Early iron deficiency produces persistent damage to visual tracts in Wistar rats

In this study, morphological changes in the optic nerve were determined by light microscopy in Wistar rats on an iron-deficient diet for 32 days or for 21 days followed by 10 days on an iron-recovery diet. The morphometric findings showed significantly fewer blood vessels and oligodendrocytes in the iron-deficient rats and iron-recovery rats than in the control group, as well as more astrocytes in the iron-recovery rats. Serum iron levels of the iron-deficient rats were significantly lower than those of the controls. On the other hand, iron-recovery rats had normal serum iron levels, but no change in the abnormal morphology of the myelinated axons and morphometric parameters. Our data indicate that iron is necessary for maintenance of the optic nerve cell structure, and morphological damage from iron-deficiency is not easily reverted by iron reposition.

Iron Fortification Strategies for the Control of Childhood Anemia in Brazil

This article presents data on the fortification of foods, necessary as an important public health approach for the success in reducing anemia. The use of food vehicles, iron salts and their costs, as well as recent work on iron fortification of foods in Brazil are reviewed. Recent research serves as a cornerstone for countries that attempt to implement permanent, long-lasting iron fortification programs aimed at the prevention of anemia considering cultural habits, type of iron salts and at-risk groups.

Protective efficacy of bacterial membranes containing surface-exposed BM95 antigenic peptides for the control of cattle tick infestations

The Rhipicephalus (Boophilus) microplus BM86 and BM95 glycoproteins are homologous proteins that protect cattle against tick infestations. In this study, we demonstrated that the recombinant chimeric protein comprising tick BM95 immunogenic peptides fused to the A. marginale MSP1a N-terminal region for presentation on the Escherichia coli membrane was protective against R. microplus infestations in rabbits. This system provides a novel and simple approach for the production of tick protective antigens by surface display of antigenic protein chimera on live E. coli and suggests the possibility of using recombinant bacterial membrane fractions for vaccination against cattle tick infestations. (C) 2009 Elsevier Ltd. All rights reserved.

Liver iron overloading in captive muriquis (Brachyteles spp.)

Background Iron accumulation was investigated qualitatively and quantitatively in the liver of 15 captive Brachyteles spp. Methods Hepatic hemosiderosis index (HHI) was determined as the area percentage of the liver parenchyma occupied by hemosiderin and ferritin deposits, through computerized histomorphometric analysis of Prussian blue-stained histologic sections. Results All studied animals presented liver hemosiderosis, and HHI ranged from 0.2% to 41.7%. There were no significant differences in HHI between muriqui species or genders, and no correlations were detected among HHI and age, time in captivity or body mass. Iron deposits were accompanied by other hepatic disorders. Conclusions This is the first study addressing the occurrence and consequences of iron overloading in the liver of muriquis. We propose that hemosiderosis may act as a contribute factor for the development of hepatic injuries. Further studies are advised to clarify the role of diet in the pathogenesis of hemosiderosis in these atelids.

Postpartum ovarian activity of Santa Ines lactating ewes fed diets containing soybean hulls as a replacement for coastcross (Cynodon sp.) hay

The Santa Ines, a Brazilian hair sheep, has a non-seasonal breeding activity. Data regarding the duration of the postpartum anestrous period in Santa Ines lactating ewes is lacking and the objective of this trial was to determine the effects of replacing neutral detergent fibre (NDF) provided by coastcross (Cynodon sp.) hay with NDF contained in soybean hulls (SH) on the postpartum ovarian activity-as measured by the serum progesterone (P(4)) concentration. Fifty-six lactating ewes (body weight 56.1 +/- 6.8 kg) were individually penned and used in a randomized complete block design with 14 blocks and four treatments. The SH NDF replaced 33 (SH33), 67 (SH67), or 100% (SH100) of the NDF contributed by coastcross hay in the control diet (SHO). This resulted in a SH inclusion at rates of 0, 25, 54, and 85% of the dietary dry matter (DM). Blood samples were collected twice weekly from the 14th to 84th day postpartum and the serum P(4) concentrations determined by radioimmunoassay (RIA). It was estimated that the 1st postpartum ovulation occurred 6 days before the date that a serum P(4) >= 1 ng/ml concentration was first recorded. The mean body condition score (BCS; 0-5 scale) was 3.0 +/- 0.19 on day 14 postpartum and the mean BCS at day 56 postpartum increased linearly (P<0.01) with the inclusion levels of SH (3.09, 3.24, 3.34, and 3.36, respectively). Treatments did not differ significantly in the induction of postpartum days to the resumption of ovarian luteal activity (34.1 +/- 15.3 days postpartum). On days 25, 50, and 75 postpartum 36.80, and 100% of the ewes had resumed ovarian activity, respectively. Nonesterified fatty acid concentration decreased quadratically (P<0.05) with the SH inclusion, with values of 0.323, 0.244, 0.204, and 0.216 mequiv./l for the SHO, SH33, SH67, and SH100 treatments being recorded, respectively. Replacement of the NDF provided by coastcross hay with the NDF from the SH did not influence the duration of the postpartum anestrous period in Santa Ines lactating ewes. Considering a 150-day gestation period and the 34 days postpartum anestrous demonstrated in the present study, the current production system of a lambing interval of 8 months (3 lambing events in 2 years) may not be optimizing the production potential and a system in which the lambing interval is shortened by at least 1 month may be feasible. (C) 2008 Elsevier B.V. All rights reserved.

Transplacental Transfer of Iron in the Water Buffalo (Bubalus bubalis): Uteroferrin and Erythrophagocytosis

The objectives of this investigation were to understand transplacental transport of iron by secreted uteroferrin (UF) and haemophagous areas of water buffalo placenta and clarify the role(s) of blood extravasation at the placental-maternal interface. Placentomes and interplacentomal region of 51 placentae at various stages of gestation were fixed, processed for light and transmission electron microscopy, histochemistry and immunohistochemistry. Haemophagous areas were present in placentomes collected between 4 and 10 months of pregnancy. Perl`s reaction for ferric iron was negative in placentomes, but positive in endometrial glands. Positive staining for UF indicated areas in which it was being taken up by phagocytosis and/or fluid phase pinocytosis in areolae of the interplacentomal mesenchyme, with little staining in endometrial stroma. Imunohistochemistry detected UF in trophectoderm of haemophagous regions of placentomes and in other parts of the foetal villous tree, but the strongest immunostaining was in the epithelial cells and lumen of uterine glands. Ultrastructural analyses indicated that erythrophagocytosis was occurring and that erythrocytes were present inside cells of the chorion that also contained endocytic vesicles and caveolae. Results of this study indicate that both the haemophagous areas of placentomes and the areolae at the interface between chorion and endometrial glands are important sites for iron transfer from mother to foetal-placental tissues in buffalo throughout pregnancy.

In vitro analysis of inhibitory effects of the antibacterial monomer MDPB-containing restorations on the progression of secondary root caries

Objective: This study aimed to analyze in vitro inhibitory effects of restorative materials containing the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) on the formation of artificial secondary root caries lesions. Methods: Class V cavities (2 mm x 2 mm) were prepared in 75 human root fragments. Specimens were randomly divided into five groups (n = 15 fragments per group) and restored as follows: (I) MDPB-free adhesive system + MDPB-free composite (negative control); (II) resin modified glass ionomer (RM-GIC; positive control); (III) MDPB-free adhesive system + MDPB-containing composite (2.83% MDPB); (IV) MDPB-containing adhesive system + MDPB-free composite; M MDPB-containing adhesive system + MDPB-containing composite. Artificial secondary root caries lesions were produced by a biological artificial caries challenge. The restored specimens were immersed into a culture medium containing Streptococcus mutans and sucrose for 15 days. Histological slices (80 +/- 20 mu m) of the specimens were used for measuring the mean depths of the artificial lesions produced in both margins of the restorations using polarized light microscopy. Results were expressed in percentage related to the mean depth of the negative control, considered 100%. Data were compared by ANOVA followed by the Tukey`s test (p <= 0.05). Results: The depths of lesions adjacent to cavities filled with RM-GIC (GII; 85.17 +/- 15.2%) were significantly (p < 0.01) shallower than those adjacent to restorations with MDPB-free composite (GI; 100.00 +/- 10.04%), despite the presence of MDPB in the adhesive system (GIV; 101.95 +/- 21.32%). The depths of lesions adjacent to cavities restored with MDPB-containing composite (GIII; 82.68 +/- 12.81% and GV; 85.65 +/- 15.42%), despite the adhesive system used, were similar to those of RM-GIC (GII). Mean lesions depths in these groups decreased from 13% (GV) to 17% (GIII) in relation to the negative control (GI). Conclusions: MDPB-containing composite inhibits the progression of artificial secondary root caries lesions regardless of adhesive systems. (C) 2009 Elsevier Ltd. All rights reserved.

Gels Containing MMP Inhibitors Prevent Dental Erosion in situ

Matrix metalloproteinase (MMP) inhibition has been shown to reduce dentin caries progression, but its role in dental erosion has not yet been assessed. This study tested the hypothesis that gels containing MMP inhibitors (epigallocatechin gallate-EGCG and chlorhexidine) can prevent dental erosion. Volunteers (n = 10) wore palatal devices containing bovine dentin blocks (n = 10/group) treated for 1 min with EGCG at 10 (EGCG10) or 400 mu M (EGCG400), chlorhexidine at 0.012%, F at 1.23% (NaF), and no vehicle (placebo). Erosion was performed with Coca-Cola (R) (5 min) 4X/day during 5 days. The wear, assessed by profilometry (mean +/- SD, mu m), was significantly reduced by the gels containing MMP inhibitors (0.05 +/- 0.02(a), 0.04 +/- 0.02(a), and 0.05 +/- 0.02(a) for EGCG10, EGCG400, and chlorhexidine, respectively) when compared with NaF (0.79 +/- 0.35(b)) and placebo gels (1.77 +/- 0.35(b)) (Friedman and Dunn`s tests, p < 0.01). The use of gels delivering MMP inhibitors was shown to prevent erosion and opens a new perspective for protection against dental erosion.

Preventive Effect of Commercial Desensitizing Toothpastes on Bovine Enamel Erosion in vitro

This study evaluated in vitro commercial desensitizing toothpastes with respect to the prevention of erosion and explored the effect of their agents alone or in combination with fluoride. Bovine enamel blocks were randomly allocated to five groups of 20 and exposed to: Sensodyne ProNamel (1,425 ppm F as NaF, 5% KNO(3)), Sensodyne Original (no fluoride, 10% SrCl(2)), Colgate Sensitive (1,450 ppm F as sodium monofluorophosphate, 5% K citrate), Crest (fluoride-only toothpaste, 1,100 ppm F as NaF) and water (negative control). A second experiment was conducted with experimental dentifrices containing fluoride (NaF, 1,100 ppm F), 10% SrCl(2), 5% KNO(3) or 5% K citrate alone or the latter three combined with F. The samples were submitted to four cycles, alternating demineralization (cola, 10 min) and remineralization (artificial saliva, 1 h). Before and between cyclic de- and remineralization, blocks were treated with slurries of the respective toothpastes or water (1 min). Erosive tissue loss was analyzed by profilometry. Data were analyzed by Kruskal-Wallis and Dunn`s tests (p < 0.05). The mean erosion depth (+/- SE, mu m) was significantly less for Colgate Sensitive (0.04 +/- 0.00), Sensodyne Original (0.06 +/- 0.01) and Crest (0.07 +/- 0.01) than for Sensodyne ProNamel (2.36 +/- 0.25) or water (2.92 +/- 0.24), which did not significantly differ from each other. Both F and the desensitizing agents alone reduced erosion, but no additive effect was found. In addition, the combination of F and KNO(3) did not reduce erosion. These in vitro results suggest that the presence of fluoride or desensitizing substances in toothpastes, alone or in combination, can reduce erosion of enamel, but this is not valid for all the formulations. Copyright (C) 2010 S. Karger AG, Basel

Effect of ion supplementation of a commercial soft drink on tooth enamel erosion

Acidic soft drinks are potentially erosive for dental hard tissues. This in vitro study evaluated the effect of calcium, fluoride, iron and phosphate, supplemented alone or in combination to a commercial citric acid-based carbonated beverage on dental erosion. Ninety enamel samples (4 x 4 x 3 mm) were randomly allocated to nine groups (n = 10): G1 - pure beverage (control); G2 - with 1 mM Ca; G3 - with 0.047 mM F; G4 - with 1 mM Fe; G5 - with 1 mM P; G6 - with 1 mM Ca and 0.047 mM F; G7 - with 1 mM Ca and 1 mM P; G8 - with 1 mM Fe and 0.047 mM F; and G9 - with 1 mM Ca, 1 mM P, 0.047 mM F and 1.0 mM Fe. The samples were subjected to six pH cycles over a 24-h period. In each cycle, the samples were immersed in pure or modified beverage (1 min) and in artificial saliva (59 min). During the remaining period (18 h), the samples were maintained in artificial saliva. Enamel loss was assessed by profilometry (mm). Data were tested using ANOVA and Tukey`s tests (p < 0.05). Highest enamel losses were observed in the control group (G1) and in the groups containing Fe (G4 and G8). The groups containing Ca (G2 and G6) showed significantly less wear compared to control. In conclusion, the modification of an erosive soft drink with low concentrations of Ca with or without F may reduced its erosive potential.

Evaluation of pH and Calcium Ion Release of Root-end Filling Materials Containing Calcium Hydroxide or Mineral Trioxide Aggregate

Introduction: To evaluate calcium ion release and pH of Sealer 26 (S26) (Dentsply, Rio de Janeiro, RJ, Brazil), white mineral trioxide aggregate (MTA), Endo CPM Sealer (CPM1) (EGEO SRL Bajo licencia MTM Argentina SA, Buenos Aires, Argentina), Endo CPM Sealer in a thicker consistency (CPM 2), and zinc oxide and eugenol cement (ZOE). Methods: Material samples (n = 10) were placed in polyethylene tubes and immersed in 10 mL of distilled water. After 3, 6,12,24, and 48 hours and 7,14, and 28 days, the water pH was determined with a pH meter, and calcium release was assessed by atomic absorption spectrophotometry. An empty tube was used as the control group. Results: The control group presented a pH value of 6.9 at all studied periods and did not show the presence of calcium ion. S26 presented greater hydroxyl ion release up to 12 hours (p < 0.05). From 24 hours until 28 days, S26, MTA, CPM1, and CPM2 had similar results. in ail periods, ZOE presented the lowest hydroxyl ion release. CPM1, followed by CPM2, released the most calcium ions until 24 hours (p < 0.05). Between 48 hours and 7 days, CPM1 and CPM2 had the highest release. A greater calcium ion release was observed for CPM2, followed by CPM1 at 14 days and for S26, CPM1, and CPM2 at 28 days. ZOE released the least calcium ions in all periods. Conclusion: Sealer 26, MTA, and Endo CPM sealer at normal or thicker consistency release hydroxyl and calcium ions. Endo CPM sealer may be an alternative as root-end filling material. (J Endod 2009;35:1418-1421)

In vitro wear, surface roughness and hardness of propanal-containing and diacetyl-containing novel composites and copolymers based on bis-GMA analogs

Objective. To evaluate the effect of two additives, aldehyde or diketone, on the wear, roughness and hardness of bis-GMA-based composites/copolymers containing TEGDMA, propoxylated bis-GMA (CH(3)bis-GMA) or propoxylated fluorinated bis-GMA (CF(3)bis-GMA). Methods. Fifteen experimental composites and 15 corresponding copolymers were prepared combining bis-GMA and TEGDMA, CH3bis-GMA or CF3bis-GMA, with aldehyde (24mol% and 32 mol%) or diketone (24 mol% and 32 mol%) totaling 30 groups. For composites, hybrid treated filler (barium aluminosilicate glass/pyrogenic silica; 60 wt%) was added to monomer mixtures. Photopolymerization was affected by 0.2 wt% each of camphorquinone and N,N-dimethyl-p-toluidine. Wear (W) test was conducted in a toothbrushing abrasion machine (n = 6) and quantified using a profilometer. Surface roughness (R) changes, before and after abrasion test, were determined using a rugosimeter. Microhardness (H) measurements were performed for dry and wet samples using a Knoop microindenter (n = 6). Data were analyzed by one-way ANOVA and Tukey`s test (alpha = 0.05). Results. Incorporation of additives led to improved W and H values for bis-GMA/TEGDMA and bis-GMA/CH(3)bis-GMA systems. Additives had no significant effect on the W and H changes of bis-GMA/CF(3)bis-GMA. With regard to R changes, additives produced decreased values for bis-GMA/CH3bis-GMA and bis-GMA/CF3bis-GMA composites. Bis-GMA/TEGDMA and bis-GMA/CH(3)bis-GMA copolymers with additives became smoother after abrasion test. Significance. The findings correlate with additives ability to improve degree of conversion of some composites/copolymers thereby enhancing mechanical properties. Published by Elsevier Ltd on behalf of Academy of Dental Materials

Evaluation of pH and Calcium Ion Release of Calcium Hydroxide Pastes Containing Different Substances

Introduction: The objective of this study was to evaluate the pH and calcium ion release of calcium hydroxide pastes associated with different substances. Methods: Forty acrylic teeth with simulated root canals were divided into 4 groups according to the substance associated to the calcium hydroxide paste: chlorhexidine (CHX) in 2 formulations (1% solution and 2% gel), Casearia sylvestris Sw extract, and propylene glycol (control). The teeth with pastes and sealed coronal accesses were immersed in 10 mL deionized water. After 10 minutes, 24 hours, 48 hours, and 7, 15, and 30 days, the teeth were removed to another container, and the liquid was analyzed. Calcium ion release was measured by atomic absorption spectrophotometry, and pH readings were made with a pH meter. Data were analyzed statistically by analysis of variance and Tukey test (alpha = 0.05). Results: Calcium analysis revealed significant differences (P < .05) for 1% CHX solution and 2% CHX gel at 10 minutes. After 24 hours, 2% CHX gel x Control and 2% CHX gel x 1% CHX solution differed significantly (P < .05). After 48 hours, there were significant differences (P < .05) for 2% CHX gel x Control and Extract x Control. No differences (P > .05) were observed among groups in the other periods. Regarding the pH, there were significant differences (P < .05) for 2% CHX gel x Control and 2% CHX gel x 1% CHX solution after 48 hours and for 2% CHX gel x Control after 15 days. In the other periods, no differences (P > .05) were observed among groups. Conclusions: All pastes behaved similarly in terms of pH and calcium ion release in the studied periods. (J Endod 2009;35:1274-1277)

Should we measure serum or plasma lead concentrations?

Project: Serum samples may not be appropriate to assess lead (Pb) concentrations because they may contain artificially higher Pb concentrations compared with those measured in plasma samples. Here, we compared Pb concentrations in serum versus heparin plasma separated from blood collected with or without vacuum. We have also examined the effects of sample standing time on Pb concentrations measured in serum, heparin plasma, and EDTA plasma. Procedure: We studied plasma and serum samples from twelve healthy subjects. Blood samples were collected via venous drainage phlebotomy with and without vacuum into trace metal free tubes containing no anticoagulants (serum), or lithium heparin, or EDTA (to obtain plasma). Variable sample standing times (0, 5, and 30 min) prior to centrifugation were allowed. Plasma and serum Pb and iron concentrations were determined by inductively coupled plasma mass spectrometry. Plasma and serum cell-free hemoglobin concentrations were measured. Results: Pb concentrations in serum and in heparin plasma from blood samples collected with or without vacuum were similar and not associated with significant changes in iron or hemoglobin concentrations. The sample standing time (up to 30 min) did not affect Pb concentrations in serum or in heparin plasma, which were approximately 50% lower than those found in EDTA plasma. Conclusions: Serum or heparin plasma separated from blood samples collected via venous phlebotomy with or without vacuum are appropriate medium to assess Pb concentrations, independently of the sample standing time. (C) 2010 Elsevier GmbH. All rights reserved.

Potential effect of sodium bicarbonate-containing dentifrice in controlling enamel erosion in situ

Purpose: To assess, by a crossover 2 x 2 in situ study, the speculated protective role of a sodium bicarbonate-containing toothpaste in controlling erosive lesions. Methods: Bovine enamel slabs were sterilized, and submitted to baseline Knoop microhardness measurements. After a 3-day lead-in period, 14 volunteers wore palatal acrylic appliances containing six enamel slabs (three on each side), for 4 consecutive days. On the first day, appliances with contained specimens were placed in the oral cavity to allow salivary pellicle formation. On the subsequent days, half of the enamel slabs were immersed extraorally in a lemonade-like soft drink for 90 seconds, twice daily. On both of these occasions, the appliance was dipped in toothpaste slurry of either a sodium bicarbonate-containing toothpaste or a regular counterpart for 60 seconds. Following a 3-day washout period, a new set of enamel slabs were mounted and the volunteers started the second period using the alternate dentifrice. Results: ANOVA (alpha = 0.05) showed no statistically significant difference between enamel treated with regular and sodium bicarbonate-based dentifrices, regardless of whether specimens were eroded or not (P=0.8430). Acid-challenged specimens revealed lower microhardness values than uneroded samples. (Am J Dent 2008;21:300-302).