[Biosafety risk of laboratory-acquired infection and countermeasures based on human factors]

Biosafety of pathogenic microbiology laboratories generally highlights the use of protective equipment, procedures, and operating practices to protect personnel and the environment from potentially hazardous biological materials. Under the current complex situation where traditional and non-traditional biosafety issues coexist, laboratory-acquired infection (LAI) of pathogenic microorganisms may cause illness, disability and even death. Pathogenic microorganisms may also be carried to the surrounding environment, causing community infection, which should be taken seriously. Analysis of LAI cases helps to understand the causes of exposure and learn lessons from post-exposure prophylaxis to be prepared and even prevent problems before they happen. Human factors cause most LAIs, laboratory activities related to aerosolization, laboratory activities related to sharps materials, low ability of personnel performing the work, and deficiencies in laboratory facilities or management are the four main factors. This study focuses on the human factors that lead to LAI, combined with confirmed cases, discusses the biosafety risks of pathogenic microorganism laboratories, reviews the development and evolution of biosafety laboratories and the current protection measures for experimenters, and accordingly puts forward countermeasures and suggestions.

Electropolishing influence on biocompatibility of additively manufactured Ti-Nb-Ta-Zr: in vivo and in vitro

Balling defect of the additively manufactured titanium lattice implants easily leads to muscle tissue rejection, which might cause failure of implantation. Electropolishing is widely used in surface polishing of complex components and has potential to deal with the balling defect. However, a clad layer could be formed on the surface of titanium alloy after electropolishing, which may affect the biocompatibility of the metal implants. To manufacture lattice structured β-type Ti-Ni-Ta-Zr (TNTZ) for bio-medical applications, it is necessary to investigate the impact of electropolishing on material biocompatibility. In this study, animal experiments were conducted to investigate the in vivo biocompatibility of the as-printed TNTZ alloy with or without electropolishing; and proteomics technology was used to elaborate the results. The following conclusions were drawn: (a) a 30% oxalic acid electropolishing treatment was effective in solving balling defects, and ~21 nm amorphous clad layer would be formed on the surface of the material after polishing; (b) the electropolished TNTZ suggested decreased cell cytotoxicity and improved blood biocompatibility as compared to as-printed TNTZ; (c) the amorphous clad layer could make a barrier to prevent Ta and Zr ions from penetrating into the muscle tissue, and could form a good tissue regeneration at the implantation site during 4 weeks, indicating that the electropolished TNTZ has the potential as implants; and (d) the cells attached to the electropolished TNTZ showed higher antioxidant capacity but less proliferation than attached to as-printed TNTZ.

[Prognostic values of stromal tumor-infiltrating lymphocytes and lymphocyte-activation gene-3 in advanced gastric adenocarcinoma]

Objective: To analyze density of stromal tumor-infiltrating lymphocytes (sTIL) and expression of lymphocyte-activation gene-3 (LAG-3) protein in advanced gastric adenocarcinomas, and to investigate the correlation of sTIL and LAG-3 with the prognosis in patients with advanced gastric adenocarcinoma. Methods: The clinicopathological characteristics and follow-up data of 260 patients with advanced gastric adenocarcinoma were collected at Fujian Cancer Hospital, from January 2011 to December 2014. The percentage of sTILs was reported semi-quantitatively using histological section evaluation, the LAG-3 protein was detected using immunohistochemistry, and the expression was correlated with the clinicopathological features and patient outcomes. Results: Among the 260 cases, high density of sTIL was detected in 173 cases (66.5%) while LAG-3 high expression was observed in 160 cases (61.5%). These cases were divided into four groups. Group Ⅰ: 48 cases (18.5%) were sTIL low/LAG-3 low; group Ⅱ: 52 cases (20.0%) were sTIL high/LAG-3 low; group Ⅲ: 39 cases (15.0%) were sTIL low/LAG-3 high; group Ⅳ: 121 cases (46.5%) were sTIL high/LAG-3 high. Kaplan-Meier survival analyses showed that patient prognoses were related to age, tumor size, tumor location, Lauren classification, perineural invasion, vascular invasion, TNM staging, postoperative adjuvant chemotherapy and molecular classification (P<0.05). Meanwhile, higher densities of sTIL and higher expression of LAG-3 were associated with better prognosis. Multivariate survival analysis showed age, tumor size, Lauren classification and postoperative adjuvant chemotherapy were independent prognostic factors for patient survival. The results showed a poor prognosis in low-sTIL/low-LAG-3 patients. Conclusions: Compared with low density of sTIL and low expression of LAG-3, high density of sTIL and high expression of LAG-3 are associated with better outcomes in patients with advanced gastric adenocarcinoma, respectively. Combined detecton of sTIL and LAG-3 may be more useful in gastric cancer than using either alone. Age, tumor size, Lauren classification and postoperative adjuvant chemotherapy are independent prognostic factors for patients with advanced gastric adenocarcinoma.

GSDME Is Related to Prognosis and Response to Chemotherapy in Oral Cancer

Gasdermin E (GSDME), as the major executive protein of pyroptosis, has been considered to be linked to antitumor immunity in recent years. However, the role of GSDME in oral squamous cell carcinoma (OSCC) remains to be elucidated. Here, by using a human OSCC tissue microarray, human OSCC tissue, and Tgfbr1/Pten conditional knockout mice, we found that GSDME was strongly expressed in OSCC and that GSDME expression in primary tumors was higher than that in metastatic lymph nodes. In addition, GSDME expression in OSCC was positively related to better prognosis. Moreover, GSDME-mediated pyroptosis occurred upon stimulation with chemotherapy drugs, and functional knockdown of GSDME attenuated the cisplatin-induced antitumor effect. Consistent with these results, bioinformatic analysis indicated that GSDME expression was positively correlated with the sensitivity of a number of antitumor drugs approved by the US Food and Drug Administration. Inhibition of GSDME expression by small interfering RNA in SCC7 cells significantly increased the expression of the cancer stem cell markers, CD44 and ALDH1. Furthermore, multiplexed immunohistochemistry and flow cytometry indicated that the expression of GSDME positively correlated with tumor-infiltrating CD8⁺ T cells, granzyme B, and M1 phenotype macrophages. Collectively, these findings demonstrated that GSDME is a potential positive prognostic factor of OSCC, and GSDME-mediated pyroptosis induced by chemotherapy plays a role in antitumor response.

[Clinicopathological features of NTRK3 gene rearrangement papillary thyroid carcinoma]

Objective: To investigate the clinicopathological features and differential diagnosis of NTRK3 gene rearrangement thyroid papillary carcinoma (PTC). Methods: The PTC cases without BRAF V600E mutation were collected at Fujian Provincial Hospital South Branch from January 2015 to January 2020. The cases of NTRK3 gene rearrangement PTC were examined using immunohistochemistry and fluorescence in situ hybridization (FISH). The clinical data, histopathological characteristics, immunohistochemical features and molecular pathological changes were retrospectively analyzed. Data from the TCGA PTC dataset and the literature were also studied. Results: A total of 3 PTC cases harboring NTRK3 gene rearrangement were confirmed. All the patients were female, aged from 26,49,34 years. Histologically, two of them demonstrated a multinodular growth pattern. Only one case showed prominent follicular growth pattern; the other two tumors showed a mixture of follicular, papillary and solid growth patterns. All tumors showed a typical PTC nuclear manifestation, with some nuclear pleomorphism, vacuolated foci and oncocytic features. The characteristic formation of glomeruloid follicular foci was present in two cases which also showed psammoma bodies, and tumoral capsular or angiolymphatic invasion. The background thyroid parenchyma showed chronic lymphocytic thyroiditis. Mitotic rates were low, and no cases had any tumor necrosis. The pan-TRK and TTF1 testing was both positive in 3 cases, while S-100 and mammaglobin were both negative in them. FISH studies confirmed the NTRK3 gene rearrangement in all 3 cases. Studies on the TCGA datasets and literature revealed similar findings. Conclusions: NTRK3 gene rearrangement PTC is rare. It may be easily misdiagnosed due to the lack of histological and clinicopathological characteristics. Molecular studies such as pan-TRK immunostaining, FISH and even next-generation sequencing are needed to confirm the diagnosis. Immunohistochemistry of pan-TRK performed in the PTC cases without BRAF V600E mutation can be used as a good rapid-screening tool. With the emergence of pan-cancer tyrosine receptor kinase inhibitors, proper diagnosis of these tumors can help determine appropriate treatments and improve their outcomes.

[Study on the incidence of adult herpes zoster in Yichang city and its association with early-life famine exposure]

Based on Yichang health big data platform, 850 608 patients from September 2018 to September 2019 were included in this study. According to the date of birth, the participants were divided into early childhood famine exposure group, fetal famine exposure group and non-famine exposure group. The incidence of adult herpes zoster (HZ) in Yichang city was analyzed, and the correlation between early life famine exposure and adult HZ was analyzed. In 2019, the crude incidence rate of adult HZ in Yichang was 6.83‰. The crude incidence rate of adult HZ in females (7.26‰) was higher than that in males (6.40‰). Compared with the non-famine exposure group, fetal famine exposure was associated with the incidence of adult HZ (OR=1.21; 95%CI: 1.01-1.45, P=0.041). After stratification by sex, fetal famine exposure was only found to be associated with the onset of adult HZ in females (OR=1.28, 95%CI:1.02-1.61, P=0.034).

Effect of chromium methionine supplementation on lactation performance, hepatic respiratory rate and anti-oxidative capacity in early-lactating dairy cows

Chromium may regulate dairy cow metabolism; a chelated formation of chromium methionine (Cr-Met) is available to the feed industry. The objective of this study was to investigate the effect of Cr-Met supplementation on lactation performance, hepatic respiratory rate and anti-oxidative capacity in early-lactating Holstein dairy cows. 64 multiparous cows were assigned to 16 blocks based on parity and milk yield and then the four cows in a block were randomly allocated to four treatment groups with 0, 4, 8 or 16 g/d of Cr-Met per cow supplemented to a basal diet. Cows were moved from an open dry lot to a naturally ventilated tie stall barn 2 weeks before treatment to adapt to this facility, fed and milked at 0630, 1400, and 1930 h every day. The experiment lasted for 12 weeks. Milk yield and composition were recorded weekly. Dry matter intake was measured every 2 weeks for a total of six times throughout the trial. The plasma variables were measured in weeks 4, 8 and 12 of the experiment. Supplementation of Cr-Met did not affect DM intake of cows. As the supplementation of Cr-Met increased, yields of milk, fat, energy corrected milk (P < 0.01) and lactose (P = 0.01) increased in a linear manner. In terms of plasma variables, insulin concentration decreased in a linear manner with Cr-Met supplementation. As for variables relating to hepatic respiration rate, concentrations of pyruvate and NAD in the plasma were increased in quadratic manners, and lactic dehydrogenase activity was linearly increased as Cr-Met feeding levels increased. Moreover, plasma glutathione peroxidase and superoxide dismutase activity were increased in a linear manner. In conclusion, our study suggested that Cr-Met supplementation improved lactation performance of early-lactating dairy cows through enhancing antioxidant capacity and hepatic cellular respiration.

[Efficacy of olaparib combined with pembrolizumab in second-line treatment for extensive-stage small cell lung cancer]

Objective: To compare the efficacy and safety of olaparib in combination with pembrolizumab with pembrolizumab alone in second-line treatment for patients with extensive stage-small cell lung cancer (ES-SCLC) whose ages ranged from 40 to 80 years. Methods: From March 2017 to October 2019, 21 patients with progressed or relapsed small cell lung cancer after standard first line treatment were enrolled in this study. The olaparib/pembrolizumab group (n=11) was treated by olaparib 300mg twice per day combined with pembrolizumab 200mg once every 3 weeks, while pembrolizumab group was treated by pembrolizumab alone. Results: The objective response rate (ORR) of olaparib/pembrolizumab group and pembrolizumab group were 45.5% and 10.0%, respectively (P=0.149), and the disease control rate (DCR) were 81.8% and 70.0% (P=0.635). The median progression-free survival (PFS) were 5.93 months and 3.53 months (P=0.036), the median overall survival (OS) were 10.43 months and 8.43 months (P=0.063). The adverse reaction incidences of all grades were 90.9% and 70.0% (P=0.311), and the incidences of grade Ⅲ-Ⅴ including myelosuppression were 36.4% and 10.0% (P=0.311), gastrointestinal reaction were 9.1% and 10.0%, (P=1.000) and other immune-related adverse events were 18.2% and 30.0% (P=1.000). Further analysis showed the metastatic number (P=0.006), platinum sensitivity (P=0.036) and LDH level (P=0.022) significantly affected the ORR of olaparib/pembrolizumab therapy. Conclusion: Our preliminary study indicates that olaparib combined with pembrolizumab is an efficient and safe second-line treatment therapy for patients with ES-SCLC.

[Cyto-inactivation instantly induced by microwave ablation on thyroid nodules]

Objective: To explore the effect of microwave ablation on thyroid nodules cell activity by the reaction of key enzyme of cell activation. Methods: From November 2017 to February 2018, 104 patients with 120 thyroid nodules underwent ultrasound-guided microwave ablation at Super-minimally Invasive Medicals, Shanghai International Medical Center, aged 14-55 years, 42 males and 62 females.Twice core needle biopsy were performed before and after thermal ablation.The specimen were using hematoxylin and eosin (HE) staining and enzyme histochemical staining with include succinate dehydrogenase (SDH) and nicotinamide adeninedinucleotide phosphate diaphorase (NADPH-d), respectively, and observe under microscope. Results: Enzyme histochemical staining showed that the positive rate of SDH and NADPH-d in the marginal region and transitional region were 100% before ablation, and were 0% immediately after ablation.The positive rate of SDH and NADPH-d histochemical staining in the same area before and immediately after ablation was statistically significant (P<0.05). Shortly after microwave ablation, the tissue structure and cell morphology showed no obvious alteration in HE stained sections, but in sections with enzyme histochemical staining, the activity of SDH and NADPH-d in ablated tissue disappeared.The accuracy rate of pathologic diagnosis was 100% after ablation. Conclusions: SDH and NADPH-d enzyme activity may be better in evaluating the short-term efficacy of microwave ablation of thyroid nodules than HE staining.

Evidence for Weyl fermions in a canonical heavy-fermion semimetal YbPtBi

The manifestation of Weyl fermions in strongly correlated electron systems is of particular interest. We report evidence for Weyl fermions in the heavy fermion semimetal YbPtBi from electronic structure calculations, angle-resolved photoemission spectroscopy, magnetotransport and calorimetric measurements. At elevated temperatures where 4f-electrons are localized, there are triply degenerate points, yielding Weyl nodes in applied magnetic fields. These are revealed by a contribution from the chiral anomaly in the magnetotransport, which at low temperatures becomes negligible due to the influence of electronic correlations. Instead, Weyl fermions are inferred from the topological Hall effect, which provides evidence for a Berry curvature, and a cubic temperature dependence of the specific heat, as expected from the linear dispersion near the Weyl nodes. The results suggest that YbPtBi is a Weyl heavy fermion semimetal, where the Kondo interaction renormalizes the bands hosting Weyl points. These findings open up an opportunity to explore the interplay between topology and strong electronic correlations.

[The diagnostic value of low dose of dual-source CT venography for deep venous thrombosis]

Objective: To investigate the diagnostic value of low dose of dual-source CT venography examination for DVT (deep venous thrombosis). Methods: A total of 60 patients from Nanjing First Hospital with suspected DVT underwent indirect low dose CTV examination and treatment of DSA from January to December, 2017, and recording the radiation dose for CTV.DSA as the gold standard, calculate the sensitivity, specificity of CTV, kappa consistency test was used to exam the results of CTV and DSA.McNemar test was used to check statistical difference between two examinations. Results: A total of 60 patients, 780 blood vessels took CTV examinations, 326 were positive; 420 blood vessels took DSA examinations, 332 were positive.DSA as the gold standard, the sensitivity, specificity, of DVT detection by CTV were 96.2% and 92.6%, kappa=0.860, P<0.05, and the result of McNemar test was P=0.263. Conclusion: Low dose of dual-source indirect CTV examination for DVT can not only reduce radiation dose for the patients, but also has a high clinical value in the diagnosis of DVT.

[An investigation of mental health in migrant workers in an enterprise]

Objective: To investigate the mental health status in migrant workers in a labor-intensive enterprise and related influencing factors. Methods: Typical sampling was used to perform an investigation in 910 migrant workers in a large foreign-funded labor-intensive enterprise in Shenzhen, China. All the respondents gave informed consent and completed the questionnaire independently and anonymously. The self-reported mental health status was evaluated using the Beck Anxiety Inventory, Beck Depression Inventory, and General Health Questionnaire. Results: Of all the migrant workers in this enterprise, 7.2% had a positive self-reported anxiety symptom, 25.4% had a moderate or severe self-reported depression symptom, and 76.4% had a poor self-reported general health status. Age had significant influence on the self-reported depression symptom (χ²=21.968, P<0.05) ; age did not have significant influence on the self-reported anxiety and general health status (χ²=6.616、12.498, both P>0.05) . The knowledge of occupational hazards had significant influence on mental health status (χ²_Depression=47.289, χ²_{General health}=21.087, both P<0.05) . The feeling of work had significant influence on self-reported depression and general health status (χ²_Depression=52.406, χ²_{General health}=17.327, both P<0.05) . Attention to self mental health had significant influence on self-reported depression (χ²=17.714, P<0.05) , and whether the person wanted to learn the knowledge of mental health had significant influence on self-reported anxiety (χ²= 6.145, P<0.05) . Conclusion: The self-reported mental health status in migrant workers is poor and is associated with age, worry about exposure to occupational hazard factors, emphasis on mental health knowledge, and a focus on personal mental health. Therefore, targeted occupational health education and occupational mental health education should be strengthened.

[Metabolic syndrome and its influencing factors in professional automobile drivers in a company]

OBJECTIVE

To investigate the prevalence of metabolic syndrome (MS)in 259 professional automobile drivers, and to put forward targeted suggestions on protection.

METHODS

In October 2014, 114 male bus drivers and 145 male taxi drivers in a transportation service company were enrolled as investigation group, and 121 non-operating male staff were enrolled as control group. Physical examination and a questionnaire survey were conducted for both groups, and the results were analyzed.

RESULTS

The bus drivers and taxi drivers had significantly higher prevalence rates of MS than the nonoperating staff(17.5%/13.1% vs 3.3%, P<0.05). The results of univariate logistic analysis showed that smoking(OR=2.58, 95%CI 1.14~5.88), exercise (OR=0.21, 95% CI 0.10~0.43), meal time (OR=0.27, 95% CI 0.13~0.59), and a family history of chronic diseases (OR=2.26, 95% CI 1.13~4.50)were associated with MS, and each independent variable showed significant differences between groups (P<0.05). Multivariate logistic regression analysis showed that with age remaining the same, smoking was the risk factor for MS in professional automobile drivers (OR=5.25, 95%CI 2.00~13.80), and meal time (20~40 min)(OR= 0.20, 95%CI 0.09~0.44)and exercise (OR=0.13, 95% CI 0.06~0.30)were protective factors against MS.

CONCLUSION

Professional automobile drivers have a higher prevalence rate of MS than non-operating staff, which should be taken seriously by working personnel.

[Association between efficacy and molecular subtypes in breast cancer patients receiving neoadjuvant chemotherapy]

OBJECTIVE

To investigate the association between pathological complete response (pCR), clinicopathological characteristics and clinical outcomes in breast cancer patients receiving neoadjuvant chemotherapy.

METHODS

Medical records of 221 patients who underwent neoadjuvant chemotherapy for breast cancer between January 2006 and December 2008 were retrospectively reviewed. Their clinicopathological features, response to neoadjuvant chemotherapy, survivals and prognostic factors were then analyzed.

RESULTS

The total pCR rate was 11.3% (25/221). The rate of pCR was 0%(0/12), 5.7%(6/106), 7.4%(2/27) and 16.9%(11/65) in the luminal A, luminal B, HER-2, and Basal-like subtypes, respectively. Statistically significant association was found between the pCR rate and the molecular substypes of breast cancer(P<0.05). The median 5-year disease free survival and the 5-year overall survival were 72 months and 79 months. The 5-year disease free survival rate and 5-year overall survival rate were 61.1% and 71.9% in all the 221 patients. The 5-year disease free survival rates of pCR and non-pCR patients were 84.0% and 58.2%, and the 5-year overall survival rates of pCR and non-pCR patients were 96.0% and 68.9%, respectively(P<0.05 for all). The multivariate survival analysis showed that clinical and pathological node stage and pCR are independent prognostic factors for the 5-year disease-free survival and 5-year total survival in patients with neoadjuvant chemotherapy (P<0.05 for both).

CONCLUSIONS

pCR is more frequently observed in HER-2 and basal-like breast cancer subtypes compared with the luminal breast cancer subtype. The status of clinical and pathological node status and pCR are independent prognostic factors in patients treated with neoadjuvant chemotherapy.

EBV-encoded LMP-1 sensitizes nasopharyngeal carcinoma cells to genotoxic drugs by down-regulating Cabin1 expression

The oncogenic latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) is involved in the pathogenesis of human nasopharyngeal carcinoma (NPC) and lymphoma. We and other authors have shown earlier that LMP1 induces apoptosis and inhibits xenograft tumor growth in mice, but the mechanism underlying these processes has not been investigated so far. In the present study, we show that knockdown of LMP1 renders the EBV-positive NPC cell line CG-1 resistant to various genotoxic drugs (cisplatin, etoposide, and adriamycin). LMP1 inhibits the expression of Cabin1, a Ca(2+) regulated protein shown earlier to inhibit calcineurin. Knockdown of calcineurin binding protein (Cabin1) with small hairpin RNA sensitizes CG-1 cells to genotoxic drugs. In contrast, LMP1 overexpression reduces Cabin1 level and renders both CG-1 cells and EBV-negative NPC cell lines sensitive to cisplatin. The c-Jun-N-terminal kinase (JNK) and ERK pathways are required for LMP1-induced suppression of Cabin1 at the transcriptional level. Chromatin immunoprecipitation assays further confirm that the JNK-activated transcription factor AP-1 mediates the LMP1-induced down-regulation of Cabin1 gene expression. LMP1 knockdown also increases the resistance of xenograph tumors to cisplatin in mice, therefore confirming the relevance of our findings in vivo. This study reveals the molecular mechanism underlying the pro-apoptotic activity of LMP1 during cisplatin-based NPC chemotherapy.

Silencing of the SNARE protein NAPA sensitizes cancer cells to cisplatin by inducing ERK1/2 signaling, synoviolin ubiquitination and p53 accumulation

We found earlier that NAPA represents an anti-apoptotic protein that promotes resistance to cisplatin in cancer cells by inducing the degradation of the tumor suppressor p53. In the present study, we investigated the cellular mechanism underlying the degradation of p53 by NAPA. Knockdown of NAPA using short-hairpin RNA was shown to induce p53 accumulation and to sensitize HEK293 cells to cisplatin. On the other hand, this sensitization effect was not found in H1299 lung carcinoma cells which lack p53. Expression of exogenous p53 in H1299 cells was increased following knockdown of NAPA and these cells showed increased sensitivity to cisplatin-induced apoptosis. Notably, knockdown of NAPA induced the ubiquitination and degradation of the E3 ubiquitin ligase synoviolin and the accumulation of p53 in unstressed HEK293 cells. Conversely, NAPA overexpression decreased the ubiquitination and degradation of synoviolin, and reduced p53 protein level. Knockdown of NAPA disrupted the interaction between synoviolin and proteins that form the endoplasmic reticulum-associated degradation (ERAD) complex and in turn decreased the ability of this complex to ubiquitinate p53. In addition, knockdown of NAPA induced the activation of the MAPK kinases ERK, JNK and p38, but only inhibition of ERK reduced synoviolin ubiquitination and p53 accumulation. These results indicate that NAPA promotes resistance to cisplatin through synoviolin and the ERAD complex which together induce the degradation of p53 and thus prevent apoptosis. Based on these findings, we propose that the combination of cisplatin and knockdown of NAPA represents a novel and attractive strategy to eradicate p53-sensitive cancer cells.

Knockdown of CITED2 using short-hairpin RNA sensitizes cancer cells to cisplatin through stabilization of p53 and enhancement of p53-dependent apoptosis

CITED2 is a transcriptional modulator which has been implicated in human oncogenesis. In the present study, we examined whether CITED2 is also involved in the resistance of cancer cells to the chemotherapeutic drug cisplatin. We first observed that knockdown of CITED2 using short-hairpin RNA sensitized non-tumorigenic HEK293 cells to cisplatin. Sensitization to cisplatin following knockdown of CITED2 was also observed in cervical carcinoma HeLa cells and in cisplatin-resistant HeLa cells, thereby showing that acquired cisplatin resistance could be reversed by CITED2 knockdown. This sensitization response was dependent on the status of p53 since efficient sensitization was observed in p53-positive hepatocellular carcinoma (HCC) Sk-Hep-1 cells, whereas a negligible response was produced in the two p53-defective cell lines HCC Mahlavu and lung cancer H1299. In contrast, overexpression of CITED2 decreased sensitivity of HEK293 cells to cisplatin, while moderate resistance was produced in HeLa cells. Overexpression of CITED2 also decreased sensitivity to cisplatin in p53-defective H1299 cells when exogenous p53 expression was re-introduced. We observed that knockdown of CITED2-induced CBP/p300-mediated p53 acetylation (Lys373) in HEK293 cells, thereby leading to a decrease of p53 ubiquitination and subsequent accumulation of the p53 protein. Notably, the effects of CITED2 knockdown on p53 accumulation and the increase of p53's target Bax were more pronounced after treatment with cisplatin. Based on these results, we propose that a combination of cisplatin and CITED2 shRNA may represent an effective treatment against p53-sensitive cancer cells.

Identification and functional analysis of genes which confer resistance to cisplatin in tumor cells

The efficacy of cisplatin during cancer chemotherapy is often impaired by the emergence of cancer cells which become resistant to chemotherapeutic agents. While various mechanisms have been proposed to explain resistance to cisplatin, the genes involved in this process still remain unclear. By using DNA microarrays, we performed a genome-wide analysis of cisplatin-resistant HeLa cells in order to identify genes involved in resistance. We identified nine genes (NAPA, CITED2, CABIN1, ADM, HIST1H1A, EHD1, MARK2, PTPN21, and MVD), which were consistently upregulated in two cisplatin-resistant HeLa cell lines. The upregulated genes, here referred to as cisplatin resistance genes (CPR), were further analyzed for their ability to modify the response of HEK293 cells to cisplatin. Short-hairpin RNA (shRNA) knockdown of CPR genes, individually or in combination, was shown to sensitize HEK293 cells to cisplatin, but not to vincristine or taxol, suggesting that CPR genes may be involved specifically in cisplatin resistance. Among the treatments performed, shRNA knockdown of NAPA was the most efficient treatment able to sensitize cells to cisplatin. Furthermore, shRNA knockdown of a single CPR gene was sufficient to partially reverse acquired cisplatin resistance in HeLa cells. Sensitization to cisplatin following knockdown of CPR genes was also observed in the tumorigenic cell lines Sk-ov-3, H1155, and CG-1. Based on these results, we propose that the CPR genes identified here may represent potential candidates for novel target therapies aimed at preventing resistance to cisplatin during chemotherapy.

Induction of G2/M phase arrest and apoptosis by a novel enediyne derivative, THDB, in chronic myeloid leukemia (HL-60) cells

(Z)-2-(6-(Thieanisyl-2-yl)hexa-3-en-1,5-diynyl)benzenamine (THDB), an enediyne compound, was identified in our laboratory as a novel antineoplastic agent with broad spectrum of antitumor activities against many human cancer cells. THDB was found to inhibit the growth of HL-60 cells in a time-and dose-dependent manner. Cell cycle analysis showed G2/M phase arrest in HL-60 cells following 48 h exposure to THDB. Analysis of the cell cycle regulatory proteins demonstrated that THDB did not change the steady-state levels of cyclin B1, cyclin E, Cdk1 and Cdc25C, but decreased the protein levels of Cdk2 and cyclin A. THDB also caused a marked increase in apoptosis, as characterized by DNA fragmentation (DNA ladder and sub G1 formation), and poly (ADP-ribose) polymerase (PARP) cleavage, which was associated with activation of caspase-3, caspase-8 and caspase-9. Moreover, the THDB-induced apoptosis was significantly attenuated in the presence of specific inhibitors of caspase-3, -8 and -9. These molecular alterations provide an insight into THDB-caused growth inhibition, G2/M arrest and apoptotic death of HL-60 cells.

Cardiotoxin III induces apoptosis in K562 cells through a mitochondrial-mediated pathway

1. Cardiotoxin (CTX) III is a basic polypeptide with 60 amino acid residues isolated from Naja naja atra venom. This is the first report on the mechanism of the anticancer effect of CTX III on human leukaemia K562 cells. 2. Cardiotoxin III was found to inhibit the growth of K562 cells in a time- and dose-dependent manner, with an IC(50) value of 1.7 mug/mL, and displayed several features of apoptosis, including apoptotic body formation, an increase in the sub-G(1) population, DNA fragmentation and poly (ADP-ribose) polymerase (PARP) cleavage. 3. Investigation of the mechanism of CTX III-induced apoptosis revealed that treatment of K562 cells with CTX III resulted in the loss of mitochondrial membrane potential, cytochrome c release from mitochondria into the cytosol and activation of caspase-9 and caspase-3 and the subsequent cleavage of the caspase-3 substrate PARP; however, CTX III did not generate reactive oxygen species (ROS). 4. Taken together, the results indicate that CTX III induces apoptosis in K562 cells through an ROS-independent mitochondrial dysfunction pathway.

Induction of G2/M phase arrest and apoptosis by a novel enediyne derivative, THDA, in chronic myeloid leukemia (K562) cells

We studied the effect of 2-(6-(2-thieanisyl)-3(Z)-hexen-1,5-diynyl)aniline(THDA), a newly developed anti-cancer agent, on cell proliferation, cell cycle progression, and induction of apoptosis in K562 cells. THDA was found to inhibit the growth of K562 cells in a time-and dose-dependent manner. Cell cycle analysis showed G2/M phase arrest and apoptosis in K562 cells following 24 h exposure to THDA. During the G2/M arrest, cyclin-dependent kinase inhibitors (CDKIs), p21 and p27 were increased in a time-dependent manner. Analysis of the cell cycle regulatory proteins demonstrated that THDA did not change the steady-state levels of cyclin B1, cyclin D3 and Cdc25C, but decreased the protein levels of Cdk1, Cdk2 and cyclin A. THDA also caused a marked increase in apoptosis, which was associated with activation of caspase-3 and proteolytic cleavage of poly (ADP-ribose) polymerase. These molecular alterations provide an insight into THDA-caused growth inhibition, G2/M arrest and apoptotic death of K562 cells.

The syntheses and in vivo biodistribution of novel boronated unnatural amino acids

A series of boronated, unnatural amino acids were prepared and their biodistribution determined in melanoma bearing mice. The unnatural amino acids were prepared utilizing recently developed borylation. The majority of the syntheses utilize metal catalyzed additions of diboron agents to unsaturated carbonyl compounds. Biodistribution studies in mice bearing melanoma tumors indicated that all the boronated amino acids were taken up by the melanoma tumors. The data for the cyclic five-membered ring analogue, 1-amino-3-boronocyclopentanecarboxylic acid, was most striking, exhibiting a nearly 22:1 ratio of boron concentration for tumor to brain at the 2 h time point, dropping to 7.3 after 6 h. The tumor to blood and tumor to skin ratios were also quite high. It is important to note that all of the amino acids were synthesized as racemic and diastereomeric mixtures. Thus there is a high probability that a single enantiomer of 1-amino-3-boronocyclopentanecarboxylic acid might exhibit far higher selectivity.

[Inhibition of ATP-activated current by met-Enk in isolated DRG neurons of the rat]

The present study aimed to explore modulation of ATP-activated currents (I(ATP)) by met-Enk in rat DRG neurons. I(ATP) was recorded using the whole-cell patch clamp technique. The majority of the neurons examined responded to ATP (90.0 percent;, 45/50) with inward currents. In the 45 ATP sensitive neurons three kinds of responses to application of met-Enk were distinguished: (l) inward currents (29/45), (2) outward currents (9/45), and (3) no effect (7/45). Pretreatment with met-Enk (10(-9)~10(-5) mol/L) suppressed I(ATP) (10(-4) mol/L) in 29 neurons responding to met-Enk with inward currents. The inhibition by met-Enk of I(ATP) could be blocked by naloxone (10(-7) mol/L) in a concentration-dependent manner. Met-Enk of 10(-9), 10(-8), 10(-7), 10(-6) and 10(-5) mol/L suppressed I(ATP) by l3.2+/-5.4 percent; (n=5); 39.2+/-8.6 percent; (n=8), 54.l+/-8.6 percent; (n=8),43.3+/-7.9 percent; (n=7) and 43.l+/-7.9 percent; (n=7) (mean+/-MSE), respectively. A comparison of concentration - response relations of ATP with and without preapplication of met-Enk indicated that after pretreatment with met-Enk (10(-7) mol/L) the curve shifted downward markedly with a decrease of 25 percent; of the maximum value of I(ATP) and unchanged K(d) value. The suppression of I(ATP) by met-Enk was reversed as evidenced by intracellular dialysis of H-9 by using the repatch technique. Taken together, it is suggested that the inhibition by met-Enk of I(ATP) is caused by activation of opiate receptor, which eventually results in phosphorylation of ATP receptor, mediated by modulation of G protein coupling and intracellular signal transduction.

Comparison of the viscoelastic properties of normal hepatocytes and hepatocellular carcinoma cells under cytoskeletal perturbation

The viscoelastic properties of both hepatocytes and hepatocellular carcinoma (HCC) cells were measured by means of a micropipette aspiration technique. Experimental results were analyzed with a three-element standard linear solid model, in which an elastic element, K1, is in parallel with a Maxwell element composed of another elastic element, K2, in series with a viscous element, mu. Further, we investigated the relevance of viscoelastic properties of these two types of cells to the cytoskeleton structures by treating cells with three cytoskeletal perturbing agents, namely cytochalasin D (CD), colchicine (Col) and vinblastine (VBL). The results showed that the elastic coefficients, but not viscous coefficient of HCC cells (K1 = 103.6 +/- 12.6 N m-2, K2 = 42.5 +/- 10.4 N m-2, mu = 4.5 +/- 1.9 Pa s, n = 30), were significantly higher than the corresponding values for hepatocytes (K1 = 87.5 +/- 12.1 N m-2, K2 = 33.3 +/- 10.3 N m-2, mu = 5.9 +/- 3.0 Pa s, n = 24). Upon treatment with CD, the viscoelastic coefficients of both hepatocytes and HCC cells decreased uniformly, with magnitudes for the decrease in elastic coefficients of HCC cells (K1: 68.7 to 81.7 N m-2, 66.3 to 78.9%; K2: 34.5 to 37.1 N m-2, 81.2 to 87.3%) larger than those for normal hepatocytes (K1: 42.6 to 49.8 N m-2, 48.7 to 56.9%; K2: 17.2 to 20.4 N m-2, 51.7 to 61.3%). There was a smaller decrease in the viscous coefficient of HCC cells (2.0 to 3.4 Pa s, 44.4 to 75.6%) than that for hepatocytes (3.0 to 3.9 Pa s, 50.8 to 66.1%). Upon treatment with Col and VBL, the elastic coefficients of hepatocytes generally increased or tended to increase while those of HCC cells decreased. The differences in either the pattern or the magnitude of the effect of cytoskeletal perturbing agent on the viscoelastic properties between HCC cells and hepatocytes might possibly reflect differences in the state of the cytoskeleton structure and function, or in the cells' sensitivity to perturbing agent treatment between these two types of cells. Changes in the viscoelastic properties of cancer cells might well affect tumor cell invasion and metastasis as well as interactions between tumor cells and their micro-mechanical environments.

[Studies on non-anthraquinones in Rheum officinale Baill]

OBJECTIVE

To investigate the non-anthraquinones from the root and rootstock of Rheum officinale.

METHOD

The chemical constituents were obtained from the 85% alcohol extract of the radix and rhizoma of R. officinale by column chromatography and identified by spectroscopic analysis.

RESULT

Ten non-anthraquinones were obtained, of which eight were identified by spectroscopic analysis as rheosmine, daucosterol, d-catechin, 6-cinnamoylisolindleyin, (-)-epicatechin-3-O-gallate, resveratrol-4'-O-beta-D-(6"-O-galloyl)-glucopyranoside, gallic acid, D-sorbitol.

CONCLUSION

Compounds rheosmine and D-sorbitol were obtained from the genus Rheum for the first time.

The effect of superoxide dismutase on the recovery of human bone marrow hemopoietic stem cells stored at 4 degreesC

The effect of superoxide dismutase (SOD) on the recovery of human hemopoietic stem cells stored at 4 degreesC has been studied. Human bone marrow cells from cancer patients without hemopoietic diseases were stored at 4 degreesC for 1-7 days in RPMI 1640 medium containing 10% human AB serum with or without 6 U/ml of SOD. The recovery of colony-forming units of the following types were counted: granulocyte and macrophage type; megakaryocyte type; mixed granulocyte, erythrocyte, megakaryocyte, and macrophage type; and burst-forming units of erythrocytic type. The SOD groups recovered, respectively, 5.6, 5.3, 4.6, and 4.4 times as many colonies as the control group. This study demonstrates that the addition of SOD to hypothermic storage media may increase the recovery of hemopoietic stem cells.

[In vitro stimulation of HTC hepatoma cell growth by recombinant human augmenter of liver regeneration (ALR)]

It was demonstrated that biologically active ALR could be expressed from its cDNA in transient expression experiments in cos-7 cells. The results showed that the cytosolic fraction from the transfected cells with constructed plasmids DNA stimulated of DNA synthesis of in vitro HTC cells in a dose dependent manner. This finding suggests that the HTC hepatoma cell line may be used as a target for bioassay of human ALR in vitro.

[Increase in the level of augmenter of liver regeneration mRNA in the rat regenerating liver after partial hepatectomy]

Augmenter of liver regeneration (ALR) is a novel hepatic stimulator. After 70% of the rat liver was removed, ALR-like activity in the remnant liver began to increase within 24 h. In parallel with the activity, the ALR mRNA level in the remnant liver increased 12 h after the operation and reached a maximum in 24 h. These findings indicate that the liver itself produces ALR, which may be a hepatotropic factor acting as a trigger for liver regeneration.

[Studies of a 35 KDa substance from human fetal liver on the regulation of hematopoiesis]

About 30%-40% of hematopoietic stem cells in human fetal liver of 3-5 months are in S phase of cell cycle, much higher than the ratio of 10% of that in adult bone marrow. The existance of highly active hematopoietic stem cell proliferation stimulators is probably its molecular basis. CFU-S "suicide rate" in rats was adopted to detect the effective substance. Through several steps of separation, we obtained a relatively purified substance of 35 kDa, termed it as FLS-4. CD 34 positive cord blood cells were sorted and assayed for their response to FLS-4 in 3H-TdR incorporation assay. The response to FLS-4 alone was approximately 1 times the background response seen with no factor added. In combination with IL-6 and IL-3 produced response that was 2.9 and 6.5 fold respectively greater than that observed with no factor added, but was weakly in comparison with the effects of SCF. In combination with GM-CSF or IL-3, FLS-4 can stimulate the formation of blast-colonies. The results indicate that the FLS-4 is very likely to be a novel hematopoietic stem cell proliferation stimulator. In physical or biological characteristics, it exhibited a unique character different from IL-3, IL-6, GM-CSF, SCF or FLT3 ligand those are known to have hematopoietic stem cell proliferation stimulating activity. During the period of active hematopoiesis in fetal liver, FLS-4 might be the candidate in triggering hematopoietic stem cells from resting G0 to S phase.

[Studies on the isolation, structure identification and biological function of two tumor cell suppressors of human fetal liver origin]

Our previous work showed the existence of low molecular weight tumor suppressors in human fetal tissues. In this paper, two tumor cell suppressors were isolated and purified from methanol extract of human fetal liver by C18 reversed-phase medium pressure chromatography, gel filtration on Sephadex LH-20, and high-performance liquid chromatography, directed by suppression of growth of HL-60 cells. The structures of the suppressors were identified to be 7-ketocholesterol and 7-beta-hydroxycholesterol. Under the condition of in vitro agar plate culture, 7-ketocholesterol and 7-beta-hydroxycholesterol showed preferentially inhibitory effects on the growth of both human and murine leukemic cell lines including human HL-60 and murine S-180 cells, but less effective on the growth of normal human and murine bone marrow granulocyte-macrophage progenitors (CFU-GM).

[Studies on characteristics of proliferation and differentiation of hematopoietic stem cells in mice]

By using Y chromosome specific sex-determining region (Sry) as a new cytogenetic marker and PCR technique, the characteristics of proliferation and differentiation of hematopoietic stem cells in mice were studied. Bone marrow cells from male mice were injected into lethally-irradiated female mice, PCR results indicated that all of the CFU-S were originated from donor. It was found that CFU-S was able to proliferate and differentiate into various hematopoietic cells in vivo during its transplantation. Whereas the fibroblasts within donor CFU-S and the fibroblasts from bone marrow in recipient mouse reestablished by donor CFU-S were shown to be originated from the recipient. The above data demonstrated that CFC-S from bone marrow in mice possessed the characteristics of hematopoietic stem cells but was not prone to differentiate into fibroblasts.

[The effect of GM-CSF/IL-3 on the grafting efficiency of CD34+ hemopoietic progenitor cells from umbilical cord blood]

CD34+ cells were isolated from human umbilical cord blood by using a high-gradient magnetic cell sorting system with anti-CD34 monoclonal antibody coated with microbeads, and then inoculated onto a pre-formed irradiated bone marrow stroma to evaluate the grafting efficiency of CD34+ cells with rhGM-CSF or IL-3, alone or in combination. The results showed that only 36% CD34+ cells in the control, and 68 - 89.6% in the groups with growth factors treatment seeded to the stroma. A short incubation of CD34+ cells with growth factors could rapidly reconstitute a long-term hemopoiesis in the long-term liquid culture system. This demonstrates that a brief treatment of CD34+ cells with GM-CSF or IL-3 can improve the grafting efficiency of transplanted umbilical cord blood cells.

[A method of measuring iris radius by computerized image analysis]

A new method of measuring the iris contour has been set up with a personal computer. The model of a parabolic curve, an approximate mimic iris contour curve, was traced to define the profile contour of the iris from a photograph. A radius measured from the apex of the curvature of the parabola, named iris radius (IR), was calculated by a computer to describe the degree of the curvature of the iris contour. The iris radius of 93 eyes of 68 cases with early pupillary block primary angle closure glaucoma were measured by this method. The results show that the mean iris radius of cases with glaucoma is shorter than that of the normal age matched controls (53 cases 106 eyes) and there is statistical significant difference (P < 0.01). This method of measurement can be an effective method to further study the early diagnosis and pathogenic mechanism of the pupillary block angle closure glaucoma.

Effect of electric field on erythrocyte sedimentation rate. IV. Volume fraction dependence of human red cells in plasma

We measured the volume fraction dependence of erythrocyte sedimentation for human red cells in autologous plasma while the volume fraction, Hct, ranges from 0.220 to 0.650. A modified electrophoretic instrument was employed to investigate the electric effect of an upward DC field on erythrocyte sedimentation at a constant source supply of Vs = 60.0 +/- 0.5 V. The sedimentation curves all coincided well with the sigmoidal type equation, l = lmax/¿l + (t50/t)n¿, at Vs = 0, or 60.0 V. Here, lmax is the length of plasma level, l, when the time, t, tends to infinity; t50 is the elapsed time when the plasma level falls to lmax/2, and n is a constant (n > 0). A non-linear least-squares method was employed to fit experimental data. It was found that lmax decreased and t50 increased with the increase of Hct, while n ranged from 1.53 to 3.95. The volume fraction dependence of sedimentation velocity, Vmax, defined as the maximum slope of the sedimentation curve, fits well with an exponential-type curve, both at Vs = 60.0 V and at Vs = 0 V: Vmax = Vs (1-Hct)exp(-BHct), where Vs is the velocity at infinite dilution and B is a phenomenological parameter. In the range of Hct = 0.220-0.650, Vs and B are 326.1 mm/hr and 4.30, respectively, at Vs = 60.0 V, while they are 130.4 mm/hr and 2.46, respectively, at Vs = 0 V.

[Preliminary study of cytochemistry on thin-white coating of tongue with deficiency-cold syndrome]

The method of qualitative and quantitative analysis and localization of cytochemistry were used to observe the epithelial cells of the thin-white coating of tongue from 25 patients with Deficiency Cold Syndrome (DCS) and 20 normal persons. Results showed that the level of intracellular DNA, PAS of the epithelial cells in the DCS group were markedly enhanced, while the activities of succinate dehydrogenase (SDH) and acid alpha-naphthyl acetate esterase (ANAE) were reduced significantly compared to normal group, P < 0.05, 0.001, 0.001, 0.01 respectively.