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To determine the characteristics of sudden deafness associated with slow blood flow (SBF) within the vertebrobasilar arteries, we evaluated 57 patients with sudden deafness using magnetic resonance imaging (MRI). We detected SBF in 12 (21%) patients, predominantly men over 50 years of age. A second MRI performed in 5 patients 2 months after the onset of symptoms showed recovery of blood flow. All 12 patients complained of vertigo. Audiological and neurotologic tests suggested that hearing loss mainly involved the inner ear. Our findings suggest that unless central lesions are detected, headache, hypoesthesia of the external ear canal, and electronystagmographic abnormalities are signs of SBF. Because sudden deafness may recur in patients who have SBF, they should be monitored and treated to prevent recurrence.

To determine the diameters of the bony nasolacrimal canal and to evaluate how they are affected by sex and age. Methods: Standard axial sinus computed tomographic images of 314 patients were assessed retrospectively; the anteroposterior and transverse diameters, the sectional area of the bony nasolacrimal canal at the level of the infraorbital margin, and the angle between the bony canal and the nasal floor were measured. Results: The mean results were as follows: anteroposterior diameter, 5.6 mm; transverse diameter, 5.0 mm; sectional area of the bony nasolacrimal canal, 22.6 mm 2 ; and angle between the bony canal and the nasal floor, 78.3°. Females had a significantly smaller anteroposterior diameter (mean 0.6 mm) and a significantly smaller transverse diameter (mean 0.3 mm). The sectional area of the bony nasolacrimal canal was 13% smaller in fe-METHODS

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Acantholytic blisters in pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are caused by a dissociation of desmosomes mediated by autoantibodies against desmoglein (Dsg) 3 and Dsg 1, respectively. The blistering occurs at the suprabasilar level in PV and at the subcorneal level in PF, which corresponds to the distribution of target antigens in the epidermis: there is a more prominent expression of Dsg 1 in the upper layer, whereas Dsg 3 is more prominent in the lower layer. To elucidate the histogenesis of acantholysis, we studied the alterations of the desmosomal components and the expression pattern of Dsg isoforms in the lesional and perilesional epidermis of pemphigus patients. The results demonstrated an internalization of the desmosomes in the lower epidermis of PV, PF and pemphigus vegetans. A similar phenomenon was induced in monolayers of keratinocytes cultured with PV sera. However, little change was observed in E-cadherin expression until acantholysis became manifest. This internalization occurred prior to overt acantholysis, and was frequently associated with the induction of Dsg 2 expression in the basilar or lower layers of the epidermis. These findings indicate an alteration of Dsg isoform expression in subclinical pemphigus lesions, which might be related to the characteristic acantholytic patterns: the suprabasilar layer in PV and the upper epidermis in PF.

Twenty-four patients with acute low-tone sensorineural hearing loss (ALHL) were examined using electrocochleography. The negative summating potential (SP) amplitude and the summating potential/action potential (AP) ratio were significantly greater in the ALHL patients than in normals. The SP/AP ratio was smaller in the ALHL patients than in patients with known Meniere's disease and moderate hearing loss, although the SP amplitude was somewhat greater in the former. An abnormal increase in the SP amplitude following click stimuli was found in 54% of the ALHL patients, while the SP/AP ratio was increased abnormally in 63% of these patients. These findings suggest that the pathophysiology of ALHL may be similar to that for endolymphatic hydrops.

The thermal decomposition of methanol in argon behind incident and reflected shock waves is studied. The reaction was followed by ultraviolet (UV) absorption between 1900 and 2200 Å and by infrared (IR) emission of methanol at wavelengths 2.4–2.9 µm, 3.1–3.9 µm and 4.8–5.2 µm and of formed species at wavelengths 2.7 µm, 3.6 µm and 4.9 µm. The temperature and the density dependences of the decomposition rate constants were observed at temperatures from 1500 to 1900 K, at total densities from 10-5 to 2×10-4 mol/cm3 and at concentrations from 0.01% to 1.0% methanol. The experimentally-determined signals are compared with the calculated values and the density-dependent rate constants of the unimolecular reaction of methanol are obtained.

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