Total Endovascular Debranching of the Aortic Arch

Background: Significant morbidity and mortality are related to conventional aortic replacement surgery. Endovascular debranching techniques, fenestrated or branched endografts are time consuming and costly.Objective: We alternatively propose to use endovascular approach with parallel grafts for debranching of aortic arch.Methods: Under general anesthesia, 12 F sheaths were inserted in the femoral, axillary and common carotid arteries for vascular accesses. ViaBahn grafts 10 - 15 cm in length were placed into the aortic arch from right common carotid, left common carotid and left axillary arteries, until the tip of each graft reached into the ascending aorta. Through one femoral artery, the aortic stent-graft was positioned and delivered. Soon after, the parallel grafts were sequentially delivered. Self-spanding Wallstents(R) were used for parallel grafts reinforcement. Ballooning was routinely used for parallel grafts and rarely for aortic graft.Results: This technique was used in 2 cases. The first one was a lady with 72 years old, with an aortic retrograde dissection from left subclavian artery and involving remaining arch branches. Through right common carotid artery a stent-graft was placed in the ascending aorta and through the left common carotid artery a ViaBahn was inserted parallel to the former. A thoracic endograft then covered all the aortic arch dissection extending into the ascending aorta close to the sinu-tubular junction. The second case was a 82 year old male patient with a 7 cm aortic arch aneurysm. Through both common carotid arteries ViaBahn grafts were introduced and positioned into the ascending aorta. Soon after, the deployment of the thoracic stent graft covered all parallel grafts of the aortic arch, excluding the aneurysm. Both cases did not have neurologic or cardiac complications and were discharged 10 days after the procedure.Conclusions: This technique may be a good minimal invasive off-the-shelf technical option for aortic arch "debranching". More data and further improvements are required before this promising technique can be widely advocated. (C) 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Presence and morphology of the molar tubercle according to dentition, hemi-arch and sex

The purpose of this study was to assess the presence and the degree of expression of the molar tubercle according to sex, dentition and hemi-arches. Study casts of 126 patients were assessed, and those were under orthodontic treatment at the University of Franca, UNIFRAN; they were from both sexs, from 4 to 13 years old. The upper second primary molars and the upper first permanent molars, from both sides, were evaluated regarding the presence and the degree of expression of the molar tubercle. For an association study, the qui-square test was utilized. The concordance about the presence or absence of the molar tubercle according to dentition, hemi-arch and sex, was estimated by the Kappa Statistics. There was a sexual dimorphism concerning the presence/absence of the molar tubercle (p=0.009), however there was no significant association between the degree of expression of the tubercle and the sex (p=0.791). The molar tubercle was more frequently observed in the male sex, in upper second primary molars and in the form of depression. There was a significant and "moderate" concordance between the left and right sides in primary dentition (k=0.596), there was a "good" concordance in permanent dentition (k=0.708) and a "weak" and significant concordance between the presence of the molar tubercle and dentition (k=0.207).

Ultrastructural aspects of the intercellular bridges between female bee germ cells

No ovário das abelhas as células germinativas e as células foliculares são interconectadas por pontes intercelulares mantidas abertas por reforços do citoesqueleto na membrana plasmática. As pontes entre as células germinativas têm comportamento dinâmico e provavelmente atuam na determinação do ovócito entre as células do clone formado pelas mitoses pré meióticas formando posteriormente uma via de transporte para que os produtos sintetizados pelas células nutridoras atinjam o ovócito durante sua maturação. Os elementos do citoesqueleto presentes nas pontes intercelulares das gônadas das abelhas são basicamente microfilamentos e microtúbulos, mas nas pontes entre os cistócitos pré-meióticos outro tipo de filamento (espesso de natureza não definida, associado a elementos do retículo endoplasmático) está presente, atravessando a ponte e prendendo-se através dos microfilamentos à membrana plasmática. Estes filamentos aparentemente controlam o vão da ponte. Terminada a fase de proliferação os cistócitos tomam a forma de uma roseta e um fusoma, formado pela convergência das pontes, aparece no centro desta. Nesta conformação os filamentos grossos não estão presentes. Nova mudança ocorre com a diferenciação do ovócito e das células nutridoras, com a reorientação de todas as pontes de maneira a canalizar o conteúdo das futuras células nutridoras para o ovócito.

Comparison between the complete Bayesian method and empirical Bayesian method for ARCH models using Brazilian financial time series

In this work we compared the estimates of the parameters of ARCH models using a complete Bayesian method and an empirical Bayesian method in which we adopted a non-informative prior distribution and informative prior distribution, respectively. We also considered a reparameterization of those models in order to map the space of the parameters into real space. This procedure permits choosing prior normal distributions for the transformed parameters. The posterior summaries were obtained using Monte Carlo Markov chain methods (MCMC). The methodology was evaluated by considering the Telebras series from the Brazilian financial market. The results show that the two methods are able to adjust ARCH models with different numbers of parameters. The empirical Bayesian method provided a more parsimonious model to the data and better adjustment than the complete Bayesian method.

Assignment of the disulfide bridges in bothropstoxin-I, a myonecrotic Lys49 PLA(2) homolog from Bothrops jararacussu snake venom

Bothropstoxin-I (BthTX-1), a Lys49 phospholipase A(2) homolog with no apparent catalytic activity, was first isolated from Bothrops jararacussu snake venom and completely sequenced in this laboratory. It is a 121-amino-acid single polypeptide chain, highly myonecrotic, despite its inability to catalyze hydrolysis of egg yolk phospholipids, and has 14 half-cystine residues identified at positions 27, 29, 44, 45, 50, 51, 61, 84, 91, 96, 98, 105, 123, and 131 (numbering according to the conventional alignment including gaps, so that the last residue is Cys 131). In order to access its seven disulfide bridges, two strategies were followed: (1) Sequencing of isolated peptides from (tryptic + SV8) and chymotryptic digests by Edman-dansyl degradation; (2) crystallization of the protein and determination of the crystal structure so that at least two additional disulfide bridges could be identified in the final electron density map. Identification of the disulfide-containing peptides from the enzymatic digests was achieved following the disappearance of the original peptides from the HPLC profile after reduction and carboxymethylation of the digest. Following this procedure, four bridges were initially identified from the tryptic and SV8 digests: Cys50-Cys131, Cys51-Cys98, Cys61-Cys91, and Cys84-Cys96. From the chymotryptic digest other peptides were isolated either containing some of the above bridges, therefore confirming the results from the tryptic digest, or presenting a new bond between Cys27 and Cys123. The two remaining bridges were identified as Cys29-Cys45 and Cys44-Cys105 by determination of the crystal structure, showing that BthTX-1 disulfide bonds follow the normal pattern of group II PLA(2)s.

Rift to post-rift evolution of a passive continental margin: the Ponta Grossa Arch, SE Brazil

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

Morphology of Aortic Arch in Rabbits with Atherosclerosis Treated with Resveratrol

Objective: Atherosclerosis is a chronic inflammatory condition associated with the production of oxidative species. The phenoliccompound, resveratrol, seems to have cardioprotective activities preventing the oxidation of low-density lipoproteins.In this study we investigated the effect of resveratrol on prevention of induced atheromatosis, through the morphological study of the segment of aortic arch in White New Zealand rabbits.Study design: 20 rabbits were divided into four groups which received the following diet for 60 days: control group (CT) normal ration; resveratrol group (R) normal ration and resveratrol (3 mg/kg/day); cholesterol group (CL) 1.5% of cholesterol added to the ration; group cholesterol plus resveratrol (CR) 1.5% of cholesterol added to the ration and resveratrol (3 mg/kg/day). The analysis of the atherosclerotic lesions were performed by the means of appropriate histological techniques.Results and conclusions: The animals belonging to group CL showed atherosclerotic lesions with tunica intima thickening due to the presence of foam cells, placed in several disorganized layers, and extracellular lipid droplets in subendothelial conjunctive tissue.We also observed the invasion of foam cells in the beginning of tunica media. In animals belonging to group CR there were changes in the subendothelial of tunica intima, although in a minor degree of development as for the number of foam cells layers and extracellular lipid droplets. An invasion of foam cells in tunica media was observed in this group. We haven't seen any changes in tunica adventitia in any of the studied groups. There were not evident histological changes in any of the analised tunicas for groups CT and RConclusions: This study may help demonstrate that the phenolic compound, resveratrol, works as a preventive agent in the development of atherosclerotic lesions.

Cytoplasmic bridges, intercellular junctions, and individualization of germ cells during spermatogenesis in Dermatobia hominis (Diptera: Cuterebridae)

During mitotic and meiotic divisions in Dermatobia hominis spermatogenesis, the germ cells stay interlinked by cytoplasm, bridges as a result of incomplete cytokinesis. By the end of each division, cytoplasmic bridges flow to the center of the cyst, forming a complex, called the fusoma. During meiotic prophase I, spermatocytes I present desmosome-like junctions and meiotic cytoplasmic bridges. At the beginning of spermiogenesis, the fusoma moves to the future caudal end of the cyst, and at this time the early spermatids are linked by desmosome-like junctions. Throughout spermiogensis, new and sometimes broad cytoplasmic bridges are formed among spermatids at times making them share cytoplasm. In this case the individualization of cells is assured by the presence of smooth cisternae that outline then structures The more differentiated spermatids have in addition to narrow cytoplasmic bridges, plasmic membranes junctions. By the end of spermiogenesis the excess cytoplasmic mass is eliminated leading to spermatid individualization. Desmosome-like junctions of spermatocytes I and early spermatids appear during the fusoma readjustment and segregations; on the other hand, plasmic membrane junctions appear in differentiating spermatids and are eliminated along with the cytoplasmic excess. These circumstances suggest that belt desmosome-like and plasmic membrane junctions are involved in the maintenance of the relative positions of male germ cells in D. hominis while they are inside the cysts. © 1996 Wiley-Liss, Inc.

Loss of space and dental arch length after the loss of the lower first primary molar: A longitudinal study

The premature loss of primary teeth may harm the normal occlusal development, although there are debates relating to the necessity of using space maintainer appliances. The aim of the study is to evaluate the changes in the dental arch perimeter and the space reduction after the premature loss of the lower first primary molar in the mixed dentition stage. The sample consists of 4 lower arch plaster models of 31 patients, within the period of pre-extraction, 6, 12 and 18 months after the lower first primary molar extraction. A reduction of space was noted with the cuspid dislocation and the permanent incisors moving toward the space of the extraction site. It was concluded that the lower first molar primary premature loss, during the mixed dentition, implicates an immediate placement of a space maintainer.

Hydroxylapatite implants with or without collagen in the zygomatic arch of rats. Histological study.

The authors studied the behavior of calcium phosphate materials used as inlay implants into bone cavities prepared in the zygomatic arch of rats. Fifty male albino rats were divided into four groups as follows: group I-preparation of bone cavities which did not receive any implant material as controls; group II-implants of Interpore 200; group III-implants of experimental hydroxylapatite; group IV-implants of experimental hydroxylapatite combined with collagen. The animals were sacrificed after 5, 15, 30, 60 and 120 days and the specimens were submitted to histological analysis. Results showed that the experimental hydroxylapatite used in group III presented better osteogenic properties compared to the other materials. All tested materials were biocompatible, although group IV presented a more intense inflammatory response.

Assignment of the bisulfide bridges in bothropstoxin-I, a Myonecrotic Lys49 PLA2 homolog from bothrops jararacussu snake venom

Bothropstoxin-I (BthTX-I), a Lys49 phospholipase A2 homolog with no apparent catalytic activity, was first isolated from Bothrops jararacussu snake venom and completely sequenced in this laboratory. It is a 121-amino-acid single polypeptide chain, highly myonecrotic, despite its inability to catalyze hydrolysis of egg yolk phospholipids, and has 14 half-cystine residues identified at positions 27, 29, 44, 45, 50, 51, 61, 84, 91, 96, 98, 105, 123, and 131 (numbering according to the conventional alignment including gaps, so that the last residue is Cys 131). In order to access its seven disulfide bridges, two strategies were followed: (1) Sequencing of isolated peptides from (tryptic + SV8) and chymotryptic digests by Edman-dansyl degradation; (2) crystallization of the protein and determination of the crystal structure so that at least two additional disulfide bridges could be identified in the final electron density map. Identification of the disulfide-containing peptides from the enzymatic digests was achieved following the disappearance of the original peptides from the HPLC profile after reduction and carboxymethylation of the digest. Following this procedure, four bridges were initially identified from the tryptic and SV8 digests: Cys50-Cysl31, Cys51-Cys98, Cys61-Cys91, and Cys84-Cys96. From the chymotryptic digest other peptides were isolated either containing some of the above bridges, therefore confirming the results from the tryptic digest, or presenting a new bond between Cys27 and Cys 123. The two remaining bridges were identified as Cys29-Cys45 and Cys44-Cysl05 by determination of the crystal structure, showing that BthTX-I disulfide bonds follow the normal pattern of group II PLA2s. © 2001 Plenum Publishing Corporation.

Reliability of timber bridges using nailed plywood box beams

The Nailed Box Beam structural efficiency is directly dependent of the flange-web joint behavior, which determines the partial composition of the section, as the displacement between elements reduces the effective rigidity of the section and changes the stress distribution and the total displacement of the section. This work discusses the use of Nailed Plywood Box Beams in small span timber bridges, focusing on the reliability of the beam element. It is presented the results of tests carried out in 21 full scale Nailed Plywood Box Beams. The analysis of maximum load tests results shows that it presents a normal distribution, permitting the characteristic values calculation as the normal distribution theory specifies. The reliability of those elements was analyzed focusing on a timber bridge design, to estimate the failure probability in function of the load level.