Imaging findings of inflammatory myofibroblastic tumor of sigmoid colon: literature review and case report.

Inflammatory myofibroblastic tumor (IMT) is an intermediate tumor composed of differentiated myofibroblastic spindle cells with inflammatory cell infiltration. It can occur in all parts of the body, with the lungs being the most common, while the tissues outside the lungs, including the sigmoid colon, are rare. Herein, we present a case of a 10-year-old girl with sigmoid IMT who presented to our hospital with abdominal pain. An abdominal computed tomography (CT) revealed a well-defined, slightly low-density mass in her lower abdomen that was not clearly demarcated from the sigmoid colon. The mass showed significant uneven enhancement on contrast-enhanced CT and increased fluorine-18 fluorodeoxyglucose (18F-FDG) uptake on positron emission tomography (PET). Moreover, a systematic review of the published literature on sigmoid IMT was conducted and its clinical and radiographic features were summarized to increase the understanding of this rare disease.

TAX1BP1 and FIP200 orchestrate non-canonical autophagy of p62 aggregates for mouse neural stem cell maintenance.

Autophagy plays a pivotal role in diverse biological processes, including the maintenance and differentiation of neural stem cells (NSCs). Interestingly, while complete deletion of Fip200 severely impairs NSC maintenance and differentiation, inhibiting canonical autophagy via deletion of core genes, such as Atg5, Atg16l1, and Atg7, or blockade of canonical interactions between FIP200 and ATG13 (designated as FIP200-4A mutant or FIP200 KI) does not produce comparable detrimental effects. This highlights the likely critical involvement of the non-canonical functions of FIP200, the mechanisms of which have remained elusive. Here, utilizing genetic mouse models, we demonstrated that FIP200 mediates non-canonical autophagic degradation of p62/sequestome1, primarily via TAX1BP1 in NSCs. Conditional deletion of Tax1bp1 in fip200 hGFAP conditional knock-in (cKI) mice led to NSC deficiency, resembling the fip200 hGFAP conditional knockout (cKO) mouse phenotype. Notably, reintroducing wild-type TAX1BP1 not only restored the maintenance of NSCs derived from tax1bp1-knockout fip200 hGFAP cKI mice but also led to a marked reduction in p62 aggregate accumulation. Conversely, a TAX1BP1 mutant incapable of binding to FIP200 or NBR1/p62 failed to achieve this restoration. Furthermore, conditional deletion of Tax1bp1 in fip200 hGFAP cKO mice exacerbated NSC deficiency and p62 aggregate accumulation compared to fip200 hGFAP cKO mice. Collectively, these findings illustrate the essential role of the FIP200-TAX1BP1 axis in mediating the non-canonical autophagic degradation of p62 aggregates towards NSC maintenance and function, presenting novel therapeutic targets for neurodegenerative diseases.

Case Report: Eosinophilic gastritis with pyloric stenosis in immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome.

Immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome is a rare X-linked recessive immunodeficiency caused by mutations in the forkhead box protein 3 (FOXP3) gene. IPEX is characterized by the onset of intractable diarrhea, type 1 diabetes mellitus (T1DM), and eczema in the early stages of life. The typical clinic triad for IPEX is not always seen. Here, we report a 15-year-old male patient with atypical IPEX syndrome complicated with severe eosinophilic gastritis (EG) and pyloric stenosis. The patient had noticeable eczema during the first year of life and had a history of food allergies. At the age of 3 years, the patient was diagnosed with EG, Helicobacter pylori (HP) infection, pyloric stenosis with recurrent vomiting, and failure to thrive. The patient did not respond to long-term symptomatic treatments in the following years, including methylprednisolone, proton pump inhibitors (PPI), L-glutamine and sodium gualenate granules, anti-HP therapy, and balloon dilation. At the age of 12 years, the patient received surgical interventions, including a laparoscopic jejunostomy feeding tube placement, gastrojejunal anastomosis bypass, and jejunal-jejunal end-to-side anastomosis. Intractable diarrhea and T1DM were not present in the patient. At the age of 14 years, the patient was diagnosed with IPEX syndrome due to a c.748-750del (p.Lys250del) mutation in the leucine zipper domain of the FOXP3 protein. The patient underwent matched sibling peripheral blood hematopoietic stem cell transplantation (HSCT) and showed good evolution after 3 months of HSCT. In summary, this case report provides information of unusual gastrointestinal findings in IPEX syndrome and highlights the need for increased awareness and early diagnosis of IPEX syndrome, which is vital for improving the patient's outcome.

Neuroprotective Effects of Curcumin against Oxygen-Glucose Deprivation/Reoxygenation-Induced Injury in Cultured Primary Rat Astrocyte by Improving Mitochondrial Function and Regulating the ERK Signaling Pathway.

Objectives: Curcumin (Cur) is a natural polyphenol isolated from turmeric and has potent anti-inflammatory and antioxidant activities. This study aimed to explore the effects and possible mechanisms of curcumin on oxygen-glucose deprivation/reoxygenation (OGD/R)-induced injury in cultured rat astrocyte primary cells. Methods: After screening for effective doses, the cultured rat astrocyte primary cells were divided into three groups: control, OGD/R, and OGD/R + curcumin (10 µM, 20 µM, and 40 µM). Cell viability was detected using CCK8 assays. The level of malondialdehyde and superoxide dismutase activity was determined using commercial kits. The endothelial nitric oxide synthase and adenosine triphosphate concentrations were determined by enzyme-linked immunosorbent assay. The mRNA levels of the inflammatory indexes interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-1ß were evaluated by quantitative reverse-transcription polymerase chain reaction. Annexin V-fluorescein isothiocyanate/propidium iodide was used to detect apoptosis. JC-1 was used to assess the mitochondrial membrane potential. The protein expression of apoptosis-related proteins (B-cell lymphoma-2 (Bcl-2), BCL-2-associated X (Bax), and cleaved caspase 3), mitochondria-related proteins (dynamin-related protein 1 (DRP1), phosphorylated DRP1 (p-DRP1), and mitofusin 2), and essential proteins of the extracellular signal-regulated kinase (ERK) signaling pathway (ERK1/2, p-ERK1/2) were analyzed by western blot. Results: Our data indicated that curcumin reversed OGD/R-induced cell viability loss, oxidative stress, inflammatory cytokine production, and cell apoptosis in a dose-dependent manner. Furthermore, curcumin attenuated OGD/R-induced mitochondrial dysfunction and ERK1/2 phosphorylation in a dose-dependent manner. Conclusions: Curcumin protected against OGD/R-induced injury in rat astrocyte primary cells through improving mitochondrial function and regulating the ERK signaling pathway.

Construction of AP003469.4-miRNAs-mRNAs ceRNA network to reveal potential biomarkers for hepatocellular carcinoma.

Studies have reported that the competing endogenous RNA (ceRNA) networks are related to disease progression and prognosis in patients with hepatocellular carcinoma (HCC). The roles and mechanisms of long-chain non-coding RNA AP003469.4 in HCC have remained unclear. Here, we explored the roles of AP003469.4 in HCC progression using bioinformatics, CCK-8, Transwell assay, etc. AP003469.4 targets miRNAs and these target genes were predicted by the LncBase Predicted v.2, miRDB, miRTarBase, and TargetScan databases. Then, AP003469.4-associated ceRNA network was constructed. Biological functions and mechanisms of differentially expressed genes in the ceRNA network were explored using GO and KEGG. Survival analysis and Cox regression analysis were used to screen prognostic genes and construct a prognostic risk model. The results revealed that AP003469.4, with the area under the curve of 0.9048, was highly expressed in HCC tissues. Increased expression of AP003469.4 was an independent risk factor for the dismal prognosis of HCC patients and was associated with the short overall and disease-free survival. Downregulation of AP003469.4 expression inhibited cell proliferation, cycle transition, invasion, and migration, and promoted cell apoptosis. There were 489 differentially expressed target genes in the ceRNA network, which were involved in several pathways, such as the MAPK signaling pathway, cell cycle, and p53 signaling pathway. The risk model was based on the DTYMK, ZFC3H1, CBX2, PKM, TTC26, ATG10, TAGLN2, CD3EAP, SHISA9, SLC1A5, KPNA2, SCML2, E2F7, and SMARCD1, which were the independent risk factors for poor prognosis of HCC patients. In general, interference with AP003469.4 expression might delay the progression of HCC. AP003469.4 related network could help to identify the hub target molecules in HCC progression, which might be candidate biomarkers for evaluating the prognosis of HCC patients.

Proof of Concept for Prevention of Natural Colonization by Oral Needle-Free Administration of a Microparticle Vaccine.

There has been substantial interest in the development of needle-free vaccine administration that has led to a variety of approaches for delivery through the skin for induction of a systemic immune response. The mucosal administration of vaccines has inherently been needle-free, but the simple application of vaccines on the mucosal surface by itself does not lead to mucosal immunity. Since many important bacterial infections develop after initial colonization of the upper respiratory tract of the host, prevention of colonization could not only prevent infection but also eliminate the reservoir of pathogens that reside exclusively in that ecologic niche. This study was designed to provide proof of concept for a needle-free immunization approach that would reduce or eliminate colonization and prevent infection. In order to accomplish this a microparticle vaccine preparation was delivered just below the oral mucosal epithelial cell layer where it would lead to a robust immune response. A vaccine antigen (mutant transferrin binding protein B) shown to be capable of preventing infection in pigs was incorporated into a polyphosphazene microparticle preparation and delivered by a needle-free device to the oral sub-epithelial space of pigs. This vaccination regimen not only provided complete protection from infection after intranasal challenge by Glaesserella parasuis but also eliminated natural colonization by this bacterium. Notably, the complete prevention of natural colonization was dependent upon delivery of the microparticle preparation below the epithelial layer in the oral mucosa as intradermal or intramuscular delivery was not as effective at preventing natural colonization. This study also demonstrated that a primary immunization in the presence of maternal antibody limited the resulting antibody response but a robust antibody response after the second immunization indicated that maternal antibody did not prevent induction of B-cell memory.

Reducing Neuron Apoptosis in the Pontine Micturition Center by Nerve Root Transfer for Restoration of Micturition Function after Spinal Cord Injury.

OBJECTIVE: The rate of neuronal apoptosis increases after spinal cord injury (SCI). Anastomosing the normal nerve roots above the SCI level to the injured sacral nerve roots can enhance the functional recovery of neurons. Therefore, we evaluated the effect of sacral nerve root transfer after SCI on pontine neuronal survival. METHODS: Sprague-Dawley rats were randomly divided into three groups: Group A, reconstruction of afferent and efferent nerve pathways of the bladder after SCI; Group B, SCI only; and Group C, control group. We examined pontine neuronal morphology using hematoxylin and eosin (H&E) staining after SCI and nerve transfer. Bcl-2 and Bax protein expression changes in the pontine micturition center were quantified by immunohistochemistry. The number of apoptotic neurons was determined by TUNEL staining. We examined pontine neuronal apoptosis by transmission electron microscopy (TEM) at different time points. RESULTS: H&E staining demonstrated that the number of neurons had increased in Group A, but more cells in Group B displayed nuclear pyknosis, with the disappearance of the nucleus. Compared with Group B, Group A had significantly higher Bcl-2 expression, significantly lower Bax expression, and a significantly higher Bcl-2/Bax ratio. The number of apoptotic neurons and neuron bodies in Group A was significantly lower than that in Group B, as indicated by TUNEL staining and TEM. CONCLUSIONS: These findings demonstrate that lumbosacral nerve transfer can reduce neuronal apoptosis in the pontine micturition center and enhance functional recovery of neurons. This result further suggests that lumbosacral nerve transfer can be used as a new approach for reconstructing bladder function after spinal cord injury.

Apolipoprotein D alleviates glucocorticoid-induced osteogenesis suppression in bone marrow mesenchymal stem cells via the PI3K/Akt pathway.

BACKGROUND: To clarify the role of apolipoprotein D (Apod) in alleviating glucocorticoid-induced osteogenesis suppression in bone marrow mesenchymal stem cells (MSCs) via the PI3K/Akt pathway, thus influencing the progression of osteoporosis (OP). METHODS: Osteogenesis in MSCs was induced by dexamethasone (DEX) stimulation. Dynamic expressions of Apod in MSCs undergoing osteogenesis for different time points were determined by qRT-PCR. Relative levels of osteogenesis-associated genes, including ALP, RUNX2, and Osterix, in DEX-induced MSCs overexpressing Apod or not were examined. Moreover, the protein level of RUNX2, ALP, and Osterix; ALP activity; and mineralization ability influenced by Apod in osteogenic MSCs were assessed. At last, the potential influences of Apod on the PI3K/Akt pathway were identified through detecting the expression levels of PI3K and Akt in MSCs by Western blot. RESULTS: Apod was time-dependently upregulated in MSCs undergoing osteogenesis. DEX induction downregulated ALP, RUNX2, and Osterix and attenuated ALP activity and mineralization ability in MSCs undergoing osteogenesis, which were partially reversed by overexpression of Apod. In addition, Apod overexpression upregulated the reduced levels of PI3K and Akt in DEX-induced MSCs. CONCLUSION: Apod alleviates glucocorticoid-induced osteogenesis suppression in MSCs via the PI3K/Akt pathway, thus protecting the progression of OP.

Iron-Chelating Agent Can Maintain Bone Homeostasis Disrupted by Iron Overload by Upregulating Wnt/Beta-Catenin Signaling.

BACKGROUND: The incidence of osteoporotic fractures is increasing. In this study, we explored the activities of Wnt/ß-catenin signaling in bone tissues with iron accumulation. METHODS: We established rat bipedal walking models (RBWM), and a portion of our RBWM rats were intraperitoneally injected with ferric ammonium citrate, normal saline, and deferoxamine. Bone mineral density was measured with a small animal in vivo imaging system. The protein levels of ferritin, TRAP-5B, RANKL, and OPG in serum were measured by the enzyme-linked immunosorbent assay (ELISA). Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to quantify the RNA and protein expression levels of certain regulators involved in Wnt/ß-catenin signaling in bone tissues. RESULTS: In the present study, we established a rat bipedal walking model containing 32 bipedal rats, which were randomly classified into four groups, termed as NS, FAC, FAC+NS, and FAC+DFO. Those three experimental groups with FAC injection had significantly lower bone mineral density (BMD) than the control group NS (P < 0.05). The disruption of bone homeostasis and downregulation of Wnt/ß-catenin signaling were also observed in the three groups with FAC injection. Moreover, after the injection of deferoxamine, those aberrations in samples with FAC injection seemed repaired as test results returning or getting close to normal ranges. CONCLUSION: The osteoporosis could be caused by iron overload, which reduced the bone mineral density by disrupting the homeostasis of bone formation and absorption and attenuating the Wnt/ß-catenin signaling in bone tissues. The deferoxamine had the potential to improve the bone health by reducing the accumulation of iron and increasing the bone mass, which might be a promising therapeutic solution for osteoporosis.

Clinical and molecular features of children with Beckwith-Wiedemann syndrome in China: a single-center retrospective cohort study.

BACKGROUND: Beckwith-Wiedemann syndrome (BWS) is a genetic overgrowth disorder with variable clinical features and cancer predisposition. In this study, we aim to characterize the clinical features and molecular defects of BWS patients in China. METHODS: Thirty-one patients with clinical suspicion of BWS were retrospectively recruited to the study from Shanghai Children's Hospital between January 2014 and December 2017. Clinical data, including demographics, clinical features, and molecular testing results were extracted and systematically analyzed. RESULTS: Twenty-one patients with a BWS score ≥ 4 (6, IQR 4, 7) were clinically diagnosed with BWS, and 10 children with a BWS score ≥ 2 and < 4 (2, IQR 2, 3) were clinically suspected BWS patients. The most common cardinal feature of clinically diagnosed patients was macroglossia (71.4%) followed by lateralized overgrowth (33.3%) and exomphalos (14.3%), and the major suggestive features were umbilical hernia and/or diastasis recti (65.0%) and ear creases or pits (61.9%). Among 10 clinically suspected BWS patients, macroglossia and lateralized overgrowth were observed in 3 (30%) and 2 (20%) patients, and umbilical hernia and/or diastasis recti occurred in 7 (70.0%) patients. Seven (33.3%) clinically diagnosed patients and 3 (30%) suspected patients were identified with loss of methylation at KCNQ1OT1:TSS differentially methylated region (DMR; IC2 LOM), 5 (23.8%) clinically diagnosed BWS patients were identified with gain of methylation at H19/IGF2:IG-DMR (IC1 GOM), and 1 (4.8%) clinically diagnosed BWS patients was identified with paternal uniparental isodisomy 11 (pUPD11). The phenotype-genotype correlation analysis showed no significant difference among patients with IC2 LOM, IC1 GOM, and pUPD11. CONCLUSIONS: The current study presents the first cohort study of BWS patients in mainland China. The clinical and molecular features of the patients are similar to those of other reported BWS patients in the Chinese population.

A Practical Study of Diagnostic Accuracy: Scoliosis Screenings of Middle School Students by a Trained Nurse With a Smartphone Versus a Spine Surgeon With a Scoliometer.

STUDY DESIGN: Cross-sectional. OBJECTIVE: This study aimed to assess the accuracy of smartphone-aided diagnosis of scoliosis by a trained nurse compared with scoliometer-based diagnosis by a spine surgeon. SUMMARY OF BACKGROUND DATA: Many assessments have been developed to estimate the reliability of smartphone-aided measurements in diagnosing scoliosis. However, clinical studies assessing the accuracy of smartphone-aided diagnosis with radiographs or scoliometers are scarce. METHODS: A total of 2702 grade 7 students (mean age 13.56 yrs, range 13-15) at 10 middle schools were first screened with a smartphone by a trained nurse from the orthopedics department. Approximately half a year later, most of the students underwent a chest x-ray examination as part of a compulsory medical examination. Students with suspicious findings in either the first screen or the chest x-ray were recommended to a scoliosis clinic for single-blind tests, such as a forward bending test (FBT) and an analysis of the angle of trunk rotation (ATR) with a scoliometer, performed by an experienced spine surgeon. Finally, the Cobb method was conducted with full-spine radiographs to serve as the gold standard. RESULTS: The agreement between the first screening by the nurse and the second test by the spine surgeon was low in cases with a Cobb angle <10° (κ = 0.128 [0.04-0.22], P = 0.035) and fair in cases with a Cobb angle >10° (κ = 0.349 [0.19-0.50], P < 0.001). The results of receiver operating characteristic (ROC) curve analysis also suggested that these two tests were similar in their ability to diagnose scoliosis. However, when the Cobb angle cutoff was adjusted to 15°, the latter had markedly better diagnostic ability than the former. Overall, the sensitivity of the smartphone screening was not acceptable for recognizing scoliosis. CONCLUSION: This study revealed that smartphone-aided screening for scoliosis is risky. LEVEL OF EVIDENCE: 3.

miR-181d-5p-FOXP1 feedback loop modulates the progression of osteosarcoma.

MicroRNAs (miRNAs) are playing more and more fundamental roles in the progress of human cancers. miR-181d-5p has not been fully elucidated in human cancers. In this study, we aimed to investigate the biological function and mechanism of miR-181d-5p in osteosarcoma (OS). At first, the expression conditions of miR-181d-5p were identified in OS tissues and cell lines. Downregulation of miR-181d-5p was identified to be a significant prognostic factor for patients with OS. Using the bioinformatics analysis, the putative target mRNA (FOXP1) of miR-181d-5p was found out. Similarly, the expression conditions and prognostic value of FOXP1 were identified in OS. To validate the tumor suppressive role of miR-181d-5p in OS, gain or loss of function assays were carried out in OS cell lines. The results indicated the anti-oncogenic function of miR-181d-5p in OS. Subsequently, the oncogenic function of FOXP1 in OS was identified by functional assays. Rescue assays manifested that the oncogenic function of FOXP1 can be partially reversed by miR-181d-5p. Combining with the result of luciferase reporter assay, we confirmed that miR-181d-5p can act as a tumor suppressor in OS via targeting FOXP1. Further mechanism experiments revealed that FOXP1 can suppressed the transcription activity of miR-181d-5p by acting as a transcription inhibitor. In conclusion, our study revealed that miR-181d-5p-FOXP1 feedback loop modulates cell proliferation and metastasis in osteosarcoma.

Glycyrrhizin Suppresses RANKL-Induced Osteoclastogenesis and Oxidative Stress Through Inhibiting NF-κB and MAPK and Activating AMPK/Nrf2.

The treatment for osteoporosis involves inhibiting bone resorption and osteoclastogenesis. Glycyrrhizin (GLY) is a triterpenoid saponin glycoside known to be as the most medically efficacious component of the licorice plant. It has strong anti-inflammatory, antioxidant, and antitumor properties. We investigated the effect of GLY on osteoclastogenesis, bone resorption, and intracellular oxidative stress and its molecular mechanisms. In vitro osteoclastogenesis assays were performed using bone marrow monocytes with and without glycyrrhizin. We also evaluated the effects of glycyrrhizin on the secretion of TNF-α, IL-1ß, and IL-6 in LPS-stimulated RAW 264.7 cells using ELISA. The effects of glycyrrhizin on the expression of osteoclast-related genes, such as Nfatc1, c-fos, Trap, and cathepsin K (CK), were investigated by RT-PCR. Intracellular reactive oxygen species (ROS) were detected in receptor activator of nuclear factor kappa-Β ligand (RANKL)-stimulated osteoclasts in the presence and absence of glycyrrhizin. During the inhibition of osteoclastogenesis by glycyrrhizin, phosphorylation of AMPK, Nrf2, NF-κB, and MAPK was analyzed using western blotting. Our results showed that glycyrrhizin significantly inhibited RANKL-induced osteoclastogenesis, downregulated the expression of NFATc1, c-fos, TRAP, CK, DC-STAMP, and OSCAR, and inhibited p65, p38, and JNK. Glycyrrhizin was found to significantly decrease the secretion of inflammatory cytokines (TNF-α, IL-1ß, and IL-6). Additionally, glycyrrhizin reduced the formation of ROS in osteoclasts by inducing AMPK phosphorylation and nuclear transfer of NRF2, resulting in an upregulation of antioxidant enzymes, such as HO-1, NQO-1, and GCLC. In summary, we found that glycyrrhizin inhibited RANKL-induced osteoclastogenesis. It was also indicated that glycyrrhizin could reduce oxidative stress by inhibiting the MAPK and NF-κB pathways and activating the AMPK/NRF2 signaling. Therefore, glycyrrhizin may be used as an effective therapeutic agent against osteoporosis and bone resorption.

[Experimental study of urinary center change in pons after conus medullaris injury in rats].

Objective: To observe the structural changes of urinary center and the expression of Bcl-2 after conus medullaris injury in rats brain so as to explore the possible influence factors of degeneration in brain. Methods: Thirty-six adult Sprague-Dawley rats were randomly divided into experimental group ( n=30) and control group ( n=6). In the experimental group, the conus medullaris injury model was established by cutting off the spinal nerve below L 4, and no treatment was done in the control group. The modeling operations in the experimental group were successful, and 2 rats died at 3 months and 5 months after modeling operation respectively, which may be caused by renal failure or urinary tract infection. In the experimental group, 6, 6, 6, 5, and 5 rats were killed at 1 day, 1 week, and 1, 3, 6 months after operation respectively, and 1 rat was killed at each time point in the control group. The dorsolateral tissue of the pontine tegmentum was harvested to perform HE staining and Bcl-2 immunohistochemical SP staining. Results: HE staining showed that there was no obvious difference between the experimental group and the control group at 1 day after operation, the neurons were densely packed, arranged neatly, and the nucleoli were clear; at 1 week, the space between the neurons in the experimental group were slightly widened; at 1 month, nucleus retraction in some neurons happened in the experimental group; at 3 and 6 months, the nuclei in the experimental group were more and more condensed, and even some cells disappeared. Bcl-2 immunohistochemical SP staining showed that the expression of Bcl-2 in the control group was weakly positive. The positive expression of Bcl-2 was found at 1 day after operation in the experimental group; the positive expression of Bcl-2 at 7 days after operation was significantly higher than that in the control group, and reached the peak; the positive expression of Bcl-2 decreased gradually at 1, 3, and 6 months after modeling operation, but it was still higher than that of the control group. Conclusion: The urinary center appears structure degeneration and necrocytosis after conus medullaris injury in rats brain. The elevated expression of Bcl-2 may be associated with brain tissue repair and function remodeling.

[Changes of endogenous Spastin expression after sciatic nerve injury in rats].

Objective: To investigate the expression change of endogenous Spastin after sciatic nerve injury in rats, and to discuss the role and significance in the peripheral nerve regeneration. Methods: Thirty-six adult male Sprague Dawley rats weighing 180-220 g were randomly divided into the experimental group ( n=30) and the control group ( n=6). Sciatic nerve compression damage model was established in the experimental group, and the sciatic nerve was only exposed in the control group. The L 4-6 spinal cord tissue was obtained to detect Spastin mRNA and protein levels by real-time fluorescence quantitative PCR and Western blot at 1, 3, 7, 14, and 28 days after operation in the experimental group ( n=6) and at 7 days in the control group. Meanwhile, the sciatic nerve at 5 mm distal to the injured site was obtained to observe the ultrastructure of the distal axon by transmission electron microscope (TEM). Results: The expression trends of Spastin gene and Spastin protein in L 4-6 spinal cord tissue of 2 groups were basically identical. In the experimental group, the expressions of Spastin gene and protein decreased at the beginning, and then increased; the expressions reduced to the minimum at 7 days after operation, and came back to the initial level at 28 days. The expression levels of Spastin mRNA and protein at 3, 7, and 14 days were significantly lower in the experimental group than the control group ( P<0.05), but no significant difference was noted between 2 groups at 1 and 28 days ( P>0.05). The expression levels of Spastin mRNA and protein at 3, 7, and 14 days were significantly lower than those at 1 and 28 days in the experimental group ( P<0.05), but no significant difference was noted between at 1 day and 28 days ( P>0.05). At 1, 3, and 7 days after operation, the myelin damage was observed by TEM; at 14 days, there were regenerating Schwann cells; at 28 days, a large number of myelinated nerve fibers were seen, which were closed to normal form. Conclusion: In the process of sciatic nerve regeneration after injury, a complex succession of changes take place in the expression of endogenous Spastin protein in rats, indicating that Spastin protein plays an important role in the process.

Doxorubicin-Loaded Micelles Based on Folic Acid Conjugated pH-Dependent Thermo-Sensitive Copolymer: In Vitro and In Vivo Evaluation.

In this paper, the doxorubicin (DOX)-loaded micelles were prepared based on a novel folic acid conjugated pH-dependent thermo-sensitive copolymer poly(D,L-lactic acid)-b-poly(N-isopropyl methacrylamide-co-N-isopropylmaelic acid-co-10-undecenoic acid) (PLA-PNNUA-FA) constructed to provide an active targeting drug delivery and triggered drug release system. The micelles were able to target tumors through the interaction between folic acid and its receptors which are overexpressed on the tumor cell membrane, and achieved pH-dependent thermo induced drug release in the intracellular mild acidic media such as endosomes and lysosomes after the micelles enter the cells. The results of cell assays and animal experiments showed that the micelles exhibited obvious tumor penetration efficiency in vivo, also improved DOX cell uptake and cytotoxicity in vitro. It was suggested that copolymer PLA-PNNUA-FA might be a potential targeted drug carrier to deliver chemotherapeutic drugs achieving better efficacy of chemotherapy.

Three monofunctional copolymers into one multifunctional Micelle: Part 1. Preparation and properties.

In the present work, we propose a new multifunctional micelle, co-self-assembled from different monofunctional copolymers, for tumor targeting and fluorescent and electron spin resonance (ESR) dual detection. Firstly, a poly(D,L-lactic acid)-b-poly(N-isopropyl methacrylamide-co-N-isopropylmaelic acid-co-10-undecenoic acid)-b-poly(N-acryloxysuccinimide) (PLA-PNNUA-PNAS) copolymer, with pH-dependent thermo-responsive properties, was synthesized. The copolymer was synthesized using reversible addition fragmentation chain transfer (RAFT) polymerization method, after which it was further used as a parent copolymer to combine with folic acid (FA), fluorescein isothiocyanate (FITC) and 4-amino-2,2,6,6-tetramethylpiperidin-1-oxyl (4-NH2-TEMPO), respectively, resulting into three new monofunctional copolymers. Finally, the multifunctional copolymer micelle was easily then fabricated, through co-self-assembly, using the monofunctional copolymers. The results from in vitro cell assays indicated that the proposed micelle was able to provide desired multifunctional properties, including tumor specific targeting and fluorescent and ESR dual detection. Additionally, the parent copolymer allowed conjugation with other ligands to prepare them for more functional copolymers attachment for future potential applications. More importantly, the multifunctional properties of the copolymer micelles could be rationally tailored, able for given purposes.

Preparation and characterization of thermosensitive and folate functionalized Pluronic micelles.

In this study, thermosensitive and folate functionalized poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide)-ploy(N-isopropylacrylamide-co-hydroxyethyl methacrylate) (FA-Pluronic-PNH) copolymer was synthesized. The structure and molecular weight of the copolymer were confirmed by 1H NMR, FT-IR and GPC, respectively. The lower critical solution temperature (LCST) of the copolymer was 39.8 degrees C. By employing doxorubicin (DOX) as a model drug, folate receptor-targeted DOX-loaded micelles were further formed on the copolymer. The blank and DOX-loaded micelles both exhibited nearly spherical shapes and their average diameters were 35 nm and 50 nm, respectively. The in vitro release behaviors of the DOX-loaded micelles were temperature-dependent and the release rate of DOX at 42 degrees C (above LCST) was faster than that at 37 degrees C (below LCST). Furthermore, the cytotoxicity assays of free DOX and DOX-loaded micelles on human cervical cancer cell lines HeLa and human lung cancer cell lines A549 demonstrated that folate increased the cellular uptake of the micelles within targeted cells that vastly over-expressed folate receptors.

Synthesis and characterization of multifunctional iron oxide nanoparticles.

In order to get high water solubility, monodisperse, superparamagnetic nanoparticles, poly (acrylic acid) was employed to modify Fe3O4 by a high-temperature solution-phase hydrolysis approach. Then, folic acid (FA) and fluorescein isothiocyanate were successively conjugated with prepared magnetic nanoparticles (MNPs). The functional MNPs were characterized by X-ray diffraction (XRD), dynamic light scattering (DLS), transmission electron microscope (TEM), inductively coupled plasma-atomic emission spectrometer (ICP-AES), and vibrating sample magnetometer (VSM), respectively. The toxicity of the materials was evaluated by selecting NIH/3T3 fibroblast cells and no toxic effect was observed. The fluorescent imaging and targeting property of the MNPs were also realized in vitro and in vivo experiments by confocal laser scanning microscopy (CLSM) and Kodak In-Vivo FX Professional Imaging System, respectively. The results indicated that the final products exhibited interesting magnetic, optical and targeting properties for further potential applications in biological and biomedical fields.

[Quantitative analysis of Mn, Cr in steel based on laser-induced breakdown spectroscopy].

Quantitative analysis of trace elements such as manganese and chromium in steel was performed employing laser-induced breakdown spectroscopy (LIBS) technique in the present paper. The experimental measurements indicate that the optimal delay, focal plane and detecting position from the sample surface are 2 micros, -3.5 mm and 1.5 mm,respectively. Mn I: 403.07 nm and Cr I : 427.48 nm were selected as the analytical lines and their contents in the target steel sample were analyzed with traditional quantitative analysis and internal standard methods. Comparison of the results with two kinds of quantitatively analytical methods show that the coefficients of determination gained by internal standard method are 0.998 and 0.979 which are much better than the results obtained by traditional quantitative analysis method. According to the established calibration curve by internal standard method the detection limits of manganese and chromium calculated are 0.005% and 0.040 6%, respectively.