Impact of acute and subchronic inhalation exposure to PbO nanoparticles on mice.

Lead nanoparticles (NPs) are released into air from metal processing, road transport or combustion processes. Inhalation exposure is therefore very likely to occur. However, even though the effects of bulk lead are well known, there is limited knowledge regarding impact of Pb NPs inhalation.

Impact of acute and chronic inhalation exposure to CdO nanoparticles on mice.

Cadmium nanoparticles can represent a risk in both industrial and environmental settings, but there is little knowledge on the impacts of their inhalation, especially concerning longer-term exposures. In this study, mice were exposed to cadmium oxide (CdO) nanoparticles in whole body inhalation chambers for 4 to 72 h in acute and 1 to 13 weeks (24 h/day, 7 days/week) in chronic exposure to investigate the dynamics of nanoparticle uptake and effects. In the acute experiment, mice were exposed to 2.

Novel PAX9 gene polymorphisms and mutations and susceptibility to tooth agenesis in the Czech population.

Objectives: Tooth agenesis is one of the most common developmental anomalies in humans. Genetic and environmental factors may be of etiological importance in this condition. Among genes involved in tooth morphogenesis, mutations in PAX9, MSX1, AXIN2, WNT10a, and EDA genes have been associated with tooth agenesis.

A screen of a large Czech cohort of oligodontia patients implicates a novel mutation in the PAX9 gene.

Tooth agenesis is one of the most common developmental anomalies in humans. To date, many mutations involving paired box 9 (PAX9), msh homeobox 1 (MSX1), and axin 2 (AXIN2) genes have been identified. The aim of the present study was to perform screening for mutations and/or polymorphisms using the capillary sequencing method in the critical regions of PAX9 and MSX1 genes in a group of 270 individuals with tooth agenesis and in 30 healthy subjects of Czech origin.

Simultaneous determination of reduced and oxidized glutathione in tissues by a novel liquid chromatography-mass spectrometry method: application in an inhalation study of Cd nanoparticles.

The paper presents the development of an advanced extraction and fast analytical LC MS/MS method for simultaneous analyses of reduced and oxidized glutathione (GSH and GSSG, respectively) in different animal tissues. The simultaneous determination of GSH and GSSG is crucial because the amount and ratio of both GSH and GSSG may be altered in response to oxidative stress, an important mechanism of toxicity. The method uses the derivatization of free thiol groups in GSH.

Interactive effect of MTHFR and ADRA2A gene polymorphisms on pathogenesis of schizophrenia.

Objectives: Increasing evidences support the importance of epigenetic control in schizophrenia pathogenesis. One of the enzymes involved in DNA methylation process through homocysteine metabolism is methylenetetrahydrofolate reductase (MTHFR). The most extensively studied variant in the MTHFR gene is the C677T polymorphism, resulting in reduced enzyme activity and elevated homocysteine level.

Expression, function and regulation of Evi-1 during embryonic avian development.

Ecotropical viral integration site 1 (Evi-1) is a transcription factor essential for vascularisation and cell proliferation during embryonic development. The chimeric transcription factor AML1-EVI-1 is activated in leukaemia where it plays a role as a differentiation block and stimulator of proliferation. Here, we cloned chicken Evi-1 and analysed its expression during embryonic development.

Molecular mechanisms of neuropathological changes in Alzheimer's disease: a review.

More than 100 years after description of Alzheimer's disease (AD), two major pathological processes observed already by Alois Alzheimer, remain as the main explanation of the pathogenesis of Alzheimer's disease. Important molecular interactions leading to AD neuropathology were described in amyloid cascade and in tau protein function. No clinical trials with novel therapies based on amyloid cascade and tau protein hypotheses have been successful.

Investigation of an autologous blood treatment strategy for temporomandibular joint hypermobility in a pig model.

Many different surgical and non-surgical techniques are used for the treatment of temporomandibular joint (TMJ) hypermobility. One of these methods is autologous blood injection into the TMJ. The fate of the autologous blood used for treatment of recurring condylar dislocation is still not completely understood.

Comparative morphology of normal and cleft minipigs demonstrates dual origin of incisors.

Objective: The incisors of the mammalian dental arch develop from tissues arising from separated facial prominences. These primordial craniofacial structures undergo complex morphogenetic processes as they merge and fuse in a time and space dependent fashion. However, local contributions of precursor facial prominences to the incisors that develop subsequently remain unknown.

Morphogenesis and bone integration of the mouse mandibular third molar.

The mouse third molar (M3) develops postnatally and is thus a unique model for studying the integration of a non-mineralized tooth with mineralized bone. This study assessed the morphogenesis of the mouse M3, related to the alveolar bone, comparing M3 development with that of the first molar (M1), the most common model in odontogenesis. The mandibular M3 was evaluated from initiation to eruption by morphology and by assessing patterns of proliferation, apoptosis, osteoclast distribution, and gene expression.

Formation of the tooth-bone interface.

Not only are teeth essential for mastication, but also missing teeth are considered a social handicap due to speech and aesthetic problems, with a resulting high impact on emotional well-being. Several treatment procedures are currently available for tooth replacement with mostly inert prosthetic materials and implants. Natural tooth substitution based on copying the developmental process of tooth formation is particularly challenging and creates a rapidly developing area of molecular dentistry.

Bendiocarbamate toxicity in the chick embryo.

Carbamate pesticides generally possess low toxicity for warm-blooded vertebrates, but developmental data are scarce. We have therefore evaluated embryotoxicity of choline esterase inhibitor bendiocarbamate in the chick embryo. The pesticide was dissolved in 5% acetone in distilled water and a volume of 200 microl was administered over the embryo through membrana papyracea on embryonic days 2, 3, 4, 5, and 10.

Primary enamel knot cell death in Apaf-1 and caspase-9 deficient mice.

During molar development, apoptosis occurs in a well-characterised pattern suggesting several roles for cell death in odontogenesis. However, molecular mechanisms of dental apoptosis are only poorly understood. In this study, Apaf-1 and caspase-9 knockouts were used to uncover the engagement of these members of the apoptotic machinery during early tooth development, concentrating primarily on their function in the apoptotic elimination of primary enamel knot cells.

CD 95 mediated apoptosis in embryogenesis: implication in tooth development.

Introduction: Understanding of apoptotic mechanisms involved in tissue shaping is of particular interest because of possible targeted modulation of the development of organ structures such as teeth. Research of CD 95 mediated apoptosis has been focused particularly on cell death in the immune system and related disorders. However, CD 95 mediated apoptosis is also involved in embryogenesis of many organs as the kidney, the lung, the intestine and tissue networks such as the nervous system.

Molar tooth development in caspase-3 deficient mice.

Tooth morphogenesis is accompanied by apoptotic events which show restricted temporospatial patterns suggesting multiple roles in odontogenesis. Dental apoptosis seems to be caspase dependent and caspase-3 has been shown to be activated during dental apoptosis.Caspase-3 mutant mice on different genetic backgrounds were used to investigate alterations in dental apoptosis and molar tooth morphogenesis.

Proliferation and apoptosis in early molar morphogenesis-- voles as models in odontogenesis.

Proliferation and apoptosis play crucial roles in the development of multicellular organisms. Their precise balance is necessary for tissue homeostasis throughout life. The developing dentition is a suitable model to study proliferation and apoptosis during embryogenesis, but the corresponding studies have been carried out principally in the mouse.

Caspase 3 activation in the primary enamel knot of developing molar tooth.

Mammalian teeth develop during embryogenesis as epithelio-mesenchymal organs. The primary enamel knot is considered as a signaling center in tooth morphogenesis. After tooth bell formation, this epithelial structure undergoes apoptosis.

Origin and developmental fate of vestigial tooth primordia in the upper diastema of the field vole (Microtus agrestis, Rodentia).

Objective: Odontogenesis in voles is a convenient model to test hypotheses on tooth development generated from investigations in the mouse. Similar to other rodents, the functional dentition of the vole includes a toothless diastema. At its mesial end, a vestigial tooth bud has been found in the upper jaw of vole embryos.

Apoptosis-related factors (Fas receptor, Fas ligand, FADD) in early tooth development of the field vole (Microtus agrestis).

Fas (CD95/APO-1) belongs to the TNF receptor (TNFR) family. Fas ligand binding followed by Fas-receptor oligomerisation leads to formation of a death-inducing signal complex starting with recruitment of the Fas-adapter protein (FADD). Components of this initiation complex (Fas, Fas-L, FADD) were correlated with apoptotic cells, detected by specific DNA fragmentation and morphological criteria.

Apoptosis distribution in the first molar tooth germ of the field vole (Microtus agrestis).

Apoptosis represents an important process in organ and tissue morphogenesis and remodeling during embryonic development. A role for apoptosis in shape formation of developing teeth has been suggested. The field vole is a useful model for comparative studies in odontogenesis, particularly because of its contrasting molar morphogenesis when compared to the mouse.