Rescue Events Research Articles

A Randomized, Controlled Trial of Palonosetron Versus Ondansetron for Nausea, Vomiting, and Pruritus in Cesarean Delivery with Intrathecal Morphine.

Spinal anesthesia is the preferred anesthetic technique for cesarean deliveries. Postoperative nausea and vomiting (PONV) and pruritus occur in up to 80% and 83% of patients, respectively, after cesarean delivery with intrathecal opioids. Ondansetron is the recommended medication for PONV prophylaxis, but palonosetron, a second-generation 5-HT3 receptor antagonist, has a higher receptor affinity and a longer half-life. However, studies on palonosetron use in cesarean deliveries are limited. This study aimed to determine whether palonosetron was more effective than ondansetron in preventing intrathecal morphine-induced PONV and pruritus in cesarean deliveries. Parturients who underwent cesarean delivery under spinal anesthesia were randomized into 3 groups: P (palonosetron 0.075 mg), O (ondansetron 4 mg), and N (normal saline). The study drug was intravenously administered after the umbilical cord was clamped. The primary outcome measures were the 48-hour incidence of PONV and pruritus. The secondary outcome measures were the PONV and pruritus scores at the postanesthesia care unit (PACU) and ward, rescue medications, satisfaction scores, and adverse events. Ordinal data were analyzed using the Kruskal-Wallis test. Continuous and categorical data were analyzed using a 1-way analysis of variance, Kruskal-Wallis test, and Pearson's χ2 test, respectively. A value of P < .05 was considered significant. Post hoc analysis pairwise comparisons with Bonferroni correction were also performed. Overall, 300 parturients were enrolled, and 297 parturients completed the study. One patient in the P group and 2 in the O group were excluded because of conversion to general anesthesia after failed spinal anesthesia. The baseline patient characteristics were comparable between the groups. The PONV incidence rates in the P, O, and N groups were 26.3% (95% confidence interval [CI], 17.4-35.1), 34.7% (95% CI, 25.1-44.3), and 50.0% (95% CI, 40.0-59.9), respectively (P = .002). The incidence rates of pruritus in the P, O, and N groups were 69.7% (95% CI, 60.5-78.9), 76.5% (95% CI, 67.9-85.1), and 87.0% (95% CI, 80.3-93.7), respectively (P = .013). Pairwise comparisons revealed significantly lower incidences of PONV and pruritus in the P group than in the N group (P < .001 and P = .003, respectively). However, no significant differences were observed between the P and O groups or between the O and N groups. Additionally, the P group required significantly less nalbuphine rescue for pruritus than the N group (P = .004 and P = .005 for the PACU and ward, respectively). PONV rescue, satisfaction scores, and adverse events were not significantly different among the 3 groups. Palonosetron effectively prevents intrathecal morphine-induced PONV and pruritus during cesarean delivery. However, the efficacy of palonosetron is not significantly different from that of ondansetron.

12333 46 XX/XY Chimerism - Positive NIPT And Post-natal Karyotype Is It Real?

Abstract Disclosure: K.L. Del Rosario: None. N. Sheriden: None. N. Vijayakanthi: None. Introduction: Non-Invasive Prenatal Testing(NIPT) using cell free fetal DNA in plasma of pregnant women has become a routine part of prenatal care in screening for fetal aneuploidies including sex chromosome abnormalities in most regions around the world. False positive results are increasingly imposing challenges in pre-natal as well as post-natal care. Case Discussion: We report a neonate born at 32+2 weeks gestation to a 42-year-old G2 P2 mother. Pregnancy was complicated by insulin dependent maternal type 2 diabetes mellitus, maternal chronic hypertension and a positive NIPT for high-risk monosomy X. Prenatal ultrasound showed male anatomy. Interestingly on physical exam after birth, the neonate had typical male external genitalia with bilateral normal male gonads. Chromosome analysis done immediately after birth revealed the presence of two cell lines: 40 of the 50 cells (80%) had a normal female 46 XX karyotype and 10 of the 50 cells (20%) had a normal male 46 XY karyotype. These findings could be due to reabsorbed twin, Klinefelter syndrome with two trisomy rescue events, maternal cell contamination or true chimerism. In addition, fluorescence in situ hybridization (FISH) analysis for X and Y probes revealed the presence of two cell lines. The first cell line (70% of the cells) had two hybridization signals for chromosome X and the second cell line (∼25% of the cells) had one hybridization signal for chromosome X and one for chromosome Y. Postnatal ultrasound showed normal testicles with no evidence of Mullerian structures. Newborn screening was negative for congenital adrenal hyperplasia (CAH). Genetics was consulted and recommended repeat chromosomal analysis, parental testing to determine sex chromosome segregation, and follow-up with pediatric endocrinology. Repeat cytogenetic testing at 2 weeks of life resulted in a normal male chromosome complement of 46,XY. Previous abnormal cytogenetics were thought to be due to maternal cell contamination. Further endocrine labs showed LH(1.16 uIU/ml) and testosterone levels ( 87 ng/dL), appropriate levels for age indicating normal Hypothalamic Pituitary Gonadal (HPG) axis and testicular Leydig cell function. Since the family was previously counseled regarding the concept of maternal cell contamination, they expressed understanding and were happy with the update of the normal karyotype result. Conclusion: False-positive results concerning for rare chimerism on NIPT can occur and should prompt a thorough history, physical exam, ultrasound studies and repeat testing to confirm its presence. Careful consideration should be taken when counseling family about the implications of these results, especially communication about gender assignment of the infant. Presentation: 6/3/2024

Estimating the impact of sarcoptic mange epidemic on the population size of wild raccoon dogs (Nyctereutes procyonoides) from wildlife rescue data

The impact of infectious diseases on host populations is often not quantified because it is difficult to observe the host population and infectious disease dynamics. To address this problem, we developed a state-space model to simultaneously estimate host population and disease dynamics using wildlife rescue data. Using this model, we aimed to quantify the impact of sarcoptic mange on a Japanese raccoon dog population by estimating the change in their relative population size. We classified the status of rescued raccoon dogs into four categories: i) rescued due to infection with mange, ii) rescued due to traffic accidents without mange, iii) rescued due to traffic accidents with mange, and iv) rescued due to causes other than traffic accidents or mange. We modelled the observation process for each category and fitted the model to the reported number of raccoon dogs rescued between 1990 and 2010 at three wildlife rescue facilities in Kanagawa Prefecture, Japan. The mortality rate induced by mange was estimated to be 1.09 (95% credible interval (CI): 0.47–1.72) per year. The estimated prevalence of sarcoptic mange ranged between 4–80% in the study period. When a substantial prevalence of mange was observed (1995 to 2002), the host population size decreased by 91.2% (95% credible intervals: 86.3–94.7). We show that the impact of infectious disease outbreak on the wildlife population can be estimated from the time-series data of wildlife rescue events due to multiple causes. Our estimates suggest that sarcoptic mange triggered a substantial decrease in the Japanese wild raccoon dog populations.

Disease Experience of Maintenance Hemodialysis Patients: A Qualitative Study

Objective: To explore the diseases, psychological feelings, and treatment cognition of blood patients using qualitative methods. Method: Colaizzi phenomenological analysis is used to analyze data and extract themes. Results: The disease experience of maintenance hemodialysis patients can be summarized into four themes: acute medical and rescue events, early neglect of chronic diseases, economic considerations and resource scarcity, and regret and reflection on medical decisions. Conclusion: Patients face many challenges during the treatment process, and personalized services should be implemented to improve their quality of life and treatment outcomes.

Exploring the genuine psychological experiences of novice nurses at emergency resuscitation events: A qualitative interview study

PurposeAn emergency rescue situation is an inevitable challenge in medical work, requiring collaborative efforts from healthcare professionals. Due to a lack of practical experience, novice nurses may encounter difficulties in successfully managing emergency resuscitation events. This study aimed to analyse the authentic psychological experiences of novice nurses participating in emergency resuscitation events by exploring applicable coping methods and management strategies. MethodsThis study utilized a hermeneutic phenomenological qualitative research method. We employed purposive sampling to select 27 Novice nurses from West China Hospital of Sichuan University for face-to-face semistructured interviews. Data collection for this study was conducted from November 2023 to January 2024. The interviews were fully audio-recorded and transcribed verbatim. The data were coded, categorized and summarized with the help of Nvivo 20.0 software based on the interpretation of phenomenological research methods. Thematic analysis was performed to deeply analyse and extract corresponding themes. The COREQ criteria were used to guide the reporting of this study. ResultsThe authentic psychological experiences of novice nurses participating in emergency rescue events mainly include six aspects: lack of rescue knowledge reserves and related abilities, psychological and emotional changes, psychological stress after the rescue, rational arrangement of manpower, team cooperation, and postevent reflection and learning. Their authentic psychological experiences directly affect whether novice nurses can effectively respond to emergency rescue events. ConclusionsThis study suggested enhancing novice nurses' knowledge, improving their resuscitation skills, and improving their psychological well-being during resuscitation events. It advocates for organized staffing, effective teamwork, and robust support systems to empower novice nurses and improve their overall capabilities in emergencies. These findings offer valuable insights for future research in this area.

Transforming nursing assessment in acute hospitals: A cluster randomised controlled trial of an evidence-based nursing core assessment (the ENCORE trial)

BackgroundPatient safety is threatened when early signs of clinical deterioration are missed or not acted upon. This research began as a clinical-academic partnership established around a shared concern of nursing physical assessment practices on general wards and delayed recognition of clinical deterioration. The outcome was the development of a complex intervention facilitated at the ward level for proactive nursing surveillance. MethodsThe evidence-based nursing core assessment (ENCORE) trial was a pragmatic cluster-randomised controlled trial. We hypothesised that ward intervention would reduce the incidence of patient rescue events (medical emergency team activations) and serious adverse events. We randomised 29 general wards in a 1:2 allocation, across 5 Australian hospitals to intervention (n = 10) and usual care wards (n = 19). Skilled facilitation over 12 months enabled practitioner-led, ward-level practice change for proactive nursing surveillance. The primary outcome was the rate of medical emergency team activations and secondary outcomes were unplanned intensive care unit admissions, on-ward resuscitations, and unexpected deaths. Outcomes were prospectively collected for 6 months following the initial 6 months of implementation. Analysis was at the patient level using generalised linear mixed models to account for clustering by ward. ResultsWe analysed 29,385 patient admissions to intervention (n = 11,792) and control (n = 17,593) wards. Adjusted models for overall effects suggested the intervention increased the rate of medical emergency team activations (adjusted incidence rate ratio 1.314; 95 % confidence interval 0.975, 1.773), although the confidence interval was compatible with a marginal decrease to a substantial increase in rate. Confidence intervals for secondary outcomes included a range of plausible effects from benefit to harm. However, considerable heterogeneity was observed in intervention effects by patient comorbidity. Among patients with few comorbid conditions in the intervention arm there was a lower medical emergency team activation rate and decreased odds of unexpected death. Among patients with multimorbidity in the intervention arm there were higher rates of medical emergency team activation and intensive care unit admissions. ConclusionTrial outcomes have refined our assumptions about the impact of the ENCORE intervention. The intervention appears to have protective effects for patients with low complexity where frontline teams can respond locally. It also appears to have redistributed medical emergency team activations and unplanned intensive care unit admissions, mobilising higher rates of rescue for patients with multimorbidity. Trial registration numberACTRN12618001903279 (Date of registration: 22/11/2018; First participant recruited: 01/02/2019).

Loss and recovery of ecological diversity associated with evolutionary rescue in abruptly and gradually deteriorating environments.

Populations may survive environmental deterioration by evolutionary adaptation. However, such evolutionary rescue events may be associated with ecological costs, such as reduction in growth performance and loss of ecologically important genetic diversity. Those negative ecological consequences may be mitigated by additional adaptive evolution. Both the ecological costs and the opportunities for additional evolution are contingent on the severity of environmental deterioration. Here, we hypothesize that populations evolutionarily rescued from faster, relative to slow, environmental deterioration suffer more severe long-term fitness decline and diversity loss. An experiment with the model adaptive radiation of bacterium Pseudomonas fluorescens exposed to abruptly or gradually increased antibiotic stress supported our hypothesis. The effect of additional adaptive evolution in recovering population size and ecological diversity was far from perfect. Cautions are therefore needed in predicting the role of rapid evolution for mitigating the impacts of environmental changes, in particular very fast environmental deterioration. We also found that bacterial populations rescued from gradually increased antibiotic stress evolved higher levels of antibiotic resistance, lending more support to aggressive chemotherapy in pathogen control.

ERG Is a New Predisposition Gene for Bone Marrow Failure and Hematological Malignancy

There remain gaps in our knowledge of hereditary and sporadic causes of hematological malignancy (HM) and bone marrow failure (BMF) that prevent optimal diagnosis, disease surveillance and treatment. Here we report the discovery of ERG as a novel predisposition gene for BMF and HM. ERG is a known oncogene, typically via gene-fusions, leading to dysregulated ERG overexpression in blood and solid cancers. We identified a germline ERG ETS domain variant p.Y373C segregating with thrombocytopenia in a mother, who progressed to AML (27 yr) and then therapy-related MDS (35 yr), and in her 2 sons. All three showed copy neutral loss of heterozygosity of all or part of chromosome 21q, including the ERG locus, with the oldest son showing at least 2 somatic genetic rescue (SGR) events. The possibility of causal RUNX1 variants were ruled out, with the smallest somatic cnLOH event beginning within the RUNX1 gene, but not encompassing the RUNT domain where the majority of pathogenic missense variants are located. ERG, a highly constrained gene (LOEUF &amp;lt;0.33), is critical for definitive hematopoiesis, adult hematopoietic stem cell (HSC) function and platelet maintenance. An identical corresponding heterozygous germline variant (p.Y343C) in ERG’s closest gene by homology, FLI1, causes platelet-type bleeding disorder-21 (BDPLT21, OMIM #617443). Through global collaborations, we have identified 15 heterozygous variants in the ERG gene, 13 of which are missense and 2 truncating variants, in 17 individuals with cytopenia and/or HM (mainly myeloid) or lymphedema (Table). Onset of hematological symptoms ranged from birth to 38 years for truncating and constrained ETS domain variants. Of these 15 variants, 12 have been confirmed germline including 2 de novo. Only 4 meiotic transmissions are observed. None of the missense variants in the highly conserved ETS domain of ERG which mediates DNA binding, protein-protein interactions and nuclear localization, are present in gnomAD. We have functionally characterized 19 ERG variants, 12 potentially pathogenic, 1 known mouse pathogenic variant and 3 population controls demonstrating that most ETS domain missense variants display loss-of-function (LOF) characteristics disrupting transcriptional transactivation (Figure), DNA-binding and/or nuclear localization in vitro. Robust preliminary data from ex vivo models of ERG overexpression in mouse fetal liver cells in tissue culture (cytokine-independence), a mouse transplant assay and previous germline mutant Erg mouse models are concordant with ETS domain missense variants being LOF compared to wildtype ERG and benign controls. Together, these data provide clinical, in vitro and ex vivo functional studies implicating LOF variants in hematological disease predisposition. LOF ERG mutations also occur in sporadic cases of HM. Recently, as part of a Genomics England Research Consortium population study, 4 truncating ERG variants were described in 7 individuals across 4 families with 3 meiotic transmissions and a de novo case with primary lymphedema (1) and we add 2 novel missense variants here. One patient showed SGR across the ERG locus in blood. Blood phenotypes were not described. Our results demonstrate that germline ERG variants predispose to diverse cytopenia, BMF and HM in both children and adults. In our family mentioned above, the mother received an unrelated alloHSCT due to t-MDS while her 2 sons with cytopenias continue to be monitored. The natural history of this new syndrome will require careful identification of germline lesions with additional longitudinal studies in more patients and families needed. This ERG syndrome parallels GATA2 deficiency syndrome (HM and lymphedema) and RUNX1 Familial Platelet disorder-myeloid malignancy (thrombocytopenia and HM). Like the well-known disease genes GATA2 and RUNX1, ERG is also a member of the transcription factor heptad involved in HSC maintenance and differentiation. ERG adds to a growing list of genes whose unregulated expression contributes to HM and other cancers. Identification of causal germline ERG variants like those outlined in this study, has direct clinical implications for patient and family management including diagnosis, counselling, surveillance and treatment strategies such as selection of bone marrow transplant donors and potential for targeted therapies including gene and cell therapy. Reference 1. Greene D et al. Nat.Med. 29:679-688 2023

More problems, more money: Identifying and predicting high-cost rescue after colorectal surgery

BackgroundSuccessful rescue after elective surgery is associated with increased healthcare costs, but costs vary widely. Treating all rescue events the same may overlook targeted opportunities for improvement. The purpose of this study was to predict high-cost rescue after elective colorectal surgery. MethodsWe identified adult patients in the National Inpatient Sample (2016–2021) who underwent elective colectomy or proctectomy. Rescued patients were defined as those who underwent additional major procedures. Three groups were stratified: 1) uneventful recovery; 2) Low-cost rescue; 3) High-cost rescue. Multivariable Poisson regression was used to identify preoperative clinical predictors of high-cost versus low-cost rescue. ResultsWe identified 448,590 elective surgeries, and rescued patients composed 4.8 %(21,635) of the total sample. The median increase in costs in rescued patients was $25,544(p < 0.001). Median total inpatient costs were $95,926 in the most expensive rescued versus $34,811 in the less expensive rescued versus $16,751 in the uneventfully discharged(p < 0.001). When comparing the secondary procedures between the less expensive and most expensive rescued groups, the most expensive had an increased proportion of reoperation (73.4 % versus 53.0 %,p < 0.001). When controlling for other factors and stratification by congestive heart failure due to an interaction effect, a reoperation was independently associated with high-cost rescue (RR with CHF = 3.29,95%CI:2.69–4.04; RR without CHF = 2.29,95%CI:1.97–2.67). ConclusionsHigh-cost rescue after colorectal surgery is associated with disproportionately greater healthcare utilization and reoperation. For cost-conscious care, preemptive strategies that reduce reoperation-related complications can be prioritized.

Breakdown of Phospholipid Asymmetry Triggers ADAM17-Mediated Rescue Events in Cells Undergoing Apoptosis.

ADAM17, a prominent member of the "Disintegrin and Metalloproteinase" (ADAM) family, controls vital cellular functions through the cleavage of transmembrane substrates, including epidermal growth factor receptor (EGFR) ligands such as transforming growth factor (TGF)-alpha and Epiregulin (EREG). Several ADAM17 substrates are relevant to oncogenesis and tumor growth. We have presented evidence that surface exposure of phosphatidylserine (PS) is pivotal for ADAM17 to exert sheddase activity. The scramblase Xkr8 is instrumental for calcium-independent exposure of PS in apoptotic cells. Xkr8 can be dually activated by caspase-3 and by kinases. In this investigation, we examined whether Xkr8 would modulate ADAM17 activity under apoptotic and non-apoptotic conditions. Overexpression of Xkr8 in HEK293T cells led to significantly increased caspase-dependent as well as PMA-induced release of EREG and TGF-alpha. Conversely, siRNA-mediated downregulation of Xkr8 in colorectal Caco-2 cancer cells led to decreased PS externalization upon induction of apoptosis, which was accompanied by reduced shedding of endogenously expressed EREG and reduced cell survival. We conclude that Xkr8 shares with conventional scramblases the propensity to upmodulate the ADAM-sheddase function. Liberation of growth factors could serve a rescue function in cells on the pathway to apoptotic death.

Time-Efficient Identification Procedure for Neurological Complications of Rescue Patients in an Emergency Scenario Using Hardware-Accelerated Artificial Intelligence Models

During an emergency rescue operation, rescuers have to deal with many different health complications like cardiovascular, respiratory, neurological, psychiatric, etc. The identification process of the common health complications in rescue events is not very difficult or time-consuming because the health vital symptoms or primary observations are enough to identify, but it is quite difficult with some complications related to neurology e.g., schizophrenia, epilepsy with non-motor seizures, or retrograde amnesia because they cannot be identified with the trend of health vital data. The symptoms have a wide spectrum and are often non-distinguishable from other types of complications. Further, waiting for results from medical tests like MRI and ECG is time-consuming and not suitable for emergency cases where a quick treatment path is an obvious necessity after the diagnosis. In this paper, we present a novel solution for overcoming these challenges by employing artificial intelligence (AI) models in the diagnostic procedure of neurological complications in rescue situations. The novelty lies in the procedure of generating input features from raw rescue data used in AI models, as the data are not like traditional clinical data collected from hospital repositories. Rather, the data were gathered directly from more than 200,000 rescue cases and required natural language processing techniques to extract meaningful information. A step-by-step analysis of developing multiple AI models that can facilitate the fast identification of neurological complications, in general, is presented in this paper. Advanced data analytics are used to analyze the complete record of 273,183 rescue events in a duration of almost 10 years, including rescuers’ analysis of the complications and their diagnostic methods. To develop the detection model, seven different machine learning algorithms-Support Vector Machine (SVM), Random Forest (RF), K-nearest neighbor (KNN), Extreme Gradient Boosting (XGB), Logistic Regression (LR), Naive Bayes (NB) and Artificial Neural Network (ANN) were used. Observing the model’s performance, we conclude that the neural network and extreme gradient boosting show the best performance in terms of selected evaluation criteria. To utilize this result in practical scenarios, the paper also depicts the possibility of embedding such machine learning models in hardware like FPGA. The goal is to achieve fast detection results, which is a primary requirement in any rescue mission. An inference time analysis of the selected ML models and VTA AI accelerator of Apache-TVM machine learning compiler used for the FPGA is also presented in this research.

Abstract A51: Divergent effects of MDS predisposing SAMD9L point mutations, in humans, mice, and cellular models

Abstract We previously showed that germline SAMD9 and SAMD9L (SAMD9/9L) disorders are the most common predisposition to childhood myelodysplastic syndromes with bone marrow failure (BMF). Heterozygous mutations in both genes are growth inhibitory and undergo negative selection by acquiring compensatory rescue events in blood. Here, we describe the first report of SAMD9L genetic rescue occurring during embryonal development and resulting in germline triple-allelic mosaicism (1 wildtype (WT) and 2 mutant alleles), where only one mutant allele was transmitted to each of the two diseased children. In a family of 2 affected siblings with hypocellular BMF, the Index case carried germline heterozygous SAMD9L V1512M mutation and her brother was heterozygous for V1512L mutation. The clinical presentation for Index with V1512M was more severe compared to her brother with V1512L mutation. Genetic assessment of the parents showed the asymptomatic mother to be a triple-allelic mosaic, carrying WT SAMD9L allele at ~50% frequency in all tissues, while both V1512M and V1512L mutant alleles “competed” in their allelic distribution depending on the tissue origin. Single-cell DNA sequencing on her peripheral blood (PB) revealed 3 independent diploid clones: V1512M in 14%, V1512L in 68%, and WT (due to revertant UPD7q) in 18% of cells. Because her parents were SAMD9L WT, one of the mutations likely arose de novo and underwent failed embryonic rescue attempt leading to a second mutation. Towards studying the effect on hematopoiesis in vitro, we knocked in V1512M and V1512L mutations in inducible pluripotent stem cells (iPSC). For in vivo functional validation, we created constitutive mouse models with ortholog mutations (V1507M and V1507L). Mutant hematopoietic progenitor cells from iPSC had severely compromised proliferative capacity and yielded fewer erythroid and myeloid cells. This effect was more severe in V1512M vs. V1512L mutants. The divergent mutational phenotypes were also replicated in our mouse models: two-thirds (13/19) of the heterozygous V1507M (V1507Mhet) pups died before 4 weeks of age. In contrast, V1507Lhet mice had overall survival equal to WT mice, while one-third of homozygous V1507L (V1507Lhom) mice showed decreased survival post 19 weeks of age. At baseline, V1507Mhet mice showed severe growth retardation with multisystemic issues, which were absent in the V1507L mutant models. PB cytopenia (anemia, B-cell lymphopenia) though observed in both V1507Mhet and V1507Lhom mice, the degree of severity was high in the V1507Mhet than in the V1507Lhom model. Meanwhile, V1507Lhet mice had blood counts similar to WT. In summary, V1512M compared to V1512L mutation resulted in a more severe phenotype in all analyzed model systems. This observation showed how different mutational permutations of the same amino acid can exert divergent phenotypic effects in SAMD9L BMF disorder. Therefore, together with our genetic analysis, we could postulate that the V1512L mutation arose as a failed rescue attempt of V1512M during embryogenesis. Citation Format: Sushree S Sahoo, Charnise Goodings, Shondra M. Pruett-Miller, Maria A Lillo, Lei Han, Baranda Hansen, Ti-Cheng Chang, Tim Lammens, Mattias Hofmans, Marta Derecka, Barbara De Moerloose, Marcin W Wlodarski. Divergent effects of MDS predisposing SAMD9L point mutations, in humans, mice, and cellular models [abstract]. In: Proceedings of the AACR Special Conference: Acute Myeloid Leukemia and Myelodysplastic Syndrome; 2023 Jan 23-25; Austin, TX. Philadelphia (PA): AACR; Blood Cancer Discov 2023;4(3_Suppl):Abstract nr A51.

Somatic genetic reversion of large duplication event in IL2RG in siblings

BackgroundDeleterious mutations in the common gamma chain (γC, CD132) are associated with X-linked severe combined immunodeficiency (X-SCID) characterized by a T-B+NK- phenotype. Hypomorphic variants in the IL2RG gene have also been associated with a milder or atypical SCID phenotype. Milder phenotypes can also occur when somatic genetic rescue occurs in the setting of severe IL2RG mutations. Spontaneous somatic variants particularly in hematologic disorders can occur particularly in genes with known selection pressure including IL2RG. ResultsHere, we report the clinical and molecular findings from two brothers with atypical X-SCID phenotype including hypogammaglobulinemia, elevated IgM, T cell lymphopenia and extensive verruca plana. One brother required splenectomy secondary to a benign vascular tumor and had recurrent pancreatitis consistent with primary sclerosing cholangitis. Both brothers developed recurrent suppurative pneumonia resulting in early bronchiectasis in their first decade. Next generation sequencing initially was negative, yet reanalysis found a large duplication event in exon 3 of IL2RG gene with somatic genetic rescue events that occurred twice in two brothers. Functional studies revealed a unique mosaic pattern in each affected sibling when stimulating peripheral blood mononuclear cells with IL-2 or IL-21 resulting in bimodal phospho-STAT5 or phospho-STAT3 respectively. The genetic analysis revealed the maternal allele was heterozygous as expected, although the ratio of these events and clonal analysis revealed cell type skewing. ConclusionOur data demonstrate an atypical SCID phenotype in two brothers secondary to the combination of a large duplication event in the IL-2RG gene partially rescued by somatic genetic rescue. Although previous somatic reversion cases have been reported involving the IL2RG genetic locus, our cases demonstrate a large duplication reversion event with recurrence. Our case highlights the unique selection pressure to amplify rare genetic events at the IL2RG locus.

Special Vehicles and Equipment in Fire Operations Used in Different Regions

Different parts of the world have different disasters or fire and technical rescue events. Economic, infrastructural and natural environmental differences cause great variances. The nations employ various organisations, depending on the available possibilities, with diverse technical solutions to eliminate the sources of fire, disaster, incident dangers. In case of fires and technical rescue occasions that have already occurred and require intervention and pose a direct threat to human life, physical integrity and property, these tasks are typically performed by fire brigade organisations. These organisations also carry out more or less extensive activities in their areas of responsibility; however, national solutions may involve the use of firefighting vehicles and equipment that differ significantly from one neighbouring country to another.The article presents the general firefighting vehicles used internationally and in Hungary and their characteristic capabilities, together with the widely used technical equipment and devices worldwide, built-in or mobile firefighting machines. In this paper a wide-ranging inspection of firefighting vehicles are demonstrated, and the description of the firefighting equipment can be interpreted together with the carrier vehicles. By special fire engines, the author here means vehicles that are on standby in each country, but only in small numbers and only alerted a few times a year. An important aspect in this category is that the design and equipment of these firefighting vehicles are planned to eliminate special incident situations that are unlikely to occur, but pose a great threat to human life, physical integrity or the property of the country and citizens, even in the short term. The article focuses also on these less frequent, more specialised firefighting vehicles and technical devices, with a description of their typical deployment conditions.When drawing the conclusions, the ideas and solutions found during the international outlook worthy of Hungarian adaptation are presented. Here the national adaptation possibilities of each international, special firefighting vehicle, the advantages they can provide and the expected disadvantages are examined. The content of the article is a general summary that fills a gap due to the small amount of international literature, which can also be used during research, investigation and education in this research field.

Dynamics and length distributions of microtubules with a multistep catastrophe mechanism

Regarding the experimental observation that microtubule (MT) catastrophe can be described as a multistep process, we extend the Dogterom–Leibler model for dynamic instability in order to discuss the effect that such a multistep catastrophe mechanism has on the distribution of MT lengths in the two regimes of bounded and unbounded growth. We show that in the former case, the steady state length distribution is non-exponential and has a lighter tail if multiple steps are required to undergo a catastrophe. If rescue events are possible, we detect a maximum in the distribution, i.e. the MT has a most probable length greater than zero. In the regime of unbounded growth, the length distribution converges to a Gaussian distribution whose variance decreases with the number of catastrophe steps. We extend our work by applying the multistep catastrophe model to MTs that grow against an opposing force and to MTs that are confined between two rigid walls. We determine critical forces below which the MT is in the bounded regime, and show that the multistep characteristics of the length distribution are largely lost if the growth of an MT in the unbounded regime is restricted by a rigid wall. All results are verified by stochastic simulations.

Germline SAMD9/9L MDS Predisposition Syndromes Are Characterized By Complex Clonal Architecture and Lineage-Specific Escape Mechanisms Including Somatic Genetic Rescue in T and B Lymphocytes

Inherited bone marrow failure (BMF) and MDS predisposition syndromes have an intrinsic defect resulting in loss and/or dysfunction of hematopoietic stem and progenitor cells (HSPC). HSPC clones can escape this process by acquiring gene- or genome-level genetic changes (compensatory mutations or uniparental disomies (UPD)) thereby increasing cellular fitness. This process, referred to as somatic genetic rescue (SGR) has been shown to occur in >70% of patients with gain-of-function mutations in SAMD9 and SAMD9L (SAMD9/9L) genes, which are a common cause of early onset BMF and pediatric MDS with monosomy 7. It is unknown how SGR arises and in which cells it originates. Furthermore, little is known about the epistatic interactions of various rescue events. We aimed to address these questions by utilizing a newly established single cell (sc)-proteogenomic platform that can simultaneously detect single nucleotide variants (SNVs) and copy number variation (CNVs) in addition to protein expression. We applied this technology to study clonal architecture and cellular origins of SGR lesions in a cohort of clinically annotated SAMD9/9L-mutated (SAMD9/9Lmut) patients. We also asked if monosomy 7, traditionally assessed by karyotyping, can be also detected in peripheral blood (PB) of affected patients. We first performed whole exome and panel sequencing to characterize 67 germline SAMD9/9Lmut patients. Guided by this data, we designed a sc-proteogenomic panel with 69 amplicons specific to variants in SAMD9/9L and leukemia driver genes, and 250 amplicons covering high-frequency SNVs on chromosome 7q. For validation of initial findings, we developed a second panel targeting full coding regions of SAMD9/9L genes, and additional 7p SNVs allowing for a precise delineation of uniparental isodisomy 7q (UPD7q). We included oligonucleotide-conjugated antibodies specific to major hematopoietic antigens, including CD19, CD3, CD11b, CD38 and CD34. Using this panel, we analyzed 22 samples (15 bone marrow (BM) and 7 PB) of 10 patients enrolled in local biobanking protocols. On average, 3,845 high-quality cells were genotyped per sample, and we robustly identified SNVs, monosomy 7 and UPD7q changes in single cells. Somatic rescue SAMD9/9Lmut were found only in clones with normal (diploid) chromosome 7, UPD7q (containing two wild type SAMD9/9L alleles after mitotic recombination event) was a stand-alone clone, while monosomy 7 (SAMD9/9Lmut lost) occurred alone or together with leukemia driver mutations. We also detected lesions that were previously missed using routine clinical sequencing in 3 patients (somatic SAMD9/9Lmut or UPD7q). Most patients had branching clonal architecture (i.e., independent monosomy 7, UPD7q, and somatic SAMD9/9Lmut), while linear trajectories were rare (i.e., monosomy 7 à + leukemia driver mutation). Serial assessment of 4 patients with stable hematology (3 with monosomy 7 and 1 with an additional somatic SAMD9/9Lmut) for a period of up to 4.8 years, revealed stable clonal populations without acquisition of additional driver mutations. Quantification of clones in paired BM and PB in 4 patients demonstrated equal frequencies of monosomy 7 and somatic SAMD9/9Lmut in both compartments, demonstrating the utility of this assay in surveillance. Our findings were confirmed by sorting BM cells into different lineages followed by sequencing, error-corrected sequencing, and ddPCR. Finally, analysis of protein expression data revealed that while monosomy 7 is present exclusively in cells with myeloid phenotype, the SGR events can arise in lymphocyte lineage only; 4 patients carried clones with somatic SAMD9/9Lmut in CD3+ lymphocytes, and 2 patients had UPD7q clones in either CD3+ or CD19+ lymphocytes. These findings provide clues why most of the SGR events in patients do not result in long-lasting clinical remission since the genetic rescue can be restricted only to certain hematopoietic lineages. In conclusion, single cell proteogenomic analysis is useful for the understanding the mechanisms of clonal evolution in SAMD9/9L syndromes. This method also offers the opportunity for less invasive surveillance of karyotype abnormalities from peripheral blood in patients who are at high risk for MDS progression.

Mutational Permutations of a Single Amino Acid Exert Divergent Phenotypic Effects in Human, Mice, and Cellular Models of SAMD9L Bone Marrow Failure Disorder

While characterizing the new SAMD9 and SAMD9L - related bone marrow failure syndromes, we found that different germline pathogenic mutations can occur at the same amino acid position (Sahoo, Nat, Medicine 2021). Here, we explore this phenomenon by studying a family with triple allelic mosaicism in SAMD9L and two mutational permutations of the same amino acid in different children. We applied genomic methods (exome sequencing, Sanger, error-corrected sequencing, FISH, single-cell DNA sequencing (scDNAseq), ddPCR, and PacBio haplotype sequencing), developed stable mutant HEK293 cell lines, created V1512M and V1512Lmutant inducible pluripotent stem cells (iPSC) and ortholog mutant mouse models with Samd9l heterozygous (V1507Mhet, V1507Lhet) and homozygous (V1507Lhom) mutations using CRISPR/Cas9 engineering. In a family with SAMD9L-related bone marrow failure, the affected girl carried heterozygous c.4534G>A (V1512M) mutation, while her brother was heterozygous for c.4534G>T (V1512L) mutation. Both mutations were germline and confirmed to arise from the same haplotype. The child with V1512M also carried somatic rescue events (del7q, acquired SAMD9L mutation) and had a more severe clinical phenotype. The asymptomatic mother who had normal diploid karyotype was a triple-allelic mosaic. The SAMD9L wildtype (WT) allele was present at ~50% frequency in all tissues, while both mutant alleles present in the remaining 50% of reads "competed" in their allelic distribution depending on the tissue origin (hematopoietic cells: V1512M ~9% and V1512L ~41%, hair follicles: both at ~25%). ScDNAseq revealed 3 separate clonal populations in blood, all with biallelic configuration: SAMD9L V1512M in 14%, V1512L in 68%, and WT (with acquired uniparental isodisomy 7q) in 18% of cells. Because her parents were SAMD9L WT, one of the mutations likely arose de novo and underwent failed rescue attempt during embryogenesis leading to a second mutation. Overexpression studies in HEK293 cells demonstrated significant growth inhibition of mutants (V1512M more severe than V1512L) compared to WT. Hematopoietic progenitor cells (HPC) derived from mutated iPSC had severely compromised proliferative capacity, and differentiation of V1512M and V1512L HPC yielded significantly fewer CD235+CD71+ erythroid cells and severely decreased CD45+CD33+ myeloid cells; in both lineages, V1512M mutation had the most severe phenotype. We also observed divergent mutational phenotypes in mice: two-thirds (13/19) of the Samd9l V1507Mhet pups died before weaning and the vast majority died within the first 2 weeks of life. On the contrary, V1507Lhet mice had overall survival equal to WT mice, while V1507Lhom mice had a trend of decreased survival with 40% of mice dying by 19 weeks. At baseline, Samd9l V1507Mhet mice showed severe growth retardation with multisystem involvement (kidney, ovary, and alimentary tract), while V1507Lhet and V1507Lhom mice had no such abnormalities. The histology of BM and spleen in >7 weeks old V1507Mhet mice showed decreased erythroid and increased myeloid precursors in BM with extramedullary hematopoiesis. Significant multi-lineage peripheral blood (PB) cytopenia were observed in V1507Mhet mice compared to WT littermates. V1507Lhet mice had normal PB counts and BM phenotype comparable to WT, while V1507Lhom mice had isolated cytopenia and reduced numbers of BM erythroid and B-cells, and an increase in myeloid cells. Next, to induce replicative stress in V1507Lhom model, we performed non-competitive BM transplantation (BMT) into lethally irradiated B6.SJL/J WT recipients. At 12 weeks post BMT, there was a significant reduction of total V1507Lhom cell numbers with a decrease in B-cells, increase in myeloid cells, and no difference in T-cells. For V1507Mhet mice, we performed competitive BMT (because of the severe baseline phenotype), revealing significant changes post BMT, like V1507Lhom transplants, yet more severe and arising earlier. Altogether, our data suggest that Samd9l V1507Mhet and V1507Lhom cells have lower erythroid and B-cell output and a shift towards myelopoiesis. To our knowledge, this is the first report of germline triple-allelic mosaicism with bi-allelic segregation in humans. Our study establishes how different mutational permutations of the same amino acid exert divergent phenotypic effects in humans, mice, and cellular models of SAMD9L bone marrow failure disorder.

Low-level complex mosaic with multiple cell lines affecting the 18q21.31q21.32 region in a patient with de novo 18q terminal deletion

We describe a 5-year-old girl who was diagnosed at birth with 18q de novo homogeneous deletion at G-banding karyotype. Her clinical condition, characterized by hypotonia, psychomotor retardation, short stature, deafness secondary to bilateral atresia of the external auditory canals, was in agreement with the 18q deletion syndrome though presence of coloboma of a single eye only suggested a mosaic condition as an unusual sign. By combining multiple technologies including array-CGH, FISH, and WGS, we found that the terminal deletion 18q21.32q23 (21 Mb) was in segmental mosaicism of the proximal region 18q21.31q21.32 (2.7 Mb), which showed a variable number of copies: one, two, or three, in 7, 41 and 55% of the cells respectively. Breakpoint junction analysis demonstrated the presence of an inv-dup del (18q) with a disomic segment of 4.7 kb between the inverted and non-inverted copies of the duplicated region 18q21.31q21.32. From these results, we propose that all three types of abnormal chr18 (the inv-dup del and the two 18q terminal deletions of different sizes) arisen from breaks in a dicentric mirror chromosome 18q, either in more than one embryo cell or from subsequent breaking-fusion-bridge cycles. The duplication region was with identical polymorphisms as in all non-recurrent inv-dup del rearrangements though, in contrast with most of them, the 18q abnormality was of maternal origin. Taking into account that distal 18q deletions are not rarely associated with inv-dup del(18q) cell lines, and that the non-disjunction of chromosome 18 takes place especially at maternal meiosis II rather than meiosis I, multiple rescue events starting from trisomic zygotes could be considered alternative to the postmitotic ones. From the clinical point of view, our case, as well as those of del(18q) in mosaic with the dic(18q), shows that the final phenotype is the sum of the different cell lines that acted on embryonic development with signs typical of both the 18q deletion syndrome and trisomy 18. Asymmetrical malformations, such as coloboma of the iris only in the right eye, confirm the underlying mosaicism regardless of whether it is still detectable in the blood.

Improve Cardiac Emergency Preparedness by Building a Team-Based Cardiopulmonary Resuscitation Educational Plan.

ObjectiveTo design an innovative team-based cardiopulmonary resuscitation (CPR) educational plan for multiple bystanders and evaluate whether it was associated with better teamwork and higher quality of resuscitation.MethodsThe team-based CPR plan defined the process for a three-person team, emphasize task allocation, leadership, and closed-loop communication. Participants qualified for single-rescuer CPR skills were randomized into teams of 3. The teamwork performance and CPR operation skills were evaluated in one simulated cardiac arrest scenario before and after training on the team-based CPR plan. The primary outcomes were measured by the Team Emergency Assessment Measure (TEAM) scale and chest compression fraction (CCF).ResultsForty-three teams were included in the analysis. The team-based CPR plan significantly improved the team performance (global rating 6.7 ± 1.3 vs. 9.0 ± 0.7, corrected p < 0.001 after Bonferroni's correction). After implementing the team-based CPR plan, CCF increased [median 59 (IQR 48–69) vs. 64 (IQR 57–71%)%, corrected p = 0.002], while hands-off time decreased [median 233.2 (IQR 181.0–264.0) vs. 207 (IQR 174–222.9) s, corrected p = 0.02]. We found the average compression depth was significantly improved through the team-based CPR training [median 5.1 (IQR 4.7–5.6) vs. 5.3 (IQR 4.9–5.5) cm, p = 0.03] but no more significantly after applying the Bonferroni's correction (corrected p = 0.35). The compression depths were significantly improved by collaborating and exchanging the role of compression among the participants after the 6th min.ConclusionThe team-based CPR plan is feasible for improving bystanders teamwork performance and effective for improving resuscitation quality in prearrival care. We suggest a wide application of the team-based CPR plan in the educational program for better resuscitation performance in real rescue events.

Protocolizing perioperative OSA screening and management: moving in the right direction.

Protocolizing perioperative OSA screening and management: moving in the right direction.