Construction of 144, 565 keV and 5.0 MeV monoenergetic neutron calibration fields at JAERI

Monoenergetic neutron calibration fields of 144, 565 keV and 5.0 MeV have been developed at the Facility of Radiation Standards of JAERI using a 4 MV Pelletron accelerator. The 7Li(p,n)7Be and 2H(d,n)3He reactions are employed for neutron production. The neutron energy was measured by the time-of-flight method with a liquid scintillation detector and calculated with the MCNP-ANT code. A long counter is employed as a neutron monitor because of the flat response. The monitor is set up where the influence of inscattered neutrons from devices and their supporting materials at a calibration point is as small as possible. The calibration coefficients from the monitor counts to the neutron fluence at a calibration point were obtained from the reference fluence measured with the transfer instrument of the primary standard laboratory (AIST), a 24.13 cm phi Bonner sphere counter. The traceability of the fields to AIST was established through the calibration.

Gold sodium thiomalate suppresses the differentiation and function of human dendritic cells from peripheral blood monocytes

OBJECTIVE

Gold sodium thiomalate (GST) is a drug commonly used for the treatment of rheumatoid arthritis (RA). To clarify the mechanism of therapeutic effects of GST on RA, we investigated if GST affects the differentiation of dendritic cells (DC), which are thought to play a pivotal role in RA pathogenesis.

METHODS

We generated immature DC (iDC) in vitro from PB monocytes during the 5 to 7-day culture in the presence of IL-4 and GM-CSF. Mature DC (mDC) were induced by adding TNF alpha on day 5 of the 7-day culture with GM-CSF and IL-4. DC capacity of stimulating T cells was examined in allogenic MLR using generated DC as stimulators. IL-12 production from DC was assayed with ELISA.

RESULTS

We found that: 1) mDC generated in the presence of GST showed lower expression of CD1a, CD83, CD80, CD86, HLA-ABC and HLA-DR compared to control mDC on FACS analysis. 2) GST-treated mDC showed reduced capacity of stimulating allogenic T cells in mixed leukocyte reaction. 3) IL-12p70 production after stimulation with SAC or LPS plus IFN gamma was markedly reduced in GST-treated mDC.

CONCLUSION

GST suppresses the differentiation and function of DC generated from peripheral blood monocytes. This previously unknown action may explain the in vivo effects of GST in the treatment of RA.

Involvement of Bcl-2 family genes and Fas signaling system in primary and secondary male germ cell apoptosis induced by 2-bromopropane in rat

Epidemiological surveys and animal experimental studies suggest that exposure to 2-bromopropane (2-BP) could result in reproductive and hematopoietic disorders. The objectives of this study were to investigate the role of apoptosis in 2-BP-induced testicular toxicity and whether this process involves Bcl-2 family genes and the Fas signaling system. Rats were injected percutaneously with 1350 mg/kg 2-BP for 1 to 5 days and then were euthanized at 6 or 12 h after one dose, 6 h after two, three, or five doses, and 2 or 9 days after the final treatment. Light and electron microscopic analyses, TUNEL staining of DNA fragments, agarose gel electrophoresis of low-molecular-weight DNA, and Western blotting analysis of Bcl-2 family proteins and Fas receptor and ligand were conducted. Two-day treatment resulted in selective degeneration of spermatogonia with marked nuclear chromatin condensation. DNA ladder formation on the agarose gel further validated the findings of TUNEL-stained apoptotic cells. The percentage of apoptotic-positive tubules and apoptotic cell index increased time dependently. 2-BP treatment resulted in two distinct morphological changes: an immediate effect on spermatogonia and secondary apoptosis of spermatocytes 9 days after treatment. Downregulation of Bcl-2 after the first or second injection of 2-BP and upregulation of Bax after the first treatment contributed to the initiation of primary apoptosis of spermatogonia. Expression of FasL was inhibited while expression of Fas increased after the 2-BP treatment and remained at levels about two times of the control. However, it increased about sixfold of the control by day 9 after final injection, which contributed to the induction of secondary apoptosis of spermatocytes. Our results indicate that 2-BP resulted in apoptotic death of testicular germ cells and that this process involves the Bcl-2 family genes and the Fas signaling system.

Picryl chloride-induced allergic dermatitis in IQI/Jic female mice

IQI/Jic (IQI) mice are an ICR-derived inbred strain developed in Japan, and it is known that aged females of this strain develop allergic dermatitis of spontaneous nature. In the present study, young IQI female mice which were sensitized with picryl chloride (PCL) to the shaved skin of abdomen and then topically applied with PCL to the ear at 4, 11, 18 and 25 days after the sensitization were examined. The ear swelling response increased rapidly after the 1st application, peaked after the 2nd one, and then gradually decreased. Histopathologically, edema with inflammatory cell infiltration developed after the 1st application and progressed after the 2nd one. The number of mast cells, CD4-positive cells and MHC class II-positive cells became prominent accompanied with epidermal thickening and dermal fibroplasia after the 4th application when clear elevation of total serum IgE levels was observed in many mice. Compared with the dermatitis induced in the same way in BALB/c female mice, the nature was similar with each other but the degree was obviously severer in IQI female mice. IQI female mice are considered to be a useful laboratory animal for the investigation of allergic dermatitis.

Expression of cytokines and proteases in mast cells in the lesion of subcapsular cell hyperplasia in mouse adrenal glands

To examine the possible roles of mast cells in the pathogenesis of subcapsular cell hyperplasia (SCH) in the adrenal glands of mice, we investigated the expression of certain cytokines, including stem cell factor (SCF), tumor necrosis factor-alpha (TNF-alpha), nerve growth factor (NGF), and basic fibroblast growth factor (bFGF), and mast cell-specific proteases, such as mouse mast cell protease (mMCP)-2 and mMCP-7. The mRNAs of c-kit (SCF receptor), bFGF, TNF-alpha, mMCP-2, and mMCP-7 were expressed in both the adrenal glands and the mouse bone marrow-derived mast cells (mBMMCs). Immunoreactivities for cytokines (SCF, NGF, TNF-alpha) and proteases (mMCP-2, mMCP-7) were exclusively located in the mast cells in SCH lesions. The immature mBMMCs did not express the mRNAs of SCF and NGF, whereas the mast cells in the SCH lesions showed the expression of SCF and NGF. These findings suggest that SCH may provide a favorable microenvironment for functional maturation of mast cells to produce SCF and NGF, and the mast cells in SCH lesions synthesize SCF and NGF and may, in part, use them in autocrine fashion for their survival and differentiation. Therefore, mast cells may contribute to SCH pathogenesis by producing a range of multifunctional cytokines and proteases.

[The radiographic report of soft tissue tumor on the legs in a case of cutaneous polyarteritis nodosa]

A 55-year-old male was admitted to our hospital because of arthralgia, rash, and painful tumor in the legs. On admission, skin lesions involving dark erythematous macules and a tender mass of 3 by 5 cm were present. Laboratory findings included hemoglobin of 11.2 g/dl, white blood cell count of 6200/microliter, erythrocyte sedimentation rate (ESR) of 88 mm/hour, and normal results of renal function tests. Hepatitis B surface antigen, anti-nuclear antibody (ANA), and perinuclear pattern antineutrophil cytoplasmic autoantibody (ANCA) were negative. A T 1-weighted magnetic resonance image (MRI) showed iso-intensity areas that increased in intensity on T 2-weighted images of the M. gastrocnemius. The angiographic appearance of tumor staining with some degree of luminal irregularity in the posterior tibial artery suggested a diagnosis of soft tissue neoplasm. Biopsy specimens of the right leg lesion were consistent with necrotizing arteritis of both small and medium-sized vessels. Treatment with prednisolone and cyclophosphamide resulted in the disappearance of the skin lesions and the improvement of laboratory data. At first, classical polyarteritis nodosa was considered histologically. However, lesions were limited to skin, muscles, and joints, and there has been no evidence of systemic disease for 1.5 years; consequently, cutaneous form of polyarteritis nodosa was diagnosed. Reports of soft tissue tumors on the legs of patients with polyarteritis nodosa are quite rare. The interesting radiographic findings of cutaneous polyarteritis nodosa were reported.

Subcapsular cell hyperplasia and mast cell infiltration in the adrenal cortex of mice: comparative study in 7 inbred strains

Subcapsular cell hyperplasia (SCH) in the adrenal cortex of aged mice (13-15 months old) was frequent in both sexes of BALB/c, C3H/He, DBA/2J and IQI/Jic mice and in the females of A/J and C57BL/6, although the incidence and severity of SCH were considerably different among mouse strains. Mast cells were closely associated with SCH in the A/J, BALB/c, C57BL/6, DBA/2J and IQI/Jic mice, but not in the C3H/He strain. Compared with other strains, IQI/Jic mice had a significantly larger number of mast cells in the adrenal glands. Our findings suggest that mast cells may participate in the development of SCH, and IQI/Jic would be suitable for studying the pathogenesis of SCH and the role of mast cells in this lesion.

Sialadenitis in IQI/Jic mice: a new animal model of Sjögren's syndrome

Focal infiltration of lymphocytes with parenchymal destruction was noted in both salivary and lacrimal glands of IQI/Jic mice. The sialadenitis was found in more than 80% of female mice at all ages examined. The lesion progressed after 6 months and became more prominent with age. In contrast, male mice had slight and stable salivary lesions independent of age, though the incidence increased with age. Infiltrating lymphocytes consisted of both T and B cells. The dominant lymphocytes in small foci were CD4+ cells, but the majority of infiltrating cells were B cells (B220+), followed by CD4+ T cells in larger lesions. The ductual epithelium in the foci aberrantly expressed MHC class II antigen. Eight of 24 15-month-old female mice with sialadenitis produced speckled-type IgG antinuclear autoantibody. These findings are similar to those in patients with Sjögren's syndrome. IQI/Jic mice could be a novel animal model of Sjören's syndrome.

Correlation of mast cells with spindle cell hyperplasia in the adrenal cortex of IQI/Jic mice

IQI/Jic mice showed a high incidence of subcapsular spindle cell hyperplasia (SCH) in the adrenal cortex accompanied by prominent mast cell infiltration. SCH-positive animals appeared as early as at 3 months of age, with an incidence of 18% in males and 20% in females. Except for one mouse, all females older than 6 months had the lesion. In males, the incidence increased gradually until 9 months, and was then stable at 75-88% thereafter. The severity of SCH increased with age in both sexes, and the lesions were more prominent in females. Mast cells infiltrated mainly at the sites of spindle cell hyperplasia, and their density was associated with the severity on the lesion. A quantitative morphometric study confirmed a significant correlation between the severity of SCH and the density of mast cells. A histochemical study demonstrated that these mast cells were of the connective tissue-type. These observations indicate that IQI/Jic mice may be a useful strain to elucidate the pathogenesis of SCH in the adrenal cortex in association with mast cell function.

IQI/Jic mice have thymic B cells

The thymus of IQI/Jic mice aged 3 to 15 months was studied chronologically by flow cytometry and immunohistochemistry. Thymic B cells (Thy B) expressing the surface marker B220+IgM+ were detected in both sexes, but were more prominent in females. Thy B appeared as early as 4 months of age in female mice, and the incidence of Thy B-positive mice and average Thy B ratio in thymocytes increased with age, reaching over 90% and 15%, respectively, after 9 months of age. In males, Thy B-positive animals appeared around 9 months of age and its incidence and average ratio increased gradually to 53% and 5%, respectively, at 15 months. The Thy B-rich thymus was thickened with cortical atrophy and medullary hyperplasia. Small- to medium-sized Thy B crowded and often formed follicle-like structures in the medulla. When mice of various ages were injected with mercuric chloride to induce antinucleolar antibody, many Thy B-rich animals could not develop the antibody, implying that these animals are immunologically impaired. IQI/Jic can be a novel strain to elucidate the relationship between the presence of Thy B and disorders of the immune system.

Antinucleolar autoantibody induced by mercuric chloride in mice: does sodium selenite inhibit autoantibody production?

Repeated exposure of subtoxic doses of mercuric chloride (HgCl2) can induce antinucleolar autoantibodies in susceptible mice. To study the immunopathological mechanism(s), sodium selenite (Na2SeO3), which is known to reduce the toxicity of mercury, is injected simultaneously with HgCl2 into mice. Equimolar Na2SeO3 nor the same amount of Se in Na2SeO3 as Hg in HgCl2 could not reduce antinucleolar autoantibody induction by HgCl2. These results indicate that the mechanism of autoimmunity induction by HgCl2 might be independent of its toxicity.

Deodorization of laboratory animal facilities by ozone

Deodorizing effect of ozone was investigated comparing two types of compact ozonizing apparatus made on an experimental basis. The concentrations of ammonia and trimethylamine were examined as an indicator for deodorizing effect of ozone in animal rooms of rats and guinea pigs at laboratory animal facilities of three different universities. Both of the ozonizing apparatus were able to remove ammonia and trimethylamine in animal rooms, with no significant difference in the performance of the two apparatus.

Analysis of mammalian metallothionein isoforms by high-resolution SDS-gel electrophoresis

Metallothioneins (MTs) are cysteine-rich heavy metal-binding proteins, whose possible functions are thought to be the protection against toxic metals as well as the regulation of essential metals. It is known that there are several MT isoforms, but the biological roles of the individual isoforms have not been elucidated. To facilitate the functional analysis of these isoforms, we improved an analytical method of MTs developed previously, which is based on a denaturing gel electrophoresis of chemically modified MTs. The established technique makes it possible not only to separate MT isoforms with a high resolution, but to estimate the levels of the individual isoforms by analyzing directly crude cell extracts. By this method, six MT isoforms were identified in the extracts of Cd-exposed human cells. It was also revealed that there is an apparent heterogeneity of the rat liver MT; five isoforms were identified in the liver extracts of Cd-injected rats. The present method will be useful in the functional analysis of the MT isoforms, as well as in a variety of aspects of the MT studies.

WHT/Ht mouse contains plasma cells in the thymus

Numerous plasma cells and B cells were present in the thymuses of aged WHT/Ht mice. Plasma cells containing IgG and the follicle-like structure were present in the cortex and medulla, respectively. In these respects, WHT/Ht strain of mice is unique and interesting for studies on lymphocyte development.

Antinucleolar autoantibody induced in mice by mercuric chloride--strain difference in susceptibility

Eight inbred mouse strains were examined for their reactivity to the induction of antinucleolar autoantibody (AnuA) by mercuric chloride (MC). According to the positive ratio and titer of AnuA induced, the strains were grouped into high-, moderate-, low-, and non-responders. Since the susceptibilities to MC were different among strains having the same H-2 haplotype, involvement of H-2 unlinked gene (s) in AnuA induction by MC was suggested.

[Efficacy of a 48-hour infusion of 5-fluorouracil in patients with stage IV gastric cancer after palliative gastrectomy]

Efficacy of a 48-hour infusion of 5-FU in patients with stage IV gastric cancer was investigated. A one-cycle regimen consisted of a 48-hour infusion of 5-FU (30 mg/kg/24 hours) every week for 6 weeks. Fourteen patients with stage IV gastric cancer who underwent absolutely non-curative gastrectomy, received 5-FU infusion postoperatively. Ten of the 14 received more than 2 cycles. Survival rates in these patients (group I) were evaluated by Kaplan-Meier method and compared with those of matched pair controls (group II) who received other anticancer agents. Side effects were generally mild. Nausea during infusion was observed in only 3 cases. The 50% survival period was 393 days in group I and 135 days in group II, respectively. The survival curve in group I was significantly higher than in group II (p = 0.05). From these results, this treatment is considered to be very effective.

Massive endometriosis in two rhesus monkeys

Massive endometriosis was found in two rhesus monkeys during a chronic toxicological experiment. These cases had metastatic lesions in lymph nodes in addition to the foci on the serosal wall of pelvic organs. Invasion to the intestinal mucosal layer was also noted in a case. These observation indicated that endometriosis in the rhesus monkey might behave like a malignant neoplasm.

Thromboxane A2 synthetase inhibitors. 2. Syntheses and activities of tetrahydronaphthalene and indan derivatives

A series of 1-imidazolylalkyl-substituted or 5-thiazolylalkyl-substituted tetrahydronaphthalenecarboxylic acid and indancarboxylic acid derivatives were prepared and tested for the inhibitory activities of thromboxane A2 (TXA2) production in vitro and ex vivo. Most of the compounds showed potent TXA2 synthetase inhibitory activities in vitro and had long duration of inhibition of TXA2 production in rats when orally or intravenously administrated. The imidazole analogues had slightly less potency in vitro than the thiazole analogues, but the activities of the imidazole analogues in ex vivo models were equal or superior to the activities of the thiazole analogues. 6-(1-Imidazolyl-methyl)-5,6,7,8-tetrahydronaphthalene-2-carboxylic acid hydrochloride hemihydrate (47a, DP-1904) was chosen for clinical studies.

Age-related susceptibility to dibromochloropropane

To compare the acute toxic responses of weanling and adult rats to dibromochloropropane (DBCP), male 4- and 9-week-old rats were given subcutaneously 250 mg/kg DBCP. As compared to 4-week-old rats, 9-week-old rats showed higher mortality, more progressive weight loss and severer tissue injuries in the testis, kidney, intestine and lymphoid organs. These results indicated that weanling rats were less susceptible to DBCP toxicity.

Molecular mimicry: frequency of reactivity of monoclonal antiviral antibodies with normal tissues

More than 600 monoclonal antiviral antibodies made against 11 different viruses were screened against 14 different organs from normal uninfected mice. Of these antiviral antibodies, 21, or approximately 3.5%, reacted with specific cells in these organs. Several of these antibodies were of the multiple-organ-reactive type and recognized antigens in more than one organ. It was concluded that the reactivity of monoclonal antiviral antibodies with normal tissues is a common phenomenon.

Cyclic guanidines. 17. Novel (N-substituted amino)imidazo[2,1-b]quinazolin-2 ones: water-soluble platelet aggregation inhibitors

A series of novel 1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin-2-one derivatives substituted with a secondary amino group has been prepared and tested for the activities of inhibiting platelet aggregation in rats in vitro and ex vivo. Most of the compounds were found to be the potent inhibitors of platelet aggregation. Some of the active compounds were soluble in water and effective via iv infusion in rats. Structure-activity relationships have indicated that a lipophilic secondary amino group located at position 6 or 7 contributed to retention of potent activity. Among the compounds studied, 7-piperidino-1,2,3,5-tetrahydroimidazo[2,1-b]quinazolin-2- one (13 g,DN-9693) was the most favorable compound.