Astrocitos/citología , Ácido Glutámico/biosíntesis , Infarto de la Arteria Cerebral Media/metabolismo , Neuronas/citología , Ácido gamma-Aminobutírico/biosíntesis , Acetato CoA Ligasa/farmacocinética , Alanina/biosíntesis , Alanina/metabolismo , Anestésicos por Inhalación/farmacología , Animales , Ácido Aspártico/biosíntesis , Ácido Aspártico/metabolismo , Astrocitos/metabolismo , Glucemia , Isótopos de Carbono , Comunicación Celular/fisiología , Supervivencia Celular/fisiología , Ciclo del Ácido Cítrico/fisiología , Metabolismo Energético/efectos de los fármacos , Metabolismo Energético/fisiología , Lóbulo Frontal/irrigación sanguínea , Lóbulo Frontal/citología , Lóbulo Frontal/metabolismo , Glucosa/farmacocinética , Ácido Glutámico/metabolismo , Glutamina/biosíntesis , Glutamina/metabolismo , Isoflurano/farmacología , Espectroscopía de Resonancia Magnética , Masculino , Neostriado/irrigación sanguínea , Neostriado/citología , Neostriado/metabolismo , Neuronas/metabolismo , Lóbulo Parietal/irrigación sanguínea , Lóbulo Parietal/citología , Lóbulo Parietal/metabolismo , Ratas , Ratas Wistar , Ácido gamma-Aminobutírico/metabolismoRESUMEN
A regional geochemical sampling program of stream waters has been carried out in the Nord-Trøndelag region of central Norway. This area has hitherto been little affected by regional anthropogenic sources of pollution. Hydrochemical trends appear to be dominated by interplay of two main factors: (i) input of sea salts via marine aerosols in precipitation: and (ii) geological sources (mineral weathering). Factor (i) results in a predominance of Na-Cl waters near the coast, and may also be partially responsible (via proton displacement from soil ion-exchange sites by marine cations) for lower pH values in near-coastal waters. Further inland, the importance of marine salts decreases and waters become dominantly Ca-(Na)-HCO3. Sub-regional anomalies in geochemical maps for, e.g. nitrate and copper may indicate anthropogenic sources for these parameters from agriculture or mining activities.
Asunto(s)
Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisis , Abastecimiento de Agua , Agua/química , Concentración de Iones de Hidrógeno , NoruegaRESUMEN
OBJECTIVE: Utilising microdialysis to measure the changes of glucose, lactate, pyruvate and glutamate levels in the spinal cord after cross-clamping of the thoracic aorta in an established porcine model to monitor the degree of ischaemia. DESIGN: Experimental study with a porcine model. SETTING: University Hospital, Trondheim. SUBJECTS: Six pigs. MAIN OUTCOME MEASURE: Lactate, pyruvate and glutamate concentrations in the microdialysis perfusate from the spinal cord. RESULTS: A significant increase of the lactate-pyruvate ratio during the last 30 min of the 1 h clamping period, with a maximum increase of 169% from the basal value the last 10 min before declamping. No evident change in this ratio between the clamping and the reperfusion period. No significant change in glutamate levels during clamping or reperfusion period. CONCLUSION: Microdialysis reflects the ischaemic state of the spinal cord during cross-clamping of the thoracic aorta in pigs, and is well suited to study each phenomena.
Asunto(s)
Aorta Torácica/metabolismo , Aorta Torácica/cirugía , Enfermedades de la Médula Espinal/metabolismo , Enfermedades de la Médula Espinal/cirugía , Instrumentos Quirúrgicos/efectos adversos , Animales , Aorta Torácica/patología , Modelos Animales de Enfermedad , Glucosa/análisis , Ácido Glutámico/análisis , Ácido Láctico/análisis , Microdiálisis , Monitoreo Intraoperatorio , Proyectos Piloto , Ácido Pirúvico/análisis , Médula Espinal/irrigación sanguínea , Médula Espinal/patología , Enfermedades de la Médula Espinal/patología , PorcinosRESUMEN
BACKGROUND: Cross-clamping of the descending thoracic aorta (XC) induces an increase in cardiac output (CO). The intention of this study was to evaluate the high CO during XC by the use of clinically available methods (thermodilution and pulsed Doppler ultrasound) compared to transit-time ultrasound flowmetry of the ascending aorta as the gold standard. METHOD: Ten pigs were anaesthetised with ketamine and fentanyl. The descending thoracic aorta was cross-clamped for 30 min, and cardiac output was measured with pulmonary artery thermodilution technique, pulsed Doppler ultrasound on the aortic annulus and transit-time ultrasound flowmetry of the ascending aorta. RESULTS: At 15 min following XC, CO increased from 1.7 l/min to 4.6 l/min measured with transit-time ultrasound (P<0.05). With thermodilution technique, CO increased from 2.6ll/min to 5.7 l/min (P<0.05), and from 2.4 l/min to 6.0 l/min measured with Doppler ultrasound (P<0.05). There was an increase in mean arterial pressure of 81% and heart rate increased 76% (P<0.05). CONCLUSION: XC of the descending thoracic aorta induces an increase in CO of 171%. Thermodilution and pulsed Doppler ultrasound are reliable methods for detecting high cardiac output during thoracic aortic surgery.
Asunto(s)
Aorta Torácica/fisiología , Gasto Cardíaco , Termodilución , Ultrasonografía Doppler de Pulso , Animales , Femenino , Masculino , PorcinosRESUMEN
Two patients with aneurysms of the descending thoracic aorta were treated by endovascular technique. One of the patients was also treated for an infrarenal aortic aneurysm by open surgery during the same procedure. The other patient had chest pain, probably caused by an impending rupture. The procedures were performed using fluoroscopy by a C-arm. The thoracic aneurysms were replaced by an implant made of polyester where Z-stents had been applied on the inside. The prosthesis was mounted on a pusher and advanced through an introducer. When a proper position was obtained, the introducer was withdrawn, and the prosthesis was deployed immediately below the left subclavian artery. Endovascular treatment seems to represent a less traumatic procedure than open surgery. Both operations were uncomplicated and both patients were followed up for more than six months. No complications were observed. A longer follow-up period is necessary to evaluate this treatment fully.
Asunto(s)
Implantación de Prótesis Vascular , Stents , Anciano , Aorta Torácica/diagnóstico por imagen , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aneurisma de la Aorta Torácica/cirugía , Femenino , Estudios de Seguimiento , Humanos , Tomografía Computarizada por Rayos XRESUMEN
Two patients developed chylous complications following abdominal aortic aneurysm repair. One patient had chylous ascitis and was successfully treated by a peritoneo-caval shunt. The other patient developed a lymph cyst, which gradually resorbed after puncture. Chylous complications following aortic surgery are rare. Patients in bad a general condition should be treated by initial paracentesis and total parenteral nutrition, supplemented by medium-chain triglyceride and low-fat diet. If no improvement is observed on this regimen, the next step should be implementation of a peritoneo-venous shunt, whereas direct ligation of the leak should be reserved for those who are not responding to this treatment.
Asunto(s)
Aneurisma de la Aorta Abdominal/cirugía , Ascitis Quilosa/terapia , Linfocele/terapia , Complicaciones Posoperatorias/terapia , Quilo , Ascitis Quilosa/diagnóstico por imagen , Ascitis Quilosa/etiología , Humanos , Linfocele/diagnóstico por imagen , Linfocele/etiología , Masculino , Persona de Mediana Edad , Derivación Peritoneovenosa , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/etiología , Punciones , RadiografíaRESUMEN
PURPOSE: To evaluate different ultrasound modalities during implantation and follow-up of endovascular grafts for abdominal aortic aneurysm (AAA) exclusion. METHODS: Between February 1995 and May 1996, 18 patients (14 men; aged 49 to 80 years, mean 67) were treated with endovascular intervention for infrarenal AAA. Seventeen patients received Mialhe Stentor bifurcated grafts, while one patient was treated with a straight graft for pseudoaneurysm. During and after the implantation, 3.25- and 5-MHz annular array ultrasound probes were used for transabdominal visualization of the endograft. Intravascular ultrasound was applied in combination with angiography for postoperative control. RESULTS: Intraprocedurally, transabdominal two-dimensional (2D) ultrasound successfully monitored guidewire passage from the groin into the main part of the bifurcated endograft for implantation of the second limb. All implantation procedures were technically successful, but four endoleaks were identified intraprocedurally by 2D ultrasound and angiography. One healed spontaneously, two were treated with endovascular techniques at 1 and 4 months, and the last leak was scheduled for repair when the patient died of probable myocardial infarction at 2 months. During follow-up, 2D ultrasound successfully visualized all the endografts; no endoleaks were found in up to 18 months of surveillance. CONCLUSIONS: Transabdominal ultrasound imaging could be valuable in bifurcated endograft deployment both for guiding guidewire insertion and for controlling wire position before the second graft limb is connected to the main graft. Provided that satisfactory visualization of the entire endograft can be obtained, ultrasound examination may possibly replace arteriography and computed tomographic scanning as a follow-up investigation.
Asunto(s)
Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/cirugía , Prótesis Vascular/instrumentación , Ultrasonografía Intervencional , Anciano , Anciano de 80 o más Años , Aortografía , Femenino , Estudios de Seguimiento , Humanos , Periodo Intraoperatorio , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos XRESUMEN
The phosphoglucomutase (PGM) from Acetobacter xylinum, which had been cloned and expressed in Escherichia coli, has been studied. After expression, the enzyme was purified from the E. coli in a three-step process consisting of (NH4)2SO4 precipitation, gel filtration and anion-exchange chromatography. The purified enzyme gave one band on gel electrophoresis and was judged essentially free of impurities, although it was unstable when diluted without the addition of 15 microM BSA. The isoelectric point for A. xylinum PGM was 4.8 and the molar absorbance was 3.9 x 10(4) M-1.cm-1. The enzyme was reasonably heat-stable below 50 degrees C and was stable throughout the pH 5.5-7.4 range, but was 70% inactivated at pH 10.0 and completely inactivated after standing for 10 min at pH 3.0 or at pH 12.4. When isolated, the recombinant enzyme was fully active without the addition of extra Mg2+. The Km for glucose 1-phosphate was much higher than that of other PGM species reported, which accords with the production of extracellular cellulose in A. xylinum. Glucose 1,6-diphosphate is not considered to be a substrate or coenzyme but an activating cofactor like Mg2+. The following kinetic constants were determined: Vmax 81.1 units/mg; kcat and the turnover rate 135 s-1; Km (glucose 1,6-diphosphate) 0.2 microM; Km (glucose 1-phosphate) 2.6 mM; kcat/Km (glucose 1-phosphate) 5.2 x 10(4) M-1.s-1. The recombinant enzyme is considered to follow a characteristic substituted enzyme or Ping Pong reaction mechanism.
Asunto(s)
Proteínas Bacterianas/química , Gluconacetobacter xylinus/enzimología , Fosfoglucomutasa/química , Proteínas Recombinantes/química , Aniones , Proteínas Bacterianas/genética , Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Estabilidad de Enzimas/efectos de los fármacos , Gluconacetobacter xylinus/genética , Glicerol/farmacología , Calor , Concentración de Iones de Hidrógeno , Cinética , Magnesio/metabolismo , Fosfoglucomutasa/genética , Fosfoglucomutasa/aislamiento & purificación , Fosfoglucomutasa/metabolismo , Plásmidos , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Albúmina Sérica Bovina/farmacología , Trometamina , Zinc/metabolismoRESUMEN
Basically, Norway has an ample supply of water. The quality of Norwegian drinking water, however, is threatened, not the least because of pollution of surface water reservoirs. Ground water is better protected against pollution, and sub-surface water sources are being exploited more than before. At present, less than 15% of the Norwegian population uses ground water for household purposes, but the percentage is increasing rapidly Ground water is (normally) clean and has a good taste. A large number of elements can be traced in ground water; some of them in concentrations of significance for human health. The present paper reports elemental analyses of 150 water samples from ground water reservoirs in rock, collected in Vestfold (Eastern Norway) and Hordaland (Western Norway). Sixty-four elements were assessed using modern equipment such as ICP-MS. In most cases the chemical composition of the water was well within the limits set for good quality drinking water. For some of the elements one or more of the results exceeded the "highest acceptable concentrations" as defined by the Norwegian health authorities. This was the case for Al, As, Ba, Ca, Cd, F, Fe, Hg, K, Mg, Mn, Na, P, Pb, Rn and Zn. No drinking water standards have been established for Be, Mo, Th and U, which are of clear significance to the health. More research is needed to assess the relationship between drinking water chemistry and human health. The authors call for a systematic analysis of all Norwegian ground water wells, and emphasise the need for regular quality control, even of small, private water supplies.
Asunto(s)
Contaminantes Químicos del Agua/análisis , Contaminantes Radiactivos del Agua/análisis , Abastecimiento de Agua , Humanos , Noruega , Factores de Riesgo , Contaminantes Químicos del Agua/efectos adversos , Contaminantes Radiactivos del Agua/efectos adversos , Abastecimiento de Agua/normasRESUMEN
OBJECTIVES: To assess left ventricular dimensions and cardiac output during thoracic and thoracoabdominal aortic aneurysm repair. MATERIAL AND METHODS: Nine patients undergoing thoracic and thoracoabdominal aneurysm repair using direct cross-clamping without shunt or by-pass were studied prospectively. Prior to, during cross-clamping (XC) and after declamping left ventricular cross-sectional areas were monitored with transesophageal echocardiography. A pulmonary artery catheter was used for measurements of cardiac output with the thermodilution technique. RESULTS: Cardiac output increased 43% from baseline during XC (p < 0.01) and was still 55% above baseline at declamping (p < 0.05). Left ventricular end-systolic inner area was reduced 32% during XC (p < 0.01). Pulmonary artery pressures and central venous pressure increased during declamping (p < 0.05). Heart rate increased 38% from 66 beats/ min to 92 beats/min (p < 0.01) and was still 30% elevated at declamping (p < 0.01). CONCLUSION: During thoracic aortic XC, cardiac output is increased and left ventricular end-systolic dimension is reduced. TEE is a valuable supplement to pressure measurements for the evaluation of cardiac function during surgery of the thoracic aorta.