Combining Bone Collagen Material with hUC-MSCs for Applicationto Spina Bifida in a Rabbit Model.

Spina bifida is one of the neural tube defects, with a high incidence in human birth defects, which seriously affects the health and quality of life of patients. In the treatment of bone defects, the source of autologous bone is limited and will cause secondary damage to the patient. At the same time, since the bone tissue in animals needs to play a variety of biological functions, its complex structure cannot be replaced by a single material. The combination of mechanical materials and biological materials has become a common choice. Human umbilical cord mesenchymal stem cells (hUC-MSCs) have the advantages of easy access, rapid proliferation, low immunogenicity, and no ethical issues. It is often used in the clinical research of tissue regeneration and repair. Therefore, in this study, we established a spina bifida model using Japanese white rabbits. This model was used to screen the best regenerative repair products for congenital spina bifida, and to evaluate the safety of regenerative repair products. The results showed that the combination of hUC-MSCs with collagen material had better regeneration effect than collagen material alone, and had no negative impact on the health of animals. This study provides a new idea for the clinical treatment of spina bifida, and also helps to speed up the research progress of regenerative repair products.

Active bone material containing modified recombinant human bone morphogenetic protein-2 induces bone regeneration in rabbit spina bifida.

This study focuses on spina bifida, which is a high incidence among the current clinical manifestations of human birth defects. Because in the treatment of bone defects, the source of autologous bone is limited and it is easy to cause secondary injury to the patient. At the same time, since the bone tissue in animals needs to perform a variety of biological functions, its complex structure cannot be replaced by a single material. Therefore, in this study, we used Japanese white rabbits to establish an animal model similar to human congenital spina bifida. The established animal model is used to screen the best regenerative repair products for the treatment of congenital spondylolisthesis defects, and to evaluate the safety of regenerative repair products. The results show that bone morphogenetic protein (BMP)-2 combined with collagen material has a better regeneration effect than collagen material alone, and it did not negatively affect the health of animals. This study is not only suitable for the screening of large-scale biomaterials, accelerating the research progress of regenerative repair products, but also conducive to the research on the mechanism of regeneration and repair of various materials.

Repair of alveolar cleft bone defects in rabbits by active bone particles containing modified rhBMP-2.

Objective: A model of alveolar cleft phenotype was established in rabbits to evaluate the effect of active bone particles containing modified rhecombinant human BMP-2 on the repair of the alveolar cleft. Methods: 2-month-old Japanese white rabbits were selected and randomly divided into four groups: normal, control, material and BMP groups. Blood biochemical analysis, skull tomography (microfocus computerized tomography), and histological and immunohistochemical staining analysis of paraffin sections were performed 3  and 6 months after operation. Results: Both types of collagen particles showed good biocompatibility and promoted bone regeneration. The effect of active bone particles on bone repair and regeneration was better than that of bone collagen particles. Conclusions: Active bone particles containing modified rhecombinant human BMP-2 can be used for incisors regeneration.

L-Arginine and N-carbamoylglutamic acid supplementation enhance young rabbit growth and immunity by regulating intestinal microbial community.

OBJECTIVE: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. METHODS: Eighteen normal-grade male weanling Japanese White Rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (Day 37 to 65) and young stage (Day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. RESULTS: The addition of L-Arg and NCG were able to enhance the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake, daily weight gain. Both L-Arg and NCG were able to increase the concentration of IgA, IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height and V/C index, reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. CONCLUSION: L-Arg and NCG have promotional ability on the growth and immunity of weanling and young Japanese White Rabbits, as well as their effects on the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community.

Characterization of intestinal microflora in WHBE rabbit and Japanese white rabbit models of diarrhea-predominant irritable bowel syndrome / 中国实验动物学报

Objective To compare the differences in the intestinal microflora of WHBE rabbit and JW rabbit models of diarrhea-predominant irritable bowel syndrome(IBS). Methods 16 WHBE rabbits and 16 JW rabbits were randomly divided into normal control(NC)group and IBS model group, respectively(n=8). The diarrhea-predominant IBS model was established by wet-heat stress combined with intragastric gavage of senna decoction. The abdominal circumference index,water content of feces and colonic transit function were observed. After sacrifice,colon tissue samples were taken for histopathological examination and colon contents for intestinal flora diversity analysis. Results Compared with the NC group,the IBS model rabbits showed an increased abdominal circumference index and fecal water content,and a shortened colon transit time, but no obvious pathological changes were observed in the colon tissues. Meanwhile, the Shannon index and Chao1 index of IBS model rabbits were significantly decreased(P<0.05). According to the result of OTU classification analysis,Firmicutes and Bacteroidetes are the dominant bacteria in the intestinal microflora of rabbits. Compared with the NC group, the Firmicutes, Verrucomicrobia, Chloroflexi, Akkermansia, and Streptococcus in the WHBE rabbit IBS model group were significantly reduced(P < 0.05, P < 0.01), while Bacteroidetes and rc4-4 significantly increased(P < 0.05, P < 0.01). However, in the JW rabbit IBS model group, Eubacterium and Subdoligranulum were significantly increased(P< 0.05),while Lactobacillus,Coprobacter,Veillonella and Streptococcus were markedly decreased(P<0.05). Compared with the JW rabbit NC group,the abundance of Firmicutes,Odoribacter, Veillonella,Streptococcus,Oscillospira and Pseudoflavonifractor were significantly decreased(P<0.05, P<0.01), but Bacteroidetes,Verrucomicrobia,Eubacterium,Akkermansia and Coprobacter were significantly increased(P<0.05,P<0.01)in the WHBE rabbit NC group. Compared with the JW rabbit IBS model group, the abundance of rc4-4, Bacteroidetes,Coprobacter and Clostridium were significantly higher(P < 0.05, P < 0.01), while the Firmicutes, Dorea, Coprococcus and Subdoligranulum were significantly lower(P <0.05)in the WHBE rabbit IBS model group. Conclusions There is an intestinal microflora imbalance in rabbits with IBS, resulting in a decrease of microflora diversity. The changes of intestinal microflora in the WHBE rabbits and JW rabbits with IBS have their own characteristics, and have apparent differences.

Synchronous 12-lead electrocardiogram analysis of normal Japanese white rabbits / 中国比较医学杂志

Objective To observe the 12-lead ECG ( electrocardiogram ) characteristics of Japanese rabbits , and provide basic ECG data for cardiovascular disease research .Methods The 12-lead ECG and X-rays of 55 male Japanese rabbits were recorded in supine position after intraperitoneal injection of 20% urethane.Results ECG:① The 12-lead ECG characteristics of male Japanese rabbits were similar to humans .The rabbit heart rate was 265.5 ±36.8 beats/min, faster than that of humans .No arrhythmia was found in all the 55 rabbits.② The supine position average ECG axis was between 19 °to 250 °, varying a lot .③P wave:The shape of P wave was blunt round or a little bit sharp .P waves were all in accordance with the sinus P wave rules , which were more obvious in lead II , aVF and all chest leads .④ The PR interval was 0.063 ±0.007 s.⑤The QRS duration was 0.040 ±0.005 s.The main waves were mostly upward in leadsⅡ,Ⅲ, and aVF .The same as humans , the R/S ratios were increased by degrees in chest leads .⑥The ST segment was short, and was located in the equipotential line .⑦ The shapes of T wave were mostly round , partly had twin peaks .T waves were more obvious in leads Ⅱ,Ⅲ, aVR, and AVF and chest leads .⑧The QT interval was 0.142 ±0.015 s, and QTc was 0.306 ±0.034 s.In the X-rays, most heart shadows were in the center and right chest .Conclusions The normal values of 12-lead ECG characteristics of Japanese rabbits are obtained in this study , which are of certain application value in experimental studies of cardiovascular diseases .