37 research outputs found
Bilateral renal angiomyolipoma in a patient with tuberous sclerosis treated with resection of one kidney and transarterial embolization of other kidney using CT during selective arteriography: a case report
Renal AML complicating tuberous sclerosis shows a rapid growth and its rupture is frequently associated with hemorrhagic shock as a result of profuse retroperitoneal bleeding, necessitating an aggressive therapeutic approach. This report describes the long-term clinical progress of 28 year-old woman with tuberous sclerosis with a ruptured giant AML that underwent unilateral nephrectomy, who has been followed up after treatment with concomitant application of computed tomography during selective arteriography to conserve the remaining normal renal parenchyma, and in whom the need for initiation of dialysis has been successfully avoided, with conspicuous reduction of the tumor size
Soft-tissue perineurioma of the retroperitoneum in a 63-year-old man, computed tomography and magnetic resonance imaging findings: a case report
<p>Abstract</p> <p>Introduction</p> <p>Soft-tissue perineuriomas are rare benign peripheral nerve sheath tumors in the subcutis of the extremities and the trunks of young patients. To our knowledge, this the first presentation of the computed tomography and magnetic resonance imaging of a soft-tissue perineurioma in the retroperitoneum with pathologic correlation.</p> <p>Case presentation</p> <p>A 63-year-old Japanese man was referred for assessment of high blood pressure. Abdominal computed tomography and magnetic resonance imaging showed a well-defined, gradually enhancing tumor without focal degeneration or hemorrhage adjacent to the pancreatic body. Tumor excision with distal pancreatectomy and splenectomy was performed, as a malignant tumor of pancreatic origin could not be ruled out. No recurrence has been noted in the 16 months since the operation. Pathologic examination of the tumor revealed a soft-tissue perineurioma of the retroperitoneum.</p> <p>Conclusion</p> <p>Although the definitive diagnosis of soft-tissue perineurioma requires biopsy and immunohistochemical reactivity evaluation, the computed tomography and magnetic resonance imaging findings described in this report suggest inclusion of this rare tumor in the differential diagnosis when such findings occur in the retroperitoneum.</p
合併症を有するB型大動脈解離に対するステントグラフト内挿術における腎動脈に対する治療戦略 : 多施設共同研究
Background: Management of abdominal branches associated with Stanford type B aortic dissection is controversial without definite criteria for therapy after thoracic endovascular aortic repair (TEVAR). This is in part due to lack of data on natural history related to branch vessels and their relationship with the dissection flap, true lumen, and false lumen. Purpose: To investigate the natural history of abdominal branches after TEVAR for type B aortic dissection and the relationship between renal artery anatomy and renal volume as a surrogate measure of perfusion. Materials and Methods: This study included patients who underwent TEVAR for complicated type B dissection from January 2012 to March 2017 at 20 centers. Abdominal aortic branches were classified with following features: patency, branch vessel origin, and presence of extension of the aortic dissection into a branch (pattern 1, supplied by the true lumen without branch dissection; pattern 2, supplied by the true lumen with branch dissection, etc). The branch artery patterns before TEVAR were compared with those of the last follow-up CT (mean interval, 19.7 months) for spontaneous healing. Patients with one kidney supplied by pattern 1 and the other kidney by a different pattern were identified, and kidney volumes over the course were compared by using a simple linear regression model. Results: Two hundred nine patients (mean age ± standard deviation, 66 years ± 13; 165 men and 44 women; median follow-up, 18 months) were included. Four hundred fifty-nine abdominal branches at the last follow-up were evaluable. Spontaneous healing of the dissected branch occurred in 63% (64 of 102) of pattern 2 branches. Regarding the other patterns, 6.5% (six of 93) of branches achieved spontaneous healing. In 79 patients, renal volumes decreased in kidneys with pattern 2 branches with more than 50% stenosis and branches supplied by the aortic false lumen (patterns 3 and 4) compared with contralateral kidneys supplied by pattern 1 (pattern 2 vs pattern 1: −16% ± 16 vs 0.10% ± 11, P = .002; patterns 3 and 4 vs pattern 1: −13% ± 14 vs 8.5% ± 14, P = .004). Conclusion: Spontaneous healing occurs more frequently in dissected branches arising from the true lumen than in other branch patterns. Renal artery branches supplied by the aortic false lumen or a persistently dissected artery with greater than 50% stenosis are associated with significantly greater kidney volume loss.博士(医学)・乙第1461号・令和2年6月30日Copyright © 2019 by authors and RSNA. This work is licensed under the Creative Commons Attribution International License (CC BY-NC-ND 4.0). https://creativecommons.org/licenses/by-nc-nd/4.0/
Neuropeptide Receptor Transcriptome Reveals Unidentified Neuroendocrine Pathways
Neuropeptides are an important class of molecules involved in diverse aspects of metazoan development and homeostasis. Insects are ideal model systems to investigate neuropeptide functions, and the major focus of insect neuropeptide research in the last decade has been on the identification of their receptors. Despite these vigorous efforts, receptors for some key neuropeptides in insect development such as prothoracicotropic hormone, eclosion hormone and allatotropin (AT), remain undefined. In this paper, we report the comprehensive cloning of neuropeptide G protein-coupled receptors from the silkworm, Bombyx mori, and systematic analyses of their expression. Based on the expression patterns of orphan receptors, we identified the long-sought receptor for AT, which is thought to stimulate juvenile hormone biosynthesis in the corpora allata (CA). Surprisingly, however, the AT receptor was not highly expressed in the CA, but instead was predominantly transcribed in the corpora cardiaca (CC), an organ adjacent to the CA. Indeed, by using a reverse-physiological approach, we purified and characterized novel allatoregulatory peptides produced in AT receptor-expressing CC cells, which may indirectly mediate AT activity on the CA. All of the above findings confirm the effectiveness of a systematic analysis of the receptor transcriptome, not only in characterizing orphan receptors, but also in identifying novel players and hidden mechanisms in important biological processes. This work illustrates how using a combinatorial approach employing bioinformatic, molecular, biochemical and physiological methods can help solve recalcitrant problems in neuropeptide research
Simple Case Study on Radius of Radial Basis Function Network for Sequential Approximate Optimization
Radial basis function (RBF) networks are used for various research field. Especially, they make handling easy for classification and function approximation due to their mathematical form. Some parameters of an RBF network should be carefully selected to obtain good performance for a specific problem. This study investigates the radius of an RBF network in a simple case for sequential approximate optimization. The result shows that there is an effective radius range for sequential approximate optimization methods
The Nei’s Standard Genetic Distance in Artificial Evolution
Abstract — In recent years, not only ruggedness but also neutrality has been recognized as an important feature of a fitness landscape for genetic search. Following that the concept of neutrality in artificial evolution originates from Kimura’s neutral theory in natural evolution, it is expected that the dynamics of artificial evolution in the landscapes including neutrality would be described by using techniques in population genetics. Furthermore, new theoretical guidelines might be developed for effective genetic search. In a recent paper [25], we have discussed the use of the Nei’s standard genetic distance, which originates from population genetics, for measuring neutrality of fitness landscapes. In our results, several consistencies with the population genetics have been found by applying the Nei’s standard genetic distance to a tunably neutral NK landscape. In this paper, computer simulations are systematically conducted by using a standard genetic algorithm in order to clarify the characteristics of the Nei’s standard genetic distance. The terraced NK landscape is adopted as a test function. I
K.: An approach to evolutionary robotics using a genetic algorithm with a variable mutation rate strategy
Abstract. Neutral networks, which occur in fitness landscapes containing neighboring points of equal fitness, have attracted much research interest in recent years. In recent papers [20, 21], we have shown that, in the case of simple test functions, the mutation rate of a genetic algorithm is an important factor for improving the speed at which a population moves along a neutral network. Our results also suggested that the benefits of the variable mutation rate strategy used by the operon-GA [5] increase as the ruggedness of the landscapes increases. In this work, we conducted a series of computer simulations with an evolutionary robotics problem in order to investigate whether our previous results are applicable to this problem domain. Two types of GA were used. One was the standard GA, where the mutation rate is constant, and the other was the operon-GA, whose effective mutation rate at each locus changes independently according to the history of the genetic search. The evolutionary dynamics we observed were consistent with those observed in our previous experiments, confirming that the variable mutation rate strategy is also beneficial to this problem.