Establishment of a human hepatocyte line (OUMS-29) having CYP 1A1 and 1A2 activities from fetal liver tissue by transfection of SV40 LT

Immortalized human hepatocytes that can retain functions of drug-metabolizing enzymes would be useful for medical and pharmacological studies and for constructing an artificial liver. The aim of this study was to establish immortalized human hepatocyte lines having differentiated liver-specific functions. pSVneo deoxyribonucleic acid, which contains large and small T genes in the early region of simian virus 40, was introduced into hepatocytes that had been obtained from the liver of a 21-wk-old fetus. Neomycin-resistant immortalized colonies were cloned and expanded to mass cultures to examine hepatic functions. Cells were cultured in a chemically defined serum-free medium, ASF104, which contains no peptides other than recombinant human transferrin and insulin. As a result, an immortal human hepatocyte cell line (OUMS-29) having liver-specific functions was established from one of the 13 clones. Expression of CYP 1A1 and 1A2 messenger ribonucleic acid by the cells was induced by treatment with benz[a]pyrene, 3-methylcholanthrene, and benz[a]anthracene. OUMS-29 cells had both the polycyclic aromatic hydrocarbon receptor (AhR) and AhR nuclear translocator. Consequently 7-ethoxyresorufin deethylase activity of the cells was induced time- and dose-dependently by these polycyclic aromatic hydrocarbons. This cell line is expected to be instrumental as an alternative method in animal experiments for studying hepatocarcinogenesis, drug metabolisms of liver cells, and hepatic toxicology.

[Effect of pentoxifylline on promoter activity of human alpha 1(I) procollagen gene]

OBJECTIVE

To study the effect of pentoxifylline (PTX) on promoter activity of human alpha 1(I) procollagen (COL1A1) gene and the influence of PTX on the promoter activity induced by insulin-like growth factor 1 and insulin.

METHODS

The constructs of pCOLH2.5 containing -2483 approximately +42bp of the procollagen gene and chloramphenicol acetyltransferase (CAT) as reporter gene were transiently transfected into human skin fibroblasts. The cells were subsequently treated with PTX or IGF-1 or insulin, or PTX plus IGF-1 or insulin. The CAT activity was assessed 24h after PTX and the cytokines added.

RESULTS

PTX of 0.4 mmol/L, 2 mmol/L, and 10 mmol/L decreased the CAT activity of pCOLH 2.5 to 82%+/-9%, 58%+/-8%, and 32%+/-13% of the control level, respectively. IGF-1 and insulin increased the activity of the construct. PTX could inhibit the CAT activity of pCOLH2.5 induced by IGF-1 and insulin.

CONCLUSIONS

These studies indicate that PTX downregulates the promoter activity of the human COL1A1 gene, while IGF-1 and insulin upregulates it. PTX can inhibit the promoter activity induced by IGF-1 and insulin.

Overexpression of platelet-derived growth factor B and downregulation of PDGF-receptor alpha in human immortalized fibroblasts

Since immortalization of cells is critical in multistep carcinogenesis, efforts should be made to elucidate the mechanisms of the immortalization. To determine whether platelet-derived growth factor (PDGF) signal pathways play a role in immortalization of cells, we compared mRNA expressions of PDGFs and their receptors in three immortalized human fibroblast cell lines (SUSM-1, OUMS-24F, and KMST-6) with their normal parent cells. As a result, mRNA expression of PDGF-B (oncogene: c-sis) was upregulated in these immortalized cells. Unexpectedly, the expression of alpha- and beta-PDGF receptor genes was downregulated. PDGFR-alpha mRNA was remarkably decreased. When exogenous PDGFR-alpha was expressed transiently in the KMST-6 cells, the morphology of the cells resembled that of normal cells. These results suggest that the overexpression of PDGF-B (c-sis) and downregulation of PDGFR-alpha are related to the phenotypic characteristics of immortalized human cells.

Sialogogic activity in the rat of peptides analogous to [Tyr8]-substance P in which substitutions have been made in the N-terminal amino acids

In order to elucidate the regulatory roles for salivation of amino acids in positions 1-4 of the N-terminal region of [Tyr8]-substance P (SP), the structure-sialogogic activity correlations of various synthetic octa- to undecapeptides replaced in positions 1-4 of [Tyr8]-SP with each of 19 common amino acids, one by one, and with the same sequence of the C-terminal hepatapeptide as that of [Tyr8]-SP, were studied in the submandibular glands of rats after intraperitoneal injection. Each of 19 octa-, nona-, deca- and undecapeptides with replaced amino acids and a penta- to decapeptide with the progressive elimination of the N-terminal portion were newly synthesized by the multipin peptide method. All octa- to undecapeptides replaced with each of 19 common amino acids in positions 1-4 had sialogogic activities. In 19 octa- and decapeptides in which P4 and P2 had been replaced, four and three replacements, respectively, had significantly increased secretory activities. In contrast, in 19 nonapeptides in which K3 had been replaced, none had significantly increased secretory activities. Furthermore, in 19 undecapeptides in which R1 had been replaced, most replacements had significantly increased or equipotent activities for fluid secretion. It is concluded that amino acids in the N-terminal region of various tachykinins may not need to be strictly conserved and that amino acid residues in the N-terminal portion, R1 in particular and P2, may strongly inhibit secretory activity.

Lipopolysaccharide potentiates the effect of hepatocyte growth factor upon replication in lung, thyroid, spleen, and colon in rats in vivo

Induction of replication may potentiate in vivo gene therapy, as some viral vectors only transduce dividing cells. Hepatocyte growth factor (HGF) increases the percentage of replicating hepatocytes to 18-fold that in normal rats, and lipopolysaccharide (LPS) modestly potentiates this effect. In this study, the effect of iv HGF upon replication in other organs was determined. HGF at 10 mg/kg resulted in replication that was < or =3-fold that of normal rats in alveolar and proximal renal tubular cells. HGF alone had no effect upon replication of epithelial cells from the bronchi, thyroid, pancreas, or colon or upon cells from the muscle, pancreatic islets, spleen, blood vessels, or thymus. HGF and LPS at 5 mg/kg resulted in replication that was 9-fold that of normal rats in alveolar cells, 25-fold in bronchial epithelial cells, 4-fold in thyroid epithelial cells, 1.5-fold in the red pulp of the spleen, and 2-fold in colonic epithelial cells. The synergistic effect may be due to the fact that LPS upregulated the HGF receptor c-met in thyroid, spleen, and colon. We conclude that iv administration of HGF alone is relatively specific for inducing hepatocyte replication and would allow selective gene transfer into the liver.

CMV-beta-actin promoter directs higher expression from an adeno-associated viral vector in the liver than the cytomegalovirus or elongation factor 1 alpha promoter and results in therapeutic levels of human factor X in mice

Although AAV vectors show promise for hepatic gene therapy, the optimal transcriptional regulatory elements have not yet been identified. In this study, we show that an AAV vector with the CMV enhancer/chicken beta-actin promoter results in 9.5-fold higher expression after portal vein injection than an AAV vector with the EF1 alpha promoter, and 137-fold higher expression than an AAV vector with the CMV promoter/enhancer. Although induction of the acute-phase response with the administration of lipopolysaccharide (LPS) activated the CMV promoter/enhancer from the context of an adenoviral vector in a previous study, LPS resulted in only a modest induction of this promoter from an AAV vector in vivo. An AAV vector with the CMV-beta-actin promoter upstream of the coagulation protein human factor X (hFX) was injected intravenously into neonatal mice. This resulted in expression of hFX at 548 ng/ml (6.8% of normal) for up to 1.2 years, and 0.6 copies of AAV vector per diploid genome in the liver at the time of sacrifice. Neonatal intramuscular injection resulted in expression of hFX at 248 ng/ml (3.1% of normal), which derived from both liver and muscle. We conclude that neonatal gene therapy with an AAV vector with the CMV-beta-actin promoter might correct hemophilia due to hFX deficiency.

Cdk5 mediates changes in morphology and promotes apoptosis of astrocytoma cells in response to heat shock

The cyclin-dependent kinase member, Cdk5, is expressed in a variety of cell types, but neuron-specific expression of its activator, p35, is thought to limit its activity to neurons. Here we demonstrate that both Cdk5 and p35 are expressed in the human astrocytoma cell line, U373. Cdk5 and p35 are present in the detergent-insoluble cytoskeletal fraction of this cell line and Cdk5 localizes to filopodia and vinculin-rich regions of cell-matrix contact in lamellopodia. When exposed to a 46(o)C heat shock, U373 cells change shape, lose cell-matrix contacts and show increased levels of apoptosis. To test whether Cdk5 activation might play a role in these events, U373 cells were stably transfected with histidine-tagged or green fluorescent protein-tagged constructs of Cdk5 or a dominant negative mutation, Cdk5T33. Under normal growth conditions, growth characteristics of the stably transfected lines were indistinguishable from untransfected U373 cells and Cdk5 localization was not changed. However, when subjected to heat shock, cells stably transfected with Cdk5-T33 remained flattened, showed little loss of cell-matrix adhesion, and exhibited significantly lower levels of apoptosis. In contrast, cells that overexpressed wild-type Cdk5 showed morphological changes similar to those seen in untransfected U373 cells in response to heat shock and had significantly higher levels of apoptosis. Heat-shocked cells showed changes in p35 mobility and stability of the Cdk5/p35 complex consistent with endogenous Cdk5 activity. Together these findings suggest that endogenous Cdk5 activity may play a key role in regulating morphology, attachment, and apoptosis in U373 cells, and raise the possibility that Cdk5 may be a general regulator of cytoskeletal organization and cell adhesion in both neuronal and non-neuronal cells.

Primary culture and characterization of enamel organ epithelial cells

The cells of the enamel organ are programmed by signals such as growth factors and extracellular matrix components to differentiate and form dental enamel. To study how the enamel organ epithelial cells control enamel development, we have begun to characterize a primary porcine enamel organ epithelial cell culture system. The unerupted molars of 3 month old pigs were isolated, the cells were digested into a single cell suspension and grown in media either with or without serum. Expression of amelogenin and ameloblastin mRNA was monitored by RT PCR, and protein secretion was identified by immunohistochemistry. Cells grown in MEM formed a mixed cell population of epithelial- and fibroblast-like cells which grew past confluence, formed nodules, mineralized, and expressed low levels of amelogenin and ameloblastin protein. In LHC-9 media, which is selective for epithelial cells, the cells did not grow past confluence but secreted amelogenin and ameloblastin proteins more strongly. Cell viability was maintained in both serum-free and serum-containing media. However, in the serum-free media, cell proliferation proceeded slowly. Although cells grown in MEM mineralized, the mixed cell population may make studies of specific ameloblast-like cells more difficult. However, cells grown in a culture media selective for epithelial cells will require modifications such as cell immortalization to allow long term studies of cell regulation and interaction. In summary, we have established an enamel organ epithelial cell culture system which will enable us to study the role of ameloblasts in enamel matrix formation, ameloblast regulation, as well as cell-matrix interactions. Selection of specific culture conditions will depend on the questions being addressed in individual studies.

Surface photo-grafting of polyurethane with 2-hydroxyethyl acrylate for promotion of human endothelial cell adhesion and growth

Cytocompatible polyurethane (PU) surface was prepared by photo-grafting 2-hydroxyethyl acrylate (HEA) onto the membrane surface. Graft polymerization was conducted by combining the use of the photo-oxidation and irradiation grafting. PU membrane was photo-oxidized to introduce the hydroperoxide groups onto the surface, then the membrane, immersed previously in monomer solution, was irradiated under UV light. The ATR-FTIR spectra, element spectroscopy for chemical analysis (ESCA), scanning electron microscopy (SEM) and water contact angle characterized the grafted copolymers and verified the occurrence of graft polymerization. The results showed that UV irradiation could realize the graft polymerization effectively and the grafting was confined within the surface layer. The grafted membrane showed minimal surface morphology. Human umbilical vein endothelial (HUVE) cells were seeded on the grafted surface. The performance of the surface in cell attachment and growth correlated with the oxygen content and mainly the carbonyl content on the surface. Cells were spread more extensively and grew faster on the surface with a higher oxygen content.

[Modulation of the activity of human alpha1 (I) procollagen gene promoter by basic fibroblast growth factor (bFGF)]

OBJECTIVE

To investigate the modulating effect of bFGF on the proliferation of human cutaneous fibroblasts and on the activity of human alpha1 (I) procollagen gene promoter.

METHODS

Human cutaneous fibroblasts were cultured and subcultured by tissue block culture technique. The influence of different concentrations of bFGF on the proliferation of fibroblasts was determined by ELISA method with BrdU incorporated into fibroblast DNA. Three plasmids containing various lengths of 5prime prime or minute flank sequences of human alpha1 (I) procollagen gene and CAT as reporter gene were constructed and transfected into the fibroblasts by FuGENE transfection reagent. The quantitative expression of the fibroblast CAT was determined by ELISA after treatment with bFGF.

RESULTS

After 24 hours of treatment of the fibroblasts by serial concentrations (0.25 ng/ml similar 64.00 ng/ml) of bFGF in DMEM containing 2% (v/v) or 10% (v/v) FCS, the BrdU incorporation into DNA was determined. The proliferating rate of the fibroblasts differed significantly from each other in all the groups (P < 0.05). After the fibroblasts were transfected with the three plasmids and treated thereafter by 4 ng/ml and 16 ng/ml of bFGF for 24 hours, the relative CAT expression values were determined. It indicated that the expression value was evidently different between bFGF processing and control groups (P < 0.05).

CONCLUSION

bFGF might inhibit the proliferation of human cutaneous fibroblasts and exert negative regulating effect on the human alpha1 (I) procollagen gene promoter sequence in dose -- dependent pattern.

Enhanced expression of cyclin E and cyclin A in human hepatocellular carcinomas

BACKGROUND

Disruption of the G1/S check point leads to uncontrolled cell growth, resulting in the development of cancers.

MATERIALS AND METHODS

Cell cycle regulatory molecules were investigated in 33 surgically resected hepatocellular carcinoma (HCC) samples from 30 patients by Western blotting.

RESULTS

Enhanced expressions of cyclin E and cyclin A were detected at frequencies of 18/33 and 26/33 in HCCs, respectively, as compared with their neighboring noncancerous tissues. The enhanced expression of cyclin E, but not that of cyclin A, correlated with hyperphosphorylation of pRb and high frequency of Ki-67-positive cells. Thus, the HCCs with enhanced cyclin E expression probably contain a relatively large number of proliferating cancer cells.

CONCLUSIONS

The degree of cyclin E expression can be used as a prognostic parameter of HCC. In addition, cyclin E may become a molecular target in the treatment of HCCs.

[Study on the relations between HLA-DRB 1 alleles and Helicobacter pylori infection]

OBJECTIVE

In order to study the relation between human leukocyte antigen (HLA) DRB1 alleles and Helicobacter pylori (Hp) infection.

METHODS

Hp-IgG antibody from 46 gastric cancer (GC), 75 esophageal cancer and 100 population-based controls were identified by Hp-IgG quantitative enzyme immunoassay. Biotest HLA-DRB enzyme linked probe hybridization assay kit (low resolution) was used to identify DRB1 alleles.

RESULTS

(1) Frequency of DRB1 * 08 was significantly higher in Hp-IgG positive group than in Hp-IgG negative group (13.1% vs 4.4%, chi(2) = 11.14, P < 0.001). Frequency of DRB1 * 12 was significantly lower in Hp-IgG positive group than in Hp-IgG negatives (5.4% vs 11.3%, chi(2) = 4.49, P < 0.05). (2) Frequency of DRB1 * 02 in GC was significantly higher than that of controls. Frequency of DRB1 * 07 in GC was significantly lower than that of controls. However, neither the frequency of DRB1 * 02 between Hp-IgG positive and Hp-IgG negative groups nor the frequency of DRB1 * 07 between Hp-IgG positive and Hp-IgG negative groups showed significant differences in GC and controls.

CONCLUSIONS

(1) HLA-DRB1 * 08 might serve a genetic risk factor for Hp infection while DRB1 * 12 might play a role of protecting effect against Hp infection. (2) DRB1 * 02 might be a genetic risk factor for GC while DRB1 * 07 might play a role of protecting effect against GC. However, the relations between DRB1 * 02, DRB1 * 07 and GC were not associated with Hp infection.

[Population growth, distribution pattern and sampling technique of Thrips palmi on eggplant]

Population growth of Thrips palmi Karny on eggplant (Solanum melongena L.) were analyzed by mathematical models. The rate of population increase (r) of the adults and immature (instars 1-2) T. palmi were estimated to be 0.0630 and 0.0801 respectively in the open fields, and 0.0983 and 0.1036 respectively in the greenhouse. K value of logistic curve of T. palmi was estimated to be 33.90 in the greenhouse, and 23.50 in the open fields. The relationship between mean crowding (M*) and mean density (M) of T. palmi per eggplant leaf were estimated by Iwao's M*-M regression. The regression equation of adult and immature T. palmi on eggplant were: M* = 0.6011 + 1.468M and M* = 7.2515 + 2.064M respectively. The regression equation of the number of adult and immature was M* = 7.5138 + 1.9119M. When the population density of the adults and immature T. palmi per eggplant leaf were 10 to 100, the number of sampling should be 78 to 44.

p53-dependent induction of heat shock protein 27 (HSP27) expression

Transcriptional activation of the p53 target genes plays a critical role in the cellular response to DNA damage, hypoxia, cellular stress and other signals regulating the cell cycle and apoptosis. The discovery of new p53 target genes continues to reveal novel mechanisms of action of this multifaceted protein. We used cDNA arrays to search for p53-regulated genes in prostate cancer cells. In this report, we describe robust induction of heat shock protein 27 (hsp27) in prostate cancer cells (DU145, LNCaP, PC3) following wild-type p53 expression from an adenoviral p53 expression vector (AdWTp53). A mutant p53 (R175H)-containing adenoviral expression vector did not induce hsp27. hsp27 expression was not altered in prostate cancer cells following expression of cyclin-dependent kinase inhibitors: p21(waf1/cip1) and p27(kip1) from adenoviral expression vectors. Treatment of cells with staurosporine, an apoptosis-inducing agent, did no affect hsp27 expression. These observations provide evidence that induction of hsp27 expression was wild-type p53-specific and was not due to non-specific effects of cell growth arrest and/or apoptosis. Previous studies and the experiment reported here show induction of hsp27 expression in response to androgen ablation, a physiological state that induces apoptosis in prostatic epithelial cells. The nature of p53 and hsp27 interactions in the regulation of apoptosis and/or cell growth needs to be further defined.

[Ordination analysis on relationship between bryophyte distribution and climatic factors]

Based on the data of climate and bryoflora in 21 mountainous regions of China, 61 moss families, 23 genera of Dicranaceae, 17 species of genus Campylopus and 35 species of genus Dicranum were analyzed by Canonical Correspond Analysis(CCA) and Detrended Canonical Correspond Analysis (DDCA) to reveal their distribution relationships with nine climatic factors, including annual average temperature, January average temperature, July average temperature, annual average rainfall, annual average fog days, annual average frost days and annual average light hours. The similarity of geographical elements among nine mountains in China and their relationships with climatic factors were also analyzed. The methods of applying DDCA and CCA to analyze the relationships between bryophyte and climatic factors were thus introduced. The studies indicate that CCA and DCCA are applicable in florology and phytogeography.

[The effect of Shenmai injection on the expression of TNFalpha mRNA of the macrophages in scalded mice]

OBJECTIVE

To explore the effect of Shenmai injection on the expression of TNFalpha mRNA of peritoneal macrophages in scalded mice.

METHODS

BALB/c mice inflicted with 11% TBSA III degree scalding injury were employed as the model. Shenmai injection was composed of 100 mg of red ginseng and 100 mg of lily turf root in 1 ml injection solution and was administered to mice via peritoneal injection in a dose of 2.5 ml per kilogram of mice body weight per day for 5 days. The expression of TNFalpha mRNA was determined by semi-quantitative RT-PCR.

RESULTS

The expression of macrophage TNFalpha mRNA was significantly increased in the scalded mice, while the expression was obviously lowered after the administration of Shenmai injection (P < 0.01) to scalded mice and the survival rate of the scalded mice was thus markedly increased (P < 0.05).

CONCLUSION

The beneficial effect of Shenmai injection on the scalded mice might be related to its inhibitory effect on the hyperexpression of macrophage TNFalpha mRNA. Shenmai injection could lower down the expression of TNFalpha in scalded mice and raise the survival rate of scalded mice.

Biomechanical and morphological properties in rat large intestine

Intestinal stress-strain distributions are important determinants of intestinal function and are determined by the mechanical properties of the intestinal wall, the physiological loading conditions and the zero-stress state of the intestine. In this study the distribution of morphometric measures, residual circumferential strains and stress-strain relationships along the rat large intestine were determined in vitro. Segments from four parts of the large intestine were excised, closed at both ends, and inflated with pressures up to 2kPa. The outer diameter and length were measured. The zero-stress state was obtained by cutting rings of large intestine radially. The geometric configuration at the zero-stress state is of fundamental importance because it is the basic state with respect to which the physical stresses and strains are defined. The outer and inner circumferences, wall thickness and opening angle were measured from digitised images. Subsequently, residual strain and stress-strain distributions were calculated. The wall thickness and wall thickness-to-circumference ratio increased in the distal direction. The opening angle varied between approximately 40 and approximately 125 degrees with the highest values in the beginning of proximal colon (F=1.739, P<0.05). The residual strain at the inner surface was negative indicating that the mucosa-submucosal layers of the large intestine in no-load state are in compression. The four segments showed stress-strain distributions that were exponential. All segments were stiffer in longitudinal direction than in the circumferential direction (P<0.05). The transverse colon seemed stiffest both in the circumferential and longitudinal directions. In conclusion, significant variations were found in morphometric and biomechanical properties along the large intestine. The circumferential residual strains and passive elastic properties must be taken into account in studies of physiological problems in which the stress and strain are important, e.g. large intestinal bolus transport function.

Delivery of a retroviral vector expressing human beta-glucuronidase to the liver and spleen decreases lysosomal storage in mucopolysaccharidosis VII mice

Mucopolysaccharidosis VII (MPS VII) is caused by beta-glucuronidase (beta-gluc) deficiency and results in lysosomal storage due to the inability to degrade glycosaminoglycans. Transfer of a beta-gluc gene into the liver reduces hepatic pathology as well as storage in other organs via uptake of secreted protein. A Moloney murine leukemia-based retroviral vector expressing the human beta-gluc cDNA was injected intravascularly into MPS VII mice during hepatocyte replication, which was induced with im injection of an adenoviral vector that transiently expressed hepatocyte growth factor (Ad.CMV. HGF). This procedure resulted in transduction of approximately 1% of hepatocytes, 1% of normal liver enzyme activity, and a reduction in lysosomal storage in the liver at 3.5 months. Surprisingly, controls that received retroviral vector without HGF had transduction of nonparenchymal cells in the liver, significant levels of enzyme and RNA in the liver at 2 but not 3.5 months, and reduced lysosomal storage at 3.5 months. Transduction was also achieved in the replicating cells of the spleen, where lysosomal storage was reduced. An approach using a retroviral vector without a growth factor might temporarily reduce lysosomal storage in the liver and spleen in humans. Addition of HGF might be used to augment and prolong gene transfer.

Engineering of head-mounted projective displays

Head-mounted projective displays (HMPD's) are a novel type of head-mounted display. A HMPD consists of a miniature projection lens mounted upon the user's head and retroreflective sheeting material placed strategically in the environment. First, the imaging concept of a HMPD is reviewed and its potential advantages and disadvantages are discussed. The design and a bench prototype implementation are then presented. Finally, the effects of retroreflective materials on the imaging properties and the optical properties of HMPD's are comprehensively investigated.

Basic and clinical study on the antithrombotic mechanism of glycosaminoglycan extracted from sea cucumber

OBJECTIVE

To investigate the antithrombotic mechanism of glycosaminoglycan (GAG) extracted from sea cucumber.

METHODS

We studied the effects of GAG on the coagulant pathway by measuring cloting time. The antithrombin mechanism of GAG was checked by assaying its effects on the thrombin activity in normal human pooled plasma, purified human heparin cofactor II system and antithrombin III system. The effects of GAG on the assembly, dispersion, and structure of fibrin gels as well as on the activity of plasmin were studied by means of turbidimetry, electron microscopy, and chromogenic substrate assay. We studied the effect of GAG on the expression and transcription of tissue factor (TF) and thrombomodulin (TM) in LPS (lipopolysaccharide)-stimulated human umbilical vein endothelial cells (HUVECs), and used heparin as a control. HUVECs were treated with different concentrations of GAG (1 microgram/ml, 5 micrograms/ml, and 10 micrograms/ml respectively) and 5 micrograms/ml heparin as a control together with LPS (1 microgram/ml). After incubation for 6 hours, TF and TM were investigated by ELISA and the mRNA study was carried out by RT-PCR. In a clinical trail, a series of variables were observed before and after treatment with GAG in patients recovering from cerebral ischemic stroke or suffering from ischemic heart disease.

RESULTS

The TT and APTT were significantly prolonged by GAG (0.1 microgram/ml). GAG inhibited thrombin activity in the presence of HCII with a second order rate constant of 1.14 x 10(7) m-1.min-1, which was 4.6 times higher than that of ATIII. GAG significantly inhibited the polymerization of fibrin monomer and enhanced the activity of plasmin in a concentration dependent manner. GAG could impair TF mRNA expression and up-regulate TM mRNA expression. The result of clinical trail showed that the fat metabolism was enhanced in addition to the anticoagulant and the blood viscosity reducing effects. No side-effect was found.

CONCLUSIONS

GAG mainly affected on the intrinsic pathway of blood coagulation. GAG was similar to dermatan sulfate both in the efficiency and in the mechanism of antithrombin. The acceleration of colt lysis by GAG depended on its ability to increase the activity of plasmin, to inhibit the polymerizing of fibrin monomer, and consequently, to alter the architecture of the fibrin net work. This effect on HUVECs appears to be at a transcriptional level and might be relevant for the antithrombotic action of GAG. GAG possess anticoagulant activity in vivo and it is a promising drug for antithrombotic therapy.

Histomorphometry and strain distribution in pig duodenum with reference to zero-stress state

The morphometry at no-load and zero-stress states and residual circumferential strains were determined along the pig duodenum in vitro in seven pigs. The no-load state was obtained by cutting eleven 2-mm-wide rings at 10% intervals along the duodenum. The zero-stress state was obtained by cutting the rings radially. The zero-stress state provides a standard morphological state to describe tissue since internal and external forces do not affect the tissue. The morphometric measures were obtained from digitized images, and the layer thicknesses were measured from histological sections. The mucosal and serosal circumferences, the wall thickness, and the wall thickness-to-mucosal radius ratio were largest in the proximal end of the duodenum (f > 1.9, P < 0.05). The thickness of the submucosal stratum compactum layer and the opening angle increased in distal direction (f = 2.3, P < 0.05 and = 6.5, P < 0.001). The residual strain at the mucosal surface was negative, indicating that the mucosa-submucosa layers of duodenum in no-load state are in compression. Distension experiments showed that the residual strain makes the stress distribution through the wall more uniform in the pressurized state. In conclusion, the large circumferential residual strains must be taken into account in the study of physiological problems, in which the stresses and strains are important, eg, the bolus transport function.

[Identification and functional analysis of NIFA from Mesorhizobium huakuii 159]

The nifA gene from Mesorhizobium huakuii 159 was identified and sequenced. An open reading frame coding for 44734D. NifA protein would detected. Comparison of the deduced amino acid sequence with other NifA proteins revealed the presence of the conserved central domain and the C-terminal DNA-binding domains. But the predicted M. huakuii NifA protein lacked a N-terminal domain that is present in the homologous proteins. Mutants with Nif- phenotype were obtained by site-directed Tn5 mutagenesis. A nifA constitutively expressed plasmid was constructed, and this plasmid could activate the nifH expression in YMC11.