Titanium elastic nailing versus locking compression plating in school-aged pediatric subtrochanteric femur fractures

The treatment of children between 5 and 12 years of age suffering from subtrochanteric femoral fracture is challenging. The optimal choice of internal fixation for these patients is controversial. The purpose of this study is to compare the outcomes and complications of titanium elastic nail and open reduction with plate fixation of subtrochanteric femur fractures in school-aged children.A total of 67 children aged 5 to 12 years with subtrochanteric femur fractures treated with titanium elastic nails or open plating were identified at our institution from January 2007 to December 2017. We retrospectively compared 39 children treated with titanium elastic nails with 28 children treated with open reduction and plate fixation. The data included age, sex, body weight, fracture pattern, operation time, blood loss, and length of hospitalization. The follow-up investigations included radiograph of pelvis, bilateral hip range of motion, bilateral femoral neck shaft angle, and length of lower extremity. The outcomes were classified according to Flynn classification as excellent, satisfactory, or poor. All the demographic characteristics were compared with statistical analyses.All 67 fractures united properly. No major postoperative complications were noted in both groups. No significant difference was found between the titanium elastic nail and open plating groups in terms of sex, fracture pattern, and length of hospitalization. We noted a significant difference between 2 groups in terms of age, weight, operation time, and blood loss. In total, we observed 24 excellent and 15 satisfactory results in the titanium elastic nail group, and 19 excellent results and 9 satisfactory results in the open plating group. There was no significant statistical difference between involved and uninvolved side of hip regarding range of motion and femoral neck shaft angle in both groups.Titanium elastic nail and pediatric hip plate fixation represent safe and effective methods in the treatment of subtrochanteric fractures in school-aged children. Titanium elastic nail internal fixation is a minimal invasive and simpler technique and suitable for young children of lower body weight. Open plate fixation is a more rigid fixation associated with a lower complication rate.

Effects of microRNA-24 targeting C-myc on apoptosis, proliferation, and cytokine expressions in chondrocytes of rats with osteoarthritis via MAPK signaling pathway

To investigate whether microRNA-24 (miR-24) targeting C-myc affects chondrocytes of rats with osteoarthritis (OA) via the MAPK signaling pathway. Thirty rats were assigned as a sham group and an OA group (established as OA rat models by cutting the anterior cruciate ligaments and removing 1/3 medial meniscus). TUNEL staining and immunohistochemistry were conducted for cell apoptosis index (AI) and positive expression rate of C-myc protein. Enzyme-linked immuno sorbent assay (ELISA) was carried out for serum level of IL-1β and TNF-α. Primary chondrocytes were assigned into the blank, negative control (NC), miR-24 mimics, miR-24 inhibitors, siRNA-C-myc, and miR-24 inhibitors+siRNA-C-myc groups. The expressions of miR-24, C-myc, p38, ERK, JNK, IL-1β, and TNF-α in tissues and cells were detected using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and Western blotting. CCK8 assay and flow cytometry were performed for cell proliferation and apoptosis. The OA group showed higher IL-1β, TNF-α, AI, and C-myc than the sham group. C-myc is a target gene of miR-24. Compared with the blank group, the miR-24 mimics and siRNA-C-myc groups showed reduced expression of C-myc, IL-1β, TNF-α, p38, p-p38, ERK, p-ERK, JNK, and p-JNK, apoptosis rate yet increased cell proliferation; however, the miR-24 inhibitors group exhibited an opposite trend. The miR-24 inhibitors+siRNA-C-myc group presented a same tendency compared to the siRNA-C-myc group. Upregulated miR-24 downregulates C-myc could suppress apoptosis and promote proliferation of chondrocytes to prevent the occurrence and subsequent progression of OA via inactivating the MAPK signaling pathway.

Egr1 deficiency disrupts dynamic equilibrium of chondrocyte extracellular matrix through PPARγ/RUNX2 signaling pathways

BACKGROUND

This study is to investigate the effect of Egr1 on the mineralization and accumulation of chondrocyte extracellular matrix.

METHODS

The femoral heads of patients of various heights were collected. Egr1 knockout mice were used. Their limb lengtha nd body weight were assessed. The bone characteristics were detected by micro-CT scan and histological staining. Immature murine articular chondrocytes (iMACs) were isolated. Gross morphology was observed by histological staining. Relevant mRNA and protein expression were detected by qRT-PCR and Western blot, respectively. the related proteins were observed by immunohistochemical staining and immunofluorescence assay. Chromatin immunoprecipitation and reporter gene assay were also used. TUNEL was used to detect apoptosis.

RESULTS

It was found that shorter patients had reduced Egr1 expression levels in the hypertrophic cartilage zone of the femoral head. In addition, Egr1 knockout mice exhibited reduced body size. Micro-CT analysis showed that these mice also had reduced bone volume. Safranin-O staining showed that the extracellular matrix of these mice exhibited a relatively limited degree of mineralization, and TUNEL staining showed reduced cell apoptosis levels. After transfecting the iMACs with dominant-negative Egr1 adenoviruses to inhibit Egr1, the enzymes of Adamst4, Adamst5, Mmp3 and Mmp13 were significantly upregulated. ChIP and luciferase assays revealed that Egr1 might regulate the chondrocyte extracellular matrix by the PPARγ/RUNX2 signaling pathways.

CONCLUSION

Egr1 has an important regulatory effect on the dynamic equilibrium of the chondrocyte extracellular matrix, which may be achieved through the PPARγ/RUNX2 signaling pathways.

Biomagnification and enantiomeric profiles of organochlorine pesticides in food web components from Zhoushan Fishing Ground, China

Trophodynamics and chiral signatures of organochlorine pesticides (OCPs), including dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and chlordanes in a food web from Zhoushan Fishing Ground, China, were studied. Residues of OCPs in all teleost fishes were within food safety levels. Strong positive correlations were found between trophic levels (TLs) and wet weight concentrations of target chemicals, with trophic magnification factors (TMFs) from 4.17 to 9.77. Lipid contents and TLs significantly correlated, which indirectly affect the bioaccumulation processes of OCPs. The consistently racemic EF values of α-HCH, as well as invariability of the relative proportions of HCH isomers in different marine species implied that HCHs in animals originate directly from the surrounding environment. However, in vivo biotransformation and/or elimination of o,p'-DDT cannot be precluded. TMFs of the individual enantiomers further suggest that the influence of achiral biotransformation is too minor to induce enantioselective biomagnification of chiral OCPs through the studied food web.

Apoptosis of posterior silk gland of Bombyx mori during spinning period and the role of PI3K/Akt pathway

Bombyx mori is an economic insect of the Lepidoptera. Its posterior silk gland (PSG) is an important organ for fibroin synthesis. In order to study the occurrence of apoptosis in PSG and the role of PI3K/Akt signaling pathway during spinning period, changes in morphology of silk gland, expressions of fibroin components Fib-H, Fib-L and P25 and Akt, TOR2, P70S6K and S6 in PI3K/Akt pathway, expressions of apoptosis related genes caspase-3, caspase-9 and activity of caspase-3 were explored. The results showed that the morphology of silk gland dramatically degenerated; transcription of Fib-H, Fib-L, and P25 gradually declined with time; and Fib-L protein level reduced by 0.6-fold at 72 h. Moreover, the transcription levels of Akt, TOR2, P70S6K, and S6 also decreased by 0.3-, 0.8-, 0.7-, and 0.1-fold, respectively, indicating that the downregulation of PI3K/Akt signaling pathway could lead to reduction in fibroin synthesis. In addition, the transcription levels of caspase-3 and caspase-9 increased by 1.3- and 3.6-fold, respectively, and the enzyme activity of caspase-3 grew at a maximum of 1.6-fold. The results showed the occurrence of apoptosis in PSG during spinning period. In conclusion, the present study indicated that both the decline in fibroin components and the increase in apoptosis-related genes were regulated by PI3K/Akt signaling pathway during spinning period, which shed new light on the functions of PI3K/Akt signaling pathway.

Locomotor activity of rats with SCI is improved by dexmedetomidine by targeting the expression of inflammatory factors

Dexmedetomidine, a well‑known selective α‑2 adrenoceptor agonist, inhibits the apoptosis of neurons and protects other organs from oxidative damage. In the present study, the effect of dexmedetomidine on spinal cord injury (SCI) in a rat model was investigated. The SCI rat model was prepared using the weight‑drop method, and the effect of dexmedetomidine on locomotor activity was analyzed using the Basso, Beattie and Bresnahan (BBB) rating scale. Western blot analysis was used to observe changes in the expression of apoptosis‑related proteins, including B‑cell lymphoma 2 (Bcl‑2) and Bcl‑2‑associated X protein (Bax). The results revealed that treatment of the SCI rats with dexmedetomidine at a dose of 50 mg/kg significantly prevented the formation of edema in the tissues of the spinal cord. Dexmedetomidine also inhibited the SCI‑induced accumulation of neutrophils in the spinal cord. The BBB scores were significantly increased (P<0.05) in the rats with SCI treated with dexmedetomidine after 10 days. The results of grid walking test revealed a marked decrease in the number of missteps following 10 days of dexmedetomidine treatment. The expression levels of tumor necrosis factor (TNF)‑α and interleukin (IL)‑1β were significantly reduced (P<0.05) in the spinal cord tissues of the dexmedetomidine group, compared with those in the control group of rats. Dexmedetomidine treatment following SCI exerted an inhibitory effect on the SCI‑induced increase in the expression of Bax. The expression of Bcl‑2 was increased in the dexmedetomidine treated rats, compared with that in the control group. Taken together, dexmedetomidine improved the locomotor activity of the rats through the inhibition of edema, reduction in the expression levels of TNF‑α and IL‑1β, and inhibition of the induction of apoptosis. Therefore, dexmedetomidine may be of therapeutic importance for patients with SCI.

Near Infrared Light Sensitive Ultraviolet-Blue Nanophotoswitch for Imaging-Guided "Off-On" Therapy

Photoswitchable materials are important in broad applications. Recently appeared inorganic photoswitchable upconversion nanoparticles (PUCNPs) become a competitive candidate to surmount the widespread issue of the organic counterparts -photobleaching. However, current PUCNPs follow solely Yb³⁺/Nd³⁺ cosensitizing mode, which results in complex multilayer doping patterns and imperfectness of switching in UV-blue region. In this work, we have adopted a new strategy to construct Nd³⁺ free PUCNPs-NaErF₄@NaYF₄@NaYbF₄:0.5%Tm@NaYF₄. These PUCNPs demonstrate the superior property of photoswitching. A prominent UV-blue emission from Tm³⁺ is turned on upon 980 nm excitation, which can be completely turned off by 800 nm light. The quasi-monochromatic red upconversion emission upon 800 nm excitation-a distinct feature of undoping NaErF₄ upconversion system-endows the PUCNPs with promising image-guided photoinduced "off-on" therapy in biomedicine. As a proof-of-concept we have demonstrated the imaging-guided photodynamic therapy (PDT) of cancer, where 800 nm excitation turns off the UV-blue emission and leaves the emission at 660 nm for imaging. Once the tumor site is targeted, excitation switching to 980 nm results in UV-blue emission and the red emission. The former is used to induce PDT, whereas the latter is to monitor the therapeutic process. Our study implies that this upconversion photoswitching material is suitable for real-time imaging and image-guided therapy under temporal and spatial control.

TiO2 NPs Alleviates High-Temperature Induced Oxidative Stress in Silkworms

Silkworm, Bombyx mori (L.; Lepidoptera: Bombycidae), is an economically important insect, which is sensitive to the environment and susceptible to oxidative damages at high temperature. Low concentrations of TiO2 NPs (titanium dioxide nanoparticles) can scavenge reactive oxygen species (ROS) produced by oxidative damages in vivo. To explore whether TiO2 NPs could alleviate oxidative damages of high temperature, the effects of TiO2 NPs treatment on silkworm growth, the levels of ROS and H2O2, as well as the transcription level of antioxidant-related genes were studied at 30°C. These results showed that TiO2 NPs treatment increased silkworm body weight by 6.0% and reduced the occurrence of irregular cocoon at 30°C. TiO2 NPs treatment at 30°C decreased ROS levels in fat body and increased expression of Hsp70, SOD by 5.70-fold at 48 h, TPx by 1.61-fold, CAT by 1.81-fold. These results indicated that TiO2 NPs treatment at 30°C could promote the expression of antioxidant genes and reduce oxidative stress and provide a new method to alleviate high-temperature induced oxidative stress to silkworm.

Factors affecting annual occurrence, bioaccumulation, and biomagnification of polycyclic aromatic hydrocarbons in plankton food webs of subtropical eutrophic lakes

The biological pump plays a critical role in the occurrence and fate of hydrophobic organic contaminants (HOCs) mostly in temperate and frigid oligotrophic waters. However, the factors for the long-term occurrence and fate of HOCs in subtropical eutrophic waters remain largely unknown. This study provides novel insights into biogeochemical and physical factors on the annual occurrence, bioaccumulation, and biomagnification of 16 polycyclic aromatic hydrocarbons (PAHs) in the plankton food webs of four Chinese subtropical eutrophic lakes by one-year simultaneous field observations for five compartments. The annual mean ΣPAH₁₆ in the water columns ranged from 359.69 ± 31.52 ng L^-1 to 682.69 ± 65.41 ng L^-1, and increased with the annual mean trophic state index, and phytoplankton biomass of these lakes, but was independent on the proximity of the lakes to urban areas. Biodilution effect played an important role in the occurrence of the PAHs in both phytoplankton and zooplankton. In contrast to previous studies in oligotrophic waters, not only the biological pump but also the equilibrium partitioning and the indirect influence of eutrophication (high pH induced by phytoplankton, and phytoplankton life cycling) modulated the annual occurrence of the PAHs in the water columns of these eutrophic lakes. Biphasic correlations were found between the bioaccumulation factors of the PAHs by plankton and the temperature (n = 97-136, R² = 0.06-0.24, p ≤ .008), and were related to plankton phenology. Bioaccumulation factors by plankton were dependent on the hydrophobicity of the PAHs (n = 16, R² = 0.27-0.31, p ≤ .023), and decreased with plankton biomass (n = 94-103, R² = 0.09-0.27, p ≤ .010). Trophic transfer of the PAHs from phytoplankton to zooplankton increased with phytoplankton biomass (n = 26, R² = 0.27, p = .004), and the temperature (n = 102-135, R² = 0.06-0.13, p ≤ .004), but decreased with lake trophic state index. Biomagnification only occurred during phytoplankton bloom periods.

Cloning and Functional Analysis of CncC and Keap1 Genes in Silkworm

CncC/keap1-ARE is an important signaling pathway for detoxification and antioxidation in Diptera and Coleoptera insects. However, such a signaling pathway has not been studied in Bombyx mori. In this study, BmCncC and Bmkeap1 genes were cloned, their amino acid sequences were analyzed, and each functional domain was mapped. Through phylogenetic analysis and sequence comparison among multiple species, we found that the Neh1 motif of CncC was highly conserved and the DLG motif was replaced by the DMG motif in Neh2. Conformational analysis showed that Neh1 of BmCncC forms a hairpin structure to bind DNA. The DGR region of Bmkeap1 contained abundant β sheets, which was involved in the recognition of Neh2. The transcription and expression analyses showed that both BmCncC and Bmkeap1 were highly expressed in the first instar larvae, and these two genes were expressed at a high level in the reproductive gland, fat body, and head. The transcriptional and expression levels of Akt and BmCncC in the fat body were significantly upregulated, and the expression of Bmkeap1 was downregulated after the phoxim treatment in silkworm. The transcriptional levels of CncC-regulated detoxification enzymes GST, cyp4M5, cyp6AE2, and cyp9G3 were increased by 4.026-, 5.246-, 3.821-, and 9.787-fold, respectively, while the activities of GST and CYP450 were increased by 1.521- and 1.231-fold, respectively, after phoxim treatment. These results indicated that the BmCncC/Bmkeap1 signaling pathway was activated by phoxim, leading to the expression of downstream detoxifying enzymes and detoxification of phoxim in silkworm.

Early growth response-1 negative feedback regulates skeletal muscle postprandial insulin sensitivity via activating Ptp1b transcription

Postprandial insulin desensitization plays a critical role in maintaining whole-body glucose homeostasis by avoiding the excessive absorption of blood glucose; however, the detailed mechanisms that underlie how the major player, skeletal muscle, desensitizes insulin action remain to be elucidated. Herein, we report that early growth response gene-1 ( Egr-1) is activated by insulin in skeletal muscle and provides feedback inhibition that regulates insulin sensitivity after a meal. The inhibition of the transcriptional activity of Egr-1 enhanced the phosphorylation of the insulin receptor (InsR) and Akt, thus increasing glucose uptake in L6 myotubes after insulin stimulation, whereas overexpression of Egr-1 decreased insulin sensitivity. Furthermore, deletion of Egr-1 in the skeletal muscle improved systemic insulin sensitivity and glucose tolerance, which resulted in lower blood glucose levels after refeeding. Mechanistic analysis demonstrated that EGR-1 inhibited InsR phosphorylation and glucose uptake in skeletal muscle by binding to the proximal promoter region of protein tyrosine phosphatase-1B (PTP1B) and directly activating transcription. PTP1B knockdown largely restored insulin sensitivity and enhanced glucose uptake, even under conditions of EGR-1 overexpression. Our results indicate that EGR-1/PTP1B signaling negatively regulates postprandial insulin sensitivity and suggest a potential therapeutic target for the prevention and treatment of excessive glucose absorption.-Wu, J., Tao, W.-W., Chong, D.-Y., Lai, S.-S., Wang, C., Liu, Q., Zhang, T.-Y., Xue, B., Li, C.-J. Early growth response-1 negative feedback regulates skeletal muscle postprandial insulin sensitivity via activating Ptp1b transcription.

Precisely Tailoring Upconversion Dynamics via Energy Migration in Core-Shell Nanostructures

Upconversion emission dynamics have long been believed to be determined by the activator and its interaction with neighboring sensitizers. Herein this assumption is, however, shown to be invalid for nanostructures. We demonstrate that excitation energy migration greatly affects upconversion emission dynamics. "Dopant ions' spatial separation" nanostructures are designed as model systems and the intimate link between the random nature of energy migration and upconversion emission time behavior is unraveled by theoretical modelling and confirmed spectroscopically. Based on this new fundamental insight, we have successfully realized fine control of upconversion emission time behavior (either rise or decay process) by tuning the energy migration paths in various specifically designed nanostructures. This result is significant for applications of this type of materials in super resolution spectroscopy, high-density data storage, anti-counterfeiting, and biological imaging.

Highly effective and chemically stable surface enhanced Raman scattering substrates with flower-like 3D Ag-Au hetero-nanostructures

We demonstrated flower-like 3D Ag-Au hetero-nanostructures on an indium tin oxide glass (ITO glass) for surface enhanced Raman scattering (SERS) applications. The flower-like 3D Ag nanostructures were obtained through electrodeposition with liquid crystalline soft template which is simple, controllable and cost effective. The flower-like 3D Ag-Au hetero-nanostructures were further fabricated by galvanic replacement reaction of gold (III) chloride trihydrate (HAuCl4·3H2O) solution and flower-like Ag. The flower-like Ag-Au hetero-nanostructure exhibited stronger SERS effects and better chemical stability compared with flower-like Ag nanostructure. The localized surface plasmon resonance (LSPR) spectra, field emission scanning electron microscope (FESEM) photos and Ag-Au ratios were studied which show that the surface morphology and shape of the flower-like Ag-Au hetero-nanostructure play significant roles in enhancing SERS. The flower-like 3D Ag-Au hetero-nanostructures fabricated by electrodeposition in liquid crystalline template and galvanic replacement reaction are simple, cheap, controllable and chemical stable. It is a good candidate for applications in SERS detection and imaging.

Catechin supplemented in a FOS diet induces weight loss by altering cecal microbiota and gene expression of colonic epithelial cells

The present study showed that catechin controlled rats’ body weights by altering gut microbiota and gene expression of colonic epithelial cells when supplemented into a high-fructo-oligosaccharide (FOS) diet.

Fenofibrate decreases the bone quality by down regulating Runx2 in high-fat-diet induced Type 2 diabetes mellitus mouse model

Background

This study is to investigate the effect of fenofibrate on the bone quality of Type 2 diabetes mellitus (T2DM) mouse model.

Methods

T2DM mouse model was induced by high-fat-diet, and the mice were treated with fenofibrate (100 mg/kg) (DIO-FENO) or PBS (DIO-PBS) for 4 weeks. The bone microstructure and biomechanical properties of femora were analyzed by micro-CT and 3-Point bending test. The protein expression was detected by immunohistochemical staining and Western blot. The cell apoptosis was evaluated by TUNEL staining. The Bcl2, caspase 3, and osteoblast marker genes were detected by RT-qPCR.

Results

The biomechanical properties of bones from DIO-FENO group were significantly lower than those in the control and DIO-PBS groups. Besides, the trabecular number was lower than those of the other groups, though the cortical porosity was decreased compared with that of DIO-PBS group because of the increase of apoptotic cells. The expression of osteocalcin and collagen I were decreased after treatment with fenofibrate in T2DM mice. Moreover, the cell viability was decreased after treated with different concentrations of fenofibrate, and the expression of Runx2 decreased after treated with high dose of fenofibrate.

Conclusion

Fenofibrate decreases the bone quality of T2DM mice through decreasing the expression of collagen I and osteocalcin, which may be resulted from the down regulation of Runx2 expression.