Shinobu Akada

Absence of estrogen receptor-α expression in human ovarian clear cell adenocarcinoma compared with ovarian serous, endometrioid, and mucinous adenocarcinoma

The mechanism that regulates growth in ovarian clear cell adenocarcinoma (CCA) is not well understood. A high incidence of concurrent endometriosis with CCA may indicate that estrogen is a growth promotor in CCA. To determine estrogen as a growth promotor, the authors investigated the presence or absence of estrogen receptor-&agr; (ER-&agr;), ER-&bgr;, progesterone receptor, and dioxin receptor (i.e., aromatic hydrocarbon receptor) in clinically resected ovarian CCA, serous adenocarcinoma (SAC), endometrioid adenocarcinoma (EAC), and mucinous adenocarcinoma (MAC) specimens using an immunohistochemical method. Expression of ER-&agr; and ER-&bgr; messenger ribonucleic acid was examined by reverse transcription–polymerase chain reaction in three established CCA cell lines: KK, RMG-1, and HAC-II. None of the surgically resected CCA and CCA cell lines showed positive staining for ER-&agr;. Conversely, 97.2% of SACs, 100% of EACs, and 70% of MACs showed positive nuclear staining for ER-&agr; (p <0.001). Conversely, positive ER-&bgr; staining for CCA (39.3%) was similar to that of SAC (41.7%) and MAC (30.0%). EAC (75%) showed a higher expression of ER-&bgr; (p <0.02). Progesterone receptor was detected in only 10.7% of CCA, compared with SAC and EAC (SAC, 86.1%; EAC, 91.7%; p <0.01). Aromatic hydrocarbon receptor was detected in all histologic types at an incidence of approximately 50% to 60%. Messenger ribonucleic acid of ER-&agr; and ER-&bgr; was not detected in the three CCA cell lines. These findings indicate biologic characteristics that distinguish CCA from other types of ovarian epithelial cancer.

Characterization of Human Placental Activity for Transport of L-alanine, Using Brush Border (Microvillous) Membrane Vesicles

The uptake of taurocholate into brush border membrane vesicles prepared from human full term placenta was studied using a rapid filtration technique. The taurocholate uptake into brush border membrane vesicles was sensitive to extravesicular osmolarity, and pre-incubation of the brush border membrane vesicles with the taurocholate increased the uptake of taurocholate into the brush border membrane vesicles. These findings indicate that the uptake of taurocholate by brush border membrane vesicles represents transport into vesicles. The uptake of taurocholate into vesicles was not dependent on Na+ electrochemical gradient (extravesicular > intravesicular). But this uptake was markedly increased when the intravesicular space was rendered electrically more positive by the use of lowly permeant anions or valinomycin-induced K+ diffusion membrane potentials. These findings indicate that the taurocholate transport into brush border membrane vesicles was dependent on membrane potential. The initial rate of taurocholate transport into brush border membrane vesicles exhibited saturation kinetics with respect to the taurocholate concentration, an apparent Km of 67 microM and Vmax of 0.30 nmol/mg protein/20 sec were calculated.

Mirimostim (macrophage colony‐stimulating factor; M‐CSF) improves chemotherapy‐induced impaired natural killer cell activity, Th1/Th2 balance, and granulocyte function

The purpose of this study was to clarify the effects of mirimostim (macrophage colony‐stimulating factor; M‐CSF) on immunological functions after chemotherapy. The percentage of natural killer (NK) cells in peripheral blood mononuclear cells (PBMCs), NK cell activity, T‐helper cell 1/T‐helper cell 2 (Th1/Th2) ratio, and superoxide anion production by granulocytes (granulocyte function) were measured as immunological parameters before and after chemotherapy in 44 patients with primary ovarian cancer who received at least three consecutive courses of postoperative chemotherapy. Patients were observed during the first course of chemotherapy, and 39 patients who presented grade III or IV neutropenia were entered into this study and randomly allocated to an M‐CSF‐administered group (group 1; 19 patients) and a non‐M‐CSF‐administered group (group 2; 20 patients) for the second course. For the third course, a crossover trial was conducted. In the observation period, chemotherapy significantly impaired the immunological parameters. In particular, those parameters were significantly decreased at day 14 compared to the level before chemotherapy. The values of the parameters of group 1 were significantly higher than those of group 2. In the course of chemotherapy during which M‐CSF was administered, 19 of the 39 patients presented grade IV neutropenia, and received granulocyte colony‐stimulating factor (G‐CSF) between days 7 and 14. We compared the changes of those immunological parameters in the M‐CSF alone group and the M‐CSF+G‐CSF group, and found that the concomitant use of G‐CSF did not further improve the parameters. These results indicate that chemotherapy markedly impaired the immunological functions, and that the administration of M‐CSF significantly improved the impaired immunological functions.

Platelet aggregation inhibiting activity of human placental chorioepithelial brush border membrane vesicles.

We investigated the platelet aggregation inhibiting activity of human placental brush border membrane vesicles (BBMV) and obtained the following results. A strong platelet aggregation inhibiting activity existed in placental BBMV. The BBMV inhibited the platelet aggregation induced by ADP, arachidonic acid, collagen and ristocetin in a dose-dependent manner. The protein concentration of BBMV giving 50 per cent inhibition was 52 +/- 6 micrograms/ml for ADP-induced platelet aggregation, 21 +/- 2 micrograms/ml for arachidonic acid-induced platelet aggregation, 19 +/- 2 micrograms/ml for collagen-induced platelet aggregation and 107 +/- 9 micrograms/ml for ristocetin-induced platelet aggregation. There was a high level of ADP degrading activity (ADPase activity) in the placental BBMV. ADP degrading activity of the BBMV: 10.5 +/- 0.5 mumol/mg protein/min was 21 times greater than that of homogenate of the placental villi. The placental BBMV inhibited platelet TXA2 production. In the 40 micrograms/ml protein concentration of placental BBMV, platelet TXA2 production was almost completely inhibited.

Platelet aggregation inhibiting activity of human placental chorioepithelial brush border membrane vesicles: the role of alkaline phosphatase

Human placental chorioepithelial brush border membrane, which is in direct contact with maternal blood flow, has platelet aggregation inhibiting activity. In the present study, the mechanism of this action has been examined in relation to ADP (adenosine diphosphate) degrading activity and alkaline phosphatase activity of brush border membrane vesicles (BBMV). BBMV prepared from human early and term placental villi, inhibited platelet aggregation induced by ADP. BBMV had potent ADP degrading (ADPase) activity. ADP was quickly degraded by BBMV. ADP degrading activity of BBMV was not so different between early and term placenta. Alkaline phosphatase activity of late placental BBMV was about three times greater than that of early placental BBMV. On the other hand, ADP degrading activity of late placental BBMV was almost the same as that of early placental BBMV. Inhibiting activity of platelet aggregation induced by ADP and ADP degrading activity of BBMV, were not inhibited by levamisole (alkaline phosphatase inhibitor).

Studies on placental inhibition of platelet aggregation: A comparison of human syncytiotrophoblast brush border and basal plasma membranes

We compared the platelet aggregation inhibiting activity of human placental syncytiotrophoblast brush border membrane vesicles (BBMV) and basal plasma membrane vesicles (BpMV), and obtained the following results. Strong platelet aggregation inhibiting activity is found in placental BBMV. BBMV inhibited platelet aggregation induced by ADP (adenosine diphosphate) and arachidonic acid in a way which depended on the protein concentration of BBMV added. In contrast, BpMV showed no detectable platelet aggregation inhibiting activity. Quite high ADP degrading activity (ADPase activity) was present in the placental BBMV. ADP was quickly degraded by BBMV. In contrast, BpMV did not degrade ADP so quickly. Platelet TXB2 production was almost completely abolished at the protein concentration of 40 micrograms/ml of BBMV. In contrast, BpMV did not significantly inhibit platelet TXA2 (TXB2) production. These results show that syncytiotrophoblast brush border and basal plasma membranes of the human placenta have markedly different properties with respect to platelet aggregation inhibiting activity.

Platelet-aggregation inhibiting activity of human placental chorioepithelial brush border membrane vesicles and basal plasma membrane vesicles

Summary This laboratory investigated the platelet-aggregation inhibiting activity of human placental brush border membrane vesicles (BBMV) and basal plasma membrane vesicles (BpMV), and obtained the following results. o 1) A strong platelet-aggregation inhibiting activity exists in placental BBMW. In a 20 μg/ml protein concentration, the BBMV completely inhibited the secondary platelet aggregation induced by ADP. In a 40 μg/ml protein concentration, the BBMV completely inhibited the platelet aggregation induced by arachidonic acid and collagen, and in a 200 μg/ml protein concentration, the BBMV completely inhibited the platelet aggregation induced by ristocetin. However, placental BpMV did not show prominent platelet-aggregation inhibiting activity on platelet aggregation induced by ADP, arachidonic acid, collagen, or ristocetin. 2) A strong ADP degrading activity (ADPase activity) in the placental BBMV was found. ADP-degrading activity of the BBMV was 10.5±0.5 μmol/mg protein/minute and ADP-degrading activity of BpMV was 0.6±0.1 μmol/mg protein/minute. 3) The placental BBMV inhibited platelet thromboxane A 2 (TXA 2 ) production. In a 40 μg/ml protein concentration of placental BBMV, a platelet TXA 2 (TXB 2 ) production was almost completely inhibited. BpMV did not show prominent inhibitory activity on platelet TXA 2 (TXB 2 ) production. These results indicate that brush border membrane and basal plasma membrane have a different function in the respect of platelet-aggregation inhibiting activity, and that the brush border membrane may play an important role inhibiting platelet aggregation.

Platelet Aggregation Inhibition Activity of Placental Brush Border Membrane

Thrombus occurs frequently in the placental chorionic lumen of patients with Pre-ecclampsia (EPH) gestosis, and participation of platelets is suggested in the pathology of the diseases. In the placental tissues, there is an antiplatelet aggregating factor which plays an important role in the maintenance of microcirculation in the placenta. The brush border membrane of the placental chorioepithe-lium plays the part of the vasoendothelium as it is the point of direct contact with the maternal blood flow in the chorionic lumen. It has already been confirmed that a strong inhibitory action on platelet aggregation is present in the vasoendothelium, and its main active mechanism is shown to be prostacyclin (PG I2) and ADP degrading by an ADPase-like activity which exists in edothelial membrane. Thus, it is quite possible that some inhibitory activity on platelet aggregation exists in the brush border membrane of placental chorioepithelium. We, therefore, investigated the presence of such an inhibitory activity on platelet aggregation as well as its properties using a fraction of the brush border membrane.