Inhalation of ZnO Nanoparticles: Splice Junction Expression and Alternative Splicing in Mice.

Despite the wide application of nanomaterials, toxicity studies of nanoparticles (NP) are often limited to in vitro cell models, and the biological impact of NP exposure in mammals has not been thoroughly investigated. Zinc oxide (ZnO) NPs are commonly used in various consumer products. To evaluate the effects of the inhalation of ZnO NP in mice, we studied splice junction expression in the lungs as a proxy to gene expression changes analysis.

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.

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.

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.

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.

Tooth-bone morphogenesis during postnatal stages of mouse first molar development.

The first mouse molar (M1) is the most common model for odontogenesis, with research particularly focused on prenatal development. However, the functional dentition forms postnatally, when the histogenesis and morphogenesis of the tooth is completed, the roots form and the tooth physically anchors into the jaw. In this work, M1 was studied from birth to eruption, assessing morphogenesis, proliferation and apoptosis, and correlating these with remodeling of the surrounding bony tissue.

Early morphogenesis of heterodont dentition in minipigs.

The minipig provides an excellent experimental model for tooth morphogenesis because its diphyodont and heterodont dentition resemble that of humans. However, little information is available on the processes of tooth development in the pig. The purpose of this study was to classify the early stages of odontogenesis in minipigs from the initiation of deciduous dentition to the late bell stage when the successional dental lamina begins to develop.

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.

Relationship between vestibular lamina, dental lamina, and the developing oral vestibule in the upper jaw of the field vole (Microtus agrestis, Rodentia).

Formation of the oral vestibule is ignored in most studies on tooth development, although dental and vestibular lamina are closely related to each other. Knowledge about morphogenetic processes shaping the oral vestibule is missing almost completely. The aim of this study was to assess the developmental relationship between dental and vestibular lamina as well as formation of the oral vestibule in the upper jaw of the field vole (Microtus agrestis), a small rodent representing an attractive model species for comparative dental studies.

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.

Heart development in the spotted dolphin (Stenella attenuata).

Marine mammals show many deviations from typical mammalian characteristics due to their high degree of specialization to the aquatic environment. In Cetaceans, some of the features of limbs and dentition resemble very ancestral patterns. In some species, hearts with a clearly bifid apex (a feature normally present during mammalian embryogenesis prior to completion of ventricular septation) have been described.

Three-dimensional reconstruction studies and morphometric analysis of rudimental tooth primordia in the upper incisor region of the sheep (Ovis aries, Ruminantia).

The functional dentition of the domestic sheep lacks all upper incisors and the upper canines. Nevertheless, occurrence of a dental lamina and rudimental tooth primordia had been described in the upper incisor region of the sheep. The aim of this study was to describe temporo-spatial pattern of origin and regression of these rudimental tooth primordia by light microscopy, computer-aided three-dimensional reconstruction and morphometry of the dental epithelium.