[Investigation of risk factors for hearing impairment in premature infants].

OBJECTIVE: To investigate the risk factors for hearing impairment in premature infants. METHODS: A total of 895 premature infants who were admitted to the neonatal intensive care unit from January to December 2010 were evaluated using distortion product otoacoustic emission to detect hearing impairment. The failure rates in initial screening and secondary screening were recorded. The risk factors for failure to pass hearing screenings were elucidate using multivariate logistic regression analysis. RESULTS: The failure rate in initial screening was 38.4%, and the failure rate in secondary screening was 18.3%. In the auditory brainstem response test conducted at three months after birth, the failure rate was 22.2%. In premature infants with a gestational age of 28-29(+6) weeks, 60.5% did not pass the initial screening; 48.1% of the premature infants with a birth weight of 1 001-1 499 g failed the initial screening; 70.0% of the premature infants with a birth weight of ≤1 000 g failed the initial screening; 53.8% of the premature infants who had severe asphyxia failed the initial screening; 45.0% of the premature infants who used invasive ventilation failed the initial screening; 47.9% of the premature infants with a total bilirubin of ≥340 µmol/L failed the initial screening; 54.6% of the premature infants with septicemia failed the initial screenings. The multivariate logistic regression analysis revealed the following independent risk factors for failing the initial and secondary hearing screenings: gestational age, birth weight, hyperbilirubinemia and septicemia. CONCLUSIONS: Premature infants are susceptible to hearing impairment because they have immature organs and tissues and incomplete blood-brain barrier function and are sensitive to such factors as hyperbilirubinemia and infection. Early hearing screening and follow-up are necessary for premature infants to ensure timely interventions.

[Cloning and expression of Tssk1 & Tssk2 in mice and the presence & localization of them in mature sperm].

We sought to experimentally verify if testis specific serine/threonine kinases (Tssks) play a role in spermatogenesis and/or the regulation of sperm function. Purified Tssk proteins were obtained based on cloning and expression of mouse Tssk1 and Tssk2. Tssk1 and Tssk2 were detected in mature mouse and human sperm by western blotting. Immunofluorescence indicated that Tssk1 is distributed in the acrosome and the entire flagellum of mouse sperm while Tssk2 was mainly distributed in post-acrosomal region. There was no alteration in the distribution pattern of Tssk1 and Tssk2 in non-capacitated and capacitated sperm. Tssk2 distribution remained unchanged after induced acrosome reaction but no signals were detected in the acrosome for Tssk1, which was present before the acrosome reaction, though signals in flagellum were undisturbed. In human sperm, Tssk1 was found in neck and flagellum while Tssk2 was found in the equatorial region. Our results suggest Tssk1 and/or Tssk2 do play an important role(s) in the regulation of sperm function.

[Structural characteristics of infrared spectra for polyaluminum chloride in enhanced reactions of modification].

As an important preparation method of Inorganic Polymer Flocculants (IPFs) with all-round performance, the use of enhanced reactions of modification for Polyaluminum Chlorides (PAC) is a trend of application. In this paper, auctorial-made multicore oligomers as a complexing agent, polysilicate as a crosslinking agent and polyacrylamide as a compounding agent are respectively used to enhance PAC and prepared three kinds of IPFs, named CO-PAC, CR-PAC and PAM-PAC. The Fourier Transform Infrared spectra (FTIR) of the three flocculants show that there have been found new chemical bonds beyond Al-OH in their structures, and each characteristic band of primary group in PAC has a band shift to a lower frequency due to its structural aberration. These evidences suggested that enhanced reactions of modification for PAC are not at all a simple process of physical mix, but a chemical reaction to form other structural characteristics of inorganic polymers. The excellent coagulation behavior of these new flocculants depends mainly on the chemical actions, but there are a little physical effects between the modifiers and PAC.