Intrinsic regulation of hemangioma involution by platelet-derived growth factor.

Infantile hemangioma is a vascular tumor that exhibits a unique natural cycle of rapid growth followed by involution. Previously, we have shown that hemangiomas arise from CD133+ stem cells that differentiate into endothelial cells when implanted in immunodeficient mice. The same clonally expanded stem cells also produced adipocytes, thus recapitulating the involuting phase of hemangioma. In the present study, we have elucidated the intrinsic mechanisms of adipocyte differentiation using hemangioma-derived stem cells (hemSCs). We found that platelet-derived growth factor (PDGF) is elevated during the proliferating phase and may inhibit adipocyte differentiation. hemSCs expressed high levels of PDGF-B and showed sustained tyrosine phosphorylation of PDGF receptors under basal (unstimulated) conditions. Inhibition of PDGF receptor signaling caused enhanced adipogenesis in hemSCs. Furthermore, exposure of hemSCs to exogenous PDGF-BB reduced the fat content and the expression of adipocyte-specific transcription factors. We also show that these autogenous inhibitory effects are mediated by PDGF receptor-ß signaling. In summary, this study identifies PDGF signaling as an intrinsic negative regulator of hemangioma involution and highlights the therapeutic potential of disrupting PDGF signaling for the treatment of hemangiomas.

Exploring opportunities for collaboration between the corporate sector and the dental education community.

The ultimate purpose of both dental industry and dental education is to improve the oral health of the public. This report provides background information on the different roles and objectives of the dental industry and dental education communities, the different operating environment of each sector and also areas of common interest where collaboration will be of mutual benefit. The report addresses five areas for potential collaboration between the dental industry and the dental education communities: 1. Contribution to joint activities. 2. Effectiveness and efficiency. 3. Workforce needs. 4. Middle- and low-income countries. 5. The future of International Federation of Dental Educators and Associations (IFDEA). The traditional areas of support and their limitations that have been provided by industry are outlined in the report and some new approaches for collaboration are considered. Industry-based research has been an important factor in developing new products and technologies and in promoting oral health. However there is a need to facilitate the introduction of these developments at an early stage in the education process. Industry has to operate in an efficient manner to remain competitive and maximise its returns and therefore survive. The academic sector operates in a different environment and under different governance structures; although some trends are noted towards adoption of greater efficiency and financial accountability similar to industry. Opportunities to jointly develop best business practices should be explored. Industry has responded well to the oral health needs of the public through the development of new products and technologies. The education community needs to respond in a similar way by examining different healthcare delivery models worldwide and developing programmes to train members of the dental team to cater for future needs and demands of communities in different regions of the world. The reputation of industry-based scientists and clinicians is high, and their role in contributing to the dental education process in practical ways needs to be explored and further developed. Closer relationships between industry scientists and faculty and students could assist industrys need and desire to develop new technologies for the broader dental care system. The corporate sector can play a key role in the future success of IFDEA by providing support and expertise in developing areas such as regional leadership institutes, a Global Faculty and Network and in collaborating in developing continuing education programmes as well as involvement in its governance. Thirteen recommendations are made in the report. These are considered to be important initial steps in developing the already strong relationship between the education and corporate sectors. Partnership and collaborating more effectively along the lines suggested should, almost certainly, generate mutually beneficial outcomes, whilst serving over the long term to elevate the publics oral health status on a global basis.

A microsatellite sequence from the rice blast fungus (Magnaporthe grisea) distinguishes between the centromeres of Hordeum vulgare and H. bulbosum in hybrid plants.

A TC/AG-repeat microsatellite sequence derived from the rice blast fungus (Magnaporthe grisea) hybridized to all of the centromeres of Hordeum vulgare chromosomes, but hybridized faintly or not at all to the chromosomes of Hordeum bulbosum. Using this H. vulgare centromere-specific probe, the chromosomes of four F1 hybrids between H. vulgare and H. bulbosum were analyzed. The chromosome constitution in the root tips of the hybrids was mosaic, i.e., 7 (7v, H. vulgare) and 14 (7v + 7b H. bulbosum), or 14 (7v + 7b) and 27 (14v + 13b), or 7 (7v), 14 (7v + 7b), and 27 (14v + 13b). The 27-chromosome tetraploid hybrid cells were revealed to have the NOR (nucleolus organizer region) bearing chromosome of H. bulbosum in a hemizygous state, which might indicate some role for this chromosome in the chromosome instability of the hybrid condition. The chromosomal distribution showed that the chromosomes of H. vulgare were concentric and chromosomes of H. bulbosum were peripheral in the mitotic squash. This non-random chromosome distribution and the centromere-specific repeated DNA differences in the two species were discussed in relation to H. bulbosum chromosome elimination. Meiotic chromosome analyses revealed a high frequency of homoeologous chromosome pairing in early prophase. However, this chromosome pairing did not persist until later meiotic stages and many univalents and chromosome fragments resulted. These were revealed to be H. bulbosum by fluorescence in situ hybridization (FISH) analysis with the H. vulgare centromere-specific probe. Because the chromosome segregation of H. vulgare and H. bulbosum chromosomes at anaphase I of meiosis was random, the possibility for obtaining chromosome substitution lines in diploid barley from the diploid hybrid was discussed.

Isolation of TC/AG repeat microsatellite sequences for fingerprinting rice blast fungus and their possible horizontal transfer to plant species.

Genome fingerprinting has been a major role in characterization of population structure and analysis of the variability in phytopathogenic fungi. In order to characterize Korean rice blast fungal isolates, the genomic DNAs were digested with AluI endonuclease and subsequent PCR amplifications using random decamer primers with combinations of microsatellite primers had been carried out. This Alu-Inter SSR technique revealed high polymorphism among the Korean blast fungal isolates. Then, fragments from the Alu-Inter SSR analysis were isolated to be used as probes in Southern hybridization, which also revealed high polymorphism between isolates to distinguish individuals. The sequences of the isolated fragments contained TC/AG tandem repeats interspersed with a 30 bp direct repeat. In gel blot analysis, the isolated TC/AG repeat microsatellite sequences were proved to be useful for characterizing the isolates in blast fungi in addition to the conventional MGR (Magnaporthe grisea repeat) probes. One interesting point was that the rice blast fungus derived TC/AG repeat microsatellite sequences were abundant in non-rice blast fungi and plant species, but not in other fungi and yeasts. A discussion on the possible horizontal gene transfer between phytopathogenic fungi and host plants is presented.