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1.
World J Clin Cases ; 12(8): 1487-1496, 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38576815

RESUMO

BACKGROUND: High-grade pancreatic intraepithelial neoplasia (PanIN) exhibits no mass and is not detected by any examination modalities. However, it can be diagnosed by pancreatic juice cytology from indirect findings. Most previous cases were diagnosed based on findings of a focal stricture of the main pancreatic duct (MPD) and caudal MPD dilatation and subsequent pancreatic juice cytology using endoscopic retrograde cholangiopancreatography (ERCP). We experienced a case of high-grade PanIN with an unclear MPD over a 20-mm range, but without caudal MPD dilatation on magnetic resonance cholangiopancreatography (MRCP). CASE SUMMARY: A 60-year-old female patient underwent computed tomography for a follow-up of uterine cancer post-excision, which revealed pancreatic cysts. MRCP revealed an unclear MPD of the pancreatic body at a 20-mm length without caudal MPD dilatation. Thus, course observation was performed. After 24 mo, MRCP revealed an increased caudal MPD caliber and a larger pancreatic cyst. We performed ERCP and detected atypical cells suspected of adenocarcinoma by serial pancreatic juice aspiration cytology examination. We performed a distal pancreatectomy and obtained a histopathological diagnosis of high-grade PanIN. Pancreatic parenchyma invasion was not observed, and curative resection was achieved. CONCLUSION: High-grade Pan-IN may cause MPD narrowing in a long range without caudal MPD dilatation.

2.
Radiat Res ; 200(5): 503-507, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37801467

RESUMO

Although some adverse effects on neurocognitive function have been reported in children and adolescents irradiated prenatally during the atomic bombings and the Chernobyl nuclear accident, little information is available for effects on the elderly. Here we evaluate the effects of prenatal exposure to atomic bomb radiation on subjective neurocognitive function in aged survivors. To evaluate neurocognitive impairment, we mailed the Neurocognitive Questionnaire (NCQ), a self-administered scale, to prenatally exposed survivors, including clinic visitors and non-visitors at the time of the 2011 and 2013 Adult Health Study (AHS) examinations. We received replies from 444 individuals (mean age, 66.9 ± 0.6 years). After adjusting for sex, city, and educational background, we found no significant effects of radiation, clinic visit, or interaction between radiation and clinic visit on the scores of the 4 NCQ factors of metacognition, emotional regulation, motivation/organization, and processing speed. Even in analyses considering gestational age at the time of the bombings, none of the 4 NCQ factor scores was related to maternal uterine dose. There remains the limitation that this study consisted of healthy survivors, but we found no significant radiation effect on late-life cognition in people prenatally exposed to atomic bomb radiation.


Assuntos
Guerra Nuclear , Armas Nucleares , Lesões por Radiação , Criança , Idoso , Gravidez , Adolescente , Feminino , Humanos , Adulto , Sobreviventes , Fatores de Tempo , Japão
3.
BMC Gastroenterol ; 23(1): 138, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37127562

RESUMO

BACKGROUND: Pathological examination by endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been reported to be useful in diagnosing pancreatic malignant lymphoma (ML), but some ML cases are difficult to be differentiated from pancreatic ductal adenocarcinoma (PDAC). METHODS: This retrospective study included 8 patients diagnosed with ML that had a pancreatic-head lesion at initial diagnosis and 46 patients with resected PDAC in the pancreatic head between April 2006 and October 2021 at our institute. ML and PDAC were compared in terms of patients' clinical features and imaging examinations. RESULTS: The median tumor size was larger in ML than in PDAC (45.8 [24-64] vs. 23.9 [8-44] mm), but the median diameter of the caudal main pancreatic duct (MPD) was larger in PDAC (2.5 [1.0-3.5] vs. 7.1 [2.5-11.8] mm), both showing significant differences between these malignancies (both, P < 0.001). In the analysis of covariance, MLs showed a smaller caudal MPD per tumor size than PDACs, with a statistical difference (P = 0.042). Sensitivity and specificity using sIL-2R ≥ 658 U/mL plus CA19-9 < 37 U/mL for the differentiation of ML from PDAC were 80.0% and 95.6%, respectively. CONCLUSIONS: Diagnosing pancreatic ML using cytohistological examination through EUS-FNA can be difficult in some cases. Thus, ML should be suspected if a patient with a pancreatic tumor has a small MPD diameter per tumor size, high serum sIL-2R level, normal CA19-9 level. If the abovementioned features are present and still cannot be confirmed as PDAC, re-examination should be considered.


Assuntos
Carcinoma Ductal Pancreático , Linfoma , Neoplasias Pancreáticas , Humanos , Estudos Retrospectivos , Antígeno CA-19-9 , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico/métodos , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/patologia , Ductos Pancreáticos/patologia , Neoplasias Pancreáticas
4.
Proc Natl Acad Sci U S A ; 120(15): e2216550120, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-37018193

RESUMO

Spectra and frequencies of spontaneous and X-ray-induced somatic mutations were revealed with mouse long-term hematopoietic stem cells (LT-HSCs) by whole-genome sequencing of clonal cell populations propagated in vitro from single isolated LT-HSCs. SNVs and small indels were the most common types of somatic mutations, and increased up to twofold to threefold by whole-body X-irradiation. Base substitution patterns in the SNVs suggested a role of reactive oxygen species in radiation mutagenesis, and signature analysis of single base substitutions (SBS) revealed a dose-dependent increase of SBS40. Most of spontaneous small deletions were shrinkage of tandem repeats, and X-irradiation specifically induced small deletions out of tandem repeats (non-repeat deletions). Presence of microhomology sequences in non-repeat deletions suggested involvement of microhomology mediated end-joining repair mechanisms as well as nonhomologous end-joining in radiation-induced DNA damages. We also identified multisite mutations and structural variants (SV), i.e., large indels, inversions, reciprocal translocations, and complex variants. The radiation-specificity of each mutation type was evaluated from the spontaneous mutation rate and the per-Gy mutation rate estimated by linear regression, and was highest with non-repeat deletions without microhomology, followed by those with microhomology, SV except retroelement insertions, and multisite mutations; these types were thus revealed as mutational signatures of ionizing radiation. Further analysis of somatic mutations in multiple LT-HSCs indicated that large fractions of postirradiation LT-HSCs originated from single LT-HSCs that survived the irradiation and then expanded in vivo to confer marked clonality to the entire hematopoietic system, with varying clonal expansion and dynamics depending on radiation dose and fractionation.


Assuntos
Células-Tronco Hematopoéticas , Radiação Ionizante , Animais , Camundongos , Mutação , Mutagênese , Raios X , Células-Tronco Hematopoéticas/metabolismo
5.
Medicine (Baltimore) ; 102(12): e33217, 2023 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-36961143

RESUMO

RATIONALE: Recently, the incidence of polyoncosis has been increasing due to advancements in treatment, such as antitumor therapy, which led to a prolonged survival. However, few patients with metastatic pancreatic ductal adenocarcinoma (PDAC) develop second tumors, which render a poor prognosis. We report a rare case of PDAC, which is metachronous with a fatal malignant lymphoma (ML). PATIENT CONCERNS: A 68-year-old woman who had been monitored due to liver cirrhosis secondary to hepatitis C virus infection presented with a 10-mm pancreatic head cancer with lung metastasis and had started an anticancer therapy with gemcitabine. Approximately 18 months after diagnosis, lymphadenopathies around the pancreas were noted, which eventually spread to the entire body over time. DIAGNOSIS: Diffuse large B-cell lymphoma was diagnosed using biopsies from cervical lymph nodes. INTERVENTIONS AND OUTCOMES: The patient started a gemcitabine + rituximab regimen; however, the patient died from cachexia-associated lymphoma progression, not PDAC. LESSONS: ML should be considered when intra-abdominal lymphadenopathies are detected in patients with pancreatic cancer, and ML should be differentiated from lymph node metastasis of pancreatic cancer.


Assuntos
Adenocarcinoma , Carcinoma Ductal Pancreático , Linfadenopatia , Linfoma Difuso de Grandes Células B , Neoplasias Pancreáticas , Feminino , Humanos , Idoso , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/patologia , Adenocarcinoma/patologia , Gencitabina , Linfoma Difuso de Grandes Células B/complicações , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Neoplasias Pancreáticas
6.
JGH Open ; 7(12): 1003-1005, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38162863

RESUMO

A 62-year-old man presented with a 7-cm cystic lesion with irregularly thickened cyst wall in contact with the pancreatic tail. The pancreatic tail was described as hypoechoic on endoscopic ultrasonography. The cyst subsequently increased rapidly to 13 cm, and surgery was performed. This revealed adenosquamous carcinoma in the pancreatic tail to have invaded the stomach and transverse colon along the cyst wall. The cyst was diagnosed as a retention cyst due to pancreatic tail tumor. Invasion of nearby organs by a pancreatic cancer via the retention cyst wall is very rare, but it is necessary to keep the potential for such progress in mind.

7.
Diagnostics (Basel) ; 12(12)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36552920

RESUMO

Recent advancements in surgical and anti-cancer therapies have provided significant hope of long survival in patients with pancreatic cancer (PC). To realize this hope, routine medical checkups of asymptomatic people should be performed to identify operable PCs. In this study, we evaluated the efficacy of medical checkups using abdominal ultrasonography (US). We retrospectively analyzed 374 patients with PC at our institute between 2010 and 2021. We divided these patients into several groups according to the diagnostic approach and compared their background and prognosis. These groups comprised PCs diagnosed through (a) symptoms, 242 cases; (b) US during medical checkup for asymptomatic individuals, 17; and other means. Of the 374 patients, 192 were men (51.3%), and the median age was 74 years (34−105). Tumors were located in the pancreatic tail in 67 patients (17.9%). Excision ratio and 5-year survival rate were significantly better in group (b) than in (a) (58.8% vs. 23.1%, p < 0.01 and 42.2% vs. 9.4%, p < 0.001, respectively). The prognosis of patients diagnosed using US during medical checkup was better than that of patients identified through symptomatic presentation of PC. US for asymptomatic individuals with PC might be one of the useful modalities for promoting better prognosis of PCs.

8.
Radiat Res ; 197(4): 403-407, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35042238

RESUMO

High-dose radiation in childhood such as is used in radiation therapy causes cognitive decline, but there is insufficient research on the cognitive effects of low- to medium-dose radiation. We aimed to reveal the association between atomic bomb radiation exposure in childhood and late-life neurocognitive function. In 2011 and 2013, we mailed the Neurocognitive Questionnaire (NCQ) to subjects who were 12 years old or younger at the time of the atomic bombing. We converted the four NCQ subscales (metacognition, emotional regulation, motivation/organization, and processing speed) to T scores and defined the highest 10% of the controls (exposure dose < 5 mGy) as impaired. We used a generalized linear mixed model to evaluate the effect of radiation exposure on T scores and percentage impaired. We enrolled 859 participants. At the time of the bombing, the mean (SD) age was 6.7 (3.8) years for the control (N = 390) and 6.1 (3.8) years for the exposed (N = 469). At the time of replying to the questionnaire, the mean age of all the participants was 73.7 (3.8) years of age. After adjusting for cofactors, older age was related to the decline of all neurocognitive subscales. Sex and education level had relevance to some of the subscales. For neurocognitive function, exposure dose was not related except to percentage impaired, motivation/organization. Late-life neurocognitive function in atomic bomb survivors exposed as children was associated with age, but not clearly with radiation dose. More studies are needed to evaluate the effect of low-dose radiation during childhood on long-term neurocognitive function.


Assuntos
Armas Nucleares , Exposição à Radiação , Lesões por Radiação , Adulto , Idoso , Sobreviventes de Bombas Atômicas , Criança , Humanos , Japão , Exposição à Radiação/efeitos adversos , Sobreviventes
9.
Free Radic Biol Med ; 171: 126-134, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33992676

RESUMO

Although reactive oxygen species (ROS) play important roles in immune responses, excessive ROS production and accumulation might enhance the risk of inflammation-related diseases. Moreover, impaired immune function and the acceleration of pre-clinically persistent inflammation due to aging and radiation exposure have been observed in atomic bomb (A-bomb) survivors more than 60 years post-exposure. Meanwhile, the effects of aging and radiation exposure on ROS production in immune cells have not been characterized. This study investigated the relationship between intracellular ROS (H2O2 and O2•-) levels in blood cells or T cell subsets and serum iron, ferritin, and C-reactive protein (CRP) levels, as well as how these variables are affected by age and radiation exposure in A-bomb survivors. We examined 2495 Hiroshima A-bomb survivors. Multiple linear regression models adjusted for confounding factors indicated that intracellular O2•- levels in monocytes, granulocytes, and lymphocytes, and particularly in memory CD8+ T cells, including effector memory and terminally differentiated effector memory CD8+ T cells, increased with radiation dose. Additionally, serum iron, ferritin, and CRP levels affected intracellular ROS levels in specific blood cell types and T cell subsets. Serum CRP levels increased significantly with increasing age and radiation dose. Finally, when divided into three groups according to serum CRP levels, dose-dependent increases in the intracellular O2•- levels in blood cells and central memory and effector memory CD8+ T cells were most prominently observed in the high-CRP group. These results suggest that an increase in the levels of certain intracellular ROS, particularly after radiation exposure, might be linked to enhanced inflammatory status, including elevated serum CRP levels and reduced serum iron levels. This study reveals that aging and radiation exposure increase oxidative stress in blood cells, which is involved in impaired immune function and accelerated pre-clinically persistent inflammation in radiation-exposed individuals.


Assuntos
Guerra Nuclear , Exposição à Radiação , Envelhecimento , Sobreviventes de Bombas Atômicas , Linfócitos T CD8-Positivos , Relação Dose-Resposta à Radiação , Humanos , Peróxido de Hidrogênio , Espécies Reativas de Oxigênio , Sobreviventes
10.
Ann Thorac Surg ; 112(3): 839-845, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-32949608

RESUMO

BACKGROUND: Surgery requires a complexity-based ranking system that provides critical information for surgeons to perform strategic operations. However, we still use professional panel systems such as the Risk Adjustment for Congenital Heart Surgery category and the Aristotle Basic Complexity score for this purpose, both of which are subjective. The present study, inspired by more recent development of The Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery mortality scores and categories, applied a Bayesian statistical method to the Japanese nationwide congenital heart registry by estimating inhospital mortality to construct a data-driven, more scientific rating system based on complexity. METHODS: The study used a 5-year dataset from the Japan Cardiovascular Surgery Database congenital section to construct a Bayesian estimation model. There were 25,968 operations with 186 cardiovascular procedures. To validate the model, we used an independent 2-year dataset with 14,904 operations. RESULTS: The model-based inhospital mortality estimation provided a complexity rating system that replicated the past study that had proposed a five-category system based on the estimated mortality scores. The C-index with the validation dataset for the mortality score and category was 0.80 and 0.79, respectively. CONCLUSIONS: The data-driven approach to complexity rating systems for congenital cardiovascular surgery is recommended, as it has better scientific advantages and more convenient updating features.


Assuntos
Cardiopatias Congênitas/mortalidade , Cardiopatias Congênitas/cirurgia , Teorema de Bayes , Procedimentos Cirúrgicos Cardíacos , Mortalidade Hospitalar , Humanos , Japão
11.
Radiat Res ; 195(1): 60-65, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33181839

RESUMO

There is limited evidence concerning the association between radiation exposure and ovarian cancer. We evaluated radiation risk of ovarian cancer between 1958 and 2009 among 62,534 female atomic bomb survivors in the Life Span Study cohort, adding 11 years of follow-up from the previously reported study. Poisson regression methods were used to estimate excess relative risk per Gy (ERR/Gy) for total ovarian cancer and according to tumor type. We assessed the modifying effect of follow-up period and other factors on the radiation risk. We ascertained 288 first primary ovarian cancers including 77 type 1 epithelial cancers, 75 type 2 epithelial cancers, 66 epithelial cancers of undetermined type and 70 other cancers. Radiation dose was positively, although not significantly, associated with risk of total ovarian cancer [ERR/Gy = 0.30, 95% confidence interval (CI): -0.22 to 1.11]. There was a suggestion of heterogeneity in radiation effects (P = 0.08) for type 1 (ERR/Gy = -0.32, 95% CI: <-0.32 to 0.88) and type 2 cancers (ERR/Gy = 1.24, 95% CI: -0.08 to 4.16). There were no significant trends in the ERR with time since exposure or age at exposure. Further follow-up will help characterize more accurately the patterns of radiation risk for total ovarian cancer and its types.


Assuntos
Neoplasias Induzidas por Radiação/epidemiologia , Neoplasias Ovarianas/epidemiologia , Exposição à Radiação/efeitos adversos , Adolescente , Adulto , Sobreviventes de Bombas Atômicas , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Japão/epidemiologia , Longevidade , Pessoa de Meia-Idade , Neoplasias Induzidas por Radiação/patologia , Armas Nucleares , Neoplasias Ovarianas/patologia , Fatores de Risco , Adulto Jovem
12.
J Pediatr Surg ; 55(10): 2064-2070, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32507636

RESUMO

PURPOSE: To establish and validate risk models of mortality and morbidity associated with 12 major pediatric surgical procedures using the National Clinical Database-Pediatric (NCD-P) data. METHODS: We used the NCD-P data for the development and validation datasets. By using multivariate logistic regression to analyze the development dataset, we created a prediction model for 30-day mortality and morbidity in 12 major pediatric surgical procedures, including tracheoplasty, pneumonectomy, fundoplication, total/subtotal excision of malignant tumor, and surgeries for Hirschsprung disease, anorectal malformation, biliary atresia, choledocal cyst, midgut volvulus, funnel chest, gastrointestinal perforation, and intestinal obstruction. We selected variables that were almost identical to those used in the American College of Surgeons National Surgical Quality Improvement Program-Pediatric (NSQIP-P). The primary outcomes were 30-day mortality and composite morbidity. We assessed the obtained models using the C-indices of the development and validation datasets. RESULTS: Overall, 10 and 21 variables were identified for mortality and morbidity, respectively. C-indices of mortality were 0.940 and 0.924 in the development and validation datasets, respectively. C-indices of morbidity were 0.832 and 0.830 in the development and validation datasets, respectively. CONCLUSIONS: Based on the NCD-P data, we developed satisfactory risk models for mortality and morbidity prediction in major pediatric surgeries. LEVEL OF EVIDENCE: Level I (Prognosis Study).


Assuntos
Complicações Pós-Operatórias/epidemiologia , Procedimentos Cirúrgicos Operatórios , Criança , Bases de Dados Factuais , Humanos , Japão , Morbidade , Melhoria de Qualidade , Medição de Risco , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Procedimentos Cirúrgicos Operatórios/mortalidade
13.
PLoS One ; 13(12): e0208415, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30533017

RESUMO

Duchenne muscular dystrophy (DMD) is an X-linked muscle disorder characterized by primary muscle degeneration. Patients with DMD reveal progressive muscle weakness leading to ambulatory dysfunction. Novel outcome measures are needed for more sensitive evaluation of therapeutic effects in clinical trials. Multiple parameters of acceleration and angular velocity are used as efficient indicators to quantify the motion of subjects, and these parameters have been recently applied for evaluation of motor function in DMD. In the present study, we evaluated gait in a dystrophic dog model, CXMDJ, by measuring three-axial acceleration and angular velocity over the course of months. Hybrid sensors were placed on the dorsal thoracic and lumbar regions of dogs to detect a wide range of acceleration (±8 G) and angular velocity (±1000 degrees per second). Multiple parameters showed lower values in dystrophic dogs compared to wild-type (WT) dogs, and declined over the course of months. Acceleration magnitude (AM) at the thoracic region in dystrophic dogs was prominently lower compared with WT dogs, even at the age of 2 months, the onset of muscle weakness, whereas AM at the lumbar region drastically declined throughout the disease course. The angular velocity index in the vertical direction in the lumbar region increased in dystrophic dogs, suggesting waddling at the girdle. These parameters also accordingly decreased with exacerbation of clinical manifestations and a decrease in spontaneous locomotor activity. The AM of dystrophic dogs was analyzed with magnetic resonance imaging to look for a correlation with crus muscle involvement. Results showed that acceleration and angular velocity are multifaceted kinematic indices that can be applied to assess outcomes in clinical trials for hereditary neuromuscular disorders including DMD.


Assuntos
Acelerometria , Doenças do Cão , Músculo Esquelético , Distrofia Muscular Animal , Animais , Cães , Feminino , Masculino , Acelerometria/métodos , Acelerometria/veterinária , Modelos Animais de Doenças , Doenças do Cão/diagnóstico , Doenças do Cão/fisiopatologia , Marcha/fisiologia , Imageamento por Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/veterinária , Atividade Motora/fisiologia , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/fisiopatologia , Distrofia Muscular Animal/diagnóstico , Distrofia Muscular Animal/fisiopatologia , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/patologia , Distrofia Muscular de Duchenne/fisiopatologia , Valor Preditivo dos Testes , Prognóstico
14.
Plant Physiol ; 171(2): 1470-84, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27208244

RESUMO

Plant perception of pathogen-associated molecular patterns (PAMPs) and other environmental stresses trigger transient ion fluxes at the plasma membrane. Apart from the role of Ca(2+) uptake in signaling, the regulation and significance of PAMP-induced ion fluxes in immunity remain unknown. We characterized the functions of INTEGRIN-LINKED KINASE1 (ILK1) that encodes a Raf-like MAP2K kinase with functions insufficiently understood in plants. Analysis of ILK1 mutants impaired in the expression or kinase activity revealed that ILK1 contributes to plant defense to bacterial pathogens, osmotic stress sensitivity, and cellular responses and total ion accumulation in the plant upon treatment with a bacterial-derived PAMP, flg22. The calmodulin-like protein CML9, a negative modulator of flg22-triggered immunity, interacted with, and suppressed ILK1 kinase activity. ILK1 interacted with and promoted the accumulation of HAK5, a putative (H(+))/K(+) symporter that mediates a high-affinity uptake during K(+) deficiency. ILK1 or HAK5 expression was required for several flg22 responses including gene induction, growth arrest, and plasma membrane depolarization. Furthermore, flg22 treatment induced a rapid K(+) efflux at both the plant and cellular levels in wild type, while mutants with impaired ILK1 or HAK5 expression exhibited a comparatively increased K(+) loss. Taken together, our results position ILK1 as a link between plant defense pathways and K(+) homeostasis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/imunologia , Arabidopsis/fisiologia , Imunidade Inata , Imunidade Vegetal , Antiportadores de Potássio-Hidrogênio/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Estresse Fisiológico , Sequência de Aminoácidos , Arabidopsis/genética , Arabidopsis/microbiologia , Calmodulina/metabolismo , Flagelina/farmacologia , Homeostase/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Íons , Manitol/farmacologia , Modelos Biológicos , Mutação/genética , Osmose/efeitos dos fármacos , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Imunidade Vegetal/efeitos dos fármacos , Plantas Geneticamente Modificadas , Potássio/metabolismo , Ligação Proteica/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/química , Transporte Proteico/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Nicotiana/genética
15.
PLoS One ; 11(2): e0148256, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26886551

RESUMO

The firefly luciferase complementation assay is widely used as a bioluminescent reporter technology to detect protein-protein interactions in vitro, in cellulo, and in vivo. Upon the interaction of a protein pair, complemented firefly luciferase emits light through the adenylation and oxidation of its substrate, luciferin. Although it has been suggested that kinetics of light production in the firefly luciferase complementation assay is different from that in full length luciferase, the mechanism behind this is still not understood. To quantitatively understand the different kinetics and how changes in affinity of a protein pair affect the light emission in the assay, a mathematical model of the in vitro firefly luciferase complementation assay was constructed. Analysis of the model finds that the change in kinetics is caused by rapid dissociation of the protein pair, low adenylation rate of luciferin, and increased affinity of adenylated luciferin to the enzyme. The model suggests that the affinity of the protein pair has an exponential relationship with the light detected in the assay. This relationship causes the change of affinity in a protein pair to be underestimated. This study underlines the importance of understanding the molecular mechanism of the firefly luciferase complementation assay in order to analyze protein pair affinities quantitatively.


Assuntos
Bioensaio/métodos , Luciferases de Vaga-Lume/metabolismo , Luminescência , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Monofosfato de Adenosina/metabolismo , Simulação por Computador , Concentração Inibidora 50 , Cinética , Luciferases de Vaga-Lume/química , Modelos Teóricos , Estrutura Terciária de Proteína , Reprodutibilidade dos Testes
16.
Plant J ; 56(3): 457-69, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18643993

RESUMO

We used the chimeric Arabidopsis cyclic nucleotide-gated ion channel AtCNGC11/12 to conduct a structure-function study of plant cyclic nucleotide-gated ion channels (CNGCs). AtCNGC11/12 induces multiple pathogen resistance responses in the Arabidopsis mutant constitutive expresser of PR genes 22 (cpr22). A genetic screen for mutants that suppress cpr22-conferred phenotypes identified an intragenic mutant, #73, which has a glutamate to lysine substitution (E519K) at the beginning of the eighth beta-sheet of the cyclic nucleotide-binding domain in AtCNGC11/12. The #73 mutant is morphologically identical to wild-type plants and has lost cpr22-related phenotypes including spontaneous cell death and enhanced pathogen resistance. Heterologous expression analysis using a K(+)-uptake-deficient yeast mutant revealed that this Glu519 is important for AtCNGC11/12 channel function, proving that the occurrence of cpr22 phenotypes requires active channel function of AtCNGC11/12. Additionally, Glu519 was also found to be important for the function of the wild-type channel AtCNGC12. Computational structural modeling and in vitro cAMP-binding assays suggest that Glu519 is a key residue for the structural stability of AtCNGCs and contributes to the interaction of the cyclic nucleotide-binding domain and the C-linker domain, rather than the binding of cAMP. Furthermore, a mutation in the alpha-subunit of the human cone receptor CNGA3 that causes total color blindness aligned well to the position of Glu519 in AtCNGC11/12. This suggests that AtCNGC11/12 suppressors could be a useful tool for discovering important residues not only for plant CNGCs but also for CNGCs in general.


Assuntos
Aminoácidos/química , Proteínas de Arabidopsis/química , Arabidopsis/genética , Canais de Cátion Regulados por Nucleotídeos Cíclicos/química , Sequência de Aminoácidos , Aminoácidos/genética , Arabidopsis/química , Proteínas de Arabidopsis/genética , Cruzamentos Genéticos , Canais de Cátion Regulados por Nucleotídeos Cíclicos/genética , Genes de Plantas , Humanos , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese , Proteínas Mutantes Quiméricas/química , Proteínas Mutantes Quiméricas/genética , Mutação , Fenótipo , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Plasmídeos , Estrutura Secundária de Proteína , RNA de Plantas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/genética , Alinhamento de Sequência , Relação Estrutura-Atividade , Nicotiana/química , Nicotiana/genética
17.
Dev Cell ; 4(1): 53-66, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12530963

RESUMO

AGAMOUS, a key player in floral morphogenesis, specifies reproductive organ identities and regulates the timely termination of stem cell fates in the floral meristem. Here, we report that strains carrying mutations in three genes, HUA1, HUA2, and HUA ENHANCER4 (HEN4), exhibit floral defects similar to those in agamous mutants: reproductive-to-perianth organ transformation and loss of floral determinacy. HEN4 codes for a K homology (KH) domain-containing, putative RNA binding protein that interacts with HUA1, a CCCH zinc finger RNA binding protein in the nucleus. We show that HUA1 binds AGAMOUS pre-mRNA in vitro and that HEN4, HUA1, and HUA2 act in floral morphogenesis by specifically promoting the processing of AGAMOUS pre-mRNA. Our studies underscore the importance of RNA processing in modulating plant development.


Assuntos
Proteína AGAMOUS de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Ligação a DNA/metabolismo , RNA Helicases/metabolismo , Precursores de RNA/metabolismo , Processamento Pós-Transcricional do RNA , Proteínas de Ligação a RNA/metabolismo , Sequência de Aminoácidos , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Clonagem Molecular , Proteínas de Ligação a DNA/genética , Flores/genética , Flores/crescimento & desenvolvimento , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Dados de Sequência Molecular , Morfogênese , Mutação/genética , Estrutura Terciária de Proteína , RNA Helicases/química , RNA Helicases/genética , Precursores de RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Nicotiana , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Dedos de Zinco
18.
Plant Physiol ; 129(3): 931-42, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12114548

RESUMO

The control of subcellular localization of proteins and their interaction with other partners in vivo are important parameters that provide clues to their function and regulation. The ability to simultaneously track multiple protein species with high resolution should provide a valuable assay system to study and characterize various types of posttranslational control pathways. In this work, we established the system and a method involving "spectral profiling" for the resolution of four different fluorescent protein tags in the same viewing field using digital imaging technology. With these techniques, we have (a) developed new derivatives of mGFP5, which is commonly used in the plant field, that are about three times brighter; (b) demonstrated that four spectrally distinct fluorescent proteins (cyan, green, yellow, and red) that are fused to a transcription factor could be stably expressed in nuclei and distinguished in tobacco (Nicotiana tabacum) mesophyll cells; and (c) shown that interaction between partners of a dimeric transcription factor can be detected by measuring fluorescence resonance energy transfer. These technologies should help one to study protein-protein interactions efficiently, especially for nuclear proteins under in vivo conditions.


Assuntos
Núcleo Celular/metabolismo , Proteínas Luminescentes/metabolismo , Nicotiana/genética , Espectrometria de Fluorescência/métodos , Fatores de Transcrição/metabolismo , Clonagem Molecular , Proteínas Luminescentes/genética , Microscopia de Fluorescência , Mutação , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas , Mapeamento de Interação de Proteínas/métodos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Nicotiana/metabolismo , Fatores de Transcrição/genética
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