Smooth Roads Ahead: Lessons From our Sick Neonate Retrieval Service

Strategies for free transfer of sick neonates to hospitals are in place, but reports suggest suboptimal status of the same across the country. Over 7 years, our Sick Neonate Retrieval Service (SNRS) transported 165 neonates, of whom 92.1% survived. Safe, stable transportation mandates the presence of a neonatology-trained doctor and nurse in an equipped ambulance.

Retrospective identification of cell-intrinsic factors that mark pluripotency potential in rare somatic cells

Pluripotency can be induced in somatic cells by the expression of OCT4, KLF4, SOX2, and MYC. Usually only a rare subset of cells reprogram, and the molecular characteristics of this subset remain unknown. We apply retrospective clone tracing to identify and characterize the rare human fibroblasts primed for reprogramming. These fibroblasts showed markers of increased cell cycle speed and decreased fibroblast activation. Knockdown of a fibroblast activation factor identified by our analysis increased the reprogramming efficiency. We provide evidence for a unified model in which cells can move into and out of the primed state over time, explaining how reprogramming appears deterministic at short timescales and stochastic at long timescales. Furthermore, inhibiting the activity of LSD1 enlarged the pool of cells that were primed for reprogramming. Thus, even homogeneous cell populations can exhibit heritable molecular variability that can dictate whether individual rare cells will reprogram or not.

Piscis: a novel loss estimator of the F1 score enables accurate spot detection in fluorescence microscopy images via deep learning

Single-molecule RNA fluorescence in situ hybridization (RNA FISH)-based spatial transcriptomics methods have enabled the accurate quantification of gene expression at single-cell resolution by visualizing transcripts as diffraction-limited spots. While these methods generally scale to large samples, image analysis remains challenging, often requiring manual parameter tuning. We present Piscis, a fully automatic deep learning algorithm for spot detection trained using a novel loss function, the SmoothF1 loss, that approximates the F1 score to directly penalize false positives and false negatives but remains differentiable and hence usable for training by deep learning approaches. Piscis was trained and tested on a diverse dataset composed of 358 manually annotated experimental RNA FISH images representing multiple cell types and 240 additional synthetic images. Piscis outperforms other state-of-the-art spot detection methods, enabling accurate, high-throughput analysis of RNA FISH-derived imaging data without the need for manual parameter tuning.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Risk profiles and incidence of cardiovascular events across different cancer types

BACKGROUND

Cancer survivors are at increased risk for cardiovascular (CV) disease, although additional data are needed to better understand the incidence of CV events across different malignancies. This study sought to characterize the incidence of major adverse CV events [myocardial infarction, stroke, unstable angina (MACE), or heart failure (HF)] across multiple cancer types after cancer diagnosis.

PATIENTS AND METHODS

Patients were identified from a USA-based administrative claims database who had index cancer diagnoses of breast, lung, prostate, melanoma, myeloma, kidney, colorectal, leukemia, or lymphoma between 2011 and 2019, with continuous enrollment for ≥12 months before diagnosis. Baseline CV risk factors and incidence rates of CV events post-index were identified for each cancer. Multivariable Cox hazards models assessed the cumulative incidence of MACE, accounting for baseline risk factors.

RESULTS

Among 839 934 patients across nine cancer types, CV risk factors were prevalent. The cumulative incidence of MACE was highest in lung cancer and myeloma, and lowest in breast cancer, prostate cancer, and melanoma. MACE cumulative incidence for lung cancer was 26% by 4 years (2.7-fold higher relative to breast cancer). The incidence of stroke was especially pronounced in lung cancer, while HF was highest in myeloma and lung cancer.

CONCLUSIONS

CV events were especially increased following certain cancer diagnoses, even after accounting for baseline risk factors. Understanding the variable patient characteristics and associated CV events across different cancers can help target appropriate CV risk factor modification and develop strategies to minimize adverse CV events and improve patient outcomes.

Heart rate and heart rate variability following sleep deprivation in retired night shift workers and retired day workers

Shift workers experience poor sleep and dysregulated cardiac autonomic function during sleep. However, it is unknown if this dysregulation persists into retirement, potentially accelerating the age-associated risk for adverse cardiovascular outcomes. Using sleep deprivation as a physiological challenge to cardiovascular autonomic function, we compared heart rate (HR) and high-frequency heart rate variability (HF-HRV) during baseline and recovery sleep following sleep deprivation between retired night shift and day workers. Participants were retired night shift (N = 33) and day workers (N = 37) equated on age (mean [standard deviation] = 68.0 [5.6] years), sex (47% female), race/ethnicity (86% White), and body mass index. Participants completed a 60-h lab protocol including one night of baseline polysomnography-monitored sleep, followed by 36 h of sleep deprivation and one night of recovery sleep. Continuously recorded HR was used to calculate HF-HRV. Linear mixed models compared HR and HF-HRV during non-rapid eye movement (NREM) and REM sleep between groups during baseline and recovery nights. Groups did not differ on HR or HF-HRV during NREM or REM sleep (ps > .05) and did not show differential responses to sleep deprivation. In the full sample, HR increased and HF-HRV decreased from baseline to recovery during NREM (ps < .05) and REM (ps < .01). Both groups exhibited cardiovascular autonomic changes during recovery sleep following 36 h of sleep deprivation. Sleep deprivation appears to induce cardiovascular autonomic changes that persist into recovery sleep in older adults, regardless of shift work history.

AN IN-DEPTH ASSESSMENT OF THE TUMOR'S IMPACT ON SARCOPENIA

Loss of muscle mass is a typical symptom of cancer and it is strongly correlated with poor prognosis. Cancer-related Sarcopenia is unresponsive to conventional dietary changes and exercise, in contrast to age-associated muscle atrophy. This particular type of weakness differs from different kinds of muscle loss in that it is triggered by a number of interrelated mechanisms, notably inflammatory processes, abnormal metabolic processes, proteolysis, and autophagy. This research is to examine evidence supporting the theory that tumors have a causal role in causing muscular atrophy. It seeks to investigate the precise regulators that the tumour generates and how they affect the processes that result in muscle waste. The evaluation looks for new directions for further studies and medical treatments. The analysis is based on a thorough examination of the scientific literature and research that shows how tumor and muscle atrophy are related. It concentrates on studies that clarify the numerous strategies by which malignancies cause the loss of muscle. This article highlights particular mechanisms by which these tumor-derived substances affect the development of muscle loss, including inflammatory processes, metabolic disturbance, proteolysis, and autophagy. The discovery of such targets offers hope for the creation of efficient treatment strategies that can enhance the long-term outlook and quality of life of cancer sufferers who are experiencing muscle loss.

Dorsal Column Myelopathy Following Intrathecal Chemotherapy for Leukemia

PURPOSE/OBJECTIVE(S)

Intrathecal (IT) methotrexate (Mtx) and/or cytarabine (AraC) improve CNS disease control in patients (pts) with hematologic malignancies. There are increasing number of case reports of irreversible, primarily dorsal column myelopathy in pts treated with IT chemotherapy. By describing the largest case series of myelopathy following IT chemotherapy, we aim to raise awareness about this devastating albeit rare complication.

MATERIALS/METHODS

We retrospectively reviewed 25 pts with leukemia who developed paraplegia following IT chemotherapy between 2/2006 and 9/2021. Clinical/treatment characteristics, response, and toxicity were extracted from the medical records.

RESULTS

Seventeen pts (68%) were male, 16 had B-cell ALL (64%), 4 had AML (16%), 2 had CML (8%), 2 had T-ALL (8%), and 1 had BPDCN (4%). The median age at diagnosis was 38 years (IQR 30-59). All pts required systemic salvage treatment after induction chemotherapy with a median number of 3 regimens received (IQR 2-5.5). In total, the median number of IT treatments was 19 per pt (IQR 14-27). Most pts (84%, n = 21) received single agent IT Mtx alternating with single agent AraC. Fifteen pts (60%) received triple IT therapy with a median of 3 treatments (IQR 0-8). Prior to the onset of myelopathy, 10 pts (40%) received allogeneic SCT and 9 pts (36%) were treated with radiation therapy. Median follow-up from diagnosis was 1.9 yrs (IQR 1.3-4.1). Myelopathy was progressive and irreversible in all pts (n = 25); 84% (n = 21) experienced sensory loss, and all pts had extremity weakness. Symptoms were ascending in 11 pts (44%) and descending in 4 pts (16%). Irreversible bowel/bladder incontinence developed in 12 pts (48%). CSF analysis at the time of symptom onset was negative for leukemia cells in most pts (n = 21, 84%) and showed malignant cells in 4 pts (16%). CSF studies showed elevated protein in 21 pts (84%). Myelin basic protein was elevated in all 13 assessed pts. On T2 weighted spinal MRI, all pts had enhancement of the dorsal columns, including 80% of pts with this dorsal column abnormality reported at the time of the study and 20% of pts (n = 5) with the dorsal enhancement noted retrospectively. Due to concern for occult disease, 20 pts (80%) received additional CNS-directed therapy after symptom onset. Twenty-two pts (88%) died at last follow-up. The time between neurological symptom onset and death was a median 3.5 months (IQR 2.6 and 5). Three pts (12%) are alive with paraplegia at a median of 4.4 years from symptom onset.

CONCLUSION

Dorsal column myelopathy is a rare but devastating condition that can occur after IT chemotherapy in heavily pre-treated leukemia pts. T2 weighted spinal MRI can be helpful in the evaluation of pts that present with unexplained weakness and sensory changes. We recommend delaying additional CNS-directed therapy until work-up to rule out alternative etiologies is complete. Future strategies are desperately needed to address this irreversible treatment complication.

Diverse clonal fates emerge upon drug treatment of homogeneous cancer cells

Even among genetically identical cancer cells, resistance to therapy frequently emerges from a small subset of those cells1-7. Molecular differences in rare individual cells in the initial population enable certain cells to become resistant to therapy7-9; however, comparatively little is known about the variability in the resistance outcomes. Here we develop and apply FateMap, a framework that combines DNA barcoding with single-cell RNA sequencing, to reveal the fates of hundreds of thousands of clones exposed to anti-cancer therapies. We show that resistant clones emerging from single-cell-derived cancer cells adopt molecularly, morphologically and functionally distinct resistant types. These resistant types are largely predetermined by molecular differences between cells before drug addition and not by extrinsic factors. Changes in the dose and type of drug can switch the resistant type of an initial cell, resulting in the generation and elimination of certain resistant types. Samples from patients show evidence for the existence of these resistant types in a clinical context. We observed diversity in resistant types across several single-cell-derived cancer cell lines and cell types treated with a variety of drugs. The diversity of resistant types as a result of the variability in intrinsic cell states may be a generic feature of responses to external cues.

Effect of Clinician-directed Technical Specifications on Entrance Skin Doses in Neonates

OBJECTIVE

To compare the entrance skin doses (ESD) before and after implementation of a radiation safety policy in neonates (RSN), which focused on clinician-directed technical specifications on the digital X-ray machine.

METHODS

Prospective observations included two sets of X-rays: Before (BRSN) and after (ARSN) implementation of RSN (documented indication for X-ray/expected posttest findings, settings of 40 kVp, 0.5 mAs, film-focus distance 100 cm, gonadal-shield, optimal collimation, and post-shoot image-enhancement).

RESULTS

33 and 32 X-rays were analyzed in respective groups. Mean (SD) of calculated and machine-quantified ESD (µGy/m2) was higher in BRSN group as compared to ARSN group (P <0.001). All ARSN X-rays were interpretable for expected post-test findings.

CONCLUSION

Clinicians' cognizance of ability to make consequential bedside technical specifications, can reduce ESD without affecting interpretability. These single observations could have a larger impact in sick neonates, where multiple X-rays are done.

Single cell susceptibility to SARS-CoV-2 infection is driven by variable cell states

The ability of a virus to infect a cell type is at least in part determined by the presence of host factors required for the viral life cycle. However, even within cell types that express known factors needed for infection, not every cell is equally susceptible, suggesting that our knowledge of the full spectrum of factors that promote infection is incomplete. Profiling the most susceptible subsets of cells within a population may reveal additional factors that promote infection. However, because viral infection dramatically alters the state of the cell, new approaches are needed to reveal the state of these cells prior to infection with virus. Here, we used single-cell clone tracing to retrospectively identify and characterize lung epithelial cells that are highly susceptible to infection with SARS-CoV-2. The transcriptional state of these highly susceptible cells includes markers of retinoic acid signaling and epithelial differentiation. Loss of candidate factors identified by our approach revealed that many of these factors play roles in viral entry. Moreover, a subset of these factors exert control over the infectable cell state itself, regulating the expression of key factors associated with viral infection and entry. Analysis of patient samples revealed the heterogeneous expression of these factors across both cells and patients in vivo. Further, the expression of these factors is upregulated in particular inflammatory pathologies. Altogether, our results show that the variable expression of intrinsic cell states is a major determinant of whether a cell can be infected by SARS-CoV-2.

Abstract 1785: Multi-step engineering of gene-edited CAR T cells using RNA lipid nanoparticles

Autologous chimeric antigen receptor (CAR) T therapies utilize patient cells and can be limited by cell quality, and the high manufacturing burden of viral vectors. As such, there is a need for allogeneic, “off-the-shelf” CAR T cells to make these transformative treatments widely available. However, allogeneic therapies require multiple genetic engineering steps to express CAR and to delete proteins responsible for graft-versus-host disease. Messenger RNA (mRNA) is a promising approach for expression of therapeutic proteins and gene editing nucleases. In this work, we demonstrate a new method for multi-step engineering of gene-edited CAR T cells using RNA lipid nanoparticles (LNPs).

LNPs encapsulating Spy-Cas9 mRNA, TCR and CD52 guide RNA (sgRNA), and CAR mRNA were produced using microfluidics. The CAR construct contained an anti-CD19 scFv binding domain and CD3ζ/4-1BB co-stimulatory domains. Microgram quantities of RNA LNPs were produced to optimize LNP packaging, cargo ratios, and sgRNA combinations. Lead candidates were scaled to milligrams. Purified human primary T cells were cultured, activated, and expanded in serum-free media in plates, flasks and bioreactors. CAR+, TCR− or CD52− cells were generated by addition of the corresponding LNP to activated cells. Cytotoxic killing was determined by co-culture assays with leukemia cells. Gene knockout, CAR expression, viability and cell killing were measured using flow-cytometry.

CD19 CAR was selected as a relevant protein for expression, with TCR and CD52 proteins as gene knockout targets. Single-step addition of CAR LNPs to T cells resulted in transfection efficiencies of 95.0 ± 2.1% and high protein expression. Upon TCR or CD52 LNP addition to T cells, the onset of gene editing was within 48 hours, reaching single target knockout efficiencies of 92.3 ± 3.0% (TCR−), and double knockouts (TCR−/CD52−) of 74.5 ± 6.1%. Similar results were obtained when comparing different LNP batch sizes (microgram to milligram RNA) and cell culture vessels (125,000 to 45 million cells), demonstrating scalability of both the LNP production and cell treatment. Cell viabilities above 90% were maintained at all steps and for all RNA LNPs. Finally, as proof-of-concept for multi-step engineering, sequential addition of TCR LNPs and CAR LNPs resulted in simultaneous CAR expression and TCR gene knockout. These “off-the-shelf” gene-edited CAR T cells were functionally equivalent to non-edited cells in a B cell killing assay, efficiently clearing over 80% of leukemia target cells at a 1:1 ratio.

Our findings demonstrate the advantages of LNPs for RNA delivery to T cells. The simple and gentle nature of LNP cell treatment allows for multiple genetic engineering steps for simultaneous expression and deletion of proteins. Furthermore, LNPs can be easily manufactured using microfluidics, enabling small-scale screening of RNA libraries and rapid scale-up of lead candidates for clinical translation.

Citation Format: Samuel Clarke, R Geczy, A Balgi, S Park, R Zhao, M Swaminathan, R Tieu, N Hoang, C Webb, E Watt, M Wong, M Fujisawa, N Jain, Angela Zhang, Anitha Thomas. Multi-step engineering of gene-edited CAR T cells using RNA lipid nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1785.

Cardiorespiratory Adverse Events after First Vaccination in Preterm Neonates With Gestational Age <30 Weeks

OBJECTIVES

To document the adverse cardiorespiratory events following first routine immunization in preterm neonates.

METHODS

We retrieved records of neonates with gestational age ≤30 weeks, who developed cardio-respiratory events after first vaccines before discharge. Our Unit's protocol is to administer Bacillus Calmette-Guerin (BCG), hepatitis B vaccine to those discharged at <8 weeks postnatal age. Hexavalent, BCG, pneumococcal vaccine and rotavirus vaccines are given at 8 weeks of age, if hospital stay is predicted to be longer. Unit compliance to vaccination administration at appropriate ages were also measured.

RESULTS

Data of 161 neonates ≤ 30 weeks (17.4% <27 week) who completed care in the unit was studied. Cardio-respiratory adverse events were reported in 21(13.7%). None of these required initiation of invasive ventilation. High flow nasal cannula therapy and caffeine restart were required for these events in 14 (9.3%) and 6 (3.9%) neonates, respectively. Lower gestational age, bronchopulmonary dysplasia and sepsis were significant risk factors on univariate analysis. On multivariate analysis, continued need for respiratory support at 4 weeks of age (P=aOR 14.5 (95% CI 5-59.1) was the only independent risk factor for post-vaccination cardiorespiratory adverse events. Of 38 who were not vaccinated at recommended ages by unit policy, 25 were missed opportunities, the rest were deemed unstable for vaccinations at that age by the clinical team.

CONCLUSION

Adverse cardiorespiratory events were uncommon after first vaccinations in very preterm neonates. Administering vaccines to these before discharge would allow monitoring for these events, especially for those who require long-term respiratory support.

Retrospective identification of intrinsic factors that mark pluripotency potential in rare somatic cells

Pluripotency can be induced in somatic cells by the expression of the four "Yamanaka" factors OCT4, KLF4, SOX2, and MYC. However, even in homogeneous conditions, usually only a rare subset of cells admit reprogramming, and the molecular characteristics of this subset remain unknown. Here, we apply retrospective clone tracing to identify and characterize the individual human fibroblast cells that are primed for reprogramming. These fibroblasts showed markers of increased cell cycle speed and decreased fibroblast activation. Knockdown of a fibroblast activation factor identified by our analysis led to increased reprogramming efficiency, identifying it as a barrier to reprogramming. Changing the frequency of reprogramming by inhibiting the activity of LSD1 led to an enlarging of the pool of cells that were primed for reprogramming. Our results show that even homogeneous cell populations can exhibit heritable molecular variability that can dictate whether individual rare cells will reprogram or not.

Long-term passive wastewater surveillance of SARS-CoV-2 for seven university dormitories in comparison to municipal surveillance

Wastewater-based surveillance (WBS) has been an effective tool for monitoring and understanding potential SARS-CoV-2 transmission across small and large-scale communities. In this study at the University of Saskatchewan, the assessment of SARS-CoV-2 was done over eight months during the 2021-2022 academic year. Wastewater samples were collected using passive samplers that were deployed in domestic sewer lines near adjacent campus residences and extracted for viral RNA, followed by Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR). The results showed similar trends for SARS-CoV-2 detection frequencies and viral loads across university residences, the whole campus, and from related WBS at Saskatoon Wastewater Treatment Plant. The maximum daily detection frequency for seven dormitories considered was about 75 %, while maximum daily case numbers for the residences and campus-wide were about 11 and 75 people, respectively. In addition, self-reported rates of infection on campus peaked during similar time frames as increases in viral load were detected at the Saskatoon wastewater treatment plant. These similarities indicate the usefulness and cost-effectiveness of monitoring the spread of COVID-19 in small-scale communities using WBS.

Optimizing antibiotic use in culture-negative healthcare-associated infection with a 'stop' policy: a descriptive analytical study

BACKGROUND AND OBJECTIVES

Many sick neonates receive antibiotics for the clinical diagnosis of probable/possible sepsis. Reports suggest rampant antibiotic use in culture-negative sepsis. We introduced an antibiotic stop policy (ASP), by defining 'completed course duration of antibiotics' in the setting of culture-negative suspected healthcare-associated infection (HAI). Antibiotic overuse days (AOD) before antibiotic stop policy (BASP) and after antibiotic stop policy (AASP) were compared.

METHODS

This descriptive analytical study was conducted to measure the change in AOD after implementing ASP in culture-negative HAI. We also sought to evaluate situations in which antibiotic overuse is likely (lower gestation, ventilation, central lines) and safety of the ASP, measured as not having to restart antibiotics in the week following completed course.

RESULTS

A total of 126 neonates were initiated on a new antibiotic (started or changed) for suspected HAI. Of these, 43 were excluded. Patient days of 5175 and 5208 were analyzed in BASP and AASP, respectively. Implementation of an ASP reduced AOD (from 14.49 to 3.26 AOD per 1000 patient days; p value <0.01). Safety was ensured; the number of babies who had to be restarted on antibiotics within 1 week of stopping therapy was similar in both groups. All-cause mortality and relevant morbidities were comparable between groups.

CONCLUSIONS

A significant decrease in AOD after the introduction of an ASP was noted, in neonates with culture-negative suspected HAI. This difference was noted even in the most vulnerable extreme preterm babies and those requiring ventilation and central lines.

Endotracheal Aspirate and Ventilator-Associated Pneumonia in Neonates: Revisiting an Age-Old Debate

OBJECTIVES

To explore the utility of endotracheal aspirates (ETA) for analyzing microbiological yield, incidence, risk factors for VAP, and clinically relevant outcomes.

METHODS

Ventilated neonates suspected to have VAP were studied prospectively; they were classified as "VAP" or "No VAP" based on a predefined combination of clinical, radiological, and laboratory criteria. The microbiological yield from blood and ETA cultures was analyzed.

RESULTS

Of 165 neonates who were ventilated for > 48 h, 65 were suspected of having VAP. Thirty-six (22.9%) were classified as VAP. Microbiological agents could be identified in 31 cases (86.1%) by ETA/blood cultures. Acinetobacter sp was the common organism identified. Duration of ventilation, and a higher number of reintubations before suspicion of VAP were significant risk factors for VAP. Positive ETA culture was associated with a greater duration of oxygen therapy and ventilation days after suspicion of VAP.

CONCLUSIONS

The commonest culture yield from ETA in those suspected to have VAP was gram-negative bacilli. Duration of ventilation and reintubations were identified as significant risk factors for VAP. These are potentially modifiable factors. Positive ETA culture was associated with longer needs for respiratory supports. Negative ETA culture might encourage clinicians to stop antibiotics.

TRIAL REGISTRATION

Clinical Trials Registry of India No. CTRI/2019/03/017912,  www.ctri.nic.in.

Effect of Early Parent Participation Program on Physiological Stability in Preterm Infants: A Randomized Controlled Trial

OBJECTIVE

This research aimed to study the impact of early parent participation program (EPPP) for preterm infants in neonatal intensive care unit (NICU) on physiological instability, breastmilk feeding rates, and discharge timing.

STUDY DESIGN

Families of 147 infants born between 28 and 33 weeks' gestation were randomized at birth to EPPP group or conventional care (CC). Families in the EPPP group were trained soon after admission by using a structured education program and encouraged to spend more time with their baby. Soon after enrolment (day of life 1 to 2), they would sequentially participate in daily NICU care processes such as orogastric tube feeding, nesting, oil massages, diaper changes, and daily weight checks. Families in the CC group would undergo the same after their infant was off parenteral nutrition and respiratory support. Proportion of infants having physiological instability (significant apnea, feeding intolerance, or needing investigation for sepsis) in two groups was compared.

RESULTS

There was a significant reduction in the proportion of infants with physiological instability (feeding intolerance) in the EPPP group (relative risk = 0.70 [0.52-0.94], p = 0.016). Infants in EPPP group had a trend toward higher breastmilk feeding rates at discharge (66 vs. 51%, p = 0.076).

CONCLUSION

Very early parent participation was feasible in the NICU and led to decrease in physiological instability in preterm infants.

KEY POINTS

· Family-integrated care is beneficial; however, it is often started later in the NICU course.. · This trial showed that very early involvement of family in NICU care processes is feasible and safe.. · Structured parent participation started very early improves physiological stability in preterm infants (mainly tolerance to feeds)..

Incidence of Metabolic Bone Disease After Implementation of Bone Protective Nutritional Strategies: A Prospective Cohort Study

BACKGROUND

Metabolic bone disease (MBD) is a morbidity of multifactorial etiology with a high incidence in very preterm infants. We planned to study the incidence of MBD after implementation of bone health focussed nutritional strategy (BNS) in those <30 weeks gestation at birth.

METHODS

This prospective cohort study including preterm newborns (<30 weeks) who received nutrition that incorporated (a) Early initiation of intravenous potassium phosphate; (b) Early enteral supplementation with multicomponent human milk fortifier at enteral feed tolerance of 40 mL/kg/day feeds itself; and (c) Weekly phosphorus measurements with optimization of enteral intakes. Incidence of MBD at 4 weeks of postnatal age and beyond were analyzed. Other relevant safety and clinical outcomes were measured.

RESULTS

Of the 67 included neonates receiving BNS, 20.9% were classified as MBD. There was a low rate of hyper-phosphatemia (4.5%) and hyperkalemia (2.9%). Full enteral feeds were achieved by median (IQR) of 6 (5,7) postnatal days.

CONCLUSION

In preterm newborns (24-30 weeks) MBD incidence was 20.9% after BNS was implemented. Intravenous potassium salt of phosphorus and early use of HMF were safe and feasible.

Every treasured drop! Blood transfusion requirements in very preterm neonates after implementation of blood conservation strategies: an observational analytical study

BACKGROUND

Certain morbidities are inevitable in preterm infants; the challenge lies in minimizing them. Anemia of prematurity is multifactorial. Therapy largely depends on adult red blood cell transfusions (RBCT); which inherently, are not without problems. Most literature in this respect are retrospective or evaluate individual stratagems to reduce RBCT.

METHODS

This observational analytical study was planned to compare need for RBCT, before and after institution of blood conservation strategies (BCS). All those ≤30 weeks gestation at birth during two-time epochs were included (Before BCS: retrospective; After BCS: prospective). BCS constituted of delayed cord clamping (DCC), strict sampling indications, micro-sampling with point-of-care testing (MS-POCT) and adherence to RBCT thresholds.

RESULTS

Of 45 enrolled neonates in each group, proportion of those requiring even 1 RBCT was significantly reduced after BCS [51.1% vs. 26.7%, p = 0.02, OR 0.35, 95%CI (0.14, 0.84)]. Calculated cumulative blood volume losses (35.3 ml vs. 21.9 ml) and loss per kilogram birth weight (35.3 ml/kg vs. 20.12 ml/kg) were significantly lower after BCS (p = 0.0036). Need for &gt;1 RBCT, mean lowest Hb, mean maximum-hemoglobin drop, need for arterial lines were reduced. Adherence to RBCT thresholds were acceptably good in both time epochs. However, the compliance to DCC was low in both groups, identifying one area of focus with scope for massive improvement.

CONCLUSIONS

Need for RBCT transfusions largely attributable to reduced blood losses for lab analysis were reduced after BCS. Installation of in-house MS-POCT seemed to be the pivotal factor. Units that care for very preterm infants must make attempts to procure MS-POCT equipment.

Prevalence of Group B Streptococcus in pregnant women in Kerala and relation to neonatal outcomes: a prospective cross-sectional study

BACKGROUND AND OBJECTIVES

Early onset sepsis (EOS) in neonates is a scourge that contributes to morbidity and mortality. Prominent stakeholders recommend universal screening of antenatal women for Group B Streptococcus (GBS) and intrapartum antibiotic prophylaxis (IAP) for those who are carriers. However, there are controversies. Other guidelines allow region-specific protocols due to sociodemographic, geographical and ethnic differences. We planned to analyze the prevalence of GBS rectovaginal carriage at 36-37 weeks gestation and its effect on early neonatal status.

METHODS

This prospective multidisciplinary study (Obstetrics, Perinatology, Neonatology, Microbiology and Infectious diseases) was conducted in our tertiary care center between February 2020 and May 2021.

RESULTS

In our study group which included 966 mothers who delivered at the hospital, 4.8% of mothers who were screened by genito-rectal swabs were positive for GBS at 36-37 weeks gestation. All these mothers were given IAP as per protocol. Other organisms detected on screening mothers were Candida and Gram-negative bacteria. None of the neonates born to these mothers required any intensive care unit admission or therapy for systemic illness. There was no difference in clinically relevant outcomes between neonates who were born to GBS-positive mothers as compared to those born to negative screen result mothers.

CONCLUSIONS

GBS prevalence in our cohort was lower than most scientific reports. The neonates born to carrier mothers did not present with signs of early-onset sepsis.

Basic Life Support Guidance for Caregivers of NICU Graduates: Evaluation of Skill Transfer after Training

Background Intensivists indeed discharge neonatal intensive care unit (NICU) graduates after a period of physiological stability. There is, however, a real risk of life-threatening events at home. Survival after such episodes depends on time from arrest to initiation of basic life support (BLS). It is rational to train parents who would be first responders. We sought to measure objectively and prospectively, effect of BLS training on parents of NICU graduates on the psychomotor, cognitive, and affective domains of human learning.

Methods After face-to-face training sessions, proportion of home caregivers who obtained 100% marks on a pretested performance checklist for psychomotor skills of BLS on a mannequin were measured. Two other domains of learning and number of attempts required to obtain desirable results were also analyzed.

Results Median (interquartile range [IQR]) birth weight of the high-risk neonates was 1,050 g (930, 1570) and median gestational age was 29 (IQR 28, 33) weeks. More than 75% of parents had no prior exposure to BLS training. Among 46 trained caregivers, 80.4% achieved the desired score of 5 in the psychomotor performance checklist on the first attempt. A maximum of two attempts was required to reeducate and achieve score of 5 in the remaining caregivers. Forty-two (91.3%) caregivers obtained full marks on cognitive domain test. All caregivers responded positively toward affective domain questionnaire.

Conclusion It is possible to train parents in BLS measures and demonstrate their psychomotor skills on a mannequin effectively. No parents who were approached refused training or indicated anxiety in learning the skills required.

Cell type determination for cardiac differentiation occurs soon after seeding of human-induced pluripotent stem cells

BACKGROUND

Cardiac differentiation of human-induced pluripotent stem (hiPS) cells consistently produces a mixed population of cardiomyocytes and non-cardiac cell types, even when using well-characterized protocols. We sought to determine whether different cell types might result from intrinsic differences in hiPS cells prior to the onset of differentiation.

RESULTS

By associating individual differentiated cells that share a common hiPS cell precursor, we tested whether expression variability is predetermined from the hiPS cell state. In a single experiment, cells that shared a progenitor were more transcriptionally similar to each other than to other cells in the differentiated population. However, when the same hiPS cells were differentiated in parallel, we did not observe high transcriptional similarity across differentiations. Additionally, we found that substantial cell death occurs during differentiation in a manner that suggested all cells were equally likely to survive or die, suggesting that there is no intrinsic selection bias for cells descended from particular hiPS cell progenitors. We thus wondered how cells grow spatially during differentiation, so we labeled cells by expression of marker genes and found that cells expressing the same marker tended to occur in patches. Our results suggest that cell type determination across multiple cell types, once initiated, is maintained in a cell-autonomous manner for multiple divisions.

CONCLUSIONS

Altogether, our results show that while substantial heterogeneity exists in the initial hiPS cell population, it is not responsible for the variability observed in differentiated outcomes; instead, factors specifying the various cell types likely act during a window that begins shortly after the seeding of hiPS cells for differentiation.

Reliability enhancement of distribution networks with remote-controlled switches considering load growth under the effects of hidden failures and component aging

<abstract> <p>Over the last decade, automated distribution networks have grown in importance since traditional distribution networks are insufficiently intelligent to meet the growing need for reliable electricity supplies. Because the distribution network is the least reliable and the sole link between the utility and its customers, it is critical to improve its reliability. The remote-controlled switch (RCS) is a viable choice for boosting system reliability. It shortens the interruption period, which also minimizes the expected interruption cost and the amount of energy not served. Using the greedy search algorithm, this research expands the current reliability evaluation technique to include RCSs in distribution networks. The optimal location and numbers of RCSs have been evaluated with compromised cost. This study simultaneously takes into account the effects of load growth on system reliability indices, the impact of age on equipment failure rates and the hidden failure rate of fuses. The Roy Billinton test system's distribution network connected at bus 2 and bus 5 has been used to test the effectiveness of the suggested approach. The outcomes demonstrate that effective RCS deployment improves the radial distribution network's reliability indices significantly.</p> </abstract>

COVID-19 and tobacco cessation: lessons from India

OBJECTIVES

The Government of India prohibited the sale of tobacco products during the COVID-19 lockdown to prevent the spread of the SARS-CoV-2 virus. This study assessed the tobacco cessation behaviour and its predictors among adult tobacco users during the initial COVID-19 lockdown period in India.

METHODS

A cross-sectional study was conducted with 801 adult tobacco users (both smoking and smokeless tobacco) in two urban metropolitan cities of India over a 2-month period (July to August 2020). The study assessed complete tobacco cessation and quit attempts during the lockdown period. Logistic and negative binomial regression models were used to study the correlates of tobacco cessation and quit attempts, respectively.

RESULTS

In total, 90 (11.3%) tobacco users reported that they had quit using tobacco after the COVID-19 lockdown period. Overall, a median of two quit attempts (interquartile range 0-6) was made by tobacco users. Participants with good knowledge on the harmful effects of tobacco use and COVID-19 were significantly more likely to quit tobacco use (odds ratio [OR] 2.2; 95% confidence interval [CI] 1.2-4.0) and reported more quit attempts (incidence risk ratio 5.7; 95% CI 2.8-11.8) compared to those with poor knowledge. Participants who had access to tobacco products were less likely to quit tobacco use compared to those who had no access (OR 0.3; 95% CI 0.2-0.5].

CONCLUSIONS

Access restrictions and correct knowledge on the harmful effects of tobacco use and COVID-19 can play an important role in creating a conducive environment for tobacco cessation among users.

Postprandial endothelial dysfunction and CIMT after oral fat challenge in patients with type 2 diabetes mellitus with and without macrovascular disease - A preliminary study

BACKGROUND

Very few studies have reported on association of postprandial lipids and endothelial dysfunction among patients with diabetes. Whether endothelial dysfunction particularly postprandial FMD is worse in patients with T2DM with macrovascular disease compared to those without and whether this difference is related to postprandial hypertriglyceridemia (PPHTg) is unclear. Therefore, present study was aimed to assess the relationship between PPHTg and endothelial function in patients with T2DM with and without macrovascular disease.

METHOD

Endothelial dysfunction by FMD and CIMT were compared in patients with T2DM with and without macrovascular disease (n = 13 each group) and 13 age, sex and BMI matched healthy individuals after an oral fat challenge.

RESULTS

There was significant postprandial deterioration of FMD 4-hr after fat challenge in patients with diabetes (P < 0.001) as well as healthy individuals (P = 0.004). Patients with diabetes with macrovascular disease had significantly lower fasting (5.7 ± 6.1% vs. 22.7 ± 10.0% and vs. 24.7 ± 5.3%) as well as postprandial (4-hr) (3.1 ± 5.0% vs. 15.3 ± 8.1% and vs. 15.4 ± 5.7%) FMD compared to other two groups. Fasting, postprandial as well as change in FMD and CIMT in patients with diabetes correlated significantly with fasting as well as postprandial triglycerides with stronger correlation in those with macrovascular disease.

CONCLUSION

Study found significant endothelial dysfunction by FMD that shows substantial further deterioration postprandially following high fat meal in patients with diabetes with macrovascular disease compared to patients with diabetes without macrovascular disease and healthy individuals. Study also indicates that PPHTg is a contributor to endothelial dysfunction. However, more studies are required to corroborate these findings.

Iron Status of the Moderate and Late Preterm Infant: A Prospective Cohort Study

Guidelines on micronutrient supplementation in moderate to late preterm infants (MLP) are mostly extrapolated from those for smaller preterms, largely due to lack of systematic studies on physiological status in this special group of infants. Actual practices vary widely. We prospectively studied iron status by measurement of serum ferritin (SF) and haematological indices at 4 months corrected age in infants born between 32 and 36 weeks gestation (MLP), after they received 2 mg/kg/day oral iron from 6 weeks of postnatal age. Proportion of MLP having normal iron status (iron replete), i.e., neither iron deficiency (ID) nor iron excess was measured. ID anaemia, growth and development, risk factors for ID were also analysed. Of the 82 infants studied, 78% babies were late preterm. Seventy-four (90.3%) were iron replete (no deficiency or excess) at 4 months. High variability in SF levels (minimum of 9.8 to maximum of 252.2 μg/l) with median (IQR) of 57.45 μg/l (37.02-98.85) was noted in the entire cohort; and also within those who were iron deficient with median (IQR) of 17.50 μg/l (11.70-18.90). There was no difference in haematological indices of ID infants when compared to those with normal iron status. Inspite of oral iron supplementation with reasonable compliance, 8.5% MLP were iron deficient at 4 months corrected age. The high variability noted in SF levels could justify the need for monitoring iron status in this group of preterm infants. This could quintessentially aid individualization of iron supplementation advice.

952 In-Patient Trauma Surgery in COVID-19 Positive Patients Carries A Significantly Higher Mortality Risk When Compared to In-Patient Covid-19 Negative Patients and Day Case Trauma Patients

Introduction

Covid-19 caused many service changes, yet Trauma surgery continued throughout. We compare mortality rates from In-Patient (IP) and Day Case (DC) trauma patients and compare the mortality rates of patients who tested positive or negative for Covid-19.

Method

We reviewed all trauma admissions that underwent surgical intervention in both our IP and DC services during 31 days from March 23^rd 2020. We recorded their sex, age, operation, Covid-19 symptoms, Covid-19 test results and mortality. The findings were compared between the groups.

Results

In total 127 patients underwent surgery (66 IP; 61 DC). There were 6 deaths (9.1%) within the IP group and 0 deaths in the DC group (p = 0.006). In the IP group 8 patients (12.1%) tested positive for Covid-19 of which 4 died (50%) compared to the remaining 58 patients (87.9%) of which 2 (3.4%) died (p < 0.001). A higher mortality rate was observed in patients with symptoms but a negative Covid-19 test (6.7%) than patients in whom a test was never indicated (2.3%).

Conclusion

Covid-19 positive patients requiring in-patient admission for trauma surgery have a significantly higher mortality rate than both in-patient admissions that were Covid-19 negative or asymptomatic and patients that were treated with Day Case Trauma surgery.

866 A Lateral Approach Is More Likely to Be Successful Than A Posterior Approach for An Injection to Reach the Subacromial Space

Background

Subacromial injections are common for diagnosis and therapy of shoulder impingement secondary to subacromial bursitis. We evaluated the likelihood of a successful subacromial injection from both the posterior and lateral injection sites.

Method

We reviewed 100 MRI scans of the shoulder and recorded measurements in both the sagittal (representative of posterior injection) and coronal (representative of lateral injection) orientations. We compared these to the lengths of standard needles.

Multiple measurements were taken:

Results

Measuring along the angle of the acromion demonstrated shorter mean distances from the lateral injection site. The distance from skin to mid-point of the acromion) provided mean values of 51.4mm for posterior and 40.1mm for lateral. A standard 40mm (green) needle would reach the midpoint of the acromion in 58% of lateral measurements and 23% from posterior.

Conclusions

Injections are more likely to enter the subacromial space from a lateral rather than a posterior entry point.

384 Use of A Dry Swab During ACL Hamstring Tendon Graft Preparation May Lead to Decreased Graft Diameter at Implantation with Subsequent Rebound in Graft Diameter When Exposed to Haemarthrosis – A Porcine Tendon Study

Introduction

ACL reconstruction surgery commonly utilises a hamstring tendon graft. Grafts are normally covered with a wet swab prior to implantation. The aim of this study was to determine the variance in graft diameter when comparing the traditional wet swab to a dry swab.

Method

Flexor tendons from a selection of fresh pig trotters were isolated and prepared with a standard ACL graft preparation technique. Half of the grafts were covered with a wet swab; the other half were covered with a dry swab. Graft diameters were measured at 10-minute intervals. After 30 minutes the grafts were submerged in Hartmann’s solution to simulate the post-operative haemarthrosis, diameters were checked again after 1 hour in the solution.

Results

Use of a dry swab resulted in a 0.5mm greater reduction in diameter than the wet swab group. The dry swab group also showed an increase in diameter by 0.5mm when soaked in Hartmann’s solution, this was not seen in the wet swab group.

Conclusions

Using a dry swab produces a smaller graft diameter, this would allow smaller bone tunnels, retaining bone stock. The subsequent rebound in diameter when in solution may increase the press fit mechanism and facilitate improved integration into the bone tunnel.