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1.
Plant Biol (Stuttg) ; 25(5): 687-695, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37070345

RESUMO

The reproductive characteristics of understory bamboo and the effects of dieback on overstory tree seedlings through temporal changes in the environment at the forest floor have only been examined in a few bamboo species, due to the unpredictable occurrence of flowering events and long intervals between them but provide valuable information on tree regeneration and succession in a forest with dense dwarf bamboo cover. We investigated environmental conditions and assessed seedlings (< 30-cm tall) of the dwarf bamboo Sasa borealis and overstory tree species at 44-50 measurement points during 2016-2021, which included a S. borealis mass flowering event in 2017. We also conducted seed germination tests to determine germination rates and patterns in S. borealis. Environmental factors affecting seedling recruitment of S. borealis and of overstory trees were analysed using spatiotemporal generalized linear mixed models in the Bayesian framework. We observed gradual temporal changes in the environment, including increasing canopy openness and decreasing maximum height of dead S. borealis culms. The seeds germinated slowly and the emergence of current-year S. borealis seedlings peaked in spring-summer in 2019. The tree seedling density after 2019 increased significantly compared to that before the dieback. The model results suggest that tree seedling establishment was enhanced by increased light availability. Continuous field observation beginning before S. borealis dieback revealed gradually enhanced tree recruitment in response to slow decay of the remaining dead culms and slow recovery of S. borealis. The seedling regeneration pattern of understory bamboo partly contributes to a prolonged opportunity for overstory tree regeneration.


Assuntos
Florestas , Plântula , Japão , Teorema de Bayes , Plântula/fisiologia , Germinação , Ecossistema
2.
Benef Microbes ; 6(4): 441-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25653155

RESUMO

This double-blind, placebo-controlled clinical trial was conducted to test whether Lactobacillus gasseri TMC0356 (TMC0356) can modify the immune response in the elderly. Heat-killed TMC0356 or placebo was orally administered to 28 healthy subjects aged 50-70 years old for 4 weeks at a dosage of 1.0×10(9) cfu/day. Peripheral blood mononuclear cells (PBMCs) were collected from the subjects before and after the study completion, together with general health and blood examination records. Isolated PBMCs were examined for the number of T cells, CD8(+)CD28(+) cells, native T cells, B cells, natural killer (NK) cells and the ratios of CD4/CD8 T cells and native/memory T cells. NK cell activation and concanavalin A-induced lymphocyte transformation of the isolated PBMCs were also examined. The number of CD8(+) T cells significantly increased in the subjects after TMC0356 oral administration (P<0.05). Furthermore, the population of CD8(+)CD28(+) T cells and the amount of lymphocyte transformation both significantly decreased in PBMCs from the placebo group (P<0.05). However, such changes were not observed in the subjects exposed to TMC0356. These results suggest that TMC0356 can increase the number of CD8(+) T cells and reduce CD28 expression loss in CD8(+) T cells of the elderly. The effect of TMC0356 on immune responses in the elderly may enhance their natural defence mechanisms against pathogenic infections.


Assuntos
Fatores Imunológicos/administração & dosagem , Lactobacillus/imunologia , Leucócitos Mononucleares/imunologia , Probióticos/administração & dosagem , Administração Oral , Idoso , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Concanavalina A/metabolismo , Método Duplo-Cego , Temperatura Alta , Humanos , Fatores Imunológicos/efeitos da radiação , Lactobacillus/efeitos da radiação , Contagem de Leucócitos , Masculino , Viabilidade Microbiana/efeitos da radiação , Pessoa de Meia-Idade , Placebos/administração & dosagem , Probióticos/efeitos da radiação , Resultado do Tratamento
3.
Br J Radiol ; 87(1041): 20140240, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25029296

RESUMO

OBJECTIVE: A planning target volume (PTV) margin formula for hypofractionated intracranial stereotactic radiotherapy (SRT) has been proposed under cone beam CT (CBCT) image guidance with a six-degrees-of-freedom (6-DOF) robotic couch. METHODS: CBCT-based registration using a 6-DOF couch reportedly led to negligibly small systematic positioning errors, suggesting that each in-treatment positioning error during the treatment courses for the patients employing this combination was predominantly caused by a random gaussian process. Under this assumption, an anisotropic PTV margin for each axis was formulated based on a gaussian distribution model. 19 patients with intracranial lesions who underwent additional post-treatment CBCT were consecutively selected, to whom stereotactic hypofractionated radiotherapy was delivered by a linear accelerator equipped with a CBCT imager, a 6-DOF couch and a mouthpiece-assisted mask system. Time-averaged patient-positioning errors during treatment were estimated by comparing the post-treatment CBCT with the reference planning CT images. RESULTS: It was suggested that each histogram of the in-treatment positioning error in each axis would approach each single gaussian distribution with a mean of zero. The calculated PTV margins in the x, y and z directions were 0.97, 1.30 and 0.88 mm, respectively. CONCLUSION: The empirical isotropic PTV margin of 2 mm used in our facility for intracranial SRT was consistent with the margin calculated by the proposed gaussian model. ADVANCES IN KNOWLEDGE: We have proposed a PTV margin formula for hypofractionated intracranial SRT under CBCT image guidance with a 6-DOF robotic couch.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Procedimentos Cirúrgicos Robóticos , Cirurgia Assistida por Computador , Adulto , Idoso , Idoso de 80 Anos ou mais , Fracionamento da Dose de Radiação , Desenho de Equipamento , Feminino , Humanos , Imageamento Tridimensional , Masculino , Máscaras , Pessoa de Meia-Idade , Posicionamento do Paciente , Radiocirurgia/instrumentação
4.
J Appl Microbiol ; 113(1): 155-62, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22519947

RESUMO

AIMS: To investigate the influence of heat-killed Lactobacillus gasseri TMC0356 on changes in respiratory immune function and intestinal microbiota in a diet-induced obese mouse model. METHODS AND RESULTS: Male C57BL/6J mice were fed a high-fat diet for 16 weeks. After 8 weeks, the high-fat-diet-induced obese mice (DIO mice) were randomly divided into two 0067roups, the DIO and DIO0356 groups. DIO0356 group mice were orally fed with heat-killed TMC0356 every day for 8 weeks, while DIO group mice were exposed to 0·85% NaCl over the same time period as controls. After intervention, the pulmonary mRNA expression of cytokines and other immune molecules in DIO0356 mice compared to those in DIO group mice was significantly increased (P < 0·05, P < 0·01). In faecal bacterial profiles, analysed using the terminal restriction fragment length polymorphism (T-RFLP) method, T-RFLP patterns in 75% of the DIO0356 group mice were apparently changed compared with those in control group mice. CONCLUSION: These results suggest that inactive lactobacilli may stimulate the respiratory immune responses of obese host animals to enhance their natural defences against respiratory infection, partially associating with their potent impact on intestinal microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: We have demonstrated that oral administration of inactive lactobacilli may protect host animals from the lung immune dysfunction caused by obesity.


Assuntos
Intestinos/microbiologia , Lactobacillus/imunologia , Pulmão/imunologia , Metagenoma , Obesidade/imunologia , Administração Oral , Animais , Citocinas/genética , Citocinas/metabolismo , Dieta Hiperlipídica/efeitos adversos , Fezes/microbiologia , Mucosa Intestinal/metabolismo , Células Matadoras Naturais/imunologia , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Obesidade/microbiologia , Polimorfismo de Fragmento de Restrição , Probióticos/administração & dosagem , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Baço/citologia , Baço/imunologia
5.
Lett Appl Microbiol ; 53(2): 210-6, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21623846

RESUMO

AIMS: The aim of this study was to investigate the influence of heat treatment and culture media on the immunoregulatory effects of a probiotic strain, Lactobacillus gasseri TMC0356 (TMC0356). METHODS AND RESULTS: TMC0356 cultured in deMan-Rogosa-Sharpe and same food grade (FG) media were inactivated with the heat treatment at 70 and 90°C. Viable and heat-killed TMC0356 were tested for their ability to induce interleukin (IL)-12 production in the murine macrophage cell line J774.1. These TMC0356 were examined for their resistance to N-acetylmuramidase. Their morphology was observed by scanning electron microscopy. The heat-killed TMC0356 significantly induced IL-12 production in J774.1 cells and exhibited enhanced resistance to N-acetylmuramidase compared with viable TMC0356. Morphological changes were observed in TMC0356 when cultured in FG medium. Cell morphology and induction of IL-12 production in J774.1 cells were also associated. CONCLUSIONS: These results suggest that heat treatment and culture medium composition modified the immunoregulatory effects of TMC0356 to induce IL-12 production in macrophages. SIGNIFICANCE AND IMPACT OF THE STUDY: These results demonstrate that probiotic immunoregulatory effects may be modified by the processing technology of cell preparation.


Assuntos
Meios de Cultura/metabolismo , Lactobacillus/crescimento & desenvolvimento , Probióticos/farmacologia , Animais , Linhagem Celular , Glicosídeo Hidrolases/toxicidade , Temperatura Alta , Interleucina-12/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Viabilidade Microbiana
6.
Br J Radiol ; 82(976): 328-31, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19064600

RESUMO

Dose verification of intensity-modulated arc therapy using an ERGO++ treatment planning system and Elekta internal multileaf collimators is described. Prostate intensity-modulated arc therapy was planned using the arc modulation optimization algorithm inverse planning module of ERGO++. After transferring the plan to Elekta Synergy's controller (Elekta Ltd, Crawley, UK), the isocentre dose was measured and compared with a calculated dose using a pinpoint chamber and a water phantom in a cylindrical acrylic enclosure. Subsequently, an EDR2 film was placed inside a multilayer plastic phantom, and total dose distributions were measured in three axial planes as well as in the coronal and sagittal planes to compare the actual dose with the calculated dose. The dose discrepancy at the isocentre was 1.7%. The calculated gamma indices were less than 1 over 90% of the three axial planes, as well as in the coronal and sagittal planes, having a dose greater than 50% of the maximum target dose.


Assuntos
Interpretação de Imagem Assistida por Computador/instrumentação , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/instrumentação , Radioterapia de Intensidade Modulada/métodos , Algoritmos , Humanos , Masculino , Doses de Radiação , Dosagem Radioterapêutica , Rotação
7.
Mol Genet Genomics ; 269(4): 562-73, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12827498

RESUMO

The GAS1-related genes of fungi encode GPI-anchored proteins with beta-1,3-glucanosyltransferase activity. Loss of this activity results in defects in the assembly of the cell wall. We isolated mutants that show a synthetic defect when combined with a gas1Delta allele in Saccharomyces cerevisiae, and identified nine wild-type genes that rescue this defect. The indispensability of BIG1 and KRE6 for the viability of gas1Delta cells confirmed the important role of beta-1,6-glucan in cells that are defective in the processing of beta-1,3-glucan. The identification of the Wsc1p hypo-osmotic stress sensor and components of the PKC signal transduction pathway in our screen also confirmed that the cell wall integrity response attenuates the otherwise lethal gas1Delta defect. Unexpectedly, we found that the KEX2 gene is also required for the viability of the gas1Delta mutant. Kex2p is a Golgi/endosome-membrane-anchored protease that processes secretory preproteins. A cell wall defect was also found in the kex2Delta mutant, which was suppressible by multiple copies of the MKC7 or YAP3 gene, both of which encode other GPI-anchored proteases. Therefore, normal cell wall assembly requires proteolytic processing of secretory preproteins. Furthermore, the genes CSG2 and IPT1 were found to be required for normal growth of gas1Delta cells in the presence of 1 M sorbitol. This finding suggests that complex sphingolipids play a role in the hyper-osmotic response.


Assuntos
Genes Letais , Glicoproteínas de Membrana/genética , Pró-Proteína Convertases , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Parede Celular/genética , Parede Celular/metabolismo , Mutação , Saccharomyces cerevisiae/metabolismo , Subtilisinas/genética , Subtilisinas/metabolismo
8.
Int J Pharm ; 236(1-2): 35-42, 2002 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-11891068

RESUMO

The effects of ethanol on the simultaneous transport and metabolism of methyl p-hydroxybenzoate (HBM) were investigated in the skin of Yucatan micropig in vitro. It was found that transesterification occurred in the permeation studies involving ethanol. This was confirmed by monitoring the flux of ethyl p-hydroxybenzoate (HBE) into the receptor phase, as well as by monitoring the fluxes of HBM and p-hydroxybenzoic acid (HBA). The apparent flux of total HBM was decreased. The solubility of HBM increased with ethanol concentration, thus, the activity of HBM in ethanol solution became low because we used 10 mM HBM solution for permeation studies. The enhancement factor (E) was calculated to correct the activity. E increased with increasing the flux of ethanol, thus, ethanol may function as an enhancer of HBM transport. The hydrolysis of HBM to HBA was inhibited, whereas transesterification of HBM to HBE was induced at all concentrations of ethanol used (10-40%). The formation of HBE occurred much more readily than that of HBA at all concentrations of ethanol used.


Assuntos
Depressores do Sistema Nervoso Central/farmacocinética , Etanol/farmacocinética , Parabenos/farmacocinética , Veículos Farmacêuticos/farmacocinética , Pele/metabolismo , Animais , Feminino , Parabenos/metabolismo , Suínos , Porco Miniatura
9.
Yeast ; 18(11): 1003-14, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11481671

RESUMO

Saccharomyces cerevisiae Sly1 protein is a member of the Sec1/Munc18-family proteins, which are essential for vesicular trafficking, but their exact biological roles are yet to be determined. A temperature-sensitive sly1 mutant arrests the vesicular transport from the ER to Golgi compartments at 37 degrees C. We screened for multicopy suppressor genes that restore the colony formation of the sly1(ts) mutant to discover functionally interacting components. The suppressor genes obtained were classified as: (1) those that encode a multifunctional suppressor, SSD1; (2) heat shock proteins, SSB1 and SSB2; (3) cell surface proteins, WSC1, WSC2 and MID2; (4) ER-Golgi transport proteins, USO1 and BET1; and (5) an as-yet-uncharacterized protein, HSD1 (high-copy suppressor of SLY1 defect 1). By epitope tagging of the gene product, we found that Hsd1 protein is an ER-resident membrane protein. Its overproduction induced enlargement of ER-like membrane structures.


Assuntos
Proteínas de Transporte/genética , Retículo Endoplasmático/metabolismo , Proteínas Fúngicas/genética , Genes Supressores , Complexo de Golgi/metabolismo , Proteínas de Membrana Transportadoras , Proteínas Repressoras/genética , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Proteínas de Transporte Vesicular , Sequência de Aminoácidos , Proteínas de Transporte/metabolismo , Mapeamento de Epitopos , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Dosagem de Genes , Genes Fúngicos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Proteínas Munc18 , Mutação , Transporte Proteico , Proteínas Qc-SNARE , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo , Proteínas SNARE , Saccharomyces cerevisiae/metabolismo , Temperatura
10.
J Exp Biol ; 204(Pt 4): 685-90, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11171350

RESUMO

Measurement of the time allocation of penguins at sea has been a major goal of researchers in recent years. Until now, however, no equipment has been available that would allow measurement of the aquatic and terrestrial behaviour of an Antarctic penguin while it is commuting between the colony and the foraging grounds. A new motion detector, based on the measurement of acceleration, has been used here in addition to current methods of inferring behaviour using data loggers that monitor depth and speed. We present data on the time allocation of Adélie penguins (Pygoscelis adeliae) according to the different types of behaviours they display during their foraging trips: walking, tobogganing, standing on land, lying on land, resting at the water surface, porpoising and diving. To illustrate the potential of this new technique, we compared the behaviour of Adélie penguins during the chick-rearing period in a fast sea-ice region and an ice-free region. The proportion of time spent standing, lying on land and walking during foraging trips was greater for penguins in the sea-ice region (37.6+/-13.3% standing, 21.6+/-15.6% lying and 5.9+/-6.3% walking) than for those in the ice-free region (12.0+/-15.8 % standing, 0.38+/-0.60% lying and 0 % walking), whereas the proportion of time spent resting at the water surface and porpoising was greater for birds in the ice-free region (38.1+/-6.4% resting and 1.1+/-1.1% porpoising) than for those in the sea-ice region (3.0+/-2.3% resting and 0% porpoising; means +/- s.d., N=7 for the sea-ice region, N=4 for the ice-free region). Using this new approach, further studies combining the monitoring of marine resources in different Antarctic sites and the measurement of the energy expenditure of foraging penguins, e.g. using heart rates, will constitute a powerful tool for investigating the effects of environmental conditions on their foraging strategy. This technique will expand our ability to monitor many animals in the field.


Assuntos
Comportamento Animal , Aves/fisiologia , Locomoção , Animais , Coleta de Dados/métodos , Fatores de Tempo
11.
J Biosci Bioeng ; 91(1): 1-11, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-16232937

RESUMO

Eukaryotic cells have developed a complex intracellular membrane system to divide the cell into various compartments where specific biochemical reactions are efficiently conducted locally. They also have developed systems to deliver appropriate materials to each specific compartment. Vesicular transport is a delivery system that also links most of the main organelles in the cell. The Golgi apparatus occupies the central position of the traffic between the endoplasmic reticulum and the endosome/vacuole/plasma membrane by maturating and sorting delivery of materials. Every important feature of vesicular transport has been identified by studying the Golgi apparatus, and the unicellular microorganism Saccharomyces cerevisiae has been an extremely excellent material for this study. Cycles of production and consumption of the transport vesicles by sorting the cargo, budding from the donor, tethering, docking and fusion to the target can now be explained to a large extent at the molecular level. The functional and structural aspects of the Golgi have also been well studied in the last decade.

12.
Biosci Biotechnol Biochem ; 65(10): 2226-32, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11758914

RESUMO

A novel membrane protein, Yml067c in the systematic ORF name, was discovered as a component of immunoisolated vesicles of the early Golgi compartment of the yeast Saccharomyces cerevisiae (Cho et al., FEBS Lett. 469, 151-154 (2000)). Conserved sequences having sequence similarity to Yml067c were widely distributed in the eukaryotes and one of them, Yal042w, was found in the Saccharomyces genome database. In the yeast cell, Yml067c and Yal042w were found to form a heterooligomeric complex by immunoprecipitation of their tagged derivatives from the detergent-solubilized membrane. Cell fractionation and indirect immunofluorescent staining indicated that the majority of these proteins were localized on the ER membrane. Therefore, the Yml067c-Yal042w complex should shuttle between the ER and the early Golgi compartment as well as the p24-family proteins.


Assuntos
Retículo Endoplasmático/química , Proteínas Fúngicas/isolamento & purificação , Complexo de Golgi/química , Proteínas de Membrana/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/isolamento & purificação , Saccharomyces cerevisiae/química , Sequência de Aminoácidos , Southern Blotting , Western Blotting , Retículo Endoplasmático/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Complexo de Golgi/metabolismo , Membranas Intracelulares/química , Membranas Intracelulares/metabolismo , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Microscopia de Fluorescência , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Testes de Precipitina , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Homologia de Sequência de Aminoácidos , Frações Subcelulares/química , Propriedades de Superfície
13.
Biosci Biotechnol Biochem ; 65(11): 2577-80, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11791739

RESUMO

A previously uncharacterized yeast protein, YJL066c, was discovered in the membrane fraction although it has no hydrophobic stretch. The protein was partly solubilized by Triton X-100 in an oligomeric form, while it was insoluble in alkali or salt. By immunofluorescent microscopy, its localization coincided with the mitochondria. We therefore propose it should be named Mpm1 (mitochondrial peculiar membrane protein 1).


Assuntos
Proteínas Mitocondriais/isolamento & purificação , Proteínas de Saccharomyces cerevisiae/isolamento & purificação , Saccharomyces cerevisiae/metabolismo , Sequência de Aminoácidos , Sequência de Bases , DNA Fúngico/genética , Imuno-Histoquímica , Mitocôndrias/metabolismo , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Dados de Sequência Molecular , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Solubilidade
14.
Hum Mol Genet ; 9(19): 2919-26, 2000 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-11092768

RESUMO

Centromere and kinetochore proteins have a pivotal role in centromere structure, kinetochore formation and sister chromatid separation. However, the molecular architecture and the precise dynamic function of the centromere-kinetochore complex during mitosis remain poorly understood. Here we report the isolation and characterization of human CENP-H. Confocal microscopic analyses of HeLa cells with anti-human CENP-H-specific antibody demonstrated that CENP-H colocalizes with inner kinetochore plate proteins CENP-A and CENP-C in both interphase and metaphase. CENP-H was present outside centromeric heterochromatin, where CENP-B is localized, and inside the kinetochore corona, where CENP-E is localized during prometaphase. Furthermore, CENP-H was detected at neocentromeres, but not at inactive centromeres in stable dicentric chromosomes. In vitro binding assays of human CENP-H with centromere-kinetochore proteins suggest that the CENP-H binds to itself and MCAK, but not to CENP-A, CENP-B or CENP-C. CENP-H multimers were observed in cells in which both FLAG-tagged CENP-H and hemagglutinin-tagged CENP-H were expressed. These results suggest that CENP-H multimers localize constitutively to the inner kinetochore plate and play an important fundamental role in organization and function of the active human centromere-kinetochore complex.


Assuntos
Autoantígenos , Centrômero/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Cinetocoros/metabolismo , Sequência de Aminoácidos , Proteína Centromérica A , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , Clonagem Molecular , Imunofluorescência , Células HeLa , Humanos , Hibridização in Situ Fluorescente , Substâncias Macromoleculares , Microscopia de Fluorescência , Mitose , Dados de Sequência Molecular , Ligação Proteica , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência
15.
Biosci Biotechnol Biochem ; 64(9): 1937-41, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11055399

RESUMO

The Saccharomyces cerevisiae VIG9 gene encodes GDP-mannose pyrophosphorylase, which synthesizes GDP-mannose from GTP and mannose-1-phosphate. Although the null mutant was lethal, the vig9 mutants so far obtained showed no growth defect but immature protein glycosylation and drug hypersensitivity. During our search for cell-wall mutants, we found a novel temperature-sensitive mutant, JS30, which required an osmotic stabilizer for viability. JS30 excreted cell surface proteins in the medium without any indication of cell lysis. Although conventional genetic analysis using mating was impossible, by detailed characterization of JS30 including an in vitro enzyme assay and nucleotide sequencing, we found the defect of JS30 was due to a mutation in the VIG9 gene. These results indicated a critical role of GDP-mannose in maintenance of cell-wall integrity.


Assuntos
Nucleotidiltransferases/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/ultraestrutura , Parede Celular/genética , Parede Celular/ultraestrutura , Escherichia coli/genética , Deleção de Genes , Cinética , Proteínas de Membrana/metabolismo , Mutação , Nucleotidiltransferases/química , Nucleotidiltransferases/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/enzimologia , Especificidade por Substrato
16.
Proc Natl Acad Sci U S A ; 97(13): 7266-71, 2000 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-10840064

RESUMO

Centromere protein A (CENP-A) is a variant of histone H3 with more than 60% sequence identity at the C-terminal histone fold domain. CENP-A specifically locates to active centromeres of animal chromosomes and therefore is believed to be a component of the specialized centromeric nucleosomes on which the kinetochores are assembled. Here we report that CENP-A, highly purified from HeLa cells, can indeed replace histone H3 in a nucleosome reconstitution system mediated by nucleosome assembly protein-1 (NAP-1). The structure of the nucleosomes reconstituted with recombinant CENP-A, histones H2A, H2B, and H4, and closed circular DNAs had the following properties. By atomic force microscopy, "beads on a string" images were obtained that were similar to those obtained with nucleosomes reconstituted with four standard histones. DNA ladders with repeats of approximately 10 bp were produced by DNase I digestion, indicating that the DNA was wrapped round the protein complex. Mononucleosomes isolated by glycerol gradient sedimentation had a relative molecular mass of approximately 200 kDa and were composed of 120-150 bp of DNA and equimolar amounts of CENP-A, and histones H4, H2A, and H2B. Thus, we conclude that CENP-A forms an octameric complex with histones H4, H2A, and H2B in the presence of DNA.


Assuntos
Autoantígenos , Proteínas Cromossômicas não Histona/metabolismo , Histonas/metabolismo , Nucleossomos/metabolismo , Proteína Centromérica A , Proteínas Cromossômicas não Histona/química , Proteínas Cromossômicas não Histona/genética , Células HeLa , Histonas/química , Histonas/genética , Humanos , Nucleossomos/genética , Ligação Proteica , Dobramento de Proteína , Homologia de Sequência de Aminoácidos
17.
Med Phys ; 27(4): 712-5, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10798693

RESUMO

A method for designing a variable-SOBP (spread-out Bragg peak) ridge filter has been proposed. First, ridge filter parameters are determined by using a Monte Carlo calculation followed by a fast two-step iterative optimization. Then, tilting the ridge filter results in continuous variation of the SOBP width. Monte Carlo calculations show that depth dose uniformity changes from +/- 1.3% to +/- 1.6% for SOBP widths ranging from 10.3 cm to 14.5 cm. Advantages of the proposed tilting ridge filter include a capability of continuous SOBP variation and cost-effective installation for a given SOBP width range.


Assuntos
Planejamento da Radioterapia Assistida por Computador/métodos , Algoritmos , Método de Monte Carlo , Radioterapia/economia , Radioterapia/instrumentação , Radioterapia/métodos , Reprodutibilidade dos Testes
18.
Biosci Biotechnol Biochem ; 64(1): 142-8, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10705459

RESUMO

A novel Kluyveromyces marxianus gene that encodes an acid phosphatase, Pho610, was cloned in Saccharomyces cerevisiae. The deduced amino acid sequence was distinct from S. cerevisiae phosphatases but similar to some fungal enzymes. A peculiar feature of the sequence is that it has hydrophobic stretches both at the N- and C-termini, which is a characteristic of the precursors of glycosylphosphatidylinositol(GPI)-anchored proteins. When the gene was expressed in S. cerevisiae, the active enzyme was recovered in the periplasmic fraction by glucanase digestion. The Pho610 polypeptide was highly glycosylated and a significant portion was covalently linked to the cell-wall glucan. The enzyme was secreted when the C-terminal region was truncated to remove the GPI signal. Therefore, Pho610 is a novel cell-wall protein having an enzyme activity.


Assuntos
Fosfatase Ácida/genética , Kluyveromyces/enzimologia , Fosfatase Ácida/química , Sequência de Aminoácidos , Sequência de Bases , Parede Celular/enzimologia , Clonagem Molecular , Glucana Endo-1,3-beta-D-Glucosidase/metabolismo , Glicosilação , Hexosaminidases/metabolismo , Dados de Sequência Molecular , Saccharomyces cerevisiae/enzimologia
19.
FEBS Lett ; 469(2-3): 151-4, 2000 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-10713261

RESUMO

The yeast tSNARE Sed5p is considered to mainly reside in the early Golgi compartment at the steady state of its intracellular cycling. To better understand this compartment, we immunoisolated a membrane subfraction having Sed5p on the surface (the Sed5 vesicles). Immunoblot studies showed that considerable portions (20-30%) of the Golgi mannosyltransferases (Mnt1p, Van1p, and Mnn9p) were simultaneously recovered while the late Golgi (Kex2p) or endoplasmic reticulum (Sec71p) proteins were almost excluded. The N-terminal sequences of the polypeptides detectable by Coomassie blue staining indicated that the prominent components of the Sed5 vesicles include Anp1p, Emp24p, Erv25p, Erp1p, Ypt52p, and a putative membrane protein of unknown function (Yml067c).


Assuntos
Proteínas Fúngicas/metabolismo , Complexo de Golgi/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular , Proteínas rab5 de Ligação ao GTP , Proteínas de Transporte/análise , Proteínas de Transporte/metabolismo , Eletroforese em Gel de Poliacrilamida , Proteínas Fúngicas/análise , Immunoblotting , Manosiltransferases/análise , Manosiltransferases/metabolismo , Proteínas de Membrana/análise , Proteínas Qa-SNARE , Saccharomyces cerevisiae/ultraestrutura , Análise de Sequência de Proteína , Proteínas rab de Ligação ao GTP/análise , Proteínas rab de Ligação ao GTP/metabolismo
20.
Arch Otolaryngol Head Neck Surg ; 126(2): 185-93, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10680870

RESUMO

OBJECTIVE: To identify distinct clinical features of pharyngotonsillitis or oropharyngitis associated with Epstein-Barr virus (EBV) infection from herpes simplex virus infection. DESIGN: Clinical studies by case exploration. SETTING: Institutional practice at a university hospital. PATIENTS: Thirty-three patients with pharyngotonsillitis and 4 patients with oropharyngitis of nonbacterial infection underwent biopsy of pharyngotonsillar lesions. MAIN OUTCOME MEASURE: The specimens were examined by histopathology, immunohistochemistry, in situ hybridization, and polymerase chain reaction. In addition to serological testing and routine laboratory data, photographic oropharyngeal findings were collected for clinical evaluation. RESULTS: In situ hybridization to detect EBV-encoded small nuclear RNA-1 and -2 disclosed 8 cases of pharyngotonsillitis and 4 cases of oropharyngitis associated with EBV infection. Immunohistochemical analysis identified 5 cases of pharyngotonsillitis associated with herpes simplex virus infection. Serological examination showed that, among 12 cases positive by in situ hybridization, 3 cases were primary infection with infectious mononucleosis and 9 were nonprimary infection. The staining pattern of in situ hybridization was different, ie, a linear pattern in cases of nonprimary infection and a scattered pattern in cases of primary infection. The clinical manifestations of EBV pharyngotonsillitis were distinct from those of herpes simplex virus pharyngotonsillitis and were characteristic irrespective of infectious status, while those of EBV oropharyngitis were more variable. CONCLUSIONS: Epstein-Barr virus-associated pharyngotonsillitis was demonstrated in patients with nonprimary infection unaccompanied by infectious mononucleosis. Epstein-Barr virus should be considered a potential causative agent of oropharyngotonsillitis even in absence of infectious mononucleosis, especially in a young adult.


Assuntos
Infecções por Vírus Epstein-Barr/diagnóstico , Faringite/virologia , Tonsilite/virologia , Doença Aguda , Adolescente , Adulto , Anticorpos Antivirais/análise , Antígenos Virais/análise , Biópsia por Agulha , Diagnóstico Diferencial , Feminino , Herpes Simples/diagnóstico , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/isolamento & purificação , Humanos , Imuno-Histoquímica , Hibridização In Situ , Mononucleose Infecciosa/diagnóstico , Masculino , Pessoa de Meia-Idade , Orofaringe/patologia , Faringite/diagnóstico , Faringite/patologia , Reação em Cadeia da Polimerase , Tonsilite/diagnóstico , Tonsilite/patologia
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