A pediatric case of pancreaticobiliary maljunction demonstrated by endoscopic ultrasonography

AbstractPancreaticobiliary maljunction (PBM) is a congenital anomaly defined as a junction of the pancreatic and bile ducts located outside the duodenal wall, usually forming a markedly long common channel. Diagnosis of PBM in children is usually made by magnetic resonance cholangiopancreatography (MRCP) or endoscopic retrograde cholangiopancreatography (ERCP). Endoscopic ultrasonography (EUS) is a high-resolution imaging modality and a well-established diagnostic tool in adults with pancreaticobiliary (PB) disease. There are several articles which report the value of EUS in the diagnosis and evaluation of PBM in adults, but there are no reports of PBM demonstrated by EUS in children. Here, we present a case of PBM in a pediatric patient that was clearly demonstrated by EUS. EUS can be used as a second line examination modality for demonstrating PBM in pediatric patients in whom first line examinations, such as MRCP or ERCP, cannot be carried out or have not been conclusive

Increase of Pro-opiomelanocortin mRNA Prior to Tyrosinase, Tyrosinase-Related Protein 1, Dopachrome Tautomerase, Pmel-17/gp100, and P-Protein mRNA in Human Skin After Ultraviolet B Irradiation

In ultraviolet-induced tanning, the protein levels of various gene products critical for pigmentation (including tyrosinase and tyrosinase-related protein-1) are increased in response to ultraviolet B irradiation, but changes in mRNA levels of these factors have not been investigated in vivo. We have established an in situ hybridization technique to investigate mRNA levels of pro-opiomelanocortin, tyrosinase, tyrosinase-related protein-1, dopachrome tautomerase, P-protein, Pmel-17/gp100, and microphthalmia-associated transcription factor, and have analyzed the changes in mRNA levels in the ultraviolet B-exposed skin in vivo. The right or left forearm of each volunteer was irradiated with ultraviolet B, and skin biopsies were obtained at 2 and 5 d postirradiation. mRNA level of pro- opiomelanocortin was increased 2 d after ultraviolet B irradiation, and returned to a near-basal level after 5 d, whereas the mRNA levels of tyrosinase, tyrosinase-related protein-1, dopachrome tautomerase, P-protein, and Pmel-17/gp100 showed some or no increase at 2 d, but were significantly increased 5 d after ultraviolet B irradiation. Microphthalmia-associated transcription factor mRNA was slightly increased on days 2 and 5 after ultraviolet B irradiation. Our results suggest that the mechanism of the tanning response of human skin may involve the transcriptional regulation of certain pigmentary genes, and that pro-opiomelanocortin-derived melanocortins such as α-melanocyte-stimulating hormone and adrenocorticotropic hormone may play a part in regulating these genes in vivo

A Novel Serum-Free Monolayer Culture for Orderly Hematopoietic Differentiation of Human Pluripotent Cells via Mesodermal Progenitors

Elucidating the in vitro differentiation of human embryonic stem (ES) and induced pluripotent stem (iPS) cells is important for understanding both normal and pathological hematopoietic development in vivo. For this purpose, a robust and simple hematopoietic differentiation system that can faithfully trace in vivo hematopoiesis is necessary. In this study, we established a novel serum-free monolayer culture that can trace the in vivo hematopoietic pathway from ES/iPS cells to functional definitive blood cells via mesodermal progenitors. Stepwise tuning of exogenous cytokine cocktails induced the hematopoietic mesodermal progenitors via primitive streak cells. These progenitors were then differentiated into various cell lineages depending on the hematopoietic cytokines present. Moreover, single cell deposition assay revealed that common bipotential hemoangiogenic progenitors were induced in our culture. Our system provides a new, robust, and simple method for investigating the mechanisms of mesodermal and hematopoietic differentiation

PAX5 alterations in an infant case of KMT2A-rearranged leukemia with lineage switch

Lineage switch is a rare event at leukemic relapse. While mostly known to occur in KMT2A-rearranged infant leukemia, the underlying mechanism is yet to be depicted. This case report describes a female infant who achieved remission of KMT2A-MLLT3-rearranged acute monocytic leukemia, but 6 months thereafter, relapsed as KMT2A-MLLT3-rearranged acute lymphocytic leukemia. Whole exome sequencing of the bone marrow obtained pre-post lineage switch revealed two somatic mutations of PAX5 in the relapse sample. These two PAX5 alterations were suggested to be loss of function, thus to have played the driver role in the lineage switch from acute monocytic leukemia to acute lymphocytic leukemia

The first Japanese biobank of patient‐derived pediatric acute lymphoblastic leukemia xenograft models

A lack of practical resources in Japan has limited preclinical discovery and testing of therapies for pediatric relapsed and refractory acute lymphoblastic leukemia (ALL), which has poor outcomes. Here, we established 57 patient-derived xenografts (PDXs) in NOD.Cg-Prkdcscidll2rgtm1Sug/ShiJic (NOG) mice and created a biobank by preserving PDX cells including three extramedullary relapsed ALL PDXs. We demonstrated that our PDX mice and PDX cells mimicked the biological features of relapsed ALL and that PDX models reproduced treatment-mediated clonal selection. Our PDX biobank is a useful scientific resource for capturing drug sensitivity features of pediatric patients with ALL, providing an essential tool for the development of targeted therapies

In vitro expansion of CD34+CD38- cells under stimulation with hematopoietic growth factors on AGM-S3 cells in juvenile myelomonocytic leukemia

advance online publication, August 8, 2014 [Epub ahead of print]ArticleLEUKEMIA. 29(3):606-614 (2015)journal articl

Rituximab-combination chemotherapy achieves a 10th cycle of remission for Burkitt's lymphoma.

A 14-year-old girl with multiple intra-abdominal tumors was diagnosed with stage III Burkitt's lymphoma. She achieved complete remission after multi-drug chemotherapy, but she relapsed after six courses. Autologous peripheral blood stem cells (PBSC) or allogeneic PBSC harvested from an HLA-identical sibling were insufficient, and her family did not agree to bone marrow collection from the sibling. Although the patient relapsed nine times (the relapses involved intra-abdominal organs or bone) during the following 4 years 7 months, treatment with rituximab monotherapy or in combination with ifosphamide, carboplastin, and etoposide, or local irradiation (33.8-40.0 Gy) to treat the bone metastases, proved effective, resulting in complete or partial remission. At the time of writing, the patient was in a 10th cycle of remission lasting 1 year 6 months and had not required transplantation. Thus, a chemotherapy regimen including rituximab might be effective for Burkitt's lymphoma in patients experiencing multiple relapse