Extracellular domain of CD98hc is required for early murine development

<p>Abstract</p> <p>Background</p> <p>The multifunctional protein CD98 heavy chain (CD98hc, Slc3a2) associates with integrin β1 through its cytoplasmic and transmembrane domains and the CD98hc-mediated integrin signaling is required for maintenance of ES cell proliferation. CD98hc-null mice exhibit early post-implantation lethality similar to integrin β1-null mice, supporting the importance of its interaction with integrin β1. On the other hand, the extracellular domain of CD98hc interacts with L-type amino acid transporters (LATs) and is essential for appropriate cell surface distribution of LATs. LATs mediate the transport of amino acids and other molecules such as thyroid hormone. In this respect, CD98hc may also affect development via these transporters.</p> <p>Results</p> <p>In this study, mice were generated from embryonic stem (ES) cell line (PST080) harboring a mutant CD98hc allele (CD98hc^Δ/+). Expression of the CD98hc mutant allele results in ΔCD98hc-β geo fusion protein where extracellular C-terminal 102 amino acids of CD98hc are replaced with β geo. Analyses of PST080 ES cells as well as reconstituted frog oocytes demonstrated that ΔCD98hc-β geo fusion protein preserved its ability to interact with integrin β1 although this mutant protein was hardly localized on the cell surface. These findings suggest that ΔCD98hc-β geo protein can mediate integrin signaling but cannot support amino acid transport through LATs. CD98hc^Δ/+mice were normal. Although some of the implantation sites lacked embryonic component at E9.5, all the implantation sites contained embryonic component at E7.5. Thus, CD98hc^Δ/Δembryos are likely to die between E7.5 and E9.5.</p> <p>Conclusions</p> <p>Considering that CD98hc complete knockout (CD98hc^-/-) embryos are reported to die shortly after implantation, our findings suggest potential stage-specific roles of CD98hc in murine embryonic development. CD98hc may be essential for early post-implantation development by regulating integrin-dependent signaling, while the other function of CD98hc as a component of amino acid transporters may be required for embryonic development at later stages.</p

Placenta Accreta in a Woman with Childhood Uterine Irradiation: A Case Report and Literature Review

The pregnancies of childhood cancer survivors who have received uterine irradiation are associated with a high risk of several obstetrical complications, including placenta accreta. The present case was a 26-year-old pregnant woman with a history of myelodysplastic syndrome treated with umbilical cord blood transplantation following chemotherapy and total body irradiation at the age of 10. Despite every possible measure to prevent preterm labor, uterine contractions became uncontrollable and a female infant weighing 892 g was vaginally delivered at 27⁺⁴ weeks of gestation. Under the postpartum ultrasonographic diagnosis of placenta accreta, we selected to leave the placenta in situ. Although emergency bilateral uterine artery embolization was required, complete resorption of the residual placenta was accomplished on the 115th day postpartum. Our experience highlighted the following points. (1) The expectant management of placenta accreta arising in an irradiated uterus may not only fulfill fertility preservation, but may also reduce possible risks associated with cesarean hysterectomy. (2) Due to extreme thinning of and a poor blood supply to the myometrium, reaching an antepartum diagnosis of placenta accreta in an irradiated uterus is difficult. (3) The recurrence of placenta accreta in subsequent pregnancies needs to be considered after successful preservation of the uterus

ジュウモウガイ トロホブラスト ノ シンジュン ブンカ ニ オケル dipeptidyl peptidase4 ノ カンヨ

京都大学0048新制・課程博士博士(医学)甲第10092号医博第2602号新制||医||828(附属図書館)UT51-2003-H513京都大学大学院医学研究科外科系専攻(主査)教授 小川 修, 教授 武藤 誠, 教授 藤井 信吾学位規則第4条第1項該当Doctor of Medical ScienceKyoto UniversityDA

Management of fetal death with placenta previa.

Management of second- and third-trimester fetal death in the presence of placenta previa is a dilemma for obstetricians. We herein describe a case of fetal death occurring at 23 weeks' gestation in the presence of placenta previa. Three weeks of expectant management failed to reduce uteroplacental blood perfusion evaluated with pulsatility index of the uterine artery. Labor was then induced with gemeprost vaginal pessary following overnight laminaria pretreatment. Vaginal delivery was achieved with total blood loss of 1900 ml. Homologous blood transfusion was obviated owing to autologous blood that had been stored during the waiting period

Role of platelets in placentation.

In the human placenta, embryo-derived trophoblasts aggressively invade maternal spiral arteries and transform the arteries to low-resistance large-caliber vessels. This process, which ensures adequate placental perfusion, is called maternal vascular remodeling. Histological examination showed deposition of maternal platelets in the trophoblast aggregates formed in the spiral arteries. Several lines of evidence suggest that these platelets are activated. Soluble factors released from the activated platelets, as a whole, enhanced invasive capacity of isolated trophoblasts in vitro. These findings suggest the importance of nonhemostatic platelet function in maternal vascular remodeling. In contrast, gene knockout studies suggest that maternal platelet defects are compatible with successful pregnancy in mice. Moreover, pregnant women with severe platelet defects usually accomplish an uneventful pregnancy. Thus, promotion of endovascular trophoblast infiltration by maternal platelets might not be the only mechanism that regulates maternal vascular remodeling. The maternal vascular remodeling is an essential component of human reproduction and should be secured by several complementary mechanisms. Future studies should aim to elucidate other mechanisms that could regulate endovascular trophoblast infiltration

Management of retained products of conception with marked vascularity.

Cases of retained products of conception (RPOC) with marked vascularity present a clinical challenge because simple dilation and curettage (D&C) can lead to life-threatening hemorrhage. We describe here two cases of hypervascular RPOC that were successfully managed with two different approaches. Case 1: A 26-year-old woman with history of 3 D&Cs was transported to the emergency room for heavy vaginal bleeding 45 days after a spontaneous abortion. Diagnosis of RPOC with aneurysm-like structure was considered and uterine artery embolization was performed. Four days after the uterine artery embolization, reduction of the vascularity of RPOC was confirmed on color Doppler ultrasonography and D&C was successfully carried out. Case 2: A 37-year-old woman with history of one cesarean section became pregnant after the regular menses. She underwent D&C for missed abortion at 8 weeks' gestation. Seven days after the D&C, sonographically heterogenous mass emerged in the vicinity of the previous cesarean scar. Thereafter, the mass gradually grew larger and diagnosis of hypervascular placental polyp was considered. As the amount of vaginal bleeding was small, expectant management was instituted. Sixty-one days after the first D&C, reduction of the vascularity of RPOC was confirmed on color Doppler ultrasonography and D&C was successfully completed

Middle cerebral artery-peak systolic velocity in dizygotic twins with anti-E alloimmunization.

Middle cerebral artery-peak systolic velocity (MCA-PSV) has been reported to predict fetal anemia with similar accuracy as amniotic ΔOD450 assay. Alloimmunized dizygotic twin pregnancy allows us to compare anemic and non-anemic twins in the same intrauterine environment. We herein present a case of Rh (E)-incompatible dizygotic twin pregnancy, where MCA-PSV could precisely detect the anemia in one of the twins. A 36-year-old woman, whose previous child required exchange transfusion due to hemolytic anemia of newborn (HFDN), conceived twins after in vitro fertilization-embryo transfer. At 24 weeks' gestation, MCA-PSV of twin A and twin B were 23.9 cm/s (0.8 multiples of median; MoM) and 30.7 cm/s (1.0 MoM), respectively. At 31 weeks' gestation, MCA-PSV values of both twins were sharply elevated to nearly 1.4 MoM. Thereafter, MCA-PSV of twin A fell to 1.0 MoM, whereas MCA-PSV of twin B exceeded 1.5 MoM at 34 weeks' gestation. Development of fetal anemia was suspected and emergency cesarean section was performed. Twin B showed moderate anemia with positive direct Coombs' test and was diagnosed as HFDN due to anti-E alloimmunization. Twin B required phototherapy and red cell transfusion, but exchange transfusion was safely obviated

Near-infrared source counts in the galactic plane. Part 2: A list of near-infrared sources

Results of near infrared source counts are presented as a list of positions and magnitudes of sources observed in 17 selected areas sampled along the galactic plane between l=349 deg and l=45 deg. The total scanned area was 12 square degrees, and 1,989 sources brighter than 6.5 mag in the K-band are listed. They are also graphically presented in (α,∂)-(l,b) maps classifying the magnitudes and the colors of the sources