Acrylamide (AA) is one of the most common toxins in foods. Its
effect on bone microstructure has not been investigated. The aim
of our study was to analyze the impact of acute exposure to AA on
femoral bone microstructure in mice. Adult animals were treated
perorally with 2 doses of AA (E1 group, 1 mg/kg b.w.) in a 24-h
period and with 3 doses of AA (E2 group, 1 mg/kg b.w.) in a 48-h
period. Mice exposed to AA had smaller sizes of primary osteon's
vascular canals. Secondary osteons were significantly smaller in
mice from E2 group; however their increased number (from 38 %
to 77 %) was identified in both E1 and E2 groups. In these groups,
a higher number of resorption lacunae (from 100 % to 122 %) was
also found. The values for bone volume, trabecular number were
increased and that for trabecular separation was decreased in mice
administered AA. Significantly higher value of bone surface was
observed in mice from E1 group whereas trabecular thickness was
increased in E2 group. The effect of AA on microstructure of
compact and trabecular bone tissues is different. In our study, one
dose of AA was used and acute effects of AA were investigated.
Therefore, further studies are needed to study mechanisms by
which AA acts on bone.
The presented work is focused on the biomechanical study of the dental disk implant. The first part of the study deals with the strain analysis of the affected bone tissue and the dental implant loaded in the coronoapical direction by force 190 N. The study includes three types of implant anchorge, four degrees (stages) of osseointegration and nine degrees describing the quality of the cancellous bone. Two types of the disk implant were researched: single-disk and double-disk implant. Biomechanical study of the implant was focused on a stress-strain analysis of the affected bone rissue. The highest influence on the stresses in the bone tissue was primarily an implant anchorage. By the application of correlation relationships between Young modulus and the apparent density of the bone tissue - which is measurable in patients - we achieved the variable presented in this study. and Obsahuje seznam literatury
Taurine, a sulphur - containing amino acid, has been termed
a functional nutrient. Its synthetic form is a common ingredient
in supplements and energy drinks. There is no information
concerning taurine impact on bone microstructure after
prolonged supplemental use. Also, differences in bone
parameters of mice following taurine exposure are unknown. In
this study, a detailed microstructure of compact and trabecular
bone tissues of mice subchronically exposed to taurine was
determined. Animals (n=12) were segregated into three groups:
E1 group – mice received 20 mg/kg b.w. of taurine per day
during 8 weeks; E2 group – mice were fed by taurine at a dose
of 40 mg/kg b.w. for 8 weeks and a control (C) group. Decreased
density of secondary osteons, increased sizes of primary osteon's
vascular canals (P<0.05) were observed in taurine – treated
animals. Cortical bone thickness, trabecular thickness were
decreased (P<0.05) in E1 group, and relative volume of
trabecular bone was lower (P<0.05) in E2 group as compared to
C group. According to our results, prolonged taurine exposure at
the doses used in this study can negatively affect both compact
and trabecular bone tissues microstructure.
The purpose of the study was to test the hypothesis of different distribution spaces of elements in the rat mandibular bone and teeth. We used six adult males of Wistar laboratory rats for the study. After killing the animals, we extracted the molars and removed incisor crowns. The mandibular bone was divided into four parts (mesial-central-distal-ridge). Inductively coupled plasma mass spectrometry was used to determine the presence of 41 elements in the bone and tooth. Evidence of 14 elements was found in all samples (incisors-molars-bone). Generally, significant differences between the left and right side were found for K and Rb in the bone locations. As regards statistically significant differences in incisors-molars-bone locations, the elements for which these differences were found for all comparisons are listed as incisors versus individual molars, incisors versus bone locations, and individual molars versus bone locations: a) incisors-molars: Ba, Mn, Mo, Sr, Zn, K, Mg and Rb; b) incisors-bone: Fe, K, Mg, Mn, Na, Zn and Ba; c) molars-bone: Mn, Mo, Na and Mg. Statistically significant differences were also found between molars for Fe, Mg, Mn, and Sr and between bone locations for Ba, Ca, Mn, Sr, K, Rb, Zn, Mo, Mg, and Na. The elements Cu, Ni and Co were without pronounced differences. Twenty-seven elements were below the detection limit. Our results indicate different distributions of some elements in the rat mandibular incisors-molars-bone. We assume that the knowledge of chemical element contents in the laboratory rat bone and teeth will prove useful in experimental research of both these hard tissues. and Corresponding author: Ivo Němec