89 research outputs found

    Toxicological Pathology in the Rat Placenta

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    The placenta grows rapidly for a short period with high blood flow during pregnancy and has multifaceted functions, such as its barrier function, nutritional transport, drug metabolizing activity and endocrine action. Consequently, the placenta is a highly susceptible target organ for drug- or chemical-induced adverse effects, and many placenta-toxic agents have been reported. However, histopathological examination of the placenta is not generally performed, and the placental toxicity index is only the placental weight change in rat reproductive toxicity studies. The placental cells originate from the trophectoderm of the embryo and the endometrium of the dam, proliferate and differentiate into a variety of tissues with interaction each other according to the development sequence, resulting in formation of a placenta. Therefore, drug- or chemical-induced placental lesions show various histopathological features depending on the toxicants and the exposure period, and the pathogenesis of placental toxicity is complicated. Placental weight assessment appears not to be enough to evaluate placental toxicity, and reproductive toxicity studies should pay more attention to histopathological evaluation of placental tissue. The detailed histopathological approaches to investigation of the pathogenesis of placental toxicity are considered to provide an important tool for understanding the mechanism of teratogenicity and developmental toxicity with embryo lethality, and could benefit reproductive toxicity studies

    Carcinogen-induced Thyroid Proliferative Lesions in Wistar Hannover GALAS Rats with Thyroid Dysplasia

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    Incidences and morphological features of thyroid proliferative lesions induced by carcinogens in Wistar Hannover GALAS rats (GALAS rats) showing normal growth with or without thyroid dysplasia were examined. All thyroid tissue samples were obtained from our recently conducted study using male GALAS rats treated with 5 carcinogens according to the medium-term multiorgan carcinogenicity bioassay protocol (called DMBDD treatment). In the DMBDD-treated rats, thyroid dysplasia was found in 9 out of 114 rats. Follicular cell adenomas were found in 5 out of 9 rats with thyroid dysplasia and in 7 out of 105 rats without thyroid dysplasia. The incidence of adenoma was significantly increased in rats with thyroid dysplasia (55.6%) compared with that in rats without thyroid dysplasia (6.7%). Adenomas in rats with thyroid dysplasia were observed as single or multiple nodules, well demarcated and composed of variously sized vacuolated cells or unvacuolated cells. These histopathological features and staining profiles of luminal colloid for PAS and thyroglobulin, together with PCNA-positive cells, were fundamentally similar to those of rats without thyroid dysplasia. On the other hand, the luminal colloid in adenomas of rats with thyroid dysplasia had a tendency to be poorly stained for T4 compared with that of rats without thyroid dysplasia. From these findings, it appears that dysplastic thyroids of rats showing normal growth are more sensitive to carcinogens than normal thyroids. In addition, the morphological features of carcinogen-induced thyroid proliferative lesions in GALAS rats with thyroid dysplasia were fundamentally similar to those of rats without thyroid dysplasia, except for the vacuoles and T4 staining profile

    Ulnar nerve palsy associated with closed midshaft forearm fractures

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    Ulnar nerve palsy is a rare complication of closed midshaft forearm fractures; only 8 cases have been reported. This article describes a case of ulnar nerve palsy associated with a midshaft forearm fracture. A 12-year-old girl sustained a right midshaft forearm fracture. Whether she had a peripheral nerve injury was unknown due to strong pain. She underwent emergency manual reduction and intramedullary pinning. However, ulnar nerve palsy was remarkable postoperatively and gradually worsened. Therefore, neurolysis was performed 9 weeks later. The nerve had adhered to surrounding scar tissue. Six months after a second surgery, she had no motor dysfunction. The pathogenesis of ulnar nerve palsy complicated with midshaft forearm fractures varies and may be the result of direct contusion, direct damage by a bony spike, bony entrapment after closed reduction, and entrapment by a scar. In the current case, the patient was uncooperative at initial examination. Therefore, it is unknown whether she presented with immediate ulnar nerve palsy after the fracture. However, the ulnar nerve was not entrapped at the fracture site, and the surrounding muscle was intact but adhered to the surrounding scar tissue. The etiology of this case was considered to be entrapment by scar formation. According to a literature search, the authors recommend exploring the nerve approximately 8 to 10 weeks after primary surgery, after which neurological symptoms do not tend to improve

    Prospective Study of the Effect of the 21-Gene Assay on Adjuvant Clinical Decision-Making in Japanese Women With Estrogen Receptor-Positive, Node-Negative, and Node-Positive Breast Cancer

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    AbstractBackgroundIn this study we investigated if the 21-gene assay result affects adjuvant decision-making in Japanese women with ER+ invasive EBC.Patients and MethodsA total of 124 consecutive eligible patients with ER+, HER2-negative EBC and 0 to 3 positive lymph nodes were enrolled. Treatment recommendations, physicians' confidence and patients' decisional conflict before and after knowledge of the Recurrence Score results of the 21-gene assay were recorded.ResultsOne-hundred four patients (84%) had N0 disease, including micrometastases, and 20 (16%) had N+ disease. Overall, recommendations changed in 33% (95% CI, 24%-43%) of N0 and 65% (95% CI, 41%-85%) of N+ patients. In 27 of 48 (56%) of N0 and 13 of 15 (87%) of N+ patients an initial recommendation for chemohormonal therapy was revised to only hormonal therapy after assay results, and in 7 of 56 (13%) of N0 and 0 of 5 N+ patients from only hormonal to combined chemohormonal therapy. Decisions appeared to follow the Recurrence Score results for low and high values. For patients with intermediate Recurrence Score values, overall recommendations for chemohormonal treatment tended to decrease after assay results. Physicians' confidence increased in 106 of 124 (85.5%; 95% CI, 78%-91%) cases. Patients' decisional conflict significantly improved as indicated by changes in the total score and the 5 defined subscores (P = .014 for Informed Subscore; P < .001 for all others).ConclusionResults from this prospective study in a Japanese population confirm an effect of the 21-gene assay results on adjuvant treatment decision-making, consistent with reported experiences from the United States and Europe

    Ultra fast quantum key distribution over a 97 km installed telecom fiber with wavelength-division multiplexing clock synchronization

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    We demonstrated ultra fast BB84 quantum key distribution (QKD) transmission at 625 MHz clock rate through a 97 km field-installed fiber using practical clock synchronization based on wavelength-division multiplexing (WDM). We succeeded in over-one-hour stable key generation at a high sifted key rate of 2.4 kbps and a low quantum bit error rate (QBER) of 2.9%. The asymptotic secure key rate was estimated to be 0.78-0.82 kbps from the transmission data with the decoy method of average photon numbers 0, 0.15, and 0.4 photons/pulse.Comment: 7 pages, 3 figures, v2 : We added a comment on the significance of our work, some minor corrections, and reference

    Objective evaluation of cerebrovascular reactivity for acetazolamide predicts cerebral hyperperfusion after carotid artery stenting: Comparison with region of interest methods

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    金沢大学附属病院脳神経外科Background and purpose: Hemodynamic impairments are considered risk factors of cerebral hyperperfusion after carotid artery stenting (CAS); measurement by Single-photon emission computed tomography (SPECT) using a subjective region of interest (ROI) method lacks consistency and reproducibility. Materials and methods: The present study compared objective perfusion analysis (stereotactic extraction estimation [SEE] method) with the ROI method for preoperative SPECT to predict the hyperperfusion phenomenon (HPP) after CAS. Preoperative resting asymmetry index (cerebral blood flow [CBF] ratio from the affected to unaffected hemisphere) and cerebrovascular reactivity (CVR) to acetazolamide were measured by N-isopropyl-p-[123I]-iodoamphetamine SPECT using the SEE and ROI method in 84 patients. CBF was also measured the day after CAS. Perfusion data with the highest area under the curve (AUC) by receiver-operating characteristic (ROC) analysis was considered a perfusion risk factor of HPP. Multivariate analyses for clinical characteristics and perfusion risk factors were performed to determine predictors of HPP. Results: The HPP was observed in 10 patients (11.9%). Female sex, contralateral stenosis, and degree of stenosis were significantly associated with HPP development on univariate analysis, and symptomatic stenosis was not found to be a significant factor. On SPECT analysis, CVR in the MCA area by SEE method had the highest AUC (0.981). Multivariate analysis showed that CVR in the MCA area was a significant predictor of HPP (P = 0.041). To predict hyperperfusion, the ROC curve of the CVR showed a cutoff value of –0.60%, sensitivity of 94.6%, and specificity of 100% (P < 0.001). Conclusions: Objective SEE method had better a predictive capability than ROI method to identify risk of hyperperfusion after CAS. © 2018 Elsevier Masson SASEmbargo Period 12 month

    Hepatitis B virus strains of subgenotype A2 with an identical sequence spreading rapidly from the capital region to all over Japan in patients with acute hepatitis B

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    ObjectiveTo examine recent trends of acute infection with hepatitis B virus (HBV) in Japan by nationwide surveillance and phylogenetic analyses.MethodsDuring 1991 through 2009, a sentinel surveillance was conducted in 28 national hospitals in a prospective cohort study. Genotypes of HBV were determined in 547 patients with acute hepatitis B. Nucleotide sequences in the preS1/S2/S gene of genotype A and B isolates were determined for phylogenetic analyses.ResultsHBV genotype A was detected in 137 (25% (accompanied by genotype G in one)) patients, B in 48 (9%), C in 359 (66%), and other genotypes in the remaining three (0.5%). HBV persisted in five with genotype A including the one accompanied by genotype G; another was co-infected with HIV type 1. The genotype was A in 4.8% of patients during 1991-1996, 29.3% during 1997-2002, and 50.0% during 2003-2008 in the capital region, as against 6.5%, 8.5% and 33.1%, respectively, in other regions. Of the 114 genotype A isolates, 13 (11.4%) were subgenotype A1, and 101 (88.6%) were A2, whereas of the 43 genotype B isolates, 10 (23.3%) were subgenotype B1, 28 (65.1%) were B2, two (4.7%) were B3, and three (7.0%) were B4. Sequences of 65 (64%) isolates of A2 were identical, as were three (23%) of A1, and five (18%) of B2, but none of the B1, B3 and B4 isolates shared a sequence.ConclusionsAcute infection with HBV of genotype A, subgenotype A2 in particular, appear to be increasing, mainly through sexual contact, and spreading from the capital region to other regions in Japan nationwide. Infection persisted in 4% of the patients with genotype A, and HBV strains with an identical sequence prevailed in subgenotype A2 infections. This study indicates the need for universal vaccination of young people to prevent increases in HBV infection in Japan

    Early In Vitro Differentiation of Mouse Definitive Endoderm Is Not Correlated with Progressive Maturation of Nuclear DNA Methylation Patterns

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    The genome organization in pluripotent cells undergoing the first steps of differentiation is highly relevant to the reprogramming process in differentiation. Considering this fact, chromatin texture patterns that identify cells at the very early stage of lineage commitment could serve as valuable tools in the selection of optimal cell phenotypes for regenerative medicine applications. Here we report on the first-time use of high-resolution three-dimensional fluorescence imaging and comprehensive topological cell-by-cell analyses with a novel image-cytometrical approach towards the identification of in situ global nuclear DNA methylation patterns in early endodermal differentiation of mouse ES cells (up to day 6), and the correlations of these patterns with a set of putative markers for pluripotency and endodermal commitment, and the epithelial and mesenchymal character of cells. Utilizing this in vitro cell system as a model for assessing the relationship between differentiation and nuclear DNA methylation patterns, we found that differentiating cell populations display an increasing number of cells with a gain in DNA methylation load: first within their euchromatin, then extending into heterochromatic areas of the nucleus, which also results in significant changes of methylcytosine/global DNA codistribution patterns. We were also able to co-visualize and quantify the concomitant stochastic marker expression on a per-cell basis, for which we did not measure any correlation to methylcytosine loads or distribution patterns. We observe that the progression of global DNA methylation is not correlated with the standard transcription factors associated with endodermal development. Further studies are needed to determine whether the progression of global methylation could represent a useful signature of cellular differentiation. This concept of tracking epigenetic progression may prove useful in the selection of cell phenotypes for future regenerative medicine applications
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