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1.
Transpl Infect Dis ; 17(6): 909-14, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26426682

RESUMEN

Post-transplant lymphoproliferative disorder (PTLD) is one of the life-threatening complications after hematopoietic stem cell transplantation (HSCT) and solid organ transplantation (SOT), and it is associated almost exclusively with Epstein-Barr virus (EBV). We herein report 2 cases of EBV-associated PTLD after allogeneic HSCT localized in the adrenal gland. Both patients developed adrenal tumor within 3 months after HSCT and were successfully treated with rituximab or tapering immunosuppressive agents. Both remained alive without recurrence. A literature review revealed 12 reported cases of PTLD involving the adrenal gland, but the adrenal gland was involved as one of the lesions of advanced-stage PTLD after SOT. To the best of our knowledge, this is the first report to show cases of isolated EBV-associated adrenal PTLD after HSCT. PTLD should be recognized as one of the causes of isolated adrenal tumor after HSCT.


Asunto(s)
Enfermedades de las Glándulas Suprarrenales/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Trastornos Linfoproliferativos/etiología , Enfermedades de las Glándulas Suprarrenales/tratamiento farmacológico , Enfermedades de las Glándulas Suprarrenales/patología , Adulto , Antineoplásicos/uso terapéutico , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/uso terapéutico , Trastornos Linfoproliferativos/tratamiento farmacológico , Trastornos Linfoproliferativos/patología , Masculino , Rituximab/uso terapéutico , Adulto Joven
2.
Sci Rep ; 12(1): 22182, 2022 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-36564489

RESUMEN

Chromosome damage combined with defective recombinase activity has been widely considered to render cells inviable, owing to deficient double-strand break repair. However, temperature-sensitive recAts polA cells grow well upon induction of DNA damage and supplementation with catalase at restrictive temperatures. These treatments reduce intracellular reactive oxygen species (ROS) levels, which suggests that recAts polA cells are susceptible to ROS, but not chronic chromosome damage. Therefore, we investigated whether polA cells can tolerate a complete lack of recombinase function. We introduced a ΔrecA allele in polA cells in the presence or absence of the hslO-encoding redox molecular chaperon Hsp33 expression plasmid. Induction of the hslO gene with IPTG resulted in increased cell viability in ΔrecA polA cells with the hslO expression plasmid. ΔrecA polA cells in the absence of the hslO expression plasmid showed rich medium sensitivity with increasing ROS levels. Adding catalase to the culture medium considerably rescued growth arrest and decreased ROS. These results suggest that hslO expression manages oxidative stress to an acceptable level in cells with oxidative damage and rescues cell growth. Overall, ROS may regulate several processes, from damage response to cell division, via ROS-sensitive cell metabolism.


Asunto(s)
Daño del ADN , Estrés Oxidativo , Catalasa/genética , Catalasa/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Recombinasas/metabolismo
3.
J Cell Biol ; 125(6): 1371-84, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8207064

RESUMEN

To examine the functions of ERM family members (ezrin, radixin, and moesin), mouse epithelial cells (MTD-1A cells) and thymoma cells (L5178Y), which coexpress all of them, were cultured in the presence of antisense phosphorothioate oligonucleotides (PONs) complementary to ERM sequences. Immunoblotting revealed that the antisense PONs selectively suppressed the expression of each member. Immunofluorescence microscopy of these ezrin, radixin, or moesin "single-suppressed" MTD-1A cells revealed that the ERM family members are colocalized at cell-cell adhesion sites, microvilli, and cleavage furrows, where actin filaments are densely associated with plasma membranes. The ezrin/radixin/moesin antisense PONs mixture induced the destruction of both cell-cell and cell-substrate adhesion, as well as the disappearance of microvilli. Ezrin or radixin antisense PONs individually affected the initial step of the formation of both cell-cell and cell-substrate adhesion, but did not affect the microvilli structures. In sharp contrast, moesin antisense PONs did not singly affect cell-cell and cell-substrate adhesion, whereas it partly affected the microvilli structures. These data indicate that ezrin and radixin can be functionally substituted, that moesin has some synergetic functional interaction with ezrin and radixin, and that these ERM family members are involved in cell-cell and cell-substrate adhesion, as well as microvilli formation.


Asunto(s)
Adhesión Celular/fisiología , Proteínas del Citoesqueleto , Proteínas de Unión al ADN/genética , Proteínas de Microfilamentos , Microvellosidades/fisiología , Oligonucleótidos Antisentido/farmacología , Factores de Transcripción/genética , Animales , Secuencia de Bases , Proteínas Sanguíneas/genética , Adhesión Celular/efectos de los fármacos , Técnica del Anticuerpo Fluorescente , Leucemia L5178 , Proteínas de la Membrana/genética , Ratones , Microscopía Electrónica de Rastreo , Microvellosidades/efectos de los fármacos , Microvellosidades/ultraestructura , Datos de Secuencia Molecular , Fosfoproteínas/genética , Proteínas/genética , Tionucleótidos/farmacología , Timoma/ultraestructura
4.
J Clin Invest ; 106(2): 299-308, 2000 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10903346

RESUMEN

CSX/NKX2.5 is an evolutionarily conserved homeodomain-containing (HD-containing) transcription factor that is essential for early cardiac development. Recently, ten different heterozygous CSX/NKX2.5 mutations were found in patients with congenital heart defects that are transmitted in an autosomal dominant fashion. To determine the consequence of these mutations, we analyzed nuclear localization, DNA binding, transcriptional activation, and dimerization of mutant CSX/NKX2.5 proteins. All mutant proteins were translated and located to the nucleus, except one splice-donor site mutant whose protein did not accumulate in the cell. All mutants that had truncation or missense mutations in the HD had severely reduced DNA binding activity and little or no transcriptional activation function. In contrast, mutants with intact HDs exhibit normal DNA binding to the monomeric binding site but had three- to ninefold reduction in DNA binding to the dimeric binding sites. HD missense mutations that preserved homodimerization ability inhibited the activation of atrial natriuretic factor by wild-type CSX/NKX2.5. Although our studies do not characterize the genotype-phenotype relationship of the ten human mutations, they identify specific abnormalities of CSX/NKX2.5 function essential for transactivation of target genes.


Asunto(s)
Bloqueo Cardíaco/genética , Cardiopatías/congénito , Defectos del Tabique Interatrial/genética , Proteínas de Homeodominio/genética , Mutación , Factores de Transcripción/genética , Proteínas de Xenopus , Compartimento Celular , Dimerización , Proteína Homeótica Nkx-2.5 , Humanos , Mutación Missense , Proteínas Nucleares/genética , Unión Proteica , Biosíntesis de Proteínas , Empalme del ARN , Eliminación de Secuencia , Activación Transcripcional
5.
J Clin Invest ; 94(3): 1026-36, 1994 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8083344

RESUMEN

Autoimmune myocarditis is considered to play a major role in the pathogenesis of dilated cardiomyopathy. A new autoimmune myocarditis model was attained by repeated immunization using murine cardiac C-protein with the immunological adjuvant, Klebsiella pneumoniae O3 lipopolysaccharide. For further analysis of a pathological epitope, the cDNA encoding C-protein was isolated; a fusion protein encoded by part of this cDNA induced myocarditis in SMA mice as well as in three other strains: DBA/1J (H-2q), O20/A (H-2pz1), and SJL (H-2s). The nucleotide sequence and its deduced amino acid analysis revealed that this protein had immunoglobulin-like and fibronectin-like repeats. This study provides a new animal model of autoimmune myocarditis which may shed light on the pathogenesis of dilated cardiomyopathy.


Asunto(s)
Autoanticuerpos/sangre , Enfermedades Autoinmunes/patología , Cardiomiopatía Dilatada/inmunología , Lipopolisacáridos/toxicidad , Proteínas Musculares/toxicidad , Miocarditis/inmunología , Miocarditis/patología , Miocardio/patología , Adulto , Anciano , Secuencia de Aminoácidos , Animales , Enfermedades Autoinmunes/inducido químicamente , Cardiomiopatía Dilatada/sangre , Proteínas Portadoras , Clonación Molecular , ADN Complementario/metabolismo , Femenino , Corazón/efectos de los fármacos , Humanos , Inflamación , Klebsiella pneumoniae , Lipopolisacáridos/administración & dosificación , Masculino , Ratones , Ratones Endogámicos DBA , Ratones Endogámicos , Persona de Mediana Edad , Proteínas Musculares/biosíntesis , Miocarditis/inducido químicamente , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes/toxicidad , Valores de Referencia , Mapeo Restrictivo , Homología de Secuencia de Aminoácido
6.
J Clin Invest ; 108(2): 189-201, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11457872

RESUMEN

A DNA nonbinding mutant of the NK2 class homeoprotein Nkx2.5 dominantly inhibits cardiogenesis in Xenopus embryos, causing a small heart to develop or blocking heart formation entirely. Recently, ten heterozygous CSX/NKX2.5 homeoprotein mutations were identified in patients with congenital atrioventricular (AV) conduction defects. All four missense mutations identified in the human homeodomain led to markedly reduced DNA binding. To examine the effect of a DNA binding-impaired mutant of mouse Csx/Nkx2.5 in the embryonic heart, we generated transgenic mice expressing one such allele, I183P, under the beta-myosin heavy chain promoter. Unexpectedly, transgenic mice were born apparently normal, but the accumulation of Csx/Nkx2.5(I183P) mutant protein in the embryo, neonate, and adult myocardium resulted in progressive and profound cardiac conduction defects and heart failure. P-R prolongation observed at 2 weeks of age rapidly progressed into complete AV block as early as 4 weeks of age. Expression of connexins 40 and 43 was dramatically decreased in the transgenic heart, which may contribute to the conduction defects in the transgenic mice. This transgenic mouse model may be useful in the study of the pathogenesis of cardiac dysfunction associated with CSX/NKX2.5 mutations in humans.


Asunto(s)
Nodo Atrioventricular/fisiopatología , Cardiopatías Congénitas/fisiopatología , Insuficiencia Cardíaca/etiología , Proteínas de Homeodominio/metabolismo , Miocardio/metabolismo , Factores de Transcripción/metabolismo , Proteínas de Xenopus , Factores de Edad , Animales , Animales Recién Nacidos , Nodo Atrioventricular/anomalías , Peso Corporal , Conexina 43/metabolismo , Conexinas/metabolismo , Modelos Animales de Enfermedad , Regulación hacia Abajo , Ecocardiografía , Femenino , Corazón/embriología , Corazón/crecimiento & desarrollo , Cardiopatías Congénitas/complicaciones , Insuficiencia Cardíaca/genética , Insuficiencia Cardíaca/metabolismo , Proteína Homeótica Nkx-2.5 , Proteínas de Homeodominio/genética , Masculino , Ratones , Ratones Transgénicos , Mutación , Miocardio/patología , Miocardio/ultraestructura , Tamaño de los Órganos , Factores de Transcripción/genética , Proteína alfa-5 de Unión Comunicante
7.
Mol Cell Biol ; 19(1): 526-36, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9858576

RESUMEN

Csx/Nkx2.5, a member of the homeodomain-containing transcription factors, serves critical developmental functions in heart formation in vertebrates and nonvertebrates. In this study the putative nuclear localization signal (NLS) of Csx/Nkx2.5 was identified by site-directed mutagenesis to the amino terminus of the homeodomain, which is conserved in almost all homeodomain proteins. When the putative NLS of Csx/Nkx2.5 was mutated a significant amount of the cytoplasmically localized Csx/Nkx2.5 was unphosphorylated, in contrast to the nuclearly localized Csx/Nkx2.5, which is serine- and threonine-phosphorylated, suggesting that Csx/Nkx2.5 phosphorylation is regulated, at least in part, by intracellular localization. Tryptic phosphopeptide mapping indicated that Csx/Nkx2.5 has at least five phosphorylation sites. Using in-gel kinase assays, we detected a Csx/Nkx2.5 kinase whose molecular mass is approximately 40 kDa in both cytoplasmic and nuclear extracts. Mutational analysis and in vitro kinase assays suggested that this 40-kDa Csx/Nkx2.5 kinase is a catalytic subunit of casein kinase II (CKII) that phosphorylates the serine residue between the first and second helix of the homeodomain. This CKII site is phosphorylated in vivo. CKII-dependent phosphorylation of the homeodomain increased Csx/Nkx2. 5 DNA binding. Serine-to-alanine mutation at the CKII phosphorylation site reduced transcriptional activity when the carboxyl-terminal repressor domain was deleted. Although the precise biological function of Csx/Nkx2.5 phosphorylation by CKII remains to be determined, it may play an important role, as this CKII phosphorylation site within the homeodomain is fully conserved in all known members of the NK2 family of the homeobox genes.


Asunto(s)
Proteínas de Homeodominio/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Factores de Transcripción/metabolismo , Proteínas de Xenopus , Sitios de Unión , Quinasa de la Caseína II , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Proteínas de Unión al ADN/metabolismo , Factor de Transcripción GATA4 , Genes Homeobox , Proteína Homeótica Nkx-2.5 , Proteínas de Homeodominio/genética , Mutagénesis , Miocardio , Señales de Localización Nuclear , Fosforilación , Factores de Transcripción/genética , Transcripción Genética
8.
Mol Cell Biol ; 18(6): 3120-9, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9584153

RESUMEN

Specification and differentiation of the cardiac muscle lineage appear to require a combinatorial network of many factors. The cardiac muscle-restricted homeobox protein Csx/Nkx2.5 (Csx) is expressed in the precardiac mesoderm as well as the embryonic and adult heart. Targeted disruption of Csx causes embryonic lethality due to abnormal heart morphogenesis. The zinc finger transcription factor GATA4 is also expressed in the heart and has been shown to be essential for heart tube formation. GATA4 is known to activate many cardiac tissue-restricted genes. In this study, we tested whether Csx and GATA4 physically associate and cooperatively activate transcription of a target gene. Coimmunoprecipitation experiments demonstrate that Csx and GATA4 associate intracellularly. Interestingly, in vitro protein-protein interaction studies indicate that helix III of the homeodomain of Csx is required to interact with GATA4 and that the carboxy-terminal zinc finger of GATA4 is necessary to associate with Csx. Both regions are known to directly contact the cognate DNA sequences. The promoter-enhancer region of the atrial natriuretic factor (ANF) contains several putative Csx binding sites and consensus GATA4 binding sites. Transient-transfection assays indicate that Csx can activate ANF reporter gene expression to the same extent that GATA4 does in a DNA binding site-dependent manner. Coexpression of Csx and GATA4 synergistically activates ANF reporter gene expression. Mutational analyses suggest that this synergy requires both factors to fully retain their transcriptional activities, including the cofactor binding activity. These results demonstrate the first example of homeoprotein and zinc finger protein interaction in vertebrates to cooperatively regulate target gene expression. Such synergistic interaction among tissue-restricted transcription factors may be an important mechanism to reinforce tissue-specific developmental pathways.


Asunto(s)
Factor Natriurético Atrial/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Homeodominio/metabolismo , Miocardio/metabolismo , Factores de Transcripción/metabolismo , Dedos de Zinc , Animales , Factor Natriurético Atrial/biosíntesis , ADN/metabolismo , Factor de Transcripción GATA4 , Expresión Génica , Proteína Homeótica Nkx-2.5 , Ratones , Unión Proteica , Activación Transcripcional
9.
Rev Sci Instrum ; 78(8): 083502, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17764321

RESUMEN

An O-mode reflectometer at a frequency of 25.85 GHz was applied to plasmas heated by the high harmonic fast wave (21 MHz) in the TST-2 spherical tokamak. An oscillation in the phase of the reflected microwave in the rf range was observed directly for the first time. In TST-2, the rf (250 kW) induced density oscillation depends mainly on the poloidal rf electric field, which is estimated to be about 0.2 kV/m rms by the reflectometer measurement. Sideband peaks separated in frequency by ion cyclotron harmonics from 21 MHz, and peaks at ion cyclotron harmonics which are suggested to be quasimodes generated by parametric decay, were detected.


Asunto(s)
Electrones , Gases/química , Gases/efectos de la radiación , Oscilometría/instrumentación , Ondas de Radio , Radiometría/instrumentación , Diseño Asistido por Computadora , Diseño de Equipo , Análisis de Falla de Equipo , Oscilometría/métodos , Dosis de Radiación , Radiometría/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
10.
Blood Cancer J ; 7(9): e601, 2017 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-28862699

RESUMEN

Although the introduction of tyrosine kinase inhibitors (TKIs) has improved overall survival of patients with chronic myeloid leukemia (CML), about half of the patients eventually relapse after cessation of TKIs. In contrast, the remainder of the patients maintain molecular remission without TKIs, indicating that the patients' immune system could control proliferation of TKI-resistant leukemic stem cells (LSCs). However, the precise mechanism of immunity against CML-LSCs is not fully understood. We have identified a novel immune target, CXorf48, expressed in LSCs of CML patients. Cytotoxic T cells (CTLs) induced by the epitope peptide derived from CXorf48 recognized CD34+CD38- cells obtained from the bone marrow of CML patients. We detected CXorf48-specific CTLs in the peripheral blood mononuclear cells from CML patients who have discontinued imatinib after maintaining complete molecular remission for more than 2 years. Significantly, the relapse rate of CXorf48-specific CTL-negative patients was 63.6%, compared to 0% in CXorf48-specific CTL-positive patients. These results indicate that CXorf48 could be a promising therapeutic target of LSCs for immunotherapy to obtain durable treatment-free remission in CML patients.


Asunto(s)
Células de la Médula Ósea/inmunología , Linfocitos T CD8-positivos/inmunología , Regulación Leucémica de la Expresión Génica/inmunología , Leucemia Mielógena Crónica BCR-ABL Positiva/inmunología , Proteínas de Neoplasias/inmunología , Células Madre Neoplásicas/inmunología , Células de la Médula Ósea/patología , Linfocitos T CD8-positivos/patología , Femenino , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Humanos , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Masculino , Células Madre Neoplásicas/patología , Células THP-1
11.
Cell Death Differ ; 22(9): 1437-50, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25613378

RESUMEN

Adenine nucleotide translocases (ANTs) transport ADP and ATP through mitochondrial inner membrane, thus playing an essential role for energy metabolism of eukaryotic cells. Mice have three ANT paralogs, Ant1 (Slc25a4), Ant2 (Slc25a5) and Ant4 (Slc25a31), which are expressed in a tissue-dependent manner. While knockout mice have been characterized with Ant1 and Ant4 genes, which resulted in exercise intolerance and male infertility, respectively, the role of the ubiquitously expressed Ant2 gene in animal development has not been fully demonstrated. Here, we generated Ant2 hypomorphic mice by targeted disruption of the gene, in which Ant2 expression is largely depleted. The mice showed apparently normal embryonic development except pale phenotype along with a reduced birth rate. However, postnatal growth was severely retarded with macrocytic anemia, B lymphocytopenia, lactic acidosis and bloated stomach, and died within 4 weeks. Ant2 depletion caused anemia in a cell-autonomous manner by maturation arrest of erythroid precursors with increased reactive oxygen species and premature deaths. B-lymphocyte development was similarly affected by Ant2 depletion, and splenocytes showed a reduction in maximal respiration capacity and cellular ATP levels as well as an increase in cell death accompanying mitochondrial permeability transition pore opening. In contrast, myeloid, megakaryocyte and T-lymphocyte lineages remained apparently intact. Erythroid and B-cell development may be particularly vulnerable to Ant2 depletion-mediated mitochondrial dysfunction and oxidative stress.


Asunto(s)
Translocador 2 del Nucleótido Adenina/deficiencia , Linfocitos B/citología , Eritrocitos/citología , Eritropoyesis/fisiología , Linfopoyesis/fisiología , Translocasas Mitocondriales de ADP y ATP/metabolismo , Translocador 2 del Nucleótido Adenina/genética , Translocador 2 del Nucleótido Adenina/metabolismo , Adenosina Trifosfato/metabolismo , Anemia/genética , Anemia/metabolismo , Animales , Linfocitos B/metabolismo , Eritrocitos/metabolismo , Eritropoyesis/genética , Femenino , Técnicas de Inactivación de Genes , Trastornos del Crecimiento/genética , Trastornos del Crecimiento/metabolismo , Humanos , Linfopoyesis/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/genética , Mitocondrias/metabolismo
12.
Arch Surg ; 134(3): 287-92, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10088570

RESUMEN

OBJECTIVE: To evaluate the effect of enteral nutrition (EN) in attenuating bacterial and/or endotoxin translocation, maintaining immune responsiveness, and improving outcome in early acute pancreatitis (AP) in Wistar male rats. DESIGN: Acute pancreatitis was induced in rats receiving total parenteral nutrition (TPN) (AP/TPN group) (n=34) and EN (AP/EN group) (n=35) by pressure injection of 1% deoxycholate into the biliopancreatic duct (0.6 mg/kg of body weight). Rats in the sham/TPN and sham/EN groups (n=10 each) underwent laparotomy without induction of AP. Catheters for TPN and EN were placed into the external jugular vein and jejunum, respectively. Rats were infused with Ringer lactate solution for 48 hours followed by TPN in the AP/TPN and sham/TPN groups, and EN in the AP/EN and sham/EN groups until day 7. The fluid volume and energy (calories) intake were similar in all groups. SETTING: Medical school research laboratory. MAIN OUTCOME MEASURES: Survival, blood endotoxin level, villus height, 5-bromo-2'-deoxyuridine (BrdU) uptake in the jejunum and ileum, bacterial culture of mesenteric lymph nodes, and CD4/CD8 ratio of T cells in mesenteric lymph nodes, spleen, and peripheral blood. RESULTS: There was no difference in survival and pancreatic healing between the AP/TPN and AP/EN groups. Colony-forming units of the mesenteric lymph nodes and the endotoxin level were significantly lower in the AP/EN group than in the AP/TPN group (P<.05). Villus height and BrdU intake was significantly higher in the AP/EN group than in the AP/TPN group (P<.05). The CD4/CD8 ratio of T cells in spleen and peripheral blood was higher in the AP/EN group than in the AP/TPN group (P<.05), whereas there was no difference in mesenteric lymph nodes. CONCLUSIONS: Jejunal administration of EN is well tolerated in early AP, maintains immune responsiveness and gut integrity, and reduces bacterial and/or endotoxin translocation. However, compared with TPN, EN does not improve outcome. These results suggest that factors other than bacterial and/or endotoxin translocation may be responsible for mortality in this rat model of early AP. However, additional studies of both early bacterial and/or endotoxin translocation and late assessment of outcome are indicated.


Asunto(s)
Traslocación Bacteriana , Nutrición Enteral , Pancreatitis/microbiología , Enfermedad Aguda , Animales , Masculino , Ratas , Ratas Wistar
13.
Phytochemistry ; 38(2): 343-6, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7772304

RESUMEN

The biotransformation of an acyclic neolignan, (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4' neolignan, in rats has been investigated. After administration of (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4'-++ +neolignan to rat by intraperitoneal injection, urine and faeces were collected. A small amount of (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'- dimethoxy)-8-O-4'-neolignan and its metabolic product were obtained from an ethyl acetate extract of the urine, and the largest amount of the same metabolic product was obtained from a dichloromethane extract of the faeces. The sole metabolic product was identified as (+)-(4-hydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4'-neolignan++ + by spectroscopic methods. Furthermore, biotransformation of (+)-erythro-(4,7-dihydro-3-methoxy-1'-allyl-3',5'- dimethoxy)-8-O-4'-neolignan by intestinal bacteria in rat faeces was also investigated in vitro. Consequently, (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4'-++ +neolignan was reduced to the same metabolic product and no other metabolic products were produced. These results suggested that intestinal bacteria were concerned in the specific dehydroxylation of (+)-erythro-(4,7-dihydroxy-3-methoxy-1'-allyl-3',5'-dimethoxy)-8-O-4'-++ +neolignan in rats.


Asunto(s)
Lignanos/farmacocinética , Animales , Biotransformación , Heces/química , Lignanos/orina , Masculino , Ratas
14.
Phytochemistry ; 43(1): 111-3, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8987506

RESUMEN

Biotransformation of the 7,7'-epoxylignans, (+)-veraguensin, (+)-galbelgin and galgravin by Aspergillus niger has been investigated. These lignans were converted to their corresponding 4,4'-O-demethyl derivatives, (+)-verrucosin, (+)-fragransin A2 and nectandrin B.


Asunto(s)
Aspergillus niger/metabolismo , Furanos/farmacocinética , Lignanos , Biotransformación , Furanos/química , Cromatografía de Gases y Espectrometría de Masas , Espectroscopía de Resonancia Magnética , Metilación
15.
Phytochemistry ; 44(8): 1479-82, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9094220

RESUMEN

Microbial transformation of (+/-)-eudesmin by Aspergillus niger was investigated. Enantioselective accumulation of (--)-pinoresinol was shown through O-demethylation of (+/-)-eudesmin. This fungus O- demethylated both enantiomers of eudesmin, but the conversion rates for each enantiomer were clearly different.


Asunto(s)
Aspergillus niger/metabolismo , Furanos/farmacocinética , Lignanos , Biotransformación , Furanos/metabolismo , Metilación , Estereoisomerismo
16.
Int J Cardiol ; 64(2): 171-7, 1998 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-9688436

RESUMEN

Platelets are known to play a crucial role in normal hemostasis as well as in thrombus formation at sites exposed to blood flow, as in coronary thrombosis. Thus, low platelet count is a strong negative risk factor for the occurrence of arterial thrombosis, such as occurs in acute myocardial infarction. We encountered a patient with May-Hegglin anomaly, presenting with acute myocardial infarction in his sixth decade, even though his platelet counts had always been less than 50 x 10(3)/microl. We investigated the characteristics of his platelets under the effect of shearing and found that shear-induced platelet aggregation and binding of soluble von Willebrand factor (vWF) to platelets could be induced, even when the patient's platelet count was less than 10 x 10(3)/microl, but that virtually no aggregation or vWF binding by normal platelets could be induced by shearing when platelet counts were less than 50 x 10(3)/microl. We conclude that the low platelet counts in a patient with May-Hegglin anomaly can be functionally compensated for by larger individual platelets, in view of the vWF-dependent platelet thrombus formation occurring under the effect of blood flow and that that is why most patients with May-Hegglin anomaly do not have a bleeding tendency, even though their platelet counts are very low.


Asunto(s)
Plaquetas/citología , Enfermedades Hematológicas/complicaciones , Infarto del Miocardio/etiología , Trombocitopenia/sangre , Plaquetas/química , Plaquetas/metabolismo , Enfermedades Hematológicas/sangre , Hemorreología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Agregación Plaquetaria , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/análisis , Complejo GPIb-IX de Glicoproteína Plaquetaria/análisis , Trombocitopenia/complicaciones , Factor de von Willebrand/metabolismo
17.
Nutrition ; 12(6): 436-9, 1996 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8875539

RESUMEN

After hepatectomy, purine and pyrimidine metabolism is a key process in synthesis of DNA and RNA and in energy metabolism. To supply nucleosides for salvage synthesis, nucleoside-nucleotide mixture solutions have been developed, and they have been found to improve protein metabolism and hepatic regeneration after partial hepatectomy in normal rats. However, the effect of the solution in cirrhotic liver, common in patients with hepatocellular carcinoma, has not been reported. The aim of this study was to evaluate the metabolic effect of the nucleoside-nucleotide mixture on cirrhotic rats after partial hepatectomy. Seventy percent partial hepatectomy was performed in thioacetamide-administered cirrhotic rats. The fractional protein synthetic rate, nitrogen balance, hepatic content of nucleic acid, and blood chemistry after the administration of the nucleoside-nucleotide mixture solution (OG-VI) with total parenteral nutrition was evaluated at 7 d after partial hepatectomy. OG-VI increased hepatic RNA level and hepatic fractional protein synthetic rate (p < 0.05). It is concluded that the nucleoside-nucleotide mixture solution is an effective nutritional supplement to the metabolism of cirrhotic rats after partial hepatectomy.


Asunto(s)
Hepatectomía , Cirrosis Hepática Experimental/metabolismo , Hígado/metabolismo , Nucleósidos/administración & dosificación , Nucleótidos/administración & dosificación , Nutrición Parenteral Total , Animales , ADN/metabolismo , Hígado/patología , Cirrosis Hepática Experimental/inducido químicamente , Cirrosis Hepática Experimental/patología , Masculino , Nitrógeno/metabolismo , Biosíntesis de Proteínas , ARN/metabolismo , Ratas , Ratas Wistar , Tioacetamida
18.
Nutrition ; 12(11-12): 797-803, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8974107

RESUMEN

After hepatectomy, purine and pyrimidine metabolism is a key process in the synthesis of DNA and RNA and maintaining cellular energy metabolism. The purpose of this study is to evaluate changes in blood purine and pyrimidine levels after partial hepatectomy and the effect of purine and pyrimidine nucleoside solution injection on hepatic regeneration under the hypothesis that the rat after partial hepatectomy requires substrates for salvage nucleotide synthesis and changes blood nucleoside and nucleobase levels. Blood levels of nucleotides, nucleosides, and nucleobase by high-performance liquid chromatography method and liver ATP level by enzymatic analysis, and the effect of preoperative injection of nucleoside solution (OG-VI) on hepatic regeneration ratio and hepatocytes DNA synthesis, were assessed in rats after 70% partial hepatectomy. Decreased liver adenosine triphosphate and increased plasma xanthine and hypoxanthine after partial hepatectomy indicated an increase in catabolism of purine nucleotides in regenerating liver. Plasma thymidine and cytidine levels increased, then returned to the prevalue, suggesting that the thymidine and cytidine pool was enlarged. OG-VI increased labeling indices of hepatocytes at postoperative d 1 (POD) and hepatic regeneration ratio at POD 14. Blood purine nucleobase and pyrimidine nucleoside levels change after partial hepatectomy and preoperative supply of nucleoside solution is effective for increasing hepatocytes DNA synthesis and hepatic regeneration after partial hepatectomy.


Asunto(s)
Hepatectomía , Regeneración Hepática/efectos de los fármacos , Nucleósidos/farmacología , Nucleótidos/farmacología , Adenosina Trifosfato/metabolismo , Animales , Cromatografía Líquida de Alta Presión , ADN/biosíntesis , Cinética , Masculino , Purinas/sangre , Purinas/farmacología , Pirimidinas/sangre , Pirimidinas/farmacología , ARN/biosíntesis , Ratas , Ratas Wistar , Soluciones , Ácido Úrico/sangre
19.
J Antibiot (Tokyo) ; 28(2): 118-21, 1975 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-1112762

RESUMEN

A new antibiotic, lysocellin (K-5610), WAS ISOLATED FROM Streptomyces cacaoi var. asoensis K-9 Met-. Lysocellin was obtained as a colorless crystalline needles from both the cultural filtrate and the mycelium of the organism. The antibiotic melted at 158 similar to 160 degrees C and had a molecular formula C34H59O10Na-1/2H2O. It had antimicrobial activity against gram-positive bacteria, antibiotic-resistant Staphyloccus aureus and some fungi, but not against gram-negative bacteria. Based on its physico-chemical and biological properties lysocellin was identified as a new polyether antibiotic.


Asunto(s)
Antibacterianos/aislamiento & purificación , Animales , Antibacterianos/análisis , Antibacterianos/farmacología , Antifúngicos/análisis , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Bacterias/efectos de los fármacos , Fenómenos Químicos , Química , Química Física , Farmacorresistencia Microbiana , Éteres/aislamiento & purificación , Éteres/farmacología , Ratones , Staphylococcus/efectos de los fármacos , Streptomyces/análisis
20.
J Biosci Bioeng ; 90(6): 681-3, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-16232933

RESUMEN

The transesterification activity of powder lipase prepared from the purified lipase of Rhizopus chinensis cells by freeze-drying was quite low compared with that of acetone-dried cells. Additives which could enhance the transesterification activity of the freeze-dried powder lipase were screened. The freeze-dried lipases prepared with certain fatty acid methylesters or certain types of surfactants exhibited high transesterification activity. It was shown that not only the solubility of the freeze-dried lipase in n-hexane but also the organic solvent-stability was enhanced when methyl stearate was added to the lipase solution at the freeze-drying step.

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