Water excitation MPRAGE: An alternative sequence for postcontrast imaging of the abdomen in noncooperative patients at 1.5 Tesla and 3.0 Tesla MRI

Purpose: To evaluate the diagnostic image quality of post-gadolinium water excitation-magnetization-prepared rapid gradient-echo (WE-MPRAGE) sequence in abdominal examinations of noncooperative patients at 1.5 Tesla (T) and 3.0T MRI. Materials and Methods: Eighty-nine consecutive patients (48 males and 41 females; mean age +/- standard deviation, 54.6 +/- 16.6 years) who had MRI examinations including postgadolinium WE-MPRAGE were included in the study. Of 89 patients, 33 underwent noncooperative protocol at 1.5T. 10 under-went noncooperative protocol at 3.0T, and 46 underwent cooperative protocol at 3.0T. Postgadolinium WE-MPRAGE, MPRAGE, and three-dimensional gradient-echo sequences of these three different groups were qualitatively evaluated for image quality, extent of artifacts, lesion conspicuity, and homogeneity of fat-attenuation by two reviewers retrospectively, independently, and blindly. The results were compared using Wilcoxon signed rank and Mann-Whitney U tests. Kappa statistics were used to measure the extent of agreement between the reviewers. Results: The average scores indicated that the images were diagnostic for WE-MPRAGE at 1.5T and 3.0T in noncooperative patients. WE-MPRAGE achieved homogenous fat-attenuation in 31/33 (94%) of noncooperative patients at 1.5T and 10/10 (100%) of noncooperative patients at 3.0T. WE-MPRAGE at 3.0T had better results for image quality, extent of artifacts, lesion conspicuity and homogeneity of fat-attenuation compared with WE-MPRAGE at 1.5T. in noncooperative patients (P = 0.0008, 0.0006, 0.0024, and 0.0042: respectively). Kappa statistics varied between 0.76 and 1.00, representing good to excellent agreement. Conclusion: WE-MPRAGE may be used as a T1-weighted postgadolinium fat-attenuated sequence in noncooperative patients, particularly at 3.0T MRI.

Juvenile idiopathic arthritis with involvement of the temporomandibular joint: the role of image examinations

PURPOSE: Juvenile idiopathic arthritis (JIA) has unknown etiology, and the involvement of the temporomandibular joint (TMJ) is rare in the early phase of the disease. The present article describes the use of computed tomography (CT) and magnetic resonance (MRI) images for the diagnosis of affected TMJ in JIA. CASE DESCRIPTION: A 12-year-old, female, Caucasian patient, with systemic rheumathoid arthritis and involvement of multiple joints was referred to the Imaging Center for TMJ assessment. The patient reported TMJ pain and limited opening of the mouth. The helical CT examination of the TMJ region showed asymmetric mandibular condyles, erosion of the right condyle and osteophyte-like formation. The MRI examination showed erosion of the right mandibular condyle, osteophytes, displacement without reduction and disruption of the articular disc. CONCLUSION: The disorders of the TMJ as a consequence of JIA must be carefully assessed by modern imaging methods such as CT and MRI. CT is very useful for the evaluation of discrete bone changes, which are not identified by conventional radiographs in the early phase of JIA. MRI allows the evaluation of soft tissues, the identification of acute articular inflammation and the differentiation between pannus and synovial hypertrophy.

Timing and sequence of primary tooth eruption in children with cleft lip and palate

OBJECTIVE: To determine the timing and sequence of eruption of primary teeth in children with complete bilateral cleft lip and palate. MATERIAL AND METHODS: This cross-sectional study was conducted at the Hospital for Rehabilitation of Craniofacial Anomalies of the University of São Paulo, Bauru, SP, Brazil, with a sample of 395 children (128 girls and 267 boys) aged 0 to 48 months, with complete bilateral cleft lip and palate. RESULTS: Children with complete bilateral clefts presented a higher mean age of eruption of all primary teeth for both arches and both genders, compared to children without clefts. This difference was statistically signifcant for all teeth, except for the maxillary first molar. Mean age of eruption of most teeth was lower for girls compared to boys. The greatest delay was found for the maxillary lateral incisor, which was the eighth tooth of children with clefts of both genders. Analyzing by gender, the maxillary lateral incisor was the eighth tooth to erupt in girls and the last in boys. CONCLUSION: The results suggest an interference of the cleft on the timing and sequence of eruption of primary teeth.

The mitochondrial genome of the stingless bee Melipona bicolor (Hymenoptera, Apidae, Meliponini): sequence, gene organization and a unique tRNA translocation event conserved across the tribe Meliponini

At present a complete mtDNA sequence has been reported for only two hymenopterans, the Old World honey bee, Apis mellifera and the sawfly Perga condei. Among the bee group, the tribe Meliponini (stingless bees) has some distinction due to its Pantropical distribution, great number of species and large importance as main pollinators in several ecosystems, including the Brazilian rain forest. However few molecular studies have been conducted on this group of bees and few sequence data from mitochondrial genomes have been described. In this project, we PCR amplified and sequenced 78% of the mitochondrial genome of the stingless bee Melipona bicolor (Apidae, Meliponini). The sequenced region contains all of the 13 mitochondrial protein-coding genes, 18 of 22 tRNA genes, and both rRNA genes (one of them was partially sequenced). We also report the genome organization (gene content and order), gene translation, genetic code, and other molecular features, such as base frequencies, codon usage, gene initiation and termination. We compare these characteristics of M. bicolor to those of the mitochondrial genome of A. mellifera and other insects. A highly biased A+T content is a typical characteristic of the A. mellifera mitochondrial genome and it was even more extreme in that of M. bicolor. Length and compositional differences between M. bicolor and A. mellifera genes were detected and the gene order was compared. Eleven tRNA gene translocations were observed between these two species. This latter finding was surprising, considering the taxonomic proximity of these two bee tribes. The tRNA Lys gene translocation was investigated within Meliponini and showed high conservation across the Pantropical range of the tribe.

Imagem por ressonância magnética na investigação da cabeça de cães

A imagem por ressonância magnética (IRM) é o método de diagnóstico por imagem não invasivo mais sensível para avaliar as partes moles, particularmente o encéfalo, porém trata-se de uma técnica onerosa. O método fundamenta-se no fenômeno da ressonância magnética nuclear que ocorre quando núcleos atômicos com propriedades magnéticas presentes no corpo são submetidos a um campo magnético intenso, sendo posteriormente excitados por energia de radiofrequência e gerando, por sua vez, um sinal de onda de radiofrequência capaz de ser captado por uma antena receptora, passando por um processo matemático, chamado Transformada de Fourier, para posterior formação da imagem. Esse estudo objetivou realizar 10 exames completos da cabeça em cadáveres de cães normais à IRM e confeccionar um Atlas com as estruturas identificadas. As imagens foram adquiridas em um aparelho de ressonância magnética Gyroscan S15/HP Philips com campo magnético de 1,5Tesla. Os cadáveres foram posicionados com a cabeça no interior de uma bobina de cabeça humana e foram submetidos a cortes iniciais sagitais a partir de onde se planejou os cortes transversais e dorsais nas sequências de pulso spin-eco T1, T2 e DP. Em T1 utilizou-se TR=400ms e TE=30ms, T2 utilizou-se TR=2000ms e TE=80ms e na DP utilizou-se TR=2000ms e TE=30ms. A espessura do corte foi de 4mm, o número de médias foi igual a 2, a matriz foi de 256x256, o fator foi igual a 1,0 e o campo de visão foi de 14cm. A duração do exame completo da cabeça foi de 74,5minutos. As imagens obtidas com as sequências utilizadas e com a bobina de cabeça humana foram de boa qualidade. Em T1 a gordura tornou-se hiperintensa e o líquido hipointenso. Em T2 a gordura ficou menos hiperintensa e o líquido hiperintenso. A cortical óssea e o ar foram hipointensos em todas as sequências utilizadas devido a baixa densidade de prótons. A sequência DP mostrou o melhor contraste entre a substância branca e cinzenta quando comparada a T2 e a T1. T2 evidenciou o líquido cefalorraquidiano tornando possível a distinção dos sulcos e giros cerebrais. Através do exame de IRM foi possível, pelo contraste, identificar as estruturas ósseas componentes da arquitetura da região, músculos, grandes vasos venosos e arteriais e estruturas do sistema nervoso central, além de elementos do sistema digestório, respiratório e estruturas dos olhos entre outras. Nesse estudo as IRM adquiridas nas sequências T1, DP e T2 foram complementares para o estudo dos aspectos anatômicos da cabeça de cães demonstrando-os com riqueza de detalhes. O tempo requerido para o exame completo da cabeça é compátivel para uso em animais vivos desde que devidamente anestesiados e controlados. Os resultados obtidos por esse trabalho abrem caminho em nosso meio, para o estudo de animais vivos e para o início da investigação de doenças, principalmente as de origem neurológica, visto ser esta técnica excelente para a visibilização do encéfalo.

Evaluation of follicular lymphoid depletion in the Bursa of Fabricius: an alternative methodology using digital image analysis and artificial neural networks

Fifty Bursa of Fabricius (BF) were examined by conventional optical microscopy and digital images were acquired and processed using Matlab® 6.5 software. The Artificial Neuronal Network (ANN) was generated using Neuroshell® Classifier software and the optical and digital data were compared. The ANN was able to make a comparable classification of digital and optical scores. The use of ANN was able to classify correctly the majority of the follicles, reaching sensibility and specificity of 89% and 96%, respectively. When the follicles were scored and grouped in a binary fashion the sensibility increased to 90% and obtained the maximum value for the specificity of 92%. These results demonstrate that the use of digital image analysis and ANN is a useful tool for the pathological classification of the BF lymphoid depletion. In addition it provides objective results that allow measuring the dimension of the error in the diagnosis and classification therefore making comparison between databases feasible.

In silico analysis of Simple Sequence Repeats from chloroplast genomes of Solanaceae species

The availaibilty of chloroplast genome (cpDNA) sequences of Atropa belladonna, Nicotiana sylvestris, N tabacum, N tomentosiformis, Solanum bulbocastanum, S lycopersicum and S tuberosum, which are Solanaceae species, allowed us to analyze the organization of cpSSRs in their genic and intergenic regions In general, the number of cpSSRs in cpDNA ranged from 161 in S tuberosum to 226 in N tabacum, and the number of intergenic cpSSRs was higher than genic cpSSRs The mononucleotide repeats were the most frequent in studied species, but we also identified di-, tri-, tetra-, penta- and hexanucleotide repeats Multiple alignments of all cpSSRs sequence from Solanaceae species made the identification of nucleotide variability possible and the phylogeny was estimated by maximum parsimony Our study showed that the plastome database can be exploited for phylogenetic analyses and biotechnological approaches

Phylogenetic relationships in Solanaceae and related species based on cpDNA sequence from plastid trnE-trnT region

Intergenic spacers of chloroplast DNA (cpDNA) are very useful in phylogenetic and population genetic studies of plant species, to study their potential integration in phylogenetic analysis. The non-coding trnE-trnT intergenic spacer of cpDNA was analyzed to assess the nucleotide sequence polymorphism of 16 Solanaceae species and to estimate its ability to contribute to the resolution of phylogenetic studies of this group. Multiple alignments of DNA sequences of trnE-trnT intergenic spacer made the identification of nucleotide variability in this region possible and the phylogeny was estimated by maximum parsimony and rooted with Convolvulaceae Ipomoea batalas, the most closely related family. Besides, this intergenic spacer was tested for the phylogenetic ability to differentiate taxonomic levels. For this purpose, species from four other families were analyzed and compared with Solanaceae species. Results confirmed polymorphism in the trnE-trnT region at different taxonomic levels.

Long Terminal Repeat Sequence Analysis of HTLV-2 Molecular Variants Identified in Southern Brazil

In Brazil, human T-lymphotropic virus type 2 (HTLV-2) is endemic in Amerindians and epidemic in intravenous drug users (IDUs). The long terminal repeat (LTR) is the most divergent genomic region of HTLV-2, therefore useful to characterize subtypes. Nucleotide sequence and restriction fragment length polymorphism (RFLP) analysis of LTR genomic segments of fourteen HTLV-2 strains isolated from HIV-infected patients of Londrina, Southern Brazil, were carried out. Molecular analysis disclosed that all HTLV-2 strains belonged to 2a subtype, and RFLP detected the presence of the a4, a5, and a6 subgroups according to Switzer's nomenclature. RFLP correlated with nucleotide sequence, and phylogenetic analysis clustered HTLV-2 sequences of IDUs into subgroups a5 and a6. HTLV-2 sequences from individuals of sexual risk factor clustered into the a4 subgroup. These results extend the knowledge of the genetic diversity of HTLV-2 circulating in Brazil and provide insights into HTLV-2 transmission and virus movement in this geographic area.

Decision theory applied to image quality control in radiology

Background: The present work aims at the application of the decision theory to radiological image quality control ( QC) in diagnostic routine. The main problem addressed in the framework of decision theory is to accept or reject a film lot of a radiology service. The probability of each decision of a determined set of variables was obtained from the selected films. Methods: Based on a radiology service routine a decision probability function was determined for each considered group of combination characteristics. These characteristics were related to the film quality control. These parameters were also framed in a set of 8 possibilities, resulting in 256 possible decision rules. In order to determine a general utility application function to access the decision risk, we have used a simple unique parameter called r. The payoffs chosen were: diagnostic's result (correct/incorrect), cost (high/low), and patient satisfaction (yes/no) resulting in eight possible combinations. Results: Depending on the value of r, more or less risk will occur related to the decision-making. The utility function was evaluated in order to determine the probability of a decision. The decision was made with patients or administrators' opinions from a radiology service center. Conclusion: The model is a formal quantitative approach to make a decision related to the medical imaging quality, providing an instrument to discriminate what is really necessary to accept or reject a film or a film lot. The method presented herein can help to access the risk level of an incorrect radiological diagnosis decision.

Genome Survey Sequence Analysis and Identification of Homologs of Major Surface Protease (gp63) Genes in Trypanosoma rangeli

In this study, 222 genome survey sequences were generated for Trypanosoma rangeli strain P07 isolated from an opossum (Didelphis albiventris) in Minas Gerais State, Brazil. T. rangeli sequences were compared by BLASTX (Basic Local Alignment Search Tool X) analysis with the assembled contigs of Leishmania braziliensis, Leishmania infantum, Leishmania major, Trypanosoma brucei, and Trypanosoma cruzi. Results revealed that 82% (182/222) of the sequences were associated with predicted proteins described, whereas 18% (40/222) of the sequences did not show significant identity with sequences deposited in databases, suggesting that they may represent T. rangeli-specific sequences. Among the 182 predicted sequences, 179 (80.6%) had the highest similarity with T. cruzi, 2 (0.9%) with T. brucei, and 1 (0.5%) with L. braziliensis. Computer analysis permitted the identification of members of various gene families described for trypanosomatids in the genome of T. rangeli, such as trans-sialidases, mucin-associated surface proteins, and major surface proteases (MSP or gp63). This is the first report identifying sequences of the MSP family in T. rangeli. Multiple sequence alignments showed that the predicted MSP of T. rangeli presented the typical characteristics of metalloproteases, such as the presence of the HEXXH motif, which corresponds to a region previously associated with the catalytic site of the enzyme, and various cysteine and proline residues, which are conserved among MSPs of different trypanosomatid species. Reverse transcriptase-polymerase chain reaction analysis revealed the presence of MSP transcripts in epimastigote forms of T. rangeli.

A score system for quality evaluation of RNA sequence tags: an improvement for gene expression profiling

Background: High-throughput molecular approaches for gene expression profiling, such as Serial Analysis of Gene Expression (SAGE), Massively Parallel Signature Sequencing (MPSS) or Sequencing-by-Synthesis (SBS) represent powerful techniques that provide global transcription profiles of different cell types through sequencing of short fragments of transcripts, denominated sequence tags. These techniques have improved our understanding about the relationships between these expression profiles and cellular phenotypes. Despite this, more reliable datasets are still necessary. In this work, we present a web-based tool named S3T: Score System for Sequence Tags, to index sequenced tags in accordance with their reliability. This is made through a series of evaluations based on a defined rule set. S3T allows the identification/selection of tags, considered more reliable for further gene expression analysis. Results: This methodology was applied to a public SAGE dataset. In order to compare data before and after filtering, a hierarchical clustering analysis was performed in samples from the same type of tissue, in distinct biological conditions, using these two datasets. Our results provide evidences suggesting that it is possible to find more congruous clusters after using S3T scoring system. Conclusion: These results substantiate the proposed application to generate more reliable data. This is a significant contribution for determination of global gene expression profiles. The library analysis with S3T is freely available at http://gdm.fmrp.usp.br/s3t/.S3T source code and datasets can also be downloaded from the aforementioned website.

Concurrent sequence variation of TP53 and TP73 genes in anaplastic astrocytoma

Disruption or loss of tumor suppressor gene TP53 is implicated in the development or progression of almost all different types of human malignancies. Other members of the p53 family have been identified. One member, p73, not only shares a high degree of similarity with p53 in its primary sequence, but also has similar functions. Like p53, p73 can bind to DNA and activate transcription. Using PCR-SSCP and gene sequencing, we analyzed the TP53 and TP73 genes in a case of a grade III anaplastic astrocytoma that progressed to glioblastoma. We found a deletion of AAG at position 595-597 of TP53 (exon 6), resulting in the deletion of Glu 199 in the protein and a genomic polymorphism of TP73, identified as an A-to-G change, at position E8/+15 at intron 8 (IVS8-15A>G). The mutation found at exon 6 of the gene TP53 could be associated with the rapid tumoral progression found in this case, since the mutated p53 may inactivate the wild-type p53 and the p73 alpha protein, which was conserved here, leading to an increase in cellular instability.

Determination and Molecular Analysis of the Complete Genome Sequence of Two Wild-Type Rabies Viruses Isolated from a Haematophagous Bat and a Frugivorous Bat in Brazil

The complete genome sequences of two Brazilian wild-type rabies viruses (RABV), a BR-DR1 isolate from a haematophagous bat (Desmodus rotundus) and a BR-AL1 isolate from a frugivorous bat (Artibeus lituratus), were determined. The genomes of the BR-DR1 and RR-AL1 had 11,923 and 11,922 nt, respectively, and both encoded the five standard genes of rhabdoviruses. The complete nucleotide sequence identity between the BR-DR1 and BR-AL1 isolates was 97%. The BR-DR1 and BR-AL1 isolates had some conserved functional sites revealed by the fixed isolates, whereas both isolates had unique amino acid substitutions in the antigenic region IV of the nucleocapsid gene. Therefore, it is speculated that both isolates were nearly identical in virologic character. According to our phylogenetic analysis based on the complete genomes, both isolates belonged to genotype 1, and to the previously defined ""vampire bat-related RABV lineage"" which consisted of mainly D. rotundus- and A. lituratus- isolates; however, a branch pattern with high bootstrap values suggested that BR-DR1 was more closely related to the 9001FRA isolate, which was collected from a dog bitten by a bat in French Guiana, than to BR-AL1. This result suggests that the vampire bat-related RABV lineage includes Brazilian vampire bat and Brazilian frugivorous bat RABV and is further divided into Brazilian vampire bat and Brazilian frugivorous bat RABV sub-lineages. The phylogenetic analysis based on the complete genomes was valuable in discriminating among very closely related isolates.

Searching for star formation outside galaxies: Multiwavelength analysis of the intragroup medium of Hickson Compact Group 100

We use multiwavelength data (H I, FUV, NUV, R) to search for evidence of star formation in the intragroup medium of the Hickson Compact Group 100. We find that young star-forming regions are located in the intergalactic H I clouds of the compact group which extend to over 130 kpc away from the main galaxies. A tidal dwarf galaxy (TDG) candidate is located in the densest region of the H I tail, 61 kpc from the brightest group member and its age is estimated to be only 3.3 Myr. Fifteen other intragroup H II regions and TDG candidates are detected in the Galaxy Evolution Explorer (GALEX) FUV image and within a field 10' x 10' encompassing the H I tail. They have ages <200 Myr, H I masses of 10(9.2-10.4) M(circle dot), 0.001