Due to its high sensitivity and conductivity, electrotactile stimulation (ETS) on the tongue has proven to be a useful and technically convenient tool to substitute and/or augment sensory capabilities. However, most of its applications have only provided spatial attributes and little is known about (a) the ability of the tongue's sensory system to process electrical stimuli of varying magnitudes and (b) how modulation of ETS intensity affects subjects' ability to decode stimulus intensity. We addressed these questions by quantifying: (1) the magnitude of the dynamic range (DR; maximal comfortable intensity/perception threshold) and its sensitivity to prolonged exposure; (2) subjects' ability to perceive intensity changes; and (3) subjects' ability to associate intensity with angular excursions of a protractor's handle.
View Article and Find Full Text PDFThe pyrokinin/pheromone biosynthesis activating neuropeptide (PK/PBAN) family plays a multifunctional role in an array of important physiological processes in a variety of insects. An active core analog containing an (E)-alkene, trans-Pro isosteric component was evaluated in four disparate PK/PBAN bioassays in four different insect species. These bioassays include pheromone biosynthesis in the moth Heliothis peltigera, melanization in the larval Spodoptera littoralis, pupariation acceleration in the larval fly Neobellieria bullata, and hindgut contraction in the cockroach Leucophaea maderae.
View Article and Find Full Text PDFThe pyrokinin/pheromone biosynthesis activating neuropeptide (PK/PBAN) family plays a multifunctional role in an array of important physiological processes in insects, including regulation of sex pheromone biosynthesis in moths. A cyclic PK/PBAN analog (cyclo[NTSFTPRL]) retains significant activity on the pheromonotropic HevPBANR receptor from the tobacco budworm Heliothis virescens expressed in CHO-K1 cells. Previous studies indicate that this rigid, cyclic analog adopts a type I beta-turn with a transPro over residues TPRL within the core PK/PBAN region.
View Article and Find Full Text PDFBackground: The aim of this study was to evaluate the excitability of the vastus medialis muscle in children with lateral patellar instability, because it is assumed that, apart from restoring the elasticity of passive lateral restraints, the main goal of rehabilitation of this dysfunction is strengthening of the vastus medialis.
Materials And Methods: Measurements were done in 56 patients (mean age 15.9 years) in the study group and 38 patients (mean age 15.
CLA, a natural, highly hydrophobic cyclic nonapeptide with sequence c(Pro(1)-Pro(2)-Phe(3)-Phe(4)-Leu(5)-Ile(6)-Ile(7)-Leu(8)-Val(9)-), isolated from linseed oil, was found to possess a strong immunosuppressive activity comparable, in low doses, with that of CsA, with a mechanism that depends on the inhibition of the interleukin-1 and interleukin-2 action. Structural analysis of CLA and its related compounds has underlined that the presence of the tetrapeptide Pro-Pro-Phe-Phe sequence, the Pro-Pro cis amide bond, and the 'edge-to-face' interaction are possible important features for the immunosuppressive activity of CLA. To evaluate the role and significance of 'edge-to-face' interaction in the process of molecular recognition by receptors, we have synthesised three linear precursors and three cyclic analogues of CLA, in which one or both Phe residues have been replaced by beta(3)Phe residues.
View Article and Find Full Text PDFIEEE Trans Biomed Eng
October 2008
This paper describes a high-performance transconductance amplifier specifically designed for electrotactile (electrocutaneous) stimulation. It enables voltages up to +/-600 V to be produced at the output that will allow the psychophysiological performance associated with stimulation of the fingertip using various stimulation waveforms to be studied more thoroughly. The design has a transconductance of up to 20 mA/V, an 8.
View Article and Find Full Text PDFBackground: Left ventricular (LV) thrombus related to acute myocardial infarction (AMI) has been rarely diagnosed since primary stenting has become the routine treatment. The salvage of myocardium at risk is considered as a reason for low frequency of this complication. The impact of glycoprotein IIb/IIIa inhibitors on LV thrombus formation remains unknown.
View Article and Find Full Text PDFBackground: There are limited data referring to the incidence of left ventricle (LV) thrombus formation after successful primary percutaneous coronary intervention (PCI) with stenting, which is now the treatment of choice in patients with acute myocardial infarction (AMI). Previously reported results were often based on low or heterogeneous patient populations.
Methods: To evaluate the prevalence of LV thrombus in the early period of AMI, 2,911 patients who had undergone successful primary stenting were retrospectively studied.
The multifunctional 'insect kinins' share the evolutionarily conserved C-terminal pentapeptide motif Phe-X1-X2-Trp-Gly-NH2, where X1=His, Asn, Ser, or Tyr and X2=Ser, Pro, or Ala; and are associated with the regulation of diuresis in a variety of species of insects. We previously reported the functional expression of a southern cattle tick (Boophilus microplus) G protein-coupled receptor that is activated by insect kinins. Four different stereochemical variants of each of the 4-aminopyroglutamic acid (APy) and tetrazole moieties, mimics of a cis-peptide bond, type VI beta-turn in insect kinins were now evaluated on the expressed tick receptor using a calcium bioluminescence plate assay.
View Article and Find Full Text PDFPol Merkur Lekarski
April 2007
Unlabelled: Before the widespread use of primary percutaneous coronary intervention (PCI) and glycoprotein llb/Illa inhibitors (GP lIb/Illa) the left ventricular thrombus (LVT) was reported to complicate up to 20% of acute myocardial infarctions (AMI). It still remains unknown how these modern therapies impact on LVT occurrence.
The Aim Of The Study: We tried to define the frequency of LVT among the patients (pts) who underwent successful primary PCI and received aggressive antiplatelet therapy at the same time.
The purpose of the paper is to present assumptions underlying the evidence based approach in health promotion. As a starting point the development of the evidence based approach successively implemented since 1980's in medicine was taken. Its fast development effected with transitioning principles of the approach to other areas directly connected to health.
View Article and Find Full Text PDFThe paper is an effort to find what determined the success of Polish health reform implemented in 1999 in the Silesian Voivodeship. The problem has been referred to "social capital" proposed by R. Putnam; the first part of the article contains a short description of this approach.
View Article and Find Full Text PDFTransvenous pacemaker lead malposition in the left ventricle is a rare complication of pacemaker implantation however, at the moment of diagnosis poses the serious therapeutic problem. The usual morphology for paced events originating from the right ventricle has a left bundle branch block pattern, but sometimes right bundle branch block (RBBB) configuration is identified. The report describes two cases of RBBB configuration in the electrocardiogram (ECG) after pacemaker implantation.
View Article and Find Full Text PDFThe present work is part of our studies aimed at clarifying the influence of steric constraints in the N-terminal part of arginine vasopressin (AVP) and its analogs on the pharmacological activity of the resulting peptides. We describe the synthesis of eight new analogs of AVP or [3-mercaptopropionic acid (Mpa)]AVP (dAVP) substituted at positions 2 and 3 or 3 and 4 with two diastereomers of 4-aminopyroglutamic acid. The steric constraints provided by this modification turned out, however, so strong that all the peptides were inactive in all of the bioassays (pressor, antidiuretic and uterotonic tests).
View Article and Find Full Text PDFThe insect kinins are present in a wide variety of insects and function as potent diuretic peptides in flies. A C-terminal aldehyde insect kinin analog, Fmoc-RFFPWG-H (R-LK-CHO), demonstrates stimulation of Malpighian tubule fluid secretion in crickets, but shows inhibition of both in vitro and in vivo diuresis in the housefly. R-LK-CHO reduced the total amount of urine voided over 3 h from flies injected with 1 microL of distilled water by almost 50%.
View Article and Find Full Text PDFThe insect kinins are present in a wide variety of insects and function as potent diuretic peptides, though they are subject to rapid degradation by internal peptidases. Insect kinin analogs incorporating stereochemical variants of (2S,4S)-4-aminopyroglutamate (APy), a cis-peptide bond motif, demonstrate significant activity in a cricket diuretic assay. Insect kinin analogs containing (2R,4R)-APy, (2S,4R)-APy and (2S,4S)-APy are essentially equipotent on an insect diuretic assay, with EC(50) values of about 10(-7)M, whereas the (2R,4S)-APy analog is at least 10-fold more potent (EC(50) = 7 x 10(-9)M).
View Article and Find Full Text PDFElectrovibration is the tactile sensation of an alternating potential between the human body and a smooth conducing surface when the skin slides over the surface and where the current is too small to stimulate sensory nerves directly. It has been proposed as a high-density tactile display method, for example to display pictographic information to persons who are blind. Previous models for the electrovibration transduction mechanism are based on a parallel-plate capacitor in which the electrostatic force is insensitive to polarity.
View Article and Find Full Text PDFObjectives: We sought to determine the usefulness of ambulatory 24-hour Holter monitoring in detecting asymptomatic pacemaker (PM) malfunction episodes in patients with dual-chamber pacemakers whose pacing and sensing parameters were proper, as seen in routine post-implantation follow-ups. This aspect has not been widely discussed so far.
Methods And Results: Ambulatory 24-hour Holter recordings [HM] were performed in 100 patients with DDD pacemakers one day after the implantation.
Primary amyloidosis is a systemic disorder caused by the clonal production and tissue deposition of immunoglobulin light chain proteins. The disease symptoms are typical of multisystem failure. Common presenting features include nephrotic syndrome, hepatomegaly, sensomotor peripheral neuropathy and, in the case of cardiac involvement, congestive heart failure.
View Article and Find Full Text PDFBackground: A ciliary block is the rarer cause of angle block glaucoma. In order to choose the appropriate therapy, however, it is crucial to make the correct diagnosis. We report on a patient who suffered from recurrent increases of intraocular pressure while having renal dialysis.
View Article and Find Full Text PDFWe report the case of a patient who experienced recurrent elevations of intraocular pressure during haemodialysis. We measured a rise in intraocular pressure of 10-12 mmHg after dialysis. The lens showed intumescence, and a ciliary block was detected by means of Orbscan II.
View Article and Find Full Text PDFMed Biol Eng Comput
March 2005
A comparison of auditory and visual perception of scatterplots showed similar correlation estimation performance in both modalities. The present study replicated this experiment using electrotactile (electrocutaneous) presentation of scatterplots on the fingertips and abdomen, as well as visual presentation. The correlation estimation task resulted in a slightly poorer performance on electrotactile scatterplots (abdomen r = +0.
View Article and Find Full Text PDFThe aliphatic amino diacid alpha-aminosuberic acid can function as an effective, stable mimic of the hydrolysis-susceptible Tyr(SO3H) group in sulfakinin neuropeptide analogs for both hindgut contractile activity in cockroach and food intake-inhibition activity in the desert locust. In the analog, the acidic sulfate group is replaced with an acidic carboxyl group. The degree of activity of sulfakinin analogs is correlated with the carboxyl/alpha-carbon distance in the cockroach hindgut contractile assay.
View Article and Find Full Text PDFLinear and cyclic cyclolinopeptide A (CLA) analogues containing alpha-hydroxymethylleucine (HmL) in positions 1, 4, and 1&4, and alpha-hydroxymethylvaline (HmV) in position 5, were synthesized by the solid-phase peptide strategy and cyclized with the 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide/1-hydroxy-7-azabenzotriazole (EDC/HOAt) reagent. The peptides were examined for their immunosuppressive activity in the lymphocyte proliferation assays (LPA). Only HmL-containing peptides demonstrated at about 25% lower immunosuppressive activity, but they are four times more soluble in water solutions than the native CLA.
View Article and Find Full Text PDFThe insect kinins are potent diuretic peptides that preferentially form a cis-Pro, type VI beta-turn. An insect kinin analog containing (2S,4S)-4-aminopyroglutamate, a novel cis-peptide bond, type VI beta-turn motif, demonstrates significant activity in the physiological range in a cricket diuretic assay. This is the first instance of a 4-aminopyroglutamate analog of a peptide with a preference for a type VI turn that demonstrates significant bioactivity.
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