[Estimating the distribution of COVID-19 incubation period by interval-censored data estimation method]

Objectives: The COVID-19 has been the public health issues of global concern, but the incubation period was still under discussion. This study aimed to estimate the incubation period distribution of COVID-19. Methods: The exposure and onset information of COVID-19 cases were collected from the official information platform of provincial or municipal health commissions. The distribution of COVID-19 incubation period was estimated based on the Log- normal, Gamma and Weibull distribution by interval-censored data estimation method. Results: A total of 109 confirmed cases were collected, with an average age of 39.825 years. The median COVID-19 incubation period based on Log-normal, Gamma, and Weibull distribution were 4.958 (P(25)-P(75): 3.472-7.318) days, 5.083 (P(25)-P(75): 3.511-7.314) days, and 5.695 (P(25)-P(75): 3.675-7.674) days, respectively. Gamma distribution had the largest log-likelihood result. Conclusions: The distribution of COVID-19 incubation period followed the Gamma distribution, and the interval-censored data estimation method can be used to estimate the incubation period distribution.

[Study on the Diet and Hygiene Society]

The establishment of the Diet and Hygiene Society was based on the starting point of improving the diet and health habits of the Chinese people, and soon it was involved in a broader public health field with the changes of the times. Its purpose was to "improve food, research hygiene and avoid illness, so as to achieve longevity" . The society advocated vegetarianism and set up a vegetarian restaurant. It publicized "cutting queue but not changing clothes into western style" , which set off the trend of queue cutting in Shanghai. It participated in the prevention of plague in Shanghai, which has reconciled the conflict between Chinese people and foreign officials and has promoted the independent quarantine of Chinese. Discouraging people from smoking cigarettes was considered beneficial for keeping healthy and reducing the trade deficit.

SAT0421 GUSELKUMAB DEMONSTRATED AN INDEPENDENT TREATMENT EFFECT ON FATIGUE AFTER ADJUSTMENT FOR CLINICAL RESPONSE (ACR20) IN PATIENTS WITH PSORIATIC ARTHRITIS: RESULTS FROM PHASE-3 TRIALS DISCOVER 1 & 2

Background:

DISCOVER 1 and 2 are phase-3 trials of guselkumab (GUS, a monoclonal antibody that specifically binds the p19-subunit of IL-23) in patients with psoriatic arthritis (PsA). In both trials, treatment with GUS led to significantly more improvement than placebo (PBO) in the primary endpoint (ACR20) as well as in other measures of arthritis and psoriasis at week (W) 24.1,2

Objectives:

To evaluate the effect of GUS on fatigue in DISC 1 & 2 using the patient reported outcome (PRO) FACIT-Fatigue, which has demonstrated content validity and strong psychometric properties in clinical trials.3

Methods:

DISC 1 & 2 enrolled patients with active PsA, despite nonbiologic DMARDS and/or NSAIDS, who were mostly biologic naïve except for ~30% of patients in DISC 1 who had received 1-2 TNFi. Patients were randomized (1:1:1) in a blinded fashion to subcutaneous GUS 100 mg at W0 and W4 then every (q) 8W, to GUS 100 mg q4W, or to matching PBO. Concomitant treatment with select non-biologic DMARDS, oral corticosteroids, and NSAIDs was allowed. The FACIT-Fatigue is a 13-item PRO instrument assessing fatigue and its impact on daily activities and function over the past seven days, with a total score ranging from 0 to 52, higher score denoting less fatigue. A change of ≥4 points is identified as clinically meaningful.3Change from baseline in FACIT-Fatigue was analyzed using MMRM (Figure). Independence of treatment effect on FACIT-Fatigue from effect on ACR20 was assessed using Mediation Analysis4(Table) to estimate the natural direct effect (NDE) and natural indirect effect (NIE) mediated by ACR20 response.

Results:

At baseline in DISC 1 & 2, the mean FACIT-fatigue scores (SD) were 30.4 (10.4) and 29.7 (9.7), respectively, indicating moderate to severe fatigue. In both DISCOVER 1 & 2 trials, treatment with GUS led to improvements in FACIT-Fatigue scores compared with PBO as early as W8 (Figure). 54%-63% of GUS patients compared with 35%-46% of PBO patients achieved clinically meaningful improvement (≥4 points) in FACIT-Fatigue (P≤0.003). Mediation analysis revealed that the independent treatment effects on fatigue after adjustment for ACR20 response (Natural Direct Effect [NDE], Table) were 12-36% in the q8W GUS dosing group and 69% -70% in the q4W GUS group.

Conclusion:

In 2 phase-3 trials, treatment with GUS of patients with active PsA led to significant improvements compared to PBO in fatigue, including substantial effects on FACIT-Fatigue that were independent of the effects on ACR 20, especially for the q4W dosing group.

References:

[1]Deodhar et al. ACR 2019. Abstract #807. Arthr Rheumatol. 2019;71 S10: 1386

[2]Mease et al. ACR 2019. Abstract # L13. Arthr Rheumatol. 2019;71 S10:5247

[3]Cella et al. Journal of Patient-Reported Outcomes. 2019;3:30

[4]Valeri et al. Psychologic Meth. 2013;18:137

Table.

Mediation Analysis of the Effect of ACR 20 Response on Change from Baseline in FACIT-Fatigue Score at Week 24

EffectGUS 100 mg q8W vs. PBOEstimate (95% CI)GUS 100 mg q4W vs. PBOEstimate (95% CI)DISCOVER 1NDE0.36 (-1.7, 2.4)2.60 (0.6, 4.5)*NIE2.75 (1.4, 4.3)*1.20 (0.3, 2.3)*Total Effect3.12 (1.0, 5.2)*3.79 (1.9, 5.4)*Proportion Independent11.7%68.5%Proportion Mediated88.3%31.5%DISCOVER 2NDE1.44 (-0.1, 3.0)2.49 (1.0, 4.1)*NIE2.53 (1.6, 3.6)*1.09 (0.4, 1.9)*Total Effect3.97 (2.4, 5.5)*3.58 (2.1, 5.0)*Proportion Independent36.3%69.7%Proportion Mediated63.7%30.3%

*P vs placebo<0.02

NDE=Natural Direct Effect (effect on FACIT-F beyond effect on ACR20), NIE=Natural Indirect Effect (effect on FACIT-F mediated by ACR20)

Mediation analysis4used linear and logistics regression models with Bootstrapping method

Acknowledgments:

None

Disclosure of Interests:

Philip Helliwell: None declared, Proton Rahman Grant/research support from: Janssen and Novartis, Consultant of: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, and Pfizer., Speakers bureau: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, Pfizer, Atul Deodhar Grant/research support from: AbbVie, Eli Lilly, GSK, Novartis, Pfizer, UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myer Squibb (BMS), Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB, Speakers bureau: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myer Squibb (BMS), Eli Lilly, GSK, Janssen, Novartis, Pfizer, UCB, Alexa Kollmeier Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC, Elizabeth C Hsia Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC, Bei Zhou Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC, Xiwu Lin Employee of: Janssen Research & Development, LLC, Chenglong Han Employee of: Janssen Research & Development, LLC, Philip J Mease Grant/research support from: Abbott, Amgen, Biogen Idec, BMS, Celgene Corporation, Eli Lilly, Novartis, Pfizer, Sun Pharmaceutical, UCB – grant/research support, Consultant of: Abbott, Amgen, Biogen Idec, BMS, Celgene Corporation, Eli Lilly, Novartis, Pfizer, Sun Pharmaceutical, UCB – consultant, Speakers bureau: Abbott, Amgen, Biogen Idec, BMS, Eli Lilly, Genentech, Janssen, Pfizer, UCB – speakers bureau

Krüppel homologue 1 interacts directly with Hairy and regulates ecdysis in the brown planthopper

Juvenile hormone (JH) plays important roles in the growth and development of insects. JH and its receptor methoprene-tolerant (Met) regulate the expression of transcription factors to control the transcription of downstream genes. The expression of Hairy (Hry) and Krüppel homologue 1 (Kr-h1) is regulated by JH and JH receptors. Hry and Kr-h1 are both crucial in mediating JH signalling. However, whether they interact at the gene level in regulating metamorphosis and whether they interact physically at the protein level remain unknown. We used co-immunoprecipitation, glutathione S-transferase pull-down and RNA interference (RNAi) approaches to study the genetic and biochemical interactions of the two proteins Hry and Kr-h1. The results showed that brown planthopper (Nilaparvata lugens) Hry and Kr-h1 interact directly: Hry binds to the N-terminal of Kr-h1, which includes five zinc-finger domains. The RNAi experiment showed that downregulation of Hry reduced the ratio of ecdysis failure caused by knockdown of Kr-h1, indicating that the downregulation of Hry might mitigate ecdysis failure via the downregulation of Kr-h1. The expression of Hry increased significantly when Kr-h1 was downregulated, whereas it did not change significantly when both were downregulated. Our results suggest that the binding of Hry protein with Kr-h1 prevents the N-terminal five zinc-finger domains from binding with DNA, which in turn inactivates the transcription activator or inhibitor function of Kr-h1. Hry could possibly be used as a target for pesticide applications in the future.

Efficacy of recombinant N- and C-terminal derivative of EmIMP1 against E. maxima infection in chickens

1. Immune mapped protein-1 (IMP1) of E. maxima has been identified as a vaccine antigen candidate for E. maxima infection. 2. In the current study, the N- and C-terminal derivative of EmIMP1 were expressed in E. coli and administered to chickens. The antibody response, cell-mediated immune (CMI) response and the protective efficacy of the protein vaccines against E. maxima challenge were evaluated. 3. The results showed that C-terminal derivative of EmIMP1 vaccination could increase weight gain, reduce enteric lesions, and decrease faecal oocysts shedding. Moreover, the C-terminal derivative of EmIMP1 caused reasonable improvement in serum antibodies and the numbers of IFN-γ producing peripheral blood mononuclear cells (PBMC), as compared to the control group. 4. This study demonstrated that the C-terminal derivative of EmIMP1 could be used as a potent immunogenic candidate in the development of subunit vaccines against E. maxima infection.

Effect of spinning on the shape and stability of a pendent drop

Assuming that we wish to measure the surface tension between two liquids by running a pendent drop experiment, we present calculations supporting the case for spinning the drop. For bridges, jets, etc., spinning a heavy fluid surrounded by a lighter fluid is strictly destabilizing. But we find that spinning a drop may be stabilizing and, if this is so, it leads to larger critical volumes, volumes where stability is lost, and thus more accurate measurements of surface tension. There are two observable patterns, one symmetric and the other unsymmetric, at the point of instability. The symmetric pattern leads to larger critical volumes. Our aim is to show how spinning can be used to achieve the symmetric pattern.

[Prognosis analysis of 112 cases with Japanese encephalitis in adults]

Objective: To analyze the improvement of clinical symptoms and recovery of neurological function in adult Japanese encephalitis, and study the prognostic factors. Methods: Follow-up was conducted for 112 hospitalized patients with Japanese encephalitis (JE) in adults at the Department of Neurology of three hospitals in Gansu province from July to October 2016, from July to October 2017, 6 months and 1 year after onset, respectively. The neurological functional recovery was evaluated by modified Ranking Scale (mRS).The influencing factors were analyzed by logistic regression model. Results: Among the 112 adult patients with JE after 1year follow-up, 57% (64/112) were completely recovered (mRS score=0), and 14%(16/112) had mild neurological dysfunction (mRS score=1 or 2 points), 20% (22/112) had moderate to severe neurological dysfunction (mRS score 3 to 5), and 9% (10/112) died. In 102 survivors, decreased consciousness were fully recovered (100%), 75% of the mental and behavior disorders, 64% of cognitive/memory impairment, 71% of language function disorder, 61% of paralysis, 73% of extrapyramidal symptoms were fully recovered, and 92% of the seizures were controlled. Comparison of clinical data of initial on-set between good prognosis group (mRS score≤2, 80 cases) and poor prognosis group (mRS score>2, 32 cases) showed that initial clinical manifestation with seizures, consciousness (GCS score), cerebrospinal fluid pressure, and lesion of MRI involved in midbrain had statistically significant differences (all P<0.05) . Multivariate analysis demonstrated that cerebrospinal fluid (CSF) pressure>250 mmH(2)O and lesion of midbrain in MRI were independent risk factors of poor prognosis in adult patients with JE. Conclusion: JE is an acute and infectious viral encephalitis of the central nervous system with high disability and mortality. Most patients were completely recovered, and some had neurological sequelae. CSF pressure>250 mmH(2)O and lesion of midbrain in MRI are independent risk factors for poor prognosis.

Transinguinal preperitoneal repair of giant inguinoscrotal hernias using Kugel mesh

INTRODUCTION

Giant inguinoscrotal hernias are rarely encountered in clinical settings, and their repair is technically challenging. The aim of this study is to evaluate the efficacy of transinguinal preperitoneal repair (TIPP) of giant inguinoscrotal hernias using Kugel mesh.

METHODS

A retrospective analysis was conducted on 9 patients with 11 giant inguinoscrotal hernias who underwent TIPP repair using Kugel mesh between December 2008 and January 2019. Demographics and perioperative and postoperative data were collected, and the operative experience was summarized.

RESULTS

The patients underwent a successful repair procedure with simultaneous omentectomy but without resection of the other abdominal organs. The median operation time was 120min, the median intraoperative blood loss was 75mL and the median defect area was 72 cm². The median duration for diet restoration was 4 days, and the median postoperative hospital stay was 6 days. The drainage tube placed in the preperitoneal space was removed after a median duration of 5 days, and the drainage tube placed in the distal hernia sac was removed after a median duration of 6 days. Three patients suffered from a postoperative increase in intra-abdominal pressure, while one patient deteriorated into abdominal compartment syndrome accompanied by respiratory dysfunction. No haematomas, seromas, incisional or mesh infections, recurrence or chronic pain occurred during the follow-up period.

CONCLUSIONS

TIPP repair using Kugel mesh is a feasible and effective method for giant inguinoscrotal hernias.

Handgrip Strength and Timed Up-and-Go (TUG) Test are Predictors of Short-Term Mortality among Elderly in a Population-Based Cohort in Singapore

OBJECTIVES

Asian studies on how physical tests predict short-term mortality in elderly are scarce. We assessed handgrip strength and timed-up-and-go (TUG) as such predictors among elderly Chinese in Singapore.

DESIGN

Prospective cohort study.

SETTING

Community-dwelling Chinese elderly in Singapore.

PARTICIPANTS

We used data from 13,789 subjects in the prospective, population-based Singapore Chinese Health Study, who had a mean age of 74 (range 63 to 97) years at time of measurements.

MEASUREMENTS

Subjects underwent assessment for handgrip strength and TUG. They were followed for mortality via linkage with nationwide death registry through 2018.

RESULTS

In multivariable analyses, handgrip strength was inversely associated with risk of mortality in a dose-dependent manner: the hazard ratio (HR) [95% confidence interval (CI)] comparing extreme quartiles was 2.05 (1.44-2.90) (Ptrend<0.001). TUG was positively associated with mortality in a stepwise manner: the HR (95% CI) comparing extreme quartiles was 3.08 (2.17-4.38) (Ptrend<0.001). Compared to those with stronger handgrip and faster TUG, participants who either had weaker handgrip or slower TUG had a significant 1.59 to 2.11 fold increase in risk of mortality; while the HR (95% CI) for those who had both weaker handgrip and slower TUG was 3.93 (3.06-5.05). In time-dependent receiver operating characteristic curves, adding handgrip strength and TUG time to a Cox model containing sociodemographic and lifestyle factors, comorbidities, and body measurements significantly improved the area under the curve for the prediction of mortality from 0.5 to 2 years (P≤0.001).

CONCLUSION

Among elderly in a Chinese population, handgrip strength and TUG test were strong and independent predictors of short-term mortality.

Prevalence and Risk Factors Governing the Loss of Muscle Function in Elderly Sarcopenia Patients: A longitudinal Study in China with 4 Years of Follow-Up

OBJECTIVES

Data regarding the occurrence of risk factors that promote the loss of muscle mass, strength and function in sarcopenia patients in elderly Chinese patients are sparse. Here, we investigated the alterations in muscle mass, function and strength in those with sarcopenia over a 4-year period. We further evaluated the risk factors leading to a loss of grip strength, gait speed and skeletal muscle mass index in sarcopenia patients.

DESIGN

A face-to-face cross-sectional survey.

SETTING AND PARTICIPANTS

The study population consisted of 560 Chinese aged over 59 years.

MEASUREMENTS

Study recordings took places over a four-year period from 2014. Muscle mass was assessed through bioelectrical impedance analysis (BIA) performed on an Inbody720, Biospace. Hand-grip strength and 6 m walking speed were used as measurements of muscle strength and function. Sarcopenia was diagnosed using the Asian Working Group for Sarcopenia criteria (AWGS).

RESULTS

In total, 474 of the elderly residents completed the follow-up. The rates of decreased ASMI, grip strength, and gait speed in the sarcopenia patients increased over the 4-year period. Following multivariate analysis, age was identified as the main risk factor for all the observed decrease, gender was specifically related to the loss of ASMI, stroke was a risk factor for gait speed and sarcopenia. A high BMI was a risk factor for a low gait speed but was protective for a loss of skeletal muscle mass and sarcopenia.

CONCLUSIONS

Age leads to a decline in muscle strength and function. In elderly Chinese patients with sarcopenia, the rates of reduced grip strength, gait-speed and sarcopenia increased. A high BMI was protective against the decline in muscle mass and sarcopenia, but represented a risk factor for low gait speed. Stoke was identified to cause a loss of gait speed in sarcopenia patients.

CKB1 regulates expression of ribosomal protein L10 family gene and plays a role in UV-B response

Plastid casein kinase 2 (CK2), which is a major Ser/Thr-specific enzyme in higher organisms, plays an essential role in plant development and diverse abiotic stresses. CKB1 is a regulatory subunit beta of CK2. To expand our understand of functions of the CKB1 gene in Arabidopsis thaliana, protein changes among wild-type (WT) and CKB1 gain- and loss-of-function mutants were compared. Proteins extracted from the CKB1 knockout mutant and overexpressing mutant were compared with Col-0 plants using 2D-PAGE. Proteins regulated by CKB1 were identified with matrix-assisted laser desorption ionisation time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF), and its transcript was verified by qRT-PCR. Bioinformatics analysis, including gene ontology and protein-protein interaction analysis, were employed. The results of mass spectra and bioinformatics analysis suggest that CKB1 may have functions in regulation of the ribosomal protein L10 (RPL10) family and is involved in ultraviolet-B (UV-B) response. Furthermore, qRT-PCR verification showed CKB1 expression was up-regulated by UV-B stress. The expression levels of five genes in the RPL10 family were reduced in the ckb1 T-DNA insertion mutants, whereas they increased in the CKB1 overexpressing mutants under both normal conditions and UV-B treatment. In conclusion, CKB1 has important functions in UV-B radiation stress. Our study implies that CKB1 positively regulates UV-B radiation stress signalling, possibly through modulating expression of the RPL10 family.

Adjuvant sunitinib in patients with high-risk renal cell carcinoma: safety, therapy management, and patient-reported outcomes in the S-TRAC trial

Background

Adjuvant sunitinib has significantly improved disease-free survival versus placebo in patients with renal cell carcinoma at high risk of recurrence post-nephrectomy (hazard ratio 0.76; 95% confidence interval, 0.59–0.98; two-sided P = 0.03). We report safety, therapy management, and patient-reported outcomes for patients receiving sunitinib and placebo in the S-TRAC trial.

Patients and methods

Patients were stratified by the University of California, Los Angeles Integrated Staging System and Eastern Cooperative Oncology Group performance status score, and randomized (1 : 1) to receive sunitinib (50 mg/day) or placebo. Single dose reductions to 37.5 mg, dose delays, and dose interruptions were used to manage adverse events (AEs). Patients’ health-related quality of life, including key symptoms typically associated with sunitinib, were evaluated with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30).

Results

Patients maintained treatment for 9.5 (mean, SD 4.4) and 10.3 (mean, SD 3.7) months in the sunitinib and placebo arms, respectively. In the sunitinib arm, key AEs occurred ∼1 month (median) after start of treatment and resolved within ∼3.5 weeks (median). Many (40.6%) AEs leading to permanent discontinuation were grade 1/2, and most (87.2%) resolved or were resolving by 28 days after last treatment. Patients taking sunitinib showed a significantly lower EORTC QLQ-C30 overall health status score versus placebo, although this reduction was not clinically meaningful. Patients reported symptoms typically related to sunitinib treatment with diarrhea and loss of appetite showing clinically meaningful increases.

Conclusions

In S-TRAC, AEs were predictable, manageable, and reversible via dose interruptions, dose reductions, and/or standard supportive medical therapy. Patients on sunitinib did report increased symptoms and reduced HRQoL, but these changes were generally not clinically meaningful, apart from appetite loss and diarrhea, and were expected in the context of known sunitinib effects.

Clinical trial registration

ClinicalTrials.gov, NCT00375674.

[Spatial distribution of cancer-related burden in Guangzhou from 2010 to 2013]

Objective: To evaluate the burden and to describe the characteristics of spatial distribution caused by malignant tumors among different administrative areas in Guangzhou from 2010- 2013. Methods: Based on data from the Cancer Registry system and population in Guangzhou in 2010- 2013, disability-adjusted life year (DALY) was assessed on the disease burden of cancer, in accordance with the method used in the Global Burden of Disease study. Results: The crude incidence rates of cancer appeared as 256.22/10(5) in 2010-2011 and 270.04/10(5) in 2012-2013, with the crude mortality rates as 143.17/10(5) and 148.01/10(5), respectively, in Guangzhou. Cancers caused 606 238.95 DALYs in 2010-2011 and 623 763.80 DALYs in 2012-2013 for both sexes and 37.63 and 37.81 person year per 1 000 persons, with the standardized DALY rates as 34.51‰, 34.00‰ respectively. Three administrative districts (Yuexiu, Haizhu and Liwan) were with the largest disease burden of cancers that accounted for 45% of the DALYs for the whole Conghua district, with liver cancer was the leading cancer on DALYs, and tracheal, bronchus and lung cancer ranked the first in the other districts. Conclusions: In Guangzhou, disease burden caused by cancers was both prominently seen in the newly developed urban area and the old districts. It remains an arduous task to continue programs on control and prevention of cancers in this city.

Effect of cephalexin after heterogeneous Fenton-like pretreatment on the performance of anaerobic granular sludge and activated sludge

Effects of Fe₃O₄ NPs heterogeneous Fenton-like pretreatment on the physicochemical properties and microbial community structure of anaerobic granular sludge (AGS) and activated sludge (AS) with cephalexin were investigated. Results showed that the average removal rate of chemical oxygen demand (COD) by the AGS was 80.9%, 85.9%, 90.3% and 91.6%, respectively, at cephalexin without pretreatment, pretreatment with 20% (H₂O₂), 40% (H₂O₂) and 60% (H₂O₂). Compared to the reactor without pretreatment, the COD removal rate increased by 24.14% with 60% (H₂O₂) pretreatment for the AS. Dehydrogenase levels in the AS were 313.05, 351.12, 434.81 and 480.77 mg TF (g·h)^-1, which increased with higher concentrations of the pretreatment. Three-dimensional fluorescence (EEM) spectra analysis showed that the absorption peak intensities of humic acid in soluble microbial products (SMP) decreased in the AGS with increasing pretreatment. In the AGS, the dominant bacterial populations were Levilinea, Litorilinea and Clostridium sensu stricto. Clostridium sensu stricto accounting for 4.35% without pretreatment, while it was as high as 17% when it was pretreated with 60% (H₂O₂). The increase in the proportion of Clostridium sensu stricto was beneficial to the removal of organic pollutants. The pretreatment was also beneficial to the growth of acetic acid producing Methanothrix. For the AS, Gemmobacter were the dominant species, which increased from 6.56% to 32.61% after increasing the pretreatment to 40% (H₂O₂). Furthermore, the microbial capacities of amino acid metabolism and carbohydrate metabolism were enhanced by addition of pretreatment.

[The study of AAV9 expression in cochleae of mice at different ages]

Objective: To determine the extent of transfection and expression of adeno-associated virus (AAV) serotype 9 (AAV9) in the cochleae of mice at different ages. Methods: AAV9-green fluorescent protein (GFP) was inoculated into the cochlea of mice via the round window membrane (RWM) or through cochleostomy at different ages. Four groups were divided according to ages and injection sites: P1SM group, AAV9-GFP was delivered to the scala media by cochleostomy at postnatal day 1; P1RW group, AAV9-GFP was delivered to the scala tympani via RWM at postnatal day 1; P9RW group: AAV9-GFP was injected through RWM at postnatal day 9; and P30RW group, adult mice (P30) were injected through RWM. GFP expression in cochlear whole mount was analyzed and auditory brainstem response (ABR) tests were conducted one month after virus injection (for each animal, only left cochlea was injected and the right side was used as a control). GraphPad Prism 5 statistical software was used for data analysis. Results: All of inner hair cells (IHCs) and most of outer hair cells (OHCs) were transfected via two approaches at P1 injection. There was no significant difference in ABR threshold between injected ears and untreated ears (P>0.05). All of the IHCs and parts of OHCs (69% in apical turn) were transfected via RWM at P9. The strongest GFP expression was observed near the apical turn. Cochlear inoculation via RWM at P30 led to transgene expression in only IHCs. The ABR threshold of injected ears in P9RW group and P30RW group was significantly higher than that of contralateral ears (P<0.01). Conclusions: AAV9 can be highly expressed in the inner and outer hair cells of the cochlea and hearing sensitivity can be preserved if virus injections are performed in neonatal mice. After AAV9 is transfected into the inner ear of adult mice, it is only expressed in the inner hair cells, which leads to the increase of the ABR response threshold of mice. Transfection efficiency is significant higher in neonate mice than in P9 and adult mice.