Study on chest injury and bulletproof vest protection under the combined action of blast wave and fragments.

Using a simulation based method, this paper analysis the damage effect of blast wave and fragments on human body and the protective effect of bulletproof vest. The results show that compared with the single blast shock wave, the chest injury is more serious under the combined action of blast shock wave and fragments. The peak stress of sternum, costal cartilage and rib increases by 334.34%, 170.23% and 39.72%, respectively. The peak stress on the side of the lung decreases by 3.95%, with little change. The peak stress on the front and back of the lung increases by 83.58% and 409.09% respectively. Overall, the lung injury is aggravated. With the addition of the bulletproof vest, the damage caused by fragments is reduced, and the peak stress of the sternum and the costal cartilage decreases by 48.77% and 69.78%, respectively. Due to the interaction of the blast wave with the vest and the chest, the damage caused by blast wave is aggravated. The peak stress of rib increases by 13.55%, and the peak stress of lung front, side and back increases by 1.22%, 6.51% and 3.57%, respectively.

A diagnostic prediction model for hypertension in Han and Yugur population from the China National Health Survey (CNHS).

BACKGROUND: The prevalence of hypertension is high among Chinese adults, thus, identifying non-hypertensive individuals at high risk for intervention will help to improve the efficiency of primary prevention strategies. METHODS: The cross-sectional data on 9699 participants aged 20 to 80 years were collected from the China National Health Survey in Gansu and Hebei provinces in 2016 to 2017, and they were nonrandomly split into the training set and validation set based on location. Multivariable logistic regression analysis was performed to develop the diagnostic prediction model, which was presented as a nomogram and a website with risk classification. Predictive performances of the model were evaluated using discrimination and calibration, and were further compared with a previously published model. Decision curve analysis was used to calculate the standardized net benefit for assessing the clinical usefulness of the model. RESULTS: The Lasso regression analysis identified the significant predictors of hypertension in the training set, and a diagnostic model was developed using logistic regression. A nomogram with risk classification was constructed to visualize the model, and a website ( https://chris-yu.shinyapps.io/hypertension_risk_prediction/ ) was developed to calculate the exact probabilities of hypertension. The model showed good discrimination and calibration, with the C-index of 0.789 (95% confidence interval [CI]: 0.768, 0.810) through internal validation and 0.829 (95% CI: 0.816, 0.842) through external validation. Decision curve analysis demonstrated that the model was clinically useful. The model had a higher area under receiver operating characteristic curves in training and validation sets compared with a previously published diagnostic model based on Northern China population. CONCLUSION: This study developed and validated a diagnostic model for hypertension prediction in Gansu Province. A nomogram and a website were developed to make the model conveniently used to facilitate the individualized prediction of hypertension in the general population of Han and Yugur.

Experimental and numerical analysis of biomechanical effects in cervical spine positioning rotation manipulation.

Unlocking the biomechanical effects of cervical spine positioning rotation manipulation in the treatment of patients with neck pain. In this paper, the safety of the cervical positioning rotation manipulation is analyzed by experimentally obtaining head kinematic data, importing them into a finite element model that has been developed and validated, and calculating and analyzing the angular displacements, disc pressures, and articular surface contact forces in the normal and pathological models. The results show that the cervical spine positioning rotation technique is more effective in adjusting the position and applying force to the cervical spine C5-C6 "tendon out of the groove and bone misalignment" pathological model. Also, the cervical positioning rotation manipulation is applied with less variation in disc nucleus pulposus pressure than in the non-positioning situation. Thus, in patients with disc degeneration, cervical positioning rotational manipulation has a more direct mechanical effect and is safer than non-positioning rotational manipulation. The cervical spine positioning rotation manipulation is a safe method that can effectively treat patients with neck pain. It has been well demonstrated in the computational analysis of the pathological model.

Study on protective performance and gradient optimization of helmet foam liner under bullet impact.

Protective equipment in war plays a vital role in the safety of soldiers, the threat to soldiers from brain damage caused by deformation at the back of the helmet cannot be ignored, so research on reduce blunt post-cranial injury has great significance and value. This study first conducted gunshot experiments, used rifle bullets impact bulletproof plate and different density liner foam to record the incident process and internal response of craniocerebral model. After verifying the accuracy of finite element model through experimental data, optimization model is established based on response surface method to optimize the structure of gradient foam, analyze the cranial strain and energy absorption to select the best density and thickness distribution of each foam layer. Optimization results show that liner foam which designed to have lower density and thicker thickness for impact and brace layers, higher density and thinner thickness for middle layer can significantly improve the energy absorption efficiency. Compared to the 40.65 J of energy absorption before optimization, the optimized gradient foam can absorb 109.3 J of energy, with a 169% increase in the absorption ratio. The skull strain in the craniocerebral model was reduced from 1.260 × 10-2 to 1.034 × 10-2, with a reduction of about 22%. This study provides references for the design and development of protective equipment and plays an important role in ensuring the safety of soldiers in the battlefield environment.

Involvement of Mitophagy in Primary Cultured Rat Neurons Treated with Nanoalumina.

The aim of this study was to explore the influence of the neurotoxicity of nanoalumina on primarily cultured neurons. Normal control, particle size control, aluminum, micron-alumina, and nanoalumina at 50-nm and 13-nm particle sizes were included as subjects to evaluate the level of apoptosis, necrosis, and autophagy in primarily cultured neurons and further explore the mitophagy induced by nanoalumina. The results demonstrated that nanoalumina could induce neuronal cell apoptosis, necrosis, and autophagy, among which autophagy was the most notable. When the autophagy inhibitor was added to the nanoalumina-treated group, it significantly downregulated the protein expression levels of Beclin-1 and LC3II/LC3. Observation under a transmission electron microscope and a fluorescence microscope revealed mitophagy characteristics induced by nanoalumina. Additionally, the neurotoxicological effects induced by nanoalumina were more significant than those induced by aluminum and in a particle size-dependent manner.

Experimental Study on Intracranial Pressure and Biomechanical Response in Rats under the Blast Wave.

Explosion overpressure propagates extracranially and causes craniocerebral injury after being transmitted into the brain. Studies on the extent of skull to reduce impact overpressure are still lacking. Therefore, it is necessary to study the relationship between intracranial pressure (ICP) and external field pressure and the situation of craniocerebral injury under the blast wave. Pressure sensor of ϕ 1.2 mm was disposed 3 mm posterior to the bregma of rat skull, and type I biological shock tube (BST-I) was used as the source of injury while a side-on air pressure sensor was installed at the horizontal position of the ICP sensor. Eleven groups of blast experiments with peak air overpressure ranging from 167 kPa to 482 kPa were performed to obtain the variation law of ICP and injury of rats. Data measured by sensors show that the peak pressure formed in the rat brain are lower than the external air overpressure; the differential pressure between the inside and outside of the brain is 27-231 kPa. When side-on air overpressure is ≤363 kPa, ICP is ≤132 kPa, and the hemorrhage area of the rat's brain is <15%, the injury is minor. When side-on air overpressure is 363 kPa-401 kPa, ICP range is from 132 kPa to 248 kPa, hemorrhage area is about 15%-20%, and the injury increases. When side-on air overpressure is 401 kPa-435 kPa, ICP range from 248 kPa to 348 kPa, the hemorrhage area is about 20%-24%, and the injury is serious. When side-on air overpressure ≥482 kPa, the peak ICP surged to 455 kPa and the peak negative ICP reached -84 kPa, the hemorrhage area exceeded 26%. When the external blast wave is weak, skull can absorb the blast wave better, reducing the pressure by 81.4%, when the external shockwave is strong, skull only reduces the pressure by 5.6%, but both can play certain protective role. The fitting curve of air overpressure and ICP can be used to predict the changes of ICP under different external blast overpressure. Analysis of cranial injury showed that the area of cranial hemorrhage with extremely severe injury increased by 107.9% compared with mild injury, increased by 53.3% compared with moderate injury, and increased by 21.6% compared with severe injury. This work may provide references for the dynamic response of biological cranial and brain injury mechanism under the effect of blast wave.

Comprehensive analysis of competitive endogenous RNAs network: Identification and validation of prediction model composed of mRNA signature and miRNA signature in gastric cancer.

Gastric cancer (GC), one of the most lethal malignant tumors, is highly aggressive with a poor prognosis, while the molecular mechanisms underlying it remain largely unknown. Although advanced imaging techniques and comprehensive treatment facilitate the diagnosis and survival of some GC patients, the precise diagnosis and prognosis are still a challenge. The present study used publicly available gene expression profiles from The Cancer Genome Atlas and Gene Expression Omnibus datasets including mRNA, micro (mi)RNA and circular (circ)RNA of GC to establish a competing endogenous RNA network (ceRNA). Further, the present study performed least absolute shrinkage and selector operator regression analysis on the hub RNAs to establish a prediction model with mRNA and miRNA. The ceRNA network contained 109 edges and 56 nodes and the visible network contains 13 miRNAs, 9 circRNAs and 34 mRNAs. The five mRNA-based signature were CTF1, FKBP5, RNF128, GSTM2 and ADAMTS1. The area under curve (AUC) value of the diagnosis training cohort was 0.9975. The prognosis of the high-risk group (RiskScore >4.664) was worse compared with that of the low-risk group (RiskScore ≤4.664; P<0.05) in the training cohort. The five miRNA-based signature were miR-145-5p, miR-615-3p, miR-6507-5p, miR-937-3p and miR-99a-3p. The AUC value of the diagnosis training cohort was 0.9975. The prognosis of the high-risk group (RiskScore >1.621) was worse compared with that of the low-risk group (RiskScore ≤1.621; P<0.05) in the training cohort. The validation cohorts indicated that both five mRNA and five miRNA-based signatures had strong predictive power in diagnosis and prognosis for GC. In conclusion, a ceRNA network was established for GC and a five mRNA-based signature and a five miRNA-based signature was identified that enabled diagnosis and prognosis of GC by assigning patient to a high-risk group or low-risk group.

Association between Serum Uric Acid and Hypertension in Han and Yugur of Gansu Province: The China National Health Survey.

INTRODUCTION: Serum uric acid (SUA) has been found correlated with an increased risk of hypertension, but evidence is sparse regarding the association in Gansu Province, especially in Yugur people. This study aimed to explore the nonlinear relationship between SUA levels and hypertension in Han and Yugur people in China. METHODS: The cross-sectional study samples (n = 5,327) were from the China National Health Survey (CNHS) in Gansu Province. Participants were selected using a multistage stratified cluster sampling method. SUA was measured by enzymatic methods. The restricted cubic spline regression was performed to evaluate the shape of the association. RESULTS: The overall prevalence of hypertension and hyperuricemia was 28.4% and 17.0%, respectively, in this study. Comparing the highest (>416.4 µmol/L) to the lowest (<254.1 µmol/L) SUA level groups, the multivariable adjusted differences and 95% confidence intervals (CIs) in blood pressure (BP) were 6.15 (4.22, 8.08) mm Hg and 4.87 (3.51, 6.23) mm Hg for SBP and DBP in Han, and 2.22 (-0.73, 5.18) mm Hg and 2.56 (0.38, 4.75) mm Hg for SBP and DBP in Yugur people, respectively. The corresponding odds ratios (95% CIs) for hypertension were 3.16 (2.26, 4.43) and 2.37 (1.46, 3.89) in Han and Yugur people, respectively. The restricted cubic spline regression models illustrated that both BP level and the risk of hypertension increased with elevated SUA levels in Han and Yugur people. CONCLUSIONS: SUA was significantly and independently associated with an increased risk of hypertension in Han and Yugur people. Prospective studies are needed to confirm these findings.

Accuracy and comparison of two rapid multiplex PCR tests for gastroenteritis pathogens: a systematic review and meta-analysis.

OBJECTIVES: The primary aim is to provide a summary of evidence for the diagnostic accuracies of multiplex PCR gastrointestinal (GI) panels-BioFire FilmArray and Luminex xTAG on the detection of gastroenteritis pathogens. The secondary aim is to compare the performance of these GI panels head to head. METHODS: A comprehensive search up to 1 December 2019 was conducted on PubMed, Embase, Ovid Medline and Web of Science for studies that used FilmArray or Luminex xTAG Gastrointestinal Pathogen Panel (GPP) for diagnosis of acute gastroenteritis. A summary of diagnostic accuracies for the 16 pathogens were calculated by comparing the GI panels to the current gold standards (conventional standard microbiology techniques such as culture or PCR for bacteria, PCR or enzyme immunoassay (EIA) for viruses, microscopy or EIA for parasite). Hierarchical summary receiver operating characteristic (HSROC) curve analysis, pretest and post-test probabilities were used for estimating the pathogen detection performance. RESULTS: A total of 11 studies with 7085 stool samples were eligible for analysis. Multiplex PCRs demonstrated high diagnostic accuracy, with specificity ≧0.98 and area under the ROC curve (AUROC) ≧0.97 for all the pathogens except for Yersinia enterocolitica (AUROC 0.91). The FilmArray panel demonstrated a higher sensitivity than xTAG GPP for most of the pathogens with the exception of Rotavirus A (xTAG GPP and FilmArray were both 0.93). CONCLUSIONS: This is the first meta-analysis that is a head-to-head comparison examining the performance of the novel multiplex PCR-based tests Luminex xTAG GPP and FilmArray GI panel in detecting each pathogen. Point estimates calculated from eligible studies showed that both GI panels are highly accurate and may provide important diagnostic information for early identification of gastroenteritis. In addition, although FilmArray has higher sensitivity and post-test probability than xTAG GPP for most of the pathogens, how this will translate to a clinical setting remains unclear.

Involvement of Mitophagy in Aluminum Oxide Nanoparticle-Induced Impairment of Learning and Memory in Mice.

Aluminum oxide nanoparticles (nano-aluminum) have been known to be widespread in the environment for decades. Exposure to nano-aluminum may impair learning and memory, but the potential mechanism has not yet been elucidated. In neurons, efficient clearance of damaged mitochondria through mitophagy plays an important role in mitochondrial energy supply, neuronal survival, and health. However, abnormal mitophagy induces accumulation of damaged mitochondria, which induces cellular dysfunction, contributing to the impairment of learning and memory. It is currently unclear whether nano-aluminum interferes with the function of nerve cells through mitophagy, leading to learning and memory disorders. Institute of Cancer Research (ICR) female mice were randomly divided into four groups, and treated with normal saline (control) and 50 nm nano-aluminum at concentrations of 25, 50, and 75 mg/kg for 30 days. Our results showed that exposure to nano-aluminum impaired the spatial learning and memory of mice. Superoxide dismutase levels decreased, whereas the levels of malondialdehyde increased. Moreover, there were significant pathological changes in the ultra-structure and function of mitochondria. Finally, expression of autophagy-related proteins LC3-II and Beclin-1 was upregulated and p62 expression decreased, but the expression of apoptotic and necrosis-related proteins had no significant difference among groups. Our results suggest that learning and memory impairment induced by nano-aluminum could be related to mitophagy.

The positive effect of selective prostaglandin E2 receptor EP2 and EP4 blockade on cystogenesis in vitro is counteracted by increased kidney inflammation in vivo.

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a major cause of end-stage kidney disease in man. The central role of cyclic adenosine monophosphate (cAMP) in ADPKD pathogenesis has been confirmed by numerous studies including positive clinical trial data. Here, we investigated the potential role of another major regulator of renal cAMP, prostaglandin E2 (PGE2), in modifying disease progression in ADPKD models using selective receptor modulators to all four PGE2 receptor subtypes (EP1-4). In 3D-culture model systems utilizing dog (MDCK) and patient-derived (UCL93, OX161-C1) kidney cell lines, PGE2 strikingly promoted cystogenesis and inhibited tubulogenesis by stimulating proliferation while reducing apoptosis. The effect of PGE2 on tubulogenesis and cystogenesis in 3D-culture was mimicked or abolished by selective EP2 and EP4 agonists or antagonists but not those specific to EP1 or EP3. In a Pkd1 mouse model (Pkd1nl/nl), kidney PGE2 and COX-2 expression were increased by two-fold at the peak of disease (week four). However, Pkd1nl/nl mice treated with selective EP2 (PF-04418948) or EP4 (ONO-AE3-208) antagonists from birth for three weeks had more severe cystic disease and fibrosis associated with increased cell proliferation and macrophage infiltration. A similar effect was observed for the EP4 antagonist ONO-AE3-208 in a second Pkd1 model (Pax8rtTA-TetO-Cre-Pkd1f/f). Thus, despite the positive effects of slowing cyst growth in vitro, the more complex effects of inhibiting EP2 or EP4 in vivo resulted in a worse outcome, possibly related to unexpected pro-inflammatory effects.

Global microRNA profiling in human urinary exosomes reveals novel disease biomarkers and cellular pathways for autosomal dominant polycystic kidney disease.

MicroRNAs (miRNAs) play an important role in regulating gene expression in health and disease but their role in modifying disease expression in Autosomal Dominant Polycystic Kidney Disease (ADPKD) remains uncertain. Here, we profiled human urinary exosome miRNA by global small RNA-sequencing in an initial discovery cohort of seven patients with ADPKD with early disease (eGFR over 60ml/min/1.73m2), nine with late disease (eGFR under 60ml/min/1.73m2), and compared their differential expression with six age and sex matched healthy controls. Two kidney-enriched candidate miRNA families were identified (miR-192/miR-194-2 and miR-30) and selected for confirmatory testing in a 60 patient validation cohort by quantitative polymerase chain reaction. We confirmed that miR-192-5p, miR-194-5p, miR-30a-5p, miR-30d-5p and miR-30e-5p were significantly downregulated in patient urine exosomes, in murine Pkd1 cystic kidneys and in human PKD1 cystic kidney tissue. All five miRNAs showed significant correlations with baseline eGFR and ultrasound-determined mean kidney length and improved the diagnostic performance (area under the curve) of mean kidney length for the rate of disease progression. Finally, inverse correlations of these two miRNA families with increased expression in their predicted target genes in patient PKD1 cystic tissue identified dysregulated pathways and transcriptional networks including novel interactions between miR-194-5p and two potentially relevant candidate genes, PIK3R1 and ANO1. Thus, our results identify a subset of urinary exosomal miRNAs that could serve as novel biomarkers of disease progression and suggest new therapeutic targets in ADPKD.

Oxidative and nitrosative stress in the neurotoxicity of polybrominated diphenyl ether-153: possible mechanism and potential targeted intervention.

Polybrominated diphenyl ethers (PBDEs) have been known to exhibit neurotoxicity in rats; however, the underlying mechanism remains unknown and there is no available intervention. In this study, we aimed to investigate the role of oxidative and nitrosative stress in the neurotoxicity in the cerebral cortex and primary neurons in rats following the BDE-153 treatment. Compared to the untreated group, BDE-153 treatment significantly induced the neurotoxic effects in rats, as manifested by the increased lactate dehydrogenase (LDH) activities and cell apoptosis rates, and the decreased neurotrophic factor contents and cholinergic enzyme activities in rats' cerebral cortices and primary neurons. When compared to the untreated group, the oxidative and nitrosative stress had occurred in the cerebral cortex or primary neurons in rats following the BDE-153 treatment, as manifested by the increments in levels of reactive oxygenspecies (ROS), malondialdehyde (MDA), nitric oxide (NO), and neuronal nitric oxide synthase (nNOS) mRNA and protein expressions, along with the decline in levels of superoxide dismutase (SOD) activity, glutathione (GSH) content, and peroxiredoxin I (Prx I) and Prx II mRNA and protein expressions. In addition, the ROS scavenger N-acetyl-l-cysteine (NAC) or NO scavenger NG-Nitro-l-arginine (L-NNA) significantly rescued the LDH leakage and cell survival, reversed the neurotrophin contents and cholinergic enzymes, mainly via regaining balance between oxidation/nitrosation and antioxidation. Overall, our findings suggested that oxidative and nitrosative stresses are involved in the neurotoxicity induced by BDE-153, and that the antioxidation is a potential targeted intervention.

The Additive Interaction between Body Mass Index and Hypertension Family History in Han and Yugur: The China National Health Survey (CNHS).

OBJECTIVE: To estimate the additive interaction of body mass index (BMI) and family history of hypertension (FHH) on hypertension and explore whether the interaction could be influenced by behavioural risk factors. METHODS: The cross-sectional data on 5791 participants were from the China National Health Survey in Gansu province in 2016. We assessed the additive interaction by calculating the relative excess risk due to interaction (RERI), the attributable proportion due to interaction (AP), and the synergy index (SI). RESULTS: ORs for hypertension were highest in Han (13.52, 95% CI: 9.45 to 19.34) and Yugur (13.85, 95% CI: 8.48 to 22.63) with the combination of obesity and FHH. The interaction of BMI and FHH was significant in Han people, with the RERI, AP, and SI and their 95% CIs being 2.48 (1.13 to 3.82), 0.33 (0.19 to 0.47), and 1.61 (1.26 to 2.07) for overweight and FHH and 6.32 (1.91 to 10.73), 0.47 (0.27 to 0.67), and 2.02 (1.33 to 3.07) for obesity and FHH, respectively. The interaction of BMI and FHH was not significant in Yugur people. Adjustment for behavioural risk factors had little influence on the interactions, and risks of hypertension remained increased. CONCLUSIONS: BMI and FHH were associated with hypertension, and the interaction of BMI and FHH on hypertension was significant in Han but not in Yugur people. Behavioural risk factors had little influence on the associations and interactions. The exacerbation of hypertension risks by overweight or obesity in hypertension families deserves attention in weight control and community care.

Total polysaccharides of adlay bran (Coix lachryma-jobi L.) improve TNF-α induced epithelial barrier dysfunction in Caco-2 cells via inhibition of the inflammatory response.

Dysfunction of the intestinal epithelial barrier plays an important role in the pathogenesis of several intestinal diseases, including celiac disease, inflammatory bowel disease, and irritable bowel syndrome. The present research was carried out to investigate the protective effect of total polysaccharides of adlay bran (TPA) on TNF-α-evoked epithelial barrier dysfunction in Caco-2 cells. Caco-2 cells were treated with or without TPA in the absence or presence of TNF-α, and transepithelial electrical resistance (TEER) and Phenol Red flux were assayed to evaluate the intestinal epithelial barrier function. The results indicated that TPA suppressed the TNF-α-induced release of pro-inflammatory factors. Furthermore, TPA obviously assuaged both the increased paracellular permeability and the decrease of TEER in TNF-α-challenged Caco-2 cells. Furthermore, TPA obviously assuaged TNF-α-evoked up-regulation of IL-8 and IL-6 expression, down-regulation of occludin and ZO-3 expression, and markedly suppressed the activation and protein expression of NF-κB p65. Our results indicated that TPA assuages the TNF-α-evoked dysfunction of the intestinal epithelial barrier by inhibiting the NF-κB p65-mediated inflammatory response.

Prognostic and clinicopathological significance of Gamma-Glutamyltransferase in patients with hepatocellular carcinoma: A PRISMA-compliant meta-analysis.

BACKGROUND: Many studies explored the prognostic and clinicopathological significance of pretreatment serum Gamma-Glutamyltransferase (GGT) level in hepatocellular carcinoma (HCC). However, there are inconsistent results in the prognostic and clinicopathological significance of pretreatment serum GGT level in HCC. Thus, we conducted this meta-analysis to comprehensively assess the prognostic and clinicopathological significance of pretreatment serum GGT level in HCC patients. METHODS: We systematically searched PubMed, EMBASE and Web of Science for relevant studies (up to June 14, 2018). The estimated hazard ratios (HRs) were used to assess the association between pretreatment serum GGT level and survival in HCC patients. The estimated odds ratios (ORs) were applied to evaluate the correlation between pretreatment serum GGT and clinicopathological features in HCC. RESULTS: Our results showed that high pretreatment serum GGT level was significantly correlated with poor overall survival (OS) (HR = 1.70, 95% CI: 1.54-1.87; P < .01) and disease-free survival/relapse-free survival (DFS/RFS) (HR = 1.56, 95% CI: 1.42-1.71; P < .01). Additionally, our results also revealed that there was a close correlation between GGT level and several clinicopathological features in HCC patients, including vascular invasion, tumor size, tumor number and Alpha-fetoprotein (AFP) level. CONCLUSIONS: This meta-analysis shows that high pretreatment serum GGT level is significantly correlated with poor survival and unfavorable clinicopathological features in HCC patients, suggesting that pretreatment serum GGT may be an economical and effective prognostic biomarker for HCC patients. However, more high-quality studies are still warranted to further validate our findings, considering there are several limitations in this meta-analysis.

Endoplasmic reticulum rather than mitochondria plays a major role in the neuronal apoptosis induced by polybrominated diphenyl ether-153.

Polybrominated diphenyl ether-153 (BDE-153) has been demonstrated to induce neuronal apoptosis in rat cerebral cortex and primary neurons, however, the roles of mitochondria and endoplasmic reticulum (ER) remain unclear in the BDE-153-induced neuronal apoptosis. To this purpose, we observed the mitochondria and ER ultrastructure changes in the neuronal apoptosis in rats following BDE-153 treatment, detected the mitochondrial membrane potential (MMP), Ca2+-Mg2+-ATP enzyme activity, and the changes of mitochondria and ER apoptosis related molecules in rat cerebral cortex and in primary neurons following BDE-153 treatment. Results showed that compared to the control group, neuronal apoptosis was significantly increased in a dose-dependent manner in rat cerebral cortex and in primary neurons following BDE-153 treatment. In comparison with control, BDE-153 treatment induced remarkable ultrastructural changes in ER rather than in mitochondria, and the severity of ER damage was worse with the increasing BDE-153 dose. Meanwhile, ER apoptosis related molecules including caspase-12 (at mRNA level), cleaved caspase-12 (at protein level), and Tmem132a (at mRNA and protein levels) were significantly increased in the cerebral cortex in rats following BDE-153 treatment, while procaspase-12 protein was significantly decreased, comparing with control. In contrast, mitochondria apoptosis related molecules (MMP, Ca2+-Mg2+-ATP enzyme activity, cyt-C protein, caspase-3, 8, 9 mRNA, caspase-8, 9 enzyme activities) did not significantly changed in the cerebral cortex of rats or in primary neurons following BDE-153 treatment, except for the elevated caspase-3 mRNA and enzyme activity. Therefore, we conclude that BDE-153 induced neuronal apoptosis was dependent on p53, and mediated more by ER than mitochondria in the cerebral cortex of rats and in primary neurons. The findings suggest that ER is a potential sensitive target of BDE-153 neurotoxicity, providing a scientific evidence for the mechanism and intervention study on PBDE's neurotoxicity.

Calpain-2/p35-p25/Cdk5 pathway is involved in the neuronal apoptosis induced by polybrominated diphenyl ether-153.

Polybrominated diphenyl ethers (PBDEs) have been demonstrated to induce neurotoxicity in experimental rats and mice, with neuronal apoptosis as one of the major mechanisms, however, the mechanisms underlying PBDEs-induced neuronal apoptosis remain unclear. In this study, we aimed to investigate the role of calpain/p35-p25/Cdk5 pathway in BDE-153-induced neuronal apoptosis in the hippocampus and primary neurons in rats. Results showed that compared to the controls, neuronal apoptosis was significantly increased in vivo and ex vivo, as manifested by the increased hippocampus TUNEL-positive cell rates, apoptotic neurons in Hoechst and AO/EB staining, and the increased LDH activity and percentage of Annexin V-positive cells in rat hippocampus and primary neurons. Calpain activity was significantly increased in all the BDE-153-treated groups in vivo and ex vivo when compared to non-treatment controls. In addition, we showed that calpain-2 accounted for the calpain activation instead of calpain-1, as demonstrated by the up-regulated mRNA and protein expressions in calpain-2 but not calpain-1. Activated calpain truncated p35 into p25, which resulted in the p25/Cdk5 formation and activation. Calpain inhibitor PD150606 or p25/Cdk5 inhibitor Roscovitine relieved neuronal apoptosis mainly via inhibiting the p25/Cdk5 activation. Overall, the findings suggested that calpain-2/p35-p25/Cdk5 pathway was involved in BDE-153-induced neuronal apoptosis, which provides novel insight into the mechanisms of PBDE neurotoxicity.

[Effects of polybrominated diphenyl ether-153 lactation exposure on the concentrations of intracellular calcium ion and calcium-activated related enzymes levels of adult rats' cerebral cortex].

OBJECTIVE: To investigate the effects of polybrominated diphenyl ether-153 (BDE-153) exposure during lactation period on the calcium ion (Ca(2+)) concentration and calcium-activated enzyme levels in cerebral cortical cells among adult rats and to provide a scientific basis for the study on the developmental neurotoxicity of BDE-153. METHODS: Forty newborn male rats were randomly and equally divided into four groups according to their body weights and litters: 1, 5, and 10 mg/kg BDE-153 groups and olive oil solvent control group. On postnatal day 10 (PND 10), the BDE-153 groups were administrated BDE-153 (0.1 ml/10 g body weight) by intraperitoneal injection, while the olive oil solvent control group was given an equal volume of olive oil. Two months later, these rats were decapitated, and the cerebral cortex was separated quickly on an ice-cold dish. The Ca(2+) concentration in cerebral cortical cells was measured by flow cytometry. The activities of calcineurin (CaN) and Ca(2+)-Mg(2+)-ATP enzyme were determined by colorimetric method. The mRNA and protein expression of calpain-1 and calpain-2 was measured by real-time quantitative PCR and Western blot. RESULTS: The mean fluorescence intensities of intracellular Ca(2+) in control group and 1, 5, and 10 mg/kg BDE-153 groups were 10.83, 1.48, 1.93, and 0.62, respectively; the 1, 5, and 10 mg/kg BDE-153 groups had significantly lower intercellular Ca(2+) concentrations than the control group (P < 0.05). The activities of CaN and Ca(2+)-Mg(2+)-ATP enzyme and mRNA and protein expression of calpain-1 showed no significant differences between the 1, 5, and 10 mg/kg BDE-153 groups and control group (P > 0.05). The protein expression of calpain-2 increased as the dose of BDE-153 rose. Compared with the control group (mRNA: 0.81±0.26; protein: 0.15±0.07), the 5 and 10 mg/kg BDE-153 groups had significantly higher mRNA expression of calpain-2 (5 mg/kg BDE-153 group: 1.16±0.52; 10 mg/kg BDE-153 group: 1.32±0.23) and significantly higher protein expression of calpain-2 (5 mg/kg BDE-153 group: 0.31±0.07; 10 mg/kg BDE-153 group: 0.37±0.06) (P < 0.05). The 10 mg/kg BDE-153 group had significantly higher protein expression of calpain-2 than the 1 mg/kg BDE-153 group (0.37±0.06 vs 0.22±0.07, P < 0.05). CONCLUSION: Ca(2+-) mediated calpain-2 activation may be one of the main mechanisms of BDE-153 neurotoxicity.

CDR-restricted engineering of native human scFvs creates highly stable and soluble bifunctional antibodies for subcutaneous delivery.

While myriad molecular formats for bispecific antibodies have been examined to date, the simplest structures are often based on the scFv. Issues with stability and manufacturability in scFv-based bispecific molecules, however, have been a significant hindrance to their development, particularly for high-concentration, stable formulations that allow subcutaneous delivery. Our aim was to generate a tetravalent bispecific molecule targeting two inflammatory mediators for synergistic immune modulation. We focused on an scFv-Fc-scFv format, with a flexible (A4T)3 linker coupling an additional scFv to the C-terminus of an scFv-Fc. While one of the lead scFvs isolated directly from a naïve library was well-behaved and sufficiently potent, the parental anti-CXCL13 scFv 3B4 required optimization for affinity, stability, and cynomolgus ortholog cross-reactivity. To achieve this, we eschewed framework-based stabilizing mutations in favor of complementarity-determining region (CDR) mutagenesis and re-selection for simultaneous improvements in both affinity and thermal stability. Phage-displayed 3B4 CDR-mutant libraries were used in an aggressive "hammer-hug" selection strategy that incorporated thermal challenge, functional, and biophysical screening. This approach identified leads with improved stability and>18-fold, and 4,100-fold higher affinity for both human and cynomolgus CXCL13, respectively. Improvements were exclusively mediated through only 4 mutations in VL-CDR3. Lead scFvs were reformatted into scFv-Fc-scFvs and their biophysical properties ranked. Our final candidate could be formulated in a standard biopharmaceutical platform buffer at 100 mg/ml with<2% high molecular weight species present after 7 weeks at 4 °C and viscosity<15 cP. This workflow has facilitated the identification of a truly manufacturable scFv-based bispecific therapeutic suitable for subcutaneous administration.