Optimal Treatment Parameters for Ultrasound-Stimulated Microbubbles in Upregulating Proliferation and Stemness of Bone Marrow Mesenchymal Stem Cells.

OBJECTIVES: Ultrasound-targeted microbubble disruption (UTMD) is a widely used technique to improve the differentiation and proliferation capacity of mesenchymal stem cells (MSCs), but the optimal therapeutic parameters for UTMD are unclear. In this study, we aimed to find the appropriate peak negative pressure (PNP), which is a key parameter for enhancing the stemness properties and proliferation of MSCs. METHODS: Experiments were performed in UTMD group, ultrasound (US) group under different PNP exposure conditions (0.5, 1.0, and 1.5 MPa), and control group. Apoptosis safety was analyzed by flow cytometry and MSC proliferation was measured at 12, 24, and 36 hours after irradiation by cell counting kit 8. The expression of the stemness genes NANOG, OCT-4, and SOX-2 were determined by enzyme-linked immunosorbent assay (ELISA) or reverse transcription polymerase chain reaction. RESULTS: The results showed that the 1.5 MPa UTMD-treated group had the highest proliferation capacity of MSCs at 24 hours. ELISA or quantitative reverse transcription polymerase chain reaction results showed that UTMD treatment of the 1.5 MPa group significantly upregulated the expression of the stemness genes NANOG, SOX-2, and OCT-4. CONCLUSIONS: In conclusion, the appropriate peak PNP value of UTMD was 1.5 MPa, and 1.5 MPa-mediated UTMD group obviously promoted MSCs proliferation and maintained stemness by upregulating the expression of stemness genes.

Clinical Study on 136 Children with Sudden Sensorineural Hearing Loss.

BACKGROUND: The prevalence of sudden sensorineural hearing loss in children (CSSNHL) is consistently increasing. However, the pathology and prognosis of CSSNHL are still poorly understood. This retrospective study evaluated clinical characteristics and possible associated factors of CSSNHL. METHODS: One hundred and thirty-six CSSNHL patients treated in Department of Otolaryngology-Head and Neck Surgery and Institute of Otolaryngology at Chinese PLA General Hospital between July 2008 and August 2015 were included in this study. These patients were analyzed for clinical characteristics, audiological characteristics, laboratory examinations, and prognostic factors. RESULTS: Among the 136 patients (151 ears), 121 patients (121 ears, 80.1%) were diagnosed with unilaterally CSSNHL, and 15 patients (30 ears, 19.9%) with bilateral CSSNHL. The complete recovery rate of CSSNHL was 9.3%, and the overall recovery rate was 37.7%. We found that initial degree of hearing loss, onset of treatment, tinnitus, the ascending type audiogram, gender, side of hearing loss, the recorded auditory brainstem response (ABR), and distortion product otoacoustic emissions (DPOAEs) had prognostic significance. Age, ear fullness, and vertigo had no significant correlation with recovery. Furthermore, the relevant blood tests showed 30.8% of the children had abnormal white blood cell (WBC) counts, 22.1% had elevated homocysteine levels, 65.8% had high alkaline phosphatase (ALP), 33.8% had high IgE antibody levels, and 86.1% had positive cytomegalovirus (CMV) IgG antibodies. CONCLUSIONS: CSSNHL commonly occurs unilaterally and results in severe hearing loss. Initial severe hearing loss and bilateral hearing loss are negative prognostic factors for hearing recovery, while positive prognostic factors include tinnitus, gender, the ascending type audiogram, early treatment, identifiable ABR waves, and DPOAEs. Age, vertigo, and ear fullness are not correlated with the recovery. Some serologic indicators, including the level of WBC, platelet, homocysteine, ALP, positive CMV IgG antibody, fibrinogen, and some immunologic indicators, are closely related to CSSNHL.

Extracranial and intracranial complications of otitis media: 22-year clinical experience and analysis.

CONCLUSION: The morbidity of the complications has had a decreased tendency in recent decades, but the category of the complications was rather diverse. There are still many serious complications that require our attention. Surgery is still the most important treatment option. OBJECTIVE: To investigate otogenic extracranial and intracranial complications in patients with acute and chronic otitis media. METHODS: A retrospective study investigated 285 patients with extracranial and intracranial complications among the 2346 inpatients with acute or chronic otitis media with or without cholesteatoma admitted to the Department of Otolaryngology, AnHui Medical University Hospital between 1987 and 2008. RESULTS: In the 285 patients with cranial complications, 253 had a single complication, 29 had two complications, and 3 had more than two complications. Intracranial complications included meningitis (16 cases), brain abscess (42 cases), sigmoid sinus involvement (29 cases), extradural abscess (8 cases), subdural abscess (1 case), and hydrocephalus (2 cases). Extracranial complications included labyrinthitis (90 cases), mastoid abscess (79 cases), facial paralysis (47 cases), Bezold abscess (5 cases), and apicitis pyramidalis (1 case). In all, 267 patients were cured or improved without recurrence. Five patients died from complications, of whom four died of cerebral hernia and one died of multiple abscesses.

[Study of sensitivity to impulse noise in guinea pig, rat and mouse].

OBJECTIVE: To study sensitivity to impulse noise in guinea pig, rat and mice. METHODS: Six groups were divided. Group I: Guinea pigs (n = 5) were exposed to 50 impulses of 160 dB SPL; Group II: Guinea pigs (n = 5) were exposed to 100 impulses of 160 dB SPL; Group III: Guinea pigs (n = 5) were exposed to 200 impulses of 160 dB SPL; Group IV: Guinea pigs (n = 6) were exposed 400 impulses of 160 dB SPL; Group V: Rats (n = 10) were exposed to 50 impulses of 160 dB SPL; Group VI: Mice (n = 10) were exposed to 50 impulses of 160 dB SPL. ABR thresholds were determined prior to, immediately, one day, one week, two weeks and four weeks after impulse noise exposure. RESULTS: The rat and mice were shown temporary threshold shift (TTS) and permanent threshold shift (PTS) after 50 times impulse noise (160), while no TTS and PTS in the guinea pigs but it was shown TTS and PTS after 400 times impulse noise (160). CONCLUSIONS: Sensitivity to impulse noise is different among guinea pig, rat and mouse. Guinea pig has less sensitivity to impulse noise while rat and mouse have higher sensitivity to impulse noise. In addition, rat has higher sensitivity to impulse noise than mouse.

Adenoviral and adeno-associated viral vector mediated gene transfer in the guinea pig cochlea.

Peripheral sensorineural hearing loss is a very common inner ear disorder affecting nearly 10% of the population. At present there is no cure for this disorder but gene therapy has been suggested as a potentially effective method for clinical treatment in the future. Thus we investigated the effectiveness of adenoviral (Ad) and adeno-associated viral (AAV) vectors to transduce the cochlea of guinea pigs. After direct injection into the basal turn of the cochlea, we found that both Ad and AAV vectors coding for the reporter genes lacZ or GFP readily transduced spiral ganglion cells. In addition, some transgene expression was detected in the stria vascularis after AAV-GFP injection. Gene expression persisted at least 8 weeks after viral vector injection. Present findings will help to develop future gene therapy protocols in the inner ear by using Ad and AAV coding for neurotrophins such as NT-3, BDNF, GDNF and VEGF.

Protection and treatment of sensorineural hearing disorders caused by exogenous factors: experimental findings and potential clinical application.

During the last decade, there have been numerous interesting findings regarding the roles of neurotrophins, nitric oxide, reactive oxygen species, glutamate receptors, and shock protein in the auditory system. These findings have provided a scientific basis for the development of techniques to protect the auditory system against trauma as well as for the treatment of peripheral hearing disorders. This review focuses on recent advances in experimental prevention and treatment of hearing impairment which are expected to be of clinical value in the near future. Viral vector and non-viral vector gene therapy and transplantation of stem cells are discussed as potential treatments of irreversible sensorineural inner ear damage.