Multimedia support in the education of clinical and health care disciplines :: Portal of Faculty of Medicine, Comenius University

Hypersensitivity reactions, types II till V

A principal biological role of the immune system is an eradication of both external as well internal violators of integrity of the organism. External „enemies“ are represented mainly by germs; those of internal origin belong especially to potentially malignant cells that appear in our organisms as the results of a breakdown of their replication mechanisms.Under certain circumstances, however, the immune response can have deleterious effects, resulting in significant tissue damage or even death. This inappropriate immune response is termed hypersensitivity. Although the word hypersensitivity implies an increased response, the response is not always heightened but may, instead, be an inappropriate immune response to an antigen.
Several forms of hypersensitive reaction can be distinguished, reflecting differences in the effector molecules generated in the course of the reaction. In immediate hypersensitive reactions different antibody isotypes induce different immune effector molecules. IgE antibodies, for example, induce mast cell degranulation with release of histamine and other biologically active molecules. IgG and IgM antibodies, on the other hand, induce hypersensitive reactions by activating complement. The effector molecules in these reactions are the membrane-attack complex and such complement split products as C3a, C4a and C5a. In delayed-type hypersensitivity reactions, the effector molecules are various cytokines secreted by T helper cells and macrophages. As it became clear that different immune mechanisms can give rise to hypersensitive reactions, P. G. H. Gell and R. R. A. Coombs proposed a classification scheme in which hypersensitive reactions are divided into four types, I, II, III, and IV, each involving distinct mechanisms; later type V was added. Antibodies mediate four types of hypersensitive reactions: IgE-mediated (type I), cytotoxic (type II), immune complex (type III), and stimulatory/inhibitory (type V) hypersensitivity, respectively. T cells initiate the last type of hypersensitivity (type IV) and clinical symptoms appear more days after exposure; it is therefore referred to as delayed-type hypersensitivity (DTH). However, a great deal of com¬plexity exists within each type of reactions that blurs the boundaries between them.
 

Autoimmunity and autoimmune disease

The principal role of the immune system is to protect the organism from principally two the most dangerous events potentially threatening our life, i.e. infection and malignancy. However, sometimes the immune system instead of reacting against foreign and aberrant self-antigens can attack self-molecules. This inappropriate response of the immune system against self-components is termed autoimmunity.
There are 70 - 80 autoimmune disorders known till now and app. 5% of Caucasoid population suffers from them. Our understanding of autoimmunity has improved greatly during the last two decades, mainly because of the development of a variety of animal models of these diseases and the identification of genes that may predispose to autoimmunity. Nevertheless, the aetiology of most human autoimmune diseases remains still obscure.
The term “autoimmunity” is often erroneously used for a disease in which immune reactions accompany tissue injury; they are “a by-product” of a release of self-antigens to circulation without causing any damage; moreover, these “autoimmune reactions” help to degrade them and to remove them from the body.

Blood physiology for the dentistry students

Composition and functions of blood. Erythrocytes and their functions. Blood groups. Platelets and haemocoagulation. Leukocytes and immunity. Composition and function of plasma. Osmotic and oncotic pressure. Haematopoiesis.

Foeto-maternal relationships. The immune system of newborns

A success of pregnancy depends on a proper implantation and induction of immune tolerance. The immune system secures it by various mechanisms – special cells, cytokines, HLA molecules, peripheral tolerance take part in.

The immune system of the newborn has also its own specifics as it matures relatively long time till it reaches the same protective ability as characteristic for adults.

Immunodeficiencies. AIDS

The lecture deals with primary and secondary immunodefeciencies. It gives an overview on general clinical manifestations and their divisions according to the type of the immune functions defects. Must of the lecture devotes to AIDS.     

Structure of Matter From Biophysical Point of View

The lecture „Structure of Matter From Biophysical Point of View“ is aimed to give a brief introduction to some applications of physics at microscopic level in medicine. It explains the fundamental problem of science, gives an overview of important stages in structure analysis, explains different structure and forms of matter, physical interactions, general properties and characteristics of matter, Heisenberg uncertainty principle, basic properties of elementary particles, the principle and usefulness of Schrödinger equation.

Dosimetry.

The lecture „Dosimetry - Measurement of Ionising Radiation“ is aimed to explain the term dosimetry and the basic quantities characterising the radiation from the aspect of their biological effects that allow to measure and to quantify them. Terms as dose, absorbed dose, absorbed dose rate, integral dose, equivalent dose, effective dose, kerma, kerma rate, exposure, exposure rate and connected formulas and physical units are explained.

Radioactivity

The lecture „Radioactivity“ is aimed to explain basic terms as radioactive isotopes, natural and artificial radioactivity, law of radioactive decay, half-life of decay (physical, biological, effective), mean life-time, activity and connected formulas and physical units.

Type I hypersensitivity (Allergy)

Type I hypersensitivity belongs to the most common disorder mediated by immune reactions; it affects app. more than 30% of all individuals in Caucasoid population. Type I hypersensitivity is commonly called allergy. It is characterised by rapid onset (hence the term immediate hypersensitivity), within minutes of antigen challenge, and results in conspicuous clinical symptoms.

Basic elements of electric circuits

The lecture „Basic elements of electric circuits“ is aimed to explain basic terms, quantities and units  It contains basic electrical values like electric current, electric resistance next measurement of electrical quantities and elements of electric circuit.

MEFANET

Network MEFANET (www.mefanet.cz)

This inter-university project had been prepared since 2006. The network of medical faculties (MEFANET) was finally established on 20th of June 2007 at the constitutive meeting of the Coordinating Council in Prague.

Medical faculties (MF) involved in the MEFANET project

• MF at the Masaryk University (Brno)
• MF at the Comenius University in Bratislava
• Jessenius MF in Martin at the Comenius University
• MF at the Pavol Jozef Šafárik University in Košice
• MF at the Palacky University in Olomouc
• 1. MF at the Charles University in Prague
• 2. MF at the Charles University in Prague
• 3. MF at the Charles University in Prague
• MF in Hradec Králové at the Charles University in Prague
• MF in Plzeň at the Charles University in Prague

Central gate of the MEFANET project

http://portal.mefanet.cz/index-en.php

Some aspects of the epidemiology and prognosis of zoonotic toxocarosis

Incidence of toxocarosis in Slovakia 1977-1990 showed an exponential increase with an accessory cycling, having 7-8 years period length.                                                 

Half century of leptospiroses in Slovakia and the solar spots

Annual incidence rates of 3157 cases of leptospiroses recorded within 1949 and 2004, caused by the main serovars ificant or borderly significant periodicities, resembling those known from solar and geomagnetic activity, were identified. By comparing them with the time course of Wolf numbers, an almost exact reciprocity of maxima and minima of Wolf numbers and leptospiroses was disclosed. It is hypothetized that the epizoonotic character of these diseases supports the putative dependence of its manifestation upon the nature including the sun. Surprisingly, no similar results were found, so far, in the world scientific registers.

Solar activity, revolutions and cultural prime in the history of mankind

Russian scientist Tchijevskij investigated almost 100 years ago (suggested for Nobel prize) relationships between solar activity, cycling with the period around 11 years, and the status of mankind. He found „social excitation“, as revolutions and wars, at the time of solar maxima and peaceful activities like flourishing of arts at minima.The present paper explores whether such a parallelism applies also to the 500 years´ (semimillenial) cycling of solar activity. The present author obtained, using the cosinor analysis, significant positive anwer. It is hypothesized that one of the responsible factors could be solar impact on geomagnetic field.

From the descriptive towards inferential statistics: Hundred years since conception of the Student´s t-distribution

The 100th anniversary of the Student´s statistical t-distribution is commemorated.                                                                                                                                                                              

Cerebral infarction versus solar and geomagnetic activity: a cross-regression study

The monthly registered Wolf numbers (i.e the numbers of sunspots), solar flares index and Ap index of the geomagnetic activity values display negative regression dependence („negatively correlate“) upon the monthly observed numbers of new cases of cerebral infarction.This phenomenon is present with delays from -6 months (infarction before the cosmogeophysical measurement) up to + 17 months (infarction after the cosmogeophysical measurement),with the most pronounced relationship for delay of +5 months.