[CT texture analysis for predicting pseudoprogression in metastatic clear cell renal cell carcinoma during PD-1 inhibitor therapy].

Objective: To evaluate the effectiveness of enhanced CT texture feature analysis in predicting pseudoprogression in patients with metastatic clear cell renal cell carcinoma (mccRCC) undergoing programmed cell death protein 1 (PD-1) inhibitor therapy. Methods: A cross-sectional study. Data from 32 patients with mccRCC were retrospectively collected who received monotherapy with PD-1 inhibitors after standard treatment failure at Henan Cancer Hospital, from June 2015 to January 2021. Clinical information and enhanced CT images were analyzed to assess target lesion response. The lesions were divided into pseudoprogression and non-pseudoprogression groups. Manual segmentation of target lesions was performed using ITK-Snap software on baseline enhanced CT, and texture analysis was conducted using A.K. software to extract feature parameters. Differences in texture features between the pseudoprogression and non-pseudoprogression groups were analyzed using univariate and multivariate logistic regression. A predictive model for pseudoprogression was constructed, and its performance was evaluated using ROC curve analysis. Results: A total of 32 patients with 89 lesions were included in the study. Statistical analysis revealed significant differences in seven texture features between the pseudoprogression and non-pseudoprogression groups. These features included"original_ngtdm_Strength"(0.49 vs. -0.61,P=0.006), "wavelet-HLH_glszm_ZonePercentage"(0.67 vs. -0.22,P=0.024),"wavelet-LHL_ngtdm_Strength"(1.20 vs. -0.51,P=0.002), "wavelet-HLL_gldm_LargeDependenceEmphasis"(-0.84 vs. 0.19,P=0.002), "wavelet-HLH_glcm_Id" (-0.30 vs. 0.43,P=0.037),"wavelet- HLH_glrlm_RunPercentage"(0.45 vs. -0.01,P=0.032),"wavelet-LHH_firstorder_Skewness"(0.25 vs. -0.27, P=0.011). Based on these features, a pseudoprogression prediction model was developed with a P-value of 0.000 2 and an odds ratio of 0.045 (95%CI 0.009-0.227). The model exhibited a high predictive performance with an AUC of 0.907 (95%CI 0.817-0.997) according to ROC curve analysis. Conclusions: Enhanced CT texture feature analysis shows promise in predicting lesion pseudoprogression in patients with metastatic ccRCC undergoing PD-1 inhibitor therapy. The developed predictive model based on texture features demonstrates good performance and may assist in evaluating treatment response in these patients.

[Focus on the development of preimplantation genetic testing in the field of birth defects and rare diseases prevention and control].

Birth defects and rare diseases are serious challenges in China and even in the world, and most of them lack effective treatment. Preimplantation genetic testing (PGT) prevents the occurrence of this kind of disease at the source by carrying out genetic testing in the preimplantation stage and selecting normal embryos for transplantation. In this paper, the methods of PGT for birth defects and rare diseases and their latest progress are described.

[Bladder cancer local staging about muscle invasion: 3.0T MRI performance following transurethral resection].

OBJECTIVE: To evaluate the performance of 3.0T magnetic resonance imaging examination (MRI) for the local detecting of muscle invasive bladder cancer following transurethral resection of bladder tumor (TURBT). METHODS: Retrospective study identified 55 patients with pathology-proven bladder cancer who underwent transurethral resection of bladder tumor followed by 3.0T magnetic resonance imaging between September 2012 and April 2019 in our hospital. Two radiologists reviewed pelvic magnetic resonance imaging together and judged muscle invasive bladder cancer. Sensitivity, specificity and accuracy were calculated for the presence of muscle invasion by T2 weighted imaging (T2WI) only, diffusion-weighted imaging (DWI) only and T2WI+DWI compared with the findings at radical cystectomy as the reference standard. RESULTS: Of the 55 patients with pathological results from radical cystectomy, 3.64% (2/55) had no residual disease; 29.09% (16/55) were non-muscle invasive bladder cancer on pathology, including 13 cases in T1 and 3 cases in Ta; 34.55% (19/55) were in stage T2 depending on pathology, 25.45% (14/55) in T3, and 7.27% (4/55) in T4. The average age was 60.76 years, ranging from 42 to 82 years. There were 48 males and 7 females in our study. Before pelvic MRI examination, all the patients received transurethral resection of bladder tumor, including 16 cases taking the operation in our hospital and 39 cases in other hospitals. The interval between the pelvic MRI examination and transurethral resection of bladder tumor was more than 2 weeks in all the patients. They all underwent radical cystectomy within 1 month after the pelvic MRI examination, and no patient underwent radiotherapy or chemotherapy in our study during the interval between the MRI examination and radical cystectomy. T2WI only, DWI only, and T2WI+DWI of 3.0T magnetic resonance imaging for readers were with sensitivity: 94.59%, 83.78%, 91.89%; with specificity: 66.67%, 77.78%, 72.22% and with accuracy: 85.45%, 81.82%, 85.45%, respectively. CONCLUSION: 3.0T MRI may have a role in diagnosing muscle invasive bladder cancer following TURBT. T2WI has the advantage of detecting the location of bladder tumor, and DWI has the advantage of differentiating between the benign and malignant lesion. 3.0T MRI T2WI+DWI has a good utility in the detection of muscle invasive bladder cancer following TURBT with satisfied accuracy.

[Detection and comparison of fiber count concentration in processing environment of asbestos and man-made mineral fiber].

Objective: To connect with the measurement data of asbestos dust fiber concentration in foreign countries, improve the accuracy of asbestos fiber detection in China, and understand the dust exposure in the working environment of asbestos and man-made mineral fiber production and processing sites in Zhejiang Province. The fiber count concentrations of working environment in glass fiber, ceramic fiber and asbestos processing plants were measured and compared. Methods: The dust concentration in the working environment of two glass fiber factories, one ceramic fiber factory and eight asbestos products processing factories was measured. The total dust mass concentration was measured according to GBZ/T 192.1-2007, and the fiber count concentration was measured by phase contrast microscope. Kruskal Wallis was used to test and compare the dust concentration in the working environment of each post. The correlation between asbestos mass concentration and fiber count concentration was analyzed by Spearman correlation. Results: Under the phase contrast microscope, there were many short and fine asbestos fibers in the field of vision, and there were many impurities around. The average dust concentration of asbestos processing plant was 3.2 f/ml, and the dust concentration of cotton ginning was the highest (6.68 f/ml) . There was a significantly positive correlation between asbestos fiber count concentration and mass concentration (r=0.535, P=0.033) . The average fiber count concentration of glass fiber factory was 0.001 f/ml, and the highest was 0.005 f/ml. The average fiber count concentration of ceramic fiber factory was 0.001 f/ml, and the highest was 0.006 f/ml. Conclusion: The fiber count concentration in the working environment of asbestos factory in Zhejiang Province is obviously over the standard, which is one of the important reasons for the high incidence of mesothelioma in this area. Short and small asbestos fibers are easy to be ignored when counting. It is necessary to improve the actual operation process of fiber counting to form a laboratory standard in China.

[Value of readout-segmented echo-planar diffusion imaging on 3.0 T MRI for predicting the early efficacy of concurrent radiochemotherapy of advanced stage nasopharyngeal carcinoma patients].

Objective: To discuss the value of RESOLVE for predicting early therapeutic effect of concourrent radiochemotherapy in advanced stage nasopharngeal carcinoma patients. Methods: Sixty-eight patients with nasopharyngeal carcinoma were confirmed by pathology in Henan Cancer Hospital from June 2014 to January 2016.All patients underwent RESLOVE(b value=800 s/mm(2)) with a 3.0 T MRI scanner.The ADC value and the area of the tumor was measured before treatment and 2 weeks after treatment independently performed by two radiologists with 5 years experiences and the agreement evaluation was performed using ANOVA analysis.The correlation among pretreatment ADC value, pathology type, gender, tumor area and the tumor regression rate were analyzed using Spearman rank correlation test.The difference between pretreatment ADC value was compared in CR group and non-CR group by independent sample t test.ROC curve was drawn and the maximum Youden index value was the cutoff calculating the ADC value and predicting the sensitivity, specificity and area under the curve. Results: (1)The agreement between 2 radiologist was excellent. The ICC values of the ADC and the area of the tumor before treatment and the area of the tumor after treatment were 0.89, 0.92 and 0.95, respectively. (2)The pretreatment ADC values of the CR group and the non-CR group were (0.877±0.103)×10(-3) mm(2)/s and (0.779±0.078)×10(-3) mm(2)/s, respectively. There was statistical difference t value=2.874, P value=0.005.(3)ROC curve showed that the sensitivity and specificity of the pretreatment ADC value in predicting CR was 85.2% and 71.0%, with the cut-off value of 0.792×10(-3) mm(2)/s, and the area under curve was 0.778.(4)There was apparently correlation beween the pretreatment ADC value and the tumor regression rate(r=0.333, P=0.006). There was no correlation among pretreatment ADC value, pathology type, gender and tumor area (P>0.05). Conclusion: There is important value using the pretreatment ADC value measured by RESOLVE for predicting the early effect of concurrent radiochemotherapy in advanced stage nasopharngeal carcinoma patients.

Selecting key genes associated with osteosarcoma based on a differential expression network.

Despite recent advances in osteosarcoma diagnosis and therapy, much remains unclear about the molecular mechanisms involved in the disorder, and the discovery of novel drug-targeted genes is essential. We explored the potential molecular mechanisms and target genes involved in the development and progression of osteosarcoma. First, we identified the differentially expressed genes in osteosarcoma patients and matching normal controls. We then constructed a differential expression network based on differential and non-differential interactions. Pathway-enrichment analysis was performed based on the nodes contained in the main differential expression network. Centrality analysis was used to select hub genes that may play vital roles in the progression of human osteosarcoma. Our research revealed a total of 176 differentially expressed genes including 82 upregulated and 94 downregulated genes. A differential expression network was constructed that included 992 gene pairs (1043 nodes). Pathway-enrichment analysis indicated that the nodes in the differential expression network were mainly enriched in several pathways such as those involved in cancer, cell cycle, ubiquitin-mediated proteolysis, DNA replication, ribosomes, T-cell receptor signaling, spliceosomes, neurotrophin signaling, oxidative phosphorylation, and tight junctions. Six hub genes (APP, UBC, CAND1, RPA, YWHAG, and NEDD8) were discovered; of these, two genes (UBC and RPA) were also found to be disease genes. Our study predicted that UBC and RPA had potential as target genes for the diagnosis and treatment of osteosarcoma.

Non-invasive assessment of liver fibrosis using real-time tissue elastography in patients with chronic hepatitis B.

AIM: To evaluate the utility of the elastic ratio calculated using real-time tissue elastography for assessing liver fibrosis in patients with chronic hepatitis B (CHB). MATERIALS AND METHODS: Ninety-six patients with CHB were enrolled between September 2012 and August 2013. The elastic ratio of the liver for the intrahepatic venous small vessel was calculated to measure liver stiffness. Diagnostic performance of the elastic ratio and aminotransferase-to-platelet ratio index (APRI) were compared with histological fibrosis stage at liver biopsy. In addition, 45 healthy adult volunteers were participated in intra- and interobserver reliability studies. RESULTS: There was no significant influence of hepatitis B e antigen (HBeAg) status or hepatitis B virus DNA levels on the elastic ratio measurements in CHB patients. The elastic ratio was significantly correlated with histological fibrosis stage (r = 0.873, p < 0.001). Cut-off values were 2.62 for stage 2 and over (S ≥ 2), 3.20 for state 3 and over, and 3.86 for stage 4, respectively. The areas under the receiver operating characteristic (ROC) curves for elastic ratio and APRI diagnosis of significant fibrosis (S ≥ 2) was 0.91 (95% CI: 0.84-0.98) and 0.71 (95% CI: 0.57-0.86), and 0.94 (95% CI: 0.89-0.99) and 0.81 (95% CI: 0.71-0.91) for cirrhosis (S = 4), respectively. The elastic ratio measurements had good reproducibility: 0.838 for intra-observer reliability and 0.805 for inter-observer reliability, respectively (p < 0.001). CONCLUSION: Elastic ratio determined using real-time tissue elastography was an accurate and reproducible method for evaluating liver fibrosis in patients with CHB.

Mesoporous SnO2@carbon core-shell nanostructures with superior electrochemical performance for lithium ion batteries.

SnO2@carbon nanostructure composites are prepared by a simple hydrothermal method. The composite exhibits unique structure, which consists of a mesoporous SnO2 core assembled of very small nanoparticles and a carbon shell with 10 nm thickness. The mesoporous SnO2@carbon core-shell nanostructures manifest superior electrochemical performance as an anode material for lithium ion batteries. The reversible specific capacity of the composite is about 908 mAh g(-1) for the first cycle and it can retain about 680 mAh g(-1) after 40 charge/discharge cycles at a current density of 0.3 C. Moreover, it shows excellent rate capability even at the high rate of 4.5 C. The enhanced performance was attributed to the mesoporous structure and a suitable carbon coating.

Cystic fibrosis transmembrane conductance regulator protein expression rate in healthy spermatozoa is not correlated with ovum fertilisation rate.

Our previous studies have shown that the cystic fibrosis transmembrane conductance regulator (CFTR) was important for capacitation and fertilisation in mouse, guinea pig and human spermatozoa. However, it is unclear whether CFTR is correlated with ovum fertilisation rate. The present study was to test the possible relationship between spermatozoa CFTR protein expression rate in healthy men and ovum fertilisation rate during in vitro fertilisation. Ninety-four couples for female factor infertility for IVF-ET treatments were retrospectively studied. All the patients were divided into three groups based on the fertilisation rate of ovum in vitro. It was performed to explore whether there were differences in sperm CFTR protein expression rate among the three groups and the relevance between CFTR protein expression rate and ovum fertilisation rate. Our study showed that there was no significant differences in sperm CFTR protein expression rate among the three groups (F = 0.614, P = 0.544), and the relevance between spermatozoa CFTR protein expression rate and ovum fertilisation rate was not significantly different (r = 0.013, P = 0.904). These results further suggest that CFTR protein expression rate in healthy men spermatozoa was not associated with ovum fertilisation rate and thus we cannot predict ovum fertilisation results by sperm CFTR protein expression rate.

[Effects of vaccines on the viral negative conversion of children with COVID-19].

Objective: To explore the effect of vaccination on viral negative conversion of children with COVID-19. Methods: A retrospective cohort study was conducted. A cohort of 189 children aged 3-14 years with COVID-19 admitted to Renji Hospital (South branch) of Shanghai Jiao Tong University School of Medicine from April 7th to May 19th 2022 was enrolled in the study. According to the vaccination status, the infected children were divided into an unvaccinated group and a vaccinated group. Age, gender, severity, clinical manifestations, and laboratory tests, etc. were compared between groups, by rank sum test or chi-square test. The effects of vaccination on viral negative conversion were analyzed by a Cox mixed-effects regression model. Additionally, a questionnaire survey was conducted among the parents of unvaccinated children to analyze the reasons for not being vaccinated. Results: A total of 189 children aged 3-14 years were enrolled, including 95 males (50.3%) and 94 females (49.7%), aged 5.7 (4.1,8.6) years. There were 117 cases (61.9%) in the unvaccinated group and 72 cases (38.1%) in the vaccinated group. The age of the vaccinated group was higher than that of the unvaccinated group (8.8 (6.8, 10.6) vs. 4.5 (3.6, 5.9) years, Z=9.45, P<0.001). No significant differences were found in clinical manifestations, disease severity, and laboratory results between groups (all P>0.05), except for the occurrence rate of cough symptoms, which was significantly higher in the vaccinated group than in the non-vaccinated group (68.1% (49/72) vs. 50.4% (59/117),χ2=5.67, P=0.017). The Kaplan-Meier survival curve and Cox mixed-effects regression model showed that the time to the viral negative conversion was significantly shorter in the vaccinated group compared with the unvaccinated group (8 (7, 10) vs. 11 (9, 12) d, Z=5.20, P<0.001; adjusted HR=2.19 (95%CI 1.62-2.97)). For questionnaire survey on the reasons for not receiving a vaccination, 115 questionnaires were distributed and 112 valid questionnaires (97.4%) were collected. The main reasons for not being vaccinated were that parents thought that their children were not in the range of appropriate age for vaccination (51 cases, 45.5%) and children were in special physical conditions (47 cases, 42.0%). Conclusion: Vaccination can effectively shorten the negative conversion time of children with COVID-19 and targeted programs should be developed to increase eligible children's vaccination rate for SARS-CoV-2 vaccination.

Associations of IL-18 and IL-9 expressions and gene polymorphisms with asthma.

OBJECTIVE: To explore the associations of interleukin-18 (IL-18) and IL-9 gene polymorphisms with susceptibility to asthma, and to study the associations between IL-18 and IL-9 expression levels and polymorphisms. PATIENTS AND METHODS: A total of 200 asthma patients in our hospital were collected as disease group, while 200 healthy people were taken as control group. The deoxyribonucleic acid (DNA) was extracted from peripheral blood and sent to the company for the detection of IL-18 and IL-9 gene polymorphisms via sequencing. The levels of serum IL-18 and IL-9 were determined using enzyme-linked immunosorbent assay (ELISA), and arterial blood gas analysis was performed for patients. RESULTS: The allele distributions at IL-18 gene loci rs189667 and rs360715 had no differences between control group and disease group. The allele distributions at IL-9 gene loci rs1859430 and rs2066758 were different between the two groups (p=0.001, p=0.022), among which the G allele frequency was the highest in disease group [245 (0.613)], and the T allele frequency was also the highest in disease group [240 (0.600)]. There was a difference in the genotype distribution at IL-9 gene locus rs1859430 between the two groups, and the GG genotype frequency in disease group [82 (0.410)] was significantly higher than that in control group (p=0.005). The CC genotype frequency at rs2066758 was significantly lower in disease group [27 (0.135), p=0.044]. In disease group, the frequency of heterozygous model CT (p=0.047) at IL-18 gene locus rs360715, and recessive model GA+AA (p=0.021) and heterozygous model GA (p=0.031) at IL-19 gene locus rs1859430 was significantly lower than that in control group. In disease group, the AC haplotype frequency at IL-18 gene loci rs189667 and rs360715 was evidently lower than that in control group (p=0.048). Disease group had evidently lower AT haplotype frequency (p=0.006) and evidently higher GT haplotype frequency (p=0.000) at IL-9 gene loci rs1859430 and rs2066758. Moreover, the level of serum IL-18 in patients with TT genotype at IL-18 gene locus rs360715 was higher than that in those with other genotypes in disease group (p<0.05), and the level of serum IL-9 in patients with AG genotype at IL-9 gene locus rs1859430 was also higher than that in those with other genotypes in disease group (p<0.05). There was a remarkable association between CT genotype at IL-18 gene locus rs360715 and partial pressure of oxygen (PaO2) (p=0.035), and between CC genotype at IL-9 gene locus rs2066758 and partial pressure of carbon dioxide (PaCO2) (p=0.041). CONCLUSIONS: The expression levels of serum IL-18 and IL-9 and their gene polymorphisms are significantly associated with asthma.

Effects of cyclooxygenase-2 non-selective and selective inhibitors on proliferation inhibition and apoptosis induction of esophageal squamous carcinoma cells.

The objective of this study is to investigate the effects of aspirin and nimesulide on cell proliferation, apoptosis and its potential mechanisms in EC9706 and EC109 esophageal squamous carcinoma cells. EC9706 and EC109 cells were incubated with varying concentrations of aspirin and nimesulide, and the effects on cell proliferation and apoptosis were monitored by 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide and flow cytometry. Reverse transcription-polymerase chain reaction and Western blot assays were used to investigate expression of Bcl-2 and Bax. Prostaglandin E2 production was measured by enzyme linked immunosorbent assay. Pretreatment with aspirin and nimesulide inhibited EC9706 and EC109 cell growth in a time and dose-dependent manner, accompanied with a decrease of prostaglandin E2 production. In EC9706 cells, the mechanism of aspirin and nimesulide induced growth inhibition was a consequence of cell cycle arrest at the G(0)/G(1) check point. In EC109 cells, growth arrest was by induction of apoptosis, associated with downregulation of Bcl-2, but not Bax. In conclusion, aspirin and nimesulide could inhibit cell proliferation and induce apoptosis in esophageal squamous carcinoma cells. Cyclooxygenase-2 inhibitor may be a promising therapeutic agent for human esophageal squamous cell carcinoma.

RUNX3 protects against acute lung injury by inhibiting the JAK2/STAT3 pathway in rats with severe acute pancreatitis.

OBJECTIVE: Acute lung injury (ALI) is the most common complication of severe acute pancreatitis (SAP) in the early stage, which causes systemic inflammatory response and organ damage. Human runt-associated transcription factor 3 gene (RUNX3) has been reported to participate in various inflammatory diseases. However, the exact role of RUNX3 in SAP and its-related ALI remains unclear. MATERIALS AND METHODS: To establish the model of SAP, rats were retrogradely injected with 5% sodium taurocholate (1 mg/kg body weight) into the biliary-pancreatic duct. Cytokine level in serum was measured by ELISA, and the polymorphonuclear neutrophil (PMN) was isolated from rat's blood 12 h-post SAP induction. RESULTS: We found RUNX3 expression was significantly decreased with the progression of SAP. Both pancreas damages and cytokine production abilities were reduced in RUXN3-overexpressed SAP rats compared with control rats. Moreover, SAP-associated ALI was also improved upon RUNX3 overexpression in SAP rats. RUNX3 upregulation enhanced PMN apoptosis and inhibited Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) phosphorylation. CONCLUSIONS: Our study indicates that RUNX3 protects against SAP and SAP-associated ALI through controlling PMN apoptosis and regulating JAK2/STAT3 signaling pathway. RUNX3 could be regarded as a potent therapeutic target in SAP for future studies.

MiR-431 suppresses proliferation and metastasis of lung cancer via down-regulating DDX5.

OBJECTIVE: We aimed to detect the role and function of microRNA-431 (miR-431) in lung cancer, and to investigate the underlying mechanism in regulating the development of lung cancer. PATIENTS AND METHODS: Quantitative Real-time polymerase chain reaction (qRT-PCR) was utilized to measure the relative expression level of miR-431 in lung cancer tissues and cell lines. Cell counting kit-8 (CCK-8) and colony formation assays were employed to measure the proliferative ability of lung cancer cells. Meanwhile, transwell assay was recruited to detect the invasive and migratory abilities of lung cancer cells. Furthermore, dual-luciferase reporter gene assay was designed to verify the target gene of miR-431. Western blot assay was used to gauge the protein level of DDX5 (DEAD box polypeptide 5). RESULTS: MiR-431 expression was significantly lower in 122 lung cancer tissue samples or cell lines compared to the adjacent normal tissues or lung bronchial epithelial cell line, respectively. Over-expression of miR-431 significantly inhibited proliferation, invasion and migration of A549 cells. Down-regulation of miR-431 accelerated cell growth and metastasis of H1650 cells. DDX5 was proved to be a direct target for miR-431 in lung cancer. CONCLUSIONS: MiR-431 expression decreased in lung cancer tissues and cells. MiR-431 suppressed proliferation, invasion and migration of lung cancer cells via inhibiting the expression of DDX5. Our study might provide a novel target for the biological therapy of lung cancer.

Expressions of HBV X gene regulated by different promoters and their effects on cell apoptosis.

OBJECTIVE: To investigate the difference in expression level of hepatitis B virus (HBV) X gene, and to further study the difference of HBV X protein (HBx) at varied expression levels in apoptosis regulation of hepatocellular carcinoma cells. The recombinant plasmid rPX with HBV enhancer 1 (Enh1), X gene promoter, X gene and polyA tail were constructed, respectively. PATIENTS AND METHODS: HepG2 cells were transiently transfected with the recombinant plasmids and control vector pGEM®-7Zf (+) by virtue of Fugene®HD; reverse transcription PCR (RT-PCR) and Western blotting were applied to analyze the transcription and expression of HBV X gene as well as the difference in the expression level in multiple groups. The activity of the transfected cells in each group was detected by using the methyl thiazolyl tetrazolium (MTT) method for 6 consecutive days after transfection. A flow cytometer was utilized to measure the cell apoptosis rate. RESULTS: The RT-PCR results showed that messenger RNA expression of HBV X gene was detected in all HepG2 cells transfected by different recombinant plasmids, of which the relationships of the expression levels were rCX>rEX1 and rEX2> rPX (p<0.05). Only HepG2/rCX cells in each group of transfected cells showed HBx expression by Western blot. MTT method revealed that there were notable differences between HepG2/rCX, HepG2/rEX1, HepG2/rPX and HepG2/pGEM®-7Zf (+) (p<0.05). The apoptosis rates of HepG2/rCX, HepG2/rEX1 and HepG2/rPX were significantly higher than that of HepG2/pGEM®-7Zf (+) (p<0.05). CONCLUSIONS: HBx can promote cell apoptosis. Results of this research also indicate that there is a significant difference in the pro-apoptotic role of HBx when its expression is regulated by different promoters, and such a difference may be a part of the complex pathogenic mechanisms of HBV and hepatocellular carcinoma.

Direct alteration of erythrocyte membrane properties by 1-chloro-2,4-dinitrobenzene without oxidant challenge.

The electrophilic agent, 1-chloro-2,4-dinitrobenzene (CDNB), has been widely used as an intracellular glutathione-depleting agent. However, its possible effect on the functional integrity of cell membrane has largely been neglected. Incubation of human erythrocytes (RBC) with various concentrations of CDNB (0.5 to 5.0 mM) in potassium-free, phosphate buffered saline containing ouabain resulted in a drastic depletion of cellular glutathione as well as a dose-dependent increase in passive potassium leakage. Further, an osmotic gradient ektacytometry profile indicated that the deformability index (DI) of CDNB-treated RBC was substantially lower than the DI value of the control. Also, CDNB caused a dose-dependent increase in the rate of shear-induced fragmentation of resealed ghost prepared from treated, intact erythrocytes. These CDNB-induced changes were accompanied by stomatocytic transformations as evidenced by scanning electron micrographs. Additional study indicated that CDNB caused a dose-dependent decrease in thiol concentrations of RBC membrane. SDS-PAGE analysis of membrane proteins revealed new Coomassie blue stainable bands, most noticeable below band-7 (M.W. 20,000). The effects of CDNB on RBC deformability and membrane proteins were also investigated under an atmosphere without oxygen (under nitrogen) and similar effects were observed between that under room air and that under nitrogen. Taken together, these data strongly indicate that CDNB has an adverse effect on the RBC membrane integrity in addition to its ability to deplete intracellular glutathione, possibly through its interaction with membrane sulfhydryl groups.

Artemisinin (qinghaosu): the role of intracellular hemin in its mechanism of antimalarial action.

Artemisinin (qinghaosu), is a promising new antimalarial drug derived from an ancient Chinese herbal remedy. When [13-14C]artemisinin is added to cultures of Plasmodium falciparum, it is converted into a product with different solubility and chromatographic properties than the parent drug. Artemisinin reacts with hemin in aqueous solution to form an adduct with an apparent molecular weight of 914 which has identical chromatographic, solubility, and electrophoretic behavior to the parasite-derived product. The reaction between artemisinin and hemin, when carried out in the presence of red cell membranes, leads to the oxidation of protein thiols. Malarial parasites are rich in hemin; artemisinin's reactivity toward hemin may explain its selective toxicity to malarial parasites.