The immunological mechanisms that regulate abortion are largely unknown. Here, we found that a distinct subset of lymphocytes, V␣14 NKT cells expressing an invariant antigen receptor encoded by V␣14͞J␣281 and V␤7 segments, accumulated in the decidua during pregnancy and provoked abortion upon stimulation with ␣-galactosylceramide (␣-GalCer), a specific ligand for V␣14 NKT cells. The ␣-GalCer-mediated abortion was not observed in V␣14 NKT-, IFN-␥-, tumor necrosis factor ␣-, or perforin-knock-out mice and appeared to be due to the degeneration of embryonic trophoblasts mediated by the activated V␣14 NKT cells whose perforin-dependent killing and production of IFN-␥ and tumor necrosis factor ␣ were essential. The possible role of the decidual V␣14 NKT cells in the pathogenesis of abortion is discussed.

A national collaborative study was conducted in Japan to evaluate the clinical course and the sequelae of patients with hydatidiform mole coexistent with twin live fetus (HMTF). Seventy-two cases of HMTF were diagnosed based on gross appearance and histopathological criteria. In 18 cases, the molar parts were cytogenetically confirmed to be of androgenetic origin (complete mole). The overall incidence of persistent trophoblastic tumour (PTT) in patients with HMTF was 30.6%, and it increased to 50.0% in the 18 patients with proven androgenetic complete mole coexistent with twin live fetus (CHMTF). Among these patients, the mean gestational age at termination of pregnancy or delivery in those who developed PTT (n = 9) and those who did not (n = 9) were 20.6 and 19.4 weeks respectively. The incidence of severe maternal complications was significantly higher in patients who subsequently developed PTT (P < 0.05). The rate of subsequent development of PTT in patients with CHMTF was found to be considerably higher than in a previous study of patients with single complete mole (50 and 12.5% respectively). However, since the risk of malignancy is unchanged with advancement of gestational age, continued pregnancy may be allowed in patients with HMTF provided that severe maternal complications are controlled and fetal karyotype and development are normal.

SUMMARYFive cell lines, SKG-I, SKG-II, SKG-IIIb, QG-U and QG-H derived from cervical carcinomas of Japanese patients, were examined for the presence of human papillomavirus (HPV) DNA and the expression of viral mRNA. The DNA of HPV type 16 was shown to be linked covalently with SKG-IIIb, QG-U and QG-H cell DNA, and HPV 18 DNA with SKG-I and SKG-II cell DNA. Although different regions of the HPV genome were integrated in these cell lines, the non-coding region and an early region including the E6 and E7 open reading frames (ORFs) were conserved in all cell lines. The complete genome of HPV 16 was found in QG-H cells by digestion of the DNA with a single-cut restriction enzyme. The other early region ORFs E 1, E2, E4 and E5 were interrupted by flanking host cell DNA, suggesting that the integration into host cell DNA occurs preferentially in this region. HPV-specific mRNA species were detected in all five cell lines. In the three cell lines containing the HPV 16 genome, mRNAs hybridized with the early region of the genome, covering the entire E6 and E7 ORFs and a minor part of the E10RF, although the amount and size of the major mRNAs varied in these cell lines. These mRNAs did not hybridize with the late region of the HPV genome containing the LI and L20RFs. In SKG-II, SKG-IIIb and QG-H cells we also detected c-myc and c-Ha-ras mRNA expression at about nine times the level of that in normal cells.The human papillomaviruses (HPVs) induce epithelial proliferative lesions of skin or mucosa and have been classified into more than 40 types on the basis of their DNA sequence homology.

Simultaneous measurement of fetal lung volume and signal intensity on MR images is a promising method for predicting fetal pulmonary hypoplasia.