Presence of the LEE (locus of enterocyte effacement) in pig attaching and effacing Escherichia coli and characterization of eae, espA, espB and espD genes of PEPEC (pig EPEC) strain 1390

In the present study, attaching and effacing Escherichia coli (AEEC) O45 isolates from post-weaning pigs with diarrhoea were examined for the presence of the LEE (locus of enterocyte effacement) using various DNA probes derived from the LEE of human enteropathogenic E. coli (EPEC) strain E2348/69. The LEE fragment was conserved among the eae -positive pig isolates. The attaching and effacing activity of PEPEC (pig EPEC) O45 isolates is highly correlated with the presence of the LEE. Nevertheless, for some PEPEC isolates, the insertion site of the LEE is different or has diverged during evolution. The presence of the LEE fragment in PEPEC isolates provides further evidence that the LEE region is conserved among AEEC of different animal origins. In addition, the nucleotide sequence of the region containing the eae gene and esp genes of a pig AEEC isolate, strain 1390, was determined. Among examined Eae proteins, Eae of strain 1390 showed the highest similarity with Eae belonging to the beta intimin group such as the Eae of rabbit AEEC. Moreover, all pig strains that produced attaching and effacing lesions in piglets and pig ileal explants belonged to the beta intimin group. The deduced amino acid sequences of the EspA, EspB and EspD proteins of strain 1390 showed particularly strong homology to those of AEEC strains presenting a beta intimin allele. Thus, pig AEEC possess the LEE sequences, and for the strain 1390, sequences of the eae and esp regions are related to those of other AEEC, in particular, strains presenting a beta intimin allele, such as the rabbit AEEC.

Distribution of a novel locus called Paa (porcine attaching and effacing associated) among enteric Escherichia coli

Using TnphoA transposon insertion mutagenesis, we found a porcine EPEC (PEPEC) mutant demonstrating as inability to induce AE lesions. The insertion was identified in a gene designated paa (porcine attaching and effacing associated). The distribution of paa in PEPEC O45 strains revealed that it was associated with presence of the eae and its AE phenotype in vivo. On examination of enteric E. coli isolates from humans and various animal species, a strong correlation with the presence of paa was found in EHEC O157:H7 and O26, and dog, rabbit, and pig eae-positive isolates, and to a lesser extent in human EPEC eae-positive isolates. Also, among porcine ETEC isolates, a strong association was found with the presence of LT encoded genes. In contrast, paa sequence was rarely found in enteric E. coli isolates lacking ETEC and AEEC virulence determinants. Thus, our results suggest that Paa could play a role in the AE mechanism and other mechanisms of enteric disease.

Effects of proteolysis and mechanism of gel weakening in heat-induced gelation of fish myosin

Addition of papain decreased the onset temperature and the rate at which G' developed during heat-induced gelation of arrowtooth flounder myosin. Frequency sweep results revealed that G' markedly decreased in proportion to the amount of papain added. However, use of E-64, a cysteine proteinase inhibitor, reversed the effects of papain and protected myosin heavy chain from degradation. DSC thermograms indicated papain significantly decreased the enthalpy required to induce myosin denaturation without significant changes in onset and maximum transition temperatures. Thermal denaturation kinetics indicated decreases in both the activation energy and the rate of myosin denaturation. CD studies revealed a rapid decrease in alpha-helical content, indicating the initial degradation of myosin molecules mostly occurred in the tail region. These results suggested that proteolysis affected thermal properties and reactivity of myosin during heating. Although myosin gel could be formed, structural disruption resulted in lower gelling ability and rigidity of the formed gel.

Physicochemical changes and mechanism of heat-induced gelation of arrowtooth flounder myosin

Physicochemical changes of myosin during heating were investigated to elucidate the mechanism of heat-induced gelation of arrowtooth flounder (ATF) myosin at high ionic strength. Changes in dynamic properties indicated ATF myosin formed a gel in three different stages as shown by the first increase in G' (storage modulus) at 28 degrees C, followed by the decrease at 35 degrees C and the second increase at 42 degrees C. DSC thermogram showed the onset of myosin denaturation at 25 degrees C with two maximum transition temperatures at 30 and 36 degrees C. The decrease in alpha-helical content indicated ATF myosin began to unfold at 15 degrees C and the unfolding continued until it reached 65 degrees C. Turbidity measurement showed myosin began to aggregate at 23 degrees C and the aggregation was complete at 40 degrees C. Surface hydrophobicity increased consistently in the temperature range studied, 20-65 degrees C. Sulfhydryl contents decreased significantly at 20-30 degrees C due to the formation of disulfide linkages but remained constant at temperatures >30 degrees C. ATF myosin was shown to be extremely sensitive to heat, resulting in denaturation at lower temperature than other fish myosin. Denaturation was initiated by unfolding of the alpha-helical region in myosin followed by exposure of hydrophobic and sulfhydryl residues, which are subsequently involved in aggregation and gelation processes.

Rainbow trout (Oncorhynchus mykiss) cystatin C: expression in Escherichia coli and properties of the recombinant protease inhibitor

Cystatins are a superfamily of low Ki cysteine proteinase inhibitors found in both plants and animals. Cystatin C, a secreted molecule of this family, is of interest from biochemical and evolutionary points of view, and also has biotechnological applications. Recently we cloned and sequenced the cDNA for rainbow trout (Oncorhynchus mykiss) cystatin C [Li et al., 1998. Molecular cloning, sequence analysis and expression distribution of rainbow trout (Oncorhynchus mykiss) cystatin C. Comp. Biochem. Phys. B 121, 135-143]. To explore the relationship between protein structure and function of trout cystatin C, we established a bacterial system for expression of the protein. Trout cystatin C expressed in the cytoplasm of bacterial cells did not have detectable protease inhibitory activity. Activity was regained by Ni-NTA chromatography under denaturing conditions followed by dialysis-based refolding. Titration of purified cystatin C preparations with papain indicated that approximately 20% of the total protein had been converted to the active form after one refolding cycle. Expression levels were 3-5 mg/l. The protease-inhibitory properties of recombinant trout cystatin C were similar to those of human and chicken cystatin C derived from biological sources and recombinant cystatin C derived from rat and mouse genes. The Ki for papain was 1.2 x 10(-15) M, exhibiting the high affinity binding unique to this family of protease inhibitors.

[Staining of complete denture: a preliminary clinical study]

OBJECTIVE:To study the relation between staining of complete denture and drinking tea, coffee and smoking, and to evaluate the result of denture cleaning agent on removing stain of complete denture.METHODS:A survey of 176 patients with complete dentures were carried out, which included the history of drinking tea, coffee and smoking, the use of denture-cleaning agent and the times of daily use. Statistical analysis was performed to determine the relationship between staining of denture and the above factors. RESULTS:The results showed (1)The longer the complete denture was weared, the more serious the staining. (2)Drinking tea and smoking were the main causes for denture staining. (3)Daily use of cleaning agent can effictively remove stain of denture. CONCLUSION:Change of life habit(drinking less tea and stop of smoking) and daily use of cleaning agent can reduce denture staining.

Histamine and biogenic amine production by Morganella morganii isolated from temperature-abused albacore

Histamine-producing bacteria were isolated from albacore stored at 0, 25, 30, and 37 degrees C. They were screened using Niven's differential medium, and their histamine production was confirmed by high-pressure liquid chromatography analysis. The optimum temperature for growth of histamine-producing bacteria was 25 degrees C. The bacterium producing the highest level of histamine was isolated from fish abused at 25 degrees C. It was identified as Morganella morganii by morphological, cultural, biochemical, and antimicrobial characteristics and by the Vitek microbial identification system. The M. morganii isolate was inoculated into tuna fish infusion broth medium, and the effect of temperature was determined for microbial growth and formation of histamine and other biogenic amines. The isolate produced the highest level of histamine, 5,253 ppm, at 25 degrees C in the stationary phase. At 15 degrees C, histamine production was reduced to 2,769 ppm. Neither microbial growth nor histamine formation was detected at 4 degrees C. To determine whether the isolate can also produce other biogenic amines that can potentiate histamine toxicity, production of cadaverine, putrescine, serotonin, tryptamine, tyramine, phenylethylamine, spermidine, and spermine by the isolate was also monitored. Cadaverine, putrescine, and phenylethylamine were detected with microbial growth in the tuna fish infusion broth medium. The optimum temperature for cadaverine, putrescine, and phenylethylamine formation was found to be 25 degrees C, as it was for histamine.

TCM treatment with the modified wendan tang in 40 cases of melancholia

Melancholia is a syndrome caused by emotional stress and stagnation of qi, involving the liver, affecting the heart and spleen, and leading to disharmony of qi of the zang-fu organs. Because of the complicated condition, it is not easy to determine the therapeutic principles. In this series of 40 cases, the modified Wen Dan Tang (Decoction for Clearing Away Gallbladder-Heat) was used for the treatment. Of them, 19 cases were cured, 16 improved, and 5 failed, with total effective rate of 87.5%.

[Comparative study on osteogenesis of three types growth factors recombination artificial bones]

OBJECTIVE

To compare the osteogenesis of recombination artificial bones, which are bovine deproteined bone (bDPB) and bovine bone morphogenetic protein (bBMP), combined with tumor necrosis factor alpha (TNF alpha), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF) respectively.

METHODS

One hundred trephined skull bone defects in fifty rabbits were divided into four groups, which implanted with bDPB/bBMP/TNF alpha, bDPB/bBMP/bFGF, bDPB/bBMP/EGF, and bDPB/bBMP respectively. X-ray and histological changes were observed in the 1st, 2nd, 4th, 6th, 8th weeks after implantation. The content of 35S and 45Ca and ash weight were measured at 10 and 42 days after operation.

RESULTS

The osteogenesis of bDPB/bBMP/TNF alpha group was stronger than that of bDPB/bBMP/bFGF group(P < 0.01), while bDPB/bBMP/bFGF group was stronger than that of bDPB/bBMP/EGF(P < 0.01). No significant statistical difference were found between bDPB/bBMP/EGF and bDPB/bBMP(P > 0.05).

CONCLUSION

TNF alpha combined with bBMP and carrier can stimulate bone formation and increase the volume of new bone in vivo. It suggests that bDPB/bBMP/TNF alpha is a valuable biomaterial of bone graft.

Improving high-resolution MR bold venographic imaging using a T1 reducing contrast agent

Recently, a new imaging method was proposed by Reichenbach et al (Radiology 1997;204:272-277) to image small cerebral venous vessels specifically. This method, referred to as high-resolution blood oxygen level-dependent venography (HRBV), relies on the susceptibility difference between the veins and the brain parenchyma. The resulting phase difference between the vessels and the brain parenchyma leads to signal losses over and above the usual T2* effect. At 1.5 T, a rather long TE (roughly 40 msec) is required for this cancellation to become significant, leading to enhanced susceptibility artifacts and a long data acquisition time. In this study, we examine the utility of incorporating a clinically available T1 reducing contrast agent, Omniscan (Sanofi Winthrop Pharmaceuticals, NY, NY), with the HRBV imaging approach to reduce susceptibility artifacts and imaging time while maintaining the visibility of cerebral veins. Using a double-dose injection of Omniscan, we were able to reduce TE from 40 to 25 msec. This led to a decrease in TR from 57 to 42 msec, allowing a 26% reduction in data acquisition time while maintaining the visibility of cerebral venous vessels and reducing susceptibility artifacts. J. Magn. Reson. Imaging 1999;10:118-123, 1999.

Raman spectroscopic study of changes in fish actomyosin during setting

Actomyosins (AMs) isolated from tilapia, lemon sole, ling cod, and rock fish were heated at 40 degrees C, and structural changes in AMs were investigated using Raman spectroscopy to elucidate low-temperature gelling phenomenon, that is, "setting", of surimi. The following conformational transitions were observed in lemon sole, ling cod, and rock fish gels during setting: a slow unfolding of alpha-helix and exposure of hydrophobic amino acid residues occurring in long-time incubation at 40 degrees C, thereby forming hydrophobic interactions among AM molecules. In addition, the most frequent conformation in disulfide bonds was gauche-gauche-trans (g-g-t) form in the set gel. On the other hand, tilapia AM did not form a gel with heating at 40 degrees C, its alpha-helical structure in the myosin being far more stable than that of the other species. The heat resistance of the tight alpha-helix may prevent the gelation of tilapia AM. It is, therefore, likely that the unfolding of the alpha-helix of myosin is a prerequisite for gelation of AM during setting.

Intervertebral disk appearance correlated with stiffness of lumbar spinal motion segments

BACKGROUND AND PURPOSE

Because it diminishes the stiffness of the intervertebral disk, disk degeneration results in abnormal motions of the spine. Therefore, disk degeneration associated with back pain may indicate spinal fusion. The purpose of this study was to correlate the MR appearance and stiffness of lumbar intervertebral disks.

METHODS

Eighty-two lumbar spinal segments were imaged with MR. The intervertebral disks were classified as: 1) normal, 2) having transverse or concentric tears of the annulus fibrosus if MR imaging showed only these changes, 3) having radial tears of the annulus fibrosus if MR imaging showed high-intensity zones in the annulus fibrosus or reduced signal intensity in the disk characteristic of radial tears, or 4) having advanced degeneration if MR imaging showed markedly reduced height, large osteophytes, or both. The rotation occurring from the application of a 6.6-Newton-meter (Nm) moment of axial rotational torque was measured kinematically. Average stiffness, in Nm/degree, was calculated as the ratio of the torque to the rotation.

RESULTS

Stiffness averaged 7.0 Nm/degree for the normal group; 1.9 Nm/degree for the disks with concentric or transverse tears; 1.7 Nm/degree for disks with radial tears; and 3.1 Nm/degree for disks with advanced degeneration. The differences were statistically significant.

CONCLUSION

Concentric, transverse, and radial tears of the intervertebral disk indicate reduced stiffness of the intervertebral disk and increased motions for a unit of applied torque. The most severely reduced stiffness was found in disks with radial tears of the annulus fibrosus. With collapse of the disk space, stiffness increases.

Cloning and characterization of the esp region from a dog attaching and effacing Escherichia coli strain 4221 and detection of EspB protein-binding to HEp-2 cells

The espA, espB and espD genes from enteropathogenic Escherichia coli were previously shown to be essential for triggering the signal transduction in infected host cells. We have cloned and determined the nucleotide sequences of the espA, espB and espD homologues from an E. coli strain (4221) isolated from a dog which manifested the attaching and effacing lesions in the small intestine. This strain is designated as a dog enteropathogenic E. coli. When comparing predicted amino acid sequences to those of the corresponding proteins from enteropathogenic E. coli O127, enterohemorrhagic E. coli serotype O26, enterohemorrhagic E. coli O157 and rabbit enteropathogenic E. coli, the EspADEPEC protein showed the same level of similarity (75% identity) with EspA of enteropathogenic E. coli O127 and rabbit enteropathogenic E. coli. The EspBDEPEC protein showed the highest similarity with the EspB of enteropathogenic E. coli O127 (99% identity). The EspDDEPEC protein showed 88% identity with the EspDEPEC. We constructed and purified a maltose-binding fusion protein containing the product of the entire espBDEPEC gene of the dog enteropathogenic E. coli strain 4221. Purified maltose-binding protein-EspBDEPEC fusion protein was shown to bind efficiently to HEp-2 cells in a localized fashion as shown by immunofluorescence microscopy. In addition, when the dog enteropathogenic E. coli strain 4221 was grown in tissue culture medium (DMEM) supplemented with serum, a secreted 36-kDa protein was identified by immunoblot analysis using a polyclonal antiserum against the maltose-binding protein-EspBDEPEC fusion protein.

Effects of intrathecal galanin on nociceptive responses in rats with mononeuropathy

The present study was performed on rats with experimental mononeuropathy induced by left common sciatic nerve loose ligation. Unilateral sciatic nerve loose ligation induced decreases of the hindpaw withdrawal latency to the hot-plate test, cold-plate test and the Randall Selitto test. Sciatic nerve loose ligation induced hyperesponsiveness to touch at room temperature also. Intrathecal administration of either 3 or 6 nmol of galanin, but not 1 nmol, induced significant bilateral increases in hindpaw withdrawal latencies to the hot-plate test, cold-plate test and the Randall Selitto tests in rats with left mononeuropathy. The results indicate that galanin may play important roles in transmission of presumed nociceptive information in the spinal cord of mononeuropathic rats.

Retention of polysomy at 9p23-24 during karyotypic evolution in human breast cancer cell line COLO 824

Somatic genetic alterations of 9p have been seen in a wide range of human cancers, including breast cancer. Loss of heterozygosity analysis of primary breast cancer tumors has revealed a high frequency of deletion of DNA from 9p21-22 encompassing the MTSI (P16/CDKN2A) gene. We report the approximately tenfold increase in copy number of DNA from 9p23-24, which is far distal to P16/CDKN2A in female breast cancer cell line COLO 824, as revealed by fluorescence in situ hybridization, comparative genomic hybridization, and microsatellite analysis. Amplification of DNA has been reported previously to encompass multiple sites of the genome of the breast cancer cell, but increase in DNA copy number has not been seen in distal 9p.

Measuring diffusion of solutes into intervertebral disks with MR imaging and paramagnetic contrast medium

BACKGROUND AND PURPOSE

Experimental studies have shown that solutes diffuse more slowly into degenerated intervertebral disks than into normal disks. A noninvasive clinical study of diffusion in intervertebral disks is not generally available. Our purpose was to evaluate contrast-enhanced MR images to study diffusion in normal and degenerated lumbar intervertebral disks.

METHODS

The change in signal intensity (as a proportion of baseline signal intensity) was calculated in lumbar intervertebral disks on MR images obtained before and after injection of intravenous contrast medium in 15 patients with low back pain. The intervertebral disks were classified as normal or degenerated on the basis of the MR appearance. Postoperative disks and degenerative intervertebral disks with a "high-intensity zone" were excluded. The changes in signal intensity as a proportion of baseline signal intensity were compared in degenerated disks and normal disks and the differences tested for statistical significance.

RESULTS

After intravenous administration of a gadolinium complex, signal intensity in normal intervertebral disks increased an average of 36% of baseline. In intervertebral disks with signs of degeneration, it increased an average of 21% of baseline. The difference was significant.

CONCLUSION

The study shows that diffusion into normal human lumbar intervertebral disks can be evaluated with MR imaging combined with intravenous contrast medium. With suitable MR techniques, the relationship between diffusion and disk degeneration, and the effect of trauma, drugs, and nutrition on disk degeneration can be studied noninvasively.

Molecular cloning, sequence analysis and expression distribution of rainbow trout (Oncorhynchus mykiss) cystatin C

Cystatin C is one of a family of proteinase inhibitors of cathepsins and other cysteine proteinases. Among warm-blooded vertebrates, small functional regions of cystatin amino acid sequences are well conserved among species, but major portions of cystatin amino acid sequences vary evolutionarily. Although considerable attention has been given to mammalian and avian cystatins, little data exist on cystatins from other vertebrates. A cDNA clone for trout cystatin C was isolated from a lambda gt11 cDNA library of rainbow trout (Oncorhynchus mykiss) liver. An apparently full-length cDNA clone of 674 bp encoding 132 amino acid residues was obtained. Sequence analysis indicated that trout cystatin C contains an N-terminal signal sequence extension of 21 amino acids and a mature sequence of 111 amino acid residues, with amino acid residues conserved in functional regions relative to mammalian and avian cystatin C. Using cloned cDNA as a probe, we investigated expression of the cystatin C gene in trout tissues, several cell lines of trout liver or liver tumor, and cell cultures of liver tumor origin. Cystatin C mRNA was in high abundance in trout embryo tissue, a tumor-derived liver cell line and some normal adult tissues. Southern hybridization analysis indicated one copy of the trout cystatin C gene per haploid genome, and sequence comparisons indicated considerable divergence in large portions of the coding region of the trout cystatin C gene relative to a variety of species.

New piperazinyl polyazacyclophane scaffolds, libraries and biological activities

Four novel unsymmetric piperazinyl polyazacyclophane scaffolds 1-4 were synthesized in high yields by an efficient cyclization strategy. Twenty-six libraries 12-37 (total 16,000 compounds) were generated by a solution-phase combinatorial approach from 1-4 and thirty-eight functional groups. Potent antibacterial and HIV-1 tat/TAR protein-RNA disrupting activities were discovered.

Discovery of novel pyridinopolyamines with potent antimicrobial activity: deconvolution of mixtures synthesized by solution-phase combinatorial chemistry

A 1638-member pyridinopolyamine library, consisting of 13 sublibraries of 126 members prepared by a solution-phase approach, was completely deconvoluted from orthogonally protected intermediates by a combination of iterative and positional scanning procedures. Antibacterial assays against Streptococcus pyogenes and Escherichia coli imp- and a Candida albicans yeast specificity assay were employed to follow the activity of sublibraries. Screening of the 13 sublibraries, which were prepared by a synthetic method that places the differentiating functionality in a selected position A (secondary amine), at the end of the synthesis (fix last), provided several first-round activities. Subsequently, six single pyridinopolyamines (2-7) were prepared where the first-round winner, a hydrogen atom, is in the first deconvoluted position and the remaining three positions contained the same functionalities. The range of antibacterial and yeast activities of these single compounds suggested that a more active and selective compound may be discovered by completely deconvoluting the first-round active sublibraries. Pyridinopolyamine positions B (secondary benzylamine) and C (primary benzylamine) were then sequentially positionally scanned with a set of six meta-substituted benzyl functionalities to generate two sets of second/third-round sublibraries, containing 21 or 36 compounds in each sublibrary, respectively. High-throughput screening yielded sublibraries 15, 18, and 21 with MICs of 1-5 microM against S. pyogenes and E. coli imp-. Using rounds 1 and 2/3 screening data, two sets of single compounds (22-27) and (28-32) with the combination of m-(trifluoromethyl)-benzyl group at position C and m-(trifluoromethyl)benzyl or m-methylbenzyl group at position B with position D (primary benzylamine) fixed were synthesized in the fourth round deconvolution. Subsequently, broader screening of deconvoluted compounds against a tier II panel of wild-type bacteria identified eight compounds (5, 7, 27, and 29-32) with approximately 100-fold greater selectivity for Gram-positive than Gram-negative bacteria. Thus, S. pyogenes, S. pyogenes (wild-type), Streptomyces aureus, and Enterococcus faecalis were inhibited at MICs of 1-12 microM, whereas MICs for E. coli, Klebsiella pneumoniae, Proteus vulgaris, and Pseudomonas aeruginosa were > 100 microM. These eight compounds were not active (> 100 microM) against fungus C. albicans.

Controlling receptor-ligand contact to examine kinetics of T cell activation

A method for controlling the contact of cell-surface receptors with immobilized ligands has been developed. Cells are trapped in an asymmetric liquid film that can be quantitatively thinned by reducing the film's capillary pressure. Ligands adsorbed to the liquid-solid interface are forced into increasingly tighter contact with the cells as the air-liquid interface is drawn down. Controlling the degree of thinning allows study of repulsive forces, and controlling its time course produces a definite time 0 for analyzing signal transduction. This system was tested by examining the time course of calcium mobilization in T cells upon activation with anti-CD3 antibody at different dilutions and ionic strengths. The averaged calcium transient of the responding cells was essentially the same for each condition. However, the fraction of responding cells decreased with anti-CD3 dilution, and indicated that the critical ligand density for T cell activation lies between approximately 35 and 70 molecules of anti-CD3 per microm2. Decreasing the medium's ionic strength from the normal value of 157 mM to 57 mM did not affect either the average calcium response profile or the fraction of responding cells, but strongly affected receptor-ligand contact, decreasing the percent of spontaneous activation from 38% to 5%. Such an imposed decrease sets the stage for film thinning to impose much greater control of receptor-ligand contact.

Cloning and characterization of the eae gene from a dog attaching and effacing Escherichia coli strain 4221

We have cloned and determined the nucleotide sequence of the eae gene from a dog attaching and effacing (A/E) Escherichia coli (DEPEC) strain 4221. When comparing the predicted amino acid sequence of the eaeDEPEC to that of the Eae proteins from enteropathogenic E. coli (EPEC), enterohaemorrhagic E. coli O157:H7 (EHEC), Citrobacter freundii biotype 4280, and a swine A/E E. coli strain O45 (PEPEC), the overall sequence identity was 84, 81, 83 and 83%, respectively, with the greatest divergence at the C-terminal end, the putative receptor-binding portion. Interestingly, the DEPEC Eae shares the greatest identity at the C-terminal region with the Citrobacter freundii Eae protein. We have constructed and purified a maltose-binding fusion protein (MBP) containing the product of the entire eae gene of the DEPEC strain 4221. Binding of MBP-EaeDEPEC fusion protein to HEp-2 cells was demonstrated by immunofluorescence microscopy. In addition, the Eae protein of DEPEC (4221) demonstrated a strong serological relationship with that of EPEC (E2348/69) as observed using a polyclonal antiserum against MBP-EaeDEPEC fusion protein.