Bifunctional oligonucleotide probes synthesized using a novel CPG support are able to detect single base pair mutations

A novel multifunctional controlled pore glass, MF-CPG (Fig. 1), has been synthesized and used to incorporate 3' terminal primary aliphatic amines into synthetic oligonucleotides. MF-CPG consists of a unique succinic acid linking arm which possesses both a masked primary amine for label attachment and a dimethoxytrityl protected hydroxyl for nucleotide chain elongation. Using MF-CPG, we have devised a simple and convenient technique to attach non-radioactive labels to the 3' terminus of oligonucleotides. Bifunctional probes can then be constructed by 32P labeling the 5' terminus with T4 kinase and gamma 32P-ATP. Using such bifunctional oligonucleotide probes in conjunction with polymerase chain reaction (PCR) amplification, we were able to detect single base substitutions in a target segment of the human H-ras protooncogene employing either functionality. Our technique thus expands the potential applications for oligonucleotides as hybridization probes.

Comparison of oral transmucosal fentanyl citrate and an oral solution of meperidine, diazepam, and atropine for premedication in children

The safety and efficacy of premedication with oral transmucosal fentanyl citrate (OTFC) was compared with that of an orally administered solution of meperidine, diazepam, and atropine and no premedication in 59 children about to undergo elective operations. The patients were randomly assigned to receive no premedication (n = 19); 0.25 ml/kg of the oral solution (containing meperidine, 1.5 mg/kg, diazepam, 0.2 mg/kg, and atropine, 0.02 mg/kg, n = 20); or OTFC (15-20 micrograms/kg, n = 20). Children had activity (sedation) and anxiety scores, vital signs (including systolic and diastolic arterial blood pressures and heart and respiratory rates) and pulse oximetry determined oxygen saturation measured before and at 10-min intervals after premedication until they were taken to the operating room. Quality of induction and recovery was evaluated using scoring schedules; recovery times were measured and side effects noted. OTFC was readily accepted and provided significant reductions in preoperative activity (sedation) and anxiety starting after 30 min. After OTFC, sedation and anxiolysis were significantly greater than in children having no premedication but similar to children having the oral solution for premedication. Vital signs and oxygen saturations remained unchanged preoperatively in all groups. Induction and recovery evaluations and recovery times were similar in the three groups, although children having OTFC had the lowest requirements for narcotics in the recovery room. OTFC caused an 80% incidence of mild preoperative facial pruritus and a higher overall incidence of postoperative vomiting (37%) than premedication with the oral solution (5%) or no premedication (18%).(ABSTRACT TRUNCATED AT 250 WORDS)

Optometry in Britain

The author spent seven months in Britain on sabbatical leave from the Illinois College of Optometry. One purpose of the time away was to learn about the optometric profession and education in the United Kingdom. The result is a view of the profession based on visits to optometric institutions and private practices and discussion with medical and optometric colleagues.

Fetal growth and placental diffusing capacity in guinea pigs following long-term maternal exercise

To determine the critical level of maternal exercise which produces effects on fetal weight and placental diffusing capacity, we measured the relationship between increasing levels of exercise and its effect on the fetus. Hartley guinea pigs with dated pregnancies were exercised on a treadmill (9.7 m/min at a 6.5% gradient) at one of five exercise levels (0, 15, 30, 45, and 60 min/day). We measured placental diffusing capacity for carbon monoxide (DPCO) fetal body and organ weights, placental weight, and maternal body and heart weights near term (63-64 days). Fetal body weight, kidney weight, and placental weight decreased as a function of increasing exercise level, decreasing 13, 13, and 21% respectively at 60 min/day exercise. DPCO1 decreased from a control value of 2.92 +/- 0.23 to 2.33 +/- 0.10 ml. min-1 torr-1 kg fetal wt in the 15 min/day exercise group, 2.17 +/- 0.08 in the 30 min/day group 2.16 +/- 0.11 in the 45 min/day group, and 2.65 +/- 0.31 in the 60 min/day exercise group. The decrease in placental weight along with the decrease in DPCO per kg of fetal weight suggests that with progressive maternal exercise the fetus is compromised by a smaller than normal placenta with less diffusing capacity.

Distribution of maternal and fetal blood flow within cotyledons of the sheep placenta

These studies explore the distribution of blood flow among small samples of placental tissue. Labeled microspheres (14 +/- 1 micrometers, SD) were injected into the left ventricle of six unanesthetized ewes and into the jugular vein of the fetuses in utero. A total of 3,576 samples weighing 31 +/- 11 (SD) mg were taken from 17 cotyledons and counted for flow labels. Maternal and fetal blood flow within the cotyledons were both normally distributed with standard deviations of 44%. The maternal-fetal blood flow ratio was less than 0.5 in 9% of the cotyledon, between 0.5 and 1.5 in 70%, and greater than 1.5 in 21%. Errors caused by the method were estimated to contribute less than 10% of the flow variances. Maternal and fetal blood flows were significantly correlated (r = 0.57, P less than 0.001), and both exhibited spatial organization. Calculations based on mathematical models suggested that the observed distribution of the ratio of maternal to fetal blood flow may explain about 50% of the uterine-umbilical venous oxygen tension difference. It was concluded that the samples studied were small in comparison with the dimensions of placental oxygen exchange but may have been similar in size to the dimensions of blood flow control.