Neurophysiologic signal recording. New technical and general practice aspects of EEG recording electrodes

BACKGROUND: The most serious complication of diabetes is the progressive development of vascular changes in which impaired hemocoagulation and fibrinolysis participate. The latter were investigated in diabetes type 1 and 2, but les is known about them in gestational diabetes (GDM). The objective of the submitted work was to assess wither these disorders occur also during GDM and to compare the assessed changes of haemostasis and fibrinolysis with findings in a) non-pregnant healthy controls (n = 58), b) healthy pregnant women (n = 41) and c) groups of pregnant women with impaired haemostasis during gestation/gestational hemorrhage (n = 15), preeclampsia (n = 22), varicosities (n = 15) and dead foetus syndrome (n = 16), but normal carbohydrate metabolism. The changes in GDM were moreover compared with changes found in diabetes type 1 and 2. METHODS AND RESULTS: In pregnant women with GDM (n = 29) which was diagnosed according to WHO criteria the following parameters were examined: number of thrombocytes, APTT, fibrinogen-Fbg (according to Clauss), euglobulin fibrinolysis-ECLT, t-PA concentration, PAI-I (Coaliza, Kabi) and by microturbidimetry the concentration of plasma proteins/orosomucoid (ORM), alpha-1-antitrypsin (A1AT), prealbumin (PREA), transferrin (TRF) and alpha-2-macroglobulin (A2M). In patients with GDM a high Fbg level was found (4.51 +/- 0.98 g/l, p<0.01) not only as compared with Fbg in non-pregnant women (2.42 +/- 0.40 g/l), Fbg in healthy pregnant women (3.63 +/- 0.70 g/l) but also Fg in other patient groups with a pathological pregnancy. In pregnant women with GDM a reduced fibrinolytic activity - ECLT (464 +/- 98 min., p<0.01) was observed as compared with the finding in non-pregnant women (273 +/- 98 min.) but also in healthy pregnant women (303 +/- 106 min.). Another important deviation as compared with findings in healthy pregnant women in GDM is the reduced value of two proteinase inhibitors: A2M (2.04 +/- 0.59 g/l vs. 2.89 +/- 0.90 g/l, p < 0.01) and A1AT (2.98 +/- 0.80 g/l vs. 3.96 +/- 0.85 g/l, p < 0.01). The rise of t-PA (Ag), PAI-1 (Ag), fibrinogen and reduction of fibrinolytic activity (longer ECLT) made the changes the haemostasis and fibrinolysis in GDM closer to findings in DM type 2 than type 1. CONCLUSIONS: In GDM a higher thrombophilia was found (higher Fbg, longer ECLT) than in other groups of pregnant women. Another pathological finding is the reduced A2M level (proteinase inhibitor but also of PDGF and interleukins) and A1AT (inhibitor of leucocytic proteinases). The authors assume that these deviations favour the development of possible vascular changes in GDM and possibly also diabetic foetopathy (reduced A2M).     

Detection of doubly stained fluorescent specimens using confocal microscopy

Studies of doubly stained specimens were performed with a confocal scanning microscope. The instrument used provides the possibility of making separate detections of the fluorescent dyes. The optimal choice of excitation wavelengths and optical filters are discussed. The fluorphores that were used are Lucifer Yellow, Texas Red, fluorescein isothiocyanate and tetramethylrhodamine isothiocyanate.     

High-frequency electrooptic Fabry-Perot modulators

Electrooptic modulators built from GaAs/Al/sub x/Ga/sub 1-x/As Fabry-Perot cavities operating up to 6.5 GHz are reported. The measured frequency response agrees well with the one predicted using an equivalent circuit model derived from high-speed electrical measurements. The parasitic capacitances have been reduced to approximately 30 fF by fabricating the devices on semi-insulating GaAs substrates and integrating them with on-wafer bound pads which have dimensions compatible with microwave coplanar probes.<>     

Grafting polythiophene on polyethylene surfaces

Polythiophene (PT) was grafted on PE film using three reaction steps. First, PE films were brominated in the gas phase, yielding PE–Br; second, a substitution reaction of PE–Br with 2‐thiophene thiolate anion gave the thiophene‐functionalized PE; finally PT was grafted on the PE surface using chemical oxidative polymerization to give PE–PT. The polymerization was carried out in a suspension solution of anhydrous FeCl₃ in CHCl₃, yielding a reddish PE–PT film after dedoping with ethanol. ATR‐FTIR shows that the PT was grafted on PE in the 2,5‐position. SEM imaging revealed islands of PT on the PE film. AFM analysis found the thickness of islands to be in the range of 120–145 nm. The conductivity of these thin films was in the range of 10^?6 S cm^?1, a significant increase from the value of ～10^?14 S cm^?1 measured for PE film. © 2003 Society of Chemical Industry     

Gravity or suction drainage in thyroid surgery? Control of efficacy with ultrasound determination of residual hematoma

In a prospective randomized trial, the common high-vacuum drainage system according to Redon was compared with the nonsuction system according to Robinson in 80 patients undergoing elective thyroid surgery between January 1995 and August 1995. Forty patients were provided with nonsuction, passive drains, and another 40 patients were allocated to a control group with the high-vacuum system. Twenty-four h postoperatively, the wound area was analyzed by sonography after drainage removal. The dimension of the remaining hematoma was determined by scanning the operation field in six to seven layers (thickness per layer T = 1 cm). The area (A) of the hematoma was measured per layer, and thus the volume was determined by the formula: V = T x (A1 + A2.. + A(n)). Simultaneously, the quantity of discharge was determined. Patients receiving nonsuction drainage had significantly lower median drainage volume (34 ml; range: 0-175 ml vs-115 ml; range: 40-346 ml; P < 0.01) and a remaining hematoma, measured sonographically, of similar volume to that of the patients receiving high-vacuum treatment (4.4 ml; range: 0-21.7 ml vs 5.3 ml; range: 0.6-24.9 ml; not significant). No complications were observed. An advantage to using the nonsuction device is seen with respect to similar resting wound hematoma, lower fluid evacuation, and painless drain removal. This study supports prophylacity routine nonsuction wound drainage after elective thyroid surgery.     

Cardiovascular effects of nylidrin (Dilatol) in pregnancy

8 normotensive late pregnant women were examined before, during and after the intravenous administration of nylidrin (Dilatol) with the method of quantitative sphygmometry, the bloodless graphic registration of the arterial blood pressure and the direct electronic timing of pulse wave velocity. Systolic blood pressure remains unchanged; mean and diastolic blood pressure and total peripheral resistance decrease. Simultaneously heart rate, stroke volume and above all cardiac output increase. The hemodynamic mode of action of nylidrin is a favourable one in regard to the perfusion of tissues in pregnancy, because the fall of total peripheral resistance is much more pronunciated than the decrease of blood pressure. Therefore there are no objections to a tocolytic treatment with nylidrin in normotensive pregnant women on the part of cardiovascular system.     

Use of ozone in a lettuce‐washing process: an industrial trial

Bacteria such as Escherichia coli and Salmonella spp. may cause serious problems for the quality maintenance of pre‐packaged lettuces. The aim of this study was to evaluate the bactericidal effect of ozonated water in the washing of iceberg lettuce. For this purpose an ozone generator was integrated into a commercial lettuce‐washing facility. Lettuce samples were removed from this process and analysed for mesophilic total viable count (TVC), E. coli, Salmonella spp., vitamin C and sugar content. The analyses were carried out either directly after washing or at the end of best‐before date (BBD), in which lettuces were stored at 4 °C for 6 days. Water samples were analysed for total organic carbon (TOC) content and pH. Through the addition of ozone to the wash water the quality of lettuce during storage time was unaffected while there was only a limited observed decrease in populations of microorganisms. Copyright © 2007 Society of Chemical Industry     

Disruption of cholesterol 7alpha-hydroxylase gene in mice. I. Postnatal lethality reversed by bile acid and vitamin supplementation

Mice deficient in cholesterol 7alpha-hydroxylase, the rate-limiting enzyme of bile acid biosynthesis, were constructed by targeted disruption of the Cyp7 gene. The introduced mutation removed exons 3-5 of the gene and gave rise to a null allele that encoded no immunoreactive or enzymatically active protein. Heterozygous carriers of the disrupted gene (Cyp7+/-) were phenotypically normal. Homozygous animals (Cyp7-/-) appeared normal at birth, but died within the first 18 days of life. Approximately 40% of the animals died between postnatal days 1 and 4 and 45% between days 11 and 18. The addition of vitamins to the water of nursing mothers prevented deaths in the early period, whereas the addition of cholic acid to chow prevented deaths in the later period. Newborn Cyp7-/- mice whose mothers were maintained on unsupplemented chow failed to gain weight at a normal rate and developed oily coats, hyperkeratosis, and apparent vision defects. These symptoms waned at 3 weeks of life, and their disappearance was accompanied by a marked increase in survival. In the accompanying study, the induction of an alternate pathway of bile acid biosynthesis is shown to underlie this unusual time course (Schwarz, M., Lund, E. G., Setchell, K. D. R., Kayden, H. J., Zerwekh, J. E., Bj?rkhem, I., Herz, J., and Russell, D. W. (1996) J. Biol. Chem. 271, 18024-18031). We conclude that cholesterol 7alpha-hydroxylase is an essential enzyme for normal postnatal development.