Comb-shaped polymer-based Dry electrodes for EEG/ECG measurements with high user comfort.

Soft, comfortable polymer-based dry electrodes are fabricated. Impedance and biopotential measurements are carried out to compare the performance of conventional gel electrodes with our dry electrodes. The impedance of our dry electrodes is reduced by adding more conductive additives to the polymer material. To further lower the impedance, two skin pretreatment techniques are evaluated regarding their influence on skin impedance. However, these techniques are found to have only temporary beneficial effects. Finally biopotential measurements (both ECG and EEG) are performed using our soft polymer electrodes. The ECG signal acquired with both gel and our polymer electrodes demonstrates high degree of similarity. Therefore, heart beat detection is straightforward. To enable monitoring of EEG signals with smaller amplitudes, our dry electrodes need to be combined with pre-amplifiers. Initial EEG tests show that the alpha waves are clearly identifiable with the dry electrodes when subjects close their eyes. Based on the results, combining with sophisticated signal acquisition electronics, the dry electrodes provide a high user comfort solution for high quality biopotential measurements, even on very hairy skin.

Oxidation of methionine residues in equine growth hormone by Chloramine-T.

1. Reactivity of methionine residues towards Chloramine-T was studied in the equine growth hormone. 2. With a 20.0-fold molar excess of reagent over methionine, full oxidation of the four residues of the protein is achieved. 3. Methionine 4 is the most reactive group, followed by methionines 72 and 178--methionine 123 being the less reactive residue. 4. As judged by circular dichroism spectra and binding assays, protein conformation and binding capacity to specific receptors remains unchanged even after full oxidation of all four methionine residues. 5. Results agree with data previously obtained with bovine growth hormone.

Expression of a mutant regulatory subunit of cAMP-dependent protein kinase in the Caco-2 human colonic carcinoma cell line.

Caco-2 human colonic carcinoma cells were transfected with an expression vector encoding a mutant form of RI (regulatory subunit of the type 1 cAMP-dependent protein kinase), driven by the metallothionein 1 promoter. A stable transformant was isolated that expressed the mutant RI gene in a Zn(2+)-inducible manner. The consequences of the RI mutation on cAMP-dependent protein kinase activity, cell division, and regulation of chloride efflux were examined. When grown in the absence of ZnSO4, protein kinase activity in the transformant was stimulated 2.5-fold by cAMP and approached the levels of cAMP-dependent protein kinase activity seen in parental Caco-2 cells; when treated with ZnSO4, cAMP-dependent protein kinase activity in the transformant was inhibited by 60%. In the absence of ZnSO4 the transformant grew with the same doubling time and to the same saturation density as the untransformed parent. In the presence of ZnSO4 the transformant exhibited a cAMP-reversible inhibition of cell division, indicating that a functional cAMP-dependent protein kinase was required for the growth of these cells in culture. Induction of the mutant RI gene also abolished forskolin-stimulated chloride efflux from these cells, suggesting obligatory roles for cAMP and cAMP-dependent protein kinase in forskolin's actions on chloride channel activity. We anticipate that this transformant will be useful for further studies on the roles of cAMP and cAMP-dependent protein kinase in the regulation of intestinal epithelial cells, including regulation of cell proliferation and differentiation, and regulation of chloride channel activity by neurohormones and neurotransmitters.

[The importance of the adaptation period in medical rehabilitation in attaining definitive work capacity]. / Vaznost perioda adaptacije u medicinskoj rehabilitaciji za postizanje definitivne radne sposobnosti.

Medical rehabilitation may bring functional improvement up to a level permitted by damages of the locomotor system, especially by those of the joints. At the start of rehabilitation the restricted motions are initially very painful and provoke an intensive protective spasm. In the course of rehabilitation the range of motions becomes more extensive, motions are less and less painful, until finally the pain disappears. The final condition which is medically considered as definite is the contracture due to damages of the joints and periarticular tissues. The process of rehabilitation includes a period of worker's adjustment to the new conditions. The worker learns to use the damaged part of the body in a different manner by means of adaptation, substitution and other mechanisms of adjustment. That is a period of voluntary control of the damaged parts, and yet some certain tenderness or pain is present. Adaptation is supposed to develop new neural patterns, a new sequence and coordination of motions, and consequently new motion schemes. So voluntary use of the damaged body part is substituted by automatic and painless control. Definite evaluation of working capacity and residual working ability is possible only after the period of adaptation.

[Significance of cardiotocography and amnioscopy in establishing indications for cesarean section]. / Znacaj kardiotokografije i amnioskopije kod postavljanja indikacija za sectio caesarea

In the period of 2 years (1974-1975), out of 11,672 deliveries, 398 (3.41%) were induced by cesarean section. An important role in inducing labour surgically was played by cardiotocography and amnioscopy (in addition to other methods), i.e. in 84.22% (366 cases). At present it appears necessary to use cardiotocography and aminiscopy both in the last trimester and during the labour itself, so as to facilitate the estimation of the degree of a possible danger for the foetus.