Adverse reactions to denture resin materials

Irrespective of the new generation of dental materials, acrylates still have a wide indication field. Although they are classified as biomaterials, acrylates can have both local and systemic side effects. The individual components of the acrylic materials may leave the dental restorations and diffuse into saliva. The aim of this study was to point out the potentially toxic components of acrylic dental materials, as well as their possible adverse effects on oral tissues and the organism in general. The paper was based on the assumption that the appropriate selection of the type of acrylic material and the proper method of their preparation reduce their adverse effects to a minimum, which was proven using literature data.

Steady-state PERG adaptation: a conspicuous component of response variability with clinical significance

PURPOSE

To investigate within-test variability of the steady-state PERG (SS-PERG).

METHODS

SS-PERGs were recorded in response to black-white horizontal gratings (1.6 cycles/deg, 98% contrast, 15.63 reversals/s, LED display, 25 deg square field, 800 cd/sqm mean luminance) using skin electrodes. PERG and noise (± reference) signals were averaged over 1024 epochs (~ 2.2 min) and Fourier analyzed to retrieve SS-PERG amplitude and phase. SS-PERGs were split into 16 partial averages (samples) of 64 epochs each, and corresponding amplitudes and phases combined in polar coordinates to assess their dispersion (within-test variability). To assess time-dependent variability, samples were clustered in four successive time segments of ~ 33 s each. Amplitude adaptation was defined as amplitude difference between initial and final clusters, and PERG phase adaptation as the corresponding phase difference. To determine the dynamic range of SS-PERG adaptation, recording was performed in normal controls of different age (n = 32) and patients with different severity of optic nerve dysfunction (early manifest glaucoma, EMG, n = 7; non-arteritic ischemic optic neuropathy, NAION, n = 5).

RESULTS

Amplitude adaptation was largest in younger controls (amplitude adaptation ÷ noise, SNR = 9.5, 95% CI 13.1, 5.9) and progressively decreased with increasing age (older subjects, SNR = 5.5, 95% CI 9.2, 1.8) and presence of disease (EMG: SNR = 2.4, 95% CI 3.5, 1.4; NAION: SNR = 1.9, 95% CI 6.5,-2.2). In 11 young subjects, amplitude adaptation was repeatable (test-retest in two sessions a week apart; intraclass correlation coefficient = 0.59). Phase adaptation was not significantly different from zero in all groups.

CONCLUSIONS

SS-PERG adaptation accounts for a sizeable portion of the within-test variability. As it has robust SNR, sufficient test-retest variability, and is altered in disease, it may have physiological and clinical significance. This study suggests that SS-PERG protocols should include adaptation in addition to SS-PERG amplitude and phase/latency.

Translation of the Medical Fear Survey to Serbian: psychometric properties

BACKGROUND

Medical Fear Survey (MFS) is an instrument designed for measuring fear of medical and related treatments.

OBJECTIVE

Aim of the present study was MFS translation into Serbian, measurement of its psychometric properties and MFS validation using other Blood-injury-injections and related stimuli instruments that have been translated from English into Serbian.

METHOD

After obtaining permission from the author of the original MFS, double forward translation from English to Serbian and backward translation to English were conducted in ten steps, according to International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines. Reliability, factorial analysis and concurrent validation of Serbian version of MFS were conducted on a sample of 485 medical or pharmacy students at University of Kragujevac, Serbia.

RESULTS

Serbian version of MFS showed high internal consistency with a Cronbach's alpha 0.968 and good temporal stability after testing-and-retesting (Spearman's correlation coefficient 0.838, and intraclass correlation coefficient 0.877). Factorial analysis confirmed the same five factors demonstrated in the original English version: fear of mutilated bodies (10 items), fear of blood (11 items), fear of injections and blood draws (9 items), fear of sharp objects (10 items), and fear of medical examinations and physical symptoms (10 items). The total score of MFS correlated significantly with the total scores of Injection Phobia Scale-Anxiety (Spearman's correlation coefficient 0.391, p <0.001), Blood/Injection Fear Scale (Spearman's correlation coefficient 0.502, p <0.001) and Medical Avoidance Survey (Spearman's correlation coefficient 0.396, p <0.001).

CONCLUSIONS

Serbian version of the 50-item MFS showed similar psychometric properties as the original English version of this scale, with the same factorial structure. It could be used for measurement of fear of medical and related treatments in Serbian socio-cultural milieu, preferably self-administered. Hippokratia 2016, 20(1): 44-49.

The effects of quercetin on liver regeneration after liver resection in rats

The aim of the present study was to assess the influence of quercetine (QE) on liver regeneration after partial hepatectomy (PH) in rats. A total of 24 male Wistar albino rats were divided into three groups: sham-operated (SH), PH and PH+QE; each group contain 8 animals. The rats in QE-treated groups were given QE (15 mg/kg body weight) once a day i.p., for 7 days starting 3 days prior to hepatectomy operation. At 7 days after resection, liver samples were collected. The malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were estimated in liver homogenates. Moreover, histopathological examination, mitotic index (MI), proliferating cell nuclear antigen labelling, proliferation index (PI), transferase-mediated dUTP nick end-labelling assay, apoptotic index (AI) were evaluated at 7 days after hepatectomy. As a result, QE significantly increased MI, PI, and significantly decreased AI in PH rats. Additionally, QE remarkably inhibited the elevation of MDA, restored impaired antioxidant SOD activity and GSH level, and also attenuated hepatic vacuolar degeneration and sinusoidal congestion. These results suggested that QE treatment had a beneficial effect on liver regenerative capacity of the remnant liver tissue after hepatectomy, probably due to its antioxidative, antiapoptotic and proliferative property.

Disparities in policies, practices and rates of pediatric kidney transplantation in Europe

We aimed to provide an overview of kidney allocation policies related to children and pediatric kidney transplantation (KTx) practices and rates in Europe, and to study factors associated with KTx rates. A survey was distributed among renal registry representatives in 38 European countries. Additional data were obtained from the ESPN/ERA-EDTA and ERA-EDTA registries. Thirty-two countries (84%) responded. The median incidence rate of pediatric KTx was 5.7 (range 0-13.5) per million children (pmc). A median proportion of 17% (interquartile range 2-29) of KTx was performed preemptively, while the median proportion of living donor KTx was 43% (interquartile range 10-52). The median percentage of children on renal replacement therapy (RRT) with a functioning graft was 62%. The level of pediatric prioritization was associated with a decreased waiting time for deceased donor KTx, an increased pediatric KTx rate, and a lower proportion of living donor KTx. The rates of pediatric KTx, distribution of donor source and time on waiting list vary considerably between European countries. The lack of harmonization in kidney allocation to children raises medical and ethical issues. Harmonization of pediatric allocation policies should be prioritized.

Redox-dependent conformational selection in a Cys4Fe2S2 ferredoxin

Putidaredoxin (Pdx), a Cys4Fe2S2 ferredoxin from Pseudomonas putida, exhibits redox-dependent binding to its physiological redox partner, cytochrome P450(cam) (CYP101), with the reduced form of Pdx (Pdx(r)) binding with greater affinity to oxidized camphor-bound CYP101 than the oxidized form, Pdx(o). It has been previously shown that Pdx(o) is more dynamic than Pdx(r) on all accessible time scales, and it has been proposed that Pdx(r) samples only a fraction of the conformational substates populated by Pdx(o) on a time average. It is postulated that the ensemble subset populated by Pdx(r) is the same subset that binds CYP101, providing a mechanism for coupling the Pdx oxidation state to binding affinity for CYP101. Evidence from a variety of sources, including redox-dependent shifts of 15N and 13C resonances, indicates that the metal cluster binding loop of Pdx is the primary determinant of redox-dependent conformational selection. Patterns of paramagnetic effects suggest that the metal cluster binding loop contracts around the metal cluster upon reduction, possibly due to the strengthening of hydrogen bonds between the sulfur atoms of the metal cluster and the surrounding polypeptide NH and OH groups. Effects of this perturbation are then transmitted mechanically to other affected regions of the protein. A specific mutation has been introduced into the metal binding loop of Pdx, G40N, that slows conformational exchange sufficiently that the ensemble of conformational substates in Pdx(o) are directly observable as severe broadenings or splittings in affected NMR resonances. Many of the residues most affected by the mutation also show significant exchange contributions to 15N T(2) relaxation in wild-type Pdx(o). As predicted, G40N Pdx(r) shows a collapse of many of these multiplets and broadened lines to form much sharper resonances that are essentially identical to those observed in wild-type Pdx(r), indicating that Pdx(r) occupies fewer conformational substates than does Pdx(o). This is the first direct observation of such redox-dependent ensembles at slow exchange on the chemical shift time scale. These results confirm that conformational selection within the Fe2S2 cluster binding loop is the primary source of redox-dependent changes in protein dynamics in Pdx.