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1.
Psychol Med ; 48(7): 1148-1156, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28893330

RESUMO

BACKGROUND: Cognitive-behavioral therapy (CBT) is thought to be useful for chronic pain, with the pathology of the latter being closely associated with cognitive-emotional components. However, there are few resting-state functional magnetic resonance imaging (R-fMRI) studies. We used the independent component analysis method to examine neural changes after CBT and to assess whether brain regions predict treatment response. METHODS: We performed R-fMRI on a group of 29 chronic pain (somatoform pain disorder) patients and 30 age-matched healthy controls (T1). Patients were enrolled in a weekly 12-session group CBT (T2). We assessed selected regions of interest that exhibited differences in intrinsic connectivity network (ICN) connectivity strength between the patients and controls at T1, and compared T1 and T2. We also examined the correlations between treatment effects and rs-fMRI data. RESULTS: Abnormal ICN connectivity of the orbitofrontal cortex (OFC) and inferior parietal lobule within the dorsal attention network (DAN) and of the paracentral lobule within the sensorimotor network in patients with chronic pain normalized after CBT. Higher ICN connectivity strength in the OFC indicated greater improvements in pain intensity. Furthermore, ICN connectivity strength in the dorsal posterior cingulate cortex (PCC) within the DAN at T1 was negatively correlated with CBT-related clinical improvements. CONCLUSIONS: We conclude that the OFC is crucial for CBT-related improvement of pain intensity, and that the dorsal PCC activation at pretreatment also plays an important role in improvement of clinical symptoms via CBT.


Assuntos
Dor Crônica/terapia , Terapia Cognitivo-Comportamental , Giro do Cíngulo/fisiopatologia , Imageamento por Ressonância Magnética , Córtex Pré-Frontal/fisiopatologia , Adulto , Mapeamento Encefálico , Estudos de Casos e Controles , Dor Crônica/fisiopatologia , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiopatologia , Psicoterapia de Grupo , Descanso , Regressão Espacial
2.
Stud Mycol ; 90: 161-189, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29632417

RESUMO

Lophiostoma bipolare was taxonomically revised based on the morphological observations and phylogenetic analyses of molecular data from nuclear rDNA SSU-ITS-LSU, TUB, tef1, and rpb2 genes. Twenty-nine strains were morphologically similar to Lo. bipolare. A total of 174 sequences were generated from the Lo. bipolare complex. Phylogenetic analyses based on TUB sequence revealed 11 distinct species within the Lo. bipolare complex. Morphological features of the ascospores and the anatomical structure of the ascomata from both field collections as well as axenic culture, which have been reported previously as variable features at intraspecific levels, were compared to evaluate the taxonomic reliability of these features. To clarify the generic position of the 11 species, phylogenetic analyses were done on SSU-ITS-LSU-tef1-rpb2 gene sequences. The Lo. bipolare complex shared phylogenetic relationships with Pseudolophiostoma and Vaginatispora, and formed an additional five distinct clades from other members of Lophiostomataceae. According to its phylogenetic position, Lo. bipolare sensu stricto was distantly related to Lophiostoma s. str., and formed an independent clade within Lophiostomataceae. Lophiostoma bipolare s. str. could be distinguished from the other lophiostomataceous genera by the clypeus around the ostiolar neck and by the thin and uniformly thick peridium. A novel genus described as Lentistoma was established to accommodate this species, and the epitypification of Lentistoma bipolare (basionym: Massarina bipolaris) was proposed. Other lineages of the Lo. bipolare complex could not be separated on the basis of the ascospore size and sheath variations, but were distinguished based on ascomatal features, such as the existence of the clypeus, brown hyphae surrounding the peridium, and the contexture of the peridium, which were stable indicators of generic boundaries in Lophiostomataceae. Four additional new genera with five new species were recognised based on these morphological differences: Crassiclypeus (C. aquaticus), Flabellascoma (F. cycadicola and F. minimum), Leptoparies (Lep. palmarum), and Pseudopaucispora (Pseudop. brunneospora). Three new species were added to Pseudolophiostoma (Pseudol. cornisporum, Pseudol. obtusisporum, and Pseudol. tropicum) and two new species were added to Vaginatispora (V. amygdali and V. scabrispora). The re-evaluation of the validity of several previously recognised genera resulted in the introduction of two new genera with new combinations for Lophiostoma pseudoarmatisporum as Parapaucispora pseudoarmatispora and Vaginatispora fuckelii as Neovaginatispora fuckelii.

3.
Psychol Med ; 47(5): 877-888, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27894368

RESUMO

BACKGROUND: It has been demonstrated that negatively distorted self-referential processing, in which individuals evaluate one's own self, is a pathogenic mechanism in subthreshold depression that has a considerable impact on the quality of life and carries an elevated risk of developing major depression. Behavioural activation (BA) is an effective intervention for depression, including subthreshold depression. However, brain mechanisms underlying BA are not fully understood. We sought to examine the effect of BA on neural activation during other perspective self-referential processing in subthreshold depression. METHOD: A total of 56 subjects underwent functional magnetic resonance imaging scans during a self-referential task with two viewpoints (self/other) and two emotional valences (positive/negative) on two occasions. Between scans, while the intervention group (n = 27) received BA therapy, the control group (n = 29) did not. RESULTS: The intervention group showed improvement in depressive symptoms, increased activation in the dorsal medial prefrontal cortex (dmPFC), and increased reaction times during other perspective self-referential processing for positive words after the intervention. Also, there was a positive correlation between increased activation in the dmPFC and improvement of depressive symptoms. Additionally, there was a positive correlation between improvement of depressive symptoms and increased reaction times. CONCLUSIONS: BA increased dmPFC activation during other perspective self-referential processing with improvement of depressive symptoms and increased reaction times which were associated with improvement of self-monitoring function. Our results suggest that BA improved depressive symptoms and objective monitoring function for subthreshold depression.


Assuntos
Terapia Comportamental/métodos , Depressão/fisiopatologia , Depressão/terapia , Avaliação de Resultados em Cuidados de Saúde , Córtex Pré-Frontal/fisiopatologia , Autoimagem , Autocontrole , Adolescente , Adulto , Depressão/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Córtex Pré-Frontal/diagnóstico por imagem , Adulto Jovem
4.
Cancer Res ; 40(8 Pt 1): 2895-7, 1980 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7388839

RESUMO

Three isozymes of S-adenosylmethionine synthetase have been measured in the livers of rats from fetal life to maturity. A greater part of gamma-type enzyme is shown to be present in fetus and is joined by alpha- and beta-types during development. The amount of beta-type enzyme activated by dimethyl sulfoxide is very low in the fetus and rises sharply until about the 15th day after birth. The alpha-type enzyme appears after birth and increases in amount to the tenth day.


Assuntos
Isoenzimas/metabolismo , Fígado/enzimologia , Metionina Adenosiltransferase/metabolismo , Transferases/metabolismo , Fatores Etários , Animais , Dimetil Sulfóxido/farmacologia , Idade Gestacional , Cinética , Fígado/embriologia , Fígado/crescimento & desenvolvimento , Peso Molecular , Ratos , Distribuição Tecidual
5.
Transl Psychiatry ; 6: e754, 2016 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-26954981

RESUMO

Despite novel antidepressant development, 10-30% of patients with major depressive disorder (MDD) have antidepressant treatment-resistant depression (TRD). Although new therapies are needed, lack of knowledge regarding the neural mechanisms underlying TRD hinders development of new therapeutic options. We aimed to identify brain regions in which spontaneous neural activity is not only altered in TRD but also associated with early treatment resistance in MDD. Sixteen patients with TRD, 16 patients with early-phase non-TRD and 26 healthy control (HC) subjects underwent resting-state functional magnetic resonance imaging. To identify brain region differences in spontaneous neural activity between patients with and without TRD, we assessed fractional amplitude of low-frequency fluctuations (fALFF). We also calculated correlations between the percent change in the Hamilton Rating Scale for Depression (HRSD17) scores and fALFF values in brain regions with differing activity for patients with and without TRD. Patients with TRD had increased right-thalamic fALFF values compared with patients without TRD. The percent change in HRSD17 scores negatively correlated with fALFF values in patients with non-TRD. In addition, patients with TRD showed increased fALFF values in the right inferior frontal gyrus (IFG), inferior parietal lobule (IPL) and vermis, compared with patients with non-TRD and HC subjects. Our results show that spontaneous activity in the right thalamus correlates with antidepressant treatment response. We also demonstrate that spontaneous activity in the right IFG, IPL and vermis may be specifically implicated in the neural pathophysiology of TRD.


Assuntos
Transtorno Depressivo Maior/diagnóstico por imagem , Transtorno Depressivo Resistente a Tratamento/diagnóstico por imagem , Lobo Parietal/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Adulto , Antidepressivos/uso terapêutico , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Estudos de Casos e Controles , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/fisiopatologia , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Transtorno Depressivo Resistente a Tratamento/fisiopatologia , Feminino , Neuroimagem Funcional , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Lobo Parietal/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Tálamo/fisiopatologia
6.
Biochim Biophys Acta ; 884(2): 304-10, 1986 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-3768421

RESUMO

Adenine phosphoribosyltransferase has been purified to apparent homogeneity from mouse mammary tumor FM3A cells. The purified enzyme, with a specific activity of 20.6 X 10(6) units/g protein at 30 degrees C, was homogeneous as judged by polyacrylamide gel electrophoresis and Ouchterlony double immunodiffusion analysis. The native enzyme had a molecular weight of 44,000 and a subunit composition of 23,000. Apparent Km values for adenine and 5-phosphoribosyl-1-pyrophosphate (PRib-PP) were 6.6 microM and 1.2 microM, respectively. Free Mg2+ was an essential activator with a half-maximal effect at 0.4 mM. AMP was an inhibitor, competitive with PRib-PP, and the Ki value was estimated to be 24 microM. The enzyme activity was not significantly affected by 2,6-diaminopurine, 4-carbamoylimidazolium 5-olate, 8-azaadenine, and 2-fluoro-6-aminopurine. An antibody against the purified mouse adenine phosphoribosyltransferase was raised in a rabbit. The enzyme derived from either mouse, Chinese hamster, or human cells was completely neutralized and precipitated by this antibody, indicating that these enzymes share a common antigenic determinant.


Assuntos
Adenina Fosforribosiltransferase/isolamento & purificação , Neoplasias Mamárias Experimentais/enzimologia , Pentosiltransferases/isolamento & purificação , Animais , Catálise , Linhagem Celular , Eletroforese em Gel de Poliacrilamida , Imunoquímica , Camundongos , Peso Molecular
7.
Cancer Lett ; 91(1): 93-9, 1995 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-7750100

RESUMO

In vitro cultured r/mHM-SFME-1 cells were injected into the hind foot pads of Balb/c mice. Metastasis was detected in the lungs of tumor-bearing mice by means of both PCR and histological methods. Primers for the PCR were set to amplify a 128 bp exon-1 sequence of the human c-Ha-ras1 gene which had been introduced into the cells. Resulted PCR bands were densitometorically quantified using a bioimage analyzer, and more than 1 x 10(4) tumor cells were detectable in the mouse lung. The number of tumor cells per lung estimated from the amount of PCR products was 1 x 10(5), 15 x 10(5), 1 x 10(5) and 40 x 10(5) on days 7, 14, 21 and 28 respectively after the tumor injection. No metastases were histologically observed on days 7 and 14. Then, the possibility of using this model system for evaluation of a treatment against micro-metastases is discussed.


Assuntos
Genes ras , Neoplasias Pulmonares/secundário , Metástase Neoplásica/genética , Reação em Cadeia da Polimerase , Animais , Sequência de Bases , Southern Blotting , Linhagem Celular Transformada , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Metástase Neoplásica/patologia
8.
J Biochem ; 77(1?): 33-42, 1975 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-237002

RESUMO

Two cellulase [EC 3.2.1.4] components derived from Meicelase, a commercial crude cellulase preparation from Trichoderma viride, were purified by consecutive column chromatography, and were designated as cellulase II-A and cellulase II-B. Cellulases II-A and II-B were each homogeneous on polyacrylamide gel electrophoresis. The molecular weights of cellulases II-A and II-B were 30,000 and 43,000, respectively, on the basis of Sephadex G-100 gel filtration. Both enzymes contained 12-14% carbohydrates (as glucose). Some properties of the purified cellulases were investigated. The optimum pH and temperature for cellulases II-A and II-B were pH 4.5-5.0 and 60 degrees, and pH 4.5-5.0 and 50 degrees, respectively. Both enzymes were stable over the range of pH 5.0-7.0 at 4 degrees for 24 hr. Cellulases II-A and II-B retained 27 and 41% of the original CM-cellulose-saccharifying activities, respectively, after heating at 100 degrees for 10 min. Both enzymes were completely inhibited by some metal ions such as 1 mM Hg-2+, and partially by 1 mM Ag-+ and Cu-2+. However, Mg-2+, Fe-2+, and several other metal ions showed no inhibition at this concentration. The hydrolysis of CM-cellulose by cellulase II-A was more random than that by cellulase II-B.


Assuntos
Celulase/metabolismo , Glicosídeo Hidrolases/metabolismo , Fungos Mitospóricos/enzimologia , Trichoderma/enzimologia , Animais , Carboidratos/análise , Cátions Bivalentes , Celulase/isolamento & purificação , Cromatografia em Gel , Cromatografia por Troca Iônica , Estabilidade de Medicamentos , Eletroforese Descontínua , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Prata/farmacologia , Temperatura
9.
J Biochem ; 80(5): 913-22, 1976 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12153

RESUMO

A cellulase [EC 3.2.1.4] component was purified from a crude cellulase preparation of Trichoderma viride (Meicelase) by consecutive column chromatography procedures, and was designated as cellulase III. The enzyme was homogeneous on polyacrylamide gel disc electrophoresis. The molecular weight of the enzyme was estimated to be about 45,000 by gel filtration. The optimum pH and temperature of the enzyme were pH 4.5-5.0 and 50 degrees, respectively. The enzyme was stable over the range of pH 4.5-7.5 at 4 degrees for 24 hr, and retained 40% of the original carboxymethylcellulose-saccharifying activity after heating at 100 degrees for 10 min. The enzyme was completely inactivated by 1 mM Hg2+, and partially by 1 mM Ag+ and Cu2+. The enzyme was characterized as a less-random type cellulase on the basis of its action on carboxymethylcellulose. The enzyme split cellohexaose, retaining the beta-configuration of the anomeric carbon atoms in the hydrolysis products. The Km values of cellulase III for cellooligosaccharides decreased in parallel with increase of the chain length of the substrates, while Vmax values showed a tendency to increase. The enzyme produced predominantly cellobiose and glucose from various cellulosic substrates as well as from higher cellooligosaccharides. Cellulase III preferentially attacked the aglycone linkage of p-nitrophenyl beta-D-cellobioside. The enzyme was found to catalyze the rapid synthesis of cellotetraose from cellobiose (condensation action).


Assuntos
Celulase/metabolismo , Fungos Mitospóricos/enzimologia , Trichoderma/enzimologia , Carboximetilcelulose Sódica/metabolismo , Celulase/isolamento & purificação , Celulose/metabolismo , Cobre/farmacologia , Concentração de Íons de Hidrogênio , Cinética , Mercúrio/farmacologia , Peso Molecular , Oligossacarídeos/metabolismo , Prata/farmacologia , Temperatura
10.
J Biochem ; 78(2): 297-306, 1975 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6437

RESUMO

Two highly purified cellulases [EC 3.2.1.4], II-A, and II-B, were obtained from the cellulase system of Trichoderma viride. Both cellulases split cellopentaose retaining the beta-configuration of the anomeric carbon atoms in the hydrolysis products at both pH 3.5 and 5.0. The Km values of cellulases II-A and II-B for cellotetraose were different, but their Vmax values were similar and those for cellooligosaccharides increased in parallel with chain length. Both cellulases produced predominantly cellobiose and glucose from various cellulosic substrates as well as from higher cellooligosaccharides. Cellulase II-A preferentially attacked the holoside linkage of rho-nitrophenyl beta-D-cellobioside, whereas cellulase II-B attacked mainly the aglycone linkage of this cellobioside. Both cellulases were found to catalyze the synthesis of cellotriose from rho-nitrophenyl beta-D-cellobioside by transfer of a glucosyl residue, possibly to cellobiose produced in the reaction mixture. They were also found to catalyze the rapid synthesis of cellotetraose from cellobiose, with accompanying formation of cellotriose and glucose, which seemed to be produced by secondary random hydrolysis of the cellotetraose produced. The capacity to synthesize cellotetraose from cellobiose appeared to be greater with cellulase II-B than with cellulase II-A.


Assuntos
Celulase/metabolismo , Glicosídeo Hidrolases/metabolismo , Isoenzimas/metabolismo , Fungos Mitospóricos/enzimologia , Trichoderma/enzimologia , Animais , Glucosiltransferases/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Rotação Ocular , Estereoisomerismo , Relação Estrutura-Atividade
11.
J Biochem ; 91(3): 1081-4, 1982 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6804448

RESUMO

The beta-form of S-adenosylmethionine synthetase among three isozymes has been purified from rat liver, and proven to be homogeneous. The molecular weight of this enzyme was estimated to be 100,000 by gel filtration on Sephacryl S-200, and the enzyme was shown to be composed of two subunits of 48,000 daltons. A rabbit antiserum against the normal rat liver beta-form of S-adenosylmethionine synthetase was used for immunochemical characterization. The alpha- and beta-forms of isozyme are immunochemically identical, but the antiserum did not react with the gamma-form from rat kidney.


Assuntos
Isoenzimas/isolamento & purificação , Rim/enzimologia , Fígado/enzimologia , Metionina Adenosiltransferase/isolamento & purificação , Transferases/isolamento & purificação , Animais , Complexo Antígeno-Anticorpo , Soros Imunes , Imunodifusão , Peso Molecular , Ratos
12.
Anticancer Res ; 20(1A): 235-42, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10769661

RESUMO

The present study was performed to investigate whether the introduction of a wild-type p53 gene into human osteosarcoma cells could alter the growth rate and enhance the cytocidal effect of cisplatin (CDDP) and the synergistic antitumor effect of caffeine. The lipofection method was used to transfect a wild-type p53 expression plasmid into the human osteosarcoma cell line, Saos2, which has both p53 alleles deleted. The transfected cells, Saos2/p53, had a reduced growth rate compared with the parental cell line. The colorimetric WST-1 assay demonstrated that Saos2/p53 cells were twice as sensitive to CDDP alone at a 50% inhibition concentration than the parental Saos2 cells. Caffeine significantly potentiated the cytocidal effect of CDDP in the Saos2/p53 cells. Furthermore, the TUNEL assay revealed that following treatment both with CDDP alone and with CDDP combined with caffeine, a higher percentage of the Saos2/p53 cells underwent apoptosis than did the parental Saos2 cells. Therefore the cytocidal effect of CDDP and the synergistic antitumor effect of caffeine are enhanced by the introduction of a wild-type p53 gene into a human osteosarcoma cell line null for p53. This raises the possibility that gene therapy using the p53 gene may prove efficatious for human osteosarcomas lacking p53 and which are resistant to standard chemotherapy.


Assuntos
Neoplasias Ósseas/patologia , Cafeína/toxicidade , Cisplatino/toxicidade , Genes p53 , Osteossarcoma/patologia , Proteína Supressora de Tumor p53/fisiologia , Apoptose/efeitos dos fármacos , Western Blotting , Neoplasias Ósseas/genética , Cafeína/farmacologia , Cisplatino/farmacologia , Dano ao DNA , Reparo do DNA/efeitos dos fármacos , DNA de Neoplasias/análise , Sinergismo Farmacológico , Deleção de Genes , Humanos , Marcação In Situ das Extremidades Cortadas , Proteínas de Neoplasias/deficiência , Proteínas de Neoplasias/genética , Osteossarcoma/genética , Proteínas Recombinantes de Fusão/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção , Células Tumorais Cultivadas/efeitos dos fármacos , Proteína Supressora de Tumor p53/deficiência
13.
Anticancer Res ; 17(1A): 313-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9066670

RESUMO

We have studied the effects of PAI-1 on the formation of metastasis using human fibrosarcoma cells and DNA transfection. A clone (1-3C), which shows low constitutive expression of PAI-1 and low metastatic potential to the lung, was selected from human fibrosarcoma cell line HT-1080. Newly-derived clones transfected with human PAI-1 cDNA showed a 3-5 fold increase in the antigen level of PAI-1. Further, these clones demonstrated a significant increase in both the number and incidence of lung metastases when inoculated into the tail vein of athymic mice. PAI-1 could be a prognostic marker and a target for understanding the physiology of metastasis, as well as for the treatment and prevention of hematogenous lung metastasis.


Assuntos
Fibrossarcoma/patologia , Neoplasias Pulmonares/secundário , Inibidor 1 de Ativador de Plasminogênio/fisiologia , Animais , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Inibidor 1 de Ativador de Plasminogênio/genética , Transfecção , Células Tumorais Cultivadas , Ativador de Plasminogênio Tipo Uroquinase/análise
14.
Carbohydr Res ; 308(1-2): 201-5, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9675361

RESUMO

Steady-state kinetics on the reaction catalyzed by the beta-glucosidase of Aspergillus niger were carried out to evaluate the kinetic parameters, Km and ko, for phenyl beta-D-glucosides. The ko/Km values, which may relate to productive binding at subsites, were found to correlate with the substituent constant pi (hydrophobicity), suggesting that subsite 2 has a hydrophobic character. A "hydrophobic-driven" mechanism is considered to contribute to the productive E-S complex for recognition of the substrate.


Assuntos
Aspergillus niger/enzimologia , beta-Glucosidase/metabolismo , Sítios de Ligação , Glucosídeos/metabolismo , Hidrólise , Cinética , Especificidade por Substrato
15.
Carbohydr Res ; 298(1-2): 51-7, 1997 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-9076931

RESUMO

The beta-glucosidase from a commercially available preparation from Aspergillus niger was highly purified. The Michaelis constant Km and the molar activity K0 for cello-oligosaccharide substrates Gn (n = 2-6) were obtained by steady-state kinetic analysis on the beta-glucosidase-catalyzed hydrolysis at 25 degrees C and pH 5.0. Stoichiometric production of Gn-1 by the beta-glucosidase reaction for Gn was confirmed by HPLC techniques. Based on Km and K0 for Gn, subsite affinities (Ai, i = 1-6) were estimated as follows (kcal/mol): A1 = 1.3, A2 = 5.2, A3 = 0.65, A4 = -0.10, A5 = -0.65, and A6 = -0.26, of which A1-A3 are much higher than those of the beta-glucosidase of Candida wickerhamii. The subsite structure is quite similar to that of the alpha-glucosidase of A. niger, whereas the dependence of k0 on n is highly characteristic for beta-glucosidase, and decreases with n, suggesting some interaction between the particular subsites.


Assuntos
Aspergillus niger/enzimologia , beta-Glucosidase/química , Sítios de Ligação , Candida/enzimologia , Cromatografia Líquida de Alta Pressão , Cinética , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Especificidade por Substrato , beta-Glucosidase/isolamento & purificação , beta-Glucosidase/metabolismo
16.
Carbohydr Res ; 71: 287-98, 1979 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-313247

RESUMO

Crystalline alpha amylases from a number of sources utilized alpha-maltosyl fluoride as a glycosyl donor and acceptor at high rates (approximately 10 to approximately 1550 mumol/min/mg of protein, for 30 mM substrate). All enzymes catalyzed conversion of this compound into maltooligosaccharides in preference to causing its hydrolysis. Maltotetraosyl flouride and maltooligosaccharides of d.p. 3 to 6+ accounted for 75--93% (by weight) of early reaction-products. At a late stage, the yield of maltooligosaccharides was 2--5 times that of maltose, with chains as long as 12 D-glucosyl residues formed by one amylase (from Asp. oryzae), which utilized alpha-maltosyl fluoride as a donor and as an acceptor at extremely high rates. These results indicate that alpha amylases have a substantial capacity for binding two molecules of this small substrate in a distinctive way, with the C--F glycosylic bond of one and the free C-4 hydroxyl group of the other located in the region of the enzyme's catalytic groups, therby favoring glycosylation of the suitably positioned acceptor over solvent water. Hydrolysis is assumed to prevail when only a single substrate molecule or segment binds to alpha amylase with a (1 linked to 4)-alpha-D-glucosidic linkage of glycosylic C--F bond positioned at the catalytic center. The present demonstration that glycosyl-transfer reactions can be dominantly expressed by alpha amylases, given an appropriate substrate, illustrates the inadequacy of the usual characterization of these enzymes as hydrolases that produce overwhelming hydrolysis of all substrates.


Assuntos
Amilases/metabolismo , Maltose/análogos & derivados , alfa-Amilases/metabolismo , Aspergillus oryzae/enzimologia , Bacillus/enzimologia , Hidrólise , Maltose/metabolismo , Oligossacarídeos/biossíntese , Pâncreas/enzimologia
17.
J Antibiot (Tokyo) ; 49(6): 527-33, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8698634

RESUMO

Two novel diketopiperazines named tryprostatins A (1) and B (2) and a new natural product belonging to the diketopiperazine series, designated as demethoxyfumitremorgin C (3), together with four known diketopiperazines, fumitremorgin C (4), 12,13-dihydroxyfumitremorgin C (5), fumitremorgin B (6) and verruculogen (7), were isolated from the fermentation broth of Aspergillus fumigatus BM939 by the combined use of solvent extraction, silica gel column chromatography, preparative TLC and repeated-preparative HPLC. The diketopiperazines showed an inhibitory activity on the cell cycle progression of mouse tsFT210 cells in the M phase with the MIC values of 16.4 microM (1), 4.4 microM (2), 0.45 microM (3), 4.1 microM (4), 60.8 microM (5), 26.1 microM (6) and 12.2 microM (7), respectively.


Assuntos
Alcaloides Indólicos , Indóis/isolamento & purificação , Piperazinas/isolamento & purificação , Animais , Aspergillus fumigatus , Ciclo Celular/efeitos dos fármacos , Fermentação , Indóis/farmacologia , Camundongos , Piperazinas/farmacologia , Proteínas Quinases/efeitos dos fármacos
18.
J Antibiot (Tokyo) ; 54(1): 10-6, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11269706

RESUMO

A new cell growth inhibitor, curvularol, was isolated from the fermentation broth of Curvularia sp. RK97-F166. Curvularol showed no antibacterial activity, and very weak antifungal activity. However, curvularol inhibited the cell cycle progression of normal rat kidney (NRK) cells in G1 phase at 150 ng/ml. Curvularol induced the morphological reversion of srcts-transformed NRK cells at 100 ng/ml, and inhibited protein synthesis same as cycloheximide.


Assuntos
Ciclo Celular/efeitos dos fármacos , Fungos Mitospóricos/metabolismo , Inibidores da Síntese de Proteínas/isolamento & purificação , Inibidores da Síntese de Proteínas/farmacologia , Tricotecenos/isolamento & purificação , Tricotecenos/farmacologia , Animais , Linhagem Celular , DNA/biossíntese , DNA/efeitos dos fármacos , Fermentação , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Fungos Mitospóricos/classificação , Estrutura Molecular , Inibidores da Síntese de Proteínas/metabolismo , RNA/biossíntese , RNA/efeitos dos fármacos , Ratos , Tricotecenos/metabolismo , Quinases da Família src/efeitos dos fármacos , Quinases da Família src/genética , Quinases da Família src/metabolismo
19.
J Antibiot (Tokyo) ; 54(6): 489-93, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11513037

RESUMO

In the course of screening for inhibitors of intracellular trafficking of glycoprotein, a new inhibitor, F13459 was isolated from the culture broth of a Penicillium sp. It was purified using solvent extraction, silica gel, Sephadex LH-20 and ODS column chromatography. From structural analysis, F13459 was a derivative of mycophenolic acid, an inhibitor of inosine 5'-monophosphate dehydrogenase. F13459 inhibited hemagglutinin synthesis of NDV at concentrations more than 25 microg/ml. However, syncytium formation as a result of cell surface expression of F-glycoprotein of NDV was inhibited at concentrations of F13459 lower than those required for appreciable inhibition of glycoprotein synthesis.


Assuntos
Antivirais/isolamento & purificação , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/isolamento & purificação , Ácido Micofenólico/farmacologia , Penicillium/química , Animais , Antivirais/farmacologia , Células Cultivadas , Cricetinae , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Células Gigantes/efeitos dos fármacos , Hemaglutininas/biossíntese , Rim/citologia , Microscopia Eletrônica de Varredura , Vírus da Doença de Newcastle/efeitos dos fármacos , Vírus da Doença de Newcastle/metabolismo , Penicillium/classificação , Proteínas Virais de Fusão/antagonistas & inibidores , Proteínas Virais de Fusão/biossíntese
20.
Persoonia ; 26: 108-56, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22025808

RESUMO

Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola taccada, Diaporthe musigena on Musa sp., Diaporthe acaciigena on Acacia retinodes, Leptoxyphium kurandae on Eucalyptus sp., Neofusicoccum grevilleae on Grevillea aurea, Phytophthora fluvialis from water in native bushland, Pseudocercospora cyathicola on Cyathea australis, and Teratosphaeria mareebensis on Eucalyptus sp. Other species include Passalora leptophlebiae on Eucalyptus leptophlebia (Brazil), Exophiala tremulae on Populus tremuloides and Dictyosporium stellatum from submerged wood (Canada), Mycosphaerella valgourgensis on Yucca sp. (France), Sclerostagonospora cycadis on Cycas revoluta (Japan), Rachicladosporium pini on Pinus monophylla (Netherlands), Mycosphaerella wachendorfiae on Wachendorfia thyrsifolia and Diaporthe rhusicola on Rhus pendulina (South Africa). Novel genera of hyphomycetes include Noosia banksiae on Banksia aemula (Australia), Utrechtiana cibiessia on Phragmites australis (Netherlands), and Funbolia dimorpha on blackened stem bark of an unidentified tree (USA). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

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