BACKGROUND:Poly lactic acid as an excellent delivery has good biocompatibility.
OBJECTIVE:To prepare recombinant human bone morphogenetic protein-2 (rhBMP-2)/poly lactic acid (PLA) sustained release microspheres, and to study its physical and chemical properties.
METHODS:The rhBMP-2/PLA sustained release microspheres were prepared using w/o/w solvent evaporation method. Scanning electron microscopy, laser particle size, zeta potential, and swel ing properties were detected. ELISA kit was utilized for measurement of encapsulation efficiency, drug-loading rate and in vitro drug release rate.
RESULTS AND CONCLUSION:Under the scanning electron microscope, rhBMP-2/PLA sustained release microspheres were approximately circle with excellent dispersion. The uniform spheres were visible with a mean particle size of 839.6 nm. The zeta potential were (-32.93±3.74) mV. The swel ing coefficient was 1.157±0.059. The drug-loading rate and encapsulation efficiency of rhBMP-2/PLA sustained release microspheres were (88.943±2.878)%and (0.026±0.001)%respectively. The drug release rate at 1 day was about 10.199%, then the drug release was relatively constant, and til 19 days, the cumulative drug release rate was 54.643%. These findings indicate that the constructed rhBMP-2/PLA sustained release microspheres meet the requirement of the Chinese Pharmacopoeia (10th edition) that the encapsulation efficiency is not less than 80%and the microspheres have a good slow-release function in vitro.

Objective To investigate the feasibility of restoration of cartilage defect with silk fibrin/chitosan(SF-CS)biological scaffold compound by induced bone marrow mesenchymal stem cells (BMSCs)in the elderly rabbits.Methods BMSCs were extracted,cultured and induced to differentiate,then inoculated into SF-CS three-dimensional scaffold restoration.54 rabbits(aged 16-18months)were divided into scaffold restoration,single scaffold and control groups(n=18 per group).The right knee joint was used for building cartilage defect model and implanted by scaffolds.General observation,tissue staining and modified Wakitani histological scoring were performed at 4,8 and 12weeks after operation.Results SF-CS scaffold was structured by multiple interlinked pores.The average pore size was 151.72 μm.The porosity was(92.72±4.78)％.The imbibition rate was (141.10± 6.87)％.BMSCs was grown well and proliferated dynamically in SF-CS scaffold after induction.At 12 weeks,the cartilage defect was basically repaired,type Ⅱ collagen was positively expressed and the scaffold was almost assimilated in scaffold restoration group.In single scaffold group,the cartilage defect was repaired mainly by fiber tissue,type Ⅱ collagen was less expressed and the scaffold almost degraded while the cartilage defect was repaired badly in control group.The scaffold restoration group was superior to single scaffold and control groups(P＜0.05)in improving the Wakitani score.Conclusions The SF-CS scaffold as BMSCs carrier may restore cartilage defect in knee joint of the elderly rabbits.

BACKGROUND:Silk fibroin, chitosan, and nano hydroxyapatite are natural materials, and they al have good biological activity and physical or chemical properties. As tissue engineering materials, they have been already widely used in clinic or research work, but there are some defects in the application of these three kinds of materials. OBJECTIVE:To discuss the preparation and characteristics of silk fibroin/chitosan/nano hydroxyapatite complicated scaffolds which could be used in bone tissue engineering. METHODS:Silk fibroin, chitosan, and nano hydroxyapatite were separately prepared into 2%solution, and then mixed at the ratio of 1:1:0.5, 1:1:1, 1:1:1.5 respectively. The three-dimensional complicated scaffolds were prepared by those mixed liquids through repeated freeze drying and chemical crosslinking technology. Scanning electron microscope was used to detect the pore size of the scaffolds. Porosity, water absorption rate, and hot-water loss rate were determined. Mechanical tester was used to measure the tensile and compressive modulus of dried three-dimensional scaffolds. RESULTS AND CONCLUSION:The silk fibroin/chitosan/nano hydroxyapatite complicated scaffold in the dry state had no special smel , appeared to be a stabilized solid cylinder, and exhibited clear resiliency and flexibility with a touch. With the increased content of nano hydroxyapatite, the porosity, water absorption rate and average pore size of the scaffolds appeared to be decreased, while the hot-water loss rate and compressive strength were increased. The scaffold prepared at 1:1:1 was better for bone tissue engineering, and the average pore size, water absorption rate and hot-water loss rate were 85.67 μm, (135.65±4.56)%and (22.84±1.06)%, respectively, closer to the needs of the bone tissue engineering. Uniform pores were found within the scaffold at 1:1:1, showing the network structure, developed transport among pores, and the network structure was approximately 10μm.

Proline-rich cell wall proteins are widely spread in plants and are believed to function by modeling the architecture of the cell wall surrounding specific cell types. Five genes encoding proline-rich proteins were isolated from cotton cDNA libraries. The most common characteristic of these proteins is the abundant proline residues that occur in repeating motifs of at least two consecutive Pros. Based on amino acid composition, repetitive motifs and domain organization, the five members can be divided into two subgroups: one group similar to common PRPs including GhPRP3, GhPRP6, GhPRP5 and GhPRP4 was composed of two domains, an N-terminal hydrophobic domain (or signal peptide) followed by a proline-rich domain containing different proline-rich repetitive motifs; the other group different from common PRPs including GhPRPL lies in it contains an N-terminal hydrophilic domain, eight repetitive copies of pentapeptide (similar to PPKKE) lies in the C-terminal domain. Expression studies of the six GhPRPs have been carried out by quantitative realtime RT-PCR. The results showed that GhPRP3 and GhPRP5 were preferentially expressed in 10 dpa fiber, little transcripts was detected in other tissues examined. GhPRPL highly expressed in cotyledons, whereas smaller or negligible amounts of its transcripts were detected in other tissues. The remaining two genes, GhPRP4 and GhPRP6, were expressed in all the tissues analysed, but their transcript level is different. GhPRP4 mRNA is most abundant in hypocotyls, and then in anther, while GhPRP6 expressed highly in fiber, and then in 10 dpa ovule. Furthermore, the results showed that the fiber-specific GhPRP3 and GhPRP5 were also developmentally regulated, suggesting that the genes may play important roles during cotton fiber development.

BACKGROUND:Silk fibroin/chitosan/nano hydroxyapatite (SF/CS/nHA) composite scaffold constructed in preliminary experiments has good physical and chemical properties.
OBJECTIVE:To study the capacity and mechanism of SF/CS/nHA composite scaffold for repair of rabbit radial bone defects.
METHODS:Thirty-six New Zealand white rabbits were selected to make animal models of right radial bone defects, and then randomly divided into SF/CS/nHA group, SF/CS group and blank control group. Blank control group had no treatment after modeling. X-ray radiography, gross observation and histopathological observation were performed at 4, 8, 12, 16 weeks postoperatively.
RESULTS AND CONCLUSION:Sixteen weeks after surgery, bone defects in the SF/CS/nHA group were completed replaced by normal bone tissue on X-ray images, and the bone marrow cavity showed complete recanalization with new bone formation;hematoxylin-eosin staining showed bone trabecula and many fusiform bone cells. In the SF/CS group, the bone mineral density in the defect area was slightly lower than that of the normal bone tissues, the bone marrow cavity was partly rehabilitated, and many chondrocytes were seen around bone cells that arranged irregularly with no bone trabecula or bone lamel a. In the blank control group, the images of bone calcification were consistent with normal bone tissues, and a closed bone ununion was formed at each end;hematoxylin-eosin staining showed that the blank control group was fil ed by fibrous connective tissue and a smal amount of bone-like tissues. SF/CS/nHA composite scaffold is better for repair of rabbit radial bone defects.

Objective To study the inlfuence of the allicin on abnormal crypt focus(ACF). in Wister rat model. Methods 60 Wister rats were subcutaneous injected by dimethylhydrazine (DMH), according to 20 mg/kg weight, once a week, feeding 18 weeks continuously. All of the rats were randomly divided into allicin group and non-allicin group, each group was divided into three groups evenly, and put to death at 8, 16 and 24 weeks after medication separately. Large intestines were observed after dyeing. Results Large intestines were divided into ten equally, and all pieces were observed. ACF were almostly distributed in the middle and distal of the large intestines, about in 50%-80%.The basic situation of non-allicin group was as follows:ACF at 8 weeks was 63.97±1.22 on average per each, 16 weeks was 83.97±1.13, 24 weeks was 69.33±2.01. The basic situation of allicin group:ACF at 8 weeks was 9.4±1.12 on average per each , 16 weeks was 7.17±1.33, 24 weeks was 4.97±1.23.The occurrence of ACF in non-allicin group was higher than allicin group, the differences of incidence rate and number of ACF between two groups was significant (χ2=15.88,P<0.01).Conclusion Allicin can significantly reduce the number of ACF in Wister rats, lower the incidence of colorectal cancer, has prevention effect.

Objective To provide the basis for clinical diagnosis and treatments of colorectal cancer by studying the clinical characteristics and incidence tendency of colorectal cancer in recent 12 years in Kunming. Methods The data of 1628 colorectal cancer patients from 2001 to 2012 in the First Affiliated Hospital of Kunming Medical University were collected. The clinic pathological data of all patients was divided into 2001-2006 (Agroup) and 2007-2012 (B group) two consecutive time periods for statistical analysis according to its time of onset. Results The incidence of colorectal cancer in the city rose from 49.2%to 56.0%, and the incidence of colorectal cancer in rural areas decreased from 50.8%to 44%( <0.05) .The location ratio of colorectal cancer in the rectum decreased from 74.8%to 73.9%, in the left half colon ratio increased from 14.8%to 19%, while the right colon ratio decreased from 10.4% to 7.1% ( < 0.05) . The change in the three parts had statistically significant difference between two consecutive time periods. The percentage of colorectal cancer patients in Dukes A stage rose from 13.4% to 18.8%, while the percentage of patients in Dukes D stage decreased from 22.3% to 14.5% ( <0.01) . Conclusions The incidence of colorectal cancer in Kunming gradually increases.The morbidity in the city is significantly higher than that in the country. The ratio of left half colon cancer is rising, but the ratio of rectal cancer and right half colon cancer is falling. The early diagnosis rate of colorectal cancer is on the rise.

【Objective】 To establish preliminary diagnostic criteria of spleen-stomach damp-heat syndrome (SDS) in chronic superficial gastritis (CSG) by disease-syndrome combined differentiation method and modern epidemiological method. 【Methods】 A clinical questionnaire of SDS in CSG was drafted out based on literatures study and experts' survey. Questionnaire investigation was performed in 146 cases of CSG, which consisted of 81 SDS cases and 65 nonSDS cases. Mter the investigation, discriminant analysis was adopted to set up the discriminant functional equations and to perform frequency analysis. According to the results, the diagnostic criteria and the simplified diagnostic criteria of SDS in CSG were established. 【Results】 The preliminary diagnostic criteria of SDS in CSG were as follows: (1) the major symptoms were characterized as yellow and greasy tongue fur, fullness or distension or pain in the stomach, loose stool and poor appetite; (2) the secondary symptoms were characterized as bitter taste and sticky mouth, chest depression, thirst but unwilling to drink, fatigue and nausea; (3) diagnosis could be confirmed by the existence of yellow and greasy tongue fur accompanied by either 2 of the other major symptoms, or by either 1 of the other major and 2 of the secondary symptoms, or by more than 3 of the secondary symptoms. The simplified diagnostic criteria were characterized the co-existence of yellow and greasy tongue fur and fullness or distension or pain in the stomach. 【Conclusion】 The preliminary diagnostic criteria of SDS in CSG are scientific, objective and practicable to some extent.

Objective:To determine whether the neutrophil-lymphocyte-ratio (NLR) a inflammatory factor can predict tumor response to neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer.Methods:Between 2014 and 2019, 205 locally advanced rectal cancer patients underwent CRT before curative surgery. After propensity score matching, 148 patients (74 matched pairs) were enrolled in this study. The hematological parameters were collected and their relationship with tumor response was investigated.Results:After propensity score matching, NLR before CRT in good response group were significantly lower than that in poor response group(2.2±1.0 vs. 2.4±1.2, Z=-2.465, P<0.05), while there was no significant difference in all hematological characteristics between two groups after CRT. The cutoff values of pre-CRT NLR was 3.88 after receiver operating characteristic analysis(AUC=0.618, 95% CI: 0.528-0.708). Multivariate analysis model indicated that pre-CRT NLR≥3.88 was the predictor of poor tumor response ( OR=5.826, 95% CI: 1.299-26.132, P<0.05). Conclusion:The increased NLR before CRT can be regarded as a hematological factor for poor tumor response in locally advanced rectal cancer.

Objective: To explore the influence of personalized normative feedback interventions on precaution of adolescents’ Internet addiction，and to provide a new perspective for intervention in youth health online. Methods: A total of 170 students from the second grade in a middle school and a high school of Fuzhou Province were randomly selected between April and May in 2016. By using the pretest post-test control group design, 90 adolescents in experimental group received personalized normative feedback interventions, while the 80 adolescents in control group were tested without interventions. Results: At 1-month after intervention, students in the intervention group showed positive results relative to those in the control group on variables associated with online behavior, including the online time of students in experimental group and the index of their internet addiction have significantly reduced(t=2.79 and 3.09, P<0.01). Simultaneously, the estimate of the online time towards the experimental group students has decreased(t=3.75 and 3.74, P<0.01), the estimate of the proportion of study uses has decreased(t=-2.56, P<0.05). Conclusion The personalized normative feedback interventions, to some extent, has some precautions on the adolescents’ behaviors of internet addiction.