Search PubMed⌕ Search

Biomedical subjects

A Uziel

Publications and source records attributed to A Uziel.

At least 73 records · Page 4Linked to original sources
PubMed1986

[Primary cervico-facial amylosis. Apropos of a case].

Diagnosis in a case of primary localized amylosis of the sinuses and cervical nodes was from the discovery of nasal obstruction with conductive hearing loss and cervical nodes. Biopsy confirmed the presence of amyloid deposits in the maxillary sinuses mucosa and the cervical nodes. This case illustrates the value of typing of the amylosis, rectal biopsy and investigation to detect a myeloma, thus providing confirmation of a primary localized amylosis. A literature review confirmed the rarity of this localization of amyloidosis.

Adult↗
PubMed1985

Corrective effects of thyroxine on cochlear abnormalities induced by congenital hypothyroidism in the rat. I. Morphological study.

In order to study the corrective effects of thyroxine on the cochlear abnormalities induced by congenital hypothyroidism, small doses of thyroxine were injected in propylthiouracil-treated rat pups for 2 consecutive days during selected periods of development (days 3 and 4, 6 and 7, 9 and 10, 12 and 13, 18 and 19). Some animals also received thyroid replacement therapy from days 12 to 17. Corrective effects of thyroxine on cochlear structures were observed using light microscopy and transmission electron microscopy. The corrective effects not only depended on the period of administration of the hormone, but also on the structure investigated within the organ of Corti. For a given structure, a period of maximal sensitivity to thyroxine exists which corresponds to the period of development during which that structure undergoes its main morphological changes (i.e. from 6 to 13 days for the inner sulcus epithelium, the first postnatal week for the tectorial membrane, from 6 to 10 days for the pillars and the tunnel of Corti, the second and probably a part of the third postnatal week for outer hair cell synaptogenesis).

Age Factors↗
PubMed1985

Corrective effects of thyroxine on cochlear abnormalities induced by congenital hypothyroidism in the rat. II. Electrophysiological study.

In order to study the corrective effects of thyroxine (T4) on functional abnormalities induced by congenital hypothyroidism, small doses of T4 were injected to propylthiouracil-treated (PTU-treated) rat pups for 2 consecutive days on selected periods of development (days 3 and 4, 6 and 7, 9 and 10, 12 and 13, 18 and 19). Some animals also received thyroid replacement therapy from days 12 to 17. The animals were tested electrophysiologically on day 30, by recording the compound action potential and the cochlear microphonic from the round window after click and tone burst stimulation. PTU-treated animals given T4 for 2 consecutive days demonstrated both AP and CM threshold shifts. On the contrary, PTU-treated animals given T4 from days 12 to 17 demonstrated a normal CM output of the cochlea, but still showed elevated AP thresholds. These results are discussed with previous data concerning the corrective effects of T4 on cochlear structures in PTU-treated rats previously described.

Animals↗
PubMed1985

Lectins demonstrate the presence of carbohydrates in the tectorial membrane of mammalian cochlea.

Histological sections of rat and guinea pig cochleas were exposed to lectins to identify the carbohydrates present in the tectorial membranes. N-Acetylglucosamine, galactose, mannose and fucose were found to be present in both rats and guinea pigs, but N-acetylgalactosamine was not detected. In addition, two control experiments were performed. In the first, each lectin was preincubated with its specific inhibitory sugar. In the second, the unfixed tectorial membranes were exposed to lectins. Radioautographic studies confirmed the presence of glucosamine and fucose in the tectorial membrane of 1-day-old rats.

Acetylglucosamine↗
PubMed1984

Microtubules in the cochlea of the hypothyroid developing rat.

In order to study the effects of hypothyroidism on the development of microtubules in the cochlea, rat pups were rendered hypothyroid by daily administration of propylthiouracil. Microtubules were studied by immunofluorescence and electron microscopy. The absence of immunostaining of pillar cells with antimicrotubule or antitubulin antibodies was correlated with a retarded morphological development of microtubules within these same structures. The above alterations induced an abnormal development of pillar cells, non-appearance of the tunnel of Corti, and stunted epithelial growth. In contrast, a distinct immunoreaction was observed under the outer hair cells. This was attributed to abnormal persistence of afferent dendrites containing microtubules. The results suggest that, while the effect of thyroid hormone on microtubules in afferent cochlear dendrites could not be demonstrated, thyroid hormone is necessary for the normal development of microtubules in epithelial structures.

Animals↗
PubMed1984

[Congenital vascular tumor of the larynx: cellular hemangioma].

A 9 year old child was operated upon for a very vascular tumor of the right piriform sinus, signs of which had been present at birth. Histopathologic and ultrastructural examinations showed the lesion to be composed of both endothelial and pericytic elements, suggesting the diagnosis of a cellular hemangioma. This tumoral variety, particularly rare in the larynx, has been distinguished from the group of hemangiopericytomas described by Stout and Murray, not only by its usual congenital character and course but also by its specific structure.

Child↗
PubMed1983

Cochlear synaptogenesis in the hypothyroid rat.

The effects of congenital hypothyroidism on cochlear synaptogenesis were studied using transmission electron microscopy in 30 propylthiouracil-treated rat pups 1-35 days of age. No difference with controls was observed at the level of the inner hair cells which are known to mature essentially during the prenatal period. On the contrary, hypothyroidism resulted in numerous abnormalities in synaptogenesis at the level of the outer hair cells: abnormal persistence of numerous afferent dendrites and presynaptic specializations, incomplete development of efferent terminals and absence of formation of postsynaptic cisterns. It can be concluded that hypothyroidism results in severe retardation in the postnatal development of the innervation of outer hair cells.

Animals↗
PubMed1983

Maturational and degenerative processes in the organ of Corti after neonatal hypothyroidism.

In order to study the long-term effects of neonatal hypothyroidism on the organ of Corti, rats were given propylthiouracil (PTU) during the first 30 days after birth. Cochlear changes occurring after the cessation of antithyroid treatment were studied by both physiological (brainstem auditory evoked responses: BAERs, electrocochleography) and morphological techniques (transmission and scanning electron microscopy). The first appearance of BAERs was noted between days 37 and 45. Maturation of auditory potentials was achieved within 10-15 days but was incomplete since the animals definitely demonstrated elevated thresholds around 60-70 dB SPL. Morphological results indicated that some structures, like the inner sulcus epithelium, were able to restart maturational processes that had been interrupted during the period of hypothyroidism. However, these maturational changes were considerably limited and rapidLy accompanied by severe degenerative changes involving almost all cochlear structures. Degenerative changes included the deposition of an amorphous substance within the organ of Corti, severe alterations in pillar cells (absence of formation of the tunnel of Corti, distortion of microtubules), severe outer hair cell losses with abnormalities in their innervation (absence of development of efferents and loss of afferent dendrites).

Aging↗
PubMed1983

Comparative ototoxicity of four aminoglycosidic antibiotics during the critical period of cochlear development in the rat. A functional and structural study.

The comparative ototoxicity of four aminoglycosides (amikacin, dibekacin, gentamicin and tobramycin) was evaluated in the rat during the critical period of cochlear development. Newborn rats received a daily subcutaneous injection of one of the four antibiotics for 8 consecutive days, starting on day 8 after birth (amikacin: 225 mg/kg, dibekacin: 60 mg/kg, gentamicin and tobramycin: 45 mg/kg). Evaluation of ototoxicity was assessed one month after the end of the treatment using cochlear recordings (action potential and cochlear microphonic), surface preparations and scanning electron microscopy. No functional or structural evidence of ototoxicity was found in animals treated with dibekacin. Tobramycin had a weak ototoxic effect characterized by a slight increase in N1 latency and moderate damage to OHC stereocilia (fusion and formation of giant cilia). Gentamicin-treated animals demonstrated more severe evidence of ototoxicity including increased thresholds for CM, and a higher incidence of missing hair cells and damage to OHC stereocilia. The maximal cochlear damage was observed in amikacin-treated animals: both AP and CM thresholds were severely impaired, cell counts and SEM showed extensive loss of hair cells.

Action Potentials↗
PubMed1983

[Intrapetrous neurinomas of the facial nerve and its branches. Apropos of 2 cases].

The complete removal and conservation of the facial function in neurinoma of VIIth nerve in the petrous bone, are the goals of this surgery. In 2 cases, the authors emphasize the difficulty of the diagnosis and the means of making an accurate recognition of this lesion before performing a surgical approach. In the first case, neurinoma was carried by the left nervus intermedius at the level of the genu of VII with extension in the internal auditory meatus. Prior surgery had been a suboccipital craniotomy and a second operation by sus petrosal approach was necessary. In the second case, neurinoma of the right chorda tympani was removed by the retro auricular approach. In these two cases, the facial nerve had been spared.

Adult↗
PubMed1982

[Evaluation of cochlear and vestibular functions of patients treated by dibekacin in an E.N.T. unit].

Cochlear and vestibular ototoxicity of dibekacin was evaluated in 27 patients treated with aminoglycoside after surgery on head and neck cancer. The treatment was administered intramuscularly or intravenously during 13 days at the schedule of 3 mg/kg per day. Cochlear and vestibular functions were tested by audiometry and electronystagmography before the administration of the antibiotic and on the 14th, 30th day, and for certain patients on the 4th month after the start of the treatment. No cochlear ototoxicity was found after the dibekacin treatment. On the other hand, the dibekacin treatment produced minor abnormalities of ENG (irritative pattern).

Adult↗
PubMed1982

[Experimental study of the intrauterine ototoxicity of dibekacin].

Previous works have demonstrated that mammals are more susceptible to aminoside ototoxicity during the period of auditory development. In order to test the intrauterine ototoxicity of dibekacin, an experiment was designated in pregnant guinea pigs intoxicated during the last three weeks of gestation (100, 60 and 30 mg/kg for 8 days). Newborn guinea pigs were tested electrophysiologically by recording cochlear potentials from the round window in response to filtered clicks of various frequency. No fetal ototoxicity due to dibekacin could be detected in the 36 animals tested. This study indicates that dibekacin has a very low ototoxic effect, even during the period of increased sensitivity to antibiotics. Comparatively, kanamycin has a major ototoxic effect when it is administrated at the same dosage during the same period of time.

Animals↗
PubMed1982

Glomerular lesions in the branchio-oto-renal (BOR) syndrome.

Three cases: two adults and one child, with histologically confirmed branchio-oto-renal syndrome showed prominent glomerular lesions. Typically there was segmental and focal hyalinization associated with dense deposits along the basement membrane and in the mesangium. Variable deposits of immunoglobulins IgG, IgM, and IgA as well as C3 were present. The branchio-oto-renal syndrome appears to be a familial nephropathy which may lead to renal failure.

Adult↗
PubMed1981

[Electrophysiological aspects of alcoholic epilepsy (author's transl)].

Two types of neurophysiological investigations (standard EEG and polygraphic recording of sleep) were performed on a group of subjects suffering from 'alcoholic epilepsy'. Results were then compared with data from normal subjects and chronic alcoholics without epilepsy. Epileptic patterns on standard EEG are rare. They are increased by sleep. Both the alteration of basal activity in wakefulness and the organization of sleep point to a dysfunction of the CNS. The role of chronic alcoholic intoxication in epileptic seizures could be explained through the slowly decreasing biochemical cerebral action after withdrawal, rather than by a local or diffuse effect in the CNS level.

Adult↗