Asunto(s)
Encefalopatías , COVID-19 , Humanos , Angiografía por Resonancia Magnética/métodos , SARS-CoV-2RESUMEN
BACKGROUND AND PURPOSE: Recent concerns relating to tissue deposition of gadolinium are favoring the use of noncontrast MR imaging whenever possible. The purpose of this study was to assess the necessity of gadolinium contrast for follow-up MR imaging of untreated intracranial meningiomas. MATERIALS AND METHODS: One-hundred twenty-two patients (35 men, 87 women) with meningiomas who underwent brain MR imaging between May 2007 and May 2019 in our institution were included in this retrospective cohort study. We analyzed 132 meningiomas: 73 non-skull base (55%) versus 59 skull base (45%), 93 symptomatic (70%) versus 39 asymptomatic (30%). Fifty-nine meningiomas underwent an operation: 54 World Health Organization grade I (92%) and 5 World Health Organization grade II (8%). All meningiomas were segmented on T1 3D-gadolinium and 2D-T2WI. Agreement between T1 3D-gadolinium and 2D-T2WI segmentations was assessed by the intraclass correlation coefficient. RESULTS: The mean time between MR images was 1485 days (range, 760-3810 days). There was excellent agreement between T1 3D-gadolinium and T2WI segmentations (P < .001): mean tumor volume (T1 3D-gadolinium: 9012.15 [SD, 19,223.03] mm3; T2WI: 8528.45 [SD, 18,368.18 ] mm3; intraclass correlation coefficient = 0.996), surface area (intraclass correlation coefficient = 0.989), surface/volume ratio (intraclass correlation coefficient = 0.924), maximum 3D diameter (intraclass correlation coefficient = 0.986), maximum 2D diameter in the axial (intraclass correlation coefficient = 0.990), coronal (intraclass correlation coefficient = 0.982), and sagittal planes (intraclass correlation coefficient = 0.985), major axis length (intraclass correlation coefficient = 0.989), minor axis length (intraclass correlation coefficient = 0.992), and least axis length (intraclass correlation coefficient = 0.988). Tumor growth also showed good agreement (P < .001), estimated as a mean of 461.87 [SD, 2704.1] mm3/year on T1 3D-gadolinium and 556.64 [SD, 2624.02 ] mm3/year on T2WI. CONCLUSIONS: Our results show excellent agreement between the size and growth of meningiomas derived from T1 3D-gadolinium and 2D-T2WI, suggesting that the use of noncontrast MR imaging may be appropriate for the follow-up of untreated meningiomas, which would be cost-effective and avert risks associated with contrast media.
Asunto(s)
Neoplasias Meníngeas , Meningioma , Medios de Contraste , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Neoplasias Meníngeas/diagnóstico por imagen , Meningioma/diagnóstico por imagen , Estudios RetrospectivosRESUMEN
BACKGROUND AND PURPOSE: Early outcome prediction of postanoxic patients in a coma after cardiac arrest proves challenging. Current prognostication relies on multimodal testing, using clinical examination, electrophysiologic testing, biomarkers, and structural MR imaging. While this multimodal prognostication is accurate for predicting poor outcome (ie, death), it is not sensitive enough to identify good outcome (ie, consciousness recovery), thus leaving many patients with indeterminate prognosis. We specifically assessed whether resting-state fMRI provides prognostic information, notably in postanoxic patients in a coma with indeterminate prognosis early after cardiac arrest, specifically for good outcome. MATERIALS AND METHODS: We used resting-state fMRI in a prospective study to compare whole-brain functional connectivity between patients with good and poor outcomes, implementing support vector machine learning. Then, we automatically predicted coma outcome using resting-state fMRI and also compared the prediction based on resting-state fMRI with the outcome prediction based on DWI. RESULTS: Of 17 eligible patients who completed the study procedure (among 351 patients screened), 9 regained consciousness and 8 remained comatose. We found higher functional connectivity in patients recovering consciousness, with greater changes occurring within and between the occipitoparietal and temporofrontal regions. Coma outcome prognostication based on resting-state fMRI machine learning was very accurate, notably for identifying patients with good outcome (accuracy, 94.4%; area under the receiver operating curve, 0.94). Outcome predictors using resting-state fMRI performed significantly better (P < .05) than DWI (accuracy, 60.0%; area under the receiver operating curve, 0.63). CONCLUSIONS: Indeterminate prognosis might lead to major clinical uncertainty and significant variations in life-sustaining treatments. Resting-state fMRI might bridge the gap left in early prognostication of postanoxic patients in a coma by identifying those with both good and poor outcomes.
Asunto(s)
Coma/fisiopatología , Imagen por Resonancia Magnética/métodos , Recuperación de la Función/fisiología , Máquina de Vectores de Soporte , Adulto , Anciano , Encéfalo/fisiopatología , Coma/diagnóstico , Coma/etiología , Femenino , Paro Cardíaco/complicaciones , Humanos , Hipoxia/etiología , Masculino , Persona de Mediana Edad , Pronóstico , Estudios ProspectivosRESUMEN
Midlife obesity is a risk factor for cognitive decline and is associated with the earlier onset of Alzheimer's disease (AD). Diets high in saturated fat potentiate the onset of obesity, microglial activation, and neuroinflammation. Signaling deficiencies in the hypothalamic peptide orexin and/or orexin fiber loss are linked to neurodegeneration, cognitive impairment, and neuroinflammation. Prior studies show that orexin is neuroprotective, suppresses neuroinflammation, and that treatment with orexin improves cognitive processes in orexin/ataxin-3 (O/A3) mice, a transgenic mouse model of orexin neurodegeneration. Our overall hypothesis is that loss of orexin contributes to high fat diet (HFD)-induced hippocampal neuroinflammation and cognitive decline. To examine this, we tested male O/A3 mice (7-8 mo. of age) in a two-way active avoidance (TWAA) hippocampus-dependent memory task. We tested whether (1) orexin loss impaired cognitive function; (2) HFD worsened cognitive impairment; and (3) HFD increased microglial activation and neuroinflammation. O/A3 mice showed significant impairments in TWAA task learning vs. wild type (WT) mice (increased escapes pâ¯<â¯0.05, reduced avoidances pâ¯<â¯0.0001). Mice were then placed on HFD (45% total fat, 31.4% saturated fat) or remained on normal chow (NC; 4% total fat and 1% saturated fat), and TWAA was retested at 2 and 4â¯weeks. Learning impairment was evident at both 2 and 4â¯weeks in O/A3 mice fed HFD for following diet exposure vs. WT mice on normal chow or HFD (increased escapes, reduced avoidances pâ¯<â¯0.05). Additionally, O/A3 mice had increased gene expression of the microglial activation marker Iba-1 (measured via qRT-PCR, pâ¯<â¯0.001). Further characterization of the microglial immune response genes in hippocampal tissue revealed a significant increase in CX3 chemokine receptor 1 (CX3CR1), tumor necrosis factor-alpha (TNF-α) and the mitochondria-associated enzyme immune responsive gene-1 (Irg1). Collectively, our results indicate that orexin loss impairs memory, and that HFD accelerates hippocampus-dependent learning deficits and the onset of neuroinflammation.
Asunto(s)
Ataxina-3/fisiología , Disfunción Cognitiva/fisiopatología , Dieta Alta en Grasa , Encefalitis/fisiopatología , Obesidad/fisiopatología , Orexinas/fisiología , Animales , Ataxina-3/genética , Disfunción Cognitiva/etiología , Encefalitis/etiología , Hipocampo/fisiopatología , Masculino , Memoria/fisiología , Ratones Endogámicos C57BL , Ratones Transgénicos , Obesidad/complicaciones , Receptores de Orexina/metabolismo , Orexinas/genéticaRESUMEN
Attention deficit hyperactivity disorder (ADHD) is accompanied by resting-state alterations, including abnormal activity, connectivity and asymmetry of the default-mode network (DMN). Concurrently, recent studies suggested a link between ADHD and the presence of polymorphisms within the gene BAIAP2 (i.e., brain-specific angiogenesis inhibitor 1-associated protein 2), known to be differentially expressed in brain hemispheres. The clinical and neuroimaging correlates of this polymorphism are still unknown. We investigated the association between BAIAP2 polymorphisms and DMN functional connectivity (FC) asymmetry as well as behavioral measures in ADHD adults. Resting-state fMRI was acquired from 30 ADHD and 15 healthy adults. For each subject, rs7210438 and rs8079626 within the gene BAIAP2 were genotyped. ADHD severity, impulsiveness and anger were assessed for the ADHD group. Using multivariate analysis of variance, we found that genetic features do have an impact on DMN FC asymmetry. In particular, polymorphism rs8079626 affects medial frontal gyrus and inferior parietal lobule connectivity asymmetry, lower for AA than AG/GG carriers. Further, when combining FC asymmetry and the presence of the rs8079626 variant, we successfully predicted increased externalization of anger in ADHD. In conclusion, a complex interplay between genetic vulnerability and inter-hemispherical DMN FC asymmetry plays a role in emotion regulation in adult ADHD.
Asunto(s)
Ira/fisiología , Trastorno por Déficit de Atención con Hiperactividad/diagnóstico por imagen , Trastorno por Déficit de Atención con Hiperactividad/genética , Cerebro/diagnóstico por imagen , Cerebro/fisiología , Proteínas del Tejido Nervioso/genética , Adulto , Mapeo Encefálico/métodos , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Red Nerviosa/diagnóstico por imagen , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/fisiología , Corteza Prefrontal/diagnóstico por imagenRESUMEN
BACKROUND AND PURPOSE: Shoulder apprehension is defined as anxiety and resistance in patients with a history of anterior glenohumeral instability. It remains unclear whether shoulder apprehension is the result of true recurrent instability or a memorized subjective sensation. We tested whether visual presentation of apprehension videos modifies functional brain networks associated with motor resistance and anxiety. MATERIALS AND METHODS: This prospective study includes 15 consecutive right-handed male patients with shoulder apprehension (9 with right shoulder apprehension, 6 with left shoulder apprehension; 27.5 ± 6.4 years) and 10 healthy male right-handed age-matched control participants (29.0 ± 4.7 years). Multimodal MR imaging included 1) functional connectivity tensorial independent component analysis, 2) task-related general linear model analysis during visual stimulation of movies showing typical apprehension movements vs control videos, 3) voxel-based morphometry analysis of GM, and 4) tract-based spatial statistics analysis of WM. RESULTS: Patients with shoulder apprehension had significant (P < .05 corrected) increase in task-correlated functional connectivity, notably in the bilateral primary sensory-motor area and dorsolateral prefrontal cortex and, to a lesser degree, the bilateral dorsomedial prefrontal cortex, anterior insula, and dorsal anterior cingulate cortex (+148% right, +144% left). Anticorrelated functional connectivity decreased in the higher-level visual and parietal areas (-185%). There were no potentially confounding structural changes in GM or WM. CONCLUSIONS: Shoulder apprehension induces specific reorganization in apprehension-related functional connectivity of the primary sensory-motor areas (motor resistance), dorsolateral prefrontal cortex (cognitive control of motor behavior), and the dorsal anterior cingulate cortex/dorsomedial prefrontal cortex and anterior insula (anxiety and emotional regulation).
Asunto(s)
Ansiedad/fisiopatología , Inestabilidad de la Articulación/fisiopatología , Imagen por Resonancia Magnética/métodos , Red Nerviosa/fisiopatología , Articulación del Hombro/fisiopatología , Adulto , Ansiedad/psicología , Giro del Cíngulo/fisiopatología , Humanos , Inestabilidad de la Articulación/patología , Inestabilidad de la Articulación/psicología , Masculino , Estimulación Luminosa/métodos , Corteza Prefrontal/fisiopatología , Estudios Prospectivos , Corteza Sensoriomotora/fisiopatología , Articulación del Hombro/patología , Resultado del Tratamiento , Adulto JovenRESUMEN
In young individuals, caffeine-mediated blockade of adenosine receptors and vasoconstriction has direct repercussions on task-related activations, changes in functional connectivity, as well as global vascular effects. To date, no study has explored the effect of caffeine on brain activation patterns during highly demanding cognitive tasks in the elderly. This prospective, placebo-controlled crossover design comprises 24 healthy elderly individuals (mean age 68.8 ± 4.0 years, 17 females) performing a 2-back working memory (WM) task in functional magnetic resonance imaging (fMRI). Analyses include complimentary assessment of task-related activations (general linear model, GLM), functional connectivity (tensorial independent component analysis, TICA), and baseline perfusion (arterial spin labeling). Despite a reduction in whole-brain global perfusion (-22.7%), caffeine-enhanced task-related GLM activation in a local and distributed network is most pronounced in the bilateral striatum and to a lesser degree in the right middle and inferior frontal gyrus, bilateral insula, left superior and inferior parietal lobule as well as in the cerebellum bilaterally. TICA was significantly enhanced (+8.2%) in caffeine versus placebo in a distributed and task-relevant network including the pre-frontal cortex, the supplementary motor area, the ventral premotor cortex and the parietal cortex as well as the occipital cortex (visual stimuli) and basal ganglia. The inverse comparison of placebo versus caffeine had no significant difference. Activation strength of the task-relevant-network component correlated with response accuracy for caffeine yet not for placebo, indicating a selective cognitive effect of caffeine. The present findings suggest that acute caffeine intake enhances WM-related brain activation as well as functional connectivity of blood oxygen level-dependent fMRI in elderly individuals.
Asunto(s)
Encéfalo/efectos de los fármacos , Cafeína/farmacología , Estimulantes del Sistema Nervioso Central/farmacología , Memoria a Corto Plazo/efectos de los fármacos , Vías Nerviosas/efectos de los fármacos , Anciano , Anciano de 80 o más Años , Circulación Cerebrovascular/efectos de los fármacos , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Lineales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Análisis de Componente Principal , Desempeño Psicomotor/efectos de los fármacos , Marcadores de SpinRESUMEN
The precipitation chemistry, deposition, nutrient pools and composition of soils and soil water, as well as an estimate of historical deposition of sulphur (S) and inorganic nitrogen (N) for the period 1860-2008, were determined in primeval deciduous and coniferous forests at the sites Javornik and Pop Ivan, respectively. Measured S throughfall inputs of 10 kg ha(-1)year(-1) in 2008 were similar to those estimated for the period 1900-1950 at both sites. The highest estimated S inputs were in the 1980s. Measured bulk deposition of N in 2008 was lower at Pop Ivan (5.6 kg ha(-1)year(-1)) compared to Javornik (12 kg ha(-1)year(-1)). Significantly lower NO(3) deposition was both estimated and measured at Pop Ivan. Higher soil base cation concentrations were observed at well-buffered Javornik underlain by flysch (Ca pool of 2046 kg ha(-1) and base saturation of 29%) compared to Pop Ivan underlain by crystalline schist (Ca pool of 186 kg ha(-1) and base saturation of 6.5%). The soil pool of organic carbon (C) was higher at Pop Ivan (212 t ha(-1)) compared to Javornik (127 t ha(-1)). The C concentration was positively correlated with organic N in the soil (p<0.001) at both sites, but the mass average C/N ratio in the forest floor was lower at Javornik (22) than at Pop Ivan (26). High N leaching of 17 kg ha(-1)year(-1) at the 90 cm depth was measured in the soil water at Javornik, suggesting high mineralization and nitrification rates in old growth deciduous forests in the area. Despite relatively low Al concentrations in the soil water, a low soil water Bc/Al ratio (0.9) (Bc=Ca+Mg+K) was found in the upper mineral soil at Pop Ivan. This suggests that the spruce forest ecosystems in the area are vulnerable to anthropogenic acidification and to the adverse effects of Al on forest root systems.
Asunto(s)
Lluvia Ácida , Contaminantes Atmosféricos/análisis , Ecosistema , Contaminantes del Suelo/análisis , Árboles , Monitoreo del Ambiente , Nitratos/análisis , Eslovaquia , Suelo/análisis , Compuestos de Azufre/análisis , UcraniaRESUMEN
HSV-1 inhibits apoptosis of infected cells, presumably to ensure that the infected cell survives long enough to allow completion of viral replication. Because cytotoxic lymphocytes kill their targets via the induction of apoptosis, protection from apoptosis could constitute a mechanism of immune evasion for HSV. Several HSV genes are involved in the inhibition of apoptosis, including Us5, which encodes glycoprotein J (gJ). Viruses deleted for Us5 showed defects in inhibition of caspase activation after Fas ligation or UV irradiation. Transfected cells expressing the Us5 gene product gJ were protected from Fas- or UV-induced apoptosis, as measured by morphology, caspase activation, membrane permeability changes, or mitochondrial transmembrane potential. In contrast, caspase 3 activation in mitochondria-free cell lysates by granzyme (gr)B was inhibited equivalently by Us5 deletion and rescue viruses, suggesting that gJ is not required for HSV to inhibition this process. However, mitochondria-free lysates from transfected cells expressing Us5/gJ were protected from grB-induced caspase activation, suggesting that Us5/gJ is sufficient to inhibit this process. Transfected cells expressing Us5/gJ were also protected from death induced by incubation with purified grB and perforin. These findings suggest that HSV has a comprehensive set of immune evasion functions that antagonize both Fas ligand- and grB-mediated pathways of CTL-induced apoptosis. The understanding of HSV effects on killing by CTL effector mechanisms may shed light on the incomplete control of HSV infections by the immune system and may allow more rational approaches to the development of immune modulatory treatments for HSV infection.
Asunto(s)
Apoptosis , Inhibidores de Caspasas , Serina Endopeptidasas/farmacología , Simplexvirus/patogenicidad , Proteínas del Envoltorio Viral/farmacología , Receptor fas/fisiología , Animales , Chlorocebus aethiops , Activación Enzimática , Granzimas , Herpesvirus Humano 1/patogenicidad , Herpesvirus Humano 2/patogenicidad , Humanos , Células Jurkat , Cinética , Transfección , Células Vero , Proteínas del Envoltorio Viral/genéticaRESUMEN
The aim of this review is to analyze the perceptual aspects of endoscopic imaging systems. After discussing depth perception in natural settings, the problems of perceiving depth in 2-dimensional representations are investigated. We discuss the impact of stereoscopic video systems on the cerebral perceptual system, emphasising the fact that despite the addition of binocular disparity information, existing stereoscopic video systems are still different from normal 3-dimensional vision. Both 2-dimensional and stereoscopic video systems require a rescaling of visual information to guide motor behavior. A review of the growing number of papers comparing 2-dimensional and stereoscopic video systems shows that only about 50% of investigators found a significant benefit for stereoscopic systems. It is unlikely that image display technology for endoscopic surgery can ever progress to the stage where it is equivalent to normal vision. Within this limitation, progress will result from a multidisciplinary approach, involving technological advances in the quality of the displayed image together with psychovisuomotor and ergonomics research, which facilitates the cerebral rescaling and perception process by the endoscopic surgeon.
Asunto(s)
Percepción de Profundidad , Laparoscopía , Presentación de Datos , Ergonomía , Humanos , Laparoscopía/métodos , Conducta Espacial , Grabación en VideoRESUMEN
The transcription factor ets-2 was phosphorylated at residue threonine 72 in a colony-stimulating factor 1 (CSF-1)- and mitogen-activated protein kinase-independent manner in macrophages isolated from motheaten-viable (me-v) mice. The CSF-1 and ets-2 target genes coding for Bcl-x, urokinase plasminogen activator, and scavenger receptor were also expressed at high levels independent of CSF-1 addition to me-v cells. Akt (protein kinase B) was constitutively active in me-v macrophages, and an Akt immunoprecipitate catalyzed phosphorylation of ets-2 at threonine 72. The p54 isoform of c-jun N-terminal kinase-stress-activated kinase (JNK- SAPK) coimmunoprecipitated with Akt from me-v macrophages, and treatment of me-v cells with the specific phosphatidylinositol 3-kinase inhibitor LY294002 decreased cell survival, Akt and JNK kinase activities, ets-2 phosphorylation, and Bcl-x mRNA expression. Therefore, ets-2 is a target for phosphatidylinositol 3-kinase-Akt-JNK action, and the JNK p54 isoform is an ets-2 kinase in macrophages. Constitutive ets-2 activity may contribute to the pathology of me-v mice by increasing expression of genes like the Bcl-x gene that promote macrophage survival.
Asunto(s)
Proteínas de Unión al ADN , Macrófagos/metabolismo , Proteínas de la Membrana , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas/metabolismo , Receptores de Lipoproteína , Proteínas Represoras , Transactivadores/metabolismo , Factores de Transcripción , Animales , Apoptosis , Northern Blotting , Western Blotting , Línea Celular , Supervivencia Celular/efectos de los fármacos , Cromonas/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Citometría de Flujo , Inmunohistoquímica , Proteínas Quinasas JNK Activadas por Mitógenos , Factor Estimulante de Colonias de Macrófagos/metabolismo , Ratones , Ratones Mutantes , Proteína Quinasa 10 Activada por Mitógenos , Morfolinas/farmacología , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosforilación , Pruebas de Precipitina , Unión Proteica , Isoformas de Proteínas , Proteínas Tirosina Quinasas/metabolismo , Proteína Proto-Oncogénica c-ets-2 , Proteínas Proto-Oncogénicas c-akt , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Receptores Inmunológicos/biosíntesis , Receptores Depuradores , Receptores Depuradores de Clase B , Transducción de Señal , Treonina/metabolismo , Factores de Tiempo , Transfección , Activador de Plasminógeno de Tipo Uroquinasa/biosíntesis , Proteína bcl-XRESUMEN
Anti-CD20 antibodies may reduce or eliminate non-Hodgkin's lymphoma B cells in patients, although the mechanism of action is not clear. To explore mechanism(s), we examined the induction of signal transduction events using anti-CD20 monoclonal antibodies (mAb) in the human non-Hodgkin's lymphoma Ramos B cell line. We found that while Rituximab (a human-mouse hybrid mAb) alone induced apoptotic cell death, other murine anti-CD20 mAbs induced apoptosis of Ramos B cells only upon clustering with a secondary antibody. CD20 clustering was accompanied by activation of tyrosine protein kinase activity, PLCgamma2 phosphorylation, influx of Ca(2+), and activation of caspase 3. All signaling events, as well as the subsequent apoptosis, were blocked by PP2, a selective inhibitor of Src-family kinases. Treatment of Ramos with EGTA and BAPTA to block changes in cytoplasmic Ca(2+) likewise prevented CD20-induced apoptosis. Our findings support a model in which CD20 clustering activates members of the Src family of protein tyrosine kinases, leading to phosphorylation of PLCgamma2 and increased cytoplasmic Ca(2+). These early signal transduction events activate caspase 3 to promote apoptotic cell death of NHL B cells.
Asunto(s)
Antígenos CD20/inmunología , Apoptosis/inmunología , Caspasas/inmunología , Linfoma de Células B/inmunología , Linfoma de Células B/patología , Transducción de Señal/inmunología , Familia-src Quinasas/inmunología , Anticuerpos Monoclonales/inmunología , Calcio/inmunología , Caspasa 3 , Activación Enzimática , Humanos , Linfoma de Células B/metabolismo , Fosforilación , Células Tumorales Cultivadas , TirosinaRESUMEN
AIMS: The aim of the study was to evaluate the long-term results of allograft and prosthetic valve replacement in the treatment of infective aortic valve endocarditis with periannular abscess. METHODS: Between March 1988 and March 1996, 65 patients underwent surgery for active aortic valve endocarditis and paravalvular abscess. The indications for surgery were congestive heart failure, systemic emboli and atrioventricular block III. The pre-operative evaluation was performed with transoesophageal echocardiography. Aortic valve replacement was performed with allografts in 47 cases, with mechanical valves in 15, and bioprosthetic valves in three cases. All patients with total ventricular-aortic dehiscence and prosthetic valve endocarditis were treated with allografts. RESULTS: The 30-day mortality rate was 23.5% in the prosthetic group, when compared with 8.5% in the patients treated with allografts. The rate of recurrent valve infections during the 11-year follow-up period was 27.1% in the prosthetic group and 3.2% in the allograft group. The actuarial 11-year survival rate was 82.1% in the allograft group and 64.7% in the prosthetic group. CONCLUSION: Aortic allografts are an effective treatment for infective aortic valve endocarditis with associated periannular abscess. The operative mortality and recurrent infection rates are lower than in the prosthetic group, resulting in a significantly higher survival rate. Diagnosis and surgical management of these cases should be based on pre-operative transoesophageal echocardiography.
Asunto(s)
Absceso/cirugía , Válvula Aórtica , Endocarditis Bacteriana/cirugía , Enfermedades de las Válvulas Cardíacas/cirugía , Implantación de Prótesis de Válvulas Cardíacas/mortalidad , Absceso/complicaciones , Adolescente , Adulto , Anciano , Supervivencia sin Enfermedad , Ecocardiografía , Endocarditis Bacteriana/complicaciones , Femenino , Alemania/epidemiología , Enfermedades de las Válvulas Cardíacas/complicaciones , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Trasplante HomólogoRESUMEN
While it is well known that rats can discriminate a peripheral injection of morphine from a saline injection, to our knowledge no one has trained rats to discriminate a direct brain-site injection of morphine from saline. In the present series of studies, one group of rats was trained to discriminate morphine (0.3 microgram) from saline injected into the perifornical area of the hypothalamus (PFA), a process that took rats about 37 sessions to learn. A dose response generalization curve for PFA-injected morphine (0.01, 0.03, 0.1, and 0.17 microgram) was generated in which the two highest doses of morphine generalized to the morphine-appropriate training stimulus. Intraperitoneal (i.p.) injection of 3 mg/kg, but not 1 mg/kg morphine, resulted in morphine-appropriate responding in the PFA morphine-trained rats. A second group of rats was trained to discriminate i.p. injections of 3 mg/kg morphine from injections of saline. A dose-response generalization test for i.p.-injected morphine (0.3, 0.56, 1.0, and 1.7 mg/kg) was conducted in which the 0.17 mg/kg dose of morphine generalized to the morphine-appropriate training stimulus. Generalization tests using PFA-injected morphine doses (0.17, 0.56, 1.0, and 3.0 microgram) failed to result in morphine-appropriate responding in the i.p. morphine-trained rats. Naloxone administered into the PFA (50 microgram) or the periphery (3 mg/kg, i.p.) blocked morphine discrimination in the PFA-trained rats. However, when naloxone was injected into the PFA (50 microgram) together with i.p. morphine (3 mg/kg) in animals trained using i.p. injections, the antagonist failed to block morphine-appropriate responding. Thus, while peripheral injection of morphine generalized to the discriminative stimulus effects of morphine produced under PFA-injection training, the opposite effects were not noted.
Asunto(s)
Aprendizaje Discriminativo/efectos de los fármacos , Aprendizaje Discriminativo/fisiología , Morfina/farmacología , Analgésicos Opioides/farmacología , Animales , Relación Dosis-Respuesta a Droga , Hipotálamo/efectos de los fármacos , Hipotálamo/fisiología , Masculino , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Ratas , Ratas Sprague-DawleyRESUMEN
INTRODUCTION: Anal incontinence is eight times more frequent in females than in males because of injuries sustained at childbirth. The aim of the present study was to determine the long-term costs associated with anal incontinence related to obstetric injuries. METHODS: Sixty-three patients with anal incontinence caused by obstetric sphincter injuries answered questionnaires regarding previous treatments, symptoms, and use of protective products. Of the patients, 31 were treated surgically, 11 with biofeedback, 6 with a combination of surgery and biofeedback, and 15 conservatively. Treatments and their respective costs were obtained from patient records, patient questionnaires, billing database, and Health Care Financing Administration's 1996 inpatient database. Costs were expressed in 1996 dollars. RESULTS: The mean incontinence score changed from 26 at evaluation to 16 at follow-up (P < 0.001). The average cost per patient was $17,166. Evaluation and follow-up charges totaled $65,412, and physiologic assessment accounted for 64 percent of these costs. Treatment charges totaled $559,341, and physician charges accounted for 18 percent of these charges. CONCLUSIONS: Fecal incontinence after childbirth results in substantial economic costs, and treatment is not always successful. New treatment modalities, such as artificial bowel sphincter or dynamic graciloplasty, should be assessed to determine their cost-effectiveness.
Asunto(s)
Canal Anal/lesiones , Costo de Enfermedad , Parto Obstétrico/efectos adversos , Incontinencia Fecal/economía , Adulto , Anciano , Canal Anal/cirugía , Biorretroalimentación Psicológica , Incontinencia Fecal/terapia , Femenino , Humanos , Estilo de Vida , Persona de Mediana Edad , Minnesota , Factores de TiempoRESUMEN
Mitral annular inflexibility due to rigid prostheses (ring or valve) has long been considered to contribute to the mechanism of dynamic left ventricular outflow tract (LVOT) obstruction after mitral repair or replacement. In clarifying the geometric relationship between LVOT orifice and mitral valve annulus (MVA) in eight normal subjects, the authors have endeavored to show how that a rigid mitral prosthesis might obstruct the LVOT based on the assumption that any rigid prosthesis necessarily follows the motion of the posterior half of the MVA (MVApost) in the course of every heart beat. During systole, the relationship between the MVApost and the approximated plane of the LVOT orifice was constant. However, with the respect to the relationship between the LVOT orifice and the approximated plane of the MVApost (PI-MVApost), the intersection between the two shifted toward the apex during systole. Assuming the prosthesis is aligned on the MVApost with the same orientation as the PI-MvApost, this shift implies a reduction in the effective size of the LVOT orifice due to the prosthesis. The calculated obstruction rate was 24.9% (0 ms), 30.9% (100 ms), 35.5% (200 ms), and 45.4% (300 ms). These results indicate the importance of maintaining the flexibility of the MVA after mitral valve surgery.
Asunto(s)
Prótesis Valvulares Cardíacas , Válvula Mitral/cirugía , Adulto , Fenómenos Biomecánicos , Prótesis Valvulares Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/métodos , Ventrículos Cardíacos/anatomía & histología , Ventrículos Cardíacos/cirugía , Humanos , Masculino , Válvula Mitral/anatomía & histología , Válvula Mitral/fisiología , Disfunción Ventricular Izquierda/etiología , Disfunción Ventricular Izquierda/prevención & control , Función VentricularRESUMEN
To evaluate the narrowing of the left ventricular outflow tract (LVOT) during systole caused by a rigid mitral prosthesis, the geometric relationship between the prosthesis (or the mitral annulus) and the left ventricular base (LVB) was studied in five patients with mechanical mitral valve prostheses and eight normal subjects. The images of the mitral valve annulus (MVA) and the LVOT orifice reconstructed in three dimensions were projected on the plane of the LV base. Calculating the areas of these projected images (i.e., those for MVA [Sm], LVOT orifice [So], the LVB [Sb; Sb = Sm + So]), the MVA-LVB ratio (Sm/Sb) was determined. In the normal subject, the MVA-LVB ratio was nearly constant during systole (59 +/- 5% at 0 msec and 62 +/- 7% at 300 msec, respectively), whereas in the patients with prostheses, the ratio increased from 61 +/- 4% (0 msec) to 69 +/- 4% (300 msec). The increase in MVA-LVB ratio reduces the proportionate share of LVOT orifice in relation to the total LVB. The ideal mitral valve prosthesis should be flexible at the annulus to attain good performance in LVB dynamics.
Asunto(s)
Prótesis Valvulares Cardíacas , Corazón/anatomía & histología , Corazón/fisiología , Válvula Mitral , Adulto , Anciano , Fenómenos Biomecánicos , Estudios de Casos y Controles , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Válvula Mitral/anatomía & histología , Válvula Mitral/fisiología , Contracción Miocárdica , Sístole , Función Ventricular IzquierdaRESUMEN
The mechanism of left ventricular outflow tract (LVOT) obstruction in the patient after mitral valve replacement or repair was examined with the aid of 2D echocardiography. For the interpretation of the spatial relationship between the aortic root and mitral annulus, however, the 2D display is sometimes inadequate since it may not simultaneously capture these structures in each center. We developed a method to clarify this relationship in 3D based on magnetic resonance images. We defined the office of the left ventricular outflow tract (LVOT orifice), consisting of, in turn, a muscular region, i.e., edge of the interventricular septum, and an annular region, i.e., the annulus of the anterior mitral leaflet. In this paper we present image data obtained from one of eight normal subjects examined and compare this with data of one of two patients who preoperatively suffered degenerative mitral regurgitation and subsequently underwent chordal-preserving mitral valve replacement, in which anterior chordae were reattached to the anterior annulus. In the normal subject, the mitral annulus exhibited a flexible change in shape during the systole, maintaining sufficient LVOT orifice size. In the patient, the prosthetic valve exhibited translational motion during systole, resulting in dynamic LVOT obstruction. This phenomenon was also observed in one other case. Furthermore, the lateral view of the LVOT orifice revealed a projection of the prosthetic valve into the LVOT, causing mechanical LVOT obstruction. The finding that translational motion of the prosthetic valve with an inflexible mitral annulus results in dynamic LVOT obstruction may support the hypothesis that annular rigidity causes dynamic LVOT obstruction after mitral valve repair with a rigid prosthetic ring.
Asunto(s)
Prótesis Valvulares Cardíacas , Imagen por Resonancia Magnética , Insuficiencia de la Válvula Mitral/cirugía , Complicaciones Posoperatorias/diagnóstico , Obstrucción del Flujo Ventricular Externo/diagnóstico , Adulto , Estudios de Casos y Controles , Ecocardiografía , Ventrículos Cardíacos/anatomía & histología , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Función Ventricular Izquierda/fisiología , Obstrucción del Flujo Ventricular Externo/etiologíaRESUMEN
An analysis of three-dimensional movement of the mitral valve annulus (MVA) may address the question of geometrical change after mitral valve repair to preserve mitral annular function. Conventionally, annular contraction has been studied for this purpose. We investigated this geometrical change occurring in the anterior half of the MVA and discuss its clinical significance. Three-dimensional images of the MVA during systole were reconstructed from magnetic resonance images of eight normal subjects. The posterior half of the MVA exhibited translational motion. We assume that this portion, exhibiting translational motion as well as contraction, purely follows the motion of the left ventricular contraction. Compensating for the discrepancy between the motion of the aortic root and that of the posterior half of the MVA, the anterior half exhibited a flexible change in shape during systole, thus maintaining a sufficient left ventricular outflow tract (LVOT). The increase in the extent of displacement of the anterior MVA from the posterior half of the MVA during systole, which was 3.6 +/- 1.0 mm (mean +/- SD), indicates the annular flexibility. The preservation of annular flexibility may prevent LVOT obstruction. Further geometrical analysis of patients after mitral repair will clarify annular function as presented in this article.