ObjectiveTo study the effects of continuous regional arterial infusion (CRAI) of dexamethasone on plasma inflammatory factors of severe acute pancreatitis (SAP) rabbits. MethodsTwentyfour rabbits were randomly divided into sham operation group, SAP group, intravenous infusion of dexamethasone group and CRAI of dexamethasone group (each group 6 rabbits) by random number table. The serum tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-10, and amylase (AMY) levels in rabbits were tested at hour 0.5, 3, 6, 9, and 12 after modeling succeed. The pathological changes of pancreas and the survival were observed on day 3 after modeling succeed. ResultsCompared with the sham operation group, the serum levels of IL-6 significantly increased at 3 h and reached the peak at 6 h, decreased at 9 h (all Plt;0.05); levels of IL-10 significantly increased at 6 h, continuously elevated at 9 h and 12 h (all Plt;0.001); levels of TNF-α significantly increased at 0.5 h (Plt;0.001), reached the peak at 6 h (Plt;0.001) and decreased at 9 h (Plt;0.05); levels of AMY significantly increased at 9 h, continuously elevated at 12 h (all Plt;0.05) in the SAP group. Compared with the SAP group, the serum levels of IL-6 and IL-10 in the CRAI of dexamethasone group all significantly decreased at 6 h, 9 h, and 12 h (Plt;0.001); levels of IL6 significantly decreased only at 6 h in the intravenous infusion of dexamethasone group; levels of TNF-α in the CRAI of dexamethasone group significantly decreased at 3 h, 6 h, 9 h, and 12 h (all Plt;0.001), which in the intravenous infusion of dexamethasone group significantly decreased only at 6 h (Plt;0.05); levels of AMY in the CRAI of dexamethasone group and intravenous infusion of dexamethasone group all significantly decreased at 12 h (Plt;0.05). Compared with the intravenous infusion of dexamethasone group, the serum levels of IL-6 and IL-10 in the CRAI of dexamethasone group all significantly decreased at 6 h (Plt;0.05) and 12 h (Plt;0.001); levels of TNF-α all significantly decreased at 3 h, 6 h, 9 h, and 12 h (all Plt;0.001); levels of AMY were not significantly different (Pgt;0.05). The pathological changes of pancreas in the CRAI of dexamethasone group were obvious, the death of rabbits reduced on day 3 after modeling succeed. ConclusionCRAI dexamethasone can effectively reduce the systemic inflammatory response and pancreatic inflammation, and reduce mortality.
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 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 role of IFN-γ in suppressing bleomycin-induced pulmonary fibrosis in rats.Methods Seventy-five SD rats were randomly divided into five groups (15 rats in each group)，ie.a normal group，a bleomycin-induced pulmonary fibrosis model group，a dexamethasone-treated group，a high-dose IFN-γ-treated group (150 000 U/kg) and a low-dose IFN-γ-treated group (50 000 U/kg).Five rats in each group were randomly killed in 7th day，14th day and 28th day after relative treatment respectively，and lung tissue samples were harvested for histopathology study.HE and Masson staining were used to determine the extent of alveolus inflammation and pulmonary fibrosis respectively.Histoimmunochemical method were adapted to determine protein levels of TGF-β1，CTGF，type Ⅰcollagen and type Ⅲ collagen in pulmonary tissues.Results Histopathological study showed that treatment with either dexamethasone or IFN-γ (both high dose and low dose) remarkably meliorated the extent of alveolus inflammation and suppressed pulmonary fibrosis (compared with model group，all Plt;0.05).Histoimmunochemical study suggested that both dexamethasone and IFN-γ could inhibit the expression of TGF-β1，CTGF，type Ⅰand type Ⅲ collagen (compared with model group，all Plt;0.05)，and the suppression of TGF-β1，type Ⅰand type Ⅲ collagen expression was more obvious in high-dose IFN-γ-treated group than those in low-dose group (Plt;0.05).Conclusions INF-γ possesses apparent anti-fibrosis effect that is similar to dexamethasone but with less side effect.Such effect may resulted from reduced production of type Ⅰand type Ⅲ collagen through expression inhibition of cytokines such as TGF-β1 and CTGF.
Objective To investigate the expression of aquaporin-1( AQP1 ) in visceral and parietal pleura in SD rats and to examine the effect of AQP1 on pleural fluid turnover. Methods Five groups( n = 24 ) of SD rats were randomly assigned to received intrapleural injection of dexamethasone,lipopolysaccharide, erythromycin, hypertonic saline and normal saline, respectively. The AQP1 protein in pleural was detected with immunohistochemistry. The mRNA expression of AQP1 under stimulations at different time points was measured by real time RT-PCR. Results AQP1 was immunolocalized predominantly to the microvessels and mesothelial cells of visceral and parietal pleura. The extent of AQP1expression in parietal pleura was less than that in visceral pleura[ ( 4. 14 ±1. 12) ×104 copy /μg vs ( 7. 43 ±2. 02) ×104 copy / μg, P lt;0. 05] . AQP1 expression increased at all phases in the dexamethasone group andthe hypertonic saline group, whereas decreased in the erythromycin group and the lipopolysaccharide group.Conclusion The stimulations of dexamethasone, lipopolysaccharide, erythromycin and hypertonic saline can significantly change the AQP1 expression in pleura, which indicate that AQP1 may contribute to the accumulation and clearance of pleuritic fluids.
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.
Objective Corticosteroids can destroy the cartilage. To investigate the effect of dexamethasone (Dexa) on the apoptosis and expression of Fas/FasL of human articular chondrocytes (HACs) in vitro so as to explore the mechanism ofpro-apoptotic role of Dexa on HACs. Methods Following full agreement of patients, the cartilage specimens were collectedfrom the patients with osteoarthritis undergoing knee replacement. The second passage HACs were incubated in cell culture media containing 0.125, 1.25, 12.5, 25, and 50 μg/mL Dexa for 48 hours respectively to determine the optimal concentration of Dexa by MTT. The apoptosis was assessed by TMRE/Hoechst/Annexin V-FITC/7-AAD quadruple staining after culture for 0, 24, and 48 hours. The mRNA expressions of Fas and FasL were determined by real-time quantitative PCR after culture for 48 hours. The protein expressions of Fas and FasL were determined by immunohistochemistry staining analysis after culture for 24 hours and 48 hours. Results The cell inhibitory rate of 25 μg/mL Dexa was significantly higher than that of 50 μg/mL Dexa (P lt; 0.05), and there were significant differences when compared with that at other concentrations of Dexa (P lt; 0.05), so 25 μg/mL Dexa was appropriately selected as an optimal concentration of Dexa. The apoptotic rates of HACs were 5.8% ± 0.3%, 27.0% ± 2.6%, and 36.0% ± 3.1% at 0, 24, and 48 hours, respectively, in a time dependent manner (P lt; 0.05). The expressions of Fas mRNA were (8.93 ± 1.12) × 10—3 in the experimental group and (3.31 ± 0.37) × 10—3 in the control group, showing significant difference (P lt; 0.05). The expressions of FasL mRNA were (5.92 ± 0.66) × 10—3 in the experimental group and (2.31 ± 0.35) × 10—3in the control group, showing significant difference (P lt; 0.05). The expressions of Fas and FasL proteins showed an increasing tendency with time in the experimental group and the expressions were significantly higher than those in the control group after culture for 24 hours and 48 hours (P lt; 0.05). Conclusion Dexa can induce the apoptosis and significantly upregulate the apoptotic gene expression of Fas/FasL, which can provide the experimental evidence to further investigate the role of Fas/FasL signaling pathway in Dexa-induced HACs apoptosis.
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 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.
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.