In vitro radiographic density of dental posts measured by digital radiography

Objectives This study evaluated the radiopacity of seven commercial root canal posts. Digital radiographs of the seven commercial posts and of the same commercial posts and four artificial aluminum posts inserted in lower canines were obtained with a CCD-based digital sensor. The radiopacity of the posts was expressed as mm aluminum/mm material (mmAl). Subsequently, the radiographs were presented to five trained evaluators who were asked to rank their acceptability scores as not acceptable, acceptable, or excellent. Analysis of variance revealed significant differences in radiopacity among the posts (P < 0.05). The radiopacities of zirconium and titanium posts were significantly higher than those of fiber posts (P < 0.05). The minimum aluminum thickness for acceptance in the root canals was 1.2 mmAl. All of the examined posts presented satisfactory radiopacity for clinical application.Ivoclar Vivadent; Ministry of Science and Education of the Republic of Serbia {[}45005

Membrane Steroid Receptor-Mediated Action of Soy Isoflavones: Tip of the Iceberg

Soy isoflavone's (genistein and daidzein in particular) biological significance has been thoroughly studied for decades, so we started from the premise that refreshed investigation approach in this field should consider identification of their new molecular targets. In addition to recently described epigenetic aspects of polyphenole action, the cell membrane constituents-mediated effects of soy isoflavones are worthy of special attention. Accordingly, the expanding concept of membrane steroid receptors and rapid signaling from the cell surface may include the prominent role of these steroid-like compounds. It was observed that daidzein strongly interacts with membrane estrogen receptors in adrenal medullary cells. At low doses, daidzein was found to stimulate catecholamine synthesis through extracellular signal-regulated kinase 1/2 or protein kinase A pathways, but at high doses, it inhibited catecholamine synthesis and secretion induced by acetylcholine. Keeping in mind that catecholamine excess can contribute to the cardiovascular pathologies and that catecholamine lack may lead to depression, daidzein application promises to have a wide range of therapeutic effects. On the other hand, it was shown in vitro that genistein inhibits LNCaP prostate cancer cells invasiveness by decreasing the membrane fluidity along with immobilization of the androgen receptor containing membrane lipid rafts, with down regulation of the androgen receptors and Akt signaling. These data are promising in development of the molecular pharmacotherapy pertinent to balanced soy isoflavone treatment of cardiovascular, psychiatric, and steroid-related malignant diseases.Ministry of Science, Education and Technological Development of the Republic of Serbia {[}173009

The influence of different radiopacifying agents on the radiopacity, compressive strength, setting time, and porosity of Portland cement

The aims of this study were to evaluate the radiopacity, compressive strength, setting time, and porosity of white Portland cement (PC) with the addition of bismuth oxide (Bi2O3), zirconium dioxide (ZrO2), and ytterbium trifluoride (YbF3) after immersion at 37 A degrees C for 7 days in distilled water or phosphate buffer saline. Specimens measuring 8 mm in diameter and 1 mm in thickness were fabricated from PC with the addition of 10, 20, and 30 wt% Bi2O3, ZrO2 or YbF3. ProRoot MTA (Dentsply, Tulsa, OK, USA) and pure PC were used as controls. For radiopacity assessments, specimens were radiographed alongside a tooth slices and an aluminum stepwedge on Extraspeed occlusal dental films (Insight Kodak, Rochester, New York). Mean optical density of each specimen was calculated and used to express radiopacity of the material as an equivalent thickness of aluminum. Compressive strength was measured by using 4-mm diameter and 6-mm high specimens and Universal testing machine. High-pressure mercury intrusion porosimeter (Carlo Erba Porosimeter 2000) was employed to measure the porosity of the specimens. The setting time was measured by using a needle of 100 g in weight. The morphology of specimens was evaluated using a scanning electron microscope (TESCAN Mira3 XMU, USA Inc.). Data were analyzed by one-way ANOVA and post hoc Tukey test (P LT 0.05). The PC with the addition of at least 10 wt% Bi2O3 and 20 wt% ZrO2 or YbF3 demonstrated greater radiopacity value than the recommended 3 mmAl cut-off. ZrO2 and YbF3 increased the compressive strength of PC, but it was not statistically significant (P > 0.05), while Bi2O3 decreased it (P LT 0.05). All radiopacifiers significantly increased the porosity of the experimental cements (P LT 0.05). Bi2O3 extended the setting time of PC (P LT 0.05), whilst ZrO2 and YbF3 did not significantly affect it (P > 0.05). ZrO2 and YbF3 may be used as a suitable alternative to replace Bi2O3 in MTA without influencing its physical properties

THE EFFECTS OF ESTRADIOL AND HUMAN CHORIONIC GONADOTROPIN ON ACTH CELLS IN PERIPUBERTAL FEMALE RATS: A HISTOLOGICAL AND STEREOLOGICAL STUDY

The effects of estradiol (EDP) and human chorionic gonadotropin (HCG) on histological and stereological features of adrenocorticotropic (ACTH) cells in peripubertal female rats were examined. The first group of females received five injections of EDP (0.25 mg/kg b.w.), every second day from the 4th to 14th day after birth, and was killed at the peripubertal stage. The second group of females was given two injections of pregnyl-gonadotrophinum chorionicum (HCG; 50 IU/kg body weight) on the 36th and 37th days after birth, and it was killed 24 h after the last treatment. The controls were injected with an equivalent volume of the corresponding vehicle. ACTH cells were immunohistochemically labeled and stereologically evaluated. Stereological analysis showed that the volume of ACTH cells and their volume density in peripubertal females treated with EDP, were decreased by 15.6\% and 53.8\% (p < 0.05), respectively, compared to the controls. In HCG-treated animals, the observed parameters were increased by 39.2\% and 15.4\% (p < 0.05), respectively, in comparison with the control females. These findings suggest that the application of EDP or HCG exerted opposite effects on the stereological features of pituitary ACTH cells.Ministry of Education, Science and Technological Development of the Republic of Serbia {[}ON 173009

Exposure to dexamethasone reduces pituitary volume and gonadotropic cell number in rat fetuses

Overexposure to glucocorticoids during the fetal period induces changes in developmental processes in various fetal tissues. The aim of this study was to investigate the effects of the synthetic glucocorticoid, dexamethasone (Dx), on pituitary volume and gonadotropic cells during a critical period of pituitary development. The effects of Dx on stereological parameters of the pituitary gland and FSH and LH cells were investigated in 19 and 21-day old fetuses. On day 16 of pregnancy, the experimental dams received 1.0 mg Dx/kg b.w. subcutaneously, followed by 0.5 mg Dx/kg b.w./day on days 17 and 18 of gestation. The control gravid females received the same volume of saline. FSH and LH cells were stained immunohistochemically by the peroxidase-antiperoxidase method (PAP). In 19-day old fetuses, exposure to Dx caused a significant decrease of pituitary volume, estimated by Cavalieri's principle. Also, the total number of FSH and LH cells per pituitary, determined by physical fractionator counting technique, was significantly reduced. These changes persisted until fetal day 21. Volume densities and numerical densities of FSH and LH cells after exposure to Dx in 19 and 21-day old fetuses remained unaffected. Our results suggest that altered stereological parameters in pituitary gland after exposure to dexamethasone in fetal period could be long-lasting. (C) 2014 Elsevier GmbH. All rights reserved.Ministry of Education, Science and Technological Development of the Republic of Serbia {[}173009

IMMUNO-HISTOMORPHOMETRIC AND -FLUORESCENT CHARACTERISTICS OF GH CELLS AFTER TREATMENT WITH GENISTEIN OR DAIDZEIN IN AN ANIMAL MODEL OF ANDROPAUSE

Somatopause, the complex aspect of andropause, is recognizable by reduced growth hormone - GH/insulin-like growth factor 1 axis function in the ageing male. Soy isoflavones (usually genistein and daidzein), which are known for their beneficial effects in the treatment of ageing symptoms, are active in the pituitary, as well. The iromuno-histomorphometric and fluorescent characteristics of pituitary growth hormone secreting cells, in an animal model of andropause, were examined after a treatment with genistein or daidzein. Andropausal Wistar rats were divided into sham operated, orchidectomized and genistein or daidzein treated orchidectomized groups. Genistein or daidzein (30 mg/kg/day) were administered subcutaneously for three weeks, while sham operated and orchidectomized groups received the vehicle alone. Growth hormone secreting cells were identified by the percoxidase-antiperoxidase immuno-histochemical, and inmuno-fluorescent procedure. The main characteristic of growth hormone secreting cells in soy isoflavones treated groups is a weaker immuno-histochemical staining and immuno fluorescent signal compared to sham operated and orchidectomized groups. The growth hormone secreting cell volume in orchidectomized +genistein or +daidzein groups is by 13.8\% and 11.9\% (p<0.05) smaller respectively, in comparison with the orchidectomized group. In orchidectomized +genistein or +daidzein groups, the growth hormone secreting cells relative volume density is by 62.5\% and 61.0\% lower (p<0.05) respectively than for the sham operated group, and decreased by 65.4\% and 64.0\% (p<0.05) respectively, compared to the orchidectomized group. It can be concluded that chronic genistein or daidzein treatment, in an animal model of andropause, attenuates immuno-histomorphometric and fluorescent characteristics of growth hormone secreting cells.Ministry of Education, Science and Technological Development of the Republic of Serbia {[}173009

Effects of genistein on stereological and hormonal characteristics of the pituitary somatotrophs in rats

The hypothalamic-pituitary somatotropic system plays a pivotal role in the regulation of physiological processes and metabolism, which is modulated by gonadal steroids. Considering that genistein belongs to the phytoestrogen family and acts via similar mechanisms to estrogens, the present study was designed to demonstrate whether genistein modulates the morphofunctional characteristic of somatotrophs {[}growth hormone (GH) cells] in adult rats in comparison with the effects of estradiol. In the study, the orchidectomized adult rats were used as an appropriate model system for testing the effects of this hormone-like substance. Changes in the pituitary somatotrophs were evaluated histologically and stereologically, while GH level was determined biochemically. Using immunolabelling and stereological methods, we showed that orchidectomy (Orx) provoked the decrease of GH cell volume density. After estradiol treatment of Orx rats, the most prominent change concerned the pituitary relative intensity of GH fluorescence and circulating GH level, which were elevated 77 \% and 4.7-fold, respectively. Clearly, in contrast to orchidectomy, estradiol treatment enhanced the GH cells activity. Genistein treatment increased pituitary weight and volume, GH cell volume density, the total number of GH cells, and GH blood concentration (1.3-fold) in comparison to the Orx group. Although identical tendencies followed estradiol and genistein administration, the changes observed after genistein treatment were milder compared to estradiol treatment.Ministry of Education and Science of Serbia {[}173009

Diosgenin does not express estrogenic activity: a uterotrophic assay

This study assessed the effects of diosgenin on estrogenic activity using a uterotrophic assay. Immature female rats received diosgenin orally at doses of 200, 100, or 20 mg/kg body mass; and 17 alpha ethynylestradiol at doses of 1 or 0.3 mu g/kg, daily, for 3 consecutive days from day 19 to day 21. Controls were distributed among 2 groups: an intact control group and a vehicle control group. Animals were sacrificed 24 h after the last application of diosgenin, estradiol, or vehicle (22nd day of life). Uterine wet weight, stereological and histomorphometrical changes, immunohistochemical expression of estrogen receptor alpha (ER alpha), progesterone receptor (PR), and the expression of lactoferrin (LF) were examined. Diosgenin did not affect the uterine wet weight, epithelium height, volume densities of endometrium, endometrial epithelia, number of endometrial glands, or histological appearance of vaginal epithelia. ER alpha, PR, and LF immunostaining intensity were not altered in the animals that received diosgenin. High-potency reference ER agonist 17 alpha-ethynylestradiol induced a significant increase in all of the measured parameters, and as expected, decreased ER alpha immunostaining intensity. Based on these data, it can be concluded that diosgenin, at doses of 20-200 mg/kg, did not act as an estrogen agonist in the immature rat uterotrophic assay.Ministry of Education, Science, and Technological Development of the Republic of Serbia {[}173009

Effects of soy phytoestrogens on pituitary-ovarian function in middle-aged female rats

The aim of this study was to assess the effects of genistein (G) and daidzein (D) on the histological, hormonal, and functional parameters of the pituitary-ovarian axis in middle-aged female rats, and to compare these effects with the effects of estradiol (E), commonly used in the prevention and treatment of menopausal symptoms. Middle-aged (12 month old) Wistar female rats subcutaneously received 35 mg/kg of G, or 35 mg/kg of D, or 0.625 mg/kg of E every day for 4 weeks. Each of the treated groups had a corresponding control group. An intact control group was also established. G and D did not change the intracellular protein content within gonadotropic and lactotropic cells, but vacuolization was observed in all the cell types. In contrast, E caused an inhibition of gonadotropic and stimulation of lactotropic cells. Also, ovaries of middle-aged female rats exposed to G or D have more healthy primordial and primary follicles and less atretic follicles. E treatment in the ovaries had a mostly negative effect, which is reflected by the increased number of atretic follicles in all tested classes. G and D provoked decrease in CuZnSOD and CAT activity, while E treatment increased MnSOD and decreased CuZnSOD and GSHPx activity. All the treatments increased serum estradiol and decreased testosterone levels, while D and E increased the serum progesterone level. In conclusion, soy phytoestrogens exhibited beneficial effects on pituitary-ovarian function in middle-aged female rats, as compared to estradiol.Ministry of Education, Science and Technological Development of the Republic of Serbia {[}173009