[The importance of intranasal trigeminal event-related potentials test for patients with olfactory dysfunction]

Objective: To analyze the characteristics of trigeminal event-related potentials (tERPs) in different kinds of olfactory disorders (OD), and to evaluate the importance of tERPs for the patients with olfactory dysfunction. Methods: Clinical data of 314 patients with olfactory dysfunction from the Smell and Taste Clinics in Beijing Anzhen Hospital from 2015 to 2021 were retrospectively reviewed, including 158 males and 156 females, aging from 6 to 78 years. The control group consisted of healthy people from medical examination center, who were gender and age matched. The clinical characteristics of OD were analyzed using Sniffin' Sticks test, olfactory event-related potentials (oERPs), tERPs and acoustic rhinometry test. SPSS 17.0 software was used to compare the difference of tERPs between the two groups, and to analyze the related factors affecting trigeminal function. Results: The ratio of tERPs presence was different in OD caused by different reasons: head traumatic OD (54.9%), post-virus infection OD (63.6%), sinonasal inflammatory OD (68.4%) and OD due to other causes (56.9%). Compared with controls, tERPs signals in OD patients showed a significant lower amplitude in the N₁ wave (all P<0.001), and lower amplitude in the P₂ wave in most OD patients (head trauma t=-4.11, P<0.001; sinonasal inflammation t=-2.04, P=0.046; others t=-2.40, P=0.020) except in OD by post-virus infection (t=-1.98, P=0.052). tERPs signals in OD patients by sinonasal inflammation showed longer latency in the N₁ wave (t=2.15, P=0.036), but this difference was not observed in other OD patients (all P>0.05). tERPs signals were significantly correlated with the Sniffin' Sticks score, deficiency of oERPs and nasal minimum cross-sectional area (all P<0.05). Conclusions: OD patients show neurophysiologic deficits in trigeminal function. The absence of tERPs or lower amplitude in N₁ waves are the important characteristics of patients with OD.

Study of the expression of GABA(A) receptor in rats during acute lung injury caused by endotoxin

The objective of the present study was to investigate the role of γ-aminobutyric acid type A receptor (GABA(A)R) in lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats. Thirty-two male wistar rats were randomly divided into four groups. Rats in the GABA group were pretreated with LPS and GABA, while those in the bicuculline (BIC) group were pretreated with LPS and bicuculline. We assessed the arterial blood gas, dry/wet ratio, and the level of tumor necrosis factor-α (TNF-α), IL-6, malondialdehyde, and superoxide dismutase 6 h after the immunization. Paraffin sections of samples were detected using the steptavidin-peroxidase method. Protein expression was detected using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and western blotting. PaO2 in the LPS group was significantly lower than that in the control rats. Activation of GABA-mediated signaling by GABA increased the expression of GABA(A)R in airway bronchial and alveolar epithelial cells. Blockade of the GABA(A)R by bicuculline limited the expression of this receptor. The GABA group rats had higher levels of tissue TNF-α and IL-6 than in ALI rats and control rats. The BIC group rats demonstrated an opposite expression level compared to the GABA group rats. Our results suggest that the GABA(A)R could aggravate the inflammatory response syndrome and oxidative stress in the lungs and play an essential role in LPS-induced acute lung injury. It provides a novel method to study the incidence and mortality of ALI during the peroperative period.