Subacute intratracheal exposure of rats to manganese nanoparticles: Behavioral, electrophysiological, and general toxicological effects

The toxicity of manganese-containing airborne particles is an important occupational and environmental problem. In this work, adult male Wistar rats were treated with a nanosuspension of MnO2 of approximately 23nm nominal particle diameter, instilled into the trachea for 3, 6, and 9wk in doses of 2.63 and 5.26mg Mn/kg. The animals' body weight was checked weekly. At the end of treatment, the rats' spontaneous motility was tested in an open field box. Then, spontaneous and stimulus-evoked cortical activity and action potential of the tail nerve were recorded in urethane anesthesia. The rats were finally dissected, organs weights were measured, and the presence of excess Mn in lung and brain samples was determined using scanning electron microscopy with energy-dispersive x-ray spectroscopy. While control rats had normal weight gain, the body weights of the treated rats ceased to grow fürom wk 6 on. The relative weight of the lungs increased in the treated rats, and that of the liver decreased, in a dose- and time-dependent manner; Mn was detected in their lung and brain samples. In the open field activity, the percentage of ambulation and rearing decreased while local activity and immobility increased. The latency of the evoked potentials was lengthened, and the conduction velocity of the tail nerve decreased. These results indicate that the Mn content of instilled nanoparticles had access fürom the airways to the brain, and the resulting damage could be investigated in animals using neuro-functional and general toxicological endpoints. © 2009 Informa UK Ltd

A pathogenitásért és az állati sejtek manipulálásáért felelős, új adenovírus fehérjék keresése = Search for novel adenovirus proteins responsible for pathogenicity and the manipulation of animal cells

Az adenovírusok sejtreceptorokhoz történő kapcsolódásában részt vevő kapszidfehérjék (a pentonbázis és fiberfej) határozzák meg a vírus szöveti és sejt-specificitását. A sejtek manipulálásáért és az adenovírusok kórokozó képességéért azonban alapvetően a korai kifejeződésű gének által kódolt fehérjék felelősek. Eddig ismeretlen adenovírusokat találva főleg hüllőkben, vadmadarakban, rágcsálókban, denevérekben és majmokban, valamint vírusgenom szekvenálást és elemzést végezve (pl. teljes hal-, gyík-, liba-, egér-, denevér-, majom- és humán adenovírus genomok) számos feltehetően korai, új gén létezését sikerült kimutatni. Vizsgáltuk az ezek által kódolt fehérjék evolúcióját, sokféleségét, változékonyságát, természetes mutáció okozta rövidülését, delécióját vagy duplikációját, a sejtreceptor-kötő helyek meglétét vagy hiányát. A hal-adenovírus feltételezett szulfotranszferáz homológjának génjét és több állati adenovírusból a fiberfejet kódoló génszakaszt bakteriális kifejező rendszerbe klónoztuk és teszteltük kifejeződésüket. Következtetéseket vontunk le a vizsgált gének funkciójára, esetleges nélkülözhetőségükre, valamint az egyes vírusok között megfigyelhető pathogenitási és más biológiai különbségek okára vonatkozóan. | The capsid proteins (penton base and the fiber knob), which take part in the attachment to the cellular receptors, play crucial role in the organ and tissue tropism of adenoviruses. Nonetheless, the proteins coded by the early genes are primarily responsible for the manipulation of cells and for the pathogenicity of these viruses. By finding novel adenoviruses mainly in reptiles, wild birds, rodents, bats and monkeys, and by sequencing and analysing adenovirus genomes (e.g., the full genome of the sturgeon, lizard, goose, mouse, bat, monkey and human adenoviruses), the existence of numerous such supposedly early genes was revealed. We studied the evolution, diversity, variability, truncation caused by natural mutation, deletion, duplication of these proteins as well as the presence or lack of cellular receptor binding sites. The gene of a sulfotransferase homologue of sturgeon adenovirus and gene fragments coding the fiber knobs of several animal adenoviruses were cloned and expressed in bacterial expression systems. We drew several conclusions concerning the function, possible non-essential status of these genes, and the reason for the observed differences in the pathogenicity and other biological properties of the adenoviruses examined

Assessment of cerebral circulation in a porcine model of intravenously given E. coli induced fulminant sepsis

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“Platelet-associated regulatory system (PARS)” with particular reference to female reproduction

BACKGROUND: Blood platelets play an essential role in hemostasis, thrombosis and coagulation of blood. Beyond these classic functions their involvement in inflammatory, neoplastic and immune processes was also investigated. It is well known, that platelets have an armament of soluble molecules, factors, mediators, chemokines, cytokines and neurotransmitters in their granules, and have multiple adhesion molecules and receptors on their surface. METHODS: Selected relevant literature and own views and experiences as clinical observations have been used. RESULTS: Considering that platelets are indispensable in numerous homeostatic endocrine functions, it is reasonable to suppose that a platelet-associated regulatory system (PARS) may exist; internal or external triggers and/or stimuli may complement and connect regulatory pathways aimed towards target tissues and/or cells. The signal (PAF, or other tissue/cell specific factors) comes from the stimulated (by the e.g., hypophyseal hormones, bacteria, external factors, etc.) organs or cells, and activates platelets. Platelet activation means their aggregation, sludge formation, furthermore the release of the for-mentioned biologically very powerful factors, which can locally amplify and deepen the tissue specific cell reactions. If this process is impaired or inhibited for any reason, the specifically stimulated organ shows hypofunction. When PARS is upregulated, organ hyperfunction may occur that culminate in severe diseases. CONCLUSION: Based on clinical and experimental evidences we propose that platelets modulate the function of hypothalamo-hypophyseal-ovarian system. Specifically, hypothalamic GnRH releases FSH from the anterior pituitary, which induces and stimulates follicular and oocyte maturation and steroid hormone secretion in the ovary. At the same time follicular cells enhance PAF production. Through these pathways activated platelets are accumulated in the follicular vessels surrounding the follicle and due to its released soluble molecules (factors, mediators, chemokines, cytokines, neurotransmitters) locally increase oocyte maturation and hormone secretion. Therefore we suggest that platelets are not only a small participant but may be the conductor or active mediator of this complex regulatory system which has several unrevealed mechanisms. In other words platelets are corpuscular messengers, or are more than a member of the family providing hemostasis

Magyar Tanítóképző 17 (1902) 04

Magyar Tanítóképző A Tanítóképző-intézeti Tanárok Országos Egyesületének közlönye 17. évfolyam, 04. füzet Budapest, 1902. április h

Magyar Tanítóképző 17 (1902) 05

Magyar Tanítóképző A Tanítóképző-intézeti Tanárok Országos Egyesületének közlönye 17. évfolyam, 05. füzet Budapest, 1902. május h

Determination of valine and leucine isomers in peptaibols

Peptaibols are oligomers, containing non-proteogenic amino acids. Some of them are considered as antifungal and antibiotic agents, therefore the elucidation of their structure is important. There have been a lot of efforts determining their amino acid sequences via mass spectrometry, but isobaric components cannot be determined using this technique. In this work, a HPLC method development was carried out for the determination of leucine, isoleucine, valine and isovaline in one chromatographic run. Furthermore, a chiral separation of the optical isomers of these compounds has been also solved

A Single Early Introduction Governed Viral Diversity in the Second Wave of SARS-CoV-2 Epidemic in Hungary

Retrospective evaluation of past waves of the SARS-CoV-2 epidemic is key for designing optimal interventions against future waves and novel pandemics. Here we report on analysing genome sequences of SARS-CoV-2 from the first two waves of the epidemic in 2020 in Hungary, mirroring a suppression and a mitigation strategy, respectively. Our analysis reveals that the two waves markedly differed in viral diversity and transmission patterns. Specifically, unlike in several European areas or in the USA, we have found no evidence for early introduction and cryptic transmission of the virus in the first wave of the pandemic in Hungary. Despite the introduction of multiple viral lineages, extensive community spread was prevented by a timely national lockdown in March 2020. In sharp contrast, the majority of the cases in the much larger second wave can be linked to a single transmission lineage of the pan-European B.1.160 variant. This lineage was introduced unexpectedly early, followed by a two-month-long cryptic transmission before a soar of detected cases in September 2020. Epidemic analysis has revealed that the dominance of this lineage in the second wave was not associated with an intrinsic transmission advantage. This finding is further supported by the rapid replacement of B.1.160 by the alpha variant (B.1.1.7) that launched the third wave of the epidemic in February 2021. Overall, these results illustrate how the founder effect in combination with cryptic transmission, instead of repeated international introductions or higher transmissibility, can govern viral diversity

The response of prion genic variation to selection for scrapie resistance in Hungarian indigenous sheep breeds

The authors studied the present status of Hungarian indigenous sheep breeds based on the genetic background of scrapie resistance. The aim of this investigation was to estimate the relative frequency of prion haplotypes, genotypes and risk categories, as well as to reveal the efficiency of the scrapie eradication programme achieved over the last decade. A novel approach in the characterisation of prion by using its genic variation was also implemented. The authors established that the proportion of deleterious sites (%) can be a useful indicator of the eradication programme. Based on a large sample size, it was confirmed that the scrapie resistance of the Cikta breed is low, and the classification of this breed according to risk category has not improved. However, the frequent genotype ARQ and risk category 3 can also be considered characteristic of the breed. The careful use of these genotypes is permitted and will contribute to the maintenance of breed diversity. The response of prion genic variation to selection for scrapie resistance in the other breeds (Tsigai, Milking Tsigai, White Racka, Black Racka and Gyimes Racka) was definitely successful