Imaging Validation of Drug-Eluting Beads Transarterial Chemoembolization of Hepatocellular Carcinomas in Living Donor Liver Transplantation.

OBJECTIVE: The aim of this study is to determine whether post-transarterial chemoembolization imaging (computed tomography or magnetic resonance imaging) could accurately predict the tumors' necrosis on pathologic specimens. BACKGROUND: Transarterial chemoembolization with drug-eluting beads has been proven to be an effective way to bridge patients with hepatocellular carcinomas to liver transplantation. MATERIALS AND METHODS: From September 2012 to June 2017, 59 patients with a total of 78 hepatocellular carcinomas, who received transarterial chemoembolization with drug-eluting beads before liver transplantation in Kaohsiung Chang Gung Memorial Hospital, were included in the study. All patients and hepatocellular carcinomas have pre-transarterial chemoembolization and post-transarterial chemoembolization images (computed tomography or magnetic resonance imaging) and pathological findings for correlation. Tumor response was evaluated according to modified Response Evaluation Criteria in Solid Tumors. The ranges of necrotic percentage are 100%, 91-99%, 51-90%, and <50%. RESULTS: The accuracy rate between the imaging and pathology correlation was 40% for computed tomography and 42% for magnetic resonance imaging. The recurrent rate of the complete respond group is 11.5%, the partial respond group is 16.0%, and the stationary group is 28.6%. CONCLUSION: Computed tomography and magnetic resonance imaging sensitivity is not satisfactory for microscopic evaluation of residual tumors after transarterial chemoembolization with drug-eluting beads. However, survival is good after liver transplantation no matter what the microscopic findings were.

Real-time PCR assay with high resolution melting for EGFR and BIM mutation of lung cancer.

OBJECTIVE: To establish and develop a reliable and simple Real-time PCR assay with high resolution melting (Real-time PCR-HRM) method for detection epidermal growth factor (EGFR) and BIM mutation of lung cancer and looking for effective targeted drugs to control lung cancer. PATIENTS AND METHODS: A total of 6858 participants (2538 cases with lung cancer and 4275 healthy controls who took part in the study by doing the physical examination in Shanghai Xuhui community) were recruited in the study. Clinical characteristics and 5 ml peripheral blood were collected from each participant, and the DNA has been extracted, which were determined the EGFR and BIM mutation by Real-time PCR-HRM. Data were recorded and Statistical analyses. RESULTS: All samples completed the study. BIM deletion polymorphism was no related with age, sex, and smoking or EGFR mutation. CONCLUSIONS: There were no relations among BIM deletion polymorphism, EGFR mutation or lung cancer risk. HRM is a novel procedure and provides rapid, sensitive, specific and simultaneous detection for gene mutation of cancer patients for predicting the efficacy of targeted therapy.

Conformational change, aggregation and fibril formation induced by detergent treatments of cellular prion protein.

The conversion of protease-sensitive prion protein (PrP-sen) to a high beta-sheet, protease-resistant and often fibrillar form (PrP-res) is a central event in transmissible spongiform encephalopathies (TSE) or prion diseases. This conversion can be induced by PrP-res itself in cell-free conversion reactions. The detergent sodium N-lauroyl sarkosinate (sarkosyl) is a detergent that is widely used in PrP-res purifications and is known to stimulate the PrP-res-induced conversion reaction. Here we report effects of sarkosyl and other detergents on recombinant hamster PrP-sen purified from mammalian cells under oxidizing conditions that maintain the single native disulfide bond. Low concentrations of sarkosyl (0.001-0.1%) induced aggregation of PrP-sen molecules, increased light scattering, altered fluorescence excitation and emission spectra, and enhanced the proportion of beta-sheet secondary structure according to circular dichroism and infrared spectroscopies. An enhancement of beta-sheet content was also seen with 0.001% sodium dodecyl sulfate (SDS) but not several other types of detergents. Electron microscopy revealed that sarkosyl induced the formation of both amorphous and fibrillar aggregates. The fibrils appeared to be constructed from spherical bead-like protofibrils. Neither TSE infectivity nor the characteristic partial proteinase K resistance of PrP-res was detected in the sarkosyl-induced PrP aggregates. We conclude that certain anionic detergents can disrupt the conformation of PrP-sen and induce high beta-sheet aggregates that are distinct from scrapie-associated PrP-res in terms of protease-resistance, infrared spectrum and infectivity. These results reinforce the idea that not all high-beta aggregates of PrP are equivalent to the pathologic form, PrP-res.

Inhibition of interactions and interconversions of prion protein isoforms by peptide fragments from the C-terminal folded domain.

The formation of protease-resistant prion protein (PrP-res or PrP(Sc)) involves selective interactions between PrP-res and its normal protease-sensitive counterpart, PrP-sen or PrP(C). Previous studies have shown that synthetic peptide fragments of the PrP sequence corresponding to residues 119-136 of hamster PrP (Ha119-136) can selectively block PrP-res formation in cell-free systems and scrapie-infected tissue culture cells. Here we show that two other peptides corresponding to residues 166-179 (Ha166-179) and 200-223 (Ha200-223) also potently inhibit the PrP-res induced cell-free conversion of PrP-sen to the protease-resistant state. In contrast, Ha121-141, Ha180-199, and Ha218-232 were much less effective as inhibitors. Mechanistic analyses indicated that Ha166-179, Ha200-223, and peptides containing residues 119-136 inhibit primarily by binding to PrP-sen and blocking its binding to PrP-res. Circular dichroism analyses indicated that Ha117-141 and Ha200-223, but not non-inhibitory peptides, readily formed high beta-sheet structures when placed under the conditions of the conversion reaction. We conclude that these inhibitory peptides may mimic contact surfaces between PrP-res and PrP-sen and thereby serve as models of potential therapeutic agents for transmissible spongiform encephalopathies.

Sulfated glycans and elevated temperature stimulate PrP(Sc)-dependent cell-free formation of protease-resistant prion protein.

A conformational conversion of the normal, protease- sensitive prion protein (PrP-sen or PrP(C)) to a protease-resistant form (PrP-res or PrP(Sc)) is commonly thought to be required in transmissible spongiform encephalopathies (TSEs). Endogenous sulfated glycosaminoglycans are associated with PrP-res deposits in vivo, suggesting that they may facilitate PrP-res formation. On the other hand, certain exogenous sulfated glycans can profoundly inhibit PrP-res accumulation and serve as prophylactic anti-TSE compounds in vivo. To investigate the seemingly paradoxical effects of sulfated glycans on PrP-res formation, we have assayed their direct effects on PrP conversion under physiologically compatible cell-free conditions. Heparan sulfate and pentosan polysulfate stimulated PrP-res formation. Conversion was stimulated further by increased temperature. Both elevated temperature and pentosan polysulfate promoted interspecies PrP conversion. Circular dichroism spectropolarimetry measurements showed that pentosan polysulfate induced a conformational change in PrP-sen that may potentiate its PrP-res-induced conversion. These results show that certain sulfated glycosaminoglycans can directly affect the PrP conversion reaction. Therefore, depending upon the circumstances, sulfated glycans may be either cofactors or inhibitors of this apparently pathogenic process.

Effect of the content of ammonium dichromate in dichromated gelatin on Cr 2P3/2 X-ray photoelectron spectroscopy.

The effect of the content of (NH(4))(2)Cr(2)O(7) in dichromated gelatin (DCG) on the binding energy of the Cr 2P(3/2) level was studied with x-ray photoelectron spectroscopy. It was found that the binding energy of the Cr 2P(3/2) level of chromium in DCG is lower than that of pure ammonium dichromate. When the content of (NH(4))(2)Cr(2)O(7) is not greater than 1%, the chromium in DCG has only one state, near 577.5 eV; when this content is between 1% and 20%, the chromium in DCG has two states, near 577.5 and 579.1 eV. The relative contents of these two states change with the content of (NH(4))(2)Cr(2)O(7). As the (NH(4))(2)Cr(2)O(7) content increases, the relative content of the state near 577.5 eV decreases almost linearly, but its absolute content first increases, then reaches a maximum at ~10% (NH(4))(2)Cr(2)O(7), and finally decreases. In addition, the absolute content of the state near 577.5 eV changes very slowly between 5% and 15% (NH(4))(2)Cr(2)O(7). According to these experimental results and holography data reported in the literature, it is inferred that the chromium of the state near 577.5 eV is the chromium that forms the latent image center after exposure and then forms the hologram after development. As a result the basis for the optimum content of (NH(4))(2)Cr(2)O(7) is found, and an approach to increasing sensitivity is suggested through this experiment.

Mechanism of hologram formation in dichromated gelatin with x-ray photoelectron spectroscopy.

The mechanism of hologram formation in dichromated gelatin is studied from all aspects with x-ray photoelectron spectroscopy (XPS). It is indicated that the Cr 2p(3/2) XPS spectrum of chromium used for hologram formation shows the property of exhibiting a continuous spectrum during the process of dichromated-gelatin hologram formation. By means of curve fitting and drawing a comparison between the obtained spectra and those of some standard substances, it is found that during the process of hologram formation the valence of chromium used for hologram formation changes from Cr6+ to a quasi-trivalent state to Cr4+, and finally to Cr3+. Accordingly, the corresponding compound experiences a change from (NH4)2Cr2O7 to the transient state close to the feature of Cr(OH)3 to CrO2, and finally to Cr3+, cross linking with the gelatin. The essence of the chemical change at different stages of the process of hologram formation was found, and so the present mechanism, which is determined with comparatively abundant proof, should replace previously reported mechanisms, which were too simple, varied, and sometimes even mutually contradictory. According to the experimental results and the fact that a solid-film reaction, which differs from that of the liquid-phase reaction, was studied, possible chemical-reaction equations of the process of hologram formation are established. This becomes the basis for explaining previous findings and expanding further research.