Dynamic impact of delivery modes on gut microbiota in preterm infants hospitalized during the initial 4 weeks of life.

Preterm infants face a high risk of various complications, and their gut microbiota plays a pivotal role in health. Delivery modes have been reported to affect the development of gut microbiota in term infants, but its impact on preterm infants remains unclear. Here, we collected fecal samples from 30 preterm infants at five-time points within the first four weeks of life. Employing 16 S rRNA sequencing, principal coordinates analysis, the analysis of similarities, and the Wilcoxon rank-sum test, we examined the top dominant phyla and genera, the temporal changes in specific taxa abundance, and their relationship with delivery modes, such as Escherichia-Shigella and Enterococcus based on vaginal delivery and Pluralibacter related to cesarean section. Moreover, we identified particular bacteria, such as Taonella, Patulibacter, and others, whose proportions fluctuated among preterm infants born via different delivery modes at varying time points, as well as the microbiota types and functions. These results indicated the influence of delivery mode on the composition and function of the preterm infant gut microbiota. Importantly, these effects are time-dependent during the early stages of life. These insights shed light on the pivotal role of delivery mode in shaping the gut microbiota of preterm infants and have significant clinical implications for their care and management.

Effect of ß-lactam antibiotics on the gut microbiota of term neonates.

ß-Lactam antibiotics are a class of antibiotics commonly used to treat bacterial infections. However, the effects of ß-lactam antibiotics on term neonatal intestinal flora have not been fully elucidated. Hospitalized full-term newborns receiving ß-lactam antibiotics formed the antibiotic group (n = 67), while those without antibiotic treatment comprised the non-antibiotic group (n = 47). A healthy group included healthy full-term newborns (n = 16). Stool samples were collected for 16 S rDNA sequencing to analyze gut microbiota variations. Further investigation was carried out within the ß-lactam antibiotic group, exploring the effects of antibiotic use on the newborns' gut microbiota in relation to the duration and type of antibiotic administration, delivery method, and feeding practices. The antibiotic group exhibited significant difference of microbial community composition compared to the other groups. Genera like Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas were enriched, while Escherichia-Shigella, Clostridium sensu stricto 1, Bifidobacterium, and Parabacteroides were reduced. Klebsiella negatively correlated with Escherichia-Shigella, positively with Enterobacter, while Escherichia-Shigella negatively correlated with Enterococcus and Streptococcus. Regardless of neonatal age, ß-lactam antibiotics induced an elevated abundance of Klebsiella and Enterococcus. The impact on gut microbiota varied with the duration and type of antibiotic (cefotaxime or ampicillin/sulbactam). Compared to vaginal delivery, cesarean delivery after ß-lactam treatment heightened the abundance of Klebsiella, Enterobacteriaceae_Unclassified, Lactobacillales_Unclassified, and Pectobacterium. Feeding patterns minimally influenced ß-lactam-induced alterations. In conclusion, ß-lactam antibiotic treatment for neonatal pneumonia and sepsis markedly disrupted intestinal microbiota, favoring Klebsiella, Enterococcus, Streptococcus, Alistipes, and Aeromonas. The impact of ß-lactam varied by duration, type, and delivery method, emphasizing heightened disruptions post-cesarean delivery.

[Advances in nutritional support for children undergoing hematopoietic stem cell transplantation]. / é€ è¡€å¹²ç»†èƒžç§»æ¤å„¿ç«¥çš„è¥å »æ”¯æŒè¿›å±•.

Hematopoietic stem cell transplantation (HSCT) is a therapeutic option for various potentially life-threatening malignant and non-malignant diseases in children, such as malignancies, immunodeficiency syndromes, severe aplastic anemia, and inherited metabolic disorders. During transplantation, many factors can affect the nutritional status of the children, including radiotherapy, chemotherapy, gastrointestinal disorders, graft-versus-host disease, and medications. Malnutrition has been associated with decreased overall survival and increased complications in children undergoing HSCT, making nutritional support a crucial component of their management. However, currently, there is a lack of guidelines or consensus on nutritional support for children undergoing HSCT in China. Therefore, this review summarizes the progress in nutritional support for children undergoing HSCT, aiming to provide clinical guidance.

[Research progress of metabolomics in children with irritable bowel syndrome]. / ä»£è°¢ç»„å­¦åœ¨å„¿ç«¥è‚ æ˜“æ¿€ç»¼åˆå¾è¯Šæ²»ä¸­çš„ç ”ç©¶è¿›å±•.

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder characterized by symptoms such as abdominal pain, diarrhea, constipation, and indigestion. Given its unclear etiology and pathogenesis, and the absence of specific biomarkers, clinical diagnosis and treatment of IBS continue to pose significant challenges. In recent years, metabolomics technology, known for its non-invasive, high-throughput, high-precision, and highly reproducible features, has been widely applied in the diagnosis, treatment, and prognosis of various diseases. Therefore, metabolomics technology is expected to offer novel insights and methodologies for the biological mechanism research, diagnosis, and treatment of IBS. This article reviews recent advancements in the application of metabolomics to IBS, exploring its potential value in the clinical diagnosis and treatment of children with this condition.

cGAS-STING signaling pathway in gastrointestinal inflammatory disease and cancers.

Cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway has emerged as a key DNA-sensing machinery in innate immunity. Activation of cGAS-STING signaling pathway mediates the production of interferons and proinflammatory cytokines. Although cGAS-STING signaling pathway shows critical function in the maintenance of gut homeostasis, overactive cGAS-STING signaling pathway leads to gastrointestinal (GI) inflammation. Harnessing the effect and mechanism of the cGAS-STING signaling pathway could be beneficial for the development of novel strategies for the treatment of GI diseases. This review presents recent advances regarding the role of cGAS-STING signaling pathway in GI inflammatory disease and cancers and describes perspective therapeutic strategies targeting the signaling pathway.

Characteristics of intestinal microbiota in children with idiopathic short stature: a cross-sectional study.

Idiopathic short stature (ISS) accounts for more than 70% of childhood short stature cases, with an undefined etiology and pathogenesis, leading to limited treatment. However, recent studies have shown that intestinal microbiota may be associated with ISS. This study aimed to characterize the intestinal microbiota in children with ISS, effect of treatment with growth hormones, and association between specific bacterial species and ISS. This study enrolled 55 children, comprising 40 diagnosed with ISS at Jinhua Hospital, Zhejiang University, and 15 healthy controls. The subjects with ISS were divided into the untreated ISS group (UISS group, 22 children who had not been treated with recombinant human growth hormone [rhGH]), treated ISS group (TISS group, 18 children treated with rhGH for 1 year), and control group (NC group, 15 healthy children). High-throughput sequencing was used to determine the intestinal microbiota characteristics. Higher abundances of Bacteroides, Prevotella, Alistipes, Parabacteroides, Agathobacter and Roseburia were found in the UISS and TISS groups than in the control group, whereas Bifidobacterium, Subdoligranulum, and Romboutsia were less abundant. The composition of intestinal microbiota in the UISS and TISS groups was almost identical, except for Prevotella. The TISS group had significantly lower levels of Prevotella than did the UISS group, which were closer to those of the NC group. Receiver operating characteristic curve analysis revealed that the abundances of Prevotella, Bifidobacterium, Bacteroides, and Subdoligranulum were effective in differentiating between the UISS and NC groups. CONCLUSION: Alterations in intestinal microbiota may be associated with ISS. Specific bacterial species, such as Prevotella, may be potential diagnostic markers for ISS. WHAT IS KNOWN: • ISS is associated with the GH-IGF-1 axis. • Recent studies indicated an association between the GH-IGF-1 axis and intestinal microbiota. WHAT IS NEW: • Children with ISS showed alterations in intestinal microbiota, with a relative increase in the abundance of gut inflammation-related bacteria. • The relative abundances of Prevotella, Bacteroides, Bifidobacterium, and Subdoligranulum may serve as potential diagnostic markers.

Defects of parvalbumin-positive interneurons in the ventral dentate gyrus region are implicated depression-like behavior in mice.

Depression is an increasingly common but extremely serve mood disorder that remains poorly understood and inadequately treated. Fast-spiking parvalbumin-positive interneurons (PVIs), a subpopulation of GABAergic interneurons (GABA, g-aminobutyric acid), exhibit a widespread distribution throughout the hippocampus, and has been reported to play an important role in a variety of mental disorders. However, the relationship between depression and hippocampal PVIs remains unclear. Here in this present study, a series of experiments were conducted to clarify the potential relationship. Here, chronic unpredicted mild stress (CUMS) and Lipopolysaccharide (LPS) injection were introduced to induce depression-like behavior in mice, and led to a clear decline in PVIs numbers in the ventral hippocampal (vHPC), particularly in the ventral dentate gyrus (vDG) subfield. After a selectively removal of the PVIs in PV-ires-Cre::Ai14 mice, we confirmed that ablation of PVIs from the vDG induced depression-like behavior. Furthermore, we found that the removal of vDG-PVIs induced depression likely to be accounted for upregulation of neuroinflammation. These findings facilitate us better understand the role of hippocampal PVIs in depression.

Clinical analysis of asparaginase-associated pancreatitis in children.

OBJECTIVE: To investigate the clinical characteristics, diagnosis, and treatment of asparaginase-associated pancreatitis (AAP) in children to assess the risk factors of AAP and improve its clinical prognosis. METHODS: We performed a retrospective analysis of 24 patients with AAP who suffered from acute lymphoblastic leukemia (ALL) and received asparaginase chemotherapy, and who were admitted to the Children's Hospital of Zhejiang University School of Medicine from January 2009 to January 2019. We analyzed the general situation, drug application, clinical manifestations, laboratory tests, imaging findings, treatment, and prognosis. RESULTS: In 796 patients with ALL who received asparaginase chemotherapy, the incidence of AAP was 3% (24/796). Among these patients, 11 (45.8%) developed AAP during the first application of asparaginase during the induction of remission, six cases developed AAP during the second application of asparaginase, and seven cases developed AAP during the third and above application. The median time from the diagnosis of AAP in 24 patients to the last asparaginase treatment was 8 days (1-18 days), among whom, the main clinical symptoms were abdominal pain, vomiting, nausea, bloating, and fever, which accounted for 95.8%, 37.5%, 33.3%, 20.8%, 4.0%, and 42.7%, respectively. Additionally, seven patients had peritoneal effusion. At initial diagnosis, 62.5% of the patients (15/24) had an increase in blood amylase levels to more than three times the upper limit of normal. The abdominal ultrasound results of 91.7% (22/24) of the patients were consistent with the imaging changes observed in pancreatitis. All 24 patients immediately stopped asparaginase treatment and received symptomatic supportive treatment, including fluid resuscitation, fasting, nutritional support, antibiotics, pancreatin inhibitors, and treatment of complications, as needed. Twenty-three patients were relieved after treatment, and one died. Following the resolution of symptoms in 14 patients with AAP, asparaginase chemotherapy was reintroduced, and 3 patients relapsed with AAP, all of which were mild. Symptoms were relieved 72 h after stopping asparagine chemotherapy. CONCLUSION: According to the data from this single-center study, the incidence of AAP in patients with ALL was 3%, most of which occurred during the first or second exposure to asparaginase. Abdominal pain was the most common clinical manifestation. The diagnosis of AAP should be based on clinical manifestations, laboratory tests, and imaging findings. The prognosis of AAP is good, and whether asparaginase treatment can be reintroduced requires an evaluation of the benefits of asparaginase treatment and the risk of recurrence of pancreatitis.

Profound Hypothermia Concomitant With Severe Coagulation Dysfunction and Leukopenia in a Preterm Infant: A Case Report and Literature Review.

BACKGROUND: Neonatal hypothermia is common around the world; however, profound hypothermia is a very rare-but life-threatening-event. CLINICAL FINDINGS: This was a very rare case involving a 15-day old preterm infant diagnosed with profound hypothermia (rectal temperature, 27°C) concomitant with severe coagulation dysfunction and leukopenia on admission. PRIMARY DIAGNOSIS: Profound hypothermia together with severe coagulopathy, leukopenia, late-onset sepsis, and pneumonia. INTERVENTIONS: The patient was rewarmed slowly, with a rectal temperature rising at a rate of 0.5°C/h < R < 1°C/h. Vital signs were closely monitored. Coagulation factors were supplemented by intravenous infusion of fresh frozen plasma. Supportive treatment with intravenous infusion of immunoglobulin was provided, and antibiotics were used empirically. Nil per os and intravenous rehydration were also implemented. OUTCOMES: The condition of the preterm infant gradually improved and was successfully discharged. PRACTICE RECOMMENDATIONS: Profound hypothermia is very rare in preterm infants. However, once it occurs, it may be concomitant with severe coagulopathy and leukopenia. Successful management involves slow rewarming, prompt supplementation of coagulation factors, empirical antibiotics, and supportive treatment.

Role of Ion Channels in the Chemotransduction and Mechanotransduction in Digestive Function and Feeding Behavior.

The gastrointestinal tract constantly communicates with the environment, receiving and processing a wide range of information. The contents of the gastrointestinal tract and the gastrointestinal tract generate mechanical and chemical signals, which are essential for regulating digestive function and feeding behavior. There are many receptors here that sense intestinal contents, including nutrients, microbes, hormones, and small molecule compounds. In signal transduction, ion channels are indispensable as an essential component that can generate intracellular ionic changes or electrical signals. Ion channels generate electrical activity in numerous neurons and, more importantly, alter the action of non-neurons simply and effectively, and also affect satiety, molecular secretion, intestinal secretion, and motility through mechanisms of peripheral sensation, signaling, and altered cellular function. In this review, we focus on the identity of ion channels in chemosensing and mechanosensing in the gastrointestinal tract.

[Development and thoughts of digestive endoscopy in children]. / å„¿ç«¥æ¶ˆåŒ–å† é•œçš„å‘å±•ä¸Žæ€è€ƒ.

After nearly 40 years of development, digestive endoscopy in children has been widely applied, and it has helped to expand the spectrum of pediatric digestive system diseases and greatly improve the diagnosis and treatment of pediatric digestive system diseases. Pediatric digestive endoscopy has become a subject. However, there are some problems such as the unbalanced development of pediatric digestive endoscopy across China, the lack of homogeneity in diagnosis and treatment system, the tendency of adult-oriented diagnosis and treatment techniques, and the localization of training quality, which affect the standardized and healthy development of pediatric digestive endoscopy. The diagnosis and treatment with digestive endoscopy in children should adhere to both pediatric characteristics and technological innovation to propose the concept of comfort, emphasize the importance of standardization (including the space and process for endoscopic diagnosis and treatment, perioperative evaluation, training mode, and access qualification), standardize the minimally invasive techniques, and develop artificial intelligence. It is of great importance to formulate related consensus statements and guidelines on the basis of medical safety and the features of the growth and development of children, so as to achieve the high-quality development of pediatric digestive endoscopy, effectively improve the diagnosis and treatment levels of pediatric digestive endoscopy, and bring benefits to more pediatric patients.

Exploratory Investigation of Intestinal Structure and Function after Stroke in Mice.

Stroke is the second leading cause of death worldwide. Patients who have a stroke are susceptible to many gastrointestinal (GI) complications, such as dysphagia, GI bleeding, and fecal incontinence. However, there are few studies focusing on the GI tract after stroke. The current study is to investigate the changes of intestinal structure and function in mice after ischemic stroke. Ischemic stroke was made as a disease model in mice, in which brain and ileal tissues were collected for experiments on the 1st and 7th day after stroke. Intestinal motility of mice was inhibited, and intestinal permeability was increased after stroke. Hematoxylin-eosin (HE) staining showed the accumulation of leucocytes in the intestinal mucosa. Myeloperoxidase (MPO) activity and inflammatory proteins (nuclear factor kappa-B (NF-κB), inducible nitric oxide synthase (iNOS)) in the small intestine were significantly increased in mice after stroke. The expression of tight junction (TJ) proteins (zonula occludens-1 (ZO-1), occludin, and claudin-1) was downregulated, and transmission electron microscopy (TEM) showed broken TJ of the intestinal mucosa after stroke. Glial fibrillary acidic protein (GFAP) and the apoptosis-associated proteins (tumor necrosis factor (TNF-α), caspase-3, and cleaved caspase-3) were notably upregulated as well. Ischemic stroke led to negative changes on intestinal structure and function. Inflammatory mediators and TNF-α-induced death receptor signaling pathways may be involved and disrupt the small intestinal barrier function. These results suggest that stroke patients should pay attention to GI protection.

[Role of vitamin D in pediatric irritable bowel syndrome].

Irritable bowel syndrome (IBS) is a common functional gastrointestinal disease in children and has the clinical manifestations of recurrent abdominal pain with the changes in defecation frequency or stool form. Many studies have shown that children with IBS have a significantly lower vitamin D level than the healthy population, and vitamin D supplementation can significantly improve the clinical symptoms and quality of life of the children, suggesting that vitamin D supplementation may play a role in the treatment of IBS. This article reviews the association between vitamin D and IBS in children and elaborates on the possible mechanism of action of vitamin D.

What dose of aspirin should be used in the initial treatment of Kawasaki disease? A meta-analysis.

OBJECTIVE: The use of IVIG plus high- or low-dose aspirin for the initial treatment of Kawasaki disease remains controversial. The aim of this study was to evaluate the efficacy of IVIG plus high-dose aspirin compared with IVIG plus low-dose aspirin in the treatment of Kawasaki disease. METHODS: Studies related to aspirin therapy for Kawasaki disease were selected by searching the databases of Medline (PubMed), Embase and the Cochrane Library before March 2019. Statistical analyses were performed by using a Review Manager Software package and STATA v.15.1. RESULTS: Eight retrospective cohort studies, characterizing 12 176 patients, were analysed. Overall, no significant difference was found in the incidence of coronary artery abnormalities between the high- and low-dose aspirin groups [relative risk (RR) 1.15; 95% CI: 0.93, 1.43; P = 0.19; random-effects model]. The patients treated with high-dose aspirin had slightly faster resolution of fever [mean difference (MD) -0.30; 95% CI: -0.58, -0.02; P = 0.04; random-effects model]. but the rates of IVIG resistance (RR, 1.26; 95% CI: 0.55, 2.92; P = 0.59; random-effects model) and days in hospital (MD, 0.22; 95% CI: -0.93, 1.37; P = 0.71; random-effects model) were similar between the two groups. CONCLUSION: Low-dose aspirin plus IVIG might be as effective as high-dose aspirin plus IVIG for the initial treatment of Kawasaki disease. Considering that high-dose aspirin may cause more adverse reactions than low-dose aspirin, low-dose aspirin plus IVIG should be recommended as the first-line therapy in the initial treatment of Kawasaki disease.

Application of gene chip technology in the diagnostic and drug resistance detection of Helicobacter pylori in children.

BACKGROUND AND AIMS: Helicobacter pylori (HP) culture for diagnosing HP infection is time-consuming and technologically complex. This study evaluated the clinical significance of gastric mucosal gene chip technology in the rapid diagnosis of HP infection and detection of drug resistance in children. METHODS: Patients (between the age of 2.5 and 16.0 years old) manifesting gastrointestinal symptoms were enrolled in this study. HP culture of gastric mucosa and drug sensitivity test were performed. A gene chip of gastric mucosa was used to detect the presence of HP infection, some single nucleotide polymorphisms in HP drug resistance genes, or associated gene mutation. DNA sequencing was investigated and compared with the gene chip test results. RESULTS: Out of 267 cases, HP culture was positive in 169 cases and negative in 98 cases. HP detection by the gene chip method was positive in 208 cases and negative in 59 cases. The sensitivity, specificity, and accuracy of the gene chip technology for diagnosing HP infection were 96.1, 85.0, and 93.6%, respectively. HP resistance gene locus using the gene chip showed the main mutation locus of clarithromycin to be 2143A/G, levofloxacin at locus GyrA 91 and GyrA 87, and amoxicillin at PBP1 556ser. Concordance rates between gene chip and DNA sequencing for VacA-S/M, 16S rRNA, 23S rRNA, and GyrA were greater than 95%, and that of PBP1 was greater than 82%. CONCLUSION: Gastric mucosal gene chip technology can be used for rapid diagnosis and drug resistance detection of HP infection in children.

Analysis of risk factors and development of scoring system to predict severity of upper gastrointestinal bleeding in children.

BACKGROUND AND AIM: Upper gastrointestinal bleeding is a rare and potentially life-threatening condition in children. Herein, clinical features and risk factors in children with upper gastrointestinal bleeding were analyzed, and a clinical scoring system was constructed to assess severity. METHODS: This retrospective cohort study involved 224 children hospitalized with upper gastrointestinal bleeding between January 2012 and April 2018. Demographic data, clinical information, and laboratory test results on admission were statistically examined. RESULTS: Out of 224 upper gastrointestinal bleeding cases, 76 were diagnosed as severe and 148 as mild cases according to the rate of blood loss and severity. Severe group was significantly different from mild group in 23 items including age, number of patients aged more than 7 years, and so forth (P < 0.01 or P < 0.05). Positive detection rate of bleeding etiology was gradually decreased (P < 0.01) in relation to delay in timing of endoscopy. Analysis of logistic regression evinced five independent risk factors for severe cases to be associated with poor consciousness, hemoglobin < 80 g/L, hemoglobin drop of > 20 g/L, hematochezia, and anemic appearance (P < 0.01 or P < 0.05). Using these five parameters, a number of scoring models were tested. The most predictive resulted in a scoring system constructed with a total of 16 and a cutoff for intervention of 8. CONCLUSIONS: Amalgamation of risk factors with the scoring system plays an important role in assessing upper gastrointestinal bleeding severity in children.

Comparative mouse lung injury by nickel nanoparticles with differential surface modification.

BACKGROUND: Previous studies have demonstrated that exposure to nickel nanoparticles (Nano-Ni) causes oxidative stress and severe, persistent lung inflammation, which are strongly associated with pulmonary toxicity. However, few studies have investigated whether surface modification of Nano-Ni could alter Nano-Ni-induced lung injury, inflammation, and fibrosis in vivo. Here, we propose that alteration of physicochemical properties of Nano-Ni through modification of Nano-Ni surface may change Nano-Ni-induced lung injury, inflammation, and fibrosis. METHODS: At first, dose-response and time-response studies were performed to observe lung inflammation and injury caused by Nano-Ni. In the dose-response studies, mice were intratracheally instilled with 0, 10, 20, 50, and 100 µg per mouse of Nano-Ni and sacrificed at day 3 post-exposure. In the time-response studies, mice were intratracheally instilled with 50 µg per mouse of Nano-Ni and sacrificed at days 1, 3, 7, 14, 28, and 42 post-instillation. At the end of the experiment, mice were bronchoalveolar lavaged (BAL) and the neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BAL fluid (BALF) were determined. In the comparative studies, mice were intratracheally instilled with 50 µg per mouse of Nano-Ni or with the same molar concentration of Ni as Nano-Ni of either partially [O]-passivated Nano-Ni (Nano-Ni-P) or carbon-coated Nano-Ni (Nano-Ni-C). At day 3 post-exposure, BAL was performed and the above cellular and biochemical parameters in the BALF were analyzed. The MMP-2/9 protein levels and activities in the BALF and mouse lung tissues were also determined. Mouse lung tissues were also collected for H&E staining, and measurement of thiobarbituric acid reactive substances (TBARS) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the genomic DNA. At day 42 post-exposure, mouse right lung tissues were collected for H&E and Trichrome stainings, and left lung tissues were collected to determine the hydroxyproline content. RESULTS: Exposure of mice to Nano-Ni resulted in a dose-response increase in acute lung inflammation and injury reflected by increased neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BALF. The time-response study showed that Nano-Ni-induced acute lung inflammation and injury appeared as early as day 1, peaked at day 3, and attenuated at day 7 post-instillation. Although the neutrophil count, CXCL1/KC level, LDH activity, and concentration of total protein in the BALF dramatically decreased over the time, their levels were still higher than those of the controls even at day 42 post-exposure. Based on the results of the dose- and time-response studies, we chose a dose of 50 µg per mouse of Nano-Ni, and day 3 post-exposure as short-term and day 42 post-exposure as long-term to compare the effects of Nano-Ni, Nano-Ni-P, and Nano-Ni-C on mouse lungs. At day 3 post-exposure, 50 µg per mouse of Nano-Ni caused acute lung inflammation and injury that were reflected by increased neutrophil count, CXCL1/KC level, LDH activity, concentration of total protein, and MMP-2/9 protein levels and activities in the BALF. Nano-Ni exposure also caused increased MMP-2/9 activities in the mouse lung tissues. Histologically, infiltration of large numbers of neutrophils and macrophages in the alveolar space and interstitial tissues was observed in mouse lungs exposed to Nano-Ni. Nano-Ni-P exposure caused similar acute lung inflammation and injury as Nano-Ni. However, exposure to Nano-Ni-C only caused mild acute lung inflammation and injury. At day 42 post-exposure, Nano-Ni caused extensive interstitial fibrosis and proliferation of interstitial cells with inflammatory cells infiltrating the alveolar septa and alveolar space. Lung fibrosis was also observed in Nano-Ni-P-exposed lungs, but to a much lesser degree. Only slight or no lung fibrosis was observed in Nano-Ni-C-exposed lungs. Nano-Ni and Nano-Ni-P, but not Nano-Ni-C, caused significantly elevated levels of TBARS in mouse lung tissues and 8-OHdG in mouse lung tissue genomic DNA, suggesting that Nano-Ni and Nano-Ni-P induce lipid peroxidation and oxidative DNA damage in mouse lung tissues, while Nano-Ni-C does not. CONCLUSION: Our results demonstrate that short-term Nano-Ni exposure causes acute lung inflammation and injury, while long-term Nano-Ni exposure causes chronic lung inflammation and fibrosis. Surface modification of Nano-Ni alleviates Nano-Ni-induced pulmonary effects; partially passivated Nano-Ni causes similar effects as Nano-Ni, but the chronic inflammation and fibrosis were at a much lesser degree. Carbon coating significantly alleviates Nano-Ni-induced acute and chronic lung inflammation and injury.

Ultrasonic Control of Neural Activity through Activation of the Mechanosensitive Channel MscL.

Externally controlling the excitation of a neuronal subset through ion channels activation can modulate the firing pattern of an entire neural circuit in vivo. As nanovalves in the cell membrane, ion channels can be opened by light (optogenetics) or ultrasonic (sonogenetics) means. A thoroughly analyzed force sensor is the Escherichia coli mechano sensitive channel of large conductance (MscL). Here we expressed MscL in rat hippocampal neurons in a primary culture and showed that it could be activated by low-pressure ultrasound pulses. The gain-of-function mutation, I92L, sensitized MscL's sonic response, triggering action potentials at a peak negative pressure as low as 0.25 MPa. Further, the I92L MscL reliably elicited individual spikes by timed brief pulses, making excitation programmable. Because MscL opens to tension in the lipid bilayer, requiring no other proteins or ligands, it could be developed into a general noninvasive sonogenetic tool to manipulate the activities of neurons or other cells and potential nanodevices.

[Age distribution characteristics of intestinal segmented filamentous bacteria and their relationship with intestinal mucosal immunity in children].

OBJECTIVE: To investigate the age distribution characteristics of intestinal segmented filamentous bacteria (SFB) in children and their relationship with intestinal mucosal immunity. METHODS: The fresh feces of 177 children and the ileocecal fluid of 47 children during colonoscopy were collected. The SFB was determined by real-time PCR. The concentration of secretory immunoglobulin A (sIgA) was determined by enzyme-linked immunosorbent assay. The numbers of interleukin 17A (IL-17A) cells and intraepithelial lymphocytes in the terminal ileum mucosa and the expression of transcription factors associated with the differentiation of T helper (Th) cells, T-box transcription factor (T-bet), forkhead box P3 (FOXP3), and retinoid-related orphan receptor gamma t (ROR-γt), were determined by immunohistochemistry. RESULTS: The positive rate of intestinal SFB in these children was 19.2% (34/177). Trend analysis showed that the positive rate of SFB was correlated with age: the rates for children aged 0-, 1-, 2-, 3-, 4-, 5-, 6-, and 7-15 years were 40%, 47%, 32%, 15%, 12%, 13%, 15% and 4% respectively (P<0.001). The concentration of sIgA in intestinal fluid was significantly higher in SFB-positive children (n=24) than in SFB-negative children (n=23) (P<0.01). The number of intraepithelial lymphocytes in the terminal ileum mucosa and the expression of T-bet, FOXP3, and ROR-γt were not significantly different between the SFB-positive group (n=12) and the SFB-negative group (n=11), but the number of IL-17A cells in the terminal ileum mucosa was significantly lower in the SFB-positive group than in the SFB-negative group (P<0.05). CONCLUSIONS: Intestinal SFB colonization in children is age-related, and the colonization rate is relatively high in children under 3 years old. In SFB-positive children, the secretion of intestinal sIgA is increased, while the number of IL-17A cells in the terminal ileum is reduced.

Antibiotics resistance of Helicobacter pylori in children with upper gastrointestinal symptoms in Hangzhou, China.

BACKGROUND: The decreasing eradication rate of Helicobacter pylori is mainly because of the progressive increase in its resistance to antibiotics. Studies on antimicrobial susceptibility of H. pylori in children are limited. This study aimed to investigate the resistance rates and patterns of H. pylori strains isolated from children. MATERIALS AND METHODS: Gastric mucosa biopsy samples obtained from children who had undergone upper gastrointestinal endoscopy were cultured for H. pylori, and susceptibility to six antibiotics (clarithromycin, amoxicillin, gentamicin, furazolidone, metronidazole, and levofloxacin) was tested from 2012-2014. RESULTS: A total of 545 H. pylori strains were isolated from 1390 children recruited. The total resistance rates of H. pylori to clarithromycin, metronidazole, and levofloxacin were 20.6%, 68.8%, and 9.0%, respectively. No resistance to amoxicillin, gentamicin, and furazolidone was detected. 56.1% strains were single resistance, 19.6% were resistant to more than one antibiotic, 16.7% for double resistance, and 2.9% for triple resistance in 413 strains against any antibiotic. And the H. pylori resistance rate increased significantly from 2012-2014. There was no significant difference in the resistance rates to clarithromycin, metronidazole, and levofloxacin between different gender, age groups, and patients with peptic ulcer diseases or nonulcer diseases. CONCLUSIONS: Antibiotic resistance was indicated in H. pylori strains isolated from children in Hangzhou, and it increased significantly during the 3 years. Our data strongly support current guidelines, which recommend antibiotic susceptibility tests prior to eradication therapy.