Oral health in youth with visual impairment: A longitudinal survey.

This longitudinal survey aims to demonstrate improvement in oral hygiene among a group of youth with visual impairment (VI) achieved by repeated oral hygiene training, compare their progress with healthy peers (CG) and assess their oral health knowledge. In 100 VI (55♀, 45♂; ± 17.8 years) and 45 CG (23♀, 22♂; ± 17.2 years) oral hygiene training and a Quigley-Hein Plaque Index (QHI) rating were repeated six times at three-month intervals. The VI were divided into four subgroups according to the toothbrush hardness/type. A questionnaire was given to both groups. Appropriate statistical analyses were performed at 5% significance level. Both groups showed reduction in QHI, the VI had overall higher QHI values than CG. Use of an electric toothbrush in VI led to lower QHI in the last examination (p < 0.03). 69% of participants recommended dental specialists to improve communications by acquiring more illustrative aids. VI changed toothbrush less often (p < 0.02). A higher incidence of dental plaque was confirmed in VI compared to CG. After education and individual training, gradual plaque reduction has occurred in both groups. Using an electric toothbrush in VI resulted in better QHI outcomes. Repetitive preventive intervention in youth with VI helped them to adopt healthier oral hygiene habits.

The influence of land-use on tropical soil chemical characteristics with emphasis on aluminium.

Composition of soil vegetation cover and land management directly influences the cycling of chemical elements and is a key factor for soil biogeochemistry and also Al behaviour. Moreover, Al is an important factor limiting the growth of cultural plants. Our results are based on long-term observations of soils translocated from selected small areas of eight 1 ha plots of different land-use gradient, with identical geological, climatic and geographical conditions, located in the North of Congo Basin (near Mbalmayo, Cameroon). The plots are established in primary and secondary forests, cocoa agroforestry systems and a maize field (two plots per habitat). All soil plots were exchanged between each other in two layers; A. 0-5 cm, and B. 5-20 cm of depths. The soil was sampled at the times 0, +3, +6 months, and soil chemical parameters were determined. The most important differences between the particular habitats comprise of vegetation cover as a consequence of the land management. Particular plots differed mainly in their pH, organic C, exchangeable Al and contents of base cations. The most marked trends comprise of significant decrease of pH, increase of Al and decrease of the Ca/Al ratio in A layer after translocation to the agricultural plots. All translocations resulted into rapid loss of organic C and release of Al, which was more obvious when the forest-to-agriculture translocation took place.

Abnormal myocardial and coronary vasculature development in experimental hypoxia.

Oxygen availability is one of the necessary prerequisites for normal embryonic development. In our previous study we found that quail embryos incubated under hypoxic conditions (16% O(2)) die at embryonic day (ED) 9 with signs of heart failure. By ED4 and ED6 we found thinner ventricular wall and increased capillary density. We thus hypothesized that the cause of death would lie in severe myocardial and coronary maldevelopment. ED6 and 7 hypoxic hearts had thinner ventricular wall, especially left. There was a simultaneous increase in capillary density, most pronounced in the interventricular septum. This site corresponds to an area of tissue hypoxia and ensuing increased angiogenesis, and also formation of ventricular conduction system. Hypoxia had a positive effect on normal sequence of maturation of the conduction system evaluated by optical mapping at ED7. In sections from ED9 hypoxic hearts we found, in addition to thinner ventricular walls, irregularities in development of coronary tree (missing coronary ostia, absence of one coronary artery, and irregular arterial wall). This deficiency was due to decreased myocyte proliferation rather than to increased apoptosis. By Indian ink injection through the left ventricle we found in normoxic hearts regular coronary branching pattern, while in the hypoxic ones there was often only an irregular plexus. Embryonic hypoxia thus leads to increased capillarity and trabeculation to minimize diffusion distance. In the subsequent period there is a failure in organization of vascular plexus into normal vasculature, resulting in thin compact myocardium that likely leads to heart failure and embryonic death.

Hemocompatible albumin-heparin coatings prepared by the layer-by-layer technique. The effect of layer ordering on thrombin inhibition and platelet adhesion.

Using the layer-by-layer technique, ELISA polystyrene plates were coated with multilayer assemblies of albumin with various heparins or with multilayer assemblies of albumin. The coatings containing heparin were tested for their ability to potentiate thrombin inhibition by antithrombin and its dependence on the layer arrangement. The order of activities of surface bound heparins matched their order in solution; however their activity was reduced to less than 10% due to binding. The increasing number of layers increased the activity of the coatings suggesting that heparin inside the assemblies is available for the interaction. The albumin-heparin assemblies overcoated with albumin layers preserved about half of heparin activity. Platelets adhered in similar amounts to albumin-heparin and albumin coatings; however, in both cases platelets adhered more to single layer than to multilayer coatings. The adhesion of platelets to single layer coatings was also affected by the crosslinking of the coatings; more platelets adhered to less crosslinked single layer coatings while multilayer coatings remained essentially unaffected by crosslinking. If the coatings were dried and reswollen, a substantial number of platelets adhered to the reconditioned single layer coatings but the two layer coatings were affected much less and the adhesion of platelets to the coatings with three layers was close to normal. A minimum of three albumin-heparin or albumin layers is apparently required to shield the underlying surface and to achieve proper functioning of the coatings.

Oxidative stress and platelet function in multiple myeloma and renal insufficiency: clinical relations of different tests.

Hemorrhagic tendency is frequent in uremic patients and is often associated with prolonged bleeding time and decreased platelet functions in vitro. Similarly, in multiple myeloma, platelet functions are affected, mainly by the inhibitory effect of paraprotein. We have studied patients with renal insufficiency and multiple myeloma to investigate the possible relation of oxidative stress to platelet functions, adhesion and aggregation activity. We observed diminished platelet aggregation response to collagen, ADP and thrombin receptor-activating peptide (TRAP) in both groups of patients as compared with normals. The adhesion of platelets to fibrin dimers was also diminished. Malondialdehyde concentration as a criterion of oxidative stress was significantly enhanced in both groups of patients together with increased concentrations of vitamins A and E. It seems to be possible that oxidative stress contributes to modification of adhesion proteins and fibrinogen and, thus, augments the observed inhibitory influence of vitamin E on platelet aggregation and adhesion. In conclusion, the concerted influence of both malondialdehyde and vitamins A and E can contribute to diminished platelet functions in renal insufficiency and augment the inhibitory influence of paraprotein on platelet functions in multiple myeloma.