Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 168
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Epilepsy Behav ; 152: 109659, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38301454

RESUMO

Depression is prevalent in epilepsy patients and their intracranial brain activity recordings can be used to determine the types of brain activity that are associated with comorbid depression. We performed case-control comparison of spectral power and phase amplitude coupling (PAC) in 34 invasively monitored drug resistant epilepsy patients' brain recordings. The values of spectral power and PAC for one-minute segments out of every hour in a patient's study were correlated with pre-operative assessment of depressive symptoms by Beck Depression Inventory-II (BDI). We identified an elevated PAC signal (theta-alpha-beta phase (5-25 Hz)/gamma frequency (80-100 Hz) band) that is present in high BDI scores but not low BDI scores adult epilepsy patients in brain regions implicated in primary depression, including anterior cingulate cortex, amygdala and orbitofrontal cortex. Our results showed the application of PAC as a network-specific, electrophysiologic biomarker candidate for comorbid depression and its potential as treatment target for neuromodulation.


Assuntos
Ondas Encefálicas , Epilepsia , Adulto , Humanos , Depressão/diagnóstico , Depressão/etiologia , Epilepsia/complicações , Epilepsia/diagnóstico , Encéfalo , Ondas Encefálicas/fisiologia , Córtex Pré-Frontal , Eletroencefalografia
2.
PLoS Genet ; 17(2): e1009346, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33524034

RESUMO

Ethanol is a widely used drug, excessive consumption of which could lead to medical conditions with diverse symptoms. Ethanol abuse causes dysfunction of memory, attention, speech and locomotion across species. Dopamine signaling plays an essential role in ethanol dependent behaviors in animals ranging from C. elegans to humans. We devised an ethanol dependent assay in which mutants in the dopamine autoreceptor, dop-2, displayed a unique sedative locomotory behavior causing the animals to move in circles while dragging the posterior half of their body. Here, we identify the posterior dopaminergic sensory neuron as being essential to modulate this behavior. We further demonstrate that in dop-2 mutants, ethanol exposure increases dopamine secretion and functions in a DVA interneuron dependent manner. DVA releases the neuropeptide NLP-12 that is known to function through cholinergic motor neurons and affect movement. Thus, DOP-2 modulates dopamine levels at the synapse and regulates alcohol induced movement through NLP-12.


Assuntos
Caenorhabditis elegans/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , Etanol/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/fisiologia , Depressores do Sistema Nervoso Central/farmacologia , Dopamina/metabolismo , Neurônios Dopaminérgicos/fisiologia , Humanos , Locomoção/efeitos dos fármacos , Neurônios Motores/efeitos dos fármacos , Neurônios Motores/fisiologia , Mutação , Neuropeptídeos/metabolismo , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/fisiologia , Transdução de Sinais/efeitos dos fármacos
3.
J Labelled Comp Radiopharm ; 67(1): 18-24, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38044291

RESUMO

Nitrofurazone usage in food-producing animals is prohibited in most countries, including the United States. Regulatory agencies regularly monitor its use in domestic, export/import animals' food products by measuring the semicarbazide (SEM) metabolite as a biomarker of nitrofurazone exposure. However, the use of SEM is controversial because it is also produced in food naturally and thus gives false positive results. A cyano-metabolite, 4-cyano-2-oxobutyraldehyde semicarbazone (COBS), is proposed as an alternate specific marker of nitrofurazone to distinguish nitrofurazone from treated or untreated animals. A synthetic method was developed to produce COBS via metallic hydrogenation of nitrofurazone. The product was isolated and characterized by one- and two-dimensional nuclear magnetic spectroscopy (NMR) experiments, Fourier-transform infrared spectroscopy (FT-IR), and mass spectrometry. The developed synthetic procedure was further extended to synthesize isotopically labeled 4-[13 C]-cyano-2-oxo- [2, 3, 4-13 C3 ]-butyraldehyde semicarbazone. Labeled COBS is useful as an internal standard for its quantification in food-producing animals. Thus, the developed method provides a possibility for its commercial synthesis to procure COBS. This is the first synthesis of the alternate specific marker metabolite of nitrofurazone for possible usage in regulatory analysis to solve a real-world problem.


Assuntos
Nitrofurazona , Semicarbazonas , Animais , Nitrofurazona/análise , Nitrofurazona/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Semicarbazidas/análise , Semicarbazidas/química , Semicarbazidas/metabolismo
4.
Homeopathy ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714214

RESUMO

BACKGROUND: Prior vaccination is often studied for its impact on individuals' post-infection prognosis. Ayurveda, Yoga, Unani, Siddha and Homeopathy (AYUSH) medicines, advised by the Government of India as prophylaxis during the first wave of the coronavirus disease 2019 (COVID-19) pandemic, were consumed by the masses in 2020. A study was therefore undertaken to observe any association between the prior usage of AYUSH prophylactic medicines and post-infection severity as reported by recovered COVID-19 individuals. METHODS: This was a retrospective, multi-centre, cohort study conducted in 21 cities of India from 5th August to 30th November 2020. Data from recovered COVID-19 patients, of either sex or any age, captured information about AYUSH prophylactic medicines intake prior to infection, disease severity, symptomatology, duration of complaints, etc. The study participants were grouped into AYUSH intake and non-intake. Primary composite outcome was the disease clinical course. Secondary clinical outcomes were the rate of and time to clinical recovery. RESULTS: Data of 5,023 persons were analysed. Ayurveda or homeopathic prophylactic medicines were consumed by more than half of the study participants: that is, 56.85% (n = 1,556) and 56.81% (n = 1,555) respectively. The overall adjusted protective effect (PE) of AYUSH prophylactic intake against moderate/severe forms of COVID-19 disease was 56.7% (95% confidence interval [CI], 48.7 to 63.50; p < 0.001). Adjusted PE for homeopathy and Siddha was 52.9% (95% CI, 42.30 to 61.50; p < 0.001) and 59.8% (95% CI, 37.80 to 74.10; p < 0.001), respectively. A statistically significant association was found between AYUSH prophylactic medicine intake and clinical recovery more frequently by the 3rd day of illness (χ2 = 9.01; p = 0.002). Time to resolution of symptoms in the AYUSH intake group was on average 0.3 days earlier than in the non-intake group (p = 0.002). CONCLUSION: AYUSH prophylactics were associated with statistically significant levels of protection against COVID-19 disease severity. Amongst these, previous intake of homeopathy or Siddha medicines was associated with some protection against moderate/severe illness and with a somewhat quicker clinical recovery. Prospective studies with experimental research design are needed to validate the findings of this study. STUDY REGISTRATION: Clinical Trials Registry-India (CTRI/2020/08/027000).

5.
Epilepsia ; 64(10): 2725-2737, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37452760

RESUMO

OBJECTIVES: Coronavirus disease 2019 (COVID-19) is associated with mortality in persons with comorbidities. The aim of this study was to evaluate in-hospital outcomes in patients with COVID-19 with and without epilepsy. METHODS: We conducted a retrospective study of patients with COVID-19 admitted to a multicenter health system between March 15, 2020, and May 17, 2021. Patients with epilepsy were identified using a validated International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)/ICD-10-CM case definition. Logistic regression models and Kaplan-Meier analyses were conducted for mortality and non-routine discharges (i.e., not discharged home). An ordinary least-squares regression model was fitted for length of stay (LOS). RESULTS: We identified 9833 people with COVID-19 including 334 with epilepsy. On univariate analysis, people with epilepsy had significantly higher ventilator use (37.70% vs 14.30%, p < .001), intensive care unit (ICU) admissions (39.20% vs 17.70%, p < .001) mortality rate (29.60% vs 19.90%, p < .001), and longer LOS (12 days vs 7 days, p < .001). and fewer were discharged home (29.64% vs 57.37%, p < .001). On multivariate analysis, only non-routine discharge (adjusted odds ratio [aOR] 2.70, 95% confidence interval [CI] 2.00-3.70; p < .001) and LOS (32.50% longer, 95% CI 22.20%-43.60%; p < .001) were significantly different. Factors associated with higher odds of mortality in epilepsy were older age (aOR 1.05, 95% CI 1.03-1.08; p < .001), ventilator support (aOR 7.18, 95% CI 3.12-16.48; p < .001), and higher Charlson comorbidity index (CCI) (aOR 1.18, 95% CI 1.04-1.34; p = .010). In epilepsy, admissions between August and December 2020 or January and May 2021 were associated with a lower odds of non-routine discharge and decreased LOS compared to admissions between March and July 2020, but this difference was not statistically significant. SIGNIFICANCE: People with COVID-19 who had epilepsy had a higher odds of non-routine discharge and longer LOS but not higher mortality. Older age (≥65), ventilator use, and higher CCI were associated with COVID-19 mortality in epilepsy. This suggests that older adults with epilepsy and multimorbidity are more vulnerable than those without and should be monitored closely in the setting of COVID-19.


Assuntos
COVID-19 , Epilepsia , Humanos , Idoso , Estudos de Coortes , Estudos Retrospectivos , Tempo de Internação , Epilepsia/epidemiologia , Hospitais , Mortalidade Hospitalar
6.
J Pediatr Hematol Oncol ; 45(4): e530-e533, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36716052

RESUMO

Differentiating hepatoblastomas from other congenital benign hepatic tumors is key to surgical management. We, herein, present an unusual case of an antenatally diagnosed liver lesion assessed in the neonatal period. Because of its predominantly cystic ultrasound/MRI appearance and borderline alpha-fetoprotein serum levels the diagnosis of mesenchymal hamartoma was favored and protocol-based tumor resection was performed. Due to the intraoperative diagnosis of a fetal subtype of hepatoblastoma with positive resection margins the child had to undergo a second laparotomy. This report raises awareness to an unusual appearance of hepatoblastoma and discusses noninvasive imaging clues to consider atypical appearances of hepatoblastoma preoperatively as they can have profound implications in patient management.


Assuntos
Hamartoma , Hepatoblastoma , Neoplasias Hepáticas , Recém-Nascido , Criança , Humanos , Hepatoblastoma/diagnóstico , Hepatoblastoma/patologia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/cirurgia , Imageamento por Ressonância Magnética , Hamartoma/diagnóstico por imagem , Hamartoma/cirurgia
7.
Environ Res ; 218: 114853, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36403649

RESUMO

Hexabromocyclododecane (HBCD) is a brominated flame retardant (BFR) labeled by the Stockholm Convention as a persistent organic pollutant (POP) and exists primarily as three stereoisomers, i.e. α-, ß-, and γ. One of the major routes of human exposure to HBCD is dust found in homes, offices, and cars and dust may be the most important route of HBCD exposure in young children. A study was conducted to determine the oral bioavailability of HBCD from household dust in rats over a 21-d feeding period relative to HBCD bioavailability from a corn oil matrix. Twenty-four hours after the last exposure, rats were sacrificed, and various tissues were collected. HBCD diastereomers were detected in adipose, blood, and liver of both dose groups, suggesting HBCD is bioavailable from both oil and dust. ß-HBCD concentrations were below the limit of detection in all tissues, but α-HBCD was detected in the brain of oil-dose rats and in adipose and liver of both dose groups. γ-HBCD was the dominant diastereomer in adipose, blood, and liver samples regardless of dosing matrix. Except for γ-HBCD in muscle of the oil-dosed group, muscle did not contain measurable HBCDs. Adipose tissue accumulated HBCD to a greater extent than muscle or liver, having bioaccumulation factors greater than 1.


Assuntos
Retardadores de Chama , Hidrocarbonetos Bromados , Criança , Ratos , Humanos , Animais , Pré-Escolar , Poeira , Disponibilidade Biológica
8.
J Labelled Comp Radiopharm ; 66(14): 467-472, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37941144

RESUMO

The veterinary drug nitrofurazone (5-nitro-2-furaldehyde semicarbazone) exhibits excellent antimicrobial properties but its application in food-producing animals is prohibited. The illegal use of nitrofurazone is regularly monitored by food regulatory agencies. Currently, semicarbazide (SEM) is used as a marker of nitrofurazone exposure. However, the use of SEM as a marker of nitrofurazone is under scrutiny after evidence of a high incidence of false positive tests. To overcome the current dilemma, it is necessary to identify a nitrofurazone-specific marker analyte which requires conducting nitrofurazone metabolism studies in food-producing animals. The use of carbon-14 labeled nitrofurazone would facilitate metabolism studies and structural elucidation of nitrofurazone metabolites of possible utility as a marker compound. In the present work, a synthetic method is described to procure radiolabeled nitrofurazone that incorporates 14 C- carbon at the semicarbazide moiety. The method incorporates 14 C-carbon via employing readily available and more economically affordable [14 C]-urea compared with [14 C]-semicarbazide. To the best of our knowledge, there is no report on the synthesis of 5-nitro-2-furaldehyde [14 C]-semicarbazone from 14 C-urea. The developed method involves monoamination of [14 C]-urea followed by a condensation reaction with 5-nitro-2-furaldehyde to produce 5-nitro-2-furaldehyde [14 C]-semicarbazone in 85% yield with greater than 98% radiochemical purity.


Assuntos
Nitrofurazona , Semicarbazonas , Animais , Ureia/química , Radioisótopos de Carbono
9.
J Urol ; 208(6): 1314-1322, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36215077

RESUMO

PURPOSE: Vesicoureteral reflux grading from voiding cystourethrograms is highly subjective with low reliability. We aimed to demonstrate improved reliability for vesicoureteral reflux grading with simple and machine learning approaches using ureteral tortuosity and dilatation on voiding cystourethrograms. MATERIALS AND METHODS: Voiding cystourethrograms were collected from our institution for training and 5 external data sets for validation. Each voiding cystourethrogram was graded by 5-7 raters to determine a consensus vesicoureteral reflux grade label and inter- and intra-rater reliability was assessed. Each voiding cystourethrogram was assessed for 4 features: ureteral tortuosity, proximal, distal, and maximum ureteral dilatation. The labels were then assigned to the combination of the 4 features. A machine learning-based model, qVUR, was trained to predict vesicoureteral reflux grade from these features and model performance was assessed by AUROC (area under the receiver-operator-characteristic). RESULTS: A total of 1,492 kidneys and ureters were collected from voiding cystourethrograms resulting in a total of 8,230 independent gradings. The internal inter-rater reliability for vesicoureteral reflux grading was 0.44 with a median percent agreement of 0.71 and low intra-rater reliability. Higher values for each feature were associated with higher vesicoureteral reflux grade. qVUR performed with an accuracy of 0.62 (AUROC=0.84) with stable performance across all external data sets. The model improved vesicoureteral reflux grade reliability by 3.6-fold compared to traditional grading (P < .001). CONCLUSIONS: In a large pediatric population from multiple institutions, we show that machine learning-based assessment for vesicoureteral reflux improves reliability compared to current grading methods. qVUR is generalizable and robust with similar accuracy to clinicians but the added prognostic value of quantitative measures warrants further study.


Assuntos
Ureter , Refluxo Vesicoureteral , Criança , Humanos , Refluxo Vesicoureteral/diagnóstico por imagem , Reprodutibilidade dos Testes , Cistografia/métodos , Aprendizado de Máquina , Estudos Retrospectivos
10.
J Magn Reson Imaging ; 55(6): 1696-1707, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35312203

RESUMO

BACKGROUND: Evaluation of structural lung abnormalities with magnetic resonance imaging (MRI) has previously been shown to be predictive of clinical neonatal outcomes in preterm birth. MRI during free-breathing with phase-resolved functional lung (PREFUL) may allow for complimentary functional information without exogenous contrast. PURPOSE: To investigate the feasibility of structural and functional pulmonary MRI in a cohort of neonates and infants with no cardiorespiratory disease. Macrovascular pulmonary blood flows were also evaluated. STUDY TYPE: Prospective. POPULATION: Ten term infants with no clinically defined cardiorespiratory disease were imaged. Infants recruited from the general population and neonatal intensive care unit (NICU) were studied. FIELD STRENGTH/SEQUENCE: T1 -weighted VIBE, T2 -weighted BLADE uncorrected for motion. Ultrashort echo time (UTE) and 3D-flow data were acquired during free-breathing with self-navigation and retrospective reconstruction. Single slice 2D-gradient echo (GRE) images were acquired during free-breathing for PREFUL analysis. Imaging was performed at 3 T. ASSESSMENT: T1 , T2 , and UTE images were scored according to the modified Ochiai scheme by three pediatric body radiologists. Ventilation/perfusion-weighted maps were extracted from free-breathing GRE images using PREFUL analysis. Ventilation and perfusion defect percent (VDP, QDP) were calculated from the segmented ventilation and perfusion-weighted maps. Time-averaged cardiac blood velocities from three-dimensional-flow were evaluated in major pulmonary arteries and veins. STATISTICAL TEST: Intraclass correlation coefficient (ICC). RESULTS: The ICC of replicate structural scores was 0.81 (95% CI: 0.45-0.95) across three observers. Elevated Ochiai scores, VDP, and QDP were observed in two NICU participants. Excluding these participants, mean ± standard deviation structural scores were 1.2 ± 0.8, while VDP and QDP were 1.0% ± 1.1% and 0.4% ± 0.5%, respectively. Main pulmonary arterial blood flows normalized to body surface area were 3.15 ± 0.78 L/min/m2 . DATA CONCLUSION: Structural and functional pulmonary imaging is feasible using standard clinical MRI hardware (commercial whole-body 3 T scanner, table spine array, and flexible thoracic array) in free-breathing infants. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1.


Assuntos
Nascimento Prematuro , Criança , Estudos de Viabilidade , Feminino , Humanos , Imageamento Tridimensional , Recém-Nascido , Pulmão , Imageamento por Ressonância Magnética , Gravidez , Estudos Prospectivos , Estudos Retrospectivos
11.
Environ Res ; 209: 112844, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35101398

RESUMO

Potentially toxic elements (PTEs) such as toxic metal (loid)s and other emerging hazardous contaminants, exist in the environment and poses a serious threat. A large amount of wastewater containing PTEs such as cadmium, chromium, copper, nickel, arsenic, lead, zinc, etc. Release from industries during production process. Besides these, chemical-based fertilizers used in soils during crop production have become one of the crucial sources of PTEs. Various techniques are being employed for the mitigation of PTEs like chemical precipitation, ion exchange, coagulation, activated carbon, adsorption, membrane filtration, and bioremediation. Among these mitigation strategies, biological processes such as bioremediation, phytoremediation etc. Are extensively used, as they are economic have high-efficiency rate and are eco-friendly. This review intends to provide information on PTEs contamination through various sources; along with the toxicity of metal (loid)s with respect to their patterns of transmission and risks in the changing environment. Various remediation methods for the management of these pollutants along with their techno-economic perspective are also summarized in this review.


Assuntos
Metais Pesados , Poluentes do Solo , Biodegradação Ambiental , Cádmio/análise , Cádmio/toxicidade , Poluentes Ambientais/toxicidade , Poluição Ambiental/efeitos adversos , Metais/toxicidade , Metais Pesados/análise , Metais Pesados/toxicidade , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Águas Residuárias/toxicidade
12.
Dig Dis Sci ; 67(4): 1187-1199, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33877497

RESUMO

Intestinal lymphoma, although rare, is the second most common extra-nodal site of lymphoma, following stomach. It is usually secondary to systemic involvement and is predominantly of non-Hodgkin's subtype. In addition to the risk factors for lymphomas occurring elsewhere, certain risk factors are specific for intestinal lymphoma. These include enteropathies such as celiac disease and inflammatory bowel disease. Imaging is the cornerstone in the management of intestinal lymphoma. Contrast-enhanced computed tomography or positron emission tomography-computed tomography are the preferred modalities for diagnosis, staging, monitoring response to treatment, and for follow-up evaluation. Bowel lymphomas can have various morphological patterns on imaging; however, certain characteristic features, if present, may prove invaluable in its diagnosis. Hence, it is imperative to be acquainted with the myriad of imaging findings in bowel lymphoma and its complications which may not only help in vivo distinction from other commoner bowel lesions but alter the management accordingly.


Assuntos
Doença Celíaca , Neoplasias Intestinais , Linfoma , Humanos , Neoplasias Intestinais/diagnóstico por imagem , Linfoma/diagnóstico por imagem , Linfoma/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia Computadorizada por Raios X
13.
J Anaesthesiol Clin Pharmacol ; 38(2): 184-190, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36171917

RESUMO

Background and Aims: Several supraglottic airway devices (SGD) are available nowadays. But none has been found to be better than Proseal laryngeal mask (PLMA) in terms of oropharyngeal leak pressure (OLP). We aimed to compare OLP of newly introduced Baska® Mask with PLMA in patients undergoing elective surgical procedures under general anesthesia. Material and Methods: Totally, 80 consecutive adult patients of either sex requiring general anesthesia were randomized into two groups Group B (Baska mask, n = 40) or Group P (PLMA. n = 40). After standardized induction with propofol 2 - 2.5 mg/kg-1 and fentanyl 2 mgkg-1, and muscle relaxation with vecuronium 0.1 mgkg-1 one of the two devices was placed. OLP (primary outcome) was measured 5 minutes and 30 minutes post induction. The time needed to achieve effective airway, anatomical alignment of the device, number of attempts, leak fraction, and postoperative laryngopharyngeal morbidity were noted. Results: Both the devices could be inserted in first attempt in all the patients, but the time needed to achieve effective airway was significantly less in Group B (12.58 ± 1.81 sec vs 17.92 ± 2.45 sec, P < 0.001). The mean OLP was better in Group B at 5 min (37.6 ± 2.43 cm H2O vs 30.82 ± 3.96 cm H2O) and at 30 min (38.83 ± 1.72 cm H2O vs 30.82 ± 3.96 cm H2O; P < 0.001). Anatomical alignment of SGD with glottis (FOB grade 3 or 4 view) was significantly better in group B (34/40) as compared to group P (25/40) (p = 0.009). There was no difference in laryngopharyngeal morbidity in the two groups. Conclusion: Baska mask provided higher OLP, better alignment to the glottis and faster placement time as compared to PLMA.

14.
J Exp Bot ; 72(20): 7119-7135, 2021 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-34185840

RESUMO

The importance of increasing photosynthetic efficiency for sustainable crop yield increases to feed the growing world population is well recognized. The natural genetic variation in leaf photosynthesis in crop plants is largely unexploited for increasing yield potential. The genus Oryza, including cultivated rice and wild relatives, offers tremendous genetic variability to explore photosynthetic differences and underlying biochemical, photochemical, and developmental traits. We quantified leaf photosynthesis and related physiological parameters for six cultivated and three wild rice genotypes, and identified photosynthetically efficient wild rice accessions. Fitting A/Ci curves and biochemical analyses showed that leaf photosynthesis in cultivated rice varieties IR 64 and Nipponbare was limited due to leaf nitrogen content, Rubisco activity, and electron transport rate compared with photosynthetically efficient wild rice accessions Oryza australiensis and Oryza latifolia. The selected wild rice accessions with high leaf photosynthesis per unit area had anatomical features such as larger mesophyll cells with more chloroplasts, fewer mesophyll cells between two adjacent veins, and higher mesophyll cell and chloroplast surface area exposed to intercellular space. Our results show the existence of desirable variations in Rubisco activity, electron transport rate, and leaf anatomical features that could be targeted for increasing the photosynthetic efficiency of cultivated rice varieties.


Assuntos
Oryza , Ribulose-Bifosfato Carboxilase , Transporte de Elétrons , Células do Mesofilo , Oryza/genética , Fotossíntese , Folhas de Planta
15.
J Exp Bot ; 72(12): 4355-4372, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-33587747

RESUMO

Source-sink relationships are key to overall crop performance. Detailed understanding of the factors that determine source-sink dynamics is imperative for the balance of biomass and grain yield in crop plants. We investigated the differences in source-sink relationships between a cultivated rice, Oryza sativa cv. Nipponbare, and a wild rice, Oryza australiensis, which show striking differences in biomass and grain yield. Oryza australiensis, which accumulates a higher biomass, not only showed higher photosynthesis per unit leaf area but also exported more sucrose from leaves compared with Nipponbare. However, grain features and sugar content suggested limited sucrose mobilization to grains in the wild rice due to vasculature and sucrose transporter functions. Low cell wall invertase activity and high sucrose synthase cleavage activity followed by higher expression of cellulose synthase genes in O. australiensis stem indicated that it utilized photosynthates preferentially for the synthesis of structural carbohydrates, resulting in high biomass. In contrast, source-sink relationships favored high grain yield in Nipponbare via accumulation of transitory starch in the stem, due to higher expression of starch biosynthetic genes, which is mobilized to panicles at the grain filling stage. Thus, vascular features, sucrose transport, and functions of sugar metabolic enzymes explained the differences in source-sink relationships between Nipponbare and O. australiensis.


Assuntos
Oryza , Carbono , Grão Comestível , Oryza/genética , Proteínas de Plantas/genética , Sacarose
16.
Physiol Plant ; 171(4): 620-637, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32940908

RESUMO

Abiotic stresses, including drought and salinity, negatively affect plant development and physiology at molecular and metabolic levels. Sucrose transport, mediating distribution of photosynthates in plant, is a key physiological process impacted by drought and salinity stresses, as sucrose is a prime energy and signaling molecule as well as an osmolyte. Therefore, understanding the effects of abiotic stresses on sucrose transport and transporters, and underlying genetic and molecular mechanisms, is imperative to maintain sugar homeostasis in plants under stress. Here, we investigated the effects of drought and salinity stresses on sucrose transport and distribution, and on expression levels of genes encoding Sugars Will Eventually be Exported Transporters (SWEETs), along with a potential transcription factor regulating SWEET expression in rice. We observed that drought and salinity stresses increased the sucrose content in leaf and root tissues and in phloem sap of rice indica varieties. Expression analyses of SWEET genes and histochemical analysis of ß-glucuronidase-reporter transgenic plants suggested that OsSWEET13 and OsSWEET15 are major SWEET transporters regulating the sucrose transport and levels in response to the abiotic stresses. Transactivation analyses showed that an abscisic acid (ABA)-responsive transcription factor OsbZIP72 directly binds to the promoters of OsSWEET13 and OsSWEET15 and activates their expression. Taken together, the results showed that the higher expressions of OsSWEET13 and OsSWEET15 genes, induced by binding of an ABA-responsive transcription factor OsbZIP72 to the promoters, potentially modulate sucrose transport and distribution in response to the abiotic stresses. The mechanism could possibly be targeted for maintaining sugar homeostasis in rice under drought and salinity stresses.


Assuntos
Ácido Abscísico , Oryza , Secas , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Estresse Salino , Estresse Fisiológico , Sacarose
17.
Xenobiotica ; 51(3): 335-344, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33287643

RESUMO

Polybrominated diphenyl ethers (PBDEs) levels in environmental matrices have generally declined following their phaseout as flame retardants. The objective of this study was to determine the absorption, distribution, metabolism, and excretion of three persistent PBDEs in laying hens and their transfer into eggs. Laying hens (n = 4 per congener) received a single oral dose of BDE-99, -153, or -209 and eggs and excreta were collected daily for 7 days, then tissues were collected and analysed. Cumulative BDE-209 excretion was 93% of dose, and bioavailability was approximately 17%. Lesser amounts of BDE-99 (41%) and -153 (26%) were excreted with bioavailabilities of 87% and 79%, respectively. Phenolic metabolites were observed in excreta extracts from BDE-99 dosed birds. Cumulative transfers based on bioavailability of BDE-99, -153, and -209 to eggs were 17%, 34%, and 15%, respectively. Egg residues were primarily present in yolk (12.3%, 23.5%, and 2.1% of the total dose for BDE-99, -153, and -209, respectively). Adipose, skin, ova, intestine, and thigh muscle contained the highest levels of radioactive tissue residues. These studies demonstrate movement of PBDE residues into edible tissues and eggs of laying hens.


Assuntos
Retardadores de Chama/metabolismo , Éteres Difenil Halogenados/metabolismo , Óvulo/química , Animais , Galinhas , Feminino , Éteres Difenil Halogenados/análise
18.
Arch Environ Contam Toxicol ; 80(2): 499-506, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33523258

RESUMO

Infant skin is highly absorptive and sensitive to exposure from external agents (microbes, toxicants, heat, cold, etc.). Many specialized infant skincare products are currently commercially available. Although the manufacturers claim that their products are mild enough to suit the infant skin, these products need to be studied for their safety. Using animal models to examine the safety of the ever-increasing number of skincare products is not economically or logistically feasible. To overcome this problem, we suggest using a battery of microbial bioassays as a robust system for monitoring the mutagenic potential of skincare products. We picked popular infant skincare products from the Indian market and assessed them by using a battery of three microbial mutagenicity bioassays. Most of them showed significant and reproducible mutagenic potential. Our study results raise concerns about regular use of infant products and emphasize the need to enforce strict regulations for the manufacturing and safety assessment of infant products.


Assuntos
Bioensaio , Cosméticos/toxicidade , Exposição Ambiental/estatística & dados numéricos , Mutagênicos/toxicidade , Animais , Humanos , Lactente , Modelos Animais , Higiene da Pele/métodos , Testes Cutâneos
19.
BMC Plant Biol ; 20(1): 19, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931716

RESUMO

BACKGROUND: Young wheat plants are continuously exposed to herbivorous insect attack. To reduce insect damage and maintain their growth, plants evolved different defense mechanisms, including the biosynthesis of deterrent compounds named benzoxazinoids, and/or trichome formation that provides physical barriers. It is unclear whether both of these mechanisms are equally critical in providing an efficient defense for wheat seedlings against aphids-an economically costly pest in cereal production. RESULTS: In this study, we compared the transcriptome, metabolome, benzoxazinoids, and trichome density of three selected wheat genotypes, with a focus on differences related to defense mechanisms. We chose diverse wheat genotypes: two tetraploid wheat genotypes, domesticated durum 'Svevo' and wild emmer 'Zavitan,' and one hexaploid bread wheat, 'Chinese Spring.' The full transcriptomic analysis revealed a major difference between the three genotypes, while the clustering of significantly different genes suggested a higher similarity between the two domesticated wheats than between either and the wild wheat. A pathway enrichment analysis indicated that the genes associated with primary metabolism, as well as the pathways associated with defense such as phytohormones and specialized metabolites, were different between the three genotypes. Measurement of benzoxazinoid levels at the three time points (11, 15, and 18 days after germination) revealed high levels in the two domesticated genotypes, while in wild emmer wheat, they were below detection level. In contrast to the benzoxazinoid levels, the trichome density was dramatically higher in the wild emmer than in the domesticated wheat. Lastly, we tested the bird cherry-oat aphid's (Rhopalosiphum padi) performance and found that Chinese Spring is more resistant than the tetraploid genotypes. CONCLUSIONS: Our results show that benzoxazinoids play a more significant defensive role than trichomes. Differences between the abundance of defense mechanisms in the wild and domesticated plants were observed in which wild emmer possesses high physical defenses while the domesticated wheat genotypes have high chemical defenses. These findings provide new insights into the defense adaptations of wheat plants against aphids.


Assuntos
Afídeos/fisiologia , Benzoxazinas/metabolismo , Imunidade Vegetal/genética , Triticum/genética , Animais , Domesticação , Perfilação da Expressão Gênica , Genótipo , Herbivoria , Metabolômica , Imunidade Vegetal/fisiologia , Tricomas/anatomia & histologia , Triticum/imunologia
20.
Nitric Oxide ; 104-105: 36-43, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32891753

RESUMO

It is well established that myoglobin supports mitochondrial respiration through the storage and transport of oxygen as well as through the scavenging of nitric oxide. However, during ischemia/reperfusion (I/R), myoglobin and mitochondria both propagate myocardial injury through the production of oxidants. Nitrite, an endogenous signaling molecule and dietary constituent, mediates potent cardioprotection after I/R and this effect relies on its interaction with both myoglobin and mitochondria. While independent mechanistic studies have demonstrated that nitrite-mediated cardioprotection requires the presence of myoglobin and the post-translational S-nitrosation of critical cysteine residues on mitochondrial complex I, it is unclear whether myoglobin directly catalyzes the S-nitrosation of complex I or whether mitochondrial-dependent nitrite reductase activity contributes to S-nitrosation. Herein, using purified myoglobin and isolated mitochondria, we characterize and directly compare the nitrite reductase activities of mitochondria and myoglobin and assess their contribution to mitochondrial S-nitrosation. We demonstrate that myoglobin is a significantly more efficient nitrite reductase than isolated mitochondria. Further, deoxygenated myoglobin catalyzes the nitrite-dependent S-nitrosation of mitochondrial proteins. This reaction is enhanced in the presence of oxidized (Fe3+) myoglobin and not significantly affected by inhibitors of mitochondrial respiration. Using a Chinese Hamster Ovary cell model stably transfected with human myoglobin, we show that both myoglobin and mitochondrial complex I expression are required for nitrite-dependent attenuation of cell death after anoxia/reoxygenation. These data expand the understanding of myoglobin's role both as a nitrite reductase to a mediator of S-nitrosation and as a regulator of mitochondrial function, and have implications for nitrite-mediated cardioprotection after I/R.


Assuntos
Citoproteção/fisiologia , Mitocôndrias/metabolismo , Mioglobina/metabolismo , Nitrito Redutases/metabolismo , Nitritos/metabolismo , Animais , Células CHO , Hipóxia Celular/fisiologia , Cricetulus , Cisteína/química , Complexo I de Transporte de Elétrons/química , Complexo I de Transporte de Elétrons/metabolismo , Humanos , Proteínas Mitocondriais/química , Proteínas Mitocondriais/metabolismo , Nitrosação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA