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1.
Sci Rep ; 6: 26830, 2016 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-27225311

RESUMEN

Long-term and reversible changes in body weight are typical of seasonal animals. Thyroid hormone (TH) and retinoic acid (RA) within the tanycytes and ependymal cells of the hypothalamus have been implicated in the photoperiodic response. We investigated signalling downstream of RA and how this links to the control of body weight and food intake in photoperiodic F344 rats. Chemerin, an inflammatory chemokine, with a known role in energy metabolism, was identified as a target of RA. Gene expression of chemerin (Rarres2) and its receptors were localised within the tanycytes and ependymal cells, with higher expression under long (LD) versus short (SD) photoperiod, pointing to a physiological role. The SD to LD transition (increased food intake) was mimicked by 2 weeks of ICV infusion of chemerin into rats. Chemerin also increased expression of the cytoskeletal protein vimentin, implicating hypothalamic remodelling in this response. By contrast, acute ICV bolus injection of chemerin on a 12 h:12 h photoperiod inhibited food intake and decreased body weight with associated changes in hypothalamic neuropeptides involved in growth and feeding after 24 hr. We describe the hypothalamic ventricular zone as a key site of neuroendocrine regulation, where the inflammatory signal, chemerin, links TH and RA signaling to hypothalamic remodeling.


Asunto(s)
Quimiocinas/fisiología , Metabolismo Energético/fisiología , Hipotálamo/metabolismo , Péptidos y Proteínas de Señalización Intercelular/fisiología , Fotoperiodo , Animales , Peso Corporal/efectos de los fármacos , Quimiocinas/administración & dosificación , Quimiocinas/farmacología , Ingestión de Alimentos/efectos de los fármacos , Metabolismo Energético/efectos de los fármacos , Epéndimo/citología , Epéndimo/metabolismo , Células Ependimogliales/metabolismo , Humanos , Hipotálamo/citología , Hipotálamo/efectos de los fármacos , Inyecciones Intraventriculares , Péptidos y Proteínas de Señalización Intercelular/administración & dosificación , Péptidos y Proteínas de Señalización Intercelular/farmacología , Masculino , Plasticidad Neuronal/efectos de los fármacos , Distribución Aleatoria , Ratas , Ratas Endogámicas F344 , Ratas Sprague-Dawley , Receptores de Quimiocina/análisis , Receptores de Quimiocina/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Hormonas Tiroideas/fisiología
2.
Eur J Radiol ; 82(8): e350-5, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23522746

RESUMEN

PURPOSE: To test the efficacy of internally CO2-cooled radiofrequency (RF) ablation in vivo and to compare its effectiveness to a standard water-cooled RF probe and to a gas-cooled microwave (MW) device. METHOD AND MATERIALS: 49 ablations were performed on 15 pigs under general anesthesia using 15G monopolar CO2-cooled RF applicators, 17G monopolar water-cooled RF applicators and 15G internally CO2-cooled microwave devices. The power of the MW device was 45W, the current of the gas-cooled RF device was 1200-1600mA. At the water-cooled RF probe, maximum power of 200W was set. Ablation time was 15min. The short and long axes of the ablation zone were measured. Histological analyses and NADH-staining were performed. The diameters and the ablation volumes were compared using an analysis of variance. RESULTS: No spots of untreated tissue were observed close to the cooled needle track in any of the ablation zones. The largest short axis diameter was 3.4±0.5cm achieved with the gas-cooled monopolar applicator. With the water-cooled applicators, short axis diameter was significantly smaller, reaching 2.5±0.4cm. Gas-cooled MW probes achieved 2.9±1.0cm. The largest ablation volume was 31.5±12ml (gas-cooled RF), and the smallest was 12.7±4ml (water-cooled RF). Short/long axis ratio was largest for gas-cooled RF probes with 0.73±0.08 versus 0.64±0.04 for the water-cooled probes and 0.49±0.25 for the microwave applicator. CONCLUSION: Gas-cooled RF applicators may have a higher potential for effective destruction of liver lesions than comparable water-cooled RF systems, and may be an alternative to standard RF and MW ablation devices.


Asunto(s)
Ablación por Catéter/instrumentación , Hepatectomía/instrumentación , Hipertermia Inducida/instrumentación , Hígado/patología , Hígado/cirugía , Microondas/uso terapéutico , Animales , Diseño de Equipo , Análisis de Falla de Equipo , Femenino , Gases/uso terapéutico , Humanos , Masculino , Porcinos , Resultado del Tratamiento
3.
Glia ; 59(11): 1695-705, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21769945

RESUMEN

The objective of this study is to investigate the impact of photoperiod on the temporal and spatial expression of genes involved in glucose metabolism in the brain of the seasonal mammal Phodopus sungorus (Siberian hamster). In situ hybridization was performed on brain sections obtained from male hamsters held in long photoperiod (high body weight and developed testes) or short photoperiod (reduced body weight with testicular regression). This analysis revealed upregulation in expression of genes involved in glycogen and glucose metabolism in short photoperiod and localized to the tanycyte layer of the third ventricle. On the basis of these data and a previously identified photoperiod-dependent increase in activity of neighboring hypothalamic neurons, we hypothesized that the observed expression changes may reflect alteration in either metabolic fuel or precursor neurotransmitter supply to surrounding neurons. Gene expression analysis was performed for genes involved in lactate and glutamate transport. This analysis showed that the gene for the lactate transporter MCT2 and glutamate transporter GLAST was decreased in the tanycyte layer in short photoperiod. Expression of mRNA for glutamine synthetase, the final enzyme in the synthesis of the neuronal neurotransmitter precursor, glutamine, was also decreased in short photoperiod. These data suggest a role for tanycytes in modulating glutamate concentrations and neurotransmitter supply in the hypothalamic environment.


Asunto(s)
Epéndimo/citología , Epéndimo/metabolismo , Glutamina/biosíntesis , Glucógeno/metabolismo , Glucólisis/fisiología , Hipotálamo/fisiología , Fotoperiodo , Animales , Núcleo Arqueado del Hipotálamo/citología , Núcleo Arqueado del Hipotálamo/metabolismo , Metabolismo de los Hidratos de Carbono/fisiología , Clonación Molecular , Cricetinae , ADN Complementario/biosíntesis , ADN Complementario/genética , Glucosa/metabolismo , Ácido Glutámico/metabolismo , Hipotálamo/citología , Hipotálamo/metabolismo , Hibridación in Situ , Ácido Láctico/metabolismo , Masculino , Microscopía Electrónica , Neurópilo/metabolismo , Phodopus , Ácido Pirúvico/metabolismo
4.
Acad Radiol ; 18(1): 89-96, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20926315

RESUMEN

RATIONALE AND OBJECTIVES: The aim of this study was to compare tumor changes in patients with hepatocellular carcinoma receiving sorafenib using evaluation criteria of the American Association for the Study of Liver Diseases (AASLD) and the European Association for the Study of the Liver (EASL) as opposed to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. MATERIALS AND METHODS: Twenty-five patients with inoperable hepatocellular carcinoma receiving oral sorafenib underwent magnetic resonance imaging at baseline and follow-up every 8 weeks (range, 2-19 weeks; mean, 7.6 weeks). Data were evaluated retrospectively. Survey time until progression ranged from 5 to 102 weeks (mean, 25.6 weeks), with a total of 54 target lesions being monitored. Additionally, evaluation of serum α-fetoprotein was performed at follow-up. RESULTS: The best response at follow-up using RECIST resulted in rates of 4% objective response (complete remission or partial remission), 24% (progressive disease), and 72% (stable disease). In contrast, AASLD and EASL criteria identified objective responses in 28% and 48%. Twenty percent of all patients classified as having progressive disease by RECIST were identified as having "pseudo"-progression due to extensive necrosis. Eleven percent of patients classified as having stable disease by RECIST were disclosed as essentially progressive. AASLD area and AASLD diameter disclosed 36% and 40% of patients as having partial remission, respectively, whereas EASL criteria discovered only 24%. There was no significant correlation between serum α-fetoprotein progression and AASLD, EASL, or RECIST evaluation criteria. CONCLUSIONS: Response monitoring via functional criteria such as AASLD or EASL criteria is likely to more accurately reflect vital tumor burden in hepatocellular carcinoma compared to RECIST.


Asunto(s)
Antineoplásicos/uso terapéutico , Bencenosulfonatos/uso terapéutico , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Piridinas/uso terapéutico , Adulto , Anciano , Antineoplásicos/sangre , Bencenosulfonatos/sangre , Carcinoma Hepatocelular/sangre , Carcinoma Hepatocelular/patología , Medios de Contraste , Femenino , Estudios de Seguimiento , Gadolinio DTPA , Humanos , Aumento de la Imagen/métodos , Hígado/efectos de los fármacos , Hígado/patología , Neoplasias Hepáticas/sangre , Neoplasias Hepáticas/patología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Necrosis , Niacinamida/análogos & derivados , Compuestos de Fenilurea , Piridinas/sangre , Estudios Retrospectivos , Sorafenib , Resultado del Tratamiento , Carga Tumoral/efectos de los fármacos , alfa-Fetoproteínas/efectos de los fármacos
5.
AJR Am J Roentgenol ; 194(1): 5-14, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20028898

RESUMEN

OBJECTIVE: The purpose of this article is to illustrate the characteristic changes induced in different tumor types by the multitargeted tyrosine kinase inhibitor sorafenib. CONCLUSION: Sorafenib reduces tumor perfusion and thereby induces necrosis and often hemorrhage. Malignant tumors treated with sorafenib undergo both morphologic and functional changes; however, the morphologic changes are less frequent and inadequate for early evaluation of response. Therefore, imaging tools accurately assessing hemorrhage and decrease in tumor perfusion with subsequent necrosis should be the mainstay in monitoring targeted therapy agents.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/tratamiento farmacológico , Bencenosulfonatos/uso terapéutico , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma de Células Renales/tratamiento farmacológico , Neoplasias Renales/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Neovascularización Patológica/tratamiento farmacológico , Feocromocitoma/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Piridinas/uso terapéutico , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Neoplasias de las Glándulas Suprarrenales/patología , Anciano , Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/patología , Carcinoma de Células Renales/diagnóstico por imagen , Carcinoma de Células Renales/patología , Medios de Contraste , Femenino , Humanos , Neoplasias Renales/diagnóstico por imagen , Neoplasias Renales/patología , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/patología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Niacinamida/análogos & derivados , Compuestos de Fenilurea , Feocromocitoma/diagnóstico por imagen , Feocromocitoma/patología , Sensibilidad y Especificidad , Sorafenib , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Ultrasonografía
6.
AJR Am J Roentgenol ; 193(4): W301-7, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19770299

RESUMEN

OBJECTIVE: The objective of our study was to evaluate signal changes of advanced hepatocellular carcinoma in diffusion-weighted MRI in the early-response monitoring of oral therapy with the multikinase inhibitor sorafenib. CONCLUSION: Hepatocellular carcinoma lesions exhibit characteristic but unusual apparent diffusion coefficient (ADC) changes during sorafenib therapy, consisting of early decrease in ADC after therapy onset followed by a reincrease. The ADC changes seem to reflect the underlying pathophysiologic mechanisms in tumor necrosis (most probably hemorrhagic) induced by this novel targeted agent early after therapy onset and may indicate tumor reactivation in the later follow-up period.


Asunto(s)
Bencenosulfonatos/administración & dosificación , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/tratamiento farmacológico , Imagen de Difusión por Resonancia Magnética/métodos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/tratamiento farmacológico , Piridinas/administración & dosificación , Administración Oral , Anciano , Anciano de 80 o más Años , Antineoplásicos/administración & dosificación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Niacinamida/análogos & derivados , Compuestos de Fenilurea , Proyectos Piloto , Pronóstico , Sensibilidad y Especificidad , Sorafenib , Resultado del Tratamiento
7.
BMC Cancer ; 9: 208, 2009 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-19558720

RESUMEN

BACKGROUND: New therapeutic principles in clinical oncology require the adjustment of response criteria to govern therapy decisions. For advanced hepatocellular carcinoma (HCC) a new era has recently begun by the approval of the multikinase inhibitor sorafenib. As a unique feature, HCC usually develops in a diseased liver and current imaging technologies employing classical response criteria have not been prospectively evaluated for this new treatment. METHODS: MRI signal patterns were assessed in 21 advanced HCC patients receiving sorafenib. MRI was performed at baseline and in short-term intervals thereafter. Signal changes under therapy on T1WI, T2WI and post-gadolinium images including necrosis volume and its ratio to the entire tumor volume were compared to baseline imaging. To assess the association between the categorical variables, Fisher's exact tests were applied for a statistical analysis. Survey time ranged from 2-65 weeks, and a total of 39 target lesions were evaluated. RESULTS: Signal abnormalities during sorafenib therapy were disclosed by T1WI and T2WI in 15/21 patients. The predominant tumor signal change was hyperintensity on both T1WI and T2WI. Interestingly, most patients developed MRI signal changes within 4 weeks of therapy; in contrast, two non-responders did not show any signal alteration at follow-up. Under therapy, 16/21 patients presented with new or progressive necrosis, whereas 7 patients achieved temporarily >75% tumor necrosis under sorafenib. Significantly associated MRI variables were increase in T1WI signal and tumor necrosis (p = 0.017) as well as increase of tumor necrosis with an elevated ratio of necrotic to vital tumor areas (p = 0.002). Remarkably, some (3/13) of the patients developing necrotic tumor areas showed a relevant (>20%) increase in tumor volume, which should be considered in the assessment of imaging studies. CONCLUSION: As sorafenib induces early intralesional necrosis with profound changes in T1WI/T2WI MRI signal intensities and measurable necrotic tumor areas in most HCC patients, early MRI-based evaluation could pave the way for its rationale and cost-effective application.


Asunto(s)
Antineoplásicos/uso terapéutico , Bencenosulfonatos/uso terapéutico , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/tratamiento farmacológico , Imagen por Resonancia Magnética/métodos , Inhibidores de Proteínas Quinasas/uso terapéutico , Piridinas/uso terapéutico , Adulto , Anciano , Carcinoma Hepatocelular/patología , Femenino , Humanos , Hígado/patología , Neoplasias Hepáticas/patología , Masculino , Persona de Mediana Edad , Necrosis , Niacinamida/análogos & derivados , Compuestos de Fenilurea , Sorafenib , Resultado del Tratamiento
8.
Ann Surg Oncol ; 16(5): 1295-303, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19252950

RESUMEN

BACKGROUND: Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with significantly longer survival in patients with peritoneal carcinomatosis (PC). So far, no morphological imaging method has proven to accurately assess the intra-abdominal tumor spread. This study was designed to predict tumor load in patients with PC using dual-modality (18)FDG-PET/CT and to compare the results with those of PET and CT alone by correlating imaging findings with intraoperative staging. METHODS: Twenty-two patients with PC from gastrointestinal (n = 13), ovarian cancer (n = 8), and mesothelioma (n = 1) underwent contrast-enhanced (18)FDG-PET/CT before surgery and HIPEC. In a retrospective analysis PET, CT, and fused PET/CT were separately and blindly reviewed for the extent of peritoneal involvement using the Peritoneal Cancer Index (PCI). Imaging results were correlated with the intraoperative PCI using Pearson's correlation coefficient and linear regression analysis. RESULTS: There was a strong correlation between the PCI obtained with PET/CT and the surgical PCI with respect to the total score (r = 0.951) as well as in the regional analysis (small bowel, r = 0.838; other, r = 0.703). The correlation was slightly lower for CT alone (total score, r = 0.919; small bowel, r = 0.754; other, r = 0.666) and significantly lower (p = 0.002) for PET alone (total score, r = 0.793; small bowel, r = 0.553, other, 0.507). CONCLUSIONS: Contrast-enhanced CT is superior compared with PET alone to predict the extent of PC. In our patient group, the combination of both modalities (contrast enhanced PET/CT) yielded the best results and proved to be a useful tool for selecting candidates for peritonectomy and HIPEC.


Asunto(s)
Antineoplásicos/administración & dosificación , Neoplasias Peritoneales/diagnóstico por imagen , Neoplasias Peritoneales/terapia , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Adulto , Anciano , Quimioterapia del Cáncer por Perfusión Regional , Terapia Combinada , Femenino , Fluorodesoxiglucosa F18 , Humanos , Hipertermia Inducida , Infusiones Parenterales , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Selección de Paciente , Neoplasias Peritoneales/patología , Neoplasias Peritoneales/secundario , Valor Predictivo de las Pruebas , Radiofármacos , Procedimientos Quirúrgicos Operativos , Carga Tumoral
9.
Invest Radiol ; 40(11): 729-35, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16230906

RESUMEN

OBJECTIVE: We sought to examine high-intensity focused ultrasound (HIFU)-induced hyperthermia in the liver of a rat model to focally induce green-fluorescent protein (GFP). MATERIALS AND METHODS: A total of 25 Copenhagen rats were included in this study. Rats were divided into groups treated with an adenovirus coding for green fluorescent protein (GFP) under the control of a hsp70B promoter and a CMV promoter. Ad-CMV-GFP-treated rats served as positive control. Untreated controls only subjected to MRI +/- HIFU-treatment served to find out optimal power of HIFU in the target area of the liver. Temperature was noninvasively monitored by temperature sensitive magnetic resonance imaging (MRI). RESULTS: Rats treated with Ad-hsp70B-GFP demonstrated localized gene induction within the liver parenchyma, in good correlation with MRI and histology. Applying an acoustic power of 1.92 W a relatively uniform focal temperature up to 42 +/- 5 degrees C within the liver parenchyma could be documented. 3 x 10(9) plaque-forming units proved to account for a very homogeneous liver infection. Number of fluorescent cells in the region of hyperthermia was similar to the control group treated with Ad-CMV-GFP. CONCLUSION: Using the introduced parameters spatially controlled gene induction within a parenchymal organ such as the liver in rats using HIFU under control of MRI is feasible.


Asunto(s)
Regulación de la Expresión Génica , Proteínas HSP70 de Choque Térmico/genética , Respuesta al Choque Térmico/genética , Hepatocitos/metabolismo , Hipertermia Inducida/métodos , Hígado/diagnóstico por imagen , Adenoviridae/genética , Animales , Terapia Genética , Vectores Genéticos , Proteínas Fluorescentes Verdes , Proteínas HSP70 de Choque Térmico/metabolismo , Sustancias Luminiscentes , Imagen por Resonancia Magnética , Masculino , Microscopía Fluorescente , Modelos Animales , Regiones Promotoras Genéticas , Ratas , Ratas Endogámicas , Activación Transcripcional , Transgenes/fisiología , Ultrasonografía
10.
Radiology ; 232(2): 482-90, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15286318

RESUMEN

PURPOSE: To compare in vivo coagulation necrosis obtained with four radiofrequency (RF) ablation devices, to determine shape and reproducibility of induced coagulation by means of three-dimensional measurements of the ablation zone, and to achieve representations of the coagulated areas in three-dimensional spaces. MATERIALS AND METHODS: Four commercially available RF devices (perfusion, internally cooled cluster, and nine- and 12-tine expandable electrodes) that represent the most widely used systems on the market were tested. Sixteen in vivo ablation procedures were performed in porcine livers (four ablations for each RF system). After macroscopic and histopathologic analyses of 3-mm-thick liver sections, morphometric and volumetric findings in the central zone of white coagulation necrosis were assessed. Coagulation volume, diameter, length, and shape were determined digitally. After analysis of variance, measurements with each system were tested with the Tukey post hoc test. RESULTS: Mean coagulation volumes were 31.5 cm3 +/- 15.8 (SD) for the perfusion electrode, 20.5 cm3 +/- 2.6 for the cluster electrode, 16.2 cm3 +/- 7.3 for the 12-tine electrode, and 9.8 cm3 +/- 3.2 for the nine-tine electrode (P <.05, perfusion vs nine-tine electrode). No significant differences were observed regarding the mean short axis perpendicular to the needle shaft: 2.30 cm +/- 0.94, 3.04 cm +/- 0.26, 3.44 cm +/- 0.21, and 2.70 cm +/- 0.76, respectively. Variation coefficients were 0.50, 0.13, 0.45, and 0.33, respectively. CONCLUSION: Larger coagulation volumes were obtained with the perfusion and internally cooled cluster devices. More spherical volumes of ablation were achieved with the 12-tine and cluster electrodes. The former proved superior with regard to the short axis perpendicular to the needle shaft. The cluster and nine-tine electrode produced better reproducibility, which is suggestive of improved predictability of the extent of coagulation with these systems.


Asunto(s)
Hipertermia Inducida/instrumentación , Hígado/patología , Animales , Simulación por Computador , Daño del ADN , Electrodos , Diseño de Equipo , Procesamiento de Imagen Asistido por Computador , Imagenología Tridimensional , Masculino , Necrosis , Fotograbar , Porcinos , Evaluación de la Tecnología Biomédica
11.
Technol Cancer Res Treat ; 2(1): 13-8, 2003 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-12625749

RESUMEN

In the United States and Europe, colorectal cancer is the second leading cause of cancer-related deaths. It is well known that colorectal carcinomas may originate from preexisting adenomas. For the visualization of colorectal cancer and other pathologic changes such as polyps, two 3D methods (volume-rendering (VR) and surface-rendering (SR)) in MR colonography were compared in our study. MR colonography was carried out in 17 patients on a 1.5 T MR scanner using a 10 mmolar gadolinium water solution enema. Coronal as well as rotated VR and SR views were compared in order to examine the technical quality (TQ) of the visualization model and grade of confidence (GC) in the pathological findings. Colonoscopic findings revealed 8 colorectal carcinoma, 10 patients with polyps, 4 diverticular disease, and 2 with redundant bowel loops. Based on a total of 248 colonic segments for both visualization methods, volume rendering were significantly superior to surface rendering for both, TQ (p<0.0001) and GC (p<0.0001). Volume rendering and surface rendering were not dependent on individual colon segments (p=0.13 for TQ and p=0.18 for GC) or on image rotation (p=0.06 for TQ and p=0.062 for GC). It is also independent of the type of pathology (p=0.31 for TQ and p=0.42 for GC) and the reviewers (p=0.62 for TQ and p=0.88 for GC). This indicates, that for the purpose of interpreting the technical quality and pathological findings, volume rendering is superior to surface rendering in MR colonography. Volume rendering could be used as an 3D visualization tool, enabling MR colonography examinations to be completed sooner in cases where colon distension is sufficient, and it would also provide an overview of potential mass lesions.


Asunto(s)
Neoplasias Colorrectales/diagnóstico , Imagen por Resonancia Magnética/métodos , Anciano , Neoplasias Colorrectales/patología , Femenino , Humanos , Imagenología Tridimensional/métodos , Masculino
12.
Biomed Tech (Berl) ; 35(6): 139-44, 1990 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-2372568

RESUMEN

Electrical stimulation, which has long been known, has recently been complemented by electromagnetic stimulation. This method is based on the law of induction and employs coils in place of electrodes. The effect of this process is deduced from both the relationship between magnetic and electrical fields and the stimulating effect. A new type of stimulator has been developed from a resonant circuit, thus allowing nerves to be excited with low-frequency pulses up to fusion frequency.


Asunto(s)
Estimulación Eléctrica/instrumentación , Campos Electromagnéticos , Fenómenos Electromagnéticos , Animales , Encéfalo/fisiología , Conductividad Eléctrica , Terapia por Estimulación Eléctrica/instrumentación , Electrodiagnóstico/instrumentación , Diseño de Equipo , Humanos
14.
Eur Neurol ; 22(5): 367-70, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-6138256

RESUMEN

Chronic (12 days) administration of sulpiride (50 mg/kg, i.p.) in rats resulted in a significant (12%) increase in the glutamate contents of cerebrospinal fluid. Sulpiride had no effect on the GABA content of the brain areas investigated (frontal cortex, striatum, hippocampus and substantia nigra). Sulpiride is a neuroleptic drug which is believed to block especially the non-adenylate cyclase dopaminergic receptors which are supposed to be inhibitory axoaxonic receptors on glutamatergic corticostriatal terminals. The results are compatible with the hypothesis that glutamatergic hypofunction might be the primary defect in schizophrenia rather than hyperactivity of the dopamine synapses.


Asunto(s)
Cuerpo Estriado/efectos de los fármacos , Glutamatos/líquido cefalorraquídeo , Esquizofrenia/líquido cefalorraquídeo , Sulpirida/administración & dosificación , Animales , Cuerpo Estriado/metabolismo , Lóbulo Frontal/efectos de los fármacos , Lóbulo Frontal/metabolismo , Ácido Glutámico , Hipocampo/efectos de los fármacos , Hipocampo/metabolismo , Humanos , Masculino , Muridae , Receptores Dopaminérgicos/efectos de los fármacos , Sustancia Negra/efectos de los fármacos , Sustancia Negra/metabolismo
15.
Syst Appl Microbiol ; 4(4): 496-506, 1983.
Artículo en Inglés | MEDLINE | ID: mdl-23194807

RESUMEN

Twenty-two strains of endospore-forming sarcinae have been isolated from salt marsh soils. The isolates differ phenotypically from Sporosarcina ureae, the only species of the genus Sporosarcina which has been validly described, and are distinct from S. ureae in the composition of the cell walls of their vegetative cells. Lysine, found in the tetrapeptide of the murein of S. ureae, is replaced by ornithine in the new isolates. The interpeptide bridge consists of an aspartic acid residue instead of D-glutamylglycine as is found in S. ureae. The mol% G + C of the DNA of the new isolates is in the range of 40.1-40.9 (S. ureae 40.0-41.5). DNA hybridization studies revealed a high DNA-DNA homology within the new isolates but only a low relationship to S. ureae. The main menaquinone is of the MK-7 type as in S. ureae and other aerobic sporeformers. The spores of the new isolates are very similar to spores of S. ureae and Bacillus species in respect of their heat resistance, composition and ultrastructure. None of the new isolates grows on complex media unless supplemented with sodium, magnesium and chloride ions. Strains are slight halophiles as they grow best in the presence of 30 to 50 g NaCl/1 and 5 g MgCl(2)/l. The new isolates thus belong to a new species, for which the name Sporosarcina halophila is proposed. Strain DSM 2266 (= strain 3) is the type strain.

16.
Arch Psychiatr Nervenkr (1970) ; 232(1): 33-8, 1982.
Artículo en Alemán | MEDLINE | ID: mdl-6128966

RESUMEN

Phosphatidylcholine increases CNS concentrations of acetylcholine. In rats we investigated whether or not phosphatidylcholine also influences the neurotransmitters glutamate and GABA. In 17 rats 1.5 gram/kg Lethicon perorally was administered daily for 2 weeks, 15 rats served as controls. In tissue from frontal cortex, striatum, substantia nigra, cerebellar cortex no significant differences between treated and untreated animals were found in glutamate or GABA concentrations. A central nervous interaction between the cholinergic system and the neurotransmitters glutamate and GABA, therefore, could not be demonstrated after 2 weeks of phosphatidylcholine intake.


Asunto(s)
Encéfalo/efectos de los fármacos , Glutamatos/metabolismo , Fosfatidilcolinas/farmacología , Ácido gamma-Aminobutírico/metabolismo , Animales , Encéfalo/metabolismo , Corteza Cerebelosa/efectos de los fármacos , Cuerpo Estriado/efectos de los fármacos , Lóbulo Frontal/efectos de los fármacos , Ácido Glutámico , Masculino , Muridae , Sustancia Negra/efectos de los fármacos
17.
Arch Psychiatr Nervenkr (1970) ; 232(2): 183-9, 1982.
Artículo en Alemán | MEDLINE | ID: mdl-6130753

RESUMEN

The effect of chronic ethanol administration, 5 g/kg per day for 2 or 4 weeks, on the neurotransmitters glutamate and GABA was investigated in rats. An increase in GABA was found in the striatum, hippocampus, and substantia nigra, 8 or 12 h after the last ingestion of ethanol, this being masked by injection of barbiturate. In addition an increase of glutamate has been found in the examined brain areas. This is consistent with the known effect of ethanol on brain Dopa metabolism and release. Finally, the relevance of the results for the pathogenesis of withdrawal seizures and delirious states is discussed.


Asunto(s)
Consumo de Bebidas Alcohólicas , Encéfalo/efectos de los fármacos , Glutamatos/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Animales , Encéfalo/metabolismo , Cuerpo Estriado/efectos de los fármacos , Lóbulo Frontal/efectos de los fármacos , Ácido Glutámico , Hipocampo/efectos de los fármacos , Masculino , Muridae , Sustancia Negra/efectos de los fármacos
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