Dynamic analysis of lathe bed of woodworking CNC machining center based on the modeling of joint surface.

Based on the finite element theory, a joint-plane modeling method is employed to connect the corresponding nodes at the joint surface of the woodworking computer numerical control (CNC) machining center bed with a 2-node 12-degree-of-freedom unit. A spatial element model is established, which can show the state of the nodes between joint surfaces when they are stretched, compressed, or twisted; and it can help build a woodworking CNC machining center on a finite element model of bed with the characteristics of the joint surface. The simulated analysis is performed on the model and is compared with the result of simulated analysis on the bed model that ignores the characteristics of the joint surface and modal experiment. The comparison verifies the effectiveness of the modeling method based on the characteristics of the joint surface. The weak link of the machine bed structure is analyzed and optimized. The natural frequency of the bed is improved by2.55% ~ 11.3%. The displacement is reduced by a maximum of 19.4%, and dynamic performance of the bed is improved.

Role of intraoperative patients positioning in endoscopic full-thickness resection of large gastric tumors under general anesthesia.

Full thickness endoscopic resection of large submucosal gastric tumors (>3 cm) is a big challenge for endoscopists. Issues include how to efficiently resect the lesion, obtain homeostasis, and suture the defect. There are no guidelines regarding the importance of patient position on the success of endoscopic resections in anesthetized patients. Typically, the patient is placed in left lateral position for the endoscopic therapy and during the procedure patient's position is changed to maintain the tumor above the gastric fluids to prevent gastric juices and tumor or tumor fragments from falling into the peritoneal cavity in the event of perforation. This study emphasized the importance of planning the procedure to ensure that the patient's position and anesthetist's concerns are met and allow optimal access to the lesion for endoscopic resection. Prior to sedation the patient should be positioned so that the tumor is in the up position which also prevents blood obscuring the operative field, helps detect bleeding points for immediately hemostasis. In addition, due to gravitational effect, the resected tumor will fall into the gastric cavity exposing the root of the tumor making resection easier and reduce procedure time. Preplanning avoids unnecessary readjustment of positioning and improves the ease and safety of the procedure.

Laparoscopic management or laparoscopy combined with transvaginal management of type II cesarean scar pregnancy.

OBJECTIVE: To evaluate the clinical effectiveness of laparoscopic management of cesarean scar pregnancy (CSP) by deep implantation. BACKGROUND: A pregnancy implanting within the scar from a previous cesarean delivery is a rare condition of ectopic pregnancy. There are two different types of CSPs. Type I is caused by implantation of the amniotic sac on the scar with progression toward either the cervicoisthmic space or the uterine cavity. Type II (CSP-II) is caused by deep implantation into a previous CS defect with infiltrating growth into the uterine myometrium and bulging from the uterine serosal surface, which may result in uterine rupture and severe bleeding during the first trimester of pregnancy. Thus, timely management with an early and accurate diagnosis of CSP-II is important. However, laparoscopic management in CSP-II has not yet been evaluated. METHODS: Eleven patients with CSP-II underwent conservative laparoscopic surgery or laparoscopy combined with transvaginal bilateral uterine artery ligation and resection of the scar with gestational tissue and wound repair to preserve the uterus from March 2008 to November 2011. Patients with CSP-II were diagnosed using color Doppler sonography, and the diagnosis was confirmed by laparoscopy. The operation time, the blood loss during surgery, the levels of ß-human chorionic gonadotropin (ß-hCG) before surgery, the time taken for serum ß-hCG levels to return to <100 mIU/mL postoperatively, and the time for the uterine body to revert to its original state were retrospectively analyzed. RESULTS: All 11 operations were successfully performed using laparoscopy with preservation of the uterus. One patient underwent a dilation and curettage after laparoscopic bilateral uterine artery ligation. Eight patients were treated solely by laparoscopic bilateral uterine artery ligation and resection of the scar with gestational tissue and wound repair. The remaining two patients underwent laparoscopic bilateral uterine artery ligation and transvaginal resection of the CS with gestational tissue and wound repair because of dense adhesions and heavy bleeding. The average operation time was 85.5 (±17.5) minutes, and the blood loss was 250.0 (±221.4) mL. The blood serum level of ß-hCG returned to <100 mIU/mL in 16.4 (±5.3) days postoperatively. Among the 10 patients who underwent resection of CS and wound repair, the time for the uterus to revert to its original state (judged by ultra-sonography) was 10.8 (±3.0) days postoperatively. CONCLUSIONS: Laparoscopy can remove ectopic gestational tissue and allow subsequent wound repair, as well as provide diagnostic confirmation. Being a minimally invasive procedure, laparoscopic or laparoscopy combined with transvaginal bilateral uterine artery ligation and resection of the scar with gestational tissue and wound repair can become an effective alternative for the treatment of CSP-II.

Anti-inflammatory role of cannabidiol and O-1602 in cerulein-induced acute pancreatitis in mice.

OBJECTIVES: The anti-inflammatory effects of O-1602 and cannabidiol (CBD), the ligands of G protein-coupled receptor 55 (GPR55), on experimental acute pancreatitis (AP) were investigated. METHODS: Acute pancreatitis was induced in C57BL mice by intraperitoneal injection of 50 µg/kg cerulein hourly, with a total of 6 times. Drugs (O-1602, 10 mg/kg, or CBD, 0.5 mg/kg) were given by intraperitoneal injection 2 times at 30 minutes before the first injection and immediately before the fifth cerulein injection. At 3 hours after the last injection, the blood, the lungs, and the pancreas were harvested for the pancreatic enzyme activity, myeloperoxidase activity, and pro-inflammatory cytokines measurement; and the expressions of GPR55 mRNA and protein in the pancreas were detected. RESULTS: Cannabidiol or O-1602 treatment significantly improved the pathological changes of mice with AP and decreased the enzyme activities, IL-6 and tumor necrosis factor α; levels, and the myeloperoxidase activities in plasma and in the organ tissues. G protein-coupled receptor 55 mRNA and protein expressed in the pancreatic tissue, and the expressions were decreased in the mice with AP, and either CBD or O-1602 attenuated these changes to a certain extent. CONCLUSION: Cannabidiol and O-1602 showed anti-inflammatory effects in mice with AP and improved the expression of GPR55 in the pancreatic tissue as well.

Down-regulation of HSP60 expression by RNAi increases lipopolysaccharide- and cerulein-induced damages on isolated rat pancreatic tissues.

The objective of this study was to investigate the function of heat shock protein 60 (HSP60) on pancreatic tissues by applying HSP60 small interfering RNA (siRNA) to reduce HSP60 expression. Rat pancreas was isolated and pancreatic tissue snips were prepared, cultured, and stimulated with low and high concentrations of cerulein (10(-11) and 10(-5) mol/L) or lipopolysaccharide (LPS, 10 and 20 µg/mL). Before the stimulation and 1 and 4 h after the stimulation, the viability and the level of trypsinogen activation peptide (TAP) in the tissue fragments were determined and the levels of tumor necrosis factor-alpha (TNF-α) and interleukin 6 (IL-6) in the culture supernatants were measured. Real-time PCR and Western blotting were used to evaluate the HSP60 mRNA and protein expression. After the administration of siRNA to inhibit HSP60 expression in the isolated tissues, these injury parameters were measured and compared. The pancreatic tissues in the control (mock-interfering) group showed a decreased viability to varying degrees after being stimulated with cerulein or LPS, and the levels of TAP, TNF-α, and IL-6 increased significantly (p < 0.05) in the tissues and/or in the culture supernatant. The expressions of HSP60 mRNA and protein were raised moderately after stimulating 1 h with low concentrations of cerulein or LPS, but decreased with high concentrations of the toxicants. In particular, the expression of HSP60 protein was reduced significantly (p < 0.05) when the tissues were stimulated by the two toxicants for 4 h. In contrast, the tissue fragments in which HSP60 siRNA was applied showed much lower tissue viability (p < 0.01) and higher levels of TNF-a, IL-6, and TAP (p < 0.01) in the tissues or culture supernatant after stimulating with the toxicants at the same dose and for the same time duration as compared with those of the control groups (p < 0.05). The results indicated that both cerulein and LPS can induce injuries on isolated pancreatic tissues, but the induction effects are dependent on the duration of the stimulation and on the concentrations of the toxicants. HSP60 siRNA reduces HSP60 expression and worsens the cerulein- or LPS-induced injuries on isolated pancreatic tissues, suggesting that HSP60 has a protective effect on pancreatic tissues against these toxicants.

[Outcome and relevant factors of tubal pregnancy treated with laparoscopic conservative surgery].

OBJECTIVE: To investigate the therapeutic outcome and its influencing factors after laparoscopic conservative surgery in treatment of tubal pregnancy. METHODS: From January 2003 to December 2008, 226 cases with tubal pregnancy were treated by laparoscopic conservative surgery. The tubal patency was evaluated in 152 cases given by hysterosalpingography (HSG) and 6 cases given by second laparoscopic exploration at 3 - 6 months after surgery. In their first laparoscopic surgeries, 209 got successful treatment and 19 underwent fail treatment. At 3 - 6 months after surgery, 89 cases with tubal patency among 207 cases with successful treatment were enrolled in group A. Nineteen cases who were failed in their first laparoscopic conservative surgery and treated by salpingectomy and 63 cases with tubal obstruction were enrolled in group B. The rate of tubal patency was calculated on patients with characteristics of gestational sac less or more than 5 cm, the level serum human chorionic gonadotropin (hCG) less than 2000 IU/L, 2000 IU/L to 5000 IU/L, and more than 5000 IU/L. RESULTS: There was no significant difference in age, parity, amenorrhea, location of tubal pregnancy, rupture, pelvic adhesion between group A and group B. Two hundred and seven cases (91.6%, 207/226) were successfully treated at initial laparoscopy. One hundred and fifty-two cases got follow up and 55 cases lost follow up at 3 to 6 months after surgery. There was statistical difference in preoperative hCG value which median were 980 (55 - 12 000) IU/L in group A, 3150 (570 - 40 000) IU/L in group B (P < 0.01); the diameter of tubal gestational sac were (3.4 +/- 1.3) cm in group A and (5.0 +/- 1.7) cm in group B (P < 0.01); respectively, the volume of peritoneal bleeding were 200 (0 - 1500) ml and 300 (0 - 1600) ml, the rate of live tubal embryo was 2% (2/89) in group A and 11% (9/82) in group B, which all reached statistical difference (P < 0.05). Among 171 cases in both group A and B, the rate of tubal patency were 65% (67/103) in 103 cases with maximal diameter of tubal gestational sac less than 5 cm and 32% (22/68) in 68 cases with maximal diameter of tubal gestational sac more than 5 cm, which reached statistical difference (P < 0.01). The rate were 72% (73/102) in patients with serum level of hCG less than 2000 IU/L, 29% (12/42) in patients with 2000 IU/L to 5000 IU/L and 15% (4/27) in patients with more than 5000 IU/L, which also showed statistical difference (P < 0.05). It was observed that preoperative serum hCG level (OR = 0.277, P < 0.01), the maximal diameter of gestational sac (OR = 0.577, P < 0.01) and the volume of peritoneal bleeding (OR = 0.999, P < 0.05) were significant factors influencing successful laparoscopy treatment by logistical regression analysis. CONCLUSION: In order to preserve fertility, laparoscopic conservative surgery was a safe and feasible approach in treatment of tubal pregnancy. Preoperative serum hCG levels, size of tube gestational sac were significant factors influencing successful laparoscopic surgery.

Ascitic fluid and serum from rats with acute pancreatitis injure rat pancreatic tissues and alter the expression of heat shock protein 60.

Acute pancreatitis (AP) is an inflammatory process in which cytokines and chemokines are involved. After onset, extrapancreatic stimuli can induce the expression of cytokines in pancreatic acinar cells, thereby amplifying this inflammatory loop. To further determine the role and mechanism of irritating agents in the pathogenesis of AP, rat pancreatic tissues were stimulated with ascitic fluid (APa) and serum (APs) from rats with AP or with lipopolysaccharide (LPS). In addition, the alteration of heat shock protein 60 (HSP60) expression was evaluated. Rat pancreas was removed and meticulously snipped to fragments. The snips were cultured for up to 48 h. During this period, the tissue viability as well as amylase and TNF-alpha levels in the supernatant and the HSP60 expression in the pancreatic tissue before and after stimulation by APa, APs, and LPS were assayed time-dependently. At different time-points during the culture, the viability and the amylase activity in the pancreatic tissue remained largely stable. After stimulation with APa, APs, or LPS for 1 h, the pancreatic tissues showed some damage, and this was followed by a sharp decrease in the viability accompanied by increased levels of amylase and TNF-alpha in the culture medium 2 or 4 h after stimulation (p < 0.05). In contrast, both the HSP60 mRNA and protein levels had a relatively high expression in the freshly prepared tissue fragments (0 h). As the culturing period was extended, the expression of HSP60 mRNA decreased only slightly; at the same time, the HSP60 protein levels decreased over a prolonged culture time, significantly so from 12 through 48 h (p < 0.05). After stimulation with APs, APa, or LPS, both the expression of HSP60 mRNA and protein in the tissue fragments increased slightly at 1 h and decreased significantly thereafter at 2 and 4 h (p < 0.05). APa, APs, or LPS induce injuries on isolated pancreatic tissues, accompanied by an altered HSP60 expression pattern in a time-dependent manner.

Intervention of pyrrolidine dithiocarbamate and tetrandrine on cellular calcium overload of pancreatic acinar cells induced by serum and ascitic fluid from rats with acute pancreatitis.

BACKGROUND AND AIM: To investigate the effects of serum and ascitic fluid from rats with acute pancreatitis (AP) on cellular free calcium concentration ([Ca(2+)]i) of isolated rat pancreatic acinar cells, and the intervention of pyrrolidine dithiocarbamate (PDTC) and tetrandrine (Tet) to cellular calcium overload in AP. METHODS: AP was induced in Sprague-Dawley rats with a retrograde pancreatic duct injection of 3% sodium deoxycholate, and confirmed by histopathological examination and amylase activity assay. The rat serum and ascitic fluid were collected at 1, 5 and 10 h after AP induction, and used as irritants on isolated rat pancreatic acinar cells. The effects on intracellular [Ca(2+)]i, and cell viability were examined. Then, the antagonistic effects of different concentrations of PDTC and Tet were assessed. RESULTS: The irritation with AP serum and ascitic fluid reduced the survival rate of the isolated rat pancreatic acinar cells and increased the cellular [Ca(2+)]i significantly (P < 0.05). As AP induction course prolonged, the stimulation effect of the AP serum and ascitic fluid intensified. In the pretreated acinar cells with PDTC or Tet, the decreased cell vitality reverted. The elevation of [Ca(2+)]i in the acinar cells significantly ameliorated (significant, P < 0.05; very significant, P < 0.01). CONCLUSION: The serum and ascitic fluid from AP rats drastically elevate the [Ca(2+)]i in isolated pancreatic acinar cells and decrease cell vitality, while the pretreatment of cells with PDTC and Tet offsets the calcium overload irritated by the AP serum and ascitic fluid and protects these isolated acinar cells.

Alteration of Cpn60 expression in pancreatic tissue of rats with acute pancreatitis.

The expression of heat-shock protein 60 (also known as chaperonin 60, Cpn60) in experimental acute pancreatitis (AP) is considered to play an active role in the prevention of abnormal enzyme accumulation and activation in pancreatic acinar cells. However, there are controversial results in the literature regarding the relationship between the abnormality of Cpn60 expression and AP onset and development. The purpose of this study was to investigate the alternations of Cpn60 expression and the relationship between the abnormal expression of Cpn60 and AP progression in rat severe acute pancreatitis (SAP) models. In this report, we induced SAP in Sprague-Dawley (SD) rats by reverse injection of sodium deoxycholate into the pancreatic duct, and examined the dynamic changes of Cpn60 expression in pancreatic tissues from different time points and at different levels with techniques of real-time PCR, western blotting, and immunohistochemistry. At 1 h after SAP induction, the expression of Cpn60 mRNA in the AP pancreatic tissues was higher than those in the sham-operation group and normal control group, but decreased sharply as the time period was extended, and there was a significant difference between 1 h and 10 h after SAP induction (p < 0.05). In the AP process, Cpn60 protein expression showed transient elevation as well, and the increased protein expression occurred predominantly in affected, but not totally destroyed, pancreatic acinar cells. As AP progressed, the pancreatic tissues were seriously damaged, leading to a decreased overall Cpn60 protein expression. Our results show a complex pattern of Cpn60 expression in pancreatic tissues of SAP rats, and the causality between the damage of pancreatic tissues and the decrease of Cpn60 level needs to be investigated further.

Voltage-gated potassium channel Kv1.3 in rabbit ciliary epithelium regulates the membrane potential via coupling intracellular calcium.

BACKGROUND: The cell layer of the ciliary epithelium is responsible for aqueous humor secretion and maintenance. Ion channels play an important role in these processes. The main aim of this study was to determine whether the well-characterized members of the Kv1 family (Kv1.3) contribute to the Kv currents in ciliary epithelium. METHODS: New Zealand White rabbits were maintained in a 12 hours light/dark cycle. Ciliary epithelium samples were isolated from the rabbits. We used Western blotting and immunocytochemistry to identify the expression and location of a voltage-gated potassium channel Kv1.3 in ciliary body epithelium. Membrane potential change after adding of Kv1.3 inhibitor margatoxin (MgTX) was observed with a fluorescence method. RESULTS: Western blotting and immunocytochemical studies showed that the Kv1.3 protein expressed in pigment ciliary epithelium and nonpigment ciliary epithelium, however it seemed to express more in the apical membrane of the nonpigmented epithelial cells. One nmol/L margatoxin, a specific inhibitor of Kv1.3 channels caused depolarization of the cultured nonpigmented epithelium (NPE) membrane potential. The cytosolic calcium increased after NPE cell depolarization, this increase of cytosolic calcium was partially blocked by 12.5 micromol/L dantrolene and 10 micromol/L nifedipine. These observations suggest that Kv1.3 channels modulate ciliary epithelium potential and effect calcium dependent mechanisms. CONCLUSION: Kv1.3 channels contribute to K+ efflux at the membrane of rabbit ciliary epithelium.

[Quantitative use of fluorescence in situ hybridization to detect syntrophic acetogenic bacteria in anaerobic environmental samples].

Syntrophic acetogenic bacteria, an important functional one in anaerobic habitats, were detected and counted by fluorescence in situ hybridization (FISH) technology by using 16S rRNA-based oligonucleotide probes. For enumeration and quantification of the targeted bacteria, an attempt was made to optimize the hybridization conditions. The optimum conditions are as follows: a fixation time of 19h, a dehydrated time of 5 min, and a formamide concentration of 55% in hybridized solution. The abundance of syntrophic acetogenic bacteria of different environmental samples were quantified by FISH and the results showed that Upflow Anaerobic Sludge Reactor (UASB) treating STHZ high-concentration organic wastewater and the digestive tract of some animals were the main habitats of syntrophic acetogenic bacteria. The numbers of syntrophic acetogenic bacteria in UASB and cattle manure were 1.70 x 10(9) cells/mL sample and 6.50 x 10(8) cells/mL sample, respectively. Meanwhile, the sediments of rivers and lakes existed less of the bacteria and the contents of them were just about 1.20 x 10(8) cells/mL sample in Taihu lake.

[The effect of preventing anterior segment ischemia by preservation of anterior ciliary vessels in rabbit].

OBJECTIVE: To investigate the effect of preserving anterior ciliary vessels (ACVs) on the prevention of anterior segment ischemia syndrome (ASI) during the surgery of extraocular muscles. METHODS: Thirty-two adult New Zealand white rabbits were randomly divided into four groups. ACVs of the right eyes were preserved among all of the rabbits, and were cut off in all of the left eyes. Group A: internal and external recti were cut off in two eyes; Group B: superior and inferior recti were cut off in two eyes; Group C: internal, external and superior or inferior recti were cut off in two eyes; Group D: all of the recti were cut off in two eyes. All rabbits were observed under slit microscope. The intraocular pressure (IOP), the total protein and lactic acid in the aqueous humor were recorded preoperatively and postoperatively. Eyes were enucleated at the forth week postoperatively to obtain the iris and the ciliary body for histopathologic study and electron microscopy. RESULTS: No signs of ASI were observed in the right eyes of all four groups under the slit lamp and under the light and election microscopes. The IOP and levels of ingredients of aqueous humor (total protein and lactic acid) showed no difference between preoperative and postoperative interval. No obvious ASI was observed in the left eyes of group A. Mild reactions of ASI were observed in the left eyes of group B. Moderate to severe reactions of ASI were observed in the left eyes in group C and group D. The IOP reduced from (17.21 +/- 3.76) mm Hg (1 mm Hg = 0.133 kPa) preoperatively to (14.48 +/- 3.36) mm Hg postoperatively in group C (P < 0.05); and from (16.68 +/- 2.33) mm Hg reduced to(3.17 +/- 0.92) mm Hg in group D. (P < 0.05). The level of total protein and lactic acid in the aqueous humor increased from (505.3 +/- 5.0) mg/L and (7.54 +/- 0.47) g/L preoperatively to (811.9 +/- 44.4) mg/L and (11.00 +/- 3.59) g/L postoperatively in group C, respectively (P < 0.05). In group D, the level of total protein and lactic acid in the aqueous humor increased from (504.6 +/- 4.1) mg/L and (7.17 +/- 1.44) g/L preoperatively to (1025. 8 +/- 78.3) mg/L, (8.23 +/- 1.68) g/L postoperatively, respectively (P < 0.05). There were various histopathological changes under the light and electron microscope in groups C and D. While no obvious ischemic changes were observed in group A. CONCLUSION: Two vertical muscles cut off at one eye simultaneously would produce mild reactions of ischemia, while three or more muscles cut off simultaneously could obstruct blood flow in eyes and induce ASI. Preservation of the ACVs could avoid the occurrence of ASI.