Augmentation of leptin and hypoxia-inducible factor 1alpha mRNAs in the pre-eclamptic placenta

The placenta is a major source of leptin in the fetomaternal circulation, although its physiological role remains to be clarified. Leptin in the fetomaternal circulation is proposed to be a marker of acute stress in the fetus, and the fetus suffering from pre-eclampsia would be under chronic stress. In 16 pre-eclamptic placentas, the expressions of leptin, hypoxia-inducible factor 1alpha (HIF1alpha) and leptin receptor mRNAs were analyzed by semi-quantitative reverse-transcriptase-polymerase chain reaction and compared with clinical data. The co-expressions of leptin and the isoforms of the leptin receptor were observed in all the pre-eclamptic placentas. Leptin mRNA was significantly augmented in the pre-eclamptic placentas, although the level in fetal plasma was not high. The level of the expression of leptin mRNA was correlated with the placental HIF1alpha mRNA level and fetal body weight, but not with the levels of the leptin receptor isoforms in the pre-eclamptic placentas. This observation may suggest that autocrine/paracrine regulation of leptin exists in the human placenta and is upregulated in the pre-eclamptic placenta.

Uterine contractions increase fetal heart preload

OBJECTIVE

The preload index (PLI) has been shown to increase in the recipient fetus of twin-twin transfusion syndrome in the presence of uterine contractions. The objective of this study was to determine whether there are changes in PLI in the presence of uterine contractions in normal fetuses.

METHODS

Inferior vena cava blood flow was measured using Doppler sonography in 45 normal fetuses at 18-41 weeks' gestation in the presence of uterine contractions and during quiescence and the PLI was compared between groups.

RESULTS

There was a highly significant difference (P < 0.0001) between the mean +/- SD PLI in fetuses in the absence (0.235 +/- 0.07) and in the presence (0.534 +/- 0.183) of uterine contractions.

CONCLUSION

Uterine contractions appear to increase fetal preload conditions in normal pregnancy.

Coexpression of growth arrest-specific gene 6 and receptor tyrosine kinases, Axl and Sky, in human uterine endometrium and ovarian endometriosis

We demonstrated the expression of Gas6, the protein product of the growth arrest-specific gene 6 (gas6) and a member of the vitamin K-dependent protein family, and its receptor tyrosine kinases, Axl and Sky, in human uterine and ovarian endometriotic endometria using RT-PCR-Southern blot analysis and immunohistochemistry. Gas6, Axl and Sky mRNA were detected in all samples analysed. There was no significant difference between the levels of Sky mRNA in normal uterine and endometriotic endometria; however, the levels of Gas6 and Axl mRNA in endometriotic endometria were significantly higher than in normal endometria. These mRNA levels showed no significant alteration during the menstrual cycle. In the immunohistochemical study, Gas6, Axl and Sky were found in endometrial glandular cells and stromal cells in all samples analysed. This study demonstrates the coexpression of receptor tyrosine kinases and their ligand, Gas6, in normal uterine and ovarian endometriotic endometria, and the overexpression of Axl and Gas6 in endometriotic endometria. It is suggested that Gas6 and Axl signal transduction is aberrantly stimulated in endometriotic endometria, and is plausibly related to its growth potential.

Leiomyoma of the fallopian tube

Leiomyomas of the fallopian tube are rare. They are typically incidental findings seen at autopsy or unrelated surgical procedures. A 32-year-old woman presented with lower abdominal pain and mass. Transvaginal sonogram and magnetic resonance imaging showed the solid mass at the outside of the uterus. At surgery, the left fallopian tube contained a firm mass with torsion in the area of the ampullary-isthmic junction. The left tube and the infundibulopelvic ligament were rolled in torsion and showed edematous change. We report a rare case in whom torsion of a pedunculated tubal leiomyoma caused abdominal pain.

Dominant expression of progesterone receptor form B mRNA in ovarian endometriosis

This study was designed to examine the biological implications of progesterone receptor form A (PR-A) and B (PR-B) mRNA expressions in human ovarian endometriosis (ectopic endometrium). A high ratio of PR-B to PR-AB (PR-A+PR-B) mRNA expression was found in 8 of 14 cases of endometriosis, compared with the ratio in eutopic endometrium. The mean ratio in ectopic endometria was significantly (p < 0.01) higher than in eutopic endometria. The ratio in eutopic and ectopic endometria showed no significant change during the menstrual cycle. The mean ratio in ectopic endometria in the proliferative and secretory phases of the endometrium was significantly (p < 0.01) higher than in eutopic endometria. In conclusion, PR-B mRNA was relatively highly expressed in some endometriomas, which might lead to aberrations in the control of progestational effects involving responsiveness to sex steroidal growth regulation.

Identification of exon-deleted progesterone receptor mRNAs in human uterine endometrial cancers

We demonstrated the expression of various exon-deleted progesterone receptor (PR) variant mRNAs in human uterine endometrial cancers using the reverse transcription-polymerase chain reaction-DNA sequencing analyses. In addition to PR wild-type mRNA, exon 4-deleted, exon 6-deleted, exon 3,4-deleted, exon 5,6-deleted, exon 4,5,6-deleted and exon 3,4,5,6-deleted PR variant mRNAs were identified. The exon 6-deleted and exon 5,6-deleted PR variant mRNAs lacked encoding for the steroid-binding domain. The exon 4-deleted, exon 3,4-deleted, exon 4,5,6-deleted and exon 3,4,5,6-deleted PR variant mRNAs lacked encoding for the DNA-binding domain in addition to encoding for the steroid-binding domain. While the exon 4-deleted, exon 6-deleted and exon 3,4-deleted PR variant mRNAs were observed in all samples analyzed, the exon 5,6-deleted, exon 4,5,6-deleted and/or exon 3,4,5,6-deleted PR variant mRNAs could not be detected in some cases, especially in poorly differentiated adenocarcinoma as compared with well-differentiated and moderately differentiated adenocarcinomas. The present study demonstrates the coexpression of PR exon-deleted variant mRNAs with the wild-type in uterine endometrial cancers. All translated variant proteins might possess functional diversity and might modify the progestational action of wild-type PR, and the expression of some PR variant mRNAs may be lost as endometrial cancer cells undergo dedifferentiation.

Evidence for the synthesis of corticosteroid-binding globulin in human placenta

We demonstrated the expression of corticosteroid-binding globulin (CBG) in human placenta using reverse transcription-polymerase chain reaction-Southern blot analysis and immunohistochemical and immunoblotting studies. In the RT-PCR-Southern blot analysis, only one predicted PCR product was detected without nonspecific products in all samples of human placenta and 3A (tPA-30-1) human placental cells. In Western blot analysis, polyclonal anti-CBG antibodies recognized a protein of approximately 55 kD in the protein extracts prepared from 3A (tPA-30-1) cells. Additionally, CBG mRNA expression was demonstrated by in situ hybridization in the syncytiotrophoblasts. Immunohistochemical studies performed on the placenta demonstrated the presence of specific immunoreactivity in the syncytiotrophoblast layer surrounding the chorionic villi. These findings suggest that CBG is synthesized in human placenta during pregnancy in addition to its synthesis in the liver.

Levels of corticosteroid-binding globulin mRNA in human ovarian cancers

To understand the role of corticosteroid-binding globulin (CBG) in the intracellular steroidal actions in human ovarian cancers, the level of CBG mRNA expression was evaluated in normal ovarian tissues and in ovarian cancers using competitive reverse transcription-polymerase chain reaction-Southern blot analysis. The expression of CBG mRNA was detected in all normal ovaries and ovarian cancers analyzed. There were no significant differences in the mean CBG mRNA levels between normal ovaries and ovarian cancers. The expression in normal ovaries was significantly higher (p < 0.01) in the premenopause than in the postmenopause. A high expression of CBG mRNA was observed in 11 out of 29 cases (38%) of ovarian cancer in comparison with normal ovaries. There was no difference in the expression among the histological classifications or clinical stages of ovarian cancers. These data suggest that human normal ovaries and ovarian cancers might synthesize CBG intracellularly, ovarian cancers might conserve a progesterone-associated property via CBG, and the regulation of intracelluar CBG expression might be changed in some cancers.

Reproducibility of the oxygen uptake efficiency slope in normal healthy subjects

BACKGROUND

To elucidate the intertest agreement of the oxygen uptake efficiency slope (OUES) in comparison with those of the maximal oxygen uptake (VO2max) and the ventilatory anaerobic threshold (VAT).

METHODS

EXPERIMENTAL DESIGN

A comparative study.

SETTING

Institutional practice. A total of 19 healthy volunteers underwent two sessions of maximal exercise testing with an interval of no more than 7 days. The testing was conducted on a cycle ergometer with the work rate increased by either 20, 30, or 40 Watts (W)/min so that the subject would reach exhaustion within 9 to 12 min of exercise. VAT was defined as the level of oxygen uptake (VO2) at which either an increase in the ventilatory equivalent for oxygen without a concomitant increase in the ventilatory equivalent for carbon dioxide or a change in the slope of the linear relationship between carbon-dioxide production (VCO2) and VO2 occurred. OUES was determined by the following equation: VO2 = a log VE + b, where VE was minute ventilation and "a" was the OUES. Intertest reproducibility was assessed by coefficient of repeatability (COR).

RESULTS

The intertest reproducibility of VO2max and OUES were excellent (COR = 570 ml/min [16%] and 740 [20%], respectively). VAT showed poor agreement between the two tests (COR = 650 ml/min [31%]).

CONCLUSIONS

Results show that OUES is reproducible and reliable, supporting the clinical usefulness of this index.

Levels of sex hormone-binding globulin and corticosteroid-binding globulin mRNAs in corpus luteum of human subjects: correlation with serum steroid hormone levels

To understand regulation of the function of human ovarian corpus luteum by sex steroid-binding proteins, the levels of luteal intracellular sex hormone-binding globulin (SHBG) and corticosteroid-binding globulin (CBG) mRNAs and serum steroid hormones were simultaneously determined. The expression of SHBG and CBG mRNAs was detected in all samples analyzed. SHBG mRNA level was positively correlated with serum estradiol-17 beta level (p < 0.05), but not with serum progesterone level. There was a positive correlation between SHBG mRNA level and serum estradiol-17 beta/progesterone ratio (p < 0.01). On the other hand, CBG mRNA level was positively correlated with serum estradiol-17 beta and progesterone level (p < 0.01 and p < 0.01, respectively). There was no correlation between CBG mRNA level and serum estradiol-17 beta/progesterone ratio. SHBG and CBG mRNA levels were not correlated with the levels of serum testosterone, free testosterone or cortisol. These findings suggest that the synthesis of luteal SHBG and CBG is complexly regulated by estrogen and progesterone, and that SHBG and CBG interact with estrogen and progesterone, respectively, for luteal steroidal activity.

Expression of sex hormone-binding globulin exon 7 splicing variant mRNA in secondary spreading lesions of gynecological cancers

This study was designed to determine the clinical implications of intracellular expression of sex hormone-binding globulin (SHBG) wild-type and exon 7 splicing variant mRNAs in secondary spreading lesions of gynecologic cancers using the reverse transcription-polymerase chain reaction-Southern blot and DNA sequencing analyses. Compared with primary cancers, a relative increase in SHBG variant mRNA to wild-type mRNA expression was observed (4/10 cases of uterine endometrial cancers, 5/10 cases of uterine cervical cancers, 6/10 cases of ovarian cancers) or the expression of SHBG wild-type and variant mRNAs could not be detected (5/10 cases of uterine endometrial cancers, 3/10 cases of uterine cervical cancers, 4/10 cases of ovarian cancers). On the other hand, alteration to a relative increase in SHBG wild-type mRNA expression in the metastatic lesions occurred in only 3 cases (1/10 cases of uterine endometrial cancers and 2/10 cases of uterine cervical cancers) analyzed. These results suggest that the transcription of SHBG mRNA and the regulation of its splicing might be altered with metastatic potential, and this status might be involved in a change in steroidal dependency of metastatic lesions.

Expression of oestrogen receptor alpha and beta mRNA in corpus luteum of human subjects

To investigate the role of oestrogen receptor beta (ERbeta) in the function of human ovarian corpus luteum, the levels of luteal ERalpha and ERbeta mRNA were determined using competitive reverse transcription-polymerase chain reaction-Southern blot analysis. The expression of ERalpha and ERbeta mRNA was detected in all luteal samples analysed. Luteal ERalpha and ERbeta mRNA levels were significantly lower (P<0.01 and P<0.05 respectively) at the late secretory phase than those at the early and mid-secretory phases of the endometrium. The ratio of ERalpha to ERbeta mRNA levels showed no change during the secretory phase of the endometrium. This study demonstrates that ERbeta is co-expressed with ERalpha in human corpus luteum and is likely to play a biological role in the regulation of steroidal action of the corpus luteum with ERalpha.

Identification of various exon-deleted progesterone receptor mRNAs in human endometrium and ovarian endometriosis

We demonstrated the expression of various exon-deleted progesterone receptor (PR) variant mRNAs in human uterine endometrium and ovarian endometriosis using the reverse transcription-polymerase chain reaction-DNA sequencing analyses. In addition to PR wild-type mRNA, various exon-deleted PR variant mRNAs were identified in all samples analyzed. The sequence of these variants showed a perfect junction between exons surrouding the deletion area. PR wild-type, exon 6-deleted, exon 4-deleted, exon 5, 6-deleted and exon 4, 5, 6-deleted PR variant mRNAs were observed in all samples analyzed. Exon 4, 6-deleted PR mRNA was observed only in ovarian endometriosis. This is the first study to demonstrate the coexpression of various PR exon-deleted variant mRNAs with the wild-type in uterine endometrium and ovarian endometriosis. All resulting variant proteins might indicate functional diversity and modify the progestational action of wild-type PR, and thus be involved in the pathophysiology of ovarian endometriosis.

Expression of progesterone receptor isoforms in corpora lutea of human subjects: correlation with serum oestrogen and progesterone concentrations

To understand the biological significance of progesterone receptor forms A (PR-A) and B (PR-B) in human corpus luteum, the expression of mRNA and serum steroid hormone concentrations were determined simultaneously in the luteal stages. The expression of PR-A mRNA predominated over PR-B mRNA in all samples analysed. Total PR (PR-AB) and PR-B mRNA concentrations at the late secretory phase were significantly (P < 0.01) lower than those at the early and mid secretory phases of the menstrual cycle. The ratio of PR-B to PR-AB mRNA concentration showed no significant change during the secretory phase. In the early and mid secretory phases, there was a negative correlation between PR-B mRNA concentration and serum progesterone concentration, and between the ratio of PR-B to PR-AB mRNA concentrations and serum progesterone concentration (P < 0.01). These findings suggest that human corpus luteum might intracellularly synthesize PR-A and PR-B, and thus be involved in the steroid functional regulation of the corpus luteum, especially at the early and mid secretory phases, and that progesterone might regulate the synthesis of PR-A and PR-B.

Dominant expression of sex-hormone-binding-globulin exon-7 splicing variant over wild-type mRNA in human ovarian cancers

The intracellular expression of sex-hormone-binding-globulin(SHBG) exon-7-splicing-variant mRNA in human ovarian cancers was demonstrated by reverse-transcription/polymerase-chain-reaction, Southern-blot and DNA-sequencing analyses. Analysis of the missing base pairs proved that they corresponded to the entire exon 7, which is considered to encode a portion of the steroid-binding site, suggesting that the steroid-binding affinity of this variant might be different from that of the SHBG wild type. SHBG wild-type and variant mRNA was detected in all normal ovaries and in benign and malignant ovarian tumors analyzed. There were no significant differences in mean SHBG wild-type and variant mRNA levels among the 3 types of tissue, but the ratio of SHBG exon-7-splicing-variant to wild-type mRNA level in ovarian cancers was significantly higher (p < 0.05) than that in normal ovaries, with over-expression in some benign tumors. SHBG mRNA levels and the ratio of SHBG variant to wild-type mRNA was not associated with histological classification or clinical stages of ovarian cancers. These results suggest that over-expression of SHBG-exon 7-splicing-variant mRNA to the wild type might indicate the potential for neoplastic transformation.