Página 21 dos resultados de 124249 itens digitais encontrados em 0.132 segundos

Differential Regulation of ER Ca2+ Uptake and Release Rates Accounts for Multiple Modes of Ca2+-induced Ca2+ Release

Albrecht, Meredith A.; Colegrove, Stephen L.; Friel, David D.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em /03/2002 EN
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The ER is a central element in Ca2+ signaling, both as a modulator of cytoplasmic Ca2+ concentration ([Ca2+]i) and as a locus of Ca2+-regulated events. During surface membrane depolarization in excitable cells, the ER may either accumulate or release net Ca2+, but the conditions of stimulation that determine which form of net Ca2+ transport occurs are not well understood. The direction of net ER Ca2+ transport depends on the relative rates of Ca2+ uptake and release via distinct pathways that are differentially regulated by Ca2+, so we investigated these rates and their sensitivity to Ca2+ using sympathetic neurons as model cells. The rate of Ca2+ uptake by SERCAs (JSERCA), measured as the t-BuBHQ-sensitive component of the total cytoplasmic Ca2+ flux, increased monotonically with [Ca2+]i. Measurement of the rate of Ca2+ release (JRelease) during t-BuBHQ-induced [Ca2+]i transients made it possible to characterize the Ca2+ permeability of the ER (documentclass[10pt]{article} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{pmc} usepackage[Euler]{upgreek} pagestyle{empty} oddsidemargin -1.0in egin{document} egin{equation*}overline{{mathrm{P}}}_{{mathrm{ER}}}end{equation*}end{document})...

State-Dependent Inactivation of the α1g T-Type Calcium Channel

Serrano, Jose R.; Perez-Reyes, Edward; Jones, Stephen W.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/08/1999 EN
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We have examined the kinetics of whole-cell T-current in HEK 293 cells stably expressing the α1G channel, with symmetrical Na+i and Na+o and 2 mM Ca2+o. After brief strong depolarization to activate the channels (2 ms at +60 mV; holding potential −100 mV), currents relaxed exponentially at all voltages. The time constant of the relaxation was exponentially voltage dependent from −120 to −70 mV documentclass[10pt]{article} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{pmc} usepackage[Euler]{upgreek} pagestyle{empty} oddsidemargin -1.0in egin{document} egin{equation*}({mathrm{e-fold;for}};31;{mathrm{mV}};;{mathrm{{ au}}};=;2.5;{mathrm{ms;at}};-100;{mathrm{mV}})end{equation*}end{document}, but documentclass[10pt]{article} usepackage{amsmath} usepackage{wasysym} usepackage{amsfonts} usepackage{amssymb} usepackage{amsbsy} usepackage{mathrsfs} usepackage{pmc} usepackage[Euler]{upgreek} pagestyle{empty} oddsidemargin -1.0in egin{document} egin{equation*}{mathrm{{ au}}};=;12{ aisebox{1mm}{line(1,0){6}}}17;{mathrm{ms;from}}-40;{mathrm{to}};+60;{mathrm{mV}}end{equation*}end{document}. This suggests a mixture of voltage-dependent deactivation (dominating at very negative voltages) and nearly voltage-independent inactivation. Inactivation measured by test pulses following that protocol was consistent with open-state inactivation. During depolarizations lasting 100–300 ms...

Role of electrical stimulation for rehabilitation and regeneration after spinal cord injury: an overview

Hamid, Samar; Hayek, Ray
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
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Structural discontinuity in the spinal cord after injury results in a disruption in the impulse conduction resulting in loss of various bodily functions depending upon the level of injury. This article presents a summary of the scientific research employing electrical stimulation as a means for anatomical or functional recovery for patients suffering from spinal cord injury. Electrical stimulation in the form of functional electrical stimulation (FES) can help facilitate and improve upper/lower limb mobility along with other body functions lost due to injury e.g. respiratory, sexual, bladder or bowel functions by applying a controlled electrical stimulus to generate contractions and functional movement in the paralysed muscles. The available rehabilitative techniques based on FES technology and various Food and Drug Administration, USA approved neuroprosthetic devices that are in use are discussed. The second part of the article summarises the experimental work done in the past 2 decades to study the effects of weakly applied direct current fields in promoting regeneration of neurites towards the cathode and the new emerging technique of oscillating field stimulation which has shown to promote bidirectional regeneration in the injured nerve fibres. The present article is not intended to be an exhaustive review but rather a summary aiming to highlight these two applications of electrical stimulation and the degree of anatomical/functional recovery associated with these in the field of spinal cord injury research.

Microarray Analysis of Differentially Expressed Genes between Cysts and Trophozoites of Acanthamoeba castellanii

Moon, Eun-Kyung; Xuan, Ying-Hua; Chung, Dong-Il; Hong, Yeonchul; Kong, Hyun-Hee
Fonte: The Korean Society for Parasitology Publicador: The Korean Society for Parasitology
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.857773%
Acanthamoeba infection is difficult to treat because of the resistance property of Acanthamoeba cyst against the host immune system, diverse antibiotics, and therapeutic agents. To identify encystation mediating factors of Acanthamoeba, we compared the transcription profile between cysts and trophozoites using microarray analysis. The DNA chip was composed of 12,544 genes based on expressed sequence tag (EST) from an Acanthamoeba ESTs database (DB) constructed in our laboratory, genetic information of Acanthamoeba from TBest DB, and all of Acanthamoeba related genes registered in the NCBI. Microarray analysis indicated that 701 genes showed higher expression than 2 folds in cysts than in trophozoites, and 859 genes were less expressed in cysts than in trophozoites. The results of real-time PCR analysis of randomly selected 9 genes of which expression was increased during cyst formation were coincided well with the microarray results. Eukaryotic orthologous groups (KOG) analysis showed an increment in T article (signal transduction mechanisms) and O article (posttranslational modification, protein turnover, and chaperones) whereas significant decrement of C article (energy production and conversion) during cyst formation. Especially...

Compensation for Work-Related Hematologic, Liver, and Infectious Diseases

Kim, Jung-Won; Kang, Dong-Mug
Fonte: The Korean Academy of Medical Sciences Publicador: The Korean Academy of Medical Sciences
Tipo: Artigo de Revista Científica
EN
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35.876328%
Occupational diseases may be defined only medically or scientifically, and even then, their definition is not simple. However, compensable occupational diseases involve the additional layer of legal systems and social welfare policies as well. Their multifaceted nature makes determining the work-relatedness of these diseases more complex. Korea has established standards for the recognition of occupational diseases in Schedule 5 of the Enforcement Decree of the Labor Standards Act, and specific criteria for the recognition of occupational diseases are listed in Schedule 3 of the Enforcement Decree of the Industrial Accident Compensation Insurance Act. The new list of compensable occupational diseases comprises 13 articles as an open-ended system. The newly added articles pertain to lymphohematopoietic (Article 5) and infectious diseases (Article 9), as well as diseases of other target organs. Furthermore, the article on liver diseases (Article 8) has been partially revised. The new act has been changed to clarify the meaning as it has been presented in recent research. It is necessary to achieve agreement among concerned parties, including experts from the legal, medical, and social domains to resolve the issues of work-relatedness...

Rapid genomic DNA changes in allotetraploid fish hybrids

Wang, J; Ye, L H; Liu, Q Z; Peng, L Y; Liu, W; Yi, X G; Wang, Y D; Xiao, J; Xu, K; Hu, F Z; Ren, L; Tao, M; Zhang, C; Liu, Y; Hong, Y H; Liu, S J
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
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Rapid genomic change has been demonstrated in several allopolyploid plant systems; however, few studies focused on animals. We addressed this issue using an allotetraploid lineage (4nAT) of freshwater fish originally derived from the interspecific hybridization of red crucian carp (Carassius auratus red var., ♀, 2n=100) × common carp (Cyprinus carpio L., ♂, 2n=100). We constructed a bacterial artificial chromosome (BAC) library from allotetraploid hybrids in the 20th generation (F20) and sequenced 14 BAC clones representing a total of 592.126 kb, identified 11 functional genes and estimated the guanine–cytosine content (37.10%) and the proportion of repetitive elements (17.46%). The analysis of intron evolution using nine orthologous genes across a number of selected fish species detected a gain of 39 introns and a loss of 30 introns in the 4nAT lineage. A comparative study based on seven functional genes among 4nAT, diploid F1 hybrids (2nF1) (first generation of hybrids) and their original parents revealed that both hybrid types (2nF1 and 4nAT) not only inherited genomic DNA from their parents, but also demonstrated rapid genomic DNA changes (homoeologous recombination, parental DNA fragments loss and formation of novel genes). However...

Customized Asthma Control Test with Reflection on Sociocultural Differences

Yoo, Kwang-Ha; Jeong, Jae-Won; Yoon, Ho-Joo; Chang, Suk-Il; Moon, Hee-Bom; Choi, Byoung-Hwui; Kim, You-Young; Cho, Sang-Heon
Fonte: The Korean Academy of Medical Sciences Publicador: The Korean Academy of Medical Sciences
Tipo: Artigo de Revista Científica
EN
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We evaluated the utility and feasibility of customizing Asthma Control Test (ACT) items to generate a Korean Asthma Control Test (KACT) specific for Korean patients. We surveyed 392 asthma patients with 19 items, selected to reflect the Korean sociocultural context. Guideline ratings were integrated with the evaluations of specialists (i.e., using both guide base rating together with specialist's rating), and items with the greatest discriminating validity were identified. Stepwise regression methods were used to select items. KACT scale scores showed significant differences between the asthma control ratings generated by integrating ratings (r=0.77, P<0.001), by specialist's evaluations (r=0.54, P<0.001), or by FEV1 percent predicted (r=0.39, P<0.001). Specialist's and guideline ratings detected 56% and 48.6% of patients with well-controlled asthma, respectively. However, the integrated ratings indicated that only 34.3% of the patients in the test sample were well controlled. The overall agreement between KACT and the integrated rating ranged from 45% to 78%, depending on the cut-off points used. It is possible to formulate a valid, useful country-specific diagnostic tool for the assessment of asthma patients based on the original ACT that reflect differences in sociocultural context.

The value of second-opinion pathology diagnoses on prostate biopsies from patients referred for management of prostate cancer

Barqawi, Al B; Turcanu, Ruslan; Gamito, Eduard J; Lucia, Scott M; O'Donnell, Colin I; Crawford, E David; La Rosa, David D; La Rosa, Francisco G
Fonte: e-Century Publishing Corporation Publicador: e-Century Publishing Corporation
Tipo: Artigo de Revista Científica
EN
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Gleason score (GS) (sum of primary plus secondary grades) is used to predict patients' clinical outcome and to customize treatment strategies for prostate cancer (PC). However, due in part to pathologist misreading, there is significant discrepancy of GS between needle-core biopsies (NCB) and radical prostatectomy specimens. We assessed the requirement for re-evaluating NCB diagnosed by outside pathologists in patients referred to our institution for management of PC. In 100 patients, we reviewed both their original “outside” and second-opinion (“in-house”) diagnoses of the same NCB specimens, and compared them with the diagnoses of the whole-mount radical prostatectomy (WMRP) specimens (gold standard for analysis). We found that both outside and in-house biopsy GS vary significantly from the WMRP diagnoses, with GS undergrading substantially predominating above overgrading. Statistical analysis demonstrated that the main diagnostic discrepancy was in the differentiation between primary and secondary Gleason grades (mainly 3 and 4) and that outside NCB GS was significantly less accurate with respect to the WMRP specimens than the in-house NCB GS. In addition, in a different cohort of 65 NCB cases, we found that in 5 out of 11 patients...

Genomic-enabled prediction with classification algorithms

Ornella, L; Pérez, P; Tapia, E; González-Camacho, J M; Burgueño, J; Zhang, X; Singh, S; Vicente, F S; Bonnett, D; Dreisigacker, S; Singh, R; Long, N; Crossa, J
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
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Pearson's correlation coefficient (ρ) is the most commonly reported metric of the success of prediction in genomic selection (GS). However, in real breeding ρ may not be very useful for assessing the quality of the regression in the tails of the distribution, where individuals are chosen for selection. This research used 14 maize and 16 wheat data sets with different trait–environment combinations. Six different models were evaluated by means of a cross-validation scheme (50 random partitions each, with 90% of the individuals in the training set and 10% in the testing set). The predictive accuracy of these algorithms for selecting individuals belonging to the best α=10, 15, 20, 25, 30, 35, 40% of the distribution was estimated using Cohen's kappa coefficient (κ) and an ad hoc measure, which we call relative efficiency (RE), which indicates the expected genetic gain due to selection when individuals are selected based on GS exclusively. We put special emphasis on the analysis for α=15%, because it is a percentile commonly used in plant breeding programmes (for example, at CIMMYT). We also used ρ as a criterion for overall success. The algorithms used were: Bayesian LASSO (BL), Ridge Regression (RR), Reproducing Kernel Hilbert Spaces (RHKS)...

The use of alternative forms of graphical analysis to balance bias and precision in PET images

Logan, Jean; Alexoff, David; Fowler, Joanna S
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
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Graphical analysis (GA) is an efficient method for estimating total tissue distribution volume (VT) from positron emission tomography (PET) uptake data. The original GA produces a negative bias in VT in the presence of noise. Estimates of VT using other GA forms have less bias but less precision. Here, we show how the bias terms are related between the GA methods and how using an instrumental variable (IV) can also reduce bias. Results are based on simulations of a two-compartment model with VT's ranging from 10.5 to 64 mL/cm3 and from PET image data with the tracer [11C]DASB ([11C]-3-amino-4-(2-dimethylaminomethyl-phenylsulfanyl) benzonitrile). Four estimates of VT (or distribution volume ratio (DVR) using a reference tissue) can be easily computed from different formulations of GA including the IV. As noise affects the estimates from all four differently, they generally do not provide the same estimates. By taking the median value of the four estimates, we can decrease the bias and reduce the effect of large values contributing to noisy images. The variance of the four estimates can serve as a guide to the reliability of the median estimate. This may provide a general method for the generation of parametric images with little bias and good precision.

An improved Greengenes taxonomy with explicit ranks for ecological and evolutionary analyses of bacteria and archaea

McDonald, Daniel; Price, Morgan N; Goodrich, Julia; Nawrocki, Eric P; DeSantis, Todd Z; Probst, Alexander; Andersen, Gary L; Knight, Rob; Hugenholtz, Philip
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
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35.87876%
Reference phylogenies are crucial for providing a taxonomic framework for interpretation of marker gene and metagenomic surveys, which continue to reveal novel species at a remarkable rate. Greengenes is a dedicated full-length 16S rRNA gene database that provides users with a curated taxonomy based on de novo tree inference. We developed a ‘taxonomy to tree' approach for transferring group names from an existing taxonomy to a tree topology, and used it to apply the Greengenes, National Center for Biotechnology Information (NCBI) and cyanoDB (Cyanobacteria only) taxonomies to a de novo tree comprising 408 315 sequences. We also incorporated explicit rank information provided by the NCBI taxonomy to group names (by prefixing rank designations) for better user orientation and classification consistency. The resulting merged taxonomy improved the classification of 75% of the sequences by one or more ranks relative to the original NCBI taxonomy with the most pronounced improvements occurring in under-classified environmental sequences. We also assessed candidate phyla (divisions) currently defined by NCBI and present recommendations for consolidation of 34 redundantly named groups. All intermediate results from the pipeline, which includes tree inference...

A descriptive analysis of disorders in patients 17 years following motor vehicle accidents

Bunketorp, L.; Nordholm, L.; Carlsson, J.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
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Whiplash-associated disorders (WAD) are described and analysed 17 years after involvement in a motor vehicle accident. A self-report questionnaire was mailed to 121 patients registered at emergency departments in Gothenburg in 1983 because of neck complaints following a car collision. The questionnaire contained items on symptoms referred to WAD, treatment, work disability, involvement in settlement of claims, medical disability and the Neck Disability Index (NDI). Of the 121 patients, 108 (89%) chose to participate in the present study. Fifty-nine (55%) had residual disorders referable to the original accident. Neck pain, radiating pain and headache were the most common symptoms. One-third of the patients with residual symptoms suffered from work disability, compared to 6% in the group of patients without residual disorders. All 25 patients who had reached a final claim settlement (42%) had a poor outcome, and 15 of the claiming patients had been assigned a medical disability ranging from 5 to 30%. Patients with WAD reported a significantly higher score on the NDI than those without residual disorders. There was no significant correlation between the patients' degree of medical disability and the scores on the NDI. The results of the study show that approximately half of the patients with neck complaints following motor vehicle accidents in Gothenburg in 1983 suffered frequent residual symptoms 17 years after the accident...

Improvement of Induction Remission Rate by Modifying the Dose of Idarubicin for Relapsed Childhood Acute Lymphoblastic Leukemia

Yoon, Jong Hyung; Park, Jeong Ah; Kim, Eun Kyung; Kang, Hyoung Jin; Shin, Hee Young; Ahn, Hyo Seop
Fonte: The Korean Academy of Medical Sciences Publicador: The Korean Academy of Medical Sciences
Tipo: Artigo de Revista Científica
EN
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Relapse is the major cause of treatment failure in acute lymphoblastic leukemia (ALL), yet there is no established treatment for relapsed ALL. To improve the induction remission rate, we modified the dose of idarubicin in the original Children's Cancer Group (CCG)-1884 protocol, and retrospectively compared the results. Twenty-eight patients diagnosed with relapsed ALL received induction chemotherapy according to the CCG-1884 protocol. Complete remission (CR) rate in all patients after induction chemotherapy was 57%. The idarubicin 10 mg/m2/week group showed CR rate of 74%, compared with the 22% CR rate of the idarubicin 12.5 mg/m2/week group (p=0.010). Remission failure due to treatment-related mortality (TRM) was 44% and 5.2% in the idarubicin 12.5 mg/m2/week and 10 mg/m2/week groups, respectively (p=0.011). Overall survival (OS) and 4-yr event-free survival (EFS) were 12.8% and 10.3%, respectively. OS and 4-yr EFS were higher in the idarubicin 10 mg/m2/week group (19.3% and 15.6%) than in the 12.5 mg/m2/week group (0% and 0%). In conclusion, a modified dose of idarubicin from 12.5 mg/m2/week to 10 mg/m2/week resulted in an improved CR rate in the treatment of relapsed ALL, which was due to lower TRM. However, despite improved CR rate with modified dose of idarubicin...

Necropsy of original case of Lowry's syndrome.

Dolman, C L; Wright, V J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1978 EN
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The necropsy findings are reported on one of the original sibs of Lowry's syndrome. The child, who died at 7 years of bronchopneumonia, was severely dwarfed, microcephalic, and microphthalmic. The brain was small and extensively calcified, the cerebellar cortex hypoplastic, and the retinae atrophic. There were multiple skeletal and integumental and minor renal abnormalities. The lymphoid tissue was much reduced, and many arteries and arterioles were thickened and narrowed. This constitutes a unique constellation of lesions.

Morphological and microscopic characterization of five commonly-used testacean traditional Chinese medicines

Xu, Ying; Song, Wei; Zhou, Ping; Li, Ping; Li, Huijun
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
EN
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Testacean traditional Chinese medicine (TTCM), derived from the outer shell of sea or freshwater mollusks, is a special and important category of Chinese medicinal materials. To ensure the effective use of TTCM, a comparative identification study was performed on five commonly-used testacean drugs, including Haliotidis Concha, Arcae Concha, Meretricis Concha, Ostreae Concha and Margaritifera Concha (Shijueming, Walengzi, Geqiao, Muli and Zhenzhumu in Chinese, respectively). Typical morphological photographs of the crude drugs were acquired, and the key microscopic characteristics of the derived powders under normal light microscope and polarized light microscope were summarized. The major results can be concluded as follows: (1) the original species involved in the five TTCMs could be distinguished by their respective interspecies morphological characteristics; (2) the key identification characteristics of the five powdered crude drugs were mainly crystal fragments, with the fragment features under both normal light and polarized light microscope providing powerful points for differentiating the five commonly-used testacean drugs. This study demonstrated that it is feasible to provide authentication for these five kinds of TTCMs by the combination of morphology with microscopy.

Validation in the Cross-Cultural Adaptation of the Korean Version of the Oswestry Disability Index

Jeon, Chang-Hoon; Kim, Dong-Jae; Kim, Se-Kang; Kim, Dong-Jun; Lee, Hwan-Mo; Park, Heui-Jeon
Fonte: The Korean Academy of Medical Sciences Publicador: The Korean Academy of Medical Sciences
Tipo: Artigo de Revista Científica
EN
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Disability questionnaires are used for clinical assessment, outcome measurement, and research methodology. Any disability measurement must be adapted culturally for comparability of data, when the patients, who are measured, use different languages. This study aimed to conduct cross-cultural adaptation in translating the original (English) version of the Oswestry Disability Index (ODI) into Korean, and then to assess the reliability of the Korean versions of the Oswestry Disability Index (KODI). We used methodology to obtain semantic, idiomatic, experimental, and conceptual equivalences for the process of cross-cultural adaptation. The KODI were tested in 116 patients with chronic low back pain. The internal consistency and reliability for the KODI reached 0.9168 (Cronbach's alpha). The test-retest reliability was assessed with 32 patients (who were not included in the assessment of Cronbach's alpha) over a time interval of 4 days. Test-retest correlation reliability was 0.9332. The entire process and the results of this study were reported to the developer (Dr. Fairbank JC), who appraised the KODI. There is little evidence of differential item functioning in KODI. The results suggest that the KODI is internally consistent and reliable. Therefore...

EFFECTIVENESS OF CARBAMIDE PEROXIDE AND SODIUM PERBORATE IN NON-VITAL DISCOLORED TEETH

Valera, Marcia Carneiro; Camargo, Carlos Henrique Ribeiro; Carvalho, Cláudio Antonio Talge; de Oliveira, Luciane Dias; Camargo, Samira Esteves Afonso; Rodrigues, Cristiana Martins
Fonte: Faculdade de Odontologia de Bauru da Universidade de São Paulo Publicador: Faculdade de Odontologia de Bauru da Universidade de São Paulo
Tipo: Artigo de Revista Científica
Publicado em /06/2009 EN
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Objective: To evaluate the efficacy of 16% carbamide peroxide gel (CP16%), tetrahydrate sodium perborate (SP) and mixture (CP16% + SP), in walking bleaching of non-vital discolored teeth. Materials and methods: Sixty single-rooted human premolars with intact crowns were used and initial color was assessed using Vita shade guide and standardized photos. The teeth were stained using rabbit fresh blood for 18 days and photos of discolored teeth and color evaluation were performed. The teeth were divided into 4 groups (n = 15), according to bleaching agent used: G1) CP16% gel; G2) CP16% gel + SP; G3) SP + distilled water; G4: control. The bleaching agents were replaced twice at 7-day intervals for 21 days. All teeth were evaluated by two endodontists at days 0, 7, 14 and 21 and the color changes were assessed using Vita shade guide and standardized photos. The results were analyzed by Kruskal-Wallis and Dunn's tests (p=0.05). Results: The experimental groups presented statistically similar bleaching results (p>0.05) at the end of 7, 14 and 21 days. These groups presented significantly higher bleaching efficacy than control group (G4) (p<0.05). The mixture CP16% + SP promoted return of original color in 100% of teeth at the end of 21 days. Conclusion: It was concluded that three bleaching agents were effective in bleaching of stained teeth with blood products...

Long-term nitrogen fertilization of paddy soil shifts iron-reducing microbial community revealed by RNA-13C-acetate probing coupled with pyrosequencing

Ding, Long-Jun; Su, Jian-Qiang; Xu, Hui-Juan; Jia, Zhong-Jun; Zhu, Yong-Guan
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
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Iron reduction is an important biogeochemical process in paddy soils, yet little is known about the microbial coupling between nitrogen and iron reduction. Here, we investigated the shift of acetate-metabolizing iron-reducers under long-term nitrogen fertilization using 13C-acetate-based ribosomal RNA (rRNA)-stable isotope probing (SIP) and pyrosequencing in an incubation experiment, and the shift of putative iron-reducers in original field samples were investigated by 16S rRNA gene-based pyrosequencing. During SIP incubations, in the presence of iron(III) oxyhydroxides, more iron(II) formation and less methane production were detected in nitrogen-fertilized (N) compared with non-fertilized (NF) soil. In 13C-rRNA from microcosms amended with ferrihydrite (FER), Geobacter spp. were the important active iron-reducers in both soils, and labeled to a greater extent in N (31% of the bacterial classified sequences) than NF soils (11%). Pyrosequencing of the total 16S rRNA transcripts from microcosms at the whole community level further revealed hitherto unknown metabolisms of potential FER reduction by microorganisms including Pseudomonas and Solibacillus spp. in N soil, Dechloromonas, Clostridium, Bacillus and Solibacillus spp. in NF soil. Goethite (GOE) amendment stimulated Geobacter spp. to a lesser extent in both soils compared with FER treatment. Pseudomonas spp. in the N soil and Clostridium spp. in the NF soil may also be involved in GOE reduction. Pyrosequencing results from field samples showed that Geobacter spp. were the most abundant putative iron-reducers in both soils...

Hybrid incompatibilities in the parasitic wasp genus Nasonia: negative effects of hemizygosity and the identification of transmission ratio distortion loci

Koevoets, T; Niehuis, O; van de Zande, L; Beukeboom, L W
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN
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The occurrence of hybrid incompatibilities forms an important stage during the evolution of reproductive isolation. In early stages of speciation, males and females often respond differently to hybridization. Haldane's rule states that the heterogametic sex suffers more from hybridization than the homogametic sex. Although haplodiploid reproduction (haploid males, diploid females) does not involve sex chromosomes, sex-specific incompatibilities are predicted to be prevalent in haplodiploid species. Here, we evaluate the effect of sex/ploidy level on hybrid incompatibilities and locate genomic regions that cause increased mortality rates in hybrid males of the haplodiploid wasps Nasonia vitripennis and Nasonia longicornis. Our data show that diploid F1 hybrid females suffer less from hybridization than haploid F2 hybrid males. The latter not only suffer from an increased mortality rate, but also from behavioural and spermatogenic sterility. Genetic mapping in recombinant F2 male hybrids revealed that the observed hybrid mortality is most likely due to a disruption of cytonuclear interactions. As these sex-specific hybrid incompatibilities follow predictions based on Haldane's rule, our data accentuate the need to broaden the view of Haldane's rule to include species with haplodiploid sex determination...

RNA Extraction from Animal and Human's Cancerous Tissues: Does Tissue Matter?

Samadani, Ali Akbar; Nikbakhsh, Novin; Fattahi, Sadegh; Pourbagher, Roghayeh; Aghajanpour Mir, Seyyed Mohsen; Mousavi Kani, Narges; Abedian, Zeinab; Akhavan-Niaki, Haleh
Fonte: Babol University of Medical Sciences Publicador: Babol University of Medical Sciences
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
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The reliability of gene expression profiling, based technologies and methods to find transcriptional differences representative of the original samples is influenced by the quality of the extracted RNA. Hence, RNA extraction is the first step to investigate the gene expression and its function. Consequently, the quality of extracted RNA is really significant. Correspondingly, this research was accomplished to optimize the RNA extraction methods and compare the amounts of tissue or quality of tissue. Relatively, the cancerous tissue of human stomach in fresh and frozen conditions and also the mouse fresh tissue were studied. Some factors like the amount of samples, efficacy differences of diverse extraction buffers (TriPure, Trizol) and also the efficacy of b-mercaptoethanol were compared and investigated. The results indicated that the less amount (1-2 mg) compared to other amounts (2-5 mg, 5-15 mg) yielded the best quality and the RNA bands (5S, 18S, 28S) were observed perfectly. Relatively, comparing and measuring some kinds of buffers (Trizol, TriPure) indicated no difference in RNA extraction quality. The last investigated factor was the effect of b- mercaptoethanol which was used along with TriPure to remove the RNAse. Conclusively...