Thiamin status of incarcerated and nonincarcerated adolescent males: dietary intake and thiamin pyrophosphate response

We measured thiamin status in 137 incarcerated and 42 nonincarcerated adolescent males by use of both dietary intake data and a standard biochemical assay, thiamin pyrophosphate (TPP) response. Average thiamin intake of the total group was greater than 120% of the age-specific recommended dietary allowance (RDA). Ninety-two percent of incarcerated subjects and 93% of nonincarcerated subjects were consuming greater than or equal to 70% of RDA. Although average daily thiamin intake of nonincarcerated subjects was significantly higher than that of incarcerated subjects, both groups appeared to be at minimal risk for marginal thiamin status. Comparison of TPP response values indicated that there was no significant difference between groups. However, approximately 24% of the total population appeared to have less than adequate RBC thiamin on the basis of current standards for TPP response. Neither dietary intake nor reported previous alcohol intake was correlated with TPP response. These discrepant findings raise questions about the usefulness of the TPP response as the sole indicator of marginal thiamin status.     

The effects of preservation on microvascular vein grafts in rats

Segments 15 mm in length were excised from the femoral veins of rats and preserved by refrigeration at 4 C in lactated Ringer's solution for periods up to 21 days. The findings show that veins can be preserved for up to seven days and successfully grafted to recipients. Although there was some success in preserving vein segments for more than seven days, a high rate of thrombosis occurred after implantation in the recipients. It is generally accepted that damaged endothelium causes thrombosis. The light and electron microscopic observations in this study, however, suggest that the condition of the endothelium may not be the only important factor in the patency of small vessels. A thickened and prominent elastic lamina may also play a role in keeping the lumen open.     

Effect of bite tray impression technique on relocation accuracy in frameless stereotactic radiotherapy.

A previously developed method for achieving patient relocation in fractionated stereotactic radiotherapy (attachment of an infrared fiducial system to a bite tray) relies on the integrity of a bite tray system that incorporates moulding to the patient's upper dentition. Reproducible and accurate patient positioning requires stability of the bite tray and mould during the full treatment process, both during the time the bite tray is inserted in the patient's mouth, and between separate bite tray insertions. The optimum construction method for a stable reproducible tray has not been sufficiently investigated. We undertook a study to identify factors which might influence the integrity of the hard palate bite tray system. Reprosil Fast Set Putty was used to construct 3 impression conditions; teeth only; teeth and alveolar sulcus; and teeth, alveolar sulcus, and the hard palate. Reproducibility was assessed by volunteers inserting the impressions multiple times and recording the locations of 8 standard reference points. Our results showed the optimal impression technique (i.e., the one that led to the smallest ranges in positional and rotational errors) was that which incorporated the teeth, alveolar sulcus, and hard palate.     

Third level hemodynamics: guiding clinical decisions.

Hemodynamic monitoring is one of the most frequently used technologies in critical care nursing. But how often do critical care practitioners consider the underlying reason for monitoring these variables? What really is the oxygen balance in the cell? How does oxygen supply and demand figure into the hemodynamic equation? This article demonstrates how the imbalance of oxygen supply and demand at the cellular level is important to understanding the patient's hemodynamic status. It is followed by a continuing education packet you can use to teach the cellular principles of hemodynamics.     

Churchill's Pocketbook of Intensive Care, 2nd Edn. S. M. Whiteley, A. Bodenham, M. C. Bellamy (editors). Published by Churchill Livingstone, Edinburgh. Pp. 406; indexed; illustrated. Price {pound}19.99. ISBN 0-4430-7258-2.

This superb little book offers a wealth of information, practicaladvice and food for thought for all trainees in critical care.It will be useful for students and doctors preparing for theirfirst