BACKGROUND: Classic isolation method of bone marrow mesenchymal stem cells (BMSCs) is Percoll density gradient centrifugation. Blood cell component was removed. However, this method is complicated. Preparation density was needed when isolating dog bone marrow. Moreover, centrifugation was frequent, which had a great damage to cells. OBJECTIVE: To establish methods of the isolation, proliferation, culture and osteoinduction of canine BMSCs, and observe the in vitro proliferation and ability to osteoinduction differentiation. METHODS: 10 mL bone marrow was extracted from dog posterior superior iliac spine, heparin anticoagulation, diluted using Hanks juice, treated with 1.077 g/mL Ficoll solution 3 mL, and centrifuged at 2 000 r/min for 20 minutes. Karyocytes were absorbed to form white cloudlike layering interface, and then centrifuged twice using DMEM supplemented with fetal bovine serum, incubated at 12×10~4/cm~2 at 37 ℃ in a 5% CO_2 incubator. Following subculture, cells were incubated in DMEM containing dexamethasone, β-sodium phosphoglycerol and ascorbic acid 2-phosphate. Immunocytochemical staining and immunofluorescence staining were utilized to detect osteocalcin, osteopontin and type Ⅰ collagen expression in osteoblasts. Alkaline phosphatase staining and alizarin red staining were performed. RESULTS AND CONCLUSION: 1.077 g/mL Ficoll density gradient centrifugation was used to isolate karyocytes that were significant compared with Percoll solution. Obtained BMSCs had high purity, good growth and the mean doubling time was 24 hours. Following in vitro osteogenic incubation of dog BMSCs, osteocalcin, osteopontin and type Ⅰ collagen showed positive expression. Alkaline phosphatase staining demonstrated bluish-green cytoplasm. Alizarin red staining showed red nodes in extracellular matrix, and could differentiate into osteoblasts in vitro.

OBJECTIVETo find out the relativity among starch quantity, polysaccharides content and total alkaloid content of Dendrobium loddigesii.

METHODMicroscopy-counting process was applied to starch quantity statistics, sulfuric acid-anthrone colorimetry was used to assay polysaccharides content and bromocresol green colorimetry was used to assay alkaloid content. Pearson product moment correlation analysis, Kendall's rank correlation analysis and Spearman's concordance coefficient analysis were applied to study their relativity.

RESULT AND CONCLUSIONExtremely significant positive correlation was found between starch quantity and polysaccharides content, and significant negative correlation between alkaloid content and starch quantity was discovered, as well was between alkaloid content and polysaccharides content.

Alkaloids ; analysis ; Dendrobium ; chemistry ; Polysaccharides ; analysis ; Starch ; analysis

The dental education system and the training mode of dentists have a crucial influence on the quality of national dentists.Since 1960s,Australia has been constantly developing its dental education system,and now a mature and efficient mode of cultivating dentists has been formed,that is,bachelor degree of science being the prerequisite,four-year doctorate courses in dental medicine to produce general practice,two-year clinical experience and three-year doctorate courses in clinical dentistry to produce specialists.The dental courses in Australia are mainly composed of four parts:basic dentistry,life science,clinical dentistry model and research.The courses are characterized by a larger proportion for professional courses and an earlier time point for students to step in clinics,the co-culture of clinical and research skills,etc.The assessing method is case report,which means they put greater emphasis on intersection of clinics and lectures.We can learn a lot from their education system.The author compared and analyzed the dental education system of the two countries from background,course length and inclusion criteria,course design and etc,and came up with advice on dental education system of our own,hoping to provide Chinese dental educators with inspiration.

Objective To establish a rat model of Cryptococcus neoformans meningitis. Methods Sprague-Dawley rats were divided into four groups (group A to D). The load of Cryptococcus neoformans was inoculated by intracisternal injection to the animals in Group A (1×105 cfu), Group B (1×106 cfu), Group C (1×107 cfu), and 0.9％ NaCl solution to Group D. The rats were observed after inoculation for their clinical symptoms. On day 14 and day 21 after inoculation, cerebrospinal fluid was sampled and cultured for counting of bacterial colonies. The 28-day mortality of the animals was calculated. Results All the animals in group A (1×105 cfu) survived without any apparent clinical symptoms, and associated with decreasing bacteria load. The animals in group B (1×106 cfu) had mild symptoms associated with low mortality rate and slightly increased bacterial load. The animals in group C (1×107 cfu) showed a lot of symptoms and associated with high mortality rate and significantly increased bacteria load. All the animals in group D (0.9％ NaCl solution) survived with normal activity. No bacterial colony was cultured from the cerebrospinal fluid. Conclusions Intracisternal injection of 1×107 cfu Cryptococcus neoformans to rats could cause apparent clinical symptoms of meningitis. The 28-day mortality rate of such a rat model of Cryptococcus neoformans meningitis is greater than 80％. An ideal rat model of Cryptococcus neoformans meningitis is established successfully.

BACKGROUND:Indolepropionic acid has been shown to reduce diabetes-induced central nervous system inflammation.However,there is a lack of research on whether to inhibit microglia M1 polarization for the treatment of spinal cord injury. OBJECTIVE:To investigate the mechanism of indolepropionic acid inhibition of microglial cell M1 polarization for the treatment of spinal cord injury through cell and animal experiments. METHODS:(1)In vitro experiments:BV2 cell viability was assessed using the CCK-8 assay to determine optimal concentrations of indolepropionic acid.Subsequently,BV2 cells were categorized into control group,administration group(50 μmol/L indolepropionic acid),lipopolysaccharide group(100 ng/mL lipopolysaccharide),and treatment group(100 ng/mL lipopolysaccharide + 50 μmol/L indolepropionic acid).Nitric oxide content was quantified using the Griess method.Real-time quantitative PCR and western blot assay were employed to measure mRNA and protein levels of pro-inflammatory factors.Cell immunofluorescence staining was conducted to assess inducible nitric oxide synthase expression.The Seahorse assay was employed to assess glycolytic stress levels in BV2 cells.(2)In vivo experiments:30 SD rats were randomly divided into three groups:sham surgery group,spinal cord injury group,and indolepropionic acid group.Motor function recovery in rats after spinal cord injury was assessed using BBB scoring and the inclined plane test.Immunofluorescence staining of spinal cord tissue was conducted to evaluate the expression of inducible nitric oxide synthase in microglial cells.ELISA was employed to measure protein expression levels of the pro-inflammatory cytokines interleukin-1β and tumor necrosis factor-α in spinal cord tissue. RESULTS AND CONCLUSION:(1)In vitro experiments:Indolepropionic acid exhibited significant suppression of BV2 cell viability when its concentration exceeded 50 μmol/L.Indolepropionic acid achieved this by inhibiting the activation of the nuclear factor κB signaling pathway,thereby suppressing the mRNA and protein expression levels of pro-inflammatory cytokines(interleukin-1β and tumor necrosis factor-α),as well as the M1 polarization marker,inducible nitric oxide synthase,in BV2 cells.Additionally,indolepropionic acid notably reduced the glycolytic level in BV2 cells induced by lipopolysaccharides.(2)In vivo experiments:Following indolepropionic acid intervention in spinal cord injury rats,there was a noticeable increase in BBB scores and the inclined plane test angle.There was also a significant decrease in the number of M1-polarized microglial cells in spinal cord tissue,accompanied by a marked reduction in the protein expression levels of pro-inflammatory cytokines(interleukin-1β and tumor necrosis factor-α).(3)These results conclude that indolepropionic acid promotes functional recovery after spinal cord injury by improving the inflammatory microenvironment through inhibition of microglia M1 polarization.