Participation of the inositol 1,4,5-trisphosphate-gated calcium channel in the zona pellucida- and progesterone-induced acrosome reaction and calcium influx in human spermatozoa.

The acrosome reaction is a prerequisite for fertilization, and its signaling pathway has been investigated for decades. Regardless of the type of inducers present, the acrosome reaction is ultimately mediated by the elevation of cytosolic calcium. Inositol 1,4,5-trisphosphate-gated calcium channels are important components of the acrosome reaction signaling pathway and have been confirmed by several researchers. In this study, we used a novel permeabilization tool BioPORTER® and first demonstrated its effectiveness in spermatozoa. The inositol 1,4,5-trisphosphate type-1 receptor antibody was introduced into spermatozoa by BioPORTER® and significantly reduced the calcium influx and acrosome reaction induced by progesterone, solubilized zona pellucida, and the calcium ionophore A23187. This finding indicates that the inositol 1,4,5-trisphosphate type-1 receptor antibody is a valid inositol 1,4,5-trisphosphate receptor inhibitor and provides evidence of inositol 1,4,5-trisphosphate-gated calcium channel involvement in the acrosome reaction in human spermatozoa. Moreover, we demonstrated that the transfer of 1,4,5-trisphosphate into spermatozoa induced acrosome reactions, which provides more reliable evidence for this process. In addition, by treating the spermatozoa with inositol 1,4,5-trisphosphate/BioPORTER® in the presence or absence of calcium in the culture medium, we showed that the opening of inositol 1,4,5-trisphosphate-gated calcium channels led to extracellular calcium influx. This particular extracellular calcium influx may be the major process of the final step of the acrosome reaction signaling pathway.

[Effect of Ca2+ on the Nitrification Activity and the Flocculation and Sedimentation Performances of the Activated Sludge].

Ca2+ is an important microbial growth factor that can affect the activity, flocculation, and sedimentation of activated sludge. In order to study the roles of Ca2+ in the activated sludge system, the activity changes of ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) were analyzed using the specific oxygen uptake rates (SOURAOB and SOURNOB). The changes in composition and structure of extracellular polymeric substances (EPS) were analyzed using Fourier transform infrared spectroscopy (FTIR) and three-dimensional excitation emission fluorescence spectroscopy (3D-EEM). The effects of Ca2+on the nitrification activity and microbial metabolites were investigated. The results showed that when the Ca2+concentration increased from 0.45 mmol·L-1 to 3 mmol·L-1, SOURAOB and SOURNOB increased from 6.3 mg·(g·h)-1 to 10.4 mg·(g·h)-1 and from 2.3 mg·(g·h)-1 to 3.7 mg·(g·h)-1, respectively. The EPS concentrations increased from 68 mg·g-1 to 93 mg·g-1, and the flocculation ability (FA) of the sludge was improved. When the Ca2+ concentration was higher than 3 mmol·L-1, SOURAOB and SOURNOBboth decreased. The FA was maintained at about 30%, and the particle size of the sludge continued to increase. Based on FTIR analysis, the main components of EPS were always amino, amide Ⅰ, and carboxyl with an increase in Ca2+ concentration. Based on EEM analysis, the composition of loosely-bound (LB)-EPS did not change, and humic acid substances appeared in the tightly-bound (TB)-EPS at low nitrification rates. Low concentrations of Ca2+ promoted nitrification activity and flocculation of the sludge. However, high concentrations of Ca2+ led to a decline in the sludge nitrification activity.

[Effect of NaCl Salinity on Extracellular Polymeric Substances and Bioflocculation of Anoxic Sludge in A2/O Process].

In order to improve the biological removal efficiency of nitrogen and phosphorus and bioflocculation performance of salt-containing wastewater, the effect of NaCl salinity on the efficiency of denitrification and phosphorus removal in the anoxic zone of an A2/O process was investigated. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to analyze the composition and structure of extracellular polymeric substances (EPS) in activated sludge of the anoxic zone, to discern the effect of salinity on bioflocculation. Results showed that when NaCl salinity was 0-5 g·L-1, flocculation ability (FA) in A2/O anoxic zone was about 44% and the sludge particle size was 45.5 µm. EPS content increased from 52.3 mg·L-1 to 62 mg·L-1 and protein (PN)/polysaccharide (PS) remained at 2.1. When NaCl salinity increased from 10 g·L-1 to 40 g·L-1, bioflocculation of sludge significantly decreased. FA decreased from 40% to 22% and sludge particle size decreased from 43.7 µm to 32.1 µm. EPS content increased from 76.5 mg·L-1 to 101.0 mg·L-1 and PN/PS decreased from 1.5 to 1.3. Based on FTIR analysis, with increase in salinity, the main components of EPS were always amino, amideⅠ, and carboxyl. Based on XPS analysis, increasing salinity led to charge transfer of some groups (such as C, O, and N groups) during the interaction between EPS and Na+, but its form did not change.

[Detection of respiratory syncytial virus in children with respiratory tract infections by nucleic acid amplification fluorogenic quantitative assay].

OBJECTIVE: Nucleic acid amplification (PCR) fluorogenic quantitative assay is used for the diagnosis of respiratory syncytial virus (RSV) infection. This study was designed to explore the sensitivity of PCR fluorogenic quantitative assay for ascertaining respiratory RSV infection and RSV infection conditions by detecting the presence of RSV-RNA related sequences in children. METHODS: Bronchial and nasopharyngeal secretions specimens from 261 hospitalized children with respiratory tract infections from January 2007 to October 2008 were collected. Respiratory syncytial virus nucleic acid (RNA) in the specimens was measuredby PCR fluorogenic quantitative assay. Blood RSV-IgM was detected by enzyme linked immunosorbent assay (ELISA). The sensitivity for ascertaining respiratory RSV infection was compared between the two assays. RESULTS: The RSV-RNA positive rate ascertained by PCR fluorogenic quantitative assay (38.7%) was significantly higher than blood RSV-IgM positive rate (21.1%) (p<0.01). The RSV-RNA positive rate (43.6%) in children at ages of less than 6 months was significantly higher than that in children at ages of 1 to three years (32.1%) (p<0.01). The RSV-RNA positive rate in children with bronchiolitis (58.5%) was the highest, followed by bronchopneumonia (38.2%) and acute bronchitis (20.0%). CONCLUSIONS: The sensitivity of PCR fluorogenic quantitative assay for ascertaining respiratory RSV infection is higher. RSV is a major pathogen of lower respiratory tract infections in infants and young children. A higher rate of RSV infection is associated with a younger age. RSV infection is the most common in children with bronchiolitis.