A case of spontaneous rupture of renal cell carcinoma

Spontaneous rupture of the kidney is uncommon. We report a case of spontaneous rupture of the kidney due to a renal cell carcinoma. A 53-year-old man presented with right renal tumor. Computed tomography demonstrated a 70 mm right renal tumor which involved the entire upper pole of the kidney and extended into the renal vein. A few days later, the patient had sudden severe right flank pain. Computed tomography of the abdomen revealed a large perirenal hematoma of the right kidney. Angiography demonstrated no vascular abnormality. Nephrectomy was performed. The histological examination showed rupture of a renal cell carcinoma in the right kidney.     

Remarkable effect of addition of In and Pb on the reduction of N2O by CO over SiO2 supported Pd catalysts

The effect of addition of In and Pb on the reduction of N₂O by CO was studied over SiO₂ supported Pd catalysts, using a closed gas circulation system as well as in-situ infrared spectroscopy. Formation of intermetallic compounds such as Pd_0.48In_0.52, Pd₃Pb and Pd₃Pb₂ was observed which caused a drastic enhancement of the rate of N₂ formation. The infrared spectroscopic analyses revealed a weakening of the adsorption strength of CO on Pd metal by the formation of intermetallic compounds, which is likely the main reason for the enhancement of the reaction rate. From a kinetic investigation as well as in situ FT-IR observation during the N₂O-CO reaction, a redox mechanism was proposed involving the oxidation of the surface by N₂O followed by its reduction by CO. Over Pd/SiO₂, the former process seems to be the rate limiting step because of the inhibition of N₂O activation by strongly adsorbed CO. By adding In or Pb, the rate limiting step shifted to the latter process, which resulted in a large enhancement in the rate of N₂ formation.     

Effects of viscosities on the transient current in homeotropic nematic liquid crystal cells

Effects of the Leslie viscosity coefficients α_i (i = 1, 2, …, 5) of nematic liquid crystals (NLCs) with negative dielectric anisotropy (Δε < 0) on the electric-field-induced director reorientation in homeotropic NLC cells have been studied from the analysis of the transient current induced by step voltage application. The transient current in a homeotropic NLC cell with Δε < 0 was well reproduced by computer simulation, based on the theory of NLCs in which the flow effects and the free-slip boundary condition are taken into account. It is found that the response time of vertical alignment NLC displays is dominantly governed by α₂ and α₄ + α₅ of NLCs with Δε < 0.     

Small round and spindle cell sarcoma with neuronal differentiation and oncocyte-like features of the thoracic wall: a case report with histological, immunohistochemical and ultrastructural examinations

A case of small round and spindle cell sarcoma with neuronal differentiation and oncocyte-like features is presented. The tumor was encountered in a 32 year old Japanese woman with an initial presentation of palpable tumor in the left lateral region of the thorax. The resected tumor was a partially well encapsulated whitish medullary one and consisted of small round and spindle tumor cells, together with so-called rhabdoid cells in the small round cell area. Although pseudorosettes were often observed, true rosette formation could not be detected anywhere. Ultrastructurally, despite a histologic variety of tumor cells, most tumor cells possessed numerous mitochondria, some of which occasionally contained abnormal filamentous or crystalloid structures. Various amounts of microfilaments were present in most tumor cells and microtubules were present in a few. A minority of small round cells possessed a small number of neurosecretory granules, especially in short cytoplasmic processes. A positive immunoreaction for neuron specific enolase was found by immunohistochemical examination in several small round tumor cells and for neurofilaments in lesser numbers. Despite the lack of S-100 protein, MB2 was detected in both small round and spindle cells. On the basis of these findings, the tumor of the present case corresponds to malignant peripheral nerve sheath tumor with neuronal differentiation and oncocytic features.     

Floral organ-specific and constitutive expression of an Arabidopsis thaliana heat-shock HSP18.2::GUS fusion gene is retained even after homeotic conversion of flowers by mutation

Organ-specific and constitutive expression of the Arabidopsis HSP18.2 gene under normal growth conditions (22 degrees C) was observed in transgenic A. thaliana, which carried a fusion gene composed of the promoter region of HSP18.2, one of the genes for low molecular weight heat-shock proteins in Arabidopsis, and the gene for beta-glucuronidase (GUS) from Escherichia coli. In order to clarify the organ-specific nature of promoter expression, various mutations that affect flower morphology were introduced into the transgenic Arabidopsis line, AHS9. The results show that the pattern of expression observed in sepals, filaments, and styles is regulated in a structure-dependent manner, and suggest that the HSP18.2 gene might have an important role in the process of differentiation of flower buds, as do several other stress-related genes.     

Electromagnetic field analysis by boundary element method using spatial eigenmodes

This paper proposes a boundary-element method using spatial eigenmodes for electromgnetic field analysis. Mapping the computation model with rotational symmetries, reflective symmetries or rotational symmetries including reflective symmetries to a group of spatial eigenmodes, the equivalent reduced models are obtained. In the method, the applicability becomes wide because arbitrary external source terms can be chosen. Furthermore, in a model including asymmetry regions, a new method which can save the merit of the symmetries is proposed. Finally, the validity of the proposed method is proved by numerical simulations.     

Behavior of insoluble materials in artificial contamination tests

It was reported that the dc flashover voltage under an artificial contamination test sometimes was affected considerably by the type of insoluble materials in the contaminant. To clarify the cause of this phenomenon, the physical characteristics of some contamination slurries and the conductivity of the artificially contaminated insulator surfaces are investigated experimentally. The test results lead to the conclusion that the variation in the flashover voltage is caused mainly by the characteristics of conductive films formed on the insulator surface in the clean fog test     

Expression of structure-specific recognition protein mRNA in fetal kidney and Fe-nitrilotriacetate-induced renal carcinoma in the rat

Specific expression of the structure-specific recognition protein (SSRP) gene was investigated in rat fetal, adult, and tumor tissues using a 2.0-kb partial sequence of rat SSRP cDNA isolated from a cDNA library of rat renal cell carcinoma. The results revealed that it was rather specifically expressed in rat fetal kidney and renal cell carcinoma induced by Fenitrilotriacetate, but not in adult kidney, when various organs were tested by Northern blot analysis. In situ hybridization further demonstrated that it was located in the neoplastic cells of renal cell carcinoma and in the epithelial cells of fetal kidney but undetectable in any cells of normal adult kidney. These observations seem to imply the involvement of SSRP gene, which is believed to recognize structural alterations of DNA, in kidney development and carcinogenesis of certain types of kidney cancer.     

Local disappearance of epiphyseal growth plates in rats with hypervitaminosis A

Epiphyseal growth plates of proximal tibiae in rats with high doses of vitamin A (V-A) were observed. Of 4 groups, each consisting of 5 rats, three groups were given V-A at doses, IU/100 g by body weight/day, of 50,000, 100,000, and 150,000, respectively. The other group rats were given no V-A (control). Rats were administered V-A for the 5 days from 4 weeks after birth and sacrificed at 12 weeks after birth. Three rats of the 150,000 IU group died during the period of observation. The decalcified sections were stained with hematoxylin-eosin or toluidine blue. In the ground sections, microradiography, backscattered electron imaging, and energy-dispersive X-ray microanalysis were performed. These observations suggest that the local disappearance of epiphyseal growth plates under high doses of V-A goes in the order of the increased doses through the process of (1) calcified cartilage areae appearing in the resting cell zone, (2) some of the calcified areae extending in the growth plate towards the diaphysial side, (3) bone tissue replacing the calcified areae, and (4) the local disappearing of the growth plate. Such a local disappearance may be formed in the stressed proximal regions of tibiae.     

Photolysis of poly(3-buten-2-one), poly(4,4-dimethyl-1-penten-3-one), and poly(3-methyl-3-buten-2-one) in the presence of oxygen

Photolysis of poly(3-buten-2-one) (PMVK), poly(4,4-dimethyl-1-penten-3-one) (PBVK), and poly(3-methyl-3-buten-2-one) (PMIK) were carried out in dioxane under oxygen or nitrogen bubbling. The main chain degradations of PBVK and PMIK were quenched and polymeric peroxides were produced. The heat treatment of the polymer irradiated in the presence of oxygen promoted the degradation. The photodegradation of PMVK was enhanced in the presence of oxygen.