Topical ascorbic acid reduces myringosclerosis in perforated tympanic membranes. A study in the rat.

Myringosclerosis, a common finding after myringotomy, has been recently associated with an increased production of oxygen free radicals. Ascorbic acid's proposed actions include collagen synthesis, antioxidation, and free radical scavenging. The effects of topical ascorbic acid on healing tympanic membranes were studied. Particular attention was given to detecting the presence of myringosclerosis. Twelve Sprague-Dawley rats were bilaterally myringotomized. Their ears were randomized into group A, which received topical ascorbic acid in Gelfoam, group B, which received topical saline solution in Gelfoam, and group C, which received no treatment. The tympanic membranes were harvested on day 13, after routine otomicroscopy. Under light microscopy, the connective tissue layer of the untouched side of the pars tensa was distinctly thicker in group A than in group B or group C. At this level, the extent of sclerotic lesions was significantly less in the ascorbic acid-treated group. It is inferred that topical ascorbic acid reduces the occurrence of myringosclerosis following tympanic membrane perforations in the rat.

Determination of rates of cerebral blood flow during the gestation period under 33 weeks colour doppler pulse study

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Acute mastoiditis in children: review of the current status.

BACKGROUND: acute mastoiditis is the most common intratemporal complication of otitis media. Its management is still a challenge due to potentially serious consequences. This study was designed to evaluate the recent experience with pediatric acute mastoiditis at our institution and to determine if the incidence of this entity is changing over time. MATERIAL AND METHODS: retrospective review of records of children with acute mastoiditis treated at the hospital of the Medical School at the University of Porto, Portugal, between July 1993 and June 1998. Criteria for the diagnosis of acute mastoiditis were postauricular swelling and erythema, protrusion of the auricle, and evidence of co-existent or recent otitis media. RESULTS: 43 patients fulfilled the entry criteria. Most were boys (69%). Ages ranged from 8 months to 14 years and 4 months; infants represented 40% of the total. Acute mastoiditis was the first recognized sign of otitis media in 48% of patients. More recent years of the study saw an increase in the number of children referred with acute mastoiditis. Upon admission, 56% were under antibiotic treatment, with an average intake of 5.8 days. All patients were hospitalized; 26 cases recovered after intravenous antibiotics plus myringotomy, and the rest required an additional surgical procedure. The most common organisms recovered from cultures were Streptococcus pneumoniae and Streptococcus pyogenes. In our series, associated complications occurred in 13.9%; facial paralysis in one, and involvement of the central nervous system in five. CONCLUSIONS: pediatric acute mastoiditis continues to be a potentially dangerous infection in the antibiotic era. The incidence of this complication may be increasing recently in the community studied. Great care is required of clinicians to reach an early diagnosis in order to promote adequate management and prevent inherently severe complications.

[The noise in neonatal intensive care units]. / Le bruit dans une unité de soins intensifs néonatals.

BACKGROUND: Noise constitutes a significant problem in Neonatal Intensive Care Units (NICU) because of its potential deleterious effects on the newborn patients and staff. The aim of this study was to evaluate the degree of noise in the NICU of Hospital S João, Oporto, in order to identify its origin and possibility of reducing it. MATERIAL AND METHODS: Measurements of noise were made for 24 hours, between 13 and 14 June 1994, in five different locations inside the NICU, using a slow time constant sonometer. RESULTS: The surrounding noise level changed between 61 and 67 dB (A), with spikes over 100 dB (A). CONCLUSIONS: Our results were similar to those previously reported in the literature. The following measures to reduce the level of noise were taken: 1) reduction of alarm sounds to minimal safe level; 2) replacement of doors; 3) instructions to visitors and staff.

Linear vection in the central visual field facilitated by kinetic depth cues.

Illusory self-motion (vection) is thought to be determined by motion in the peripheral visual field, whereas stimulation of more central retinal areas results in object-motion perception. Recent data suggest that vection can be produced by stimulation of the central visual field provided it is configured as a more distant surface. In this study vection strength (tracking speed, onset latency, and the percentage of trials where vection was experienced) and the direction of self-motion produced by displays moving in the central visual field were investigated. Apparent depth, introduced by using kinetic occlusion information, influenced vection strength. Central displays perceived to be in the background elicited stronger vection than identical displays appearing in the foreground. Further, increasing the eccentricity of these displays from the central retina diminished vection strength. If the central and peripheral displays were moved in opposite directions, vection strength was unaffected, and the direction of vection was determined by motion of the central display on almost half of the trials when the centre was far. Near centres produced fewer centre-consistent responses. A complete understanding of linear vection requires that factors such as display size, retinal locus, and apparent depth plane are considered.