RESUMEN
The upgrade to the National Spherical Torus eXperiment (NSTX-U) [J. Menard et al., Nucl. Fusion 52, 083015 (2012)] increases the injected neutral beam power up to 12 MW and the plasma current up to Ip = 2 MA for plasma durations up to 5 s. The graphite plasma facing components have been re-designed to handle greater heat and energy fluxes than were seen in NSTX using a castellated design. We present the experimental testing and validation of a castellated graphite target, similar to the prototype tile design, instrumented with thermocouples at various depths in the castellation. During testing, incident heat flux is provided by a programmed electron beam system and surface temperatures are measured via infrared thermography directly viewing the target surface. It was found that the thermocouple response scaled linearly with the measured surface temperature rise regardless of thermocouple depth in the castellation. A sensitivity of 14.3 °C/kJ of deposited energy was found when treating individual castellations as a semi-infinite solid.
RESUMEN
Inclusion body myositis (IBM) is an uncommon chronic inflammatory myopathy. Although the association between other myopathies and cancer has been well established, the relationship between IBM and neoplasia is not completely understood. Unlike polymyositis (PM) or dermatomyositis (DM), IBM rarely responds to immunosuppressive treatment and the response is seldom long-lasting. We describe a case of IBM associated with endometrial carcinoma that also demonstrated a unique response to steroids alone which persisted despite cancer relapse. The factors that are associated with a response of IBM to steroids are discussed. An atypical, steroid-responsive form of the disease is delineated.
Asunto(s)
Adenocarcinoma/complicaciones , Neoplasias Endometriales/complicaciones , Miositis por Cuerpos de Inclusión/complicaciones , Corticoesteroides/uso terapéutico , Creatina Quinasa/sangre , Femenino , Humanos , Persona de Mediana Edad , Miositis por Cuerpos de Inclusión/sangre , Miositis por Cuerpos de Inclusión/tratamiento farmacológicoRESUMEN
OBJECTIVE: To correct, after 28 years, the previously reported diagnosis of ophthalmoplegia in a patient with presumed childhood spinal muscular atrophy. DESIGN: Clinical follow-up, laboratory, electrophysiologic, and muscle biopsy data are provided. RESULTS: The findings of clinical follow-up examination, electrophysiologic tests, and histologic examination of muscle specimens led to a revised diagnosis of minicore myopathy. CONCLUSIONS: Spinal muscular atrophy was diagnosed in 1967, before histochemical techniques for examining muscle tissue and quantitative electromyography became widely available. Modern laboratory techniques later made the diagnosis of minicore myopathy possible. Progressive external ophthalmoplegia has been described in 24% of patients with minicore myopathy, but there have been only 7 reports of ophthalmoplegia with spinal muscular atrophy since 1954, and some of these diagnoses have been questioned.
Asunto(s)
Músculo Esquelético/ultraestructura , Atrofia Muscular Espinal/diagnóstico , Oftalmoplejía/diagnóstico , Adulto , Diagnóstico Diferencial , Humanos , Microscopía ElectrónicaRESUMEN
Morphologic alterations in biopsies of central and peripheral nervous tissue were investigated at the light-and electron-microscopic level in the first cases of lysosomal alpha-N-acetylgalactosaminidase deficiency. Widespread spheroid formation was observed in terminal and preterminal axons. Neocortical and peripheral autonomic axons contained tubulovesicular and lamelliform membranous arrays, prominent acicular clefts, and electron-dense axoplasmic matrix, the typical ultrastructural abnormalities corresponding to axonal spheroids in many inherited and acquired axonopathies. Central and peripheral membranous distal axonal spheroids were the only neuropathologic abnormality identified; other alterations resembling those in various neuronopathic lysosomal storage diseases were not observed. The morphologic findings and the distribution of the lesion in the present disorder are remarkably similar to those reported in the inherited infantile form of neuroaxonal dystrophy with normal alpha-N-acetylgalactosaminidase activity (Seitelberger disease).
Asunto(s)
Axones/ultraestructura , Hexosaminidasas/deficiencia , Degeneración Nerviosa/fisiología , Factores de Crecimiento Nervioso/deficiencia , Neuronas/ultraestructura , Biopsia , Encéfalo/patología , Enfermedades del Sistema Nervioso Central/enzimología , Enfermedades del Sistema Nervioso Central/patología , Niño , Preescolar , Humanos , Masculino , Microscopía Electrónica , Enfermedades del Sistema Nervioso Periférico/enzimología , Enfermedades del Sistema Nervioso Periférico/patología , alfa-N-AcetilgalactosaminidasaRESUMEN
This immunohistochemical study compares the localization of the neuronal class III beta-tubulin isotype (beta III) to that of the proliferating cell nuclear antigen (PCNA)/cyclin in 46 cerebellar neuroblastic tumors (medulloblastomas). Both class III beta-tubulin (beta III) and PCNA/cyclin reactivities were present in all tumors, but the topographic distribution and cytomorphologic features of stained cells varied considerably between classic and desmoplastic medulloblastomas. Four neoplastic phenotypes, representing gradations of neuronal differentiation, were identified: [Allegranza 1991] apolar, blast-like PCNA/cyclin(+) cells devoid of beta III reactivity (Nb1); [Bravo et al. 1987] apolar, often binucleated and/or fusiform, PCNA/cyclin (+) cells with pronounced beta III staining in their protoperikarya and their growth cones (Nb2); [Burger et al. 1987] beta III-immunoreactive immature polar neurons with varying degrees of neuritic development, reading to significant neuritogenesis in the "pale islands" of desmoplastic medulloblastomas (Nb3). The majority of Nb3 phenotypes were PCNA/cyclin (-), although subpopulations of such polar tumor cells exhibiting PCNA staining were also identified; and [Burger et al. 1991] beta III-immunoreactive, PCNA/cyclin (-) mature ganglion-like cells (Nb4). A high PCNA/cyclin labeling index (> 80%) was obtained in 20 poorly differentiated classic medulloblastomas while, significant intratumoral staining heterogeneity was observed in 23 cases of desmoplastic medulloblastomas and 3 cases of "medulloblastomas with ganglion cells": A high labeling index (LI)(> 80%) in the reticulin-impregnated poorly differentiated areas of tumor contrasted with sharp decline of PCNA staining and a very low LI (< 10%) in areas of overt neoplastic neuritogenesis ("pale islands") displaying strong beta III reactivity. Neoplastic ganglion cells were beta III (+)/PCNA (-). Our findings indicate that the majority of differentiating neuronal phenotypes undergoing cytomorphological changes of neuritic development (Nb3), and all neoplastic ganglion cells (Nb4 phenotypes) are PCNA (-), in contrast to actively proliferating, poorly differentiated, tumor cells that are PCNA (+). Although PCNA staining corresponded in part, to beta III (-) blast-like elements (Nb1), a co-expressive pattern of staining for beta III and PCNA/cyclin also was observed in subpopulations of poorly differentiated tumor cells (Nb2), indicating that transformed neuroblasts are capable of expressing differentiation-associated neuronal cytoskeletal proteins while still remaining in the proliferative compartment of the cell cycle. Our observations suggest that only neuritogenesis and acquisition of ganglionic phenotype are significant maturational events in medulloblastomas (indicating entry into the quiescent phase of the cell cycle) and provide further support for the neuronal lineage and differentiation potential of these cerebellar embryonal tumors.
Asunto(s)
Biomarcadores de Tumor/análisis , Neoplasias Cerebelosas/patología , Meduloblastoma/patología , Antígeno Nuclear de Célula en Proliferación/análisis , Tubulina (Proteína)/análisis , Adolescente , Recuento de Células , División Celular/fisiología , Transformación Celular Neoplásica/patología , Neoplasias Cerebelosas/clasificación , Cerebelo/patología , Niño , Preescolar , Ciclinas/análisis , Femenino , Humanos , Técnicas para Inmunoenzimas , Lactante , Masculino , Meduloblastoma/clasificación , Neuronas/clasificación , Neuronas/patologíaRESUMEN
Myopathy may occur as a complication of human immunodeficiency virus type 1 (HIV) infection or from its treatment, zidovudine (ZDV). We reviewed our experience with HIV-infected subjects referred for neuromuscular evaluation and compared features of myopathy in ZDV-treated (+ZDV) and untreated (-ZDV) patients. Fifty patients had myopathy, 25 diagnosed by pathologic criteria and 25 by clinical and other laboratory support. Twenty patients with myopathy had weight loss sufficient for the diagnosis of HIV wasting syndrome. Thirty-one subjects were +ZDV and 19 were -ZDV. Patients in each group presented with proximal weakness, although myalgia was more common in +ZDV patients. Both groups had elevated serum CK to a similar degree (medians: +ZDV, 485; -ZDV, 471). Muscle biopsies revealed myofiber degeneration, variable inflammatory infiltrates, inclusion bodies, and mitochondrial abnormalities in both groups. We followed response to ZDV withdrawal in 15 patients. Four had increased strength, three noted less myalgia, and eight had no clinical improvement. Twelve of 13 patients improved with prednisone. Although it is difficult to distinguish the myopathies of HIV and ZDV by clinical or pathologic criteria, in the majority of our patients, myopathy is due to HIV rather than ZDV.
Asunto(s)
Complejo Relacionado con el SIDA/complicaciones , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , VIH-1 , Enfermedades Musculares/etiología , Zidovudina/efectos adversos , Complejo Relacionado con el SIDA/tratamiento farmacológico , Complejo Relacionado con el SIDA/fisiopatología , Síndrome de Inmunodeficiencia Adquirida/fisiopatología , Biopsia , Diagnóstico Diferencial , Humanos , Mitocondrias Musculares/ultraestructura , Músculos/patología , Músculos/ultraestructura , Enfermedades Musculares/inducido químicamente , Enfermedades Musculares/fisiopatología , Nervios Periféricos/patología , Nervios Periféricos/ultraestructura , Estudios Retrospectivos , Zidovudina/uso terapéuticoRESUMEN
We report a 53-year-old Jamaican man with 20 years of progressing weakness involving proximal limb muscles and neck flexors. Serum CK was 1100 IU/L. EMG demonstrated spontaneous activity, myopathic motor units, and full recruitment patterns in weak muscles. Muscle biopsy revealed marked myofiber degeneration with extensive fibrosis, suggesting a chronic myopathic process. HTLV-1 antibody was present in serum in high titers by ELISA and Western blot. Immunohistochemistry with rabbit polyclonal antisera to HTLV-1 showed rare staining myocytes. PCR demonstrated HTLV-1 DNA in frozen muscle tissue. This myopathy, associated with HTLV-1 infection, has clinical and pathological features similar to a dystrophy. We recommend serological screening for HTLV-1 in cryptogenic adult myopathies.
Asunto(s)
Infecciones por HTLV-I/complicaciones , Enfermedades Musculares/complicaciones , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Hyperinfection with Strongyloides stercoralis is rare in acquired immunodeficiency syndrome (AIDS), despite endemicity in areas where infection with human immunodeficiency virus is highly prevalent. We autopsied two patients with AIDS and disseminated Strongyloides and describe their central nervous system findings. The microscopic patterns of brain infection were dissimilar in the two patients, and reflected histology in systemic viscera. In one patient, a granulomatous response accompanied filariform larvae in all locations, including granulomatous ependymitis in brain. Additionally in the brain, larvae without tissue reaction were seen. In the second patient, the absence of tissue response to larvae was body wide, and isolated parasites were found in centrum semiovale. The occurrence of these patients in a region where Strongyloides is not endemic suggests that this infection may be more prevalent in AIDS than formerly suspected.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/patología , Encéfalo/patología , Estrongiloidiasis/patología , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/parasitología , Adulto , Animales , Encéfalo/parasitología , Humanos , Masculino , Persona de Mediana Edad , Estrongiloidiasis/complicaciones , Estrongiloidiasis/parasitologíaRESUMEN
We describe the histopathologic changes of skin, muscle, vessels, and fascia in 11 patients with eosinophilia myalgia syndrome, a newly described entity that has been linked to the ingestion of L-tryptophan. This syndrome is defined clinically by severe incapacitating myalgias and a peripheral eosinophilia. Arthralgias, edema of the extremities, morbilliform rashes, skin induration, weakness, fatigue, and respiratory weakness may be present as well. The earliest apparent histologic changes were observed at the septa between subcutaneous fat lobules and in the deep dermis or fascia. The septa and fascia were infiltrated with a sparse mixture of lymphocytes and histiocytes. In the deep fascia, in addition to inflammatory cells, there were distinctive, reactive mesenchymal cells that showed features of both histiocytes and fibrocytes. Minimal tissue eosinophilia was seen despite the extent of blood eosinophilia. Dermal thickening and homogenization of collagen bundles occurred with replacement of fat and adnexa (changes indistinguishable from scleroderma or morphea). Vessel walls in the dermis and fascia showed thickening and endothelial swelling, but no overt vasculitis was noted. Skeletal muscle biopsies showed a perimysial, epimysial, and/or fascial inflammatory infiltrate of lymphocytes and distinctive reactive mesenchymal cells with some eosinophils. Minimal myofiber atrophy, regeneration, or necrosis was seen despite the clinical history of severe myalgias in almost all patients. This syndrome should help gain insight into the mechanisms of fibrosis in environmental-induced, scleroderma-like syndromes and in idiopathic, scleroderma-like disorders as well.
Asunto(s)
Síndrome de Eosinofilia-Mialgia/patología , Eosinofilia/patología , Fascitis/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Piel/patología , Arterias Temporales/patologíaRESUMEN
Five numerical descriptors were derived from the electroencephalogram (EEG), recorded, and processed (Tracor Nomad) during emergence from isoflurane-nitrous oxide anesthesia. The five descriptors (median frequency, spectral edge frequency-90%, total power, a frequency band power ratio, and the ratio of frontal to occipital power) were compared for their ability to predict imminent arousal. Arousal was defined as spontaneous movement, coughing or eye opening. All of the descriptors except the frontal-occipital power ratio underwent significant (P less than 0.05) changes between the initial recordings made intraoperatively during surgical stimulus under anesthesia and later recordings in the 40 s preceding arousal. A post hoc analysis was performed to identify the threshold value for each parameter that best served to predict imminent arousal. For median frequency, spectral edge frequency-90%, total power, and the frequency band power ratio, thresholds that predicted imminent arousal with sensitivities of 90% and specificities of 82-90% could be identified. The data indicate that, even in the favorable circumstances of the present study (uniform anesthetic technique, post hoC identification of thresholds), none of several previously popularized EEG descriptors (median frequency, spectral edge frequency-90%, total power, a frequency band power ratio) can serve as a completely reliable sole predictor of imminent arousal. As presently derived, these EEG descriptors at best provide trend information to be used in concert with other clinical signs of depth of anesthesia.
Asunto(s)
Anestesia General , Nivel de Alerta/fisiología , Electroencefalografía/métodos , Adulto , Anciano , Ritmo alfa , Ritmo beta , Estado de Conciencia/fisiología , Ritmo Delta , Femenino , Fentanilo , Lóbulo Frontal/fisiología , Humanos , Isoflurano , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio , Morfina , Óxido Nitroso , Lóbulo Occipital/fisiología , Sensibilidad y EspecificidadRESUMEN
From the records of The Mount Sinai Hospital, seven cases which met established criteria for radiation-induced meningiomas were identified. This represents the largest series of radiogenic meningiomas documented in North America and includes both intracranial and intraspinal tumors. The records and pathological specimens were reviewed and these data analyzed with other cases retrieved from the world literature. This study reveals that radiation-induced meningiomas can be categorized into three groups based on the amount of radiation administered: 1) low dose; 2) moderate dose and miscellaneous; and 3) high dose. The overwhelming majority of cases had received low-dose irradiation (800 rad) to the scalp for tinea capitis and the second largest group resulted from high-dose irradiation for primary brain tumors (greater than 2000 rad). The unique features distinguishing radiation-induced meningiomas from other meningiomas are reviewed. Although histologically atypical tumors were common in this series, overt malignancy was not encountered. The preoperative management of these lesions should include angiography to evaluate for large-vessel occlusive vasculopathy, a known association of meningiomas induced by high-dose irradiation. Given the propensity these tumors possess for recurrence, a wide bony and dural margin is recommended at surgical resection.
Asunto(s)
Neoplasias Meníngeas/etiología , Meningioma/etiología , Neoplasias Inducidas por Radiación , Adulto , Anciano , Femenino , Humanos , Masculino , Neoplasias Meníngeas/cirugía , Meningioma/cirugía , Persona de Mediana Edad , Neoplasias Inducidas por Radiación/cirugía , Dosis de RadiaciónAsunto(s)
Infecciones por VIH/complicaciones , Enfermedades Neuromusculares/etiología , Corticoesteroides/uso terapéutico , Enfermedades Desmielinizantes/etiología , Enfermedades Desmielinizantes/terapia , Humanos , Miositis/diagnóstico , Miositis/tratamiento farmacológico , Miositis/etiología , Enfermedades Neuromusculares/terapia , Enfermedades del Sistema Nervioso Periférico/etiología , Enfermedades del Sistema Nervioso Periférico/terapia , Zidovudina/efectos adversosRESUMEN
We evaluated 5 patients with the diagnosis of HIV wasting syndrome. None had severe diarrhea or other causes for malabsorption. All had myopathy by clinical, laboratory, and muscle biopsy criteria. Withdrawal of azidothymidine in 3 patients did not lead to improvement. Corticosteroid therapy was effective in 3 patients.
Asunto(s)
Infecciones por VIH/fisiopatología , Enfermedades Musculares/tratamiento farmacológico , Síndrome de Inmunodeficiencia Adquirida/fisiopatología , Adulto , Seropositividad para VIH/fisiopatología , Humanos , Persona de Mediana Edad , Enfermedades Musculares/fisiopatología , Prednisona/administración & dosificación , Factores de Tiempo , Pérdida de Peso , Zidovudina/administración & dosificaciónAsunto(s)
Encefalopatías/genética , Hexosaminidasas/deficiencia , Acetilgalactosamina/metabolismo , Axones/patología , Encefalopatías/patología , Preescolar , Glicoconjugados/análisis , Hexosaminidasas/inmunología , Humanos , Immunoblotting , Lisosomas/enzimología , Masculino , alfa-N-AcetilgalactosaminidasaRESUMEN
Posterior tibial somatosensory evoked responses (SSERs) were recorded during administration of isoflurane and nitrous oxide. Responses arising from cortical and subcortical neural generators were examined to compare their relative resistance to anesthetic-related degradation. Recordings were performed in ten adults during anesthesia with 0.5 MAC isoflurane/60% N2O, 1.0 MAC isoflurane/60% N2O, and 1.5 MAC isoflurane/60% N2O. Thereafter, N2O was omitted and recordings were repeated during anesthesia with 1.5 and 1.0 MAC isoflurane/O2. Isoflurane resulted in a significant (P less than 0.001) dose-related decrease in the amplitude of cortical waveforms. The amplitude loss was substantial; e.g., for the first cortical waveform, amplitude decreased from 1.21 +/- 0.67 microV during 0.5 MAC isoflurane/N2O to 0.28 +/- 0.29 microV during 1.5 MAC/N2O. Elimination of N2O resulted in an increase in amplitude of approximately 100% (P less than 0.04). By contrast, the amplitude of the subcortical response as recorded in vertex to linked mastoid and vertex to upper cervical spine derivations was not significantly altered by changing concentrations of isoflurane or N2O. The results suggest that subcortical SSERs may be preferable to those of cortical origin for spinal cord monitoring in situations where isoflurane and nitrous oxide, especially in varying concentrations, are the primary anesthetic agents.
Asunto(s)
Potenciales Evocados Somatosensoriales/efectos de los fármacos , Isoflurano/farmacología , Óxido Nitroso/farmacología , Encéfalo/efectos de los fármacos , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/fisiología , Humanos , Nervio Tibial/efectos de los fármacosRESUMEN
A case of syringomyelia involving the entire spinal cord secondary to a spinal intramedullary tumour is described. Cerebrospinal fluid cytology and microscopic evaluation of gross necropsy specimens revealed a primary large cell lymphoma of the central nervous system. In addition there was massive leptomenigeal lymphomatosis involving the cortex, brainstem, and cerebellum. No solitary intracranial mass lesion was found.
Asunto(s)
Linfoma/complicaciones , Neoplasias de la Médula Espinal/complicaciones , Siringomielia/etiología , Adulto , Proteínas del Líquido Cefalorraquídeo/análisis , Femenino , Humanos , Linfoma/líquido cefalorraquídeo , Linfoma/patología , Neoplasias de la Médula Espinal/líquido cefalorraquídeo , Neoplasias de la Médula Espinal/patología , Siringomielia/líquido cefalorraquídeo , Siringomielia/patologíaRESUMEN
Cerebrospinal fluid (CSF) from patients with Alzheimer's disease (AD) and controls was analyzed by one- and two-dimensional gel electrophoresis, electron microscopy, and fluorescence microscopy with thioflavin S staining. In CSF from patients with AD, abnormal proteins were found following two-dimensional gel electrophoresis and silver staining. In CSF samples from most of the AD patients studied, a highly argentophilic material was detected upon silver staining the stacking gel of the one-dimensional gels. Electron microscopy of material eluted from the stacking gel showed fibers of approximately 7-10 nm diameter, with some twisting; properties consistent with paired helical filaments or amyloid. Furthermore, material with the characteristics of amyloid (fiber diameter ranging from 4-10 nm) was found in the CSF sediment. The CSF from AD patients had significantly elevated numbers of yellow fluorescent particles following thioflavin S staining when compared with age-matched, other neurological disease controls. We did not see an increase in autofluorescence, indicating that thioflavin S staining is specific. Our data suggest that AD CSF contains plaque amyloid and possibly proteins from neurofibrillary tangles. The thioflavin S staining method appears to have potential for development as a diagnostic tool.
Asunto(s)
Enfermedad de Alzheimer/líquido cefalorraquídeo , Proteínas del Líquido Cefalorraquídeo/análisis , Anciano , Anciano de 80 o más Años , Benzotiazoles , Electroforesis/métodos , Humanos , Microscopía Electrónica , Persona de Mediana Edad , Plata , TiazolesRESUMEN
Historically, management theorists have recommended the avoidance or suppression of conflict. Modern management theorists recognize interpersonal conflict as an inevitable byproduct of growth and change. The issue is no longer avoidance of conflict but the strategy by which conflict is resolved. Various strategies of conflict resolution and the consequences of each are discussed in this article, along with guidelines for the effective use of confrontation strategy.