Electron Spin Resonance Spectroscopy ; Magnetic Resonance Spectroscopy ; Models, Molecular ; Protein Structure, Tertiary ; Proteins ; chemistry

OBJECTIVESTo evaluate the diagnostic value of arterial spin labeling (ASL) technology in newborns with hypoxic ischemic encephalopathy (HIE).

METHODSeven full-term newborn infants without any history of asphyxia and other nervous system diseases were selected as the control and 33 full-term newborn infants were assigned into HIE group. The patients in HIE group were further divided into three subgroups (19 cases of mild, 6 cases of moderate and 8 cases of severe HIE) based on their clinical diagnosis. The control group and HIE group were examined with GE Signa EXCITE HD 3.0T superconducting MRI scanner with a head phase array coil. Both groups were scanned with conventional axial MRI (T1FLAIR, T2WI and T2FLAIR), 1HMRS (PRESS sequence) and ASL (FAIR). Original images of 1HMRS and ASL were processed by Functool software of ADW 4.3 workstation. ASL perfusion images were observed and the signal intensity values of the region of interest (bilateral gray, white matter and basal ganglia) of the two groups were quantitatively measured, and mean value were calculated and compared between groups. Statistical analysis was performed with SPSS 13.0 software, and statistically significant difference was set at P < 0.05.

RESULTThe perfusion images of two groups were obtained perfectly. The signal intensity values of bilateral gray, white matter and basal ganglia of control group were 125.34 ± 11.76, 73.42 ± 11.67 and 173.65 ± 15.49, respectively and there was a statistically significant difference between the different areas. The signal intensity values of bilateral gray, white matter and basal ganglia of HIE group were 153.47 ± 11.72, 71.35 ± 10.37 and 217.13 ± 12.51, respectively. There was a statistically significant difference (P < 0.05) in the average signal intensity value of gray matter and basal ganglia, but there were no statistically significant difference (P > 0.05) in white matter between the two groups.

CONCLUSIONASL Perfusion technique can assess HIE comprehensively and accurately. Furthermore, it can evaluate the brain damage of hypoxic ischemia. The results provide a strong basis for clinical treatment.

Electron Spin Resonance Spectroscopy ; Glycerol ; chemistry ; Mesylates ; chemistry ; Muramidase ; chemistry ; Protein Structure, Tertiary ; Proteins ; chemistry ; Spin Labels ; Temperature ; Viscosity

This article describes the preparation of the N-tert-butyl-alpha-phenylnitrone (PBN) liposomes and their related characteristics. The PBN liposomes were prepared by film dispersion-supersonic method and the formula of liposomes was optimized by orthogonal uniform design. RP-HPLC was used to qualify the amount of PBN that entered into the hepatoma cells. Necrosis rate was also investigated by fluorescence activated cell sorter (FACS) after PBN liposomes transfection. Result showed that the mean particle size, entrapment efficiency, and polydispersity of the resulting PBN-liposome were 137.5 nm, 71.52% and 0.286, respectively. PBN liposomes can enter into the tumor cell stably and they have higher affinity to hepatoma cell compared with free PBN resulting in a higher necrosis rate after transfection. These results provide a potential method for early diagnosis and treatment of cancer using specific spin trapping probe targeting tumor cells.
Carcinoma, Hepatocellular ; pathology ; Cyclic N-Oxides ; chemistry ; Electron Spin Resonance Spectroscopy ; Humans ; Nanoparticles ; chemistry ; Spin Labels ; Spin Trapping ; methods ; Tumor Cells, Cultured

Early detection and removal of adenomatous polyps can prevent the development of colorectal cancer. However, it is fairly common—up to 20%—for polyps to be undetected in a colonoscopy due to poor visualization of the proximal aspect of colonic folds and anatomical flexures. To overcome these limitations, many new endoscopes and accessories have been developed. A wide-angle colonoscopy did not improve the detection of adenoma compared with the standard colonoscopy. An extra-wide angle and Retroview colonoscopies showed a significantly lower miss rate of polyps in the colon model. However, clinical trials are mandatory in the future. The recently introduced full spectrum endoscopy system showed a significantly higher adenoma detection rate than the standard forward-viewing colonoscopy. In accessories, The cap-assisted colonoscopy showed only a marginal or no benefit on the detection of polyps and adenomas. In contrast, a colonoscopy with Endocuff, EndoRings, and G-eye have showed significantly lower adenoma miss rates. The Third Eye, which provides additional retrograde viewing, has revealed a significant improvement in the detection of adenoma and polyp. However, the Third Eye Retroscope was limited by its deployment through the working channel of the scope. Recently, the Third Eye Panoramic cap, which was designed to overcome the limitation of the Third Eye Retroscope, was introduced. In the future, this would be needed to evaluate the effectiveness, efficiency and safety for these new colonoscopies and accessories.
Adenoma ; Adenomatous Polyps ; Colon* ; Colonic Neoplasms* ; Colonoscopy* ; Colorectal Neoplasms ; Electron Spin Resonance Spectroscopy ; Endoscopes ; Endoscopy ; Polyps

In this review, we provide information on hydroxyl radical generation, trapping and detection methods, including electron spin resonance (ESR), electrochemistry detection (ECD), fluorescence detection, UV detection, chemoluminescence and mass spectrometry (MS). In addition, the advantages and disadvantages of the above methods were discussed.
Chromatography, Liquid ; methods ; Electron Spin Resonance Spectroscopy ; methods ; Electrophoresis, Capillary ; methods ; Hydroxyl Radical ; analysis ; chemistry ; Luminescent Measurements ; methods ; Mass Spectrometry ; methods ; Spectrophotometry, Ultraviolet ; methods ; Spin Trapping ; methods

In this study, antioxidant and free radical scavenging activities of the natural antioxidative compound, pyrogallol-phloroglucinol-6,6'-bieckol (PPB) isolated from brown algae, Ecklonia cava was assessed in vitro by measuring the radical scavenging activities (DPPH, alkyl, hydroxyl, and superoxide) using electron spin resonance (ESR) spectrometry, intracellular reactive oxygen species (ROS) scavenging activity, and DNA damage assay. According to the results of these experiments, the scavenging activity PPB against difference radicals was in the following order: DPPH, alkyl, hydroxyl, and superoxide radicals (IC50; 0.90, 2.54, 62.93 and 109.05 microM). The antioxidant activities of PPB were higher than that of the commercial antioxidant, ascorbic acid. Furthermore, PPB effectively inhibited DNA damage induced by H2O2. These results suggest that the natural antioxidative compound, PPB, can be used by the natural food industry.
Ascorbic Acid ; DNA Damage ; Electron Spin Resonance Spectroscopy ; Food Industry ; Phaeophyta ; Reactive Oxygen Species ; Spectrum Analysis ; Superoxides

OBJECTIVE: To observe the changes of free radicals in the cochlea of guinea pigs after noise exposure directly using electron spin resonance (ESR) technology. METHOD: Forty-two guinea pigs as experimental group were given (125 +/- 1) dB SPL noise exposure for 2 hours, and then investigated auditory function immediately, at 2, 6, 12, 24, 48 and 72 hour. After ABR examinations, 21 animals decollated and extracted cochlea immediately and then placed the cochleas to liquid nitrogen for deep freezing and measuring free radicals using ESR technology. Another 21 animals observed hair cells morphology by AgNO3 staining. Meantime, 6 animals without noise exposure were served as negative control group. RESULT: A few free radicals were detected in the cochlea at control group and the relative value of free radicals were (21.68 +/- 1.27) dB SPL. After noise exposure, the relative value of free radicals increased obviously and achieved to the max of (147.01 +/- 4.95) dB SPL at 2 h and gradually decreased near the normal level. CONCLUSION Free radicals in the cochlea increase evidently and have a concentration-time rule after acute acoustic trauma. The ESR method can be used to examine the content of free radicals in cochlea for its direct, objective and sensitive characters.
Animals ; Cochlea ; chemistry ; Electron Spin Resonance Spectroscopy ; Free Radicals ; analysis ; Guinea Pigs ; Hearing Loss, Noise-Induced ; physiopathology

PURPOSE: Demonstrate unequivocally the generation of nitric oxide in experimental autoimmune uveoretinitis by electron spin resonance spectroscopy (ESR) using ferrous iron complex of N-methyl-D-glucamine dithiocarbamate, (MGD)2-Fe2+, as a spin trap. METHODS: Experimental autoimmune uveitis was induced in Lewis rats, and at the peak of the intraocular inflammation, the animals received intravitreous injections of the spin trap. The retina and choroid dissected from the enucleated globes were subjected to ESR. Similarly, the retina and choroid obtained at the peak of experimental autoimmune uveo-retinitis (EAU) were placed in a vial containing luminal, and chemiluminescence was counted on a Packard liquid scintillation analyzer. RESULTS: The ESR three-line spectrum (g=2.04; a(N)=12.5 G) obtained was characteristic of the adduct [(MGD)2-Fe2+-NO]. The majority of this signal was eliminated by the inducible nitric oxide synthase (iNOS) specific inhibitor aminoguanidine injected inflamed retina was detected when compared with that of the non inflamed controls. The chemiluminescent activity was further increased two-fold by the addition of bicarbonate to the inflamed retina; the phenomenon is attributable only to the presence of a high steady-state concentration of peroxynitrite. CONCLUSIONS: The study shows an unequivocal presence of nitric oxide in EAU retina and choroid and the generation of peroxynitrite. High levels of these reactive nitrogen species generated in the inflamed retina and choroids are certain to cause irreversible tissue damage, especially at the susceptible sites such as photoreceptors.
Uveitis/immunology/*metabolism ; Thiocarbamates ; Spin Trapping ; Spin Labels ; Sorbitol/analogs & derivatives ; Retina/metabolism ; Reactive Nitrogen Species/*metabolism ; Rats, Inbred Lew ; Rats ; Peptide Fragments/immunology ; Humans ; Electron Spin Resonance Spectroscopy ; Choroid/metabolism ; Autoimmune Diseases/immunology/*metabolism ; Arrestin/immunology ; Animals

A set of L-band electron spin resonance imaging (ESRI) equipment suitable for biological species was developed and an ESRI experiment model for viable skin samples was established. The mechanic process of nitroxide free radical TEMPO (2,2, 6, 6-tetramethyl-1-piperidinyloxy) penetrating through skin sample and the spin density distribution of TEMPO after it interacted with skin sample were detected by the developed ESRI method. Skin samples were extracted from mice back. The experimental samples were prepared by cutting the skin pieces into square shape of 2 x 2 cm2 and then the samples were divided into three groups by treating them with three different methods: Method A, simple treatment by simply cutting the hair; method B, 8% Na2S depilation treatment for 10 min; method C, 8% Na2S depilation and then 5% pancreatic digestion treatment for 2 hours. The liposoluble solvent DMSO (dimethyl sulfoxide) and distilled water were used as two kinds of solvent for the TEMPO liquor. The results indicated that the skin-penetration properties of TEMPO were significantly different among samples treated with different methods and the surface cornifin of skin offered remarkable resistance to TEMPO. The TEMPO liquor of water could hardly penetrate through skins, whereas about 20%-30% of the original TEMPO compounds that solved in liposoluble solvent DMSO could penetrate through the skin sample treated with method C after 16 hours of interaction. Furthermore, the penetration rate of TEMPO through the skin tissue was a strong time dependent process. The preliminary application results suggested that ESRI technique could provide an effective and applicable method for dynamically researching skin-penetration properties of some special kinds of materials such as paramagnetic compounds.
Animals ; Cyclic N-Oxides ; pharmacokinetics ; Dimethyl Sulfoxide ; chemistry ; Electron Spin Resonance Spectroscopy ; methods ; Free Radical Scavengers ; pharmacokinetics ; Mice ; Piperidines ; pharmacokinetics ; Skin Absorption ; physiology ; Skin Physiological Phenomena ; drug effects ; Spin Labels