Detection of cellular traction forces via the force-triggered Cas12a-mediated catalytic cleavage of a fluorogenic reporter strand

Molecular forces generated by cell receptors are infrequent and transient, and hence difficult to detect. Here we report an assay that leverages the CRISPR-associated protein 12a (Cas12a) to amplify the detection of cellular traction forces generated by as few as 50 adherent cells. The assay involves the immobilization of a DNA duplex modified with a ligand specific for a cell receptor. Traction forces of tens of piconewtons trigger the dehybridization of the duplex, exposing a cryptic Cas12-activating strand that sets off the indiscriminate Cas12-mediated cleavage of a fluorogenic reporter strand. We used the assay to perform hundreds of force measurements using human platelets from a single blood draw to extract individualized dose-response curves and half-maximal inhibitory concentrations for a panel of antiplatelet drugs. For seven patients who had undergone cardiopulmonary bypass, platelet dysfunction strongly correlated with the need for platelet transfusion to limit bleeding. The Cas12a-mediated detection of cellular traction forces may be used to assess cell state, and to screen for genes, cell-adhesion ligands, drugs or metabolites that modulate cell mechanics.

COVID-19 patient fibrinogen produces dense clots with altered polymerization kinetics, partially explained by increased sialic acid

BACKGROUND

Thrombogenicity is a known complication of COVID-19, resulting from SARS-CoV-2 infection, with significant effects on morbidity and mortality.

OBJECTIVE

We aimed to better understand the effects of COVID-19 on fibrinogen and the resulting effects on clot structure, formation, and degradation.

METHODS

Fibrinogen isolated from COVID-19 patients and uninfected subjects was used to form uniformly concentrated clots (2 mg/ml), which were characterized using confocal microscopy, scanning electron microscopy, atomic force microscopy, and endogenous and exogenous fibrinolysis assays. Neuraminidase digestion and subsequent NANA assay were used to quantify sialic acid residue presence; clots made from the desialylated fibrinogen were then assayed similarly to the original fibrinogen clots.

RESULTS

Clots made from purified fibrinogen from COVID-19 patients were shown to be significantly stiffer and denser than clots made using fibrinogen from noninfected subjects. Endogenous and exogenous fibrinolysis assays demonstrated that clot polymerization and degradation dynamics were different for purified fibrinogen from COVID-19 patients compared with fibrinogen from noninfected subjects. Quantification of sialic acid residues via the NANA assay demonstrated that SARS-CoV-2-positive fibrinogen samples contained significantly more sialic acid. Desialylation via neuraminidase digestion resolved differences in clot density. Desialylation did not normalize differences in polymerization, but did affect rate of exogenous fibrinolysis.

DISCUSSION

These differences noted in purified SARS-CoV-2-positive clots demonstrate that structural differences in fibrinogen, and not just differences in gross fibrinogen concentration, contribute to clinical differences in thrombotic features associated with COVID-19. These structural differences are at least in part mediated by differential sialylation.

Validation of an admission coagulation panel for risk stratification of COVID-19 patients

BACKGROUND

There is limited data on the markers of coagulation and hemostatic activation (MOCHA) profile in Coronavirus disease 2019 (COVID-19) and its ability to identify COVID-19 patients at risk for thrombotic events and other complications.

METHODS

Hospitalized patients with confirmed SARS-COV-2 from four Atlanta hospitals were included in this observational cohort study and underwent admission testing of MOCHA parameters (plasma d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex, fibrin monomer). Clinical outcomes included deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke, access line thrombosis, ICU admission, intubation and mortality.

MAIN RESULTS

Of 276 patients (mean age 59 ± 6.4 years, 47% female, 62% African American), 45 (16%) had a thrombotic endpoint. Each MOCHA parameter was independently associated with a thrombotic event (p<0.05) and ≥ 2 abnormalities was associated with thrombotic endpoints (OR 3.3, 95% CI 1.2-8.8) as were admission D-dimer ≥ 2000 ng/mL (OR 3.1, 95% CI 1.5-6.6) and ≥ 3000 ng/mL (OR 3.6, 95% CI 1.6-7.9). However, only ≥ 2 MOCHA abnormalities were associated with ICU admission (OR 3.0, 95% CI 1.7-5.2) and intubation (OR 3.2, 95% CI 1.6-6.4). MOCHA and D-dimer cutoffs were not associated with mortality. MOCHA with <2 abnormalities (26% of the cohort) had 89% sensitivity and 93% negative predictive value for a thrombotic endpoint.

CONCLUSIONS

An admission MOCHA profile is useful to risk-stratify COVID-19 patients for thrombotic complications and more effective than isolated d-dimer for predicting risk of ICU admission and intubation.

Feasibility of Auricular Field Stimulation in Fibromyalgia: Evaluation by Functional Magnetic Resonance Imaging, Randomized Trial

OBJECTIVE

To evaluate the feasibility of recruitment, preliminary efficacy, and acceptability of auricular percutaneous electrical nerve field stimulation (PENFS) for the treatment of fibromyalgia in veterans, using neuroimaging as an outcome measure and a biomarker of treatment response.

DESIGN

Randomized, controlled, single-blind.

SETTING

Government hospital.

SUBJECTS

Twenty-one veterans with fibromyalgia were randomized to standard therapy (ST) control or ST with auricular PENFS treatment.

METHODS

Participants received weekly visits with a pain practitioner over 4 weeks. The PENFS group received reapplication of PENFS at each weekly visit. Resting-state functional connectivity magnetic resonance imaging (rs-fcMRI) data were collected within 2 weeks prior to initiating treatment and 2 weeks following the final treatment. Analysis of rs-fcMRI used a right posterior insula seed. Pain and function were assessed at baseline and at 2, 6, and 12 weeks post-treatment.

RESULTS

At 12 weeks post-treatment, there was a nonsignificant trend toward improved pain scores and significant improvements in pain interference with sleep among the PENFS treatment group as compared with the ST controls. Neuroimaging data displayed increased connectivity to areas of the cerebellum and executive control networks in the PENFS group as compared with the ST control group following treatment.

CONCLUSIONS

There was a trend toward improved pain and function among veterans with fibromyalgia in the ST + PENFS group as compared with the ST control group. Pain and functional outcomes correlated with altered rs-fcMRI network connectivity. Neuroimaging results differed between groups, suggesting an alternative underlying mechanism for PENFS analgesia.

Fibrinolysis Shutdown and Thrombosis in a COVID-19 ICU

ABSTRACT

The coronavirus disease (COVID-19) pandemic has threatened millions of lives worldwide with severe systemic inflammation, organ dysfunction, and thromboembolic disease. Within our institution, many critically ill COVID-19-positive patients suffered major thrombotic events, prompting our clinicians to evaluate hypercoagulability outside of traditional coagulation testing.We determined the prevalence of fibrinolysis shutdown via rotational thromboelastometry (ROTEM, Instrumentation Laboratories, Bedford, Mass) in patients admitted to the intensive care unit over a period of 3 weeks. In 25 patients who had a ROTEM test, we found that 11 (44%) met criteria for fibrinolysis shutdown. Eight of 9 (73%) of the VTE patients met criteria for fibrinolysis shutdown.Given the high rate of fibrinolysis shutdown in these patients, our data support using viscoelastic testing to evaluate for the presence of impaired fibrinolysis. This may help identify patient subsets who might benefit from the administration of fibrinolytics.

Abstract P112: Markers of Coagulation and Hemostatic Activation Identify Covid-19 Patients at High Risk for Thrombotic Events

Introduction: COVID-19 has been associated with venous and arterial thrombotic complications. The objective of our study was to determine whether markers of coagulation and hemostatic activation (MOCHA) on admission could identify COVID-19 patients at risk for thrombotic events.

Methods: COVID-19 patients admitted to a tertiary academic healthcare system from April 3, 2020 to July 31, 2020 underwent admission testing of MOCHA profile parameters (plasma d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex, and fibrin monomer). For this analysis we excluded patients on outpatient anticoagulation therapy preceding admission. Prespecified endpoints monitored during hospitalization included deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke and access line thrombosis.

Results: During the study period, 276 patients were included in the analysis cohort (mean age 59 ± 6.3 years, 47% female, 83% non-white race). Arterial and venous thrombotic events occurred in 43 (16%) patients (see Table). Each coagulation marker was independently associated with the composite endpoint (p<0.05). Admission MOCHA with ≥ 2 abnormalities was associated with the composite endpoint (OR 3.1, 95% CI 1.2-8.3), ICU admission (OR 3.2, 95% CI 1.8-5.5) and intubation (OR 2.8, 95% CI 1.5-5.5). Admission MOCHA with < 2 abnormalities (26% of the cohort) had sensitivity of 88% and a negative predictive value of 93% for an in-hospital endpoint.

Conclusion: Admission MOCHA with ≥ 2 abnormalities identified COVID-19 patients at risk for a thrombotic event, ICU admission and intubation while < 2 abnormalities identified a subgroup of patients who were at low risk for thrombotic events. Our results suggest that an admission MOCHA profile can be useful to risk stratify COVID-19 patients. Further studies are needed to determine whether an admission MOCHA profile can guide anticoagulation therapy and improve overall clinical outcomes.

Clinical Outcomes of Critically III Patients with COVID-19 by Race

Background

Studies of COVID-19 have shown that African Americans have been affected by the virus at a higher rate compared to other races. This cohort study investigated comorbidities and clinical outcomes by race among COVID-19 patients admitted to the intensive care unit.

Methods

This is a case series of critically ill patients admitted with COVID-19 to an academic healthcare system in Atlanta, Georgia. The study included all critically ill hospitalized patients between March 6, 2020, and May 5, 2020. Clinical outcomes during hospitalization included mechanical ventilation, renal replacement therapy, and mortality stratified by race.

Results

Of 288 patients included (mean age, 63 ± 16 years; 45% female), 210 (73%) were African American. African Americans had significantly higher rates of comorbidities compared to other races, including hypertension (80% vs 59%, P = 0.001), diabetes (49% vs 34%, P = 0.026), and mean BMI (33 kg/m² vs 28 kg/m², P < 0.001). Despite African Americans requiring continuous renal replacement therapy during hospitalization at higher rates than other races (27% vs 13%, P = 0.011), rates of intubation, intensive care unit length of stay, and overall mortality (30% vs 24%, P = 0.307) were similar.

Conclusion

This racially diverse series of critically ill COVID-19 patients shows that despite higher rates of comorbidities at hospital admission in African Americans compared with other races, there was no significant difference in mortality.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40615-021-00966-0.

Concerns of Patients With Cancer on Accessing Cannabis Products in a State With Restrictive Medical Marijuana Laws: A Survey Study

PURPOSE

Several states, particularly in the Southeast, have restrictive medical marijuana laws that permit qualified patients to use specific cannabis products. The majority of these states, however, do not provide avenues for accessing cannabis products such as in-state dispensaries.

METHODS

We conducted a survey of patients registered for medical marijuana (low tetrahydrocannabinol [THC] oil cards) in an ambulatory palliative care practice in Georgia (one of the states with restrictive medical marijuana laws).

RESULTS

We had a total of 101 responses. Among our sample of patients who use cannabis as part of a state-approved low THC oil program, 56% were male and 64% were older than age 50 years. Advanced cancer was the most common reason (76%) for granting the patients access to a low THC oil card. Although patients reported cannabis products as being extremely helpful for reducing pain, they expressed considerable concerns about the legality issues (64%) and ability to obtain THC (68%). Several respondents were using unapproved formulations of cannabis products. For 48% of the patients, their physician was the source of information regarding marijuana-related products. Furthermore, they believed that their health care providers and family members were supportive of their use of cannabis (62% and 79%, respectively).

CONCLUSION

Patients on Georgia's medical marijuana program are most concerned about the legality of the product and their ability to obtain marijuana-related products. Therefore, we recommend that states with medical marijuana laws should provide safe and reliable access to cannabis products for qualifying patients.

Perception of Benefits and Harms of Medical Cannabis among Seriously Ill Patients in an Outpatient Palliative Care Practice

Introduction: Patients with serious illness often have pain, uncontrolled symptoms, and poor quality of life. Evidence continues to evolve regarding the role of cannabis to treat chronic pain, nausea, and anorexia. Little is known about how patients with serious illness perceive its benefits and harms. Given that an increasing number of clinicians across the United States are treating patients with medical cannabis, it is important for providers to understand patient beliefs about this modality. We assessed patient perceptions of benefits and harms of cannabis who obtained a medical cannabis card within an ambulatory palliative care (APC) practice. Methods: We recruited patients with a medical cannabis card, allowing for legal possession of cannabis oil, from an APC practice in Georgia. All participants reported using cannabis products. Patients completed an online survey that included questions about their cannabis use, concurrent opiate or controlled medication use, and perceptions of benefits and harms of cannabis. Results: All 101 patients invited to participate completed the survey. A majority had cancer (76%) and were married (61%), disabled or retired (75%), older than 50 years of age (64%), and men (56%). Most patients ingested (61%) or vaporized (49%) cannabis products. A majority of respondents perceived cannabis to be important for their pain (96%) management. They reported that side effects were minimally bothersome, and drowsiness was the most commonly reported bothersome harm (28%). A minority of patients reported cannabis withdrawal symptoms (19%) and concerns for dependency (14%). The majority of patients were using concurrent prescription opioids (65%). Furthermore, a majority of cancer patients reported cannabis as being important for cancer cure (59%). Conclusion: Patients living with serious illnesses who use cannabis in the context of a multidisciplinary APC practice use cannabis for curative intent and for pain and symptom control. Patients reported improved pain, other symptoms, and a sense of well-being with few reported harms.

Functional Magnetic Resonance Imaging Evaluation of Auricular Percutaneous Electrical Neural Field Stimulation for Fibromyalgia: Protocol for a Feasibility Study

Background

Fibromyalgia is a chronic pain state that includes widespread musculoskeletal pain, fatigue, psychiatric symptoms, cognitive and sleep disturbances, and multiple somatic symptoms. Current therapies are often insufficient or come with significant risks, and while there is an increasing demand for non-pharmacologic and especially non-opioid pain management such as that offered through complementary and alternative medicine therapies, there is currently insufficient evidence to recommend these therapies. Percutaneous electrical neural stimulation (PENS) is an evidence-based treatment option for pain conditions that involves electrical current stimulation through needles inserted into the skin. Percutaneous electrical neural field stimulation (PENFS) of the auricle is similar to PENS, but instead of targeting a single neurovascular bundle, PENFS stimulates the entire ear, covering all auricular branches of the cranial nerves, including the vagus nerve. The neural mechanisms of PENFS for fibromyalgia symptom relief are unknown.

Objective

We hypothesize that PENFS treatment will decrease functional brain connectivity between the default mode network (DMN) and right posterior insula in fibromyalgia patients. We expect that the decrease in functional connectivity between the DMN and insula will correlate with patient-reported analgesic improvements as indicated by the Defense and Veterans Pain Rating Scale (DVPRS) and will be anti-correlated with patient-reported analgesic medication consumption. Exploratory analyses will be performed for further hypothesis generation.

Methods

A total of 20 adults from the Atlanta Veterans Affairs Medical Center diagnosed with fibromyalgia will be randomized into 2 groups: 10 subjects to a control (standard therapy) group and 10 subjects to a PENFS treatment group. The pragmatic, standard therapy group will include pharmacologic treatments such as anticonvulsants, non-steroidal anti-inflammatory drugs, topical agents and physical therapy individualized to patient comorbidities and preferences, prescribed by a pain management practitioner. The PENFS group will include the above therapies in addition to the PENFS treatments. The PENFS subject group will have the Neuro-Stim System placed on the ear for 5 days then removed and replaced once per week for 4 weeks. The primary outcome will be resting functional magnetic resonance imaging connectivity between DMN and insula, which will also be correlated with pain relief and functional improvements. This connectivity will be analyzed utilizing functional connectivity magnetic resonance imaging (fcMRI) and will be compared with patient-reported analgesic improvements as indicated by the DVPRS and patient-reported analgesic medication consumption. Pain and function will be further evaluated using Patient-Reported Outcomes Measurement Information System measures and measures describing a person’s functional status from Activity and Participation section of the International Classification of Functioning Disability and Health.

Results

This trial has been funded by the Veterans Health Administration Program Office. This study attained approval by the Emory University/Veterans Affairs (VA) institutional review board and VA Research & Development committee. Institutional review board expedited approval was granted on 2/7/17 (IRB00092224). The study start date is 6/1/17 and estimated completion date is 5/31/20. The recruitment started in June 2017.

Conclusions

This is a feasibility study that is meant to demonstrate the practicality of using fcMRI to study the neural correlates of PENFS outcomes and provide information regarding power calculations in order to design and execute a larger randomized controlled clinical trial to determine the efficacy of PENFS for improving pain and function.

Trial Registration

ClinicalTrials.gov NCT03008837; https://clinicaltrials.gov/ct2/show/NCT03008837 (Archived by WebCite at http://www.webcitation.org/6wrY3NmaQ).

Garlic-Induced Surgical Bleeding: How Much Is Too Much?

A patient underwent C2-T2 decompression and fusion with excessive intraoperative bleeding and no clear source. The patient denied the use of blood-thinning medications, but had consumed the equivalent of 12 g garlic daily in the days leading up to the surgery. He was treated with desmopressin acetate (DDAVP) and cryoprecipitate with adequate control of bleeding. Garlic is known to have an antiplatelet effect, although the dose range necessary to create a bleeding abnormality has not yet been well described nor has the effect of taking garlic with sertraline or other agents with an established or potential effect on coagulation.

Reduced efficacy of volatile anesthetic preconditioning with advanced age in isolated rat myocardium

BACKGROUND

Ischemic preconditioning and anesthetic preconditioning (APC) are reported to decrease myocardial infarct size during ischemia-reperfusion injury. However, the beneficial effects of ischemic preconditioning have been shown to decrease with advancing age. Although the mechanisms of ischemic preconditioning and APC are thought to be similar, it is not known whether the beneficial effects of APC are also reduced in the aged myocardium.

METHODS

Male Fischer 344 rats of three age groups (2-4, 10-12, and 20-24 months) were used. Hearts were Langendorff perfused. Six hearts in each age group were pretreated with 10 min of sevoflurane and a 5-min washout before 25 min of ischemia and 60 min of reperfusion. Six control hearts in each age group received no treatment before ischemia. Nuclear magnetic resonance was used to measure intracellular Na, intracellular Ca, and intracellular pH, respectively. Left ventricular developed pressure, creatine kinase, and infarct size were measured.

RESULTS

Ischemia decreases intracellular pH and increases intracellular Na and intracellular Ca in all age groups. APC blunts the pH decreases in young adult and middle-aged rats, but not in aged rats. APC decreased intracellular Na and intracellular Ca accumulation during ischemia in young adult and middle-aged hearts. APC improved adenosine triphosphate recovery in young rats but not in aged rats. Creatine kinase and infarct sizes were significantly reduced and left ventricular developed pressure was improved with APC in the young adult and middle-aged groups but not the aged group.

CONCLUSIONS

The benefits of APC are significantly reduced with advanced age in an isolated rat heart model.