The Seroprevalence of Some Pathogen Specific IgM in Children with Acute Respiratory Tract Infections in Guangzhou Region, 2011 - 2012.

BACKGROUND: Acute respiratory tract infections (ARTIs) are the leading cause of morbidity and death in children < 5 years worldwide. The aim of this study is to analyze the seroprevalence of nine pathogen specific IgMs in children with ARTIs with respect to gender, age, and seasonality in the Guangzhou region. METHODS: Serum samples were collected from 20160 children with ARTIs admitted to the Guangzhou Women and Children's Medical Center between 2011 and 2012. Serum-specific IgM antibodies to nine respiratory pathogens, Mycoplasma pneumonia (MP), Legionella pneumophila (LP), Coxiella burnetii (C. burnetii), Chlamydophila pneumonia (CP), adenovirus (ADV), respiratory syncytial virus (RSV), type A and type B influenza virus (IVA and IVB), and parainfluenza virus (PIV), were detected using immunofluorescence assay. RESULTS: The male-to-female ratio of all patients was 1.9:1. The median age was 3 years and 8 months with a significant difference in seropositivity to respiratory tract pathogens between children from different age groups. Seropositivity was detected in 43.53% of the children with the top three pathogens being MP (33.15%), RSV (10.27%), and ADV (6.63%), followed by IVB (2.63%), LP (2.25%), IVA (1.59%), PIV (1.57%), CP (0.27%), and C. burnetii (0.13%). The prevalence of single, double, and triple seropositivity was 70.20% (6160/8775), 25.22% (2213/8775), and 4.57% (401/8775), respectively. The total IgM seropositivity for any kind of pathogen in the nine kinds of pathogens peaked in winter (46.53%), while the nadir was observed in summer (41.97%). CONCLUSIONS: The top three seroprevalence of nine kinds of pathogen specific IgM was MP, followed by RSV and ADV. The epidemic pathogen specific IgM had a season-specific seropositivity distribution. Seroprevalence of the pathogen should be a focus of attention.

The Serum Value of NO and IL-17 were Increased in Children with Influenza A Viral Pneumonia.

BACKGROUND: Influenza A virus can cause severe respiratory infection in children and even result in immune system dysfunction. The aim of this study is to examine the clinical value of peripheral blood lymphocytes and serum nitric oxide (NO) and cytokines in children with influenza A viral pneumonia. METHODS: Thirty children hospitalized with confirmed influenza A viral pneumonia and 30 healthy controls were enrolled in this study. The blood samples were collected from all the children and anti-coagulated with EDTA. The peripheral blood lymphocyte subsets were analyzed by flow cytometry. Griess assay were performed to calculate serum NO and nitrite (NO2-) levels. The serum concentrations of IFN-γ and IL-17 were measured by ELISA. RESULTS: The serum levels of NO, NO2-, and IL-17 were significantly higher in children with influenza A viral pneumonia than controls (p < 0.01), while the level of IFN-γ had no significant difference (p = 0.515). Additionally, the patients had significantly lower percentages of peripheral blood CD3+, CD3+CD4+ T lymphocytes, and CD56+CD16+ natural killer (NK) cells than controls (p < 0.05), while CD3+CD8+ and CD4-CD8- (double negative, DN) T lymphocytes did not differ significantly (p > 0.05). Correlation analysis suggests that the serum NO level is positively correlated with IL-17 (p < 0.05). Conclusions: The increased levels of NO and IL-17 may be related to dysregulated lymphocytes' immune response in children with influenza A viral pneumonia. These abnormalities may be the main cause of inflammatory lung damage, and thus have significant prognostic value.

Human adenovirus (HAdV) infection in children with acute respiratory tract infections in Guangzhou, China, 2010-2021: a molecular epidemiology study.

BACKGROUND: Human adenovirus (HAdV) infection can cause a variety of diseases. It is a major pathogen of pediatric acute respiratory tract infections (ARIs) and can be life-threatening in younger children. We described the epidemiology and subtypes shifting of HAdV among children with ARI in Guangzhou, China. METHODS: We conducted a retrospective study of 161,079 children diagnosed with acute respiratory illness at the Guangzhou Women and Children's Medical Center between 2010 and 2021. HAdV specimens were detected by real-time PCR and the hexon gene was used for phylogenetic analysis. RESULTS: Before the COVID-19 outbreak in Guangzhou, the annual frequency of adenovirus infection detected during this period ranged from 3.92% to 13.58%, with an epidemic peak every four to five years. HAdV demonstrated a clear seasonal distribution, with the lowest positivity in March and peaking during summer (July or August) every year. A significant increase in HAdV cases was recorded for 2018 and 2019, which coincided with a shift in the dominant HAdV subtype from HAdV-3 to HAdV-7. The latter was associated with a more severe disease compared to HAdV-3. The average mortality proportion for children infected with HAdV from 2016 to 2019 was 0.38% but increased to 20% in severe cases. After COVID-19 emerged, HAdV cases dropped to 2.68%, suggesting that non-pharmaceutical interventions probably reduced the transmission of HAdV in the community. CONCLUSION: Our study provides the foundation for the understanding of the epidemiology of HAdV and its associated risks in children in Southern China.

Characterization of lymphocyte subsets in peripheral blood cells of children with EV71 infection.

BACKGROUND: Enterovirus 71 (EV71) is one of the major causative pathogens of hand, foot, and mouth disease (HFMD). Immune cells play a critical role in determining the outcomes of virus infection. We aimed to characterize the lymphocyte subsets and transcriptional levels of T lymphocytes-associated transcription factors in peripheral blood cells of children with EV71 infection. METHODS: Peripheral blood samples from 32 children with EV71 infection and 32 control subjects were included in this study. The frequencies of T-, B-lymphocytes, and their subsets were determined by flow cytometry. The expression of transcription factors, including T-bet, Gata3, ROR γ t, Foxp3, TCF-1, and BCL-6 in the whole blood cells were evaluated by real-time reverse-transcription quantitative polymerase chain reaction (RT-qPCR). RESULTS: The frequencies of T cells, helper T cells (Th), cytotoxic T cells (Tc), IFN-γ+ Th1, IFN-γ+ Tc1, and regulatory T (Treg) cells were significantly decreased (P < 0.01) in children with EV71 infection. As for IL-4+ Th2, IL-4+ Tc2, IL-17+ Th17, IL-17+ Tc17, follicular helper T cells (Tfh), CD3+CD8+IL-21+ T cells, CD19+ B cells, and CD19+IL-10+ B10 cells, their frequencies were significantly increased in the EV71 group (P < 0.01). The EV71 group had lower mRNA expressions of T-bet, Gata3, and Foxp3 than the control group (P < 0.05), whereas the expressions of ROR γ t, TCF-1, and BCL-6 showed no significant difference between two groups. CONCLUSIONS: EV71 infection in children caused a decreased frequency of total Th, Tc and Treg cells, and increased percentages of B cell, Th2 and Th17 cells in blood.

[Protective effects of sini decoction on adriamycin-induced heart failure and its mechanism].

OBJECTIVE: To investigate the protective effects of Sini decoction (SND) on Adriamycin-induced heart failure and its mechanism. METHODS: SD rats were randomly divided into three groups:control group,heart failure model group and SND group. ADR was injected in to the rats of model group and SND group by caudal vein. After injection,the rats in SND group were given SND [3.75 g/(kg x d), p.o.]. Three weeks later, protein expressions of Bid and Bcl-xl were detected by immunohistochemistry; mRNA expression ratio of Bcl-xl/Bcl-xs was detected by RT-PCR and apoptosis rate was determinated by flow cytometry. RESULTS: Compared with control group, the protein expression of Bcl-xl and mRNA ratio of Bcl-xl/Bcl-xs obviously decreased,while the protein expression of Bid and apoptosis rate significantly increased in the model group. SND could decrease cell apoptosis, increase the protein expression of Bcl-xl, increase bcl-xl/bcl-xs mRNA ratio and decrease Bid protein expression. CONCLUSION: Bcl-xl may play an important role in ADR-induced heart failure rats. The mechanism of SND on protecting cardiocyte may be related to apoptosis correlation factor, Bcl-xl and Bid.

Magainin-modified polydopamine nanoparticles for photothermal killing of bacteria at low temperature.

Photothermal therapy (PTT) is a promising method to kill bacteria because of the broad-spectrum of antibacterial activity and the ability of spatiotemporal regulation. In the previously reported systems, light induced high temperature (˜70 °C) was essential for effectively killing of bacteria, which, however, would also damage nearby nontarget cells or tissues. Here we report photothermal nanoparticles (NPs) for more targeting and killing bacteria at a relative low temperature. Polydopamine (PDA) was chosen to prepare NPs because of its excellent capability of photothermal conversion. Magainin I (MagI) which is an antimicrobial peptide was used to modify NPs' surface because it can specifically interact with bacteria. We demonstrate that MagI-PEG@PDA NPs effectively killed E. coli at a low temperature of ˜45 °C upon near-infrared (NIR) light irradiation. In contrast, the native PDA NPs under light irradiation or the MagI-PEG@PDA NPs themselves showed no bacteria killing ability. This work highlights the importance of close interaction between the target bacteria and the photothermal materials and may promote the practical clinical applications of the PTT.

Protective effect of tetramethylpyrazine and salvianolic acid B on apoptosis of rat cerebral microvascular endothelial cell under high shear stress.

Apoptosis induced by high shear stress has been reported for the dysfunction of various vascular endothelial cells. We investigated the protective effects of tetramethylpyrazine (TMP) and salvianolic acid B (SAB) from Chinese medicine on the shear-induced early and late stages of apoptosis in cultured rat cerebral microvascular endothelial cells (rCMECs) under pathological high shear stress. Near-confluent cultures of rCMECs were pretreated with TMP or SAB and their combinational dosages, and exposed to high shear stress generated by a rheometer. Apoptotic death rate of rCMECs was assessed by immunofluorescence microscopy of Annexin V-FITC and propidium iodide (PI). We found that early and late stage apoptosis occurred at 3.0 Pa for a short duration of 450 sec but did not occur at 1.5 Pa. SAB inhibited the cells from apoptosis at concentrations from 10 microM to 20 microM in a dose-dependent manner, while effect of TMP at 0.37 mM and 0.73 mM did not significantly differ. Moreover, the combined use of TMP and SAB had synergistic anti-apoptotic effects (P<0.01). The results indicate that the anti-apoptotic effect of TMP and SAB on rheologically induced endothelial injury is likely involved in their efficacy.

[Study on activity and mechanism of Sini Decoction anti-mitochondrial oxidation injury caused by myocardial ischemia/reperfusion].

OBJECTIVE: To study the activity and mechanism of Sini Decoction (SND) Anti-mitochondrial Oxidation Injury caused by Myocardial Ischemia/Reperfusion. METHODS: Kun ming mice were randomly divided into three groups: Control group, Ischemia/Reperfusion (I/R) group and SND-treated group. At the end of experiment,hearts of mice were taken out for further detection. Activity of myocardium and mitochondrial SOD, content of myocardium and mitochondrial MDA, swelling of mitochondria, Lactic Acid content of myocardium and MnSODmRNA expression were observed. RESULTS: SND could increase the activity of myocardium and mitochondrial SOD (P<0.01), decrease the content of myocardium and mitochondrial MDA (P<0.01), decrease the Lactic Acid content of myocardium, lighted the swelling of mitochondria (P<0.01) and change the expression of MnSODmRNA (P<0.01). CONCLUSION: Sini decoction can anti-mitochondrial oxidation injury caused by Myocardial Ischemia/Reperfusion, its mechanism may be relate to increasing the MnSODmRNA expression.

The effect of ginkgo biloba extract (EGb 761) pretreatment on intestinal epithelial apoptosis induced by intestinal ischemia/reperfusion in rats: role of ceramide.

Apoptosis was demonstrated to be a major mode of intestinal epithelial cell death caused by intestinal ischemia/reperfusion (II/R). Ceramide has been proposed as a messenger for apoptosis. The present study was aimed to investigate the effect of Ginkgo biloba extract 761 (EGb 761) pretreatment on II/R-induced intestinal mucosal epithelial apoptosis in rats and the mechanism related to ceramide. The rat model of II/R injury was produced by clamping superior mesenteric artery for 60 min followed by reperfusion for 180 min. Twenty four rats were randomly allocated into Sham, II/R and EGb + II/R groups. In EGb + II/R group, EGb 761 (100 mg/kg per day) was administered intragastrically for 7 days before the surgery. Animals in II/R and sham groups were treated with equal volume of normal saline solution. Intestinal mucosal epithelial apoptosis was detected via electron microscopy and TUNEL method. Lipid peroxidation in intestinal mucosa was determined by detecting the malondialdehyde level and the activities of superoxide dismutase and peroxidase glutathione. The ceramide generation and sphingomyelinase (SMase) mRNA expression in intestinal mucosa were determined by high performance, thin layer chromatography, and RT-PCR, respectively. II/R caused intestinal mucosal epithelial apoptosis and over-production of the ceramide accompanied by up-regulation of SMase mRNA expression and increases of lipid peroxidation. EGb 761 pretreatment significantly decreased apoptosis index, and concurrently reduced the ceramide generation accompanied by down-regulation of SMase expression and inhibition of lipid peroxidation. The findings indicate that EGb 761 pretreatment attenuates II/R-induced intestinal epithelial apoptosis, which might be attributable to its antioxidant action of mediating ceramide pathway.

[Protective effects of Sini decoction on adriamycin-induced heart failure and its mechanism: role of superoxide dismutase].

OBJECTIVE: To investigate the role of superoxide dismutase (SOD) in Adriamycin (ADR)-induced heart failure and the protective effects of Sini decoction (SND). METHOD: SD rats were randomly divided into three groups, control group, heart failure group and SND group. ADR was injected in the rats of heart failure group and SND group by caudal vein. After injection, the rats in SND group were given SND (3.75 g x kg(-1) x d(-1), p.o.). Three weeks later, cardiac function, content of malondialdehyde (MDA) of both myocardium and mitochondria and activity of Cu-Zn SOD and Mn SOD were measured. The mRNA expression of Cu-Zn SOD and Mn SOD were also detected by RT-PCR. RESULT: Compared with control group, LVSP and +/- dp/dt max were obviously decreased, while LVEDP was markedly increased in the heart failure group. The mRNA expression and the activity of Cu-Zn SOD and Mn SOD in heart failure group were obviously lower than that in the controls'. In addition, the MDA content of both myocardium and mitochondria were clearly increased in heart failure rats. In SND-treated rats, the cardiac function, the activity and the mRNA expression of Cu-Zn SOD and Mn SOD were significantly elevated and the content of MDA was reduced, which had no statistic difference with the rats in control group. CONCLUSION: The data suggest that oxidative stress is present in the mitochondria of myocardium in ADR-induced heart failure rats and it can be eased by SND. The mechanism may be closely related to SOD.

Berberine acutely inhibits the digestion of maltose in the intestine.

ETHNOPHARMACOLOGICAL RELEVANCE: The Chinese Goldthread Rhizome has been used in the Traditional Chinese Medicine as an important ingredient of many formulas for the treatment of diabetes mellitus. Berberine, the main effective composition of Chinese Goldthread Rhizome, is also effective in treating diabetes in today's clinical practice of Traditional Chinese Medicine. AIM OF THE STUDY: To evaluate the hypoglycemic activity of berberine which treats acutely on the postprandial blood glucose, and to explore the mechanism of this activity. MATERIALS AND METHODS: 1. One-dose preprandial intragastric administrations of berberine were given to normal animals (dogs and rats), and the postprandial blood glucose concentration curves were measured. Serum insulin enzyme linked immunosorbent assay (ELISA) was only performed in rats. 2. The euglycemic clamp test was performed to evaluate the effect of one-dose berberine intragastric administration on the blood glucose transformation and utilization rate in rats. 3. In the Caco-2 cell monolayer test, the changes of glucose concentration on the apical and basolateral sides were measured when the maltose solution containing berberine was added to the apical side. 4. The inhibition ratio of berberine against α-glucosidase was measured in vitro. 5. The effect of berberine on the fluorescence emission spectrums of α-glucosidase was studied. RESULTS: One-dose preprandial intragastric administration of berberine delayed the rise of post-maltose blood glucose, did not affect postprandial blood glucose after glucose meal, and did not affect the insulin level in normal rats; reduced post-maltose blood glucose in normal dogs. 2. The result of euglycemic clamp test showed that one-dose intragastric administration of berberine had no effect on the blood glucose transformation and utilization rate in rats. 3. Berberine added to the maltose solution on the apical side of Caco-2 cell monolayer reduced the glucose concentration on the apical side. Glucose in basolateral side of all groups cannot be detected. 4. Berberine inhibited the activity of α-glucosidase in vitro. 5. Berberine significantly and concentration dependently quenched the fluorescence emission spectrum of α-glucosidase. CONCLUSION: Our findings suggest an additional mechanism of the hypoglycemic activity of berberine by demonstrating its ability to acutely inhibit the α-glucosidase, and support the traditional use of berberine and Chinese Goldthread Rhizome for the treatment of diabetes mellitus.

[Application of fluorescent real-time polymerase chain reaction in analyzing the epidemic of influenza among children in Guangzhou area in 2006].

OBJECTIVE: To investigate the prevalence of influenza virus infections in children in 2006 using the real-time PCR method. METHODS: (1) Consulting the most conserved sequence NP gene of influenza virus, after comparing with the NP gene sequences of influenza virus in GenBank, one pair of specific primers and one TaqMan probe were designed for each subtype of influenza virus by the software Primer Express. The sensitivity of influenza was evaluated by testing known positive samples which had been two-fold diluted. The specificity of real-time PCR for influenza virus detection was assessed by cross testing 60 isolates of influenza A, 16 isolates of influenza B, and by testing a variety of other respiratory viruses positive samples; (2) 281 nasopharyngeal aspirate samples were detected by real-time PCR and virus isolation; (3) the 12 301 specimens from the patients of Guangzhou Children's Hospital were tested by using the real-time PCR method. Furthermore, the real-time PCR reagent was evaluated by comparing with the result of virus isolation. RESULTS: (1) The sensitivity of real-time PCR developed in this study for influenza A detection was 1:2(22) and for influenza B was 1:2(20) in two-fold serially diluted way. (2) No positive results were found in cross testing of other viruses positive specimens. (3) Influenza virus was detected from 1687 cases (13.71%) out of the 12 301 cases, including 773 cases (45.8%) positive for subtype A and 914 cases (54.2%) positive for subtype B; 455 out of 525 (86.7%) of influenza B positive specimens and 70 out of 525 (13.3%) of influenza A (H1N1) positive specimens were from patients seen during January to April; 419 out of 1118 (37.5%) specimens positive for influenza B and 699 out of 1118 (62.5%) specimens positive for influenza A (H1N1) were from patients seen from May to August. Influenza virus could be identified from 1380 samples by the methods of virus isolation, accounting for 81.80% of the 1687 positive samples detected by real-time PCR. All the influenza virus subtype A was H1N1. CONCLUSION: The real-time PCR method developed in this study was sensitive and specific for detecting influenza A and B in clinical specimens. During 2006, influenza A and influenza B co-circulated. The predominant virus was influenza B from January to April, peaking in April. Influenza A (H1N1) prevailed from May to August, with the peak in June.

Integrating polymerase chain reaction, valving, and electrophoresis in a plastic device for bacterial detection.

An integrated plastic microfluidic device was designed and fabricated for bacterial detection and identification. The device, made from poly(cyclic olefin) with integrated graphite ink electrodes and photopatterned gel domains, accomplishes DNA amplification, microfluidic valving, sample injection, on-column labeling, and separation. Polymerase chain reaction (PCR) is conducted in a channel reactor containing a volume as small as 29 nL; thermal cycling utilizes screen-printed graphite ink resistors. In situ gel polymerization was employed to form local microfluidic valves that minimize convective flow of the PCR mixture into other regions. After PCR, amplicons (products) are electrokinetically injected through the gel valve, followed by on-chip electrophoretic separation. An intercalating dye is admixed to label the amplicons; they are detected using laser-induced fluorescence. Two model bacteria, Escherichia coli O157 and Salmonella typhimurium, were chosen to demonstrate bacterial detection and identification based on amplification of several of their unique DNA sequences. The limit of detection is about six copies of target DNA.