ABSTRACT
In cardiac myocytes, the type 2a sarco/endoplasmic reticulum Ca-ATPase (SERCA2a) plays a key role in intracellular Ca regulation. Due to its critical role in heart function, SERCA2a activity is tightly regulated by different mechanisms, including micropeptides. While phospholamban (PLB) is a well-known SERCA2a inhibitor, dwarf open reading frame (DWORF) is a recently identified SERCA2a activator. Since PLB phosphorylation is the most recognized mechanism of SERCA2a activation during adrenergic stress, we studied whether PLB phosphorylation also affects SERCA2a regulation by DWORF. By using confocal Ca imaging in a HEK293 expressing cell system, we analyzed the effect of the co-expression of PLB and DWORF using a bicistronic construct on SERCA2a-mediated Ca uptake. Under these conditions of matched expression of PLB and DWORF, we found that SERCA2a inhibition by non-phosphorylated PLB prevails over DWORF activating effect. However, when PLB is phosphorylated at PKA and CaMKII sites, not only PLB's inhibitory effect was relieved, but SERCA2a was effectively activated by DWORF. Förster resonance energy transfer (FRET) analysis between SERCA2a and DWORF showed that DWORF has a higher relative affinity for SERCA2a when PLB is phosphorylated. Thus, SERCA2a regulation by DWORF responds to the PLB phosphorylation status, suggesting that DWORF might contribute to SERCA2a activation during conditions of adrenergic stress.
Subject(s)
Calcium-Binding Proteins , Sarcoplasmic Reticulum Calcium-Transporting ATPases , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Calcium-Binding Proteins/metabolism , Humans , Phosphorylation , HEK293 Cells , Open Reading Frames/genetics , Calcium/metabolism , Enzyme Activation , Calcium-Calmodulin-Dependent Protein Kinase Type 2/metabolism , Cyclic AMP-Dependent Protein Kinases/metabolismABSTRACT
The most common cardiac pathologies, such as myocardial infarction and heart failure, are associated with oxidative stress. Oxidation of the cardiac ryanodine receptor (RyR2) Ca2+ channel causes spontaneous oscillations of intracellular Ca2+, resulting in contractile dysfunction and arrhythmias. RyR2 oxidation promotes the formation of disulfide bonds between two cysteines on neighboring RyR2 subunits, known as intersubunit cross-linking. However, the large number of cysteines in RyR2 has been a major hurdle in identifying the specific cysteines involved in this pathology-linked post-translational modification of the channel. Through mutagenesis of human RyR2 and in-cell Ca2+ imaging, we identify that only two cysteines (out of 89) in each RyR2 subunit are responsible for half of the channel's functional response to oxidative stress. Our results identify cysteines 1078 and 2991 as a redox-sensitive pair that forms an intersubunit disulfide bond between neighboring RyR2 subunits during oxidative stress, resulting in a pathological "leaky" RyR2 Ca2+ channel.
Subject(s)
Heart Failure , Ryanodine Receptor Calcium Release Channel , Humans , Arrhythmias, Cardiac/genetics , Arrhythmias, Cardiac/metabolism , Calcium/metabolism , Calcium Signaling , Disulfides/metabolism , Heart Failure/metabolism , Oxidation-Reduction , Ryanodine Receptor Calcium Release Channel/genetics , Ryanodine Receptor Calcium Release Channel/metabolism , Sarcoplasmic Reticulum/metabolismABSTRACT
Proficiency in clinical examination skills upon graduation from medical school is a core competency. Over the last few decades, the ability and confidence in this fundamental and crucial skill set has declined. The motivation and interest in meticulous physical examination by recently graduated residents has also eroded. In this case study, we describe a comprehensive, innovative, and immersive advanced clinical skills elective taken during the second half of the final year of medical school for students at the David Geffen School of Medicine. The course utilizes novel approaches to inspire, refresh and consolidate essential bedside observation skills and examination techniques. This approach gives senior students the confidence and fundamental understanding of how dedication to the patient exam can improve the doctor-patient relationship, core clinical reasoning and the practice of cost-effective and evidence-based care through their careers. We describe how the integration of fine art appreciation and introductory biding techniques are used to help students hone their visual diagnostic skills. We show how this is solidified through a longitudinal series of clinical image review sessions with diagnostic reasoning principles to formulate a clear differential. Point of care ultrasound, EKG analysis, advanced cardiac auscultation and diagnostic imaging skills are integrated in a comprehensive and memorable fashion. We present this case study to inspire clinical skills teachers everywhere to replicate our methods in resurrecting the importance of physical exams for their learners. Opening their trainees' eyes to new methods of honing their visual intelligence and developing healthy habits for stress and burnout reduction will aid the rest of their professional careers.
ABSTRACT
BACKGROUND: There are limited data on structural heart disease among people living with HIV in southern Africa, where the success of antiretroviral therapy (ART) has drastically improved life expectancy and where risk factors for cardiovascular disease are prevalent. METHODS: We performed a cross-sectional study of screening echocardiography among adults (≥18 years) with HIV in Malawi presenting for routine ART care. We used univariable and multivariable logistic regression to evaluate correlates of abnormal echocardiogram. RESULTS: A total of 202 individuals were enrolled with a median age of 45 years (IQR 39-52); 52% were female, and 27.7% were on antihypertensive medication. The most common clinically significant abnormality was left ventricular hypertrophy (LVH) (12.9%, n=26), and other serious structural heart lesions were rare (<2% with ejection fraction less than 40%, moderate-severe valve lesions or moderate-severe pericardial effusion). Characteristics associated with abnormal echocardiogram included older age (OR 1.04, 95% CI 1.01 to 1.08), higher body mass index (OR 1.09, 95% CI 1.02 to 1.17), higher mean systolic blood pressure (OR 1.03, 95% CI 1.02 to 1.05) and higher mean diastolic blood pressure (OR 1.03, 95% CI 1.01 to 1.05). In a multivariable model including age, duration on ART, body mass index, and systolic and diastolic blood pressure, only mean body mass index (adjusted OR 1.10, 95% CI 1.02 to 1.19), systolic blood pressure (aOR 1.05, 95% CI 1.03 to 1.08) and diastolic blood pressure (aOR 0.96, 95% CI 0.92 to 1.00) remained associated with abnormal echocardiogram. CONCLUSIONS: LVH was common in this population of adults on ART presenting for routine care and was associated with elevated blood pressure. Further research is needed to characterise the relationship between chronic hypertension, LVH and downstream consequences, such as diastolic dysfunction and heart failure in people living with HIV.
Subject(s)
HIV Infections , Hypertrophy, Left Ventricular , Adult , Cross-Sectional Studies , Echocardiography , Female , HIV Infections/complications , HIV Infections/diagnosis , HIV Infections/drug therapy , Humans , Hypertrophy, Left Ventricular/diagnostic imaging , Hypertrophy, Left Ventricular/epidemiology , Hypertrophy, Left Ventricular/etiology , Malawi/epidemiology , Male , Middle AgedABSTRACT
Background The Ovarian-Adnexal Reporting and Data System (O-RADS) US risk stratification and management system (O-RADS US) was designed to improve risk assessment and management of ovarian and adnexal lesions. Validation studies including both surgical and nonsurgical treatment as the reference standard remain lacking. Purpose To externally validate O-RADS US in women who underwent either surgical or nonsurgical treatment and to determine if incorporating acoustic shadowing as a benign finding improves diagnostic performance. Materials and Methods This retrospective study included consecutive women who underwent pelvic US between August 2015 and April 2017 at a tertiary referral oncology center. Two independent readers blinded to clinical and histologic outcome assigned an O-RADS risk category and an International Ovarian Tumor Analysis (IOTA) Assessment of Different NEoplasias in the adneXa (ADNEX) model risk of malignancy score to assessable lesions. Reference standards were surgical histopathology or 2-year imaging follow-up. Receiver operating characteristic (ROC) curve analysis was used to evaluate performance of the O-RADS US, ADNEX, and modified O-RADS models incorporating acoustic shadowing. Results In total, 227 women (mean age, 52 years ± 16 [SD]) with 262 ovarian or adnexal lesions were evaluated. Of these lesions, 187 (71%) were benign and 75 (29%) were malignant. The proportion of malignancy was 0% (0 of 100) for O-RADS 2, 3% (one of 32) for O-RADS 3, 35% (22 of 63) for O-RADS 4, and 78% (52 of 67) for O-RADS 5. The area under the ROC curve (AUC) for O-RADS and ADNEX was 0.91 (95% CI: 0.88, 0.94) and 0.95 (95% CI: 0.92, 0.97; P = .01), respectively. The addition of acoustic shadowing as a benign finding improved O-RADS AUC to 0.94 (95% CI: 0.91, 0.96; P = .01). Use of O-RADS 4 as a threshold yielded a sensitivity of 99% (74 of 75; 95% CI: 96, 100) and a specificity of 70% (131 of 187; 95% CI: 64, 77). Conclusion In a tertiary referral oncology center, the Ovarian-Adnexal Reporting and Data System US risk stratification and management system enabled accurate distinction of benign from malignant ovarian and adnexal lesions. Adding acoustic shadowing as a benign finding improved its diagnostic performance. © RSNA, 2022 See also the editorial by Levine in this issue.
Subject(s)
Adnexal Diseases , Ovarian Neoplasms , Adnexal Diseases/pathology , Data Systems , Female , Humans , Middle Aged , Ovarian Neoplasms/pathology , Retrospective Studies , Risk Assessment , Sensitivity and Specificity , Ultrasonography/methodsABSTRACT
The discontinuation of the United States Medical Licensing Examination Step 2 Clinical Skills Examination emphasizes the need for other reliable standardized assessments of medical student clinical skills. For 30 years, the California Consortium for the Assessment of Clinical Competence (CCACC) has collaborated in the development of clinical skills assessments and has become a valuable resource for clinicians, standardized patient educators, psychometricians, and medical educators. There are many merits to strong multi-institutional partnerships, including the integration of data across multiple schools to provide feedback to both students and curricula, pooled test performance statistics for analysis and quality assurance, shared best practices and resources, individual professional development, and opportunities for research and scholarship. The infrastructure of the CCACC allows member schools to adapt to a changing medical landscape, from emerging trends in clinical medicine to the limitations imposed by a global pandemic. In the absence of a national examination, there is now a greater need for all medical schools to develop a comprehensive, dynamic, and psychometrically sound assessment that accurately evaluates clinical skills. Medical schools working together in regional consortia have the opportunity to create and implement innovative and robust assessments that evaluate a wide range of clinical skills, ensure that medical students have met an expected level of clinical competency before graduation, and provide a framework that contributes to ongoing efforts for the development of new national clinical skills standards.
Subject(s)
Clinical Competence , Students, Medical , Curriculum , Feedback , Humans , Schools, Medical , United StatesABSTRACT
Background: Hypertension is among the most commonly diagnosed non-communicable diseases in Africa, and studies have demonstrated a high prevalence of hypertension among individuals with HIV. Despite high prevalence, there has been limited attention on the clinical outcomes of hypertension treatment in this population. Objective: We sought to characterize rates of and factors associated with blood pressure control over one year among individuals on antiretroviral therapy (ART) and antihypertensive medications. Methods: We performed a prospective observational cohort study at an HIV clinic in Malawi. We defined uncontrolled hypertension as a systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg at two or more follow-up visits during the year, while controlled hypertension was defined as <140 mm Hg systolic and <90 mm Hg diastolic at all visits, or at all but one visit. We calculated an antihypertensive non-adherence score based on self-report of missed doses at each visit (higher score = worse adherence) and used rank sum and chi-square tests to compare sociodemographic and clinical factors (including adherence) associated with blood pressure control over the year. Results: At study entry, 158 participants (23.5%) were on antihypertensive medication; participants had a median age of 51.0 years, were 66.5% female, and had a median of 6.9 years on ART. 19.0% (n = 30) achieved blood pressure control over the year of follow-up. Self-reported non-adherence to hypertension medications was the only factor significantly associated with uncontrolled blood pressure. The average non-adherence score for those with controlled blood pressure was 0.22, and for those with uncontrolled blood pressure was 0.61 (p = 0.009). Conclusions: Adults living with HIV and hypertension in our cohort had low rates of blood pressure control over one year associated with self-reported non-adherence to antihypertensive medications. Given the high prevalence and incidence of hypertension, interventions to improve blood pressure control are needed to prevent associated long-term cardio- and cerebrovascular morbidity and mortality.
Subject(s)
HIV Infections , Hypertension , Adult , Antihypertensive Agents , Blood Pressure , Female , HIV Infections/complications , HIV Infections/drug therapy , HIV Infections/epidemiology , Humans , Hypertension/diagnosis , Hypertension/drug therapy , Hypertension/epidemiology , Malawi/epidemiology , Male , Medication Adherence , Middle Aged , Prospective StudiesABSTRACT
The gamma secretase catalytic subunit presenilin 1 (PS1) is expressed in the endoplasmic reticulum (ER) of neurons, where it regulates Ca2+ signaling. PS1 is also expressed in heart, but its role in regulation of cardiac Ca2+ transport remains unknown. Since the type 2 sarco/endoplasmic reticulum Ca2+ ATPase (SERCA2a) plays a central role in cardiac Ca2+ homeostasis, we studied whether PS1 regulates the cardiac SERCA2a function. The experiments were conducted in an inducible human SERCA2a stable T-Rex-293 cell line transfected with fluorescently labeled PS1 and the ER Ca2+ sensor R-CEPIA1er. Confocal imaging showed that that PS1 is localized predominantly in the ER membrane. Fluorescent resonance energy transfer (FRET) experiments in HEK293 cells transfected with fluorescently labeled SERCA2a and PS1 revealed that the two proteins directly interact with a 1:1 stoichiometry. The functional significance of this interaction was investigated in a heterologous cellular environment using a novel approach to directly measure ER Ca2+ dynamics. Measurements of SERCA2a-mediated Ca2+ transport showed that PS1 enhanced Ca2+ uptake at low ER Ca2+ loads (<0.15 mM) and reduced uptake at high loads (>0.35 mM). The results of this study revealed that PS1 could act as an important regulator of the cardiac Ca2+ pump function with a complex stimulatory/inhibitory profile.
Subject(s)
Calcium , Endoplasmic Reticulum , Calcium/metabolism , Endoplasmic Reticulum/metabolism , HEK293 Cells , Humans , Presenilin-1/genetics , Presenilin-1/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolismABSTRACT
Malawi has the highest incidence of and mortality rate due to cervical cancer in the world. This is largely because of inadequate screening and high rates of human immunodeficiency virus (HIV) infection, which greatly increases cervical cancer risk. We describe the implementation of a quality improvement program to increase use of cervical cancer screening at a non-government medical center in Lilongwe, Malawi. The intervention, developed and launched from March to August 2017, aimed to promote education among patients and clinicians about the importance of cervical cancer screening and improve accessibility of screening information within medical records. Visual inspection with acetic acid (VIA) was used to screen for cervical cancer. Women with a positive VIA were offered treatment using thermocoagulation. The number of VIA screenings conducted in 2016 (pre-intervention), 2017 (intervention), and 2018 (post-intervention) was 125, 234 and 456, respectively. Of the 815 women screened during this period, 36 (4.4%) had a VIA-positive result and 12 (1.5%) had suspect cancer. Of the VIA-positive women, 13 (36.1%) received same-day treatment with thermocoagulation. An interrupted time series regression revealed that there was a sustained increase in monthly screenings between the pre- and post-intervention period (ß = 30.84; p = 0.006; 95% CI 9.72-51.97), suggesting that the intervention likely was effective in increasing cervical cancer screening. Our results demonstrate that focusing on developing sustainable solutions and improving system processes, without additional equipment or funding, significantly increased the number of women screened and should be considered in other settings to enhance cervical cancer prevention services.
Subject(s)
Uterine Cervical Neoplasms , Early Detection of Cancer , Female , Humans , Malawi/epidemiology , Mass Screening , Uterine Cervical Neoplasms/diagnosisABSTRACT
ABSTRACT: A 63-year-old man with recent diagnosis of high-risk prostate adenocarcinoma was referred to our Nuclear Medicine Department for 18F-fluciclovine PET/CT to rule out metastasis in the setting of elevated serum prostate-specific antigen levels. The patient had previous history of nodular melanoma of the right cheek treated 6 years back with surgery and adjuvant radiation. Surveillance 18F-FDG PET/CT for melanoma 1 month back had revealed enlarged FDG-avid mediastinal para-aortic lymph nodes, which on endoscopic biopsy had revealed melanoma metastasis. On current fluciclovine PET/CT, the same enlarged para-aortic lymph nodes showed fluciclovine uptake, suggesting false-positive uptake.
Subject(s)
Carboxylic Acids , Cyclobutanes , Melanoma/pathology , Positron Emission Tomography Computed Tomography , Skin Neoplasms/pathology , Humans , Lymphatic Metastasis , Male , Middle Aged , Melanoma, Cutaneous MalignantABSTRACT
The type 2a sarco/endoplasmic reticulum (ER) Ca2+-ATPase (SERCA2a) plays a key role in intracellular Ca2+ regulation in the heart. We have previously shown evidence of stable homodimers of SERCA2a in heterologous cells and cardiomyocytes. However, the functional significance of the pump dimerization remains unclear. Here, we analyzed how SERCA2a dimerization affects ER Ca2+ transport. Fluorescence resonance energy transfer experiments in HEK293 cells transfected with fluorescently labeled SERCA2a revealed increasing dimerization of Ca2+ pumps with increasing expression level. This concentration-dependent dimerization provided means of comparison of the functional characteristics of monomeric and dimeric pumps. SERCA-mediated Ca2+ uptake was measured with the ER-targeted Ca2+ sensor R-CEPIA1er in cells cotransfected with SERCA2a and ryanodine receptor. For each individual cell, the maximal ER Ca2+ uptake rate and the maximal Ca2+ load, together with the pump expression level, were analyzed. This analysis revealed that the ER Ca2+ uptake rate increased as a function of SERCA2a expression, with a particularly steep, nonlinear increase at high expression levels. Interestingly, the maximal ER Ca2+ load also increased with an increase in the pump expression level, suggesting improved catalytic efficiency of the dimeric species. Reciprocally, thapsigargin inhibition of a fraction of the population of SERCA2a reduced not only the maximal ER Ca2+ uptake rate but also the maximal Ca2+ load. These data suggest that SERCA2a dimerization regulates Ca2+ transport by improving both the SERCA2a turnover rate and catalytic efficacy. Analysis of ER Ca2+ uptake in cells cotransfected with human wild-type SERCA2a (SERCA2aWT) and SERCA2a mutants with different catalytic activity revealed that an intact catalytic cycle in both protomers is required for enhancing the efficacy of Ca2+ transport by a dimer. The data are consistent with the hypothesis of functional coupling of two SERCA2a protomers in a dimer that reduces the energy barrier of rate-limiting steps of the catalytic cycle of Ca2+ transport.
Subject(s)
Calcium , Sarcoplasmic Reticulum Calcium-Transporting ATPases , Calcium/metabolism , Dimerization , HEK293 Cells , Humans , Ryanodine Receptor Calcium Release Channel/metabolism , Sarcoplasmic Reticulum/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolismABSTRACT
The type 2 ryanodine receptor (RyR2) plays a key role in the cardiac intracellular calcium (Ca2+) regulation. We have previously shown that oxidative stress activates RyR2 in rabbit cardiomyocytes by promoting the formation of disulfide bonds between neighboring RyR2 subunits. However, the functional significance of this redox modification for human RyR2 (hRyR2) remains largely unknown. Here, we studied the redox regulation of hRyR2 in HEK293 cells transiently expressing the ryr2 gene. Analysis of hRyR2 cross-linking and of the redox-GFP readout response to diamide oxidation revealed that hRyR2 cysteines involved in the intersubunit cross-linking are highly sensitive to oxidative stress. In parallel experiments, the effect of diamide on endoplasmic reticulum (ER) Ca2+ release was studied in cells co-transfected with hRyR2, ER Ca2+ pump (SERCA2a) and the ER-targeted Ca2+ sensor R-CEPIA1er. Expression of hRyR2 and SERCA2a produced "cardiac-like" Ca2+ waves due to spontaneous hRyR2 activation. Incubation with diamide caused a fast decline of the luminal ER Ca2+ (or ER Ca2+ load) followed by the cessation of Ca2+ waves. The maximal effect of diamide on ER Ca2+ load and Ca2+ waves positively correlates with the maximum level of hRyR2 cross-linking, indicating a functional significance of this redox modification. Furthermore, the level of hRyR2 cross-linking positively correlates with the degree of calmodulin (CaM) dissociation from the hRyR2 complex. In skeletal muscle RyR (RyR1), cysteine 3635 (C3635) is viewed as dominantly responsible for the redox regulation of the channel. Here, we showed that the corresponding cysteine 3602 (C3602) in hRyR2 does not participate in intersubunit cross-linking and plays a limited role in the hRyR2 regulation by CaM during oxidative stress. Collectively, these results suggest that redox-mediated intersubunit cross-linking is an important regulator of hRyR2 function under pathological conditions associated with oxidative stress.
Subject(s)
Calcium Signaling , Ryanodine Receptor Calcium Release Channel , Animals , Calcium/metabolism , HEK293 Cells , Humans , Oxidation-Reduction , Rabbits , Ryanodine Receptor Calcium Release Channel/genetics , Ryanodine Receptor Calcium Release Channel/metabolismABSTRACT
OBJECTIVES: As HIV-positive individuals' life expectancy extends, there is an urgent need to manage other chronic conditions during HIV care. We assessed the care-seeking experiences and costs of adults receiving treatment for both HIV and hypertension in Malawi. DESIGN, SETTING AND PARTICIPANTS: A cross-sectional survey was conducted with HIV-positive adults with hypertension at a health facility in Lilongwe that offers free HIV care and free hypertension screening, with antihypertensives available for purchase (n=199). Questions included locations and costs of all medication refills and preferences for these refill locations. Respondents were classified as using 'integrated care' if they refilled HIV and antihypertensive medications simultaneously. Data were collected between June and December 2017. RESULTS: Only half of respondents reported using the integrated care offered at the study site. Among individuals using different locations for antihypertensive medication refills, the most frequent locations were drug stores and public sector health facilities which were commonly selected due to greater convenience and lower medication costs. Although the number of antihypertensive medications was equivalent between the integrated and non-integrated care groups, the annual total cost of care differed substantially (approximately US$21 in integrated care vs US$90 for non-integrated care)-mainly attributable to differences in other visit costs for non-integrated care (transportation, lost wages, childcare). One-third of those in the non-integrated care group reported no expenditure for antihypertensive medication, and six people in each group reported no annual hypertension care-seeking costs at all. CONCLUSIONS: Individuals using integrated care saw efficiencies because, although they were more likely to pay for antihypertensive medications, they did not incur additional costs. These results suggest that preferences and experiences must be better understood to design effective policies and programmes for integrated care among adults on antiretroviral therapy.
Subject(s)
Antihypertensive Agents/economics , Antiretroviral Therapy, Highly Active/economics , Delivery of Health Care, Integrated/methods , HIV Infections/drug therapy , Health Expenditures/statistics & numerical data , Hypertension/drug therapy , Antihypertensive Agents/therapeutic use , Antiretroviral Therapy, Highly Active/methods , Cross-Sectional Studies , Delivery of Health Care, Integrated/economics , Female , HIV Infections/complications , HIV Infections/economics , Humans , Hypertension/complications , Hypertension/economics , Malawi , Male , Medication Adherence/statistics & numerical data , Middle AgedABSTRACT
BACKGROUND: The focused assessment with sonography for HIV-associated tuberculosis (TB) (FASH) ultrasound protocol has been increasingly used to help clinicians diagnose TB. We sought to quantify the diagnostic utility of FASH for TB among individuals with HIV in Malawi. METHODS: Between March 2016 and August 2017, 210 adults with HIV who had 2 or more signs and symptoms that were concerning for TB (fever, cough, night sweats, weight loss) were enrolled from a public HIV clinic in Lilongwe, Malawi. The treating clinicians conducted a history, physical exam, FASH protocol, and additional TB evaluation (laboratory diagnostics and chest radiography) on all participants. The clinician made a final treatment decision based on all available information. At the 6-month follow-up visit, we categorized participants based on clinical outcomes and diagnostic tests as having probable/confirmed TB or unlikely TB; association of FASH with probable/confirmed TB was calculated using Fisher's exact tests. The impact of FASH on empiric TB treatment was determined by asking the clinicians prospectively about whether they would start treatment at 2 time points in the baseline visit: (1) after the initial history and physical exam; and (2) after history, physical exam, and FASH protocol. RESULTS: A total of 181 participants underwent final analysis, of whom 56 were categorized as probable/confirmed TB and 125 were categorized as unlikely TB. The FASH protocol was positive in 71% (40/56) of participants with probable/confirmed TB compared to 24% (30/125) of participants with unlikely TB (odds ratio=7.9, 95% confidence interval=3.9,16.1; P<.001). Among those classified as confirmed/probable TB, FASH increased the likelihood of empiric TB treatment before obtaining any other diagnostic studies from 9% (5/56) to 46% (26/56) at the point-of-care. For those classified as unlikely TB, FASH increased the likelihood of empiric treatment from 2% to 4%. CONCLUSION: In the setting of HIV coinfection in Malawi, FASH can be a helpful tool that augments the clinician's ability to make a timely diagnosis of TB.
Subject(s)
HIV Infections/complications , Point-of-Care Testing , Tuberculosis/diagnostic imaging , Adult , Antitubercular Agents , Ascites/diagnostic imaging , Ascites/etiology , Cohort Studies , Coinfection , Female , Humans , Lipopolysaccharides/urine , Liver/diagnostic imaging , Lymphadenopathy/diagnostic imaging , Lymphadenopathy/etiology , Malawi , Male , Middle Aged , Nucleic Acid Amplification Techniques , Pericardial Effusion/diagnostic imaging , Pericardial Effusion/etiology , Pleural Effusion/diagnostic imaging , Pleural Effusion/etiology , Prospective Studies , Radiography, Thoracic , Spleen/diagnostic imaging , Tuberculosis/complications , Tuberculosis/diagnosis , Tuberculosis/drug therapy , Tuberculosis, Hepatic/complications , Tuberculosis, Hepatic/diagnostic imaging , Tuberculosis, Lymph Node/complications , Tuberculosis, Lymph Node/diagnostic imaging , Tuberculosis, Splenic/complications , Tuberculosis, Splenic/diagnostic imaging , Ultrasonography/methodsABSTRACT
BACKGROUND: Point-of-care ultrasound is increasingly being used as a diagnostic tool in resource-limited settings. The majority of existing ultrasound protocols have been developed and implemented in high-resource settings. In sub-Saharan Africa (SSA), patients with heart failure of various etiologies commonly present late in the disease process, with a similar syndrome of dyspnea, edema and cardiomegaly on chest X-ray. The causes of heart failure in SSA differ from those in high-resource settings. Point-of-care ultrasound has the potential to identify the underlying etiology of heart failure, and lead to targeted therapy. Based on a literature review and weighted score of disease prevalence, diagnostic impact and difficulty in performing the ultrasound, we propose a context-specific cardiac ultrasound protocol to help differentiate patients presenting with heart failure in SSA. RESULTS: Pericardial effusion, dilated cardiomyopathy, cor pulmonale, mitral valve disease, and left ventricular hypertrophy were identified as target conditions for a focused ultrasound protocol in patients with cardiac failure and cardiomegaly in SSA. By utilizing a simplified 5-question approach with all images obtained from the subxiphoid view, the protocol is suitable for use by health care professionals with limited ultrasound experience. CONCLUSIONS: The "Cardiac ultrasound for resource-limited settings (CURLS)" protocol is a context-specific algorithm designed to aid the clinician in diagnosing the five most clinically relevant etiologies of heart failure and cardiomegaly in SSA. The protocol has the potential to influence treatment decisions in patients who present with clinical signs of heart failure in resource-limited settings outside of the traditional referral institutions.
ABSTRACT
Non-communicable diseases like hypertension are increasingly common among individuals living with HIV in low-resource settings. The prevalence of hypertension among people with HIV in Malawi, e.g. has been estimated to be as high as 46%. However, few qualitative studies have explored the patient experience with comorbid chronic disease. Our study aimed to address this gap by using the health belief model (HBM) to examine how comparative perceptions of illness and treatment among participants with both HIV and hypertension may affect medication adherence behaviours. We conducted semi-structured interviews with 75 adults with HIV and hypertension at an urban clinic in Lilongwe, Malawi. Questions addressed participants' experiences with antiretroviral and antihypertensive medications, as well as their perspectives on HIV and hypertension as illnesses. Interviews were performed in Chichewa, transcribed, translated into English and analysed using ATLAS.ti. Deductive codes were drawn from the HBM and interview guide, with inductive codes added as they emerged from the data. Self-reported medication adherence was much poorer for hypertension than HIV, but participants saw hypertension as a disease at least as concerning as HIV-primarily due to the perceived severity of hypertension's consequences and participants' limited ability to anticipate them compared with HIV. Differences in medication adherence were attributed to the high costs of antihypertensive medications relative to the free availability of antiretroviral therapy, with other factors like lifestyle changes and self-efficacy also influencing adherence practices. These findings demonstrate how participants draw on past experiences with HIV to make sense of hypertension in the present, and suggest that although patients are motivated to control their hypertension, they face individual- and system-level obstacles in adhering to treatment. Thus, health policies and systems seeking to provide integrated care for HIV and hypertension should be attentive to the complex illness experiences of individuals living with these diseases.
Subject(s)
Anti-Retroviral Agents/therapeutic use , Antihypertensive Agents , HIV Infections/drug therapy , Hypertension/drug therapy , Medication Adherence/statistics & numerical data , Anti-Retroviral Agents/economics , Antihypertensive Agents/administration & dosage , Antihypertensive Agents/economics , Female , HIV Infections/psychology , Health Behavior , Humans , Hypertension/epidemiology , Hypertension/psychology , Interviews as Topic , Malawi/epidemiology , Male , Medication Adherence/psychology , Middle Aged , Qualitative ResearchABSTRACT
The type 2a sarco-/endoplasmic reticulum Ca2+-ATPase (SERCA2a) plays a key role in Ca2+ regulation in the heart. However, available techniques to study SERCA function are either cell destructive or lack sensitivity. The goal of this study was to develop an approach to selectively measure SERCA2a function in the cellular environment. The genetically encoded Ca2+ sensor R-CEPIA1er was used to measure the concentration of Ca2+ in the lumen of the endoplasmic reticulum (ER) ([Ca2+]ER) in HEK293 cells expressing human SERCA2a. Coexpression of the ER Ca2+ release channel ryanodine receptor (RyR2) created a Ca2+ release/reuptake system that mimicked aspects of cardiac myocyte Ca2+ handling. SERCA2a function was quantified from the rate of [Ca2+]ER refilling after ER Ca2+ depletion; then, ER Ca2+ leak was measured after SERCA inhibition. ER Ca2+ uptake and leak were analyzed as a function of [Ca2+]ER to determine maximum ER Ca2+ uptake rate and maximum ER Ca2+ load. The sensitivity of this assay was validated by analyzing effects of SERCA inhibitors, [ATP]/[ADP], oxidative stress, phospholamban, and a loss-of-function SERCA2a mutation. In addition, the feasibility of using R-CEPIA1er to study SERCA2a in a native system was evaluated by using in vivo gene delivery to express R-CEPIA1er in mouse hearts. After ventricular myocyte isolation, the same methodology used in HEK293 cells was applied to study endogenous SERCA2a. In conclusion, this new approach can be used as a sensitive screening tool to study the effect of different drugs, posttranslational modifications, and mutations on SERCA function. NEW & NOTEWORTHY The aim of this study was to develop a sensitive approach to selectively measure sarco-/endoplasmic reticulum Ca2+-ATPase (SERCA) function in the cellular environment. The newly developed Ca2+ sensor R-CEPIA1er was used to successfully analyze Ca2+ uptake mediated by recombinant and native cardiac SERCA. These results demonstrate that this new approach can be used as a powerful tool to study new mechanisms of Ca2+ pump regulation.
Subject(s)
Calcium/metabolism , Endoplasmic Reticulum/enzymology , Myocytes, Cardiac/enzymology , Ryanodine Receptor Calcium Release Channel/metabolism , Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism , Sarcoplasmic Reticulum/enzymology , Adenosine Diphosphate/metabolism , Adenosine Triphosphate/metabolism , Animals , Biological Transport , Biosensing Techniques , Calcium-Binding Proteins/metabolism , Endoplasmic Reticulum/drug effects , Enzyme Inhibitors/pharmacology , HEK293 Cells , Humans , Mice, Inbred C57BL , Mutation , Myocytes, Cardiac/drug effects , Oxidative Stress , Ryanodine Receptor Calcium Release Channel/genetics , Sarcoplasmic Reticulum/drug effects , Sarcoplasmic Reticulum Calcium-Transporting ATPases/antagonists & inhibitors , Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics , Time FactorsSubject(s)
AIDS-Related Opportunistic Infections/diagnostic imaging , Education, Distance/organization & administration , Radiology/education , Teleradiology , Tuberculosis/diagnostic imaging , Ultrasonography/standards , Clinical Competence , Female , Humans , Los Angeles , Malawi , Male , Prospective StudiesABSTRACT
The purpose of our student-led project was to fulfill junior medical students' demand for instructive, curriculum-specific practice questions while providing a learning experience and teaching opportunity for participating senior students. Eleven second-year students were taught how to write high-quality multiple-choice questions through an interactive workshop. Subsequently, they were instructed to write questions with detailed explanations for their assigned lecture topics. Thirty-four student-written and faculty-reviewed questions were combined with 16 purely faculty-written questions to create a 50-question exam. No significant difference was found in question difficulty between the student-written (79.5%) and faculty-written (84.0%) questions (p = 0.37). The discrimination index and point biserial correlation were higher for student-written (0.29, 0.32) vs. faculty-written (0.17, 0.25) questions (p < .01, < .05). The test-takers learned key course topics, while the test-writers reviewed key first-year objectives and refined their test-taking strategies. The project provided a model for feasibly developing comprehensive, high-quality, and curriculum-specific questions.
ABSTRACT
Liver abscess is a rare but serious complication of Crohn's disease. Patients with Crohn's disease are at risk for pyogenic liver abscesses due to immunosuppressive therapy, fistulous disease, and intraabdominal abscesses. Inflammatory bowel disease patients are also known to have a greater prevalence of amebiasis compared to the rest of the population; however, a higher incidence of amebic liver abscess has not been reported. We describe a case of a liver abscess in a patient with Crohn's disease that was initially presumed pyogenic but later determined to be amebic in origin. Epidemiology, clinical presentation, diagnosis, and treatment of amebic and pyogenic liver abscesses are discussed.