UVA causes dysfunction of ETBR and BMPR2 in vascular endothelial cells, resulting in structural abnormalities of the skin capillaries.

Background: Capillary structural abnormalities cause skin disorders. Mottled redness, i.e.

Senescent cell removal via JAG1-NOTCH1 signalling in the epidermis.

Emerging evidence has pointed to the noxious effects of senescent cells in various tissues, and senescent cells in the epidermis are known to accumulate with age. We hypothesized that there is a mechanism by which senescent cells in the epidermis are preferentially removed and that the function of such removal mechanism declines as age increases. In this study, we investigated whether Notch signalling is involved in such senescent cell removal.

Generation of Rat Monoclonal Antibody to Detect Hydrogen Sulfide and Polysulfides in Biological Samples.

Hydrogen sulfide (HS) is endogenously produced by enzymes and via reactive persulfide/polysulfide degradation; it participates in a variety of biological processes under physiological and pathological conditions. HS levels in biological fluids, such as plasma and serum, are correlated with the severity of various diseases. Therefore, development of a simple and selective HS measurement method would be advantageous.

A liposomal formulation study of 2,7-dichlorodihydrofluorescein for detection of reactive oxygen species.

It is known that reactive oxygen species (ROS) are connected with various diseases, and many studies have examined redox conditions in the body. However, there is a problem with stability of ROS and selectivity of detection probe. In this study, we aimed to stabilize the detection probe, and have tried to encapsulate the probe in polyethyleneglycol (PEG)-modified liposomes.

A reliable and sensitive immunoassay for the determination of crustacean protein in processed foods.

Among food allergens, crustacea such as shrimps, crabs, and lobsters are a frequent cause of adverse food reactions in allergic patients. The major allergen has been identified as a muscular protein, tropomyosin. A novel sandwich enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of crustacean protein in processed foods was developed using the sample dilution buffer that is added to porcine tropomyosin.

Single GUV method reveals interaction of tea catechin (-)-epigallocatechin gallate with lipid membranes.

Tea catechins, which are flavonoids and the main components of green tea extracts, are thought to have antibacterial and antioxidant activity. Several studies indicate that lipid membranes are one of the targets of the antibacterial activity of catechins. Studies using a suspension of large unilamellar vesicles (LUVs) indicate that catechin causes gradual leakage of internal contents from LUVs.

Feasibility of simple chitosan sheet as drug delivery carrier.

Chitosan, a biodegradable and biocompatible polysaccharide, is a potentially useful material in various fields. We developed a simple chitosan sheet and examined the possibility of using an adriamycin-containing chitosan sheet as a drug carrier for controlled release. To prepare a carrier consisting only of chitosan, a chitosan suspension was subjected to acid-alkaline treatment, mixed with adriamycin, frozen and freeze-dried.

Stability of membrane potential in heart mitochondria: single mitochondrion imaging.

Mitochondrial membrane potential (delta psi(m)) plays an important role in cellular activity. Although delta psi(m) of intracellular mitochondria are relatively stable, the recent experiments with isolated mitochondria demonstrate that individual mitochondria show frequent fluctuations of delta psi(m). The current study is performed to investigate the factors that stabilize delta psi(m) in cells by observing delta psi(m) of individual isolated mitochondria with fluorescence microscopy.

Changes in the mutagenic and estrogenic activities of 17beta-estradiol after treatment with nitrite.

We determined the changes in the mutagenic and estrogenic activities of 17beta-estradiol after a nitrite treatment. Nitrite-treated 17beta-estradiol showed mutagenic activities toward Salmonella typhimurium strains TA 100 and TA 98. We confirmed that nitrite-treated 17beta-estradiol generated radicals from the results of an analysis of electron spin resonance.

Interaction of (+)-catechin with a lipid bilayer studied by the spin probe method.

The interaction of (+)-catechin with a lipid bilayer was examined by the spin probe method. The spin probe, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), was dissolved in an aqueous dipalmitoylphosphatidylcholine (DPPC) dispersion containing (+)-catechin. The temperature dependence of the TEMPO parameter was measured.

Spin probe study on the interaction of chitosan-derived polymer surfactants with lipid membrane.

Chitosan-derived polymer surfactants, sulfated N-acyl-chitosan (S-Cn-Chitosan), were synthesized and compared with commonly used low-molecular-weight surfactants, sodium dodecyl sulfate (SDS), dodecyltrimethyl ammonium chloride (DTAC), and octaethyleneglycol mono n-dodecyl ether (BL8SY), in their interaction with a lipid membrane using a spin probe method. A suspension of dipalmitoylphosphatidyl-choline (DPPC) spin-labeled strongly (10%) with a spin probe, 1-palmitoyl-2-(12-doxyl) stearoyl-phosphatidylcholine, was mixed with the surfactant solutions. The dissolution time of the DPPC membrane was estimated from the peak height change vs time, which was caused by the decrease in spin-exchange interaction.

Changes in the mutagenic and estrogenic activities of bisphenol A upon treatment with nitrite.

Bisphenol A (4,4'isopropylidenediphenol: BPA), an endocrine-disrupting chemical, is contained in food-packaging and can-coating agents as well as in dental sealants. Nitrite is present in vegetables, fish and tap water as an ingredient or contaminant, and also in human saliva. Here, we explored the possible generation of genotoxicity from the reactions of BPA and nitrite under acidic conditions, a situation simulating the stomach.

Synthesis of lipophilic poly-lauroyl-(+)-catechins and radical-scavenging activity.

Lipophilic catechins were synthesized to improve absorption into living bodies and obtain new antioxidants effective in lipid bilayers. The hydroxyl (OH) groups of (+)-catechin was acylated randomly using lauroyl chloride. The mixture was separated by preparative HPLC, and 3-lauroyl-, 3',4'-dilauroyl- and 3,3',4'-trilauroyl-catechins (3-LC, 3',4'-LC, and 3,3',4'-LC) were obtained, their structures being determined by (1)H NMR.

Repetitive transient depolarizations of the inner mitochondrial membrane induced by proton pumping.

Single mitochondria show the spontaneous fluctuations of DeltaPsim. In this study, to examine the mechanism of the fluctuations, we observed DeltaPsim in single isolated heart mitochondria using time-resolved fluorescence microscopy. Addition of malate, succinate, or ascorbate plus TMPD to mitochondria induced polarization of the inner membrane followed by repeated cycles of rapid depolarizations and immediate repolarizations.

Nitric oxide and effect of a radical scavenger N-tert-butyl-alpha-phenylnitrone on stroke in a rat model.

To characterize the role of nitric oxide (NO) in stroke, NO was measured using an in vivo microdialysis technique and electron spin resonance spectrometry in malignant stroke-prone spontaneously hypertensive rats (M-SHRSP), stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY). The brain dialysate NO level was higher in SHRSP than in WKY. NO was not detected in M-SHRSP hippocampus microdialysate after stroke except after the administration of N-tert-butyl-alpha-phenylnitrone (PBN).

ESR characterization of a novel spin-trapping agent, 15N-labeled N-tert-butyl-alpha-phenylnitrone, as a nitric oxide donor.

We previously found that one of the pharmacological effects of N-tert-butyl-alpha-phenylnitrone (PBN) is the release of nitric oxide (NO) under oxidative conditions. However, to confirm this hypothesis in vivo, NO released from PBN must be distinguished from NO produced in biological systems, and therefore we undertook the synthesis of PBN using labeled 15N to identify its corresponding 15NO in vivo. The properties were examined with an ESR spectrometer.

Detection of 2-deoxy-D-ribose radicals generated by the reaction with the hydroxyl radical using a rapid flow-ESR method.

ESR spectrum of the short-lived radicals derived from 2-deoxy-D-ribose by the reaction with the hydroxyl radical (HO*) was measured using a rapid flow method. A dielectric mixing resonator was used for the measurement, which made it possible to measure the highly sensitive ESR spectra of the radicals with a lifetime of the order of milliseconds. A complex spectrum was obtained and the spectral simulation was done to show that it was the superposition of the signals due to five radicals (I-V).

Kinetic analysis of the effect of (-)-epigallocatechin gallate on the DNA scission induced by Fe(II).

The DNA strand scission induced by Fe(II) in a citrate buffer solution and the effect of (-)-epigallocatechin gallate (EGCg) were kinetically analyzed. The rate of consumption of dissolved oxygen by Fe(II) in each of these solutions was measured and paralleled that DNA scission. Coordinated EGCg accelerated these reactions.

Protective effect of spin trap agent, N-tert-butyl-alpha-phenylnitrone on hyperoxia-induced oxidative stress and its potential as a nitric oxide donor.

We have previously suggested that the spin trap agent, N-tert-butyl-alpha-phenylnitrone (PBN) can function not only as an antioxidant but also as a nitric oxide (NO) donor. To characterize the pharmacological activities of PBN against oxidative damage, we examined the effect of PBN on NO generation under hyperoxic conditions. The formation of NO in mice exposed to 95% oxygen was determined using a NOx analyzer and electron spin resonance (ESR).