Feasibility and Methodology of a Pilot Free Blood Pressure Monitoring and Follow-Up Program at Two Free Clinics.

BACKGROUND: Hypertension affects approximately 1 in 2 adults in the US. Home blood pressure (BP) monitoring programs are effective in the diagnosis and management of hypertension. Free clinics serve as an integral safety net for millions of uninsured and economically disadvantaged patients in the US. The feasibility and effects of a free home BP monitoring and follow-up program in a free clinic setting is not well characterized. METHODS: This was a prospective study of the implementation of a pilot BP monitoring and follow-up program between March 2021 and August 2023 at 2 free clinics in the San Francisco Bay Area. A total of 78 hypertensive patients were enrolled in the program and given a free BP monitor. We surveyed via telephone the change in systolic and diastolic BPs and BP monitor use and comfort at 3 weeks. Volunteers in clinic roles involved in the BP monitoring program were surveyed to assess their time spent and perceptions of the program. RESULTS: Of the 78 patients, 37 provided responses to the 3-week survey. A total of 36 of 37 (97%) patients reported using their BP monitor. A total of 35 patients reported using it at least once a week (95%), with the majority reporting at least four uses a week (68%). A total of 36 patients (97%) planned on continuing to use their BP monitor. At 3 weeks, the mean systolic and diastolic BP changed by -6.40 mmHg (95% CI, -10.8 to -2.01 mmHg; P = .00577) and -2.72 mmHg (95% CI, -5.62 to 0.188 mmHg; P = .0657), respectively. The time commitment for this program ranged from 130 ± 51 min for program leaders to 16 ± 14 min per week for patient-facing roles. All volunteer roles (patient-facing, phone follow-up, program leaders) expressed that they had a clear understanding of their responsibilities in the program (median 4 on Likert scale, IQR 3-5). CONCLUSION: Home BP monitoring and follow-up is feasible to implement in free clinics, resulting in high rates of patient engagement among respondents. Our findings suggest that home BP monitoring and follow-up programs may be beneficial in vulnerable patient populations.

Evaluation of ChatGPT as a diagnostic tool for medical learners and clinicians.

BACKGROUND: ChatGPT is a large language model (LLM) trained on over 400 billion words from books, articles, and websites. Its extensive training draws from a large database of information, making it valuable as a diagnostic aid. Moreover, its capacity to comprehend and generate human language allows medical trainees to interact with it, enhancing its appeal as an educational resource. This study aims to investigate ChatGPT's diagnostic accuracy and utility in medical education. METHODS: 150 Medscape case challenges (September 2021 to January 2023) were inputted into ChatGPT. The primary outcome was the number (%) of cases for which the answer given was correct. Secondary outcomes included diagnostic accuracy, cognitive load, and quality of medical information. A qualitative content analysis was also conducted to assess its responses. RESULTS: ChatGPT answered 49% (74/150) cases correctly. It had an overall accuracy of 74%, a precision of 48.67%, sensitivity of 48.67%, specificity of 82.89%, and an AUC of 0.66. Most answers were considered low cognitive load 51% (77/150) and most answers were complete and relevant 52% (78/150). DISCUSSION: ChatGPT in its current form is not accurate as a diagnostic tool. ChatGPT does not necessarily give factual correctness, despite the vast amount of information it was trained on. Based on our qualitative analysis, ChatGPT struggles with the interpretation of laboratory values, imaging results, and may overlook key information relevant to the diagnosis. However, it still offers utility as an educational tool. ChatGPT was generally correct in ruling out a specific differential diagnosis and providing reasonable next diagnostic steps. Additionally, answers were easy to understand, showcasing a potential benefit in simplifying complex concepts for medical learners. Our results should guide future research into harnessing ChatGPT's potential educational benefits, such as simplifying medical concepts and offering guidance on differential diagnoses and next steps.

Extraction of Unstructured Electronic Health Records to Evaluate Glioblastoma Treatment Patterns.

PURPOSE: Data on lines of therapy (LOTs) for cancer treatment are important for clinical oncology research, but LOTs are not explicitly recorded in electronic health records (EHRs). We present an efficient approach for clinical data abstraction and a flexible algorithm to derive LOTs from EHR-based medication data on patients with glioblastoma multiforme (GBM). METHODS: Nonclinicians were trained to abstract the diagnosis of GBM from EHRs, and their accuracy was compared with abstraction performed by clinicians. The resulting data were used to build a cohort of patients with confirmed GBM diagnosis. An algorithm was developed to derive LOTs using structured medication data, accounting for the addition and discontinuation of therapies and drug class. Descriptive statistics were calculated and time-to-next-treatment (TTNT) analysis was performed using the Kaplan-Meier method. RESULTS: Treating clinicians as the gold standard, nonclinicians abstracted GBM diagnosis with a sensitivity of 0.98, specificity 1.00, positive predictive value 1.00, and negative predictive value 0.90, suggesting that nonclinician abstraction of GBM diagnosis was comparable with clinician abstraction. Of 693 patients with a confirmed diagnosis of GBM, 246 patients contained structured information about the types of medications received. Of them, 165 (67.1%) received a first-line therapy (1L) of temozolomide, and the median TTNT from the start of 1L was 179 days. CONCLUSION: We described a workflow for extracting diagnosis of GBM and LOT from EHR data that combines nonclinician abstraction with algorithmic processing, demonstrating comparable accuracy with clinician abstraction and highlighting the potential for scalable and efficient EHR-based oncology research.

Selective prediction for extracting unstructured clinical data.

OBJECTIVE: While there are currently approaches to handle unstructured clinical data, such as manual abstraction and structured proxy variables, these methods may be time-consuming, not scalable, and imprecise. This article aims to determine whether selective prediction, which gives a model the option to abstain from generating a prediction, can improve the accuracy and efficiency of unstructured clinical data abstraction. MATERIALS AND METHODS: We trained selective classifiers (logistic regression, random forest, support vector machine) to extract 5 variables from clinical notes: depression (n = 1563), glioblastoma (GBM, n = 659), rectal adenocarcinoma (DRA, n = 601), and abdominoperineal resection (APR, n = 601) and low anterior resection (LAR, n = 601) of adenocarcinoma. We varied the cost of false positives (FP), false negatives (FN), and abstained notes and measured total misclassification cost. RESULTS: The depression selective classifiers abstained on anywhere from 0% to 97% of notes, and the change in total misclassification cost ranged from -58% to 9%. Selective classifiers abstained on 5%-43% of notes across the GBM and colorectal cancer models. The GBM selective classifier abstained on 43% of notes, which led to improvements in sensitivity (0.94 to 0.96), specificity (0.79 to 0.96), PPV (0.89 to 0.98), and NPV (0.88 to 0.91) when compared to a non-selective classifier and when compared to structured proxy variables. DISCUSSION: We showed that selective classifiers outperformed both non-selective classifiers and structured proxy variables for extracting data from unstructured clinical notes. CONCLUSION: Selective prediction should be considered when abstaining is preferable to making an incorrect prediction.

Ocular manifestations of COVID-19: systematic review and meta-analysis.

OBJECTIVE: Our study aims to build on our understanding of COVID-19 by detailing a comprehensive look at the prevalence of different ocular manifestations related to COVID-19 infection. DESIGN: Systematic review and meta-analysis. METHODS: Eligible studies published between June 20, 2021, and May 11, 2023, were retrieved from the MEDLINE, EMBASE, and CINAHL databases as well as grey literature. Covidence was used to conduct the systematic review. Duplicate records were removed, and 2 independent reviewers screened records for relevance. After screening, a risk-of-bias assessment was carried out. Data were extracted, and a meta-analysis was performed using STATA 14.0. Fixed-effects and random-effects models were computed based on heterogeneity. RESULTS: Our meta-analysis included 43 articles with a total of 10,572 subjects. The results showed that COVID-19 patients had a significantly higher prevalence of conjunctivitis (effect size [ES] = 0.11; 95% CI, 0.07-0.15), ptosis (ES = 0.22; 95% CI, 0.15-0.30), and ophthalmoplegia (ES = 0.40; 95% CI, 0.06-0.74). Our results also indicate that COVID-19 patients have higher prevalence of cotton wool spots (ES = 0.06; 95% CI, 0.03-0.09), retinal hemorrhages (ES = 0.12; 95% CI, 0.06-0.18), and retinal vein tortuosity (ES = 0.19; 95% CI, 0.09-0.35). CONCLUSION: COVID-19 can exhibit extrapulmonary manifestations, affecting both the anterior and posterior segments of the eye. Common anterior-segment findings include conjunctivitis, whereas posterior-segment findings may include cotton wool spots, retinal hemorrhages, and retinal vein tortuosity. Improving our understanding of the ocular manifestations of COVID-19 has the potential to facilitate quicker diagnosis and subsequent treatment.

The effects of age-related macular degeneration on work productivity: A meta-analysis.

Age-related macular degeneration (AMD) is one of the leading causes of vision loss and blindness in older adults. Given the aging population in developed countries and the increased participation of older adults in the labour market, this paper aims to understand the impact of AMD on workplace productivity. Economic studies, comparative studies, observational studies, cohort studies, case series, randomized control trials, clinical trials, multicenter studies from MEDLINE, EMBASE, and CINHAL, as well as grey literature, were systematically searched to obtain all relevant literature. Duplicate records were removed, and two independent reviewers screened records for relevance. After screening, a risk of bias assessment was carried out. Data were extracted and a meta-analysis was performed using STATA 15.0. Fixed-effect and random-effect models were computed based on heterogeneity. Seven studies consisting of 3,060,864 subjects from 5 different countries were included in this systematic review. Mean wages lost due to impaired work productivity ranged from $1,395 to $55,180. The mean unemployment rate attributed to AMD ranged from 5.50% to 77.00%. Meta-analysis results indicated a significant unemployment rate (SMD = 0.44, CI: [0.27, 0.62]). Patients with AMD experience impaired work productivity as demonstrated by the wages lost and significantly higher rates of unemployment.

Affordable IgY-based antiviral prophylaxis for resource-limited settings to address epidemic and pandemic risks.

Background: The COVID-19 pandemic caused by SARS-CoV-2 exposed a global problem, as highly effective vaccines are challenging to produce and distribute, particularly in regions with limited resources and funding. As an alternative, immunoglobulins produced in eggs of immunized hens (IgY) can be a simple and inexpensive source for a topical and temporary prophylaxis. Here, we developed a method to extract and purify IgY antibodies from egg yolks of hens immunized against viral pathogen-derived proteins using low-cost, readily available materials, for use in resource-limited settings. Methods: Existing protocols for IgY purification and equipment were modified, including extraction from yolks and separation of water-soluble IgY using common household reagents and tools. A replacement for a commercial centrifuge was developed, using a home food processor equipped with a 3D printed adapter to enable IgY precipitation. IgY purification was verified using standard gel electrophoresis and Western blot analyses. Results: We developed a step-by-step protocol for IgY purification for two settings in low- and middle-income countries (LMIC): a local laboratory, where commercial centrifuges are available, or a more rural setting, where an alternative for expensive centrifuges can be used. Gel electrophoresis and Western blot analyses confirmed that the method produced highly enriched IgY preparation; each commercial egg produced ~ 90 mg of IgY. We also designed a kit for IgY production in these two settings and provided a cost estimate of the kit. Conclusion: IgY purified from eggs of immunized local hens can offer a fast and affordable prophylaxis, provided that purification can be performed in a resource-limited setting. Here, we created a low-cost method that can be used anywhere where electricity is available using inexpensive, readily available materials in place of costly, specialized laboratory equipment and chemicals. This procedure can readily be used now to make an anti-SARS-CoV-2 prophylaxis in areas where vaccines are unavailable, and can be modified to combat future threats from viral epidemics and pandemics.

The Epidemiology of Transfusion-related Acute Lung Injury Varies According to the Applied Definition of Lung Injury Onset Time.

RATIONALE: Research that applies an unreliable definition for transfusion-related acute lung injury (TRALI) may draw false conclusions about its risk factors and biology. The effectiveness of preventive strategies may decrease as a consequence. However, the reliability of the consensus TRALI definition is unknown. OBJECTIVES: To prospectively study the effect of applying two plausible definitions of acute respiratory distress syndrome onset time on TRALI epidemiology. METHODS: We studied 316 adults admitted to the intensive care unit and transfused red blood cells within 24 hours of blunt trauma. We identified patients with acute respiratory distress syndrome, and defined acute respiratory distress syndrome onset time two ways: (1) the time at which the first radiographic or oxygenation criterion was met, and (2) the time both criteria were met. We categorized two corresponding groups of TRALI cases transfused in the 6 hours before acute respiratory distress syndrome onset. We used Cohen's kappa to measure agreement between the TRALI cases and implicated blood components identified by the two acute respiratory distress syndrome onset time definitions. In a nested case-control study, we examined potential risk factors for each group of TRALI cases, including demographics, injury severity, and characteristics of blood components transfused in the 6 hours before acute respiratory distress syndrome onset. MEASUREMENTS AND MAIN RESULTS: Forty-two of 113 patients with acute respiratory distress syndrome were TRALI cases per the first acute respiratory distress syndrome onset time definition and 63 per the second definition. There was slight agreement between the two groups of TRALI cases (κ = 0.16; 95% confidence interval, -0.01 to 0.33) and between the implicated blood components (κ = 0.15, 95% confidence interval, 0.11-0.20). Age, Injury Severity Score, high plasma-volume components, and transfused plasma volume were risk factors for TRALI when applying the second acute respiratory distress syndrome onset time definition but not when applying the first definition. CONCLUSIONS: The epidemiology of TRALI varies when applying two plausible definitions of acute respiratory distress syndrome onset time to severely injured trauma patients. A TRALI definition that standardizes acute respiratory distress syndrome onset time might improve reliability and align efforts to understand epidemiology, biology, and prevention.

Constitutive expression and enzymatic cleavage of ICAM-1 in the spontaneously hypertensive rat.

BACKGROUND/AIMS: Leukocyte adhesion to the endothelium is abnormal in hypertension. We have recently shown that spontaneously hypertensive rats (SHRs) have circulating leukocytes with enhanced CD18 receptor cleavage. In the current study, we investigate expression levels of its counter receptor, intercellular adhesion molecule (ICAM-1), and its possible proteolytic cleavage in the SHR and control Wistar rat. METHODS: ICAM-1 was labeled on tissue sections with two antibodies targeting its extracellular and intracellular domains and evaluated by light absorption measurements. The in situ cleavage of ICAM-1 was assessed by treating vessel sections with matrix metalloproteinase (MMP)-7, MMP-9 and elastase. RESULTS: SHRs showed a significant increase in ICAM-1 expression in liver and kidney compared with Wistar rats. The liver and kidney glomeruli exhibit a discrepancy in label density between intra- and extracellular antibodies, which suggests that enzymatic cleavage may be a factor determining ICAM-1 distribution. MMP-7 and MMP-9, which are elevated in SHR plasma, and elastase, which has elevated activity in SHR neutrophils, cleave the extracellular domain of ICAM-1 when applied to the tissue. CONCLUSION: ICAM-1 expression in SHRs is upregulated in a tissue-specific manner. Proteolytic cleavage of the extracellular domain of ICAM-1 and accumulation in kidney glomeruli may play a role in the renal involvement of inflammation.

Matrix metalloproteinase activity causes VEGFR-2 cleavage and microvascular rarefaction in rat mesentery.

A complication of the spontaneously hypertensive rat (SHR) is microvascular rarefaction, defined by the loss of microvessels. However, the molecular mechanisms involved in this process remain incompletely identified. Recent work in our laboratory suggests that matrix metalloproteinases (MMPs) may play a role by cleavage of the vascular endothelial growth factor receptor 2 (VEGFR-2). In order to further delineate the role for MMPs in microvascular rarefaction, the objective of the current study was to examine the relationship in the same tissue between MMP activity, VEGFR-2 cleavage and rarefaction. Using an in vivo microzymographic technique, we show significantly enhanced levels of MMP-1, -1/-9, -7, and -8 activities, but not MMP-2 and -3 activities, along mesenteric microvessels of the SHR compared to its normotensive control, Wistar Kyoto rat. Based on immunohistochemical methods, the SHR exhibited a decreased labeling of the extracellular, but not the intracellular, domain of VEGFR-2 along mesenteric microvessels. Chronic MMP inhibition served to attenuate VEGFR-2 cleavage and microvascular network rarefaction in the SHR mesentery. These results spatially link MMP-induced VEGFR-2 cleavage and rarefaction in the mesentery of the SHR and thus support the hypothesis that MMPs serve as regulators of microvascular dysfunction in hypertension.

A New Hypothesis for Insulin Resistance in Hypertension Due to Receptor Cleavage.

BACKGROUND: One of the most important unresolved issues in diabetes is the mechanism for the attenuated response to insulin, i.e. insulin resistance. AIMS AND METHODS: We hypothesize that the mechanism for the insulin resistance is due to uncontrolled protease activity in the plasma, on endothelial cells and in the tissue parenchyma. To examine this hypothesis we use of microzymographic techniques in the microcirculation, plasma zymography, and receptor labeling techniques with antibodies against an extracellular domain of the insulin receptor α. RESULTS: The spontaneously hypertensive rat has an enhanced proteolytic activity and significant cleavage of the receptor with attenuated glucose transport. We present evidence for insulin receptor cleavage in a high fat diet and a transgenic model of diabetes. CONCLUSION: These results suggest that cleavage of the extracellular domain of the insulin receptor, a situation that interferes with the ability for insulin to bind and provide an intracellular signal for glucose transport, may be involved in insulin resistance.

Matrix metalloproteinases cleave the beta2-adrenergic receptor in spontaneously hypertensive rats.

We recently observed the enhanced serine and matrix metalloproteinase (MMP) activity in the spontaneously hypertensive rat (SHR) compared with its normotensive Wistar-Kyoto (WKY) rat and the cleavage of membrane receptors in the SHR by MMPs. We demonstrate in vivo that MMP-7 and MMP-9 injection leads to a vasoconstrictor response in microvessels of rats that is blocked by a specific MMP inhibitor (GM-6001, 1 microM). Multiple pathways may be responsible. Since the beta(2)-adrenergic receptor (beta(2)-AR) is susceptible to the action of endogenous MMPs, we hypothesize that MMPs in the plasma of SHRs are able to cleave the extracellular domain of the beta(2)-AR. SHR arterioles respond in an attenuated fashion to beta(2)-AR agonists and antagonists. Aorta and heart muscle of control Wistar rats were exposed for 24 h (37 degrees C) to fresh plasma of male Wistar and WKY rats and SHRs with and without doxycycline (30 microM) and EDTA (10 mM) to reduce MMP activity. The density of extracellular and intracellular domains of beta(2)-AR was determined by immunohistochemistry. The density of the extracellular domain of beta(2)-AR is reduced in aortic endothelial cells and cardiac microvessels of SHRs compared with that of WKY or Wistar rats. Treatment of the aorta and the heart of control Wistar rats with plasma from SHRs, but not from WKY rats, reduced the number of extracellular domains, but not intracellular domains, of beta(2)-AR in aortic endothelial cells and cardiac microvessels. MMP inhibitors (EDTA and doxycycline) prevented the cleavage of the extracellular domain. Thus MMPs may contribute to the reduced density of the extracellular domain of beta(2)-AR in blood vessels and to the increased arteriolar tone of SHRs compared with normotensive rats.

Enhanced matrix metalloproteinase activity in the spontaneously hypertensive rat: VEGFR-2 cleavage, endothelial apoptosis, and capillary rarefaction.

Besides an elevated blood pressure, the spontaneously hypertensive rat (SHR) has multiple microvascular complications including endothelial apoptosis with capillary rarefaction. The SHR also has elevated levels of proteolytic (e.g. matrix metalloproteinase, MMP) activity and apoptosis in microvascular cells compared to its normotensive control, but the specific enzymes involved and the molecular mechanism for apoptosis are unknown. We hypothesize that selected MMPs cleave the extracellular domain of vascular endothelial growth factor receptor-2 (VEGFR-2), which in turn causes endothelial apoptosis and capillary rarefaction. Zymographic analysis shows that gelatinase (MMP-2 and MMP-9) and matrilysin (MMP-7) activities are significantly enhanced in SHR plasma. The SHR has lower levels of the extracellular domains of VEGFR-2 in cardiac microvessels. Furthermore, application of plasma from the SHR, or purified MMP-9 and MMP-7 to naïve cells causes cleavage of the extracellular domain of VEGFR-2. The receptor cleavage was blocked by broad-acting MMP inhibitors (GM6001 1 microM, EDTA 10 mM, or doxycycline 11.3 microM). Chronic MMP inhibition (doxycycline, 5.4 mg/kg/day, 24 weeks) attenuated VEGFR-2 cleavage, endothelial apoptosis, and capillary rarefaction in the SHR. These results suggest elevated plasma MMP activities may cleave VEGFR-2, resulting in endothelial apoptosis and capillary rarefaction in the SHR.

An in-vivo analysis of capillary stasis and endothelial apoptosis in a model of hypertension.

OBJECTIVE: Recent evidence suggests endothelial apoptosis may be a mechanism for capillary rarefaction in hypertensives. The objective of this study was to examine the early phase of endothelial apoptosis and capillary blood flow in the spontaneously hypertensive rat (SHR) and the normotensive Wistar-Kyoto (WKY) rat. METHODS: Since hypertension in SHR is dependent on glucocorticoids, the animals were treated with dexamethasone (DEX), by intraperitoneal injection and then by superfusion on exposed mesentery. Selected capillaries were continuously observed. Annexin V and propidium iodide were used to detect apoptosis. RESULTS: Without central pressure reduction, permanent capillary stasis was initiated by the entrapment of leukocytes at the location of an endothelial cell that had platelets attached to it. Apoptosis of the endothelial cell was followed by apoptosis in other endothelial cells of the obstructed capillary. The incidence of stasis and total cell death in WKY+DEX were higher than WKY, whereas there were no differences between SHR+DEX and SHR. Blockade of the lectin do main of L-selectin or a platelet membrane adhesion molecule (glycoprotein IIb/IIIa) blocked the development of stasis. CONCLUSIONS: Glucocorticoid facilitates cell death and microvessel stasis. Immobilized platelets and leukocytes play a central role in capillary stasis, which leads to progression of endothelial apoptosis.

Microvascular cell death in spontaneously hypertensive rats during experimental inflammation.

OBJECTIVE: Chronic hypertension is associated with an increased risk for tissue injury that may be mediated in part by endothelium and inflammatory cells. To clarify a possible underlying mechanisms, we examined leukocyte migration in the microcirculation and concomitant parenchymal cell death. METHODS: The mesentery of spontaneously hypertensive rats (SHRs) and their normotensive controls, Wistar Kyoto (WKY) rats, was examined with digital fluorescence microscopy after topical stimulation with an inflammatory mediator (f-met-leu-phe, 10(-8)M). The migratory pathways of individual leukocytes were traced, and at the same time cell death was detected by use of a life-death indicator (propidium iodide) over a period of 3 hours. RESULTS: Both WKY and SHR had a progressively increasing number of leukocytes migrating across the endothelium in postcapillary venules into the tissue parenchyma. But parenchymal cell death was detected in a random pattern in the mesentery tissue, without correlation to the migratory positions of the leukocytes. Although mature SHR rats (about 17 weeks) exhibited the same level of cell death as age-matched WKY rats, older WKY rats (about 30 weeks) had significantly lower levels of cell death, whereas the SHR rats maintained the same number of parenchymal cell death as mature animals. CONCLUSIONS: These results suggest that in the presence of an inflammatory mediator, the SHR may exhibit a stronger response to an inflammatory mediator than normotensive WKY rats in a fashion that is age, but not blood pressure, dependent. Parenchymal cell death does not correlate with migration of activated leukocytes at the microvascular level.