BACKGROUND: There are many species of ceramic bonding systems supplied in market, the mechanical strength is aprerequisite condition for resin cement in clinical use.OBJECTIVE: To study the difference of mechanical strength between Panavia F resin cement and self-made resin cement,DESIGN, TIME AND SETTING: A controlled observational study was performed in the prosthesis laboratory of the FourthMilitary Medical University of Chinese PLA between May 2006 and March 2007.MATERIALS: Panavia F resin cement was sourced from KURARAY MEDICAL INC. (Japan), experimental resin cement wasproduced by College of Stomatological Medicine in the Fourth Military Medical University of Chinese PLA.METHODS: Five cylindrical compressive strength specimens at an 8-mm height and 4-mm diameter were prepared, as well as5 cylindrical diametral tensile strength specimens at a 3-mm height and 6-mm diameter. AGS-500 universal material testingmachine was applied to detect the compressive strength and diametral tensile strength.MAIN OUTCOME MEASURES: The diametral tensile strength test and compressive strength test of the specimens.RESULTS: The compressive strength of Panavia F resin cement was remarkably higher than that of experimental cement[(238.92±24.54), (149.08±12.13) M Pa, P ＜ 0.05]. There were no significances between two resin cements on diametral tensilestrength (P＞ 0.05).CONCLUSION: There were no significance between two resin cements on diametral tensile strength following completecuring. The compressive strength of experimental resin cement can reach the standard of ADA (＞ 70 MPa) although it is lowerthan the compressive strength of Panavia F resin cement.

Objective To observe the expression of the unfolded protein response especially the inositol-requiring enzyme-1 (IREl)-Xbp1 signaling pathway, and the change trend of osteogenic markers after inhibition of IREl expression through siRNA interference in osteoblasts exposed to fluoride. Methods Proliferation activity of MC3T3-E1 cells was detected by CCK-8 assay, and 0.0, 0.1, 1.0, 2.0, 8.0, 16.0, 20.0, 32.0, 64.0 mg/L groups were set up. Then representative doses of low, medium and high fluoride (2.0, 8.0, 20.0 mg/L) were selected to treat MC3T3-E1 cells and the expression of the unfolded protein response related genes and osteogenic markers [alkaline phosphatase (ALP), osteocalcin (OCN), Runx2, osterix, binding immunoglobulin protein (Bip), protein kinase-like endoplasmin reticulum kinase ( PERK ) , activated transcription factor 6 (ATF6), Xbp1] was detected by Real-time PCR. MC3T3-E1 cells were transfected with IRE1 siRNA and then exposed to fluoride, and the expression of IRE1 signaling pathway and osteogenic markers was detected by Western blotting and real-time PCR. Results CCK-8 results showed the bidirectional effect of fluoride on the activity of osteoblasts. Compared with the 0.0 mg/L group [1.00 ± 0.01 (d 1), 1.00 ± 0.02 (d 3), 1.00 ± 0.08 (d 7)], the osteoblast activity was significantly enhanced at 2.0 mg/L [1.11 ± 0.02 (d 1), 1.29 ± 0.02 (d 3)], 8.0 mg/L [1.16 ± 0.02 (d 1), 1.44 ± 0.03 (d 3), all P<0.05], while 20.0 mg/L inhibited cell activity [0.83 ± 0.01 (d 1), 0.81 ± 0.01 (d 3), 0.96 ± 0.04 (d 7), all P< 0.05]. Compared with the 0.0 mg/L group [6.86 ± 2.13 (ALP), 4.58 ± 1.52 (OCN), 2.65 ± 0.38 (Runx2), 12.48 ± 3.96 (osterix)], 2.0 mg/L significantly induced the expression of intracellular ALP (12.80 ± 3.62), Runx2 (6.61 ± 0.48) and osterix (21.42 ± 1.56), and the differences were statistically significant (all P< 0.05), while 20.0 mg/L inhibited the expression of ALP (0.88 ± 0.17), OCN (0.16 ± 0.05) and osterix (1.35 ± 0.51), and the differences were statistically significant (all P<0.05). Compared with the 0.0 mg/L group [1.36 ± 0.58 (IRE1), 0.96 ± 0.45 (Xbp1)], the expression of endoplasmic reticulum stress related genes IRE1 [14.84 ± 2.57 (2.0 mg/L), 4.10 ± 0.52 (8.0 mg/L), 5.30 ± 0.63 (20.0 mg/L)] and Xbp1 [2.62 ± 0.66 (2.0 mg/L), 1.97 ± 0.47 (20.0 mg/L)] were significantly increased in the corresponding fluoride groups (all P<0.05). After IRE1 gene knockout, compared with the control group [gene:3.25 ± 0.48 (OCN), 5.62 ± 1.86 (Runx2), 2.67 ± 0.35 (ALP); protein: 0.16 ± 0.03 (OCN), 0.34 ± 0.27 (ALP)], the gene expression of OCN [0.63 ± 0.46 (2.0 mg/L), 0.81 ± 0.36 (8.0 mg/L), 0.62 ± 0.31 (20.0 mg/L)], Runx2 [0.18 ± 0.03 (2.0 mg/L), 0.12 ± 0.01 (8.0 mg/L), 1.09 ± 0.33 (20.0 mg/L)] and ALP [1.01 ± 0.12 (8.0 mg/L), 0.38 ± 0.09 (20.0 mg/L)] in the corresponding fluoride groups were significantly decreased (all P < 0.05), protein expression of OCN [0.06 ± 0.02 (2.0 mg/L), 0.06 ± 0.02 (8.0 mg/L), 0.07 ± 0.03 (20.0 mg/L)], and ALP [0.02 ± 0.01 (8.0 mg/L), 0 (20.0 mg/L)] were significantly decreased (all P< 0.05). Conclusion Unfolded protein response is observed under different doses of fluoride in osteoblasts, and IRE1 gene knockout has inhibited the expression of ALP, OCN, osterix and Runx2 in osteoblasts induced by fluoride, which suggests that IRE1 signaling pathway may play a key role in the differentiation of osteoblasts exposed to fluoride.

Objective To compare the effect of high volume continuous blood purification (CBP) with routine CBP on multiple organ dysfunction syndrome(MODS).Methods 38 patients with MODS were randomly divided into high volume CBP group( treatment group,18 cases) and routine CBP group (control group,20 cases).And they were respectively detected on mean arterial pressure(MAP),dosage of Dopamine,PaO2/FiO2,APACHE [ score,lactic acid,length of stay and mortality in ICU post-treatment 24h and 48h.Results Compared with control group,MAP and PaO2/FiO2 on treatment group were more higher( P ＜ 0.05 ),while dosage of Dopamine,APACHE Ⅱ score,lactic acid were significantly shorter than these of treatment group( P ＜ 0.05 ),and length of stay and mortality in ICU were significantly lower than those of treatmen group [ ( 8.54 ± 4.15 ) d vs ( 11.82 ± 5.76) d,P ＜ 0.05:22.2％ vs 35.0％,P ＜0.05 ].Conclusion High volume CBP could reduce the mortality in ICU compared with control group routine CBP.

Objective To investigate the regulatory effects of glucocorticoids on the local renin-angiotensin system in osteoblasts by using MC3T3-E1 cells.Methods Cellular immune histochemistry was carried out to observe the renin-angiotensin system in osteoblasts.And then after 12-hour culture in serum-free solution,MC3T3-E1 cells were divided into four groups:control,dexamethasone (DXM),dexamethasone + mifepristone (DXM+MIF)and mifepristone (MIF).Components of the renin-angiotensin system including angiotensin type 1 receptor (AT1R),angiotensin type 2 receptor (AT2R)and angiotensin converting enzyme (ACE)in osteoblasts were detected at the mRNA and protein levels using Western blot and PCR.The activity of ACE was also measured after 36-hour intervention.Results The results of immunohistochemistry showed that AT1R,AT2R and ACE were all expressed in osteoblasts.The activity of ACE increased obviously after dexamethasone intervention compared with that in the control group,which was blocked by mifepristone.The mRNA levels of AT1R,AT2R and ACE were increased by dexamethasone compared with those in the control group,which was inhibited by mifepristone.The protein levels of AT1R,AT2R and ACE were enhanced by dexamethasone compared with those in the control group, which was blocked when the cells were co-intervened with mifepristone.However,ACE activity and the mRNA and protein levels of AT1R,AT2R and ACE did not change when the cells were intervened with mifepristone alone (P>0.05).Conclusion The local renin-angiotensin system in osteoblasts is activated by dexamethasone through glucocorticoid receptors on osteoblasts,which may be one of the pathogenesis of glucocorticoid-induced osteoporosis.

BACKGROUND: Irradiation therapy in the cancer patients after surgery may have negative effects on implant fixation. OBJECTIVE: To observe the effects of 60Co irradiation and trace element zinc on fixation strengths of titanium implant. METHODS: Thirty-six adult male rabbits were involved. One piece of titanium implant was separately placed into the bilateral proximal tibial heads in rabbits to set up animal models of titanium implants. The animals were randomly divided into control group, zinc supplement group, 60Co irradiation group and 60Co irradiation and zinc supplement group. Zinc sulfate of 10 g/L was administered intramuscularly to animals in the zinc supplement group at the dose of 4 mg/kg once per day, and those in the control group were treated with saline at the same dose. The animals in the 60Co irradiation group received 60Co irradiation at the dose of 45 Gy and saline by intramuscular injection. Those in the 60Co irradiation and zinc supplement group received 60Co irradiation and zinc sulfate. The animals were killed at 1, 4 and 12 weeks after treatment. The fixation strengths were measured and compared among groups. RESULTS AND CONCLUSION: (1) Zinc supplement made the titanium implants have higher fixation strengths, and reach a high level at 4 weeks after surgery. (2) 60Co irradiation significantly inhibited the fixation strengths of the implants. After 60Co radiation, zinc supplement stil could promote fixation strengths of titanium implants. (3) It is indicated that amount of zinc supplement after irradiation therapy can al eviate the negative effects of irradiation on implant fixation.

OBJECTIVESTo assess surgical treatment of lumbar spinal stenosis associated with unstable degenerative spondylolisthesis.

METHODSIn 86 patients with lumbar spinal stenosis associated with unstable degenerative spondylolisthesis. (30 men and 56 women, aged from 30 to 77 years), 63 patients complained of lower back pain with both lower extremity pain, 10 patients pain in one leg, and 13 patients only lower back pain. Seventy-two of these patients complained of intermittent claudication, with a walking distance ranging from 10 to 1 000 m. Thirty-two patients had some changes in sensation, motion and reflexes of the foot. According to White' critera, all patients showed dynamic instability of the lesion. Meyerding criteria showed degree 1 in 79 patients, and degree 2 in 7. CT scan was made in 56 patients, MRI in 24 and MRM in 6 before operation. Myelography was performed in 61 patients, and CTM in 6. Stenosis and spondylolisthesis located between L(4) and L(5) in 49 patients, between L(3) and L(4) in 6, between L(5) and S(1) in 25, between L(3) and L(4) and between L(4) and L(5) in 2, and from L(3) to S(1) in 4. The patients with pathological spondylolisthesis were excluded. Lateral recess stenosis of one leg was observed in 10 patients, lateral recess of both legs in 22, and central canal stenosis in 54, of whom 12 patients were associated with protrusion of the lumbar disc. Decompression and autograft with iliac bone and various internal fixation were performed in all patients.

RESULTSThe patients were followed up from 8 months to 13 years, longer than 1 year (average 5.6 years) in 81 patients. According to Amundsen et al, excellent results were obtained in 78 patients, good in 5, and fair in 3. Spondylolisthesis was completely reduced in 70 patients of degree 1 (89.9%), and in 6 patients of degree 2 (85.7%). No patient showed slippage aggravated. 74 patients gained bone graft fusion within 3 months and 10 patients within 6 months. Two patients showed pseudoarthrosis during the follow-up. Complications included internal fixation breakage in 1 patient, and delayed infection in 1.

CONCLUSIONSComplete decompression and bone graft fusion are the key to treatment. Decompression and internal fixation improve the symptoms of patients with lumbar spinal stenosis associated with spondylolisthesis. Transpedicle instrumentation can reduce spondylolisthesis and maintain the physical curve of the lumbar.

Adult ; Aged ; Decompression, Surgical ; methods ; Female ; Humans ; Lumbar Vertebrae ; Male ; Middle Aged ; Retrospective Studies ; Spinal Stenosis ; complications ; surgery ; Spondylolisthesis ; surgery

The 13th World Congress of the International Hepato-Pancreato-Biliary Association was held from 4th to 7th September 2018 in Geneva,Switzerland.Thousands of wellknown specialists and scholars from 96 countries around the world were invited for the great event.The congress aimed to explore the latest achievements of diagnosis and treatment of hepatobiliary and pancreatic diseases from both the clinical and basic perspective.In this article,authors reviewed and analyzed the up-to-date research information and combined clinical researches of the author team,in order to share the experience and achievements in the field of hepato-pancreato-biliary surgery with colleagues and provide new information and inference for optimization of diagnosis and treatment in this field.

Objective To measure the abdominal muscle composition of maintenance dialysis patients using quantitative computed tomography(QCT)and to analyze its relationship with abdominal aortic calcification(AAC).Methods The abdominal CT data of 193 maintenance dialysis patients were analyzed retrospectively and their clinical data were collected.The abdominal muscle composi-tion,including muscle area and muscle fat area,was measured at the middle level of L3 vertebral by QCT.The abdominal aortic calcifica-tion scores(AACs)were calculated using the Agatston method.The groups were grouped according to the quartiles of AACs,and differences in muscle area,muscle fat area and their associated variables were compared between the four groups.The relationship between abdominal muscle composition and AAC was assessed using Spearman rank correlation analysis and partial correlation analysis.Results AACs were positively correlated with age,male,dialysis age,diabetes,hypertension,and abdominal muscle fat area(r=0.555,0.172,0.192,0.348,0.335,0.358,all P<0.05),while no significant correlation was found with abdominal muscle area.A partial correlation analysis controlling for age,sex,dialysis age,hypertension and diabetes showed that AACs were still positively correlated with abdominal muscle fat area(r=0.183,P=0.012).Conclusion Abdominal muscle fat area in maintenance dialysis patients is positively associ-ated with the degree of AAC,and high abdominal muscle fat area is a risk factor for AAC.Enhanced muscle exercise may prevent the risk of vascular calcification in dialysis patients.