Age-related hearing loss accelerates the decline in fast speech comprehension and the decompensation of cortical network connections.

Patients with age-related hearing loss face hearing difficulties in daily life. The causes of age-related hearing loss are complex and include changes in peripheral hearing, central processing, and cognitive-related abilities. Furthermore, the factors by which aging relates to hearing loss via changes in auditory processing ability are still unclear. In this cross-sectional study, we evaluated 27 older adults (over 60 years old) with age-related hearing loss, 21 older adults (over 60 years old) with normal hearing, and 30 younger subjects (18-30 years old) with normal hearing. We used the outcome of the upper-threshold test, including the time-compressed threshold and the speech recognition threshold in noisy conditions, as a behavioral indicator of auditory processing ability. We also used electroencephalography to identify presbycusis-related abnormalities in the brain while the participants were in a spontaneous resting state. The time-compressed threshold and speech recognition threshold data indicated significant differences among the groups. In patients with age-related hearing loss, information masking (babble noise) had a greater effect than energy masking (speech-shaped noise) on processing difficulties. In terms of resting-state electroencephalography signals, we observed enhanced frontal lobe (Brodmann's area, BA11) activation in the older adults with normal hearing compared with the younger participants with normal hearing, and greater activation in the parietal (BA7) and occipital (BA19) lobes in the individuals with age-related hearing loss compared with the younger adults. Our functional connection analysis suggested that compared with younger people, the older adults with normal hearing exhibited enhanced connections among networks, including the default mode network, sensorimotor network, cingulo-opercular network, occipital network, and frontoparietal network. These results suggest that both normal aging and the development of age-related hearing loss have a negative effect on advanced auditory processing capabilities and that hearing loss accelerates the decline in speech comprehension, especially in speech competition situations. Older adults with normal hearing may have increased compensatory attentional resource recruitment represented by the top-down active listening mechanism, while those with age-related hearing loss exhibit decompensation of network connections involving multisensory integration.

Reliability and validity of the mandarin version of the tinnitus primary function questionnaire: A preliminary observational study.

Tinnitus is a prevalent condition among different populations. As the nature of tinnitus is subjective, self-reported measures have been validated and utilized to assess psychometric properties of tinnitus patients. Without exception, Chinese clinicians have administered these measures to patients in mainland China after cross-cultural adaptation. However, shortcomings of these Mandarin measures limited the widespread use of them. Measures which can be fully adapted to the context of Chinese tinnitus patients are still needed. The objective of this study was to evaluate the reliability and validity of the Mandarin Tinnitus Primary Function Questionnaire (TPFQ-M) in a Chinese population.In this observational questionnaire study, we recruited 350 subjects with primary tinnitus from hearing clinics of West China Hospital and administered the TPFQ-M, Mandarin Tinnitus Handicap Inventory (THI-M), and a systematic hearing test battery.The subjects finished the TPFQ-M within 3 minutes. Exploratory and confirmatory factor analyses demonstrated that a 4-factor model was close to fit. The Cronbach alpha of TPFQ-M was 0.925, and test-retest reliability was reasonable with a 7-day test interval (ICC = 0.857, P < .001; 95% CI: 0.764-0.915). Test-retest reliabilities of subdomains were not parallel to each other, with 0.612 for Emotion, 0.766 for Sleep, 0.860 for Concentration, and 0.897 for Hearing. The convergent validity of TPFQ-M compared to the THI-M was moderate (r = 0.705, P < .001; 95% CI: 0.647-0.754).The TPFQ-M, which shows high internal consistency and good factor structure, is simple and relatively easy to administer in busy clinics. Additional in-depth research involving multiple centers in mainland China is warranted.

Effect of CEACAM-1 knockdown in human colorectal cancer cells.

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM-1) is the major antigen of the CD66 cluster of granulocyte differentiation antigens. The present study aimed to assess the biological function of CEACAM-1 on the growth of human colorectal cancer (CRC) cells in vitro. Treatment of cultured CRC HCT-8 cells with CEACAM-1-specific siRNA successfully downregulated CEACAM-1 expression by 61% compared with control cells. The effects of CEACAM-1 downregulation on HCT-8 cell proliferation and apoptosis were then assessed via Cell Counting kit-8 assay and flow cytometry, respectively. The results demonstrated that siRNA-induced CEACAM-1 downregulation significantly inhibited proliferation and increased apoptosis, but had no significant effect on cell cycle progression in HCT-8 cells. Together, these results suggest that CEACAM-1 activity is critical to CRC growth, and thus, CEACAM-1 may be a promising therapeutic target for the treatment of CRC.

Brain-derived neurotrophic factor gene-modified bone marrow mesenchymal stem cells.

The present study aimed to investigate the effects of human brain-derived neurotrophic factor (hBDNF) on the differentiation of bone marrow mesenchymal stem cells (MSCs) into neuron-like cells. Lentiviral vectors carrying the hBDNF gene were used to modify the bone marrow stromal cells (BMSCs) of Sprague-Dawley (SD) rats. The rat BMSCs were isolated, cultured and identified. A lentivirus bearing hBDNF and enhanced green fluorescent protein (eGFP) genes was subcultured and used to infect the SD rat BMSCs. The expression of eGFP was observed under a fluorescence microscope to determine the infection rate and growth of the transfected cells. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) was used to detect the proliferation rate of cells following transfection. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were used to detect the expression levels of hBDNF. Differentiation of neuron-like cells was induced in vitro and the differentiation rate of the induced neural-like cells was compared with that in control groups and analyzed statistically. In the cultured cells, flow cytometry demonstrated positive expression of cluster of differentiation (CD)90 and CD44, and negative expression of CD34 and CD45. The proliferation rate of the rat BMSCs increased following gene transfection. The expression of hBDNF-eGFP was detected in the BMSCs of the experimental group. The differentiation rate of hBDNF-modified cells into neuron-like cells in the experimental group was higher compared with that in empty plasmid and untransfected negative control groups. The difference was statistically significant (P<0.05). Thus, BDNF gene transfection is able to promote the differentiation of BMSCs into neuron-like cells. BDNF may play an important role in the differentiation of MSCs into neuron-like cells.