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1.
J Clin Nurs ; 32(17-18): 6474-6484, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36899476

RESUMO

AIMS AND OBJECTIVES: To develop a simple and reliable assessment tool for predicting falls in acute care settings. BACKGROUND: Falling injures patients, lengthens hospital stay and leads to the wastage of financial and medical resources. Although there are many potential predictors for falls, a simple and reliable assessment tool is practically necessary in acute care settings. DESIGN: A retrospective cohort study. METHODS: The current study was conducted for participants who were admitted to a teaching hospital in Japan. Fall risk was assessed by the modified Japanese Nursing Association Fall Risk Assessment Tool consisting of 50 variables. To create a more convenient model, variables were first limited to 26 variables and then selected by stepwise logistic regression analysis. Models were derived and validated by dividing the whole dataset into a 7:3 ratio. Sensitivity, specificity, and area under the curve for the receiver-operating characteristic curve were evaluated. This study was conducted according to the STROBE guideline. RESULTS: Six variables including age > 65 years, impaired extremities, muscle weakness, requiring mobility assistance, unstable gait and psychotropics were chosen in a stepwise selection. A model using these six variables with a cut-off point of 2 with one point for each item, was developed. Sensitivity and specificity >70% and area under the curve >.78 were observed in the validation dataset. CONCLUSIONS: We developed a simple and reliable six-item model to predict patients at high risk of falling in acute care settings. RELEVANCE TO CLINICAL PRACTICE: The model has also been verified to perform well with non-random partitioning by time and future research is expected to make it useful in acute care settings and clinical practice. PATIENT OR PUBLIC CONTRIBUTION: Patients participated in the study on an opt-out basis, contributing to the development of a simple predictive model for fall prevention during hospitalisation that can be shared with medical staff and patients in the future.


Assuntos
Hospitalização , Humanos , Idoso , Estudos Retrospectivos , Medição de Risco , Sensibilidade e Especificidade , Tempo de Internação
2.
J Clin Nurs ; 32(3-4): 494-505, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35224808

RESUMO

BACKGROUND AND AIMS: Falling generally injures patients, lengthens hospital stays and leads to the wastage of financial and medical resources. Although falls can occur at any stage after hospital admission, there are no studies that characterise falls with length of hospital stay in acute care settings. This study aims to clarify risk stratification of early and late falls in acute care settings. METHODS: A retrospective cohort study was conducted for participants who were admitted to a teaching hospital in Japan. Patients' falls were divided into two groups based on the median of the fall date (day 10). Considering a 70/30 split, the logistic regression model was used to extract independent predictors for early and late falls for nine risk variables based on exploratory analysis among 26 items selected from the modified Japanese Nursing Association Fall Risk Assessment Tool, and risk models were validated. This study was conducted according to the STROBE guideline. RESULTS: Of the 10,975 patients admitted, 87 and 90 with early and late falls, respectively, were identified. The five significant risk factors extracted for early falls were fall history, muscle weakness, impaired understanding, use of psychotropics and the personality trait of 'doing everything on one's own'; risk factors identified for late falls were being older than 65 years, impaired extremities and unstable gait, in addition to muscle weakness. Using these variables for early and late falls in the validation cohort, the concordance indices of the risk models were both over 0.80. CONCLUSIONS: By separately extracting risk factors for early and late falls in an acute care hospital setting, this study shed light on the characteristics of the respective types of falls. RELEVANT TO CLINICAL PRACTICE: As the risk factors of falls vary according to the length of hospitalisation, specific preventive care can be implemented to avoid fall incidents.


Assuntos
Hospitalização , Humanos , Estudos Retrospectivos , Fatores de Risco , Medição de Risco
3.
PLoS One ; 17(11): e0277174, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36355760

RESUMO

The COVID-19 pandemic has been affecting the mental health of hospital workers. During the prolonged pandemic, hospital workers may experience much more severe psychological distress, leading to an increased risk of suicide. This study aimed to investigate changes in psychological effects on hospital workers over 12 months from the beginning of the pandemic and clarify factors associated with psychological distress and suicide-related ideation 1-year after the pandemic's beginning. These repeated, cross-sectional surveys collected demographic, mental health, and stress-related data from workers in 2 hospitals in Yokohama, Japan. The first survey, conducted in March-April 2020, contained the 12-item General Health Questionnaire (GHQ-12) assessing general distress and the Impact of Event Scale-Revised (IES-R) assessing event-related distress. In the second survey in March 2021, hospital workers at the same two hospitals were reassessed using the same questionnaire, and Item 9 of the Patient Health Questionnaire (PHQ-9) was added to assess their suicide-related ideation. The findings of the first and second surveys revealed that the average score of GHQ-12 (3.08 and 3.73, respectively), the IES-R total score (6.8 and 12.12, respectively), and the prevalence rates of severe general distress (35.0% and 44.0%, respectively) and severe event-related distress (7.0% and 17.1%, respectively) deteriorated. The second survey showed that 8.6% of the hospital workers were experiencing suicide-related ideation. Both the general and event-related distress were associated with suicide-related ideation. In these surveys, mental health outcomes among the hospital workers deteriorated over one year from the pandemic's beginning, and their severe psychological distress was the risk factor for the suicide-related ideation. Further studies are needed to compare the psychological effects on hospital workers during and after the prolonged pandemic and to explore appropriate measures to support hospital workers' mental health.


Assuntos
COVID-19 , Angústia Psicológica , Suicídio , Humanos , COVID-19/epidemiologia , Pandemias , Estudos Transversais , Estresse Psicológico/epidemiologia , Estresse Psicológico/psicologia , Inquéritos e Questionários , Hospitais
4.
J Phys Ther Sci ; 34(4): 290-296, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35400838

RESUMO

[Purpose] This study aimed to clarify the effect of an adaptation of a deviation of the visual field in three axes on spatial cognition in patients with unilateral spatial neglect and distorted spatial perception in three dimensions. [Participants and Methods] Fifteen patients with cerebrovascular disease and symptoms of unilateral spatial neglect were included. Forty-eight pointing movements with a camera attached to a head-mounted display changed in three axes were compared with the control condition in which the camera was deflected only in the horizontal plane as with the prism adaptation. The main outcome measures were subjective straight-ahead pointing, line bisection, line cancellation, and star cancellation. [Results] The head-mounted display adaptive therapy was performed under conditions that varied in all three axes. The results indicated that it was possible to deflect the subjective straight-ahead pointing position to the lower left direction. [Conclusion] In contrast to the prism adaptation, which deflects the visual field in a single axis in the horizontal plane, the tri-axial adaptation corrected the median cognition in the left-right direction as well as the cognition of the body center, including the vertical direction.

5.
Vaccine ; 40(19): 2652-2655, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35370020

RESUMO

To evaluate vaccine-induced humoral and cell-mediated immunity at 6 months after completion of two doses of BNT162b2 vaccination, immunoglobulin G against SARS-CoV-2 spike protein (SP IgG), 50% neutralizing antibody (NT50), and spot-forming cell (SFC) counts were evaluated by interferon-γ releasing ELISpot assay of 98 healthy subjects (median age, 43 years). The geometric mean titers of SP IgG and NT50 decreased from 95.2 (95% confidence interval (CI) 79.8-113.4) to 5.7 (95% CI 4.9-6.7) and from 680.4 (588.0-787.2) to 130.4 (95% CI 104.2-163.1), respectively, at 3 weeks and 6 months after the vaccination. SP IgG titer was negatively correlated with age and alcohol consumption. Spot-forming cell counts at 6 months did not correlate with age, gender, and other parameters of the patients. SP IgG, NT50, and SFC titers were elevated in the breakthrough infected subjects. Although the levels of vaccine-induced antibodies dramatically declined at 6 months after vaccination, a certain degree of cellular immunity was observed irrespective of the age.


Assuntos
COVID-19 , SARS-CoV-2 , Adulto , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacina BNT162 , COVID-19/prevenção & controle , Humanos , Imunidade Celular , Imunidade Humoral , Imunoglobulina G , Glicoproteína da Espícula de Coronavírus , Vacinação
6.
J Infect Chemother ; 28(2): 273-278, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34857462

RESUMO

BACKGROUND: Levels of 50% neutralizing titer (NT50) reflect the a vaccine-induced humoral immunity after the vaccination against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Measurements of NT50 are difficult to implement in large quantities. A high-throughput laboratory test is expected for determining the level of herd immunity against SARS-CoV-2. METHODS: We analyzed samples from 168 Japanese healthcare workers who had completed two doses of the BNT162b2 vaccine. We analyzed immunoglobulin G (IgG) index values against spike protein (SP) using automated chemiluminescent enzyme immunoassay system AIA-CL and analyzed the background factors affecting antibody titer. SP IgG index was compared with 50% neutralization titers. RESULTS: The median SP IgG index values of the subjects (mean age = 43 years; 75% female) were 0.1, 1.35, 60.80, and 97.35 before and at 2, 4, and 6 weeks after the first dose, respectively. At 4 and 6 weeks after the first dose, SP IgG titers were found to have positive correlation with NT50 titer (r = 0.7535 in 4 weeks; r = 0.4376 in 6 weeks). Proportions of the SP IgG index values against the Alpha, Beta, Gamma, and Delta variants compared with the original strain were 2.029, 0.544, 1.017, and 0.6096 respectively. Older age was associated with lower SP IgG titer index 6 weeks after the first dose. CONCLUSIONS: SP IgG index values were rised at 3 weeks after two doses of BNT162b2 vaccination and have positive correlation with NT50. SP IgG index values were lower in the older individuals and against Beta and Delta strain.


Assuntos
Vacina BNT162 , COVID-19 , Adulto , Idoso , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra COVID-19 , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , SARS-CoV-2 , Vacinação
8.
Neurocase ; 27(6): 447-451, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34927563

RESUMO

Here, we developed a method that randomly generates balloons in the left-right, up-down, and near-far spaces on a monitor using a head-mounted display. In this study, we evaluated a lack of stimulus-driven attention case that was undetected by conventional assessments such as the Behavioral Inattention Test. We could identify mild neglect with our virtual reality method, as later confirmed using the Catherine Bergego scale. After repeated practice under a tilted background space condition, the patient demonstrated a reduction in the time needed to perceive the appearing balloons, suggesting a therapeutic effect.


Assuntos
Transtornos da Percepção , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Realidade Virtual , Atividades Cotidianas , Humanos , Transtornos da Percepção/diagnóstico , Transtornos da Percepção/etiologia , Transtornos da Percepção/terapia , Percepção Espacial , Reabilitação do Acidente Vascular Cerebral/métodos
9.
PLoS One ; 16(1): e0245294, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33428676

RESUMO

The aim of the present study was to investigate the psychological effects of the COVID-19 outbreak and associated factors on hospital workers at the beginning of the outbreak with a large disease cluster on the Diamond Princess cruise ship. This cross-sectional, survey-based study collected demographic data, mental health measurements, and stress-related questionnaires from workers in 2 hospitals in Yokohama, Japan, from March 23, 2020, to April 6, 2020. The prevalence rates of general psychological distress and event-related distress were assessed using the 12-item General Health Questionnaire (GHQ-12) and the 22-item Impact of Event Scale-Revised (IES-R), respectively. Exploratory factor analysis was conducted on the 26-item stress-related questionnaires. Multivariable logistic regression analysis was performed to identify factors associated with mental health outcomes for workers both at high- and low-risk for infection of COVID-19. A questionnaire was distributed to 4133 hospital workers, and 2697 (65.3%) valid questionnaires were used for analyses. Overall, 536 (20.0%) were high-risk workers, 944 (35.0%) of all hospital workers showed general distress, and 189 (7.0%) demonstrated event-related distress. Multivariable logistic regression analyses revealed that 'Feeling of being isolated and discriminated' was associated with both the general and event-related distress for both the high- and low-risk workers. In this survey, not only high-risk workers but also low-risk workers in the hospitals admitting COVID-19 patients reported experiencing psychological distress at the beginning of the outbreak.


Assuntos
COVID-19/epidemiologia , Hotspot de Doença , Recursos Humanos em Hospital/psicologia , Angústia Psicológica , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Saúde Mental , Pessoa de Meia-Idade , Navios , Adulto Jovem
10.
Amino Acids ; 52(11-12): 1505-1519, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33180203

RESUMO

Plasma glutamate concentrations are constant despite dynamic changes in diets. Most likely, virtually all the dietary glutamate is metabolized in the gut. The present study investigated permeability and metabolism of dietary glutamate in a Caco-2 intestinal epithelial cell layer model by tracing the fate of [U-13C] or [15N]glutamate added to the apical medium. For comparison, several other labelled essential and non-essential amino acids were tested as well. Almost all the labelled glutamate in the apical medium (98% and 96% at 24 h of the culture, respectively) was incorporated in the cell layer, while it barely appeared at the basolateral side, indicating an almost complete utilization of glutamate. Indeed, the 13C was incorporated into alanine, proline, ornithine, and glutamine, and the 15N was incorporated into alanine, glutamine, ornithine, proline, branched chain amino acids and also found as ammonia indicative of oxidation. In contrast, substantial apical-to-basolateral transport of amino acids (8-85% of uptake) other than glutamate and aspartate was evident in studies using amino acid tracers labelled with 13C, 15N or D. These results suggest that the intestinal epithelial cell monolayer utilizes dietary glutamate which adds to maintaining glutamate homeostasis in the body.


Assuntos
Aminoácidos/metabolismo , Ácido Glutâmico/metabolismo , Mucosa Intestinal/metabolismo , Alanina/metabolismo , Ácido Aspártico/metabolismo , Células CACO-2 , Dieta , Células Epiteliais/metabolismo , Glutamina/metabolismo , Humanos , Permeabilidade/efeitos dos fármacos
11.
Toxicol Rep ; 7: 1233-1241, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32995298

RESUMO

Wolffia is a genus of protein-rich aquatic plants. Mankai, a cultivated strain of Wolffia globosa, contains more than 40 % protein based on dry matter evaluation. Furthermore, Mankai is nutritionally excellent as a food material, and is expected to be applicable to various products as a substitute for animal protein. A battery of toxicological studies was conducted on the dried product of Mankai (Dry Mankai), with the expectation to utilize it as a raw material for food applications. Dry Mankai was not genotoxic in a bacterial reverse mutation test and in vitro micronucleus assay. In the subchronic toxicity study, rats were provided Dry Mankai in the diet at levels of 0 %, 5 %, 10 %, or 20 % (w/w), equivalent to 0, 3.18, 6.49, and 13.16 g/kg/day for males and 0, 3.58, 7.42, and 15.03 g/kg/day for females, respectively. No adverse effects that could be attributable to treatment were observed in clinical observations, body weight, food consumption, ophthalmology, hematology and blood chemistry, urinalysis, and macroscopic and microscopic findings. According to the repeated-dose study in rats, the no observed adverse effect level of Dry Mankai was 20 % (w/w) for both sexes (13.16 and 15.03 g/kg/day for males and females, respectively).

12.
Prog Rehabil Med ; 4: 20190008, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32789255

RESUMO

OBJECTIVE: The purpose of this study was to verify the effect on spatial perception in healthy young subjects of an unconscious leftward optical shift created by a head-mounted display (HMD) with an offset camera. METHODS: We recruited 40 healthy right-handed adults who were divided into four groups according to the hand used in the tests and the visual direction displayed by the HMD (centered or 10° left). Each of the four groups (n = 10) undertook line bisection tasks across four combinations of variables: using a finger/stick or a mouse to point at a touch panel located 60 or 120 cm away from the subject. RESULTS: According to the results, regardless of the hand used, when the index finger or a stick was used (reaching condition), the line bisection point was displaced significantly to the left of the center. Additionally, a major left-displacement trend was observed in the short-distance reaching task, which did not require the use of a stick. In contrast, the long-distance task required a stick to be used, and the left displacements were all smaller than those for the short-distance tasks that used the index finger. CONCLUSION: This finding may be explained by the subjects having sufficient experience coordinating hand and eye movements in the condition where they used their dominant hand and reached with their own arms without using a stick.

13.
RSC Adv ; 8(47): 26461-26468, 2018 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-35541069

RESUMO

Peptide amphiphiles are one of the most promising materials in the biomedical field, so much effort has been devoted to characterizing the mechanism of their self-assembly and thermosensitive gelation. In this work, vapor pressure osmometry measurements were carried out to parameterize the thermosensitivity of interactions between peptide amphiphiles in an aqueous solution. The osmometry measurement verified that the peptides became more hydrophobic as temperature increased, which was quantitatively described with the Flory-Huggins χ parameter. Thereafter, a coarse-grained molecular model was used to simulate peptide amphiphiles dissolved in an aqueous solution. The temperature sensitive coarse-grained parameter a HW, which is the repulsive force between the hydrophilic head of the peptide amphiphile and water was estimated from the aforementioned experimentally obtained χ. Furthermore, the effects of concentration and temperature on the self-assembly behavior of peptide amphiphiles were quantitatively studied by dissipative particle dynamics. The simulation results revealed that a HW plays an important role in self-assembly characteristics and in the resulting microstructure of the peptide amphiphiles, which coincides with previous experimental and computational findings. The methodology in quantitatively linking the coarse-grained parameter from experiment and theory provides a sensible foundation for bridging future simulation studies with experimental work on macromolecules.

14.
Dalton Trans ; 42(31): 11128-35, 2013 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-23801412

RESUMO

The synthesis of zeolitic imidazolate framework-8 (ZIF-8) films in an aqueous system was achieved. ZIF-8 films with controllable thickness were successfully grown on a modified substrate at room temperature. The 3-(2-imidazolin-1-yl)propyltriethoxysilane (IPTES) was used to first form a pseudo-surface of ZIF-8 on a glass substrate, followed by layer-by-layer growth. The film thickness of ZIF-8 was controlled within the range from 220 to 640 nm per growth cycle by changing the reactivity of the zinc source. Notably, the use of a preorganized zinc source led to drastic changes in the formation rate of ZIF-8. The use of a low-reactivity growth solution containing zinc acetate thus allowed the preparation of dense ZIF-8 films.

15.
Gan To Kagaku Ryoho ; 39(4): 577-82, 2012 Apr.
Artigo em Japonês | MEDLINE | ID: mdl-22504681

RESUMO

The efficacy of local steroid injection on the extravasation of vesicant anticancer drugs is controversial. In this study, the efficacy of local steroid injection was evaluated macroscopically and histologically in the extravasation models of doxorubicin (DXR), vinorelbine (VNR), and paclitaxel (PTX)in rats. Macroscopically, gross skin lesions were reduced by local steroid injections in rats treated with DXR and VNR. PTX did not cause gross skin lesions in most rats regardless of local steroid injection. Histologically, however, DXR, VNR, and PTX all induced deep tissue lesions such as edema, inflammation, and necrosis. Therefore, the effect of local steroid injection seemed to be minimal. In particular, DXR induced extensive necrosis in the subcutaneous and muscle tissues. VNR-induced skin lesions were milder than those induced by DXR, but had full thickness. Lesions caused by PTX were the mildest. These findings suggest that although local steroid injections could serve a primary role in diluting anticancer drugs and reducing gross skin lesions by their anti-inflammatory effect, they have less ability for suppressing deep-tissue lesions developing over time.


Assuntos
Antineoplásicos/efeitos adversos , Extravasamento de Materiais Terapêuticos e Diagnósticos/tratamento farmacológico , Esteroides/uso terapêutico , Animais , Injeções Intradérmicas , Masculino , Ratos , Ratos Wistar , Esteroides/administração & dosagem
16.
J Phys Chem B ; 116(1): 240-3, 2012 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-22136575

RESUMO

Peptide amphiphile molecules (PA) are remarkably versatile and useful as building blocks for construction of complex supramolecular structures in a bottom-up fashion. Worm-like micelles of PA have been demonstrated to have successful application to creation of synthetic extracellular matrix materials for tissue engineering and regenerative medicine. However, the pathway of the self-assembly process of the PA worm-like micelle has not been fully characterized or understood. This work analyzes the self-assembly process leading to worm-like micelle formation in our designed PA with small-angle neutron scattering and atomic force microscopy. The experimental results demonstrate the existence of transient spherical micelles in the early stage of the process and subsequent micelle chain elongation by attachment of spherical micelles to the end of growing cylindrical micelles to form worm-like micelles in a process mimicking chain-growth polymerization.


Assuntos
Micelas , Peptídeos/química , Microscopia de Força Atômica , Difração de Nêutrons , Medicina Regenerativa , Espalhamento a Baixo Ângulo , Engenharia Tecidual
17.
J Vet Med Sci ; 73(5): 649-54, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21206175

RESUMO

Probiotic strains have been reported to have the ability to control allergic and inflammatory diseases. In this study, we studied the inhibitory effect of Bacillus subtilis (natto) (BS) on atopic dermatitis. The effects of continuous oral administration of BS for 4 weeks on the development of atopic dermatitis induced by Dermatophagoides farinae body antigen (DF) in NC/Nga (NC) mice were evaluated using 4 groups of mice: group (Gp) DF, DF(+) with no administration of bacteria (n=3); Gp DF/BS, DF(+) and BS(+) (n=5); and Gp PBS, DF(-) with no administration of bacteria (n=3). The mice were gavaged with 1.2 × 10(17) CFU/head of BS 6 times a week for 4 weeks, and DF was applied twice a week for 4 weeks. Histopathological examination revealed significant differences in auricular thickness between Gp DF (664.4 µm, SD=78.0) and Gp DF/BS (278.7 µm, SD = 88.8; p<0.01). The dorsal skin of Gp DF/BS (316.7 µm, SD=187.4) was significantly thinner than that of Gp DF (503 µm, SD=116.3). These results suggest that continuous oral administration of fermented food-derived bacteria (BS) can be effective in alleviating the development of skin lesions induced by DF in NC mice.


Assuntos
Antígenos de Dermatophagoides/imunologia , Bacillus subtilis , Dermatite Alérgica de Contato/imunologia , Probióticos/farmacologia , Administração Oral , Animais , Dermatite Alérgica de Contato/patologia , Dermatite Alérgica de Contato/prevenção & controle , Feminino , Camundongos , Pele/imunologia , Pele/patologia
18.
J Phys Chem B ; 113(42): 13711-4, 2009 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-19572667

RESUMO

Wormlike micelles are assemblies of amphiphilic molecules of intermediate mean curvature between spherical micelles and flat bilayer membranes, which often form in solutions of peptide amphiphiles (hydrophilic peptide modules conjugated to hydrophobic subunits). In an effort to better understand the factors controlling peptide amphiphile (PA) micellar shape, we synthetically linked a short peptide with an alpha-helix-forming tendency to a hexadecyl tail. These molecules initially dissolve as spherical micelles, which can persist for hours or days, followed by transformation to wormlike micelles, which occurs simultaneously with a transition in the secondary structure of the headgroup peptides to beta-sheet. This observation provides evidence that the extended micelle is the thermodynamically favored state sought by PA micelles in the process of forming beta-sheet structures among the head-groups, though they are not the structures formed during the initial kinetics of assembly.


Assuntos
Lipídeos/química , Micelas , Peptídeos/química , Dicroísmo Circular , Estrutura Secundária de Proteína , Termodinâmica
19.
Biochem Biophys Res Commun ; 357(3): 627-32, 2007 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-17445770

RESUMO

Histone tail domains play important roles in cellular processes, such as replication, transcription, and chromosome condensation. Histone H2A has one central and two tail domains, and their functions have mainly been studied from a biochemical perspective. In addition, analyses based on visualization have been employed for functional analysis of some chromatin proteins. In this study, we analyzed histone H2A mobility in vivo by two-photon FRAP, and elucidated that the histone H2A N- and C-terminal tails regulate its mobility. We found that histone H2A mobility was increased following treatment of host cells with a histone deacetylase inhibitor. Our results support a model in which core histone tails directly regulate transcription by interacting with nucleosome DNA via electrostatic interactions.


Assuntos
Recuperação de Fluorescência Após Fotodegradação/métodos , Histonas/metabolismo , Acetilação , Inibidores Enzimáticos/farmacologia , Técnica Indireta de Fluorescência para Anticorpo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HeLa , Inibidores de Histona Desacetilases , Histonas/química , Histonas/genética , Humanos , Ácidos Hidroxâmicos/farmacologia , Immunoblotting , Mutação , Transporte Proteico/efeitos dos fármacos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Tempo , Transfecção
20.
Opt Express ; 15(5): 2490-8, 2007 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-19532486

RESUMO

Spatial and temporal information about intracellular objects and their dynamics within a living cell are essential for dynamic analysis of such objects in cell biology. A specific intracellular object can be discriminated by photoactivatable fluorescent proteins that exhibit pronounced light-induced spectral changes. Here, we report on selective labeling and tracking of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein with near-infrared femtosecond laser pulses. We performed selective labeling of a single mitochondrion in a living tobacco BY-2 cell using two-photon photoconversion of Kaede. Using this technique, we demonstrated that, in plants, the directed movement of individual mitochondria along the cytoskeletons was mediated by actin filaments, whereas microtubules were not required for the movement of mitochondria. This single-organelle labeling technique enabled us to track the dynamics of a single organelle, revealing the mechanisms involved in organelle dynamics. The technique has potential application in direct tracking of selective cellular and intracellular structures.

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