Objective To explore the effects of partial body weight support treadmill training (PBWSTT) on motor function of lower extremities, walking ability and activities of daily living (ADL) in chronic hemiplegic patients after stroke. Methods28 patients with stable stroke (hemiplegic limbs Brunstrom s' scale≥Ⅲ) exceed 12 months after the onset were divided into PBWSTT group (n=14) and control group (n=14) randomly. Routine rehabilitation were used in the control group, and the PBWSTT group received PBWSTT in addition. They were assessed with Ashworth Spasticity Scale （ASS）, Functional Ambulation Category (FAC), Fugl-Meyer Assessment (FMA), and the Functional Independence Measurement (FIM) before and 8 weeks after the treatment. ResultsThe ASS,FAC, FMA and FIM scores were all improved after treatment in both groups (P<0.05). The scores of FMA, FAC and FIM in the PBWSTT group after treatment exceeded that of control group (P<0.05), but there was no difference in the ASS (P>0.05). ConclusionPBWSTT may improve the motor function of lower extremities, walking ability, and ADL in chronic hemiplegic patients after stroke.

This study was aimed to prepare solid dispersions of Acanthopanax leaves total flavonoids in order to im-prove its bioavailability. PEG4000, PEG6000, F68, PVPK30 were used as carrier materials in the preparation of four different types of solid dispersion to screen the best type of carrier material and evaluate the amount of carrier mate-rial and its influence on the drug dissolution. Rutin was used as reference substance. NaNO2-Al(NO3)3-NaOH was used as the color system, with a UV spectrophotometer measured absorbance at 500 nm. The dissolution characteris-tics of different proportions of solid dispersions were examined in vitro. The results showed that compared with raw material, the in vitro drug release rate with PVPK30 as carrier material in the obtained solid dispersion of the pro-portion of the raw material was significantly improved, and the cumulative release rate was also increased significant-ly. It was concluded that the solid dispersion prepared by solvent method significantly improved in vitro drug release in water.

BACKGROUND:Cartilage tissue engineering has been widely used to achieve cartilage regeneration in vitro and repair cartilage defects. Tissue-engineered cartilage mainly consists of chondrocytes, cartilage scaffold and in vitro environment. OBJECTIVE:To mimic the environment of articular cartilage development in vivo, in order to increase the bionic features of tissue-engineered cartilage scaffold and effectiveness of cartilage repair. METHODS: Knee joint chondrocytes were isolated from New Zealand white rabbits, 2 months old, and expanded in vitro. The chondrocytes at passage 2 were seeded onto a scaffold of articular cartilage extracelular matrix in the concentration of 1×106/L to prepare cel-scaffold composites. Cel-scaffold composites were cultivated in an Instron bioreactor with mechanical compression (1 Hz, 3 hours per day, 10% compression) as experimental group for 7, 14, 24, 28 days or cultured staticaly for 1 day as control group. RESULTS AND CONCLUSION:Morphological observations demonstrated that the thickness, elastic modulus and maximum load of the composite in the experimental group were significantly higher than those in the control group, which were positively related to time (P < 0.05). Histological staining showed the proliferation of chondrocytes, formation of cartilage lacuna and synthesis of proteoglycan in the experimental group through hematoxylin-eosin staining and safranin-O staining, which were increased gradualy with mechanical stimulation time. These results were consistent with the findings of proteoglycan kit. Real-time quantitative PCR revealed that mRNA expressions of colagen type I and colagen type II were significantly higher in the experimental group than the control group (P < 0.05). The experimental group showed the highest mRNA expression of colagen type I and colagen type II at 21 and 28 days of mechanical stimulation, respectively (P < 0.05). With the mechanical stimulation of bioreactor, the cel-scaffold composite can produce more extracelular matrix, such as colagen and proteoglycan, strengthen the mechanical properties to be more coincident with thein vivo environment of cartilage development, and increase the bionic features. With the progress of tissue engineering, the clinical bioregeneration of damaged cartilage wil be achieved.

BACKGROUND:Magnesium can be degraded voluntarily in vivo, so a second surgery is avoided. However, its aloys have not been widely used in the clinical orthopedics because there is a lack of accurate and reliable methods to assess its degradationin vivo.
OBJECTIVE:To explore the degradation of micro-arc-oxidized AZ31 magnesium aloy in the femoral condyle of rabbits based on micro-CT images and relative data.
METHODS:Forty micro-arc-oxidized AZ31 magnesium aloys were implanted into the right femoral condyle of 40 New Zealand rabbits. Then 10 right femoral condyles were removed at 5, 10, 15 and 20 weeks after surgery, respectively, to quantitatively analyze and evaluate the degradation of AZ31 magnesium aloys by micro-CT images and relative data.
RESULTS AND CONCLUSION:The surface of AZ31 aloys was corroded progressively with dark color and distorted appearance at 5-20 weeks post implantation. Micro-CT images showed that in the first 5 weeks, the degradation was inactive, and at the 10th week, it turned active; at the 15th week, the corrosion pits were obviously increased in number, and the corrosion area and corrosion speed were enlarged and fastened, respectively. Up to the 20th week, the aloy surfaces were ful of corrosion pits besides roughness and discontinuity. Relevant data analysis showed that the volume fraction of magnesium aloy was 98.6%, 97.1% and 86.4% at the 5th, 10th and 20th weeks after implantation, respectively, and it had a significant decrease from the 10th to 15th week and from the 15th to 20th week (P < 0.05). Within 15-20 weeks, the volume fraction of magnesium aloy was decreased by 6.5% that was the maximum volume reduction per unit cycle. With the progress of corrosion, the surface continuously became rough and vague, and its surface area was enlarged; the ratio of surface area to volume continuously increased, and there was a significant difference at 15 and 20 weeks (P < 0.05). Because of the increasing number of corrosion pits, the cross-sectional radius decreased, which was reflected by the trabecular thickness decreasing from 1.00 to 0.87 mm. From the view of the slope of curve, the trabecular thickness decreased most rapidly at 10-15 weeks. The mineral density of magnesium aloy continuously decreased from 649.302 to 356.445 mg/cm3 during the whole experiment period (P< 0.05). In addition, the micro-CT image density decreased from 679.710 to 644.947 mg/cm3, but there was no significant difference. To conclude, the degradation speed is peaked at 10-20 weeks after implantation, and the content of magnesium aloys decrease with degradation, but the magnesium density has no significant change.

Objective To investigate the therapeutic effects of haploidentical hematopoietic stem-cell transplantation (Haplo-PBSCT) for acute myeloid leukemia in first relapse after complete remission by standard induction chemotherapy. Methods Eighty-nine cases of AML in first relapse after complete remission by standard DA/Hi-Ara-C regimens induction chemotherapy were evaluated retrospectively. Fiftythree cases were grafted by haplo-PBSCT and 26 cases were treated with iDA/Mid-Ara-C or MA/ Mid- Ara-C agents. Results The second remission rate in haplo-PBSCT group and continuous chemotherapy group was 86. 7 % (46/53 cases) and 38. 1% (9/23 cases) respectively (P＜0. 01). Survival postprogression (SPP) at 36th month was 43. 4 % (23/53 cases) in haplo-PBSCT group and 11.5 % (3/26 cases) in continuous chemotherapy group (P ＜ 0. 05). Conclusion Haplo-PBSCT could significantly increase the second remission rate and prolong the survival time of patients with acute myeloid leukernia in first relapse after complete remission by standard induction chemotherapy.

Objective:To establish a mouse model of gastric cancer by inoculating MKN45 cells into mice with normal immune function utilizing microcarrier technology. Methods:A total of 60 male C57BL/6 mice were randomly divided into three groups, namely, 2D, con-trol, and 3D groups, according to the coculture system of MKN45 and microcarrier. The mouse models of gastric carcinoma were estab-lished by hypodermic injection. The time of tumorigenesis, rate of tumor formation, and pathological features were observed in each group. Results:In the 3D group, the time of tumor formation was short, whereas the rate of tumor formation was high (80%). No de-tectable tumor formations were observed in the 2D and control groups. HE and immunohistochemical staining of the transplantation tumor model showed evident characteristics of human gastric cancer. Conclusion:A human gastric cancer model in normal immune mice was successfully established. The onset and development mechanism of gastric cancer could be more effectively investigated in mice with normal immune function through this model. Moreover, a more valuable and new animal model for the research and devel-opment of anticancer drug was established.

OBJECTIVEInterventional treatment for childhood combined congenital heart disease (CHD) has developed very quickly and more new types of occluders have emerged in recent years. The aim of this study is to investigate the efficiency and safety of interventional treatment for combined CHD in children.

METHODSEight children with combined CHD (4 boys and 4 girls), aged 6.1+/-2.9 years, underwent simultaneous transcatheter therapy. Of the 8 children with CHD, 1 case had atrial septal defect (ASD), ventricular septal defect (VSD) and patent ductus arteriosus (PDA), 1 case had ASD, PDA and pulmonary stenosis (PS), 1 case had ASD and PDA, 1 case had patent foramen ovale (PFO) and PS, and 4 cases had ASD and PS. The methods of transcatheter intervention for these patients were as follows: in patients with ASD,VSD and PDA, the occlusion of VSD was performed first, followed by PDA and ASD occlusions; in patients with ASD, PDA and PS, the occlusion of percutaneous balloon pulmonary valvuloplasty (PBPV) was performed first, followed by PDA and ASD occlusions; in patients with PFO and PS, the occlusion of PBPV was performed first, and PFO occlusion followed; in patients with ASD and PS, the occlusion of PBPV was performed first, and ASD occlusion followed.

RESULTSThe intervention operation was successfully performed in all of the 8 patients. No serious adverse events occurred during the operation. No residual shunt was found and all the occlusion devices were in the suitable sites shown by transthoracic echocardiography (TTE) and X-ray right after the operation. In the 6 patients with PS, the systolic pressure across the pulmonary valve decreased from 75.3+/-15.6 mmHg (before operation) to 14.0+/-5.6 mmHg after operation (P<0.05).A 3.4+/-1.2 years follow-up demonstrated that no residual shunt occurred and gradients across valve or coarctation sites were within the limit of satisfactory results. No complications were observed during the follow-up.

CONCLUSIONSTranscatheter interventional therapy for childhood combined CHD can obtain satisfactory results by proper procedures.

Cardiac Catheterization ; adverse effects ; methods ; Child ; Child, Preschool ; Ductus Arteriosus, Patent ; surgery ; Female ; Follow-Up Studies ; Heart Defects, Congenital ; surgery ; Heart Septal Defects, Atrial ; surgery ; Heart Septal Defects, Ventricular ; surgery ; Humans ; Male ; Pulmonary Valve Stenosis ; surgery

Beijing ; COVID-19 ; Contact Tracing ; Humans ; Risk Factors ; SARS-CoV-2

With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versatile functions. Especially promising nanostructures are tetrahedral framework nucleic acids (tFNAs), first proposed by Turberfield with the use of a one-step annealing approach. Benefiting from their various merits, such as simple synthesis, high reproducibility, structural stability, cellular internalization, tissue permeability, and editable functionality, tFNAs have been widely applied in the biomedical field as three-dimensional DNA nanomaterials. Surprisingly, tFNAs exhibit positive effects on cellular biological behaviors and tissue regeneration, which may be used to treat inflammatory and degenerative diseases. According to their intended application and carrying capacity, tFNAs could carry functional nucleic acids or therapeutic molecules through extended sequences, sticky-end hybridization, intercalation, and encapsulation based on the Watson and Crick principle. Additionally, dynamic tFNAs also have potential applications in controlled and targeted therapies. This review summarized the latest progress in pure/modified/dynamic tFNAs and demonstrated their regenerative medicine applications. These applications include promoting the regeneration of the bone, cartilage, nerve, skin, vasculature, or muscle and treating diseases such as bone defects, neurological disorders, joint-related inflammatory diseases, periodontitis, and immune diseases.
Nucleic Acids/chemistry* ; Regenerative Medicine ; Consensus ; Reproducibility of Results ; DNA/chemistry*

COVID-19 ; China/epidemiology* ; Disease Outbreaks ; Humans ; SARS-CoV-2