Application of a chronoamperometric measurement to the on-line monitoring of a lithium metal reduction for uranium oxide

Both a potentiometric and a chronoamperometric electrochemical technique have been applied in an attempt to develop an efficient method for an on-line monitoring of a lithium metal reduction process of uranium oxides at a high-temperature in a molten salt medium. As a result of this study, it was concluded that the chronoamperometric method provided a simple and effective way for a direct on-line monitoring measurement of a lithium metal reduction process of uranium oxides at 650 °C by the measuring electrical currents dependency on a variation of the reduction time for the reaction. A potentiometric method, by adopting a homemade oxide ion selective electrode made of ZrO₂ stabilized by a Y₂O₃ doping, however, was found to be inappropriate for an on-line monitoring of the reduction reaction of uranium oxide in the presence of lithium metal due to an abnormal behavior of the adopted electrodes. The observed experimental results were discussed in detail by comparing them with previously published experimental data.     

Long-term follow-up of cranial bone graft in dorsal nasal augmentation

A follow-up of 363 cranial bone grafts for nasal reconstruction is presented. The main indications for the surgery were congenital, posttraumatic, or postrhinoplasty deformity. The results were satisfactory in the vast majority of cases. The complications associated with the grafts and with the donor site are discussed, as are the methods to treat and prevent these complications from occurring.     

CDK4 down-regulation induced by paclitaxel is associated with G1 arrest in gastric cancer cells

Paclitaxel induces a cell cycle block at G2-M phase by preventing the depolymerization of microtubules and induces p53-independent apoptosis in many cancer cells. We observed that gastric cancer cells treated with paclitaxel have shown a cyclin-dependent kinase (CDK)4 down-regulation. This paclitaxel-induced CDK4 down-regulation resulted in a cell cycle arrest at G1-S phase. To confirm this observation, we prepared stable transfectants that overexpressed CDK4 and analyzed the cell cycle progression. Ectopic expression of CDK4 in SNU cells resulted in a release of paclitaxel-induced G1 arrest. The release of G1 arrest by enforced expression of CDK4 seems to make the cells more sensitive to paclitaxel-induced apoptosis. From this finding, we could then suggest that paclitaxel treatment induces both G1-S and G2-M blocks in the cell cycle progression of gastric cancer cells.     

A concise synthesis and in vitro cytotoxicity of new labdane diterpenes

A new series of labdane-related diterpenes have been synthesized from (-)-sclareol and assayed in vitro cytotoxicity against mouse and human cancer cells. A key intermediate, homodrimane and furanolabdane derivatives show good in vitro cytotoxicity comparable to those of mitomycin C and adriamycin.     

Effect of Combined Addition of Cu and Aluminum Oxide Nanoparticles on Mechanical Properties and Microstructure of Al-7Si-0.3Mg Alloy

In this study, an ultrasonic cavitation based dispersion technique was used to fabricate Al-7Si-0.3Mg alloyed with Cu and reinforced with 1 wt pct Al₂O₃ nanoparticles, in order to investigate their influence on the mechanical properties and microstructures of Al-7Si-0.3Mg alloy. The combined addition of 0.5 pct Cu with 1 pct Al₂O₃ nanoparticles increased the yield strength, tensile strength, and ductility of the as-cast Al-7Si-0.3Mg alloy, mostly due to grain refinement and modification of the eutectic Si and θ-CuAl₂ phases. Moreover, Al-7Si-0.3Mg-0.5Cu-1 pct Al₂O₃ nanocomposites after T6 heat treatment showed a significant enhancement of ductility (increased by 512 pct) and tensile strength (by 22 pct). The significant enhancement of properties is attributed to the suppression of pore formation and modification of eutectic Si phases due to the addition of Al₂O₃ nanoparticles. However, the yield strength of the T6 heat-treated nanocomposites was limited in enhancement due to a reaction between Mg and Al₂O₃ nanoparticles.     

Susceptibility of penicillin-susceptible and -resistant pneumococci to CFC-222, a new fluoroquinolone

Rotavirus (RV) strains infecting newborns often have unique neutralization antigens (P serotypes) on their outer capsids that are distinct from those found on RV strains that cause diarrhea in older children. We examined the hypothesis that unusual RV strains preferentially infect newborns because the newborns lack maternal neutralizing antibodies to these strains. To test this hypothesis, sera and saliva samples collected from neonates infected with 116E-like (P[11]G9) strains in the maternity ward of the All India Institute of Medical Sciences (AIIMS) hospital in New Delhi were tested for neutralizing antibodies against common RV strains and those infecting newborns and these titers were compared with those of newborns who did not become infected (controls). The infected neonates had significantly lower levels of cord blood neutralizing antibodies to 116E than the controls, suggesting that immunity to neonatal RV infection is acquired transplacentally through maternal antibodies. Further, this study confirmed the immunogenicity of the AIIMS neonatal strain 116E, a vaccine candidate, in its ability to evoke a potent RV-specific immunoglobulin A and neutralizing antibody response in serum and saliva among the infected babies. Our findings have important implications for the development of an effective RV vaccine. In India, where G9 strains are common in the community, the use of 116E as a vaccine, together with the rhesus tetravalent vaccine, may provide a broader protection against all the circulating RV serotypes, including serotype G9, which is not represented in the current rhesus RV tetravalent vaccine (G1-G4).     

CD28-independent, TRAF2-dependent costimulation of resting T cells by 4-1BB ligand

4-1BB ligand (4-1BBL) is a member of the tumor necrosis factor (TNF) family expressed on activated antigen-presenting cells. Its receptor, 4-1BB, is a member of the TNF receptor family expressed on activated CD4 and CD8 T cells. We have produced a soluble form of 4-1BBL using the baculovirus expression system. When coimmobilized on plastic with anti-CD3, soluble 4-1BBL induces interleukin (IL)-2 production by resting CD28+ or CD28- T cells, indicating that 4-1BBL can function independently of other cell surface molecules, including CD28, in costimulation of resting T cell activation. At low concentrations of anti-CD3, 4-1BBL is inferior to anti-CD28 in T cell activation. However, when 4-1BB ligand is provided together with strong TCR signals, then 4-1BBL and anti-CD28 are equally potent in stimulation of IL-2 production by resting T cells. We find that TNF receptor-associated factor (TRAF)1 or TRAF2 associate with a glutathione S-transferase-4-1BB cytoplasmic domain fusion protein in vitro. In T cells, we find that association of TRAF1 and TRAF2 with 4-1BB requires 4-1BB cross-linking. In support of a functional role for TRAF2 in 4-1BB signaling, we find that resting T cells isolated from TRAF2-deficient mice or from mice expressing a dominant negative form of TRAF2 fail to augment IL-2 production in response to soluble 4-1BBL. Thus 4-1BB, via the TRAF2 molecule, can provide CD28-independent costimulatory signals to resting T cells.     

Identification and characterization of novel antimicrobial decapeptides generated by combinatorial chemistry

Novel combinatorial libraries consisting of simplified amino acid sequences were designed to screen for peptides active against the Candida albicans membrane. A novel decapeptide, KKVVFKVKFK, that had a unique primary amino acid sequence was identified in this work. This peptide irreversibly inhibited the growth of C. albicans and showed a broad range of antibacterial activity but no hemolytic activity. Circular dichroism spectra revealed that the predominant secondary structure of this peptide strongly depended on the membrane-mimetic environments; the peptide preferred to form an amphipathic alpha-helical structure in the presence of 50% trifluoroethanol, while it preferred to adopt a distorted alpha-helical structure in the presence of sodium dodecyl sulfate micelles. Experiments in which dye was released from vesicles indicated that this novel antimicrobial peptide killed microorganisms through the action on the membrane as its primary target. Replacement of amino acids in this active decapeptide on the basis of information from the libraries could provide unique information about factors affecting its antimicrobial activity such as its secondary structure, net positive charge, and hydrophobicity.     

Inhibitory action of YJA20379, a new proton pump inhibitor on Helicobacter pylori growth and urease

The use of an episiotomy for vaginal delivery is a controversial topic in modern obstetrics. If one is done, however, correct technique of perineal trauma repair is important. The usual episiotomy has traditionally been closed with interrupted suture. The use of a less reactive material, e.g. polyglycolic acid (Dexon), seem to be suitable for subcutaneous skin closure and beneficial in terms of acute postpartum discomfort and healing. The comparison of healing and patient comfort parameters between interrupted and subcutis polyglycolic acid suture used for episiotomy repair after delivery was done. Patients had follow-up during hospital stay, and two months after delivery a self administered questionnaire was sent to all women who participated, enquiring about perineal pain, resumption of sexual intercourse and cosmetics of suture line. Of 52 patients who had repair with interrupted suture, 21 were lost to follow-up. Of 65 gravidas who had repair with subcutis suture, 23 were lost to follow-up. At the 3rd day postpartum examination, patients with subcutis sutures had significantly better healing. An inflammatory process was present in 2 of 52 patients with interrupted sutures comparable with 1 of 65 in the subcutis group, and a gaping wound in 0 of 52 and 1 of 65, respectively. Recovery of function, measured by resumption of sexual activity by 8 weeks, was demonstrated in 5 of 31 patients with interrupted sutures versus 24 of 42 patients who had subcutis sutures. Episiotomy repair with subcutis polyglycolic acid (Dexon) offers significant advantages over traditional interrupted suture, both in terms of wound healing and resumption of sexual activity.     

A family of gram-negative bacterial outer membrane factors that function in the export of proteins, carbohydrates, drugs and heavy metals from gram-negative bacteria

Differentiation of biliary epithelial cells from hepatic endodermal cells of the mouse embryo was examined with a special attention to the role of the connective tissue. When the whole liver primordium of the 9.5-day mouse embryo was cultured in vitro for 5 days, the endodermal cells differentiated into mature hepatocytes expressing carbamoylphosphate synthetase I (CPSI) and accumulating glycogen. Intrahepatic bile duct cells and connective tissue were poorly developed in this culture. However, when the hepatic endoderm was recombined with the 4-day embryonic chick lung mesenchyme and cultured in vitro, the endodermal cells differentiated into many ductal epithelial cells as well as mature hepatocytes with abundant connective tissue development. These results suggest that the ducts might be bile ducts, and that connective tissue is very important for bile duct development. In addition, this in vitro culture system might be useful for the study of mechanisms of bile duct differentiation and congenital biliary atresia.