Interpreting auditory brainstem evoked responses and distortion product otoacoustic emissions in diabetic patients with normal hearing.

OBJECTIVE: Hearing impairment is a reported late complication of diabetes mellitus (DM). Previous studies have suggested that microangiopathic complications may cause cochlear nerve function deterioration. We evaluated the auditory brainstem evoked responses (ABRs) and distortion product otoacoustic emission (DPOAE) results according to the presence of DM in subjects with normal hearing. METHODS: A cross-sectional comparative study was conducted from January 2016 to January 2018. Auditory function tests including ABR and DPOAE were performed for outpatients complaining of unilateral tinnitus. All of analyses were conducted in ears without tinnitus on contralateral side of tinnitus ears. We included subjects showing hearing thresholds within 25 dB at 0.5, 1k, 2k, and 4k on pure tone audiometry. 45 ears in patients with type 2 diabetes mellitus and 85 ears in non-diabetic patients were finally enrolled in our study. RESULTS: Diabetic subjects showed significantly more prolonged absolute peak latencies (I, III, V) and inter-peak latencies (I-V, III-V) than non-diabetic subjects. However, there was no significant difference in the inter-peak latency (I-III) between these two groups. Diabetic subjects also showed significantly lower amplitudes at f2 frequencies of 1001, 1200, 1587, 4004, 5042, and 6348 Hz than non-diabetic subjects. Additionally, the prevalence of a DPOAE response, defined as 3 dB above the noise floor, was significantly lower in diabetic subjects than that in non-diabetic subjects. CONCLUSION: Diabetic patients with normal hearing can still have abnormal ABR and DPOAE results due to diabetic neuroangiopathy. ABR and DPOAE assessments can help in detecting subclinical auditory dysfunction, which precedes the manifestation of hearing impairment in diabetic patients.

Cortical reorganization following auditory deprivation predicts cochlear implant performance in postlingually deaf adults.

Long-term hearing loss in postlingually deaf (PD) adults may lead to brain structural changes that affect the outcomes of cochlear implantation. We studied 94 PD patients who underwent cochlear implantation and 37 patients who were MRI-scanned within 2 weeks after the onset of sudden hearing loss and expected with minimal brain structural changes in relation to deafness. Compared with those with sudden hearing loss, we found lower gray matter (GM) probabilities in bilateral thalami, superior, middle, inferior temporal cortices as well as the central cortical regions corresponding to the movement and sensation of the lips, tongue, and larynx in the PD group. Among these brain areas, the GM in the middle temporal cortex showed negative correlation with disease duration, whereas the other areas displayed positive correlations. Left superior, middle temporal cortical, and bilateral thalamic GMs were the most accurate predictors of post-cochlear implantation word recognition scores (mean absolute error [MAE] = 10.1, r = .82), which was superior to clinical variables used (MAE: 12.1, p < .05). Using the combined brain morphological and clinical features, we achieved the best prediction of the outcome (MAE: 8.51, r = .90). Our findings suggest that the cross-modal plasticity allowing the superior temporal cortex and thalamus to process other modal sensory inputs reverses the initially lower volume when deafness becomes persistent. The middle temporal cortex processing higher-level language comprehension shows persistent negative correlations with disease duration, suggesting this area's association with degraded speech comprehensions due to long-term deafness. Morphological features combined with clinical variables might play a key role in predicting outcomes of cochlear implantation.

Hyperbaric oxygen (HBO) therapy as an effective approach to the treatment of patients with severe idiopathic sudden sensorineural hearing loss.

Background: The potential etiology of idiopathic sudden sensorineural hearing loss (ISSNHL) is cochlear ischemia, therefore, hyperbaric oxygen (HBO) therapy is a promising treatment, particularly in patients with severe hearing loss (≥70 dB).Aims/objectives: To evaluate the efficacy of HBO therapy.Material and methods: The medical records of patients diagnosed with ISSNHL were retrospectively reviewed (≥70 dB). Patients received HBO therapy 14 times in addition to systemic and intratympanic steroid therapy (HBO group), or systemic and intratympanic steroid therapy only (control group).Results: Data from a total of 82 patients (83 ears) were included in the analysis; 37 (38 ears) in the HBO group and 45 (45 ears) in the control group. After 2 weeks' treatment, hearing was significantly improved in the HBO group versus controls (weighted four-frequency average 28.1 ± 26.9 dB versus 14.8 ± 13.5 dB, respectively; p < .05), particularly in the low frequency groups (0.5 kHz, 1 kHz, 2 kHz; p < .05).Conclusion and significance: These data demonstrate that HBO therapy is an effective initial treatment option for patients with ISSNHL suffering from severe hearing loss.

Amplification of transcutaneous and percutaneous bone-conduction devices with a test-band in an induced model of conductive hearing loss.

OBJECTIVE: Transcutaneous devices have a disadvantage, the dampening effect by soft tissue between the bone and devices. We investigated hearing outcomes with percutaneous and transcutaneous devices using test-bands in an induced unilateral conductive hearing loss. DESIGN: Comparison of hearing outcomes of two devices in the same individuals. STUDY SAMPLE: The right ear was plugged in 30 subjects and a test-band with devices (Cochlear™ Baha® BP110 Power and Sophono® Alpha-2 MPO™) was applied on the right mastoid tip with the left ear masked. Sound-field thresholds, speech recognition thresholds (SRTs), and word recognition scores (WRSs) were compared. RESULTS: Aided thresholds of Sophono were significantly better than those of Baha at most frequencies. Sophono WRSs (86 ± 12%) at 40 dB SPL and SRTs (14 ± 5 dB HL) were significantly better than those (73 ± 24% and 23 ± 8 dB HL) of Baha. However, Sophono WRSs (98 ± 3%) at 60 dB SPL did not differ from Baha WRSs (95 ± 12%). CONCLUSION: Amplifications of the current transcutaneous device were not inferior to those of percutaneous devices with a test-band in subjects with normal bone-conduction thresholds. Since the percutaneous devices can increase the gain when fixed to the skull by eliminating the dampening effect, both devices are expected to provide sufficient hearing amplification.

Immune and anti-oxidant effects of in ovo selenium proteinate on post-hatch experimental avian necrotic enteritis.

This study was conducted to investigate the effects of in ovo administration of selenium (Se) incorporated into hydrolyzed soybean protein (B-Taxim [BT]) on protection against experimental avian necrotic enteritis (NE). Broiler eggs were injected with either 100 µl of PBS alone (BT0), or 20 or 40 µg/egg of BT in PBS (BT20, BT40) at 18 days of embryogenesis. On day 14 post-hatch, the chickens were uninfected or orally infected with 1.0 × 10(4) oocysts of Eimeria maxima (E. maxima). On day 18 post-hatch, E. maxima-infected chickens were orally infected with 1.0 × 10(9) CFU of Clostridium perfringens (C. perfringens). Compared with untreated and infected BT0 controls, BT20 and/or BT40 birds showed increased body weights, decreased fecal shedding of E. maxima oocysts, lower serum α-toxin and NetB levels, increased levels of serum antibodies against C. perfringens α-toxin and NetB toxin, decreased levels of serum malondialdehyde, reduced serum catalase and superoxide dismutase catalytic activities, and increased intestinal levels of gene transcripts encoding interleukin (IL)-1ß, IL-6, IL-8, and peroxiredoxin-6, but decreased levels of transcripts for catalase and glutathione peroxidase. Interestingly, transcript levels for inducible nitric oxide synthase and paraoxonase/arylesterase 2 were decreased in the BT20 group and increased in the BT40 group, compared with BT0 controls. These results indicate that in ovo administration of broiler chickens with a Se-containing protein hydrolysate enhanced protection against experimental NE possibly by altering the expression of proinflammatory and anti-oxidant genes and their downstream pathways.

The butanol fraction of Eclipta prostrata (Linn) increases the formation of brain acetylcholine and decreases oxidative stress in the brain and serum of cesarean-derived rats.

Eclipta prostrata has been used as a traditional medicinal plant to prevent dementia and to enhance memory in Asia. Its potential as a nootropic and as an antioxidant have been reported in mice. We hypothesized that Eclipta may affect the formation of neurotransmitters and the inhibition of oxidative stress. Charles River cesarean-derived rats (male, 180 ± 10 g) were fed experimental diets supplemented with 0 mg (control), 25 mg (E25), 50 mg (E50), or 100 mg (E100) of a freeze-dried butanol fraction of E prostrata per kilogram of diet for 6 weeks. The acetylcholine level was significantly increased by 9.6% and 12.1% in the brains of E50 and E100 groups, respectively, as compared with the control group that was fed standard diet alone. The acetylcholine esterase activity was significantly increased by 13.1% and 19.7% in the brains of E50 and E100 groups, respectively, compared with the control group. Monoamine oxidase-B activity was significantly decreased by 10.5% in the brains of the E100 group, and the superoxide radical level was significantly reduced by 9.4% in the serum of the E100 group compared with the control group. Superoxide dismutase activity was significantly increased by 9.6% and 11.6% in the serum of E50 and E100 groups, respectively, compared with the control group. These results clearly demonstrate the effects of E prostrata on the formation of acetylcholine in the brain and the inhibition of oxidative stress in the brain and serum of rats. These findings may have implications for preventing dementia and enhancing memory function in humans.

Osteoradionecrosis of the mandible: treatment outcomes and factors influencing the progress of osteoradionecrosis.

PURPOSE: The present study was undertaken to evaluate our recent experience with mandibular osteoradionecrosis (ORN) and to identify factors that contribute to its progress. PATIENTS AND METHODS: The medical records of 114 patients who had been treated for ORN during a 16-year period (1989 to 2004) were reviewed. The patients were then divided into 2 groups according to their response to conservative treatment. Group 1 consisted of patients whose ORN resolved with conservative treatment (n = 47). Group 2 consisted of patients whose ORN was unresolved with conservative treatment or who had required radical resection of the involved tissue (n = 67). The information was obtained from the medical records of the patients and analyzed. RESULTS: The patients whose ORN was associated with an early-stage tumor or preirradiation extraction had a favorable response to conservative treatment. However, those who had an advanced primary tumor, had continued smoking and drinking after radiotherapy, had received palliative radiotherapy or a radiation dose of more than 6,000 rads, and who had an orocutaneous fistula, a pathologic fracture, swelling, or trismus had a poor response to conservative treatment. In these latter cases, radical resection of the involved tissue proved useful. CONCLUSIONS: The results of the present study have indicated that several factors (ie, the stage of the primary tumor, signs of ORN) can influence the progress of ORN. Our results suggest that radical resection is a useful method for treating mandibular ORN that does not respond to conservative treatment.

Immunostimulatory effects of oriental plum (Prunus salicina Lindl.).

The fruit of the plum tree (Prunus salicina Lindl.) has been used as a traditional medicinal food in humans to enhance immunity against infectious agents and to treat cancers. However, limited information exists on the mechanisms responsible for its immune enhancing properties. In this study, the immunostimulatory effects of a methanol extract of plum fruit following methanol evaporation and dissolving in PBS were assessed by in vitro lymphocyte proliferation, tumor cell cytotoxicity, and nitric oxide (NO) production. The crude methanol extract stimulated spleen lymphocyte proliferation and NO production by cultured macrophages, and inhibited the viability of tumor cells, significantly greater than media controls. Sequential gel filtration chromatographic separation of the extract on Sephadex G-25 and Sephacryl S-200 gel filtration columns resulted in a more purified preparation that retained the ability to induce lymphoproliferation, tumor killing, and NO production. These results suggest that Prunus salicina contains immunostimulatory components that potentially may be useful in human and veterinary medicine.

In vitro treatment of chicken peripheral blood lymphocytes, macrophages, and tumor cells with extracts of Korean medicinal plants.

A variety of different medicinal plants have traditionally been used in Asian cultures as medicinal plants to enhance immunity and treat cancers. However, limited information exists on the underlying mechanisms responsible for these immune enhancing properties. The current investigation was conducted to examine the effects of methanol extracts of 3 Korean indigenous plants (dandelion root, mustard leaf, and safflower leaf) on various in vitro parameters of innate immunity (peripheral blood lymphocyte proliferation, nitric oxide production by macrophages, and free radical scavenging activity) and tumor cell growth. All plant extracts inhibited tumor cell growth and exerted antioxidant effects compared with vehicle controls. In addition, safflower leaf extract stimulated lymphocyte proliferation and mustard leaf induced nitric oxide production. These results demonstrate, for the first time, that traditional Korean medicinal plant extracts are effective in enhancing innate immunity and suppressing tumor cell growth.