Endovascular treatment of intracranial vertebral artery dissections with stent placement or stent-assisted coiling

BACKGROUND AND PURPOSE

Endovascular treatment with stent placement or stent-assisted coiling was recently introduced as an alternative to parent artery occlusion in intracranial vertebral artery dissections. We describe the efficacy and limitations of this method.

METHODS

Fourteen patients with intracranial vertebral artery dissection were treated with stent placement (10 patients) or stent-assisted coiling (4 patients). Double overlapping stents were deployed in 4 of 10 patients with stent placement alone. Angiographic follow-up at 6 to 12 months was available in 13 patients.

RESULTS

In 13 patients with dissecting aneurysm, immediate angiographic outcomes were complete occlusion (1 patient), nearly complete (2 patients), and incomplete (10 patients). Follow-up angiograms of 12 of these patients showed complete occlusion (6 patients) and incomplete (6 patients; 1 unstable and 5 stable). Complete occlusion rates in follow-up angiograms were superior in double stent placement (75%) or stent-assisted Guglielmi detachable coil (GDC) embolization to stent placement alone (0%). There were no instances of postprocedural ischemic attacks, new neurologic deficits, and no new minor or major strokes before patient discharge. On the modified Rankin scale applied in follow-up, all patients were assessed as functionally improved or of stable clinical status.

CONCLUSIONS

Intracranial vertebral artery dissections were acceptably treated with stent placement or stent-assisted coiling, and the patency could be preserved at follow-up. However, the efficiency of stent placement alone for intracranial vertebral artery dissecting aneurysm was limited. Stent-assisted coil embolization or double stent placements are a viable alternative for complete occlusion of dissecting aneurysms.

CDC7 kinase phosphorylates serine residues adjacent to acidic amino acids in the minichromosome maintenance 2 protein

Cdc7 is an essential kinase required for the initiation of eukaryotic DNA replication. Previous studies in many species showed that the minichromosome maintenance complex is a major physiological target of this kinase. In this study, we have mapped the sites in human Mcm2 protein that are phosphorylated by Cdc7. The in vitro phosphorylation of several Mcm2 truncated proteins and peptides revealed that Mcm2 contains two major ((5)S and (53)S) and at least three minor phosphorylation sites ((4)S, (7)S, and (59)T) located at the N-terminal region. Alanine substitution experiments with Mcm2 peptides showed that the phosphorylation of (5)S and (53)S by Cdc7 required the presence of an acidic amino acid adjacent to a serine residue. Furthermore, although Cdc7 was unable to phosphorylate a Mcm2 peptide (spanning amino acids 19-30 and containing (26)S and (27)S), it phosphorylated (26)S efficiently when this peptide contained a chemically synthesized phospho-(27)S modification. Hence, additional Cdc7 phosphorylation sites could be generated in Mcm2 by its prior phosphorylation by a cyclin-dependent kinase. This finding may explain why the sequential action of cyclin-dependent and Cdc7 kinases is essential for the initiation of DNA replication.

Search for new physics in lepton+photon+X events with 305 pb(-1) of pp collisions at [square root of s] = 1.96 TeV

We present results of a search for anomalous production of events containing a charged lepton (l, either e or mu) and a photon (gamma), both with high transverse momentum, accompanied by additional signatures X, including missing transverse energy (ET) and additional leptons and photons. We use the same selection criteria as in a previous CDF search but with a substantially larger data set, 305 pb(-1), a pp collision energy of 1.96 TeV, and the CDF II detector. We find 42 lgammaET events versus an expectation of 37.3+/-5.4 events. We observe 31 llgamma+X events versus an expectation of 23.0+/-2.7 events. We find no events similar to the run I eegammagammaET event.

Measurement of the Bc+ meson lifetime using the decay mode Bc+ --> J/Psie+nue

We present a measurement of the Bc+ meson lifetime in the decay mode Bc+ --> J/Psie+nue using the Collider Detector at Fermilab II detector at the Fermilab Tevatron Collider. From a sample of about of 360 pb(-1) of pp collisions at square root of s = 1.96 TeV, we reconstruct J/Psie+ pairs with invariant mass in the kinematically allowed range 4< M(J/Psie) < 6 GeV/c2. A fit to the decay-length distribution of 238 signal events yields a measured Bc+ meson lifetime of 0.463(-0.065)(+0.073)(stat) +/- 0.036(syst) ps.

Cell cycle regulatory protein expression profiles by adenovirus p53 infection in human papilloma virus-associated cervical cancer cells

PURPOSE

The tumor suppressor gene, p53, has been established as an essential component for the suppression of tumor cell growth. In this study, we investigated the time-course anticancer effects of adenoviral p53 (Adp53) infection on human ovarian cancer cells to provide insight into the molecular-level understanding of the growth suppression mechanisms involved in Adp53-mediated apoptosis and cell cycle arrest.

MATERIALS AND METHODS

Three human cervical cancer cell lines (SiHa, CaSki, HeLa and HT3) were used. The effect of Adp53 infection was studied via cell count assay, cell cycle analysis, FACS, Western blot and macroarray assay.

RESULTS

Adp53 exerts a significant role in suppressing cervical cancer cell growth. Adp53 also showed growth inhibitory effects in each cell line, and it induced apoptosis and cell cycle arrest. Adp53 differentially regulated the expression of genes and proteins, and the gene expression profiles in the SiHa cells revealed that the p21, p53 and mdm2 expressions were significantly up-regulated at 24 and 48 hr. Western blot shows that the p21 and p53 expression-levels were significantly increased after Adp53 infection. In addition, in all cell lines, both the CDK4 and PCNA protein expression levels were decreased 48 h after Adp53 infection. Cell cycle arrest at the G1 phase was induced only in the SiHa and HeLa cells, suggesting that exogenous infection of Adp53 in cancer cells was significantly different from the other HPV-associated cervical cancer cells.

CONCLUSION

Adp53 can inhibit cervical cancer cell growth through induction of apoptosis and cell cycle arrest, as well as through the regulation of the cell cycle-related proteins. The Adp53-mediated apoptosis can be employed as an advanced strategy for developing preferential tumor cell-specific delivery.

Observation of B(0)(s)-->Psi(2S)Phi and measurement of the ratio of branching fractions Beta(B(0)(s)-->Psi(2S)Phi)/Beta(B(0)(s)-->J/PsiPhi)

We report the first observation of B(0)(s)-->Psi(2S)Phi decay in p(p_) collisions at square root of 8=1.96 TeV using 360 pb(-1) of data collected by the CDF II detector at the Fermilab Tevatron. We observe 20.2 +/- 5.0 and 12.3 +/- 4.1 B(0)(s)-->Psi(2S)Phi candidates, in Psi(2S)-->mu(+)mu(-) and Phi(2S)-->J/Phipi(+)pi(-) decay modes, respectively. We present a measurement of the relative branching fraction Beta(B(0)(s)-->Psi(2S)Phi)/Beta(B(0)(s)-->J/PsiPhi)=0.52 +/- 0.13(stat) +/- 0.04(syst) +/- 0.06(BR) using the Psi(2S)-->mu(+)mu(-) decay mode.

Search for Z' --> e+ e- using dielectron mass and angular distribution

We search for Z' bosons in dielectron events produced in pp collisions at square root of s = 1.96 TeV, using 0.45 fb(-1) of data accumulated with the Collider Detector at Fermilab II detector at the Fermilab Tevatron. To identify the Z' --> e+ e- signal, both the dielectron invariant mass distribution and the angular distribution of the electron pair are used. No evidence of a signal is found, and 95% confidence level lower limits are set on the Z' mass for several models. Limits are also placed on the mass and gauge coupling of a generic Z', as well as on the contact-interaction mass scales for different helicity structure scenarios.

Search for high-mass resonances decaying to emu in pp collisions at square root = 1.69 TeV

We describe a general search for resonances decaying to a neutral emu final state in pp collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing 344 pb(-1) of integrated luminosity recorded by the Collider Detector at Fermilab II experiment, we compare standard model predictions with the number of observed events for invariant masses between 50 and 800 GeV/c2. Finding no significant excess (5 events observed vs 7.7 +/- 0.8 expected for M(emu) > 100 GeV/c2 ), we set limits on sneutrino and Z' masses as functions of lepton family number violating couplings.

Analysis of colonoscopic findings in the differential diagnosis between intestinal tuberculosis and Crohn's disease

BACKGROUND AND STUDY AIMS

Intestinal tuberculosis and Crohn's disease are chronic inflammatory bowel disorders that are difficult to differentiate from one another. This study aimed to evaluate the diagnostic value of various colonoscopic findings in the differential diagnosis between intestinal tuberculosis and Crohn's disease.

PATIENTS AND METHODS

Colonoscopic findings on initial work-up were prospectively recorded in patients with an initial diagnosis of either intestinal tuberculosis or Crohn's disease. These findings were analyzed after a final diagnosis of intestinal tuberculosis (n = 44) or Crohn's disease (n = 44) had been made after follow-up.

RESULTS

Four parameters (anorectal lesions, longitudinal ulcers, aphthous ulcers, and cobblestone appearance) were significantly more common in patients with Crohn's disease than in patients with intestinal tuberculosis. Four other parameters (involvement of fewer than four segments, a patulous ileocecal valve, transverse ulcers, and scars or pseudopolyps) were observed more frequently in patients with intestinal tuberculosis than in patients with Crohn's disease. We hypothesized that a diagnosis of Crohn's disease could be made when the number of parameters characteristic of Crohn's disease was higher than the number of parameters characteristic of intestinal tuberculosis, and vice versa. Making these assumptions, we calculated that the diagnosis of either intestinal tuberculosis or Crohn's disease would have been made made correctly in 77 of our 88 patients (87.5 %), incorrectly in seven patients (8.0 %), and would not have been made in four patients (4.5 %).

CONCLUSIONS

A systematic analysis of colonoscopic findings is very useful in the differential diagnosis between intestinal tuberculosis and Crohn's disease.

Lessons learned from 1,000 living donor liver transplantations in a single center: how to make living donations safe

Serious complications have occurred in a considerable proportion of living donors of liver transplants, but data from a single high-volume center has rarely been available. We analyzed the medical records of donors and recipients of the first 1,000 living donor liver transplants, performed at Asan Medical Center from December 1994 to June 2005, with a focus on donor safety. There were 107 pediatric and 893 adult transplants. The most common diagnoses were biliary atresia in pediatric recipients (63%) and hepatitis B-associated liver cirrhosis (80%) in adult recipients. Right lobe donors were strictly selected based on liver resection rate and steatosis. From 1,162 living donors, 588 right lobes, 6 extended right lobes, 7 right posterior segments, 464 left lobes, and 107 left lateral segments were obtained. Of these, 837 grafts were implanted singly, whereas 325, along with 1 cadaveric split graft, were implanted as dual grafts into 163 recipients. The 5-yr survival rates were 84.8% in pediatric recipients and 83.2% in adult recipients. There was no donor mortality, but 3.2% of donors experienced major complications. Until the end of 2001, the major donor complication rate was 6.7%, with most occurring in right liver donors. Since 2002, liver resection exceeding 65% of whole liver volume were avoided except for young donors with no hepatic steatosis, and the donor complication rate has been reduced to 1.3%. In conclusion, a majority of major living donor complications appear to be avoidable through the strict selection of living donor and graft type, intensive postoperative surveillance, and timely feedback of surgical techniques. Selection of right lobe graft should be very prudently considered if the donor right liver appears to be larger than 65% of the whole liver volume.

Long-term incidence, risk factors, and management of biliary complications after adult living donor liver transplantation

A considerable proportion of adult living donor liver transplantation (LDLT) recipients experience biliary complication (BC), but there are few reports regarding BC based on long-term studies of a large LDLT population. The present study examined BC incidence, risk factors and management using single-center data from 259 adult patients (225 right liver and 34 left liver grafts) between 2000 and 2002. The mean follow-up period was 46 +/- 14 months. Biliary reconstruction included single duct-to-duct anastomosis (DD, n = 141), double DD (n = 19), single hepaticojejunostomy (HJ, n = 67), double HJ (n = 28), and combined DD and HJ (n = 4). There were 12 episodes of anastomotic bile leak and 42 episodes of anastomotic stenosis in 50 recipients. Most leaks occurred within the first month, whereas stenosis occurred over 3 yr. Most stenoses were successfully treated using radiological intervention. Cumulative 1-, 3-, and 5-yr BC rates were 12.9%, 18.2%, and 20.2%, respectively. BC occurred much more frequently in right liver grafts compared to left liver grafts (P = 0.024). Stenosis-free survival curves for right liver graft recipients were similar for all reconstruction groups. When right liver graft recipients with single biliary reconstructions were grouped according to graft duct size and type of biliary reconstruction, DD involving a small-sized duct (less than 4 mm in diameter) was found to be a BC risk factor (P = 0.015), whereas HJ involving such duct sizes was not found to be associated with a higher risk (P = 0.471). In conclusion, close surveillance for BC appears necessary for at least the first 3 yr after LDLT. We found that most BC could be successfully controlled using radiological intervention. In terms of anastomotic stenosis risk, HJ appears a better choice than DD for right liver grafts involving ducts less than 4 mm in diameter.

Protein expression profile using two-dimensional gel analysis in squamous cervical cancer patients

PURPOSE

Screening in cervical cancer is now progressing to discover candidate genes and proteins that may serve as biological markers and that play a role in tumor progression. We examined the protein expression patterns of the squamous cell carcinoma (SCC) tissues from Korean women with using two- dimensional polyacrylamide gel electrophoresis (2-DE) and matrix assisted laser desorption/ionization-time of flight (MALDI- TOF) mass spectrometer.

MATERIALS AND METHODS

Normal cervix and SCC tissues were solubilized and 2-DE was performed using pH 3 approximately 10 linear IPG strips of 17 cm length. The protein expression was evaluated using PDQuest 2-D software. The differentially expressed protein spots were identified with a MALDI-TOF mass spectrometer, and the peptide mass spectra identifications were performed using the Mascot program and by searching the Swiss-prot or NCBInr databases.

RESULTS

A total of 35 proteins were detected in SCC. 17 proteins were up-regulated and 18 proteins were down-regulated. Among the proteins that were identified, 12 proteins (pigment epithelium derived factor, annexin A2 and A5, keratin 19 and 20, heat shock protein 27, smooth muscle protein 22 alpha, alpha-enolase, squamous cell carcinoma antigen 1 and 2, glutathione S-transferase and apolipoprotein a1) were protein previously known to be involved in tumor, and 21 proteins were newly identified in this study.

CONCLUSION

2-DE offers the total protein expression profiles of SCC tissues; further characterization of these differentially expressed proteins will give a chance to identify the badly needed tumor-specific diagnostic markers for SCC.

Protective effect of agmatine on a reperfusion model after transient cerebral ischemia: Temporal evolution on perfusion MR imaging and histopathologic findings

BACKGROUND AND PURPOSE

The goal of thrombolytic therapy in patients with acute ischemic stroke is early recanalization, but this may result in delayed reperfusion injury. The purpose of this study was to evaluate the neuroprotective effect of agmatine in a transient ischemic cat model by using MR perfusion imaging and histopathologic analyses.

METHOD

One-hour temporary occlusion of the left middle cerebral artery of cats was performed in the control ischemia group (n = 10), and 100 mg/kg of agmatine was intravenously injected immediately after recanalization in the agmatine-treated group (n = 15). MR imaging was performed at 1, 24, and 48 hours after recanalization, and the perfusion patterns were investigated. Terminal-deoxynucleotidyl transferase mediated nick and end-labeling (TUNEL) and hematoxylin-eosin (H&E) stainings were performed at the corresponding sections.

RESULTS

In the control ischemia group, the number of TUNEL-positive cells was significantly increased in the areas with reperfusion hyperemia (P < .05). In the agmatine-treated group, no significant increase in the number of TUNEL-positive cells was noted in the areas of reperfusion hyperemia. The difference in the number of TUNEL-positive cells between the control ischemia and agmatine-treated group in the areas of reperfusion hyperemia was significant (P < .05). The total number of TUNEL-positive cells and the area of severe ischemic neuronal damage on H&E stain were also significantly attenuated in the agmatine-treated cats compared with the control ischemia cats (P < .05).

CONCLUSION

Our results suggest that agmatine has neuroprotective effects against reperfusion injury and ischemia.

Tissue-specific regulation of malonyl-CoA decarboxylase activity in OLETF rats

AIM

The intracellular concentration of malonyl-CoA, a key regulator of fatty acid oxidation, is determined both from its synthesis by acetyl-CoA carboxylase and from its degradation by malonyl-CoA decarboxylase (MCD). The aim of our study was to investigate the activity and mRNA expression of MCD under insulin resistance and after treatment with insulin sensitizers in different tissues.

METHODS

We treated 18-week Otusuka Long-Evans Tokushima Fatty (OLETF) rats with pioglitazone (10 mg/kg/day) or metformin (300 mg/kg/day) for 8 weeks and determined the activity and mRNA expression of MCD in diabetic OLETF and non-diabetic Long-Evans Tokushima Otsuka (LETO) rats in myocardial and skeletal muscles, and in liver.

RESULTS

The MCD activities of myocardial and skeletal muscles were remarkably reduced in OLETF rats compared with LETO rats (995 +/- 114 vs. 2012 +/- 359, 58 +/- 11 vs. 167 +/- 40 pmol/min/mg protein; p = 0.005 and p = 0.010). Surprisingly, after pioglitazone treatment, not after metformin, the MCD activities of myocardial and skeletal muscles (1906 +/- 320 and 259 +/- 44 pmol/min/mg protein) increased up to the levels in LETO rats. MCD mRNA expression in OLETF rats was also reduced in myocardial and skeletal muscles vs. LETO rats (p = 0.049 and p = 0.008) and was unchanged by pioglitazone or metformin treatment. In the liver, MCD activity and mRNA expression were similar in OLETF and LETO rats.

CONCLUSION

Pioglitazone treatment restored MCD activity to non-diabetic level and improved the restrained fatty acid metabolism in myocardial and skeletal muscles caused by insulin-resistant diabetic status.

Molecular cloning and characterization of bovine PRKAG3 gene: structure, expression and single nucleotide polymorphism detection

The protein kinase adenosine monophosphate-activated gamma3-subunit (PRKAG3) gene encodes a muscle-specific isoform of the regulatory gamma-subunit of adenosine monophosphate-activated protein kinase, which plays a key role in regulating energy homeostasis in eucaryotes. It is well known that mutations in the PRKAG3 gene affect high glycogen content in the porcine skeletal muscle and, consequently, meat quality. The genomic structure and sequence of the bovine PRKAG3 were analysed from a Korean cattle BAC clone. The bovine PRKAG3 gene comprises 13 exons and spans approximately 6.8 kb on BTA2. From 5' and 3'-rapid amplification of cDNA ends experiments, the full-length cDNA of bovine PRKAG3 has been identified, encoding a deduced protein of 465 amino acids. Two splice isoforms, generated by the alternative splicing of exon 2, were also identified. Northern blot analysis demonstrated that, similar to other species, the bovine PRKAG3 transcript was only expressed in skeletal muscle. Seven single nucleotide polymorphisms, including two previously identified variants, were detected in four Bos taurus cattle breeds. The bovine PRKAG3 gene described in this study may be involved in muscle-related genetic diseases or meat quality traits in cattle.

Inhibitory effects of ginsenoside-Rb1 on activation of the 12-O-tetradecanoylphorbol 13-acetate-induced cyclooxygenase-2 promoter

We studied the inhibitory effects of ginsenoside-Rb1 (1) on 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced transcriptional activation of the cyclooxygenase-2 (COX-2) promoter. The suppressive activity of ginsenoside-Rb1 was characterized using COX-2 promoter-driven luciferase reporter plasmids in a transient transfection system. Ginsenoside-Rb1 at 100 microM inhibited TPA-induced transcriptional activation of the COX-2 promoter. To identify the cis-acting elements responsible for this inhibition, the effects of site-specific mutations in the COX-2 promoter region were examined. Inhibition by ginsenoside-Rb1 was not affected by mutations in nuclear factor-kappaB- or cAMP-responsive elements. However, the effects were abolished when the nuclear factor-interleukin-6 binding site was mutated, indicating that ginsenoside-Rb1 exerts its effects via this element. In conclusion, ginsenoside-Rb1 inhibits TPA-induced COX-2 promoter activity through the nuclear factor interleukin-6 binding site and not through the nuclear factor-kappaB or cAMP-responsive elements.

Precision top-quark mass measurement in the lepton+jets topology in p p collisions at square root s=1.96 TeV

We report two measurements of the top-quark mass M(top) using the CDF II detector at the Fermilab Tevatron in a 318 pb(-1) data sample of tt events in the lepton+jets final state. One method uses an event-based likelihood technique resulting in M(top) = 173.2(-2.4)(+2.6)(stat) +/- 3.2(syst) GeV/c2 or 173.2(-4.0)(+4.1) GeV/c2. The second method reconstructs a top-quark mass in each event using the measured invariant mass of the hadronically decaying W boson to constrain the jet energy scale to obtain a value for M(top)of 173.5(-3.6)(+3.7)(stat) +/- 1.3(syst) GeV/c2 or 173.5(-3.8)(+3.9) GeV/c2 . We take the latter, which is more precise, as our result.

In vivo organ mass of Korean adults obtained from whole-body magnetic resonance data

In vivo organ mass of the Korean adult, male and female were presented for the purpose of radiation protection. A total of 121 healthy volunteers (66 males and 55 females), whose body dimensions were close to that of average Korean adults, were recruited for this study. Whole-body magnetic resonance (MR) images were obtained, and contours of 15 organs (brain, eye, gall bladder, heart, kidney, liver, lung, pancreas, stomach, spleen, testes, thymus, thyroid, urinary bladder and uterus) and 9 bones (femur, tibia + fibula, humerus, radius + ulna, pelvis, cervical spine, thoracic and lumber spine, skull and clavicle) were segmented for organ volume rendering by anatomists using commercial software. Organ and bone masses were calculated by multiplying the Asian reference densities of the corresponding organs and bones by the measured volumes. The resulting organ and bone masses were compared with those of the International Commission of Radiological Protection (ICRP) and the Asian reference data. Significantly large standard deviation was shown in the moving organs of the respiratory and circulatory systems and in the alimentary and urogenital organs that are variable in volume in a single person. Gall bladder and pancreas showed unique Korean organ masses compared with those of ICRP and the Asian reference adults. Different from anatomical data based on autopsy, the in vivo volume and mass in this study can more exactly describe the organ volume of a living human subject for radiation protection. A larger sample size would be required for obtaining statistically more reliable results. It is also needed to establish the reference organ mass of younger age groups for which it is difficult to recruit volunteers and to immobilise the subjects for long-time MR scanning. At present, the data from this study will contribute to the establishment of a Korean reference database.

In Vivo Evaluation of P-glycoprotein Function at the Blood-Brain Barrier in Nonhuman Primates Using [11C]Verapamil

P-glycoprotein (P-gp) is a major efflux transporter contributing to the efflux of a range of xenobiotic compounds at the blood-brain barrier (BBB). In the present study, we evaluated the P-gp function at the BBB using positron emission tomography (PET) in nonhuman primates. Serial brain PET scans were obtained in three rhesus monkeys after intravenous administration of [(11)C]verapamil under control and P-gp inhibition conditions ([PSC833 ([3'-keto-Me-Bmt(1)]-[Val(2)]-cyclosporin) 20 mg/kg/2 h]). The parent [(11)C]verapamil and its metabolites in plasma were determined by HPLC with a positron detector. The initial brain uptake clearance calculated from the integration plot was used for the quantitative analysis. After intravenous administration, [(11)C]verapamil was taken up rapidly into the brain (time to reach the peak, 0.58 min). The blood level of [(11)C]verapamil decreased rapidly, and it underwent metabolism with time. The inhibition of P-gp by PSC833 increased the brain uptake of [(11)C]verapamil 4.61-fold (0.141 versus 0.651 ml/g brain/min, p < 0.05). These results suggest that PET measurement with [(11)C]verapamil can be used for the evaluation of P-gp function at the BBB in the living brain.

Tetraarsenic oxide-mediated apoptosis in a cervical cancer cell line, SiHa

PURPOSE

Diarsenic oxide, As(2)O(3), has been reported to be effective in treating acute leukemia, and induce apoptosis in many tumor cells. In this study, the ability of a novel arsenical compound, As(4)O(6) (tetraarsenic oxide), along with As(2)O(3), for its ability to induce cell growth inhibition, as well as apoptosis, in human cervical cancer cells, SiHa cells, were evaluated in vitro.

MATERIALS AND METHODS

To examine the levels of apoptosis, SiHa cells were given two sensitive doses, 0.5 and 1 microM, of arsenical compounds, and a DNA fragmentation assay and FACS analysis were then conducted. In addition, a Western blotting assay was performed to identify target molecules for apoptosis.

RESULTS

Both As(2)O(3) and As(4)O(6) induced dosedependent inhibition of SiHa cell proliferation. In particular, As(4)O(6) was more effective at suppressing SiHa cell growth than As(2)O(3). In parallel with the inhibition of cell proliferation, As(4)O(6) caused a significantly greater increase in the sub-G1 cell population than As(2)O(3), as determined by propidium iodide DNA staining. This was confirmed by a DNA fragmentation assay and annexin V staining. The Western blotting analysis also showed that the expression of proliferating cell nuclear antigen (PCNA) was suppressed to a significantly greater extent by As(4)O(6) than As(2)O(3) at a dose of 0.5 microM. However, the apoptosis-related protein, Bax, was expressed to a significantly greater extent due to As(4)O(6) than As(2)O(3).

CONCLUSION

Taken together, these findings suggest that a novel arsenic compound, As(4)O(6), possesses more potent anti-proliferative effects on human cervical cancer cells, with the induction of apoptosis also, at least via the activation of Bax protein in vitro.

Homopairing Possibilities of the DNA Bases Cytosine and Guanine: An ab Initio DFT Study

All the planar homopairings of cytosine and guanine are reported for the first time in this study. The idea of binding sites suggested for the simple case of adenine homopairs (J. Phys. Chem. B 2005, 109, 11933) is shown to be applicable to more complicated molecules binding to each other via multiple hydrogen bonds and can be considered as a general method for constructing hydrogen bonding structures. As an example we consider homopairs formed by DNA bases cytosine and guanine, suggesting that there may be 13 cytosine and 17 guanine homopairs. However, only 11 cytosine and 15 guanine homopairs remain after atomic relaxation performed using ab initio density functional theory. Most of the homopairs obtained have not been studied before. The homopairs have significant binding energies, varying from -0.19 to -1.12 eV, that are explained by multiple hydrogen bonds formed between monomers in the pairs, up to four hydrogen bonds in most energetically favorable cases. The detailed information on all guanine and cytosine planar homopairs contained in this work can be used to construct various cytosine and guanine superstructures observed on different surfaces.

Feasibility study of nitrogen removal with the mecellulose wasted liquor as an external carbon source in the two-stage denitrification process

The utilization of mecellulose wasted liquor (MWL) as an external carbon source was investigated to find an alternative for methanol in the two-stage denitrification pilot process. The pilot plant was supplied with the raw water from the J-Municipal Sewage Treatment Plant (J-MSTP) in Korea. The raw water of J-Municipal Sewage Treatment Plant contains low and high concentration of biodegradable organics and nitrogen source, respectively, due to the inflow of industrial wastewater and landfill leachate. Methanol was fed to provide external carbon source for high concentration of nitrogen source removal by denitrification in this J-Municipal Sewage Treatment Plant, and thus this study was performed to test effects to the effluent quality and efficiencies of nitrogen source removal with an alternative carbon source for the cost reduction. The 6.5mg 1(-1) and 5.7mg l(-1) of total nitrogen (TN) concentration in the effluent were achieved with mecellulose and methanol, whereas mecellulose and methanol were fed to give the same ratio of gCODgNO,-N(-1), respectively. The 60% of COD in mecellulose wasted liquor was used as a carbon source for denitrification and the stable denitrification rate was earned when one half of the required total carbon source for denitrification was fed to pre-anoxic tank in the pilot plant. The required gCODgNO,-N(-1) ratio with mecellulose wasted liquor was 1.4 times higher than with methanol. Mecellulose wasted liquor is feasible to be used as external carbon source for organic loading, nitrogen and phosphorus removal. If mecellulose wasted liquor is considered as an alternative external carbon source to substitute methanol 26-28m3 mecellulose wasted liquor per 1 m3 methanol will be required. However, to meet with the effluent standard (10 mg BOD l(-1)) for J-Municipal Sewage Treatment Plant, the feed concentration of mecellulose wasted liquor should be recommended to be lower than 200 mgl(-1).