[Mechanism of intestinal injury induced by WNT2B high-expressed fibroblasts in Crohn's disease]

Objective: To explore the mechanism of intestinal tissue damage induced by macrophages activated by WNT2B high-expressed fibroblasts. Methods: This study involved biological information analysis, pathological tissue research and cell experimental research. The biological information of the colon tissue from the children with inflammatory bowel disease in previous study was analyzed again with single-cell sequencing. The pathological tissues were collected by colonoscopy from 10 children with Crohn's disease treated in the Department of Gastroenterology of Guangzhou Women and Children's Medical Center from July 2022 to September 2022. According to the findings of colonoscopy, tissues with obvious inflammation or ulceration were classified as the inflammatory group, while tissues with slight inflammation and no ulceration were classified as the non-inflammatory group. HE staining was performed to observe the pathological changes of the colon tissues. Macrophage infiltration and CXCL12 expression were detected by immunofluorescence. In terms of cell experiments, fibroblasts transfected with WNT2B plasmid or empty plasmid were co-cultured with salinomycin treated or non-treated macrophages, respectively; the expression of proteins through Wnt classical pathway were detected by western blotting. Macrophages treated with SKL2001 were used as the experimental group, and those with phosphate buffer as the control group. The expression and secretion of CXCL12 in macrophages were detected by quantitative Real-time PCR and enzyme-linked immunosorbent assay (ELISA). T-test or rank sum test were used for the comparison between groups. Results: Single-cell sequencing analysis suggested that macrophages were the main cells in inflammatory bowel disease colon tissue, and there was interaction between WNT2B high-expressed fibroblasts and macrophages. HE staining of the 10 patients ((9.3±3.8) years old, 7 males and 3 females) showed that the pathological score of colon tissue in the inflammatory group was higher than that in the non-inflammatory group (4 (3, 4) vs. 2 (1, 2) points, Z=3.05, P=0.002). Tissue immunofluorescence indicated that the number of infiltrating macrophages in the inflammatory group was significantly higher than that in the non-inflammatory group under high power field of view (72.8±10.4 vs.8.4±3.5, t=25.10, P<0.001), as well as the number of cells expressing CXCL12 (14.0±3.5 vs. 4.7±1.9, t=14.68, P<0.001). In cell experiments, western blotting suggested an elevated level of glycogen synthase kinase-3β phosphorylation in macrophages co-cultured with fibroblast transfected with WNT2B plasmid, and salinmycin could reverse this change. Real-time PCR suggested that the transcription level of CXCL12 in the experimental group was higher than that in the control group (6.42±0.04 vs. 1.00±0.03, t=183.00, P<0.001), as well as the expression and secretion of CXCL12 by ELISA ((465±34) vs. (77±9) ng/L, t=13.21, P=0.006). Conclusion: WNT2B high-expressed fibroblasts can secrete WNT2B protein and activate the Wnt classical signaling pathway thus enhancing the expression and secretion of CXCL12 in macrophages, inducing the development of intestinal inflammation of Crohn's disease.

Adiabatic versus non-adiabatic electron transfer at 2D electrode materials

2D electrode materials are often deployed on conductive supports for electrochemistry and there is a great need to understand fundamental electrochemical processes in this electrode configuration. Here, an integrated experimental-theoretical approach is used to resolve the key electronic interactions in outer-sphere electron transfer (OS-ET), a cornerstone elementary electrochemical reaction, at graphene as-grown on a copper electrode. Using scanning electrochemical cell microscopy, and co-located structural microscopy, the classical hexaamineruthenium (III/II) couple shows the ET kinetics trend: monolayer > bilayer > multilayer graphene. This trend is rationalized quantitatively through the development of rate theory, using the Schmickler-Newns-Anderson model Hamiltonian for ET, with the explicit incorporation of electrostatic interactions in the double layer, and parameterized using constant potential density functional theory calculations. The ET mechanism is predominantly adiabatic; the addition of subsequent graphene layers increases the contact potential, producing an increase in the effective barrier to ET at the electrode/electrolyte interface.

The bridge stenting-based internal drainage in pancreatic trauma patients with main pancreatic duct injury

Pancreatic trauma is associated with high mortality and morbidity, especially in main pancreatic duct (MPD) injuries. Here, we introduce a novel technique via the placement of bridge stenting-based internal drainage (BSID) along the injured MPD to restore pancreatic tissue integrity. Twelve patients with MPD injury underwent unobstructed BSID as physical support for healing. Six patients with peripheral organ injuries underwent operative end-to-end anastomosis of the MPD by using a polyurethane central venous catheter for the BSID, and the other six patients with isolated proximal MPD rupture received BSID via endoscopic pancreatic stent placement. The BSID technique was successfully performed in all pancreatic trauma patients without the need for a second open surgery. With this simplified BSID-based operation, a short procedure duration (242.7 ± 38.71 min in the surgical group and 100.2 ± 16.24 min in the endoscopic group) and a short hospital stay (13.0 ± 7.05 days) were achieved. However, a few complications (41.67%) still occurred, including pancreatitis, fistula, abscess, pseudocyst, cholangitis, and haemorrhage. Except for the deceased case, all postoperative courses were marked by decreases in the peripancreatic fluid collection, blood amylase recovery, and normal endocrine function. The BSID approach is a feasible surgical approach for the treatment of MPD injury and can be used endoscopically in isolated MPD injuries for its safety and convenience.

Acute Toxicity and Hazardous Concentrations of Zinc to Native Freshwater Organisms Under Different pH Values in China

Zinc bioavailability to aquatic organisms varies greatly under different pH values. In the present study, five native species in China and four common international test species were selected to investigate the influence of changing pH on acute zinc toxicity. The results showed that the higher trophic levels exhibited increasing sensitivity to zinc as pH decreased. However, when the pH value was between 8 and 11, the acute toxicity of zinc was relatively constant. In addition, by using a species-sensitivity distribution (SSD) method, the short-term hazardous concentrations of zinc at different pH values (based on the 5th percentiles of the pH-specific SSDs) were determined to be 17.26 µg/L (pH 4), 48.31 µg/L (pH 5), 80.34 µg/L (pH 6) and 230.6 µg/L (pH 7), respectively. The present study provides useful information for deriving water quality criteria and assessing the risks of metals in the near future.

Single-operator cholangioscopy for the treatment of concomitant gallbladder stones and secondary common bile duct stones

BACKGROUND AND AIM

This study aims to assess the clinical validity and safety of single-operator cholangioscopy system (SOCS) for the treatment of concomitant gallbladder stones and secondary common bile duct (CBD) stones.

METHODS

This retrospective study included 10 consecutive patients who had small-sized stones (< 1 cm) in both the gallbladder and CBD; the patients underwent SOCS treatment from June 2016 to December 2016. The clinical validity of this minimally invasive surgery was determined by the operation success rate, stone removal rate, postoperative hospital stay, hospitalization cost, and contrast images before and after the operation. The clinical safety was evaluated by perioperative complications and outcomes, gallbladder stone recurrence, and gallbladder contractility function.

RESULTS

Both the technique success rate and the stone removal rate when using SOCS was 100%. There were no serious complications that occurred during the operation; three patients developed acute cholecystitis, and four patients underwent hyperamylasemia after the surgery. The average postoperative hospital stay was 5.8 ± 1.32 days, and the average hospitalization cost was 7466 ± 566.1 dollars. In the follow-up period, which ranged from 3 to 8 months, there was no stone residuals or recurrences in the gallbladder and CBD, and no patient showed a recurrence of biliary colic. In addition, the gallbladder contractility function was proven to be normal within 3 to 6 months after the operation.

CONCLUSIONS

SOCS could successfully manage concomitant gallbladder stones and secondary CBD stones and precisely protect normal biliary function.

Endoscopic dissection of refractory pancreatic duct stricture via accessory pancreatic duct approach for concurrent treatment of anomalous pancreaticobiliary junction in aging patients

Background

Although endoscopic management of pancreatic strictures by dilation and stenting is well established, some high-grade strictures are refractory to conventional methods. Here, we report a novel technique via accessory pancreatic duct (APD) approach to simultaneously release chronic pancreatitis-associated pancreatic stricture and correct anomalous pancreaticobiliary junction (APBJ). Due to APBJ and stricture of proximal main pancreatic duct, the APD turned out to be compensatory expansion. The stiff stenosis was dissected along the axial of APD using needle-knife electrocautery or holmium laser ablation, and then the supporting stent was placed into the pancreatic body duct. By doing so, the outflow channels of pancreatic and biliary ducts were exquisitely separated.

Patients and methods

Two patients aged 69 and 71 years underwent stricture dissection and stent insertion for fluent drainage of pancreatic juice. The postoperative course was marked by complete abdominal pain relief and normal blood amylase recovery. In the first patient, wire-guided needle-knife electrocautery under fluoroscopic control was applied to release refractory stricture. The second patient was treated by SpyGlass pancreatoscopy-guided holmium laser ablation to lift pancreatic stricture.

Results

Plastic stents in APD were removed at 3 months after surgery, and magnetic resonance imaging at 6 months showed strictly normal aspect of the pancreatic duct.

Conclusion

Although both cases were successful without severe complications, we recommend this approach only for selected patients with short refractory pancreatic strictures due to chronic pancreatitis. In order to prevent severe complications (bleeding, perforation or pancreatitis), direct-view endoscopy-guided electrotomy needs to be developed.

[The role of poloxamer 188 for cord blood mononuclear cells into megakaryocytes cultivation and induction in three-dimensional WAVE Bioreactor]

目的

观察泊洛沙姆188（P188）对体外三维（3D）培养诱导脐血单个核细胞向巨核细胞分化的影响。

方法

将分离的脐血单个核细胞分别接种于细胞瓶和细胞培养袋中，后者采用WIGGENS摇床模拟生物反应器进行3D培养。在巨核细胞诱导培养基中加入P188体外培养14 d，观察细胞形态、计数细胞数并计算细胞存活率，采用流式细胞术观察巨核细胞表面标志表达情况。

结果

与采用传统的细胞培养瓶二维（2D）培养诱导巨核细胞相比，2D+P188培养组巨核系CD41⁺、CD41⁺/CD61⁺、CD61⁺细胞数明显增加（P值均<0.01）；在3D培养中加入P188，细胞体积变大，核形状不规则，胞质含紫红色颗粒，细胞分化更接近成熟。2D培养、3D培养及3D+P188培养组组间巨核细胞表面标志CD41、CD41/CD61、CD61表达水平差异有统计学意义（P值均<0.01）。LSD-t检验两两比较显示，与2D培养相比，3D培养诱导巨核细胞存活率及细胞数均降低（P值分别为0.018、0.027），3D+P188培养组细胞数、细胞存活率与2D和3D培养组比较差异均无统计学意义（P值均>0.05）。而3D培养组巨核细胞CD41/CD61表达水平为（36.30±1.27）%，高于2D培养组的（23.95±1.34）%（P=0.002），3D+P188培养组CD41/CD61表达水平更高[（59.45±1.20）%]。

结论

3D培养有利于巨核系祖细胞诱导分化，但细胞存活率低，加入P188，细胞生存状态好，且诱导效率更高。

Metal support effects in electrocatalysis at hexagonal boron nitride

A scanning electrochemical droplet cell technique has been employed to screen the intrinsic electrocatalytic hydrogen evolution reaction (HER) activity of hexagonal boron nitride (h-BN) nanosheets supported on different metal substrates (Cu and Au). Local (spatially-resolved) voltammetry and Tafel analysis reveal that electronic interaction with the underlying metal substrate plays a significant role in modulating the electrocatalytic activity of h-BN, with Au-supported h-BN exhibiting significantly enhanced HER charge-transfer kinetics (exchange current is ca. two orders of magnitude larger) compared to Cu-supported h-BN, making the former material the superior support in a catalytic sense.

Polycaprolactone nanofibres loaded with 20(S)-protopanaxadiol for in vitro and in vivo anti-tumour activity study

In this work, 20(S)-protopanaxadiol (PPD)-loaded polycaprolactone (PCL) nanofibres were successfully fabricated by the electrospinning technique using Tween 80 as a solubilizer. Firstly, smooth and continuous nanofibres were collected using suitable solvents and appropriate spinning conditions. Secondly, nanofibre mats were characterized by scanning electron microscopy, thermogravimetric (TG) analysis, Fourier transform infrared spectroscopy and mechanical testing. Finally, nanofibrous membranes were evaluated using water contact angle, in vitro drug release, biodegradation test, in vitro and in vivo anti-tumour activity and cell apoptosis assay. Scanning electron microscopic observations indicated that the diameter of the drug-loaded nanofibres increased with the increase of drug concentration. TG analysis and mechanical test showed that nanofibres were equipped with great thermal and mechanical properties. Biodegradation test exhibited that the structure of fabricated nanofibres had a certain degree of change after 15 days. An in vitro release study showed that PPD from drug-loaded nanofibres could be released in a sustained and prolonged mode. The cytotoxic effect of drug-loaded nanofibre mats examined on human laryngeal carcinoma cells (Hep-2 cells) demonstrated that the prepared nanofibres had a remarkable anti-tumour effect. Meanwhile, the drug-loaded fibre mats showed a super anti-tumour effect in an in vivo anti-tumour study. All in all, PCL nanofibres could be a potential carrier of PPD for cancer treatment.

Enhanced photocatalytic efficiency of C3N4/BiFeO3heterojunctions: the synergistic effects of band alignment and ferroelectricity

C₃N₄/BiFeO₃heterojunction shows enhanced visible light photocatalytic efficiency.

Optimal teaching strategy in periodic impulsive knowledge dissemination system

Accurately describing the knowledge dissemination process is significant to enhance the performance of personalized education. In this study, considering the effect of periodic teaching activities on the learning process, we propose a periodic impulsive knowledge dissemination system to regenerate the knowledge dissemination process. Meanwhile, we put forward learning effectiveness which is an outcome of a trade-off between the benefits and costs raised by knowledge dissemination as objective function. Further, we investigate the optimal teaching strategy which can maximize learning effectiveness, to obtain the optimal effect of knowledge dissemination affected by the teaching activities. We solve this dynamic optimization problem by optimal control theory and get the optimization system. At last we numerically solve this system in several practical examples to make the conclusions intuitive and specific. The optimal teaching strategy proposed in this paper can be applied widely in the optimization problem of personal education and beneficial for enhancing the effect of knowledge dissemination.

Genetic and epigenetic alterations induced by different levels of rye genome integration in wheat recipient

The narrow genetic variation present in common wheat (Triticum aestivum) varieties has greatly restricted the improvement of crop yield in modern breeding systems. Alien addition lines have proven to be an effective means to broaden the genetic diversity of common wheat. Wheat-rye addition lines, which are the direct bridge materials for wheat improvement, have been wildly used to produce new wheat cultivars carrying alien rye germplasm. In this study, we investigated the genetic and epigenetic alterations in two sets of wheat-rye disomic addition lines (1R-7R) and the corresponding triticales. We used expressed sequence tag-simple sequence repeat, amplified fragment length polymorphism, and methylation-sensitive amplification polymorphism analyses to analyze the effects of the introduction of alien chromosomes (either the entire genome or sub-genome) to wheat genetic background. We found obvious and diversiform variations in the genomic primary structure, as well as alterations in the extent and pattern of the genomic DNA methylation of the recipient. Meanwhile, these results also showed that introduction of different rye chromosomes could induce different genetic and epigenetic alterations in its recipient, and the genetic background of the parents is an important factor for genomic and epigenetic variation induced by alien chromosome addition.

Cross-leg repair of large soft-tissue defects in distal sites of the feet by distally based neuro-fasciocutaneous flaps with perforating vessels

The objective of this study was to introduce a method for repairing large soft-tissue defects on the foot. Distally based neuro-fasciocutaneous flaps with perforating vessels were designed along the saphenous and sural neurovascular axes. The cutaneous perforating branches of the major arteries of the lower extremities were used as pedicles, which provided a rotation arc for the cross-leg flap to cover the large-sized soft-tissue defects on the foot. We transferred 6 neurocutaneous vascular axial flaps, including 4 saphenous neurocutaneous axial flaps (ranging from 25 x 13 to 17 x 9 cm in area) with posterior tibial perforators as the pedicle, and 2 sural neurocutaneous axial flaps (ranging from 29 x 12 to 18 x 7 cm in area) supplied by the perforating branches of the peroneal vessels. These 6 cases of neuro-fasciocutaneous flaps survived with satisfactory cosmetic appearances and functional results on follow-up at 8 to 17 months post-surgery. Placing a distally based neuro-fasciocutaneous cross-leg flap with perforating vessels is an effective method for repairing large-sized soft-tissue defects on the foot.

Double-loop locking cross-stitch suture and suspension fixation for medial collateral ligament origin reconstruction

The purpose of this study was to summarize the clinical application and results of the double-loop locking cross-stitch suture and suspension fixation method for medial collateral ligament origin reconstruction. Thirty-six patients (21 males, 15 females) with an average age of 40 years (range = 17-58 years), who underwent treatment for acute fracture of the medial collateral ligament at our hospital from February 2008 to May 2009, were included in this study. All patients presented unilateral injuries (17 right-sided, 19 left-sided) and underwent repair with the double-loop locking cross-stitch suture and suspension fixation method. All incisions in this group of patients healed by first intention. Thirty-two patients were followed up for 6-20 months (average = 12 months). There were no reports of wound infection, ligament re-fracture or other complications in the follow-up period. Based on the Lysholm knee-scoring scale, the patients received a 100% excellent and good rating (20 patients - excellent score, 12 patients - good score) postoperatively. The advantages of the double-loop locking cross-stitch suture and suspension fixation method are a smaller incision, reliable fixation, and early restoration of knee joint stability. It is, therefore, an effective and low-risk method for the reconstruction of medial collateral ligament origin.

Early decrease in carotid plaque lipid content as assessed by magnetic resonance imaging during treatment of rosuvastatin

Background

Statin therapy has shown to deplete atherosclerotic plaque lipid content and induce plaque regression. However, how early the plaque lipid depletion can occur with low-density lipoprotein cholesterol (LDL-C) lowering in humans in vivo has not been fully described.

Methods

We enrolled 43 lipid treatment naïve subjects with asymptomatic carotid atherosclerosis and LDL-C ≥ 100 and ≤ 250 mg/dl. Rosuvastatin 5–20 mg/day was used to lower LDL-C levels to < 80 mg/dl. Lipid profile and carotid MRI scans were obtained at baseline, 3, 12, and 24 months. Carotid plaque lipid-rich necrotic core (LRNC) and plaque burden were measured and compared between baseline and during treatment.

Results

Among the 32 subjects who completed the study, at 3 months, an average dose of rosuvastatin of 11 mg/day lowered LDL-C levels by 47% (125.2 ± 24.4 mg/dl vs. 66.7 ± 17.3 mg/dl, p < 0.001). There were no statistically significant changes in total wall volume, percent wall volume or lumen volume. However, LRNC volume was significantly decreased by 7.9 mm³, a reduction of 7.3% (111.5 ± 104.2 mm³ vs. 103.6 ± 95.8 mm³, p = 0.044). Similarly, % LRNC was also significantly decreased from 18.9 ± 11.9% to 17.9 ± 11.5% (p = 0.02) at 3 months. Both LRNC volume and % LRNC continued to decrease moderately at 12 and 24 months, although this trend was not significant.

Conclusions

Among a small number of lipid treatment naïve subjects, rosuvastatin therapy may induce a rapid and lasting decrease in carotid plaque lipid content as assessed by MRI.

Trial registration

ClinicalTrials.Gov numbers NCT00885872

First Report of Streptomyces galilaeus Associated with Common Scab in China

During a survey of potato scab pathogens in China from 2003 to 2012, a new pathogen was found in Shanxi and Neimenggu provinces. The incidence was approximately 20% of all recovered strains. The lesions caused by the pathogen were slightly raised and similar to those caused by Streptomyces scabies (3). Lesions were excised (approximately 10 mm³) from 40 infected tubers, surface-disinfested with 0.3% NaOCl for 30 s, rinsed in sterile water three times, cut into 5 mm³, then sliced into 1-mm pieces, and plated on water agar amended with ampicillin (50 μg/ml). Plates were incubated at 28°C in the dark for 4 days. The spores of Streptomyces sp. strains growing from the tuber pieces were collected from single bacterial colonies and cultured on oatmeal agar. To fulfill Koch's postulates, one strain, CPS-2, was grown at 28°C for 10 days and the spores were washed from the plates as inoculum. One hundred milliliters of inoculum (1 × 10⁵ CFU/ml) was mixed with autoclaved soil and vermiculite (1:1) in each pot (15 cm in diameter). Cut tubers were planted in the pots (potato cv. Favorita, one plant per pot, five replicates) and grown under greenhouse conditions (22 ± 5°C). Typical common scab symptoms consisting of small, brown, raised lesions developed on potato tubers 12 weeks after planting. The same strain was re-isolated from the lesions of the new scabby tubers. Non-inoculated plants, treated as described above, but without strain CPS-2, remained healthy. The CPS-2 strain was identified based on morphological and physiological characterization and 16S rDNA sequence. On yeast-malt extract agar, the test strain produced grayish-white aerial hypha, reddish brown substrate mycelium and pigments, and loose spiral spore chains. Spores were smooth and were 0.8 to 0.9 × 1.1 to 1.2 μm in size (diameter and length). The ability of the strain to use single sources of carbon and nitrogen was verified according to the International Streptomyces project (4). The strain grew in media supplemented with L-arabinose, D-fructose, D-glucose, rhamnose, raffinose, meso-inositol, sucrose, and D-xylose, but not D-mannitol. It used L-hydroxyproline, L-methionine, and L-histidine, and produced melanin on tyrosine and peptone yeast extract agar. The strain did not grow at a pH less than 5.0 and was sensitive to streptomycin (20 μg/ml), phenol (0.1%), and crystal violet (0.5 μg/mL), but not to penicillin (10 IU/ml). The strain also produced hydrogen sulfide. The biological characteristics of strain CPS-2 were in accord with Streptomyces galilaeus. CPS-2 produced thaxtomin A in oatmeal liquid medium and the txt AB gene fragment was successfully amplified using specific primers (2). The 16S rDNA sequence of CPS-2 was amplified by PCR with primers 16S1-F: 5'-CATTCACGGAGAGTTTGATCC-3' and 16S1-R: 5'-AGAAAGGAGGTGATCCAGCC-3' (1) and sequenced. A BLAST search of the 16S rDNA sequence for CPS-2 was conducted using the NCBI GenBank database, resulting in 99.8% similarity to S. galilaeus (NR_040857). The 16S rDNA sequence for CPS-2 (1,388 bp) was deposited in GenBank (AY621378). To our knowledge, this is the first report of S. galilaeus causing common scab of potato in China. References: (1) R. A. Bukhalid et al. Appl. Environ. Microbiol. 68:738, 2002. (2) R. Flores-González et al. Plant Pathol. 57:162, 2008. (3) D. H. Lambert and R. Loria. Int. J. Syst. Bacteriol. 39:387, 1989. (4) E. B. Shirling and D. Gottlieb. Int. J. Syst. Bacteriol. 16:313, 1966.

First Report of Alternaria alternata Causing Blight on Zanthoxylum piperitum in China

Since 2009, brown leaf spot and panicle blight of Zanthoxylum piperitum (L.) DC. ("liujin," commonly known as Japanese pepper and Japanese pricklyash) has been observed on 40% of the plants in the test field of Foresty Academy of Science in Hebei Province of China. When symptoms formed on leaves, a thick yellow spot appeared, which then turned brown. When on the spikes, brown lesions were observed initially on the grain, which then spread down to fruit stem, and finally the whole spike wilted and dried up. Yield and quality losses were considerable. A fungus was isolated consistently from the diseased tissues using potato dextrose agar (PDA) (1). Three representative isolates were chosen for further characterization. All the isolates grew at 28°C on PDA and potato carrot agar (PCA) medium. Fungal colonies were initially white, then became olivaceous with some white mycelium on the top of the colony, and turned brown with age. When observed with the microscope, crineous septate hypha appeared, and conidiophore peduncles were upright or slightly curved, with a few branches, 33.0 to 75.0 μm long and 4.0 to 5.5 μm wide. Conidia were crineous short clubs or near oval in shape, 22.5 to 40.0 μm long and 8.0 to 13.5 μm wide, with a short conical beak, and had one to four longitudinal cross walls. On PCA, condia had three to seven transepta and one to five longisepta, and were produced in a branched, long chain with more than five conidia. The pathogen was identified based on morphological characteristics as Alternaria alternata (Fr.:Fr.) Keissl. (3). DNA was extracted from mycelium and PCR was performed on the internal transcribed spacer (ITS) region with primers ITS1 and ITS4. A 570-bp fragment was amplified and sequenced (GenBank Accession No. JQ973810). BLASTn analysis revealed there was 100% sequence identity with A. alternata strains (GU566303 and GQ121322). To further identify the fungus, A. alternata species-specific primers AAF2/AAR3 (2) were used to generate an amplicon which was then sequenced (JX308287). Sequence comparison showed there was 100% sequence identity with A. alternata (JQ927300 and JQ907485). Pathogenicity tests were performed by spraying with a cultured suspension (10⁶ spores/ml) of approximately 100 μl onto healthy leaves in 15-cm-diameter glass dishes containing sterilized filter paper soaked with sterilized water at room temperature. Control plants were inoculated with sterile distilled water. Ten days after inoculation, symptoms were observed in all inoculated leaves and appeared to be identical to those observed in the field. No symptoms were noted on the control leaves. Identical results were also obtained when spikes were inoculated. The fungi reisolated from symptomatic plants were A. alternata. To our knowledge, this is the first report of A. alternata causing leaf spots and panicle blight of Z. piperitum in China. References: (1) O. D. Dhingra and J. B. Sinclair. Basic Plant Pathology Methods. CRC Press, Boca Raton, FL, 1995. (2) P. Konstantinova. et al. Mycol. Res. 106:23, 2002. (3) T. Y. Zhang. China fungi records (Alternaria) (Volume 16) (in Chinese). Beijing: Science Press, 2003.

First Report of Peanut Pod Rot Caused by Neocosmospora vasinfecta in Northern China

From 2006 to 2010, peanut (Arachis hypogaea) pod rot became more prevalent in northern China, especially in the Sha River drainage area. The incidence of pod rot ranged from 30 to 100%. Typical symptoms were black rot of the pods, but no obvious morphological abnormality of the aboveground parts of infected plants was observed. Brown or black spots appeared on many pods when initially infected and then all peanut pods became black and rotten. The same fungus was isolated from 54 surface-disinfested lesions (85.2% of all lesions) on potato dextrose agar (PDA) media. One isolate, designated as HBXLb, was chosen for further characterization. In culture, both anamorph and teleomorph were present. Mycelia of the fungus grew quickly (colonies were 3.2 cm in diameter in 3 days) and became white and floccose on PDA at 28°C. The hyaline, elongated-to-cylindrical conidia aggregated on the slimy heads of conidiogenous cells that developed on undifferentiated hyphae after incubation for 3 to 4 days. Conidial sizes varied from 5 to 10 × 1.5 to 3 μm (n = 50) and were mostly single celled. Some conidia appeared slightly curved. The morphology was consistent with Acremonium spp. Numerous ascomata (perithecia) formed within 10 to 14 days when incubated at 28°C under light and dark conditions. Perithecia were orange-brown, strawberry shaped (300 to 400 μm in diameter), and ostiolate on the top. Cylindrical asci, with an average size of 90 to 110 × 7.5 to 9 μm, were present inside the ascomata with each containing eight ascospores in a row. The ascospores were brownish, spherical to ellipsoidal, and 10 to 15 × 8 to 12 μm. The cultural and morphological characteristics of isolate HBXLb matched the description of N. vasinfecta (2). The internal transcribed spacer (ITS) region of rDNA was amplified by the primer pairs ITS4/ITS5. A 525-bp amplicon (ITS4-5.8s-ITS5) was obtained and sequenced (GenBank Accession No. HM461901). The ITS sequence was a 100% match to N. vasinfecta strain N-JXLN01 (GenBank Accession No. GU213063) by BLASTn in GenBank. Pathogenicity tests were conducted on detached pods of peanut cultivar Jihua 4. Forty surface-disinfested peanut pods were soaked in a conidial suspension (10⁵ conidia per ml) for 2 min and 40 pods were soaked in sterile water as a control. Then all peanut pods were maintained in moist petri dishes under darkness for 14 days at 28°C. Brown or black spots appeared on all pods inoculated with the fungus within 10 days, while the controls remained healthy. Symptoms were similar to those originally observed in the field, and N. vasinfecta could be reisolated from all infected pods. This fungus previously has been reported as the pathogen of foot rot of peanut in South Africa (1), Taiwan (4), and Australia (3). To our knowledge, this is the first report of peanut pod rot caused by N. vasinfecta in China. References: (1) S. W. Baard et al. Phytophylactica 17:49, 1985. (2) O. A. Cornely et al. Emerg. Infect. Dis. 7:149, 2001. (3) M. F. Fuhlbohm et al. Australas. Plant Dis. Notes 2:3, 2007. (4) J. W. Huang et al. Plant Pathol. Bull. 1:203, 1992.

First Report of Neocosmospora striata Causing Peanut Pod Rot in China

In 2008, an outbreak of pod rot of peanut (Arachis hypogaea L.) occurred on most of the peanut cultivars in the Old Yellow River drainage area, the largest peanut-growing region in China. Disease incidence reached as high as 90% in some fields, causing severe yield losses. The black rot of pods and blackened, nonrotting taproots is similar to symptoms of peanut black rot caused by Cylindrocladium parasiticum, but the reddish orange perithecia of C. parasiticum were not found on the taproots close to the surface of the soil. The foliage of affected plants was generally asymptomatic, but some plants turned greener. This pod rot disease was further investigated in 2008 and 2010. Twenty-three Fusarium-like isolates were obtained from symptomatic, surface-disinfested pods with a frequency of 82%. These isolates were fast growing, with flat, thin, and grayish white colonies when cultured on potato dextrose agar (PDA) at 28°C for 3 to 4 days. The hyaline, elongated to cylindrical conidia, aggregated in slimy heads on conidiogenous cells developed from undifferentiated hyphae when observed with the light microscope. The size of conidia (single celled or one septum) varied from 3 to 9 μm long and 1.5 to 3.5 μm wide on the basis of the measurement of 50 spores. Some conidia appeared slightly curved. Ascomata formed within 10 to 14 days, with a punctate appearance on the colony. The cerebriform ascomata were dark brown, pyriform, ostiolate, glabrous, 120 to 170 × 90 to 130 μm, and with necks 30 to 50 μm long. Asci measured 60 to 90 × 6 to 10 μm, were cylindrical to cylindric-clavate, thin walled, and had an apical ring. Ascospore arrangement was obliquely uniseriate or partially biseriate, very pale yellow to hyaline, ellipsoidal, and measured 8 to 12 × 4.5 to 6 μm. Some spores had a median transverse straight or curved septum and were slightly constricted at the septum, with 6 to 10 thin, transverse, hyaline flanges. Morphological characteristics of the isolates with ascomata dark brown and ascospores with 6 to 10 transverse hyaline flanges matched the description for Neocosmospora striata (1). The internal transcribed spacer (ITS) region of rDNA was amplified from extracted template DNA with primer pairs ITS4/ITS5 and sequenced. A 591-bp amplicon (GenBank Accession No. HM461900) had 99% sequence identity with Fusarium solani (HQ607968 and HQ608009) and N. vasinfecta (GU213063), which indicated that these fungi belong to the genus Neocosmospora or Fusarium, although there is no direct sequence evidence that they are N. striata. N. striata has only been previously reported in Japan (2). This species is unique because of the dark brown ascomata and there is no comparable species (1). Koch's postulates were completed by surface-disinfesting 80 peanut pods of cv. Jihua 9813 and soaking them in conidial suspensions (10⁵ conidia/ml) for 2 min. Another 80 other pods soaked in sterile water served as controls. All peanuts were incubated in moist petri dishes under darkness at 28°C. Symptoms similar to those originally observed in the field formed within 10 days on all inoculated peanut pods and not the controls. N. striata was reisolated from all affected peanut pods. To our knowledge, this is first report of N. striata causing peanut pod rot in China and the first description of the anamorph of the fungus. References: (1) P. F. Cannon et al. Trans. Br. Mycol. Soc. 82:673, 1984. (2) S. Udagawa et al. Trans. Mycol. Soc. Jpn. 16:340, 1975.

Role of microRNA-214-targeting PTEN in advanced glycation endproducts-induced apoptosis delay of monocytes (89.35)

Advanced glycation endproduct(AGE) delays spontaneous apoptosis of human monocytes and contributes to the development of a local inflammatory response. The mechanism by which AGEs effect monocyte apoptosis, however, is unclear. Here we report that AGE-modified BSA and β2-microglobulin(β2m) can increase miR-214 expression in monocytes, which in turn, enhances cell survival by reducing the expression of phosphatase and tensin homolog(PTEN). Employing miRNA microarray, we obtains a genome-wide miRNA expression profiling of THP-1 cells treated with/without AGEs. Among 470 miRNAs screened, 6 miRNAs including miR-214 are upregulated while 5 miRNAs were down-regulated (fold-change&gt;2) in AGE-treated cells. AGE-induced miRNA differential expression is validated by miRNA qRT-PCR. Significant upregulation of miR-214 is confirmed in normal human monocytes treated with AGEs and monocytes isolated from patients with chronic renal failure. Both AGE-treated monocytes and patient monocytes have a delayed apoptosis. Luciferase reporter assay shows that miR-214 targets PTEN mRNA 3’-untranslated region. Furthermore, PTEN expression is inversely correlated with miR-214 expression in monocytes and the forced expression of miR-214 leads to a delayed apoptosis of THP-1. In contrast, decrease of miR-214 expression via anti-miR-214 largely abolishes AGE-induced cell survival. In summary, our findings define a new regulation role of miR-214 on AGE-induced monocyte survival by impeding PTEN expression.

Seedling and Slow Rusting Resistance to Leaf Rust in Chinese Wheat Cultivars

Identification of resistance genes is important for developing leaf rust resistant wheat (Triticum aestivum) cultivars. A total of 102 Chinese winter wheat cultivars and advanced lines were inoculated with 24 pathotypes of Puccinia triticina for postulation of leaf rust resistance genes effective at the seedling stage. These genotypes were also planted in the field for characterization of slow rusting responses to leaf rust in the 2006-07 and 2007-08 cropping seasons. Fourteen leaf rust resistance genes-Lr1, Lr2a, Lr3bg, Lr3ka, Lr14a, Lr16, Lr17a, Lr18, Lr20, Lr23, Lr24, Lr26, Lr34, and LrZH84-either singly or in combinations, were postulated in 65 genotypes, whereas known resistance genes were not identified in the other 37 accessions. Resistance gene Lr26 was present in 44 accessions. Genes Lr14a and Lr34 were each detected in seven entries. Lr1 and Lr3ka were each found in six cultivars, and five lines possessed Lr16. Lr17a and Lr18 were each identified in four lines. Three cultivars were postulated to possess Lr3bg. Genes Lr20, Lr24, and LrZH84 were each present in two cultivars. Each of the genes Lr2a and Lr23 may exist in one line. Fourteen genotypes showed slow leaf rusting resistance in two cropping seasons.

Uncoupling protein-2 negatively regulates polymorphonuclear leukocytes chemotaxis via modulating [Ca2+] influx

OBJECTIVE

Previous studies demonstrated that uncoupling protein 2 (UCP2) plays a negative role in modulating leukocyte inflammatory responses. The mechanism underneath the role of UCP2 in modulating leukocyte inflammatory responses, however, is incompletely understood. Here, we investigated the effect of UCP2 in polymorphonuclear leukocyte (PMN) chemotaxis.

METHODS AND RESULTS

First, we assessed PMN chemotaxis in zymosan-induced murine peritonitis and found that UCP2(-/-) mice had significantly more migrated PMN in peritoneal lavage compared to their wild-type littermates. In vitro transmigration assays using isolated PMN also showed that PMN from UCP2(-/-) mice migrated faster than those from wild-type mice in response to N-formyl-methionyl-leucyl-phenylalanine (fMLP). Second, in supporting an inhibitory role of UCP2 in PMN transmigration, migrated PMN had a decreased UCP2 expression compared to nonmigrated PMN. In contrast, in streptozotocin-induced diabetic mice in which UCP2 expression was enhanced, PMN chemotaxis was reduced. Third, comparing to UCP2(+/+) PMN, UCP2(-/-) PMN had a stronger upregulation of fMLP-induced surface CD11b/CD18 and CD11a/CD18. Finally, UCP2(-/-) PMN showed a quicker and larger fMLP-triggered intracellular calcium mobilization compared to UCP2(+/+) PMN.

CONCLUSIONS

Our study demonstrates that UCP2 serves as a brake in controlling PMN chemotaxis and that the effect of UCP2 on PMN chemotaxis may be through modulating calcium influx.

Visfatin stimulates production of monocyte chemotactic protein-1 and interleukin-6 in human vein umbilical endothelial cells

Monocyte chemotactic protein-1 and interleukin-6 are important inflammatory cytokines, which have close relationships with atherosclerosis. Visfatin is a novel adipokine involved in regulation of inflammatory cytokines, however, associations of visfatin with cytokines (MCP-1, IL-6) in human umbilical vein endothelial cells are unclear. The aim of this study was to determine whether visfatin has effects on the expression of MCP-1 and IL-6 in human umbilical vein endothelial cells. Enzyme-linked immunosorbent assay were used for measuring MCP-1 and IL-6 production in human umbilical vein endothelial cells. Real-time quantitative reverse-transcription polymerase chain reaction was used for determining MCP-1 and IL-6 mRNA expression. For the pathway determination following inhibitors were used: wortmannin [phosphatiylinositol 3-kinase (PI3K)], SB203580 [p38 mitogen-activated protein kinase (MAPK)], PD98059 [extracellular signal-regulated kinase (ERK) 1/2)], JNK inhibitor II [c-Jun NH 2-terminal kinase (JNK)]. We demonstrated that visfatin could obviously upregulate secretion of MCP-1and IL-6 in a dose- and time-dependent manner in human umbilical vein endothelial cells. Visfatin-induced effects were diminished by SB203580, wortmannin, and PD98059. In summary, these results suggest that visfatin-induced MCP-1 and IL-6 production involve p38 MAPK, PI3K, and ERK 1/2 pathways in human umbilical vein endothelial cells as determined by inhibition with specific inhibitors.

The heparan sulfate proteoglycan form of epithelial CD44v3 serves as a CD11b/CD18 counter-receptor during polymorphonuclear leukocyte transepithelial migration

Leukocyte beta2-integrin CD11b/CD18 mediates the firm adhesion and subsequent transepithelial migration of polymorphonuclear leukocytes, but the identity of its counter-receptor(s) on epithelia remains elusive. Here we identified a monoclonal antibody, clone C3H7, which strongly bound to the basolateral membranes of epithelial cells and inhibited both the adhesion of epithelial cells to immobilized CD11b/CD8 and the transepithelial migration of PMNs in a physiologically relevant basolateral-to-apical direction. C3H7 antigen expression in epithelial monolayers was significantly increased by treatment with proinflammatory cytokine interferon-gamma or a combination of interferon-gamma and tumor necrosis factor-alpha. Up-regulation of C3H7 antigen was also observed in the epithelium of inflamed human colon tissues. Microsequencing and Western blotting of the purified antigen showed it to be CD44 variant 3 (CD44v3), a approximately 160-kDa membrane glycoprotein. Further studies demonstrated that this epithelial CD44v3 specifically binds to CD11b/CD18 through its heparan sulfate moieties. In summary, our study demonstrates for the first time that the heparan sulfate proteoglycan form of epithelial CD44v3 plays a critical role in facilitating PMN recruitment during inflammatory episodes via directly binding to CD11b/CD18.

First Report of Potato Scab Caused by Streptomyces turgidiscabies in China

Potato scab, caused by several plant pathogenic Streptomyces species, is known to occur in potato-planting areas worldwide. Symptoms of disease on potato tubers are shallow, raised, or pitted corky lesions (2). In 1998, Streptomyces turgidiscabies was reported as a new potato scab pathogen from Hokkaido, Japan (3). Potato scab has been observed in many potato-cultivation areas in China and incidence of the disease was approximately 6 to 10% in some fields in 2006 (in our survey). To investigate the casual agent of scab disease, isolations were made from scabby potato tubers collected from different areas using oatmeal agar. Identification of an isolate from Shaanxi Province was based on morphological and physiological characterization followed by 16S rRNA confirmation. Characteristics were gray, aerial hypha, rectiflexuous spore chains, a smooth spore surface, and spores that were 0.5 to 0.7 × 1.0 to 1.2 μm. The strain did not produce melanin on tyrosine-peptone-yeast extract agar media, did not produce diffusible pigments, used all the International Streptomyces Project (ISP) sugars (4) as single carbon sources, used l-hydroxyproline, l-tyrosine, and l-histidine as single nitrogen sources but not l-methionine, grew at pH 4.5, was susceptible to streptomycin (20 μg ml^-1), phenol (0.1%), and penicillin (10 IU ml^-1) but not to crystal violet (0.5 μg ml^-1), and produced H₂S. The identification was confirmed by comparison of its 16S rRNA sequence with the GenBank database using the BLAST program. The 16S rRNA sequence was amplified by PCR with primers S1: 5'-CATTCACGGAGAGTTTGATCC-3' and S2: 5'-AGAAAGGAGGTGATCCAGCC-3' and sequenced. BLASTn analysis of the sequence obtained showed the highest similarity (99.9%) with S. turgidiscabies type strain ATCC 700248 (GenBank Accession No. AB026221). The sequence was submitted to GenBank (Accession No. AM889495). Pathogenicity of the strain was tested in the greenhouse on potato tubers of cv. Favorita grown in pots (one plant per pot, three replicates). One hundred milliliters of inoculum (1 × 10⁵ CFU ml^-1) of the strain was mixed with sterile soil and vermiculite (1:1) in each pot. Potato plants were grown at 25°C and the soil was allowed to dry between waterings. The immature potato tubers were used to evaluate scab symptoms 10 weeks after planting. All tubers inoculated with the pathogen developed typical common scab symptoms consisting of erumpent, brown, corky lesions, which is different from the symptoms caused by S. reticuliscabiei (1). The noninoculated control tubers did not show scab symptoms. S. turgidiscabies was reisolated from lesions of diseased immature tubers. The pathogenicity test indicates that S. turgidiscabies caused scab disease on potato tubers. To our knowledge, this is the first report of S. turgidiscabies causing potato scab disease in China. References: (1) K. Bouchek-Mechiche et al. Int. J. Syst. Evol. Microbiol. 56:2771, 2006. (2) R. Loria et al. Plant Dis. 81:836, 1997. (3) K. Miyajima et al. Int. J. Syst. Bacteriol. 48:495, 1998. (4) E. B. Shirling and D. Gottlieb. Int. J. Syst. Bacteriol. 16:313, 1966.

Molecular mapping of leaf rust resistance gene LrZH84 in Chinese wheat line Zhou 8425B

Leaf rust, caused by Puccinia triticina, is one of the most widespread diseases in common wheat (Triticum aestivum L.) worldwide. With the objective of identifying and mapping new genes for resistance to leaf rust, F(1), F(2) plants and F(3) lines from a cross between resistant line Zhou 8425B and susceptible line Chinese Spring were inoculated with Chinese P. triticina races THTT and MBHP in the greenhouse. A total of 793 pairs of SSR primers were used to test the parents and resistant and susceptible bulks. Seven polymorphic chromosome 1B markers were used for genotyping the F(2) and F(3) populations. Zhou 8425B carried a single dominant resistance gene, temporarily designated LrZH84, linked to SSR markers gwm582 and barc8 with genetic distances of 3.9 and 5.2 cM, respectively. The Xbarc8 allele co-segregated with Lr26 in the F(3) population. The Xgwm582 allele associated with LrZH84 was identified as a leaf rust resistance gene and shown to be present in the Predgornaia 2 parent of Zhou 8425B. The seedling reaction pattern of LrZH84 was different from those of lines with Lr26, Lr33, Lr44 and Lr46, all of which are located in chromosome 1B. It was concluded that LrZH84 is likely to be a new leaf rust resistance gene.

Role of junctional adhesion molecule-like protein in mediating monocyte transendothelial migration

OBJECTIVE

Monocyte migration across the vascular endothelium of blood vessels is a key early event in atherosclerosis. The mechanisms underlying monocyte transendothelial migration (TEM), however, are still not completely understood. Here we studied the role of junctional adhesion molecule-like protein (JAML) in regulating monocyte TEM.

METHODS AND RESULTS

Firstly, by Western blot and flow cytometry, we showed that JAML was strongly expressed in monocytes and monocyte surface expression of JAML was upregulated by monocyte chemotaxis protein-1 stimulation. Both monocyte adhesion to and migration across tumor necrosis factor-alpha (TNFalpha) preactivated human microvascular endothelial cell (HMEC-1) monolayers were dose-dependently reduced by anti-JAML antiserum or soluble extracellular JAML recombinant. Secondly, short-term exposure of human monocytes and THP-1 cells to advanced glycation end products increased cell surface JAML expression, which was correlated with enhanced cell adhesion and TEM. In contrast, knockdown of JAML in THP-1 monocytes decreased both adhesion and transmigration of THP-1 monocytes. Finally, direct binding assay of the soluble JAML to HMEC-1 monolayers suggested that endothelial coxsackie and adenovirus receptor (CAR) may serve as one of the ligands for JAML.

CONCLUSIONS

Monocytic JAML plays a critical role in regulating monocyte TEM probably via binding to the endothelial CAR and other tight junction-associated adhesive molecules.

Signal regulatory protein alpha negatively regulates beta2 integrin-mediated monocyte adhesion, transendothelial migration and phagocytosis

BACKGROUND

Signal regulate protein alpha (SIRPalpha) is involved in many functional aspects of monocytes. Here we investigate the role of SIRPalpha in regulating beta(2) integrin-mediated monocyte adhesion, transendothelial migration (TEM) and phagocytosis.

METHODOLOGY/PRINCIPAL FINDINGS

THP-1 monocytes/macropahges treated with advanced glycation end products (AGEs) resulted in a decrease of SIRPalpha expression but an increase of beta(2) integrin cell surface expression and beta(2) integrin-mediated adhesion to tumor necrosis factor-alpha (TNFalpha)-stimulated human microvascular endothelial cell (HMEC-1) monolayers. In contrast, SIRPalpha overexpression in THP-1 cells showed a significant less monocyte chemotactic protein-1 (MCP-1)-triggered cell surface expression of beta(2) integrins, in particular CD11b/CD18. SIRPalpha overexpression reduced beta(2) integrin-mediated firm adhesion of THP-1 cells to either TNFalpha-stimulated HMEC-1 monolayers or to immobilized intercellular adhesion molecule-1 (ICAM-1). SIRPalpha overexpression also reduced MCP-1-initiated migration of THP-1 cells across TNFalpha-stimulated HMEC-1 monolayers. Furthermore, beta(2) integrin-mediated THP-1 cell spreading and actin polymerization in response to MCP-1, and phagocytosis of bacteria were both inhibited by SIRPalpha overexpression.

CONCLUSIONS/SIGNIFICANCE

SIRPalpha negatively regulates beta(2) integrin-mediated monocyte adhesion, transendothelial migration and phagocytosis, thus may serve as a critical molecule in preventing excessive activation and accumulation of monocytes in the arterial wall during early stage of atherosclerosis.

First Report of Cercospora concors Causing Cercospora Leaf Blotch of Potato in Inner Mongolia, North China

Cercospora leaf blotch disease of potato (Solanum tuberosum L.) caused by Cercospora concors (Casp.) Sacc (synonym Mycovellosiella concors (Casp.) Deighton) occurs worldwide but mainly has been reported in the cool and temperate climates of Europe, Asia, North America, and eastern Africa. Cercospora leaf blotch is usually a minor disease and may go unnoticed since it commonly occurs simultaneously with other potato leaf diseases such as late blight (caused by Phytophthora infestans) and early blight (caused by Alternaria solani) (2). Symptoms of Cercospora leaf blotch first appear on lower leaves as small, yellowish green, irregular blotches and later may appear on middle and upper leaves. As the leaves expand, the blotches enlarge and become purplish brown or black. Conidiophores and conidia form on the underside of the lesions, giving the lesions a mildewed appearance similar to late blight. Necrotic lesions are distinguished from those caused by the early blight pathogen A. solani by the lack of concentric rings (1). In more severe epidemics of Cercospora leaf blotch, potato leaves may be killed, stem lesions become dark and entire plants die, but no resulting yield loss from the disease has been documented. Potato tubers are not infected. From August to September of 2005, yellow-brown lesions appeared on the upper side of potato leaves (cv. Zihuabai, certified virus free) and gray mildew developed on the underside of leaves in potato field trials conducted in Jining County, 41°N, 113°E of Inner Mongolia, North China. The infections were observed mostly on lower and middle leaves of plants; 20 to 30% of plants were infected. In the laboratory, the mildew was scraped with a sterile scalpel and examined microscopically. The conidiophores were irregular in width, grayish, and highly branched. The conidia were numerous, light to dark, straight or slightly bent, cylindrical or obclavate, with conspicuous scars, and zero to six septa. The mature spores were from 16 to 59 μm long and 4 to 6 μm wide. The teleomorph of the fungus was not found. On the basis of the morphological characters, the causal agent was identified as C. concors. C. concors has been previously identified from potato leaves in the Engshi District of Hubei Province, China (3), but to our knowledge, this is the first report of the fungus causing Cercospora leaf blotch of potato in Inner Mongolia, North China. References: (1) G. D. Franc and B. I. Christ. Page 22 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. American Phytopathological Society, St. Paul, MN, 2001. (2) E. R. French. Page 19 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. American Phytopathological Society, St. Paul, MN, 2001. (3) S. M. Tian et al. China Potato J. 1:13, 1997.

[Molecular typing of Neisseria meningitidis serogroup C strains with pulsed field gel electrophoresis in China]

OBJECTIVE

To study the characteristics of epidemiology and molecular typing on Neisseria meningitidis serogroup C strains associated with outbreaks of Anhui province and sporadic cases in China, using pulsed field gel electrophoresis (PFGE).

METHODS

212 Neisseria meningitidis serogroup C strains were isolated from invasive meningococcal cases, close contacts and healthy carriers, including 48 strains from Anhui province with 38 strains associated with serogroup C outbreaks. PFGE were performed by genomic DNA digestion with Nhe I restriction enzyme. The results of PFGE were analyzed by BioNumerics software (Version 4.0, Applied Maths BVBA, Belgium).

RESULTS

A total number of 212 Neisseria meningitidis serogroup C isolates were typed by 43 patterns, named AH1 to AH43. In China, AH1 pattern was the major PFGE pattern with 69.3% (n = 147) of all strains, distributed in 11 provinces. Three types of PFGE patterns (AH1 to AH3) were found in 48 strains from Anhui province, in which, 93.8% (n = 45) belonged to AH1. 97.4% (n = 37) of 38 strains associated with serogroup C outbreaks in Anhui province showed AH1 pattern. A total of 53 serogroup C strains were isolated from invasive meningococcal cases with 67.9% (36/53) of AH pattern. 71.9% (87/121) of serogroup C strains isolated from contacts of invasive meningococcal cases was AH1 pattern and 63.2% (24/38) of the strains from healthy carriers showed AH1 pattern.

CONCLUSION

By PFGE typing and analysis, AH1 pattern of Neisseria meningitidis serogroup C strains was proved to be the main clone which causing the outbreaks in Anhui province and might be responsible for the sporadic serogroup C meningococcal disease epidemics else where in the country.

Gelatinolytic activity of matrix metalloproteinase-2 and matrix metalloproteinase-9 in rat brain after implantation of 9L rat glioma cells

The matrix metalloproteinases (MMPs) have come to be highlighted by their close relation to the cell invasion of gliomas. The inhibitors of MMPs have undergone extensive development because of its effectiveness against tumor invasion and angiogenesis. Therefore, a suitable animal model is necessary for searching new MMPs inhibitors against gliomas. In this study, we established an experimental model by implanting 9L glioma cells stereotactically into Fisher344 (F344) rat's brain, and the expression and enzymatic activity of MMP-2 and MMP-9 in 9L glioma cells and in tumor tissue was determined by means of reverse transcription polymerase chain reaction (RT-PCR), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) zymography, in situ film zymography and immunostaining. The results of RT-PCR showed that the mRNA level of MMP-2 in 9L glioma cells was higher than that of MMP-9, and the mRNA expression of MMP-9 was increased along with the growth of malignant gliomas. SDS-PAGE zymography revealed that the expression of MMP-2 and MMP-9 were significantly increased in tumor tissues, and the MMP-9 wasn't detected in normal tissue. The positive stain of MMP-2 and MMP-9 was enhanced with the growth of malignant gliomas, especially for MMP-9. The expression of active gelatinase was found in tumor tissue. In conclusion, the expression of active MMP-2 and MMP-9 was increased in 9L/F344 rat brain during the growth of malignant gliomas at different time intervals, which indicate that 9L/F344 animal model may be a prospective animal model to test new MMPs inhibitors.

Using a New Alignment Kernel Function to Identify Secretory Proteins

As the knowledge of protein signal peptides can be used to reprogram cells in a desired way for gene therapy, signal peptides have become a crucial tool for researchers to design new drugs for targeting a particular organelle to correct a specific defect. To effectively use such a technique, however, we have to develop an automated method for fast and accurately predicting signal peptides and their cleavage sites, particularly in the post-genomic era when the number of protein sequences is being explosively increased. To realize this, the first important thing is to discriminate secretory proteins from non-secretory proteins. On the basis of the Needleman-Wunsch algorithm, we proposed a new alignment kernel function. The novel approach can be effectively used to extract the statistical properties of protein sequences for machine learning, leading to a higher prediction success rate.

Site-directed mutagenesis of gentisate 1,2-dioxygenases from Klebsiella pneumoniae M5a1 and Ralstonia sp. strain U2

Gentisate 1,2-dioxygenase (GDO, EC 1.13.11.4) is the first enzyme in gentisate pathway that catalyses the ring fission of gentisate to form maleylpyruvate. Phylogenetic tree of amino acid sequences from 11 GDOs demonstrates that the GDOs from different genus share identities between 12.1% and 64.8%. According to the alignment result, four highly conserved histidine residues in GDO from Klebsiella pneumoniae M5a1 and Ralstonia sp. strain U2 were chosen to be substituted with aspartate residues. Enzyme analysis indicated that substitution of any of these four histidine residues had resulted in the complete loss of its catalytic activity.

Recent progress in improving low-temperature stability of infrared thin-film interference filters

The degeneration of performance of an optical thin-film interference filter associated with the change of temperature is not acceptable. In this letter, we report a new progress in improving low-temperature performance of infrared narrow-band filters by using Pb(1-x)Ge(x)Te initial bulk alloy with appropriate Ge concentration x. It can be found that there exists a critical temperature for the investigated narrow-band filter, at which the temperature coefficient of filter is exactly zero. Therefore, by means of controlling the composition in (Pb(1-x)Ge(x))(1-y)Te(y) layers, the temperature coefficient of filter can be tunable at the designated low-temperature. In our present investigation, when temperature varies from 300 to 85 K, a shift of peak wavelength of 0.05935 nm.K-1 has been achieved.

Arg169 is essential for catalytic activity of 3-hydroxybenzoate 6-hydroxylase from Klebsiella pneumoniae M5a1

3-Hydroxybenzoate 6-hydroxylase from Klebsiella pneumoniae M5a1 is an enzyme that utilizes 3-hydroxybenzoate (3-HBA) as substrate yielding gentisate. Site-directed mutagenesis was carried out to define which residues may be involved in catalytic reaction. Substitution of arginine to glutamate at position 169 of the enzyme resulted in the complete loss of catalytic activity. This indicated Arg169 may play an important role in 3-HBA 6-hydroxylase catalysis.

Effects of the silanized mica surface on protein crystallization

A freshly cleaved mica surface silanized by 3-aminopropyl triethoxysilane is flat over a large area, displays a controlled degree of hydrophobicity and contains positive charges. In this paper, mica sheets silanized by this method have been used as crystallization surfaces for lysozyme, trichosanthin and three other proteins of unknown structure. Crystallization experiments have been carried out by the hanging-drop vapour-diffusion technique and the results indicate that the silanized mica surface can ameliorate the protein crystallization process considerably compared with a silanized glass cover slip control. For lysozyme on the silanized mica surface, the induction time required for crystal growth decreases markedly. For trichosanthin, the crystal size is obviously larger and the number of crystals grown is much lower. For the three proteins of unknown structure, the diffraction ability of the crystals is improved considerably.

Metabolism and disposition of gemfibrozil in Wistar and multidrug resistance-associated protein 2-deficient TR- rats

1. The roles of multidrug resistance-associated protein (Mrp) 2 deficiency and Mrp3 up-regulation were evaluated on the metabolism and disposition of gemfibrozil. 2. Results from in vitro studies in microsomes showed that the hepatic intrinsic clearance (CLint) for the oxidative metabolism of gemfibrozil was slightly higher (1.5-fold) in male TR- rats, which are deficient in Mrp2, than in wild-type Wistar rats, whereas CLint for glucuronidation was similar in both strains. 3. The biliary excretion of intravenously administered [14C]gemfibrozil was significantly impaired in TR-) rats compared with Wistar rats (22 versus 93% of the dose excreted as the acyl glucuronides over 72 h). Additionally, the extent of urinary excretion of radioactivity was much higher in TR- than in Wistar rats (78 versus 2.6% of the dose). 4. There were complex time-dependent changes in the total radioactivity levels and metabolite profiles in plasma, liver and kidney, some of which appeared to be related to the up-regulation of Mrp3. 5. Overall, it was demonstrated that alterations in the expression of the transporters Mrp2 and Mrp3 significantly affected the excretion as well as the secondary metabolism and distribution of [14C]gemfibrozil.

[Studies on the sensitivity of Plasmodium falciparum to pyronaridine/sulfadoxine/pyrimethamine in vitro]

OBJECTIVE

To develop an in vitro method for the assessment of drug response in P. falciparum to pyronaridine/sulfadoxine/pyrimethamine (PND/S/P).

METHODS

The PND/S/P microtest plate was designed, Rieckmann in vitro microtest(WHO standard kit) was used to test the sensitivity of P falciparum in continuous culture (FCC1/HN strain), and the data obtained were analyzed using a computer programme. Fractional inhibitory concentration (FIC) was calculated to test the possible synergy between PND and S/P.

RESULTS

The effect of the PND/S/P plates was fairly stable and the ED50 values of pyronaridine, sulfadoxine and pyrimethamine were 0.11, 215.12 and 2.9 pmol, respectively. The FIC obtained confirmed the synergism between PND and S/P.

CONCLUSION

The in vitro method can be used to assess the sensitivity of P. falciparum to pyronaridine/sulfadoxine/pyrimethamine.

Identification of novel metabolites of pioglitazone in rat and dog

1. Four new metabolites of pioglitazone were identified by liquid chromatography-mass spectrometry (LC-MS/MS) as being formed by hydroxylation (M-VII and M-VIII), opening of the thiazolidinedione ring (M-X) and by desaturation of the terminal ethyl side chain or tether ethoxy moiety (M-IX), respectively. The structure of one of the hydroxylated metabolites (M-VII) was confirmed by chemical modification using the Jones reaction. 2. Oxidative cleavage of the thiazolidinedione ring is a novel pathway not previously reported for pioglitazone. 3. The hydroxylated M-VII was detected in incubations with rat, dog and human liver and kidney microsomes, and in plasma from rats and dogs dosed orally with [(3)H]pioglitazone. 4. The carboxylic acid derivative of M-VII (M-V) and its taurine conjugate were the major radioactive components in dog bile.

Use of on-line hydrogen/deuterium exchange to facilitate metabolite identification

Biotransformation studies performed on an investigational compound (I, represented by R1-CH(NH(2))-CO-N(R2)-CH(2)-S-R3) led to the identification of five metabolites (M1-M5). Based on LC/MS (liquid chromatography/mass spectrometry) analysis which included the use of H(2)O and D(2)O in the mobile phases, they were identified as the sulfoxide (M1), sulfone (M2), carbamoyl glucuronide (M3), N-glucuronide (M4), and N-glucoside (M5) metabolites, respectively. The structure of M3, a less commonly seen carbamoyl glucuronide metabolite, was established using on-line H/D (hydrogen/deuterium) exchange experiments conducted by LC/MS. H/D exchange experiments were also used to distinguish the S-oxidation structures of M1 and M2 from hydroxylation. Herein, the application of deuterium oxide as the LC/MS mobile phase for structural elucidation of drug metabolites in biological matrices is demonstrated.

Parallel extraction columns and parallel analytical columns coupled with liquid chromatography/tandem mass spectrometry for on-line simultaneous quantification of a drug candidate and its six metabolites in dog plasma

A method with parallel extraction columns and parallel analytical columns (PEC-PAC) for on-line high-flow liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed and validated for simultaneous quantification of a drug candidate and its six metabolites in dog plasma. Two on-line extraction columns were used in parallel for sample extraction and two analytical columns were used in parallel for separation and analysis. The plasma samples, after addition of an internal standard solution, were directly injected onto the PEC-PAC system for purification and analysis. This method allowed the use of one of the extraction columns for analyte purification while the other was being equilibrated. Similarly, one of the analytical columns was employed to separate the analytes while the other was undergoing equilibration. Therefore, the time needed for re-conditioning both extraction and analytical columns was not added to the total analysis time, which resulted in a shorter run time and higher throughput. Moreover, the on-line column extraction LC/MS/MS method made it possible to extract and analyze all seven analytes simultaneously with good precision and accuracy despite their chemical class diversity that included primary, secondary and tertiary amines, an alcohol, an aldehyde and a carboxylic acid. The method was validated with the standard curve ranging from 5.00 to 5000 ng/mL. The intra- and inter-day precision was no more than 8% CV and the assay accuracy was between 95 and 107%.

[Preliminary study on apoptosis of BEL-7402 cells induced by Chinese herbs for warming yang and dispersing stasis]

OBJECTIVE

To investigate the antitumor mechanism of Chinese herbs for warming yang and dispersing stasis and observe the action of these herbs in inducing apoptosis of BEL-7402 cells.

METHOD

Apoptosis of BEL-7402 cells induced by the above-said herbs was detected through fast red tablet staining, flow cytometry and terminal uridine deoxynucleotidyl and labeling (TUNEL).

RESULT

After treating BEL-7402 cells with the herbs typical apoptosis characteristics could be seen under light microscope and TUNEL positive cells were detectable. The apoptotic rate was 13.9% (drug concentration 0.5%) and 21.6% (drug concentration 1%)

CONCLUSION

Chinese herbs for warming Yang and dispersing stasis could induce apoptosis of BEL-7402 cells and this effect depends on drug concentration. Inducing the apoptosis of tumor cells may be part of the mechanism displayed by Chinese herbs for warming Yang and dispersing stasis in treating hepatoma.

In vitro sensitivity of Plasmodium falciparum to eight antimalarials in China-Myanmar and China-Lao PDR border areas

In 1991-1995 by using the Rieckmann in vitro micro-method, susceptibilities of Plasmodium falciparum to eight antimalarials in the China-Lao PDR and China-Myanmar border areas were tested. The resistant rates of P. falciparum to chloroquinine were 95.0%-100%; IC50 114-240nmol/l. P. falciparum resistant rates to amodiaquine resistance accounted for 83.5%-100%, IC50 52-72nmol/l. All cases were sensitive to quinine, IC50 470-608nmol/l. P. falciparum isolates from the Lao PDR frontier were highly sensitive to artesunate, dihydroartemisinin, and arteether. Resistant rates from other areas were 0-11%. P. falciparum from China-Myanmar and Lao PDR border areas were also sensitive to mefloquine, IC50 68-88nmol/l. A longitudinal survey of the sensitivity of P. falciparum in vivo on the China-Lao PDR border showed that the average defervescent time of falciparum malaria was treated by pyronaridine increased from 32.7 +/- 16.0 hours during 1984-85 to 56.2 +/- 27.4 hours in 1995; the recrudescence rate rose up from 15.2% to 37.5%. The results monitored in vitro showed that all cases assessed in 1988 for response to pyronaridine were sensitive, but 36.4% of cases had emerging resistance, IC50 increased from 13nmol/l to 40 nmol/l. The above results suggested that P. falciparum in these areas has expressed resistance to chloroquine and amodiaquine. However, the parasites are still sensitive to artemisinin, pyronaridine, mefloquine, quinine, but with a declining sensitivities.

[Effects of high salt-loading on the regulation of angiotensin II receptor mRNA expression]

In the present study, the angiotensin II receptor subtype I-a (AT1a) and I-b (AT1b) mRNA levels in aortic smooth muscle (ASM), ventricular myocardium (VM) and adrenal from 12-week-old stroke-prone spontaneously hypertensive rats (SHRsp) and age-matched Wistar-Kyoto (WKY) rats with normal diet (control) and high salt-loading were examined by reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that: (1) The AT1a and AT1b mRNA levels in ASM and VM from SHRsp were lower than those from WKY rats (in ASM, 10% and 23%, while in VM, 23% and 40% lower, respectively). In contrast, both AT1a and AT1b mRNA levels in adrenal from SHRsp were higher (176% and 157%, respectively). (2) In the WKY rats with high salt-loading, the AT1a and AT1b mRNA levels in adrenal, as well as AT1b mRNA level in VM, increased significantly, as compared with the control (in adrenal, 167% and 401%, while in VM, 62%). However, the AT1a and AT1b mRNA levels in ASM, as well as AT1a mRNA level in VM, showed no obvious change. (3) In SHRsp with high salt-loading, the AT1b mRNA level in ASM, as well as AT1a and AT1b mRNA levels in VM, increased markedly (in ASM, 90%, while in VM, 590% and 200%); whereas the AT1a mRNA level in adrenal decreased significantly (58%). There was little influence on the regulation of AT1a (in ASM) and AT1b (in adrenal) receptor gene expression after high salt-loading. The results suggest that AT1a and AT1b receptors may be involved in the pathogenesis of salt-induced hypertension. The up-regulation of AT1b receptors in ASM may induce the remodeling of arterial wall, while that of AT1a and AT1b receptors in VM might contribute to ventricular hypertrophy in hypertension. Furthermore, there are certain differences between SHRsp and WKY rats with respect to the regulation of AT1a and AT1b receptor gene expression with or without external stimulation.

Changes in the resistance of Plasmodium falciparum to chloroquine in Hainan, China

In 1979, in view of the widespread resistance of Plasmodium falciparum to chloroquine in the island of Hainan, China, it use as an antimalarial was suspended throughout the island. A longitudinal survey of the chloroquine-sensitivity of P. falciparum was carried out over the period 1981-91 to investigate whether its resistance had changed from the 1979 level. In-vitro assays were carried out every 2-3 years, while in-vivo tests were performed annually over the period 1981-83 and also in 1991. Resistance to chloroquine declined progressively after its use had stopped. The in-vitro tests indicated that the rate of chloroquine-resistant P. falciparum was 97.9% in 1981, but dropped to 60.9% in 1991 (P < 0.001). The mean concentration of chloroquine for complete inhibition of schizont formation was 10.4 pmol/microliters in 1981, but decreased to 3.0 pmol/microliters in 1991 (P < 0.001). The proportion of samples taken from malaria cases that required high concentrations ( > 6.4 pmol/microliters) of chloroquine for complete inhibition of schizont formation was 83.3% in 1981, but only 17.4% in 1991 (P < 0.001); at low concentrations ( > 1.6 pmol/microliters), the corresponding proportions increased from 4.2% in 1981 to 60.8% in 1991 (P < 0.001). In the 4-week in-vivo test, the rate of chloroquine-resistant P. falciparum decreased from 84.2% in 1981 to 40% in 1991 (P < 0.001). RII + RIII cases represented 59.4% of the total resistant cases in 1981, but decreased to 37.5% in 1991 (0.02 > P > 0.01).

[Effects of furyl-dihydropyridine I on coronary collateral circulation in myocardial infarction of dogs]

Effects of furyl-dihydropyridine I (FDP-1) on collateral circulation were observed in ischemic myocardium of dogs. FDP-1 (200 micrograms.kg-1) of intracoronary injection increased collateral flow, reduced systemic artery resistance, and coronary systolic pressure in infarcted region and the area of infarction decreased from 28.9 +/- 1.3% to 15.3 +/- 1.2% (P < 0.01, n = 6). The results indicated that FDP-1 could improve coronary collateral circulation, increase collateral flow in ischemic region, decrease collateral flow in ischemic region, decrease myocardial oxygen demand, and protect myocardial ischemia.

[Unusual manifestation of cerebral cysticercosis]

We have surgically treated two patients with cerebral cysticercosis, which were pre-operatively unexpected due to unusual CT and MRI manifestations. A 24 year old chinese farmer with intermittent severe headache for 6 years was examined by CT and MRI. A huge cystic lesion with same density or intensities to CSF occupied retroclival posterior fossa to upper cervical spinal canal and displaced neural structures backwardly. By suboccipital craniectomy, watery clear cyst fluid of 44ml was aspirated and the shrunken cyst was pulled out with ease. It was unable to predict until an electron microscopic study, which revealed a larva with three layers of microvilli, vesicular tegmentum and infrategmental muscle bundles and vesicles. The findings were same to those of racemose cysticercus of human brain. Giant cysts of cysticercosis were infrequently present supratentorially, although infratentorial or basal cysticercosis were racemose and small. The present case may be the first case of a huge cyst of cysticercosis in posterior fossa. A 44 year old Japanese businessman with 15 years history of general convulsion underwent craniotomy due to a small, but growing cystic granulomatous mass in right inferior frontal gyrus. The CT scan examined at 3 years after his first general convulsion revealed a small round low density mass, 5mm in diameter, in right frontal lobe and its wall was weakly enhanced by contrast media. The follow-up CT scans and MRIs revealed that the enhancing cystic mass became thick and deformed, and perifocal edema came to evident and progressed stepwise by attacks of general convulsions.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effects of 3,6-dimethylamino-dibenzopyriodonium edetate on global ischemia reperfused isolated rat hearts

The effects of 3,6-dimethylamino-dibenzopyriodonium edetate (IHC-72) on global ischemia reperfused rat hearts were investigated. In the isolated working rat heart, 40-min global ischemia followed by 30-min reperfusion resulted in increases of ventricular tachycardia (VT) and ventricular fibrillation (VF), increases of creatine kinase (CK) release and malondialdehyde (MDA) contents, but decreased superoxide dismutase (SOD) activity. Following ischemia and reperfusion, the accumulation of myocardial calcium increased. IHC-72 50 mumol.L-1 given 10 min before ischemia and during reperfusion decreased the cardiac CK release, VT, and VF, reduced the MDA contents, prevented the reduction of SOD activity and attenuated the accumulation of myocardial calcium and sodium vs control. These results indicated that IHC-72 protected myocardial reperfused injury.

[Effects of furyl-dihydropyridine on action potential ventricular myocardium of rabbit in vivo and isolated guinea pig left atrium in vitro]

Effects of furyl-dihydropyridine (FDP) on action potential of rabbit ventricular myocardium in vivo were observed with floating microelectrode technique. FDP 0.5 mg.kg-1 i.v. increased APD30 from 104 +/- 7 to 127 +/- 7 ms, APD90 from 146 +/- 10 to 177 +/- 9 ms (P < 0.01, n = 7), decreased the heart rate from 230 +/- 18 to 203 +/- 20 bpm (P < 0.05). Nifedipine (Nif) 0.5 mg.kg-1 i.v. reduced APD and increased the HR in rabbit. In guinea pig left atrium, FDP and Nif decreased the APD, the effects of acetylcholine to shorten the APD was antagonized by FDP 1 mumol.L-1. In rabbit's sinoatrial nodes, FDP 0.5, 1 mumol.L-1 also suppressed the APA and increased the spontaneous sinus cycle length (SCL) and APD50. These results indicate that FDP may inhibit the Ca2+ and K+ currents of myocardium.