Erosion protection conferred by whole human saliva, dialysed saliva, and artificial saliva.

During dental erosion, tooth minerals are dissolved, leading to a softening of the surface and consequently to irreversible surface loss. Components from human saliva form a pellicle on the tooth surface, providing some protection against erosion. To assess the effect of different components and compositions of saliva on the protective potential of the pellicle against enamel erosion, we prepared four different kinds of saliva: human whole stimulated saliva (HS), artificial saliva containing only ions (AS), human saliva dialysed against artificial saliva, containing salivary proteins and ions (HS/AS), and human saliva dialysed against deionised water, containing only salivary proteins but no ions (HS/DW). Enamel specimens underwent four cycles of immersion in either HS, AS, HS/AS, HS/DW, or a humid chamber (Ctrl), followed by erosion with citric acid. During the cycling process, the surface hardness and the calcium released from the surface of the specimens were measured. The different kinds of saliva provided different levels of protection, HS/DW exhibiting significantly better protection than all the other groups (p < 0.0001). Different components of saliva, therefore, have different effects on the protective properties of the pellicle and the right proportions of these components in saliva are critical for the ability to form a protective pellicle.

[Effect of vitamin E-modified membrane on expression of coreceptors CD4, CD8 on lymphocytes in chronic hemodialysis patients]. / Wplyw celulozowej blony dializacyjnej pokrytej witamina E na ekspresje koreceptorów CD4, CD8 na limfocytach u pacjentów z przewlekla niewydolnoscia nerek leczonych hemodializami.

Chronic renal failure induces a clinical state of cellular and humoral immunodeficiency that also depends on the time duration of blood contact with the wide spectrum of dialysis membranes use during long-term hemodialysis treatments. In end stage renal failure (ESRD) patients it is possible to induct state of chronic inflammation mostly caused by leukocytes and complement activation. It is postulated that the vitamin E-coated dialysis membrane minimalizes unbiocompatible reactions that generate smaller amounts of reactive oxygen species (ROS). The purpose of this study was to analyze the effect of classical and vitamin E coated cellulose membranes on the expression of CD 4 and CD 8 adhesion molecules on lymphocytes during HD in 10 patients using flow cytometric analysis. The study protocol included the measurement of molecules expression using cellulose membrane (Clirans RS15, TERUMO Corp., Japan), and the same membrane coated by vitamin E (Excebrane, Clirans E15, TERUMO Corp., Japan) during 20 dialysis sessions with each kind of membrane. During dialysis with classical cellulose membrane, significant decrease of lymphocyte serum level and increase of lymphocyte CD4 expression was observed. During the session with vitamin E coated membranes we did not observe any significant changes in serum CD4, CD8, CD4+8+ lymphocyte level, and also lymphocyte CD4, and CD8 expression on lymphocytes. Our findings suggest the potential role of vitamin E-coated cellulose membrane to minimalize negative reaction of the T lymphocyte subpopulation in ESRD patients treated on long-term dialysis.

[Measurement of fluid compartments using electrical bioimpedance for assessment of target weight in hemodialysis patients]. / Pomiar przestrzeni wodnych za pomoca techniki bioimpedancji elektrycznej w celu oszacowania wagi oczekiwanej u pacjentów hemodializowanych.

The prescription of optimal hydration status in hemodialysis patients remains a much disputed topic in dialysis treatment. In particular, assessment of the patients optimal weight ("target weight") poses considerable difficulties. Multifrequency bioimpedance spectroscopy analysis (BIS) has been recommended as a non invasive, practical, and relatively non expensive method to determine hydration and nutritional status in patients on maintenance hemodialysis (HD). In the current study we used whole body BIS analysis for determination of body water (BW) compartments; total body water (TBW), extracellular water (ECW), and intracellular water (ICW) in 133 healthy adults, and in 227 hemodialysis patients with end-stage renal disease. BIS results were compared to anthropometric measurements. Our results showed strong correlation between TBW measured by BIS in control group in comparison to anthropometric calculation (p = 0.001). In HD patients we observed higher range of TBW, and TBW/ECW ratio (from 15.6 to 56.1 L and from 0.33 to 0.78), as measured by BIS at pre-HD, and also post-HD period (TBW ranged from 13.1 to 56.2 L, ECW/TBW ratio ranged from 0.33 to 1.27). The TBW BIS results did not correlate with anthropometric calculation. We postulate using of multi-frequency bioimpedance technique in precise determination of fluid compartments and in consequence in the assessment of "target weight" in hemodialysis population.

Flow-induced dilation of the dog gracilis muscle artery.

The external diameter of the artery (1.08 +/- 0.04 mm) predominantly supplying the gracilis muscle was monitored in situ in 12 dogs under thiopental anaesthesia using a contact inductive transformer. The blood flow in the artery could be controlled by an arteriovenous shunt. After a latency of 10.6 +/- 0.7 s, an increase of blood flow through the artery from 4.0 +/- 0.3 to 45.0 +/- 3.4 ml.min-1 induced an increase in its diameter by 44.9 +/- 3.6% of the resting value (p less than 0.001). When the blood flow-rate was reduced to the initial level, the artery constricted with a half-recovery time of 307.2 +/- 30.7 s. The amplitude and the time course of the arterial dilation were identical when the blood pressure at the site of diameter measurement decreased or remained unchanged. The dilation became maximal at blood flows corresponding to the peak of reactive hyperaemia in the gracilis muscle after 2 min arterial occlusion. It is being suggested that the blood flow-induced dilation ensures autostabilization of conduit artery function.