Focus on psychometrics. Aggregating family data.

Instruments to collect data about families are often administered to all or some individuals within the family. Researchers may wish to use these individual scores to describe the family. The purpose of this article is to describe the special issues with aggregation of data when only a small number of family members are used as respondents. A refinement of the definition of aggregation for family researchers is proposed to assist researchers to focus on specific issues when data are to reflect subgroups within the family. A few examples of changes in findings are reported to illustrate the effects of different aggregation schemes when two members of the family are used as respondents.     

Luteinizing hormone-beta mRNA levels are regulated primarily by gonadotropin-releasing hormone and not by negative estrogen feedback on the pituitary

Long-term effects of gonadotropin-releasing hormone (GnRH) and/or estrogen on pituitary mRNA levels for the beta-subunit of luteinizing hormone (LH-beta) were determined in anterior pituitary glands from ovariectomized (OVX) ewes. The relative roles of these two factors were assessed by studying hypothalamopituitary disconnected (HPD) ewes with appropriate hormonal treatments. Levels of LH-beta mRNA were increased by ovariectomy and substantially reduced by HPD. Treatment of OVX-HPD ewes with pulses of GnRH (250 ng each 2 h) for 1 week restored LH-beta mRNA levels to OVX levels, whereas treatment with estrogen alone did not alter the low levels found in OVX-HPD ewes. Combined GnRH and estrogen treatment for one week produced LH-beta mRNA levels that were similar to those found in OVX-HPD ewes given GnRH alone; plasma LH pulse amplitudes were also similar in these two groups. From these data we conclude that the long-term negative feedback effect of estrogen to reduce LH secretion is due to a primary inhibition of GnRH secretion and is not a pituitary effect of estrogen. Long-term regulation of LH-beta mRNA is thus primarily regulated by GnRH.     

Gastroschisis: ultrasonographic diagnosis, perinatal embryology, surgical and obstetric treatment and outcomes

The embryology and onset time of gastroschisis are poorly understood. This paper reviews 22 cases of the condition seen at the Children's Hospital of Eastern Ontario between 1975 and 1986. Sixteen cases were judged to be of the perinatal and 6 of the early type. Ultrasonography revealed the actual time of development in one case and the probable time in another. In 20 cases the defect was closed primarily and in 2 by a staged procedure (Silon pouch). Nineteen infants (86.4%) survived. In all cases the umbilical vasculature was normal and all were right-sided. Other anomalies were rare and less important. Two clear examples of rupture of the umbilical ring are documented. Ultrasonography had been performed in 10 infants, usually for intrauterine growth retardation, and gastroschisis was diagnosed in 4 of these. Delivery was by cesarean section in six. Marked meconium staining occurred in 16 (73%), 7 of whom had subglottic aspiration of meconium. The average birth weight was 2480 g. Ultrasonography is recommended in all cases of intrauterine growth retardation with careful examination of the umbilical area to establish the presence and time of onset of gastroschisis. Vaginal delivery appears to be the route of choice for delivery.     

Radon dosimetry based on the depth distribution of nuclei in human and rat lungs

Calculation of the absorbed dose by different lung cells is necessary for predicting the critical cells that are subject to injury from inhaled Rn and other alpha-particle sources. The absorbed dose was determined for cells in the airways of human and rat lungs, based on airway epithelial thickness and on cell cytoplasm and nuclear volume density as a function of depth from the luminal surface of the airway epithelium. The thickness of the stratified columnar epithelium of human airways varied from 57.8 micron in bronchi to 9.8 microns in bronchioles. The cell populations of all bronchi in human lungs were comparable. The cell populations of trachea and intrapulmonary airways in rats, however, were significantly different. Basal cell populations in rat trachea and human bronchi were similar and formed a nearly continuous layer. In rat bronchi, basal cells were not present in significant numbers. Measurements of epithelial thickness and volume density were used to estimate the absorbed dose for an alpha-particle source (214Po or 218Po) distributed uniformly in the mucus with an equivalent activity of 1 dpm per cm2 of epithelial surface. The following model predictions of dose to human bronchial epithelial cell nuclei for a 218Po alpha-particle source are provided in units of nanogray (nGy) for specific cell types: secretory 158, preciliated 114, ciliated 44, goblet 86, basal 78, and indeterminate cell nuclei 73. The absorbed dose to specific types of rat bronchial epithelial cell nuclei was also predicted: secretory 237, precillated 216, ciliated 203, goblet 204, basal 200, and indeterminate cell nuclei 166 nGy. These and other results indicate that human and rat airway dosimetry have significant differences that may contribute to the differences in cancer cell induction between the two species.     

Term delivery in a woman with severe congenital neutropenia, treated with growth colony stimulating factor

The patient was diagnosed in childhood as having severe congenital neutropenia and had recurrent admissions with severe infections. In 1987, prior to getting married, she was sterilized. She continued to require i.v. antibiotics when she contracted a severe infection. On one occasion, she was treated with growth colony stimulating factor (G- CSF). Her increased neutrophil count was sustained following this treatment. In June 1993, she wished to start a family and underwent in- vitro fertilization (IVF) treatment. G-CSF was given prior to oocyte retrieval. She conceived on her first cycle and an ultrasound scan revealed a singleton pregnancy. Throughout the course of the pregnancy, her white cell count was monitored closely and remained at <1.0x10(9)/l. The pregnancy progressed uneventfully and at 37 weeks gestation she was admitted for G-CSF injections. At 38 weeks she was delivered of a boy weighing 3350 g, by elective Caesarean section. His white cell count was normal. This is the first case of G-CSF being used before conception and during pregnancy in a patient with congenital neutropenia. It shows that advances in cytokine therapy and close interdisciplinary liaison can lead to a successful outcome and help patients, who would otherwise remain childless, to achieve a family.      

Distribution of spermatogenesis in the testicles of azoospermic men: the presence or absence of spermatids in the testes of men with germinal failure [published erratum appears in Hum Reprod 1998 Mar;13(3):780]

The aim of the study was to determine whether a prior diagnostic testicle biopsy can predict success or failure of testicular sperm extraction (TESE) with intracytoplasmic sperm injection (ICSI) in patients with non-obstructive azoospermia caused by testicular failure, and what is the minimum threshold of sperm production in the testis which must be surpassed for spermatozoa to reach the ejaculate. Forty- five patients with non-obstructive azoospermia caused by testicular failure underwent diagnostic testicle biopsy prior to a planned future TESE-ICSI procedure. The diagnostic testicle biopsy was analysed quantitatively, and correlated with the quantitative findings of spermatogenesis in patients with normal spermatogenesis, as well as with the results of subsequent attempts at TESE-ICSI. Men with non- obstructive azoospermia caused by germinal failure had a mean of 0-6 mature spermatids/seminiferous tubule seen on a diagnostic testicle biopsy, compared to 17-35 mature spermatids/tubule in men with normal spermatogenesis and obstructive azoospermia. These findings were the same for all types of testicular failure whether Sertoli cell only, maturation arrest, cryptorchidism, or post-chemotherapy azoospermia. Twenty-two of 26 men with mature spermatids found in the prior testis biopsy had successful retrieval of spermatozoa for ICSI, 12 of their partners became pregnant, and are either ongoing or delivered. The study suggests that 4-6 mature spermatids/tubule must be present in the testis biopsy for any spermatozoa to reach the ejaculate. More than half of azoospermic patients with germinal failure have minute foci of spermatogenesis which are insufficient to produce spermatozoa in the ejaculate. Prior diagnostic testicle biopsy analysed quantitatively (for the presence of mature spermatids) can predict subsequent success or failure with TESE-ICSI. Incomplete testicular failure may involve a sparse multi-focal distribution of spermatogenesis throughout the entire testicle, rather than a regional distribution. Therefore, it is possible that massive testicular sampling from many different regions of the testes may not be necessary for successful TESE-ICSI.      

Adhesion inhibitory activity of β-lactoglobulin isolated from infant formulae

β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis.