Computed tomography of the ethmoid labyrinth and adjacent structures.

The architecture of ethmoid labyrinths as well as their relationships with adjacent structures are reviewed, giving special emphasis to the anatomic variants common in this area. The study was performed on six young normal subjects who were submitted to high resolution computed tomography. Approximately 25 axial scans, parallel to the floor of the anterior cranial fossa, were performed on each subject; four to five coronal CT scans were also added. Further data were supplemented by examinations of 62 patients affected by nonneoplastic disease of the paranasal sinuses. Microsurgery is replacing classic macrosurgery in the treatment of nonneoplastic disease of the paranasal sinuses. This new trend requires a perfect preoperative delineation of the anatomy. For this purpose, the present paper contains a list of 10 questions which can be answered exhaustively by computed tomography on the basis of the data illustrated. The answers cover most requirements of sinus microsurgery.

Motor responses of the esophagus and lower esophageal sphincter (LES) to vestibular stimulation in man.

Pressure recordings in the esophageal body, LES and stomach were performed in 10 healthy subjects before and after caloric stimulation of the labyrinth. While esophageal and stomach responses varied or were absent, all subjects showed variations at the LES level. Duration of LES relaxation was increased and both time and amplitude of LES augmentation were significantly reduced. The physiological mechanism of labyrinthine-digestive connections and the possibility of clinical applications are discussed.

Multiplanar reconstructions in the study of ethmoid anatomy.

Multiplanar and surface reconstructions are useful tools in anatomical studies. Details of ethmoid architecture which are hard to image in axial and coronal scans are well displayed by means of oblique sections. This paper addresses reformatted images of a) the nasal lateral wall; b) the middle meatus lateral wall; c) the lamina basilaris of the middle turbinate and d) the frontonasal duct.

Can deferoxamine be considered an ototoxic drug?

Some uncertainty about deferoxamine ototoxicity is to be found in the literature. Therefore, 100 patients affected by beta-thalassemia were checked audiologically. Twelve of them showed a sensorineural hearing impairment which in most cases was confined to 4 and 8 kHz. If these results are compared with a sample of "normal" population, no significant difference can be observed, therefore excluding that deferoxamine, at least at present dosages, may be considered as a certain cause of cochlear impairment.

Histochemical study of human nasopharyngeal epithelium by horseradish peroxidase conjugated lectins.

This study proposes a simple method for assessing whether non-respiratory epithelia of the nasopharynx (i.e. cuboidal, squamous) represent a modified differentiation from the normal pseudo-stratified lining, or whether they possess common characteristics suggesting they are just in a different morphological stage. Peroxidase-labelled lectins were used, since they detect sugar residues of membrane glycoconjugates which play an important role in cell differentiation. Biopsies were taken from healthy controls and from patients affected by upper airway inflammation of varying degree and duration. While pseudostratified and cuboidal epithelia possess similar histochemical characteristics, squamous epithelium has a different behaviour; in particular it is the only type to show intense reactivity to Lotus tetragonolobus lectin (LTA). This would seem to indicate that squamous epithelium is in a different state of differentiation, possibly suggesting dysplasia. Lectins may be valuable both in morphological studies and in the clinical evaluation of airway epithelia.

Volume receptors in guinea pig labyrinth: relevance with respect to ADH and Na control.

We tested the hypothesis that changes in extracellular fluid volume are reflected by pressure changes within structures of the inner ear and that through neural pathways, a control mechanism exerts an influence on antidiuretic hormone (ADH) release and Na excretion. The study was performed on 35 guinea pigs. In protocol 1, 13 animals were studied before and after decompression of the inner ear by bilateral fluid withdrawal in an experimental setting of sustained isotonic expansion that kept the osmoreceptor partially activated and the intrathoracic volume receptors suppressed. A group of six sham-operated animals served as control. In protocol 2, nine animals were studied before and after a unilateral rise in their inner ear pressure during slightly hypertonic low-rate infusions that kept the osmoreceptor and thoracic volume receptors stimulated. A group of seven sham-operated guinea pigs served as controls. Decompression of the inner ear was attended by a rise in plasma ADH from 11.9 +/- 2.4 to 29.1 +/- 6.9 pg/ml, in urine osmolality (Uosmol) from 470 +/- 48 to 712 +/- 46 mosmol/kg (P less than 0.001), and a fall in urine flow rate (V) from 184 +/- 47 to 71 +/- 11 microliters/min (P less than 0.01), whereas plasma Na (PNa) and osmolality (Posmol) did not change. During inner ear hypertension, plasma ADH fell from 25.6 +/- 3.9 to 18.4 +/- 3.1, Uosmol from 829 +/- 58 to 627 +/- 43 (P less than 0.001), and V rose from 51 +/- 11 to 130 +/- 23 (P less than 0.001), whereas glomerular filtration rate, PNa, and Posmol did not change.(ABSTRACT TRUNCATED AT 250 WORDS)