The contribution of the supplementary motor area to explicit and implicit timing: A high-definition transcranial Random Noise Stimulation (HD-tRNS) study.

It is becoming increasingly accepted that timing tasks, and underlying temporal processes, can be partitioned on the basis of whether they require an explicit or implicit temporal judgement. Most neuroimaging studies of timing associated explicit timing tasks with activation of the supplementary motor area (SMA). However, transcranial magnetic stimulation (TMS) studies perturbing SMA functioning across explicit timing tasks have generally reported null effects, thus failing to causally link SMA to explicit timing. The present study probed the involvement of SMA in both explicit and implicit timing tasks within a single experiment and using High-Definition transcranial Random Noise Stimulation (HD-tRNS), a previously less used technique in studies of the SMA. Participants performed two tasks that comprised the same stimulus presentation but differed in the received task instructions, which might or might not require explicit temporal judgments. Results showed a significant HD-tRNS-induced shift of perceived durations (i.e., overestimation) in the explicit timing task, whereas there was no modulation of implicit timing by HD-tRNS. Overall, these results provide initial non-invasive brain stimulation evidence on the contribution of the SMA to explicit and implicit timing tasks.

Podiatric considerations of angioleiomyoma.

Angioleiomyoma is a benign soft tissue tumor that originates from the smooth muscle of blood vessels. Such lesions must be differentiated from fibroma, lipoma, ganglionic cyst, glomus tumor, neurofibroma, leiomyosarcoma, and phlebitis. These masses appear as encapsulated, glistening nodules that ordinarily respond well to surgical excision. It will be the intent of the present study to review the clinical and histological characteristics of angioleiomyomas as they may appear in podiatric practice.

Subchondral bone cysts of the phalanges.

Subchondral phalangeal bone cysts frequently are encountered when reviewing foot x-rays. Radiologically, these lesions appear as a focus of subchondral radiolucency surrounded by a rim of sclerotic bone. Radiologic and histologic examinations demonstrate that these lesions are identical to the subchondral bone cysts associated with osteoarthritis of the hip and the more recently described cysts of the hallucal sesamoids and the head of the first metatarsal.

Stabilized normal-phase high-performance liquid chromatographic analysis of aspirin and salicylic acid in solid pharmaceutical dosage forms.

A simultaneous analysis of aspirin and nonaspirin salicylates in solid pharmaceutical dosage forms is described. Two separate extraction procedures are employed, one for plain aspirin tablets and one for tablets containing aspirin plus buffers or antacids. The analyses of the extracted samples are accomplished by a stabilized normal-phase high-performance liquid chromatographic (HPLC) procedure. Prepared samples and standards are stable for up to 24 h, and the methodology is suitable for an automated HPLC system.

Simultaneous GLC analysis of aspirin and nonaspirin salicylates in pharmaceutical tablet formulations.

The analysis of aspirin and nonaspirin salicylates in buffered and plain tablet formulations employing nearly nonaqueous extraction is described. The results obtained compare favorably with those obtained from USP procedures. A simultaneous assay for aspirin and nonaspirin salicylates in buffered tablets involves the use of an acidified chromatographic siliceous earth column for the separation of the aspirin and nonaspirin salicylates from various buffers or antacids. The methods described here have definite advantages over USP XX procedures, and the buffered aspirin tablet procedures also is adaptable to aspirin formulations containing codeine, acetaminophen, propoxyphene, caffeine, and many antihistamines.

Solid-state acetylation of codeine phosphate by aspirin.

A nonsolvolytic (solid-state) acetylation of codeine phosphate in the presence of aspirin to yield acetylcodeine phosphate is reported. GLC assays for the simultaneous determination of aspirin and salicylic acid and codeine and acetylcodeine are described. The apparent heat of activation for codeine phosphate is estimated, and the possible reaction mechanisms are discussed.

Modified USP assay for simultaneous determination of aspirin and nonaspirin salicylates in aspirin and buffered aspirin tablets.

Modified USP procedures are described for the simultaneous determination of nonaspirin salicylates and aspirin in aspirin and buffered aspirin tablets. The existing USP procedures are not stability indicating for intact aspirin when significant levels of nonaspirin salicylates are present, as is often the case in short-term, high temperature stability programs. The modified procedures yeld considerably shorter analysis times and stability-indicating assays for intact aspirin without the need for sophisticated equipment other than that presently required by USP XIX.

GLC assay for fenclorac.

A rapid stability-indicating GLC method is described for the determination of fenclorac as the diethylamine salt in dosage formulations. The procedure is also applied in detecting and quantitating the weight percent of 3-chloro-4-cyclohexylphenylglycolic acid and alpha-chloro-4-cyclohexylphenylacetic acid impurities associated with the synthesis of the fenclorac drug substance. The former compound, in addition to being an impurity, is also the degradation product of fenclorac. The procedure involves preparations of the silyl derivatives, addition of an internal standard (triphenylethylene), and use of a hydrogen flame-ionization detector. The column, with a phenyl methyl silicone liquid phase and operated at about 195degrees, is well suited for the separation. The silyl derivatives were characterized by GLC-mass spectrometry.