Iron-oxide minerals in the human tissues.

Iron is critically important and highly regulated trace metal in the human body. However, in its free ion form, it is known to be cytotoxic; therefore, it is bound to iron storing protein, ferritin. Ferritin is a key regulator of body iron homeostasis able to form various types of minerals depending on the tissue environment. Each mineral, e.g. magnetite, maghemite, goethite, akaganeite or hematite, present in the ferritin core carry different characteristics possibly affecting cells in the tissue. In specific cases, it can lead to disease development. Widely studied connection with neurodegenerative conditions is widely studied, including Alzheimer disease. Although the exact ferritin structure and its distribution throughout a human body are still not fully known, many studies have attempted to elucidate the mechanisms involved in its regulation and pathogenesis. In this review, we try to summarize the iron uptake into the body. Next, we discuss the known occurrence of ferritin in human tissues. Lastly, we also examine the formation of iron oxides and their involvement in brain functions.

Analyses of tumor cells by mathematical models.

In this contribution we present graph theoretical approach to image processing focus on biological data. We use the graph cut algorithms and extend them for obtaining segmentation of biological data. We deal with tumor brain cells and rats brain to show the existence and presence of inflammatory molecules. We introduce a completely new method for filtering of data (Tab. 3, Schema 4, Fig. 7, Ref. 13). Keywords: graph cuts, segmentation, tumore analyses of cells, computer morphometry.

Pineal gland calcification under hypoxic conditions.

The pineal gland (glandula pinealis) is neuroendocrine gland located at the epithalamus of the brain secreting melatonin. The aim of this study was to explore effects of prenatal hypoxia in rats at the age of 33 weeks on the occurrence of pineal gland calcification. Distribution and chemical composition of calcerous material by light, scanning and transmission electron microscopy was investigated. Melatonin concentrations in blood plasma by direct radioimmunoassay were measured. Rats were exposed to prenatal hypoxia for 12 h at day 20 of development and second group to prenatal hypoxia for 2x8 h at days 19 and 20 of development. Vacuoles of intracellular edema in the pineal samples after 12 h hypoxia were found. Their size ranges up to 30 µm. Some of them were filled with the flocculent and fibrous material. Samples of pineal glands after 2 x 8 h hypoxia revealed the pericellular edema of pinealocytes. The amount of calcium rich particles in 2 x 8 h hypoxia group was lower than in 12 h hypoxia group. Plasma melatonin levels did not differ between control and both hypoxia groups. We concluded that calcification is a process induced by osteoblasts and osteocytes with melatonin as a promotor and it is favored under hypoxic conditions.

Elevated age-related cortical iron, ferritin and amyloid plaques in APP(swe)/PS1(deltaE9) transgenic mouse model of Alzheimer's disease.

Iron is very important element for functioning of the brain. Its concentration changes with aging the brain or during disease. The aim of our work was the histological examination of content of ferritin and free iron (unbound) in brain cortex in association with Abeta plaques from their earliest stages of accumulation in amyloid plaque forming APP/PS1 transgenic mice. Light microscopy revealed the onset of plaques formation at 8-monthage. Detectable traces of free iron and no ferritin were found around plaques at this age, while the rate of their accumulation in and around Abeta plaques was elevated at 13 months of age. Ferritin accumulated mainly on the edge of Abeta plaques, while the smaller amount of free iron was observed in the plaque-free tissue, as well as in and around Abeta plaques. We conclude that free iron and ferritin accumulation follows the amyloid plaques formation. Quantification of cortical iron and ferritin content can be an important marker in the diagnosis of Alzheimer's disease.

Iron deposition in rabbit cerebellum after exposure to generated and mobile GSM electromagnetic fields.

BACKGROUND: Mobile phone application may cause structural, functional changes and accumulation of toxic elements in brain. OBJECTIVES: The aim of this study was to investigate iron accumulation in rabbit cerebellum after exposure to RF EMF with light and scanning electron microscopy. MATERIALS AND METHODS: Histochemical analysis of iron distribution by light and electron microscopy with energy-dispersive microanalysis was used. RESULTS: Light microscopy revealed dystrophic changes of Purkinje cells in irradiated groups and iron deposits located in various parts of cerebellum. Deposits consists of C, O, Na, Mg, Al, Si, P, S, Cl, Ca and Fe. CONCLUSION: Our experiment revealed structural changes of Purkinje cells and iron and aluminium accumulations in stratum granulosum of rabbit's cerebellum after exposure to RF EMF (Fig. 6, Ref. 33).

Iron and its relation to glycoconjugates in human globus pallidus.

Iron and eosinophilic, argyrophilic spheroid structures of glycoconjugates are observed in the pallido-nigral system of human and nonhuman primates. In the present study, we map the localization and distribution of ferritin and hemosiderin and their relation to neutral and acidic (sulphated and carboxylated) glycoconjugates in human globus pallidus. We investigated tissues of human globus pallidus without any motor abnormalities and psychiatric symptoms. Acidic (Alcian blue, AB pH 2.5) and neutral glycoconjugates (PAS reaction) showed spheroid deposits with the size of 5-15 µm. Staining reaction utilizing AB (pH 1.0) displays sulphated fibers and highly sulphated (AB pH 0.5) glycoconjugates round deposits. AF/AB pH 2.5 for separating sulphated from carboxylated glycoconjugates revealed the presence of both sulphated and carboxylated glycoconjugates. Perls' and Turnbull's positive reaction showed the presence of Fe(III) and Fe(II) (hemosiderin) and Ag-NOR reaction showed ferric phosphate (ferritin) deposits. Scanning electron microscope with microanalysis revealed the iron in glycoconjugates globular deposits. We suppose the presence of glycoconjugates in the samples is the result of elimination and inactivation of iron as inductor of reactive oxygen species. They can be a useful neuroprotective agent in CNS degradation (Tab. 2, Fig. 7, Ref. 44).

Neuron-specific enolase in the intestinal wall in Crohn´s disease.

The authors described the localization of neuron-specific enolase in the intestinal wall in Crohn´s disease. We have used samples obtained by biopsy from the colon lining of five people affected by Crohn's disease for our examination. We have processed samples using the formol paraffin technique. From paraffin blocks, we have prepared histological sections approximately 5 µm thick. For immunohistochemic examinations, we have revitalised the sections by acquiring the heat-induced epitope. We detected NSE by monoclonal mouse antibodies against human neuron-specific enolase, clone BBS/NC/VI-H14 (DakoCytomation, Denmark) (Fig. 4, Ref. 7).

Iron-rich complexes in human spleen in hereditary spherocytosis.

OBJECTIVE: Tissue iron plays an important role in the development of certain diseases. Although it is one of biogenic elements, its excess induces the reactive oxygen species (ROS) formation. The aim of the present work is to examine the protection against free or loosely bound iron from the view of morphology and chemical composition of iron-rich complexes in human spleen tissues with hereditary spherocytosis (HS) by scanning and transmission electron microscope with energy-dispersive microanalysis (EDX). RESULTS: The examination of human spleen tissues by scanning and transmission electron microscope showed covering of iron-rich particles. EDX revealed many iron-rich complexes of multi-element composition in HS samples with sulphur and phosphorus as the major elements. Detection was negative in the reference samples. CONCLUSION: The covering of iron-rich particles can be explained by elimination and isolation of ferritin/iron complexes from surrounding environment to prevent the ROS formation. Sulphur, phosphorus and their compounds are probably the most significant elements that influence the ROS formation (Fig. 5, Ref. 16). Full Text in PDF www.elis.sk.

Iron accumulation in human spleen in autoimmune thrombocytopenia and hereditary spherocytosis.

BACKGROUND: Although the iron is an essential element for the physiological functions of cells, tissues and organs, it is also an important inductor of reactive oxygen species (ROS). MATERIAL AND METHODS: Three groups of human spleen with autoimmune thrombocytopenia (AITP), hereditary spherocytosis (HS) and reference samples stained by haematoxylin and eosin, Perls' reaction for nonheme Fe(III) iron and Alcian blue for glycoconjugates detection were studied. RESULTS: Positive Perls' reaction in both AITP and HS groups was seen. Higher positivity in the HS than in AITP group was observed. HS group showed a higher amount of acidic glycoconjugates deposits than AITP group. Iron overload in HS and AITP leads to overproduction of ROS. CONCLUSION: We suggest that acidic glycoconjugates deposits are involved in antioxidant defence by elimination and restriction of iron as a ROS inducer (Fig. 4, Ref. 19).

Influence of vitamin C on alcohol binding to phospholipid monolayers.

The simple model of the biological membrane is provided by well-controlled lipid monolayers at the air-water interface. The Maxwell displacement current technique (MDC) provides novel approach to conformation study of the membrane models. The effect of alcohols is interaction with membrane molecules, mainly with the lipid head group and consequent changes in physical-chemical properties of the membrane. The aim of study is to detect changes in structural, electrical and mechanical properties of dipalmitoyl-phosphatidylcholine (DPPC) monolayer on the subphase of methanol-water and ethanol-water mixtures before and after addition of antioxidant agent, vitamin C. Monolayers properties are investigated by a surface pressure analysis (including mechanical properties evaluation) and the Maxwell displacement current measurement, the dipole moment projection calculation. Surface pressure-area isotherms show similar behaviour of the DPPC monolayer on alcohol-water mixtures independently on presence of vitamin C. Binding/adsorption process induces change of electron density distribution across monolayer and thus the molecular dipole moment. We observe small or negligible binding of methanol molecules on oxygen bonds of DPPC. Thus the antioxidant, vitamin C, has no significant effect. For ethanol-water mixtures is observed recovery of electrical properties in presence of antioxidant agent. We suppose that vitamin C regulates DPPC-ethanol molecules interaction.

Conformation study of the membrane models by the Maxwell displacement current technique and oxidative stress.

The role of biological membranes as a target in biological radiation damage is still unclear. Recently much attention has been paid to the dynamic behaviour of the cell membrane. Maxwell displacement current technique (MDC) provides new possibility of conformation study of the membrane models. Oxidative stress can impair macromolecules in the cell on a molecular level. MDC technique enables to study the changes in molecular orientations and/or conformations of cell membranes. The combination of different methods in structural biology can clarify membrane chemical and physical properties.

[Detection of silicon in a human spleen using x-ray microanalysis]. / Identifikácia kremíka v l'udskej slezine röntgenovou mikroanalýzou.

There is a lack of information on x-ray microanalysis (XMA) of the human spleen. We have examined the spleen of a patient with autoimmune thrombocytopenic purpura. The specimens were fixed in glutaraldehyde and coated by copper. The XMA was performed by a Quantum detector and a Delta-Class analyzer. In addition to spectral lines of elements normally present in human tissues, we have demonstrated silicon. The presence of silicon in human spleen may be a consequence of the organ's cleansing function.