Protective effects of baicalein and wogonin against benzo[a]pyrene- and aflatoxin B(1)-induced genotoxicities

To evaluate the protective effects of baicalein and wogonin against benzo[a]pyrene- and aflatoxin (AF) B(1)-induced toxicities, the effects of these flavonoids on the genotoxicities and oxidation of benzo[a]pyrene and AFB(1) were studied in C57BL/6J mice. Baicalein and wogonin reduced benzo[a]pyrene and AFB(1) genotoxicities as monitored by the umuC gene expression response in Salmonella typhimurium TA1535/pSK1002. Baicalein added in vitro decreased liver microsomal benzo[a]pyrene hydroxylation (AHH) activity with an ic(50) of 33.9 +/- 1.4 microM at 100 microM benzo[a]pyrene. Baicalein also inhibited AFQ(1) and AFB(1)-epoxide formation from AFB(1) (50 microM) oxidation (AFO) with ic(50) values of 22.8 +/- 1.4 and 5.3 +/- 0.8 microM, respectively. However, the in vitro inhibitory effects of wogonin on AHH and AFO activities in liver microsomes were less than those of baicalein as inhibition by 500 microM wogonin was only about 51-65%. Treatment of mice with liquid diets containing 5 mM baicalein and wogonin resulted in 22 and 49% decreases in hepatic AHH activities, respectively. Baicalein treatment resulted in 39 and 32% decreases in AFQ(1) and AFB(1)-epoxide formation from liver microsomal AFO, respectively. Wogonin treatment resulted in 39 and 47% decreases in AFQ(1) and AFB(1)-epoxide formation, respectively. A 1-week pretreatment with wogonin significantly decreased hepatic DNA adduct formation in mice treated with 200 mg/kg of benzo[a]pyrene via gastrogavage. These in vitro and in vivo effects suggested that baicalein and wogonin might have beneficial effects against benzo[a]pyrene- and AFB(1)-induced hepatic toxicities and that wogonin had a stronger protective effect in vivo.

E-cadherin gene mutations frequently occur in synovial sarcoma as a determinant of histological features

Synovial sarcoma is a mesenchymal tumor that has an epithelial character and two major histological subtypes, the biphasic type and the monophasic fibrous type. However, the mechanisms involved in its epithelial differentiation are unknown, and furthermore, the determinants for histological subtype in synovial sarcoma remain unclear. In this study, we immunohistochemically examined E-cadherin expression and screened for genetic alterations in the E-cadherin gene from exon 4 to exon 9 in 49 cases of synovial sarcoma. In addition, we also examined the mRNA expressions of E-cadherin and Snail, a direct repressor of E-cadherin gene expression, by reverse transcriptase-polymerase chain reaction in 20 samples of frozen material. Immunohistochemical E-cadherin membranous expression was observed in 12 cases (24.5%), and was predominant in biphasic tumors. Single-strand conformation polymorphism analysis followed by DNA direct sequencing revealed 15 missense E-cadherin mutations in 12 cases (24.5%: monophasic, 11 of 42; biphasic, 1 of 6; poorly, 0 of 1) and 7 silent mutations (14.3%) in 7 cases. Ten of the 12 cases with E-cadherin missense mutations did not show E-cadherin membranous expression. Reverse transcriptase-polymerase chain reaction demonstrated E-cadherin and Snail mRNA expressions in 14 cases (70%) and in all cases, respectively. E-cadherin gene expression was inactivated by missense mutations in three of the eight cases (37.5%) of monophasic fibrous tumors that showed E-cadherin mRNA expressions. The E-cadherin gene was potentially inactivated in a significant number of synovial sarcomas. E-cadherin dysfunction because of its mutation in the central region of the molecule was associated with its decreased immunohistochemical expression and histological fibroblastic and spindle-shaped features of monophasic tumors. Thus, E-cadherin gene mutation may be one of the determinants of histological subtype in synovial sarcoma.

Immunohistochemical analysis of E-cadherin, alpha-catenin, beta-catenin, gamma-catenin, and neural cell adhesion molecule (NCAM) in chordoma

AIMS

The epithelioid features seen in chordoma are unique among mesenchymal tumours. However, no detailed analysis regarding cell-cell communication has been conducted in this epithelioid tumour. The aims of this study were to investigate cell-cell communication in chordoma.

METHODS

By means of immunohistochemical techniques that incorporated a panel of monoclonal antibodies against cell adhesion molecules (CAMs), including E-cadherin, alpha-catenin, beta-catenin, gamma-catenin, and neural cell adhesion molecule (NCAM), the expression of CAMs was studied in 15 specimens of chordoma and eight specimens of chondrosarcoma.

RESULTS

Most chordoma specimens showed some positive immunoreactivity for all the CAMs examined. For the various CAMs investigated, between two and five cases showed diffuse immunoreactions, indicating well preserved expression. Well preserved expression of all the CAMs examined was limited to only one case, thus indicating that the expression of CAMs was decreased in most of the chordoma specimens; however, no significant correlation was found between the decreased expression of CAMs and the histological grade of malignancy, cellular growth pattern, or clinical parameters in chordoma. In chondrosarcoma, only a few specimens showed positive immunoreactivity for CAMs and the expression of E-cadherin, beta-catenin, gamma-catenin, and NCAM was seen more frequently in the chordoma specimens than in the chondrosarcoma specimens.

CONCLUSIONS

These results suggest that the expression of CAMs is associated with the formation and maintenance of chordoma tissue architecture, just as it is in other epithelial tumours or normal tissue. Immunohistochemistry for CAMs was found to be of diagnostic value for discriminating chordoma from chondrosarcoma, and these markers could be used along with the cytokeratins, which are already used for this purpose.

Metabolic gene polymorphism frequencies in control populations

Using the International Project on Genetic Susceptibility to Environmental Carcinogens (GSEC) database containing information on over 15,000 control (noncancer) subjects, the allele and genotype frequencies for many of the more commonly studied metabolic genes (CYP1A1, CYP2E1, CYP2D6, GSTM1, GSTT1, NAT2, GSTP, and EPHX) in the human population were determined. Major and significant differences in these frequencies were observed between Caucasians (n = 12,525), Asians (n = 2,136), and Africans and African Americans (n = 996), and some, but much less, heterogeneity was observed within Caucasian populations from different countries. No differences in allele frequencies were seen by age, sex, or type of controls (hospital patients versus population controls). No examples of linkage disequilibrium between the different loci were detected based on comparison of observed and expected frequencies for combinations of specific alleles.

Secondary malignant giant-cell tumour of bone: molecular abnormalities of p53 and H-ras gene correlated with malignant transformation

AIMS

We report two cases of secondary malignant giant-cell tumour occurring without irradiation therapy. To elucidate the mechanism of malignant transformation in this tumour, we searched for the molecular abnormalities of p53, MDM2 and the H-ras genes.

METHODS AND RESULTS

These cases were retrieved after a review of 103 cases of primary giant-cell tumour of bone, registered in our institute. One case occurred in the distal femur of a 42-year-old female after surgical curettage, while the other arose in the acetabulum of a 25-year-old male after en bloc resection. Microscopically, the malignant tumour in the distal femur was composed of a proliferation of ovoid or fusiform cells arranged in fascicles with high mitotic activities. The malignant transformed tumour in the acetabulum was made up of pleomorphic tumour cells with atypical mitoses. In the tumour of the distal femur, both p53 and H-ras mutations were detected. Abnormal nuclear accumulation of p53 protein and c-myc expression were also revealed by immunohistochemistry. In both cases, the recurrent malignant tumour over-expressed MMP-9 and revealed a higher MIB-1-labelling index compared with the primary conventional giant-cell tumour.

CONCLUSIONS

Our results suggest that multiple oncogene or tumour suppressor gene mutations may play an important role during malignant transformation in conventional giant-cell tumours.

Specific distribution of sialic acids in animal tissues as examined by LC-ESI-MS after derivatization with 1,2-diamino-4,5-methylenedioxybenzene

Simultaneous analysis of sialic acids has been a challenging target, because sialic acids having N- or O-acetyl, glycolyl, and sulfonic acid ester groups are labile during their release from carbohydrate chains and analytical procedures. In the present paper, we propose a method using high-performance liquid chromatography coupled with eletrospray ionization mass spectrometry (HPLC-ESI-MS). The method was evaluated by applying to the analysis of sialic acids in various tissues, especially digestive organs in mice and rats. The method was based on the in situ precolumn derivatization of sialic acids after releasing them by hydrolysis. The sialic acids were derivatized with 1,2-diamino-4,5-methylenedioxybenzene to form highly fluorescent quinoxaline derivatives. By using two different hydrolysis conditions (i.e., with 2 M acetic acid and with 0.1 M hydrochloric acid), both total sialic acids and sialic acid distributions were easily determined. We found that sialic acids showed characteristic distributions in the tissues of mice and rats. Further, HPLC-ESI-MS revealed that all the tissues examined in mice and rats commonly contained highly acetylated sialic acids and 8-O-sulfated N-acetylneuraminic acid.

Immunoexpression of neurofibromin, S-100 protein, and leu-7 and mutation analysis of the NF1 gene at codon 1423 in osteofibrous dysplasia

The NF1 (neurofibromatosis type 1, or von Recklinghausen disease) gene, is a tumor-suppressor gene, and its product, neurofibromin, down-regulates ras protein by its guanosine triphosphatase-activating protein (GAP)-related domain. Osteofibrous dysplasia (OFD) is characterized by fibroblast-like spindle cells and osseous tissue and is generally seen in the tibia or fibula during childhood. The precise nature of OFD remains controversial. Cosegregations of OFD and NF1 have been reported, and it has been surmised that OFD is associated with the NF1 gene. We studied the expressions of NF1 gene product (neurofibromin) and so-called Schwann cell markers (S-100 protein, Leu-7) in 17 cases of OFD immunohistochemically. Ten cases of fibrous dysplasia (FD) were also used for the purpose of comparison. Five OFD and 7 FD cases were analyzed for NF1 gene mutation at codon 1423, which is a GAP-related domain, by single-strand conformation polymorphism. Fibroblast-like cells of OFD showed the expression of neurofibromin (5 of 17), S-100 protein (9 of 17), and Leu-7 (5 of 17), and those of FD did not show these expressions, with the exception of 1 case that showed Leu-7 expression. Regarding the OFD cases, significant correspondence was found between cases showing expression of neurofibromin and S-100 protein, between cases showing expression of neurofibromin and Leu-7, and between cases showing expression of S-100 protein and Leu-7 (P < .01). NF1 gene mutation at codon 1423 was not detected in either the OFD (0 of 5) or FD (0 of 7) cases. These results seem to suggest the possible involvement of neurofibromin in the development of OFD, which is associated with the expression of Schwann cell markers (S-100 protein and Leu-7). Furthermore, NF1 gene mutation at codon 1423 did not seem to be related to OFD.

[A case of Hirayama's disease successfully treated by anterior cervical decompression and fusion]

The authors report the case of a 16-year-old boy with Hirayama's disease(juvenile muscular atrophy of unilateral upper extremity). The present history began about 6 months previously, when he noticed slowly progressive weakness with atrophy of the left hand and forearm. Neurological examination on admission revealed diffuse distribution of muscular atrophy including the left hypothenar, thenar, forearm, and triceps muscles. However, EMG studies identified neurogenic changes in both upper extremities. There was no long tract sign of objective sensory impairment. Plain spinal radiograms showed abnormal kyphosis of the cervical vertebrae. Cervical MR images in the neutral position demonstrated focal atrophy of the cervical cord at the C 5-6 vertebral levels. When the neck was flexed, the cervical cord was displaced anteriorly and was compressed over the posterior surface of the C 5-6 vertebral bodies. He was diagnosed to have Hirayama's disease(cervical flexion myelopathy). Via an anterior approach, he underwent a C 5 vertebrectomy followed by fixation of C 4-6 vertebral bodies using iliac bone and plate system. He recovered from surgery without any complications and has been well for the past 6 months with remarkable improvement of muscle strength. Application of cervical collar for 3 to 4 years has been generally advocated for the treatment of Hirayama's disease because progression of signs and symptoms is usually expected to cease within several years. However, some patients were reported not to response to conservative treatment for more than 5 years after their onsets. To these patients surgery seems to be beneficial, because it can give rise to permanent stable fixation with much shorter period of external cervical immobilization compared with cervical collar therapy, in which long-term application is frequently unbearable in many patients. In conclusion, the present case emphasizes the importance of surgical treatment in Hirayama's disease not only to improve neurological deficits but regain better quality of life.

H-, K-, and N-ras gene mutation in atypical fibroxanthoma and malignant fibrous histiocytoma

Atypical fibroxanthoma (AFX) which is histologically similar to malignant fibrous histiocytoma (MFH), occurs in the sun-exposed skin. The presence of mutations at codons 12 and 13 of the H- and K-ras genes and in exons 1 and 2, which include codons 12, 13, and 61, of the N-ras gene was studied in 8 cases of AFX and 8 cases of storiform-pleomorphic-type MFH using polymerase chain reaction (PCR)-restriction fragment length polymorphism and PCR-single-conformation polymorphism. Two of the 8 cases of MFH showed ras mutations in the H-ras gene at codon 12 (GGC-AGC) and in the K-ras gene at codon 13 (GGC-GAC). H- and K-ras gene mutations were not seen in any of the cases of AFX (0 of 8). N-ras gene mutation was not detected in either the AFX (0 of 8) or MFH (0 of 8) cases. In conclusion, although the number of cases in this study was small, H- and K-ras genes were present in some of the MFH cases and accordingly may play an important role in the pathogenesis of MFH. In addition, the finding that H-, K-, and N-ras gene mutations are not present in AFX may indicate why AFX has a more favorable behavior than MFH.

Metabolic activation of carcinogenic 1-nitropyrene by human cytochrome P450 1B1 in Salmonella typhimurium strain expressing an O-acetyltransferase in SOS/umu assay

Metabolic activation of 1-nitropyrene (1-NP) by human cytochrome P450 (P450) family 1 enzymes co-expressed with NADPH-cytochrome P450 reductase (NPR) in Escherichia coli membranes was investigated. 1-NP induced umu gene expression in Salmonella typhimurium TA1535/pSK1002 in the absence of any P450 system, but the activities were influenced by the levels of bacterial O-acetyltransferase (OAT) and nitroreductase. Metabolic activation of 1-NP by human P450 1B1/NPR membranes was observed and was influenced by the levels of OAT levels in tester strains. Metabolic activation of 1-NP (0.3microM) by P450 1B1 was 750 umu units/min/nmol P450 1B1 in an OAT-overexpressing strain NM2009. The metabolic activation of 1-NP (3-30microM) was similar (approximately 300 umu units/min/nmol P450 1B1) using TA1535/pSK1002 or OAT-deficient strain NM2000. P450 1B1 had the highest catalytic activities among P450 family 1 enzymes for the activation of 1-aminopyrene (1-AP) in the OAT-overexpressing strain NM2009, suggesting nitrenium ion formation via N-hydroxylation/O-acetylation. High-performance liquid chromatography (HPLC) analyses revealed the formation of 1-nitropyrene-6-ol and also 1-nitropyrene-3-ol, 1-nitropyrene-8-ol, and trans-4,5-dihydroxy-4,5-diol-1-nitropyrene from 1-NP (10microM), catalyzed by P450 1B1. These results indicate that 1-NP can be activated by human P450 1B1 to a genotoxic agent by nitroreduction/O-acetylation at low substrate concentrations and probably by epoxidation (independent of OAT) at high concentrations.

Denaturation and aggregation of hen egg lysozyme in aqueous ethanol solution studied by dynamic light scattering

We applied dynamic light scattering technique on the model system of hen egg lysozyme in salt-free aqueous ethanol solution to study the mechanism of denaturation and aggregation of protein. At low ethanol concentration [0-63% (v/v)], the fast relaxation mode was observed, which was caused by lysozyme molecules in the solution interacting with each other with strong repulsive electrostatic force. At 45 and 63% (v/v) ethanol, the slow relaxation mode was also observed, which showed translational diffusive nature, similar to that observed in salt-free polyelectrolyte solution. At 72 or 81% (v/v) ethanol, the slow mode disappeared, leaving only the fast mode. However, the mutual diffusion coefficients obtained from the fast mode at 72 and 81% (v/v) ethanol decreased by about one order of magnitude compared with those from the fast mode at 0-63% (v/v). The reported alcohol-induced conformational transformation of lysozyme molecules at >60% (v/v) ethanol from their native structure to an alpha-helix-rich structure might cause such drastic decrease in the mutual diffusion coefficients. At the highest ethanol concentration of 90% (v/v), the slow mode reappeared, and its relaxation rate was decreasing with elapsed time, which is possibly due to the growth of aggregates of lysozyme molecules. X-ray diffraction results suggested that the intermolecular beta-sheet formation caused the aggregation. Thus, our results indicated that the change in molecular structure of lysozyme closely relates to the diffusion of molecules and their aggregation.

Fluorescence polarization: analysis of carbohydrate-protein interaction

Fluorescence polarization has been widely used for the studies on the molecular motion in solution and has been applied to immunoassays for proteins, therapeutic drug monitoring in clinical pharmacy, and assays for environmentally toxic compounds. Because fluorescence polarization is most readily applicable to the kinetic analysis of the binding reaction between a substance having small molecular mass and a receptor molecule, this method is easily applied to the analysis of carbohydrate-lectin binding. In this tutorial Thematic Review, we briefly introduce the principles of fluorescence polarization and some applications of fluorescence polarization technique to glycobiology.

Characterization of receptors of insect cytokine, growth-blocking peptide, in human keratinocyte and insect Sf9 cells

Insect cytokine, growth-blocking peptide (GBP), enhances cell proliferation of human keratinocyte cells with a potency almost equivalent to that of human epidermal growth factor (EGF). GBP consists of 25 amino acid residues containing a core region that shows a striking similarity to the C-terminal beta-loop domain of EGF and disordered N and C termini. The present study demonstrates that, although GBP lacks the N-terminal half-portion of EGF molecule, at least five amino acids of the disordered N-terminal six-amino acid region are indispensable for affecting the cell growth activity of GBP. Upon stimulating mitogenesis in keratinocyte cells, GBP directly binds and activates their EGF receptors. GBP also effects proliferative activity on insect Sf9 cells through the binding and activation of the specific receptor, which consists of a heterodimeric complex: a binding subunit (60 kDa) and a tyrosine phosphorylation subunit (58 kDa). These results indicate that GBP enhances cell proliferation of human keratinocyte and insect Sf9 cells through the activation of EGF and GBP receptors, respectively.

Resin bonding to Er: YAG laser-irradiated dentin: combined effects of pre-treatments with citric acid and glutaraldehyde

The purpose of this study was to evaluate the combined effects of citric acid and glutaraldehyde (GA) on the resin bonding to Er: YAG laser-irradiated dentin. Bovine dentin was prepared with 180- to 600-grit SiC paper and then uniformly irradiated with an Er: YAG laser (laser-irradiated group) or immersed in water at 60 degrees C for 15 min (heated group). The samples were then acid-conditioned with 10% citric acid (10-0) or 10% citric acid/3% ferric chloride (10-3) for 15 s and treated with GA for 10 min before bonding to an acrylic rod with 4-META/MMA-TBB resin. These samples were trimmed to prepare miniaturized dumbbell-shaped specimens. After storage in water at 37C for 1 d, the tensile bond strength was measured, and the fractured surface was evaluated using a scanning electron microscope (SEM). In the laser-irradiated and heated groups, the 10-3+GA-treated specimen had higher bond strength than that of 10-0+GA. On the other hand, the tensile bond strength of 10-3 +GA in the non-irradiated group was lower that that of 10-0+GA. In conclusion, the combination of 10-3 and GA for bonding with 4-META/MMA-TBB resin was the most effective for Er: YAG laser-irradiated dentin and heated dentin, but it was not effective for the non-irradiated dentin.

Anomalous migration of hyaluronic acid oligomers in capillary electrophoresis: correlation to susceptibility to hyaluronidase

During high-resolution capillary electrophoresis analysis in an electrolyte solution containing a neutral polymer, small oligomers of regularly arranged acidic polysaccharides such as hyaluronic acid and N-acetylneuraminic acid polymers showed reversal of the migration order. This anomalous migration was well correlated with their reported biological activity. In the present study, we analyzed hyaluronidase action on the purified hyaluronic acid oligomers using capillary electrophoresis and found that hydrolytic and transglycosylation actions by hyaluronidase were dependent on the molecular sizes of hyaluronic acid oligomers, and well correlated to their migration profiles. Furthermore, fluorescent polarization technique was employed for understanding the relationship between molecular size of hyaluronic acid oligomers and their electromigrations.

Lactone formation of N-acetylneuraminic acid oligomers and polymers as examined by capillary electrophoresis

We examined lactone-formation reaction of oligomers and polymers of N-acetylneuraminic acid in diluted hydrochloric acid solution and found that the time course of the lactonization reaction was easily traced by capillary electrophoresis. The reaction proceeded more rapidly with increasing the molecular mass of oligomers because the conformation of inner units became rigid and more favorable for the formation of lactone linkage. Present results obtained using capillary electrophoresis will be useful in understanding of physical and chemical properties of oligo/polysialic acids.

beta-catenin nuclear expression correlates with cyclin D1 overexpression in sporadic desmoid tumours

The immunohistochemical expression of beta-catenin, cyclin D1, Ki-67 and PCNA was Examined in 38 cases of sporadic extra-abdominal or abdominal-wall desmoid tumours without familial adenomatous polyposis (FAP), to evaluate the hypothesis that the accumulated beta-catenin within the nuclei could affect the regulation of the cyclin D1 gene. There was a statistically significant correlation between beta-catenin accumulation and cyclin D1 overexpression (p=0.029). Each group with beta-catenin accumulation or cyclin D1 overexpression showed a higher PCNA-LI than those without, the difference being statistically significant (p=0.007, p=0.004, respectively). Differential PCR was also performed to detect amplification of the cyclin D1 gene and mutational analysis was undertaken for exon 3 of the beta-catenin gene. Amplification of the cyclin D1 gene was observed in 13 out of 22 cases (59.1%). There were nine-point mutations in 7 out of 18 cases (38.9%). The distribution of beta-catenin mutation fell within a wide range, from codon 21 to codon 67. In conclusion, beta-catenin nuclear expression correlated with cyclin D1 overexpression in sporadic desmoid tumours, which could be an in vivo model system for the APC-beta-catenin-Tcf pathway. In addition, beta-catenin mutations in desmoid tumours occurred at an unusually wide range of sites within the gene.

Seasonal distribution of enteropathogens detected from diarrheal stool and water samples collected in Kathmandu, Nepal

A total of 334 diarrheal fecal samples (from 210 males and 124 females) collected in Kathmandu, Nepal, were studied for various kinds of enteropathogens. Overall, 33% (111/334) fecal samples were positive for one or more enteropathogens. There was no difference in detection rates between males and females. Enteropathogen detection rates in summer, winter, spring, and autumn were 61% (40/66), 52% (45/87), 31% (25/81), and 25% (25/100), respectively. Altogether eight species of bacteria, three genera of viruses, and five species of protozoan parasites were detected with considerable seasonal variations. Among the bacterial isolates, enteropathogenic Escherichia coli topped the list followed by Vibrio sp. Only one sample had Shigella (S. sonnei). Rotavirus type A was the most frequently detected among the enteric viruses, followed by human enterovirus and human adenovirus, respectively. Among the enteric protozoan parasites, Giardia intestinalis was the most frequently detected followed by Cryptosporidium parvum. Detection of bacterial and protozoan pathogens showed a slightly high tendency in the summer season compared with that in the other seasons (p>0.05), whereas the detection of viruses was significantly high in the winter season (p<0.05). Of the total 57 water samples, 43 (75%) showed one or more bacterial species out of which 51% (22/43) were E. coli. Among the E. coli isolates, 68% were EPEC. Enterohemorrhagic E. coli (O157) was not detected.

The accumulation of angiostatin-like fragments in human prostate carcinoma

PURPOSE

Angiostatin, a potent inhibitor of angiogenesis and, hence, the growth of tumor cell metastasis, is generated by a proteolytic enzyme from plasminogen. However, its localization and specific enzymes have yet to be ascertained in human tissue.

EXPERIMENTAL DESIGN

To elucidate the generation and the localization of angiostatin in prostate carcinoma, we examined angiostatin generation in a panel of human prostate cancer cell lines and performed immunohistochemistry with the antibodies to angiostatin and prostate-specific antigen (PSA), a potent proteolytic enzyme of angiostatin in 55 cases of prostate carcinoma.

RESULTS

We demonstrated that the lysates of human prostate carcinoma cell lines could generate angiostatin-like fragments from purified human plasminogen but could not generate angiostatin in the absence of exogenous plasminogen. The fragmented proteins were reacted with the monoclonal antibody specific for plasminogen lysine-binding site 1 (LBS-1). Immunohistochemically, the intracytoplasmic immunostaining of LBS-1 was positive in 87.3% (48 of 55) of prostate carcinoma cases, and the immunostaining of miniplasminogen was negative in all cases. There was a significant relationship between the positive immunostaining of LBS-1 and Gleason score (P = 0.0007). The intracytoplasmic immunostaining of PSA was positive in 37.0% (20 of 54) of prostate carcinoma cases, but there was no significant relationship between the expression of PSA and Gleason score, or between the positive immunostaining of LBS-1 and PSA.

CONCLUSIONS

These findings suggest that angiostatin is generated by prostate carcinoma cells and is accumulated within the cytoplasm. In addition, the generation of angiostatin-like fragments was correlated with tumor grade; however, PSA may not be the only enzyme for angiostatin generation in human prostate carcinoma.

Subcellular distribution of cytokeratin and vimentin in malignant rhabdoid tumor: three-dimensional imaging with confocal laser scanning microscopy and double immunofluorescence

Malignant rhabdoid tumor (MRT) is a highly aggressive neoplasm that mostly occurs in childhood, characterized histologically by rhabdoid cells as shown by eosinophilic intracytoplasmic inclusions. Although it is known that rhabdoid cells co-express cytokeratin (CK) and vimentin, the distribution patterns of these two kinds of intermediate filaments and structural relationship between them are still not known. We investigated the subcellular distribution of CKs 8 and 18 and vimentin in MRT cell lines (Tm87-16, STM91-01, TTC549, and TC289) using confocal laser scanning microscopy and double immunofluorescence, in addition to ultrastructural examination. Vimentin was diffusely expressed in the cytoplasm of MRT cells, focally forming a filamentous network. In contrast, CKs 8 and 18 were partially expressed in the cytoplasm of MRT cells, forming globules or a few vague agglomerates. Three-dimensional images in TC289 cells revealed distinct distribution patterns of cytokeratin and vimentin, showing agglomerates of cytokeratins within the vimentin filament network. We conclude that these globules and agglomerates of CKs 8 and 18 correspond with the characteristic ultrastructural finding, showing cytoplasmic bundles of intermediate filaments concentrated in whorled arrays.

Metabolic activation of polycyclic aromatic hydrocarbons and other procarcinogens by cytochromes P450 1A1 and P450 1B1 allelic variants and other human cytochromes P450 in Salmonella typhimurium NM2009

A variety of polycyclic aromatic hydrocarbons and their dihydrodiol derivatives, arylamines, heterocyclic amines, and nitroarenes, were incubated with cDNA-based recombinant (Escherichia coli or Trichoplusia ni) systems expressing different forms of human cytochrome P450 (P450 or CYP) and NADPH-P450 reductase using Salmonella typhimurium tester strain NM2009, and the resultant DNA damage caused by the reactive metabolites was detected by measuring expression of umu gene in the cells. Recombinant (bacterial) CYP1A1 was slightly more active than any of four CYP1B1 allelic variants, CYP1B1*1, CYP1B1*2, CYP1B1*3, and CYP1B1*6, in catalyzing activation of chrysene-1,2-diol, benz[a]anthracene-trans-1,2-, 3,4-, 5,6-, and 8,9-diol, fluoranthene-2,3-diol, dibenzo[a,l]pyrene, benzo[c]phenanthrene, and dibenz[a,h]anthracene and several arylamines and heterocyclic amines, whereas CYP1A1 and CYP1B1 enzymes had essentially similar catalytic specificities toward other procarcinogens, such as (+)-, (-)-, and (+/-)-benzo[a]pyrene-7,8-diol, 5-methylchrysene-1,2-diol, 7,12-dimethylbenz[a]anthracene-3,4-diol, dibenzo[a,l]pyrene-11,12-diol, benzo[b]fluoranthene-9,10-diol, benzo[c]chrysene, 5,6-dimethylchrysene-1,2-diol, benzo[c]phenanthrene-3,4-diol, 7,12-dimethylbenz[a]anthracene, benzo[a]pyrene, 5-methylchrysene, and benz[a]anthracene. We also determined activation of these procarcinogens by recombinant (T. ni) human P450 enzymes in S. typhimurium NM2009. There were good correlations between activities of procarcinogen activation by CYP1A1 preparations expressed in E. coli and T. ni cells, although basal activities with three lots of CYP1B1 in T. ni cells were very high without substrates and NADPH in our assay system. Using 14 forms of human P450s (but not CYP1B1) (in T. ni cells), we found that CYP1A2, 2C9, 3A4, and 2C19 catalyzed activation of several of polycyclic aromatic hydrocarbons at much slower rates than those catalyzed by CYP1A1 and that other enzymes, including CYP2A6, 2B6, 2C8, 2C18, 2D6, 2E1, 3A5, 3A7, and 4A11, were almost inactive in the activation of polycyclic aromatic hydrocarbons examined here.

Metabolism of methadone and levo-alpha-acetylmethadol (LAAM) by human intestinal cytochrome P450 3A4 (CYP3A4): potential contribution of intestinal metabolism to presystemic clearance and bioactivation

Methadone and levo-alpha-acetylmethadol (LAAM) are opioid agonists used for analgesia and preventing opiate withdrawal. Methadone is sequentially N-demethylated to the inactive metabolites 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyraline (EMDP). LAAM is essentially a prodrug that undergoes bioactivation via sequential N-demethylation to levo-alpha-acetyl-N-normethadol (nor-LAAM) and levo-alpha-acetyl-N,N-dinormethadol (dinor-LAAM). Methadone and LAAM are metabolized by CYP3A4 in human liver. Since they are administered orally, and CYP3A4 is expressed in human intestine, we tested the hypotheses that human intestine can metabolize methadone and LAAM, and evaluated the participation of CYP3A4. Intestinal microsomal methadone N-demethylation exhibited hyperbolic noncooperative kinetics and biphasic Eadie-Hofstee plots. Using a dual-enzyme Michaelis-Menten model, K(m) values were 11 and 1200 microM for EDDP and 23 and 930 microM for EMDP formation, respectively. CYP3A4 inhibitors (troleandomycin and ketoconazole) inhibited EDDP and EMDP formation by >70%. Methadone N-demethylation by CYP3A4 showed biphasic Eadie-Hofstee plots without evidence of positive cooperativity; K(m) values were 10 and 1100 microM for EDDP and 20 and 1000 microM for EMDP formation. Intestinal microsomal LAAM and nor-LAAM N-demethylation also exhibited hyperbolic kinetics and biphasic Eadie-Hofstee plots. K(m) values were 21 and 980 microM for nor-LAAM from LAAM and 18 and 1200 microM for dinor-LAAM from nor-LAAM. Troleandomycin and ketoconazole inhibited N-demethylation by >70%. LAAM and nor-LAAM metabolism by CYP3A4 showed biphasic Eadie-Hofstee plots without evidence of positive cooperativity; K(m) values were 8 and 1300 microM, 6 and 950 microM, respectively. Predicted in vivo intestinal extraction of methadone and LAAM is 21 and 33%, respectively. We conclude that methadone, LAAM, and nor-LAAM are metabolized by human intestinal microsomes; CYP3A4 is the predominant cytochrome P450 isoform; CYP3A4-catalyzed methadone, LAAM, and nor-LAAM metabolism is characterized by noncooperative, multisite kinetics; and intestinal metabolism may contribute to presystemic methadone inactivation and LAAM bioactivation.

Gender variations in the prevalence of parasitic infections and the level of awareness in adolescents in rural Nepal

The study was conducted in rural school adolescent children to investigate the awareness and its association in parasitic infections in boys and girls. Of the 182 children examined 119 (65.3%) were male and 63 (34.6%) were female, age ranged 12-20 years with median age 15 years. Out of 182 stool samples examined 73 (40%) were found to be positive for parasites in which two or more parasites were found in 10 stool samples. Giardia lamblia 33 (18.1%) was the predominant parasite followed by hook worm 27 (14.8%) Entamoeba histolytica 13 (7.1%), Ascaris lumbricoides 05 (2.7%), Hyminolepis nana 02 (2.2%) and Trichuris trichiuria 01 (0.5%). Thirty-one (49.2%) in 63 females and 40 (33.6%) of the 119 males were positive for parasitic infections. The prevalence of worm infection was significantly higher in female children than male (p < or = 0.05). In contrast to the high parasitic prevalence rate in females they possessed significantly higher levels of awareness about parasitic infections. Out of 119 males 99 (83.2%) and 61 (96.8%) of the 63 females (p < or = 0.05) knew that worms suck food from host body. Similarly, 62.2% of males and 96.85 of females (p < or = 0.05) knew that parasites suck blood from human body. More study should be carried out to find out the gender difference in parasitic infection and level of exposure to risk factors.

Malignant peripheral nerve sheath tumours: high Ki67 labelling index is the significant prognostic indicator

AIMS

We investigated p53, Ki67, MDM2, and p21WAF1/CIP1 in order to evaluate its relationship with prognosis in malignant peripheral nerve sheath tumours (MPNST).

METHODS AND RESULTS

In 49 cases of MPNSTs, the immunohistochemical studies of Ki67, p53, MDM2, p21WAF1/CIP1 and polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) with direct sequencing of p53 were performed with the formalin-fixed paraffin-embedded tissue. In 43 cases with survival data available, an evaluation of the prognostic significance of clinicopathological factors was also carried out. A high Ki67 labelling index (LI) (>25%) was correlated with a reduced survival rate in the 43 cases of MPNST (P=0.0106, log-rank test). Furthermore, there was a significant correlation between the Ki67 LI and the immunohistochemical expression of p53 or MDM2. In 17 MPNST cases, PCR amplification of exons 5 through 8 of the p53 gene was successful. One case showed a base change of codon 240 (AGT-->AGC), but translated amino acid (Ser) remained unchanged. Multivariate Cox analysis of our series showed that the association of von Recklinghausen's disease, tumour depth, and the presence of rhabdomyoblasts (malignant triton tumour) each had an independent negative impact on overall survival.

CONCLUSION

High Ki67 LI (>25%) was of significant prognostic value in MPNST.

Pleomorphic leiomyosarcoma: clinicopathologic and immunohistochemical study with special emphasis on its distinction from ordinary leiomyosarcoma and malignant fibrous histiocytoma

Pleomorphic leiomyosarcoma (PLMS) was recently described as a morphologic variant of leiomyosarcoma; however, its diagnostic criteria, as shown by morphologic features and biologic behavior, remain controversial. We describe 28 cases of pleomorphic sarcoma with pleomorphic areas in more than two thirds of the tumor and an ordinary leiomyosarcomatous fascicular area covering less than one third as PLMS. PLMS comprised 8.6% of all the leiomyosarcomas (322 cases) registered in our institute. Patients ranged in age from 31 to 89 years (average, 57.9 years). Seventeen patients (60.7%) were male and 11 were female. Tumor location was as follows: the extremities in 17 cases, the retroperitoneum or abdominal cavity in 7 cases, the chest/abdominal wall in 3 cases, and the scalp in 1 case. Histologically, all cases showed at least small foci of fascicles consisting of smooth muscle tumor cells, in addition to pleomorphic areas mimicking storiform-pleomorphic malignant fibrous histiocytoma. The border between pleomorphic and leiomyosarcomatous fascicular areas was sharp in 3 cases, gradual in 2 cases, and blending in 23 cases. Sixteen cases (57.1%) showed a typical storiform pattern, 6 cases revealed extensive stromal hyalinization, 6 cases showed a chronic inflammatory infiltrate, 2 cases had the foci of foamy xanthomatous cells, and 7 cases contained myxoid malignant fibrous histiocytoma-like areas covering less than 50% of the tumor. The tumors had a tendency to be of a morphologically higher grade (10 tumors were French Federation of Cancer Centers grade 2, 18 were grade 3). Five of 28 cases (18%) showed rhabdoid features. Immunohistochemically, all of the 28 tumors examined showed a positive reactivity for at least one smooth muscle marker (desmin, muscle-specific actin, and alpha-smooth muscle actin) in the leiomyosarcomatous fascicular areas. In the pleomorphic areas the expression of smooth muscle markers (desmin 10 of 28, muscle-specific actin 13 of 28, and alpha-smooth muscle actin 14 of 28) was significantly reduced, compared with that in leiomyosarcomatous fascicular area (desmin 18 of 28, muscle-specific actin 26 of 28, and alpha-smooth muscle actin 24 of 28). No significant difference was observed between the MIB-1 labeling index in the leiomyosarcomatous fascicular areas (26.10 on average) and that in the pleomorphic areas (26.17 on average). However, the MIB-1 labeling index in PLMS was significantly higher than that in ordinary leiomyosarcoma (n = 20, 12.86 on average) or storiform-pleomorphic malignant fibrous histiocytoma (n = 16, 16.63 on average). In 23 patients follow-up data were available with a duration of 1-239 months. Eleven patients developed metastases, and lung accounted for the most common site of metastasis (9 cases). Fifteen of 23 patients (65.2%) died of disease. Our results indicate that PLMS should be differentiated from ordinary leiomyosarcoma because of its high proliferative activities and rather aggressive biologic behavior.

Malignant peripheral nerve sheath tumour arising within neurofibroma. An immunohistochemical analysis in the comparison between benign and malignant components

AIMS

To compare the expression of immunohistochemical variables between benign and malignant components of malignant peripheral nerve sheath tumour (MPNST) arising within neurofibroma.

METHODS

Eight cases of MPNST arising within a neurofibroma, associated with neurofibromatosis type 1 (NF1), were studied. The areas of MPNST and neurofibroma were compared immunohistochemically with regard to the expression of proliferative activity (MIB-1), growth factors, p53, bcl-2, neural cell adhesion molecule (N-CAM), and CD34.

RESULTS

The expression of transforming growth factor beta 1 (TGF-beta 1), TGF-beta receptor type II, hepatocyte growth factor alpha (HGF-alpha), c-met, p53, and N-CAM was higher in the areas of MPNST than in the neurofibromatous areas in four, five, five, eight, five, and three of the eight cases, respectively. CD34 expression was lower in the areas of MPNST than in the neurofibroma areas in three of the eight cases.

CONCLUSIONS

On the basis of these findings, TGF-beta 1, HGF-alpha, and p53 might be involved in the malignant transformation of neurofibroma to MPNST.

Mutations of the p53 gene in malignant rhabdoid tumors of soft tissue and the kidney: immunohistochemical and DNA direct sequencing analysis

Malignant rhabdoid tumor (MRT) is characterized by the presence of intracytoplasmic eosinophilic inclusions composed of whorls of intermediate filaments. This tumor was originally described as an entity of the abortive type of Wilms' tumor in childhood. Recently, it has been proved that these rhabdoid cells can be observed in various types of malignant tumors, including soft tissue sarcoma or carcinoma. To investigate the oncogenesis of this tumor, we examined the p53 gene alteration by means of immunohistochemical analysis and DNA direct sequencing in three cases of malignant rhabdoid tumor (MRT) of the soft tissue and three cases of MRT of the kidney. All the cases of MRT of the soft tissue and two of the cases of MRT of the kidney showed immunopositivity for p53 protein. Among them, one of the cases of MRT of the soft tissue and two of the cases of MRT of the kidney showed missense mutations of the p53 gene. These results strongly suggest that p53 gene alterations may have an important role to play in the aggressive biological behavior and poor prognosis of this tumor.

Mutagenicity of TCDD in Big Blue transgenic rats

The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a significant environmental contaminant resulting from such industrial processes as pulp and paper production. TCDD is a suspected human carcinogen and its ability to induce cancer in laboratory rodents is well documented. Its mechanism of tumor initiation, however, is not well understood and in vitro mutagenicity studies have yielded inconsistent results. In this study, Big Blue lacI transgenic rats were used to assess the mutagenicity of TCDD in both male and female animals. After 6 weeks of exposure to 2 microg/kg TCDD neither an increase in mutation frequency nor any change in mutation spectrum was observed in either male or female animals.

Focal segmental glomerulosclerosis associated with acromegaly

Experimental studies in rats have demonstrated an association between focal segmental glomerulosclerosis (FSGS) and growth hormone, but patients with FSGS complicating acromegaly are very rare. In this report we present a case of FSGS associated with acromegaly. With a long history of soft tissue swelling of hands and feet, elevated plasma growth hormone levels and other biochemical abnormalities, a 53-year old male had suffered from acromegaly for over 15 years. He had moderate proteinuria for 6 years, but never evidenced nephrotic syndrome. A renal biopsy specimen revealed FSGS and glomerular hypertrophy. Trans-sphenoidal surgical removal of the pituitary adenoma resulted in the normalization of elevated growth hormone and insulin-like growth factor I levels, but proteinuria continued. This case suggests that the overproduction of growth hormone may participate, at least in part, in the development of human FSGS. It is possible that once FSGS is present in an acromegalic patient, cessation of GH overproduction may not be enough to reverse it.

Expression of intercellular adhesion molecules in epithelioid sarcoma and malignant rhabdoid tumor

We clinicopathologically evaluated 31 cases of epithelioid sarcoma (ES; 25 'classical' type and six 'proximal variant' type) and six cases of malignant rhabdoid tumor (MRT; three extrarenal and three renal). We also did immunohistochemical studies on 12 classical and three proximal variant cases of ES, and six cases of MRT, to clarify the differences in biological behavior in these tumors. E-cadherin, beta-catenin and CD34 expression was evaluated. We also carried out mutational analysis of exon 3 of the beta-catenin gene by polymerase chain reaction-single-strand conformation polymorphism analysis. In ES, the 5- and 10-year survival rates were 71.1 and 55.3%, respectively. A high mitotic rate (>15/10 high-power fields) was significantly correlated with a poor overall survival rate in ES (P = 0.0248). E-cadherin expression was observed in nine cases (69.2%) of ES and in four cases (66.7%) of MRT. Most of these tumors showed aberrant E-cadherin expression. Seven cases (46.7%) of ES were positive for CD34, although none of the cases of MRT were CD34 positive. Eleven cases (73.3%) of ES were positive for beta-catenin, which was localized to the cellular membrane, whereas all of the cases of MRT were beta-catenin negative. Mutational analysis for the beta-catenin gene was done in nine cases of ES and six cases of MRT, however, genetic alteration was not found. From our results, we conclude that beta-catenin membranous expression could be a useful marker for distinguishing ES, including the proximal variant, from MRT.

Influence of surface modifications to titanium on antibacterial activity in vitro

The antibacterial effect of surface modifications to titanium on Porphyromonas gingivalis ATCC 33277 and Actinobacillus actinomycetemcomitans ATCC 43718 was evaluated. Surface modifications were performed with dry processes including ion implantation (Ca+, N+, F+), oxidation (anode oxidation, titania spraying), ion plating (TiN, alumina), and ion beam mixing (Ag, Sn, Zn, Pt) with Ar+ on polished pure titanium plates. F+-implanted specimens significantly inhibited the growth of both P. gingivalis and A. actinomycetemcomitans than the polished titanium. The other surface-modified specimens did not exhibit effective antibacterial activity against both bacteria. No release of the fluorine ion was detected from F-implanted specimens under dissolution testing. This result and the characterization of the F+-implanted surfaces suggested that the possible antibacterial mechanism of the F+-implanted specimen was caused by the formation of a metal fluoride complex on the surfaces. In addition, F+-implanted surfaces did not inhibit the proliferation of fibroblast L929-cells. These findings indicate that surface modification by means of a dry process is useful in providing antibacterial activity of oral bacteria to titanium implants exposed to the oral cavity.

Glomerular CD8+ cells predict progression of childhood IgA nephropathy

The aim of this study was to evaluate whether the infiltrating T-lymphocyte can be a predictor in the disease progression of IgA nephropathy (IgAN). Twenty children with IgAN, followed for more than 5 years, were divided into progressive (n=5) and non-progressive groups (n=15). We assessed glomerular and interstitial infiltration of T-lymphocytes (CD4+ and CD8+ cells) and expression of alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-beta (TGF-beta) using an indirect immunofluorescence method on the renal biopsies. We analyzed their relationship to the degree of proteinuria, histological changes, and prognosis. The number of CD8+ cells in glomeruli and in interstitium was higher in the progressive group than in the non-progressive group. The glomerular alpha-SMA staining was more intensive in the progressive group than in the non-progressive group. Urinary protein and the degree of histological changes were also higher in the progressive group than in the non-progressive group. Among these markers, the number of glomerular CD8+ cells was the most apparent difference between the two groups. In conclusion, these results indicate that the number of glomerular CD8+ cells is the most sensitive predictor of disease progression in childhood IgAN.

The contribution of UDP-glucuronosyltransferase 1A9 on CYP1A2-mediated genotoxicity by aromatic and heterocyclic amines

The importance of environmental and dietary arylamines, and heterocyclic amines in the etiology of human cancer is of growing interest. These pre-carcinogens are known to undergo bioactivation by cytochrome P450 (CYP)-directed oxidation, which then become substrates for the UDP-glucuronosyltransferases (UGTs). Thus, glucuronidation may contribute to the elimination of CYP-mediated reactive intermediate metabolites, preventing a toxic event. In this study, human UGTs were analyzed for their ability to modulate the mutagenic actions of N-hydroxy-arylamines formed by CYP1A2. Studies with recombinant human UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT1A10, UGT2B4, UGT2B7 and UGT2B15 expressed in heterologous cell culture confirmed that UGT1A9 glucuronidated the mutagenic arylamines N-hydroxy-2-acetylaminofluorene (N-hydroxy-2AAF) and 2-hydroxyamino-1-methyl-6-phenylimidazo(4,5-b)pyridine (N-hydroxy-PhIP). To examine the mutagenic potential of these agents, a genotoxicity assay was employed using Salmonella typhimurium NM2009, a bacterial strain expressing the umuC SOS response gene fused to a beta-galactosidase reporter lacZ gene. DNA modification results in the induction of the umuC gene and subsequent enhancement of beta-galactosidase activity. Both N-hydroxy-2AAF and N-hydroxy-PhIP stimulated a dose-dependent increase in bacterial beta-galactosidase activity. In addition, the procarcinogens 2AAF and PhIP were efficiently bioactivated to bacterial mutagens when incubated with Escherichia coli membranes expressing CYP1A2 and NADPH reductase. CYP1A2 generated 2AAF- and PhIP-mediated DNA damage, but only the action of N-hydroxy-2AAF was blocked by expressed UGT1A9. These results indicate that UGT1A9 can control the outcome of a genotoxic response. The results also indicate that while a potential toxicant such as N-hydroxy-PhIP can serve as substrate for glucuronidation, its biological actions can exceed the capacity of the detoxification pathway to prevent the mutagenic episode.

Influence of different acid conditioners on the tensile bond strength of 4-META/MMA-TBB resin to Er:YAG laser-irradiated bovine dentin

PURPOSE

This study evaluated the effect of acid conditioners on resin bonding to dentin following irradiation with an Er:YAG laser and investigated the characteristics of resin bonding to the laser-treated dentin.

MATERIALS AND METHODS

Extracted bovine teeth were cervically sectioned to expose a dentin surface. After polishing, the dentin was irradiated with an Er:YAG laser. Aqueous solutions of 10% citric acid (10-0) or 10% citric acid/3% ferric chloride (10-3) were then applied to the laser-treated surface as acid conditioners. After the acid treatment, a PMMA rod was bonded to the irradiated dentin using 4-META/MMA-TBB resin, and miniaturized dumbbell-shaped bonded specimens were prepared. These specimens were subjected to tensile testing, and fractured surfaces were observed with field-emission scanning electron microscopy (FE-SEM) to determine the mode of fracture. Additionally, the resin-dentin interfaces were observed under FE-SEM.

RESULTS

The tensile bond strength of acid-conditioned bonded specimens was lower than that of specimens not subjected to acid treatment (11.1 MPa) in the laser-irradiated group. No significant difference was observed between 10-0 and 10-3 treatments. 10-3 treatment yielded the highest bond strength (24.6 MPa) in the nonirradiated group, as opposed to only 7.7 MPa in the laser-treated group. Cohesive failure in the dentin was observed in almost all specimens in the irradiated group. Furthermore, a 10- to 30-micron-thick resin-penetrated layer was observed at the interface between the dentin and resin.

CONCLUSION

These results suggest that the effect of acid conditioners on resin bonding to dentin differs according to whether the dentin has been laser irradiated or not.

[A case of intrasellar meningioma mimicking pituitary adenoma]

The authors report a patient with a rare intrasellar meningioma mimicking pituitary adenoma. A 60-year-old man was admitted to our hospital for evaluation of general fatigue. He had no neurological deficit including visual function. Endocrinological tests revealed panhypopituitarism. The craniogram showed slight enlargement of the sella turcica with thinning of the dorsum sellae. CT scan and MR imaging demonstrated a homogeneously enhanced intrasellar mass with slight suprasellar extension. Partial removal of the mass was performed via the transsphenoidal approach because it was extremely firm and hemorrhagic. Histological diagnosis was transitional meningioma. The patient has been well for two years after surgery without tumor progression on MR imaging. It is mandatory to distinguish intrasellar meningioma from pituitary adenoma preoperatively because of marked difference in their treatment strategies. Despite recent advances in neurodiagnostic imaging, it may still be difficult to differentiate pituitary adenoma from intrasellar meningioma. When we re-evaluated the MR imaging, we recognized that the tumor had demonstrated specific findings, ruling out pituitary adenoma, namely bright and homogeneous enhancement, dense enhancement in the early phase on the dynamic MR study, and flow void signal within the mass. The authors emphasize that careful evaluations of MR imaging will allow the correct preoperative diagnosis in patients with intrasellar meningioma mimicking pituitary macroadenoma.

Capillary electrophoresis of sialic acid-containing glycoprotein. Effect of the heterogeneity of carbohydrate chains on glycoform separation using an alpha1-acid glycoprotein as a model

alpha1-Acid glycoprotein (AGP) showed multiple peaks on separation using capillary electrophoresis in a chemically modified capillary with dimethylpolysiloxane at slightly acidic conditions. We analyzed glycoforms of AGP species after separation by ion-exchange chromatography, Con A affinity chromatography, and Cu(II)-chelating affinity chromatography. The AGP species thus obtained were digested with N-glycosidase F, and the released carbohydrate chains were analyzed by high-performance liquid chromatography after labeling with 3-aminobenzoic acid. The results afforded basic information on the contribution of carbohydrate chains to the separation mechanism of glycoforms of AGP by capillary electrophoresis. In addition, we describe an easy method for AGP analysis in serum samples using the electrokinetic injection.

Immunoexpression of ultraviolet photoproducts and p53 mutation analysis in atypical fibroxanthoma and superficial malignant fibrous histiocytoma

p53 mutation is one of the major results of ultraviolet (UV) radiation. UV photoproducts of cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone (6-4) photoproducts (64PPs) also play an important role in skin cancer development. Atypical fibroxanthoma (AFX), which mimics malignant fibrous histiocytoma (MFH) histologically, occurs in the sun-exposed skin of the elderly, and therefore, an association with UV has long been suspected. Eighteen fibrohistiocytic skin lesions comprising AFX (n = 7), storiform-pleomorphic type MFH centered in the subcutis (superficial MFH; S-MFH; n = 4) and benign fibrous histiocytoma (BFH; n = 7) were used for immunohistochemical and molecular analysis. Eight cases of deep MFH (D-MFH) were also analyzed for UV photoproduct expression for the purposes of comparison. Immunohistochemically, the CPD scores of AFX (3.6 +/- 0.4) were significantly higher than those of S-MFH (1.3 +/- 0.8), D-MFH (0.8 +/- 0.5), or BHF (1.4 +/- 0.7); however, the 64PP scores were extremely low in all these tumors (AFX, 0.1 +/- 0.1; S-MFH, 0.0 +/- 0.0; D-MFH, 0.0 +/- 0.0; and BHF, 0.0 +/- 0.0). AFX, S-MFH, and BFH showed immunoexpression for p53 (2/7, 2/4, and 0/7), respectively. p53 mutations were detected in AFX (4/6; 67%) and S-MFH (1/4; 25%), but not in BFH (0/5; 0%) using polymerase chain reaction-single-strand conformation polymorphism, and all of the mutations in AFX were either C-T transitions or at dipyrimidine sites. In conclusion, AFX and S-MFH are both similar fibrohistocytic lesions; however, AFX has high immunoreactivity for CPDs compared with S-MFH, D-MFH, or BFH. These data suggest that CPDs may play an important role in the pathogenesis of AFX.

The protease-activated receptor-2 agonist induces gastric mucus secretion and mucosal cytoprotection

Protease-activated receptor-2 (PAR-2), a receptor activated by trypsin/tryptase, modulates smooth muscle tone and exocrine secretion in the salivary glands and pancreas. Given that PAR-2 is expressed throughout the gastrointestinal tract, we investigated effects of PAR-2 agonists on mucus secretion and gastric mucosal injury in the rat. PAR-2-activating peptides triggered secretion of mucus in the stomach, but not in the duodenum. This mucus secretion was abolished by pretreatment with capsaicin, which stimulates and ablates specific sensory neurons, but it was resistant to cyclo-oxygenase inhibition. In contrast, capsaicin treatment failed to block PAR-2-mediated secretion from the salivary glands. Intravenous calcitonin gene-related peptide (CGRP) and neurokinin A markedly elicited gastric mucus secretion, as did substance P to a lesser extent. Specific antagonists of the CGRP1 and NK2, but not the NK1, receptors inhibited PAR-2-mediated mucus secretion. Pretreatment with the PAR-2 agonist strongly prevented gastric injury caused by HCl-ethanol or indomethacin. Thus, PAR-2 activation triggers the cytoprotective secretion of gastric mucus by stimulating the release of CGRP and tachykinins from sensory neurons. In contrast, the PAR-2-mediated salivary exocrine secretion appears to be independent of capsaicin-sensitive sensory neurons.

Calcium- and vitamin D-regulated keratinocyte differentiation

Calcium and 1,25 dihydroxyvitamin D (1,25(OH)(2)D) regulate the differentiation of keratinocytes. We have examined the mechanisms by which such regulation takes place, focusing primarily on the events leading to cornified envelope (CE) formation, in particular the mechanisms by which calcium and 1,25(OH)(2)D regulate the induction of involucrin, a component of the CE, and transglutaminase, the enzyme cross-linking involucrin and other substrates to form the CE. Both extracellular calcium (Ca(o)) and 1,25(OH)(2)D raise intracellular free calcium (Ca(i)) as a necessary step toward stimulating differentiation. Cells lacking the calcium sensing receptor (CaR) or phospholipase C-gamma 1 (PLC-gamma 1) fail to respond to Ca(o) or 1,25(OH)(2)D with respect to differentiation. Residing in the promoter of involucrin is a region responsive to calcium and 1,25(OH)(2)D, the calcium response element (CaRE). The CaRE contains an AP-1 site, mutations of which result in loss of responsiveness to Ca(o) and 1,25(OH)(2)D, indicating a role for protein kinases C (PKC). PKC alpha is the major PKC isozyme involved at least for calcium-induced differentiation. Thus, the regulation of keratinocyte differentiation by calcium and 1,25(OH)(2)D involves a number of signaling pathways including PLC and PKC activation, leading to the induction of proteins required for the differentiation process.

Long-term follow-up study of sustained biochemical responders with interferon therapy

A proportion of chronic hepatitis C patients who were treated with interferon have a sustained normalization of transaminase levels after interferon therapy without hepatitis C virus (HCV)-RNA clearance. We determined their clinical characteristics and long-term outcome in relation to progression to liver cirrhosis (LC) and the development of hepatocellular carcinoma (HCC). A total of 250 patients with chronic hepatitis C who were treated with interferon were studied for 8 to 11 years' posttherapy. Sixty-seven patients (27%) were complete responders with clearance of HCV RNA. Twenty-six (10%) were biochemical responders who had sustained normal alanine transaminase (ALT) levels without viral clearance. The remaining patients were short-term responders (n = 70) and nonresponders (n = 87). Biochemical responders were older, had higher levels of pretreatment HCV RNA in serum than complete responders, and had less advanced liver histology than nonresponders. Histologic grading scores decreased significantly at the end of therapy, while the staging scores did not change significantly. The annual incidence of cirrhosis was 0% in biochemical and complete responders, which was significantly lower than nonresponders and the controls (P = .0001). The annual incidence of HCC was 0.37% in complete responders and 0.50% in biochemical responders, which was significantly lower than nonresponders (P = .0001 for both). Our findings suggest that biochemical responders had high pretreatment viral levels with less advanced liver histology, and their long-term outcome appeared to be good irrespective of the persistence of the virus.

Metabolic activation of heterocyclic amines and other procarcinogens in Salmonella typhimurium umu tester strains expressing human cytochrome P4501A1, 1A2, 1B1, 2C9, 2D6, 2E1, and 3A4 and human NADPH-P450 reductase and bacterial O-acetyltransferase

We investigated roles of different forms of cytochrome P450 (P450 or CYP) in the metabolic activation of heterocyclic amines (HCAs) and other procarcinogens to genotoxic metabolite(s) in the newly developed umu tester strains Salmonella typhimurium (S. typhimurium) OY1002/1A1, OY1002/1A2, OY1002/1B1, OY1002/2C9, OY1002/2D6, OY1002/2E1 and OY1002/3A4, which express respective human P450 enzymes and NADPH-cytochrome P450 reductase (reductase) and bacterial O-acetyltransferase (O-AT). These strains were established by introducing two plasmids into S. typhimurium TA1535, one carrying both P450 and the reductase cDNA in a bicistronic construct under control of an IPTG-inducible double tac promoter and the other, pOA102, carrying O-AT and umuC"lacZ fusion genes. Expression levels of CYP were found to range between 35 to 550 nmol/l cell culture in the strains tested. O-AT activities in different strains ranged from 52 to 125 nmol isoniazid acetylated/min/mg protein. All HCAs tested, and 2-aminoanthracene and 2-aminofluorene exhibited high genotoxicity in the OY1002/1A2 strain, and genotoxicity of 2-amino-3-methylimidazo [4,5-f]quinoline was detected in both the OY1002/1A1 and OY1002/1A2 strains. 3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]-indole and 3-amino-1-methyl-5H-pyrido[4,3-b]-indole were activated in the OY1002/1A1, OY1002/1B1, OY1002/1A2, and OY1002/3A4 strains. Aflatoxin B(1) exhibited genotoxicity in the OY1002/1A2, OY1002/1A1, and OY1002/3A4 strains. beta-Naphthylamine and benzo[a]pyrene did not exhibit genotoxicity in any of the strains. These results suggest that CYP1A2 is the major cytochrome P450 enzyme involved in bioactivation of HCAs.

Defective development of secretory neurones in the hypothalamus of Arnt2-knockout mice

BACKGROUND

Within the basic region-helix-loop-helix (bHLH)-PAS family of transcription factors, Arnt and Arnt2 play unique roles; these two factors not only heterodimerize with themselves, but also with other members of this family and they act as transcription regulators which bind to specific DNA elements. Whereas Arnt is broadly expressed in various tissues, the expression of Arnt2 is known to be limited to the neural tissues.

RESULTS

To elucidate the function of Arnt2 in detail, we cloned the mouse Arnt2 gene and its gene structure was determined. We subsequently generated germ line Arnt2 mutant mice by gene targeting technology. Heterozygous Arnt2 mice were viable, but homozygous Arnt2 gene knockout mice died shortly after birth. Histological and immunological analyses revealed that the supraoptic nuclei (SON) and the paraventricular nuclei (PVN) are hypocellular. Moreover, secretory neurones identified by the expression of neurosecretory hormone such as arginine vasopressin, oxytocin, corticotrophin-releasing hormone and somatostatin are completely absent in SON and PVN in the mutant Arnt2 mice. Consistent with these observations, prospective SON and PVN neurones which express Brn2 appeared around E13.5 in the mantle zone, but no neurones which expressed the neurosecretory hormones were found in the SON and PVN regions.

CONCLUSIONS

These data show that the transcription factor Arnt2 controls the development of the secretory neurones at the later or final stages of differentiation rather than at the beginning stage. Strikingly similar observations have been reported with the Sim1 deficient mice. Taken together, our results demonstrate that Arnt2 is an indispensable transcription factor for the development of the hypothalamus, and suggest that Arnt2 is an obligatory partner molecule of Sim1 in the developmental process of the neuroendocrinological cell lineages.

Immunoreactivity of p53, mdm2, and p21WAF1 in dedifferentiated liposarcoma: special emphasis on the distinct immunophenotype of the well-differentiated component

Alteration of the p53/mdm2 pathway has been reported in the well-differentiated liposarcoma (WDLS)/dedifferentiated liposarcoma (DDLS) group. We investigated the immunoreactivity of p53, mdm2, and p21WAF1, along with the MIB-1-labeling index (MIB-1-LI) in 21 WDLS and 21 DDLS cases, to clarify the association of these markers with the morphologic changes and the biological factors responsible for the aggressiveness of DDLS. Within DDLS, p53 and p21WAF1 expression and mdm2 overexpression were significantly more prevalent in the dedifferentiated (DD) components than in the well-differentiated (WD) components. The mdm2 overexpression and p21WAF1 expression was significantly associated with sclerosing liposarcomas in both WDLS and the WD components of DDLS. There was no significant difference in the immunoreactivity of p53, mdm2, or p21WAF1 or MIB-1-LI between WDLS and the WD components of DDLS. An association was found between p53 expression and mdm2 overexpression in the WD group (comprising WDLS and WD components of DDLS) and in the DD group, significantly so in the WD group. Notably, this correlation was found in the subtype of sclerosing liposarcoma but not in that of lipoma-like liposarcoma. Within DDLS, the clinical outcome of the nonaccessible soft tissue (non-AST: comprising retroperitoneum and mediastinum) group was significantly worse than that of the accessible soft tissue (AST: comprising extremities, buttocks, axilla, and scrotum) group; however, the immunophenotypes of p53, mdm2, and p21WAF1 and the MIB-1-LI showed no correlation with survival in the AST group alone, in the non-AST group alone, or in the 2 together. This study suggests that the immunoreactivity of p53, mdm2, and p21WAF1 is associated with the morphologic changes, but not with the biological factors responsible for the aggressiveness of DDLS.

[A case of cervical subpial lipoma]

The authors report the rare case of a 48-year-old woman with a cervical subpial lipoma unassociated with spinal dysraphism. Her symptoms were progressive weakness and numbness in the four extremities and the neurological symptom of mild cervical myelopathy. Plain radiographs of the cervical spine showed diffuse widening of the spinal canal, which was occupied by a large low-density mass revealed by axial CT scan. MR imaging identified the mass as being dorsolateral to the cord in the intradural region. It was hyperintense on both T1- and T2-weighted images. Axial images with fat suppression sequence clearly showed dorsal nerve roots traveling through the lesions, but the interface between the spinal cord and lesion was not well demarcated. A cervical laminectomy between C3-6 revealed a yellowish subpial mass after the dura was opened. The mass was only partially resected and intraoperative SEP monitoring data remained normal including N20 latency. Histological examination found mature adipose tissue covered by thickened pia mater, which was compatible with a diagnosis of lipoma. After surgery, no complications occurred and the patient's myelopathy subsequently improved. Subpial spinal lipomas unassociated with dysraphism are uncommon and they are reported in only 1% of all spinal cord tumors. They are thought to arise from premature dysjunction of the cutaneous ectoderm during neural tube formation. Without any invasive procedure, MR imaging is indispensable to show their longitudinal dimension as well as their infiltrative extension into the spinal cord. The main purpose of surgery is to decompress the lipoma from the adjacent neural structures, because it is benign in nature and there is no cleavage plane identifiable between the lipoma and the spinal cord.

Metabolism of levo-alpha-Acetylmethadol (LAAM) by human liver cytochrome P450: involvement of CYP3A4 characterized by atypical kinetics with two binding sites

levo-alpha-Acetylmethadol (LAAM) is a long-acting opioid agonist prodrug used for preventing opiate withdrawal. LAAM undergoes bioactivation via sequential N-demethylation to nor-LAAM and dinor-LAAM, which are more potent and longer-acting than LAAM. This study examined LAAM and nor-LAAM metabolism using human liver microsomes, cDNA-expressed CYP, CYP isoform-selective chemical inhibitors, and monoclonal antibody to determine kinetic parameters for predicting in vivo drug interactions, involvement of constitutive CYP isoforms, and mechanistic aspects of sequential N-demethylation. N-Demethylation of LAAM and nor-LAAM by human liver microsomes exhibited biphasic Eadie-Hofstee plots. Using a dual-enzyme Michaelis-Menten model, K(m) values were 19 and 600 microM for nor-LAAM and 4 and 450 microM for dinor-LAAM formation, respectively. LAAM and nor-LAAM metabolism was inhibited by the CYP3A4-selective inhibitors troleandomycin, erythromycin, ketoconazole, and midazolam. Of the cDNA-expressed isoforms examined, CYP2B6 and 3A4 had the highest activity toward LAAM and nor-LAAM at both low (2 microM) and high (250 microM) substrate concentrations. N-Demethylation of LAAM and nor-LAAM by expressed CYP3A4 was unusual, with hyperbolic velocity curves and Eadie-Hofstee plots and without evidence of positive cooperativity. Using a two-site model, K(m) values were 6 and 0.2 microM, 1250 and 530 microM, respectively. Monoclonal antibody against CYP2B6 inhibited CYP2B6-catalyzed but not microsomal LAAM or nor-LAAM metabolism, whereas troleandomycin inhibited metabolism in all microsomes studied. The ratio [dinor-LAAM/(nor-LAAM plus dinor-LAAM)] with microsomes and CYP3A4 decreased with increasing LAAM concentration, suggesting most dinor-LAAM is formed from released nor-LAAM that subsequently reassociates with CYP3A4. Based on these results, we conclude that LAAM and nor-LAAM are predominantly metabolized by CYP3A4 in human liver microsomes, and CYP3A4 exhibits unusual multisite kinetics.

Cytochrome P4502B6 and 2C9 do not metabolize midazolam: kinetic analysis and inhibition study with monoclonal antibodies

We determined the contribution of cytochrome P450 (CYP) isoforms to the metabolism of midazolam by kinetic analysis of human liver microsomes and CYP isoforms and by examining the effect of chemical inhibitors and monoclonal antibodies against CYP isoforms in vitro. Midazolam was metabolized to 1'-hydroxymidazolam (1'-OH MDZ) by human liver microsomes with a Michaelis-Menten constant (Km) of 4.1 (1.0) (mean (SD)) micromol litre(-1) and a maximum rate of metabolism (Vmax) of 5.5 (1.1) nmol min(-1) mg protein(-1) (n = 6). Of the nine representative human liver CYP isoforms, CYP1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4 and 3A5, three (CYP2B6, 3A4 and 3A5) showed midazolam 1'-hydroxylation activity, with Kms of 40.7, 1.7 and 3.0 micromol litre(-1), respectively, and Vmax values of 12.0, 3.3 and 13.2 nmol min(-1) nmol P450(-1), respectively (n = 4). Midazolam 1'-hydroxylation activity of human liver microsomes correlated significantly with testosterone 6beta-hydroxylation activity, a marker of CYP3A activity (r2 = 0.77, P = 0.0001), but not with S-mephenytoin N-demethylation activity, a marker of CYP2B6 activity (r2 < 0.01, P = 0.84) (n = 11). Troleandomycin and orphenadrine, chemical inhibitors of CYP isoforms, inhibited the formation of 1'-OH MDZ by human liver microsomes. Monoclonal antibody against CYP3A4 inhibited the formation of 1'-OH MDZ by 79%, whereas monoclonal antibody against CYP2B6 had no effect on midazolam 1'-hydroxylation by human liver microsomes (n = 5). These results indicate that only CYP3A4, but not CYP2B6 or CYP2C, is involved in the metabolism of midazolam in vitro.

Immobilization of bisphosphonates on surface modified titanium

The efficiency of surface modifications on the immobilization of bisphosphonates on titanium was investigated with Ca-ion implantation and thin hydroxyapatite coatings. The ALP activity of osteoblastic cells and the inhibitory effects on the initial adherence of P. gingivalis were also evaluated using bisphosphonate-immobilized titanium. X-ray photoelectron spectroscopy analysis suggested that titanium surfaces modified with Ca-ion implantation and thin hydroxyapatite coatings caused the immobilization of bisphosphonate on titanium plates. The ALP activity of osteoblastic cells cultured on plates immobilized with bisphosphonate was almost the same as that of cells cultured on titanium plates, indicating that the bisphosphonate-immobilization showed no toxic effect on osteoblastic cells, and that it provides a favorable micro-environment with osteogenetic ability. Data of the adherence of oral bacteria showed that a bisphosphonate-immobilized titanium surface inhibited the initial adherence of P. gingivalis. These results indicate that the immobilization of bisphosphonates on titanium modified with Ca-ion implantation and thin hydroxyapatite coatings are useful for dental implants.

Engineering neoglycoproteins with multiple O-glycans using repetitive pentapeptide glycosylation units

Controlled protein remodeling with O-linked glycans has been limited by our incomplete understanding of the process of glycosylation. Here we describe a secretable fibroblast growth factor (FGF) with multiple mucin-type O-glycans produced by introducing a minimum pentapeptide glycosylation unit in a decarepeat format at its N- or C-terminus. Expressed in Chinese hamster ovary cells, chemical and biochemical analyses of the resultant proteins (Nm10-FGF and Cm10-FGF, respectively) demonstrated that all O-glycosylation units were glycosylated and the dominant structure was sialylated Gal[beta1-3]GalNAc. This indicates that minimum O-glycosylation unit in multirepeat format serves as a remarkably efficient acceptor in CHO cells. The Nm10-FGF and Cm10-FGF proteins maintained the mitogenic activity to vascular endothelial cells. In addition, intact Cm10-FGF and its desialylated form interacted with several lectins in the same way as mucin-type glycoproteins. The intact Cm10-FGF with multiple sialylated O-glycans exhibited a longer lifetime in circulating blood, whereas the Cm10-FGF with desialylated O-glycans exhibited a shorter lifetime than the deglycosylated form of Cm10-FGF. Our approach would thus appear to be highly effective for engineering neoglycoproteins, the characteristics of which are determined by their multiple mucin-type O-glycans.

H-ras oncogene mutation in dedifferentiated chondrosarcoma: polymerase chain reaction-restriction fragment length polymorphism analysis

Dedifferentiated chondrosarcomas, which are known for their poor prognosis, are characterized by conventional chondrosarcoma with high-grade anaplastic components. Activating mutations in ras genes are a common genetic abnormality in human malignancies. The presence of point mutations at codons 12 and 13 of the H-ras gene was studied in 20 formalin-fixed paraffin-embedded chondrosarcomas, comprising 11 cases of conventional chondrosarcoma (six Grade 1 cases and five Grade 2 cases) and nine cases of dedifferentiated chondrosarcoma, using polymerase chain reaction-restriction fragment length polymorphism and direct sequencing analysis. H-ras mutations were only seen in two out of the nine cases of dedifferentiated chondrosarcoma (2/9, 22%) and they were not seen in any of the cases of conventional chondrosarcoma (0/11, 0%). Dedifferentiated chondrosarcomas had a worse prognosis than conventional chondrosarcomas (P < .01); among the patients with dedifferentiated chondrosarcomas, those with H-ras mutation (n = 2) tended to have a worse prognosis than those without (n = 7), although the difference was not statistically significant (P = 0.068). Our results would seem to suggest that H-ras mutation may occur during the course of dedifferentiation and may also have some effect on malignant potential.