Deep Cytometry: Deep learning with Real-time Inference in Cell Sorting and Flow Cytometry

Deep learning has achieved spectacular performance in image and speech recognition and synthesis. It outperforms other machine learning algorithms in problems where large amounts of data are available. In the area of measurement technology, instruments based on the photonic time stretch have established record real-time measurement throughput in spectroscopy, optical coherence tomography, and imaging flow cytometry. These extreme-throughput instruments generate approximately 1 Tbit/s of continuous measurement data and have led to the discovery of rare phenomena in nonlinear and complex systems as well as new types of biomedical instruments. Owing to the abundance of data they generate, time-stretch instruments are a natural fit to deep learning classification. Previously we had shown that high-throughput label-free cell classification with high accuracy can be achieved through a combination of time-stretch microscopy, image processing and feature extraction, followed by deep learning for finding cancer cells in the blood. Such a technology holds promise for early detection of primary cancer or metastasis. Here we describe a new deep learning pipeline, which entirely avoids the slow and computationally costly signal processing and feature extraction steps by a convolutional neural network that directly operates on the measured signals. The improvement in computational efficiency enables low-latency inference and makes this pipeline suitable for cell sorting via deep learning. Our neural network takes less than a few milliseconds to classify the cells, fast enough to provide a decision to a cell sorter for real-time separation of individual target cells. We demonstrate the applicability of our new method in the classification of OT-II white blood cells and SW-480 epithelial cancer cells with more than 95% accuracy in a label-free fashion

Effective inhibition of HCMV UL49 gene expression and viral replication by oligonucleotide external guide sequences and RNase P

Abstract Background Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus that typically causes asymptomatic infections in healthy individuals but may lead to serious complications in newborns and immunodeficient individuals. The emergence of drug-resistant strains of HCMV has posed a need for the development of new drugs and treatment strategies. Antisense molecules are promising gene-targeting agents for specific regulation of gene expression. External guide sequences (EGSs) are oligonucleotides that consist of a sequence complementary to a target mRNA and recruit intracellular RNase P for specific degradation of the target RNA. The UL49-deletion BAC of HCMV was significantly defective in growth in human foreskin fibroblasts. Therefore, UL49 gene may serve as a potential target for novel drug development to combat HCMV infection. In this study, DNA-based EGS molecules were synthesized to target the UL49 mRNA of human cytomegalovirus (HCMV). Results By cleavage activity assessing in vitro, the EGS aimed to the cleavage site 324 nt downstream from the translational initiation codon of UL49 mRNA (i.e. EGS324) was confirmed be efficient to direct human RNase P to cleave the target mRNA sequence. When EGS324 was exogenously administered into HCMV-infected human foreskin fibroblasts (HFFs), a significant reduction of ~76% in the mRNA and ~80% in the protein expression of UL49 gene, comparing with the cells transfected with control EGSs. Furthermore, a reduction of about 330-fold in HCMV growth were observed in HCMV-infected HFFs treated with the EGS. Conclusions These results indicated that UL49 gene was essential for replication of HCMV. Moreover, our study provides evidence that exogenous administration of a DNA-based EGS can be used as a potential therapeutic approach for inhibiting gene expression and replication of a human virus.</p

Urinary screening of elementary school students in Taicang, China

AbstractBackground: Chronic kidney disease in children is a severe progressive disease that influences the growth, development, and life quality of patients. This study aimed to explore the detection rate of proteinuria and hematuria in elementary school students in Taicang, China.Materials and methods: From 2015 to 2019, urine specimens were selected from 11,753 pupils in Taicang. The samples were tested for proteinuria and hematuria by applying single urine tests and urine sediment microscopic examinations. The observation results were divided into three groups: hematuria, proteinuria, and co-existing hematuria and proteinuria. In addition, kidney biopsies were carried out.Results: The positive rate of urinary abnormalities was 0.842% (99 cases), of which there were 51 cases (0.433%) of proteinuria, 42 cases (0.357%) of hematuria, and six cases (0.051%) of co-existing proteinuria and hematuria. In terms of gender, of the 99 cases, 63 were female students (1.142%) and 36 were male students (0.577%). Additionally, the age distribution results indicated that the prevalence of urine abnormalities in each age group from age 7 to age 13 were 11.11%, 12.12%, 12.12%, 16.16%, 29.29%, 18.18% and 3.03%, respectively. Furthermore, one immunoglobin A nephropathy case was certified by renal biopsy assay in the follow-up at six months.Conclusions: The urine screening revealed that abnormal proteinuria was the main form of urinary abnormalities in elementary school students from Taicang. Urine screening is necessary for early detection and intervention of kidney disease. [Ethiop. J. Health Dev. 2021; 35(2):91-96] Key words: Urine screening, Taicang, elementary school student, proteinuria, hematuri

Surface Electromyography Analysis of the Lower Extremities of Subjects Participating in Baduanjin Exercises

Purpose. The purpose of this study was to assess the effects of practicing Baduanjin exercises on the lower extremities of subjects using electromyography analysis. Subjects. 110 healthy adults were randomly assigned as subjects to two groups: SG group who received sixteen weeks of Baduanjin training and CG group who received no training. Methods. The methods used in this study included the use of a sixteen-channel sEMG system to record and measure activity changes in vastus medialis and vastus lateralis. Results. After 16 weeks of Baduanjin training, the results of this study showed that the SG group had significant increases in RMS (root mean square) (in vastus lateralis, p > 0.05; in vastus medialis, p < 0.05), in AEMG (average electromyographic activity) (in vastus lateralis, p > 0.05; in vastus medialis, p < 0.05), and in IEMG (integrated electromyogram) (in vastus lateralis, p > 0.05; in vastus medialis, p < 0.05). No adverse events from treatment were reported during the whole period of this study. Conclusion. This study concludes that performing 16 weeks of Baduanjin training can significantly improve strength and the physical function of the lower extremities among healthy adults

Studies of dopamine oxidation process by atmospheric pressure glow discharge mass spectrometry

An atmospheric pressure glow discharge ionisation source was constructed and utilized to study the dopamine (DA) oxidation process coupling with mass spectrometry. During the DA oxidation process catalysed by polyphenol oxidase (PPO), six cationic intermediates were directly detected by the atmospheric pressure glow discharge mass spectrometry (APGD-MS). Combined with tandem mass spectrometry, the structures of the dopamine o-semiquinone radical (DASQ) and leukodopaminochrome radical (LDAC●) intermediates and structures of the isomers of dopaminochrome (DAC) and 5,6-dihydroxyindole (DHI) were further characterised with the introduction of 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) and deuterium oxide (D2O) to APGD-MS. Meanwhile, UV–Vis studies confirmed the important role of PPO in catalyzing the DA oxidation reaction. Based on APGD-MS studies, a possible mechanism could be proposed for DA oxidation catalysed by PPO. Furthermore, APGD-MS could provide possibilities for the effective detection and characterisation of short-lived intermediates, even in complicated systems

Elevated first-trimester hepcidin level is associated with reduced risk of iron deficiency anemia in late pregnancy: a prospective cohort study

BackgroundIron deficiency (ID) and iron deficiency anemia (IDA) during pregnancy are highly prevalent worldwide. Hepcidin is considered an important biomarker of iron status. Currently, few longitudinal cohort studies have assessed the potential causal relationship between hepcidin and ID/IDA. Therefore, we aimed to investigate the association of first-trimester maternal serum hepcidin with third-trimester ID/IDA risk in a prospective cohort.MethodsTotal of 353 non-ID/IDA pregnant women at 11–13 weeks’ gestation were enrolled in Southern China and followed up to 38 weeks of gestation. Data on demography and anthropometry were obtained from a structured questionnaire at enrollment. Iron biomarkers including hepcidin were measured at enrollment and follow-up. Regression models were used to evaluate the association of first-trimester hepcidin with third-trimester ID/IDA risk.ResultsSerum hepcidin levels substantially decreased from 19.39 ng/mL in the first trimester to 1.32 ng/mL in the third trimester. Incidences of third-trimester ID and IDA were 46.2 and 11.4%, respectively. Moreover, moderate and high levels of first-trimester hepcidin were positively related to third-trimester hepcidin (log-transformed β = 0.51; 95% CI = 0.01, 1.00 and log-transformed β = 0.66; 95% CI = 0.15, 1.17). Importantly, elevated first-trimester hepcidin was significantly associated with reduced risk of third-trimester IDA (OR = 0.38; 95% CI = 0.15, 0.99), but not with ID after adjustment with potential confounders.ConclusionFirst-trimester hepcidin was negatively associated with IDA risk in late pregnancy, indicating higher first-trimester hepcidin level may predict reduced risk for developing IDA. Nonetheless, given the limited sample size, larger studies are still needed