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1.
Clin Radiol ; 74(9): 735.e15-735.e22, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31256908

ABSTRACT

AIM: To investigate the effect of peri-ampullary duodenal diverticula (PAD) on extrahepatic bile duct (EHBD) dilatation before and after cholecystectomy. MATERIALS AND METHODS: During a 5-year period, a total of 860 consecutive patients with prior cholecystectomy were examined using abdominal computed tomography (CT). After exclusion of those with other obstructive EHBD lesions, 61 patients with PAD were recruited for evaluation of EHBD dilatation before and after cholecystectomy and were compared with a randomly sampled control group (n=113) without PAD. EHBD diameter was measured on coronal reconstruction CT using electronic callipers on the picture archiving and communication system monitors by two reviewers in consensus. RESULTS: There was no significant difference in EHBD diameter between PAD and non-PAD groups (8.2±2.8 versus 7.8±2.3 mm; p=0.276) before cholecystectomy. Compared with preoperative diameter, EHBD was significantly dilated after cholecystectomy (7.9±2.5 versus 9.8±3.4 mm, p<0.001), regardless of the presence of PAD; the degree of change was more prominent in the PAD group than in the non-PAD group (3.3±2.4 versus 1.1±1.6 mm; p<0.001) after surgery. The size of PAD did not affect the degree of EHBD dilatation after cholecystectomy (p=0.522). In the non-PAD group, the degree of EHBD dilatation was positively correlated with the follow-up interval after cholecystectomy (r=0.298; p=0.002), while the PAD group showed no significant correlation (r=-0.036; p=0.797). In patients with ≥2 mm postoperative EHBD dilatation, PAD incidence was higher than that in other patients (odds ratio, 8.739; p<0.001). CONCLUSION: Regardless of their size or postoperative follow-up duration, PAD induce marked post-cholecystectomy biliary dilatation.


Subject(s)
Bile Ducts/pathology , Cholecystectomy , Diverticulum/complications , Diverticulum/diagnostic imaging , Duodenal Diseases/complications , Duodenal Diseases/diagnostic imaging , Tomography, X-Ray Computed , Adolescent , Adult , Aged , Aged, 80 and over , Bile Ducts/diagnostic imaging , Dilatation, Pathologic/diagnostic imaging , Female , Humans , Male , Middle Aged , Postoperative Complications/diagnostic imaging
2.
Eur J Neurol ; 23(5): 948-57, 2016 May.
Article in English | MEDLINE | ID: mdl-26917248

ABSTRACT

BACKGROUND AND PURPOSE: The association of serum uric acid, cerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) and longitudinal cognitive decline was evaluated using the AD Neuroimaging Initiative database. METHODS: In 271 healthy subjects, 596 mild cognitive impairment patients and 197 AD patients, serum uric acid and CSF AD biomarkers were measured at baseline, and Mini-Mental State Examination and AD Assessment Scale - Cognitive Subscale (ADAS-cog) were assessed serially (mean duration, 2.9 years). The effect of uric acid on longitudinal cognitive decline was evaluated using linear mixed effect models for Mini-Mental State Examination and ADAS-cog scores in female and male subjects separately, with possible confounders controlled (model 1). To determine the effects of uric acid independent of CSF biomarker (Aß1-42 or tau) and to test whether the detrimental effects of CSF biomarker differ according to uric acid, CSF biomarker and its interaction with uric acid were further included in model 1 (model 2). RESULTS: Higher levels of uric acid were associated with slower cognitive decline, particularly in the mild cognitive impairment and dementia subgroups, and more prominently in female subjects. Model 2 with CSF Aß1-42 showed that higher levels of uric acid were associated with a slower cognitive decline and alleviated the detrimental effect of Aß1-42 on cognitive decline. Model 2 with CSF tau showed that higher levels of uric acid alleviated the detrimental effect of tau on cognitive decline in female subjects but not in male subjects. CONCLUSION: Higher levels of uric acid had protective effects on longitudinal cognitive decline independent of and interactively with CSF AD biomarkers.


Subject(s)
Alzheimer Disease/diagnosis , Cognition Disorders/diagnosis , Cognitive Dysfunction/diagnosis , Uric Acid/blood , Aged , Aged, 80 and over , Alzheimer Disease/blood , Alzheimer Disease/cerebrospinal fluid , Alzheimer Disease/complications , Biomarkers/blood , Biomarkers/cerebrospinal fluid , Cognition Disorders/blood , Cognition Disorders/cerebrospinal fluid , Cognition Disorders/etiology , Cognitive Dysfunction/blood , Cognitive Dysfunction/cerebrospinal fluid , Cognitive Dysfunction/etiology , Databases, Factual , Female , Humans , Male , Middle Aged , Neuropsychological Tests
3.
Eur J Neurol ; 21(6): 922-e50, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24661277

ABSTRACT

BACKGROUND AND PURPOSE: To evaluate whether white matter hyperintensities (WMHs) may act as an independent predictor for progression of cognitive status, the authors analyzed the longitudinal effects of WMHs on cognitive dysfunction in non-demented patients with Parkinson's disease (PD). METHODS: A total of 111 patients with PD were enrolled, including subjects with mild cognitive impairment (MCI, n = 65) and cognitively normal subjects (CN, n = 46). These individuals were classified as MCI converters (n = 22) or MCI non-converters (n = 43) and CN converters (n = 18) or CN non-converters (n = 28) based on whether they were subsequently diagnosed with PD dementia or PD-MCI during a minimum 24-month follow-up. The WMH burden and the Cholinergic Pathway Hyperintensities Scale (CHIPS) and their relationships to longitudinal changes in cognitive performance were examined. RESULTS: PD-MCI converters had larger WMH volume (14421.0 vs. 5180.4, P < 0.001) and higher CHIPS score (22.6 vs. 11.2, P = 0.001) compared with PD-MCI non-converters. Logistic regression analysis revealed in patients with PD-MCI that WMH volume (odds ratio 1.616, P = 0.009) and CHIPS score (odds ratio 1.084, P = 0.007) were independently associated with PD dementia conversion. However, WMH volume and CHIPS score did not differ between PD-CN converters and PD-CN non-converters. In patients with PD-MCI, both WMH volume and CHIPS score were closely associated with longitudinal decline in general cognition, semantic fluency and Stroop test scores. CONCLUSIONS: The present study demonstrates that WMH burden is a significant predictor of conversion from PD-MCI to PD dementia and is related to ongoing decline in frontal-lobe-based cognitive performance.


Subject(s)
Cognitive Dysfunction/pathology , Parkinson Disease/pathology , White Matter/pathology , Aged , Aged, 80 and over , Cognition , Cognitive Dysfunction/complications , Disease Progression , Female , Humans , Longitudinal Studies , Magnetic Resonance Imaging , Male , Middle Aged , Neuropsychological Tests , Parkinson Disease/complications
4.
Plant Dis ; 96(8): 1123-1134, 2012 Aug.
Article in English | MEDLINE | ID: mdl-30727050

ABSTRACT

Xylella fastidiosa causes disease in a number of economically important crops, ornamental plants, and shade trees, including grapevine, citrus, oleander, and sycamore. In pecan, X. fastidiosa causes pecan bacterial leaf scorch (PBLS), which leads to defoliation and reduces nut yield. No economically effective treatments are available for PBLS. In order to improve PBLS management practices, it is necessary to determine the subspecies of X. fastidiosa strains that infect pecan so that potential sources of inoculum may be identified. Multiprimer polymerase chain reaction (PCR) and phylogenetic analyses using nucleotide sequence data from the 16S-23S rRNA intergenic transcribed spacer (ITS) region and pglA consistently identified strains of X. fastidiosa isolated from pecan as X. fastidiosa subsp. multiplex. Enterobacterial repetitive intergenic consensus PCR and repetitive extragenic palindromic (REP)-PCR analyses were congruent with phylogenetic analyses. REP-PCR analyses indicated genetic variation within strains of X. fastidiosa from pecan. From these same analyses, X. fastidiosa strains from sycamore, grapevine, and oleander from Louisiana were identified as subsp. multiplex, subsp. fastidiosa, and subsp. sandyi, respectively. This study provides additional information about the host ranges of X. fastidiosa subspecies.

5.
Water Sci Technol ; 56(8): 31-9, 2007.
Article in English | MEDLINE | ID: mdl-17978430

ABSTRACT

Uncertainty in water quality model predictions is inevitably high due to natural stochasticity, model uncertainty, and parameter uncertainty. An integrated modelling system (modified-BASINS) under uncertainty is described and demonstrated for use in receiving-water quality prediction and watershed management. A Monte Carlo simulation was used to investigate the effect of various uncertainty types on output prediction. Without pollution control measures in the watershed, the concentrations of total nitrogen (T-N) and total phosphorus (T-P) in the Hwaong Reservoir, considering three uncertainty types, would be less than about 4.4 and 0.23 mg L(-1), respectively, in 2012, with 90% confidence. The effects of two watershed management practices, wastewater treatment plants (WWTP) and constructed wetlands (WETLAND), were evaluated. The combined scenario (WWTP + WETLAND) was the most effective at improving reservoir water quality, bringing concentrations of T-N and T-P in the Hwaong Reservoir to less than 3.4 and 0.14 mg L(-1), 24 and 41% improvements, respectively, with 90% confidence. Overall, the Monte Carlo simulation in the integrated modelling system was practical for estimating uncertainty and reliable in water quality prediction. The approach described here may allow decisions to be made based on the probability and level of risk, and its application is recommended.


Subject(s)
Models, Theoretical , Uncertainty , Water Pollution/prevention & control , Water Supply , Geography , Korea , Monte Carlo Method , Water Movements
6.
Water Sci Technol ; 55(1-2): 503-11, 2007.
Article in English | MEDLINE | ID: mdl-17305176

ABSTRACT

The performance of a constructed wetland (CW) and wastewater stabilisation pond (WSP) system for sewage reclamation and paddy rice irrigation in a decentralised rural area was examined using a feasibility study. The CW was satisfactory for sewage treatment, with good removal efficiency even in the winter period, but the effluent concentration was relatively high in the winter period owing to the high influent concentration. The CW effluent was further treated in a WSP and the WSP effluent was considered safe for crop irrigation with respect to sewage-borne pathogens. Reclaimed water irrigation did not adversely affect the yield of rice; on the contrary, it resulted in an approximately 50% greater yield than in controls. The chemical characteristics of the soil did not change significantly during the experimental period of irrigation with reclaimed water. In the winter, CW effluent could be stored and treated in a WSP until the spring; the water could then be discharged or reused for supplemental irrigation during the typical Korean spring drought. Overall, sewage treatment and agronomic reuse using a CW-WSP system could be a practical integrated sewage management measure for protecting receiving water bodies and overcoming water shortages in decentralised rural areas.


Subject(s)
Agriculture , Sewage , Waste Disposal, Fluid/methods , Wetlands , Conservation of Natural Resources , Ecosystem , Rural Population , Soil
7.
Water Sci Technol ; 53(1): 25-32, 2006.
Article in English | MEDLINE | ID: mdl-16532732

ABSTRACT

Applicability of a widely accepted watershed-based water quality assessment tool (BASINS) and its associated watershed model (WinHSPF) was evaluated on the Seamangeum watershed in Korea. The study site is the largest polder project area in Korea and its environmental quality has been debated for the last five years. BASINS was found to be a convenient and powerful tool for assessment of watershed characteristics, and provided various tools to delineate the watershed into land segments and river reaches, reclassify land use, and parameterize for WinHSPF simulation. Calibration results were satisfactory showing model efficiency over 0.80 for stream flow, temperature, and dissolved oxygen simulation, and model output for water quality constituents also reasonably matched the observed data. It was demonstrated that calibration with dry-day data for a relatively long period might be adequate to simulate hydrologic characteristics and water quality of the watershed with WinHSPF, and using parameters generated with BASINS for nonpoint source pollution simulation is suggested when enough wet-day monitoring data are not available. The unit-area load of biochemical oxygen demand, total nitrogen, and total phosphorus was 27.8, 48.2, and 4.3 kg/ha/yr, respectively. These values are within the expected range but on the high side of the reported values, which implies that effective control measures are required to protect water quality of the downstream reservoir. Overall, BASINS/WinHSPF was applicable and found to be a powerful tool in pollutant loading estimation from the watershed, and its use in Korea is recommended.


Subject(s)
Models, Theoretical , Water Pollutants/analysis , Water Supply , Calibration , Environmental Monitoring , Korea , Oxygen/analysis , Oxygen/chemistry , Water/chemistry
8.
Water Sci Technol ; 51(3-4): 99-105, 2005.
Article in English | MEDLINE | ID: mdl-15850179

ABSTRACT

Mass balance analysis and water quality model development for paddy field were performed using field experimental data during 2001-2002. About half (47-62%) of the total outflow was lost by surface drainage, with the remainder (490-530 mm) occurring by evapotranspiration. Most of nutrient inflow and outflow were mediated by fertilization and plant uptake, respectively. Nutrient outflow by surface drainage runoff was substantial about 15%-29% for T-N and 6%-13% for T-P. However, the responses of yield and drainage outflow to fertilization were not significant in this study. A water quality model applicable to paddy fields was developed and it demonstrates good agreement with observed data. The nutrient concentration of ponded water was high by fertilization at early culture periods, so reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Shallow irrigation, raising the weir height in diked rice fields, and minimizing forced surface drainage are suggested to reduce surface drainage outflow.


Subject(s)
Models, Theoretical , Nitrogen/analysis , Phosphorus/analysis , Water Pollutants, Chemical/analysis , Fertilizers , Korea , Oryza , Reproducibility of Results , Water Movements
9.
Contact Dermatitis ; 45(4): 214-6, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11683831

ABSTRACT

Gold sodium thiosulfate (GSTS) is reputed to be the most reliable gold antigen, but control studies are still required. Although Koreans have more varied sources of contact with gold, such as herbal medicines with gold coatings and indwelling gold acupuncture needles, no epidemiological studies have been performed. This study examined the frequency and sources of contact allergy to gold in South Korea by a multicenter study. Patch testing with 0.5% GSTS in pet. was conducted in 255 eczema patients and 58 control subjects. Results were observed at 21 days (D) to ensure there were no undetected late reactions in 54 observed patients and 47 controls. 8 (3.1%) of the 255 patients reacted positively to GSTS, including 1 with a late reaction. 1 of the 58 controls showed a positive reaction to GSTS on D4 with a negative reaction on D14. Clinical relevance was lacking in the patients with positive reactions. Unexpectedly, the above particular sources of gold contact gave rise to few allergic reactions in our patients.


Subject(s)
Dermatitis, Allergic Contact/epidemiology , Gold Sodium Thiosulfate , Gold/adverse effects , Adolescent , Adult , Aged , Chi-Square Distribution , Child , Female , Humans , Hypersensitivity, Delayed/epidemiology , Korea/epidemiology , Male , Middle Aged , Patch Tests , Surveys and Questionnaires
10.
Article in English | MEDLINE | ID: mdl-11501308

ABSTRACT

A pilot study was performed to examine the feasibility of using a constructed wetland system for treatment of sewage in a Korean rural community. The treatment system was a subsurface flow wetland with a loading rate and hydraulic residence time of 6.3 cm/day and 3.5 days, respectively. The wetland system was highly effective in treating the sewage; median removal efficiencies of BOD5 (biological oxygen demand) and TSS (total suspended solids) were about 70.0%, with median effluent concentrations of 24 and 13 mg/L, respectively, for these constituents. However, BOD5 and TSS did often exceed the effluent water quality standards of 20 mg/L. Removal of TN (total nitrogen) and TP (total phosphorus) was relatively less effective and median effluent concentrations were approximately 81 and 8 mg/L, respectively. The treatment system did not experience any clogging or accumulation of organic and inorganic solids during the study, and during winter a substantial amount of removal of BOD5 and TSS continued to occur. Overall, the constructed wetland was judged to be an effective sewage treatment system, but not sufficient by itself to attain regional water quality standards. Therefore, treatment of rural sewage by a wetland system should be followed by another process such as use of the effluent for irrigation of agricultural crops (e.g., rice).


Subject(s)
Ecosystem , Nitrogen/metabolism , Phosphorus/metabolism , Sewage , Water Pollution/prevention & control , Agriculture , Biomass , Feasibility Studies , Oxygen/metabolism , Plants , Water Movements
11.
Neurol Res ; 23(8): 881-6, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11760882

ABSTRACT

Monitoring the descending neural motor volleys (MEPs), in comparison to muscle action potentials, allows sensitive motor assessment under anesthesia irrespective of the use of muscular blockade and status of skeletal musculature. Ketamine hydrochloride (KH) had preserved muscle MEPs on a pre-established primate model. The present work examines the effect of incremental hypnotic KH dosages thoracic neural on somatosensory (SEP) and MEPs recorded epidurally in response to transcranial magnetic stimulation (TMS). Through a small thoracic T11-T12 laminotomy, an insulated double bipolar electrode was inserted epidurally and cephalad in seven cynomolgus monkeys. Thoracic spinal TMS-MEPs, and SEPs, were tested against graded increase of KH doses (0.01, 0.018, 0.032, 0.056, 0.1, and 0.18 mg kg(-1) min(-1) i.v. infusion). The direct (D-) and indirect (I-) epidural MEP peaks were well-defined under sole KH infusion. The waveforms were consistent at various dosages. At the highest cumulative dose (0.18 mg kg(-1) min(-1), total 6.5 mg kg(-1) over 150 min), I5 was host and I3 and I4 latencies were delayed. The scalp and spinal SEP showed no significant change. Recording of both neural D- and I- MEPs and SEPs is feasible under high sole i.v. KH. It is the first agent to maintain up to four later I1 peaks. The reproducibility of both modalities is unquestionable under KH-based deep anesthesia. This reflects the maintenance of state of neural excitability under KH.


Subject(s)
Anesthetics, Dissociative/pharmacology , Evoked Potentials, Motor/drug effects , Evoked Potentials, Somatosensory/drug effects , Ketamine/pharmacology , Animals , Dose-Response Relationship, Drug , Electric Stimulation , Evoked Potentials, Motor/physiology , Evoked Potentials, Somatosensory/physiology , Macaca fascicularis , Magnetics
12.
Biol Pharm Bull ; 23(10): 1247-9, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11041261

ABSTRACT

From the butanol fraction of the starfish Asterina pectinifera Müler et Troschel (Asteriidae), we have isolated a new component, 5alpha-cholest-7-en-3beta-ol. Its antigenotoxic and antimutagenic activities were examined by the SOS chromotest with Escherichia coli PQ37 and by Ames test with Salmonella typhimurium TA1538, respectively. 5alpha-Cholest-7-en-3beta-ol showed potent antigenotoxic activity against the mutagens, both MNNG and NQO. For 100% of antigenotoxicity, the concentration of the compound applied against MNNG and NQO were 10 microg and 5 microg per reaction tube, respectively. Its antimutagenic activity with S. typhimurium TA1538 against the mutagen MNNG was very effective. When its concentrations were varied from 1 up to 10 microg dose per plate, the inhibition ratio of revertant CFU of TA1538 per plate was increased accordingly, from 25.2 to 99.2%. These results suggest that 5alpha-cholest-7-en-3beta-ol possesses antigenotoxic and antimutagenic activity and might be useful as a chemopreventive agent.


Subject(s)
Antimutagenic Agents/pharmacology , Cholesterol/pharmacology , Starfish/chemistry , 4-Nitroquinoline-1-oxide/toxicity , Animals , Escherichia coli/drug effects , Escherichia coli/genetics , Methylnitronitrosoguanidine/toxicity , Quinolones/toxicity , Salmonella typhimurium/drug effects , Salmonella typhimurium/genetics , Tissue Extracts/pharmacology
13.
Neurol Res ; 21(8): 714-20, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10596378

ABSTRACT

There is growing interest and need to monitor reliably both motor (MEP) and somatosensory (SEP) evoked potentials under anesthesia. On a pre-established primate model, the present study examined the effect of incremental etomidate (ET) dosages on spinal neural MEPs to transcranial magnetic stimulation (TMS) and posterior tibial rate (PTN) SEPs. Through a small thoracic T11-T12 laminotomy, an insulated double bipolar electrode was inserted epidurally in seven cynomolgus monkeys. Spinal TMS-MEPs, PTN-SEPs, and frontal EEG were tested against graded increase of ET doses. Etomidate 0.5 mg kg-1 i.v. was initially given and followed by 30 min continuous infusion of 0.01 mg kg-1 min-1, 0.018, 0.032, 0.056, 0.1, and 0.18 mg kg-1 min-1 in that order. Measurable spinal MEPs and SEPs were recorded under deep ET anesthesia (total 12.38 mg kg-1 cumulative dose over 180 min). The EEG showed marked slow wave and graded burst suppression at cumulative dose of > or = 3.14 mg kg-1. The direct (D) and subsequent initial indirect (I) waves (I1, I2, I3) were reproducible at doses < 0.18 mg kg-1 min-1 infusion. The latter I-waves (I4 and I5) showed graded loss at infusion dosage 0.056 mg kg-1 min-1. Etomidate remains an anesthetic of attractive features in neuroanesthesia. In the primate model, neural MEPs-SEPs were reproducible despite the exceedingly high dose of ET and markedly depressed EEG. Moreover, MEP-SEP can be monitored during ET burst-suppressive neuroprotective state. The study may set a model in humans for intra-operative multi-modality neurophysiologic recording under ET-based anesthesia.


Subject(s)
Etomidate/pharmacology , Evoked Potentials, Motor/drug effects , Evoked Potentials, Somatosensory/drug effects , Hypnotics and Sedatives/pharmacology , Spinal Cord/physiology , Animals , Dose-Response Relationship, Drug , Electric Stimulation , Electroencephalography , Macaca , Magnetics , Motor Cortex/physiology , Somatosensory Cortex/physiology , Tibial Nerve/physiology
14.
Neurol Res ; 21(4): 359-67, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10406007

ABSTRACT

Monitoring Motor Evoked Potential (MEP) to Transcranial Stimulation (TMS) monitoring (MEP) is a growing technique to assess motor function under anesthesia. The following primate study was conducted to analyze the non-myogenic spinal motor and sensory volleys and to examine their reproducibility under nitrous oxide-methohexidone anesthesia. The traveling periodic spinal descending MEP to TMS and ascending somatosensory (SEP) to posterior tibial nerve stimulation across the thoracic cord were recorded in 12 cynomolgus monkeys. Through a small T11-T12 laminotomy, an insulated stainless steel electrode was inserted into the epidural thoracic space. The potentials were analyzed under 50 vol% NO in O2 with methohexital (0.1-0.2 mg kg-1 min-1). A well-defined periodic TMS-MEPs and PTN-SEPs were recorded with high reproducibility and consistency in repeated trials under N2O-methohexital anesthesia. MEP tracing consisted of an initial peak (direct (D) wave), occurring at 2.43 (+/- 0.28) msec followed by subsequent five positive (indirect (I) waves). Spinal SEPs-MEPs were clearly defined, morphologically stable, and consistent over time under N2O-methohexitone anesthesia. The present primate study may set a model to monitor both modalities in anesthetized neurosurgical patients.


Subject(s)
Evoked Potentials, Motor/physiology , Evoked Potentials, Somatosensory/physiology , Spinal Cord/physiology , Anesthesia, General/methods , Animals , Electric Stimulation/methods , Electrodes, Implanted , Electromagnetic Phenomena/methods , Macaca , Respiration, Artificial/methods , Tibial Nerve/physiology
15.
Proc Natl Acad Sci U S A ; 95(17): 10206-11, 1998 Aug 18.
Article in English | MEDLINE | ID: mdl-9707625

ABSTRACT

The Hrp (type III protein secretion) system is essential for the plant parasitic ability of Pseudomonas syringae and most Gram-negative bacterial plant pathogens. AvrB and AvrPto are two P. syringae proteins that have biological activity when produced via heterologous gene expression inside plant cells or when produced by Hrp+ bacteria. Avr-like proteins, presumably injected by the Hrp system on bacterial contact with plant cells, appear to underlie pathogenic interactions, but none has been observed outside of the bacterial cytoplasm, and identifying novel genes encoding them is tedious and uncertain without a phenotype in culture. Here we describe a cloned Hrp secretion system that functions heterologously in Escherichia coli to secrete AvrB and AvrPto in culture and to promote AvrB and AvrPto biological activity in inoculated plants. The hrp gene cluster, carried on cosmid pCPP2156, was cloned from Erwinia chrysanthemi, a pathogen that differs from P. syringae in being host promiscuous. E. coli DH5alpha carrying pCPP2156, but not related Hrp-deficient cosmids, elicited a hypersensitive response in Nicotiana clevelandii only when also expressing avrB in trans. The use of pAVRB-FLAG2 and pAVRPTO-FLAG, which produce Avr proteins with a C-terminal FLAG-epitope fusion, enabled immunoblot detection of the secretion of these proteins to E. coli(pCPP2156) culture media. Secretion was Hrp dependent, occurred without leakage of a cytoplasmic marker, and did not occur with E. coli(pHIR11), which encodes a functional P. syringae Hrp system. E. coli(pCPP2156) will promote investigation of Avr protein secretion and systematic prospecting for the effector proteins underlying bacterial plant pathogenicity.


Subject(s)
Bacterial Proteins/physiology , Dickeya chrysanthemi/genetics , Dickeya chrysanthemi/physiology , Escherichia coli/genetics , Escherichia coli/physiology , Pseudomonas/pathogenicity , Base Sequence , Cosmids , DNA Primers/genetics , Genes, Bacterial , Multigene Family , Pseudomonas/physiology , Signal Transduction , Virulence
16.
Mol Plant Microbe Interact ; 11(6): 563-7, 1998 Jun.
Article in English | MEDLINE | ID: mdl-9612954

ABSTRACT

The hrpC operon of Erwinia chrysanthemi EC16 encodes five genes conserved in Erwinia amylovora and Pseudomonas syringae. Mutagenesis indicated that hrcC is required for elicitation of the hypersensitive reaction in tobacco leaves. The unexpected presence of plcA and homologs of hemolysin/activator genes in the regions flanking the hrcC and hrpN operons is reported.


Subject(s)
Bacterial Outer Membrane Proteins/genetics , Bacterial Proteins , Dickeya chrysanthemi/genetics , Genes, Bacterial , Operon , Type C Phospholipases/genetics , Adhesins, Bacterial/genetics , Amino Acid Sequence , Base Sequence , Carrier Proteins/chemistry , Carrier Proteins/genetics , DNA Primers , Hemolysin Proteins/chemistry , Hemolysin Proteins/genetics , Molecular Sequence Data , Sequence Homology, Amino Acid
17.
J Bacteriol ; 177(15): 4553-6, 1995 Aug.
Article in English | MEDLINE | ID: mdl-7635842

ABSTRACT

Erwinia chrysanthemi mutant CUCPB5047, delta(pelA pelE) delta(pelB pelC)::28bp delta(pelX) delta 4bp pehX::omega Cmr, was constructed, mutated with Tn5tac1, and screened for isopropyl-beta-D-thiogalactopyranoside-dependent pectate lyase (Pel) production. A Kmr SacI fragment from the hyperexpressing Pel+ mutant CUCPB5066 was cloned into Escherichia coli and sequenced. The gene identified, pelL, encodes a novel, asparagine-rich, highly alkaline enzyme that is similar in primary structure to PelX and in enzymological properties to PelE.


Subject(s)
Dickeya chrysanthemi/genetics , Isoenzymes/genetics , Mutation , Polysaccharide-Lyases/genetics , Amino Acid Sequence , Base Sequence , Cloning, Molecular , Dickeya chrysanthemi/enzymology , Gene Deletion , Genes, Bacterial , Molecular Sequence Data , Plasmids , Polysaccharide-Lyases/biosynthesis
18.
Cancer Res ; 46(11): 5571-5, 1986 Nov.
Article in English | MEDLINE | ID: mdl-3019529

ABSTRACT

Superoxide dismutase mimetic copper(II) complexes, such as copper(II)(3,5-diisopropylsalicylate)2 (CuDIPS), inhibit phorbol ester stimulated tumor promotion in mouse skin. Therefore, CuDIPS was tested as a potential inhibitor of another effect of phorbol esters, induction of interleukin 2 (IL2) synthesis, in the mouse thymoma cell line EL4. CuDIPS inhibited phorbol ester induced IL2 production in a concentration dependent manner with a 50% inhibitory concentration of about 10 microM. However, the ligand 3,5-diisopropylsalicylic acid also inhibited the induction of IL2 by phorbol esters (50% inhibitory concentration, 15 microM). Since the superoxide dismutase mimetic activity of CuDIPS is not stable in the presence of ethylenediaminetetraacetic acid, the effects of CuDIPS could be due to the free ligand and not to the intact metallocomplex. Consequently, a series of extremely stable copper(II) macrocyclic compounds was synthesized, and the reduction potential, superoxide dismutase mimetic activity, and ability to inhibit phorbol ester induced IL2 production were determined for each. Of the copper(II) macrocyclic complexes studied, only the most potent superoxide dismutase mimetic compound was found to inhibit phorbol ester induced IL2 production. Copper(II) complexes had to be added no later than 4 following phorbol ester administration to be effective inhibitors of the IL response, suggesting that these compounds act subsequent to the binding of phorbol esters but prior to the transcription of IL2 messenger RNA. Adherence of EL4 cells to substrate in response to phorbol esters was unaffected by copper(II) compounds. In summary, copper(II) compounds with appropriate reduction potentials can act within a defined time period to inhibit some, but not all, of the effects of phorbol esters on EL4 cells.


Subject(s)
Copper/pharmacology , Interleukin-2/biosynthesis , Phorbol Esters/antagonists & inhibitors , Salicylates/pharmacology , Superoxides/physiology , Animals , Cations, Divalent , Cell Adhesion/drug effects , Mice , Protein Biosynthesis , Solubility , Superoxide Dismutase/metabolism , Time Factors
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