ABSTRACT
The development of speech is a process by which the neural network structure of brain perceives, decodes, represents, and outputs input signals. At the cortical level, the classic model of speech processing proposed two pathways leading from the auditory system: the ventral stream and the dorsal stream.The ventral stream, which involved structures in the superior and middle portions of the temporal lobe, was involved in processing speech signals for perception and comprehension (speech recognition). The dorsal stream, which involved structures in the posterior frontal lobe and the posterior dorsal-most aspect of the temporal lobe and parietal operculum, had an auditory-motor integration function and was essential for speech production. However, the importance of auditory processing in central auditory nervous system(CANS) from the vestibulocochlear nerve to the auditory cortex for speech development had not been clarified.This review aims to discuss the roles and related mechanisms of the CANS in speech recognition and generation from the perspective of cognitive neuroscience, so as to provide new ideas for clinical monitoring and long-term prediction of auditory processing and speech development, and for diagnosis and treatment of clinical speech-related diseases.
ABSTRACT
@#Cardiotoxicity of cancer chemotherapeutics has received considerable attention in recent years.However, the effects of chemotherapy on cardiometabolic perturbation with lung injury have rarely been reported. Thus, we constructed a mouse model of myocardial injury superimposed on lung injury with a combination of bleomycin (BLM) and doxorubicin (DOX).C57BL/6J mice were randomly divided into four groups: control group (CON), BLM group (intratracheal infusion with single doses of 5 mg/kg), DOX group (intraperitoneal injection of 7.5 mg/kg/week, two weeks) and DOX+BLM group. The cardiac injury of mice was evaluated by serum biochemical parameters and histopathology.Cardiometabolic perturbation was investigated using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography with tandem mass spectrometry (LC-MS).The results showed that, compared with the CON group, BLM alone caused lung injury yet with no significant effects on the cardiometabolic profile; DOX alone had significant perturbations in the cardiometabolic profile, and the main differential metabolites were amino acids, fatty acids, phospholipids, etc.; the combination of BLM and DOX caused more severe disturbance of cardiometabolic homeostasis in mice, especially accumulation of branched-chain amino acids.This study confirmed that DOX can lead to more significant changes in the cardiometabolic profile in the presence of lung injury, with an initial focus on the branched-chain amino acid metabolic pathway.This research provides scientific data for in-depth study of the cardiotoxicity mechanism of chemotherapeutic agents.
ABSTRACT
Objective To observe the effect of hypoxia on the expression of epithelial growth factor receptor (EGFR) and cell apoptosis of breast and cervical cancer xenografts in nude mouse models.Methods The nude mouse models with MCF-7 and HeLa xenografts were established.The degree of hypoxia and EGFR expression were observed by confocal microscopy.The influence of EGFR expression on cell apoptosis under hypoxia was observed by TUNEL assay.Results EGFR expression was either up-regulated or down-regulated in the MCF-7 and HeLa cells with high degree of hypoxia.Furthermore,the degree of apoptosis was reduced in tumor tissues with high EGFR expression compared with that in those with low expression of EGFR.Conclusion The hypoxia in MCF-7 and HeLa cells exerts heterogeneous effect on EGFR expression.Under hypoxic conditions,EGFR exoression is negatively correlated with cell apoptosis.