Efficacy of "high-intensity" blue-light and "standard" daylight phototherapy for non-haemolytic hyperbilirubinaemia

We report our clinical experience with phototherapy in 3802 infants; 3629 were exposed to "standard" daylight phototherapy and 173 to "high-intensity" blue-light phototherapy. High-intensity blue-light phototherapy was twice as effective as standard daylight phototherapy in decreasing bilirubin concentrations. No failures occurred with high-intensity phototherapy compared with an overall failure rate of 1.84/1000 with daylight lamps; these cases were transferred to high-intensity phototherapy with prompt response. Rebound after cessation of phototherapy was greater in those exposed to high-intensity blue light with a significantly greater number requiring a second exposure. However, the incidence was still low. No third exposure was required in any infant. Nursing of infants under high-intensity blue light was more difficult and inconvenient as was clinical monitoring. The light also caused more stress on the nursing and medical personnel. However, the infants tolerated both types of phototherapy equally well. High-intensity blue-light phototherapy would seem to be the treatment of choice for infants with rapidly increasing or very high bilirubin levels, as well as in those not responding adequately to daylight phototherapy.     

Use of preformed hydroxylapatite blocks for grafting in genioplasty procedures

Dense hydroxylapatite is a synthetic, biocompatible, immunologically inert material that can establish a chemical union with bone when placed in intimate contact in histologic studies. The following is a preliminary report of the use of preformed dense, non-resorbable hydroxylapatite blocks as a grafting material for use in advancement and vertical lengthening of the bony chin associated with orthognathic surgical procedures. In rare instances where an autogenous bone graft would be required for vertical lengthening without any advancement of bony pogonion, the need is obviated by utilization of the hydroxylapatite solid block.     

Drug design: nitrosoureas

Attempts to develop more effective and less toxic antineoplastic nitrosoureas are summarized. Previous research resulted in the synthesis and extensive preclinical testing of new, short-chain, water-soluble, but lipophilic compounds--1-(2-chloroethyl)-1-nitroso-3-(2-hydroxyethyl)urea (HECNU) and 1-(2-chloroethyl)-1-nitroso-3-(methylene carboxamido)urea. Molecular mechanisms of reactions with biomolecules are discussed with regard to DNA alkylation and cross-linking, carbamoylation of glutathione and glutathione reductase inhibition. Results of a clinical phase-II study show that HECNU, as predicted from preclinical tests, exhibits outstanding activity in brain tumours. Future development concentrates on the use of carrier molecules for nitrosoureas. Results of an extensive structure-activity study with oestradiol-linked analogues show that an oestradiol-17 ester derivative is much more active than other analogues.     

New vectors of Rift Valley fever in West Africa.

After an outbreak of Rift Valley fever in Southern Mauritania in 1987, entomologic studies were conducted in a bordering region in Sénégal from 1991 to 1996 to identify the sylvatic vectors of Rift Valley fever virus. The virus was isolated from the floodwater mosquitoes Aedes vexans and Ae. ochraceus. In 1974 and 1983, the virus had been isolated from Ae. dalzieli. Although these vectors differ from the main vectors in East and South Africa, they use the same type of breeding sites and also feed on cattle and sheep. Although enzootic vectors have now been identified in West Africa, the factors causing outbreaks remain unclear.     

Ankle: surface coil MR imaging at 1.5 T

High-field surface coil magnetic resonance (MR) images were obtained of 12 ankles: two from healthy volunteers, seven from patients, and three from fresh cadavers. The cadaver ankles were sectioned in the coronal, sagittal, and axial planes for direct comparison with the MR images. Plain film confirmation of pathologic conditions was obtained in all patients, and five underwent arthroscopy or surgery, or both. MR imaging provided excellent delineation of ligaments and cartilaginous structures in all cases.