T cell knockout mice have diminished alveolar bone loss after oral infection with Porphyromonas gingivalis

Periodontal diseases are chronic inflammatory diseases that can result in resorption of the alveolar bone of the jaw. We have developed a murine model in which alveolar bone loss is induced by oral infection with Porphyromonas gingivalis, an oral anaerobic bacterium associated with periodontal disease in humans. Here we compared a strain of immunocompetent mice (C57BL/6J) to the same strain of mice made T cell deficient by genetic deletion of the alpha chain of their T cell receptors (C57BL/6J-Tcra). T cell deficiency did not affect the ability of P. gingivalis to implant in the oral cavity. The two strains of mice had equal percentages of P. gingivalis among their cultivable anaerobes 7 weeks after infection. The same bacterial load led to much less bone resorption in the T cell deficient mice than in the immune normal mice, measured as either the number of sites with significant loss, or as the total amount of bone resorbed. T cell deficient mice lost bone at only three out of 14 measurement sites, compared with eight out of 14 sites in the wild-type mice. The total amount of bone lost was 70% less in the T cell deficient mice. T cell deficient mice had lower titers of P. gingivalis-specific IgG than the wild-type mice after oral infection did, but the same titers of specific IgA. Lower titers did not correlate with greater bone loss. Antigen-activated T lymphocytes are known to induce osteoclastogenesis; here we demonstrate that T cell deletion decreases the amount of alveolar bone loss induced by infection of the murine oral cavity.     

Stereochemistry at the Benzylic Centre in Hydroxyglycitylanthraquinones

Abstract

For two anthracyclinone precursors, 1,4-dihydroxy-2-(1-hydroxy-2,3:4,5-di-0-isopropylidene-D-arabinityl)-9,10-anthraquinone (1) and methyl 2,3-0-isopropylidene-5-(2-quinizarinyl)-α-D-lyxofuranoside (5) prepared by a modification of the Marschalk reaction, single-crystal X-ray analyses indicate that the configurations are both S at the new chiral centres C-1′ and C-5.     

OMG do not say LOL: obese adolescents' perspectives on the content of text messages to enhance weight loss efforts

Adolescents participating in weight loss programs experience difficulty adhering to behavior change recommendations. Communications technology provides a low cost means to increase the frequency of contact with adolescents which can improve their engagement and also lead to behavior change. Within a larger project on the development of tailored text messages for adolescents enrolled in an existing multidisciplinary weight management program, this study explored participants' perspectives about message content. A library of messages was developed focused on topics central to weight management. Four focus groups were conducted with a total of 24 participants from the weight management program to gage their reactions to the messages. Detailed notes from the focus groups were analyzed to assess the acceptability of individual messages and to identify overriding themes. Results indicate that participants were very enthusiastic about receiving text messages. They preferred messages that provided recipe ideas, included successful weight loss strategies used by peers, and requested feedback regarding their progress. They preferred positive, encouraging, and direct messages. They were unanimous that messages should include encouraging symbols (e.g., exclamation points and "smiley faces") as often as possible. They emphasized that any mention of unhealthy foods or behaviors would trigger them to eat those foods or engage in those behaviors. Text messaging acronyms (e.g., LOL) were considered too informal for messages from healthcare providers. This study suggests that including text messages in obesity interventions is acceptable to obese adolescents as a means of supporting their weight loss efforts, and it highlights the need for such messages to be carefully constructed.     

Evaluating Aesthetic Experience through Personal-Appearance Styles: A Behavioral and Electrophysiological Study

Consumers'' aesthetic experience has often been linked with the concept of beauty, which is regarded as subjective and may vary between individuals, cultures and places, and across time. With the advent of brain-imaging techniques, there is more and more evidence to suggest that aesthetic experience lies not only in the eye of the beholder, but also in the brain of the beholder. However, there are gaps in the previous research in this area, as several significant issues have not yet been addressed. Specifically, it is unclear whether the human brain really pays more attention and generates more positive emotional responses to beautiful things. To explore the brain activity relating to consumers'' aesthetic experiences, 15 participants were recruited voluntarily to view a series of personal-appearance styles. They were invited to make aesthetic judgments while their brain activity was recorded by electroencephalography. Two electroencephalographic (EEG) indicators, theta coherence and frontal alpha symmetry, were utilized. Theta coherence is a measure of linear synchronization between signals at two electrode sites. It reflects the degree of functional cooperation between the underlying neuronal substrates and was used to explore the attentional processing involved in aesthetic judgments. Frontal alpha asymmetry is derived by subtracting the log-transformed absolute alpha power of the left hemisphere from the analogous log-transformed alpha power of the right hemisphere. It was used as an indicator of emotional response. During aesthetic judgments, long-range theta coherence increased in both hemispheres and more positive frontal alpha asymmetry was found when the styles were judged to be beautiful. Therefore, participants demonstrated brain activity suggestive of central executive processing and more positive emotional responses when they considered styles to be beautiful. The study provides some insight into the brain activity associated with consumers'' aesthetic experiences, and suggests new directions for exploring consumer behavior from the perspective of neuroscience.     

RIP4 is an ankyrin repeat-containing kinase essential for keratinocyte differentiation

The epidermis is a stratified, continually renewing epithelium dependent on a balance among cell proliferation, differentiation, and death for homeostasis. In normal epidermis, a mitotically active basal layer gives rise to terminally differentiating keratinocytes that migrate outward and are ultimately sloughed from the skin surface as enucleated squames. Although many proteins are known to function in maintaining epidermal homeostasis, the molecular coordination of these events is poorly understood. RIP4 is a novel RIP (receptor-interacting protein) family kinase with ankyrin repeats cloned from a keratinocyte cDNA library. RIP4 deficiency in mice results in perinatal lethality associated with abnormal epidermal differentiation. The phenotype of RIP4(-/-) mice in part resembles that of mice lacking IKKalpha, a component of a complex that regulates NF-kappaB. Despite the similar keratinocyte defects in RIP4- and IKKalpha-deficient mice, these kinases function in distinct pathways. RIP4 functions cell autonomously within the keratinocyte lineage. Unlike IKKalpha, RIP4-deficient skin fails to fully differentiate when grafted onto a normal host. Instead, abnormal hair follicle development and epidermal dysplasia, indicative of progression into a more pathologic state, are observed. Thus, RIP4 is a critical component of a novel pathway that controls keratinocyte differentiation.