Hyperprogressive disease during PD-1/PD-L1 blockade in patients with non-small-cell lung cancer.

BACKGROUND: Immune checkpoint blockade with Programmed cell death 1 (PD-1)/PD-L1 inhibitors has been effective in various malignancies and is considered as a standard treatment modality for patients with non-small-cell lung cancer (NSCLC). However, emerging evidence show that PD-1/PD-L1 blockade can lead to hyperprogressive disease (HPD), a flair-up of tumor growth linked to dismal prognosis. This study aimed to evaluate the incidence of HPD and identify the determinants associated with HPD in patients with NSCLC treated with PD-1/PD-L1 blockade. PATIENTS AND METHODS: We enrolled patients with recurrent and/or metastatic NSCLC treated with PD-1/PD-L1 inhibitors between April 2014 and November 2018. Clinicopathologic variables, dynamics of tumor growth, and treatment outcomes were analyzed in patients with NSCLC who received PD-1/PD-L1 blockade. HPD was defined according to tumor growth kinetics (TGK), tumor growth rate (TGR), and time to treatment failure (TTF). Immunophenotyping of peripheral blood CD8+ T lymphocytes was conducted to explore the potential predictive biomarkers of HPD. RESULTS: A total of 263 patients were analyzed. HPD was observed in 55 (20.9%), 54 (20.5%), and 98 (37.3%) patients according to the TGK, TGR, and TTF. HPD meeting both TGK and TGR criteria was associated with worse progression-free survival [hazard ratio (HR) 4.619; 95% confidence interval (CI) 2.868-7.440] and overall survival (HR, 5.079; 95% CI, 3.136-8.226) than progressive disease without HPD. There were no clinicopathologic variables specific for HPD. In the exploratory biomarker analysis with peripheral blood CD8+ T lymphocytes, a lower frequency of effector/memory subsets (CCR7-CD45RA- T cells among the total CD8+ T cells) and a higher frequency of severely exhausted populations (TIGIT+ T cells among PD-1+CD8+ T cells) were associated with HPD and inferior survival rate. CONCLUSION: HPD is common in NSCLC patients treated with PD-1/PD-L1 inhibitors. Biomarkers derived from rationally designed analysis may successfully predict HPD and worse outcomes, meriting further investigation of HPD.

Co-clinical trials demonstrate predictive biomarkers for dovitinib, an FGFR inhibitor, in lung squamous cell carcinoma.

BACKGROUND: We conducted co-clinical trials in patient-derived xenograft (PDX) models to identify predictive biomarkers for the multikinase inhibitor dovitinib in lung squamous cell carcinoma (LSCC). METHODS: The PDX01-02 were established from LSCC patients enrolled in the phase II trial of dovitinib (NCT01861197) and PDX03-05 were established from LSCC patients receiving surgery. These five PDX tumors were subjected to in vivo test of dovitinib efficacy, whole exome sequencing and gene expression profiling. RESULTS: The PDX tumors recapitulate histopathological properties and maintain genomic characteristics of originating tumors. Concordant with clinical outcomes of the trial enrolled-LSCC patients, dovitinib produced substantial tumor regression in PDX-01 and PDX-05, whereas it resulted in tumor progression in PDX-02. PDX-03 and -04 also displayed poor antitumor efficacy to dovitinib. Mutational and genome-wide copy number profiles revealed no correlation between genomic alterations of FGFR1-3 and sensitivity to dovitinib. Of note, gene expression profiles revealed differentially expressed genes including FGF3 and FGF19 between PDX-01 and 05 and PDX-02-04. Pathway analysis identified two FGFR signaling-related gene sets, FGFR ligand binding/activation and SHC-mediated cascade pathway were substantially up-regulated in PDX-01 and 05, compared with PDX-02-04. The comparison of gene expression profiles between dovitinib-sensitive versus -resistant lung cancer cell lines in the Cancer Cell Line Encyclopedia database also found that transcriptional activation of 18 key signaling components in FGFR pathways can predict the sensitivity to dovitinib both in cell lines and PDX tumors. These results highlight FGFR pathway activation as a key molecular determinant for sensitivity to dovitinib. CONCLUSIONS: FGFR gene expression signatures are predictors for the response to dovitinib in LSCC.

Association between recovery from Bell's palsy and body mass index.

BACKGROUND: Although many factors have been found to be involved in recovery from Bell's palsy, no study has investigated the association between recovery from Bell's palsy and obesity. This study therefore evaluated the association between recovery from Bell's palsy and body mass index (BMI). METHODS: Subjects were classified into five groups based on BMI (kg/m2 ). Demographic and clinical characteristics were compared among these groups. Assessed factors included sex, age, time from paralysis to visiting a hospital, the presence of comorbidities such as diabetes mellitus and hypertension, degree of initial facial nerve paralysis by House-Brackmann (H-B) grade and neurophysiological testing, and final recovery rate. RESULTS: Based on BMI, 37 subjects were classified as underweight, 169 as normal weight, 140 as overweight, 155 as obese and 42 as severely obese. Classification of the degree of initial facial nerve paralysis as moderate or severe, according to H-B grade and electroneurography, showed no difference in severity of initial facial paralysis among the five groups (P > 0.05). However, the final recovery rate was significantly higher in the normal weight than in the underweight or obese group (P < 0.05). CONCLUSIONS: Obesity or underweight had no effect on the severity of initial facial paralysis, but the final recovery rate was lower in the obese and underweight groups than in the normal group.

LAMC2 enhances the metastatic potential of lung adenocarcinoma.

Lung cancer is the number one cancer killer, and metastasis is the main cause of high mortality in lung cancer patients. However, mechanisms underlying the development of lung cancer metastasis remain unknown. Using genome-wide transcriptional analysis in an experimental metastasis model, we identified laminin γ2 (LAMC2), an epithelial basement membrane protein, to be significantly upregulated in lung adenocarcinoma metastatic cells. Elevated LAMC2 increased traction force, migration, and invasion of lung adenocarcinoma cells accompanied by the induction of epithelial-mesenchymal transition (EMT). LAMC2 knockdown decreased traction force, migration, and invasion accompanied by EMT reduction in vitro, and attenuated metastasis in mice. LAMC2 promoted migration and invasion via EMT that was integrin ß1- and ZEB1-dependent. High LAMC2 was significantly correlated with the mesenchymal marker vimentin expression in lung adenocarcinomas, and with higher risk of recurrence or death in patients with lung adenocarcinoma. We suggest that LAMC2 promotes metastasis in lung adenocarcinoma via EMT and may be a potential therapeutic target.

First Report of Bacterial Leaf Blight of Carrot Caused by Xanthomonas hortorum pv. carotae in Korea.

In December 2012, symptoms of typical bacterial leaf blight were observed on carrot plants (Daucus carota L. subsp. sativus) cultivated in commercial fields in Kujwa, Jeju, Korea. The disease was detected in 40% of 50 fields surveyed with an incidence of 10% on average. The bacterial leaf blight lesions on leaf blades were elongated, dark brown to black with water-soaked edges and chlorotic halos. Lesions were also crescent-shaped to V-shaped on leaflets. Four bacterial isolates were recovered on trypticase soy agar from leaf lesions that were surface-sterilized in 70% ethyl alcohol for 20 s. Identity of the isolates was confirmed by PCR product (1,266-bp) using a specific primer set for Xanthomonas hortorum pv. carotae (Kendrick 1934) Vauterin et al. 1995, XhcPP03 (1). All isolates were gram-negative, aerobic rods with a single polar flagellum. Isolates were positive for catalase and negative for oxidase. In phenotypic tests for differentiation of Xanthomonas (2), the isolates positive for mucoid growth on yeast extract-dextrose-calcium carbonate agar, growth at 35°C, hydrolysis of esculin, protein digestion, alkaline in litmus milk, acid production from arabitol, and utilization of glycerol and melibiose. The isolates were negative for growth on SX medium, hydrolysis of starch, and ice nucleation. The gyrB gene (863 bp) and the rpoD gene (870 bp) were sequenced to aid identification of the original isolates using published PCR primer sets, Xgyr1BF/Xgyr1BR and XrpoD1F/XrpoD1R (4), respectively. Sequences of the gyrB gene (GenBank accessions KC920729 to KC920732) from the carrot isolates shared 100% sequence identity with that of the X. hortorum pv. carotae strain NCPPB 425 (EU285243). In phylogenetic analyses based on the partial sequences of the gyrB and the rpoD genes for Xanthomonas spp. available at NCBI (4), and sequences of the carrot isolates (KC920734 to KC920737 for rpoD gene) using the Neighbor-joining method in MEGA Version 5.1 (3), the isolates were clustered in the X. hortorum-cynarae-garnderi group. Pathogenicity of the isolates was tested by spray inoculation with a bacterial suspension (106 CFU/ml) prepared in sterile distilled water at 6 to 7 true-leaf stage (three plants per isolate). Sterile distilled water was used as negative control. The inoculated plants were incubated in a growth chamber (25°C and 95% relative humidity [RH]) for 15 hr, and then transferred to a greenhouse at 24 to 28°C and 65% RH. Characteristic leaf blight symptoms developed on inoculated carrot plants, while no symptoms were observed on the negative control plants 14 days after inoculation. The bacterium was re-isolated from symptomatic tissue and the identity confirmed through gyrB gene sequence analysis (4). Based on PCR, morphological and phenotypic tests, sequence analysis, and pathogenicity assays, the isolates were identified as X. hortorum pv. carotae. To our knowledge, this is the first report of bacterial leaf blight of carrot caused by X. hortorum pv. carotae in Korea. The detection of this pathogen could have a significant economic impact due to yield losses from disease development. Consolidation of quarantine inspection on imported carrot seeds needs to control an outbreak of the disease. Crop rotation and plowing are recommended to reduce incidence of the disease in the infested fields. References: (1) J. A. Kimbrel et al. Mol. Plant Pathol. 12:580, 2011. (2) N. W. Schaad et al. Page 189 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. N. W. Schaad et al., eds. The American Phytopathological Society, St. Paul, MN, 2001. (3) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011. (4) J. M. Young et al. Syst. Appl. Microbiol. 31:366, 2008.

The frequency and impact of ROS1 rearrangement on clinical outcomes in never smokers with lung adenocarcinoma.

BACKGROUND: To determine the frequency and predictive impact of ROS1 rearrangements on treatment outcomes in never-smoking patients with lung adenocarcinoma. PATIENTS AND METHODS: We concurrently analyzed ROS1 and ALK rearrangements and mutations in the epidermal growth factor receptor (EGFR), and KRAS in 208 never smokers with lung adenocarcinoma. ROS1 and ALK rearrangements were identified by fluorescent in situ hybridization. RESULTS: Of 208 tumors screened, 7 (3.4%) were ROS1 rearranged, and 15 (7.2%) were ALK-rearranged. CD74-ROS1 fusions were identified in two patients using reverse transcriptase-polymerase chain reaction. The frequency of ROS1 rearrangement was 5.7% (6 of 105) among EGFR/KRAS/ALK-negative patients. Patients with ROS1 rearrangement had a higher objective response rate (ORR; 60.0% versus 8.5%; P = 0.01) and a longer median progression-free survival (PFS; not reached versus 3.3 months; P = 0.008) to pemetrexed than those without ROS1/ALK rearrangement. The PFS to EGFR-tyrosine kinase inhibitors in patients harboring ROS1 rearrangement was shorter than those without ROS1/ALK rearrangement (2.5 versus 7.8 months; P = 0.01). CONCLUSIONS: The frequency of ROS1 rearrangements in clinically selected patients is higher than that reported for unselected patients, suggesting that ROS1 rearrangement is a druggable target in East-Asian never smokers with lung adenocarcinoma. Given the different treatment outcomes to conventional therapies and availability of ROS1 inhibitors, identification of ROS1 rearrangement can lead to successful treatment in ROS1-rearranged lung adenocarcinomas.

Image analysis of peripheral compression artefacts of ThinPrep(®) liquid-based cytology preparations.

OBJECTIVE: ThinPrep (TP), one of the Food and Drug Administration-approved liquid-based cytology (LBC) preparations, is widely used for gynaecological and non-gynaecological cytology samples. A unique physical artefact caused by the compression at the periphery in TP slides has not been adequately evaluated to date. METHODS: We processed four established tumour cell lines (MKN28, MKN45, KG-1 and NB4) and mononuclear cells isolated from whole blood over Ficoll-Plaque for TP preparations. For this part of the study, we included five normal cervical LBC preparations. We then auto-counted and auto-measured the area, mean grey value and Feret's diameter in both the inner disc and peripheral rim of the preparations by image morphometry. In addition, we compared the distribution of atypical cell groups in the peripheral rim and inner disc of 132 lung aspirates, 80 thyroid aspirates, 212 cerebrospinal fluids (CSFs) and 50 gynaecological samples. RESULTS: The areas and Feret's diameters of the cytoplasm in the peripheral compressed rim area were statistically larger than those of cells in the inner disc. The mean grey values of cells (cytoplasm and nucleus) in the peripheral compression rim were also smaller than those in the inner disc cells, leading to decreases in nuclear and cytoplasmic chromatism. Except for the mean grey values, the differences were not significant in the cervical samples. CONCLUSIONS: Cellular morphology may be markedly distorted in the peripheral rim, regardless of cell malignancy, which may lead to the misinterpretation of cells during the screening. Accordingly, cytological diagnosis based on the findings within the peripheral rim should take this phenomenon into account. Compressed cells found in the peripheral rim should be interpreted with caution when TP slides are used for cytopathological diagnosis.

First Report of Bacterial Leaf Spot of Witloof, Caused by Pseudomonas cichorii in Korea.

In August 2011, bacterial leaf spot was observed on witloof (Cichorium intybus L. var. foliosum) grown in a commercial field with 15% incidence in Injae, Korea. Symptoms on leaves included irregular brown to reddish brown spots in the center. Bacterial streaming from the lesions was observed microscopically. Bacterial isolates (BC3286, BC3287, and BC3308-BC3310) were recovered on Trypticase soy agar from lesions surface-sterilized in 70% ethyl alcohol for 30 s. The isolates were gram negative, urease negative, fluorescent on King's B agar, and had aerobic rods with 2 to 6 polar flagella. Pathogenicity tests were separately performed in different greenhouses located in Suwon (National Academy of Agricultural Science) and Chuncheon (Gangwondo Agricultural Research and Extension Services) in Korea. Pathogenicity was confirmed by spray inoculation of healthy, 10-day-old leaves of witloof plants (two plants/isolate) with a suspension of original field isolate (106 CFU/ml). Sterile distilled water was used as negative control. The inoculated plants were incubated in a growth chamber (25°C and 95% relative humidity [RH]) overnight, then transferred to a greenhouse at 23 to 27°C and 60 to 70% RH. Characteristic leaf spot symptoms were observed on inoculated witloof plants 8 days after inoculation. No symptoms were observed on control plants. The bacterium reisolated from the inoculated leaves was confirmed by analyzing sequence of the gyrB gene with direct sequencing method of PCR products using primers gyr-F and gyr-R (2). The sequence of reisolated bacteria shared 100% similarity with inoculated ones. In LOPAT (1) tests, all isolates and the reference strain of Pseudomonas cichorii CFBP2101T (=BC2595) were levan negative, oxidase positive, potato rot negative, arginine dihydrolase negative, and tobacco hypersensitivity positive, indicative of group III (-, +, -, -, +) of fluorescent pseudomonads. The 16S rRNA (1,408 bp), and gyrB (676 bp) regions were sequenced to aid in identification of the original field isolates as well as P. cichorii CFBP 2101T (=BC2595) using reported sets of PCR primers, fD1/rP2 and gyr-F/gyr-R, respectively (2,4). Phylogenetic analyses based on partial sequences of the gyrB and the 16S rRNA of Psudomonas spp. available in GenBank, the reference strain of P. cichorii CFBP2101T (=BC2595), and the witloof field isolates were conducted using the neighbor-joining method with Juke-Cantor model of distance calculation in MEGA version 5.1 (3). The isolates and the reference strain of P. cichorii CFBP2101T (=BC2595) was clustered in one group with P. cichorii strains in both phylogenetic trees based on the two sequences. Sequences of the 16S rRNA region had a distance index value ranging from 0.000 to 0.001 between the reference strain of P. cichori CFBP2101T (GenBank JX913784) and the field isolates (JX913785 to JX913789), and ranged from 0.000 to 0.001 within the field isolates. Sequences of the gyrB region had a distance index value ranging 0.029 to 0.033 between the reference strain (JX913790) and the field isolates (JX913791 to JX913795), and ranged from 0.000 to 0.041 within the field isolates. To our knowledge, this is the first report of bacterial leaf spot of witloof caused by P. cihorii in Korea. P. cichorii has a wide host range, and an important economic impact on vegetables. The disease is expected to result in a significant economic impact on root production of witloof in Korea. References: (1) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (2) H. Sawada et al. J. Mol. Evol. 49:627, 1999. (3) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011. (4) W. G. Weinsburg et al. J. Bacteriol. 173, 697, 1991.

First Report of Fusarium oxysporum f. sp. lycopersici Race 3 Causing Fusarium Wilt on Tomato in Korea.

In July 2010, fusarium wilt symptoms of tomato (Lycopersicon esculentum Mill.) plants were found in two commercial greenhouses in the Damyang area of Korea. Approximately 1% of 7,000 to 8,000 tomato plants were wilted and chlorotic in each greenhouse. The vascular tissue was usually dark brown and the discoloration extended to the apex. Fragments (each 5 × 5 mm) of the symptomatic tissue were surface-sterilized with 1% NaOCl for 1 min, then rinsed twice in sterilized distilled water (SDW). The tissue pieces were placed on water agar and incubated at 25°C for 4 to 6 days. Nine Fusarium isolates were obtained from four diseased plants, of which three isolates were identified as F. oxysporum based on morphological characteristics on carnation leaf agar medium and DNA sequences of the translation elongation factor 1-alpha (EF-1α) gene (2). Macroconidia were mostly 3- to 5-septate, slightly curved, and 28 to 53 × 2.8 to 5.2 µm. Microconidia were abundant, borne in false heads or short monophialides, generally single-celled, oval to kidney shaped, and 5 to 23 × 3 to 5 µm. Chlamydospores were single or in short chains. The EF-1α gene was amplified from three isolates by PCR assay using ef1 and ef2 primers (3), and the amplification products were sequenced. The nucleotide sequences obtained were deposited in GenBank (Accession Nos. KC491844, KC491845, and KC491846). BLASTn analysis showed 99% homology with the EF-1α sequence of F. oxysporum f. sp. lycopersici MN-24 (HM057331). Pathogenicity tests and race determination were conducted using root-dip inoculation (4) on seedlings of tomato differential cultivars: Ponderosa (susceptible to all races), Momotaro (resistant to race 1), Walter (resistant to races 1 and 2), and I3R-1 (resistant to all races). A spore suspension was prepared by flooding 5-day-old cultures on potato dextrose agar with SDW. Plants at the first true-leaf stage were inoculated by dipping the roots in the spore suspension (1 × 106 conidia/ml) for 10 min. Inoculated plants were transplanted into pots containing sterilized soil, and maintained in the greenhouse at 25/20°C (12/12 h). Twenty-four seedlings of each cultivar were arranged into three replications. An equal number of plants of each cultivar dipped in water were used as control treatments. Disease reaction was evaluated 3 weeks after inoculation, using a disease index on a scale of 0 to 4 (0 = no symptoms, 1 = slightly swollen and/or bent hypocotyl, 2 = one or two brown vascular bundles in the hypocotyl, 3 = at least two brown vascular bundles and growth distortion, 4 = all vascular bundles brown and the plant either dead or very small and wilted). All isolates caused symptoms of fusarium wilt on all cultivars except I3R-1, indicating that the isolates were race 3. The pathogen was reisolated from the discolored vascular tissue of symptomatic plants. Control plants remained asymptomatic, and the pathogen was not reisolated from the vascular tissue. Fusarium wilt of tomato caused by isolates of F. oxysporum f. sp. lycopersici races 1 and 2 has been reported previously; however, race 3 has not been reported in Korea (1). To our knowledge, this is the first report of isolates of F. oxysporum f. sp. lycopersici race 3 on tomato in Korea. References: (1) O. S. Hur et al. Res. Plant Dis. 18:304, 2012 (in Korean). (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006. (3) K. O'Donnell et al. Proc. Nat. Acad. Sci. 95:2044, 1998. (4) M. Rep et al. Mol. Microbiol. 53:1373, 2004.

Bacterial Stripe of Hog Millet Caused by Acidovorax avenae subsp. avenae, a New Disease in Korea.

In July 2011, bacterial stripe was observed on a commercial field of hog millet (Panicum miliaceum L.) in Chuncheon, Korea, with a disease incidence of 37% in the field. Symptoms on leaves included reddish-brown, long, narrow stripes that varied in length and were sharply delineated by uninfected adjacent vascular bundles. Eleven bacterial isolates (BC3107, BC3214 to BC3223) were recovered on trypticase soy agar from lesions surface sterilized in 70% ethanol for 1 min. The isolates, all obtained from different plants, were gram negative, oxidase positive, aerobic rods with two to four flagella. The isolates produced circular, cream-colored, nonfluorescent, butyrous colonies with entire margins on King's B medium. Using the Biolog Microbial Identification System, Version 4.2 (Biolog Inc., Hayward, CA), the isolates were identified as Acidovorax avenae subsp. avenae with Biolog similarity indices ranging from 0.52 to 0.72 after 24 hr. Characters for differentiating between Acidovorax spp. were tested according to Schaad et al. (2). The isolates were positive for gelatin liquefaction, nitrate reduction, lipase production, utilization of D-mannitol, sodium citrate, and alkaline in litmus milk. The isolates were negative for utilization of D-arabitol and did not amplify with PCR primer sets Aaaf5, Aaaf3/Aaar2, and Aacf2/Aacr2. Colonies were V-, V+, and V+ for utilization of D-fucose, maltose, and ethanol, respectively. Regions of the 16S rRNA (rrs) and the IGS were sequenced to aid in the identification of the isolates using reported PCR primer sets (1,4). A 1,426 bp fragment of the rrs region shared 100% similarity with all strains of A. avenae available in GenBank. Pathogenicity tests were separately performed for the 11 isolates in different greenhouses located in Suwon (National Academy of Agricultural Science), and Chuncheon (Gangwondo Agricultural Research and Extension Services) in Korea. Pathogenicity was confirmed by clip inoculation with sterilized scissors dipped into cell suspensions containing 105 CFU/ml on three 8-day-old leaves of hog millet (two plants per isolate), rice (Oryza sativa L. cv. Hopyeong), and sweet corn (Zea mays L. cv. Daehak) in a greenhouse maintained at 28 to 32°C and 90% relative humidity. The isolates induced similar symptoms as those originally observed on hog millet 5 days after inoculation. No symptoms were observed on the control plants (hog millet, rice, and sweet corn), which were clipped with scissors dipped in sterilized distilled water. The identity of bacteria reisolated from the stripes on inoculated leaves was confirmed by analyzing sequences of the 16S-23S rRNA intergenic spacer region (IGS) (1). On the basis of physiological, pathological, and sequence data, the isolates were identified as A. avenae subsp. avenae. To our knowledge, this is the first report of bacterial stripe of hog millet caused by A. avenae subsp. avenae in Korea. The spread of the bacterial disease is expected to have a significant economic impact on hog millet culture in the fields of Gangwon Province in Korea. Nucleotide sequence data reported are available under accession numbers JQ743877 to JQ743887 for rrs of BC 3207 and BC3214 to BC3223, and JQ743877 to JQ743887 for IGS of BC3207 and BC3214 to BC3223. References: (1) T. Barry et al. The PCR Methods Appl. 1:51, 1991. (2) N. W. Schaad et al. Syst, Appl. Microbiol. 31: 434, 2008. (3) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011. (4) W. G. Weisburg et al. J. Bacteriol. 173: 697, 1991.

Bacterial Leaf Spot of Zinnia Caused by Xanthomonas campestris pv. zinniae, a New Disease in Korea.

In September 2011, bacterial leaf spot was observed on zinnia plants (Zinnia elegans L.) grown in a garden in Suwon, Korea. Leaf symptoms included angular lesions that were yellow or brown-to-reddish brown in the center. Bacterial isolates (BC3293 to BC3299) were recovered on trypticase soy agar from lesions surface-sterilized in 70% ethyl alcohol for 1 min. Pathogenicity of the isolates was confirmed by spray inoculation with a bacterial suspension (106 CFU/ml) prepared in sterile distilled water and applied to zinnia plants at the four- to five-leaf growth stage (two plants per isolate). Sterile distilled water was used as the negative control. The inoculated plants were incubated in a greenhouse at 26 to 30°C and 95% relative humidity. Characteristic leaf spot symptoms developed on inoculated zinnia plants 5 days after inoculation. No symptoms were observed on the negative control plants. The bacterium reisolated from the inoculated leaves was confirmed through gyrB gene sequence analysis (3). All isolates were gram-negative, aerobic rods, each with a single flagellum. Isolates were positive for catalase and negative for oxidase. The biochemical and physiological tests for differentiation of Xanthomonas were performed using methods described by Shaad et al. (2). The isolates were positive for mucoid growth on yeast extract-dextrose-calcium carbonate agar, growth at 35°C, hydrolysis of starch and esculin, protein digestion, acid production from arabitol, and utilization of glycerol and melibiose. Colonies were negative for ice nucleation, and alkaline in litmus milk. The gyrB gene (870 bp) and the 16S-23S rRNA internal transcribed spacer (ITS) regions (884 bp) were sequenced to aid in identification of the original field isolates using published PCR primer sets Xgyr1BF/Xgyr1BR (3) and A1/B1 (1), respectively. Sequence of the gyrB gene (GenBank Accession Nos. JQ665732 to JQ665738) from the zinnia field isolates shared 100% sequence identity with the reference strain of Xanthomonas campestris pv. zinniae (GenBank Accession No. EU285210), and the ITS sequences (GenBank Accession Nos. JQ665725 to JQ665731) had 99.9% sequence identity with X. campestris pv. zinnia XCZ-1 (GenBank Accession No. EF514223). On the basis of the pathogenicity assays, biochemical and physiological tests, and sequence analyses, the isolates were identified as X. campestris pv. zinniae. To our knowledge, this is the first report of bacterial leaf spot of zinnia caused by X. campestris pv. zinniae in Korea. The disease is expected to result in economic and aesthetic losses to plants in Korean landscapes. Thus, seed treatment with bactericides will be required to control the bacterial leaf spot of zinnia before planting. References: (1) T. Barry et al. The PCR Methods Appl. 1:51, 1991. (2) N. W. Schaad et al. Page 189 in: Laboratory Guide for Identification of Plant Pathogenic Bacteria. 3rd ed. N. W. Schaad et al., eds. The American Phytopathological Society, St. Paul, MN, 2001. (3) J. M. Young et al. Syst. Appl. Microbiol. 31:366, 2008.

Prognostic factors for idiopathic pulmonary fibrosis: clinical, physiologic, pathologic, and molecular aspects.

BACKGROUND: Previous studies identified clinical and physiologic factors of idiopathic pulmonary fibrosis (IPF) that are related to an increased risk of mortality. But there are few studies about histologic and molecular approach. OBJECTIVE: We investigated whether the C-reactive protein (CRP), fibroblastic foci, phosphorylated Smad2/3 (p-Smad2/3), tumor growth factor-beta (TGF-beta), TGF-beta receptor II (TbetaRII), and the polymorphism of the TGF-beta1 codon 10 are associated with the progression of IPF patients. DESIGN: Eighty-six IPF patients who underwent surgical lung biopsies were examined. For each patient, clinical and physiologic parameters were investigated, and we performed immunohistochemical staining for p-Smad2/3 and TbetaRII, and genotyping of the TGF-beta1 codon 10 polymorphism. RESULTS: Age at diagnosis, gender, symptom duration, and smoking status did not show a significant association. However, the amount of smoking (p = 0.002), severe reduction in the percentages of predicted forced vital capacity (p = 0.013) and diffusion lung capacity of carbon monoxide (p = 0.023), CRP (p = 0.009) at diagnosis, and fibroblastic foci (p = 0.026) were associated with a poor prognosis. Cellularity, fibrosis, expression level of p-Smad2/3 and TbetaRII, and genotype of the TGF-beta1 codon 10 polymorphism did not have a statistically significant association with the prognosis. CONCLUSION: This study confirmed the amount of smoking, abrupt decrease in follow-up pulmonary function parameters, fibroblastic foci, and increased levels of CRP concentration at diagnosis were significantly associated with poor survival. Larger studies are required to confirm all prognostic factors including CRP.

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.

Bacterial Leaf Spot of Onion Caused by Pseudomonas syringae pv. porri, a New Disease in Korea.

In April 2007, a bacterial leaf spot of onion (Allium cepa L.) was observed in fields of Namjeju, Jeju Province in Korea with incidence varying from 95 to 100%. Symptoms on leaves included leaf blight and white and brown spots on the leaf surface. Eight bacterial isolates were recovered on trypticase soy agar (TSA) from leaf spot and blight lesions that were surface sterilized in 70% ethanol for 1 min. The isolates were fluorescent on King's B agar and gram-negative, aerobic rods with one to three polar flagella. All isolates belonged to P. syringae (LOPAT) group Ia (+, -, -, -, +) (1). The gyrB, rpoD (2), and rpoB regions (4) of the isolates and reference strain Pseudomonas syringae pv. porri CFBP 1908PT (=BC2583) were partially sequenced using reported primers (2,4). The rpoB region (1,119 bp) of the isolates (GenBank Accession Nos. JF719311-JF719318 for rpoB) shared 100% identity with P. syringae pv. porri CFBP 1908PT (GenBank Accession No. JF719319). Phylogenetic analysis based on partial sequences of the gyrB (660 bp) and rpoD (590 bp) loci of Pseudomonas spp. available in the GenBank (2,4), the reference strain P. syringae pv. porri CFBP 1908PT, and the field isolates was conducted using Jukes-Cantor model in MEGA Version 4.1 (3). The isolates and reference strain P. syringae. pv. porri CFBP 1908PT clustered in one group (GenBank Accession Nos. JF719293-JF719300 for gyrB; JF719302-JF719309 for rpoD). On the basis of phenotypic and pathological characteristics and the sequences, the eight isolates were identified as P. syringae pv. porri. Pathogenicity was evaluated on 3-week-old onion plants (cv. Marushino 330) by spot and spray inoculation. Bacteria were grown on TSA for 24 h at 28°C. Five microliters of bacterial suspension in sterile distilled water (1 × 106 CFU/ml) were spot inoculated on pinpricked positions of five leaves for each isolate and incubated in humid plastic boxes at 27°C. Spot-inoculated surfaces turned white 2 days after inoculation, followed by brownish discoloration. A bacterial suspension in sterile distilled water (100 ml at 1 × 106 CFU/ml) was sprayed onto three plants for each isolate. Plants were maintained in a greenhouse at 18 to 27°C and 80% relative humidity. Isolates induced identical symptoms on all inoculated plants 2 weeks after spray inoculation as those originally observed on onion in the fields. Bacteria were reisolated 3 weeks after inoculation from diseased lesions surface sterilized in 70% ethanol for 1 min and the identity of the reisolated bacteria confirmed by analyzing the sequences of rpoD gene (2). No symptoms were noted on intact plants inoculated with sterilized distilled water. To our knowledge, this is the first report of bacterial leaf spot of onion caused by P. syringae pv. porri in Korea. The disease is expected to have a significant economic impact on onion culture in the fields of Jeju Province in Korea. References: (1) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (2) H. Sawada et al. J. Mol. Evol. 49:627, 1999. (3) K. Tamura et al. Mol. Biol. Evol. 24:1596, 2007. (4) L. Tayeb et al. Res. Microbiol. 156:763, 2005.

A New Disease, Bacterial Leaf Spot of Rape, Caused by Atypical Pseudomonas viridiflava in South Korea.

In March 2007, a bacterial leaf spot of rape (Brassica napus var. oleifera) was observed in fields near Seogwipo City, Jeju Province, South Korea. Symptoms on leaves included white and corky-brown spots and sometimes water-soaked spots on the lower leaf surface. Seven bacterial isolates (BC2495-BC2497 and BC2506-BC2509) were recovered on trypticase soy agar (TSA) from leaf spot lesions surface sterilized in 70% ethyl alcohol for 1 min. Isolates were gram-negative, aerobic rods with one to three flagella. Pathogenicity was evaluated on 2-week-old rape plants by spot and spray inoculation. Bacteria were grown on TSA for 48 h at 25°C. Five microliters of bacterial suspension in sterile distilled water (1 × 105 CFU/ml) were spot inoculated on pinpricked positions of five detached leaves for each isolate. The detached leaves were incubated in a plastic box with high humidity at 20°C. Spot-inoculated surfaces turned white 48 h after inoculation followed by a brownish discoloration. A bacterial suspension in sterile distilled water (100 ml at 1 × 105 CFU/ml) was sprayed onto three plants for each isolate. Plants were maintained in a growth chamber at 20°C and 90% relative humidity. Isolates induced identical symptoms 2 weeks after spray inoculation as those originally observed on rape in the fields. Bacteria were reisolated 18 days after inoculation from diseased lesions surface sterilized in 70% ethyl alcohol for 1 min. Pathogenicity of the reisolated bacteria was confirmed by spot inoculation as described above. No symptoms were noted on detached leaves and intact plants inoculated with sterilized distilled water. Using the Biolog Microbial Identification System, Version 4.2 (Biolog Inc., Hayward, CA), the isolates were identified as Pseudomonas viridiflava with a Biolog similarity index range of 0.52 to 0.72 after 24 h. Results of LOPAT tests (2) of isolates were identical to that of atypical P. viridiflava reported by Gonzalez et al. (1). Levan production and pectolytic activity of the isolates were variable. All isolates were positive for tobacco hypersensitivity and negative for oxidase reaction and arginine dihydrolase production. The 16S rDNA region (1,442 bp) of the isolates (GenBank Accession Nos. HM190218-HM190224; P. viridiflava CFBP2107T = HM190229), amplified by using universal PCR primers, shared 100% sequence identity with atypical P. viridiflava (GenBank Accession No. AM182934) (1). The gyrB sequence (638 bp) from the isolates (GenBank Accession Nos. HM190232-HM190238; P. viridiflava CFBP2107T = HM190239), amplified by using previously reported PCR primers (3), had a distance index value range of 0.029 to 0.031 with that of the P. viridiflava CFBP2107T (=BC2597) as determined by Jukes-Cantor model using MEGA Version 4.1 (4). On the basis of phenotypic characteristics and the sequences, the seven isolates were identified as atypical P. viridiflava. The disease is named "bacterial leaf spot". To our knowledge, this is the first report of bacterial leaf spot of rape caused by atypical P. viridiflava. References: (1) A. J. Gonzalez et al. Appl. Environ. Microbiol. 69:2936, 2003. (2) R. A. Lelliott et al. J. Appl. Bacteriol. 29:470, 1966. (3) H. Sawada et al. J. Mol. Evol. 49:627, 1999. (4) K. Tamura et al. Mol. Biol. Evol. 24:1596, 2007.

A New Disease, Arboricola Leaf Spot of Bell Pepper, Caused by Xanthomonas arboricola.

In June 2007, a leaf spot disease was observed on seedlings of bell pepper (Capsicum annuum L. var. angulosum) in a commercial greenhouse in Iksan City, Korea. Symptoms on leaves included small, irregularly shaped, brown lesions with yellow halos and marginal necrosis. Four bacterial isolates, BC2526, BC2527, BC2528, and BC2529, were obtained from the diseased plants. The isolates were gram-negative aerobic rods with a single flagellum. On peptone sucrose agar, colonies were yellow and raised with smooth margins. Pathogenicity was confirmed by spraying cell suspensions containing 106 CFU/ml onto seedlings of bell pepper (cv. Fieste), tomato (Solanum lycopersicon cv. Seokwang), and hot pepper (Capsicum annuum cv. Daekwang) in a greenhouse maintained at 26 ± 3°C. The isolates induced symptoms, spots, and margin blights on leaves of bell pepper, tomato, and hot pepper 2 weeks after inoculation. No symptoms were noted on the control plants inoculated with sterilized distilled water. The identity of the bacteria was confirmed with the Biolog Microbial Identification System, version 4.2 (Biolog Inc., Hayward, CA). The gyrB region was partially sequenced to aid in identification of four isolates using PCR primers reported by Parkinson et al. (1). A 701-bp fragment of the gyrB region from the isolates was compared with sequences of the reference strains of Xanthomonas available in the DDBL/EMBL/GenBank databases (4). The bacterial isolates clustered with Xanthomonas arboricola pathovars in a phylogenetic tree generated with the neighbor-joining method in MEGA (version 4.1) (3). The sequence of the gyrB from the isolates had distance indexes of 0.016, 0.014, 0.016, 0.013, 0.037, and 0.019 as determined by the Jukes-Cantor model (2) with sequences of the reference strains of X. arboricola pvs. pruni (EU498953), celebensis (EU498984), corylina (EU499002), juglandis (EU 498951), populi (EU 499035), and a X. arboricola strain from bell pepper (EU 499039) (4), respectively. To our knowledge, this is the first report of a leaf disease on bell pepper caused by X. arboricola. We propose the name arboricola leaf spot for the disease. Further studies are required for determining pathovar status of the strain. Nucleotide sequence data reported are available under Accession Nos. GQ502678, GQ502679, GQ502680, and GQ502681 for gyrB of BC2626, BC2527, BC2528, and BC2923, respectively. The disease is expected to have a significant economic impact on tomato and pepper production in Korea. References: (1) N. Parkinson et al. Int. J. Syst. Evol. Microbiol. 59:264, 2009. (2) N. Saitou and M. Nei. Mol. Biol. Evol. 4:406, 1987. (3) K. Tamura et al. Mol. Biol. Evol. 24:1596, 2007. (4) J. M. Young et al. Syst. Appl. Microbiol. 31:366, 2008.

Bacterial Leaf Spot of Iceberg Lettuce Caused by Xanthomonas campestris pv. vitians Type B, a New Disease in South Korea.

In 2008 and 2009, a leaf spot of iceberg lettuce (Lactuca sativa var. capitata) was observed in two fields of Pyeongchang District and Jecheon City in South Korea, respectively. Disease incidence averaged 3.5% in the two fields. Symptoms on leaves included black, water-soaked, angular lesions with halos. Two bacterial isolates, BC2932 and BC3095, were recovered on trypticase soy agar (TSA) from lesions surface sterilized in 70% ethyl alcohol for 1 min. Both isolates had gram-negative, aerobic rods each with a single flagellum. Colonies on peptone sucrose agar were yellow and raised with smooth margins. Pathogenicity was evaluated on 3-week-old lettuce plants (cv. Avi). Bacteria were grown on TSA for 48 h at 28°C. A bacterial suspension in sterile distilled water (100 ml at 1 × 105 CFU/ml) was sprayed onto three plants for each isolate. Plants were maintained in a growth chamber at 28°C and 90% relative humidity. Isolates induced identical symptoms 3 days after inoculation as those originally observed in the fields. Pathogenicity of bacteria reisolated 10 days after inoculation from lesions surface sterilized in 70% ethyl alcohol was confirmed by inoculation as described above. No symptoms were observed on two control plants treated with sterile distilled water. Identity of bacteria reisolated from inoculated leaves was confirmed by PCR with specific primer set B162 (1). DNA of the original two isolates and 12 reisolates (two per inoculated plant) was amplified by PCR assay using Xanthomonas campestris pv. vitians Type B LMG938 (= BC2575) as a positive control treatment and X. axonopodis pv. vitians strain CFBP2538 (= BC2610) as a negative control treatment. The PCR amplicon for each of the 14 test isolates was identical in size to that of X. campestris pv. vitians Type B LMG938. No fragment of X. axonopodis pv. vitians CFBP2538 was amplified. Patterns of metabolic fingerprinting of the original two isolates were more similar to those of X. campestris pv. vitians Type B LMG938 than X. axonopodis pv. vitians CFBP2538 using Biolog Microbial Identification System Version 4.2 (Biolog Inc., Hayward, CA). X. campestris pv. vitians Type B LMG938, BC2932, and BC3095 were identified as X. campestris pv. pelargonii with a Biolog similarity index of 0.68, 0.45, and 0.78, respectively. Strain X. axonopodis pv. vitians CFBP2538 was identified as X. campestris pv. juglandis with an index of 0.48. The dnaK (958 bp), gyrB (859 bp), and rpoD (884 bp) regions were partially sequenced to aid in identification of the two original field isolates as well as X. campestris pv. vitians Type B LMG 938 and X. axonopodis pv. vitians CFBP2538 using reported PCR primers (3). Sequences were compared with those of reference strains of Xanthomonas in GenBank. Sequences of the three genes from the two lettuce field isolates shared 100% similarity to those of the genes of X. campestris pv. vitians Type B LMG938 and had a distance index value of 0.040, 0.099, and 0.046, respectively, with the reference strain of X. axonopodis pv. vitians CFBP2538 determined by p-distance modeling using MEGA Version 4.1 (2). Based on the pathogenicity test and sequence analyses, the isolates were identified as X. campestris pv. vitians Type B. To our knowledge, this is the first report of bacterial leaf spot of iceberg lettuce caused by X. campestris pv. vitians Type B in South Korea. References: (1) J. D. Barak et al. Plant Dis. 85:169, 2001. (2) K. Tamura et al. Mol. Biol. Evol. 24:1596, 2007. (3) J. M. Young et al. Syst. Appl. Microbiol. 31:366, 2008.

Involvement of cyclic GMP in nitric-oxide-induced gastric relaxation Comparison of the actions of cyclic GMP and cyclic AMP.

BACKGROUND: Smooth muscle relaxation induced by various agents that increase the cellular levels of cyclic nucleotides (cAMP and cGMP) is accompanied by a decrease in intracellular Ca2+ concentration. However, little is known about the differences between the inhibitory effects of cAMP and cGMP on the contraction of smooth muscle. OBJECTIVE: To compare the effects and underlying mechanisms of cAMP and cGMP on the inhibition of gastric smooth muscle contraction, cyclic nucleotide promoting agents, as well as cell membrane permeable cyclic nucleotides were used. METHODS: Isometric contraction was measured from circular muscle strips prepared from the fundus of cat stomach in a cylinder-shaped chamber filled with Krebs-Ringer solution (pH 7.4, temperature 36 degrees C) bubbled with 5% CO2 in O2. The level of inositol phosphates (IPs) was measured. RESULTS: Forskolin and sodium nitroprusside significantly inhibited acetylcholine (ACh)-induced gastric smooth muscle contraction and increased the cellular levels of cAMP and cGMP, respectively. Direct application of 8-Br-cAMP and 8-Br-cGMP also significantly inhibited ACh-induced contraction. Both verapamil and TMB-8 inhibited ACh-induced contraction. The combined inhibitory effect of verapamil and TMB-8 was significantly greater than the effect of either one, separately. Forskolin or sodium nitroprusside similarly augmented the effect of verapamil. However, the inhibitory effect of TMB-8 was augmented only by 8-Br-cGMP or sodium nitroprusside but not by 8-BrcAMP or forskolin. Forskolin and 8-Br-cAMP significantly inhibited the formation of inositol phosphates stimulated by ACh. CONCLUSIONS: cAMP inhibits the contraction mechanism associated with intracellular Ca2+ mobilization as well as extracellular Ca2+ influx, while cGMP inhibits contraction by inhibiting the mechanism associated with extracellular Ca2+ influx.

In vitro and in vivo studies of PEO-grafted blood-contacting cardiovascular prostheses.

The initial step of thrombus formation on blood-contacting biomaterials is known to be adsorption of blood proteins followed by platelet adhesion. Poly(ethylene oxide) (PEO) has been frequently used to modify biomaterial surfaces to minimize or prevent protein adsorption and cell adhesion. PEO was grafted onto a number of biomaterials in our laboratory. Nitinol stents and glass tubes were grafted with PEO by priming the metal surface with trichlorovinylsilane (TCVS) followed by adsorption of Pluronic and y-irradiation. Nitinol stents were also coated with Carbothane for PEO grafting. Chemically inert polymeric biomaterials, such as Carbothane, polyethylene, silicone rubber, and expanded polytetrafluoroethylene (e-PTFE), were first adsorbed with PEO-polybutadiene-PEO (PEO-PB-PEO) triblock copolymers and then exposed to gamma-irradiation for covalent grafting. For PEO grafting to Dacron (polyethylene terephthalate), the surface was sequentially treated with PEO-PB-PEO and Pluronics followed by gamma-irradiation. In vitro studies showed substantial reduction in fibrinogen adsorption and platelet adhesion to the PEO-grafted surfaces compared with control surfaces. Fibrinogen adsorption was reduced by 70-95% by PEO grafting on all surfaces, except for e-PTFE. The platelet adhesion corresponded to the fibrinogen adsorption. When the PEO-grafted surfaces were tested ex vivo/in vivo, however, the expected beneficial effect of PEO grafting was inconsistent. The beneficial effect of the PEO grafting was most pronounced on the PEO-grafted nitinol stents. Thrombus formation was reduced by more than 85% by PEO grafting on metallic stents. Only moderate improvement (i.e. 35% decrease in platelet deposition) was observed with PEO-grafted tubes of polyethylene, silicone rubber, and glass. For PEO-grafted heart valves made of Dacron, however, no effect of PEO grafting was observed at all. It appears that the extent of thrombus formation on PEO-grafted biomaterials was directly related to the extent of tissue damage during implantation surgery. Platelets can be activated and form aggregates in the bulk blood, and the formed platelet aggregates may be able to deposit on the PEO monolayer overcoming its repulsive property. Our studies indicate that the testing of in vitro platelet adhesion should include adhesion of large platelet aggregates, in addition to adhesion of individual platelets. Furthermore, the surface modification methods should be improved over the current monolayer grafting concept so that the repulsive force by the grafted PEO layers is large enough to prevent adhesion of platelet aggregates formed in the bulk blood before arriving at the biomaterial surface.

Grafting of PEO to glass, nitinol, and pyrolytic carbon surfaces by gamma irradiation.

Glass, nitinol, and pyrolytic carbon surfaces were grafted with poly (ethylene oxide) (PEO) and PEO-containing Pluronic surfactants by gamma irradiation. These substrates were coated with a primer layer of trichlorovinylsilane (TCVS), which allows grafting of organic polymers. The TCVS-coated substrates were adsorbed with PEO or Pluronics and exposed to 0.3 Mrad of gamma radiation to graft the polymer to the surface. PEO-grafted substrates were characterized by contact angle measurement, X-ray photoelectron spectroscopy, fibrinogen adsorption, and platelet adhesion and activation. Surface modification with PEO reduced fibrinogen adsorption by as much as 99%. Platelet adhesion was significnatly reduced or prevented on the modified surfaces. Protein- and platelet-resistance effects were independent of hydrophilicity of the PEO-grafted surfaces. Polymer grafting by gamma radiation to TCVS-coated substrates provides a facile process to improve thromboresistance of inorganic biomaterials.