Treatment with the vascular endothelial growth factor-A antibody, bevacizumab, has sex-specific effects in a rat model of mild traumatic brain injury

Mild traumatic brain injury (mTBI) involves damage to the cerebrovascular system. Vascular endothelial growth factor-A (VEGF-A) is an important modulator of vascular health and VEGF-A promotes the brain's ability to recover after more severe forms of brain injury; however, the role of VEGF-A in mTBI remains poorly understood. Bevacizumab (BEV) is a monoclonal antibody that binds to VEGF-A and neutralises its actions. To better understand the role of VEGF-A in mTBI recovery, this study examined how BEV treatment affected outcomes in rats given a mTBI. Adult Sprague-Dawley rats were assigned to sham-injury + vehicle treatment (VEH), sham-injury + BEV treatment, mTBI + VEH treatment, mTBI + BEV treatment groups. Treatment was administered intracerebroventricularly via a cannula beginning at the time of injury and continuing until the end of the study. Rats underwent behavioral testing after injury and were euthanized on day 11. In both females and males, BEV had a negative impact on cognitive function. mTBI and BEV treatment increased the expression of inflammatory markers in females. In males, BEV treatment altered markers related to hypoxia and vascular health. These novel findings of sex-specific responses to BEV and mTBI provide important insights into the role of VEGF-A in mTBI.

A pre-existing Toxoplasma gondii infection exacerbates the pathophysiological response and extent of brain damage after traumatic brain injury in mice

Traumatic brain injury (TBI) is a key contributor to global morbidity that lacks effective treatments. Microbial infections are common in TBI patients, and their presence could modify the physiological response to TBI. It is estimated that one-third of the human population is incurably infected with the feline-borne parasite, Toxoplasma gondii, which can invade the central nervous system and result in chronic low-grade neuroinflammation, oxidative stress, and excitotoxicity-all of which are also important pathophysiological processes in TBI. Considering the large number of TBI patients that have a pre-existing T. gondii infection prior to injury, and the potential mechanistic synergies between the conditions, this study investigated how a pre-existing T. gondii infection modified TBI outcomes across acute, sub-acute and chronic recovery in male and female mice. Gene expression analysis of brain tissue found that neuroinflammation and immune cell markers were amplified in the combined T. gondii + TBI setting in both males and females as early as 2-h post-injury. Glutamatergic, neurotoxic, and oxidative stress markers were altered in a sex-specific manner in T. gondii + TBI mice. Structural MRI found that male, but not female, T. gondii + TBI mice had a significantly larger lesion size compared to their uninfected counterparts at 18-weeks post-injury. Similarly, diffusion MRI revealed that T. gondii + TBI mice had exacerbated white matter tract abnormalities, particularly in male mice. These novel findings indicate that a pre-existing T. gondii infection affects the pathophysiological aftermath of TBI in a sex-dependent manner, and may be an important modifier to consider in the care and prognostication of TBI patients.

Financial Improvements from Short Course Adjuvant Vaginal Cuff Brachytherapy (VCB) in Early Endometrial Cancer Compared to Standard of Care, "SAVE" Trial

PURPOSE/OBJECTIVE(S)

Early-stage endometrial cancer is often managed with hysterectomy followed by adjuvant VCB. Financial toxicity from cancer treatment is a strong driver of adherence. The SAVE trial is a multicenter, prospective randomized trial of standard of care (SoC) VCB doses delivered in 3-5 fractions per physician discretion compared to a 2-fraction course. We report on secondary cost endpoints, quantifying the financial impacts of shorter treatment courses on institutions and participating patients.

MATERIALS/METHODS

Technical (TechCs), professional (PCs), and total charges (TotCs) were collected prospectively and are reported as raw and Medicare-adjusted charges per patient. Geographic variations were standardized with CMS Geographic Practice Cost Indices (GPCI), and inflation was adjusted using the Consumer Price Index (CPI): Medical Care. Distance to treatment center was calculated from the patient's zip code to the corresponding treatment center. Cost of commutes was estimated through round-trip travel distance multiplied by average gas MPG for new vehicles by treatment year and state. Median income for each patient's zip code was estimated using 5-year Household income in 2021 inflation-adjusted dollars from the US Census. Mann-Whitney U, T- and Chi-square tests were used to compare characteristics between the two groups.

RESULTS

One hundred eight patients were analyzed. SoC VCB was delivered in 3, 4 and 5 fractions for 27/54 (50%), 11/54 (20%), and 16/54 (30%), respectively. Median total distance traveled per patient for SoC vs. experimental arms was 213 vs 137 miles (p = .12), and median cost of commute for patients was 36.3 vs 18.0 USD (p = .11). Compared to 2-fraction treatment, 5-fraction treatment resulted in longer travel distances (median 462 vs. 137 miles, p < 0.01) and increased travel costs (median 59.3 v. 18.0 USD, p = < 0.01). Median income by zip code for SoC v. experimental arms was 79,704 vs. 79,671 USD (p = 1.0). For SoC v. experimental arms, 11 (20%) vs 7 (13%) of patients had zip codes with median income in the lowest or second lowest quintiles (p = 0.5). Adjusted raw PCs per patient did not differ between SoC vs. experimental arms (9,159$ vs. 7,532$, p = 0.19). TechCs were significantly higher on the SoC arm (35,734$ vs. 24,696$ p = < 0.01), as were TotCs (44,892$ vs. 32,228$, p < 0.01;). Medicare-adjusted PCs, TechCs, and TotCs were higher for the SoC arm (Table 1).

CONCLUSION

Two-fraction VCB resulted in fewer treatments per patient, reduced cost of travel compared to longer courses, and an adjusted reduction in healthcare expenditures compared to standard of care. Ongoing work will include assessment of patient-reported financial toxicities.

The Endoscopic Ultrasound Molecular Analysis of Pancreatic Cancer (EUMEPC) study

751

Background: Pancreatic cancer carries a dismal prognosis and limited treatment options. Attempts to implement precision therapies have proved difficult to date, in part due to challenges obtaining high quality genetic material from pancreatic biopsies. Endoscopic ultrasound (EUS) is a common diagnostic procedure, but limited data is available on the clinical utility of these biopsies for comprehensive molecular profiling (CMP) to inform therapeutic choices. Methods: This study aimed to enrol up to 150 patients undergoing EUS biopsies for pancreatic cancer, in order to complete targeted DNA/RNA sequencing on 100. The primary outcome was to characterise the proportion of patients able to undergo CMP on their diagnostic EUS biopsies, with fresh-frozen biopsies preferred but FFPE specimens accepted if there was no alternative. Secondary endpoints included the proportion of patients with clinically relevant molecular findings as determined by Molecular Tumour Board (MTB) discussion, proportion of patients initiating targeted therapies, and quantitative/qualitative analysis on molecular material derived from fresh-frozen versus FFPE EUS biopsies. Results: 109 patients have been enrolled since May 2020, and molecular profiling has been completed for 102 patients. 2 patients (1.8%) were excluded due to having no available biopsies, and 5 biopsies (4.7%) were unable to be sequenced due to inadequate quality metrics. Common oncogenes were detected at roughly expected frequencies, with mutations in KRAS occurring in 91 (89.2%), TP53 in 67 (65.7%), SMAD4 in 11 (10.8%) and CDKN2A in 7 (6.8%). Median tumour mutation burden (TMB) in this cohort was low at 3.1Mut/Mb although 7 patients (6.9%) had a high TMB (defined as >10Mut/Mb), of which 3 (2.9%) had markedly hypermutated tumours (>200Mut/Mb). All processed samples were microsatellite stable. Therapeutically relevant mutations were detected in 21 (20.6%) including RNF43 in 7 patients (6.9%), KRAS G12C and BRCA in 3 patients each (2.9%), in addition to BRAF V600E in 2 (1.9%), and CHEK2 and BARD1 mutations in 1 each (0.9%). High TMB was observed in 7 patients (6.9%). To date, 5 patients (4.9%) have commenced on targeted therapies, with one patient notably experiencing a complete response to targeted therapy which has now been sustained for >12 months. Conclusions: This real-world study confirms the utility of endoscopic biopsies as a valuable and reliable source of genetic material for clinically relevant molecular tumour profiling. Secondary analyses are underway to further characterise treatment and survival implications in this cohort.

Pre-existing Toxoplasma gondii infection increases susceptibility to pentylenetetrazol-induced seizures independent of traumatic brain injury in mice

Introduction

Post-traumatic epilepsy (PTE) is a debilitating chronic outcome of traumatic brain injury (TBI), and neuroinflammation is implicated in increased seizure susceptibility and epileptogenesis. However, how common clinical factors, such as infection, may modify neuroinflammation and PTE development has been understudied. The neurotropic parasite, Toxoplasma gondii (T. gondii) incurably infects one-third of the world's population. Thus, many TBI patients have a pre-existing T. gondii infection at the time of injury. T. gondii infection results in chronic low-grade inflammation and altered signaling pathways within the brain, and preliminary clinical evidence suggest that it may be a risk factor for epilepsy. Despite this, no studies have considered how a pre-existing T. gondii infection may alter the development of PTE.

Methods

This study aimed to provide insight into this knowledge gap by assessing how a pre-existing T. gondii infection alters susceptibility to, and severity of, pentylenetetrazol (PTZ)-induced seizures (i.e., a surrogate marker of epileptogenesis/PTE) at a chronic stage of TBI recovery. We hypothesized that T. gondii will increase the likelihood and severity of seizures following PTZ administration, and that this would occur in the presence of intensified neuroinflammation. To test this, 6-week old male and female C57BL/6 Jax mice were intraperitoneally injected with 50,000 T. gondii tachyzoites or with the PBS vehicle only. At 12-weeks old, mice either received a severe TBI via controlled cortical impact or sham injury. At 18-weeks post-injury, mice were administered 40 mg/kg PTZ and video-recorded for evaluation of seizure susceptibility. Fresh cortical tissue was then collected for gene expression analyses.

Results

Although no synergistic effects were evident between infection and TBI, chronic T. gondii infection alone had robust effects on the PTZ-seizure response and gene expression of markers related to inflammatory, oxidative stress, and glutamatergic pathways. In addition to this, females were more susceptible to PTZ-induced seizures than males. While TBI did not impact PTZ responses, injury effects were evident at the molecular level.

Discussion

Our data suggests that a pre-existing T. gondii infection is an important modifier of seizure susceptibility independent of brain injury, and considerable attention should be directed toward delineating the mechanisms underlying this pro-epileptogenic factor.

The Clinical Significance of Maximum Tumor Diameter on MRI in Men Undergoing Radical Prostatectomy or Definitive Radiotherapy for Locoregional Prostate Cancer

INTRODUCTION

Maximum tumor diameter (MTD) on pretreatment magnetic resonance imaging (MRI) has the potential to further risk stratify for men with prostate cancer (PCa) prior to definitive local therapy. We aim to evaluate the prognostic impact of radiographic maximum tumor diameter (MTD) in men with localized prostate cancer.

PATIENTS AND METHODS

From a single-center retrospective cohort of men receiving definitive treatment for PCa (radical prostatectomy [RP] or radiotherapy [RT]) with available pretreatment MRI, we conducted univariable and multivariable Cox proportional-hazards models for progression using clinical variables including age, NCCN risk group, radiographic extracapsular extension (ECE), radiographic seminal vesical invasion (SVI), and MTD. RP and RT cohorts were analyzed separately. Covariates were used in a classification and regression tree (CART) analysis and progression-free survival was estimated with the Kaplan-Meier method and groups were compared using log-rank tests.

RESULTS

The cohort included 631 patients (n = 428 RP, n = 203 RT). CART analysis identified 4 prognostic groups for patients treated with RP and 2 prognostic groups in those treated with RT. In the RP cohort, NCCN low/intermediate risk group patients with MTD>=15 mm had significantly worse PFS than those with MTD <= 14 mm, and NCCN high-risk patients with radiographic ECE had significantly worse PFS than those without ECE. In the RT cohort, PFS was significantly worse in the cohort with MTD >= 23 mm than those <= 22 mm.

CONCLUSION

Radiographic MTD may be a useful prognostic factor for patients with locoregional prostate cancer. This is the first study to illustrate that the importance of pretreatment tumor size may vary based on treatment modality.

Treatment with vascular endothelial growth factor-A worsens cognitive recovery in a rat model of mild traumatic brain injury

Mild traumatic brain injury (mTBI) is a common and unmet clinical issue, with limited treatments available to improve recovery. The cerebrovascular system is vital to provide oxygen and nutrition to the brain, and a growing body of research indicates that cerebrovascular injury contributes to mTBI symptomatology. Vascular endothelial growth factor-A (VEGF-A) is a potent promoter of angiogenesis and an important modulator of vascular health. While indirect evidence suggests that increased bioavailability of VEGF-A may be beneficial after mTBI, the direct therapeutic effects of VEGF-A in this context remains unknown. This study therefore aimed to determine whether intracerebroventricular administration of recombinant VEGF-A could improve recovery from mTBI in a rat model. Male and female Sprague-Dawley rats were assigned to four groups: sham + vehicle (VEH), sham + VEGF-A, mTBI + VEH, mTBI + VEGF-A. The mTBI was induced using the lateral impact model, and treatment began at the time of the injury and continued until the end of the study. Rats underwent behavioral testing between days 1 and 10 post-injury, and were euthanized on day 11 for post-mortem analysis. In males, the mTBI + VEGF-A group had significantly worse cognitive recovery in the water maze than all other groups. In females, the VEGF treatment worsened cognitive performance in the water maze regardless of mTBI or sham injury. Analysis of hippocampal tissue found that these cognitive deficits occurred in the presence of gene expression changes related to neuroinflammation and hypoxia in both male and female rats. These findings indicate that the VEGF-A treatment paradigm tested in this study failed to improve mTBI outcomes in either male or female rats.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Optimal strategies to screen health care workers for COVID-19 in the US: a cost-effectiveness analysis

Background

Transmission of SARS-CoV-2 in health care facilities poses a challenge against pandemic control. Health care workers (HCWs) have frequent and high-risk interactions with COVID-19 patients. We undertook a cost-effectiveness analysis to determine optimal testing strategies for screening HCWs to inform strategic decision-making in health care settings.

Methods

We modeled the number of new infections, quality-adjusted life years lost, and net costs related to six testing strategies including no test. We applied our model to four strata of HCWs, defined by the presence and timing of symptoms. We conducted sensitivity analyses to account for uncertainty in inputs.

Results

When screening recently symptomatic HCWs, conducting only a PCR test is preferable; it saves costs and improves health outcomes in the first week post-symptom onset, and costs $83,000 per quality-adjusted life year gained in the second week post-symptom onset. When screening HCWs in the late clinical disease stage, none of the testing approaches is cost-effective and thus no testing is preferable, yielding $11 and 0.003 new infections per 10 HCWs. For screening asymptomatic HCWs, antigen testing is preferable to PCR testing due to its lower cost.

Conclusions

Both PCR and antigen testing are beneficial strategies to identify infected HCWs and reduce transmission of SARS-CoV-2 in health care settings. IgG tests’ value depends on test timing and immunity characteristics, however it is not cost-effective in a low prevalence setting. As the context of the pandemic evolves, our study provides insight to health-care decision makers to keep the health care workforce safe and transmissions low.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12962-021-00336-x.

Timing and Motivations for Alternative Cancer Therapy: Insights from a Crowdfunding Platform (Preprint)

Background

Alternative cancer therapy is associated with increased mortality, but little is known about those who pursue it.

Objective

We aimed to describe individuals’ motivations for using alternative cancer therapies and determine whether motivations differ based on individuals’ timing of seeking alternative therapies.

Methods

We used data from 649 campaigns posted on the website GoFundMe between 2011 and 2019 for beneficiaries with cancer pursuing alternative therapy. The data were analyzed using a mixed methods approach. Campaigns were categorized by timing of alternative therapy (either before or after experiencing conventional therapy). Qualitative analysis identified motivational themes. Chi-square tests of independence and Fisher tests (all 2-sided) determined significant differences in the presence of motivational themes between groups.

Results

The expression of concerns about the efficacy of conventional therapy was significantly more likely in campaigns for individuals who used conventional therapy first than in campaigns for individuals who started with alternative therapy (63.3% vs 41.7%; P<.001). Moreover, on comparing those who started with alternative therapy and those who switched from conventional to alternative therapy, those who started with alternative therapy more often expressed natural and holistic values (49.3% vs 27.0%; P<.001), expressed an unorthodox understanding of cancer (25.5% vs 16.4%; P=.004), referenced religious or spiritual beliefs (15.1% vs 8.9%; P=.01), perceived alternative treatment as efficacious (19.1% vs 10.2%; P=.001), and distrusted pharmaceutical companies (3.2% vs 0.5%; P=.04).

Conclusions

Individuals sought treatments that reflected their values and beliefs, even if scientifically unfounded. Many individuals who reported prior conventional cancer therapy were motivated to pursue alternative treatments because they perceived the conventional treatments to be ineffective.

Optimal strategies to screen health care workers for COVID-19 in the US: a cost-effectiveness analysis

BACKGROUND

Transmission of SARS-CoV-2 in health care facilities poses a challenge against pandemic control. Health care workers (HCWs) have frequent and high-risk interactions with COVID-19 patients. We undertook a cost-effectiveness analysis to determine optimal testing strategies for screening HCWs to inform strategic decision-making in health care settings.

METHODS

We modeled the number of new infections, quality-adjusted life years lost, and net costs related to six testing strategies including no tests. We applied our model to four strata of HCWs, defined by the presence and timing of symptoms. We conducted sensitivity analyses to account for uncertainty in inputs.

RESULTS

When screening recently symptomatic HCWs, conducting only a PCR test is preferable; it saves costs and improves health outcomes in the first week post-symptom onset, and costs $83,000 per quality-adjusted life year gained in the second week post-symptom onset. When screening HCWs in the late clinical disease stage, none of the testing approaches is cost-effective and thus no testing is preferable, yielding $11 and 0.003 new infections per 10 HCWs. For screening asymptomatic HCWs, antigen testing is preferable to PCR testing due to its lower cost.

CONCLUSIONS

Both PCR and antigen testing are beneficial strategies to identify infected HCWs and reduce transmission of SARS-CoV-2 in health care settings. IgG testing clinical value depends on test timing and immunity characteristics, however is not cost-effective in a low prevalence setting. As the context of the pandemic evolves, our study provides insight to health-care decision makers to keep the health care workforce safe and transmissions low.

Post-operative volumes following endoscopic surgery for non-functioning pituitary macroadenomas are predictive of further intervention, but not endocrine outcomes

BACKGROUND

Transsphenoidal surgery (TSS) remains the treatment of choice for non-functioning pituitary macroadenomas (NFPMA). The value of measuring tumour volumes before and after surgery, and its influence on endocrine outcomes and further treatment of the residual or recurrent tumour are unknown.

METHODS

Data from patients who underwent endoscopic TSS for a NFPMA (2009-2018) in a UK tertiary centre were analysed for pre- and post-operative endocrine and surgical outcomes.

RESULTS

Of 173 patients with NFPMA, 159 (61% male) were treatment naïve. At presentation, 76.2% (77/101) had ≥1 pituitary axis deficit. Older age (p = 0.002) was an independent predictor for multiple hormonal deficiencies. Preoperative tumour volume did not correlate with degree of hypopituitarism. Postoperative tumour volume and extent of tumour resection were not predictive of new onset hypopituitarism. Hormonal recovery was observed in 16 patients (20.8%) with impaired pituitary function, with the greatest recovery in the hypothalamic-pituitary-adrenal axis (21.2%, 7/33). A larger residual tumour volume was predictive of adjuvant radiotherapy (3.40 vs. 1.24 cm³, p = 0.005) and likelihood for repeat surgery (5.40 vs. 1.67cm³, p = 0.004).

CONCLUSION

Pre- and post-operative NFPMA volumes fail to predict the number of pituitary hormone deficits, however, greater post-operative residual volumes increase the likelihood of further intervention to control tumour growth.

Trocar site closure with a novel anchor-based (neoClose®) system versus standard suture closure: A prospective randomized controlled trial

Objective

Patients with obesity have a higher risk of trocar site hernia. The objective of the present study was to compare a standard suture passer versus the neoClose® device for port site fascial closure in patients with obesity undergoing laparoscopic bariatric surgery.

Methods

This is a randomized, controlled trial with two parallel arms. Thirty five patients with BMI ≥ 35 kg/m2 and undergoing laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass were randomized to each group. Port site fascial closure for trocars ≥ 10 mm was performed with the neoClose® device in the study group and the standard suture passer in the control group. Primary outcomes were time required to complete closure and intensity of postoperative pain at the fascial closure sites. Secondary outcomes were intraabdominal needle depth and incidence of trocar site hernia.

Results

The use of the neoClose® device resulted in shorter closure times (20.2 vs 30.0 s, p = 0.0002), less pain (0.3 vs 0.9, p = 0.002) at port closure sites, and decreased needle depth (3.3 cm vs 5.2 cm, p &lt; 0.0001) compared to the standard suture passer. There was no trocar site hernia at the one-year follow-up in either group.

Conclusion

Use of the neoClose® device resulted in faster fascial closure times, decreased intraoperative needle depth, and decreased postoperative abdominal pain at 1 week as compared to the standard suture passer. These data need to be confirmed on larger cohorts of patients with longer follow-up, especially in terms of long-term hernia recurrence rates.

Conserving the genetic diversity of condemned populations: Optimizing collections and translocation

We consider approaches for conserving genetic diversity from plant populations whose destruction is imminent. We do this using SNP genotype data from two endangered species, Pimelea spicata and Eucalyptus sp. Cattai. For both species, we genotyped plants from a 'condemned' population and designed ex situ collections, characterizing how the size and composition of the collection affected the genetic diversity preserved. Consistent with previous observations, populations where genetic diversity was optimized captured more alleles than populations of equal size chosen at random. This benefit of optimization was larger when the propagation population was small. That is, small numbers of individuals (e.g. 20) needed to be selected carefully to capture a comparable proportion of alleles to optimized populations, but larger random populations (e.g. >48) captured almost as many alleles as optimized populations. We then examined strategies for generating translocation populations based on the horticultural constraints presented by each species. In P. spicata, which is readily grown from cuttings, we designed translocation populations of different sizes, using different numbers of ramets from each member of propagation populations. We then performed simulations to predict the loss of alleles from these populations over 10 generations. Large translocation populations were predicted to maintain a greater proportion of source population alleles than smaller translocation populations, but this effect was saturated beyond 200 individuals. In E. sp. Cattai, we examined strategies to promote the diversity of progeny from a conservation planting scenario with 36 individuals. This included the optimization of the spatial arrangement of the planting and supplementing the diversity of the condemned population with individuals from additional sites. In sum, we studied approaches for designing genetically diverse translocations of condemned populations for two species that require contrasting methods of propagation, illustrating the application of approaches that were useful in different circumstances.

Treatment Preferences for Cardiac Procedures of Patients With Chronic Kidney Disease in Acute Coronary Syndrome: Design and Pilot Testing of a Discrete Choice Experiment

Background:

Chronic kidney disease is associated with a high incidence of acute coronary syndrome and related morbidity and mortality. Treatment choices for patients with chronic kidney disease involve trade-offs in the potential benefits and harms of invasive management options.

Objective:

The objective was to quantify preferences of patients with chronic kidney disease toward invasive heart procedures.

Design:

Design and pilot a discrete choice experiment.

Setting:

We piloted the discrete choice experiment in 2 multidisciplinary chronic kidney disease clinics in Calgary, Alberta, using an 8-question survey.

Patients:

Eligible patients included those aged 18 years and older, an estimated glomerular filtration rate < 45 mL/min/1.73 m², not currently receiving dialysis, and able to communicate in English.

Measurements:

Quantification of the average importances of key attributes of invasive heart procedures.

Methods:

We identified attributes most important to patients and physicians concerning invasive versus conservative management for acute coronary syndrome, using semi-structured qualitative interviews. Levels for each attribute were derived from analysis of early invasive versus conservative acute coronary syndrome management clinical trials and cohort studies, where subgroups of patients with chronic kidney disease were reported. We designed the pilot study with patient partners with relevant lived experience and considered statistical efficiency to estimate main effects and interactions, as well as response efficiency. Hierarchical Bayesian estimation was used to quantify average importances of attributes.

Results:

We recruited 43 patients with chronic kidney disease, mean (SD) age 67 (14) years, 67% male, and 35% with a history of cardiovascular disease, of whom 39 completed the survey within 2 weeks of enrollment. The results of the pilot revealed acute kidney injury requiring dialysis and permanent kidney replacement therapy, as well as death within 1 year were the most important attributes. Measures of internal validity for the pilot discrete choice experiment were comparable to those for other published discrete choice experiments.

Limitations:

Discrete choice experiments are complex instruments and often cognitively demanding for patients. This survey included multiple risk attributes which may have been challenging for some patients to understand.

Conclusions:

This pilot study demonstrates the feasibility of a discrete choice experiment to quantify preferences of patients with chronic kidney disease toward the benefits and trade-offs related to invasive versus conservative management for acute coronary syndrome. These preliminary findings suggest that patients with chronic kidney disease may be on average similarly risk averse toward kidney replacement therapy and death. This pilot information will be used to inform a larger discrete choice experiment that will refine these estimates of patient preferences and characterize subgroups with distinct treatment preferences, which should provide new knowledge that can facilitate shared decision-making between patients with chronic kidney disease and their care providers in the setting of acute coronary syndrome.

Urban air particulate matter induces mitochondrial dysfunction in human olfactory mucosal cells

BACKGROUND

The adverse effects of air pollutants including particulate matter (PM) on the central nervous system is increasingly reported by epidemiological, animal and post-mortem studies in the last decade. Oxidative stress and inflammation are key consequences of exposure to PM although little is known of the exact mechanism. The association of PM exposure with deteriorating brain health is speculated to be driven by PM entry via the olfactory system. How air pollutants affect this key entry site remains elusive. In this study, we investigated effects of urban size-segregated PM on a novel cellular model: primary human olfactory mucosal (hOM) cells.

RESULTS

Metabolic activity was reduced following 24-h exposure to PM without evident signs of toxicity. Results from cytometric bead array suggested a mild inflammatory response to PM exposure. We observed increased oxidative stress and caspase-3/7 activity as well as perturbed mitochondrial membrane potential in PM-exposed cells. Mitochondrial dysfunction was further verified by a decrease in mitochondria-dependent respiration. Transient suppression of the mitochondria-targeted gene, neuronal pentraxin 1 (NPTX1), was carried out, after being identified to be up-regulated in PM2.5-1 treated cells via RNA sequencing. Suppression of NPTX1 in cells exposed to PM did not restore mitochondrial defects resulting from PM exposure. In contrast, PM-induced adverse effects were magnified in the absence of NPTX1, indicating a critical role of this protein in protection against PM effects in hOM cells.

CONCLUSION

Key mitochondrial functions were perturbed by urban PM exposure in a physiologically relevant cellular model via a mechanism involving NPTX1. In addition, inflammatory response and early signs of apoptosis accompanied mitochondrial dysfunction during exposure to PM. Findings from this study contribute to increased understanding of harmful PM effects on human health and may provide information to support mitigation strategies targeted at air pollution.

97 Complexity In Croydon

Introduction

The Complex Care Support Team (CCST) are a newly-formed, integrated service, caring for Croydon residents when existing services decide additional multidisciplinary team input is required.

There is no single definition of healthcare complexity. Most cases encountered by the team have involved many different services and professionals. The team have found that by forging relationships and co-ordinating care across organisational boundaries, some of the “complexities” can be mitigated. We aim to develop our understanding of the needs of this population and the underlying drivers for complexity in Croydon.

Methods

The records on EMIS, CERNER and ePJS were reviewed from the inaugural two months of the service, for:Rockwood Frailty ScoreNumber of medicationsNumber of long-term conditionsED attendances or admissions to hospital over the preceding year.

After team discussion on every case, underlying causes of complexity were assigned to four groups: medical, psychological, social and systems failure.

Results

Of the 57 people accepted by CCST over 2 months, 39 required reviewing in person. 5 records were not completed, so 34 cases were included for evaluation. The age range of this cohort was 49-92, with 17 male and 17 female. Results revealed significant frailty, multimorbidity and polypharmacy. 91% had two or more underlying drivers for complexity, with the largest underlying driver being systems failure, in 85% of cases.

Conclusions

This work improves our understanding of the needs of the population deemed the most “complex” in Croydon. The likelihood of multiple underlying drivers for complexity was high, highlighting how complex health issues are likely to span both professional and organisational boundaries. This can in itself be a significant underlying driver for complexity, illustrated here as “systems failure”. In developing current and future services, this work reinforces the vital benefits of multidisciplinary and cross-organisational working currently occurring in CCST.

Genetic associations with clozapine-induced myocarditis in patients with schizophrenia

Clozapine is the most effective antipsychotic drug for schizophrenia, yet it can cause life-threatening adverse drug reactions, including myocarditis. The aim of this study was to determine whether schizophrenia patients with clozapine-induced myocarditis have a genetic predisposition compared with clozapine-tolerant controls. We measured different types of genetic variation, including genome-wide single-nucleotide polymorphisms (SNPs), coding variants that alter protein expression, and variable forms of human leucocyte antigen (HLA) genes, alongside traditional clinical risk factors in 42 cases and 67 controls. We calculated a polygenic risk score (PRS) based on variation at 96 different genetic sites, to estimate the genetic liability to clozapine-induced myocarditis. Our genome-wide association analysis identified four SNPs suggestive of increased myocarditis risk (P < 1 × 10^-6), with odds ratios ranging 5.5-13.7. The SNP with the lowest P value was rs74675399 (chr19p13.3, P = 1.21 × 10^-7; OR = 6.36), located in the GNA15 gene, previously associated with heart failure. The HLA-C*07:01 allele was identified as potentially predisposing to clozapine-induced myocarditis (OR = 2.89, 95% CI: 1.11-7.53), consistent with a previous report of association of the same allele with clozapine-induced agranulocytosis. Another seven HLA alleles, including HLA-B*07:02 (OR = 0.25, 95% CI: 0.05-1.2) were found to be putatively protective. Long-read DNA sequencing provided increased resolution of HLA typing and validated the HLA associations. The PRS explained 66% of liability (P value = 9.7 × 10^-5). Combining clinical and genetic factors together increased the proportion of variability accounted for (r² 0.73, P = 9.8 × 10^-9). However, due to the limited sample size, individual genetic associations were not statistically significant after correction for multiple testing. We report novel candidate genetic associations with clozapine-induced myocarditis, which may have potential clinical utility, but larger cohorts are required for replication.