ABSTRACT
Objective To study the characteristics of auditory brainstem response by chirp and click stimuli in normal hearing children.Methods A total of 97 children (194 ears)with normal hearing were recruited,including 50 male (100 ears),and 47 female (94 ears).The CE-chirp and the click acoustic stimulation were used to,and the ABR waveforms and latencies were obtained.ResuIts The chirp-ABR Ⅰ wave recognition rate (36%)was significantly lower than that of click-ABR (100%).At 80 dB nHL,chirp-ABR V wave latency was shorter than click-ABR,the difference was statistically significant (P0.05).At 80 dB nHL,no statistical significance of two kinds of a-coustic stimulation of ABR V wave amplitude difference (P>0.05).At 50 dB nHL,chirp-ABR significantly in-creased than click-ABR V wave amplitude with statistically significant differences (P0.05 ).ConcIusion The chirp acoustic stimulation produced the larger response amplitude,and was faster,demonstrating the noticeable advantages to tes-ting children.
ABSTRACT
In vitro cellular adherence of murine neutrophils (Neu), macrophages (Mo) and eosinophils (Eos) to infective larvae (L3) of periodic Brugia malayi was promoted by immune serum (AIMS) or fresh normal mice serun (fNMS). Mo and Neu were more potent than Eos . in killing the L3. Eos could adhere to the L3 in the presence of AIMS or fNMS but a weak cy-totoxic effect was observed only when AIMS was used. The activity in AIMS could be removed with Staphylococcus aureus containing Protein-A (SPA) or anti-mice IgG antiserum suggesting that IgG might be in the observed cytotoxicity. Immunofluorescent staining revealed IgG binding to the surface of L3 after incubation with AIMS. Heat treatment of AIMS at 56℃ 30 min resulted in a reduced cytotoxic effect suggesting the role of complement in the reaction. EDTA but not EGTA abolished this activity indicating the operation of complement by alternate pathway. Scanning electron microscopic (SEM) studies comfirmed that the celluar adherence resulted in gross surface damage to the infective larvae.