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1.
Ann Surg Oncol ; 30(13): 7996-8005, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37782413

RESUMEN

BACKGROUND: Histopathological growth patterns (HGPs) are a prognostic biomarker in colorectal liver metastases (CRLM). Desmoplastic HGP (dHGP) is associated with liver-only recurrence and superior overall survival (OS), while non-dHGP is associated with multi-organ recurrence and inferior OS. This study investigated the predictive value of HGPs for adjuvant hepatic arterial infusion pump (HAIP) chemotherapy in CRLM. METHODS: Patients undergoing resection of CRLM and perioperative systemic chemotherapy in two centers were included. Survival outcomes and the predictive value of HAIP versus no HAIP per HGP group were evaluated through Kaplan-Meier and Cox regression methods, respectively. RESULTS: We included 1233 patients. In the dHGP group (n = 291, 24%), HAIP chemotherapy was administered in 75 patients (26%). In the non-dHGP group (n = 942, 76%), HAIP chemotherapy was administered in 247 patients (26%). dHGP was associated with improved overall survival (OS, HR 0.49, 95% CI 0.32-0.73, p < 0.001). HAIP chemotherapy was associated with improved OS (HR 0.61, 95% CI 0.45-0.82, p < 0.001). No interaction could be demonstrated between HGP and HAIP on OS (HR 1.29, 95% CI 0.72-2.32, p = 0.40). CONCLUSIONS: There is no evidence that HGPs of CRLM modify the survival benefit of adjuvant HAIP chemotherapy in patients with resected CRLM.


Asunto(s)
Neoplasias Colorrectales , Neoplasias Hepáticas , Humanos , Neoplasias Colorrectales/patología , Hepatectomía , Estudios Retrospectivos , Quimioterapia Adyuvante , Neoplasias Hepáticas/cirugía , Bombas de Infusión Implantables
2.
Colorectal Dis ; 20(2): 134-143, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28782277

RESUMEN

AIM: Sacral neuromodulation (SNM) is a minimally invasive therapy for functional constipation (FC) and is most often used to treat adults. Recent studies suggest that SNM may also beneficial in children. However, comparative data regarding preferred age of SNM for FC are lacking. Therefore, long-term results of SNM for FC were compared between children and adults. METHOD: All patients treated with SNM for FC between 2004 and 2015 were evaluated. Outcomes of children (age 10-18 years) were compared with those for adults (≥ 18 years). The primary end-point was a defaecation frequency of three or more times per week, which is consistent with the ROME-III criteria. Secondary outcomes were quality of life (QoL; SF-36) and the Cleveland Clinic Constipation Score. RESULTS: One hundred and eighty patients (45 children, 135 adults) were eligible for SNM. The mean age was 15.8 (children) and 41.4 years (adults). One hundred and twenty-six patients received permanent SNM (38 children, 88 adults). Mean follow-up was 47 months in both groups. Defaecation frequency increased in both groups after SNM compared with baseline. Defaecation frequency in adults was higher than in children. The increased defaecation frequency was maintained during the entire follow-up period in both groups. QoL of children was impaired compared with the Dutch population with regard to bodily pain, general health and vitality. Adults had worse QoL with regard to physical functioning, bodily pain, general health, vitality and social functioning compared with the Dutch population. QoL of children did not differ from adults. CONCLUSION: Sacral neuromodulation (SNM) should be considered in children (< 18 years) with FC. However, the indication of SNM for FC remains debatable considering the limited improvements and high costs.


Asunto(s)
Factores de Edad , Estreñimiento/terapia , Terapia por Estimulación Eléctrica/métodos , Adolescente , Adulto , Niño , Estreñimiento/fisiopatología , Defecación/fisiología , Femenino , Humanos , Masculino , Calidad de Vida , Estudios Retrospectivos , Sacro/inervación , Resultado del Tratamiento
3.
Nat Prod Rep ; 32(6): 841-64, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25891138

RESUMEN

This review highlights recent innovative synthetic strategies developed for the stereoselective construction of natural complex decalin systems. It offers an insight into various synthetic targets and approaches and provides information for developments within the area of natural products as well as synthetic methodology.


Asunto(s)
Alcanos/síntesis química , Productos Biológicos/síntesis química , Compuestos Bicíclicos con Puentes/síntesis química , Naftalenos/síntesis química , Alcanos/química , Productos Biológicos/química , Compuestos Bicíclicos con Puentes/química , Estructura Molecular , Naftalenos/química
4.
Clin Exp Metastasis ; 40(1): 69-77, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36326981

RESUMEN

Histopathological Growth Patterns (HGPs) have prognostic and predictive value in patients with Colorectal Liver Metastases (CRLM). This study examined whether preoperative measurement of Circulating Tumour Cells (CTCs) is associated with HGP. CTCs were prospectively enumerated in 7.5 ml of blood using the FDA-approved CellSearch system in patients who underwent local treatment of CRLM with curative intent between 2008 and 2021. All CTC samples were collected on the day of local treatment. Patients treated with neoadjuvant chemotherapy for CRLM or with extrahepatic disease at the time of CTC sampling were excluded. HGP was scored retrospectively following the current consensus guidelines. The association between CTCs and HGP was investigated through multivariable logistic regression. Data were available for 177 patients, desmoplastic HGP (dHGP) was observed in 34 patients (19%). There were no statistically significant differences in patient and tumour characteristics between dHGP and non-dHGP at baseline. Patients with dHGP had longer overall - and disease-free survival (logrank p = 0.003 and 0.003, respectively) compared to patients with non-dHGP. CTCs were not detected in 25(74%) of dHGP patients and in 68(48%) of non-dHGP patients (chi-squared p = 0.006). Preoperative absence of CTCs was the only significant predictor for dHGP in multivariable logistic regression (Odds Ratio 2.7, 95%CI 1.1-6.8, p = 0.028), Table 3. Preoperative absence of CTCs is associated with dHGP in chemo naive CRLM patients without extrahepatic disease. Based on our results, CTC count alone is not sufficient to preoperatively identify HGPs, but integration of CTC count in multivariable prediction models may aid the preoperative identification of HGPs of CRLM.


Asunto(s)
Neoplasias Colorrectales , Neoplasias Hepáticas , Células Neoplásicas Circulantes , Humanos , Células Neoplásicas Circulantes/patología , Estudios Retrospectivos , Neoplasias Colorrectales/patología , Neoplasias Hepáticas/secundario , Pronóstico
5.
Clin Exp Metastasis ; 40(3): 227-234, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37183203

RESUMEN

Histopathological growth patterns (HGPs) of liver metastases represent a potential biomarker for prognosis after resection. They have never been studied in neuroendocrine tumor liver metastases (NETLM). This study evaluated if distinct HGPs can be observed in resected NETLM and if they have prognostic value. Sixty-three patients who underwent resection of NETLM between 01-01-2001 and 31-12-2021 were retrospectively included. HGPs were scored on Haematoxylin&Eosin slides using light microscopy, distinguishing desmoplastic- (dHGP), pushing- (pHGP) and replacement HGP (rHGP). Average HGP scores were calculated per patient. Each patient was classified according to predominant HGP. Overall and Disease-Free Survival (OS and DFS) were evaluated through Kaplan-Meier analysis and Cox regression. Eighteen patients had predominant dHGP (29%), 33 had predominant pHGP (52%) and 11 had predominant rHGP (17%). One patient had mixed HGP (2%). Five-year OS was 76% (95%CI: 66-87%) for the overall cohort. Five-year OS was 92% (95%CI: 77-100%) for dHGP, was 73% (95%CI: 59-91%) for pHGP, 50% (95%CI: 25-100%) for rHGP. Five-year DFS was 39% (95%CI: 19-83%) for dHGP, 44% (95%CI: 27-71%) for rHGP and 50% (95%CI: 23-100%) for pHGP. There was no significant association between HGP and OS or DFS in multivariable analysis. Distinct HGPs could be identified in NETLM. In patients who underwent resection of NETLM, no association was found between HGPs and postoperative survival. Half of the patients with NETLM have a predominant pushing growth pattern, which is a rare growth pattern in liver metastases from breast and colorectal cancer.


Asunto(s)
Neoplasias Colorrectales , Neoplasias Hepáticas , Tumores Neuroendocrinos , Humanos , Estudios Retrospectivos , Neoplasias Colorrectales/patología , Tumores Neuroendocrinos/cirugía , Neoplasias Hepáticas/secundario , Pronóstico , Hepatectomía
6.
Eur J Surg Oncol ; 48(5): 1104-1109, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34895970

RESUMEN

BACKGROUND: This study aimed to describe the treatment of metachronous colorectal cancer metastases in a recent population-based cohort. METHOD: Patients with stage I-III colorectal cancer (CRC), diagnosed between January 1st and June 30th, 2015 who were surgically treated with curative intent were selected from the Netherlands Cancer Registry. Follow-up was at least 3 years after diagnosis of the primary tumour. Treatment of metachronous metastases was categorized into local treatment, systemic treatment, and best supportive care. Overall survival was estimated using Kaplan-Meier method. RESULTS: Out of 5412 patients, 782 (14%) developed metachronous metastases, of whom 393 (50%) underwent local treatment (LT) with or without systemic therapy, 30% of patients underwent only systemic therapy (ST) and 19% only best supportive care (BSC). The most common metastatic site was the liver (51%) followed by lungs (33%) and peritoneum (22%). LT rates were 69%, 66%, and 44% for liver-only, lung-only and, peritoneal-only metastases respectively. Patients receiving LT and ST were significantly younger than patients receiving LT alone, while patients receiving BSC were significantly older than the other groups (p < 0.001). Patients with liver-only or lung-only metastases had a 3-year OS of 50.2% (43.3-56.7 95% CI) and 61.5% (50.7-70.6 95% CI) respectively. Patients with peritoneal-only disease had a lower 3-year OS, 18.1% (10.1-28.0 95% CI). CONCLUSION: Patients with metastases confined to the liver and lung have the highest rates of local treatment for metachronous metastatic colorectal cancer. The number of patients who underwent local treatment is higher than reported in previous Dutch and international studies.


Asunto(s)
Neoplasias del Colon , Neoplasias Colorrectales , Neoplasias Hepáticas , Neoplasias Pulmonares , Neoplasias del Recto , Neoplasias Colorrectales/patología , Humanos , Neoplasias Hepáticas/secundario , Neoplasias Pulmonares/secundario , Neoplasias Pulmonares/terapia , Países Bajos/epidemiología , Pronóstico
7.
Gene Ther ; 17(2): 272-80, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19865181

RESUMEN

The clinical application of self-inactivating (SIN) retroviral vectors has been hampered by the lack of reliable and efficient vector production technologies. To enable production of SIN gamma-retroviral vectors from stable producer clones, a new PG13-based packaging cell, known as PG368, was developed. Viral vector expression constructs can be reliably inserted at a predefined genomic locus of PG368 packaging cells by an Flp-recombinase-mediated targeted cassette exchange (RMCE) reaction. A new, carefully designed vector-targeting construct, pEMTAR-1, eliminated the co-packaging of the selectable marker gene used for the identification of successful recombination at the predefined genomic locus and thus, improved the safety of the production system. Selected clones produced vector supernatants at consistent titers. The targeted insertion of therapeutically relevant SIN vectors for chronic granulomatous disease and X-linked severe combined immunodeficiency into PG368 cells results in stable titers within the range necessary for clinical application. The production of retroviral SIN vectors from stable clinical-grade producer cells is feasible and will contribute to the safe production and application of SIN gamma-retroviral vectors for clinical trials.


Asunto(s)
ADN Nucleotidiltransferasas , Técnicas de Transferencia de Gen , Vectores Genéticos , Retroviridae/genética , Línea Celular , Estudios de Factibilidad , Marcación de Gen , Terapia Genética/métodos , Enfermedad Granulomatosa Crónica/terapia , Humanos , Inmunodeficiencia Combinada Grave/terapia
8.
J Mol Biol ; 264(5): 1044-57, 1996 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-9000629

RESUMEN

Thioredoxin exists in all organisms and is responsible for the hydrogen transfer to important enzymes for ribonucleotide reduction and the reduction of methionine sulphoxide and sulphate. Thioredoxins have also been shown to regulate enzyme activity in plants and are also involved in the regulation of transcription factors and several other regulatory activities. Thioredoxin is reduced by the flavoenzyme thioredoxin reductase using NADPH. We have now determined the first structure of a eukaryotic thioredoxin reductase, from the plant Arabidopsis thaliana, at 2.5 A resolution. The dimeric A. thaliana thioredoxin reductase is structurally similar to that of the Escherichia coli enzyme, and most differences occur in the loops. Because the plant and E. coli enzymes have the same architecture, with the same dimeric structure and the same position of the redox active disulphide bond, a similar mechanism that involves very large domain rotations is likely for the two enzymes. The subunit is divided into two domains, one that binds FAD and one that binds NADPH. The relative positions of the domains in A. thaliana thioredoxin reductase differ from those of the E. coli reductase. When the FAD domains are superimposed, the NADPH domain of A. thaliana thioredoxin reductase must be rotated by 8 degrees to superimpose on the corresponding domain of the E. coli enzyme. The domain rotation we now observe is much smaller than necessary for the thioredoxin reduction cycle.


Asunto(s)
Arabidopsis/enzimología , Reductasa de Tiorredoxina-Disulfuro/química , Secuencia de Aminoácidos , Arabidopsis/genética , Sitios de Unión , Cristalografía por Rayos X , Escherichia coli/enzimología , Escherichia coli/genética , Flavina-Adenina Dinucleótido/metabolismo , Modelos Moleculares , Datos de Secuencia Molecular , Estructura Molecular , NADP/metabolismo , Conformación Proteica , Homología de Secuencia de Aminoácido , Especificidad de la Especie , Reductasa de Tiorredoxina-Disulfuro/genética , Reductasa de Tiorredoxina-Disulfuro/metabolismo
9.
J Mol Biol ; 235(4): 1357-63, 1994 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-8308900

RESUMEN

Using a clone characterized in the course of a random sequencing programme of Arabidopsis thaliana, two cDNAs encoding plant type cytosolic NADPH-dependent thioredoxin reductase (NTR) have been isolated. Their sequence homology with Escherichia coli NRT (the only thioredoxin reductase of known primary structure) is about 45%. In addition, analysis of the sequence of the encoded polypeptide (333 amino acids) reveals that several motifs are conserved in the FAD, central and NADPH binding domains, suggesting a similar folding of the protein. Definitive proof that the clone ATTHIREDB indeed encodes NTR was obtained by expressing the recombinant protein in E. coli cells. It was observed that plant type NTR was strongly overproduced (about 10 mg homogeneous protein could be purified per liter of culture). The recombinant enzyme is homodimeric, each subunit containing an FAD prosthetic group. Recombinant plant type NTR is as effective as E. coli NTR in the DTNB (5,5'-dithiobis nitrobenzoic acid) reduction reaction, but its affinity for thioredoxin substrates was strikingly different. These results are discussed in relation to the primary structures of NADPH thioredoxin reductases.


Asunto(s)
Arabidopsis/enzimología , Reductasa de Tiorredoxina-Disulfuro/genética , Secuencia de Aminoácidos , Clonación Molecular , Electroforesis en Gel de Poliacrilamida , Escherichia coli , Datos de Secuencia Molecular , NADP/metabolismo , Filogenia , Proteínas Recombinantes/biosíntesis , Homología de Secuencia de Aminoácido , Reductasa de Tiorredoxina-Disulfuro/biosíntesis , Reductasa de Tiorredoxina-Disulfuro/clasificación
10.
Protein Sci ; 8(1): 65-74, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10210184

RESUMEN

The thioredoxin action upon the 2-oxoacid dehydrogenase complexes is investigated by using different thioredoxins, both wild-type and mutated. The attacking cysteine residue of thioredoxin is established to be essential for the thioredoxin-dependent activation of the complexes. Mutation of the buried cysteine residue to serine is not crucial for the activation, but prevents inhibition of the complexes, exhibited by the Clamydomonas reinhardtii thioredoxin m disulfide. Site-directed mutagenesis of D26, W31, F/W12, and Y/A70 (the Escherichia coli thioredoxin numbering is employed for all the thioredoxins studied) indicates that both the active site and remote residues of thioredoxin are involved in its interplay with the 2-oxoacid dehydrogenase complexes. Sequences of 11 thioredoxin species tested biochemically are aligned. The thioredoxin residues at the contact between the alpha3/3(10) and alpha1 helices, the length of the alpha1 helix and the charges in the alpha2-beta3 and beta4-beta5 linkers are found to correlate with the protein influence on the 2-oxoacid dehydrogenase complexes (the secondary structural elements of thioredoxin are defined according to Eklund H et al., 1991, Proteins 11:13-28). The distribution of the charges on the surface of the thioredoxin molecules is analyzed. The analysis reveals the species specific polarization of the thioredoxin active site surroundings, which corresponds to the efficiency of the thioredoxin interplay with the 2-oxoacid dehydrogenase systems. The most effective mitochondrial thioredoxin is characterized by the strongest polarization of this area and the highest value of the electrostatic dipole vector of the molecule. Not only the magnitude, but also the orientation of the dipole vector show correlation with the thioredoxin action. The dipole direction is found to be significantly influenced by the charges of the residues 13/14, 51, and 83/85, which distinguish the activating and inhibiting thioredoxin disulfides.


Asunto(s)
Cetona Oxidorreductasas/metabolismo , Complejos Multienzimáticos/metabolismo , Tiorredoxinas/metabolismo , 3-Metil-2-Oxobutanoato Deshidrogenasa (Lipoamida) , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cartilla de ADN , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Unión Proteica , Estructura Secundaria de Proteína , Homología de Secuencia de Aminoácido , Electricidad Estática , Tiorredoxinas/química , Tiorredoxinas/genética
11.
Gene ; 240(2): 307-16, 1999 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-10580150

RESUMEN

Screening of cDNA libraries at low stringency and complete sequencing of EST clones with homology to thioredoxins allowed us to characterize five new prokaryotic type Arabidopsis thaliana thioredoxins. All present N-terminal extensions with characteristics of transit peptides. Four are clustered in a phylogenetic tree with the chloroplastic thioredoxin m from red and green algae and higher plants, and their transit peptides have typical characteristics of chloroplastic transit peptides. One is clearly divergent and defines a new prokaryotic thioredoxin type that we have named thioredoxin x. Its transit peptide sequence presents characteristics of both chloroplastic and mitochondrial transit peptides. The five corresponding genes are expressed at different levels, but mostly in green tissues and in in-vitro cultivated cells.


Asunto(s)
Arabidopsis/genética , Genoma de Planta , Tiorredoxinas/genética , Secuencia de Aminoácidos , Arabidopsis/química , Southern Blotting , ADN Complementario/química , ADN Complementario/genética , ADN de Plantas/análisis , ADN de Plantas/genética , Bases de Datos Factuales , Etiquetas de Secuencia Expresada , Regulación de la Expresión Génica de las Plantas , Biblioteca de Genes , Datos de Secuencia Molecular , Filogenia , Células Procariotas/metabolismo , Isoformas de Proteínas/genética , ARN de Planta/genética , ARN de Planta/metabolismo , Alineación de Secuencia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Distribución Tisular
12.
Cell Stress Chaperones ; 6(3): 201-8, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11599561

RESUMEN

The Arabidopsis genome contains at least 18 genes encoding members of the 70-kilodalton heat shock protein (Hsp70) family, 14 in the DnaK subfamily and 4 in the Hsp110/SSE subfamily. While the Hsp70s are highly conserved, a phylogenetic analysis including all members of this family in Arabidopsis and in yeast indicates the homology of Hsp70s in the subgroups, such as those predicted to localize in the same subcellular compartment and those similar to the mammalian Hsp110 and Grp170. Gene structure and genome organization suggest duplication in the origin of some genes. The Arabidopsis hsp70s exhibit distinct expression profiles; representative genes of the subgroups are expressed at relatively high levels during specific developmental stages and under thermal stress.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas de Escherichia coli , Proteínas HSP70 de Choque Térmico/genética , Arabidopsis/fisiología , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Mapeo Cromosómico , Regulación de la Expresión Génica de las Plantas/fisiología , Genes de Plantas , Genoma de Planta , Proteínas HSP70 de Choque Térmico/química , Proteínas HSP70 de Choque Térmico/clasificación , Proteínas HSP70 de Choque Térmico/metabolismo , Filogenia , Estructura Terciaria de Proteína
13.
AJNR Am J Neuroradiol ; 17(4): 693-6, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8730189

RESUMEN

The management of extracranial carotid or vertebral artery pseudoaneurysms is controversial. Although some of these lesions resolve spontaneously, many clinicians opt to treat them with trapping procedures that result in vessel sacrifice. We describe two cases in which an intravascular stent was used to obliterate an aneurysm of the extracranial vertebral artery and the internal carotid artery, respectively, while maintaining the patency of the parent vessel. The technique, which has been successful in experimental animal models, shows promise for application in humans.


Asunto(s)
Aneurisma Falso/terapia , Enfermedades de las Arterias Carótidas/terapia , Stents , Arteria Vertebral , Aneurisma Falso/diagnóstico por imagen , Angiografía de Substracción Digital , Animales , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Arteria Carótida Interna/diagnóstico por imagen , Modelos Animales de Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Arteria Vertebral/diagnóstico por imagen
14.
Neurosurgery ; 26(3): 537-9, 1990 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-2320224

RESUMEN

Management of patients harboring infectious intracranial aneurysms remains controversial because of the technical problems associated with the obliteration of these lesions as well as their frequent regression during antibiotic therapy. A case of a ruptured bacterial aneurysm of the distal middle cerebral artery in which a segment of the artery was found to be inflamed and necrotic is presented. The ruptured portion of the sac was clipped, leaving a small tag of aneurysmal tissue. Five days later, this tag was found to have expanded into a second aneurysm. This second lesion resolved with antibiotic therapy. Because of the responsiveness of infected cerebral arteries to the appropriate antibiotics, a less than radical surgical tactic may be a successful alternative to excision of the diseased arterial segment followed by distal revascularization in treating these lesions.


Asunto(s)
Aneurisma Infectado/cirugía , Antibacterianos/uso terapéutico , Aneurisma Infectado/diagnóstico por imagen , Aneurisma Infectado/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Recurrencia
15.
Neurosurgery ; 25(2): 270-5, 1989 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2505157

RESUMEN

Microvascular Doppler recordings were taken from the nidus and draining system of a dural spinal cord arteriovenous malformation during operative treatment. Doppler signals readily showed the direction of blood flow in the draining vein and the hemodynamic effects of surgical maneuvers. Recording during alterations of mean arterial blood pressure and partial carbon dioxide pressure (pCO2) demonstrated lack of autoregulation and impaired CO2 reactivity in the AVM nidus. Microvascular Doppler techniques provide useful intraoperative assessment of the hemodynamics of arteriovenous malformations of the spinal cord.


Asunto(s)
Malformaciones Arteriovenosas/cirugía , Médula Espinal/irrigación sanguínea , Ultrasonografía , Malformaciones Arteriovenosas/fisiopatología , Velocidad del Flujo Sanguíneo , Presión Sanguínea , Dióxido de Carbono , Hemodinámica , Humanos , Periodo Intraoperatorio , Masculino , Microcirculación , Persona de Mediana Edad , Presión Parcial , Pulso Arterial
16.
Neurosurgery ; 22(3): 503-9, 1988 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3258962

RESUMEN

Catastrophic hyperemic states are known complications after the treatment of certain types of intracranial arteriovenous malformations (AVMs). A case is presented in which a large AVM was preoperatively embolized and later resected. There was clear intra- and postoperative evidence of edema and hemorrhage, which resulted in a fatal outcome. Regional cerebral blood flow (rCBF) data from this patient obtained with single photon emission computed tomography (SPECT) both before and after embolization were compared with data from four patients with similar size supratentorial AVMs treated and studied in a similar protocol who did not develop perfusion breakthrough. Pretreatment hemispheric rCBF was significantly reduced in this patient's ipsilateral hemisphere (50 ml/100 g/min) compared to the control group mean (83 +/- 9.5 ml/100 g/min). A similar relative depression was found in the contralateral hemisphere. After therapeutic embolization, the ipsilateral rCBF increased by 33 ml/100 g/min and the contralateral hemispheric rCBF increased by 30 ml/100 g/min; this embolization-induced increase in rCBF was significantly higher than in the control group. Acetazolamide, known to increase rCBF in normal tissue by 35 +/- 3%, resulted in a 56% augmentation of ipsilateral hemispheric flow before embolization in the reported patient vs. a 22 +/- 10% increase for the control group. Postembolization, this hyperresponsiveness to acetazolamide remained unchanged. It is possible that these hemodynamic derangements may indicate a dissociation between the vasoconstrictive and vasodilatory reactivity in chronically hypoperfused territories adjacent to AVMs such that pharmacological or metabolic stimuli may induce further vasodilation, but sudden redistribution of large volumes of flow will not promote protective vasoconstriction.


Asunto(s)
Presión Sanguínea , Edema Encefálico/etiología , Hemorragia Cerebral/etiología , Circulación Cerebrovascular , Malformaciones Arteriovenosas Intracraneales/terapia , Complicaciones Posoperatorias , Anciano , Angiografía Cerebral , Embolización Terapéutica , Hemodinámica , Humanos , Malformaciones Arteriovenosas Intracraneales/fisiopatología , Malformaciones Arteriovenosas Intracraneales/cirugía , Masculino , Valores de Referencia , Tomografía Computarizada de Emisión , Tomografía Computarizada por Rayos X
17.
Neurosurgery ; 34(1): 22-8; discussion 28-9, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8121566

RESUMEN

Temporary occlusion of intracranial arteries has emerged as a valuable technical adjunct in the management of intracranial aneurysms. The current study considered 121 patients (from a group of 234 consecutive aneurysm patients treated during a 2-yr period) who underwent elective temporary arterial occlusion. Twenty-one patients were excluded from further study because of an intraoperative rupture of an aneurysm, the elective sacrifice of afferent or efferent vessels, or the performance of an extracranial-intracranial arterial bypass graft; the remaining 100 patients underwent elective temporary occlusion under a standard neuroanesthetic regimen, including etomidate-induced burst suppression, normotension, normovolemia, and normothermia. In the postoperative period, radiographic evidence of ischemic brain injury in the distribution of the arteries occluded was selected as the end point for the failure of occlusion tolerance. The parameters evaluated with respect to this end point included the duration and nature of the temporary arterial occlusion, the number of the occlusive episodes, the specific vascular territory occluded, patient age, neurological status, presence of subarachnoid hemorrhage, vasospasm, and aneurysm size. Several parameters were found to be related to the postoperative development of ischemic injury. Patients more than 61 years of age and those in poor neurological condition (Hunt and Hess Grades III to IV) did not tolerate temporary occlusion as well as patients who were younger and in better condition. Patients occluded for less than 14 minutes routinely tolerated the iatrogenic ischemia; the 95% confidence level for the toleration of occlusion without the development of infarction occurred at 19 minutes. All patients occluded for more than 31 minutes had both clinical and radiographic evidence of cerebral infarction.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Isquemia Encefálica/diagnóstico por imagen , Aneurisma Intracraneal/cirugía , Microcirugia/métodos , Complicaciones Posoperatorias/diagnóstico por imagen , Adulto , Anestesia General , Aneurisma Roto/diagnóstico por imagen , Aneurisma Roto/cirugía , Isquemia Encefálica/cirugía , Angiografía Cerebral , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/cirugía , Etomidato , Femenino , Estudios de Seguimiento , Humanos , Aneurisma Intracraneal/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Examen Neurológico , Complicaciones Posoperatorias/cirugía , Reoperación , Factores de Riesgo , Hemorragia Subaracnoidea/diagnóstico por imagen , Hemorragia Subaracnoidea/cirugía , Tomografía Computarizada por Rayos X
18.
J Neurosurg ; 76(6): 961-6, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1588430

RESUMEN

Although severe hypovolemia can lead to hypotension and neurological decline, many patients with neurosurgical disorders experience a significant hypovolemia while autonomic compensatory mechanisms maintain a normal blood pressure. To assess the effects of normotensive hypovolemia upon cerebral hemodynamics, transcranial Doppler ultrasound monitoring of 13 healthy volunteers was performed during graded lower-body negative pressure of up to -50 mm Hg, an accepted laboratory model for reproducing the physiological effects of hypovolemia. Middle cerebral artery flow velocity declined by 16% +/- 4% (mean +/- standard error of the mean) and the ratio between transcranial Doppler ultrasound pulsatility and systemic pulsatility rose 22% +/- 8%, suggesting cerebral small-vessel vasoconstriction in response to the sympathetic activation unmasked by lower-body negative pressure. This vasoconstriction may interfere with the autoregulatory response to a sudden fall in blood pressure, and may explain the common observation of neurological deficit during hypovolemia even with a normal blood pressure.


Asunto(s)
Volumen Sanguíneo/fisiología , Encéfalo/fisiología , Circulación Cerebrovascular , Presión Negativa de la Región Corporal Inferior , Adulto , Presión Sanguínea , Ecoencefalografía , Hemodinámica , Humanos , Masculino , Flujo Pulsátil
19.
J Neurosurg ; 74(2): 263-9, 1991 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1988597

RESUMEN

The effects of etomidate, a nonbarbiturate cerebral metabolic depressant, on cerebral metabolism and blood flow were studied in 29 dogs during cerebral hypoperfusion. Three groups of animals were studied during a 45-minute normotensive and a 30-minute hypotensive period: 10 control animals without etomidate, 11 animals receiving a 0.1-mg/kg etomidate bolus followed by an infusion of 0.05 mg/kg/min etomidate (low-dose group), and eight animals receiving doses of etomidate sufficient to suppress electroencephalographic bursts (high-dose group). The mean arterial pressure fell to similar levels (p less than 0.05) during hypotension in all three groups (40 +/- 5, 38 +/- 3, and 27 +/- 6 mm Hg, respectively). The mean cerebral oxygen extraction fraction rose (p less than 0.05) from 0.23 +/- 0.02 to 0.55 +/- 0.08 in the five control animals tested and from 0.33 +/- 0.02 to 0.53 +/- 0.02 in the seven animals tested in the low-dose group, but did not increase (p greater than 0.05) in the four animals tested in the high-dose group (0.24 +/- 0.03 to 0.23 +/- 0.05). Mean cerebral blood flow levels decreased in all groups during hypotension (p less than 0.05): 42 +/- 3 to 21 +/- 4 ml/100 gm/min (52% +/- 12% decrease) in the five animals tested in the control group, 60 +/- 8 to 24 +/- 6 ml/100 gm/min (56% +/- 13% decrease) in the four animals tested in the low-dose group, and 55 +/- 8 to 22 +/- 3 ml/100 gm/min (60% +/- 4% decrease) in the four animals tested in the high-dose group. In summary, the cerebral oxygen extraction fraction increased in the control animals and low-dose recipients during hypotension, suggesting the presence of threatened cerebral tissue. In contrast, the cerebral oxygen extraction did not change during hypotension when high-dose etomidate was administered. It is concluded that high-dose etomidate may preserve the cerebral metabolic state during hypotension in the present model.


Asunto(s)
Encéfalo/metabolismo , Circulación Cerebrovascular/efectos de los fármacos , Etomidato/farmacología , Hipotensión/inducido químicamente , Animales , Arterias , Glucemia/análisis , Presión Sanguínea , Perros , Gases/sangre , Frecuencia Cardíaca , Hipotensión/metabolismo , Hipotensión/fisiopatología , Lactatos/sangre , Ácido Láctico , Consumo de Oxígeno
20.
Surg Neurol ; 34(3): 169-72, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2385825

RESUMEN

We report a case of delayed onset of ultimately permanent oculomotor nerve palsy following a focal aneurysmal hemorrhage into the adjacent interpeduncular cistern. Operative inspection revealed no direct nerve compression by the aneurysmal fundus. Third cranial neuropathies following subarachnoid hemorrhage can occur independently of direct aneurysmal mechanical compression.


Asunto(s)
Hematoma/complicaciones , Enfermedades del Nervio Oculomotor/etiología , Hemorragia Subaracnoidea/complicaciones , Anciano , Femenino , Hematoma/cirugía , Humanos , Hemorragia Subaracnoidea/cirugía
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