The use of acoustic reflectometry in the study of middle ear effusion in children suffering from acute otits media,upper respiratory tract infection and in healthy children

This report focuses on the occurrence of middle ear effusion in children with acute otitis media (n = 62), upper respiratory tract infection (n = 81) as well as in healthy control children (n = 152). Data are reported in age categories 0–4 and 5–13 years. Middle ear effusion was found in 86% of children with acute otitis media, 49% of children with upper respiratory infection and 13% of healthy children. The younger the child, the more likely the presence of middle ear effusion in all groups. Acute otitis media and upper respiratory tract infection were clinically indistinguishable in infants. Conclusion Middle ear effusion is not generally a particularly significant clinical problem in children. Received: 31 January 1996 Accepted: 12 April 1996     

Middle ear barotrauma in patients undergoing hyperbaric oxygen therapy

Hyperbaric oxygen therapy is associated with a risk of barotrauma to the middle ear. This prospective study of 82 patients undergoing long-term therapy for chronic conditions was designed to measure the incidence and severity of middle ear barotrauma. Twenty-four patients (29.3%) required the insertion of ventilation tubes for otalgia, significantly more of whom were suffering from radionecrosis of the head and neck region (P < 0.01). Thirty-two of the remaining 58 patients (55%) underwent specialist ENT assessment by otoscopy and tympanometry. Five ears (8%) showed the otoscopic changes of barotrauma (TEED grade 3 or 4), and one ear (2%) showed tympanometric evidence of a middle ear effusion (Type B tympanogram). We conclude that despite careful tuition in pressure equalisation and the appropriate use of ventilation tubes, up to 8% of ears sustain significant barotrauma. Tympanometry is unreliable in detecting these changes, otoscopy provides the most reliable screening technique.     

Expression of epidermal growth factor, epidermal growth factor receptor and transforming growth factor-alpha in the human fetal inner ear

The expression of epidermal growth factor (EGF), EGF receptor and transforming growth factor (TGF)-alpha was analyzed in the human fetal inner ear using immuno-histochemical methods. EGF receptor was observed only in 9.5-week-old fetal vestibular epithelia. In 14- and 16-week-old fetuses, EGF receptor could not be detected. TGF-alpha was observed strongly in the 9- and 11-week-old vestibular epithelia, whereas only trace amounts were detectable in the 14- and 16-week-old vestibular epithelia. These findings suggest that EGF and TGF-alpha probably have a mitogenic effect in the sensory epithelia of the fetal inner ear, especially at early stages of development.     

Effects of low-sodium,high-potassium dietary intake on cochlear lateral wall Na+,K+-ATPase

The effect of a low Na⁺, high K⁺ diet on Na⁺,K⁺-ATPase levels in cochlear lateral wall tissues was investigated in laboratory rats by using an enzyme-linked immunosorbent assay. The low Na⁺, high K⁺ diet induced high aldosterone plasma levels in the animals as well as changes in plasma cation levels. Animals that received a low Na⁺, high K⁺ diet demonstrated a statistically significant (97%) increase in Na⁺,K⁺-ATPase levels in the stria vascularis when compared to animals that received a control diet. This increase in strial Na⁺,K⁺-ATPase levels was blocked only 70% by administration of the aldosterone antagonist, spironolactone. Findings therefore indicate that strial Na⁺,K⁺-ATPase may be modulated by both aldosterone and Na⁺,K⁺ plasma levels. Na⁺,K⁺-ATPase levels in the spiral ligament were not affected by the experimental treatment. These findings suggest that spiral ligament Na⁺,K⁺-ATPase levels may be regulated by factors other than aldosterone and Na⁺,K⁺ plasma levels. This study provides further insight into the mechanisms of the beneficial effects of salt restriction and potassium loading in patients with Méniére's disease.     

Influence of static middle ear pressure on transiently evoked otoacoustic emissions and distortion products

Otoacoustic emissions (OAE) are influenced in their amplitude and frequency spectra by the middle ear. The effects of changes in the middle ear transmission mechanisms on transiently evoked OAE (TEOAE) and distortion product emissions (DPOAE) were investigated as a function of static ear canal pressure in 25 normal-hearing test persons aged 18–35 years. The ear canal pressure was varied stepwise between positive and negative values of 200 daPa. TEOAE and DPOAE amplitudes were attenuated significantly with changes of the static ear canal pressure, with greatest changes at low frequencies (< 2 kHz). The alterations of OAE amplitude were slightly dependent on the polarity of the pressure, with positive pressure producing a greater attenuation (0.6 dB). The results demonstrate that changes in middle ear impedance can cause a misinterpretation of OAE. To avoid this problem, tympanometry should always precede OAE measurements. Alternatively, both methods can be combined using one acoustic probe, so that the emissions can be evoked at the peak of middle ear compliance.     

Cardioprotective effects of nicorandil in rabbits anaesthetized with halothane: potentiation of ischaemic preconditioning via KATP channels

1. The roles of ATP-sensitive K+ channels (KATP channels) in ischaemic or pharmacological preconditioning in the rabbit heart remain unclear. Infarct limitation by ischaemic preconditioning was abolished by the KATP channel blocker glibenclamide under ketamine/xylazine anaesthesia, but not under anaesthesia induced by pentobarbital. Infarct limitation by the KATP channel opener pinacidil was detected under ketamine/xylazine anaesthesia, but not under pentobarbital anaesthesia. Thus, these effects appear to be anaesthetic dependent. 2. In the present study, we examined whether nicorandil (a KATP channel opener nitrate) exhibits cardioprotective actions under halothane anaesthesia, another commonly used volatile anaesthetic. Control animals were subjected to 40 min coronary occlusion and 120 min reperfusion. Before 40 min ischaemia, the nicorandil group received nicorandil (100 microg/kg per min, i.v., for 10 min), the 5' preconditioning (PC) group received 5 min ischaemia/20 min reperfusion, the 2.5'PC group received 2.5 min preconditioning ischaemia/20 min reperfusion, the nicorandil +2.5'PC group received both nicorandil and 2.5 min ischaemia/20 min reperfusion, the nicorandil +2.5'PC + 5-hydroxydecanoate (5HD) group received both nicorandil and 2.5 min ischaemia/20 min reperfusion in the presence of 5-hydroxydecanoate (5HD; a KATP blocker) and the 5HD group received 5 mg/kg, i.v., 5HD alone. Myocardial infarct size in control (n = 7), nicorandil (n = 5), 5'PC (n = 8), 2.5'PC (n = 5), nicorandil + 2.5'PC (n = 5), nicorandil + 2.5'PC + 5HD (n = 5) and 5HD (n = 4) groups averaged 44.4 +/- 3.6, 41.7 +/- 5.7, 17.8 +/- 3.2,* 34.1 +/- 4.8, 21.3 +/- 4.2,* 39.1 +/- 5.6 and 38.9 +/- 5.0% of the area at risk, respectively (*P <0.05 vs control). 3. Thus, nicorandil alone did not have an infarct size-limiting effect in halothane-anaesthetized rabbits. However, the results suggest that even when nicorandil alone does not demonstrate a direct cardioprotective effect, it may enhance ischaemic preconditioning via KATP channels. Key words: ATP-sensitive K+ (KATP) channel, ischaemic preconditioning, myocardial infarction, nicorandil, rabbit.     

Pelvic inflammation induced by diagnostic laparoscopy in baboons

Objective: To test the hypothesis that diagnostic laparoscopy can cause pelviperitoneal inflammation.

Design: Retrospective analysis of data collected during a prospective controlled study in baboons.

Setting: An academic research environment.

Animal(s): Samples were collected during laparoscopies in female baboons at the Institute of Primate Research, Kenya.

Intervention(s): In the first part of the study, 44 laparoscopies were performed in 16 baboons (5 with a normal pelvis, 11 with endometriosis) during the luteal phase, with a time interval of 1 month. In the second part of the study, 53 laparoscopies were performed in 15 baboons (6 with a normal pelvis, 9 with endometriosis) during the late follicular and luteal phases of one cycle, with a median time of 3–4 days between each laparoscopy.

Main Outcome Measure(s): Peritoneal fluid (PF) was measured and analyzed for white blood cell (WBC) concentrations and, in the second part of the study, for the distribution of lymphocyte subsets (CD3, CD4, CD8, and CD20) and for the presence of cytokines transforming growth factor-β1, interleukin (IL)-6, and IL-10.

Result(s): In the first part of the study, PF volumes and WBC concentrations were comparable at the baseline and follow-up laparoscopies. In the second part of the study, PF obtained at the second laparoscopy showed a 10-fold increase in volume, a 3-fold increase in WBC concentration, a 10-fold increase in IL-6 concentration, and a 2-fold increase in transforming growth factor-β1 concentration when compared with PF obtained at the first laparoscopy. The PF subset of granulocytes and CD3-positive cells was higher and the PF subset of macrophages was lower at follow-up laparoscopies than at the baseline laparoscopy.

Conclusion(s): Diagnostic laparoscopy can cause peritoneal inflammation in baboons.     

Audiological outcomes in sudden sensorineural hearing loss with presumed inner ear hemorrhage

Objective

To explore the hearing outcomes and prognostic factors in patients with sudden sensorineural hearing loss resulting from inner ear hemorrhage.

Development of vestibular ocular reflex and gross motor function in infants with common cavity deformity as a type of inner ear malformation

Background： The function of common cavity deformity demonstrated by temporal bone CT and MRI has been unknown.

Aim/Objective: To investigate the developmental changes of vestibular ocular reflex and acquisition of postural control in infants with common cavity deformity.

Material and methods: Eight infants who were congenitally deaf complicated by common cavity deformity were studied. The damped rotational chair test was carried out to evaluate vestibular ocular reflex. Acquisition of head control and independent walking in these infants was compared with that in normal infant’s milestones of gross motor development.

Results: All of the eight infants with common cavity deformity did not show per-rotatory nystagmus in the damped rotational chair test around the first year of life. However, a normal number of beats and a longer duration of per-rotatory nystagmus for their age were recorded at around three or four years of age.

Conclusions and significance: In the eight infants with common cavity deformity, vestibular ocular reflex was not present around the first year of life, but appeared after three or four years probably because of some vestibular sensory cells. Head control and independent walking were delayed but eventually acquired by the central vestibular compensation.     

Transitions in auditory rehabilitation with bone conduction implants (BCI)

Background: The bone conductive implants (BCI) are nowadays a reliable alternative for rehabilitation of specific forms of hearing loss, i.e. conductive, mixed or single sided deafness (SSD).

Aims/Objective: To analyse the various factors in play when considering an auditory rehabilitation with a bone-conductive device (BCI).

Materials and Methods: The clinical charts of subjects who underwent BCI application at the same Implanting Center from 2005 to 2018 were retrieved analysing also the reason for eventual explantation and the alternative option (transition) for hearing rehabilitation.

Results: Nine BAHA Compact, 4 BAHA Intenso, 21 BAHA Divino, 3 BAHA BP100, 4 Ponto, 2 Sophono, 5 Bonebridge, 5 BAHA5 Attract; 11 BAHA5 Connect were used in 12 unilateral COM; 16 bilateral COM; 3 unilateral cholesteatoma; 6 bilateral cholesteatoma; 2 unilateral otosclerosis; 5 bilateral otosclerosis; 9 congenital malformations; 6 major otoneurosurgical procedures; 5 sudden deafness. Explantation was necessary for five subjects.

Conclusions: Middle ear pathology and sequels from surgery represent the most common reason for BCI implantation, both in unilateral and in bilateral cases. Transition from one implantable device to another one can be predictable, mostly when explantation is necessary.

Significance: The role of BCI for rehabilitation in middle ear pathology may be extremely important.