Renal cell carcinoma: preoperative assessment for enucleative surgery with angiography, CT, and MRI

PURPOSE: Our purpose was to assess various imaging methods in detecting a pseudocapsule of renal cell carcinoma (RCC), which is critical for successful tumor enucleation. METHOD: In 42 patients with histopathologically proven RCC, images obtained at angiography (n = 42), CT (n = 30), and MRI (n = 19) were investigated retrospectively. All patients underwent treatment (enucleation: n = 15; nephrectomy: n = 27). The imaging criteria for the presence of a pseudocapsule were as follows: a surrounding radiolucent rim on angiography, a low or high density rim on CT, and a low intensity rim on MRI. All images were retrospectively reviewed by three radiologists without knowledge of the clinical and histological findings. RESULTS: Thirty-three of 42 RCCs showed a pseudocapsule on the surgical specimen. A pseudocapsule was detected in 67% of tumors (22/33) on angiography, 26% (6/23) on CT, 27% (4/15) on T1-weighted MRI, 93% (14/15) on T2-weighted MRI, 67% (8/12) on dynamic enhanced T1-weighted MRI, and 15% (2/13) on delayed enhanced T1-weighted MRI. CONCLUSION: T2-weighted MR images are superior for visualizing a pseudocapsule of RCC and for providing reliable selection criteria for tumor enucleation.     

A convenient synthesis of functionalized alkoxyamines as initiators for living free radical polymerization

Summary 2,2,6,6-Tetramethylpiperidine- 1-oxyl (TEMPO) was reacted with ethylbenzene (la), 1-bromo-4-ethylbenzene (lb), and 4-ethylphenyl acetate (lc), respectively, using tert-BuOOWCo(OAc)·4H₂O in acetonitrile at room temperature. The reactions produced the respective TEMPO-adducts (2a, 2b, and 2c) in the yields of 37, 44, and 45 %, which were based on TEMPO. Similarly, TEMPO was reacted with 4-ethylphenyl 2,3,6,2',3',4',6'-hepta-O-acetyl-β-D-cellobioside (1d) to afford the glycoconjugated TEMPO-adduct (2d) in 45 5% yield, which was based on 1d. These results indicated that the reaction has the potential to become an easy and also safe strategy, which provided various functionalized alkoxylamines. Received 20 November 2002/Revised Version: 5 December 2002/ Accepted: 7 December 2002 Correspondence to Naoya Sugimoto     

Gd-DTPA enhanced multi-shot echo-planar MRI: improvement of contrast between metastatic liver cancer and liver parenchyma

Budd-Chiari syndrome is a rare and serious thrombotic event with significant morbidity and mortality. Recommendations regarding future conception and management during pregnancy have not been defined. We present a patient with history of idiopathic Budd-Chiari Syndrome and subsequent orthotopic liver transplantation who was successfully managed during pregnancy. A 24-year-old white female, gravida 1 para 0, status postorthotopic liver transplantation 5 years previously for Budd-Chiari syndrome with post-transplant insulin-dependent diabetes mellitus presented to our clinic at 7 weeks of gestation for initial prenatal evaluation. Maintenance immunosuppressive therapy and prophylactic heparin anticoagulation was administered throughout the pregnancy, which was uneventful until 35 weeks gestation, at which time pre-eclampsia and premature preterm rupture of membranes prompted labor induction. The patient developed no evidence of acute or chronic hepatic rejection and no evidence of recurrent Budd-Chiari syndrome during the pregnancy or post-partum convalescence. Prudent use of prophylactic anticoagulation, close immunosuppressive monitoring, and periodic fetal and maternal surveillance are warranted in patients with previous orthotopic liver transplantation for idiopathic Budd-Chiari syndrome and may reduce risk of recurrence during pregnancy.     

Pleural invasion by peripheral bronchogenic carcinoma: assessment with three-dimensional helical CT

Cystic endometrial hyperplasia resembling that of normal early pregnancy was induced by the insertion of a silk suture into diestrous bitches. Intraluminal trauma (wire scratching) induced a similar but moderate change. Intraluminal olive oil and saline had little or no effect. Maternal decidual response in rodentia produced by mechanical means in progesterone-stimulated uteri in the absence little or no effect. Maternal decidual response in rodentia produced by mechanical means in progesterone-stimulated uteri in the absence of fertilized ova is termed Loeb's deciduoma. A similar response was created in progesterone-stimulated canine uteri by various physical means when compared to the pregnant contralateral horn.     

Petascale molecular dynamics simulation using the fast multipole method on K computer

In this paper, we report all-atom simulations of molecular crowding — a result from the full node simulation on the “K computer”, which is a 10-PFLOPS supercomputer in Japan. The capability of this machine enables us to perform simulation of crowded cellular environments, which are more realistic compared to conventional MD simulations where proteins are simulated in isolation. Living cells are “crowded” because macromolecules comprise ∼30% of their molecular weight. Recently, the effects of crowded cellular environments on protein stability have been revealed through in-cell NMR spectroscopy. To measure the performance of the “K computer”, we performed all-atom classical molecular dynamics simulations of two systems: target proteins in a solvent, and target proteins in an environment of molecular crowders that mimic the conditions of a living cell. Using the full system, we achieved 4.4 PFLOPS during a 520 million-atom simulation with cutoff of 28 Å. Furthermore, we discuss the performance and scaling of fast multipole methods for molecular dynamics simulations on the “K computer”, as well as comparisons with Ewald summation methods.     

Analysis of irreversible oxidation wave of adsorbed CO at Pt(1 1 1), Pt(1 0 0) and Pt(1 1 0) electrodes

The oxidation wave of CO preadsorbed at 50 mV on Pt(1 1 1), (1 0 0) and (1 1 0) electrodes in phosphate buffer solution of pH 3 was observed as a function of the sweep rate. The sweep rate dependence of the peak current and peak potential, as well as the form of the wave, were examined on the basis of the Gilman mechanism that the electron transfer from a complex consisting of CO and oxygen containing species is the rate-determining step. An electron transfer step from CO itself was excluded. The peak current and peak potential analyses and the wave simulation gave the same value for f, the change in the interaction energy during the formation of the activated complex from the reactants. f was sweep-rate and surface-structure dependent. The nature of f was discussed.Nomenclature symmetry factor - reversible work required to bring an adsorbed species from its standard state - µ electrochemical potential - electrode potential referred to the reversible hydrogen electrode - _p peak potential - _1/2 width at half height of the oxidation wave - (a) adsorbed state - f() mutual interaction energy of the activated complex inRT units - f(R) mutual interaction energy of the reactants in RT units - f f() –f(R) - i oxidation current density, mA cm^–2 - i _p peak current, mA CM^–2 - k rate constant - Q ₀ electric charge, mCcm^–2 - v sweep rate, m Vs^–1 This paper is dedicated to Professor Brian E. Conway on the occasion of his 65th birthday, and in recognition of his outstanding contribuion to electrochemistry.     

MR evaluation of the articular cartilage of the femoral head during traction. Correlation with resected femoral head

As a result of a high percentage of hypoactive upper poles of kidneys in traditional 99mTc-dimercaptosuccinic acid (DMSA) SPECT, a prospective study was conducted using 180 degrees acquisition technique compared with 360 degrees to minimize tissue attenuation. METHODS: Anterior 180 degrees, posterior 180 degrees and 360 degrees renal SPECT images were obtained simultaneously using a dual-head camera. Forty-one subjects without renal disease and 16 subjects with 21 cortical defects were included in this study. The total counts of the raw data in the anterior 180 degrees, posterior 180 degrees and full 360 degrees were calculated. Small regions of interest were drawn over the cortex of the kidney on coronal and reoriented sagittal slices. Quantitative evaluation of regional activity was performed on the same frames in all three acquisition methods. RESULTS: Comparison of the total renal counts between the anterior and posterior 180 degrees data showed reduced counts in the anterior 180 degrees data collection (P < 0.01). Visual evaluation of the reconstructed images from anterior 180 degrees, posterior 180 degrees and full 360 degrees data collection showed the best image uniformity in the posterior 180 degrees image. The upper/lower pole ratio in the posterior 180 degrees renal SPECT images increased significantly in comparison to full 360 degrees renal SPECT images (P < 0.01) and anterior 180 degrees SPECT images (P < 0.01). The renal defects were more clearly visualized in the posterior 180 degrees renal SPECT images than the full 360 degrees renal SPECT images. The defect/normal cortex ratios in the posterior 180 degrees renal SPECT images were much lower than those from the full 360 degrees SPECT images (P < 0.01) and those from the anterior 180 degrees SPECT images (P < 0.01). CONCLUSION: The posterior 180 degrees acquisition technique can avoid the problem of hypoactive upper pole and can be less time consuming in 99mTc-DMSA SPECT images. It also provides superior lesion contrast in the clinical evaluation of patients with renal scarring.     

Lateral electronic transport in short-period InAs/GaAs superlattices at the threshold of quantum dot formation

Temperature dependences of resistance at 0.7 K<T<300 K, the Hall and Shubnikov-de Haas effects in magnetic fields of up to 40 T, photoluminescence (PL), and morphology of a heterointerface (using an atomicforce microscope) of short-period InAs/GaAs superlattices were investigated. The investigations were carried out for a region of subcritical and critical thickness Q=2.7 monolayers (ML) of InAs. Upon exceeding the critical thickness, the self-organized growth of InAs quantum dots (QDs) set in. The formation of QD layers upon exceeding the critical thickness of InAs Q=2.7 ML is accompanied by a transition of conductivity from metallic to hopping. It is found that at InAs layer thicknesses of Q=0.33 ML and Q=2.0 ML, the PL intensities and electron mobilities in the structures have clearly pronounced maxima. Anisotropy of conductivity, which depends on the thickness of the deposited InAs layers, was observed.