Efficacy and acceptance of a high-velocity microdroplet device for interdental cleaning in gingivitis patients-A monitored, randomized controlled trial.

OBJECTIVES: To compare in a randomized clinical trial the efficacy of a high-velocity microdroplet device for interdental cleaning vs dental floss at reducing plaque and gingivitis. METHODS: Sixty participants with an irregular interdental home cleaning regime were randomly assigned to use either a microdroplet device (n=40, test) or dental floss (n=20, control) for 4 weeks. At baseline and reassessment, the papilla bleeding index, the modified proximal plaque index and the amount of gingival crevicular fluid (GCF) were recorded. At the second appointment, participants completed a questionnaire regarding their assigned interdental cleaning option. The process quality of this investigator-initiated trial was ensured by independent scientific observers and media representatives. RESULTS: Improvement in the interdental cleaning routine reduced gingivitis in both groups (P<.05). The microdroplet device was more effective at reducing plaque (P=.003). The GCF amount remained the same in both groups. Comfort of use was greater with the microdroplet device. However, self-reported effectiveness was superior with dental floss. About 85% of participants using the microdroplet device said they would continue daily use. CONCLUSION: Improving the interdental cleaning routine with the microdroplet device or dental floss reduced gingivitis and plaque in both groups. Acceptance regarding comfort of use was higher with the microdroplet device. Dental floss remained the first choice for narrow interdental spaces, yet the microdroplet device offers an effective and well-accepted alternative for patients who fail the proper flossing routine.

Three-dimensional locations of destinations have species-dependent effects on the choice of paths and the gap-bridging performance of arboreal snakes.

Challenges for moving in arboreal environments include sizable gaps and variable three-dimensional locations between the discrete destinations created by branches. Different three-dimensional orientations of the body change the mechanical demands of crossing gaps, especially for elongate animals, but these effects on both the maximal gap distance crossed (Gapmax ) and the choice of destinations are poorly understood despite many animals frequently encountering these circumstances. We tested and compared the effects of three-dimensional gap location on the bridging ability of three species of snakes with similar length but moderately stout (Boa constrictor), intermediate (Pantherophis guttatus) or slender (Boiga irregularis) shapes, and we tested for bias in choice of destinations for the latter two species. The effects of both gap location and species on Gapmax were highly significant, and the rank order of species from greatest to least Gapmax was often from the most slender to the stoutest species. Although the effects of yaw (horizontal) angles were statistically significant, they were small compared to those of pitch (vertical) angles, which created nearly twofold variation in the values of Gapmax within each species. The greatest values of Gapmax occurred when snakes went straight down. Within a horizontal plane, P. guttatus and B. irregularis had similar preferences for choosing gaps with smaller yaw angles. However, when pitch angle was varied, P. guttatus preferred lower destinations, whereas B. irregularis preferred higher destinations. Thus, despite quite uniform effects of gap location on bridging abilities and torques acting on the animals, some preferences for locations were species specific. J. Exp. Zool. 319A:124-137, 2013. © 2012 Wiley Periodicals, Inc.

In utero administration of Ad5 and AAV pseudotypes to the fetal brain leads to efficient, widespread and long-term gene expression.

The efficient delivery of genetic material to the developing fetal brain represents a powerful research tool and a means to supply therapy in a number of neonatal lethal neurological disorders. In this study, we have delivered vectors based upon adenovirus serotype 5 (Ad5) and adeno-associated virus (AAV) pseudotypes 2/5, 2/8 and 2/9 expressing green fluorescent protein to the E16 fetal mouse brain. One month post injection, widespread caudal to rostral transduction of neural cells was observed. In discrete areas of the brain these vectors produced differential transduction patterns. AAV2/8 and 2/9 produced the most extensive gene delivery and had similar transduction profiles. All AAV pseudotypes preferentially transduced neurons whereas Ad5 transduced both neurons and glial cells. None of the vectors elicited any significant microglia-mediated immune response when compared with control uninjected mice. Whole-body imaging and immunohistological evaluation of brains 9 months post injection revealed long-term expression using these non-integrating vectors. These data will be useful in targeting genetic material to discrete or widespread areas of the fetal brain with the purpose of devising therapies for early neonatal lethal neurodegenerative disease and for studying brain development.

Mutations in the SIV env and the M13 lacZa gene generated in vitro by reverse transcriptases and DNA polymerases.

To investigate the accuracy of retroviral in vitro DNA replication we have examined with two fidelity assays the reverse transcriptases (RTs) from SIVagm, HIV-1, MoMLV as well for comparison the Klenow fragment from E. coli and DNA polymerase a from calf-thymus. These forward mutation assays measured the loss of bacteriophage M13 lacZa gene function by mutations. In the EnvlacZa assay frameshift mutations occurring during polymerisation of a 176 b long simian immunodeficiency virus (SIV) envelope (env) sequence were phenotypically detected by blue/white-plaque screening. To measure in addition substitutions, a 116 b long M13 lacZa gene DNA template was used as the mutational target (LacZa assay). With the SIVagm env gene DNA template, we observed similar levels of frameshift fidelity for all three RTs. Nevertheless, the SIVagm RT was slightly more accurate than the other RTs and nearly all frameshifts were observed at two homopolymeric runs of its homologous template. Measuring also substitution errors at the lacZa template the mutation frequency of the SIVagm RT increased 2.5 fold and that of the HIV-1 RT was enhanced by a factor of 3.

Differential expression of cerbB3 in naevi and malignant melanomas.

28 naevi, 43 malignant melanomas and 16 lymph nodes with melanoma metastases were stained immunohistochemically for the expression of cerbB3 oncoprotein. using antibody RTJ1. Positive reaction was found in 60% of naevi and in 25% of melanoma cases. The difference in frequency of the reaction occurrence between naevi and melanomas was statistically highly significant (p = 0.0017). In naevi, the percentage of cerbB3 positive cells (56.5%) was also significantly higher (p = 0.021) as compared with that of melanomas (37%). The cerbB3 positive cells were found only in cases without metastases. Positive reaction was also observed in 4 out of 16 investigated lymph nodes with melanoma metastases. The role of cerbB in the development of melanoma is discussed.

P-53 positivity and high proliferative index: factors of bad prognosis in malignant fibrous histiocytomas.

57 cases of malignant fibrous histiocytomas (MFH) were examined, immunohistochemically for the presence of p-53-tumour suppressor gene with monoclonal antibody DO-7 (Dako) and for the presence of Ki-67 antigen using monoclonal antibody MIB-1 (Dianova). The statistical relationship between the overexpression of p-53 and grading parameters (mitoses, cellularity, necrosis) and expression of Ki-67 antigen as well as survival time, was determined. The presence of p-53 antigen was found in 29.8% of grade II and grade III tumours, but not in MFH of grade I. The p-53 positive cases demonstrated a significantly higher mitotic index (p < 0.05), higher Ki-67 index (p < 0.05) and shorter survival time (p < 0.05) in comparison to p-53 negative cases. Differences concerning cellularity and extent of necrosis, between p-53 positive and p-53 negative tumours were not found (p > 0.05). The prognostic role of p-53 overexpression in MFH is discussed.

Detection of RNA-dependent DNA polymerase activity in the Xiphophorus melanoma system.

DNA polymerases have been isolated from muscle and melanoma tissues of Xiphophorus, which are similar to retroviral RNA-dependent DNA polymerases as they prefer RNA to DNA templates. They appear to associate with submicroscopic structures which exhibit a density of about 1.13 g/ml after sucrose-density-gradient centrifugation. The RNA-dependent-DNA-polymerase-like enzymes could be separated from the DNA-dependent DNA polymerases by DEAE-cellulose chromatography. Further purification on phosphocellulose revealed that the muscle enzyme eluted at the void volume and at about 0.6 M KCl, whereas most of the melanoma enzyme eluted at 0.1 M KCl. Comparison of the template primer specificities of the muscle and melanoma enzymes with those of known DNA polymerases showed obvious similarities to the RNA-dependent DNA polymerase isolated from Rous sarcoma virus.

Partial purification and characterization of the reverse transcriptase of the simian immunodeficiency virus TYO-7 isolated from an African green monkey.

The reverse transcriptase (RT) was partially purified by a newly developed procedure from the simian immunodeficiency virus TYO-7 isolated from an African green monkey (SIVagmTYO-7). The method comprised lysis of the virus with nonionic detergent followed by two centrifugations in isopycnic sucrose density gradients and one velocity sedimentation in a glycerol gradient. The enzyme exhibited a purity of 70-80% and showed an exceptional high specific activity of 135 nmol incorporation of dTMP per milligram of protein in 1 h with poly(rA).oligo(dT) as template-primer (TP). The molecular weight of the native enzyme was estimated by velocity sedimentation analysis as 120K-130K. Investigation of the RT by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the active enzyme is a heterodimer composed of a 64- and a 50-kDa subunit. The two subunits were identified to be RT specific by Western blot analysis. In activity gels, both subunits exhibited enzymatic activity, whereby the 64-kDa subunit showed the predominant activity. The RT preferred the TP poly(rA).oligo(dT) over poly(rC).oligo(dG). With poly(rCm).oligo(dG), only marginal activity was detected, and no activity was measured with poly(dA).oligo(dT). The TP specificity was influenced by the reaction temperature. The highest activity was measured around the melting temperature of the TP used. Furthermore, the enzyme activity was more thermolabile when measured with poly(rA).oligo(dT) than with poly(rC).oligo(dG). To compare the specificity of RT inhibitors, their inhibition efficiency (IE) was defined as the ratio of the 50% inhibiting concentration (ID50) obtained with the RT in viral lysates to the ID50 of purified RT.