Robot therapy aids mental health in patients with hematological malignancy during hematopoietic stem cell transplantation in a protective isolation unit.

Patients with hematological malignancy experience physical and psychological pain, such as a sense of isolation and confinement due to intensive chemotherapy in a protective isolation unit (PIU). We examined whether the intervention of a robotic puppy, aibo (manufactured by Sony), could improve patients' mental health as an alternative therapy for pet therapy, which is not feasible in PIU. This study included 21 patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) (n = 16) or autologous HSCT (n = 5). The patients were randomly divided into the aibo and control groups. Psychological effects were regularly assessed by measuring the levels of salivary stress hormone chromogranin A (CgA), serum oxytocin, and serum cortisol and the quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR) scores. The aibo group demonstrated a significant decrease in CgA level, while the control group showed the opposite trend. In addition, changes in serum oxytocin and cortisol levels indicated that aibo helped reduce stress. There was no significant difference in the QIDS-SR scores between the two groups; however, the psychomotor activity in the aibo group improved significantly. These findings suggest that aibo intervention during a stay in a PIU can improve the mental health of patients with hematological malignancies who have undergone HSCT.

Development of a new, fully automated system for electron backscatter diffraction (EBSD)-based large volume three-dimensional microstructure mapping using serial sectioning by mechanical polishing, and its application to the analysis of special boundaries in 316L stainless steel.

We report the development of a fully automatic large-volume 3D electron backscatter diffraction (EBSD) system (ELAVO 3D), consisting of a scanning electron microscope (ZEISS crossbeam XB 1540) with a dedicated sample holder, an adapted polishing automaton (Saphir X-change, QATM), a collaborative robotic arm (Universal Robots UR5), and several in-house built devices. The whole system is orchestrated by an in-house designed software, which is also able to track the process and report errors. Except for the case of error, the system runs without any user interference. For the measurement of removal thickness, the samples are featured with markers put on the perpendicular lateral surface, cut by plasma focused ion beam (PFIB) milling. The individual effects of both 1 µm diamond suspension and oxide polishing suspension polishing were studied in detail. Coherent twin grain boundaries (GBs) were used as an internal standard to check the removal rates measured by the side markers. The two methods for Z-spacing measurements disagreed by about 10%, and the inaccurate calibration of the PFIB system was found to be the most probable reason for this discrepancy. The angular accuracy of the system was determined to be ∼2.5°, which can be significantly improved with more accurate Z-spacing measurements. When reconstructed grain boundary meshes are sufficiently smoothed, an angular resolution of ±4° is achieved. In a 3D EBSD dataset of a size of 587 × 476 × 72 µm3, we focused on the investigation of coincidence site lattice ∑9 GBs. While bearing predominantly a pure tilt character, ∑9 GBs can be categorized into three groups based on correlative 3D morphologies and crystallography.

Flumioxazin, a PPO inhibitor: A weight-of-evidence consideration of its mode of action as a developmental toxicant in the rat and its relevance to humans.

Flumioxazin, is a herbicide that has inhibitory activity on protoporphyrinogen oxidase (PPO), a key enzyme in the biosynthetic pathway for heme. Flumioxazin induces anemia and developmental toxicity in rats, including ventricular septal defect and embryofetal death. Studies to elucidate the mode of action (MOA) of flumioxazin as a developmental toxicant and to evaluate its relevance to humans have been undertaken. The MOA in the rat has now been elucidated. The first key event is PPO inhibition, which results in reduced heme synthesis in embryonic erythroblasts. The critical window for this effect is gestational day 12 when almost all erythroblasts are at the polychromatophilic stage, synthesizing heme very actively. Embryonic anemia/hypoxemia is induced and the heart pumps more strongly as a compensatory action during organogenesis, leading to thinning of the ventricular walls and failure of the interventricular septum to build completely and close. Investigations showed that this MOA is specific to rats and has no relevancy to humans. Flumioxazin inhibited PPO in rat hepatocyte mitochondria more strongly than in human. A 3-dimensional molecular simulation revealed that species differences in binding affinity of flumioxazin to PPO, observed previously in vitro, were due to differences in binding free energy. In vitro studies using several types of rat and human cells (erythroblasts derived from erythroleukemia cell lines, cord blood, or pluripotent stem cells), showed that flumioxazin decreased heme synthesis in rat cells but not in human cells, demonstrating a clear, qualitative species difference. Considering all available information, including data from PBPK modelling in rat and human, as well as the fact that anemia is not a symptom in patients with variegate porphyria, a congenital hereditary PPO defect, shows that the sequence of events leading to adverse effects in the rat embryo and fetus are very unlikely to occur in humans.

A simple three-dimensional gut model constructed in a restricted ductal microspace induces intestinal epithelial cell integrity and facilitates absorption assays.

The intestine acts as a center for nutrient and water absorption at the epithelium and plays an important role in immunity. Considering the complexity of its function and roles in living systems, a physiologically relevant gut in vitro model is desirable in both basic biology and the analysis of effects of some substances on functions of the gut; these analyses include the screening of drug and food candidates with regard to intestinal disorder at an early stage of medical development. In the present study, we constructed a three-dimensional (3D) gut model using human absorptive enterocytes (CACO-2 cells) by reconstitution of the gut epithelial sheet restricted on a high-reproducible ductal scaffold of collagen gel. Moreover, using the 3D gut model, we evaluated the morphology at the cellular and tissue levels and conducted a phenotypic analysis of the intestinal physiological functions, which involved a permeability assay mimicking barrier disruption inducing inflammation and an absorption assay reflecting ingestive effects. The ductal structure, in vivo-like 3D epithelial structures, epithelial barrier, and effective absorptive function characterized the 3D gut model. The epithelial cells formed a villus-like buckling epithelium, vertical microvilli of increased density on the cell surface, and a crypt-like localized cell proliferating region. The mature shape of the epithelium may contribute to mimicking barrier function and effective absorption compared with that in the 2D gut model. Furthermore, we successfully mimicked the dextran sodium sulfate-induced epithelial barrier dysfunction as a trigger phenomenon of gut inflammation in the 3D gut model. The integrity of the epithelium and phenotypic analysis of the intestinal physiological functions in the simple and reproducible 3D gut model will allow for a drug screening system for assessing the effects on the functions of the gut epithelium from the lumen side.

Cell proliferation analysis is a reliable predictor of lack of carcinogenicity: Case study using the pyrethroid imiprothrin on lung tumorigenesis in mice.

In the mouse carcinogenicity study, an apparent increase in lung adenocarcinoma was observed in male mice at 7000 ppm. Based on the overall evaluation of toxicology, oncology, pathology and statistics, we concluded that the apparent increase in lung tumors is not relevant for evaluation of carcinogenicity of imiprothrin (Regul Toxicol Pharmacol, 105, 1-14, 2019). To investigate whether imiprothrin has any mitogenic effect on mouse Club cells, the present study examined its effects on replicative DNA synthesis of Club cells and lung histopathology in male mice treated with imiprothrin for 7 days at 3500 and 7000 ppm in the diet. Isoniazid, a known mouse lung mitogen and tumor inducer, was also examined at 1000 ppm in the diet as a positive control of Club cell mitogenesis and morphological changes. Neither imiprothrin nor isoniazid caused any necrotic changes in lung by light or electron microscopy. There were no increases observed in the bromodeoxyuridine (BrdU) labeling index in the imiprothrin groups, while there was a statistically significant increase in the BrdU labeling index in the isoniazid group. These findings demonstrate that imiprothrin does not induce mouse Club cell proliferation or morphologic changes, supporting our previous conclusion described above. Thus, imiprothrin should not be classified as a carcinogen. Furthermore, this study indicates that short-term studies focusing on cell proliferation can be reliable for predicting a lack of carcinogenic potential of test chemicals.

Segmental aplasia of a uterine horn in two RccHan:WIST rats.

Aplasia of the uterine horn caused by developmental defects has been reported in several species but has not been reported in RccHan:WIST rats. We encountered spontaneous segmental aplasia of a right uterine horn in two RccHan:WIST rats and detailed its pathological characteristics. The right uterine horn of both rats had similar gross and histological appearances. At necropsy, there was segmental loss of the tissues corresponding to normal right uterine horn, which consisted of a fibrous band connected to the uterine cervix. A cystic structure with clear and colorless fluid was observed in the cranial segment of the right uterine horn close to the right oviduct. The cystic structure was thought to be a partially developed tissue to the right uterine horn. The cystic structure seemed to be derived from the right uterine horn. Histologically, a single layer of cuboidal epithelium lined the luminal surface of the cystic structure, the endometrium was thin, and no uterine glands were observed. The fibrous band was composed of α-SMA positive smooth muscle cells, connective tissue, and blood vessels, but cytokeratin AE1/AE3 positive epithelium and uterine endometrium were absent. Based on these gross findings and histological features, segmental aplasia of a uterine horn was diagnosed. To our knowledge, these cases of segmental aplasia of a uterine horn are the first ones described in RccHan:WIST rats.

Toxicological evaluation of carcinogenicity of the pyrethroid imiprothrin in rats and mice.

The carcinogenic potential of a non-genotoxic pyrethroid imiprothrin was examined in rats and mice. There was no carcinogenicity in rats up to a maximum dose of 5000 ppm of the diet. There was a higher (p = 0.03) incidence of lung adenocarcinomas at 7000 ppm in males, and females showed an increasing (p < 0.01) trend in the incidence of lung adenomas and combined lung adenoma/adenocarcinomas. Additional step sections of lung demonstrated no significant increases in any tumor at p < 0.05, although an increasing trend with dose was observed among females. We argue that, the 7000 ppm dose exceeded the Maximum Tolerated Dose (MTD) for both sexes, based on systemic toxicity as evidenced by body weight gain reduction (both sexes) and high mortality (females). If the 7000 ppm dose is therefore removed from consideration, there are not significant (p < 0.05) increases in tumor formation. Moreover, a consideration of multiple comparisons reveals that the lung tumor increases observed are totally consistent with what would be expected by chance alone. Based on high susceptibility of this mouse strain for the appearance of lung tumors and the lack of a statistically significant increase in tumors by appropriate analysis, the mouse study does not indicate a carcinogenic effect of imiprothrin, and thus no classification for carcinogenicity is warranted.

Involvement of Peroxisome Proliferator-Activated Receptor-Alpha in Liver Tumor Production by Permethrin in the Female Mouse.

The nongenotoxic pyrethroid insecticide permethrin produced hepatocellular tumors in CD-1 mice but not in Wistar rats. Recently, based on findings of a Pathology Working Group involving an expert panel of pathologists, it was concluded that permethrin increased liver tumors at 2500 and 5000 ppm in female mice, but no treatment-related tumorigenic response occurred in male mice at dose levels examined in the 2-year bioassay. To evaluate a possible mode of action (MOA) for the permethrin female CD-1 mouse hepatocellular tumors, a number of investigative studies were conducted. In time-course studies in female CD-1 mice, permethrin increased relative liver weight and enhanced hepatocyte proliferation within 1 week. Treatment with permethrin resulted in marked increases in CYP4A enzyme activities and mRNA levels, but only slightly increased CYP2B markers, suggesting that permethrin primarily activates the peroxisome proliferator-activated receptor alpha (PPARα) and to a much lesser extent the constitutive androstane receptor. The effects of permethrin on relative liver weight, hepatocyte proliferation and CYP4A enzyme activities and mRNA levels were dose-dependent and were reversible within 5 weeks after cessation of treatment. The hepatic effects of permethrin observed in wild-type female mice were markedly reduced in PPARα knockout female mice. These results demonstrate that the MOA for hepatocellular tumor formation by permethrin in female mice involves activation of PPARα resulting in a mitogenic effect. The MOA for permethrin-induced mouse liver tumor formation due to PPARα activation is considered to be not plausible for humans. This conclusion is strongly supported by available epidemiological data for permethrin.

Effectiveness of plasma lyso-Gb3 as a biomarker for selecting high-risk patients with Fabry disease from multispecialty clinics for genetic analysis.

PURPOSE: Plasma globotriaosylsphingosine (lyso-Gb3) is a promising secondary screening biomarker for Fabry disease. Here, we examined its applicability as a primary screening biomarker for classic and late-onset Fabry disease in males and females. METHODS: Between 1 July 2014 and 31 December 2015, we screened 2,359 patients (1,324 males) referred from 168 Japanese specialty clinics (cardiology, nephrology, neurology, and pediatrics), based on clinical symptoms suggestive of Fabry disease. We used the plasma lyso-Gb3 concentration, α-galactosidase A (α-Gal A) activity, and analysis of the α-Gal A gene (GLA) for primary and secondary screens, respectively. RESULTS: Of 8 males with elevated lyso-Gb3 levels (≥2.0 ng ml-1) and low α-Gal A activity (≤4.0 nmol h-1 ml-1), 7 presented a GLA mutation (2 classic and 5 late-onset). Of 14 females with elevated lyso-Gb3, 7 displayed low α-Gal A activity (5 with GLA mutations; 4 classic and 1 late-onset) and 7 exhibited normal α-Gal A activity (1 with a classic GLA mutation and 3 with genetic variants of uncertain significance). CONCLUSION: Plasma lyso-Gb3 is a potential primary screening biomarker for classic and late-onset Fabry disease probands.

An Evaluation of the Human Relevance of the Lung Tumors Observed in Female Mice Treated With Permethrin Based on Mode of Action.

Permethrin increased the incidence of bronchiolo-alveolar adenomas in female mice but not male mice or female or male rats. Studies were conducted to determine whether permethrin has mitogenic activity in Club cells in mouse lung as the basis for the mode of action (MOA) for the lung adenoma induction. Several short-term experiments focusing on time-course, dose-response, reversibility, sex difference, strain difference, and species difference were evaluated for Club cell proliferation and morphology. The findings demonstrated that permethrin slightly and continuously enhanced Club cell proliferation at tumor-associated dose levels in female mice, but did not increase proliferation in male mice or in female rats. Electron microscopic examination demonstrated that permethrin produced morphological alterations in Club cells prior to increasing the Club cell proliferation. There was no evidence of increased cell death. These alterations in Club cells were also observed with a close structural analog cypermethrin. Taken together, the present studies provide evidence that the MOA for induction of mouse lung adenomas by permethrin involves slight morphological effects on Club cells, sustained Club cell proliferation, and eventually hyperplasia and bronchiolo-alveolar adenoma in susceptible mice. The potential human carcinogenic hazard of permethrin based on the tumorigenic MOA for lung tumors in mice was evaluated using the International Programme on Chemical Safety Human Relevance Framework. As humans are quantitatively much less sensitive to agents that increase Club cell proliferation and tumor formation in mice, it is not likely permethrin will lead to an increase in susceptibility to lung tumor development in humans. Epidemiological data for permethrin strongly supports this conclusion.

Optimal dose selection of N-methyl-N-nitrosourea for the rat comet assay to evaluate DNA damage in organs with different susceptibility to cytotoxicity.

The in vivo rodent alkaline comet assay (comet assay) is a promising technique to evaluate DNA damage in vivo. However, there is no agreement on a method to evaluate DNA damage in organs where cytotoxicity is observed. As a part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the comet assay, we examined DNA damage in the liver, stomach, and bone marrow of rats given three oral doses of N-methyl-N-nitrosourea (MNU) up to the maximum tolerated dose based on systemic toxicity. MNU significantly increased the % tail DNA in all the organs. Histopathological analysis showed no cytotoxic effect on the liver, indicating clearly that MNU has a genotoxic potential in the liver. In the stomach, however, the cytotoxic effects were very severe at systemically non-toxic doses. Low-dose MNU significantly increased the % tail DNA even at a non-cytotoxic dose, indicating that MNU has a genotoxic potential also in the stomach. Part of the DNA damage at cytotoxic doses was considered to be a secondary effect of severe cell damage. In the bone marrow, both the % tail DNA and incidence of micronucleated polychromatic erythrocytes significantly increased at non-hematotoxic doses, which were different from the non-cytotoxic doses for liver and stomach. These findings indicate that an optimal dose for detecting DNA damage may vary among organs and that careful attention is required to select an optimum dose for the comet assay based on systemic toxicity such as mortality and clinical observations. The present study shows that when serious cytotoxicity is suggested by increased % hedgehogs in the comet assay, histopathological examination should be included for the evaluation of a positive response.

Genotoxicity evaluation of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate using a combined rat comet/micronucleus assays.

As a part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo alkaline comet assay (comet assay), we examined DNA damage in the liver, stomach, and bone marrow of rats dosed orally three times with up to 2000 mg/kg of benzene, di(2-ethylhexyl) phthalate, and trisodium ethylenediamine tetraacetic acid monohydrate. All three compounds gave negative results in the liver and stomach. In addition, a bone marrow comet and micronucleus analysis revealed that benzene, but not di(2-ethylhexyl) phthalate or trisodium ethylenediamine tetraacetic acid monohydrate induced a significant increase in the median % tail DNA and micronucleated polychromatic erythrocytes, compared with the respective concurrent vehicle control. These results were in good agreement with the previously reported genotoxicity findings for each compound. The present study has shown that combining the micronucleus test with the comet assay and carrying out these analyses simultaneously is effective in clarifying the mechanism of action of genotoxic compounds such as benzene.

Effect of collaborative intervention by medical and dental professionals on adherence to smoking abstinence.

The need for smoking cessation care is widely recognized. It is, however, difficult to achieve continued smoking abstinence, even when cessation has initially been achieved. The aim of this study was to determine the effectiveness of a collaborative smoking cessation program involving both medical and dental professionals on smoking abstinence. A total of 10 patients visiting our Smoking Cessation Outpatient Clinic were followed up and monitored for smoking abstinence. All received smoking cessation care consisting mainly of counseling by dental and medical professionals and pharmacotherapy. They also concurrently received an oral examination, instruction on oral hygiene, and professional tooth cleaning. The 4-week smoking abstinence rate was 90.0% on completion of the program. One patient failed to complete the program. At one month after the program, 8 out of 9 patients remained abstinent (4-month abstinence; 88.9%). At 3 months after the program, 7 patients remained abstinent (6-month abstinence; 77.8%). Follow-up was impossible in one patient. Within the limitations of the present study, it is suggested that such collaborative intervention including subsequent dental care has the potential to promote short-term adherence to smoking abstinence.

Effect of Ala replacement with Aib in amphipathic cell-penetrating peptide on oligonucleotide delivery into cells.

A number of cell-penetrating peptides (CPPs) have been characterized and their usefulness as delivery tools has been clarified. As one of the CPPs, model amphipathic peptide (MAP) was developed by integrating both hydrophobic and hydrophilic amino acids in its sequence. In our previous work, we designed MAP(Aib) by replacing five alanine (Ala) residues on the hydrophobic face of the helix in the MAP sequence with α-aminoisobutyric acid (Aib) residues, and the replacement resulted in higher helix propensity, stronger resistance to protease, and higher cell membrane permeability than MAP. As a next step, we examined the efficiency of oligonucleotide (ODN) delivery into cells by MAP(Aib) in comparison with that by MAP. The electrostatically formed MAP(Aib)/ODN complex was more easily taken up by cells than the MAP/ODN complex, and the ODN delivery by MAP(Aib) was via an endocytic pathway. We demonstrated that the incorporation of Aib residues into CPPs enhances the delivery of hydrophilic molecules, such as ODN, into cells.

Twenty-one proteins up-regulated in human H-ras oncogene transgenic rat pancreas cancers are up-regulated in human pancreas cancer.

OBJECTIVES: We have established rat models of pancreatic ductal adenocarcinoma (PDAC) in which expression of a human H-ras(G12V) or K-ras(G12V) oncogene regulated by the Cre/lox system drives pancreatic carcinogenesis. Pancreatic ductal adenocarcinoma which develops in H-ras(G12V) and K-ras(G12V) transgenic rats is cytogenetically and histopathologically similar to human PDAC. The present study was designed to determine the feasibility of using the commercially available H-ras(G12V) transgenic rat to find diagnostic protein biomarkers for human pancreatic cancer. METHODS: For an animal model to be useful for searching for protein biomarkers for a disease, it is essential that proteins that are up-regulated in the model are also up-regulated in humans. We used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to compare H-ras(G12V) transgenic rat PDAC with surrounding normal pancreas tissue. RESULTS: We identified 30 up-regulated proteins in the H-ras(G12V) transgenic rat PDAC lesions; importantly, 21 human homologs of these 30 rat proteins are up-regulated in human pancreatic cancer patients. CONCLUSIONS: These results indicate that numerous proteins that are up-regulated in H-ras(G12V) transgenic rat PDAC are also up-regulated in human pancreatic cancer; therefore, this rat model can be used to search for diagnostic biomarkers for this disease.

Successful treatment of protein-losing gastroenteropathy with steroid pulse and immunosuppressive therapies in a patient with sjögren syndrome.

We report the case of a 59-year-old female who developed facial edema together with hypoproteinemia. On the basis of (99m)Tc-human serum albumin scintigraphy and a1-antitrypsin clearance, she was diagnosed with protein-losing gastroenteropathy. Furthermore, she was diagnosed with Sjögren syndrome on the basis of eye and oral dryness, positive result with anti-SSA antibody, and salivary gland biopsy. Her symptoms improved with the use of immunosuppressive agents following steroid pulse therapy. Therefore, steroid pulse therapy and immunosuppressive agents should be considered as possible effective treatment strategies for protein-losing gastroenteropathy associated with autoimmune diseases.

Well-differentiated teratoma in a mouse uterus.

Teratomas commonly occur in the testis and ovary, whereas in the uterus they are rare. The authors report findings for a mass detected in the uterus of a 26-week-old mouse in a colony of C57BL/6 bred in their laboratory. The mass was located in the endometrium and protruded into the lumen. Histopathologically, it consisted of abnormal diploblastic or triploblastic tissues. Bone with a growth plate and myeloid cells, as well as cartilage, was mainly observed. It also included melanocytes, exocrine gland-like cells, striated muscle, and neuron-like cells. While these tissues were accompanied by extensive necrosis, all of them were well differentiated and lacked features of malignancy, such as invasion and metastasis. This mouse had experienced parturition, but fetal tissue was not observed in the lesion. Therefore, the lesion was diagnosed as a benign teratoma, which was spontaneously developed in the uterus.

Circulating microRNAs, possible indicators of progress of rat hepatocarcinogenesis from early stages.

MicroRNAs (miRNAs), a class of small noncoding RNAs that regulate gene expression at the posttranscriptional level, are believed promising biomarkers for several diseases as well as a novel target of drugs, including cancer. In particular, miRNAs might allow detection of early stages of carcinogenesis. The present study was conducted to provide concrete evidence using chemical-induced hepatocarcinogenesis in rat as a model. We thereby observed aberrant fluctuation of circulating miRNAs in the serum of rats not only with neoplastic lesions such as hepatocellular adenoma (HCA) and hepatocellular carcinoma (HCC), but also with preneoplastic lesions, such as foci of hepatocellular alteration (FHA). Additional qRT-PCR analysis revealed gradual elevation of some circulating miRNAs (i.e., let-7a, let-7f, miR-34a, miR-98, miR-331, miR-338 and miR-652) with progress of hepatocarcinogenesis. Interestingly, increased levels of let-7a, let-7f and miR-98 were statistically significant even in the serum of rats at very early stages. These findings provide the first evidences that circulating miRNAs have the potential to predict carcinogenesis at earlier stages, preneoplastic lesions than with previous biomarkers and that they might be utilized to monitor the progress of tumor development.

Ethanol Does Not Promote MeIQx-initiated Rat Colon Carcinogenesis Based on Evidence from Analysis of a Colon Cancer Surrogate Marker.

Epidemiological studies suggest that alcohol consumption increases the risk of developing colorectal cancer. However, the data are confounded by numerous cosegregating variables. To cast further light on the relationships between alcohol intake and colon cancer development, 21-day-old male F344/DuCrj rats were fed 200 ppm 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) in their diet for 8 weeks and doses of 0, 0.1, 0.3, 1, 3, 10 and 20% of ethanol in their drinking water ad libitum for 16 weeks thereafter. The rats were sacrificed after 24 weeks of experiment, and aberrant crypt foci (ACF), surrogate lesions for colon cancer, were examined under a light microscope at low magnification. Ethanol was found not to affect the ACF formation at any dose compared with the initiated-controls. Furthermore, ethanol did not alter colon epithelial cell proliferation. These data, obtained by analysis of a colon cancer surrogate marker lesion, indicate that ethanol lacks promotion activity for MeIQx-initiated rat colon carcinogenesis.

Spontaneous iron accumulation in hepatocytes of a 7-week-old female rat.

Spontaneous iron accumulation in hepatocytes was observed in a 7-week-old female Han Wistar GALAS rat. Very fine yellowish brown pigments, which showed a positive reaction with Berlin Blue stain, were apparent in the cytoplasm close to the bile canaliculi, with a diminishing periportal-to-centrilobular gradient. There were also differences in distribution between and within lobes. Transmission electron microscopy revealed cytosolic ferritin and pericanalicular siderosomes in hepatocytes. No degeneration or necrotic changes were observed, and non-hepatocyte cells did not demonstrate any obvious accumulation of iron. There were no abnormalities in the animal other than this finding in the liver.