Objective To explore the solid gastric emptying characteristics of awake gastroparesis Beagle. Methods A Beagle model of gastroparesis was established by truncal vagotomy combined injection glucagon. Solid gastric emptying of the Beagle under normal and gastroparesis were evaluated with ultrasound imaging,and compared with the results of radionuclide SPECT scintigraphy. Results The solid gastric emptying process of the Beagle was in accordance with modified power exponential models: Y =1-(1-e-kt)β, half time of the gastric emptying of gastroparesis Beagle was obviously longer than normal, there was a significant difference between the two situation ( P ＜ 0.05). Conclusions The solid gastric emptying characteristics of the gastroparesis Beagle has a stable mathematical expression.

Objective To investigate the relationship between cerebral white matter fractional anisotropy(FA)and metabolite con-centrations measured by 1 H magnetic resonance spectroscopy(1 H-MRS)in healthy adults.Methods Diffusion tensor imaging(DTI) and 1 H-MRS were acquired from thirty-one healthy adults at 3.0 T MR system.The concentrations of N-acetylaspartate(NAA), choline(Cho),creatine(Cr),the ratios of NAA/Cr and FA values of DTI were measured in 353 voxels,covering the bilateral medium corona radiata.According to the age,all voxels were divided into two groups:the senior group (mean age=29 years),and the senior group(mean age=5 6 years).The correlations between FA values and age were analyzed using Pearson’s correlation coefficients.The correlations between FA values and metabolite concentrations were estimated using partial correlations test controlling for the age re-lated bias.Results Pearson’s correlation analysis revealed a negative correlation between FA values and age in 353 voxels(r=-0.146,P<0.05),senior group(r=-0.204,P<0.05)and senior group(r=-0.162,P<0.05).Only the correlation between NAA and FA values were significant(r=0.339,P<0.05;r=0.213,P<0.05;r=0.430,P<0.05).There were positive relation-ships between FA values and NAA/Cr among 353 voxels (r=0.166,P<0.05)and senior group(r=0.305,P<0.05).Conclusion There are correlations between cerebral white matter FA values and metabolite concentrations measured by 1 H-MRS .Combining 1 H-MRS with DTI can reveal the relationship between microscopic white matter integrity and metabolic characteristics of the white matter.

We observed the effect of vibration parameters on lumbar spine under different vibration conditions using finite element analysis method in our laboratory. In this study, the CT-images of L1-L5 segments were obtained. All images were used to develop 3D geometrical model using the Mimics10. 01 (Materialise, Belgium). Then it was modified using Geomagic Studio12. 0 (Raindrop Geomagic Inc. USA). Finite element (FE) mesh model was generated by Hypermesh11. 0 (Altair Engineering, Inc. USA) and Abaqus. Abaqus was used to calculate the stress distribution of L1-L5 under different vibration conditions. It was found that in a vibration cycle, tensile stress was occurred on lumbar vertebra mainly. Stress distributed evenly and stress concentration occurred on the left rear side of the upper endplate. The stress had no obvious changes under different frequencies, but the stress was higher when amplitude was greater. In conclusion, frequency and amplitude parameters have little effect on the stress distribution in vertebra. The stress magnitude is positively correlated with the amplitude.
Biomechanical Phenomena ; Finite Element Analysis ; Humans ; Lumbar Vertebrae ; physiology ; Vibration

BACKGROUND:J2 takes functional domain (MHC CD4-D1/) of complex conjugate of CD4 molecule and MHC class II molecule as a target, and is a smal molecule compound obtained by computer screening from a chemical data containing hundreds of thousands of organic compounds. In the previous study, J2 was used in mouse models of skin transplantation and keratoplasty by oral and intraperitoneal injection. Results verified that J2 could prolong the survival time of grafts, and suppress occurrence of rejection. To better play the role of a drug targeting and to reduce systemic toxicity, J2 wil be further utilized in local treatment of keratoplasty rejection. OBJECTIVE:To investigate the inhibitory effect of new immunosuppressive agent J2 on CD4+ and CD8+T cel immune functions in rat models receiving alogenic penetrating keratoplasty. METHODS:Alogeneic penetrating keratoplasty model was established using the adult female Wistar rats as donors and Sprague-Dawley rats as recipients. Group A: normal Sprague-Dawley rats were injected with 0.05 mL placebo subconjunctivaly. Surgery rats were randomly divided into three groups. Group B: alograft rats were injected with 0.05 mL placebo subconjunctivaly after autologous keratoplasty. Group C: alograft rats were injected with 0.05 mL placebo subconjunctivaly. Group D: alograft rats were injected with 1% J2-nanosuspension 0.05 mL subconjunctivaly. The distribution of T cel subsets in peripheral blood was detected using flow cytometry at 3 days, 1, 2 and 3 weeks after transplantation and compared among groups. RESULTS AND CONCLUSION: There was no significant difference in total CD3+ T cels, CD4+ T cels, CD8+ T cels and CD4+/CD8+ in peripheral blood lymphocytes in group B at various time points. At 3 days and 1 week after surgery in group C, no significant difference in total CD3+ T cels, CD4+ T cels and CD8+ T cels was detected. At 1 and 2 weeks, the number of total CD3+ T cels, CD4+ T cels and CD8+ T cels increased, showing significant differences (P < 0.05). In group D, no significant hyperplasy was found in CD4+ T cels and CD8+ T cels at 1 and 2 weeks. The horizontal comparison of the same time point: the total CD3+ T lymphocytes of group D was significantly less than group C at 3 days, 1 and 2 weeks after operation (P < 0.05), whereas there was no significant difference at 3 weeks between the group D and group C. The number of CD4+ T lymphocytes in group D was less than in group C at 3 days and 1 week, but with no significant difference. The ratio of CD4+/CD8+ had no significant difference in group D compared with group C at 3 days, 1 and 3 weeks. J2 inhibits T lymphocyte proliferation and then inhibits T cel-mediated corneal alograft rejection.

Objective:To investigate the preventive effect of postoperative pancreatic fistula by pedicled omentum wrapping pancreaticojejunostomy in pancreaticoduodenectomy.Methods:The clinical data of 78 patients who underwent pancreaticoduodenectomy in Songjiang Hospital Affiliated to Shanghai Jiao Tong University from September 2017 to August 2020 were retrospectively analyzed. Patients were divided into the modified pancreaticojejunostomy group (conventional approach group, n=43) and the pedicled omentum wrapping pancreaticojejunostomy group (omentum wrapping group, n=35) according to the surgical mode. Postoperative pancreatic fistula, postoperative abdominal bleeding, delayed gastric emptying and postoperative hospital stay were compared between the two groups. Results:Compared with the conventional approach group, the postoperative pancreatic fistula rate in omentum wrapping group was significantly reduced (2.9% vs 18.6%), and the difference was statistically different ( P=0.030); postoperative abdominal bleeding rate(0 vs 4.7%)and the delayed gastric emptying rate were significantly reduced (8.6% vs 25.6%), but both of them were not statistically different ( all P value>0.05); the length of postoperative hospital stay was significantly reduced [(11.3±2.9) days vs (12.8±3.5)days], and the difference was statistically different ( P=0.045). Conclusions:The pedicled omentum wrapping pancreaticojejunostomy was simple and convenient, which can significantly reduce the rate of postoperative pancreatic fistula. It can shorten the time of the length of hospital stay after surgery.

Aging is a major risk factor for diseases such as osteoarthritis (OA) and osteoporosis. However, they are not necessarily the results of aging, and the relationship between changes in bone and cartilage associated with aging and disease progression is still unclear. Studies have shown that the development and progression of OA is not a simple cartilage wear process, while its occurrence involves complex biological, chemical and mechanical changes in the tissues of the entire joint, especially the interaction of mechanics and biochemistry between cartilage and subchondral bone. Aging contributes to the occurrence and development of OA, but it is not the cause of OA. Changes associated with aging provide a foundation for OA to start, making joints more susceptible to other factors such as abnormal biomechanics and biochemistry, thereby promoting the development of OA. Therefore, understanding the basic mechanisms by which aging affects joint tissue may provide new targets for slowing or preventing the development of OA. In this paper, the related research progresses are reviewed from three aspects, i.e. age-related changes in cartilage and subchondral bone, mechanical conduction and angiogenesis.

With the increasing life span of the population and the increasing proportion of the elderly population, the elderly with osteoporosis are prone to hip fractures, which brings heavy economic burdens to the family and society. The progress in predicting hip fractures from the aspects of the proximal femur geometry, bone mineral density (BMD), fracture risk assessment tool (FRAX) and finite element analysis (FEA) based on computed tomography (CT) imaging was reviewed, in order to understand the influencing factors of fracture risk, improve the accuracy of hip fracture risk prediction for the elderly, detect the high fracture risk group at an early stage, and hence to reduce the occurrence of fractures with appropriate preventing measures, and provide theoretical references for the prevention and treatment of hip fractures.

Objective To study the change patterns of bone microstructural parameters around the magnesium based- implants after implantation in rabbit femur at different implantation time points. Methods The threaded and non-threaded high-purity magnesium (HP Mg, 99.99 wt.%) screws, with a 2 mm diameter and a 7 mm length, were implanted into the femoral condyle of the rabbits. The control group was the drilled and healthy group. Micro-CT scanning and analysis were performed at 8th, 12th and 16th week after operation. The obtained microstructural parameters included bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp). Results At 8th week, BMD and BV/TV in non-threaded magnesium screw group were significantly higher than those in healthy group, Tb.N was significantly higher than that in drilled and healthy group, and Tb.Sp was significantly lower than that in healthy group. At 12th week, BMD, BV/TV and Tb.N in threaded magnesium screw group were significantly higher than those in drilled and healthy group, Tb.Th was significantly higher than that in healthy group, and Tb.Sp was significantly lower than that in drilled and healthy group. At 16th week, BMD, BV/TV and Tb.N in non-threaded magnesium screw group were significantly higher than those in drilled and healthy group, and Tb.Sp was significantly lower than that in drilled and healthy group. Conclusions The magnesium based-implant promoted higher BMD, BV/TV, Tb.Th, Tb.N and lower Tb.Sp of surrounding implant, indicating that osseointegration and bone growth were in good condition. Magnesium based-implant could effectively promote the regeneration of bone. The results provide a theoretical basis for the orthopedic application of magnesium based-implants in clinic.