[Pre-operative prognostic nutritional index as a predictive factor for prognosis in non-metastatic renal cell carcinoma treated with surgery].

OBJECTIVE: To evaluate the implications of the prognostic nutrition index (PNI) in non-metastatic renal cell carcinoma (RCC) patients treated with surgery and to compare it with other hematological biomarkers, including neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and systemic immune inflammation index (SII). METHODS: A cohort of 328 non-metastatic RCC patients who received surgical treatment between 2010 and 2012 at Peking University First Hospital was analyzed retrospectively. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values of the hematological biomarkers. The Youden index was maximum for PNI was value of 47.3. So we divided the patients into two groups (PNI≤ 47. 3 and >47. 3) for further analysis. Categorical variables [age, gender, body mass index (BMI), surgery type, histological subtype, necrosis, pathological T stage and tumor grade] were compared using the Chi-square test and Student' s t test. The association of the biomarkers with overall survival (OS) and disease-free survival (DFS) was analyzed using Kaplan-Meier methods with log-rank test, followed by multivariate Cox proportional hazards model. RESULTS: According to the maximum Youden index of ROC curve, the best cut-off value of PNI is 47. 3. Low level of PNI was significantly associated with older age, lower BMI and higher tumor pathological T stage (P < 0.05). Kaplan-Meier univariate analysis showed that lower PNI was significantly correlated with poor OS and DFS (P < 0.05). In addition, older age, lower BMI, tumor necrosis, higher tumor pathological T stage and Fuhrman grade were significantly correlated with poor OS (P < 0.05). Cox multivariate analysis showed that among the four hematological indexes, only PNI was an independent factor significantly associated with OS, whether as a continuous variable (HR=0.9, 95%CI=0.828-0.978, P=0.013) or a classified variable (HR=2.397, 95%CI=1.061-5.418, P=0.036). CONCLUSION: Low PNI was a significant predictor for advanced pathological T stage, decreased OS, or DFS in non-metastatic RCC patients treated with surgery. In addition, PNI was superior to the other hematological biomar-kers as a useful tool for predicting prognosis of RCC in our study. It should be externally validated in future research before the PNI can be used widely as a predictor of RCC patients undergoing nephrectomy.

[Effect of overexpression of integrin ß2 on clinical prognosis in triple negative breast cancer].

Objective: To investigate the clinical significance of the expression of integrin ß2 (ITGB2) and tumor infiltrating dendritic cells CD80 and CD86 in triple negative breast cancer (TNBC). Methods: The expression levels of ITGB2 and MHC-1 in MDA-MB-231 cells and TNBC tissues were detected by Western bolt and RT-PCR, and the expressions of ITGB2, CD80 and CD86 in TNBC tissues were detected by immunohistochemistry. Results: 1.The expression level of ITGB2 in TNBC cell line (1.67±0.38) was higher than that in MCF-10A cell line (1.06±0.38), and the expression level of MHC-1 molecules in TNBC cell line (0.64±0.20) was lower than that in MCF-10A cell line (1.02±0.21). The difference was statistically significant (P=0.036 and 0.020, respectively). 2.The expression level of ITGB2 in TNBC tissues (1.55±0.47) was significantly higher than that in normal breast tissues (1.04±0.31). 3. Immunohistochemistry showed that the expression level of ITGB2 in TNBC tissues (3.31±2.29) was significantly higher than that in paracancerous tissues (1.20±1.19). Combined with clinicopathological data, it was suggested that the expression of ITGB2 was correlated with tumor stage (P=0.038), histological grade (P=0.022), lymph node metastasis (P=0.019), ki67 expression (P=0.000) and total survival (P=0.003). 4. Immunohistochemistry showed that the expression of CD80 and CD86 in TNBC tissues (3.07±1.57, 3.93±1.64) was significantly lower than those in paracancerous tissues (4.63±2.92 vs 5.23±2.85) (P=0.032 and 0.027). Conclusion: The high expression of ITGB2 in triple negative breast cancer affects the prognosis of patients.

[Effect of high expression of type â collagen α1 chain protein on the prognosis of triple negative breast cancer].

Objective: To investigate the expression of type Ⅰ collagen α1 chain protein (COL1A1) in triple negative breast cancer (TNBC), and its relationship with clinicopathological features and prognosis of TNBC. Methods: A total of 148 TNBC specimens were collected from the Affiliated Cancer Hospital of Xinjiang Medical University from 2013 to 2015. The mRNA expression of COL1A1 was detected by fluorescence quantitative RT-PCR and the protein expression of COL1A1 was detected by Western blot. The expression of COL1A1 and α-smooth muscle actin (α-SMA) in TNBC were detected by immunohistochemistry. The relationship between the expression of COL1A1 and clinicopathological parameters and prognosis of TNBC patients was analyzed. Results: The mRNA and protein expression of COL1A1 in MDA-MB-231 cells were 1.696±0.486 and 0.550±0.088, respectively, which were higher than those in MCF-10A cells (1.020±0.231 and 0.350±0.083, P=0.032, P=0.046). The mRNA and protein expression of COL1A1 in TNBC tissues were 1.632 ±0.598 and 0.733 ±0.068, respectively, which were higher than those in paracancerous tissues (1.041±0.316 and 0.612±0.016, P=0.003, P=0.039). The high expression rates of COL1A1 and α-SMA in TNBC tissues were 35.8% and 56.7% respectively, which were higher than those in paracancerous tissues (16.7% and 30.0%, P=0.041, P=0.037). The expression of COL1A1 was correlated with tumor size, TNM stage, lymph node metastasis, vascular invasion and α-SMA expression (all P<0.05). The median survival time in COL1A1 high expression group was 64 months, which was lower than that in low expression group (73 months, P<0.05). Multivariate analysis of Cox proportional hazard regression model showed that COL1A1 expression was an independent influencing factor for the survival of TNBC patients (HR=3.952, P=0.004). Conclusion: The high expression of COL1A1 in TNBC is an independent prognostic factor of TNBC patients.

Inhibition effect of exosomes-mediated Let-7a on the development and metastasis of triple negative breast cancer by down-regulating the expression of c-Myc.

OBJECTIVE: Triple negative breast cancer is typically characterized by high malignancy, easy recurrence and metastasis, and poor prognosis. However, effective treatment for triple negative breast cancer has not yet been identified. Our research explores the underlying mechanisms of exosomes in transporting Let-7a and regulating c-Myc gene and their roles in the development of triple negative breast cancer, and to provide new ideas for targeted therapy of triple negative breast cancer. PATIENTS AND METHODS: Based on previous studies that focused on the roles of c-Myc and Let-7a in the development of triple negative breast cancer, triple negative breast cancer cell lines have been constructed by c-Myc knockout and overexpression of Let-7a, respectively, to evaluate the effects of c-Myc, and Let-7a, as well as exosomes transmitting Let-7a on the development of triple negative breast cancer. RESULTS: Let-7a, which is mediated by exosomes, inhibited proliferation, migration, and invasion of MDA-MB-231 cells by binding on the 3'UTR region of the c-Myc gene and silencing of the c-Myc expression. CONCLUSIONS: Our study revealed the role of c-Myc, Let-7a, and exosomes in the development of triple negative breast cancer, which lay the theoretical foundation for further usage of exosomes to construct tumor killing vectors and for exploring specific targets for triple negative breast cancer.

[Qualitative research on factors of HIV testing among men who have sex with men in China based on Blued].

Objective: To understand the cognition and attitudes of men who have sex with men (MSM) towards HIV testing and explore in-depth reasons preventing them from testing. Methods: The function of "opinion" in Blued, a gay geo-social networking application (GSN), was adopted to collect qualitative data of ideas and attitudes towards HIV testing of the users between December 2017 and January 2018. The data was analyzed based on grounded theory approach. Results: 28 269 Blued users participated in the activity and 1 977 posted comments. Four key themes were identified, i.e. no/low risk of contracting HIV, stigmatization of HIV testing, long-term relationship and conventional impediments of HIV testing. Conclusion: The cognition and attitudes of the target population derived from the analysis of "opinion" function in Blued, such as the stigmatization of the behavior of HIV testing influencing the attitude of HIV testing, could help researchers build a more accurate detection and promotion strategy instead of a very general intervention on the public.

[Analysis of lymph node jump metastasis in papillary thyroid carcinoma].

Objective:To summarize the metastatic feature of lateral neck lymph node metastasis in papillary thyroid carcinoma.Method:Clinical and pathological data were collected from 301 patients who were first diagnosed as PTC in our hospital. These patients were divided into positive and negative status of lateral cervical lymph nodes and lymph node jump metastasis. Chi-square test and Logistic regression analysis were used to evaluate the relationship between lateral cervical lymph node status and clinicopathology.Result:Tumor size over 2cm, Unilateral thyroid gland contains multiple foci,multiple foci, capsular invasion, ultrasound feature of PTC,the main foci located in the isthmus and the pole of gland, trachea/parathyroid lymph nodes positive were associated with the lymph node jump metastasis in papillary thyroid(P<0.05).Conclusion:Multiple foci in single gland, multifocal foci, calcification and the primary tumor involving the superior pole and middle of the thyroid gland are independent influencing factors for skip lateral lymph node metastasis in PTC(P<0.05).

Soil phosphorus loss in tile drainage water from long-term conventional- and non-tillage soils of Ontario with and without compost addition.

Recent ascertainment of tile drainage a predominant pathway of soil phosphorus (P) loss, along with the rise in concentration of soluble P in the Lake Erie, has led to a need to re-examine the impacts of agricultural practices. A three-year on-farm study was conducted to assess P loss in tile drainage water under long-term conventional- (CT) and non-tillage (NT) as influenced by yard waste leaf compost (LC) application in a Brookston clay loam soil. The effects of LC addition on soil P loss in tile drainage water varied depending on P forms and tillage systems. Under CT, dissolved reactive P (DRP) loss with LC addition over the study period was 765g P ha-1, 2.9 times higher than CT without LC application, due to both a 50% increase in tile drainage flow volume and a 165% increase in DRP concentration. Under NT, DRP loss in tile drainage water with LC addition was 1447gPha-1, 5.3 times greater than that for NT without LC application; this was solely caused by a 564% increase in DRP concentration. However, particulate P loads in tile drainage water with LC application remained unchanged, relative to non-LC application, regardless of tillage systems. Consequently, LC addition led to an increase in total P loads in tile drainage water by 57 and 69% under CT and NT, respectively. The results indicate that LC application may become an environmental concern due to increased DRP loss, particularly under NT.

[Risk Factors for central lymph node metastasis in 1 988 papillary thyroid microcarcinoma patients].

Objective:To determine the risk factors that increase the neck central lymph node metastasis in papillary thyroid microcarcinoma(PTMC). Method:In this retrospective study,clinical and pathologic data were collected from patients who were first diagnosed as PTMC at the Xinjiang Medical University affiliated Tumor Hospital from January 2010 to March 2016. Chi-square test and multivariate logistic regression analysis were used to identify the risk factors of the neck central lymph node metastasis. Result:Of all 1988 patients,34.9% had the neck central lymph node metastasis. Age<45 years（P<0.05）,male（P<0.05),multifocality（P<0.05）,bilaterality（P<0.05）,tumor size >5 mm（P<0.05）,capsular invasion（P<0.05）or extrathyroidal extension（P<0.05）were significantly correlated with the neck central lymph node metastasis. Multivariate logistic regression analysis indicated that male, age <45 years, tumor size >5 mm,capsular invasion,extrathyroidal extension were independently correlated with the neck central lymph node metastasis. For patients with a solitary primary tumor, tumor location was independently correlated with the neck central lymph node metastasis.Unifocal tumor location in the lower third of the thyroid lobe was associated with the highest risk of the neck central lymph node metastasis(46.8%)(P<0.05).Multifocal tumor location was not associated with the neck central lymph node metastasis(P>0.05). Conclusion:More aggressive treatment or more frequent follow-up could be considered for patients with unfavorable features(male gender, age <45 years,tumor size >5 mm,capsular invasion,extrathyroidal extension,unifocal tumor location in the lower third of the thyroid lobe), as these patients may be at an increased risk for the neck central lymph node metastasis.

Modification of photosynthesis and growth responses to elevated CO2 by ozone in two cultivars of winter wheat with different years of release.

The beneficial effects of elevated CO2 on plants are expected to be compromised by the negative effects posed by other global changes. However, little is known about ozone (O3)-induced modulation of elevated CO2 response in plants with differential sensitivity to O3. An old (Triticum aestivum cv. Beijing 6, O3 tolerant) and a modern (T. aestivum cv. Zhongmai 9, O3 sensitive) winter wheat cultivar were exposed to elevated CO2 (714 ppm) and/or O3 (72 ppb, for 7h d(-1)) in open-topped chambers for 21 d. Plant responses to treatments were assessed by visible leaf symptoms, simultaneous measurements of gas exchange and chlorophyll a fluorescence, in vivo biochemical properties, and growth. It was found that elevated CO2 resulted in higher growth stimulation in the modern cultivar attributed to a higher energy capture and electron transport rate compared with the old cultivar. Exposure to O3 caused a greater growth reduction in the modern cultivar due to higher O3 uptake and a greater loss of photosystem II efficiency (mature leaf) and mesophyll cell activity (young leaf) than in the old cultivar. Elevated CO2 completely protected both cultivars against the deleterious effects of O3 under elevated CO2 and O3. The modern cultivar showed a greater relative loss of elevated CO2-induced growth stimulation due to higher O3 uptake and greater O3-induced photoinhibition than the old cultivar at elevated CO2 and O3. Our findings suggest that the elevated CO2-induced growth stimulation in the modern cultivar attributed to higher energy capture and electron transport rate can be compromised by its higher O3 uptake and greater O3-induced photoinhibition under elevated CO2 and O3 exposure.

Identifying crosstalk of mTOR signaling pathway of lobular breast carcinomas.

BACKGROUND: Invasive lobular carcinoma (ILC) and its variants represent 5% to 15% of all invasive breast cancers diagnoses annually. AS a serine/threonine kinase, mammalian target of rapamycin (mTOR) is often a downstream effector of PI3K/Akt (phosphatidyl inositol 3-kinase/protein kinase B) signaling pathway in breasts and many types of cancer cells. Therefore, agents that target mTOR in direct or indirect manner are being developed in anti-cancer therapy. AIM: In this study, our objective here was to explore more crosstalk pathway with mTOR signaling pathway. MATERIALS AND METHODS: We collected pathways data from published database, then based on bioinformatics methods we analyzed the significant pathways in the database, additionally, the crosstalk pathways were also analyzed which were defined as those pathways which have the overlapping genes with each other. RESULTS: As we expected, the results showed that Notch signaling pathway (hsa04330), Regulation of autophagy (hsa04140), and Adipocytokine signaling pathway (hsa04920) were linked to mTOR signaling pathway. All of them have been demonstrated participate in breast cancer progression. CONCLUSIONS: We obtained some key pathways that crosstalked with mTOR signaling pathway, we hope our study could provide novel therapeutic approaches for breast cancer.

Investigation on gene transfer from genetically modified corn (Zea mays L.) plants to soil bacteria.

Knowledge about the prevalence and diversity of antibiotic resistance genes in soil bacteria communities is required to evaluate the possibility and ecological consequences of the transfer of these genes carried by genetically modified (GM) plants to soil bacteria. The neomycin phosphotransferase gene (nptII) conferring resistance to kanamycin and neomycin is one of the antibiotic resistance genes commonly present in GM plants. In this study, we investigated kanamycin-resistant (Km(R)) and neomycin-resistant (Nm(R)) soil bacterial populations in a 3-year field trial using a commercial GM corn (Zea mays L.) carrying the nptII gene and its near isogenic line. The results showed that a portion (2.3 - 15.6 %) of cultivable soil bacteria was naturally resistant to kanamycin or neomycin. However, no significant difference in the population level of Km(R) or Nm(R) soil bacteria was observed between the GM and non-GM corn fields. The nptII gene was not detected in any of the total 3000 Km(R) or Nm(R) isolates screened by PCR. Further, total soil bacterial cells were collected through Nycodenz gradient centrifugation and bacterial community DNA was subjected to PCR. Detection limit was about 500 cells per gram of fresh soil. Our study suggests that the nptII gene was relatively rare in the soil bacterial populations and there was no evidence of gene transfer from a GM corn plant to soil bacteria based on the data from total soil bacterial communities.

Estimating dissolved reactive phosphorus concentration in surface runoff water from major Ontario soils.

Phosphorus (P) loss from agricultural land in surface runoff can contribute to eutrophication of surface water. This study was conducted to evaluate a range of environmental and agronomic soil P tests as indicators of potential soil surface runoff dissolved reactive P (DRP) losses from Ontario soils. The soil samples (0- to 20-cm depth) were collected from six soil series in Ontario, with 10 sites each to provide a wide range of soil test P (STP) values. Rainfall simulation studies were conducted following the USEPA National P Research Project protocol. The average DRP concentration (DRP30) in runoff water collected over 30 min after the start of runoff increased (p < 0.001) in either a linear or curvilinear manner with increases in levels of various STPs and estimates of degree of soil P saturation (DPS). Among the 16 measurements of STPs and DPSs assessed, DPS(M3) 2 (Mehlich-3 P/[Mehlich-3 Al + Fe]) (r2 = 0.90), DPS(M3)-3 (Mehlich-3 P/Mehlich-3 Al) (r2 = 0.89), and water-extractable P (WEP) (r2 = 0.89) had the strongest overall relationship with runoff DRP30 across all six soil series. The DPS(M3)-2 and DPS(M3)-3 were equally accurate in predicting runoff DRP30 loss. However, DPS(M3)-3 was preferred as its prediction of DRP30 was soil pH insensitive and simpler in analytical procedure, ifa DPS approach is adopted.

Alterations of p16INK4a tumour suppressor gene in mucoepidermoid carcinoma of the salivary glands.

Mucoepidermoid carcinoma (MEC) is common in the salivary glands, but alterations of the p16(INK4a) tumour suppressor gene are largely unknown. The aim of this study was to analyse p16(INK4a) gene alterations in MEC, and evaluate their significance for carcinogenesis. Thirty-eight salivary glands with MEC and six normal salivary glands were studied for p16(INK4a) alterations. In the MEC-affected group, there were 23.7% (9/38) and 13.2% (5/38) cases of homozygous deletion, and 5.3% (2/38) and 2.6% (1/38) cases of point mutation in p16(INK4a) exon 1 and exon 2, respectively. Hypermethylation of the p16(INK4a) gene promoter was found in 13 cases (13/38, 34.2%). Alterations of the p16(INK4a) gene were not found in the normal salivary glands. These findings suggest that the main mechanisms of inactivation of the p16(INK4a) gene in MEC of the salivary glands are promoter hypermethylation and homozygous deletion.

Evaluation of detection methods for genetically modified traits in genotypes resistant to European corn borer and herbicides.

Detection of genetically modified (GM) traits in corn (Zea mays L.) is urgently needed for preservation of genetic identity and marketing GM products. A laboratory study was conducted to evaluate the efficiency, accuracy, and reliability of different analytical methods to detect GM traits in corn. Samples with known fractions of GM concentrations (Bacillus thuringiensis [Bt], Liberty Link [LL] and stacked [Bt/LL] genes) from commercial seed companies and those derived from yellow kernels in a white corn ear, outcrossed by pollen of neighboring Bt hybrid, were tested by lateral flow quick test kits and by enzyme-linked immunosorbent assay (ELISA)-based test strips purchased from different companies. Liberty Link hybrids are resistant to glufosinate (Liberty or Basta) herbicides, whereas Bt corn is developed for the control of European corn borer (Ostrinia nubilalis). Selected samples of GM concentrations were also tested in a commercial laboratory using DNA-based polymerase chain reaction (PCR) test. The results demonstrated that qualitative lateral flow quick tests could detect samples containing 1% or higher Bt and 2% or higher LL concentrations within the recommended time limit of the test. Faint test lines for samples containing 0.5 to 1% Bt or 1 to 2% LL concentrations appeared if samples remained in the test cup overnight. ELISA test strips detected the Bt content semiquantitatively in the range of 0.5 to 2.0%. Grain samples derived from non-Bt corn outcrossed by neighboring Bt pollen had usually lower GM concentrations than commercial GM seed samples. Both ELISA- and DNA-based PCR tests distinguished samples with GM concentrations between 0.1 to 0.5%, but the precision of quantification at this range was very low and results were highly inconsistent.

Comparative analysis of PAH:DNA adducts formed in lung of mice exposed to neat coal tar and soils contaminated with coal tar.

7H-Benzo[c]fluorene (benzo[c]fluorene) is a major DNA adduct forming component of coal tar in lung of mice. The present study evaluated the types of PAH:DNA adducts formed from different neat coal tar samples and soils contaminated with coal tar. Mice were fed diets containing coal tar either neat or as a contaminant in an environmental soil sample for 14 days, and the types of chemical:DNA adducts formed in lung were evaluated using 32P-postlabeling and HPLC analysis. Three major DNA adducts derived respectively from benzo[b]fluoranthene (B[b]F), benzo[a]pyrene (B[a]P), and benzo[c]fluorene were detected in three of the four neat coal tar samples evaluated. In contrast, only a single major DNA adduct derived from benzo[c]fluorene was observed with the remaining tar sample. Ingestion of coal tar contaminated soil resulted in DNA adducts primarily derived from benzo[c]fluorene and B[b]F; a B[a]P derived DNA adduct was not detected. The DNA adducts derived from benzo[c]fluorene and B[b]F but not B[a]P were also observed with animals fed methylene chloride extracts of three of these soils but not the one designated A1000H soil. However, the extract of A1000H resulted in a B[a]P:DNA adduct being detected along with adducts formed from B[b]F and benzo[c]fluorene. The selective formation of the benzo[c]fluorene:DNA adduct with coal tar contaminated soils indicates that the in vivo systemic bioavailability and/or metabolism of benzo[c]fluorene is relatively high when compared to other DNA adducting hydrocarbons within coal tar. Benzo[c]fluorene may play a critical role in the potential of contaminated soil to induce a toxicological response in animals.

IL-10 and trichosanthin inhibited surface molecule expression of antigen processing cells and T-cell proliferation.

AIM: To study immunoinhibitory effects and preliminary mechanism of IL-10 and trichosanthin. METHODS: Surface molecule expression on antigen processing cells (APC) was stained with fluorescence and analyzed by FACScan. B7-1 mRNA expression was detected with nested RT-PCR. RESULTS: IL-10 2 mg.L-1 and trichosanthin 10 mg.L-1 inhibited B7-1 molecule expression. By contrast, they had not the same effects on ICAM-1. IL-10 and trichosanthin down-regulated LFA-1 expression, but had no regulatory effect on CD40. IL-10 and trichosanthin dramatically inhibited T-cell proliferation and IL-2 production. B7-1 mRNA expression was undetectable in APC treated with IL-10 and trichosanthin. CONCLUSION: IL-10 and trichosanthin inhibit surface molecule expression on APC. They exert multiple immunoinhibitory effects.

[Construction of human pLXSN-CD80 retrovirus vector and expression in CHO and PA317 cells].

CD80, a molecule on the antigen presenting cells, provide costimulation signals for T cell activation and play a key role in tumor immune. Based on our previous work of human CD80 full length cDNA cloning, a retrovirus expression vector pLXSN-CD80 was constructed. CD80 expression cells were selected by G418 from pLXSN-CD80 transfected PA317 and CHO cells by calcium phosphate. Expression, distribution and molecular weight (MW) of CD80 were measured by RIA, FACs and western blot. pLXSN-CD80 transfected CHO cells expressed relatively high level of CD80 protein (approximately the same as Raji cells) with an apparent MW of 40 kD. In the presence of G418 or not, pLXSN-CD80 transfected PA317 and CHO cells maintained CD80 expression for five months of passage. The results indicate that our construct is potent for experimental use in gene therapy.

Active site of trichosanthin acting as a ribosome-inactivating protein.

AIM: To localize the active site of ribosome inactivation of trichosanthin (Tri), a Chinese herb protein. METHODS: Hydroxylamine was used to specifically cleave the unique Asn-Gly peptide bond of Tri. Preparative SDS-polyacrylamide gel electrophoresis was applied to get 2 cleaved fragments, HATf1 and HATf2. Western blotting was used to determine the different epitopes of Tri and screen the antibodies. A cell-free system, rabbit reticulocyte lysate, was introduced to quantitate the inhibitory activity of Tri and its fragments on protein biosynthesis. RESULTS: HATf1 and HATf2 were separated with the purity of 96.9% and 80.5% respectively. HATf1, like intact Tri, retained the inhibitory activity on protein biosynthesis. The mAb No 14 and No 16 against Tri showed different immunoreactivities with 2 fragments and were selected as representatives in further blocking tests. The mAb No 14 hindered the activities of Tri and HATf1, whereas the mAb No 16 did not. CONCLUSION: The active site of Tri responsible for inhibitory activity on protein biosynthesis was on the HATf1 side near the junction of two portions.

The effects of hydrogen peroxide on DNA repair activities.

Oxygen free radicals generated by H2O2 are involved in the multistage carcinogenic process; mechanisms include carcinogen activation, oxidative DNA damage, and tumor promotion. In this study, we have evaluated another potential mechanism of H2O2 in carcinogenesis--modulation of DNA repair activities. Preexposure of human peripheral mononuclear leukocytes to H2O2 significantly inhibited DNA repair activities in response to damage induced by N-methyl-N'-nitro-N-nitrosoguanidine, measured as unscheduled DNA synthesis. The responses to H2O2 were compared in four healthy human subjects with two sample preparations on different days. Results from multivariate general linear models showed that H2O2 significantly inhibited DNA repair in a dose-dependent manner after adjustment for between- and within-subject variabilities. There was an estimate of 5.0 units (dpm/5 x 10(5) cells) decrease in induced unscheduled DNA synthesis per unit (microM) increase of H2O2 treatment. Furthermore, there was substantial variability in DNA repair activities for the same individual sampled on different days regardless of H2O2 dose level. Results from this study suggest that H2O2 not only can induce DNA damage, but also have suppressive effects on DNA repair.

Trichosanthin, an initiator of the alternative complement activation pathway.

Trichosanthin (TCS), a protein purified from the plant Trichosanthes Kirilowii Maxim, activates normal human serum complement via the alternative pathway, as shown by TCS-induced C3 conversion in normal serum and its prevention by depletion of factor B, but not with the addition of EGTA. Injection of TCS to BALB/c mice consumed the complement alternative pathway (APC) activity in serum, implying in vivo activation of the alternative pathway by TCS. Elevation of peripheral blood leucocyte count as well as protein exudation and neutrophil accumulation in the peritoneal cavities could be induced by peritoneal injection of TCS. The main effect of complement activation by TCS was demonstrated to be induction of neutrophil accumulation.