967 resultados para apical leakage
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STUDY OBJECTIVE: To estimate the frequency of vaginal voiding as the cause of daytime urinary leakage in girls, and to study the effect of instructions intended to alleviate the problem. SETTING: Girls with vaginal voiding were identified in a group of girls referred because of daytime urinary leakage. They were evaluated by a noninvasive screening protocol. Girls with vaginal voiding were instructed on how to achieve better toilet habits. PARTICIPANTS: Twelve girls with vaginal voiding. RESULTS: Vaginal voiding was found in 12 of 39 girls with daytime urinary leakage. Their age ranged between 8.5 and 13.9 years. They all had history of small leakage immediately after voiding. A body mass index greater than the corresponding 85th percentile was noted in 5 girls, and labial fusion was noted in 2 girls. The complaint disappeared in 10 girls and improved in the remaining 2 girls after instructions on how to achieve better toilet habits. CONCLUSIONS: Vaginal voiding is common in girls. It occurs in girls at risk of overweight, in girls with labial fusion, and in girls adopting a hairpin posture while sitting on the toilet. The diagnosis is obtained by an adequate history. Proper voiding instructions resolve the problem.
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In contrast-enhanced (CE) MR myelography, hyperintense signal outside the intrathecal space in T1-weighted sequences with spectral presaturation inversion recovery (SPIR) is usually considered to be due to CSF leakage. We retrospectively investigated a hyperintense signal at the apex of the lung appearing in this sequence in patients with SIH (n = 5), CSF rhinorrhoea (n = 2), lumbar spine surgery (n = 1) and in control subjects (n = 6). Intrathecal application of contrast agent was performed in all patients before MR examination, but not in the control group. The reproducible signal increase was investigated with other fat suppression techniques and MR spectroscopy. All patients and controls showed strongly hyperintense signal at the apex of the lungs imitating CSF leakage into paraspinal tissue. This signal increase was identified as an artefact, caused by spectroscopically proven shift and broadening of water and lipid resonances (1-2 ppm) in this anatomical region. Only patients with SIH showed additional focal enhancement along the spinal nerve roots and/or in the spinal epidural space. In conclusion CE MR myelography with spectral selective fat suppression shows a reproducible cervicothoracic artefact, imitating CSF leakage. Selective water excitation technique as well as periradicular and epidural contrast collections may be helpful to discriminate between real pathological findings and artefacts.
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Background Airborne particles entering the respiratory tract may interact with the apical plasma membrane (APM) of epithelial cells and enter them. Differences in the entering mechanisms of fine (between 0.1 μm and 2.5 μm) and ultrafine ( ≤ 0.1 μm) particles may be associated with different effects on the APM. Therefore, we studied particle-induced changes in APM surface area in relation to applied and intracellular particle size, surface and number. Methods Human pulmonary epithelial cells (A549 cell line) were incubated with various concentrations of different sized fluorescent polystyrene spheres without surface charge (∅ fine – 1.062 μm, ultrafine – 0.041 μm) by submersed exposure for 24 h. APM surface area of A549 cells was estimated by design-based stereology and transmission electron microscopy. Intracellular particles were visualized and quantified by confocal laser scanning microscopy. Results Particle exposure induced an increase in APM surface area compared to negative control (p < 0.01) at the same surface area concentration of fine and ultrafine particles a finding not observed at low particle concentrations. Ultrafine particle entering was less pronounced than fine particle entering into epithelial cells, however, at the same particle surface area dose, the number of intracellular ultrafine particles was higher than that of fine particles. The number of intracellular particles showed a stronger increase for fine than for ultrafine particles at rising particle concentrations. Conclusion This study demonstrates a particle-induced enlargement of the APM surface area of a pulmonary epithelial cell line, depending on particle surface area dose. Particle uptake by epithelial cells does not seem to be responsible for this effect. We propose that direct interactions between particle surface area and cell membrane cause the enlargement of the APM.
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To provide an integrated perspective on mineral particle effects in salmonids, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to daily mica particle pulses for 8 and 24 days. On day 8, increased immature erythrocyte proportions indicated a previous stress response. This response was absent on day 24, on which condition factor as well as plasma protein and aspartate aminotransferase activity decreased. The latter two related negatively to the hepato-somatic index, suggesting metabolic adaptations. The hepato-somatic index increased on days 8 and 24, while spleen-somatic index increased on day 24. No histopathological damage occurred in gills, liver, spleen, or kidney. However, splenic melano-macrophages increased on both days, and hyaline degenerations of kidney tubular cells were apparent on day 24. Overall, particle pulses affected rainbow trout more via turbidity rather than by physical damage. We conclude that (i) rainbow trout may adapt to sediment pulses as early as 8 days of exposure and (ii) particle pulses over 24 days can cause structural and metabolic changes in rainbow trout, even when gill damage is absent and apical effects on condition are moderate.
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INTRODUCTION Apical surgery is an important treatment option for teeth with postendodontic apical periodontitis. However, little information is available regarding treatment planning in cases referred for apical surgery. This study evaluated the decisions made in such cases and analyzed the variables influencing the decision-making process. METHODS The study retrospectively assessed clinical and radiographic data of 330 teeth that had been referred to a specialist in apical surgery with regard to the treatment decisions made in those teeth. The clinical and radiographic variables were divided into subcategories to analyze which factors influenced the decision-making process. RESULTS The treatment decisions included apical surgery (59.1%), tooth extraction (25.8%), no treatment (9.1%), and nonsurgical endodontic retreatment (6.1%). Variables that showed statistically significant differences comparing treatment decisions among subcategories included probing depth (P = .001), clinical attachment level (P = .0001), tooth mobility (P = .012), pain (P = .014), clinical signs (P = .0001), length (P = .041) and quality (P = .026) of the root canal filling, and size (P = .0001) and location (P = .0001) of the periapical lesion. CONCLUSIONS This study shows that apical surgery was the most frequently made treatment decision in teeth referred to a specialist in apical surgery, but every fourth tooth was considered nonretainable and was scheduled for extraction. The data showed that the most common variables that influenced the decision to extract teeth were teeth with an increased probing depth and tooth mobility and teeth presenting with lesions not located at the apex.
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The apical-basal axis of the early plant embryo determines the body plan of the adult organism. To establish a polarized embryonic axis, plants evolved a unique mechanism that involves directional, cell-to-cell transport of the growth regulator auxin. Auxin transport relies on PIN auxin transporters 1], whose polar subcellular localization determines the flow directionality. PIN-mediated auxin transport mediates the spatial and temporal activity of the auxin response machinery 2-7] that contributes to embryo patterning processes, including establishment of the apical (shoot) and basal (root) embryo poles 8]. However, little is known of upstream mechanisms guiding the (re)polarization of auxin fluxes during embryogenesis 9]. Here, we developed a model of plant embryogenesis that correctly generates emergent cell polarities and auxin-mediated sequential initiation of apical-basal axis of plant embryo. The model relies on two precisely localized auxin sources and a feedback between auxin and the polar, subcellular PIN transporter localization. Simulations reproduced PIN polarity and auxin distribution, as well as previously unknown polarization events during early embryogenesis. The spectrum of validated model predictions suggests that our model corresponds to a minimal mechanistic framework for initiation and orientation of the apical-basal axis to guide both embryonic and postembryonic plant development.
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Introduction: Dehiscence of the suture line of an anastomosis can lead to reoperation, temporary or permanent stoma, and even sepsis or death. Few techniques for the laboratory training of tubular anastomosis use ex-vivo animal tissues. We describe a novel model that can be used in the laboratory for the training of anastomosis in tubular tissues and objectively assess any anastomotic leak. [See PDF for complete abstract]
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The prevailing uncertainties about the future of the post-Kyoto international legal framework for climate mitigation and adaptation increase the likelihood of unilateral trade interventions that aim to address climate policy concerns, as exemplified by the controversial European Union initiative to include the aviation industry in its emissions trading system. The emerging literature suggests that border carbon adjustment (BCA) measures imposed by importing countries would lead to substantial legal complications in relation to World Trade Organization law and hence to possible trade disputes. Lack of legal clarity on BCAs is exacerbated by potential counter or pre-emptive export restrictions that exporting countries might impose on carbon-intensive products. In this context, this paper investigates the interface between legal and welfare implications of competing unilateral BCA measures. It argues that carbon export taxes will be an inevitable part of the future climate change regime in the absence of a multilateral agreement. It also describes the channels through which competing BCAs may lead to trade conflicts and political complications as a result of their distributional and welfare impacts at the domestic and global levels.
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Previous studies from our lab have established that large molecular weight mucin glycoproteins are major apically-disposed components of mouse uterine epithelial cells in vitro (Valdizan et al., (1992) J. Cell. Physiol. 151:451-465). The present studies demonstrate that Muc-1 represents one of the apically-disposed mucin glycoproteins of mouse uterine epithelia, and that Muc-1 protein and mRNA expression are regulated in the peri-implantation stage mouse uterus by ovarian steroids. Muc-1 expression is high in the proestrous and estrous stages, and decreases during diestrous. Both Muc-1 protein and mRNA levels decline to barely detectable levels by day 4 of pregnancy, i.e., prior to the time of blastocyst attachment. In contrast, Muc-1 expression in the cervix and vagina is maintained during this same period. Delayed implantation was established in pregnant mice by ovariectomy and maintained by administration of exogenous progesterone. Initiation of implantation was triggered by coinjection of progesterone maintained mice with a nidatory dose of 17$\beta$-estradiol. Muc-1 levels in the uterine epithelia of progesterone maintained mice declined to similar low levels as observed on day 4 of normal pregnancy. Coinjection of estradiol did not alter Muc-1 expression suggesting that down-regulation of Muc-1 is a progesterone dominated event. This was confirmed in ovariectomized, non-pregnant mice which displayed stimulation of Muc-1 expression following 6 hr of estradiol injection. Estradiol stimulated Muc-1 expression was inhibited by the pure antiestrogen, ICI 164,384. While progesterone alone had no effect on Muc-1 expression, it antagonized estradiol action in this regard. Injection of pregnant mice with the antiprogestin, RU 486, a known implantation inhibitor, on day 3 of pregnancy restored high level expression of Muc-1 mRNA on day 4, indicating that down-regulation of Muc-1 is progesterone receptor-mediated. Muc-1 appears to function as an anti-adhesive molecule at the apical cell surface of mouse uterine epithelial cells. Treatment of polarized cultures of mouse uterine epithelial cells with O-sialoglycoprotein endopeptidase reduced mucin expression in vitro, by about 50%, and converted polarized uterine epithelia to a functionally receptive state. Similarly, ablation of Muc-1 in Muc-1 null mice resulted in polarized uterine epithelia that were functionally receptive as compared to their wild-type counterparts in vitro. Collectively, these data indicate that Muc-1 and other mucins function as anti-adhesive molecules and that reduction or removal of these molecules is a prerequisite for the generation of a receptive uterine state. ^
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Plants exhibit life-long organogenic and histogenic activity in a specialised organ, the shoot apical meristem. Leaves and flowers are formed within the ring-shaped peripheral zone, which surrounds the central zone, the site of the stem cells. We have undertaken a series of high-precision laser ablation and microsurgical tissue removal experiments to test the functions of different parts of the tomato meristem, and to reveal their interactions. Ablation of the central zone led to ectopic expression of the WUSCHEL gene at the periphery, followed by the establishment of a new meristem centre. After the ablation of the central zone, organ formation continued without a lag. Thus, the central zone does not participate in organogenesis, except as the ultimate source of founder cells. Microsurgical removal of the external L-1 layer induced periclinal cell divisions and terminal differentiation in the subtending layers. In addition, no organs were initiated in areas devoid of L-1, demonstrating an important role of the L-1 in organogenesis. L-1 ablation had only local effects, an observation that is difficult to reconcile with phyllotaxis theories that invoke physical tension operating within the meristem as a whole. Finally, regeneration of L-1 cells was never observed after ablation. This shows that while the zones of the meristem show a remarkable capacity to regenerate after interference, elimination of the L-1 layer is irreparable and causes terminal differentiation.
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INTRODUCTION Recent meta-analyses of the outcome of apical surgery using modern techniques including microsurgical principles and high-power magnification have yielded higher rates of healing. However, the information is mainly based on 1- to 2-year follow-up data. The present prospective study was designed to re-examine a large sample of teeth treated with apical surgery after 5 years. METHODS Patients were recalled 5 years after apical surgery, and treated teeth were classified as healed or not healed based on clinical and radiographic examination. (The latter was performed independently by 3 observers). Two different methods of root-end preparation and filling (primary study parameters) were to be compared (mineral trioxide aggregate [MTA] vs adhesive resin composite [COMP]) without randomization. RESULTS A total of 271 patients and teeth from a 1-year follow-up sample of 339 could be re-examined after 5 years (dropout rate = 20.1%). The overall rate of healed cases was 84.5% with a significant difference (P = .0003) when comparing MTA (92.5%) and COMP (76.6%). The evaluation of secondary study parameters yielded no significant difference for healing outcome when comparing subcategories (ie, sex, age, type of tooth treated, post/screw, type of surgery). CONCLUSIONS The results from this prospective nonrandomized clinical study with a 5-year follow-up of 271 teeth indicate that MTA exhibited a higher healing rate than COMP in the longitudinal prognosis of root-end sealing.
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SUMMARY BACKGROUND/OBJECTIVES Orthodontic management of maxillary canine impaction (MCI), including forced eruption, may result in significant root resorption; however, the association between MCI and orthodontically induced root resorption (OIRR) is not yet sufficiently established. The purpose of this retrospective cohort study was to comparatively evaluate the severity of OIRR of maxillary incisors in orthodontically treated patients with MCI. Additionally, impaction characteristics were associated with OIRR severity. SUBJECTS AND METHODS The sample comprised 48 patients undergoing fixed-appliance treatment-24 with unilateral/bilateral MCI and 24 matched controls without impaction. OIRR was calculated using pre- and post-operative panoramic tomograms. The orientation of eruption path, height, sector location, and follicle/tooth ratio of the impacted canine were also recorded. Mann-Whitney U-test and univariate and multivariate linear mixed models were used to test for the associations of interest. RESULTS Maxillary central left incisor underwent more OIRR in the impaction group (mean difference = 0.58mm, P = 0.04). Overall, the impaction group had 0.38mm more OIRR compared to the control (95% confidence interval, CI: 0.03, 0.74; P = 0.04). However, multivariate analysis demonstrated no difference in the amount of OIRR between impaction and non-impaction groups overall. A positive association between OIRR and initial root length was observed (95% CI: 0.08, 0.27; P < 0.001). The severity of canine impaction was not found to be a significant predictor of OIRR. LIMITATIONS This study was a retrospective study and used panoramic tomograms for OIRR measurements. CONCLUSIONS This study indicates that MCI is a weak OIRR predictor. Interpretation of the results needs caution due to the observational nature of the present study.
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INTRODUCTION The aim of this study was to evaluate the concordance of 2- and 3-dimensional radiography and histopathology in the diagnosis of periapical lesions. METHODS Patients were consecutively enrolled in this study provided that preoperative periapical radiography (PR) and cone-beam computed tomographic imaging of the tooth to be treated with apical surgery were performed. The periapical lesional tissue was histologically analyzed by 2 blinded examiners. The final histologic diagnosis was compared with the radiographic assessments of 4 blinded observers. The initial study material included 62 teeth in the same number of patients. RESULTS Four lesions had to be excluded during processing, resulting in a final number of 58 evaluated cases (31 women and 27 men, mean age = 55 years). The final histologic diagnosis of the periapical lesions included 55 granulomas (94.8%) and 3 cysts (5.2%). Histologic analysis of the tissue samples from the apical lesions exhibited an almost perfect agreement between the 2 experienced investigators with an overall agreement of 94.83% (kappa = 0.8011). Radiographic assessment overestimated cysts by 28.4% (cone-beam computed tomographic imaging) and 20.7% (periapical radiography), respectively. Comparing the correlation of the radiographic diagnosis of 4 observers with the final histologic diagnosis, 2-dimensional (kappa = 0.104) and 3-dimensional imaging (kappa = 0.111) provided only minimum agreement. CONCLUSIONS To establish a final diagnosis of an apical radiolucency, the tissue specimen should be evaluated histologically and specified as a granuloma (with/without epithelium) or a cyst. Analysis of 2-dimensional and 3-dimensional radiographic images alike results only in a tentative diagnosis that should be confirmed with biopsy.