Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing

INTRODUCTION

Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis.

MATERIALS AND METHODS

We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP.

RESULTS

Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble/serum CD14, a highly specific bacterial wall product receptor, in mediating these effects. The decreased VEGF receptor density on ECs accruing from the presence of bacterial wall products resulted in EC hyporesponsiveness to rhVEGF and significant abolition of VEGF-directed EC proliferation.

CONCLUSION

These findings suggest that the well-recognized relationship between bacterial sepsis and attenuated wound healing may be due, in part, to the directly suppressive effects of bacterial wall components on EC VEGF receptor expression and, consequently, EC proliferation.

A novel phosphorylcholine-coated contact lens for extended wear use

The preparation and characterisation of a new phosphorylcholine (PC)-coated silicone hydrogel contact lens for use in extended wear is described. The Michael-type addition of amines to acrylates forms the basis of the synthesis of a novel silicone-based macromer with hydrophilic functionality. It is demonstrated that this macromer can be combined with other silicone-based monomers, hydrophilic monomers and crosslinker to produce a contact lenses formulation. Examples of lenses with water contents of 33% and 46% are illustrated and their properties compared to other commercially available lenses. Materials with comparatively low modulus (<0.3 MPa) and adequate tear strength (>2-4MPa) with excellent elongation to break (>200%) can be obtained using this technology. In addition to the mechanical aspects. both the oxygen and solute permeabilities of the material can be controlled by the hydrophilic: hydrophobic monomer balance in the formulation. to obtain materials with attributes suitable for extended wear use. The PC coating is achieved by means of an in-mould coating (IMC) technique that produces a uniform and stable surface as determined by staining and XPS. The coating imparts both improved lens wettability (advancing contact angle of approximately 50 with virtually no hysteresis) and lower protein adsorption relative to the uncoated lens.

[Two kaempferol triglycosides from pericarps of Sophora japonica L]

OBJECTIVE

To study the flavonol triglycosides in the pericarps of Sophora japonica.

METHOD

Various chromatographic techniques were used to isolate and purify the constituents. The structures were elucidated by chemical evidence and spectral analysis, especially by 2D NMR experiments.

RESULTS

Two kaempferol triglycosides were isolated and identified as kaempferol 3-O-beta-D-sophoroside-7-O-alpha-L-rhamnoside and kaempferol 3-O-(2"-O-beta-D-glucosyl)-beta-D-rutinoside.

CONCLUSION

Both of them were reported in S. japonica for the first time.

Tamoxifen inhibits endothelial cell proliferation and attenuates VEGF-mediated angiogenesis and migration in vivo

INTRODUCTION

Angiogenesis is fundamental to tumour growth and vascular endothelial growth factor (VEGF) is one of the most potent proangiogenic cytokines known. We have previously demonstrated that tamoxifen reduces serum VEGF in certain cancer patients. We hypothesized that tamoxifen may attenuate the angiogenetic response to VEGF.

METHODS

Human dermal microvessel endothelial primary cell cultures (HMEC) were incubated with tamoxifen (1.25-5.0 microg) or vehicle. Cell proliferation was quantified using 5-bromo-2'-deoxyuridine (BrdU) labelling endothelial cell proliferation assay. The effect of oral tamoxifen (20 mg/day) on VEGF-mediated angiogenesis in vivo was assessed using a Matrigel angiogenesis assay in the Sprague-Dawley rat.

RESULTS

Tamoxifen (5.0 microg/ml) significantly reduced HMEC proliferation over 24 h when compared with cells treated with vehicle alone. Oral administration of tamoxifen in the rat (20 mg/day) significantly reduced endothelial cell proliferation and migration in response to VEGF.

CONCLUSION

Tamoxifen (5.0 microg/ml) reduces proliferation of a VEGF-dependent endothelial cell line in vitro. In vivo, orally administered tamoxifen reduces VEGF-mediated angiogenesis in the rat. These findings indicate that tamoxifen may directly inhibit the effect of VEGF on the endothelial cell, in addition to its previously described effect of reducing serum VEGF levels. This data supports a role for tamoxifen in modulation of the VEGF-dependent angiogenic response to surgical trauma, particularly as an adjuvant therapy for VEGF-dependent tumours.

Specificity of endothelial cell reorientation in response to cyclic mechanical stretching

Evidence suggests that cellular responses to mechanical stimuli depend specifically on the type of stimuli imposed. For example, when subjected to fluid shear stress, endothelial cells align along the flow direction. In contrast, in response to cyclic stretching, cells align away from the stretching direction. However, a few aspects of this cell alignment response remain to be clarified: (1) Is the cell alignment due to actual cell reorientation or selective cell detachment? (2) Does the resulting cell alignment represent a response of the cells to elongation or shortening, or both? (3) Does the cell alignment depend on the stretching magnitude or rate, or both? Finally, the role of the actin cytoskeleton and microtubules in the cell alignment response remains unclear. To address these questions, we grew human aortic endothelial cells on deformable silicone membranes and subjected them to three types of cyclic stretching: simple elongation, pure uniaxial stretching and equi-biaxial stretching. Examination of the same cells before and after stretching revealed that they reoriented. Cells subjected to either simple elongation or pure uniaxial stretching reoriented specifically toward the direction of minimal substrate deformation, even though the directions for the two types of stretching differed by only about 20 degrees. At comparable stretching durations, the extent of cell reorientation was more closely related to the stretching magnitude than the stretching rate. The actin cytoskeleton of the endothelial cell subjected to either type of stretching was reorganized into parallel arrays of actin filaments (i.e., stress fibers) aligned in the direction of the minimal substrate deformation. Furthermore, in response to equi-biaxial stretching, the actin cytoskeleton was remodeled into a "tent-like" structure oriented out of the membrane plane-again towards the direction of the minimal substrate deformation. Finally, abolishing microtubules prevented neither the formation of stress fibers nor cell reorientation. Thus, endothelial cells respond very specifically to the type of deformation imposed upon them.

Tourniquet-induced systemic inflammatory response in extremity surgery

BACKGROUND

Tourniquet-induced reperfusion injury in animals produces significant systemic inflammatory effects. This study investigated whether a biologic response occurs in a clinically relevant model of tourniquet-induced reperfusion injury.

METHODS

Patients undergoing elective knee arthroscopy were prospectively randomized into controls (no tourniquet) and subjects (tourniquet-controlled). The effects of tourniquet-induced reperfusion on monocyte activation state, neutrophil activation state, and transendothelial migration (TEM) were studied. Changes in the cytokines implicated in reperfusion injury, tumor necrosis factor-alpha, interleukin (IL)-1beta, and IL-10 were also determined.

RESULTS

After 15 minutes of reperfusion, neutrophil and monocyte activation were significantly increased. Pretreatment of neutrophils with pooled subject (ischemia-primed) plasma significantly increased TEM. In contrast, TEM was not significantly altered by ischemia-primed plasma pretreatment of the endothelial monolayer. Significant elevation of tumor necrosis factor-alpha and IL-1beta were observed in subjects compared with controls after 15 minutes of reperfusion. There was no significant difference in serum IL-10 levels between the groups at all the time points studied.

CONCLUSION

These results indicate a transient neutrophil and monocyte activation after tourniquet-ischemia that translates into enhanced neutrophil transendothelial migration with potential for tissue injury.

The angiogenic response to skeletal injury is preserved in the elderly

Angiogenesis is essential for normal bone formation and repair. Avascularity characterizes aberrant fracture union in the elderly, while angiogenic mechanisms during cutaneous wound repair are attenuated in aged humans. We hypothesized that skeletal injury results in local (circulating) and systemic (fracture site) 'angiogenic' responses and that these reparative mechanisms are attenuated with advanced patient age. This prospective study examined peripheral blood and fracture hematoma from 32 patients, 16 under 40 years and 16 over the age of 75, undergoing emergent surgery for isolated fracture. The angiogenic cytokines vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) were assayed. Endothelial cell cultures were supplemented with patient plasma and fracture hematoma and angiogenesis determined in vitro by measuring cell proliferation and blood vessel tube formation. Angiogenesis was determined in vivo using a murine dorsal wound pocket model and quantification of new blood vessel formation after 7 days. We found that all injured patients, irrespective of age, have elevated plasma and fracture hematoma levels of VEGF and PDGF. These elevated cytokine concentrations translate into biologically significant angiogenic effects, in vitro and in vivo. These effects are primarily VEGF mediated and are not dependent on patient age. The biological activity of these growth factors does not diminish with advanced age. Thus skeletal injury does result in local and systemic angiogenic responses whereby angiogenic cytokine availability and activity is preserved in the aged suggesting alternative mechanisms for the development of avascularity in delayed and fracture non-union in the elderly.

[Inhibitory effect of artemin on endotoxin-induced nitric oxide synthesis]

OBJECTIVE

To investigate the effect of Artemin on LPS-induced nitric oxide synthesis in macrophages.

METHOD

1. Nitrite oxide (NO) production of RAW 264.7 cells was induced by LPS or LPS in combination with interferon-gamma (IFN gamma) in the presence or absence of Artemin. The amount of NO in the supernatant of RAW 264.7 cells was detected with Griess reagent. 2. Balb/c mice were injected with Artemin (i.m.) 50 mg.kg-1.d-1 x 3 d, and intraperitoneal macrophages were collected to detect the LPS-induced NO production.

RESULT

LPS 1.0, 0.2 microgram.ml-1 or IFN-gamma 100u + LPS 1.0, 0.2, 0.04 microgram.ml-1 could induced a large amount of NO synthesis of RAW 264.7 cells. Artemin showed a significant inhibitory effect on LPS or IFN-gamma + LPS-induced NO production in a dose dependent manner. After treatment with Artemin, the response of Balb/c mice to LPS was reduced, which was showed by a decrease in NO production of intraperitoneal macrophages induced by LPS.

CONCLUSION

Artemin could reduce LPS-induced production of inflammatory factors resulting in the inhibition of inflammatory effects.

Changing prevalence of hepatitis C virus genotypes: molecular epidemiology and clinical implications in the hepatitis C virus hyperendemic areas and a tertiary referral center in Taiwan

To determine the hepatitis C virus (HCV) genotype distribution in Taiwan and to clarify the relationship between genotype and the pathogenesis of HCV infection, 1,164 subjects positive for serum HCV antibodies and HCV RNA from three HCV hyperendemic areas (Masago, Tzukuan, and Taoyuan) and a tertiary referral center in Taiwan were studied during 1995-1997. HCV genotypes and viral loads were determined using Okamoto's method and branched DNA assay, respectively. Genotype 1b was the most prevalent in Tzukuan (61.9%), Taoyuan (76.9%), and the referral center (47.0%). By contrast, genotype 2a was the major HCV type in Masago (63.5%). Prevalence of genotype 1b positively and that of genotype 2a negatively correlated to age, regardless of study populations (P < 0.01). Based on multivariate analysis, the significant factors associated with the presence of cirrhosis, with or without hepatocellular carcinoma, in chronic hepatitis C patients were genotype 1b and age. In conclusion, these results underline that independent HCV outbreaks continue in HCV hyperendemic areas in Taiwan, concomitant with a changing relative prevalence of HCV genotypes in relation to age. Both the correlation of genotype 1b with age (cohort effect) and intrinsic properties of HCV genotypes are probably responsible for the association between genotype and the pathogenesis of HCV infection.

Phosphorylation of human N-myristoyltransferase by N-myristoylated SRC family tyrosine kinase members

N-Myristoyltransferase (NMT) is an essential eukaryotic enzyme that catalyzes the cotranslational and/or posttranslational transfer of myristate to the amino terminal glycine residue of a number of important proteins especially the non-receptor tyrosine kinases whose activity is important for tumorigenesis. Human NMT was found to be phosphorylated by non-receptor tyrosine kinase family members of Lyn, Fyn and Lck and dephosphorylated by the Ca(2+)/calmodulin-dependent protein phosphatase, calcineurin. Deletion of 149 amino acids from the N-terminal end resulted in the absence of phosphorylation suggesting that the phosphorylation sites are located in the N-terminal end of NMT. Furthermore, a site-directed mutagenesis study indicated that substitution of tyrosine 100 with phenylalanine served NMT as a poor substrate for the Lyn kinase. A synthetic peptide corresponding to the amino-terminal region encompassing tyrosine 100 of NMT served as a good substrate for the Lyn and Fyn kinases. Our studies also indicated that NMT was found to interact with Lyn through its N-terminal end in a phosphorylation-dependent manner. This is the first study demonstrating the cross-talk between NMT and their myristoylated protein substrates in signaling pathways.

[Clinical study on regulatory effect of liandai Capsule on p21ras and mutant p53 protein expression in gastrointestinal neoplasm]

OBJECTIVE

To study the regulatory effect of Liandai Capsule on p21ras and mutant p53 protein expression in gastrointestinal (GI) neoplasm.

METHODS

Forty-five patients of GI neoplasm in middle or advanced stage were enrolled and divided randomly into the treated group and the control group to observe the changes of their serum p21ras and mutant p53 protein expression as well as their quality of life (QOL) before and after treatment.

RESULTS

The content of p21ras and mutant p53 protein expression in the treated group decreased significantly and QOL improved after treatment, P < 0.05 or P < 0.01, while these changes in the control group were not shown.

CONCLUSION

Liandai Capsule has regulatory effect on p21ras and mutant p53 protein expression in GI neoplasm.

Crystal structure of the human CD4 N-terminal two-domain fragment complexed to a class II MHC molecule

The structural basis of the interaction between the CD4 coreceptor and a class II major histocompatibility complex (MHC) is described. The crystal structure of a complex containing the human CD4 N-terminal two-domain fragment and the murine I-A(k) class II MHC molecule with associated peptide (pMHCII) shows that only the "top corner" of the CD4 molecule directly contacts pMHCII. The CD4 Phe-43 side chain extends into a hydrophobic concavity formed by MHC residues from both alpha 2 and beta 2 domains. A ternary model of the CD4-pMHCII-T-cell receptor (TCR) reveals that the complex appears V-shaped with the membrane-proximal pMHCII at the apex. This configuration excludes a direct TCR-CD4 interaction and suggests how TCR and CD4 signaling is coordinated around the antigenic pMHCII complex. Human CD4 binds to HIV gp120 in a manner strikingly similar to the way in which CD4 interacts with pMHCII. Additional contacts between gp120 and CD4 give the CD4-gp120 complex a greater affinity. Thus, ligation of the viral envelope glycoprotein to CD4 occludes the pMHCII-binding site on CD4, contributing to immunodeficiency.

Sonographic features of hepatic adenomas with pathologic correlation

BACKGROUND

We compared the sonographic characteristics of hepatic adenomas with pathologic findings.

METHODS

Information over 10 years was collected on 12 patients (six men, six women; mean age = 47 years) with surgically proven hepatic adenomas. Clinical data, sonographic features, and histopathologic findings were reviewed.

RESULTS

The tumors in males were smaller and simpler than those in women (p < 0.05, Fisher's exact test). Four of the six larger tumors (>5 cm) showed mixed-echoic patterns corresponding with pathologically intratumoral hemorrhage and necrosis. Four homogeneously hypoechoic tumors had less change in tumor composition. Three homogeneously hyperechoic tumors had evident fatty changes inside. One isoechoic tumor had a hypoechoic rim, that correlated mostly to the tumor itself and compressed liver parenchyma. Seven of the 12 tumors had thin fibrous capsules that were not seen on sonography.

CONCLUSION

Hepatic adenomas have variable sonographic appearances depending on changes in the tumor. Hypoechoic, hyperechoic, and mixed-echoic patterns represent simple adenoma, adenoma with fatty metamorphosis, and hemorrhagic necrosis, respectively, in tumors.

Inosine attenuates tourniquet-induced skeletal muscle reperfusion injury

BACKGROUND

Adenosine attenuates skeletal muscle reperfusion injury, but its short half-life in vivo limits potential therapeutic benefits. The aim of this study was to ascertain whether inosine, a stable adenosine metabolite, modulates skeletal muscle reperfusion injury.

MATERIALS AND METHODS

C57BL/6 mice were randomized (8-10 per group) to six groups: time controls; inosine (100 mg/kg) before anesthesia; 2 h of bilateral tourniquet hindlimb ischemia; I/R (2 h of bilateral tourniquet hindlimb ischemia, 3 h of reperfusion); inosine (100 mg/kg) before I/R; drug vehicle before I/R. Serum tumor necrosis factor (TNF)-alpha and macrophage inflammatory protein (MIP)-2 were measured before ischemia and at the end of reperfusion. Tissue edema was determined by wet/dry weight ratios. Tissue leucosequestration was assessed by the myeloperoxidase (MPO) content.

RESULTS

At the end of reperfusion, inosine pretreatment resulted in lower MPO levels in muscle (P = 0.02) and lung (P = 0.0002) than saline pretreatment. Similarly, muscle (P = 0.04) and lung (P = 0.02) wet/dry ratios were significantly reduced with inosine but not with saline pretreatment. At the end of reperfusion, serum proinflammatory cytokine levels (TNF-alpha and MIP-2) were significantly reduced (P < 0.05) compared to preischemia levels following inosine pretreatment but not saline pretreatment. Ischemia alone did not alter any of the parameters assessed.

CONCLUSIONS

These findings demonstrate that pretreatment with inosine attenuates the local and systemic proinflammatory responses associated with skeletal muscle reperfusion injury.

The effect of lidocaine on neutrophil respiratory burst during induction of general anaesthesia and tracheal intubation

BACKGROUND AND OBJECTIVE

Respiratory burst is an essential component of the neutrophil's biocidal function. In vitro, sodium thiopental, isoflurane and lidocaine each inhibit neutrophil respiratory burst. The objectives of this study were (a) to determine the effect of a standard clinical induction/tracheal intubation sequence on neutrophil respiratory burst and (b) to determine the effect of intravenous lidocaine administration during induction of anaesthesia on neutrophil respiratory burst.

METHODS

Twenty ASA I and II patients, aged 18-60 years, undergoing elective surgery were studied. After induction of anaesthesia [fentanyl (2 microg kg-1), thiopental (4-6 mg kg-1), isoflurane (end-tidal concentration 0.5-1.5%) in nitrous oxide (66%) and oxygen], patients randomly received either lidocaine 1.5 mg kg-1 (group L) or 0.9% saline (group S) prior to tracheal intubation. Neutrophil respiratory burst was measured immediately prior to induction of anaesthesia, immediately before and 1 and 5 min after lidocaine/saline.

RESULTS

Neutrophil respiratory burst decreased significantly after induction of anaesthesia in both groups [87.4 +/- 8.2% (group L) and 88.5 +/- 13.4% (group S) of preinduction level (P < 0.01 both groups)]. After intravenous lidocaine (but not saline) administration, neutrophil respiratory burst returned towards preinduction levels, both before (97.1 +/- 23.6%) and after (94.4 +/- 16.6%) tracheal intubation.

CONCLUSION

Induction of anaesthesia and tracheal intubation using thiopentone and isoflurane, inhibit neutrophil respiratory burst. This effect may be diminished by the administration of lidocaine.

Structural Insights into Cdk5 activation by a neuronal Cdk5 activator

Although Cdk5 shows high sequence identity to Cdk1 and Cdk2, it can be fully activated by its neuronal activators p35/p25(nck5a) and p39(nck5ai) in a phosphorylation-independent manner. To understand structural basis of the Cdk5/p25(nck5a) activation, the complex is modelled to assume either an obstructed or an opened conformation based on X-ray structures of the unphosphorylated or the phosphorylated Cdk2/cyclin A complex, respectively. Comparison and analysis of the two models, along with mutagenesis studies of p25(nck5a), suggest that the opened form represents more closely the structure of active Cdk5/p25(nck5a). The results provide a rationale basis for understanding the phosphorylation-independent activation of Cdk5/p25(nck5a).

Pharmacokinetics of sertraline in relation to genetic polymorphism of CYP2C19

OBJECTIVE

Our objective was to evaluate the relationship between the disposition of sertraline and the presence of the CYP2C19 gene and to define the contribution of cytochrome P450 2C19 (CYP2C19) to sertraline N-demethylation.

METHODS

A single oral 100-mg dose of sertraline was administered to 6 subjects who were extensive metabolizers and 6 subjects who were poor metabolizers recruited from 77 healthy Chinese volunteers whose genotypes were predetermined by polymerase chain reaction-based amplification, followed by restriction fragment length polymorphism analysis. Phenotypes were determined by use of the omeprazole metabolic rate. The plasma concentrations of sertraline and desmethylsertraline were determined by gas chromatography with electron-capture detection.

RESULTS

Six poor metabolizers with m1 mutation had area under the plasma concentration versus time curve (AUC(0-infinity)) values (983.6 +/- 199.3 microg x h/L versus 697.6 +/- 133.0 microg x h/L; P <.05) and terminal elimination half-life values of sertraline (35.5 +/- 5.6 hours versus 23.5 +/- 4.4 hours; P <.01) that were significantly higher than the values in 6 extensive metabolizers who were either homozygous or heterozygous for CYP2C19*1. The oral clearance of sertraline in poor metabolizers (105.3 +/- 19.4 L/h) was significantly lower than that of extensive metabolizers (148.4 +/- 28.6 L/h). The area under the concentration-time curve from 0 to 144 hours and the maximum plasma concentration of desmethylsertraline in poor metabolizers were significantly lower than the values of extensive metabolizers (627.6 +/- 203.8 microg x h/L versus 972.1 +/- 270.3 microg x h/L; P <.05; and 23.6 +/- 6.5 nmol/L versus 32.4 +/- 8.2 nmol/L; P <.01; respectively).

CONCLUSIONS

The polymorphic CYP2C19 appears to be a major enzyme involved in the N-demethylation of sertraline, and both extensive and poor metabolizers had marked differences in the disposition of sertraline.

Pregrowth-desiccation: a simple and efficient procedure for the cryopreservation of rice (Oryza sativa L.) embryogenic suspension cells

Rice embryogenic suspension cells were successfully cryopreserved by a pregrowth-desiccation procedure. Cells were precultured in liquid AA medium containing 0.175 mol/L sucrose for 3 d and then in liquid AA medium containing 0.4 mol/L sorbitol for 1 d. After air-drying for about 20 h to a water content of 10%, the cells were placed into cryotubes and quenched into liquid nitrogen. Using this pregrowth-desiccation procedure, a survival rate of 96+/-6% (TTC reduction assay) or 100% (cell clump regrowth) was achieved. Cryostored cells revived very quickly during the recovery culture and they retained the ability to regenerate fertile plants. In conclusion, air-drying, a method usually employed in cryopreservation of seeds or shoot tips, can be used as a simple and efficient procedure for the cryopreservation of precultured rice suspension cells.

Upregulation of Fas-Fas-L (CD95/CD95L)-mediated epithelial apoptosis--a putative role in pouchitis?

INTRODUCTION

Ileal pouch-anal anastomosis (IPAA) remains the gold standard for patients with refractory ulcerative colitis. Pouchitis causes considerable morbidity in 40% of patients with IPAA. This study examined the role of increased epithelial apoptosis in the etiology of pouchitis.

METHODS

Following ethical approval pouch biopsies taken from patients with a history of pouchitis were compared with age-matched controls from patients who were pouchitis free. Apoptosis was detected immunohistochemically using a monoclonal antibody (M30) and terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin end labeling (TUNEL). Villous atrophy was assessed histologically and correlated with levels of apoptosis. Epithelial Fas-ligand (L) was also assessed immunohistochemically.

RESULTS

A significant increase in TUNEL staining was seen at the epithelial but not at the lamina propria level for known pouchitis patients versus controls (0.091 vs 0.035; P < 0.01). Similarly, epithelial M30 immunoreactivity (0.225 vs 0.082; P < 0.05) and villous atrophy (0.035 vs 0.10; P < 0.05) were significantly increased in pouches with previous pouchitis when compared with normal pouches. Upregulation of Fas-L expression was characteristic of this epithelium. Mononuclear cells were strongly positive for Fas-L. Increased epithelial levels of apoptosis correlated with increased levels of villous atrophy.

CONCLUSIONS

Our data suggest a role for elevated Fas-Fas-L (CD95-CD95L)-mediated epithelial apoptosis in the etiology of pouchitis. Increased levels of villous atrophy may result from increased apoptosis and thereby predispose to infection by otherwise apathogenic organisms.

Activated human neutrophils release hepatocyte growth factor/scatter factor

BACKGROUND

Hepatocyte growth factor or scatter factor (HGF/SF) is a pleiotropic cytokine that has potent angiogenic properties. We have previously demonstrated that neutrophils (PMN) are directly angiogenic by releasing vascular endothelial growth factor (VEGF). We hypothesized that the acute inflammatory response can stimulate PMN to release HGF.

AIMS

To examine the effects of inflammatory mediators on PMN HGF release and the effect of recombinant human HGF (rhHGF) on PMN adhesion receptor expression and PMN VEGF release.

METHODS

In the first experiment, PMN were isolated from healthy volunteers and stimulated with tumour necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), interleukin-8 (IL-8), and formyl methionyl-leucyl-phenylalanine (fMLP). Culture supernatants were assayed for HGF using ELISA. In the second experiment, PMN were lysed to measure total HGF release and HGF expression in the PMN was detected by Western immunoblotting. Finally, PMN were stimulated with rhHGF. PMN CD 11a, CD 11b, and CD 18 receptor expression and VEGF release was measured using flow cytometry and ELISA respectively.

RESULTS

TNF-alpha, LPS and fMLP stimulation resulted in significantly increased release of PMN HGF (755+/-216, 484+/-221 and 565+/-278 pg/ml, respectively) compared to controls (118+/-42 pg/ml). IL-8 had no effect. Total HGF release following cell lysis and Western blot suggests that HGF is released from intracellular stores. Recombinant human HGF did not alter PMN adhesion receptor expression and had no effect on PMN VEGF release.

CONCLUSIONS

This study demonstrates that pro-inflammatory mediators can stimulate HGF release from a PMN intracellular store and that activated PMN in addition to secreting VEGF have further angiogenic potential by releasing HGF.

Role of hypothalamic-pituitary axis in morphine-induced alteration in thymic cell distribution using mu-opioid receptor knockout mice

Mu-opioid receptor knockout mice (MORKO), were used to address two questions: (1) if morphine induced decrease in thymic weight and cell distribution is mediated by the mu-opioid receptor and (2) the role of corticosteroids in morphine mediated alteration in thymic cell distribution. Our result show that morphine mediated increase in plasma corticosterone is mediated by the mu-opioid receptor since morphine at doses as high as 25 mg/kg-body weight does not increase plasma corticosterone levels in the MORKO. In addition, we have also shown that morphine treatment results in the differentiation of CD4+CD8+ (double positive cells) to single positive CD4+ cells while dexamethasone treatment results in the deletion of CD4+CD8+ (double positive) cells.

Calcium-calmodulin signalling pathway up-regulates glutamatergic synaptic function in non-pyramidal, fast spiking rat hippocampal CA1 neurons

1. The role of Ca(2+)-calmodulin (CaM) signalling cascades in modulating glutamatergic synaptic transmission on CA1 non-pyramidal fast-spiking neurons was investigated using whole-cell recording and perfusion in rat hippocampal slices. 2. Paired stimuli (PS), consisting of postsynaptic depolarization to 0 mV and presynaptic stimulation at 1 Hz for 30 s, enhanced excitatory postsynaptic currents (EPSCs) on non-pyramidal neurons in the stratum pyramidale (SP). The potentiation was reduced by the extracellular application of D-amino-5-phosphonovaleric acid (DAP-5, 40 microM), and blocked by the postsynaptic perfusion of 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (BAPTA, 10 mM), a CaM-binding peptide (100 microM) or CaMKII (281-301) (an autoinhibitory peptide of CaM-dependent protein kinases, 100 microM). 3. The application of adenophostin, an agonist of inositol trisphosphate receptors (IP(3)Rs) that evokes Ca(2+) release, into SP non-pyramidal neurons via the patch pipette (1 microM) enhanced EPSCs and occluded PS-induced synaptic potentiation. The co-application of BAPTA (10 mM) with adenophostin blocked synaptic potentiation. In addition, Ca(2+)-CaM (40:10 microM) induced synaptic potentiation, which occluded PS-induced potentiation and was attenuated by introducing CaMKII (281-301) (100 microM). EPSCs were sensitive to an antagonist of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR). 4. Application of Ca(2+)-CaM into SP non-pyramidal neurons induced the emergence of AMPAR-mediated EPSCs that were not evoked by low stimulus intensity before perfusion. Ca(2+)-CaM also increased the amplitude and frequency of spontaneous EPSCs. A scavenger of nitric oxide, carboxy-PTIO (30 microM in slice-perfusion solution), did not affect these increases in sEPSCs. 5. The magnitude of PS-, adenophostin- or Ca(2+)-CaM-induced synaptic potentiation in SP non-pyramidal neurons increased during postnatal development. 6. These results indicate that Ca(2+)-CaM signalling pathways in CA1 SP non-pyramidal neurons up-regulate glutamatergic synaptic transmission probably through the conversion of inactive-to-active synapses.

Sonographic features of xanthogranulomatous pyelonephritis

PURPOSE

The purpose of this study was to describe the various sonographic features of xanthogranulomatous pyelonephritis (XGP).

METHODS

We retrospectively reviewed the CT, sonographic, and medical records of patients diagnosed with XGP from January 1981 to December 1998. Twenty-seven patients for whom XGP was histopathologically confirmed were included in the study. There were 12 men and 15 women, with an age range of 21-86 years (mean, 57 years). All patients had undergone sonography of the kidneys. The renal size, shape, and outline were recorded. The presence of perinephric fluid accumulation, of obstructive uropathy, or of internal echoes in the dilated collecting system and the echotexture of the renal parenchyma were documented.

RESULTS

We categorized the XGP into 4 groups on the basis of the sonographic features: (1) diffuse hydronephrotic, 12 patients (44%); (2) diffuse parenchymal, 9 patients (33%); (3) diffuse contracted, 4 patients (15%); and (4) segmental or focal, 2 patients (7%). A localized perinephric fluid collection was present in 4 patients (15%). The preoperative sonographic diagnoses were pyonephrosis (n = 14, 52%), renal pelvic tumor with possible associated infection (n = 5, 19%), renal parenchymal mass (n = 2, 7%), hydronephrosis (n = 2, 7%), and chronic pyelonephritis with renal atrophy (n = 4, 15%). XGP was considered a possible diagnosis in only 11 patients (41%).

CONCLUSIONS

XGP has no specific sonographic features but is suggested by parenchymal thinning and hydronephrosis, sonographic signs of chronic obstructive uropathy caused by stones; echoes in the dilated collecting system; and a perinephric fluid collection. CT, needle biopsy, or both are recommended to further evaluate and confirm sonographically suspected XGP.

Proinflammatory effects of bacterial lipoprotein on human neutrophil activation status, function and cytotoxic potential in vitro

Bacterial lipoprotein (BLP) is the most abundant protein in gram-negative bacterial cell walls, heavily outweighing lipopolysaccharide (LPS). Herein we present findings demonstrating the potent in vitro effects of BLP on neutrophil (PMN) activation status, function, and capacity to transmigrate an endothelial monolayer. PMNs are the principal effectors of the initial host response to injury or infection and constitute a significant threat to invading bacterial pathogens. The systemic inflammatory response syndrome (SIRS) is characterised by significant host tissue injury mediated, in part, by uncontrolled regulation of PMN cytotoxic activity. We found that BLP-activated human PMN as evidenced by increased CD11b/CD18 (Mac-1) expression. Up-regulation of PMN Mac-1 in response to BLP occurred independently of membrane-bound CD14 (mCD14). A similar up-regulation of intercellular adhesion molecule-1 (ICAM-1) on endothelial cells was observed whilst E-Selectin expression was unaffected. PMN transmigration across a human umbilical vein endothelial cell (HUVEC) monolayer was markedly increased after treating either PMN's or HUVEC independently with BLP. This increased transmigration did not occur as a result of any direct effect of BLP on HUVEC monolayer permeability, assessed objectively using the passage of FITC-labeled Dextran-70. BLP primed PMN for enhanced respiratory burst and superoxide anion production in response to PMA, but did not influence phagocytosis of opsonized Escherichia coli. BLP far exceeds LPS as a gram-negative bacterial wall component, these findings therefore implicate BLP as an additional putative mediator of SIRS arising from gram-negative infection.

One-stage correction of neglected developmental dysplasia of the hip by open reduction and pemberton osteotomy

BACKGROUND AND PURPOSE

Pemberton osteotomy is commonly used for correction of hip-dysplasia. Its application in treating hip dislocation is rarely reported. The purpose of this study was to determine the efficacy of one-stage open reduction and Pemberton osteotomy of neglected developmental dysplasia of the hip (DDH).

METHODS

We retrospectively reviewed the clinical and radiographic results of one-stage total correction in 75 patients with neglected DDH (86 hips) from 1984 through 1996. Sixty-nine patients (77 hips) aged 13 to 76 months (mean, 21.5 mo) underwent open reduction, Pemberton osteotomy, and hip spica for 8 weeks. Seven patients (9 hips) aged 29 to 73 months (mean, 46.6 mo) underwent additional femoral shortening (another hip in one bilaterally involved patient underwent only open reduction and Pemberton osteotomy).

RESULTS

Acetabular index improved markedly from 40.4 degrees (range, 25-60 degrees) preoperatively to 16.2 degrees (range, 0-30 degrees) postoperatively. Complications included redislocation in four patients (4 hips) and avascular necrosis in three patients (3 hips). Reoperation was performed in four patients (4 hips). All patients were followed up for at least 3 years. By Severin's classification, all operated hips had excellent (18) or good (68) final radiographic results. The functional results, evaluated by McKay's criteria, were also excellent (52 patients/60 hips) and good (23 patients/26 hips).

CONCLUSIONS

Neglected DDH was safely and effectively treated by open reduction, Pemberton osteotomy, and optional femoral shortening with limited complications.

Role of taurine in preventing acetaminophen-induced hepatic injury in the rat

Acetaminophen overdose causes acute liver injury in both humans and animals. This study was designed to investigate the potential role of the conditionally essential amino acid taurine in preventing acetaminophen-induced hepatotoxicity. Male Sprague-Dawley rats were administered acetaminophen (800 mg/kg) intraperitoneally. Taurine (200 mg/kg) was given 12 h before, at the time of, and 1 or 2 h after acetaminophen injection. Acetaminophen treatment increased the plasma levels of aspartate transaminase, alanine aminotransferase, and alkaline phosphatase and caused hepatic DNA fragmentation and hepatocyte necrosis. Taurine administered before, simultaneously with, or 1 h after acetaminophen resulted in significant improvement in hepatic injury as represented by decrease of hepatocellular enzyme release and attenuation of hepatocyte apoptosis and necrosis, and this correlated with taurine-mediated attenuation of hepatic lipid peroxidation. These results indicate that taurine possesses prophylactic and therapeutic effects in acetaminophen-induced hepatic injury.

[Study on the metabolism of psuedo-ginsenoside F11 in rats]

AIM

To study the metabolic pathways of psuedo-ginsenoside F11 in rats.

METHODS

By use of the prep-TLC, the metabolites were isolated.

RESULTS

From the feces, three metabolites, psuedo-ginsenoside-RT5, ocotillol, and a new compound, F-3-1 (44) were isolated and identified by means of NMR evidence. But, such metabolites were found from neither the bile nor the urine of the rat. F-3-1 was identified as 6-O-alpha-L-rhamnopyranosyl-(1-2)-beta-D-glucopyranosyl-(20S,23S,24R)- dammar-20(24)-epoxy-3 beta, 6 alpha, 12 beta, 23,25-pentanol.

CONCLUSION

Psuedo-ginsenoside-F11 can not be metabolized in the rat liver, but can be metabolized in the large intestine of the rat.

Determination of three nitroimidazole residues in poultry meat by gas chromatography with nitrogen-phosphorus detection

A method was developed for the determination of the nitroimidazole compounds dimetridazole (DMZ), ronidazole (RNZ) and metronidazole (MNZ) by gas chromatography with nitrogen phosphorus detection. Nitroimidazole compounds were extracted with acetonitrile, followed by acidification using acetic acid and cleanup using strong cation-exchange (SCX) SPE column. Validation in chicken muscle fortified at a concentration of 5 microg/kg gave mean recoveries of 85% DMZ, 90% RNZ, 80% MNZ with RSDs of 13.0, 14.3, 11.2%, respectively (n=6). The method is suitable for statutory residue testing and is used as a quick screening method in the National Residue Surveillance Plan in China.

Flash echo gray scale imaging with subtraction in assessment of small hepatocellular carcinoma treated with percutaneous ethanol injection: preliminary report

OBJECTIVE

To assess the therapeutic effect of percutaneous ethanol injection on small hepatocellular carcinoma by using a flash echo imaging system, a newly developed technique for detecting echoes from microbubble contrast agents more efficiently.

METHODS

Six patients with 7 small nodular hepatocellular carcinomas, proved by fine-needle aspiration cytologic or pathologic examination, were included. Percutaneous ethanol injection was performed until there was no intratumoral color signal on conventional color and power Doppler ultrasonography. A bubble contrast agent was then injected, and flash echo imaging in the subtraction mode was performed for assessment of the therapeutic effect. Dynamic computed tomography, magnetic resonance imaging, and hepatic angiography were also used for evaluation of the therapeutic effect.

RESULTS

Five tumors had perfusion defects that were equal in size to or larger than the tumors. No tumor stain was shown on hepatic angiography. Two tumors had partial perfusion defects. Viable tumors were confirmed by tumor resection in 1 case and cytologic examination in the other.

CONCLUSIONS

Our preliminary results show that flash echo imaging with subtraction has potential value in evaluation of the therapeutic effect of percutaneous ethanol injection on small hepatocellular carcinoma.

Tumor cell adhesion to endothelial cells is increased by endotoxin via an upregulation of beta-1 integrin expression

BACKGROUND

Recent studies have demonstrated that metastatic disease develops from tumor cells that adhere to endothelial cells and proliferate intravascularly. The beta-1 integrin family and its ligand laminin have been shown to be important in tumor-to-endothelial cell adhesion. Lipopolysaccharide (LPS) has been implicated in the increased metastatic tumor growth that is seen postoperatively. We postulated that LPS increases tumor cell expression of beta-1 integrins and that this leads to increased adhesion.

METHODS

The human metastatic colon cancer cell line LS174T was labeled with an enhanced green fluorescent protein (eGFP) using retroviral transfection. Cell cultures were treated with LPS for 1, 2, and 4 h (n = 6 each) and were subsequently cocultured for 30 or 120 min with confluent human umbilical vein endothelial cells (HUVECs), to allow adherence. Adherent tumor cells were counted using fluorescence microscopy. These experiments were carried out in the presence or absence of a functional blocking beta-1 integrin monoclonal antibody (4B4). Expression of beta-1 integrin and laminin on tumor and HUVECs was assessed using flow cytometric analysis. Tumor cell NF-kappaB activation after incubation with LPS was measured.

RESULTS

Tumor cell and HUVEC beta-1 integrin expression and HUVEC expression of laminin were significantly (P < 0.05) enhanced after incubation with LPS. Tumor cell adhesion to HUVECs was significantly increased. Addition of the beta-1 integrin blocking antibody reduced tumor cell adhesion to control levels. LPS increased tumor cell NF-kappaB activation.

CONCLUSIONS

Exposure to LPS increases tumor cell adhesion to the endothelium through a beta-1 integrin-mediated pathway that is NF-kappaB dependent. This may provide a target for immunotherapy directed at reducing postoperative metastatic tumor growth.

The dual effect of antifreeze protein on cryopreservation of rice (Oryza sativa l.) embryogenic suspension cells

The effects of fish antifreeze protein AFP-I on cryopreservation of rice suspension cells by three different protocols were investigated. During the two-step method, AFP-I at 0.01 mg/ml significantly lowered the viability of both precultured and non-precultured cells. During the vitrification method, AFP-I at 0.2 mg/ml improved the viability of suboptimally thawed cells; however, much higher doses of this protein (10mg/ml) attenuated the cell viability. During rapid freezing of rice cells in the solutions with relatively high (but non-vitrifying) concentrations of cryoprotectant, AFP-I displayed protective action in the higher concentrated cryoprotectants and detrimental effect in more dilute ones. Taken together, it was concluded that, depending upon a number of factors discussed in the present paper, both positive effect and negative effect could be observed during application of AFP to cryopreservation of rice cells. The possible mechanism of this dual character was discussed.

[The development of the multifunctional cephalostat and its applications in anesthesia]

The multifunctional cephalostat is able to hold the patients' head better and firmly at prone position after tracheal intubation under general anesthesia According to the size of patients head, the anesthetist can properly adjust the distance of the malor holder and the distance between the superciliary ridge and the lower jaw, and fix the two tempora to prevent the head swaying. So this instrument greatly facilitates the anesthesia managements.

Cdk5 is involved in neuregulin-induced AChR expression at the neuromuscular junction

Here we describe an important involvement of Cdk5/p35 in regulating the gene expression of acetylcholine receptor (AChR) at the neuromuscular synapse. Cdk5 and p35 were prominently expressed in embryonic muscle, and concentrated at the neuromuscular junction in adulthood. Neuregulin increased the p35-associated Cdk5 kinase activity in the membrane fraction of cultured C2C12 myotubes. Co-immunoprecipitation studies revealed the association between Cdk5, p35 and ErbB receptors in muscle and cultured myotubes. Inhibition of Cdk5 activity not only blocked the NRG-induced AChR transcription, but also attenuated ErbB activation in cultured myotubes. In light of our finding that overexpression of p35 alone led to an increase in AChR promoter activity in muscle, Cdk5 activation is sufficient to mediate the up-regulation of AChR gene expression. Taken together, these results reveal the unexpected involvement of Cdk5/p35 in neuregulin signaling at the neuromuscular synapse.

Human neutrophils facilitate tumor cell transendothelial migration

Tumor cell extravasation plays a key role in tumor metastasis. However, the precise mechanisms by which tumor cells migrate through normal vascular endothelium remain unclear. In this study, using an in vitro transendothelial migration model, we show that human polymorphonuclear neutrophils (PMN) assist the human breast tumor cell line MDA-MB-231 to cross the endothelial barrier. We found that tumor-conditioned medium (TCM) downregulated PMN cytocidal function, delayed PMN apoptosis, and concomitantly upregulated PMN adhesion molecule expression. These PMN treated with TCM attached to tumor cells and facilitated tumor cell migration through different endothelial monolayers. In contrast, MDA-MB-231 cells alone did not transmigrate. FACScan analysis revealed that these tumor cells expressed high levels of intercellular adhesion molecule-1 (ICAM-1) but did not express CD11a, CD11b, or CD18. Blockage of CD11b and CD18 on PMN and of ICAM-1 on MDA-MB-231 cells significantly attenuated TCM-treated, PMN-mediated tumor cell migration. These tumor cells still possessed the ability to proliferate after PMN-assisted transmigration. These results indicate that TCM-treated PMN may serve as a carrier to assist tumor cell transendothelial migration and suggest that tumor cells can exploit PMN and alter their function to facilitate their extravasation.

Adenosine inhibits neutrophil vascular endothelial growth factor release and transendothelial migration via A2B receptor activation

The effects of adenosine on neutrophil (polymorphonuclear neutrophils; PMN)-directed changes in vascular permeability are poorly characterized. This study investigated whether adenosine modulates activated PMN vascular endothelial growth factor (vascular permeability factor; VEGF) release and transendothelial migration. PMN activated with tumour necrosis factor-alpha (TNF-alpha, 10 ng/mL) were incubated with adenosine and its receptor-specific analogues. Culture supernatants were assayed for VEGF. PMN transendothelial migration across human umbilical vein endothelial cell (HUVEC) monolayers was assessed in vitro. Adhesion molecule receptor expression was assessed flow cytometrically. Adenosine and some of its receptor-specific analogues dose-dependently inhibited activated PMN VEGF release. The rank order of potency was consistent with the affinity profile of human A2B receptors. The inhibitory effect of adenosine was reversed by 3,7-dimethyl-1-propargylxanthine, an A2 receptor antagonist. Adenosine (100 microM) or the A2B receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA, 100 microM) significantly reduced PMN transendothelial migration. However, expression of activated PMN beta2 integrins and HUVEC ICAM-1 were not significantly altered by adenosine or NECA. Adenosine attenuates human PMN VEGF release and transendothelial migration via the A2B receptor. This provides a novel target for the modulation of PMN-directed vascular hyperpermeability in conditions such as the capillary leak syndrome.

Contractility affects stress fiber remodeling and reorientation of endothelial cells subjected to cyclic mechanical stretching

We studied the effect of contractility on stress fiber remodeling and orientation response of human aortic endothelial cells subjected to cyclic mechanical stretching. The cells were grown on silicone membranes subjected to 10% cyclic pure uniaxial stretching in the presence or absence of 2,3 butanedione monoxime (BDM), a proven inhibitor of cellular contractility. It was found that treatment of the cells with BDM (40 mM) abolished stress fibers and blocked cell reorientation in response to cyclic stretching, indicating that contractility is required for these two cellular responses. When cells were stretched in the presence of N-acetylcysteine (NAG, 20 mM), a hydrogen peroxide (H2O2) scavenger, stress fibers were still formed and the cells reoriented--but more slowly. Specifically, compared with untreated cells, NAG treated cells after 0.5, 1, and 3 h of 10% stretching had significantly (p<0.005) less skewed orientation distributions than those of untreated cells. After the cells were treated with both NAG (20 mM) and nordihydroguaiaretic acid (NDGA, 50 microM), another antioxidant, however, stress fibers were abolished and cell reorientation was completely blocked. These results indicate that reactive oxygen species (ROS), including H2O2, affect stress fiber remodeling and reorientation of endothelial cells in response to cyclic stretching. We suggest that the effect of ROS on stress fiber remodeling and cell reorientation is due to the ability of ROS to regulate cellular contractility, which is crucial for these cellular responses.

Ventilator-associated pneumonia with circuit changes every 2 days versus every week

BACKGROUND

Frequent ventilator circuit changes are expensive and sometimes unnecessary. Following the worldwide trend to lengthen the intervals for ventilator circuit change from 2 days to 1 week, this study aims to assure that low rate of ventilator-associated pneumonia (VAP) can be maintained with cost containment.

METHODS

Ventilator circuits were routinely changed every 7 days in the study period for 2 years and every 2 days during the historical control period of another 2 years. Pediatric patients (age less than 15 years) were not included. Nosocomial pneumonia was diagnosed by the criteria of the Centers of Disease Control and Prevention (CDC) of the United States (US). VAP was identified by combining and comparing 2 databases from the Respiratory Therapy Department and the Infection Control Unit of our hospital.

RESULTS

In the study group, 225 episodes of pneumonias were observed in 7,068 patients and 87,338 ventilator days. The rate of VAP was 2.58 per 1,000 ventilator days. There were 174 episodes of pneumonia in 6,213 patients and 65,467 ventilator days of the control group. The rate of VAP was 2.66 per 1,000 ventilator days. The difference between both groups was not significant (p = 0.803). Yet, the cost curbed was around 80,000 US dollars per year.

CONCLUSIONS

Extending ventilator circuit change interval from 2 days to 7 days do not increase the risk for VAP, but the cost savings for labor and supply are substantial.

[Poteintation of vincristine-induced apoptosis by tetrandrine, neferine and dauricine in the human mammary MCF-7 multidrug-resistant cells]

AIM

To investigate the poteintation of vincristine-induecd apoptosis by tetrandrine, neferine and dauricine isolated from Chinese medicinal plants in the human mammary MCF-7 multidrug resistant cells.

METHODS

The apoptotic cells were detected by fluorescent staining of a combination of Hoechst 33342 and propidium iodide (PI), flow cytometry and agarose electrophoresis.

RESULTS

The apoptotic cells induced by vincristine alone accounted for about 10% of all the cancer cells, while the percentage of apoptotic cells induced by a combination of vincristine with tetrandrine, neferine, or dauricine was found to be significantly higher than that by vincristine alone, and their reversal effects were positively correlated with the drug concentration and the exposure time. In addition, tetrandrine was shown to be the most potent in the reversal efficacy among the three compounds to be tested for apoptosis in vitro.

CONCLUSION

Tetrandrine, neferine and dauricine showed obvious potenitiation of vincristine-induced apoptosis in the human mammary MCF-7 multidrug-resistant cells.

Sodium hyaluronate enhances colorectal tumour cell metastatic potential in vitro and in vivo

BACKGROUND

Sodium hyaluronate has been used intraperitoneally to prevent postoperative adhesions. However, the effect of sodium hyaluronate on tumour growth and metastasis in vitro and in vivo is still unknown.

METHODS

Human colorectal tumour cell lines SW480, SW620 and SW707 were treated with sodium hyaluronate (10-500 microg/ml) and carboxymethylcellulose (0.125-1 per cent), and tumour cell proliferation and motility were determined in vitro. For the in vivo experiments male BD IX rats were randomized to a sodium hyaluronate group (n = 11; intraperitoneal administration of 0.5 x 10(6) DHD/K12 tumour cells and 5 ml 0.4 per cent sodium hyaluronate) or a phosphate-buffered saline group (n = 11; 0.5 x 10(6) DHD/K12 tumour cells and 5 ml phosphate-buffered saline intraperitoneally). Four weeks later the intraperitoneal tumour load was visualized directly.

RESULTS

In vitro sodium hyaluronate increased tumour cell proliferation and motility significantly. Sodium hyaluronate-induced tumour cell motility appeared to be CD44 receptor dependent, whereas sodium hyaluronate-induced tumour cell proliferation was CD44 receptor independent. In vivo there was a significantly higher total tumour nodule count in the peritoneal cavity of the sodium hyaluronate-treated group compared with the control (P = 0.016).

CONCLUSION

Sodium hyaluronate enhances tumour metastatic potential in vitro and in vivo, which suggests that use of sodium hyaluronate to prevent adhesions in colorectal cancer surgery may also potentiate intraperitoneal tumour growth. Presented to the Patey Prize Session of the Surgical Research Society and the annual scientific meeting of the Association of Surgeons of Great Britain and Ireland, Brighton, UK, 4-7 May 1999

[Relation of hypertension to diabetic nephropathy in patients with non-insulin-dependent diabetes mellitus--a pair-matched case-control study]

OBJECTIVE

The study aimed to assess the role of hypertension in the cause of nephropathy in patients with NIDDM.

METHODS

A retrospective analysis was done on two groups of non-insulin-dependent diabetes mellitus (NIDDM) patients, one group without proteinuria (< 300 mg/24 h, n = 106) and the other group with proteinuria (> or = 500 mg/24 h, n = 106). The groups were matched by age (< or = +/- 3) years, sex, race, and resident place. Some information of these subjects including demographic, history of disease, family history of diseases, life and behavior style variables were obtained by questionnaire, some variables were measured including systolic blood pressure(SBP), diastolic blood pressure(DBP), fasting blood glucose, and quantity of protein in 24 h urine. Finally the conditional logistic regression analysis was done.

RESULTS

Some factors were independently associated with the occurrence risk of diabetic nephropathy (DN) associated history of hypertension, longer duration of hypertension, higher levels of the past highest SBP and DBP. Their corresponding odd ratios(OR) with 95% confidence intervals(CI) were 2.00(1.17-3.43), 1.25(1.08-1.46), 1.38(1.15-1.66), and 1.33(1.09-1.62) respectively. But family history of hypertension was not significantly associated with the development of DN. When the above-mentioned relations were adjusted by some relevant confounding factors, the associations were still present.

CONCLUSIONS

History and longer duration of hypertension, history of the highest SBP and DBP are independent risk factors for DN.

Efficacy trial of Vi polysaccharide vaccine against typhoid fever in south-western China

OBJECTIVE

To test the efficacy of locally produced Vi vaccine over a time period of longer than one year.

METHODS

A double-blinded, randomized field trial was performed in Guangxi Zhuang Autonomous Region in south-western China, using 30 micrograms doses of locally produced Vi. Enrolled subjects were 3-50 years of age, although the majority (92%) were school-aged children, who have the highest rate of typhoid fever in this setting. A total of 131,271 people were systematically allocated a single dose of 30 micrograms of Vi polysaccharide or saline placebo. The study population was followed for 19 months, with passive surveillance conducted in the Ministry of Health and the Regional Health and Anti-epidemic Centre (HAEC). Clinically suspected cases of typhoid fever were confirmed by blood culture, or by serological reaction with O-antigen (Widal tests).

FINDINGS

After 19 months, there were 23 culture-confirmed cases of typhoid fever in the placebo group versus 7 cases in the Vi group (Protective efficacy (PE) = 69%; 95% CI = 28%, 87%). Most of the isolates were from school-aged children: 22 cases in the placebo group versus 6 in the Vi group (PE = 72%; 95% CI = 32%, 82%). No serious post-injection reactions were observed. The locally produced Vi polysaccharide vaccine showed levels of protective efficacy similar to those for Vi vaccine produced in industrial countries.

CONCLUSION

The slightly higher dose of vaccine did not seem to alter efficacy significantly in China.

Triterpenoid saponins from leaves and stems of Panax quinquefolium L

In the chemical investigation on the saponin composition of leaves and stems of Panax quinquefolium L., two new minor dammarane saponins, quinquenoside L1 (1) and L2 (2) have been isolated. By means of physico-chemical evidences and spectral analysis their structures were established as 3-O-[beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-dammara-23,25-diene-3beta, 12beta, 20(S)-triol (1) and 3-O-[beta-D-glucopyranosyl-(1-2)-beta-D-glucopyranosyl]-20-O-beta-D-glucopyranosyl-(24Z)-dammar-24-ene-3beta, 12beta, 20(S), 26-tetraol (2).

Ethanol inhibits cytokine-induced iNOS and sPLA2 in immortalized astrocytes: evidence for posttranscriptional site of ethanol action

Chronic and excessive ethanol consumption is known to alter neuron and glial cell functions in the central nervous system (CNS). Astrocytes comprise the major cell type in the brain. These immune active cells are capable of responding to proinflammatory cytokines and endotoxins, which stimulate transcriptional pathways leading to induction of genes, including the inducible nitric oxide synthase (iNOS) and secretory phospholipase A2 (sPLA2). In this study, we investigate the effects of ethanol on cytokine-induced iNOS and sPLA2 in immortalized astrocytes (DITNC). When DITNC cells were exposed to ethanol (0-200 mM) for 4 h prior to subsequent stimulation with cytokines for 16 h, NO production decreased with increasing ethanol concentrations starting from 50 mM. At ethanol concentrations higher than 100 mM, ethanol also inhibited cytokine-induced sPLA2 release into the culture medium. The inhibitory effect of ethanol on NO production corresponds well with the decrease in iNOS protein and NOS enzyme activity, but not with iNOS and sPLA2 mRNA nor binding of NF-kappaB to DNA. The inhibition of cytokine-induced NO production by ethanol was also dependent on the time of ethanol exposure to the cells, but addition of acetaldehyde up to 200 microM did not elicit any changes. Taken together, these results provide evidence for a posttranscriptional mode of ethanol action on the cytokine induction pathway for NO production in astrocytes.

Cigarette smoke decreases the expression of secretory component in human bronchial epithelial cells, in vitro

Epithelial secretory component (SC) is thought to be essential for immunologic protection of the respiratory tract from viral and bacterial infection, since it transports polymeric IgA from the basolateral to the luminal surface of epithelial cells. We have hypothesized that recurrent infection in airways of cigarette smokers is at least partly a consequence of cigarette smoke-induced downregulation of the expression and/or release of SC from airway epithelial cells, subsequently resulting in decreased transcytosis of secretory IgA to the airway lumen. To test this hypothesis, we have cultured human bronchial epithelial cells (HBEC) from surgical tissues and exposed these for 20 minutes to either air or cigarette smoke. Following exposure to cigarette smoke the HBEC cultures were incubated for a further period of up to 24 h, during which time separate cultures were processed by immunocytochemistry for the presence of SC, in a time-dependent manner. The stained HBEC cultures were evaluated by colour image analysis for the percentage of total cells staining for SC. Exposure to cigarette smoke significantly decreased the percentage of total HBEC staining for secretory component from a baseline value (median and interquartile[IQ]1, IQ3) of 35.9% (26.5, 41.6) to 15.7% (8.2, 25.4; p < 0.05) 1 h after exposure, compared with exposure to air. The percentage of cells staining for secretory component were further reduced to 5.3% (3.3, 6.4; p < 0.01), 6 h after exposure, compared to exposure to air. After incubation for 24 h following exposure to cigarette smoke, there was gross cell damage and the cells were not suitable for immunocytochemical analysis. These results suggest that short-term exposure to cigarette smoke may compromise the immune barrier function of the airway mucosa by decreasing the expression and/or release of epithelial SC, thereby decreasing the transcytosis of IgA necessary for inactivating the microbial pathogens in the airway lumen.

The serological and molecular epidemiology of GB virus C/hepatitis G virus infection in a hepatitis C and B endemic area

OBJECTIVES

To investigate the serological and molecular characteristics of GB virus C/hepatitis G virus (GBV-C/HGV) infection in the hepatitis C virus (HCV)/hepatitis B virus (HBV)-endemic areas in Taiwan.

METHODS

Sera from 200 residents from Masago, an HCV/HBV-endemic community in Taiwan, and 400 blood donors were tested for GBV-C/HGV RNA by using nested reverse transcription-polymerase chain reaction and for antibodies to GBV-C/HGV E2-protein (anti-E2) by an enzyme-linked immunosorbent assay. Phylogenetic analysis of GBV-C/HGV was performed.

RESULTS

The prevalence of GBV-C/HGV viraemia, anti-E2 and GBV-C/HGV exposure among residents of Masago was significantly higher than that among donors (17.0%, 25.5% and 39.5% vs. 3.3%, 7.5% and 10.3%, respectively; all P < 0.0001). In Masago, the prevalence of GBV-C/HGV exposure was significantly higher in residents exposed to HCV than in those without HCV exposure (45.8% vs. 24.1%;P< 0.005). Based on multivariate analyses, HCV viraemia was the only significant factor associated with elevated levels of alanine aminotransferase in Masago. Phylogenetic analysis showed all 34 GBV-C/HGV isolates from Masago clustered within genotype 3.

CONCLUSIONS

GBV-C/HGV was highly prevalent in Masago, an HCV/HBV-endemic community in Taiwan. HCV viraemia played the most important clinical hepatopathic role in the area. Infections with other hepatitis viruses did not influence the anti-E2 seroconversion from GBV-C/HGV infections.

Coronary artery bypass grafting on the beating heart using the octopus method--a case report

A 74-year-old male was admitted due to chest tightness for one month. He had received percutaneous transilluminal coronary angioplasty (PTCA) because of single-vessel disease one year ago. Cardiac catheterization examination carried out during this admission revealed 90% stenosis of the left anterior descending coronary artery (LAD) and circumflex branch (CX). Because another attempt of PTCA was considered not optimal, the patient was advised to undergo surgical grafting to which he consented. After expediently balancing the merits and demerits of every practicable surgical procedure--the essential determinant in selection of which was that the patient's condition and criteria of indication of that procedure were in perfect harmony--we decided to carry out minimally invasive direct coronary artery bypass (MIDCAB) with the application of Octopus tissue stabilizer. We report the surgical course and anesthetic management of the patient and discourse some detail in MIDCAB.