pH and temperature sensitive biodegradable block copolymers are some macromolecules connected by biodegradable materials and pH sensitive monomers according to a certain sequence, or biodegradable polyesters polymerized themselves. On the basis of pertinent documents, the development of pH and temperature sensitive biodegradable block copolymers was introduced, involving their mechanism of action and potential application. PH and temperature sensitive biodegradable block copolymers could control the drug release rate freely, avoiding burst effect. Besides, the biocompatibility of these biodegradable materials is also excellent. So the use of pH and temperature sensitive biodegradable block copolymers as biodegradable drug delivery devices has attracted considerable interest in the intelligent drug delivery system.
Biocompatible Materials ; chemistry ; Drug Delivery Systems ; Hydrogen-Ion Concentration ; Lactates ; chemistry ; Lactic Acid ; chemistry ; Polyesters ; chemistry ; Polyethylene Glycols ; chemistry ; Polyglactin 910 ; chemistry ; Polyglycolic Acid ; chemistry ; Polymers ; chemistry ; Temperature

OBJECTIVETo investigate the effect and mechanism of Buyanghuanwu decoction on platelet activating factor expression in spinal cord tissue of model of acute upper cervical spinal cord injury in rats.

METHODSSixty SPF grade 3-month-old female Wistar rats were randomly divided into sham operation group, model group, methylprednisolone group and Buyanghuanwu decoction (Traditional Chinese Medicine group, TCM), with 15 rats in each group. The first day after the modeling, the methylprednisolone group were treated by injection of the tail vein for a total of 24 h, the first dose of 30 mg/kg, followed by a dose of 5.4 mg/kg·h, and 1 time per 4 h. The traditional Chinese medicine group was prepared with a medium dose of Buyanghuanwu decoction granules which were prepared into a solution containing 2 g/ml of granules, 3.5 g/kg per day gavage, was equivalent to 1 time the amount of adult consumption. The model group and the sham operation group were given equal volume of normal saline for 2 times a day for 2 weeks. The recovery of nerve function was evaluated by BBB classification at 1, 3, 7, 14 days after treatment. The expression of PAF in the segment of spinal cord injury was detected by double antibody sandwich (ELISA) method at 1, 7, and 14 d postoperatively.

RESULTSAt the first day after treatment, BBB score in model, TCM and methylprednisolone groups were lower than that of sham operation group(<0.01), but there was no difference among the three groups(>0.05). At 7, 14 days afer treatment, BBB score in TCM and methylprednisolone groups were higher than that of model group significantly(<0.01); but there were no significant difference between TCM group and methylprednisolone group(>0.05). PAF expression in TCM group and methylprednisolone group were lower than that of model group at 7, 14 day afer treatment significantly (<0.05); but there were no significant difference between TCM group and methylprednisolone group (>0.05).

CONCLUSIONSBuyanghuanwu decoction treatment after acute upper cervical spinal cord injury can significantly improve locomotor recovery by inhibiting the expression of PAF.

OBJECTIVETo explore the effect and underlying mechanism of decompression(DE)combined with Governor Vessel(GV)electro-acupuncture(EA) on rats with acute severe upper cervical spinal cord compression injury.

METHODSThirty SPF rats were randomly divided into 5 groups(control group A, B and experiment group C, D, E), 6 rats in each group. The model of acute severe upper cervical spinal cord compression injury were made by forcing a balloon catheter put in atlas pillow clearance. The group A was blank one, the group B put balloon catheter in atlas pillow clearance without forcing, and the group C, D, E sustained compressed for 48 h. The group C received electric acupuncture intervention, selecting the Baihui and Dazhui point, having the continuous wave and frequency of 2 Hz, with the treatment time of 15 min and continuous treatment for 14 d; the group D received methylprednisolone intervention, injected by caudal vein; the group E did not received any intervention again. The arterial blood and injured spinal cord tissue of all the rats were obtained after 14 days' treatment, and BBB score was used to evaluate the change of each group hind limbs motor function, the contents of platelet activating factor(PAF) in injured spinal cord tissue and blood serum were assess by ELISA method; the Caspase-9 expression for each group after 14 days' treatment was assess by Western blot method.

RESULTSBBB scores were(21.000±0.000) points at the 6 time points, that was, 1 h, 48 h after forcing in control group, 24 h, 3 d, 7 d, 14 d after treating in experiment group; the score of experimental groups (group C, D, E) were always lower than control groups(group A, B); compared with group E, group C and D were significantly higher(<0.05); and there was no significant difference between group C and group D(>0.05). The results of PAF by ELISA method to measure:the concentration of serum PAF, there was no statistical difference among group A, B, D, E (>0.05), group C was lower than the other groups (<0.05); the concentration of tissue PAF, there was no significant difference between group A and group B(>0.05), group D was significantly higher than that of group A, B, and C(<0.05), group E was the highest one than that of the other groups(<0.05). Western blot med tests showed that the Caspase-9 protein expression in group A and B was similar (>0.05), group C was higher than that of group A and B(<0.05), group D was higher than group A, B and C(<0.05), group E was the highest than that of group A, B, C and D (<0.05).

CONCLUSIONSDecompression and Governor Vessel electro-acupuncture on acute severe upper cervical spinal cord compression injury had a better effect compare with decompression and methylprednisolone or simple decompression only, its mechanism may be related to lower the PAF levels and downregulating Caspase-9 protein expression in spinal injury tissue.

AIM:To study the influence of lithium chloride (LiCl) on the neuronal differentiation of rat bone marrow mesenchymal stem cells (MSCs), and to explore whether autophagy was involved in this process .METHODS:MSCs were isolated and cultured in vitro.The cells were divided into LiCl group and control group .MSCs were treated withβ-mercaptoethanol as an inducer for triggering the cells to differentiate into neurons .The expression of neuronal markers-neuron specific enolase (NSE) and microtubule-associated protein-2 (MAP-2), and autophagic marker-microtubule-associ-ated protein 1 light chain 3 ( LC3) were measured by immunofluorescence method and Western blot .An autophagy activator rapamycin and autophagy inhibitor 3-methyladenine (3-MA) were applied to modulate the autophagy in the LiCl treated-cells.The protein expression of NSE and MAP-2 were determined by Western blot .RESULTS: After induction, the ex-pression of NSE and MAP-2 were increased .The percentage of NSE-and MAP-2-positive cells and the expression of NSE and MAP-2 in the LiCl group were greater than those in control group (P<0.05).After induction, the number of LC3-positive dots and the expression of LC3-Ⅱin LiCl group were greater than those in control group (P<0.05).The expres-sion of NSE and MAP-2 increased when the autophagy was modulated by rapamycin in LiCl treated -cells, and on the contra-ry, the expression of NSE and MAP-2 were inhibited as autophagy was modulated by 3-MA.CONCLUSION: Lithium chloride may promote the neuronal differentiation of rat bone marrow mesenchymal stem cells by modulating autophagy .

MECP2 duplication syndrome (MDS) is a rare pediatric disease and mainly manifests as delayed motor development, language loss or delay, recurrent infection, severe intellectual disability, epilepsy, autistic symptoms, and early infantile hypotonia. In this article, the three children with this disease were all boys. Cases 1 and 2 had delayed motor development, and language loss or delay as initial manifestations, and case 3 had recurrent infection as initial manifestation. Physical examination showed hypotonia and negative pathological signs in each case. Case 1 had tonic-clonic seizures and electroencephalography showed focal seizures, for which he was given oxcarbazepine, levetiracetam, and clonazepam as the antiepileptic treatment to control seizures. Case 3 experienced one absence seizure and three head-nodding seizures with normal electroencephalographic findings during these seizures, and therefore, he was not given antiepileptic treatment. In each case, recurrent infection was improved with the increase in age, but there were no significant improvements in language or intelligence. Array-based comparative genomic hybridization (aCGH) showed MECP2 duplication in X chromosome in each case, and so they were diagnosed with MDS. MDS should be considered for children with delayed development complicated by recurrent infection and epileptic seizures, and early aCGH helps with the diagnosis of this disease.
Child ; Comparative Genomic Hybridization ; Humans ; Infant ; Male ; Mental Retardation, X-Linked ; complications ; genetics ; Methyl-CpG-Binding Protein 2 ; genetics

Objective:To explore which configuration schemes of proximal humerus internal locking system (PHILOS) fixation with endosteal augmentation can provide the optimal biomechanical stability for treatment of osteoporotic proximal humeral fractures by means of finite element analysis.Methods:Based on the CT data of the humerus of an old female volunteer (78 years old, with a bone density T-value of -3.0), a three-dimensional finite element model of the humerus was established by digital medical software such as Mimics 19.0, Geomagic Studio 12, and Creo 2.0 ANSYS Workbench2019. Next, a model of unstable proximal humerus fracture was established and subjected respectively to 5 different fixations: simple PHILOS fixation (PHILOS group), PHILOS plus 6-cm fibula fixation with calcar screws (PHILOS-F-C-6 group), PHILOS plus 6-cm fibula fixation without calcar screws (PHILOS-F-6 group), PHILOS plus 9-cm fibula fixation with calcar screws (PHILOS-F-C-9), and PHILOS plus 9-cm fibula fixation without calcar screws (PHILOS-F-9 group). After a stress mode of shoulder joint abduction at 25° was simulated, a compressive load of 200N was applied to the 5 fixation models. The stress distribution and displacement of fracture ends in different fixation models were tested, and the biomechanical stability was compared among the 5 different internal fixations.Results:Under a shoulder joint abduction at 25° and a load of 200 N, the maximum stress and the displacement of the fracture ends in PHILOS-F-C-9 group (38.678 Mpa and 0.012 mm) decreased by 30.08% and 45.45%, respectively, compared with PHILOS-F-C-6 group (55.321 Mpa and 0.022 mm), and decreased by 12.48% and 15.38%, respectively, in PHILOS-F-9 group (77.012 Mpa and 0.033 mm) compared with PHILOS-F-6 group (88.106 Mpa and 0.039 mm). The maximum stress and the displacement of the fracture ends in PHILOS-F-C-6 group decreased by 37.21% and 43.59%, respectively, compared with PHILOS-F-6 group while decreased by 49.83% and 63.63% in PHILOS-F-C-9 group compared with PHILOS-F-9 group, respectively.Conclusion:For treatment of osteoporotic proximal humeral fractures with medial instability, PHILOS fixation with longer fibula endosteal augmentation plus insertion of calcar screws is a more appropriate choice which can reduce the stress of internal fixation and reduce the displacement of the fracture ends.

The objectives of the paper is to more accurate understand the use demands of wise classrooms for medical students, and provide scientific basis for wise classroom managers when formulating wise classroom environment optimization strategies. In the paper, the questionnaire survey method was used to investigate 23 indicators in 4 dimensions of hardware facilities, information technology, teaching methods and medical wise classroom features. And the data of 1 074 questionnaires were analyzed using KANO model analysis technology and satisfaction importance quadrant chart. Among the 23 demand indicators, there are 6 required attributes, 7 expected attributes, 9 charm attributes and 1 non-differential attribute. According to the theoretical importance ranking of the KANO model, wise classroom managers should first improve the quality of indicators related to necessary attributes, give priority to the quality of indicators related to expected attributes, and finally meet the requirements of indicators related to charm attributes. Relevant policies and construction suggestions for smart classrooms are put forward from the three levels of school top-level design, teachers and managers in the paper.

This study summarizes related studies on readiness for online teaching in China and globally and constructs an online teaching readiness scale for higher education teachers with reference to related studies on online teaching competency, blended teaching readiness, and influencing factors for online teaching. This scale includes five dimensions, i.e., belief, teaching readiness, technical readiness, online communication readiness, and institutional support. A questionnaire survey and statistical analyses were performed to investigate the rationality of the scale, and then the scale was modified. The results show that the indicators of the scale have a good degree of fitting, and this study provides a necessary standard for examining the online teaching readiness of higher education teachers and new ideas for online teaching in colleges and universities.

Objective:To investigate the changes of biomarkers in peritoneal dialysis patients' peritoneal drainage fluid and their relationship with the peritoneal small molecule solute transport rate (PSTR).Methods:Seventy newly-tubed peritoneal dialysis patients from the Peritoneal Dialysis Center of the First Teaching Hospital of Tianjin University of Traditional Chinese Medicine from September 29, 2014 to April 26, 2018 were selected. The levels of biomarkers plasminogen activator inhibitor-1 (PAI-1), matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) in the peritoneal dialysis priming fluid were measured at different time points and 4 h dialysate/blood muscle (D/P) creatinine values at 2 years of follow-up, and the correlation between biomarkers in the extracted peritoneal fluid and 4 h D/P creatinine was examined.Results:Longitudinal studies showed an increase in PAI-1 ( P<0.001) and VEGF ( P=0.04) with increasing duration of peritoneal dialysis. PSTR levels at baseline and after 2 years of follow-up were significantly correlated with PAI-1, MMP-2, and VEGF levels at baseline. PSTR at 2 years was also correlated with MMP-2 levels at 6 months and PAI-1 levels at baseline. Conclusions:The biomarkers PAI-1, MMP-2, and VEGF in peritoneal dialysis drainage fluid are positively correlated with PSTR in peritoneal dialysis patients during the 2-year period.

Objective To determine the efficacy ofantiepileptic drugs (AEDs) on prevention of epilepsy after craniocerebral injury. Methods Related articles searched from the databases such as PubMed, Ovid, Springer, VP and CNKI were collected and strictly evaluated; 21 articles were finally selected. Whether pretreatment with AEDs played its role in epilepsy appeared in the early/late stages was discussed with Meta-analysis; the influences of different craniocerebral injury types (resulting from trauma or surgery) on the efficacy of anti-epilepsy prophylaxis, and the mortality rate of the patients performed pretreatment were analyzed with Meta-analysis. Results Pretreatment withAEDs could significantly improve the results (OR=0.66, Z=4.31, P=0.000); pretreatment with AEDs obviously decreased the rate of epilepsy appeared in the early stage (OR=0.48, Z=3.980, P=0.000), but did not statistically decrease the rate of epilepsy appeared in the late stage (OR=1.05, Z=0.310, P=0.760);pretreatment with diphenylhydantoin (OR=0.53) was more effective on epilepsy appeared in the early stage than pretreatment with carbamazepine (OR=0.40). Pretreatment with AEDs was all-effective considering different craniocerebral injury types resulting from trauma (OR=0.48) and surgery (OR=0.69). No significant differences were noted on the mortality rate of patients performed pretreatment and without pretreatment (OR=0.82, Z=0.920, P=0.360). Conclusion The inception rate of epilepsy can be decreased remarkably after anti-epilepsy prophylaxis with AEDs in patients after craniocerebral injury,and diphenylhydantoin has a better effect for epilepsy appeared in the early stage. No reasonable differences between various kinds of AEDs on epilepsy appeared in the late stage are noted. Pretreatment with AEDs enjoys a good result in both post-traumatic brain injury and craniotomy. Pretreatment can not affect the mortality rate of the patients.