Detecting pre-ovulatory luteinizing hormone surges in urine

The study objectives were to determine (i) if pre-ovulatory luteinizing hormone (LH) surges, undetected in urine by two immunoradiometric assays (IRMA), were detectable by an ultrasensitive immunofluorometric assay (IFMA) and (ii) the influence of creatinine adjustment on the detection and timing of the urinary LH surges. Daily urine specimens were contributed by healthy 25-36 year old volunteers during 14 ovulatory menstrual cycles for an epidemiological study conducted in 1983-1985. Specimens were selected as having been previously assayed by two IRMA without consistently detecting LH surges. These urine specimens were remeasured using an IFMA and adjusted for creatinine concentration. IFMA measurements revealed unambiguous LH surges in all cycles. Adjusting IRMA urinary LH values for creatinine concentrations revealed previously undetected LH surges in four of eight cycles. Creatinine adjustment also altered the timing of IRMA and IFMA LH surges by 1-5 days. These results demonstrate an IFMA that detects pre- ovulatory LH surges in unpreserved, frozen urine from cycles where such surges were previously undetectable. Further, creatinine adjustment can markedly affect detection and timing of the onset and peak of the urinary LH surge. While our analysis suggests that this adjustment improves the validity of the LH measure, this requires further investigation.      

Attitudes about genetic risk of couples undergoing in-vitro fertilization

Many couples undergoing in-vitro fertilization (IVF) are at a higher risk of having a child with a genetic abnormality. In a sample of 55 consecutive couples starting IVF, only 33% had no genetic risk factor. The most common genetic risks were advanced maternal age and possible abnormalities associated with severe male infertility. Despite education on these risks, 71% of couples had no interest in receiving formal genetic counselling. Only 14% of couples at risk would consider using a gamete donor to avoid transmitting a genetic disorder to a child. The triple test to screen for fetal abnormalities was acceptable to 82% of couples, but only 47% planned to have amniocentesis or chorionic villi sampling. Couples were significantly more likely to opt for prenatal testing if they would consider terminating a pregnancy should the fetus have a severe genetic abnormality (P < 0.01). Roman Catholic couples tended to have more conservative attitudes about pregnancy termination. Socio-economic status and whether the infertility factor was male or female were not predictors of a couple's attitudes.      

Non-immune hydrops fetalis and bilateral pulmonary hypoplasia in a newborn infant with extralobar pulmonary sequestration

Extralobar pulmonary sequestration was found in a newborn premature infait that presented with non-immune hydrops fetalis, massive bilateral hydrothorax and polyhydramnios in utero. The baby died of severe respiratory insufficiency 15 h after birth. Postmortem examination revealed distended lymphatic vessels in the sequestered lung tissue probably due to impeded lymph drainage. We suggest that not extralobar pulmonary sequestration itself but a subsequent massive unilateral hydrothorax due to severe obstruction of lymph drainage was the cause of the non-immune hydrops fetalis, pulmonary hypoplasia and polyhydramnios. If these symptoms are diagnosed before delivery, a search for extralobar pulmonary sequestration is indicated.     

Secondary thrombocytosis

To estimate the incidence and causes of secondary thrombocytosis in children, a 12 month study of all patients attending a children's hospital and discovered to have a platelet count over two times the upper normal limit (> 800 x 10(9)/l) was undertaken. Data so obtained were analysed both separately and together with those from two previous studies to gain as broad a perspective as possible. Of 7916 children who had platelet counts during the study period, 36 (0.5%) produced a value > 800 x 10(9)/l; there were 19 boys and 17 girls. There was a preponderance of young infants (median age 13 months). Twenty seven of the 36 had some sort of associated infection, bacterial in 18 and viral in nine. The other nine were either recovering from anti-neoplastic chemotherapy (n = 6), were post-operative (n = 2), or simply iron deficient (n = 1). Combining these patients with those described in previous studies allowed a review of 139 unselected children with very high platelet counts. Fifty three (38%) had infections, 29 (20%) had traumatic or surgical tissue damage, 16 (11%) had malignant disease undergoing chemotherapy or surgery, and 13 (9%) had connective tissue or autoimmune disorders. Secondary thrombocytosis is not rare and is most frequently seen in very young infants after infection. It can arise in a wide variety of other circumstances including rebound from myelosuppression, iron lack, or as part of an acute phase response. It is clinically unimportant in terms of morbidity and requires no treatment other than that for the primary condition.     

Sputum tumour necrosis factor-alpha and leukotriene concentrations in cystic fibrosis

It is postulated that a vigorous host inflammatory response in the cystic fibrosis lung contributes to lung injury. Tumour necrosis factor-alpha (TNF-alpha) may play a part in that process and in the generation of leukotrienes. Therefore, the relationships between sputum TNF-alpha, leukotriene concentration, and lung function abnormalities in 16 children with cystic fibrosis were investigated. Each subject provided sputum samples and performed spirometry. TNF-alpha was measured by enzyme linked immunosorbent assay; individual leukotrienes were separated using high performance liquid chromatography and quantified by radioimmunoassay. The geometric mean concentration of TNF-alpha was 129.7 pg/ml and 95% confidence interval 48.2 to 348.3. Mean (SEM) leukotriene B4 (LTB4) was 97.8 (22.9) pmol/g and total cysteinyl leukotrienes were 60.9 (14.8) pmol/g. Mean (SD) forced expiratory volume in one second (FEV1) of the group was 53 (15)% of predicted and forced vital capacity (FVC) was 65 (14)% of predicted. There was a significant positive correlation between TNF-alpha and both LTB4 and the total cysteinyl leukotriene sputum content. An inverse relationship existed between TNF-alpha and FEV1 and FVC. Moreover, a negative correlation was observed between sputum LTB4 and FEV1 and FVC. These results suggest that TNF-alpha and the leukotrienes may participate in the airways inflammation and airflow obstruction observed in cystic fibrosis subjects and support the hypothesis that TNF-alpha upregulates the 5-lipoxygenase pathway in vivo.