Intracellular Nitroreductase-Triggered "On" and "Enhanced" Photoacoustic Signals for Sensitive Imaging of Tumor Hypoxia.

Current molecular photoacoustic (PA) probes are designed with either stimulus-turned "on" or assembly-enhanced signals to trace biological analytes/events. PA probes based on the nature-derived click reaction between 2-cyano-6-aminobenzothiazole (CBT) and cysteine (Cys) (i.e., CBT-Cys click reaction) possess both "turn-on" and "enhanced" PA signals; and thus, should have higher sensitivity. Nevertheless, such PA probes, particularly those for sensitive imaging of tumor hypoxia, remain scarce. Herein, a PA probe NI-Cys(StBu)-Dap(IR780)-CBT (NI-C-CBT) is rationally designed, which after being internalized by hypoxic tumor cells, is cleaved by nitroreductase under the reduction condition to yield cyclic dimer C-CBT-Dimer to turn the PA signal "ON" and subsequently assembled into nanoparticles C-CBT-NPs with additionally enhanced PA signal ("Enhanced"). NI-C-CBT exhibits 1.7-fold "ON" and 3.2-fold overall "Enhanced" PA signals in vitro. Moreover, it provides 1.9-fold and 2.8-fold overall enhanced PA signals for tumor hypoxia imaging in HeLa cells and HeLa tumor-bearing mice, respectively. This strategy is expected to be widely applied to design more "smart" PA probes for sensitive imaging of important biological events in vivo in near future.

Enhanced Photoacoustic Imaging of Urokinase-Type Plasminogen Activator Activity in Tumors.

Photoacoustic (PA) imaging of urokinase-type plasminogen activator (uPA) activity in vivo holds high promise for early diagnosis of breast cancer. Molecular probes with resisted fluorescence (FL) emission for enhanced PA signals of uPA activity have not been reported. Herein, we proposed a molecular probe Cbz-Gly-Gly-Arg-Phe-Phe-IR775 (Z-GGRFF-IR775) which, upon uPA cleavage, assembled into nanoparticles FF-IR775-NP with quenched fluorescence but enhanced PA signals. Experimental results validated that, upon uPA activation, Z-GGRFF-IR775 exhibited 4.7-fold, 4.1-fold, and 2.9-fold higher PA signals over those in uPA inhibitor-treated control groups in vitro, in MDA-MB-231 cells, and in a tumor-bearing mouse model, respectively. We anticipate that this probe could be applied for highly sensitive PA imaging of uPA activity in early stage malignant tumors in the near future.

Caspase-3-Triggered Intracellular Gadolinium Nanoparticle Formation for T1-Weighted Magnetic Resonance Imaging of Apoptosis In Vivo.

Apoptosis, with a hallmark of upregulated protease Caspase-3, has been frequently imaged with various probes to reveal the therapeutic efficiencies of different drugs. However, activatable molecular probes with programmable self-assembling behaviors that enable enhanced T1-weighted magnetic resonance imaging (MRI) of apoptosis remain scarce. Herein, taking advantage of a CBT-Cys click reaction, we rationally designed a Caspase-3-activatable self-assembling probe Ac-Asp-Glu-Val-Asp-Cys(StBu)-Lys(DOTA(Gd))-CBT (DEVDCS-Gd-CBT) for apoptosis imaging in vivo. After Caspase-3 cleavage in apoptotic cells, DEVDCS-Gd-CBT underwent CBT-Cys click reaction to form a cyclic dimer, which self-assembled into Gd nanoparticles. With this probe, enhanced T1-weighted MR images of apoptosis were achieved at low magnetic fields in vitro, in cis-dichlorodiamineplatinum-induced apoptotic cells and in tail-amputation-simulated apoptotic zebrafish. We anticipate that the smart probe DEVDCS-Gd-CBT could be applied for T1-weighted MRI of apoptosis-related diseases in the clinic in the future.

Characterization of the genomic and transcriptional structure of chicken NRG4 gene.

Neuregulin 4 (NRG4) is an important adipocytokine, which plays crucial roles in maintaining energy balance, regulating glucose and lipid metabolism, and preventing non-alcoholic fatty liver disease in mammals. At present, the genomic organization, transcript and protein isoforms of human NRG4 gene have been fully explored. Previous studies in our laboratory have shown that the NRG4 gene is expressed in chicken adipose tissue, but the chicken NRG4 (cNRG4) genomic structure, transcript and protein isoforms are still unknown. To this end, in this study, the genomic and transcriptional structure of the cNRG4 gene were systematically investigated using rapid amplification of cDNA ends (RACE) and reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the coding region (CDS) of the cNRG4 gene was small, but it had a very complex transcriptional structure characterized by multiple transcription start sites, alternative splicing, intron retention, cryptic exons, and alternative polyadenylation, thus leading to production of four 5?UTR isoforms (cNRG4 A, cNRG4 B, cNRG4 C, and cNRG4 D) and six 3?UTR isoforms (cNRG4 a, cNRG4 b, cNRG4 c, cNRG4 d, cNRG4 e, and cNRG4 f) of the cNRG4 gene. The cNRG4 gene spanned 21,969 bp of genomic DNA (Chr.10:3,490,314~3,512,282) and consisted of 11 exons and 10 introns. Compared with the cNRG4 gene mRNA sequence (NM_001030544.4), two novel exons and one cryptic exon of the cNRG4 gene were identified in this study. Bioinformatics analysis, RT-PCR, cloning and sequencing analysis showed that the cNRG4 gene could encode three protein isoforms (cNRG4-1, cNRG4-2 and cNRG4-3). This study lays a foundation for further research on the function and regulation of the cNRG4 gene.

[A cross-sectional study of enterovirus nucleic acid test with throat swabs for term late neonates during coronavirus disease 2019]. / æ–°åž‹å† çŠ¶ç— æ¯’æ„ŸæŸ“æœŸé—´è¶³æœˆçš„æ™šæœŸæ–°ç”Ÿå„¿å’½æ‹­å­è‚ é“ç— æ¯’æ ¸é ¸æ£€æµ‹æ¨ªæ–­é¢ç ”ç©¶.

OBJECTIVES: To investigate the positive rate of enterovirus (EV) nucleic acid in throat swabs of term late neonates hospitalized during the coronavirus disease 2019 (COVID-19) epidemic and the clinical characteristics of the neonates. METHODS: A single-center cross-sectional study was performed on 611 term late infants who were hospitalized in the neonatal center from October 2020 to September 2021. Throat swabs were collected on admission for coxsackie A16 virus/EV71/EV universal nucleic acid testing. According to the results of EV nucleic acid test, the infants were divided into a positive EV nucleic acid group (8 infants) and a negative EV nucleic acid group (603 infants). Clinical features were compared between the two groups. RESULTS: Among the 611 neonates, 8 tested positive for EV nucleic acid, with a positive rate of 13.1‰, among whom 7 were admitted from May to October. There was a significant difference in the proportion of infants contacting family members with respiratory infection symptoms before disease onset between the positive and negative EV nucleic acid groups (75.0% vs 10.9%, P<0.001). There were no significant differences between the two groups in demographic data, clinical symptoms, and laboratory test results (P>0.05). CONCLUSIONS: There is a certain proportion of term late infants testing positive for EV nucleic acid in throat swabs during the COVID-19 epidemic, but the proportion is low. The clinical manifestations and laboratory test results of these infants are non-specific. Transmission among family members might be an important cause of neonatal EV infection.

Enzymatic Self-Assembly of Adamantane-Peptide Conjugate for Combating Staphylococcus aureus Infection.

Staphylococcus aureus (S. aureus) remains a leading cause of bacterial infections. However, eradication of S. aureus infections with common antibiotics is increasingly difficult due to outbreaks of drug resistance. Therefore, new antibiotic classes and antibacterial strategies are urgently in demand. Herein, it is shown that an adamantane-peptide conjugate, upon dephosphorylation by alkaline phosphatase (ALP) constitutively expressed on S. aureus, generates fibrous assemblies in situ to combat S. aureus infection. By attaching adamantane to a phosphorylated tetrapeptide Nap-Phe-Phe-Lys-Tyr(H2 PO3 )-OH, the rationally designed adamantane-peptide conjugate Nap-Phe-Phe-Lys(Ada)-Tyr(H2 PO3 )-OH (Nap-FYp-Ada) is obtained. Upon bacterial ALP activation, Nap-FYp-Ada is dephosphorylated and self-assembles into nanofibers on the surface of S. aureus. As revealed by cell assays, the assemblies of adamantane-peptide conjugates interact with cell lipid membrane and thereby disrupt membrane integrity to kill S. aureus. Animal experiments further demonstrate the excellent potential of Nap-FYp-Ada in the treatment of S. aureus infection in vivo. This work provides an alternative approach to design antimicrobial agents.

Enzymatic Nanosphere-to-Nanofiber Transition and Autophagy Inducer Release Promote Tumor Chemotherapy.

Chemotherapy has remained an effective and predominant cancer treatment for the past decades, but is hampered by its low response rate and severe systemic toxicity. Combination chemotherapies are proposed to address these issues, yet their therapeutic outcomes are still far from satisfactory. Thus, it is urgent to develop novel strategies to promote tumor chemosensitivity while reducing toxic side effects of chemotherapeutics. Herein, employing a rationally designed peptide conjugate Nap-Phe-Phe-Lys(SA-AZD8055)-Tyr(H2 PO3 )-OH (Nap-AZD-Yp), a novel approach of simultaneous intracellular nanofiber formation and autophagy inducer release is proposed for selectively sensitizing tumor to chemotherapy. Upon sequential catalyses of alkaline phosphatase and carboxylesterase, Nap-AZD-Yp undergoes nanosphere-to-nanofiber transition accompanied by autophagy inducer AZD8055 release in cancer cells. Cell experiments show enhanced endocytosis of anticancer drug doxorubicin and inhibition of cell migration due to the intracellular nanofiber formation. The released AZD8055 further activates excessive autophagy of cancer cells, sensitizing them to chemotherapy. Animal experiment results suggest Nap-AZD-Yp can significantly enhance the therapeutic effects of doxorubicin on tumors while mitigate its toxic adverse effects on normal tissues. It is anticipated that the "smart" concept in this work c be widely employed to develop novel combinational therapies for the treatment of cancers and other diseases in near future.

Glutathione-Depleting Nanomedicines for Synergistic Cancer Therapy.

Cancer cells frequently exhibit resistance to various molecular and nanoscale drugs, which inevitably affects the drugs' therapeutic outcomes. Overexpression of glutathione (GSH) has been observed in many cancer cells, and solid evidence has corroborated the resulting tumor resistance to a variety of anticancer therapies, suggesting that this biochemical characteristic of cancer cells can be developed as a potential target for cancer treatments. The single treatment of GSH-depleting agents can potentiate the responses of the cancer cells to different cell death stimuli; therefore, as an adjunctive strategy, GSH depletion is usually combined with mainstream cancer therapies for enhancing the therapeutic outcomes. Propelled by the rapid development of nanotechnology, GSH-depleting agents can be readily constructed into anticancer nanomedicines, which have shown a steep rise over the past decade. Here, we review the common GSH-depleting nanomedicines which have been widely applied in synergistic cancer treatments in recent years. Some current challenges and future perspectives for GSH depletion-based cancer therapies are also presented. With the understanding of the structure-property relationship and action mechanisms of these biomaterials, we hope that the GSH-depleting nanotechnology will be further developed to realize more effective disease treatments and even achieve successful clinical translations.

Advances of functional consequences and regulation mechanisms of alternative cleavage and polyadenylation.

During the maturation of pre-mRNAs and some lncRNAs, their 3'ends are cleaved and polyadenylated. The cleavage and polyadenylation (C/P) require the presence of a polyadenylation signal (PAS) at the RNA 3?end. Most eukaryotic genes have multiple PASs, resulting in alternative cleavage and polyadenylation (APA). APA leads to transcript isoforms with different coding potentials and/or variable 3?UTRs. The 3'UTR affects mRNA stability, translation, transportation, and cellular localization. Therefore, APA is an important mechanism of posttranscriptional gene regulation in eukaryotes. In recent years, whole genome sequencing of animals, plants and yeast has revealed that APA is pervasive in eukaryotes, and the functional consequences and regulation of APA have been studied. To date, many cis-acting regulatory elements and trans-acting factors for APA regulation have been identified. In this review, we summarize the recent advances in the functional consequences and regulation of APA and discuss the future directions, aiming to provide clues and references for future APA study.

[Cloning and expression analysis of chicken circular transcript of insulin degrading enzyme gene].

Insulin-degrading enzyme (IDE) is a highly conserved metallopeptidase that functions in the catabolism of bioactive peptides. In our previous study, we identified a putative circular transcript in that chicken insulin-degrading enzyme (IDE) gene through analyzing a high throughput sequencing result. Here we set to confirm the circular transcript of IDE (circIDE) and explore its expression regularity in normal barred Plymouth chicken. The circIDE was confirmed by PCR amplification and sequencing. The circular structure of circIDE was determined by RNase R processing and reverse transcription experiments. Then we analyzed the spatiotemporal expression pattern of circIDE and IDE mRNA and compared the differential expression of circIDE and IDE mRNA in the normal barred Plymouth chicken and the dwarf ones. The results showed that the full length of chicken circIDE was 1332 nt, divided form exon 2-11 of the IDE gene. RNase R tolerance analysis showed that chicken circIDE had the general characteristics of circular molecule, and was highly resistant to RNase R. The random primers had higher transcription efficiency than the oligo-d(T)18 primers, confirming that circIDE is a circular structured molecule without poly(A). circIDE was highly expressed in the liver and heart tissues but less in the muscle tissues of leg and breast in normal chickens at the age of 1 and 12 weeks. The expression profile of circIDE in liver tissue showed that circIDE level was lower in1 to 6 weeks and then became higher after 8 weeks of age. The expression of circIDE in liver tissue was significantly higher in normal chicken than that in dwarf barred Plymouth chicken (P<0.05). This study confirmed a circIDE strucutre in chicken IDE gene and uncovered its expression regularity. We demonstrated that the expression level of circIDE in the liver tissue was higher in normal barred Plymouth chicken compared to dwarf species. This study paves the way for further understanding the biological function of chicken circIDE, including its roles in regulating chicken growth and development.

Large mode area microstructured fiber supporting 56 super-OAM modes.

In this paper, a kind of super-mode orbital angular momentum microstructured fiber (SM-OAM-MSF) is proposed. By introducing 20 Ge-doped equiangular cylindrical inclusions in the ring-core region, mode coupling mechanism is employed in the formation of super-OAM (SOAM) modes. Specifically, the double degenerated out-of-phase SMs are first generated by the coupling of individual core mode, then the quadruple degenerated SOAM modes are formed by combining two components of the out-of-phase SMs with a phase difference of ±π/2. Theoretical analysis and numerical results reveal that the effective index difference (Δneff) between adjacent out-of-phase SM groups are strongly influenced by the parameters of the individual core except the ring-core's width. Therefore, large mode area and SOAM modes' index separation larger than 1.0×10-4 can be achieved simultaneously in our proposed SM-OAM-MSF. Through careful fiber design, HE1,1 and HE2,1 are used in the formation of SMs and SOAM modes. Simulations show that all the nine SOAM groups originating from HE1,1 mode and the first five SOAM groups stemming from normal coupling of HE2,1 mode can be supported above 1.0µm, that are 56 SOAM modes in total. The highest purity is 99.86% for SOAM±2,1±,5 mode. And the maximum mode area (Aeff) value reaches up to 638.88µm2 at 1.55µm, which is nearly eight times larger compared to that of conventional ring-core MSFs.

Beclin 1, Bcl-2 and Autophagy.

Beclin 1 is the first mammalian autophagy protein identified as a novel Bcl-2-interacting protein. Subsequent studies have demonstrated that this landmark protein is essential for autophagy. By investigating the interaction between Bcl-2 and Beclin 1, key molecular mechanisms of mammalian autophagy regulation have been discovered. In this chapter, we will first review the discovery of Beclin 1 and then focus on the mechanisms of Bcl-2 and Beclin 1 regulation and their effect on autophagy regulation. Finally, we summarize the evidence related to the interaction of Bcl-2 and Beclin 1 and the involvement of these proteins in human diseases such as cancers, neurodegenerative diseases and infectious diseases.

Association Between MTHFR Genetic Polymorphism and Parkinson's Disease Susceptibility: A Meta-analysis.

Folate metabolism plays quite a critical role in Parkinson's disease (PD). Previous published research works have studied the link existing between the folate metabolism genetic polymorphisms and PD susceptibility; nevertheless, the results continue having controversies and inconclusiveness. Accordingly, we carried out the present meta-analysis for the assessment of the potential link between the folate metabolism genetic polymorphisms and the susceptibility to PD. In addition we carried out a literature search in the PubMed, EMBASE, Cochrane Library, and WanFang databases till November 10, 2018. The odds ratios (ORs) with corresponding 95% credible interval (95%CI) were put to use for evaluating the strength of the association of three folate metabolism genetic polymorphism ( C677T, A1298C, and A2756G) with the susceptibility to PD. Each statistical analysis was carried out with the use of STATA 15.0. An aggregate of twenty-one case-control investigations were retrieved, which involved 3,944 PD patients and 4,412 controls. We discovered the existence of no substantial link between the C677T and A1298C polymorphism and PD risk in any genetic framework comparisons. With regard to A2756G polymorphism, we discovered that there was an association between the A2756G genetic polymorphism and an augmented threat of PD in the co-dominant genetic framework (GG vs. AA: OR=1.86, 95%CI=1.02-3.37, P=0.042) and the recessive genetic model (GG vs. GA+AA: OR=1.90, 95%CI=1.06-3.41, P=0.031). To summarize, our research work indicates that the A2756G polymorphism of the folate metabolism gene had an association with an augmented threat of PD. Also, A1298C polymorphisms is unlikely to significantly contribute towards the susceptibility to PD. Further large-scale case-control studies are still required.

A genetics laboratory class to analyze early and late feather traits of chicken.

With the implementation of the "Education and Training Program for Outstanding Agricultural and Forestry Talents" in our country, our university established the "Outstanding Class" for students majoring in the animal science. We also carried out a series of educational management and curriculum reforms to cultivate students' systematic model of thinking and the ability of technology innovation. In this paper, we designed a comprehensive experiment that focused on analyzing early and late feather genetic traits of chicken. The students initially observed the phenotype of chickens and gradually were led into genetics analysis. We introduced the breeding practice, and guided the students to use genetic theories to breed chick strains of early and late feather traits. The experiment is not only based on the sex-linkage theory and sex determination mechanism, but also molecular genetics technologies, such as genomic DNA extraction, amplification, enzyme digestion and electrophoresis. Conducting this experiment can enhance students' comprehensive analysis ability and professional skills, as well as be beneficial to cultivate their scientific research interests and curiosity on animal sciences. Thus, we integrated the genetics theories into animal breeding practice that meet the requirement of comprehensive applied talents of animal science specialty. The teaching ideas and methods described in this paper can be applied to other biological experiment teaching practice.

Diffusion-weighted imaging in evaluating the efficacy of concurrent chemoradiotherapy in the treatment of non-small cell lung cancer.

OBJECTIVE: To explore the predictive value of diffusion-weighted imaging (DWI) in evaluating the short-term efficacy of concurrent chemoradiotherapy (CCRT) in the treatment of patients with non-small cell lung cancer (NSCLC). METHODS: A total of 192 patients with NSCLC were selected and treated with CCRT. Dynamic contrast-enhanced magnetic resonance imaging combined with DWI was performed on all patients before and after CCRT treatment. Correspondingly, apparent diffusion coefficient (ADC) values were recorded before treatment (ADCpre), during treatment (ADCmid), and after treatment (ADCpost). Tumor response was evaluated as complete response (CR), partial response (PR), stable disease (SD), or progressive disease (PD). Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic power of quantitative DWI parameters in predicting the short-term efficacy of CCRT for patients with NSCLC. RESULTS: There were 21 patients with CR, 82 with PR, 77 with SD, and 12 with PD. The ADCpre was negatively correlated with tumor regression rate, whereas ADCmid, ADCpost, and their respective change rates ∆ADCmid and ∆ADCpost were positively related to tumor regression rate. The ROC curve analysis suggested ADCpre = 1.38 × 10-3 mm2/s, ∆ADCmid = 14.14%, and ∆ADCpost = 20.39% as thresholds to predict the short-term efficacy of CCRT, with corresponding areas under the curve of 0.637, 0.743, and 0.752, respectively. CONCLUSIONS: These findings indicate that DWI provides promising predictive value in evaluating the short-term efficacy of CCRT in the treatment of patients with NSCLC.

Transcription factor EB is involved in autophagy-mediated chemoresistance to doxorubicin in human cancer cells.

Transcription factor EB (TFEB) is a master regulator of autophagy activity and lysosomal biogenesis, but its role in autophagy-mediated cell survival and chemotherapy resistance is not completely understood. In this study, we explored whether TFEB played an important role in autophagy-mediated chemotherapy resistance in human cancer LoVo and HeLa cells in vitro. Treatment of human colon cancer LoVo cells with doxorubicin (0.5 µmol/L) induced autophagy activation and nuclear translocation of TFEB, which resulted from inactivation of the mTOR pathway. In both LoVo and HeLa cells, overexpression of TFEB enhanced doxorubicin-induced autophagy activation and significantly decreased doxorubicin-induced cell death, whereas knockdown of TFEB with small interfering RNA blocked doxorubicin-induced autophagy and significantly enhanced the cytotoxicity of doxorubicin. In LoVo cells, autophagy inhibition by 3-methyladenine (3-MA) or knockdown of autophagy-related gene Atg5 increased cell death in response to doxorubicin, and abolished TFEB overexpression-induced chemotherapy resistance, suggesting that the inhibition of autophagy made cancer cells more sensitive to doxorubicin. The results demonstrate that TFEB-mediated autophagy activation decreases the sensitivity of cancer cells to doxorubicin.

Lysosomal Proteolysis Is Associated With Exercise-Induced Improvement of Mitochondrial Quality Control in Aged Hippocampus.

Exercise improves cognitive function in older adults, but the underlying mechanism is largely unknown. Both lysosomal degradation and mitochondrial quality control decline with age. We hypothesized that exercise ameliorates age-related cognitive decline through the improvement of mitochondrial quality control in aged hippocampus, and this effect is associated with lysosomal proteolysis. Sixteen to eighteen-month old male Sprague Dawley rats underwent swim exercise training for 10 weeks. The exercise regimen prevented cognitive decline in aged rats, reduced oxidative stress, and rejuvenated mitochondria in the aged hippocampus. Exercise training promoted mitochondrial biogenesis, increased mitochondrial fusion and fission, and activated autophagy/mitophagy in aged hippocampal neurons. Lysosomal inhibitor chloroquine partly blocked beneficial effects of exercise on cognitive function, oxidative stress, autophagy/mitophagy, and mitochondrial quality control in aged rats. These results suggest that preservation of cognitive function by long-term exercise is associated with improvement of mitochondrial quality control in aged hippocampus and that lysosomal degradation is required for this process. Our findings suggest that exercise training or pharmacological regulation of mitochondrial quality control and lysosomal degradation may be effective strategies for slowing down age-related cognitive decline.

Blockade of NF-κB and MAPK pathways by ulinastatin attenuates wear particle-stimulated osteoclast differentiation in vitro and in vivo.

Ulinastatin, a urinary trypsin inhibitor (UTI), is widely used to clinically treat lipopolysaccharide (LPS)-related inflammatory disorders recently. Adherent pathogen-associated molecular patterns (PAMPs), of which LPS is the best-studied and classical endotoxin produced by Gram-negative bacteria, act to increase the biological activity of osteopedic wear particles such as polymethyl-methacrylate (PMMA) and titanium particles in cell culture and animal models of implant loosening. The present study was designed to explore the inhibitory effect of UTI on osteoclastogenesis and inflammatory osteolysis in LPS/PMMA-mediated Raw264.7 cells and murine osteolysis models, and investigate the potential mechanism. The in vitro study was divided into the control group, LPS-induced group, PMMA-stimulated group and UTI-pretreated group. UTI (500 or 5000 units/ml) pretreatment was followed by PMMA (0.5 mg/ml) with adherent LPS. The levels of inflammatory mediators including tumour necrosis factor-α (TNF-α), matrixmetallo-proteinases-9 (MMP-9) and interleukin-6 (IL-6), receptor activation of nuclear factor NF-κB (RANK), and cathepsin K were examined and the amounts of phosphorylated I-κB, MEK, JNK and p38 were measured. In vivo study, murine osteolysis models were divided into the control group, PMMA-induced group and UTI-treated group. UTI (500 or 5000 units/kg per day) was injected intraperitoneally followed by PMMA suspension with adherent LPS (2×108 particles/25 µl) in the UTI-treated group. The thickness of interfacial membrane and the number of infiltrated inflammatory cells around the implants were assessed, and bone mineral density (BMD), trabecular number (Tb.N.), trabecular thickness (Tb.Th.), trabecular separation (Tb.Sp.), relative bone volume over total volume (BV/TV) of distal femur around the implants were calculated. Our results showed that UTI pretreatment suppressed the secretion of proinflammatory cytokines including MMP-9, IL-6, TNF-α, RANK and cathepsin K through down-regulating the activity of nuclear factor kappa B (NF-κB) and MAPKs partly in LPS/PMMA-mediated Raw264.7 cells. Finally, UTI treatment decreased the inflammatory osteolysis reaction in PMMA-induced murine osteolysis models. In conclusion, these results confirm the anti-inflammatory potential of UTI in the prevention of particle disease.

Augmentative locking plate with autologous bone grafting for distal femoral nonunion subsequent to failed retrograde intramedullary nailing.

OBJECTIVE: To explore the indications and efficacy of augmentative locking compression plate (LCP) or less invasive stabilization system (LISS)with autogenous bone grafting (BG) in treating distal femoral nonunion subsequent to failed retrograde intramedullary nailing (RIN). METHODS: A retrospective study was performed for 21 patients with distal femoral nonunion subsequent to failed RIN, who received therapy with either augmentative LCP (n = 11) or LISS with autogenous BG (n = 13). Operation time, time to union, union rate, time to renonunion, complication rate and SF-36 scores a year after hardware removal were compared between the two groups. RESULTS: The bone union occurred in 13/13 (100%) cases in augmentative LISS group versus 9/11 (81.8%) cases in augmentative LCP group [odds ratio (OR) = 3.21, 95% confidence interval (CI) 0.7-13]. Time to union, time to renonunion, complication rate of the augmentative LCP group were significantly more than that of the augmentative LISS with autogenous BG group (p = 0.023, p = 0.021 and p = 0.033). No significant difference was found in the average operation time of two groups (p = 0.121). At the follow-up a year after hardware removal, statistically significant HRQOL improvement in the augmentive LISS group was measured at the level of pain (p = 0.003) and general health perception (p = 0.011), as compared to the augmentive LCP group. CONCLUSIONS: We suggest augmentative LCP, for distal femoral nonunios after RIN, may be optimal for that of typeAO33A fractures, whereas augmentative LISS for that of typeAO33C fractures more.

Linoleic acid induces red blood cells and hemoglobin damage via oxidative mechanism.

Hidden blood loss typically occurs following total hip arthroplasty (THA) and total knee arthroplasty (TKA) and is thought to be related to free fatty acid (FFA). To study the effect of linoleic acid on red blood cells and to examine the pathogenesis of hidden blood loss in vivo, we generated an animal model by injecting linoleic acid into the tail veins of rats. We collected blood samples and determined red blood cell count (RBC) and levels of hemoglobin (Hb), as well as the oxidation and reducing agents in the blood, including glutathione peroxidase (GSH-PX), total superoxide dismutase (T-SOD), hydrogen peroxide (H2O2), and ferryl hemoglobin (Fe4+=O2-), which is generated by the oxidation of Hb. Hidden blood loss occurred when linoleic acid was administered at a concentration of 60 mmol/L; RBC and Hb levels were significantly reduced by 24 h post-injection. This was followed by erythrocyte deformation, reduced activity of GSH-PX and T-SOD, and decreased levels of H2O2. This was accompanied by an increase in ferryl species, which likely contributes to oxidative stress in vivo. Our findings suggest that linoleic acid enhances acute red blood cell injury. Hb and RBC began to increase by 72 h, potentially resulting from linoleic acid metabolism. Thus, elevated levels of linoleic acid in the blood cause acute oxidative damage to red blood cells, eventually leading to partial acute anemia. These findings highlight the pathophysiology underlying hidden blood loss.