Naomi Furuta

Immunohistochemical detection of meconium in the fetal membrane, placenta and umbilical cord

OBJECTIVE To develop the immunohistochemistry specific for meconium in the placenta, fetal membrane and umbilical cord. STUDY DESIGN We previously reported the specific presence of zinc coproporphyrin I (ZnCP-I) in human meconium and demonstrated the possible diagnostic use of an elevation in maternal plasma ZnCP-I levels in cases of amniotic fluid embolism. In this study, we developed a new specific monoclonal antibody for ZnCP-I and applied it to the immunostaining of meconium in the placenta, fetal membrane, and umbilical cord. RESULTS Immunoreactivity of ZnCP-I clearly and specifically identified meconium in the placenta, fetal membrane, and umbilical cord. It was especially useful in cases of severe chorioamnionitis to detect meconium in the macrophages surrounded by numerous neutrophils. In more than half of the cases, meconium was detected in clear amniotic fluid at delivery, suggesting previous exposure. CONCLUSIONS Immunohistochemical detection of ZnCP-I is a highly sensitive histological diagnosis of meconium.

Morphologic characteristics of the placental basal plate in in vitro fertilization pregnancies: a possible association with the amount of bleeding in delivery.

The aim of the present study was to investigate the relationship between assisted reproductive technology procedures, the morphology of the basal plate of placentas, and amount of bleeding in deliveries. Fifty-five whole placentas (fresh-embryo transfer in the in vitro fertilization cycle [n = 6], frozen-thawed embryo transfer in the natural cycle [n = 13] or in the hormonal cycle [n = 10], and age-matched spontaneously conceived pregnancies [n = 26]) were retrospectively enrolled and histologically analyzed. The whole placentas were stored in our pathological division among 512 singleton pregnancies with vaginal deliveries (34-41 weeks of gestation) at Hamamatsu University Hospital. The morphology of the placental basal plate was examined using Azan staining. A total of 20 digital images (each 0.53 mm(2)) of microscopic fields were analyzed per placenta to measure the mean values of the vertical maximum thickness of Rohr and Nitabuch fibrinoid layers and % loss of decidua. The thickness of Rohr fibrinoid layer and % loss of decidua were significantly higher in the frozen-thawed embryo transfer in the hormonal cycle group than in the frozen-thawed embryo transfer in the natural cycle and spontaneously conceived pregnancy groups (each P < .01). The z scores for both the thickness of Rohr fibrinoid layer and % loss of decidua positively correlated with those for the amount of bleeding in deliveries (P < .05 each). Assisted reproductive technology procedures changed the morphology of the placental basal plate, suggesting a possible association with an increase in the amount of bleeding in deliveries.

Examiner ' s finger-mounted fetal tissue oximetry: a preliminary report on 30 cases

Abstract Objective: To describe preliminary experience with a finger-mounted fetal tissue oximetry probe during the 2nd stage of labor. Materials and methods: A total of 30 term pregnant women without pregnancy complications were recruited. We measured fetal tissue oxygen saturation (FtO2) by using a finger-mounted fetal tissue oximetry during cervical examinations in the 2nd stage of labor. The data capturing rate of FtO2 and the interclass correlation coefficient were also examined. The mean FtO2 was compared to the neonatal condition assessed by the levels of umbilical cord blood. Results: FtO2 was obtained in all cases, regardless of wetness, hair color, the part of the fetal head that was exposed, rotation of the fetus, color of amniotic fluid, and caput succedaneum. The mean FtO2 was 65.5%±8.58% in normal neonates [Apgar score >7 (1 min), n=25]. The mean FtO2 was significantly correlated with umbilical cord arterial pH (r=0.52, P=0.0030, n=30), but not with umbilical cord arterial partial pressure of oxygen. The interclass correlation coefficient was 0.94. Conclusions: Tissue oxygen saturation of the fetal head was obtained easily by the examiner’s finger-mounted fetal tissue oximetry.

Histological characteristics of the myometrium in the postpartum hemorrhage of unknown etiology: a possible involvement of local immune reactions

The aim of this study was to evaluate the histological characteristics of the myometrium obtained in postpartum hemorrhage (PPH) of unknown etiology secondary to uterine atony. These characteristics were selected from among registered cases of clinically suspected amniotic fluid embolism (AFE) and classified as PPH of unknown etiology because of no obvious cause of PPH at Hamamatsu University School of Medicine, a registration center for clinical AFE in Japan. Immunohistochemical studies were performed on myometrium using anti-mast cell tryptase, anti-neutrophil elastase, anti-CD68, anti-CD88, anti-CD3, and anti-ZnCP-1 antibodies. Massive infiltrations of inflammatory cells with mast cell degranulation within the myometrium secondary to complement activation were observed in PPH of unknown etiology (n=34), but not in control pregnant women (n=15) or after delivery in women without PPH (n=18). The concomitant immunohistochemical detection of meconium in myometrium suggests that amniotic fluids or fetal materials are one of the candidates for inducing maternal local immune activation in the PPH of unknown etiology. Postpartum acute myometritis in the absence of an infective etiology may be a histological characteristic of PPH of unknown etiology.

Immunohistochemical detection of meconium in the fetal lung: report of autopsied cases.

Meconium is a bile-stained material present in the small bowel of fetuses long before mid-gestation, which moves in the intestinal lumen with contractions of the intestinal wall [1]. Although meconium aspiration syndrome could deteriorate neonatal mortality and morbidity, the pathophysiological involvement of meconium is still contentious [2], because autopsy studies suggested prenatal origins of intrauterine infection and/or chronic hypoxia [2–4]. The lack of universal diagnostic criteria for meconium staining is one of the reasons for the confusion. We previously reported the specific presence of zinc coproporphyrin I (ZnCP-I) in human meconium [5], recently developed a specific monoclonal antibody for ZnCP-I [6], and successfully applied it to the immunostaining of meconium in the human placenta, fetal membrane, and umbilical cord [6]. In the present study, we applied the antibody for ZnCP-1 to immunohistochemical examination of the autopsied lung following one early neonatal death and eight intrauterine fetal deaths between 28 and 38 weeks of gestation at Hamamatsu University Hospital between 1996 and 2003. Paraffin blocks, after fixation in 10 % formaldehyde, were cut into 3 lm sections. After the application of a mouse monoclonal anti-ZnCP-I antibody (120 ng/ml) or anti-CD 68 antibody (fourfold dilution from initial liquid; Dako Japan, Tokyo, Japan) to the sections (1 h, room temperature), detection was performed with a polymer detection kit (ChemMate EnVision; Dako Japan, Tokyo, Japan), followed by a reaction with 3,30-diaminobenzidine and counterstaining with hematoxylin [6]. Alcian blue staining was performed for the detection of mucin. The findings were compared to those of hematoxylin and eosin (HE) staining. Alcian blue staining has been frequently used in the histochemical detection of amniotic fluid components [7]. However, the immunostaining of ZnCP-I was apparently clear compared to Alcian blue staining of amniotic mucin in the autopsied lung (Fig. 1a–c). Among nine autopsied lungs, positive immunostaining for ZnCP-I was detected in five cases. Recently, we revealed that immunostaining of ZnCP-I was observed in the CD68-positive macrophages in the placenta, fetal membrane, and umbilicus [6], supporting the classical concept of ‘‘meconium macrophages’’ [8] in these tissues. In contrast, ZnCP-I immunostaining was observed independent of CD68-positive macrophages in three cases of autopsied lung (Fig. 1d, e), being distinct from the placentas exposed to meconium. While in two cases of autopsied lung, some ZnCP-I immunostaining was mainly detected in CD68-positive macrophages resembling ‘‘meconium macrophages’’ (Fig. 1f, g), other ZnCP-I immunostaining was independent of CD68-positive macrophages. In the fetal membrane, phagocytosis of meconium was reported to usually be observed within an hour after exposure [9] and constitute the majority of the meconium content in the fetal membrane [6, 10]. The present findings suggest that phagocytosis of meconium was observed in a case-dependent manner among autopsied lungs, suggesting the possibility of heterogeneous physiological and/or pathological involvement. In conclusion, the immunohistochemical detection of ZnCP-I is highly sensitive and useful to assess meconium in the autopsied fetal lung. N. Furuta C. Yaguchi H. Itoh (&) N. Kanayama Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 341-3192, Japan e-mail: hitou-endo@umin.ac.jp