"Free" and "exchangeable" or "trapped" and "non-exchangeable" water in cartilage

We repeated some of our own previous experiments, as well as some of Torzilli's recent experiments (11) on which he bases his conclusions relating to a nonexchangeable "trapped water" in cartilage. We are unable to confirm Torzilli's findings. We observed partition coefficients for 3H.HO very close to unity. That both the extrafibrillar and most of the intrafibrillar water is freely exchangeable and behaves as available water towards small solutes has been independently shown (3) for other collagenous tissues. All the different permutations of partition experiments have yielded results that are fully consistent with our original picture of the very major fraction of cartilage water being free.     

Spatiotemporal analysis of auditory "what" and "where" working memory

Goal-directed attention to sound identity (what) and sound location (where) has been associated with increased neural activity in ventral and dorsal brain regions, respectively. In order to ascertain when such segregation occurs, we measured event-related potentials during an n-back (n = 1, 2) working memory task for sound identity or location, where stimuli selected randomly from 3 semantic categories (human, animal, music) were presented at 3 possible virtual locations. Accuracy and reaction times were comparable in both "what" and "where" tasks, albeit worse for the 2-back than for the 1-back condition. The partial least squares analysis of scalp-recorded and source waveform data revealed domain-specific activity beginning at about 200-ms poststimulus onset, which was best expressed as changes in source activity near Heschl's gyrus, and in central medial, occipital medial, right frontal and right parietal cortex. The effect of working memory load emerged at about 400-ms poststimulus and was expressed maximally over frontocentral scalp region and in sources located in the right temporal, frontal and parietal cortices. The results show that for identical sounds, top-down effects on processing "what" and "where" information is observable at about 200 ms after sound onset and involves a widely distributed neural network.     

"Gas off" or "vaporizer off"

Editor—It is a common misconception that turning off thevaporizer while leaving the fresh gas flow (FGF) on, during     

"Empty wall" and "vertical strut" signs of ACL insufficiency

We report our observation on the "empty wall" and "vertical strut" signs of anterior cruciate ligament (ACL) insufficiency. ACL tears most commonly occur in the midsubstance; arthroscopic evaluation of patients with these tears often reveals minimal evidence of previous ACL tissue along the intercondylar wall, thus giving the appearance of an "empty wall." In proximal ACL tears, the long remnant of ACL tissue may adhere to adjacent PCL tissue. Arthroscopically, one may see this vertically oriented strut of tissue, which to the casual arthroscopist may mimic a normal-appearing ACL except for orientation and tension. In addition, the "empty wall" sign will be noted because the lateral intercondylar wall becomes easily visible following ACL injury. In two separate prospective studies of 84 such patients, the combined incidence of the empty wall sign was 82%, and the incidence of the vertical strut sign was 50%. These findings should be sought for meticulously at the time of arthroscopic evaluation. The vertical strut should not be misinterpreted as an aberrantly oriented ACL or partial ACL tear.     

"A" for Agency, "B" for Basal cell, "C" for Corticotulle, "D" for Danger

Without any proof, a governmental agency has decreed that Corticotulle was not enough efficient to be reimbursed by National Health Security. Dealing with treatment of basal cell carcinoma, another governmental agency has published recommendations which even do not follow basic rules of logic. This paper points out that economical and political methods are not scientific or medical ones.     

"Custom-fit" versus "off-the-shelf" ACL functional braces

Many sports medicine practitioners believe "custom-fit" functional braces are superior in performance to "off-the-shelf" braces for anterior cruciate ligament (ACL)-deficient knees. However, this is not well substantiated. This study compares a Donjoy custom-fit ACL brace (CE 2000), Donjoy off-the-shelf brace (Goldpoint), and an athletic taping technique to determine their role in our clinical practice. Five patients (3 men and 2 women) with isolated, unilateral, chronic ACL tears with an average age of 27 years (range: 19-35 years) were used to evaluate these three restraint systems. Anterior tibial laxity, quadriceps and hamstrings strength, endurance, standing long jump, brace migration with exercise, and pattern of muscle response to forced anterior tibial displacement were studied. Each patient was tested without a brace and then in each of the three test conditions (custom brace, off-the-shelf brace, and tape), with the order of testing randomized. The Donjoy custom-fit ACL functional brace did not reduce anterior laxity or improve standing long jump, muscle strength, endurance, or muscle response times significantly more than the off-the-shelf ACL brace. Both braces improved anterior stability over knee taping when the knee muscles were contracted under the low forces used in this study. After 1 hour of exercise, brace migration was significantly greater (P=.03) for the CE-2000 custom brace (18.6 mm) than for the Goldpoint off-the-shelf brace (4.5 mm). There appears to be no advantage to the more expensive custom-fit knee brace over the off-the-shelf brace.