Effect of particle size on the surface properties and morphology of ground flax.

Flax fibers were ground with a ball-mill and four fractions with different size ranges were collected by sieving. These were tested for water sorption, degree of polymerization (DP), copper number, hydroxyl number and analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and inverse gas chromatography (IGC). Significant differences were found between the properties of the flax fiber and those of the ground versions, including fragmentation of fibers, increase of water sorption, copper number, hydroxyl number and surface O/C ratio, and decrease of DP, crystallite size and dispersive component of surface energy (γs(d)). Some parameters depended on the particle size: O/C ratio and hydroxyl number had local maxima at 315-630 µm, while γs(d) increased steadily with the decrease of particle size. These relationships were explained by fiber disintegration, destruction of waxy surface layer, exposure of cellulosic components, increase of surface area and crystalline imperfections.

Effects of yessotoxin (YTX) on the skeletal muscle: an update.

Yessotoxins (YTXs) are algal toxins originally included in the diarrheic toxins. After oral intake, YTXs induce only ultra-structural changes (packages of swollen mitochondria) in cardiac cells. The aim of this study was to investigate the possible effects of YTX on the other contractile striated tissue, the skeletal muscle, in vitro and in vivo. In vitro, in skeletal mouse myotubes, YTX (0.01-1.0 microM) influenced cell excitability in a concentration- and time-dependent way. In the in vivo study, transmission electron microscopy analysis did not reveal any ultrastructural alteration of skeletal muscle after acute (1 mg kg(-1)) or repeated (1 and 2mg kg(-1) day(-1), for 7 days) oral administration of YTX to mice. The observation that effects were detected in vitro but not in vivo supports the hypothesis of a low YTX bioavailability to skeletal muscle after oral intake. Therefore, the results seem to exclude a toxic effect in skeletal muscle when YTX is consumed as a food contaminant.

Spinal block levels and cardiovascular changes during post-Cesarean transport.

PURPOSE: Transport after surgery under spinal anesthesia is associated with cardiovascular changes. The extensively vasodilated patient may be unable to compensate for postural blood flow redistribution. This observational study investigated pre- and post-surgery sensory levels as well as hemodynamic changes during the postoperative transfer period. METHODS: One hundred ninety nine women, ASA 1 and 2, undergoing Cesarean section under spinal anesthesia were studied at the end of surgery. Hyperbaric bupivacaine 12-15 mg and morphine 0.25 mg were the agents used. Patients in group A (n = 111) were transferred to the Recovery Room on a stretcher with the upper body flexed 30 degrees head up: patients in group B (n = 88) remained supine during transport. RESULTS: At the end of Cesarean section 95% of patients had upper sensory levels of T4 and higher. In 17.5% the block ascended 2-7 dermatomes compared with the pre-operative level. The incidence of hypotension on arrival in Recovery Room was similar in both groups (group A 10% and group B 9%). CONCLUSION: These results draw attention to the persistence of extensive sympathetic block at the end of Cesarean section. Transport to the Recovery Room was associated with the development of considerable hypotension in 10% of patients and this was unaffected by position. We recommend recording the level of sensory block at the end of surgery and increased monitoring during transport to the Recovery Room.

The effect of azathioprine, cyclosporine A and insulin on the in vitro lymphocyte-mediated cytotoxicity in type I diabetic patients.

Previously both specific and nonspecific immune reactions have been reported in patients with type I diabetes mellitus. In this study the effect of various immunosuppressive drugs and insulin was studied on in vitro lymphocyte-mediated cytotoxicity in 20 type I diabetic patients. Twenty sex- and age-matched healthy subjects served as controls. Human pancreas-extract (300 micrograms/ml protein)-coated, 51-Chromium labeled chicken erythrocytes were used as target cells and separated T-lymphocytes as effector cells with and without azathioprine 50 micrograms/50 microliters (Wellcome), Cyclosporine A 5 ng/50 microliters (Sandoz) and MC Actrapid insulin 0.1 IU/50 microliters (Novo). The degree of cytotoxicity was expressed with cytotoxic capacity: the number of maximal killed target cells. Simultaneously islet cell antibodies (ICA) in sera and the number of activated T-lymphocytes were assessed. Significant lymphocyte-mediated cytotoxicity was observed in the majority of type I diabetic patients (18/20), while no cytotoxicity was found in the control cases. The cytotoxicity decreased in all 16 patients using azathioprine or insulin, independently of ICA and HLA-DR positivity. The number of killed target cells was lowered considerably by Cyclosporine A in all 18 patients having cytotoxicity against pancreas-extract. Our observations reveal that Cyclosporine A proved to be the most effective immunosuppressive agent in vitro. It decreases not only the leucocyte migration inhibition as previously observed, but also the lymphocyte-mediated cytotoxicity, which represents the late stage of cellular immune reactions against pancreatic tissue.