Uncovering a mammalian neural-specific poly(A) binding protein with unique properties.

The mRNA 3' poly(A) tail plays a critical role in regulating both mRNA translation and turnover. It is bound by the cytoplasmic poly(A) binding protein (PABPC), an evolutionarily conserved protein that can interact with translation factors and mRNA decay machineries to regulate gene expression. Mammalian PABPC1, the prototypical PABPC, is expressed in most tissues and interacts with eukaryotic translation initiation factor 4G (eIF4G) to stimulate translation in specific contexts. In this study, we uncovered a new mammalian PABPC, which we named neural PABP (neuPABP), as it is predominantly expressed in the brain. neuPABP maintains a unique architecture as compared with other PABPCs, containing only two RNA recognition motifs (RRMs) and maintaining a unique N-terminal domain of unknown function. neuPABP expression is activated in neurons as they mature during synaptogenesis, where neuPABP localizes to the soma and postsynaptic densities. neuPABP interacts with the noncoding RNA BC1, as well as mRNAs coding for ribosomal and mitochondrial proteins. However, in contrast to PABPC1, neuPABP does not associate with actively translating mRNAs in the brain. In keeping with this, we show that neuPABP has evolved such that it does not bind eIF4G and as a result fails to support protein synthesis in vitro. Taken together, these results indicate that mammals have expanded their PABPC repertoire in the brain and propose that neuPABP may support the translational repression of select mRNAs.

PABP prevents the untimely decay of select mRNA populations in human cells.

Gene expression is tightly regulated at the levels of both mRNA translation and stability. The poly(A)-binding protein (PABP) is thought to play a role in regulating these processes by binding the mRNA 3' poly(A) tail and interacting with both the translation and mRNA deadenylation machineries. In this study, we directly investigate the impact of PABP on translation and stability of endogenous mRNAs in human cells. Remarkably, our transcriptome-wide analysis only detects marginal mRNA translation changes in PABP-depleted cells. In contrast, rapidly depleting PABP alters mRNA abundance and stability, albeit non-uniformly. Otherwise stable transcripts, including those encoding proteins with constitutive functions, are destabilized in PABP-depleted cells. In contrast, many unstable mRNAs, including those encoding proteins with regulatory functions, decay at similar rates in presence or absence of PABP. Moreover, PABP depletion-induced cell death can partially be suppressed by disrupting the mRNA decapping and 5'-3' decay machinery. Finally, we provide evidence that the LSM1-7 complex promotes decay of "stable" mRNAs in PABP-depleted cells. Taken together, these findings suggest that PABP plays an important role in preventing the untimely decay of select mRNA populations.

Fragility of Statistically Significant Outcomes in Colonic Diverticular Disease Randomized Trials: A Systematic Review.

BACKGROUND: The p value has been criticized as an oversimplified determination of whether a treatment effect exists. One alternative is the fragility index. It is a representation of the minimum number of nonevents that would need to be converted to events to increase the p value above 0.05. OBJECTIVE: To determine the fragility index of randomized controlled trials assessing the efficacy of interventions for patients with diverticular disease since 2010 to assess the robustness of current evidence. DESIGN: MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to August 2022. SETTINGS: Articles were eligible for inclusion if they were randomized trials conducted between 2010 and 2022 with parallel, superiority designs evaluating interventions in patients with diverticular disease. Only randomized trials with dichotomous primary outcomes with an associated p value of <0.05 were considered for inclusion. PARTICIPANTS: Any surgical or medical intervention for patients with diverticular disease. MAIN OUTCOME MEASURES: The fragility index was determined by adding events and subtracting nonevents from the groups with the smaller number of events. Events were added until the p value exceeded 0.05. The smallest number of events required was considered the fragility index. RESULTS: After screening 1271 citations, 15 randomized trials met the inclusion criteria. Nine of the studies evaluated surgical interventions and 6 evaluated medical interventions. The mean number of patients randomly assigned and lost to follow-up per randomized controlled trial was 92 (SD 35.3) and 9 (SD 11.4), respectively. The median fragility index was 1 (range, 0-5). The fragility indices for the included studies did not correlate significantly with any study characteristics. LIMITATIONS: Small sample, heterogeneity, and lack of inclusion of studies with continuous outcomes. CONCLUSIONS: The randomized trials evaluating surgical and medical interventions for diverticular disease are not robust. Changing a single-outcome event in most studies was sufficient to make a statistically significant study finding not significant. See Video Abstract . FRAGILIDAD DE LOS RESULTADOS ESTADSTICAMENTE SIGNIFICATIVOS EN ENSAYOS ALEATORIOS DE ENFERMEDAD DIVERTICULAR DEL COLON UNA REVISIN SISTEMTICA: ANTECEDENTES:El valor p ha sido criticado por una determinación demasiado simplificada de si existe un efecto del tratamiento. Una alternativa es el Índice de Fragilidad. Es una representación del número mínimo de no eventos que deberían convertirse en eventos para aumentar el valor p por encima de 0,05.OBJETIVO:Determinar el IF de ensayos controlados aleatorios que evalúan la eficacia de las intervenciones para pacientes con enfermedad diverticular desde 2010 para evaluar la solidez de la evidencia actual.FUENTES DE DATOS:Se realizaron búsquedas en MEDLINE, Embase y CENTRAL desde el inicio hasta agosto de 2022.SELECCIÓN DE ESTUDIOS:Los artículos eran elegibles para su inclusión si eran ensayos aleatorizados realizados entre 2010 y 2022 con diseños paralelos de superioridad que evaluaran intervenciones en pacientes con enfermedad diverticular. Sólo se consideraron para su inclusión los ensayos aleatorizados con resultados primarios dicotómicos con un valor de p asociado menor que 0,05.INTERVENCIÓNES:Cualquier intervención quirúrgica o médica para pacientes con enfermedad diverticular.PRINCIPALES MEDIDAS DE VALORACIÓN:El índice de fragilidad se determinó sumando eventos y restando no eventos de los grupos con el menor número de eventos. Se agregaron eventos hasta que el valor p superó 0,05. El menor número de eventos requeridos se consideró índice de fragilidad.RESULTADOS:Después de examinar 1271 citas, 15 ensayos aleatorios cumplieron los criterios de inclusión. Nueve de los estudios evaluaron intervenciones quirúrgicas y seis evaluaron intervenciones médicas. El número medio de pacientes aleatorizados y perdidos durante el seguimiento por ECA fue 92 (DE 35,3) y 9 (DE 11,4), respectivamente. La mediana del índice de fragilidad fue 1 (rango: 0-5). Los índices de fragilidad de los estudios incluidos no se correlacionaron significativamente con ninguna característica del estudio.LIMITACIONES:Muestra pequeña, heterogeneidad y falta de inclusión de estudios con resultados continuos.CONCLUSIONES:Los ensayos aleatorios que evalúan las intervenciones quirúrgicas y médicas para la enfermedad diverticular no son sólidos. Cambiar un solo evento de resultado en la mayoría de los estudios fue suficiente para que un hallazgo estadísticamente significativo del estudio no fuera significativo. (Traducción- Dr. Ingrid Melo ).

The role of warmed-humidified carbon dioxide insufflation in colorectal surgery: A systematic review and meta-analysis.

BACKGROUND: Maintenance of normothermia is a crucial part of enhanced recovery after colorectal surgery. Dry-cold carbon dioxide (CO2 ) traditionally used for insufflation in laparoscopic surgery and negative pressure operating theatres has been associated with intraoperative hypothermia. Studies suggest that use of warmed-humidified CO2 may promote normothermia. However, due to a scarcity of high-quality studies demonstrating a proven benefit on intraoperative core body temperature, its use in colorectal surgery remains limited. Therefore, the aim of this review was to evaluate the effects of warmed-humidified CO2 compared to traditional dry-cold CO2 , or ambient air in operating theatres, during colorectal surgery. METHODS: A search of Medline, EMBASE, and CENTRAL was performed. Randomised controlled trials (RCTs) that compared patients receiving warmed-humidified CO2 with either dry-cold CO2 insufflation in laparoscopic procedures or no insufflation during open surgery were included. The primary outcome was change in intraoperative core body temperature. Secondary outcomes included length of stay, operating time, return of gastrointestinal function, wound infection, and postoperative pain. A pairwise meta-analysis was performed using inverse variance random effects. RESULTS: Among the six RCTs included, 208 patients received warmed-humidified CO2 (42.3% female, mean age: 65.8 years) and 210 patients received either dry-cold CO2 in laparoscopic procedures or no gas insufflation during open procedures (46.2% female, mean age: 66.1 years). No significant difference was found for change in intraoperative core body temperature (MD = 0.01, 95% CI: -0.1, 0.11, p = 0.90, very low certainty). Patients in the warmed-humidified CO2 group had significantly higher pain scores on postoperative day 1 (MD = 1.61, 95% CI: 0.91, 2.31, p < 0.05, very low certainty). No significant differences were found in any of the other secondary outcomes studied. CONCLUSION: Patients undergoing colorectal surgery receiving warmed-humidified CO2 do not experience any clinically meaningful difference in core body temperature change compared to their counterparts receiving dry-cold CO2 insufflation or no insufflation. However, patients may report greater pain scores on postoperative day 1 with warmed-humidified CO2 . There is likely no clinically important difference between warmed-humidified CO2 and dry-cold CO2 for patients undergoing colorectal surgery. Patient, clinician, and institution factors should be considered when deciding between these two insufflation modalities.

Frailty in inflammatory bowel disease: analysis of the National Inpatient Sample 2015-2019.

AIM: Preoperative frailty has been associated with adverse postoperative outcomes in various populations, but of its use in patients with inflammatory bowel disease (IBD) remains sparse. The present study aimed to characterize the impact of frailty, as measured by the modified frailty index (mFI), on postoperative clinical and resource utilization outcomes in patients with IBD. METHODS: This retrospective population-based cohort study assessed patients from the National Inpatient Sample database from 1 September 2015 to 31 December 2019. Corresponding International Classification of Diseases 10th Revision Clinical Modification codes were used to identify adult patients (>18 years of age) with IBD, undergoing either small bowel resection, colectomy or proctectomy. Patient demographics and institutional data were collected for each patient to calculate the 11-point mFI. Patients were categorized as either frail or robust using a cut-off of 0.27. Primary outcomes were postoperative in-hospital morbidity and mortality, whilst secondary outcomes included system-specific morbidity, length of stay, in-hospital healthcare costs and discharge disposition. Logistic and linear regression models were used for primary and secondary outcomes. RESULTS: Overall, 7144 patients with IBD undergoing small bowel resection, colectomy or proctectomy were identified, 337 of whom were classified as frail (i.e., mFI < 0.27). Frail patients were more likely to be women, older, have lower income and a greater number of comorbidities. After adjusting for relevant covariates, frail patients were at greater odds of in-hospital mortality (adjusted odds ratio [aOR] 5.42, 95% CI 2.31-12.77, P < 0.001), overall morbidity (aOR 1.72, 95% CI 1.30-2.28, P < 0.001), increased length of stay (adjusted mean difference 1.3 days, 95% CI 0.09-2.50, P = 0.035) and less likely to be discharged to home (aOR 0.59, 95% CI 0.45-0.77, P < 0.001) compared to their robust counterparts. CONCLUSIONS: Frail IBD patients are at greater risk of postoperative mortality and morbidity, and reduced likelihood of discharge to home, following surgery. This has implications for clinicians designing care pathways for IBD patients following surgery.

Acetylation-Dependent Control of Global Poly(A) RNA Degradation by CBP/p300 and HDAC1/2.

Acetylation of histones and transcription-related factors is known to exert epigenetic and transcriptional control of gene expression. Here we report that histone acetyltransferases (HATs) and histone deacetylases (HDACs) also regulate gene expression at the posttranscriptional level by controlling poly(A) RNA stability. Inhibition of HDAC1 and HDAC2 induces massive and widespread degradation of normally stable poly(A) RNA in mammalian and Drosophila cells. Acetylation-induced RNA decay depends on the HATs p300 and CBP, which acetylate the exoribonuclease CAF1a, a catalytic subunit of the CCR4-CAF1-NOT deadenlyase complex and thereby contribute to accelerating poly(A) RNA degradation. Taking adipocyte differentiation as a model, we observe global stabilization of poly(A) RNA during differentiation, concomitant with loss of CBP/p300 expression. Our study uncovers reversible acetylation as a fundamental switch by which HATs and HDACs control the overall turnover of poly(A) RNA.

Utility of Chemical Shift Imaging and Diffusion-weighted Images/Apparent Diffusion Coefficient Maps as a Tool for Evaluation of Solid Renal Tumors.

OBJECTIVES: To study the utility of chemical shift imaging (CSI) and diffusion-weighted images (DWI)/apparent diffusion coefficient (ADC) maps for the evaluation of solid renal tumors. METHODS: Magnetic resonance imaging (MRI) has an equivalent application as computerized tomography (CT) in the characterization of renal masses. It offers a radiation-free imaging technique and has a better soft tissue contrast than CT. Also, MRI is favored in patients with chronic kidney disease. MRI is useful when findings on CT are equivocal. The role of DWI in characterizing solid renal lesions as malignant is encouraging, and DWI can be particularly useful when gadolinium is contraindicated. CSI is useful in differentiating angiomyolipoma (AML) from clear cell (cc) renal cell carcinoma (RCC). We did a cross-sectional study on 24 patients with solid renal masses. MRI of the upper abdomen (from the dome of the diaphragm to the iliac crest) will be done on an MRI machine in our department (1.5T, ACHIEVA, Phillips medical system) using the torso coil. RESULT: There was no significant association seen in terms of ADC values and histological subtypes (χ2 = 11.222, p = 0.082). In our study, 50% (one out of two) of AML showed a signal drop, whereas 40% of cases (6 out of 15) of ccRCC and 66% (two out of three) of papillary RCC showed a signal drop. CONCLUSION: In this article, we concluded CSI, although a useful tool to look for microscopic fat, can't be used as a reliable marker to rule in cc-carcinoma as both AML and papillary cell carcinoma have microscopic fat. Further, no histological classification can be done on the basis of DWI/ADC images.

HEmoRhoidal disease management with Band ligation versus polidocanol Sclerotherapy: a systematic review and meta-analysis (the HerBS Review).

PURPOSE: Symptomatic internal hemorrhoids affect up to 40% of people in Western society. Patients with grade I-III hemorrhoids, who fail lifestyle and medical management, may benefit from office-based procedures. As per the American Society of Colon and Rectum Surgeons (ASCRS), rubber band ligation (RBL) is the first-line office-based treatment. Polidocanol sclerotherapy is a relatively new approach for these patients. The aim of this systematic review is to compare the efficacy of RBL and polidocanol sclerotherapy with the treatment of symptomatic grade I-III internal hemorrhoids. METHODS: The systematic review was completed by searching MEDLINE, Embase, and CENTRAL databases from inception to August 2022 for prospective studies comparing RBL and polidocanol sclerotherapy or evaluating the efficacy of polidocanol sclerotherapy alone for adult (> 18 years) patients with grade I-III internal hemorrhoids. Treatments were evaluated for therapeutic success and post-procedure morbidity. RESULTS: Of 155 citations obtained, 10 studies (3 comparative and 7 single-arm studies) and 4 abstracts (2 comparative and 2 single arm) were included in the study. The patients undergoing sclerotherapy had a 93% (151/163) therapeutic success rate compared to 75% (68/91) in the RBL group (OR 3.39, 95% CI 1.48-7.74, p < 0.01). The post-procedure morbidity was 8% (17/200) in the sclerotherapy group and 18% (23/128) in the RBL group (OR 0.53, 95% CI 0.15-1.82, p = 0.31). CONCLUSION: This study highlights that polidocanol sclerotherapy may be associated with higher therapeutic success in patients with symptomatic grade I-III internal hemorrhoids. Further evaluations in the form of randomized trials are required to evaluate patient populations, which may benefit more from sclerotherapy.

The Rsm (Csr) post-transcriptional regulatory pathway coordinately controls multiple CRISPR-Cas immune systems.

CRISPR-Cas systems provide bacteria with adaptive immunity against phages and plasmids; however, pathways regulating their activity are not well defined. We recently developed a high-throughput genome-wide method (SorTn-seq) and used this to uncover CRISPR-Cas regulators. Here, we demonstrate that the widespread Rsm/Csr pathway regulates the expression of multiple CRISPR-Cas systems in Serratia (type I-E, I-F and III-A). The main pathway component, RsmA (CsrA), is an RNA-binding post-transcriptional regulator of carbon utilisation, virulence and motility. RsmA binds cas mRNAs and suppresses type I and III CRISPR-Cas interference in addition to adaptation by type I systems. Coregulation of CRISPR-Cas and flagella by the Rsm pathway allows modulation of adaptive immunity when changes in receptor availability would alter susceptibility to flagella-tropic phages. Furthermore, we show that Rsm controls CRISPR-Cas in other genera, suggesting conservation of this regulatory strategy. Finally, we identify genes encoding RsmA homologues in phages, which have the potential to manipulate the physiology of host bacteria and might provide an anti-CRISPR activity.

Patient Perceptions of Audio and Video Recording in the Operating Room.

OBJECTIVE: The goal of this study was to determine surgical patients' perceptions of hypothetical continuous audio-video OR recording (ORR). SUMMARY OF BACKGROUND DATA: Continuous audio-video recording of the operating room (OR), akin to the aviation industry's black box, has been proposed as a means to enhance training, supplement the medical record, and allow large-scale analysis of surgical performance and safety. These recordings would include patients' bodies; yet, understanding of patient perceptions regarding such technology is limited. METHODS: Semi-structured interviews were conducted during elective surgery preoperative appointments during a 2-week period in August 2018 at a quaternary care center. Deidentified transcripts were analyzed using thematic analysis. RESULTS: Forty-nine subjects were interviewed. Subjects recognized the potential for recording to improve surgical quality, safety and training. Subjects also desired access to an objective record of their own surgery, for the purposes of future care, medical-legal evidence, and to satisfy their own curiosity and understanding. Subjects had mixed perceptions regarding OR decorum and thus, differing views on the potential effect of ORR on OR behavior; some imagined that ORR would discourage bad behavior and others worried that it would cause unnecessary anxiety to the surgical team. CONCLUSIONS: Patients have a diverse set of views about the potential benefits, risks, and uses for OR data and consider themselves to be important stakeholders. Our study identifies pathways and potential challenges to implementation of continuous audio/video recording in ORs.

The penalty of stress - Epichaperomes negatively reshaping the brain in neurodegenerative disorders.

Adaptation to acute and chronic stress and/or persistent stressors is a subject of wide interest in central nervous system disorders. In this context, stress is an effector of change in organismal homeostasis and the response is generated when the brain perceives a potential threat. Herein, we discuss a nuanced and granular view whereby a wide variety of genotoxic and environmental stressors, including aging, genetic risk factors, environmental exposures, and age- and lifestyle-related changes, act as direct insults to cellular, as opposed to organismal, homeostasis. These two concepts of how stressors impact the central nervous system are not mutually exclusive. We discuss how maladaptive stressor-induced changes in protein connectivity through epichaperomes, disease-associated pathologic scaffolds composed of tightly bound chaperones, co-chaperones, and other factors, impact intracellular protein functionality altering phenotypes, that in turn disrupt and remodel brain networks ranging from intercellular to brain connectome levels. We provide an evidence-based view on how these maladaptive changes ranging from stressor to phenotype provide unique precision medicine opportunities for diagnostic and therapeutic development, especially in the context of neurodegenerative disorders including Alzheimer's disease where treatment options are currently limited.

A conserved motif in human BTG1 and BTG2 proteins mediates interaction with the poly(A) binding protein PABPC1 to stimulate mRNA deadenylation.

Antiproliferative BTG/Tob proteins interact directly with the CAF1 deadenylase subunit of the CCR4-NOT complex. This binding requires the presence of two conserved motifs, boxA and boxB, characteristic of the BTG/Tob APRO domain. Consistently, these proteins were shown to stimulate mRNA deadenylation and decay in several instances. Two members of the family, BTG1 and BTG2, were reported further to associate with the protein arginine methyltransferase PRMT1 through a motif, boxC, conserved only in this subset of proteins. We recently demonstrated that BTG1 and BTG2 also contact the first RRM domain of the cytoplasmic poly(A) binding protein PABPC1. To decipher the mode of interaction of BTG1 and BTG2 with partners, we performed nuclear magnetic resonance experiments as well as mutational and biochemical analyses. Our data demonstrate that, in the context of an APRO domain, the boxC motif is necessary and sufficient to allow interaction with PABPC1 but, unexpectedly, that it is not required for BTG2 association with PRMT1. We show further that the presence of a boxC motif in an APRO domain endows it with the ability to stimulate deadenylation in cellulo and in vitro. Overall, our results identify the molecular interface allowing BTG1 and BTG2 to activate deadenylation, a process recently shown to be necessary for maintaining T-cell quiescence.

Non-technical skills and device-related interruptions in minimally invasive surgery.

BACKGROUND: Device-related interruptions in the operating room (OR) may create stress among health care providers and delays. Although non-technical skills (NTS) of the OR teams, such as situational awareness and communication, are expected to influence device-related interruptions, empirical data on this relationship are limited. METHODS: We performed a prospective cohort study of 144 consecutive elective laparoscopic operations during 13 months. A data capture system called the OR Black Box® was used to characterize device-related interruptions, NTS, and distractions. Device-related interruptions were classified according to a priori established categories. Positive and negative NTS instances were identified according to validated measurement tools specific for nurses and surgeons. We assessed the relationship between NTS and device-related interruptions after adjusting for potential confounders. RESULTS: A total of 86 device-related interruptions occurred in 48 of 144 operations (33%). They were most frequently classified as device failure (54%) followed by improper assembly (19%) and disconnection (14%). Medians of 1 [interquartile range (IQR) 0-3] and 1 (IQR 0-2) negative NTS instance per operation were demonstrated by nurses and surgeons, respectively. Medians of 28 (IQR 15-38) and 40 (IQR 28-118) positive NTS instances per operation were demonstrated by nurses and surgeons. In a multivariable analysis, a higher frequency of negative NTS instances demonstrated by nurses was associated with device-related interruptions after risk adjustment (Odds Ratio 1.33, p = 0.02). CONCLUSIONS: In elective laparoscopic operations, an increased likelihood of device-related interruptions in the OR was associated with more frequent negative NTS demonstrations by nursing teams.

Rational approaches for the design of various GABA modulators and their clinical progression.

GABA (γ-amino butyric acid) is an important inhibitory neurotransmitter in the central nervous system. Attenuation of GABAergic neurotransmission plays an important role in the etiology of several neurological disorders including epilepsy, Alzheimer's disease, Huntington's chorea, migraine, Parkinson's disease, neuropathic pain, and depression. Increase in the GABAergic activity may be achieved through direct agonism at the GABAA receptors, inhibition of enzymatic breakdown of GABA, or by inhibition of the GABA transport proteins (GATs). These functionalities make GABA receptor modulators and GATs attractive drug targets in brain disorders associated with decreased GABA activity. There have been several reports of development of GABA modulators (GABA receptors, GABA transporters, and GABAergic enzyme inhibitors) in the past decade. Therefore, the focus of the present review is to provide an overview on various design strategies and synthetic approaches toward developing GABA modulators. Furthermore, mechanistic insights, structure-activity relationships, and molecular modeling inputs for the biologically active derivatives have also been discussed. Summary of the advances made over the past few years in the clinical translation and development of GABA receptor modulators is also provided. This compilation will be of great interest to the researchers working in the field of neuroscience. From the light of detailed literature, it can be concluded that numerous molecules have displayed significant results and their promising potential, clearly placing them ahead as potential future drug candidates.

New coumarin-benzotriazole based hybrid molecules as inhibitors of acetylcholinesterase and amyloid aggregation.

A novel series of triazole tethered coumarin-benzotriazole hybrids based on donepezil skeleton has been designed and synthesized as multifunctional agents for the treatment of Alzheimer's disease (AD). Among the synthesized compounds 13b showed most potent acetylcholinesterase (AChE) inhibition (IC50 = 0.059 µΜ) with mixed type inhibition scenario. Structure-activity relationship revealed that three-carbon alkyl chain connecting coumarin and triazole is well tolerable for inhibitory potential. Hybrids obtained from 4-hydroxycoumarin and 1-benzotriazole were most potent AChE inhibitors. The inhibitory potential of all compounds against butyrylcholinesterase was also evaluated but all showed negligible activity suggesting that the hybrid molecules are selective AChE inhibitors. 13b (most potent AChE inhibitor) also showed copper-induced Aß1-42 aggregation inhibition (34.26% at 50 µΜ) and chelating properties for metal ions (Cu2+, Fe2+, and Zn2+) involved in AD pathogenesis along with DNA protective potential against degenerative actions of OH radicals. Molecular modelling studies confirm the potential of 13b in blocking both PAS and CAS of AChE. In addition, interactions of 13b with Aß1-42 monomer are also streamlined. Therefore, hybrid 13b can act as an effective hit lead molecule for further development of selective AChE inhibitors as multifunctional anti-Alzheimer's agents.

Structures of Hsp90α and Hsp90ß bound to a purine-scaffold inhibitor reveal an exploitable residue for drug selectivity.

Hsp90α and Hsp90ß are implicated in a number of cancers and neurodegenerative disorders but the lack of selective pharmacological probes confounds efforts to identify their individual roles. Here, we analyzed the binding of an Hsp90α-selective PU compound, PU-11-trans, to the two cytosolic paralogs. We determined the co-crystal structures of Hsp90α and Hsp90ß bound to PU-11-trans, as well as the structure of the apo Hsp90ß NTD. The two inhibitor-bound structures reveal that Ser52, a nonconserved residue in the ATP binding pocket in Hsp90α, provides additional stability to PU-11-trans through a water-mediated hydrogen-bonding network. Mutation of Ser52 to alanine, as found in Hsp90ß, alters the dissociation constant of Hsp90α for PU-11-trans to match that of Hsp90ß. Our results provide a structural explanation for the binding preference of PU inhibitors for Hsp90α and demonstrate that the single nonconserved residue in the ATP-binding pocket may be exploited for α/ß selectivity.

Mitochondrial metabolism: a common link between neuroinflammation and neurodegeneration.

Neurodegenerative disorders have been considered as a growing health concern for decades. Increasing risk of neurodegenerative disorders creates a socioeconomic burden to both patients and care givers. Mitochondria are organelle that are involved in both neuroinflammation and neurodegeneration. There are few reports on the effect of mitochondrial metabolism on the progress of neurodegeneration and neuroinflammation. Therefore, the present review summarizes the potential contribution of mitochondrial metabolic pathways in the pathogenesis of neuroinflammation and neurodegeneration. Mitochondrial pyruvate metabolism plays a critical role in the pathogenesis of neurodegenerative disorders such as Parkinson's disease and Alzheimer's disease. However, there its potential contribution in other neurodegenerative disorders is as yet unproven. The mitochondrial pyruvate carrier and pyruvate dehydrogenase can modulate mitochondrial pyruvate metabolism to attenuate neuroinflammation and neurodegeneration. Further, it has been observed that the mitochondrial citric acid cycle can regulate the pathogenesis of neuroinflammation and neurodegeneration. Additional research should be undertaken to target tricarboxylic acid cycle enzymes to minimize the progress of neuroinflammation and neurodegeneration. It has also been observed that the mitochondrial urea cycle can potentially contribute to the progression of neurodegenerative disorders. Therefore, targeting this pathway may control the mitochondrial dysfunction-induced neuroinflammation and neurodegeneration. Furthermore, the mitochondrial malate-aspartate shuttle could be another target to control mitochondrial dysfunction-induced neuroinflammation and neurodegeneration in neurodegenerative disorders.

Rational approaches, design strategies, structure activity relationship and mechanistic insights for therapeutic coumarin hybrids.

Hybrid molecules, furnished by combining two or more pharmacophores is an emerging concept in the field of medicinal chemistry and drug discovery that has attracted substantial traction in the past few years. Naturally occurring scaffolds such as coumarins display a wide spectrum of pharmacological activities including anticancer, antibiotic, antidiabetic and others, by acting on multiple targets. In this view, various coumarin-based hybrids possessing diverse medicinal attributes were synthesized in the last five years by conjugating coumarin moiety with other therapeutic pharmacophores. The current review summarizes the recent development (2014 and onwards) of these pharmacologically active coumarin hybrids and demonstrates rationale behind their design, structure-activity relationships (SAR) and mechanistic studies performed on these hybrid molecules. This review will be beneficial for medicinal chemist and chemical biologist, and in general to the drug discovery community and will facilitate the synthesis and development of novel, potent coumarin hybrid molecules serving as lead molecules for the treatment of complex disorders.

Characterization of device-related interruptions in minimally invasive surgery: need for intraoperative data and effective mitigation strategies.

BACKGROUND: The burden of device-related interruptions is expected to increase as modern surgical practices adopt complex minimally invasive surgery devices. Currently, there is a paucity of empiric data that examined the nature of device-related interruptions using comprehensive intraoperative data. METHODS: We performed a cross-sectional study of consecutive elective laparoscopic general surgery cases performed in one operating room (OR) at a referral center between April 2014 and April 2016. The included cases were directly observed using a comprehensive multiport data recorder called the OR Black Box. The data were synchronized, encrypted, and reviewed by expert surgeon assessors. The assessors characterized device-related interruptions that occurred during operations. The prevalence of the cases with device-related interruptions was calculated. Device-related interruptions were classified into a priori categories of (1) absent/wrong device; (2) improper assembly; (3) loss of sterility; (4) disconnection; and (5) device failure. RESULTS: In a cohort of 210 cases, 64 (30%) had at least one device-related interruption. Sleeve gastrectomy (52%) and oncologic gastrectomy (43%) procedures experienced the highest prevalence of device-related interruptions. Device failure was the most frequently chosen category with laparoscopic staplers implicated in more than half of these failures. Three failure modes were described for laparoscopic stapler, of which stapler malfunction (46%) was the most common. CONCLUSIONS: Device-related interruptions occurred frequently in the OR and could be characterized into one of the five categories. Understanding the nature of the device-related interruptions can help guide implementation of safety interventions and user training in the future.

CBP-mediated SMN acetylation modulates Cajal body biogenesis and the cytoplasmic targeting of SMN.

The survival of motor neuron (SMN) protein plays an essential role in the biogenesis of spliceosomal snRNPs and the molecular assembly of Cajal bodies (CBs). Deletion of or mutations in the SMN1 gene cause spinal muscular atrophy (SMA) with degeneration and loss of motor neurons. Reduced SMN levels in SMA lead to deficient snRNP biogenesis with consequent splicing pathology. Here, we demonstrate that SMN is a novel and specific target of the acetyltransferase CBP (CREB-binding protein). Furthermore, we identify lysine (K) 119 as the main acetylation site in SMN. Importantly, SMN acetylation enhances its cytoplasmic localization, causes depletion of CBs, and reduces the accumulation of snRNPs in nuclear speckles. In contrast, the acetylation-deficient SMNK119R mutant promotes formation of CBs and a novel category of promyelocytic leukemia (PML) bodies enriched in this protein. Acetylation increases the half-life of SMN protein, reduces its cytoplasmic diffusion rate and modifies its interactome. Hence, SMN acetylation leads to its dysfunction, which explains the ineffectiveness of HDAC (histone deacetylases) inhibitors in SMA therapy despite their potential to increase SMN levels.