Oxidative Stress and Apoptosis of Human Brain Microvascular Endothelial Cells Induced by Free Fatty Acids

Damage to endothelial cells is a key event in the pathogenesis of atherosclerosis and vascular disease. This study aimed to determine whether free fatty acids (FFAs) induced oxidative stress and apoptosis in human brain microvascular endothelial cells (HBMVECs) in vitro and, if so, which signalling pathway mediated these effects. After culture in different concentrations of FFAs for 24-72 h, cell viability/proliferation was determined using a cell counting kit, apoptosis was detected by measuring caspase-3 activity and by using annexin V-conjugated fluorescein isothiocyanate/propidium iodide staining, and oxidative stress was evaluated by measuring the levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP). The HBMVECs exposed to FFAs showed significantly decreased cell proliferation, increased apoptosis and ROS levels, and decreased MMP. In conclusion, the results showed that high levels of FFAs induced oxidative stress, which damaged HBMVECs and resulted in apoptosis.

[Treatment of intra-articular fracture of distal radius with T-shaped plate internal fixation]

OBJECTIVE

To evaluate the effects of T-shaped plate internal fixation in treatment of intra-articular fracture of distal radius.

METHODS

From January 2005 to March 2008, 52 cases of intra-articular fracture of distal radius were treated, including 32 males and 20 females and aging 21-60 years old (mean 47 years old). Fracture was caused by tumbling in 30 cases, by falling from height in 8 cases, by traffic accident in 11 cases, and by a crashing object in 3 cases. Of 52 cases, there were 50 cases of closed fracture and 2 cases of open fracture. According to AO standard of classification, there were 14 cases of B2 type, 16 cases of B3 type, 15 cases of C1 type, 6 cases of C2 type, and 1 case of C3 type. According to the Cooney's general standard of classification of unstable fracture, there were 5 cases of type II, 10 cases of type III, and 37 cases of type IV. The time from injury to operation was 3-14 days (mean 5 days). All patients received open reduction and T-shaped plate fixation. Seven patients having bone defect were given 6-15 g autologous ilium or 5 mL calcium sulphate artificial aggregate after reduction.

RESULTS

All incisions healed by first intention. All the patients were followed up for 15 to 30 months postoperatively (mean 24 months). The X-ray films showed good anatomical reduction, even articular surface and no loosening of internal fixation in all the cases. The fractures healed within 9-15 weeks after operation (mean 12 weeks). At last follow-up, the mean palmar tilt was 8 degrees and the mean ulnar variance was 21 degrees, showing statistically significant differences when compared preoperation (-5 degrees and 5 degrees, P < 0.05). The radial length were not abbreviated. According to Dienst assessment, the results were excellent in 42 cases, good in 3 cases, fair in 5 cases and poor in 2 cases 12 weeks after operation, and the excellent and good rate was 86.5%.

CONCLUSION

T-shaped plate fixation is reliable and effective in treatment of intra-articular fracture of distal radius because it has less complication of infection, loosening of internal fixation, reduction failure and tendon rupture.

Hepatocyte inflammation model for cytotoxicity research: fructose or glycolaldehyde as a source of endogenous toxins

Insulin resistance and hepatotoxicity induced in high fructose fed rats may involve fructose derived endogenous toxins formed by inflammation. Thus fructose was seventy-fold more toxic if hepatocytes were exposed to non-toxic levels of hydrogen peroxide (H(2)O(2)) released by inflammatory cells. This was prevented by iron (Fe) chelators, hydroxyl radical scavengers, and increased by Fe, copper (Cu) or catalase inhibition. Fructose or glyceraldehyde/dihydroxyacetone metabolites were oxidized by Fenton radicals to glyoxal. Glyoxal (15 microM) cytotoxicity was increased about 200-fold by H(2)O(2). Glycolaldehyde was enzymically formed from glyceraldehyde, the fructokinase/aldolase B product of fructose. Glycolaldehyde cytotoxicity was increased 20-fold by H(2)O(2). The oxidative stress cytotoxicity induced was attributed to the Fenton oxidation of glycolaldehyde forming glycolaldehyde radicals and glyoxal, since cytotoxicity was prevented by aminoguanidine (glyoxal trap) or Fenton inhibitors. Glyoxal was also the Fenton product responsible for glycolaldehyde protein carbonylation as carbonylation was prevented by aminoguanidine or Fenton inhibitors.

Over-expression of SOCS-3 gene promotes IL-10 production by JEG-3 trophoblast cells

Suppressor of cytokine signaling-3 (SOCS-3) plays an important role in negative regulation of inflammatory response. Evidence has shown that SOCS-3 and IL-10 expressions were significantly reduced in placental trophoblasts from preeclampsia. IL-10 is an anti-inflammatory cytokine. In this study, we sought to determine if enhance SOCS-3 expression could affect IL-10 production in placental trophoblasts. Placental JEG-3 cells were used. Over-expression of SOCS-3 was generated by transfection of JEG-3 cells with a green fluorescent protein (GFP) tagged SOCS-3 gene, SOCS-3/ZsGreen1, by siPORT lipid transfection. Cells transfected with ZsGreen1 vector only was used as control. Our results showed that IL-6 production was reduced in cells over-expressed with SOCS-3. Moreover, SOCS-3 transfected cells produced more IL-10 when stimulated with IL-6. The increased IL-10 production by JEG-3 cells was in a dose-dependent manner, p<0.05. Our data suggested that enhanced SOCS-3 gene expression could promote IL-10 production by placental trophoblast cells, suggesting that SOCS-3 may play an important role in regulation of cytokine induced anti-inflammatory response in placental trophoblasts.

Altered interleukin-6 receptor, IL-6R and gp130, production and expression and decreased SOCS-3 expression in placentas from women with pre-eclampsia

Interleukin-6 (IL-6) and its receptor complex, IL-6 receptor (IL-6R) and gp130, are critical in induction of suppressor of cytokine signalling-3 (SOCS-3) protein, a negative cytokine regulator and anti-inflammatory mediator, in a biological system. Increased inflammatory response is believed to contribute to the placental dysfunction in pre-eclampsia (PE). However, it is not known if altered IL-6 receptor signalling and decreased SOCS-3 expression occur in placentas from PE. To study this, we examined IL-6, soluble IL-6R (sIL-6R) and soluble gp130 (sgp130) production by villous tissue from normal and PE placentas. Hypoxia effects on IL-6, sIL-6R and sgp130 production was determined. IL-6R, gp130 and SOCS-3 expression were determined by immunohistochemical staining and by Western blot. Our results showed that under normoxic conditions (21% O(2)), villous tissue from PE placentas produced relative more sgp130, but significantly less IL-6 and sIL-6R (p<0.01) than normal placental tissue. The ratio of sgp130/sIL-6R release was significantly higher by PE placentas than normal placentas, p<0.01. Under hypoxic conditions (2% O(2)), IL-6 production was significantly reduced by both normal (p<0.01) and PE (p<0.05) placental tissue. Hypoxia promoted sgp130 release by normal, but not by PE, placental tissue. Reduced IL-6R and SOCS-3 immunostaining and expression were found in PE placentas. We concluded that increased ratio of sgp130/sIL-6R production and/or reduced sIL-6R production combined with down-regulation of IL-6R and SOCS-3 expression in trophoblasts may lead to less cytokine inhibitory activity in PE placentas, which may account for the increased placental inflammatory response in PE.

Fructose and carbonyl metabolites as endogenous toxins

Dietary fructose consumption is one of the environmental factors contributing to the development of obesity and a fatty liver (hepatic steatosis). A two-hit hypothesis has been proposed for progression of hepatic steatosis to the more serious non-alcoholic steatosis (NASH), with the first hit being hepatic steatosis, and the second hit being inflammation and associated oxidative stress caused by reactive oxygen species (ROS) formation. As well, fructose-fed rats develop insulin resistance and serum levels of methylglyoxal, a glycolytic metabolite, are increased. Previously we reported that glyoxal-induced hepatocyte cytotoxicity could be attributed to mitochondrial toxicity as mitochondrial membrane potential was decreased and cytotoxicity was increased several orders of magnitude by low non-cytotoxic doses of H(2)O(2) (hepatocyte inflammation model). In this study, we have assessed the toxicity of fructose towards hepatocytes and investigated the molecular cytotoxic mechanisms involved. Fructose itself was only toxic at 1.5M, whereas 12 mM caused 50% cell death in 2h if the hepatocytes were exposed to a non-cytotoxic dose of H(2)O(2) continuously generated by glucose and glucose oxidase. The cytotoxic mechanism involved oxidative stress as ROS and H(2)O(2) formation preceded cytotoxicity, and cytotoxicity was prevented by radical scavengers, lipid antioxidants and ROS scavengers. It is proposed that the highly potent Fenton derived ROS catalyse the oxidation of fructose and particularly its carbonyl metabolites glycolaldehyde, dihydroxyacetone, glyceraldehyde. The carbon radicals and glyoxal formed compromise the cell's resistance to H(2)O(2).

[A clinical report on arthroscopic reconstruction of posterior cruciate ligament using ligament advanced reinforcement system]

OBJECTIVE

To explore the operative techniques and preliminary clinical effect of arthroscopic reconstruction of posterior cruciate ligament (PCL) using ligament advanced reinforcement system (LARS).

METHODS

From June 2006 to July 2007, 9 patients with PCL rupture were treated with LARS under arthroscopic observation. There were 8 males and 1 female, aged 23-49 years old. The left knee was involved in 3 cases and the right knee in 6 cases. The main causes of injuries were sports in 5 cases, falling in 1 case and traffic accident in 3 cases. The time from injury to reconstruction was 6-20 days (13.6 days on average). There were 2 cases with associated medial meniscus injury and 1 with lateral meniscus injury. X-ray films showed no avulsion fracture of tibial plateau was found. The preoperative Lysholm score was 40-55 (50 on average). According to the preoperative international knee documentation committee (IKDC) grading, 1 case was graded as C and 8 as D. The Lachman test showed that there was 1 case (+), 6 cases (++) and 2 cases (+++). The operation was performed under arthroscopic observation. The tibial isometric point and tunnel were drilled with the help of a drill bit guide, while the femoral isometric point and tunnel were drilled under the C-arm X-ray machine. The diameter of the bone tunnels was 6 mm, while the diameters of LARS artificial ligaments and cannulated interference screws were 7 mm.

RESULTS

All the patients were regularly followed up for 8-16 months (10.5 months on average). The postoperative Lysholm score was 70-95 (85 on average). There were 5 cases of excellent, 3 of good and 1 of fair, with the choiceness rate of 88%. The postoperative IKDC grading showed that 7 cases were graded as A and 2 as B. The Lachman test showed that no case was positive. Complications such as infection, spontaneous rupture or laxity of graft were not observed.

CONCLUSION

PCL arthroscopic reconstruction with the use of LARS artificial ligaments leads to a good anatomic reconstruction and knee function with minor injury, rapid recovery and satisfactory clinical effect.

[Application of allograft bone transplantation in treatment of displaced intra-articular calcaneal fractures]

OBJECTIVE

To investigate the operative treatment of displaced intra-articular calcaneal fractures (DIACFs) using a combination of small lateral incision approach and internal fixation and allograft bone transplantation.

METHODS

From January 2005 to December 2007, 28 patients with 34 DIACFs were treated with open reduction, allograft bone transplantation and internal fixation through a small lateral incision approach. Of them, there were 18 males and 10 females, aged 16-65 years. The disease course was 2 hours to 18 days. According to Sanders classification, there were 18 cases of type II fractures, 10 cases of type III fractures and 6 cases of type IV fractures.

RESULTS

22 patients with 28 DIACFs were followed up 18.5 months (13-28 months). The wound of 26 feet achieved primary healing, the acute rejection was found in 2 patients and developed wound complications. Both patients underwent further surgery prior wound healing. After the internal fixation were removed, fractures was fixed with external fixator, closed continuous irrigation and drainage was employed. In the meantime, both patients received antibiotics and incisional dressing change. As a result, one achieved primary healing, the other developed delayed healing. The preoperative X-ray film showed that Böhler angle was (6.19 +/- 9.66) degrees and Gissane angle was (103.04 +/- 15.03) degrees; the postoperative X-ray film demonstrated that Böhler angle was (34.51 +/- 5.89) degrees and Gissane angle was (112.18 +/- 10.50) degrees; showing statistically significant differences (P < 0.05). The internal fixation of 12 patients (14 DIACFs) were removed at 6 -10 months after operation, Böhler angle was (32.81 +/- 5.10) degrees and Gissane angle was (110.81 +/- 9.98) degrees. When compared with preoperative X-ray film, statistically significant differences (P < 0.05) was found, but there was no statistically significant differences (P > 0.05) when compared with normal X-ray film. According to the American Orthopedic Foot and Ankle Society evaluation system for ankle-hind foot, 3 feet scored 60-70 points, 10 feet 70-80 points, 12 feet 80-90 points and 3 feet 90-100 points.

CONCLUSION

Allograft bone transplantation is an option for management of DIACFs, because it enables satisfactory reconstruction of bone defects, allows met anatomic reduction and functional recovery, maintaining restoration of calcaneal height and anatomic reduction of the posterior facet.

[Platelet-rich plasma and its applications in orthopedics field]

OBJECTIVE

To introduce the current situation of platelet-rich plasma (PRP) and its application in orthopedics field.

METHODS

The latest literature was reviewed, concerning the preparations of PRP, physiological mechanism and the latest applications in orthopedics field.

RESULTS

PRP represent a new biotechnology for the stimulation and acceleration of tissue healing and bone regeneration. To succeed, some of the challenges need to be addressed including standardization and definition of the different PRP preparations, the complete characterization of the platelet released factors and proteins. Furthermore, well-designed studies and clinical trials are needed to evaluate the potential therapeutic impact of PRP.

CONCLUSION

PRP provides a novel application for orthopedics field.

Effect of pre-freezing conditions on semen cryopreservation in rhesus monkeys

Although sperm cryopreservation has been studied in at least 17 non-human primate species, systematic factor optimization for any single species is lacking. Gene banking of non-human primate sperm is still in its infancy. The objective of the present study was to initiate a systematic approach to optimize the process of sperm cryopreservation for rhesus macaques, specifically, factors related to pre-freezing conditions (e.g., straw freezing position, sperm concentration, sperm washing, equilibration methods, and equilibration time periods). Straw position had no effect on post-thaw motility (P=0.193). Sperm concentration was tested in a range from 5 x 10(6)mL(-1) to 5 x 10(8)mL(-1); post-thaw motility of sperm samples frozen at 5 x 10(7)cell mL(-1) (51.0+/-10.6%; mean+/-S.D.) and 5 x 10(8)cell mL(-1) (48.1+/-7.3%) were higher than samples frozen at 5 x 10(6)cells mL(-1) (33.0+/-12.0%, P=0.003). Comparison of motility immediately after thawing between samples with (51.2+/-6.2%) and without washing (53.9+/-6.8%) revealed no differences (P>0.05). However, washing improved sperm forward progression within 1h after thawing, whereas unwashed sperm retained higher post-thaw motility and progression during extended incubation (4h) after thawing (P<0.05). Equilibration methods (with or without pre-cooling) made no difference on post-thaw motility (P>0.05), and the most effective equilibration time was the duration required for samples to acclimate to 4 degrees C prior to freezing. Evaluation and optimization of these pre-freezing conditions will help to minimize sources of injury, maximize survival, and contribute to the development of an optimized cryopreservation protocol for rhesus macaque sperm.

Effectiveness of postural and instrumental reduction in the treatment of thoracolumbar vertebra fracture

We compared the effectiveness of postural reduction and instrumental reduction in the treatment of thoracolumbar and lumbar vertebra fracture in 40 patients. Under general anaesthesia, postural reduction in a stretching prone position was first performed. Instrumental reduction and fixation were then conducted. Radiographs were made after each reduction. Comparisons between the two films and the fracture films were made based on the changes in prevertebral height of both the fractured vertebra and the adjacent superior and inferior intervertebral spaces. It was found that the recovery of the prevertebral height in postural and instrumental reductions was basically identical. The recovery of the prevertebral height in the intervertebral spaces was more significant in instrumental reduction. Both reductions were ineffective in patients whose compression of the diseased vertebra was more than two-thirds of the normal. In cases of lower lumbar vertebra fractures, the effect of both reductions was unsatisfactory. Our findings indicated that the effectiveness of the reduction of vertebra fracture depends on the quantitative change of the spongy bone of the injured vertebra. Instrumental reduction only exerts an indirect tension. Postural reduction is effective in reducing thoracolumbar vertebral fracture, while instrumental reduction exerts only a relatively weak effect but it is particularly useful to maintain the result of postural reduction.

New global communication process in thermodynamics: impact on quality of published experimental data

Thermodynamic data are a key resource in the search for new relationships between properties of chemical systems that constitutes the basis of the scientific discovery process. In addition, thermodynamic information is critical for development and improvement of all chemical process technologies. Historically, peer-reviewed journals are the major source of this information obtained by experimental measurement or prediction. Technological advances in measurement science have propelled enormous growth in the scale of published thermodynamic data (almost doubling every 10 years). This expansion has created new challenges in data validation at all stages of the data delivery process. Despite the peer-review process, problems in data validation have led, in many instances, to publication of data that are grossly erroneous and, at times, inconsistent with the fundamental laws of nature. This article describes a new global data communication process in thermodynamics and its impact in addressing these challenges as well as in streamlining the delivery of the thermodynamic data from "data producers" to "data users". We believe that the prolific growth of scientific data in numerous and diverse fields outside thermodynamics, together with the demonstrated effectiveness and versatility of the process described in this article, will foster development of such processes in other scientific fields.

Subzero water permeability parameters and optimal freezing rates for sperm cells of the southern platyfish, Xiphophorus maculatus

This study reports the subzero water transport characteristics (and empirically determined optimal rates for freezing) of sperm cells of live-bearing fishes of the genus Xiphophorus, specifically those of the southern platyfish Xiphophorus maculatus. These fishes are valuable models for biomedical research and are commercially raised as ornamental fish for use in aquariums. Water transport during freezing of X. maculatus sperm cell suspensions was obtained using a shape-independent differential scanning calorimeter technique in the presence of extracellular ice at a cooling rate of 20 degrees C/min in three different media: (1) Hanks' balanced salt solution (HBSS) without cryoprotective agents (CPAs); (2) HBSS with 14% (v/v) glycerol, and (3) HBSS with 10% (v/v) dimethyl sulfoxide (DMSO). The sperm cell was modeled as a cylinder with a length of 52.35 microm and a diameter of 0.66 microm with an osmotically inactive cell volume (Vb) of 0.6 V0, where V0 is the isotonic or initial cell volume. This translates to a surface area, SA to initial water volume, WV ratio of 15.15 microm(-1). By fitting a model of water transport to the experimentally determined volumetric shrinkage data, the best fit membrane permeability parameters (reference membrane permeability to water at 0 degrees C, Lpg or Lpg [cpa] and the activation energy, E(Lp) or E(Lp) [cpa]) were found to range from: Lpg or Lpg [cpa] = 0.0053-0.0093 microm/minatm; E(Lp) or E(Lp) [cpa] = 9.79-29.00 kcal/mol. By incorporating these membrane permeability parameters in a recently developed generic optimal cooling rate equation (optimal cooling rate, [Formula: see text] where the units of B(opt) are degrees C/min, E(Lp) or E(Lp) [cpa] are kcal/mol, L(pg) or L(pg) [cpa] are microm/minatm and SA/WV are microm(-1)), we determined the optimal rates of freezing X. maculatus sperm cells to be 28 degrees C/min (in HBSS), 47 degrees C/min (in HBSS+14% glycerol) and 36 degrees C/min (in HBSS+10% DMSO). Preliminary empirical experiments suggest that the optimal rate of freezing X. maculatus sperm in the presence of 14% glycerol to be approximately 25 degrees C/min. Possible reasons for the observed discrepancy between the theoretically predicted and experimentally determined optimal rates of freezing X. maculatus sperm cells are discussed.

Extent of white matter lesions is related to acute subcortical infarcts and predicts further stroke risk in patients with first ever ischaemic stroke

OBJECTIVE

To investigate whether the extent of white matter lesions (WML) on fluid attenuated inversion recovery (FLAIR) MRI sequences is an independent risk factor for recurrent stroke, and to document the pattern of acute cerebral infarcts using diffusion weighted imaging (DWI) in patients with different severities of WML.

METHODS

In a prospective cohort study, 228 consecutive stroke patients were studied between 1999 and 2001 in a community hospital. The severity of WML was graded as 0 (no WML), 1 (mild), 2 (moderate), or 3 (severe) according to the FLAIR appearances. DWI was used to document the location and size of the infarct.

RESULTS

31 patients had grade 0 WML, 69 had grade 1, 59 had grade 2, and 69 had grade 3. Age was independently associated with WML on logistic regression analysis (p = 0.0001). Acute cerebral infarcts in deep white matter were correlated with increasing severity of WML. On a median follow up of 23.0 months, life table analysis showed that recurrent stroke was related to the severity of WML (recurrence rate 7.8% in grade 0, 9.3% in grade 1, 17.7% in grade 2, 43.7% in grade 3; p = 0.0001). Survival was reduced in patients with severe WML (p = 0.0068). A Cox proportional hazards model showed WML to be predictive of recurrent stroke (p = 0.000, hazard ratio = 4.177 (95% confidence interval, 2.038 to 8.564)) and also for survival (p = 0.040, hazard ratio = 2.021 (1.032 to 3.960)).

CONCLUSIONS

Patients with severe leukoaraiosis have increased risk of deep subcortical stroke and a higher risk of recurrent stroke.

Diffusion tensor imaging of the brain: review of clinical applications

We review the theoretical background to diffusion tensor imaging (DTI) and some of its commoner clinical applications, such as cerebral ischemia, brain maturation and traumatic brain injury. We also review its potential use in diseases such as epilepsy, multiple sclerosis, and Alzheimer's disease. The value of DTI in the investigation of brain tumors and metabolic disorders is assessed.

Screw placement of pedicle of vertebral arch--pay great attention to segmental differences of the pedicle

OBJECTIVE

To investigate appropriate ways for screw placement of pedicle of vertebral arch in the horizontal plane.

METHODS

Fifteen preserved thoracolumbar spine specimens (T(11)-L(5)) were used and divided into three groups at random. Firstly four anatomic parameters indicating screw positions in the horizontal plane were measured. Secondly the methods of Roy-camille, Magerl, and authors' segmental differences were used to place successively the screws of the pedicles with 5 mm, 6 mm, and 7 mm in diameter. Coincidences between the drilling point, drilling direction and pedicle axis, and ruptures of the pedicle as well as the length of the screw in the vertebral body were observed.

RESULTS

Four anatomic parameters at various segments showed significant differences (P<0.05). The drilling point by the Roy-camille's method deviated medial to pedicle axis in most segments, and its drilling direction did not coincide well with most E-angles of the pedicles. The drilling point by Magerl's method coincided relatively well with pedicle axis in lumbar vertebrae, but there were still some differences between its drilling direction and E-angles of the pedicles. The method of segmental differences coincided the best with the pedicle axis. The lengths of screw in the vertebra were relatively long by both Magerl and segmental difference methods. When 5 mm diametral screw was used by the three methods, the rupture rate was very low. When 6 mm and 7 mm diametral screws were placed, the rupture rate was accordingly increased. Of the three methods, Roy-camille's method showed a relatively high rupture rate, while the method of segmental differences a comparatively low rupture rate. Various degrees of rupture of the pedicle of vertebral arch were found at the juncture of the thoracic and lumbar vertebrae when 6 mm or 7 mm diametral screws was used by any screw placement method. In contrast, the rupture was seldom seen at the lower lumbar vertebrae when 7 mm diametral screws were used.

CONCLUSIONS

The segmental difference method is proved to have the anatomic safety and screw biomechanical stability. It is appropriate to choose different diametral screws, different drilling points and directions according to different segments of the vertebra.

[Studies on liver cancer induced by non-necrotizing dose of diethylnitrosamine in rats]

OBJECTIVE

To provide an appropriate animal model of liver cancer and sensitive indicator for carcinogen risk assessment.

METHODS

The developmental processes of liver cancers in rats initiated by non-necrotizing dose of diethylnitrosamine and promoted by phenobarbital were studied.

RESULTS

Most of the preneoplastic lesions and liver cancers were made up of eosinophilic cells. The placental glutathione S-transferase (P-GST) staining could allow a lot of positive single cells, foci and nodules to be seen. But the lesions showed by HE staining expressed higher proliferating cell nuclear antigen (PCNA) than those showed by P-GST staining expressed, indicating a greater possibility for these lesions to persist and develop further. The cellular morphologic analysis demonstrated that the ratio of nuclear radii to cytoplasm radii decreased in the cell in PCNA positive expressing nodules. In addition, the nodules showed by P-GST expressed higher PCNA than those the foci expressed, indicating an increased possibility to develop further in the nodules.

CONCLUSION

PCNA expression may be used as a relatively ideal marker for predicting the potential development of precancerous lesions in the experimental model of rat liver cancer induction.

[Study on effect of qingkailing injection and its active principle in inducing cell apoptosis in human acute promyelocytic leukemia]

OBJECTIVE

To investigate the mechanism of Qingkailing (QKL) Injection in treating acute promyelocytic leukemia.

METHODS

Using MTT technique, cell morphologic method, DNA gel electrophoresis and flow-cytometry to study the human acute promyelocytic leukemia (HL-60) cell apoptosis induced by QKL and its active principle.

RESULTS

QKL and its active principle, Baicalin and hyodeoxycholic acid, showed strong cytotoxicity in inhibiting HL-60 cell, the Bezoar cholic acid showed a weaker effect. Apoptosis could be induced after being treated for 6 hrs by the former three principles, showing a typical apoptosis peak under flow-cytometry, but could not be induced by the latter one.

CONCLUSION

QKL could induce leukemia cell apoptosis in vitro, which may be one of the mechanisms of QKLI in curing acute promyelocytic leukemia.

Overexpression of the A1 adenosine receptor in adipose tissue protects mice from obesity-related insulin resistance

In-vitro studies have implicated the A(1) adenosine receptor (A(1)AR) of adipocytes in inhibition of lipolysis, stimulation of lipogenesis and enhancement of the action of insulin on glucose metabolism. To determine whether any of these activities were physiologically relevant in an intact animal, A(1)AR was overexpressed in adipose tissue of transgenic mice. Lower plasma free fatty acid (FFA) levels were observed in the transgenic mice relative to the litter-matched controls, supporting a significant physiological role for adipocyte A(1)AR in the control of lipolysis. However, no differences were observed in body weights or body composition. On a high fat diet, both the transgenic mice and the litter matched controls, male and female, became equally obese. Unlike the control mice, however, the transgenic mice did not develop insulin resistance, as demonstrated by serum glucose and insulin levels and glucose and insulin tolerance tests. These findings demonstrate that adipocyte A(1)AR plays an important physiological role in the control of insulin sensitivity in an intact animal and therefore should be considered to be a potential therapeutic target for the treatment of obesity-related insulin resistance and type 2 diabetes.

Characterization of a calcium-activated chloride channel as a shared target of Th2 cytokine pathways and its potential involvement in asthma

Interleukin (IL)-9 is a T helper (Th) 2 cytokine recently implicated as an essential factor in determining susceptibility to asthma. Transgenic mice overexpressing IL-9 exhibit many features that are characteristic of human asthma. To better understand the mechanism by which IL-9 mediates the various biologic activities in asthma, we performed suppressive subtraction hybridization with whole lung from IL-9 transgenic and control mice. Here we report the identification of mCLCA3, a calcium-activated chloride channel that was specifically induced in the lung epithelium of IL-9 transgenic mice. Expression of mCLCA3 could also be induced by intratracheal administration of IL-9 or other Th2 cytokines (IL-4, IL-13), but not by interferon-gamma. Moreover, expression of mCLCA3 was induced in the lung of antigen-exposed mice, and this induction could be suppressed by neutralizing IL-9 antibody treatment, indicating IL-9 is both necessary and sufficient to induce mCLCA3 in this experimental model of asthma. Finally, we demonstrate that hCLCA1 is the human counterpart to mCLCA3 and is also induced in vitro in human primary lung cells by Th2 cytokine treatment. Together, these data strongly implicate the involvement of mCLCA3 (in mice) and hCLCA1 (in humans) in the pathogenesis of Th2 cytokine-mediated asthmatic disorders.

Neutrophil-mediated epithelial injury during transmigration: role of elastase

Neutrophil-mediated injury to gut epithelium may lead to disruption of the epithelial barrier function with consequent organ dysfunction, but the mechanisms of this are incompletely characterized. Because the epithelial apical junctional complex, comprised of tight and adherens junctions, is responsible in part for this barrier function, we investigated the effects of neutrophil transmigration on these structures. Using a colonic epithelial cell line, we observed that neutrophils migrating across cell monolayers formed clusters that were associated with focal epithelial cell loss and the creation of circular defects within the monolayer. The loss of epithelial cells was partly attributable to neutrophil-derived proteases, likely elastase, because it was prevented by elastase inhibitors. Spatially delimited disruption of epithelial junctional complexes with focal loss of E-cadherin, beta-catenin, and zonula occludens 1 was observed adjacent to clusters of transmigrating neutrophils. During neutrophil transmigration, fragments of E-cadherin were released into the apical supernatant, and inhibitors of neutrophil elastase prevented this proteolytic degradation. Addition of purified leukocyte elastase also resulted in release of E-cadherin fragments, but only after opening of tight junctions. Taken together, these data demonstrate that neutrophil-derived proteases can mediate spatially delimited disruption of epithelial apical junctions during transmigration. These processes may contribute to epithelial loss and disruption of epithelial barrier function in inflammatory diseases.

Loss of annexin II heavy and light chains in prostate cancer and its precursors

Annexin II mRNA coding for a calcium binding protein was found to be absent in prostate cancer by subtractive hybridization and Northern analysis. In contrast to high expression in normal and benign hyperplastic glandular and basal epithelium, Annexin II heavy (p36) and light (p11) chains in 31/31 prostate cancer specimens were lost immunohistochemically. In glands involved by prostate intraepithelial neoplasia, 65% lost both chains in glandular epithelial cells, whereas basal cells were all positively stained. Southern analysis of cancer DNA showed no noticeable deletion in p36 gene. LNCaP cells treated with 5-azacytidine re-expressed p36, suggesting methylation could be responsible for the silencing.

The involvement of a stress-activated pathway in equine influenza virus-mediated apoptosis

We have shown elsewhere that equine-2 influenza virus (EIV; subtype H3N8) induced pronounced cell death in infected cells through apoptosis as demonstrated by DNA fragmentation assay and a combined TUNEL and immunostaining scheme. In this study, we investigated the mechanism of EIV-mediated cytotoxicity on a permissive mammalian epithelial cell line, Madin-Darby canine kidney (MDCK) cells. EIV infection increased the cellular levels of oxidative stress and c-Jun/AP-1 protein (which is known to be affected by oxidative stress), as well as its DNA binding activity. Increased production of TGF-beta1, an inducer of c-Jun N-terminal kinase or stress-activated protein kinase (JNK/SAPK) activation, was also detected in EIV-infected MDCK cells. It has been reported that TGF-beta may initiate a signaling cascade leading to JNK/SAPK activation. Addition of c-Jun antisense oligodeoxynucleotide, antioxidant N-acetyl-cysteine (NAC), JNK/SAPK inhibitor carvedilol, or TGF-beta-neutralizing antibody effectively blocked c-Jun/AP-1 upregulation and TGF-beta1 production mediated by EIV infection. These treatments also attenuated EIV-induced cytopathogenic effects (CPE) and apoptosis. Our results suggest that a stress-activated pathway is involved in apoptosis mediated by EIV infection. It is likely that EIV infection turns on the JNK/SAPK cascade, which modulates the activity of apoptosis-promoting regulatory factor c-Jun/AP-1 and epithelial growth inhibitory cytokine TGF-beta.

Monitoring diclofenac sodium in single human erythrocytes introduced by electroporation using capillary zone electrophoresis with electrochemical detection

A method for determination of the drug diclofenac sodium introduced into individual human erythrocytes by electroporation using capillary zone electrophoresis with electrochemical detection at a carbon fiber array microelectrode was developed. In this method, the whole cell was injected into the separation capillary by electromigration. Cell lysis was accomplished by injecting a plug of the separation buffer (1.25 x 10(-2) mol/L Na2B4O7-3.13 x 10(-3) mol/L NaOH). The optimum conditions of separation and detection were 20 kV for the separation voltage and 1.0 V for the detection potential. The concentration of diclofenac sodium in the single cells was quantified by a calibration curve. The mean concentration of diclofenac sodium introduced into the cell was 4.21 micromol/L. The relative standard deviation of the concentration of diclofenac sodium introduced into ten cells is 10%.

[Research proceeding on the effect of microgravity on erythropoiesis]

The reduction of red blood cell mass is a main change of hematology under microgravity. It is considered that the decrease of erythroid cell production is the key cause. The studies on reticulocytes, Price-Jones curve, ferrum turn over, cytology of bone marrow and Erythropoietin (Epo) level suggested the suppression of erythropoiesis was due to microgravity. The mechanisms about it and the aspects of research in the future were discussed briefly.

Direct electrochemical determination of pyruvate in human sweat by capillary zone electrophoresis

Capillary zone electrophoresis was employed for the determination of pyruvate in human sweat using electrochemical detection with a carbon fiber microdisk bundle electrode at a constant potential of 1.60 V vs. saturated calomel electrode. The optimum separation conditions are 3.6 x 10(-3) mol/L Na2HPO4-1.4 x 10(-3) mol/L NaH2PO4 (pH 7.2) for the buffer solution, and 18 kV for the separation voltage. The limits of detection of pyruvate are 8.0 x 10(-6) mol/L or 24 fmol (S/N = 3) for the injection voltage of 6 kV and the injection time of 10 s. The relative standard deviation is 2.0% for the migration time and 5.7% for the electrophoretic peak current. The method was applied to determining pyruvate in human sweat.

Quantitative reverse transcriptase polymerase chain reaction assay for mouse androgen receptor mRNA

A quantitative reverse transcriptase polymerase chain reaction (RT-PCR) assay for mouse androgen receptor (AR) mRNA was developed to study relative changes in AR gene expression. Serial dilutions of a standard comprising a fragment of the ampicillin resistance gene flanked by the primer sequences of the AR mRNA were added to a constant amount of total RNA for RT-PCR. Primers were designed to generate a 541-bp fragment of mouse AR mRNA (target [T]) and a 460-bp fragment of the standard (S). PCR products were resolved by gel electrophoresis and quantitated by densitometry. A standard curve was generated for each sample by plotting the logarithm of T/S products vs the logarithm of the amount of S added. The amount of T was determined from the standard curve where intensities of PCR products of T and S were equal. The assay was validated by measuring the relative abundance of AR mRNA in 10 mouse tissues, and results were consistent with studies of AR expression in rat tissues. Assay reproducibility, tested by repeating assays on four different tissues on different days from the RT step, had a coefficient of variation of 6-16%. The current assay is thus both reproducible and valid in quantitation of mouse AR mRNA.

Structural elucidation of a new arabinogalactan from the leaves of Nerium indicum

A polysaccharide fraction, NIB-2, was obtained from the 3% aqueous sodium carbonate extract of Nerium indicum leaves using anion-exchange chromatography and gel-permeation chromatography. It was found to be composed of rhamnose, arabinose, galactose, in the ratios of 1.0:10.4:4.4, along with 4% of galacturonic acid. The results of methylation analysis, periodate oxidation, partial acid hydrolysis, pectinase treatment, and 13C and 1H NMR spectroscopy indicate that it is mainly an arabinogalactan having a backbone of 1,6-linked beta-Galp, with branches at O-3, consisting of terminal, 1,5-, and 1,3,5-linked arabinofuranosyl residues, and a small proportion of galactosyl residues at the termini. Rhamnose and galacturonic acid arose from a contaminating rhamnogalacturonan.

Identification of differentially expressed genes in organ-confined prostate cancer by gene expression array

BACKGROUND

To understand the molecular mechanisms underlying prostate cancer, we have utilized the gene expression array to search for genes whose expression is altered in this disease.

METHODS

RNA quality from manual microdissected tissue was compared with that from microselected tissue by electrophoresis. For array analysis, malignant and normal prostate epithelium was enriched using microselection technique from prostate cancer and the peripheral zone of a normal prostate. Identical array membrane was hybridized to labeled cancer and normal cDNA, respectively. The differentially expressed gene was further evaluated by RT-PCR.

RESULTS

Microdissection, but not microselection, causes visible degradation to RNA. Of the 588 genes on the membrane, 87 genes yielded significant signals. Based on a three fold difference relative to normal prostate tissue, 1 gene was overexpressed and 12 genes underexpressed in prostate cancer. Of them, five showed statistically significant reduction in mRNA levels in six prostate cancer specimens compared with seven normal prostate specimens. These five genes are glutathione S-transferase M1 (GSTM1), monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha receptor-1 (TNFR-1), transforming growth factor beta3 (TGF-beta3), and inhibitor of DNA binding-1 (ID-1).

CONCLUSIONS

GST-based metabolism, cytokine MCP-1 and TNFR-1, and TGF-beta3 signaling pathways, and some helix-loop-helix nuclear proteins could be potentially important in organ-confined prostate cancer and deserve further investigation.

Identification of genes regulated by prolonged acid exposure in Helicobacter pylori

To investigate the influence of prolonged acid exposure on the gene expression, transcripts of Helicobacter pylori, grown under pH 5.5 and pH 7.4 for five successive passages, were analysed by differential display PCR. Eight genes were regulated by prolonged acid exposure. These genes included topA, tufB, ureB, flaA, atoE in the H. pylori genome and a cDNA fragment with 54% identity of the predicted amino acid sequence to a Bacillus cereus YkoW protein. The remaining two cDNA fragments had no significant homology to known sequences. Our data suggest that most of these genes might be required for the resistance of H. pylori to prolonged acid exposure.

[The relationship between smoking and p53 and Ki-ras gene mutations in sputum cells of patients with lung cancer]

BACKGROUND

To study the relationship between gene's mutation in sputum cells and smoking consumption of patients with lung cancer.

METHODS

Sputum dispose liquid was added into 0.5ml sputum, DNA was extracted twicely with saturated phenol-chloroform and ethanol precipitate; p53 and K-ras gene mutations were detected by using SSCP-PCR and RFLP-PCR methods.

RESULTS

Seventy-one of 110 patients with lung cancer were heavy smokers (index of smoking≥400), 55 of 71(77.5%) patients with heavy smoking were detected with gene alterations of p53 or K-ras (P<0.05). Average indexes of smoking in the patients with p53 or K-ras were 861 and 630 respectively, whereas those in non-smokers were 284 and 554 (Chi-square=36.56,P=0.002).

CONCLUSIONS

Detection of oncogene alterations in sputum is a simple method to practice. Oncogene alteration in smoking patients with lung cancer is higher, especially in heavy smokers, than those with no smoking. The results show that heavy smoking is one of the causes in oncogene mutations of bronchus and further investigation is necessary.

[Detection of telomerase activity in the blood of patients with lung cancer]

BACKGROUND

To study the telomerase activity in blood cancer cells by TRAP for monitoring tumor metastasis in blood.

METHODS

Twenty-five patients with lung cancer surgically treated and 35 patients before chemotherapy were determined for telomerase activity of cancer cells in the blood by TRAP, and 30 patients with non-tumor diseases as control.

RESULTS

In the operative group,13 patients(52%) showed telomerase activity in pulmonary artery blood during operation, which was much higher than that of peripheral blood before operation (24%,P<0.05). Telomerase positive rate was significantly higher in stage III to IV (64%) than that in stage I to II (30%,P<0.05).In the peripheral blood of patients with non-tumor diseases, telomerase was negative.

CONCLUSIONS

Telomerase activity may be an indicator for detecting lung cancer cells in peripheral blood as well as tumor metastasis and relapse.

[Changes of cardiovascular indices during head up tilt plus lower body negative pressure]

OBJECTIVE

To understand the change of the cardiovascular function and to evaluate the usefulness of sphygmography and heart rate variability (HRV) spectrum techniques on estimating cardiovascular function during HUP + LBNP.

METHOD

Blood pressure, ECG, cerebral oxygen saturation and sphygmogram of 16 subjects were studied during 75 degrees head up tilt plus lower body negative pressure (HUP + LBNP).

RESULT

(1) During HUP + LBNP, heart rate, blood pressure, normalized low frequency component (LFn), LFn/HFn increased significantly, the cerebral blood oxygen saturation, T wave (ECG), HFn decreased significantly; (2) Blood pressure, heart rate and cerebral blood oxygen saturation decreased significantly in presyncopal state; (3) The heart rate in low tolerance group was higher than that in high tolerance group during the initial stage of HUT + LBNP; (4) The shape of pulse wave changed enormously during HUP + LBNP, so that no analysis could be made.

CONCLUSION

HUP + LBNP was an effective approach to examine the regulatory function of cardiovascular system, and the sphygmogram could not be used in studying the regulatory function of cardiovascular system during HUP + LBNP.

Monitoring human serum transferrin by capillary zone electrophoresis with end-column amperometric detection

Capillary zone electrophoresis was employed for the determination of human serum transferrin using end-column amperometric detection with a carbon fiber microelectrode at a constant potential of 1.9 V vs. saturated calomel electrode (SCE). The optimum conditions of separation and detection are 7.5 x 10(-4) mol/L Tris-3.44 x 10(-4) mol/L HCl for the buffer solution, 20 kV for the separation voltage, 5 kV and 10 s for the injection voltage and the injection time, respectively. The limit of detection is 6.7 x 10(-8) mol/L or 440 amol (S/N = 2). The relative standard deviations are 0.67% for the migration time and 1.5% for the electrophoretic peak current. The method was applied to the determination of transferrin in human serum. The recovery is between 93-104%.

Deficiency of Src homology 2-containing phosphatase 1 results in abnormalities in murine neutrophil function: studies in motheaten mice

Neutrophils, an essential component of the innate immune system, are regulated in part by signaling pathways involving protein tyrosine phosphorylation. While protein tyrosine kinase functions in regulating neutrophil behavior have been extensively investigated, little is known about the role for specific protein tyrosine phosphatases (PTP) in modulating neutrophil signaling cascades. A key role for Src homology 2 domain-containing phosphatase 1 (SHP-1), a PTP, in neutrophil physiology is, however, implied by the overexpansion and inappropriate activation of granulocyte populations in SHP-1-deficient motheaten (me/me) and motheaten viable (me(v)/me(v)) mice. To directly investigate the importance of SHP-1 to phagocytic cell function, bone marrow neutrophils were isolated from both me/me and me(v)/me(v) mice and examined with respect to their responses to various stimuli. The results of these studies revealed that both quiescent and activated neutrophils from motheaten mice manifested enhanced tyrosine phosphorylation of cellular proteins in the 60- to 80-kDa range relative to that detected in wild-type congenic control neutrophils. MOTHEATEN: neutrophils also demonstrated increased oxidant production, surface expression of CD18, and adhesion to protein-coated plastic. Chemotaxis, however, was severely diminished in the SHP-deficient neutrophils relative to control neutrophils, which was possibly attributable to a combination of defective deadhesion and altered actin assembly. Taken together, these results indicate a significant role for SHP-1 in modulating the tyrosine phosphorylation-dependent signaling pathways that regulate neutrophil microbicidal functions.

Subclavian MR arteriography: reduction of susceptibility artifact with short echo time and dilute gadopentetate dimeglumine

At arterial phase gadolinium-enhanced magnetic resonance (MR) angiography, artifactual stenosis of the subclavian artery is sometimes seen adjacent to the subclavian vein on the side of the contrast material injection. Experiments in phantoms and in 19 patients showed increased artifact with longer echo time and higher concentration of injected contrast material. An effective method to substantially decrease this susceptibility artifact was threefold dilution of gadopentetate dimeglumine and use of a short echo time (1 msec).

Cloning of TC-1 (C8orf4), a novel gene found to be overexpressed in thyroid cancer

A novel gene highly expressed in thyroid cancer, designated TC-1 (thyroid cancer-1), was cloned from suppression subtractive hybridization between papillary thyroid carcinoma and its surrounding normal thyroid tissue. Overexpression of TC-1 in thyroid cancer was confirmed in 15/16 paired samples by RT-PCR and Northern analysis. Ubiquitously expressed in human tissues, the TC-1 sequence showed no homology to any known gene, but matched a cluster of ESTs. After alignment of our sequence with the ESTs, the missing transcription start site was obtained by 5'-RACE and verified by primer extension analysis. The full-length mRNA sequence of 1327 bp has an open reading frame of 321 bp, which encodes a highly conserved protein. Three regulatory motifs were identified at the expected positions within 1 kb of the 5' flanking sequence obtained by genome walking. Using fluorescence in situ hybridization, TC-1 was localized to chromosome 8p11.2. The overexpression of TC-1 in papillary carcinoma suggests that it may have an important role in thyroid carcinogenesis.