Induction of apoptosis in human leukaemic cell lines K562, HL60 and U937 by diethylhexylphthalate isolated from Aloe vera Linne

We investigated the effect of diethylhexylphthalate (DEHP) from Aloe vera Linne on the apoptosis of human leukaemic cell lines K562, HL60 and U937 to examine its pharmacological activity. At a level of 10 microg mL(-1) DEHP a significant anti-leukaemic effect was observed for all three cell lines, as measured by clonogenic assay. After treatment with 10 microg mL(-1) DEHP for 4 h, agarose gel electrophoresis and flow cytometric analysis confirmed the occurrence of apoptosis. These results indicate that DEHP isolated from Aloe vera Linne has a potent antileukaemic effect, and thus represents a new type of pharmacological activity with respect to human leukaemic cells.

Molecular cloning of a gene encoding the thermoactive levansucrase from Rrahnella aquatilis and its growth phase-dependent expression in Eescherichia coli

A levansucrase gene (lsrA) from Rahnella aquatilis ATCC33071 was isolated from a genomic library and the nucleotide sequence of the lsrA structural gene was determined. lsrA is composed of 1248 bp and encodes 415 amino acid residues with a calculated molecular mass of 45.9 kDa. Although the amino acid sequence of lsrA gene showed good conservation with the sequences of reported levansucrases and of the conserved regions thought to be implicated in the enzyme activity, comparison of the deduced amino acid sequences certified the dissimilarity of the proteins from Gram-negative and Gram-positive bacteria. The lsrA gene was expressed from its own promoter in Escherichia coli in an active form. The lsrA expression in E. coli-pRL1CPR was affected by the growth phase of cells: it was repressed in the early phase of growth, but was significantly stimulated during the entrance of cells into the late phase of growth. The growth-phase-dependent fashion of lsrA expression was altered in a constitutive-like fashion by the deletion of an upstream region of lsrA (pNd137), suggesting that the growth-phase dependent expression of lsrA was mediated by the deleted upstream region.

Modulation of endothelin-1 expression in pulmonary epithelial cell line (A549) after exposure to RSV

Respiratory syncytial virus (RSV) is one of the most important respiratory tract pathogens in infants and young children. The airway epithelial cells are the primary target cells for RSV infection. The airway epithelial layer is not only a physical barrier, but also plays a role in a synthesis of a variety of major inflammatory cytokines (IL-6, IL-8, GM-CSF etc.) as previously reported. Endothelin-1 (ET-1) is a potent bronchoconstrictor and vasoconstrictor factor, and involved in pathogenesis of various diseases of the respiratory tract. We hypothesized that RSV may induce the release of ET-1 from the bronchial epithelial cell line. No previous data is available regarding association between RSV infection and ET-1 release. We evaluated the effect of RSV with different concentrations of RSV (MOI 0.1, 1 and 3 pfu/cell) on bronchial epithelial cell line (A549) and measured the production of ET-1 at both protein and mRNA level. A549 cells were treated with different conditions by using LPS, heat-inactivated RSV, RSV or medium alone as control. We observed time-dependent ET-1 release by RSV-infected A549 cells at 4 h, 24 h and maximum at 72 h. ET-1 was expressed in unstimulated A549 cells and was further increased by RSV. RSV with concentration MOI 0.1 (pfu/cell) and LPS appeared to have strongest stimulation on production of ET-1. In addition, ET-1 mRNA was increased significantly by 16 h and decreased to relatively low-level at 24 h. These experiments suggested that airway epithelial cells might play a role in the local airway smooth muscle tone through the production of endothelin-1 during RSV infection.

Eligibility of antigenic-peptide-pre-loaded and fixed adhesive peripheral blood cells for induction of cytotoxic T lymphocytes from cancer patients with elevated serum levels of carcinoembryonic antigen

The inducibility of cytotoxic T lymphocytes (CTL) that react with carcinoembryonic antigen (CEA) was tested in cancer patients with elevated (more than 5 ng/ml) serum CEA levels when antigen presentation was carried out with paraformaldehyde-fixed adhesive peripheral blood mononuclear cells (PBMC) from the patient that had been pre-loaded with CEA652(9), an HLA-A2402-restricted tumor antigenic peptide derived from CEA. By culturing fresh autologous PBMC on the fixed cell layer in medium containing interleukin-1, -2, -4 and -6. three out of eight patients developed CTL. The CTL from two of these patients killed CEA-protein-producing gastric cancer cells carrying HLA-A2402 and the cells from the remaining patient killed CEA-non-producing stomach cancer cells pre-loaded with CEA652(9). The results suggest that a single antigenic peptide on the fixed adhesive cells will allow the ex vivo induction of peptide-reactive CTL that are easier to handle and allow antigen presentation without tedious preculture of the "professional" antigen-presenting dendritic-cells.

Cadmium blocks hypoxia-inducible factor (HIF)-1-mediated response to hypoxia by stimulating the proteasome-dependent degradation of HIF-1alpha

Cadmium is a substantial industrial and environmental pollutant which seriously impairs erythropoiesis. Cd has been demonstrated to aggravate anemia by suppressing erythropoietin gene expression in anemic patients. As hypoxic induction of erythropoietin mRNA depends on a transcription factor, hypoxia-inducible factor 1 (HIF-1), we hypothesized that Cd suppresses the hypoxic activation of HIF-1. In hypoxic Hep3B cells, all mRNAs of various genes, which are known to be upregulated by HIF-1 activation under hypoxia, were suppressed by Cd in a dose-dependent manner. Cd inhibited the hypoxia-induced activity of luciferase in 293 cells which was transfected with a reporter plasmid carrying a hypoxia response element. By electrophoretic mobility gel shift assay, Cd inhibited the DNA-binding activity of HIF-1 in hypoxic Hep3B cells. Cd reduced the amount of HIF-1alpha protein in hypoxia, whereas it didn't affect HIF-1 alpha mRNA levels. Moreover, Cd inhibited HIF-1alpha accumulation induced by cobalt and desferrioxamine. Antioxidants and a proteasome inhibitor prevented the HIF-1alpha degradation caused by Cd. The possibility that oxidative stress mediates this action of Cd was examined. Cd didn't affect protein oxidation and reduced glutathione levels in hypoxic cells. These results indicate that Cd triggers a redox/proteasome-dependent degradation of HIF-1alpha protein, reducing HIF-1 activity and in turn suppressing the hypoxic induction of hypoxia-inducible genes.

Paenibacillus koreensis sp. nov., a new species that produces an iturin-like antifungal compound

A bacterial strain, YC300T, that produces an iturin-like antifungal antibiotic was isolated from compost and identified as member of the genus Paenibacillus. Gram reaction of the strain was variable depending upon growth stages and culture media. Three different types of colonies were developed on tryptic soy agar. The organism was facultatively anaerobic and grew at 50 degrees C. The DNA G+C content was 54 mol % and anteiso-C15:0 was the major fatty acid. A 0.9 kb fragment was produced by PCR amplification of strain YC300T DNA using primers PAEN515F and 1377R. Levels of 16S rDNA similarity between strain YC300T and other Paenibacillus species were between 89.8 and 94.8%. Phylogenetically, strain YC300T formed a significant monophyletic clade with Paenibacillus validus. It is clear from polyphasic evidence that the isolate should be classified as Paenibacillus koreensis sp. nov., the type strain of which is YC300T (= KCTC 2393T, KCCM 40903T).

Expression of TRAIL (Apo2L), DR4 (TRAIL receptor 1), DR5 (TRAIL receptor 2) and TRID (TRAIL receptor 3) genes in multidrug resistant human acute myeloid leukemia cell lines that overexpress MDR 1 (HL60/Tax) or MRP (HL60/AR)

Previously we have reported a differential expression of CD95/CD95L and Bcl-2 family of genes in multidrug resistant tumor cells. TRAIL, a member of the TNF receptor family, induces apoptosis in many tumor cells by binding to DR4 (TRAIL receptor 1) and DR5 (TRAIL receptor 2). In contrast, TRAIL-induced apoptosis is prevented by a decoy receptor (DcR1, TRID or TRAIL receptor 3). In the present study, we compared the expression of TRAIL, DR4, DR5, and TRID between a drug sensitive HL60, a myeloid leukemia cell line, and its multidrug resistant (MDR) sublines that either overexpressed MDR 1 gene (HL60/Tax) or MRP gene (HL60/AR), using RT-PCR. TRAIL mRNA was expressed in HL60 cells but was present in low levels in HL60/AR cells and was completely lacking in HL60/Tax cells. Both DR4 and DR5 were undetectable in HL60/Tax but were present at comparable levels in HL60/AR and drug sensitive HL60 cells. TRID were absent in HL60 and HL60/Tax cells, but was present in low but comparable levels in peripheral blood mononuclear cells and HL60/AR cells. These data suggest that the multidrug resistance in MDR HL60 cell lines, regardless of overexpression of MDR 1 or MRP, may be due to different mechanisms. In HL60/AR cells it appears that MDR may be due to decreased expression of TRAIL and constitutive expression of TRID, whereas in HL60/Tax cells, MDR could be due to the absence of TRAIL and/or DR4 and DR5.

Human chorionic gonadotropin induces nitric oxide synthesis by murine microglia

This study investigated the effects of human chorionic gonadotropin (hCG) on the synthesis of nitric oxide (NO) in murine neonatal microglial cells. When hCG was used in combination with interferon-gamma (IFN-gamma), there was a marked cooperative induction of NO synthesis in a dose-dependent manner. This increase in NO synthesis was reflected as an increased amount of iNOS protein. The increase of NO synthesis by IFN-gamma-plus-hCG was associated with the increase of tumor necrosis factor-alpha (TNF-alpha) secretion and hCG-induced NO production was decreased by the treatment with anti-murine TNF-alpha neutralizing antibody. This study provides evidence that hCG activates expression of iNOS protein in murine microglial cells accompanied by NO accumulation via pathway dependent on L-arginine in the culture medium, and further offers that TNF-alpha acts on the NO synthesis from IFN-gamma-primed murine microglial cells.

Metastatic tumors in the sellar and parasellar regions: clinical review of four cases

Metastatic tumors in the sellar and parasellar regions are uncommon and rarely detected in clinical practice. We present four cases of sellar and parasellar metastatic tumors, which metastasized from distant organ in one case and extended directly from adjacent structures in three. Common presenting symptoms were cranial neuropathies, headache and facial pain. Invasion into the cavernous sinus was noted in all cases. We report rare cases of sellar and parasellar metastases. Also, we should consider the possibility of metastasis in these regions for patients who showed the above clinical presentations in systemic cancer patients. In extensive diseases, transient symptomatic relief could be obtained by direct surgical management, even in restricted degree.

Characterization of a bifunctional enzyme fusion of trehalose-6-phosphate synthetase and trehalose-6-phosphate phosphatase of Escherichia coli

To test the effect of the physical proximity of two enzymes catalyzing sequential reactions, a bifunctional fusion enzyme, TPSP, was constructed by fusing the Escherichia coli genes for trehalose-6-phosphate (T6P) synthetase (TPS) and trehalose-6-phosphate phosphatase (TPP). TPSP catalyzes the sequential reaction in which T6P is formed and then dephosphorylated, leading to the synthesis of trehalose. The fused chimeric gene was overexpressed in E. coli and purified to near homogeneity; its molecular weight was 88,300, as expected. The K(m) values of the TPSP fusion enzyme for the sequential overall reaction from UDP-glucose and glucose 6-phosphate to trehalose were smaller than those of an equimolar mixture of TPS and TPP (TPS/TPP). However, the k(cat) values of TPSP were similar to those of TPS/TPP, resulting in a 3.5- to 4.0-fold increase in the catalytic efficiency (k(cat)/K(m)). The K(m) and k(cat) values of TPSP and TPP for the phosphatase reaction from T6P to trehalose were quite similar. This suggests that the increased catalytic efficiency results from the proximity of TPS and TPP in the TPSP fusion enzyme. The thermal stability of the TPSP fusion enzyme was quite similar to that of the TPS/TPP mixture, suggesting that the structure of each enzyme moiety in TPSP is unperturbed by intramolecular constraint. These results clearly demonstrate that the bifunctional fusion enzyme TPSP catalyzing sequential reactions has kinetic advantages over a mixture of both enzymes (TPS and TPP). These results are also supported by the in vivo accumulation of up to 0.48 mg of trehalose per g of cells after isopropyl-beta-D-thiogalactopyranoside treatment of cells harboring the construct encoding TPSP.

Effects of high-fat diet and exercise training on intracellular glucose metabolism in rats

We examined the effects of high-fat diet (HFD) and exercise training on insulin-stimulated whole body glucose fluxes and several key steps of glucose metabolism in skeletal muscle. Rats were maintained for 3 wk on either low-fat (LFD) or high-fat diet with or without exercise training (swimming for 3 h per day). After the 3-wk diet/exercise treatments, animals underwent hyperinsulinemic euglycemic clamp experiments for measurements of insulin-stimulated whole body glucose fluxes. In addition, muscle samples were taken at the end of the clamps for measurements of glucose 6-phosphate (G-6-P) and GLUT-4 protein contents, hexokinase, and glycogen synthase (GS) activities. Insulin-stimulated glucose uptake was decreased by HFD and increased by exercise training (P < 0.01 for both). The opposite effects of HFD and exercise training on insulin-stimulated glucose uptake were associated with similar increases in muscle G-6-P levels (P < 0.05 for both). However, the increase in G-6-P level was accompanied by decreased GS activity without changes in GLUT-4 protein content and hexokinase activities in the HFD group. In contrast, the increase in G-6-P level in the exercise-trained group was accompanied by increased GLUT-4 protein content and hexokinase II (cytosolic) and GS activities. These results suggest that HFD and exercise training affect insulin sensitivity by acting predominantly on different steps of intracellular glucose metabolism. High-fat feeding appears to induce insulin resistance by affecting predominantly steps distal to G-6-P (e.g., glycolysis and glycogen synthesis). Exercise training affected multiple steps of glucose metabolism both proximal and distal to G-6-P. However, increased muscle G-6-P levels in the face of increased glucose metabolic fluxes suggest that the effect of exercise training is quantitatively more prominent on the steps proximal to G-6-P (i.e., glucose transport and phosphorylation).

Anti-leukaemic and anti-mutagenic effects of di(2-ethylhexyl)phthalate isolated from Aloe vera Linne

Extracts of Aloe vera Linne have been found to exhibit cytotoxicity against human tumour cell lines. This study examines the anti-tumour effects of di(2-ethylhexyl)phthalate (DEHP) isolated from Aloe vera Linne, in human and animal cell lines. Its anti-mutagenic effects were examined using Salmonella typhimurium TA98 and TA100 strains. Growth inhibition was specifically exerted by DEHP against three leukaemic cell lines at concentrations below 100 microg mL(-1). At 100 microg mL(-1) DEHP, K562, HL60 and U937 leukaemic cell lines showed growth inhibition of 95, 97 and 95%, respectively. DEHP exhibited an inhibitory activity of 74, 83 and 81%, respectively, in K562, HL60 and U937 cell lines at a concentration of 10 microg mL(-1). At a concentration of 1 microg mL(-1), DEHP exerted an inhibitory activity of 50, 51 and 52%, respectively, in K562, HL60 and U937. In a normal cell line, MDBK, DEHP exerted 30% growth inhibition at a concentration of 100 microg mL(-1), and showed no inhibitory activity at concentrations below 50 microg mL(-1). It was found that DEHP exerted anti-mutagenic activity in the Salmonella mutation assay. The number of mutant colonies of Salmonella typhimurium strain TA98 upon exposure to AF-2 (0.2 microg/plate) decreased in a concentration-dependent manner in the presence of different DEHP concentrations (decreasing to 90.4, 83.9, 75.4, 69.6 and 46.9%, respectively, for DEHP concentrations of 100, 50, 10, 5 and 1 microg/plate). In the case of Salmonella typhimurium strain TA100, DEHP reduced AF-2-induced mutagenicity at 1, 5, 10, 50 and 100 microg/plate to 57.4, 77.5, 80.0, 89.0 and 91.5%, respectively. The isolated compound from Aloe vera Linne, DEHP, was considered to be the active principle responsible for anti-leukaemic and anti-mutagenic effects in-vitro.

RNA motifs that determine specificity between a viral replicase and its promoter

The 3' end of brome mosaic virus RNA contains a tRNA-like sequence that directs its RNA synthesis. A stem loop structure in this sequence, stem loop C (SLC), was investigated using NMR, and correlated with its ability to direct RNA synthesis by its replicase. SLC consists of two discrete domains, a flexible stem with an internal loop and a rigid stem containing a 5'-AUA-3' triloop. Efficient RNA synthesis requires the sequence on only one side of the flexible stem and a specific compact conformation of the triloop. A high resolution structure of the triloop places the 5' adenine out in solution, and the 3' adenine within the triloop, held tightly through stacking and unusual hydrogen bonds. This high resolution structure of an RNA promoter from a (+)-strand RNA virus provides new insights into how the RNA-dependent RNA polymerase binds to the RNA to initiate synthesis.

The CC chemokine CK beta-11/MIP-3 beta/ELC/Exodus 3 mediates tumor rejection of murine breast cancer cells through NK cells

CK beta-11 chemoattracts T cells, B cells, dendritic cells, macrophage progenitors, and NK cells and facilitates dendritic cell and T cell interactions in secondary lymphoid tissues. We hypothesized that expression of CK beta-11 in tumor cells may generate antitumor immunity through these interactions. After transduction with the retroviral vector L(CK beta 11)SN, the murine breast cancer cell line C3L5 (C3L5-CK beta 11) showed expression of retroviral mRNA by Northern analysis and production of functional CK beta-11 by chemotaxis of human NK cells to C3L5-CK beta 11 supernatant. Only 10% of mice injected with C3L5-CK beta 11 developed tumors, compared with 100% of mice injected with a transduced control C3L5 line (C3L5-G1N). Importantly, the in vitro growth characteristics of the CK beta-11-transduced cell line were unaffected, suggesting the difference in growth in vivo was a result of chemokine production. Vaccination with C3L5-CK beta 11 partially protected animals from parental C3L5 challenge. Immunodepletion with anti-asialo-GM1 or anti-CD4 during C3L5-CK beta 11 vaccination significantly reduced CK beta-11 antitumor activity compared with control and anti-CD8-treated groups. Splenocytes from NK-depleted animals transferred the acquired immunity generated with C3L5-CK beta 11 vaccination, while splenocytes from the CD4-depleted animals did not. These results indicate, for the first time, that expression of CK beta-11 in a breast cancer cell line mediates rejection of the transduced tumor through a mechanism involving NK and CD4+ cells. Furthermore, CK beta-11-transduced tumor cells generate long-term antitumor immunity that requires CD4+ cells. These studies demonstrate the potential role of CK beta-11 as an adjuvant in stimulating antitumor responses.

Impact of abnormal uptakes in bone scan on the prognosis of patients with lung cancer

The detection of bone metastases is important in the management of patients with lung cancer because bone metastasis has a major impact on the prognosis and choice of treatment modality. Bone scan has been widely used for early detection of bone metastases but its low specificity complicates confirmation of bone scan findings. To evaluate the effects of abnormal bone scan findings on the prognosis of patients with lung cancer, we retrospectively analyzed the effect of abnormal uptakes on the prognosis of patients with primary lung cancer. The overall survival of patients with abnormal bone uptake was not significantly different from those without abnormal uptake. However, the patients with more than two abnormal bone uptakes had significantly shorter survival than those with no abnormal uptake (P<0.05). To confirm the effect of abnormal bone uptakes on survival, we compared the survival curves of three patient groups without knowledge of bone scan findings: group A, stage I-IIIB with more than two abnormal bone uptakes (potential stage IV); group B, stage IIIB with no abnormal bone uptake (true stage IIIB); and group C, stage IV with no abnormal bone uptake. Group A revealed shorter survival than group B (P<0.05). But, there was no significant difference in survival times between group A and group C. In the Cox regression analysis, the presence of more than two abnormal bone uptakes was a significant prognostic factor (P=0.0277), together with performance status, stage, and albumin. These results suggest that one or two abnormal bone uptake at diagnosis did not affect overall survival of the patients, and that the patients with more than two abnormal bone uptakes are considered as clinical stage IV because of high probability of bone metastases.

Effect of a lipidic extract from lepidium meyenii on sexual behavior in mice and rats

OBJECTIVES

To determine the effect of oral administration of a purified lipidic extract from Lepidium meyenii (MacaPure M-01 and M-02) on the number of complete intromissions and mating in normal mice, and on the latent period of erection (LPE) in rats with erectile dysfunction.

METHODS

Mice and rats were randomly divided into several experimental and control groups. A 10% ethanol suspension of M-01 and M-02 was orally administered for 22 days to the experimental groups according to the dosage specified by the experimental design. On day 22, 30 minutes after the dose was administered to the male mice, 2 virgin female mice were placed with 1 male mouse. The number of complete intromissions of each male mouse in 3 hours was recorded. In an assessment of 1 day of mating, each male mouse was cohabited with 5 estrous female mice overnight. The number of sperm-positive females was recorded. The LPE was measured to assess the sexual function in rats with erectile dysfunction. By using a YSD-4G multifunction instrument, an electric pulse at 20 V was applied to stimulate the rat's penis, and the duration from the start of the stimulus to full erection was measured in seconds as the LPE.

RESULTS

In the normal male mice, the number of complete intromissions during the 3-hour period was 16.33 +/- 1.78, 46.67 +/- 2.39, and 67.01 +/- 2.55 for the control group, M-01 group, and M-02 group, respectively. In the assessment of mating, the number of sperm-positive females increased from 0.6 +/- 0.7 in the control group to 1.5 +/- 0.5 in the M-01 experimental group. The LPE of male rats with erectile dysfunction was 112 +/- 13 seconds with a regular diet (control group). The oral administration of M-01 at a dose of 180 or 1800 mg/kg body weight and M-02 at a dose of 45, 180, or 1800 mg/kg body weight reduced the LPE to 54 +/- 12 seconds, 54 +/- 13 seconds, 71 +/- 12 seconds, 73 +/- 12 seconds, and 41 +/- 13 seconds, respectively. The LPE of the surgical rats treated with M-01 at the lowest dose (45 mg/kg) was 121 +/- 12 seconds; thus, the change was not significant.

CONCLUSIONS

Oral administration of M-01 and M-02 enhanced the sexual function of the mice and rats, as evidenced by an increase in the number of complete intromissions and the number of sperm-positive females in normal mice, and a decrease in the LPE in male rats with erectile dysfunction. The present study reveals for the first time an aphrodisiac activity of L. meyenii, an Andean Mountain herb.

Refolding and purification of Zymomonas mobilis levansucrase produced as inclusion bodies in fed-batch culture of recombinant Escherichia coli

Zymomonas mobilis levansucrase was overproduced by the fed-batch culture of recombinant Escherichia coli harboring a novel expression system that is constitutively expressed by the promoter from the Rahnella aquatilis levansucrase gene. Most of the levansucrase was produced as inclusion bodies in the bacterial cytoplasm, accounting for approximately 20% of the total cellular protein. Refolding after complete denaturation by high concentrations of urea or guanidine hydrochloride was not successful, resulting in large amounts of insoluble aggregates. During the development of the refolding method, it was found that direct solubilization of the inclusion bodies with Triton X-100 reactivated the enzyme, with a considerable refolding efficiency. About 65% of inclusion body levansucrase was refolded into active levansucrase in the renaturation buffer containing 4% (v/v) Triton X-100. The in vitro refolded enzyme was purified to 95% purity by single-step DEAE-Sepharose ion exchange chromatography. Triton X-100 was removed by this ion exchange chromatography.

A tetrodotoxin-producing Vibrio strain, LM-1, from the puffer fish Fugu vermicularis radiatus

Identification of tetrodotoxin (TTX) and its derivatives produced from a Vibrio strain in the intestine of the puffer fish Fugu vermicularis radiatus was performed by thin-layer chromatography, electrophoresis, high-performance liquid chromatography, and gas chromatography-mass spectrometry, together with a mouse bioassay for toxicity. It was demonstrated that the isolated bacterium produced TTX, 4-epi-TTX, and anhTTX during cultivation, suggesting that Vibrio strains are responsible for the toxification of the puffer fish.

Relationship between endometrial estrogen and progesterone receptors, and sonographic endometrial appearance in the preovulatory phase

OBJECTIVES

The purpose of the present study is to evaluate the relationship between endometrial concentrations of estrogen receptor (ER) and progesterone receptor (PR), and sonographic endometrial findings in the preovulatory phase of menstrual cycle.

STUDY DESIGN

In 45 cycles of 45 infertile women with tubal factor only, transvaginal sonographic assessments and biopsy for immunohistochemical staining of the endometrium were made in the preovulatory phase of unstimulated, normal menstrual cycle. Immunohistochemical localization of ER and PR was scored according to intensity of staining and proportion of cells specifically stained in glandular epithelium and stroma, and the results were analysed according to the sonographic endometrial thickness (< 6 mm, 6-10 mm, or > 10 mm) and patterns. Endometrial patterns were classified as A, centrally hyperechogenic triple-line pattern or non-A, not triple-line.

RESULTS

There were no significant differences in the endometrial thickness, serum estradiol level and serum progesterone level between A and non-A groups. The receptor scores of epithelial and stromal ER and epithelial PR were comparable in A and non-A groups. However, the receptor score of stromal PR was significantly higher in A group, with 4.8 +/- 1.4 compared with 2.7 +/- 1.7 in non-A group (p < 0.001). There were no differences in the receptor scores of epithelial ER, epithelial PR, stromal ER and stromal PR among the 3 groups according to the endometrial thickness.

CONCLUSIONS

This study suggests that high PR expression in endometrial stroma could be related to the sonographic triple-line or multilayered pattern of endometrium in the preovulatory period.

Biphasic effects of dithiocarbamates on the activity of nuclear factor-kappaB

Dithiocarbamates are well-known antioxidants and nuclear factor-kappaB (NF-kappaB) inhibitors. Recently, they have been characterized as zinc ionophores. Concentration-dependent biphasic effects of dithiocarbamates on NF-kappaB activity have been widely reported. We studied the mechanism of this phenomenon in relation to Zn(2+) influx. Two dithiocarbamates, pyrrolidine dithiocarbamate and diethyldithiocarbamate, showed concentration-dependent biphasic effects in inhibiting NF-kappaB activation in cerebral endothelial cells. These unique effects of dithiocarbamates on NF-kappaB were tightly linked to their ability to elevate intracellular Zn(2+)500 microM), dithiocarbamates started to lose their ability to promote Zn(2+) influx and to inhibit NF-kappaB activation. These results might provide insight into the appropriate use of dithiocarbamates in various disorders.

Azotobacter vinelandii nitrogenases containing altered MoFe proteins with substitutions in the FeMo-cofactor environment: effects on the catalyzed reduction of acetylene and ethylene

Altered MoFe proteins of Azotobacter vinelandii Mo-nitrogenase, with amino acid substitutions in the FeMo-cofactor environment, were used to probe interactions among C(2)H(2), C(2)H(4), CO, and H(2). The altered MoFe proteins used were the alpha-195(Asn) or alpha-195(Gln) MoFe proteins, which have either asparagine or glutamine substituting for alpha-histidine-195, and the alpha-191(Lys) MoFe protein, which has lysine substituting for alpha-glutamine-191. On the basis of K(m) determinations, C(2)H(2) was a particularly poor substrate for the nitrogenase containing the alpha-191(Lys) MoFe protein. Using C(2)D(2), a correlation was shown between the stereospecificity of proton addition to give the products, cis- and trans-C(2)D(2)H(2), and the propensity of nitrogenase to produce ethane. The most extensive loss of stereospecificity occurred with nitrogenases containing either the alpha-195(Asn) or the alpha-191(Lys) MoFe proteins, which also exhibited the highest rate of ethane production from C(2)H(2). These data are consistent with the presence of a common ethylenic intermediate on the enzyme, which is responsible for both ethane production and loss of proton-addition stereochemistry. C(2)H(4) was not a substrate of the nitrogenase with the alpha-191(Lys) MoFe protein and was a poor substrate of the nitrogenases incorporating either the wild-type or the alpha-195(Gln) MoFe protein, both of which had a low V(max) and high K(m) (120 kPa). Ethylene was a somewhat better substrate for the nitrogenase with the alpha-195(Asn) MoFe protein, which exhibited a K(m) of 48 kPa and a specific activity for C(2)H(6) formation from C(2)H(4) 10-fold higher than the others. Neither the wild-type nitrogenase nor the nitrogenase containing the alpha-195(Asn) MoFe protein produced cis-C(2)D(2)H(2) when turned over under trans-C(2)D(2)H(2). These results suggest that the C(2)H(4)-reduction site is affected by substitution at residue alpha-195, although whether the effect is related to the substrate-reduction site directly or is mediated through disturbance of the delivery of electrons/protons is unclear. Ethylene inhibited total electron flux, without uncoupling MgATP hydrolysis from electron transfer, to a similar extent for all four A. vinelandii nitrogenases. This observation indicates that this C(2)H(4) flux-inhibition site is remote from the C(2)H(4)-reduction site. Added CO eliminated C(2)H(4) reduction but did not fully relieve its electron-flux inhibition with all four A. vinelandii nitrogenases, supporting the suggestion that electron-flux inhibition by C(2)H(4) is not directly connected to C(2)H(4) reduction. Thus, C(2)H(4) has two binding sites, and the presence of CO affects only the site at which it binds as a substrate. When C(2)H(2) was added, it also eliminated C(2)H(6) production from C(2)H(4) and also did not relieve electron-flux inhibition fully. Thus, C(2)H(2) and C(2)H(4) are likely reduced at the same site on the MoFe protein. Two schemes are presented to integrate the results of the interactions of C(2)H(2) and C(2)H(4) with the MoFe proteins.

Production of recombinant snakehead rhabdovirus: the NV protein is not required for viral replication

Snakehead rhabdovirus (SHRV) affects warm water fish in Southeast Asia and belongs to the genus Novirhabdovirus by virtue of its nonvirion gene (NV). Because SHRV grows best at temperatures between 28 and 31 degrees C, we were able to use the T7 expression system to produce viable recombinant SHRV from a cloned cDNA copy of the viral genome. Expression of a positive-strand RNA copy of the 11, 550-nucleotide SHRV genome along with the viral nucleocapsid (N), phosphoprotein (P), and polymerase (L) proteins resulted in the generation of infectious SHRV in cells preinfected with a vaccinia virus vector for T7 polymerase expression. Recombinant virus production was verified by detection of a unique restriction site engineered into the SHRV genome between the NV and L genes. Since we were now able to begin examining the function of the NV gene, we constructed a recombinant virus containing a nonsense mutation located 22 codons into the coding sequence of the NV protein. The NV knockout virus was produced at a concentration as high as that of wild-type virus in cultured fish cells, and the resulting virions appeared to be identical to the wild-type virions in electron micrographs. These initial studies suggest that NV has no critical function in SHRV replication in cultured fish cells.

Mx mRNA expression and RFLP analysis of rainbow trout Oncorhynchus mykiss genetic crosses selected for susceptibility or resistance to IHNV

Three interferon-inducible Mx genes have been identified in rainbow trout Oncorhynchus mykiss and their roles in virus resistance have yet to be determined. In mice, expression of the Mx1 protein is associated with resistance to influenza virus. We report a study to determine whether there was a correlation between the expression of Mx in rainbow trout and resistance to a fish rhabdovirus, infectious hematopoietic necrosis virus (IHNV). A comparison of Mx mRNA expression was made between different families of cultured rainbow trout selected for resistance or for susceptibility to IHNV. A trout-specific Mx cDNA gene probe was used to determine whether there was a correlation between Mx mRNA expression and resistance to the lethal effects of IHNV infection. Approximately 99% of trout injected with a highly virulent strain of the fish rhabdovirus, IHNV, were able to express full length Mx mRNA at 48 h post infection. This is markedly different from the expression of truncated, non-functional Mx mRNA found in most laboratory strains of mice, and the ability of only 25% of wild mice to express functional Mx protein. A restriction fragment length polymorphism (RFLP) assay was developed to compare the Mx locus between individual fish and between rainbow trout genetic crosses bred for IHNV resistance or susceptibility. The assay was able to discriminate 7 distinct RFLP patterns in the rainbow trout crosses. One cross was identified that showed a correlation between homozygosity at the Mx locus and greater susceptibility to IHN-caused mortality.

Reduced glutathione oxidation ratio and 8 ohdG accumulation by mild ischemic pretreatment

A critical role of oxidative stress has been implicated in ischemic brain damage. Mild ischemic pretreatment and/or synthesis of heat shock proteins (HSPs) has been suggested to protect against oxidative brain damage. However, experimental support of this suggestion have proven to be difficult partly because sensitive indices to assess oxidative consequences of ischemic brain damage were few. In this study, we have attempted to establish biochemical assay systems to quantitate oxidative brain damage following ischemia. We produced experimental brain ischemia in the Mongolian gerbil (Meriones unguiculatus) and examined the hippocampus for ischemic brain damage. The results obtained from ischemic gerbil hippocampus demonstrated that oxidative brain damage can be quantitated by determining glutathione oxidation ratio together with the accumulation of the oxidative DNA damage product, 8-hydroxy-2'-deoxyguanosine (8 ohdG). Our results also demonstrated a role for mild ischemic pretreatment and synthesis of HSPs against oxidative brain damage. We showed that mild 2-min ischemic pretreatment reduced the degree of both glutathione oxidation ratio and 8 ohdG accumulation in gerbil hippocampus subsequent to 10 min ischemic challenge. We also showed that the accumulation of HSP70 was closely associated with the reduction of oxidative brain damage. To our knowledge, this is the first report to investigate glutathione redox states and oxidative DNA damage levels to evaluate a protective role of mild ischemic pretreatment and HSP synthesis following brain ischemia. Our data validate the previous suggestions and provide new additional data that argue for the protective role of mild ischemic pretreatment and HSP70 synthesis against oxidative brain damage.

Expression of cyclooxygenase-1 and -2 in rheumatoid arthritis synovium

The aim of this study was to investigate the expression and localization of cyclooxygenase-1 and -2 (COX-1 and COX-2) in synovial tissues from patients with rheumatoid arthritis (RA). Synovial tissues from 9 patients with RA and 5 patients with osteoarthritis (OA) were examined for COX-1 and COX-2 expressions by immunohistochemical staining using 2 polydonal COX-1 and COX-2 antibodies. In RA synovia, synovial lining cells showed intense immunostaining for COX-1, whereas slight to moderate staining was observed in inflammatory cells, stromal fibroblast-like cells and vascular endothelial cells. There was no significant difference in COX-1 expression between RA and OA synovia. The localization of COX-2 expression dearly differed from that of COX-1 expression, being most intense in inflammatory cells. However, there was no difference in COX-1 and COX-2 expressions between RA and OA synovial tissues. Our observations support that inflammatory mechanisms modulated by COX-1 and COX-2 in chronic RA synovium might be similar to those in chronic OA synovium.