[Formulation and process optimization of doxorubicin-loaded PLGA nanoparticles and its in vitro release].

Doxorubicin-loaded PLGA nanoparticles (DOX-PLGA NPs) was prepared by double emulsion (W/O/W) solvent evaporation method with the biodegradable materials-poly (lactic-co-glycolic acid) (PLGA) used as carrier materials. Single-factor test was used to investigate the influence of the type and ratio of the organic phase, the amount of surfactant, PLGA concentration, the ratio of external water phase and oil phase (W/O), the ratio of doxorubicin and PLGA, ultrasonic time and stirring time on the preparation of nanoparticles. The best formulation and preparation conditions were optimized by orthogonal test based on single-factor test, evaluation indicator as particle size and entrapment efficiency, and the results were analyzed by overall desirability. And the in vitro release behaviors of the nanoparticles were studied as well. The size distribution, zeta potential, morphology of DOX-PLGA NPs were characterized by laser light scattering and transmission electron microscopy; encapsulation efficiency and releasing behavior of DOX-PLGA NPs in vitro were investigated by ultraviolet spectrophotometry. The results show that the DOX-PLGA NPs are regularly spherical in shape with the mean size of (189.2 +/- 5.3) nm, and the zeta-potential of the NPs is about (-28.32 +/- 0.52) mV. Drug loading and encapsulation efficiency are estimated to be (73.16 +/- 0.43) % and (1.51 +/- 0.07) %, respectively. The cumulative percentage of the drug released is 90.34%, and the in vitro release behavior made up of initial burst release and sustained-release could be described by the bidirectional kinetic equation. The results indicate that hydrophilic small-molecule drugs could be successfully entrapped into PLGA-NPs. With optimization of the formulation and preparation conditions, we obtained uniform and stable DOX-PLGA NPs with sustained release character in vitro and pH-sensitive property, which could provide the experimental basis for the development of a new anti-tumor sustained-release formulation.

Multiple signaling pathways involved in stimulation of osteoblast differentiation by N-methyl-D-aspartate receptors activation in vitro.

AIM: Glutamate receptors are expressed in osteoblastic cells. The present study was undertaken to investigate the mechanisms underlying the stimulation of osteoblast differentiation by N-methyl-D-aspartate (NMDA) receptor activation in vitro. METHODS: Primary culture of osteoblasts was prepared from SD rats. Microarray was used to detect the changes of gene expression. The effect of NMDA receptor agonist or antagonist on individual gene was examined using RT-PCR. The activity of alkaloid phosphotase (ALP) was assessed using a commercial ALP staining kit. RESULTS: Microarray analyses revealed that 10 genes were up-regulated by NMDA (0.5 mmol/L) and down-regulated by MK801 (100 µmol/L), while 13 genes down-regulated by NMDA (0.5 mmol/L) and up-regulated by MK801 (100 µmol/L). Pretreatment of osteoblasts with the specific PKC inhibitor Calphostin C (0.05 µmol/L), the PKA inhibitor H-89 (20 nmol/L), or the PI3K inhibitor wortmannin (100 nmol/L) blocked the ALP activity increase caused by NMDA (0.5 mmol/L). Furthermore, NMDA (0.5 mmol/L) rapidly increased PI3K phosphorylation, which could be blocked by pretreatment of wortmannin (100 nmol/L). CONCLUSION: The results suggest that activation of NMDA receptors stimulates osteoblasts differentiation through PKA, PKC, and PI3K signaling pathways, which is a new role for glutamate in regulating bone remodeling.

Flow-injection chemiluminescence method for the determination of chloramphenicol based on luminol-sodium periodate order-transform second-chemiluminescence reaction.

A new chemiluminescence (CL) reaction was observed when chloramphenicol solution was injected into the mixture after the end of the reaction of alkaline luminol and sodium periodate or sodium periodate was injected into the reaction mixture of chloramphenicol and alkaline luminol. This reaction is described as an order-transform second-chemiluminescence (OTSCL) reaction. The OTSCL method combined with a flow-injection technique was applied to the determination of chloramphenicol. The optimum conditions for the order-transform second-chemiluminescence emission were investigated. A mechanism for OTSCL has been proposed on the basis of the chemiluminescence kinetic characteristics, the UV-visible spectra and the chemiluminescent spectra. Under optimal experimental conditions, the CL response is proportional to the concentration of chloramphenicol over the range 5.0 × 10(-7)-5.0 × 10(-5) mol/L with a correlation coefficient of 0.9969 and a detection limit of 6.0 × 10(-8) mol/L (3σ). The relative standard deviation (RSD) for 11 repeated determinations of 5.0 × 10(-6) mol/L chloramphenicol is 1.7%. The method has been applied to the determination of chloramphenicol in pharmaceutical samples with satisfactory results.

NMDA enhances stretching-induced differentiation of osteoblasts through the ERK1/2 signaling pathway.

Activation of the excitatory neurotransmitter N-methyl-d-aspartate (NMDA) and stretching both increase Ca(2+) influx in osteoblastic cells. We postulated that NMDA would enhance the osteoblastic cell's response to stretching. The goal of this study was to investigate, in the presence of the neurotransmitter NMDA, the effect of mechanical loading on osteoblast's stage of differentiation and the mitogen-activated protein kinase (MAPK) signaling pathway associated with it. Rat primary osteoblastic cells were subjected to cyclic, equibiaxial stretch for 48 h in the presence or absence of NMDA. Pretreatment with 0.5 mM NMDA significantly enhanced the stretching magnitude-dependent increase in osteogenesis markers. MK801, an antagonist of NMDA receptors, abolished those responses. To further study the mechanism of this response, osteoblastic cells were stretched for 5, 15, or 60 min in the absence of NMDA. Cyclic stretch induced a rapid increase in extracellular signal-regulated kinase ERK1/2 phosphorylation with the peak at 15 min, but no changes were noted in p38 and JNK pathway signaling. NMDA could enhance ERK1/2 phosphorylation stimulated by stretching. U0126, an inhibitor of ERK1/2, blocked the increase in osteogenesis markers. In conclusion, the current study demonstrates that there is a synergistic effect between mechanical stimulation and NMDA in osteoblasts. ERK1/2 signaling may be the common pathway in the increased response to stretching in the presence of NMDA in osteoblastic cells.

Comparative effectiveness research of iRoot BP plus and MTA used in the endodontic revascularization of dental pulp in treating the apical infection of young permanent teeth / 中国医学装备

Objective:To explore the clinical efficacies of root canal filling and repair material(iRoot BP plus)and trioxide condensate(MTA)of root canal repair material,which were used in endodontic revascularization of dental pulp,in treating the apical infection of young permanent teeth.Methods:A total of 40 young patients with apical infection of permanent teeth admitted to the dental department of hospital were selected,and they were divided into an observation group and a control group according to the random number table method,with 20 cases in each group.All patients adopted endodontic revascularization of dental pulp to conduct treatment.The observation group used iRoot BP plus to seal the upper end of the root canal,and the control group used MTA to seal the upper end of the root canal.The clinical efficacy,treatment cycle,frequency of visits,recovery time of chewing and recovery time of apical infection of the two groups of patients were compared.At the same time,the thickness of root canal wall and the root length,as well as the satisfaction of patients for treatment,of the two groups were compared.Results:After endodontic revascularization of dental pulp,the total effective rate of treatment in the observation group was 95%,which was significantly higher than 60%in the control group,and the difference was statistically significant(x2=8.326,P>0.05).Compared with the control group,the treatment cycle,frequency of visits,recovery time of chewing and recovery time of apical infection of the observation group were significantly shortened,and the differences were statistically significant(t=12.492,t=10.424,t=6.524,t=11.907,P<0.05),respectively.After treatment,the length of the root of dental crown and the thickness of root canal wall of the patients in the observation group were respectively longer and better than those in the control group,the differences were statistically significant(t=8.742,t=7.048,P<0.05).The four satisfaction scores of patients in the observation group,which included bite,tooth color,chewing ability and overall aesthetics,were respectively higher than those in the control group,and the differences were statistically significant(t=5.437,t=5.093,t=7.591,t=6.852,P<0.05).Conclusion:iRoot BP plus has more advantages than MTA when the endodontic revascularization of dental pulp is used to treat the apical infection of young permanent teeth,which can more effectively improve the clinical efficacy and treatment satisfaction of patients.

Treatment options for refractory/relapsed multiple myeloma: an updated evidence synthesis by network meta-analysis.

BACKGROUND: The refractory/relapsed multiple myeloma (RRMM) remains a big clinical challenge, due to its biological and clinical complexity. Leading hematologists have performed many randomized controlled trials (RCTs) worldwide, and their findings were summarized in a recently published network meta-analysis (NMA) but with certain limitations. MATERIALS AND METHODS: We performed an updated NMA of RCTs related to RRMM treatment, focusing on efficacy measures including the nonresponse rate (NRR), time to progression (TTP), progression-free survival (PFS), and overall survival (OS). The PubMed database was searched. We extended the literature search strategy of a previous NMA to June 30, 2017 and included additional primary RCTs. The surface under the cumulative ranking curve (SUCRA) was calculated to rank the regimens. A weighted-average method was used to rank the regimens by summarizing SUCRAs across different outcome measures. RESULTS: Finally, a total of 24 RCTs were included in this updated NMA. According to the result, the combination of daratumumab, lenalidomide, and dexamethasone showed better efficacy than other regimens in terms of NRR, TTP, and PFS (NRR: odds ratio [OR] =0.046, 95% credible interval [CrI] =[0.024, 0.085]; TTP: hazard ratio [HR] =0.14, 95% CrI =[0.092, 0.2]; PFS: HR =0.12, 95% CrI =[0.077, 0.18], compared with dexamethasone singlet). The combination of ixazomib, lenalidomide, and dexamethasone showed better efficacy than other regimens in terms of OS (HR =0.30, 95% CrI =[0.17, 0.54], compared with dexamethasone). The combination of daratumumab, lenalidomide, and dexamethasone ranked first in terms of overall efficacy (weighted average of SUCRAs =0.920). CONCLUSION: The combination of daratumumab, lenalidomide, and dexamethasone may currently be the most effective regimen in the population of RRMM patients. Triplet regimens containing daratumumab, ixazomib, carfilzomib, or elotumumab plus lenalidomide and dexamethasone can be recommended as first-line therapies for RRMM patients.

The Clinical Significance of O6-Methylguanine-DNA Methyltransferase Promoter Methylation Status in Adult Patients With Glioblastoma: A Meta-analysis.

BACKGROUND AND OBJECTIVE: Promoter status of O6-methylguanine-DNA methyltransferase (MGMT) has been widely established as a clinically relevant factor in glioblastoma (GBM) patients. However, in addition to varied therapy schedule, the prognosis of GBM patients is also affected by variations of age, race, primary or recurrent tumor. This study comprehensively investigated the association between MGMT promoter status and prognosis in overall GBM patients and in different GBM subtype including new diagnosed patients, recurrent patients and elderly patients. METHODS: A comprehensive search was performed using PubMed, EMBASE, Cochrane databases to identify literatures (published from January 1, 2005 to April 1, 2017) that evaluated the associations between MGMT promoter methylation and prognosis of GBM patients. RESULTS: Totally, 66 studies including 7,886 patients met the inclusion criteria. Overall GBM patients with a methylated status of MGMT receiving temozolomide (TMZ)-containing treatment had better overall survival (OS) and progression-free survival (PFS) [OS: hazard ratio (HR) = 0.46, 95% confidence interval (CI): 0.41-0.52, p < 0.001, Bon = 0.017; PFS: HR = 0.48, 95% CI 0.40-0.57, p < 0.001, Bon = 0.014], but no significant advantage on OS or PFS in GBM patients with TMZ-free treatment was observed (OS: HR = 0.97, 95% CI 0.91-1.03, p = 0.08, Bon = 1; PFS: HR = 0.76, 95% CI 0.57-1.02, p = 0.068, Bon = 0.748). These different impacts of MGMT status on OS were similar in newly diagnosed GBM patients, elderly GBM patients and recurrent GBM. Among patients receiving TMZ-free treatment, survival benefit in Asian patients was not observed anymore after Bonferroni correction (Asian OS: HR = 0.78, 95% CI 0.64-0.95, p = 0.02, Bon = 0.24, I2 = 0%; PFS: HR = 0.69, 95% CI 0.50-0.94, p = 0.02, Bon = 0.24). No benefit was observed in Caucasian receiving TMZ-free therapy regardless of Bonferroni adjustment. CONCLUSION: The meta-analysis highlights the universal predictive value of MGMT methylation in newly diagnosed GBM patients, elderly GBM patients and recurrent GBM patients. For elderly methylated GBM patients, TMZ alone therapy might be a more suitable option than radiotherapy alone therapy. Future clinical trials should be designed in order to optimize therapeutics in different GBM subpopulation.

Long-Term Efficacy of Maintenance Therapy for Multiple Myeloma: A Quantitative Synthesis of 22 Randomized Controlled Trials.

We aimed to quantitatively synthesize data from randomized controlled trials (RCTs) concerning maintenance for multiple myeloma (MM). We searched electronic literature databases and conference proceedings to identify relevant RCTs. We selected eligible RCTs using predefined selection criteria. We conducted meta-analysis comparing maintenance containing new agents and conventional maintenance, and subgroup analysis by transplantation status and mainstay agent as well. We performed trial sequential analysis (TSA) to determine adequacy of sample size for overall and subgroup meta-analyses. We performed network meta-analysis (NMA) to compare and rank included regimens. A total of 22 RCTs involving 9,968 MM patients and 15 regimens were included, the overall quality of which was adequate. Significant heterogeneity was detected for progression-free survival (PFS) but not overall survival (OS). Meta-analyses showed that maintenance containing new agents significantly improved PFS but not OS [PFS: Hazard Ratio (HR) = 0.59, 95% Confidence Interval (CI) = 0.54 to 0.64; OS: HR = 0.93, 95% CI = 0.87 to 1.00], compared with controls. Subgroup analyses revealed lenalidomide (Len)-based therapies better than thalidomide-based ones (HR = 0.50 and 0.66, respectively; P = 0.001). NMA revealed that most of the maintenance regimens containing new agents were significantly better than simple observation in terms of PFS but not OS. Len single agent was the most effective, considering PFS and OS both. We concluded that conventional maintenance has very limited effect. Maintenance containing new agents is highly effective in improving PFS, but has very limited effect on OS. Maintenance with Len may have the largest survival benefits. Emerging strategies may further change the landscape of maintenance of MM.

An analysis on inhibin A and activin A combined with uterine artery doppler in the prediction of preeclampsia / 预防医学

Objective To evaluate the predictive value of pre-eclampsia with the combination of inhibin A,activin A and uterine artery doppler.Methods The single pregnant pregnant women were divided into 9-12 week of pregnancy groups and 13-16 week of gestation group based on examination of gestational age.According to the outcome of further follow-up the women are divided into normal pregnancy (9-12 week pregnant or 13-16 week pregnant normal group) and the PE group (9-12 weeks pregnant or pregnant 13-16 PE group).Enzyme-linked immunosorbent assay (ELISA) was used to detect the concentration of inhibin A and activin A.Doppler ultrasound were used to examine UAPI.The results were converted to MoM values to calculate the combined detection specificity and sensitivity.Results The concentration of serum inhibin A and activin A and UAPI in 9-12 week pregnant PE group were significantly higher than that in 9-12 week normal pregnant (P ＜0.05).The concentration of serum inhibin A and activin A and UAPI in 13-16 week pregnant PE group were significantly higher than that in 13-16 week normal pregnant (P ＜0.05).When the maximum area under the curve of three indicator combined application (AUC =0.836) in 9-12 week pregnant,the specificity was 72％ and the sensitivity was 83％.When the maximum area under the curve of three indicators combined application (AUC =0.912) in 13-16 week pregnant,the specificity was 87％ and the sensitivity was 86％.Conclusion The combined application of peripheral blood inhibin A,activin A and UAPI could predict PE.The combined application of three indicator detection index provides a high degree of specificity,sensitivity and predictive value in 13-16 week pregnant.

PTH inhibition rate is useful in the detection of early-stage primary hyperparathyroidism.

OBJECTIVE: This study was to establish biochemical thresholds for the intravenous calcium suppression test in the early diagnosis of primary hyperparathyroidism (PHPT). DESIGN AND METHODS: One hundred and thirty-three patients were divided into three groups: Group 1: surgically proven hypercalcemic PHPT, Group 2 surgically proven mild PHPT, and Group 3: normocalcemia with elevated serum PTH levels. Intravenous calcium suppression tests were performed in Groups 2 and 3 as well as in 20 controls with normal serum calcium and PTH concentrations. RESULTS: The serum PTH inhibition rate (PTH-IR) was less pronounced in Group 2 compared with Group 3 (P<0.001) and the controls (P<0.001). Receiver operating characteristic curve analysis suggests that a serum calcium level higher than 2.43mmol/L and a PTH-IR less than 73% may differentiate Group 2 from normal controls. CONCLUSION: It is quite useful to combine serum calcium levels with the PTH-IR to identify patients at early stage of PHPT, even in the presence of vitamin D deficiency.