Objective To study the effect of hypothermia on cerebral mitochondrial respiratory function and ultrastructure after traumatic brain injury(TBI). Methods Sprague-Dawley rats were subjected to moderate brain injury by using lateral fluid-percussion(LFP)and randomly divided into sham operation group,normothermic TBI group(rectal temperature for 36-37℃)and hypothermic TBI group(rectal temperature for 31-32℃ lasting for two hours).The ipsilateral brains were dissected and homogenized brain tissues were extracted to obtain mitochondfia by density-centrifugation and speed-centrifugation at 2,24 hours and at days 3 and 7 after TBI.The mitochondrial uhrastructure was studied by electron microscope.The indices of respiratory control rate(RCR)and P/O ratio of mitochondrial respiratory function were measured after oxygen consumption was determined with a Clark-type electrode.Results The mitochondrial uhrastructure of normothermic TBI group was damaged severely while that of hypothermic TBI group kept relatively integrated.The RCR and P/O ratio were markedly decreased two hours after TBI and reached the lowest level at the 24th hour(P＜0.01).At day 7,RCR kept at a lower level compared with sham operation group but P/O ratio recovered to normal.Change of RCR was similar in hypothermie TBI group and normothermic TBI group.However,RCR of the hypothermic TBI group was significantly higher than that of the normothermic TBI group within three days after TBI.In the meantime,P/O ratio recovered to normal three days after TBI. Conclusion Hypothermia can improve cerebral mitochondrial respiratory function and protect the mitochondrial structure after TBI.

Objective To investigate effect of taurine on respiration chain enzyme activity of mitochondria 24 hours after severe traumatic brain injury (TBI) in rats.Methods Fifty-six SD rats were divided into sham group,TBI group,taurine treatment group,and taurine prevention group according to the random number table,with 14 rats per group.Fluid percussion brain injury models were used.Via the caudal vein,normal saline was administered to animals in sham and traumatic brain injury groups immediately after injury,while taurine (200 mg/kg)was administered to animals in taurine treatment group after injury and in taurine prevention group 4 days before injury.Brains were harvested 24 hours postinjury for assays of HE staining and electron microscopy.Mitochondrial respiratory chain complex Ⅰ-Ⅴ activities were detected.Results TBI group presented swelling neurocytes,cell loss,karyopyknosis,shortened even vanished process,and inflammation cell infiltration at the edge of necrosis in HE staining.By contrast,morphological improvement was significant in taurine treatment group but only some neurons were intact in taurine prevention group.Swelling mitochondria and broken or vanished mitochondrial crests were seen in TBI group under the electron microscope.However,normal or minor swelling mitochondria was seen in taurine treatment group and cytoplasm slightly porous and absence of mitochondrial crests were seen in taurine prevention group.Activities of complex Ⅰ,Ⅱ and Ⅴ were significant lower in TBI group (32.52±2.41,4.68 ±0.15,2.49 ±0.73) compared to those in sham group (34.03 ±0.46,5.04 ±0.29,3.20±0.68) and in taurine treatment group (33.95±0.85,5.12-±0.23,3.53 ±0.48) (P＜0.05).And complex Ⅰ in taurine prevention group was significantly enhanced as well (34.44 ± 0.36,P ＜ 0.05).Conclusion Taurine may protect the brain tissues and mitochondrial structure from impairment in TBI rats by improving mitochondrial enzymes activity and reducing secondary energy loss.

Objective To investigate the effect of mild hypothermia on neuroprotection and prognosis prediction of rats with traumatic brain injury (TBI) by dynamically monitoring the somatosensory evoked potentials (SEP) and quantitative electroencephalogram (QEEG).Methods Forty healthy adult male SD rats were randomly divided into four groups according to random number table,ie,normal control group (with no intervention),sham operation group (fenestration only,without drilling),TBI group (fluid percussion was used to produce moderate to severe TBI),and mild hypothemia group (ice blanket was used immediately after TBI for continuous physical cooling and rectal temperature was maintained at 32-35℃ and rewarmed to 37℃ 6 hours after the initiation of cooling),with 10 rats per group.Changes of SEP and QEEG in all groups were monitored at 6,24 hours,and 7 days after TBI.Results (1) Compared with TBI group,the latency of SEP waves (P1 and N1) on the injured side in mild hypothemia group began to shorten at 24 hours(P ＜ 0.05) and were close to that in the sham operation group at 7 days.(2) Except for normal control group and sham operation group,QEEG in TBI group showed decrease of α rhythm,increase of reactivity slow waves,and decrease or disappearance of QEEG relative power spectral values at all time points.In mild hypothermia group,the reactivity slow waves were decreased with a small amount of α wave; QEEG relative power spectral values were increased at 24 hours and 7 days (especially at 24 hours),but werc still lower than those in normal control group (P ＜ 0.05).Conclusion Mild hypothermia exerts neuroprotective effect through reducing SEP latency,raising relative power spectral values of QEEG,and improving the nerve conduction and brain electrical activity of the injured side.

Objective To inhibit the proliferation and metastasis of colon cancer cells by increasing the expression level of B-cell translocation gene-2 (BTG2).Methods Western blot assay was used to detect the expression level of BTG2 protein in the normal intestinal epithelial HIEC cells and three colon cancer cell lines SW620, HT-29 and LS174T.The expression of BTG2 protein in normal colonic epithelial tissue, colon adenoma and colon cancer tissue was detected by immunohistochemistry.The plasmid with BTG2 gene full-length sequence was transfected into colon cancer SW620 cells, and the expression of BTG2 protein was detected by Western blot.The cell growth curve was drawn by MTT test.The Ki-67-positive rate was calculated using immunofluorescence staining.The cell migration of colon cancer cells was detected by scratch test and Transwell double chamber culture system, and the pseudopodia growth of tumor cells was detected by Matrigel 3D culture system.Results Western blot results showed that BTG2 relative expression levels were 0.83±0.12,0.18±0.04, 0.20±0.05 and 0.36±0.07 in normal human intestinal epithelial cells HIEC, and human colon cancer cell line SW620, HT-29 and LS174T, respectively.The results of immunohistochemistry showed that the positive expression of BTG2 protein in normal colorectal tissue, colorectal adenoma and colorectal carcinoma tissues were 82.5%(33/40), 77.5%(31/40) and 17.5%(7/40), respectively, with a significant difference between two groups (P<0.05).Immunofluorescence results showed that the positive rate of Ki-67 in the control group, empty vector group and BTG2 transfection group was (76.2± 8.0)%, (81.4±9.7)%and (50.1±7.1)%, respectively, showing a significant difference between two groups ( P<0.05 ) .The scratch test results showed that in the control group, empty vector group and BTG2 transfection group , the distance of SW620 cells between two sides was ( 79.27 ±11.24) μm, ( 80.65 ± 12.17) μm and (124.77±19.63) μm, respectively, with a significant difference between two groups ( P<0.05) .Transwell results showed that in the control group, empty plasmid group and BTG2 transfection group, the SW620 cell migration rate was (78.5±13.1)%, (73.2±12.9)%and (47.4±9.1)%,respectively, showing a significant difference between two groups ( P<0.05) .The number of neurospheres of BTG2 transfection group was decreased SW620, which had poor ductility.Conclusion s BTG2 gene is involved in colon cancer cell proliferation and metastasis , and effectively restores the function of BTG2 protein.Therefore, it may be expected to become a new option in gene therapy for colon cancer.

Objective To inhibit the proliferation and metastasis of colon cancer cells by increasing the expression level of B-cell translocation gene-2 (BTG2).Methods Western blot assay was used to detect the expression level of BTG2 protein in the normal intestinal epithelial HIEC cells and three colon cancer cell lines SW620, HT-29 and LS174T.The expression of BTG2 protein in normal colonic epithelial tissue, colon adenoma and colon cancer tissue was detected by immunohistochemistry.The plasmid with BTG2 gene full-length sequence was transfected into colon cancer SW620 cells, and the expression of BTG2 protein was detected by Western blot.The cell growth curve was drawn by MTT test.The Ki-67-positive rate was calculated using immunofluorescence staining.The cell migration of colon cancer cells was detected by scratch test and Transwell double chamber culture system, and the pseudopodia growth of tumor cells was detected by Matrigel 3D culture system.Results Western blot results showed that BTG2 relative expression levels were 0.83±0.12,0.18±0.04, 0.20±0.05 and 0.36±0.07 in normal human intestinal epithelial cells HIEC, and human colon cancer cell line SW620, HT-29 and LS174T, respectively.The results of immunohistochemistry showed that the positive expression of BTG2 protein in normal colorectal tissue, colorectal adenoma and colorectal carcinoma tissues were 82.5%(33/40), 77.5%(31/40) and 17.5%(7/40), respectively, with a significant difference between two groups (P<0.05).Immunofluorescence results showed that the positive rate of Ki-67 in the control group, empty vector group and BTG2 transfection group was (76.2± 8.0)%, (81.4±9.7)%and (50.1±7.1)%, respectively, showing a significant difference between two groups ( P<0.05 ) .The scratch test results showed that in the control group, empty vector group and BTG2 transfection group , the distance of SW620 cells between two sides was ( 79.27 ±11.24) μm, ( 80.65 ± 12.17) μm and (124.77±19.63) μm, respectively, with a significant difference between two groups ( P<0.05) .Transwell results showed that in the control group, empty plasmid group and BTG2 transfection group, the SW620 cell migration rate was (78.5±13.1)%, (73.2±12.9)%and (47.4±9.1)%,respectively, showing a significant difference between two groups ( P<0.05) .The number of neurospheres of BTG2 transfection group was decreased SW620, which had poor ductility.Conclusion s BTG2 gene is involved in colon cancer cell proliferation and metastasis , and effectively restores the function of BTG2 protein.Therefore, it may be expected to become a new option in gene therapy for colon cancer.

OBJECTIVETo inhibit the proliferation and metastasis of colon cancer cells by increasing the expression level of B-cell translocation gene-2 (BTG2).

METHODSWestern blot assay was used to detect the expression level of BTG2 protein in the normal intestinal epithelial HIEC cells and three colon cancer cell lines SW620, HT-29 and LS174T. The expression of BTG2 protein in normal colonic epithelial tissue, colon adenoma and colon cancer tissue was detected by immunohistochemistry. The plasmid with BTG2 gene full-length sequence was transfected into colon cancer SW620 cells, and the expression of BTG2 protein was detected by Western blot. The cell growth curve was drawn by MTT test. The Ki-67-positive rate was calculated using immunofluorescence staining. The cell migration of colon cancer cells was detected by scratch test and Transwell double chamber culture system, and the pseudopodia growth of tumor cells was detected by Matrigel 3D culture system.

RESULTSWestern blot results showed that BTG2 relative expression levels were 0.83 ± 0.12, 0.18 ± 0.04, 0.20 ± 0.05 and 0.36 ± 0.07 in normal human intestinal epithelial cells HIEC, and human colon cancer cell line SW620, HT-29 and LS174T, respectively. The results of immunohistochemistry showed that the positive expression of BTG2 protein in normal colorectal tissue, colorectal adenoma and colorectal carcinoma tissues were 82.5% (33/40), 77.5%(31/40) and 17.5% (7/40), respectively, with a significant difference between two groups (P < 0.05). Immunofluorescence results showed that the positive rate of Ki-67 in the control group, empty vector group and BTG2 transfection group was (76.2 ± 8.0)%, (81.4 ± 9.7)% and (50.1 ± 7.1)%, respectively, showing a significant difference between two groups (P < 0.05). The scratch test results showed that in the control group, empty vector group and BTG2 transfection group, the distance of SW620 cells between two sides was (79.27 ± 11.24) µm, (80.65 ± 12.17) µm and (124.77 ± 19.63) µm, respectively, with a significant difference between two groups (P < 0.05). Transwell results showed that in the control group, empty plasmid group and BTG2 transfection group, the SW620 cell migration rate was (78.5 ± 13.1)%, (73.2 ± 12.9)% and (47.4 ± 9.1)%, respectively, showing a significant difference between two groups (P < 0.05). The number of neurospheres of BTG2 transfection group was decreased SW620, which had poor ductility.

CONCLUSIONSBTG2 gene is involved in colon cancer cell proliferation and metastasis, and effectively restores the function of BTG2 protein. Therefore, it may be expected to become a new option in gene therapy for colon cancer.

B-Lymphocytes ; physiology ; Cell Cycle ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; genetics ; Colonic Neoplasms ; Genetic Vectors ; Humans ; Immediate-Early Proteins ; genetics ; Immunohistochemistry ; Plasmids ; Transfection ; Tumor Suppressor Proteins ; genetics

【Objective】 To analyze the difference of circulating threshold (Ct) of polymerase chain reaction (PCR) in blood station laboratories during the external quality assessment, and to put forward suggestions for the quality improvement of participating laboratories. 【Methods】 From 2018 to 2021, the blood station laboratories participated in the external laboratory quality assessment of CITIC including blood screening items with nucleic acid testing method. The data of Roche diagnostic reagent group were used as the source, and the detected Ct values of three groups of quality control samples of HBV A subtype (400 IU/mL), HCV 1b subtype (400 IU/mL) and HIV B genotype (500 IU/mL) were used as the objects. The data were grouped according to quality control (sample) batches, reagent batches and different laboratories. Using the statistical method of variance analysis (assuming P<0.05 as significant), the detected Ct value of each group was analyzed. 【Results】 For the three items (HBV/HCV/HIV), the grouping data involving 42 batches of quality control (13/12/17), 28 batches of reagent (11/8/9) and 57 laboratories (19/19/19) were selected. The grouping analysis of quality assessment batches shows that there was no significant difference between HBV and HCV quality assessment batches, and there was no significant difference between other HIV batches except the two batches of HIV quality assessment samples released in 2021. The grouping analysis of each reagent batch showed that there was no significant difference between each reagent batch for HCV and HIV detection, while there was significant difference between two batches of HBV reagents. After excluding the data groups with significant differences in the quality control batch groups and the reagent batch groups, the detected Ct value of each laboratory group had extremely significant differences in the three items of HBV, HCV and HIV. Through pairing analysis, it was found that four laboratories had significant differences with most other laboratories in the three items, mainly manifested in the high mean value of Ct. 【Conclusion】 For the blood station laboratories with correct test results of quality assessment samples, there are differences in Ct values detected by PCR, which may be mainly caused by the detection ability of the participating laboratories.