Calcareous deposits formed on IUDs in human exposures

Characteristics of the calcareous deposits on several hundred IUDs of various designs and materials following in vivo exposures were examined, and an in vitro method of study was devised. There were 650 copper-wound IUDs and 18 plastic IUDs. The copper-wound IUDs had been in the uteri for 6-27 months; the plastic IUDs for 3 months to over 8 years. Microscopic examinations, X-ray diffraction, weight changes, and chemical analyses were used. X-ray diffraction showed that calcite (CaCO3) was the major crystalline constituent of the calcareous deposits. A large fraction of the deposited material was organic. Surfaces in contact with the uterine wall were essentially free of depos its. Microscopic inspection of copper-wound IUDs revealed the amount of deposit. Length of exposure increased the amount of deposit, but there were marked variations in amount. Accumulation of deposits was mostly at the fundal end. More marked local erosion of copper was noted where there was little or no carbonate deposit. Deposits occurred in patches on Lippes loops and Margulies spirals. The in vitro carbonate deposits did not reproduce the rates or morphology of the in vivo deposits. Variations in uterine carbonate formation are attributed to differences in uterine chemistry of individuals.     

Effect of umbilical artery catheters on blood flow and oxygen supply to extremities

The effect of catheter placement in the abdominal aorta on the blood flow and oxygenation of lower extremities was evaluated in 30 New Zealand rabbits, weighing 0.55-3.5 kg, by inserting 3.5 and 5.0 French polyvinyl chloride catheters, of the type commonly used for umbilical artery catheterization, through the femoral artery, advancing 15-20 cm, and leaving in place for 10-30 min. Arterial blood pressure (BP), common iliac artery blood flow (BF), gracilis muscle tissue oxygen availability (O2a), and subcutaneous temperature (T) in the foot were continuously monitored before and during catheter placement and after withdrawal. There were no changes in the physiologic variables measured in the contralateral leg when the catheter remained below the aortic bifurcation; however, when the catheter was advanced 15-20 cm into the abdominal aorta, a decrease in lower extremity BF, O2a, and T occurred. Because the length of catheter insertion was maintained constant in each animal, the decreases in BF, O2a, and T are related to the relative dimensions of the vessel and the catheter. The ratio of catheter to vessel diamter, in addition to the site of catheter placement, should be considered during the clinical application of arterial catheters. Reduction in blood flow could be detected by continuous differential monitoring of core and extremity temperature or extremity muscle oxygen availability.     

Defining the precapillary sphincter

Influence of denervation on phospholipid metabolism in the vas deferens and effect of phospholipase C treatment on sensitivity of the vas deferens for noradrenaline were studied. The incorporation of 32P-orthophosphate into phosphatidylethanolamine and phosphatidylcholine was markedly increased by denervation. Incorporation of 32P-orthophosphate into proteolipid was accelerated more than that of 3H-leucine. Sensitivity of the denervated vas deferens for noradrenaline was strongly reduced by phospholipase C treatment. These data suggest that the supersensitivity of the denervated vas deferens for noradrenaline was mainly due to the increase in phospholipids.     

Response properties of single units in an association area of the kitten neocortex

Two percept-genetic methods, the Meta-Contrast Technique (MCT) and the Serial Afterimage Test (AI), were used to study adaptive aspects of perception in a group of 37 subjects suffering from manifest anxiety. The perceptual processes laid bare by these methods reflected not only anxiety but also defensive formations. MCT and AI correlated with each other in these respects and, when combined, correlated with rated symptoms. In accordance with the theory behind percept-genetic methods, anxiety signs appearing late in the test serials were more likely to correspond to manifest symptoms than signs which appeared early. The AI test scores seemed to reflect a difference between anxiety experienced as an inherent quality of life and anxiety as a foreign force struggling for dominance.     

Incidence of trichothecenes and zearalenone in poultry feed mixtures from Slovakia

A total of 50 samples of poultry feed mixtures of Slovakian origin were analyzed for eight toxicologically significant Fusarium mycotoxins, namely zearalenone (ZON), A-trichothecenes: diacetoxyscirpenol (DAS), T-2 toxin (T-2) and HT-2 toxin (HT-2) and B-trichothecenes: deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3-ADON), 15-acetyl-deoxynivalenol (15-ADON) and nivalenol (NIV). The A-trichothecenes and the B-trichothecenes were detected by means of high pressure liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) and gas chromatography electron capture detection (GC-ECD), respectively. Reversed phase-high performance liquid chromatography with a fluorescence detector (RP-HPLC-FLD) was used for ZON detection. The most frequent mycotoxin detected was T-2, which was found in 45 samples (90%) in relatively low concentrations ranging from 1 to 130 microg kg(-1) (average 13 microg kg(-1)), followed by ZON that was found in 44 samples (88%) in concentrations ranging from 3 to 86 microg kg(-1) (average 21 microg kg(-1)). HT-2 and DON were detected in 38 (76%) and 28 (56%) samples, respectively, in concentrations of 2 to 173 (average 18 microg kg(-1)) for HT-2 and 64 to 1230 microg kg(-1) sample (average 303 microg kg(-1)) for DON. The acetyl-derivatives of DON were in just four samples, while NIV was not detected in any of the samples investigated. In as many as 22 samples (44%), a combination of four simultaneously co-occurring mycotoxins, i.e. T-2, HT-2, ZON and DON, was revealed. Despite the limited number of samples investigated during this study poultry feed mixtures may represent a risk from a toxicological point of view and should be regarded as a potential source of the Fusarium mycotoxins in Central Europe. This is the first reported study dealing with zearalenone and trichothecene contamination of poultry mixed feeds from Slovakia.     

The Effect of Hybrid Carrageenan on the Thermo-rheological Properties of Gluten-Free Flour Doughs Using a Modified Kneading Protocol

Thermo-rheological behaviour of chestnut flour doughs supplemented with kappa/iota-hybrid carrageenan (HC) (up to 2.0%, flour basis (f.b.)) and sodium chloride (1.8%, f.b.) was determined at both target (C1) and final (C5) mixing peaks. For this purpose, small amplitude oscillatory shear (0.01 to 100 Hz), creep–recovery (loading of 50 Pa for 60 s, 30 °C), temperature sweeps (from 30 up to 180 °C) and heating/cooling cycles (between 30 and 60 °C) were conducted on a controlled stress rheometer. Previously, the thermal-mixing behaviour at proposed mixing temperature (50 °C) was conducted on Mixolab® apparatus. Results showed that the dough stability (from 2.2 to 5.8 min) in mixing stage and starch heat resistance to dough processing were significantly improved at proposed mixing temperature, even in the absence of HC. No statistical differences in rheological properties were observed for doughs evaluated in C1; however, those analysed in C5 were significantly modified in the presence of HC, mainly in terms of viscous behaviour (from 52.1 × 10⁶ to 39.1 × 10⁶ Pa s). Creep–recovery data sets, successfully fitted using Burgers model, revealed that the elasticity (J _r/J _max from 73.3 to 87.6%) of doughs analysed in C5 improved with HC addition. Thermal tests showed that the starch transitions were significantly promoted and stabilized with HC addition.     

Influence of small dozes ultra-violet radiation on motion of dislocation in alkali-halide crystals

The purpose of this work was research into influence of ultra-violet radiation on size of run of regional and screw dislocations in beams of dislocation sockets, formed at indentation surface of alkali-halide crystals. In experiments it was used crystals NaCl, with the quantitative maintenance of impurity 10-2 -10-3weight,, the wave length of UV-radiation λ=250 nanometers, the sizes of samples 10mm× 20mm× 2mm,temperature of samples was constant T=290 K.It is established that indentation and the simultaneous irradiation of samples a ultraviolet is increases size of run of head dispositions in dislocation sockets..It is marked, that influence UV-radiation nonequivalence for various times of an exposition. At small times (till 5 minutes) the size of run grows. The length of beams increases on ～ 50 ,. At the further increase in time of influence of a ultraviolet the length of beams is reduced till the sizes corresponding stressing without an irradiation (Figs. 1, 2, 3). The effect is observed on dislocation beams of regional and screw orientations and most expressed at small loadings (in our experiments-10 grams) (Fig. 3).Observable effects are explained from positions dislocation-exciton interactions. At UV-radiation exciton cooperates with the charged step on a disposition, causing movement of a step along a disposition on one internuclear distance. Due to this interaction overcoming by a disposition of a grid of stoppers is facilitated.Big times of endurance cause a relaxation of pressure directly in a print that provides convertible movement of dispositions in area of a print and as consequence, reduction of length of beams of dislocation sockets.