Concomitant Ipsilateral Knee Pain Is Associated With Worse Preoperative Functional Status and Short-Term Outcomes After Hip Arthroscopy in Patients With Femoroacetabular Impingement Syndrome.

PURPOSE: (1) To determine the effect of concomitant ipsilateral knee pain (IKP) on short-term outcomes after hip arthroscopic treatment of femoroacetabular impingement syndrome (FAIS) and (2) to determine whether IKP would improve with surgery. METHODS: Data between September 2021 and May 2022 were reviewed. Patients with a diagnosis of FAIS who underwent hip arthroscopy with a minimum of 1-year follow-up were included. The exclusion criteria were prior ipsilateral hip or knee surgery, hip Tönnis grade greater than 1, knee Kellgren-Lawrence grade greater than 2, hip conditions (avascular necrosis, Legg-Calvé-Perthes disease, pigmented villonodular synovitis, osteoid osteoma, synovial chondromatosis, and developmental dysplasia of the hip), and spine diseases. All patients underwent knee magnetic resonance imaging preoperatively. Preoperative and short-term (1-year) patient-reported outcomes were collected, consisting of the Hip Sports Activity Scale score, weekly sports participation, modified Harris Hip Score (mHHS), 12-component International Hip Outcome Tool (iHOT-12) score, and visual analog pain scale (VAS) scores for the hip and the ipsilateral knee. The percentages of patients achieving the minimal clinically important difference and patient acceptable symptom state (PASS) for the mHHS and iHOT-12 score were calculated. Multivariate regression analysis was performed to determine the effect of IKP severity on postoperative outcomes. Subgroup analysis was performed between patients with IKP alleviation and those without IKP alleviation. RESULTS: Among the 107 patients included, 47 presented with preoperative IKP. Compared with patients without IKP, the IKP cohort had comparable knee structural abnormalities (all with P > .05). Still, the IKP cohort showed inferior preoperative values for the mHHS (P = .003), iHOT-12 score (P = .016), hip VAS score (P = .001), and weekly sports participation (P = .039). Postoperatively, the IKP cohort had a lower mHHS (P = .046), lower iHOT-12 score (P = .037), and lower hip VAS score (P = .003) and were less likely to achieve the PASS for the mHHS (P = .021) and iHOT-12 score (P = .049). Patients with higher knee VAS scores were less likely to achieve the PASS for the mHHS (odds ratio, 0.61; P = .023). Within the IKP group, the knee VAS score improved from 2.3 to 1.0 (P < .001). Patients with alleviated IKP showed superior postoperative iHOT-12 scores (P = .038) compared with patients with persistent IKP. CONCLUSIONS: Concomitant IKP at baseline negatively affected preoperative status and short-term clinical outcomes after arthroscopic treatment of FAIS. Patients with IKP were less likely to meet clinical thresholds. Most patients achieved IKP alleviation postoperatively, which was associated with superior clinical outcomes. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

The Combined Use of Platelet-Rich Plasma Clot Releasate and Allogeneic Human Umbilical Cord Mesenchymal Stem Cells Rescue Glucocorticoid-Induced Osteonecrosis of the Femoral Head.

Glucocorticoid-induced osteonecrosis of the femoral head (ONFH) is a refractory disease. The treatment options for ONFH, especially nonsurgical ones, merit further investigation. To evaluate the combinatorial therapeutic effects of platelet-rich plasma clot releasate (PRCR) and umbilical cord mesenchymal stem cells (UC-MSCs) on glucocorticoid-induced ONFH, a dexamethasone (DEX)-treated cell model and a high-dose methylprednisolone (MPS)-treated rat model were established. Cell counting kit-8 (CCK-8) assay was performed in vitro to determine the optimum dosage of PRCR for UC-MSC viability. The effects of PRCR, UC-MSCs, and PRCR + UC-MSCs on cell viability, apoptosis, migration, and differentiation capacities of DEX-treated bone marrow mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cell (HUVECs) were explored via Transwell assays. Western blotting was conducted to evaluate the expression levels of RUNX2, VEGF, caspase-3, and Bcl-2 in the coculture systems. Ultrasound-guided intra-articular PRCR, UC-MSCs, and PRCR + UC-MSC injections were performed on the ONFH model rats. Microcomputed tomography, histological and immunohistochemical analyses, tartrate-resistant acid phosphatase (TRAP) staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to assess the therapeutic effects of PRCR and UC-MSCs on bone loss and necrosis induced by high-dose MPS. Results of this study revealed that the in vitro application of PRCR, UC-MSCs, and PRCR + UC-MSCs reversed the impaired proliferation and migration capacities and resisted apoptosis of BMSCs and HUVECs induced by DEX. Moreover, the PRCR and UC-MSC application significantly improved the alkaline phosphatase (ALP) and alizarin red (ALR) staining of BMSCs and tube formation capacity of HUVECs and promoted the protein expression of RUNX2 in BMSCs and VEGF in HUVECs. Similarly, in the ONFH rat model, the intra-articular injection of UC-MSCs and PRCR improved the subchondral bone mass parameters; promoted the expression of ALP, RUNX2, and VEGF; suppressed osteoclast overactivity; and resisted cell apoptosis. The combination of PRCR and UC-MSCs shows promising therapeutic effects in treating glucocorticoid-induced ONFH. The current study provides important information on intra-articular therapy, paving the way for the clinical management of ONFH in the future.

Comparisons of Ultrasound-Guided Platelet-Rich Plasma Intra-Articular Injection and Extracorporeal Shock Wave Therapy in Treating ARCO I-III Symptomatic Non-Traumatic Femoral Head Necrosis: A Randomized Controlled Clinical Trial.

BACKGROUND AND OBJECTIVE: Osteonecrosis of the femoral head (ONFH) is a devastating disease, and there is some evidence that extracorporeal shock wave therapy (ESWT) and intra-articular platelet-rich plasma (PRP) injection might alleviate pain and improve joint function in individuals with ONFH. The objective of this study was to compare the effectiveness and safety of PRP and ESWT in symptomatic ONFH patients. METHODS: A total of 60 patients aged 40-79 with unilateral ONFH at Association Research Circulation Osseous (ARCO) stages I, II, and III were randomly assigned to the PRP (N=30) or the ESWT group (N=30). Four treatment sessions were provided in both groups. Assessments were performed at baseline, and 1-, 3-, 6-, and 12-month. Primary outcomes were measured by the visual analogue scale (VAS), and pressure pain thresholds (PPTs). Secondary outcomes were assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Harris Hip Score (HHS), and magnetic resonance imaging (MRI). The linear mixed-model analysis was used to evaluate the differences between groups and within groups and the "group by time" interaction effects. RESULTS: There were significant differences between groups in terms of changes over time for VAS, PPTs, WOMAC, and HHS since 3-month and maintained up to 12-month (P<0.05, except for PPTs at 12-month). The simple main effects showed that the patients in PRP group had greater improvements in VAS (mean difference = -0.82, 95% CI [-1.39, -0.25], P=0.005), WOMAC (mean difference = -4.19, 95% CI [-7.00, -1.37], P=0.004), and HHS (mean difference = 5.28, 95% CI [1.94, 8.62], P=0.002). No related adverse events were reported. CONCLUSION: This study supported the effectiveness and safety of both the PRP injection and ESWT in treating ONFH patients. For symptomatic patients with ONFH, intra-articular PRP injection appeared superior to ESWT in pain relief and functional improvement.

Therapeutic effect of platelet-rich plasma on glucocorticoid-induced rat bone marrow mesenchymal stem cells in vitro.

BACKGROUND: Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is a progressive and disabling disease caused by long-term or high-dose glucocorticoid use. Decreased osteogenesis and proliferation of bone marrow mesenchymal stem cells (BMSCs) are the main pathogenesis of GIONFH. Platelet-rich plasma (PRP) has been shown to play a promising role in bone regeneration. However, the effects of PRP on glucocorticoid-induced BMSCs inhibition remains elusive. The objective of this study was to explore whether PRP could improve the in vitro biological activities of BMSCs inhibited by high-dose glucocorticoid in vitro. METHODS: In this study, a dexamethasone (Dex)-induced in vitro cell model was established. The effects of PRP on proliferation, migration, cell cycle and apoptosis of rat BMSCs induced with high-dose Dex compared to BMSCCTRL, using CCK-8 assay, transwell, flow cytometry and TUNEL assay, respectively. We further performed the alkaline phosphatase (ALP) and alizarin red (ALR) staining to explore the influence of PRP on osteogenic differentiation. Western Blot was used to detect the expression of Bcl-2, Caspase-3, RUNX2 apoptosis, and osteogenic-related proteins. RESULTS: We observed increased apoptosis rate and Caspase-3 expression, and the decreased migration and osteogenic differentiation, and down-regulation of RUNX-2 and Bcl-2 expression in Dex-induced BMSCs. PRP could reverse these inhibitory effects of Dex, and enhance the BMSCs proliferation, migration, and osteogenic ability in vitro. CONCLUSION: Our vitro study showed that PRP significantly protected BMSCs from Dex-induced apoptosis, and further promoted BMSCs proliferation, migration, and osteogenic differentiation. This study provides a scientific basis for the prevention and treatment of GIONFH with PRP. Meanwhile, it also lays the foundation for the application of PRP in other musculoskeletal diseases.

Comparison studies of ultrasound-guided botulinum toxin injection and balloon catheter dilatation in the treatment of neurogenic cricopharyngeal muscle dysfunction.

BACKGROUND: Cricopharyngeal muscle dysfunction (CPD) management has been challenging in clinical practice. OBJECTIVE: To compare the efficacy and safety of ultrasound-guided botulinum toxin injection and balloon catheter dilatation in treating CPD. METHODS: Forty patients with CPD were randomly divided into two groups, namely the botulinum toxin injection group (BTX group) and balloon dilatation group (BD group). Patients in the BTX group received a single ultrasound-guided injection of 50 units of botulinum toxin type A, while the BD group received dilatation therapy five times per week, consecutively for two weeks. Relative opening percentage of the upper esophageal sphincter (UES), the penetration-aspiration scale (PAS), and the Dysphagia Outcome Severity Scale (DOSS) were evaluated by a videofluoroscopic swallowing study (VFSS) at baseline, 1-month, and 3-months posttreatment. The Functional Oral Intake Scale (FOIS) and Standardized Swallowing Assessment (SSA) were also used to evaluate participants' swallowing function at baseline and the 1-week, 2-week, 1-month, and 3-month follow-ups. RESULTS: A generalized estimating equation (GEE) model revealed the significant main effect for time in UES, PAS, DOSS, FOIS, and SSA compared to baseline (P <0.05), while no group-by-time interactions (except for the PAS assessment) or main effect for treatment was detected among the above multiple variances. No systematic complications or severe adverse effects were noted. CONCLUSION: Both ultrasound-guided botulinum toxin type A injections and balloon dilatation therapy have been proven as safe and effective treatments for CPD patients. Future clinical trials with longer follow-up periods and more participants are warranted.

Accuracy and Feasibility of Ultrasound-Guided Intra-articular Injection of the Rat Hip Joint.

Intra-articular injection is frequently used as an effective diagnostic and treatment tool for hip joint diseases. However, the underlying treatment mechanism remains unclear because of a lack of experimental animal models. A challenge facing researchers is how to accurately and consistently perform injections involving animal hip joints. The purpose of this study, then, was to establish an ultrasound (US)-guided intra-articular (IA) injection technique using rat hip joints and to evaluate its accuracy and feasibility versus a fluoroscopy (FL)-guided technique. For this study, 20 US-guided and 20 FL-guided IA injections were administered to separate groups of Sprague-Dawley rats. For each procedure, 50 µL of iohexol was injected into the hip joint using a 25G needle. The US-guided injections were performed using a linear probe, and the FL-guided IA injections were performed using C-arm X-ray fluoroscopy. All injections were verified by computed tomography imaging. The number of successful injections and needle repositions per injection, as well as operating times, were recorded, and the rats were observed for complications for 10 d after the injections. Statistical analysis was used to compare US-guided and FL-guided techniques with significance set at p < 0.05. The success rate was markedly higher for the US-guided interventions (90%) than for the FL-guided interventions (75%) (p<0.05). The intervention time was shorter in the US-guided group (95.95 ± 8.376 s) than in the FL-guided group (110.70 ± 20.236 s) (p < 0.05), and the median number of needles repositioned per injection in the US-guided group (1.20 ± 0.41) was notably less than that in the FL-guided group (1.60 ± 0.68) (p < 0.05). A puncture site hematoma was noted in two rat hips (10%) the day after injection in the FL-guided group. Overall, the study indicated that ultrasound-guided intra-articular injection of the hip is a feasible, accurate and safe method for use in rats. This makes it a promising tool for diagnosing coxofemoral pain, producing hip osteoarthritis animal models and administering intra-articular medication.

Platelet-rich plasma for the treatment of adolescent late-stage femoral head necrosis: a case report.

Osteonecrosis of femoral head (ONFH) is a disabling and intractable disease. Previous studies reported the increasing failure rates of total hip arthroplasty in younger patients, thus there should be special considerations for the adolescents. In this paper, we present a case of an adolescent female with late-stage glucocorticoid-induced ONFH (according to the Association Research Circulation Osseous classification system, Association Research Circulation Osseous IV). The patient received five consecutive ultrasound-guided intra-articular injections of platelet-rich plasma, and the therapeutic effects were assessed by visual analog scale, joint range of motion, Western Ontario and McMaster Universities Osteoarthritis Index, Harris Hip Score and magnetic resonance imaging. At 9-month follow-up, clinical and radiological reassessments demonstrated favorable outcomes. This case highlights the therapeutic potential of platelet-rich plasma injections for the late-stage ONFH, especially for adolescent patients.

Randomized Trial on Comparison of the Efficacy of Extracorporeal Shock Wave Therapy and Dry Needling in Myofascial Trigger Points.

OBJECTIVE: The aim of the study was to compare the efficacy of radial extracorporeal shock wave therapy and dry needling in the treatment of myofascial trigger points in the upper trapezius muscle. DESIGN: A total of 65 patients with myofascial trigger points were randomly divided into extracorporeal shock wave therapy group (n = 32) and dry needling group (n = 33). Patients received 3 wks of treatment at 1-wk intervals (in both groups). Visual analog scale, pressure pain threshold, Neck Disability Index, and shear modulus were evaluated before treatment, immediately after the first therapy, 1 mo, and 3 mos after the completion of the third therapy. RESULTS: Significant improvements of visual analog scale, pressure pain threshold, and Neck Disability Index scores were observed at all time points after treatment (P < 0.01) in both treatment groups. The shear modulus of myofascial trigger points was reduced in both dry needling group (P < 0.05) and extracorporeal shock wave therapy group (P < 0.01) immediately after the first treatment. Significant reductions in shear modulus were maintained up to 3-mo posttreatment in both groups (P < 0.01). There were no significant differences between the radial extracorporeal shock wave therapy group and dry needling group. CONCLUSIONS: The extracorporeal shock wave therapy is as effective as dry needling for relieving pain, improving function, and reducing shear modulus for patients with myofascial trigger points after a series of three treatments.

Using an Internet-Based Hospital to Address Maldistribution of Health Care Resources in Rural Areas of Guangdong Province, China: Retrospective and Descriptive Study.

BACKGROUND: Health care maldistribution is a long-term problem in China. Telemedicine is an efficient way to deliver medical resources to remote areas; however, there are few studies on the effectiveness and challenges in providing health care from rural to urban areas in China. OBJECTIVE: The objective was to describe the effectiveness and challenges of telemedicine for providing health care from Guangzhou to rural areas in Guangdong Province. METHODS: We designed surveys and conducted them immediately after the consultation and 2-4 weeks later. Data were collected from June 2015 to May 2016 including patients' demographic features, patient satisfaction, medicine effect, patient compliance, acceptability of prescription expenses, patients' desire to revisit the department, the top 10 diseases, and self-reported difficulties in telemedicine experience. The monthly average prescription expense was described using a line chart. The monthly consultation and prescription, as well as monthly prescriptions of Western medicines and herbs, were described using a bar chart. RESULTS: Women comprised majority (45,386/67,740, 67.00%) of participants and men comprised the minority (22,354/67,740, 33.00%). The top 3 diseases were upper respiratory diseases (12,371/36,311, 34.07%), laryngopharyngitis (4938/36,311, 13.60%), and menstrual disorders (4669/36,311, 12.86%). The monthly prescription for Western medicine was much more than that for Chinese herbs. The annual average medicine expense per prescription was 62.9 ¥. The participants' perception of expense was acceptable (8775/12,450, 70.48%), mostly acceptable (2497/12,450, 20.01%), accepted but somewhat expensive (980/12,450, 7.9%), and unacceptable because of high cost (198/12,450, 1.6%). The surveys on patient satisfaction demonstrated very satisfied (55,687/67,740, 82.21%), satisfied (5891/67,740, 8.70%), basic satisfaction (3561/67,740, 5.26%), dissatisfaction (1454/67,740, 2.15%), and no comment (1147/67,740, 1.69%). Participants reported their treatment outcome as follows: full recovery (5008/12,450, 40.22%), recovering (4873/12,450, 39.14%), no effect (2153/12,450, 17.29%), or worsening (416/12,450, 3.3%). Approximately 89.01% (20,240/22,740) of participants will revisit the department, whereas 10.99% (2500/22,740) will not. Most patients complied with the doctors' advice completely (5430/10,290, 52.77%), whereas the rest reported partial compliance (3684/10,290, 35.80%) or no compliance at all (1176/10,290, 11.43%). The participants reported poor computer skills (4980/22,740, 21.90%), transportation inconvenience (4670/22,740, 20.50%), unstable internet connection (3820/22,740, 16.80%), language barriers (3708/22,740, 16.30%), medication and medical hardware shortage (2459/22,740, 10.82%), tiring commute (2068/22,740, 9.08%), family care burdens (679/22,740, 3.0%), and other unclassified difficulties (356/22,740, 1.6%) as difficulties in using telemedicine. CONCLUSIONS: Telemedicine has a wide disease spectrum, similar to ordinary medicine in China. It saves costs, has high patient satisfaction and price acceptability, and can relieve disease and syndromes. However, certain problems need to be resolved. Telemedicine could be a feasible approach to address the health care maldistribution in rural China. This study may provide useful information for policy making and guidance for further telemedicine practice in China and other developing countries.

Upregulation of CCL2 via ATF3/c-Jun interaction mediated the Bortezomib-induced peripheral neuropathy.

Bortezomib (BTZ) is a frequently used chemotherapeutic drug for the treatment of refractory multiple myeloma and hematological neoplasms. The mechanism by which the administration of BTZ leads to painful peripheral neuropathy remains unclear. In present study, we found that application of BTZ at 0.4 mg/kg for consecutive 5 days significantly increased the expression of CCL2 in DRG, and intrathecal administration of neutralizing antibody against CCL2 inhibited the mechanical allodynia induced by BTZ. We also found an increased expression of c-Jun in DRG, and that inhibition of c-Jun signaling prevented the CCL2 upregulation and mechanical allodynia in the rats treated with BTZ. Furthermore, the results with luciferase assay in vitro and ChIP assay in vivo showed that c-Jun might be essential for BTZ-induced CCL2 upregulation via binding directly to the specific position of the ccl2 promoter. In addition, the present results showed that an upregulated expression of ATF3 was co-expressed with c-Jun in the DRG neurons, and the enhanced interaction between c-Jun and ATF3 was observed in DRG in the rats treated with BTZ. Importantly, pretreatment with ATF3 siRNA significantly inhibited the recruitment of c-Jun to the ccl2 promoter in the rats treated with BTZ. Taken together, these findings suggested that upregulation of CCL2 resulting from the enhanced interaction between c-Jun and ATF3 in DRG contributed to BTZ-induced mechanical allodynia.

Running exercise alleviates pain and promotes cell proliferation in a rat model of intervertebral disc degeneration.

Chronic low back pain accompanied by intervertebral disk degeneration is a common musculoskeletal disorder. Physical exercise, which is clinically recommended by international guidelines, has proven to be effective for degenerative disc disease (DDD) patients. However, the mechanism underlying the analgesic effects of physical exercise on DDD remains largely unclear. The results of the present study showed that mechanical withdrawal thresholds of bilateral hindpaw were significantly decreased beginning on day three after intradiscal complete Freund's adjuvant (CFA) injection and daily running exercise remarkably reduced allodynia in the CFA exercise group beginning at day 28 compared to the spontaneous recovery group (controls). The hindpaw withdrawal thresholds of the exercise group returned nearly to baseline at the end of experiment, but severe pain persisted in the control group. Histological examinations performed on day 70 revealed that running exercise restored the degenerative discs and increased the cell densities of the annulus fibrosus (AF) and nucleus pulposus (NP). Furthermore, immunofluorescence labeling revealed significantly higher numbers of 5-bromo-2-deoxyuridine (BrdU)-positive cells in the exercise group on days 28, 42, 56 and 70, which indicated more rapid proliferation compared to the control at the corresponding time points. Taken together, these results suggest that running exercise might alleviate the mechanical allodynia induced by intradiscal CFA injection via disc repair and cell proliferation, which provides new evidence for future clinical use.

Cross-cultural adaptation, reliability, and validity of the Chinese version of the STarT Back Screening Tool in patients with low back pain.

STUDY DESIGN: Translation and psychometric testing. OBJECTIVE: The study aims to investigate the reliability and validity of the Chinese version of the STarT Back Screening Tool (STarT) in Chinese-speaking patients with low back pain (LBP) after translation and cultural adaptation. SUMMARY OF BACKGROUND DATA: To date, no previous studies exist on the translation process and validation of the Chinese version of the STarT. METHODS: The procedure of translation, which included 6 stages, was performed according to the current recommended guidelines. Psychometric testing included face validity, test-retest reliability, and discriminant validity. A total of 307 patients completed a questionnaire booklet containing the Chinese version of the STarT, Roland-Morris Disability Questionnaire, Coping Strategies Questionnaire, Tampa Scale for Kinesiophobia-17, and Hospital Anxiety and Depression Scale. Seventy-four randomly selected patients were asked to finish the STarT a second time within 24 to 48 hours. The demographic characteristics and outcomes of psychometric testing were compared with the original English cohort. RESULTS: No items of the final version had reported ambiguity after the face validation and no floor or ceiling effects were noted. The intraclass correlation coefficient was 0.933 (95% confidence interval, 0.896-0.957), demonstrating very good reliability. Discriminant validity was established, with area under curve results in the range from 0.751 to 0.893 (95% confidence interval, 0.697-0.930) in the Chinese cohort compared with 0.840 to 0.925 (95% confidence interval, 0.772-0.948) in the original English cohort. CONCLUSION: The results confirm the successful translation and adaptation of the STarT into Chinese, with appropriate reliability and validity. Therefore, this version can be recommended for clinical and research use for Chinese patients with LBP.

Transport of glial cell line-derived neurotrophic factor into liposomes across the blood-brain barrier: in vitro and in vivo studies.

Glial cell line-derived neurotrophic factor (GDNF) was encapsulated into liposomes in order to protect it from enzyme degradation in vivo and promote its permeability across the blood-brain barrier (BBB). In this study, GDNF conventional liposomes (GDNF-L) and GDNF target sterically stabilized liposomes (GDNF-SSL-T) were prepared. The average size of liposomes was below 90 nm. A primary model of BBB was established and evaluated by transendothelial electrical resistance (TEER) and permeability. This BBB model was employed to study the permeability of GDNF liposomes in vitro. The results indicated that the liposomes could enhance transport of GDNF across the BBB and GDNF-SSL-T had achieved the best transport efficacy. The distribution of GDNF liposomes was studied in vivo. Free GDNF and GDNF-L were eliminated rapidly in the circulation. GDNF-SSL-T has a prolonged circulation time in the blood and favorable brain delivery. The values of the area under the curve (AUC(0-1 h)) in the brain of GDNF-SSL-T was 8.1 times and 6.8 times more than that of free GDNF and GDNF-L, respectively. These results showed that GDNF-SSL-T realized the aim of targeted delivery of therapeutic proteins to central nervous system.

Alumina nanoparticles alter rhythmic activities of local interneurons in the antennal lobe of Drosophila.

The special physical and chemical properties of nanomaterials open up new capabilities and functions. However, concerns have been raised about the risks produced by nanoparticles, their potential to cause undesirable effects, such as contamination of the environment and other adverse effects. In this study, we used Drosophila as a model organism to explore the effects of nano-alumina on the central nervous system. We focused on the rhythmic activities in the antennal lobe of Drosophila using patch clamps to record the electrophysiological activities. We found that 15 min after application of alumina nanoparticles, the average frequencies of spontaneous activities were significantly decreased compared with control groups (0.65 ± 0.13 Hz, 0.34 ± 0.07 Hz, *p < 0.05). These results indicated that nano-alumina might have adverse effects on the central nervous system in Drosophila.