First Report of Bursaphelenchus thailandae on Pinus densiflora in Korea

A survey of nematodes on Pinus densiflora in Namyangju City, Gyeonggi Province, Korea was conducted in 2008. Namyangju is located in an area with pine wilt caused by Bursaphelenchus xylophilus and monitoring of wilt has been conducted periodically. Nematodes were extracted from wood chips by the Baermann's funnel method and were cultured on a medium of Botrytis cinerea. During the survey, B. xylophilus and B. thailandae were detected. B. thailandae was found in 20% of the trees tested and usually was found alone without B. xylophilus. Population density of B. thailandae ranged from 8,000 to 15,000 nematodes per 100 g of wood chips. The species was identified by morphology and molecular characterization. B. thailandae was differentiated from B. xylophilus by slight swellings of the stylet knobs, protruding vulval flaps and pointed tail in females, and the male spicule with distinctive shading in the dorsal region. Morphometric data was obtained by measurements of 20 females and 10 males: female, body length = 951.3 ± 56.6 μm, a = 31.8 ± 1.9, b = 10.8 ± 0.9, c = 23.4. ± 0.8, V = 76.2 ± 0.8, stylet length = 14.5 ± 0.6 μm, length of postuterine sac = 90.3 ± 13.5 μm; male, body length = 838.0 ± 71.5 μm, a = 31.1 ± 2.1, b = 5.2 ± 0.5, c = 30.4 ± 2.7, stylet length = 13.5 ± 1.1 μm, spicules length = 16.5 ± 0.7 μm. Measurements were compared with the original description of B. thailandae reported by Braasch and Braasch-Bidasak (1), which showed that the Korean isolate was larger in most body sizes. For molecular diagnosis, the internal transcribed spacer (ITS) and D2-D3 rDNA were amplified by PCR (US/PTC-0220; Bio Rad, Hercules, CA). The sequences of ITS and D2-D3 rDNA of B. thailandae from P. densiflora showed 98 and 99% homology to those of B. thailandae from GenBank Accession Nos. AM157746 and DQ497184, respectively. B. thailandae was originally described on Pinus merkusi in Pai, North Thailand (1) while Ningbo Entry-Exit Inspection and Quarantine Bureau in China reported a detection of B. thailandae in the imported packaging wood from Hong Kong, Japan, Korea, Italy, and the United States (2). However, packaging wood is a circulating product and the establishment of B. thailandae in those countries is not confirmed. The pathogenicity of B. thailandae on coniferous trees remains to be determined. To our knowledge, this is the first report of B. thailandae on P. densiflora in a natural area in Korea. References: (1) H. Braasch and R. Braasch-Bidasak. Nematology 4:853, 2002. (2) J. Gu et al. For. Pathol. 36:323, 2006.

The fungal product terreic acid is a covalent inhibitor of the bacterial cell wall biosynthetic enzyme UDP-N-acetylglucosamine 1-carboxyvinyltransferase (MurA)

Terreic acid is a metabolite with antibiotic properties produced by the fungus Aspergillus terreus. We found that terreic acid is a covalent inhibitor of the bacterial cell wall biosynthetic enzyme MurA from Enterobacter cloacae and Escherichia coli in vitro. The crystal structure of the MurA dead-end complex with terreic acid revealed that the quinine ring is covalently attached to the thiol group of Cys115, the molecular target of the antibiotic fosfomycin. Kinetic characterization established that the inactivation requires the presence of substrate UNAG (UDP-N-acetylglucosamine), proceeding with an inactivation rate constant k(inact) of 130 M(-1) s(-1). Although the mechanisms of inactivation are similar, fosfomycin is approximately 50 times more potent than terreic acid, and the structural consequences of covalent modification by these two inhibitors are fundamentally different. The MurA-fosfomycin complex exists in the closed enzyme conformation, with the Cys115-fosfomycin adduct buried in the active site. In contrast, the dead-end complex with terreic acid is open, is free of UNAG, and has the Cys115-terreic acid adduct solvent-exposed. It appears that terreic acid reacts with Cys115 in the closed, binary state of the enzyme, but that the resulting Cys115-terreic acid adduct imposes steric clashes in the active site. As a consequence, the loop containing Cys115 rearranges, the enzyme opens, and UNAG is released. The differential kinetic and structural characteristics of MurA inactivation by terreic acid and fosfomycin reflect the importance of noncovalent binding potential, even for covalent inhibitors, in ensuring inactivation efficiency and specificity.

Neoadjuvant Intratumoral Injection of Dendritic Cells in Breast Cancer

Backround: Autologous intratumoral dendritic cell injections were used to modulate the tumor reduction effects of standard neoadjuvant chemotherapy. Dendritic cells are important in the regulation of T cell immunity and have been shown to have activity in cancer patients. The neoadjuavant combination therapy was designed to expose dendritic cells to tumor cell apoptosis leading to induction of tumor antigen-specific responses.Methods: Seventeen women with stage II or III breast cancer with breast tumors at least 3 cm in size and had a confirmed initial breast biopsy were entered into this trial from August 2007 through 2009. All patients participating in the clinical trial had tumors that expressed either carcinoembryonic antigen (CEA) or survivin and were HER2-neu negative. They received 4 cycles of paclitaxel at 175 mg/m2 followed by 4 cycles of doxorubicin 60 mg/m2 and cyclophosphamide 600 mg/m2 (AC) in a bi-weekly dose dense fashion. Pegfilgrastim 6 mg subcutaneous injection was administered 24 hours after each cycle of chemotherapy. Autologous intratumoral dendritic cell injections were administered one week following the first three paclitaxel treatments. All patients consented to a pre-treatment biopsy and a second tumor biopsy after 4 cycles of paclitaxel to evaluate responses to the intratumoral dendritic cell injections. The endpoints of this trial included assessment of clinical and pathologic response in the breast, safety of the intratumoral dendritic cell injection, evaluation of tumor response, and induction of T cell responses to tumor antigens.Results: Fourteen patients are evaluable for response. The median age was 51.5, the median tumor size was 5.6 cm, and 64 % were estrogen receptor positive. A complete clinical response was observed in 57%, a partial response in 36%, and one stable disease response. A pathologic complete response with no evidence of tumor in the breast was confirmed in 2 patients (14 %). Treatment was well tolerated with no incidence of toxicity observed related to the intratumoral dendritic cell injections. Grade 3/4 hematologic toxicity was as expected for the chemotherapy. Other grade 3/4 toxicity related to the chemotherapy included fatigue, hand-foot, infection, mucositis, and hypocalcemia.Discussion: Combination neoadjuvant therapy with dose-dense paclitaxel followed by AC and autologous intratumoral dendritic cell injections administered between the first three cycles of paclitaxel is safe with no toxicity observed related to the intratumoral dendritic cell injections. Immune response to the treatment is being evaluated by proliferation and interferon-gamma production by peripheral blood mononuclear cells in response to tumor cell lysates, survivin, and CEA. Initial evaluation indicates that treatment resulted in generation of tumor specific responses in more than half of all treated patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4128.

First Report of Bursaphelenchus pinophilus on Korean pine (Pinus koraiensis)

The genus Bursaphelenchus Fuchs, 1937 contains approximately 90 species (3) that are morphologically similar. Pine wood nematode, Bursaphelenchus xylophilus (4) Nickle, 1970, is the causal organism of pine wilt disease and accurate identification is essential for diagnosis of the disease. In Korea, pine wilt disease was first reported in 1988 and devastated 6,800 ha of pine forest through 2008. For a survey of trees with pine wilt disease, wood samples were taken randomly from dead Pinus koraiensis in Namyangju, Gyeonggi Province in Korea. The extracted nematodes from dead trees were maintained in culture on Botrytis cinerea and morphological characteristics were observed with an inverted light microscope (Leica DE/DMI 3000B). Identification of Bursaphelenchus spp. based on morphological characteristics is difficult, especially for identification of juveniles that carry few morphological features for species identification. The internal transcribed spacer (ITS) region in ribosomal DNA provides useful molecular diagnostic markers for this genus (1). The nematodes were provisionally identified as Bursaphelenchus pinophilus based on the characteristic long and arcuate body shape, male spicule with distinctive rostrum and small cucullus, female vulval flap, and mucronate conical tail. Other Bursaphelenchus spp. with vulval flaps and spicules with cucullus are B. xylophius, B. mucronatus, B. abruptus, and B. pinophilus. For molecular diagnosis, DNA was extracted from more than 30 individual nematodes with a DNeasy Kit (Qiagen, Valencia, CA) and ITS regions 1, 2, and 5.8S in rDNA were amplified by PCR (US/PTC-0220; Bio Rad, Hercules, CA). The ITS-restriction fragment length polymorphism pattern was consistent with that of B. pinophilus (2). The ITS rDNA sequence of B. pinophilus from Korean pines had a 98% sequence homology to that of B. pinophilus in GenBank (Accession No. AM160664). The pathogenicity of B. pinophilus has not been determined. To our knowledge, this is the first report of B. pinophilus on P. koraiensis, but it was previously reported from Poland, Germany, and Portugal on P. sylvestris and P. pinaster (1). References: (1) H. Braasch. EPPO Bull. 31:127, 2001. (2) W. Burgermeister et al. Russ. J. Nematol. 13:29, 2005. (3) R. Sriwati et al. Nematology 10:1, 2008. (4) G. Steiner and E. M. Buhrer. J. Agric. Res. 48:946, 1934.

First Report of Bursaphelenchus doui on Tulip Tree (Liriodendron tulipifera) in Korea

Tulip tree (Liriodendron tulipifera) is one the major tree species in Korean plantations, but it originated from North America. Bursaphelenchus doui was collected from the wood of dead tulip trees located at Wanju in Chonnam Province, Korea. Nematodes were maintained in fungal medium culture (Botrytis cinerae) on potato dextrose agar. B. doui is morphologically close to B. xylophilus, a causative organism of pine wilt disease, and identification to species is difficult. However, B. doui differs from the other species of the xyophilus group by the larger spicule (33.8 to 43.3 μm) (1). For accurate species identification, both morphology and molecular biological methods were applied. Morphological observations showed lip region 3.7 μm high and offset by a constriction, median bulb well developed, esophageal gland overlapping intestine dorsally, vulval flap present, tail terminus with distinct mucro. Males ventrally curved by fixation, spicules pared, and large with small, cucullus, oval-shaped bursa. Measurements of 20 females and 10 males (female; body length = 901.7 ± 60.5 μm, a = 34.3 ± 3.1, b = 10.4 ± 1.5, c = 23.0 ± 2.3, V = 77.1 ± 2.0, stylet length = 14.3 ± 0.4 μm, tail length = 39.5 ± 4.2 μm, length of postuterine sac = 104.6 ± 7.8: male; body length = 790.4 ± 40.6 μm, a = 34.4 ± 2.7, b = 10.8 ± 1.7, c = 22.7 ± 1.3, stylet length = 14.3 ± 0.3 μm, tail length = 34.8 ± 1.9 μm, spicules length = 39.5 ± 4.1 μm) were close to the original description of B. doui by Braasch et al. (1). For molecular diagnosis, DNA was extracted from more than 30 individual nematodes with a DNeasy Kit (Qiagen, Valencia, CA) and the internal transgenic spacers (ITS) 1, 2, and 5.8S regions in rDNA were amplified by PCR (US/PTC-0220; Bio Rad, Hercules, CA). ITS-restriction fragment length polymorphism (RFLP) can discriminate closely related species by using five different restriction enzymes (2). ITS-RFLP patterns obtained with these enzymes were the same as reported by Braasch et al. (1). B. doui previously has been detected in Korean wooden packages imported to China (1). However, most production of Korean wooden packages depends on imported coniferous trees from other countries. Although B. doui has been reported in Japanese red pine (Pinus densiflora) in Japan (3), the natural distribution of B. doui in Korea is unclear. On the basis of morphological and molecular biological information, we identify this nematode as B. doui. To our knowledge, this is the first report of B. doui on tulip tree and in a natural area in Korea. References: (1) H. Braasch et al. Russ. J. Nematol. 12:19, 2004. (2) W. Burgermeister et al. Russ. J. Nematol. 13:29, 2005. (3) N. Kanzaki et al. Nematology. 10:69, 2008.

Survivin knockdown by short hairpin RNA abrogates the growth of human hepatocellular carcinoma xenografts in nude mice

Abnormal high activation of survivin is involved in carcinogenesis of various types of cancer. Survivin has been shown to promote cell proliferation in human hepatocellular carcinoma (HCC). Survivin-targeting approaches have become a promising strategy for treating HCC. Here, we used a reporter system to screen effective survivin siRNA sequences. The effect of vector-based survivin short hairpin RNA (shRNA) on the malignant phenotype of HCC cells in vitro and in vivo was determined, and an adenovirus-mediated shRNA expression vector was developed to decrease survivin expression of the established HCC tumor in nude mice. In vitro study showed that stable survivin knockdown inhibited cancer cell proliferation, enhanced apoptotic susceptibility, arrested cell cycle in the G1 phase and resulted in apparent mitotic catastrophe. Moreover, cells stably expressing survivin shRNA showed decreased tumorigenicity in nude mice. An additional in vivo study showed that intratumoral injection of adenovirus-delivered survivin shRNA suppressed tumor growth by spontaneous apoptosis of cancer cells and significantly prolonged animal survival. In conclusion, we proved the therapeutic potential of survivin shRNA for the treatment of HCC. And our results indicated that adenovirus-delivered shRNA may serve as a novel therapeutic for HCC.

Fabrication of epitaxial nanostructured ferroelectrics and investigation of their domain structures

Nanostructured ferroelectrics are important objects for studies on ferroelectric size effects as well as for applications to memory devices with ultra-high memory density. In the present article, we introduce several approaches for the synthesis of confined ferroelectrics with sizes in and below the hundreds of nanometer range, including top-down processes like e-beam lithography, self-assembly methods like chemical solution deposition, and growth by pulsed laser deposition using stencil masks. Furthermore, the ferroelectric domain structure of part of these nanostructures is investigated by means of synchrotron X-ray diffraction, and its contribution to the ferroelectric properties is discussed.

Effect of valproic acid on body weight, food intake, physical activity and hormones: results of a randomized controlled trial

The objective of this study was to identify mechanisms through which valproic acid (VPA) causes weight gain. Healthy participants (N = 52) were randomized to VPA or placebo in a double-blind study. Energy intake (EI) was measured in the laboratory at lunch and dinner, and physical activity (PA) was measured with accelerometry. Glucose levels and hormones [Peptide YY(3-36), glucagon-like peptide-1 (GLP-1), leptin, ghrelin, insulin] that regulate EI were measured. Assessments occurred at baseline and week 3. Change from baseline was evaluated with mixed models (alpha = 0.05). Weight significantly increased in the VPA group (+0.49 kg), but not the placebo group. The VPA group increased fast food fats cravings and decreased glucose levels compared with placebo. Change in weight, EI and PA did not differ by group. Within group analyses indicated that the VPA group increased PA, hunger, binge eating, depression and GLP-1. VPA-associated weight gain is not likely due to changes in PA or the gut hormones studied. Although EI did not increase when measured after 3 weeks of treatment, VPA decreased glucose levels and increased motivation to eat; hence, EI might have increased in the short-term. Research testing VPA on short-term (1 week) EI, metabolism, and substrate partitioning is warranted.

Effect of calorie restriction on subjective ratings of appetite

BACKGROUND

Energy or calorie restriction (CR) has consistently been shown to produce weight loss and have beneficial health effects in numerous species, including primates and humans. Most individuals, however, are unable to sustain weight losses induced through reductions in energy intake, potentially due to increased hunger levels. The effects that prolonged CR has on subjective aspects of appetite have not been well studied. Thus, the present study tested the effect of 6 months of caloric restriction on appetite in healthy, overweight men and women.

METHODS

Forty-eight overweight men and women with a body mass index (BMI; kg m(-2)) between 25-29.9 took part in a 6-month study and were randomised into one of four groups: healthy diet (control); 25% CR; 12.5% CR plus exercise (12.5% increased energy expenditure; CR + EX); low-calorie diet [LCD; 3724 kJ day(-1) (890 kcal day(-1)) until 15% of initial body weight was lost, then maintenance]. Appetite markers (i.e. hunger, fullness, desire to eat, etc.) were assessed weekly during a fasting state.

RESULTS

Body weight was significantly reduced in all three energy-restricted groups (CR = -10.4 +/- 0.9%; CR + EX = -10.0 +/- 0.8%; and LCD = -13.9 +/-0.7%), indicating that participants were adherent to their energy restriction regimen, whereas the healthy diet control group remained weight stable (control = -1.0 +/- 1.1%). Despite these significant weight losses, appetite ratings of participants in the three energy-restricted groups at month 6 were similar to the weight stable control group.

CONCLUSIONS

CR regimens with low fat diets producing significant weight losses have similar effects on appetite markers over a 6-month time period compared to a weight stable control group.

The intravertebral cleft in benign vertebral compression fracture: the diagnostic performance of non-enhanced MRI and fat-suppressed contrast-enhanced MRI

We compared the diagnostic performance of non-enhanced MRI and fat-suppressed contrast-enhanced MRI (CEMRI) in diagnosing intravertebral clefts in benign vertebral compression fractures (VCFs). We retrospectively reviewed 99 consecutive patients who had undergone percutaneous vertebroplasty for VCFs. A cleft was defined as a signal void or hyperintense area on non-enhanced MRI (T(1) and T(2) weighted imaging) or as a hypointense area within a diffusely enhanced vertebra on CEMRI. A cleft was confirmed as a solid opacification on post-procedural radiographs. The interobserver reliability and MRI diagnostic performance were evaluated. The interobserver reliability of non-enhanced MRI was substantial (k _ 0.698) and the interobserver reliability of CEMRI was almost perfect (k _ 0.836). Post-procedural radiographs showed solid cleft opacification in 32 out of the 99 cases. The sensitivity and specificity of non-enhanced MRI were 0.72 and 0.82 (observer 1) and 0.63 and 0.87 (observer 2), respectively. The sensitivity and specificity of CEMRI were 0.94 and 0.63 (observer 1) and 0.85 and 0.60 (observer 2), respectively. The sensitivity of CEMRI was significantly higher than that of non-enhanced MRI, and the specificity of non-enhanced MRI was higher than that of CEMRI. CEMRI was highly reliable and sensitive, and non-enhanced MRI was specific for intravertebral clefts. Therefore, spine MRIs, including CEMRI, could provide useful information about intravertebral clefts before percutaneous vertebroplasty.

Structural basis of glyphosate resistance resulting from the double mutation Thr97 -> Ile and Pro101 -> Ser in 5-enolpyruvylshikimate-3-phosphate synthase from Escherichia coli

The shikimate pathway enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) is the target of the broad spectrum herbicide glyphosate. The genetic engineering of EPSPS led to the introduction of glyphosate-resistant crops worldwide. The genetically engineered corn lines NK603 and GA21 carry distinct EPSPS enzymes. CP4 EPSPS, expressed in NK603 corn and transgenic soybean, cotton, and canola, belongs to class II EPSPS, glyphosate-insensitive variants of this enzyme isolated from certain Gram-positive bacteria. GA21 corn, on the other hand, was created by point mutations of class I EPSPS, such as the enzymes from Zea mays or Escherichia coli, which are sensitive to low glyphosate concentrations. The structural basis of the glyphosate resistance resulting from these point mutations has remained obscure. We studied the kinetic and structural effects of the T97I/P101S double mutation, the molecular basis for GA21 corn, using EPSPS from E. coli. The T97I/P101S enzyme is essentially insensitive to glyphosate (K(i) = 2.4 mm) but maintains high affinity for the substrate phosphoenolpyruvate (PEP) (K(m) = 0.1 mm). The crystal structure at 1.7-A resolution revealed that the dual mutation causes a shift of residue Gly(96) toward the glyphosate binding site, impairing efficient binding of glyphosate, while the side chain of Ile(97) points away from the substrate binding site, facilitating PEP utilization. The single site T97I mutation renders the enzyme sensitive to glyphosate and causes a substantial decrease in the affinity for PEP. Thus, only the concomitant mutations of Thr(97) and Pro(101) induce the conformational changes necessary to produce catalytically efficient, glyphosate-resistant class I EPSPS.

Identification of a new HLA-A*11 allele, HLA-A*1135, by sequence-based typing in Korean individual

A novel human leukocyte antigen (HLA)-A allele has been identified in the cord blood of a Korean baby. New HLA-A*1135 allele was different from HLA-A*1131 by three nucleotide substitution at codon 142 (ATC-->ACC) and codon 163 (CGG-->ACG), resulting in two amino acid change, Ile 142 Thr and Arg 163 Thr.

Identification of a new HLA-DRB1*14 variant, HLA-DRB1*1478, in a Korean individual

We report the identification of novel allele HLA-DRB1*1478 that was found during routine high-resolution sequence-based typing of the cord blood unit in Korean population. The DRB1*1478 allele shows two nucleotide differences from DRB1*1463 in exon 2 at nucleotide position 344 (G-->T) and 345 (T-->G), resulting in an amino acid change, Gly86Val.

Absence of donor-derived zona pellucida protein C homolog in the inner perivitelline layer of Peking duck (Anas platyrhynchos)-Japanese quail (Coturnix coturnix japonica) chimeras (Duails)

Avian blastodermal cells at stage X are used to produce interspecies chimeras for heterogenous poultry reproduction. However, recipient-derived inner perivitelline layer (IPVL)-enclosed donor-derived ova may affect the efficiency of germline transmission via chimera. Among the proteins in the IPVL, zona pellucida protein C (ZPC) plays an important role in sperm-egg binding and inducing the acrosome reaction. In the present study, Peking duck blastodermal cells at stage X were transferred into subgerminal cavities of Japanese quail embryos at the same stage. Fourteen female duck-quail chimeras (duails) were hatched and raised to sexual maturity. After being screened by PCR, 3 duails were selected for examination of donor-derived ZPC. A total of 152 IPVL protein samples from the individual eggs laid by the 3 duails then underwent a preliminary examination for the presence of donor-derived ZPC by means of SDS-PAGE, periodic acid-Schiff staining, and Western blotting. A novel 35-kDa ZPC, not observed in quail but in duck, was found in the IPVL of the duails. Further analysis of peptide mass fingerprinting of Peking duck ZPC, Japanese quail ZPC, and the 35-kDa duail ZPC by matrix-assisted laser desorption-ionization reflectron time-of-flight mass spectrometry revealed that the novel ZPC was an isoform of quail ZPC. Moreover, comparison of N-terminal amino acid sequences of these 3 ZPC confirmed that the 35-kDa quail ZPC had more amino acids at the N terminus than did native quail ZPC, and none of the donor-derived ZPC was found in the duails. These findings suggest that it would be difficult to obtain donor-derived offspring by natural mating of interspecies chimeras.

First Report of Pine Wilt Disease on Pinus koraiensis in Korea

Pine wilt disease is one of the most important forest tree diseases, especially in the East Asian countries of Japan, China, and Korea. The causal agent, Bursaphelenchus xylophilus (3), is transmitted by the insect vectors, pine sawyer beetles (Monochamus spp.). The vectors mainly attack coniferous trees and the infected trees die within several weeks. In Korea, pine wilt disease was first reported in Busan City in 1988, and now, the damaged area covers 7,820 ha and more than 60 cities in Korea. The main host trees are Pinus densiflora and P. thunbergii, which are the most common pines distributed in Korea. In 2006, however, we found pine wilt disease in a forest of P. koraiensis located in Gwangju City in Gyeonggi Province. Symptoms were systemic and leaves turned brown or yellowish. Wood samples were collected from the affected trees, and nematodes were extracted by a modified Baermann's funnel method. After 24 h, nematodes were collected from wood chips, and morphology was observed with an inverted light microscope (Leica DE/DMI 3000B, Wetzlar, Germany). Morphology was characterized by a typical Aphelenchoid-type esophagus, head constriction, female vulva flap, female tail, and a male spicule shape similar to B. xylophilus. For more accurate identification, DNA was extracted from individual nematodes with a DNeasy Kit (Qiagen, Valencia, CA). The internal transcribed spacers (ITS) 1 and 2 and 5.8S regions were amplified by PCR (1). Sequenced nucleotide information was compared with the sequences of B. xylophilus already reported in GenBank (Accession Nos. AB294736, AB277208, AM 157747, AY 347913, and BXU92464). ITS DNA sequences of the nematode from Korean pine was >99% identical to B. xylophilus in GenBank. The B. xylophilus from Korean pine tree was also successfully cultured in Botrytis cinerea medium and pathogenicity was tested from June to October 2007. More than 95% mortality was observed with the inoculation of 20 replicate 15-year-old trees of P. koraiensis and P. densiflora with 15,000 nematodes per tree. Therefore, we confirmed that pine wilt disease occurred in P. koraiensis in Korea. P. koraiensis is an endemic species in Korea and distribution is limited to the northern Korean Peninsula and some locations in Russia. It has been shown that P. koraiensis is susceptible to the pine wood nematode by an inoculation test in Japan (2); however, to our knowledge, this is the first report of pine wilt disease on P. koraiensis under field conditions in Korea. References: (1) W. K. Burgermeister et al. Russ. J. Nematol. 13:29, 2005. (2) K. Futai and T. Furuno. Bull. Kyoto Univ. For. 51:3, 1979. (3) G. Steiner and E. M. Buhrer. J. Agr. Res. 48:946, 1934.

First Report of the European Type of Bursaphelenchus mucronatus on Korean Pine (Pinus koraiensis) in Korea

More than 70 species of Bursaphelenchus have been reported and they are morphologically very similar. The pine wood nematode (Bursaphelenchus xylophilus) is a causal agent of pine wilt and accurate identification is essential for diagnosis of the disease. However, many other saprophytic nematodes are found in dead trees and some of them have high morphological similarity to B. xylophilus. B. mucronatus is commonly found in dead pine trees and is distinguished from B. xylophilus only by the presence of a distinct mucro in the female tail (3). However, natural populations of B. xylophilus show variation in tail morphology and some of them have a small lump on the end of the tail that looks like a short mucro, which could lead to misidentification. B. mucronatus has been reported to have two genotypes known as the East Asian type and the European type (2). The European type has a more rounded tail with a mucro, which is much more similar to B. xylophilus than the East Asian type. Molecular identification by internal transcribed spacer restriction fragment length polymorphism (ITS-RFLP) can distinguish these two genotypes clearly by using five different restriction enzymes (2). In Korea, we collected wood samples from dead Pinus koraiensis located at Pocheon, Gyeonggi Province in April, 2007 and nematodes were extracted by a modified Baermann funnel method. After 24 h, nematodes were collected and morphology was observed under an inverted light microscope (Leica DE/DMI 3000B, Wetzlar, Germany). Morphology was characterized by a typical Aphelenchoid-type esophagus, head constriction, female vulva flap, post uterine sac, female tail with mucro, and males with arched-shaped spicules. The tail was rounded with a long mucro >4 μm. For molecular diagnosis, DNA was extracted from single individual nematodes by using a DNeasy Kit (Qiagen, Valencia, CA) and the ITS 1 and 2 and 5.8S regions in rDNA were amplified by PCR (US/PTC-0220; Bio-Rad, Hercules, CA). ITS-RFLP patterns were analyzed and nucleotide sequences were compared with sequences of B. mucronatus already reported in GenBank (Accession Nos. AM179514, BMU93554, and DQ841162). The ITS-RFLP pattern of individuals matched the European type of B. mucronatus and was differentiated from the East Asian type by RsaI and HaeIII digestion (2). The ITS DNA sequence of nematodes from Korean pines was >98% identical to B. mucronatus in GenBank. The European type of B. mucronatus was consistently isolated from dead trees, but the pathogenicity of the European type of B. mucronatus on Korean pine is not yet clear. To our knowledge, this is the first report of the European type of B. mucronatus species on P. koraiensis in Korea, but it is already distributed in certain locations of Japan (4), China, and Europe (1). References: (1) H. Braasch et al. Nachrbl. Dtsch. Pflanzenschutzd. 51:312, 1999. (2) W. K. Burgermeister et al. Russ. J. Nematol. 13:29, 2005. (3) Y. Mamiya and N. Enda. Nematologica 25:353, 1979. (4) K. Togashi et al. Jpn. J. For. Res. 13:127, 2008.

X-ray crystallographic and solution state nuclear magnetic resonance spectroscopic investigations of NADP+ binding to ferredoxin NADP reductase from Pseudomonas aeruginosa

The ferredoxin nicotinamide adenine dinucleotide phosphate reductase from Pseudomonas aeruginosa ( pa-FPR) in complex with NADP (+) has been characterized by X-ray crystallography and in solution by NMR spectroscopy. The structure of the complex revealed that pa-FPR harbors a preformed NADP (+) binding pocket where the cofactor binds with minimal structural perturbation of the enzyme. These findings were complemented by obtaining sequential backbone resonance assignments of this 29518 kDa enzyme, which enabled the study of the pa-FPR-NADP complex by monitoring chemical shift perturbations induced by addition of NADP (+) or the inhibitor adenine dinucleotide phosphate (ADP) to pa-FPR. The results are consistent with a preformed NADP (+) binding site and also demonstrate that the pa-FPR-NADP complex is largely stabilized by interactions between the protein and the 2'-P AMP portion of the cofactor. Analysis of the crystal structure also shows a vast network of interactions between the two cofactors, FAD and NADP (+), and the characteristic AFVEK (258) C'-terminal extension that is typical of bacterial FPRs but is absent in their plastidic ferredoxin NADP (+) reductase (FNR) counterparts. The conformations of NADP (+) and FAD in pa-FPR place their respective nicotinamide and isoalloxazine rings 15 A apart and separated by residues in the C'-terminal extension. The network of interactions among NADP (+), FAD, and residues in the C'-terminal extension indicate that the gross conformational rearrangement that would be necessary to place the nicotinamide and isoalloxazine rings parallel and adjacent to one another for direct hydride transfer between NADPH and FAD in pa-FPR is highly unlikely. This conclusion is supported by observations made in the NMR spectra of pa-FPR and the pa-FPR-NADP complex, which strongly suggest that residues in the C'-terminal sequence do not undergo conformational exchange in the presence or absence of NADP (+). These findings are discussed in the context of a possible stepwise electron-proton-electron transfer of hydride in the oxidation of NADPH by FPR enzymes.