Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 43
Filter
1.
JAMA Intern Med ; 184(5): 484-492, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38466302

ABSTRACT

Importance: Chronic kidney disease (CKD) affects 37 million adults in the United States, and for patients with CKD, hypertension is a key risk factor for adverse outcomes, such as kidney failure, cardiovascular events, and death. Objective: To evaluate a computerized clinical decision support (CDS) system for the management of uncontrolled hypertension in patients with CKD. Design, Setting, and Participants: This multiclinic, randomized clinical trial randomized primary care practitioners (PCPs) at a primary care network, including 15 hospital-based, ambulatory, and community health center-based clinics, through a stratified, matched-pair randomization approach February 2021 to February 2022. All adult patients with a visit to a PCP in the last 2 years were eligible and those with evidence of CKD and hypertension were included. Intervention: The intervention consisted of a CDS system based on behavioral economic principles and human-centered design methods that delivered tailored, evidence-based recommendations, including initiation or titration of renin-angiotensin-aldosterone system inhibitors. The patients in the control group received usual care from PCPs with the CDS system operating in silent mode. Main Outcomes and Measures: The primary outcome was the change in mean systolic blood pressure (SBP) between baseline and 180 days compared between groups. The primary analysis was a repeated measures linear mixed model, using SBP at baseline, 90 days, and 180 days in an intention-to-treat repeated measures model to account for missing data. Secondary outcomes included blood pressure (BP) control and outcomes such as percentage of patients who received an action that aligned with the CDS recommendations. Results: The study included 174 PCPs and 2026 patients (mean [SD] age, 75.3 [0.3] years; 1223 [60.4%] female; mean [SD] SBP at baseline, 154.0 [14.3] mm Hg), with 87 PCPs and 1029 patients randomized to the intervention and 87 PCPs and 997 patients randomized to usual care. Overall, 1714 patients (84.6%) were treated for hypertension at baseline. There were 1623 patients (80.1%) with an SBP measurement at 180 days. From the linear mixed model, there was a statistically significant difference in mean SBP change in the intervention group compared with the usual care group (change, -14.6 [95% CI, -13.1 to -16.0] mm Hg vs -11.7 [-10.2 to -13.1] mm Hg; P = .005). There was no difference in the percentage of patients who achieved BP control in the intervention group compared with the control group (50.4% [95% CI, 46.5% to 54.3%] vs 47.1% [95% CI, 43.3% to 51.0%]). More patients received an action aligned with the CDS recommendations in the intervention group than in the usual care group (49.9% [95% CI, 45.1% to 54.8%] vs 34.6% [95% CI, 29.8% to 39.4%]; P < .001). Conclusions and Relevance: These findings suggest that implementing this computerized CDS system could lead to improved management of uncontrolled hypertension and potentially improved clinical outcomes at the population level for patients with CKD. Trial Registration: ClinicalTrials.gov Identifier: NCT03679247.


Subject(s)
Antihypertensive Agents , Decision Support Systems, Clinical , Hypertension , Renal Insufficiency, Chronic , Humans , Female , Male , Hypertension/drug therapy , Hypertension/complications , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/therapy , Antihypertensive Agents/therapeutic use , Aged , Middle Aged , Primary Health Care/methods
2.
J Thorac Imaging ; 2024 Jan 09.
Article in English | MEDLINE | ID: mdl-38193208

ABSTRACT

BACKGROUND: Increased left ventricular wall thickness is a hallmark of cardiac amyloidosis (CA). Several other disease states, including hypertrophic cardiomyopathy (HCM), share this common feature. Myocardial strain has emerged as a diagnostic and prognostic tool to differentiate causes of increased left ventricular wall thickness. We sought to determine if regional strain differences were present in CA when compared with HCM when indexed to wall thickness as well as adjusting for important factors such as ejection fraction (EF), age, sex, and hypertension. METHODS: We performed a multicenter, retrospective analysis of 122 patients in 3 groups: CA (n=40), HCM (n=44), and controls (n=38). Using commercially available software, we determined peak systolic strain measurements in the base, mid, and apical segments in all 3 cardinal directions of radial strain, circumferential strain, and longitudinal strain. The regional strain was indexed to wall thickness to create a strain to wall thickness (STT) ratio. Analysis of Variance was performed to examine the association of each strain parameter with the disease group, adjusting for age, sex, hypertension, and EF. Multinomial logistic regression was performed to determine which combination of variables can potentially be used to best model the disease group. RESULTS: Ratios of STT at all 3 levels were significantly different with respect to the cardinal directions of radial, circumferential, and longitudinal strain in a multivariable analysis adjusting for age, sex, and hypertension. Specifically, with respect to the basal segments, the STT ratio across CA, HCM, and normal were significantly different in radial (1.13±0.34 vs. 3.79±0.22 vs. 4.12±0.38; P<0.0001), circumferential (-0.79±0.10 vs. -1.62±0.07 vs. -2.25±0.11; P<0.0001), and longitudinal directions (-0.41±0.09 vs. -1.03±0.06 vs. -1.41±0.10; P<0.0001). When adjusting for age, sex, hypertension and EF, only the base was significantly different between the CA and HCM groups in the radial (1.49±0.37 vs. 3.53±0.24; P<0.0001), circumferential -1.04±0.10 vs. -1.44±0.06; P<0.005), and longitudinal (-0.55±0.10 vs -0.94±0.06; P=0.007) directions. Using multinomial logistic regression, the use of age, left ventricular EF, global longitudinal strain, and basal radial strain yielded a diagnostic model with an area under the receiver operating characteristic curve (AUC) of 0.98. A model excluding age, despite being likely an independent predictor in our cohort, yielded an overall AUC of 0.90. When excluding age, the overall AUC was 0.91 and specifically when discriminating CA from HCM was 0.95. CONCLUSIONS: Regional myocardial strain indexed to wall thickness with an STT ratio can differentiate between etiologies of increased left ventricular wall thickness. Differences in myocardial deformation may be independent of wall thickness. Differences in basal strain when indexed to wall thickness in all 3 cardinal directions between CA and HCM are independent of EF. Multinomial logistic regression analysis using strain parameters differentiates CA and HCM with excellent diagnostic accuracy.

3.
Am J Cardiol ; 207: 314-321, 2023 11 15.
Article in English | MEDLINE | ID: mdl-37774472

ABSTRACT

Our objective is to use computed tomography angiography (CTA) and computed tomography perfusion (CTP) to identify the ischemic significance of myocardial bridging (MB). We also seek to determine the long-term prognostication of MB in the presence or absence of obstructive coronary artery disease (CAD). The CORE320, a prospective, multicenter study including 381 patients with known or suspected CAD clinically referred for invasive coronary angiography who underwent combined (CTA-CTP) and single-photon emission computed tomography before conventional coronary angiography. The incidence of MB was identified in 135 patients (35.4%) with 93.9% identified in the left anterior descending artery. MB were divided as partially encased versus fully encased. There was no difference in ischemia identified between partially encased MB and fully encased MB (37 [40%] vs 25 [35%], p = 0.54]. Ischemia was identified at similar rates in partially versus fully encased MB by single-photon emission computed tomography at (8 [9%] vs 8 [11%], p = 0.57] and CTP (34 [37%] vs 21 [30%], p = 0.33]. There was no difference in the primary outcome of 5-year outcome of combined incidence of myocardial infarction or death. The restricted mean survival time in patients with CTA with <50% stenosis with or without a MB was 4.906 years (95% confidence interval 4.759 to 5.000) and 4.891 years (95% confidence interval 4.718 to 5.000), respectively (p = 0.824). Cardiac computed tomography perfusion imaging can assess both anatomic and functional significance of myocardial bridging with diagnostic accuracy similar to current standard imaging. Furthermore, 5-year cardiovascular events were not different with the presence of MB in both obstructive and non-obstructive CAD.


Subject(s)
Coronary Artery Disease , Coronary Stenosis , Myocardial Bridging , Myocardial Infarction , Myocardial Perfusion Imaging , Humans , Computed Tomography Angiography , Prospective Studies , Prognosis , Follow-Up Studies , Coronary Artery Disease/diagnostic imaging , Coronary Angiography/methods , Myocardial Perfusion Imaging/methods , Perfusion , Predictive Value of Tests
4.
Appl Clin Inform ; 14(3): 528-537, 2023 05.
Article in English | MEDLINE | ID: mdl-37437601

ABSTRACT

BACKGROUND: Chronic kidney disease (CKD) is common and associated with adverse clinical outcomes. Most care for early CKD is provided in primary care, including hypertension (HTN) management. Computerized clinical decision support (CDS) can improve the quality of care for CKD but can also cause alert fatigue for primary care physicians (PCPs). Computable phenotypes (CPs) are algorithms to identify disease populations using, for example, specific laboratory data criteria. OBJECTIVES: Our objective was to determine the feasibility of implementation of CDS alerts by developing CPs and estimating potential alert burden. METHODS: We utilized clinical guidelines to develop a set of five CPs for patients with stage 3 to 4 CKD, uncontrolled HTN, and indications for initiation or titration of guideline-recommended antihypertensive agents. We then conducted an iterative data analytic process consisting of database queries, data validation, and subject matter expert discussion, to make iterative changes to the CPs. We estimated the potential alert burden to make final decisions about the scope of the CDS alerts. Specifically, the number of times that each alert could fire was limited to once per patient. RESULTS: In our primary care network, there were 239,339 encounters for 105,992 primary care patients between April 1, 2018 and April 1, 2019. Of these patients, 9,081 (8.6%) had stage 3 and 4 CKD. Almost half of the CKD patients, 4,191 patients, also had uncontrolled HTN. The majority of CKD patients were female, elderly, white, and English-speaking. We estimated that 5,369 alerts would fire if alerts were triggered multiple times per patient, with a mean number of alerts shown to each PCP ranging from 0.07-to 0.17 alerts per week. CONCLUSION: Development of CPs and estimation of alert burden allows researchers to iteratively fine-tune CDS prior to implementation. This method of assessment can help organizations balance the tradeoff between standardization of care and alert fatigue.


Subject(s)
Decision Support Systems, Clinical , Female , Male , Animals , Feasibility Studies , Algorithms , Cognition , Phenotype
5.
J Cardiovasc Comput Tomogr ; 17(3): 226-230, 2023.
Article in English | MEDLINE | ID: mdl-37015851

ABSTRACT

BACKGROUND: As cardiovascular computed tomography (CCT) practice evolves, the demand for specialists continues to increase. However, CCT training remains variable globally with limited contemporaneous data to understand this heterogeneity. We sought to understand the role of CCT globally and the training available to underpin its use. METHODS: We performed two consecutive surveys of cardiology and radiology physicians, two years apart, utilizing the Society of Cardiovascular Computed Tomography (SCCT) website, weblinks, social media platforms, and meeting handouts to maximize our response rate. We compared United States (US)-based vs. international responses to understand global similarities and differences in practice and training in the surveys. RESULTS: 235 respondents (37% trainees and 63% educators/non-trainees) initiated the first survey with 174 (74%) completing the core survey, with 205 providing their work location (114 US and 91 international). Eighty-four percent (92/110) of educator respondents stated a need for increased training opportunities to meet growing demand. Dedicated training fellowships are heterogenous, with limited access to structural heart imaging training, despite structural scanning being performed within institutions. The lack of a standardized curriculum was identified as the main obstacle to effective CCT learning, particularly in the US, with web-based learning platforms being the most popular option for improving access to CCT training. 148 trainees initiated the second survey with 107 (72%) completing the core components (51% North America, 49% international). Only 68% said they would be able to meet their required CCT education needs via their training program. Obstacles in obtaining CCT training again included a lack of a developed curriculum (51%), a lack of dedicated training time (35%), and a lack of local faculty expertise (31%). There was regional variability in access to CCT training, and, in contrast to the first survey, most (89%) felt 1:1 live review of cases with trained/expert reader was most useful for improving CCT training alongside formal curriculum/live lectures (72%). CONCLUSIONS: There is a need to expand dedicated CCT training globally to meet the demand for complex CCT practice. Access to CCT education (didactic and 1:1 case-based teaching from expert faculty), implementation of recently published global training curricula, and increased teaching resources (web-based) as an adjunct to existing experiential learning opportunities, are all deemed necessary to address current educational shortfalls.


Subject(s)
Cardiology , Curriculum , Humans , United States , Predictive Value of Tests , Surveys and Questionnaires , Tomography, X-Ray Computed
6.
Ann Otol Rhinol Laryngol ; 132(10): 1233-1248, 2023 Oct.
Article in English | MEDLINE | ID: mdl-36582148

ABSTRACT

OBJECTIVES: Endovascular embolization has emerged as an effective treatment for intractable epistaxis. This systematic review and meta-analysis aimed to calculate the rates of success, rebleeds, and complications and to identify the etiologies and complications of patients who undergo endovascular embolization. METHODS: This systematic review and meta-analysis was conducted per the guidelines set forth by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Articles were extracted from Scopus, PubMed, Web of Science, and Cochrane Central and were filtered by a systematic review process using Rayyan software. A random-effects model was used to quantify the rates success, rebleeds, and complications. RESULTS: Forty-two studies were included, totaling 1660 patients. The pooled success rate was 89% (95% confidence interval [CI] 86%-92%) and the pooled rebleed rate was 19% (95% CI 16%-22%). The pooled minor complication rate was 18% (95% CI 11%-27%). The most common major complication was soft tissue necrosis followed by stroke. The most common minor complication was facial pain. No minor complications were reported to be permanent. Of the patients who failed initial embolization, 42% underwent repeat embolization and 34% underwent surgical arterial ligation. CONCLUSIONS: Endovascular embolization is an effective treatment for intractable epistaxis. The decision to perform embolization should be carefully weighed given the rare but significant major complications.


Subject(s)
Embolization, Therapeutic , Epistaxis , Humans , Epistaxis/etiology , Epistaxis/therapy , Treatment Outcome , Embolization, Therapeutic/adverse effects , Ligation/adverse effects
7.
J Interv Card Electrophysiol ; 66(5): 1113-1117, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36155878

ABSTRACT

BACKGROUND: Left bundle branch pacing (LBBP) is a developing method of native conduction pacing, but cases of injury to the septal perforator arteries during implantation have been reported. Knowing the distance between the His bundle and the first septal perforator artery can help operators implant LBBP leads more safely. METHODS: Using previously performed coronary CT angiography (CCTA) studies, the distance between the His bundle and the first septal perforator was measured. RESULTS: A total of 50 CCTA studies were included. The mean distance from the His bundle to the first septal perforator (His-SP) along the line connecting the His bundle to the RV apex (His-RV apex) was 27.17 ± 7.7 mm with a range of 13.0 to 44.7 mm. The distance was greater than 2.0 cm in 84% of patients. To standardize this distance among patients with varying cardiac structures, the ratio between the His-SP distance and the His-RV Apex distance was also measured. The mean His-SP:His-RV Apex was 0.302 and the median was 0.298. Eighty-six percent of patients had a ratio of greater than 0.20. CONCLUSION: Using this information, operators can aim to implant LBBP leads within 2.0 cm of the His bundle or 20% of the distance between the His bundle and the RV apex with minimal risk of causing vascular injury.


Subject(s)
Bundle of His , Bundle-Branch Block , Humans , Bundle of His/diagnostic imaging , Bundle-Branch Block/diagnostic imaging , Bundle-Branch Block/therapy , Cardiac Pacing, Artificial/methods , Electrocardiography/methods , Heart Conduction System
8.
J Pediatr Hematol Oncol ; 45(1): e52-e55, 2023 01 01.
Article in English | MEDLINE | ID: mdl-35972831

ABSTRACT

Glutamine (Gln) was FDA-approved in 2017 to reduce acute sickle cell disease (SCD) pain and acute chest syndrome. However, typical pediatric patients with SCD exhibit moderate adherence, measured by a medication possession ratio <80%. This study examined Gln utilization in a "real-world" clinical setting to determine factors influencing medication adherence and to characterize the impact of an interdisciplinary team approach at an institution with specialty pharmacy services. A retrospective chart review identified 40 patients prescribed Gln by sickle cell specialists over a 2-year period and met selection criteria. Gln medication possession ratio for pediatric (72%) and adult (76%) patients were higher than other SCD medications. Pediatric patients (74%) demonstrated significantly lower first-attempt insurance approval rate compared with adult patients (95%) ( P =0.0026), suggesting an initial access barrier for pediatric patients. Pediatric patients demonstrated significantly higher number of medication fills (9.11 fills) compared with adult patients (3.86 fills) ( P =0.007), which suggests interdisciplinary collaboration may facilitate sustainable management of a new therapy. The majority of pediatric (89%) and adult (90%) patients reported high satisfaction with Gln ("excellent") with minor or no side effects. Multidisciplinary health care provider collaborations and tracking medication adherence metrics can help address barriers to care for SCD patients.


Subject(s)
Anemia, Sickle Cell , Glutamine , Adult , Humans , Child , Glutamine/therapeutic use , Retrospective Studies , Medication Adherence , Anemia, Sickle Cell/drug therapy
9.
BMC Med Inform Decis Mak ; 22(1): 217, 2022 08 13.
Article in English | MEDLINE | ID: mdl-35964083

ABSTRACT

BACKGROUND: Primary care providers face challenges in recognizing and controlling hypertension in patients with chronic kidney disease (CKD). Clinical decision support (CDS) has the potential to aid clinicians in identifying patients who could benefit from medication changes. This study designed an alert to control hypertension in CKD patients using an iterative human-centered design process. METHODS: In this study, we present a human-centered design process employing multiple methods for gathering user requirements and feedback on design and usability. Initially, we conducted contextual inquiry sessions to gather user requirements for the CDS. This was followed by group design sessions and one-on-one formative think-aloud sessions to validate requirements, obtain feedback on the design and layout, uncover usability issues, and validate changes. RESULTS: This study included 20 participants. The contextual inquiry produced 10 user requirements which influenced the initial alert design. The group design sessions revealed issues related to several themes, including recommendations and clinical content that did not match providers' expectations and extraneous information on the alerts that did not provide value. Findings from the individual think-aloud sessions revealed that participants disagreed with some recommended clinical actions, requested additional information, and had concerns about the placement in their workflow. Following each step, iterative changes were made to the alert content and design. DISCUSSION: This study showed that participation from users throughout the design process can lead to a better understanding of user requirements and optimal design, even within the constraints of an EHR alerting system. While raising awareness of design needs, it also revealed concerns related to workflow, understandability, and relevance. CONCLUSION: The human-centered design framework using multiple methods for CDS development informed the creation of an alert to assist in the treatment and recognition of hypertension in patients with CKD.


Subject(s)
Decision Support Systems, Clinical , Hypertension , Renal Insufficiency, Chronic , Feedback , Humans , Hypertension/complications , Hypertension/therapy , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/therapy , Workflow
10.
Kidney Med ; 4(7): 100493, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35866010

ABSTRACT

Rationale & Objective: To design and implement clinical decision support incorporating a validated risk prediction estimate of kidney failure in primary care clinics and to evaluate the impact on stage-appropriate monitoring and referral. Study Design: Block-randomized, pragmatic clinical trial. Setting & Participants: Ten primary care clinics in the greater Boston area. Patients with stage 3-5 chronic kidney disease (CKD) were included. Patients were randomized within each primary care physician panel through a block randomization approach. The trial occurred between December 4, 2015, and December 3, 2016. Intervention: Point-of-care noninterruptive clinical decision support that delivered the 5-year kidney failure risk equation as well as recommendations for stage-appropriate monitoring and referral to nephrology. Outcomes: The primary outcome was as follows: Urine and serum laboratory monitoring test findings measured at one timepoint 6 months after the initial primary care visit and analyzed only in patients who had not undergone the recommended monitoring test in the preceding 12 months. The secondary outcome was nephrology referral in patients with a calculated kidney failure risk equation value of >10% measured at one timepoint 6 months after the initial primary care visit. Results: The clinical decision support application requested and processed 569,533 Continuity of Care Documents during the study period. Of these, 41,842 (7.3%) documents led to a diagnosis of stage 3, 4, or 5 CKD by the clinical decision support application. A total of 5,590 patients with stage 3, 4, or 5 CKD were randomized and included in the study. The link to the clinical decision support application was clicked 122 times by 57 primary care physicians. There was no association between the clinical decision support intervention and the primary outcome. There was a small but statistically significant difference in nephrology referral, with a higher rate of referral in the control arm. Limitations: Contamination within provider and clinic may have attenuated the impact of the intervention and may have biased the result toward null. Conclusions: The noninterruptive design of the clinical decision support was selected to prevent cognitive overload; however, the design led to a very low rate of use and ultimately did not improve stage-appropriate monitoring. Funding: Research reported in this publication was supported by the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health under award K23DK097187. Trial Registration: ClinicalTrials.gov Identifier: NCT02990897.

11.
BMJ Open ; 11(12): e054065, 2021 12 22.
Article in English | MEDLINE | ID: mdl-34937722

ABSTRACT

INTRODUCTION: The purpose of this study is to incorporate behavioural economic principles and user-centred design principles into a multicomponent intervention for the management of uncontrolled hypertension (HTN) in chronic kidney disease (CKD) in primary care. METHODS AND ANALYSIS: This is a multicentre, pragmatic, controlled trial cluster-randomised at the clinician level at The Brigham and Women's Practice -Based Research Network of 15 practices. Of 220 total clinicians, 184 were eligible to be enrolled, and the remainder were excluded (residents and clinicians who see urgent care or walk-in patients); no clinicians opted out. The intervention consists of a clinical decision support system based in behavioural economic and user-centred design principles that will: (1) synthesise existing laboratory tests, medication orders and vital sign data; (2) increase recognition of CKD, (3) increase recognition of uncontrolled HTN in CKD patients and (4) deliver evidence-based CKD and HTN management recommendations. The primary endpoint is the change in mean systolic blood pressure between baseline and 6 months compared across arms. We will use the Reach Effectiveness Adoption Implementation Maintenance framework. At the conclusion of this study, we will have: (1) validated an intervention that combines laboratory tests, medication records and clinical information collected by electronic health records to recognise uncontrolled HTN in CKD patients and recommend a course of care, (2) tested the effectiveness of said intervention and (3) collected information about the implementation of the intervention that will aid in dissemination of the intervention to other practice settings. ETHICS AND DISSEMINATION: The Human Subjects Institutional Review Board at Brigham and Women's Hospital provided an expedited review and approval for this study protocol, and a Data Safety Monitoring Board will ensure the ongoing safety of the trial. TRIAL REGISTRATION NUMBER: NCT03679247.


Subject(s)
Decision Support Systems, Clinical , Hypertension , Renal Insufficiency, Chronic , Blood Pressure , Electronic Health Records , Female , Humans , Hypertension/drug therapy , Multicenter Studies as Topic , Randomized Controlled Trials as Topic , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/diagnosis , Renal Insufficiency, Chronic/therapy
12.
JACC Case Rep ; 3(13): 1541-1544, 2021 Oct 06.
Article in English | MEDLINE | ID: mdl-34693356

ABSTRACT

A 48-year-old woman underwent preoperative cardiac testing prior to gastric bypass. She was incidentally found to have a right atrial mass on transthoracic echocardiography. Subsequent cardiac magnetic resonance confirmed this finding. She underwent excision of the mass. Tissue pathology revealed ectopic hepatic tissue. (Level of Difficulty: Advanced.).

13.
JACC Case Rep ; 3(8): 1086-1090, 2021 Jul 21.
Article in English | MEDLINE | ID: mdl-34317690

ABSTRACT

History and physical examination are the diagnostic cornerstones of transient loss of consciousness (TLOC). However, details can be scarce and examination unrevealing, thus making the diagnosis elusive. In a case of convulsive TLOC, the initial diagnosis was incorrect, but a fortuitously captured event on telemetry yielded the diagnosis: extrinsic idiopathic atrioventricular block. (Level of Difficulty: Beginner.).

14.
J Inorg Biochem ; 223: 111555, 2021 10.
Article in English | MEDLINE | ID: mdl-34315118

ABSTRACT

Trivalent chromium has been proposed to be transported in vivo from the bloodstream to the tissues via endocytosis by transferrin (Tf), the major iron transport protein in the blood. While Cr(III) loss from the Tf/Tf receptor complex after acidification to pH 5.5 has recently been shown to be sufficiently rapid to be physiologically relevant, the released Cr(III) still must exit the endosome during the time of the endocytosis cycle (circa 15 min). Cr(III) binds too slowly to small ligands such as citrate or ascorbate, or even EDTA, for such complexes to form and be transported from the endosome, while no trivalent ion transporters are known. However, the apo form of the peptide low-molecular-weight chromium-binding substance (LMWCr) can remove Cr(III) from Cr(III)2-Tf at neutral pH, albeit slowly, and LMWCr is known to be transported from cells after binding Cr(III), although the transporter is not known. LMWCr subsequently carries Cr(III) to the bloodstream ultimately for removal from the body in the urine. The rate of binding of Cr(III) to apoLMWCr was significantly enhanced in the presence of the Tf/Tf receptor complex. These results suggest that apoLMWCr may function to bind Cr(III) released in the endosomes for ultimate removal from the body as part of a Cr(III) detoxification process.


Subject(s)
Carrier Proteins/metabolism , Chromium/metabolism , Endosomes/metabolism , Transferrin/metabolism , Adenosine Triphosphate/metabolism , Animals , Cattle , Humans , Receptors, Transferrin/metabolism
16.
Trends Cardiovasc Med ; 31(1): 20-31, 2021 01.
Article in English | MEDLINE | ID: mdl-31862214

ABSTRACT

Hypertrophic cardiomyopathy (HCM) has a variable clinical presentation due to the diversity of causative genetic mutations. Animal models allow in vivo study of genotypic expression through non-invasive imaging, pathologic sampling, and force analysis. This review focuses on the spontaneous and induced mutations in various animal models affecting mainly sarcomere proteins. The sarcomere is comprised of thick (myosin) filaments and related proteins including myosin heavy chain and myosin binding protein-C; thin (actin) filament proteins and their associated regulators including tropomyosin, troponin I, troponin C, and troponin T. The regulatory milieu including transcription factors and cell signaling also play a significant role. Animal models provide a layered approach of understanding beginning with the causative mutation as a foundation. The functional consequences of protein energy utilization and calcium sensitivity in vivo and ex vivo can be studied. Beyond pathophysiologic disruption of sarcomere function, these models demonstrate the clinical sequalae of diastolic dysfunction, heart failure, and arrhythmogenic death. Through this cascade of understanding the mutation followed by their functional significance, targeted therapies have been developed and are briefly discussed.


Subject(s)
Cardiomyopathy, Hypertrophic/genetics , Mutation , Sarcomeres/genetics , Animals , Animals, Genetically Modified , Cardiomyopathy, Hypertrophic/metabolism , Cardiomyopathy, Hypertrophic/physiopathology , Cardiomyopathy, Hypertrophic/therapy , Disease Models, Animal , Gene Expression Regulation , Gene Targeting , Genetic Predisposition to Disease , Genetic Therapy , Humans , Molecular Targeted Therapy , Phenotype , Sarcomeres/metabolism , Signal Transduction , Species Specificity , Transcription Factors/genetics , Transcription Factors/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...