dACC

dACC
  • 文章类型: Journal Article
    神经性厌食症(AN)是一种精神和行为健康状况,其特征是对体重或脂肪增加的强烈恐惧,严重限制食物摄入导致低体重,和扭曲的身体形状或体重的自我感知。虽然大量研究集中在AN的一般焦虑上,人们对与饮食相关的焦虑及其潜在的神经机制知之甚少。因此,我们试图在AN中描述“进食焦虑”,并检查背侧前扣带皮质(dACC)内的神经代谢谱,假定参与放大威胁反应的大脑区域。
    寻求AN住院治疗的妇女和体重健康而没有饮食失调史的妇女(健康对照;HC)完成了一项基于计算机的行为任务,评估“进食焦虑””以响应较高(HED)和较低(LED)能量密度食物的图像。参与者还在3T扫描仪中进行了dACC的磁共振波谱检查。
    与HC组相比,AN组报告对食用HED和LED食物的焦虑程度更高。两组报告说,相对于LED食品,他们对吃HED食品的焦虑程度更高。相对于HC,AN中dACC中的神经代谢物肌醇(mI)较低,和MI水平负向预测焦虑吃HED而不是LED食物仅在AN组中。dACC中的MI水平与体重无关,体重,和一般的焦虑。
    这些发现为饮食相关焦虑的临床挑战性特征和潜在神经机制提供了重要的新见解。并表明dACC中的mI水平可以作为疾病严重程度的新生物标志物,该生物标志物与体重无关,以识别易出现饮食紊乱或饮食病理的个体以及潜在的治疗靶标。
    UNASSIGNED: Anorexia nervosa (AN) is a mental and behavioral health condition characterized by an intense fear of weight or fat gain, severe restriction of food intake resulting in low body weight, and distorted self-perception of body shape or weight. While substantial research has focused on general anxiety in AN, less is known about eating-related anxiety and its underlying neural mechanisms. Therefore, we sought to characterize anxiety-to-eat in AN and examine the neurometabolic profile within the dorsal anterior cingulate cortex (dACC), a brain region putatively involved in magnifying the threat response.
    UNASSIGNED: Women seeking inpatient treatment for AN and women of healthy weight without a lifetime history of an eating disorder (healthy controls; HC) completed a computer-based behavioral task assessing anxiety-to-eat in response to images of higher (HED) and lower (LED) energy density foods. Participants also underwent magnetic resonance spectroscopy of the dACC in a 3 Tesla scanner.
    UNASSIGNED: The AN group reported greater anxiety to eat HED and LED foods relative to the HC group. Both groups reported greater anxiety to eat HED foods relative to LED foods. The neurometabolite myo-inositol (mI) was lower in the dACC in AN relative to HC, and mI levels negatively predicted anxiety to eat HED but not LED foods in the AN group only. mI levels in the dACC were independent of body weight, body mass, and general anxiety.
    UNASSIGNED: These findings provide critical new insight into the clinically challenging feature and underlying neural mechanisms of eating-related anxiety and indicate mI levels in the dACC could serve as a novel biomarker of illness severity that is independent of body weight to identify individuals vulnerable to disordered eating or eating pathology as well as a potential therapeutic target.
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  • 文章类型: Journal Article
    自主神经系统(ANS)调节身体的生理机能,包括心血管功能.随着ANS在第二到第三三个月的发展,胎儿心率变异性(HRV)增加,而胎儿心率(HR)降低。这样,胎儿HR和HRV提供了胎儿自主神经系统发育和未来神经行为调节的指标。胎儿HR和HRV与幼儿语言能力和心理运动发育行为有关。然而,它们与出生后自主神经大脑系统的联系,比如脑干,下丘脑,和背侧前扣带皮质(dACC),尽管参与自主神经调节的大脑通路在老年人中已经建立,但仍有待研究。我们评估胎儿HR和HRV是否与脑干相关,新生儿下丘脑和dACC功能连接。数据来自60名妊娠24-27和34-37周的孕妇(年龄14-42岁),使用胎儿心电描记器生成胎儿HR和HRV。在自然睡眠中,他们的婴儿(38名男性和22名女性)在月经后40-46周接受了fMRI扫描.我们的发现将胎儿心脏指数与脑干联系起来,下丘脑,和dACC连通性,并揭示与可能支持行为和情绪调节的广泛大脑区域的联系。我们证明了胎儿HR指数与参与调节过程的低级和高级大脑区域之间的基本生理关联。这项工作为未来胎儿和婴儿的行为或生理调节研究奠定了基础。重要性陈述胎儿心率指数是可量化的,胎儿自主神经系统的发育标志物。它们的轨迹变化可以表明神经发育结果受损。我们评估了胎儿心率指数与婴儿早期大脑发育之间的关联,以确定与自主神经系统成熟模式相对应的独特或常见关联。我们发现胎儿心率指数和婴儿脑干之间有关联,下丘脑,和dACC连接-支持自主和行为调节功能的区域。该研究表明,ANS与参与自主神经调节的大脑区域之间的这些关联存在于生命早期。这些发现是理解这些大脑连接如何构成未来调控发展基础的第一步。
    The autonomic nervous system (ANS) regulates the body\'s physiology, including cardiovascular function. As the ANS develops during the second to third trimester, fetal heart rate variability (HRV) increases while fetal heart rate (HR) decreases. In this way, fetal HR and HRV provide an index of fetal ANS development and future neurobehavioral regulation. Fetal HR and HRV have been associated with child language ability and psychomotor development behavior in toddlerhood. However, their associations with postbirth autonomic brain systems, such as the brainstem, hypothalamus, and dorsal anterior cingulate cortex (dACC), have yet to be investigated even though brain pathways involved in autonomic regulation are well established in older individuals. We assessed whether fetal HR and HRV were associated with the brainstem, hypothalamic, and dACC functional connectivity in newborns. Data were obtained from 60 pregnant individuals (ages 14-42) at 24-27 and 34-37 weeks of gestation using a fetal actocardiograph to generate fetal HR and HRV. During natural sleep, their infants (38 males and 22 females) underwent a fMRI scan between 40 and 46 weeks of postmenstrual age. Our findings relate fetal heart indices to brainstem, hypothalamic, and dACC connectivity and reveal connections with widespread brain regions that may support behavioral and emotional regulation. We demonstrated the basic physiologic association between fetal HR indices and lower- and higher-order brain regions involved in regulatory processes. This work provides the foundation for future behavioral or physiological regulation research in fetuses and infants.
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  • 文章类型: Journal Article
    背景:强迫症患者表现出持续的回避行为,通常是在没有实际威胁的情况下。生活质量成本和异质性支持对新型脑行为干预目标的需求。通过对啮齿动物和非人灵长类动物的持续回避的机械和解剖学研究,我们的目标是测试假设的持续回避相关网络中的连接是否预测OCD相关伤害回避(HA),持续回避的特质度量。我们假设1)HA,不是强迫症诊断,将与网络中至少一个连接中的内源性连通性改变相关;2)HA特异性发现将对合并症症状具有鲁棒性;3)可靠的发现将在保留测试子样本中复制。
    方法:使用静息状态功能连接磁共振成像,用于特征选择的交叉验证弹性网,和泊松广义线性模型,我们在训练子样本(n=73;71.8%为女性;健康对照组n=36,强迫症组n=37);对合并症的稳健性;以及测试子样本中的可复制性(n=30;56.7%为女性;健康对照组n=15,强迫症组n=15)中测试了哪些联系显著预测了HA.
    结果:在各组中,右背前扣带回皮质和右基底外侧杏仁核之间更强的反向连接和右腹前岛和左腹侧纹状体之间更强的正连接与更高的HA相关。网络连接没有区分OCD诊断状态或预测HA相关特征,表明对性状HA的敏感性。背侧前扣带回皮质-基底外侧杏仁核的关系对于控制强迫症患者的合并症和药物治疗是稳健的,并且在我们的测试子样本中也可以预测HA。
    结论:强迫症患者的背背前扣带回皮质-基底外侧杏仁核连接强健可靠地与HA相关。结果支持跨物种持续回避相关网络与强迫症的相关性,对基于精度的方法和治疗有影响。
    BACKGROUND: Individuals with obsessive-compulsive disorder (OCD) show persistent avoidance behaviors, often in the absence of actual threat. Quality-of-life costs and heterogeneity support the need for novel brain-behavior intervention targets. Informed by mechanistic and anatomical studies of persistent avoidance in rodents and nonhuman primates, our goal was to test whether connections within a hypothesized persistent avoidance-related network predicted OCD-related harm avoidance (HA), a trait measure of persistent avoidance. We hypothesized that 1) HA, not an OCD diagnosis, would be associated with altered endogenous connectivity in at least one connection in the network; 2) HA-specific findings would be robust to comorbid symptoms; and 3) reliable findings would replicate in a holdout testing subsample.
    METHODS: Using resting-state functional connectivity magnetic resonance imaging, cross-validated elastic net for feature selection, and Poisson generalized linear models, we tested which connections significantly predicted HA in our training subsample (n = 73; 71.8% female; healthy control group n = 36, OCD group n = 37); robustness to comorbidities; and replicability in a testing subsample (n = 30; 56.7% female; healthy control group n = 15, OCD group n = 15).
    RESULTS: Stronger inverse connectivity between the right dorsal anterior cingulate cortex and right basolateral amygdala and stronger positive connectivity between the right ventral anterior insula and left ventral striatum were associated with greater HA across groups. Network connections did not discriminate OCD diagnostic status or predict HA-correlated traits, suggesting sensitivity to trait HA. The dorsal anterior cingulate cortex-basolateral amygdala relationship was robust to controlling for comorbidities and medication in individuals with OCD and was also predictive of HA in our testing subsample.
    CONCLUSIONS: Stronger inverse dorsal anterior cingulate cortex-basolateral amygdala connectivity was robustly and reliably associated with HA across groups and in OCD. Results support the relevance of a cross-species persistent avoidance-related network to OCD, with implications for precision-based approaches and treatment.
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  • 文章类型: Journal Article
    识别高度遮挡的物体被认为是由大脑的视觉和认知控制区域之间的相互作用引起的,虽然目前支持的神经影像学数据有限。为了探索这种活动的神经机制,我们使用功能磁共振成像(fMRI)进行了遮挡物体识别实验。在磁共振检查期间,66名受试者从事三种不同遮挡程度的物体识别任务。广义线性模型(GLM)分析表明,枕叶(枕下回,枕中回,和枕骨梭形回)和背侧前扣带回皮质(dACC)与物体的咬合程度有关。当将dACC激活作为特征时,多变量模式分析(MVPA)进一步发现了分类精度的显着提高。这表明dACC和枕叶在遮挡物体识别任务中的联合作用。此外,心理生理相互作用(PPI)分析显示,dACC和枕叶之间的功能连接(FC)随着闭塞的增加而增强,强调这两个大脑区域之间FC的必要性,以有效地识别过度闭塞的物体。总之,这些发现有助于理解高度遮挡物体识别的神经机制,增强我们对大脑如何管理不完整的视觉数据的认识。
    Recognizing highly occluded objects is believed to arise from the interaction between the brain\'s vision and cognition-controlling areas, although supporting neuroimaging data are currently limited. To explore the neural mechanism during this activity, we conducted an occlusion object recognition experiment using functional magnetic resonance imaging (fMRI). During magnet resonance examinations, 66 subjects engaged in object recognition tasks with three different occlusion degrees. Generalized linear model (GLM) analysis showed that the activation degree of the occipital lobe (inferior occipital gyrus, middle occipital gyrus, and occipital fusiform gyrus) and dorsal anterior cingulate cortex (dACC) was related to the occlusion degree of the objects. Multivariate pattern analysis (MVPA) further unearthed a considerable surge in classification precision when dACC activation was incorporated as a feature. This suggested the combined role of dACC and the occipital lobe in occluded object recognition tasks. Moreover, psychophysiological interaction (PPI) analysis disclosed that functional connectivity (FC) between the dACC and the occipital lobe was enhanced with increased occlusion, highlighting the necessity of FC between these two brain regions in effectively identifying exceedingly occluded objects. In conclusion, these findings contribute to understanding the neural mechanisms of highly occluded object recognition, augmenting our appreciation of how the brain manages incomplete visual data.
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  • 文章类型: Journal Article
    为了更新有关在预防中使用二烷基氨基甲酰氯(DACC)涂层伤口敷料的证据,伤口的治疗和管理。
    搜索PubMed和PubMedCentral数据库,以确定自2020年以来发表的描述DACC涂层敷料的实验和临床证据的文章,以及它们的抗菌作用,以及它们对感染伤口的预防和治疗的影响。然后对确定的文章进行叙述性审查。
    搜索产生了113篇文章(加上来自临时来源的参考文献),其中9人符合纳入标准。在九项纳入的研究中,5项与临床相关,4项为实验室研究.
    许多新研究为DACC涂层敷料的抗菌作用及其广谱效应(包括世界卫生组织优先考虑的微生物)的作用方式提供了进一步的证据。其他临床研究提供了新应用的证据,例如在治疗儿科患者的伤口时,并扩展了有关其用于治疗手术部位感染的证据。证据还表明,DACC涂层的伤口敷料可以帮助结合生物膜,以及这项技术如何在预防抗菌素耐药性方面协调和支持抗菌素管理。
    UNASSIGNED: To update the evidence in relation to the use of dialkylcarbamoyl chloride (DACC)-coated wound dressings in the prevention, treatment and management of wounds.
    UNASSIGNED: PubMed and PubMed Central databases were searched to identify articles published since 2020 describing the experimental and clinical evidence for DACC-coated dressings, and their antimicrobial effect, as well as their impact on the prevention and treatment of infected wounds. The identified articles were then narratively reviewed.
    UNASSIGNED: The search yielded 113 articles (plus references from ad hoc sources), of which nine met the inclusion criteria. Of the nine included studies, five related to clinical aspects and four were laboratory studies.
    UNASSIGNED: A number of new studies have provided further evidence for the mode of action of the antimicrobial effect of DACC-coated dressings and its wide spectrum effect (including World Health Organization-prioritised microorganisms). Additional clinical studies have provided evidence of new applications, such as in treating wounds in paediatric patients, and extended the evidence relating to their use in treating surgical site infections. Evidence also shows that DACC-coated wound dressings can aid in the binding of biofilms, and how this technology can align and support antimicrobial stewardship in the prevention of antimicrobial resistance.
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  • 文章类型: Review
    背侧前额叶皮质/背侧前扣带皮质(dmPFC/dACC)是受许多理论和关于其功能的辩论的大脑区域。甚至其精确的解剖边界也受到很多争议。在过去的几十年里,dmPFC/dACC与超过15种不同的认知过程相关,有时看起来很不相关(例如,身体感知,认知冲突)。因此,了解dmPFC/dACC的作用已成为许多神经科学家的真正挑战。已经发展了几种关于这个大脑区域功能的理论,导致连续和有竞争力的出版物承载不同的模式,有时彼此矛盾。在过去的二十年里,围绕dmPFC/dACC的活跃科学交流促进了认知神经科学的卓有成效的研究。在这次审查中,我们概述了dmPFC/dACC的解剖结构,总结与这个大脑区域相关的最新功能,并介绍了用于解释dmPFC/dACC功能的主要理论。我们探讨了不同理论之间的共同点和争论。最后,我们解释了从这些辩论中可以学到什么,以便将来研究dmPFC/dACC和其他大脑区域的功能。
    The dorsomedial prefrontal cortex/dorsal anterior cingulate cortex (dmPFC/dACC) is a brain area subject to many theories and debates over its function(s). Even its precise anatomical borders are subject to much controversy. In the past decades, the dmPFC/dACC has been associated with more than 15 different cognitive processes, which sometimes appear quite unrelated (e.g. body perception, cognitive conflict). As a result, understanding what the dmPFC/dACC does has become a real challenge for many neuroscientists. Several theories of this brain area\'s function(s) have been developed, leading to successive and competitive publications bearing different models, which sometimes contradict each other. During the last two decades, the lively scientific exchanges around the dmPFC/dACC have promoted fruitful research in cognitive neuroscience. In this review, we provide an overview of the anatomy of the dmPFC/dACC, summarize the state of the art of functions that have been associated with this brain area and present the main theories aiming at explaining the dmPFC/dACC function(s). We explore the commonalities and the arguments between the different theories. Finally, we explain what can be learned from these debates for future investigations of the dmPFC/dACC and other brain regions\' functions.
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  • 文章类型: Meta-Analysis
    自我调节,这是个人控制情绪和行为以追求目标的能力,是一种依赖于分布式大脑网络的复杂认知功能。这里,我们使用激活似然估计(ALE)对情绪调节和行为调节的脑成像研究进行了两项大规模荟萃分析.我们使用ALE的单一分析来识别与行为调节和情绪调节相关的大脑激活区域。两个域的对比分析的结合结果表明,背前扣带皮质(dACC)的关键脑区,双侧前岛(AI),右下顶叶小叶(IPL)在空间和功能水平上嵌套在两个调节域的大脑区域内。此外,我们使用meta分析连接模型(MACM)评估了4个常见区域的共激活模式.基于dACC和双侧AI的共激活大脑模式与两个调节大脑图重叠比例很高。此外,使用BrainMap数据库对确定的共同区域的功能特征进行反向推断.总的来说,这些结果表明,dACC和双侧AI的大脑区域,通过自我调节的有效连接,作为其他大脑区域和网络的枢纽,发挥关键作用,在空间上嵌套在行为调节和情绪调节的大脑网络中。
    Self-regulation, which is an individual\'s ability to control their emotions and behaviors in pursuit of goals, is a complex cognitive function that relies on distributed brain networks. Here, we used activation likelihood estimation (ALE) to conduct two large-scale meta-analyses of brain imaging studies of emotional regulation and behavioral regulation. We used single analysis of ALE to identify brain activation regions associated with behavioral regulation and emotion regulation. The conjunction results of the contrast analysis of the two domains showed that the crucial brain regions of dorsal anterior cingulate cortex (dACC), bilateral anterior insula (AI), and right inferior parietal lobule (IPL) are nested within the brain areas of the two regulation domains at the spatial and functional level. In addition, we assessed the coactivation pattern of the four common regions using meta-analytic connectivity modeling (MACM). The coactivation brain patterns based on the dACC and bilateral AI overlapped with the two regulation brain maps in a high proportion. Furthermore, the functional characters of the identified common regions were reverse-inferenced using the BrainMap database. Collectively, these results indicate that the brain regions of dACC and bilateral AI, playing a crucial role as a hub to other brain regions and networks by effective connectivity in self-regulation, are spatially nested in the brain network of behavioral regulation and emotion regulation.
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  • 文章类型: Journal Article
    背景:对于创伤后应激障碍来说,情境依赖性调节条件性恐惧的困难是已知的,并且可以解释在安全情境下侵入性记忆的发生。因此,当前的研究调查了条件性恐惧的上下文依赖性调节及其潜在的神经回路是否构成了响应实验性创伤而发展模拟侵入的危险因素。
    方法:八十五名健康女性参与了创伤电影范式,以调查模拟侵入的发展以及对一周和三个月后实验性创伤的外显记忆,分别。之前,参与者在功能磁共振成像期间接受了依赖于上下文的恐惧条件范式,第一天在上下文A中获得恐惧,在上下文B中进行灭绝训练,以及一天后在上下文B中的灭绝回忆和在小说上下文C中的恐惧更新。皮肤电导反应(SCR)和血氧水平依赖性反应是主要的结局指标。
    结果:除了在上下文A中获得更强的恐惧之外,在安全的情况下,有更强的条件性恐惧反应,如在灭绝学习和回忆期间更强的条件SCR或更强的恐惧表达区域激活所示,预测了长期模拟入侵的发展。
    结论:在安全和危险环境中,更强的恐惧反应是长期模拟入侵发展的危险因素,并指出去语境化恐惧记忆和条件恐惧依赖调节中的困难。恐惧调节过程的改变和上下文信息存储的减少可能导致独立于上下文的恐惧的发生。
    BACKGROUND: Difficulties in the context-dependent modulation of conditioned fear are known for posttraumatic stress disorder and may explain the occurrence of intrusive memories in safe contexts. The current study therefore investigated if reduced context-dependent modulation of conditioned fear and its underlying neural circuitry constitute risk factors for the development of analog intrusions in response to an experimental trauma.
    METHODS: Eighty-five healthy women participated in the trauma film paradigm to investigate the development of analog intrusions as well as explicit memory for an experimental trauma after one week and three months, respectively. Before, participants underwent a context-dependent fear conditioning paradigm during functional magnetic resonance imaging with fear acquisition in context A and extinction training in context B on a first day, as well as extinction recall in context B and fear renewal in a novel context C one day later. Skin conductance responses (SCRs) and blood oxygen level dependent responses were main outcome measures.
    RESULTS: In addition to stronger fear acquisition in context A, stronger conditioned fear responses in the safe context B, as indicated by stronger conditioned SCRs or stronger activation of fear expressing regions during extinction learning and recall, predicted the development of long-term analog intrusions.
    CONCLUSIONS: Stronger fear responses in safe and danger contexts were risk factors for the development of long-term analog intrusions and point to decontextualized fear memories and difficulties in the context-dependent modulation of conditioned fear. Altered fear conditioning processes and reduced storage of contextual information may cause the occurrence of fear independent of context.
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  • 文章类型: Journal Article
    肽聚糖(PG)是一种重要的细菌结构,对于维持形状和适应渗透胁迫至关重要。尽管PG的合成和改性在恶劣的环境压力下受到严格的调控,相关机制很少被研究。在这项研究中,我们旨在研究PGdd-羧肽酶(DD-CPases)DacC和DacA在碱性和盐胁迫下的细胞生长以及大肠杆菌的形状维持中的协调和不同作用。我们发现DacC是一种碱性DD-CPase,在碱性胁迫下酶活性和蛋白质稳定性显著增强。DacC和DacA都是碱性胁迫下细菌生长所必需的,而在盐胁迫下生长只需要DacA。在正常生长条件下,只有DacA是细胞形状维持所必需的,在碱性胁迫条件下,DacA和DacC都是细胞形状维持所必需的,但是他们的角色是不同的。值得注意的是,DacC和DacA的所有这些作用都独立于ld-转肽酶,这对于PG与外膜脂蛋白Lpp之间形成PG3-3交联和共价键是必需的。相反,DacC和DacA与青霉素结合蛋白(PBP)-dd-转肽酶相互作用-主要以C末端结构域依赖性方式,这些互动对于他们的大多数角色都是必要的。总的来说,我们的结果证明了DD-CPases在应激条件下细菌生长和形状维持中的协调和独特的新作用,并为与PBPs相关的DD-CPases的细胞功能提供了新的见解.重要性大多数细菌具有肽聚糖结构,用于维持细胞形状和防止渗透挑战。肽聚糖dd-羧肽酶控制五肽底物的量,用于通过肽聚糖合成的dd-转肽酶形成4-3个交联,青霉素结合蛋白(PBP)。大肠杆菌中存在7种dd-羧肽酶,但是对它们冗余的生理意义以及它们在肽聚糖合成中的作用却知之甚少。这里,我们表明,DacC是一种碱性dd-羧肽酶,其蛋白质稳定性和酶活性在高pH下均显着增强。引人注目的是,dd-羧肽酶DacC和DacA与PBP物理相互作用,这些相互作用对于细胞形状的维持以及在碱性和盐胁迫下的生长是必需的。因此,dd-羧肽酶和PBP之间的合作可以允许大肠杆菌克服各种应激并维持细胞形状。
    Peptidoglycan (PG) is an essential bacterial architecture pivotal for shape maintenance and adaptation to osmotic stress. Although PG synthesis and modification are tightly regulated under harsh environmental stresses, few related mechanisms have been investigated. In this study, we aimed to investigate the coordinated and distinct roles of the PG dd-carboxypeptidases (DD-CPases) DacC and DacA in cell growth under alkaline and salt stresses and shape maintenance in Escherichia coli. We found that DacC is an alkaline DD-CPase, the enzyme activity and protein stability of which are significantly enhanced under alkaline stress. Both DacC and DacA were required for bacterial growth under alkaline stress, whereas only DacA was required for growth under salt stress. Under normal growth conditions, only DacA was necessary for cell shape maintenance, while under alkaline stress conditions, both DacA and DacC were necessary for cell shape maintenance, but their roles were distinct. Notably, all of these roles of DacC and DacA were independent of ld-transpeptidases, which are necessary for the formation of PG 3-3 cross-links and covalent bonds between PG and the outer membrane lipoprotein Lpp. Instead, DacC and DacA interacted with penicillin-binding proteins (PBPs)-dd-transpeptidases-mostly in a C-terminal domain-dependent manner, and these interactions were necessary for most of their roles. Collectively, our results demonstrate the coordinated and distinct novel roles of DD-CPases in bacterial growth and shape maintenance under stress conditions and provide novel insights into the cellular functions of DD-CPases associated with PBPs. IMPORTANCE Most bacteria have a peptidoglycan architecture for cell shape maintenance and protection against osmotic challenges. Peptidoglycan dd-carboxypeptidases control the amount of pentapeptide substrates, which are used in the formation of 4-3 cross-links by the peptidoglycan synthetic dd-transpeptidases, penicillin-binding proteins (PBPs). Seven dd-carboxypeptidases exist in Escherichia coli, but the physiological significance of their redundancy and their roles in peptidoglycan synthesis are poorly understood. Here, we showed that DacC is an alkaline dd-carboxypeptidase for which both protein stability and enzyme activity are significantly enhanced at high pH. Strikingly, dd-carboxypeptidases DacC and DacA physically interacted with PBPs, and these interactions were necessary for cell shape maintenance as well as growth under alkaline and salt stresses. Thus, cooperation between dd-carboxypeptidases and PBPs may allow E. coli to overcome various stresses and to maintain cell shape.
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  • 文章类型: Journal Article
    未经授权:布鲁里溃疡(BU)可导致溃疡和永久性残疾。2030年世界卫生组织(WHO)被忽视的热带病(NTD)路线图呼吁大规模扩大诊断和管理,以消除因疾病而导致的残疾。目前BU的治疗是每天口服利福平(10mg/kg剂量)和克拉霉素(15mg/kg剂量),持续八周,结合标准纱布伤口敷料。已显示二烷基氨基甲酰氯(DACC)涂覆的敷料不可逆地结合伤口表面上的细菌,导致当更换敷料时它们被去除。该试验旨在确定相对于标准剂量口服利福平联合DACC敷料,高剂量口服利福平方案联合DACC敷料是否可以提高伤口愈合率。
    未经授权:这是个人,多中心3期随机对照试验,这将在加纳的三个临床地点进行。主要结果测量将是清除活分枝杆菌的平均时间。将收集成本和健康相关的生活质量数据,并进行成本效益分析。
    UNASSIGNED:这项试验的结果可能导致BU治疗方式的改变。更短但更有效的治疗方案将导致改善的治疗结果和潜在的大量财政和经济储蓄。
    UNASSIGNED: Buruli ulcer (BU) can lead to disfiguring ulcers and permanent disability. The 2030 World Health Organization (WHO) road map for Neglected Tropical Diseases (NTDs) calls for major scaling up in diagnosis and management to eliminate disability due to the disease. Current treatment for BU is with daily oral rifampicin (10mg/kg dose) and clarithromycin (15mg/kg dose) for eight weeks, combined with standard gauze wound dressings. Dialkylcarbamoyl chloride (DACC)-coated dressings have been shown to irreversibly bind bacteria on wound surfaces resulting in their removal when dressings are changed. This trial aims to determine whether combining a high-dose oral rifampicin regimen with DACC dressings can improve the rate of wound healing relative to standard-dose oral rifampicin combined with DACC dressings.
    UNASSIGNED: This is an individual, multi-centre Phase 3 randomised controlled trial, which will be conducted in three clinical sites in Ghana. The primary outcome measure will be the mean time to clearance of viable mycobacteria. Cost and health-related quality of life data will be collected, and a cost-effectiveness analysis will be performed.
    UNASSIGNED: The findings from this trial could lead to a change in how BU is treated. A shorter but more efficacious regimen would lead to improved treatment outcomes and potentially substantial financial and economic savings.
    UNASSIGNED: Pan African Clinical Trials Repository (registration number; PACTR202011867644311). Registered on 30 th November 2020.
    Buruli ulcer (BU), caused by Mycobacterium ulcerans, manifests clinically as a wound or swelling. There are several approaches for managing this condition. One is the availability of two antibiotics, usually rifampicin in combination with clarithromycin, that can be used to treat the disease. Rifampicin is thought to be the most important of these two drugs. Scientists have found out that a higher dose of rifampicin is safe and may help improve healing outcome and shorten the duration of treatment. Individuals with BU wounds also go through wound dressing procedures at their hospitals and health centres. Commonly, wounds are dressed using Vaseline gauze and bandages. However, it has been observed that some affected individuals heal faster than others even with the antibiotic treatment. Some still have living organisms in their wounds many weeks after the antibiotic treatment. There is a new dressing material called DACC which is believed to permanently bind bacteria on the wound surface leading to their removal when the dressings are changed. This may be a good way to treat and prevent infection without the use of more drugs. This study aims to determine whether combining a high-dose oral rifampicin regimen with DACC dressings can improve the rate of wound healing relative to standard-dose oral rifampicin combined with DACC dressings. Furthermore, cost and health-related quality of life data will be collected and a cost-effectiveness analysis will be performed. The findings from this trial could lead to a change in how BU is treated. A shorter but more efficacious regimen would lead to improved treatment outcomes and potentially substantial financial and economic savings.
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