Catalytic growth and characterization of gallium nitride nanowires

The preparation of high-purity and -quality gallium nitride nanowires is accomplished by a catalytic growth using gallium and ammonium. A series of catalysts and different reaction parameters were applied to systematically optimize and control the vapor-liquid-solid (VLS) growth of the nanowires. The resulting nanowires show predominantly wurtzite phase; they were up to several micrometers in length, typically with diameters of 10-50 nm. A minimum nanowire diameter of 6 nm has been achieved. Temperature dependence of photoluminescence spectra of the nanowires revealed that the emission mainly comes from wurtzite GaN with little contribution from the cubic phase. Moreover, the thermal quenching of photoluminescence was much reduced in the GaN nanowires. The Raman spectra showed five first-order phonon modes. The frequencies of these peaks were close to those of the bulk GaN, but the modes were significantly broadened, which is indicative of the phonon confinement effects associated with the nanoscale dimensions of the system. Additional Raman modes, not observed in the bulk GaN, were found in the nanowires. The field emission study showing notable emission current with low turn-on field suggests potential of the GaN nanowires in field emission applications. This work opens a wide route toward detailed studies of the fundamental properties and potential applications of semiconductor nanowires.

An intronic NF-kappaB element is essential for induction of the human manganese superoxide dismutase gene by tumor necrosis factor-alpha and interleukin-1beta

Tumor necrosis factor-alpha (TNF) and interleukin-1beta (IL-1) are cytokines that induce expression of various genes through activation of the redox-sensitive transcription factor nuclear factor-kappaB (NF-kappaB). We have previously cloned the entire human MnSOD (SOD2) gene and found several NF-kappaB-binding sites in the 5' and 3' flanking and intronic regions. To test whether these putative NF-kappaB-binding sites are able to respond to TNF and IL-1, we performed induction analysis using various deletion constructs ligated to a luciferase reporter gene. We found that the 5' and 3' flanking regions containing several NF-kappaB-binding sites do not mediate MnSOD induction by TNF or IL-1. When a 342-bp intron 2 fragment containing NF-kappaB, C/EBP, and NF-1 binding sites was linked to the basal promoter of the SOD2 gene, transcriptional activities were significantly increased in response to TNF and IL-1 in an orientation- and position-independent manner. To accurately identify the element that is most critical for the enhancer activity, deletions and specific mutations of each individual site were studied. The results indicated that the NF-kappaB binding site is essential but not sufficient for TNF- or IL-1-mediated induction. Furthermore, NF-kappaB elements in the 5' and 3' flanking regions could be made to function in TNF or IL-1 induction when they were transposed to the intronic fragment. Taken together, these results suggest that an NF-kappaB element and its location in the SOD2 gene is critical for TNF/IL-1-mediated induction. However, a complex interaction between NF-kappaB and other transcription elements is needed for a high-level induction.

Comparison of the effects of thoracic epidural analgesia and i.v. infusion with lidocaine on cytokine response, postoperative pain and bowel function in patients undergoing colonic surgery

BACKGROUND

Both thoracic epidural analgesia (TEA) and i.v. lidocaine were able to decrease postoperative pain and duration of ileus. We compared TEA and i.v. lidocaine (IV) regarding their effects on cytokines, pain and bowel function after colonic surgery.

METHODS

Sixty patients were randomly allocated to one of the three groups. TEA group had lidocaine 2 mg kg(-1) followed by 3 mg kg(-1) h(-1) epidurally and an equal volume of i.v. normal saline. The IV group received the same amount of lidocaine i.v. and normal saline epidurally. The control group received normal saline via both routes. These regimens were started 30 min before surgery and were continued throughout. Blood cytokines were measured at scheduled times within 72 h.

RESULTS

Both TEA and IV groups had better pain relief. The total consumptions using patient-controlled epidural analgesia were 81.6 (6.5), 55.0 (5.3) and 45.6 (3.9) ml (P<0.01) and the times of flatus passage were 50.2 (4.9), 60.2 (5.8) and 71.7 (4.7) h (P<0.01) in the TEA, IV and control groups, respectively. The TEA group exhibited the best postoperative pain relief and the least cytokine surge. The IV group experienced better pain relief and less cytokine release than the control group.

CONCLUSIONS

The TEA lidocaine had better pain relief, lower opioid consumption, earlier return of bowel function and lesser production of cytokines than IV lidocaine during 72 h after colonic surgery; IV group was better than the control group.

Marine algal natural products with anti-oxidative, anti-inflammatory, and anti-cancer properties

For their various bioactivities, biomaterials derived from marine algae are important ingredients in many products, such as cosmetics and drugs for treating cancer and other diseases. This mini-review comprehensively compares the bioactivities and biological functions of biomaterials from red, green, brown, and blue-green algae. The anti-oxidative effects and bioactivities of several different crude extracts of algae have been evaluated both in vitro and in vivo. Natural products derived from marine algae protect cells by modulating the effects of oxidative stress. Because oxidative stress plays important roles in inflammatory reactions and in carcinogenesis, marine algal natural products have potential for use in anti-cancer and anti-inflammatory drugs.

Adenovirus-mediated p14(ARF) gene transfer in human mesothelioma cells

BACKGROUND

The p14(ARF) protein encoded by the INK4a/ARF locus promotes degradation of the MDM2 protein and thus prevents the MDM2-mediated inhibition of p53. Homozygous deletion of the INK4a/ARF locus is common in human mesothelioma and may result in the loss of p14(ARF) and the inactivation of p53. We designed this study to evaluate the biologic and potential therapeutic roles of p14(ARF) expression in mesothelioma cells.

METHODS AND RESULTS

We constructed Adp14, an adenoviral vector carrying human p14(ARF) complementary DNA, and used it to transfect human mesothelioma cell lines H28, H513, H2052, and MSTO-211H. Overexpression of p14(ARF) led to increased amounts of p53 and the p21(WAF) proteins and dephosphorylation of the retinoblastoma protein. The growth rate of mesothelioma cells was inhibited markedly by infection with Adp14 compared with mock infection or infection with a control adenovirus vector, AdCtrl. Overexpression of p14(ARF) induced G(1)-phase cell cycle arrest and apoptotic cell death. Cytotoxicity assays showed that Adp14 had a statistically significantly (P =.002) greater effect on colon cancer (HCT116) cell lines containing two copies of the wild-type p53 gene than on p53-null cells, suggesting that functional p53 is a critical determinant of p14(ARF)-mediated cytotoxicity.

CONCLUSIONS

The transfection of p14(ARF) into mesothelioma cells led to the overexpression of p14(ARF), which resulted in G(1)-phase arrest and apoptotic cell death. These results suggest that this gene therapy-based approach may be of use in the treatment of mesothelioma.

Mutations in the promoter reveal a cause for the reduced expression of the human manganese superoxide dismutase gene in cancer cells

Manganese superoxide dismutase (MnSOD) has been shown to play an important role in preventing the development of cancer. MnSOD activity is reduced in many transformed cells and tumor tissues. We previously showed that the reduced level of MnSOD activity in cancer cells was not due to a defect in the primary structure of MnSOD protein, but rather was due to defects in gene expression. To elucidate the cause for the reduced expression of human MnSOD in cancer, we investigated the nucleotide sequence in the regulatory region of the MnSOD gene in a normal human cell line and various human tumor cell lines. A DNA fragment spanning 3.4 kb 5' flanking region of the MnSOD gene isolated from a normal human genomic DNA library was used to determine the DNA sequence of MnSOD promoter. PCR primers were used for amplification of the 3.4 kb 5' flanking region of the human MnSOD gene in cancer cells. Sequence analysis identified three heterozygous mutations in the proximal region of the promoter in five human tumor cell lines. These mutations, clustered around the GC-rich region of the human MnSOD promoter, change the binding pattern of AP-2 and lead to a reduction in transcription activity using a luciferase reporter assay system. These results suggest that the reduced level of MnSOD expression in some tumor cells is, at least in part, due to a defect in the DNA sequence of the promoter region.

Oxidative stress and antioxidant status in mouse liver: effects of dietary lipid, vitamin E and iron

The purpose of this study was to determine the effects of dietary fat, vitamin E and iron on oxidative damage and antioxidant status. Male Swiss-Webster mice (1 mo old) were fed a basal vitamin E-deficient diet that contained either 8% fish oil + 2% corn oil or 10% lard with or without 1 g dl-alpha-tocopheryl acetate. The diets without vitamin E contained either 0.21 or 0.95 g ferric citrate/kg. Diets were fed for 4 wk/kg diet. Compared with the vitamin E-supplemented groups, mice fed diets without vitamin E (with or without supplemental iron) had significantly (P < 0.05) higher hepatic levels of thiobarbituric acid-reactive substances (TBARS), conjugated dienes and protein carbonyls when they were fed fish oil, but not lard. The levels of TBARS were further increased by iron supplementation in the mice fed fish oil. Significantly lower concentrations of alpha-tocopherol and higher glutathione (GSH) were found in the liver of mice fed fish oil and vitamin E than in those fed lard and vitamin E (P < 0.05). The activities of superoxide dismutase and glucose-6-phosphate dehydrogenase were lower in the fish oil-fed mice than in those fed lard (P < 0.05). The activities of Se-GSH peroxidase, non-Se-GSH peroxidase, catalase, and glutathione reductase were not altered by dietary fat or vitamin E/iron. The results obtained provide experimental evidence of the prooxidative effects of high dietary fish oil and iron, and suggest that vitamin E protects not only lipid-soluble compounds, but also water-soluble constituents, against oxidative damage. Further, dietary lipid plays a key role in determining cellular susceptibility to oxidative stress.

Cloning and characterization of human estrogen receptor beta promoter

Estrogen receptors beta (ERbeta) belong to the nuclear receptor superfamily of ligand-dependent transcription factors that play critical roles in regulating genes involved in a wide array of biological processes. To investigate regulation of tissue-specific expression of ERbeta, we cloned and characterized a 2.1-kilobase 5'-flanking region of the human ERbeta gene. Two major transcription start sites were identified by primer extension and rapid amplification of 5'-cDNA end. The human ERbeta proximal promoter contains both TATA box and initiator element (Inr) and is GC-rich with a GC content of 65%. An Alu repeat sequence containing an ER-dependent transcription enhancer exists between -1416 and -1703. The full-length 5'-flanking sequence of ERbeta fused to a luciferase reporter exhibited functional promoter activity in ERbeta-positive TSUPr1 cell, but not in ERbeta-negative DU145 cells. In addition, DNase I protection assays of the proximal promoter showed unique protection patterns with nuclear extracts from TSUPr1 cells and ERbeta negative HeLa cells, suggesting presence of cell-specific trans-acting factors that mediate tissue/cell-specific ERbeta expression. Serial deletion analysis revealed that a 293-bp region encompassing the TATA box and Inr element possesses basal promoter activity.

Anti-proliferative effect of methanolic extract of Gracilaria tenuistipitata on oral cancer cells involves apoptosis, DNA damage, and oxidative stress

Background

Methanolic extracts of Gracilaria tenuistipitata (MEGT) were obtained from the edible red algae. Previously, we found that water extract of G. tenuistipitata was able to modulate oxidative stress-induced DNA damage and its related cellular responses.

Methods

In this study, the methanol extraction product MEGT was used to evaluate the cell growth inhibition in oral cancer cells and its possible mechanism was investigated.

Results

The cell viability of MEGT treated Ca9-22 oral cancer cell line was significantly decreased in a dose–response manner (p < 0.05). The sub-G1 population and annexin V intensity of MEGT-treated Ca9-22 cancer cells were significantly increased in a dose–response manner (p < 0.0005 and p < 0.001, respectively). The γH2AX intensities of MEGT-treated Ca9-22 cancer cells were significantly increased in a dose–response manner (p < 0.05). The reactive oxygen species (ROS) and glutathione (GSH)-positive intensities of MEGT-treated Ca9-22 oral cancer cells were significantly increased and decreased, respectively, in a dose–response manner (p < 0.05). The DiOC₂(3) intensity for mitochondrial membrane potential (MMP) of MEGT-treated Ca9-22 cancer cells was significantly decreased in a dose–response manner (p < 0.05).

Conclusions

These results indicated that MEGT had apoptosis-based cytotoxicity against oral cancer cells through the DNA damage, ROS induction, and mitochondrial depolarization. Therefore, MEGT derived from the edible algae may have potential therapeutic effects against oral squamous cell carcinoma (OSCC).

Antiproliferation and induction of apoptosis in Ca9-22 oral cancer cells by ethanolic extract of Gracilaria tenuistipitata

The water extract of Gracilaria tenuistipitata have been found to be protective against oxidative stress-induced cellular DNA damage, but the biological function of the ethanolic extracts of G. tenuistipitata (EEGT) is still unknown. In this study, the effect of EEGT on oral squamous cell cancer (OSCC) Ca9-22 cell line was examined in terms of the cell proliferation and oxidative stress responses. The cell viability of EEGT-treated OSCC cells was significantly reduced in a dose-response manner (p < 0.0001). The annexin V intensity and pan-caspase activity of EEGT-treated OSCC cells were significantly increased in a dose-response manner (p < 0.05 to 0.0001). EEGT significantly increased the reactive oxygen species (ROS) level (p < 0.0001) and decreased the glutathione (GSH) level (p < 0.01) in a dose-response manner. The mitochondrial membrane potential (MMP) of EEGT-treated OSCC cells was significantly decreased in a dose-response manner (p < 0.005). In conclusion, we have demonstrated that EEGT induced the growth inhibition and apoptosis of OSCC cells, which was accompanied by ROS increase, GSH depletion, caspase activation, and mitochondrial depolarization. Therefore, EEGT may have potent antitumor effect against oral cancer cells.

The Chinese medicine Bu-Zhong-Yi-Qi-Tang inhibited proliferation of hepatoma cell lines by inducing apoptosis via G0/G1 arrest

Bu-Zhong-Yi-Qi-Tang (BZYQT), a Chinese herbal medicine, inhibited the proliferation of human hepatoma cell lines (Hep3B, HepG2 and HA22T) dose-dependently. The IC50s of BZYQT on the proliferation of Hep3B, HepG2 and HA22T were 432.5+/-31.8 microg/ml, 455.4+/-24.2 microg/ml, and 2284.3+/-77.2 microg/ml respectively on day 3. However, BZYQT did not significantly inhibit the proliferation of normal human hepatocytes (Chang liver, CCL-13) at the concentration under 5,000 microg/ml. Major compounds of BZYQT, including astragaloside IV, ginsenoside Rb1 and Rg1, saikosaponin a and c, and glycyrrhizin, have been identified. To investigate the key inhibitors of BZYQT. Hep3B cells were treated with BZYQT, individual major compounds of BZYQT, and mixture of major compounds in the same ratio as present in BZYQT. Significant inhibition of proliferation was detected in BZYQT and its major compounds mixture in a comparable level. Not any individual major compound examined could suppress the proliferation of Hep3B cells. This data indicated that there could be synergistic or additive effects of the ingredients in BZYQT. BrdU incorporation, cell cycle analysis and DNA fragmentation assay revealed that BZYQT suppressed the proliferation of hepatoma cells via G0/G1 cell cycle arrest and inhibition of DNA synthesis followed by apoptosis.

Pre-incisional epidural ketamine, morphine and bupivacaine combined with epidural and general anaesthesia provides pre-emptive analgesia for upper abdominal surgery

BACKGROUND

Previous studies have shown that N-methyl-D-asparate (NMDA) receptor antagonists provide a pre-emptive analgesic effect in humans. This study investigated the benefits of pre-emptive analgesia for upper abdominal surgery, using pre-incisional epidural ketamine + morphine + bupivacaine (K+M+B) treatment for achieving postoperative pain relief.

METHODS

Sixty ASA 1-2 patients scheduled for upper abdominal surgery were allocated to three groups in a randomized, single-blinded study. Patients in the control group (I) received general anaesthesia followed by an infusion of normal saline. Group II and III patients received general anaesthesia with a continuous epidural infusion of 2% lidocaine. Thirty minutes after the incision in groups I and II, an epidural pain control regimen was administered using ketamine (10 mg) and morphine (1 mg) in 10 ml of 0.085% bupivacaine (K+M+B). Group III patients also received K+M+B, but it was administered 10 min after the 2% lidocaine injection and 30 min before skin incision. All patients received an epidural pain control regimen (q12 h) for 3 days after their first injection. Patient-controlled analgesia (PCA) with morphine was used to control subsequent postoperative pain. During the 3-day period following surgery, duration to PCA trigger (h), morphine consumption (mg), pain intensity at rest and when coughing/moving, and analgesic-related adverse effects were recorded. The VAS scale (0-10) was used to assess pain intensity.

RESULTS

Median times to first PCA trigger were 1.2 (0.5-2.0) h, 3.0 (0.7-4.2) h, and 4.0 (2.5-7.5) h for groups I, II, and III, respectively. Both the incident and resting pain scores were consistently lower for group III patients than groups I and II. The number of PCA triggers (all attempts/successful triggers) during the day following surgery were 14.0 (3-30)/8.0 (3-24) times, 10.0 (3-23)/6.0 (2-20) times, and 7.0 (3-12)/4.5 (1-10) times for groups I, II, and III. Total morphine consumption for the 3-day observation period was 12.5 (3-42) mg, 10.5 (2-29) mg, and 6.0 (1-20) for groups I, II, and III, respectively.

CONCLUSION

Pre-incisional epidural K+M+B treatment combined with continuous epidural anaesthesia and general anaesthesia provides an ideal pre-emptive analgesic therapy, exhibiting better postoperative pain relief than general anaesthesia and post-incisional K+M+B treatment.

Antiproliferative effects of goniothalamin on Ca9-22 oral cancer cells through apoptosis, DNA damage and ROS induction

Goniothalamin (GTN), a plant bioactive styryl-lactone, is a natural product with potent anti-tumorigenesis effects for several types of cancer. Nonetheless, the anticancer effect of GTN has not been examined in oral cancer. The present study was designed to evaluate its potential anticancer effects in an oral squamous cell carcinoma (OSCC) model and to determine the possible mechanisms with respect to apoptosis, DNA damage, reactive oxygen species (ROS) induction, and mitochondrial membrane potential. Our data demonstrated that cell proliferation was significantly inhibited by GTN in Ca9-22 OSCC cancer cells in concentration- and time-dependent manners (p<0.05). For cell cycle and apoptotic effects of GTN-treated Ca9-22 cancer cells, the sub-G1 population and annexin V-intensity significantly increased in a concentration-dependent manner (p<0.001). For the analysis of DNA double strand breaks, γH2AX intensity significantly increased in GTN-treated Ca9-22 cancer cells in concentration-response relationship (p<0.05). Moreover, GTN significantly induced intracellular ROS levels in Ca9-22 cancer cells in a concentration- and time-dependent manner (p<0.05). For membrane depolarization of mitochondria, the DiOC(2)(3) (3,3'-diethyloxacarbocyanine iodide) intensity of GTN-treated Ca9-22 cancer cells was significantly decreased in concentration- and time-dependent relationships (p<0.001). Taken together, these results suggest that the anticancer effect of GTN against oral cancer cells is valid and GTN-induced growth inhibition and apoptosis influence the downstream cascade including ROS induction, DNA damage, and mitochondria membrane depolarization. Therefore, GTN has potential as a chemotherapeutic agent against oral cancer.

Comparative tracking error analysis of five different optical tracking systems

OBJECTIVE

Effective utilization of an optical tracking system for image-based surgical guidance requires optimal placement of the dynamic reference frame (DRF) with respect to the tracking camera. Unlike other studies that measure the overall accuracy of a particular navigation system, this study investigates the precision of one component of the navigation system: the optical tracking system (OTS). The precision of OTS measurements is quantified as jitter. By measuring jitter, one can better understand how system inaccuracies depend on the position of the DRF with respect to the camera.

MATERIALS AND METHODS

Both FlashPointtrade mark (Image Guided Technologies, Inc., Boulder, Colorado) and Polaristrade mark (Northern Digital Inc., Ontario, Canada) optical tracking systems were tested in five different camera and DRF configurations. A linear testing apparatus with a software interface was designed to facilitate data collection. Jitter measurements were collected over a single quadrant within the camera viewing volume, as symmetry was assumed about the horizontal and vertical axes.

RESULTS

Excluding the highest 5% of jitter, the FlashPoint cameras had an RMS jitter range of 0.028 +/- 0.012 mm for the 300 mm model, 0.051 +/- 0.038 mm for the 580 mm model, and 0.059 +/- 0.047 mm for the 1 m model. The Polaris camera had an RMS jitter range of 0.058 +/- 0.037 mm with an active DRF and 0.115 +/- 0.075 mm with a passive DRF.

CONCLUSION

Both FlashPoint and Polaris have jitter less than 0.11 mm, although the error distributions differ significantly. Total jitter for all systems is dominated by the component measured in the axis directed away from the camera.

Effects of garlic compounds diallyl sulfide and diallyl disulfide on arylamine N-acetyltransferase activity in strains of Helicobacter pylori from peptic ulcer patients

Arylamine N-acctyltransferase (NAT) activities with p-aminobenzoic acid (PABA) and 2-aminofluorene (2-AF) were determined in the bacterium Helicobacter pylori collected from peptic ulcer patients. Two assay systems were performed, one with cellular cytosols, the other with intact cell suspensions. Cytosols or suspensions of H. pylori with or without specific concentrations of diallyl sulfide (DAS) or diallyl disulfide (DADS) co-treatment showed different percentages of 2-AF and PABA acetylation. The data indicated that there was decreased NAT activity associated with increased levels of DAS or DADS in H. pylori cytosols and suspensions. Viability studies on H. pylori demonstrated that DAS or DADS elicited dose-dependent bactericide affects on H. pylori cultures. The data also indicated that DAS and DADS decreased the apparent values of K(m) and Vmax of NAT enzyme from H. pylori in both systems examined. This report is the first demonstration that garlic components can affect H. pylori growth and NAT activity.

DNA mismatch repair enzyme activity and gene expression in prostate cancer

Microsatellite instability (MSI) of short repetitive sequences in human chromosomal DNA can result from defective DNA mismatch repair function in tumor cells. We hypothesize that DNA mismatch repair (MMR) activity is down-regulated during prostatic carcinogenesis. To test this hypothesis, MMR activities and mismatch repair-related genes were analyzed in five different prostate cancer cell lines. Our results demonstrate that MMR activities were decreased as compared to MMR proficient HeLa cells. Interestingly, LNCaP, PC-3 and DU145 had much lower MMR activities as compared to DUPro and TSUPr1. The MMR-related genes (hMLH1, hPMS1, hPMS2, hMSH2, hMSH3, hMSH6) showed mRNA transcripts in all prostate cancer cell lines. However, Western blotting showed decreased or absent hMLH1 protein expression in PC-3, DU145, DUPro and TSUPr1 cells. Similarly, the hMSH2 protein expression was low or absent in DU145 and LNCaP cells. This is the first report that demonstrates decreased MMR activities is associated with low expression of hMLH1, hMSH2 and other MMR-related proteins in prostate cancer.

Pro-inflammatory cytokine-stimulated first trimester decidual cells enhance macrophage-induced apoptosis of extravillous trophoblasts

OBJECTIVE

As human blastocyst-derived extravillous trophoblasts (EVTs) invade the early decidua, they are positioned to interact with immune cells and resident decidual cells, and remodel spiral arteries into high capacity vessels that increase blood flow to the developing fetal-placental unit. Shallow EVT invasion elicits incomplete vascular transformation and reduces uteroplacental blood flow that presages adverse pregnancy outcomes. Excess macrophages in the decidua induce EVT apoptosis via tumor necrosis factor-alpha (TNF-α) secretion. Our previous observation that pro-inflammatory cytokines enhance neutrophil and macrophage activator granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in first trimester decidual cells is now extended to include: (1) the specific macrophage activator M-CSF; (2) macrophage activation and subsequent enhancement of EVT apoptosis by both GM-CSF and M-CSF.

STUDY DESIGN

Quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay assessed M-CSF expression in first trimester decidual cells incubated with interleukin-1 beta (IL-1β) or TNF-α. Peripheral monocyte-derived macrophages pre-incubated with conditioned media from decidual cell cultures were co-cultured with a first trimester EVT cell line, HTR-8/SVneo cells. Macrophage activation was examined and EVT apoptosis evaluated by DNA fragmentation, caspase activation and cell membrane asymmetry.

RESULTS

IL-1β or TNF-α significantly enhanced M-CSF expression in first trimester decidual cells. The conditioned media from these cultures activates macrophages, which promote caspase 3/7-dependent EVT apoptosis with antibodies against GM-CSF or M-CSF blocking this effect.

CONCLUSIONS

Pro-inflammatory cytokines increases synthesis of M-CSF in first trimester decidual cells. Both GM-CSF and M-CSF activate macrophages, which initiate caspase-dependent EVT apoptosis.

Transcriptional regulation of the 5' proximal promoter of the human manganese superoxide dismutase gene

Manganese superoxide dismutase (MnSOD) is a primary antioxidant enzyme critical for maintaining normal cell function and for survival. Previously, we cloned the entire MnSOD gene, including a 0.782-kb 5' DNA sequence, from a human embryonic lung fibroblast cell line. Sequence analysis indicates that the promoter of the human MnSOD gene is TATA-less and CAAT-less, and the DNA sequence immediately upstream from the transcription start site is GC rich. To study the function and regulation of the human MnSOD promoter, we cloned a 257-bp sequence (P7) containing the transcription start site and the 5' GC-rich region. Consensus analysis and DNase I footprinting assay indicated that P7 contains multiple Sp1- and AP-2-binding sites. Deletions of the P7 sequence diminished the promoter activity and decreased the response to Sp1 protein. The first three Sp1 consensus sites were required for high promoter activity in mammalian cells and enhanced promoter activity in Drosophila Schneider Line 2 (SL2) cells. In the SL2 cells, Sp1 activated the P7 activity in a dose-dependent manner. In contrast, cotransfections with AP-2 expression vector marginally increased P7 activities in human hepatocarcinoma HepG2 cells. The results suggest that Sp1 is an important regulator for the transcriptional activities of P7, whereas AP-2 is a minor activator for P7 and competes with Sp1 for binding sites which may downregulate P7 function.

Aqueous extract of Gracilaria tenuistipitata suppresses LPS-induced NF-κB and MAPK activation in RAW 264.7 and rat peritoneal macrophages and exerts hepatoprotective effects on carbon tetrachloride-treated rat

In addition to the previous investigations of bioactivity of aqueous extract of the edible Gracilaria tenuistipitata (AEGT) against H2O2-induced DNA damage and hepatitis C virus replication, the purpose of this study is to evaluate the potential therapeutic properties of AEGT against inflammation and hepatotoxicity using lipopolysaccharide (LPS)-stimulated mouse RAW 264.7 cells, primary rat peritoneal macrophages and carbon tetrachloride (CCl4)-induced acute hepatitis model in rats. AEGT concentration-dependently inhibited the elevated RNA and protein levels of inducible nitric oxide synthase and cyclooxygenase-2, thereby reducing nitric oxide and prostaglandin E2 levels, respectively. Moreover, AEGT significantly suppressed the production of LPS-induced proinflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α. These inhibitory effects were associated with the suppression of nuclear factor-kappa B activation and mitogen-activated protein kinase phosphorylation by AEGT in LPS-stimulated cells. In addition, we highlighted the hepatoprotective and curative effects of AEGT in a rat model of CCl4-intoxicated acute liver injury, which was evident from reduction in the elevated serum aspartate aminotransferase and alanine aminotransferase levels as well as amelioration of histological damage by pre-treatment or post-treatment of AEGT. In conclusion, the results demonstrate that AEGT may serve as a potential supplement in the prevention or amelioration of inflammatory diseases.

Inhibition of N-acetyltransferase activity and DNA-2-aminofluorene adducts by glycyrrhizic acid in human colon tumour cells

Glycyrrhizic acid (GA) was tested for inhibition of arylamine N-acetyltransferase (NAT) activity in a human colon tumour (adenocarcinoma) cell line (colo 205). Two assay systems were performed, one with cellular cytosols (9000g supernatant), the other with intact colon tumour cell cultures. The NAT activity in a human colon tumour cell line was inhibited by GA in a dose-dependent manner in both types of systems examined. The data also indicated that GA decreased the apparent values of K(m) and V(max) of NAT enzymes from human colon tumour cells in both examined systems. The DNA-2-aminofluorene adduct formation in human colon tumour cells were inhibited by GA. This report is the first to demonstrate that GA does inhibit human colon tumour cell NAT activity and DNA adduct formation.

Berberine inhibited arylamine N-acetyltransferase activity and gene expression and DNA adduct formation in human malignant astrocytoma (G9T/VGH) and brain glioblastoma multiforms (GBM 8401) cells

Studies have demonstrated that berberine exhibits the antineoplastic action in rat model. Rat glial tumor cells also have been shown to have N-acetyltransferase activity. In this study, we reported the effects of berberine on arylamine N-acetyltransferase (NAT) activity, gene expression, and DNA adduct formation in human brain tumor cell lines (G95/VGH and GBM 8401). The activity of NAT (N-acetylation of substrate) was measured and determined by high-performance liquid chromatography (HPLC) assaying for the amounts of acetylated 2-aminofluorene (AF) and nonacetylated AF. Human brain tumor cells (G9T/VGH and GBM 8401) were used for examining NAT activity and gene expression and AF-DNA adduct formation. NAT gene expression was determined by polymerase chain reaction (PCR) for the levels of mRNA NAT in both examined cells lines. The amounts of AF-DNA adducts were also determined and quantities by HPLC. The results demonstrated that NAT activity, levels of mRNA NAT1 and AF-DNA adduct formation in both examined cell were inhibited and decreased by berberine in a dose-dependent manner. The apparent values of Km and Vmax from NAT of both examined cells were also determined with or without berberine cotreatment. The data also indicated that berberine decreased the apparent values of Km and Vmax. These effects also indicate that berberine is a uncompetitive inhibitor.

Discovery and epidemiology of PCB poisoning in Taiwan: a four-year followup

An outbreak of polychlorinated biphenyl (PCB) poisoning from the consumption of contaminated rice oil, covering four counties in central Taiwan, was investigated. There were 1843 cases by the end of 1980. The highest frequency of incidence occurred during the period from March to July 1979. The severity of clinical manifestations varied. Most patients showed symptoms of mild or moderate severity. The major age group affected was between 11 and 20 years old. Most of the victims were students and factory workers. The amount of PCB intake in each victim was estimated to be 0.7 to 1.84 g and the latent period from the time of intake to the onset of clinical manifestations was approximately 3 to 4 months. The patients' blood PCB concentrations ranged from 3 ppb to 1156 ppb; 44.27% of 613 patients had levels of 51 to 100 ppb and 27.6% PCB blood levels over 100 ppb. In the course of 3.5 years, 2061 persons were determined to be PCB poisoning victims. Now, except for a few severe cases, their skin symptoms are very much improved. Thirty-nine babies showing hyperpigmentation were born from PCB-poisoned mothers. The fatality rate was high: eight of them died. Another 24 deaths were reported among the PCB-poisoned group, almost half of them (12) from hepatoma, liver cirrhosis or liver diseases with hepatomegaly.

Preincisional dextromethorphan decreases postoperative pain and opioid requirement after modified radical mastectomy

PURPOSE

To examine whether preincisional dextromethorphan (DM) improved analgesia after modified radical mastectomy (MRM).

METHODS

Sixty patients (ASA I-II) scheduled for MRM were included and randomly allocated into two groups. Patients in the treatment group (DM) received 40 mg DM and 20 mg chlorpheniramine maleate (CPM) i.m., and those in the control group received 20 mg CPM i.m. alone 30 min before skin incision. Meperidine, 1 mg x kg(-1) i.m., was given for postoperative pain relief as required. The time to first meperidine injection, total meperidine consumption, worst pain score, bed-rest time, and side effects were recorded every 24 hr for 48 hr after surgery by a resident anesthesiologist on a double-blind basis.

RESULTS

A longer time to first meperidine injection (19.2 +/- 1.6 vs 1.5 +/- 0.23 hr, P < 0.001) and lower meperidine consumption (0[10] vs 75[50] mg, median [interquartile range], P < 0.001) were observed in the DM group than in the control group. The bed-rest time was shorter in the DM than in the control group (18.0[4] vs 23.0[19] hr, P < 0.001). No difference was noted in worst VAS pain score. Meperidine-related side effects (nausea, vomiting, pruritus, dizziness, headache) were more frequent in the control (10/30) than in the DM group (3/30, P < 0.05). The number of patients who required meperidine injection for pain relief was lower in the DM (7/30) than in the control group (25/30, P < 0.005). No DM- or CPM-associated side effects were observed.

CONCLUSION

Preincisional IM. DM treatment decreased postoperative pain and opioid requirement after MRM surgery.

Upregulation of L-plastin gene by testosterone in breast and prostate cancer cells: identification of three cooperative androgen receptor-binding sequences

L-Plastin is normally a leukocyte-specific actin-binding protein; it is also expressed in the majority of human cancer cell lines that are derived from many types of solid tumors. We have previously reported the isolation of the L-plastin gene promoter, in which we identified several potential steroid receptor-binding sequences. We now obtained evidence that L-plastin gene expression was positively regulated by testosterone in androgen receptor (AR)-positive prostate and breast cancer cells. DNase I footprint analysis identified three AR-binding elements (ARE) located in a 545-bp region approximately 1.1 kb upstream from the transcription initiation site. However, each of these three AREs exhibited very little testosterone/AR-responsive enhancer activities toward a test promoter (of the thymidine kinase gene) when tested in MCF-7 breast cancer cells. Their testosterone/AR responsiveness became evident only when two or three of them were combined. In PC-3 prostate cancer cells, cooperation among L-plastin AREs was still evident although individually they had moderate levels of testosterone/AR responsiveness. Thus, the three L-plastin AREs, despite their imperfect sequences compared with the consensus ARE, could cooperate with each other to become a potent testosterone/AR-responsive unit, which was likely responsible for the inducibility of the L-plastin gene by testosterone.

Aqueous extract of the edible Gracilaria tenuistipitata inhibits hepatitis C viral replication via cyclooxygenase-2 suppression and reduces virus-induced inflammation

Hepatitis C virus (HCV) is an important human pathogen leading to hepatocellular carcinoma. Using an in vitro cell-based HCV replicon and JFH-1 infection system, we demonstrated that an aqueous extract of the seaweed Gracilaria tenuistipitata (AEGT) concentration-dependently inhibited HCV replication at nontoxic concentrations. AEGT synergistically enhanced interferon-α (IFN-α) anti-HCV activity in a combination treatment. We found that AEGT also significantly suppressed virus-induced cyclooxygenase-2 (COX-2) expression at promoter transactivation and protein levels. Notably, addition of exogenous COX-2 expression in AEGT-treated HCV replicon cells gradually abolished AEGT anti-HCV activity, suggesting that COX-2 down-regulation was responsible for AEGT antiviral effects. Furthermore, we highlighted the inhibitory effect of AEGT in HCV-induced pro-inflammatory gene expression such as the expression of tumour necrosis factor-α, interleukin-1β, inducible nitrite oxide synthase and COX-2 in a concentration-dependent manner to evaluate the potential therapeutic supplement in the management of patients with chronic HCV infections.