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A 55-year-old man was referred by his dermatologist for a left neck mass that had been enlarging over the preceding few months. He had no history of recent trauma or [...]

A 43-year-old man presented with an 18-month history of progressive bilateral nasal obstruction, greater on the fight than on the left, and associated clear rhinorrhea and anosmia. He also reported [...]

A 15-year-old girl presented with a history of chronic nasal obstruction that had been unresponsive to nasal steroid therapy. Flexible endoscopic examination revealed that 4+ adenoid hypertrophy had obstructed the [...]

The lip is the most common site of malignancy in the oral cavity. The lower lip is involved more often than is the upper lip; perioral skin is often involved, [...]

It has been suggested that magnesium deficiency is correlated with many diseases. 31P NMR experiments were carried out in order to investigate the effects of Na+substitution on Mg2+depletion in smooth muscle under divalent cation‐free conditions. In the taenia of guinea‐pig caeci, the intracellular free Mg2+concentration ([Mg2+]i) was estimated from the chemical shifts of (1) the β‐ATP peak alone and (2) β‐ and γ‐ATP peaks. Both estimations indicated that [Mg2+]idecreased only very slowly in Mg2+‐free, Ca2+‐free solutions in which Na+was substituted with large cations such as NMDG (N‐methyl‐D‐glucamine) and choline. Furthermore, the measurements of tension development supported the suggestion of preservation of intracellular Mg2+with NMDG substitution. Substituting extracellular Na+with the small cation, Li+, also shifted the β‐ATP peak towards a lower frequency, but the frequency shift was significantly less than that seen upon Na+substitution with K+. The estimated [Mg2+]idepletion was, however, comparable with that seen after Na+substitution with K+using the titration curves of metal‐free and Mg2+‐bound ATP obtained in Li+‐based model solutions. It was concluded that Mg2+rapidly decreases only when small cations were the major electrolyte of the extracellular medium. Na+substitutions with NMDG, choline or Li+had little effect on intracellular ATP concentration after 100 min treatment.