Fragmented platinum microcoils as embolization material. Preliminary evaluation in vivo

OBJECTIVES: To study the electromechanical activity of the normal ureter in 5 men and 4 women (mean age 39.4 +/- 10.8 years) scheduled for rectopexy due to rectal prolapse. The results of urinary tract investigations were normal. METHODS: During anesthesia for rectopexy, rectal mobilization necessitates ureteral exposure for protective reasons. One electrode was applied to each of the upper, middle, and lower third of the right ureter, and signals were registered for 30 minutes. Simultaneous recording of intraureteral pressure was performed. RESULTS: Slow waves, or pacesetter potentials (PPs), were recorded from the three electrodes. Identical readings for frequency, amplitude, and velocity of conduction were obtained from the three electrodes in the same ureter. Action potentials (APs) followed the PPs and were inconsistent and were associated with an intraureteral pressure increase (P < 0.001). No pressure elevation occurred with PPs. CONCLUSIONS: In contrast to PPs, APs seem to have a role in ureteral mechanical activity and might initiate ureteral peristalsis. The function of the PPs is unknown; they might pace the APs in terms of direction and frequency. The present study could characterize an electroureterographic pattern for the normal ureter. It is suggested that this pattern is changed in the various ureteral pathologic conditions and, thus, the electroureterogram be considered a useful investigative tool in ureteral disorders. However, the procedure in its present from is not applicable to clinical practice. Nevertheless, the present study might be of significance in explaining the mechanisms of ureteral motility and urinary bolus transport.     

Thermal fatigue and aging properties of water-impervious cable

On-core water impervious power cable has a water-impervious layer consisting of lead foil and a semiconducting plastic film. This layer is thermally bounded to the insulation shield of the cable core and prevents ingress of water to its interior. According to this design, the water-impervious layer is subjected to thermal expansion and contraction directly from the core and, as a result, thermal fatigue properties assume greater importance. Factors such as strain in the water-impervious layer, aging behavior of the lead foil, heat cycle behavior on the cable, and high-temperature behavior of composite tapes were investigated. Based on these results, it is estimated that the life of the on-core water-impervious layer is approximately 40 yrs     

Design and evaluation of radioactive acetylcholine analogs for mapping brain acetylcholinesterase (AchE) in vivo

For mapping brain acetylcholinesterase (AchE) in vivo, seven radioactive acetylcholine analogs, N-[14C]methylpiperidyl-3- and 4-acetates, propionates, isobutyrates, and 3-butyrate were newly synthesized and evaluated in mice. The esters readily entered the brain and were hydrolyzed into the hydrophilic metabolite, which was trapped. In brain homogenates, the esters showed a wide range of enzymatic reactivity (about 40-fold), and high specificity for AchE (more than 82%) except the butyrate. Intra-brain distribution of the esters reflected a pattern of AchE activity.     

Induction of apoptosis by ASK1, a mammalian MAPKKK that activates SAPK/JNK and p38 signaling pathways

Mitogen-activated protein (MAP) kinase cascades are activated in response to various extracellular stimuli, including growth factors and environmental stresses. A MAP kinase kinase kinase (MAPKKK), termed ASK1, was identified that activated two different subgroups of MAP kinase kinases (MAPKK), SEK1 (or MKK4) and MKK3/MAPKK6 (or MKK6), which in turn activated stress-activated protein kinase (SAPK, also known as JNK; c-Jun amino-terminal kinase) and p38 subgroups of MAP kinases, respectively. Overexpression of ASK1 induced apoptotic cell death, and ASK1 was activated in cells treated with tumor necrosis factor-alpha (TNF-alpha). Moreover, TNF-alpha-induced apoptosis was inhibited by a catalytically inactive form of ASK1. ASK1 may be a key element in the mechanism of stress- and cytokine-induced apoptosis.     

Mutation of p53 gene and genomic instability in testicular tumors

BACKGROUND: During the past decade, studies of human cancer have begun to yield molecular information on the identify of the multiple genetic changes in the development and progression of tumorigenesis. We investigated alterations of p53 and genomic instability in testicular tumors. MATERIALS AND METHODS: Polymerase chain reaction (PCR) single-strand conformation polymorphism was performed for analysis from exons 5 to 8 of p53 gene in 22 cases and PCR-microsatellite instability analysis using 8 microsatellite markers were conducted in 19 cases of testicular tumor. RESULTS: No mutations were noted for exons 5 to 8 of the p53 gene. Differences in unrelated microsatellites for tumor and corresponding normal DNA were detected in 5 of 19 (26.3%) cases examined. Alterations noted in more than 2 microsatellites were observed in 3 of 19 (15.8%) and categorized as replication error (RER) phenotype. Two of 7 (28.6%) seminomatous and 1 of 12 (8.3%) non-seminomatous testicular tumors patients showed RER. Two of 16 (12.5%) stage T1-3N0M0 and 1 of 3 (33.3%) stage T1-3N1-3M0-1 showed RER. CONCLUSIONS: Alterations in microsatellite instability may be involved in the development of testicular tumor.     

The steady state response of a Mindlin annular plate of varying thickness

The steady state response of an internally damped Mindlin plate of radially varying thickness to sinusoidally varying force is determined by the transfer matrix approach. The method is applied to free-clamped annular plates of linearly, parabolically and exponentially varying thickness, which are driven around the free outer edge or driven around a concentric circle of any radius; the driving-point impedance, transfer impedance and force transmissibility of the plates are calculated numerically, and the effects of the varying thickness on them are studied.     

Cellular immuno-PCR. Detection of a carbohydrate tumor marker

Carbohydrate tumor-antigens are important tumor markers for diagnosis and functional characteristics of human cancer cells. Detection of these carbohydrate tumor antigens on metastatic cancer cells in blood is a difficult task. We developed a highly sensitive method to detect a cell surface carbohydrate antigen using a hybrid technology referred to as cellular immuno-PCR. This technique uses the human monoclonal antibody (HumAb) L612, specific to a tumor-related antigen (ganglioside) GM3 that is expressed on the cell surface of human tumor cells and not normal cells. L612 coupled to a DNA oligonucleotide for exponential amplification by DNA polymerase chain reaction (PCR) can be used to enhance the detection signal. The DNA-HumAb conjugate was assessed for detection of a small number of human cancer cells after PCR amplification and Southern blot analysis. To assess the assay specificity human melanoma and other cancer cell lines, as well as healthy donor and melanoma patients, bloods were assessed. Cellular immuno-PCR requires < 1 ng/ml DNA-HumAb complex and was shown to have a detection level of < 10 cells in titration studies in which melanoma cells were diluted in 2 million healthy donor peripheral blood lymphocytes. The assay was shown to be very sensitive and could detect low levels of GM3 antigen expression by tumor cells. This novel approach for detecting a carbohydrate tumor antigen on tumor cells in blood provides a potential useful clinicopathological assay.     

Preparation of hybrid films of aluminosilicate nanofiber and conjugated polymer

We have demonstrated the preparation of hybrid films of aluminosilicate nanofiber (imogolite) and water-soluble poly(p-phenylene) (WS-PPP), which has sulfonate groups. The imogolite/WS-PPP hybrid gel could be prepared by mixing a solution of these two materials and subsequent centrifugation. The aluminol (AlOH) groups on the surface of imogolite would be protonated under acidic conditions to afford AlOH₂⁺ groups that can interact with sulfonate groups (SO₃^?) of WS-PPP. Based on this ionic interaction, a layer-by-layer (LBL) assembly was applied to fabricate the hybrid films of imogolite nanofibers and WS-PPP. The deposited amounts of WS-PPP and imogolite were measured by quartz crystal microbalance (QCM) measurements and scanning electron microscopy (SEM) observation. Atomic force microscopy (AFM) observation revealed that imogolite nanofibers were well networked in the LBL hybrid film.     

Hierarchical Power Distribution With Power Tree in Dozens of Power Domains for 90-nm Low-Power Multi-CPU SoCs

Hierarchical power distribution with a power tree has been developed. The key features are a power-tree structure with three power-tree management rules and a distributed common power domain implementation. The hierarchical power distribution supports a fine-grained power gating with dozens of power domains, which is analogous to a fine-grained clock gating. Leakage currents of a 1 000 000-gate power domain were effectively reduced to 1/4000 in multi-CPU SoCs with minimal area overhead     

Hyperbranched Polyglycerol‐Grafted Superparamagnetic Iron Oxide Nanoparticles: Synthesis,Characterization, Functionalization,Size Separation,Magnetic Properties,and Biological Applications

For biomedical application of nanoparticles, the surface chemical functionality is very important to impart additional functions, such as solubility and stability in a physiological environment, and targeting specificity as an imaging probe and a drug carrier. Although polyethylene glycol (PEG) has been used extensively, here, it is proposed that hyperbranched polyglycerol (PG) is a good or even better alternative to PEG. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared using a polyol method are directly functionalized with PG through ring‐opening polymerization of glycidol. The resulting SPION‐PG is highly soluble in pure water (>40 mg mL^?1) and in a phosphate buffer solution (>25 mg mL^?1). Such high solubility enables separation of SPION‐PG according to size using size exclusion chromatography (SEC). The size‐separated SPION‐PG shows a gradual increase in transverse relaxivity (r₂) with increasing particle size. For biological application, SPION‐PG is functionalized through multistep organic transformations (–OH → –OTs (tosylate) → –N₃ → –RGD) including click chemistry as a key step to impart targeting specificity by immobilization of cyclic RGD peptide (Arg‐Gly‐Asp‐D ‐Tyr‐Lys) on the surface. The targeting effect is demonstrated by the cell experiments; SPION‐PG‐RGD is taken up by the cells overexpressing α_vβ₃‐integrin such as U87MG and A549.