Cardiac Neural Crest Cells Affect the Development of the Myocardium and Conduction System in the Mouse

Neural crest cells originate from the dorsal most region of the embryonic neural tube. These cells migrate into several embryonic locations and differentiate into a variety of cell types. Cardiac neural crest (CNC) cells are a set of neural crest progenitors that aid in the proper formation of the cardiac septum, which separates the pulmonary from the systemic circulation. We have used Splotch mice to investigate whether the murine CNC cells play a role during the development oft he myocardium and the conduction system. Splotch mice carry a mutation in the P AX3 transcription factor, and display a problem in CNC cell migration. A scanning-electron-microscopy analysis of Splotch mutant-embryonic-hearts reveals abnormalities in the interventricular septum. In addition, the right and left ventricular cavities appear dilated relative to a wild type heart. Hoechst nuclei staining of Splotch heart cryosections demonstrates a decreased number of cardiomyocytes and a corresponding thinner ventricular wall. The absence of Connexin 40 in the ventricles of Splotch mutants, suggests conduction system defects. These results support the evidence that CNC cell signaling plays a role in modulating the growth and development of murine cardiomyocytes and their differentiation into conductile cells.

Database As A Tool For Hospitality Management

In his discussion - Database As A Tool For Hospitality Management - William O'Brien, Assistant Professor, School of Hospitality Management at Florida International University, O’Brien offers at the outset, “Database systems offer sweeping possibilities for better management of information in the hospitality industry. The author discusses what such systems are capable of accomplishing.” The author opens with a bit of background on database system development, which also lends an impression as to the complexion of the rest of the article; uh, it’s a shade technical. “In early 1981, Ashton-Tate introduced dBase 11. It was the first microcomputer database management processor to offer relational capabilities and a user-friendly query system combined with a fast, convenient report writer,” O’Brien informs. “When 16-bit microcomputers such as the IBM PC series were introduced late the following year, more powerful database products followed: dBase 111, Friday!, and Framework. The effect on the entire business community, and the hospitality industry in particular, has been remarkable”, he further offers with his informed outlook. Professor O’Brien offers a few anecdotal situations to illustrate how much a comprehensive data-base system means to a hospitality operation, especially when billing is involved. Although attitudes about computer systems, as well as the systems themselves have changed since this article was written, there is pertinent, fundamental information to be gleaned. In regards to the digression of the personal touch when a customer is engaged with a computer system, O’Brien says, “A modern data processing system should not force an employee to treat valued customers as numbers…” He also cautions, “Any computer system that decreases the availability of the personal touch is simply unacceptable.” In a system’s ability to process information, O’Brien suggests that in the past businesses were so enamored with just having an automated system that they failed to take full advantage of its capabilities. O’Brien says that a lot of savings, in time and money, went un-noticed and/or under-appreciated. Today, everyone has an integrated system, and the wise business manager is the business manager who takes full advantage of all his resources. O’Brien invokes the 80/20 rule, and offers, “…the last 20 percent of results costs 80 percent of the effort. But times have changed. Everyone is automating data management, so that last 20 percent that could be ignored a short time ago represents a significant competitive differential.” The evolution of data systems takes center stage for much of the article; pitfalls also emerge.