ABSTRACT
Objective: To explore the potential mechanism of Yiqijianpi traditional Chinese medicine (TCM) compound treatment on gastric motility of diabetic gastroparesis (DGP) rats. Methods: Rats were treated with a single shot of STZ (tail vein injection) combined with high fat, high sugar, and irregular feeding methods for 4 weeks to induce DGP in these Rats. Then, they were randomized into the model group (normal saline 10 ml/kg), the mosapride group (mosapride 1.575 mg/kg), the high dose (5 g/kg), and the low dose TCM group (1.25 g/kg). In addition, normal rats were set as the control group (normal saline 10 ml/kg). Each group of rats was intragastrically administered once a day for 4 weeks according to the dose and treatment indicated above. The general conditions were recorded. The changes in weight, blood glucose, gastric emptying rate, and intestinal propulsion rate were monitored. ELISA was used to detect serum levels of gastrin (GAS), plasma motilin (MTL) and substance P (SP). Immunohistochemistry was used to detect the distribution and expression of tyrosine kinase (c-Kit) in the gastric antrum. The expression of stem cell factor (SCF) and tyrosine kinase (c-Kit) were detected by Western blotting. HE staining was used to observe pathological changes of the gastric antrum. Results: Compared with the control group, rats induced with GDP showed deteriorated disease progress, such as lower body weight (P<0.01) and higher blood glucose levels (P<0.01). Compared with the model group, rats that treated with different drugs showed improved parameters, such as increased body (P<0.05). In addition, lower blood glucose levels were detected in high/low-dose TCM group (P<0.05), with dramatic improvement in the high dose TCM group. The gastric emptying rate and small intestine propulsion rate of the model group were lower than those in the control group (P<0.01). The gastric emptying rate and small intestine propulsion rate in the high dose of TCM and the mosapride group were higher than those in the model group (P<0.05). Compared with the control group, the HE staining of the model group showed gastric glands of the gastric antrum were sparse and disorderly arranged with reduced numbers of blood vessels. Compared with the model group, those improved in each drug-administered group with the best-improved parameters detected in the high dose TCM group. The levels of serum GAS, plasma MTL and SP in the model group were lower than that in the control group (P<0.01). The levels of serum GAS and plasma MTL and SP in each drug-administered group were significantly higher than the model group (P<0.01). The expressions of SCF and c-Kit in gastric antrum of the model group were lower than those in the control group (P<0.01). The expression of SCF in gastric antrum of each drug-administered group was higher than that in the model group (P<0.05), among which high dose of TCM group changed most significantly (P<0.01). The expression of c-Kit in the mosapride group and the high dose of TCM group was higher than that in the model group (all P<0.05). Conclusion: Yiqijianpi compound can improve the gastric motility of DGP rats in a dose-dependent manner. It is likely that Yiqijianpi compound can promote the secretion of GAS, MTL, SP and other gastrointestinal hormones, and regulate the expression of SCF and c-Kit proteins in the gastric antrum.
ABSTRACT
Objective To study the contact performance of hip joint replacements with different material combinations typically used in clinic. Methods The finite element model of spherical conformal contact of hip joint replacements was developed to analyze the different contact mechanics performance of hip joint replacements with different material combinations by simulation test under a vertical constant load within one normal walking gait. The corresponding wear prediction was also evaluated. Results The contact mechanics performances of hip joint replacements with the material combination of metal-on-metal (MOM), metal-on-ceramic (MOC), ceramic-on-ceramic (COC), metal-on-polyethylene (MOP) and ceramic-on-polythene (COP) were analyzed. The results obtained from the simulations showed that contact stress was decreased in the order of COC＞MOC＞MOM＞COP＞MOP, while contact area was decreased in the order of MOP＞COP＞MOM＞MOC＞COC. Conclusions Hip joint replacement with the material combination of high elastic modulus and low Poisson’s ratio has smaller deformation, but could induce larger local stress, while flexible material polythene of low elastic modulus and high Poisson’s ratio might have smaller concentrated contact stress, but cause larger deformation and edge contact phenomenon on the acetabulum cup of hip joint replacements. In addition, hip joint replacements with MOC and MOM material combination may have lower contact bearing performance, which provides references for material choices of typical artificial hip joints in clinic.