243 research outputs found
Effective treatment of a 13-year-old boy with steroid-dependent ocular myasthenia gravis using tacrolimus
Over the past several years, tacrolimus has attracted attention as a new therapeutic drug for myasthenia gravis (MG), but few reports have considered its use for MG in pediatric patients, and most of these have focused on severe systemic MG. In this case report, we used tacrolimus to successfully treat a 13-year-old boy with ocular MG who had suffered from severe steroid complications, including a failure of thrive and osteoporosis. He first showed symptoms of ocular MG at age 2 years 3 months. At age 13 years, he was receiving PSL (3.75 mg/day), but the symptoms of ocular MG recurred. We increased the dosage of oral PSL up to 30 mg/day, and three courses of mPSL pulse therapy were applied, but these therapies had only limited effect, and his symptoms worsened. Tacrolimus was started at 0.4mg/day (0.011mg/kg/day), and every two weeks the dose was gradually increased by 0.2mg/day. His symptoms of MG began to improve three weeks after the initial administration of tacrolimus. Approximately three months after the start of tacrolimus administration, PSL was discontinued. Currently, at one year and four months after the start of tacrolimus administration, while slight ptosis is observed in the evening, it does not influence his daily life, and his condition remains comparable to that when he stopped taking PSL. No adverse effects of tacrolimus have been recognized. In pediatric patients with steroid-dependent ocular MG without thymectomy, tacrolimus may be a safe and effective alternative to steroid and thymectomy
Modeling and control of a hot micro-embossing machine
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006."June 2006."Includes bibliographical references (p. 268-273).As the market for polymer micro- and nano-devices expands there is an ever-present need for a manufacturing standard to mass produce these parts. A number of techniques for fabricating these devices are soft lithography, micro-injection molding, and micro-embossing. Micro-embossing shows great promise in terms of versatility in creating various structures, but its shortcoming is a relatively long cycle time. Therefore, it is imperative to find efficient ways of heating and cooling in addition to having good control of critical processing parameters. This thesis will address the modeling and control of a hot micro-embossing system which utilizes oil as the heating and cooling medium. There were three thermal requirements addressed for the system: steady state temperatures within 1 C, fast as possible heating and cooling cycles, and being robust to various embossing and de-embossing processing temperatures. A model of the major thermal components in the system was developed and correlated well with experimental data. It was confirmed with simulation and experimentation that a lower flow rate achieved faster heating and a higher flow rate produced faster cooling. In order to address the steady state temperature requirement a variable gain PI controller was implemented.(cont.) During heating the feedback signal was the platen temperature and during cooling the feedback signal was the mixing valve fluid outlet temperature. This variable gain PI controller in combination with the variable flow rates produced steady state temperatures for both platens from 55 to 120 °C within 1 C in 138 seconds. Cooling for both platens from 120 to 55 °C was achieved in 190 seconds. This controller worked for a variety of processing temperatures. A Labview interface was developed to automate this process for temperature step changes. Polymer microfluidic channels were successfully fabricated using this hot micro-embossing system with automated thermal control in a short cycle time.by Grant T. Shoji.S.M
Experimental Simulation of High Temperature Plasma Transport Using Almost Dimensionally Similar Cold Plasmas in the Compact Helical System
In the Compact Helical System (CHS), experimental simulation of high temperature plasma transport is attempted by using cold plasma having similar dimensionless parameters such as electron-ion collision frequency normalized by bounce frequency v*ei, averaged toroidal beta value βt and the normalized gyro radius ρs*. The cold plasma is produced by 2.45 GHz electron cyclotron waves at very low toroidal field less than 0.1 T, and has v*ei ~ 0.05?1, βt < 0.02 % and ρs* ~ 0.02?0.05. The radial profiles of fluctuation amplitude have similarity to those in a high temperature plasma. In the cold plasma with low v*ei < 0.1, internal transport barrier is clearly formed in electron density and temperature profiles when the radial electric field rapidly evolves to positive value
Neuroradiological and neurofunctional examinations for the patients with 22q11.2 deletion
Since neuroradiological features of patients with 22q11.2 deletion syndrome are not well-understood, examinations using functional imaging were performed in this study.
Brain magnetic resonance imaging(MRI) and 1H-magnetic resonance spectroscopy(MRS) were performed using a clinical 3-tesla MR imager in 4 patients with 22q11.2 deletion syndrome (2 boys and 2 girls; 2~6 years.) and 20 age- and sex-matched healthy control subjects. Furthermore, interictal 123I- iomazenil (IMZ) single photon emission computed tomography(SPECT) was examined in two of the four patients.
Among 4 patients with 22q11.2 deletion syndrome, 2 patients showed polymicrogyria and 1 patient showed agyria. Those patients with brain malformations also showed abnormal brain artery and decreased accumulation of IMZ in 123I-IMZ SPECT. Although all 4 patients showed epileptic discharges in electroencephalogram(EEG), one patient with polymicrogyria had no seizure episode. Decreases in γ-aminobutyric acid(GABA) corresponding to the areas of polymicrogyria and/or epileptic discharges in EEG were shown in all patients except for the patient with agyria.
Although consistent evidence was not seen in patients with 22q11.2 deletion syndrome in this study, brain malformations and disturbances of the GABAergic nervous system would be underlying mechanisms of the neurodevelopmental abnormalities in this syndrome
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