OBJECTIVE: To investigate the impact of bone mass and volume of low-density zones beneath the tibial plateau on the maximum von Mises stresses experienced by the cartilage and meniscus in the knee joint. METHODS: The study included one healthy adult volunteer, from whom CT scans were obtained, and one patient diagnosed with knee osteoarthrisis (KOA), for whom X-ray films were acquired. A static model of the knee joint featuring a low-density zone was established based on a normal knee model. In the finite element analysis, axial loads of 1 000 N and 1 800 N were applied to the weight-bearing region of the upper surface of the femoral head for model validation and subsequent finite element studies, respectively. The maximum von Mises stresses in the femoral cartilage, as well as the medial and lateral tibial cartilage and menisci, were observed, and the stress percentage of the medial and lateral components were concurrently analyzed. Additionally, HE staining, as well as alkaline magenta staining, were performed on the pathological specimens of patients with KOA in various low-density regions. RESULTS: The results of model validation indicated that the model was consistent with normal anatomical structures and correlated with previous calculations documented in the literature. Static analysis revealed that the maximum von Mises stress in the medial component of the normal knee was the lowest and increased with the advancement of the hypointensity zone. In contrast, the lateral component exhibited an opposing trend, with the maximum von Mises stress in the lateral component being the highest and decreasing as the hypointensity zone progressed. Additionally, the medial component experienced an increasing proportion of stress within the overall knee joint. HE staining demonstrated that the chondrocyte layer progressively deteriorated and may even disappear as the hypointensity zone expanded. Furthermore, alkaline magenta staining indicated that the severity of microfractures in the trabecular bone increased concurrently with the expansion of the hypointensity zone. CONCLUSION The presence of subtalar plateau low-density zone may aggravate joint degeneration. In clinical practice, it is necessary to pay attention to the changes in the subtalar plateau low-density zone and actively take effective measures to strengthen the bone status of the subtalar plateau low-density zone and restore the complete biomechanical function of the knee joint, in order to slow down or reverse the progression of osteoarthritis.
Humans ; Finite Element Analysis ; Knee Joint/physiology* ; Tibia/anatomy & histology* ; Cartilage, Articular/physiology* ; Menisci, Tibial/physiopathology* ; Tomography, X-Ray Computed ; Osteoarthritis, Knee/diagnostic imaging* ; Weight-Bearing ; Bone Density ; Adult ; Stress, Mechanical ; Male ; Middle Aged ; Biomechanical Phenomena ; Female

In order to strengthen the supervision of the use of drugs in hospitals，the Sichuan Academy of Medical Sciences· Sichuan Provincial People’s Hospital took the lead in compiling the Principles for the Rational Use of National Key Monitoring Drugs （the Second Batch） with a number of experts from multiple medical units in accordance with the Second Batch of National Key Monitoring Rational Drug Use List （hereinafter referred to as “the List”） issued by the National Health Commission. According to the method of the WHO Guidelines Development Manual， the writing team used the Delphi method to unify expert opinions by reading and summarizing the domestic and foreign literature evidence of related drugs， and applied the evaluation， formulation and evaluation method of recommendation grading （GRADE） to evaluate the quality of evidence formed， focusing on more than 30 drugs in the List about the evaluation of off-label indications of drugs， key points of rational drug use and key points of pharmaceutical monitoring. It aims to promote the scientific standardization and effective management of clinical medication， further improve the quality of medical services， reduce the risk of adverse drug reactions and drug abuse， promote rational drug use， and improve public health.

Objective To summarize the nursing experience of delayed closure of chest with acute renal injury after switch operation and underwent peritoneal dialysis in neonates and to improve the therapeutic effect. Methods To summarize the curative effects and perioperative nursing experience of one case of the complete transposition of great arteries with intact interventricular septum neonate who underwent delayed closure of chest with acute renal injury and peritoneal dialysis after Switch operation under general anesthesia and extracorporeal circulation in November 2017 in our department. Results The child was postponed to close the chest after surgery. Low cardiac output syndrome and acute renal function injury occurred 1 hour after operation. Through monitoring hemodynamic indexes during ICU, the child recovered after timely treatment of low cardiac output syndrome, maintaining stabilization of circulation, diuresis, peritoneal dialysis, keeping water, electrolyte and acid-base balance, nursing care for delayed closure of chest and other related treatment. Postoperative assisted mechanical ventilation time was 168 hours, postoperative ICU hospitalization time was 12 days, and postoperative total hospitalization time was 19 days. Conclusion The infants who have complete transposition of the great arteries and the intact interventricular septum after Switch operation have many complications and rapid changes in the state of illness. Rigorous and meticulous nursing plays a key role in reducing the postoperative complications and improving the achievement ratio of the operation.

Objective To investigate the safety and clinical outcome of laparoscopic resection of rectal cancer. Methods The clinical data of 347 patients with rectal cancer who were admitted to the Shanxi Tumor Hospital from May 2004 to July 2008 were prospectively analyzed. Of all the patients, 343 met the inclusion criteria,and they were randomly allocated to laparoscope group (n = 169) and open group (n= 174). The diameter of the tumors, number of lymph node dissected, length of rectum resected, morbidity, the mean operation time, number of patients receiving blood transfusion, time to out-of-bed activity, first flatus, bowel movement and liquid diet were observed. All data were analyzed using the t test and chi-square test. The survival rate was calculated using the Kaplan-Meier method. Results The diameter of the tumors, number of lymph node dissected, length of rectum resected and number of patients receiving blood transfusion in the laparoscope group were (4.3 ± 1.3 ) cm, 7 ± 5,(19.1±2.2)cm and 4, and they were (4.2±1.3)cm, 7 ±5, (19.0±2.3)cm and 8 in the open group,respectively, with no significant difference between the two groups ( t = 0. 629, - 0. 726, 0. 562, x2 = 1. 264,P ＞0.05). The mean operation time in the laparoscope group was 19 minutes longer than that in the open group (t = 7. 904, P ＜ 0.05 ). The time to out-of-bed activity, first flatus, bowel movement and liquid diet in the laparoscope group were 0.6, 0.3, 0.3 and 0.6 days earlier than those in open group( t = - 6. 392, - 3.581, - 3. 802,- 3. 493, P ＜ 0.05 ). There were no significant differences in postoperative infection, anastomotic leakage, intestinal obstruction and deep vein thrombosis between the two groups ( x2 = 0. 236, 0. 354, 0. 000, 0. 000, P ＞0.05). A total of 167 patients in the laparoscope group and 172 patients in the open group had been followed upuntil 1 may, 2010. The 1-, 2-year survival rates were 94.0% and 82.6% in the laparoscope group and 95.3% and 91.2% in the open group. There was no significant difference in the 2-year survival between the two groups (x2 =0.541, P ＞0.05). The survival time of the patients in the laparoscope group and open group were 55.9 and 57.9 months, respectively. Conclusions Laparoscopic surgery is safe and feasible for patients with rectal cancer, with quick recovery after the operation.

Objectives To observe the effects of arsenic trioxide (As2O3) on the cell cycle, differentiation and proliferation of cultured mouse melanoma Cloudman S91 cells. Methods The cell viability was measured by MTT reduction assay. The morphological changes of the cells were examined by Wright-Giemsa staining. Clone forming was carried out to test the proliferation ability. Apoptosis rate and cell cycle of S91 cells were measured by flow cytometry. Results As2O3 in the concentrations of 0.031~0.25 ?mol/L promoted cell growth markedly and blocked the transformation of cells from G0 to G1. As2O3 in the concentrations of 0.5~8.0 ?mol/L inhibited the cell growth and induced apoptosis markedly. Conclusions As2O3 has marked effects on mouse melanoma S91 cells, which include inducing apoptosis and promoting differentiation and proliferation. These effects are dose- and time-dependent.