Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

The 3D-McMap Guidelines: Three-Dimensional Multicomposite Microsphere Adaptive Printing

Microspheres, synthesized from diverse natural or synthetic polymers, are readily utilized in biomedical tissue engineering to improve the healing of various tissues. Their ability to encapsulate growth factors, therapeutics, and natural biomolecules, which can aid tissue regeneration, makes microspheres invaluable for future clinical therapies. While microsphere-supplemented scaffolds have been investigated, a pure microsphere scaffold with an optimized architecture has been challenging to create via 3D printing methods due to issues that prevent consistent deposition of microsphere-based materials and their ability to maintain the shape of the 3D-printed structure. Utilizing the extrusion printing process, we established a methodology that not only allows the creation of large microsphere scaffolds but also multicomposite matrices into which cells, growth factors, and therapeutics encapsulated in microspheres can be directly deposited during the printing process. Our 3D-McMap method provides some critical guidelines for issues with scaffold shape fidelity during and after printing. Carefully timed breaks, minuscule drying steps, and adjustments to extrusion parameters generated an evenly layered large microsphere scaffold that retained its internal architecture. Such scaffolds are superior to other microsphere-containing scaffolds, as they can release biomolecules in a highly controlled spatiotemporal manner. This capability permits us to study cell responses to the delivered signals to develop scaffolds that precisely modulate new tissue formation.

Extended duration letermovir in allogeneic hematopoietic stem cell transplant

OBJECTIVES

Despite the use of antiviral prophylaxis in recipients of allogeneic hematopoietic cell transplants (HCT), cytomegalovirus (CMV) is a common clinically significant infection and is associated with significant morbidity and mortality in this patient population. Based on current approval, letermovir is initiated within 28 days following allogeneic HCT for CMV seropositive recipients and continued through 100 days post-transplant. However, it is unknown whether patients who receive extended duration CMV prophylaxis with letermovir would result in less CMV reactivation and reactivation compared to those who do not. This study aimed to evaluate the efficacy of letermovir prophylaxis in CMV seropositive patients when continued for greater than 100 days post-allogeneic stem cell transplant.

METHODS

A single-center retrospective chart review was conducted on recipients of allogeneic HCT from November 2017 to July 2021. Patients were eligible for inclusion if they were at least 18 years of age, received an allogeneic HCT, CMV seropositive, and initiated letermovir between days 0-28 post-transplant. The primary endpoint of this study is to compare rates of CMV reactivation in patients who stopped letermovir prophylaxis at 100 days post-transplant (standard duration group) versus those who continued letermovir prophylaxis past day 100 (extended duration group).

RESULTS

A total of 87 patients met the eligibility criteria for inclusion. The median duration of letermovir prophylaxis was 78 days in the standard duration group versus and 132 days in the extended duration group. There were more CMV reactivations in the standard duration group versus the extended duration group, 28% versus 19% respectively. CMV pneumonitis was observed in one of the patients in the standard duration group. All-cause mortality at day 200 post-transplant was similar between the two groups.

CONCLUSION

The results of this study suggest that extended duration letermovir prophylaxis may be associated with less CMV reactivation compared to the standard duration of prophylaxis.

Ceramides Increase Fatty Acid Utilization in Intestinal Progenitors to Enhance Stemness and Increase Tumor Risk

BACKGROUND & AIMS

Cancers of the alimentary tract, including esophageal adenocarcinomas, colorectal cancers, and cancers of the gastric cardia, are common comorbidities of obesity. Prolonged, excessive delivery of macronutrients to the cells lining the gut can increase one's risk for these cancers by inducing imbalances in the rate of intestinal stem cell proliferation vs differentiation, which can produce polyps and other aberrant growths. We investigated whether ceramides, which are sphingolipids that serve as a signal of nutritional excess, alter stem cell behaviors to influence cancer risk.

METHODS

We profiled sphingolipids and sphingolipid-synthesizing enzymes in human adenomas and tumors. Thereafter, we manipulated expression of sphingolipid-producing enzymes, including serine palmitoyltransferase (SPT), in intestinal progenitors of mice, cultured organoids, and Drosophila to discern whether sphingolipids altered stem cell proliferation and metabolism.

RESULTS

SPT, which diverts dietary fatty acids and amino acids into the biosynthetic pathway that produces ceramides and other sphingolipids, is a critical modulator of intestinal stem cell homeostasis. SPT and other enzymes in the sphingolipid biosynthesis pathway are up-regulated in human intestinal adenomas. They produce ceramides, which serve as prostemness signals that stimulate peroxisome-proliferator activated receptor-α and induce fatty acid binding protein-1. These actions lead to increased lipid utilization and enhanced proliferation of intestinal progenitors.

CONCLUSIONS

Ceramides serve as critical links between dietary macronutrients, epithelial regeneration, and cancer risk.

Mycobacterial formation of intracellular lipid inclusions is a dynamic process associated with rapid replication

Intracellular lipid inclusions (ILI) are triacylglyceride rich organelles produced by mycobacteria thought to serve as energy reservoirs. It is believed that ILI are formed as a result of a dosR mediated transition from replicative growth to non-replicating persistence (NRP). ILI rich Mycobacterium tuberculosis (Mtb) bacilli have been reported during infection and in sputum, establishing their importance in Mtb pathogenesis. Studies conducted in mycobacteria such as Mycobacterium smegmatis, Mycobacterium abscessus, or lab Mtb strains have demonstrated ILI formation in the presence of hypoxic, nitric oxide, nutrient limitation, or low nitrogen stress, conditions believed to emulate the host environment within which Mtb resides. Here, we show that M. marinum and clinical Mtb isolates make ILI during active replication in axenic culture independent of environmental stressors. By tracking ILI formation dynamics we demonstrate that ILI are quickly formed in the presence of fresh media or exogenous fatty acids but are rapidly depleted while bacteria are still actively replicating. We also show that the cell envelope is an alternate site for neutral lipid accumulation observed during stationary phase. In addition, we screen a panel of 60 clinical isolates and observe variation in ILI production during early log phase growth between and among Mtb lineages. Finally, we show that dosR expression level does not strictly correlate with ILI accumulation in fresh clinical isolates. Taken together, our data provide evidence of an active ILI formation pathway in replicating mycobacteria cultured in the absence of stressors, suggesting a decoupling of ILI formation from NRP.

A79 THE RELATIONSHIP BETWEEN VISCERAL ADIPOSITY AND NONALCOHOLIC FATTY LIVER DISEASE DIAGNOSED BY CONTROLLED ATTENUATION PARAMETER IN PEOPLE WITH HIV: A PILOT STUDY

Background

Aging people with HIV (PWH) on antiretroviral therapy face high rates of metabolic dysfunction and nonalcoholic fatty liver disease (NAFLD). Fat alterations are frequent in PWH and predict worse cardiometabolic outcomes. Visceral adipose tissue (VAT) is an important compartment of body fat tissue releasing bioactive molecules. As a hormonally active tissue, VAT critically contributes to obesity-related disorders and is associated with ectopic fat accumulation in the liver.

Purpose

We aimed to investigate NAFLD diagnosed by controlled attenuation parameter (CAP) as a marker of visceral adiposity in PWH.

Method

We conducted a prospective pilot study (ClinicalTrials.gov 2021-6656) of HIV mono-infected patients undergoing metabolic characterization and paired CAP by transient elastography with dual-energy X-ray absorptiometry (DEXA) scan. NAFLD was defined as CAP ≥285 dB/m, in absence of alcohol abuse. Excess visceral adiposity was defined as VAT>1.32 Kg. Pairwise correlation, area under the curve (AUC) and logistic regression analysis were employed to study the association between VAT and CAP.

Result(s)

30 patients (90% male, mean age 48.5, mean BMI 29.9, mean waist circumference 100.9, 50% with NAFLD) were included. When compared to those without excess VAT, PWH with excess VAT were older (53+12 vs 43+13 years, p=0.035), had longer duration of HIV infection (20+13 vs. 9+9 years, p=0.021), had higher BMI (32+4 vs 27+4 Kg/m², p=0.002) and waist circumference (107+11 vs. 93+12 cm, p=0.004). They also had more history of cardiovascular events (29% vs. 0, p=0.032) and higher lipid accumulation product, a marker of lipid accumulation based on waist circumference and triglycerides (112+53 vs. 38+27, p<0.001). CAP was higher in PWH with excess VAT (319+52 vs. 213+52 dB/m, p<0.001). CAP positively correlated with all visceral fat measurements by DEXA, including VAT (r=0.650, p<0.001), VAT/body weight ratio (r=0.565, p=0.001) and fat mass (r=0.390, p=0.033). Both BMI and waist circumference showed correlation with VAT and fat mass, but not with VAT/body weight ratio (see Figure). After adjusting for duration of HIV infection (aOR 1.01 per year, 95% CI 0.91-1.12; p=0.921), BMI (aOR 1.77, 95% CI 0.74-4.23; p=0.202) and waist circumference (aOR 0.91 per cm, 95% 0.68-1.21; p=0.509), CAP remained the only independent predictor of excess VAT (aOR 1.05 per dB/m, 95% CI 1.01-1.10; p=0.036). The AUC analysis determined CAP had excellent performance to diagnose excess VAT (AUC 0.92, 95% CI 0.81-1.00), higher than BMI (AUC 0.83, 95% CI 0.68-0.99) and waist circumference (AUC 0.81, 95% CI 0.65-0.97). The optimized CAP cut-off to diagnose excess VAT was 266 dB/m, with a sensitivity of 88.3% and a specificity of 84.6%.

Image

Conclusion(s)

NAFLD diagnosed by CAP is associated with VAT in PWH independently of anthropometric measures of obesity. CAP could be used as a diagnostic marker of visceral adiposity in the practice of HIV medicine

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CanHepC

Disclosure of Interest

W. Elgretli Grant / Research support from: CanHepC, N. Paisible: None Declared, C. Costiniuk: None Declared, J. Cox: None Declared, D. Kablawi: None Declared, M. Klein: None Declared, N. Kronfli: None Declared, J.-P. Routy: None Declared, J. Falutz: None Declared, B. Lebouche: None Declared, G. Guaraldi: None Declared, G. Sebastiani: None Declared

PERM1 regulates energy metabolism in the heart via ERRα/PGC-1α axis

Aims

PERM1 is a striated muscle-specific regulator of mitochondrial bioenergetics. We previously demonstrated that PERM1 is downregulated in the failing heart and that PERM1 positively regulates metabolic genes known as targets of the transcription factor ERRα and its coactivator PGC-1α in cultured cardiomyocytes. The aims of this study were to determine the effect of loss of PERM1 on cardiac function and energetics using newly generated Perm1-knockout (Perm1 -/-) mice and to investigate the molecular mechanisms of its transcriptional control.

Methods and results

Echocardiography showed that ejection fraction and fractional shortening were lower in Perm1 -/- mice than in wild-type mice (both p < 0.05), and the phosphocreatine-to-ATP ratio was decreased in Perm1 -/- hearts (p < 0.05), indicating reduced contractile function and energy reserves of the heart. Integrated proteomic and metabolomic analyses revealed downregulation of oxidative phosphorylation and upregulation of glycolysis and polyol pathways in Perm1 -/- hearts. To examine whether PERM1 regulates energy metabolism through ERRα, we performed co-immunoprecipitation assays, which showed that PERM1 bound to ERRα in cardiomyocytes and the mouse heart. DNA binding and reporter gene assays showed that PERM1 was localized to and activated the ERR target promoters partially through ERRα. Mass spectrometry-based screening in cardiomyocytes identified BAG6 and KANK2 as potential PERM1's binding partners in transcriptional regulation. Mammalian one-hybrid assay, in which PERM1 was fused to Gal4 DNA binding domain, showed that the recruitment of PERM1 to a gene promoter was sufficient to activate transcription, which was blunted by silencing of either PGC-1α, BAG6, or KANK2.

Conclusion

This study demonstrates that PERM1 is an essential regulator of cardiac energetics and function and that PERM1 is a novel transcriptional coactivator in the ERRα/PGC-1α axis that functionally interacts with BAG6 and KANK2.

Diagnosis of venous thromboembolism in pregnancy: a review of current guidelines

Venous thromboembolic disease (VTE) is the leading cause of maternal death throughout the developed world. International and national guidance for the diagnosis and management of VTE in pregnancy is varied and limited, which can result in problems in clinical practice. The imaging challenges of VTE in the general population are challenging but become more complex in pregnancy due to the physiological changes in the circulatory system, which alter clinical judgment and test performance. As an additional factor, the relative radiation risks to the mother and fetus arising from diagnostic tests need to be assessed and communicated to the patient in a clear and understandable way. The purpose of this review is fourfold. We propose to review and summarise the current imaging guidelines available for this condition; critically review the evidence base within the current literature; address the issues of test performance of imaging examinations used for VTE in pregnancy; and address the question of radiation risk and how to communicate this information to patients.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

P-698 Pituitary functioning gonadotroph adenomas (FGA)-induced ovarian hyperstimulation syndrome (OHSS): results from tertiary neuroendocrine centres in the UK

Study question

There are no published series of OHSS due to FGA. What FGA features should clinicians look for during OHSS, and what treatments are effective?

Summary answer

FGA tumour size is always &gt;10mm. Other pituitary hormones may be deficient. Surgical resection of FGA is an effective treatment for OHSS.

What is known already

Pituitary adenomas affect 1:1000 adults and are classified as functioning or non-functioning. Non-functioning pituitary adenomas do not secrete hormones, but most commonly stain histologically gonadotroph cells. Functional pituitary adenomas secrete hormones such as prolactin causing prolactinoma. However, it is rare for a pituitary tumour to cause clinical features of excessive gonadotrophins (functioning gonadotroph adenoma; FGA).

Single case reports, but no case series, have been published on the presentation of FGA-induced OHSS in women.

Surgical excision of adenomas has been reported to cause remission of symptoms, though systematic data are lacking owing to rarity of these tumours.

Study design, size, duration

National case series from tertiary neuroendocrine units in England, Wales and Scotland.

Participants/materials, setting, methods

Eight high-volume pituitary endocrine tertiary units within England, Wales and Scotland audited their records for any cases of FGA-induced OHSS; only seven patients have been identified to date. In all cases, there had been no recent exposure to assisted reproductive technologies (ART) or drugs known to induce OHSS including gonadotrophins or selective oestrogen receptor modulators (SERMS).

Main results and the role of chance

Seven cases of FGA were identified with mean age 31.6 years (range 16-48) at diagnosis. Two-of-seven women presented acutely unwell with abdominal pain, distention and palpable mass requiring oophorectomy for ovarian torsion/ruptured ovarian cyst. The remaining five women presented with abdominal pain (n = 2), thyrotoxicosis (n = 1), menstrual irregularities/galactorrhoea (n = 1) and visual disturbances (n = 1). All women experienced intermittent pelvic pain during medical attendance. Pelvic ultrasound demonstrated enlarged multiseptated ovaries (volume ranging 27-442cm3). Ascites was noted in one woman. Six women had visual field defects due to optic chiasm compression on formal assessment. Median FSH was 26.10 u/L (8.3-33), but LH was &lt;2.5 u/L in all cases. Estradiol (E2) far exceeded the reference range in 5/7 women (2990 to &gt; 18000pmol/L);E2 was at the upper limit of normal in the remaining 2/7 women (960-1450pmol/L). Hyperprolactinaemia, hyperthyroidism and other pituitary hormones deficiency were noted in 6/7, 1/7 and 4/7 women respectively. All FGAs were macroadenomas with diameters ranging 16-48mm. Two patients were administered a somatostatin analogue prior to surgery, but FSH, E2 and tumour size did not change. Transsphenoidal surgery was performed in 6/7 women, and always improved symptomatic and biochemical features of OHSS; however, residual FGA tumour was present post-operatively in all cases studied.

Limitations, reasons for caution

It is possible that some ‘non-functioning’ gonadotroph adenomas cause subclinical problems including menstrual irregularity and mild OHSS which were never diagnosed.

We have insufficient data to determine the prognosis for future pregnancy after FGA-induced OHSS.

This study utilised historical case-notes, so some data is missing.

Wider implications of the findings

The ‘spontaneous’ presentation of OHSS may be confusing for clinicians. We report that FGA is an important cause of spontaneous OHSS which has well-defined biochemical and radiological characteristics, which may be treated effectively in the short-to-medium with pituitary surgery. Results of this study may provide greater awareness of FGA-induced OHSS.

Trial registration number

N/A

AB0060 SYSTEMIC INFLAMMATORY EFFECT ON HIPPOCAMPAL VOLUME IN RHEUMATOID ARTHRITIS AND ULCERATIVE COLITIS

Background

Autoimmune diseases represent a large and heterogeneous group of disorders that afflict specific target organs. However, multiple factors point to common links between the differing presentations of autoimmune disorders.

With increased interest in further understanding the neuro-immune axis, autoimmune diseases represent an important opportunity to explore whether systemic inflammation from these autoimmune pathways has a central effect and, if so, whether there is a common or discrete central effect caused by different autoimmune diseases.

Objectives

The present study aimed to analyse hippocampal volume in patients with rheumatoid arthritis (RA) and ulcerative colitis (UC) as compared to healthy control groups. The hippocampus was chosen as a region of interest given the regulatory role it exhibits in the hypothalamic–pituitary–adrenal (HPA) axis2. Additionally, the hippocampus has been identified as a region that is affected in other autoimmune diseases such as systemic lupus erythematosus (SLE).

Methods

Data from 1,040 individuals in the UKBiobank Imaging sub-study were included in the present study. This was divided into two separate patient populations with separate control groups. Data from 267 individuals (mean age ± SD =65.52 ± 7.02, 70.8% females) were included in the RA patient group with 267 age and sex matched controls (mean age ± SD = 65.51 ± 7, 70.8% females). Data from 253 individuals (mean age ± SD = 64.09 ± 7.03, 51.6% females) were included in the UC patient group with 253 age and sex matched controls (mean age ± SD = 63.4 ± 7.02, 51.6% females).

The UKBiobank is a prospective observational study with a proposed cohort of 500,000 participants. The imaging substudy is planned to scan 100,000 of those participants with a standardised scanning protocol including MRI of the brain. Multi-modal images were acquired on a 3T scanner3. From the T1w data, volumetric imaging derived phenotypes (IDPs) are provided using the FMRIB Integrated Registration and Segmentation Tool (FIRST); http://fsl.fmrib.ox.ac.uk/fsl/fslwiki/FIRST. This study utilised the right and left hippocampal volume outputs from that tool.

Results

We observed a smaller hippocampal volume in UC patients when compared to healthy controls (difference right: 99.78 mm3, SD ± 38.97, p = 0.01; left: 74.30 mm3, SD ± 39.41, p = 0.06). The Cohen’s effect size was d = -0.24 [95% CI -0.43, -0.05] for right hippocampal volume and d = -0.18 [95% CI -0.36, 0.00] for left hippocampal volume.

Figure 1.

Right and left hippocampal volume in UC patients versus controls and right and left hippocampal volume in RA patients versus controls.

There was no significant difference seen in hippocampal volume in RA patients compared to controls (difference right: 61.32 mm3, SD ± 40.33, p = 0.13; left: 39.00 mm3, SD ± 38.19, p = 0.31). The Cohen’s effect size was d = -0.12 [95% CI -0.30, 0.06] for right hippocampal volume and d = -0.08 [95% CI -0.27, 0.10] for left hippocampal volume.

Conclusion

This study provides evidence of moderate reduction in hippocampal volumes in patients with ulcerative colitis as compared to age and sex matched healthy controls. This same effect was not seen in a similarly matched rheumatoid arthritis patient population. Further analysis of additional subcortical regions could provide further context for whether there are alternative regions affected in both RA and UC.

References

[1]Bellavance, M.A, Rivest, S., (2014), ‘The HPA – immune axis and the immunomodulatory actions of glucocorticoids in the brain’, Frontiers in Immunology, vol, 5, pp 136.

[2]Miller, K.L., Alfaro-Almagro, F., Bangerter, N.K. et al. (2016), ‘Multimodal Multimodal population brain imaging in the UK Biobank prospective epidemiological study’, Nature Neuroscience, vol. 19, pp. 1523-1536.

Disclosure of Interests

Jennifer Cox Grant/research support from: PhD funded by GlaxoSmithKline, Employee of: Former employee of GlaxoSmithKline, Marius de Groot Shareholder of: Employee of GlaxoSmithKline, Employee of: Employee of GlaxoSmithKline, James Cole: None declared, Steven Williams: None declared

Cordyceps inhibits ceramide biosynthesis and improves insulin resistance and hepatic steatosis

Ectopic ceramide accumulation in insulin-responsive tissues contributes to the development of obesity and impairs insulin sensitivity. Moreover, pharmacological inhibition of serine palmitoyl transferase (SPT), the first enzyme essential for ceramide biosynthesis using myriocin in rodents reduces body weight and improves insulin sensitivity and associated metabolic indices. Myriocin was originally extracted from fruiting bodies of the fungus Isaria sinclairii and has been found abundant in a number of closely related fungal species such as the Cordyceps. Myriocin is not approved for human use but extracts from Cordyceps are routinely consumed as part of traditional Chinese medication for the treatment of numerous diseases including diabetes. Herein, we screened commercially available extracts of Cordyceps currently being consumed by humans, to identify Cordyceps containing myriocin and test the efficacy of Cordyceps extract containing myriocin in obese mice to improve energy and glucose homeostasis. We demonstrate that commercially available Cordyceps contain variable amounts of myriocin and treatment of mice with a human equivalent dose of Cordyceps extract containing myriocin, reduces ceramide accrual, increases energy expenditure, prevents diet-induced obesity, improves glucose homeostasis and resolves hepatic steatosis. Mechanistically, these beneficial effects were due to increased adipose tissue browning/beiging, improved brown adipose tissue function and hepatic insulin sensitivity as well as alterations in the abundance of gut microbes such as Clostridium and Bilophila. Collectively, our data provide proof-of-principle that myriocin containing Cordyceps extract inhibit ceramide biosynthesis and attenuate metabolic impairments associated with obesity. Moreover, these studies identify commercially available Cordyceps as a readily available supplement to treat obesity and associated metabolic diseases.

Challenges Presented by Cuffless Measurement of Blood Pressure if Adopted for Diagnosis and Treatment of Hypertension

The global health burden presented by hypertension is providing increased motivation for improved means of collection of blood pressure (BP) data. A growing area of research and commercial activity is the use of wearable devices to provide BP data using non-invasive cuffless techniques. The accelerated progress in recent years, particularly relating to connectivity of smartphone technology, has promoted the availability of consumer devices that provide values of BP. The main types of devices are wrist-worn, watch-type devices with sensors that typically record a photoplethysmography (PPG) signal, sometimes also with an electrocardiography (ECG) signal. The general underlying concept of the cuffless BP measurement in most device types is the association of BP and the travel time of the arterial pulse between two locations, determined from the time delay between the ECG and PPG signals. Other methods may involve additional analysis of the PPG waveform features. Experimental data are presented to illustrate the challenges presented by cuffless BP techniques in obtaining reliable BP measurements when the change in BP is caused by different stimuli affecting cardiac and vascular mechanisms. These effects influence the association of the measured and physiological BP change, thus presenting significant challenges and potential limitations in the use of cuffless BP devices for the diagnosis and treatment of hypertension.

Blood pressure-independent neurogenic effect on conductance and resistance vessels: a consideration for cuffless blood pressure measurement?

BACKGROUND

Pulse transit time (PTT) and pulse arrival time (PAT) are promising measures for cuffless arterial blood pressure (BP) estimation given the intrinsic arterial stiffness-BP relationship. However, arterial stiffness (and PTT) is altered by autonomically-driven smooth muscle tension changes, potentially independent of BP. This would limit PTT or PAT as accurate BP correlates, more so in resistance vessels than conductance arteries.

OBJECTIVE

To quantify if there is a measurable neurogenic effect on PAT measured using photoplethysmography (PPG) (path includes resistance vessels) and radial artery tonometry (path includes only conductance vessels) during physiologically induced BP changes.

METHODS

PATs were measured continuously in participants (n=15, 35±15 years, 9 male) using an electrocardiogram and, simultaneously, a Finometer^® PRO finger sensor, a finger PPG sensor and radial artery tonometer during seated rest, cold pressor test, cycling and isometric handgrip (IHG) exercise. ΔBP/ΔPAT was calculated for each sensor and each condition.

RESULTS

All interventions significantly increased BP. A significant difference was observed in ΔBP/ΔPAT between cycling and both the cold pressor test and IHG exercise (p<0.05). ΔBP/ΔPAT did not differ whether measured via PPG or tonometry.

CONCLUSIONS

Under the conditions tested, autonomic function does not have a BP-independent effect on PAT where the path includes resistance vessels (PPG signal), likely due to the speed of the wave and the short path length of resistance vessels. Autonomic function therefore does not limit the ability for use of PPG as a signal for potentially estimating BP without a cuff.

An investigation of the individualized, two-point calibration method for cuffless blood pressure estimation using pulse arrival time: an historical perspective using the Casio BP-100 digital watch

BACKGROUND

The use of wearable cuffless blood pressure (BP) devices is becoming commercially prevalent with little published validation information. Most devices rely, at least in part, on the relationship between pulse arrival time (PAT) and BP, a theoretical fundamental relationship that was first commercially exploited in 1993 with the release of the Casio BP-100 digital watch.

OBJECTIVE

This study explored the PAT method of BP estimation in a commercial device where it first began, the Casio BP-100 (Model No. 900) digital watch, which employs an individualized, two-point calibration method. Device accuracy was determined by comparison to a conventional cuff-based BP device measurements.

METHODS

Twenty participants (11 female, 9 male) had BP measured using both devices at rest, during a 5-minute isometric hand-grip exercise and at 1-minute post-exercise.

RESULTS

Due to bidirectional scatter of BP estimation by the BP-100 device, there was no significant difference between the reference device and the BP-100. The devices showed poor correlation for both systolic BP (SBP) (R=0.36, p=0.13) and diastolic BP (DBP) (R=0.044, p=0.37). However, on average the watch was able to provide correct directional changes in SBP but not DBP with exercise.

CONCLUSIONS

Despite being an industry first, the Casio BP-100 watch employed a method that gives a great chance of accuracy: a two point, individualized calibration method - more detailed than calibration methods in more modern devices. The watch, on average across a cohort, provided some information on BP directional change but was uncorrelated with cuff-based BP measurement. If the utility of beat-by-beat BP estimation is to be utilized, limitations of this method need to be addressed.

Human papillomavirus (HPV) vaccination across a cascade of knowledge, willingness, and uptake among gay, bisexual, and other men who have sex with men in Canada's three largest cities

BACKGROUND

Some Canadian jurisdictions offer publicly funded HPV vaccine to gay, bisexual, and other men who have sex with men (GBM) aged ≤26 years. We characterized factors associated with being in different stages of HPV vaccination.

METHODS

Engage is a sexual health study of GBM in the three largest Canadian cities recruited via respondent driven sampling (RDS). We categorized participants as: (1) unaware of HPV vaccine, (2) undecided/unwilling to get vaccinated, (3) willing to get vaccinated, (4) vaccinated with one or more doses. Our RDS-II weighted analyses used multinomial logistic regression to identify factors associated with being in earlier stages of the cascade compared to Stage 4.

RESULTS

Across the cities, 26-40%, 7-14%, 33-39%, and 13-28% were in Stages 1 to 4, respectively. Compared to Stage 4, being in earlier stages of the cascade was associated with bisexual-identification (Stage 1: adjusted odds ratio[aOR] = 2.84, 95% confidence interval[CI] = 1.06-7.62; Stage 2: aOR = 3.09, 95%CI = 1.19-8.05), having immigrated to Canada (Stage 1: aOR = 1.79, 95%CI 1.07-2.99), preference to keep same-sex romantic relationships private (Stage 1: aOR = 1.25, 95% CI = 1.05-1.48; Stage 2: aOR = 1.24, 95%CI = 1.05-1.46), not receiving sexual health information (Stage 1: aOR = 0.31, 95% CI = 0.13-0.71; Stage 2: aOR = 0.27, 95%CI = 0.12-0.64), not accessing a health-care provider (Stage 2: aOR = 0.36, 95%CI = 0.15-0.83), and no past hepatitis A/B vaccination (Stage 1: aOR = 0.16, 95% CI = 0.09-0.30; Stage 2: aOR = 0.18, 95%CI = 0.09-0.35; Stage 3: aOR = 0.38, 95%CI = 0.21-0.61).

DISCUSSION

Interventions are needed to reduce social and financial barriers, increase sexual health knowledge, and improve GBM-competent health-care access to increase vaccine uptake among GBM.

Contactless video-based photoplethysmography technique comparison investigating pulse transit time estimation of arterial blood pressure

BACKGROUND

Non-contact measurement of physiological vital signs, such as blood pressure (BP), by video-based photoplethysmography (vPPG) is a potential means for remote health monitoring. However, the signal-to-noise ratio of cardiovascular signals within the vPPG is very low.

OBJECTIVE

This study investigates the potential of BP estimation from vPPG.

METHODS

In 10 healthy volunteers (4 females, 28 ± 7 years), continuous electrocardiogram, finger BP and video of the face and palm of the hand were recorded. BP was varied by isometric hand grip exercise and leg ischemia. Four vPPG methods were compared: (i) averages of the green (GREEN) color intensity; (ii) the best linear combination of color channels using independent component analysis (ICA); (iii) a linear combination of chrominance-based (CHROM) signal by standardizing the skin color profile; (iv) plane orthogonal to the skin tone (POS) as vPPG signal. These were applied to 14 regions of interest (ROIs) on the face and 5 ROIs on the palm. Pulse transit time (PTT) between ROIs, for all permutations, were calculated and the correlation with BP quantified.

RESULTS

A significant, negative PTT-BP correlation was defined as success. A maximum success rate of 80% was achieved, occurring for the GREEN, POS and ICA methods only for specific ROIs within the face, but not for any permutation using the hand.

CONCLUSIONS

These results indicate that the use of vPPG for estimation of BP will be challenging. A combination of different vPPG methods and within-face ROIs may yield useful information.

Mitochondrial dysfunction in mouse livers depleted of iron chaperone PCBP1

Iron is an essential nutrient that forms cofactors required for the activity of hundreds of cellular proteins. However, iron can be toxic and must be precisely managed. Poly r(C) binding protein 1 (PCBP1) is an essential, multifunctional protein that binds both iron and nucleic acids, regulating the fate of both. As an iron chaperone, PCBP1 binds cytosolic iron and delivers it to iron enzymes for activation and to ferritin for storage. Mice deleted for PCBP1 in the liver exhibit dysregulated iron balance, with lower levels of liver iron stores and iron enzymes, but higher levels of chemically-reactive iron. Unchaperoned iron triggers the formation of reactive oxygen species, leading to lipid peroxidation and ferroptotic cell death. Hepatic PCBP1 deletion produces chronic liver disease in mice, with steatosis, triglyceride accumulation, and elevated plasma ALT levels. Human and mouse models of fatty liver disease are associated with mitochondrial dysfunction. Here we show that, although deletion of PCBP1 does not affect mitochondrial iron balance, it does affect mitochondrial function. PCBP1 deletion affected mitochondrial morphology and reduced levels of respiratory complexes II and IV, oxygen consumption, and ATP production. Depletion of mitochondrial lipids cardiolipin and coenzyme Q, along with reduction of mitochondrial oxygen consumption, were the first manifestations of mitochondrial dysfunction. Although dietary supplementation with vitamin E ameliorated the liver disease in mice with hepatic PCBP1 deletion, supplementation with coenzyme Q was required to fully restore mitochondrial lipids and function. In conclusion, our studies indicate that mitochondrial function can be restored in livers subjected to ongoing oxidative damage from unchaperoned iron by supplementation with coenzyme Q, a mitochondrial lipid essential for respiration that also functions as a lipophilic radical-trapping agent.

Human papillomavirus (HPV) vaccine uptake among a community-recruited sample of gay, bisexual, and other men who have sex with men in the three largest cities in Canada from 2017 to 2019

INTRODUCTION

In 2015/2016, Canada's largest provinces implemented publicly-funded human papillomavirus (HPV) vaccination programs for gay, bisexual, and other men who have sex with men (GBM) ≤ 26 years old. We sought to describe HPV vaccine uptake among GBM and determine barriers and facilitators to vaccine initiation with a focus on healthcare access and utilization.

METHODS

Engage is a cohort study among GBM aged 16 + years in three Canadian cities recruited from 2017 to 2019 via respondent driven sampling (RDS). Men completed a comprehensive questionnaire at baseline. By publicly-funded vaccine eligibility (≤26 years old = eligible for vaccination, ≥27 years old = ineligible), we described HPV vaccine uptake (initiation = 1 + dose, completion = 3 doses) and explored factors associated with vaccine initiation using Poisson regression. All analyses were weighted with the RDS-II Volz-Heckathorn estimator.

RESULTS

Across the three cities, 26-35% and 14-21% of men ≤ 26 years and 7-26% and 2-9% of men ≥ 27 years initiated and completed HPV vaccination, respectively. Vaccine initiation was significantly associated with STI/HIV testing or visiting a HIV care specialist in the past six months (≤26: prevalence ratio[PR] = 2.15, 95% confidence interval[CI] 1.06-4.36; ≥27: PR = 2.73, 95%CI 1.14-6.51) and past hepatitis A or B vaccination (≤26: PR = 2.88, 95%CI 1.64-5.05; ≥27: PR = 2.03, 95%CI 1.07-3.86). Among men ≥ 27 years old, vaccine initiation was also positively associated with accessing PrEP, living in Vancouver or Toronto, but negatively associated with identifying as Latin American and increasing age. Vaccine initiation was twice as likely among men ≥ 27 years with private insurance versus no insurance.

CONCLUSIONS

Sixty-five to 74% of men eligible for publicly-funded vaccine across the three cities remained unvaccinated against HPV by 2019. High vaccine cost may partly explain even lower uptake among men ≥ 27 years old. Men seeking sexual health care were more likely to initiate vaccination; bundling vaccination with these services may help improve HPV vaccine uptake.

Optimizing mechanical circulatory support hemodynamics using coronary sinus pacing

The role of atrioventricular (AV) dyssynchrony as a cause of low Impella device output in cardiogenic shock from acute anterior myocardial infarction (MI) responding to reestablishing AV synchrony has not been previously reported. We present, for the first time, a unique case of AV dyssynchrony causing recurrent hypotension and ventricular fibrillation in such a patient, followed by immediate return to hemodynamic stability after restoring AV synchrony. Our case also highlights the novel use of a Damato multi-polar catheter for coronary sinus pacing to achieve AV synchrony.

A novel approach for evaluating contact patterns and risk mitigation strategies for COVID-19 in English primary schools with application of structured expert judgement

Personal contacts drive COVID-19 infections. After being closed (23 March 2020) UK primary schools partially re-opened on 1 June 2020 with social distancing and new risk mitigation strategies. We conducted a structured expert elicitation of teachers to quantify primary school contact patterns and how contact rates changed upon re-opening with risk mitigation measures in place. These rates, with uncertainties, were determined using a performance-based algorithm. We report mean number of contacts per day for four cohorts within schools, with associated 90% confidence ranges. Prior to lockdown, younger children (Reception and Year 1) made 15 contacts per day [range 8.35] within school, older children (Year 6) 18 contacts [range 5.55], teaching staff 25 contacts [range 4.55] and non-classroom staff 11 contacts [range 2.27]. After re-opening, the mean number of contacts was reduced by 53% for young children, 62% for older children, 60% for classroom staff and 64% for other staff. Contacts between teaching and non-teaching staff reduced by 80%. The distributions of contacts per person are asymmetric with heavy tail reflecting a few individuals with high contact numbers. Questions on risk mitigation and supplementary structured interviews elucidated how new measures reduced daily contacts in-school and contribute to infection risk reduction.

Ceramides are necessary and sufficient for diet-induced impairment of thermogenic adipocytes

Objective

Aging and weight gain lead to a decline in brown and beige adipocyte functionality that exacerbates obesity and insulin resistance. We sought to determine whether sphingolipids, such as ceramides, a class of lipid metabolites that accumulate in aging and overnutrition, are sufficient or necessary for the metabolic impairment of these thermogenic adipocytes.

Methods

We generated new mouse models allowing for the conditional ablation of genes required for ceramide synthesis (i.e., serine palmitoyltransferase subunit 2, Sptlc2) or degradation (i.e., acid ceramidase 1, Asah1) from mature, thermogenic adipocytes (i.e., from cells expressing uncoupling protein-1). Mice underwent a comprehensive suite of phenotyping protocols to assess energy expenditure and glucose and lipid homeostasis. Complementary studies were conducted in primary brown adipocytes to dissect the mechanisms controlling ceramide synthesis or action.

Results

Depletion of Sptlc2 increased energy expenditure, improved glucose homeostasis, and prevented diet-induced obesity. Conversely, depletion of Asah1 led to ceramide accumulation, diminution of energy expenditure, and exacerbation of insulin resistance and obesity. Mechanistically, ceramides slowed lipolysis, inhibited glucose uptake, and decreased mitochondrial respiration. Moreover, β-adrenergic receptor agonists, which activate thermogenesis in brown adipocytes, decreased transcription of enzymes required for ceramide synthesis.

Conclusions

These studies support our hypothesis that ceramides are necessary and sufficient for the impairment in thermogenic adipocyte function that accompanies obesity. Moreover, they suggest that implementation of therapeutic strategies to block ceramide synthesis in thermogenic adipocytes may serve as a means of improving adipose health and combating obesity and cardiometabolic disease.

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β-Adrenergic agonists lower ceramide levels in brown adipocytes by decreasing expression of Sptlc2 and CerS6.

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Selective inhibition of ceramide synthesis in UCP1⁺ cells confers resistance to obesity and increases energy expenditure.

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Selectively inducing ceramide accumulation in UCP1⁺ cells impairs thermogenesis to exacerbate obesity and insulin resistance.

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Brown adipocyte ceramides alter mitochondrial ultrastructure and activity and influences rates of fatty acid uptake.

The effect of computer decision support on optimizing appropriate dosing of novel oral anticoagulant therapy in the IMPACT-AF study

Background

Guidelines favour use of the non-vitamin K oral anticoagulants (NOACs) over vitamin-K antagonists for stroke prevention in atrial fibrillation (AF). However, studies have shown these agents are being under-dosed relative to the doses recommended in the product labels.

Purpose

To assess the ability of a CDS tool, employed to support management of patients with AF in primary care, to optimize NOAC prescribing.

Methods

The Integrated Management Program Advancing Community Treatment of Atrial Fibrillation (IMPACT-AF) study was a cluster randomized controlled trial that assessed the ability of a CDS tool to optimize care of community-based AF patients. Between September 2014 and December 2016, 203 primary care providers (104 randomized to CDS use, 99 to usual care [UC]) and 1133 of their patients (n=597 CDS, n=548 UC) were enrolled. Among other functions, 9 CDS program rules provided recommendations on NOAC prescribing based upon a given patient's clinical profile, as per product labels. Appropriate NOAC prescribing within the IMPACT-AF study population was compared between patients managed with the CDS versus UC at baseline and 12-months.

Results

Of those patients prescribed a NOAC, a high proportion (approximately 70%) were managed as per NOAC prescribing recommendations at baseline (Fig. 1). At 12 months, this proportion did not appreciably change in the UC arm (Fig. 1). In the CDS arm, an 8.2% absolute/11.8% relative improvement in appropriate NOAC prescribing over baseline was seen at 12-months (Fig. 1).

A comparison of patients at baseline and 12-months within each arm revealed a non-significant decline in the level of appropriate NOAC prescribing in the UC group (p=0.53). In the CDS arm, a significant improvement was observed in appropriate NOAC prescribing over time (p&lt;0.001).

Conclusion

Even prior to any quality improvement efforts, appropriate NOAC prescribing was higher than anticipated in this contemporary cohort of community-based AF patients. At 12-months, significant further improvements were seen in the CDS but not the UC arm. These findings suggest that physician decision support can help enhance appropriate NOAC prescribing in the primary care setting.

Figure 1. Appropriate NOAC prescribing

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Bayer Inc.

Mitochondrial pyruvate carrier is required for optimal brown fat thermogenesis

Brown adipose tissue (BAT) is composed of thermogenic cells that convert chemical energy into heat to maintain a constant body temperature and counteract metabolic disease. The metabolic adaptations required for thermogenesis are not fully understood. Here, we explore how steady state levels of metabolic intermediates are altered in brown adipose tissue in response to cold exposure. Transcriptome and metabolome analysis revealed changes in pathways involved in amino acid, glucose, and TCA cycle metabolism. Using isotopic labeling experiments, we found that activated brown adipocytes increased labeling of pyruvate and TCA cycle intermediates from U¹³C-glucose. Although glucose oxidation has been implicated as being essential for thermogenesis, its requirement for efficient thermogenesis has not been directly tested. We show that mitochondrial pyruvate uptake is essential for optimal thermogenesis, as conditional deletion of Mpc1 in brown adipocytes leads to impaired cold adaptation. Isotopic labeling experiments using U¹³C-glucose showed that loss of MPC1 led to impaired labeling of TCA cycle intermediates. Loss of MPC1 in BAT increased 3-hydroxybutyrate levels in blood and BAT in response to the cold, suggesting that ketogenesis provides an alternative fuel source to compensate. Collectively, these studies highlight that complete glucose oxidation is essential for optimal brown fat thermogenesis.

The effects of waste sorting in environmental microbiome, THP-1 cell viability and inflammatory responses

Workers in the waste sorting industry are exposed to diverse bioaerosols. Characterization of these bioaerosols is necessary to more accurately assess the health risks of exposure. The use of high-throughput DNA sequencing for improved analysis of microbial composition of bioaerosols, in combination with their in vitro study in relevant cell cultures, represents an important opportunity to find answers on the biological effects of bioaerosols. This study aimed to characterize by high-throughput sequencing the biodiversity present in complex aerosol mixtures retained in forklift air conditioning filters of a waste-sorting industry and its effects on cytotoxicity and secretion of proinflammatory cytokines in vitro using human macrophages derived from monocytic THP-1 cells. Seventeen filters from the filtration system from forklifts operating in one waste sorting facility and one control filter (similar filter without prior use) were analyzed using high-throughput sequencing and toxicological tests in vitro. A trend of positive correlation was seen between the number of bacterial and fungal OTUs (r = 0.47, p = 0.06). Seven filters (39%) exhibited low or moderate cytotoxicity (p < 0.05). The highest cytotoxic responses had a reduction in cell viability between 17 and 22%. Filter samples evoked proinflammatory responses, especially the production of TNFα. No significant correlation was found between fungal richness and inflammatory responses in vitro. The data obtained stress the need of thorough exposure assessment in waste-sorting industry and to take immunomodulatory properties into consideration for bioaerosols hazard characterization. The broad spectrum of microbial contamination detected in this study demonstrates that adequate monitoring of bioaerosol exposure is necessary to evaluate and minimize risks. The combined techniques can support the implementation of effective environmental monitoring programs of public and occupational health importance.

Care for adult non-ICU Covid-19 patients: early experiences from a Belgian tertiary care centre

The current Covid-19 outbreak poses many challenges on hospital organisation and patient care. Our hospital lies at the epicentre of the Belgian epidemic. On April 1st, a total of 235 Covid-19 patients had been admitted to our hospital. This demanded an unprecedented adaptation of our hospital organisation, and we have met many clinical issues in the care for Covid-19 patients. In this article, we share our experience in the handling of some of the practical and organisational issues in the care for Covid-19 patients.

Effects of controlled cortical impact and docosahexaenoic acid on rat pup fatty acid profiles

Traumatic brain injury (TBI) is the leading cause of acquired neurologic disability in children, particularly in those under four years old. During this period, rapid brain growth demands higher Docosahexaenoic Acid (DHA) intake. DHA is an essential fatty acid and brain cell component derived almost entirely from the diet. DHA improved neurologic outcomes and decreased inflammation after controlled cortical impact (CCI) in 17-day old (P17) rats, our established model of pediatric TBI. In adult rodents, TBI decreases brain DHA. We hypothesized that CCI would decrease rat brain DHA at post injury day (PID) 60, blunted by 0.1% DHA diet. We quantitated fatty acids using Gas Chromatography-Mass Spectrometry. We provided 0.1% DHA before CCI to ensure high DHA in dam milk. We compared brain DHA in rats after 60 days of regular (REG) or DHA diet to SHAM pups on REG diet. Brain DHA decreased in REGCCI, not in DHACCI, relative to SHAMREG. In a subsequent experiment, we gave rat pups DHA or vehicle intraperitoneally after CCI followed by DHA or REG diet for 60 days. REG increased brain Docosapentaenoic Acid (n-6 DPA, a brain DHA deficiency marker) relative to SHAMDHA and DHACCI pups (p < 0.001, diet effect). DHA diet nearly doubled DHA and decreased n-6 DPA in blood but did not increase brain DHA content (p < 0.0001, diet effect). We concluded that CCI or craniotomy alone induces a mild DHA deficit as shown by increased brain DPA.

Epicardial Left Atrial Appendage Exclusion Reduces Blood Pressure in Patients With Atrial Fibrillation and Hypertension

BACKGROUND

Percutaneous left atrial appendage exclusion (LAAE) has evolved as an alternative strategy for stroke prevention in atrial fibrillation (AF). Recent observational data have suggested that epicardial LAAE can have substantial impact on arrhythmia burden and hemodynamic profile.

OBJECTIVES

The authors aimed to study the impact of epicardial versus endocardial LAAE on systemic blood pressure in hypertensive AF patients.

METHODS

This was a prospective, nonrandomized study comparing 247 patients who underwent epicardial LAAE with 124 patients with endocardial exclusion. Clinical outcomes were measured at 3 months and 1 year. Primary outcome was improvement in systolic blood pressure (SBP) between both groups compared with baseline. Secondary outcome included changes in diastolic pressures (DBP), serum electrolytes, and creatinine.

RESULTS

There was no significant difference in baseline SBP between epicardial and endocardial groups. SBP was significantly lower in the epicardial group both at 3 months (122 ± 11.8 mm Hg vs. 129.7 ± 8.2 mm Hg; p < 0.001) and 1 year (123 ± 11.6 mm Hg vs. 132.2 ± 8.8 mm Hg; p < 0.001) compared with the endocardial group. An adjusted multivariate linear mixed effects model demonstrated that epicardial LAAE significantly decreased SBP by 7.4 mm Hg at 3 months and by 8.9 mm Hg at 1 year (p < 0.0001). There was a trend toward lower DBP with epicardial LAAE at 3 months by 1.3 mm Hg (p = 0.2) and at 1 year by 1.8 mm Hg (p = 0.09). There was no significant difference in serum electrolytes and creatinine between both groups.

CONCLUSIONS

In hypertensive AF patients, epicardial LAAE significantly decreases SBP both at 3 and 12 months compared with endocardial exclusion.

The nucleolus functions as a phase-separated protein quality control compartment

The nuclear proteome is rich in stress-sensitive proteins, which suggests that effective protein quality control mechanisms are in place to ensure conformational maintenance. We investigated the role of the nucleolus in this process. In mammalian tissue culture cells under stress conditions, misfolded proteins entered the granular component (GC) phase of the nucleolus. Transient associations with nucleolar proteins such as NPM1 conferred low mobility to misfolded proteins within the liquid-like GC phase, avoiding irreversible aggregation. Refolding and extraction of proteins from the nucleolus during recovery from stress was Hsp70-dependent. The capacity of the nucleolus to store misfolded proteins was limited, and prolonged stress led to a transition of the nucleolar matrix from liquid-like to solid, with loss of reversibility and dysfunction in quality control. Thus, we suggest that the nucleolus has chaperone-like properties and can promote nuclear protein maintenance under stress.

Differential Activation of TRPA1 by Diesel Exhaust Particles: Relationships between Chemical Composition, Potency, and Lung Toxicity

Diesel exhaust particulate (DEP) causes pulmonary irritation and inflammation, which can exacerbate asthma and other diseases. These effects may arise from the activation of transient receptor potential ankyrin-1 (TRPA1). This study shows that a representative DEP can activate TRPA1-expressing pulmonary C-fibers in the mouse lung. Furthermore, DEP collected from idling vehicles at an emissions inspection station, the tailpipe of an on-road “black smoker” diesel truck, waste DEP from a diesel exhaust filter regeneration machine, and NIST SRM 2975 can activate human TRPA1 in lung epithelial cells to elicit different biological responses. The potency of the DEP, particle extracts, and selected chemical components was compared in TRPA1 over-expressing HEK-293 and human lung cells using calcium flux and other toxicologically relevant end-point assays. Emission station DEP was the most potent and filter DEP the least. Potency was related to the percentage of ethanol extractable TRPA1 agonists and was equivalent when equal amounts of extract mass was used for treatment. The DEP samples were further compared using scanning electron microscopy, energy-dispersive X-ray spectroscopy, gas chromatography–mass spectrometry, and principal component analysis as well as targeted analysis of known TRPA1 agonists. Activation of TRPA1 was attributable to both particle-associated electrophiles and non-electrophilic agonists, which affected the induction of interleukin-8 mRNA via TRPA1 in A549 and IMR-90 lung cells as well as TRPA1-mediated mucin gene induction in human lung cells and mucous cell metaplasia in mice. This work illustrates that not all DEP samples are equivalent, and studies aimed at assessing mechanisms of DEP toxicity should account for multiple variables, including the expression of receptor targets such as TRPA1 and particle chemistry.

Abstract P2-09-08: Imprime PGG, a novel innate immune modulator, combined with pembrolizumab in a phase 2 multicenter, open label study in chemotherapy-resistant metastatic triple negative breast cancer (TNBC)

Background: CPI monotherapy provides substantial clinical benefit to patients (pts) in multiple cancers, yet response rates are limited (˜15-30%) and fails to benefit the majority. In these pts there is limited or no ongoing T cell-based immune response. Imprime PGG (Imprime), a novel beta glucan derived from Saccharomyces, may expand the clinical benefit of CPI therapy by stimulating an anti-cancer immune response. Acting as a pathogen-associated molecularpattern (PAMP), Imprime enlists innate immune functions including cytotoxic effector mechanisms, reversal of immunosuppression and cross-talk with the adaptive immune system.Imprime-mediated innate immune activation requires formation of an immune complex with naturally-occurring anti-beta glucan antibodies (ABA); sufficient ABA levels is required for complex formation. Imprime is now being studied in combination with pembrolizumab (KEYTRUDA®,Pembro), a humanized mAb against PD-1 which has been previously studied in TNBC pts.

Methods: In this study of patients who previously failed chemotherapy for metastatic TNBC, Imprime is being used in combination with Pembro in a Simon 2 stage design. Asample size of 12 evaluable pts in Stage 1 was planned.Evaluable pts received at least one dose of study treatment (tx), had measurable disease at baseline per RECIST v1.1, had at least one post-baseline scan or discontinued tx as a result of progressive disease, death, or a tx-related adverse event before the first post-baseline scan.Pts received Imprime (4 mg/kg IV days 1, 8, 15 of each 3-week cycle) + Pembro 200 mg on D1 of each cycle. Criteria to advance to Stage 2 were ≤4 grade 3/4 AEs during the first tx cycle (other than infusion reactions) and ≥1 objective response. Study primary endpoints are ORR and safety; secondary endpoints are TTR, CRR, DoR, PFS, and OS. Exploratory endpoints include ORR and PFS per irRECIST. Biopsies and blood samples are being collected to assess tx impact on immune activating events at the tumor site and in the periphery.

Results: A review of efficacy and safety data was conducted at the end of Stage 1. Thirteen pts (12 evaluable) were enrolled into Stage 1. Safety review noted 2 grade 3 adverse events that met protocol definition of Stage 1 events (1 pt: cellulitis and 1 pt: pleural infusion; both unrelated to treatment). Two events lead to 2 pts discontinuing treatment (infusion reaction and pancreatitis) and only 1 autoimmune event was observed (pancreatitis). Observed efficacy responses in the evaluable pts included 1 complete response (CR; ongoing) and 2 partial responses (PR; ongoing). Secondary efficacy endpoints have not been assessed. Early translational results support proposed MOA and analysis of Stage 1 translational data is ongoing.

Conclusion: The use of Imprime with Pembro was well tolerated and met both safety and efficacy requirements to move forward with Stage 2 of the study. No significant safety concerns were identified in Stage 1. Further investigation is thus warranted and enrollment into Stage 2 is ongoing. Updated data will be presented.

Citation Format: O'Day S, Borges V, Chmielowski B, Rao R, Abu-Khalaf M, Stopeck A, Lowe J, Mattson P, Breuer K, Gargano M, Bose N, Uhlik M, Graff J, Chisamore M, Cox J, Osterwalder B. Imprime PGG, a novel innate immune modulator, combined with pembrolizumab in a phase 2 multicenter, open label study in chemotherapy-resistant metastatic triple negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-09-08.

Prevalence and predictors of airflow obstruction in an HIV tertiary care clinic in Montreal, Canada: a cross-sectional study

Objectives

The reported prevalence of chronic obstructive pulmonary disease (COPD) in people living with HIV (PLWHIV) varies widely. Our objective was to estimate the prevalence of airflow obstruction and COPD in unselected PLWHIV and identify characteristics that increase the risk of nonreversible airflow obstruction in order to guide case finding strategies for COPD.

Methods

All adults attending the Chronic Viral Illness Service were invited to participate in the study, regardless of smoking status or history of known COPD/asthma. Individuals underwent spirometric testing both before and after use of a salbutamol bronchodilator. Airflow obstruction was defined as forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) < 0.7 post‐bronchodilation, whereas COPD was defined as FEV₁/FVC < 0.7 post‐bronchodilation and Medical Research Council (MRC) score > 2. Multivariate logistic regression was used to evaluate risk factors associated with airflow obstruction, reported as adjusted odds ratios (aORs).

Results

Five hundred and three participants successfully completed spirometry testing. The median (Q1; Q3) age was 52 (44; 58) years. The median (Q1; Q3) CD4 count was 598 (438; 784) cells/μL and the median (Q1; Q3) nadir CD4 count was 224 (121; 351) cells/μL. There were 119 (24%) current smokers and 145 (29%) former smokers. Among those screened, 54 (11%) had airflow obstruction whereas three (1%) of the participants had COPD. Factors that were associated with airflow obstruction included a history of smoking [aOR 2.2; 95% confidence interval (CI) 1.1; 4.7], older age (aOR 1.6; 95% CI 1.2; 2.2), and lower CD4 count (aOR 0.8; 95% CI 0.7; 1.0).

Conclusions

Airflow obstruction was relatively uncommon. Our findings suggest that PLWHIV who are ≥50 years old, smokers and those with nadir CD4 counts ≤ 200 cells/μL could be targeted to undergo spirometry to diagnose chronic airflow obstruction.