Recognition and pathological features of periampullary region adenocarcinoma with an indeterminable origin.

Determination of the primary tumor in periampullary region carcinomas can be difficult, and the pathological assessment and clinicopathological characteristics remain elusive. In this study, we investigated the current recognition and practices for periampullary region adenocarcinoma with an indeterminable origin among expert pathologists through a cognitive survey. Simultaneously, we analyzed a prospective collection of cases with an indeterminable primary tumor diagnosed from 2008 to 2018 to elucidate their clinicopathological features. All cases with pathological indeterminable primary tumors were reported and discussed in a clinicopathological conference to elucidate if it was possible to distinguish the primary tumor clinically and pathologically. From the cognitive survey, over 85% of the pathologists had experienced cases with indeterminable primary tumors; however, 70% of the cases was reported as pancreatic cancer without definitive grounds. Interpretation of the main tumor mass varied, and no standardized method was developed to determine the primary tumor. During a prospective study, 42 of the 392 periampullary carcinoma cases (10.7%) were considered as tumors with a pathological indeterminable origin. After the clinicopathological conferences, 21 (5.4%) remained indeterminable and were considered final indeterminable cases. Histological studies showed that the tumors spread along both the bile duct and main pancreatic duct; this was the most representative finding of the final indeterminable cases. This study is the first to elucidate and recognize the current clinicopathological features of periampullary region adenocarcinomas with an indeterminable origin. Adequate assessment of primary tumors in periampullary region carcinomas will help to optimize epidemiological data of pancreatic and bile duct cancer.

A morphometric study to establish criteria for fetal and neonatal cerebellar hypoplasia: A special emphasis on trisomy 18.

Cerebellar hypoplasia (CH) is one of the congenital abnormalities of the central nervous system and is seen in several diseases and syndromes. This study was conducted in order to examine methods for evaluating CH in fetus and neonate because CH has been diagnosed without any morphometric criteria at autopsy. We sampled 140 autopsied cases including nineteen trisomy 18 (T18), four non-T18 with presumed CH, and 117 control cases without any brain malformation. Statistical significance was present in the cerebellar weight and weight ratio of cerebellum per total brain between T18 and the control. The exponential regression models (ERM) showed that cerebral weight, cerebellar weight, and weight ratio of cerebellum per total brain increased gradually relative to gestational age in both T18 and the control. However, cerebellar weight and weight ratio of cerebellum per total brain of T18 showed growth delay with clear distinction between the two groups. The non-T18 with presumed CH showed similar results. Body weight, total brain, and gestational age should be considered totally when evaluating fetal and neonatal cerebellar development. Furthermore, the ERM results may be useful to evaluate the cerebellar development of fetus and neonate at autopsy.

A simple and robust method for establishing homogeneous mouse epiblast stem cell lines by wnt inhibition.

Epiblast stem cells (EpiSCs) are pluripotent stem cells derived from epiblasts of postimplantation mouse embryos, and thus provide a useful model for studying "primed" pluripotent states. Here, we devised a simple and robust technique to derive high-quality EpiSCs using an inhibitor of WNT secretion. Using this method, we readily established EpiSC lines with high efficiency and were able to use whole embryonic portions without having to separate the epiblast from the visceral endoderm (VE). Expression analyses revealed that these EpiSCs maintained a homogeneous, undifferentiated status, yet showed high potential for differentiation both in vitro and in teratomas. Unlike EpiSCs derived by the original protocol, new EpiSC lines required continuous treatment with the Wnt inhibitor, suggesting some intrinsic differences from the existing EpiSCs. The homogeneous properties of this new version of EpiSCs should facilitate studies on the establishment and maintenance of a "primed" pluripotent state, and directed differentiation from the primed state.

Development of SNP markers for C57BL/6N-derived mouse inbred strains.

C57BL/6N inbred mice are used as the genetic background for producing knockout mice in large-scale projects worldwide; however, the genetic divergence among C57BL/6N-derived substrains has not been verified. Here, we identified novel single nucleotide polymorphisms (SNPs) specific to the C57BL/6NJ strain and selected useful SNPs for the genetic monitoring of C57BL/6N-derived substrains. Informative SNPs were selected from the public SNP database at the Wellcome Trust Sanger Institute by comparing sequence data from C57BL/6NJ and C57BL/6J mice. A total of 1,361 candidate SNPs from the SNP database could distinguish the C57BL/6NJ strain from 12 other inbred strains. We confirmed 277 C57BL/6NJ-specific SNPs including 10 nonsynonymous SNPs by direct sequencing, and selected 100 useful SNPs that cover all of the chromosomes except Y. Genotyping of 11 C57BL/6N-derived substrains at these 100 SNP loci demonstrated genetic differences among the substrains. This information will be useful for accurate genetic monitoring of mouse strains with a C57BL/6N-derived background.

Establishment of successively transplantable rabbit VX2 cancer cells that express enhanced green fluorescent protein.

Morphological detection of cancer cells in the rabbit VX2 allograft transplantation model is often difficult in a certain region such as serosal cavity where reactive mesothelial cells mimic cancer cells and both cells share common markers such as cytokeratins. Therefore, tagging VX2 cells with a specific and sensitive marker that easily distinguishes them from other cells would be advantageous. Thus, we tried to establish a successively transplantable, enhanced green fluorescent protein (EGFP)-expressing VX2 model. Cancer cells obtained from a conventional VX2-bearing rabbit were cultured in vitro and transfected with an EGFP-encoding vector, and then successively transplanted in Healthy Japanese White rabbits (HJWRs) (n = 8). Besides, conventional VX2 cells were transplanted in other HJWRs (n = 8). Clinicopathological comparison analyses were performed between the two groups. The success rate of transplantation was 100% for both groups. The sensitivity and specificity of EGFP for immunohistochemical detection of VX2 cells were 84.3 and 100%, respectively. No significant differences in cancer cell morphology, tumor size (P = 0.742), Ki-67 labeling index (P = 0.878), or survival rate (P = 0.592) were observed between the two. VX2 cells can be genetically altered, visualized by EGFP, and successively transplanted without significant alteration of morphological and biological properties compared to those of the conventional model.

Unilateral glomerulocystic kidney disease associated with tuberous sclerosis complex in a neonate.

We report a case of glomerular cystic kidney disease (GCKD) associated with tuberous sclerosis complex (TSC) in a neonate. The patient displayed progressive abdominal enlargement attributed to GCKD associated with TSC. After birth, the right kidney was resected because it compressed his liver and right lung, and possible malignancy could not be excluded. Macroscopically, the resected kidney was markedly enlarged, and histologically the kidney had numerous glomerular cysts accompanied by papillary epithelial growth. Notably, a small area of normal parenchyma was observed at the lower pole. The epithelial cells of the cysts displaying a papillary growth pattern were positive for mTOR, phosphorylated mTOR, and phosphorylated S6 ribosomal protein (p-S6). The morphologically noncystic, normal-looking tubular epithelium was also positive for p-S6. These results imply that one more molecular event might be necessary for cyst formation in GCKD associated with TSC, in addition to the activation of mTOR signaling.

A novel method for isolating podocytes using magnetic activated cell sorting.

BACKGROUND: A large body of accumulated data has now revealed that podocytes play a major role in the development of proteinuria. However, the mechanisms of podocyte injury, leading to foot process effacement and proteinuria, are still unclear partly due to the current lack of an appropriate strategy for preparing podocytes. In this study, we have developed a novel method of rapid isolation of podocytes from mice using magnetic activated cell sorting with an anti-nephrin antibody. METHODS: After endothelial cell depletion using anti-CD31 antibody, nephrin-positive cells were prepared from mouse kidneys using magnetic activated cell sorting with polyclonal rabbit anti-nephrin antibody. Purity of the positively sorted cells was determined by confocal microscopy and fluorescence-activated cell sorting (FACS) analysis. Expression profiles of podocyte-specific molecules in the sorted fractions were characterized by qualitative PCR and immunoblot analysis. RESULTS: Nephrin-positive cells, isolated from mouse kidneys within 6 h, showed dual positivity for synaptopodin and rabbit IgG on confocal microscopy. FACS analysis revealed that the purity of the positively sorted fractions was ∼75%. The nephrin-positive cells sorted by this approach showed a significantly higher expression of podocyte-specific molecules compared with nephrin-negative fractions. CONCLUSIONS: These data strongly suggest that our novel method for isolating podocytes has great utility for various downstream applications such as genomic analysis, proteomics and transcriptomics to elucidate molecular profiling of podocyte biology in vivo compared with conventional methods as our approach requires only several hours to complete and no tissue culture.

The topoisomerase II alpha gene status in primary breast cancer is a predictive marker of the response to anthracycline-based neoadjuvant chemotherapy.

This study aimed at evaluating the usefulness of topoisomerase II alpha (TOP2A) for predicting the effect of anthracycline-based neoadjuvant chemotherapy in breast cancer. The TOP2A status was examined using fluorescent in situ hybridization (FISH) in 14 pre-chemotherapeutic breast cancer tissues, and was also assessed by immunohistochemistry (IHC) in 14 pairs of pre- and post-chemotherapeutic breast cancer specimens. TOP2A gene aberration by IHC tended to show a correlation with pathological responses but this was not statistically significant (p=0.060). On the other hand, the low TOP2A/CEP17 ratio correlated with good pathological responses (p=0.012). TOP2A overexpression was not significantly associated with response (p=0.580). Our results thus suggest that the TOP2A/CEP17 ratio may be a useful predictor of the effects of anthracycline-based neoadjuvant chemotherapy in breast cancer.

Hepatocellular carcinoma occurring in a young Crohn's disease patient.

Reported herein is a case of hepatocellular carcinoma (HCC) occurring in a 25-year-old Japanese man who was diagnosed with Crohn's disease (CD) at 14 years of age; treatment included predonisolone, azathioprine, and infliximab. The tumor was located in right upper lobe and the size was 8 cm in diameter; histology was poorly differentiated HCC with pleomorphic cellular changes. Adjacent normal liver showed no evidence of cirrhosis or viral hepatitis. Until now, only six cases of HCC arising in patients with CD have been reported in the English-language literature. Most of these patients had early onset of CD and HCC: none had cirrhosis or virus hepatitis. Most patients had a long disease history of CD and were being medicated with several immunosuppressive agents. Some factors associated with CD might indirectly or directly be related to the development of HCC in CD patients, although the possibility that these HCC occurred coincidentally in CD patients, including the present patient, cannot be ruled out. Accumulation of cases is necessary to evaluate the relationship between CD and HCC precisely.

[Case of lymphangiomyomatosis of the kidney and retroperitoneum].

We report a 44-year-old female with lymphangiomyomatosis (LAM) of the kidney and retroperitoneum. Abdominal ultrasonography revealed a right kidney tumor, and she was referred to our department. Computed tomography (CT) revealed a para-aortic phyma in addition to the tumor. We performed retroperitoneal tumorectomy and partial resection of the right kidney via laparotomy. Pathological findings suggested LAM. LAM usually induces pulmonary lesions and its prognosis is relatively unfavorable. Female hormones are considered to be involved in the aggravation of LAM. The lesion may not have reached the lung in this postmenopausal woman because of the absence of these hormones.

The mouse resources at the RIKEN BioResource center.

Mice are one of the most important model organisms for studying biological phenomena and diseases processes in life sciences. The biomedical research community has succeeded in launching large scale strategic knockout mouse projects around the world. RIKEN BRC, a comprehensive government funded biological resource center was established in 2001. RIKEN BRC has been acting as the core facility for the mouse resources of the National BioResource Project (NBRP) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan since 2002. RIKEN BRC is a founding member of the Federation of International Mouse Resources (FIMRe) together with the Jackson Laboratory, the European Mouse Mutant Archive, and other centers, and has participated in the International Mouse Strain Resource (IMSR) to distribute mouse strains worldwide. With the support of the scientific community, RIKEN BRC has collected over 3,800 strains including inbred, transgenic, knockout, wild-derived, and ENU-induced mutant strains. Excellent mouse models for human diseases and gene functions from academic organizations and private companies are distributed through RIKEN BRC. To meet research and social needs, our mice will be rederived to a specific pathogen-free state, strictly monitored for their health, and accurately tested for their genetic modifications and backgrounds. Users can easily access our mouse resources through the internet and obtain the mouse strains for a minimal fee. Cryopreservation of embryos and sperm is used for efficient preservation of the increasing number of mouse resources. RIKEN BRC collaborates with FIMRe members to support Japanese scientists in the use of valuable mouse resources from around the world.

Genetic differences among C57BL/6 substrains.

The C57BL/6 mouse is the most well-known inbred mouse strain, and has been widely used as a genetic background for congenic and mutant mice. A number of C57BL/6 substrains have been derived from the C57BL/6 founder line and are reported to differ in several phenotypes. There are several major sources of C57BL/6 substrains for the biomedical research community. The importance of their genetic and phenotypic differences among substrains, however, has not yet been well recognized by biomedical researchers. Here, we report the result of screening of the functional deletion of the nicotinamide nucleotide transhydrogenase (Nnt) gene and 1,446 SNPs genotyping among seven C57BL/6 substrains from different sources, such as C57BL/6J, C57BL/6JJcl, C57BL/6JJmsSlc, C57BL/6NJcl, C57BL/6NCrlCrlj, C57BL/6NTac, and C57BL/6CrSlc. The deletion of exon 7-11 in the Nnt gene that was previously reported in C57BL/6J was also observed in other C57BL/6J substrains, indicating that this functional deletion probably occurred at an early stage in the establishment of C57BL/6J substrains. The genotyping of SNP loci clearly demonstrate genetic differences between C57BL/6J and C57BL/6N substrains at 11 loci. Besides, we found another SNP differing between C57BL/6J and other C57BL/6J substrains available from commercial breeders. No genetic difference was detected among C57BL/6N substrains. The C57BL/6CrSlc mouse, originally derived from the National Cancer Institute of the NIH was found to be the same as the C57BL/6N substrains by the SNP pattern. These data will be useful for accurate genetic monitoring of genetically engineered mice with the C57BL/6 background.

Sebaceous carcinoma of the breast.

Sebaceous carcinoma (SC) of the breast is a rare malignant tumor and only nine cases, including the present one, have been reported in the English-language literature. The present report describes a case of mammary SC in a 50-year-old Japanese woman. The tumor was gray-white on cut surface and separate from the skin and the nipple. Microscopically, lobules encircled by a fibrous envelope and cords or small cell nests in the stroma were noted. These two types of structures were composed of dark cells and clear foamy cells. The dark cells had large nuclei and amphophilic cytoplasm. The clear foamy cells had numerous lipid vacuoles, confirmed on immunostaining with anti-adipophilin antibody and electron microscopy. In the lobules the gradual transitions from basal dark cells to central clear foamy cells and comedo-like necrosis were observed. The tumor cells were positive on immunohistochemistry for cytokeratins (CAM5.2, AE1/AE3), Her2/neu and androgen receptor but negative for estrogen and progesterone receptors. This is the first case of an androgen receptor-positive mammary SC to be reported, and therefore contributes to the understanding of the clinicopathological features of SC of the breast.