Five-sixth Nephrectomy in Female Common Marmosets(Callithrix jacchus) as a Chronic Renal Failure Model: -A Longitudinal Course of Serum Biochemical, Hematological and Histopathological Changes-.

To assess the relevance and availability of subtotal nephrectomized common marmoset monkeys as a chronic renal failure (CRF) model, we observed for 26 weeks the pathophysiological condition of female marmosets subjected to five-sixth surgical nephrectomy (5/6Nx) by a two-step surgical method. The 5/6Nx marmosets showed a significant increase in serum levels of urea nitrogen, creatinine and cystatin-C immediately after 5/6Nx surgery. These renal disorder parameters subsequently tended to decrease with the passage of time but remained higher than the control levels by the end of the study. Hyperplastic parathyroid glands, a high turnover state of osteodystrophy in the femoral bone with higher serum ALP activity and anemia with hypocellularity of bone marrow were evident. The 5/6Nx marmosets showed a stable CRF condition for a long time and some characteristic disorders similar to those observed in CRF patients. These diagnostic aspects might be a species-specific anatomical and physiological signature, reflecting the nutritional condition. The CRF model using 5/6Nx marmosets might become a useful method of evaluating the unique mechanism of CRF development.

Spontaneous Malignant T Cell Lymphoma in a Young Male Common Marmoset (Callithrix jacchus).

We histopathologically and immunohistochemically investigated a case of malignant lymphoma that spontaneously developed in a male common marmoset at two years of age. Beginning at two years four months of age, the animal had an enlargement of the submandibular and inguinal lymph nodes, small subcutaneous nodules near the right breast and an approximately fivefold increase in peripheral lymphocyte count compared with the previous examination value. The postmortem findings at two years eight months of age showed lymphadenopathy with enlargement of the thymus and spleen. Small- to intermediate-sized neoplastic lymphocytes had diffusely proliferated in the enlarged nodes. The neoplastic cells were pleomorphic and had irregularly shaped nuclei. The nuclear chromatin staining revealed hyperchromatism in the small-sized cells, and the intermediate-sized cells exhibited vesicular staining. An immunohistochemical examination indicated that the neoplastic lymphocytes were positive for CD3 and negative for CD20, thus suggesting that they had originated from T cells. In addition, the proliferation of high endothelial venules and reactive epithelioid histiocytes was observed. Scattered tingible body-laden macrophages were infrequently detected. Neoplastic lymphocytes were also observed in the thymus, spleen, heart, lungs, liver, kidneys, adrenal glands and femoral and sternal bone marrow. This malignant lymphoma in a young male common marmoset was considered to fit the category of "peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS)" according to the new WHO system of classification.

Development of a method of evaluating PuO2 particle diameters using an alpha-particle imaging detector.

It is very important to evaluate the diameters (activity median aerodynamic diameter) of plutonium dioxide (PuO2) particles for internal exposure dose evaluation. In this study, a method of evaluating PuO2 particle diameters using an alpha-particle imaging detector was developed. PuO2 particles with different diameters were modeled by Monte Carlo simulation, and the change in the shape of the energy spectrum for each particle diameter was evaluated. Two different patterns were modeled, namely, the case of 239PuO2 and the case of PuO2 (including isotopic composition of Pu). Multiple regression analysis was performed to determine the PuO2 particle diameter from the obtained parameters. The simulated diameters and the diameters obtained with the regression model were in good agreement. The advantage of using the alpha-particle imaging detector is to measure the alpha energy spectrum for individual particle, and this allows accurate measurement of particle diameter distribution.

Spontaneous Adenosquamous Carcinoma with Rapid Growth and EMT-like Changes in the Mammary Gland of a Young Adult Female BALB/c Mouse.

This study histopathologically and immunohistochemically investigated a spontaneously occurring single mass subcutaneously located in the left lower abdomen of a female BALB/cAJcl-nu/+ mouse at 10 weeks of age. The mass was about 20 × 15 × 10 mm in size after formalin fixation; nevertheless, it was not detected by clinical observations at 9 weeks of age. H&E staining revealed the tumor origin was epithelial and probably arose from the mammary gland, and the tumor cells demonstrated a squamous, acinar or polyhedral/basal pattern. A cell kinetics analysis revealed that many of the tumor cells of the squamous, acinar or polyhedral/basal component were positive for PCNA and cyclin D1, although there were a few of TUNEL-positive tumor cells in all of the components. An epithelial/mesenchymal analysis demonstrated that most of the tumor cells of the squamous and acinar components contained keratin and E-cadherin; however, most of the tumor cells of the polyhedral/basal component were less or very weakly positive for these markers. The tumor cells of the squamous component were negative for vimentin and SMA; however, many of the tumor cells of the polyhedral/basal component exhibited vimentin. In addition, expression of SMA was confirmed in some tumor cells of the acinar and basal components. Based on the microscopic and immunohistochemical characterizations, the tumor was diagnosed to be adenosquamous carcinoma that originated from the mammary gland with rapid growth, and the tumor cells demonstrated epithelial-mesenchymal transition-like changes.

Effect of orally administered KF66490, a phosphodiesterase 4 inhibitor, on dermatitis in mouse models.

Due to the broad anti-inflammatory and immunomodulatory actions of phosphodiesterase (PDE) 4 inhibitors, it has been proposed that PDE4 inhibitors might be efficacious for skin disorders such as atopic dermatitis. KF66490 is a newly developed PDE4 inhibitor that inhibits PDE4B (IC(50)=220 nM) and the production of tumor necrosis factor (TNF)-alpha by mouse peritoneal exudated cells stimulated with lipopolysaccharide (IC(50)=855 nM). To evaluate efficacy of KF66490 in atopic dermatitis (AD) models, on skin inflammation induced by repeated application of 2,4,6-trinitro-1-chlorobenzene (TNCB) on ear in BALB/c mice and on spontaneously AD-like skin diseases in NC/Nga mice. BALB/c mice were sensitized with 0.3% w/v TNCB applied to the ear on day-7, followed by application three times a week from days 0 to 21. NC/Nga mice spontaneously developed dermatitis symptoms under conventional conditions. Test compounds were administered orally once daily during experiments. In the TNCB-induced dermatitis model, KF66490 significantly inhibited the increase in ear thickness and interleukin (IL)-4 and IL-1beta levels in the ear. Histopathological and immunohistochemical analysis revealed that KF66490 significantly inhibited the proliferation of fibroblasts and CD3-positive T cells infiltration into the ear. In addition, KF66490 significantly suppressed the development of dermatitis in NC/Nga mice on all observation days, except for 5 and 6 weeks after the first dose. Furthermore, KF66490 produced less potent emetic effects than the first generation PDE4 inhibitor, rolipram. The present results suggest that KF66490 has excellent potential as an oral medicine for the treatment of atopic dermatitis.

Experiences of Population Monitoring Using Whole-Body Counters in Response to the Fukushima Nuclear Accident.

Whole-body counter measurements of residents of Fukushima Prefecture have been extensively performed after the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. These measurements have demonstrated that the levels of internal contamination with radioactive cesium (Cs and Cs) in the residents are very low. This article provides an overview of and lessons learned from these whole-body counter measurements with emphasis on the technical problems encountered, and it discusses the effective use of whole-body counters for assessing the internal thyroid doses of individuals when direct measurements of I in the thyroid are difficult or impossible to implement for the total affected population in a short time after a nuclear reactor accident. The application of this dose reconstruction method requires determining the intake ratio of I to cesium isotopes at appropriate times and considers the short biological half-lives of cesium isotopes, in particular for children.

AN ACCIDENT OF INTERNAL CONTAMINATION WITH PLUTONIUM AND AMERICIUM AT A NUCLEAR FACILITY IN JAPAN: A PRELIMINARY REPORT AND THE POSSIBILITY OF DTPA ADMINISTRATION ADDING TO THE DIAGNOSIS.

This article introduces the first accident of internal contamination with plutonium (Pu) or americium (Am) in Japan for which treatment was carried out. An accident of internal contamination with Pu and Am occurred at a Pu research facility at Oarai-town of Ibaraki prefecture in Japan. A plastic bag containing these radionuclides ruptured when five workers were inspecting a storage container in a hood. As a consequence, these workers were internally contaminated with Pu and Am. Although contamination on the body surface was observed in all five workers, a positive nasal swab was detected in only three of them. A chelating agent, calcium diethylenetriaminepenta-acetate (CaDTPA), was administered to all of them including the two workers without a positive nasal swab. However, bioassay detected a significant amount of Pu and Am in urine after administration of DTPA in these two workers, whereas the levels of these nuclides were below minimum detectable levels in urine before the administration. Since the prevalence of adverse reactions in DTPAs is low, the present results suggest that administration of DTPA can be used for the diagnosis of internal contamination even when a nasal swab is negative or contamination around body orifices is not detected.

Comparison of the antiatherosclerotic effects of dihydropyridine calcium channel blocker and HMG-CoA reductase inhibitor on hypercholesterolemic rabbits.

The antiatherosclerotic effects of the dihydropyridine-type calcium channel blocker, benidipine hydrochloride (benidipine), and 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, pravastatin sodium (pravastatin), were compared in hypercholesterolemic rabbits. Male, New Zealand white rabbits were fed a 0.5% cholesterol diet. Pravastatin (10 mg/kg) or benidipine (10 mg/kg) was orally administered once daily after start of feeding. After 8 weeks of cholesterol feeding, serum cholesterol was increased and endothelial function of thoracic aorta was impaired. Pravastatin prevented elevation of serum cholesterol and aortic tunica intima hyperplasia. Although benidipine had little effect on serum cholesterol, it significantly inhibited aortic tunica intima hyperplasia and impairment of endothelial function. Expression levels of the vascular cell adhesion molecule-1 (VCAM-1) and lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) mRNA in aorta of hypercholesterolemic rabbit were higher than those of normal rabbit. Benidipine significantly prevented upregulation of VCAM-1 mRNA expression and showed a tendency to inhibit elevation of LOX-1 mRNA expression. Pravastatin significantly prevented upregulation of both VCAM-1 and LOX-1 mRNA expression. The results demonstrate that pravastatin inhibits increase of serum cholesterol and vascular dysfunction in hypercholesterolemic rabbit. Benidipine is effective in preventing vascular hyperplasia without altering serum cholesterol levels and this may be due to inhibition of expression of VCAM-1.

Development of 241Am lung monitoring system using an imaging plate.

A new 241Am lung monitoring system without shielding was devised by using an imaging plate system. The Lawrence Livermore National Laboratory's realistic torso phantom containing a 241Am lung was covered by imaging plates sealed in lightproof bags. The imaging plate system displayed 241Am lung images characteristic of the lung shape of the torso phantom. The imaging plate system's lower detection limits of 14 Bq for 60 min exposure and 6 Bq for 300 min were the same levels as those of the phoswich detectors and the germanium detectors placed in shielded rooms. The imaging plate system for 60 min exposure detected about 2% of the annual limit of 740 Bq for 241Am inhalation. A lung monitoring system using imaging plates is applicable for 241Am lung monitoring.

INTERNAL DOSES OF THREE PERSONS STAYING 110 KM SOUTH OF THE FUKUSHIMA DAIICHI NUCLEAR POWER STATION DURING THE ARRIVAL OF RADIOACTIVE PLUMES BASED ON DIRECT MEASUREMENTS.

The authors describe the results of direct measurements made on three persons who stayed in Tokai-mura, a village located ∼110 km south of the Fukushima Daiichi Nuclear Power Station (FDNPS), during the arrival of significant radioactive plumes released from the FDNPS as a consequence of the Tohoku earthquake/tsunami/FDNPS accident in March 2011. These measurements were made using a NaI(Tl) spectrometer and a whole-body counter shortly after the accident. Their thyroid equivalent doses ((131)I) were estimated to be 0.9-1.4 mSv under the assumption of acute intake via inhalation on 15 March, when the first significant release event was observed. Although greatly depending on the physicochemical form of iodine, the intake amount ratios of (131)I to (137)Cs for the three subjects were calculated as 2.7-3.7, which were much smaller than the radioactivity ratio (7.8) found in air sampling at the same site.

APPLICATION OF AN IMAGING PLATE FOR EVALUATING THE UNCERTAINTY IN DIRECT ORGAN MEASUREMENTS DUE TO VARIATION IN DETECTOR LOCATION.

In direct organ measurements, there can be uncertainty to the quantified amount of activity due to variations in detector locations. Here, the authors demonstrate a new use of an imaging plate (IP) for evaluating this uncertainty. The method requires only that an array of regions of interest (ROIs) is set on a latent image obtained from the IP; each ROI conforms to an active area of the detector to be used. In this study, the proposed method was tested in an experiment using a realistic torso phantom containing an (241)Am liver source. The latent image of this source was obtained by irradiating the IP (20 × 40 cm(2)) from the anterior surface of the phantom. A comparison of responses between the IP and a high-purity germanium detector was made for 6 of the 144 circular ROIs arranged on the latent image, showing excellent correlation between the two sets of measures. The dispersion of the photostimulated luminescence values of the 144 ROIs was found to be 8.2% (1σ) and 1.09 as a log-normal scattering factor, which was expected to be the same as the uncertainty of concern in the present measurement with the HPGe detector.

Analyses of a mouse model of the dermatitis caused by 2,4,6-trinitro-1-chlorobenzene (TNCB)-repeated application.

BACKGROUND: The model of chronic dermatitis caused by repeated application of hapten is frequently used as a tool for assessment of the efficacy of a compound or the elucidation of chronic dermatitis. OBJECTIVE: The purpose of this study is to provide more detailed analysis of the model of chronic dermatitis caused by repeated application of 2,4,6-trinitro-1-chlorobenzene (TNCB). METHODS: BALB/c mice were sensitized with TNCB on day -7 to the ear, and then TNCB was repeatedly applied to the same ear three times per week, through days 0-21. RESULTS: The repeated application of TNCB induced an increase of ear thickness, and a relatively steep increment of ear thickness from days 7 to 9 was observed. This increment reached almost a plateau at day 9. The peaks of ear swelling on days 7, 14 and 21 were approximately two times higher than that on day 0. Regarding cytokines in the ear, the highest production of IL-1 beta, 4, 6 and 18 were observed on day 7. The peak production of IL-1 beta, 4 and 6 on day 7 was found within 24 h after the challenge, while that of IL-18 was found at 0 h. The inflammatory cell infiltration into epidermis and dermis was observed and increased in day 7, then reached almost a plateau on day 9. CONCLUSION: The indices such as thickness, swelling and inflammatory cell infiltration in the lesional skin was increased and maintained by repeated application, however, the protein levels of some cytokines were not always consistent with the reactions.

Histopathological characterization of renal tubular and interstitial changes in 5/6 nephrectomized marmoset monkeys (Callithrix jacchus).

Common marmosets (Callithrix jacchus) have become a useful animal model, particularly for development of biopharmaceuticals. While various renal failure models have been established in rodents, there is currently no acceptable model in marmosets. We analyzed the damaged renal tubules and tubulointerstitial changes (inflammation and fibrosis) of 5/6 nephrectomized (Nx) common marmosets by histopathological/immunohistochemical methods, and compared these findings to those in 5/6 Nx SD rats. In Nx marmosets and rats sacrificed at 5 and 13 weeks after Nx, variously dilated and atrophied renal tubules were seen in the cortex in common; however, the epithelial proliferating activity was much less in Nx marmosets. Furthermore, the degrees of inflammation and fibrosis seen in the affected cortex were more severe and massive in Nx marmosets with time-dependent increase. Interestingly, inflammation in Nx marmosets, of which degree was less in Nx rats, consisted of a large number of CD3-positive T cells and CD20-positive B cells (occasionally forming follicles), and a few CD68-positive macrophages. Based on these findings, lymphocytes might contribute to the progressive renal lesions in Nx marmosets. Fibrotic areas in Nx marmosets comprised myofibroblasts expressing vimentin and α-smooth muscle actin (α-SMA), whereas along with vimentin and α-SMA expressions, desmin was expressed in myofibroblasts in Nx rats. This study shows that there are some differences in renal lesions induced by Nx between marmosets and rats, which would provide useful, base-line information for pharmacology and toxicology studies using Nx marmosets.

KF24345, an adenosine uptake inhibitor, ameliorates the severity and mortality of lethal acute pancreatitis via endogenous adenosine in mice.

Adenosine protects against cellular damage and dysfunction under several adverse conditions including inflammation and ischemia. In this study, we examined the effects of 3-[1-(6,7-diethoxy-2-morpholinoquinazolin-4-yl)piperidin-4-yl]-1,6-dimethyl-2,4(1H,3H)-quinazolinedione hydrochloride (KF24345), an adenosine uptake inhibitor, on experimental acute pancreatitis induced by choline-deficient and ethionine-supplemented diet in mice. KF24345, administered with the diet onset and every 24 h thereafter, prevented hyperamylasemia, acinar cell injury and serum tumor necrosis factor-alpha elevation and ultimately decreased mortality. Therapeutic treatment with KF24345, which started 32 h after the diet onset, also decreased mortality. The beneficial effect of KF24345 on mortality was abolished by the pretreatment with 4-(2-[7-amino-2-(2-furyl)[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethyl)phenol (ZM 241385), a selective adenosine A(2A) receptor antagonist. An intravenous injection of KF24345 at 48 h after the diet onset increased plasma adenosine concentrations in mice with acute pancreatitis. These results suggest that KF24345 shows anti-pancreatitis effects via endogenous adenosine and adenosine A(2A) receptors. The adenosine uptake inhibition could be a new therapeutic approach for acute pancreatitis.

Differential renal glomerular changes induced by 5/6 nephrectomization between common marmoset monkeys (Callithrix jacchus) and rats.

We have been investigating the relevance and availability of 5/6 nephrectomized (Nx) common marmoset monkeys (Callithrix jacchus) as a chronic renal failure model. As a part of this investigation, renal glomerular changes in the Nx marmosets were histopathologically and immunohistochemically evaluated, and then compared with those in 5/6 Nx SD rats. In the Nx marmosets, the blood and urine parameters were elevated, excluding urine protein; histopathologically, enlargement of Bowman's capsule and atrophy of the glomeruli were observed in all animals, and other slight changes were also observed in 1 or 2 marmosets. There were no significant changes in the mesangial matrix injury score, vimentin and desmin positivity or the number of WT1 positive cells between the control and Nx marmoset groups. On the other hand, in the Nx rats, the blood and urine parameters were elevated; histopathologically, various changes were observed in the glomeruli, and the mesangial matrix injury score, vimentin and desmin positivity were increased, while the number of WT1 positive cells was decreased; these histopathological impacts on the renal glomerulus at 13 weeks after Nx in rats were more severe than that in the Nx marmosets. Because the glomerular basement membrane (GBM) was much thicker in the marmosets than in the rats in electron microscopy, the weaker pathological changes in the Nx marmosets might be due to the GBM thickness. This study showed for the first time glomerular lesions developed in the Nx marmosets, and the possible pathogenesis of the glomerular lesions was discussed.

Histopathological, immunohistochemical and ultrastructural studies of a renal mesenchymal tumor in a young beagle dog.

A 15-month-old male beagle dog used in a toxicity study had a primary renal mesenchymal tumor. Macroscopically, the tumor was a gray-white mass which was found in the right kidney, and extended from the capsule to a position slightly compressing the medulla. Microscopically, most of the tumor cells showed a myxoid pattern, in which the matrix was positive for alcian blue staining. In the other parts of the tumor, a fascicular and wavy pattern was observed, and the matrix was full of collagen fibrils. Immunohistochemically, tumor cells were positive for vimentin and fibronectin, and negative for cytokeratin, desmin, α-smooth muscle actin, Von Willebrand factor, cyclooxigenase-2 and myelin basic protein. As a result, we diagnosed this case to be a renal mesenchymal tumor. Based on the microscopic findings, interstitial characteristics and immunohistochemical features, the present case was classified as a congenital mesoblastic tumor.

Verification analysis of thermoluminescent albedo neutron dosimetry at MOX fuel facilities.

Radiation workers engaging in the fabrication of MOX fuels at the Japan Atomic Energy Agency-Nuclear Fuel Cycle Engineering Laboratories are exposed to neutrons. Accordingly, thermoluminescent albedo dosemeters (TLADs) are used for individual neutron dosimetry. Because dose estimation using TLADs is susceptible to variation of the neutron energy spectrum, the authors have provided TLADs incorporating solid-state nuclear tracks detectors (SSNTDs) to selected workers who are routinely exposed to neutrons and have continued analysis of the relationship between the SSNTD and the TLAD (T/R(f)) over the past 6 y from 2004 to 2009. Consequently, the T/R(f) value in each year was less than the data during 1991-1993, although the neutron spectra had not changed since then. This decrease of the T/R(f) implies that the ratio of operation time nearby gloveboxes and the total work time has decreased.

Feasibility of in vivo measurement of 239 Pu distribution in lungs using an imaging plate.

An in vivo measurement system using an imaging plate (IP) system was developed, which displayed images reflecting (239)Pu distribution in the lung of a phantom. The detection limits of the IP system for 1-12h exposures were between 1670 and 245 Bq at a 1.6 cm chest wall thickness. The detection limit of the IP system for a 2.5h exposure was equal to that of a germanium detector for a 0.5h measurement. The IP system could be used as a new device for in vivo measurement of (239)Pu in the lung.

K858, a novel inhibitor of mitotic kinesin Eg5 and antitumor agent, induces cell death in cancer cells.

The aim of this study was to investigate the mechanism of inhibition of Eg5 (kinesin spindle protein), a mitotic kinesin that plays an essential role in establishing mitotic spindle bipolarity, by the novel small molecule inhibitor K858. K858 was selected in a phenotype-based forward chemical genetics screen as an antimitotic agent, and subsequently characterized as an inhibitor of Eg5. K858 blocked centrosome separation, activated the spindle checkpoint, and induced mitotic arrest in cells accompanied by the formation of monopolar spindles. Long-term continuous treatment of cancer cells with K858 resulted in antiproliferative effects through the induction of mitotic cell death, and polyploidization followed by senescence. In contrast, treatment of nontransformed cells with K858 resulted in mitotic slippage without cell death, and cell cycle arrest in G(1) phase in a tetraploid state. In contrast to paclitaxel, K858 did not induce the formation of micronuclei in either cancer or nontransformed cells, suggesting that K858 has minimal effects on abnormalities in the number and structure of chromosomes. K858 exhibited potent antitumor activity in xenograft models of cancer, and induced the accumulation of mitotic cells with monopolar spindles in tumor tissues. Importantly, K858, unlike antimicrotubule agents, had no effect on microtubule polymerization in cell-free and cell-based assays, and was not neurotoxic in a motor coordination test in mice. Taken together, the Eg5 inhibitor K858 represents an important compound for further investigation as a novel anticancer therapeutic.