Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Photosynth Res ; 156(2): 217-229, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36862281

RESUMO

Carbonic anhydrase (CA) is a crucial component for the operation of CO2-concentrating mechanisms (CCMs) in the majority of aquatic photoautotrophs that maintain the global primary production. In the genome of the centric marine diatom, Thalassiosira pseudonana, there are four putative gene sequences that encode θ-type CA, which was a type of CA recently identified in marine diatoms and green algae. In the present study, specific subcellular locations of four θCAs, TpθCA1, TpθCA2, TpθCA3, and TpθCA4 were determined by expressing GFP-fused proteins of these TpθCAs in T. pseudonana. As a result, C-terminal GFP fusion proteins of TpθCA1, TpθCA2, and TpθCA3 were all localized in the chloroplast; TpθCA2 was at the central chloroplast area, and the other two TpθCAs were throughout the chloroplast. Immunogold-labeling transmission electron microscopy was further performed for the transformants expressing TpθCA1:GFP and TpθCA2:GFP with anti-GFP-monoclonal antibody. TpθCA1:GFP was localized in the free stroma area, including the peripheral pyrenoid area. TpθCA2:GFP was clearly located as a lined distribution at the central part of the pyrenoid structure, which was most likely the pyrenoid-penetrating thylakoid. Considering the presence of the sequence encoding the N-terminal thylakoid-targeting domain in the TpθCA2 gene, this localization was likely the lumen of the pyrenoid-penetrating thylakoid. On the other hand, TpθCA4:GFP was localized in the cytoplasm. Transcript analysis of these TpθCAs revealed that TpθCA2 and TpθCA3 were upregulated in atmospheric CO2 (0.04% CO2, LC) levels, while TpθCA1 and TpθCA4 were highly induced under 1% CO2 (HC) condition. The genome-editing knockout (KO) of TpθCA1, by CRISPR/Cas9 nickase, gave a silent phenotype in T. pseudonana under LC-HC conditions, which was in sharp agreement with the case of the previously reported TpθCA3 KO. In sharp contrast, TpθCA2 KO is so far unsuccessful, suggesting a housekeeping role of TpθCA2. The silent phenotype of KO strains of stromal CAs suggests that TpαCA1, TpθCA1, and TpθCA3 may have functional redundancy, but different transcript regulations in response to CO2 of these stromal CAs suggest in part their independent roles.


Assuntos
Anidrases Carbônicas , Diatomáceas , Diatomáceas/genética , Diatomáceas/metabolismo , Anidrases Carbônicas/genética , Anidrases Carbônicas/metabolismo , Dióxido de Carbono/metabolismo , Cloroplastos/metabolismo , Proteínas/metabolismo
2.
Health Econ ; 30(6): 1480-1497, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33819359

RESUMO

While increasing attention is given to how health reductions affect workers, estimating their effects is usually challenging. This paper aims to identify the causal effect of health deterioration on labor market outcomes by exploiting the incidence of stroke. Stroke, which often reduces health suddenly and unexpectedly, allows us to exploit the within-person random variation of the timing and isolate the effects of health reduction. By applying the fixed-effects method to a sample of stroke survivors in the University of Michigan Health and Retirement Study data, I find that stroke immediately halves the employment probability as well as hours and weeks worked 1 year after the occurrence and its effects persist for at least 3 years, while earnings reduction is relatively moderate and gradual. I also find the negative effects of stroke are larger among men with severe stroke and women with longer pre-stroke job tenure, while the effects are mitigated for younger women. These results make a stark contrast with the studies on other health events such as cancer diagnosis, which generally find much smaller effects and significant heterogeneity by education and occupation. This analysis shows that the labor market effects largely differ by types of diseases and calls for disease-specific studies in order to understand the social gradient in health and how workers adjust to work limitations.


Assuntos
Aposentadoria , Acidente Vascular Cerebral , Emprego , Feminino , Humanos , Incidência , Masculino , Ocupações , Acidente Vascular Cerebral/epidemiologia
3.
Nature ; 524(7565): 366-9, 2015 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-26168400

RESUMO

Diatoms are one of the most ecologically successful classes of photosynthetic marine eukaryotes in the contemporary oceans. Over the past 30 million years, they have helped to moderate Earth's climate by absorbing carbon dioxide from the atmosphere, sequestering it via the biological carbon pump and ultimately burying organic carbon in the lithosphere. The proportion of planetary primary production by diatoms in the modern oceans is roughly equivalent to that of terrestrial rainforests. In photosynthesis, the efficient conversion of carbon dioxide into organic matter requires a tight control of the ATP/NADPH ratio which, in other photosynthetic organisms, relies principally on a range of plastid-localized ATP generating processes. Here we show that diatoms regulate ATP/NADPH through extensive energetic exchanges between plastids and mitochondria. This interaction comprises the re-routing of reducing power generated in the plastid towards mitochondria and the import of mitochondrial ATP into the plastid, and is mandatory for optimized carbon fixation and growth. We propose that the process may have contributed to the ecological success of diatoms in the ocean.


Assuntos
Organismos Aquáticos/metabolismo , Dióxido de Carbono/metabolismo , Diatomáceas/citologia , Diatomáceas/metabolismo , Mitocôndrias/metabolismo , Fotossíntese , Plastídeos/metabolismo , Força Próton-Motriz , Trifosfato de Adenosina/metabolismo , Organismos Aquáticos/citologia , Organismos Aquáticos/enzimologia , Organismos Aquáticos/genética , Ciclo do Carbono , Diatomáceas/enzimologia , Diatomáceas/genética , Ecossistema , Proteínas Mitocondriais/deficiência , Proteínas Mitocondriais/metabolismo , NADP/metabolismo , Oceanos e Mares , Oxirredução , Oxirredutases/deficiência , Oxirredutases/metabolismo , Fenótipo , Proteínas de Plantas/metabolismo
4.
J Phycol ; 57(2): 416-434, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33098679

RESUMO

The brown alga Scytosiphon lomentaria (Scytosiphonaceae, Ectocarpales) has been reported from cold and warm waters worldwide. Although previous molecular phylogenetic studies and crossing experiments have shown that it is a complex of multiple distinct species, the taxonomic position and accurate distribution of each species have remained largely unclear. For the S. lomentaria complex from Japan, our cox1 and rbcL phylogenetic analyses detected six species. In addition to five previously detected species (species Ia-Va), one species (species VI) was newly found in the subtropical area, Okinawa Island. Species VI was recovered as a sister to species Ia-Va in rbcL. Based on the morphological and phylogenetic data, we concluded that species Ia is S. lomentaria, species IIIa is S. promiscuus, and the other four species are newly described: S. shibazakiorum for species IIa, S. tosaensis for species IVa, S. arcanus for species Va, and S. subtropicus for species VI. The cox1-based analysis also showed that S. lomentaria, S. shibazakiorum, and S. promiscuus have worldwide distributions, while the other three species were not found outside of Japan. In Japan, except for S. subtropicus, distributions of these species overlapped. Our crossing experiments showed that gametic incompatibility (pre-zygotic barrier) was less developed between the allopatric species (i.e., S. subtropicus and others) compared with the sympatric species. It may suggest that pre-zygotic barriers have evolved among the sympatric species due to reinforcement.


Assuntos
Phaeophyceae , Japão , Filogenia , Zigoto
5.
J Phycol ; 53(2): 333-341, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27885652

RESUMO

Despite the high number of studies on the fine structure of brown algal cells, only limited information is available on the intercelluar transportation of molecules via plasmodesmata in brown algae. In this study, plasmodesmatal permeability of Halopteris congesta was examined by observing the translocation of microinjected fluorescent tracers of different molecular sizes. The tip region of H. congesta consists of a cylindrical apical cell, while the basal region is multiseriate. Fluorescein isothiocyanate-dextran (FD; 3, 10, and 20 kDa) and recombinant green fluorescent protein (27 kDa) were injected into the apical cell and were observed to diffuse into the neighboring cells. FD of 40 kDa was detected only in the injected apical cell. The plasmodesmatal size exclusion limit was considered to be more than 20 kDa and less than 40 kDa. The extent of translocation of 3 and 10 kDa FD from the apical to neighboring cells 2 h postinjection was estimated based on the fluorescence intensity. It was suggested that the diffusing capacity of plasmodesmata varied according to molecular size. In order to examine acropetal and/or basipetal direction of molecular movement, 3 and 10 kDa FD were injected into the third cell from the apical cell. Successive observations indicated that the diffusion of fluorescence in the acropetal direction took longer than that in the basipetal direction. No ultrastructural difference in plasmodesmata was noted among the cross walls.


Assuntos
Phaeophyceae/metabolismo , Plasmodesmos/metabolismo , Transporte Biológico/genética , Transporte Biológico/fisiologia , Comunicação Celular/fisiologia , Dextranos , Fluoresceína-5-Isotiocianato/análogos & derivados , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo
6.
Ther Drug Monit ; 38(6): 663-669, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27661398

RESUMO

BACKGROUND: Everolimus has been used for the treatment of unresectable or metastatic renal cell carcinoma (RCC). Here, we measured blood concentrations of everolimus to obtain the population pharmacokinetic parameters and to examine the relationship between blood concentration and clinical outcomes. METHODS: Twenty-two Japanese patients were enrolled. Blood samples were collected before and 2, 4, 8, and 24 hours after drug administration on days 1 and 8 of everolimus therapy (5 or 10 mg) from inpatients; occasional samples were collected from outpatients. Blood concentrations of everolimus were measured by high-performance liquid chromatography with tandem mass spectrometry. Population pharmacokinetic analysis was conducted using the NONMEM software. RESULTS: Everolimus pharmacokinetics was best described by a 2-compartment model with population mean estimates of apparent oral clearance of 10.0 L/h and an interindividual variability of 42.4%. There was no relationship between overall best responses and the predicted trough concentrations at day 8. The predicted trough concentration in patients who terminated everolimus treatment owing to adverse drug reactions (ADRs) was significantly higher than in patients who stopped the treatment owing to disease progression or other reasons (27.6 ± 3.1 versus 15.7 ± 2.3 ng/mL; mean ± SEM). Patients who terminated the treatment owing to ADRs had significantly shorter time-to-treatment failure than other patients (112 versus 187 days, median). CONCLUSIONS: This study reports the first population pharmacokinetic parameters of everolimus in patients with RCC. Individual dose adjustment based on everolimus blood concentrations helps to avoid early drug cessation due to ADRs.


Assuntos
Antineoplásicos/sangue , Antineoplásicos/farmacocinética , Carcinoma de Células Renais/sangue , Everolimo/sangue , Everolimo/farmacocinética , Neoplasias Renais/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/tratamento farmacológico , Cromatografia Líquida de Alta Pressão/métodos , Relação Dose-Resposta a Droga , Everolimo/administração & dosagem , Feminino , Humanos , Neoplasias Renais/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Espectrometria de Massas em Tandem/métodos , Adulto Jovem
7.
Eur J Clin Pharmacol ; 72(6): 703-10, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26905999

RESUMO

PURPOSE: Docetaxel is frequently used in the treatment of a wide variety of solid tumors, including breast cancer. The aim of this study is to obtain the population pharmacokinetic parameters of docetaxel in Japanese female patients with breast cancer. METHODS: Blood samples from 24 patients were collected sequentially before and after docetaxel infusion. Genomic DNA was isolated from the peripheral blood and genotyped for the selected polymorphisms in the candidate genes of drug transporters and metabolizing enzymes. The influence of patient characteristics on the pharmacokinetics of docetaxel was evaluated using the nonlinear-mixed-effect modeling program, NONMEM. As a basis for comparison, the pharmacokinetics of another taxane paclitaxel in 41 separate female patients with breast cancer was calculated. RESULTS: A two-compartment model adequately described the pharmacokinetic profiles of docetaxel. The population mean estimates of the total body clearance for patients aged 58 years or less and the central volume of distribution for docetaxel were 32.6 L/h and 5.77 L, respectively. In patients over 58 years, the clearance was 24 % higher than that in the younger patients. No influences of the genotypes examined were noted on the clearance of docetaxel. The clearance of paclitaxel was not affected by patient age. CONCLUSIONS: Patients over the age of 58 years showed significantly higher clearance of docetaxel than that in patients aged 58 years or less. Since the clearance of paclitaxel was not affected by the age, it is possible that the pharmacokinetic mechanisms of docetaxel might be specifically affected by age in females.


Assuntos
Envelhecimento/fisiologia , Antineoplásicos Fitogênicos/farmacocinética , Neoplasias da Mama/metabolismo , Modelos Biológicos , Taxoides/farmacocinética , Adulto , Idoso , Antineoplásicos Fitogênicos/sangue , Antineoplásicos Fitogênicos/uso terapêutico , Povo Asiático , Neoplasias da Mama/tratamento farmacológico , Docetaxel , Feminino , Humanos , Pessoa de Meia-Idade , Taxoides/sangue , Taxoides/uso terapêutico
8.
Proc Natl Acad Sci U S A ; 110(5): 1767-72, 2013 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-23297242

RESUMO

Photosynthesis in marine diatoms is a vital fraction of global primary production empowered by CO(2)-concentrating mechanisms. Acquisition of HCO(3)(-) from seawater is a critical primary step of the CO(2)-concentrating mechanism, allowing marine photoautotrophic eukaryotes to overcome CO(2) limitation in alkaline high-salinity water. However, little is known about molecular mechanisms governing this process. Here, we show the importance of a plasma membrane-type HCO(3)(-) transporter for CO(2) acquisition in a marine diatom. Ten putative solute carrier (SLC) family HCO(3)(-) transporter genes were found in the genome of the marine pennate diatom Phaeodactylum tricornutum. Homologs also exist in marine centric species, Thalassiosira pseudonana, suggesting a general occurrence of SLC transporters in marine diatoms. Seven genes were found to encode putative mammalian-type SLC4 family transporters in P. tricornutum, and three of seven genes were specifically transcribed under low CO(2) conditions. One of these gene products, PtSLC4-2, was localized at the plasmalemma and significantly stimulated both dissolved inorganic carbon (DIC) uptake and photosynthesis in P. tricornutum. DIC uptake by PtSLC4-2 was efficiently inhibited by an anion-exchanger inhibitor, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, in a concentration-dependent manner and highly dependent on Na(+) ions at concentrations over 100 mM. These results show that DIC influx into marine diatoms is directly driven at the plasmalemma by a specific HCO(3)(-) transporter with a significant halophilic nature.


Assuntos
Bicarbonatos/metabolismo , Diatomáceas/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Água do Mar/química , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , Sequência de Aminoácidos , Transporte Biológico/efeitos dos fármacos , Carbono/metabolismo , Dióxido de Carbono/metabolismo , Membrana Celular/metabolismo , Diatomáceas/genética , Diatomáceas/fisiologia , Relação Dose-Resposta a Droga , Expressão Gênica , Cinética , Proteínas de Membrana Transportadoras/classificação , Proteínas de Membrana Transportadoras/genética , Microscopia Confocal , Modelos Biológicos , Dados de Sequência Molecular , Fotossíntese/efeitos dos fármacos , Filogenia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
9.
J Stroke Cerebrovasc Dis ; 25(1): 57-62, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26409716

RESUMO

BACKGROUND: Malnutrition affects the activities of daily living (ADLs) in convalescent patients with cerebrovascular disorders. We investigated the relationship between nutritional improvement, energy intake at admission, and recovery of ADLs. METHODS: We evaluated 67 patients with cerebrovascular disorders admitted to our rehabilitation hospital between April 2013 and April 2015. These patients received interventions from the rehabilitation nutritional support team according to the following criteria: weight loss of 2 kg or more and body mass index of 19 kg/m(2) or lower. Exclusion criteria included a body mass index of 25 kg/m(2) or higher, duration of intervention of less than 14 days, or transfer to an acute care hospital because of clinical deterioration. We assessed nutritional status using the Geriatric Nutritional Risk Index (GNRI) and ADL using the Functional Independence Measure (FIM) score, FIM gain, and FIM efficiency. RESULTS: The mean age of the patients was 78.7 ± 8.0 years. The numbers of patients in each category of cerebrovascular disorder were 39 with cerebral infarction, 16 with intracerebral hemorrhage, 8 with subarachnoid hemorrhage, and 4 others. Compared with the counterpart group, the group with an improvement in GNRI had a greater gain in FIM (median 17 and 20, respectively; P = .036) and a higher FIM efficiency (.14 and .22, respectively; P = .020). Multivariate stepwise regression analysis showed that an improvement in GNRI, increasing energy intake at admission, and intracerebral hemorrhage were associated independently with greater FIM efficiency. CONCLUSIONS: This study suggested that nutritional improvement and energy intake at admission are associated with recovery of ADL after cerebrovascular disorders.


Assuntos
Transtornos Cerebrovasculares/reabilitação , Ingestão de Energia , Desnutrição/prevenção & controle , Estado Nutricional , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/fisiopatologia , Estudos Transversais , Feminino , Humanos , Japão/epidemiologia , Masculino , Desnutrição/complicações , Apoio Nutricional , Recuperação de Função Fisiológica , Centros de Reabilitação , Estudos Retrospectivos , Magreza/epidemiologia , Redução de Peso
10.
BMC Plant Biol ; 15: 86, 2015 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-25887918

RESUMO

BACKGROUND: Cyclin-dependent kinases (CDKs) are crucial regulators of cell cycle progression in eukaryotes. The diatom CDKA2 was originally assigned to the classical A-type CDKs, but its cell cycle phase-specific transcription at the G2-to-M phase transition is typical for plant-specific B-type CDKs. RESULTS: Here, we report the functional characterization of CDKA2 from the diatom Phaeodactylum tricornutum. Through a yeast two-hybrid library screen, CDKA2 was found to interact with the G2/M-specific CDK scaffolding factor CKS1. Localization of CDKA2 was found to be nuclear in interphase cells, while in cells undergoing cytokinesis, the signal extended to the cell division plane. In addition, overexpression of CDKA2 induced an overall reduction in the cell growth rate. Expression analysis of cell cycle marker genes in the overexpression lines indicates that this growth reduction is primarily due to a prolongation of the mitotic phase. CONCLUSIONS: Our study indicates a role for CDKA2 during cell division in diatoms. The functional characterization of a CDK with clear CDKB properties in a non-green organism questions whether the current definition of B-type CDKs being plant-specific might need revision.


Assuntos
Proteínas de Algas/fisiologia , Quinases Ciclina-Dependentes/fisiologia , Diatomáceas/fisiologia , Mitose , Proteínas de Algas/genética , Sequência de Aminoácidos , Quinases Ciclina-Dependentes/genética , Diatomáceas/enzimologia , Diatomáceas/genética , Regulação da Expressão Gênica , Dados de Sequência Molecular , Filogenia
11.
JACS Au ; 4(4): 1385-1395, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38665671

RESUMO

Brown algae play essential roles ecologically, practically, and evolutionarily because they maintain coastal areas, capture carbon dioxide, and produce valuable chemicals such as therapeutic drugs. To unlock their full potential, understanding the unique molecular biology of brown algae is imperative. Genetic engineering tools that regulate homeostasis in brown algae are essential for determining their biological mechanisms in detail. However, few methodologies have been developed to control gene expression due to the robust structural barriers of brown algae. To address this issue, we designed peptide-based, small interfering RNA (siRNA)-loaded micelles decorated with phenylboronic acid (PBA) ligands. The PBA ligands facilitated the cellular uptake of the micelles into a model brown alga, Ectocarpus siliculosus (E. Siliculosus), through chemical interaction with polysaccharides in the cell wall and biological recognition by boronic acid transporters on the plasma membrane. The micelles, featuring "kill two birds with one stone" ligands, effectively induced gene silencing related to auxin biosynthesis. As a result, the growth of E. siliculosus was temporarily inhibited without persistent genome editing. This study demonstrated the potential for exploring the characteristics of brown algae through a simple yet effective approach and presented a feasible system for delivering siRNA in brown algae.

12.
Mol Biol Rep ; 40(4): 3231-7, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23269620

RESUMO

Genetic analyses have contributed to improvements of economically important traits derived from adipose tissue such as fatty acid composition in beef. Elongation of very long chain fatty acids (ELOVL) genes encode for the enzymes that play an important role in elongation of long-chain fatty acids. In this study, we aimed to discover genetic polymorphisms of ELOVL gene family in cattle populations to develop genetic markers. As a result, five synonymous mutations were detected in the coding regions of the ELOVL1, ELOVL2, ELOVL3 and ELOVL5 genes. In addition, six mutations were identified in promoter region of the ELOVL5. Two of five mutations in the promoter region of ELOVL5 were expected to alter the ELOVL5 expression and influence the economic traits, because of the high synteny of the region which was essential for activation of Elovl5 in mouse. Therefore, we performed association analysis between the genotypes and traits and our result revealed that T allele of g.-110T>C in ELOVL5 gene promoter indicated significantly thinner subcutaneous fat thickness (TT, 2.39 cm; CT, 2.35 cm) than that of C allele (CC, 2.68 cm) in a Japanese Black population. Our results suggest that the g.-110T>C is a useful genetic marker for the breeding in beef cattle.


Assuntos
Acetiltransferases/genética , Estudos de Associação Genética , Gordura Subcutânea/crescimento & desenvolvimento , Animais , Bovinos , Elongases de Ácidos Graxos , Mutação , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas/genética , Sintenia
13.
Microorganisms ; 11(2)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36838362

RESUMO

Linus Pauling, who was awarded the Nobel Prize in Chemistry, suggested that a high dose of vitamin C (l-ascorbic acid) might work as a prevention or treatment for the common cold. Vitamin C therapy was tested in clinical trials, but clear evidence was not found at that time. Although Pauling's proposal has been strongly criticized for a long time, vitamin C therapy has continued to be tested as a treatment for a variety of diseases, including coronavirus infectious disease 2019 (COVID-19). The pathogen of COVID-19, SARS-CoV-2, belongs to the ß-coronavirus lineage, which includes human coronavirus, severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS). This review intends to shed new light on vitamin C antiviral activity that may prevent SARS-CoV-2 infection through the chemical production of nitric oxide (NO). NO is a gaseous free radical that is largely produced by the enzyme NO synthase (NOS) in cells. NO produced by upper epidermal cells contributes to the inactivation of viruses and bacteria contained in air or aerosols. In addition to enzymatic production, NO can be generated by the chemical reduction of inorganic nitrite (NO2-), an alternative mechanism for NO production in living organisms. Dietary vitamin C, largely contained in fruits and vegetables, can reduce the nitrite in saliva to produce NO in the oral cavity when chewing foods. In the stomach, salivary nitrite can also be reduced to NO by vitamin C secreted from the epidermal cells of the stomach. The strong acidic pH of gastric juice facilitates the chemical reduction of salivary nitrite to produce NO. Vitamin C contributes in multiple ways to the host innate immune system as a first-line defense mechanism against pathogens. Highlighting chemical NO production by vitamin C, we suggest that controversies on the therapeutic effects of vitamin C in previous clinical trials may partly be due to less appreciation of the pleiotropic functions of vitamin C as a universal bioreductant.

14.
Arch Oral Biol ; 155: 105797, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37633030

RESUMO

OBJECTIVE: This study aimed to evaluate the role of ruxolitinib in the interferon beta (IFN-ß) mediated osteoblast differentiation using human dental pulp stem cells (hDPSCs). DESIGN: hDPSCs from five deciduous teeth of healthy patients were stimulated by adding human recombinant IFN-ß protein (1 or 2 ng/ml) to the osteogenic differentiation induction medium. Substrate formation was determined using Alizarin Red staining, calcium concentration, and osteoblast marker expression levels. Ruxolitinib was used to inhibit the Janus kinase/signal transducers and activators of transcription (JAK-STAT) pathway. Apoptosis was detected using terminal deoxynucleotidyl nick-end labeling (TUNEL) staining, and necroptosis was detected using propidium iodide staining and phosphorylated mixed lineage kinase domain-like protein (pMLKL) expression. RESULTS: In the IFN-ß-treated group, substrate formation was inhibited by a reduction in alkaline phosphatase (ALP) expression in a concentration-dependent manner. Although the proliferation potency was unchanged between the IFN-ß-treated and control groups, the cell number was significantly reduced in the experimental group. TUNEL-positive cell number was not significantly different; however, the protein level of necroptosis markers, interleukin-6 (IL-6) and pMLKL were significantly increased in the substrate formation. Cell number and ALP expression level were improved in the group administered ruxolitinib, a JAK-STAT inhibitor. Additionally, ruxolitinib significantly suppressed IL-6 and pMLKL levels. CONCLUSION: Ruxolitinib interfered with the IFN-ß-mediated necroptosis and osteogenic differentiation via the JAK-STAT pathway.

15.
Carbohydr Res ; 523: 108722, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36459703

RESUMO

Brown algae contain a polysaccharide-rich cell wall, mainly composed of alginate and fucoidan which have been extensively studied for their individual structure and bioactivities. Particularly, the cell wall of Cladosiphon okamuranus is rich in fucoidan rather than alginate. However, little is known about its arrangement or interlinking with other polysaccharides such as cellulose in the cell wall. To determine its structure in detail, the cell wall was sequentially fractionated into five fractions: hot water (HW), ammonium oxalate, hemicellulose-I (HC-I), HC-II, and cellulose. Almost 80% of the total cell wall recovered from alcohol insoluble residue in C. okamuranus consisted of HW and HC-I, which mainly contained fucoidan composed of fucose, glucuronic acid, and sulfate in molar ratios of 1.0:0.3:0.9 and 1.0:0.2:0.3, respectively. Methylation analysis revealed that fucoidan in HW and HC-I structurally differed in terms of content of sulfate, and sugar residue which was 1,4-linked xylose and 1,4-linked fucose. Small angle X-ray scattering measurements also showed distinct conformational differences between HW and HC-I. These structural heterogeneities of fucoidan may be related to their localization, and fucoidan in HC-I may be involved in reinforcing cell wall structure by cross-linking to cellulose.


Assuntos
Fucose , Phaeophyceae , Phaeophyceae/química , Polissacarídeos/química , Celulose , Alginatos , Parede Celular , Sulfatos
16.
Plants (Basel) ; 12(18)2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37765437

RESUMO

The present study provides new insights into the growth of the brown algal cell wall by showing that cell wall polysaccharides play an important role in the process of growth, considering the physicochemical characteristic of young and old Cladosiphon okamuranus. To determine its structural variation in detail, the cell wall was sequentially fractionated into five fractions: hot water (HW), ammonium oxalate, hemicellulose-I (HC-I), HC-II, and cellulose, and analyzed physicochemically. Results showed that almost 80% of the total recovery cell wall from both young and old thalli was HW, and HC-I contained mainly fucoidan composed of Fucose, Glucuronic acid, and sulfate in molar ratios of 1.0:0.3:0.6~0.7 and 1.0:0.3:0.2~0.3, respectively. Fucoidan in HW was a highly sulfated matrix polysaccharide abundance in young thalli, while fucoidan in HC-I was rich in old thalli and functions as hemicellulose in land plants, crosslinking with cellulose and strengthening the cell wall. We found that HW and HC-I were particularly involved in the growth and strength of old thalli appeared to be due to the deposition of HC-I and the reduction in water content during the growth process.

17.
JAMA Netw Open ; 6(2): e230589, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36826818

RESUMO

Importance: There have been few studies on the heterogeneous interconnection of COVID-19 outbreaks occurring in different social settings using robust, surveillance epidemiological data. Objectives: To describe the characteristics of COVID-19 transmission within different social settings and to evaluate settings associated with onward transmission to other settings. Design, Setting, and Participants: This is a case series study of laboratory-confirmed COVID-19 cases in Tokyo between January 23 and December 5, 2020, when vaccination was not yet implemented. Using epidemiological investigation data collected by public health centers, epidemiological links were identified and classified into 7 transmission settings: imported, nightlife, dining, workplace, household, health care, and other. Main Outcomes and Measures: The number of cases per setting and the likelihood of generating onward transmissions were compared between different transmission settings. Results: Of the 44 054 confirmed COVID-19 cases in this study, 25 241 (57.3%) were among male patients, and the median (IQR) age of patients was 36 (26-52) years. Transmission settings were identified in 13 122 cases, including 6768 household, 2733 health care, and 1174 nightlife cases. More than 6600 transmission settings were detected, and nightlife (72 of 380 [18.9%]; P < .001) and health care (119 [36.2%]; P < .001) settings were more likely to involve 5 or more cases than dining, workplace, household, and other settings. Nightlife cases appeared in the earlier phase of the epidemic, while household and health care cases appeared later. After adjustment for transmission setting, sex, age group, presence of symptoms, and wave, household and health care cases were less likely to generate onward transmission compared with nightlife cases (household: adjusted odds ratio, 0.03; 95% CI, 0.02-0.05; health care: adjusted odds ratio, 0.57; 95% CI, 0.41-0.79). Household settings were associated with intergenerational transmission, while nonhousehold settings mainly comprised transmission between the same age group. Among 30 932 cases without identified transmission settings, cases with a history of visiting nightlife establishments were more likely to generate onward transmission to nonhousehold settings (adjusted odds ratio, 5.30 [95% CI, 4.64-6.05]; P < .001) than those without such history. Conclusions and Relevance: In this case series study, COVID-19 cases identified in nightlife settings were associated with a higher likelihood of spreading COVID-19 than household and health care cases. Surveillance and interventions targeting nightlife settings should be prioritized to disrupt COVID-19 transmission, especially in the early stage of an epidemic.


Assuntos
COVID-19 , Humanos , Masculino , Adulto , Pessoa de Meia-Idade , SARS-CoV-2 , Tóquio , Japão , Surtos de Doenças
18.
Am J Respir Cell Mol Biol ; 46(6): 748-56, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22227563

RESUMO

The incidence of idiopathic pulmonary fibrosis (IPF) increases with age. The mechanisms that underlie the age-dependent risk for IPF are unknown. Based on studies that suggest an association of IPF and γherpesvirus infection, we infected young (2-3 mo) and old (≥18 mo) C57BL/6 mice with the murine γherpesvirus 68. Acute murine γherpesvirus 68 infection in aging mice resulted in severe pneumonitis and fibrosis compared with young animals. Progressive clinical deterioration and lung fibrosis in the late chronic phase of infection was observed exclusively in old mice with diminution of tidal volume. Infected aging mice showed higher expression of transforming growth factor-ß during the acute phase of infection. In addition, aging, infected mice showed elevation of proinflammatory cytokines and the fibrocyte recruitment chemokine, CXCL12, in bronchoalveolar lavage. Analyses of lytic virus infection and virus reactivation indicate that old mice were able to control chronic infection and elicit antivirus immune responses. However, old, infected mice showed a significant increase in apoptotic responses determined by in situ terminal deoxynucleotidyl transferase dUTP nick end labeling assay, levels of caspase-3, and expression of the proapoptotitc molecule, Bcl-2 interacting mediator. Apoptosis of type II lung epithelial cells in aging lungs was accompanied by up-regulation of endoplasmic reticulum stress marker, binding immunoglobulin protein, and splicing of X-box-binding protein 1. These results indicate that the aging lung is more susceptible to injury and fibrosis associated with endoplasmic reticulum stress, apoptosis of type II lung epithelial cells, and activation of profibrotic pathways.


Assuntos
Retículo Endoplasmático/metabolismo , Fibrose Pulmonar/metabolismo , Estresse Fisiológico , Animais , Apoptose , Western Blotting , Líquido da Lavagem Broncoalveolar , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase em Tempo Real , Fator de Crescimento Transformador beta/metabolismo
19.
J Exp Bot ; 63(4): 1543-57, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22268145

RESUMO

Diatoms are unicellular, mainly photosynthetic, eukaryotes living within elaborate silicified cell walls and believed to be responsible for around 40% of global primary productivity in the oceans. Their abundance in aquatic ecosystems is such that they have on different occasions been described as the insects, the weeds, or the cancer cells of the ocean. In contrast to higher plants and green algae which derive from a primary endosymbiosis, diatoms are now believed to originate from a serial secondary endosymbiosis involving both green and red algae and a heterotrophic exosymbiont host. As a consequence of their dynamic evolutionary history, they appear to have red algal-derived chloroplasts empowered largely by green algal proteins, working alongside mitochondria derived from the non-photosynthetic exosymbiont. This review will discuss the evidence for such an unusual assemblage of organelles in diatoms, and will present the evidence implying that it has enabled them with unorthodox metabolisms that may have contributed to their profound ecological success.


Assuntos
Cloroplastos/metabolismo , Diatomáceas/metabolismo , Mitocôndrias/metabolismo , Transdução de Sinais/fisiologia
20.
Rinsho Byori ; 60(9): 847-52, 2012 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-23157113

RESUMO

A case of epilepsy associated with ring chromosome 20 [r(20)] syndrome was first reported in 1972. Relatively few cases of [r(20)] syndrome have been reported. We report here a middle-aged female with this syndrome. She had two types of seizures characterized by complex partial seizure with complex motor automatism mainly occurred while asleep and episodes of fluctuating consciousness (non-convulsive status epilepticus) lasting 40-60 min. The ictal electroencephalography (EEG) findings of the latter showed almost continuous diffuse spike and wave complexes or high voltage slow waves. The interictal EEG findings showed spike or sharp waves located in bilateral frontal regions or 3-6Hz diffuse high voltage slow waves intermingled with spikes in left posterior areas. We reviewed and discussed the characteristics of [r(20)] syndrome reported in the literature, intractable seizures, behavioral problems and some degree of mental retardation or dysmorphism, especially variable EEG findings characterized this syndrome.


Assuntos
Cromossomos Humanos Par 20/genética , Epilepsia/genética , Lobo Frontal/fisiopatologia , Cromossomos em Anel , Estado Epiléptico/genética , Adulto , Eletroencefalografia , Feminino , Humanos , Cariótipo , Estado Epiléptico/fisiopatologia , Síndrome
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA