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2.
Int Heart J ; 62(2): 298-304, 2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33731524

RESUMO

Radiofrequency and cryoballoon applications around the pulmonary veins (PVs) could provoke a vagal reflex (VR) by modulating the intrinsic cardiac autonomic nervous system (ICANS).This study aimed to investigate the incidence, timing, and clinical impact of a VR provoked by a laser balloon application for a PV isolation (PVI).A total of 92 consecutive paroxysmal atrial fibrillation (PAF) patients underwent a laser balloon PVI of PAF. Acute changes in the heart rate and blood pressure were recorded. The heart rate variability (HRV) was tested by Holter ECGs before and at three months following the ablation. Three hundred forty-five out of 363 PVs were successfully isolated (97%) with laser balloon applications. A VR such as sinus bradycardia (26.1%), transient sinus arrest (9.8%), transient atrioventricular block (1.1%), or a blood pressure reduction (8.7%) was observed during the laser balloon applications for the PVI. The follow-up ended at 12 months. The HRV attenuation was comparable before and at three months after the ablation procedure between that with and without a VR (P = 0.14). The PAF recurrence rate was also comparable between the two groups (P = 0.882).The laser balloon PVI often provoked a VR, however, the modulation of the ICANS was temporary and for up to three months as measured by the HRV changes after the ablation, and the freedom from any atrial fibrillation recurrence was comparable regardless of the occurrence of a VR.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Frequência Cardíaca/fisiologia , Terapia a Laser/métodos , Taquicardia Paroxística/cirurgia , Nervo Vago/fisiopatologia , Idoso , Fibrilação Atrial/fisiopatologia , Eletrocardiografia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Taquicardia Paroxística/fisiopatologia , Fatores de Tempo
3.
Biomed Mater ; 16(2): 025017, 2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33445157

RESUMO

In this study, three-dimensional (3D) cardiac tissue constructed using the pin type bioprinter 'microscopic painting device' and layer-by-layer cell coating technique was confirmed to have drug responsiveness by three different analytical methods for cardiotoxicity assay. Recently, increasing attention has been focused on biofabrication to create biomimetic 3D tissue. Although various tissues can be produced in vitro, there are many issues surrounding the stability and reproducibility of the preparation of 3D tissues. Thus, although many bioprinters have been developed, none can efficiently, reproducibly and precisely produce small 3D tissues (µm-mm order) such as spheroids, which are most commonly used in drug development. The 3D cardiac tissue chips were successfully constructed with a similar number of cells as conventional 2D tissue using a pin type bioprinter, and corresponding drug-induced cardiotoxicities were obtained with known compounds that induce cardiotoxicity. The 3D cardiac tissue chips displayed uniform cell density and completely synchronized electrophysiological properties as compared to 2D tissue. The 3D tissues constructed using a pin type bioprinter as a biofabrication device would be promising tools for cardiotoxicity assay as they are capable of obtaining stable and reproducible data, which cannot be obtained by 2D tissue.


Assuntos
Biomimética , Bioimpressão , Cardiotoxicidade , Técnicas de Cultura de Células , Coração/fisiologia , Coração/fisiopatologia , Impressão Tridimensional , Cálcio/metabolismo , Contagem de Células , Diferenciação Celular , Descoberta de Drogas , Desenho de Equipamento , Fibroblastos/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Reprodutibilidade dos Testes
4.
Soft Matter ; 16(18): 4549-4554, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32364199

RESUMO

Membrane adhesion is a ubiquitous phenomenon in cells and is related to various biological events such as migration, morphogenesis, and differentiation. To understand the physicochemical aspects of membrane adhesion, liposome-liposome adhesion and liposome-substrate adhesion have been studied. Although membrane adhesion has been shown to increase membrane tension and inhibit lipid diffusion, the relationship between these changes and the degree of membrane adhesion have not been quantified. Here, we analyzed the dependence of membrane tension and lipid diffusion on the degree of membrane adhesion, i.e., area fraction of the adherent region. For this purpose, we developed a simple method to prepare adhered liposomes by simple electrostatic interactions between the membranes and by osmotic deflation. We found that the membrane tension of the adhered liposomes increases slightly with an increase in the area fraction of the adherent region. In addition, the lipid diffusion coefficient of the adhered liposomes is larger than that of isolated liposomes, which is consistent with the theoretical prediction. The analysis provides a framework to understand the correlation between cell adhesion and bio-membrane properties such as membrane tension and molecular diffusion.


Assuntos
Bicamadas Lipídicas/química , Lipossomos/química , Difusão , Membranas Artificiais , Osmose , Eletricidade Estática
5.
Int Heart J ; 61(2): 249-253, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32173706

RESUMO

Cryoballoon ablation is an established catheter-based approach to treat atrial fibrillation (AF). However, thromboembolic events cannot be avoided during cryoablation. There is little data regarding the blood coagulation status during freezing.The thrombin antithrombin complex (TAT) and prothrombin fragment 1+2 (F 1+2) of patient blood were measured during cryoballoon application when the cryoballoon temperature reached the nadir in 63 AF patients. TAT was also measured from porcine blood during cryoballoon freezing in 5 pigs.The TAT and F 1+2 increased from 6.60 ± 5.65 to 9.16 ± 7.28 ng/mL (P = 0.004) and from 279.6 ± 146.4 to 323.6 ± 169.1 pmol/L (P = 0.003) between the control and during freezing, respectively. The TAT increased from 0.46 to 0.87 ng/mL during freezing compared to that of pre-freezing (P < 0.05), and it returned to 0.39 ng/mL in 30 minutes after an intravenous edoxaban administration (N.S.).Dabigatran failed to exert sufficient anticoagulant effects during cryofreezing. In contrast, intravenous edoxaban seemed to provoke anticoagulation effects under extreme low temperature circumstances.


Assuntos
Antitrombinas/uso terapêutico , Criocirurgia/efeitos adversos , Dabigatrana/uso terapêutico , Piridinas/uso terapêutico , Tiazóis/uso terapêutico , Tromboembolia/etiologia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tromboembolia/prevenção & controle
6.
Plant Sci ; 293: 110417, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32081265

RESUMO

Chrysanthemum is a typical short day (SD) flowering plant that requires a longer night period than a critical minimum duration to successfully flower. We identified FLOWERING LOCUS T-LIKE 3 (FTL3) and ANTI-FLORIGENIC FT/TFL1 FAMILY PROTEIN (AFT) as a florigen and antiflorigen, respectively, in a wild diploid chrysanthemum (Chrysanthemum seticuspe). Expression of the genes that produce these proteins, CsFTL3 and CsAFT, is induced in the leaves under SD or a noninductive photoperiod, respectively, and the balance between them determines the progression of floral transition and anthesis. However, how CsFTL3 and CsAFT are regulated to define the critical night length for flowering in chrysanthemum is unclear. In this study, we focused on the circadian clock-related gene GIGANTEA (GI) of C. seticuspe (CsGI) and generated transgenic C. seticuspe plants overexpressing CsGI (CsGI-OX). Under a strongly inductive SD (8 L/16D) photoperiod, floral transition occurred at almost the same time in both wild-type and CsGI-OX plants. However, under a moderately inductive (12 L/12D) photoperiod, the floral transition in CsGI-OX plants was strongly suppressed, suggesting that the critical night length for flowering was lengthened for CsGI-OX plants. Under the 12 L/12D photoperiod, CsAFT was upregulated in CsGI-OX plants. Giving a night break (NB) 10 h after dusk was the most effective time to inhibit flowering in wild-type plants, while the most effective time for NB was extended to dawn (12 and 14 h after dusk) in CsGI-OX plants. In wild-type plants, a red-light pulse delivered 8 or 10 h after dusk induced maximal CsAFT expression, but the length of the time period over which CsAFT could be induced by red light was extended until subjective dawn in CsGI-OX plants. Therefore, CsGI-OX plants required a longer dark period to maintain lower levels of CsAFT, and their critical night length for flowering was thus lengthened. These results suggested that CsGI has an important role in the control of photoperiodic flowering through shaping the gate for CsAFT induction by light in chrysanthemum.


Assuntos
Chrysanthemum/metabolismo , Florígeno/metabolismo , Proteínas de Plantas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Chrysanthemum/genética , Relógios Circadianos/genética , Relógios Circadianos/fisiologia , Flores , Regulação da Expressão Gênica de Plantas , Luz , Fenótipo , Fotoperíodo , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/metabolismo
7.
J Phys Ther Sci ; 31(8): 670-674, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31528007

RESUMO

[Purpose] This study aimed to examine the impact of changing the drop vertical jump stance time on kinematic and kinetic parameters by ordering to high jump or quick jump for consistent stance time and a more accurate assessment of anterior cruciate ligament injury risk. [Participants and Methods] The participants were 20 healthy female students. The drop vertical jump was started by instructing the participants to stand on a 30-cm platform with both legs stationary. The task was performed while the participants were instructed to perform high jump or quick jump. [Results] Stance time was significantly shorter with quick jump than with high jump. Quick jump showed significantly higher knee abduction angles at initial contact and peak vertical ground reaction force, and lower hip flexion, knee flexion, and ankle dorsiflexion angles at the lowest point of the center of mass. Quick jump showed a significantly higher peak vertical ground reaction force. The knee abduction moment at initial contact was not significantly different between the 2 conditions. [Conclusion] Quick jump was better than high jump for making stance time consistent, and the differences in kinematic and kinetic characteristics by oral instructions should be considered when using drop vertical jump.

8.
Biotechnol Bioeng ; 116(11): 3136-3142, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31369146

RESUMO

Three-dimensional (3D) printers are attracting attention as a method for arranging and building cells in three dimensions. Bioprinting technology has potential in tissue engineering for the fabrication of scaffolds, cells, and tissues. However, these various printing technologies have limitations with respect to print resolution and due to the characteristics of bioink such as viscosity. We report a method for constructing of 3D tissues with a "microscopic painting device using a painting needle method" that, when used with the layer-by-layer (LbL) cell coating technique, replaces conventional methods. This method is a technique of attaching the high viscosity bioink to the painting needle tip and arranging it on a substrate, and can construct 3D tissues without damage to cells. Cell viability is the same before and after painting. We used this biofabrication device to construct 3D cardiac tissue (LbL-3D Heart) using human-induced pluripotent stem cell-derived cardiomyocytes. The constructed LbL-3D Heart chips had multiple layers with a thickness of 60 µm, a diameter of 1.1 mm, and showed synchronous beating (50-60 beats per min). The aforementioned device and method of 3D tissue construction can be applied to various kinds of tissue models and would be a useful tool for pharmaceutical applications.


Assuntos
Bioimpressão , Células-Tronco Pluripotentes Induzidas/metabolismo , Miocárdio/metabolismo , Agulhas , Impressão Tridimensional , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Miocárdio/citologia
9.
J Pharm Sci ; 108(2): 832-841, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30121316

RESUMO

The evaluation of subvisible particles, including protein aggregates, in therapeutic protein products has been of great interest for both pharmaceutical manufacturers and regulatory agencies. To date, the flow imaging (FI) method has emerged as a powerful tool instead of light obscuration (LO) due to the fact that (1) protein aggregates contain highly transparent particles and thereby escape detection by LO and (2) FI provides detailed morphological characteristics of subvisible particles. However, the FI method has not yet been standardized nor listed in any compendium. In an attempt to assess the applicability of the standardization of the FI method, we conducted a collaborative study using FI and LO instruments in a Japanese biopharmaceutical consortium. Three types of subvisible particle preparations were shared across 12 laboratories and analyzed for their sizes and counts. The results were compared between the methods (FI and LO), inter-laboratories, and inter-instruments (Micro Flow Imaging and FlowCam). We clarified the marked difference between the detectability of FI and LO when counting highly transparent protein aggregates in the preparations. Although FlowCam provided a relatively higher number of particles compared with MFI, consistent results were obtained using the instrument from the same manufacturer in all 3 samples.


Assuntos
Imunoglobulinas Intravenosas/química , Agregados Proteicos , Japão , Luz , Imagem Óptica , Tamanho da Partícula , Tecnologia Farmacêutica
10.
Sensors (Basel) ; 18(12)2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30544609

RESUMO

Land cover classification and investigation of temporal changes are considered to be common applications of remote sensing. Water/non-water region estimation is one of the most fundamental classification tasks, analyzing the occurrence of water on the Earth's surface. However, common remote sensing practices such as thresholding, spectral analysis, and statistical approaches are not sufficient to produce a globally adaptable water classification. The aim of this study is to develop a formula with automatically derived tuning parameters using perceptron neural networks for water/non-water region estimation, which we call the Perceptron-Derived Water Formula (PDWF), using Landsat-8 images. Water/non-water region estimates derived from PDWF were compared with three different approaches-Modified Normalized Difference Water Index (MNDWI), Automatic Water Extraction Index (AWEI), and Deep Convolutional Neural Network-using various case studies. Our proposed method outperforms all three approaches, showing a significant improvement in water/non-water region estimation. PDWF performance is consistently better even in cases of challenging conditions such as low reflectance due to hill shadows, building-shadows, and dark soils. Moreover, our study implemented a sunglint correction to adapt water/non-water region estimation over sunglint-affected pixels.

11.
J Phys Ther Sci ; 29(10): 1860-1864, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29184307

RESUMO

[Purpose] The purpose of this study was to investigate whether transcutaneous electrical nerve stimulation simultaneously combined with local heat and cold applications enhances pain relief compared with transcutaneous electrical nerve stimulation alone in patients with knee osteoarthritis. [Subjects and Methods] Fourty-five patients with knee osteoarthritis participated in this study. They were randomly assigned to the following three interventions: transcutaneous electrical nerve stimulation simultaneously combined with local heat using a hot pack; combined with local cold using a cold pack; and transcutaneous electrical nerve stimulation alone. In each intervention, the knee pain level during walking and standing up from a chair, as well as dynamic balance and gait ability were evaluated immediately before and after a single intervention using the visual analogue scale and the timed up & go test, respectively. [Results] A significant improvement in dynamic balance and gait ability was only observed immediately after transcutaneous electrical nerve stimulation simultaneously combined with local heat application, although the degree of pain relief during standing and walking were comparable among the three interventions. [Conclusion] These results suggest that transcutaneous electrical nerve stimulation simultaneously combined with local heat application can immediately improve not only knee pain during standing and walking but also dynamic balance and gait ability in patients with knee osteoarthritis.

12.
Plant Sci ; 259: 86-93, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28483056

RESUMO

A wide variety of physiological processes including flowering are controlled by the circadian clock in plants. In Arabidopsis, LATE ELONGATED HYPOCOTYL (LHY) and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) constitute the central oscillator, and their gain of function and loss of function disrupt the circadian clock and affect flowering time through FLOWERING LOCUS T (FT), a gene encoding a florigen. Chrysanthemum is a typical short-day (SD) plant and responds to shortening of day length by the transition from the vegetative to reproductive phase. We identified FLOWERING LOCUS T-LIKE 3 (FTL3) and ANTI-FLORIGENIC FT/TFL1 FAMILY PROTEIN (AFT) as a florigen and antiflorigen, respectively, in a wild diploid chrysanthemum (Chrysanthemum seticuspe f. boreale). CsFTL3 and CsAFT are induced under SD or a noninductive photoperiod, respectively, and their balance determines the floral transition and anthesis. Meanwhile, the time-keeping mechanism that regulates the photoperiodic flowering in chrysanthemum is poorly understood. Here, we focused on a LHY/CCA1-like gene called CsLHY in chrysanthemum. We fused CsLHY to a gene encoding short transcriptional repressor domain (SRDX) and constitutively expressed it in chrysanthemum. Although the transcription of clock-related genes was conditionally affected, circadian rhythm was not completely disrupted in CsLHY-SRDX transgenic plants. These plants formed almost the same number of leaves before floral transition under SD and long-day conditions. Thus, CsLHY-SRDX chrysanthemum showed photoperiod-insensitive floral transition, but further development of the capitulum was arrested, and anthesis was not observed. Simultaneously with the flowering phenotype, CsFTL3 and CsAFT were downregulated in CsLHY-SRDX transgenic plants. These results suggest that CsLHY-SRDX affects CsFTL3 and CsAFT expression and causes photoperiod-insensitive floral transition without a severe defect in the circadian clock.


Assuntos
Chrysanthemum/metabolismo , Flores/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Chrysanthemum/genética , Chrysanthemum/fisiologia , Ritmo Circadiano/genética , Ritmo Circadiano/fisiologia , Florígeno/metabolismo , Flores/genética , Flores/fisiologia , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
13.
J Phys Ther Sci ; 29(2): 187-190, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28265136

RESUMO

[Purpose] To investigate the features of backward walking in stroke patients with hemiplegia by focusing on the joint movements and moments of the paretic side, walking speed, stride length, and cadence. [Subjects and Methods] Nine stroke patients performed forward walking and backward walking along a 5-m walkway. Walking speed and stride length were self-selected. Movements were measured using a three-dimensional motion analysis system and a force plate. One walking cycle of the paretic side was analyzed. [Results] Walking speed, stride length, and cadence were significantly lower in backward walking than in forward walking. Peak hip extension was significantly lower in backward walking and peak hip flexion moment, knee extension moment, and ankle dorsiflexion and plantar flexion moments were lower in backward walking. [Conclusion] Unlike forward walking, backward walking requires conscious hip joint extension. Conscious extension of the hip joint is hard for stroke patients with hemiplegia. Therefore, the range of hip joint movement declined in backward walking, and walking speed and stride length also declined. The peak ankle plantar flexion moment was significantly lower in backward walking than in forward walking, and it was hard to generate propulsion power in backward walking. These difficulties also affected the walking speed.

14.
Proc Natl Acad Sci U S A ; 110(42): 17137-42, 2013 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24082137

RESUMO

Photoperiodic floral induction has had a significant impact on the agricultural and horticultural industries. Changes in day length are perceived in leaves, which synthesize systemic flowering inducers (florigens) and inhibitors (antiflorigens) that determine floral initiation at the shoot apex. Recently, FLOWERING LOCUS T (FT) was found to be a florigen; however, the identity of the corresponding antiflorigen remains to be elucidated. Here, we report the identification of an antiflorigen gene, Anti-florigenic FT/TFL1 family protein (AFT), from a wild chrysanthemum (Chrysanthemum seticuspe) whose expression is mainly induced in leaves under noninductive conditions. Gain- and loss-of-function analyses demonstrated that CsAFT acts systemically to inhibit flowering and plays a predominant role in the obligate photoperiodic response. A transient gene expression assay indicated that CsAFT inhibits flowering by directly antagonizing the flower-inductive activity of CsFTL3, a C. seticuspe ortholog of FT, through interaction with CsFDL1, a basic leucine zipper (bZIP) transcription factor FD homolog of Arabidopsis. Induction of CsAFT was triggered by the coincidence of phytochrome signals with the photosensitive phase set by the dusk signal; flowering occurred only when night length exceeded the photosensitive phase for CsAFT induction. Thus, the gated antiflorigen production system, a phytochrome-mediated response to light, determines obligate photoperiodic flowering response in chrysanthemums, which enables their year-round commercial production by artificial lighting.


Assuntos
Chrysanthemum/metabolismo , Flores/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Fotoperíodo , Proteínas de Plantas/biossíntese , Transativadores/biossíntese , Sequência de Aminoácidos , Chrysanthemum/genética , Flores/genética , Loci Gênicos/fisiologia , Dados de Sequência Molecular , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Homologia de Sequência de Aminoácidos , Transativadores/genética
15.
Semin Cell Dev Biol ; 24(4): 308-13, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23499790

RESUMO

The actin cytoskeleton is critically involved in a variety of cell functions. The Arp2/3 complex mediates branching of filamentous actin. The members of the Wiskott-Aldrich syndrome protein (WASP) family are major regulators of the complex. As such, the family proteins are also involved in numerous aspects of cell biology. In this short review, we first define the expanding WASP family. Next, we compare the domain structure of the members, and explain the known or proposed functions of each domain or region. Finally, we demonstrate the well-characterized roles of the proteins in specific cellular functions.


Assuntos
Proteínas do Citoesqueleto/fisiologia , Família de Proteínas da Síndrome de Wiskott-Aldrich/fisiologia , Citoesqueleto de Actina/metabolismo , Citoesqueleto de Actina/fisiologia , Animais , Proteínas do Citoesqueleto/metabolismo , Humanos , Família de Proteínas da Síndrome de Wiskott-Aldrich/metabolismo
16.
Cell Stem Cell ; 12(5): 546-58, 2013 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-23523177

RESUMO

Mucosal-associated invariant T (MAIT) cells play an important physiological role in host pathogen defense and may also be involved in inflammatory disorders and multiple sclerosis. The rarity and inefficient expansion of these cells have hampered detailed analysis and application. Here, we report an induced pluripotent stem cell (iPSC)-based reprogramming approach for the expansion of functional MAIT cells. We found that human MAIT cells can be reprogrammed into iPSCs using a Sendai virus harboring standard reprogramming factors. Under T cell-permissive conditions, these iPSCs efficiently redifferentiate into MAIT-like lymphocytes expressing the T cell receptor Vα7.2, CD161, and interleukin-18 receptor chain α. Upon incubation with bacteria-fed monocytes, the derived MAIT cells show enhanced production of a broad range of cytokines. Following adoptive transfer into immunocompromised mice, these cells migrate to the bone marrow, liver, spleen, and intestine and protect against Mycobacterium abscessus. Our findings pave the way for further functional analysis of MAIT cells and determination of their therapeutic potential.


Assuntos
Diferenciação Celular , Reprogramação Celular , Células-Tronco Pluripotentes Induzidas/citologia , Mucosa/citologia , Linfócitos T/citologia , Animais , Diferenciação Celular/genética , Proliferação de Células , Feminino , Sangue Fetal/citologia , Regulação da Expressão Gênica , Humanos , Hospedeiro Imunocomprometido/imunologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Camundongos SCID , Mucosa/metabolismo , Mycobacterium/imunologia , Infecções por Mycobacterium/imunologia , Infecções por Mycobacterium/prevenção & controle , Linfócitos T/metabolismo
17.
J Plast Surg Hand Surg ; 46(5): 374-6, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22747356

RESUMO

We present the case of a 67-year-old woman with scleroderma who had progressive necrosis of the finger together with severe pain 20 years after harvesting of a radial forearm flap. After reconstruction of the radial artery the ulceration of her right middle finger healed spontaneously within a month, and the pain disappeared.


Assuntos
Dedos/irrigação sanguínea , Dedos/patologia , Isquemia/etiologia , Escleroderma Sistêmico/cirurgia , Retalhos Cirúrgicos/efeitos adversos , Idoso , Amputação Cirúrgica , Anastomose Cirúrgica , Feminino , Dedos/cirurgia , Humanos , Isquemia/cirurgia , Necrose , Artéria Radial , Veia Safena/transplante , Retalhos Cirúrgicos/irrigação sanguínea
18.
J Plant Physiol ; 169(18): 1789-96, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-22840324

RESUMO

Chrysanthemum (Chrysanthemum morifolium) is a short-day plant, which flowers when the night length is longer than a critical minimum. Flowering is effectively inhibited when the required long-night phase is interrupted by a short period of exposure to red light (night break; NB). The reversal of this inhibition by subsequent exposure to far-red (FR) light indicates the involvement of phytochromes in the flowering response. Here, we elucidated the role of light quality in photoperiodic regulation of chrysanthemum flowering, by applying a range of different conditions. Flowering was consistently observed under short days with white light (W-SD), SD with monochromatic red light (R-SD), or SD with monochromatic blue light (B-SD). For W-SD, NB with monochromatic red light (NB-R) was most effective in inhibiting flowering, while NB with monochromatic blue light (NB-B) and NB with far-red light (NB-FR) caused little inhibition. In contrast, for B-SD, flowering was strongly inhibited by NB-B and NB-FR. However, when B-SD was supplemented with monochromatic red light (B+R-SD), no inhibition by NB-B and NB-FR was observed. Furthermore, the inhibitory effect of NB-B following B-SD was partially reversed by subsequent exposure to a FR light pulse. The conditions B-SD/NB-B (no flowering) and B+R-SD/NB-B (flowering) similarly affected the expression of circadian clock-related genes. However, only the former combination suppressed expression of the chrysanthemum orthologue of FLOWERING LOCUS T (CmFTL3). Our results suggest the involvement of at least 2 distinct phytochrome responses in the flowering response of chrysanthemum. Furthermore, it appears that the light quality supplied during the daily photoperiod affects the light quality required for effective NB.


Assuntos
Chrysanthemum/efeitos da radiação , Flores/efeitos da radiação , Luz , Fotoperíodo , Fitocromo/metabolismo , Folhas de Planta/efeitos da radiação , Chrysanthemum/genética , Chrysanthemum/fisiologia , Relógios Circadianos , DNA Complementar , Escuridão , Flores/genética , Flores/fisiologia , Regulação da Expressão Gênica de Plantas , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais
19.
J Exp Bot ; 63(3): 1461-77, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22140240

RESUMO

Chrysanthemum is a typical short-day (SD) plant that responds to shortening daylength during the transition from the vegetative to the reproductive phase. FLOWERING LOCUS T (FT)/Heading date 3a (Hd3a) plays a pivotal role in the induction of phase transition and is proposed to encode a florigen. Three FT-like genes were isolated from Chrysanthemum seticuspe (Maxim.) Hand.-Mazz. f. boreale (Makino) H. Ohashi & Yonek, a wild diploid chrysanthemum: CsFTL1, CsFTL2, and CsFTL3. The organ-specific expression patterns of the three genes were similar: they were all expressed mainly in the leaves. However, their response to daylength differed in that under SD (floral-inductive) conditions, the expression of CsFTL1 and CsFTL2 was down-regulated, whereas that of CsFTL3 was up-regulated. CsFTL3 had the potential to induce early flowering since its overexpression in chrysanthemum could induce flowering under non-inductive conditions. CsFTL3-dependent graft-transmissible signals partially substituted for SD stimuli in chrysanthemum. The CsFTL3 expression levels in the two C. seticuspe accessions that differed in their critical daylengths for flowering closely coincided with the flowering response. The CsFTL3 expression levels in the leaves were higher under floral-inductive photoperiods than under non-inductive conditions in both the accessions, with the induction of floral integrator and/or floral meristem identity genes occurring in the shoot apexes. Taken together, these results indicate that the gene product of CsFTL3 is a key regulator of photoperiodic flowering in chrysanthemums.


Assuntos
Chrysanthemum/metabolismo , Chrysanthemum/fisiologia , Flores/metabolismo , Flores/fisiologia , Fotoperíodo , Proteínas de Plantas/metabolismo , Chrysanthemum/genética , Flores/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética
20.
Plant Signal Behav ; 6(8): 1162-71, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21822060

RESUMO

Photoperiodic flowering in Arabidopsis is controlled not only by floral activators such as GI, CO, and FT, but also by repressors such as SVP and FLC. Double mutations in LHY and CCA1 (lhy;cca1) accelerated flowering under short days, mainly by the GI-CO dependent pathway. In contrast, lhy;cca1 showed delayed flowering under continuous light (LL), probably due to the GI-CO independent pathway. This late-flowering phenotype was suppressed by svp, flc, and elf3. However, how SVP, FLC, and ELF3 mediate LHY/CCA1 and flowering time is not fully understood. We found that lhy;cca1 exhibited short hypocotyls and petioles under LL, but the molecular mechanism for these effects has not been elucidated. To address these questions, we performed a screen for mutations that suppress either or both of the lhy;cca1 phenotypes under LL, using two different approaches. We identified two novel mutations, a dominant (del1) and a recessive (phyB-2511) allele of phyB. The flowering times of single mutants of three phyB alleles, hy3-1, del1, and phyB-2511, are almost the same and earlier than those of wild-type plants. A similar level of acceleration of flowering time was observed in all three phyB mutants tested when combined with the late-flowering mutations co-2 and SVPox. However, the effect of phyB-2511 on lhy;cca1 was different from those by hy3-1 or del1. svp-3 did not strongly enhance the early-flowering phenotypes of phyB-2511 or del1. These results suggest that light signaling via PhyB may affect factors downstream of the clock proteins, controlling flowering time and organ elongation. phyB mutations with different levels of effects on lhy;cca1-dependent late flowering would be useful to determine a specific role for PHYB in the flowering pathway controlled by lhy;cca1 under LL.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Flores/crescimento & desenvolvimento , Luz , Fitocromo B/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Ritmo Circadiano , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica de Plantas , Hipocótilo/crescimento & desenvolvimento , Mutagênese , Mutação , Fenótipo , Fotoperíodo , Fitocromo B/genética , RNA de Plantas/genética , Fatores de Transcrição/genética
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