Retinoic acid controls vascular formation by activating transcription of aryl hydrocarbon receptor gene in medakafish Oryzias latipes

Retinoic acid (RA) has been shown to have a role in vascular formation, but how it affects is not fully understood. Previously, we reported that RA and its nuclear receptor (RAR) is required for transcription of ahr1 encoding an aryl hydrocarbon receptor (AHR), and that pharmacological modulation of RA, RAR, and AHR impairs the formation of common cardinal veins (CCVs) on the yolk of medakafish embryos. Here, to delineate a role for ahr1 in the vascular formation, we used an antisense-ahr1 mRNA to suppress ahr1. Following the development of vegfr1-expressing angioblast cells, we show that the antisense-ahr1 greatly inhibited the accumulation of angioblasts at the prospective branchial arch (PBA) where CCVs begin to develop on the yolk and the following CCV formation, demonstrating for the first time the essential role of ahr1 in the embryonic vascular formation of vertebrates. We also show that rarα and ahr1 mRNAs are co-expressed at PBA, suggesting a possible role of the specific expression.This work was supported in part by a grant from the Ministry of Education, Science, Sports and Culture of Japan

Portal Venous Gas Following Ingestion of Hydrogen Peroxide Successfully Treated with Hyperbaric Oxygen Therapy

The primary toxicity of hydrogen peroxide results from its interaction with catalase, which liberates water and oxygen. We report the case of a 14-year-old Japanese girl with portal venous gas that was caused by oxygen liberated from intentionally ingested hydrogen peroxide. Although she had a past history of atrial septal defect, recovery without cardiac or neurological sequelae was achieved using hyperbaric oxygen therapy. Emergency physicians must be aware of the danger of liberated oxygen due to hydrogen peroxide ingestion

Maternal estrogen controls retinoic acid metabolism and signaling in early vertebrate development

Fertilized eggs of lower vertebrates contain substantial amounts of steroidal hormones such as estrogen transferred from mother during oogenesis. However, molecular roles for maternal estrogen in the early embryonic development are largely unknown. Here we show that maternal estrogen and estrogen receptor-α modulate retinoic acid (RA) metabolism and RA-responsive gene expression in medaka embryos. Treatments with excess estradiol, an anti-estrogen (tamoxifen), overexpression or knockdown of estrogen receptor-α (ERα) resulted in misregulation of RA-related gene expression such as raldh2 (retinalaldehyde dehydrogenase), cyp26a1 (RA hydroxylase), fgf8 (fibroblast growth factor), rarα (RA receptor-α), and ahr1 (aryl hydrocarbon receptor). We propose that maternal estrogen/ERα plays a critical role in the feedback control of in vivo level of RA and that it also activates RA signaling for the development of hindbrain and vasculatures. This is the first report demonstrating that maternal estrogen supports successful embryonic development by controlling RA metabolism and signaling in early vertebrate embryos.Supported by grants from the Ministry of Education, Culture, Sports, Science and Technology of Japan

バルーン下逆行性経静脈的塞栓術で治療した十二指腸静脈瘤の1例

十二指腸静脈瘤はまれであるが,致死的な出血を来す.近年,種々の治療法が行われている.肝硬変を有する46歳の男性が,重症の貧血のため入院した.血液検査ではヘマトクリット8.9%,血色素量2.3g/dlであった.内視鏡および造影CT検査により十二指腸水平脚に静脈瘤を認めた.第4病日にバルーン下逆行性経静脈的塞栓術を行い,治療に成功した.第4週の造影CT,MRIと内視鏡検査で十二指腸静脈瘤は消失していた.止血している十二指腸静脈瘤では,バルーン下逆行性経静脈的塞栓術が有効であると考えられた.Duodenal varices are a rare and fatal condition. Treatment options for duodenal varices have been more variety in recent years. A 46-year-old man with liver cirrhosis was admitted because of severe anemia. Laboratory findings showed extremely low values for hematocrit (8.9%) and hemoglobin (2.3 g/dl). Upon endoscopic examination and contrast-enhanced computed tomography, duodenal varices were evident on the third portion of the duodenum. On the 4th day, he was successfully treated by balloon-occluded retrograde transvenous obliteration (BRTO). Contrast-enhanced computed tomography, magnetic resonance imaging and endoscopy on the 4th week showed that the varices had diminished. In cases of duodenal varices when hemostasis, we support the use of BRTO

バルーン下逆行性経静脈的塞栓術で治療した十二指腸静脈瘤の1例

十二指腸静脈瘤はまれであるが,致死的な出血を来す.近年,種々の治療法が行われている.肝硬変を有する46歳の男性が,重症の貧血のため入院した.血液検査ではヘマトクリット8.9%,血色素量2.3g/dlであった.内視鏡および造影CT検査により十二指腸水平脚に静脈瘤を認めた.第4病日にバルーン下逆行性経静脈的塞栓術を行い,治療に成功した.第4週の造影CT,MRIと内視鏡検査で十二指腸静脈瘤は消失していた.止血している十二指腸静脈瘤では,バルーン下逆行性経静脈的塞栓術が有効であると考えられた.Duodenal varices are a rare and fatal condition. Treatment options for duodenal varices have been more variety in recent years. A 46-year-old man with liver cirrhosis was admitted because of severe anemia. Laboratory findings showed extremely low values for hematocrit (8.9%) and hemoglobin (2.3 g/dl). Upon endoscopic examination and contrast-enhanced computed tomography, duodenal varices were evident on the third portion of the duodenum. On the 4th day, he was successfully treated by balloon-occluded retrograde transvenous obliteration (BRTO). Contrast-enhanced computed tomography, magnetic resonance imaging and endoscopy on the 4th week showed that the varices had diminished. In cases of duodenal varices when hemostasis, we support the use of BRTO