Both arthroscopic one-step Broström-Gould and Lasso-loop stitch techniques achieved favourable clinical outcomes for chronic lateral ankle instability.

PURPOSE: Both the arthroscopic Broström-Gould and Lasso-loop stitch techniques are commonly used to treat chronic lateral ankle instability (CLAI). The purpose of this study is to introduce an arthroscopic one-step outside-in Broström-Gould (AOBG) technique and compare the mid-term outcomes of the AOBG technique and Lasso-loop stitch technique. METHODS: All CLAI patients who underwent arthroscopic lateral ankle stabilization surgery in our department from 2018 to 2019 were retrospectively enrolled. The patients were divided into two groups according to the surgical methods employed: the AOBG technique (Group A) and the Lasso-loop technique (Group B). The visual analogue scale pain score, American Orthopaedic Foot and Ankle Society ankle hindfoot score, Tegner activity score and Karlsson-Peterson score were evaluated preoperatively and during the follow-up from June to December 2022. The surgical duration, return to sports, sprain recurrence and surgical complications were also recorded and compared. RESULTS: A total of 74 patients (Group A, n = 42; Group B, n = 32) were included in this study with a mean follow-up of 39 months. No statistically significant differences were observed in demographic parameters or follow-up time between the two groups. Postoperative clinical scores indicated a significant improvement (all with p < 0.001) with no significant difference between the two groups (not significant [n.s.]). There was no significant difference in the surgical duration (46.1 vs. 49.7 min, n.s.), return to sports (92.9% vs. 93.8%, n.s.), or sprain recurrence (4.8% vs. 6.3%, n.s.). Only two cases in Group A reported knot irritation (4.8% vs. 0, n.s.), and one case in Group A experienced local skin numbness (0 vs. 3.1%, n.s.), with no significant difference. CONCLUSION: Both the AOBG and Lasso-loop stitch techniques yielded comparable favourable mid-term outcomes and return to sports with a low rate of surgical complications. Both procedures could be feasible strategies for CLAI patients. LEVEL OF EVIDENCE: Level III.

Dietary supplementation with xylooligosaccharides and exogenous enzyme improves milk production, energy utilization efficiency and reduces enteric methane emissions of Jersey cows.

BACKGROUND: Sustainable strategies for enteric methane (CH4) mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure. The present study aimed to investigate the effects of dietary xylooligosaccharides (XOS) and exogenous enzyme (EXE) supplementation on milk production, nutrient digestibility, enteric CH4 emissions, energy utilization efficiency of lactating Jersey dairy cows. Forty-eight lactating cows were randomly assigned to one of 4 treatments: (1) control diet (CON), (2) CON with 25 g/d XOS (XOS), (3) CON with 15 g/d EXE (EXE), and (4) CON with 25 g/d XOS and 15 g/d EXE (XOS + EXE). The 60-d experimental period consisted of a 14-d adaptation period and a 46-d sampling period. The enteric CO2 and CH4 emissions and O2 consumption were measured using two GreenFeed units, which were further used to determine the energy utilization efficiency of cows. RESULTS: Compared with CON, cows fed XOS, EXE or XOS + EXE significantly (P < 0.05) increased milk yield, true protein and fat concentration, and energy-corrected milk yield (ECM)/DM intake, which could be reflected by the significant improvement (P < 0.05) of dietary NDF and ADF digestibility. The results showed that dietary supplementation of XOS, EXE or XOS + EXE significantly (P < 0.05) reduced CH4 emission, CH4/milk yield, and CH4/ECM. Furthermore, cows fed XOS demonstrated highest (P < 0.05) metabolizable energy intake, milk energy output but lowest (P < 0.05) of CH4 energy output and CH4 energy output as a proportion of gross energy intake compared with the remaining treatments. CONCLUSIONS: Dietary supplementary of XOS, EXE or combination of XOS and EXE contributed to the improvement of lactation performance, nutrient digestibility, and energy utilization efficiency, as well as reduction of enteric CH4 emissions of lactating Jersey cows. This promising mitigation method may need further research to validate its long-term effect and mode of action for dairy cows.

Manganese triggers persistent activation of the integrated stress response by inhibition of SIRT1 on deacetylation of GADD34.

Overexposure to manganese (Mn) is conducive to neurodegenerative diseases and neuronal injury. Persistent activation of the integrated stress response (ISR) has a substantial impact on the etiology of neurodegenerative disorders by interfering with intracellular homeostasis. Nevertheless, the precise mechanism through which ISR engages in Mn-related neurotoxicity remains unclear. Sirtuin 1 (SIRT1), a typical NAD+-dependent protein deacetylase, which is known to participate in Mn-induced neuronal damage. Therefore, the aim of our study was to clarify how SIRT1 regulates persistent ISR activation in mouse hippocampal neuronal cells (HT-22 cells) exposed to various concentrations of Mn. We discovered that persistent ISR activation was engaged in Mn-triggered mitochondrial and exogenous apoptotic signaling pathways, which was attributed to the excessive phosphorylation of eukaryotic translation initiation factor 2α (eIF2α). Growth arrest and DNA damage-inducible protein 34 (GADD34) is known to be responsible for down-regulating the phosphorylation of eIF2α. However, Mn promoted GADD34 protein expression and its acetylation level. We further investigated the effect of SIRT1 on the acetylation of GADD34 by overexpressing and silencing SIRT1. We discovered that SIRT1 activation significantly declined the acetylation level of GADD34, thus alleviating persistent ISR activation-mediated neuronal apoptosis in HT-22 cells-treated with Mn. In summary, these results suggested that Mn induced persistent activation of the ISR by inhibition of SIRT1 on deacetylation of GADD34.

Manganese-induced PINK1 S-nitrosylation exacerbates nerve cell damage by promoting ZNF746 repression of mitochondrial biogenesis.

Occupational exposure and non-occupational exposure to excessive levels of manganese (Mn) result in neuronal cell damage through mitochondrial dysfunction. The functional integrity of mitochondria is maintained by mitophagy and mitochondrial biogenesis. Although Mn-induced S-nitrosylation of PTEN-induced putative kinase 1 (PINK1) can interfere with mitophagy, its effect on mitochondrial biogenesis remains unclear. In this study, we established a rat model of Mn poisoning or "manganism" to examine the relationship between PINK1 S-nitrosylation and impairment of mitochondrial biogenesis, and found that treatment with 60 mg/kg Mn induced marked neurobehavioral abnormalities in rats and significantly increased the S-nitrosylation level of PINK1. We also found that the nuclear-encoded peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PPARGC1A)-mediated mitochondrial biogenesis was significantly upregulated in rats treated with 15 and 30 mg/kg Mn, and downregulated in rats treated with 60 mg/kg Mn. We further investigated the role of S-nitrosylated PINK1 and its molecular mechanism in the high-dose Mn-mediated impairment of mitochondrial biogenesis in primary cultured neurons treated with the nitric oxide synthase 2 (NOS2) inhibitor 1400 W. Our results revealed that the PPARGC1A-mediated mitochondrial biogenesis was upregulated in neurons treated with 100 µM, but downregulated in neurons treated with 200 µM Mn, which was similar to the in vivo results. However, treatment with 1400W could effectively prevent the 200 µM Mn-mediated impairment of mitochondrial biogenesis by suppressing nitric oxide (NO)-mediated PINK1 S-nitrosylation and rescuing Parkin-interacting substrate (PARIS, ZNF746) degradation, thereby upregulating mitochondrial biogenesis via PPARGC1A. These findings demonstrated that S-nitrosylation of PINK1 and subsequent prevention of ZNF746 degradation were crucial signaling processes involved in the Mn-mediated impairment of mitochondrial biogenesis, which might serve as an underlying mechanism of Mn-induced neurotoxicity. Furthermore, this study provided a reliable target for the prevention and treatment of manganism.

Melatonin attenuates manganese-induced mitochondrial fragmentation by suppressing the Mst1/JNK signaling pathway in primary mouse neurons.

Manganese (Mn) toxicity is mainly caused by excessive Mn content in drinking water and occupational exposure. Moreover, overexposure to Mn can impair mental, cognitive, memory, and motor capacities. Although melatonin (Mel) can protect against Mn-induced neuronal damage and mitochondrial fragmentation, the underlying mechanism remains elusive. Here, we examined the related molecular mechanisms underlying Mel attenuating Mn-induced mitochondrial fragmentation through the mammalian sterile 20-like kinase-1 (Mst1)/JNK signaling path. To test the role of Mst1 in mitochondrial fragmentation, we treated mouse primary neurons overexpressing Mst1 with Mel and Mn stimulation. In normal neurons, 10 µM Mel reduced the effects of Mn (200 µM) on Mst1 expression at the mRNA and protein levels and on phosphorylation of JNK and Drp1, Drp1 mitochondrial translocation, and mitochondrial fragmentation. Conversely, overexpression of Mst1 hindered the protective effect of Mel (10 µM) against Mn-induced mitochondrial fragmentation. Anisomycin (ANI), an activator of JNK signaling, was similarly found to inhibit the protective effect of Mel on mitochondria, while Mst1 levels were not significantly changed. Thus, our results demonstrated that 10 µM Mel negatively regulated the Mst1-JNK pathway, thereby reducing excessive mitochondrial fission, maintaining the mitochondrial network, and alleviating Mn-induced mitochondrial dysfunction.

Manganese induces S-nitrosylation of PINK1 leading to nerve cell damage by repressing PINK1/Parkin-mediated mitophagy.

Chronic exposure to excess manganese (Mn) causes neurotoxicity, which is characterized by Parkinson-like symptoms and referred to as manganism. In the last few decades, mitochondrial damage and subsequent energy failure have been reported to be important mechanisms of Mn toxicity, yet how Mn causes mitochondrial damage remains largely unknown. Here, we demonstrated that Mn induced S-nitrosation of phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1), a master regulator in the mitophagy pathway, results in dysregulation of mitophagy and nerve cell injury in the rat striatum. We cultured primary neurons and used 1400 W, a potent and selective inducible nitric oxide synthase (iNOS) inhibitor, as an intervention to verify the precise mechanism of Mn-induced dysregulation of mitophagy. We demonstrated that Mn-induced S-nitrosylation of PINK1 decreased the phosphorylated level of parkin RBR E3 ubiquitin-protein ligase (Parkin), as well as the translocation of Parkin to damaged mitochondria, which led to the accumulation of damaged mitochondria and mitochondrial-mediated apoptosis. Our findings indicated the unusual connection between nitrative stress and mitochondrial dysfunction in Mn-induced neurotoxicity. These data highlight the role of S-nitrosation of PINK1 in Mn-induced dysregulation of mitophagy and provide a reliable target for the development of specific drugs and the early treatment of manganism, which has important theoretical and practical significance.

Resveratrol reduces DRP1-mediated mitochondrial dysfunction via the SIRT1-PGC1α signaling pathway in manganese-induced nerve damage in mice.

Excessive manganese (Mn) exposure can cause nerve damage and mitochondrial dysfunction, which may involve defects in mitochondrial dynamics. Resveratrol (RSV) exerts a wide range of beneficial effects via activation of sirtuin 1 (SIRT1) and thus may positively impact Mn-induced mitochondrial damage through the regulation of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α) by SIRT1. In this study, we investigated the molecular mechanisms by which RSV alleviates the nerve injury and mitochondrial fragmentation caused by Mn in C57 BL/6 mice. Our results demonstrated that RSV activated the deacetylase activity of SIRT1 and protected against the surge of mitochondrial reactive oxygen species, the loss of mitochondrial membrane potential, and the attenuation of ATP caused by Mn. RSV, therefore, inhibits mitochondrial fragmentation and safeguards neural cells. Increased deacetylase activity led to a reduction in the acetylation of PGC-1α, which directly regulates DRP1 expression by binding to the DRP1 promoter. The resultant attenuation of DRP1-mediated mitochondrial fragmentation in RSV-pretreated mice was abolished by the addition of the SIRT1 inhibitor EX527. Taken together, these findings indicate that RSV alleviates Mn-induced mitochondrial dysfunction mediated by DRP1 by modulating the SIRT1/PGC-1α signaling pathway.

Resveratrol attenuates manganese-induced oxidative stress and neuroinflammation through SIRT1 signaling in mice.

Exposure to excess levels of manganese (Mn) leads to neurotoxicity. Increasing evidence demonstrates that oxidative stress and neuroinflammation are important pathological causes of neurotoxicity. Resveratrol (Rsv), a sirtuin-1 (SIRT1) activator, plays an important role in neuroprotection. However, the molecular mechanisms of Rsv alleviating Mn-induced oxidative stress and neuroinflammation are not fully understood. To evaluate whether Rsv treatment relieves the oxidative stress and neuroinflammation in the hippocampus after Mn exposure through SIRT1 signaling, C57BL/6 adult mice were exposed to MnCl2 (200 µmol/kg), Rsv (30 mg/kg), and EX527 (5 mg/kg). Our results showed that administering MnCl2 for 6 weeks caused behavioral impairment and nerve cell injury in hippocampal tissue, which was related to oxidative stress and neuroinflammation. Activating Mn-induced JNK and inhibiting SIRT1 increased the phosphorylated and acetylated levels of NF-κB and STAT3, respectively. However, Rsv reduced the phosphorylated and acetylated levels of NF-κB and STAT3, and attenuated Mn-induced oxidative stress and inflammatory cytokines by activating SIRT1 signaling. Most importantly, EX527, a potent SIRT1 inhibitor, inactivated SIRT1, which prevented Rsv from exerting its beneficial effects. Taken together, our findings revealed that Rsv alleviated Mn-induced oxidative stress and neuroinflammation in adult mice by activating SIRT1.

Manganese-induced alpha-synuclein overexpression aggravates mitochondrial damage by repressing PINK1/Parkin-mediated mitophagy.

Chronic manganese (Mn) exposure is related to elevated risks of neurodegenerative diseases, and mitochondrial dysfunction is considered a critical pathophysiological feature of Mn neurotoxicity. Although previous research has demonstrated Mn-induced alpha-synuclein (α-Syn) overexpression, the role of α-Syn in mitochondrial dysfunction remains unclear. Here, we used Wistar rats and human neuroblastoma cells (SH-SY5Y cells) to elucidate the molecular mechanisms underlying how α-Syn overexpression induced by different doses of Mn (15, 30, and 60 mg/kg) results in mitochondrial dysfunction. We found that Mn-induced neural cell injury was associated with mitochondrial damage. Furthermore, Mn upregulated α-Syn protein levels and increased the interaction between α-Syn and mitochondria. We then used a lentivirus vector containing α-Syn shRNA to examine the effect of Mn-induced α-Syn protein on PINK1/Parkin-mediated mitophagy in SH-SY5Y cells. Our data demonstrated that the knockdown of α-Syn decreased the interaction between α-Syn and PINK1. The enhanced level of phosphorylated Parkin (p-Parkin) was due to the decrease of the interaction between α-Syn and PINK1. Moreover, the knockdown of α-Syn increased recruitment of p-Parkin to mitochondria. Collectively, these observations revealed that Mn-induced α-Syn overexpression repressed PINK1/Parkin-mediated mitophagy and exacerbated mitochondrial damage.

Drivers' Attention Strategies before Eyes-off-Road in Different Traffic Scenarios: Adaptation and Anticipation.

The distribution of drivers' visual attention prior to diverting focus from the driving task is critical for safety. The object of this study is to investigate drivers' attention strategy before they occlude their vision for different durations under different driving scenarios. A total of 3 (scenarios) × 3 (durations) within-subjects design was applied. Twenty-three participants completed three durations of occlusion (0, 1, and 2 s) test drive in a motion-based driving simulator under three scenarios (urban, rural, motorway). Drivers' occlusion behaviour, driving behaviour, and visual behaviour in 6 s before occlusion was analyzed and compared. The results showed that drivers tended to slow down and increased their attention on driving task to keep safety in occlusion 2 s condition. The distribution of attention differed among different driving scenarios and occlusion durations. More attention was directed to Forward position and Speedometer in occlusion conditions, and a strong shift in attention from Forward position to Road users and Speedometer was found in occlusion 2 s condition. Road users was glanced more frequently in urban road with a higher percentage of attention transitions from Forward position to Road users. While gaze switching to Speedometer with a higher intensity was found on motorway. It suggests that drivers could adapt their visual attention to driving demand and anticipate the development of upcoming situations by sampling enough driving-related information before eyes-off-road. Moreover, the adaptation and anticipation are in accordance with driving situation and expected eyes-off-road duration. Better knowledge about attentional strategies before attention away from road contributes to more efficient and safe interaction with additional tasks.

Attentional Demand as a Function of Contextual Factors in Different Traffic Scenarios.

OBJECTIVE: To assess the attentional demand of different contextual factors in driving. BACKGROUND: The attentional demand on the driver varies with the situation. One approach for estimating the attentional demand, via spare capacity, is to use visual occlusion. METHOD: Using a 3 × 5 within-subjects design, 33 participants drove in a fixed-base simulator in three scenarios (i.e., urban, rural, and motorway), combined with five fixed occlusion durations (1.0, 1.4, 1.8, 2.2, and 2.6 s). By pressing a microswitch on a finger, the driver initiated each occlusion, which lasted for the same predetermined duration within each trial. Drivers were instructed to occlude their vision as often as possible while still driving safely. RESULTS: Stepwise logistic regression per scenario indicated that the occlusion predictors varied with scenario. In the urban environment, infrastructure-related variables had the biggest influence, whereas the distance to oncoming traffic played a major role on the rural road. On the motorway, occlusion duration and time since the last occlusion were the main determinants. CONCLUSION: Spare capacity is dependent on the scenario, selected speed, and individual factors. This is important for developing workload managers, infrastructural design, and aspects related to transfer of control in automated driving. APPLICATION: Better knowledge of the determinants of spare capacity in the road environment can help improve workload managers, thereby contributing to more efficient and safer interaction with additional tasks.