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Participation of Serotonergic System in Function of Mammalian Circadian Clock
Magdalena ONISZK, Gra¿yna BARBACKA-SUROWIAK
Summary: Serotonin plays an important role in function of the organism as a regulator of physiological and behavioral processes. Serotonin participates in the control of the biological clock located in suprachiasmatic nuclei (SCN) of the hypothalamus. Serotonergic innervation arises from the midbrain median raphe nuclei and interacts with other two main projections to the SCN. The basic role of serotonin is to modulate function of the biological clock by attenuation of the photic information transmitted to the SCN. This modulation through the activation of 5HT1A, 5HT1B and 5HT7 receptors is important for the entrainment of the clock to the environmental illumination. Serotonin and 5HT agonists are capable to phase-shift the SCN neuronal activity rhythm. Serotonin is also implicated in altering the function of the clock by non-photic stimuli.
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Key words: serotonin, circadian rhythms, SCN, photic stimuli, non-photic stimuli.
ANNA GRZELAK, WIRGINIA JANISZOWSKA
Triterpenoids Occurrance and their Biosynthesis in
Cultures in Vitro
Summary: Triterpenoids belong to the large group of plant substances, which occur commonly in plants. Considering their valuable properties (insecticidal, fungicidal, antiviral and other), active biosynthesis of triterpenoids in plant cells in vitro enjoys now growing interest. In this review the cases of production of phytoekdysteroids, steroidal and pentacyclic sapogenins by plant cells, in different type of in vitro cultures are described. In general, the amounts of phytoekdysteroids were fewer in undifferentiated cells (callus cultures) in comparison to original plants, despite several exceptions (i. e. callus tissue from Pteridium aquilinum prothalium). To digitoxin biosynthetic pathway being active in cells, the organogenesis was required. Otherwise, other steroidal sapogenis – diosgenin derivatives – are synthesised more intensively in callus tissues. Similarly, very different results were obtained in pentacyclic sapogenins biosynthesis in vitro according to plant species, culture type, medium, hormone and nutrients concentration.
Key words: triterpenoids, phytoekdysteroids, sapogenins, in vitro culture.
[Postepy Biologii Komorki 2003; 30: 229–242]
Katarzyna Dorota RACZYÑSKA, Halina AUGUSTYNIAK
The Influence of the 3’ end Processing
of Plant Mitochondrial Transcript on their Stability
Summary: Plant primary mitochondrial transcripts undergo several post-transcriptional processes like splicing, editing and 3’/5’ ends processing before become mature RNAs. In other words, the post-transcriptional processes leading to mature RNA molecules are regulated by factors which exert stabilizing or degradating effect on RNA. The steady state level of mitochondrial RNAs is determined primarily by the transcription rate, which is influenced by the promoter structure and the gene copy number. It is suggested that the factor stabilizing mitochondrial transcripts is an RNA stem loop structure, encoded by inverted repeats present in the 3’ untranslated region of many genes. In turn, the attachment of poly(A) tails to the 3’end of mitochondrial transcripts enhances their degradation by accelerating nuclease action. Mitochondrial RNAs do not display conservative sequence elementsclosely connected with polyadenylation. This article focuses on the influence of the 3’end processing of plant mitochondrial RNA on their stability and degradation
Key words:plant mitochondrial transcripts, polyadenylation, inverted repeats.
Maria S±siadek, Kamila Schlade-Bartusiak, Agnieszka Stembalska-Koz³owska, Aleksandra Bielawska-Pohl, Robert ¦migiel, Danuta Du¶
Genetic Instability in Cancer. I. Chromosomal Instability in Cancer.
Summary: Chromosomal and/or microsatellite genetic instability is one of characteristic features of malignant cells. In solid tumours, as well as in haematological tumours, chromosomal instability is expressed by accumulation of structural and numerical aberrations. Chromosomal aberrations can play a key role in cancer initiation and progression, or can be a feature of genetic instability that cells acquire during tumour development. In this review a role of chromosomal instability in overall genetic instability of cancer cells is presented.
Key words: genetic instability, chromosomal aberrations, aneuploidy, cancer.
[Postepy Biologii Komorki 2003; 30:259 –272]
Ma³gorzata KRZY¯OWSKA, Marek NIEMIA£TOWSKI
Supression of Apoptosis in Chordopoxvirus Infections
Summary: General characteristics of proteins encoded by some of the members of Chordopoxvirinae (orthopoxviruses, leporipoxviruses and molluscipoxviruses) involved in apoptosis supression has been described in this paper. Proteins involved in poxvirus modulation of apoptosis include: caspase inhibitors – serpins, soluble cytokine (IL-1a, IL-1b, IL-18, IFN-b, IFN-g, TNF-a, TNF-b) and chemokine (CC) receptors, PKR inhibitors, v-FLIPs and anti-apoptotic proteins of different functions: M11L, MT4 i p28. Due to apoptosis modyfying genes poxviruses are very well adapted to their hosts and can successfully replicate their genom.
Key words: chordopoxviruses, apoptosis, caspases, death receptors, cytokines, chemokines.
El¿bieta CIARA, Ewa POPOWSKA, Ma³gorzata KRAJEWSKA-WALASEK
Smith, Lemli, Opitz Syndrome in Clinical, Biochemical And Molecular Studies
Summary: Smith-Lemli-Opitz syndrome (SLOS, MIM 270400) is an autosomal recessive disorder, characterized by facial dysmorphisms, mental retardation and multiple congenital anomalies. Biochemically, the disorder is caused by deficient activity of 7-dehydrocholesterol reductase (DHCR7). Cholesterol plays an important role in early embryonic development probably via the function of specific gene products, such as sonic hedgehog (SHH) signaling proteins. The frequency of SLOS is calculatedto be 1:60000 to 1:10000. The 7-dehydrocholesterol reductase gene (D7 sterol reductase gene, DHCR7) was identified on chromosome 11 in region q13. Up to now 93 different mutations. and have been described in the translated exons 3–9. The mutations are mostly nucleotide substitutions (90%). Insertions and deletions are not so frequent (10%) and were identified in the nine families. The clinical severity scores were correlated with mutation classes. The mildest clinical SLOS phenotypes (SLOS type I) were associated with missense mutations and the severe phenotypes (SLOS type II) were associated with splice site and nonsense mutations as well as missense mutations located in the C-terminal domain (CT).
Key words: Smith-Lemli-Opitz syndrome, 7-dehydrocholesterol reductase, DHCR7 gene, sonic hedgehog proteins.
[Postepy Biologii Komorki 2003; 30: 293–310]
Joanna RESZEÆ, Mariola SULKOWSKA, Katarzyna GUZIÑSKA-USTYMOWICZ, Renata ZALEWSKA, Stanis³aw SULKOWSKI
Human Papillomavirus And Apoptosis
Summary: The importance of human papillomavirus infection on apoptosis and cancerogenesis was a subject of many investigations and it is still evaluated. The aim of the reviev is to present recent knowledge concerning the influence of human papillomavirus on chosen aspects of cell live and death processes. Apoptosis is a quite complex process leading to cell’s death, in which a main role play the proteins of BCL-2 family and cell cycle regulating proteins such as P53 and pRB. The meaning of HPVinfection is associated with surviving process promotion during inactivation of many proteins: P53, pRB, p107, and interaction of viral oncoproteins with cell cycle cyclines, degradation of proapoptotic proteins (BAX, BAK) what in consequence leads to overexpression of antiapoptotic proteins such Bcl-2 proteins. Basing on recent data we described the influence of viral oncoproteins on many cell cycle regulating proteins, proliferation and apoptosis regulating factors (P53, Bcl-2, BAK, BAX, pRB). A particular attention is put on the role, which play viral genes E6 and E7 products in braking apoptosis processes. The course of viral infection seem to play a significant role in cascade of apoptosis processes damage, what may leads to uncontrolled cells proliferation and neoplastic changes development.
Key words: apoptosis, HPV, BAK, BAX, Bcl-2, P53, pRb
Beata OLAS, Barbara WACHOWICZ
Role of Reactive Oxygen Species in Blood Platelets
Summary:Reactive oxygen species (ROS), which include the superoxide anion (O2-), the hydroxyl radical (·OH), hydrogen peroxide (H2O2), singlet oxygen (1O2) and nitric oxide (NO·) are highly reactive substances. They can react with lipids, proteins and DNA, inducing irreversible changes of their biomolecular structure. Several studies have shown that blood platelets, in analogy to other circulating blood cells, can produce ROS, which are involved in the mechanisms of platelet activation. In blood platelets ROS may derive from different sources. Potential sources of reactive oxygen species in blood platelets stimulated by different physiological agonists (thrombin, collagen) are associated with arachidonic acid metabolism (via cyclooxygenase or 12-lipoxygenase), phosphoinositides and glutathione cycle. ROS are also generated in platelets by activation of NADPH oxidase, xanthine oxidase and NO· synthase. Reactive oxygen species may behave as second messengers in thrombin- or collagen-activated platelets. This review presents the role of ROS in blood platelets.
Keywords: reactive oxygen species, blood platelets, glutathione.
[Postepy Biologii Komorki 2003; 30: 325–338]
Anita WI¦NIEWSKA, Marcin FILIPECKI
Gene Silencing as a Strategy for Analysis of Gene Function in Plants
Summary: One of the strategies for identification of gene function is the comparative morphological, cytological and molecular analysis of phenotypes obtained after introduction of the gene construct causing gene silencing or its overexpression. This paper describes some aspects of the gene silencing (transcriptional gene silencing, posttranscriptional gene silencing, co-suppression, homology dependent gene silencing, RNA interference, quelling), its application as a strategy for analysis of gene function and also the examples of plant silencing vectors.
Key words: gene silencing, posttranscriptional gene silencing (PTGS), RNA silencing, silencing vectors.
Irena SZUMIEL
Genome Surveillance System
Summary: Genome surveillance system and progression through the cell cycle. Upon examination of cell cycle regulation relations were discovered of the cell cycle control mechanisms with a complicated web of signaling pathways, eventually called the genome surveillance system. 2 Cellular response toDNA damage. Protein components in the surveillance system that respond to DNA damage can be divided as follows: PIKL kinases (phosphatidyl inositol 3-kinase like); trimer-forming proteins similar to PCNA (proliferating cell nuclear antigen); sensor proteins (9-1-1 complex); serine-treonine (effector) kinases (Chk 1 and Chk 2); adaptor proteins. DNA damage generates an alarm signal through PIKL kinases and sensor proteins. The signal is amplified and transduced to recruit DNA repair systems and to activate transcription of genes necessary for blocking priogression through the cell cycle, for DNA repair or apoptosis. 3. Cell cycle checkpoints . Signalling essential for blocking progression through G1, S and G2 phases starts at the Atm kinase; its downstream substrates are effector kinases, acting in all 3 checkpoints, Tp53, acting as transcription factor essential for G1/S block, nibrine (S phase checkpoint) and Brca1(checkpoints S and G2). The two latter proteins also participate in DNA repair. 4.Concluding remarks. Upon examination, the picture of the genome surveillance system becomes more and more complex. The functions best characterised in mammalian cells – control of cell cycle progression and its coordination with DNA repair - have been recently completed by new functions, mostly due to analysis of the same functions in yeast.
Key words:.genome surveillance system; Atm kinase; Tp53; Brca1; nibrine; cell cycle
[Postepy Biologii Komorki 2003; 30: 359–374]
Rafa³ Kurzawa, Andrzej Starczewski, Tomasz B±czkowski
Embryo Implantation
Summary: The paper presents comprehensively process of implantation with its stages of apposition, adhesion and invasion. Both endocrine and paracrine regulatory networks are also presented. The described phenomena are complicated and strictly controlled, thus any disorders in reproductive homeostasis in woman are connected with restriction in fertility. Pathology of apposition may lead to ectopic pregnancy or placenta praevia, early abortions are linked to disorders of adhesion, and finally pathology of invasion may cause improper placentation like placenta acreta or may predispose to pregnancy induced hypertension with its complications.
Key words: embryo, implantation
Beata JASTRZÊBSKA , Anna FILIPEK
Function of Calcium Binding Proteins of the S100 Family
Summary: Calcium ions and calcium binding proteins are involved in many cellular processes. Among the calcium binding proteins containing “EF-hand” motifs one can distinguish a group of proteins called S100 family. The majority of S100 proteins were discovered during the last ten years and, at present, this family contains 20 proteins. S100 proteins have similar primary structure since they possess 30-60% identity in amino acid sequences. Individual S100 proteins exhibit cell and tissue specific expression and their function has not been fully explained. However, the involvement of S100 proteins in many processes such as phosphorylation, enzyme activity, adhesion, survival and regeneration of neurons or apoptosis of neuronal cells, indicates, that S100 proteins might play an important intracellular and extracellular role.
Key words: calcium binding proteins, S100 proteins, function
[Postepy Biologii Komorki 2003; 30: 382–398]
Dominik CZAPLICKI
Phage-Displayed Peptide Libraries an Application in Cancer Research
Summary: The problem of molecules interaction based on the spatial structure is central to many fields of biology. Methods of building libraries that contain vast numbers of different molecules offer new approach in ligand-oriented research. One of these methods is phage display technology using libraries of peptides displayed on filamentous phage particles. Among many applications of the technique, structural peptide mimicry seems to be particularly important, since it opens a possibility for cancer immunotherapy to utilise peptide epitopes instead of glycolipid ones. The search for peptide sequences that mimic GD2 ganglioside present on neuroblastoma cancer cells comes as an example of this strategy.
Key words:peptide libraries, phage display, mimeotopes, cancer immunotherapy
Joanna PERA
Brain Tolerance to Ischemia
Summary: The possibility to induce tolerance to brain ischemia by different stimuli draws attention of many researchers. The perspective to make the brain, even transiently, more resistant to reduced blood flow seems to be very attractive considering its potentially clinical application. Molecular mechanisms of preconditioning are known only fragmentary, so far. The present work summarizes the current knowledge about factors involved in the induction of brain ischemic tolerance.
Key words: brain, preconditioning, tolerance
Henryka D£UGOÑSKA, Bo¿ena DZIADEK, Katarzyna DZITKO
An Iron Uptake by Parasitic Protozoa: Receptors for Iron-Binding Proteins
Summary: An effective iron uptake by parasitic protozoa is a determining factor for their survival in host. The available iron source, for which the parasite must compete with the macroorganism, depends on the niche where it resides and its life mode (intracellular or/and extracellular). In the paper an iron acquisition from chelate compounds (transferrin, lactoferrin) in selected protozoan species has been presented. A particular interest has been focused on flagellated protozoon, Trypanosoma brucei. In concluding remarks any particular problems associated with the studies on iron metabolism in intracellular parasitic protozoa and a significant variety of protozoan receptors involved in iron delivery, depending on a parasite species and form, have been pointed out.
Key words:iron-binding proteins, receptors, parasitic protozoa
Barbara WOLSKA-MITASZKO, Eliza MOLESTAK
Trehalose Metabolism in Plants
Summary: Plant genes encoding metabolism of trehalose were discovered not so long ago. There are more and more of dates indicating on regulatory function of trehalose and trehalase in sugar sensing and signaling as well as in the control of assimilate allocation. Nevertheless the function of trehalose metabolism in plants is still not clear.
Key words:trehalose metabolism, TPS and TPP genes, trehalase, TPS1, Tre-6P
Zuzanna GAJ, Anna LIPIÑSKA
Proteins Regulating the Cell Adhesion Mechanism in Thyroid Neoplasms
Summary: Now, it is known that aberrant cell adhesion is one of the main mechanism involved in tumor progression. Formation of metastases in majority of thyroid carcinomas evidenced the disturbance in this process. In this review, the proteins playing role in regulation of cell adhesion in thyroid neoplasms are described.
Key words: thyroid tumors, cadherins, catenins, integrins, glycoprotein CD44, dysadherin
Ma³gorzata RICHTER, Bogus³aw MACHALIÑSKI
Induction of Immunological Tolerance in Vascularized Organ Transplantation
Summary: Achieving immunological tolerance is an important goal in the effort to reduce long-term morbidity and mortality in organ transplant recipients. The establishment of mixed chimerism through the transplantation of donor bone marrow cells is an experimental approach for tolerance induction with clinical potential. Permanent, robust donor-specific tolerance has been reliably achieved in various animals models of mixed chimerism. This article reviews the historical background and the progress achieved in recent years in developing mixed chimerism protocols in rodents, large animals and also regards the issue of clinical applications.
Key words: allograft, haematopoietic stem cells, mixed chimerism, immunological tolerance, organ transplantation
Adam JAWORSKI, Liliana SERWECIÑSKA, Pawe³ ST¡CZEK
Quorum Sensing – Bacterial Cell - to - Cell Communication Using Chemical Signal Molecules
Summary: Due to the great genetic and physiological variability bacteria are able to colonize different ecological niches and rapidly adapt to the changing environmental conditions. Bacterial quorum sensing system (QS) represents one of the important mechanisms allowing bacterial cells to regulate physiological activities on the global, highly synchronized level. This system is defined as a method of intra- and interspecies communication of bacterial cells. Significant advances in the analyses of quorum sensing components show that most if not all bacterial species have developed specialized pathways for synthesis of diffusible signal molecules and receptor proteins serving as specific receptors for such signals, as well as systems for transmission of the signals onto efector proteins and, ultimately, target genes. Global regulation using QS system regulates many basic activities of bacteria such: symbiosis, virulence, competence, conjugation, antibiotics production, sporulation, biofilms formation, swarming. In Gram-negative bacteria, acyl homoserine lactones act as signal molecules, whereas in Gram-positive bacteria this role is played by oligopeptides. There are hypotheses that QS system in presently living bacteria represents early stages of multicellular organisms evolution.
Key words: quorum sensing, signal molecules, gene expression
Zbigniew KMIEÆ, Magdalena WYRZYKOWSKA
Ghrelin – Regulation of Feeding, Growth Hormone Release and Other Actions of a New Hormone
Summary: Ghrelin, an acetylated peptide composed of 28 amino-acids, is an endogenous ligand for the growth hormone secretagogues receptor, GHS-R. Ghrelin is mainly produced by the X/A cells of the oxyntic glands in the stomach and, to a much lesser extent, in hypothalamus, pituitary, adrenal gland, intestine, gonads, heart, T lymphocytes, and monocytes. Ghrelin increases growth hormone secretion independently on and synergistically with somatoliberin. It is the only peripheral hormone that increases appetite and food intake by stimulating hypothalamic neurons that secrete key orexinogens, neuropeptide Y and AgRP, and by inhibiting anorexigenic ?-MSH neurons. Serum level of ghrelin increases during fasting and becomes suppressed by refeeding and in obesity. Ghrelin increases secretory activity and motility of stomach and ileum, induces proliferation of some cell lines and shows gastro- and cardioprotective properties.
Keywords: ghrelin, feeding regulation, GH secretion, energy homeostasis
[Postepy Biologii Komorki 2005; 32: 257–272]
Ma³gorzata ROKICKA, Tigran TOROSIAN
Minimal Residual Disease Assessment in Multiple Myeloma Patients. Part I. Flow Cythometry Method
Summary: Introducing of the new methods of treatment of MM patients is connected with necessity of searching for more sophisticated methods of MRD evaluation and earlier diagnosis and treatment of relapse. The most often used methods are the fenotyping with flow cytometry and different types of qualitative and quantitative PCR. The merits and drawbacks of different method MRD evaluation are described.
Key words: multiple myeloma, minimal residual disease, flow cytometry
[Postepy Biologii Komorki 2005; 32:273–28]
Ma³gorzata ROKICKA, Tigran TOROSIAN
Minimal Residual Disease Assessment in Multiple Myeloma Patients. Part II. Molecular Markers Analysis
Summary: Introducing of the new methods of treatment of MM patients is connected with necessity of searching for more sophisticated methods of MRD evaluation and earlier diagnosis and treatment of relapse. The most often used methods are the fenotyping with flow cytometry and different types of qualitative and quantitative PCR. The merits and drawbacks of different method MRD evaluation are described.
Key words: Multiple myeloma, minimal residual disease, PCR, real time PCR
Urszula WOJEWÓDZKA, Barbara GAJKOWSKA, Jerzy JURKIEWICZ, Robert GNIADECKI
Lipid Microdomain (Lipid Rafts) in Cell Membrane: Structure, Physiology and its Role in Pathological Processes
Summary: The classical bilayer model of cell membrane structure proposed by Singer and Nicholson in 1972 has recently been modified. Research has shown that lipid molecules in the membrane do not have a random horizontal distribution but form submicroscopic domain enriched in cholesterol, sphingolipids and gangliosides. These lipid microdomain (also named lipid rafts) have been visualised in living cells by a variety of methods including fluorescence microscopy with lipid-specific probes, scanning probe microscopy and cryoelectron microscopy. Rafts can be purified by ultracentrification and flotation techniques. Lipid rafts play a key functional role in cell metabolism by means of their association with a variety of important membrane molecules, including cytokine and growth factor receptors, death receptors or non-receptor protein kinases. In this paper we briefly review the role of lipid rafts in cell homeostasis and their pathogenic significance in infection diseases, cancer, chronic inflammation, diabetes and degenerative disorders of the central nervous system.
Key words: lipid rafts, cholesterol, gangliosides, plasma membrane, growth factor receptors
[Postepy Biologii Komorki 2005; 32: 293–309] Arleta MA£ECKA, Barbara TOMASZEWSKA
Reactive Oxygen Species in Plant Cells and Antioxidative Defense Systems
Summary: All organisms are exposed to reactive oxygen species such as hydrogen peroxide (H2O2), superoxide anion (O2·-) and hydroxyl radical (·OH) as unavoidable products of oxidative metabolism. Many biotic and abiotic factors such as: pathogens, air pollutants, salts, xenobiotic, heavy metals, UV radiation initiate ROS formation. The main sites of ROS formation in plant cells are chloroplasts, peroxisomes and mitochondria. ROS can cause wide-ranging damage to many macromolecules including proteins, lipids and nucleic acids, eventually leading to cell death. Recently considered positive biological roles of ROS act as signal-transducting molecules. To minimize the damaging effects of ROS, aerobic organisms evolved several antioxidant defense mechanisms, including catalase, superoxide dismutase, peroxidases and alternative oxidase, and non-enzymatic molecules such as: ascorbic, glutathione, homoglutathione, cysteine.
Key words:reactive oxygen species, oxidative stress, antioxidant enzymes
[Postepy Biologii Komorki 2005; 32: 311–325]
Maciej MA£ECKI, Sylwia RZOÑCA
Induction of Apoptosis as a Target of Cancer Gene Therapy
Summary: Cell death, commonly recognized as necrosis or apoptosis, is thought to be a one of biological processes describing cell life. The phenomena of cell recycling during human life is known for a various types of cells and the resistance of cancer cells to apoptosis is also well described. Proapoptotic gene therapy is one of the method of cancer therapy. The main rationales are focused on induction of apoptosis of cancer cells and therefore inhibition its growth. Mostly, gene therapy trials are concerned on genes encoding well known proteins of apoptotic signaling as BAX, P53, TNF, caspases. Proapoptotic gene therapy is also discussed as a supplementary method of the cancer treatment. The classical therapies like chemiotherapy or radiotherapy may be assisted by gene transfer strategy.
Key words:gene therapy, apoptosis, cancer
[Postepy Biologii Komorki 2005; 32: 327–341]
Joanna SOLECKA, Agata ADAMCZYK, Joanna Benigna STROSZNAJDER
Alpha-Synuclein in Physiology and Pathology
Summary: Synucleins are a family of small (15–20 kDa), soluble, conserved proteins that are predominantly expressed in neurons and include a-, b-, c-Synuclein and Synoretine. Among the synuclein family exclusively a-Synuclein is the precursor protein for highly hydrophobic 35-amino acid peptide NAC (non-amyloid b component of Alzheimer’s disease plaques). This presynaptic protein associated with synaptic vesicles is also present in cytosol. Under physiological conditions a-Synuclein is natively unfolded. Cellular function of this protein is till know poorly understood, however, several lines of evidence suggest its potential role in regulation of synaptic function, neuronal plasticity, as well as cell survival. Physiological functions of this protein are disturbed by its aggregation. Posttranslational modification, oxidative stress or catabolism defects can promote its aggregation and deposition in cells in the form of Lewy bodies. Aggregated form of a-Synuclein could be involved in cell death in several neurodegenerative disorders, including Parkinson’s disease, subtype of Alzheimer’s disease with Lewy bodies, as well as in dementia with Lewy bodies. The understanding of processes responsible for a-Synuclein aggregation and NAC liberation is very important for the elucidation of pathomechanism of several neurodegenerative diseases and their effective therapy.
Key words:a-Synuclein, aggregation, neurodegeneration, brain
[Postepy Biologii Komorki 2005; 32: 343–357]
Agnieszka MARCZAK
Reactive Oxygen Species in Plant Cells and Antioxidative Defense Systems
Summary: Until very recently, erythrocytes have been considered unable to undergo apoptosis, as they lack mitochondria and nuclei, key organelles in the apoptotic machinery of other cells. However, in most recent observations it does not seem to be the truth.The major spinning point in this research was finding caspases (cysteine proteases), that play the major role in programmed cell death, in humans mature erythrocytes. This article shows the progress of apoptosis in different stadia of humans erythrocytes developement as well as in several pathological stadia. With regard to the evolutionary aspect the programmed cell death in erythrocytes of amphibians, reptiles, birds and mammals was also discussed.
Key words:apoptosis, erythrocytes, anucleated cells
[Postepy Biologii Komorki 2005; 32: 359–373]
Magdalena STOLAREK, Andrzej MY¦LIWSKI
Stem Cells of Cord Bloods
Summary: Cord blood is alternative source of the haematopoietic stem cells (HSC) in relation to bone marrow and peripheral blood. Advantage of the cord blood (CB) is its relative accessibility as a source of HSC. HSC of CB present bigger proliferative potential than HSC of bone marrow and peripheral blood. Moreover they evoke weaker GvH reaction. The disadvantage of CB is its small amount obtainable once for all. It can be applied to allogenic transplantation only, although, the banking of CB is becoming popular as a source of HSC for future autologous transplantation. However, it is not proved that HSC after many years of banking will be as good for transplantation as freshly obtained. Quite a number of publications suggest that CB can be a source of stem cells other than haematopoietic, such as: neurogenic, cardiomyogenic, mezechymal, hepatogenic and precursors of Langerhans islets of pancreas. Yet, not all accept the results of those investigations.
Key words:cord blood, haematopoietic stem cells, transplantation
[Postepy Biologii Komorki 2005; 32: 375–390]
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