28 research outputs found

    チアノーゼ性心疾患に対する肺動脈絞扼術

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    The early and late results of pulmonary artery banding (PAB) for cyanotic heart defects in early infancy were reviewed. Nine patients were divided into two groups : Group F (five patiens) in which Fontan type repairs were expected as definitive repair in the near future ; Group A (four patients) in which anatomical repairs were programmed in the near future. Six patients had a good early postoperative course, and then consisted of three patients of Group A and three patients of Group F. The band circumference, intraoperative pulmonary-to-systemic systolic pressure ratio and arterial oxygen tension after PAB in the good cases of Group A were 20.0±1.7 mm + 1 mm for each kilogram of the infant's weight, 0.52±0.07 and 46.4±11.3 mmHg respectively. These indices in the good cases of Group F were 21.1±1.7 mm + 1 mm for each kilogram of the infant's weight, 0.55±0.02 and 38.8±1.0 mmHg respectively. The standard deviations of every index for PAB in Group F were small. Three patients of Group A have undergone successful total correction. Intraoperative pulmonary-to-systemic systolic pressure ratio of 0.5 as the index of PAB is preferable to Group A. However, only two patient of Group F were waiting for Fontan type definitive repair. For the patient especially in Group F, careful observation and well-timed staged repair with regard to subaortic stenosis and restrictive atrial septal defect and ventricular septal defect are necessary after accurate PAB as mentioned above

    High-Grade Renal MTSCC

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    Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare subtype of renal cell carcinoma. Although usually indolent, high-grade MTSCC has been reported to exhibit an aggressive clinical course. Herein, we report a case of high-grade renal MTSCC. An 86-year-old man visited our hospital with fever and fatigue. Based on contrast-enhanced computed tomography findings, the patient was diagnosed with clinical stage T2aN0M0 right renal cell carcinoma and underwent laparoscopic radical nephrectomy. Histological examination showed tubular to tubulopapillary structures accompanied by mucinous stroma, suggesting high-grade renal MTSCC. He remained recurrence- and metastasis-free 6 months after nephrectomy. Since high-grade renal MTSCC may have an aggressive clinical course, such patients should be observed carefully after radical nephrectomy

    The Direct Synthesis of H <sub>2</sub> O <sub>2</sub> Using TS-1 Supported Catalysts

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    In this study we show that using gold palladium nanoparticles supported on a commercial titanium silicate (TS‐1) prepared using a wet co‐impregnation method it is possible to produce hydrogen peroxide from molecular H2 and O2 via the direct synthesis reaction. The effect of Au: Pd ratio and calcination temperature is evaluated as well as the role of platinum addition to the AuPd supported catalysts. The effect of platinum addition to gold‐palladium nanoparticles is observed to result in a significant improvement in catalytic activity and selectivity to hydrogen peroxide with detailed characterisation indicating this is a result of selectively tuning the ratio of palladium oxidation states

    Micropapillary Variant of UC in an HD Patient

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    The micropapillary variant of urothelial carcinoma (MPUC) is an aggressive form of urothelial carcinoma with high metastatic potential and a poor prognosis. Although various therapies have been reported, there is still no established treatment strategy for MPUC due to its rarity. The incidence of urinary tract malignancies is higher in patients undergoing hemodialysis (HD) than in healthy individuals. Here, we report the case of an 82-year-old man on HD with end-stage kidney disease who visited our hospital for macrohematuria. Cystoscopy followed by computed tomography and urine cytology revealed a sessile papillary tumor around the left bladder wall. We performed transurethral resection of the bladder tumor. Based on histopathological and imaging findings indicative of clinical-stage T3N0M0 MPUC, we performed radical cystectomy. Histopathology revealed a pathological stage T4aN0M0 MPUC. Two months after the cystectomy, the patient complained of constipation and painful defecation due to local recurrence and rectal invasion. While colostomy was performed to improve defecation 3 months after cystectomy, he did not receive any chemotherapy due to his progressively worsening general condition. Six months after cystectomy, he died following rapid metastases. Our findings, in this case, confirm that bladder cancer in HD patients tends to be pathologically more advanced. Therefore, regular screening is recommended for its early detection in HD patients

    Highly efficient catalytic production of oximes from ketones using in situ-generated H<sub>2</sub>O<sub>2</sub>

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    The ammoximation of cyclohexanone using preformed hydrogen peroxide (H2O2) is currently applied commercially to produce cyclohexanone oxime, an important feedstock in nylon-6 production. We demonstrate that by using supported gold-palladium (AuPd) alloyed nanoparticles in conjunction with a titanium silicate-1 (TS-1) catalyst, H2O2 can be generated in situ as needed, producing cyclohexanone oxime with >95% selectivity, comparable to the current industrial route. The ammoximation of several additional simple ketones is also demonstrated. Our approach eliminates the need to transport and store highly concentrated, stabilized H2O2, potentially achieving substantial environmental and economic savings. This approach could form the basis of an alternative route to numerous chemical transformations that are currently dependent on a combination of preformed H2O2 and TS-1, while allowing for considerable process intensification

    Surgical management of infants with mitral valve stenosis or atresia without diminutive ascending aorta

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    The surgical strategy in infants with mitral valve stenosis or atresia without diminutive ascending aorta remains to be established, including the potential for biventricular repair as a definitive operation. Our surgical experience of six infants with mitral valve stenosis (4patients) or atresia (2patients) without diminutive ascending aorta was evaluated based on three important factors:left ventricular volume;the nature of the systemic outflow obstruction; and the type of mitral valve anomaly. Two patients with systemic outflow tract diameter less than 65% of normal underwent systemic outflow tract reconstruction, and the other patients with outflow tract diameter more than 68%of normal were able to maintain systemic circulation without repair. Only one patient with mitral valve stenosis without left ventricular outflow tract obstruction underwent a successful open mitral valvotomy as a biventricular repair after first-stage palliation. The left ventricle of the other patients did not grow after first-stage palliation. Due to progressive subaortic narrowing, pulmonary artery banding should be avoided in patients with mitral atresia due to absent atrioventricular connection who are future Fontan candidates. Most patients with this lesion can be expected to become candidates for safe Fontan-type repair

    Cyclohexanone ammoximation via in situ H2O2 production using TS-1 supported catalysts

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    The ammoximation of cyclohexanone to the corresponding oxime via in situ H2O2 formation offers an attractive alternative to the current industrial means of production, overcoming the significant economic and environmental concerns associated with the manufacture of a key reagent, H2O2. Herein we demonstrate the efficacy of a composite catalyst, consisting of precious metal nanoparticles supported on a commercial TS-1, towards the in situ synthesis of cyclohexanone oxime, bridging the wide condition gap that exists between the two distinct reaction pathways: H2O2 direct synthesis and cyclohexanone ammoximation. In particular, the alloying of Au with Pd and the introduction of low concentrations of Pt into AuPd nanoalloys are found to be key in promoting high catalytic performance. The improved catalytic activity of optimal catalysts is found to result from a combination of a disruption of contiguous Pd ensembles and the modification of Pd oxidation states, which in turn dictate catalytic activity towards the production and subsequent degradation of H2O2

    Thread-Traction with a Sheath of Polypectomy Snare Facilitates Endoscopic Submucosal Dissection of Early Gastric Cancers

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    Although the thread-traction (TT) method has been found useful during endoscopic submucosal dissection (ESD) for early gastric cancers, the movement of the thread interferes with the movement of the endoscope, and the lesion can only be pulled to the mouth side. We have developed the novel TT method using a sheath of polypectomy snare (TTSPS). The TTSPS method enables free and independent movement of the thread and the endoscope and allows pulling the lesion towards the anal as well as oral side. The median dissection times, numbers of instances of arterial bleeding, and numbers of local injections into the submucosal layer were significantly lower for ESD with TTSPS than for conventional ESD. Countertraction ESD using the TTSPS method is straightforward, safe, easy, noninvasive, and cost effective, and it uses instruments readily available in most hospitals to enhance visualization of cutting lines. Therefore, the TTSPS method can be universally applied in conventional ESD

    Selective Ammoximation of Ketones via In Situ H2O2 Synthesis

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    The ammoximation of ketones to the corresponding oxime via the in situ production of H2O2 offers a viable alternative to the current means of industrial-scale production, in particular for the synthesis of cyclohexanone oxime, a key precursor to Nylon-6. Herein, we demonstrate that using a bifunctional catalyst, consisting of Pd-based bimetallic nanoparticles immobilized onto a TS-1 carrier, it is possible to bridge the considerable condition gap that exists between the two key distinct reaction pathways that constitute an in-situ approach (i.e., the direct synthesis of H2O2 and ketone ammoximation). The formation of PdAu nanoalloys is found to be crucial in achieving high reactivity and in promoting catalytic stability, with the optimal formulation significantly outperforming both alternative Pd-based materials and the monometallic Pd analogue
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