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1.
Cancer Cytopathol ; 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39207803

RESUMO

BACKGROUND: The authors previously developed an artificial intelligence (AI) to assist cytologists in the evaluation of digital whole-slide images (WSIs) generated from bile duct brushing specimens. The aim of this trial was to assess the efficiency and accuracy of cytologists using a novel application with this AI tool. METHODS: Consecutive bile duct brushing WSIs from indeterminate strictures were obtained. A multidisciplinary panel reviewed all relevant information and provided a central interpretation for each WSI as being "positive," "negative," or "indeterminate." The WSIs were then uploaded to the AI application. The AI scored each WSI as positive or negative for malignancy (i.e., computer-aided diagnosis [CADx]). For each WSI, the AI prioritized cytologic tiles by the likelihood that malignant material was present in the tile. Via the AI, blinded cytologists reviewed all WSIs and provided interpretations (i.e., computer-aided detection [CADe]). The diagnostic accuracies of the WSI evaluation via CADx, CADe, and the original clinical cytologic interpretation (official cytologic interpretation [OCI]) were compared. RESULTS: Of the 84 WSIs, 15 were positive, 42 were negative, and 27 were indeterminate after central review. The WSIs generated on average 141,950 tiles each. Cytologists using the AI evaluated 10.5 tiles per WSI before making an interpretation. Additionally, cytologists required an average of 84.1 s of total WSI evaluation. WSI interpretation accuracies for CADx (0.754; 95% CI, 0.622-0.859), CADe (0.807; 95% CI, 0.750-0.856), and OCI (0.807; 95% CI, 0.671-0.900) were similar. CONCLUSIONS: This trial demonstrates that an AI application allows cytologists to perform a triaged review of WSIs while maintaining accuracy.

2.
J Med Internet Res ; 26: e56119, 2024 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-39208412

RESUMO

BACKGROUND: Individuals living with a partner with an alcohol use disorder (AUD) can experience significant psychological distress and use health care more than those without a partner with an AUD. However, the prevailing treatment system's focus on the partner and personal barriers limit these individuals from getting help for themselves. Preliminary work on a self-directed, web-based coping skills training program, Stop Spinning My Wheels (SSMW), shows promise in broadening available treatments for this population. In this study, we conducted a robust evaluation of SSMW primary outcomes. OBJECTIVE: The study aims to test whether women with a partner with an AUD assigned to SSMW experienced a greater reduction in negative affect (depression and anger) (1) than a usual web care (UWC) control and (2) with brief phone coach support (SSMW+coach) rather than without (SSMW only) and (3) whether baseline negative affect moderated treatment effects. METHODS: Women (mean age 45.7, SD 10.8 years; Black: 17/456, 3.7%; White: 408/456, 89.5%) were randomized to SSMW only, SSMW+coach, or UWC. Depression (Beck Depression Inventory-II) and anger (State-Trait Anger Expression Inventory 2-State Anger) were assessed at baseline, 12-week posttest, and 6- and 12-month follow-ups. RESULTS: Participants in all conditions decreased in depression from baseline to posttest and from baseline to follow-up; SSMW-only and SSMW+coach participants decreased in anger, but UWC participants did not. Compared to UWC participants, SSMW-only participants experienced greater anger reduction (P=.03), and SSMW+coach participants experienced a greater reduction in depression (P<.001) from baseline to posttest. However, from baseline to follow-up, only a greater, but not statistically significant (P=.052), reduction in anger occurred in SSMW+coach compared to UWC. Although the SSMW conditions did not differ from each other in negative affect outcomes (P=.06-.57), SSMW+coach had higher program engagement and satisfaction (all P<.004). Baseline negative affect did not moderate effects, although remission from baseline clinically relevant depressive symptoms (Beck Depression Inventory≥14) was higher in SSMW only (33/67, 49%; odds ratio 2.13, 95% CI 1.05-4.30; P=.03) and SSMW+coach (46/74, 62%; odds ratio 3.60, 95% CI 1.79-7.23; P<.001) than in UWC (21/67, 31%); remission rates did not differ between the SSMW conditions (P=.12). CONCLUSIONS: The results partially supported the hypotheses. The SSMW conditions had earlier effects than UWC, but positive change in UWC mitigated the hypothesized long-term SSMW-UWC differences. The results highlight the importance of incorporating active controls in web-based clinical trials. Although SSMW+coach showed benefits over SSMW only on engagement and satisfaction measures and in the number needed to treat (5.6 for SSMW only; 3.2 for SSMW+coach), the SSMW conditions were comparable and superior to UWC on depressive symptom remission levels. Overall, SSMW with or without a coach can reduce clinically meaningful distress and add to available treatment options for this large, underserved group. TRIAL REGISTRATION: ClinicalTrials.gov NCT02984241; https://www.clinicaltrials.gov/study/NCT02984241.


Assuntos
Adaptação Psicológica , Alcoolismo , Humanos , Feminino , Pessoa de Meia-Idade , Adulto , Alcoolismo/psicologia , Alcoolismo/terapia , Internet , Depressão/terapia , Depressão/psicologia , Intervenção Baseada em Internet , Ira , Tutoria/métodos , Masculino , Capacidades de Enfrentamento
3.
Chem Sci ; 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39211740

RESUMO

Triptycene derivatives are used extensively in supramolecular and materials chemistry, however, most are prepared using a multi-step synthesis involving the generation of a benzyne intermediate, which hinders production on a large scale. Inspired by the ease of the synthesis of resorcinarenes, we report the rapid and efficient preparation of triptycene-like 1,6,2',7'-tetrahydroxynaphthopleiadene directly from 2,7-dihydroxynaphthalene and phthalaldehyde. Structural characterisation confirms the novel bridged bicyclic framework, within which the planes of the single benzene ring and two naphthalene units are fixed at an angle of ∼120° relative to each other. Other combinations of aromatic 1,2-dialdehydes and 2,7-disubstituted naphthalenes also provided similar triptycene-like products. The low cost of the precursors and undemanding reaction conditions allow for rapid multigram synthesis of 1,6,2',7'-tetrahydroxynaphthopleiadene, which is shown to be a useful precursor for making the parent naphthopleiadene hydrocarbon. The great potential for the use of the naphthopleiadene scaffold in supramolecular and polymer chemistry is demonstrated by the preparation of a rigid novel cavitand, a microporous network polymer, and a solution-processable polymer of intrinsic microporosity.

4.
J Am Geriatr Soc ; 2024 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-39151092

RESUMO

BACKGROUND: Most falls among community-dwelling older adults are due to a loss of balance (LOB) after tripping or slipping. Unfortunately, limited insight is available on the detailed circumstances and context of these LOBs. Moreover, commonly used methods to collect this information is susceptible to limitations of memory recall. The goal of this pilot observational study was to explore the circumstances and context of self-reported LOBs captured by wrist-worn voice recorders among community-dwelling older adults. METHODS: In this pilot observational cohort study, 30 community-dwelling adults with a mean (SD) age of 71.8 (4.4) years were asked to wear a voice recorder on their wrist daily for 3 weeks. Following any naturally-occurring LOB, participants were asked to record their verbal responses to six questions regarding the circumstances and context of each LOB abbreviated with the mnemonic 4WHO: When, Where, What, Why, How, and Outcome. RESULTS: Participants wore the voice recorder 10.9 (0.6) hours per day for 20.7 (0.5) days. One hundred seventy-five voice recordings were collected, with 122 meeting our definition of a LOB. Each participant reported 0-23 LOBs over the 3 weeks or 1.4 (2.1) per participant per week. Across all participants, LOBs were most commonly reported 3 p.m. or later (42%), inside the home (39%), while walking (33%), resulting from a trip (54%), and having induced a stepping response to regain balance (48%). No LOBs resulted in a fall. CONCLUSIONS: Among community-dwelling older adults, wrist-worn voice recorders capture the circumstances and context of LOBs thereby facilitating the documentation of detail of LOBs and potentially falls, without reliance on later recall.

6.
Gastrointest Endosc ; 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39115496

RESUMO

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy (ASGE) provides an evidence-based approach for the role of endoscopy in the management of chronic pancreatitis (CP). This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework. The guideline addresses effectiveness of endoscopic therapies for the management of pain in CP, including celiac plexus block, endoscopic management of pancreatic duct (PD) stones and strictures, and adverse events such as benign biliary strictures (BBSs) and pseudocysts. In patients with painful CP and an obstructed PD, the ASGE suggests surgical evaluation in patients without contraindication to surgery before initiation of endoscopic management. In patients who have contraindications to surgery or who prefer a less-invasive approach, the ASGE suggests an endoscopic approach as the initial treatment over surgery, if complete ductal clearance is likely. When a decision is made to proceed with a celiac plexus block, the ASGE suggests an EUS-guided approach over a percutaneous approach. The ASGE suggests indications for when to consider ERCP alone or with pancreatoscopy and extracorporeal shock wave lithotripsy alone or followed by ERCP for treating obstructing PD stones based on size, location, and radiopacity. For the initial management of PD strictures, the ASGE suggests using a single plastic stent of the largest caliber that is feasible. For symptomatic BBSs caused by CP, the ASGE suggests the use of covered metal stents over multiple plastic stents. For symptomatic pseudocysts, the ASGE suggests endoscopic therapy over surgery. This document clearly outlines the process, analyses, and decision processes used to reach the final recommendations and represents the official ASGE recommendations on the above topics.

7.
J Intensive Care Med ; : 8850666241267262, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39094604

RESUMO

Acute cholecystitis (AC) is associated with significant morbidity and mortality. Minimally invasive laparoscopic cholecystectomy remains the gold standard of treatment. Therapeutic endoscopy for management of AC continues to emerge as a favorable alternative to percutaneous gallbladder drainage in patients with prohibitive operative risk. Endoscopic management of AC includes transpapillary and transmural stenting. When patient-specific factors prevent both surgical and endoscopic treatment, percutaneous cholecystostomy tube (PCT) placement is an option. Early studies show PCT to have worse outcomes when compared against all other described treatment options for the management of AC.

8.
Endocrinology ; 165(9)2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39045670

RESUMO

Classic hereditary hemochromatosis (HH) is an autosomal recessive iron-overload disorder resulting from loss-of-function mutations of the HFE gene. Patients with HH exhibit excessive hepatic iron accumulation that predisposes these patients to liver disease, including the risk for developing liver cancer. Chronic iron overload also poses a risk for the development of metabolic disorders such as obesity, type 2 diabetes, and insulin resistance. We hypothesized that liraglutide, GLP1 receptor agonist, alters iron metabolism while also reducing body weight and glucose tolerance in a mouse model of HH (global HFE knockout, HFE KO) and diet-induced obesity and glucose intolerance. The total body HFE KO and wild-type control mice were fed high-fat diet for 8 weeks. Mice were subdivided into liraglutide and vehicle-treated groups and received daily subcutaneous administration of the respective treatment once daily for 18 weeks. Liraglutide improved glucose tolerance and hepatic lipid markers and reduced body weight in a mouse model of HH, the HFE KO mouse, similar to wild-type controls. Importantly, our data show that liraglutide alters iron metabolism in HFE KO mice, leading to decreased circulating and stored iron levels in HFE KO mice. These observations highlight the potential that GLP1 receptor agonist could be used to reduce iron overload in addition to reducing body weight and improving glucose regulation in HH patients.


Assuntos
Modelos Animais de Doenças , Proteína da Hemocromatose , Hemocromatose , Homeostase , Ferro , Liraglutida , Camundongos Knockout , Animais , Hemocromatose/genética , Hemocromatose/metabolismo , Hemocromatose/tratamento farmacológico , Liraglutida/farmacologia , Liraglutida/uso terapêutico , Ferro/metabolismo , Homeostase/efeitos dos fármacos , Camundongos , Proteína da Hemocromatose/genética , Proteína da Hemocromatose/metabolismo , Fígado/metabolismo , Fígado/efeitos dos fármacos , Masculino , Dieta Hiperlipídica/efeitos adversos , Intolerância à Glucose/metabolismo , Intolerância à Glucose/tratamento farmacológico , Intolerância à Glucose/genética , Obesidade/metabolismo , Obesidade/tratamento farmacológico , Obesidade/genética , Camundongos Endogâmicos C57BL , Peso Corporal/efeitos dos fármacos
9.
Equine Vet J ; 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39023084

RESUMO

BACKGROUND: Fractures of the paracondylar process of the occipital bone may cause headshaking, neck pain and neurologic deficits. The condition is being recognised more frequently with increasing availability of computed tomography. However, to date only limited information is available as to presentation, treatment, surgical approach and outcome. OBJECTIVES: To describe the clinical signs, imaging findings, treatment, surgical approach and outcome in three horses diagnosed with paracondylar process fracture. STUDY DESIGN: Retrospective case series. METHODS: Clinical records and diagnostic images of affected cases were reviewed. RESULTS: Two cases had ventral nonunion fractures-one of these presented with neck pain, headshaking and behavioural changes, while in the other the fracture was a suspected incidental finding in a case of poor performance. A third case with a more dorsal fracture presented with acute facial nerve paralysis. Diagnosis was by computed tomography in all cases, although imaging of ventral fractures by radiography was found to be feasible. Where clinical signs could be associated confidently with the fracture, conservative management resulted in improvement but not complete resolution. Repeated recurrence of clinical signs after prolonged periods of remission necessitated surgical removal in one case, which was readily accomplished with the aid of ultrasound guidance, and led to rapid resolution of clinical signs without significant post-operative complications. The surgical approach is described. MAIN LIMITATIONS: Limited follow-up was available. CONCLUSIONS: Paracondylar process fracture should be considered as a differential diagnosis for headshaking, neck pain, poor performance and facial paresis, and is a justification for performing computed tomography in such cases. A multi-disciplinary approach is beneficial due to the potential for orthopaedic, neurologic, ophthalmologic and behavioural clinical signs, with additional need for expertise in diagnostic imaging and pain management. Surgical fragment removal should be considered for ventral fractures.

10.
ACS Appl Mater Interfaces ; 16(29): 37865-37873, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-38995231

RESUMO

The triphasic interaction of gases with electrode surfaces immersed in aqueous electrolyte is crucial in electrochemical technologies (fuel cells, batteries, sensors). Some microporous materials modify this interaction locally via triphasic storage capacity for gases in aqueous environments linked to changes in apparent oxygen concentration and diffusivity (as well as activity and reactivity). Here, a nanoparticulate polymer of intrinsic microporosity (PIM-1) in aqueous electrolyte is shown to store oxygen gas and thereby enhance electrochemical signals for oxygen reduction in aqueous media. Oxygen reduction current transient data at platinum disk electrodes suggest that the reactivity of ambient oxygen in aqueous electrolyte (typically Doxygen = 2.8 × 10-9 m2 s-1; coxygen = 0.3 mM) is substantially modified (to approximately Dapp,oxygen = 1.6 (±0.3) × 10-12 m2 s-1; capp,oxygen = 50 (±5) mM) with important implications for triphasic electrode processes. The considerable apparent concentration of oxygen even for ambient oxygen levels is important. Potential applications in oxygen sensing, oxygen storage, oxygen catalysis, or applications associated with other types of gases are discussed.

11.
Gastrointest Endosc ; 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39078360

RESUMO

The publisher regrets that this article has been temporarily removed. A replacement will appear as soon as possible in which the reason for the removal of the article will be specified, or the article will be reinstated. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

12.
Soft Matter ; 20(26): 5153-5163, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38895763

RESUMO

Polymers of intrinsic microporosity exhibit a combination of high gas permeability and reasonable permselectivity, which makes them attractive candidates for gas separation membrane materials. The diffusional selective gas transport properties are connected to the molecular mobility of these polymers in the condensed state. Incoherent quasielastic neutron scattering was carried out on two polymers of intrinsic microporosity, PIM-EA-TB(CH3) and its demethylated counterpart PIM-EA-TB(H2), which have high Brunauer-Emmett-Teller surface area values of 1030 m2 g-1 and 836 m2 g-1, respectively. As these two polymers only differ in the presence of two methyl groups at the ethanoanthracene unit, the effect of methyl group rotation can be investigated solely. To cover a broad dynamic range, neutron time-of-flight was combined with neutron backscattering. The demethylated PIM-EA-TB(H2) exhibits a relaxation process with a weak intensity at short times. As the backbone is rigid and stiff this process was assigned to bend-and-flex fluctuations. This process was also observed for the PIM-EA-TB(CH3). A further relaxation process is found for PIM-EA-TB(CH3), which is the methyl group rotation. It was analyzed by a jump-diffusion in a three-fold potential considering also the fact that only a fraction of the present hydrogens in PIM-EA-TB(CH3) participate in the methyl group rotation. This analysis can quantitatively describe the q dependence of the elastic incoherent structure factor. Furthermore, a relaxation time for the methyl group rotation can be extracted. A high activation energy of 35 kJ mol-1 was deduced. This high activation energy evidences a strong hindrance of the methyl group rotation in the bridged PIM-EA-TB(CH3) structure.

13.
JID Innov ; 4(4): 100276, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38827331

RESUMO

In persons with limb loss, prosthetic devices cause skin breakdown, largely because residual limb skin (nonvolar) is not intended to bear weight such as palmoplantar (volar) skin. Before evaluation of treatment efficacy to improve skin resiliency, efforts are needed to establish normative data and assess outcome metric reliability. The purpose of this study was to use optical coherence tomography to (i) characterize volar and nonvolar skin epidermal thickness and (ii) examine the reliability of optical coherence tomography. Four orientations of optical coherence tomography images were collected on 33 volunteers (6 with limb loss) at 2 time points, and the epidermis was traced to quantify thickness by 3 evaluators. Epidermal thickness was greater (P < .01) for volar skin (palm) (265.1 ± 50.9 µm, n = 33) than for both nonvolar locations: posterior thigh (89.8 ± 18.1 µm, n = 27) or residual limb (93.4 ± 27.4 µm, n = 6). The inter-rater intraclass correlation coefficient was high for volar skin (0.887-0.956) but low for nonvolar skin (thigh: 0.292-0.391, residual limb: 0.211-0.580). Correlation improved when comparing only 2 evaluators who used the same display technique (palm: 0.827-0.940, thigh: 0.633-0.877, residual limb: 0.213-0.952). Despite poor inter-rater agreement for nonvolar skin, perhaps due to challenges in identifying the dermal-epidermal junction, this study helps to support the utility of optical coherence tomography to distinguish volar from nonvolar skin.

14.
Evolution ; 78(8): 1441-1452, 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-38736399

RESUMO

Large effect loci often contain genes with critical developmental functions and potentially broad effects across life stages. However, their life stage-specific fitness consequences are rarely explored. In Atlantic salmon, variation in two large-effect loci, six6 and vgll3, is linked to age at maturity and several physiological and behavioral traits in early life. By genotyping the progeny of wild Atlantic salmon that were planted into natural streams with nutrient manipulations, we tested if genetic variation in these loci is associated with survival in early life. We found that higher early-life survival was linked to the genotype associated with late maturation in the vgll3, but with early maturation in the six6 locus. These effects were significant in high nutrients but not in low-nutrient streams. The differences in early survival were not explained by additive genetic effects in the offspring generation but by maternal genotypes in the six6 locus and by both parents' genotypes in the vgll3 locus. Our results suggest that indirect genetic effects of large-effect loci can be significant determinants of offspring fitness. This study demonstrates an intriguing case of how large-effect loci can exhibit complex fitness associations across life stages in the wild and indicates that predicting evolutionary dynamics is difficult.


Assuntos
Genótipo , Salmo salar , Animais , Salmo salar/genética , Feminino , Masculino , Maturidade Sexual/genética , Variação Genética , Aptidão Genética
15.
Semin Nucl Med ; 54(4): 488-496, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38772827

RESUMO

Radioactive iodine (RAI) therapy with iodine-131 is performed in select cases of differentiated thyroid cancer (DTC), typically for remnant ablation, adjuvant therapy, or treatment of known persistent disease. Herein, we review updated RAI dose recommendations and associated risks of secondary primary malignancy (SPM). RAI dose is usually chosen empirically based on the risk assessment of tumor recurrence and other factors. Dose recommendations differ slightly among relevant medical societies. As of April 2024, most medical societies, including the American Thyroid Association (ATA), European Thyroid Association (ETA), Society of Nuclear Medicine and Molecular Imaging/European Association of Nuclear Medicine (SNMMI/ EANM), and National Comprehensive Cancer Network (NCCN), recommend a dose of 1.11 GBq (30 mCi) I-131 for remnant ablation. For adjuvant therapy, the recommended RAI dose ranges from 1.11 to 3.7 GBq (30-100) mCi I-131, although doses up to 5.6 GBq (150 mCi) may also be considered. In patients with known or suspected metastatic disease, at least 3.7 GBq (100 mCi) I-131 should be administered, and RAI doses as high as 7.4 GBq (200 mCi) may be justified depending on the suspected tumor burden and extent. Dosimetry has the advantage of tailoring the RAI dose to each patient's pharmacokinetics, resulting in ≥ 7.4 GBq (200 mCi) of I-131 in most cases. There is an ongoing debate about the risk of developing SPM due to RAI therapy, with several multicenter studies and meta-analyses concerning SPM being published in the last 2 years. The incidence of RAI-associated SPM varies according to the study design and detection method. Several studies showed no increased incidence, and there was no specific secondary cancer or cancer group linked to RAI exposures. Some reports indicated that cumulative RAI doses exceeding 5.6-7.4 GBq (150-200 mCi) were found to represent an increased risk for developing SPM. However, a clearly defined dose threshold cannot be provided based on the current literature. Nonetheless, caution should be exercised when considering repeated RAI therapies for persistent metastatic PTC, with a cumulative dose exceeding 37.0 GBq (1,000 mCi), due to the potential risk of developing SPM and other long-term toxicity. Further research is warranted to understand better the relationship between RAI dose and the risk of SPM.


Assuntos
Radioisótopos do Iodo , Segunda Neoplasia Primária , Neoplasias da Glândula Tireoide , Humanos , Neoplasias da Glândula Tireoide/radioterapia , Neoplasias da Glândula Tireoide/patologia , Radioisótopos do Iodo/uso terapêutico , Segunda Neoplasia Primária/radioterapia , Dosagem Radioterapêutica
17.
bioRxiv ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38798399

RESUMO

Myosin-binding protein H (MyBP-H) is a component of the vertebrate skeletal muscle sarcomere with sequence and domain homology to myosin-binding protein C (MyBP-C). Whereas skeletal muscle isoforms of MyBP-C (fMyBP-C, sMyBP-C) modulate muscle contractility via interactions with actin thin filaments and myosin motors within the muscle sarcomere "C-zone," MyBP-H has no known function. This is in part due to MyBP-H having limited expression in adult fast-twitch muscle and no known involvement in muscle disease. Quantitative proteomics reported here reveal MyBP-H is highly expressed in prenatal rat fast-twitch muscles and larval zebrafish, suggesting a conserved role in muscle development, and promoting studies to define its function. We take advantage of the genetic control of the zebrafish model and a combination of structural, functional, and biophysical techniques to interrogate the role of MyBP-H. Transgenic, FLAG-tagged MyBP-H or fMyBP-C both localize to the C-zones in larval myofibers, whereas genetic depletion of endogenous MyBP-H or fMyBP-C leads to increased accumulation of the other, suggesting competition for C-zone binding sites. Does MyBP-H modulate contractility from the C-zone? Globular domains critical to MyBP-C's modulatory functions are absent from MyBP-H, suggesting MyBP-H may be functionally silent. However, our results suggest an active role. Small angle x-ray diffraction of intact larval tails revealed MyBP-H contributes to the compression of the myofilament lattice accompanying stretch or contraction, while in vitro motility experiments indicate MyBP-H shares MyBP-C's capacity as a molecular "brake". These results provide new insights and raise questions about the role of the C-zone during muscle development.

18.
J Mol Cell Cardiol ; 191: 27-39, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38648963

RESUMO

Approximately 40% of hypertrophic cardiomyopathy (HCM) mutations are linked to the sarcomere protein cardiac myosin binding protein-C (cMyBP-C). These mutations are either classified as missense mutations or truncation mutations. One mutation whose nature has been inconsistently reported in the literature is the MYBPC3-c.772G > A mutation. Using patient-derived human induced pluripotent stem cells differentiated to cardiomyocytes (hiPSC-CMs), we have performed a mechanistic study of the structure-function relationship for this MYBPC3-c.772G > A mutation versus a mutation corrected, isogenic cell line. Our results confirm that this mutation leads to exon skipping and mRNA truncation that ultimately suggests ∼20% less cMyBP-C protein (i.e., haploinsufficiency). This, in turn, results in increased myosin recruitment and accelerated myofibril cycling kinetics. Our mechanistic studies suggest that faster ADP release from myosin is a primary cause of accelerated myofibril cross-bridge cycling due to this mutation. Additionally, the reduction in force generating heads expected from faster ADP release during isometric contractions is outweighed by a cMyBP-C phosphorylation mediated increase in myosin recruitment that leads to a net increase of myofibril force, primarily at submaximal calcium activations. These results match well with our previous report on contractile properties from myectomy samples of the patients from whom the hiPSC-CMs were generated, demonstrating that these cell lines are a good model to study this pathological mutation and extends our understanding of the mechanisms of altered contractile properties of this HCM MYBPC3-c.772G > A mutation.


Assuntos
Cardiomiopatia Hipertrófica , Proteínas de Transporte , Haploinsuficiência , Células-Tronco Pluripotentes Induzidas , Mutação , Miócitos Cardíacos , Humanos , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Miosinas/metabolismo , Miosinas/genética , Diferenciação Celular/genética , Cinética
19.
J Exp Biol ; 227(Suppl_1)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38449324

RESUMO

Developmental plasticity -- the capacity for a genotype to develop into different phenotypes, depending on the environment - is typically viewed from the perspective of the resulting phenotype. Thus, if development is viewed as a trajectory towards a target, then developmental plasticity allows environmentally induced alterations to the target. However, there can also be variations in the trajectory. This is seen with compensatory responses, for instance where growth accelerates after an earlier period of food shortage, or where investment in sexual ornaments is maintained even when resources are limiting. If the compensation is complete, the adult phenotype can appear 'normal' (i.e. the different developmental trajectories converge on the same target). However, alternative trajectories to a common target can have multiple long-term consequences, including altered physiological programming and rates of senescence, possibly owing to trade-offs between allocating resources to the prioritized trait versus to body maintenance. This suggests that plasticity in developmental trajectories towards a common target leads to variation in the resilience and robustness of the adult body. This form of developmental plasticity is far more hidden than plasticity in final adult target, but it may be more common. Here, I discuss the causes, consequences and limitations of these different kinds of plasticity, with a special focus on whether they are likely to be adaptive. I emphasize the need to study plasticity in developmental trajectories, and conclude with suggestions for future research to tease apart the different forms of developmental plasticity and the factors that influence their evolution and expression.


Assuntos
Adaptação Fisiológica , Adulto , Humanos , Genótipo , Fenótipo
20.
Ann Palliat Med ; 13(2): 344-354, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38373778

RESUMO

Hepatocellular carcinoma (HCC) is a common malignancy with many patients presenting with local disease. As of date, the use of radiation is not included in the commonly utilized Barcelona Clinic Liver Cancer (BCLC) classification but is in the National Comprehensive Cancer Network guidelines. Radiation can volumetrically cover the entire tumor and with novel technologic advances can be administered non-invasively with excellent clinical outcomes with few adverse events. The gold standard for localized early HCC (such as BCLC-A) is resection or transplantation. In patients who are not candidates for surgical treatment, locoregional therapy should be considered as an optimal therapy for these patients. Tumor ablation techniques such as microwave ablation (MWA) and radiofrequency ablation (RFA) are excellent tools to control local disease or bridge to transplantation. Should these not be possible though then ablation with external beam radiation is also capable of yielding comparable local control and serve as a bridge to transplant without worse rates of adverse events. For tumors that meet Milan criteria for transplantation, in comparison to transarterial chemoembolization (TACE), there is considerable randomized evidence demonstrating better local control, less adverse events, better progression-free survival (PFS), and less costly. It can be utilized as a bridge in Barcelona liver class B. For larger localized tumors though (extrahepatic disease or vascular invasion like BCLC-C), stereotactic body radiation therapy (SBRT) is shown via a randomized clinical trial to have a survival benefit, local control benefit, and no worse adverse events compared to systemic therapy. In this setting, it should be considered the local consolidation standard of care.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/radioterapia , Carcinoma Hepatocelular/cirurgia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/patologia , Estadiamento de Neoplasias , Estudos Retrospectivos , Quimioembolização Terapêutica/métodos , Resultado do Tratamento
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