Association of serum 25-hydroxyvitamin D with cardiovascular mortality and kidney outcome in patients with early stages of CKD

PURPOSE

While serum 25-hydroxyvitamin D (25[OH]D) deficiency is prevalent in chronic kidney disease (CKD), the effects of 25(OH)D deficiency on cardiovascular mortality and kidney outcomes in patients with early-stage CKD remain incompletely understood.

METHODS

This multicenter retrospective cohort study included adult patients with stages 1-3 CKD from 19 medical centers across China between January 2000 and May 2021. The primary outcome was cardiovascular mortality. The secondary study outcome included CKD progression (defined as a sustained > 40% eGFR decrease from baseline or progress to end-stage kidney disease), and annual percentage change of eGFR.

RESULTS

Of 9229 adults with stages 1-3 CKD, 27.0% and 38.9% had severe (< 10 ng/mL) and moderate (10 to < 20 ng/mL) serum 25(OH)D deficiency, respectively. Compared with patients having 25(OH)D ≥ 20 ng/mL, a significantly higher risk of cardiovascular mortality (hazard ratio [HR] 1.90, 95% CI 1.37-2.63), CKD progression (HR 2.20, 95% CI 1.68-2.88), and a steeper annual decline in eGFR (estimate - 7.87%; 95% CI - 10.24% to - 5.51% per year) was found in those with serum 25(OH)D < 10 ng/mL. Similar results were obtained in subgroups and by sensitivity analyses.

CONCLUSIONS

25(OH)D deficiency is associated with increased risks of cardiovascular mortality and CKD progression in patients with early-stage CKD. Studies are needed to determine whether early intervention for 25(OH)D deficiency could improve the prognosis of patients with early-stage CKD.

Distinct clinical features of transplanted children with Parvovirus B19 infection

BACKGROUND

The immature and suppressed immune response makes transplanted children a special susceptible group to Parvovirus B19 (PVB19). However, the clinical features of transplanted children with PVB19 infection haven't been comprehensively described.

METHODS

We searched the medical records of all the transplant recipients who attended the Children's Hospital of Fudan University from 1 Oct 2020 to 31 May 2023, and reviewed the medical literature for PVB19 infection cases among transplanted children.

RESULTS

A total of 10 cases of PVB19 infection were identified in 201 transplanted children at our hospital, and the medical records of each of these cases were shown. Also, we retrieved 40 cases of PVB19 infection among transplanted children from the literature, thus summarizing a total of 50 unique cases of PVB19 infection. The median time to the first positive PVB19 DNA detection was 14 weeks post-transplantation. PVB19 IgM and IgG were detected in merely 26% and 24% of the children, respectively. The incidence of graft loss/dysfunction was as high as 36%. Hematopoietic stem cell transplant (HSCT) recipients showed higher PVB19 load, lower HGB level, greater platelet damage, lower PVB19 IgM/IgG positive rates, and more graft dysfunction than solid-organ transplant (SOT) recipients, indicating a more incompetent immune system.

CONCLUSIONS

Compared with the published data of transplanted adults, transplanted children displayed distinct clinical features upon PVB19 infection, including lower PVB19 IgM/IgG positive rates, more graft dysfunction, and broader damage on hematopoietic cell lines, which was even more prominent in HSCT recipients, thus should be of greater concern.

Nano-flow cytometry unveils mitochondrial permeability transition process and multi-pathway cell death induction for cancer therapy

Mitochondrial permeability transition (mPT)-mediated mitochondrial dysfunction plays a pivotal role in various human diseases. However, the intricate details of its mechanisms and the sequence of events remain elusive, primarily due to the interference caused by Bax/Bak-induced mitochondrial outer membrane permeabilization (MOMP). To address these, we have developed a methodology that utilizes nano-flow cytometry (nFCM) to quantitatively analyze the opening of mitochondrial permeability transition pore (mPTP), dissipation of mitochondrial membrane potential ( Δ Ψm), release of cytochrome c (Cyt c), and other molecular alternations of isolated mitochondria in response to mPT induction at the single-mitochondrion level. It was identified that betulinic acid (BetA) and antimycin A can directly induce mitochondrial dysfunction through mPT-mediated mechanisms, while cisplatin and staurosporine cannot. In addition, the nFCM analysis also revealed that BetA primarily induces mPTP opening through a reduction in Bcl-2 and Bcl-xL protein levels, along with an elevation in ROS content. Employing dose and time-dependent strategies of BetA, for the first time, we experimentally verified the sequential occurrence of mPTP opening and Δ Ψm depolarization prior to the release of Cyt c during mPT-mediated mitochondrial dysfunction. Notably, our study uncovers a simultaneous release of cell-death-associated factors, including Cyt c, AIF, PNPT1, and mtDNA during mPT, implying the initiation of multiple cell death pathways. Intriguingly, BetA induces caspase-independent cell death, even in the absence of Bax/Bak, thereby overcoming drug resistance. The presented findings offer new insights into mPT-mediated mitochondrial dysfunction using nFCM, emphasizing the potential for targeting such dysfunction in innovative cancer therapies and interventions.

Extreme terahertz magnon multiplication induced by resonant magnetic pulse pairs

Nonlinear interactions of spin-waves and their quanta, magnons, have emerged as prominent candidates for interference-based technology, ranging from quantum transduction to antiferromagnetic spintronics. Yet magnon multiplication in the terahertz (THz) spectral region represents a major challenge. Intense, resonant magnetic fields from THz pulse-pairs with controllable phases and amplitudes enable high order THz magnon multiplication, distinct from non-resonant nonlinearities such as the high harmonic generation by below-band gap electric fields. Here, we demonstrate exceptionally high-order THz nonlinear magnonics. It manifests as 7th-order spin-wave-mixing and 6th harmonic magnon generation in an antiferromagnetic orthoferrite. We use THz two-dimensional coherent spectroscopy to achieve high-sensitivity detection of nonlinear magnon interactions up to six-magnon quanta in strongly-driven many-magnon correlated states. The high-order magnon multiplication, supported by classical and quantum spin simulations, elucidates the significance of four-fold magnetic anisotropy and Dzyaloshinskii-Moriya symmetry breaking. Moreover, our results shed light on the potential quantum fluctuation properties inherent in nonlinear magnons.

Uric acid is negatively associated with cognition in the first- episode of schizophrenia

BACKGROUND

We explored the relationship between levels of serum uric acid (UA) and cognitive impairment in people with schizophrenia to order to better protect and improve cognitive function in such patients.

METHODS

A uricase method evaluated serum UA levels in 82 individuals with first-episode schizophrenia and in 39 healthy controls. The Brief Psychiatric Rating Scale (BPRS) and the event-related potential P300 were used to assess the patient's psychiatric symptoms and cognitive functioning. The link between serum UA levels, BPRS scores, and P300 was investigated.

RESULTS

Prior to treatment, serum UA levels and latency N3 in the study group were significantly higher than in the control group, whereas the amplitude P3 was considerably lower. After therapy, the study group's BPRS scores, serum UA levels, latency N3, and amplitude P3 were lower than before treatment. According to correlation analysis, serum UA levels in the pre-treatment study group significantly positively correlated with BPRS score and latency N3 but not amplitude P3. After therapy, serum UA levels were no longer substantially related to the BPRS score or amplitude P3 but strongly and positively correlated with latency N3.

CONCLUSIONS

First-episode schizophrenia patients have higher serum UA levels than the general population which partly reflects poor cognitive performance. Improving patients' cognitive function may be facilitated by lowering serum UA levels.

Postpandemic immunity debt of influenza in the USA and England: an interrupted time series study

OBJECTIVES

The concept of "immunity debt" has gained attention in the public sphere, and some have argued that the recent out-of-season resurgence of respiratory syncytial virus demonstrates the presence of immunity debt. This study investigates the existence of immunity debt in the context of influenza.

STUDY DESIGN

Interrupted time series analysis.

METHODS

The positivity rate of influenza in the USA and England was gathered from the Centers for Disease Control and Prevention and the UK Health Security Agency. A time series model with an autoregressive approach was used to model the dynamics of positivity rate. Binary indicator variables were included in the model to account for the impact of non-pharmaceutical interventions (NPIs) and immunity debt.

RESULTS

The impact of NPIs and immunity debt on the positivity rate of influenza was found to be statistically significant.

CONCLUSIONS

This present work provides evidence supporting the existence of immunity debt in influenza in both the USA and England in the immediate month following the removal of NPIs such as lockdowns and facemask mandates.

Mitochondrial Esterase Activity Measured at the Single Organelle Level by Nano-flow Cytometry

Monitoring mitochondrial esterase activity is crucial not only for investigating mitochondrial metabolism but also for assessing the effectiveness of mitochondrial-targeting prodrugs. However, accurately detecting esterase activity within mitochondria poses challenges due to its ubiquitous presence in cells and the uncontrolled localization of fluorogenic probes. To overcome this hurdle and reveal variations among different mitochondria, we isolated mitochondria and preserved their activity and functionality in a buffered environment. Subsequently, we utilized a laboratory-built nano-flow cytometer in conjunction with an esterase-responsive calcein-AM fluorescent probe to measure the esterase activity of individual mitochondria. This approach enabled us to investigate the influence of temperature, pH, metal ions, and various compounds on the mitochondrial esterase activity without any interference from other cellular constituents. Interestingly, we observed a decline in the mitochondrial esterase activity following the administration of mitochondrial respiratory chain inhibitors. Furthermore, we found that mitochondrial esterase activity was notably higher in the presence of a high concentration of ATP compared to that of ADP and AMP. Additionally, we noticed a correlation between elevated levels of complex IV and increased mitochondrial esterase activity. These findings suggest a functional connection between the mitochondrial respiratory chain and mitochondrial esterase activity. Moreover, we detected an upsurge in mitochondrial esterase activity during the early stages of apoptosis, while cellular esterase activity decreased. This highlights the significance of analyzing enzyme activity within specific organelle subregions. In summary, the integration of a nano-flow cytometer and fluorescent dyes introduces a novel method for quantifying mitochondrial enzyme activity with the potential to uncover the alterations and unique functions of other mitochondrial enzymes.

Sex-Related Effect of Aging in Gingival Gamma-Delta T Cells

Aging affects the number and function of gamma-delta (γδ) T cells in a tissue-specific manner, modifying the risk for inflammatory disease. These aging-related γδT-cell variations in gingival tissues that could increase the risk for inflammation and periodontal disease remain unknown. Here we sought to identify quantitative and qualitative variations in gingival γδT cells associated with aging that could have an impact in oral immunoinflammatory responses. For this, gingival tissues from young (4 mo) and aged (24 mo) male and female mice were collected and analyzed by flow cytometry. Cell suspensions were stimulated and stained with eFluor450 (cell viability), anti-CD45 (hematopoietic cells), anti-CD3 (lymphocytes), anti-TCRγδ (γδT cells), anti-IL-15rα (cell proliferation), and anti-Notch-3 (senescence marker). Detection of intracellular cytokines IL-17A and interferon γ (IFNγ) was performed. Gingival expression of specific γ- and δ-chains and cytokines was evaluated by quantitative reverse transcription polymerase chain reaction. A significantly higher number of IL-17A-producing γδT cells and IL-17A expression levels were observed in gingival tissues from aged females but not males. Similarly, the number of gingival Notch-3+ γδT cells increased with aging only in females. IL-15rα was not detected in gingival γδT cells. Chains γ1, 2, 4, 5, 6, and 7 as well as δ1, 2, 4, and 6 were detected. Detection levels of all γ chains except γ1 as well as δ1 and δ2 changed with aging in males, females, or both. Interestingly, number of IL-17A-producing conventional T cells similarly increased with aging only in females. Both sexes showed increased IFNγ+ conventional T-cell numbers with aging; however, it reached significance only in females. In conclusion, the number of gingival IL-17A-producing γδT cells and IL-17A expression increase naturally with aging specifically in females. This sexual dimorphism in gingival γδT and conventional Th17 cell numbers and phenotypes suggests distinct aging-related mechanisms of periodontitis in males and females.

Testosterone promotes the migration, invasion and EMT process of papillary thyroid carcinoma by up-regulating Tnnt1

PURPOSE

To explore the key genes and molecular pathways in the progression of thyroid papillary carcinoma (PTC) promoted by testosterone using RNA-sequencing technology, and to provide new drug targets for improving the therapeutic effect of PTC.

METHODS

Orchiectomy (ORX) was carried out to construct ORX mouse models. TPC-1 cells were subcutaneously injected for PTC formation in mice, and the tumor tissues were collected for RNA-seq. The key genes were screened by bioinformatics technology. Tnnt1 expression in PTC cells was knocked down or overexpressed by transfection. Cell counting kit-8 (CCK-8), colony formation assay, scratch assay and transwell assay were adopted, respectively, for the detection of cell proliferation, colony formation, migration and invasion. Besides, quantification real-time polymerase chain reaction (qRT-PCR) and western blot were utilized to determine the mRNA and protein expression levels of genes in tissues or cells.

RESULTS

Both estradiol and testosterone promoted the growth of PTC xenografts. The key gene Tnnt1 was screened and obtained by bioinformatics technology. Functional analysis revealed that overexpression of Tnnt1 could markedly promote the proliferation, colony formation, migration, invasion, and epithelial-to-mesenchymal transition (EMT) process of PTC cells, as well as could activate p38/JNK pathway. In addition, si-Tnt1 was able to inhibit the cancer-promoting effect of testosterone.

CONCLUSION

Based on the outcomes of bioinformatics and basic experiments, it is found that testosterone can promote malignant behaviors such as growth, migration, invasion and EMT process of PTC by up-regulating Tnnt1 expression. In addition, the function of testosterone may be achieved by activating p38/JNK signaling pathway.

Emergence and high prevalence of unusual rotavirus G8P[8] strains in outpatients with acute gastroenteritis in Shanghai, China

Group A rotavirus (RVA) is considered an important cause of acute gastroenteritis (AGE) in all age groups, especially in children. We investigated the epidemiology of RVA in outpatients aged ≤ 16 years at the Children's Hospital of Fudan University, Shanghai, China. In this study, 16.6% (246/1482) were infected with RVA. The detection rate of RVA was significantly higher in the year of 2021 (20.3%, 147/725) compared to the year of 2020 (14.5%, 77/531) and 2022 (9.7%, 22/226) (p = 0.000). RVA infection was prevalent in all seasons from 2020 to 2022, with a different monthly distribution observed in different years. Among 246 RVA-positive samples, 14 different RVA genotypes were detected with different frequencies. Overall, G9P[8] (45.5%, 112/246) was the most common RVA genotype, followed by G8P[8] (37.4%, 92/246) and G3P[8] (4.1%, 10/246). The prevalence of G/P combinations varied from 2020 to 2022. G9P[8] was the most prevalent circulating genotype in 2020 (68.2%, 15/22) and 2021 (57.8%, 85/147). However, G8P[8] (68.8%, 53/77) suddenly became the most prevalent genotype in 2022 after being first identified in 2020 and prevalent in 2021. The G8 strains detected in the study were all clustered to DS-1-like G8 strains with the closest genetic distance to strains circulating in Southeast Asia. Our study demonstrated the diversity of circulating RVA genotypes in Shanghai. The sudden emergence and high prevalence of unusual G8P[8] strains deserve more concern and indicate the need for continuous surveillance of RVA in children with AGE in the future to refine future vaccine strategy.

Primary human thyrocytes maintained the function of thyroid hormone production and secretion in vitro

PURPOSE

Thyroid cell lines are useful tools to study the physiology and pathology of the thyroid, however, they do not produce or secrete hormones in vitro. On the other hand, the detection of endogenous thyroid hormones in primary thyrocytes was often hindered by the dedifferentiation of thyrocytes ex vivo and the presence of large amounts of exogenous hormones in the culture medium. This study aimed to create a culture system that could maintain the function of thyrocytes to produce and secrete thyroid hormones in vitro.

METHODS

We established a Transwell culture system of primary human thyrocytes. Thyrocytes were seeded on a porous membrane in the inner chamber of the Transwell with top and bottom surfaces exposed to different culture components, mimicking the 'lumen-capillary' structure of the thyroid follicle. Moreover, to eliminate exogenous thyroid hormones from the culture medium, two alternatives were tried: a culture recipe using hormone-reduced serum and a serum-free culture recipe.

RESULTS

The results showed that primary human thyrocytes expressed thyroid-specific genes at higher levels in the Transwell system than in the monolayer culture. Hormones were detected in the Transwell system even in the absence of serum. The age of the donor was negatively related to the hormone production of thyrocytes in vitro. Intriguingly, primary human thyrocytes cultured without serum secreted higher levels of free triiodothyronine (FT3) than free thyroxine (FT4).

CONCLUSION

This study confirmed that primary human thyrocytes could maintain the function of hormone production and secretion in the Transwell system, thus providing a useful tool to study thyroid function in vitro.

[Animal study on left bundle branch current of injury and anatomic location of leads in His-purkinje conduction system pacing]

Objective: Explore the relationship between tip of the left bundle branch pacing lead and anatomic location of left bundle branch as well as the mechanism of left bundle branch current of injury. To clarify the clinical value of left bundle branch current of injury during operation. Methods: The pacing leads were implanted in the hearts of two living swines. Intraoperative electrophysiological study confirmed that the left bundle branch or only the deep left ventricular septum was captured at low output. Immediately after operation, the gross specimen of swine hearts was stained with iodine to observe the gross distribution of His-purkinje conduction system on the left ventricular endocardium and its relationship with the leads. Subsequently, the swine hearts were fixed with formalin solution, and the pacing leads were removed after the positions were marked. The swine hearts were then sectioned and stained with Masson and Goldner trichrome, and the relationship between the anatomic location of the conduction system and the tip of the lead was observed under a light microscope. Results: After iodine staining of the specimen, the His-purkinje conduction system was observed with the naked eye in a net-like distribution, and the lead tip was screwed deeply and fixed in the left bundle branch area of the left ventricular subendocardium in the ventricular septum. Masson and Goldner trichrome staining showed that left bundle branch pacing lead directly passed through the left bundle branch when there was left bundle branch potential with left bundle branch current of injury, while it was not directly contact the left bundle branch when there was left bundle branch potential without left bundle branch current of injury. Conclusion: The left bundle branch current of injury observed on intracardiac electrocardiogram during His-purkinje conduction system pacing suggests that the pacing lead directly contacted the conduction bundle or its branches, therefore, the captured threshold was relatively low. Left bundle branch current of injury can be used as an important anatomic and electrophysiological evidence of left bundle branch capture.

Diversity of classic and novel human astrovirus in outpatient children with acute gastroenteritis in Shanghai, China

Introduction

Human astrovirus (HAstV) is an important pathogen of acute gastroenteritis (AGE) in children. This study was aimed at investigating the diversity and epidemiology of classic and novel HAstV in outpatient children aged 0-16 years old with AGE in Shanghai.

Methods

From May 2020 to December 2022, a total of 1,482 stool samples were collected from children diagnosed as AGE from the Children's Hospital of Fudan University. HAstV was identified using pan-astrovirus consensus primers by Reverse transcription PCR.

Results

During the study period, 3.3% (49/1,482) of specimens were identified as HAstV, with a detection rate of 2.5% (37/1,482) for classic HAstV and 0.8% (12/1,482) for novel HAstV. Among the 12 novel HAstV strains, 11 (91.7%) belonged to the HAstV-MLB and 1 (8.3%) was HAstV-VA. Genotyping revealed six circulating genotypes. Strain HAstV-1 was predominant in the study population with a detection rate of 1.8% (26/1,482) followed by HAstV-MLB1 (0.7%, 10/1,482) and HAstV-4 (0.6%, 9/1,482). Of note, all the HAstV-4 strains detected in this study were close to one astrovirus strain isolated from Bactrian camels with 99.0-100.0% amino acid sequences identity. In this study, HAstV was detected in all age groups with the highest detection rate of HAstV-positive specimens observed in children older than 73 months (5.7%, 12/209).

Discussion

This study provided useful information and contributed to the molecular epidemiology of both classic and novel HAstV, which were simultaneously characterized and reported for the first time in Shanghai.

Changing predominance of norovirus strains in children with acute gastroenteritis in Shanghai, 2018-2021

Norovirus (NoV) is a major pathogen that causes acute gastroenteritis (AGE) in people of all ages, especially in children. In this study, we investigated the molecular epidemiological characteristics of NoV in children with AGE in Shanghai from 2018 to 2021. The overall detection rate of NoV was 11.9% (181/1545), with annual detection rates of 9.4% (36/381), 13.6% (29/213), 5.8% (13/226) and 14.2% (103/725), respectively. Of note, the prevalence of NoV in 2020 was significantly lower than that in 2018-2019 (10.9%, 65/594) (P ​= ​0.023) and 2021 (14.2%, 103/725) (P ​= ​0.000). The 181 NoV strains identified in this study were classified into the GI group (1.1%, 2/181), GII group (98.3%, 178/181) and GIX group (0.6%, 1/181) according to the VP1 gene. The most common NoV VP1 genotype was GII.4 Sydney_2012 (63.5%, 115/181), followed by GII.3 (19.9%, 36/181) and GII.2 (9.4%, 17/181). For P genotypes, 174 strains were sequenced successfully according to the RdRp gene, and the predominant genotype was GII.P16 (44.8%, 78/174), followed by GII.P31 (25.9%, 45/174) and GII.P12 (21.3%, 37/174). Among the 174 cases, GII.4 Sydney_2012[P16] (36.8%, 64/174) was the dominant genotype, followed by GII.4 Sydney_2012[P31] (25.3%, 44/174), GII.3[P12] (20.1%, 35/174) and GII.2[P16] (8.0%, 14/174). In particular, the dominant genotypes in Shanghai changed from GII.4 Sydney_2012[P31] in 2018-2019 to GII.4 Sydney_2012[P16] in 2020-2021. This is the first report to describe the epidemiological changes in NoV infection before and during the COVID-19 pandemic in Shanghai. These data highlight the importance of continuous surveillance for NoV in children with AGE in Shanghai.

Evaluating the Use of SGRT and Abdominal Compression Device for Improved Patient Positioning in Liver Cancer Radiotherapy

PURPOSE/OBJECTIVE(S)

To mitigate tumor displacement caused by respiratory movement and to enhance positioning accuracy in liver cancer patients during radiotherapy, abdominal compression fixation devices are commonly employed. However, the efficacy of using surface guided radiotherapy (SGRT) to further improve patient setup accuracy in combination with abdominal compression has not been fully established. Hence, we aimed to investigate this in our study.

MATERIALS/METHODS

In this study, we analyzed data from 11 patients with liver cancer. The patients were positioned using isocentric skin markers and the abdominal compression fixture was placed on an accurate scale reading based on the records from CT simulation. A cone-beam CT (CBCT) scan was performed to assess setup errors. These setup errors represent data for the control group - Skin marker group. The patients were then adjusted to the correct treatment position based on CBCT correction and the SGRT system was activated for monitoring. Care was taken for the region of interest drawn to avoid the abdominal compression device for all patients. The reference surface used for monitoring was the captured VRT surface rather than DICOM. The six degrees of freedom values detected by the SGRT system were recorded, representing data for the test group - SGRT group. Both sets of data were analyzed using statistical software. The errors were presented as median (interquartile range) and the differences between the two groups were tested using paired Wilcoxon rank sum test, with P < 0.05 considered as significant.

RESULTS

A total of 60 CBCT images were analyzed, the median values and interquartile ranges are presented in the Table. The results showed that the accuracy of the SGRT group in the x and y directions was significantly better than the skin marker group (P < 0.05). The median values for the x (transverse) direction were 0.25(0.09-0.43) cm and 0.09(0.05-0.19) cm for the skin marker and SGRT groups, respectively. The median values for the y (longitudinal) direction were 0.54 (0.29-0.79) cm and 0.14 (0.07-0.24) cm for the skin marker and SGRT groups, respectively. The results for the z (vertical) direction, Rz (rotation), Ry (roll) and Rx (pitch) rotation directions were also analyzed similarly.

CONCLUSION

The findings of this study suggest that compared to skin markers, SGRT can improve the accuracy of patient positioning in liver cancer radiotherapy with abdominal compression, potentially reducing unnecessary radiation exposure from CBCT imaging due to inaccurate positioning. Further multicenter prospective clinical trials are required to confirm these results.

Surveillance and epidemiological characterization of human adenovirus infections among outpatient children with acute gastroenteritis during the COVID-19 epidemic in Shanghai, China

BACKGROUND

Human adenovirus (HAdV) has been recognized as one of the common enteric viruses associated with acute gastroenteritis (AGE) in children. The aim of this study was carried out to illustrate the epidemiological characterization of HAdV Infections among children younger than 15 years in Shanghai during COVID-19.

METHODS

During May 2020 and April 2022, 1048 fecal samples were collected from children ≤ 15 years diagnosed with AGE in the Children's Hospital of Fudan University. HAdV was identified by PCR and sequenced with specific primers. All the obtained sequences were analyzed by MEGA (version 6.0). Demographic information and clinical features data were also collected and analyzed.

RESULTS

In total, 97 (9.3%, 97/1048) samples were detected to be HAdV during May 2020 and April 2022. We found an atypical upsurge in HAdV infection in the year 2021 after a major suppression in the year 2020. Approximately 84.5% (82/97) of HAdV-infected children were aged 0-60 months. Among the 97 HAdV-positive samples, only two species and five genotypes were detected. HAdV-F (88.7%, 86/97) was the most prevalent species and HAdV-F41 (87.6%, 85/97) was the most common genotype. Diarrhea, vomiting, and fever were the main clinical manifestations in children infected with HAdV. The children aged from 0 to 12 months showed simpler patterns of clinical presentation than those of children older than 13 months.

CONCLUSIONS

Our findings described the epidemiological changes of HAdV infection in children with AGE during the COVID-19, which further underscored the importance of continuous surveillance of HAdV at both local and global scales.

[Endoscopic ultrasonographic features of submucosal lesions of upper digestive tract suspected gastrointestinal stromal tumors and their correlation with progression and pathological risk grade of the lesions]

Objective: To investigate the endoscopic ultrasonographic (EUS) characteristics of submucosal lesions of upper digestive tract suspected gastrointestinal stromal tumors (GIST) and their correlation with biological behaviors and pathological risk grade of the tumors. Methods: Retrospective cohort study. The EUS findings, follow-up review, surgical treatment and pathological data of patients with suspected GIST at the Gastrointestinal Endoscopy Center of Peking University People's Hospital from January 2013 to April 2021 were collected. All samples were divided into follow-up group and treatment group based on the pathological condition and the patient's treatment intention. According to whether or not the tumor was enlarged in EUS, the follow-up group was divided into non-enlarged group and enlarged group. Paired T-test was used to compare the lesion size before and after follow-up, and logistic regression was used to analyze the risk factors of tumor enlargement. According to the treatment methods, the treatment group was further divided into endoscopic treatment group and surgical treatment group. According to the pathological results and risk grade, the treatment group was further divided into the low-risk group and the medium-risk group. The risk factors of pathological malignant risk were analyzed by logistic regression, and the tumor diameter of patients with moderate or above pathological risk was predicted by receiver operation characteristic (ROC) curve. The relationship between the findings of EUS and the progression and pathological risk of GIST were also explored. Results: Seventy-three cases including 23 males and 50 females, with an age of 58 (30-88) years, were included in the follow-up group, with a mean lesion diameter of (1.21±0.49) cm before follow-up, median follow-up interval of 33.8 months, and a lesion diameter of (1.18±0.49) cm after follow-up. There was no significant difference (all P>0.05) in lesion diameter between before and after follow-up. There was no significant difference (all P>0.05) between tumor enlargement group (18 cases, 24.7%) and non-enlargement group (55 cases, 75.3%). One hundred and thirty-eight cases, including 52 males and 86 females, with an age of 60 (19-84) years, were enrolled in the treatment group, with a mean EUS estimated diameter of (2.55±1.35) cm and pathological diameters of (3.43±2.42) cm. Ninety-five (68.8%) of these cases were pathologically confirmed as GIST while 43 cases were diagnosed as other tumor types, including 37 benign tumors and 6 malignant tumors. In multifactorial logistic regression analysis, only the increase of tumor diameter [OR (95%CI): 1.800 (1.172-2.766), P=0.007] was a risk factor for pathological intermediate or higher risk. The optimal tumor diameter for predicting pathological intermediate or higher risk using ROC curve analysis was 2.75 cm, with a sensitivity 71.4%, specificity 79.0%, Youden index 0.5 and area under ROC curve 0.807 (95%CI: 0.703-0.909). Conclusions: EUS is essential for assessing the risk of progression and malignancy of submucosal lesions of upper digestive tract suspected GIST. For lesions of small diameter, the interval of follow-up shall be relatively extended while the indication of treatment could be partially waived.

Development of Spectral Nano-Flow Cytometry for High-Throughput Multiparameter Analysis of Individual Biological Nanoparticles

Correlated analysis of multiple biochemical parameters at the single-particle level and in a high-throughput manner is essential for insights into the diversity and functions of biological nanoparticles (BNPs), such as bacteria and subcellular organelles. To meet this challenge, we developed a highly sensitive spectral nano-flow cytometer (S-nFCM) by integrating a spectral recording module to a laboratory-built nFCM that is 4-6 orders of magnitude more sensitive in side scattering detection and 1-2 orders of magnitude more sensitive in fluorescence detection than conventional flow cytometers. An electron-multiplying charge-coupled device (EMCCD) was used to acquire the full fluorescence spectra of single BNPs upon holographic grating dispersion. Up to 10,000 spectra can be collected in 1 min with 2.1 nm resolution. The precision, linearity, and sensitivity were examined. Complete discernment of single influenza viruses against the background signal, discrimination of different strains of marine cyanobacteria in a mixed sample based on their spectral properties of natural fluorescence, classification of bacterial categories exhibiting different patterns of antigen expression, and multiparameter analysis of single mitochondria for drug discovery were successfully demonstrated.

Association of Dental Caries with Muscle Mass, Muscle Strength, and Sarcopenia: A Community-Based Study

OBJECTIVES

Changes in the oral cavity can reflect other changes throughout the body. This study aimed to investigate the association of dental caries with muscle mass, muscle strength, and sarcopenia, and also to describe the microbial diversity, composition, and community structure of severe dental caries and sarcopenia.

DESIGN

Cross-sectional study based on a Chinese population aged from 50 to 85 years.

SETTING

Communities from Lanxi City, Zhejiang Province, China.

PARTICIPANTS

A total of 1,442 participants aged from 50 to 85 years from a general community (62.8% women; median age 61.0 [interquartile range: 55.0, 68.0]).

MEASUREMENTS

Dental caries was assessed by the decayed, missing, and filled teeth (DMFT) index. Sarcopenia was defined as the presence of both low muscle mass (assessed by dual-energy X-ray absorptiometry scanning) and low muscle strength (assessed by handgrip strength). Multivariate logistic regression models were used to analyze the association of dental caries with muscle mass, muscle strength, and sarcopenia. Fecal samples underwent 16S rRNA profiling to evaluate the diversity and composition of the gut microbiota in patients with severe dental caries and/or sarcopenia.

RESULTS

In the fully adjusted logistic models, dental caries was positively associated with low muscle strength (DMFT ≥ 7: OR, 1.61; 95% CI, 1.25-2.06), and sarcopenia (DMFT ≥ 7: OR, 1.51; 95% CI, 1.01-2.26), but not low muscle mass. Severe dental caries was positively associated with higher alpha-diversity indices (richness, chao1, and ACE, all p < 0.05) and associated with beta-diversity based on Bray-Curtis distance (p = 0.006). The severe dental caries group and the sarcopenia group overlapped with 11 depleted and 13 enriched genera.

CONCLUSION

Dental caries was positively associated with low muscle strength and sarcopenia but not muscle mass, and this association was more pronounced in male individuals. Significant differences were observed in gut microbiota composition both in severe dental caries and sarcopenia, and there was an overlap of the genera features. Future longitudinal studies are needed to clarify causal relationships.

Distribution of CMV envelope glycoprotein B, H and N genotypes in infants with congenital cytomegalovirus symptomatic infection

Background

Cytomegalovirus (CMV) is the leading cause of congenital infections worldwide and contributes to long-term sequelae in neonates and children. CMV envelope glycoproteins play a vital role in virus entry and cell fusion. The association between CMV polymorphisms and clinical outcomes remains controversial. The present study aims to demonstrate the distribution of glycoprotein B (gB), H (gH) and N (gN) genotypes in congenitally CMV (cCMV) infected symptomatic infants and attempts to figure out the association between viral glycoprotein genotypes and clinical outcomes.

Methods

Genotyping of gB, gH and gN was performed in 42 cCMV symptomatic infants and 149 infants with postnatal CMV (pCMV) infection in Children's hospital of Fudan university. Nested PCR, gene sequencing and phylogenetic analyses were used to identify the genotypes.

Results

Our study demonstrated that: 1. The CMV gB1, gH1 and gN1 were the predominant genotypes among symptomatic cCMV infected infants, while gB1, gH1 and gN3a were more prevalent in pCMV group. gH1 genotype has a significant association with symptomatic cCMV infection (p = 0.006). 2. No significant correlation was found between CMV genotypes and hearing impairment. However, gH1 was more prevalent among cCMV infected infants with moderate/severe hearing loss although without statistical difference (p = 0.130). 3. gB3 was more prevalent among infants with skin petechiae (p = 0.049) and found to be associated with an increased risk of skin petechiae (OR = 6.563). The gN4a subtype was significantly associated with chorioretinitis due to cCMV infection (p = 0.007). 4. Urine viral loads were not significantly associated with different genotypes or hearing impairment among symptomatic cCMV infected infants.

Conclusions

Our findings demonstrated the overall distribution of gB, gH and gN genotypes in infants with symptomatic cCMV infection in Shanghai for the first time. The findings in our study may suggest a possible association between gH1 genotype and early infancy hearing loss. gB3 genotype was associated with a 6.5-fold increased risk of petechiae while gN4a strongly correlated with chorioretinitis due to cCMV infection. No significant correlation was found between urine viral loads and CMV genotypes or hearing impairment in cCMV infected infants.

Metabolic transitions define spermatogonial stem cell maturation

STUDY QUESTION

Do spermatogonia, including spermatogonial stem cells (SSCs), undergo metabolic changes during prepubertal development?

SUMMARY ANSWER

Here, we show that the metabolic phenotype of prepubertal human spermatogonia is distinct from that of adult spermatogonia and that SSC development is characterized by distinct metabolic transitions from oxidative phosphorylation (OXPHOS) to anaerobic metabolism.

WHAT IS KNOWN ALREADY

Maintenance of both mouse and human adult SSCs relies on glycolysis, while embryonic SSC precursors, primordial germ cells (PGCs), exhibit an elevated dependence on OXPHOS. Neonatal porcine SSC precursors reportedly initiate a transition to an adult SSC metabolic phenotype at 2 months of development. However, when and if such a metabolic transition occurs in humans is ambiguous.

STUDY DESIGN, SIZE, DURATION

To address our research questions: (i) we performed a meta-analysis of publicly available and newly generated (current study) single-cell RNA sequencing (scRNA-Seq) datasets in order to establish a roadmap of SSC metabolic development from embryonic stages (embryonic week 6) to adulthood in humans (25 years of age) with a total of ten groups; (ii) in parallel, we analyzed single-cell RNA sequencing datasets of isolated pup (n = 3) and adult (n = 2) murine spermatogonia to determine whether a similar metabolic switch occurs; and (iii) we characterized the mechanisms that regulate these metabolic transitions during SSC maturation by conducting quantitative proteomic analysis using two different ages of prepubertal pig spermatogonia as a model, each with four independently collected cell populations.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Single testicular cells collected from 1-year, 2-year and 7-year-old human males and sorted spermatogonia isolated from 6- to 8-day (n = 3) and 4-month (n = 2) old mice were subjected to scRNA-Seq. The human sequences were individually processed and then merged with the publicly available datasets for a meta-analysis using Seurat V4 package. We then performed a pairwise differential gene expression analysis between groups of age, followed by pathways enrichment analysis using gene set enrichment analysis (cutoff of false discovery rate < 0.05). The sequences from mice were subjected to a similar workflow as described for humans. Early (1-week-old) and late (8-week-old) prepubertal pig spermatogonia were analyzed to reveal underlying cellular mechanisms of the metabolic shift using immunohistochemistry, western blot, qRT-PCR, quantitative proteomics, and culture experiments.

MAIN RESULTS AND THE ROLE OF CHANCE

Human PGCs and prepubertal human spermatogonia show an enrichment of OXPHOS-associated genes, which is downregulated at the onset of puberty (P < 0.0001). Furthermore, we demonstrate that similar metabolic changes between pup and adult spermatogonia are detectable in the mouse (P < 0.0001). In humans, the metabolic transition at puberty is also preceded by a drastic change in SSC shape at 11 years of age (P < 0.0001). Using a pig model, we reveal that this metabolic shift could be regulated by an insulin growth factor-1 dependent signaling pathway via mammalian target of rapamycin and proteasome inhibition.

LARGE SCALE DATA

New single-cell RNA sequencing datasets obtained from this study are freely available through NCBI GEO with accession number GSE196819.

LIMITATIONS, REASONS FOR CAUTION

Human prepubertal tissue samples are scarce, which led to the investigation of a low number of samples per age. Gene enrichment analysis gives only an indication about the functional state of the cells. Due to limited numbers of prepubertal human spermatogonia, porcine spermatogonia were used for further proteomic and in vitro analyses.

WIDER IMPLICATIONS OF THE FINDINGS

We show that prepubertal human spermatogonia exhibit high OXHPOS and switch to an adult-like metabolism only after 11 years of age. Prepubescent cancer survivors often suffer from infertility in adulthood. SSC transplantation could provide a powerful tool for the treatment of infertility; however, it requires high cell numbers. This work provides key insight into the dynamic metabolic requirements of human SSCs across development that would be critical in establishing ex vivo systems to support expansion and sustained function of SSCs toward clinical use.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the NIH/NICHD R01 HD091068 and NIH/ORIP R01 OD016575 to I.D. K.E.O. was supported by R01 HD100197. S.K.M. was supported by T32 HD087194 and F31 HD101323. The authors declare no conflict of interest.

Resurgence of Respiratory Syncytial Virus Infection During COVID-19 Pandemic Among Children in Shanghai, China

Respiratory syncytial virus (RSV) is the most common pathogen causing acute lower respiratory tract infection (LRTI) in children. RSV usually peaks in winter and declines by early spring in China. The outbreak of coronavirus disease 2019 (COVID-19) was reported to bring changes to the transmission pattern of respiratory pathogens including RSV. Here in this paper, we analyzed RSV-positive nasopharyngeal aspirates from inpatients in the Children’s Hospital of Fudan University from October 2019 to October 2021 and compared the clinical features of the RSV-positive patients before and during COVID-19. We found an atypical upsurge of RSV infection in the late summer of 2021 after a major suppression in 2020. RSV B was the main subtype spreading among children throughout the study. Phylogenetic analysis revealed that all RSV A strains belonged to ON1 genotype and all RSV B strains were BA9 genotype. Deduced amino acid analysis displayed different substitutions in the RSV strains observed before and during COVID-19. Demographic analysis suggested that males and infants aged under 5 months were the main populations infected with RSV by gender and age, respectively. Less severe clinical outcomes were observed in patients during COVID-19 than before the pandemic, especially in RSV B-positive patients. Our findings described the epidemiological changes in RSV infection brought by COVID-19, which further underscored the importance of continuous surveillance of RSV in the shadow of COVID-19 at both local and global scales.

The changing pattern of common respiratory and enteric viruses among outpatient children in Shanghai, China: Two years of the COVID-19 pandemic

OBJECTIVE

Nonpharmaceutical interventions (NPIs) taken to combat the coronavirus disease 2019 (COVID-19) pandemic have not only decreased the spread of SARS-CoV-2 but also have had an impact on the prevalence of other common viruses. This study aimed to investigate the long-term impact of NPIs on common respiratory and enteric viruses among children in Shanghai, as NPIs were relaxed after June 2020.

METHODS

The laboratory results and clinical data of outpatient children with acute respiratory tract infections (ARTI) and acute gastroenteritis (AGE) were analyzed and compared between the post-COVID-19 period (from June 2020 to January 2022) and pre-COVID-19 period (from June 2018 to January 2020).

RESULTS

A total of 107,453 patients were enrolled from June 2018 to January 2022, including 43,190 patients with ARTI and 64,263 patients with AGE. The positive rates of most viruses decreased during the post-COVID-19 period, with the greatest decrease for influenza A (-90.94%), followed by adenoviruses (AdV) (-61.54%), rotaviruses (-48.17%), and influenza B (-40%). However, the positive rates of respiratory syncytial virus (RSV) and enteric AdV increased during the post-COVID-19 period as the NPIs were relaxed. Besides, in the summer of 2021, an unexpected out-of-season resurgence of RSV activity was observed, and the resurgence was more prominent among children older than 5 years.

CONCLUSIONS

The effectiveness of the current relaxed NPIs in control of common respiratory and enteric viruses was variable. Relaxation of NPIs might lead to resurgence of common viruses. This article is protected by copyright. All rights reserved.

Prevalence and genotypes distribution of group A rotavirus among outpatient children under 5 years with acute diarrhea in Shanghai, China, 2012-2018

Background

Group A rotavirus (RVA) remains the main causative agent of acute diarrhea among children under five years in countries that have not yet introduced the RVA vaccine worldwide. Long-term and continuous monitoring data on RVA infection in outpatient children were lacking in Shanghai. We investigated the prevalence and distribution of RVA genotypes in outpatient children with acute diarrhea in Shanghai from 2012 to 2018.

Methods

Stool specimens of outpatient children under five years were collected from the Children’s Hospital of Fudan University in Shanghai, China. All the samples enrolled in this study were detected and characterized for the P and G genotypes of RVA were determined using the semi-multiplex RT-PCR technique.

Results

Of 1814 children enrolled with acute diarrhea and having specimens collected, 246 (13.6%) were infected with RVA. The highest frequency of RVA was observed in children younger than two years old (87.0%, 214/246). Year-round RVA transmission was observed and the RVA detection rate peaked every winter and troughed in summer. In this study, 12 different RVA strains were identified in children. G9P[8] (49.2%, 121/246) was detected as the most prevalent genotype, followed by G–P[8] (22.8%, 56/246), G3P[8] (11.4%, 28/246), and G9P- (4.9%, 12/246). Although RVA strains detected in this study varied with the time, G9P[8] has been the most predominant circulating genotype since 2012. Furthermore, 12.2% (30/246) RVA positive samples were co-infected with other diarrhea viruses.

Conclusion

The present analysis showed that RVA was still a major cause of children with acute diarrhea in Shanghai from 2012 to 2018. A great diversity of RVA strains circulated in children with acute diarrhea with G9P[8] being the predominant genotype since 2012. Long-term and continuous monitoring of RVA genotypes is therefore indispensable to refine future vaccine strategy in Shanghai.

Development of a multiplex droplet digital PCR assay for detection of enterovirus, parechovirus, herpes simplex virus 1 and 2 simultaneously for diagnosis of viral CNS infections

Background

Enterovirus (EV), parechovirus (HPeV), herpes simplex virus 1 and 2 (HSV1/2) are common viruses leading to viral central nervous system (CNS) infections which are increasingly predominant but exhibit deficiency in definite pathogen diagnosis with gold-standard quantitative PCR method. Previous studies have shown that droplet digital PCR (ddPCR) has great potential in pathogen detection and quantification, especially in low concentration samples.

Methods

Targeting four common viruses of EV, HPeV, HSV1, and HSV2 in cerebrospinal fluid (CSF), we developed a multiplex ddPCR assay using probe ratio-based multiplexing strategy, analyzed the performance, and evaluated it in 97 CSF samples collected from patients with suspected viral CNS infections on a two-channel ddPCR detection system.

Results

The four viruses were clearly distinguished by their corresponding fluorescence amplitude. The limits of detection for EV, HPeV, HSV1, and HSV2 were 5, 10, 5, and 10 copies per reaction, respectively. The dynamic range was at least four orders of magnitude spanning from 2000 to 2 copies per reaction. The results of 97 tested clinical CSF specimens were identical to those deduced from qPCR/qRT-PCR assays using commercial kits.

Conclusion

The multiplex ddPCR assay was demonstrated to be an accurate and robust method which could detect EV, HPeV, HSV1, and HSV2 simultaneously. It provides a useful tool for clinical diagnosis and disease monitoring of viral CNS infections.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12985-022-01798-y.

Comparison of Respiratory Pathogens in Children With Lower Respiratory Tract Infections Before and During the COVID-19 Pandemic in Shanghai, China

OBJECTIVES

This study aimed to assess the impact of COVID-19 on the prevalence of respiratory pathogens among hospitalized children with lower respiratory tract infections (LRTIs) in Shanghai.

METHODS

Respiratory specimens were collected from children with LRTIs in Children's Hospital of Fudan University from February 2019 to January 2021 and common respiratory pathogens were detected using multiplex PCR. The data of 13 respiratory pathogens were analyzed and compared between the year of 2020 (from February 2020 to January 2021) and 2019 (from February 2019 to January 2020).

RESULTS

A total of 1,049 patients were enrolled, including 417 patients in 2019 and 632 patients in 2020. In 2020, 27.53% of patients were tested positive for at least one pathogen, which was significantly lower than that in 2019 (78.66%). The top three pathogens were Mycoplasma pneumoniae (Mp), human adenovirus (ADV) and human rhinovirus (RV) in 2019, whereas RV, human respiratory syncytial virus (RSV) and human parainfluenza virus (PIV) were the predominant ones in 2020. The positive rates of Mp, ADV, RV, PIV, Influenza virus B (InfB), H3N2, and H1N1 were significantly decreased in 2020. RV was the most detectable respiratory pathogen in 2020, and become the most frequent pathogen in all five age groups. PIV had a high prevalence from October to December 2020 which was even higher than that in 2019. Influenza virus A (InfA) was not detected in 2020. Co-infection was significantly less frequent in 2020.

CONCLUSION

The public health interventions aiming to eliminate COVID-19 have great impact on the prevalence of common respiratory pathogens. The prevalence of RV and PIV reminds us a possible resurgence of some pathogens.

Developing a near-infrared spectroscopy and microwave-induced thermoacoustic tomography-based dual-modality imaging system

Near-infrared spectroscopy (NIRS) techniques can provide noninvasive in vivo hemoglobin oxygenation information but suffer from relatively low resolution in biological tissue imaging. Microwave-induced thermoacoustic tomography (TAT) can produce high-resolution images of the biological tissue anatomy but offer limited physiological information of samples because of the single species of the chromophore it maps. To overcome these drawbacks and take advantage of the merits of the two independent techniques, we built a dual-modality system by combining a NIRS system and a TAT system to image biological tissues. A series of phantom trials were carried out to demonstrate the performance of the new system. The spatial resolution is about 1 mm, with a penetration depth of at least 17.5 mm in the human subject. A cohort of five healthy subjects was recruited to conduct real-time forearm venous and arterial cuff occlusion experiments. Numerous results showed that this dual-modality system could measure oxygen metabolism and simultaneously provide anatomical structure changes of biological tissues. We also found that although the hemoglobin concentration varied consistently with many other published papers, the TAT signal intensity of veins showed an opposite variation tendency in the venous occlusion stage compared with other existing work. A detailed explanation is given to account for the discrepancy, thus, providing another possibility for the forearm experiments using TAT. Furthermore, based on the multiple types of information afforded by this dual-modality system, a pilot clinical application for the diagnosis of anemia is discussed.

Active cargo loading into extracellular vesicles: Highlights the heterogeneous encapsulation behaviour

Extracellular vesicles (EVs) have demonstrated unique advantages in serving as nanocarriers for drug delivery, yet the cargo encapsulation efficiency is far from expectation, especially for hydrophilic chemotherapeutic drugs. Besides, the intrinsic heterogeneity of EVs renders it difficult to evaluate drug encapsulation behaviour. Inspired by the active drug loading strategy of liposomal nanomedicines, here we report the development of a method, named "Sonication and Extrusion-assisted Active Loading" (SEAL), for effective and stable drug encapsulation of EVs. Using doxorubicin-loaded milk-derived EVs (Dox-mEVs) as the model system, sonication was applied to temporarily permeabilize the membrane, facilitating the influx of ammonium sulfate solution into the lumen to establish the transmembrane ion gradient essential for active loading. Along with extrusion to downsize large mEVs, homogenize particle size and reshape the nonspherical or multilamellar vesicles, SEAL showed around 10-fold enhancement of drug encapsulation efficiency compared with passive loading. Single-particle analysis by nano-flow cytometry was further employed to reveal the heterogeneous encapsulation behaviour of Dox-mEVs which would otherwise be overlooked by bulk-based approaches. Correlation analysis between doxorubicin auto-fluorescence and the fluorescence of a lipophilic dye DiD suggested that only the lipid-enclosed particles were actively loadable. Meanwhile, immunofluorescence analysis revealed that more than 85% of the casein positive particles was doxorubicin free. These findings further inspired the development of the lipid-probe- and immuno-mediated magnetic isolation techniques to selectively remove the contaminants of non-lipid enclosed particles and casein assemblies, respectively. Finally, the intracellular assessments confirmed the superior performance of SEAL-prepared mEV formulations, and demonstrated the impact of encapsulation heterogeneity on therapeutic outcome. The as-developed cargo-loading approach and nano-flow cytometry-based characterization method will provide an instructive insight in the development of EV-based delivery systems.

Epidemiology of Viruses Causing Pediatric Community Acquired Pneumonia in Shanghai During 2010-2020: What Happened Before and After the COVID-19 Outbreak?

INTRODUCTION

Since the global outbreak of COVID-19, there has been a significant reduction in pediatric outpatient and emergency visits for infectious diseases. The purpose of this study was to analyze the changes in respiratory viruses in children with community-acquired pneumonia (CAP) in Shanghai in the past 10 years, especially in the first year after COVID-19.

METHODS

We conducted a retrospective, observational study; the results for eight common respiratory viruses (respiratory syncytial virus (RSV), influenza virus A and B, parainfluenza virus 1-3 (PIV), adenovirus (ADV) and human metapneumovirus) tested by direct fluorescent antibody assays in hospitalized CAP cases in Children's Hospital of Fudan University during 2010-2020 were analyzed.

RESULTS

Of the 5544 hospitalized CAP patients included in this study, 20.2% (1125/5544) were positive for the eight respiratory viruses. The top three pathogens were RSV, PIV3 and ADV, detected from 9.8% (543/5544), 5.3% (294/5544) and 2.0% (111/5544) of the samples, respectively. RSV had the highest positive rates among children < 2 years old. In 2020, the detection rate of all viruses showed a sharp decline from February to August compared with the previous 9 years. When the Shanghai community reopened in August 2020, the detection rate of eight viruses rebounded significantly in September.

CONCLUSIONS

These eight respiratory viruses, especially RSV and PIV, were important pathogens of CAP in Shanghai children in the past 10 years. The COVID-19 pandemic had a significant impact on the detection rates for eight respiratory viruses in children with CAP in Shanghai.

A survey of a COVID-19 cluster of charter flight importation

OBJECTIVES

Although a number of cases of importation with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported, there are still no data available concerning the characteristics in the coronavirus disease 2019 (COVID-19) cluster of charter flight importation. Here, we provide an analysis of COVID-19 cases and their close contacts who worked for the same company on a project in Karbala, Iraq, and returned back to Chengdu, China, by a charter flight.

METHODS

The data of imported COVID-19 cases and their close contacts were obtained from National Notifiable Disease Report System of Chinese Center for Disease Control and Prevention and field epidemiological investigation reports by Centers for Disease Control and Prevention (CDCs) in Chengdu. The information of general characteristics and laboratory findings of this cluster were collected and summarized.

RESULTS

One hundred and six (66.67%) of 159 charter flight passengers tested positive for COVID-19 before entry. Through treatment, all 159 people tested negative and meet the requirements of taking flights bound for China before boarding. However, there has been still 36 (22.64%) of them tested positive after entry. The median time from entry to confirmation was 1.0 day (Interquartile Range (IQR): 0-4.3). The Cycle threshold value (Ct value) of 36 patients' positive samples are all above 30 and most values are above 35.

CONCLUSIONS

In conclusion, there is still a risk that a number of COVID-19 cases can be imported through charter flight. However, the infectivity of confirmed patients of the charter flight was considered to be low.

Impact of COVID-19 pandemic on the prevalence of respiratory viruses in children with lower respiratory tract infections in China

Background

The multifaceted non-pharmaceutical interventions (NPIs) taken during the COVID-19 pandemic not only decrease the spreading of the SARS-CoV-2, but have impact on the prevalence of other viruses. This study aimed to explore the prevalence of common respiratory viruses among hospitalized children with lower respiratory tract infections (LRTI) in China during the COVID-19 pandemic.

Methods

Respiratory specimens were obtained from children with LRTI at Children’s Hospital of Fudan University for detection of respiratory syncytial virus (RSV), adenovirus (ADV), parainfluenza virus (PIV) 1 to 3, influenza virus A (FluA), influenza virus B (FluB), human metapneumovirus (MPV) and rhinovirus (RV). The data were analyzed and compared between the year of 2020 (COVID-19 pandemic) and 2019 (before COVID-19 pandemic).

Results

A total of 7107 patients were enrolled, including 4600 patients in 2019 and 2507 patients in 2020. Compared with 2019, we observed an unprecedented reduction of RSV, ADV, FluA, FluB, and MPV infections in 2020, despite of reopening of schools in June, 2020. However, the RV infection was significantly increased in 2020 and a sharp increase was observed especially after reopening of schools. Besides, the PIV infection showed resurgent characteristic after September of 2020. The mixed infections were significantly less frequent in 2020 compared with the year of 2019.

Conclusions

The NPIs during the COVID-19 pandemic have great impact on the prevalence of common respiratory viruses in China. Meanwhile, we do need to be cautious of a possible resurgence of some respiratory viruses as the COVID-19 restrictions are relaxed.

Molecular and epidemiological characterization of human adenovirus and classic human astrovirus in children with acute diarrhea in Shanghai, 2017-2018

BACKGROUND

In addition to rotavirus and norovirus, human adenovirus (HAdV) and classic human astrovirus (classic HAstV) are important pathogens of acute diarrhea in infants and young children. Here, we present the molecular epidemiology of HAdV and classic HAstV in children with acute diarrhea in Shanghai.

METHODS

Fecal specimens were collected from 804 outpatient infants and young children diagnosed with acute diarrhea in Shanghai from January 2017 to December 2018. All of the samples were screened for the presence of HAdV and classic HAstV. HAdV and classic HAstV were detected using traditional PCR and reverse-transcription PCR, respectively. All of the HAdV and classic HAstV positive samples were genotyped by phylogenetic analysis.

RESULTS

Among the 804 fecal samples, 8.58% (69/804) of samples were infected with either HAdV or classic HAstV, and five were co-infected with two diarrhea viruses. The overall detection rates of HAdV and classic HAstV were 3.47% (28/804) and 5.22% (42/804), respectively. Four subgroups (A, B, C, and F) and seven genotypes (HAdV-C1, -C2, -B3, -C5, -A31, -F40, and -F41) of HAdV were detected. Subgroup F had the highest constituent ratio at 64.29% (18/28), followed by non-enteric HAdV of subgroup C (21.43%, 6/28) and subgroup B 10.71% (3/28). HAdV-F41 (60.71%, 17/28) was the dominant genotype, followed by HAdV-C2 (14.29%, 4/28) and HAdV-B3 (10.71%, 3/28). Two genotypes of classic HAstV (HAstV-1 and HAstV-5) were identified in 42 samples during the study period; HAstV-1 (95.24%, 40/42) was the predominant genotype, and the other two strains were genotyped as HAstV-5. No significant differences were found between boys and girls in the detection rates of HAdV (P = 0.604) and classic HAstV (P = 0.275). Over half of the HAdV infections (82.14%, 23/28) and classic HAstV infections (66.67%, 28/42) occurred in children less than 36 months. Seasonal preferences of HAdV and classic HAstV infections were summer and winter, respectively. In this study, the common clinical symptoms of children with acute diarrhea were diarrhea, vomiting, fever and abdominal pain.

CONCLUSIONS

Our findings indicate that HAdV and classic HAstV play important roles in the pathogenesis of acute diarrhea in children in Shanghai. Systematic and long-term surveillance of HAdV and classic HAstV are needed to monitor their prevalence in children and prevent major outbreak.

High-Throughput Human Telomere Length Analysis at the Single-Chromosome Level by FISH Coupled with Nano-Flow Cytometry

Telomere length (TL) is a highly relevant biomarker for age-associated diseases and cancer, yet its clinical applications have been hindered by the inability of existing methods to rapidly measure the TL distribution and the percentage of chromosomes with critically short telomeres (CSTs, < 3 kb). Herein, we report the development of a high-throughput method to measure TL at the single-chromosome level. Metaphase chromosomes are isolated, hybridized with the Alexa Fluor 488-labeled telomeric peptide nucleic acid probe, and analyzed using a laboratory-built ultrasensitive nano-flow cytometer. The fluorescence intensity of individual chromosomes is converted to TL in kilobases upon external calibration. With an analysis rate of several thousand chromosomes per minute, a statistically robust TL distribution histogram is acquired in minutes, and the percentage of chromosomes with CSTs can be quickly assessed. By analyzing peripheral blood lymphocytes of 158 healthy donors, TL is found to shorten with age at a rate of 64 ± 3 bp/year and the percentage of chromosomes with CSTs increases with age at a rate of 0.32 ± 0.02%/year. Moreover, the data of 28 patients with chronic myeloid leukemia (CML) indicate that telomeres are significantly shorter at the time of diagnosis and the clinical phases of CML are closely associated with TL and the percentage of chromosomes with CSTs. This powerful tool could greatly deepen our understanding of telomere biology and improve the clinical utility of telomere biomarkers.

General and mild modification of food-derived extracellular vesicles for enhanced cell targeting

Food-derived extracellular vesicles (FDEVs) have attracted increasing attention as potential delivery vehicles for therapeutic agents due to their desirable features such as excellent biocompatibility, easy accessibility and cost effectiveness. However, the intrinsic targeting capability of FDEVs is unsatisfactory compared to artificial nanoparticles or other source-derived EVs, which calls for efficient surface engineering strategies to equip them with specific ligands. Here we report a general and mild modification method via reduction of disulfide groups to maleimide reactive thiols. Taking milk-derived EVs (mEVs) as a model system, we demonstrated the feasibility for tethering various ligands on the surface without compromising the vesicular structures. Building an ultra-sensitive nano-flow cytometer (nFCM), the heterogeneous nature of the functionalized samples was revealed, and a magnetic separation approach was proposed accordingly to remove the as-observed non-EV particles. The cellular uptake and cytotoxicity experiments provided direct evidence showing an enhanced cell targeting and cargo delivery capability of the ligand conjugated mEVs. In addition, the in vivo imaging further proved the applicability of transferrin conjugation for increased tumor enrichment of mEVs. Collectively, this general and mild ligand conjugation method enables an efficient surface functionalization of FDEVs, which is of vital importance for enhanced targeting delivery.

Human cytomegalovirus envelope glycoprotein B, H, and N polymorphisms among infants of Shanghai area in China

Human cytomegalovirus (HCMV) is the leading cause of congenital infection and an opportunistic pathogen capable of establishing lifelong latency. In the present study, we aimed to investigate the distribution of glycoprotein B, H, and N in infants of Shanghai and correlate the genotype with active and latent HCMV infection. A total of 129 urine samples were collected between August 2014 and December 2015 from infants under 3 years with HCMV infection. Nested PCR was used to amplify the regions of UL55 (gB), UL75 (gH), and UL73 (gN). Gene sequencing and phylogenetic analyses were used to classify the genotypes. Overall, regarding gB, gB1 (57.27%) was predominant, followed by gB3 (41.82%) and gB4 (0.91%). gH1 (54.33%) was the most prevalent genotype of gH, followed by gH2 (45.67%). Concerning gN, we detected gN1 (17.44%), gN2 (2.33%), gN3a (29.07%), gN3b (8.14%), gN4a (13.95%), gN4b (15.12%), and gN4c (13.95%), among which gN3a was the dominant genotype. All the expected genotypes were present except gB2 in children with active infection: gB1 (56.25%), gB3 (42.5%), gB4 (1.25%), gH1 (58.70%), gH2 (41.30%), gN1 (19.05%), gN2 (3.17%), gN3a (25.40%), gN3b (6.35%), gN4a (15.87%), gN4b (17.46%), and gN4c (12.70%). However, among latent cases, we detected gB1 (60%), gB3 (40%), gH1 (42.86%), gH2 (57.14%), gN1 (13.04%), gN3a (39.13%), gN3b (13.04%), gN4a (8.70%), gN4b (8.70%), and gN4c (17.39%), respectively. gB2, gB4, and gN2 were absent in this group. The results revealed that gB1, gH1, and gN3a were predominant in the infants of Shanghai. gH showed different trends among children with active and latent infection.