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1.
J Cell Sci ; 137(12)2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38832512

RESUMO

As cells migrate through biological tissues, they must frequently squeeze through micron-sized constrictions in the form of interstitial pores between extracellular matrix fibers and/or other cells. Although it is now well recognized that such confined migration is limited by the nucleus, which is the largest and stiffest organelle, it remains incompletely understood how cells apply sufficient force to move their nucleus through small constrictions. Here, we report a mechanism by which contraction of the cell rear cortex pushes the nucleus forward to mediate nuclear transit through constrictions. Laser ablation of the rear cortex reveals that pushing forces behind the nucleus are the result of increased intracellular pressure in the rear compartment of the cell. The pushing forces behind the nucleus depend on accumulation of actomyosin in the rear cortex and require Rho kinase (ROCK) activity. Collectively, our results suggest a mechanism by which cells generate elevated intracellular pressure in the posterior compartment to facilitate nuclear transit through three-dimensional (3D) constrictions. This mechanism might supplement or even substitute for other mechanisms supporting nuclear transit, ensuring robust cell migrations in confined 3D environments.


Assuntos
Movimento Celular , Núcleo Celular , Núcleo Celular/metabolismo , Movimento Celular/fisiologia , Humanos , Actomiosina/metabolismo , Quinases Associadas a rho/metabolismo , Animais , Pressão , Camundongos
2.
Annu Rev Biomed Eng ; 26(1): 93-118, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38316064

RESUMO

Cell traction force plays a critical role in directing cellular functions, such as proliferation, migration, and differentiation. Current understanding of cell traction force is largely derived from 2D measurements where cells are plated on 2D substrates. However, 2D measurements do not recapitulate a vital aspect of living systems; that is, cells actively remodel their surrounding extracellular matrix (ECM), and the remodeled ECM, in return, can have a profound impact on cell phenotype and traction force generation. This reciprocal adaptivity of living systems is encoded in the material properties of biological gels. In this review, we summarize recent progress in measuring cell traction force for cells embedded within 3D biological gels, with an emphasis on cell-ECM cross talk. We also provide perspectives on tools and techniques that could be adapted to measure cell traction force in complex biochemical and biophysical environments.


Assuntos
Matriz Extracelular , Esferoides Celulares , Humanos , Matriz Extracelular/metabolismo , Esferoides Celulares/citologia , Animais , Movimento Celular , Géis/química , Adesão Celular , Microscopia de Força Atômica/métodos , Análise de Célula Única/métodos , Hidrogéis/química
3.
Exp Cell Res ; 410(2): 112939, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34813733

RESUMO

One of the hallmarks of cancer cells is their exceptional ability to migrate within the extracellular matrix (ECM) for gaining access to the circulatory system, a critical step of cancer metastasis. RhoA, a small GTPase, is known to be a key molecular switch that toggles between actomyosin contractility and lamellipodial protrusion during cell migration. Current understanding of RhoA activity in cell migration has been largely derived from studies of cells plated on a two-dimensional (2D) substrate using a FRET biosensor. There has been increasing evidence that cells behave differently in a more physiologically relevant three-dimensional (3D) environment. However, studies of RhoA activities in 3D have been hindered by low signal-to-noise ratio in fluorescence imaging. In this paper, we present a a machine learning-assisted FRET technique to follow the spatiotemporal dynamics of RhoA activities of single breast tumor cells (MDA-MB-231) migrating in a 3D as well as a 2D environment. We found that RhoA activity is more polarized along the long axis of the cell for single cells migrating on 2D fibronectin-coated glass versus those embedded in 3D collagen matrices. In particular, RhoA activities of cells in 2D exhibit a distinct front-to-back and back-to-front movement during migration in contrast to those in 3D. Finally, regardless of dimensionality, RhoA polarization is found to be moderately correlated with cell shape.


Assuntos
Neoplasias da Mama/metabolismo , Transferência Ressonante de Energia de Fluorescência , Aprendizado de Máquina , Proteína rhoA de Ligação ao GTP/metabolismo , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular , Polaridade Celular , Forma Celular , Colágeno/metabolismo , Feminino , Humanos , Ratos , Fatores de Tempo
4.
Eye Contact Lens ; 48(11): 485-488, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35916554

RESUMO

ABSTRACT: This case reports on the use of wavefront-guided (wfg) optics on custom ocular impression-based scleral lenses (IBSLs) for visual improvement in a patient with keratoconus (KC). A 28-year-old man with KC, who had previously failed a traditional, diagnostically fit scleral lens (tSL), was fit with IBSLs with traditional optics. Using a system that included a dot matrix on the IBSL and a wavefront aberrometer with pupil and dot registration software, a wfgIBSL was created. When compared with the IBSL, the wfgIBSL reduced the total higher-order root mean square (HORMS) 67% and 64% in the right and left eye, respectively, resulting in a 2-line improvement in best-contact lens visual acuity (BCLVA) for both eyes. This case demonstrates the successful creation and application of a wfgIBSL resulting in a stable lens, a reduction in HORMS, and an improvement in BCLVA, after failure with a diagnostically fit tSL.


Assuntos
Lentes de Contato , Ceratocone , Cristalino , Masculino , Humanos , Adulto , Ceratocone/complicações , Ceratocone/terapia , Esclera , Acuidade Visual
5.
Am J Otolaryngol ; 42(1): 102834, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33229129

RESUMO

PURPOSE: Near infrared spectroscopy (NIRS) measures tissue oximetry and perfusion of free tissue transfer with the advantage of remote wireless monitoring for free tissue transfer. It has been widely used in breast and extremity reconstruction but has had limited adoption in the head and neck. MATERIALS AND METHODS: A retrospective review of head and neck microvascular reconstruction by three different surgical services over 15 months at one tertiary care hospital was performed. Demographics, flap type, monitoring technique, complications, and flap outcomes were recorded. Monitoring techniques were (1) implantable/handheld Doppler or (2) NIRS. Flap monitoring outcomes were evaluated using multivariate analysis. RESULTS: 119 flaps were performed by four surgeons with a success rate of 92% (109/119). Flaps were monitored with Doppler (40%) or NIRS (60%). There was no difference in flap success based on monitoring technique. An ROC analysis identified that the optimal cutoff in immediate StO2 for classifying flap success at discharge was 68%. CONCLUSIONS: NIRS was successfully implemented in a high-volume head and neck reconstructive practice. NIRS remote monitoring allowed for flap surveillance without requiring in-hospital presence and was able to identify both arterial and venous compromise.


Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Microvasos/cirurgia , Monitorização Fisiológica/métodos , Oximetria/métodos , Perfusão/métodos , Procedimentos de Cirurgia Plástica/métodos , Tecnologia de Sensoriamento Remoto/métodos , Espectroscopia de Luz Próxima ao Infravermelho , Retalhos Cirúrgicos/fisiologia , Retalhos Cirúrgicos/transplante , Procedimentos Cirúrgicos Vasculares/métodos , Idoso , Feminino , Neoplasias de Cabeça e Pescoço/irrigação sanguínea , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
6.
Neuroimage ; 170: 68-82, 2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-28739120

RESUMO

Moving from group level to individual level functional parcellation maps is a critical step for developing a rich understanding of the links between individual variation in functional network architecture and cognitive and clinical phenotypes. Still, the identification of functional units in the brain based on intrinsic functional connectivity and its dynamic variations between and within subjects remains challenging. Recently, the bootstrap analysis of stable clusters (BASC) framework was developed to quantify the stability of functional brain networks both across and within subjects. This multi-level approach utilizes bootstrap resampling for both individual and group-level clustering to delineate functional units based on their consistency across and within subjects, while providing a measure of their stability. Here, we optimized the BASC framework for functional parcellation of the basal ganglia by investigating a variety of clustering algorithms and similarity measures. Reproducibility and test-retest reliability were computed to validate this analytic framework as a tool to describe inter-individual differences in the stability of functional networks. The functional parcellation revealed by stable clusters replicated previous divisions found in the basal ganglia based on intrinsic functional connectivity. While we found moderate to high reproducibility, test-retest reliability was high at the boundaries of the functional units as well as within their cores. This is interesting because the boundaries between functional networks have been shown to explain most individual phenotypic variability. The current study provides evidence for the consistency of the parcellation of the basal ganglia, and provides the first group level parcellation built from individual-level cluster solutions. These novel results demonstrate the utility of BASC for quantifying inter-individual differences in the functional organization of brain regions, and encourage usage in future studies.


Assuntos
Gânglios da Base/diagnóstico por imagem , Gânglios da Base/fisiologia , Mapeamento Encefálico/métodos , Individualidade , Imageamento por Ressonância Magnética/métodos , Adulto , Mapeamento Encefálico/normas , Feminino , Humanos , Imageamento por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Adulto Jovem
7.
Nat Commun ; 15(1): 2766, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553465

RESUMO

Cell migration is critical for tissue development and regeneration but requires extracellular environments that are conducive to motion. Cells may actively generate migratory routes in vivo by degrading or remodeling their environments or instead utilize existing extracellular matrix microstructures or microtracks as innate pathways for migration. While hydrogels in general are valuable tools for probing the extracellular regulators of 3-dimensional migration, few recapitulate these natural migration paths. Here, we develop a biopolymer-based bicontinuous hydrogel system that comprises a covalent hydrogel of enzymatically crosslinked gelatin and a physical hydrogel of guest and host moieties bonded to hyaluronic acid. Bicontinuous hydrogels form through controlled solution immiscibility, and their continuous subdomains and high micro-interfacial surface area enable rapid 3D migration, particularly when compared to homogeneous hydrogels. Migratory behavior is mesenchymal in nature and regulated by biochemical and biophysical signals from the hydrogel, which is shown across various cell types and physiologically relevant contexts (e.g., cell spheroids, ex vivo tissues, in vivo tissues). Our findings introduce a design that leverages important local interfaces to guide rapid cell migration.


Assuntos
Matriz Extracelular , Hidrogéis , Hidrogéis/química , Movimento Celular , Matriz Extracelular/metabolismo , Esferoides Celulares , Biopolímeros/metabolismo
8.
JACC Adv ; 3(2): 100804, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38939377

RESUMO

Background: Vitamin D deficiency (VDD) is associated with coronary heart disease (CHD) and poor outcomes, but supplementation does not improve prognosis. VDD has been implicated in and may promote greater risk through inflammation and impaired progenitor cell function. Objectives: The authors examined VDD, high-sensitivity C-reactive protein (hsCRP), circulating progenitor cell (CPC) counts, and outcomes in patients with CHD. They hypothesized that the higher risk with VDD is mediated by inflammation and impaired regenerative capacity. Methods: A total of 5,452 individuals with CHD in the Emory Cardiovascular Biobank had measurement of 25-hydroxyvitamin D, subsets of whom had hsCRP measurements and CPCs estimated as CD34-expressing mononuclear cell counts. Findings were validated in an independent cohort. 25-hydroxyvitamin D <20 ng/mL was considered VDD. Cox and Fine-Gray models determined associations between marker levels and: 1) all-cause mortality; 2) cardiovascular mortality; and 3) major adverse cardiovascular events, a composite of adverse CHD outcomes. Results: VDD (43.6% of individuals) was associated with higher adjusted cardiovascular mortality (HR: 1.57, 95% CI: 1.09-2.28). There were significant interactions between VDD and hsCRP and CPC counts in predicting cardiovascular mortality. Individuals with both VDD and elevated hsCRP had the greatest risk (HR: 2.82, 95% CI: 2.16-3.67). Only individuals with both VDD and low CPC counts were at high risk (HR: 2.25, 95% CI: 1.46-3.46). These findings were reproduced in the validation cohort. Conclusions: VDD predicts adverse outcomes in CHD. Those with VDD, inflammation and/or diminished regenerative capacity are at a significantly greater risk of cardiovascular mortality. Whether targeted supplementation in these high-risk groups improves risk warrants further study.

9.
Neuroimage ; 76: 183-201, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23499792

RESUMO

Functional connectomics is one of the most rapidly expanding areas of neuroimaging research. Yet, concerns remain regarding the use of resting-state fMRI (R-fMRI) to characterize inter-individual variation in the functional connectome. In particular, recent findings that "micro" head movements can introduce artifactual inter-individual and group-related differences in R-fMRI metrics have raised concerns. Here, we first build on prior demonstrations of regional variation in the magnitude of framewise displacements associated with a given head movement, by providing a comprehensive voxel-based examination of the impact of motion on the BOLD signal (i.e., motion-BOLD relationships). Positive motion-BOLD relationships were detected in primary and supplementary motor areas, particularly in low motion datasets. Negative motion-BOLD relationships were most prominent in prefrontal regions, and expanded throughout the brain in high motion datasets (e.g., children). Scrubbing of volumes with FD>0.2 effectively removed negative but not positive correlations; these findings suggest that positive relationships may reflect neural origins of motion while negative relationships are likely to originate from motion artifact. We also examined the ability of motion correction strategies to eliminate artifactual differences related to motion among individuals and between groups for a broad array of voxel-wise R-fMRI metrics. Residual relationships between motion and the examined R-fMRI metrics remained for all correction approaches, underscoring the need to covary motion effects at the group-level. Notably, global signal regression reduced relationships between motion and inter-individual differences in correlation-based R-fMRI metrics; Z-standardization (mean-centering and variance normalization) of subject-level maps for R-fMRI metrics prior to group-level analyses demonstrated similar advantages. Finally, our test-retest (TRT) analyses revealed significant motion effects on TRT reliability for R-fMRI metrics. Generally, motion compromised reliability of R-fMRI metrics, with the exception of those based on frequency characteristics - particularly, amplitude of low frequency fluctuations (ALFF). The implications of our findings for decision-making regarding the assessment and correction of motion are discussed, as are insights into potential differences among volume-based metrics of motion.


Assuntos
Artefatos , Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Conectoma/métodos , Vias Neurais/fisiologia , Movimentos da Cabeça , Humanos , Processamento de Imagem Assistida por Computador/métodos , Movimento (Física) , Descanso/fisiologia
10.
J Clin Med ; 12(10)2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-37240523

RESUMO

Dyslipidemia is a treatable risk factor for atherosclerotic cardiovascular disease that can be addressed through lifestyle changes and/or lipid-lowering therapies. Adherence to statins can be a clinical challenge in some patients due to statin-associated muscle symptoms and other side effects. There is a growing interest in integrative cardiology and nutraceuticals in the management of dyslipidemia, as some patients desire or are actively seeking a more natural approach. These agents have been used in patients with and without established atherosclerotic cardiovascular disease. We provide an updated review of the evidence on many new and emerging nutraceuticals. We describe the mechanism of action, lipid-lowering effects, and side effects of many nutraceuticals, including red yeast rice, bergamot and others.

11.
bioRxiv ; 2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37961689

RESUMO

Mechanical properties of the extracellular matrices (ECMs) critically regulate a number of important cell function including growth, differentiation and migration. Type I collagen and glycosaminoglycans (GAGs) are two primary components of ECMs that contribute to tissue mechanics with the collagen fiber network sustaining tension and GAGs withstanding compression. Collagen stiffness as well as its architecture are known to be important role players in cell-ECM mechanical interactions, however, much less is known about how GAGs within ECMs regulate cell force generation and invasion. Inspired by a recent theoretical work from the Shenoy lab that GAGs play important roles in cell - ECM interactions, we hereby present experimental studies on the role of hyaluronic acid (HA, an unsulfated GAG) in single tumor cell traction force generation within HA collagen cogels using a recently developed 3D cell traction force microscopy. Our work revealed that CD44, a cell surface adhesion receptor to HA, was engaged in cell traction force generation in conjunction with ß1-integrin. Furthermore, we found that HA significantly modified the architecture and mechanics of the collagen fiber network, decreased tumor cells' propensity to remodel the collagen network, decreased traction force generation and transmission distance, and attenuated tumor invasion in agreement with theoretical predictions. Our findings highlighted the significance of CD44 and HA engagement in cell-ECM mechanical interactions, providing new insights on the mechanical model of cellular force transmission.

12.
Nat Commun ; 14(1): 4933, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37582834

RESUMO

Although artificial neural networks (ANNs) were inspired by the brain, ANNs exhibit a brittleness not generally observed in human perception. One shortcoming of ANNs is their susceptibility to adversarial perturbations-subtle modulations of natural images that result in changes to classification decisions, such as confidently mislabelling an image of an elephant, initially classified correctly, as a clock. In contrast, a human observer might well dismiss the perturbations as an innocuous imaging artifact. This phenomenon may point to a fundamental difference between human and machine perception, but it drives one to ask whether human sensitivity to adversarial perturbations might be revealed with appropriate behavioral measures. Here, we find that adversarial perturbations that fool ANNs similarly bias human choice. We further show that the effect is more likely driven by higher-order statistics of natural images to which both humans and ANNs are sensitive, rather than by the detailed architecture of the ANN.


Assuntos
Encéfalo , Redes Neurais de Computação , Humanos , Encéfalo/diagnóstico por imagem , Percepção
13.
JAMA Netw Open ; 6(10): e2338060, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37847500

RESUMO

Importance: The clinical significance of hemodynamic reactivity to mental stress in the population with coronary artery disease (CAD) is unclear. Objective: To investigate the association between hemodynamic reactivity to mental stress and the risk of adverse cardiovascular events in patients with stable CAD. Design, Setting, and Participants: This cohort study included individuals with stable CAD from 2 prospective studies from a university-based hospital network: the Mental Stress Ischemia Prognosis Study (MIPS) and the Myocardial Infarction and Mental Stress Study 2 (MIMS2). Participants were enrolled between June 2011 and March 2016 and followed up for a median of 6.0 (IQR, 5.6-6.0) years in MIPS and 4.6 (IQR, 3.8-5.3) years in MIMS2. Data were analyzed from December 1, 2022, to February 15, 2023. Exposures: The rate-pressure product (RPP) was calculated as the mean systolic blood pressure times the mean heart rate at rest. Rate-pressure product reactivity was calculated as the maximum RPP during a standardized mental stress test minus the RPP at rest. Main Outcomes and Measures: The primary outcome was a composite of cardiovascular death or nonfatal myocardial infarction. The secondary end point additionally included hospitalizations for heart failure. Results: From the total of 938 individuals from the pooled cohort (mean [SD] age, 60.2 [10.1] years; 611 [65.1%] men), 631 participated in MIPS and 307 in MIMS2. A total of 373 individuals (39.8%) were Black, 519 (55.3%) were White, and 46 (4.9%) were of unknown race or ethnicity. The RPP increased by a mean (SD) of 77.1% (23.1%) during mental stress (mean [SD] absolute change, 5651 [2878]). For every SD decrease in RPP reactivity with mental stress, the adjusted hazard ratios for the primary and secondary end points were 1.30 (95% CI, 1.04-1.72) and 1.30 (95% CI, 1.06-1.56), respectively, in MIPS and 1.41 (95% CI, 1.06-1.97) and 1.21 (95% CI, 1.02-1.60), respectively, in MIMS2. In the pooled sample, when RPP reactivity to mental stress was added to a model including traditional clinical risk characteristics, model discrimination for adverse events improved (increase in C statistic of 5% for the primary end point; P = .009). Conclusions and Relevance: In this cohort study of individuals with stable CAD, a blunted cardiovascular reactivity to mental stress was associated with adverse outcomes. Future studies are needed to assess the clinical utility of mental stress reactivity testing in this population.


Assuntos
Doença da Artéria Coronariana , Infarto do Miocárdio , Masculino , Humanos , Pessoa de Meia-Idade , Feminino , Estudos de Coortes , Estudos Prospectivos , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/complicações , Hemodinâmica
14.
bioRxiv ; 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37808836

RESUMO

Cell migration is critical for tissue development and regeneration but requires extracellular environments that are conducive to motion. Cells may actively generate migratory routes in vivo by degrading or remodeling their environments or may instead utilize existing ECM microstructures or microtracks as innate pathways for migration. While hydrogels in general are valuable tools for probing the extracellular regulators of 3D migration, few have recapitulated these natural migration paths. Here, we developed a biopolymer-based (i.e., gelatin and hyaluronic acid) bicontinuous hydrogel system formed through controlled solution immiscibility whose continuous subdomains and high micro-interfacial surface area enabled rapid 3D migration, particularly when compared to homogeneous hydrogels. Migratory behavior was mesenchymal in nature and regulated by biochemical and biophysical signals from the hydrogel, which was shown across various cell types and physiologically relevant contexts (e.g., cell spheroids, ex vivo tissues, in vivo tissues). Our findings introduce a new design that leverages important local interfaces to guide rapid cell migration.

15.
Med Res Arch ; 11(4)2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37484871

RESUMO

Objective: Coronary heart disease is a leading cause of death and disability. Although psychological stress has been identified as an important potential contributor, mechanisms by which stress increases risk of heart disease and mortality are not fully understood. The purpose of this study was to assess mechanisms by which stress acts through the brain and heart to confer increased CHD risk. Methods: Coronary Heart Disease patients (N=10) underwent cardiac imaging with [Tc-99m] sestamibi single photon emission tomography at rest and during a public speaking mental stress task. Patients returned for a second day and underwent positron emission tomography imaging of the brain, heart, bone marrow, aorta (indicating inflammation) and subcutaneous adipose tissue, after injection of [18F]2-fluoro-2-deoxyglucose for assessment of glucose uptake followed mental stress. Patients with (N=4) and without (N=6) mental stress-induced myocardial ischemia were compared for glucose uptake in brain, heart, adipose tissue and aorta with mental stress. Results: Patients with mental stress-induced ischemia showed a pattern of increased uptake in the heart, medial prefrontal cortex, and adipose tissue with stress. In the heart disease group as a whole, activity increase with stress in the medial prefrontal brain and amygdala correlated with stress-induced increases in spleen (r=0.69, p=0.038; and r=0.69, p=0.04 respectfully). Stress-induced frontal lobe increased uptake correlated with stress-induced aorta uptake (r=0.71, p=0.016). Activity in insula and medial prefrontal cortex was correlated with post-stress activity in bone marrow and adipose tissue. Activity in other brain areas not implicated in stress did not show similar correlations. Increases in medial prefrontal activity with stress correlated with increased cardiac glucose uptake with stress, suggestive of myocardial ischemia (r=0.85, p=0.004). Conclusions: These findings suggest a link between brain response to stress in key areas mediating emotion and peripheral organs involved in inflammation and hematopoietic activity, as well as myocardial ischemia, in Coronary Heart Disease patients.

16.
IDCases ; 25: e01221, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34295645

RESUMO

Acute suppurative thyroiditis (AST) is a rare infection of the thyroid gland, and most patients are euthyroid upon presentation. We present an interesting case of a 42-year-old man with a history of intravenous drug use (IVDU) and poorly controlled type 2 diabetes mellitus who was admitted for sepsis and thyrotoxicosis from infective endocarditis (IE), AST, prostate abscess, and pyelonephritis. He suffered from a cerebral vascular accident (CVA) from septic embolic showering. Thyroid-stimulating hormone (TSH) was <0.10 mIU/L, and free thyroxine (T4) levels were>90 pmol/L. Methicillin-resistant Staphylococcus aureus (MRSA) was cultured in the patient's blood and urine. He was treated with prompt intravenous (IV) antimicrobials and source control from a transurethral resection of the prostate. This case demonstrates that AST can be a potential complication of IE and IVDU.

17.
Eur J Case Rep Intern Med ; 7(12): 001879, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33312997

RESUMO

BACKGROUND: Paliperidone and mirtazapine are psychotropic agents associated with proarrhythmic effects. CASE PRESENTATION: A 21-year-old woman was admitted to the intensive care unit on two separate occasions for attempting suicide by overdosing on paliperidone and mirtazapine. During both admissions, the patient had atypical chest pain and a first-degree atrioventricular block (AVB) with paradoxical sinus tachycardia, which resolved with the discontinuation of paliperidone and mirtazapine and aggressive intravenous fluids. CONCLUSION: Drug-induced first-degree AVB from paliperidone and mirtazapine should be on the differential diagnosis in patients on paliperidone and/or mirtazapine who present with chest pain, tachycardia or new-onset first-degree AVB. LEARNING POINTS: Paliperidone and mirtazapine are associated with first-degree heart block, which may be a harbinger of torsades de pointes and ventricular fibrillation.Paliperidone and mirtazapine may potentiate each other's proarrhythmic effects since the metabolism of both involve the cytochrome P450 2D6 enzyme.A history of psychiatric illness makes it difficult to rule out atypical chest pain without ECG or troponins and often leads to increased resource utilization, even during times of heavy use like the COVID-19 pandemic.

18.
IDCases ; 20: e00761, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32368492

RESUMO

Borrelia burgdorferi (B. burgdorferi) is a spirochete bacterium that is transmitted via the Ixodes tick. Infection results in Lyme disease with possible cardiac manifestations, which is also known as Lyme carditis. Patients can present with bradycardia due to rapidly fluctuating atrioventricular block (AVB), which is the hallmark of Lyme carditis. However, we present a rare case of sick sinus syndrome (SSS) without AVB in a 47-year-old man with Lyme disease. He initially presented with a headache and subsequently developed new onset bradycardia and a right cranial nerve (CN) VI palsy with diplopia. B. burgdorferi enzyme-linked immunosorbent assay (ELISA) screen and IgM western blot were positive. He was admitted to the intensive care unit. Electrocardiography (EKG) indicated a heart rate in the high 30 s beats per minute (BPM) with several pauses, but no AVB was present. The patient responded well to therapy, and was discharged with an outpatient regimen of doxycycline. Lyme carditis should be considered in patients who develop new onset bradycardia and live in endemic areas.

19.
Eur J Case Rep Intern Med ; 7(10): 001798, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33083358

RESUMO

BACKGROUND: Non-bacterial thrombotic endocarditis (NBTE) is a paraneoplastic phenomenon with sterile vegetations. It is associated with adenocarcinoma and can shower emboli, which can be the presenting symptom. CASE PRESENTATION: A 44-year-old woman with adenocarcinoma of the lung presented with chest pain, left hand weakness, and ataxia due to repeated embolic showering from NBTE to the central nervous system (CNS) and spleen. CONCLUSION: NBTE is a rare condition that should be on the differential diagnosis in patients with culture-negative endocarditis and a history of adenocarcinoma. LEARNING POINTS: Differentiating non-bacterial thrombotic endocarditis (NBTE) from infective endocarditis can be a diagnostic challenge due to slow growing organisms; laboratory findings that suggest NBTE include the lack of leucocytosis, normal C-reactive protein, negative blood culture sets, and positive antiphospholipid antibodies.Serial transesophageal echocardiogram (TEE) should be performed if suspicion of valvular vegetations is high despite the initial TEE showing no vegetations.The mainstay treatment of NBTE is anticoagulation and addressing the underlying condition.

20.
Cureus ; 12(9): e10542, 2020 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-33094081

RESUMO

This report describes a case involving a balloon kyphoplasty bone tamp becoming lodged inside the vertebral body and unable to be withdrawn, the first report of its kind in the literature. A board certified interventional pain management physician was performing a balloon kyphoplasty for an L3 osteoporotic vertebral compression fracture using a bipedicular approach with two bone tamps. Cannulation and cavity formation were completed without complication; however, upon removal of the balloons it was noted that one had become lodged in the vertebral body. Several attempts were made to remove the balloon. Neurosurgery and the balloon manufacturer were consulted intraoperative, and it was decided to leave the balloon fragments in situ and complete the interventional fixation of the vertebral body with bone cement. The patient followed up in the clinic several months later without neurologic complications. Postoperative radiography confirmed the presence of a retained foreign body consistent with balloon fragments. Balloon kyphoplasty and its various procedural complications will be discussed, as well as the intraoperative decision making faced when encountering a complication.

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