148 resultados para Diametro mesio-distal
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Marcelo A. Scelzo, Marina Z. Fantucci, and Fernando L. Mantelatto (2010) Spermatophore and gonopore morphology of the southwestern-Atlantic hermit crab Pagurus exilis (Benedict, 1892) (Anomura, Paguridae). Zoological Studies 49(3): 421-433. The form and function of the spermatophore have been used as a complementary tool in studies of the reproductive biology and systematics of hermit crabs. In this context, we describe the spermatophore and gonopore morphology of Pagurus exilis. The spermatophores were extracted from the distal part of the vas deferens of specimens collected in Argentina and Brazil. The spermatophores were composed of 3 major regions: a main ampulla (with a sperm capsule inside and an accessory ampulla at the base), a stalk, and a pedestal. Each spermatophore had a distinct dorsolateral suture line around the ampulla, where the rupture occurs to release the sperm. The spermatophore total length was 1.5 times the main ampulla length. The main ampulla was oval and slightly flattened. A triangular accessory ampulla extended from the main ampulla base to the pedestal on 1 side, and contained no to several sperm. The stalk is short and flattened, and as wide as the main ampulla. One to 3 spermatophores were found attached to each pedestal, which was almost oblong in shape. The dimensions of the spermatophore and its component parts were directly influenced by the size of the hermit crab. Gonopores of males were covered by long pappose setae, while female gonopores bore a few short cuspidate setae. Specimens from Brazil and Argentina had the same spermatophore morphology, corroborating the previously observed absence of genetic differences between the both populations. The spermatophore morphology of this species has similarities with the broad general pattern of the Paguridae, being most similar to one of the (at least) 3 patterns of spermatophore morphology described for Pa gurus. http://zoolstud.sinica.edu.tw/Journals/49.3/421.pdf
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A new species of Almeidea (Rutaceae) belonging to the neotropical tribe Galipeeae (subtribe Galipeinae) is described and illustrated. This new species, Almeidea albiflora, is known so far only from a few collections made in small disturbed forest remnants in the vicinity of Cachoeiro de Itapemirim, in the state of Espirito Santo, and by a single collection from northern Rio de Janeiro state, both in the domain of the Atlantic Forest, Eastern Brazil. Diagnostic features, like white petals, sericeous ovary and distal secondary axes as long as the proximal ones are identified. Pollen morphology is also described, and brief discussions of the relationships of the new taxon to other species of Almeidea, as well as comments on its conservation status, are provided.
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The six peculiar multicusped teeth described here were collected from sediments of the Upper Cretaceous of Sao Jose do Rio Preto Formation, near Ibira (northeastern Sao Paulo, Brazil). Their bulbous crowns are slightly labio-lingual compressed, and bear a main plus two accessory cusps, which conceal a well developed cingulum. Wear facets are seen on the main and distal accessory cusps. Comparison to the known Crocodyliformes with multicusped teeth show that the new material is not referable to ""protosuchians"" or eusuchians, nor related to two unnamed forms from Morocco and ""notosuchians"" such as Uruguaysuchus, Chiamaerasuchus, and Simosuchus. On the other hand, possible affinities with Candidodon and Malawisuchus were maintained based on shared traits. This includes teeth with the main cusp and some accessory cusps arranged in more than one axis, a previously defined unambiguous apomorphy of the putative clade composed of Candidodon plus Malawisuchus. The term Candidodontidae can be applied to this group, and defined as all taxa closer to Candidodon itapecuruensis than to Notosuchus terrestris, Uruguaysuchus aznarezi, Comahuesuchus brachybuccalis, Sphagesaurus huenei, Baurusuchus pachecoi, and Crocodylus niloticus. (C) 2009 Elsevier Ltd. All rights reserved.
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Paratrizygia conformis, the type-species of the genus Paratrizygia, from Tasmania, is redescribed from the holotype. The wing venation and male terminalia are illustrated in detail. The question of the monophyly of the genus-which has four additional species in Chile and southern Argentina, and four species in the Atlantic Forest, in Brazil-is addressed. Comments are made on the relationships of the genus in the Azana-group of Sciophilinae. The hypothesis of monophyly of Paratrizygia is retained, as indicated by the presence of modified, elongated spines on a distal fold of tergite 9.
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Recent investigations in the upper Rio Huallaga in Peru revealed the presence of an intriguing species of the Loricariinae. To characterize and place this species within the evolutionary tree of the subfamily, a molecular phylogeny of this group was inferred based on the 12S and 16S mitochondrial genes and the nuclear gene F-reticulon4. The phylogeny indicated that this distinctive species was a member of the subtribe Loricariina. Given its phylogenetic placement, and its unusual morphology, this species is described as a new genus and new species of Loricariinae: Fonchiiloricaria nanodon. This new taxon is diagnosed by usually possessing one to three premaxillary teeth that are greatly reduced; lips with globular papillae on the surface; the distal margin of lower lip bearing short, triangular filaments; the premaxilla greatly reduced; the abdomen completely covered by plates, with the plates between lateral abdominal plates small and rhombic; a caudal fin with 14 rays; the orbital notch absent; five lateral series of plates; dorsal-fin spinelet absent; preanal plate present, large and solid, and of irregular, polygonal shape, the caudal peduncle becoming more compressed posteriorly for the last seven to 10 plates. (C) 2011 The Authors Journal of Fish Biology (C) 2011 The Fisheries Society of the British Isles
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To better comprehend the structural and biochemical underpinnings of ion uptake across the gills of true freshwater crabs, we performed an ultrastructural, ultracytochemical and morphometric investigation, and kinetically characterized the Na(+), K(+)-ATPase, in posterior gill lamellae of Dilocarcinus pagei. Ultrastructurally, the lamellar epithelia are markedly asymmetrical: the thick, mushroom-shaped, proximal ionocytes contain elongate mitochondria (41% cell volume) associated with numerous (approximate to 14 mu m(2) membrane per mu m(3) cytoplasm), deep invaginations that house the Na(+), K(+)-ATPase, revealed ultracytochemically. Their apical surface is amplified (7.5 mu m(2) mu m(-2)) by stubby evaginations whose bases adjoin mitochondria below the subcuticular space. The apical membrane of the thin, distal ionocytes shows few evaginations (1.6 mu m(2) mu m(-2)), each surrounding a mitochondrion, abundant in the cytoplasm below the subcuticular space; basolateral invaginations and mitochondria are few. Fine basal cytoplasmic bridges project across the hemolymph space, penetrating into the thick ionocytes, suggesting ion movement between the epithelia. Microsomal Na(+), K(+)-ATPase specific activity resembles marine crabs but is approximate to 5-fold less than in species from fluctuating salinities, and freshwater shrimps, suggesting ion loss compensation by strategies other than Na(+) uptake. Enzyme apparent K(+) affinity attains 14-fold that of marine crabs, emphasizing the relevance of elevated K(+) affinity to the conquest of fresh water. Western blotting and biphasic ouabain inhibition disclose two alpha-subunit isoforms comprising distinct functional isoenzymes. While enzyme activity is not synergistically stimulated by NH(4)(+) and K(+), each increases affinity for the other, possibly assuring appropriate intracellular K(+) concentrations. These findings reveal specific structural and biochemical adaptations that may have allowed the establishment of the Brachyura in fresh water. J. Exp. Zool. 313A:508-523, 2010. (C) 2010 Wiley-Liss, Inc.
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Background. The main purpose of the present investigation was to describe a model of intestinal denervation and in situ intestinal ischemia-reperfusion injury in adult rats, with utilization of the distal branch of the superior mesenteric artery close to the cecum for perfusion. Methods. In the root of the mesentery, the mesenteric artery and vein were completely isolated. Close to the cecal valve, a lymphatic node served as the reference point for the localization of the cecal artery, which was cannulated for perfusion with cold lactated Ringer`s solution. One hundred adult male rats were utilized in the study. Results. In a pilot study, we demonstrated that the cold ischemia time was sufficient to promote histopathologic intestinal changes characteristic of ischemia-reperfusion injury. Among 88 operated animals, 62 (70.5%) survived the procedure. Conclusion. The experimental model described herein has the advantage of preserving the entire intestine, which makes it more suitable for studies of physiological and morphological alterations after intestinal transplantation.
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Anorectal transplantation is a valid procedure for the treatment of anorectal dysfunction; however, the lack of a suitable animal model has hampered the development of this method. We describe a simple technique for anorectal transplantation in the rat and compare this procedure with colostomy. The anorectal segment including the skin surrounding the anus were freed by abdominal and perineal dissection. In a heterotopically transplanted group the segment was exteriorized by the formation of an anus through an abdominal incision. In an orthotopically transplanted group the segment was replaced in its original position and reimplanted by suturing. In another group a distal colostomy was performed. A sham-treated control group (simulated surgical procedure) was also included. Changes in behavior, characteristics of the stool, body weight and survival rate were assessed by daily clinical examination. Moribund animals, those with a weight loss of more than 30%, and those surviving at 1 month were killed by an overdose of anesthetic. The results were analyzed using the Mann Whitney, Student`s t and chi-squared tests, and p < 0.05 was considered significant. Within 4 days after the operation, animals submitted to orthotopic or heterotopic transplantation had achieved normal defecation, body weight gain and clinical evolution similar to the sham-treated group. The overall mortality in these groups was 4.16%. In contrast, colostomized animals showed a high incidence of diarrhea, intestinal obstruction, stress posture and violent behavior (pa parts per thousand currency sign0.05), and a mortality rate of 58.33%. Autotransplantation in the rat is a simple technique, achieves a high rate of success and better clinical evolution than colostomy. This model may ultimately lead to research into anorectal transplantation.
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OBJECTIVE: To describe the microsurgical anatomy, branches, and anatomic relationships of the posterior cerebral artery (PCA) represented in three-dimensional images. METHODS: Seventy hemispheres of 35 brain specimens were studied. They were previously injected with red silicone and fixed in 10% formalin for at least 40 days. Four of the studied specimens were frozen at -10 degrees to -15 degrees C for 14 days, and additional dissection was done with the Klingler`s fiber dissection technique at x6 to x40 magnification. Each segment of the artery was measured and photographed to obtain three-dimensional stereoscopic images. RESULTS: The PCA origin was in the interpeduncular cistern at the pontomesencephalic junction level in 23 specimens (65.7%). The PCA was divided into four segments: P1 extends from the PCA origin to its junction with the posterior communicating artery with an average length of 7.7 mm; P2 was divided into an anterior and posterior segment. The P2A segment begins at the posterior communicating artery and ends at the most lateral aspect of the cerebral peduncle, with an average length of 23.6 mm, and the P2P segment extends from the most lateral aspect of the cerebral peduncle to the posterior edge of the lateral surface of the midbrain, with an average length of 16.4 mm; P3 extends from the posterior edge of the lateral surface of the midbrain and ends at the origin of the parieto-occipital sulcus along the calcarine fissure, with an average length of 19.8 mm; and the P4 segment corresponds to the parts of the PCA that run along or inside both the parieto-occipital sulcus and the distal part of the calcarine fissure. CONCLUSIONS: To standardize the neurosurgical practice and knowledge, surgical anatomic classifications should be used uniformly and further modified according to the neurosurgical experience gathered. The PCA classification proposed intends to correlate its anatomic segments with their required microneurosurgical approaches.
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Introduction: Airway dysfunction in patients with the Acute Respiratory Distress Syndrome (ARDS) is evidenced by expiratory flow limitation and dynamic hyperinflation. These functional alterations have been attributed to closure/obstruction of small airways. Airway morphological changes have been reported in experimental models of acute lung injury, characterized by epithelial necrosis and denudation in distal airways. To date, however, no study has focused on the morphological airway changes in lungs from human subjects with ARDS. The aim of this study is to evaluate structural and inflammatory changes in distal airways in ARDS patients. Methods: We retrospectively studied autopsy lung tissue from subjects who died with ARDS and from control subjects who died of non pulmonary causes. Using image analysis, we quantified the extension of epithelial changes (normal, abnormal and denudated epithelium expressed as percentages of the total epithelium length), bronchiolar inflammation, airway wall thickness, and extracellular matrix (ECM) protein content in distal airways. The Student`s t test or the Mann-Whitney test was used to compare data between the ARDS and control groups. Bonferroni adjustments were used for multiple tests. The association between morphological and clinical data was analyzed by Pearson rank test. Results: Thirty-one ARDS patients (A: PaO(2)/FiO(2) <= 200, 45 +/- 14 years, 16 males) and 11 controls (C:52 +/- 16 years, 7 males) were included in the study. ARDS airways showed a shorter extension of normal epithelium (A:32.9 +/- 27.2%, C:76.7 +/- 32.7%, P < 0.001), a larger extension of epithelium denudation (A:52.6 +/- 35.2%, C:21.8 +/- 32.1%, P < 0.01), increased airway inflammation (A:1(3), C:0(1), P = 0.03), higher airway wall thickness (A:138.7 +/- 54.3 mu m, C:86.4 +/- 33.3 mu m, P < 0.01), and higher airway content of collagen I, fibronectin, versican and matrix metalloproteinase-9 (MMP-9) compared to controls (P = 0.03). The extension of normal epithelium showed a positive correlation with PaO(2)/FiO(2) (r(2) = 0.34; P = 0.02) and a negative correlation with plateau pressure (r(2) = 0.27; P = 0.04). The extension of denuded epithelium showed a negative correlation with PaO(2)/FiO(2) (r(2) = 0.27; P = 0.04). Conclusions: Structural changes in small airways of patients with ARDS were characterized by epithelial denudation, inflammation and airway wall thickening with ECM remodeling. These changes are likely to contribute to functional airway changes in patients with ARDS.
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Background and objectives: Cardiac positioning and stabilization during myocardial revascularization without extracorporeal circulation (ECC) may cause hemodynamic changes dependent to the surgical site. The objective of this study was to evaluate these changes during distal coronary anastomosis. Methods: Twenty adult patients undergoing myocardial revascularization without ECC were monitored by pulmonary artery catheter and transesophageal Echo Doppler. Hemodynamic data were collected at the following times before removing the stabilizer wall: (1) after volume adjustments, (2) at the beginning of distal anastomosis, and (3) after 5 minutes. Treated coronary arteries were grouped according to their location in the lateral, anterior, or posterior wall. Two-way ANOVA with repetition and Newman-Keuls post-test were used in the analysis. A p value < 0.05 was considered statically significant. Results: During myocardial revascularization without ECC, pulmonary artery wedge pressure showed elevation from 17.7 +/- 6.1 to 19.2 +/- 6.5 (p < 0.001) and 19.4 +/- 5.9 mmHg (p < 0.001), while the central venous pressure went from 13.9 +/- 5.4 to 14.9 +/- 5.9 mmHg (p = 0.007) and 15.1 +/- 6.0 mmHg (p = 0.006). Intermittent cardiac output was reduced from 4.70 +/- 1.43 to 4.23 +/- 1.22 (p < 0.001) and 4.26 +/- 1.25 L.min(-1) (p < 0.001). According to transesophageal Doppler, a significant group-time interaction was observed in cardiac output, which was reduced in the lateral group from 4.08 +/- 1.99 to 2.84 +/- 1.82 (p = 0.02) and 2.86 +/- 1.73 L.min(-1) (p = 0.02), and aortic blood flow, which went from 2.85 +/- 1.39 to 1.99 +/- 1.26 (p = 0.02) and 2.00 +/- 1.21 L.min(-1) (p = 0.02). Other hemodynamic changes were not observed during anastomoses. Conclusions: A significant hemodynamic deterioration was observed during myocardial revascularization without ECC. Transesophageal Doppler detected a decrease in cardiac output only in the lateral group.
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Background: Percutaneous transluminal angioplasty has been used with increasing frequency in the treatment of infrainguinal arterial occlusive disease. This meta-analysis aimed to assess the middle-term outcomes after crural angioplasty in patients with chronic critical limb ischemia and compare results with a meta-analysis of popliteal-to-distal vein bypass graft. Methods: Data were retrieved from 30 articles published from 1990 through 2006 (63% of articles published between 2000 and 2006). All studies used survival analysis, reported a 12-month cumulative rate of patency or limb salvage, and included at least 15 infrapopliteal angioplasties. The outcome measures were immediate technical success, primary and secondary patency, limb salvage, and patient survival. Data from life-tables, survival curves, and texts were used. Results. The pooled estimate of success was 89.0% +/- 2.2% for immediate technical result. Results at 1 and 36 months were 77.4% +/- 4.1% and 48.6% +/- 8.0% for primary patency, 83.3% +/- 1.4% and 62.9% +/- 11.0% for secondary patency, 93.4% +/- 2.3% and 82.4% +/- 3.4% for limb salvage, and 98.3% +/- 0.7% and 68.4% +/- 5.5% for patient survival, respectively. Studies with >75% of the limbs with tissue loss fared worse than their respective comparative subgroup for technical success and patency but not for limb salvage or survival. No publication bias was detected. Conclusion: The technical success and subsequent durability of crural angioplasty are limited compared with bypass surgery, but the clinical benefit is acceptable because limb salvage rates are equivalent to bypass surgery. Further studies are necessary to determine the proper role of infrapopliteal angioplasty.
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Objective: To describe bypass to perigeniculate vessels for limb salvage. Design: Retrospective cohort study. Material and methods: Between 1995 and 2009, 47 bypass procedures to perigeniculate collateral arteries were performed in 46 patients (15 women, 31 men; median age, 68 years). All patients presented with critical ischaemia (tissue loss in 87.5%, rest pain in 12.5%). Mean ankle brachial index was 0.27 +/- 0.17. The site of distal anastomosis was the descending genicular artery (DGA) in 23 bypasses (1 bilateral) and the medial sural artery (MSA) in 24. Proximal anastomosis was to the external iliac artery in 2 cases, common femoral artery in 23 cases, superficial femoral artery in 8 cases, deep femoral artery in 8 cases, above-knee poplitaeal artery in 2 cases, and previous graft in 4 cases. Results: There were four deaths during the immediate postoperative period. Mean follow-up duration was 27 months. Ten patients required major amputation. Mean ankle brachial index post-operatively was 0.60 +/- 0.21. At 3 years, primary patency was 74.7 +/- 7%, secondary patency was 83.4 +/- 8%, and the limb salvage and survival rates were 73.5 +/- 7% and 77.4 +/- 7%, respectively. Conclusion: Bypass to perigeniculate arteries is a viable treatment option for critical limb ischaemia in selected patients. (C) 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.
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Purpose: Achalasia of the esophagus is characterized by aperistalsis and incomplete relaxation of the lower esophageal sphincter in response to swallowing. The objective of the present study is to present the experience of a modified Heller myotomy via a laparoscopic approach for the treatment of children who had this condition. Methods: A retrospective review of medical records of all patients who underwent this procedure from 2000 to 2009 was performed. The procedure consisted of an extended esophagomyotomy beginning on the lower part of the lower esophageal sphincter and continuing 5 to 6 cm above on the lower third of the esophagus, and then extended 3 to 4 cm below to the stomach, associated with an anterior 180-degree hemi-fundoplication according to Dor`s technique. Results: Fifteen patients were included in the study. There were 8 female and 7 male patients. Mean operating time was 190 minutes with no intraoperative complications and 1 conversion to open surgery because of difficulty in dissecting an inflamed distal esophagus. In a mean follow-up period of 32.3 months, 2 patients had recurrence of mild dysphagia that disappeared spontaneously, and 1 required a single botulinum toxin injection with complete resolution of symptoms. Conclusion: We conclude that the laparoscopic extended Heller myotomy with Dor fundoplication is a safe and effective method for the treatment for achalasia in the pediatric population even in advanced cases. (C) 2010 Elsevier Inc. All rights reserved.
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PURPOSE: To report a series of patients with symptomatic internal carotid artery (ICA) occlusion treated with angioplasty and stents. MATERIALS AND METHODS: From a consecutive series of 50 patients experiencing neurologic ischemic symptoms and shown by conventional ultrasonography (US) to have a total ICA occlusion, 16 patients (ages 45-79 years; mean, 63 y; 10 men) were selected between August 2006 to September 2008 to be treated with angioplasty based on discovery of an open ICA distal to the occlusion through contrast-enhanced echo Doppler imaging and/or multislice contrast computed tomography (CT). Angioplasty and stent placement were performed under cerebral protection. Follow-up duplex imaging was performed at 14 days and 3 months and every 6 months thereafter and CT follow-up was performed at 2-9 months; the mean follow-up period was 9.9 months. RESULTS: Lesion crossing and stent placement was successful in 13 of 16 patients. There were no deaths, conversions, cardiac complications, or major strokes. One patient had a transient mild hemiparesis in the upper limb, with total recovery in 3 months. At follow-up, all 13 patients with a good initial result remained with patent arterial lumens and resolution of neurologic ischemic symptoms. After 2-9 months, ICAs with a ""string sign"" had calibers close or equal to those of normal arteries. CONCLUSIONS: Angioplasty with stent placement is an effective treatment with a low morbidity rate for selected patients who continue to experience neurologic ischemic symptoms despite US findings of total occlusion of the ICA.