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1.
Pediatrics ; 102(3): E32, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9724680

ABSTRACT

OBJECTIVE: To quantify pediatric injuries and deaths that result from toppled television sets. DESIGN: Retrospective analysis of incident files compiled by the US Consumer Product Safety Commission (CPSC) data systems and The Children's Hospital of Alabama (TCHA) inpatient medical records. SETTING: United States, January 1990-June 1997. TCHA, May 1995-October 1997. MAIN OUTCOME MEASURES: Morbidity or mortality as a result of a television set falling onto a child. RESULTS: Over the 7-year period from January 1990 to June 1997, 73 cases that involved falling television sets were reported to the CPSC, including 28 deaths. The mean age of all victims was 36 months (SD +/- 25.4 months). The mean age of those who died was 31 months (SD +/- 22 months). Females accounted for 42 incidents (58%) and 19 deaths (68%). The most common anatomic site of injury was the head, which accounted for 72% of cases investigated by CPSC personnel. Of the 14 deaths further investigated by the CPSC, head injury was responsible for 13, with a generalized crushing injury accounting for the other. Of the 45 cases in which data were available, dressers or stands were identified as the television support 76% of the time. The TCHA database yielded five additional cases, including one death, with demographics similar to the CPSC data. CONCLUSION: Serious injury and death can occur as a result of children toppling television sets from elevated locations in the home. The furniture on which a television set is situated is of fundamental importance. An estimate of overall risk to the population is impossible to determine from these data. In light of 73 reported cases with 28 deaths; however, injury prevention counseling and other strategies supporting in-home safety should include a secure and child-safe location for television sets. Attention should be paid to safer design and placement of this ubiquitous product. television, wounds and injuries, accidents, human, infants, children.


Subject(s)
Accidents, Home/statistics & numerical data , Cause of Death , Equipment Safety , Fractures, Bone/epidemiology , Television , Wounds and Injuries/epidemiology , Wounds, Nonpenetrating/epidemiology , Accidental Falls/prevention & control , Accidental Falls/statistics & numerical data , Accidents, Home/prevention & control , Age Distribution , Alabama/epidemiology , Child , Child, Preschool , Craniocerebral Trauma/epidemiology , Female , Humans , Incidence , Infant , Male , Retrospective Studies , Sex Distribution , Survival Rate , Wounds and Injuries/prevention & control
2.
Int J Pediatr Otorhinolaryngol ; 36(1): 23-30, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8803688

ABSTRACT

Computed tomography (CT) is a valuable imaging tool in the examination of neonates and infants with nasal obstruction. At present, however, it is difficult to quantitatively evaluate the nasal fossa with CT as normative data and the relative significance of individual nasal fossa dimensions have not been established. A standardized CT image was proposed, and performed on a prospective cohort of 56 infants up to 1 year of age. A parental questionnaire was used to identify infants with nasal obstruction. Normative data for four nasal fossa dimensions are presented and analyzed. The statistical validity of these dimensions in the diagnosis of nasal obstruction was examined; only the maximal posterior bony diameter showed a significant difference between normal and nasally obstructed infants (t-test, P = 0.05). Examples of CT findings in the above-mentioned cases as well as past cases of "choanal stenosis' are demonstrated.


Subject(s)
Nasal Cavity/anatomy & histology , Nasal Cavity/physiology , Nasal Obstruction/physiopathology , Humans , Infant , Infant, Newborn , Nasal Cavity/physiopathology , Nasal Obstruction/diagnosis , Tomography, X-Ray Computed
3.
Int J Pediatr Otorhinolaryngol ; 27(2): 127-36, 1993 Aug.
Article in English | MEDLINE | ID: mdl-8258480

ABSTRACT

Exposure to environmental tobacco smoke (ETS) has remained a controversial risk factor for otitis media in children. This study evaluates the association between exposure to ETS and recurrent acute otitis media (RAOM) in 85 cases and 85 age and gender matched controls under the age of 5 years. Cases and controls were obtained from outpatient otolaryngology and ophthalmology clinics, respectively, at the Children's Hospital of Eastern Ontario. Cases were defined as having four or more physician documented AOM episodes in the preceding 12 months and controls were otitis free in the prior 12 months. Exposure status was assessed via parental questionnaire. Controlling for other risk factors (via conditional logistic regression), such as daycare attendance, socioeconomic status, prematurity and family history of otitis media, a significant association between ETS and RAOM was evident (odds ratio = 2.68, 95% CI = 1.27-5.65). When categorized, a significant exposure response relationship between increasing level of exposure to ETS and increased risk of RAOM was evident. The population etiologic fraction indicated that up to 34% of RAOM cases may be accounted for by ETS exposure. We conclude that exposure to ETS is an important and modifiable risk factor for RAOM in children under the age of 5 years.


Subject(s)
Otitis Media/etiology , Tobacco Smoke Pollution/adverse effects , Acute Disease , Child, Preschool , Humans , Infant , Prospective Studies , Recurrence , Risk Factors
5.
Pediatrics ; 88(2): 215-22, 1991 Aug.
Article in English | MEDLINE | ID: mdl-1861917

ABSTRACT

Several studies have indicated that either the surgical insertion of ventilation tubes (VTs) or long-term treatment with sulfonamide-based antibacterials is effective in the management of otitis media with effusion (OME; otherwise known as serous otitis media, secretory otitis media, and glue ear) when compared with a no-treatment control or placebo. This controlled trial is the first to compare directly the effectiveness of these two treatments for long-standing OME. Outcome variables are treatment success rates, hearing thresholds, recurrent acute otitis media episodes, and side effects of medication or complications of VT placement. One hundred twenty-five children (aged 2.5 to 7 years) who met the usual indications for surgery (long-standing [greater than 3 months] OME and conductive hearing loss) were randomly assigned to "medical" treatment (sulfisoxazole 75 mg/kg per day for 6 months) or "surgical" treatment (bilateral insertion of VTs). Subjects underwent pure-tone audiometry (500, 1000, 2000, 4000 Hz) and otomicroscopic examination at 2, 4, 6, 12, and 18 months. A significantly greater proportion of medical subjects (67%) than surgical subjects (48%) were treatment failures at 6, 12, or 18 months (P = .0208). Surgical subjects had significantly better hearing at 2 and 4 months (P values less than .01) but not at 6, 12, and 18 months (P values greater than .2). A significantly greater proportion of surgical subjects (50%) experienced complications of treatment than did medical subjects (9%) (P less than .001). Thirty-three percent of candidates for VT placement did not require surgery when treated with a 6-month course of sulfisoxazole.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Middle Ear Ventilation , Otitis Media with Effusion/therapy , Sulfisoxazole/therapeutic use , Audiometry, Pure-Tone , Auditory Threshold/physiology , Child , Child, Preschool , Female , Hearing Loss, Conductive/etiology , Humans , Male , Otitis Media with Effusion/complications , Recurrence , Time Factors
6.
Acta Otolaryngol ; 111(2): 249-55, 1991.
Article in English | MEDLINE | ID: mdl-2068910

ABSTRACT

Transitory hearing impairment has been well documented in humans during basilar migraine attacks. Ischemia induced by activation of central nervous system adrenoreceptors by cAMP is one of the mechanisms that has been implicated, as well as calcium metabolism alterations. Propranolol-HCl has proven to be an effective treatment. Massive local adrenaline release is regarded as the primum movens mechanism triggering the liberation of other beta-receptor activators resulting in sterile edema and exudate. This exudate can be visualized (via ophthalmoscope) and is viewed as pathognomonic of a migraine attack. We investigated both the action of adrenaline and Propranolol-HCl on brainstem auditory potentials in 3 groups of young rats. The first group was perfused intra-arterially with adrenaline. The second group received the same treatment plus a prophylactic daily dose of Propranolol-HCl. The third group served as the control and received Propranolol-HCl, but was perfused with a Ringer solution. Alterations in blood flow and hearing sensitivity (BERA) following perfusion occurred in the first group only. Propranolol seems to exhibit a protective action during experimental attempts to induce migraine-like attacks in rats.


Subject(s)
Hearing Disorders/prevention & control , Migraine Disorders/complications , Propranolol/therapeutic use , Animals , Audiometry, Evoked Response , Auditory Threshold , Cerebrovascular Circulation/drug effects , Epinephrine/pharmacology , Evoked Potentials, Auditory, Brain Stem , Hearing Disorders/etiology , Migraine Disorders/chemically induced , Migraine Disorders/physiopathology , Propranolol/pharmacology , Rats , Rats, Inbred Strains
7.
Ann Otolaryngol Chir Cervicofac ; 107(4): 259-64, 1990.
Article in French | MEDLINE | ID: mdl-2221716

ABSTRACT

Acute laryngo-tracheitis in infants represents a common cause of respiratory distress with stridor accompanied with hospital admission. The prognosis is usually favorable in light of the available medical and environmental management. We performed a retrospective analysis of 1739 case reports from 1974 to 1989 with special attention being paid to infants admitted three times or more for recurrent acute laryngo-tracheitis. An ENT consultation was requested in 406 infants which resulted with an endoscopy being performed. Narrowing of the airway was noted in 75% of cases. Dynamics of fluids explains why a silent lesion becomes symptomatic as soon as an inflammatory process is also present. As there are pathologies which are life-threatening, we advocate routine endoscopy as a precautionary method of investigation, followed by close reassessments, in all cases of recurrent acute laryngo-tracheitis with dyspnea. Preferably, this procedure should be performed between dyspneic episodes.


Subject(s)
Laryngitis/diagnosis , Tracheitis/diagnosis , Acute Disease , Adolescent , Bronchoscopy , Child , Child, Preschool , Humans , Laryngeal Diseases/complications , Laryngitis/etiology , Laryngoscopy , Larynx/abnormalities , Prognosis , Recurrence , Retrospective Studies , Trachea/abnormalities , Tracheal Diseases/complications , Tracheitis/etiology
8.
Int J Pediatr Otorhinolaryngol ; 16(2): 141-8, 1988 Nov.
Article in English | MEDLINE | ID: mdl-3209361

ABSTRACT

Fluctuation of hearing thresholds in an already severely to profoundly deaf child constitutes a stressing condition and a therapeutic challenge. Thorough medical inquiries revealed strong histories of migraine headaches in the parents of 13 severely deaf children (mean age: 7 years) and two of them also presented symptoms of migraine. This disease is viewed as a form of a relatively benign cerebral vasospasm causing an intense transitory vasodilatation of the small vessels of the brain and a subsequent sterile inflammatory reaction. Liberation of histamine, serotonin and plasma kinins appear to interfere with the metabolism of nerve cells. All children in our study had suffered from anoxia at birth, a condition related to a depopulation of cochlear brainstem nuclei. Migraines may therefore produce obvious hearing symptoms when vasomotor disturbances occur in already damaged nervous structures. Treatment with propranolol hydrochloride (HCl), a potent beta-blocker, resulted in cessation of hearing fluctuations in all patients and in an improvement of thresholds in two of them. We presented our results, as well as preliminary studies on asphyxiated rats shortly after birth, with transitory artificially induced cerebral vasodilatation.


Subject(s)
Auditory Threshold , Deafness/physiopathology , Migraine Disorders/physiopathology , Animals , Auditory Threshold/drug effects , Child , Child, Preschool , Female , Hearing/drug effects , Hearing/physiology , Hearing Aids , Humans , Migraine Disorders/drug therapy , Propranolol/therapeutic use , Rats , Rats, Inbred Strains
9.
Acta Otolaryngol ; 103(5-6): 400-3, 1987.
Article in English | MEDLINE | ID: mdl-3618167

ABSTRACT

Life-threatening human sepsis is often treated using bolus intravenous aminoglycoside injections with transient deafness as a reported side effect. Young adult cats were given various high dosages of gentamicin in bolus injections (1 ml in 30 s). Scala vestibuli calcium and gentamicin, blood gentamicin and compound action potentials of the VIII nerve were measured shortly after the injections and 45 min later. An obvious relationship could be demonstrated between levels of gentamicin, decreased calcium content and acoustic thresholds elevation. Even after a high dose of 175 mg/kg that abolished action potentials at t = 2 min, recovery invariably occurred. It is believed that the reported transient hearing loss in humans may be partly attributable to a temporary blockage of calcium by gentamicin.


Subject(s)
Calcium/analysis , Gentamicins/pharmacology , Labyrinthine Fluids/analysis , Perilymph/analysis , Vestibulocochlear Nerve/physiology , Action Potentials/drug effects , Animals , Cats , Gentamicins/administration & dosage , Gentamicins/blood , Injections, Intravenous , Vestibulocochlear Nerve/drug effects
10.
Endocrinology ; 119(1): 375-80, 1986 Jul.
Article in English | MEDLINE | ID: mdl-2424746

ABSTRACT

Glucocorticoid hormones cause marked muscular atrophy, the mechanism of which is unknown. We employed a potent glucocorticoid antagonist, RU38486 [11 beta-(4-dimethylaminophenyl)17 beta-hydroxy-17 alpha-(prop-1-ynyl)estra-4,9-dien-3-one], to determine whether intracellular glucocorticoid receptors are involved. RU38486 was shown to be an effective blocker of glucocorticoid receptor binding in vivo and in vitro. Furthermore, this compound significantly blocked the loss of body and muscle weight caused by injection of dexamethasone. These data indicate that intracellular glucocorticoid receptors are important in the etiology of steroid myopathy. Studies with glucocorticoid antagonists may lead to the design of specific therapeutic modalities for the treatment of both endogenously and exogenously produced steroid myopathies.


Subject(s)
Dexamethasone/antagonists & inhibitors , Estrenes/pharmacology , Muscular Atrophy/chemically induced , Receptors, Glucocorticoid/drug effects , Animals , DNA/analysis , Dexamethasone/toxicity , Glucocorticoids/antagonists & inhibitors , Male , Mifepristone , Muscles/analysis , Muscular Atrophy/prevention & control , RNA/analysis , Rats , Receptors, Glucocorticoid/metabolism
11.
J Neurochem ; 46(6): 1942-6, 1986 Jun.
Article in English | MEDLINE | ID: mdl-3486254

ABSTRACT

The number of cytosolic androgen receptors in rat skeletal muscle increases following denervation and disuse. This increase was postulated to represent altered intracellular distribution and consequent diminished sensitivity of skeletal muscle to androgens. To test this hypothesis, we measured total (homogenate) androgen receptor levels after denervation. Total (homogenate) androgen receptor binding did not change in response to denervation of leg muscles from adult male rats. An increase in cytosolic receptor number with no increase in total (homogenate) receptor levels supports the hypothesis of altered intracellular distribution of androgen receptors in denervated muscle. Cytosolic androgen receptor binding in muscle from male rats increased by 40% after denervation, whereas in females the increase was 17%. These increases could not be altered by endocrine manipulations of males or females.


Subject(s)
Muscles/innervation , Neurons/physiology , Receptors, Androgen/metabolism , Animals , Cytosol/metabolism , Denervation , Estrenes/metabolism , Female , Kinetics , Male , Metribolone , Rats , Time Factors
12.
J Otolaryngol ; 14(3): 179-82, 1985 Jun.
Article in English | MEDLINE | ID: mdl-4068115

ABSTRACT

Malakoplakia of the tongue occurring in a nine year old Caucasian boy is reported. This rare chronic inflammatory disease usually occurs in the urinary tract, especially the bladder, and is uncommon in children. Presenting symptoms included a tongue mass mimicking tumor and dysphagia. Treatment consisted of biopsy and subsequent antibiotics toward suspected gram-negative organisms. The patient recovered uneventfully and has remained well.


Subject(s)
Malacoplakia/pathology , Tongue Diseases/pathology , Biopsy , Child , Humans , Malacoplakia/drug therapy , Male , Methylprednisolone/therapeutic use , Tobramycin/therapeutic use , Tongue/pathology , Tongue Diseases/drug therapy
13.
Exp Neurol ; 87(3): 544-56, 1985 Mar.
Article in English | MEDLINE | ID: mdl-3972054

ABSTRACT

A single dose (200 mg/kg body weight, i.p.) of 2,4-dichlorophenoxyacetic acid (2,4-D), commonly used as a herbicide, caused significant decreases in acetylcholinesterase (AChE) activity in diaphragm and other muscles of the rat. The 4S, 10S, and 16S forms of AChE were affected. The effect was maximal 15 to 24 h after injection. Choline acetyltransferase (CAT) activity was not affected. Neither AChE nor CAT activities changed in sciatic nerve from 2,4-D-treated animals. Spontaneous locomotor activity decreased dramatically 4 h after 2,4-D treatment. Myotonia that was present 1.5 h after 2,4-D injection became maximal at 2 to 6 h. Twenty-four hours after drug injection, when animals were recovering from myotonia, spontaneous locomotor activity was still depressed to 50% of control values. Prolonged distal motor latencies were observed 15 to 24 h after drug administration. AChE activity and spontaneous locomotor activity returned to control values at 48 h. Thus, 2,4-D causes a decrement of end-plate AChE, as well as behavioral and electrophysiologic changes. Decreased activity of AChE may be an early step in development of the myopathy that occurs after large dose 2,4-D.


Subject(s)
2,4-Dichlorophenoxyacetic Acid/pharmacology , Acetylcholinesterase/metabolism , Muscles/enzymology , Animals , Choline O-Acetyltransferase/metabolism , Dose-Response Relationship, Drug , Electric Stimulation , Electromyography , Male , Molecular Conformation , Muscles/drug effects , Neural Conduction/drug effects , Rats , Rats, Inbred F344 , Sciatic Nerve/enzymology
14.
J Neurochem ; 43(5): 1479-83, 1984 Nov.
Article in English | MEDLINE | ID: mdl-6333486

ABSTRACT

We investigated the effects of denervation and disuse on cytosolic androgen receptor binding by rat striated muscle. Denervation of the extensor digitorum longus and tibialis anterior muscles caused a 40-50% increase in cytosolic androgen receptor concentration with no change in apparent binding affinity. This effect was evident at 6 h postdenervation, maximal at 24 h, and declined to 120% of the control level 72 h after denervation. A 40% increase in cytosolic androgen receptor concentration was also noted 24 hr after denervation of the hormone-sensitive levator ani muscle. The effect of denervation on androgen receptors was not blocked by in vivo injection of cycloheximide; therefore, de novo receptor synthesis probably is not involved in the observed increase. Disuse, produced by subperineurial injection of tetrodotoxin into the tibial and common peroneal branches of the sciatic nerve, mimicked the effect of denervation on androgen receptor binding, suggesting that neuromuscular activity is important in regulation of receptor concentration. Possible mechanisms subserving this effect are discussed.


Subject(s)
Cytosol/metabolism , Muscle Denervation , Muscles/metabolism , Receptors, Androgen/metabolism , Receptors, Steroid/metabolism , Animals , Cycloheximide/pharmacology , Estrenes/metabolism , Kinetics , Male , Metribolone , Muscles/innervation , Rats , Receptors, Androgen/drug effects , Sciatic Nerve/drug effects , Sciatic Nerve/physiology , Tetrodotoxin/pharmacology
15.
Biochim Biophys Acta ; 766(3): 549-53, 1984 Sep 27.
Article in English | MEDLINE | ID: mdl-6548153

ABSTRACT

Contrary to previous reports brain mitochondria have a substantial capacity for net Ca2+ uptake (approx. 1.2 mueq. Ca2+ per mg protein) providing succinate is the oxidizable substrate. ATP stimulates calcium uptake (to 1.8 mueq. per mg protein), but is not required. The accumulation of Ca2+ with NAD-linked substrates is, however, significantly less. With 2-oxoglutarate, very limited Ca2+ uptake occurs before respiration is inhibited. At low concentrations (10 microM), Ca2+ stimulates the 2-oxoglutarate dehydrogenase activity of detergent solubilized mitochondria. Millimolar [Ca2+] is required for inhibition. Therefore, Ca2+ inhibition of 2-oxoglutarate oxidation can explain the low maximum uptake with this substrate, but probably not by directly effecting the dehydrogenase. Hence, the oxidation of 2-oxoglutarate can be either enhanced or suppressed depending upon the net Ca2+ accumulated by brain mitochondria.


Subject(s)
Brain/metabolism , Calcium/metabolism , Ketoglutaric Acids/metabolism , Mitochondria/metabolism , Retinal Pigments/radiation effects , Rhodopsin/radiation effects , Adenosine Triphosphate/pharmacology , Animals , Biological Transport, Active/drug effects , Calcium/pharmacology , Ketoglutarate Dehydrogenase Complex/antagonists & inhibitors , Ketoglutarate Dehydrogenase Complex/metabolism , Magnesium/pharmacology , Male , Oxidation-Reduction , Phosphates/pharmacology , Rats , Rats, Inbred Strains , Rhodopsin/analogs & derivatives , Serum Albumin, Bovine/pharmacology
16.
Arch Biochem Biophys ; 229(2): 466-76, 1984 Mar.
Article in English | MEDLINE | ID: mdl-6703706

ABSTRACT

Cytosolic and nuclear forms of the glucocorticoid receptor were characterized using immunochemical techniques. Antibodies were raised in rabbits to an Mr 58,000 fragment of the transformed (DNA-binding) glucocorticoid receptor purified from rat liver cytosol by DNA-cellulose chromatography and polyacrylamide gel electrophoresis. Antibodies reacted with the transformed receptor form in a radioimmunoassay for glucocorticoid receptor. Western blot analysis of antibody reactivity revealed a single Mr 185,000 receptor form in rat liver cytosol but a smaller Mr 85,000 form in nucleosol, indicating the Mr 85,000 form is the transformed receptor. Furthermore, western blot analysis indicates that the Mr 185,000 receptor undergoes proteolysis during receptor purification and in vitro transformation processes by generating immunochemically similar proteins of smaller molecular weights. An identical Mr 185,000 glucocorticoid receptor was detected in cytosols of four rat tissues; liver, brain, adrenal medulla, and thymus. The glucocorticoid receptor was localized to the cytoplasm and nucleus of rat adrenal medulla cells by immunohistochemistry, demonstrating the existence in vivo of the transformed receptor and translocation of the receptor from cytoplasm to nucleus.


Subject(s)
Cell Nucleus/metabolism , Liver/metabolism , Receptors, Glucocorticoid/metabolism , Receptors, Steroid/metabolism , Adrenalectomy , Animals , Antigen-Antibody Complex , Cytosol/metabolism , Immune Sera , Male , Molecular Weight , Rats , Rats, Inbred Strains , Receptors, Glucocorticoid/isolation & purification , Triamcinolone Acetonide/metabolism
17.
Audiology ; 23(3): 309-20, 1984.
Article in English | MEDLINE | ID: mdl-6732634

ABSTRACT

One group of newborn rats were given 50 mg/kg gentamicin for 20 days, 8 days after birth and were housed during the treatment in a regular incubator. They were compared to a similar group housed in regular cages and to two groups of unintoxicated newborn rats, one being exposed to the incubator noise and one being unexposed. Incubator noise was found to have no influence on gentamicin ototoxicity and to induce only a temporary threshold shift.


Subject(s)
Anti-Bacterial Agents/adverse effects , Hearing Loss, Sensorineural/chemically induced , Incubators, Infant , Noise/adverse effects , Aminoglycosides/adverse effects , Animals , Animals, Newborn , Auditory Fatigue/drug effects , Auditory Threshold/drug effects , Gentamicins/adverse effects , Hair Cells, Auditory/drug effects , Organ of Corti/drug effects , Rats , Rats, Inbred Strains , Risk
18.
J Otolaryngol ; 12(3): 194-6, 1983 Jun.
Article in English | MEDLINE | ID: mdl-6876246

ABSTRACT

Brainstem response audiometry is a technique which is objective, reliable, and non-invasive. Analysis of tracings performed on 200 subjects with no detectable clinical abnormalities inexplicably revealed an 8.5% of major anomalies. In order to avoid false interpretation, it is important to remember that brainstem response audiometry should serve only as an adjunct to other clinical techniques.


Subject(s)
Audiometry, Evoked Response , Audiometry , Brain Stem/physiopathology , Hearing/physiology , Adolescent , Adult , Brain Stem/physiology , Child , Child, Preschool , Humans , Infant , Infant, Newborn , Infant, Premature , Middle Aged
19.
Arch Otorhinolaryngol ; 234(2): 181-6, 1982.
Article in English | MEDLINE | ID: mdl-7092704

ABSTRACT

Thyroid hormones are essential to the maturation of the central nervous system and sensory organs. Hypothyroidism induced various kinds of neural retardation, including hearing deficits. Despite careful attention to replacement therapy in human neonatal hypothyroidism, psychological disorders and cerebellar malfunction may occur in later life and may be related to overdoses. Brain stem response audiometry (BSRA) is used in this study as an indicator of acoustic pathway maturation in newborn rats. Normal litters are compared to tetraiodothyronine (T4)-overtreated rats from birth to day 12 of life. Onset of hearing and acoustic maturation are accelerated in treated animals as compared to controls (p less than 0.0001). Differences between groups progressively vanish after cessation of T4 administration. However, as long as 4 months later, small differences are still present, leading one to suspect a permanent change in the functioning of the acoustic pathways.


Subject(s)
Hearing/drug effects , Thyroxine/toxicity , Animals , Audiometry, Evoked Response , Auditory Perception , Ear/drug effects , Ear/growth & development , Ear, Middle/drug effects , Ear, Middle/growth & development , Hypothyroidism/drug therapy , Rats , Rats, Inbred Strains , Thyroxine/therapeutic use
20.
Laryngoscope ; 91(12): 1985-94, 1981 Dec.
Article in English | MEDLINE | ID: mdl-7321720

ABSTRACT

Pediatricians commonly consider aminoglycoside antibiotics to be less ototoxic in neonates than in adults. This concept is based on the results of pure tone audiometry performed in children treated with aminoglycosides during the neonatal period. However, conflicting results were obtained when using brain stem response audiometry (BSRA) in a group of 26 aminoglycoside treated neonates and a control group of 20 treated neonates during their stays in intensive care units (mean gestational age: 34.6 weeks). Latencies of wave V significantly differed between the two groups indicating hearing alterations in the treated group. A statistical correlation was demonstrated between initial and final values of wave V and the total doses of antibiotic administered per kilogram of body weight (p less than 0.01). Most neonates were premature with an immature hearing apparatus. To demonstrate the effect of aminoglycosides on the developing organ of Corti, neonate kittens were chosen as animal models--the onset of hearing occurs 10 days after birth. BSRA was performed every 3 days from birth for 20 days and thereafter every 6 days for the following 30 days. Five kittens treated with a low dose of gentamicin for 20 days were compared with a control group of 5 untreated kittens from the same litters and a group of 5 adult cats receiving the same antibiotic therapy. On the 50th day, all animals were sacrificed and their cochleas were prepared for electron microscopic evaluation. No ultrastructural modifications or BSRA alterations were noted in the adult group. The untreated kittens exhibited a normal pattern of BSRA maturation and their organs of Corti appeared normal. On the contrary, evidence of abnormal hearing maturation and of anatomical damage in the outer hair cells of the first coil of the cochlea was found in the treated kittens. Laboratory findings corroborate our clinical findings that aminoglycoside antibiotics are more ototoxic in neonates than in adult cats.


Subject(s)
Aminoglycosides/adverse effects , Anti-Bacterial Agents/adverse effects , Cochlea/drug effects , Hearing/drug effects , Infant, Premature , Organ of Corti/drug effects , Animals , Audiometry , Brain Stem/physiology , Cats , Cochlea/physiology , Gentamicins , Humans , Infant, Newborn , Organ of Corti/physiology
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