A literature review and expert consensus statement on diagnostics in suspected metal implant allergy

BACKGROUND

Although rare, allergic reactions to metal implants represent a diagnostic challenge in view of missing guidelines.

OBJECTIVES

To develop an European expert consensus on characteristics of metal allergy reactions and the utility of various diagnostic tools in suspected metal implant allergy.

METHODS

A nominal group technique (NGT) was applied to develop consensus statements. Initially an online literature database was created on a secure server to enable a comprehensive information. Twenty-three statements were formulated on potential aspects of metal implant allergy with a focus on diagnostics and grouped into five domains. For the consensus development, the panel of 12 experts initially did refine and reformulate those statements that were ambiguous or had unclear wording. By face-to-face (9/12) or virtual participation (3/12), an anonymous online voting was performed.

RESULTS

Consensus (≥80% of agreement) was reached in 20/23 statements. The panel agreed that implant allergy despite being rare should be considered in case of persistent unexplained symptoms. It was, however, recommended to allow adequate time for resolution of symptoms associated with healing and integration of an implant. Obtaining questionnaire-aided standardized medical history and standardized scoring of patient outcomes was also considered an important step by all experts There was broad consensus regarding the utility/performance of patch testing with additional late reading. It was recognized that the lymphocyte transformation test (LTT) has to many limitations to be generally recommended. Prior to orthopaedic implant, allergy screening of patients without a history of potential allergy to implant components was not recommended.

CONCLUSIONS

Using an expert consensus process, statements concerning allergy diagnostics in suspected metal implant allergy were created. Areas of nonconsensus were identified, stressing uncertainty among the experts around topics such as preoperative testing in assumed allergy, histological correlate of periimplant allergy and in vitro testing, which underscores the need for further research.

Comparison of typical radiation doses and risks using an anthropomorphic 'bone fracture' phantom for commonly performed X-ray projections in a 5-year-old

INTRODUCTION

Diagnostic reference levels (DRLs) are typical dose levels for medical imaging examinations for groups of standard-sized patients or standard phantoms for broadly defined types of equipment used as a tool to aid optimisation of protection for medical exposures. Currently, there are no paediatric DRLs for conventional radiography (i.e. general X-rays) published in Australia. The aim of this study was to establish typical radiation doses and risks that are representative of those delivered for commonly performed X-ray projections for a 5-year-old/20 kg child using a 5-year-old anthropomorphic 'bone fracture' phantom in three dedicated paediatric radiology departments in Victoria.

METHODS

A total of 20 projection images were acquired for a standard 5-year-old/20 kg phantom using digital radiography X-ray equipment. The air kerma-area product (KAP) measured at each centre by a KAP metre, which was calibrated to a national primary standard, was considered to represent the median value for that centre for each X-ray projection. Organ doses and effective dose were estimated using PCXMC software, and risks of radiation-induced cancer and radiation-induced death were calculated based on the BEIR VII report.

RESULTS

The typical doses for the individual X-ray projections ranged from 3 mGy•cm2 to 86 mGy•cm2 , whilst the effective doses ranged from 0.00004 to 0.07 mSv. The radiation risks were 'minimal' to 'negligible'.

CONCLUSION

The estimation of typical radiation doses and associated risks for a 5-year-old/20 kg phantom study provides reference values for guidance and is a first step in assisting optimisation at other institutions until national DRLs, based on patient data from the clinical setting, are published.

Effect of Standardized Reminder Calls on Trauma Patient No-Show Rate

BACKGROUND

Most patients who sustain a traumatic injury require outpatient follow-up. A common barrier to outpatient postadmission care is patient failure to follow-up. One of the most significant factors resulting in failure to follow-up is age more than 35 years. Recent work has shown that follow-up telephone calls reduce readmission rates. Our aim was to decrease no-show appointments by 10% in 12 months.

STUDY DESIGN

The electronic medical records at our level I and II trauma centers were queried for all outpatient appointments for trauma between July 1, 2020, and June 9, 2021, and whether the patient attended their follow-up appointment. Patients with visits scheduled after August 1, 2021, received 24- and 48-hour previsit reminder calls. Patients with visits scheduled between July 1, 2020, and August 1, 2021, did not receive previsit calls. Both groups were compared using multivariable direct logistic regression models.

RESULTS

A total of 1,822 follow-up opportunities were included in the study. During the pre-implementation phase, there was a no-show rate of 30.9% (329 of 1,064 visits). Postintervention, a 12.2% reduction in overall no-show rate occurred. A statistically significant 11.2% decrease (p < 0.001) was seen in elderly patients. Multivariate analysis showed standardized calls resulted in significantly decreased odds of failing to keep an appointment (adjusted odds ratio = 0.610, p < 0.001).

CONCLUSIONS

Reminder calls led to a 12.2% reduction in no-show rate and were an independent predictor of a patient's likelihood of attending their appointment. Other predictors of attendance included insurance status and abdominal injury.

Emergency Department and Inpatient Utilization Reductions and Cost Savings Associated With Trauma Center Mental Health Intervention: Results From a 5-year Longitudinal Randomized Clinical Trial Analysis

OBJECTIVE

To identify and refer patients at high risk for the psychological sequelae of traumatic injury, the American College of Surgeons Committee on Trauma now requires that trauma centers have in-place protocols. No investigations have documented reductions in utilization and associated potential cost savings associated with trauma center mental health interventions.

BACKGROUND

The investigation was a randomized clinical trial analysis that incorporated novel 5-year emergency department (ED)/inpatient health service utilization follow-up data.

METHODS

Patients were randomized to a mental health intervention, targeting the psychological sequelae of traumatic injury (n = 85) versus enhanced usual care control (n = 86) conditions. The intervention included case management that coordinated trauma center-to-community care linkages, psychotropic medication consultation, and psychotherapy elements. Mixed model regression was used to assess intervention and control group utilization differences over time. An economic analysis was also conducted.

RESULTS

Over the course of the 5-year intervention, patients demonstrated significant reductions in ED/inpatient utilization when compared with control patients [ F (19,3210) = 2.23, P = 0.009]. Intervention utilization reductions were greatest at 3 to 6 months (intervention 15.5% vs control 26.7%, relative risk = 0.58, 95% CI: 0.34, 1.00) and 12 to 15 months (intervention 16.5% vs control 30.6%, relative risk = 0.54, 95% CI: 0.32, 0.91) postinjury time points. The economic analysis suggested potential intervention cost savings.

CONCLUSIONS

Mental health intervention is associated with significant reductions in ED and inpatient utilization, as well as potential cost savings. These findings could be productively integrated into future American College of Surgeons Committee on Trauma policy discussions.

No difference in patient reported outcome and inflammatory response after coated and uncoated total knee arthroplasty - a randomized controlled study

BACKGROUND

Allergies against implant materials are still not fully understood. Despite controversies about its relevance, some patients need treatment with hypoallergenic implants. This study compared coated and standard total knee arthroplasty (TKA) regarding inflammatory response and patient-reported outcome measures (PROMs).

METHODS

76 patients without self-reported allergies against implant materials were included in a RCT and received a coated or standard TKA of the same cemented posterior-stabilized knee system. 73 patients completed the 3-year follow-up. Two patients died and there was one revision surgery. Serum levels of cytokines with a possible role in implant allergy were measured in patient`s serum (IL-1beta, IL-5, IL-6, IL-8, IL-10, IFN γ, TNF α) prior to, one and three years after surgery. Furthermore, PROMs including knee function (Oxford Knee Score, Knee Society Score) and health-related quality of life (QoL, EuroQuol questionnaire) were assessed. Additionally, 8 patients with patch-test proven skin allergy against implant materials who received the coated implant were assessed similarly and compared to a matched-pair group receiving the same implant.

RESULTS

There were no differences in function and QoL between the assessed groups at any follow-up. The majority of patients demonstrated no elevation of the measured blood cytokines. Cytokine patterns showed no differences between study groups at any follow-up. The allergy patients demonstrated slower functional improvement and minor differences in cytokine pattern. Yet these results were not significant. There were no differences in the matched-pair analysis.

CONCLUSION

We observed no relevant increase in serum cytokine levels in any group. The inflammatory response measured seems limited, even in allergy patients. Furthermore, there were no differences between coated and standard TKA in non-allergy patients in the 3-year Follow-Up period.

TRIAL REGISTRATION

The study protocol was registered in the US National Institutes of Health's database ( http://www.

CLINICALTRIALS

gov ) registry under NCT03424174 on 03/17/2016.

Ligand-independent signaling and migration of breast cancer cells expressing membrane androgen receptor, ZIP9 (SLC39A9)

Zinc transporter ZIP9 is also a membrane androgen receptor that mediates androgen-dependent zinc and G-protein signaling to modulate tumorigenic responses in cancer cells. It is unclear whether unliganded ZIP9 causes similar responses. ZIP9 overexpression in MDA-MB-231 breast cancer cells (ZIP9 cells) increased zinc levels and cell migration/invasion which was mimicked with a zinc ionophore and attenuated with a zinc chelator, suggesting these tumorigenic responses are zinc-dependent. Expression of migration markers MYL9 and CYR61 was elevated in ZIP9 cells and further increased together with cell migration by forskolin treatment and blocked with H-89, indicating they are mediated through an AC/PKA pathway. Knockdown of ZIP9 expression in MDA-MB-468 cells decreased cell migration/invasion, migration markers and zinc levels, confirming similar roles of unliganded ZIP9 in another breast cancer cell line. Testosterone treatment further increased migration, biomarker expression and zinc in ZIP9 cells, suggesting it may act through similar pathways to induce tumorigenic responses.

Membrane progesterone receptors on the cell membrane: A review highlighting potential export motifs in mPRα regulating its trafficking to the cell surface

Substantial progress has been made in our understanding of the nongenomic actions, ligand binding, intracellular signaling pathways, and functions of membrane progesterone receptors (mPRs) in reproductive and nonreproductive tissues since their discovery 20 years ago. The five mPRs are members of the progestin adipoQ receptor (PAQR) family which also includes adiponectin receptors (AdipoRs). However, unlike AdipoRs, the 3-D structures of mPRs are unknown, and their structural characteristics remain poorly understood. The mechanisms regulating mPR functions and their trafficking to the cell surface have received little attention and have not been systematically reviewed. This paper summarizes some structural aspects of mPRs, including the ligand binding pocket of mPRα recently derived from homology modeling with AdipoRs, and the proposed topology of mPRs from the preponderance of positively charged amino acid residues in their intracellular domains. The mechanisms of trafficking membrane receptors to the cell surface are discussed, including the amino acid motifs involved with their export to the cell surface, the roles of adaptor proteins, and post-translational glycosylation and palmitoylation modifications that promote cell surface expression and retention. Evidence for similar mechanisms regulating the expression and functions of mPRs on the cell surface is discussed, including the identification of potential export motifs on mPRα required for its trafficking to the cell membrane. Collectively, these results have identified several potential mechanisms regulating the expression and functions of mPRs on the cell membrane for further investigation.

Disease burden, comorbidities and antecedents of chronic cough phenotypes in Australian adults

BACKGROUND AND OBJECTIVES

While adult chronic cough has high burden, its phenotypes, particularly those without aetiologically related underlying conditions, are understudied. We investigated the prevalence, lung function and comorbidities of adult chronic cough phenotypes.

METHODS

Data from 3608 participants aged 53 years from the Tasmanian Longitudinal Health Study (TAHS) were included. Chronic cough was defined as cough on most days for >3 months in a year. Chronic cough was classified into "explained cough" if there were any one of four major cough-associated conditions (asthma, COPD, gastroesophageal reflux disease or rhinosinusitis) or "unexplained cough" if none were present. Adjusted regression analyses investigated associations between these chronic cough phenotypes, lung function and non-respiratory comorbidities at 53 years.

RESULTS

The prevalence of chronic cough was 10% (95%CI 9.1,11.0%) with 46.4% being "unexplained". Participants with unexplained chronic cough had lower FEV1/FVC (coefficient: -1.2% [95%CI:-2,3, -0.1]) and increased odds of comorbidities including obesity (OR=1.6 [95%CI: 1.2, 2.3]), depression (OR=1.4 [95%CI: 1.0, 2.1]), hypertension (OR=1.7 [95%CI: 1.2, 2.4]) and angina, heart attack or myocardial infarction to a lesser extent, compared to those without chronic cough. Participants with explained chronic cough also had lower lung function than both those with unexplained chronic cough and those without chronic cough.

CONCLUSIONS

Chronic cough is prevalent in middle-age and a high proportion is unexplained. Unexplained cough contributes to poor lung function and increased comorbidities. Given unexplained chronic cough is not a symptom of major underlying respiratory conditions it should be targeted for better understanding in both clinical settings and research.

Physiotherapy services in intensive care. A workforce survey of Australia and New Zealand

BACKGROUND

In Australia and New Zealand, there are currently no recommendations to guide staffing levels for intensive care unit (ICU) physiotherapy services, and there is limited information about the current services provided.

OBJECTIVES

The objective of this study was to document the profile of intensive care physiotherapy services currently offered in Australia and New Zealand.

METHODS

A binational survey was distributed to physiotherapists. The survey sought information on staffing and service profiles for weekday, weekend, and after-hour services including on-call and evening shifts.

RESULTS

Eighty-six sites completed the survey, with responses primarily from Level 3 (47/86, 55%) and public ICUs (74/86, 86%). For weekday services, the ratio of full-time equivalent physiotherapy staff allocated per bed was similar between all intensive care levels (0.11 [0.08-0.15], p = 0.421). Thirty respondents (35%) were satisfied with their staffing and reported higher levels of physiotherapy staff per bed (0.15 [0.1-0.2], p < 0.001). Most sites reported lower levels of staffing for weekend services (76/86, 88%), and many physiotherapists indicated that they were not satisfied with this service (55/86, 64%). Most Level 2, Level 3, and paediatric ICUs had a designated senior physiotherapist, with similar levels of senior physiotherapy staff allocated per bed between all ICU levels (0.05 [0.03-0.08], p = 0.844). Few sites reported dedicated staff attributed to intensive care education, research, tracheostomy service, or outreach roles. On-call physiotherapy services were available in 49 of 86 (57%) hospitals surveyed; however, utilisation of the service by ICUs was mainly reported to be less than once per month (19/49, 39%).

CONCLUSIONS

Physiotherapy staffing ratios were similar across different ICU levels. While weekend services are available for most ICUs, staffing levels are reduced. Higher staffing ratios were associated with higher levels of satisfaction to complete professional roles and responsibilities.

The membrane androgen receptor ZIP9 (SCL39A9) maintains ovarian homeostasis by mediating post-ovulatory follicle breakdown in zebrafish

ZIP9 was recently characterized as a membrane androgen receptor in Atlantic croaker granulosa/theca (G/T) cells where it mediates androgen-induced apoptosis in vitro, but the physiological significance of this action has remained unclear. In the current study, we utilized ZIP9 knockout (zip9^-/-) zebrafish to investigate the role of ZIP9-mediated androgen-induced G/T cell apoptosis in vivo. We first confirmed ZIP9 mediates apoptosis of zebrafish G/T cells in vitro. Testosterone increased apoptosis, intracellular free zinc, and expression of pro-apoptotic members bax and p53 in wildtype and zip9^+/+ zebrafish G/T cells, but not in ZIP9 knockout and knockdown cell models. We hypothesized ZIP9-mediated G/T cell apoptosis may be involved in post-ovulatory follicle (POF) breakdown in vivo. Post ovulation, zip9, bax, and p53 were upregulated in zip9^+/+ but not in zip9^-/- ovaries. Immunoreactivity of cleaved caspase 3 was also higher in POFs from zip9^+/+ ovaries compared zip9^-/-, and POF breakdown was significantly delayed in zip9^-/- fish compared to zip9^+/+ counterparts. To determine the detrimental consequences of delayed POF breakdown in the zip9^-/- model, fish were challenged with repeated ovulation induction. After the challenge, zip9^-/- fish exhibited abnormal ovarian lesions that contained debris consistent with atretic or necrotic cellular material. However, no abnormalities were observed in zip9^+/+ fish ovaries, indicating that the abnormal phenotype is due to the loss of ZIP9. This study demonstrates an important role for ZIP9 in mediating POF breakdown and maintaining tissue remodeling and homeostasis in the teleost ovary and indicates a role for the ZIP9-mediated androgen-induced apoptotic response in vivo.

Reproductive collapse in European beech results from declining pollination efficiency in large trees

Climate warming increases tree mortality which will require sufficient reproduction to ensure population viability. However, the response of tree reproduction to climate change remains poorly understood. Warming can reduce synchrony and interannual variability of seed production ("masting breakdown") which can increase seed predation and decrease pollination efficiency in trees. Here, using 40 years of observations of individual seed production in European beech (Fagus sylvatica), we showed that masting breakdown results in declining viable seed production over time, in contrast to the positive trend apparent in raw seed count data. Furthermore, tree size modulates the consequences of masting breakdown on viable seed production. While seed predation increased over time mainly in small trees, pollination efficiency disproportionately decreased in larger individuals. Consequently, fecundity declined over time across all size classes, but the overall effect was greatest in large trees. Our study showed that a fundamental biological relationship-correlation between tree size and viable seed production-has been reversed as the climate has warmed. That reversal has diverse consequences for forest dynamics; including for stand- and biogeographical-level dynamics of forest regeneration. The tree size effects suggest management options to increase forest resilience under changing climates.

Central nervous system insulin signaling can influence the rate of insulin influx into brain

BACKGROUND

Insulin transport across the blood-brain barrier (BBB) is a highly regulated, saturable process, known to be affected by many peripheral substrates including insulin itself and triglycerides. This is in contrast to insulin leakage into peripheral tissues. Whether the central nervous system (CNS) can control the rate of insulin uptake by brain remains to be determined. Insulin BBB interactions are impaired in Alzheimer's disease (AD) and CNS insulin resistance is widely prevalent in AD. Therefore, if CNS insulin controls the rate of insulin transport across the BBB, then the defective transport of insulin seen in AD could be one manifestation of the resistance to CNS insulin observed in AD.

METHODS

We investigated whether enhancing CNS insulin levels or induction of CNS insulin resistance using an inhibitor of the insulin receptor altered the blood-to-brain transport of radioactively labeled insulin in young, healthy mice.

RESULTS

We found that insulin injected directly into the brain decreased insulin transport across the BBB for whole brain and the olfactory bulb in male mice, whereas insulin receptor blockade decreased transport in female mice for whole brain and hypothalamus. Intranasal insulin, currently being investigated as a treatment in AD patients, decreased transport across the BBB of the hypothalamus.

CONCLUSIONS

These results suggest CNS insulin can control the rate of insulin brain uptake, connecting CNS insulin resistance to the rate of insulin transport across the BBB.

Impact of a High Observation Trauma Protocol on Patients with Isolated Traumatic Brain Injury

BACKGROUND

Nationally, the volume of geriatric falls with intracranial hemorrhage (ICH) is increasing. Our institution began observing patients with ICH, a GCS ≥ 14, and no midline shift or intraventricular hemorrhage with hourly neurologic examination outside the ICU in a high observation trauma (HOT) protocol. We first excluded patients on anticoagulants/antiplatelets (HOT I), then included antiplatelets and warfarin (HOT II) and finally included direct oral anticoagulants (HOT III). Our hypothesis is that HOT protocol safely reduces ICU utilization and creates cost savings in this patient population.

STUDY DESIGN

Our institutional trauma registry was retrospectively queried for all patients on HOT protocol. Patients were stratified based on date of admission: HOT I (2008-2014), HOT II (2015-2018) and HOT III (2019-2021). Demographics, anticoagulant use, injury characteristics, lengths of stay (LOS), incidence of neuro-intervention, and mortality.

RESULTS

Over the study period, 2343 patients were admitted, including HOT I (n=939), HOT II (n=794), and HOT III (n=610). Of these patients, 331 (35%), 554 (70%), and 495 (81%) were admitted to the floor under HOT protocol. HOT patients required neurointervention in 3.0%, 0.5% and 0.4% of cases over HOT I, II, and III, respectively. Mortality among HOT protocol patients was found to be 0.6% in HOT I, 0.9% in HOT II and 0.2% in the HOT III cohort (p=0.33).

CONCLUSION

Across the study period, ICU utilization decreased without an increase in neurosurgical intervention or mortality indicating the efficacy of the HOT selection criteria in identifying appropriate candidates for stepdown admission and high observation trauma protocol.

Enhancing the Performance of Piezoelectric Wind Energy Harvester Using Curve-Shaped Attachments on the Bluff Body

This paper presents a piezoelectric wind energy harvester that operates by a galloping mechanism with different shaped attachments attached to a bluff body. A comparison is made between harvesters that consist of different shaped attachments on a bluff body; these include triangular, circular, square, Y-shaped, and curve-shaped attachments. Simulation of the pressure field and the velocity field variation around the different shaped bluff bodies is performed and it is found that a high pressure difference creates a high lift force on the bluff body with curve-shaped attachments. A theoretical model based on a galloping mechanism is presented, which is verified by experiments. It is observed that the proposed harvester with curve-shaped attachments provides the best performance, where the harvester with a curve-shaped attachments provides the highest voltage and power output compared to the other shaped harvesters examined in this study. This paper provides a new concept for improving the power performance of the piezoelectric wind energy harvesters with modifications made on the bluff body.

Progesterone exerts a neuroprotective action in a Parkinson's disease human cell model through membrane progesterone receptor α (mPRα/PAQR7)

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide, and current treatment options are unsatisfactory on the long term. Several studies suggest a potential neuroprotective action by female hormones, especially estrogens. The potential role of progestogens, however, is less defined, and no studies have investigated the potential involvement of membrane progesterone receptors (mPRs). In the present study, the putative neuroprotective role for mPRs was investigated in SH-SY5Y cells, using two established pharmacological treatments for cellular PD models, 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpyridinium (MPP+). Our results show that both the physiologic agonist progesterone and the specific mPR agonist Org OD 02-0 were effective in reducing SH-SY5Y cell death induced by 6-OHDA and MPP⁺, whereas the nuclear PR agonist promegestone (R5020) and the GABA_A receptor agonist muscimol were ineffective. Experiments performed with gene silencing technology and selective pharmacological agonists showed that mPRα is the isoform responsible for the neuroprotective effects we observed. Further experiments showed that the PI3K-AKT and MAP kinase signaling pathways are involved in the mPRα-mediated progestogen neuroprotective action in SH-SY5Y cells. These findings suggest that mPRα could play a neuroprotective role in PD pathology and may be a promising target for the development of therapeutic strategies for PD prevention or management.

Typical median effective radiation doses using an anthropomorphic bone fracture phantom for initial radiographic skeletal surveys in the investigation of suspected physical abuse

BACKGROUND

A series of 31 radiographs is recommended by the Royal College of Radiologists (RCR) when investigating suspected physical abuse (SPA).

OBJECTIVE

To determine the radiation dose delivered for skeletal surveys performed for SPA in Victorian radiology departments based on their local protocols.

MATERIALS AND METHODS

A 5-year-old paediatric bone fracture phantom was radiographed at five radiology sites using both the RCR recommended protocol and, where applicable, the local departmental SPA protocol. The radiation doses were measured and recorded. These were scaled down to estimate the effective radiation doses for a 2-year-old child at each site and the associated radiation risks estimated.

RESULTS

The median effective dose for all radiographic projections in the RCR skeletal survey radiographic series was 0.09 mSv. The estimated risk of radiation-induced cancer and radiation-induced death from cancer for 2-year-old children is classified as "very low," with girls having a higher risk than boys.

CONCLUSION

The median effective radiation dose for the RCR skeletal survey for imaging in SPA was 0.09 mSv resulting in a "very low" additional risk of radiation-induced cancer. The authors will now aim to ascertain whether whole-body CT skeletal survey can replace the radiographic series for imaging in SPA while maintaining a comparable radiation dose.

mPRα and PR co-operate in progesterone inhibition of endothelial cell focal adhesion

Progesterone causes vascular smooth muscle cell relaxation through membrane progesterone receptors (mPRs), which are members of the progestin and adipoQ receptor (PAQR) family, and nuclear PRs (nPRs). However, beneficial vascular effects of progesterone in preventing pre-atherosclerosis and the involvement of mPRs and nPRs remain unclear. The results show short- to long-term treatments with 100 nM progesterone (P4) and specific agonists for mPRs, OD 02-0, and nPRs, R5020, inhibited pre-atherosclerotic events in human umbilical vein endothelial cells (HUVECs), decreasing focal adhesion (FA) by monocytes, FA signaling, HUVEC migration and invasion, and vinculin expression. Progesterone and OD 02-0, but not R5020, inhibited phosphorylation of Src and focal adhesion kinase, critical kinases of FA signaling, within 20 min and migration and invasion of HUVECs and monocyte adhesion after 3 h. These inhibitory P4 and 02-0 effects were attenuated with MAP kinase and Pi3k inhibitors, indicating involvement of these kinases in this mPR-mediated action. However, after 16 h, OD 02-0 was no longer effective in inhibiting FA signaling, while both progesterone and R5020 decreased the activity of the two kinases. Knockdown of receptor expression with siRNA confirmed that mPRα mediates short-term and nPR long-term inhibitory effects of progesterone on FA signaling. Thus, progesterone inhibition of FA signaling and pre-atherosclerosis is coordinated through mPRα and nPRs.

An interleukin-1 polymorphism additionally intensified by atopy as prognostic factor for aseptic non-mechanical complications in metal knee and hip arthroplasty

Background

In contrast to infection or mechanical issues joint replacement failure following inflammatory adverse reactions is poorly understood.

Objective

To assess the association of IL-1β polymorphisms and history of allergy with aseptic non-mechanical complications following arthroplasty.

Methods

In 102 patients with aseptic non-mechanically caused symptomatic knee or hip arthroplasty (SA) and 93 patients with asymptomatic arthroplasty (AA) questionnaire-based history, patch test with at least standard series, lymphocyte transformation test (LTT) with nickel, cobalt and chromium and interleukin-1 polymorphism analysis were done. Three polymorphisms of the IL1B gene [IL-1b -3954 (rs1143634), IL-1b -511 (rs16944) and IL-1b -31 (rs1143627)] and one polymorphism of the IL1RN gene [IL1RN intron 2, variable number of tandem repeats, VNTR (rs2234663)] were assessed by PCR and gel electrophoresis.

Results

We found no significant difference in smoking history and atopy but 25% versus 10% of self-reported metal allergy in SA versus AA; the patch test (respective, LTT) for metal sensitivity was more often positive in SA patients. The allele 498 bp of the IL1RN polymorphism occurred significantly more often in the SA group (37% versus 11%; p < 0.0001). Upon additional presence of atopy, the difference was even greater (60% vs 10%) (p < 0.000001). There was no association of IL-1 polymorphisms with metal allergy.

Conclusion

The IL1RN VNTR allele 498 bp was strongly associated with SA. In patients with a history of atopy, presence of the IL1RN VNTR allele 498 bp led to a four-fold higher SA prevalence compared to patients without this allele.

Ventilator hyperinflation - what settings generate an expiratory flow rate bias?

OBJECTIVES

To determine which mechanical ventilation settings influence the attainment of expiratory flow rate characteristics that may promote secretion mobilisation during ventilator hyperinflation (VHI).

DESIGN

Prospective, single centre study.

SETTING

Intensive care unit, tertiary metropolitan hospital.

PARTICIPANTS

Twenty-four patients receiving mechanical ventilation.

INTERVENTIONS

Patients were recruited to either a low PEEP or high PEEP group (5-9 cmH₂O or 10-15 cmH₂O PEEP respectively). Each group had three hyperinflation protocols applied.

MAIN OUTCOME MEASURES

Peak inspiratory flow rates (PIFR) and peak expiratory flow rates (PEFR) were measured and reported as PIFR/PEFR of less than or equal to 0.9; a PEFR-PIFR greater than or equal to 33 L/min; and PEFR greater than or equal to 40 L/min.

RESULTS

In both the low and high PEEP groups, VHI protocols using volume-controlled ventilation were significantly better at generating expiratory flow rate bias compared to pressure-controlled or Pressure Support ventilation. An expiratory flow rate bias was also achieved when VHI was performed in volume-controlled ventilation with either a peak inspiratory pressure target of 35 cmH₂O or a driving pressure of 20 cmH₂O. Median heart rate and blood pressure values did not change during VHI, but transient reductions in blood pressure were present in six participants (25%).

CONCLUSIONS

VHI performed using volume-controlled ventilation was more effective than pressure-controlled or Pressure Support ventilation to generate an expiratory flow rate bias.

CONTRIBUTION OF THE PAPER

Mechanical ventilator settings can be altered to perform hyperinflation and achieve expiratory flow rate properties that may increase the mobilisation of airway secretions. The results demonstrate that to achieve these properties.

RF15 | PMON305 Membrane Progesterone Receptor α (mPRα/PAQR7) Promotes Survival and Axonal Sprouting in Human Neuronal Cells Lines Through Direct and Human Schwann-Cell Like Differentiated Adipose Stem Cells-Mediated Mechanisms

Injuries to peripheral nerves affect millions of people worldwide. These injuries can be significantly detrimental to the patients’ quality of life. While central nervous system neurons have extremely limited regenerative potential, peripheral nerves are able to regenerate after injury. However, this regeneration process often leads to unsatisfactory regenerative outcomes. Improving peripheral nerve regeneration is therefore a strong medical need. Schwann cells, the glial myelinating cells of the peripheral nervous system, are known to play an important role in promoting peripheral nerve regeneration. However, their limited in vitro expansion capability and limited availability has led several research groups to investigate the possibility of using differentiated stem cells as a potential tool to promote nerve regeneration, in association with other tools such biomaterial tubes. The activation of membrane progesterone receptor α (mPRα, PAQR7) with the selective agonist 19-ethenyl-progesterone (02-0) was recently shown to elicit potentially pro-regenerative effects in a model of human Schwann cell-like (SCL) differentiated adipose stem cells (ASC). Indeed, mPRα activation led to increased SCL-ASC migration, proliferation and neurotrophin (specifically BDNF) release. All these outcomes are expected to be beneficial for nerve regeneration. In this project, we investigated the effect of mPRα activation in SCL-ASC on neuronal cell lines to demonstrate that the positive effects previously observed in SCL-ASC have a beneficial effect in neuronal cells. We first investigated how the conditioned medium of untreated SCL-ASC (CM-) and SCL-ASC treated with the selective mPR agonist 02-0 (CM+) affected cell survival and neuronal sprouting in two different neuronal cell lines, IMR-32 and SH-SY-5Y. In both cases, CM- had a beneficial effect, reducing cell death, as assessed in starvation experiments, and promoting axonal sprouting, with the presence of longer cell processes in the two cell models compared to control. In both cases, CM+ had an even stronger effect than CM-, suggesting that mPRα activation may lead to the release of specific molecules that promote nerve regeneration. Moreover, CM- and CM+ treatments were effective in increasing the gene expression of selected peripheral regeneration markers (CREB3, ATF3 and GAP46) in SH-SY-5Y cells. Since mPR receptors are present in neuronal cells, we performed another series of cell death and axonal sprouting experiments in SH-SY-5Y6 cells, comparing CM- and CM+ effects to an experimental group in which 02-0 was added to CM- after incubation with SCL-ASC. These experiments showed that the effect on cell death was mostly due to direct activation of mPR receptors in neuronal cells. On the other hand, the effect on axonal sprouting depended on mPRα activation in SCL-ASC and subsequent release of active molecules in the medium. Our results support the hypothesis that mPRα activation in SCL-ASC may represent a promising pharmacological target to promote peripheral nerve regeneration.

Presentation: Sunday, June 12, 2022 12:42 p.m. - 12:47 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

P-039 COMPOSITE PP/PLLA MONOFILAMENT 4DVENTRAL® PROMOTES AN ANTI-INFLAMMATORY RESPONSE FROM HUMAN MACROPHAGES IN VITRO

The repair of abdominal hernias with prosthetic mesh can significantly reduce the risk of hernia recurrence. A new type of hernia implants combines monofilaments, Polypropylene (PP) and a biobased and natural slowly bioabsorbable polymer, Poly-L-Lactic Acid (PLLA). The partially (60%) resorbable PLLA/PP and PP meshes manufactured by COUSIN Surgery are 4DVentral® and Biomesh P1®. The contribution of PLLA in regulated inflammatory response and in enhancing abdominal repair remains unknown. Inflammation has a functional role during tissue regeneration process. An abnormal macrophage response characterized by an uncontrolled release of pro-inflammatory cytokines, chemokines, and tissue-degrading enzymes has been shown to be responsible for postoperative complications. In contrast, the angiogenic and tissue remodeling activities of the alternative anti-inflammatory M2 macrophages have potential use in tissue regenerative. Here, the characterization of the inflammatory response of human macrophages in vitro regarding 4DVentral® compared to Biomesh P1® was performed. Human monocytic THP-1 cells were differentiated into macrophages and polarized in M1 macrophages by incubation with IFN-γ and LPS or not (M0 macrophages). We found that 4DVentral® induced higher secretion of anti-inflammatory cytokines (IL-10 and Il1-RA) compared to PP Mesh in M0 macrophages. Interestingly, the secretion of pro-inflammatory cytokine IL-6 in M1 macrophages was dramatically reduced in the presence of 4DVentral® mesh compared to PP Biomesh P1®. However, the secretion of IL-10 was significantly increased with 4DVentral®. The composite PLLA/PP monofilament 4DVentral® positively drives human macrophages to an anti-inflammatory profile, resolving inflammation and promoting tissue repair.

Functions of Membrane Progesterone Receptors (mPRs, PAQRs) in Nonreproductive Tissues

Gender differences in a wide variety of physiological parameters have implicated the ovarian hormones, estrogens and progesterone, in the regulation of numerous nonreproductive tissue functions. Rapid, nongenomic (nonclassical) progesterone actions mediated by membrane progesterone receptors (mPRs), which belong to the progestin and adipoQ receptor family, have been extensively investigated in reproductive and nonreproductive tissues since their discovery in fish ovaries 20 years ago. The 5 mPR subtypes (α, β, γ, δ, ε) are widely distributed in vertebrate tissues and are often expressed in the same cells as the nuclear progesterone receptor (PR) and progesterone receptor membrane component 1, thereby complicating investigations of mPR-specific functions. Nevertheless, mPR-mediated progesterone actions have been identified in a wide range of reproductive and nonreproductive tissues and distinguished from nuclear PR-mediated ones by knockdown of these receptors with siRNA in combination with a pharmacological approach using mPR- and PR-specific agonists. There are several recent reviews on the roles of the mPRs in vertebrate reproduction and cancer, but there have been no comprehensive assessments of mPR functions in nonreproductive tissues. Therefore, this article briefly reviews mPR functions in a broad range of nonreproductive tissues. The evidence that mPRs mediate progesterone and progestogen effects on neuroprotection, lordosis behavior, respiratory control of apnea, olfactory responses to pheromones, peripheral nerve regeneration, regulation of prolactin secretion in prolactinoma, immune functions, and protective functions in vascular endothelial and smooth muscle cells is critically reviewed. The ubiquitous expression of mPRs in vertebrate tissues suggests mPRs regulate many additional nonreproductive functions that remain to be identified.

Chitosan-Modified Biochars to Advance Research on Heavy Metal Ion Removal: Roles, Mechanism and Perspectives

The chitosan-modified biochars BC-CS 1-1, BC-CS 2-1 and BC-CS 4-1 were subjected to the synthetic application of biochar from agriculture waste and chitosan for the adsorption of Cu(II), Cd(II), Zn(II), Co(II) and Pb(II) ions from aqueous media. The results displayed a heterogeneous, well-developed surface. Additionally, the surface functional groups carboxyl, hydroxyl and phenol, determining the sorption mechanism and confirming the thermal stability of the materials, were present. The sorption evaluation was carried out as a function of the sorbent dose, pH, phase contact time, initial concentration of the solution and temperature. The maximum value of q_t for Pb(II)-BC-CS 4-1, 32.23 mg/g (C₀ 200 mg/L, mass 0.1 g, pH 5, 360 min), was identified. Nitric acid was applied for the sorbent regeneration with a yield of 99.13% for Pb(II)-BC-CS 2-1. The produced sorbents can be used for the decontamination of water by means of the cost-effective and high-performance method.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Annual adult survival rates for four sympatric breeding swallow species: effects of environmental factors and density-dependence

Swallow (Family: Hirundinidae) populations in the Canadian Maritimes have declined since the 1980s. Using mark-recapture data from 2012–2019, we determined apparent annual adult survival rates for Barn Hirundo rustica Linnaeus, 1758, Tree Tachycineta bicolor Vieillot, 1808, Bank Riparia riparia Linnaeus, 1758, and Cliff swallows Petrochelidon pyrrhonota Vieillot, 1817. For two data-rich species (Barn and Tree swallows), we modelled the relationships between survival and weather (cold snaps, precipitation, temperature, and wind speed); climate (El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO)); Enhanced Vegetation Index (EVI) as a measure of primary productivity during the winter; number of active nests as a measure of site quality; and the Breeding Bird Survey (BBS) annual population index as density dependent processes. Survival rates for all four species were typically higher (Barn and Tree) or similar to (Cliff and Bank) of estimates from populations that have not undergone severe, long-term declines. Across weather and climate variables, conditions that are typically favourable for high insect availability (e.g., higher precipitation, warmer temperatures and lower wind speeds) resulted in higher survival. For female Barn and Tree Swallows, survival was higher when EVI was lower, and for Barn Swallows, survival was also higher when the BBS index was higher. Collectively our results demonstrate that conditions throughout the annual cycle affect survival, and the relationships with weather and climate variables support the importance of high insect availability

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

The many reasons of poor performance/more pertinent reasons for poor student performance

No abstract available.

[Simulation-based training for a hospital incident command group]

BACKGROUND

We report on immersive simulation scenarios with video-enhanced debriefing as part of a full day education program for members of a newly implemented hospital incident command group. The hospital incident command group has a key function in the initial phase of a hospital crisis. Simulation exercises were used to provide practical experience for the participants in a yet unknown task area and to support the acquisition of professional and personal competencies.

OBJECTIVES

Are immersive simulation scenarios with video-enhanced debriefing a suitable method as part of an education program to change the perceptions of participants about their tasks and enhance their motivation to assume leadership positions?

MATERIALS AND METHODS

Participants of a 1‑day educational workshop completed immersive simulation scenarios during which they took on roles and responsibilities of a hospital incident command group. A final questionnaire with a 5-point Likert scale was used to capture changes in specific knowledge and perceptions as a result of the simulation experience.

RESULTS AND CONCLUSION

The vast majority of participants assessed the immersive simulation scenarios as effective in changing their perceptions and to motivate them to become part of a hospital incident command group. Simulation with video-enhanced debriefing is a suitable method for providing professional and personal competencies to members of a hospital incident command group.

Sonophotocatalytic Dye Degradation Using rGO-BiVO4 Composites

Reduced graphene oxide (rGO)/bismuth vanadate BiVO₄ composites are fabricated with varied rGO amounts (0, 1, 2, and 3 wt%) through the synergetic effects of ultrasonication, photoinduced reduction, and hydrothermal methods, and the materials are tested as tools for sonophotocatalytic methylene blue (MB) dye degradation. The effect of rGO content on the sonophotocatalytic dye degradation capabilities of the composites are explored. Characterization of the proposed materials is done through transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transformation infrared spectroscopy as well as scanning electron microscopy. The coexistence of BiVO₄ and rGO is confirmed using Raman spectroscopy and XRD. TEM confirms the existence of interfaces between rGO and BiVO₄ and XPS affirms the existence of varied elemental oxidation states. In order to investigate the charge carriers transportation, time-dependent photocurrent responses of BiVO₄ and 2 wt%- rGO/BiVO₄ are done under visible light irradiation. The sonophotocatalytic MB dye degradation in an aqueous medium displays promising enhancement with rGO doping in rGO/BiVO₄ composite. The 2 wt%- rGO/BiVO₄ sample exhibits ≈52% MB dye degradation efficiency as compared to pure BiVO4 (≈25%) in 180 min of the sonophotocatalysis experiment. Phytotoxicity analysis through germination index is done using vigna radiata seeds.

Membrane Progesterone Receptors (mPRs, PAQRs): Review of Structural and Signaling Characteristics

The role of membrane progesterone receptors (mPRs), which belong to the progestin and adipoQ receptor (PAQR) family, in mediating rapid, nongenomic (non-classical) progestogen actions has been extensively studied since their identification 20 years ago. Although the mPRs have been implicated in progestogen regulation of numerous reproductive and non-reproductive functions in vertebrates, several critical aspects of their structure and signaling functions have been unresolved until recently and remain the subject of considerable debate. This paper briefly reviews recent developments in our understanding of the structure and functional characteristics of mPRs. The proposed membrane topology of mPRα, the structure of its ligand-binding site, and the binding affinities of steroids were predicted from homology modeling based on the structures of other PAQRs, adiponectin receptors, and confirmed by mutational analysis and ligand-binding assays. Extensive data demonstrating that mPR-dependent progestogen regulation of intracellular signaling through mPRs is mediated by activation of G proteins are reviewed. Close association of mPRα with progesterone membrane receptor component 1 (PGRMC1), its role as an adaptor protein to mediate cell-surface expression of mPRα and mPRα-dependent progestogen signaling has been demonstrated in several vertebrate models. In addition, evidence is presented that mPRs can regulate the activity of other hormone receptors.

Comparison of 6-Month Outcomes of Survivors of COVID-19 versus Non-COVID-19 Critical Illness

Rationale: The outcomes of survivors of critical illness due to coronavirus disease (COVID-19) compared with non-COVID-19 are yet to be established. Objectives: We aimed to investigate new disability at 6 months in mechanically ventilated patients admitted to Australian ICUs with COVID-19 compared with non-COVID-19. Methods: We included critically ill patients with COVID-19 and non-COVID-19 from two prospective observational studies. Patients were eligible if they were adult (age ⩾ 8 yr) and received ⩾24 hours of mechanical ventilation. In addition, patients with COVID-19 were eligible with a positive laboratory PCR test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Measurements and Main Results: Demographic, intervention, and hospital outcome data were obtained from electronic medical records. Survivors were contacted by telephone for functional outcomes with trained outcome assessors using the World Health Organization Disability Assessment Schedule 2.0. Between March 6, 2020, and April 21, 2021, 120 critically ill patients with COVID-19, and between August 2017 and January 2019, 199 critically ill patients without COVID-19, fulfilled the inclusion criteria. Patients with COVID-19 were older (median [interquartile range], 62 [55-71] vs. 58 [44-69] yr; P = 0.019) with a lower Acute Physiology and Chronic Health Evaluation II score (17 [13-20] vs. 19 [15-23]; P = 0.011). Although duration of ventilation was longer in patients with COVID-19 than in those without COVID-19 (12 [5-19] vs. 4.8 [2.3-8.8] d; P < 0.001), 180-day mortality was similar between the groups (39/120 [32.5%] vs. 70/199 [35.2%]; P = 0.715). The incidence of death or new disability at 180 days was similar (58/93 [62.4%] vs. 99/150 [66/0%]; P = 0.583). Conclusions: At 6 months, there was no difference in new disability for patients requiring mechanical ventilation for acute respiratory failure due to COVID-19 compared with non-COVID-19. Clinical trial registered with www.clinicaltrials.gov (NCT04401254).

Cerebrovascular Disease Profiles of Culturally and Linguistically Diverse Communities in South Western Sydney and New South Wales

INTRODUCTION

Culturally and linguistically diverse (CALD) communities are growing globally. Understanding patterns of cerebrovascular disease in CALD communities may improve health outcomes through culturally specific interventions. We compared rates of transient ischaemic attack (TIA)/stroke (ischaemic stroke, intracerebral haemorrhage) and stroke risk factor prevalence in overseas and Australian-born people in South Western Sydney (SWS) and New South Wales (NSW).

METHODS

This was a 10-year retrospective analysis (2011-2020) of SWS and NSW age-standardized rates per 100,000 person-years of TIA/stroke. Data were extracted from Health Information Exchange and Secure Analytics for Population Health Research and Intelligence systems. Rates of hypertension, type 2 diabetes mellitus (T2DM), atrial fibrillation (AF), smoking, and obesity were also calculated.

RESULTS

The SWS and NSW age-standardized rate of TIA/stroke for people born in Australia was 100 per 100,000 person-years (100/100,000/year). In SWS, 56.6% of people were overseas-born compared to 29.8% for NSW. The age-standardized rate of TIA/stroke for Polynesian-born people was more than double that of Australian-born people (p < 0.001). Hypertension (33 [SWS] vs. 27/100,000/year [NSW]) and T2DM (36 [SWS] vs. 26/100,000/year [NSW]) were the most common risk factors with rates >50/100,000/year (hypertension) and >80/100,000/year (T2DM) for people born in Polynesia, Melanesia, and Central America. Rates of T2DM, AF, and obesity for Polynesian-born people were over threefold greater than people born in Australia.

DISCUSSION/CONCLUSION

Greater rates of TIA/stroke were observed in specific CALD communities, with increased rates of cerebrovascular risk factors. Culturally specific, targeted interventions may bridge health inequalities in cerebrovascular disease.

Molecular modeling, mutational analysis and steroid specificity of the ligand binding pocket of mPRα (PAQR7): Shared ligand binding with AdipoR1 and its structural basis

The 7-transmembrane architecture of adiponectin receptors (AdipoRs), determined from their X-ray crystal structures, was used for homology modeling of another progesterone and adipoQ receptor (PAQR) family member, membrane progesterone receptor alpha (mPRα). The mPRα model identified excess positively charged residues on the cytosolic side, suggesting it has the same membrane orientation as AdipoRs with an intracellular N-terminus. The homology model showed identical amino acid residues to those forming the zinc binding pocket in AdipoRs, which strongly implies that zinc is also present in mPRα. The homology model showed a critical H-bond interaction between the glutamine (Q) residue at 206 in the binding pocket and the 20-carbonyl of progesterone. Mutational analysis showed no progesterone binding to the arginine (R) 206 mutant and modeling predicted this was due to the strong positive charge of arginine stabilizing the presence of an oleic acid (C18:1) molecule in the binding pocket, as observed in the X-rays of AdipoRs. High Zn²⁺ concentrations are predicted to form a salt with the carboxylate group of the oleic acid, thereby eliminating its binding to the free fatty acid (FFA) binding pocket, and allowing progesterone to bind. This is supported by experiments showing 100 µM Zn²⁺ addition restored [³H]-progesterone binding of the Q206R mutant to levels in WT mPRα and increased [³H]-progesterone binding to mPRγ and AdipoR1 which have arginine residues in this region. The model predicts hydrophobic interactions of progesterone with amino acid residues surrounding the binding pocket, including valine 146 in TM3, which when mutated into a polar serine resulted in a complete loss of [³H]-progesterone binding. The mPRα model showed there is no hydrogen bond donor in the vicinity of the 3-keto group of progesterone and ligand structure-activity studies with 3-deoxy steroids revealed that, unlike the nuclear progesterone receptor, the 3-carbonyl oxygen is not essential for binding to mPRα. Interestingly, the small synthetic AdipoR agonist, AdipoRon, displayed binding affinity for mPRα and mimicked progesterone signaling, whereas D-e-MAPP, a ceramidase inhibitor, blocked progesterone signaling. Thus, critical residues around the binding pocket and steroid structures that bind mPRα, as well as similarities with AdipoRs, can be predicted from the homology model.

27-Hydroxycholesterol Binds GPER and Induces Progression of Estrogen Receptor-Negative Breast Cancer

Simple Summary

Breast cancer is the most common cancer in women, and there is a known link between high cholesterol levels and breast cancer. However, how cholesterol impacts breast cancer is poorly understood, particularly in the case of an aggressive form of cancer known as estrogen receptor negative breast cancer. Using cells in culture and models of breast tumors in mice, we have determined that an abundant metabolite of cholesterol known as 27-hydroxycholesterol stimulates estrogen receptor negative breast cancer growth. We have also determined how 27-hydroxycholesterol stimulates the growth, identifying a new mechanism of action of 27-hydroxycholesterol. These new findings may explain the link between high cholesterol and estrogen receptor negative breast cancer, and they may lead to the development of new therapies for a type of breast cancer that presently lacks specific treatments.

Abstract

Cholesterol affects the proliferation of breast cancer (BC) and in particular of estrogen receptor-negative (ER−) BC. Cholesterol is converted to 27-hydroxycholesterol (27HC), which promotes the growth of ER+ BC. Potentially, 27HC can be involved in cholesterol-dependent ER− BC proliferation. Stable MDA-MB-231 silenced clones for CYP7B1 (27HC metabolizing enzyme) show an increased basal proliferation rate, which is not observed in the presence of lipoprotein-deprived serum. Furthermore, the treatment of SKBR3, MDA-MB-231 and MDA-MB-468 with 27HC increased cell proliferation that was prevented by G15, a selective G Protein-Coupled Estrogen Receptor (GPER) inhibitor, suggested this receptor to be a potential 27HC target. Binding experiments demonstrate that 27HC is a new ligand for GPER. We show that ERK1/2 and NFκB are part of the 27HC/GPER pathway. The stable silencing of GPER prevents NFκB activation and reduces basal and 27HC-dependent tumor growth. Additionally, conditioned medium from ER− BC cells treated with 27HC promotes tube formation, which does not occur with CM from GPER silenced cells. Collectively, these data demonstrate that cholesterol conversion into 27HC promotes ER− BC growth and progression, and the expression of GPER is required for its effects.

Clinical outcomes following reperfusion therapy in acute ischemic stroke patients with infective endocarditis: a systematic review

Background

Acute ischemic stroke (AIS) is a common and fatal complication of infective endocarditis (IE); however, there is a lack of understanding regarding treatment efficacy. This systematic review aimed to evaluate the safety and efficacy of intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) in IE patients experiencing AIS.

Objectives

The aim of this study was to perform a systematic review investigating the outcomes of AIS in IE patients receiving IVT and/or EVT as a treatment method and to evaluate the safety and efficacy of these methods of reperfusion therapy.

Design

A systematic review in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines was conducted.

Data Sources and Methods

The EMBASE, Cochrane, and PubMed databases were searched for literature published between 2005 and 2021 investigating outcomes of reperfusion therapy post-AIS in IE and non-IE patients. Descriptive statistics were used to describe the overall frequency of clinical outcomes, and groupwise comparisons were performed using Fisher’s exact test to assess the significance of groupwise differences.

Results

Three studies were finally included in the systematic review. A total of 13.5% of IE patients compared to 37% of non-IE patients achieved a good functional outcome (modified Rankin Scale score≤ 2) (P < .001). Furthermore, a larger percentage of the IE cohort achieved good functional outcomes after EVT (22.0%) compared to IVT (10.4%) (P = .013). The IE cohort also had a higher 3-month postreperfusion mortality rate (48.8%) compared to the non-IE cohort (24.9%) (P < .001). The rate of intracranial hemorrhage (ICH) postreperfusion was also significantly higher in the IE cohort (23.5%) than in the non-IE cohort (6.5%) (P < .001).

Conclusion

AIS patients with IE, treated with IVT, EVT, or a combination of the two, experience worse clinical and safety outcomes than non-IE patients. EVT yielded better functional outcomes, albeit with higher postreperfusion ICH rates, than IVT.

National diagnostic reference levels: What they are, why we need them and what's next

Diagnostic reference levels (DRLs) are an optimisation tool for medical imaging procedures using ionising radiation. They give an indication of the expected radiation dose received by an average-sized patient undergoing a given imaging procedure. Comparison of typical (median) exposure levels for common imaging procedures with DRLs helps imaging facilities identify procedures that may be amenable to further optimisation. Undertaking comparisons with published DRLs is a requirement for medical imaging facilities under the Code for Radiation Protection in Medical Exposure and for their access to Medicare rebates under the Diagnostic Imaging Accreditation Scheme (DIAS). The Australian Radiation Protection and Nuclear Safety Agency has created the National Diagnostic Reference Level Service to facilitate the collection of data for the establishment of national DRLs in Australia and to assist imaging facilities in comparing their typical doses with the national DRLs. National DRLs have been established in computed tomography, nuclear medicine, and for image-guided and interventional procedures. DRLs must be subject to ongoing review and revision by the national authority to ensure they reflect current practice. This ongoing cycle of assessment and review helps to ensure that the ratio of benefit to risk for patients is maximised.

Nationwide Survey of Trauma Center Screening and Intervention Practices for Posttraumatic Stress Disorder, Firearm Violence, Mental Health, and Substance Use Disorders

BACKGROUND

Posttraumatic stress disorder (PTSD) symptoms, firearm violence events, alcohol and drug use problems, and major depression and suicidal ideation are endemic among patients admitted to US trauma centers. Despite increasing policy importance, the current availability of screening and intervention services for this constellation of conditions in US trauma centers is unknown.

STUDY DESIGN

Trauma program staff at all Level I and Level II trauma centers in the US. (N = 627) were contacted to complete a survey describing screening and intervention procedures for alcohol and drug use problems, PTSD symptoms, depression and suicidality, and firearm violence. Additional questions asked trauma centers about the delivery of peer interventions and information technology capacity for screening and intervention procedures.

RESULTS

Fifty-one percent of trauma centers (n = 322) responded to the survey. More than 95% of responding sites endorsed routinely screening and/or intervening for alcohol use problems. Routine services addressing PTSD were less common, with 28% of centers reporting routine screening. More than 50% of sites that screened for PTSD used previously established trauma center alcohol use services. Programmatic screening and intervention for firearm injury sequelae was occurring at 30% of sites.

CONCLUSION

Alcohol screening and intervention is occurring frequently at US trauma centers and appears to be responsive to American College of Surgeons Committee on Trauma verification requirements. Routine screening and intervention services for PTSD and firearm injury were occurring less frequently. Regular national surveys may be a key element of tracking progress in national mental health and substance use screening, intervention, and referral policy.

Dropping the non-core subjects from undergraduate final professional examination: How it would impact the results

INTRODUCTION

Observing the dearth of distinctions in the two decades of final professional medical examinations (FPE) caused concern. Multiple True False (MTF) tests with penalty scoring pulling down the scores was considered one reason. Another possible reason was having too many subjects covered in the MTF and Best Answer Question (BAQ) papers. This study aimed to explore the impact of dropping the non-core subjects with minimal inputs from MTF and BAQ papers and the students' views in this regard.

MATERIALS AND METHODS

We examined the students' performance in the core and non-core subjects in MTF and BAQ papers and the impact of dropping the non-core subjects' contribution to the students' scores of the recent four final professional examinations. We also surveyed the opinions of the students, who took the FPE in the year 2000.

RESULTS

The failure rates were significantly higher in noncore than core subjects (p < 0.001) except in one MTF paper. The mean scores were significantly lower in non-core than core subjects in all the four FPEs (p < 0.05) except in one MTF paper. Dropping the non-core subject items from MTF and BAQ showed an improvement in the scores of MTF, theory total, and most grand totals resulting in two more students reaching distinction status. A mere 3.8% of the students could thoroughly revise the non-core subjects before the FPE. Two-fifth of them believed that non-core subjects had a significant impact on theory performance. Only 31.5% favoured dropping the non-core subjects, and an equal number preferred a status quo, while the rest suggested a reduction in their weightage.

CONCLUSION

Most of the students considered the non-core subjects important in their career. However, very few of them could revise these subjects for the professional examination. The study demonstrated that dropping the non-core subjects from MTF and BAQ improved the students' final scores and helped more students to attain distinction status.

Contact sensitization to iron - a potentially underestimated metal allergen and elicitor of complications in patients with metal implants

BACKGROUND

Little is known about sensitization to iron (Fe) in private, working and medical settings, particulary implantology.

OBJECTIVES

To investigate sensitization to metals, particularly to Fe, both in pre-implant individuals with presumed metal allergy and in patients with suspected metal implant allergy. To further characterize Fe-sensitized individuals.

METHODS

Analysis of patch test reactions to an Fe (II)-sulfate-containing metal series in 183 consecutive patients (41 pre-implant, 142 metal implant-bearers). Test readings on D2, D3 and D6. Evaluation of questionnaire-aided history, of metal reactivity patterns, and demographics of Fe-reactors.

RESULTS

Metal reactivity in pre-implant/implant/total group was: to nickel 39%/30%/32%; to cobalt 17%/15%/15%; to chromium 7%/13%/11%. Co-sensitizations cobalt/nickel (19/58) and cobalt/chromium (11/21) were significant at P < .001; co-sensitizations Fe/Nickel (4/10) and chromium/knee arthroplasty (11/73) at P = .03. Ten of 183 (5.5%) reacted to Fe (2 of 41 pre-implant patients, 8 of 142 implant-bearers) with 10 only reacting on D6. Fe-reactivity was highest in complicated knee arthroplasty (7/73). Further peculiarities of Fe reactors included frequent isolated Fe reactivity (6/10), occupational metal exposure (7/10), previous (par)enteral Fe-substitution (6/10).

CONCLUSIONS

The 5.5% prevalence of Fe-reactions suggests a potentially underestimated role of this metal allergen in general and in implant-bearers. The latter also show a distinct metal sensitization pattern. This article is protected by copyright. All rights reserved.