This study aimed to investigate the changes in apoptosis in the placenta and decidua of pregnant mice lacking the prostaglandin F receptor. Mouse placentae were removed from fetuses on days 10-23 of pregnancy. Apoptotic cells were examined by a DNA fragmentation assay and the terminal deoxynucleotidyl transferase-mediated dUDP nick end-labelling (TUNEL) technique. The placenta and decidual weight increased before day 18 and 14 of pregnancy, and then decreased with gestational day. After day 19, the fetuses gradually died in the uterus. All fetuses died in the uterus on day 23 of pregnancy. The number of apoptosis was not significantly different between wild type and FP-deficient mice before day 18 of pregnancy by DNA fragmentation and TUNEL staining. The DNA fragmentation was always more pronounced in decidual tissue on each day of pregnancy. DNA laddering on placentae was more extensive on day 22 than day 18. In placenta, most TUNEL-positive cells were detected in trophoblast and stromal cells. A higher intensity of apoptotic cells was in the decidual basalis. The main area was the centre of the decidual basalis, and was in decrease toward to margin of placenta. The index of TUNEL positive cells increased as gestation progressed toward termination. Especially, it was prominent in the placentae on day 22 compared with that day 18 of pregnancy. The increased TUNEL-positive staining in syncytiotrophoblast surface was found in placenta at post-term, compared with those at term. Apoptosis may provide insights into both normal placental development and placental dysfunction during an abnormal pregnancy from post-term pregnancy.

Animals↗

PubMedDate not supplied

An analysis of turn-taking and backchannels based on prosodic and syntactic features in Japanese map task dialogs.

In this study, we investigate syntactic and prosodic features of the speaker's speech at points where turn-taking and backchannels occur, on the basis of our analysis of Japanese spontaneous dialogs. Specifically, we focus on features such as part of speech, duration, F0 contour pattern, relative height of the peak F0, energy trajectory pattern, and relative height of the peak energy at the final part of speech segments. We examine, first, the relationship between turn-taking/backchannels and each feature of speech segments independently, showing that the features examined in this study are all related to turn-taking or backchannels and that the way they correlate is fairly consistent with previous studies. Next, we explore the inter-relationship among the features with respect to turn-taking and backchannels. We show that in both turn-taking and backchannels, (1) some instances of syntactic features make extremely strong contributions, and (2) in general, syntax has a stronger contribution than any individual prosodic feature, although the whole prosody contributes as strongly as, or even more strongly than, syntax. We also discuss some implications of our results, comparing them with previous models that have mentioned roles of syntax and prosody in turn-taking and backchannels.

Attention↗

PubMedDate not supplied

Structure and function of prostanoid receptors.

We have recently cloned cDNAs for the human and mouse TXA2/PGH2 receptors and a cDNA for the mouse PGE receptor. Sequencing, homology and hydrophobicity analyses revealed that they are proteins of 343, 341 and 365 amino acid residues, respectively, and all are rhodopsin-type receptors with putative seven transmembrane domains. Homology between the human and mouse TXA2 receptors is 76% in total and that between the human TXA2 and mouse PGE receptors is 38%. The homology increases in the putative transmembrane regions to 85 and 45%, respectively, and there observed several features common to the three receptors. These results indicate that the prostanoid receptors constitute a family of receptors of similar structure. The cloned PGE receptor showed binding activity specific to so-called EP3 agonists, which verified for the first time that pharmacologically defined PGE receptor subtypes consist of different molecules. This receptor also displayed different efficiency in signal transduction to an EP3 agonist, M & B-28767, and PGE2, providing an interesting model for the analysis of receptor-G protein coupling. In addition to the above biochemical results, these studies have revealed the characteristic tissue distribution of these receptors, which will open up a new biology of these prostanoids.

Amino Acid Sequence↗

PubMedDate not supplied

5-FU-induced apoptosis correlates with efficacy against human gastric and colon cancer xenografts in nude mice.

Apoptosis may be an important mechanism by which cancer cells are killed by certain agents. It is reported here that apoptosis is a key event in the killing of human tumor cells by 5-fluorouracil (5-FU) in vivo. Apoptosis induced by 5-FU was determined using two human gastrointestinal tumor xenografts serially transplanted into nude mice: a gastric carcinoma (SC-1-NU) highly sensitive to 5-FU and a colon carcinoma (Co-4) less sensitive to 5-FU. Apoptosis was assayed using the terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-biotin nick end labeling method in paraffin-embedded tissue sections, and by flow-cytometric analysis. Apoptosis-positive cells increased gradually during treatment. 24 hours after the initiation of 5-FU treatment a maximum, of 15.4% of the Co-4 cells were apoptotic. 48 hours after the initiation of 5-FU treatment, apoptosis was found in 34% of the tumor cells in the SC-1-NU strain. Flow-cytometry demonstrated the increase of S-phase fractions in both strains after the administration of 5-FU, and this coincided with the appearance of apoptotic-positive cells. Although the intrinsic. TS activities of two strains differed, TS activities were markedly suppressed in both strains immediately after the administration of 5-FU. Concentration of 5-FU in RNA (F-RNA) increased gradually in both strains, reaching a maximum 24 hours after the administration of 5-FU. These results suggest that apoptosis and inhibition of DNA synthesis induced by 5-FU are closely associated with its antitumor effect.

Animals↗

PubMedDate not supplied

Bcl-2 expression as a prognostic factor of survival of gastric carcinoma.

BACKGROUND: Although the bcl-2 proto-oncogene is important in determining tumor cell susceptibility to apoptosis, no data about the clinical importance in gastric cancer are available. METHODS: We analyzed bcl-2 and p53 expression, proliferative activity, and tumor apoptosis in locally advanced gastric carcinomas from 84 patients. RESULTS: Immunohistochemical analysis indicated that 41.7% and 48.8% of the tumors were bcl-2-positive, respectively. The apoptotic fraction was significantly lower in bcl-2-positive than negative tumors. Univariate analysis indicated low apoptotic fraction was one of the poor prognostic factors. Multivariate analysis showed a trend toward improved survival in bcl-2-positive patients. In patients with lymph node metastases more severe than group 2 lymph node, survival was significantly longer in those with bcl-2-positive tumors. CONCLUSIONS: The expression of bcl-2 and the high apoptotic fraction were concluded to be important prognostic factors of survival in patients with advanced gastric cancer.

Adenocarcinoma↗