Addressing forensic science challenges with nuclear analytical techniques - A review

We review the application of Nuclear Analytical Techniques (NATs) to forensic problems for the first time. NATs include neutron activation analysis (NAA), carried out in nuclear reactors for elemental analysis; accelerator-based techniques, mainly Ion Beam Analysis (IBA) for elemental and molecular analysis; and Accelerator Mass Spectrometry (AMS) for dating of traces of forensic interest by "radiocarbon dating" and other related methods. Applications include analysis of drugs of abuse, food fraud, counterfeit medicine, gunshot residue, glass fragments, forgery of art objects and documents, and human material. In some applications only the NATs are able to provide relevant information for forensic purposes. This review not only includes a wide collection of forensic applications, but also illustrates the wide availability worldwide of NATs, opening up opportunities for an increased use of NATs in routine forensic casework.

Prevalence and factors associated with methicillin-resistant Staphylococcus aureus colonization on admission to geriatric care units: impact on screening practices

OBJECTIVES

Universal screening for methicillin-resistant Staphylococcus aureus (MRSA) entails additional costs, and there is no consensus for targeted screening for high-risk units. The aims of this study were to determine the prevalence of MRSA in geriatric care units, and to identify the factors associated with MRSA colonization on admission.

METHODS

This retrospective case-control study (1:1) in the geriatric care unit of six Belgian hospitals covered the period from 1st January 2021 to 31st December 2022. Cases were patients with a positive MRSA screening result within 48 h of admission to the geriatric care unit, and controls were patients with a negative screening result.

RESULTS

In total, 556 patients were included in this study (278 in each group). Prevalence per 100 admissions for the total sample was 2.3 [95% confidence interval (CI) 2.2-2.6]. Significant multi-variate factors associated with MRSA carriage on admission were: history of MRSA, nursing home origin, and chronic skin lesions. Applying these three factors would give an area under the receiver operating characteristic (ROC) curve of 0.73 (95% CI 0.71-0.77), and would allow screening to be carried out in only 55.4% of cases (95% CI 51.2-59.6%).

CONCLUSIONS

Using these factors as screening criteria in geriatric care units could significantly reduce the number of patients screened for MRSA, while maintaining satisfactory sensitivity and specificity.

Marine transmissible cancer navigates urbanized waters, threatening spillover

Inter-individual transmission of cancer cells represents a unique form of microparasites increasingly reported in marine bivalves. In this study, we sought to understand the ecology of the propagation of Mytilus trossulus Bivalve Transmissible Neoplasia 2 (MtrBTN2), a transmissible cancer affecting four Mytilus mussel species worldwide. We investigated the prevalence of MtrBTN2 in the mosaic hybrid zone of M. edulis and M. galloprovincialis along the French Atlantic coast, sampling contrasting natural and anthropogenic habitats. We observed a similar prevalence in both species, probably due to the spatial proximity of the two species in this region. Our results showed that ports had higher prevalence of MtrBTN2, with a possible hotspot observed at a shuttle landing dock. No cancer was found in natural beds except for two sites close to the hotspot, suggesting spillover. Ports may provide favourable conditions for the transmission of MtrBTN2, such as high mussel density, stressful conditions, sheltered and confined shores or buffered temperatures. Ships may also spread the disease through biofouling. Our results suggest ports may serve as epidemiological hubs, with maritime routes providing artificial gateways for MtrBTN2 propagation. This highlights the importance of preventing biofouling on docks and ship hulls to limit the spread of marine pathogens hosted by fouling species.

High species richness in the lichen genus Peltigera (Ascomycota, Lecanoromycetes): 34 species in the dolichorhizoid and scabrosoid clades of section Polydactylon, including 24 new to science

Applying molecular methods to fungi establishing lichenized associations with green algae or cyanobacteria has repeatedly revealed the existence of numerous phylogenetic taxa overlooked by classical taxonomic approaches. Here, we report taxonomical conclusions based on multiple species delimitation and validation analyses performed on an eight-locus dataset that includes world-wide representatives of the dolichorhizoid and scabrosoid clades in section Polydactylon of the genus Peltigera. Following the recommendations resulting from a consensus species delimitation approach and additional species validation analysis (BPP) performed in this study, we present a total of 25 species in the dolichorhizoid clade and nine in the scabrosoid clade, including respectively 18 and six species that are new to science and formally described. Additionally, one combination and three varieties (including two new to science) are proposed in the dolichorhizoid clade. The following 24 new species are described: P. appalachiensis, P. asiatica, P. borealis, P. borinquensis, P. chabanenkoae, P. clathrata, P. elixii, P. esslingeri, P. flabellae, P. gallowayi, P. hawaiiensis, P. holtanhartwigii, P. itatiaiae, P. hokkaidoensis, P. kukwae, P. massonii, P. mikado, P. nigriventris, P. orientalis, P. rangiferina, P. sipmanii, P. stanleyensis, P. vitikainenii and P. willdenowii; the following new varieties are introduced: P. kukwae var. phyllidiata and P. truculenta var. austroscabrosa; and the following new combination is introduced: P. hymenina var. dissecta. Each species from the dolichorhizoid and scabrosoid clades is morphologically and chemically described, illustrated, and characterised with ITS sequences. Identification keys are provided for the main biogeographic regions where species from the two clades occur. Morphological and chemical characters that are commonly used for species identification in the genus Peltigera cannot be applied to unambiguously recognise most molecularly circumscribed species, due to high variation of thalli formed by individuals within a fungal species, including the presence of distinct morphs in some cases, or low interspecific variation in others. The four commonly recognised morphospecies: P. dolichorhiza, P. neopolydactyla, P. pulverulenta and P. scabrosa in the dolichorhizoid and scabrosoid clades represent species complexes spread across multiple and often phylogenetically distantly related lineages. Geographic origin of specimens is often helpful for species recognition; however, ITS sequences are frequently required for a reliable identification. Citation: Magain N, Miadlikowska J, Goffinet B, et al. 2023. High species richness in the lichen genus Peltigera (Ascomycota, Lecanoromycetes): 34 species in the dolichorhizoid and scabrosoid clades of section Polydactylon, including 24 new to science. Persoonia 51: 1-88. doi: 10.3767/persoonia.2023.51.01.

Structures and stabilities of PAH clusters solvated by water aggregates: The case of the pyrene dimer

Although clusters made of polycyclic aromatic hydrocarbon and water monomers are relevant objects in both atmospheric and astrophysical science, little is known about their energetic and structural properties. In this work, we perform global explorations of the potential energy landscapes of neutral clusters made of two pyrene units and one to ten water molecules using a density-functional-based tight-binding (DFTB) potential followed by local optimizations at the density-functional theory level. We discuss the binding energies with respect to various dissociation channels. It shows that cohesion energies of the water clusters interacting with a pyrene dimer are larger than those of the pure water clusters, reaching for the largest clusters an asymptotic limit similar to that of pure water clusters and that, although the hexamer and octamer can be considered magic numbers for isolated water clusters, it is not the case anymore when they are interacting with a pyrene dimer. Ionization potentials are also computed by making use of the configuration interaction extension of DFTB, and we show that in cations, the charge is mostly carried by the pyrene molecules.

Acute physiological effects following Bacillus subtilis DE111 oral ingestion - a randomised, double blinded, placebo-controlled study

Previous studies using ileostomy samples from study participants demonstrated that the spore-forming probiotic Bacillus subtilis DE111® can germinate in the small intestine as early as 4 hours after ingestion. Metabolomics, proteomics and sequencing technologies, enabled further analysis of these samples for the presence of hypoglycaemic, hypolipidemic, antioxidant, anti-inflammatory and antihypertensive molecules. In the DE111 treatment group, the polyphenols trigonelline and 2,5-dihydroxybenzoic acid, orotic acid, the non-essential amino acid cystine and the lipokine 12,13-diHome were increased. DE111 also reduced acetylcholine levels in the ileostomy samples, and increased the expression of leucocyte recruiting proteins, antimicrobial peptides and intestinal alkaline phosphatases of the brush border in the small intestine. The combination of B. subtilis DE111 and the diet administered during the study increased the expression of the proteins phosphodiesterase ENPP7, ceramidase ASAH2 and the adipokine Zn-alpha-2-glycoprotein that are involved in fatty acid and lipid metabolism. Acute B. subtilis DE111 ingestion had limited detectable effect on the microbiome, with the main change being its increased presence. These findings support previous data suggesting a beneficial role of DE111 in digestion, metabolism, and immune health that appears to begin within hours of consumption.

Role of antiseptics in the prevention and treatment of infections in nursing homes

Inadequate infection control, wound care, and oral hygiene protocols in nursing homes pose challenges to residents' quality of life. Based on the outcomes from a focus group meeting and a literature search, this narrative review evaluates the current and potential roles of antiseptics within nursing home infection management procedures. We examine contemporary strategies and concerns within the management of meticillin-resistant Staphylococcus aureus (MRSA; including decolonization regimes), chronic wound care, and oral hygiene, and review the available data for the use of antiseptics, with a focus on povidone-iodine. Compared with chlorhexidine, polyhexanide, and silver, povidone-iodine has a broader spectrum of antimicrobial activity, with rapid and potent activity against MRSA and other microbes found in chronic wounds, including biofilms. As no reports of bacterial resistance or cross-resistance following exposure to povidone-iodine exist, it may be preferable for MRSA decolonization compared with mupirocin and chlorhexidine, which can lead to resistant MRSA strains. Povidone-iodine oral products have greater efficacy against oral pathogens compared with other antiseptics such as chlorhexidine mouthwash, highlighting the clinical benefit of povidone-iodine in oral care. Additionally, povidone-iodine-based products, including mouthwash, have demonstrated rapid in-vitro virucidal activity against SARS-CoV-2 and may help reduce its transmission if incorporated into nursing home coronavirus 2019 control protocols. Importantly, povidone-iodine activity is not adversely affected by organic material, such as that found in chronic wounds and the oral cavity. Povidone-iodine is a promising antiseptic agent for the management of infections in the nursing home setting, including MRSA decolonization procedures, chronic wound management, and oral care.

The role of routine SARS-CoV-2 screening of healthcare-workers in acute care hospitals in 2020: a systematic review and meta-analysis

Background

Healthcare workers (HCW) are at increased risk of infection with SARS-CoV-2. Vulnerable patient populations in particular must be protected, and clinics should not become transmission hotspots to avoid delaying medical treatments independent of COVID. Because asymptomatic transmission has been described, routine screening of asymptomatic HCW would potentially be able to interrupt chains of infection through early detection.

Methods

A systematic search was conducted in the Cochrane COVID-19 Study Register, Web of Science and WHO COVID‐19 Global literature on coronavirus with regard to non-incident related testing of healthcare workers using polymerase chain reaction on May 4th 2021. Studies since January 2020 were included. An assessment of risk of bias and representativeness was performed.

Results

The search identified 39 studies with heterogeneous designs. Data collection of the included studies took place from January to August 2020. The studies were conducted worldwide and the sample size of the included HCW ranged from 70 to 9449 participants. In total, 1000 of 51,700 (1.9%) asymptomatic HCW were tested positive for SARS-CoV-2 using PCR testing. The proportion of positive test results ranged between 0 and 14.3%. No study reported on HCW-screening related reductions in infected person-days.

Discussion and conclusions

The heterogeneous proportions might be explained by different regional incidences, lock-downs, and pre-analytical pitfalls that reduce the sensitivity of the nasopharyngeal swab. The very high prevalence in some studies indicates that screening HCW for SARS-CoV-2 may be important particularly in geographical regions and pandemic periods with a high-incidence. With low numbers and an increasing rate of vaccinated HCW, a strict cost–benefit consideration must be made, especially in times of low incidences. Since we found no studies that reported on HCW-screening related reductions in infected person-days, re-evaluation should be done when these are available.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07554-5.

P-657 Administration of an extra Gonadotropin dose on trigger day in patients undergoing elective egg freezing

Study question

Does an extra Gonadotropin (GT) dose on trigger day during a gonadotropin-releasing hormone (GnRH) antagonist cycle for oocyte cryopreservation result in improved cycle outcomes?

Summary answer

An extra GT dose on trigger day in patients undergoing elective egg freezing is not associated with increased oocyte yield.

What is known already

The most common controlled ovarian hyperstimulation (COHS) protocol used in elective oocyte cryopreservation cycles is a GnRH antagonist protocol with a GnRH agonist trigger. There is no consensus about the timing of the final gonadotropin dose administration. Some physicians add an extra GT dose during the ovulation trigger day and others advise to receive the last GT dose the day before. The yield of this extra GT dose was not previously evaluated.

Study design, size, duration

A retrospective cohort study, consisting of cycles of elective oocyte cryopreservation at Hadassah Medical Center from 1.2017 through 5.2021. Patients were divided into 2 groups- women who received their last GT dose a day before the GnRH agonist trigger, and women who received the last GT on the trigger day. Background and gynecologic characteristics, as well as COHS cycle parameters, were compared. The primary outcome was the average number of mature oocytes in each group.

Participants/materials, setting, methods

Women 30-41 years who were admitted for elective oocyte cryopreservation. Women who were referred due to medical reasons or cycles with a protocol other than GnRH antagonist were excluded. Ovarian stimulation with GT began on the 3rd day of the cycle, and five days later, a GnRH antagonist was added. When more than two mature follicles were demonstrated, a GnRH agonist trigger was administrated and approximately 36 hours later, the oocyte aspiration procedure was performed

Main results and the role of chance

During the study period, 448 elective egg freezing cycles were performed, 151 cycles with an extra dose on the trigger day and 297 cycles without an extra GT dose. The groups did not differ in their background characteristics, age, BMI, GT used, and the number of induction days. However, the extra GT group had significantly higher day 3 follicular stimulating hormone (FSH), lower anti-Mullerian hormone (AMH), and lower maximal Estradiol (E2) levels. The extra GT dose group had a significantly lower mean number of mature oocytes (11.1±7.1 vs. 6.4±4.5, p < 0.001).

To adjust for the maximal E2 parameter, that differed between the groups, an additional analysis was performed, dividing the two groups into subgroups of cycles with maximal E2 above and below 10,000 pmol\l. Interestingly, even in cycles with maximal E2 above 10,000 pmol\l, the extra dose group had poorer results (10.3±4.3 vs. 12.7±7.2, p < 0.001). This difference was also noted in cycles with E2 below 10,000 pmol\l (5.4±4.0 vs 8.7±6.1 mature oocytes, p = 0.011). Additionally, a multiple regression model for the prediction of several oocytes retrieved showed that the extra GT dose parameter was not associated with increased oocytes number.

Limitations, reasons for caution

The retrospective design of this study and the differences in cycle characteristics between patients that did or did not receive an extra GT dose on trigger day make it prone to selection bias.

Wider implications of the findings

Our study shows that administration of an extra GT dose on trigger day in oocyte cryopreservation cycles does not yields more mature oocytes. However, wider prospective studies are needed to thoroughly investigate the implications of this treatment’s effect on cycle outcomes.

Trial registration number

Not applicable

POS1372 THE 2021 EULAR AND ACR POINTS TO CONSIDER FOR DIAGNOSIS, MANAGEMENT AND MONITORING OF THE IL 1 MEDIATED AUTOINFLAMMATORY DISEASES: CAPS, TRAPS, MKD, AND DIRA

Background

The Interleukin-1 (IL-1) mediated systemic autoinflammatory diseases (SAIDs), including the cryopyrin-associated periodic syndromes (CAPS), tumor necrosis factor receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), and deficiency of the IL-1 receptor antagonist (DIRA) belong to a group of rare immunodysregulatory diseases that primarily present in early childhood with variable multiorgan involvement. When untreated, patients with severe clinical phenotypes have a poor prognosis, and diagnosis and management of these patients can be challenging. However, recently-approved treatments targeting the pro-inflammatory cytokine IL-1 have been life-changing and have significantly improved patient outcomes.

Objectives

We aimed to establish evidence-based recommendations on diagnosis, treatment, and monitoring to standardize the management of these patients.

Methods

A multinational, multidisciplinary task force consisting of physician experts including rheumatologists, patients or caregivers, and allied health care professionals was established. Evidence synthesis including systematic literature review and expert consensus (Delphi) via surveys were conducted. Consensus methodology was utilized to formulate and vote on statements to guide optimal patient care.

Results

The task force devised five overarching principles, 14 statements related to diagnosis, 10 on therapy, and 9 focused on long-term monitoring that were evidence and/or consensus-based for patients with IL-1 mediated diseases. An outline was developed for disease-specific monitoring of inflammation-induced organ damage progression and reported therapies of CAPS, TRAPS, MKD, and DIRA.

Conclusion

The 2021 EULAR/ACR points to consider provide state-of-the-art knowledge based on published data and expert opinion to guide diagnostic evaluation, treatment, and monitoring of patients with CAPS, TRAPS, MKD and DIRA, and inform the various stakeholders about optimized patient care to improve disease outcomes.

References

[1]Masters SL, Simon A, Aksentijevich I, et al. Horror autoinflammaticus: the molecular pathophysiology of autoinflammatory disease (*). Annu Rev Immunol 2009;27:621-68.

Disclosure of Interests

micol romano: None declared, Zehra Serap Arici: None declared, David Piskin: None declared, Sara Alehashemi: None declared, Daniel Aletaha Speakers bureau: Lilly, Merck, Pfizer, Roche, Sandoz, Consultant of: Abbvie, Amgen, Lilly, Merck, Novartis, Pfizer, Roche, Sandoz, Grant/research support from: Abbvie, Amgen, Lilly, Novartis, Roche, SoBi, Sanofi, Karyl Barron: None declared, Susa Benseler: None declared, Roberta Berard Consultant of: Sandoz and Roche, Lori Broderick Grant/research support from: Novartis and Regeneron, Fatma Dedeoglu Consultant of: Novartis, Michelle Diebold: None declared, Karen Durrant: None declared, Polly Ferguson Consultant of: Novartis, Grant/research support from: NIH, CARRA, Inc, Dirk Foell Speakers bureau: Novartis, Peer Voice and SoBi, Consultant of: Boehringer Ingelheim, Chugai-Roche, Merck, Novartis, SoBi, Grant/research support from: Novartis and SoBi, Jonathan Hausmann Consultant of: Novartis, Biogen and Pfizer, Grant/research support from: CARRA, SoBi, Olcay Jones: None declared, Daniel Kastner: None declared, Helen J. Lachmann: None declared, Ronald Laxer Consultant of: SoBi, Novartis, Sanofi, Dorelia Rivera: None declared, Nicolino Ruperto Speakers bureau: Eli-Lilly, GSK, Pfizer SoBi and UCB, Consultant of: Ablynx, Amgen, Astrazeneca-Medimmune, Aurinia, Bayer, Bristol Myers and Squib, Cambridge Healthcare research, Celgene, Domain therapeutic, Eli-Lilly, EMD Serono, GSK, Idorsia, Janssen, Novartis, SoBi, Pfizer and UCB, Anna Simon: None declared, Marinka Twilt: None declared, Joost Frenkel: None declared, Hal Hoffman Consultant of: Novartis, Regeneron, SoBi, Aclaris, Grant/research support from: Bristol-Meyer-Squib, Jecure, Takeda and Zomagen, Adriana de Jesus: None declared, Jasmin Kuemmerle-Deschner Speakers bureau: Novartis and SoBi, Consultant of: Novartis and SoBi, Grant/research support from: Novartis and SoBi, Seza Özen Speakers bureau: Novartis and SoBi, Marco Gattorno Speakers bureau: Novartis and SoBi, Grant/research support from: Novartis, Raphaela goldbach-mansky: None declared, Erkan Demirkaya Grant/research support from: Sobi

Measurement of Low-Energy Resonance Strengths in the ^{18}O(α,γ)^{22}Ne Reaction

The ^{18}O(α,γ)^{22}Ne reaction is an essential part of a reaction chain that produces the ^{22}Ne(α,n)^{25}Mg neutron source for both the weak and main components of the slow neutron-capture process. At temperatures of stellar helium burning, the astrophysically relevant resonances in the ^{18}O(α,γ)^{22}Ne reaction that dominate the reaction rate occur at α particle energies E_{lab} of 472 and 569 keV. However, previous experiments have shown the strengths of these two resonances to be very weak, and only upper limits or partial resonance strengths could be obtained. This Letter reports the first direct measurement of the total resonance strength for the 472- and 569-keV resonances, 0.26±0.05 and 0.63±0.30  μeV, respectively. New resonance strengths for the resonances at α particle energies of 662.1, 749.9, and 767.6 keV are also provided. These results were achieved in an experiment optimized for background suppression and detection efficiency. The experiment was performed at the Sanford Underground Research Facility, in the 4850-foot underground cavity dedicated to the Compact Accelerator System for Performing Astrophysical Research. The experimental end station used the γ-summing High EffiCiency TOtal absorption spectrometeR. Compared to previous works, the results decrease the stellar reaction rate by as much as ≈46_{-11}^{+6}% in the relevant temperature range of stellar helium burning.

Radiative relaxation in isolated large carbon clusters: Vibrational emission versus recurrent fluorescence

Recurrent fluorescence (RF) from isolated carbon clusters containing between 24 and 60 atoms is theoretically investigated as a function of internal energy, cluster size, and structural features. The vibrational relaxation kinetics and the associated IR emission spectra are determined by means of a Monte Carlo approach with vibrational density of states computed in the harmonic approximation. RF is generally found to be highly competitive with vibrational emission. The behaviors predicted for clusters of various sizes and archetypal structures indicate that the IR emission spectra are strongly influenced by RF, an energy gap law being obtained for the evolution of the RF rate constant depending on the electronic excitation state. The present results are relevant to the photophysics of the interstellar medium and could contribute to elucidating the carriers of the extended red emission bands and the continuum emission lying below the aromatic infrared bands believed to originate from mixed aromatic–aliphatic compounds.

HCV cure: an appropriate moment to reduce cannabis use in people living with HIV? (ANRS CO13 HEPAVIH data)

BACKGROUND

Thanks to direct-acting antivirals, hepatitis C virus (HCV) infection can be cured, with similar rates in HCV-infected and HIV-HCV co-infected patients. HCV cure is likely to foster behavioral changes in psychoactive substance use, which is highly prevalent in people living with HIV (PLWH). Cannabis is one substance that is very commonly used by PLWH, sometimes for therapeutic purposes. We aimed to identify correlates of cannabis use reduction following HCV cure in HIV-HCV co-infected cannabis users and to characterize persons who reduced their use.

METHODS

We used data collected on HCV-cured cannabis users in a cross-sectional survey nested in the ANRS CO13 HEPAVIH cohort of HIV-HCV co-infected patients, to perform logistic regression, with post-HCV cure cannabis reduction as the outcome, and socio-behavioral characteristics as potential correlates. We also characterized the study sample by comparing post-cure substance use behaviors between those who reduced their cannabis use and those who did not.

RESULTS

Among 140 HIV-infected cannabis users, 50 and 5 had reduced and increased their use, respectively, while 85 had not changed their use since HCV cure. Cannabis use reduction was significantly associated with tobacco use reduction, a decrease in fatigue level, paying more attention to one's dietary habits since HCV cure, and pre-HCV cure alcohol abstinence (p = 0.063 for alcohol use reduction).

CONCLUSIONS

Among PLWH using cannabis, post-HCV cure cannabis reduction was associated with tobacco use reduction, improved well-being, and adoption of healthy behaviors. The management of addictive behaviors should therefore be encouraged during HCV treatment.

Antibiotics in early life and childhood pre-B-ALL. Reasons to analyze a possible new piece in the puzzle

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer with precursor B-cell ALL (pB-ALL) accounting for ~ 85% of the cases. Childhood pB-ALL development is influenced by genetic susceptibility and host immune responses. The role of the intestinal microbiome in leukemogenesis is gaining increasing attention since Vicente-Dueñas' seminal work demonstrated that the gut microbiome is distinct in mice genetically predisposed to ALL and that the alteration of this microbiome by antibiotics is able to trigger pB-ALL in Pax5 heterozygous mice in the absence of infectious stimuli. In this review we provide an overview on novel insights on the role of the microbiome in normal and preleukemic hematopoiesis, inflammation, the effect of dysbiosis on hematopoietic stem cells and the emerging importance of the innate immune responses in the conversion from preleukemic to leukemic state in childhood ALL. Since antibiotics, which represent one of the most widely used medical interventions, alter the gut microbial composition and can cause a state of dysbiosis, this raises exciting epidemiological questions regarding the implications for antibiotic use in early life, especially in infants with a a preleukemic "first hit". Sheading light through a rigorous study on this piece of the puzzle may have broad implications for clinical practice.

Experimental Realization of the 1D Random Field Ising Model

We have measured magnetic-field-induced avalanches in a square artificial spin ice array of interacting nanomagnets. Starting from the ground state ordered configuration, we imaged the individual nanomagnet moments after each successive application of an incrementally increasing field. The statistics of the evolution of the moment configuration show good agreement with the canonical one-dimensional random field Ising model. We extract information about the microscopic structure of the arrays from our macroscopic measurements of their collective behavior, demonstrating a process that could be applied to other systems exhibiting avalanches.

P–667 Dydrogesterone supplementation in cycles triggered with lone GnRH agonist for final oocyte maturation resulted in an acceptable pregnancy rate

Study question

Can luteal oral Dydrogesterone (Duphaston) supplementation in an antagonist cycle after a lone GnRH agonist trigger rescue the luteal phase, allowing the possibility to peruse with fresh embryo transfer?

Summary answer

Functionality of the luteal phase in an antagonist cycle after a lone GnRH agonist trigger can be restored by adding Duphaston to conventional luteal support.

What is known already

Ovarian hyperstimulation syndrome (OHSS) is dramatically reduced when using antagonist cycle with lone GnRH agonist trigger before ovum pick up. This trigger induces short luteinizing hormone (LH) and follicle-stimulating hormone (FSH) peaks, associated with reduced progesterone and estrogen levels during the luteal phase. They cause an inadequate luteal phase and a significantly reduced implantation rate leading to a freeze all practice in those cycles.

Study design, size, duration

A retrospective cohort study. The study group (n = 123) included women that underwent in vitro fertilization cycles from January 2017 to May 2020. Patients received a GnRH-antagonist with a lone GnRH-agonist trigger due to imminent OSHH. The control group (n = 374) included patients under 35 years old that, during the same time period, underwent a standard antagonist protocol with a dual trigger of a GnRH-agonist and hCG.

Participants/materials, setting, methods

Study patients were given Dydrogesterone (Duphaston) in addition to micronized progesterone vaginal pills (Utrogestan) for luteal support (Duphaston group). Controls were treated conventionally with Utrogestan for luteal phase support (hCG group). The outcomes measured were pregnancy rate and OHSS events.

Main results and the role of chance

Our study was the first to evaluate the addition of Duphaston to standard luteal phase support in an antagonist cycle triggered by a lone GnRH agonist before a fresh embryo transfer. The mean number of oocytes retrieved and estradiol plasma levels were significantly higher in the Duphaston group than in the hCG group (16.9 ±7.7 vs. 10.8 ± 5.3 and 11658 ± 5280 pmol/L vs. 6048 ± 3059 pmol/L, respectively). The fertilization rate was comparable between the two groups. The mean number of embryos transferred and the clinical pregnancy rate were also comparable between groups (1.5 ± 0.6 vs 1.5 ± 0.5 and 46.3% vs 40.9%, respectively). No OHSS event was reported in either group.

Limitations, reasons for caution

This retrospective study may carry an inherent selection and information bias, derived from medical record coding. An additional limitation was the choice of physician for the lone GnRH trigger, which may have introduced a selection bias and another potential caveat was the relatively small sample size of our study groups.

Wider implications of the findings: The addition of Duphaston to conventional luteal support could effectively salvage the luteal phase without increasing the risk for OHSS. This enables, to peruse in those cycle, with fresh embryo transfer, avoiding the need to freeze all the embryos and postponed embryo transfer. Leading to lower psychological burden and costs.

Trial registration number

0632–20-HMO

Wnt1 Promotes Cementum and Alveolar Bone Growth in a Time-Dependent Manner

The WNT/β-catenin signaling pathway plays a central role in the biology of the periodontium, yet the function of specific extracellular WNT ligands remains poorly understood. By using a Wnt1-inducible transgenic mouse model targeting Col1a1-expressing alveolar osteoblasts, odontoblasts, and cementoblasts, we demonstrate that the WNT ligand WNT1 is a strong promoter of cementum and alveolar bone formation in vivo. We induced Wnt1 expression for 1, 3, or 9 wk in Wnt1Tg mice and analyzed them at the age of 6 wk and 12 wk. Micro–computed tomography (CT) analyses of the mandibles revealed a 1.8-fold increased bone volume after 1 and 3 wk of Wnt1 expression and a 3-fold increased bone volume after 9 wk of Wnt1 expression compared to controls. In addition, the alveolar ridges were higher in Wnt1Tg mice as compared to controls. Nondecalcified histology demonstrated increased acellular cementum thickness and cellular cementum volume after 3 and 9 wk of Wnt1 expression. However, 9 wk of Wnt1 expression was also associated with periodontal breakdown and ectopic mineralization of the pulp. The composition of this ectopic matrix was comparable to those of cellular cementum as demonstrated by quantitative backscattered electron imaging and immunohistochemistry for noncollagenous proteins. Our analyses of 52-wk-old mice after 9 wk of Wnt1 expression revealed that Wnt1 expression affects mandibular bone and growing incisors but not molar teeth, indicating that Wnt1 influences only growing tissues. To further investigate the effect of Wnt1 on cementoblasts, we stably transfected the cementoblast cell line (OCCM-30) with a vector expressing Wnt1-HA and performed proliferation as well as differentiation experiments. These experiments demonstrated that Wnt1 promotes proliferation but not differentiation of cementoblasts. Taken together, our findings identify, for the first time, Wnt1 as a critical regulator of alveolar bone and cementum formation, as well as provide important insights for harnessing the WNT signal pathway in regenerative dentistry.

Current practice in nutrition after allogeneic hematopoietic stem cell transplantation - Results from a survey among hematopoietic stem cell transplant centers

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is frequently associated with impaired oral intake and malnutrition, which potentially increases morbidity and mortality. Therefore, nutrition is one of the major challenges in the post-transplant period.

METHODS

To document the current clinical approach in nutritional treatment, we designed a questionnaire concerning the current practice in nutrition after alloHSCT and distributed it to German speaking centers performing alloHSCT in Germany, Austria and Switzerland between November 2018 and March 2020. Twenty-eight (39%) of 72 contacted centers completed the survey, 23 from Germany, two from Austria and three from Switzerland, representing 50% of alloHSCT activity within the participating countries in 2018.

RESULTS

All centers reported having nutritional guidelines for patients undergoing alloHSCT, whereby 86% (n = 24) provided a low-microbial diet during the neutropenic phase. The criteria to start parenteral nutrition (PN) directly after alloHSCT seemed to be consistent, 75% (n = 21) of the corresponding centers started PN if the oral nutritional intake or the bodyweight dropped below a certain limit. In the setting of intestinal graft-versus-host disease (GvHD) the current practice appeared to be more heterogenous. About 64% (n = 18) of the centers followed a special diet, added food stepwise modulated by GvHD symptoms, while only four centers regularly stopped oral intake completely (intestinal GvHD grade >1). Half of the centers (54%, n = 15) applied a lactose-free diet, followed by 43% (n = 12) which provided fat- and 18% (n = 5) gluten-free food in patients with intestinal GvHD. Supplementation of micronutrients in acute intestinal GvHD patients was performed by 54% (n = 15) of the centers, whereas vitamin D (89%, n = 25) and vitamin B₁₂ (68%, n = 19) was added regularly independently of the presence of GvHD. Only 5 (18%) participating centers ever observed a food-associated infection during hospitalization, whereas food-associated infections were reported to occur more often in the outpatient setting (64%, n = 18).

CONCLUSION

The survey documented a general consensus about the need for nutritional guidelines for patients undergoing alloHSCT. However, the nutritional treatment in clinical practice (i.e. lactose-, gluten- or fat-free in intestinal GvHD) as well as the use of food supplements was very heterogeneous. In line with current general recommendations the centers seemed to focus on safe food handling practice rather than providing a strict neutropenic diet. More high-quality data are required to provide evidence-based nutrition to patients during and after alloHSCT.

Voxyvi: A system for long-term audio and video acquisitions in neonatal intensive care units

BACKGROUND

In the European Union, 300,000 newborn babies are born prematurely every year. Their care is ensured in Neonatal Intensive Care Units (NICU) where vital signs are constantly monitored. In addition, other descriptors such as motion, facial and vocal activities have been shown to be essential to assess neurobehavioral development.

AIM

In the scope of the European project Digi-NewB, we aimed to develop and evaluate a new audio-video device designed to non-invasively acquire multi-modal data (audio, video and thermal images), while fitting the wide variety of bedding environment in NICU.

METHODS

Firstly, a multimodal system and associated software and guidelines to collect data in neonatal intensive care unit were proposed. Secondly, methods for post-evaluation of the acquisition phase were developed, including the study of clinician feedback and a qualitative analysis of the data.

RESULTS

The deployment of 19 acquisition devices in six French hospitals allowed to record more than 500 newborns of different gestational and postmenstrual ages. After the acquisition phase, clinical feedback was mostly positive. In addition, quality of more than 300 recordings was inspected and showed that 77% of the data is exploitable. In depth, the percentage of sole presence of the newborn was estimated at 62% within recordings.

CONCLUSIONS

This study demonstrates that audio-video acquisitions are feasible on a large scale in real life in NICU. The experience also allowed us to make a clear observation of the requirements and challenges that will have to be overcome in order to set up audio-video monitoring methods.

Low immune response rate of HIV-infected patients to a single injection of hepatitis A vaccine

OBJECTIVES

We aimed to evaluate the immune response of HIV-1 positive patients to a single injection of HAV vaccine in a context of vaccine shortage during the 2017 European outbreak.

METHODS

We retrospectively enrolled all HIV-1 positive patients vaccinated by a single injection of HAV vaccine Vaqta 50®. HAV serology was performed before and>30 days after the vaccine injection.

RESULTS

Among the 73 patients, HIV-1 viral load was≤50 copies/mL in 93.2% of the cases. Medians of CD4 and median ratio of T CD4/CD8 cells were 658/mm³ and 0.9, respectively. A low immune response rate (59.7%) was observed among the patients. Responders had a significantly higher CD4/CD8 cell ratio than non-responders.

CONCLUSIONS

A serologic control should be recommended in this population in the event of a single injection vaccination schedule. During routine follow-up, and prior to any untoward event, physicians should assess the vaccination coverage of HIV-infected patients.