Antitumor effects of Scutellariae radix and its components baicalein, baicalin, and wogonin on bladder cancer cell lines

OBJECTIVES

To investigate the antitumor effects of Scutellariae radix and its components baicalein, baicalin, and wogonin on human bladder cancer cell lines (KU-1 and EJ-1) and a murine bladder cancer cell line (MBT-2).

METHODS

Bladder cancer cells were incubated with various concentrations of the agents. Antiproliferative activity against the bladder cancer cell lines was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diplenyl tetrazolium bromide assay. In an in vivo experiment, the mice were subcutaneously injected with MBT-2 cells, and Scutellariae radix was orally administered at a dose of 2 or 10 mg per mouse one time daily for 10 days from day 11 to day 20.

RESULTS

All the drugs inhibited cell proliferation in a dose-dependent manner, but baicalin exhibited the greatest antiproliferative activity. The concentration of baicalin necessary to obtain 50% inhibition was 3.4 microg/mL for KU-1, 4.4 microg/mL for EJ-1, and 0.93 microg/mL for MBT-2. For KU-1 and MBT-2, the percentage of cell survival significantly decreased (P <0.05) at a baicalin concentration of 1 microg/mL. In an in vivo experiment, antitumor effects of Scutellariae radix on C3H/HeN mice implanted with MBT-2 were investigated. All the control mice showed a progressive increase in tumor volume, reaching 2.81 +/- 0.18 cm(3) on day 20 and 5.36 +/- 0.44 cm(3) on day 25. However, when Scutellariae radix was orally administered at a dose of 10 mg per mouse one time daily for 10 days from day 11 to day 20, the tumor volume was 1.99 +/- 0.19 cm(3) on day 20 and 3.86 +/- 0.26 cm(3) on day 25, a significant inhibition of tumor growth (P <0.05). Conclusions. These results suggest that Chinese herbal medicines may become an attractive and promising treatment for bladder cancer.

An enantioconvergent route to (-)-shikimic acid via a palladium-mediated elimination reaction

[reaction--see text] (-)-Shikimic acid, the key intermediate in the shikimate pathway in plants and microorganisms, has been synthesized in an enantioconvergent manner from both enantiomeric starting materials by employing a palladium-mediated elimination reaction as the key step.

A new method for qualitative and quantitative evaluation of tooth displacement under the application of orthodontic forces using magnetic sensors

The purpose of this study was to develop a new method for the quantitative and qualitative measurement of tooth displacement under load and to clarify the relationship between the force system acting on a tooth and a resultant movement. A combination of eight magnetic sensors and a magnet was employed to measure three-dimensional displacement. Two sets of sensors and a magnet were placed in front and at the back of a front tooth subjected to orthodontic forces. Magnets and sensors were fixed to the subject tooth and posterior teeth, respectively. Sensors detected displacements of two magnets extended from the subject tooth separately in real time. The tooth trajectories projected on the sagittal plane were studied. From displacements of two magnets, angle of tooth rotation, the position of center of rotation and the amount and direction of displacement of an arbitrary point on the tooth could be calculated with high accuracy. Also, the location of center of resistance could be determined. It was found that the center of rotation is moving substantially even with a small difference in the level of force application. Furthermore, a small amount of displacement of the center of resistance was observed with varying the force magnitude.

Forced expression of terminal deoxynucleotidyl transferase in fetal thymus resulted in a decrease in gammadelta T cells and random dissemination of Vgamma3Vdelta1 T cells in skin of newborn but not adult mice

The repertoire of lymphocyte receptor genes encoded in a germline is further diversified by a number of processes, including the template-independent addition of nucleotides (N regions) by means of terminal deoxynucleotidyl transferase (TdT). Normally, mouse gammadelta T cells in the early fetal thymus, whose T-cell receptor (TCR) genes lack N regions and are encoded by Vgamma3-Jgamma1 and Vdelta1-Ddelta2-Jdelta2 with canonical junctions (invariant Vgamma3Vdelta1), are thought to be the precursors of dendritic epidermal T cells (DETC). We generated mutant mice whose endogenous TdT promoter was replaced with the lck promoter through homologous recombination. These mutant mice expressed TdT in fetal thymus, had abundant N regions and infrequent canonical junctions in gamma and delta rearrangements, and showed a decreased number of gammadelta T cells. Various Vgamma3Vdelta1 T cells, most of which had N regions in their TCR genes, were found to disseminate in the skin of newborn mutant mice, whereas normal numbers of DETCs with the invariant Vgamma3Vdelta1 rearrangement were observed in adult mutants. These data demonstrate that the regulation of TdT expression during fetal development is important for the generation of gammadelta T cells, and that Vgamma3Vdelta1 T cells, which have various junctional sequences in their TCR genes, randomly disseminate in skin, but invariant Vgamma3Vdelta1 T cells have a great advantage for proliferation in skin.

[Sarcoidosis with primary acute cavitation exacerbated by bronchial asthma]

A 22-year-old woman complaining of blurred vision visited our hospital in March 1995 and was given a diagnosis of uveitis. Chest X-ray and computed tomographic (CT) films demonstrated bilateral hilar lymphadenopathy (BHL), diffuse granular shadows in both lung fields, and a cavity with a thin, smooth wall in the right upper lung field. Because histopathologic findings from transbronchial lung biopsy specimens of the lung and cavity tissues disclosed sarcoid granuloma, the diagnosis was sarcoidosis with primary cavitation, which is very rare for this disease. Although BHL disappeared without medication, in November the patient experienced dyspnea due to attacks of bronchial asthma that had been in remission for a long period. Treatment with inhalation of becromethazone propionate markedly alleviated her symptoms. In May 1998, follow-up chest CT films demonstrated that the cavity had disappeared. This case suggested that sarcoidosis leads to a deterioration of asthma control, a conclusion supported by previous reports.

Protective role of intracellular glutathione against nitric oxide-induced necrosis in rat gastric mucosal cells

BACKGROUND

Nitric oxide synthase activity is increased in the stomach in association with Helicobacter pylori infection and portal hypertension, but the mechanism by which nitric oxide contributes to mucosal damage remains unclear.

AIM

To examine whether nitric oxide injures gastric mucosal cells and whether cellular glutathione affects nitric oxide-induced cytotoxicity.

METHODS

A confluent monolayer of RGM-1 gastric mucosal cells was exposed to nitric oxide donors (NOC5 or NOC12). Cell viability was determined by trypan blue dye exclusion, lactate dehydrogenase release and supravital staining with Hoechst 33342 and propidium iodide. The kinetics of the reduced/oxidized forms of glutathione were also measured, as well as the effect of glutathione-depletion or glutathione-precursor treatment on nitric oxide-induced cytotoxicity.

RESULTS

Excess exogenous nitric oxide produced by NOC5 or NOC12 induced necrosis in RGM-1 cells in a time- and concentration-dependent manner. The level of reduced glutathione drastically decreased prior to the loss of cell viability and remained low, but oxidized glutathione was not affected. Glutathione depletion increased necrosis of both NOCs in an NOC-concentration-related fashion, while pre-treatment with gamma-glutamylcysteine ethyl ester reduced their necrotic susceptibility.

CONCLUSION

Exogenous nitric oxide induced necrosis in gastric mucosal cells, and intracellular reduced glutathione protects gastric mucosal cells from damage by nitric oxide.

Lipoprotein(a) is a risk factor for occurrence of acute myocardial infarction in patients with coronary vasospasm

OBJECTIVES

The purpose of this study is to determine whether lipoprotein(a) (Lp[a]) is an independent risk factor for coronary spasm and occurrence of acute myocardial infarction (AMI) in patients with coronary spasm.

BACKGROUND

Although elevated serum Lp(a) levels are known to be associated with coronary atherosclerosis and AMI, the association between the elevated level of this lipoprotein and coronary spasm remains to be elucidated.

METHODS

Serum Lp(a) levels were measured using a latex immunoassay in 77 patients with coronary spasm but without a significant (>75%) fixed coronary stenosis, including 16 with prior myocardial infarction (MI), in 177 patients with a fixed stenosis but without rest angina, including 114 with prior MI and in 81 control subjects without coronary artery disease.

RESULTS

The serum Lp(a) level in patients with coronary spasm (median; 17 mg/dl) was higher (p < 0.01) than in control subjects (12 mg/dl) but lower (p < 0.01) than in patients with a fixed stenosis (23 mg/dl). The incidence of subjects with higher (>25 mg/dl) serum Lp(a) levels was higher in patients with a fixed stenosis (46%, p < 0.01) but not in patients with coronary spasm (27%), compared with control subjects (21%). Among the patients with coronary spasm, the incidence of higher Lp(a) levels was higher in patients with than in those without a history of prior MI (56% vs. 21%, p < 0.05). The patients with higher Lp(a) levels had a higher incidence of prior MI than those without (41% vs. 13%, p < 0.05). The multivariate analysis confirmed that higher serum Lp(a) level is an independent determinant for prior MI in these patients (odds ratio, 4.19; 95%, confidence interval, 1.03 to 17.00).

CONCLUSIONS

Elevated serum level of Lp(a) was found to be associated with a history of prior MI in patients with coronary spasm, suggesting that Lp(a) may play an important role in the genesis of thrombotic coronary occlusion and the occurrence of AMI subsequent to coronary spasm.

Acute Trypanosoma cruzi infection is associated with anemia, thrombocytopenia, leukopenia, and bone marrow hypoplasia: reversal by nifurtimox treatment

In the present work we show that acute infection of C3H mice with the CL strain of Trypanosoma cruzi is characterized by an exponential growth of parasites and high mortality accompanied by anemia, thrombocytopenia, leukopenia, and bone marrow hypoplasia. Administration of nifurtimox, a trypanocydal drug currently in clinical use at different days postinfection, modulates parasitemia and prevents mortality. More importantly, none of blood and bone marrow alterations were observed in nifurtimox-treated animals when treatment was initiated early in infection, one or seven days postinoculation. The bone marrow alterations were characterized by a decrease in the total number cells as well in the number of megakaryoblasts and erythroblasts. Transfer experiments of bone marrow cells from infected mice to noninfected lethally irradiated recipients revealed a poor marrow-repopulating activity. The colony forming units-spleen assay confirmed the depression of committed clonal progenitors cells and revealed a decreased number of granulocyte/macrophage, megacariocyte and erythrocyte colonies. In summary, this is the first report showing that acute T. cruzi infection results in profound alterations of the hematopoietic system and that these alterations can be prevented by nifurtimox treatment.

Different effects of IGF-I on insulin-stimulated glucose uptake in adipose tissue and skeletal muscle

The effect of insulin-like growth factor I (IGF-I) on insulin-stimulated glucose uptake was studied in adipose and muscle tissues of hypophysectomized female rats. IGF-I was given as a subcutaneous infusion via osmotic minipumps for 6 or 20 days. All hypophysectomized rats received L-thyroxine and cortisol replacement therapy. IGF-I treatment increased body weight gain but had no effect on serum glucose or free fatty acid levels. Serum insulin and C-peptide concentrations decreased. Basal and insulin-stimulated glucose incorporation into lipids was reduced in adipose tissue segments and isolated adipocytes from the IGF-I-treated rats. In contrast, insulin treatment of hypophysectomized rats for 7 days increased basal and insulin-stimulated glucose incorporation into lipids in isolated adipocytes. Pretreatment of isolated adipocytes in vitro with IGF-I increased basal and insulin-stimulated glucose incorporation into lipids. These results indicate that the effect of IGF-I on lipogenesis in adipose tissue is not direct but via decreased serum insulin levels, which reduce the capacity of adipocytes to metabolize glucose. Isoproterenol-stimulated lipolysis, but not basal lipolysis, was enhanced in adipocytes from IGF-I-treated animals. In the soleus muscle, the glycogen content and insulin-stimulated glucose incorporation into glycogen were increased in IGF-I-treated rats. In summary, IGF-I has opposite effects on glucose uptake in adipose tissue and skeletal muscle, findings which at least partly explain previous reports of reduced body fat mass, increased body cell mass, and increased insulin responsiveness after IGF-I treatment.

A new mechanism for anti-inflammatory actions of proton pump inhibitors--inhibitory effects on neutrophil-endothelial cell interactions

BACKGROUND

Neutrophil-endothelial cell interactions mediated by adhesion molecules may be involved in gastric mucosal inflammation associated with Helicobacter pylori or nonsteroidal anti-inflammatory drugs.

AIM

To investigate the effects of proton pump inhibitors and histamine-2 receptor antagonists (HRA) on neutrophil-endothelial cell adhesive interactions induced by H. pylori water extract (HPE) or interleukin-1beta (IL-1beta).

METHODS

Human peripheral neutrophils and umbilical vein endothelial cells were incubated with either proton pump inhibitors (lansoprazole and omeprazole) or HRA (famotidine and ranitidine). Neutrophil surface expression of CD11b and CD18 and endothelial cell intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) were assessed by flow cytometry and an enzyme immunoassay, respectively. Neutrophil adherence was defined as the ratio of exogenous neutrophils that adhered to the endothelial monolayers.

RESULTS

The expression of CD11b and CD18 on neutrophils and neutrophil-dependent adhesion to endothelial cells elicited by HPE were inhibited by lansoprazole and omeprazole at clinical relevant doses, and the expression of ICAM-1 and VCAM-1 on endothelial cells and endothelial-dependent neutrophil adherence induced by IL-1beta were also inhibited by lansoprazole and omeprazole at similar doses. Famotidine and ranitidine had no effect on neutrophil-endothelial cell interactions.

CONCLUSIONS

These results indicate that proton pump inhibitors can attenuate neutrophil adherence to endothelial cells via inhibiting the expression of adhesion molecules, suggesting that proton pump inhibitors may have anti-inflammatory activity.

Hybridization and breeding of the benomyl resistant mutant, Trichoderma harziantum antagonized to phytopathogenic fungi by protoplast fusion

A diploid strain obtained from heterokaryons of Trichoderma harzianum by protoplast fusion grew on minimal medium containing 100ppm benomyl. This strain inhibited the growth of the phytopathogenic fungus Fusarium oxysporum f. sp. raphani on paired cultures and also protected against radish yellows and a drop in germination induced by F. oxysporum f. sp. raphani.

Heterogeneous cardiac sympathetic innervation in heart failure after myocardial infarction of rats

We examined cardiac neuronal function and beta-receptor with a dual-tracer method of [(131)I]meta-iodobenzylguanidine (MIBG) and [(125)I]iodocyanopindolol (ICYP) in rat heart failure after myocardial infarction (MI). In rats with MI, left ventricular (LV) systolic function decreased, and LV dimension and right ventricular (RV) mass increased gradually. MIBG accumulations of the noninfarcted LV (remote region) and RV decreased by 15% at 1 wk compared with sham-operated rats, and these accumulations were restored by 71% and 56%, respectively, at 24 wk compared with age-matched sham rats despite sustained depletion of myocardial norepinephrine contents in these regions. ICYP accumulation of the remote region and of the RV did not decrease at any stages. Myocardial MIBG distribution was heterogeneous at 1 wk when it was lower in the peri-infarcted region than in the remote region, associated with reduced ICYP accumulation in the peri-infarcted region. The heterogeneous distribution of both isotopes disappeared at 12 wk. Thus cardiac sympathetic neuronal alteration was coupled with downregulation of beta-receptors in rat heart failure after MI. The abnormal adrenergic signaling occurred heterogeneously in terms of ventricular distribution and time course after MI.

Determination of saccharides in sake by high-performance liquid chromatography with polarized photometric detection

A high-performance liquid chromatographic method has been developed for the determination of saccharides in sake, an alcoholic beverage brewed from rice. Saccharides in sake were separated on a normal phase (carbamoyl bonded silica) column using a linear gradient elution of water in acetonitrile. Seven saccharides, glucose, maltose, isomaltose, maltotriose, panose, isomaltotriose and ethyl alpha-D-glucoside, were determined by a polarized photometric detector. Unidentified peaks suggesting saccharides with polymerization degrees over 4 were also observed. The proposed method did not require any sample clean-up treatment. As an application, saccharide compositions in various kinds of sake were compared.

Prostaglandin D2 as a mediator of allergic asthma

Allergic asthma is caused by the aberrant expansion in the lung of T helper cells that produce type 2 (TH2) cytokines and is characterized by infiltration of eosinophils and bronchial hyperreactivity. This disease is often triggered by mast cells activated by immunoglobulin E (IgE)-mediated allergic challenge. Activated mast cells release various chemical mediators, including prostaglandin D2 (PGD2), whose role in allergic asthma has now been investigated by the generation of mice deficient in the PGD receptor (DP). Sensitization and aerosol challenge of the homozygous mutant (DP-/-) mice with ovalbumin (OVA) induced increases in the serum concentration of IgE similar to those in wild-type mice subjected to this model of asthma. However, the concentrations of TH2 cytokines and the extent of lymphocyte accumulation in the lung of OVA-challenged DP-/- mice were greatly reduced compared with those in wild-type animals. Moreover, DP-/- mice showed only marginal infiltration of eosinophils and failed to develop airway hyperreactivity. Thus, PGD2 functions as a mast cell-derived mediator to trigger asthmatic responses.

Possible paracrine growth of adenocarcinoma of the stomach induced by granulocyte colony stimulating factor produced by squamous cell carcinoma of the oesophagus

Synchronous cancers of the oesophagus and stomach diagnosed in a patient showing pronounced leucocytosis were examined for production of granulocyte colony stimulating factor (G-CSF) and expression of G-CSF receptor. Whereas enzyme immunoassay of tissue extracts showed that the oesophageal carcinoma produced G-CSF, the gastric cancer did not. However, the gastric tumour showed G-CSF receptor expression on immunohistochemical examination of sections. These findings suggest that the oesophageal cancer promoted gastric cancer growth by paracrine mechanisms involving G-CSF.

Signal transduction induced in Trypanosoma cruzi metacyclic trypomastigotes during the invasion of mammalian cells

Penetration of Trypanosoma cruzi into mammalian cells depends on the activation of the parasite's protein tyrosine kinase and on the increase in cytosolic Ca2+ concentration. We used metacyclic trypomastigotes, the T. cruzi developmental forms that initiate infection in mammalian hosts, to investigate the association of these two events and to identify the various components of the parasite signal transduction pathway involved in host cell invasion. We have found that i) both the protein tyrosine kinase activation, as measured by phosphorylation of a 175-kDa protein (p175), and Ca2+ mobilization were induced in the metacyclic forms by the HeLa cell extract but not by the extract of T. cruzi-resistant K562 cells; ii) treatment of parasites with the tyrosine kinase inhibitor genistein blocked both p175 phosphorylation and the increase in cytosolic Ca2+ concentration; iii) the recombinant protein J18, which contains the full-length sequence of gp82, a metacyclic stage surface glycoprotein involved in target cell invasion, interfered with tyrosine kinase and Ca2+ responses, whereas the monoclonal antibody 3F6 directed at gp82 induced parasite p175 phosphorylation and Ca2+ mobilization; iv) treatment of metacyclic forms with phospholipase C inhibitor U73122 blocked Ca2+ signaling and impaired the ability of the parasites to enter HeLa cells, and v) drugs such as heparin, a competitive IP3-receptor blocker, caffeine, which affects Ca2+ release from IP3-sensitive stores, in addition to thapsigargin, which depletes intracellular Ca2+ compartments and lithium ion, reduced the parasite infectivity. Taken together, these data suggest that protein tyrosine kinase, phospholipase C and IP3 are involved in the signaling cascade that is initiated on the parasite cell surface by gp82 and leads to Ca2+ mobilization required for target cell invasion.

Acoustic injury in mice: 129/SvEv is exceptionally resistant to noise-induced hearing loss

129/SvEv is an inbred mouse strain popular for use in genetic knockout studies. Here, we compare normal auditory function and vulnerability to acoustic injury in wild-type mice of the 129/SvEv vs. CBA/CaJ strains. Compound action potentials (CAPs) and distortion product otoacoustic emissions (DPOAEs) showed slightly higher thresholds for 129/SvEv re CBA/CaJ, especially at frequencies >20 kHz. Middle-ear motion (i.e. umbo velocity) was similar in the two strains; although frequencies >20 kHz could not be evaluated. Permanent threshold shift (PTS) and hair cell losses, measured 1 week after high-intensity exposure to an 8-16 kHz noise band, were smaller in129/SvEv at all exposure levels and durations from 97 dB SPLx2 h to 106 dB SPLx8 h. Furthermore, PTS growth with increasing exposure energy was slower in 129/SvEv (<2 dB/dB) than CBA/CaJ (9 dB/dB). These data suggest that the vulnerability differences lie in the inner ear, not the middle ear. Several 129/Sv substrains show age-related hearing loss (AHL): 129/SvEv has not yet been evaluated (Zheng, Q.Y., Johnson, K. R., Erway, L.C., 1999. Assessment of hearing in 80 inbred strains of mice by ABR threshold analyses. Hear. Res. 130, 94-107). Thus, although other strains with AHL, e.g. C57Bl/6J, show increased vulnerability to noise-induced hearing loss (NIHL), pairing of AHL and NIHL vulnerabilities may not be obligatory.

Effect of vitamin E on aspirin-induced gastric mucosal injury in rats

We investigated the effect of vitamin E on aspirin-induced gastric mucosal injury in rats. Twenty-eight male Sprague-Dawley rats were divided into four groups and were fed for 20 weeks with a diet containing <0.1 mg/100 g of alpha-tocopherol (vitamin E-deficient), 2 mg/100 g of alpha-tocopherol (normal and vitamin E-sufficient), or 50 mg/100 g of alpha-tocopherol (vitamin E-supplemented). In vitamin E-deficient rats, oral administration of aspirin (200 mg/kg) plus HCI created more severe hemorrhagic erosions than in other rats. Vitamin E-deficient rats had higher levels of thiobarbituric acid reactive substances, myeloperoxidase activity, and cytokine-induced neutrophil chemoattractant in the gastric mucosa. Flow cytometry showed that CD18 expression on stimulated neutrophils was higher in vitamin E-deficient rats than in vitamin E-supplemented rats. These results suggest that vitamin E protects against aspirin-induced gastric mucosal injury by inhibiting lipid peroxidation and accumulation of activated neutrophils.

Image processing experiments for computer-based three-dimensional reconstruction of neurones from electron micrographs from serial ultrathin sections

This study examined an image processing technique that uses a computer to reconstruct a three-dimensional image of neurones from electron micrographs of serial ultrathin sections. The major problems involved were: (a) a distortion of features in electron micrographs; (b) a significant change of cross-section features of neurones in electron micrographs of neighbouring sections; and (c) disagreement between the electron microscopic section face and the coordinate plane desired for the reconstruction. Electron micrographs of a retinal bipolar cell stained with a biotinylated tracer were used. We corrected the distortion of features by means of a warp, a widely used algorithm in morphing image processing. The change of features between neighbouring electron micrographs was minimized by filling the gaps with an interpolated image produced by a dissolve, another algorithm in morphing, as well as the warp. The distortion of the three-dimensional reconstructed image made by piling up features was corrected by making the image with a wire frame model. Furthermore, in order to estimate a closed contour of features, an active contour model, Snakes, was applied to the electron microscope features. Snakes successfully detected the contour of the target feature, but in some electron microscope images broke into the target feature.

Characterization of the cell adhesion site of Trypanosoma cruzi metacyclic stage surface glycoprotein gp82

The surface glycoprotein gp82, expressed in the insect-stage metacyclic trypomastigotes of Trypanosoma cruzi, has been implicated in mammalian cell invasion. Here we have characterized the cell adhesion site of gp82 by using recombinant proteins and synthetic peptides based on gp82. The recombinant protein Del-4/8, lacking 65 amino acids of gp82 central domain (at positions 257 to 321), was virtually devoid of cell-binding activity and lacked the ability to inhibit parasite invasion, in contrast to J18, the construct containing the full-length gp82 sequence (amino acids 1 to 516). Constructs with shorter deletions, i.e., Del-4 (deleted from 257 to 271) and Del-8 (deleted from 293 to 321), bound to target cells to a significantly lesser degree than did J18. The sites deleted in recombinant proteins Del-4 and Del-8 contained acidic amino acids critical for cell adhesion. Thus, the cell-binding capacity of protein Del-E/D, lacking the glutamic acid (259/260) and aspartic acid (303/304) pairs, was negligible, as was its capacity to inhibit parasite internalization. Of a set of synthetic peptides spanning the gp82 central domain, a 22-mer hybrid peptide, p4/8, formed by two noncontiguous sequences (at positions 257 to 273 and 302 to 306) and containing the four acidic residues, competed with the binding of J18 protein to target cells and significantly inhibited ( approximately 60%) the penetration of parasites. This peptide, generated by the juxtaposition of sequences that are separated by a hydrophobic stretch in the linear molecule, appears to be mimicking a conformation-dependent cell-binding site of gp82. Experiments of antibody competition with a set of 20-mer overlapping peptides mapped the epitope for 3F6, a monoclonal antibody directed to gp82 that inhibits parasite invasion, to the sequence represented by peptide p3 (244 to 263), which has a partial overlap with the cell adhesion site.

Protection of mitochondrial functions against oxidative stresses by isoflavans from Glycyrrhiza glabra

Isoflavan derivatives, glabridin (1), hispaglabridin A (2), hispaglabridin B (3), 4'-Omethylglabridin (4) and 3'-hydroxy-4'-O-methylglabridin (5), isolated from Glycyrrhiza glabra, were investigated for their ability to protect liver mitochondria against oxidative stresses. Mitochondrial lipid peroxidation linked to respiratory electron transport and that induced non-enzymatically were inhibited by these isoflavans. Hispaglabridin A (2) strongly inhibited both peroxidations and 3'-hydroxy-4'-O-methylglabridin (5) was the most effective at preventing NADH-dependent peroxidation. 3'-Hydroxy-4'-O-methylglabridin (5) protected mitochondrial respiratory enzyme activities against NADPH-dependent peroxidation injury. Dihydroxyfumarate-induced mitochondrial peroxidation was also prevented by this isoflavan. Isoflavans from G. glabra were shown to be effective in protecting mitochondrial function against oxidative stresses.

Origin of fan palm (Livistona chinensis R. Br. var. subglobosa Becc.) in Aoshima, Japan

RAPD and RFLP analyses were carried out to determine the origin of Livistona chinensis R. Br. var. subglobosa Becc. from Iriomotejima, Ishigakijima, Okinawa, Yakushima, Tanegashima, Cape Sata, Cape Toi, Tsukishima, and Aoshima, Japan. RAPD data obtained using 5 random primers were clustered using UPGMA or the neighbor-joining method. Each population was classified into three clusters based on the phylogenetic tree. L. chinensis plants from Yakushima, Tanegashima and Cape Sata belonged to the isologous cluster, and those from Ishigakijima and Okinawa are contained in a different cluster. L. chinensis from Okinawa and Ishigakijima could be differentiated by being the oldest based on the genetic distance. The area that covers Ishigakijima and Okinawa is thought to be the origin of L. chinensis. L. chinensis plants from Iriomotejima were contained in the same cluster as those from Aoshima. The phylogenetic trees constructed by both RAPD and RFLP analyses indicate the possibility that seeds or green woods of L. chinensis were dispersed by tidal current from the south field around Irlomotejima, and they were washed to Aoshima and established gradually. Therefore, we support the drifting-ashore-naturalized-plant hypothesis on the origin of L. chinensis in Aoshima.

Characterization of a flavinogenic mutant of methanol yeast Candida boidinii and its extracellular secretion of riboflavin

A flavinogenic mutant was derived from Candida boidinii by mutagenesis. The mutant was smaller than the wild type, did not grow on a minimal medium, and required l-tryptophan, l-leucine, inositol, and nicotinate for growth. The mutant was defective in the oxidative pentose phosphate pathway, lacking glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. The specific activities of the transaldolase and transketolase of the mutant were higher than those of the wild type. These high activities might direct the flux of the carbon source to the nonoxidative pathway with formation of a large amount of pentose phosphates, increasing riboflavin synthesis. Under microaerobic conditions at 25 degrees C, 90 mg/l riboflavin was obtained.

Alpha-tocopherol protects against monocyte Mac-1 (CD11b/CD18) expression and Mac-1-dependent adhesion to endothelial cells induced by oxidized low-density lipoprotein

Alpha-tocopherol supplementation is reported to protect against cardiovascular disease and to influence cells involved in atherogenesis, such as monocytes. Interactions between monocytes and vascular endothelial cells occur early in atherogenesis, and adhesion is mediated by integrins. We evaluated the effects of alpha-tocopherol on expression of Mac-1 (CD11b/CD18) by monocytes after stimulation with oxidized low-density lipoprotein (LDL), which is implicated as a potent chemotactic agent in atherogenesis. Incubation of whole blood with oxidized LDL (100 microg/ml) increased Mac-1 expression on monocytes, and preincubation with alpha-tocopherol reduced this upregulation in a concentration dependent manner. In another experiment, whole blood was obtained from healthy adult volunteers after 10 days of alpha-tocopherol administration (600 mg/day) and was incubated with oxidized LDL (100 microg/ml). There was a decrease in the upregulation of Mac-1 compared with that measured before administration. Adherence of oxidized LDL-stimulated monocytes to human umbilical vein endothelial cells was reduced by pretreatment with alpha-tocopherol, and was also inhibited by an anti-CD18 monoclonal antibody. Experiments with protein kinase C inhibitors suggested that reduction of Mac-1 upregulation by alpha-tocopherol was secondary to a decrease of protein kinase C activity. In conclusion, alpha-tocopherol suppressed the upregulation of Mac-1 expression on monocytes by oxidized LDL.