this fraction. The MW suggested for F8-200 by the standards used in the Sephadex G-200 column ranged from 13 to 17K. In a preliminary study performed in 6.5% SDS-PAGE with the active F2-50 of hemolymph and intestinal homogenate of the unconcentrated samples, only a 14-17K band was detected (data not shown). When 10-fold concentrated F2-50 of intestinal homogenate was analyzed for protein components in SDS-PAGE, the sample revealed the presence of 5 major proteins of apparent MW of 75, 59, 42, 23, and 16K, together with other minor components. The protein having a MW in the 16K band appeared to be present at the highest concentration (Fig. 2). The intestinal homogenate was prepared without protease inhibitors to avoid toxicity. Therefore, part of the major or minor proteins detected might represent degradation products. The relative contribution of each of these components to the process of differentiation is under study at present. As F250 contained components under 75K, a contamination of F2-50 samples with the inhibitory fraction was possible, but the lack of inhibitory action suggests either negligible contamination, or neutralization of its activity by some other component. This work was supported by funds of Secretaria de Estado de Ciencia y Tecnologia y Universidad de Buenos Aires, Argentina. A.M.K. and S.M.G.C. are members of the Research Career of the Consejo Nacional de Investigaciones Cientificas y Tecnicas from Argentina. roteins detected might represent
Twenty-three patients with bilateral recurrent laryngeal nerve paralysis treated at our clinic over the past 15 years were studied. The vocal cord was fixed in a paramedian position in twelve patients, in a median position in ten patients and in our intermediate position in one patient. No surgical treatment was performed in ten patients, while thirteen patients were surgically treated. Surgical procedures were undertaken as follows: tracheotomy in three patients, endoscopic lateralization of the vocal cord by Kirchner's method in two patients, widening of the anterior glottis combined with Woodman's operation in one patient, arytenoidectomy in five patients, thyroplasty type I (Isshiki's method) in one patient, glottic closure in one patient and laryngectomy in one patient. From our long term observations, we think that arytenoidectomy is the simplest and most reliable method for reducing the laryngeal obstruction in bilateral recurrent nerve paralysis.
Encapsulated sensory corpuscles of the Krause type were found in the mucosa of surgically removed human vocal cords.The corpuscles were ellipsoidal structures of about 30 by 50μm and were located beneath the free edge in the mid-region along the intermembranous part. They contained a number of varicose nerve endings and lamellar cells. The lamellar cells had thin cytoplasmic lamellae which contained numerous cytoplasmic filaments and were interposed between the nerve endings. Attachment devices were frequently noted between the cytoplasmic lamellae and between the lamellae and nerve endings. Half-desmosomes were also noted along the plasma membrane of the lamellar cells. The intercellular space was filled with amorphous electron lucent material and contained a few collagen fibrils. Ladder-like filamentous structures were frequently encountered in the intercellular space.The location of the corpuscles at the free edge of the vocal cords suggests that the endings may receive the bilateral touch of the vibrating part of the cords in order to give sensory information for the control of the movement of the cords in phonation.
