Study of metastable superconducting detector response to irradiation using SQUID-readout

We describe the results of experiments on the³⁵S irradiation of a metastable superconducting detector between 2.0 and 3.4 K using a second-derivative rf SQUID readout operated in an integral mode. The detector consisted of 3×10⁶ tin grains, distributed in diameter from 10–25 micron. Comparison with computer simulation based on a hot border model consistent with the measurement protocols yields reasonable agreement despite the large timing uncertainties associated with the measuring systematics of the SQUID system.     

Cryopreservation of single human spermatozoa

A procedure is described that allows cryopreservation and efficient post-thaw recovery of either a single or a small group of human spermatozoa. This is achieved by injecting them into cell-free human, mouse or hamster zonae pellucidae before the addition of cryoprotectant. The method involves a combination of physical micromanipulation procedures and glycerol-mediated cryoprotection. Zonae were tracked by positioning them in straws between two small air bubbles prior to freezing. Spermatozoa from poor specimens were cryopreserved and their fertilizing ability after thawing was compared with that of fresh spermatozoa from fertile men. Human eggs used for fertilization testing were either 1 day old or in-vitro matured. Only 2% of the frozen zonae were lost and >75% of spermatozoa cryopreserved in this manner were recovered and prepared for intracytoplasmic sperm injection. The feasibility of cryopreserving a single spermatozoon was assessed. Fifteen motile spermatozoa were frozen in 15 zonae, of which 14 were recovered after thawing. Ten were injected into spare eggs, of which eight became fertilized. Spermatozoa recovered mechanically from human zonae fertilized the same proportion of oocytes as fresh fertile control spermatozoa. The recovery and fertilization rates with spermatozoa frozen in animal zonae were 87 and 78% respectively. The fertilization rate was marginally higher (P < 0.05) than that for spermatozoa frozen in human zonae, perhaps because the latter may have acrosome reacted more frequently. The zona pellucida appears to be an ideally suited sterile vehicle for storage of single spermatozoa.     

When is bacterial vaginosis not bacterial vaginosis?--a case of cervical carcinoma presenting as recurrent vaginal anaerobic infection

Vaginal anaerobic infection is the most common cause of vaginal discharge in women. We present a case of recurrent vaginal anaerobic infection and cervical carcinoma and discuss the association of the two conditions. More frequent cytology/colposcopy may be indicated in women who give a history of recurrent or persistent vaginal anaerobic infection.     

Right-ventricular function as assessed by two radionuclide techniques: concise communication

The gated semiautomated first pass and non-gated manual first pass methods of right ventricular ejection fraction calculation were compared. It was found that the gated first pass study was the simplest and fastest to process and was overall judged to give at least as much information as the other technique.     

Physiologic changes associated with ligation of the ductus arteriosus in preterm infants

Cardiorespiratory and transcutaneous oxygen monitors were used on 13 preterm neonates to examine physiologic changes during ductus arteriosus ligation. Transcutaneous oxygen decreased 30 seconds after left lung deflation; all infants required increases in inspired oxygen and ventilation to correct abnormal values after the left lung was compressed. Transcutaneous oxygen decreased 30 seconds after ductus arteriosus ligation (mean delta tcPO2 = -17 mm Hg +/- 11.4) but increased 150 seconds after left lung inflation (mean delta tcPO2 = 46.9 mm Hg +/- 28.8). Arterial blood pressure increased (mean delta systolic BP = 17.9 mm Hg +/- 9.5) and heart rate decreased 10 seconds after ductus arteriosus ligation. In five neonates, gradual closure of the ductus arteriosus over 40 to 75 seconds resulted in a more gradual increase in blood pressure. Intraventricular hemorrhage was confirmed in two patients after surgery. Ligation of the ductus arteriosus results in an abrupt increase in blood pressure, which may be related to the pathogenesis of intraventricular hemorrhage. We suggest that the ductus arteriosus be closed gradually to allow a more gradual increase in blood pressure.     

Prevalence of cardiovascular risk factors including fasting serum triglyceride levels in the Cunderdin health survey of 1971

In a mass health examination conducted in the Shires of Cunderdin and Tammin, 83% of subjects on the electoral rolls attended for screening of cardiovascular risk factors including fasting blood lipid measurements. Fasting serum triglyceride levels are presented. Other factors measured showed quite close similarities to those in the Busselton 1972 Health Survey. On conventional criteria of percentage of desirable weight, fasting serum cholesterol level and fasting serum triglyceride level, a very large proportion of the survey population was found to be eligible for preventive dietary advice--for example, 50% of males and females aged 40 to 59 years. The effective education and after-care of subjects found to be at risk requires further development of resources.