Le(a-b-) phenotype: potential risk factor for infection by the RH strain of Toxoplasma gondii in pregnancy

The Lewis histo-blood group system is characterized by the expression of the Lea and Le(b) antigens in the gastrointestinal tract, whose synthesis results in interactions between alpha 2-L-fucosyltransferase (FUTII) and alpha 3/4-L-fucosyltransferase (FUTIII) enzymes coded by the FUT2 (19q. 13.3) and FUT3 (19p13.3) genes. FUTII and FUTIII fucosylate the type 1 oligosaccharide precursor (Gal beta 1 -> 3NAcGlc beta 1 -> 3-R) at distinct positions to form H type 1 (Fuc alpha 1. 2Gal beta 1. 3NAcGlc beta 1 -> 3-R) and Le(a) (Gal beta 1 -> 3[Fuc alpha 1 -> 4] NAcGlc beta 1 -> 3-R) antigens, respectively. The fucosylation of H type 1 antigens by FUTIII results in the Leb antigen (Fuc alpha 1. 2Gal beta 1. 3[Fuca1. 4] NAcGlc beta 1. 3-R). Thus, the presence of the FUTII and FUTIII enzymes leads to the expression of the Le(a+b+) phenotype, while the presence of only FUTIII allows the expression of the Le(a+b-) phenotype. The absence of the FUTIII enzyme leads to the expression of the Le(a-b-) phenotype, independent of the presence or absence of FUTII. Point mutations in FUT2 and FUT3 genes change the activity of these enzymes, impair the synthesis of Le(a) and Le(b) antigens, and contribute to the variability of Lewis phenotypes in the gastrointestinal tract. Toxoplasma gondii, an apicomplexan parasite that infects a large proportion of the world's population, utilizes the gastrointestinal tract as an infection route and seems to adhere to glycosylated molecules to invade human cells. These apparently independent events may be related. The aim of this study was to test the hypothesis that there is an association between the Lewis histo-blood group system and infection by T. gondii. Two hundred and nine serum samples collected from pregnant women were submitted to screening tests to detect anti-T. gondii antibodies, employing the indirect hemagglutination method. ELISA was utilized to identify IgG class anti-T. gondii antibodies specific for the RH strain. A hundred and ninety-five samples with concordant results for both methods were selected to form two groups: seropositive (G1) and seronegative (G2). The G428A mutation of the FUT2 gene, and T202C and C314T of the FUT3 gene, which allow inference of the gastrointestinal tract Lewis phenotypes, were identified using PCR-RFLP and PCR-SSP methods, respectively. Among the 195 samples selected, 116 (59.5%) were seropositive and 79 (40.5%) were seronegative. In G1, 68 (58.6%) were classified as Le(a+b+), 30 (25.9%) as Le(a+b-), and 18 (15.5%) as Le(a-b-), and in G2, 67 (84.8%) were classified as Le(a+b+), 12 (15.2%) as Le(a+b-), and 0 (0%) as Le(a-b-) (P < 0.0001). The Le(a-b-) phenotype is associated with a high risk of RH strain T. gondii infection when compared with the Le(a+b+) [P = 0.0001; OR = 36,460; 95%CI = 2.152-617,680] and Le(a+b-) phenotypes [P = 0.0118; OR = 15,165; 95%CI = 0.8463-271,710]. The Le(a+b-) phenotype showed a higher risk compared to the Le(a+b+) phenotype [P = 0.0206; OR = 2463; 95%CI = 2463-5214]. The results suggest that the Le(a-b-) phenotype is strongly associated with a greater risk of infection by the RH strain of T. gondii compared to the other phenotypes. It is possible that the absence of fucosylation of the type 1 oligosaccharide precursor as well as the variations in the structures of the Le(a) and Le(b) antigens influence susceptibility to infection by this parasite.

Developmental aspects of early pregnancy in mares

In mares, the embryo migrates to the uterus between days 5 and 6 postovulation beginning its mobility through all uterine segments, which is essential for the maternal recognition of pregnancy. During the mobility phase, the embryonic vesicle shows a linear growth rate until its fixation between days 15 and 17, when the orientation phenomenon occurs. From fixation to day 28 of pregnancy, the embryonic growth is less evident (plateau) by cross-section ultrasound examination. After this period the linear growth rate is reestablished until day 46. This plateau is attributed to the increased uterine tone that compresses the vesicle and to volume expansion, making it difficult to detect the conceptus growth only by the cross-section diameter. Around day 20, the embryo proper is visualized as an echogenic spot in the ventral aspect of the vesicle. Additionally, development of allantoic sac, embryonic heartbeat, yolk sac regression and posterior umbilical cord formation also can be visualized from days 20 to 40. An intimate interaction between uterus and conceptus is essential for the normal pregnancy development. Color-and spectral-Doppler ultrasonography can be useful for the evaluation of this interface. A gradual increase on uterine vascularity during the early pregnancy and transient changes in endometrial vascularity accompanying the vesicle location during the mobility phase have been described. Around day 38 of gestation, the formation of the endometrial cups begins and, consequently, the synthesis of the equine chorionic gonadotropin (eCG) induces the formation and development of supplementary corpora lutea, which are important to secrete progesterone and to maintain pregnancy until around day 120.

Doppler ultrasound in pregnancy assessment in bitches - literature review

Doppler ultrasound enables the assessment of blood flow in real time and has been widely used to aid in pregnancy diagnosis and monitoring in dogs and cats. This technique has a diferencial when compared with the B-mode ultrasound, as it allows the evaluation of vascular hemodynamic characteristics, while the two-dimensional ultrasound allows the diagnosis of pregnancy and fetal viability. Thus, the objective of this review is to describe how circulation is characterized in the uterine and fetal arteries in bitches during pregnancy using Doppler ultrasonography.

Comparative study of ultrasonographic methods for assessment of pregnancy age in bitches

Compared with human beings, the application of ultrasound in estimating fetal age in bitches is limited due to the large variation of breed and size in this species. Several formulas were developed to calculate the gestational age and to provide the date of birth in dogs, but the efficacy of these formulas on the different gestational stages and dog breeds is unknown. The aim of this study was to compare sonographic methods for assessment of gestational age and days before parturition in dogs with different body weights and pregnancy stages. Twenty seven bitches of several sizes were examined and divided into three groups according to the initial body weight (A: <10kg; B: 10.1 - 20kg; C: >20.1kg); then each group was divided into three subgroups according to pregnancy stage (1st: 18 to 30 days; 2nd: 31 to 40 days; 3rd: >40 days) estimated according to the first day of copulation. Ultrasonography was performed weekly from the first stage of pregnancy. In the first and second stage the following formulas were applied: GA = (6XGSD) + 20; DBP = 65 - IG; by Nyland & Matton (2002); GA: gestational age; DBP: days before parturition; DSG: gestational sac diameter; in the third stage: DBP = 61,2 - (24,6 X BD); DBP = 43,5 - (10,9 X CD); by Burk & Ackerman (1996); BD: biparietal diameter; CD: body diameter, and: GA = (15 X BD) + 20; GA = (7 X CD) + 29; GA = (6 X BD) + (3 X CD) + 30; DBP = 65 - GA; by Nyland & Matton (2002). Results were compared statistically. The equations proposed by Nyland & Matton (2002), were more accurate in all pregnancy stages, with a margin of error of only three days, regardless of the size of the animal; therefore these methods are the best option in veterinary practice.

Data collection on bone density of mandibular alveolar bone on a Hounsfield scale of the dental apex of the cranial root of the first inferior molar in dogs using computed tomography at FMVZ-UNESP

The head is the most important and specialized region in the body because it contains a range of specialized organs and, because it has interconnections between specialized organs, there is a great overlap of images. Thus, computed tomography (CT) helps in diagnosing diseases in this region, such as oral conditions, as they provide millimetric slices or cuts and demonstrate the relationship between the various anatomical structures involved, in volume and depth. Within dentistry, CT helps in the identification of pathological processes such as infection, tumors, visualization of embedded teeth and bone bed. This study aimed to assess the density of the mandibular alveolar bone at a determined point to later predict how periodontal disease is involved in bone resorption. For this, we performed a blind retrospective study (n = 124) of the CT scan files of dog skulls at FMVZ-UNESP in order to determine the density of the jaw bone using a Hounsfield scale, in the region of the dental apex of the cranial root of the first molar tooth in dogs. The results obtained were evaluated using mean and standard deviation (27.28 +/- 9.53 HU) in order to predict the normal density of the mandibular alveolar bone in the studied region. Thus, this data analysis allows a more concise evaluation of bone resorption of mandibular alveolar bone and, therefore, provides an adequate surgical planning in cases of osteosynthesis given mainly by the presence of installed periodontal disease.

Abordaje conservador y mínimamente invasivo de la hipomineralización molar-incisivo (HMI) - Relato de casos clínicos

Molar-Incisor Hypomineralization (MIH) is a qualitative developmental enamel defect that affects one to four permanent first molars, with or without involvement of permanent incisors. Enamel defects may produce many symptoms that have physical, social and psychological effects and influence day-to-day living or quality of life. The available treatment modalities for teeth with MIH are extensive, ranging from prevention, restoration, to extraction. Factors such as age, patient expectations, severity of the lesion and materials should be considered in the treatment of the patient with MIH. Restoration with composite resin is an alternative choice for posterior and anterior MIH defective teeth and its use has been show acceptable results. This article describes two clinical cases involving pediatric patients with MIH whose procedure of cavity preparation was based on the use of CVD ultrasound diamond tips and restored using composite resin obtaining favorable esthetics results after a 1 year follow-up.

Manifestation of molar-incisor hypomineralisation in twins: clinical case reports

Molar-incisor hypomineralisation is a qualitative defect of dental tissue of systemic origin affecting one or more permanent first molars and sometimes the permanent incisors as well. There are still no conclusive data on the aetiology of this hypomineralisation, however, systemic factors such as respiratory diseases and prenatal and perinatal complications are regarded as possible causes. The objective is to present three clinical cases of twins, one Monozygotic and two Dizygotic Twins with molar-incisor hypomineralisation, showing evidence of its manifestation as well as clinical the characteristics and aetiological factors involved. The clinical findings involving twins suggest that ameloblasts are specifically affected in their developmental phase, which includes a number of factors. Although prenatal and perinatal complications are not decisive in the development of molar-incisor hypomineralization, it is suggested a possible genetic susceptibility to the disease. Prospective observational studies using a population sample containing data on the last three months of gestation to the eruption of permanent teeth are needed to confirm the causeeffect relationships.

Bone stress and strain after use of a miniplate for molar protraction and uprighting: a 3-dimensional finite element analysis

The aim of this study was to use the finite element method to evaluate the distribution of stresses and strains on the local bone tissue adjacent to the miniplate used for anchorage of orthodontic forces. Methods: A 3-dimensional model composed of a hemimandible and teeth was constructed using dental computed tomographic images, in which we assembled a miniplate with fixation screws. The uprighting and mesial movements of the mandibular second molar that was anchored with the miniplate were simulated. The miniplate was loaded with horizontal forces of 2, 5, and 15 N. A moment of 11.77 N.mm was also applied. The stress and strain distributions were analyzed, and their correlations with the bone remodeling criteria and miniplate stability were assessed. Results: When orthodontic loads were applied, peak bone strain remained within the range of bone homeostasis (100-1500 mu m strain) with a balance between bone formation and resorption. The maximum deformation was found to be 1035 mu m strain with a force of 5 N. At a force of 15 N, bone resorption was observed in the region of the screws. Conclusions: We observed more stress concentration around the screws than in the cancellous bone. The levels of stress and strain increased when the force was increased but remained within physiologic levels. The anchorage system of miniplate and screws could withstand the orthodontic forces, which did not affect the stability of the miniplate.

An unusual case of severe primary molar infraocclusion

Dentoalveolar ankylosis is described as the direct union between root cementum/dentin and alveolar bone. Its etiology is unknown, and conflicting opinions have been presented to explain it. Late detection of ankylosed primary teeth may cause serious problems to the occlusion and generally demands a more complex treatment approach. The purpose of this report is to present an unusual case of severe infraocclusion of the primary maxillary right second molar associated with a posterior crossbite in a 6-year-old child. The initial treatment option was tooth extraction, but the tooth resumed eruption spontaneously. After correction of the posterior crossbite and a 1-year follow-up, the tooth remained in occlusion and the permanent successor was developing without problems. From this unusual outcome, it may be concluded that further investigation of this anomaly of eruption is needed. (J Dent Child 2013;80(2):88-91)

Maxillary molar intrusion with zygomatic anchorage in open bite treatment: lateral and oblique cephalometric evaluation

Purpose We aimed to use lateral and oblique radiographs to evaluate dental and skeletal changes arising from maxillary molar intrusion with zygomatic anchorage in open bite patients. Methods We conducted a pilot study including nine patients (six females and three males; mean age, 18.7±5.1 years) with skeletal open bite treated with titanium miniplates for posterior dentoalveolar intrusion. Lateral and oblique (right and left, 45°) radiographs were obtained before (T1) and 6 months after intrusion (T2). A paired t test was used for statistical evaluation. Results The maxillary posterior teeth were intruded 2.03± 0.87 mm (p<0.01) with 450×g of force, which resulted in counterclockwise rotation of the mandible (1.57°, p=0.02) and clockwise rotation of the occlusal plane (4.27±2.66°, p=0.01). Anterior facial height decreased by a mean of 1.79±1.51 mm (p<0.01). No significant change in the palatal plane or in anteroposterior molar movement was observed. Conclusion The oblique radiograph at 45° was useful for the assessment of molar intrusion and anteroposterior displacement. The treatment of anterior open bite with skeletal anchorage provided intrusion of molars and counterclockwise rotation of the mandible, resulting in open bite closure.

Dimensões do corredor bucal e sua relação com a distância inter pré-molar e intercomissural

The objective of the study was to analyze the size of buccal corridor during the smile of individuals from 10 to 19 years of age and to determine whether there is a relationship among buccal corridor, inter premolar distance, inter commissure width. Standard digital frontal photographs in posed broad smiles and dental casts were taken of a sample of 150 individuals divided into 5 age groups of 30 individuals: 10-11 years old (G1), 12-13 years old (G2), 14-15 years old (G3), 16-17 years old (G4), 18-19 years old (G5). Distances among the cusps of superior first premolars and buccal corridors were measured for subsequent comparisons using the Image Tool 3.0 program. Data was analyzed using Anova. The SNK test and Tamhane test were applied. The mean values of the buccal corridor ranged from 4.00-to 10.69 mm on the right side and from 4.06 to 11.43 mm on the left side. In percentage related with intercomissure width each side of the buccal corridor ranged from 7.46 to 16.47% on the right side and from 7.58% to 17.61% on the left side. Buccal corridors were different between genders and increased with age. Males have bigger buccal corridors than females, but there is no difference between gender when calculated as a percentage related with the inter commissure width. The inter premolar width is significantly correlated with inter commissure widths of female individuals 14-15 years old and 18-19 years old, and with the right linear buccal corridor of males and females aged 14-15 years old.

Hipomineralização Molar Incisivo (HMI): avaliação clínica e microscópica

This study aimed to evaluate the clinical and microscopic changes of MIH, and compare them to areas of healthy dental enamel. Methodology: epoxy resin replicas of healthy incisors and affected by MIH were evaluated qualitatively by scanning electron microscopy (SEM) photographs. Results: Clinically it was observed that MIH incisors showed changes in color and surface, with significant structural losses. By SEM, these had irregular surfaces and margins with structural losses. Conclusions: The teeth affected by HMI have clinical and morphological characteristics that are important for the definition of patient's treatment plan.

Influence of the rotary and/or oscillatory reciprocating systems in the morphological changes of narrow and curved molar root canals anatomy

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ultrasonography of the conceptus development from days 15 to 60 of pregnancy in non-cyclic recipient mares

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)