The impact of chorioamnionitis on neurodevelopmental outcomes at 3, 8 and 18 years in low-birthweight preterm infants.

OBJECTIVE: To assess the long-term cognitive, behavioral and academic status of preterm children exposed to clinical chorioamnionitis. STUDY DESIGN: In total, 985 infants (<37 weeks and 2500 g at birth) were recruited in a multisite interventional research program. Of these, 43 case-infants were identified based on documented diagnosis of maternal clinical chorioamnionitis. Infants with chorioamnionitis were compared with the remainder of the cohort after controlling for maternal and infant variables. All infants underwent cognitive, behavioral and academic achievement assessments at 3, 8 and 18 years. Standardized cognitive and academic achievement scores were cutoff at 2 s.d.'s below the mean, behavioral scores were cutoff at a T-score >70 and examined with χ(2) statistics. Mean scores were evaluated using preliminary bivariate analysis and were followed by multiple regression models predicting child outcomes. RESULT: Overall, children with chorioamnionitis did not have lower scores on any assessment at any age. Children without chorioamnionitis performed significantly lower at 8 years on the Woodcock-Johnson reading subscore and the mean score of the Peabody Picture Vocabulary Test (PPVT). No significant difference persisted to 18-year follow-up. In logistic regression, chorioamnionitis independently predicted higher PPVT scores at 8 years, but not lower performance scores on the Woodcock-Johnson reading subscore. CONCLUSION: Clinical chorioamnionitis was not associated with adverse neurodevelopmental outcomes in this group of preterm infants <37 weeks and 2500 g.

Analysis of ovarian gene expression in follicle-stimulating hormone beta knockout mice.

FSH is a heterodimeric glycoprotein hormone that is produced in the gonadotroph cells of the anterior pituitary. It acts on Sertoli cells of the testis and granulosa cells of the ovary. We previously demonstrated that FSHbeta knockout female mice are infertile due to a block in folliculogenesis preceding antral stage development. To investigate aberrations of ovarian gene regulation in the absence of FSH, we analyzed the expression of several important marker genes using Northern blot and in situ hybridization techniques. Key findings are as follows: 1) Follicles of FSHbeta knockout mice develop a well organized thecal layer, which is positive for P450 17alpha-hydroxylase and LH receptor messenger RNAs (mRNAs). This indicates that theca recruitment is completed autonomously with respect to FSH. 2) Granulosa cells in FSH-deficient mice demonstrate an increase in FSH receptor mRNA, and decreases in P450 aromatase, serum/glucocorticoid-induced kinase, and inhibin/activin subunit mRNAs. These data support studies that implicate FSH signaling cascades in the expression of these genes. 3) In contrast to the thecal layer, granulosa cell populations in FSHbeta knockout mice do not accumulate LH receptor mRNA. This suggests that although the granulosa cells have a block in proliferation at the antral follicle stage in the absence of FSH, they do not initiate programs of terminal differentiation as seen in luteinizing cells of wild-type ovaries. 4) Ovaries of FSH-deficient mice demonstrate a modest decrease in cyclin D2 mRNA, without up-regulation of cell cycle inhibitor mRNAs associated with luteinization (i.e. p15, p27, and p21). Although components of the FSH null phenotype may be caused by partial cyclin D2 loss of function, these findings indicate that the mechanisms of granulosa cell cycle arrest in FSHbeta knockout mice are distinct from those of cycle withdrawal at luteinization. Underscoring the usefulness of the FSH-deficient mouse model, this study clarifies aspects of gonadotropin-dependent folliculogenesis, thecal layer development, cycle control in granulosa cells, and luteinization.

Inhibin and p27 interact to regulate gonadal tumorigenesis.

Tumor suppressors function as antiproliferative signaling proteins, and defects in these genes lead to uncontrolled cell proliferation and cancer. For example, absence of the tumor suppressor p27(Kip1), a cyclin-dependent kinase inhibitor (CKI), results in increased body size, hyperplasia of several organs including the testes, and cancer in mice. Similarly, lack of inhibins, alpha/beta heterodimeric members of the transforming growth factor-beta (TGFbeta) superfamily, causes testicular and ovarian tumors of the granulosa/Sertoli cell lineage beginning at 4 weeks of age and adrenal tumors in gonadectomized mice. Neither the cell cycle alterations in the absence of inhibin nor the cause of the increased testis size in the p27 knockout mice is known. To study the molecular (cell cycle) changes that result from absence of inhibins, we analyzed the regulation of cell cycle proteins in gonadal tumors derived from inhibin alpha knockout mice (Inha(-/-)). Northern blot analyses demonstrate that cyclin-dependent kinase 4 (Cdk4) and cyclin D2 mRNA levels are elevated, and immunohistochemistry shows that p27 protein levels are decreased in both ovarian and testicular tumors from Inha(-/-) mice. These findings suggest that increased Cdk4/cyclin D2 (positive) activity and decreased p27 (negative) activity is causal for gonadal tumor formation. To test this hypothesis, we generated double mutant mice lacking both p27 and inhibin alpha to determine whether the tumor suppressors p27 and inhibin have additive suppressor activity in the gonads. Like Inha(-/-) mice, p27(-/-)Inha(-/-) mice demonstrate elevated serum activin levels, ovarian and testicular tumors, and a resultant lethal cachexia-like syndrome. However, whereas 95% of the Inha(-/-) female mice die by 18 weeks of age, 100% of the p27(-/-)Inha(-/-) female mice are dead by 8 weeks. Similarly, 95% of the Inha(-/-) single mutant males die by 13 weeks while 100% of the p27(-/-)Inha(-/-) male mice die by 10 weeks. Moreover, tumor foci in p27(-/-)Inha(-/-) mice can be observed as early as 2 weeks of age in males and as early as 4 weeks in females. These findings demonstrate that absence of both inhibin and p27 in mice causes earlier development of ovarian and testicular tumors and earlier death compared with absence of inhibin alone.