In situ analysis of usefulness of strontium-fluoride toothpaste for enamel remineralization

Aim. The aim of the study was to investigate the usefulness of an experimental fluoride toothpaste supplemented with Sr2+ for enamel remineralization. Material and methods. Two experimental groups comprised volunteers aged 20–30 years who had all the oral cavity sanation procedures carried out and all the primary and secondary caries lesions filled before undergoing investigations. The material included twenty healthy premolar teeth extracted for orthodontic reasons due to their abnormal position in the arch or to teeth crowding in 12–14 year old children. The teeth were sectioned into blocks and artificially demineralized. The samples were placed in the oral cavity on the buccal surfaces of the first molar teeth of volunteers who used toothpaste supplemented with Ca2+, P043-, F- (group I), toothpaste supplemented with Ca2+, P043-, F-, Sr2+ (group II) and control toothpaste supplemented with Ca2+, P043- (Hydroxyapatite-HAP). The content of calcium and phosphorus was analyzed on the lateral walls of the enamel lesions, at preselected depths of 15 Î1m and 100 Î1m, by using EDS microanalysis. Results. After three months, the content of calcium in both studied groups was significantly lower at 15 Î1m and 100 Î1m of enamel depth than at the baseline (immediately after enamel demineralization). After six months, the content of calcium was lower only at 15 Î1m in both groups. At 100 Î1m of depth the calcium content was significantly higher in group II and the reference group (HAP). After three months the phosphorus content was significantly lower in group II at 15 Î1m. After six months the content of phosphorous was significantly higher in group II at 15 Î1m and 100 Î1m of enamel depth. Conclusion. The results suggest that supplementation of fluoride toothpaste with strontium improved the effect of enamel remineralization

Ultrastructural evaluation of human metaphase II oocytes after vitrification: closed versus open devices

Objective: To compare the ultrastructural appearance of oocytes after vitrification and warming with two different devices. Design: Oocytes were examined by ultrastructural analysis after vitrification and warming with use of closed (CryoTip; Irvine Scientific, Santa Ana, CA) or open (Cryotop; Kitazato BioPharma Co., Ltd., Shizuoka, Japan) devices. Setting: Pordenone Hospital IVF Unit and Medical Morphological Research Department, University of Udine. Patient(s): Surplus oocytes from 10 patients (aged 31-39 years) undergoing assisted reproductive technologies at the Pathophysiology Unit of Human Reproduction and Sperm Bank between 2006 and 2008. Intervention(s): Oocytes with normal invertoscopic appearance underwent vitrification and warming with closed (CryoTip) or open (Cryotop) devices and were processed for transmission electron microscopy. Main Outcome Measure(s): Cryodamage extent and cell alterations in oocytes after open or closed vitrification and warming procedures and their rehydration rate. Result(s): A higher rate of complete oocyte rehydration and less-severe ultrastructural alterations were observed after vitrification and warming with the open Cryotop device. Conclusion(s): These preliminary data suggest that oocyte ultrastructure is better preserved with an open rather than closed vitrification and warming protocol

Osmotic tolerance and freezability of isolated caprine early-staged follicles

Isolated caprine early-staged follicles were submitted to osmotic tolerance tests in the presence of sucrose, ethylene glycol (EG), or NaCl solutions and were exposed to and cryopreserved (by slow or rapid cooling) in MEM alone or MEM supplemented with sucrose, EG (1.0 or 4.0 M), or both. When follicles were exposed to 1.5 M NaCl, only 2% of the follicles were viable, whereas 87% of the follicles were viable after exposure to 4.0 M EG. Regarding exposure time, the highest percentage of viable follicles was obtained when follicles were exposed for 10 min to 1.0 M EG + 0.5 M sucrose; exposure for 60 s to 4.0 M EG + 0.5 M sucrose also maintained high percentage viability in follicles. Slow cooling in the presence of 1.0 M EG + 0.5 M sucrose (75%) or rapid cooling in the presence of 4.0 M EG + 0.5 M sucrose (71%) resulted in a significantly higher proportion of viable follicles than all other treatments (P < 0.05). A 24-h culture of frozen-thawed follicles was used to assess survival; only slow-frozen follicles showed viability rates similar to control follicles (64% vs. 69% respectively; P > 0.05). Interestingly, the percentage of viable rapid-cooled follicles (59%) was similar to that obtained after in vitro culture of conventional slow-cooled follicles but was significantly lower than that in controls. Thus, in addition to determining improved procedures for the exposure of follicles to EG and sucrose before and after freezing of caprine early-staged follicles, we report the development of rapid- and slow-cooling protocols

Cryopreservation of animal oocytes and embryos: current progress and future prospects

Cryopreservation describes techniques that permit freezing and subsequent warming of biological samples without loss of viability. The application of cryopreservation in assisted reproductive technology encompasses the freezing of gametes, embryos and primordial germ cells. Whilst some protocols still rely on slow-freezing techniques, most now use vitrification, or ultra-rapid freezing, for both oocytes and embryos due to an associated decreased risk of damage caused by the lack of ice crystal formation, unlike in slow-freezing techniques. Vitrification has demonstrated its use in many applications, not only following in vitro fertilisation (IVF) procedures in human embryology clinics, but also following in vitro production (IVP) of embryos in agriculturally important, or endangered animal species, prior to embryo transfer. Here we review the various cryopreservation and vitrification technologies that are used in both humans and other animals and discuss the most recent innovations in vitrification with a particular emphasis on their applicability to animal embryology

Valproate, thalidomide and ethyl alcohol alter the migration of HTR-8/SVneo cells

BACKGROUND: Valproate, thalidomide and alcohol (ethanol) exposure during the first trimester of pregnancy is known to cause several developmental disorders. All these teratogens are known to pass the placental barrier and interfere directly with the normal development of the fetus. However, these teratogens also alter the formation and function of the placenta itself which may in turn affect the proper nourishment and development of the fetus. Optimum development of the placenta requires adequate invasion of trophoblast into the maternal uterine tissues. Changes in the migratory behavior of trophoblast by maternal exposure to these teratogens during placentogenesis may therefore alter the structure and function of the placenta. METHODS: In the present study, the effects of sodium valproate, thalidomide and alcohol on the migration of human first trimester trophoblast cell line (HTR-8/SVneo) were examined in vitro. Cells were cultured in the wells of 48-well culture plates as mono or multilayers. Circular patches of cells were removed from the center of the wells by suction, and the migration of cells into the wound was studied using microscopy. Effects of low and high concentrations of valproate, thalidomide and alcohol were examined on the healing of wounds and on the migration rate of cells by determining the wound areas at 0, 3, 6, 12, 24 and 48 h. Effects of drugs and alcohol on the proliferation and the expression levels of integrin subunits beta1 and alpha5 in cells were examined. RESULTS: The migration rates of trophoblast differed between wounds created in mono and multilayers of cells. Exposure to teratogens altered the migration of trophoblast into mono and multilayer wounds. The effects of valproate, thalidomide and alcohol on the proliferation of cells during the rapid migratory phase were mild. Drug exposure caused significant changes in the expression levels of beta1 and alpha5 integrin subunits. CONCLUSION: Results suggest that exposure to valproate, thalidomide or alcohol during the first trimester of pregnancy may change the ultrastructure of the placenta by altering the migration of trophoblast cells and this effect may be mediated by drug- or alcohol-induced changes in the expression levels of beta1 and alpha5 integrin subunits

Contractor defects in waterproofing - selected examples

Artykuł podejmuje tematykę związaną z hydroizolacją obiektów budowlanych. Na wstępie wyjaśniono podstawowe różnice pomiędzy izolacją przeciwwilgociową a przeciwwodną oraz wskazano zakres ich stosowania. Przygotowano diagram związany z głównymi przyczynami usterek w izolacjach przeciwwodnych. W kolejnym punkcie przedstawiono wybrane przykłady błędów wykonawczych wraz z opisem przyczyny ich powstania. Przykłady zobrazowano za pomocą licznych fotografii przedstawiających skutki błędnie wykonanych izolacji. Zaprezentowane przykłady są bezpośrednio związane z doświadczeniem zawodowym autora. Wskazano również błędy wykonawcze zamieszczając tabelę rozwiązań minimalizujących ich powstawanie. Wnioski podsumowują zakres opracowania, zwracając szczególną uwagę na koszty powstałych usterek.The article presents topics related to the waterproofing of buildings. At the outset, the basic differences between moisture and water insulation and the scope of their application are explained. A diagram was prepared related to the main causes of defects in waterproofing. An overview of selected examples of performance errors and a description of their occurrence. Examples of photos illustrated by means of analysis showing the effects of incorrectly made insulation. The examples presented are related to the author's professional experience. In the last presentation of implementation errors created tables of solutions to minimize their occurrence. The conclusions summarize the scope of the refund paying attention to the costs of defects

Ways of precast columns assembly

W artykule przedstawiono sposoby rozwiązań dla połączenia prefabrykowanych słupów ze stopą fundamentową. Początkowo krótko omówiono znaczenie prefabrykacji na styku tych elementów. W kolejnych punktach opisano najczęściej spotykane współcześnie sposoby montażu słupów wraz ze wskazaniem ich zalet oraz wad. Rozwiązania usystematyzowano chronologicznie, zaczynając od tych stosowanych najdawniej.The article presents ways of solutions for connecting precast columns with the foot foundation. It discusses briefly the importance of prefabrication between these elements. The following sections describe the most common modern methods of columns assembly, indicating their advantages and disadvantages. Solutions were systematized chronologically, beginning with those used least recently