Chimeric CNS-targeting-peptide engineered exosomes for experimental autoimmune encephalomyelitis therapy.

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) that causes demyelination, neuronal damage and white matter loss, but there is still no known cure. Exosomes are 30-200 nm-sized double-layered membrane vesicles that can easily cross the blood-brain barrier (BBB). Exosomes from umbilical cord mesenchymal stem cells（UMSCs） have been found to treat experimental autoimmune encephalomyelitis (EAE) through the action of anti-inflammatory and immunomodulatory, but its clinical translation has been hampered by their inefficacious accumulation in CNS. Therefore, we developed a TAxI-exos, also known as a TAxI-peptide-chimeric UMSC-exos, for CNS-specific accumulation and curative effect in EAE. We used the EAE model in vivo as well as active T cell and BV-2 cell models in vitro to explore the efficacy and mechanisms. Exosomes from UMSCs with TAxI or DiR labels were given to EAE mice in one dosage (150 g) prior to the peak at day 15. The mice were sacrificed on day 30 so that spinal cords, spleens, and blood could be taken for analysis of demyelination, inflammation, microglia, T-cell subset proportions, and inflammatory cytokine expression. In vitro, PBMCs and splenocytes isolated from healthy C57BL/6 mice were activated and incubated with 0.15 mg/mL of UMSC-exos or TAxI-exos for immune mechanism investigations. Activated BV-2 cells were used to investigate the targeting and controlling polarization ability and mechanism of UMSC-exos and TAxI-exos. As expected, TAxI-exos exhibited significantly greater therapeutic action in EAE mice than UMSC-exos due to their improved targeting-ability. The medication reduced T-cell subset proportions and inflammation, reduced active-microglia proportions and promoted M1 to M2 microglial cell polarization through TNF pathway, upregulated IL-4, IL-10, TGF-ß, and IDO-1 expression, and downregulated IL-2, IL-6, IL-17A, IFN-γ, and TNF-α. The CNS-targeting properties of TAxI-exos and their capacity to inhibit degenerative processes in EAE mice have considerable potential therapeutic value for MS and other CNS illnesses.

Solid pseudopapillary neoplasm: Report of a case of primary ovarian origin and review of the literature.

Background: Solid pseudopapillary neoplasms (SPNs) are uncommon tumors of low malignancy with a generally favorable prognosis, mostly originating from the pancreas. To date, 12 cases of SPNs with a primary ovarian origin (SPN-Os) have been reported globally, and their detailed characteristics have not been fully elucidated. Case description: We reported the 13th SPN-O case, which occurred in a 52-year-old woman with an 18.5 cm left ovarian mass. Four imaging methods, including ultrasound, computed tomography, magnetic resonance imaging and positron emission tomography, were utilized before surgery. An elevated level of serum cancer antigen 125 was detected and a total hysterectomy plus bilateral salpingo-oophorectomy was performed. Microscopic examination revealed a typical solid pseudopapillary structure. The tumor cells were stained focally for pan-cytokeratin, synaptophysin, CD99 and CD10, while ß-catenin, vimentin and CD56 were diffusely expressed. The Ki-67 proliferation index was 3%, and immunohistochemical (IHC) staining for chromogranin-A, inhibin-a, and E-cadherin was negative. No evidence of recurrence or metastasis was observed by clinical and imaging data during a 5-month postoperative follow-up. Conclusion: This is a report of an unusual case of a primary ovarian SPN with an up-to-date review of SPN-Os. A minimum combination of imaging methods and IHC stains was proposed for SPN-Os, which may prove beneficial in clinical practice.

Optimal exercise parameters of tai chi for balance performance in older adults: A meta-analysis.

BACKGROUND: Tai chi is considered a safe and low-cost treatment for improving balance ability among an older population. However, there is no existing evidence on the optimal exercise parameters of tai chi for improving balance in older adults. OBJECTIVES: To investigate the optimal parameters of a tai chi intervention to improve balance performance of older adults. DESIGN: Systematic review and meta-analysis of randomized controlled trials (RCTs). SETTING: PubMed, Embase, Cochrane Library, Web of Science, Scopus, China National Knowledge Infrastructure, Wanfang, Chinese Science and Technology Periodical and China Biology Medicine were searched from inception until November 30, 2020. PARTICIPANTS: Adults aged 60 years and over. MEASUREMENTS: Two reviewers independently extracted the data and assessed the quality of the included studies according to the Physiotherapy Evidence Database (PEDro) scale. Subgroup analyses and meta-regressions were conducted to elucidate the impact of tai chi training programs on balance measures. RESULTS: Twenty-six eligible RCTs were included in the meta-analysis. Pooled results showed that tai chi has moderate effects for improving proactive balance (weighted mean standardized mean differences [SMDwm ] = 0.61, 95% CI 0.33-0.89) and static steady-state balance (SMDwm  = 0.62, 95% CI 0.30-0.95) and small effects for improving dynamic steady-state balance (SMDwm  = 0.38, 95% CI 0.03-0.73) and balance test batteries (SMDwm  = 0.47, 95% CI 0.13-0.81) in adults over 60 years of age. The practice frequency could predict the effects of tai chi on static steady-state balance, and the 24-form simplified Yang style tai chi (45-60 min/session, more than four sessions per week and at least 8 weeks) was the most optimal. CONCLUSIONS: Tai chi is effective at improving the balance ability of adults over 60 years of age. A medium duration and high frequency of 24-form tai chi may be the optimal program for improving balance, but this evidence should be recommended with caution due to limitations of the methodology and small sample sizes.

Transduction of mesenchymal stem cells with multidrug resistance gene provides protection for bone marrow toxicity after being transplanted into a nude mice model.

BACKGROUND: Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance (mdr1) gene is well-known for its ability to confering drug resistance. In this study, we meant to transplant the placenta mesenchymal stem cells (P-MSCs) moderated by mdr1 gene into a nude mice model radiated by γ-Co(60) and to explore the chemoprotection for bone marrow (BM) toxicity. METHODS: Human P-MSCs were isolated from trypsin-digested term placentas and then transduced by with reconstructed retroviral vector containing mdr1 gene and green fluorescent protein (GFP) reporter gene. The integration and expression of mdr1 gene was observed indirectedly by the expression of GFP. A nude mice model was constructed after irradiation with a sublethal dosage of γ-Co(60). These irradiated mice were transplanted with mdr1-MSCs through the caudal vein and then received paclitaxel (PAC) intraperitoneal chemotherapy. The Peripheral peripheral blood (PB) of the nude mice was collected, and the PB cells counts and values were determined using an automatic analyzer. RESULTS: After PAC treatment, mdr1-MSCs transplanted mice showed markedly improved survival upon compared to MSCs transplanted mice (85.7% vs. 57.1%). White blood cell (WBC) and red blood cell (RBC) counts as well as the hemoglobin (Hb) values were significantly increased in PAC treated mdr1-MSCs mice compared to PAC treated control mice when PAC chemotherapy had been finished (all P < 0.05), but the difference was not found in the plateltes (PLT) count (P > 0.05). CONCLUSION: Human P-MSCs moderated by mdr1 gene when transplanted into nude mice may provide chemoprotection for hematopoietic toxicity.

[Transfer and identification of multidrug resistance gene in mesenchymal stem cells derived from human placenta].

OBJECTIVE: To explore the feasibility and safety of mdr1 gene transferred into placenta derived mesenchymal stem cells (P-MSCs) by reconstructed retroviral vector. METHODS: Human P-MSCs were isolated and expanded by Percoll density gradient and then transduced repeatedly by reconstructed retroviral vector containing mdr1 gene. The transfection and expression of mdr1 gene was detected by reverse transcription-polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS). Meanwhile, the biological features of mdr1-MSCs were identified and analyzed. RESULTS: The expression of mdr1mRNA was found in transfected cells. The expression of P-glycoprotein (P-gp) encoded by mdr1 gene was (27.6 ± 5.1)% in the transfected P-MSCs cells versus (0.4 ± 0.1)% in the non-transfected P-MSCs cells (t = 14.291, P < 0.01). The percent of P-MSCs at quiescent phase (G0/G1 phase) was around 95.40% and it was in accord with the characterization of stem cells. The mdr1-MSCs exhibited typical ultrastructures of low-differentiated stem cells. Moreover, they still retained the potency of adipogenic and osteogenic differentiation in the presence of appropriate conditioned media. CONCLUSION: A stable expression of P-gp may be obtained by reconstructed retroviral-mediated transfection in vitro. And transfected MSCs retain the characteristics of stem cells.

[Thermal resources and maize temperature suitability in Northeast China under climate change].

This paper analyzed the spatiotemporal patterns of thermal resources and of temperature suitability of maize at its different growth stages in Northeast China, based on the 1951-2100 daily mean and minimum air temperature from RegCM3. In 1951-2100, the thermal resources in Northeast China had an obvious persistent increase, the first day of temperature > or = 10 degrees C continued to be advanced, and the north boundary line in the zone of the first date of temperature > or = 10 degrees C before April 25th moved eastward and northward. In 2071-2100, the first date in some areas of Liaoning Province would advance to March 26th, and the areas with active accumulated temperature > or = 10 degrees C more than 3000 degrees C x d, the length of growth season, and the areas suitable for late-maturing maize planting in Northeast China would increase persistently. In the region, the mean annual temperature in 2011-2100 would be 3.34 degrees C higher than that in 1981-2010. In 1951-2100, there was and would be an increasing temperature suitability of maize at its sowing-heading stage. In 1951-2040, the maize temperature suitability at heading-maturing stage and in whole growth season was and would be higher in Liaoning Province than in Heilongjiang Province; in 2041-2100, the maize temperature suitability at heading-maturing stage and in whole growth season would decrease gradually in Liaoning Province but increase gradually in east Jilin Province and Heilongjiang Province.

[Retention of biological features in human placental mesenchymal stem cells transfected by multidrug resistance gene].

OBJECTIVE: To transfer multidrug resistance gene (mdr1) into human placental mesenchymal stem cells (P-MSCs) by retroviral vector and assess the effects of mdr1 gene transduction upon biological features of P-MSCs. METHODS: Human P-MSCs were isolated from trypsin-digested term placentas and then transduced by reconstructed retroviral vector containing mdr1 gene and green fluorescent protein (GFP) reporter gene. Flow cytometric analysis was employed to determine the immunophenotypes of transfected P-MSCs. And the proliferation and cell cycle were detected by methyl thiazolyl tetrazolium and propidium iodide staining. Ultrastructures of transfected P-MSCs were observed and different induction conditions used to direct the cells to differentiate into adipocytes and osteoblasts. RESULTS: The transfected P-MSCs still expressed stem cell markers such as CD29, CD44 and CD73. The mean cumulative time of population doubling was 23.9 hours. The cellular cycle retained the proliferative characterization of stem cells. Ultrastructural features of transfected P-MSCs included increased surface microvilli, abundant mitochondria and slightly swollen rough endoplasmic reticulum. Furthermore these transfected cells demonstrated osteogenic and adipogenic differentiation potentials under appropriate conditions. CONCLUSION: The mdr1 gene transduction by retroviral vector in vitro has no significant effect upon biological characteristics of P-MSCs. It might provide experimental references for the application of P-MSCs in high-dose tumor chemotherapy.

Retroviral-mediated transfer and functional expression of multidrug resistance gene in human placenta mesenchymal stem cells.

BACKGROUND: Most of gynecologic malignancies are sensitive to chemotherapy. Myelosuppression is the main dose-related toxicity of many chemotherapeutic drugs. The human multidrug resistance (mdr1) gene is well known for its ability to confer drug resistance. This study aimed to explore the feasibility of expression and resistance of mdr1 gene transduction into human placenta mesenchymal stem cells (P-MSCs) by retrovirus vector. METHODS: Human P-MSCs were isolated from trypsin-digested term placentas, and their immunophenotypes and differentiation potential were evaluated. Human P-MSCs were transduced by reconstructed retroviral vector containing the mdr1 gene and green fluorescent protein (GFP) reporter gene. The integration and expression of the mdr1 gene were observed indirectly by the expression of GFP, and fluorescence-activated cell sorter was used to evaluate the functional activity of permeability glycoprotein (P-gp) encoded by the mdr1 gene. The stimulating test was made in vitro to show pleiotropic drug resistance of transfected cells. RESULTS: The isolated, cultured and expanded P-MSCs expressed stem cell markers such as CD29, CD44 and CD73, and showed osteogenic and adipogenic differentiation potentials under appropriate conditions. The expression of P-gp in the non-transfected P-MSCs cells was (0.4 +/- 0.1)%, but increased to (28.1 +/- 4.7)% after gene transfection (P < 0.01). And positive staining of P-gp located mainly at cell membrane and cytoplasm. Accumulation and extrusion assays showed that P-gp expressed by the transfected cells had pump-functional activity and could efflux daunomycin out of cells. The analysis of cell survival confirmed that transfected P-MSCs had a characteristic of multidrug resistance with a significant increase in the resistance to anticancer agents. CONCLUSIONS: Transfer and expression of human mdr1 gene mediated by retrovirus vector conferred P-MSCs drug resistance. It might provide a new alternative to chemoprotection strategies.

[Cytotoxicity of dendritic cells pulsed by CpG ODN on ovarian carcinoma cells: in vitro experiment with ovarian carcinoma cells].

OBJECTIVE: To investigate the effect of dendritic cells (DCs) pulsed by oligonucleotide containing "un-methylated cytimidine-phosphodiester bond-guanylic acid" motif (CpG ODN) on ovarian carcinoma cells. METHODS: Dendritic cells were isolated form the peripheral monocytes and co-incubated with synthesized CpG2006, CAI125, important epithelial ovarian cancer-associated antigen, or CpG ODN + CA125 for 72 h. Flow cytometry (FC) was used to detect the expression of CD(1alpha), CD(63), CD(86), and human leucocyte antigen-DR (HLA-DR) on the cell surface. ELISA was used to detect the IL-12 level in the supernatant. T cells were obtained from the DCs. The suspensions of different groups of pulsed DCs were co-incubated with T cells. Mixed lymphocyte reaction (MLR) was used to detect the proliferating activity of the T cells. Ovarian carcinoma cells of the line OVCAR-3 were added into the culture fluid of T cells with different effector-target ratios, and then unpulsed DCs, CpG ODN-pulsed DCs, CpG ODN + CA125-pulsed DCs, and CA125-pulsed DCs were added respectively. MTT colorimetry was performed to measure the A values of different wells so as to calculate the killing rate. RESULTS: (1) The expression levels of CD(63), CD(86), and HLA-DR on the membranes of the CpG ODN-pulsed DCs and CpG ODN + C125-pulsed DCs were significantly higher than those of the un-pulsed DCs (all P < 0.01), however, there were no significant differences in the expression of CD(1alpha) among different groups (all P > 0.05). (2) The IL-12 levels in the supernatants of the CpG ODN-pulsed DCs and CpG ODN + C125-pulsed DCs were significantly higher than those of the unpulsed and CA125-pulsed groups (all P < 0.01). (3) MLR showed that the T cell proliferation rates of the T cells sensitized by the CpG ODN-pulsed DCs and CpG ODN + C125-pulsed DCs were both higher than those of the T cells stimulated by the unpulsed and CA125-pulsed groups when the effector: target ratio was 10:1 (all P < 0.01). (4) The killing rates on OVCAR-3 cells of the CTLs sensitized by CpG ODN + CA125-pulsed DCs at the same effector: target ratios were all higher than those of the CTLs sensitized by the CpG ODN-pulsed DCs, CA125-pulsed DCs, and unpulsed DCs (all P < 0.01), the killing activity of the cytotoxic T lymphocytes (CTLs) sensitized by CpG ODN+CA125-pulsed DCs on the OVCAR-3 cells was shown even when the effector: target ratio was as low as 10:1, and then increased along with the increase of the effector: target ratio to the height of 64.9%. CONCLUSION: Capable of inducing immune cytotoxicity on ovarian carcinoma, DCs sensitized by CpG ODN + CA125 may have a great implication on clinical application.

The role of the cuff leak test in predicting the effects of corticosteroid treatment on postextubation stridor.

BACKGROUND: There is not enough evidence to determine the most appropriate treatment of postextubation stridor. Although the cuff leak test is a simple method to predict postextubation stridor, little is known about its use in monitoring the effects of steroid treatment for this complication. The aim of this study was to evaluate the effect of steroids on postextubation stridor based on the clinical response and the cuff leak test. METHODS: A cohort of 110 translaryngeal intubated patients in the medical intensive care unit (ICU) were enrolled. A cuff leak test was conducted before extubation. Patients developing postextubation stridor were intravenously given 5 mgs of dexamethasone every 8 hours for 3 days. The clinical response and cuff leak volume before and after steroid treatment were gathered for analysis. RESULTS: The incidence of postextubation stridor was 18.2% (20/110). Fifty-five percent of patients (11/20) with stridor needed reintubation. Overall, 80% of patients (16/20) with postextubation stridor improved with steroid treatment. The leak volume significantly increased after treatment (152.4 +/- 109.6 ml vs. 29.9 +/- 35.7 ml, p = 0.012); stridor did not recur in 64% of reintubated patients (7/11). A threshold leak volume of less than 88 ml predicted the occurrence of stridor (positive predictive value, 54.5%; negative predictive value, 90.9%). Postextubation stridor was associated with the female gender and lower leak volumes (p = 0.007 and 0.003, respectively). CONCLUSION: Corticosteroids improve postextubation stridor. The cuff leak test accurately predicts the absence of stridor and is a non-invasive method of monitoring for regression of laryngeal edema after steroid treatment. Steroid treatment should be considered for patients developing postextubation stridor.