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1.
Proc Natl Acad Sci U S A ; 120(47): e2307773120, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-37963246

RESUMO

The expansion and intensification of livestock production is predicted to promote the emergence of pathogens. As pathogens sometimes jump between species, this can affect the health of humans as well as livestock. Here, we investigate how livestock microbiota can act as a source of these emerging pathogens through analysis of Streptococcus suis, a ubiquitous component of the respiratory microbiota of pigs that is also a major cause of disease on pig farms and an important zoonotic pathogen. Combining molecular dating, phylogeography, and comparative genomic analyses of a large collection of isolates, we find that several pathogenic lineages of S. suis emerged in the 19th and 20th centuries, during an early period of growth in pig farming. These lineages have since spread between countries and continents, mirroring trade in live pigs. They are distinguished by the presence of three genomic islands with putative roles in metabolism and cell adhesion, and an ongoing reduction in genome size, which may reflect their recent shift to a more pathogenic ecology. Reconstructions of the evolutionary histories of these islands reveal constraints on pathogen emergence that could inform control strategies, with pathogenic lineages consistently emerging from one subpopulation of S. suis and acquiring genes through horizontal transfer from other pathogenic lineages. These results shed light on the capacity of the microbiota to rapidly evolve to exploit changes in their host population and suggest that the impact of changes in farming on the pathogenicity and zoonotic potential of S. suis is yet to be fully realized.


Assuntos
Infecções Estreptocócicas , Streptococcus suis , Doenças dos Suínos , Animais , Humanos , Suínos , Infecções Estreptocócicas/veterinária , Fazendas , Doenças dos Suínos/epidemiologia , Virulência/genética , Streptococcus suis/genética , Gado
2.
PLoS Genet ; 17(11): e1009864, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34748531

RESUMO

Mutation rates vary both within and between bacterial species, and understanding what drives this variation is essential for understanding the evolutionary dynamics of bacterial populations. In this study, we investigate two factors that are predicted to influence the mutation rate: ecology and genome size. We conducted mutation accumulation experiments on eight strains of the emerging zoonotic pathogen Streptococcus suis. Natural variation within this species allows us to compare tonsil carriage and invasive disease isolates, from both more and less pathogenic populations, with a wide range of genome sizes. We find that invasive disease isolates have repeatedly evolved mutation rates that are higher than those of closely related carriage isolates, regardless of variation in genome size. Independent of this variation in overall rate, we also observe a stronger bias towards G/C to A/T mutations in isolates from more pathogenic populations, whose genomes tend to be smaller and more AT-rich. Our results suggest that ecology is a stronger correlate of mutation rate than genome size over these timescales, and that transitions to invasive disease are consistently accompanied by rapid increases in mutation rate. These results shed light on the impact that ecology can have on the adaptive potential of bacterial pathogens.


Assuntos
Adaptação Biológica/genética , Doenças Transmissíveis Emergentes/microbiologia , Taxa de Mutação , Infecções Estreptocócicas/microbiologia , Streptococcus suis/genética , Zoonoses/microbiologia , Animais , Ecologia , Streptococcus suis/isolamento & purificação , Streptococcus suis/patogenicidade , Virulência/genética
3.
J Exp Bot ; 74(21): 6860-6873, 2023 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-37696760

RESUMO

MYZUS PERSICAE-INDUCED LIPASE1 (MPL1) encodes a lipase in Arabidopsis thaliana that is required for limiting infestation by the green peach aphid (GPA; Myzus persicae), an important phloem sap-consuming insect pest. Previously, we demonstrated that MPL1 expression was up-regulated in response to GPA infestation, and GPA fecundity was higher on the mpl1 mutant, compared with the wild-type (WT), and lower on 35S:MPL1 plants that constitutively expressed MPL1 from the 35S promoter. Here, we show that the MPL1 promoter is active in the phloem and expression of the MPL1 coding sequence from the phloem-specific SUC2 promoter in mpl1 is sufficient to restore resistance to GPA. The GPA infestation-associated up-regulation of MPL1 requires CYCLOPHILIN 20-3 (CYP20-3), which encodes a 12-oxo-phytodienoic acid (OPDA)-binding protein that is involved in OPDA signaling, and is required for limiting GPA infestation. OPDA promotes MPL1 expression to limit GPA fecundity, a process that requires CYP20-3 function. These results along with our observation that constitutive expression of MPL1 from the 35S promoter restores resistance to GPA in the cyp20-3 mutant, and MPL1 acts in a feedback loop to limit OPDA levels in GPA-infested plants, suggest that an interplay between MPL1, OPDA, and CYP20-3 contributes to resistance to GPA.


Assuntos
Afídeos , Proteínas de Arabidopsis , Arabidopsis , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Lipase/genética , Lipase/metabolismo , Afídeos/fisiologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Hidrolases de Éster Carboxílico/metabolismo , Mutação , Doenças das Plantas , Regulação da Expressão Gênica de Plantas
4.
Arch Insect Biochem Physiol ; 112(3): e21986, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36453553

RESUMO

The present study explores the compatible interaction between Arabidopsis thaliana and Myzus persicae to reduce host resistance from the previous aphid herbivore-mediated priming. The resumption of host resistance from the "reduced host resistance" was also recorded in due time when aphid herbivore was removed from leaf foliage. The vascular sap, isolated from the midpoint timing from the "reduced host resistance" to the "resumed host resistance" phase resolved in gas chromatography-mass spectrometry (GC-MS) analysis that identified an enrichment of dodecanoic acid (DA), an antibacterial metabolite and a saturated medium-chain fatty acid with a 12-carbon backbone. DA infiltration into leaf foliage revealed a significant reduction of aphid clonal proliferation on leaf foliage with concomitant reduction of the vascular microbiota titer as well as aphid body. The "resumed host resistance" from "reduced host resistance" also showed a comparable microbiota titer in comparison to control but the "reduced host resistance" evidenced a significant higher microbiota titer which was correlated with an enhanced aphid clonal proliferation on the leaf foliage. The DA infiltrated leaf foliage had no effect on total vascular sap ingestion by the aphid herbivore but induced RNA level of GUS expression under the control of promoter of pad-4, mpl-1, and sag-13. A similar pattern of gus expression was recorded from aphid herbivore. Thus, DA mediates aphid resistance toward aphid clonal proliferation in the host plant by manipulating vascular and aphid body microbiota titer.


Assuntos
Afídeos , Arabidopsis , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Ácidos Láuricos/metabolismo , Herbivoria
5.
Molecules ; 27(9)2022 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-35566385

RESUMO

Cancer is a disorder that rigorously affects the human population worldwide. There is a steady demand for new remedies to both treat and prevent this life-threatening sickness due to toxicities, drug resistance and therapeutic failures in current conventional therapies. Researchers around the world are drawing their attention towards compounds of natural origin. For decades, human beings have been using the flora of the world as a source of cancer chemotherapeutic agents. Currently, clinically approved anticancer compounds are vincristine, vinblastine, taxanes, and podophyllotoxin, all of which come from natural sources. With the triumph of these compounds that have been developed into staple drug products for most cancer therapies, new technologies are now appearing to search for novel biomolecules with anticancer activities. Ellipticine, camptothecin, combretastatin, curcumin, homoharringtonine and others are plant derived bioactive phytocompounds with potential anticancer properties. Researchers have improved the field further through the use of advanced analytical chemistry and computational tools of analysis. The investigation of new strategies for administration such as nanotechnology may enable the development of the phytocompounds as drug products. These technologies have enhanced the anticancer potential of plant-derived drugs with the aim of site-directed drug delivery, enhanced bioavailability, and reduced toxicity. This review discusses mechanistic insights into anticancer compounds of natural origins and their structural activity relationships that make them targets for anticancer treatments.


Assuntos
Antineoplásicos , Neoplasias , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Humanos , Neoplasias/tratamento farmacológico , Plantas , Podofilotoxina/química , Relação Estrutura-Atividade
6.
Saudi Pharm J ; 30(9): 1360-1371, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36249945

RESUMO

This study intends to evaluate the development, importance, pre-clinical and clinical study evaluation of stem cell therapy for the treatment of cardiovascular disease. Cardiovascular disease is one of the main causes of fatality in the whole world. Though there are great progressions in the pharmacological and other interventional treatment options, heart diseases remain a common disorder that causes long-term warnings. Recent accession promotes the symptoms and slows down the adverse effects regarding cardiac remodelling. But they cannot locate the problems of immutable loss of cardiac tissues. In this case, stem cell treatment holds a promising challenge. Stem cells are the cells that are capable of differentiating into many cells according to their needs. So, it is assumed that these cells can distinguish into many cells and if these cells can be individualized into cardiac cells then they can be used to replace the damaged tissues of the heart. There is some abridgment in this therapy, none the less stem cell therapy remains a hopeful destination in the treatment of heart disease.

7.
Plant Physiol ; 176(1): 879-890, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29133373

RESUMO

The actin cytoskeleton network has an important role in plant cell growth, division, and stress response. Actin-depolymerizing factors (ADFs) are a group of actin-binding proteins that contribute to reorganization of the actin network. Here, we show that the Arabidopsis (Arabidopsis thaliana) ADF3 is required in the phloem for controlling infestation by Myzus persicae Sülzer, commonly known as the green peach aphid (GPA), which is an important phloem sap-consuming pest of more than fifty plant families. In agreement with a role for the actin-depolymerizing function of ADF3 in defense against the GPA, we show that resistance in adf3 was restored by overexpression of the related ADF4 and the actin cytoskeleton destabilizers, cytochalasin D and latrunculin B. Electrical monitoring of the GPA feeding behavior indicates that the GPA stylets found sieve elements faster when feeding on the adf3 mutant compared to the wild-type plant. In addition, once they found the sieve elements, the GPA fed for a more prolonged period from sieve elements of adf3 compared to the wild-type plant. The longer feeding period correlated with an increase in fecundity and population size of the GPA and a parallel reduction in callose deposition in the adf3 mutant. The adf3-conferred susceptibility to GPA was overcome by expression of the ADF3 coding sequence from the phloem-specific SUC2 promoter, thus confirming the importance of ADF3 function in the phloem. We further demonstrate that the ADF3-dependent defense mechanism is linked to the transcriptional up-regulation of PHYTOALEXIN-DEFICIENT4, which is an important regulator of defenses against the GPA.


Assuntos
Fatores de Despolimerização de Actina/metabolismo , Afídeos/fisiologia , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/parasitologia , Comportamento Alimentar , Floema/parasitologia , Citoesqueleto de Actina/metabolismo , Fatores de Despolimerização de Actina/genética , Animais , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Hidrolases de Éster Carboxílico/metabolismo , Resistência à Doença , Genes de Plantas , Mutação/genética , Doenças das Plantas/parasitologia , Folhas de Planta/parasitologia
8.
Lett Appl Microbiol ; 68(5): 423-429, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30659625

RESUMO

The effects and mechanisms of Paenibacillus polymyxa Sx3 on growth promotion and the suppression of bacterial leaf blight in rice were evaluated in this study. The results from a plate assay indicated that Sx3 inhibited the growth of 20 strains of Xanthomonas oryzae pv. oryzae (Xoo). Rice seedling experiments indicated that Sx3 promoted plant growth and suppressed bacterial leaf blight. In addition, bacteriological tests showed that Sx3 was able to fix nitrogen, solubilize phosphate and produce indole acetic acid, indicating that various mechanisms may be involved in the growth promotion by Sx3. The culture filtrate of P. polymyxa Sx3 reduced bacterial growth, biofilm formation and disrupted the cell morphology of Xoo strain GZ 0005, as indicated by the transmission and scanning electron microscopic observations. In addition, MALDI-TOF MS analysis revealed that Sx3 could biosynthesize two types of secondary metabolites fusaricidins and polymyxin P. In summary, this study clearly indicated that P. polymyxa Sx3 has strong in vitro and in vivo antagonistic activity against Xoo, which may be at least partially attributed to its production of secondary metabolites. SIGNIFICANCE AND IMPACT OF THE STUDY: Antagonistic bacteria can grow well in their originating environment. However, it is unclear whether antagonistic bacteria were able to survive in different ecological environments. This study revealed that Paenibacillus polymyxa Sx3 isolated from rhizosphere soil of cotton significantly promoted the plant growth and suppressed bacterial leaf blight in rice. Therefore, it could be inferred that P. polymyxa Sx3 has the potential to be used as biocontrol agents in plants grown in different ecological environments.


Assuntos
Antibiose/fisiologia , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Paenibacillus polymyxa/fisiologia , Doenças das Plantas/microbiologia , Xanthomonas/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Depsipeptídeos/biossíntese , Ácidos Indolacéticos/metabolismo , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Fixação de Nitrogênio/fisiologia , Desenvolvimento Vegetal , Polimixinas/biossíntese , Rizosfera , Plântula/microbiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
9.
Mol Biol Evol ; 34(1): 185-203, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28053012

RESUMO

Viral phylogenetic methods contribute to understanding how HIV spreads in populations, and thereby help guide the design of prevention interventions. So far, most analyses have been applied to well-sampled concentrated HIV-1 epidemics in wealthy countries. To direct the use of phylogenetic tools to where the impact of HIV-1 is greatest, the Phylogenetics And Networks for Generalized HIV Epidemics in Africa (PANGEA-HIV) consortium generates full-genome viral sequences from across sub-Saharan Africa. Analyzing these data presents new challenges, since epidemics are principally driven by heterosexual transmission and a smaller fraction of cases is sampled. Here, we show that viral phylogenetic tools can be adapted and used to estimate epidemiological quantities of central importance to HIV-1 prevention in sub-Saharan Africa. We used a community-wide methods comparison exercise on simulated data, where participants were blinded to the true dynamics they were inferring. Two distinct simulations captured generalized HIV-1 epidemics, before and after a large community-level intervention that reduced infection levels. Five research groups participated. Structured coalescent modeling approaches were most successful: phylogenetic estimates of HIV-1 incidence, incidence reductions, and the proportion of transmissions from individuals in their first 3 months of infection correlated with the true values (Pearson correlation > 90%), with small bias. However, on some simulations, true values were markedly outside reported confidence or credibility intervals. The blinded comparison revealed current limits and strengths in using HIV phylogenetics in challenging settings, provided benchmarks for future methods' development, and supports using the latest generation of phylogenetic tools to advance HIV surveillance and prevention.


Assuntos
Infecções por HIV/epidemiologia , Infecções por HIV/virologia , HIV-1/genética , África Subsaariana/epidemiologia , Simulação por Computador , Epidemias , Feminino , Infecções por HIV/prevenção & controle , Infecções por HIV/transmissão , Humanos , Incidência , Masculino , Filogenia
10.
J Appl Microbiol ; 2018 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-30146698

RESUMO

AIMS: The aim of this study was to evaluate the antagonistic activity of halotolerant bacteria against rice brown stripe pathogen Acidovorax oryzae. METHODS AND RESULTS: Fifteen of 136 isolates of halotolerant bacteria exhibited strong in vitro and in vivo antagonistic activity against both strains of A. oryzae. The 15 antagonistic isolates were identified as 'operational group Bacillus amyloliquefaciens' based on physiological and biochemical features, fatty acid profiles as well as sequence analysis of 16S rRNA, gyrA and rpoB genes. Furthermore, this result indicated that the most effective antagonistic isolates K5-3 and PPB6 could produce siderophore in iron-limiting medium, and four kinds of secondary metabolites based on MALDI-TOF analysis. In addition, the culture filtrates of isolates K5-3 and PPB6 caused the damage of cell membrane evidenced by the TEM images, and resulted in 73-80% reduction in cell numbers, 55-65% reduction in biofilm formation, and 42-50% reduction in swimming ability of both strains of A. oryzae. CONCLUSIONS: These isolates in particular K5-3 and PPB6 of halotolerant bacteria markedly inhibited the growth of A. oryzae. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first report on biological control of halotolerant bacteria against bacterial brown stripe of rice.

11.
BMC Vet Res ; 14(1): 300, 2018 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-30285752

RESUMO

BACKGROUND: Staphylococcus aureus is responsible for large numbers of hospital-related and community-acquired infections. In this study, we investigated the presence of S. aureus and methicillin-resistant S. aureus (MRSA) in 100 samples from animals (55 cattle, 36 dogs, and 9 cats) and 150 samples from hospitalized human patients. The samples were collected from healthy and diseased animals and from diseased humans and included milk, wound swab, pus, exudates, nasal swab and diabetic ulcer. Initially, S. aureus was isolated and identified by colony morphology, Gram staining, and biochemical tests (catalase and coagulase tests). The S. aureus-positive samples were examined by polymerase chain reaction (PCR) to determine their MRSA status. RESULTS: Of the 100 animal samples, 29 were positive for S. aureus. Four samples (13.8%) from dogs were MRSA-positive, but samples from cattle and cats were MRSA-negative. Of the 150 human samples we collected, 64 were S. aureus-positive and, of these, 34 (53.1%) were MRSA-positive. Most (28%) of the MRSA samples were isolated from surgical wound swabs, followed by the pus from skin infections (11%), exudates from diabetic ulcers (6%), exudates from burns (4%), and aural swabs (3%). By contrast, a low MRSA detection rate (n = 4) was seen in the non-human isolates, where all MRSA bacteria were isolated from nasal swabs from dogs. The antimicrobials susceptibility testing results showed that S. aureus isolates with mecA genes showed resistance to penicillin (100%), oxacillin (100%), erythromycin (73.5%), ciprofloxacin (70.6%), and gentamicin (67.7%). The lowest resistance was found against ceftazidime, and no vancomycin-resistant isolates were obtained. CONCLUSIONS: We detected S. aureus and MRSA in both human and canine specimens. Isolates were found to be resistant to some of the antimicrobials available locally. MRSA carriage in humans and animals appears to be a great threat to effective antimicrobials treatment. The prudent use of antimicrobials will reduce the antimicrobial resistance. Our findings will help to find the most appropriate treatment and to reduce antimicrobial resistance in the future by implementing prudent use of antimicrobials. Further studies are required to better understand the epidemiology of MRSA human-animal inter-species transmission in Bangladesh.


Assuntos
Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologia , Animais , Bangladesh , Doenças do Gato/microbiologia , Gatos , Bovinos , Doenças dos Bovinos/microbiologia , Doenças do Cão/microbiologia , Cães , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Leite/microbiologia , Reação em Cadeia da Polimerase Multiplex/veterinária , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/isolamento & purificação
12.
Agric Syst ; 163: 36-44, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29861535

RESUMO

Bangladesh faces huge challenges in achieving food security due to its high population, diet changes, and limited room for expanding cropland and cropping intensity. The objective of this study is to assess the degree to which Bangladesh can be self-sufficient in terms of domestic maize, rice and wheat production by the years 2030 and 2050 by closing the existing gap (Yg) between yield potential (Yp) and actual farm yield (Ya), accounting for possible changes in cropland area. Yield potential and yield gaps were calculated for the three crops using well-validated crop models and site-specific weather, management and soil data, and upscaled to the whole country. We assessed potential grain production in the years 2030 and 2050 for six land use change scenarios (general decrease in arable land; declining ground water tables in the north; cropping of fallow areas in the south; effect of sea level rise; increased cropping intensity; and larger share of cash crops) and three levels of Yg closure (1: no yield increase; 2: Yg closure at a level equivalent to 50% (50% Yg closure); 3: Yg closure to a level of 85% of Yp (irrigated crops) and 80% of water-limited yield potential or Yw (rainfed crops) (full Yg closure)). In addition, changes in demand with low and high population growth rates, and substitution of rice by maize in future diets were also examined. Total aggregated demand of the three cereals (in milled rice equivalents) in 2030 and 2050, based on the UN median population variant, is projected to be 21 and 24% higher than in 2010. Current Yg represent 50% (irrigated rice), 48-63% (rainfed rice), 49% (irrigated wheat), 40% (rainfed wheat), 46% (irrigated maize), and 44% (rainfed maize) of their Yp or Yw. With 50% Yg closure and for various land use changes, self-sufficiency ratio will be > 1 for rice in 2030 and about one in 2050 but well below one for maize and wheat in both 2030 and 2050. With full Yg closure, self-sufficiency ratios will be well above one for rice and all three cereals jointly but below one for maize and wheat for all scenarios, except for the scenario with drastic decrease in boro rice area to allow for area expansion for cash crops. Full Yg closure of all cereals is needed to compensate for area decreases and demand increases, and then even some maize and large amounts of wheat imports will be required to satisfy demand in future. The results of this analysis have important implications for Bangladesh and other countries with high population growth rate, shrinking arable land due to rapid urbanization, and highly vulnerable to climate change.

13.
Plant Foods Hum Nutr ; 72(3): 280-287, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28660375

RESUMO

A diet with high glycaemic index, which causes rapid spikes in blood sugar level, can lead to disorders such as significantly increased risk for type 2 diabetes, cardiovascular disease and obesity. These conditions are also linked to the progression of cognitive decline and neurodegenerative diseases including Alzheimer's disease. Blackcurrant powder (BC) is a rich source of dietary fibre and bioactive compounds. Wholemeal wheat, barley and oat flours contain high amount of fibre. In this study, a model food (cookie) was developed and used to investigate the in vitro glycaemic glucose equivalent and antioxidant activities of the cookies made with three different wholemeal flours (wheat, barley and oat) with different replacement levels (5, 10 and 15%) of blackcurrant powder. Increasing the proportion of blackcurrant powder in the cookie resulted in a significant (P < 0.05) decrease in glucose release after in vitro digestion compared to the control. In addition, incorporation of blackcurrant powder in cookies up to 15% increased the antioxidant capacity. The combination of wholemeal flour and the bioactive compound rich blackcurrant has the potential to improve the nutritional value and reduce the glycaemic index of such foods.


Assuntos
Antioxidantes/análise , Fibras na Dieta/análise , Farinha/análise , Valor Nutritivo , Pós/análise , Ribes/química , Avena , Glicemia , Digestão , Índice Glicêmico , Hordeum , Humanos , Triticum
14.
Plant Cell ; 25(9): 3553-69, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24038652

RESUMO

Being sessile organisms, plants evolved sophisticated acclimation mechanisms to cope with abiotic challenges in their environment. These are activated at the initial site of exposure to stress, as well as in systemic tissues that have not been subjected to stress (termed systemic acquired acclimation [SAA]). Although SAA is thought to play a key role in plant survival during stress, little is known about the signaling mechanisms underlying it. Here, we report that SAA in plants requires at least two different signals: an autopropagating wave of reactive oxygen species (ROS) that rapidly spreads from the initial site of exposure to the entire plant and a stress-specific signal that conveys abiotic stress specificity. We further demonstrate that SAA is stress specific and that a temporal-spatial interaction between ROS and abscisic acid regulates rapid SAA to heat stress in plants. In addition, we demonstrate that the rapid ROS signal is associated with the propagation of electric signals in Arabidopsis thaliana. Our findings unravel some of the basic signaling mechanisms underlying SAA in plants and reveal that signaling events and transcriptome and metabolome reprogramming of systemic tissues in response to abiotic stress occur at a much faster rate than previously envisioned.


Assuntos
Ácido Abscísico/metabolismo , Aclimatação , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Regulação da Expressão Gênica de Plantas , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/genética , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Perfilação da Expressão Gênica , Luz , Metaboloma , Modelos Biológicos , NADPH Oxidases/genética , Análise de Sequência com Séries de Oligonucleotídeos , Raízes de Plantas , Plântula , Transdução de Sinais , Estresse Fisiológico
15.
IEEE Trans Nucl Sci ; 63(1): 316-324, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27182081

RESUMO

Baseline holder (BLH) circuits are used widely to stabilize the analog output of application-specific integrated circuits (ASICs) for high-count-rate applications. The careful design of BLH circuits is vital to the overall stability of the analog-signal-processing chain in ASICs. Recently, we observed self-triggered fluctuations in an ASIC in which the shaping circuits have a BLH circuit in the feedback loop. In fact, further investigations showed that methods of enhancing small-signal stabilities cause an even worse situation. To resolve this problem, we used large-signal analyses to study the circuit's stability. We found that a relatively small gain for the error amplifier and a small current in the non-linear stage of the BLH are required to enhance stability in large-signal analysis, which will compromise the properties of the BLH. These findings were verified by SPICE simulations. In this paper, we present our detailed analysis of the BLH circuits, and propose an improved version of them that have only minimal self-triggered fluctuations. We summarize the design considerations both for the stability and the properties of the BLH circuits.

16.
Phys Chem Chem Phys ; 17(4): 2550-9, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25493638

RESUMO

Ag nanoparticles (NPs) are successfully grown in situ on nanoporous Fe2O3 microboxes (Ag/Fe2O3) simply by annealing Prussian blue (PB) in the presence of silver nitrate for the first time. The catalytic activity of the Ag/Fe2O3 microboxes for the reduction of p-nitrophenol (PNP) with NaBH4 is measured by UV-vis spectroscopy. It is found that the composites exhibit bifunctional properties with high magnetization and excellent catalytic activity toward PNP reduction. The high catalytic activity of the catalyst might be attributed to its high surface area and the synergistic effect on the delivery of electrons between Ag NPs and Fe2O3 microboxes. In addition, efficient reduction is observed and found to depend upon the content of Ag in the Ag/Fe2O3 microboxes. The dosage of the catalyst and the reaction temperature were investigated. Furthermore, the catalysts can be easily recycled by applying an external magnetic field while maintaining the catalytic activity without significant decrease even after running six times. The unique properties provide an ideal platform to study various metal/Fe2O3 catalysts which can be potentially applied in a wide variety of fields of catalysis and green chemistry.

17.
Lett Appl Microbiol ; 60(2): 128-134, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25402810

RESUMO

White Spot Syndrome Virus (WSSV) is a dsDNA virus causing White Spot Syndrome Disease (WSSD) in shrimp with almost 100% morality rate within 3-10 days. In Bangladesh, WSSD is one of the major impediments of shrimp farming. This study first investigated the prevalence and distribution of WSSV in cultured shrimps of the coastal regions in Bangladesh. A total of 60 shrimp samples, collected from the 25 shrimp farms of different coastal regions (Satkhira, Khulna, Bagerhat and Cox's Bazar), were analysed during 2013-2014 by conventional PCR using VP28 and VP664 gene-specific primers; 39 of 60 samples were found WSSV positive. SYBR green real-time PCR using 71-bp amplicon for VP664 gene correlated well with conventional PCR data. The prevalence rates of WSSV among the collected 60 samples were Satkhira 79%, Khulna 50%, Bagerhat 38% and Cox's Bazar 25%. Sequencing of WSSV-positive PCR amplicons of VP28 showed 99% similarity with WSSV NCBI Ref/Seq Sequences. Molecular analysis of the VP28 gene sequences of WSSV revealed that Bangladeshi strains phylogenetically affiliated to the strains belong to India. This work concluded that WSSV infections are widely distributed in the coastal regions cultured shrimp in Bangladesh.


Assuntos
Aquicultura , Penaeidae/virologia , Vírus da Síndrome da Mancha Branca 1/isolamento & purificação , Animais , Bangladesh , Índia , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Vírus da Síndrome da Mancha Branca 1/classificação , Vírus da Síndrome da Mancha Branca 1/genética
18.
Bangladesh Med Res Counc Bull ; 41(2): 52-58, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29624282

RESUMO

During the last decade, survival rates for breast cancer have increased as a result of earlier detection and increased use of adjuvant therapy. Limited data exist on the post mastectomy quality of life in the process of transition from health to cancer in its different phases of treatment. The aim of current study was to evaluate the changes of health-related quality of life (HRQoL) after mastectomy and to measure their impression about future perspectives in Bangladeshi Breasts cancer patients. A group of 250 women with a diagnosis of primary breast cancer who was admitted in the department of surgical oncology in National Institute of Cancer Research and Hospital, Dhaka were enrolled in this study from January 2012 to March 2013. Two-point interview like pre(MI) and post mastectomy(M2) was taken using the structured questionnaire made by European Organization for Research and Treatment of Cancer (EORTC)- EORTC Q30 and BR23. The mean age of the patients was 44.7?9.87 years, 52.6% were locally advanced. HRQoL scores of breast cancer patients deteriorated after mastectomy, general features like presence of fatigability, nausea, apatite loss, sleeplessness and pain has got tremendous effect on the quality of life(p<.005). Financial difficulties and sleep disorders did not affect much. Four of the Global Health status/QOL parameters like physical functioning, role functioning, emotional functioning, cognitive functioning deteriorated but only physical functioning status affected significantly(p<0.005). Breast symptoms like body image problem, general breast symptoms like pain, arm swelling and sexual feeling affected their (HRQOL) after mastectomy. A diagnosis of cancer and associated treatments affects multiple domains of life. The complicated transitions between health, illness and living with cancer can often be challenged with a preoperative information for the patient confronted with breast cancer should include possible psychological effects of cancer diagnosis, surgery, and other treatment. Breast conservation particularly in the young group may give a better outcome in the treatment protocol of breast cancer patients.


Assuntos
Neoplasias da Mama/cirurgia , Mastectomia , Qualidade de Vida , Adulto , Idoso , Bangladesh , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Inquéritos e Questionários
19.
Bangladesh Med Res Counc Bull ; 41(1): 13-8, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27089629

RESUMO

Obstructive sleep apnea hypopnea syndrome (OSAHS) is the occurrence of repetitive episodes of complete or partial upper airway obstruction during sleep in association with loud snoring and daytime sleepiness and is a risk factor for hypertension, cardiovascular and cerebrovascular diseases and more. The present study was performed to assess the prevalence as well as the clinical and anthropometric predictors of OSAHS in an urban community of middle aged Bangladeshi population. The study was a cross-sectional, community-based prevalence study which was performed in an urban community in Dhanmondi Thana Pourashava of Dhaka city from July 2007 to June 2008. About 2500 citizens, aged 30-60 years were included in the study. In stage one of the study, they were informed about the polysomnography (PSG) study (stage two of the study) and 2250 of them gave consent. Subjects were then divided into habitual (495) and non-habitual snorers (1755). Among 2250 subjects, the prevalence of obstructive sleep apnea hypopnea (OSAH) in habitual snorers was 48.33% (239/495), and that in non-habitual snorers was 1.66% (29/1755). So, the overall prevalence of OSAH in the screened population was 11.91%, and that of OSAHS was 3.29%. Likewise, the prevalence of OSAH and OSAHS in men were 17.37% and 4.49%, respectively and 6.25% and 2.14% in women. Multivariate analysis revealed that male gender, age, obesity (defined by a high body mass index), waist/hip ratio were significant risk factors for OSAHS. These findings can help us in identifying the prevalence of OSAHS in the community and further planning in the management of obesity and cardiovascular diseases.


Assuntos
Apneia Obstrutiva do Sono/epidemiologia , Adulto , Antropometria , Bangladesh/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Prevalência , Fatores de Risco
20.
ScientificWorldJournal ; 2014: 457187, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24701169

RESUMO

Aluminum (Al) sensitive wheat cultivar kalyansona was grown for 14 d in a range of Ca solution (125, 625, and 2500 µM) plus other nutrients without Al. At 14 d after Ca treatment, half of these plants were harvested (H1), and the rest of the plants were exposed to 100 µM Al for additional 6 d and harvested (H2). Severe Al injury was found only in the plants with the lowest supply of Ca before Al treatment. Aluminum concentration in the apoplastic fluid was very high at 125 µM Ca probably because the plasma membrane of some of the cells was destroyed due to the attack of 100 µM Al. Aluminum content in roots decreased with increasing supply of Ca before Al treatment. Calcium content decreased drastically at harvest (H2) in the plants with 100 µM Al. Under Al stress conditions, the plant responded to Al in different ways due to not only the different Ca supply but also the variation of Ca content in the plant tissues. Actually, the plants having the largest Ca content in the roots before Al treatment can receive less Al injury during Al treatment. To substantiate this idea, a companion study was conducted to investigate the effects of 2500 µM Ca supply during, before, and after 100 µM Al treatment on root growth. The results indicated clearly that exogenous Ca supply before Al treatment is able to alleviate Al injury but less effective than Ca supply during Al treatment.


Assuntos
Alumínio/toxicidade , Cálcio/administração & dosagem , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento
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