Effect of mandibular and tongue protrusion on upper airway size during wakefulness

Oral appliances for the treatment of obstructive sleep apnea (OSA) produce either mandibular or tongue protrusion, and are thought to enlarge the upper airway (UA). We used videoendoscopy to measure UA cross-sectional area (CSA) and shape in the hypopharynx, oropharynx, and velopharynx during various stages of active mandibular and tongue protrusion during wakefulness in 10 patients with OSA and nine control subjects. Measurements were made in the supine position at end-tidal expiration, and were normalized to the CSA in the normal bite position. Airway shape was expressed as the anteroposterior/lateral (AP/L) diameter ratio. There were no differences between OSA patients and controls in the effects of mandibular and tongue protrusion on UA caliber. Both mandibular and tongue protrusion increased CSA in the hypopharynx and oropharynx (p < 0.001), whereas only tongue protrusion increased CSA in the velopharynx (p < 0.001). Tongue protrusion caused a greater increase in oropharyngeal and velopharyngeal CSA than did mandibular protrusion (p < 0.05). Mandibular protrusion caused a greater increase in CSA in the hypopharynx than in the oropharynx or velopharynx (p < 0.05). Obese patients had a larger relative increase in oropharyngeal CSA with mandibular and tongue protrusion than did subjects of normal weight. Tongue protrusion increased the AP/L diameter ratio in the oropharynx and velopharynx (p < 0.001), and mandibular protrusion did so to a lesser extent in the oropharynx (p < 0.01), resulting in a more circular airway shape. We conclude that mandibular and tongue protrusion increase the CSA and alter the shape of the UA during wakefulness.     

The material basis for reduced mechanical properties in oim mice bones

Osteogenesis imperfecta (OI), a heritable disease caused by molecular defects in type I collagen, is characterized by skeletal deformities and brittle bones. The heterozygous and homozygous oim mice (oim/+ and oim/oim) exhibit mild and severe OI phenotypes, respectively, serving as controlled animal models of this disease. In the current study, bone geometry, mechanics, and material properties of 1-year-old mice were evaluated to determine factors that influence the severity of phenotype in OI. The oim/oim mice exhibited significantly smaller body size, femur length, and moment of area compared with oim/+ and wild-type (+/+) controls. The oim/oim femur mechanical properties of failure torque and stiffness were 40% and 30%, respectively, of the +/+ values, and 53% and 36% of the oim/+ values. Collagen content was reduced by 20% in the oim/oim compared with +/+ bone and tended to be intermediate to these values for the oim/+. Mineral content was not significantly different between the oim/oim and +/+ bones. However, the oim/oim ash content was significantly reduced compared with that of the oim/+. Mineral carbonate content was reduced by 23% in the oim/oim bone compared with controls. Mineral crystallinity was reduced in the oim/oim and oim/+ bone compared with controls. Overall, for the majority of parameters examined (geometrical, mechanical, and material), the oim/+ values were intermediate to those of the oim/oim and +/+, a finding that parallels the phenotypes of the mice. This provides evidence that specific material properties, such as mineral crystallinity and collagen content, are indicative and possibly predictive of bone fragility in this mouse model, and by analogy in human OI.     

Research and Development as a Competence Creating Business in a Business

Research and development departments in industrial firms may not take it for granted anymore that they are the only preferred supplier of research and development to the company of which they are a part. The growing need to be innovative and the increasing availability of innovative competencies on the market result in a pressure on these departments to become more business–like and to reconsider their sources of competitive advantage over other (potential) suppliers of research and development. Traditionally, scientific and technological knowledge and skills concerning the product were the prime source. Nowadays, managerial competencies and the ability to work for and with your clients and suppliers are becoming more important. To become a competitive business in a business, research and development departments should create the competencies that enable them to create value for their clients. This calls for good competence management, comprising management of human resources, information technology, and internal and external interfaces. In this paper we explore what it means and what it takes for research and development departments to implement competence management, elaborating it theoretically and describing a case of competence management in the research and development department of a European car company.     

Oral contraceptive use and vaginal candida colonization

Fungal vaginal infections/colonisations can be divided into a symptomatic vaginal candidiasis and an asymptomatic vaginal Candida-carriage. The latter seems to be a predisposing factor for the development of a symptomatic vaginal candidiasis. The fungal organism isolated most frequently is Candida albicans, followed by Candida glabrata, which was previously also known as Torulopsis glabrata. To a lower extend, other Candida species such as Candida tropicalis and Candida krusei can be prevalent in the vulvovaginal region. Predisposing factors for vaginal candidiasis are gravidity, diabetes mellitus or a therapy with immunosuppressive agents. Also gestagenes showed to be a pre-disposing factor for vaginal candidiasis. Divergent results concerning the predisposition to vaginal candidiasis or colonisation due to oral contraception have so far been reported. Therefore we performed a study with two healthy collectives of female volunteers (n = 2 x 60) which were different concerning the taking of oral contraceptives. Overall, in 17% of the subjects (20/120) yeast could be cultured out of the vaginal secretions. There was no evidence for a higher rate of Candida-colonisation in subjects taking oral contraceptives. Further, there was no evidence for a relationship between the length of the taking of oral contraceptives and the rate of vaginal yeast-carriage. Also the type of oral contraceptive (combination or sequential contraceptive) had no influence on the frequency of Candida-carriage. Candida albicans was the most prevalent yeast (16/20), followed by Candida glabrata (4/20).     

Enhanced sensitivity of ubiquinone-deficient mutants of Saccharomyces cerevisiae to products of autoxidized polyunsaturated fatty acids

Coenzyme Q (ubiquinone or Q) plays a well known electron transport function in the respiratory chain, and recent evidence suggests that the reduced form of ubiquinone (QH2) may play a second role as a potent lipid-soluble antioxidant. To probe the function of QH2 as an antioxidant in vivo, we have made use of a Q-deficient strain of Saccharomyces cerevisiae harboring a deletion in the COQ3 gene [Clarke, C. F., Williams, W. & Teruya, J. H. (1991) J. Biol. Chem. 266, 16636-16644]. Q-deficient yeast and the wild-type parental strain were subjected to treatment with polyunsaturated fatty acids, which are prone to autoxidation and breakdown into toxic products. In this study we find that Q-deficient yeast are hypersensitive to the autoxidation products of linolenic acid and other polyunsaturated fatty acids. In contrast, the monounsaturated oleic acid, which is resistant to autoxidative breakdown, has no effect. The hypersensitivity of the coq3delta strains can be prevented by the presence of the COQ3 gene on a single copy plasmid, indicating that the sensitive phenotype results solely from the inability to produce Q. As a result of polyunsaturated fatty acid treatment, there is a marked elevation of lipid hydroperoxides in the coq3 mutant as compared with either wild-type or respiratory-deficient control strains. The hypersensitivity of the Q-deficient mutant can be rescued by the addition of butylated hydroxytoluene, alpha-tocopherol, or trolox, an aqueous soluble vitamin E analog. The results indicate that autoxidation products of polyunsaturated fatty acids mediate the cell killing and that QH2 plays an important role in vivo in protecting eukaryotic cells from these products.