Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.931
Filter
2.
J Exp Biol ; 227(13)2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38953226

ABSTRACT

The Cape fur seal (Arctocephalus pusillus pusillus) is one of the most colonial mammals, with colonies of up to hundreds of thousands of individuals during the breeding season. During the lactation period, mothers and pups are regularly separated as females undertake multi-day foraging trips at sea. Mothers and pups use a mutual vocal recognition system to reunite after separation. Such communication is highly constrained by both high background noise and risk of individual confusion owing to the density of seals. This study aimed to experimentally assess the acoustic features relevant for mother-pup vocal identification and the propagation properties of their calls. Playback experiments revealed that mother and pup individual vocal signatures rely on both temporal and frequency parameters: amplitude and frequency modulations, timbre and fundamental frequency (f0). This is more parameters than in any colonial species studied so far. The combinational use of acoustic features reinforces the concept that both environmental and social constraints may have acted as selective pressures on the individual vocal recognition systems. Theoretical propagation distances of mother and pup vocalisations were estimated to be below the range of distances at which mother-pup reunions can occur. This suggests that Cape fur seals may have strong abilities to extract vocal signals from the background noise, as previously demonstrated in the highly colonial king penguin. Investigating the transmission of information throughout the propagation of the signal as well as the ability of the receiving individual to decipher vocal signatures is crucial to understanding vocal recognition systems in the wild.


Subject(s)
Acoustics , Fur Seals , Vocalization, Animal , Animals , Fur Seals/physiology , Female , Homing Behavior
3.
BMJ Open ; 14(6): e079158, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38866568

ABSTRACT

INTRODUCTION: Severe Graves' disease is a life-changing condition with poor outcomes from currently available treatments. It is caused by directly pathogenic thyroid-stimulating hormone receptor-stimulating antibodies (TRAb), which are secreted from plasma cells. The human anti-CD38 monoclonal antibody daratumumab was developed to target plasma cells which express high levels of CD38, and is currently licensed for treatment of the plasma cell malignancy, myeloma. However, it can also deplete benign plasma cells with the potential to reduce TRAb and alter the natural history of severe Graves' disease. This study aims to establish proof of concept that daratumumab has efficacy in patients with severe Graves' disease and will provide important data to inform a choice of dosing regimen for subsequent trials. METHODS AND ANALYSIS: The Graves-PCD trial aims to determine if daratumumab modulates the humoral immune response in patients with severe Graves' disease, and if so, over what time period, and to find an optimal dose. It is a single-blinded, randomised, dose-finding, adaptive trial using four different doses of daratumumab or placebo in 30 adult patients. Part 1 of the trial is dose-finding and, following an interim analysis, in part 2, the remaining patients will be randomised between the chosen dose(s) from the interim analysis or placebo. The primary outcome is the percentage change in serum TRAb from baseline to 12 weeks. ETHICS AND DISSEMINATION: The trial received a favourable ethical opinion from London-Hampstead Research Ethics Committee (reference 21/LO/0449). The results of this trial will be disseminated at international meetings, in the peer-reviewed literature and through partner patient group newsletters and presentations at patient education events. TRIAL REGISTRATION NUMBER: ISRCTN81162400.


Subject(s)
Antibodies, Monoclonal , Graves Disease , Humans , Graves Disease/drug therapy , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal/administration & dosage , Randomized Controlled Trials as Topic , Plasma Cells/drug effects , Single-Blind Method , Adult , Male , Female , Dose-Response Relationship, Drug
5.
Chem Commun (Camb) ; 60(55): 7077-7080, 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38895782

ABSTRACT

This study investigates the effects of elevated temperature thermal treatments on the direct air capture of CO2 by aminosilane-grafted SBA-15 silica sorbents. Exposing samples to high temperatures (200-250 °C compared to 80-120 °C) in an inert environment resulted in improved CO2 capacity (5-21%) that was sustained over multiple adsorption/desorption cycles.

6.
PLoS Pathog ; 20(5): e1012158, 2024 May.
Article in English | MEDLINE | ID: mdl-38805567

ABSTRACT

SARS-CoV-2 is the third known coronavirus (CoV) that has crossed the animal-human barrier in the last two decades. However, little structural information exists related to the close genetic species within the SARS-related coronaviruses. Here, we present three novel SARS-related CoV spike protein structures solved by single particle cryo-electron microscopy analysis derived from bat (bat SL-CoV WIV1) and civet (cCoV-SZ3, cCoV-007) hosts. We report complex glycan trees that decorate the glycoproteins and density for water molecules which facilitated modeling of the water molecule coordination networks within structurally important regions. We note structural conservation of the fatty acid binding pocket and presence of a linoleic acid molecule which are associated with stabilization of the receptor binding domains in the "down" conformation. Additionally, the N-terminal biliverdin binding pocket is occupied by a density in all the structures. Finally, we analyzed structural differences in a loop of the receptor binding motif between coronaviruses known to infect humans and the animal coronaviruses described in this study, which regulate binding to the human angiotensin converting enzyme 2 receptor. This study offers a structural framework to evaluate the close relatives of SARS-CoV-2, the ability to inform pandemic prevention, and aid in the development of pan-neutralizing treatments.


Subject(s)
Chiroptera , Cryoelectron Microscopy , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Spike Glycoprotein, Coronavirus/genetics , SARS-CoV-2/chemistry , Animals , Humans , Chiroptera/virology , COVID-19/virology , Binding Sites , Betacoronavirus , Amino Acid Motifs , Severe acute respiratory syndrome-related coronavirus/chemistry , Severe acute respiratory syndrome-related coronavirus/metabolism , Severe acute respiratory syndrome-related coronavirus/genetics , Models, Molecular , Protein Binding
7.
J Clin Invest ; 2024 May 09.
Article in English | MEDLINE | ID: mdl-38722695

ABSTRACT

Spinal Muscular Atrophy (SMA) is typically characterized as a motor neuron disease, but extra-neuronal phenotypes are present in almost every organ in severely affected patients and animal models. Extra-neuronal phenotypes were previously underappreciated as patients with severe SMA phenotypes usually died in infancy; however, with current treatments for motor neurons increasing patient lifespan, impaired function of peripheral organs may develop into significant future comorbidities and lead to new treatment-modified phenotypes. Fatty liver is seen in SMA animal models , but generalizability to patients and whether this is due to hepatocyte-intrinsic Survival Motor Neuron (SMN) protein deficiency and/or subsequent to skeletal muscle denervation is unknown. If liver pathology in SMA is SMN-dependent and hepatocyte-intrinsic, this suggests SMN repleting therapies must target extra-neuronal tissues and motor neurons for optimal patient outcome. Here we showed that fatty liver is present in SMA and that SMA patient-specific iHeps were susceptible to steatosis. Using proteomics, functional studies and CRISPR/Cas9 gene editing, we confirmed that fatty liver in SMA is a primary SMN-dependent hepatocyte-intrinsic liver defect associated with mitochondrial and other hepatic metabolism implications. These pathologies require monitoring and indicate need for systematic clinical surveillance and additional and/or combinatorial therapies to ensure continued SMA patient health.

8.
ACS Biomater Sci Eng ; 10(6): 3806-3812, 2024 06 10.
Article in English | MEDLINE | ID: mdl-38709857

ABSTRACT

In this work, for the first time, we demonstrate light control of a therapeutic protein's release from a depot in the subcutaneous layer of the skin. The subcutaneous layer is a standard location for therapeutic protein depots due to its large size and ease of access, but prior attempts to utilize this space failed because insufficient light can reach this deeper layer. An analysis of existing biophysical literature suggested that an increase of photoactivation wavelength from 365 to 500 nm could allow an increase of depot irradiation in the subcutaneous by >100-fold. We therefore used a green light-activated thio-coumarin-based material and demonstrated robust release of a therapeutic, insulin, in response to skin illumination with an LED light source. We further demonstrated that this release is ultrafast, as fast or faster than any commercially used insulin, while maintaining the native insulin sequence. This release of insulin was then accompanied by a robust reduction in blood glucose, demonstrating the retention of bioactivity despite the synthetic processing required to generate the material. In addition, we observed that the material exhibits slow basal release of insulin, even in the absence of light, potentially through biochemical or photochemical unmasking of insulin. Thus, these materials can act much like the healthy pancreas does: releasing insulin at a slow basal rate and then, upon skin irradiation, releasing an ultrafast bolus of native insulin to reduce postprandial blood glucose excursions.


Subject(s)
Insulin , Light , Animals , Blood Glucose/metabolism , Blood Glucose/drug effects , Humans , Skin/metabolism , Skin/radiation effects , Skin/drug effects , Coumarins/chemistry , Subcutaneous Tissue/drug effects , Subcutaneous Tissue/metabolism , Male , Green Light
9.
J Plast Reconstr Aesthet Surg ; 93: 281-289, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38728901

ABSTRACT

PURPOSE: This work aimed to investigate the validity of wearable activity monitors (WAMs) as an objective tool to measure the return toward normal functional mobility following abdominal wall surgery. This was achieved by quantifying and comparing pre- and postoperative physical activity (PA). METHODS: A multicenter, prospective, observational cohort study was designed. Patients undergoing abdominal wall surgery were assessed for eligibility and consent for study participation was obtained. Participants were asked to wear a WAM (AX3, Axivity) on the wrist of their dominant hand at least 48 hours pre-operatively, for up to 2 weeks postop, and again after 6 months postop for 48 hours. RESULTS: A cohort of 20 patients were recruited in this validation study with a mean age of 47.3 ± 13.0 years. Postoperation, the percentage median PA (±IQR) dropped to 32.6% (20.1), whereas on day 14, PA had reached 64.6% (22.7) of the preoperative value providing construct validity. Activity levels at >6 months postop increased by 16.4% on an average when compared to baseline preoperative PA (p = 0.046). CONCLUSION: This study demonstrates that WAMs are valid markers of postoperative recovery following abdominal wall surgery. This was achieved by quantifying the reduction in PA postoperation, which has not been previously shown. In addition, this study suggests that abdominal wall surgery may improve the patient's quality of life via increased functional mobility at 6 months postop. In the future, this technology could be used to identify the patient and surgical factors that are predictors of outcome following abdominal wall surgery.


Subject(s)
Abdominal Wall , Recovery of Function , Wearable Electronic Devices , Humans , Middle Aged , Male , Female , Prospective Studies , Abdominal Wall/surgery , Adult , Exercise/physiology , Postoperative Period
10.
Nat Commun ; 15(1): 2910, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38632262

ABSTRACT

Malnutrition underlies almost half of all child deaths globally. Severe Acute Malnutrition (SAM) carries unacceptable mortality, particularly if accompanied by infection or medical complications, including enteropathy. We evaluated four interventions for malnutrition enteropathy in a multi-centre phase II multi-arm trial in Zambia and Zimbabwe and completed in 2021. The purpose of this trial was to identify therapies which could be taken forward into phase III trials. Children of either sex were eligible for inclusion if aged 6-59 months and hospitalised with SAM (using WHO definitions: WLZ <-3, and/or MUAC <11.5 cm, and/or bilateral pedal oedema), with written, informed consent from the primary caregiver. We randomised 125 children hospitalised with complicated SAM to 14 days treatment with (i) bovine colostrum (n = 25), (ii) N-acetyl glucosamine (n = 24), (iii) subcutaneous teduglutide (n = 26), (iv) budesonide (n = 25) or (v) standard care only (n = 25). The primary endpoint was a composite of faecal biomarkers (myeloperoxidase, neopterin, α1-antitrypsin). Laboratory assessments, but not treatments, were blinded. Per-protocol analysis used ANCOVA, adjusted for baseline biomarker value, sex, oedema, HIV status, diarrhoea, weight-for-length Z-score, and study site, with pre-specified significance of P < 0.10. Of 143 children screened, 125 were randomised. Teduglutide reduced the primary endpoint of biomarkers of mucosal damage (effect size -0.89 (90% CI: -1.69,-0.10) P = 0.07), while colostrum (-0.58 (-1.4, 0.23) P = 0.24), N-acetyl glucosamine (-0.20 (-1.01, 0.60) P = 0.67), and budesonide (-0.50 (-1.33, 0.33) P = 0.32) had no significant effect. All interventions proved safe. This work suggests that treatment of enteropathy may be beneficial in children with complicated malnutrition. The trial was registered at ClinicalTrials.gov with the identifier NCT03716115.


Subject(s)
Intestinal Diseases , Malnutrition , Severe Acute Malnutrition , Animals , Cattle , Humans , Infant , Acetylglucosamine , Biomarkers , Budesonide , Edema , Zambia , Zimbabwe , Child, Preschool
11.
Noncoding RNA Res ; 9(3): 649-658, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38577022

ABSTRACT

In recent years, various long non-coding RNAs (lncRNAs) involved in DNA damage response (DDR) have been identified and studied to deepen our understanding. However, there are rare reports on the association between lncRNAs and base excision repair (BER). Our designed DNA microarray identified dozens of functionally unknown lncRNAs, and their transcription levels significantly increased upon exposure to DNA damage inducers. One of them, named LIP (Long noncoding RNA Interacts with PARP-1), exhibited a significant alteration in transcription in response to methyl methanesulfonate (MMS) and temozolomide (TMZ) treatments. LIP knockdown or knockout cell lines are sensitive to MMS and TMZ, indicating that LIP plays a crucial role in DDR. The loss or insufficiency of LIP significantly influences the efficiency of BER in human cells, and it suggests that LIP participates in the BER pathway. The interaction between LIP and a key factor in BER, poly (ADP-ribose) polymerase 1 (PARP-1), has been confirmed. We identified and characterized LIP, a lncRNA, which is involved in DDR, significantly influences BER efficiency, and interacts with the BER key factor PARP-1. This advances our understanding of the connection between lncRNAs and BER, presenting the potential for the discovery of new drug targets.

12.
Nucleic Acids Res ; 52(8): 4124-4136, 2024 May 08.
Article in English | MEDLINE | ID: mdl-38554107

ABSTRACT

Pharmacological modulation of RNA splicing by small molecules is an emerging facet of drug discovery. In this context, the SMN2 splicing modifier SMN-C5 was used as a prototype to understand the mode of action of small molecule splicing modifiers and propose the concept of 5'-splice site bulge repair. In this study, we combined in vitro binding assays and structure determination by NMR spectroscopy to identify the binding modes of four other small molecule splicing modifiers that switch the splicing of either the SMN2 or the HTT gene. Here, we determined the solution structures of risdiplam, branaplam, SMN-CX and SMN-CY bound to the intermolecular RNA helix epitope containing an unpaired adenine within the G-2A-1G+1U+2 motif of the 5'-splice site. Despite notable differences in their scaffolds, risdiplam, SMN-CX, SMN-CY and branaplam contact the RNA epitope similarly to SMN-C5, suggesting that the 5'-splice site bulge repair mechanism can be generalised. These findings not only deepen our understanding of the chemical diversity of splicing modifiers that target A-1 bulged 5'-splice sites, but also identify common pharmacophores required for modulating 5'-splice site selection with small molecules.


Subject(s)
Drug Design , RNA Splice Sites , RNA Splicing , Humans , Azo Compounds , Models, Molecular , Nucleic Acid Conformation , Pyrimidines , RNA Splicing/drug effects , Survival of Motor Neuron 2 Protein/genetics , Survival of Motor Neuron 2 Protein/metabolism
13.
Front Neurosci ; 18: 1286130, 2024.
Article in English | MEDLINE | ID: mdl-38529267

ABSTRACT

Introduction: Interpersonal synchronization involves the alignment of behavioral, affective, physiological, and brain states during social interactions. It facilitates empathy, emotion regulation, and prosocial commitment. Mental disorders characterized by social interaction dysfunction, such as Autism Spectrum Disorder (ASD), Reactive Attachment Disorder (RAD), and Social Anxiety Disorder (SAD), often exhibit atypical synchronization with others across multiple levels. With the introduction of the "second-person" neuroscience perspective, our understanding of interpersonal neural synchronization (INS) has improved, however, so far, it has hardly impacted the development of novel therapeutic interventions. Methods: To evaluate the potential of INS-based treatments for mental disorders, we performed two systematic literature searches identifying studies that directly target INS through neurofeedback (12 publications; 9 independent studies) or brain stimulation techniques (7 studies), following PRISMA guidelines. In addition, we narratively review indirect INS manipulations through behavioral, biofeedback, or hormonal interventions. We discuss the potential of such treatments for ASD, RAD, and SAD and using a systematic database search assess the acceptability of neurofeedback (4 studies) and neurostimulation (4 studies) in patients with social dysfunction. Results: Although behavioral approaches, such as engaging in eye contact or cooperative actions, have been shown to be associated with increased INS, little is known about potential long-term consequences of such interventions. Few proof-of-concept studies have utilized brain stimulation techniques, like transcranial direct current stimulation or INS-based neurofeedback, showing feasibility and preliminary evidence that such interventions can boost behavioral synchrony and social connectedness. Yet, optimal brain stimulation protocols and neurofeedback parameters are still undefined. For ASD, RAD, or SAD, so far no randomized controlled trial has proven the efficacy of direct INS-based intervention techniques, although in general brain stimulation and neurofeedback methods seem to be well accepted in these patient groups. Discussion: Significant work remains to translate INS-based manipulations into effective treatments for social interaction disorders. Future research should focus on mechanistic insights into INS, technological advancements, and rigorous design standards. Furthermore, it will be key to compare interventions directly targeting INS to those targeting other modalities of synchrony as well as to define optimal target dyads and target synchrony states in clinical interventions.

14.
Pharmaceuticals (Basel) ; 17(3)2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38543158

ABSTRACT

A novel trimethyltin(IV) complex (Me3SnL), derived from 3-(4-methyl-2-oxoquinolin-1(2H)-yl)propanoate ligand, has been synthesized and characterized by elemental microanalysis, UV/Vis spectrophotometry, FT-IR and multinuclear (1H, 13C and 119Sn) NMR spectroscopies. Furthermore, the structure of the ligand precursor HL was solved using SC-XRD (single-crystal X-ray diffraction). The prediction of UV/Vis and NMR spectra by quantum-chemical methods was performed and compared to experimental findings. The protein binding affinity of Me3SnL towards BSA was determined by spectrofluorometric titration and subsequent molecular docking simulations. Me3SnL has been evaluated for its in vitro anticancer activity against three human cell lines, MCF-7 (breast adenocarcinoma), A375 (melanoma) and HCT116 (colorectal carcinoma), and three mouse tumor cell lines, 4T1 (breast carcinoma), B16 (melanoma) and CT26 (colon carcinoma), using MTT and CV assays. The strong inhibition of A375 cell proliferation, ROS/RNS upregulation and robust lipid peroxidation lead to autophagic cell death upon treatment with Me3SnL.

15.
Mol Biol Evol ; 41(3)2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38401262

ABSTRACT

Hypolimnas misippus is a Batesian mimic of the toxic African Queen butterfly (Danaus chrysippus). Female H. misippus butterflies use two major wing patterning loci (M and A) to imitate three color morphs of D. chrysippus found in different regions of Africa. In this study, we examine the evolution of the M locus and identify it as an example of adaptive atavism. This phenomenon involves a morphological reversion to an ancestral character that results in an adaptive phenotype. We show that H. misippus has re-evolved an ancestral wing pattern present in other Hypolimnas species, repurposing it for Batesian mimicry of a D. chrysippus morph. Using haplotagging, a linked-read sequencing technology, and our new analytical tool, Wrath, we discover two large transposable element insertions located at the M locus and establish that these insertions are present in the dominant allele responsible for producing mimetic phenotype. By conducting a comparative analysis involving additional Hypolimnas species, we demonstrate that the dominant allele is derived. This suggests that, in the derived allele, the transposable elements disrupt a cis-regulatory element, leading to the reversion to an ancestral phenotype that is then utilized for Batesian mimicry of a distinct model, a different morph of D. chrysippus. Our findings present a compelling instance of convergent evolution and adaptive atavism, in which the same pattern element has independently evolved multiple times in Hypolimnas butterflies, repeatedly playing a role in Batesian mimicry of diverse model species.


Subject(s)
Biological Mimicry , Butterflies , Animals , Butterflies/genetics , DNA Transposable Elements , Biological Mimicry/genetics , Phenotype , Africa , Wings, Animal/anatomy & histology
17.
J Rheumatol ; 51(4): 378-389, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38224992

ABSTRACT

OBJECTIVE: To evaluate patient-reported outcomes (PROs) after initiation of tumor necrosis factor inhibitor (TNFi) treatment in European real-world patients with psoriatic arthritis (PsA). Further, to investigate PRO remission rates across treatment courses, registries, disease duration, sex, and age at disease onset. METHODS: Visual analog scale or numerical rating scale scores for pain, fatigue, patient global assessment (PtGA), and the Health Assessment Questionnaire-Disability Index (HAQ-DI) from 12,262 patients with PsA initiating a TNFi in 13 registries were pooled. PRO remission rates (pain ≤ 1, fatigue ≤ 2, PtGA ≤ 2, and HAQ-DI ≤ 0.5) were calculated for patients still on the treatment. RESULTS: For the first TNFi, median pain score was reduced by approximately 50%, from 6 to 3, 3, and 2; as were fatigue scores, from 6 to 4, 4, and 3; PtGA scores, from 6 to 3, 3, and 2; and HAQ-DI scores, from 0.9 to 0.5, 0.5, and 0.4 at baseline, 6, 12, and 24 months, respectively. Six-month Lund Efficacy Index (LUNDEX)-adjusted remission rates for pain, fatigue, PtGA, and HAQ-DI scores were 24%, 31%, 36%, and 43% (first TNFi); 14%, 19%, 23%, and 29% (second TNFi); and 9%, 14%, 17%, and 20% (third TNFi), respectively. For biologic-naïve patients with disease duration < 5 years, 6-month LUNDEX-adjusted remission rates for pain, fatigue, PtGA, and HAQ-DI scores were 22%, 28%, 33%, and 42%, respectively. Corresponding rates for patients with disease duration > 10 years were 27%, 32%, 41%, and 43%, respectively. Remission rates were 33%, 40%, 45%, and 56% for men and 17%, 23%, 24%, and 32% for women, respectively. For patients aged < 45 years at diagnosis, 6-month LUNDEX-adjusted remission rate for pain was 29% vs 18% for patients ≥ 45 years. CONCLUSION: In 12,262 biologic-naïve patients with PsA, 6 months of treatment with a TNFi reduced pain by approximately 50%. Marked differences in PRO remission rates across treatment courses, registries, disease duration, sex, and age at onset of disease were observed, emphasizing the potential influence of factors other than disease activity on PROs.


Subject(s)
Antirheumatic Agents , Arthritis, Psoriatic , Biological Products , Male , Humans , Female , Arthritis, Psoriatic/drug therapy , Arthritis, Psoriatic/diagnosis , Tumor Necrosis Factor Inhibitors/therapeutic use , Antirheumatic Agents/therapeutic use , Treatment Outcome , Patient Reported Outcome Measures , Pain/drug therapy , Biological Products/therapeutic use
18.
Structure ; 32(4): 393-399.e3, 2024 Apr 04.
Article in English | MEDLINE | ID: mdl-38237595

ABSTRACT

F1Fo ATP synthase interchanges phosphate transfer energy and proton motive force via a rotary catalytic mechanism and isolated F1-ATPase subcomplexes can also hydrolyze ATP to generate rotation of their central γ rotor subunit. As ATP is hydrolyzed, the F1-ATPase cycles through a series of conformational states that mediates unidirectional rotation of the rotor. However, even in the absence of a rotor, the α and ß subunits are still able to pass through a series of conformations, akin to those that generate rotation. Here, we use cryoelectron microscopy to establish the structures of these rotorless states. These structures indicate that cooperativity in this system is likely mediated by contacts between the ß subunit lever domains, irrespective of the presence of the γ rotor subunit. These findings provide insight into how long-range information may be transferred in large biological systems.


Subject(s)
Adenosine Triphosphatases , Adenosine Triphosphate , Hydrolysis , Cryoelectron Microscopy , Protein Subunits/chemistry , Protein Conformation , Rotation
19.
bioRxiv ; 2024 Jan 11.
Article in English | MEDLINE | ID: mdl-38260523

ABSTRACT

Mammalian DNA replication employs several RecQ DNA helicases to orchestrate the faithful duplication of genetic information. Helicase function is often coupled to the activity of specific nucleases, but how helicase and nuclease activities are co-directed is unclear. Here we identify the inactive ubiquitin-specific protease, USP50, as a ubiquitin-binding and chromatin-associated protein required for ongoing replication, fork restart, telomere maintenance and cellular survival during replicative stress. USP50 supports WRN:FEN1 at stalled replication forks, suppresses MUS81-dependent fork collapse and restricts double-strand DNA breaks at GC-rich sequences. Surprisingly we find that cells depleted for USP50 and recovering from a replication block exhibit increased DNA2 and RECQL4 foci and that the defects in ongoing replication, poor fork restart and increased fork collapse seen in these cells are mediated by DNA2, RECQL4 and RECQL5. These data define a novel ubiquitin-dependent pathway that promotes the balance of helicase: nuclease use at ongoing and stalled replication forks.

20.
Acta Anaesthesiol Scand ; 68(1): 91-100, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37729943

ABSTRACT

BACKGROUND: In the Difficult Airway Society's 2015 "cannot intubate, cannot oxygenate" guideline, the emergency cricothyroidotomy is the final option when managing an unanticipated difficult airway. How often training for maintenance of this skill is required for anesthesiologists remains unknown. We aimed to assess if specialist-trained anesthesiologists' skills improved from a brush-up intervention and if skills were retained after 3 months. METHODS: In this multicenter, randomized, controlled trial, participants were randomized to either a simulation-based brush-up or no brush-up. Both groups performed a mannequin-based technical skills emergency cricothyroidotomy test twice and were assessed by a blinded rater using a structured assessment tool that included time, positioning, palpation, appropriate employment of instruments, and stepwise progression. After 3 months of non-training, participants completed identical tests of retention. RESULTS: A total of 54 anesthesiologists were included from three hospitals in the Region of Southern Denmark. Thirty-seven percent of the participants had received skills training in emergency cricothyroidotomy in the prior 12 months. The intervention group (N = 27) performed better in the initial tests, with a mean time of 51.5 s (SD = 10.82), a total score per minute of 15.9 points (SD = 4.91), and 93% passing both initial tests compared to the control group (N = 27) with a mean time of 76.8 s (SD = 35.82), a total score per minute of 6.6 (SD = 4.68) and only 15% passing both initial tests. The intervention group managed to retain overall performance in retention tests in terms of performance time (48.9 s, p = .26), total score per minute (13.6 points, p = .094), and passing the tests (75%, p = .059). CONCLUSION: Exposure to simulation-based brush-up training in emergency cricothyroidotomy improved anesthesiologists' technical performance and was overall retained after 3 months. Some loss of skill concerning specific items was observed, highlighting the need for regular training in emergency cricothyroidotomy. Simulation-based training should be prioritized to improve and maintain technical skills in infrequent high-stakes procedures.


Subject(s)
Internship and Residency , Simulation Training , Humans , Anesthesiologists , Clinical Competence , Manikins
SELECTION OF CITATIONS
SEARCH DETAIL
...