Collaborative Learning in Higher Education: Evoking Positive Interdependence.

Collaborative learning is a widely used instructional method, but the learning potential of this instructional method is often underused in practice. Therefore, the importance of various factors underlying effective collaborative learning should be determined. In the current study, five different life sciences undergraduate courses with successful collaborative-learning results were selected.

Physiological effects of homeopathic medicines in closed phials--a critical evaluation.

Background: Phials containing high dilutions of homeopathic remedies are commonly utilized in diagnostic tools in combination with electro acupuncture measuring electrical conductivity of the skin. The present research aimed to elucidate the interaction of the homeopathic remedy and the human organism.

Method: The study protocol included the transition of a healthy subject to a diseased state utilizing a sub-harmful dose of a toxin.

Hormesis and Cellular Quality Control: A Possible Explanation for the Molecular Mechanisms that Underlie the Benefits of Mild Stress.

In contrast to the detrimental action of severe stress conditions, the beneficial effects of mild stress, known as hormesis, is increasingly discussed and studied. A variety of applications for hormesis in risk assessment processes, anti-ageing strategies and clinical therapies have been proposed. The molecular mechanisms underlying the phenomenon of hormesis, however, are not yet fully understood.

Postconditioning hormesis put in perspective: an overview of experimental and clinical studies.

A beneficial effect of applying mild stress to cells or organisms, that were initially exposed to a high dose of stress, has been referred to as 'postconditioning hormesis'. The initial high dose of stress activates intrinsic self-recovery mechanisms. Modulation of these endogenous adaptation strategies by administration of a subsequent low dose of stress can confer effects that are beneficial to the biological system.

Postconditioning hormesis and the similia principle.

Postexposure conditioning, as a part of hormesis, involves the application of a low dose of stress following exposure to a severe stress condition. The beneficial effect of a low level of stress in postconditioning hormesis is illustrated by a number of examples found in experimental and clinical research. Depending on whether the low-dose stress is of the same type of stress or is different from the initial high-dose stress causing the diseased state, postconditioning is classified as homologous or heterologous, respectively.

An undergraduate course to bridge the gap between textbooks and scientific research.

This article reports on a one-semester Advanced Cell Biology course that endeavors to bridge the gap between gaining basic textbook knowledge about cell biology and learning to think and work as a researcher. The key elements of this course are 1) learning to work with primary articles in order to get acquainted with the field of choice, to learn scientific reasoning, and to identify gaps in our current knowledge that represent opportunities for further research; 2) formulating a research project with fellow students; 3) gaining thorough knowledge of relevant methodology and technologies used within the field of cell biology; 4) developing cooperation and leadership skills; and 5) presenting and defending research projects before a jury of experts. The course activities were student centered and focused on designing a genuine research program.

Postconditioning hormesis and the homeopathic Similia principle: molecular aspects.

Postexposure conditioning, as a part of hormesis, involves the application of a low dose of stress following exposure to a severe stress condition. Depending on whether the low-dose stress is of the same type of stress or is different from the initial high-dose stress causing the diseased state, postconditioning can be classified as homologous or heterologous, respectively. In clinical homeopathy, the same distinction is found between isopathic and homeopathic application of low-dose substances.

The similia principle: results obtained in a cellular model system.

This paper describes the results of a research program focused on the beneficial effect of low dose stress conditions that were applied according to the similia principle to cells previously disturbed by more severe stress conditions. In first instance, we discuss criteria for research on the similia principle at the cellular level. Then, the homologous ('isopathic') approach is reviewed, in which the initial (high dose) stress used to disturb cellular physiology and the subsequent (low dose) stress are identical.

The influence of adaptogens on ultraweak biophoton emission: a pilot-experiment.

In the present study, the effect of plant adaptogens (Rhodiola rosea and ADAPT-232) on human photon emission has been determined. In a randomized double blind placebo-controlled study, 30 subjects were randomly assigned to three groups: one group (n = 10) taking placebo pills, one group (n = 10) taking Rhodiola rosea (SHR-5) pills and one group (n = 10) taking ADAPT-232 supplements (the latter being a fixed combination of the following three adaptogens: Eleutherococcus senticosus, Rhodiola rosea and Schisandra chinensis). All subjects underwent measurements to determine ultra-weak photon emission (UPE) of the dorsal side of their hands using a photon-counting device, both before and after a week of taking the supplements.

Free radicals and low-level photon emission in human pathogenesis: state of the art.

Convincing evidence supports a role for oxidative stress in the pathogenesis of many chronic diseases. The model includes the formation of radical oxygen species (ROS) and the misassembly and aggregation of proteins when three tiers of cellular defence are insufficient: (a) direct antioxidative systems, (b) molecular damage repairing systems, and (c) compensatory chaperone synthesis. The aim of the present overview is to introduce (a) the basics of free radical and antioxidant metabolism, (b) the role of the protein quality control system in protecting cells from free radical damage and its relation to chronic diseases, (c) the basics of the ultraweak luminescence as marker of the oxidant status of biological systems, and (d) the research in human photon emission as a non-invasive marker of oxidant status in relation to chronic diseases.

Plant adaptogens increase lifespan and stress resistance in C. elegans.

Extracts of plant adaptogens such as Eleutherococcus senticosus (or Acanthopanax senticosus) and Rhodiola rosea can increase stress resistance in several model systems. We now show that both extracts also increase the mean lifespan of the nematode C. elegans in a dose-dependent way.

Possible use of adaptation to hypoxia in Alzheimer's disease: a hypothesis.

Disorders in memory and other cognitive functions in Alzheimer's disease (AD) may result from an exhaustion of adaptive reserves in the brain. Therefore it is a challenge to find methods to increase the adaptive reserve of the organism to combat AD. Excitotoxicity, Ca2+ homeostasis disruptions, oxidative stress, disturbed synthesis of NO, and impaired cerebral circulation are suggested as key pathogenic factors of AD.

Histamine dilutions modulate basophil activation.

Background: In order to demonstrate that high dilutions of histamine are able to inhibit basophil activation in a reproducible fashion, several techniques were used in different research laboratories.

Objective: The aim of the study was to investigate the action of histamine dilutions on basophil activation.

Methods: Basophil activation was assessed by alcian blue staining, measurement of histamine release and CD63 expression.

Adaptation to heat of cardiomyoblasts in culture protects them against heat shock: role of nitric oxide and heat shock proteins.

Dosed adaptation to environmental factors is an efficient non-drug means for increasing the resistance of organs or the body as a whole. We demonstrated earlier that nitric oxide (NO) plays an important role in adaptive defense of the organism, in particular due to activation of heat shock protein (HSP) synthesis. A key question remained open--to what extent the formation of adaptive defense depends on central mechanisms and to what extent on the intracellular mechanisms immediately responding to the adapting factor, and whether the NO-dependent activation of HSP synthesis plays a role in adaptation of isolated cells.

Phyto-adaptogens protect against environmental stress-induced death of embryos from the freshwater snail Lymnaea stagnalis.

The main purpose of the studies presented in this paper is twofold: 1) to evaluate whether phyto-adaptogens (Acanthopanax senticosus and Rhodiola rosea) are able to exert a protective action against stress-induced death of embryos of the pond snail Lymnaea stagnalis; and 2) whether a possible protective action by phyto-adaptogens can be explained by the induction of heat shock proteins. Enhancement in resistance by phyto-adaptogens was studied by applying plant extracts for a period of 20 hours to 3-day old larvae of the pond snail Lymnaea stagnalis. Subsequently they were exposed to a high and toxic dose of different environmental stressors.

Heat shock response by cells treated with azetidine-2-carboxylic acid.

The purpose of this study is to reinvestigate the heat shock response in cells treated with the antimetabolite azetidine-2-carboxylic acid (azetidine), an analogue of proline. Previous studies could not clearly discriminate between the progressive thermosensitization caused by amino acid analogues and a parallel induction of thermotolerance by heat shock. Incubation of H35 cells with 2.

The effect of temperature and protein synthesis on the renaturation of firefly luciferase in intact H9c2 cells.

A mild increase in temperature that does not exert an effect on tolerance development or synthesis of heat shock proteins (Hsps) in control cells can stimulate these processes when applied to cells that have previously been heat shocked. To study the underlying mechanism of this effect, H9c2 cells were stably transfected with the gene encoding firefly luciferase (Luc). Heat-shock-induced inactivation of Luc and its subsequent reactivation is frequently used as a model for cellular protein denaturation and renaturation.

Stimulation of survival capacity in heat shocked cells by subsequent exposure to minute amounts of chemical stressors; role of similarity in hsp-inducing effects.

A brief and moderate heat shock to Reuber H35 hepatoma cells causes a rapid increase in the synthesis of heat shock proteins (hsp) and initiates the development of thermotolerance, which results in an increased ability to survive exposure to otherwise lethal temperatures. We now demonstrate that low doses of various chemical stressors (arsenite, cadmium, mercury, lead, copper, menadione and diethyldithiocarbamate (ddtc)), at concentrations that do not exert any effect in control cultures, are able to enhance the synthesis of hsps and to stimulate the development of thermotolerance when applied to cultures which were pretreated with a mild heat shock. The degree of stimulation appears to be stressor-specific, which is not only observed in the ensuing development of thermotolerance but also in the enhancement of the heat shock-induced synthesis of stress proteins.

Dinitrosyl iron complexes with thiol-containing ligands and S-nitroso-D,L-penicillamine as inductors of heat shock protein synthesis in H35 hepatoma cells.

The concentration-dependent effect of various nitric oxide donors on synthesis of different heat shock proteins was evaluated in Reuber H35 hepatoma cells and their heat shock protein-inducing ability was compared with the effect of a heat shock. A 6 h incubation of H35 cells with the dimeric (diamagnetic) form of dinitrosyl iron complex with glutathione or N-acetyl-L-cysteine activated synthesis of various heat shock proteins, heat shock protein 28, 32, 60, 70, 90 and 100. Synthesis of these proteins was evaluated by [35S]methionine and [35S]cysteine labelling with subsequent separation of proteins by polyacrylamide gel electrophoresis.

The role of hsp70 in protection and repair of luciferase activity in vivo; experimental data and mathematical modelling.

The stably transfected rat cell line HR24 expressing high levels of the inducible human hsp70 and its parental cell line Rat-1 were used for in vivo studies to analyse the role of hsp70 during thermal protein denaturation and the subsequent renaturation. In order to monitor denaturation and renaturation of a cellular protein in vivo, both cell lines were transiently transfected with firefly luciferase (Luc). The continuous monitoring of Luc activity during and after heat stress allowed a detailed analysis of the inactivation and reactivation kinetics in cells grown in monolayers.

Stressor-specific enhancement of hsp induction by low doses of stressors in conditions of self- and cross-sensitization.

In this paper, the pattern of induction of heat shock proteins (hsps) was studied in cultured Reuber H35 rat hepatoma cells by sequential application of different stressors. We analyzed whether a specific stress condition is able to induce an enhanced sensitivity to a subsequent application of a low dose of either the same or another stressor (self-sensitization and cross-sensitization, respectively). As a measure of sensitization, the stimulation of hsp induction was employed.

The similia principle as a therapeutic strategy: a research program on stimulation of self-defense in disordered mammalian cells.

The similia principle is considered to be the essence of homeopathy. This article describes a research program for study of the similia principle in cultured mammalian cells. This systematic program with its rather simple research model was set up ultimately to contribute to the design of studies of the similia principle with more complex organisms such as humans.

Enhancement of the stress response by minute amounts of cadmium in sensitized Reuber H35 hepatoma cells.

The aim of this study was to determine whether the cadmium-induced cellular stress response can be modulated by the subsequent application of low concentrations of the same ion. It is shown that exposure of Reuber H35 rat hepatoma cells to cadmium concentrations of 10 or 30 microM for 1 h leads to a biphasic change in their sensitivity towards a second exposure to cadmium, an initial sensitization is followed by development of tolerance towards the secondary treatment with cadmium. Furthermore, incubations for 1 h in the presence of 10 microM of cadmium induce the synthesis of the major heat shock proteins except for hsp60.