A Study on the Reactive Compatibilization of a PBT/LCP Blend: Catalyst Effect

The in situ compatibilization of poly(butylene terephthalate) (PBT) with liquid crystalline polymer (LCP) via catalyzed transesterification reaction was examined through thermal, rheological, morphological and mechanical studies. The addition of catalyst, dibutyltindilaurate, was found to promote the transesterification between PBT and LCP. Maintenance of high vacuum environment was required to produce the high molecular weight copolymers in the reactor, which, acting at the interface, diminished the size of the dispersed phase (LCP) and enhanced interfacial adhesion that led to an early increase of the flexural strength. Flexural strength was reduced after long time reaction due to the chain scission. Transesterification confirmed by NMR spectroscopic analysis played a major role in the interchange process.

Nm23 expression in human gastric cancers - possible correlation of nm23 with lymph-node metastasis

In order to elucidate the relationship between nm23 and metastasis in human gastric cancers, we analyzed gene and protein expression of nm23-H1 using Northern blot and immunohistochemical techniques. nm23-H1 gene expression was identified in 17 out of 19 gastric cancer tissues. The signals in the tumor tissues presenting regional lymph node metastasis seem to be lower than those in the tumor tissues without regional lymph node metastasis, suggesting a role of nm23-H1 in the regional lymph node metastasis in the gastric cancers. However, the protein expression detected immunohistochemically was not correlated to the gene expression, partly because of difficulty in quantifying the amount of protein. Expression of the nm23-H1 gene as well as the nm23-H1 protein in the tumor tissues was higher than those in the corresponding normal mucosae. This suggests a linkage of nm23-H1 in the process of the gastric cancer progression. We also analyzed the sequence abnormalities of the nm23-H1 gene in the gastric cancer tissues using a direct sequencing technique, no mutations were observed.

Retinyl retinoate, a novel hybrid vitamin derivative, improves photoaged skin: a double-blind, randomized-controlled trial

BACKGROUND

All-trans-retinoic acid (RA) and all-trans-retinol (ROL) are not widely used as anti-wrinkle agents due to their irritancy and photo-stability, respectively. Therefore, the safety and photo-stability in the development of RA or ROL derivatives have been an important issue.

AIM

To identify the efficacy of retinyl retinoate as an anti-aging agent of cosmetics in treating females over 30 years old with periorbital wrinkles.

METHODS

The clinical study was a prospective, double-blind, randomized, and controlled study with a total of 11 Korean women. At every 4 weeks, the effectiveness was assessed with a global photodamage score, photographs, and image analysis using replicas and visiometers. The dermal distance and intensity was also evaluated using Dermascan C.

RESULTS

A statistically significant improvement in facial wrinkles (P<0.05) in eleven volunteers was observed in a clinical trial. The successive application of 0.06% retinyl retinoate cream for 3 months showed decreased depth and area of wrinkles in comparison with 0.075% retinol cream. The visual wrinkle improvement and the maximum roughness improvement rate (R2) for retinyl retinoate cream were 22% higher than that of retinol cream after 12 weeks. A statistically significant increase was observed after 8 and 4 weeks for dermal distance and dermal intensity, respectively (P<0.05).

CONCLUSIONS

Retinyl retinoate had characteristic features of new anti-aging agents, and effectively improved facial wrinkle conditions.

Ethanol-induced DNA damage and the expression of repair-related molecules in human gastric carcinoma AGS cells with use of an acid pump antagonist and proton pump inhibitor

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Background: Proton pump inhibitor (PPI) inhibits gastric acid secretion by strongly suppressing H + / K +- ATPase of parietal cells and is a major drug for peptic ulcers and gastroesophageal reflux. Recently it was reported that PPI has antioxidant and anti- inflammatory effects as well as a powerful acid inhibitory effect. To analyze the DNA repair capacity from the antioxidant effect of acid pump antagonist (Revanex-RN) and proton pump inhibitor (Omeprazole-OP), this study examined ethanol-induced DNA damage and the expression of repair related molecules in human gastric cancer AGS cells pretreated with an acid pump antagonist and a proton pump inhibitor.

Methods: AGS, a human gastric cancer cell line was obtained from ATCC, was treated with ethanol (0, 2, 4, 6, 8, 10%) during 1hr. MTT and Comet assay were performed to evaluate ethanol-induced DNA damage. The optimum concentration of ethanol which caused DNA damage was established. And AGS cells were cultured in proper concentration of RN or OP overnight. Then, these cells were treated with 5% ethanol during 1hr. DNA damage and recovery were represented the value of Olive tail moment in comet assay. Western blot was also performed to detect expression of DNA polymerase beta, APE/ref-1, PCNA, and GADD45.

Results: The DNA damage of AGS cell depended upon ethanol concentration distinctly. Damaged cells showed up recovered tendency in the group treated with low dose RN or OP. In addition, DNA repair enzymes including DNA polymerase beta and APE/ref-1 which were associated with mechanism of base excision repair (BER) were increased. A relevant protein such as GADD45 was also increased significantly.

Conclusions: PPI has capacity to recover damaged DNA, which is associated with increased expression of GADD45 directly. Therefore, PPI offers cancer prevention by reducing the level of DNA damage in the gastric mucosa. GADD45 is also likely to suggest that it could be used a major factor on the injury mechanism and an indicator of mucosal damage in stomach. Moreover, RN, an acid pump antagonist is expected to have the higher safety compared to the existing PPIs and considered to be equal to PPIs in terms of anti-cancer effect.

No significant financial relationships to disclose.

Characterization of the Drosophila melanogaster retinin gene encoding a cornea-specific protein

Two-dimensional analysis of head extracts from Drosophila melanogaster identified the four eye-specific protein spots corresponding to the retinin protein. The retinin protein spots were specifically stained with phosphoprotein-specific dye, suggesting that the retinin protein undergoes post-translational modification by phosphorylation. Northern blot analysis showed that the retinin gene begins to be expressed during the late stage of puparium formation during development. Analysis of the N-terminal sequence and expression of the retinin gene in S2 suggest that retinin is a secretory protein. Transgenic flies with knockdown expression of the retinin gene by RNA interference (RNAi) were established. However, no significant phenotypic changes in eye structure or phototransduction were observed in the transgenic flies. Western blot analysis and immunohistochemical studies of D. melanogaster eyes suggest that retinin is a cornea-specific protein.

Radiosurgery for arteriovenous malformations with gamma-knife: a multivariate analysis of factors influencing the complete obliteration rate

Seventy-two patients with arteriovenous malformations (AVMs) were treated with gamma-knife and subsequently analyzed to determine what factors influenced the obliteration of AVMs. The volume of nidi ranged from 0.3 to 21.7 ml (mean 3.9 ml) and the marginal dose ranged from 9 to 31.5 Gy (mean 21.4 Gy). The cumulative obliteration rates of all cases were 41% at 2 years, 67% at 3 years, and 89% at 4 years. Multivariate analysis demonstrated that only the two variables of flow rate (P = 0.020) and dose planning with axial MRI (P = 0.045) had correlation with the obliteration rate. Other variables such as size, marginal dose, and embolization had no statistical correlation with the obliteration rate. It may be very important to evaluate the AVM flow rate to predict the effect of gamma-knife radiosurgery on AVMs, even when the nidi volumes are small.

Effect of zoledronic acid on bone loss by letrozole

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Background: The aromatase inhibitors cause bone loss by estrogen depletion. Zoledronic acid (ZA) can prevent bone mineral density (BMD) loss associated with the use of aromatase inhibitors. Accordingly interest has arisen in measuring surrogate markers of bone resorption to monitor the response of treatment of BMD loss in place of radiologic assessment. This study was designed to determine whether ZA would prevent bone loss that is known to occur with letrozole and identified surrogate markers of bone resorption in an animal model. Methods: In ovariectomized or sham-operated rat, we administrated ZA and letrozole to 5 different groups including: a sham operation control group (OC), a group in which an ovariectomy was performed followed by saline administration (OS), an ovariectomy with ZA treatment group (OZ), an ovariectomy with letrozole treatment group (OL) and an; ovariectomy with ZA and letrozole combined treatment group (OZL). The levels of serum osteocalcin, serum bone alkaline phosphatase (BALP), serum calcium and urine N-telopeptide (NTX) and BMD were estimated and compared at the same periods for each group. The distinct microscopic findings of proximal tibia at week sixteen were also compared. Results: Significantly intense increment of BDM in the OZ group and the OZL group and lower increment in the OL group were valued in correlation to the OS group, 31.3%, 35.0%, 10.5% and 13.0% respectively. Serum osteocalcin levels and urine calcium levels were close to each group. Serum calcium levels and BALP levels were relatively lowering in the OZ group and the OZL group than other group. Meaningfully lower levels of urine NTX were measured in the OZ group and the OZL group, 6.6% and 16.5% respectively. In the OL group levels of urine NTX were rise of 55.9%. Less cancellous bone loss and increase bone trabeculae were noted in the microscopic findings of tibia. Conclusions: The combination treatment with ZA and letrozole are effective in the inhibition of bone resorption and in the maintenance of BMD. Measurement of serum osteocalcin, urine NTX, and BMD, levels are recommended as surrogate markers for determining the response for the treatment of bone loss.

No significant financial relationships to disclose.

Application of mulch for treating metals in urban runoff: batch and column test

Among the many methods available for the removal of heavy metals in urban nonpoint source pollution (NSP), adsorption has been shown to be an economically feasible alternative. To adsorb the amount of heavy metals in runoff, filtration of runoff through a specially constructed filter system is one possible treatment method. The mulch layer in a specially constructed filter system functions through adsorptive-filtration, where some pollutants are immobilised through sorption and some pollutants associated with suspended solids are immobilised through filtration. Therefore, the major interest of this study was to investigate the possibility of utilising mulch for the adsorption of heavy metals such as cadmium, copper, lead and zinc for a solution typical of those found in urban runoff using the flask-type adsorption batch tests and laboratory column tests. From the equilibrium sorption batch tests, it was observed that the adsorption of heavy metals on mulch with the same initial concentrations of metals in the solution decreased in the order Pb(II) > Cu(II) > Zn(II) > Cd(II) regardless of changes in pH. In column tests, the breakthrough curves for various heavy metals' adsorption by mulch showed that the binding strength of the following metal ions onto mulch was as follows: Pb(II) > Cu(II) > Zn(II) > Cd(II).

Origin of nonlinear transport across the magnetically induced superconductor-metal-insulator transition in two dimensions

We have studied the effect of perpendicular magnetic fields and temperatures on nonlinear electronic transport in amorphous Ta superconducting thin films. The films exhibit a magnetic field-induced metallic behavior intervening the superconductor-insulator transition in the zero temperature limit. We show that the phase-identifying nonlinear transport in the superconducting and metallic phases arises from an intrinsic origin, not from an electron heating effect. The nonlinear transport is found to accompany an extraordinarily long voltage response time.

Formation, manipulation, and elasticity measurement of a nanometric column of water molecules

Nanometer-sized columns of condensed water molecules are formed by an atomic-resolution force microscope operated in ambient conditions. An unusual stepwise decrease of the force gradient associated with the ultrathin water bridge in the tip-substrate gap is observed during its stretch, exhibiting regularity in step heights (approximately 0.5 N/m) and plateau lengths (approximately 1 nm). Such "quantized" elasticity is indicative of an atomic-scale stick slip at the tip-water interface. A thermodynamic-instability-induced rupture of the water meniscus (5 nm long and 2.6 nm wide) is also found. This work opens a high-resolution study of the structure and interface dynamics of a nanometric aqueous column.

Effect of CIDR-based protocols for timed-AI on the conception rate and ovarian functions of Japanese Black beef cows in the early postpartum period

Our objectives were to compare: (1) conception rates (in early postpartum Japanese Black beef cows) to timed-artificial insemination (timed-AI) among Ovsynch and Ovsynch plus CIDR protocols, and a protocol that used estradiol benzoate (EB) in lieu of the first GnRH of the Ovsynch plus CIDR; and (2) the effects of these protocols on blood concentrations of ovarian steroids. Cows in the control group (Ovsynch; n=35) underwent a standard Ovsynch protocol (GnRH analogue on Day 0, PGF(2 alpha) analogue on Day 7 and GnRH analogue on Day 9), with timed-AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the Ovsynch+CIDR group (n=31) received a standard Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Cows in the third treatment group (EB+CIDR+GnRH; n=41) received 2mg of EB on Day 0 in lieu of the first GnRH treatment, followed by the same treatment as in the Ovsynch+CIDR protocol. The conception rate tended to be greater in the Ovsynch+CIDR group (67.7%, P<0.15) and was greater in the EB+CIDR+GnRH (73.2%, P<0.05) and CIDR-combined (both CIDR-treated groups were combined) groups (70.8%, P<0.05) than in the Ovsynch group (48.6%). Plasma progesterone concentrations were higher on Day 7 (P<0.01) and lower on Days 14, 17 and 21 (P<0.001) in the CIDR-combined group than in the Ovsynch group. Plasma estradiol-17beta concentrations were higher on Day 7 in the Ovsynch group of non-pregnant cows than in the CIDR-combined group of non-pregnant cows and in an all-combined group (all treatment groups combined) of pregnant cows (P<0.01). Furthermore, estradiol-17beta concentrations were lower on Day 9 in the Ovsynch and CIDR-combined groups of non-pregnant cows than in the all-combined group of pregnant cows (P<0.05). In conclusion, both protocols using CIDR improved conception rates following timed-AI in early postpartum suckled Japanese Black beef cows relative to the Ovsynch protocol. Treatment with a CIDR may prevent early maturation of follicles observed in non-pregnant cows treated with the Ovsynch protocol, by maintaining elevated blood progesterone concentrations until PGF(2 alpha) treatment.

Use of sodium transfer tissue biosensor (STTB) for monitoring of marine toxic organism

A highly sensitive sodium (Na+) transfer tissue biosensor (STTB) was designed using a frog bladder membrane to measure paralytic shellfish poisons (PSP). The STTB consists, of a Na+ electrode covered by the membrane, which was then integrated into a flow-through system for continuous measurements. In the absence of Na+ channel blocker, active transfer of Na+ occurred from inside to outside across the frog membrane. When the STTB was used to measure the Na+ -dependent dissociation of PSP, it was able to detect PSB at a level contained in a single cell. However, 5 fg or higher (100 cells or more) is needed for accurate and reproducible measurements. The toxicity obtained by the STTB was significantly correlated (r = 0.9449) to that determined by the HPLC. Therefore, the simple method of the STTB can be used not only to detect a low level PSP in toxic plankton populations, but also to monitor poisons in shellfish.