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.
To discuss the effect of dexamethasone in preventing fat embol ism syndrome (FES) in cemented hi p arthroplasty patients. Methods Forty patients scheduled for unilateral cemented hi p arthroplasty between January 2008 and December 2009 were randomly divided into trial group (n=20) and control group (n=20). In trial group, there were 6 males and 14 females with an average age of 73.2 years (range, 54-95 years), including 4 cases of osteoarthritis, 3 cases ofavascular necrosis of femoral head, and 13 cases of femoral neck fracture; the disease duration was 4 days to 6 years (median, 0.8 year). In control group, there were 10 males and 10 females with an average age of 71.9 years (range, 59-91 years), including 2 cases of osteoarthritis, 3 cases of avascular necrosis of femoral head, and 15 cases of femoral neck fracture; the disease duration was 3 days to 5 years (median, 0.6 year). There was no significant difference in gender, age, or disease duration (P gt; 0.05) between 2 groups. Cemented total or bipolar hip arthroplasty (with the same brand of cement and prosthesis) in 2 groups were performed by a group of surgeons. The patients were given intravenously injected with dexamethasone (20 mg) in trial group before 1 hour of cement injection and intravenously injected with normal sal ine (2 mL) in control group. Amount of 5 mL vein blood were withdrawn before surgery, after 4, 8, and 24 hours of cement injection to test the number and average diameter of fat droplets. According to Gurd diagnosis standard, related FES symptoms and signs were inspected. Results Primary heal ing of incision was achieved in all cases of 2 groups. According to Gurd standard of diagnosis, no FES occurred in each group at 2 weeks postoperatively; deep venous thrombosis occurred in 2 cases (10%) of trial group and in 5 cases (25%) of control group, showing significant difference (P lt; 0.05). The number and diameter of fat droplets in trial group were significantly lower than those in control group at 4, 8, and 24 hours of cement injection (P lt; 0.01). All cases were followed up 7.4 months on average (range, 3-13 months). The postoperative Harris score was 89.5 ± 6.1 in trial group and 87.9 ± 8.3 in control group, showing no significant difference (P gt; 0.05). No loosening occurred during follow-up period. Conclusion Intravenous injection withdexamethasone can effectively reduce the number and diameter of venous fat droplets in cemented hip arthroplasty, which can decrease the risk of postoperative FES.
Objective Dexamethasone is one of the basic agents which could induce osteogenic differentiation of mesenchymal stem cells. To investigate the optimal concentration of dexamethasone in osteogenic differentiation of adiposederivedstem cells (ADSCs) so as to provide the theoretical basis for further bone tissue engineering researches. Methods FiveNew Zealand rabbits (2-3 kg) of clean grade, aged 3 months and male or female, were obtained. ADSCs were isolated from the subcutaneous adipose tissue of inguinal region, and cultured with collagenase digestion, then were detected and identified by CD44, CD106 immunofluorescence staining and adi pogenic differentiation. ADSCs at passage 3 were used and the cell density was adjusted to 1 × 105 cells/mL, then the cells were treated with common cultural medium (group A) and osteogenic induced medium containing 0 (group B), 1 × 10-9 (group C), 1 × 10-8 (group D), 1 × 10-7 (group E), 1 × 10-6 (group F), and 1 × 10-5 mol/ L (group G) dexamethasone, respectively. The cell prol iferation and the mRNA expressions of osteocalcin (OC) and core binding factor α1 (Cbfα1) were detected by MTT and RT-PCR, respectively. The activity of alkal ine phosphatase (ALP) was measured, and the percentage of mineral area was calculated. The mineral nodules were also detected by al izarin red staining. Results ADSCs mostly presented fusiform and polygon shape with positive expression of CD44 and negative expression of CD106. The result of oil red O staining was positive after ADSCs treated with adipogenic induced medium. The result of MTT revealed that the absorbance (A) value decl ined with the ascending of the concentration of dexamethasone, and there was significant difference in A value between groups D and E at 5 and 7 days after osteogenic induction (P lt; 0.05). The mRNA expressions of OC and Cbfα1 reached the peak in groups E and D at 7 days after osteogenic induction, respectively. The activity of ALP and the percentage of mineral area had the maximum value in group D at 14 days, then decl ined gradually. There was no significant difference in the mRNA expressions of OC and Cbfα1, the activity of ALP, and the percentage ofmineral area between groups D and E (P gt; 0.05), but significant differences were found between groups D and E and other groups (P lt; 0.05). After 14 days, the cells of group G died, and the result of al izarin red staining was positive in groups B, C, D, E, and F. Conclusion When the concentration of dexamethasone in osteogenic medium is 1 × 10-8 mol/L, it could not only reduce the inhibitive effect on cells prol iferation, but also induce osteogenic differentiation of ADSCs more efficiently.
Objective To investigate the impacts of cytokines （interleukin-4，IL-4；tumor necrosis factor-α，TNF-α） and medications of bronchial asthma （dexamethasone，aminophylline，salbutamol） on the activity of histamine N-methyltransferase（HMT） in tracheal epithelial cells.Methods BEAS-2B bronchial epithelial cells were cultured and treated with different concentration of TNF-α, IL-4, dexamethasone, salbutamol and aminophylline respectively. The activity of HMT in BEAS-2B cells was determined by high performance liquid chromatography.Results The activity of HMT in tracheal epithelial cells was (50±7) pmol?min-1?mg pro-1.TNF-α and IL-4 lowered the activity of HMT significantly at the concentration equal to or higher than 1 ng/mL and 5 ng/mL respectively，and reached the maximum inhibitory effect at the level of 10 ng/mL.Dexamethasone and aminophylline could ameliorate distinctly the inhibitory effect of TNF-α on the activity of HMT, while salbutamol had no significant inhibitory effect.Conclusions TNF-α and IL-4 exert the lowering effect on the activity of HMT，which would be one important cause of airway hyperreactivity.Glucocorticoids and theophyllines are administered to treat asthma partly due to its relieving mechanism of TNF-α negative effects on HMT.
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.
Purpose To evaluate the prostag landins(PG) levels and to identify the effect of dexamethasone(DXM) on PG in response to photochemical insult in rat retina. Methods The experiments were performed on 36 SD rats which were separated into two groups,control and treated groups,and the latter received daily intraperitoneal injections of DXM (1 mg/kg) for 5 consecutive days,starting 3 days before light exposure.The animals were continually exposed to green fluorescent light(510-560 nm)with an illuminance level of (1900plusmn;106.9)lx for 24 hrs.The retinal concentration of PGE 2 and 6-keto-PGF1alpha; were tested at 6hrs,1,3,7 and 14 days after light exposure. Results The PGE2 and 6-keto-PGF1alpha; levels of the control groups (37.50plusmn;2.75,48.06plusmn;4.0 4,81.90plusmn;4.89) pg/mg and (4.68plusmn;0.69,7.50plusmn;0.57,10.40plusmn;0.71) pg/mg had significantly higher values than those of the treated rats(20.60plusmn;4.28,37.36plusmn; 3.34,54.85plusmn;4.57) pg/mg and (2.50plusmn;0.59,4．68plusmn;0.81,6.87plusmn;1.10)pg/mg (Plt;0.01) after 6 hrs,1 and 3 days light exposure respectively. Conclusion By inhibition of PG synthesis,the DXM may play an ameliorative effect on retinal photochemical injury of rats. (Chin J Ocul Fundus Dis,1999,15:94-96)
ObjectiveTo investigate the efficacy and nursing strategy of Comfeel transparent paste in treating peripheral inserted central catheter (PICC)-associated allergic dermatitis. MethodsSixty patients with PICC puncture-associated local allergic dermatitis treated between June 2011 and March 2013 were randomly divided into experimental group and control group with 30 patients in each group. The experimental group was treated with dexamethasone sodium phosphate and Comfeel transparent paste, while the control group was treated with dexamethasone sodium phosphate and 3M transparent dressing. The curative effect was compared between the two methods. ResultsTwelve patients were cured with a curing rate of 40.0% in the control group and 22 patients were cured, and the curing rate was 73.3% in the experimental group. The difference between them was significant (P<0.05). ConclusionTreatment with dexamethasone sodium phosphate and Comfeel transparent paste for PICC-associated allergic dermatitis is quite effective, and the patients felt comfortable with low pains. In addition, it reduces the extubation rate of PICC and improves the care quality.
Objectives To observe the expression of CCL1/CCR8 mRNA in murine lung tissue of bronchial asthma and effects of glucocorticoids on their expression. Methods Thirthy healthy mice were randomly divided into a control group, an asthma group, and a dexamethasone group, with 10 mice in each group. The sensitized murine asthma model was induced by ovalbumin sensitization and challenge, and the dexamethasone group were peritoneally injected with dexamethasone( 2 mg/ kg) . Total and differential cell counts in BALF were measured. IL-4 Level in BALF was evaluated by ELISA. The expression of CCL1 and CCR8 mRNA in the lungs were measured by semi-quantitative RT-PCR. Results The percentage of eosinophils, lymphocyte and IL-4 level in the asthma group increased significantly compared with the controlgroup, and which in the dexamethasone group decreased significantly compared with the asthma group and still higher than the control group( all P lt; 0. 01) . The expression of CCL1 and CCR8 mRNA had the same tendency ( all P lt;0. 01) . Conclusions The gene expression of CCL1/CCR8 is up-regulated in allergic asthma mice.Glucocorticoids can relieve airway inflammation of asthma probably by inhibiting CCL1/CCR8 expression.
ObjectiveTo systematically review the effect of pre-treating the catheters with dexamethasone for preventing PICC-associated phlebitis. MethodsWe electronically searched PubMed, EMbase, The Cochrane Library (Issue 4, 2012), CNKI, CBM, WanFang Data and CQVIP for studies about pre-treating the catheters with dexamethasone to prevent PICC-associated phlebitis from inception to March 2013. Relevant studies including grey literature were also manually searched. Two reviewers independently screened studies according to the inclusion and exclusion criteria, extracted data and evaluated the methodological quality of the included studies. Then meta-analysis was performed using the software RevMan 5.0. ResultsA total of 13 studies involving 1 965 cases (1 025 cases in the dexamethasone group, and 940 cases in the control group) were included. The results of meta-analysis showed that pre-treating the catheters with dexamethasone could significantly decrease the incidence of PICC-associated phlebitis (RR=0.29, 95%CI=0.22 to 0.39, P < 0.000 1). However, no significant difference was found for the PICC-associated other complications, such as pipe blockage, bleeding, swelling of puncture site, allergy and atopic catheter. ConclusionPre-treating the catheters with dexamethasone soltion before inserting could reduce the incidence of PICC-associated phlebitis. The aforementioned conclusion needs to be further validated by more high-quality and large-scale randomized controlled trials.
In 2019, the American Wilderness Medical Society updated and released a new version of the practice guidelines based on the practice guidelines for the prevention and treatment of acute altitude illness first published in 2010 and updated in 2014. This article interprets the guidelines, focusing on effective measures to prevent and treat different forms of acute altitude illness, as well as suggestions for specific methods to manage the disease, with a view to providing help for clinicians in better practice.