Immunochemical and structural characterization of a serotype-specific polysaccharide antigen from Actinobacillus actinomycetemcomitans Y4 (serotype b).

A serotype-specific polysaccharide antigen of Actinobacillus actinomycetemcomitans Y4 (serotype b) was extracted from whole cells by autoclaving. The extract was purified by chromatography on DEAE-Sephadex A-25 and Sephacryl S-300 columns. The purified polysaccharide antigen formed a single precipitin line with anti-type b serum but not with anti-type a serum and anti-type c serum. The antigen was composed of 43.9% L-rhamnose, 49.1% D-fucose, and a trace amount of fatty acid. Methylation analysis, Smith degradation, and optical rotation data showed that the antigen was a polymer consisting of a disaccharide repeating unit, ----3)-alpha-D-fucopyranosyl-(1----2)-beta-L-rhamnopyranosyl-(1----. In quantitative precipitin inhibition tests, D-fucose and L-rhamnose showed very low inhibition, but the partial hydrolysate of the purified antigen was an effective inhibitor, suggesting that the serotype b specific antiserum recognizes the larger oligosaccharide units.     

Liver metastasis from rectal cancer with prominent intrabile duct growth

Intrabiliary growth of liver metastases from colorectal cancer has rarely been studied. A surgically resected case of a metastatic liver tumor with prominent intrabiliary growth derived from rectal cancer is reported. The patient was a 62-year-old man who had received a low anterior resection for rectal cancer in March 2000. He was re-admitted due to obstructive jaundice in January 2003, and was diagnosed with hepatic malignancy in segment II of the liver with an intrabiliary tumor extending from the intrahepatic bile duct of segment II to the common hepatic duct. He underwent a left hepatectomy, a partial resection of segment VI, and an extrahepatic bile duct resection with reconstruction of the biliary tract. In the resected specimen, there were whitish tumors of 3 cm and 1.5 cm in diameter in segments II and VI, respectively, and an intrabiliary tumor originating from the main tumor in segment II extended to the common hepatic duct. Both the liver tumors and the intrabiliary tumor consisted of a well- to moderately differentiated adenocarcinoma, which showed the same histological features as the rectal cancer. The immunohistochemical findings strongly supported that these tumors, including the intrabiliary growth, were liver metastasis from the rectal cancer. The intrabiliary invasion and growth of metastatic liver tumors has generally been overlooked, notwithstanding their frequently observed biological behavior. The present case is informative, and further investigation into this type of metastatic liver tumor may be warranted.     

Heterogeneity of the L-rhamnose residue in the outer core of Pseudomonas aeruginosa lipopolysaccharide, characterized by using human monoclonal antibodies.

Hybridoma cell lines producing human monoclonal antibodies (MAbs) MH-4H7 and KN-2B11 [immunoglobulin M (lambda)] which bound to the outer core region of Pseudomonas aeruginosa lipopolysaccharide (LPS) were established by cell fusion of human peripheral lymphocytes with human-mouse heteromyeloma SHM D-33. Both binding specificity experiments with a series of LPS-defective mutants derived from P. aeruginosa PAC1R (P. S. N. Rowe and P. M. Meadow, Eur. J. Biochem.132:329-337, 1983) and competitive enzyme immunoassay experiments with monosaccharides demonstrated that alpha-L-rhamnose residues in the outer core of LPS might be in part an epitope. The MAbs specifically bound to clinical isolates belonging to Homma serotypes A, F, G, and K at a frequency of 70 to 86% and to serotypes H and M isolates at about 50%. They did not bind to any isolates of serotype B, E, and I tested. This evidence indicates that L-rhamnose and probably its neighboring residues in the other core of P. aeruginosa are heterogeneous in some association with the O serotype.     

Biochemical and immunobiological properties of lipopolysaccharide (LPS) from Bacteroides gingivalis and comparison with LPS from Escherichia coli.

Lipopolysaccharides (LPSs) were isolated from Bacteroides gingivalis and Escherichia coli by the phenol-water and butanol-water procedures. The phenol-water-extracted LPS from B. gingivalis 381 was composed of 46% carbohydrate, 23% hexosamine, 18% fatty acid, and 5% protein. The major component sugars of this preparation were glucose, glucosamine, rhamnose, galactose, galactosamine, and mannose, and their molecular ratio was 1:0.9:0.7:0.6:0.6:0.4, respectively. Neither heptose nor 2-keto-3-deoxyoctonate was detected. The butanol-water-extracted LPS from this strain was composed of 76% glucose, 7% fatty acid, and 13% protein, and it was associated with a number of polypeptides (13 to 56 kilodaltons). The main fatty acid of both LPS preparations was palmitic acid. It was found that biological activities of LPS from B. gingivalis were comparable to those of LPS from E. coli in terms of activation of the clotting enzyme of Limulus amebocyte lysate, mitogenicity, polyclonal B cell activation, and stimulation of interleukin 1 production in BALB/c mice. Furthermore, LPS-nonresponsive C3H/HeJ spleen cells were found to yield good mitogenic responses to both phenol-water-extracted LPS and butanol-water-extracted LPS from B. gingivalis or butanol-water-extracted LPS from E. coli. On the other hand, spleen cells from LPS-responsive C3H/HeN mice responded well to all these LPS preparations.     

HLA-DP and susceptibility to insulin-dependent diabetes mellitus in Japanese

ABSTRACT: Human leukocyte antigen (HLA) genes are candidates for susceptibility genes in insulin-dependent diabetes mellitus (IDDM). Recently, the association of DR and DQ with IDDM has been reported, but the role of HLA-DP genes remains uncertain. To address the question, we analyzed the DPB1 gene of 20 Japanese IDDM patients and 30 control subjects using a combination of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis (PCR-RFLP method). DPB1*0501 was the most frequent allele both in Japanese patients and control subjects. There was no appreciable association between IDDM and the DPB1 allele in Japanese. The absence of association between IDDM and DP, in spite of the known association between this disease and both DR and DQ, suggests that the HLA locus (loci) telomeric to DP encodes susceptibility to IDDM.     

Differential effect of brain-derived neurotrophic factor on high-threshold mechanosensitivity in a rat neuropathic pain model

We investigated the effect of the systemic infusion of brain derived neurotrophic factor (BDNF) on the behavioral response in a rat neuropathic pain model. One microgram per hour infusion of BDNF significantly attenuated mechanical hyperalgesia tested by the pin-prick test, however, 20 microg/h-BDNF infusion, on the contrary, enhanced the response. Neither 0.5 nor 10 microg/h-BDNF infusion influenced the mechanical hyperalgesia. Mechanical allodynia and thermal hyperalgesia, tested using a von Frey filament (23.0 mN) and the plantar test, were not influenced by BDNF treatment. These data suggest that systemic BDNF treatment can specifically alter high-threshold mechanosensitivity.     

HLA-B40, B18, B27, and B37 allele discrimination using group-specific amplification and SSCP method

We developed a system for discriminating HLA-B40, B18, B27, and B37 alleles using a two-step PCR method followed by SSCP analysis. Fragments (0.8 kb) including exon 2, intron 2, and exon 3 were amplified in the first PCR. We used two sets of primers, one specific for HLA-B60-related alleles and the other specific for HLA-B6l-related, B18, B27, and B37 alleles. No amplifications of other class I genes or pseudogenes were observed. In the second PCR, exon 2 and exon 3 were amplified separately, using diluents of the first PCR products as templates. HLA-B6l-related, B18, B27, B37, and B60-related alleles were clearly discriminated in the SSCP analysis of the second PCR products. In a population study in which B6l alleles were analyzed, B^*4003 was detected in two Japanese individuals in addition to two B6l alleles previously reported to occur in Japanese, B^*4002 and B^*4006. The relative frequencies of B^*4002, B^*4006, and B^*4003 in Japanese were 58, 35, and 6%, respectively. The individuals having B^*4003 are the first non-South Americans in whom this allele has been detected. The SSCP banding patterns of 18 HLA-B60-positive Japanese population samples were identical to those of a B^*40012 sample for both exon 2 and exon 3. We also demonstrated that the B37 allele occurring in some Japanese is B^*3701.     

A role for the P1 anchor residue in the thermal stability of MHC class II molecule I-Ab

The thermal stability of the murine MHC class II molecule, I-A(b), in complex with invariant chain-derived peptide (CLIP) and an antigenic peptide derived from the alpha subunit of the I-E molecule (Ealpha) at mildly acidic and neutral pH were analyzed using circular dichroism (CD). The stability of I-A(b)-CLIP was increased by a single amino acid substitution in the P1 anchor residue, from Met of CLIP to Phe of Ealpha, similar, in this respect, to I-A(b)-Ealpha. This indicates that hydrophobic interaction in the P1 pocket is critical and plays a primary role in the stability of the complex. The structural models of I-A(b)-peptides based on the crystal structure of I-A(d) might explain the increased stability and the preference for hydrophobic residues in this site. Taken together with what is known of the resident stability at a mildly acidic pH, the difference in stability would closely correlate with the ability of MHC class II to exchange peptides from CLIP to antigenic peptides in the endosome.     

Undifferentiated Carcinoma of the Parotid Gland in a 10-Month-old Child

Malignant salivary gland tumors in children are very rare. This report describes the autopsy of a child with parotid gland cancer. The patient, a 10 month old girl, was admitted to the Nagoya First Red Cross Hospital with facial nerve palsy. lncisional biopsy of a post-auricular tumor was performed, and undifferentiated carcinoma was diagnosed. The patient died 6 months later of respiratory failure due to pulmonary lymphangitis carcinomatosis. Light and electron microscopic and immunohistochemical examinations of the tumor tissue were performed. The tumor cells were arranged in a medullary, sheet-like manner. Keratinization or mucus lakes were not observed. PAS-alcian blue staining demonstrated intracytoplasmic mucus as granules, and also small intercellular droplets of mucus that might otherwise have been unnoticed. Ultrastructurally, some of the tumor cells had tonofilament-like keratin filaments, and also small hollow spaces bounded by microvilli and containing secretory particles. These were stained by antisera against CEA and keratin. These findings are suggestive of differentiation to mucoepider-moid carcinoma. We also review and discuss malignant salivary tumors of epithelial origin in children. Acta Pathol Jpn 40: 149–152, 1990.     

Cytokeratin expression in normal human thymus at different ages

Subsets of thymic epithellal cells were examined Immuno-histochemically to determine whether or not their pheno-types change during thymic growth and at early involution in terms of cytokeratin (CK) expression. Five monoclonal antibodies specific for CK4, CK8, CK13, CK18 and CK19 were used and applied for 16 neonatal, three Infantile and one adult thymus speeimen, which had been obtained at autopsy, that were normal macroscopically and microscopicaily. CK4, CK8, CK13, CK18 and CK19 were expressed simultaneously in the cortex, medulla and subcapsular area with the exception of CK4, which showed expression on the adult thymus. Light and electron microscopy showed that CK8 and CK19 expression was overlapped. Thus, It was thought that CK8 and CK19 formed complexes in the cytoplasm of thymic epithelial cells. The Immunoreactivity to CK4, CK13 and CK18 were attenuated or disappeared In the subcapsular area during the early involution stage. Interestingly, two patterns of CK18 expression were observed in the neonatal and Infantile thymus tissues, which Indicated that the thymic microenvironment was changeable even under normal conditions.