De novo and salvage purine synthesis pathways across tissues and tumors.

Purine nucleotides are vital for RNA and DNA synthesis, signaling, metabolism, and energy homeostasis. To synthesize purines, cells use two principal routes: the de novo and salvage pathways. Traditionally, it is believed that proliferating cells predominantly rely on de novo synthesis, whereas differentiated tissues favor the salvage pathway. Unexpectedly, we find that adenine and inosine are the most effective circulating precursors for supplying purine nucleotides to tissues and tumors, while hypoxanthine is rapidly catabolized and poorly salvaged in vivo. Quantitative metabolic analysis demonstrates comparative contribution from de novo synthesis and salvage pathways in maintaining purine nucleotide pools in tumors. Notably, feeding mice nucleotides accelerates tumor growth, while inhibiting purine salvage slows down tumor progression, revealing a crucial role of the salvage pathway in tumor metabolism. These findings provide fundamental insights into how normal tissues and tumors maintain purine nucleotides and highlight the significance of purine salvage in cancer.

Rapid identification of SARS-CoV-2 strains via isothermal enzymatic recombinase amplification and nanopore sequencing.

Surveillance of the SARS-CoV-2 genome has become a crucial technique in the management of COVID-19, aiding the pandemic response and supporting effective public health interventions. Typically, whole-genomic sequencing is used along with PCR-based target enrichment techniques to identify SARS-CoV-2 variants, which is a complicated and time-consuming process that requires central laboratory facilities. Thus, there is an urgent need to develop rapid and cost-effective tools for precise on-site detection and identification of SARS-CoV-2 strains. In this study, we demonstrate the rapid diagnosis of COVID-19 and identification of SARS-CoV-2 variants by amplification and sequencing of the entire SARS-CoV-2 S gene using isothermal enzymatic recombinase amplification combined with the advanced Oxford nanopore sequencing technique. The entire procedure, from sampling to sequencing, takes less than 8 hours and can be performed with limited resources. The newly developed method has noteworthy implications for examining the transmission dynamics of the virus, detecting novel genetic variants, and assessing the effect of mutations on diagnostic approaches, antiviral treatments, and vaccines.

OrthoID: profiling dynamic proteomes through time and space using mutually orthogonal chemical tools.

Identifying proteins at organelle contact sites, such as mitochondria-associated endoplasmic reticulum membranes (MAM), is essential for understanding vital cellular processes, yet challenging due to their dynamic nature. Here we report "OrthoID", a proteomic method utilizing engineered enzymes, TurboID and APEX2, for the biotinylation (Bt) and adamantylation (Ad) of proteins close to the mitochondria and endoplasmic reticulum (ER), respectively, in conjunction with high-affinity binding pairs, streptavidin-biotin (SA-Bt) and cucurbit[7]uril-adamantane (CB[7]-Ad), for selective orthogonal enrichment of Bt- and Ad-labeled proteins. This approach effectively identifies protein candidates associated with the ER-mitochondria contact, including LRC59, whose roles at the contact site were-to the best of our knowledge-previously unknown, and tracks multiple protein sets undergoing structural and locational changes at MAM during mitophagy. These findings demonstrate that OrthoID could be a powerful proteomics tool for the identification and analysis of spatiotemporal proteins at organelle contact sites and revealing their dynamic behaviors in vital cellular processes.

Cerebral microdialysis demonstrates improvements in brain metabolism with cerebrospinal fluid diversion in spontaneous intracerebral hemorrhage.

Background: Cerebral microdialysis (CMD) is an FDA-approved multimodal invasive monitoring technique that provides local brain metabolism measurements through continuous interstitial brain fluid sampling at the bedside. The past applications in traumatic brain injury and subarachnoid hemorrhage show that acute brain injury (ABI) can lead to a metabolic crisis reflected by changes in cerebral glucose, pyruvate, and lactate. However, limited literature exists on CMD in spontaneous intracerebral hemorrhage (ICH). Case Description: A 45-year-old woman presented with a Glasgow Coma Scale of 8T and left frontal ICH with a 6 mm midline shift. She underwent craniotomy and ICH evacuation. Intraoperatively, CMD, brain tissue oxygenation (PbtO2), intracranial pressure (ICP), and cerebral blood flow (CBF) catheters were placed, targeted toward the peri-hematoma region. Postoperatively, ICP was normal; however, PbtO2, CBF, glucose, and lactate/ pyruvate ratio were abnormal. Due to concern for the metabolic crisis, poor examination, and hydrocephalus on computed tomography of the head (CTH), she underwent external ventricular drainage (EVD). Post-EVD, all parameters normalized (P < 0.05 on Student's t-test). Monitors were removed, and she was discharged to a nursing facility with a modified Rankin scale of 4. Conclusion: Here, we demonstrate the safe implementation of CMD in ICH and the use of CMD in tandem with PbtO2/ICP/CBF to guide treatment in ICH. Despite a normal ICP, numerous cerebral metabolic derangements existed and improved after cerebrospinal fluid diversion. A normal ICP may not reflect underlying metabolic-substrate demands of the brain during ABI. CMD and PbtO2/CBF monitoring augment traditional ICP monitoring in brain injury. Further prospective studies will be needed to understand further the interplay between ICP, PbtO2, CBF, and CMD values in ABI.

Ratiometric measurement of MAM Ca2+ dynamics using a modified CalfluxVTN.

Mitochondria-associated ER membrane (MAM) is a structure where these calcium-regulating organelles form close physical contact sites for efficient Ca2+ crosstalk. Despite the central importance of MAM Ca2+ dynamics in diverse biological processes, directly and specifically measuring Ca2+ concentrations inside MAM is technically challenging. Here, we develop MAM-Calflux, a MAM-specific BRET-based Ca2+ indicator. The successful application of the bimolecular fluorescence complementation (BiFC) concept highlights Ca2+-responsive BRET signals in MAM. The BiFC strategy imparts dual functionality as a Ca2+ indicator and quantitative structural marker specific for MAM. As a ratiometric Ca2+ indicator, MAM-Calflux estimates steady-state MAM Ca2+ levels. Finally, it enables the visualization of uneven intracellular distribution of MAM Ca2+ and the elucidation of abnormally accumulated MAM Ca2+ from the neurons of Parkinson's disease mouse model in both steady-state and stimulated conditions. Therefore, we propose that MAM-Calflux can be a versatile tool for ratiometrically measuring dynamic inter-organellar Ca2+ communication.

Payer shifting after expansions in access to private care among veterans.

OBJECTIVE: To investigate whether expanded access to Veterans Affairs (VA)-purchased care increased overall utilization or induced a shift from other payers to VA for emergency care among VA enrollees. DATA SOURCES AND STUDY SETTING: This study included all emergency department (ED) encounters in 2019 from hospitals in the state of New York. STUDY DESIGN: We conducted a difference-in-differences analysis comparing VA enrollees to the general population before and after the implementation of the Maintaining Internal Systems and Strengthening Integrated Outside Networks (MISSION) Act in June 2019. DATA COLLECTION/EXTRACTION METHODS: We included all ED visits with individuals aged 30 or older at the time of the encounter. Individuals were considered eligible for the policy change if they were enrolled with VA at the beginning of 2019. PRINCIPAL FINDINGS: Of the 5,577,199 ED visits in the sample, 4.9% (n = 253,799) were made by VA enrollees. Of these, 44.9% of visits were paid by Medicare, 32.8% occurred in VA facilities, and 7% were paid by private health insurance. There was a 6.4% (2.91 percentage points; std. error = 0.18; p < 0.01) decrease in the proportion of ED visits paid by Medicare among VA enrollees relative to the general population after the implementation of the MISSION Act in June 2019. This decrease was larger for ED visits with a subsequent inpatient admission (-8.4%; 4.87 percentage points; std. error = 0.33; p < 0.01). There was no statistically significant change in the total volume of ED visits (0.06%; std. error = 0.08; p = 0.45). CONCLUSIONS: Leveraging a novel dataset, we demonstrate that MISSION Act implementation coincided with a shift in the financing of non-VA ED visits from Medicare to VA without any increase in overall ED utilization. These findings have important implications for VA health care financing and delivery.

Instrument-free, visual and direct detection of porcine reproductive and respiratory syndrome viruses in resource-limited settings.

Porcine reproductive and respiratory syndrome (PRRS) caused by PRRS virus (PRRSV) is one of the most complicated and dangerous diseases in pigs with high mortality since it modulates the immune system of the lungs and has been closely associated with secondary infection of other lethal bacteria and viruses. The gold standard of molecular diagnosis for PRRSV, reverse transcription (RT)-PCR, is time-consuming, expensive and requires transportation of samples to a specialized laboratory. In this study, a direct colorimetric RT-loop-mediated isothermal amplification (RT-LAMP) method was developed to specifically and rapidly detect PRRSV. The RT-LAMP outcomes can be visualized by the naked eye after 45 min of incubation at 65˚C without any cross-reactivity recorded with the bacteria and other viruses tested. In particular, the mobile, non-instrumented, commercial pocket hand warmers were demonstrated to su-ccessfully provide constant temperature for consistent nucleic acid amplification throughout the RT-LAMP reactions. The limit of detection of the assay was defined as the genomic RNA concentration extracted from a known viral titer of 10-2.5 TCID50/ml. The direct use of clinical serum samples required a simple dilution to maintain the performance of the colorimetric RT-LAMP assay. Therefore, the direct colorimetric RT-LAMP assay developed is well-qualified for producing a ready-to-use kit for PRRSV diagnosis in the field. Keywords: porcine reproductive and respiratory syndrome; rapid testing; RT-LAMP; colorimetric; direct detection; instrument-free.

Evaluation of the Role of Self-cleaning Capacity on Marine Environmental Carrying Capacity: A Case of Ganh Rai Bay, Vietnam.

Economic activities are constantly increasing in the southern key economic region (SKER), especially in Ho Chi Minh City (HCMC), which leads to the influx of large amounts of wastewater from this region into Ganh Rai Bay (GRB). The problem of assessing the marine environmental carrying capacity (MECC) of coastal areas is urgent, and the role of self-cleaning must be elucidated. Four typical pollution parameters were selected: ammonium (NH4+), biological oxygen demand (BOD), phosphate (PO43-), and coliforms. The study aims to propose a framework to assess the impact of the role of self-cleaning on MECC and to apply the proposed framework to GRB as a case study. A series of models were used to simulate hydrodynamics, and an advection-diffusion model with an ecological parameter set was used for water quality modelling. The land-ocean interactions in the coastal zone model were used to calculate the GRB and East Sea retention time. Finally, a multiple linear regression model was used to clarify the relationship between the MECC and self-cleaning factors. Calculation results show that the self-cleaning factor increased the MECCAmmonium by 60.30% in the dry season and 22.75% in the wet season; similar to MECCBOD, MECCPhosphate increased by 5.26%, 0.21% (dry season), and 11.04%, 0.72% (wet season), respectively. MECCCColiforms in the dry season increased by 14.83%; in the wet season, MECCColiforms doubled. The results provide medium-and long-term solutions to improve the water quality of the GRB, especially the selection of activities that conserve the ecological system and improve the self-cleaning capacity of the bay.

Involvement of the inhibition of mitochondrial apoptotic, p53, NF-κB pathways and the activation of Nrf2/HO-1 pathway in the protective effects of curcumin against copper sulfate-induced nephrotoxicity in mice.

Chronic copper exposure could cause potential nephrotoxicity and effective therapy strategies are limited. This study investigated the protective effects of curcumin on copper sulfate (CuSO4)-induced renal damage in a mouse model and the underlying molecular mechanisms. Mice were administrated orally with CuSO4 (100 mg/kg per day) in combination with or without curcumin (50, 100 or 200 mg/kg per day, orally) for 28 days. Results showed that curcumin supplementation significantly reduce the Cu accumulation in the kidney tissues of mice and improved CuSO4-induced renal dysfunction. Furthermore, curcumin supplantation also significantly ameliorated Cu exposure-induced oxidative stress and tubular necrosis in the kidneys of mice. Moreover, compared to the CuSO4 alone group, curcumin supplementation at 200 mg/kg per day significantly decreased CuSO4-induced the expression of p53, Bax, IL-1ß, IL-6, and TNF-α proteins, levels of NF-κB mRNA, levels of caspases-9 and - 3 activities, and cell apoptosis, and significantly increased the levels of Nrf2 and HO-1 mRNAs in the kidney tissues. In conclusion, for the first time, our results reveal that curcumin could trigger the inhibition of oxidative stress, mitochondrial apoptotic, p53, and NF-κB pathways and the activation of Nrf2/HO-1 pathway to ameliorate Cu overload-induced nephrotoxicity in a mouse model. Our study highlights that curcumin supplementation may be a promising treatment strategy for treating copper overload-caused nephrotoxicity.

Concordance of functional MRI memory task and resting-state functional MRI connectivity used in surgical planning for pediatric temporal lobe epilepsy.

OBJECTIVE: Assessing memory is often critical in surgical evaluation, although difficult to assess in young children and in patients with variable task abilities. While obtaining interpretable data from task-based functional MRI (fMRI) measures is common in compliant and awake patients, it is not known whether functional connectivity MRI (fcMRI) data show equivalent results. If this were the case, it would have substantial clinical and research generalizability. To evaluate this possibility, the authors evaluated the concordance between fMRI and fcMRI data collected in a presurgical epilepsy cohort. METHODS: Task-based fMRI data for autobiographical memory tasks and resting-state fcMRI data were collected in patients with epilepsy evaluated at Seattle Children's Hospital between 2010 and 2017. To assess memory-related activation and laterality, signal change in task-based measures was computed as a percentage of the average blood oxygen level-dependent signal over the defined regions of interest. An fcMRI data analysis was performed using 1000 Functional Connectomes Project scripts based on Analysis of Functional NeuroImages and FSL (Functional Magnetic Resonance Imaging of the Brain Software Library) software packages. Lateralization indices (LIs) were estimated for activation and connectivity measures. The concordance between these two measures was evaluated using correlation and regression analysis. RESULTS: In this epilepsy cohort studied, the authors observed concordance between fMRI activation and fcMRI connectivity, with an LI regression coefficient of 0.470 (R2 = 0.221, p = 0.00076). CONCLUSIONS: Previously published studies have demonstrated fMRI and fcMRI overlap between measures of vision, attention, and language. In the authors' clinical sample, task-based measures of memory and analogous resting-state mapping were similarly linked in pattern and strength. These results support the use of fcMRI methods as a proxy for task-based memory performance in presurgical patients, perhaps including those who are more limited in their behavioral compliance. Future investigations to extend these results will be helpful to explore how the magnitudes of effect are associated with neuropsychological performance and postsurgical behavioral changes.

Purine nucleotide depletion prompts cell migration by stimulating the serine synthesis pathway.

Purine nucleotides are necessary for various biological processes related to cell proliferation. Despite their importance in DNA and RNA synthesis, cellular signaling, and energy-dependent reactions, the impact of changes in cellular purine levels on cell physiology remains poorly understood. Here, we find that purine depletion stimulates cell migration, despite effective reduction in cell proliferation. Blocking purine synthesis triggers a shunt of glycolytic carbon into the serine synthesis pathway, which is required for the induction of cell migration upon purine depletion. The stimulation of cell migration upon a reduction in intracellular purines required one-carbon metabolism downstream of de novo serine synthesis. Decreased purine abundance and the subsequent increase in serine synthesis triggers an epithelial-mesenchymal transition (EMT) and, in cancer models, promotes metastatic colonization. Thus, reducing the available pool of intracellular purines re-routes metabolic flux from glycolysis into de novo serine synthesis, a metabolic change that stimulates a program of cell migration.

Neurosurgery Lectures Benefit from a Flipped Class Approach.

BACKGROUND: In a flipped classroom, students learn lecture material before class and then participate in active learning during in-person sessions. This study examines preferences for flipped classroom activities during a neurosurgery presentation on traumatic brain injury. METHODS: Two hundred twenty-five third- and fourth-year medical students on their core neurology rotation watched an online podcast about traumatic brain injury before meeting for in-person, active learning activities with a neurological surgeon. Before and after the class, students were given rank-based surveys with an optional section for comments. The initial survey assessed preference for specific active learning activities, and the final survey assessed satisfaction with the experience. The students also answered an online 20-question postlecture test as part of the standard neurology class assessment. RESULTS: Every student scored over 90% on the postlecture test. Of the 81 students who answered the first survey, most students (83.95%) strongly preferred or preferred case scenarios with group discussion. The average Likert score for case scenario preference (4.37/5) was significantly higher than the score for all other activities (P < 0.05). Of the 207 students who answered the second survey, 80.19% of students reported that they would probably or definitely like to see more flipped classroom activities. CONCLUSIONS: Medical students highly preferred case scenarios because according to their comments, this method was relevant to real-life situations and led to higher information retention. This information suggests that the flipped classroom model for neurosurgical-based lectures is preferred, is beneficial, and should incorporate case scenarios. This methodology may also apply to neurosurgical residency training.

Assessing marine environmental carrying capacity in semi-enclosed coastal areas - Models and related databases.

Faced with the degradation of the marine environment, the Joint Group of Experts on the Scientific Aspects of Marine Pollution (GESEMP) first presented the concept of marine environmental carrying capacity (MECC) in 1986, which confirmed that there is a need to pay attention to physical, chemical, biological, and biochemical processes, thereby indirectly suggesting the need for a modelling approach. Although studies on MECC have been published, further research is necessary and must be complemented by a new approach. In this study, an integrated system called SECAMECC (Marine Environmental Carrying Capacity Semi Enclosed for Coastal Areas) for semi-enclosed bays is proposed. SECAMECC comprises database of seven data groups and four models: 3D hydrodynamic, ecological, retention time estimation, and MECC calculation. The proposed system has been applied to a specific semi-enclosed bay as a case study to determine the MECC seasonally. The carrying capacities of ammonium (NH4+), phosphate, total suspended solids (TSS), and biological oxygen demand were assessed in accordance with the baseline and forecast scenarios. The received results show that under the baseline, MECC no longer accepted PO43-; meanwhile, NH4+, TSS, and BOD5 exhibited the following values in the dry and wet season, respectively: 1134 and 3514 (t/m); 110,578 and 144,458 (t/m); and 17,072 and 44,348 (t/m). Owing to the hydrodynamic factors, the carrying capacity in the dry season is always greater than that in the wet season. Furthermore, the relationship between MECC and environmental standards, current water quality, and hydrodynamic factors was clarified.

Direct multiplex recombinase polymerase amplification for rapid detection of S taphylococcus aureus and P seudomonas aeruginosa in food.

Food and beverage poisoning is detrimental to people's health since it can lead to fever, stomachaches, and even death. To rapidly detect the presence of foodborne pathogens, conventional PCR assays are currently widely employed. Meanwhile, isothermal PCR methods, in which the amplification reactions take place at a low and constant temperature, have lately emerged as effective and alternative means for quickly identifying pathogens in low-resource settings. Staphylococcus aureus and Pseudomonas aeruginosa are two of the most concerning foodborne bacterial infections. In this work, an isothermal PCR assay based on the Recombinase Polymerase Amplification (RPA) method was developed to simultaneously detect S. aureus and P. aeruginosa with high sensitivity and specificity. The limit of detection for multiplex RPA was 10 and 30 fg/reaction of S. aureus and P. aeruginosa genomic DNA, respectively. Furthermore, the reaction time was reduced to only 25 minutes, with a low incubation temperature of 39°C. Multiplex RPA reactions, in particular, were successful in directly identifying as low as 1 and 5 CFU/reaction of S. aureus and P. aeruginosa cells, respectively, without the need for DNA genome extraction. Moreover, the multiplex RPA reliably detected the two foodborne bacteria in milk, fruit juice, and bottled water samples. In conclusion, the direct multiplex RPA reported in this work offers a quick, easy, sensitive, and effective alternative approach for detecting the presence of S. aureus and P. aeruginosa without the requirement of a pricey instrument or highly-trained personnel.

Efficacy evaluation of Chinese herbal medicine, VGH-BPH1, for patients with benign prostatic hyperplasia: A randomized, double-blind, placebo-controlled, and crossover study.

BACKGROUND: Benign prostatic hyperplasia (BPH) can affect quality of life and cause various complications. Previous studies have suggested that Chinese herbal medicine can alleviate symptoms in patients with BPH. This study aimed to investigate whether the Chinese herbal medicine prescription VGH-BPH1 can alleviate BPH symptoms when used as an add-on treatment. METHODS: In this crossover, randomized, double-blind, placebo-controlled trial, patients with BPH were randomly segregated into two groups: group A received VGH-BPH1, and group B received a placebo for 8 weeks. Subsequently, after a 2-week wash-out period, the two groups were switched to the opposite treatment for another 8 weeks. The International Prostate Symptoms Score and Aging Male Symptoms Score were adopted as the primary outcomes to assess improvement in BPH and patient quality of life. The secondary outcomes were the International Index of Erectile Function, Constitution Chinese Medicine Questionnaire, uroflowmetry results, and postvoid residual urine volume. RESULTS: VGH-BPH1 treatment significantly decreased the International Prostate Symptoms Score total score (p = 0.027); however, no significant difference was observed between the treatment and placebo groups. The Aging Male Symptoms Score "joint pain and muscular ache" score in the VGH-BPH1 group was significantly lower than that of the placebo group (p = 0.022). The "physical exhaustion" score also exhibited a decreasing trend when both groups were compared (p = 0.057). CONCLUSION: Although VGH-BPH1 treatment did not outperform the placebo in terms of improving BPH symptoms, it resulted in improvement in several quality of life indicators when relative to the placebo. Future research using a larger sample size with appropriate amendments to the protocol should be conducted to further investigate the effects of VGH-BPH1.

7-Year Experience with Automated Pupillometry and Direct Integration With the Hospital Electronic Medical Record.

INTRODUCTION: Manual pupillary assessments are an integral part of the neurologic evaluation in critically ill patients. Automated pupillometry provides reliable, consistent, and accurate measurement of the light response. We established a computer interface that allows for direct download of pupillometer information to our hospital electronic medical record (EMR). Here, we report our single-center experience. METHODS: An interface allowing direct download of pupillometer data to our EMR was developed. We then performed a prospective study using an electronic survey distributed to nurses that used pupillometers in 2015, 2018, and 2020 using a 5-point Likert-style format to evaluate the acceptance of this implementation. RESULTS: In 2015, 22 nurses were surveyed, with 50% of the respondents citing lack of pupillometers and 41% citing the labor intensity associated with data entry as the reason for the reluctance to use the pupillometer. The number of nurse responses in 2018 increased to 123, with 78% of nurses finding that the direct download to hospital EMR improved the efficiency of their neurologic exams. In 2020, 108 nurses responded with similar responses to those in 2018. We added 3 additional questions regarding utility of the pupillometer during the COVID-19 pandemic. Fifty-eight percent of nurses were reassured of the neurologic exam when using the pupillometer in lieu of a full exam to limit infectious exposure. CONCLUSIONS: This is the first report of the implementation of a direct interface to download pupillometer data to the EMR. The positive effect on nursing workflow and documentation of pupillary findings is discussed.

A Systematic Review and Meta-analysis Examining the Impact of Age on Perioperative Inflammatory Biomarkers.

BACKGROUND: Dysregulation of immune responses to surgical stress in older patients and those with frailty may manifest as differences in inflammatory biomarkers. We conducted a systematic review and meta-analysis to examine differences in perioperative inflammatory biomarkers between older and younger patients, and between patients with and without frailty. METHODS: MEDLINE, Embase, Cochrane, and CINAHL databases were searched (Inception to June 23, 2020). Observational or experimental studies reporting the perioperative level or activity of biomarkers in surgical patients stratified by age or frailty status were included. The primary outcome was inflammatory biomarkers (grouped by window of ascertainment: pre-op; post-op: <12 hours, 12-24 hours, 1-3 days, 3 days to 1 week, and >1 week). Quality assessment was conducted using the Newcastle-Ottawa Scale. Inverse-variance, random-effects meta-analysis was conducted. RESULTS: Forty-five studies (4263 patients) were included in the review, of which 36 were pooled for meta-analysis (28 noncardiac and 8 cardiac studies). Two studies investigated frailty as the exposure, while the remaining investigated age. In noncardiac studies, older patients had higher preoperative levels of interleukin (IL)-6 and C-reactive protein (CRP), lower preoperative levels of lymphocytes, and higher postoperative levels of IL-6 (<12 hours) and CRP (12-24 hours) than younger patients. In cardiac studies, older patients had higher preoperative levels of IL-6 and CRP and higher postoperative levels of IL-6 (<12 hours and >1 week). CONCLUSIONS: Our findings demonstrate a paucity of frailty-specific studies; however, the presence of age-associated differences in the perioperative inflammatory response is consistent with age-associated states of chronic systemic inflammation and immunosenescence. Additional studies assessing frailty-specific changes in the systemic biologic response to surgery may inform the development of targeted interventions.

Preoperative left ventricular end-systolic dimension predicts occurrence of aortic insufficiency following aortic valve preservation and repair surgery.

BACKGROUND: Preoperative left ventricular (LV) end-systolic dimension (LVESD) ≥5.0 cm is a class IIa indication for surgical intervention for aortic insufficiency (AI); however, the effect of LV dilatation on the longevity of the aortic valve (AV) has not yet been investigated. This study aimed to assess the impact of preoperative LV dimension on the long-term outcome of AV preservation surgery. METHODS: Between 2009 and 2019, 256 patients underwent AV preservation surgery at a single center. The median duration of follow-up was 5 years. The primary outcome was the development of >1+ AI at 6 years; secondary outcomes include long-term mortality, freedom from >2+ AI, and freedom from AV reoperation. Cox proportional hazard analysis was performed to identify predictors of AV deterioration. RESULTS: In-hospital mortality was 0.8%, and mean survival at 8 years was 85.5 ± 3.4%. Mean freedom from >1+ AI at 6 years was 71.1 ± 3.4%. Patients with preoperative indexed LVESD (LVESDi) ≥2.0 cm/m2 were at greater risk of developing >1+ AI at 6 years compared with patients with preoperative LVESDi of 1.5 to 1.9 cm/m2 and ≤1.4 cm/m2 (50.3 ± 0.1% vs 80.9 ± 0.1% vs 92.2 ± 0.1%, respectively; P < .01). On risk-adjusted multivariable analysis, preoperative LVESDi was an independent predictor for recurrence of >1+ AI (hazard ratio, 2.2; 95% confidence interval, 1.5-3.4). CONCLUSIONS: Preoperative LVESDi ≥2 cm/m2 is associated with increased risk of recurrent >1+ AI following AV preservation surgery. Further investigation of the appropriate operative threshold for AI may be warranted.

cdev: a ground-truth based measure to evaluate RNA-seq normalization performance.

Normalization of RNA-seq data has been an active area of research since the problem was first recognized a decade ago. Despite the active development of new normalizers, their performance measures have been given little attention. To evaluate normalizers, researchers have been relying on ad hoc measures, most of which are either qualitative, potentially biased, or easily confounded by parametric choices of downstream analysis. We propose a metric called condition-number based deviation, or cdev, to quantify normalization success. cdev measures how much an expression matrix differs from another. If a ground truth normalization is given, cdev can then be used to evaluate the performance of normalizers. To establish experimental ground truth, we compiled an extensive set of public RNA-seq assays with external spike-ins. This data collection, together with cdev, provides a valuable toolset for benchmarking new and existing normalization methods.