Ectopic eruption of the second premolar: an analysis of four different treatment approaches.

PURPOSE: Ectopic second premolars may lead to impaction and loss of space in the jaws, and in rare cases even to resorption of the first permanent molar. The aim of this study was to analyse different treatment strategies of ectopic second premolars and if possible give guidelines on when to favour different treatment approaches. MATERIALS AND METHODS: The study was a retrospective, non-randomised, outcome analysis of treatment on 41 ectopic second premolars in 37 patients (24 females and 13 males). In all cases oral examination, radiographs (pre-, peri-, and post) and full medical history were obtained. The treatment options included: (a) spontaneous eruption, (b) spontaneous eruption + extraction of primary tooth, (c) surgical exposure, (d) surgical uprighting, and (e) surgical uprighting + orthodontic extrusion. For evaluation each tooth was scored according to: (1) stage of root development, (2) distance between edges of the premolar and first permanent molar, (3) depth of impaction, (4) inclination, (5) horizontal position of the tooth. The level of significance was set to 5%. RESULTS: Only mild cases of ectopic second premolars are self-correcting. Based on the position of the tooth in the jaw different treatment options may be chosen, these may include: extraction of primary predecessor (impaction depth < 5 mm, inclination < 55°), surgical exposure of tooth germ (impaction depth < 5.5 mm, inclination < 95°) or surgical uprighting (impaction depth > 5.5 mm with no inclination limit). CONCLUSION: If there is no sign of self-correction after a short observation period, it is important to consider active treatment to help guiding the tooth into the correct eruption pathway.

Localised scleroderma en coup de sabre affecting the skin, dentition and bone tissue within craniofacial neural crest fields. Clinical and radiographic study of six patients.

PURPOSE: When localised scleroderma occurs in the face, neck and scalp area, it is called scleroderma en coup de sabre (SCS) for its resemblance to the stroke of a sabre. Most observed characteristics: abnormal skin and dental development, facial atrophy and neurological complications. The aim was to evaluate the extent of SCS in the underlying subcutis, including teeth/bone tissues. The goal was to solve, how far the external visual skin abnormality extends in depth, and if the condition appears within and limited to craniofacial neural crest fields. METHODS: Photographic and radiographic materials from six patients (one male, five females, aged 5-39 years) were included. The cases were divided in three groups, two in each, according to similarity in location of SCS in the skin. Dentition and gingiva were analysed clinically and from intra-oral photos, dental radiographs and orthopantomograms. Agenesis, dental maturity stage (root length), deviation in crown and root morphology (size and shape), and eruption disturbances were registered. Profile and frontal radiographs were analysed cephalometrically for jaw relationships and bone structures. RESULTS: In SCS, skin affection corresponds to the neural crest regions/fields. A close spatial association between skin, teeth and bone affections within neural crest fields was found. No common traits in profile analyses were observed. Asymmetry from minor to severe appears in the frontal analyses. A malformation in planum sphenoidale was observed in two individuals with the same location of skin affections. CONCLUSION: SCS conditions seem to extend from the skin in the depth to the sella turcica area within neural crest fields.

Microstructural evolution during sintering of copper particles studied by laboratory diffraction contrast tomography (LabDCT).

Pressureless sintering of loose or compacted granular bodies at elevated temperature occurs by a combination of particle rearrangement, rotation, local deformation and diffusion, and grain growth. Understanding of how each of these processes contributes to the densification of a powder body is still immature. Here we report a fundamental study coupling the crystallographic imaging capability of laboratory diffraction contrast tomography (LabDCT) with conventional computed tomography (CT) in a time-lapse study. We are able to follow and differentiate these processes non-destructively and in three-dimensions during the sintering of a simple copper powder sample at 1050 °C. LabDCT quantifies particle rotation (to <0.05° accuracy) and grain growth while absorption CT simultaneously records the diffusion and deformation-related morphological changes of the sintering particles. We find that the rate of particle rotation is lowest for the more highly coordinated particles and decreases during sintering. Consequently, rotations are greater for surface breaking particles than for more highly coordinated interior ones. Both rolling (cooperative) and sliding particle rotations are observed. By tracking individual grains the grain growth/shrinkage kinetics during sintering are quantified grain by grain for the first time. Rapid, abnormal grain growth is observed for one grain while others either grow or are consumed more gradually.

Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy.

The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through '4D' in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-ß21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 µm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance.

RUNX2 analysis of Danish cleidocranial dysplasia families.

Cleidocranial dysplasia (CCD) is an autosomal dominant inherited disease caused by mutations in the Runt gene RUNX2. Screening of 19 Danish CCD families revealed 16 pathogenic mutations (84%) representing 8 missense mutations, 2 nonsense mutations, 4 frame-shift mutations and 2 large deletions in the RUNX2 locus. Eight mutations were novel, two were found twice, and polymorphisms were found in the promoter region and in the conserved polyglutamine/polyalanine repeat. A large duplication downstream of RUNX2 found in one patient suggests a possible regulatory RUNX2 element. The CCD phenotypes and genotypes adhere to the large phenotypic variability reported in previous CCD studies. Identification of large chromosome aberrations in or near the RUNX2 locus in 3 of the 19 cases suggests copy number analyses to be included in future RUNX2 mutation analyses.

Three-dimensional grain mapping by x-ray diffraction contrast tomography and the use of Friedel pairs in diffraction data analysis.

X-ray diffraction contrast tomography (DCT) is a technique for mapping grain shape and orientation in plastically undeformed polycrystals. In this paper, we describe a modified DCT data acquisition strategy which permits the incorporation of an innovative Friedel pair method for analyzing diffraction data. Diffraction spots are acquired during a 360 degrees rotation of the sample and are analyzed in terms of the Friedel pairs ((hkl) and (hkl) reflections, observed 180 degrees apart in rotation). The resulting increase in the accuracy with which the diffraction vectors are determined allows the use of improved algorithms for grain indexing (assigning diffraction spots to the grains from which they arise) and reconstruction. The accuracy of the resulting grain maps is quantified with reference to synchrotron microtomography data for a specimen made from a beta titanium system in which a second phase can be precipitated at grain boundaries, thereby revealing the grain shapes. The simple changes introduced to the DCT methodology are equally applicable to other variants of grain mapping.

Grain nucleation and growth during phase transformations.

The mechanical properties of polycrystalline materials are largely determined by the kinetics of the phase transformations during the production process. Progress in x-ray diffraction instrumentation at synchrotron sources has created an opportunity to study the transformation kinetics at the level of individual grains. Our measurements show that the activation energy for grain nucleation is at least two orders of magnitude smaller than that predicted by thermodynamic models. The observed growth curves of the newly formed grains confirm the parabolic growth model but also show three fundamentally different types of growth. Insight into the grain nucleation and growth mechanisms during phase transformations contributes to the development of materials with optimal mechanical properties.

The major selenium-containing protein in human peripheral granulocytes.

Previously, a selenium-containing protein with subunit molecular weight of 15 kDa was found in peripheral human granulocytes. In continuation of this work, the present communication accounts for purification, identification, and characterization of this major selenium-containing protein. The protein was purified on a heparin-Sepharose column followed by Sephacryl S-200 column chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis visualized two bands with subunit molecular weights around 15 kDa. o-Phthaldialdehyde precolumn derivatization and reverse-phase high-performance liquid chromatography showed that the protein contains selenocysteine or selenocystine residues. High-performance gel filtration and isoelectric focusing revealed that the protein had an apparent molecular weight of 32 kDa and a pI value of 7.9. The addition of the protein synthesis inhibitor puromycin to the cell culture medium decreased the 15-kDa protein synthesis. These data suggest that the major selenium-containing protein in peripheral human granulocytes might be a protein with two subunits around 15 kDa. Enzyme studies showed that the protein had peroxidase activity assayed with H2O2 as a substrate and O-dianisidine as a hydrogen donor. This enzymatic activity competed with glutathione peroxidase on the consumption of H2O2, leading to an "inhibiton" of glutathione peroxidase (GSH-Px) activity. Sodium azide could eliminate the inhibition of the protein to GSH-Px. All of the above results implicated that the protein might be a H2O2-dependent selenium containing peroxidase different from GSH-Px. Therefore, the biological function of the protein could be related to eliminating H2O2 generated in the respiratory burst reaction of granulocytes, thus protecting these cells from oxidative damage during phagocytosis.

[Referred morbidity and care seeking on mental disorders in childhood and adolescence]. / Morbidade referida e busca de ajuda nos transtornos mentais na infância e adolescência.

INTRODUCTION: Determining the prevalence of mental disturbances in childhood and adolescence gives us a better knowledge of their distribution in a given age group and provide us data for planning, implementing and evaluating health care programs. This survey was centered on complaints of "nervous problems" in a population group ranging from 1 to 19 years old as a tool to measure mental illness prevalence in that age group. METHODS: A group of 141 children and teenagers with complaints of nervous problems participated in the study, drawn by applying questionnaires from June, 1989 to July, 1990 to a sample of 3,158 people in the age group 1-19 years old, living in the Southeast area of Grande São Paulo. It was conducted an analysis of the nature of the complaints, their referred reasons and behavior, age, and gender. RESULTS: The prevalence of complaints of nervous problems was 4.7%. The older they were the more they complained. It was noticed a male predominance in the younger group and female preponderance in the group 14 years old or older. One in five tried to get any help, and severity of their complaint was the most important predictor for that. CONCLUSION: The prevalence was due to the population's ability to identify mental illnesses and it also reflects the family understandings of these problems. As only a few sought for health care, possible causes were identified and intervention actions were proposed to satisfy the unattended needs.

Different selenium-containing proteins in the extracellular and intracellular media of leucocytes cultivated in vitro.

The purpose of this communication is to elucidate if selenium plays a role in the function of granulocytes and lymphocytes. Thus, the incorporation of selenium in proteins from granulocytes and lymphocytes cultured with 1 microCi/mL radioactive Na2(75)SeO3 was studied. The protein peaks containing 75Se from two columns of Heparin Sepharose CL-6B and Sephacryl S-200 HR were separated further by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The results showed that the incorporation of 75Se into granulocytes was about six times higher than that of lymphocytes during a 96-h cultivation, however, the GSH-Px activity in granulocytes did not change significantly. On the other hand, the GSH-Px activity of lymphocytes rose significantly after three days cultivation. These data indicated that the main chemical form of selenium in granulocytes was not GSH-Px. Results from SDS-PAGE revealed a strongly 75Se-labeled protein band with subunit molecular weight of 15 kDa in the supernatant of granulocyte homogenate. However, the main chemical forms of selenium in the culture media of granulocytes and lymphocytes were found to be selenoprotein P. The different forms of selenium-containing proteins in the intracellular and extracellular media of granulocytes indicated the different functions of these proteins.

The uptake of Na-selenite in rat brain. Localization of new glutathione peroxidases in the rat brain.

Polyunsaturated fatty acids (PUFAs) occur in phospholipids of synapses of central nervous system (CNS). PUFAs may thus determine the fluidity of synaptosomal membranes and regulate neuronal transmission. It was therefore tempting to suggest an oxidative system in CNS protecting the membrane function, e.g., glutathione peroxidase (GSH-Px). In order to trace GSH-Px Wistar rats were loaded with 4800 kBq of 75Se sodium selenite. By means of gradient ultracentrifugation, particulate fractions of CNS were isolated and radioactivity as well as selenium dependent GSH-Px were estimated. The following data were obtained: 1. All fractions (myelin, synaptic vesicles, synaptosomes, mitochondria, and microsomes) contained 75Se. 2. After acetone precipitation of GSH-Px activity, fractionation on Sephadex G-150 revealed in all particulate fractions at least two peaks of radioactivity with GSH-Px activity. 3. The two GSH-Px peaks from the Sephadex filtration were freeze dried and applied on a hydrophobic T-gel column and eluted with decreasing molarity of ammonium sulfate from 1.5 to 0.05M. The first Sephadex peak with GSH-Px activity from myelin and the second peak with GSH-Px activity from synaptic vesicles could now be resolved into two different fractions of radioactivity on the T-gel. The remaining Sephadex G-150 peaks could only be resolved into one peak of radioactivity. 4. SDS-polyacrylamide gel electrophoresis of the T-gel peaks from all fractions showed a protein band with a mobility identical with that of human erythrocyte GSH-Px. The T-gel elution of myelin, synaptic vesicles and mitochondria gave rise to nearly pure CNS GSH-Px activity. The data presented support the idea that CNS fractions have membrane bound GSH-Px activity that may function as protecting enzymes towards oxidative stress in the brain.

Selenium-containing peroxidases of germinating barley.

Germinating barley grown on an artificial medium was exposed to 75Se-selenite for 8 d. Then the leaves were homogenized and proteins were separated by means of Sephadex G-150 filtration, followed by DEAE-Sepharose chromatography. Each fraction collected was assayed for total protein, radioactivity, and peroxidase activity. In barley leaves, three protein peaks (peaks no. I, II, and III) with peroxidase activity could be separated by Sephadex G 150 filtration. Each fraction was then further separated on DEAE-Sepharose chromatography. Thus, peaks I and II were resolved by DEAE-Sepharose into one major and two minor peaks of radioactivity. However, only the major peak showed peroxidase activity. Peak III was resolved from the gel filtration on the DEAE-sepharose into one major and four minor peaks of radioactivity. The major and three of the minor radioactivity peaks contained peroxidase activity. The protein fractions were separated by polyacrylamide gel electrophoresis. The molecular weights of separated proteins were estimated by means of molecular markers, and 75Se radioactivity was evaluated by autoradiography. Thus, gel filtration peak I contained four bands with mol wts of 128, 116, 100, and 89 kDa. Of these, the 89 kDa protein contained selenium. Peak II contained three protein bands with mol wts 79.4, 59.6, and 59.9. The 59.6 band was a selenoprotein. Peak III contained four protein bands (and some very weak bands). The four major bands had mol wts of 38.6, 31.6, 30.2, and 29.2 kDa. The last mentioned band was a selenoprotein.