Disposable paper electrodes for detection of changes in dopamine concentrations in rat brain homogenates

Dopamine, the main catecholamine neurotransmitter plays an important role in renal, cardiovascular, central nervous systems, and pathophysiological processes. The abnormal dopamine levels can result in neurological disorders such as Parkinson's, Alzheimer's, schizophrenia, acute anxiety, neuroblastoma and also contribute to cognitive dysfunctions. Given the widespread importance of dopamine concentration levels, it is imperative to develop sensors that are able to monitor dopamine. Herein, we have developed pre-anodized disposable paper electrode modified with 1-pyrenebutyric acid, for the selective and sensitive determination of dopamine. The sensor was characterized with Fourier transform infrared spectroscopy, Energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and electrochemical techniques for addressing the robust formation and electrochemical activity. The modified electrode exhibited excellent electrocatalytic activity towards dopamine without the common interference from ascorbic acid. The calibration plot for the dopamine sensor resulted linear range from 0.003 μM to 0.5 μM with a detection limit of 0.11 nM. The sensor's potential utility was tested by monitoring dopamine concentration changes in rat brain homogenates when subjected to neurotoxicity. The developed sensor was validated with gold-standard UV-Vis spectroscopy studies and computational studies were performed to understand the interaction between 1-pyrenebutyric acid and dopamine.

Triplet Rydberg States of Aluminum Monofluoride

Aluminum monofluoride (AlF) is a suitable molecule for laser cooling and trapping. Such experiments require extensive spectroscopic characterization of the electronic structure. Two of the theoretically predicted higher-lying triplet states of AlF, the counterparts of the well-characterized D1Δ and E1Π states, had not been experimentally identified yet. We here report on the characterization of the d3Π (v = 0-6) and e3Δ (v = 0-2) states, confirming the predicted energetic ordering of these states (J. Chem. Phys. 1988, 88, 5715-5725), as well as of the f3Σ+ (v = 0-2) state. The transition intensity of the d3Π, v = 3 - a3Π, v = 3 band is negligibly small. This band gets its weak, unexpected rotational structure via intensity borrowing from the nearby e3Δ, v = 2 - a3Π, v = 3 band, made possible via spin-orbit and spin-rotation interaction between the d3Π and e3Δ states. This interaction affects the equilibrium rotational constants in both states; their deperturbed values yield equilibrium internuclear distances that are consistent with the observations. We determined the ionization potential of AlF to be 78,492(1) cm-1 by ionization from the d3Π state.

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

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

Estimating meaningful change thresholds for Skin Pain-Numeric Rating Scale, Sleep-Numeric Rating Scale and Dermatology Life Quality Index in patients with prurigo nodularis

BACKGROUND

Prurigo nodularis (PN) is characterized by intensely itchy nodules/lesions and skin pain, which can have a substantial impact on health-related quality of life (HRQoL). Treatment benefits on such symptoms and impacts are best assessed in trials using patient-reported outcome (PROs) instruments such as Skin Pain Numerical Rating Scale (NRS), Sleep-NRS and Dermatology Life Quality Index (DLQI). However, no guidance exists for interpreting meaningful changes in scores using these PROs in patients with PN.

OBJECTIVES

The main objective was to derive within-patient (responder definition) and between-group improvement thresholds for interpreting Skin Pain-NRS, Sleep-NRS and DLQI total scores in patients with PN. The measurement properties of the three PROs were also evaluated.

METHODS

Intention-to-treat (ITT), blinded and pooled data were used from the Phase 3 PRIME (NCT04183335) and PRIME2 (NCT04202679) studies evaluating the efficacy of dupilumab in adult patients with PN. Anchor- and distribution-based methods were applied to derive responder definition and between-group thresholds for Skin Pain-NRS, Sleep-NRS and DLQI. Data were additionally used to examine the instrument measurement properties, including reliability, validity and responsiveness.

RESULTS

A total of 311 patients (mean age 49.5 years, 65.3% female) were included in the pooled ITT population. The within-patient improvement threshold for Skin Pain-NRS was estimated as 4.0 points, 2.0 points for Sleep-NRS and 9.0 points for DLQI total score. A 1.5-point improvement in Skin Pain-NRS scores, 1.0-point in Sleep-NRS and 4.0-point in DLQI indicated a between-group meaningful change. Adequate to good psychometric properties were demonstrated for all three instruments.

CONCLUSIONS

The results of this study can aid interpretation of Skin Pain-NRS, Sleep-NRS and DLQI scores in patients with PN in both clinical trials and clinical practice to better understand and treat PN-related skin pain and the impact of PN on sleep quality and HRQoL.

An established abdominal wall multidisciplinary team improves patient care and aids surgical decision making with complex ventral hernia patients

INTRODUCTION

Abdominal wall reconstruction (AWR) is an emerging subspecialty within general surgery. The practice of multidisciplinary team (MDT) meetings to aid decision making and improve patient care has been demonstrated, with widespread acceptance. This study presents our initial experience of over 150 cases of complex hernia patients discussed in a newly established MDT setting.

METHODS

From February 2020 to July 2022 (30-month period), abdominal wall MDTs were held bimonthly. Key stakeholders included upper and lower gastrointestinal surgeons, a gastrointestinal specialist radiologist, a plastic surgeon, a high-risk anaesthetist and two junior doctors integrated into the AWR clinical team. Meetings were held online, where patient history, past medical and surgical history, hernia characteristics and up-to-date computed tomography scans were discussed.

RESULTS

Some 156 patients were discussed over 18 meetings within the above period. Ninety-five (61%) patients were recommended for surgery, and 61 (39%) patients were recommended for conservative management or referred elsewhere. Seventy-eight (82%) patients were directly waitlisted, whereas seventeen (18%) required preoperative optimisation: three (18%) for smoking cessation, eleven (65%) for weight-loss management and three (18%) for specialist diabetic assessment and management. In total, 92 (59%) patients (including operative and nonoperative management) have been discharged to primary care.

DISCUSSION

A multidisciplinary forum for complex abdominal wall patients is a safe process that facilitates decision making, promotes education and improves patient care. As the AWR subspecialty evolves, our view is that the "complex hernia MDT" will become commonplace. We present our experience and share advice for others planning to establish an AWR centre.

Maximizing use of existing carcinogenicity data to support acceptable intake levels for mutagenic impurities in pharmaceuticals: Learnings from N-nitrosamine case studies

The unexpected finding of N-nitrosamine (NA) impurities in many pharmaceutical products raised significant challenges for industry and regulators. In addition to well-studied small molecular weight NAs, many of which are potent rodent carcinogens, novel NAs associated with active pharmaceutical ingredients have been found, many of which have limited or no safety data. A tiered approach to establishing Acceptable Intake (AI) limits for NA impurities has been established using chemical-specific data, read-across, or a class-specific TTC limit. There are ∼140 NAs with some rodent carcinogenicity data, but much of it is older and does not meet current guidelines for what constitutes a 'robust' bioassay. Nevertheless, these data are an important source of information to ensure the best science is used for assessing NA impurities and assuring consumer safety while minimizing impact that can lead to drug shortages. We present several strategies to maximize the use of imperfect data including using a lower confidence limit on a rodent TD50, and leveraging data from multiple NAs. Information on the chemical structure known to impact potency can also support development of an AI or potentially conclude that a particular NA does not fall in the cohort of concern for potent carcinogenicity.

Experimental determination of concentration factors of Ni, Ru and Sb in the model diatom Phaeodactylum tricornutum

This paper describes the experimental determination of concentration factors (CF) for nickel, ruthenium and antimony in the model diatom Phaeodactylum tricornutum Bohlin (Bacillariophyceae), which was chosen as a representative of marine phytoplankton. Better determinations of these CF are needed to improve the modelling of marine ecosystems at release points, where radioactive pollutants enter the ecosystem, for more accurate predictions of radiation dose to humans caused by these pollutants. A literature study revealed that the currently implemented values of these CF are based on very scarce data, and a computational sensitivity study showed that the radiation dose caused by radioisotopes of these elements depend strongly on the phytoplankton CF. Nutrient-enriched water samples from Swedish coastal waters were used as a medium for growing of the diatom species P. tricornutum and radioactive isotopes of the studied elements were added to the cultures during the exponential growth phase. The radioactivity in the P. tricornutum and in the culture medium were measured separately and used for determination of CF. Conservative estimates of the CF based on this phytoplankton proxy on the present data are 6400 L/kg for nickel, 20,000 L/kg for ruthenium and 890 L/kg for antimony, with P. tricornutum biomass masses referring to dry weight. The estimates for nickel and ruthenium are similar to previously published values, which underpins the credibility of radiation dose calculations based on these values. The estimate for antimony is uncertain, but also, to our knowledge, represents the first published experimentally based data on this CF.

A portable primary-standard level graphite calorimeter for absolute dosimetry in clinical pencil beam scanning proton beams

Objective. To report the use of a portable primary standard level graphite calorimeter for direct dose determination in clinical pencil beam scanning proton beams, which forms part of the recommendations of the proposed Institute of Physics and Engineering in Medicine (IPEM) Code of Practice (CoP) for proton therapy dosimetry.Approach. The primary standard proton calorimeter (PSPC) was developed at the National Physical Laboratory (NPL) and measurements were performed at four clinical proton therapy facilities that use pencil beam scanning for beam delivery. Correction factors for the presence of impurities and vacuum gaps were calculated and applied, as well as dose conversion factors to obtain dose to water. Measurements were performed in the middle of 10 × 10 × 10 cm3homogeneous dose volumes, centred at 10.0, 15.0 and 25.0 g·cm-2depth in water. The absorbed dose to water determined with the calorimeter was compared to the dose obtained using PTW Roos-type ionisation chambers calibrated in terms of absorbed dose to water in60Co applying the recommendations in the IAEA TRS-398 CoP.Main results.The relative dose difference between the two protocols varied between 0.4% and 2.1% depending on the facility. The reported overall uncertainty in the determination of absorbed dose to water using the calorimeter is 0.9% (k= 1), which corresponds to a significant reduction of uncertainty in comparison with the TRS-398 CoP (currently with an uncertainty equal or larger than 2.0% (k= 1) for proton beams).Significance. The establishment of a purpose-built primary standard and associated CoP will considerably reduce the uncertainty of the absorbed dose to water determination and ensure improved accuracy and consistency in the dose delivered to patients treated with proton therapy and bring proton reference dosimetry uncertainty in line with megavoltage photon radiotherapy.

Evidences of noncovalent interactions between indole and dichloromethane under different solvent conditions

CONTEXT

Theoretical investigation of indole (IND) and its binary combination with dichloromethane (DC) in various solvents were computed to track the impact of molecular interactions on spectral characteristics. When transitioning from plain drug to complexes, different modes of IND display a substantial shift in peak location. The 3561.26 cm^-1 band shows (~15.58 cm^-1) red shift upon dilution. The geometry in various solvents was calculated using quantum chemical calculation utilizing density functional theory (DFT). The highest ALIE values are located at the indole skeleton and on complexation with DC, and the ring atoms become more electron rich. The atom-centered density matrix propagation (ADMP) molecular dynamic (MD) calculation shows that the geometries optimized through the DFT calculation match the global minima effectively. MD simulations indicate that indole is more stable in water and methanol.

METHODS

DFT studies have been employed to study the interaction between indole and dichloromethane. CAM-B3LYP/6-311++G(d)(6D,7F) level of theory was employed using Gaussian 16 W suite. Quantum topological descriptors were discussed using quantum theory of atoms in molecules (QTAIM) with the help of Multiwfn software. Reduced density gradient (RDG) plot describes the nature of the interaction, while average local ionization energy (ALIE) explained the variation in local ionization energy of the molecular surface before and after complexation.

Study of Non-Covalent Interactions Present in the Tapinarof-Ethanol System with Special Emphasis on Hydrogen-Bonding Interactions

In this study, the effect of non-covalent interaction in the tapinarof-EtOH systems is evaluated, particularly the hydrogen-bonding interaction using density functional theory in a gas phase. From the optimization results and the binding energy calculated thereafter, it is concluded that interaction in the employed system occurs between the O-H groups on tapinarof and the oxygen atom of EtOH molecules existing in the vicinity of the O-H group. These interactions were concluded to be those of the weak hydrogen bonds by carrying out the reduced gradient approach and QTAIM analysis, which are basically electron-density-based topological analyses. The charge localization between the donor-acceptor moieties was analyzed using the NBO analysis. Using the LED analysis, the binding energy between the tapinarof and EtOH was partitioned into different energy terms centered on a domain-based local pair natural orbital coupled cluster method. Thus, the electronic environment of the tapinarof-EtOH systems is evaluated.

Biodistribution of naturally occurring radionuclides and radiocesium in wild European perch (Perca fluviatilis)

Wild European perch (Perca fluviatilis) is one of the most important freshwater fish species, in Sweden, due to its widespread and his value for recreational fishing. Little it is known regarding the biodistribution of naturally occurring radionuclides such as ²³⁸U, ²³⁴U, ²²⁶Ra, ²¹⁰Po in perch. Therefore, in this study, perches from five lakes located in different counties in Sweden were collected to investigate the biodistribution of ²³⁸U, ²³⁴U, ²²⁶Ra, ²¹⁰Po and ¹³⁷Cs in organs and tissues of perch as well as their radiological impact. The results showed that uranium radionuclides ranged between 0.1 and 6 Bq/kg with an average value of 1.1 ± 1.5 Bq/kg. ²²⁶Ra varied from 0.4 to 8 Bq/kg with a mean concentration of 1.7 ± 1.9 Bq/kg. The ranged of ²¹⁰Po was 0.5 - 250 Bq/kg, with an average value of 24 ± 52 Bq/kg. On the other hand, the highest activity concentration of ¹³⁷Cs, 151 ± 1 Bq/kg, was detected in muscle samples of perch from Redsjösjön lake. For uranium radionuclides and ²²⁶Ra uptake from water is the main source whereas for ²¹⁰Po and ¹³⁷Cs the uptake is controlled by the perch diet. Regarding naturally occurring radionuclides, the perch tended to accumulated uranium radionuclides in fins, gills, and skin; ²²⁶Ra in bones, fins and skin and ²¹⁰Po in the organs linked to digestive system. Finally, in case of consumption, it is advised the consumption of skinned fillets of perch due to the higher bioaccumulation of the radionuclides investigated in the skin and scales.

Experimental determination of concentration factors of Mn, Zn and I in the phytoplankton species Phaeodactylum Tricornutum

Anthropogenic radionuclides released into the environment cause a radiation dose to wildlife and humans which must be quantified, both to assess the effect of normal releases, and to predict the consequences of a larger, unplanned release. To estimate the spread of the radioactive elements, the ecosystem around release points is modelled, and element uptake is usually quantified by concentration factors (CF), which relates the concentration of an element in an organism to the concentration of the same element in a medium under equilibrium conditions. In this work, we experimentally determine some phytoplankton CF that are needed for improved modelling of the marine ecosystems around nuclear facilities and release points. CFs that require better determination have been identified through literature search. Sensitivity studies, using the currently used ecosystem modelling software PREDO, show that for most studied groups, the dose committed by the respective radionuclides is almost proportional to the corresponding phytoplankton CFs. In the present work, CFs are determined through laboratory experiments with cultured phytoplankton and radionuclides of the concerned elements, assessing the element uptake by the phytoplankton through detection of the emitted radiation. The three CF assessed in this work were those for manganese, zinc and iodine in phytoplankton. Conservative estimates of these CF based on the present data are 40 000 L/kg for manganese, 50 000 L/kg for zinc and 180 L/kg for iodine with the phytoplankton masses referring to their dry weight.

First Constraints from DAMIC-M on Sub-GeV Dark-Matter Particles Interacting with Electrons

We report constraints on sub-GeV dark matter particles interacting with electrons from the first underground operation of DAMIC-M detectors. The search is performed with an integrated exposure of 85.23 g days, and exploits the subelectron charge resolution and low level of dark current of DAMIC-M charge-coupled devices (CCDs). Dark-matter-induced ionization signals above the detector dark current are searched for in CCD pixels with charge up to 7e^{-}. With this dataset we place limits on dark matter particles of mass between 0.53 and 1000  MeV/c^{2}, excluding unexplored regions of parameter space in the mass ranges [1.6,1000]  MeV/c^{2} and [1.5,15.1]  MeV/c^{2} for ultralight and heavy mediator interactions, respectively.

Synthesis and Biological Evaluation of Octahydroquinazolinones as Phospholipase A2, and Protease Inhibitors: Experimental and Theoretical Exploration

Phospholipase A2 (PLA2) promotes inflammation via lipid mediators and releases arachidonic acid (AA), and these enzymes have been found to be elevated in a variety of diseases, including rheumatoid arthritis, sepsis, and atherosclerosis. The mobilization of AA by PLA2 and subsequent synthesis of prostaglandins are regarded as critical events in inflammation. Inflammatory processes may be treated with drugs that inhibit PLA2, thereby blocking the COX and LOX pathways in the AA cascade. To address this issue, we report herein an efficient method for the synthesis of a series of octahydroquinazolinone compounds (4a-h) in the presence of the catalyst Pd-HPW/SiO₂ and their phospholipase A2, as well as protease inhibitory activities. Among eight compounds, two of them exhibited overwhelming results against PLA2 and protease. By using FT-IR, Raman, NMR, and mass spectroscopy, two novel compounds were thoroughly studied. After carefully examining the SAR of the investigated compounds against these enzymes, it was found that compounds (4a, 4b) containing both electron-donating and electron-withdrawing groups on the phenyl ring exhibited higher activity than compounds with only one of these groups. DFT studies were employed to study the electronic nature and reactivity properties of the molecules by optimizing at the BLYP/cc-pVDZ. Natural bond orbitals helped to study the various electron delocalizations in the molecules, and the frontier molecular orbitals helped with the reactivity and stability parameters. The nature and extent of the expressed biological activity of the molecule were studied using molecular docking with human non-pancreatic secretory phospholipase A2 (hnps-PLA2) (PDB ID: 1DB4) and protease K (PDB ID: 2PWB). The drug-ability of the molecule has been tested using ADMET, and pharmacodynamics data have been extracted. Both the compounds qualify for ADME properties and follow Lipinski's rule of five.

Computational studies of the CuAAC reaction mechanism with diimine and phosphorus ligands for the synthesis of 1,4-disubstituted 1,2,3-triazoles

The Cu(i)-catalyzed azide-alkyne cycloaddition (CuAAC) reactions with diimine and phosphorus ligands have been studied using DFT calculations in order to understand the effect of the nature of the ligands on the catalytic cycle for the formation of the 1,4-regioisomer.

Use of the Arctic Sun™ 5000 targeted temperature management system to achieve rewarming during a prolonged hypothermic cardiorespiratory arrest

Cardiorespiratory arrest due to severe hypothermia may require prolonged cardiopulmonary resuscitation whilst the patient is rewarmed. There are reported cases of successful resuscitation with good neurological outcomes after prolonged arrests and resuscitation up to 9 h. However, in the majority of these cases, extracorporeal life support was used to maintain perfusion and rewarm the patient. Here, we report a case of successful cardiopulmonary resuscitation lasting 6.5 h, following cardiac arrest secondary to severe hypothermia, with rewarming using an Arctic Sun™ 5000. The Arctic Sun 5000 is a targeted temperature management device which is conventionally used to prevent hyperthermia post-cardiac arrest. In this report, we discuss the reasons why the device was used in this case and the effects of severe hypothermia on cardiac arrest management. We believe that this is the longest reported successful cardiopulmonary resuscitation in a severely hypothermic patient without the use of extracorporeal life support.

Vaccination policy strategies before and during the COVID-19 pandemic: an overview

Background

The debate on vaccination strategies has been periodically involving researchers, policymakers, and also the population. Interest waves have occurred both after a revival of childhood infectious diseases in 2016-2017, due to low vaccine coverages, and during the recent Coronavirus outbreak. This study aimed at overviewing vaccination strategies (and corresponding vaccine coverages) for childhood vaccinations and SARS-CoV-2.

Methods

Measles was chosen as a childhood vaccination indicator. Policy data were retrieved from health institutions (either European or national/regional) and, for COVID-19, also from press agencies and newspaper websites. Vaccine coverage data were retrieved from the World Bank, World Health Organisation, and UNICEF databases (for childhood vaccines), and from the “Our World in Data” platform for SARS-CoV-2. A qualitative comparison was performed between the two contexts.

Results

Unlike childhood vaccinations, few countries (and only Austria in Europe) imposed generalised COVID-19 mandates, most countries preferring targeted mandates for higher-risk groups. Many countries confirmed their traditional voluntary vaccination approach also for COVID-19, while countries historically relying on compulsory vaccination strategies, such as Slovenia and Hungary, surprisingly opted for voluntary SARS-CoV-2 vaccination, with unsatisfactory results. However, no tangible crude association was generally found between vaccination policies and achieved coverages, although factors such as cultural background, education, and religion appeared to influence the impact of vaccination policies.

Conclusions

The COVID-19 experience has enriched pre-existent vaccination strategy debates by adding interesting elements concerning attitudes toward vaccines in a novel context. Reading the available results in the frame of vaccine hesitancy determinants can help to understand the relationship between policies and actual coverages.

Key messages

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

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

O102 We know about left gastric artery embolisation and will embio provide the next solution to treat obesity?

Introduction

Left gastric artery embolisation (LGAE) is a minimally invasive procedure which has shown promising results for weight loss in recent studies and could play a key role as a treatment option in-between our current tier-3 and tier-4 services. Imperial College NHS Trust will sponsor the EMBIO trial, the first multi-centre double blinded randomised controlled trial comparing LGAE vs Placebo procedure to evaluate its efficacy on weight loss and obesity related comorbidities over a 12 month follow up period. Here, we perform a systematic review of the existing literature.

Methods

9 studies were reviewed. Studies which investigated weight loss as a % +- Ghrelin % change at 3,6 and 12 months were included as these pre-defined time points correlate with the EMBIO protocol. 6 studies met our inclusion criteria, 5 single arm studies and 1 single blinded RCT.

Results

N=62 patients were included in our analysis. Mean weight loss reported was 8.5%, 8.8% and 10% at 3, 6 and 12 months respectively post LGAE. Ghrelin levels reduced by 36%, 16.2% and 16.5% at 3, 6 and 12 months respectively post LGAE. To date, the only reported adverse events recorded include superficial gastric erosions healed on endoscopy by day 90 and one case of subclinical pancreatitis.

Conclusion

LGAE potentially offers a day case procedure under local anaesthesia and sedation to treat obesity and its metabolic complications. The EMBIO trial will provide level 1 evidence to confirm if LGAE is a viable intervention for obesity and evaluate its safety profile.

Take-home message

Left gastric artery embolisation could be the perfect solution to treat obesity in between existing tier-3 and tier-4 treatments.

Adsorption of a thione derivative on carbon, AlN, and BN nanotubes: a detailed DFT and MD investigation

The performance of nanotubes (NT) of carbon (CC), aluminium-nitrogen (AlN), and boron-nitrogen (BN) as a sensor and nanocarrier for mercaptopurine (MCP) was investigated by means of a theoretical approach. The calculated negative values of adsorption energy showed the interaction and adsorption of MCP. Highest-occupied molecular orbital (HOMO) and lowest-unoccupied molecular orbital (LUMO) distributions were only found on the NT counter portion of the drug-nanotube not on MCP for AlN-NT and BN-NT while HOMO is over MCP and LUMO is over NT for CC-NT. The polarizability of MCP-NTs is greater than that of MCP. Raman wavenumbers of MCP are enhanced in NTs, and hence, NTs can act as a sensor for the detection of MCP. Solvent dependency on adsorption behaviour is also presented in the manuscript, where we found that the AlN nanotube showed exceptionally high free energy of adsorption over other nanotubes in all solvent mediums. Solvation-free energies were also reported. Noncovalent interaction scattered plot also showed significant intermolecular interaction between AlN nanotubes and the mercaptopurine when compared to other nanotubes under study. To find the antiviral activity of MCP and MCP-NTs against antiviral activities, docking and molecular dynamics simulations were performed with 1HMP PDB. Recovery times show that MCP desorption occurs quickly. The MD simulations and docking results show that BN and CC-NTs with MCP show good activity as drug carriers.

POS1329 SECONDARY HAEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS: A SINGLE-CENTRE EXPERIENCE

Background

Haemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome characterised by fever, organomegaly, cytopaenias, activated macrophages in haematopoietic organs and elevated ferritin. Primary HLH is caused by inherited defects in cytolytic pathway proteins and manifests in infancy[1]. Secondary HLH (sHLH) develops in individuals with a genetic susceptibility to hyperinflammation triggered by strongly immunogenic stimulus such as autoimmune conditions, haematological malignancy, organ transplantation or infection[2].

We present a cohort of patients with sHLH and detail their characteristics.

Objectives

To evaluate the characteristics and aetiology of sHLH patients at our Centre.

Methods

A single-centre retrospective observational study of all cases of sHLH between January 2018 and July 2021. Patients were identified from referrals and included if there was a diagnosis of HLH made by a rheumatologist with an H-score of 169 or greater. P-values were calculated using the Mann-Whitney test, unpaired t-test or Fisher exact as appropriate.

Results

30 patients (10 female) with sHLH were identified with a median age of 46, a mean H-score of 238 (range 186-317). 15 (50%) had pre-existing immunosuppression, which did not influence mortality (p=0.26). The following primary drivers were identified: lymphoma (n=8), non-HIV viral infections (n=9), first presentation of HIV/AIDS with opportunistic infections (n=4), Adult-onset Still’s disease (n=4), miliary tuberculosis (n=1), M. falciparum infection (n=1), meningococcal meningitis (n=1), checkpoint inhibitor therapy-related (n=1), and no diagnosis (n=1) - Table 1.

Table 1.

§ = Mann Whitney U test, τ = unpaired t-test, φ = Fisher exact

Total (n=30)Survived (n=18)Died (n=12)p-valueDemographicsMale2010100.78§Female1082Mean age4341470.348§Median H-score2402302540.059 τFerritin (ng/ml)4027734690484040.0949Trilineage cytopenia, n (%)9 (33%)5 (31%)4 (36%)0.28§Subgroup (not mutually exclusive)1 yr survivalLymphoma81712.5% (p=0.0025 φ)HIV/AIDS440100%AOSD440100%Transplant recipient41325%Other viral infection95444%  HSV330100%  CMV110100%  EBV1010%  Yellow fever2020%  Influenza A110100%Tuberculosis32166% with HIV220100%

Non-HIV viral infections were the most common cause overall. 6 of 9 were caused by Herpes virus family and all were primary infections. Two followed yellow fever viraemia following live vaccination and both patients died.

Mortality varied with aetiology. All four patients with AOSD survived, while 7 of 8 with lymphoma died, as per previous reports3. There was a strong association between lymphoma and mortality vs non-lymphoma sHLH (p=0.0025). Four patients post-solid organ transplantation were identified (three liver, one kidney), three with post-transplant lymphoproliferative disorder and one with CMV viraemia (50% mortality).

There was no significant difference between age, ferritin or H-score between surviving and deceased patients (Figure 1), but H-score trended higher in the deceased (p=0.059). Number of treatments given for HLH was higher in the deceased group vs survival (mean 3.41 deceased, mean 2.44 in survived). Anakinra was used in all 30 patients as treatment, including as monotherapy in one patient with HSV viraemia who survived.

Figure 1.

Conclusion

Ferritin, H-score at diagnosis or age do not appear to correlate with mortality in sHLH. Lymphoma is associated with a significantly worse outcome. Poor response to treatment and increasing numbers of treatment options is associated with increased mortality. Causes are varied and often co-exist.

References

[1]Jordan MB et al. An animal model of hemophagocytic lymphohistiocytosis (HLH): CD8+ T cells and interferon gamma are essential for the disorder. Blood. 2004.

[2]Carter SJ et al. Macrophage activation syndrome in adults: recent advances in pathophysiology, diagnosis and treatments. Rheumatology. 2019.

[3]Parikh SA et al. Prognostic Factors and Outcomes of Adults with Hemophagocytic Lymphohistiocytosis. Mayo Clin Proc. 2014.

Disclosure of Interests

None declared