Immunohistochemical investigation of enkephalins in the human inner ear.

Enkephalins are generally considered as neuropeptides in the central and peripheral nervous system of mammals bound to three large precursor molecules. Several animal studies demonstrated the distribution of met- and leu-enkephalin-like immunoreactivities in neurons and terminals of the lateral olivocochlear system. The immunostainings in the medial system are more controversial. No data about the presence of different enkephalin sequences in the vestibular efferent terminals are known. In the present study, the ultrastructural localization and distribution of immunoreactivities for six different antibodies against met- and leu-enkephalins in the human cochlear and vestibular periphery were investigated. A modified method of pre-embedding immunoelectronmicroscopy was applied. Met- and leu-enkephalin-like immunoreactivities were observed in the efferent terminals of the human outer and inner hair cell region. Using different met- and leu-enkephalin antibodies, the distribution of immunoreactivities remained similar. In the five human vestibular endorgans, enkephalin-like immunostaining was absent.

Immunohistochemical and morphological studies on the human fetal cochlea: a comparative view on methods.

The preservation of morphology and antigenicity can vary uncontrollably with human fetuses since these rely heavily on immediate fixation of the temporal bone following spontaneous abortion. Once good fixation is established, there is the question of the approach taken for morphologic and immunohistochemical studies. To achieve maximal preservation for the purpose of studying normal and pathologic fetal cochleae, commonly used preparation methods for analyzing the cochlea were reviewed and compared for both immunohistochemical and morphologic studies. Cochleae obtained after spontaneous abortion ranged from the 9th gestational week to birth. Four different methods were compared for morphologic study: the block surface method; a microslicing technique; paraffin; and celloidin sectioning. For immunohistochemical study, three methods were compared: pre-embedding; paraffin; and frozen sectioning. For morphologic preservation, the block surface method gave best overall results, showing good representation of the fetal cochlea for surface preparation, light, and electron microscopy. Celloidin sectioning was also found to show good light microscopic results for both the middle and inner ear. To achieve optimal results, preservation quality, fixation procedures, and antibody all contribute to the efficacy of a methods choice.

Head and neck tumors: fractionated frameless stereotactic interstitial brachytherapy-initial experience.

The authors used a frameless stereotactic navigation system, the Vogele-Bale-Hohner head holder, and a targeting device to reproducibly position brachytherapy needles for fractionated interstitial brachytherapy in 12 patients with inoperable cancers of the head and neck. In all cases, deviations of the needle relative to the planned position were within 1-15 mm depending on the location of the tumor.