[Objective] To compare the characteristics of platelet-rich plasma derived exosomes (PRP-Exos) under different activation conditions and their differential effects on the proliferation capacit of human microvascular endothelial cells (HMEC-1) and human skin fibroblasts (BJ). [Methods] Ten healthy volunteers were recruited, and 10 mL of venous blood anticoagulated with EDTA-K2 was collected. PRP-Exos were prepared and extracted by the secondary centrifugation method. Transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blotting (WB) detection techniques were used to compare the morphological characteristics, particle size distribution, concentration, and the expression of surface marker proteins of PRP-Exos. Through in vitro cell culture, the differences in morphological changes and proliferation abilities of HMEC-1 and BJ cells induced by PRP-Exos in different activator groups were compared. [Results] 1) TEM observation showed that the morphologies of PRP-Exos in different activator groups were different. 2) NTA analysis showed that compared with the particle size of (109.60±2.71) nm in the normal saline group, the particle sizes of the thrombin group [(104.93±1.55) nm] and the mixed agent group [(103.83±1.58) nm] were relatively smaller, while the particle size of the calcium gluconate group [(113.57±4.70) nm] was larger and its particle size distribution range was wider. There were statistically significant differences among different groups (F=7.019, P<0.05). The concentration of exosomes obtained in the group with the mixture of calcium gluconate and thrombin was the highest [(4.87±0.63)×10⁶ particles/mL, P<0.001]. Both the thrombin group [(2.75±0.13)×10⁶ particles/mL, P < 0.01] and the calcium gluconate group [(3.82±0.06)×10⁶ particles/mL, P<0.001] obtained higher concentrations of exosomes compared with the normal saline group. The concentration in the calcium gluconate group was slightly higher than that in the thrombin group, and there was a significant difference between the two groups (P<0.05). 3) WB analysis showed that CD41, CD81, and TSG101 were expressed on the surface of PRP-Exos, and the protein signal intensities of CD41 and TSG101 in the group with the mixture of thrombin and calcium gluconate were the strongest (P<0.001). 4) The results of in vitro cell culture showed that PRP-Exos in the group with the mixture of thrombin and calcium gluconate could significantly promote the proliferation of HMEC-1 and BJ cells (P<0.05). [Conclusion] The PRP treated with the thrombin and calcium gluconate mixture group yielded the highest concentration of exosomes; under in vitro culture conditions, PRP-Exos from this group significantly promoted the proliferation of HMEC-1 and BJ cells.

Objective To investigate the influence of different cell structures on the static and dynamic mechanical performance of porous titanium alloy scaffolds,and to provide a theoretical mechanical basis for the application of scaffolds in the repair of mandibular bone defects.Methods Porous titanium alloy scaffolds with diamond,cubic,and cross-sectional cubic cell structures were manufactured using three-dimensional printing technology.Uniaxial compression tests and ratcheting fatigue with compression load tests were conducted to analyze the static and dynamic mechanical performances of scaffolds with different cell structures.Results The elastic moduli of the diamond cell,cross-sectional cubic cell,and cubic cell scaffolds were 1.17,0.566,and 0.322 GPa,respectively,and the yield strengths were 71.8,65.1,and 31.8 MPa,respectively.After reaching the stable stage,the ratcheting strains of the cross-sectional cubic,diamond,and cubic cell scaffolds were 3.3%,4.0%,and 4.5%,respectively.The ratcheting strain increased with increasing average stress,stress amplitude,and peak holding time,and decreased with increasing loading rate.Conclusions The evaluation results of the static mechanical performance showed that the diamond cell scaffold was the best,followed by the cross-sectional cubic cell scaffold and the cubic cell scaffold.The evaluation results of the dynamic mechanical performance showed that the cross-sectional cubic cell scaffold performed the best,followed by the diamond cell scaffold,whereas the cubic cell scaffold performed the worst.The fatigue performance of the scaffold is affected by the loading conditions.These results provide new insights for scaffold construction for the repair of mandibular bone defects and provide an experimental basis for further clinical applications of this scaffold technology.

Objective To study the changes in serum immunoglobulin levels in children with thalassemia who undergo repeated blood transfusions and explore their correlation with delayed hemolytic transfusion reactions(DHTR).Methods Serum samples from children with thalassemia who received blood transfusion treatment from June 2022 to April 2023(ob-servation group)and healthy children who underwent physical examination(control group)in our hospital were collected.The levels of serum immunoglobulins(IgG subtype,IgM,IgA,IgE and IgD)were detected using flow cytometry CBA multi-factor quantitative detection technology,and the differences between the two groups were compared.The children were divided into 4 groups according to different transfusion numbers:≤10 numbers,11-30 numbers,31-50 numbers and＞50 numbers,and the differences between different blood transfusion numbers and serum immunoglobulin levels in each group were compared using one-way analysis of variance(ANOVA).Children with thalassemia with DHTR were in the hemolysis group,and children with thalassemia who did not experience DHTR were in the non-hemolysis group.The changes in serum immunoglobulins(IgG subtypes,IgM,IgA,IgE and IgD)between the two groups were compared to explore the correlation between serum immunoglobulins in thalassemia children with repeated transfusion and DHTR.Results The levels of IgG1,IgG3,IgG4 and IgA in the observation group were significantly higher than those in the control group,with the increase of(2.07±2.12),(0.67±2.03),(0.30±0.37)and(6.04±11.40)mg/mL,respectively,while the level of IgD in observation group was significantly lower than that in the control group,with a decrease of(0.03±0.01)mg/mL,P＜0.05.No significant difference was noticed in IgG2,IgM and IgE between the groups(P＞0.05).IgG1 and IgG4 both significantly increased with the number of blood transfusions.The IgG1 in the 4 groups increased sequentially as(0.30±0.62),(0.41±0.51)and(3.60±3.48)mg/mL,and IgG4 increased sequentially as(0.12±0.13),(0.22±0.07)and(0.21±0.38)mg/mL.IgG2,IgM and IgD showed a significant decrease,with IgG 2,IgM,and IgD in four groups decreased as(0.91±1.50),(0.14±0.10)and(0.05±0.05)mg/mL,respectively,showing significant differences with the number of blood transfusions(P＜0.05).No sig-nificant difference was found in IgG3,IgA and IgE with different number of transfusions(P＞0.05).IgG1,IgG3 and IgG4 in the hemolysis group were significantly higher than those in the non-hemolysis group,with an increase of(4.44±3.41),(0.73±1.26)and(0.52±0.40),respectively(P＜0.05).IgD in the hemolysis group was significantly lower than that in the non-hemolysis group,with a decrease of(0.00±0.06)mg/mL,P＜0.05.No significance was noticed in IgG2,IgM,IgA and IgE between the hemolysis group and the non-hemolysis group(P＞0.05).Conclusion The serum immunoglobulin levels of children with thalassemia who undergo repeated blood transfusions are abnormal.There are differences in correlation between the number of blood transfusions and serum immunoglobulin levels among children with thalassemia who undergo repeated blood transfusions.The relevant serum immunoglobulins for DHTR in children with thalassemia who undergo repeated blood transfusions are IgG1,IgG3 and IgG4.

Objective To assess the level of self-compassion in patients with lung cancer undergoing chemotherapy and identify its influencing factors in order to provide targeted intervention strategies for clinical nursing practice.Methods Using a convenience sampling method,a total of 110 patients with lung cancer who were hospitalized for chemotherapy in Fujian Cancer Hospital from January 2022 to December 2023 were selected.A general information questionnaire,self-compassion scale,M.D.Anderson symptom inventory-lung cancer,and perceived social support scale were used to investigate.Results The total score for self-compassion among lung cancer chemotherapy patients was(76.81±9.49)points,the total score for symptom burden was(112.05±35.98)points,and the total score for social support was(38.98±2.49)points.Self-compassion was negatively correlated with symptom burden(r=-0.849,P＜0.001)and positively correlated with social support(r=0.881,P＜0.001).Multiple linear regression analysis showed that age,gender,symptom burden and social support were the influencing factors of self-compassion in patients with lung cancer chemotherapy(P＜0.05).Conclusion The level of self-compassion among lung cancer chemotherapy patients is moderately low.Age,gender,symptom burden and social support were the factors influencing self-compassion of patients with lung cancer chemotherapy.Nursing staff should consider demographic characteristics and use strategies such as reducing symptom burden and improving social support to enhance self-compassion levels,thereby reducing negative emotions and improving the quality of life.

【Objective】 To investigate the changes in cellular immunity (peripheral blood lymphocyte subsets) and humoral immunity (serum immunoglobulin and ferritin) status among children with thalassemia who received repeated transfusions in Yunnan. 【Methods】 Forty-six children with thalassemia who underwent repeated blood transfusions from January 2020 to October 2022 were selected as the observation group. Forty children with thalassemia who did not receive blood transfusion were included in control group 1, and 46 healthy children underwent physical examination were included in control group 2. The differences in lymphocyte subsets, serum immunoglobulin levels and ferritin concentrations were compared among the three groups. 【Results】 For lymphocyte subsets: CD3⁺, CD4⁺ and CD4⁺/CD8⁺ in the observation group was lower than the control group 1 and 2: 57.60±8.36 vs 64.57±7.56 vs 66.58±5.65, 33.16±5.67 vs 38.62±8.36 vs 38.62±6.41 and 1.49±0.09 vs 2.32±0.15 vs 2.13±0.16, respectively; CD16⁺ CD56⁺ in the observation group was lower than the control group 2: 11.21±5.06 vs 16.70±7.92; CD8⁺ in the observation group was higher than control group 1 and control group 2: 26.63± 1.75 vs 20.60±1.43 vs 18.92±0.84; CD19⁺ in the observation group was higher than the control group 2: 24.06±6.42 vs 19.67 ±8.42, P<0.05, but no significant difference was noticed between the two control groups(P>0.05). For serum immunoglobulin and ferritin: IgG and ferritin in the observation group were higher than control group 1 and control group 2: 10.59±3.88 vs 7.02±3.88 vs 5.58±1.98 and 2 037.37±1 377.59 vs 72.63±56.71 vs 59.48±33.88. IgA in the observation group was higher than the control group 2: 1.06±0.92 vs 0.39±0.32(P<0.05), but no significant difference was noticed between the two control groups (P>0.05). The difference of IgM and IgE between the three groups was not significant (P > 0. 05). 【Conclusion】 The proportion of lymphocyte subsets in thalassemia children with repeated blood transfusion was imbalanced,and the level of immunoglobulin in humoral immunity was abnormal.

【Objective】 To share the experience of autologous platelet-rich plasma(PRP) combined therapy in successful treatment of refractory osteomyelitis with fractures in children. 【Methods】 One case of refractory osteomyelitis with fracture in children failed to respond to traditional treatment for more than 14 months. A total of 20 mL of whole blood was collected from the child, and 6 mL of PRP with 4 to 5 times concentration was prepared by secondary centrifugation. To prepare 2 cm×2 cm platelet concentrate gel (PG), 3 mL of PRP was mixed with a 0.3 mL activator which was then covered with an absorbable dressing. A three-way tube sprayed the remaining 3 mL of PRP and 0.3 mL activator into the surrounding tissues. 【Results】 The X-ray film of the patient followed up for 1 week showed that the fracture line was blurred, and the fracture end had obvious callus formation. The X-ray film reexamination at 4 months showed that the fracture end healed well, the fracture surface healed, and the osteomyelitis healed. 【Conclusion】 Autologous PRP has a good effect in the treatment of refractory osteomyelitis combined with fracture in children, which can provide a new method for clinical treatment.

OBJECTIVE: To explore the mechanism underlying the inhibitory effect of quercetin against testicular oxidative damage induced by a mixture of 3 commonly used phthalates (MPEs) in rats. METHODS: Forty male Sprague-Dawley rats were randomly divided into control group, MPEs exposure group, and MPEs with low-, median- and high-dose quercetin treatment groups. For MPEs exposure, the rats were subjected to intragastric administration of MPEs at the daily dose of 900 mg/kg for 30 consecutive days; Quercetin treatments were administered in the same manner at the daily dose of 10, 30, and 90 mg/kg. After the treatments, serum levels of testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), and testicular malondialdeyhde (MDA), catalase (CAT) and superoxide dismutase (SOD) were detected, and testicular pathologies of the rats were observed with HE staining. The expressions of nuclear factor-E2-related factor 2 (Nrf2), Kelch-like ECH2 associated protein 1 (Keap1) and heme oxygenase 1 (HO-1) in the testis were detected using immunofluorescence assay and Western blotting. RESULTS: Compared with the control group, the rats with MPEs exposure showed significant reductions of the anogenital distance, weight of the testis and epididymis, and the coefficients of the testis and epididymis with lowered serum testosterone, LH and FSH levels (P < 0.05). Testicular histological examination revealed atrophy of the seminiferous tubules, spermatogenic arrest, and hyperplasia of the Leydig cells in MPEs-exposed rats. MPEs exposure also caused significant increments of testicular Nrf2, MDA, SOD, CAT and HO-1 expressions and lowered testicular Keap1 expression (P < 0.05). Treatment with quercetin at the median and high doses significantly ameliorated the pathological changes induced by MPEs exposure (P < 0.05). CONCLUSION Quercetin treatment inhibits MPEs-induced oxidative testicular damage in rats possibly by direct scavenging of free radicals to lower testicular oxidative stress and restore the regulation of the Nrf2 signaling pathway.
Rats ; Male ; Animals ; Testis ; Quercetin/pharmacology* ; Rats, Sprague-Dawley ; NF-E2-Related Factor 2/metabolism* ; Kelch-Like ECH-Associated Protein 1/metabolism* ; Oxidative Stress ; Testosterone/pharmacology* ; Superoxide Dismutase/metabolism* ; Follicle Stimulating Hormone ; Luteinizing Hormone

As a kind of elastic load-bearing connective tissues on bone surface in dynamic joints, articular cartilage can provide low wear lubrication, shock absorption, load transfer and other supporting functions, and has hierarchical fiber composite structures and excellent mechanical properties. As an avascular and aneural tissue,the degenerated articular cartilage lacks the capability of self-healing after damage. The high incidence of arthritisis still a hot spot in basic and clinical researches. Articular cartilage is a mechanical sensitive tissue, andmechanical environment will affect the development of tissues in different directions. Extensive researches onbiomechanics and mechanobiology of articular cartilage were conducted in 2022. Many studies on morphology, function and mechanical state of cartilage,as well as mechanical state of cartilage under different conditions were reported. Some cartilage-related loading devices were designed at animal, tissue and cell levels. Researches onthe repair of cartilage degeneration and injury under mechanical loads were carried out in vitro and in vivo, andsome important repair method and means were obtained. The biomechanical and mechanobiology research on articular cartilage is the basis of arthritis, cartilage defect and repair. The influence of quantitative mechanical under 4 conditions on the repair of articular cartilage injury needs further study in vivo and in vitro

Objective To study stress relaxation behaviors of cartilage scaffolds under different degradation cycles by using finite element analysis combined with theoretical models. Methods Based on the established degradation theoretical model, the elastic modulus of the scaffold was calculated under different degradation cycles. The finite element model of cartilage scaffolds was established and stress relaxation simulation was performed to analyze the variation of scaffold relaxation stress with time. The stress relaxation constitutive model was established to predict mechanical properties of the scaffold. Results The elastic modulus of cartilage scaffolds at 14 th, 28th, 42nd, 56th day after degradation was 32. 35, 31. 12, 29. 91, 28. 74 kPa, respectively. The upper layer for cartilage scaffolds was the largest. The overall relaxation stress of the scaffold decreased rapidly with time and then tended to be stable. At 8th week after degradation, the stress which the scaffold couldwithstand was still within the physiological load range of the cartilage. The predicted results of the stress relaxation constitutive model were in good agreement with the finite element simulation results. Conclusions The elastic modulus of the scaffold gradually decreases with the increase of degradation time. The longer the degradation period is, the less stress the scaffold can withstand. At the same degradation period, the larger the applied compressive strain, the larger the stress on the scaffold. Both the finite element simulation and stress relaxation constitutive model can effectively predict stress variations of cartilage scaffolds under degradation

Objective To study the effect of irrigation mechanical stimulation on scaffold degradation by numerical simulation, so as to predict its degradation degree. MethodsBased on perfusion experimental data, the fluid-solid coupling model was established by Comsol. The finite element model of scaffold was established by ABAQUS. Based on the models, the degradation performance of scaffold was simulated and predicted. Results The fluid-solid coupling simulation showed that the initial pressure at the speed of 15.79 mL/min was two-fold of that at 7.89 mL/min. Along the thickness of scaffold from the surface to the bottom, the pressures between the two velocities were decreased and gradually close to each other. The degradation of scaffold structure could be simulated dynamically by combining the degradation constitutive model with the finite element model. The obtained degradation data were consistent with the experimental data, and the residual molecular weight reached 0.643 on the 56th day. Compared with the experimental data, the simulation accuracy was higher than 98%. Conclusions The larger the perfusion velocity is, the greater the pressure on scaffold will be. Under the same perfusion velocity, the maximum force occurs on the surface of scaffold. The degradation pattern of scaffold can be predicted by applying the degradation constitutive model and the finite element model.