Impact of environmental factors on growth and satratoxin G production by strains of Stachybotrys chartarum

The black mould Stachybotrys chartarum and its mycotoxins have been linked to damp building-associated illnesses. The objective of this study was to determine the effects of water availability (water activity, aw) and temperature on growth and production of satratoxin G (SG) by a macrocyclic trichothecene-producing strain (IBT 7711) and non-producing strain (IBT 1495) of S. chartarum. Growth studies were carried out on potato dextrose agar modified with glycerol to 0.995-0.92 aw at 10-37 °C. Growth extension was measured and the cultures were extracted after 10 days and a competitive enzyme-linked immunosorbent assay (ELISA) method used to quantify the SG content. Growth was optimal at 25 to 30 °C at 0.995 aw, but this was modified to 0.98 aw at 30 °C for both strains (1.4-1.6 mm/day, respectively). The ELISA method revealed that, in contrast to growth, SG production was maximal at 20 °C with highest production at 0.98 aw (approximately 250 μg/g mycelia). When water was freely available (0.995 aw), SG was maximally produced at 15 °C and decreased as temperature was increased. Interestingly, the strain classified as a non-toxigenic produced very low amounts of SG (<1.6 μg/g mycelia) that were maximal at 25 °C and 0.98 aw. Contour maps for growth and SG production were developed from these data sets. These data have shown, for the first time, that growth and SG production profiles are very different in relation to key environmental conditions in the indoor environment. This will be very useful in practically determining the risk from exposure to S. chartarum and its toxins in the built environment.

Pesticide poisonings in South Korea: findings from the National Hospital Discharge Survey 2004-2006

OBJECTIVES

Pesticide poisoning stands as a major public health issue worldwide. The objective of this study was to examine the epidemiologic characteristics of pesticide-related hospitalizations in South Korea.

METHODS

Data from the Korea National Hospital Discharge Survey were analyzed to describe the epidemiologic characteristics of pesticide poisoning among hospitalized patients from 2004 through 2006. Pesticide-related hospitalizations were identified using the International Classification of Diseases, Tenth Revision codes. National estimates of pesticide-related hospitalizations were calculated using sampling weights for number of hospitalizations.

RESULTS

A total of 25,982 pesticide-related hospitalizations were estimated during the years 2004-2006, yielding an average annual pesticide-related hospitalization rate of 17.8 per 100,000 population in South Korea. Age-specific rates for pesticide-related hospitalization increased with age, with the highest rate noted among those aged 70 or above. The majority of pesticide-related hospitalization was cases of intentional poisoning in rural areas. Seasonal variation in the rate was observed, with summer being the highest among both men and women.

CONCLUSIONS

Pesticide-related hospitalization is prevalent and demonstrates demographic and seasonal and regional variations. More effective strategies to reduce pesticide-related hospitalizations are required in South Korea.

Integrated genomic analyses identify WEE1 as a critical mediator of cell fate and a novel therapeutic target in acute myeloid leukemia

Acute myeloid leukemia (AML) remains a therapeutic challenge despite increasing knowledge about the molecular origins of the disease, as the mechanisms of AML cell escape from chemotherapy remain poorly defined. We hypothesized that AML cells are addicted to molecular pathways in the context of chemotherapy and used complementary approaches to identify these addictions. Using novel molecular and computational approaches, we performed genome-wide shRNA screens to identify proteins that mediate AML cell fate after cytarabine exposure, gene expression profiling of AML cells exposed to cytarabine to identify genes with induced expression in this context, and examination of existing gene expression data from primary patient samples. The integration of these independent analyses strongly implicates cell cycle checkpoint proteins, particularly WEE1, as critical mediators of AML cell survival after cytarabine exposure. Knockdown of WEE1 in a secondary screen confirmed its role in AML cell survival. Pharmacologic inhibition of WEE1 in AML cell lines and primary cells is synergistic with cytarabine. Further experiments demonstrate that inhibition of WEE1 prevents S-phase arrest induced by cytarabine, broadening the functions of WEE1 that may be exploited therapeutically. These data highlight the power of integrating functional and descriptive genomics, and identify WEE1 as potential therapeutic target in AML.

Runoff load estimation of particulate and dissolved nitrogen in Lake Inba watershed using continuous monitoring data on turbidity and electric conductivity

Easy-to-measure surrogate parameters for water quality indicators are needed for real time monitoring as well as for generating data for model calibration and validation. In this study, a novel linear regression model for estimating total nitrogen (TN) based on two surrogate parameters is proposed based on evaluation of pollutant loads flowing into a eutrophic lake. Based on their runoff characteristics during wet weather, electric conductivity (EC) and turbidity were selected as surrogates for particulate nitrogen (PN) and dissolved nitrogen (DN), respectively. Strong linear relationships were established between PN and turbidity and DN and EC, and both models subsequently combined for estimation of TN. This model was evaluated by comparison of estimated and observed TN runoff loads during rainfall events. This analysis showed that turbidity and EC are viable surrogates for PN and DN, respectively, and that the linear regression model for TN concentration was successful in estimating TN runoff loads during rainfall events and also under dry weather conditions.

P5-14-02: Clinicopathologic and Prognostic Difference of Screen Detected Breast Cancer Compared with Symptomatic Breast Cancer

Background: Breast cancer screening program makes it possible to detect early cancer, thus to reduce breast cancer mortality. The authors studied clinicopathologic characteristics and prognosis of screen detected invasive breast cancer compared with symptomatic breast cancer. Furthermore, we compared the result according to molecular subtypes (luminal A, luminal B, Her2, triple negative), so intended to identify the role of screening in each subtypes. Material and Methods: From January 2002 to June 2008, 3141 patients who underwent operation for the treatment of invasive ductal carcinoma(NOS) at Samsung medical center were included. Among them, 1025 patient were screen detected, 2116 patient were symptomatic, out of screening over 2 years. We reviewed the medical records retrospectively.

Result: Screen detected breast cancer was associated with older patients, smaller tumor size, more hormone receptor- positive, less lymph node involvement, lower stage and reduced mortality compared with symptomatic breast cancer (P &lt; .001). According to the molecular subtype, in luminal A subtype, the result shows better pathologic feature and also favorable overall and recur-free survial significantly.

P3-14-16: Molecular Phenotype and the Use of HER-2 Targeted Agents Influence the Accuracy of Breast MRI after Neoadjuvant Chemotherapy

Background: Improved understanding of factors affecting the accuracy of breast magnetic resonance imaging (MRI) after neoadjuvant systemic therapy (NST) can lead to more tailored use of MRI in deciding surgical extent after NST.

Materials and Methods: We analyzed the imaging and clinicopathologic data of 463 patients who underwent NST. We aimed to investigate whether the molecular subtypes, as well as the use of targeted therapies, were associated with changes in the accuracy of MRI predicting residual tumor extent.

Results: The accuracy of MRI predicting the residual tumor extent was most accurate in triple negative breast cancer and was least accurate in Luminal A subtype (Pearson's correlation coefficient of 0.754 and 0.531, respectively). Multivariate analysis suggested estrogen receptor status as an independent factor influencing the MRI accuracy. In HER2−amplified tumors, the use of HER2−targeted agents was associated with less accurate MRI prediction. Dual HER2−blockade by using trastuzumab and pertuzumab resulted in lowest MRI accuracy among the patients treated with HER2−targeted agents.

Conclusion: The accuracy of MRI in predicting residual tumor extent was lowest in ER positive tumors treated with NST. In HER2 positive tumors, the use of HER2−targeted agents resulted in less accurate MRI after NST.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-14-16.

P2-08-12: Additional Lesion Found in Preoperative Breast MRI; Is Routine Use Justified?

Preoperative breast MRI has been increasingly performed in patients with newly diagnosed breast cancer due to its high sensitivity in assessing the extent and additional malignant foci. But due to it's low specificity, role of routine preoperative breast MRI has become an issue. In this study we aught to analyze the characteristics of the additional lesion found in preoperative breast MRI and to evaluate the clinicopathological factors in association with likelihood of having additional malignancy.

We retrospectively reviewed 2491 patients who undergone surgery due to breast cancer in Seoul National University Hospital(SNUH) between Jan 2006 and Dec 2010. Neoadjuvant chemotherapy cases, patients undergone initial sonography in other center or ones with prior excision were excluded and total 1068 patients were analyzed. The additional lesion was defined as the lesion not found in initial sonography and detected in preoperative breast MRI. The pathology of the additional lesion was reviewed and the association between the clinicopathologic factors and additional malignancy were evaluated. Accuracy of breast MRI was estimated regarding cancer yield, positive predictive value(PPV).

Mean age at diagnosis was 50.9 years (21 to 85 years). Overall detection rate of additional lesion was 26.2%(280 out of 1068). Mean size of the additional lesion was 9.8mm(3-51). Additional lesions consist of 99(35.4% of 280) C4 or higher, 174(62.1% of 280) below C4, 7(2.5% of 280) C0 lesions. Among them 100 patients undergone onstage surgery. 5(55% of 100) lesions were in ipsilateral breast and 45(45% of 100) in contralateral breast. Breast conserving surgery and mastectomy rate of the 100 onstage-operation group was 36% versus 64% and 64.6% versus 35.4% in total 1068 patients, showing no significant change of operation method of the primary cancer owing to additional lesion.

Among the 100 patients, 54(19.3% of 280) were benign, 3(1.1% of 280) were atypical ductal hyperplasia, 13(4.6% of 280) were in situ carcinoma, 19(6.8% of 280) were invasive carcinoma and 11(3.9% of 280) were unknown. Cancer yield was 2.99%(32 out of 1068) and PPV of preoperative breast MRI was 39.0%(31 out of 82).

In univariate analysis, young age and premenopausal patients showed to have higher rate of additional cancer found in MRI(p=0.022, p=0.036). Breast density, size and LN status of the primary cancer didn't show significancy and neither the hormone receptor status with each p value 0.705, 0.381, 0.973, 0.375 respectively. Lobular carcinoma(ILC or mixed IDC with ILC) and low grade carcinoma showed significancy of having additional malignancy (p=0.019, 0.022). In multivariate analysis age, low grade carcinoma and lobular carcinoma showed independent association with p value 0.014, 0.039, 0.035 respectively(HR 0.95, 95%CI:0.94 o 0.99),(HR 0.39, 95%CI:0.16 to 0.96),(HR 5.66, 95%CI:1.13 to 28.39).

Routine preoperative breast MRI use can result in overtreatment also with delay in surgical management. In our data, younger age, low grade carcinoma, lobular carcinoma showed independent association having additional malignant foci in breast MRI. With the basis of mammography and sonography, preoperative breast MRI should only be done when additional gain is considered to overcome the flaws.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-08-12.

Body mass, tobacco smoking, alcohol drinking and risk of cancer of the small intestine--a pooled analysis of over 500,000 subjects in the Asia Cohort Consortium

BACKGROUND

The evidence for a role of tobacco smoking, alcohol drinking, and body mass index (BMI) in the etiology of small intestine cancer is based mainly on case-control studies from Europe and United States.

SUBJECTS AND METHODS

We harmonized the data across 12 cohort studies from mainland China, Japan, Korea, Singapore, and Taiwan, comprising over 500,000 subjects followed for an average of 10.6 years. We calculated hazard ratios (HRs) for BMI and (only among men) tobacco smoking and alcohol drinking.

RESULTS

A total of 134 incident cases were observed (49 adenocarcinoma, 11 carcinoid, 46 other histologic types, and 28 of unknown histology). There was a statistically non-significant trend toward increased HR in subjects with high BMI [HR for BMI>27.5 kg/m2, compared with 22.6-25.0, 1.50; 95% confidence interval (CI) 0.76-2.96]. No association was suggested for tobacco smoking; men drinking>400 g of ethanol per week had an HR of 1.57 (95% CI 0.66-3.70), compared with abstainers.

CONCLUSIONS

Our study supports the hypothesis that elevated BMI may be a risk factor for small intestine cancer. An etiologic role of alcohol drinking was suggested. Our results reinforce the existing evidence that the epidemiology of small intestine cancer resembles that of colorectal cancer.

First Report of Root Rot Caused by Sclerotium rolfsii on Daucus carota var. sativa in Southern Korea

Carrot (Daucus carota var. sativa DC.), an important root vegetable, is cultivated widely because of its dietary fiber and beta carotene. In June 2009 and June 2010, a disease suspected as root rot of carrot caused by Sclerotium rolfsii occurred in a 5-ha field in Jinju, Korea. Early symptoms consisted of water-soaked lesions on root and lower stem tissue near the soil line. Infected plants gradually withered and white mycelial mats appeared on the surface of roots. Numerous sclerotia were often produced on stem and root surfaces in contact with the soil. The heavily infected carrots became rotted and blighted and the whole plant eventually died. The freshly isolated pathogenic fungus was grown on potato dextrose agar (PDA) and examined microscopically. Optimum temperature for mycelia growth or sclerotia formation was 25 to 30°C. Numerous globoid sclerotia formed on the PDA after 18 days of mycelial growth. The sclerotia (1 to 3 mm in diameter) were white at first and then gradually turned dark brown. Aerial mycelia usually formed, consisting of many narrow hyphal strands 3 to 9 μm wide. The white mycelium formed a typical clamp connection after 5 days of growth at optimum temperature. To fulfill Koch's postulates, 10 carrot seedlings were inoculated with colonized agar discs (6 mm in diameter) of the causal fungus directly on the root and incubated in a humid chamber at 25°C for 24 h. Ten carrot seedlings were inoculated similarly with agar discs as the control treatment. After this period, the inoculated and noninoculated plants were maintained in a greenhouse. Eight days after inoculation, the disease symptoms seen in the field were reproduced and the fungus was reisolated from the artificially inoculated plants. To confirm identity of the causal fungus, the complete internal transcribed spacer (ITS) rDNA region of the causal fungus was amplified using the primers ITS1 and ITS4 (2) and sequenced. The resulting sequence of 684 bp was deposited in GenBank (Accession No. JF342557). The sequence was 99% similar to sequences of Athelia rolfsii (Sclerotium rolfsii) in GenBank. Cultures of S. rolfsii have been deposited with the Korean Agricultural Culture Collection (KACC 45154), National Academy of Agricultural Science, Korea. On the basis of symptoms, fungal colonies, the ITS sequence, and the pathogenicity test on the host plant, this fungus was identified as S. rolfsii Saccardo (1). To our knowledge, this is the first report of root rot of carrot caused by S. rolfsii in Korea. This disease is highly dependent upon environmental conditions, including warm weather and high humidity. Recent occurrence of the disease suggests that S. rolfsii could spread widely. References: (1) J. E. M. Mordue. CMI Descriptions of Pathogenic Fungi and Bacteria. No. 410, 1974. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, Inc., New York, 1990.

Development of Magnetically Suspended Vaneless Centrifugal Blood Pump for Cardiopulmonary Bypass

An ideal blood pump would provide sufficient flow rate against vessel pressure without hemolysis or thrombus formation. In preceding studies, it is known that non-contact operation by magnetic bearing system gives high mechanical reliability, low hemolysis and low thrombus formation. Therefore, in the present study a magnetically suspended vaneless centrifugal blood pump (MSVC-BP) has been developed for the use of cardiopulmonary bypass, in which the magnetic suspension centers the centrifugal rotor avoiding any contact. To predict the flow pattern in the pump head and to calculate shear stress on the rotor, numerical analysis has been performed using the TASCflow®. In vitro tests of hydrodynamic performance of the present pump have been carried out in mock circular system with glycerin solution, attaining a maximum flow rate of 12 L/min at 2200 rpm. In vivo tests of hemodynamic performance of the pump have also led to reasonable results for clinical usage.

Flow cytometry analysis: a quantitative method for collagen VI deficiency screening

Mutations in COL6A1, COL6A2 and COL6A3 genes result in collagen VI myopathies: Ullrich congenital muscular dystrophy (UCMD), Bethlem myopathy (BM) and intermediate phenotypes. At present, none of the existing diagnostic techniques for evaluating collagen VI expression is quantitative, and the detection of subtle changes in collagen VI expression remains challenging. We investigated flow cytometry analysis as a means of quantitatively measuring collagen VI in primary fibroblasts and compared this method with the standard method of fibroblast collagen VI immunohistochemical analysis. Eight UCMD and five BM molecularly confirmed patients were studied and compared to five controls. Flow cytometry analysis consistently detected a reduction of collagen VI of at least 60% in all UCMD cases. In BM cases the levels of collagen VI were variable but on average 20% less than controls. Flow cytometry analysis provides an alternative method for screening for collagen VI deficiency at the protein level in a quantitative, time and cost-effective manner.