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1.
J Undergrad Neurosci Educ ; 22(3): A246-A255, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39355663

RESUMO

With grant support from the Research Experience for Undergraduates (REU) program funded by the National Science Foundation (NSF) and the Awards to Stimulate and Support Undergraduate Research Experiences (ASSURE) program funded by the Department of Defense (DoD) Air Force Office of Scientific Research (AFOSR), we established a program intended to increase the number of underrepresented racial and ethnic minority (URM) and first-generation undergraduate students successfully applying to neuroscience and other STEM-related graduate programs. The Neuroscience Techniques and Research Training (NeuroSTART) Program aimed to increase the number of undergraduate students from the Memphis area involved in behavioral neuroscience research. In this two-semester program, students completed an empirical research project in a neuroscience lab, received individual mentoring from neuroscience faculty, became part of a STEM network, presented at research conferences, and attended specialized professional development seminars. In two cohorts of 15 students, 4 are PhD students in neuroscience-related programs or in medical school (27%), 4 are employed in neuroscience-related research facilities (27%), 3 are employed as clinical assistants (20%), and 1 is employed in the IT field (7%). The remaining three recently graduated and are planning a gap year prior to applying for admission to graduate/medical school. The Memphis NeuroSTART program has provided valuable training to participants, making them competitive applicants for jobs in the health sciences and for admittance into graduate neuroscience programs. By providing this training to first-generation and URM students, the broader impact of this program was an increase in the diversity of the health sciences workforce, particularly those specializing in neuroscience-related research and treatment.

2.
EMBO J ; 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39242788

RESUMO

Monoamine neurotransmitters generated by de novo synthesis are rapidly transported and stored into synaptic vesicles at axon terminals. This transport is essential both for sustaining synaptic transmission and for limiting the toxic effects of monoamines. Here, synthesis of the monoamine histamine by histidine decarboxylase (HDC) and subsequent loading of histamine into synaptic vesicles are shown to be physically and functionally coupled within Drosophila photoreceptor terminals. This process requires HDC anchoring to synaptic vesicles via interactions with N-ethylmaleimide-sensitive fusion protein 1 (NSF1). Disassociating HDC from synaptic vesicles disrupts visual synaptic transmission and causes somatic accumulation of histamine, which leads to retinal degeneration. We further identified a proteasome degradation system mediated by the E3 ubiquitin ligase, purity of essence (POE), which clears mislocalized HDC from the soma, thus eliminating the cytotoxic effects of histamine. Taken together, our results reveal a dual mechanism for translocation and degradation of HDC that ensures restriction of histamine synthesis to axonal terminals and at the same time rapid loading into synaptic vesicles. This is crucial for sustaining neurotransmission and protecting against cytotoxic monoamines.

3.
Environ Monit Assess ; 196(10): 912, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39251525

RESUMO

The Guanabara Bay hydrographic region (GBHR) has served as a central hub for human settlement and resource utilization throughout Brazil's history. However, the region's high population density and intense industrial activity have come at a cost, leading to a significant decline in water quality. This work aimed to identify homogeneous regions in GBHR according to water quality parameters in dry and rainy periods. The following water quality monitoring variables were monitored at 49 gauge stations: total phosphorus (TP), nitrate (NO3-), dissolved oxygen (DO), hydrogenionic potential (pH), turbidity (Turb), thermotolerant coliforms (TCol), total dissolved solids (TDS), biochemical oxygen demand (BOD), water temperature (Tw), and air temperature (Ta). The statistical analysis consisted of determining principal components, cluster analysis, seasonal differences, and Spearman's correlation. The water quality parameter correlations were not expressively influenced by seasonality, but there are differences in the concentrations of these parameters in the dry and rainy periods. In the dry period, urban pressure on water quality is mainly due to fecal coliforms. The resulting clusters delimited areas under urban, agricultural, and forestry influence. Clusters located in areas with high demographic density showed high concentrations of TCol and TP, while clusters influenced by forestry and agriculture had better water quality. In the rainy season, clusters with urban influence showed problems with TCol and TP, in addition to some characteristics in each group, such as high TDS, NO3-, and BOD. Forested areas showed high DO, and clusters under agricultural influence had higher concentrations of TCol, BOD, and NO3- concerning forested regions. The troubling state of sanitation in GBHR occurs in metropolitan regions due to lack of a formal sanitation system.


Assuntos
Monitoramento Ambiental , Qualidade da Água , Brasil , Monitoramento Ambiental/métodos , Baías , Poluentes Químicos da Água/análise , Fósforo/análise , Nitratos/análise , Estações do Ano , Análise Multivariada
4.
bioRxiv ; 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39257774

RESUMO

SNARE proteins drive membrane fusion as their core domains zipper into a parallel four-helix bundle1,2. After fusion, these bundles are disassembled by the AAA+ protein Sec18/NSF and its adaptor Sec17/ α-SNAP3,4 to make them available for subsequent rounds of membrane fusion. SNARE domains are often flanked by C-terminal transmembrane or N-terminal domains5. Previous structures of the NSF-α-SNAP-SNARE complex revealed SNARE domain threaded through the D1 ATPase ring6, posing a topological constraint as SNARE transmembrane domains would prevent complete substrate threading as suggested for other AAA+ systems7. Here, in vivo mass-spectrometry reveals N-terminal SNARE domain interactions with Sec18, exacerbating this topological issue. Cryo-EM structures of a yeast SNARE complex, Sec18, and Sec17 in a non-hydrolyzing condition shows SNARE Sso1 threaded through the D1 and D2 ATPase rings of Sec18, with its folded, N-terminal Habc domain interacting with the D2 ring. This domain does not unfold during Sec18/NSF activity. Cryo-EM structures under hydrolyzing conditions revealed substrate-released and substrate-free states of Sec18 with a coordinated opening in the side of the ATPase rings. Thus, Sec18/NSF operates by substrate side-loading and unloading topologically constrained SNARE substrates.

5.
Theriogenology ; 229: 53-65, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39163803

RESUMO

In assisted fertility protocols, in vitro culture conditions mimic physiological conditions to preserve gametes in the best conditions. After collection, oocytes are maintained in a culture medium inside the incubator until in vitro fertilization (IVF) is performed. This time outside natural and physiological conditions exposes oocytes to an oxidative stress that renders in vitro aging. It has been described that in vitro aging produces a spontaneous cortical granule (CG) release decreasing the fertilization rate of oocytes. Nevertheless, this undesirable phenomenon has not been investigated, let alone prevented. In this work, we characterized the spontaneous CG secretion in in vitro aged oocytes. Using immunofluorescence indirect, quantification, and functional assays, we showed that the expression of regulatory proteins of CG exocytosis was affected. Our results demonstrated that in vitro oocyte aging by 4 and 8 h altered the expression and localization of alpha-SNAP and reduced the expression of NSF and Complexin. These alterations were prevented by supplementing culture medium with dithiothreitol (DTT), which in addition to having a protective effect on those proteins, also had an unexpected effect on the actin cytoskeleton. Indeed, DTT addition thickened the cortical layer of fibrillar actin. Both DTT effects, together, prevented the spontaneous secretion of CG and recovered the IVF rate in in vitro aged oocytes. We propose the use of DTT in culture media to avoid the spontaneous CG secretion and to improve the success rate of IVF protocols in in vitro aged oocytes.


Assuntos
Citoesqueleto de Actina , Ditiotreitol , Exocitose , Oócitos , Animais , Oócitos/efeitos dos fármacos , Exocitose/efeitos dos fármacos , Camundongos , Ditiotreitol/farmacologia , Citoesqueleto de Actina/efeitos dos fármacos , Citoesqueleto de Actina/metabolismo , Feminino , Grânulos Citoplasmáticos/metabolismo , Grânulos Citoplasmáticos/efeitos dos fármacos , Fertilização in vitro/veterinária , Senescência Celular/efeitos dos fármacos
6.
Acta Neuropathol Commun ; 12(1): 130, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39135092

RESUMO

BACKGROUND: Optical coherence tomography (OCT) is a non-invasive technique to measure retinal layer thickness, providing insights into retinal ganglion cell integrity. Studies have shown reduced retinal nerve fibre layer (RNFL) and ganglion cell inner plexiform layer (GCIPL) thickness in Parkinson's disease (PD) patients. However, it is unclear if there is a common genetic overlap between the macula and peripapillary estimates with PD and if the genetic risk of PD is associated with changes in ganglion cell integrity estimates in young adults. METHOD: Western Australian young adults underwent OCT imaging. Their pRNFL, GCIPL, and overall retinal thicknesses were recorded, as well as their longitudinal changes between ages 20 and 28. Polygenic risk scores (PRS) were estimated for each participant based on genome-wide summary data from the largest PD genome-wide association study conducted to date. We further evaluated whether PD PRS was associated with changes in thickness at a younger age. To evaluate the overlap between retinal integrity estimates and PD, we annotated and prioritised genes using mBAT-combo and performed colocalisation through the GWAS pairwise method and HyPrColoc. We used a multi-omic approach and single-cell expression data of the retina and brain through a Mendelian randomisation framework to evaluate the most likely causal genes. Genes prioritised were analysed for missense variants that could have a pathogenic effect using AlphaMissense. RESULTS: We found a significant association between the Parkinson's disease polygenic risk score (PD PRS) and changes in retinal thickness in the macula of young adults assessed at 20 and 28 years of age. Gene-based analysis identified 27 genes common to PD and retinal integrity, with a notable region on chromosome 17. Expression analyses highlighted NSF, CRHR1, and KANSL1 as potential causal genes shared between PD and ganglion cell integrity measures. CRHR1 showed consistent results across multiple omics levels. INTERPRETATION: Our findings suggest that retinal measurements, particularly in young adults, could be a potential marker for PD risk, indicating a genetic overlap between retinal structural integrity and PD. The study highlights specific genes and loci, mainly on chromosome 17, as potential shared etiological factors for PD and retinal changes. Our results highlight the importance of further longitudinal studies to validate retinal structural metrics as early indicators of PD predisposition.


Assuntos
Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Doença de Parkinson , Tomografia de Coerência Óptica , Humanos , Doença de Parkinson/genética , Doença de Parkinson/patologia , Feminino , Masculino , Adulto , Adulto Jovem , Predisposição Genética para Doença/genética , Macula Lutea/patologia , Macula Lutea/diagnóstico por imagem , Células Ganglionares da Retina/patologia , Herança Multifatorial/genética
7.
Mil Med Res ; 11(1): 49, 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39044298

RESUMO

BACKGROUND: The development of ketamine-like rapid antidepressants holds promise for enhancing the therapeutic efficacy of depression, but the underlying cellular and molecular mechanisms remain unclear. Implicated in depression regulation, the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is investigated here to examine its role in mediating the rapid antidepressant response. METHODS: The onset of antidepressant response was assessed through depression-related behavioral paradigms. The signaling mechanism of PACAP in the hippocampal dentate gyrus (DG) was evaluated by utilizing site-directed gene knockdown, pharmacological interventions, or optogenetic manipulations. Overall, 446 mice were used for behavioral and molecular signaling testing. Mice were divided into control or experimental groups randomly in each experiment, and the experimental manipulations included: chronic paroxetine treatments (4, 9, 14 d) or a single treatment of ketamine; social defeat or lipopolysaccharides-injection induced depression models; different doses of PACAP (0.4, 2, 4 ng/site; microinjected into the hippocampal DG); pharmacological intra-DG interventions (CALM and PACAP6-38); intra-DG viral-mediated PACAP RNAi; and opotogenetics using channelrhodopsins 2 (ChR2) or endoplasmic natronomonas halorhodopsine 3.0 (eNpHR3.0). Behavioral paradigms included novelty suppressed feeding test, tail suspension test, forced swimming test, and sucrose preference test. Western blotting, ELISA, or quantitative real-time PCR (RT-PCR) analysis were used to detect the expressions of proteins/peptides or genes in the hippocampus. RESULTS: Chronic administration of the slow-onset antidepressant paroxetine resulted in an increase in hippocampal PACAP expression, and intra-DG blockade of PACAP attenuated the onset of the antidepressant response. The levels of hippocampal PACAP expression were reduced in both two distinct depression animal models and intra-DG knockdown of PACAP induced depression-like behaviors. Conversely, a single infusion of PACAP into the DG region produced a rapid and sustained antidepressant response in both normal and chronically stressed mice. Optogenetic intra-DG excitation of PACAP-expressing neurons instantly elicited antidepressant responses, while optogenetic inhibition induced depression-like behaviors. The longer optogenetic excitation/inhibition elicited the more sustained antidepressant/depression-like responses. Intra-DG PACAP infusion immediately facilitated the signaling for rapid antidepressant response by inhibiting calcium/calmodulin-dependent protein kinase II (CaMKII)-eukaryotic elongation factor 2 (eEF2) and activating the mammalian target of rapamycin (mTOR). Pre-activation of CaMKII signaling within the DG blunted PACAP-induced rapid antidepressant response as well as eEF2-mTOR-brain-derived neurotrophic factor (BDNF) signaling. Finally, acute ketamine treatment upregulated hippocampal PACAP expression, whereas intra-DG blockade of PACAP signaling attenuated ketamine's rapid antidepressant response. CONCLUSIONS: Activation of hippocampal PACAP signaling induces a rapid antidepressant response through the regulation of CaMKII inhibition-governed eEF2-mTOR-BDNF signaling.


Assuntos
Depressão , Hipocampo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase , Transdução de Sinais , Animais , Masculino , Camundongos , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Comportamento Animal/efeitos dos fármacos , Depressão/tratamento farmacológico , Modelos Animais de Doenças , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Paroxetina/farmacologia , Paroxetina/uso terapêutico , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/metabolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/farmacologia , Transdução de Sinais/efeitos dos fármacos
8.
Front Aging Neurosci ; 16: 1401038, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38919602

RESUMO

Necroptosis is implicated in the pathogenesis of ischemic stroke. However, the mechanism underlying the sequential recruitment of receptor-interacting protein kinase 1 (RIPK1) and N-ethylmaleimide-sensitive fusion ATPase (NSF) in initiating necroptosis remains poorly understood, and the role of NSF in ischemic stroke is a subject of controversy. Here, we utilized a recently emerging RNA-targeting CRISPR system known as CasRx, delivered by AAVs, to knockdown Ripk1 mRNA and Nsf mRNA around the ischemic brain tissue. This approach resulted in a reduction in infarct and edema volume, as well as an improvement in neurological deficits assessed by Bederson score, RotaRod test, and Adhesive removal test, which were achieved by RIPK1/receptor-interacting protein kinase 3/mixed lineage kinase domain-like protein signaling pathway involved in neuronal necroptosis. In conclusion, the downregulation of Ripk1 mRNA and Nsf mRNA mediated by CRISPR-CasRx holds promise for future therapeutic applications aimed at ameliorating cerebral lesions and neurological deficits following the ischemic stroke.

9.
Cell Rep ; 43(5): 114026, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38809756

RESUMO

Synaptic vesicle docking and priming are dynamic processes. At the molecular level, SNAREs (soluble NSF attachment protein receptors), synaptotagmins, and other factors are critical for Ca2+-triggered vesicle exocytosis, while disassembly factors, including NSF (N-ethylmaleimide-sensitive factor) and α-SNAP (soluble NSF attachment protein), disassemble and recycle SNAREs and antagonize fusion under some conditions. Here, we introduce a hybrid fusion assay that uses synaptic vesicles isolated from mouse brains and synthetic plasma membrane mimics. We included Munc18, Munc13, complexin, NSF, α-SNAP, and an ATP-regeneration system and maintained them continuously-as in the neuron-to investigate how these opposing processes yield fusogenic synaptic vesicles. In this setting, synaptic vesicle association is reversible, and the ATP-regeneration system produces the most synchronous Ca2+-triggered fusion, suggesting that disassembly factors perform quality control at the early stages of synaptic vesicle association to establish a highly fusogenic state. We uncovered a functional role for Munc13 ancillary to the MUN domain that alleviates an α-SNAP-dependent inhibition of Ca2+-triggered fusion.


Assuntos
Proteínas do Tecido Nervoso , Vesículas Sinápticas , Vesículas Sinápticas/metabolismo , Animais , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Domínios Proteicos , Cálcio/metabolismo , Fusão de Membrana , Exocitose , Proteínas SNARE/metabolismo , Camundongos Endogâmicos C57BL , Neurônios/metabolismo
10.
J Am Coll Health ; : 1-13, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38743434

RESUMO

Objective: We examined how mentorship, remote participation, and COVID-19 challenges were associated with the mental health of college students participating in summer research programs. Participants: Participants were students participating in 78 National Science Foundation (NSF) Research Experiences for Undergraduate (REU) Sites during Summer 2022 (n = 516 students). Methods: We used multivariable generalized estimating equations that account for clustering by REU Site. Results: Students with more competent mentors had reduced depression severity. Students who spent ≥25% of their time doing remote research or ≥25% of their time in remote meetings and workshops had greater depression severity. Remote research was also associated with anxiety severity. Having a COVID-19 challenge that impacted students' research experience was associated with increases in depression and anxiety severity. Conclusions: Results suggest potential interventions: implement strategies to boost mentor competency and scaffold a support system into summer research programs to enhance student wellbeing. Additional research on remote engagement is needed.

11.
J Biol Chem ; 300(3): 105782, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38395304

RESUMO

Intracellular vesicle fusion is driven by the soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) and their cofactors, including Sec1/Munc18 (SM), α-SNAP, and NSF. α-SNAP and NSF play multiple layers of regulatory roles in the SNARE assembly, disassembling the cis-SNARE complex and the prefusion SNARE complex. How SM proteins coupled with NSF and α-SNAP regulate SNARE-dependent membrane fusion remains incompletely understood. Munc18c, an SM protein involved in the exocytosis of the glucose transporter GLUT4, binds and activates target (t-) SNAREs to accelerate the fusion reaction through a SNARE-like peptide (SLP). Here, using an in vitro reconstituted system, we discovered that α-SNAP blocks the GLUT4 SNAREs-mediated membrane fusion. Munc18c interacts with t-SNAREs to displace α-SNAP, which overcomes the fusion inhibition. Furthermore, Munc18c shields the trans-SNARE complex from NSF/α-SNAP-mediated disassembly and accelerates SNARE-dependent fusion kinetics in the presence of NSF and α-SNAP. The SLP in domain 3a is indispensable in Munc18c-assisted resistance to NSF and α-SNAP. Together, our findings demonstrate that Munc18c protects the prefusion SNARE complex from α-SNAP and NSF, promoting SNARE-dependent membrane fusion through its SLP.


Assuntos
Fusão de Membrana , Proteínas Munc18 , Proteínas SNARE , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida , Fusão de Membrana/fisiologia , Proteínas Munc18/metabolismo , Proteínas Sensíveis a N-Etilmaleimida/genética , Proteínas Sensíveis a N-Etilmaleimida/metabolismo , Organelas/metabolismo , Peptídeos/metabolismo , Proteínas SNARE/metabolismo , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida/genética , Animais , Camundongos
12.
Magn Reson Imaging ; 107: 120-129, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38215955

RESUMO

The use of conventional gadolinium(Gd)-based contrast agents in magnetic resonance imaging (MRI) poses a significant risk of Nephrogenic Systemic Fibrosis (NSF) syndrome in patients with impaired renal function (grades 4 and 5). To address this issue, a new study has introduced a novel metabolic Gadolinium oxide nanoparticle (Gd2O3 NPs) coated with ß-cyclodextrin (ßCD). The study aims to investigate NSF syndrome by quantifying tissue Gd deposition biodistribution in renal impairment rats using MR molecular imaging. This is the first study of its kind to use this approach. A group of 20 rats were divided into four groups, each containing five rats that underwent 5/6 nephrectomy. The rats received 12 intravenous injections of a novel homemade synthesized gadolinium oxide polycyclodextrin (Gd2O3@PCD) at a dose of 0.1 mmol/kg, conventional contrast agents (CAs) drugs of Omniscan (Gd-DTPA-BMA) and Dotarem (Gd-DOTA), at a dose of 2.5 mmol/kg, and 250 µl saline for two injections per week during six weeks. T1-weighted MR imaging was performed before the injections and once a week for six weeks to quantify Gd deposition in four different organs (skin, liver, heart, and lung) in rats using inductively coupled plasma mass spectrometry (ICP-MS). The relationship between Signal-to-Noise Ratio (SNR) and biodistribution of Gd deposition due to NSF-induced syndrome was also calculated. The results of the study showed that the Gd concentrations in tissues were significantly higher in the Gd2O3@PCD group compared to the other groups, without any significant histopathological changes (P < 0.05). In the Gd2O3@PCD group, Gd was mainly deposited in the skin, followed by the liver, lung, and heart, without any symptoms of thickening or hardening of the skin. The Gd concentrations in the skin, liver, lung, and heart were significantly lower in the Dotarem group than in the Omniscan group (P < 0.05). In the histopathological examinations, the Omniscan group showed increased cellularity in the dermis. A significant hyperintensity was observed in the Gd2O3@PCD-treated rats compared to the Dotarem and Omniscan groups in the liver, heart, and lung. Compared to conventional Gd-based CAs, the novel metabolically Gd2O3@PCD with increased SNR, biosafety, and a considerably lower probability of developing NSF, has potential applicability for diagnosing patients with renal diseases in clinical MR Molecular Imaging (MRMI).


Assuntos
Meglumina , Nanopartículas , Dermopatia Fibrosante Nefrogênica , Compostos Organometálicos , Insuficiência Renal , beta-Ciclodextrinas , Humanos , Ratos , Animais , Meios de Contraste/efeitos adversos , Dermopatia Fibrosante Nefrogênica/induzido quimicamente , Gadolínio/efeitos adversos , Ratos Wistar , Distribuição Tecidual , Gadolínio DTPA , Insuficiência Renal/induzido quimicamente , Insuficiência Renal/metabolismo , Insuficiência Renal/patologia , beta-Ciclodextrinas/efeitos adversos , Imageamento por Ressonância Magnética , Imagem Molecular
13.
Pest Manag Sci ; 80(3): 1645-1653, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37986260

RESUMO

BACKGROUND: Tolpyralate, a relatively new inhibitor of 4-hydroxyphenylpyruvate dioxygenase (HPPD), is registered for postemergence use in all types of corn (Zea mays L.) and has a record of excellent crop tolerance. A report of severe crop injury to sweet corn inbred (XSEN187) led to the following objectives: (i) determine whether sensitivity to tolpyralate in XSEN187 exists, and if confirmed, (ii) determine the genetic basis of tolpyralate sensitivity, and (iii) screen other corn germplasm for sensitivity to tolpyralate. RESULTS: Inbred XSEN187 was confirmed sensitive to tolpyralate. Inclusion of methylated seed oil or nonionic surfactant in the spray volume was necessary for severe crop injury. Tolpyralate sensitivity in XSEN187 is not conferred by alleles at Nsf1, a cytochrome P450-encoding gene (CYP81A9) conferring tolerance to many corn herbicides. Evidence suggests that tolpyralate sensitivity in XSEN187 is conferred by a single gene mapped to the Chr05: 283 240-1 222 909 bp interval. Moreover, tolpyralate sensitivity was observed in 48 other sweet corn and field corn inbreds. CONCLUSIONS: Severe sensitivity to tolpyralate exists in sweet corn and field corn germplasm when the herbicide is applied according to label directions. Whereas the corn response to several other herbicides, including HPPD-inhibitors, is conferred by the Nsf1 locus, corn sensitivity to tolpyralate is the result of a different locus. The use of tolpyralate should consider herbicide tolerance in inbred lines from which corn hybrids were derived, whereas alleles that render corn germplasm sensitive to tolpyralate should be eliminated from breeding populations, inbreds, and commercial cultivars. © 2023 Illinois Foundation Seeds, Inc and The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.


Assuntos
4-Hidroxifenilpiruvato Dioxigenase , Herbicidas , Humanos , Zea mays/genética , Herbicidas/farmacologia , Melhoramento Vegetal , Illinois
14.
Toxicol Mech Methods ; : 1-17, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-38031359

RESUMO

The Threshold of Toxicological Concern (TTC) is an approach for assessing the safety of chemicals with low levels of exposure for which limited toxicology data are available. The original TTC criteria were derived for oral exposures from a distributional analysis of a dataset of 613 chemicals that identified 5th percentile no observed effect level (NOEL) values grouped within three tiers of compounds having specific structural functional groups and/or toxic potencies known as Cramer I, II and III classifications. Subsequent assessments of the TTC approach have established current thresholds to be scientifically robust. While the TTC has gained acknowledgment and acceptance by many regulatory agencies and organizations, use of the TTC approach in evaluating drinking water chemicals has been limited. To apply the TTC concept to drinking water chemicals, an exposure-based approach that incorporates the current weight of evidence for the target chemical is presented. Such an approach provides a comparative point of departure to the 5th percentile TTC NOEL using existing data, while conserving the allocation of toxicological resources for quantitative risk assessment to chemicals with greater exposure or toxicity. This approach will be considered for incorporation into NSF/ANSI/CAN 600, a health effects standard used in the safety evaluation of chemicals present in drinking water from drinking water contact additives and materials certified to NSF/ANSI/CAN 60 and 61, respectively.

15.
Adv Neurobiol ; 33: 63-118, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37615864

RESUMO

Neurotransmitters are stored in small membrane-bound vesicles at synapses; a subset of synaptic vesicles is docked at release sites. Fusion of docked vesicles with the plasma membrane releases neurotransmitters. Membrane fusion at synapses, as well as all trafficking steps of the secretory pathway, is mediated by SNARE proteins. The SNAREs are the minimal fusion machinery. They zipper from N-termini to membrane-anchored C-termini to form a 4-helix bundle that forces the apposed membranes to fuse. At synapses, the SNAREs comprise a single helix from syntaxin and synaptobrevin; SNAP-25 contributes the other two helices to complete the bundle. Unc13 mediates synaptic vesicle docking and converts syntaxin into the permissive "open" configuration. The SM protein, Unc18, is required to initiate and proofread SNARE assembly. The SNAREs are then held in a half-zippered state by synaptotagmin and complexin. Calcium removes the synaptotagmin and complexin block, and the SNAREs drive vesicle fusion. After fusion, NSF and alpha-SNAP unwind the SNAREs and thereby recharge the system for further rounds of fusion. In this chapter, we will describe the discovery of the SNAREs, their relevant structural features, models for their function, and the central role of Unc18. In addition, we will touch upon the regulation of SNARE complex formation by Unc13, complexin, and synaptotagmin.


Assuntos
Fusão de Membrana , Proteínas SNARE , Humanos , Vesículas Sinápticas , Transmissão Sináptica , Sinaptotagminas
16.
Water Res ; 244: 120425, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37544118

RESUMO

Properly certified NSF/ANSI 53 water filters are distributed as a temporary measure to protect residents from risk of exposure to elevated lead (Pb) levels resulting from water system changes and various activities. Water consumers and other stakeholders have raised questions on the performance of these filters in field settings, particularly in cases where water Pb levels exceeded the NSF/ANSI 53 challenge water level of 150 µg/L and when Pb phosphate nanoparticles (≤ 200 nm) were present in drinking water. This literature review summarizes findings from 23 studies that evaluated the ability of NSF/ANSI 53 post-2007 certified filters to reduce soluble and/or particulate Pb from water. The studies in total examined 1,486 faucet-mounted, 25 under-the-sink, and 167 pitcher filters, with 1,528 filters used in field studies and 150 filters in laboratory studies. This review found that filter performance varied with different filter type, test water source, and initial unfiltered total Pb concentration. 99% (1,512/1,528) of the filters used in field studies removed Pb to at or below the certification benchmark of pre-2019, 10 µg/L or post-2019, 5 µg/L. In contrast, 61% (91/150) of the filters used in laboratory studies reduced Pb to the benchmark. Laboratory filters were often tested under conditions beyond what they were certified to handle. Pb concentration, particle form and size, improper operation and maintenance of certified water filters were attributed to reported filter failures. This information is intended to help water utilities, regulators, and others make decisions regarding the deployment of water filters to the public when drinking water Pb exposure concerns have been raised.


Assuntos
Água Potável , Poluentes Químicos da Água , Purificação da Água , Chumbo , Purificação da Água/métodos , Minerais , Poluentes Químicos da Água/análise , Filtração
17.
Eur J Radiol Open ; 11: 100503, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37456927

RESUMO

Contrast agents is used in magnetic resonance imaging (MRI) to improve the visibility of the details of the organ structures. Gadolinium-based contrast agent (GBCA) has been used since 1988 in MRI for diagnostic and follow-up of patients, the gadolinium good properties make it an effective choice for enhance the signal in MRI by increase its intensity and shortening the relaxation time of the proton. Recently, many studies show a gadolinium deposition in different human organs due to release of free gadolinium various body organs or tissue, which led to increased concern about the use of gadolinium agents, in this study, the potential diseases that may affect the patient and side effects that appear on the patient and related to accumulation of gadolinium were clarified, the study focused on the organs such as brain and bones in which gadolinium deposition was found and the lesions associated with it, and the diseases associated with gadolinium retention includes Nephrogenic Systemic Fibrosis (NSF) and Gadolinium deposition disease (GDD). Some studies tended to improve the contrast agents by developing a new non-gadolinium agents or development of next-generation gadolinium agents. In this review article the latest knowledge about MRI contrast agent.

18.
Toxicol Mech Methods ; : 1-5, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37254444

RESUMO

Third-party certification to drinking water product consensus standards is how products for potable water systems are deemed suitable for public health and safety in North America. Drinking water product consensus standards are a type of standard developed through a process that includes participation from expert volunteers and requires general agreement from all stakeholders. Certification to drinking water product consensus standards is required via plumbing codes and state or local regulations in most of the United States and Canada, making third-party certification essential for products intended for sale and installation in North America. Third-party certification bodies (CBs) test and certify products to these drinking water product consensus standards through an evaluation process that includes a thorough review of each product's composition, laboratory testing, and inspection of each facility where the product is manufactured. Products that comply with the consensus standard requirements are entitled to bear a certification mark that demonstrates their suitability for use in potable water systems. Drinking water product standards developed by NSF reference NSF/ANSI/CAN 600: Health Effects Evaluation and Criteria for Chemicals in Drinking Water for the toxicological criteria to evaluate chemical leachates derived from material extraction testing. Here, we review the third-party product certification process for evaluating products used in potable water systems and describe how the certification process relies on the health effects criteria and toxicological evaluation procedures described in NSF/ANSI/CAN 600.

19.
Cell Rep ; 42(4): 112345, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37027300

RESUMO

The AAA+ NSF complex is responsible for SNARE complex disassembly both before and after membrane fusion. Loss of NSF function results in pronounced developmental and degenerative defects. In a genetic screen for sensory deficits in zebrafish, we identified a mutation in nsf, I209N, that impairs hearing and balance in a dosage-dependent manner without accompanying defects in motility, myelination, and innervation. In vitro experiments demonstrate that while the I209N NSF protein recognizes SNARE complexes, the effects on disassembly are dependent upon the type of SNARE complex and I209N concentration. Higher levels of I209N protein produce a modest decrease in binary (syntaxin-SNAP-25) SNARE complex disassembly and residual ternary (syntaxin-1A-SNAP-25-synaptobrevin-2) disassembly, whereas at lower concentrations binary disassembly activity is strongly reduced and ternary disassembly activity is absent. Our study suggests that the differential effect on disassembly of SNARE complexes leads to selective effects on NSF-mediated membrane trafficking and auditory/vestibular function.


Assuntos
Fusão de Membrana , Proteínas SNARE , Animais , Proteínas SNARE/genética , Proteínas SNARE/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida/genética , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida/metabolismo , Proteínas Sensíveis a N-Etilmaleimida/metabolismo , Mutação/genética , Controle de Qualidade
20.
Acta Pharm Sin B ; 13(3): 1326-1336, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36970201

RESUMO

Neuropathic pain is a chronic disease that severely afflicts the life and emotional status of patients, but currently available treatments are often ineffective. Novel therapeutic targets for the alleviation of neuropathic pain are urgently needed. Rhodojaponin VI, a grayanotoxin from Rhododendron molle, showed remarkable antinociceptive efficacy in models of neuropathic pain, but its biotargets and mechanisms are unknown. Given the reversible action of rhodojaponin VI and the narrow range over which its structure can be modified, we perforwmed thermal proteome profiling of the rat dorsal root ganglion to determine the protein target of rhodojaponin VI. N-Ethylmaleimide-sensitive fusion (NSF) was confirmed as the key target of rhodojaponin VI through biological and biophysical experiments. Functional validation showed for the first time that NSF facilitated trafficking of the Cav2.2 channel to induce an increase in Ca2+ current intensity, whereas rhodojaponin VI reversed the effects of NSF. In conclusion, rhodojaponin VI represents a unique class of analgesic natural products targeting Cav2.2 channels via NSF.

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