ABSTRACT
Lavender essential oil (Lvn) has anti-inflammatory effects in an ovalbumin-sensitized murine model of asthma, and inhibits inflammatory cell infiltration into the lungs. The anti-inflammatory effects of Lvn on cell adhesion molecules are not clear. Here we evaluated the effects of Lvn and its main constituents, linalyl acetate (LA) and linalool (LO), on the expression of tumor necrosis factor-alpha (TNF-α)-induced cell adhesion molecules in murine brain endothelial bEnd.3 cells and human umbilical vein endothelial cells (HUVECs). The bEnd.3 cells were treated with Lvn, LA, or LO and subsequently stimulated with TNF-α. The mRNA expression levels of cell adhesion molecules were detected using RT-PCR. E-selectin and P-selectin protein and phosphorylated-NF-κB p65 were detected by western blotting. The effects of Lvn on HUVECs were measured by RT-PCR. In bEnd.3 cells, Lvn and LA suppressed TNF-α-induced E-selectin, P-selectin, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and phosphorylated-NF-κB p65 in the nucleus; LO did not suppress P-selectin or phosphorylated-NF-κB p65. Lvn inhibited TNF-α-induced E-selectin mRNA in HUVECs. These results indicate that Lvn and LA inhibit TNF-α-induced cell adhesion molecules in endothelial cells through the suppression of NF-κB activation. Consequently, Lvn or other essential oils including LA may be useful as alternative anti-inflammatory medicines.
Subject(s)
Cell Adhesion Molecules/analysis , Endothelial Cells/drug effects , Monoterpenes/pharmacology , Oils, Volatile/pharmacology , Plant Oils/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Acyclic Monoterpenes , Animals , Cell Adhesion Molecules/genetics , Endothelial Cells/chemistry , Endothelial Cells/metabolism , Human Umbilical Vein Endothelial Cells/chemistry , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/metabolism , Humans , Lavandula , Mice , NF-kappa B/physiology , Oils, Volatile/analysis , Plant Oils/analysis , Tumor Necrosis Factor-alpha/antagonists & inhibitorsABSTRACT
Aflatoxin (AFT) contamination is frequent in foods grown in tropical regions, including rice. Although AFTs are generally not found in temperate-region foods, global warming has affected typical temperate-region climates, potentially permitting the contamination of foods with AFT-producing Aspergillus flavus (A. flavus). Here we investigated the AFT production in rice during storage under natural climate conditions in Japan. We examined AFTs in brown rice and rough rice artificially contaminated with A. flavus for 1 year in Japan, and we subjected AFTs in white rice to the same treatment in airtight containers and examined the samples in warm and cold seasons, simulating the storage of white rice in general households. In the brown rice, AFTs increased after 2 months (March) and peaked after 9 months (October). The AFT contamination in the rough rice was minimal. After the polishing and cooking of the brown rice, AFTs were undetectable. In the white rice stored in airtight containers, AFTs increased after 1 month (August) and peaked after 2 months (September). Minimal AFTs were detected in the cold season. Thus, AFT contamination in rice may occur in temperate regions following A. flavus contamination. The storage of rice as rough rice could provide be useful for avoiding AFT contamination.
Subject(s)
Aflatoxins/chemistry , Aspergillus flavus/metabolism , Food Contamination , Food Storage , Oryza/chemistry , Aflatoxins/metabolism , Japan , Oryza/microbiologyABSTRACT
Dynasore, a specific dynamin GTPase inhibitor, suppresses lamellipodia formation and cancer cell invasion by destabilizing actin filaments. In search for novel dynamin inhibitors that suppress actin dynamics more efficiently, dynasore analogues were screened. N'-[4-(dipropylamino)benzylidene]-2-hydroxybenzohydrazide (DBHA) markedly reduced in vitro actin polymerization, and dose-dependently inhibited phosphatidylserine-stimulated dynamin GTPase activity. DBHA significantly suppressed both the recruitment of dynamin 2 to the leading edge in U2OS cells and ruffle formation in H1299 cells. Furthermore, DBHA suppressed both the migration and invasion of H1299 cells by approximately 70%. Furthermore, intratumoral DBHA delivery significantly repressed tumor growth. DBHA was much less cytotoxic than dynasore. These results strongly suggest that DBHA inhibits dynamin-dependent actin polymerization by altering the interactions between dynamin and lipid membranes. DBHA and its derivative may be potential candidates for potent anti-cancer drugs.
Subject(s)
Actins/antagonists & inhibitors , Actins/metabolism , Dynamins/metabolism , Hydrazones/administration & dosage , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Cell Line, Tumor , Cell Movement/drug effects , Dimerization , Dynamins/antagonists & inhibitors , Enzyme Activation/drug effects , Humans , Neoplasm InvasivenessABSTRACT
The human immunodeficiency virus type 1 (HIV-1) Vif plays a crucial role in the viral life cycle by antagonizing a host restriction factor APOBEC3G (A3G). Vif interacts with A3G and induces its polyubiquitination and subsequent degradation via the formation of active ubiquitin ligase (E3) complex with Cullin5-ElonginB/C. Although Vif itself is also ubiquitinated and degraded rapidly in infected cells, precise roles and mechanisms of Vif ubiquitination are largely unknown. Here we report that MDM2, known as an E3 ligase for p53, is a novel E3 ligase for Vif and induces polyubiquitination and degradation of Vif. We also show the mechanisms by which MDM2 only targets Vif, but not A3G that binds to Vif. MDM2 reduces cellular Vif levels and reversely increases A3G levels, because the interaction between MDM2 and Vif precludes A3G from binding to Vif. Furthermore, we demonstrate that MDM2 negatively regulates HIV-1 replication in non-permissive target cells through Vif degradation. These data suggest that MDM2 is a regulator of HIV-1 replication and might be a novel therapeutic target for anti-HIV-1 drug.
Subject(s)
HIV-1/physiology , Ubiquitin-Protein Ligases/metabolism , vif Gene Products, Human Immunodeficiency Virus/metabolism , APOBEC-3G Deaminase , Cell Line , Cytidine Deaminase/analysis , Cytosol/chemistry , Humans , Protein Binding , Virus ReplicationABSTRACT
Integrase (IN), an essential enzyme of human immunodeficiency virus (HIV), is an attractive antiretroviral drug target. The antiviral activity and resistance profile in vitro of a novel IN inhibitor, elvitegravir (EVG) (also known as JTK-303/GS-9137), currently being developed for the treatment of HIV-1 infection are described. EVG blocked the integration of HIV-1 cDNA through the inhibition of DNA strand transfer. EVG inhibited the replication of HIV-1, including various subtypes and multiple-drug-resistant clinical isolates, and HIV-2 strains with a 50% effective concentration in the subnanomolar to nanomolar range. EVG-resistant variants were selected in two independent inductions, and a total of 8 amino acid substitutions in the catalytic core domain of IN were observed. Among the observed IN mutations, T66I and E92Q substitutions mainly contributed to EVG resistance. These two primary resistance mutations are located in the active site, and other secondary mutations identified are proximal to these primary mutations. The EVG-selected IN mutations, some of which represent novel IN inhibitor resistance mutations, conferred reduced susceptibility to other IN inhibitors, suggesting that a common mechanism is involved in resistance and potential cross-resistance. The replication capacity of EVG-resistant variants was significantly reduced relative to both wild-type virus and other IN inhibitor-resistant variants selected by L-870,810. EVG and L-870,810 both inhibited the replication of murine leukemia virus and simian immunodeficiency virus, suggesting that IN inhibitors bind to a conformationally conserved region of various retroviral IN enzymes and are an ideal drug for a range of retroviral infections.
Subject(s)
Anti-HIV Agents/pharmacology , Drug Resistance, Viral/genetics , HIV-1/drug effects , HIV-2/drug effects , Integrase Inhibitors/pharmacology , Quinolones/pharmacology , Amino Acid Substitution/genetics , Binding Sites , Humans , Leukemia Virus, Murine/drug effects , Microbial Sensitivity Tests , Simian Immunodeficiency Virus/drug effects , Virus Replication/geneticsABSTRACT
Solid solutions with of Cu3 VS4 with either Cu3 NbS4 or Cu3 TaS4 (Cu3 Nb1-x Vx S4 or Cu3 Ta1-x Vx S4 ) were prepared by a solid-state reaction and adopted a sulvanite structure. Their band gaps were 1.6-1.7â eV corresponding to the absorption of a wide range of visible light. Ru cocatalyst-loaded Cu3 MS4 (M=V, Nb, Ta), Cu3 Nb1-x Vx S4 , and Cu3 Ta1-x Vx S4 showed photocatalytic activities for sacrificial H2 evolution under visible-light irradiation. Most solid solutions showed better activities than the single-component Cu3 MS4 (M=V, Nb, Ta). Cu3 MS4 (M=V, Nb), Cu3 Nb1-x Vx S4 , and Cu3 Ta1-x Vx S4 also functioned as photoelectrodes and gave cathodic photocurrents under visible-light irradiation, indicating a p-type semiconductor character. Cu3 Nb0.9 V0.1 S4 showed the best photocatalytic and photoelectrochemical performances. When Ru-loaded Cu3 Nb0.9 V0.1 S4 was used as a photocathode with a CoOx -loaded BiVO4 photoanode, photoelectrochemical water splitting proceeded under simulated sunlight irradiation without an external bias.
ABSTRACT
In search for effective human immunodeficiency virus type 1 (HIV-1) transcription inhibitors, we have evaluated more than 100,000 compounds for their inhibitory effects on HIV-1 long terminal repeat (LTR)-driven reporter gene expression, and identified a novel naphthalene derivative, JTK-101. This compound could suppress tumour necrosis factor (TNF)-alpha-induced HIV-1 production in latently infected OM-10.1 cells at nanomolar concentrations. JTK-101 could also potently inhibit constitutive HIV-1 production in MOTL-4/IIIB. However, the antiviral activity of JTK-101 was found to be much weaker in acutely infected cells and the chronically infected cells U937/IIIB cells than in OM-10.1 and MOLT-4/IIIB cells. JTK-101 selectively suppressed TNF-alpha-induced HIV-1 mRNA synthesis in OM-10.1 cells in a dose-dependent fashion. JTK-101 modestly inhibited TNF-alpha-induced HIV-1 LTR-driven reporter gene expression, but potently inhibited Tat-induced gene expression. Immunoblot analysis revealed that low-level expression of the Tat cofactors CDK9 and cyclin T1 might contribute to the diminished antiviral activity in U937/IIIB cells. Furthermore, JTK-101 could not inhibit HIV-1 replication in chronically infected monocytes/macrophages, in which CDK9 and cyclin T1 were undetectable. These results suggest that JTK-101 exerts its anti-HIV-1 activity through the inhibition of known or unknown Tat cofactors, presumably CDK9/cyclin T1.
Subject(s)
Anti-HIV Agents/chemistry , Anti-HIV Agents/pharmacology , Gene Products, tat/antagonists & inhibitors , HIV-1/drug effects , Naphthalenes/chemistry , Naphthalenes/pharmacology , Virus Replication/drug effects , Cell Line , Cyclin T , Cyclin-Dependent Kinase 9 , Cyclins , Fluoroquinolones/chemistry , Fluoroquinolones/pharmacology , Gene Expression Regulation, Viral , Gene Products, tat/metabolism , HIV-1/physiology , Humans , Molecular Structure , Transcriptional Activation , Tumor Necrosis Factor-alpha/pharmacologyABSTRACT
To clarify the efficacy and problems of postoperative adjuvant chemotherapy using oral fluoropyrimidines, the clinicopathological data of 307 colorectal cancer patients treated with or without postoperative chemotherapy were analyzed retrospectively. Patients in the chemotherapy group (n=188) who underwent curative resection were followed by administration of oral fluoropyrimidine. The other 119 patients underwent surgery alone. The disease-free survival rates were compared between the two groups. The disease-free survival rate in the chemotherapy group was significantly higher than that in the surgery alone. However, no significant difference in disease-free survival rate was found for those with tumors that were associated with mesenteric lymph node involvement and tumors with a high grade of lymphatic invasion or high grade of venous invasion. Postoperative adjuvant chemotherapy using oral fluoropyrimidines such as UFT (litegafur +4:uracil) and 5'-DFUR (doxifluridine) might not reduce the risk of recurrence in colorectal cancer with mesenteric lymph nodes involvement.
Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Colorectal Neoplasms/drug therapy , Floxuridine/administration & dosage , Neoplasm Recurrence, Local/prevention & control , Administration, Oral , Aged , Aged, 80 and over , Chemotherapy, Adjuvant , Colectomy , Colorectal Neoplasms/pathology , Colorectal Neoplasms/surgery , Disease-Free Survival , Female , Humans , Lymph Node Excision , Lymphatic Metastasis , Male , Mesentery , Middle Aged , Retrospective Studies , Tegafur/administration & dosage , Uracil/administration & dosageABSTRACT
Case: A 61-year-old man was diagnosed with severe chest trauma after a car accident and had had difficulty in weaning from a ventilator because of flail chest and dilated cardiomyopathy. On the 17th day in the intensive care unit, he received i.v. acetazolamide to increase urine output. One hour after the injection, he suddenly developed severe hypoxia. Chest radiography revealed a butterfly shadow. He received other diuretics and a vasodilator, which seemed slowly to resolve the respiratory failure. Five days later, acetazolamide was again given and he experienced the same deterioration. Outcome: We concluded that the episodes were attributed to pulmonary edema provoked by acetazolamide. Conclusion: Acute non-cardiogenic pulmonary edema is an uncommon and lethal adverse effect of acetazolamide. Careful attention may be warranted when administering acetazolamide to critically ill patients.
ABSTRACT
Following the discovery of a new series of benzimidazole derivatives bearing a diarylmethyl group as inhibitors of hepatitis C virus NS5B RNA-dependent RNA polymerase (HCV NS5B RdRp),1,2 we extended the structure-activity relationship (SAR) study to analogues bearing a substituted biphenyl group and succeeded in a significant advancement of activity. Starting from compound 1, optimization of the A, B, and C rings afforded potent inhibitors with low nanomolar potency against genotype 1b NS5B. The compounds, which have a substituent with a carbonyl function at the 4-position of the B-ring, efficiently blocked subgenomic viral RNA replication in the replicon cell assay at low submicromolar concentrations. Among the new compounds, compound 10n (JTK-109) exhibited favorable pharmacokinetic profiles, high selectivity for NS5B, and good safety profiles, suggesting the potential for a clinical candidate in the treatment of hepatitis C.
Subject(s)
Antiviral Agents/chemical synthesis , Benzimidazoles/chemical synthesis , Biphenyl Compounds/chemical synthesis , RNA-Dependent RNA Polymerase/antagonists & inhibitors , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Antiviral Agents/pharmacokinetics , Antiviral Agents/pharmacology , Benzimidazoles/pharmacokinetics , Benzimidazoles/pharmacology , Biphenyl Compounds/pharmacokinetics , Biphenyl Compounds/pharmacology , Cell Line , Cell Survival/drug effects , Hepacivirus/genetics , Humans , Liver/metabolism , Rats , Replicon , Structure-Activity Relationship , Viral Nonstructural Proteins/chemistryABSTRACT
The viral enzyme integrase is essential for the replication of human immunodeficiency virus type 1 (HIV-1) and represents a remaining target for antiretroviral drugs. Here, we describe the modification of a quinolone antibiotic to produce the novel integrase inhibitor JTK-303 (GS 9137) that blocks strand transfer by the viral enzyme. It shares the core structure of quinolone antibiotics, exhibits an IC50 of 7.2 nM in the strand transfer assay, and shows an EC50 of 0.9 nM in an acute HIV-1 infection assay.
Subject(s)
Anti-Bacterial Agents/chemical synthesis , HIV Integrase Inhibitors/chemical synthesis , HIV Integrase/metabolism , Quinolones/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Cell Line , DNA, Viral/chemistry , HIV Integrase Inhibitors/chemistry , HIV Integrase Inhibitors/pharmacology , HIV-1/drug effects , HIV-1/enzymology , Humans , Quinolones/chemistry , Quinolones/pharmacology , Structure-Activity RelationshipABSTRACT
We report a new series of hepatitis C virus NS5B RNA polymerase inhibitors containing a conformationally constrained tetracyclic scaffold. SAR studies led to the identification of 6,7-dihydro-5H-benzo[5,6][1,4]diazepino[7,1-a]indoles (19 and 20) bearing a basic pendent group with high biochemical and cellular potencies. These compounds displayed a very small shift in cellular potency when the replicon assay was performed in the presence of human serum albumin.
Subject(s)
Antiviral Agents/chemical synthesis , Benzodiazepines/chemical synthesis , Hepacivirus/enzymology , Heterocyclic Compounds, 4 or More Rings/chemical synthesis , Indoles/chemical synthesis , Viral Nonstructural Proteins/antagonists & inhibitors , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Benzodiazepines/chemistry , Benzodiazepines/pharmacology , Crystallography, X-Ray , Hepacivirus/genetics , Heterocyclic Compounds, 4 or More Rings/chemistry , Heterocyclic Compounds, 4 or More Rings/pharmacology , Humans , Indoles/chemistry , Indoles/pharmacology , Models, Molecular , Molecular Conformation , RNA, Viral/genetics , Replicon , Serum Albumin , Structure-Activity Relationship , Viral Nonstructural Proteins/chemistryABSTRACT
BACKGROUND: The aim of this study was to determine any correlation between the efficacy of postoperative adjuvant chemotherapy using oral fluoropyrimidines and the matrix metalloproteinase 9 (MMP-9) expression in primary colorectal cancer tissues. PATIENTS AND METHODS: The data on 307 patients with colorectal cancer at stage II or III, who underwent potentially curative resection with lymphadenectomy, were reviewed. Of these, 188 received postoperative administration of oral fluoropyrimidines such as UFT and 5'-DFUR (chemotherapy group), while the other 119 patients underwent surgery alone (surgery-alone group). Immunostaining for MMP-9 was performed using surgical specimens of all 307 primary tumors and 18 recurrent tumors. RESULTS: Overall, MMP-9 was positively expressed in the primary tumor in 44% of patients. Multivariate analysis revealed that the MMP-9 expression was a worse prognostic factor with a second highest hazard ratio for recurrence. The disease-free survival rate in the chemotherapy group was significantly higher than that in the surgery-alone group. However, no significant difference in disease-free survival rate between the two groups was found in patients with a tumor positive for MMP-9. There was a strong positive correlation of MMP-9 expression between the primary tumors and the recurrent liver or lung tumors. CONCLUSIONS: The efficacy of postoperative adjuvant chemotherapy using oral fluoropyrimidines such as UFT and 5'-DFUR may not be as great for patients with a tumor positive for MMP-9 having a greater risk to postoperative recurrence.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/drug therapy , Matrix Metalloproteinase 9/metabolism , Neoplasm Recurrence, Local/drug therapy , Administration, Oral , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Chemotherapy, Adjuvant , Colorectal Neoplasms/enzymology , Colorectal Neoplasms/surgery , Disease-Free Survival , Female , Floxuridine/administration & dosage , Humans , Liver Neoplasms/enzymology , Liver Neoplasms/secondary , Liver Neoplasms/therapy , Lung Neoplasms/enzymology , Lung Neoplasms/secondary , Lung Neoplasms/therapy , Lymph Node Excision , Lymphatic Metastasis/pathology , Male , Neoplasm Invasiveness/pathology , Neoplasm Recurrence, Local/enzymology , Neoplasm Recurrence, Local/surgery , Neoplasm Staging , Postoperative Period , Retrospective Studies , Survival Rate , Tegafur/administration & dosage , Uracil/administration & dosageABSTRACT
The aim of this study was to determine any correlation between the efficacy of post-operative adjuvant chemotherapy using oral fluoropyrimidines and the vascular endothelial growth factor (VEGF) expression in primary colorectal cancer tissues. The data were reviewed retrospectively on 342 patients with colorectal cancer at stage II or III, who underwent potentially curative resection between 1988 and 1998. Of these, 225 received post-operative administration of oral fluoropyrimidines such as UFT and 5'-DFUR, while the other 117 patients underwent surgery alone. Immunostaining for VEGF was performed using colorectal tumours. Overall, VEGF was positively expressed in primary tumour cells in 48% of patients. The disease-free survival rate and the overall survival rate in the chemotherapy group were higher than those in the surgery-alone group, although not significantly. However, the disease-free survival rate and the overall survival rate were similar between the two groups in patients with a tumour positive for VEGF. Multivariate analysis revealed that the VEGF expression was an independent factor for post-operative recurrence, and the VEGF expression and post-operative adjuvant chemotherapy were an independent factor for overall survival, in addition to the lymph node metastasis and the venous invasion. In conclusion, the efficacy of post-operative adjuvant chemotherapy using oral fluoropyrimidines may not be as great for patients with a tumour positive for VEGF having a greater risk of post-operative recurrence. The results support further investigation on efficacy of molecular targeting therapy for VEGF in combination with oral fluoropyrimidines as post-operative adjuvant therapy in colorectal cancer positive for VEGF.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/metabolism , Vascular Endothelial Growth Factor A/metabolism , Administration, Oral , Aged , Aged, 80 and over , Chemotherapy, Adjuvant , Colorectal Neoplasms/pathology , Combined Modality Therapy , Disease-Free Survival , Female , Floxuridine/administration & dosage , Humans , Male , Neoplasm Invasiveness , Neoplasm Recurrence, Local/therapy , Neoplasm Staging , Postoperative Period , Retrospective Studies , Survival Rate , Tegafur/administration & dosageABSTRACT
The water-soluble vitamin (included vitamin B1, B6, B12 and C) preparations are not always replenished when peripheral parenteral nutrition (PPN) is used in Japan. We evaluated the need for administration of vitamins preparation during PPN, and involved analysis of the blood levels of water-soluble vitamins in patients receiving perioperative PPN before and after gastrectomy. Patients were examined as two set of groups as follows; 18 patients who did not receive water-soluble vitamin preparations during PPN, the Unsupplemented Group, and 22 patients who received such preparations during PPN, the Supplemented Group. Consequently, in the Unsupplemented Group, the blood vitamin B1 level during the early postoperative period was significantly lower than the preoperative level, but in the Supplemented Group, it was significantly higher than the preoperative level. In the Supplemented Group, the blood vitamin B12 level during the early postoperative period was markedly higher than the preoperative level. And in both groups, the blood vitamin C level remained below the lower limit of the criterion range throughout the perioperative period. These results suggested that administration of water-soluble vitamins during PPN was needed to avoid potential vitamin deficiencies after surgery and to prevent a potential onset of severe metabolic complications from any deficiencies.
Subject(s)
Ascorbic Acid/blood , Parenteral Nutrition/methods , Thiamine/blood , Vitamin B 12/blood , Vitamin B 6/blood , Aged , Female , Humans , Male , Middle AgedABSTRACT
The authors present an approach for fabricating stable white light emission from polymer light-emitting electrochemical cells (PLECs) having an active layer which consists of blue-fluorescent poly(9,9-di-n-dodecylfluorenyl-2,7-diyl) (PFD) and π-conjugated triphenylamine molecules. This white light emission originates from exciplexes formed between PFD and amines in electronically excited states. A device containing PFD, 4,4',4''-tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA), Poly(ethylene oxide) and K2CF3SO3 showed white light emission with Commission internationale de l'éclairage (CIE) coordinates of (0.33, 0.43) and a Color Rendering Index (CRI) of Ra = 73 at an applied voltage of 3.5 V. Constant voltage measurements showed that the CIE coordinates of (0.27, 0.37), Ra of 67, and the emission color observed immediately after application of a voltage of 5 V were nearly unchanged and stable after 300 sec.
Subject(s)
Electrochemical Techniques , Color , Light , PolymersABSTRACT
We have previously determined the crystal structure of a non-structural 5B (NS5B) protein, an RNA-dependent RNA polymerase (RdRp) of hepatitis C virus (HCV). NS5B protein with the hydrophobic C-terminal 21 amino acid residues truncated, designated NS5B(570), shows a typical nucleotide polymerase structure resembling a right-hand shape. In the crystal structure, a C-terminal region between Leu545 and His562 occupies a putative RNA-binding cleft of this polymerase and seems to inhibit the polymerase activity. Varieties of recombinant NS5B proteins (NS5B(552), NS5B(544), NS5B(536) or NS5B(531), with C-terminal 39, 47, 55 or 60 amino acid residues truncated, respectively) were systematically constructed to elucidate effects of the region on the polymerase activity. NS5B(544), NS5B(536) and NS5B(531) showed markedly higher RdRp activities compared to the activities of NS5B(570) or NS5B(552). Furthermore, when the hydrophobic amino acid residues Leu547, Trp550 and Phe551 (LWF) in NS5B(570) and NS5B(552) were changed to alanine, their activities were higher than that of the original NS5B(570). The crystal structures of the various recombinant NS5B proteins were also determined. Structural comparison of the NS5B proteins indicates that the activation was caused by elimination of a unique hydrophobic interaction between the three C-terminal residues and a shallowly concave pocket consisting of thumb and palm domains.
Subject(s)
Hepacivirus/enzymology , RNA-Dependent RNA Polymerase/chemistry , RNA-Dependent RNA Polymerase/metabolism , Amino Acid Sequence , Base Sequence , Cloning, Molecular , DNA Primers , Escherichia coli/genetics , Models, Molecular , Molecular Sequence Data , Protein Conformation , Protein Structure, Secondary , Recombinant Proteins/chemistry , Recombinant Proteins/metabolismABSTRACT
It is important to identify factors that are predictive of outcome after a curative resection in colon cancer in order to optimize adjuvant therapy. To investigate these prognostic factors we conducted a retrospective analysis of our clinicopathological data. A total of 190 patients with a pathological stage II or III colon cancer underwent potentially curative resection with lymphadenectomy at our hospital between 1990 and 1998. These patients received no preoperative chemotherapy, immunotherapy or radiotherapy. Postoperative adjuvant chemotherapy using oral fluoropyrimidines was performed in 127 patients, and the other 63 patients underwent surgery alone. Univariate and multivariate analyses for prognostic factors were carried out. The univariate analysis revealed that invasion to adjacent organs, N1-2, positive mesenteric lymph node metastasis (MLN+), lymphatic permeation (ly)1-3, venous invasion (v)1-3, and v2-3 were each significant factors indicating worse disease-free survival, and that N1-2, MLN+, ly1-3, v1-3 and v2-3 were each significant factors for worse overall survival. In the multivariate analysis, MLN+ and vl-3 were significant factors for worse disease-free survival, and for worse overall survival. In conclusion, stage II or III colon cancer patients positive for mesenteric lymph node metastasis or for venous invasion have a greater risk of recurrence and death after potentially curative resection. Postoperative adjuvant chemotherapy using oral fluoropyrimidines did not significantly reduce the risk of recurrence and death in these patients. More effective adjuvant chemotherapy than oral fluoropyrimidine should be considered, especially in such high-risk patients.
Subject(s)
Colonic Neoplasms/mortality , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Colonic Neoplasms/pathology , Colonic Neoplasms/surgery , Female , Humans , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Staging , PrognosisABSTRACT
Recent meta-analysis has shown that oral fluoropyrimidenes is effective as post-operative adjuvant therapy in stage II or III colorectal cancer. However, because the efficacy of oral fluoropyrimidines was expected to be mild, it is important to know patients who respond to this mild chemotherapy for reasonable adjuvant therapy for rectal cancer. To clarify the benefit and problems of the post-operative adjuvant chemotherapy using oral fluoropyrimidines, the clinicopathological data of 169 rectal cancer patients treated with or without the post-operative chemotherapy were analyzed retrospectively. Patients in chemotherapy group (n = 100) underwent curative resection with lymphadenectomy were followed by administration of oral fluoropyrimidine. Other 69 patients underwent surgery alone. The disease-free survival rates were compared between the two groups. The disease-free survival rate in the chemotherapy group was significantly higher than that in the surgery alone. However, no significant difference in disease-free survival rate was found for those with tumor which was associated with metastasis of mesenteric lymph node or node belonging to the internal iliac artery, and tumor with lymphatic invasion or venous invasion. Post-operative adjuvant chemotherapy using oral fluoropyrimidines such as UFT and 5'-DFUR might not reduce the risk of recurrence in rectal cancer with metastasis of mesenteric lymph node or node belonging to the internal iliac artery, and with lymphatic permeation and venous invasion.
Subject(s)
Antimetabolites, Antineoplastic/therapeutic use , Floxuridine/therapeutic use , Rectal Neoplasms/drug therapy , Tegafur/therapeutic use , Administration, Oral , Adult , Aged , Chemotherapy, Adjuvant , Female , Humans , Male , Middle Aged , Rectal Neoplasms/mortality , Rectal Neoplasms/surgery , Retrospective Studies , Survival RateABSTRACT
A critical issue in polymer-based solar cells (PSCs) is to improve the power conversion efficiency (PCE) as well as the stability. Here, we describe the development of new semiconducting polymers consisting of thiophene, thiazolothiazole and naphthobisthiadiazole in the polymer backbone. The polymers had good solubility and thus solution-processability, appropriate electronic structure with narrow band gaps of ~1.57 eV and low-lying HOMO energy levels of ~-5.40 eV, and highly ordered structure with the favorable face-on backbone orientation. Solar cells based on the polymers and PC71BM exhibited quite high PCEs of up to 9%. More interestingly, the cells also demonstrated excellent stability as they showed negligible degradation of PCE when stored at 85ËC for 500 hours in the dark under nitrogen atmosphere. These results indicate that the newly developed polymers are promising materials for PSCs in the practical use.