Increase in Pit-1 mRNA is not required for the estrogen-induced expression of prolactin gene and lactotroph proliferation

Estrogen has been shown to stimulate lactotroph proliferation and expression of the prolactin (PRL) gene. Recently it has been established that Pit-1, a pituitary-specific transcription factor, is required for lactotroph proliferation. Furthermore, in vitro studies showed that an increase in the PRL promoter activity caused by estrogen was dependent of the amount of cotransfected Pit-1-expressing plasmid. These findings led us to examine whether the induction of Pit-1 mRNA is required for the estrogen-increased PRL gene expression in the rat anterior pituitary in vivo. Short term estrogen treatment was achieved by means of a single intramuscular injection of estradiol dipropionate. DNA synthesis, the levels of PRL and Pit-1 messenger RNAs in the anterior pituitary were determined. Estradiol dipropionate resulted in a significant increase in DNA synthesis 24 h after administration and in PRL mRNA after 48 h. In contrast, the Pit-1 mRNA level was not altered. Since Pit-1 is expressed not only in lactotroph but also in somatotroph and thyrotroph, and the lactotroph cell population has been reported to be less than 10% in the pituitary, the change in the Pit-1 mRNA level in lactotrophs was not seen following only short term estrogen treatment. An increase in the lactotroph cell population was therefore achieved by chronic estrogen treatment (subcutaneous implantation of a silastic tube containing 17 beta-estradiol powder for 30 days). This treatment resulted in the marked proliferation of lactotrophs and a 3-fold increase in PRL mRNA. However, no alteration in Pit-1 mRNA was observed. These results suggest that the increase in Pit-1 mRNA is not required for the estrogen-induced lactotroph proliferation or PRL gene expression.

Successful in vitro fertilization and pregnancy by micromanipulation with epididymal sperm

PURPOSE

To examine the effectiveness of micromanipulation on the treatment of the patients with obstructive azoospermia, subzonal insemination or partial zona dissection was performed using epididymal sperm of the 23 patients, and the in vitro fertilization and embryo transfer (IVF-ET) outcomes were analyzed.

RESULTS

Fertilized oocytes were obtained in 11 cycles of the 25 treated cycles, and six pregnancies were established by the subsequent ET. Through the analysis of 13 cycles in which both the micromanipulation and usual IVF insemination were performed, the fertilization rate per oocyte with the micromanipulation [25% (28/113)] was significantly higher than that with the usual insemination method [4% (4/102)]. The micromanipulation was most useful for the treatment of the patients with congenital absence of the vas deferens. Moreover, there was no need to aspirate a large volume of the epididymal fluid, but it was essential to prepare more than 10 mature oocytes retrieved.

CONCLUSIONS

These results indicate that micromanipulation with epididymal sperm is an effective treatment for obstructive azoospermia, and careful preparations of sperm and well-controlled ovarian hyperstimulation are necessary for successful IVF-ET.

Expression of aminopeptidase N on human choriocarcinoma cells and cell growth suppression by the inhibition of aminopeptidase N activity

We previously found that an aminopeptidase inhibitor, ubenimex (bestatin), had a growth-suppressive effect on choriocarcinoma cell lines in vitro. To clarify the mechanism of this action, we investigated the expression of aminopeptidase N (AP-N/CD13) on choriocarcinoma cells and other human tumor cells. Two choriocarcinoma cell lines, NaUCC-4 and BeWo, had higher AP-N activity than other cell lines (358.8 and 340.2 nmol/h/10(6) cells, respectively), as did human myeloid leukemia cell line, HL-60 (373.8 nmol/h/10(6) cells). These choriocarcinoma and leukemia cell lines with abundant AP-N activity showed much higher sensitivity to bestatin (IC50 = 0.5, 2.1 and 1.0 micrograms/ml, respectively) than the other cell lines. By immunoblotting and immunocytochemical staining, AP-N was detected as an approximately 165-kDa protein and localized on the cell membrane in choriocarcinoma cells. We also examined the effects of two other aminopeptidase inhibitors and three anti-CD13 monoclonal antibodies (MAbs) (WM15, MCS2 and MY7) on the growth of NaUCC-4 cells. Cell growth was markedly suppressed by the AP-N inhibitor actinonin as well as bestatin, but not by the AP-B inhibitor arphamenine. Of the three MAbs, only WM15, which is able to inhibit AP-N activity, suppressed cell growth in a dose-dependent manner. These results indicate that AP-N inhibitors show a growth-suppressive effect, presumably through inhibition of the enzymatic activity of AP-N on tumor cells, and suggest that AP-N may play important roles in the growth of certain tumors, such as choriocarcinoma and leukemia.

Expression of angiotensin-converting enzyme in human placenta and its physiologic role in the fetal circulation

OBJECTIVE

To clarify the physiologic function of angiotensin-converting enzyme (EC 3.4.15.1) in the human placenta.

METHODS

The concentrations of angiotensin I and angiotensin II were measured in the umbilical artery and vein. In addition, the expression of angiotensin-converting enzyme messenger RNA (mRNA) and its activity in the human placenta were studied. The amount of angiotensin-converting enzyme mRNA was measured by Northern blot hybridization with specific human complementary DNA.

RESULTS

The mean (+/- standard deviation) level of angiotensin I was significantly higher in the umbilical artery than in the umbilical vein (1044.5 +/- 626.5 versus 796.5 +/- 372.8 pg/mL; P < .05). In contrast, the mean level of angiotensin II was significantly lower in the umbilical artery than in the umbilical vein (97.3 +/- 102.9 versus 129.3 +/- 110.3 pg/mL; P < .05). Angiotensin-converting enzyme mRNA was detected in the human placenta at 4.5 and 3.9 kilobases. The amount of angiotensin-converting enzyme mRNA increased over the course of pregnancy but decreased near term, whereas angiotensin-converting enzyme activity in the human placenta continued to increase from the first trimester to term.

CONCLUSION

The placenta appears to contribute to the conversion of angiotensin I to angiotensin II in the fetal circulation.

Decrease in cytochrome c oxidase and cytochrome oxidase subunit I messenger RNA levels in preeclamptic pregnancies

OBJECTIVE

To elucidate the possible relation between mitochondrial gene expression and placental dysfunction.

METHODS

We measured the activity of cytochrome c oxidase and the expression of cytochrome oxidase subunit I in mitochondria from human placentas of women whose gestations were appropriate for gestational age (AGA) and those with preeclampsia. In addition, the amounts of normal mtDNA and deleted mitochondrial DNA were examined in the two groups by Southern blot analysis and polymerase chain reaction, respectively.

RESULTS

Cytochrome c oxidase activity and expression of cytochrome oxidase subunit I were significantly lower in the preeclamptic group than in the AGA group. There were no differences between the groups in the amounts of mitochondrial DNA. In addition, no mutant mitochondrial DNA with a 4977-base pair deletion was detected in the two groups.

CONCLUSION

These results suggest that reduced expression of the mitochondrial gene is involved in placental dysfunction in preeclamptic pregnancy.

Different pattern of zymography between human gynecologic normal and malignant tissues

OBJECTIVE

Our purpose was to evaluate type IV collagenase in ovarian and endometrial cancer tissues.

STUDY DESIGN

Tissue specimens were obtained from patients with ovarian and endometrial cancer and uterine myoma. Gelatinase activity was detected by zymography and quantitated by densitometer.

RESULTS

Four dominant gelatinases were detected in ovarian and endometrial cancer tissues: 200, 130, 92, and 72 kd gelatinase. Other forms observed were 83 kd gelatinase, which is an active form of 92 kd gelatinase, and 66 kd gelatinase, which is an active form of 72 kd gelatinase. Densitometric analysis showed that the 92 kd/72 kd ratio in ovarian cancer tissues was significantly higher than in normal ovarian tissues (p < 0.05) and that the 66 kd/72 kd ratio was higher in ovarian cancer tissues (p = 0.07). Both ratios in endometrial cancer tissues were significantly higher than in normal endometrial tissues (p < 0.05).

CONCLUSION

Gelatinase activity was remarkably higher in ovarian and endometrial cancer tissues. Especially, 92, 83, and 66 kd gelatinases were clearly detected in cancer tissues, suggesting that these gelatinases were related to the malignant phenotype, because degradation of the components of the basement membrane such as type IV collagen is necessary for cancer cells to metastasize.

[Maternal working status and low birthweight: findings from a cohort study]

To explore possible associations of maternal working status with birthweight, a cohort study was conducted from July, 1989 to June, 1991 in 8 general hospitals in the Tokai district. Using a self-administered questionnaire, data on job employment were collected mostly in the first or second trimester. Information on delivery outcome was recorded by doctors, midwives or nurses after child birth. Included in this analysis were 1,360 pregnants who delivered a live singleton without major malformations at gestation of 37 weeks or more. The following major findings emerged. (1) No significant difference in mean birthweight was detected between working and non-working pregnants. (2) Working pregnants were at greater risk of delivering a low birthweight (< 2,500g) baby. (3) Delivery of a low birthweight baby was more frequent in multiparous than nulliparous mothers. (4) The risks of delivering a low birthweight baby significantly differed according to the maternal working status. (5) These results suggest that not only the maternal working factor itself but the working status should be deliberately taken into consideration in order to provide proper prenatal care.

Intrauterine growth retardation and fetal distress associated with the excessively long (160 cm) umbilical cord

We present a case report in which we described an abnormally long umbilical cord coiled eight times around the fetal neck. This occurrence was considered to have caused intrauterine growth retardation and fetal distress.

Effect of interleukin 2 on the production of progesterone and prostaglandin E2 in human fetal membranes and its consequences for preterm uterine contractions

Our objective was to clarify the mechanism of uterine contraction induced in pregnant women by intrauterine bacterial infection. The concentration of interleukin 2 (IL-2) was measured in amniotic fluids that had been obtained by amniocentesis, transvaginal amniotomy or by transuterine amniocentesis performed at cesarean section in 50 pregnant women. The concentration of IL-2 in those cases with intrauterine infection was significantly higher than that of those without intrauterine infection at preterm. The same tendency was found at term. Scatchard analysis demonstrated the presence of an IL-2 receptor in the fetal membranes. We collected the fetal membranes aseptically for the measurement of progesterone and prostaglandin E2 by radioimmunoassay following incubation with various concentrations of interleukin 1 (IL-1) and IL-2 at 37 degrees C for 16 h. The production of progesterone was inhibited significantly by 10 pmol/l IL-2 but not by 10 pmol/l IL-1. The production of prostaglandin E2 was accelerated significantly by either IL-1 or IL-2 at a dose of 10 pmol/l. The inhibitory effect of IL-2 on the production of progesterone was unaffected by indomethacin, which inhibits the production of arachidonate cycloxygenase metabolites such as prostaglandin E2. Our present data suggest that the presence of intrauterine bacterial infection may stimulate the intrauterine production of IL-2, and that the stimulation of IL-2 and the reduction of progesterone caused by IL-2 may in part explain the mechanism of uterine contraction associated with intrauterine infection during pregnancy.

Human monoclonal antibody [1-1-2D] against cancer of the uterine cervix

To obtain a human monoclonal antibody (h-MAb) against cancer of the uterine cervix, lymphocytes from the regional lymph nodes of 14 patients with cervical cancer were fused with a mouse-human heterohybridoma [II]. Of 6,419 hybridomas, 1,295 produced human immunoglobulins (IgG 670, IgM 737). We isolated clone [1-1-2D], which has produced human IgM with stability for more than a year. This antibody reacted with three of five cell lines of cervical cancer but not with normal fibroblasts. Histoimmunostaining showed positive responses to 9/15 specimens of cervical cancer and in 2/7 specimens from cases of cervical dysplasia. Most of the normal human and fetal tissues showed no positive immune response. The positive immune response of [1-1-2D] to the cell membrane observed by the fluorescence antibody method disappeared after periodate treatment and was weakened by trypsin. Neuraminidase did not affect immune reactivity. This antibody showed a positive response by the thin-layer chromatography immunostaining method and precipitated a glycoprotein having a molecular weight of 38 kD. These results suggested that the epitope of the [1-1-2D] antibody is present on a carbohydrate moiety not containing sialic acid that is carried on protein and lipid moieties.

Amniotic fluid enhances allogeneic cytotoxic T cell responses, whereas it suppresses mitogen-stimulated lymphocyte proliferation

Mouse amniotic fluid has been shown to suppress T lymphocyte proliferation and suggested to be important in regulating immunity during pregnancy. In allogeneic pregnancy, cytotoxic T cells in pregnant lymphocytes against paternal transplantation antigen are impaired. We examined the effect of amniotic fluid to the alloreactive CTL responses. Although the amniotic fluid suppressed Con A or LPS stimulated lymphocyte proliferation as previously reported, the amniotic fluid taken from syngeneic C57BL/6 pregnant mice or allogeneic C57BL/6 x BALB/c pregnant mice enhanced the anti-H-2d or anti-H-2k CTL responses dose-dependently. We speculate that amniotic fluid contains not only immunosuppressive factors but also immunoenhancing factors which upregulate the allogeneic CTL responses.

Long-term follow-up of patients with epithelial carcinoma of the ovary

OBJECTIVES

To determine the long-term outcomes of patients with epithelial ovarian cancer.

METHODS

A group of 298 patients with epithelial ovarian cancer were treated with combination chemotherapy between July 1979 and January 1986 at the Tokai Ovarian Tumor Study Group. Long-term results of these patients were analyzed.

RESULTS

Five-year survival and 10-year survival rates of all the patients were 53% and 47%, respectively. Five-year survival and 10-year survival rates for stage I were 89% and 79%, 59% and 56% for stage II, 27% and 22% for stage III, and 9% and 9% for stage IV, respectively. Survival of mucinous and endometrioid cell types were decreased after 5 or more years. In stages II-IV, cisplatin-based chemotherapy produced better results than mitomycin-C, 5-Fu, cytarabine (MFC) therapy.

CONCLUSIONS

Long-term results of epithelial ovarian cancer were not favorable even in mucinous and endometrioid cell types. For long-term results, cisplatin-based chemotherapy was effective in advanced ovarian cancer. Long-term follow-up of ovarian cancer is important and necessary.

The value of Doppler ultrasound in the diagnosis and management of twin-to-twin transfusion syndrome

To evaluate the efficiency of the Doppler examination of umbilical arterial blood flow for the antenatal diagnosis and the monitoring of fetal condition during intrauterine treatment of twin-to-twin transfusion syndrome (TTTS), we studied 33 pairs of twins including 5 TTTS cases. In all cases umbilical arterial blood flow was examined by Doppler ultrasound and pulsatility index (PI) was calculated as umbilical arterial impedance. In twins with TTTS, PI of the recipient was outside the normal range and the difference of PI was greater than +0.5. In discordant twins without TTTS and concordant twins, the PI was within the normal range and the difference of PI ranged from -0.5 to +0.5. In 2 cases these findings were found before the appearance of fetal hydrops. In 2 TTTS cases transmaternal digitalization prevented the development of hydrops in the recipient. The difference of PI decreased with improvement in the fetal condition, and vice versa. Our data suggested that, in cases with TTTS, Doppler examination of umbilical arterial blood flow was effective in predicting fetal hydrops. Doppler was also very useful for monitoring the fetal condition during intrauterine treatment.

Sensitisation of human ovarian carcinoma cells to cis-diamminedichloroplatinum (II) by amphotericin B in vitro and in vivo

Human ovarian carcinoma cells (HRA) were sensitised to cis-diamminedichloroplatinum (II) (CDDP) 2.7-, 5.5- and 12.1-fold by treatment with amphotericin B (AMB) at concentrations of 2.1, 5.4 and 10.8 microM, respectively. Moreover, intracellular accumulation of platinum after a 2-h exposure to CDDP was increased significantly with AMB treatment. We prepared HRA cell-inoculated nude mice as an experimental therapeutic model for human advanced ovarian carcinoma. Ascites was evident after 7 to 9 days of intra-peritoneal (i.p.) inoculation of HRA cells, and mice died due to intra-abdominal carcinomatosis after 11 to 14 days [mean survival time (MST): 12.4 +/- 1.1 days]. Treatment with AMB (2.0 mg/kg) alone 4 days after inoculation increased MST by only 1.4 days. Simultaneous treatment with CDDP (1.0 to 2.0 mg/kg) and AMB (0.5 to 2.0 mg/kg) produced a significant increase in MST compared to treatment with CDDP alone. Maximal MST (30.1 days) was observed by treatment with 2.0 mg/kg CDDP plus 2.0 mg/kg AMB, whereas MST with 2.0 mg/kg CDDP alone was 16.4 days. A further drug accumulation study demonstrated that platinum accumulation in tumour tissues in nude mice treated with CDDP and AMB increased significantly compared to treatment with CDDP alone. These results indicate that intraperitoneal combination chemotherapy with CDDP and AMB is effective in an experimental animal model of advanced ovarian carcinoma.

Recurrence of epithelial ovarian carcinoma after clinical remission

One hundred and eighty-eight patients with epithelial ovarian carcinoma were treated with primary cytoreductive surgery and subsequent combination chemotherapy. The first recurrent findings such as sites and disease-free interval were analyzed in 141 patients who were clinically remitted 6 months after operation or chemotherapy. Fifty-seven cases had a recurrence. Five-year disease-free survival rates were 75, 72, 29, and 0% in stage I, II, III, and IV, respectively. Twenty-one of 22 patients with > 2 cm maximum residual tumor died, although they once achieved clinical remission. Significant differences were observed between histologic types, and the disease-free survival rate was lowest for serous cystadenocarcinoma. Nine of 15 stage IV patients with serous histology experienced remission, but none of the 8 in stage IV with other histologies did so, suggesting that serous adenocarcinoma is sensitive to chemotherapy and conducive to clinical remission. However, all stage IV patients in remission encountered a recurrence. Intra-abdominal cavity and lymph node were frequently the initial recurrent sites (38 and 27%, respectively). On the other hand, the incidence of distant recurrence was as high as 27%, and 8 of 16 cases with distant recurrence were stage I. Survival time after recurrence was not different among initial sites of recurrence and mean survival time was 15 months.

Glutathione related enzymes in cis-diamminedichloroplatinum (II)-sensitive and-resistant human ovarian carcinoma cells

A cis-diamminedichloroplatinum (II) (CDDP)-resistant cell line (NOS2CR) demonstrated 7.4-fold greater resistance to CDDP compared with the parental cell line (NOS2) established from a patient with serous cystadenocarcinoma of the ovary. We investigated the role of enzyme systems associated with glutathione (GSH) in these cell lines. The GSH content was almost identical in both cell lines. Preincubation with 50 microM DL-buthionine-S, R-sulfoximine (BSO), an inhibitor of gamma-glutamyl cysteine synthetase, for 24 hr reduced the IC50 in both NOS2 and NOS2CR cells. Glutathione-S-transferase pi (GST-pi) activity and mRNA level in NOS2CR cells were higher than in NOS2 cells. However, gamma-glutamyltranspeptidase (GGT) activity in NOS2CR cells was 2.4-fold less than in NOS2 cells. The GST activity and mRNA level in both cell lines were constant when the cells were exposed to CDDP. Exposure to CDDP for 48 hr increased the GGT mRNA level 4.4 and 1.8 times in NOS2 and NOS2CR cells, respectively, compared with no exposure. By exposure to CDDP for 48 hr, the GGT activities in NOS2 and NOS2CR cells were increased 1.6-and 2.5-fold, respectively, compared with no exposure. The above data provide the first evidence that GGT activity and GGT mRNA are induced by CDDP in human carcinoma cell lines.

Identification of two point mutations in the gene coding luteinizing hormone (LH) beta-subunit, associated with immunologically anomalous LH variants

To analyze the structure of LH in three patients with immunologically anomalous LH, the whole coding region of the LH beta-subunit gene was examined. These patients were infertile, and their serum LH levels could not be measured with an immunoassay kit. Immunoblotting of the LH beta-subunit showed no marked changes in the molecular size of LH beta. Genomic DNA was extracted from peripheral lymphocytes of the patients and normal controls, and LH beta genes were amplified by the polymerase chain reaction technique, using primer pairs that are capable of specifically amplifying only the LH beta gene without interference by the CG beta genes. No deletions were observed in the coding regions of the LH beta gene of the patients. Nucleotide sequencing revealed two nucleotide substitutions in the LH beta gene of the patients, which cause amino acid replacements from Trp8 (TGG) to Arg8 (CGG) and Ile15 (ATC) to Thr15 (ACC). Restriction fragment length polymorphism analysis in three families indicated that the affected probands were homozygous, and their family members were heterozygous, except for their husbands. The heterozygotes showed reduced detectability with the LH immunoassay kit. These results suggest that these amino acid replacements are responsible for this immunologically anomalous variant.

Positive correlation between cytochrome P450 2E1 mRNA level and serum estradiol level in human uterine endometrium

Most carcinogens are bioactivated by cytochrome P450s (CYPs) and these enzymes within target cells are closely related to susceptibility to cancer. Since extrahepatic CYPs occur typically at much lower levels, the existence and the role of CYP in extrahepatic tissues have been difficult to assess. In this study, we modified the reverse transcriptase-polymerase chain reaction (RT-PCR) to evaluate the relative quantities of CYP 2E1 mRNA in human endometrium. Total RNA from human endometrium was reverse-transcribed and co-amplified by PCR in the same tube containing both primer pairs of CYP 2E1 and beta-actin. The CYP 2E1 and beta-actin PCR products were 298 and 600 bp, respectively. The restriction enzyme MboI digested these two products to the predicted size for DNA fragments, demonstrating that both PCR products were specific and CYP 2E1 mRNA exists in human endometrium. CYP 1A1 mRNA was also examined, but could not be detected clearly. Adding [alpha-32P]dCTP to the reaction mixture made it possible to quantify the relative yield of the CYP 2E1 PCR product in comparison with the beta-actin product. The ratio of the yield of the CYP 2E1 PCR product to the beta-actin PCR product could be calculated at a point of 25 cycles of amplification. This ratio and serum estradiol levels were correlated positively (r = 0.654; p < 0.05), but no relationship to serum progesterone levels was observed.

[Studies of prognostic factor and chemotherapeutic effect of epithelial ovarian cancer using Cox's proportional hazard model]

To make clear the prognostic factor and chemotherapeutic effect of epithelial ovarian cancer, a multiple-center study involving 22 hospitals in Japan was conducted using Cox's proportional hazard model. A total of 1,181 cases were reviewed. Clinical stage, histologic type, and residual tumor diameter were significant prognostic factors, but the degree of tissue differentiation was not. The effect of remission induction chemotherapy was assessed with or without CDDP, and a distinct prognostic difference was noted. Among the patients receiving CDDP + ADM + other chemotherapeutic agents (PA group), CDDP + other chemotherapeutic agents (PO group) and CDDP only (P group), the prognosis of the PO group was better than for the P group. The long-term prognosis improving effect of chemotherapy was assessed. Neither maintenance chemotherapy based on oral administration of pyrimidine fluoride nor immunotherapy had any long-term prognosis improving effect, while intermittent chemotherapy based on CDDP resulted in improved prognosis.

[Determination of intrauterine pressure using catheter-tip transducer inserted outside fetal membranes]

To determining intrauterine pressure outside fetal membranes, we used a catheter-tip transducer to study 20 women before the occurrence membrane rupture. Their mean age was 28.2 +/- 3.4 years and all women were in weeks 37 to 41 of pregnancy when studied. In the first stage of labor, the peak intrauterine pressure was 60.0 +/- 12.5 mmHg (mean +/- SD) when the external os was dilated 4 to 6 cm, 90.0 +/- 14.8 mmHg, at 7 to 8 cm dilation, and 80.0 +/- 11.5 mmHg at 9 cm or greater dilation. Each pressure wave lasted 45 to 55 sec. The highest baseline pressure (28.0 +/- 4.5 mmHg) was obtained when the subjects were sitting. A baseline pressure of 17.0 +/- 4.0 mmHg was obtained in the supine position, as well as a value of 21.0 +/- 3.5 mmHg in the recumbent position. There were no complications related to the catheter-tip transducer. Our findings indicate that this method is both accurate and reliable in determining the amounts of intrauterine pressure to which fetal membranes are subjected.

Pregnancy after chemotherapy for trophoblastic diseases and psychosomatic development in the progeny

We treated 542 patients with trophoblastic diseases from 1965 through 1988, and succeeded in preserving fertility in 269 of them (240 cases of invasive mole and 29 cases of choriocarcinoma). Of the 269 patients, 198 (79.5%) conceived after completing treatment. A total of 396 pregnancies in these women resulted in 295 term live births (74.5%), 51 spontaneous abortions (12.9%), and 4 recurrences of moles (1.0%). Four cases (1.32%) of malformations were discovered. The growth conditions of 101 children born in 1976 or later were followed up until the age of 18 months. Their heights or weights did not differ significantly from those of children measured in national infantile-growth surveys. The psychoneurological development of 54 children up to the age of 7 years who were studied by using infantile mental-development questionnaires showed no marked mental retardation. Our results provide strong evidence of the safety of chemotherapy for the treatment of trophoblastic diseases.

Identification of the pregnancy responsible for gestational trophoblastic disease by DNA analysis

In three cases of choriocarcinoma, genetic loci including a variable number of tandem repeat regions were amplified by the polymerase chain reaction method on DNA from three established cell lines and from lymphocytes of patients and their husbands to identify the responsible pregnancy. Case 1, from whom NaUCC-3 was derived, had only one full-term fetal death. Case 2, from whom NaUCC-4 was derived, had one normal delivery followed by one complete molar delivery and one normal delivery. Case 3, from whom NaUCC-2 was derived, had one normal delivery followed by one complete molar delivery. In case 1, NaUCC-3 was found to be of parental origin and derived from the pregnancy with full-term fetal death. In cases 2 and 3, NaUCC-4 and NaUCC-2 were of probable androgenetic origin and were derived from the pregnancy with complete hydatidiform mole. We also conducted the restriction fragment length polymorphism method using case 1 samples, and it confirmed the results based on the polymerase chain reaction method product patterns. All nine cases of hydatidiform mole and three cases of invasive mole were of androgenetic origin. The polymerase chain reaction method thus makes it possible to identify easily the pregnancy responsible for choriocarcinoma using only a few specimens without isotopes.

Possible action of human placental aminopeptidase N in feto-placental unit

Aminopeptidase N purified from human placenta actively hydrolyzed various immunomodulating peptides from their N-terminus such as splenopentin, thymopentin, thymic humoral factor gamma 2, tuftsin and rigin in vitro. Aminopeptidase N also actively hydrolyzed neuropeptide hormones (met-enkephalin, somatostatin and neurokinin A) and vasoactive peptides (lysyl-bradykinin and angiotensin III) from their N-terminus. In addition, angiotensin II, secretin, thymopoietin II peptide fragment, motilin, endothelin-I and insulin were tested for hydrolysis by aminopeptidase N. Km and Vmax values for the N-terminal amino acid, Thr, a liberation from tuftsin were 267 microM and 8.33 mumol/min/mg protein, respectively. L-Leucyl-p-nitroanilidase activity in the human placental membrane fraction was almost completely neutralized by anti-aminopeptidase N antibody. Our present study suggests that possible roles for surface enzyme aminopeptidase N in the human placenta would be to down-regulate the action of immunomodulating peptides as well as vasoactive and neuropeptide hormones, and to control both immunology and endocrinology of pregnancy.