Detection of epidermal growth factor receptor mutations in non-small cell lung cancer by immunohistochemistry / 中南大学学报(医学版)

OBJECTIVES@#To evaluate the sensitivity and specificity of immunohistochemistry (IHC) for detecting common epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) and to estimate the cost-effectiveness of IHC testing.@*METHODS@#A total of 208 NSCLC patients were included in the trial, and the EGFR mutation status in the patients were detected by PCR and IHC. Two mutation-specific antibodies against the most common exon 19 deletion (clone SP111) and exon 21 L858R mutation (clone SP125) were tested by using automated immunostainer. A cost-effectiveness analysis model was built for the analysis of optimal detection scheme.@*RESULTS@#With a cutoff value of IHC 1+, the overall sensitivity and specificity of the IHC-based method compared with the PCR-based method were 81.7% (95% CI 72.4% to 89.0%) and 94.7% (95% CI 92.6% to 99.5%), respectively. EGFR 19del mutation was detected by SP111 antibody with a sensitivity of 65.9% (95% CI 49.4% to 79.9%) and specificity of 98.8% (95% CI 95.7% to 99.9%). EGFR L858R mutation was detected by SP125 antibody with a sensitivity of 94.2% (95% CI 84.1% to 98.8%) and specificity of 99.4% (95% CI 96.5% to 100%). The IHC and PCR cost ratio needed to be 1-to-3 or more in our patients to economically justify before the use of IHC.@*CONCLUSIONS@#The study confirms an excellent specificity with fairly good sensitivity of IHC and mutation-specific antibodies for common EGFR mutations. It is cost-effective to use IHC method to detect EGFR mutation first when the IHC and PCR cost ratio is 1-to-3 or more in Chinese populations.

Role of tumor necrosis factor-alpha in spinal cord injury of rabbits with decompression sickness / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the pathological changes in rabbits with spinal cord injury induced by decompression sickness (DCS), and to investigate the role of tumor necrosis factor-alpha (TNF-α) in spinal cord injury induced by DCS.</p><p><b>METHODS</b>Rabbits were randomly divided into normal control group, DCS group, and safe decompression group. The rabbit model of DCS was established. Light microscopy, real-time PCR, and immunohistochemical method were used to observe the pathomorphological changes in the thoracolumbar spinal cord and the mRNA and protein expression of TNF-α, respectively. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to observe the apoptosis in the spinal cord.</p><p><b>RESULTS</b>In the DCS group, cavities formed in the white matter of spinal cord and gliosis occurred around necrotic areas. Moreover, the mRNA and protein expression of TNF-α was significantly higher in the DCS group than in the normal control group and the safe decompression group (P<0.01). The results of TUNEL showed that the number of positive apoptotic cells was significantly larger in the DCS group than in the normal control group and the safe decompression group (P<0.05).</p><p><b>CONCLUSION</b>Apoptosis plays an important role in spinal cord injury induced by DCS. In the early stage of DCS, the massive release of TNF-α initiates apoptosis and contributes to the pathological changes in spinal cord injury induced by DCS.</p>

Changes in levels of TNF-α and GFAP in brain and spinal cord of rabbits with decompression disease / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the changes in expression of tumor necrosis factor-alpha (TNF-α) and glial fibrillary acidic protein (GFAP) in rabbits with decompression disease (DCS), and to investigate the functioning mechanism.</p><p><b>METHODS</b>A total of 21 healthy adult rabbits were randomly divided into 3 groups: normal control group, DCS group, and safe relief group, with 7 rabbits in each group. A rabbit DCS model was established by quick decompression. The changes in pathological morphology and mRNA and protein expression of TNF-α and GFAP in the brain and spinal cord of rabbits with DCS were determined by light microscopy, real-time PCR, and immunohistochemistry, respectively.</p><p><b>RESULTS</b>Cavity formation was observed in the white matter of spinal cord in DCS group. The mRNA and protein expression of TNF-α and GFAP was significantly higher in the DCS group than in the normal control group and safe relief group (P < 0.01), while no significant differences were observed in the brain (P > 0.05).</p><p><b>CONCLUSION</b>Spinal cord is the main part of central nervous system injury in DCS. Activation of TNF-α and GFAP genes accompanied by increase in their protein expression can be observed at the early stage of DCS. The astrocytes and TNF-α play important roles in the process of spinal cord injury in DCS.</p>