XPS analysis of poly[(3-hydroxybutyric acid)-co-(3-hydroxyvaleric acid)] film surfaces exposed to an allylamine low-pressure plasma

Homogeneous and stable layers were deposited through allylamine plasma polymerization (75 W, 100 Pa, 15 min) onto poly[(3-hydroxybutyric acid)-co-(3-hydroxyvaleric acid)] (91 : 9 wt.-%) (P(HB-co-9%HV)) film surfaces, XPS analysis using take-off angles of 20° and 70° and performed 10 days and 20 days after plasma treatment gives information on the composition (in atom%) of the modified surface: C, 62.74; N, 19.60; O, 17.65. The unexpected oxygen percentage is weaker if argon plasma pretreatment (25 W, 40 Pa, 5 min) is applied. Then, a succinct mechanism is proposed. The study of changes in element ratios and binding energy values shows that the majority of incorporated functional groups seem to be amide and imine groups.     

Peripheral gangrene associated with Kawasaki disease.

Three American infants with Kawasaki disease (KD) complicated by peripheral extremity gangrene are reported. Eight such patients (only 1 from Japan) have been reported previously. These 11 patients, infants less than 7 months old at onset of KD, are predominantly non-Asian. At least nine had associated giant coronary aneurysms, and eight had associated peripheral arterial aneurysms. In eight infants the diagnosis of KD was not established and therapy was not instituted until greater than or equal to 14 days after onset. Peripheral ischemia initially was noted 15-31 days after onset. Although the pathogenesis of this complication is not well understood, it likely includes some combination of local peripheral arteritis, arteriospasm, thrombosis peripherally and/or more proximally (e.g., in an axillary artery aneurysm), and cardiogenic shock. Treatment may include use of antiinflammatory agents such as salicylates and intravenous gamma globulin, vasodilative agents and/or methods, and thrombolytic and/or anticoagulant agents in an attempt to prevent the potentially devastating consequences of progressive gangrene.     

Pituitary fossa: chemical shift effect in MR imaging

The effect of chemical shift on magnetic resonance (MR) imaging of the pituitary fossa was studied. Healthy volunteers underwent conventional MR imaging of the pituitary fossa and then imaging with the frequency-encoding gradient reversed or with the phase- and frequency-encoding gradients interchanged. Comparison of the image pairs in each subject showed that the thin, black stripe evident at the water-fat interface within the pituitary fossa was altered when the gradients were changed. Therefore, the low-intensity signal within the pituitary fossa is a chemical shift misregistration effect.     

Anulus fibrosus in bulging intervertebral disks

In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks.     

Organisation fonctionnelle de l'articulation fémorotibiale

The knee joint is composed of two articular systems: the femorotibial and femoropatellar joints. The femorotibial joint appears quite instable, with its two convexe femoral condyles on the planar tibial surface. Actually, a muscular and tendinous organization ensures stability during motion. The muscular extensor system, with quadriceps patella and patellar tendon, controls the forward sliding of the femoral condyles and provides the knee stability in the sagittal plane. The posterior internal/external capsular and muscular reinforcements, also called posterolateral/posteromedial corner, ensures stability during rotation in the frontal and horizontal planes. Nonetheless, it is necessary to add to this muscular organization, a powerful informative system where the cruciate ligaments of the knee assume the major role. Those ligaments still remain in tension and inform the nervous system in any motion of the knee. This functional organization allows both large flexion-extension and stability. This article shows as an example the functional organization of the femorotibial joint.     

Metabolic consequences of physical inactivity.

Physical inactivity is associated with alteration of normal physiologic processes leading to muscle atrophy, reduced exercise capacity, insulin resistance, and altered energy balance. Bed rest studies in human beings using stable isotopes of amino acids indicate that muscle unloading decreases the turnover rates of muscle and whole-body proteins, with a prevailing inhibition of protein synthesis. In the fasting state, muscle and whole-body nitrogen loss was not accelerated during bed rest. In experimental postprandial states, the amino acid-mediated stimulation of protein synthesis was impaired, whereas the ability of combined insulin and glucose infusion to decrease whole-body proteolysis was not affected by muscle inactivity. Thus, an impaired ability of protein/amino acid feeding to stimulate body protein synthesis is the major catabolic mechanism for the effect of bed rest on protein metabolism. This suggests that a protein intake level greater than normal could be required to achieve the same postprandial anabolic effect during muscle inactivity. Metabolic adaptation to muscle inactivity also involves development of resistance to the glucoregulatory action of insulin, decreased energy requirements, and increased insulin and leptin secretion. These alterations may lead to the development of the metabolic syndrome that is defined as the association of hyperinsulinemia, dyslipidemia, hypertension, hyperglycemia, and abdominal obesity. This cluster of metabolic abnormalities is a risk factor for coronary artery disease and stroke. Evidence indicates that exercise training programs may counteract all of these abnormalities both in healthy sedentary subjects and in patients affected by a variety of chronic disease states.