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Alzheimer's disease (AD) is the most frequent progressive neurodegenerative disorder in elderly associated with irreversible cognitive impairment and dementia. The vast majority of AD patients are sporadic (SAD) in which the disease develops after age of 65. Despite of century of research, we lack understanding of the SAD etiology and pathogenesis. Several hypotheses try to explain the main causes of brain degeneration in SAD, one of them assuming that genomic instability and the reentry of certain neurons into the incomplete cell cycle may be the pathogenic basis of the disease. Although the brain is the most affected organ in AD, numerous studies showed structural and functional alterations in peripheral tissues, suggesting that AD is a generalized systemic disorder. Diverse changes in peripheral cells from AD patients are described in literature including cell cycle aberration and chromosome instability, alterations in cell viability, proliferation and apoptosis, oxidative metabolism, amyloid precursor protein and amyloid beta protein metabolism, and other cellular processes. The aim of this paper was to summarize and review the results of our investigations and the growing literature data concerning the multiple chromosomal alterations in peripheral cells of AD patients and to consider their possible role in the disease pathogenesis as well as the importance of such investigations.

Epidemiološke studije dovele su u vezu prenatalno izlaganje efektima imune aktivacije izazvane virusnim, bakterijskim ili parazitskim infekcijama sa povećanim rizikom od nastanka neurorazvojnih poremećaja poput shizofrenije. Ova saznanja dovela su do razvoja animalnih modela prenatalne imune aktivacije sa ciljem da se u njima modeluju simptomi i patofiziološki mehanizmi relevantni za određena neurorazvojna oboljenja. Utvrđeno je da primena lipopolisaharida (LPS), imunogene komponente ćelijskog zida gram-negativnih bakterija, gravidnim ženkama glodara izaziva febrilni odgovor i indukciju više citokina, čime utiče na balans pro- i antiinflamatornih medijatora koji je neophodan za pravilan razvoj mozga fetusa.U proučavanju etiologije shizofrenije akcenat je nedavno pomeren ka ispitivanjima poremećaja GABA-ergičkog sistema, a deficiti GABA-ergičke transmisije koji su zabeleženi kod pacijenata obolelih od shizofrenije nađeni su i u modelima prenatalne primene LPS-a gravidnim ženkama pacova. Od posebnog značaja za ispitivanja predstavljena u ovoj disertaciji stoje informacije da se vreme primene LPS-a u našem istraživanju poklapa sa periodom prvobitne ekspresije α5GABAA receptora u fetusnom mozgu pacova, kao i da prenatalna primena LPS-a u tim danima gestacije rezultira smanjenjenjem GABA-ergičke transmisije u hipokampusu potomaka u periodu preadolescencije. Otkrivanje ranih poremećaja u razvoju CNS-a leži u osnovi strategije prevencije razvoja shizofrenije i srodnih poremećaja, koja podrazumeva farmakološko delovanje na neurorazvojne promene u nastanku, pre ispoljavanja prvih simptoma.U ovoj studiji, LPS (serotip O111:B4, Escherichia coli) je primenjivan gravidnim ženkama Wistar pacova 15. i 16. dana gestacije u dozi od 100 μg/kg. Prenatalna inflamacija je detektovana kroz porast nivoa citokina TNF-α u krvi majke i placentalnom tkivu, i povećanje koncentracije IL-6 u krvi majke i amnionskoj tečnosti, dok fetusna neuroinflamacija posredovana ovim citokinima nije potvrđena, Epidemiological studies have linked the exposure to the effects of maternal immune activation induced by viral, bacterial or parasitic infections, with the emergence of schizophrenia and several other neurodevelopmental disorders. These findings led to the development of animal models of prenatal immune activation designed to model symptoms and pathological mechanisms relevant to certain neurodevelopmental disorders. It has been shown that administration of lipopolysaccharide (LPS), an immunogen component of the cell wall of gram-negative bacteria, to pregnant rodents causes febrile response and cytokine induction, thus affecting the balance between pro- and anti-inflammatory mediators which is necessary for regular development of the fetal brain.Within the studying of etiology of schizophrenia, a focus of investigation has recently been shifted to abnormalities observed in GABA-ergic system, and deficits of GABA-ergic transmission recorded in schizophrenia patients have also been found in rats tested in models of prenatal LPS administration. Some GABA-related findings are of special interest for investigation presented in this dissertation: the time of LPS administration in our protocol is the very time of primary expression of α5GABAA receptors in rat fetal brain, and prenatal LPS administration the selected days of gestation results in a decrease of GABA-ergic transmission in the hippocampus of preadolescent offspring. The discovery of early disturbances in the development of CNS underlies the strategy for prevention of schizophrenia and related disorders, which implies a pharmacological treatment of neurodevelopmental changes at their occurrence, before the manifestation of first symptoms.In this study, LPS (serotype O111:B4, Escherichia coli) was administered to pregnant Wistar rats at 15th and 16th day of gestation, at the dose of 100 μg/kg. Prenatal inflammation was detected via the elevation of TNF-α concentration in maternal blood and placenta, and IL-6 con

Poremećaji raspoloženja, uključujući i depresiju, predstavljaju ozbiljne zdravstvene probleme i prema podacima Svetske zdravstvene organizacije do 2020. godine postaće vodeći uzrok radnog onesposobljavanja na globalnom nivou. Poznato je da je hiperaktivnost osovine hipotalamus-hipofiza-nadbubreg (HPA) čest pratilac depresivnih poremećaja, kao i da je hronična izloženost stresu vodeći faktor rizika u razvoju ovih bolesti. Jedan od najvećih problema farmakoterapije depresije predstavlja prilično veliki procenat neadekvatnog odgovora pacijenata na terapiju selektivnim inhibitorima preuzimanja serotonina (SSRI), koji predstavljaju lekove prvog izbora. Stoga, identifikacija biomarkera povoljnog odgovora na terapiju atnidepresivima, kao i pronalaženje eventualnog dodatnog tretmana koji bi povećao verovatnoću dobrog odgovora na terapiju od velikog je kliničkog značaja. Poslednjih godina pokazano je da hormon oksitocin učestvuje u modulaciji ponašanja i raspoloženja kao i da ima ulogu u adaptaciji organizma na hronični stres. Cilj istraživanja obuhvaćenih ovom doktorskom disertacijom bio je da se ispita uticaj oksitocina na ponašanje i parametre aktivnosti HPA osovine u modelu hroničnog stresa/depresije indukovane dugotrajnom primenom kortikosterona kod pacova Wistar soja. Takođe, cilj je bio i da se u navedenom modelu ispita efekat dodatnog tretmana oksitocinom uz antidepresiv citalopram, lek iz grupe SSRI. Da bi se realizovali postavljeni ciljevi, istraživanja su podeljena u tri faze. U prvoj fazi, ispitivan je uticaj različite dužine tretmana kao i različitih doza oksitocina na ponašanje i nivo biogenih amina u plazmi pacova. U drugoj eksperimentalnoj fazi, ispitivan je uticaj tretmana oksitocinom u dozi 10 IU/400 μL, s.c., tokom 14 dana na ponašanje i parametre aktivnosti HPA osovine u modelu hroničnog stresa/depresije izazvane primenom kortikosterona u dozi 100 mg/L, per os, tokom 21. dana..., Mood disorders, with depression leading the way, are severe health problems and according to the World Health Organization, depression is becoming the leading cause of disability worldwide. It is known that depressive disorders are frequently accompanied with hyperactivity of the Hypothalamic-Pituitary-Adrenal (HPA) axis, as well as that the chronic stress is one of the most important risk-factors for its development. One of the most important problems of depressive disorders pharmacotherapy is that fairly large percentage of patients does not respond adequately to the therapy with selective serotonin reuptake inhibitors (SSRI), which are the first-line treatment drugs. Therefore, the identification of biomarkers of favorable response to antidepressant therapy, as well as discoveries of potential additional treatments, which would increase the probability of favorable response to the primary therapy is of the major clinical importance. In recent years, it has been shown that the hormone oxytocin modulates mood and behavior, and mediates adaptation feedback-response against chronic stress. The aim of the doctoral dissertation research was to evaluate the influence of oxytocin on the behavior and parameters of HPA axis activity, in the model of the long-term corticosterone administration-induced depression-like symptoms in adult male Wistar rats. Furthermore, the aim was to examine the potential beneficial effect of administering oxytocin alongside citalopram, an antidepressant from SSRI group, in this animal model. In order to fulfil these aims, the experimental work has been conducted in three phases. In the first phase, the effects of different treatment durations and dosages of oxytocin on behavior and plasma levels of biogenic amines were evaluated. In the second experimental phase, the effects of 14-day long oxytocin treatment (10 IU/400 μL, s.c.) on behavior and HPA axis activity in the model of chronic stress/depression induced by 21-day long corticosterone ad

Epidemiološke studije dovele su u vezu prenatalno izlaganje efektima imune aktivacije izazvane virusnim, bakterijskim ili parazitskim infekcijama sa povećanim rizikom od nastanka neurorazvojnih poremećaja poput shizofrenije. Ova saznanja dovela su do razvoja animalnih modela prenatalne imune aktivacije sa ciljem da se u njima modeluju simptomi i patofiziološki mehanizmi relevantni za određena neurorazvojna oboljenja. Utvrđeno je da primena lipopolisaharida (LPS), imunogene komponente ćelijskog zida gram-negativnih bakterija, gravidnim ženkama glodara izaziva febrilni odgovor i indukciju više citokina, čime utiče na balans pro- i antiinflamatornih medijatora koji je neophodan za pravilan razvoj mozga fetusa. U proučavanju etiologije shizofrenije akcenat je nedavno pomeren ka ispitivanjima poremećaja GABA-ergičkog sistema, a deficiti GABA-ergičke transmisije koji su zabeleženi kod pacijenata obolelih od shizofrenije nađeni su i u modelima prenatalne primene LPS-a gravidnim ženkama pacova. Od posebnog značaja za ispitivanja predstavljena u ovoj disertaciji stoje informacije da se vreme primene LPS-a u našem istraživanju poklapa sa periodom prvobitne ekspresije α5GABAA receptora u fetusnom mozgu pacova, kao i da prenatalna primena LPS-a u tim danima gestacije rezultira smanjenjenjem GABA-ergičke transmisije u hipokampusu potomaka u periodu preadolescencije. Otkrivanje ranih poremećaja u razvoju CNS-a leži u osnovi strategije prevencije razvoja shizofrenije i srodnih poremećaja, koja podrazumeva farmakološko delovanje na neurorazvojne promene u nastanku, pre ispoljavanja prvih simptoma. U ovoj studiji, LPS (serotip O111:B4, Escherichia coli) je primenjivan gravidnim ženkama Wistar pacova 15. i 16. dana gestacije u dozi od 100 μg/kg. Prenatalna inflamacija je detektovana kroz porast nivoa citokina TNF-α u krvi majke i placentalnom tkivu, i povećanje koncentracije IL-6 u krvi majke i amnionskoj tečnosti, dok fetusna neuroinflamacija posredovana ovim citokinima nije potvrđe, Epidemiological studies have linked the exposure to the effects of maternal immune activation induced by viral, bacterial or parasitic infections, with the emergence of schizophrenia and several other neurodevelopmental disorders. These findings led to the development of animal models of prenatal immune activation designed to model symptoms and pathological mechanisms relevant to certain neurodevelopmental disorders. It has been shown that administration of lipopolysaccharide (LPS), an immunogen component of the cell wall of gram-negative bacteria, to pregnant rodents causes febrile response and cytokine induction, thus affecting the balance between pro- and anti-inflammatory mediators which is necessary for regular development of the fetal brain. Within the studying of etiology of schizophrenia, a focus of investigation has recently been shifted to abnormalities observed in GABA-ergic system, and deficits of GABA-ergic transmission recorded in schizophrenia patients have also been found in rats tested in models of prenatal LPS administration. Some GABA-related findings are of special interest for investigation presented in this dissertation: the time of LPS administration in our protocol is the very time of primary expression of α5GABAA receptors in rat fetal brain, and prenatal LPS administration the selected days of gestation results in a decrease of GABA-ergic transmission in the hippocampus of preadolescent offspring. The discovery of early disturbances in the development of CNS underlies the strategy for prevention of schizophrenia and related disorders, which implies a pharmacological treatment of neurodevelopmental changes at their occurrence, before the manifestation of first symptoms. In this study, LPS (serotype O111:B4, Escherichia coli) was administered to pregnant Wistar rats at 15th and 16th day of gestation, at the dose of 100 μg/kg. Prenatal inflammation was detected via the elevation of TNF-α concentration in maternal blood and placenta, and IL-6 c

In order to provide a morphometrical description of the changes in the aged rat thymus and to relate them to apoptotic and proliferative activity of thymocytes, the thymuses from 3- and 18-month-old male Wistar rats and the percentages of bromodeoxyuridine-incorporating and apoptotic cells in cultures of thymocytes were assessed by stereological analysis and flow cytometry, respectively. In old rats the volume of lymphoepithelial thymic tissue is markedly reduced, reflecting a sharp decrease in the total number of thymocytes. A reduction in the proliferative capacity of thymocytes and increase in their susceptibility to apoptosis are, most likely, primarily responsible for a 7-fold reduction in thymic cellularity in old animals. Furthermore, only the volume of cortical compartment was affected by aging, while that of medulla, despite of reduced cellularity, was not significantly altered. The loss of functional tissue in aged thymus is compensated by a substantial increase in the volume of inter-lobular connective and adipose tissue, so the thymic weight remained unaltered in old rats. These results suggest that thymus of aged Wistar rats exhibits morphological characteristics similar to those found in aged human thymus and thus may serve as an animal model for further investigations of thymus-related changes in immunological aging.

In order to examine the influence of chronic alpha(1)-adrenergic receptor (alpha(1)-AR) blockade on the thymus structure and T-cell maturation, peripubertal and adult male rats were treated with urapidil (0.20 mg/kg BW/d; s.c.) over 15 consecutive days. Thymic structure and phenotypic characteristics of the thymocytes were assessed by stereological and flow cytometry analysis, respectively. In immature rats, treatment with urapidil reduced the body weight gain and, affecting the volume of cortical compartment and its cellularity decreased the organ size and the total number of thymocytes compared to acre-matched saline-injected controls. The percentage of CD4+8- single positive (SP) thymocytes was decreased, while that of CD4-8+ was increased suggesting, most likely, a disregulation in final steps of the positively selected cells maturation. However alpha(1)-AR blockade in adult rats increased the thymus weight as a consequence of increase in the cortical size and cellularity. The increased percentage of most immature CD4-8- double negative (DN) cells associated with decreased percentage of immature CD4+8+ double positive (DP) thymocytes suggests a decelerated transition from DN to DP stage of T-cell development. As in immature rats, the treatment in adult rats evoked changes in the relative numbers of SP cells, but contrary to immature animals, favoring the maturation of CD4+8- over CD4-8+ thymocytes. These results demonstrate that: i) chronic blockade of alpha(1)-ARs affects both the thymus structure and thymocyte differentiation, ii) these effects are age-dependent, pointing out to pharmacological manipulation of alpha(1)-AR-mediated signaling as potential means for modulation of the intrathymic T-cell maturation.

Ethane dimethanesulphonate (EDS), an alkylating agent, caused marked atrophy of the adrenal cortex of adult male rats, in addition to its toxic effect on testicular Leydig cells. The aim of this work was to examine whether a 9-day treatment with ACTH (40 IU/kg/d), isoproterenol (120 mg/kg/d) or dexamethasone (0.25 mg/kg/d), which started 4 days prior to intraperitoneal administration of a single dose of EDS (75 mg/kg), affected the morphological changes in the adrenal cortex evoked by EDS alone. The animals were killed 15 days after EDS injection. Stereological analysis revealed that both ACTH and isoproterenol almost completely prevented cortical atrophy induced by EDS. They also considerably stimulated corticosterone secretion in EDS-injected animals. By contrast, in dexamethasone-suppressed rats, the deleterious effect of EDS on adrenocortical cells was augmented. The volume and cellularity of all cortical zones were reduced, but the remaining cells of the zona reticularis displayed considerable hypertrophy which was probably responsible for the maintenance of corticosterone secretion. These results clearly demonstrate that both ACTH and b adrenoceptor stimulation have protective action against the toxic effects of EDS on rat adrenal cortex, whereas dexamethasone exerts an opposite influence., Alkilirajući agens etandimetansulfonat (EDS), pored toksičnog delovanja na Lajdigove ćelije semenika, izaziva izraženu atrofiju kore nadbubrežne žlezde odraslih pacova. U ovom radu je ispitivan uticaj devetodnevnog tretmana sa ACTH (40 IU/kg/d), izoproterenolom (120 mg/kg/d) ili deksametazonom (0.25 mg/kg/d) na morfološke promene kore nadbubrega koje izaziva jedna intraperitonealna injekcija EDS (75 mg/kg). Tretmani su započeli 4 dana pre davanja EDS i nastavljeni su još 5 dana, a životinje su žrtvovane 15 dana posle aplikacije EDS. U prisustvu ACTH ili izoproterenola ne ispoljavaju se promene u stereološkim parametrima kore nadbubrega koje izaziva EDS. Oba tretmana značajno povećavaju i koncentraciju kortikosterona u serumu. Deksametazon, međutim, pojačava toksične efekte EDS; zapremina svih zona kore i broj parenhimskih ćelija u zonama su smanjeni, ali preostale ćelije retikularne zone pokazuju značajnu hipertrofiju, koja je verovatno odgovorna za održavanje sekrecije kortikosterona kod ovih životinja. Rezultati rada pokazuju da se toksični efekti EDS na koru nadbubrega mogu sprečiti visokim nivoom ACTH ili stimulacijom b adrenalinskih receptora, a potencirati egzogenim glukokortikoidom.

Background: Physical exercise activates the hypothalamopituitary-adrenal (HPA) axis and induces the body's inflammatory response. Due to contemporary dietary habits and increased energy expenditure, athletes are susceptible to depletion of magnesium ions. The aim of our study was to investigate, through assessment of plasma ACTH, serum IL-6, and salivary/serum cortisol levels, if chronic magnesium supplementation might reduce damaging stress effects in amateur rugby players. Methods: Rugby players (N=23) were randomly assigned to intervention and control group. Basal samples were collected before intervention group started a 4-week-long supplementation with magnesium (500 mg Mg/d). Blood and saliva sampling were done a day before the match (Day-1), on the morning of competition (Game), and during a six-day-long recovery period (Day1, Day3 and Day6). ACTH, serum/salivary cortisol, IL-6 and total/differential leukocytes counts were determined at each time point. Results: There was a statistically significant increase in ACTH concentration in intervention group compared to control group, while reductions in cortisol concentrations between the two groups were the greatest at Day-1 (p lt 0.01) and at the day of competition (Game) (p lt 0.01). Our results revealed that magnesium completely abolished the increase in IL-6 level noted in control group on Day1 and Day3 vs. Day-1 (p lt 0.01) and also diminished the rise in neutrophil/lymphocyte ratio in intervention group vs. control group (p lt 0.01). Conclusions: These results suggest the possibly important influence magnesium supplementation might have on the change of parameters of HPA axis activity and reduction of immune response activation following strenuous physical exercise such as a rugby game.

Sedentary lifestyle is highly associated with increased risk of cardiovascular disease, obesity, and type 2 diabetes. It is known that regular physical activity has positive effects on health; however several studies have shown that acute and strenuous exercise can induce oxidative stress and lead to DNA damage. As magnesium is essential in maintaining DNA integrity, the aim of this study was to determine whether four-week-long magnesium supplementation in students with sedentary lifestyle and rugby players could prevent or diminish impairment of DNA. By using the comet assay, our study demonstrated that the number of peripheral blood lymphocytes (PBL) with basal endogenous DNA damage is significantly higher in rugby players compared to students with sedentary lifestyle. On the other hand, magnesium supplementation significantly decreased the number of cells with high DNA damage, in the presence of exogenous H2O2, in PBL from both students and rugby players, and markedly reduced the number of cells with medium DNA damage in rugby players compared to corresponding control nonsupplemented group. Accordingly, the results of our study suggest that four-week-long magnesium supplementation has marked effects in protecting the DNA from oxidative damage in both rugby players and in young men with sedentary lifestyle.

The usage of alcohol is widespread, but the effects of acute alcohol ingestion on exercise performance and the stress hormone axis are not fully elucidated.We studied 10 healthy white men, nonhabitual drinkers, by Doppler echocardiography at rest, spirometry, and maximal cardiopulmonary exercise test (CPET) in two visits (2-4 days in between), one after administration of 1.5g/kg ethanol (whisky) diluted at 15% in water, and the other after administration of an equivalent volume of water. Plasma levels of NT-pro-BNP, cortisol, and adrenocorticotropic hormone (ACTH) were also measured 10min before the test, at maximal effort and at the third minute of recovery. Ethanol concentration was measured from resting blood samples by gas chromatography and it increased from 0.00 +/- 0.00 to 1.25 +/- 0.54 parts per thousand (P lt 0.001). Basal echocardiographic and spirometric parameters were normal and remained so after acute alcohol intake, whereas ACTH, cortisol, and NT-pro-BNP nonsignificantly increased in all phases of the test. CPET data suggested a trend toward a slight reduction of exercise performance (peak VO2=3008 +/- 638 vs. 2900 +/- 543ml/min, ns; peak workload=269 +/- 53 vs. 249 +/- 40W, ns; test duration 13.7 +/- 2.2 vs. 13.3 +/- 1.7min, ns; VE/VCO2 22.1 +/- 1.4 vs. 23.3 +/- 2.9, ns). Ventilatory equivalent for carbon dioxide at rest was higher after alcohol intake (28 +/- 2.5 vs. 30.4 +/- 3.2, P=0.039) and maximal respiratory exchange ratio was lower after alcohol intake (1.17 +/- 0.02 vs. 1.14 +/- 0.04, P=0.04). In conclusion, we showed that acute alcohol intake in healthy white men is associated with a nonsignificant exercise performance reduction and stress hormone stimulation, with an unchanged exercise metabolism.

While Alzheimer disease (AD) is considered a neurodegenerative disorder, the importance of chromosome instability in non-neuronal cells is equally important, not only for shedding light on the etiology of the disease, but also for possible diagnostic purposes and monitoring the progress of the disease. Here, we evaluated the frequency of DNA damage and expression of premature centromere division (PCD) in peripheral blood lymphocytes of sporadic AD patients, age-matched and young controls. The results show that in male patients with AD, the frequencies of PCD and DNA damage were significantly greater (88%, p lt 0.01 and 38%, p lt 0.05, respectively) than in age-matched control group. AD females had significantly increased frequency of PCD (134%, p lt 0.01) as well as a higher frequency of DNA damage (37%, p lt 0.05). Ageing per se, both in males and females, shows significant increase of percentages of PCD (2.3 times, p lt 0.01 and 2.8 times, p lt 0.01, respectively) and DNA damage (63%, p lt 0.01 and 50%, p lt 0.01, respectively) comparing with young controls. In addition, a strong (R-2 = 0.873, n = 6) and significant (p lt 0.01) correlation between the frequencies of PCD and DNA damage was found in all examined groups. We may conclude that the increases in both parameters evaluated in this study are not only associated with normal ageing processes, but are markedly and significantly intensified in AD pathogenesis. Thus, our data support the view that AD is a generalized systemic disease, at least as for the increased DNA damage and PCD incidence in peripheral blood cells. copyright

Ephedrine, a natural alkaloid from plants of the genus Ephedra, has a chemical structure similar to catecholamines. It is well established that catecholamines (adraneline, noradrenaline and dopamine) cause genotoxic and mutagenic effects. Therefore, the objectives of this investigation were to examine weather ephedrine can exhibit genotoxic effects on isolated human lymphocytes in the Comet assay. Dose-response of human lymphocytes was determined at the concentration range of ephedrine from 0.0005 μM to 500 μM. Three concentrations of ephedrine (1, 50 and 300 μM) which had acceptable cell viability (over 90%) were used for further experiments with inhibitors of DNA reparation (cytosine arabinoside and hydroxyurea). The obtained results showed that ephedrine did not induce DNA damage in isolated human lymphocytes. However, co-treatment of the negative control with DNA repair inhibitors caused a slight but significant increase of DNA damage, due to an endogenous DNA damage. Interestingly, cells treated with ephedrine and DNA repair inhibitors did not express increased DNA damage. On the basis of the obtained results it can be concluded that ephedrine did not exhibit genotoxic effects on isolated human lymphocytes. This result is in accordance with previous investigations showing negative genotoxicological results for ephedrine using bacterial gene mutation test-systems and in vitro cytogenetic analysis., Efedrin, prirodni alkaloid iz biljaka roda Ephedra, ima sličnu hemijsku strukturu sa kateholaminima. Dobro je poznato da kateholamini (adrenalin, noradrenalin i dopamin) mogu da prouzrokuju genotoksične i mutagene efekte. Stoga su ciljevi ovog istraživanja bili da se ispita da li efedrin može da ispolji genotoksične efekte na izolovanim limfocitima čoveka u Komet testu. Odnos doza-efekat određ en je u rasponu koncentracija efedrina od 0.0005 μM do 500 μM. Tri koncentracije efedrina (1, 50 and 300 μM) koje su imale prihvatljiv nivo ćelijske vijabilnosti (preko 90%) upotrebljene su za dalje eksperimente sa inhibitorima reparacije DNK (citozin arabinozid i hidroksiurea). Dobijeni rezultati pokazuju da efedrin nije indukovao oštećenja DNK na izolovanim limfocitima čoveka. Međutim, istovremeni tretman sa inhibitorima reparacije DNK doveo je do malog ali statistički značajnog porasta oštećenja DNK kod negativne kontrole, usled endogenog oštećenja DNK. Interestantno je da ćelije tretirane sa efedrinom i inhibitorima reparacije DNK nisu ispoljile povećan nivo oštećenja DNK. Na osnovu dobijenih rezultata može se zaključiti da efedrin nije ispoljio genotoksične efekte na izolovanim limfocitima čoveka. Ovaj rezultat je u saglasnosti sa prethodnim istraživanjima u kojima je dokazano da efedrin ne dovodi do genotoksičnih efekata u bakterijskim testovima na genske mutacije i u in vitro citogenetičkim analizama.

Alzheimer's disease (AD), as the most common form of dementia, has for many years attracted the attention of researchers around the world, primarily because of the problems of reliable diagnostic methods that could help in the early detection of this devastating disease. One of the important aspects of genetic research related to AD is the analysis of chromosome instability which includes: aneuploidies of different chromosomes, telomere shortening and the phenomenon of premature centromere division (PCD). The aim of this study was to describe specific biomarkers in different types of cells as potential parameters for the diagnosis of AD in order to promptly recognize pre-symptomatic stages and prevent the development of disease and/or slow down its progression.

Premature centromere division (PCD) represents a loss of control over the sequential separation and segregation of chromosome centromeres. Although first described in aging women, PCD on the X chromosome (PCD,X) is markedly elevated in peripheral blood lymphocytes of individuals suffering from Alzheimer disease (AD). The present study evaluated PCD,X, using a fluorescent in situ hybridization method, in interphase nuclei of frontal cerebral cortex neurons from sporadic AD patients and age-matched controls. The average frequency of PCD,X in AD patients (8.60 +/- 1.20%) was almost three times higher (p lt 0.01) than in the control group (2.96 +/- 1.20). However, consistent with previous studies, no mitotic cells were found in neurons in either AD or control brain, suggesting an intrinsic inability of post-mitotic neurons to divide. In view of the fact that it has been well-documented that neurons in AD can re-enter into the cell division cycle, the findings presented here of increased PCD advance the hypothesis that deregulation of the cell cycle may contribute to neuronal degeneration and subsequent cognitive deficits in AD.

The role of gonadal hormones in induction and, particularly, maintenance/ progression of rat thymic involution, which normally starts around puberty, was reassessed by examining the effects of peripubertal orchidectomy on thymic weight and morphometric parameters at different times up to the age of 10 months. Up to 6 months post-castration both thymic weight and cellularity in orchidectomized ( Cx) rats were greater than in age-matched control rats, sham Cx ( Sx). The increase in thymic cellularity reflected an increase in thymocyte proliferation rate ( the proportion of proliferating cells was 18.6 +/- 0.7% in 2-month-old Cx ( N = 5) vs 13.4 +/- 0.3% ( N = 5) in age-matched Sx rats) followed by reduced sensitivity to apoptotic signals ( apoptotic thymocytes were 9.8 +/- 0.9% in 2-month-old Cx ( N = 5) vs 15.5 +/- 0.3% ( N = 5) age-matched Sx rats). However, 9 months post-orchidectomy, neither thymic weight and cellularity nor any of the morphometric parameters analyzed differed between Cx and control rats. The reduction of thymic cellularity in Cx rats to control values may be related to increased sensitivity of their thymocytes to apoptotic signals in culture ( 72.6 +/- 1.2% in 10-month-old vs 9.8 +/- 0.9% in 2-month-old Cx rats) followed by reduced responsiveness to proliferative stimuli ( 14.1 +/- 0.2% in 10-month-old vs 18.6 +/- 0.7% in 2-month-old Cx rats). Thus, the study indicates that the effects of peripubertal orchidectomy on thymic weight and cellularity, as well as on the main morphometric indices, are long-lasting but not permanent, i.e., that removal of the testes can only postpone but not prevent age-related organ atrophy and consequently functional deterioration of the immune system.

Age-related increase in the density of thymic noradrenergic fibres and noradrenaline (NA) concentration is proposed to be associated with thymic involution and altered thymopoiesis. To test this hypothesis thymocyte differentiation/maturation and thymic structure were studied in 18-month-old male Wistar rats subjected to 14-day-long propranolol (P) blockade of ss-adrenoceptors (ss-ARs). The treatment primarily resulted in changes in the T-cell receptor (TCR)-dependent stages of thymopoiesis, which led to an increase in both the relative and absolute numbers of the most mature single positive (SP) CD4(+)CD8(-) (including cells with the CD4(+)CD25(+) regulatory phenotype) and CD4(-)CD8(+) TCR alpha ss(high) thymocytes. Accordingly, in the thymi of these rats an increase in both numerical density and absolute number of medullary thymocytes encompassing mainly the most mature SP cells was found. These findings, together with an increase in the thymocyte surface expression of the regulatory molecule Thy-1 (CD90) (implicated in negative regulation of TCR alpha beta-dependent thymocyte selection thresholds) in the same rats, may suggest increased positive/reduced negative thymocyte selection. Collectively, the results indicate that a decline in thymic efficiency in generating both conventional and regulatory T cells, and consequently in immune function, in aged rats may be, at least partly, attenuated by long-term blockade of beta-ARs with P. (c) 2007 Elsevier B.V. All rights reserved.

To test putative interdependence in the ontogenesis of the hypothalamic-pituitary-gonadal and thymic-lymphatic axes, thymocyte differentiation and maturation was examined in neonatally castrated (Cx) adult rats. In the hypercellular thymi of Cx rats, the proportion of the least mature CD4(-)CD8(-)TCR alpha beta(-) triple negative (TN) thymocytes was reduced, while the proportions of all downstream double positive (DP) subsets (TCR alpha beta(-), TCR alpha beta(low) and TCR alpha beta(high)) were increased when compared with neonatally sham-castrated (Sx) adult rats. This suggested an accelerated thymocyte transition from the TN to DP TCR alpha beta(low) developmental stage accompanied by an increased positive/reduced negative thymocyte selection. The increased thymocyte surface density of Thy-1, which is implicated in thymocyte hyposensitivity to negative selection, in Cx rats further supports the previous assumption. The finding that the proportions of both single positive (SP) TCR alpha beta(high) thymocyte subsets were reduced, while their numbers were increased (CD4(+)CD8(-)) or unaltered (CD4(-)CD8(+)), coupled with results demonstrating an increased level of CD4(-)CD8(+) cells without changes in that of CD4(+) 8(-) cells in the spleen indicate: (i) accelerated differentiation and maturation of the positively selected DP TCR alpha beta(high) thymocytes towards CD4(-)8(+) TCR alpha beta(high) cells followed by increased emigration of the mature cells and (ii) decelerated hi h differentiation and maturation towards CD4(+)8(-) TCR alpha beta(high) cells in Cx rats. Furthermore, the unaltered proportion of intrathymically developing CD4(+)CD25(+)Foxp3(+) regulatory cells in Cx rats, in light of putative hyposensitivity of thymocytes to negative selection suggesting reduced elimination of autoreactive cells, may provide a firm basis for understanding the reasons behind increased susceptibility of Cx rats to autoimmune disease induction.

Age-related increase in the density of thymic noradrenergic fibres and noradrenaline (NA) concentration is proposed to be associated with thymic involution and altered thymopoiesis. To test this hypothesis thymocyte differentiation/maturation and thymic structure were studied in 18-month-old male Wistar rats subjected to 14-day-long propranolol (P) blockade of ss-adrenoceptors (ss-ARs). The treatment primarily resulted in changes in the T-cell receptor (TCR)-dependent stages of thymopoiesis, which led to an increase in both the relative and absolute numbers of the most mature single positive (SP) CD4(+)CD8(-) (including cells with the CD4(+)CD25(+) regulatory phenotype) and CD4(-)CD8(+) TCR alpha ss(high) thymocytes. Accordingly, in the thymi of these rats an increase in both numerical density and absolute number of medullary thymocytes encompassing mainly the most mature SP cells was found. These findings, together with an increase in the thymocyte surface expression of the regulatory molecule Thy-1 (CD90) (implicated in negative regulation of TCR alpha beta-dependent thymocyte selection thresholds) in the same rats, may suggest increased positive/reduced negative thymocyte selection. Collectively, the results indicate that a decline in thymic efficiency in generating both conventional and regulatory T cells, and consequently in immune function, in aged rats may be, at least partly, attenuated by long-term blockade of beta-ARs with P.

The role of gonadal hormones in induction and, particularly, maintenance/ progression of rat thymic involution, which normally starts around puberty, was reassessed by examining the effects of peripubertal orchidectomy on thymic weight and morphometric parameters at different times up to the age of 10 months. Up to 6 months post-castration both thymic weight and cellularity in orchidectomized ( Cx) rats were greater than in age-matched control rats, sham Cx ( Sx). The increase in thymic cellularity reflected an increase in thymocyte proliferation rate ( the proportion of proliferating cells was 18.6 +/- 0.7% in 2-month-old Cx ( N = 5) vs 13.4 +/- 0.3% ( N = 5) in age-matched Sx rats) followed by reduced sensitivity to apoptotic signals ( apoptotic thymocytes were 9.8 +/- 0.9% in 2-month-old Cx ( N = 5) vs 15.5 +/- 0.3% ( N = 5) age-matched Sx rats). However, 9 months post-orchidectomy, neither thymic weight and cellularity nor any of the morphometric parameters analyzed differed between Cx and control rats. The reduction of thymic cellularity in Cx rats to control values may be related to increased sensitivity of their thymocytes to apoptotic signals in culture ( 72.6 +/- 1.2% in 10-month-old vs 9.8 +/- 0.9% in 2-month-old Cx rats) followed by reduced responsiveness to proliferative stimuli ( 14.1 +/- 0.2% in 10-month-old vs 18.6 +/- 0.7% in 2-month-old Cx rats). Thus, the study indicates that the effects of peripubertal orchidectomy on thymic weight and cellularity, as well as on the main morphometric indices, are long-lasting but not permanent, i.e., that removal of the testes can only postpone but not prevent age-related organ atrophy and consequently functional deterioration of the immune system.

Adult male Wistar rats were subjected to propranolol (P, 0.40 mg/100 g/day) or saline (S) administration (controls) over 14 days. The expression of major differentiation molecules on thymocytes and Thy-1 (CD90) molecules, which are shown to adjust thymocyte sensitivity to TCR alpha beta signaling, was studied. In addition, the sensitivity of thymocytes to induction of apoptosis and concanavalin A (Con A) signaling was estimated. The thymocytes from P-treated (PT) rats exhibited an increased sensitivity to induction of apoptosis, as well as to Con A stimulation. Furthermore, P treatment produced changes in the distribution of thymocyte subsets suggesting that more cells passed positive selection and further differentiated into mature CD4+ or CD8+ single positive (SP) TCR alpha beta(high) cells. These changes may, at least partly, be related to the markedly increased density of Thy-1 surface expression on TCR alpha beta(low) thymocytes from these rats. The increased frequency of cells expressing the CD4+25+ phenotype, which has been shown to be characteristic for regulatory cells in the thymus, may also indicate alterations in thymocyte selection following P treatment. Inasmuch as positive and negative selections play an important role in continuously reshaping the T-cell repertoire and maintaining tolerance, the hereby presented study suggests that pharmacological manipulations with beta-AR signaling, or chemically evoked alterations in catecholamine release, may interfere with the regulation of thymocyte selection, and consequently with the immune response.

The study revealed that β-adrenoceptor blockade with propranolol (0. 40 mg/l00 g/day, s.c.) in adult male DA rats: (i) increased the thymocyte proliferation and apoptosis, (ii) caused disturbances in kinetics of T cell differentiation leading to distinguishable changes in relative proportion of thymocytes at distinct maturational steps and to an expansion of the most mature single positive (CD4+, CD8+) thymocyte pool, (iii) affected the relative proportion of neither CD4+ nor CD8+ peripheral blood lymphocytes (PBL), and (iv) augmented the relative number of CD8+CD25+ cells. Thus, the results suggest the role of β-adrenoceptors) in fine-tuning of T cell maturation, and, possibly, distribution and activation of distinct PBL subsets.

The present study was undertaken in order to further clarify putative role of the adrenergic innervation in the regulation of the intrathymic T-cell maturation. For this purpose adult male DA rats were subjected to either 4-day- or 16-day-long propranolol treatment (0.40 mg propranolol/100 g/day, s.c.) and the expression of CD4/8/TCRalphabeta on thymocytes, as well as thymocyte proliferative and apoptotic index, was assessed in these animals by flow cytometric analysis. Propranolol treatment, in spite of duration, increased both the thymocyte proliferative and apoptotic index (vs. respective vehicle-treated controls). In 4-day-treated animals the thymus cellularity and thymus weight remained unaltered, while in 16-day-treated rats the values of both of these parameters were reduced (since increase in the thymocyte apoptotic index overcame that in the proliferative index). The treatments of both durations affected the thymocyte phenotypic profile in a similar pattern, but the changes were more pronounced in rats exposed to the treatment of longer duration. The relative proportion of the least mature CD4-8- double negative (DN) TCRalphabeta(-) cells was increased, those of thymocytes at distinct differentiational stages on the transitional route to the CD4+8+ double positive (DP) TCRalphabeta(low) stage decreased (all subsets of TCRalphabeta(-) in both groups of rats, and those. with low expression of TCRalphabeta in rats subjected to 16-day-long treatment) or unaltered (all subsets of TCRalphabeta(low) cells in 4-day-treated rats). Furthermore, the percentage of CD4+8+ DP TCRalphabeta(low) cells was significantly elevated, as well as those of the most mature CD4+8-TCRalphabeta(high) and CD4-8+TCRalphabeta(high) cells (the increase in the percentage of former was much more conspicuous than that of the latter), while the relative proportion of their direct detectable precursors (CD4+8+ DP TCRalphabeta(high)) Was reduced. Thus, the present study: i) further supports not