Characteristics of the Cajal interstitial cells and intestinal microbiota in children with refractory constipation.

BACKGROUND: Children with refractory constipation experience intense and persistent symptoms that greatly diminish their quality of life. However, the underlying pathophysiological mechanism responsible for this condition remains uncertain. Our objective was to evaluate characteristics of colonic motor patterns and interstitial cells of Cajal (ICCs) to refractory constipation children, as well as intestinal microbiota compositions. METHODS: Colonic manometry (CM) was conducted on a cohort of 30 patients with refractory constipation to assess colonic motility, and 7 of them underwent full-thickness colon biopsy specimens. Another 5 colonic specimens from nonconstipation patients were collected to identify the ICCs by immunohistochemistry. Fecal samples from 14 children diagnosed with refractory constipation and subjecting 28 age-matched healthy children to analysis using high-throughput sequencing of 16S rRNA. RESULTS: According to CM results, dividing 30 children with refractory constipation into 2 groups: normal group (n = 10) and dysmotility group (n = 20). Dysmotility subjects showed lower colonic motility. Antegrade propagating pressure waves, retrograde propagating pressure waves, and periodic colonic motor activity were common in normal subjects and rare in dysmotility subjects (32.7 ± 8.9 vs 20.7 ± 13.0/17 h, P < 0.05, 11.5 ± 2.3 vs 9.6 ± 2.3/17 h, P < 0.05, and 5.2 ± 8.9 vs 3.5 ± 6.8 cpm, P < 0.005, respectively), whereas periodic rectal motor activity was more common in dysmotility subjects (3.4 ± 4.8 vs 3.0 ± 3.1 cpm, P < 0.05). Dysmotility subjects exhibited a significantly greater number of preprandial simultaneous pressure waves compared to the normal subjects (32.3 ± 25.0 vs 23.6 ± 13.2/1 h, P < 0.005). Dysmotility subjects displayed a notable decrease in postprandial count of antegrade propagating pressure waves and high amplitude propagating pressure waves when compared to normal subjects (3.9 ± 2.9 vs 6.9 ± 3.5/1 h and 2.3 ± 1.5 vs 5.4 ± 2.9/1 h, respectively, P < 0.05). The number, distribution, and morphology of ICCs were markedly altered in refractory constipation compared children to the controls (P < 0.05). Children diagnosed with refractory constipation displayed a distinct dissimilarity in composition of their intestinal microbiota comparing with control group (P < 0.005). In genus level, Bacteroidetes represented 34.34% and 43.78% in the refractory constipation and control groups, respectively. Faecalibacterium accounted for 3.35% and 12.56%, respectively (P < 0.005). Furthermore, the relative abundances of Faecalibacterium (P < 0.005), Lachnospira (P < 0.05), and Haemophilus (P < 0.05) significantly decreased, whereas those of Parabacteroides (P < 0.05), Alistipes (P < 0.005), Prevotella_2 (P < 0.005), [Ruminococcus]_torques_group (P < 0.005), Barnesiella (P < 0.05), Ruminococcaceae_UCG-002 (P < 0.005), and Christensensenellaceae_R-7_group (P < 0.05) were markedly increased in children with refractory constipation. CONCLUSIONS: Dysmotility subjects showed lower colonic motility and an impaired postprandial colonic response. The decreased number and abnormal morphology of colonic ICCs may contribute to the pathogenesis of refractory constipation. Children with refractory constipation exhibited significant variations in microbiota composition across various taxonomic levels compared to the healthy control group. Our findings contribute valuable insights into pathophysiological mechanism underlying refractory constipation and provide evidence to support the exploration of novel therapeutic strategies for affected children.

Deep learning-driven multi-view multi-task image quality assessment method for chest CT image.

BACKGROUND: Chest computed tomography (CT) image quality impacts radiologists' diagnoses. Pre-diagnostic image quality assessment is essential but labor-intensive and may have human limitations (fatigue, perceptual biases, and cognitive biases). This study aims to develop and validate a deep learning (DL)-driven multi-view multi-task image quality assessment (M[Formula: see text]IQA) method for assessing the quality of chest CT images in patients, to determine if they are suitable for assessing the patient's physical condition. METHODS: This retrospective study utilizes and analyzes chest CT images from 327 patients. Among them, 1613 images from 286 patients are used for model training and validation, while the remaining 41 patients are reserved as an additional test set for conducting ablation studies, comparative studies, and observer studies. The M[Formula: see text]IQA method is driven by DL technology and employs a multi-view fusion strategy, which incorporates three scanning planes (coronal, axial, and sagittal). It assesses image quality for multiple tasks, including inspiration evaluation, position evaluation, radiation protection evaluation, and artifact evaluation. Four algorithms (pixel threshold, neural statistics, region measurement, and distance measurement) have been proposed, each tailored for specific evaluation tasks, with the aim of optimizing the evaluation performance of the M[Formula: see text]IQA method. RESULTS: In the additional test set, the M[Formula: see text]IQA method achieved 87% precision, 93% sensitivity, 69% specificity, and a 0.90 F1-score. Extensive ablation and comparative studies have demonstrated the effectiveness of the proposed algorithms and the generalization performance of the proposed method across various assessment tasks. CONCLUSION: This study develops and validates a DL-driven M[Formula: see text]IQA method, complemented by four proposed algorithms. It holds great promise in automating the assessment of chest CT image quality. The performance of this method, as well as the effectiveness of the four algorithms, is demonstrated on an additional test set.

Retrospective analysis of pediatric patients with multiple rare-earth magnets ingestion: a single-center experience from China.

BACKGROUND: The aim of this study was to characterize patients who ingested multiple rare-earth magnets, reveal the harm of rare-earth magnet foreign bodies in the digestive tract, and develop a clinical management algorithm. METHODS: This was a retrospective review of patients with rare-earth magnet foreign bodies in the digestive tract admitted to a university-affiliated pediatric medical center in China, between January 2016 and December 2019; the subset of medical data evaluated included clinical symptoms, signs, treatments and outcomes. RESULTS: A total of 51 cases were included in this study, including 36(70.6%) males and 15(29.4%) females. The magnets were passed naturally in 24(47.1%) patients and removed by intervention in 27(52.9%) patients, including 5(9.8%) cases by endoscopy and 22(43.1%) cases by surgery. Twenty-two (43.1%)cases had gastrointestinal obstruction, perforation, and fistula. Compared with the non-surgical group, the time of the surgical group from ingestion to arriving at the hospital was longer([80(5-336) vs 26(2-216)]hours, p < 0.001) while there was no significant difference in the mean age or the number of magnets swallowed. CONCLUSIONS: Magnets are attractive to children, but lead to catastrophic consequences including gastrointestinal obstruction, perforation, and surgical interventions when ingested multiple magnets. Endoscopic resection should be urgently performed in the presence of multiple magnets as early as possible within 24 h, even in asymptomatic patients.

Study of the association between histo-blood group antigens and norovirus infection in Chinese children.

Human caliciviruses (HuCVs) have been recognized as a major cause of sporadic viral diarrhea in children, among which norovirus genotype GII.4 is the most prevalent genotype. Stool and saliva samples were collected from 295 children with acute diarrhea and 150 asymptomatic children at a hospital in China. The HuCV detection rate was 10.85% (32/295) among the children with acute diarrhea, and all of these 32 children were either HBGA secretors (12/32) or partial secretors (20/32). HuCV was detected in two (1.33%) of the 150 samples obtained from the asymptomatic children. Of the norovirus-GII.3-positive children, 60% had blood type O, but only 17.29% of the symptomatic patients had blood type O, indicating that type O individuals could be at higher risk of GII.3 infection. However, due to the limited number of individuals in this study, further studies with a larger number of subjects should be conducted to verify this hypothesis.

A deep learning-based automatic image quality assessment method for respiratory phase on computed tomography chest images.

Background: Computed tomography (CT) chest scans have become commonly used in clinical diagnosis. Image quality assessment (IQA) for CT images plays an important role in CT examination. It is worth noting that IQA is still a manual and subjective process, and even experienced radiologists make mistakes due to human limitations (fatigue, perceptual biases, and cognitive biases). There are also kinds of biases because of poor consensus among radiologists. Excellent IQA methods can reliably give an objective evaluation result and also reduce the workload of radiologists. This study proposes a deep learning (DL)-based automatic IQA method, to assess whether the image quality of respiratory phase on CT chest images are optimal or not, so that the CT chest images can be used in the patient's physical condition assessment. Methods: This retrospective study analysed 212 patients' chest CT images, with 188 patients allocated to a training set (150 patients), validation set (18 patients), and a test set (20 patients). The remaining 24 patients were used for the observer study. Data augmentation methods were applied to address the problem of insufficient data. The DL-based IQA method combines image selection, tracheal carina segmentation, and bronchial beam detection. To automatically select the CT image containing the tracheal carina, an image selection model was employed. Afterward, the area-based approach and score-based approach were proposed and used to further optimize the tracheal carina segmentation and bronchial beam detection results, respectively. Finally, the score about the image quality of the patient's respiratory phase images given by the DL-based automatic IQA method was compared with the mean opinion score (MOS) given in the observer study, in which four blinded experienced radiologists took part. Results: The DL-based automatic IQA method achieved good performance in assessing the image quality of the respiratory phase images. For the CT sequence of the same patient, the DL-based IQA method had an accuracy of 92% in the assessment score, while the radiologists had an accuracy of 88%. The Kappa value of the assessment score between the DL-based IQA method and radiologists was 0.75, with a sensitivity of 85%, specificity of 91%, positive predictive value (PPV) of 92%, negative predictive value (NPV) of 93%, and accuracy of 88%. Conclusions: This study develops and validates a DL-based automatic IQA method for the respiratory phase on CT chest images. The performance of this method surpassed that of the experienced radiologists on the independent test set used in this study. In clinical practice, it is possible to reduce the workload of radiologists and minimize errors caused by human limitations.

Roxadustat ameliorates experimental colitis in mice by regulating macrophage polarization through increasing HIF level.

BACKGROUND: Gastro-intestinal (GI) tract inflammation is as a result of inflammatory hypoxia which is also induced by long-standing group of disorders like inflammatory-bowel disease (IBD). Regulation of GI immune homeostasis by macrophage involves hypoxia-inducible factor (HIF). As inhibitor of HIF prolyl hydroxylase, roxadustat (ROX) increases the levels of HIF. METHODS: We induced experimental colitis (EC) model in mice via dextran-sulfate sodium (DSS) to evaluate ROX role in above-mentioned disease. RESULTS: ROX ameliorated EC in mice by blocking colonic length shorten and loss of body weight, thereby reducing scores of disease-activity index (DAI) and histopathology. ROX significantly reduced inflammatory cytokines levels, suppressed M1 and increased M2 macrophage polarization in colonic tissues. Besides, ROX blocked declining hematocrit (HCT) level in blood and increased HIF-1-α and HIF-2-α level in colonic tissues. The inhibitor of HIF-1- α, KC7F2 decreased body weight and colonic length in ROX-treated DSS mice. Meanwhile, DAI scores and histopathology in KC7F2 treated DSS mice were markedly higher than that of treatment with ROX alone. KC7F2 treatments also significantly increased inflammatory cytokines levels, respectively promoted and reduced polarization of M1 and M2 macrophages in colonic tissue from ROX treated mice. Further, KC7F2 treatments inhibited ROX induced HCT level increasing in blood and decreased HIF-1-α and HIF-2-α level in colonic tissue. CONCLUSION: Collectively, we discovered that ROX ameliorated EC in mice by regulating macrophage polarization through promotion of HIF expression. GENERAL SIGNIFICANCE: Taken together, we developed a new application of ROX, which provides new ideas and a scientific basis for IBD treatment.

Diagnostic yield and novel candidate genes by next generation sequencing in 166 children with intrahepatic cholestasis.

BACKGROUND AND AIMS: Cholestatic liver disease is a leading referral to pediatric liver transplant centers. Inherited disorders are the second most frequent cause of cholestasis in the first month of life. METHODS: We retrospectively characterized the genotype and phenotype of 166 participants with intrahepatic cholestasis, and re-analyzed phenotype and whole-exome sequencing (WES) data from patients with previously undetermined genetic etiology for newly published genes and novel candidates. Functional validations of selected variants were conducted in cultured cells. RESULTS: Overall, we identified disease-causing variants in 31% (52/166) of our study participants. Of the 52 individuals, 18 (35%) had metabolic liver diseases, 9 (17%) had syndromic cholestasis, 9 (17%) had progressive familial intrahepatic cholestasis, 3 (6%) had bile acid synthesis defects, 3(6%) had infantile liver failure and 10 (19%) had a phenocopy of intrahepatic cholestasis. By reverse phenotyping, we identified a de novo variant c.1883G > A in FAM111B of a case with high glutamyl transpeptidase (GGT) cholestasis. By re-analyzing WES data, two patients were newly solved, who had compound heterozygous variants in recently published genes KIF12 and USP53, respectively. Our additional search for novel candidates in unsolved WES families revealed four potential novel candidate genes (NCOA6, CCDC88B, USP24 and ATP11C), among which the patients with variants in NCOA6 and ATP11C recapitulate the cholestasis phenotype in mice models. CONCLUSIONS: In a single-center pediatric cohort, we identified monogenic variants in 22 known human intrahepatic cholestasis or phenocopy genes, explaining up to 31% of the intrahepatic cholestasis patients. Our findings suggest that re-evaluating existing WES data from well-phenotyped patients on a regular basis can increase the diagnostic yield for cholestatic liver disease in children.

Prevalence of adenovirus in children with acute respiratory tract infection in Lanzhou, China.

BACKGROUND: Human adenovirus (HAdV) is an important agent causing respiratory tract infection in children. Information on the epidemiological and clinical features of HAdV is limited in children with acute respiratory tract infections (ARTIs) in China, especially those of a novel genotype, Ad55. METHODS: In total, 1169 nasopharyngeal aspirates were collected from children younger than 14 years with ARTIs between November 2006 and November 2009. The polymerase chain reaction (PCR) was used to screen HAdVs. All PCR-positive products were sequenced. RESULTS: 74 of 1169 (6.33%) specimens were positive for HAdVs. Among positive cases, AdV3 (58/74) was detected most frequently, followed by AdV11 (10/74), AdV2 (2/74), AdV7 (2/69), AdV6 (1/74), and AdV1 (1/74). AdV55 was found in one case. The incidence of HAdV infection peaked in children aged 3-7 years. The most common clinical diagnosis was upper respiratory infection, and the most common syndrome was fever and cough.The comparison of HAdV and RSV group revealed that Children infected with group AdV were significant older than children infected with group RSV, had more fever but less frequently wheezing, and cough, crackles, and cyanosis, The duration of hospitalization between the AdV group and RSV group was not significant, but a greater frequency of LRTIs was observed in RSV group. CONCLUSIONS: HAdV is an important viral agent in children with ARTIs in Lanzhou City, China. Multiple HAdV serotypes co-circulated with Ad3, which was predominant in this 3-year study. The novel AdV55 genotype was found in one case. No fixed seasonal rhythm could be identified.

Multiple uremic tumoral calcinosis in periarticular soft tissues with chronic renal failure: a case report.

Uremic tumoral calcinosis (UTC) is an uncommon and severe complication of hemodialysis therapy. The most important pathogenic factor involved in UTC is an increase in calcium-phosphorus products. We report here a patient undergoing hemodialysis for renal failure caused by hypertensive nephropathy who presented multiple UTCs in the right shoulder, left elbow and wrist. After surgical excision, they all recurred, with a similar UTC in the left shoulder. By observing the imaging features of various imaging examinations during the whole period of this case, including X-ray, computed tomography (CT), magnetic resonance imaging (MRI), and single-photon emission computed tomography (SPECT), we highlight the importance of imaging for evaluating the state of UTC regarding treatment options, further deepening our understanding of the imaging manifestations for this disease and their clinical significance.

Intrinsic apoptosis and cytokine induction regulated in human tonsillar epithelial cells infected with enterovirus A71.

Enterovirus A71 (EV-A71) has emerged as a clinically important neurotropic virus following poliovirus eradication. Recent studies have shown that human tonsillar epithelial cell lines (UT-SCC-60A and UT-SCC-60B) were susceptible to EV-A71, suggesting that human tonsillar crypt epithelium could be important in EV-A71 pathogenesis. However, the mechanism about how EV-A71 infects the upper oro-digestive tract remains largely unclear. In this study, we demonstrated that the human tonsillar epithelial cells infected with EV-A71 underwent apoptotic, in which cytochrome c was released from the mitochondria to the cytosol and caspase-9 was activated, while caspase-2 and -8 were not cleaved or activated during the infection. A selective inhibitor of caspase-9, Z-LEHD-FMK, inhibited the cleavage of the executioner caspase-3 and -7, indicating that only mitochondria-mediated intrinsic apoptotic pathway was activated in EV-A71-infected tonsillar epithelial cells. No evidence of pyroptosis or necroptosis was involved in the cell death. EV-A71 infection induced interferon, pro-inflammatory cytokines and chemokines, including IFN-ß, IL-6, CCL5, and TNF-α in tonsillar epithelial cells, which may play a critical role in EV-A71-caused herpangina. Our data indicated that the induction of the cytokines was partially regulated by the mitogen-activated protein kinases (MAPKs) signaling pathway. The findings unveiled the host response to EV-A71 and its regulation mechanism, and will further our understanding the significance about the tonsillar crypt epithelium as the initial and primary portal in viral pathogenesis for EV-A71 infection.

Enterovirus A71 2B Inhibits Interferon-Activated JAK/STAT Signaling by Inducing Caspase-3-Dependent Karyopherin-α1 Degradation.

Enterovirus A71 (EV-A71) is a major pathogen that causes the hand, foot, and mouth disease, which could be fatal with neurological complications in children. The underlying mechanism for the severe pathogenicity remains obscure, but impaired or aberrant innate immunity is considered to play a key role in viral pathogenesis. We reported previously that EV-A71 suppressed type I interferon (IFN) responses by inducing degradation of karyopherin-α1 (KPNA1), a component of the p-STAT1/2 complex. In this report, we showed that 2B, a non-structural protein of EV-A71, was critical to the suppression of the IFN-α-induced type I response in infected cells. Among viral proteins, 2B was the only one that was involved in the degradation of KPNA1, which impeded the formation of the p-STAT1/2/KPNA1 complex and blocked the translocation of p-STAT1/2 into the nucleus upon IFN-α stimulation. Degradation of KPNA1 induced by 2B can be inhibited in the cells pre-treated with Z-DEVD-FMK, a caspase-3 inhibitor, or siRNA targeting caspase-3, indicating that 2B-induced degradation of KPNA1 was caspase-3 dependent. The mechanism by which 2B functioned in the dysregulation of the IFN signaling was analyzed and a putative hydrophilic domain (H1) in the N-terminus of 2B was characterized to be critical for the release of cytochrome c into the cytosol for the activation of pro-caspase-3. We generated an EV-A71 infectious clone (rD1), which was deficient of the H1 domain. In rD1-infected cells, degradation of KPNA1 was relieved and the infected cells were more sensitive to IFN-α, leading to decreased viral replication, in comparison to the cells infected with the virus carrying a full length 2B. Our findings demonstrate that EV-A71 2B protein plays an important role in dysregulating JAK-STAT signaling through its involvement in promoting caspase-3 dependent degradation of KPNA1, which represents a novel strategy employed by EV-A71 to evade host antiviral innate immunity.

Novel human bocavirus in children with acute respiratory tract infection.

Human bocavirus (HBoV) and HBoV2, two human bocavirus species, were found in 18 and 10 of 235 nasopharyngeal aspirates, respectively, from children hospitalized with acute respiratory tract infection. Our results suggest that, like HBoV, HBoV2 is distributed worldwide and may be associated with respiratory and enteric diseases.

Human respiratory syncytial virus in children with acute respiratory tract infections in China.

There are limited data on the prevalence and clinical and molecular characterization of human respiratory syncytial virus (HRSV) in children with acute respiratory tract infections (ARTIs) in China. From December 2006 to March 2009, 894 nasopharyngeal aspirates (NPAs) were collected from children under 14 years of age with ARTIs. Samples were screened for HRSV and genotyped by reverse transcription-PCR (RT-PCR) and sequencing. Demographic and clinical information was recorded. A total of 38.14% (341/894) of samples were positive for HRSV. Phylogenetic analysis revealed that 60.4% of the selected 227 RSV strains were GA2, 34.4% were BA, 4.8% were GB2, and 0.4% were GB3. A total of 40.47% of all of the RSV-positive samples were coinfected with other respiratory viruses, and adenovirus was the most common additional respiratory virus. No statistical differences were found in the frequency of diagnosis and symptoms between the coinfection group and monoinfection group. Additionally, no statistical differences were found in epidemiological characterizations or disease severity between genotype BA- and GA2-positive patients, except for a greater frequency of lower respiratory tract infections (LRTIs) (mostly bronchitis)with BA. HRSV is the most important viral pathogen in Chinese children with ARTIs. Four genotypes (i.e., GA2, BA, GB2, and GB3) circulate locally, and the predominant genotype may shift between seasons. Coinfection with other viruses does not affect disease severity. HRSV genotypes were not associated with different epidemiological characterizations or disease severity.

[The detection and clinical feature of HcoV-nL63 in children with acute respiratory tract infection in Lanzhou city].

OBJECTIVE: To investigate the prevalence and clinical characterization of HCoV-NL63 (NL63) in children with acute respiratory tract infections (ARTIs) in Lanzhou with other respiratory viruses. The prevalence of HBoV1 in ALRTI was obviously city,China. METHOD: From November 2006 to October 2009,1169 nasopharyngeal aspirates (NPA) were collected from children under 14 years old with ARTIs. Samples were screened for NL63 using a reverse transcription-polymerase chain reaction (RT-PCR) and sequencing. Demography and clinical information were recorded. RESULT: NL63 was detected in 35 (2.99%) of the 1169 children. The peak of the positive rate were in August, September 2007, July, August 2008 (23.53%,17.65%, 50%, 33.33% separately). There are no NL63 positive samples was detected in December, 2007 to February 2009. 25 (25/35, 71.43%) were co-infected with other respiratory viruses, and human rhinovirus (HRV) were the most common additional respiratory virus. No significant differences of infective rate of NL63 was found between < or = 3 years age group and > 3 years age group. Bronchiolitis and pneumonia were the most frequent diagnoses in NL63 positive patients and the major symptoms were fever and cough in our study. Between the monoinfection group and the coinfection group of NL63-positive patients, no differences were found in symptoms and clinical diagnoses except symptoms of gastrointestinal. CONCLUSION: HCoV-NL63 is an important pathogen of acute respiratory tract infection in children in Lanzhou city. The peak of HCoV-NL63 infections was in summer. There were annual differences in the prevalence of HCoV-NL63. HCoV-NL63 infections existed a high rate of mixed infection, and mixed infection does not increase the severity of the disease.

[The research of saffold virus in children with lower respiratory tract infection in Changsha].

OBJECTIVE: To investigate prevalence of Saffold virus (SAFV) in Changsha area of hospitalized children with respiratory tract infection, and to discuss whether this virus is related to respiratory tract infection of children. METHODS: 643 nasopharyngeal aspirates samples were collected from hospitalized children with respiratory tract infection of the first affiliated hospital of Hunan nomal university during Nov. 2007 to Oct. 2008. Real-time fluorescent quanti-tative PCR(FQ-PCR) performed to screen the 5'UTR gene. And then analyze clinical data. RESULTS: SAFV were detected in 67 patients (10.42%) out of the 643 children, it was not detected over 5 years of age. The virus were detected in 8 patients (25.81%) out of the 31 children with persistent pneumonia and chronic pneumonia, there was statistically significant. CONCLUSION: There existed SAFV infection in hospitalized children with lower respiratory infection in Changsha area; SAFV maybe related to disease onset with lower respiratory tract infection of children.

[Molecular epidemiological and clinical features of coronavirus HKU1 in children with acute respiratory tract infection in Lanzhou].

OBJECTIVE: Human coronavirus (CoV)-HKU1 (HCoV-HKU1) was first isolated by Woo et al in Hong Kong. Several successive reports confirmed retrospectively that this new human coronavirus was circulating in different countries worldwide. However, the impact and the role of the emerging HCoV-HKU1 were not defined in children with ARTI. The objective of this study was to investigate the molecular epidemiology and clinical characteristics of HCoV-HKU1 infection in children with ARTI in Lanzhou, China. METHOD: Nasopharyngeal aspiration (NPA) samples were collected from 301 children with ARTI at the First Hospital of Lanzhou University, Gansu Province, China, between November 2007 and October 2008. Demographic data and clinical findings of these children were collected at the same time. The informed consent was obtained from their parents. This study protocol was approved by the hospital ethics committee. The reverse transcription polymerase chain reaction (RT-PCR) was employed to screen HCoV-HKU1. Furthermore, other common respiratory viruses were screened in HCoV-HKU1 positive samples. All PCR positive products were sequenced, and phylogenetic analysis was conducted. RESULT: The overall frequency of HCoV-HKU1 infection was 5.0% (15/301). The HCoV-HKU1 pol gene sequences shared a 95.8% - 99.6% nucleotide identity with the human coronavirus-HKU1 strain, whereas the amino acid identity was 90.7% - 99.3%. The phylogenetic analysis revealed that the HCoV-HKU1 strain pol gene clustered with the HCoV-HKU1 strain N15 genotype B (no. DQ415911); 11 of 15 HCoV-HKU1 positive sample tested were mixed-infection. HCoV-HKU1 was detected only from November to April. Positive specimens peaked in November. Children with HCoV-HKU1 infection varied in age from 15 day to 12-years (median age, 10 months). The clinical diagnoses of HCoV-HKU1 positive patients included those with AURI and LURI. The clinical presentations of HCoV-HKU1 positive children included fever, cough, sputum production, diarrhea, vomiting; pharynx engorgement, crackles, and wheezing. The mean hospital stay of the 14 patients was 9.9 days. Six of 15 HCoV-HKU1 positive patients had an underlying illness, and they were all inpatients (hospital stay, mean, 11.2 days). There was no statistically significant difference in the detection rate between the two groups with and without underlying illnesses. CONCLUSION: Human CoV-HKU1 infection exists in children with respiratory tract infections in Lanzhou region. A single HCoV-HKU1 genotype B was circulating locally. The symptoms and clinical diagnoses of those infected with HCoV-HKU1 had no specificity as compared with patients with other common respiratory viruses infection.

Prevalence and clinical characteristics of human CoV-HKU1 in children with acute respiratory tract infections in China.

BACKGROUND: Human CoV-HKU1 (HCoV-HKU1) has been isolated from a 71-year-old man with pneumonia; however, the impact and role of emerging HCoV-HKU1 have not been defined in children with acute respiratory tract infection (ARTI). OBJECTIVE: To investigate the Prevalence and clinical characteristics of HCoV-HKU1 in children with ARTI in Lanzhou, China. STUDY DESIGN: The reverse transcription polymerase chain reaction (RT-PCR) or PCR was employed to screen HCoV-HKU1 and other common respiratory viruses in 645 nasopharyngeal aspirate (NPA) specimens collected from children with ARTI from November 2006 to October 2008. All PCR positive products were sequenced. And the demographic and clinical data were collected for all patients. RESULTS: Nineteen of 645 (2.95%) specimens tested positive for HCoV-HKU1, and all HCoV-HKU1 positive specimens were distributed in the winter and spring season. The HCoV-HKU1 co-infection rate with other respiratory viruses was 47.37% (9/19). There was no statistically significant difference in the detection rate between groups by age or gender, except between patients with and without underlying diseases. The phylogenetic analysis indicated that HCoV-HKU1 genotype B was circulating in the years 2007 and 2008 in children with ARTI in Lanzhou, China. CONCLUSIONS: HCoV-HKU1 is an uncommon virus existing among Chinese children with ARTI. Children with underlying diseases are more vulnerable to viral infection. Only HCoV-HKU1 genotype B circulated locally.