Is Aberrant DNA Methylation a Key Factor in Molar Incisor Hypomineralization?

Molar incisor hypomineralization (MIH) is a qualitative disturbance of the enamel of the permanent molars and/or incisors. Its etiology is not clearly defined but is connected with different factors occurring before and after birth. It remains difficult to identify a single factor or group of factors, and the problem is further complicated by various overlapping mechanisms. In this study, we attempted to determine whether DNA methylation—an epigenetic mechanism—plays a key role in the etiology of MIH. We collected the epithelium of the oral mucosa from children with MIH and healthy individuals and analyzed its global DNA methylation level in each child using a 5-mC DNA ELISA kit after DNA isolation. There was no statistically significant difference between the global DNA methylation levels in the study and control groups. Then, we also analyzed the associations of the DNA methylation levels with different prenatal, perinatal, and postnatal factors, using appropriate statistical methods. Factors such as number of pregnancies, number of births, type of delivery, varicella infection (under 3 years old), and high fever (under 3 years old) were significantly important. This work can be seen as the first step towards further studies of the epigenetic background of the MIH etiology.     

Genetic similarity within and among populations of the Variable and Azure damelflies (Coenagrion pulchellum and C. puella)

In the first half of this century, seven species of the damselfly genus Coenagrion regularly bred in Britain. Since that time, two of these species have become extinct, and three currently have highly restricted distributions. Of the remaining two species, the Azure Damselfly (C. puella) is both common and abundant, but the Variable Damselfly (C. pulchellum), while more common than most Coenagrion species, is experiencing a national decline in Britain. The reasons for the decline of C. pulchellum are poorly understood, and therefore its future in Britain is difficult to predict. The aim of this study was to investigate genetic relationships among populations of C. puella and C. pulchellum. We obtained mitochondrial sequence data from 36 C. puella and C. pulchellum individuals collected from five different sites across central England. These revealed three haplotypes with high overall similarity. Hybridisation between C. puella and C. pulchellum was suggested by (1) The sharing of a haplotype between C. puella and C. pulchellum, and (2) The fact that morphological characters of sympatric C. puella and C. pulchellum populations are not always species-specific. More research is required before we can determine whether or not hybridisation is playing a role in the decline of Coenagrion species in the U.K.     

The potential function of post-fledging dispersal behavior in first breeding territory selection for males of a migratory bird

One possible hypothesis for the function of post-fledging dispersal is to locate a suitable future breeding area. This post-fledging period may be particularly important in migratory species because they have a limited period to gather information prior to autumn migration, and in protandrous species, males must quickly acquire a territory after returning from spring migration to maximize their fitness. Here we use color-ring resightings to investigate how the post-fledging dispersal movements of the Cyprus wheatear Oenanthe cypriaca, a small migratory passerine, relate to their first breeding territory the following year when they return from migration. We found that males established first breeding territories that were significantly closer to their post-fledging location than to their natal sites or to post-fledging locations of other conspecifics, but these patterns were not apparent in females. Our findings suggest that familiarity with potential breeding sites may be important for juveniles of migratory species, particularly for the sex that acquires and advertises breeding territories. Exploratory dispersal prior to a migrant’s first autumn migration may contribute toward its breeding success the following year, further highlighting the importance of early seasonal breeding on fitness and population dynamics more generally.     

Anti-oxidant activity of superoxide dismutase and glutathione peroxidase enzymes in skeletal muscles from slaughter cattle infected with Taenia saginata

It is known that highly reactive oxygene species produced during normal cellular metabolism represent a powerful effector mechanism against parasites. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) belong to the main defense anti-oxidants that prevent the formation of new free radical species. The aim of this study was to assess the activities of SOD and GPx in cattle tissues infected with Taenia saginata. We observed a statistically significant increase in the SOD and GPx activities (p = 0.00003, 0.00008, respectively, Student’s t-test) in skeletal muscles infected with T. saginata in spectrophotometric analysis. With the use of western blot technique, SOD synthesis stimulation has appeared in the host tissues containing cysticerci in contrast with the control samples. There was no statistically significant increase in the GPx band intensity observed in the studied samples in comparison to controls (Gene Tools Version 4.01 program). These results support the significance of anti-oxidant processes in host defense mechanism during parasitic infections.     

Modulation of the human preadipocyte mitochondrial activity by beta-carotene

Increased ROS generation by the overload by metabolic substrates mitochondria paralleled by decrease of antioxidant activity are typical events found in metabolic syndrome and diabetes type 2. Metabolites of beta-carotene (BC) such as retinoic acid (RA), as well as low concentration of reactive oxygen species (ROS) modify the mitochondrial bioenergetic function. The aim of the study was to investigate the effect of beta-carotene on mitochondrial activity in human preadipocytes. BC used in concentrations, 10 or 30 μM, decreased mitochondrial membrane potential, inhibited mitochondrial respiration and decreased cellular ATP content. We conclude, that BC, the known antioxidant may decrease oxidative phosphorylation capacity of mitochondria.     

Evaluation of anti-human antibodies for immunohistochemistry on archival nonhuman primate tissues

Abstract: A panel of commercially available antibodies which recognize specific antigens on human tissues was developed for use in immunohistochemistry on tissues from eight species of nonhuman primates. Antibodies were selected for potential usefulness in diagnostic pathology, and for effectiveness in formalin-fixed, paraffin-embedded tissues. Tissues from four species of macaques and four New World monkeys were evaluated. Using these antibodies we were able to identify 17/21 antigens examined in all eight species, and 21/21 antigens in the four species of macaques. Detailed immunohistochemistry protocols are presented, along with a systematic approach to developing a protocol for a new antibody.