Malignant meningioma with cartilage and giant cells.

An autopsy case of recurrent and malignant meningioma is reported. This case was originally typical benign transitional meningioma of the falx, however, the histology of the tumor changed to show malignant features during successive recurrences. At autopsy, the tumor revealed findings consistent with malignant meningioma. One of the most interesting features was the presence of cartilage and giant cells in some parts. Immunohistochemistry showed positive immunoreactivity for S-100 protein in some cartilage and giant cells and for cytokeratin in some giant cells. Multidifferential potential of the meningioma cells was suggested in this case.     

Effects of lincomycin and tetracycline on production and properties of enterotoxins of enterotoxigenic Escherichia coli

Enterotoxigenic Escherichia coli grown in the presence of lincomycin and tetracycline produced an increased amount of heat-labile enterotoxin (LT). These antibiotics increased the production of not only extracellular LT but also intracellular LT. On the other hand, lincomycin did not stimulate the production of heat-stable enterotoxin by enterotoxigenic E. coli. The extracellular LTs produced in the presence of lincomycin and tetracycline were purified and analyzed by sodium dodecyl sulfate-polyacrylamide gel disc electrophoresis. Results showed that the A subunits of the purified LTs were not nicked, unlike that of extracellular LT produced in the absence of the antibiotics.     

Production of monoclonal antibodies against thermostable direct hemolysin of Vibrio parahaemolyticus and application of the antibodies for enzyme-linked immunosorbent assay

A total nine hybridoma cell lines that produced monoclonal antibodies against thermostable direct hemolysin (Vp-TDH), a possible pathogenic toxin, of Kanagawa phenomenon-positive Vibrio parahaemolyticus was isolated and characterized. These monoclonal antibodies (mAbs) were divided into a minimum of five different specificity groups, including mAbs specific to Vp-TDH and common to Vp-TDH and Vp-TRH, a Vp-TDH-related hemolysin produced by Kanagawa phenomenon-negative V. parahaemolyticus. An enzyme-linked immunosorbent assay (ELISA) using mAb-1-D, a mAb specific for Vp-TDH, was developed for specific detection of Vp-TDH. On the other hand, the ELISA using mAb-9-D, and mAb common to both Vp-TDH and Vp-TRH, could be used for detection of both Vp-TDH and Vp-TRH. Thus, by combining these two ELISAs differential detection of Vp-TDH and Vp-TRH can be performed. Hence, the two ELISAs were applied for various strains of V. parahaemolyticus and it was found that most Kanagawa phenomenon-positive and -negative clinical isolates produced Vp-TDH and Vp-TRH, respectively, but all environmental strains, that were Kanagawa phenomenon-negative, produced neither toxin.Supported by a Grant-in-Aid for Scientific Research and a Grant-in-Aid for Developmental Scientific Research from the Ministry of Education, Science, and Culture of Japan     

Radiation-induced reactive oxygen species formation prior to oxidative DNA damage in human peripheral T cells

Previously, we demonstrated that human peripheral T lymphocytes revealed early apoptotic changes (annexin V-positive) and late apoptotic changes (propidium iodide-positive), at 13 and 24 h, respectively, after irradiation of 5 Gy. Changes in mitochondrial membrane potential were observed at 10 h after irradiation of 5 Gy. Subsequently, mitochondrial cytochrome c-release was confirmed. In order to elucidate the mechanism which acts prior to the mitochondrial membrane potential changes, we examined in the previous study the radiation dose and the timing of oxidative DNA damage induced in human peripheral T lymphocytes following 10 MV X-ray irradiation. As a result, the production of 8-oxoguanine, i.e., the product of oxidative DNA damage, was clearly identified starting at 10, 6, and 3 h, after 2, 5, and 20 Gy of irradiation, respectively. Therefore, we examined in the present study reactive oxygen species (ROS) formation in T lymphocytes following 5 Gy of irradiation. Using a CCD camera system, we monitored fluorescence in T lymphocytes loaded with the succinimidyl ester of dichlorodihydrofluorescein diacetate (H2DCFDA), which is non-fluorescent until oxidized by ROS. We found that ROS formation occurred immediately after irradiation, continued for several hours, and resulted in oxidative DNA damage. Therefore, the origin of hyper-radiosensitivity of T lymphocytes seemed to be the high production of ROS in the mitochondrial DNA following irradiation.     

Molecular cloning and expression analysis of a macrophage-colony stimulating factor receptor-like gene from rainbow trout, Oncorhynchus mykiss

The M-CSF and its receptor (M-CSFR, CSF-1R or c-fms proto-oncogene) system were initially implicated as essential in mammals for normal monocyte development as well as for pregnancy. To allow a comparison with the M-CSF and M-CSFR system of an oviparous animal, we cloned a M-CSFR-like gene from rainbow trout (Oncorhynchus mykiss). The gene was cloned from a cDNA library of head kidney. It contained an open reading frame encoding 967 amino acids with a predicted size of 109 kDa. The putative amino acid sequence of rainbow trout M-CSFR showed 54% amino acid identity to fugu (Takifugu rubripes) M-CSFR, 52% to zebrafish (Danio rerio) M-CSFR and 40% to mouse (Mus musculus) and human (Homo sapiens) M-CSFR. The M-CSFR-like gene was constitutively expressed in head kidney, kidney, intestine, spleen and blood. The gene was detected especially in the ovary of immature female rainbow trout. These results suggest that a M-CSFR-like receptor may be involved in female reproductive tracts even in an oviparous animal like fish.     

Molecular and immunological approach to hematological disease: detection and analysis of intracellular modified nucleosides by flow cytometry

Modified nucleosides are components of ribosomal RNA (rRNA), transfer RNA (tRNA) and messenger RNA (mRNA). 1-methyladenosine and pseudouridine are members of those modified nucleosides. The urinary concentration of 1-methyladenosine and pseudouridine of cancer patients are higher than that of healthy controls, and those compounds were reduced after effective chemotherapy. Thus those compounds might be expected to use as tumor markers. In this study cellular origin of 1-methyladenosine and pseudouridine were analysed about two tumor cell lines (HUT-102, THP-1), peripheral blood lymphocytes (PBL) from healthy adult and PBL under the phytohemagglutinin stimulation, by flow cytometric analysis and immunofluorescent staining of cellular RNA using monoclonal antibodies specific for 1-methyladenosine (AMA) and pseudouridine (APU). Both 1-methyladenosine and pseudouridine were detected in more than 90% of tumor cells above the thresholds of flow cytometric detection (Spectrum III, Ortho). The PBL under the PHA stimulation also tended to take the same way of the tumor cell lines, whereas few of the PBL contained 1-methyladenosine above the thresholds. According to the DNA analysis of those cell lines, high contents of the modified nucleosides in the cell might follow DNA synthesis, this leads to one reason for high levels of the urinary excretion of the modified nucleosides in cancer patient.     

Detection of the putative E2 protein of hepatitis C virus in human liver

The question was asked whether a predicted envelope protein, considered to be processed from the polyprotein precursor encoded by the putative E2/NS1 region of the hepatitis C virus (HCV) genome, may be observed in HCV-infected humans. Two polyclonal antibodies against recombinant E2/NS1 proteins were prepared and their reactivity tested against liver extracts from HCV-infected patients by immunoblotting analysis. A band corresponding to a size of 44 kDa was detected in liver extracts from patients who were positive for the HCV-specific antibody anti-C100-3 but not in liver extracts from patients who did not have anti-C100-3 antibody. Additionally, no band was detected using preimmune sera or antisera which had been preabsorbed with recombinant E2/NS1 proteins. Deglycosylation studies demonstrated that the 44 kDa protein was a glycosylated form of a 38 kDa protein which corresponds to the predicted molecular weight of the putative E2/NS1 protein. These results suggest that the 44 kDa protein is a product of the E2/NS1 region. Frequent observation of the 44 kDa band in cases of chronic active hepatitis C suggests a correlation between the expression of this protein and the progression of hepatitis. © 1994 Wiley-Liss, Inc.     

Detection of mutations in the enhancer 2/core promoter region of hepatitis B virus in patients with chronic hepatitis B virus infection: comparison with mutations in precore and core regions in relation to clinical status

To investigate the meaning of the mutations in the enhancer 2/core promoter (Enh2/CP) region of hepatitis B virus (HBV) during the chronic HBV infection, mutations were examined in the Enh2/ CP region (carboxyl half of X region) and their correlation with mutations in the precore and core regions in relation to the presence of chronic liver disease. The entire nucleotide sequences of the Enh2/CP region were determined by direct sequencing of the amplified products derived from 30 cases with chronic HBV infection. The results were compared to the mutations in the precore and core regions. In the Enh2/CP region, 91 generally scattered nucleotide substitutions were detected. There were 11 substitutions in the 10 asymptomatic healthy carriers (mean, 1.1/case) and 80 in the 20 chronic liver disease patients (4.0/case). The most frequent substitutions from A to T at nucleotide 1764 and from G to A at nucleotide 1766 were seen in none of the 10 asymptomatic carriers and in 14 (70%) of the 20 chronic liver disease patients. Comparisons of mutations in the precore and core regions revealed that 14 of 16 patients with mutations in the core region had the mutations in the Enh2/CP region and/or a precore stop codon mutation. These data suggest that mutations in the Enh2/CP and precore regions may affect the expression of the core and HBeAg peptides and might be involved in the pathogenesis of chronic liver disease.     

Influence of the parameters of several pulse sequences on the image contrast: comparison between the two major contrast media

We compared the influences of the parameters of several pulse sequences using two major commercially available gadolinium (Gd) contrast media for MR imaging. The phantom of Gd solutions of various concentration (0.1 - 10mmol/L) was prepared, and was scanned with a 1.5T clinical MR unit, using a spin-echo T1-weighted sequence, 2DFLASH, 3DFLASH, and 3DVIBE. The signal intensity was measured and the contrast enhancement ratio (CER) was calculated and plotted as a function of Gd concentration. The results were compared between the pulse sequences, and between the contrast media as well. Both 3DFLASH and 3DVIBE showed higher CER than other two sequences, showing similar CER curve configuration. There was no significant difference both in CER value and CER curve configuration between the two contrast media for each pulse sequence.