Crim1 has an essential role in glycogen trophoblast cell and sinusoidal-trophoblast giant cell development in the placenta.

Normal placental development and function is essential for fetal growth of eutherian mammals. Mutational studies have shown that numerous growth factors are required for placental development and differentiation of placental lineages. Here, using a gene-trap mutant mouse line, Crim1(KST264), we show that Crim1 is essential for murine placental development. Crim1 is a developmentally expressed, trans-membrane regulator of growth factor activity. Crim1(KST264/KST264) mutant placentae displayed hypoplasia from 13.5 dpc, and altered structure from 15.5 dpc, including alterations in cell number in both the junctional and labyrinth zones. Using the reporter gene from the Crim1(KST264) allele, we found that Crim1 is expressed in multiple cell types of the placenta, including strong expression in the spongiotrophoblast cells of the junctional zone. In the junctional zone of Crim1(KST264/KST264) placentae, there was an increase in the glycogen trophoblast cells adjacent to the spongiotrophoblast cells. In the labyrinth zone, we found a decrease in the density of sinusoidal-trophoblast giant cells. Our findings show that Crim1 is required for placental development, and is necessary for the proper differentiation of sinusoidal-trophoblast giant cells and glycogen trophoblast cells.

Expression and functional analysis of Dkk1 during early gonadal development.

WNT signalling plays a central role in mammalian sex determination by promoting ovarian development and repressing aspects of testis development in the early gonad. Dickkopf homolog 1 (DKK1) is a WNT signalling antagonist that plays critical roles in multiple developmental systems by modulating WNT activity. Here, we examined the role of DKK1 in mouse sex determination and early gonadal development. Dkk1 mRNA was upregulated sex-specifically during testis differentiation, suggesting that DKK1 could repress WNT signalling in the developing testis. However, we observed overtly normal testis development in Dkk1-null XY gonads, and found no significant upregulation of Axin2 or Sp5 that would indicate increased canonical WNT signalling. Nor did we find significant differences in expression of key markers of testis and ovarian development. We propose that DKK1 may play a protective role that is not unmasked by loss-of-function in the absence of other stressors.

Expression of metanephric nephron-patterning genes in differentiating mesonephric tubules.

The metanephros is the functional organ in adult amniotes while the mesonephros degenerates. However, parallel tubulogenetic events are thought to exist between mesonephros and metanephros. Mesonephric tubules are retained in males and differentiate into efferent ducts of the male reproductive tract. By examining the murine mesonephric expression of markers of distinct stages and regions of metanephric nephrons during tubule formation and patterning, we provide further evidence to support this common morphogenetic mechanism. Renal vesicle, early proximal and distal tubule, loop of Henle, and renal corpuscle genes were expressed by mesonephric tubules. Vip, Slc6a20b, and Slc18a1 were male-specific. In contrast, mining of the GUDMAP database identified candidate late mesonephros-specific genes, 10 of which were restricted to the male. Among the male-specific genes are candidates for regulating ion/fluid balance within the efferent ducts, thereby regulating sperm maturation and genes marking tubule-associated neurons potentially critical for normal male reproductive tract function.

Small bowel perforation after radiotherapy for cervical carcinoma.

Radiotherapy is the treatment of choice for carcinoma of the uterine cervix. We report on a 62-year-old Chinese woman with cervical carcinoma, in whom a small bowel perforation developed 5 months after radiotherapy. Ten centimetres of small bowel, including the perforation site, were resected. No bowel adhesion was detected during the operation. The postoperative course was uneventful, and the patient was discharged home 7 days after surgery. Histological examination confirmed post-irradiation injury. The presenting complaints of patients with bowel perforation following radiotherapy vary, and signs of peritonitis may be absent. Emergency physicians must be alert for these complications in patients who have been treated with radiotherapy.

Regionalization of infant transports: the southern California experience and its implications. I: Referral pattern.

The development and implementation of neonatal intensive care services have been essential components of perinatal regionalization during the past two decades. The transport of critically ill infants to regional neonatal intensive care units has played an important role in improving neonatal outcome. This article presents a profile of Southern California's 10-year infant transport experience (1979 through 1988) in terms of the following indicators: transport volume, cross-county referrals, distance travelled, referral pattern, and birth weight pattern. Findings point to the necessity of focusing attention on several critical issues confronting Southern California's neonatal services in the 1990s. They include adequacy of tertiary or intermediate bed capacity in neonatal intensive care units; appropriateness of existing infant referral practices; impact of maternal-fetal transports; availability of financing resources; and overall differences in morbidity and mortality rates between transported and nontransported infants in subpopulations.

Hyalinizing trabecular adenoma-like lesion in multinodular goitre.

Hyalinizing trabecular adenoma, a recently characterized variant of thyroid adenoma, is often confused with a variety of lesions because of its unusual histological features (Carney, Ryan & Goellner 1987). We report a case of multinodular goitre in which there were several small nodules showing features of hyalinizing trabecular adenoma and peculiar nuclear rods.

Post-traumatic fat embolism--its clinical and subclinical presentations.

A prospective study of post-traumatic fat embolism among a group of Chinese patients suffering from fractures demonstrated an incidence of 8.75% in fracture patients with overt clinical features and a mortality rate of 2.5%. In a multiple-fracture group the incidence of fat embolism was 35%. The significant findings of 64% of the patients with a low arterial pO2 and 52% with positive cryostat tests for fat globules suggested a high incidence of subclinical presentation. The presence of large vacuoles in the cryostat sections is demonstrated and its significance discussed. The 'iceberg' phenomenon of fat embolism syndrome should be well recognized, particularly in patients with multiple fractures.