Bilateral evoked otoacoustic emissions in a child with bilateral profound hearing loss

Recording of bilateral evoked otoacoustic emissions in a 3-year-old girl with bilateral profound hearing loss is presented. No component of auditory-evoked brain stem potentials was recorded. Findings on computed tomography of the inner ear were within normal limits. At retest 3 months later, these results were unchanged. Explanations for this particular condition are presented together with a review of the literature.

Hepatitis C virus (HCV)-specific in vitro antibody secretion by peripheral blood lymphocytes: correlation with progression of disease and HCV RNA in HCV antibody-positive patients

Hepatitis C virus-specific in vitro antibody production (HCV IVAP) by peripheral blood lymphocytes in 53 HCV antibody-positive patients was investigated in comparison with alanine aminotransferase (ALT) levels and HCV RNA in serum samples. All 29 HCV IVAP-positive patients were HCV RNA positive; 26 had elevated ALT levels. Among the 24 HCV IVAP-negative patients, 16 were HCV RNA negative, with 12 presenting normal ALT values. These data indicate that HCV IVAP results are highly correlated (P < 0.001) with HCV RNA results and ALT levels. Our study indicates that HCV IVAP can be used as a novel assay in the diagnosis and pathogenesis exploration of HCV infection.

Distortion-product otoacoustic emissions in neonates: normative data

Distortion-product otoacoustic emissions (DPOEs) are otoacoustic emissions evoked by two pure tones and used in order to provide a frequency specific assessment of the mechanical properties of the cochlea. This paper first reports complete input-output DPOE functions for audiometric frequencies between 867 Hertz and 8 kHz in a normal neonate population (normative data). DPOE results were analyzed as a function of evoked otoacoustic emission (EOE) properties. Neonates having normal EOEs have large DPOEs. DPOE amplitudes in neonates are larger than in adults. Neonates with atypical EOE frequency spectrum without low frequency components had normal DPOE input-output functions only for high frequencies (above 2 kHz). DPOEs could be useful, in association with EOEs, to precisely evaluate the auditory peripheral function in neonates.

Spontaneous and evoked otoacoustic emissions in preterm neonates

Spontaneous (SOEs) and evoked otoacoustic emissions (EOEs) were recorded in a group of preterm neonates (N = 134 ears) in order to study the basic properties of SOEs and EOEs as a function of gestational age. In the study, it was found that: 1. EOEs were recorded in 93% of the tested ears; 2. SOEs were recorded in 61% of the tested ears; 3. there were no statistically significant variations of EOE amplitude with gestational age; 4. EOE spectrum did not vary with age; and 5. the two main factors influencing EOE amplitude were the SOE presence and the fast Fourier transform spectrum, especially the lower limit of the spectrum. Thus, the maturation of outer hair cell properties appears to be complete at 32 weeks of gestational age. Because a number of infants at risk for hearing loss are preterm babies, screening for EOEs, an objective, rapid, and nontraumatic technique, may prove useful in evaluating peripheral auditory dysfunction in preterm neonates.

Aryepiglottic fold excision for the treatment of severe laryngomalacia

Laryngomalacia is the most common laryngeal anomaly. Clinical presentation is most often associated with stridor, which usually resolves spontaneously by the second year of life. Infrequently, laryngomalacia can be severe and cause dyspnea and feeding difficulties. These children require surgical treatment, including tracheostomy. A new procedure has been recently described for the endoscopic excision of the aryepiglottic folds. The authors report results in 39 patients who have been treated with this procedure. One failure required tracheostomy. No recurrence of dyspnea was noticed in the other children. Gastroesophageal reflux, associated with 50% of our cases, was also noted in our only failure. We advocate endoscopic treatment in children with severe laryngomalacia.

Clinical significance of otoacoustic emissions: a perspective

The aim of this paper is to review the properties of otoacoustic emissions from a clinical point of view and to discuss the perspective interest of this test. In adults, the clinical significance of evoked otoacoustic emissions seems to be limited either in endocochlear hearing losses or for detecting retrocochlear diseases. In infants, evoked otoacoustic emissions seem to be a reliable, simple, non-invasive, and precise method for estimating auditory sensitivity for midfrequencies (1-4 kHz). Then, EOEs could be considered as an interesting way for screening auditory dysfunction in infants.

Evoked otoacoustic emissions in newborn hearing screening

Evoked otoacoustic emissions (EOEs) were recorded in a group of normally hearing neonates (n = 100 ears) to study the basic properties of EOEs and the parameters influencing them. The results obtained with EOE recordings were compared with those of behavioral screening investigations. The main properties of EOEs in neonates are: 1. EOEs can be recorded in 98% of the tested ears or neonates; 2. there were no statistically significant variations in EOE detection thresholds of neonates between the ages of 1 and 4 days; 3. no statistical difference in the EOE threshold was found between males and females; 4. all EOEs exhibited a broadband spectrum with high-component frequencies; 5. EOEs demonstrating narrowband frequency peaks super-imposed on the broadband component had detection thresholds lower than EOEs without narrowband frequency peaks. EOEs can be used as a screening test. The main clinical interest of this test is to detect the presence (i.e., normal auditory peripheral function) or the absence (i.e., pathological peripheral auditory function) of EOEs in response to a 30-dBHL click stimulation. The results of this study have important applications concerning the possible clinical use of EOEs for screening peripheral auditory dysfunction in neonates.

The effects of dietary alpha-linolenic acid on the composition of nerve membranes, enzymatic activity, amplitude of electrophysiological parameters, resistance to poisons and performance of learning tasks in rats

Feeding rats diets containing oils that have a low alpha-linolenic acid [18:3(n-3)] content, such as sunflower oil, results in reduced amounts of docosahexaenoic acid [22:6(n-3)] in all brain cells and organelles compared to rats fed a diet containing soybean oil or rapeseed oil. During the period of cerebral development there is a linear relationship between the n-3 fatty acid content of the brain and that of food until alpha-linolenic acid represents approximately 200 mg/100 g food [0.4% of the total dietary energy for 18:3(n-3)]. Beyond that point brain levels reach a plateau. Similar values are also found for other organs. The level of 22:6(n-3) in membranes is little affected by the dietary quantity of linoleic acid [18:2(n-6)] if 18:3(n-3) represents approximately 0.4% of energy. In membranes from rats fed diets containing sunflower oil, Na+, K(+)-ATPase activity in nerve terminals was 60%, 5'-nucleotidase in whole brain homogenate was 80%, and 2',3'-cyclic nucleotide 3'-phosphodiesterase was 88% of that in membranes from rats fed diets containing soybean oil. A diet low in alpha-linolenic acid leads to anomalies in the electroretinogram, which partially disappear with age. It has little effect on motor activity, but it seriously affects learning tasks as measured with the shuttle box test. Rats fed a diet low in alpha-linolenic acid showed an earlier mortality in response to an intraperitoneal injection of a neurotoxin, triethyltin, than did rats fed a normal soybean oil diet.

Surgical treatment of laryngotracheal stenosis in infants and children

Laryngotracheal stenosis in children is difficult to manage, especially in cases of acquired lesions. Of 317 cases reviewed, 75 surgical cases are reported here: 28 were congenital and 47 acquired, mostly due to endotracheal intubation. A large variety of laryngotracheoplasty techniques have been used in reconstruction, depending on the age and status of the patient, the size of the laryngeal lumen, the exact site of the stenosis and any associated anomalies. The three main techniques used have been described by Evans, Cotton, and Rethi. Stenting relied on Silastic rolls, Montgomery T-tubes and Aboulker Teflon prostheses. The results in 65 patients showed a decannulation rate of 92% in cases of congenital stenosis and 80% in acquired ones. Improvements in therapy still seem necessary in order to reduce the cannulation time following treatment and the sequelae producing dysphonia.

Evidence for repair in trypan blue-treated mouse egg cylinders: an electron microscopic study

The question of whether mammalian fetuses can correct damage induced by teratogens during early stages of embryogenesis was reinvestigated. Toward this purpose female mice were injected on day 6 of gestation with the teratogenic dye trypan blue. Within 6, 24, and 48 hr of exposure to the teratogen, egg cylinders were removed, sectioned, and prepared for electron microscopic analysis. The following organelles were examined: 1) mitochondria, 2) Golgi apparatus, 3) endoplasmic reticulum, and 4) free polysomes. On the ultrastructural level, exposure to trypan blue lead within 6 hr to fragmentation of the endoplasmic reticulum and a depletion of free polysomes in the endoderm of the egg cylinders. In ectodermal cells only the distribution of polysomes was disturbed following exposure to trypan blue. Egg cylinders harvested 24 hr after injection of trypan blue had partially recovered. Their endoplasmic reticulum and polysomes appeared closer to controls. The cells of both germ layers of most egg cylinders obtained 48 hr after injection were indistinguishable from controls when viewed with the electron microscope. No consistent changes were found in mitochondria or Golgi apparatus following trypan blue treatment. It is concluded that mouse embryos appear to be able to correct damage sustained during the egg cylinder stage, and that in spite of earlier injury affecting both germ layers such egg cylinders can develop normally as revealed by microscopic examination.

DNA synthesis index: higher for human gallbladders with cholesterol gallstones than with pigment gallstones

[3H]dThd uptake by the gallbladder epithelium was estimated in 33 patients with cholesterol stones, in 13 patients with pigment stones, and in 12 gallbladders without stones. Proliferative parameters were estimated by autoradiography after in vitro incubation with [3H]-dThd. Stones were identified by quantitative infrared spectroscopy. The degree of inflammation of the gallbladder wall was estimated by a histologic scoring method. In the gallbladders containing cholesterol stones the DNA synthesis index (1.39 +/- 0.28%) was higher (P less than .01) than in the gallbladders without stones (0.19 +/- 0.04%). No significant increase in proliferative parameters was found in the gallbladders with pigment stones (0.24 +/- 0.06%). No correlation was found between total stone number, weight or volume, and the DNA synthesis index. No evidence was observed that inflammation could influence the epithelial cell proliferation. Something in the bile of patients with cholesterol stones rather than the physical presence of stones may be the cause of the variations observed.

[Duodenal obstruction by biliary calculus]

The authors report a case of cholecysto-duodenal fistula complicated by gallstone obstruction of the duodenal bulb, revealed by vomiting. Treatment included cholecystectomy, removal of the duodenal stone and suture of the duodenal fistual. The post-operative period was unevenful.