Major surgical conditions of childhood and their lifelong implications: comprehensive review.

BACKGROUND: In recent decades, the survival of children with congenital anomalies and paediatric cancer has improved dramatically such that there has been a steady shift towards understanding their lifelong health outcomes. Paediatric surgeons will actively manage such conditions in childhood and adolescence, however, adult surgeons must later care for these 'grown-ups' in adulthood. This article aims to highlight some of those rare disorders encountered by paediatric surgeons requiring long-term follow-up, their management in childhood and their survivorship impact, in order that the adult specialist may be better equipped with skills and knowledge to manage these patients into adulthood. METHODS: A comprehensive literature review was performed to identify relevant publications. Research studies, review articles and guidelines were sought, focusing on the paediatric management and long-term outcomes of surgical conditions of childhood. The article has been written for adult surgeon readership. RESULTS: This article describes the aforementioned conditions, their management in childhood and their lifelong implications, including: oesophageal atresia, tracheo-oesophageal fistula, malrotation, short bowel syndrome, duodenal atresia, gastroschisis, exomphalos, choledochal malformations, biliary atresia, Hirschsprung disease, anorectal malformations, congenital diaphragmatic hernia, congenital lung lesions and paediatric cancer. CONCLUSION: The increasing survivorship of children affected by surgical conditions will translate into a growing population of adults with lifelong conditions and specialist healthcare needs. The importance of transition from childhood to adulthood is becoming realized. It is hoped that this timely review will enthuse the readership to offer care for such vulnerable patients, and to collaborate with paediatric surgeons in providing successful and seamless transitional care.

Targeted Cyclo[8]pyrrole-Based NIR-II Photoacoustic Tomography Probe for Suppression of Orthotopic Pancreatic Tumor Growth and Intra-abdominal Metastases.

Pancreatic cancer is highly lethal. New diagnostic and treatment modalities are desperately needed. We report here that an expanded porphyrin, cyclo[8]pyrrole (CP), with a high extinction coefficient (89.16 L/g·cm) within the second near-infrared window (NIR-II), may be formulated with an αvß3-specific targeting peptide, cyclic-Arg-Gly-Asp (cRGD), to form cRGD-CP nanoparticles (cRGD-CPNPs) with promising NIR-II photothermal (PT) therapeutic and photoacoustic (PA) imaging properties. Studies with a ring-array PA tomography system, coupled with analysis of control nanoparticles lacking a targeting element (CPNPs), revealed that cRGD conjugation promoted the delivery of the NPs through abnormal vessels around the tumor to the solid tumor core. This proved true in both subcutaneous and orthotopic pancreatic tumor mice models, as confirmed by immunofluorescent studies. In combination with NIR-II laser photoirradiation, the cRGD-CPNPs provided near-baseline tumor growth inhibition through PTT both in vitro and in vivo. Notably, the combination of the present cRGD-CPNPs and photoirradiation was found to inhibit intra-abdominal metastases in an orthotopic pancreatic tumor mouse model. The cRGD-CPNPs also displayed good biosafety profiles, as inferred from PA tomography, blood analyses, and H&E staining. They thus appear promising for use in combined PA imaging and PT therapeutic treatment of pancreatic cancer.

Relief of tumor hypoxia using a nanoenzyme amplifies NIR-II photoacoustic-guided photothermal therapy.

Hypoxia is a critical tumor microenvironment (TME) component. It significantly impacts tumor growth and metastasis and is known to be a major obstacle for cancer therapy. Integrating hypoxia modulation with imaging-based monitoring represents a promising strategy that holds the potential for enhancing tumor theranostics. Herein, a kind of nanoenzyme Prussian blue (PB) is synthesized as a metal-organic framework (MOF) to load the second near-infrared (NIR-II) small molecule dye IR1061, which could catalyze hydrogen peroxide to produce oxygen and provide a photothermal conversion element for photoacoustic imaging (PAI) and photothermal therapy (PTT). To enhance stability and biocompatibility, silica was used as a coating for an integrated nanoplatform (SPI). SPI was found to relieve the hypoxic nature of the TME effectively, thus suppressing tumor cell migration and downregulating the expression of heat shock protein 70 (HSP70), both of which led to an amplified NIR-II PTT effect in vitro and in vivo, guided by the NIR-II PAI. Furthermore, label-free multi-spectral PAI permitted the real-time evaluation of SPI as a putative tumor treatment. A clinical histological analysis confirmed the amplified treatment effect. Hence, SPI combined with PAI could offer a new approach for tumor diagnosing, treating, and monitoring.

Internet Health Resources on Nocturnal Enuresis: A Readability, Quality, and Accuracy Analysis.

INTRODUCTION: Nocturnal enuresis is a common yet quality-of-life-limiting pediatric condition. There is an increasing trend for parents to obtain information on the disease's nature and treatment options via the internet. However, the quality of health-related information on the internet varies greatly and is largely uncontrolled and unregulated. With this study, a readability, quality, and accuracy evaluation of the health information regarding nocturnal enuresis is carried out. MATERIALS AND METHODS: A questionnaire was administered to parents and patients with nocturnal enuresis to determine their use of the internet to research their condition. The most common search terms were determined, and the first 30 websites returned by the most popular search engines were used to assess the quality of information about nocturnal enuresis. Each site was categorized by type and assessed for readability using the Gunning fog score, Simple Measure of Gobbledygook (SMOG) index, and Dale-Chall score; for quality using the DISCERN score; and for accuracy by comparison to the International Children's Continence Society guidelines by three experienced pediatric urologists and nephrologists. RESULTS: A total of 30 websites were assessed and classified into five categories: professional (n = 13), nonprofit (n = 8), commercial (n = 4), government (n = 3), and other (n = 2). The information was considered difficult for the public to comprehend, with mean Gunning fog, SMOG index, and Dale-Chall scores of 12.1 ± 4.3, 14.1 ± 4.3, and 8.1 ± 1.3, respectively. The mean summed DISCERN score was 41 ± 11.6 out of 75. Only seven (23%) websites were considered of good quality (DISCERN score > 50). The mean accuracy score of the websites was 3.2 ± 0.6 out of 5. Commercial websites were of the poorest quality and accuracy. Websites generally scored well in providing their aims and identifying treatment benefits and options, while they lacked references and information regarding treatment risks and mechanisms. CONCLUSION: Online information about nocturnal enuresis exists for parents; however, most websites are of suboptimal quality, readability, and accuracy. Pediatric surgeons should be aware of parents' health-information-seeking behavior and be proactive in guiding parents to identify high-quality resources.

Congenital lung malformations.

Congenital lung malformations (CLMs) are rare developmental anomalies of the lung, including congenital pulmonary airway malformations (CPAM), bronchopulmonary sequestration, congenital lobar overinflation, bronchogenic cyst and isolated congenital bronchial atresia. CLMs occur in 4 out of 10,000 live births. Postnatal presentation ranges from an asymptomatic infant to respiratory failure. CLMs are typically diagnosed with antenatal ultrasonography and confirmed by chest CT angiography in the first few months of life. Although surgical treatment is the gold standard for symptomatic CLMs, a consensus on asymptomatic cases has not been reached. Resection, either thoracoscopically or through thoracotomy, minimizes the risk of local morbidity, including recurrent infections and pneumothorax, and avoids the risk of malignancies that have been associated with CPAM, bronchopulmonary sequestration and bronchogenic cyst. However, some surgeons suggest expectant management as the incidence of adverse outcomes, including malignancy, remains unknown. In either case, a planned follow-up and a proper transition to adult care are needed. The biological mechanisms through which some CLMs may trigger malignant transformation are under investigation. KRAS has already been confirmed to be somatically mutated in CPAM and other genetic susceptibilities linked to tumour development have been explored. By summarizing current progress in CLM diagnosis, management and molecular understanding we hope to highlight open questions that require urgent attention.

Long-term follow-up of biliary atresia using liver transient elastography.

OBJECTIVE: Liver transient elastography (TE) using FibroScan® has gained popularity as a non-invasive technique to assess hepatic fibrosis by measuring liver stiffness. This study focused on biliary atresia patients post Kasai operation for more than 10 years to prospectively correlate the hepatic fibrosis score to the biochemical changes of liver fibrosis and clinical development of portal hypertensive complications. METHODS: TE was performed in 37 patients who had biliary atresia post Kasai operation done at median age of 60 days. Biochemical indices of liver fibrosis including aspartate aminotransferase/platelet ratio index (APRI) and Fibrosis-4 (FIB-4) score based on age, platelet count, alanine aminotransferase and aspartate aminotransferase level were calculated at the time of TE. Platelet count, spleen size, varices, ascites and hepatic encephalopathy were evaluated as clinical markers of portal hypertension. RESULTS: There were 22 female and 15 male with TE done at median age of 17.0 years. Median FibroScan® fibrosis score was 11.4. Fibrosis score of 6.8 kilopascal (kPa) was taken as the upper reference limit of normal. Nine patients (24%) had normal fibrosis score. Score above or equal to 6.8 kPa was significantly associated with lower platelet level (p = 0.001), higher INR (p = 0.043), higher APRI (p = 0.021), higher FIB-4 score (p = 0.013), and larger splenic diameter (p = 0.004). Higher FibroScan® fibrosis score was also significantly associated with portal hypertensive complications (p = 0.001). CONCLUSIONS: The FibroScan® fibrosis score correlated well with the biochemical changes of liver fibrosis and development of portal hypertensive complications clinically. Screening of portal hypertensive complications such as varices is recommended for patients with raised fibrosis score upon long-term follow-up. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Generalized and scalable trajectory inference in single-cell omics data with VIA.

Inferring cellular trajectories using a variety of omic data is a critical task in single-cell data science. However, accurate prediction of cell fates, and thereby biologically meaningful discovery, is challenged by the sheer size of single-cell data, the diversity of omic data types, and the complexity of their topologies. We present VIA, a scalable trajectory inference algorithm that overcomes these limitations by using lazy-teleporting random walks to accurately reconstruct complex cellular trajectories beyond tree-like pathways (e.g., cyclic or disconnected structures). We show that VIA robustly and efficiently unravels the fine-grained sub-trajectories in a 1.3-million-cell transcriptomic mouse atlas without losing the global connectivity at such a high cell count. We further apply VIA to discovering elusive lineages and less populous cell fates missed by other methods across a variety of data types, including single-cell proteomic, epigenomic, multi-omics datasets, and a new in-house single-cell morphological dataset.

Early Development of Colonic Adenocarcinoma With Minimal Polyposis in a Young Child With Metastatic Hepatoblastoma and Germline APC Mutation.

Germline adenomatous polyposis coli (APC) gene mutation is a cancer-predisposing condition commonly presenting as familial adenomatous polyposis. We describe a patient first diagnosed at the age of 3 years with metastatic hepatoblastoma. With a positive family history, germline testing confirmed maternally inherited APC mutation (p.Thr899Ansfs*13). The patient was subsequently diagnosed at 8 years with colonic adenocarcinoma in the absence of macroscopic polyposis. Total colectomy with adjuvant chemotherapy was delivered and the patient remained disease-free for 5 years since the second diagnosis. This report demonstrates the importance of considering germline APC mutation in children with hepatoblastoma, who may benefit from the early institution of colonoscopic surveillance.

Comparison of thoracoscopy vs. thoracotomy on musculoskeletal outcomes of children with congenital pulmonary airway malformation (CPAM).

BACKGROUND: It has been postulated that video-assisted thoracoscopic surgery (VATS) is superior than conventional thoracotomy for resection of congenital pulmonary airway malformation (CPAM) in terms of shorter hospital length of stay, reduced post-operative complication and better long-term pulmonary outcome. However, there is limited available data concerning the effect of VATS and conventional thoracotomy on musculoskeletal aspects in patients with CPAM. This study aims to compare the long-term effects of both surgical techniques on musculoskeletal outcomes in this group of patients. METHODS: Thirty-five patients with mean age of 11.38 years old who underwent VATS or conventional thoracotomy for CPAM resection were recruited in this study. The mean follow-up time was 10.42 years (5.48 to 17.71 years). Musculoskeletal examination included screening of musculoskeletal deformities (elevation of shoulder, asymmetry of nipple level, breast/ pectoral muscle maldevelopment, winging of scapula, scoliosis), measurement of bilateral chest wall in relation to anatomical parameter, and testing of shoulder range of motion and power. RESULTS: The prevalence of winged scapula was significantly lower in patients who underwent VATS than thoracotomy (13% vs 58%, p = 0.008). There is also a smaller reduction in operated-side chest wall vertical distance in VATS patients (0.982 vs 0.956, p = 0.058). There were no significant difference in prevalence of other musculoskeletal deformities, other chest wall measurements, shoulder range of motion and power between two groups. CONCLUSION: Thoracoscopy decreases the incidence of scapular winging but has no effect on effect on other musculoskeletal deformities.

Thoracoscopic removal of a displaced thoracoamniotic shunt in a newborn with antenatal pleural effusion-a case report.

Thoracoamniotic shunt has been considered as a treatment for antenatal pleural effusion and complication is rare. In majority of cases, the shunt can be removed uneventfully. In this article, we reported a rare complication of shunt migration resulting in the need of thoracoscopic removal at newborn period. The patient born at 39+3 weeks of gestation suffered from antenatal chylothorax detected at 28 weeks and was managed by intrauterine thoracoamniotic shunt insertion. This was complicated by shunt displacement, which caused respiratory distress after birth requiring ventilatory support and progressive pleural effusion in this patient. To prevent further neonatal compromise, thoracoscopic removal of the retained shunt was done on day 7 of life followed by post-op chest drain insertion. Post-op condition was stable with resolution of respiratory distress, and the patient was discharge on post-op day 16. We would like to remind clinicians about this potential complication of thoracoaminotic shunt, which can pose a potential risk of severe neonatal compromise, and that it can be managed by minimal invasive surgery even in the newborn period.

Deep-learning-assisted biophysical imaging cytometry at massive throughput delineates cell population heterogeneity.

The association of the intrinsic optical and biophysical properties of cells to homeostasis and pathogenesis has long been acknowledged. Defining these label-free cellular features obviates the need for costly and time-consuming labelling protocols that perturb the living cells. However, wide-ranging applicability of such label-free cell-based assays requires sufficient throughput, statistical power and sensitivity that are unattainable with current technologies. To close this gap, we present a large-scale, integrative imaging flow cytometry platform and strategy that allows hierarchical analysis of intrinsic morphological descriptors of single-cell optical and mass density within a population of millions of cells. The optofluidic cytometry system also enables the synchronous single-cell acquisition of and correlation with fluorescently labeled biochemical markers. Combined with deep neural network and transfer learning, this massive single-cell profiling strategy demonstrates the label-free power to delineate the biophysical signatures of the cancer subtypes, to detect rare populations of cells in the heterogeneous samples (10-5), and to assess the efficacy of targeted therapeutics. This technique could spearhead the development of optofluidic imaging cell-based assays that stratify the underlying physiological and pathological processes based on the information-rich biophysical cellular phenotypes.

Haematological and immunological data of Chinese children infected with coronavirus disease 2019.

Haematological and immunological data of children with COVID-19 infection is lacking. Between 21st January and 20th March 2020, 244 children who were confirmed to have COVID-19 infection and admitted to the Wuhan Children's Hospital, China were retrospectively reviewed. 193 children were considered as symptomatic, which was defined as having either the presence of clinical symptoms or the presence of CT thorax abnormalities. Their haematological and immunological profiles, including complete blood counts, lymphocyte subsets (T, B and NK cell counts), immunoglobulin (Ig) profiles (IgG, IgA and IgM) and cytokine profiles were analysed and compared between the symptomatic and asymptomatic groups. The median values and the interquartile ranges were calculated. Comparison was made using the Mann-Whitney U test. Children with symptomatic COVID-19 infection had significantly lower haemoglobin levels, but higher absolute lymphocyte and monocyte counts, IgG and IgA levels, as well as interleukin 6 (IL-6), IL-10, tumour necrosis factor alpha and interferon gamma levels. The obtained data will be utilized for further studies in comparing children and adults with COVID-19 infections in other parts of the world and with different severity .

Delayed application of silver nanoparticles reveals the role of early inflammation in burn wound healing.

Burn injury is common, and antimicrobial agents are often applied immediately to prevent wound infection and excessive inflammatory response. Although inflammation is essential for clearing bacteria and creating an environment conducive to the healing process, it is unclear what time-frame inflammation should be present for optimal wound healing. This study critically investigated the role of early inflammation in burn wound healing, and also revealed the molecular mechanisms underlying the pro-healing effects of silver nanoparticles (AgNPs). We created a burn injury mouse model using wild-type and Smad3-/- mice, which were topically treated with AgNPs at different post-burn days, and examined the healing processes of the various groups. We also delineated the molecular pathways underlying the anti-inflammation and pro-healing effects of AgNPs by morphological and histological analysis, immuno-histochemistry, and western blotting. Our results showed that (1) AgNPs regulated pro-inflammatory cytokine IL-6 production of keratinocytes and neutrophils infiltration through KGF-2/p38 signaling pathway, (2) Topical AgNPs treatment immediately after burn injury significantly supressed early inflammation but resulted in delayed healing, (3) A short delay in AgNPs application (post-burn day 3 in our model) allowed early inflammation in a controlled manner, and led to optimal burn wound healing. Thus, our current study showed that some degree of early inflammation was beneficial, but prolonged inflammation was detrimental for burn wound healing. Further evaluation and clinical translation of this finding is warranted.

Feedback from artificial intelligence improved the learning of junior endoscopists on histology prediction of gastric lesions.

Background and study aims Artificial intelligence (AI)-assisted image classification has been shown to have high accuracy on endoscopic diagnosis. We evaluated the potential effects of use of an AI-assisted image classifier on training of junior endoscopists for histological prediction of gastric lesions. Methods An AI image classifier was built on a convolutional neural network with five convolutional layers and three fully connected layers A Resnet backbone was trained by 2,000 non-magnified endoscopic gastric images. The independent validation set consisted of another 1,000 endoscopic images from 100 gastric lesions. The first part of the validation set was reviewed by six junior endoscopists and the prediction of AI was then disclosed to three of them (Group A) while the remaining three (Group B) were not provided this information. All endoscopists reviewed the second part of the validation set independently. Results The overall accuracy of AI was 91.0 % (95 % CI: 89.2-92.7 %) with 97.1 % sensitivity (95 % CI: 95.6-98.7%), 85.9 % specificity (95 % CI: 83.0-88.4 %) and 0.91 area under the ROC (AUROC) (95 % CI: 0.89-0.93). AI was superior to all junior endoscopists in accuracy and AUROC in both validation sets. The performance of Group A endoscopists but not Group B endoscopists improved on the second validation set (accuracy 69.3 % to 74.7 %; P  = 0.003). Conclusion The trained AI image classifier can accurately predict presence of neoplastic component of gastric lesions. Feedback from the AI image classifier can also hasten the learning curve of junior endoscopists in predicting histology of gastric lesions.

Short-term and long-term outcomes after Roux-en-Y hepaticojejunostomy versus hepaticoduodenostomy following laparoscopic excision of choledochal cyst in children.

BACKGROUND: Choledochal cysts are congenital dilations of the biliary tree. Complete cyst excision and biliary-enteric reconstruction have been the standard operations. In our center, more than 95% of choledochal cyst excision is now performed laparoscopically. Majority of current studies describe laparoscopic-assisted reconstruction using Roux-en-Y hepaticojejunostomy (HJ). However, only a few have studied laparoscopic hepaticoduodenostomy (HD) as an alternative method of biliary-enteric reconstruction. In this study, we focused on comparing longer-term outcomes between laparoscopic HJ and HD reconstruction following choledochal cyst excision. METHODS: We performed retrospective analysis of 54 children who had undergone laparoscopic choledochal cyst excision and biliary-enteric reconstruction between October 2004 and April 2018. Short-term outcomes including operative time, complications such as anastomotic leakage and bleeding, and hospital stays were included. Long-term outcomes including contrast reflux into biliary tree, cholangitis, anastomotic strictures, and need of reoperation were analyzed. RESULTS: Of the 54 patients, 21 of them underwent laparoscopic HD and 33 underwent laparoscopic Roux-en-Y HJ anastomosis reconstruction. There were no significant differences in gestation, gender, age at operation, antenatal diagnosis, and Todani type of choledochal cyst between HD and HJ group. Operative time was significantly shortened in HD group (p = 0.001). Median time to enteral feeding was 3 days in both groups. Median intensive care unit (p = 0.001) and hospital stay (p = 0.019) were significantly shorter in HD group. There was no perioperative mortality. There was no significant difference in anastomotic leakage requiring reoperation (p = 0.743). There were no significant differences in long-term outcomes including anastomotic stricture (p = 0.097), cholangitis (p = 0.061), symptoms of recurrent abdominal pain or gastritis (p = 0.071), or need of reoperation (p = 0.326). All patients had normal postoperative serum bilirubin level. CONCLUSIONS: Laparoscopic excision of choledochal cyst with HD reconstruction is safe and feasible with better short-term outcomes and comparable long-term outcomes compared to Roux-en-Y HJ reconstruction.

Determining the optimal timing of liver transplant for pediatric patients after Kasai portoenterostomy based on disease severity scores.

BACKGROUND: The objective of this study was to determine the most optimal timing of liver transplant (LT) for post-Kasai portoenterostomy (KPE) patients based on disease severity scores. METHODS: This was a retrospective study and the clinical data of all LT recipients aged <18 years (n = 89) with a history of KPE were analyzed. They were divided into three groups according to their PELD/MELD scores at the time of LT (A: <15; B: 15-25; C: >25). The effects of LT on the clinical outcomes and hospitalization status were analyzed. RESULTS: There were 33, 34 and 22 patients in group A, B and C, respectively. There was no significant difference in 3-year graft survival rate between the three groups but group C patients had the highest incidence of vascular or biliary complications (p = 0.022). Group C patients had a significantly lower hospital admission frequency (p = 0.036) and shorter hospital stay (p = 0.041) after LT when compared with their pre-LT status and with non-LT patients with similar disease severity scores. On the other hand, the hospitalization frequency and duration were similar in patients with the lowest disease severity score (group A) before, after and without LT. CONCLUSIONS: The benefit of LT was less obvious when the disease severity score is <15. A high complication rate was reported when LT was performed at a score > 25. Donor availability, the patient's general condition and parental wish should be considered during individual assessment. TYPE OF STUDY: Clinical research paper. LEVEL OF EVIDENCE: Level III.

Endoscopic prediction of deeply submucosal invasive carcinoma with use of artificial intelligence.

Background and study aims We evaluated use of artificial intelligence (AI) assisted image classifier in determining the feasibility of curative endoscopic resection of large colonic lesion based on non-magnified endoscopic images Methods AI image classifier was trained by 8,000 endoscopic images of large (≥ 2 cm) colonic lesions. The independent validation set consisted of 567 endoscopic images from 76 colonic lesions. Histology of the resected specimens was used as gold standard. Curative endoscopic resection was defined as histology no more advanced than well-differentiated adenocarcinoma, ≤ 1 mm submucosal invasion and without lymphovascular invasion, whereas non-curative resection was defined as any lesion that could not meet the above requirements. Performance of the trained AI image classifier was compared with that of endoscopists. Results In predicting endoscopic curative resection, AI had an overall accuracy of 85.5 %. Images from narrow band imaging (NBI) had significantly higher accuracy (94.3 % vs 76.0 %; P  < 0.00001) and area under the ROC curve (AUROC) (0.934 vs 0.758; P  = 0.002) than images from white light imaging (WLI). AI was superior to two junior endoscopists in terms of accuracy (85.5 % vs 61.9 % or 82.0 %, P  < 0.05), AUROC (0.837 vs 0.638 or 0.717, P  < 0.05) and confidence level (90.1 % vs 83.7 % or 78.3 %, P  < 0.05). However, there was no statistical difference in accuracy and AUROC between AI and a senior endoscopist. Conclusions The trained AI image classifier based on non-magnified images can accurately predict probability of curative resection of large colonic lesions and is better than junior endoscopists. NBI images have better accuracy than WLI for AI prediction.

Quantitative Phase Imaging Flow Cytometry for Ultra-Large-Scale Single-Cell Biophysical Phenotyping.

Cellular biophysical properties are the effective label-free phenotypes indicative of differences in cell types, states, and functions. However, current biophysical phenotyping methods largely lack the throughput and specificity required in the majority of cell-based assays that involve large-scale single-cell characterization for inquiring the inherently complex heterogeneity in many biological systems. Further confounded by the lack of reported robust reproducibility and quality control, widespread adoption of single-cell biophysical phenotyping in mainstream cytometry remains elusive. To address this challenge, here we present a label-free imaging flow cytometer built upon a recently developed ultrafast quantitative phase imaging (QPI) technique, coined multi-ATOM, that enables label-free single-cell QPI, from which a multitude of subcellularly resolvable biophysical phenotypes can be parametrized, at an experimentally recorded throughput of >10,000 cells/s-a capability that is otherwise inaccessible in current QPI. With the aim to translate multi-ATOM into mainstream cytometry, we report robust system calibration and validation (from image acquisition to phenotyping reproducibility) and thus demonstrate its ability to establish high-dimensional single-cell biophysical phenotypic profiles at ultra-large-scale (>1,000,000 cells). Such a combination of throughput and content offers sufficiently high label-free statistical power to classify multiple human leukemic cell types at high accuracy (~92-97%). This system could substantiate the significance of high-throughput QPI flow cytometry in enabling next frontier in large-scale image-derived single-cell analysis applied in biological discovery and cost-effective clinical diagnostics. © 2019 International Society for Advancement of Cytometry.

Multi-ATOM: Ultrahigh-throughput single-cell quantitative phase imaging with subcellular resolution.

A growing body of evidence has substantiated the significance of quantitative phase imaging (QPI) in enabling cost-effective and label-free cellular assays, which provides useful insights into understanding the biophysical properties of cells and their roles in cellular functions. However, available QPI modalities are limited by the loss of imaging resolution at high throughput and thus run short of sufficient statistical power at the single-cell precision to define cell identities in a large and heterogeneous population of cells-hindering their utility in mainstream biomedicine and biology. Here we present a new QPI modality, coined multiplexed asymmetric-detection time-stretch optical microscopy (multi-ATOM) that captures and processes quantitative label-free single-cell images at ultrahigh throughput without compromising subcellular resolution. We show that multi-ATOM, based upon ultrafast phase-gradient encoding, outperforms state-of-the-art QPI in permitting robust phase retrieval at a QPI throughput of >10 000 cell/sec, bypassing the need for interferometry which inevitably compromises QPI quality under ultrafast operation. We employ multi-ATOM for large-scale, label-free, multivariate, cell-type classification (e.g. breast cancer subtypes, and leukemic cells vs peripheral blood mononuclear cells) at high accuracy (>94%). Our results suggest that multi-ATOM could empower new strategies in large-scale biophysical single-cell analysis with applications in biology and enriching disease diagnostics.