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1.
Pediatr Nephrol ; 2024 May 02.
Article in English | MEDLINE | ID: mdl-38695892

ABSTRACT

BACKGROUND: The standard rate of sodium removal in adult anuric patients on continuous ambulatory peritoneal dialysis (CAPD) is 7.5 g/L of ultrafiltration volume (UFV). Although automated PD (APD) is widely used in pediatric patients, no attempt has yet been made to estimate sodium removal in APD. METHODS: The present, retrospective cohort study included pediatric patients with APD who were managed at Tokyo Metropolitan Children's Medical Center between July 2010 and November 2017. The patients underwent a peritoneal equilibrium test (PET) at our hospital. Sodium removal per UFV was calculated by peritoneal function and dwell time using samples from patients on APD with 1- and 2-h dwell effluent within three months of PET and 4- and 10-h dwell effluent at PET. RESULTS: In total, 217 samples from 18 patients were included, with 63, 81, and 73 of the samples corresponding to the High [H], High-average [HA], and Low-average [LA] PET category, respectively. Sodium removal per UFV (g/L in salt equivalent) for dwell times of one, two, four, and ten hours was 5.2, 8.8, 8.0, and 11.5 for PET [H], 5.3, 5.8, 5.6, and 8.1 for PET [HA], and 4.6, 5.1, 5.1, and 7.1 for PET [LA], respectively. CONCLUSIONS: Sodium removal per UFV in pediatric APD was less than the standard adult CAPD and tended to be lower with shorter dwell times, leading to sodium accumulation. Therefore, salt intake should be restricted in combination with one or more long daytime dwells, especially in anuric patients.

2.
Blood Adv ; 5(4): 984-993, 2021 02 23.
Article in English | MEDLINE | ID: mdl-33591324

ABSTRACT

Rituximab plus cyclophosphamide-doxorubicin-vincristine-prednisone (R-CHOP) is the standard of care for untreated diffuse large B-cell lymphoma (DLBCL). However, the schedule for rituximab administration has not been optimized. To compare standard R-CHOP with CHOP plus dose-dense weekly rituximab (RW-CHOP) in patients with untreated DLBCL, we conducted a phase 2/3 study (JCOG0601, jRCTs031180139). Patients were randomly assigned to R-CHOP (CHOP-21 with 8 doses of rituximab once every 3 weeks [375 mg/m2]) or RW-CHOP (CHOP-21 with 8 doses of weekly rituximab [375 mg/m2]) groups. The primary end point of the phase 2 component was percent complete response (%CR) of the RW-CHOP arm, whereas that of the phase 3 component was progression-free survival (PFS). Between December 2007 and December 2014, 421 untreated patients were randomly assigned to R-CHOP (213 patients) or RW-CHOP (208 patients). The %CR in the RW-CHOP arm was 85.3% and therefore met the prespecified decision criteria for the phase 2 component. With a median follow-up of 63.4 months, the 3-year PFS and overall survival were 79.2% and 88.7% in the R-CHOP arm and 80.3% and 90.4% in the RW-CHOP arm, respectively. There was no significant difference in PFS (hazard ratio, 0.95; 90.6% confidence interval, 0.68-1.31). Although the safety profile and efficacy of RW-CHOP was comparable with R-CHOP and its tolerability was acceptable, weekly rituximab in combination with CHOP during the early treatment period did not improve PFS in untreated patients with DLBCL. This trial was registered at jrct.niph.go.jp as #jRCTs031180139.


Subject(s)
Lymphoma, Large B-Cell, Diffuse , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cyclophosphamide/therapeutic use , Doxorubicin/therapeutic use , Humans , Lymphoma, Large B-Cell, Diffuse/drug therapy , Prednisone/therapeutic use , Rituximab/therapeutic use , Vincristine/therapeutic use
3.
Chem Res Toxicol ; 33(12): 3001-3009, 2020 12 21.
Article in English | MEDLINE | ID: mdl-33256404

ABSTRACT

Allergic contact dermatitis is a critical issue in the development of new chemicals. Minor impurities with strong skin-sensitizing properties can be generated as byproducts. However, it is very difficult to identify these skin sensitizers in product mixtures. In this study, fluorescent nitrobenzoxadiazole-labeled glutathione (NBD-GSH) was synthesized to identify small amounts of skin sensitizers in reaction mixtures. Twelve known skin sensitizers and three nonsensitizers were reacted with NBD-GSH. Adducts formed only with the skin sensitizers, which allowed for their detection by a fluorescence detector. Liquid chromatography-mass spectrometry (LC-MS) analyses showed that NBD-GSH reacted with the skin sensitizers via its thiol and amino groups. An adduct of NBD-GSH with the strong skin sensitizer 1-chloro-2,4-dinitrobenzene was detected with a limit of detection of 6 × 10-8 mol/L by high-performance liquid chromatography with fluorescence detection. When a reaction mixture from primary alcohol oxidation was incubated with NBD-GSH, a NBD-GSH adduct formed with skin-sensitizing aldehyde impurities and could be specifically detected by LC-MS with fluorescence detection. This method will be useful for detection and identification of small amounts of skin sensitizers in raw materials, intermediates, reaction mixtures, and end products in the chemical industry.


Subject(s)
4-Chloro-7-nitrobenzofurazan/analysis , Allergens/analysis , Fluorescent Dyes/analysis , Glutathione/analysis , 4-Chloro-7-nitrobenzofurazan/pharmacology , Allergens/pharmacology , Animals , Chromatography, High Pressure Liquid , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/pharmacology , Glutathione/pharmacology , Guinea Pigs , Lymph Nodes/drug effects , Molecular Structure , Skin/drug effects , Skin Tests , Spectrometry, Fluorescence
4.
Lancet Oncol ; 21(4): 593-602, 2020 04.
Article in English | MEDLINE | ID: mdl-32171071

ABSTRACT

BACKGROUND: Intravascular large B-cell lymphoma (IVLBCL) is a rare disease for which there is no available standard treatment. We aimed to ascertain the safety and activity of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) with high-dose methotrexate and intrathecal chemotherapy as CNS-oriented therapy for patients with previously untreated IVLBCL. METHODS: PRIMEUR-IVL is a multicentre, single-arm, phase 2 trial at 22 hospitals in Japan. Eligible patients had untreated histologically confirmed IVLBCL, were aged 20-79 years, had an Eastern Cooperative Group performance status of 0-3, and had no apparent CNS involvement at diagnosis. Patients received three cycles of R-CHOP (rituximab 375 mg/m2 intravenously on day 1 [except cycle one, which was on day 8]; cyclophosphamide 750 mg/m2, doxorubicin 50 mg/m2, and vincristine 1·4 mg/m2 [maximum 2·0 mg] intravenously on day 1 of cycle one and day 2 of cycles two and three; and prednisolone 100 mg/day orally on days 1-5 of cycle one and days 2-6 of cycles two and three) followed by two cycles of rituximab with high-dose methotrexate (3·5 g/m2 intravenously on day 2 of cycles four and five) every 2 weeks and three additional cycles of R-CHOP. Intrathecal chemotherapy (methotrexate 15 mg, cytarabine 40 mg, and prednisolone 10 mg) was administered four times during the R-CHOP phase. The primary endpoint was 2-year progression-free survival. Efficacy analyses were done in all enrolled patients; safety analyses were done in all enrolled and treated patients. The trial is registered in the UMIN Clinical Trials Registry (UMIN000005707) and the Japan Registry of Clinical Trials (jRCTs041180165); the trial is ongoing for long-term follow-up. FINDINGS: Between June 16, 2011, and July 21, 2016, 38 patients were enrolled, of whom 37 were eligible; one patient was excluded because of a history of testicular lymphoma. Median follow-up was 3·9 years (IQR 2·5-5·5). 2-year progression-free survival was 76% (95% CI 58-87). The most frequent adverse events of grade 3-4 were neutropenia and leucocytopenia, which were reported in all 38 (100%) patients. Serious adverse events were hypokalaemia, febrile neutropenia with hypotension, hypertension, and intracerebral haemorrhage (reported in one [3%] patient each). No treatment-related deaths occurred during protocol treatment. INTERPRETATION: R-CHOP combined with rituximab and high-dose methotrexate plus intrathecal chemotherapy is a safe and active treatment for patients with IVLBCL without apparent CNS involvement at diagnosis, and this regimen warrants future investigation. FUNDING: The Japan Agency for Medical Research and Development, the Center for Supporting Hematology-Oncology Trials, and the National Cancer Center.


Subject(s)
Antineoplastic Agents/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Lymphoma, Large B-Cell, Diffuse/drug therapy , Methotrexate/administration & dosage , Vascular Neoplasms/drug therapy , Adult , Aged , Cyclophosphamide/administration & dosage , Doxorubicin/administration & dosage , Female , Humans , Male , Middle Aged , Prednisone/administration & dosage , Prospective Studies , Rituximab/administration & dosage , Vincristine/administration & dosage , Young Adult
5.
Cancer Med ; 9(2): 678-688, 2020 01.
Article in English | MEDLINE | ID: mdl-31793218

ABSTRACT

Epstein-Barr virus (EBV)-positive B cells have been detected in 66%-86% of patients with angioimmunoblastic T-cell lymphoma (AITL). However, it remains controversial whether EBV status has an impact on the survival of patients with AITL. In this study, we aimed to reevaluate the impact of EBV on the clinicopathological characteristics of AITL. In particular, we focused on the impact of EBV in younger patients with AITL. In total, 270 cases of AITL were studied. Epstein-Barr virus-positive B cells were detected in 191 (71%) cases (EBER+ group). Among the patients who received anthracycline-based therapy, the EBER status did not affect the overall survival (OS) or progression-free survival (PFS). In the younger group of AITL (≤60 years), PFS was significantly worse in the EBER- group compared to the EBER+ group (P = .0013). Furthermore, the multivariate analysis identified EBER-negative status, thrombocytopenia, and elevated serum IgA level as significant adverse prognostic factors for PFS (P < .001, P < .001, and P = .002). Based on these findings, we constructed new prognostic model for the younger group, based on three adverse factors. We classified the patients into two risk groups: low risk (no or 1 adverse factor) and high risk (2 or 3 adverse factors). This new model for younger patients with AITL showed that both OS and PFS were significantly related to the level of risk (P < .0001). In summary, this study showed that, among younger patients with AITL, an EBER+ status significantly improved prognosis compared to an EBER- status. Our new prognostic model should be applicable to younger patients with AITL.


Subject(s)
Epstein-Barr Virus Infections/complications , Herpesvirus 4, Human/isolation & purification , Immunoblastic Lymphadenopathy/pathology , Lymphoma, T-Cell/pathology , Adult , Aged , Aged, 80 and over , Epstein-Barr Virus Infections/virology , Female , Follow-Up Studies , Humans , Immunoblastic Lymphadenopathy/epidemiology , Immunoblastic Lymphadenopathy/virology , Lymphoma, T-Cell/epidemiology , Lymphoma, T-Cell/virology , Male , Middle Aged , Prognosis , Retrospective Studies , Survival Rate
6.
Anticancer Res ; 39(7): 3579-3584, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31262882

ABSTRACT

BACKGROUND/AIM: Neuroblastoma (NB) is the most common extracranial solid tumor in childhood; treatments with greater effectiveness are required for NB, especially in advanced cases. This study aimed at evaluating the combined effect of anaplastic lymphoma kinase (ALK) inhibitor alectinib and histone deacetylase inhibitor vorinostat on NB cell lines harboring wild-type or mutated ALK. MATERIALS AND METHODS: Cytotoxicity was examined using the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay. Protein expression was analyzed using western blotting. RESULTS: Combination treatment with alectinib and vorinostat had a synergistic effect on growth inhibition of the NB cell line with ALK R1275Q mutation. Cleavage of caspase-3 and poly-(ADP-ribose) polymerase increased, indicating enhanced caspase-dependent apoptosis. In addition, this combination reduced the protein levels of MYCN proto-oncogene and nuclear factor kappa B, both of which are important for NB tumorigenesis and progression. CONCLUSION: Combined treatment with alectinib and vorinostat might be a novel therapeutic option for NB harboring the ALK R1275Q mutation.


Subject(s)
Anaplastic Lymphoma Kinase/antagonists & inhibitors , Carbazoles/pharmacology , Histone Deacetylase Inhibitors/pharmacology , Neuroblastoma/drug therapy , Piperidines/pharmacology , Protein Kinase Inhibitors/pharmacology , Vorinostat/pharmacology , Anaplastic Lymphoma Kinase/genetics , Cell Line, Tumor , Cell Survival/drug effects , Drug Synergism , Humans , Mutation , N-Myc Proto-Oncogene Protein/metabolism , NF-kappa B/metabolism , Neuroblastoma/genetics , Neuroblastoma/metabolism , Proto-Oncogene Mas
7.
Intern Med ; 58(16): 2387-2391, 2019 Aug 15.
Article in English | MEDLINE | ID: mdl-31118366

ABSTRACT

Acute promyelocytic leukemia (APL) in human immunodeficiency virus (HIV)-infected individuals is very rare. There is currently no consensus regarding the use of anti-cancer drugs with highly active anti-retroviral therapy (ART) in these patients due to their small number. We herein report two cases of APL with HIV-infected patients. Both cases received all-trans-retinoic acid-containing chemotherapies and achieved complete remission. ART was continued throughout the treatment course. The clinical course of these cases suggests that it is preferable to perform standard chemotherapy for APL with ART if patients have an adequate performance status.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antiretroviral Therapy, Highly Active/methods , HIV Infections/complications , HIV Infections/drug therapy , Leukemia, Promyelocytic, Acute/complications , Leukemia, Promyelocytic, Acute/drug therapy , Tretinoin/therapeutic use , Adult , Humans , Leukemia, Promyelocytic, Acute/diagnosis , Male , Remission Induction , Treatment Outcome
8.
Intern Med ; 57(9): 1287-1290, 2018 May 01.
Article in English | MEDLINE | ID: mdl-29279478

ABSTRACT

A 70-year-old woman with lymphadenopathy was admitted to hospital in 2008. Lymph node biopsy showed reactive lymphoid hyperplasia (RH) with monoclonal proliferation of Epstein-Barr virus (EBV). Her lymphadenopathy regressed without treatment. In 2014, the patient presented with nasal obstruction because of a left nasal mass. She was diagnosed with EBV-positive diffuse large B-cell lymphoma (DLBCL) of the elderly based on the examination of a biopsy specimen of the mass. The IgH rearrangement in the specimens from the 2008 and the 2014 revealed that they were genetically identical. This is the first report of RH progressing to DLBCL, and suggests that EBV-positive B-cells in RH lymph nodes predict the evolution to DLBCL.


Subject(s)
Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/diagnosis , Herpesvirus 4, Human/pathogenicity , Hyperplasia/etiology , Hyperplasia/pathology , Lymphadenopathy/etiology , Lymphoma, Large B-Cell, Diffuse/diagnosis , Aged , B-Lymphocytes/pathology , Epstein-Barr Virus Infections/pathology , Female , Humans , Lymphoma, Large B-Cell, Diffuse/pathology , Time Factors
9.
J Chromatogr A ; 1508: 163-168, 2017 Jul 28.
Article in English | MEDLINE | ID: mdl-28619585

ABSTRACT

High performance liquid chromatography can be coupled with nuclear magnetic resonance (NMR) spectroscopy to give a powerful analytical method known as liquid chromatography-nuclear magnetic resonance (LC-NMR) spectroscopy, which can be used to determine the chemical structures of the components of complex mixtures. However, intrinsic limitations in the sensitivity of NMR spectroscopy have restricted the scope of this procedure, and resolving these limitations remains a critical problem for analysis. In this study, we coupled ultra-high performance liquid chromatography (UHPLC) with NMR to give a simple and versatile analytical method with higher sensitivity than conventional LC-NMR. UHPLC separation enabled the concentration of individual peaks to give a volume similar to that of the NMR flow cell, thereby maximizing the sensitivity to the theoretical upper limit. The UHPLC concentration of compound peaks present at typical impurity levels (5.0-13.1 nmol) in a mixture led to at most three-fold increase in the signal-to-noise ratio compared with LC-NMR. Furthermore, we demonstrated the use of UHPLC-NMR for obtaining structural information of a minor impurity in a reaction mixture in actual laboratory-scale development of a synthetic process. Using UHPLC-NMR, the experimental run times for chromatography and NMR were greatly reduced compared with LC-NMR. UHPLC-NMR successfully overcomes the difficulties associated with analyses of minor components in a complex mixture by LC-NMR, which are problematic even when an ultra-high field magnet and cryogenic probe are used.


Subject(s)
Chromatography, High Pressure Liquid/instrumentation , Magnetic Resonance Spectroscopy/instrumentation , Alanine/chemistry , Chromatography, High Pressure Liquid/methods , Magnetic Resonance Spectroscopy/methods , Sensitivity and Specificity , Signal-To-Noise Ratio
10.
Anticancer Res ; 35(12): 6679-84, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26637884

ABSTRACT

BACKGROUND: Bendamustine is effective in B-cell malignancies, including mantle cell lymphoma (MCL), alone and in combination with other agents. This study investigated the combination effect of bendamustine and the Bruton tyrosine kinase (BTK) inhibitor PCI-32765 on MCL cell death and the underlying mechanisms. MATERIALS AND METHODS: Cytotoxicity was examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MIT) assay. Apoptosis was assessed by annexin V/propidium iodide staining and protein expression was analyzed by western blotting. RESULTS: When combined with bendamustine, PCI-32765 showed a synergistic effect on growth inhibition of the MCL cell line Jeko-1. Cleavage of caspase-3 and poly-(ADP-ribose) polymerase was increased, indicating enhanced apoptosis induction. In addition, this combination decreased the protein expression of cyclin D1. Phosphorylated v-akt murine thymoma viral oncogene homolog 1 (AKT) (Ser473) was also down-regulated, suggesting a suppression of the phosphatidylinositol 3-kinase/AKT signaling pathway. CONCLUSION: Combination treatment with bendamustine and a BTK inhibitor may be effective in MCL therapy.


Subject(s)
Bendamustine Hydrochloride/therapeutic use , Lymphoma, Mantle-Cell/drug therapy , Pyrazoles/therapeutic use , Pyrimidines/therapeutic use , Adenine/analogs & derivatives , Bendamustine Hydrochloride/administration & dosage , Bendamustine Hydrochloride/pharmacology , Cell Proliferation , Humans , Lymphoma, Mantle-Cell/pathology , Piperidines , Pyrazoles/administration & dosage , Pyrazoles/pharmacology , Pyrimidines/administration & dosage , Pyrimidines/pharmacology , Signal Transduction
11.
Nihon Rinsho ; 72(3): 538-41, 2014 Mar.
Article in Japanese | MEDLINE | ID: mdl-24724416

ABSTRACT

Hodgkin lymphoma became to be a curative disease. The standard treatment has been established for Hodgkin lymphoma, but its optimization still is explored. Risk stratification is critical in terms of optimization. The favorable patients would be treated with less toxic regimens. PET results are now used to evaluate the treatment response, and recently interim PET has been shown as a good predictor of prognosis. Interim PET is now incorporated into the treatment strategy of Hodgkin lymphoma in clinical trials. Molecular targeting drugs have been developed. Brentuximab vedotin, a kind of antibody drug conjugate, showed favorable clinical results for relapsed Hodgkin lymphoma.


Subject(s)
Hodgkin Disease/therapy , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Chemoradiotherapy , Humans
12.
Cancer Sci ; 105(1): 35-43, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24147568

ABSTRACT

CD20 is expressed in most B-cell lymphomas and is a critical molecular target of rituximab. Some B-cell lymphomas show aberrant CD20 expression, and rituximab use in these patients is controversial. Here we show both the molecular mechanisms and the clinical significance of de novo diffuse large B-cell lymphomas (DLBCL) that show a CD20 immunohistochemistry (IHC)-positive and flow cytometry (FCM)- negative (IHC[+]/FCM[-]) phenotype. Both IHC and FCM using anti-CD20 antibodies L26 and B1, respectively, were analyzed in 37 of the 106 cases of de novo DLBCL; 8 (22%) of these cases were CD79a(+)/CD20(+) with IHC and CD19(+)/CD20(-) with FCM. CD20 (MS4A1) mRNA expression was significantly lower in IHC(+)/FCM(-) cells than in IHC(+)/FCM(+) cells (P = 0.0005). No genetic mutations were detected in MS4A1 promoter and coding regions. Rituximab-mediated cytotoxicity in the CDC assay using IHC(+)/FCM(-) primary cells was significantly lower than in IHC(+)/FCM(+) cells (P < 0.05); however, partial effectiveness was confirmed. FCM using rituximab detected CD20 more efficiently than B1. No significant difference was observed between IHC(+)/FCM(-) and IHC(+)/FCM(+) patients in overall survival (P = 0.664). Thus, lower expression of CD20 mRNA is critical for the CD20 IHC(+)/FCM(-) phenotype. Lower CD20 expression with FCM does not rule out rituximab use in these patients if expression is confirmed with IHC. FCM using rituximab may be more informative than B1 for predicting rituximab effectiveness in IHC(+)/FCM(-) cases.


Subject(s)
Antibodies, Monoclonal, Murine-Derived/pharmacology , Antigens, CD20/metabolism , Antineoplastic Agents/pharmacology , Lymphoma, Large B-Cell, Diffuse/drug therapy , Lymphoma, Large B-Cell, Diffuse/metabolism , Adult , Aged , Aged, 80 and over , Animals , Antibodies, Monoclonal, Murine-Derived/administration & dosage , Antigens, CD20/genetics , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cell Line, Tumor , Female , Flow Cytometry/methods , Humans , Immunohistochemistry/methods , Lymphoma, Large B-Cell, Diffuse/genetics , Lymphoma, Large B-Cell, Diffuse/pathology , Male , Mice , Mice, SCID , Middle Aged , Phenotype , Rituximab , Survival Rate
13.
Blood ; 119(12): 2837-43, 2012 Mar 22.
Article in English | MEDLINE | ID: mdl-22308294

ABSTRACT

Angioimmunoblastic T-cell lymphoma (AITL) is a major type of peripheral T-cell lymphoma (PTCL). To elucidate the clinicopathologic characteristics and prognosis of AITL in Japan, we retrospectively analyzed 207 patients with AITL. The median patient age was 67 years (range, 34-91 years), with 73% of patients older than 60 years. With a median follow-up of 42 months in surviving patients, 3-year overall survival (OS) was 54% and progression-free survival (PFS) was 38%. The International Prognostic Index (IPI) and the prognostic index for PTCL, not otherwise specified (PIT) were predictive for OS in this analysis. Multivariate analysis found that age older than 60 years, elevated white blood cell (WBC) and IgA levels, the presence of anemia and thrombocytopenia, and extranodal involvement at > 1 site were significant prognostic factors for OS, and IgA, anemia, and mediastinal lymphadenopathy were significant prognostic factors for PFS. A novel prognostic model consisting of the prognostic factors for OS was successfully constructed. In conclusion, IPI and PIT were still useful for prognostication of AITL, and other factors, including those not used in IPI, such as IgA, anemia, WBC count, thrombocytopenia, and mediastinal lymphadenopathy, also significantly affected prognosis. Future investigations for IgA as a unique prognostic factor are warranted.


Subject(s)
Immunoglobulin A/blood , Lymphoma, T-Cell/immunology , Lymphoma, T-Cell/mortality , Adult , Aged , Aged, 80 and over , Antineoplastic Agents/therapeutic use , Disease-Free Survival , Female , Hematopoietic Stem Cell Transplantation , Humans , Immunoblastic Lymphadenopathy/mortality , Immunohistochemistry , Immunophenotyping , Japan , Kaplan-Meier Estimate , Lymphoma, T-Cell/therapy , Male , Middle Aged , Prognosis , Proportional Hazards Models , Retrospective Studies
15.
Anal Chem ; 82(10): 4293-7, 2010 May 15.
Article in English | MEDLINE | ID: mdl-20411921

ABSTRACT

Chiral separation by high performance liquid chromatography (Chiral HPLC) is one of the most powerful methods for estimating optical and chemical purity of chiral compounds. However, it has a weakness in that much time and effort are required to prepare authentic samples. A novel chiral liquid chromatography-circular dichroism-NMR (LC-CD-NMR) technique, on the other hand, requires only crude chiral compounds that include enantiomers as minor impurities. In this study, chiral LC-CD-NMR was constructed by connecting a conventional LC-NMR system with a CD detector. A pyridylalanine derivative mixture was prepared to mimic technical grade material in an early phase of development. By chiral LC-CD-NMR, the enantiomer peak is identified by an opposite sign of the CD Cotton effect curve and an identical (1)H NMR spectrum to that of the main component. Using NMR as a detector, this method is superior in ability to discriminate enantiomers from other isomers indistinguishable by MS. Furthermore, this method is also applicable for selecting the best separation conditions of chiral HPLC. The degrees of separation (Rs) between the main component and its enantiomer in several chiral columns were compared. Even with modern chromatographic methods, establishing the best chiral HPLC conditions in an early phase of development is difficult: chiral LC-CD-NMR is a suitable solution.


Subject(s)
Chromatography, High Pressure Liquid/methods , Chromatography, Liquid/methods , Circular Dichroism/methods , Magnetic Resonance Imaging/methods , Pharmaceutical Preparations , Stereoisomerism , Task Performance and Analysis
16.
Plant Cell ; 20(7): 1833-49, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18621947

ABSTRACT

Plastidial phosphorylase (Pho1) accounts for approximately 96% of the total phosphorylase activity in developing rice (Oryza sativa) seeds. From mutant stocks induced by N-methyl-N-nitrosourea treatment, we identified plants with mutations in the Pho1 gene that are deficient in Pho1. Strikingly, the size of mature seeds and the starch content in these mutants showed considerable variation, ranging from shrunken to pseudonormal. The loss of Pho1 caused smaller starch granules to accumulate and modified the amylopectin structure. Variation in the morphological and biochemical phenotype of individual seeds was common to all 15 pho1-independent homozygous mutant lines studied, indicating that this phenotype was caused solely by the genetic defect. The phenotype of the pho1 mutation was temperature dependent. While the mutant plants grown at 30 degrees C produced mainly plump seeds at maturity, most of the seeds from plants grown at 20 degrees C were shrunken, with a significant proportion showing severe reduction in starch accumulation. These results strongly suggest that Pho1 plays a crucial role in starch biosynthesis in rice endosperm at low temperatures and that one or more other factors can complement the function of Pho1 at high temperatures.


Subject(s)
Mutation , Oryza/metabolism , Phosphorylases/metabolism , Plant Proteins/metabolism , Starch/metabolism , Base Sequence , Gene Expression Regulation, Enzymologic , Gene Expression Regulation, Plant , Microscopy, Electron, Scanning , Models, Biological , Molecular Sequence Data , Oryza/genetics , Oryza/ultrastructure , Phenotype , Phosphorylases/genetics , Plant Proteins/genetics , Plants, Genetically Modified/enzymology , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Plants, Genetically Modified/ultrastructure , Plastids/enzymology , Reverse Transcriptase Polymerase Chain Reaction , Seeds/genetics , Seeds/metabolism , Seeds/ultrastructure , Starch/chemistry , Starch/ultrastructure , Temperature
17.
Plant Physiol ; 144(4): 2009-23, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17586688

ABSTRACT

Starch synthase IIIa (SSIIIa)-deficient rice (Oryza sativa) mutants were generated using retrotransposon insertion and chemical mutagenesis. The lowest migrating SS activity bands on glycogen-containing native polyacrylamide gel, which were identified to be those for SSIIIa, were completely absent in these mutants, indicating that they are SSIIIa null mutants. The amylopectin B(2) to B(4) chains with degree of polymerization (DP) >/= 30 and the M(r) of amylopectin in the mutant were reduced to about 60% and 70% of the wild-type values, respectively, suggesting that SSIIIa plays an important part in the elongation of amylopectin B(2) to B(4) chains. Chains with DP 6 to 9 and DP 16 to 19 decreased while chains with DP 10 to 15 and DP 20 to 25 increased in the mutants amylopectin. These changes in the SSIIIa mutants are almost opposite images of those of SSI-deficient rice mutant and were caused by 1.3- to 1.7-fold increase of the amount of SSI in the mutants endosperm. Furthermore, the amylose content and the extralong chains (DP >/= 500) of amylopectin were increased by 1.3- and 12-fold, respectively. These changes in the composition in the mutants starch were caused by 1.4- to 1.7-fold increase in amounts of granules-bound starch synthase (GBSSI). The starch granules of the mutants were smaller with round shape, and were less crystalline. Thus, deficiency in SSIIIa, the second major SS isozyme in developing rice endosperm affected the structure of amylopectin, amylase content, and physicochemical properties of starch granules in two ways: directly by the SSIIIa deficiency itself and indirectly by the enhancement of both SSI and GBSSI gene transcripts.


Subject(s)
Oryza/enzymology , Seeds/metabolism , Starch Synthase/metabolism , Starch/biosynthesis , Isoenzymes/metabolism , Methylnitrosourea , Molecular Sequence Data , Mutagenesis, Insertional , Oryza/genetics , Oryza/metabolism , Retroelements , Seeds/ultrastructure , Starch/chemistry , Starch/ultrastructure , Starch Synthase/genetics
18.
Bioorg Med Chem ; 14(24): 8259-70, 2006 Dec 15.
Article in English | MEDLINE | ID: mdl-17010619

ABSTRACT

Novel cyclic thiopeptides, cyclothiazomycins B1 (1) and B2 (2), were isolated from Streptomyces sp. A307 as potent hyphal swelling inducing substances. They are stable in the solid state but slowly isomerize with one another in solution. Degradation experiments and spectroscopic analyses disclosed that they comprise unique tricyclic structures each containing a dehydroalanine, and two dehydrohomoalanine residues, along with three thiazolines, three thiazoles, and a trisubstituted pyridine. Cyclothiazomycin B1 (1) is expected to be a powerful tool for DNA-RNA transcription studies, because this cyclopeptide inhibits DNA-dependent RNA synthesis by bacteriophage RNA polymerases.


Subject(s)
DNA-Directed RNA Polymerases/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Peptides, Cyclic/pharmacology , Peptides/pharmacology , Thiazoles/pharmacology , Chromatography, High Pressure Liquid , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/isolation & purification , Fermentation , Isomerism , Magnetic Resonance Spectroscopy , Molecular Structure , Peptides/chemistry , Peptides/isolation & purification , Peptides, Cyclic/chemistry , Peptides, Cyclic/isolation & purification , Renin/antagonists & inhibitors , Streptomyces/classification , Streptomyces/metabolism , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/isolation & purification
19.
Hippocampus ; 14(5): 570-85, 2004.
Article in English | MEDLINE | ID: mdl-15301435

ABSTRACT

Several subtypes of voltage-dependent calcium channels (VDCCs) are present in the presynaptic terminals. In the mammalian hippocampus, P/Q-, N-, and R- but not L-type VDCCs are involved in the fast transmitter release from large mossy fiber (MF) boutons, which are associated with CA3 pyramidal cell dendrites. We investigated whether L-type VDCCs are indeed absent in these large MF boutons. With the use of Sr2+ as the Ca2+ substitute, the stimulus-evoked Sr2+ increment (delta[Sr2+]pre) was evaluated fluorometrically. Delta[Sr2+]pre appeared to be proportional to Sr2+ inflow through VDCCs and was specifically attenuated by conventional VDCC subtype-selective antagonists. The P/Q-type selective omega-agatoxin IVA (AgTx(IVA)) blocked delta[Sr2+]pre with an IC50 of 28 nM and by 30-35% at its maximum effective concentration of 0.5 microM. The N-type selective omega-conotoxin GVIA (CgTx(GVIA)) blocked delta[Sr2+]pre with an IC50 of 15 nM and by 20-25% at its maximum effective concentration of 1 microM. The R-type selective SNX-482 blocked delta[Sr2+]pre with an IC50 of 79 nM and by 20-25% at its maximum effective concentration of 1 microM. The effects of these toxins did not overlap at their maximum effective concentrations and about 70-80% of delta[Sr +]pre was blocked by the simultaneous exposure to these toxins. delta[Sr2+]pre component that is resistant to AgTx(IVA), CgTx(IVA), and SNX-482 was significantly potentiated by an L-type agonist, (S)-(-)-Bay K8644, and attenuated by an L-type antagonist, nimodipine, suggesting that L-type VDCCs are present in large MF terminals. The L-type agonist, (+/-)-Bay K8644, also potentiated Sr2+ inflow into individual boutons identified as large MF boutons under confocal microscopy. Almost similar results were observed for Ca2+ inflow-dependent fluorescence increments. L-type VDCCs appear to be present in large MF boutons and mediate a substantial Ca2+ inflow into presynaptic terminals during action potentials.


Subject(s)
Action Potentials/physiology , Calcium Channels, L-Type/metabolism , Mossy Fibers, Hippocampal/metabolism , Presynaptic Terminals/metabolism , Strontium/metabolism , Synaptic Transmission/physiology , 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology , Action Potentials/drug effects , Animals , Animals, Newborn , Calcium Channel Blockers/pharmacology , Calcium Channels, L-Type/drug effects , Calcium Signaling/drug effects , Calcium Signaling/physiology , Fluorescent Dyes , In Vitro Techniques , Mice , Mice, Inbred BALB C , Mossy Fibers, Hippocampal/drug effects , Mossy Fibers, Hippocampal/ultrastructure , Spider Venoms/pharmacology , Strontium/pharmacology , Synaptic Membranes/drug effects , Synaptic Membranes/metabolism , Synaptic Membranes/ultrastructure , Synaptic Transmission/drug effects , omega-Agatoxin IVA/pharmacology , omega-Conotoxin GVIA/pharmacology
20.
J Chromatogr A ; 1043(2): 333-5, 2004 Jul 23.
Article in English | MEDLINE | ID: mdl-15330109

ABSTRACT

Analysis of alpha-amino acids, proteins, and phenolic compounds was simultaneously performed using three capillaries in capillary electrophoresis with chemiluminescence detection, taking advantage of the micro-space area for reaction/detection at the tip of the capillary. The three capillaries included usual, polymer-containing, and sodium docley sulfate (SDS)-containing migration buffers for separation. The eluted samples from the capillaries, which were inserted into the chemiluminescence detection cell, were mixed with chemiluminescence reagent at the tips of the capillaries to generate visible light. The specific micro-space area for reaction/detection at the tips of the capillaries enabled the simultaneous operation of the three separation modes in the present system.


Subject(s)
Electrophoresis, Capillary/methods , Luminescence
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