Objective To investigate the effect of dexamethasone, recombinant human fibroblast growth factor (rhFGF) and recombinant human bone morphogenetic protein 2 (rhBMP-2) on the proliferation and differentiation of marrow stromal stem cells (MSCs) for their further application in tissue engineering. Methods MSCs were isolated and cultured in vitro, and then exposed to different dose of dexamethasone (10-8 mol/L,10-7 mol/L,10 -6 mol/L), rhFGF (50 ng/ml,200 ng/ml,500 ng/ml) and rhBMP-2 (50 ng/ml,500 ng/ml,1 000 ng/ml) respectively. The total protein and alkaline phosphatase (ALP) activity of each group was measured on 4th and 7th day. Results Exposure of MSCs with 10-6mol/L dexamethasone inhibited protein synthesis without obvious effects on ALP expression. The application of rhFGF significantly promoted cell proliferation but inhibited ALP activity. In comparison, ALP expression was significantly enhanced by treatment of rhBMP-2 at concentration of 500 ng/ml，1 000 ng/ml. Conclusion The exposure of dexamethasone as well as rhBMP-2 to MSCs with an appropriate concentration promotes osteogenic expression without reverse effects on cell proliferation, which indicates the great potential value in cell-based strategy of bone tissue engineering.
ObjectiveTo observe the effects of bulbar subconjunctival and periocular injection of dexamethasonone on blood glucose levels of type 1 diabetic mellitus (T1DM)rats.
Methods80 healthy adult male Sprague-Dawley rats were randomly divided into GroupⅠ(n=40) and GroupⅡ(n=40). GroupⅠrats received intraperitoneal (IP) injection of streptozotocin to induce T1DM model, while GroupⅡrats received IP injection of citrate buffer solution and was the control group.GroupⅠrats and GroupⅡrats were further divided into four subgroups:A (n=10), a (n=10), B (n=10), and b (n=10). Subgroup-A rats received bulbar subconjunctival injection of dexamethasone, subgroup-a rats received bulbar subconjunctival injection of saline, subgroup-B rats received periocular injection of dexamethasone, subgroup-b rats received periocular injection of saline. After the injection, rats were fasted but could drink water. Tail vein blood samples were collected and the blood glucose level was measured by glucose monitor.
ResultsAfter modeling, the blood glucose level of GroupⅠand GroupⅡrats was(9.31±1.79) mmol/L and (5.72±0.80) mmol/L respectively, the difference was statistically significant (P < 0.05). The blood glucose level of GroupⅠrats reached the peak in 3h after injection. In 6-24 h after injection, the blood glucose level of GroupⅠA rats was obviously increased than that of the blood glucose level of Group Ia rats and the difference was statistically significant (P < 0.05). In 3-24 hours after injection, the blood glucose level of GroupⅠB rats was obviously increased than that of the blood glucose level of GroupⅠb rats and the difference was statistically significant (P < 0.05). Comparing the blood glucose level during different injection time between GroupⅠA rats and GroupⅠB rats, between GroupⅠa rats and GroupⅠb rats, the difference was not statistically significant (P > 0.05). In 3-24 hours after injection, the blood glucose level of GroupⅡA rats was obviously increased than that of the blood glucose level of GroupⅡa rats and the difference was statistically significant (P < 0.05); the blood glucose level of GroupⅡB rats was obviously increased than that of the blood glucose level of GroupⅡb rats and the difference was statistically significant (P < 0.05). Comparing the blood glucose level during different injection time between GroupⅡA rats and GroupⅡB rats, between GroupⅡa rats and GroupⅡb rats, the difference was not statistically significant (P > 0.05).
ConclusionBulbar subconjunctival injection and periocular injection of dexamethasone could both increase the blood glucose of TIDM rats, but these two injection methods had no differences on the blood glucose level.
Objective To investigate the mechanism of dexamethasone in the treatment of acute necrotizing pancreatitis (ANP). Methods The ANP of 48 SD rats were induced by retrograde infusion of sodium taurocholate through biliopancreatic duct.After 30 minutes,the therapy group was administrated with dexamethasone at a dose of 0.2 mg/100 g alone. The control group was administrated with the same amount of 0.9% saline solution.At fourth hour and twelfth hour,8 rats of each group were sacrificed to examine the levels of serum tumor necrosis factor-alpha(TNFα) and serum amylase,to score the degree of pancreatic necrosis and to evaluate acinar cell apoptosis by in situ hybridization by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling(TUNEL). The survial period of 8 rats in each group were observed. Results In therapy group, the level of TNFα was (17.8±2.7) pg/ml and (8.5±1.6) pg/ml,the apoptosis index was （36.94±4.12）% and （ 32.79±3.31）%,the survival period was (33.4±21.5) h.While the control group with the indexes mentioned above were as follows: (53.6±18.7) pg/ml and (37.2±11.1) pg/ml ( P＜0.01),（4.37±1.24）% and （5.12±2.11）% （P＜0.01）,(14.6±5.7) h (P＜0.01) ,the histologic scoring for ANP between therapy group and control group was a significantly distinct (P＜0.01). Conclusion Dexamethasone can induce pancreatic acinar cell apoptosis in this model. Proper leves of TNFα may play an important role in regulating the apoptosis.Apoptosis can protect pancreas from necrosis in ANP.
OBJECTIVE: To investigate the effects of dexamethasone on the proliferation and differentiation of bone marrow stromal cells(MSC). METHODS: MSC were isolated and cultured in vitro. After treatment with different concentrations of dexamethasone (0, 10-10, 10-9, 10-8, 10-7 and 10-6 mol/L), the proliferation and alkaline phosphatase (ALP) activity of MSC were measured to evaluate the effect of dexamethasone on the biological characteristics of MSC. RESULTS: Dexamethasone inhibited cell proliferation. With the increase of concentration of dexamethasone, the effect was enhanced, which was more significant when the concentration of dexamethasone was over 10-8 mol/L. At the same time, dexamethasone promoted the activity of ALP. This effect was enhanced with the increase of concentration of dexamethasone, but the alteration was small when the concentration of dexamethasone was over 10-8 mol/L. The effects increased with the time. The activity of ALP was enhanced 2 to 4 times with the dexamethasone for 6 days. CONCLUSION: Dexamethasone inhabit the proliferation of MSC, while induce them to differentiate into osteoblasts. The appropriate concentration of dexamethasone was 10-8 mol/L.
Objective Dexamethasone (DXM) can regulate the balance of neutrophil and cytokine and enhance the ischemia-reperfusion tolerance of the skin flap; amlodipine besylate (AB) can selectively expand the peripheral blood vesselsand rel ieve the vascular smooth muscle spasm. To investigate the percutaneous penetration abil ity of DXM/AB compound gel and evaluate its effect on survival of ischemic skin flap. Methods Sodium carboxymethylcellulose was used to make blank gel, which was mixed in DXM, AB, azone (AZ), and progylene glycol (PG) respectively to make the compound gel containing 0.3%DXM/0.5%AB only (group D), the compound gel containing 3%AZ/2%PG, 3%AZ, and 2%PG (groups A, B, and C), the 0.3%DXM gel containing 3%AZ/2%PG (group E), the 0.5%AB gel containing 3%AZ/2%PG (group F). The accumulative penetration of DXM and AB in compound gel, 0.3%DXM gel, 0.5%AB gel through excised rat skin and its penetration within flap tissue were investigated by ultraviolet spectrophotometry. Fifty SD rats were selected to make 100 mm × 10 mm random flap at the back, and were randomly divided into 5 groups according to different gels which were used to treat flaps (n=10): compound gel group (group A1), 0.3%DXM gel group (group B1), 0.5%AB gel group (group C1), blank gel group (group D1), and peritoneal injection of DXM (5 mg/kg) and AB (2 mg/kg) (group E1). The survival area of ischemic random skin flap was measured on the 7th day by planimetry. Twenty-four SD rats were selected to make 100 mm × 10 mm random flap at the back, and were randomly divided into 2 groups (n=12). The accumulative penetration of DXM and AB within skin flap were also detected at 2 and 6 hours after appl ication of 2 g of compound gel containing 3%AZ/2%PG (group A2) and peritoneal injection AB (2 mg/kg) / DXM (5 mg/kg) (group B2). Results The accumulative penetration of DXM and AB in compound gel were increased in time-dependent manner (P lt; 0.05), and it was the highest in group A, and was significantly higher than that in group B and group C (P lt; 0.01), but there was no significant difference when compared with group E or group F (P gt; 0.05). The accumulative penetration of DXM and AB in groups A, B, and C were significant higher than that in group D (P lt; 0.05). After 7 days, the survival area of flaps in groups A1, B1, C1, D1, and E1 were (695.0 ± 4.6), (439.3 ± 7.1), (477.5 ± 14.5), (215.2 ± 3.8), and (569.4 ± 9.7) mm2, respectively; group A1 was significantly higher than other groups (P lt; 0.05). After 2 and 6 hours, the quantities of DXM and AB in skin flap of group A2 were significantly higher than that of group B2 (P lt; 0.05). Conclusion In 0.3%DXM/0.5%AB compound gel, DXM and AB might penetrate into skin tissue, which could significantly increase the survivalarea of ischemic skin flap.
Objective To observe the efficacy and safety of pars plana vitrectomy (PPV) combined with subretinal injection of dexamethasone in treating refractory diabetic macular edema (DME). MethodsA prospective case study. From January 2024 to March 2024, 9 cases with 10 eyes of refractory DME diagnosed at Tianjin Eye Hospital were included in the study. All eyes had a central macular thickness (CMT) of greater than 275 μm despite receiving intravitreal injection of anti-vascular endothelial growth factor (VEGF) drug at least 5 times. All eyes underwent 25G PPV combined with internal limiting membrane (ILM) peeling and subretinal injection of dexamethasone sodium phosphate. Best-corrected visual acuity (BCVA), microperimetry, and optical coherence tomography examinations were performed on all eyes before and 1 and 3 months after surgery. BCVA was assessed using an international standard visual acuity chart and converted to logarithm of the minimum angle of resolution (logMAR) for statistical analysis. Paired t-tests were used to compare changes in BCVA, mean macular sensitivity (MS), and CMT before and after surgery. The intraoperative and postoperative complications were recorded. ResultsAmong the 9 cases with 10 eyes, there were 4 males with 5 eyes and 5 females with 5 eyes. Age ranged from 43 to 79 (65.3±10.8) years. Preoperative and postoperative logMAR BCVA at 1 and 3 months were 0.84±0.25, 0.72±0.31, and 0.63±0.22, respectively. MS was (16.48±5.03), (16.6±6.31), and (18.0±5.33) dB, respectively. CMT was (437.5±90.4), (306.9±87.4), and (288.7±87.3) μm, respectively. Compared with data before surgery, BCVA: the difference was not statistically significant at 1 month (t=2.025, P=0.074), but was statistically significant at 3 months (t=5.161, P=0.001), MS: the differences at 1 and 3 months were not statistically significant (t=－0.078, －1.022, P=0.940, 0.334), CMT: the differences were of statistical significance at both 1 and 3 months (t=2.892, 3.175, P=0.018, 0.011), and the difference between 1 and 3 months post-surgery was also statistically significant (t=2.427, P=0.038). No complications such as macular hole, vitreous hemorrhage, or retinal detachment occurred during or after surgery in any eyes. No cases of increased intraocular pressure or cataracts were reported during the follow-up period. ConclusionPPV combined with ILM peeling and subretinal injection of dexamethasone can effectively reduce CMT in refractory DME eyes and improve visual acuity, with good safety.
OBJECTIVE: To study the hemorheology of island flap after ischemia-reperfusion injury and modulation of dexamethasone. METHODS: Sixty Wister rats were made ischemia-reperfusion injury model, and divided into two groups randomly(Group I: intraperitoneal injection of normal saline 2 ml/kg as control group; Group II: intraperitoneal injection of dexamethasone 5 mg/kg as experimental group). Flap survived areas were measured and neutrophil necrosis numbers in flaps were counted. Erythrocytes and neutrophil hemorheology were observed. RESULTS: Area survived flap in group II was larger than that in group I. Neutrophil necrosis numbers were less in group II than in group I (P lt; 0.05). Whole blood hyposhear viscosity, erythrocyte aggregation, Casson yield stress and nerutrophil adhesion ability were higher in group I than in group II (P lt; 0.05); and the neutrophil deformability was lower in group I than in group II. CONCLUSION: Flap inchemia-reperfusion can increase erythrocyte aggregation index and neutrophil adhesion ability. Dexamethasone can improve these and decrease neutrophil necrosis numbers, so as to prevent flap from ischemia-reperfusion injury.
ObjectiveTo study the effect of transforming growth factor β3 (TGF-β3), bone morphogenetic protein 2 (BMP-2), and dexamethasone (DEX) on the chondrogenic differentiation of rabbit synovial mesenchymal stem cells (SMSCs).
MethodsSMSCs were isolated from the knee joints of 5 rabbits (weighing, 1.8-2.5 kg), and were identified by morphogenetic observation, flow cytometry detection for cell surface antigen, and adipogenic and osteogenic differentiations. The SMSCs were cultured in the PELLET system for chondrogenic differentiation. The cell pellets were divided into 8 groups: TGF-β3 was added in group A, BMP-2 in group B, DEX in group C, TGF-β3+BMP-2 in group C, TGF-β3+DEX in group E, BMP-2+DEX in group F, and TGF-β3+BMP-2+DEX in group G; group H served as control group. The diameter, weight, collagen type II (immuohistochemistry staining), proteoglycan (toluidine blue staining), and expression of cartilage related genes [real time quantitative PCR (RT-qPCR) technique] were compared to evaluate the effect of cytokines on the chondrogenic differentiation of SMSCs. Meanwhile, the DNA content of cell pellets was tested to assess the relationship between the increase weight of cell pellets and the cell proliferation.
ResultsSMSCs were isolated from the knee joints of rabbits successfully and the findings indicated that the rabbit synovium-derived cells had characteristics of mesenchymal stem cells. The diameter, weight, collagen type II, proteoglycan, and expression of cartilage related genes of pellets in groups A-F were significantly lower than those of group G (P<0.05). RT-qPCR detection results showed that the relative expressions of cartilage related genes (SOX-9, Aggrecan, collagen type II, collagen type X, and BMP receptor II) in group G were significantly higher than those in the other groups (P<0.01). Meanwhile, with the increase of the volume of pellet, the DNA content reduced about 70% at 7 days, about 80% at 14 days, and about 88% at 21 days.
ConclusionThe combination of TGF-β3, BMP-2, and DEX can make the capacity of chondrogenesis of SMSCs maximized. The increase of the pellet volume is caused by the extracellular matrix rather than by cell proliferation.
ObjectiveTo systematically review the efficacy and safety of dexamethasone in the treatment of viral myocarditis.MethodsThe Cochrane Library, PubMed, EMbase, Biosis Preview, Web of Science, CBM, WanFang Data, VIP, and CNKI databases were electronically searched to collect randomized controlled trials (RCTs) on dexamethasone for patients with viral myocarditis from inception to April 30th, 2021. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.4 software.ResultsA total of 7 RCTs involving 749 patients were included. The results of meta-analysis showed that the dexamethasone treatment group exhibited an increased efficacy rate (RR=1.26, 95%CI 1.18 to 1.34, P<0.000 01), decreased levels of C-reactive protein (CRP) (MD=?11.49, 95%CI ?19.25 to ?3.72, P=0.004), cardiac troponin I (cTnI) (MD=?26.14, 95%CI ?40.82 to ?11.47, P=0.0005), and creatine kinase MB (CK-MB) (MD=?20.06, 95%CI ?28.35 to ?11.77, P<0.000 01), and a decreased adverse event rate (RR=0.40, 95%CI 0.24 to 0.65, P=0.000 3).ConclusionsCurrent evidence shows that dexamethasone can significantly improve the efficacy rate, reduce the levels of CRP, cTnI, and CK-MB, and reduce the incidence of adverse events in patients with viral myocarditis. Due to the limited quantity and quality of included studies, more high-quality studies are required to verify above conclusions.
