First Report of Leaf Spot of Sweet Basil Caused by Cercospora guatemalensis in Korea

Sweet basil, Ocimum basilicum L., is a fragrant herb belonging to the family Lamiaceae. Originated in India 5,000 years ago, sweet basil plays a significant role in diverse cuisines across the world, especially in Asian and Italian cooking. In October 2008, hundreds of plants showing symptoms of leaf spot with nearly 100% incidence were found in polyethylene tunnels at an organic farm in Icheon, Korea. Leaf spots were circular to subcircular, water-soaked, dark brown with grayish center, and reached 10 mm or more in diameter. Diseased leaves defoliated prematurely. The damage purportedly due to this disease has reappeared every year with confirmation of the causal agent made again in 2011. A cercosporoid fungus was consistently associated with disease symptoms. Stromata were brown, consisting of brown cells, and 10 to 40 μm in width. Conidiophores were fasciculate (n = 2 to 10), olivaceous brown, paler upwards, straight to mildly curved, not geniculate in shorter ones or one to two times geniculate in longer ones, 40 to 200 μm long, occasionally reaching up to 350 μm long, 3.5 to 6 μm wide, and two- to six-septate. Conidia were hyaline, acicular to cylindric, straight in shorter ones, flexuous to curved in longer ones, truncate to obconically truncate at the base, three- to 16-septate, and 50 to 300 × 3.5 to 4.5 μm. Morphological characteristics of the fungus were consistent with the previous reports of Cercospora guatemalensis A.S. Mull. & Chupp (1,3). Voucher specimens were housed at Korea University herbarium (KUS). An isolate from KUS-F23757 was deposited in the Korean Agricultural Culture Collection (Accession No. KACC43980). Fungal DNA was extracted with DNeasy Plant Mini DNA Extraction Kits (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced. The resulting sequence of 548 bp was deposited in GenBank (Accession No. JQ995781). This showed >99% similarity with sequences of many Cercospora species, indicating their close phylogenetic relationship. Isolate of KACC43980 was used in the pathogenicity tests. Hyphal suspensions were prepared by grinding 3-week-old colonies grown on PDA with distilled water using a mortar and pestle. Five plants were inoculated with hyphal suspensions and five plants were sprayed with sterile distilled water. The plants were covered with plastic bags to maintain a relative humidity of 100% for 24 h and then transferred to a 25 ± 2°C greenhouse with a 12-h photoperiod. Typical symptoms of necrotic spots appeared on the inoculated leaves 6 days after inoculation, and were identical to the ones observed in the field. C. guatemalensis was reisolated from symptomatic leaf tissues, confirming Koch's postulates. No symptoms were observed on control plants. Previously, the disease was reported in Malawi, India, China, and Japan (2,3), but not in Korea. To our knowledge, this is the first report of C. guatemalensis on sweet basil in Korea. Since farming of sweet basil has recently started on a commercial scale in Korea, the disease poses a serious threat to safe production of this herb, especially in organic farming. References: (1) C. Chupp. A Monograph of the Fungus Genus Cercospora. Ithaca, NY, 1953. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology & Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , May 5, 2012. (3) J. Nishikawa et al. J. Gen. Plant Pathol. 68:46, 2002.

First Report of Anthracnose of Tricyrtis macropoda Caused by Colletotrichum gloeosporioides in Korea

Tricyrtis macropoda Miq. (syn. T. dilatata Nakai), known as speckled toadlily, is a perennial herb native to China, Japan, and Korea. The plant has been highly praised for its beautiful flowers and rare populations in natural habitats. In September 2006, several dozen plants were heavily damaged by leaf spots and blight in cultivated plantings in the city of Pocheon, Korea. The infections with the same symptoms were repeated every year. In July 2011, the same symptoms were found on T. macropoda in the cities of Gapyeong and Osan, Korea. The leaf lesions began as small, water-soaked, pale greenish to grayish spots, which enlarged to form concentric rings and ultimately coalesced. A number of blackish acervuli were formed in the lesions. Acervuli were mostly epiphyllous, circular to ellipsoid, and 40 to 200 μm in diameter. Setae were two- to three-septate, dark brown at the base, paler upwards, acicular, and up to 100 μm long. Conidia (n = 30) were long obclavate to oblong-elliptical, sometimes fusiform-elliptical, guttulate, hyaline, and 12 to 20 × 4 to 6.5 μm (mean 15.4 × 5.2 μm). These morphological characteristics of the fungus were consistent with the description of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (2). Voucher specimens (n = 7) were deposited in the Korea University herbarium (KUS). Two isolates, KACC46374 (ex KUS-F25916) and KACC46405 (ex KUS-F26063), were deposited in the Korean Agricultural Culture Collection. Fungal DNA was extracted and the complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced. The resulting sequences of 549 bp were deposited in Genbank (Accession Nos. JQ619480 and JQ619481). They showed 100% similarity with a sequence of C. gloeosporioides (EU32619). Isolate KACC46374 was used in a pathogenicity test. Inoculum was prepared by harvesting conidia from 3-week-old cultures on potato dextrose agar. A conidial suspension (2 × 10⁶ conidia/ml) was sprayed onto 15 leaves of three plants. Three noninoculated plants served as controls. Plants were covered with plastic bags to maintain 100% relative humidity for 24 h and then kept in a greenhouse (22 to 28°C and 70 to 80% RH). After 5 days, typical leaf spot symptoms, identical to the ones observed in the field, started to develop on the leaves of inoculated plants. No symptoms were observed on control plants. C. gloeosporioides was reisolated from the lesions of inoculated plants, thus fulfilling Koch's postulates. An anthracnose associated with C. tricyrtii (Teng) Teng was recorded on T. formosana and T. latifolia in China (3) and on T. formosana in Taiwan (1), respectively, without etiological studies. The morphological features of C. tricyrtii are within the variation of C. gloeosporioides (2). To our knowledge, this is the first report of anthracnose of T. macropoda. This report has significance to indigenous plant resource conservation managers and scientists because T. macropoda has been listed as one of the 126 "Rare and Endangered Plants" by the Korea Forest Service since 1991. References: (1) K. Sawada. Rep. Dept. Agric. Gov. Res. Inst. Formosa 87: 1, 1944. (2) B. C. Sutton. Pages 1-27 in: Colletotrichum Biology, Pathology and Control. J. A. Bailey and M. J. Jeger, eds. CAB International, Wallingford, U.K. 1992. (3) S. C. Teng. Contrib. Biol. Lab. Sci. Soc. China 8:36, 1932.

First Report of Leaf Spot of Rudbeckia hirta var. pulcherrima Caused by Septoria rudbeckiae in Korea

Rudbeckia hirta L. var. pulcherrima Farw. (synonym R. bicolor Nutt.), known as the black-eyed Susan, is a flowering plant belonging to the family Asteraceae. The plant is native to North America and was introduced to Korea for ornamental purposes in the 1950s. In July 2011, a previously unknown leaf spot was first observed on the plants in a public garden in Namyangju, Korea. Leaf spot symptoms developed from lower leaves as small, blackish brown lesions, which enlarged to 6 mm in diameter. In the later stages of disease development, each lesion was usually surrounded with a yellow halo, detracting from the beauty of the green leaves of the plant. A number of black pycnidia were present in diseased leaf tissue. Later, the disease was observed in several locations in Korea, including Pyeongchang, Hoengseong, and Yangpyeong. Voucher specimens were deposited at the Korea University Herbarium (KUS-F25894 and KUS-F26180). An isolate was obtained from KUS-F26180 and deposited at the Korean Agricultural Culture Collection (Accession No. KACC46694). Pycnidia were amphigenous, but mostly hypogenous, scattered, dark brown-to-rusty brown, globose, embedded in host tissue or partly erumpent, 50 to 80 μm in diameter, with ostioles 15 to 25 μm in diameter. Conidia were substraight to mildly curved, guttulate, hyaline, 25 to 50 × 1.5 to 2.5 μm, and one- to three-septate. Based on the morphological characteristics, the fungus was consistent with Septoria rudbeckiae Ellis & Halst. (1,3,4). Morphological identification of the fungus was confirmed by molecular data. Genomic DNA was extracted using the DNeasy Plant Mini DNA Extraction Kit (Qiagen Inc., Valencia, CA.). The internal transcribed spacer (ITS) region of rDNA was amplified using the ITS1/ITS4 primers and sequenced. The resulting sequence of 528 bp was deposited in GenBank (Accession No. JQ677043). A BLAST search showed that there was no matching sequence of S. rudbeckiae; therefore, this is the first ITS sequence of the species submitted to GenBank. The ITS sequence showed >99% similarity with those of many Septoria species, indicating their close phylogenetic relationship. Pathogenicity was tested by spraying leaves of three potted young plants with a conidial suspension (2 × 10⁵ conidia/ml), which was harvested from a 4-week-old culture on potato dextrose agar. Control leaves were sprayed with sterile water. The plants were covered with plastic bags to maintain 100% relative humidity (RH) for the first 24 h. Plants were then maintained in a greenhouse (22 to 28°C and 70 to 80% RH). After 5 days, leaf spot symptoms identical to those observed in the field started to develop on the leaves inoculated with the fungus. No symptoms were observed on control plants. S. rudbeckiae was reisolated from the lesions of inoculated plants, confirming Koch's postulates. A leaf spot disease associated with S. rudbeckiae has been reported on several species of Rudbeckia in the United States, Romania, and Bulgaria (1-4). To our knowledge, this is the first report of leaf spot on R. hirta var. pulcherrima caused by S. rudbeckiae in Korea. References: (1) J. B. Ellis and B. D. Halsted. J. Mycol. 6:33, 1890. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ February 2, 2012. (3) E. Radulescu et al. Septoriozele din Romania. Ed. Acad. Rep. Soc. Romania, Bucuresti, Romania, 1973. (4) S. G. Vanev et al. Fungi Bulgaricae 3:1, 1997.

Predictors for lymph node metastasis in T1 colorectal cancer

BACKGROUND AND STUDY AIMS

It is critical that the risk of lymph node metastasis (LNM) is evaluated for determining the suitability of endoscopic resection for T1 colorectal cancer (CRC). Reported risk factors for LNM in completely resected T1 CRC are deep submucosal invasion, grade 3, angiolymphatic invasion, and budding. The aim of the present study was to identify the histopathologic factors associated with LNM in T1 CRC.

PATIENTS AND METHODS

The study involved 435 patients with T1 CRC treated by endoscopic or surgical resection between January 2001 and April 2010 at the National Cancer Center, Korea. The 435 patients were classified into two groups - those undergoing surgical resection (n = 324) and those undergoing endoscopic resection (n = 111). In the surgically resected group, details regarding depth of submucosal invasion, angiolymphatic invasion, tumor grade, budding, and background adenoma (BGA) were evaluated with respect to presence or absence of LNM. In the endoscopically resected group, the results of follow-ups and additional salvage surgeries were studied.

RESULTS

In the surgically resected group, LNM was detected in 42 patients (13.0 %). Grade 3, angiolymphatic invasion, budding, and the absence of BGA were identified as factors associated with LNM in univariate and multivariate analyses (P < 0.05). Among the 50 patients in the endoscopically resected group with high risk, three were diagnosed as being LNM-positive during the follow-up period. There was no LNM in the endoscopically resected group with low risk.

CONCLUSIONS

Grade 3, angiolymphatic invasion, budding, and the absence of BGA are the risk factors that predict LNM in patients with T1 CRC. In cases where endoscopically resected T1 CRC has no risk factor, cautious follow-up could be recommended. However, if the tumor has any risk factor, additional surgical resection should be considered.

First Report of Leaf Blight and Stem Canker of Pachysandra terminalis Caused by Pseudonectria pachysandricola in Korea

Pachysandra terminalis Siebold & Zucc., known as Japanese pachysandra, is a creeping evergreen perennial belonging to the family Buxaceae. In April 2011, hundreds of plants showing symptoms of leaf blight and stem canker with nearly 100% incidence were found in a private garden in Suwon, Korea. Plants with the same symptoms were found in Seoul in May and Hongcheon in August. Affected leaves contained tan-to-yellow brown blotches. Stem and stolon cankers first appeared as water soaked and developed into necrotic lesions. Sporodochia were solitary, erumpent, circular, 50 to 150 μm in diameter, salmon-colored, pink-orange when wet, and with or without setae. Setae were hyaline, acicular, 60 to 100 μm long, and had a base that was 4 to 6 μm wide. Conidiophores were in a dense fascicle, not branched, hyaline, aseptate or uniseptate, and 8 to 20 × 2 to 3.5 μm. Conidia were long, ellipsoid to cylindric, fusiform, rounded at the apex, subtruncate at the base, straight to slightly bent, guttulate, hyaline, aseptate, 11 to 26 × 2.5 to 4.0 μm. A single-conidial isolate formed cream-colored colonies that turned into salmon-colored colonies on potato dextrose agar (PDA). Morphological and cultural characteristics of the fungus were consistent with previous reports of Pseudonectria pachysandricola B.O. Dodge (1,3,4). Voucher specimens were housed at Korea University (KUS). Two isolates, KACC46110 (ex KUS-F25663) and KACC46111 (ex KUS-F25683), were accessioned in the Korean Agricultural Culture Collection. Fungal DNA was extracted with DNeasy Plant Mini DNA Extraction Kits (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced using ABI Prism 337 automatic DNA sequencer (Applied Biosystems, Foster, CA). The resulting sequence of 487 bp was deposited in GenBank (Accession No. JN797821). This showed 100% similarity with a sequence of P. pachysandricola from the United States (HQ897807). Isolate KACC46110 was used in pathogenicity tests. Inoculum was prepared by harvesting conidia from 2-week-old cultures on PDA. Ten young leaves wounded with needles were sprayed with conidial suspensions (~1 × 10⁶ conidia/ml). Ten young leaves that served as the control were treated with sterile distilled water. Plants were covered with plastic bags to maintain a relative humidity of 100% at 25 ± 2°C for 24 h. Typical symptoms of brown spots appeared on the inoculated leaves 4 days after inoculation and were identical to the ones observed in the field. P. pachysandricola was reisolated from 10 symptomatic leaf tissues, confirming Koch's postulates. No symptoms were observed on control plants. Previously, the disease was reported in the United States, Britain, Japan, and the Czech Republic (2,3), but not in Korea. To our knowledge, this is the first report of P. pachysandricola on Pachysandra terminalis in Korea. Since this plant is popular and widely planted in Korea, this disease could cause significant damage to nurseries and the landscape. References: (1) B. O. Dodge. Mycologia 36:532, 1944. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , September 24, 2011. (3) I. Safrankova. Plant Prot. Sci. 43:10, 2007. (4) W. A. Sinclair and H. H. Lyon. Disease of Trees and Shrubs. 2nd ed. Cornell University Press, Ithaca, NY, 2005.

First Report of Powdery Mildew Caused by Golovinomyces biocellatus on Monarda didyma in Korea

Bergamot (Monarda didyma L.), which is native to eastern North America, is an aromatic herb in the family Lamiaceae. It is widely planted in gardens and parks for ornamental purposes and also grown indoors as a fragrant houseplant in Korea. In October 2007, several dozen bergamots planted outdoors in Bonghwa, Korea were found to be heavily infected with a powdery mildew. Symptoms first appeared as thin, white colonies, which subsequently developed into abundant growth on both sides of the leaves. Severe infections often caused leaf distortions and premature senescence. The same symptoms have also been found in bergamot plots in Osan, Suwon, Incheon, and Seoul from 2007 to 2011. Voucher specimens were deposited at Korea University, Seoul, Korea. Hyphae were septate, branched, and 4 to 8 μm wide. Appressoria on the mycelium were nipple shaped. Conidiophores arose from the lateral part of the hyphae, measured 100 to 180 × 10 to 12 μm, were simple, and produced two to four immature conidia in chains, followed by two to three cells. Conidia were hyaline, ellipsoid to barrel shaped, measured 28 to 40 × 16 to 20 μm (length/width ratio = 1.4 to 2.2), lacked distinct fibrosin bodies, and produced germ tubes on the subterminal position, with reticulate wrinkling of the outer walls. No chasmothecia were observed. The structures described above were typical of the Oidium subgenus Reticuloidium anamorph of the genus Golovinomyces, and the fungus measurements were compatible with those of Golovinomyces biocellatus (Ehrenb.) V.P. Heluta as described previously (1,4). The only other powdery mildew known on Monarda spp. is Neoerysiphe galeopsidis (1), which is clearly distinguished by its lobed hyphal appressoria and fine striations on conidial surfaces. To confirm the tentative identification based on morphological characteristics, internal transcribed spacer (ITS) rDNA sequences from two representative isolates (KUS-F23070 and F23117) were obtained using primers ITS5 and P3 as described by Takamatsu et al. (3). The resulting sequences of 523 bp were deposited in GenBank (Accession Nos. JN228358 and JN228359). A GenBank BLAST search produced an exact match for the sequences of G. biocellatus on several plants belonging to the Lamiaceae, with a 100% sequence similarity. Pathogenicity was confirmed through inoculation by gently pressing diseased leaves onto leaves of five healthy potted bergamot plants. Five noninoculated plants served as controls. Plants were maintained in a greenhouse at 25 ± 2°C. Inoculated plants developed signs and symptoms after 6 days, whereas the control plants remained healthy. The fungus present on the inoculated plants was morphologically identical to that originally observed on diseased plants. The powdery mildew infections of bergamot plants associated with G. biocellatus have been known in Europe (2) and Japan (4). The current work confirmed the occurrence of G. biocellatus infecting M. didyma in Korea. References: (1) U. Braun. Beih. Nova Hedw. 89:1, 1987. (2) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory. ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , July 12, 2011, (3) S. Takamatsu et al. Mycol. Res. 113:117, 2009. (4) S. Tanda. J. Agric. Sci. Tokyo Agric. Univ. 47:274, 1997.

Frameless stereotactic placement of ventriculoperitoneal shunts in undersized ventricles: a simple modification to free-hand procedures

The aim of this report is to introduce a simple modification to the free-hand frameless stereotactic placement of ventriculoperitoneal shunts in undersized ventricles. In this technical note, we describe our experience with ventricular catheter placement in two children suffering from shunt dependent idiopathic intracranial hypertension using an image-guided instrument holder with a catheter guide. In both patients, the surgical procedure proved to be easy and accurate, with good initial clinical results. The use of an image-guided instrument holder is a modification to the free-hand frameless stereotactic placement of ventriculoperitoneal shunts in undersized ventricles.

Methotrexate, vinblastine, doxorubicin and cisplatin combination regimen as salvage chemotherapy for patients with advanced or metastatic transitional cell carcinoma after failure of gemcitabine and cisplatin chemotherapy

We investigated the safety and efficacy of a methotrexate, vinblastine, doxorubicin and cisplatin (M-VAC) combination regimen as second-line chemotherapy for patients with advanced or metastatic transitional cell carcinoma who failed first-line gemcitabine and cisplatin (GC) chemotherapy. Thirty patients who had progressed or relapsed after GC chemotherapy as first-line treatment were enrolled in this study. The major toxicities were neutropaenia and thrombocytopaenia. A grade 3 or 4 neutropaenia occurred in 19 (63.3%) and a grade 3 or 4 thrombocytopaenia developed in nine patients (30.0%). There were no life-threatening complications during the study. The overall response was 30%. A complete response was achieved in two patients (6.7%) and a partial response in seven (23.3%). The overall disease control rate was 50%. Seven out of 16 patients who had responded previously to GC responded to M-VAC, while 2 out of 14 who had not responded to GC responded to M-VAC. The median response duration was 3.9 months and the median progression-free survival was 5.3 months. The median overall survival was 10.9 months. M-VAC showed encouraging efficacy and reversible toxicities in patients who had progressed after GC chemotherapy and, especially, M-VAC appears to be a reasonable option as a sequential treatment regimen in patients who responded previously to GC chemotherapy.

Factors influencing pain during transrectal ultrasonography-guided prostate biopsy

We prospectively investigated the clinical parameters that influenced pain during prostate biopsies. From 12 hospitals 1781 patients were enrolled. The patients completed a visual analogue scale questionnaire for the pain during the procedure. Age, enema preparation, analgesia use and number of biopsy punctures influenced the level of pain during prostate biopsy in univariate linear regression analysis. However, multivariate analysis showed enema preparation, analgesia use and number of biopsy punctures were independent factors associated with the pain during the procedure. Our study confirmed enema preparation before biopsy and the number of biopsy punctures were associated with the pain during prostate biopsy.

The usefulness of preoperative colonoscopic tattooing using a saline test injection method with prepackaged sterile India ink for localization in laparoscopic colorectal surgery

BACKGROUND

Laparoscopic surgery for colorectal neoplasm requires precise tumor localization. The authors have assessed the safety and efficacy of colonoscopic tattooing using a saline test injection method with prepackaged sterile India ink for tumor localization in laparoscopic colorectal surgery.

METHODS

Between July 2004 and January 2007, 63 patients underwent colonoscopic tattooing using prepackaged sterile India ink before laparoscopic surgery of colorectal tumors. Patient medical records and operation videos were retrospectively assessed.

RESULTS

Tattoos were visualized intraoperatively in 62 (98.4%) of the 63 patients, and colorectal tumors were accurately localized in 61 patients (96.8%). In one patient, the tattoo could not be detected, whereas in another patient, it was visualized but the serosal surface of the rectosigmoid colon was stained diffusely. Both of these patients underwent intraoperative colonoscopy. Localized leakages of ink were identified in six patients (9.5%) during surgery. However, five of these patients had no symptoms, and the sixth patient, who underwent polypectomy and tattooing simultaneously, felt mild chilling without fever or abdominal pain.

CONCLUSIONS

Preoperative colonoscopic tattooing using a saline test injection method with prepackaged sterile India ink is a safe and effective method for tumor localization in laparoscopic colorectal surgery.

Effects of Lactobacillus strains on cancer cell proliferation and oxidative stress in vitro

AIMS

The objective of this study was to assess in vitro, whether heat-killed (HK) lactic acid bacteria cells and fractionations of HK cells could suppress the viability of human cancer cells and inhibit the cytotoxicity associated with oxidative stress.

METHODS AND RESULTS

Among the strains, the HK cells of Lactobacillus acidophilus 606 and Lactobacillus casei ATCC 393 exhibited the most profound inhibitory activity in all of the tested cell lines. HK cells of L. acidophilus 606 were determined to be less toxic to healthy human embryo fibroblasts (hEF cells) than were HK cells of L. casei ATCC 393. The soluble polysaccharides from L. acidophilus 606 evidenced the most effective anticancer activity, but inhibited hEF cell growth by only 20%. The soluble polysaccharides from L. acidophilus 606 were partly observed to induce apoptosis in the HT-29 cells by DNA fragmentation and propidium iodine staining. Both the HK cells of L. acidophilus 606 and the soluble polysaccharide components of this strain also exhibited potent antioxidative activity.

CONCLUSIONS

Our findings suggest that the soluble polysaccharide fraction from L. acidophilus 606 may constitute a novel anticancer agent, which manifests a high degree of selectivity for human cancer cells and antioxidative agent in the food industry.

SIGNIFICANCE AND IMPACT OF THE STUDY

These soluble polysaccharide components from Lactobacillus may be applied to various foods, and used as adjuncts for cancer therapy and prevention.

Optimization of technical conditions for the transformation of Lactobacillus acidophilus strains by electroporation

AIMS

To optimize the conditions for electroporating foreign plasmid DNA into Lactobacillus acidophilus ATCC 43121.

METHODS AND RESULTS

The conditions of electroporation were optimized to improve the transformation efficiency. Plasmid pNZ123 containing multicloning site and chloramphenicol resistance was employed to construct a cloning vector. The optimum electroporation conditions for the maximum transformation efficiency were a pulse strength of 12.5 kV cm(-1), a pulse number of 10, a pulse interval of 500 ms, and pNZ123 plasmid DNA concentration of 25 ng microl(-1). Under the optimum conditions the transformation efficiency of L. acidophilus ATCC 43121 was 1.84 +/- 0.13 x 10(4) (+/- standard error of measurements) CFU per mug of plasmid DNA. Other strains of L. acidophilus showed transformation efficiencies ranging from 1.38 +/- 0.02 x 10(4) to 9.32 +/- 0.54 x 10(4) under these conditions. A green fluorescent protein (GFP) was successfully expressed and detected by fluorescence microscopy when the pKU::slpA-GFP, pNZ123 containing GFP gene, was transformed in L. acidophilus ATCC 43121 under the optimum conditions.

CONCLUSIONS

The results suggest that electrical parameters, antibiotic concentration, and host specificity play important roles to determine transformation efficiency of lactobacilli. The optimum conditions for the transformation of L. acidophilus ATCC 43121 may be applied to improve transformation efficiency of other lactobacilli.

SIGNIFICANCE AND IMPACT OF THE STUDY

The optimized conditions for electrotransformation may provide a mean to improve the introduction of foreign DNA into L. acidophilus to be used as a vehicle for a heterologous protein expression.

Autologous peripheral blood stem cell transplantation with BCVAC conditioning in childhood acute myeloid leukemia

Autologous peripheral blood stem cell transplantation (APBSCT) after intensifying conditioning is one of the post-remission therapeutic options in childhood acute myeloid leukemia (AML) patients without a matched family donor, but the optimal conditioning regimen has not been defined. This study was performed to evaluate the efficacy of a novel conditioning regimen without busulfan or total body irradiation. In total, 28 children with AML underwent APBSCT with BCVAC (BCNU, etoposide, cytosine arabinoside and cyclophosphamide) conditioning regimen during first remission. The event-free survival rate was 71.43% for all patients and the only cause of treatment failure was relapse. Eight male patients recurred at 1-11 months (median 5 months) after APBSCT. One patient remains alive with salvage therapy after relapse. With the exception of fever, mucositis and diarrhea, no serious complications occurred during APBSCT, including veno-occlusive disease (VOD), and there was no transplantation-related mortality. One patient developed secondary MDS after APBSCT but recovered hematologically on medication. APBSCT with BCVAC conditioning was found to be a safe and effective alternative option for patients with childhood AML in first remission, without a matched family donor.

Functionality and physico-chemical characteristics of bovine and caprine mozzarella cheeses during refrigerated storage

Low moisture part-skim Mozzarella cheeses (MC) were manufactured using fresh bovine and caprine milk to study melting, physico-chemical, textural, and microstructural properties of the cheeses during 8 wk of refrigerated storage. Structural changes in cheese matrix were evaluated by scanning electron microscopy and by proteolytic patterns using nitrogen solubility, SDS-PAGE, and Gel-pro analyzer. Meltability of ripened cow and goat MC were not different when fat content of both milks were standardized, whereas bovine MC formed a significantly larger amount of free oil throughout the experiment. The results of the proteolytic patterns, texture attribute (cohesiveness), and microstructure revealed that bovine MC had a greater structural degradation of cheese matrix than caprine MC during the storage. Elevated protein degradation in bovine MC led to more intense brown color formation than the goat counterpart when the cheeses were baked. The melting characteristics showed high positive correlation (r = 0.51 to 0.80) with proteolysis, whereas it was negatively correlated with textural characteristics. Among textural attributes, cohesiveness was highly inversely correlated with melting characteristics (r = -0.69 to -0.88). High negative correlations were also observed between proteolytic parameters and textural attributes (r = -0.48 to -0.81).

Glanzmann's thrombasthenia due to a point mutation within intron 10 results in aberrant splicing of the beta3 gene

Glanzmann's thrombasthenia (GT) is an hereditary bleeding disorder caused by a quantitative or qualitative defect in the integrin alphaIIbbeta3. We attempted to identify genetic defects responsible for a case of GT in Korea. The patient was a 6-year-old boy who had suffered from hemorrhage and purpura. The cDNAs of alphaIIb and beta3 were amplified by reverse transcription (RT)-PCR and were sequenced. RT-PCR of COS7 cells transfected with Exontrap vectors containing the beta3 genomic DNA fragments were performed to verify an aberrant splicing. Transient expression of alphaIIbbeta3 on transfected-COS7 cells was determined by flow cytometry, and the presence of alphaIIbbeta3 was confirmed by immunoprecipitation. We discovered an abnormality with the insertion of 38 bp between exon 10 and exon 11, including a stop codon, in beta3 cDNA. Sequence analysis of genomic DNA showed a point mutation, G-->T, at the position 29 107 of intron 10. RT-PCR analyses of COS7 cells transfected with Exontrap vector containing the mutant beta3 gene revealed that the point mutation at the position 29 107 of intron 10, G-->T, was responsible for an aberrant splicing in the beta3 gene. The transfection experiments and immunoprecipitation revealed the absence of alphaIIbbeta3 in the COS7 cells transfected with mutant gene. The mutation at the position 29 107 of intron 10, G-->T, in the beta3 genomic DNA was found to induce an aberrant splicing and to be responsible for GT in this patient.

Right stereoisomers for sex pheromone components of the apple leafminer, Lyonetia prunifoliella, in Korea

The sex pheromone of the American population of Lyonetia prunifoliella (Lepidoptera: Lyonetiidae) was reported to be composed of three components, 10,14-dimethyloctadec-1-ene (10me14me-1-ene-18Hy), 5,9-dimethyloctadecane (5me9me-18Hy), and 5,9-dimethylheptadecane (5me9me-17Hy). Studies with a Korean population showed that the 10S, 14S isomer of the major compound was the major electrophysiologically by active stereoisomer. The 5S,9S isomers of the minar constituents also elicited electrophysiological responses. In field trappings, among the three components, the racemic mixture of 10me14me-1-ene-18Hy attracted L. prunifoliella males strongly, and the binary or tertiary combinations with racemic mixtures of the other two components did not increase trap catches. Among the four stereoisomers of 10me14me-1-ene-18Hy, only the 10S,14S isomer attracted L. prunifoliella males, as suggested by the EAG test, and attraction to the other three isomers was not observed. All stereoisomers of each minor component, as well as their racemic components, did not seem to have any additional effect on male attraction in Korea.

HLA-B*44 allele frequencies and haplotypic associations in Koreans

We have investigated the frequencies of HLA-B*44 alleles and their haplotypic associations with HLA-A, -C, and -DRB1 loci in 450 healthy unrelated Koreans, including 213 parents from 107 families. All 79 samples (17.6%) typed as B44 by serology were analyzed for B*44 alleles using polymerase chain reaction (PCR) single-strand conformation polymorphism (SSCP) method. A total of three different B*44 alleles were detected: B*44031 (allele frequency 4.7%), B*44032 (3.1%), and B*4402 (1.3%). Three characteristic haplotypes revealing strong linkage disequilibrium were A*3303-Cw*1403-B*44031-DRB1*1302 (3.6%), A*3303-Cw*07-B*44032-DRB1*0701 (2.8%), and A*3201-Cw*05-B*4402-DRB1*0405 (0.4%). In addition, a strong association was observed for B*4402 with A*0301. The B*4403-bearing haplotypes of Koreans appear to be relatively common in Asian populations, whereas the B*4402-bearing haplotypes share some similarity to those of Caucasians. HLA-B44 alleles demonstrate a limited allelic diversity and comprise distinctive extended haplotypes in the Korean population. It is suggested that the frequencies of B44 subtype mismatches among ABDRB1-matched unrelated donor-recipient pairs would be low in this population.

1,2-bis(2-Aminophenoxy)ethane-N,N,N',N'-tetraacetic acid induces caspase-mediated apoptosis and reactive oxygen species-mediated necrosis in cultured cortical neurons

Sustained alteration in [Ca(2+)]i triggers neuronal death. We examined morphological and signaling events of Ca(2+)-deficiency-induced neuronal death. Cortical cell cultures exposed to 20 microM 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM), an intracellular calcium chelator, underwent neuronal apoptosis within 12 h that was evident by shriveled cell bodies, aggregated and condensed nuclear chromatin, and disrupted nuclear membrane. Thereafter, surviving neurons revealed typical necrosis, accompanied by swelling of cell body and mitochondria, over 24 h. Both apoptosis and necrosis were prevented by inclusion of 1 microg/mL cycloheximide, a protein synthesis inhibitor. Treatment with BAPTA-AM induced translocation of Bax into mitochondria within 4 h and release of cytochrome c from mitochondria over 4-12 h. An active fragment of caspase-3, a downstream mediator of cytochrome c, was observed within 8 h and cleaved PHF-1-positive tau. Administration of zVAD-fmk, a broad inhibitor of caspases, or DEVD-amc, a selective inhibitor of caspase-3, selectively prevented the apoptosis component of BAPTA-AM neurotoxicity. In contrast, BAPTA-AM-induced necrosis was propagated through sequential production of superoxide, mitochondrial and cytoplasmic reactive oxygen species. Combined treatment with caspase inhibitors and antioxidants blocked BAPTA-AM neurotoxicity. The present study suggests that neurons deficient in [Ca(2+)]i undergo caspase-3-mediated apoptosis and reactive oxygen species (ROS)-mediated necrosis.

Hypoxia induces apoptosis by caspase activation accompanying cytochrome C release from mitochondria in MC3T3E1 osteoblasts. p38 MAPK is related in hypoxia-induced apoptosis

The aim of this study is to elucidate the possible mechanism of apoptosis in response to hypoxia in MC3T3E1 osteoblasts. MC3T3E1 osteoblasts under hypoxic conditions (2% oxygen) resulted in apoptosis in a time-dependent manner estimated by DNA fragmentation assay and nuclear morphologystained with fluorescent dye, Hoechst 33258. Pretreatment with Z-VAD-FMK, a pan-caspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, completely suppressed the DNA ladder in response to hypoxia. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase- activity (YVADase) was detected. To confirm what caspases are involved in apoptosis, western blot analysis was performed using anti-caspase-3 or -6 antibody. The 10-kDa protein, corresponding to the active products of caspase-3 and the 10-kDA protein of the active protein of caspase-6 were generated in hypoxia-challenged cells in which processing of the full length form of caspase-3 and -6 was evident. With a time course similar to this caspase-3 and -6 activation was evident, hypoxic stress caused the cleavage of lamin A, typical of caspase-6 activity. In addition, the stress elicited the release of cytochrome c into the cytosol during apoptosis. Furthermore, we have observed that pre-treatment with SB203580, a selective p38 MAP kinase (p38 MAPK) inhibitor, attenuated the hypoxia-induced apoptosis. The addition of SB203580 suppressed caspase-3 and -6-like protease activity by hypoxia up to 50%. In contrast, PD98059 had no effect on the hypoxia-induced apoptosis. To confirm the involvement of MAP kinase, JNK/SAPK, ERK, or p38 kinase assay was performed. Although p38 MAPK was activated in response to hypoxic treatment, the other MAP kinase -JNK/SAPK or ERK- was not or modestly activated. These results suggest that p38 MAPK positively regulates hypoxia-induced apoptosis in MC3T3E1 osteoblasts.

The p38 mitogen-activated protein kinase pathway regulates interleukin-6 synthesis in response to tumor necrosis factor in osteoblasts

The induction of interleukin-6 (IL-6), using a proinflammatory cytokine (tumor necrosis factor-alpha), was studied in a human osteoblast cell line (MG-63) in relation to p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-kappaB transcription factor. When added to MG-63 cells, tumor necrosis factor-alpha (TNF-alpha) had a stimulatory effect on the production of IL-6, and this elevation was significantly reduced by SB203580, a specific p38 MAPK inhibitor. In addition, the stimulation of IL-6 release was also reduced by pyrrolidine dithiocarbamate (PDTC) or NF-kappaB SN50, which has been reported to be a potent NF-kappaB inhibitor. Both the NF-kappaB inhibitors in the presence of SB203580 had a more inhibitory effect on IL-6 release. In this study, TNF-alpha stimulated NF-kappaB binding affinity as well as p38 MAP kinase activation, leading to the release of IL-6. However, the specific inhibitor of p38 MAPK, SB203580, had no effect on TNF-alpha-induced NF-kappaB activation and both NF-kappaB inhibitors failed to reduce the p38 MAPK activation in the TNF-alpha-stimulated osteoblasts. In addition, inhibition of p38 MAPK partially, but significantly, impaired TNF-alpha-regulated release of osteocalcin, an important differentiation marker in osteoblasts. These results strongly suggest that both p38 MAPK and NF-kappaB are required in TNF-alpha-induced IL-6 synthesis and that these two TNF-alpha-activated pathways can be primarily dissociated. Furthermore, p38 MAPK may play a significant role in differentiation in MG-63 cells.