Estimativa da idade aplicada a investigações arqueológicas utilizando espectroscopia RPE ­ uma revisão / Dental age estimation applied to archaeological investigations using spectroscopy ESR ­ a review

A estimativa da idade utilizando dentes humanos é realizada por várias ciências. Enquanto na odontologia e antropologia forense o significado desta estimativa está associado à idade cronológica em indivíduos vivos ou mortos, na arqueologia o significado é outro, e reflete o tempo decorrido desde a formação do dente até a sua descoberta no sítio arqueológico, a chamada datação arqueológica. Diante do potencial uso da datação para identificação de corpos antigos (fossilizados) na área forense, o objetivo deste trabalho é abordar a estimativa da idade de dentes sob a perspectiva da arqueologia, por meio do principal método de datação utilizado: o da espectroscopia por ressonância paramagnética eletrônica (RPE). Com o intuito de verificar as principais aplicações deste método na datação de dentes humanos, foi realizada uma revisão da literatura. Os 18 artigos selecionados mostram que a espectroscopia RPE encontra-se consolidada como método de datação para dentes humanos e tem sido aplicada com sucesso nas últimas décadas, na solução de problemas de diversas pesquisas arqueológicas, ajudando a elucidar questionamentos acerca da dinâmica de ocupação, interações interespecíficas e extinção de várias espécies humanas que habitaram a Terra nas últimas centenas de milhares de anos

Age estimation using human teeth is performed by several fields of knowledge. While in forensic dentistry and anthropology the meaning of this estimate is associated with chronological age in living or dead individuals, in archaeology, the meaning is different and reflects the time elapsed from the formation of the tooth until its discovery at the archaeological site, the so-called archaeological dating. Faced with the potential use of archaeological dating to identify ancient (fossilized) bodies in the forensic area, the aim of this work is to approach the age estimation of teeth from the perspective of archaeology, through the main dating method used: Electron spin resonance (ESR) spectroscopy. In order to verify the main applications of this method for the dating of human teeth, a literature review was carried out. 18 articles were selected and show that ESR spectroscopy is consolidated as a dating method for human teeth and it has been applied, successfully over the last few decades, in the solution of problems of several archaeological researches, helping to clarify questions about the dynamics of occupation, interspecific interactions and extinction of several human species that have inhabited the Earth in the last few hundred thousand years

Stability of carbonate hydroxyapatite dosimeter material / 军事医学

Objective To develop a promising type of radiation dosimeter based on doped hydroxyapatite,and to study the stability of dosimetric characteristics indepth.Methods The samples prepared by stereotyping techniques were stored under different temperatures,humidity and illumination conditions after 60Co γ-ray irradiation.Electron spin resonance (ESR) technique was used to quantitatively measure the radiation-induced free radical signal.Results The signal change was less than 3% when the dosimeter was preserved at 4℃ or room temperature within 3 months in the experiment.At 40℃,the signal changed by about 13%,but at room temperature with the humidity less than 36%,the signal changed less than 2%.The change rose to about 8% when humidity was 76%.However,no significant decay of signal strength occurred at relatively high temperatures and under high humidity conditions.When the samples were stored under average illumination of 1600 lux or in a light-resistant container,the signal changes were less than 3.8% or 3.4% respectively.Long-term stability inspection at room temperature suggested a signal change within 4.8%.Conclusion The dosimetric properties of the material don't change significantly below room temperature in a natural environment and exhibit good stability over long-term storage.The free radical signal is not influenced drastically by relatively strong light exposure.However,a high temperature or a highly humid environment may have some effect on the measurement process,which should be taken into consideration in further applications.

Accuracy of dose planning for prostate radiotherapy in the presence of metallic implants evaluated by electron spin resonance dosimetry

Radiotherapy is one of the main approaches to cure prostate cancer, and its success depends on the accuracy of dose planning. A complicating factor is the presence of a metallic prosthesis in the femur and pelvis, which is becoming more common in elderly populations. The goal of this work was to perform dose measurements to check the accuracy of radiotherapy treatment planning under these complicated conditions. To accomplish this, a scale phantom of an adult pelvic region was used with alanine dosimeters inserted in the prostate region. This phantom was irradiated according to the planned treatment under the following three conditions: with two metallic prostheses in the region of the femur head, with only one prosthesis, and without any prostheses. The combined relative standard uncertainty of dose measurement by electron spin resonance (ESR)/alanine was 5.05%, whereas the combined relative standard uncertainty of the applied dose was 3.35%, resulting in a combined relative standard uncertainty of the whole process of 6.06%. The ESR dosimetry indicated that there was no difference (P>0.05, ANOVA) in dosage between the planned dose and treatments. The results are in the range of the planned dose, within the combined relative uncertainty, demonstrating that the treatment-planning system compensates for the effects caused by the presence of femur and hip metal prostheses.

Effects of Baoyuan Anticancer Oral Solution on Scavenging of O-2 and DPPH Free Radi-cals / 医药导报

Objective To investigate the scavenging effect of Baoyuan anticancer oral solution on superoxide anion (O-2 ) and 1,1-diphenyl-2-picrylhydrazyl hydrate(DPPH) free radicals. Methods O-2 and DPPH were examined with the ESR (electron spin resonance) spin trapping method. Results The scavenging effect of Baoyuan anticancer oral solution diluted to 50 fold, on O-2 and DPPH free radicals was 81. 32% and 98. 47% , respectively. Conclusion Baoyuan anticancer oral solu-tion has a dose-related effect on free radical elimination.

Relationship between Candidas and melanin / 医学研究生学报

Objective Candidas rank as the second factor of deep fungal infection .This study aimed to investigate the rela-tionship between Candidas and melanin by screening clinically isolated melanin -producing Candidas . Methods We incubated 360 strains of clinically isolated Candidas with caffeic acid , DOPA agar , and minimal medium at a temperature of 35℃, with Cryptococcus neoformans as the positive control .We observed the changes in the culture media using transmission electron microscopy (TEM) and electron spin resonance ( ESR) spectroscopy . Results Cryptococcus neoforman produced pigmentation in all the three types of medi -um.At 5 days, a standard strain of Candida albicans SC 5314 turned dark brown in the DOPA agar and minimal medium and , at 10 days, 12 and 15 of the 360 Candida strains turned dark brown in the DOPA agar and minimal medium , respectively, which were not shown to be melanin by TEM and ESR spectroscopy . Conclusion Culture media are not reliable enough for the identification of mel-anin-producing Candidas , and the observations need to be further verified by TEM and ESR spectroscopy .

Molecular imaging of cerebral ischemic penumbra / 国际脑血管病杂志

Molecular imaging develops faster in the field of neuroimaging of ischemic stroke.Many studies have shown that its values in the aspects of cerebral blood flow monitoring during ischemic stroke and brain tissue metabolism.Ischemic penumbra is the basis of reperfusion therapy for acute ischemic stroke.The imaging methods,including magnetic resonance perfusion-weighted imaging/diffusion-weighted imaging mismatch,have been widely used to reveal ischemic penumbra because of their fast and strong availability.However,they can only reveal the blood flow of penumbra tissue.By contrast,molecular imaging technology can describe and measure the in vivo biological processes on the cellular and molecular levels,thus it can more accurately reveal the penumbral tissue.

Partial pressure of oxygen monitoring based on EPR in chemotherapy for breast cancer and its mechanism / 肿瘤

Objective: The level of partial pressure of oxygen (PO2) in tumor microenvironment affects the tumor's sensitivity to chemothropy directly. Oxygen measuring technique from electron paramagnetic resonance (EPR) can offer the necessary technical to monitor the change of the PO2 in tumor microenvironment after chemothrapy uninvasively, real-time and accurately. Methods: EPR was used to measure the PO2 level directly in vivo. Tumor tissue was collected and the activity of mitochondria was assayed through kinetics of enzyme-catalyzed reactions. The laser doppler monitor was used to detect regional blood flow. Results: The data from the test of tissue oximetry demonstrated the initial PO2 in tumor microenvironment gradually increased to peak value at the fourth week, which was significant higher than initial PO2 of tumor. The PO2 was higher in the experimental group after administration of doxorubicin (ADM). Then PO2 was gradually declined. The functions of mitochondrial nicotinamide adenine dinucleotide reduced dehydragenale, cytochrome C oxidase and succinate-cytochrome C reductase in tumor tissue were lower than those of the control group on the 4th day after chemotherapy. Conclusion: EPR oximtry measuring technique can be used to dynamically monitor the PO2 in tumor microenvironment during the chemotherapy and catch the time window of the peak value of PO2 in tumor microenvironment after chemotherapy exactly. The banlance change between oxygen consumption of mitochondria and the RBF may be one of the mechanisms for PO2 change during ADM chemotherapy.

The protective effect of chlorophyllin against oxidative damage and its mechanism / 中华内科杂志

Objective To investigate whether chlorophyllin could protect human umbilical vein endothelial cell (HUVEC) against oxidative damage by inducing the expression of heme oxygenase-1 (HO-1) and to explore the underlying mechanism.Methods The cellular protection of chlorophyllin against oxidative damage was detected by cell-survival assay with flow cytometry.The level of free radicals was detected directly by electron spin resonance spectra.The induced expression of HO-1 was shown by RT-PCR,Western blot,immunofluorescence confocal laser microscopy and enzymatic activity test.Whether the activation of PI3K/Akt pathway was involved was detected by Western blot.Results Chlorophyllin could protect HUVEC against oxidative damage caused by H2O2 via scavenging the excessive free radicals.Chlorophyllin treatment could induce expression of HO-1 in a dose- and time-dependent manner.The activation of PI3K/Akt pathway was required in the induction of HO-1.LY294002,the specific inhibitor of PI3K,could suppress the activation of PI3K/Akt and the induced expression of HO-1 in a dose-dependent manner.Conclusions Chlorophyllin shows cellular protection against oxidative damage by counteracting the excessive free radicals.Up-regulation of HO-1 expression plays a pivotal role in the protection of chlorophyllin,while the activation of PI3K/Akt signaling pathway is required in the induction of HO-1.

Effects of acupuncture on fatigue and oxidative stress in distance runners:A double-blind trial / 全日本鍼灸学会雑誌

[Objective]To investigate whether acupuncture is effective to prevent fatigue and oxidative stress in distance runners.<BR>[Methods]A total of 17 runners were recruited and randomized to receive acupuncture (Press Tack Needle) or placebo treatment. Subjects received treatment from licensed acupuncturists before a 10 km race. The primary outcome measures were oxidative stress, as determined by electron spin resonance (ESR), and fatigue, as assessed using the Visual Analogue Scale (VAS). Secondary outcome measures were GOT, LDH, and CPK.<BR>[Results]Fatigue was significantly increased in both groups after the race. There was no difference in both groups.<BR>Hydroxyl radical scavenging activity tended to increase in both groups after the race.<BR>[Conclusion]The study found no useful acupuncture aspects of oxidative stress and fatigue.

Anti-oxidative and anti-ulcerogenic activity of Ipomoea imperati

Ipomoea imperati (Vahl) Griseb., Convolvulaceae, is used in traditional medicine for the treatment of inflammation, swelling and wounds, as well as to treat pains and stomach problems. This work evaluates the anti-oxidative activity by ESR (Electron Spin Resonance spectroscopy) and the preventive and curative actions of I. imperati in gastric ulcer animal model. Ipomoea imperati (200 mg/kg, p.o.) prevented the formation of gastric lesions in 78 percent (p<0.05) when compared with the negative control tween 80. Lanzoprazole, prevented in 85 percent the gastric lesions formation induced by ethanol (p<0.05). Therefore, the oral administration of I. imperati one hour before the ulcerogenic agent prevented the ulcer formation, conserving the citoprotection characteristics of the gastric mucosa and assuring the integrity of gastric glands and gastric fossets. The healing activity of I. imperati (200 mg/kg, p.o.) evaluated in chronic ulcer experiments induced by the acetic acid, was 72 percent (p<0.05). The positive control, ranitidine, healed 78 percent of the gastric lesions (p<0.05). The histological analysis confirmed the recovery of the mucosal layer and the muscle mucosal layer harmed by the acetic acid. Experiments in vitro with DPPH (2.2-diphenyl-1-picrylhydrazyl) of anti-oxidative activity demonstrated that I. imperati presents an IC50 of 0.73±0.01 mg/mL.

Properties of goat tooth enamel electron spin resonance dosimetry / 中华放射医学与防护杂志

Objectlve To study the properties of goat tooth enamel electron spin resonance (ESR)dosimetry.Methods Tootll enamel samples of goats were achieved by combined mechanical and chemical treatment at the ages of l,2,3,5,and 6 years.respectively and 9 enamel samples of adult molar were obtained.These enamel samples were exposed to 137Cs γ-rays at the cumulative doses of 0,0.5,1.0,2.0,and 5.0 Gy,respectively.ESR spectra Was measured before and after exposure.Results The background signal of goat tooth samples W88 21.5,significantly lower than that of the adult molar samples(39.5).The dusimetric signal intensity of the goat enamel increased with the radiation dose in a linear manner just as that of the human molars.The average radiation sensitivity of the goat tooth samples was(34.3±1.9)/Gy,close to that of the human tooth samples.Conclusions Goat teeth can be used for retrospective radiation dose reconstruction when human teeth are unavailable,in order to previde scientific data for dose reconstruction accurately.

Tooth enamel electron spin resonance dosimetry of people living in the area with lime tobacco custom / 中华放射医学与防护杂志

Objective To study the effect of the custom of long term chewing lime tobacco on human tooth enamel electron spin resonance (ESR) dosimetry. Methods A total of 20 enamel samples from lingual parts of adults teeth collected in Bombay, India were obtained by mechanical method. Some enamel samples from Japanese adults were extracted and 10 mixed samples were prepared. Enamel samples were exposed to different doses of 60Co γ-rays several times, and ESR spectra were measured after exposure. Results ESR background signals of 9 Bombay samples were found 1.5-3.3 times higher than those of Japanese mixed samples. The γ-ray dose responses of dosimetric signal with higher background level were a little lower, and the average sensitivity was (0.42 ± 0.03 )mGy, which was close to that of Japanese mixed samples. Conclusions The average level of background signals of Bombay samples was much higher than that of other non-chewing tobacco area, which was possibly caused by tobacco lime, the main component in chewing tobacco productions, and it would help to explore its special influences on ESR, and improve dose reconstruction in accuracy.

Structural properties of lipid reconstructs and lipid composition of normotensive and hypertensive rat vascular smooth muscle cell membranes

Multiple cell membrane alterations have been reported to be the cause of various forms of hypertension. The present study focuses on the lipid portion of the membranes, characterizing the microviscosity of membranes reconstituted with lipids extracted from the aorta and mesenteric arteries of spontaneously hypertensive (SHR) and normotensive control rat strains (WKY and NWR). Membrane-incorporated phospholipid spin labels were used to monitor the bilayer structure at different depths. The packing of lipids extracted from both aorta and mesenteric arteries of normotensive and hypertensive rats was similar. Lipid extract analysis showed similar phospholipid composition for all membranes. However, cholesterol content was lower in SHR arteries than in normotensive animal arteries. These findings contrast with the fact that the SHR aorta is hyporeactive while the SHR mesenteric artery is hyperreactive to vasopressor agents when compared to the vessels of normotensive animal strains. Hence, factors other than microviscosity of bulk lipids contribute to the vascular smooth muscle reactivity and hypertension of SHR. The excess cholesterol in the arteries of normotensive animal strains apparently is not dissolved in bulk lipids and is not directly related to vascular reactivity since it is present in both the aorta and mesenteric arteries. The lower cholesterol concentrations in SHR arteries may in fact result from metabolic differences due to the hypertensive state or to genes that co-segregate with those that determine hypertension during the process of strain selection.

Elaboración de dosímetros de alanina y sus posibles aplicaciones en riesgos profesionales / Elaboração de dosímetros de alanina e suas possíveis aplicações em riscos profissionais / Elaboration of alanine dosimeters and their possible applications in professional risks

Desarrollar dosímetros de alanina y alanina/parafina con miras a atender la creciente utilización de la radiación ionizante a nivel tecnológico. Materiales y métodos. Los radicales libres producidos por la radiación ionizante en la alanina se detectan por resonancia magnética electrónica (ESR); la parafina se utiliza como aglutinante. La metodología de preparación incluye: elaboración, irradiación, lectura y análisis de datos para los dos tipos de dosímetros. Los espectros ESR estudiados corresponden a dosímetros de alanina con masas entre 60 y 120 mg e irradiados con dosis de 10 y 20 Gy, y dosímetros de alanina/parafina de 160 mg e irradiados con diferentes dosis en un haz de fotones de 4 MV. Resultados. La intensidad de los espectros (las cinco líneas características) depende de las dosis recibidas por los dosímetros y su relación es lineal. Con alanina pura y una dosis de 10 Gy la mínima cantidad requerida fue 120 mg; la compactación del cilindro lograda no fue suficiente para evitar la fragmentación parcial del dosímetro. La parafina no tiene señal paramagnética; en los dosímetros de alanina/parafina (cilindros de longitud 13 mm y diámetro 3.5 mm, en la relación 80:20, y buena dureza) se estudió la respuesta señal ESR-dosis en un rango entre 20 y 120 Gy. Conclusiones. Los cilindros de alanina/parafina fabricados tienen una dureza apropiada para ser manipulados como dosímetros de radiación ionizante; su reproducibilidad y la efectividad en la acumulación de dosis es buena...

Elaboration of alanine dosimeters and their possible applications in professional risks. Objective. To develop dosimeters of alanine and alanine/paraffin in order to meet the growing use of ionizing radiation at the technological level. Materials and methods. Free radicals produced by ionizing radiation in alanine are detected by electron spin resonance (ESR); paraffin is used as binder. The methodology ofpreparation includes: elaboration, irradiation, data collection and data analysis for the two types of dosimeters. The ESR spectra studied correspond to alanine dosimeters with masses between 60 and 120 mg and irradiated with doses of 10 and 20 Gy, and alanine/paraffin dosimeters with 160 mg and irradiated with different doses in a beam of photons 4 MV. Results. The intensity of the spectra (thecharacteristic five lines) depends on the doses received by the dosimeters and their relationship is linear. With pure alanine and a dose of 10 Gy, the minimum amount required was 120 mg; the achieved cylinder compaction was not sufficient to avoid the partial fragmentation of the dosimeter. Paraffin has no paramagnetic signal; in the alanine/paraffin dosimeters (cylinders of 13 mm in length and 3.5 mm of diameter, with a ratio 80:20, and good hardness) the response signal ESR-dose was studied in a range between 20 and 120 Gy. Conclusions. The cylinders of alanine/paraffin manufactured have an appropriate hardness to be handled as dosimeters of ionizing radiation; their reproducibility and effectiveness in the accumulation of dose is good...

Elaboração de dosímetros de alanina e suas possíveis aplicações em riscos profissionais. Objetivo. Desenvolver dosímetros de alanina e alanina/parafina com a finalidade de satisfazer a crescente utilização de radiações ionizantes ao nível tecnológico. Materiais e métodos. Os radicais livres produzidos pela radiação ionizante na alanina são detectados por ressonância magnética eletrônica (EPR); a parafina é utilizada como aglutinante. O método de preparação inclui: elaboração, irradiação, leitura e analise dos dados para os dois tiposde dosímetros. Os espectros ESR estudados correspondem a dosímetros de alanina com massas entre 60 e 120 mg e irradiados com doses de 10 e 20 Gy, e dosímetros de alanina/parafina de 160 mg e irradiados com diferentes doses de um feixe de fótons de 4 MV. Resultados.A intensidade dos espectros (as cinco linhas características) depende das doses recebidas pelos dosímetros e sua relação é linear. Com lanina pura e uma dose de 10 Gy a mínima quantidade requerida foi de 120 mg; a compactação do cilindro alcançada não foi suficiente para evitar a fragmentação parcial do dosímetro. A parafina não tem sinal paramagnético; nos dosímetros de alanina/parafina (cilindros de 13 mmde comprimento e 3,5 mm de diâmetro, na proporção 80:20 e boa dureza) foi estudada a resposta a sinal ESR-dose em um intervalo entre 20 e 120 Gy. Conclusões. Os cilindros de alanina/parafina fabricados têm uma dureza adequada para ser tratados como dosímetros de radiação ionizante; sua reprodutibilidade e eficiência no acúmulo de dose é bom...

Identification and Characterization of Carbon-Centered Free Radicals Formed from Lipoxygenase-Catalyzed Lipid Peroxidation of Dihomo-γ-linolenic Acid / 分析化学

A combination technique of LC/ESR, LC/MS and spin trapping was used to identify and characterize the carbon-centered free radicals formed from lipoxygenase-catalyzed peroxidation of dihomo-γ-linolenic acid(DGLA). The spin trap, α-[4-pyridyl-1-oxide]-N-tert-butyl nitrone(POBN), could react with short-lived carbon-centered radicals to form relatively stable adducts. Based on the same retention time of POBN radical adduct in LC/UV/ESR and LC/MS, molecular weight of adduct could be confirmed and the structure of adduct could be confirmed by their LC/MS2 fragment pattern. The results showed that free radicals formed in lipoxygenase-catalyzed peroxidation of DGLA, including ~·C_7H_(13)O_2, ~·C_(10)H_(17)O_2 and ~·C_5H_(11), all stemmed from β-scission of DGLA alkoxyl radicals(8-, 11-, 15-LO~·). The results were helpful for further study of biological activities of these radicals in vivo.

Effects of Some Essential Oils on Superoxide Radical Formation in the Reaction Mixture of Riboflavin under UVA Irradiation / 日本補完代替医療学会誌

<i>Objective</i>: The effects of essential oils on the formation of superoxide radicals during UVA (365 nm) irradiation were investigated.<br> <i>Methods</i>: ESR (electron spin resonance) spin-trapping experiments were performed on a reaction mixture containing 15 μM riboflavin, 0.10 M DMPO (5,5-dimethyl-l-pyrroline-<i>N</i>-oxide), 23 mM phosphate buffer (pH 7.4) and 6.3% (v/v) DMSO (dimethyl sulfoxide) (standard reaction mixture) during UVA (365 nm) irradiation.<br> <i>Results</i>: On addition of various concentrations of tea tree oil (<i>or</i> lavender super oil <i>or</i> grapefruit oil <i>or</i> peppermint oil <i>or</i> wintergreen oil) to the standard reaction mixture, the ESR peak height decreased dose-dependently.<br> <i>Conclusion</i>: This result shows that antioxidant activities increase as follows: lavender super oil<grapefruit oil<peppermint oil<tea tree oil<wintergreen oil.<br>

Estimation of solar radiation and its effects on tooth enamel electron spin resonance dosimetry / 中华放射医学与防护杂志

Objective To investigate solar radiation and its effects on human tooth enamel electron spin resonance (ESR) dosimetry. Methods 11 tooth enamel samples were prepared by mechanical method. The intensity of solar iUuminanee was measured with a light meter, the measured illuminance was converted to insolation using a coefficient. Summation of solar radiation was evaluated. Enamel samples were exposed to 60 Co γ rays followed by sunlight on sunny days, and ESR spectra were scanned after different exposure. Results The solar radiation to the samples was (580 ± 16) MJ/m2. Solar exposure also caused dosimetrie signal. The perpendicular component of dosimetrie signal increased linearly with the amount of solar radiation, another signal close to background tended to saturation. Conclusions The average effect of the solar radiation on the signal was be used to recognize the effect of solar radiation on the enamel, and estimate external dose accurately.

Direct Detection of Reactive Nitrogen Species in Experimental Autoimmune Uveitis

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.

Effect of Xuesaitong on lower limb of rabbit ischemia-reperfusion free radical / 中华中医药杂志

Objective: To investigate the protective effect of Xuesaitong(total saponins of sanchi) on lower extremity ischemical reperfusion injury.Methods: To observe PBN-spin bulky adducts signal of lower extremity ischemical reperfusion of rabbit by using electron spin resonance technology and electron spin resonance promoter N-tert-butyl-2-phenylnitrone(PBN).Results: The signal intensity is correlated with time,compared with ischemia for 2 hours,the signal intensity of ischemia for 4 hours increased apparently.Xuesaitong would quench PBN-spin bulky adducts signal significantly.Conclusion: Xuesaitong have protective effect on lower extremity ischemia-reperfusion injury.

Influence of tetramethylpyrazine on oxygen metabolism during the respi ratory burst of human neutrophiis / 中国临床药理学与治疗学

AimTo investigate the influence of tetramethylpyrazine(ligustrazine, Lig) on oxygen consumption and superoxide during the respiratory burst of human neutrophils. MethodsIt was observed by using ESR spin trapping, spin probe oxymetry and luminol-dependent chemiluminesence(CL) . Results Lig had no influence on oxygen consumption during the respiratory burst of neutrophils(P＞0.05), but had remarkable inhibition on CL response generated by neutrophils(P＜0.01), and had scavenging effect on O2 and OH ·generated by neutrophils, which were demonstrated in xanthine/ xanthine oxidase system and Fentons reaction(P＜0.01) . ConclusionLig has no inhibiting effect on oxygen metabolic function of neutrophils,but protects tissue from injury caused by activated neutrophils through scavenging oxygen radicals.