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1.
Cuad. Hosp. Clín ; 62(1): 33-37, jun. 2021.
Article in Spanish | LILACS | ID: biblio-1284253

ABSTRACT

INTRODUCCIÓN: el tiroides exhibe una gran avidez por el yodo radioactivo (I131) que al ser fijado por ésta glándula puede determinarse, desde afuera, aprovechando el hecho de que las radiaciones gamma atraviesan los tejidos blandos del cuello y pueden registrarse (Gammagrafía) a distancias apreciables. Desde 1962 Bolivia cuenta con esta tecnología, sin embargo, no cuenta con trabajos similares desde la declaración de país libre de enfermedades secundarias a la deficiencia de Yodo en 1997. El objetivo fue determinar valores de la captación tiroidea de I131 a las 24 horas en adultos jóvenes eutiroideos, residentes de gran altitud. MÉTODO: se realizó un estudio descriptivo transversal, en 76 sujetos obtenidos por intención y seleccionados mediante una entrevista clínica, examen físico dirigido y un consentimiento informado. El procedimiento fue ejecutado por personal calificado en el INAMEN siguiendo las recomendaciones de la OIEA. RESULTADOS: el valor de la captación tiroidea de I131 en 24 horas fue de 18,23 + 5,79% (rango 7,70 ­ 39,70). DISCUSIÓN: los expertos recomiendan establecer valores de referencia actualizados en cada región. Se han descrito variaciones de los valores normales influenciados por el sexo y edad; esta última, aparentemente por una hipofunción tiroidea inversamente proporcional con la edad. CONCLUSIÓN: el valor referencial encontrado en nuestro estudio es concordante con los establecidos en el extranjero, sin embargo, con una tendencia incrementada. Podría deberse a la secuencia cronológica de los estudios comparados en países que ya habían establecido políticas de yodación más tempranamente.


INTRODUCTION: the thyroid exhibits a great avidity for radioactive iodine (I131) which, when fixed by this gland, can be determined from the outside, taking advantage of the fact that gamma radiation passes through the soft tissues of the neck and can be registered (scintigraphy) at appreciable distances. Since 1962, Bolivia has had this technology, however, it does not have similar studies since the declaration of a country free of diseases secondary to iodine deficiency in 1997. The objective was to determine values of the thyroid uptake of I131 at 24 hours in euthyroid young adults, high altitude residents. METHOD: a descriptive cross-sectional study was carried out in 76 subjects obtained by intention and selected by means of a clinical interview, directed physical examination and informed consent. The procedure was carried out by qualified personnel at INAMEN, following IAEA recommendations. RESULTS: the value of the thyroid uptake of I131 in 24 hours was 18.23 + 5.79% (range 7.70 - 39.70). DISCUSSION: experts recommend establishing up-to-date reference values in each region. Variations in normal values influenced by sex and age have been described; the latter, apparently due to a thyroid hypofunction inversely proportional to age. CONCLUSION: the reference value found in our study is consistent with those established abroad, however, with an increased trend. It could be due to the chronological sequence of comparative studies in countries that had already established iodination policies earlier.


Subject(s)
Humans , Male , Female , Adult , Cross-Sectional Studies , Iodine , Thyroid Gland , Gamma Rays , Informed Consent
2.
An. Facultad Med. (Univ. Repúb. Urug., En línea) ; 8(1): e203, jun. 2021. tab, graf
Article in Spanish | LILACS, BNUY, UY-BNMED | ID: biblio-1248717

ABSTRACT

El vino tinto variedad Vitis vinifera L. cv Tannat en los últimos años ha tomado relevancia por su alta concentración de polifenoles, esto le podría significar un rol protector sobre el genoma disminuyendo la formación de lesiones oxidativas. Los efectos a nivel celular de las radiaciones ionizantes en blancos como el ADN, componentes de cascadas de transducción de señales, resultan en lesiones letales, mutagénicas y recombinogénicas y en retardos en el ciclo celular. Se utilizó como modelo eucariota poblaciones de Saccharomyces cerevisiae en fase exponencial expuestas a radiación gamma (200 Gy) en presencia, o ausencia, de vino Tannat (10 % v/v) o de ácido tánico (60 µg/mL). Se estimaron las probabilidades de sobrevida y frecuencia mutagénica en distintas condiciones. Las muestras celulares expuestas a radiación ionizante presentaron una fracción de sobrevida de 0.21 ± 0.02 mientras que en las muestras irradiadas en presencia de vino Tannat o de ácido tánico la fracción de sobrevida fue de 0.33 ± 0.03 y 0.30 ± 0.03 respectivamente. Se observó en las poblaciones irradiadas un aumento significativo de la probabilidad de mutagénesis. En el caso de los tratamientos combinados se observó que la frecuencia mutagénica fue significativamente menor (gamma Tannat: 33%, gamma ácido tánico: 45% ). Estos resultados preliminares podrían indicar radioprotección moderada por parte de los compuestos estudiados, efecto que podría explicarse por las interacciones redox del ácido tánico y polifenoles contenidos en el vino con los radicales libres formados por las radiaciones ionizantes, además de la activación de vías de reparación genómica.


The red wine variety Vitis vinifera L. cv Tannat in recent years has gained relevance due to its high concentration of polyphenols, this could mean a protective role on the genome, reducing the formation of oxidative lesions. The effects at the cellular level of ionizing radiation on targets such as DNA, components of signal transduction cascades, result in lethal, mutagenic and recombinogenic lesions and delays in the cell cycle. Exponential phase populations of Saccharomyces cerevisiae exposed to gamma radiation (200 Gy) in the presence or absence of Tannat wine (10% v / v) or tannic acid (60 µg / ml) were used as a eukaryotic model. The probabilities of survival and mutagenic frequency in different conditions were estimated. Cellular samples exposed to ionizing radiation presented a survival fraction of 0.21 ± 0.02, while in samples irradiated in the presence of Tannat wine or tannic acid, the survival fraction was 0.33 ± 0.03 and 0.30 ± 0.03 respectively. A significant increase in the probability of mutagenesis was observed in irradiated populations. In the case of the combined treatments, it was observed that the mutagenic frequency was significantly lower (Tannat gamma: 33%, Tannic acid gamma: 45%). These preliminary results could indicate moderate radioprotection by the compounds studied, an effect that could be explained by the redox interactions of tannic acid and polyphenols contained in wine with the free radicals formed by ionizing radiation, in addition to the activation of genomic repair pathways.


A variedade de vinho tinto Vitis vinifera L. cv Tannat nos últimos anos tem ganhado relevância devido à sua alta concentração de polifenóis, o que pode significar um papel protetor do genoma, reduzindo a formação de lesões oxidativas. Os efeitos no nível celular da radiação ionizante em alvos como o DNA, componentes de cascatas de transdução de sinal, resultam em lesões letais, mutagênicas e recombinogênicas e atrasos no ciclo celular. Populações de fase exponencial de Saccharomyces cerevisiae expostas à radiação gama (200 Gy) na presença ou ausência de vinho Tannat (10% v / v) ou ácido tânico (60 µg / ml) foram utilizadas como modelo eucariótico. Foram estimadas as probabilidades de sobrevivência e frequência mutagênica em diferentes condições. As amostras celulares expostas à radiação ionizante apresentaram uma fração de sobrevivência de 0,21 ± 0,02, enquanto nas amostras irradiadas na presença de vinho Tannat ou ácido tânico, a fração de sobrevivência foi de 0,33 ± 0,03 e 0,30 ± 0,03, respectivamente. Um aumento significativo na probabilidade de mutagênese foi observado nas populações irradiadas. No caso dos tratamentos combinados, observou-se que a frequência mutagênica foi significativamente menor (Tannat gama: 33%, ácido tânico gama: 45%). Esses resultados preliminares podem indicar radioproteção moderada pelos compostos estudados, efeito que pode ser explicado pelas interações redox do ácido tânico e polifenóis contidos no vinho com os radicais livres formados pela radiação ionizante, além da ativação de vias de reparo genômico.


Subject(s)
Animals , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/genetics , Tannins/pharmacology , Mutagenesis/drug effects , Polyphenols/pharmacology , Gamma Rays/adverse effects , Radiation-Protective Agents/pharmacology , Survival Rate , Drug Therapy, Combination , Mutation Rate
3.
J. venom. anim. toxins incl. trop. dis ; 27: e20200140, 2021. graf, ilus
Article in English | ID: biblio-1250256

ABSTRACT

Tetanus toxin blocks the release of the inhibitory neurotransmitters in the central nervous system and causes tetanus and its main form of prevention is through vaccination. The vaccine is produced by inactivation of tetanus toxin with formaldehyde, which may cause side effects. An alternative way is the use of ionizing radiation for inactivation of the toxin and also to improve the potential immunogenic response and to reduce the post-vaccination side effects. Therefore, the aim of this study was to characterize the tetanus toxin structure after different doses of ionizing radiation of 60Co. Methods Irradiated and native tetanus toxin was characterized by SDS PAGE in reducing and non-reducing conditions and MALD-TOF. Enzymatic activity was measured by FRET substrate. Also, antigenic properties were assessed by ELISA and Western Blot data. Results Characterization analysis revealed gradual modification on the tetanus toxin structure according to doses increase. Also, fragmentation and possible aggregations of the protein fragments were observed in higher doses. In the analysis of peptide preservation by enzymatic digestion and mass spectrometry, there was a slight modification in the identification up to the dose of 4 kGy. At subsequent doses, peptide identification was minimal. The analysis of the enzymatic activity by fluorescence showed 35 % attenuation in the activity even at higher doses. In the antigenic evaluation, anti-tetanus toxin antibodies were detected against the irradiated toxins at the different doses, with a gradual decrease as the dose increased, but remaining at satisfactory levels. Conclusion Ionizing radiation promoted structural changes in the tetanus toxin such as fragmentation and/or aggregation and attenuation of enzymatic activity as the dose increased, but antigenic recognition of the toxin remained at good levels indicating its possible use as an immunogen. However, studies of enzymatic activity of tetanus toxin irradiated with doses above 8 kGy should be further analyzed.(AU)


Subject(s)
Radiation, Ionizing , Tetanus , Enzyme-Linked Immunosorbent Assay , Gamma Rays , Tetanus Toxin , Cobalt
4.
Rev. cuba. invest. bioméd ; 40(supl.1): e1176, 2021. tab, graf
Article in English | LILACS, CUMED | ID: biblio-1289469

ABSTRACT

Nowadays, there is a growing interest in biodegradable polymers-based materials due to their diverse application in the biomedical field. Most studied systems involve biocompatible micro and nanodevices, such as liposomes, dendrimer, micelles or polymeric nanogels. The use of Radiation Technology, specifically gamma radiation, to produce micro and nanogels raises the possibility to obtain higher purity products, an important feature for biomedical and pharmaceutical applications. The radio-induced synthesis, characterization, cytotoxicity evaluation, and immunological response of nanogels are described in this study. Nanogel synthesis was performed in the absence of oxygen using aqueous polyvinylpyrrolidone solutions. Crosslinking reactions were carried out at 25 °C in a gamma irradiation chamber with a 60Co source. Nanogels properties were analysed by Scanning Electron Microscopy, Attenuated Total Reflection-Fourier Transform Spectroscopy, Dynamic Light Scattering, and Viscosimetry. The cytotoxicity and immunological response were evaluated by MTT test and analysis of the neutrophil respiratory burst. The results showed that nanogels formation strongly depends on the total absorbed dose. The nanogels have an elliptical shape and their chemical structure is similar to the initial polymer. The nanogels are biocompatible and promote a low-intensity neutrophil activation, similar to the well-characterized biomaterial TiO2, suggesting their potential biomedical uses(AU)


En la actualidad existe un interés creciente en los materiales biodegradables basados en polímeros, debido a sus diversas aplicaciones en la esfera de la biomedicina. En la mayoría de los sistemas estudiados participan micro- y nanodispositivos biocompatibles, tales como liposomas, dendrímeros, micelas o nanogeles poliméricos. El uso de la tecnología de radiaciones, en particular de radiaciones gamma, para producir micro- y nanogeles, eleva la posibilidad de obtener productos de mayor pureza, un rasgo importante con vistas a su aplicación biomédica y farmacéutica. El estudio describe la síntesis radioinducida, caracterización, evaluación de la citotoxicidad y respuesta inmunológica de los nanogeles. La síntesis de los nanogeles se realizó en ausencia de oxígeno, usando soluciones acuosas de polivinilpirrolidona. Las reacciones de entrecruzamiento se realizaron a 25 ºC en cámara de irradiación gamma con una fuente de 60Co. Las propiedades de los nanogeles se analizaron mediante microscopía electrónica de barrido, espectroscopia por transformada de Fourier total atenuada, dispersión dinámica de luz y viscosimetría. La citotoxicidad y la respuesta inmunológica se evaluaron mediante prueba MTT y análisis del estallido respiratorio de neutrófilos. Los resultados muestran que la formación de nanogeles depende en gran medida de la dosis total absorbida. Los nanogeles tienen forma elíptica y su estructura química es similar a la del polímero inicial. Los nanogeles son biocompatibles y promueven una activación de neutrófilos de baja intensidad similar al bien caracterizado material TiO2, lo que sugiere usos biomédicos potenciales(AU)


Subject(s)
Humans , Gamma Rays/therapeutic use , Nanogels/standards , Cytotoxicity Tests, Immunologic
5.
Electron. j. biotechnol ; 41: 81-87, sept. 2019. tab, graf, ilus
Article in English | LILACS | ID: biblio-1087242

ABSTRACT

Background: The search for innovative anti-tubercular agents has received increasing attention in tuberculosis chemotherapy because Mycobacterium tuberculosis infection has steadily increased over the years. This underlines the necessity for new methods of preparation for polymer-drug adducts to treat this important infectious disease. The use of poly(ethylene glycol)(PEG) is an alternative producing anti-tubercular derivatives. However, it is not yet known whether PEGylated isonicotinylhydrazide conjugates obtained by direct links with PEG are useful for therapeutic applications. Results: Here, we synthesized a PEGylated isoniazid (PEG-g-INH or PEG­INH) by gamma radiation-induced polymerization, for the first time. The new prodrugs were characterized using Raman and UV/Vis spectrometry. The mechanism of PEGylated INH synthesis was proposed. The in vitro evaluation of a PEGylated isonicotinylhydrazide macromolecular prodrug was also carried out. The results indicated that PEG­INH inhibited the bacterial growth above 95% as compared with INH, which showed a lower value (80%) at a concentration of 0.25 µM. Similar trends are observed for 0.1, 1, and 5 µM. Conclusions: In summary, the research suggests that it is possible to covalently attach the PEG onto INH by the proposed method and to obtain a slow-acting isoniazid derivative with little toxicity in vitro and higher antimycobacterial potency than the neat drug.


Subject(s)
Polyethylene Glycols/chemistry , Isoniazid/chemistry , Mycobacterium tuberculosis/drug effects , Antitubercular Agents/chemistry , Polyethylene Glycols/pharmacology , Polymers , Spectrum Analysis, Raman , In Vitro Techniques , Prodrugs , Polymerization , Gamma Rays , Isoniazid/pharmacology , Antitubercular Agents/pharmacology
6.
Journal of Experimental Hematology ; (6): 2030-2034, 2019.
Article in Chinese | WPRIM | ID: wpr-781499

ABSTRACT

Abstract  With the development of transfusion medicine and the mastery of blood transfusion diagnosis and treatment techniques, the application of irradiated blood products in our country is gradually increasing. In recent years, the proportion of blood transfused by γ-rays has been increasing. In some foreign countries, the application rate of blood irradiated by radiotherapy is as high as 95%. At present, it is still in the promotion stage in China. This article summarizes the commonly used methods of blood irradiation, including the choice of irradiation source, the core dose and common irradiation targets, compares the difference of different irradiation methods, and generalizes the common application of blood irradiation. It is proposed that in addition to TA-GVHD application, blood irradiation may have a broad prospects for cancer therapy and microbial killing.


Subject(s)
Blood Transfusion , China , Gamma Rays , Graft vs Host Disease , Humans
7.
Article in English | WPRIM | ID: wpr-758881

ABSTRACT

White blood cells (WBCs) and storage period are the main factors of transfusion reactions. In the present study, cytokine/chemokine concentrations after leukoreduction (LR) and irradiation (IR) in stored canine whole blood were measured. Red blood cell storage lesion caused by IR and LR were also compared. Blood samples from 10 healthy Beagles were divided into four groups (no treatment, LR-, IR-, and LR + IR-treated). Leukocytes were removed by filtration in the LR group and gamma radiation (25 Gy) was applied in the IR group. Immunologic factors (WBCs, interleukin-6 [IL-6], C-X-C motif chemokine ligand 8 [CXCL-8], and tumor necrosis factor-alpha) and storage lesion factors (blood pH, potassium, and hemolysis) were evaluated on storage days 0, 7, 14, 21, and 28. Compared to the treated groups, IL-6 and CXCL-8 concentrations during storage were significantly higher in the control (no treatment) group. LR did not show changes in cytokine/chemokine concentrations, and storage lesion presence was relatively mild. IR significantly increased CXCL-8 after 14 days of storage, but IR of leukoreduced blood did not increase CXCL-8 during 28 days of storage. Storage lesions such as hemolysis, increased potassium, and low pH were observed 7 days after IR and storage of blood, regardless of LR. IR of leukoreduced blood is beneficial to avoid immune reactions; however, storage lesions should be considered upon storage.


Subject(s)
Blood Preservation , Down-Regulation , Erythrocytes , Filtration , Gamma Rays , Hemolysis , Hydrogen-Ion Concentration , Immunologic Factors , Interleukin-6 , Leukocyte Reduction Procedures , Leukocytes , Necrosis , Potassium , Transfusion Reaction
8.
Article in Chinese | WPRIM | ID: wpr-771925

ABSTRACT

OBJECTIVE@#To improve and establish the mouse model with aplastic anemia (AA) mediated by Cs γ-ray irradiation combined with cyclophosphamide (CTX) and chloramphenicol (CHL) injection,so as to provide a stable model for studying the pathogenesis and treatment of AA .@*METHODS@#The BALB/c mice were exposed to Cs γ-ray of 3-5 Gy(91 cGy/min) and were intraperitoneally injected with CTX of 25 mg/(kg.d) and CHL of 62.5 mg/(kg.d) at D 4,5 and 6 after irradiation; the WBC, platelet and reticulocyte counts in peripheral blood as well as the mucleated cell count in bone marrow and bone marrow smears were detected .@*RESULTS@#The 3-lineage cells in peripheral blood of BALB/c mouse model with acquired AA were rapidly reduced, especially WBC, platelet and reticulocyte counts were lowest at D 14,the 3-lineage cells in peripheral blood were still severely reduced at D 28; the nucleated cell count in bone marrow significantly dcreased,the bone marrow hyperplasia was reduced or severely reduced; the pathological sections of bone marrow showed the severe reduction of hematopoietic cells and the increased of non-hematopoietic cells such as fat cells.@*CONCLUSION@#The mouse model with acquired AA has been established by Cs γ-ray irradiation combined with CTX and CHL injection. All detection indicators of this model reach to diagnostic criteria for acquired AA,therefore this mouse model may be used as the model for study of pathogenesis and treatment of acquired AA.


Subject(s)
Anemia, Aplastic , Animals , Chloramphenicol , Cyclophosphamide , Gamma Rays , Mice , Mice, Inbred BALB C
9.
Electron. j. biotechnol ; 35: 57-62, sept. 2018. tab, graf
Article in English | LILACS | ID: biblio-1047773

ABSTRACT

Background: Rubus is an economically important fruit crop across the globe. Recently, several Rubus mutant genotypes with improved agronomic traits have been developed using gamma ray irradiation. This study investigated genetic diversity and variations in Rubus mutant genotypes using single nucleotide polymorphism (SNP) markers generated from genotyping-by-sequencing (GBS) analysis. A GBS library of 14 Rubus genotypes, consisting of seven boysenberry mutant lines, four blackberry mutant lines, and three original varieties, were sequenced on the Illumina Hiseq2000 platform. A set of SNPs were analyzed by Kompetitive Allele Specific PCR (KASP) assay in order to discriminate the Rubus genotypes. Results: A total of 50,831,040 (86.4%) reads of clean data were generated, and the trimmed length ranged from 116,380,840 to 509,806,521 bp, with an average of 228,087,333 bp per line. A total of 19,634 high-quality SNPs were detected, which contained 11,328 homozygous SNPs and 8306 heterozygous SNPs. A set of 1504 SNPs was used to perform a phylogenetic analysis, which showed that there were clear differences among the Rubus genotypes based on their origin. A total of 25 SNPs were used for the KASP assays, of which six KASP primer sets were successfully distinguished among the Rubus genotypes. Conclusions: This study demonstrated that the SNP and KASP method is an economically efficient tool for mutant screening in Rubus breeding programs.


Subject(s)
Polymorphism, Single Nucleotide/genetics , Rubus/genetics , Phylogeny , Breeding , Genetic Markers , Crops, Agricultural , Alleles , High-Throughput Nucleotide Sequencing , Gamma Rays , Genotype , Mutation
10.
An. acad. bras. ciênc ; 90(1): 425-438, Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-886888

ABSTRACT

ABSTRACT This study evaluated the quality of heartwood and sapwood from mature trees of three species of Eucalyptus, by means of the qualification of their proportion, determination of basic and apparent density using non-destructive attenuation of gamma radiation technique and calculation of the density uniformity index. Six trees of each species (Eucalyptus grandis - 18 years old, Eucalyptus tereticornis - 35 years old and Corymbia citriodora - 28 years old) were used in the experimental program. The heartwood and sapwood were delimited by macroscopic analysis and the calculation of areas and percentage of heartwood and sapwood were performed using digital image. The uniformity index was calculated following methodology which numerically quantifies the dispersion of punctual density values of the wood around the mean density along the radius. The percentage of the heartwood was higher than the sapwood in all species studied. The density results showed no statistical difference between heartwood and sapwood. Differently from the density results, in all species studied there was statistical differences between uniformity indexes for heartwood and sapwood regions, making justifiable the inclusion of the density uniformity index as a quality parameter for Eucalyptus wood.


Subject(s)
Wood/anatomy & histology , Eucalyptus/anatomy & histology , Gamma Rays , Quality Control , Specific Gravity , Wood/analysis , Brazil
11.
Braz. j. med. biol. res ; 51(9): e7404, 2018. graf
Article in English | LILACS | ID: biblio-951760

ABSTRACT

DNA repair pathways, cell cycle checkpoints, and redox protection systems are essential factors for securing genomic stability. The aim of the present study was to analyze the effect of Ilex paraguariensis (Ip) infusion and one of its polyphenolic components rutin on cellular and molecular damage induced by ionizing radiation. Ip is a beverage drank by most inhabitants of Argentina, Paraguay, Southern Brazil, and Uruguay. The yeast Saccharomyces cerevisiae (SC7Klys 2-3) was used as the eukaryotic model. Exponentially growing cells were exposed to gamma rays (γ) in the presence or absence of Ip or rutin. The concentrations used simulated those found in the habitual infusion. Surviving fractions, mutation frequency, and DNA double-strand breaks (DSB) were determined after treatments. A significant increase in surviving fractions after gamma irradiation was observed following combined exposure to γ+R, or γ+Ip. Upon these concomitant treatments, mutation and DSB frequency decreased significantly. In the mutant strain deficient in MEC1, a significant increase in γ sensitivity and a low effect of rutin on γ-induced chromosomal fragmentation was observed. Results were interpreted in the framework of a model of interaction between radiation-induced free radicals, DNA repair pathways, and checkpoint controls, where the DNA damage that induced activation of MEC1 nodal point of the network could be modulated by Ip components including rutin. Furthermore, ionizing radiation-induced redox cascades can be interrupted by rutin potential and other protectors contained in Ip.


Subject(s)
Rutin/pharmacology , Saccharomyces cerevisiae/drug effects , Saccharomyces cerevisiae/radiation effects , Plant Extracts/pharmacology , Antimutagenic Agents/pharmacology , Ilex paraguariensis/chemistry , Radiation Protection/methods , Mass Spectrometry , DNA, Fungal/radiation effects , Cell Survival/drug effects , Cell Survival/radiation effects , Cells, Cultured , Reproducibility of Results , Chromatography, Liquid , Mutagenesis , DNA Repair , Dose-Response Relationship, Radiation , DNA Breaks, Double-Stranded , Mutation Rate , Gamma Rays
12.
Braz. oral res. (Online) ; 32: e004, 2018. tab, graf
Article in English | LILACS | ID: biblio-889501

ABSTRACT

Abstract Radiation combined injury, a life-threatening condition, has higher mortality than simple radiation injury. The aim of the present study was to analyze the efficiency of Aloe vera and silver nanoparticles in improving the healing of ulcerated oral mucosa after irradiation. Thirty male Albino mice were divided into five groups: control, radiation, Aloe vera (AV), silver nanoparticles (NS), and AV+NS. The mice were exposed to whole body 6Gy gamma-radiation. After one hour, 20% acetic acid was injected into the submucosal layer of the lower lip for ulcer induction. The animals received topical treatment with the assigned substances for 5 days. Lip specimens were subjected to hematoxylin and eosin and anti alpha-smooth muscle actin immunohistochemical staining. Results demonstrated occurance of ulcer three days post irradiation in all groups except in the AV+NS group where only epithelial detachment was developed. After seven days, data revealed persistent ulcer in radiation group, and almost normal epithelium in the AV+NS group. A significant reduction of epithelial thickness was detected in all groups at the third day as compared to control. At the seventh day, only the AV+NS group restored the epithelial thickness. Area percent of alpha-smooth muscle actin expression was significantly decreased in radiation group at the third day followed by significant increase at the seventh day. However, all treatment groups showed significant increase in alpha-smooth muscle actin at the third day, which decreased to normal level at the seventh day. Our study demonstrated the efficiency of Aloe vera and silver nanoparticles in enhancing ulcer healing after irradiation.


Subject(s)
Animals , Male , Mice , Aloe/chemistry , Gamma Rays/adverse effects , Metal Nanoparticles/therapeutic use , Oral Ulcer/drug therapy , Oral Ulcer/etiology , Radiation Injuries, Experimental/drug therapy , Silver/therapeutic use , Acetic Acid , Actins/analysis , Administration, Topical , Epithelial Cells/drug effects , Epithelial Cells/radiation effects , Fibroblasts/drug effects , Immunohistochemistry , Microscopy, Electron, Transmission , Oral Ulcer/pathology , Radiation Injuries, Experimental/pathology , Reference Values , Reproducibility of Results , Time Factors , Treatment Outcome , Wound Healing/drug effects
13.
Article in English | WPRIM | ID: wpr-690633

ABSTRACT

There is still a need for better protection against or mitigation of the effects of ionizing radiation following conventional radiotherapy or accidental exposure. The objective of our current study was to investigate the possible roles of matrix metalloproteinase inhibitor, ilomastat, in the protection of mice from total body radiation (TBI), and the underlying protective mechanisms. Ilomastat treatment increased the survival of mice after TBI. Ilomastat pretreatment promoted recovery of hematological and immunological cells in mice after 6 Gy γ-ray TBI. Our findings suggest the potential of ilomastat to protect against or mitigate the effects of radiation.


Subject(s)
Acute Radiation Syndrome , Blood , Allergy and Immunology , Animals , Blood Cells , Radiation Effects , Dose-Response Relationship, Drug , Gamma Rays , Hydroxamic Acids , Therapeutic Uses , Indoles , Therapeutic Uses , Matrix Metalloproteinase Inhibitors , Therapeutic Uses , Mice , Radiation Injuries, Experimental , Blood , Allergy and Immunology , Radiation-Protective Agents , Therapeutic Uses , Spleen , Allergy and Immunology , Radiation Effects , Survival Analysis , Whole-Body Irradiation
14.
Biomedical Engineering Letters ; (4): 383-392, 2018.
Article in English | WPRIM | ID: wpr-717985

ABSTRACT

For prompt gamma ray imaging for biomedical applications and environmental radiation monitoring, we propose herein a multiple-scattering Compton camera (MSCC). MSCC consists of three or more semiconductor layers with good energy resolution, and has potential for simultaneous detection and differentiation of multiple radio-isotopes based on the measured energies, as well as three-dimensional (3D) imaging of the radio-isotope distribution. In this study, we developed an analytic simulator and a 3D image generator for a MSCC, including the physical models of the radiation source emission and detection processes that can be utilized for geometry and performance prediction prior to the construction of a real system. The analytic simulator for a MSCC records coincidence detections of successive interactions in multiple detector layers. In the successive interaction processes, the emission direction of the incident gamma ray, the scattering angle, and the changed traveling path after the Compton scattering interaction in each detector, were determined by a conical surface uniform random number generator (RNG), and by a Klein-Nishina RNG. The 3D image generator has two functions: the recovery of the initial source energy spectrum and the 3D spatial distribution of the source. We evaluated the analytic simulator and image generator with two different energetic point radiation sources (Cs-137 and Co-60) and with an MSCC comprising three detector layers. The recovered initial energies of the incident radiations were well differentiated from the generated MSCC events. Correspondingly, we could obtain a multi-tracer image that combined the two differentiated images. The developed analytic simulator in this study emulated the randomness of the detection process of a multiple-scattering Compton camera, including the inherent degradation factors of the detectors, such as the limited spatial and energy resolutions. The Doppler-broadening effect owing to the momentum distribution of electrons in Compton scattering was not considered in the detection process because most interested isotopes for biomedical and environmental applications have high energies that are less sensitive to Doppler broadening. The analytic simulator and image generator for MSCC can be utilized to determine the optimal geometrical parameters, such as the distances between detectors and detector size, thus affecting the imaging performance of the Compton camera prior to the development of a real system.


Subject(s)
Clothing , Gamma Rays , Isotopes , Radiation Monitoring , Semiconductors
15.
Arq. bras. med. vet. zootec. (Online) ; 69(6): 1683-1692, nov.-dez. 2017. tab
Article in English | ID: biblio-911302

ABSTRACT

The quality of products derived from eggs depends on the quality of the raw material source and the industrial production. The contamination by fungi and bacteria can occur after exposure of the product in the retail market. The objective of this study was to evaluate the microbiological quality of 60 samples of derivated egg products and evaluate the effects of gamma radiation of cobalt-60, using the dose of 5 and 10 kGy, for decontamination of products collected in the retail market in the São Paulo city. The bacterial count was performed by the most probable number (MPN) and the fungal counts by serial dilution after plating surface. It was observed a decrease in the humidity and water activity (Aw) values of irradiated whole egg powder and white egg powder samples (p<0.05), but there was no significant change in the pH of the same samples irradiated with 5 and 10 kGy (p>0.05). In the powdered yolk the values of pH and Aw presented a significant difference (p<0.05), but no significant difference in the humidity values of 5 and 10 kGy irradiated samples (p>0.05). Effective microbial sterilization of all products occurred at the dose of 10 kGy.(AU)


A qualidade dos produtos derivados de ovos depende da qualidade da matéria-prima e da produção industrial. A contaminação por fungos e bactérias pode ocorrer após a exposição do produto no mercado varejista. O objetivo deste estudo foi avaliar a qualidade microbiológica de 60 amostras de derivados de ovos e avaliar os efeitos da radiação gama de cobalto-60, utilizando-se as doses de 5 e 10 kGy, para descontaminação dos produtos coletados no mercado varejista da cidade de São Paulo. A contagem bacteriana foi realizada pelo número mais provável (MPN), e as contagens fúngicas por diluição seriada em plaqueamento de superfície. Foi observada uma diminuição dos valores da umidade e da atividade de água (Aa) das amostras irradiadas de ovo integral em pó e clara em pó (p<0,05), mas sem alteração significativa do pH nas mesmas amostras irradiadas com 5 e 10 kGy (p>0,05). Em gema em pó, observou-se diferença significativa (p<0,05) nos valores de pH e Aa, mas não houve mudança expressiva nos valores de umidade nas amostras irradiadas com 5 e 10 kGy (p>0,05). A esterilização microbiana eficaz de todos os produtos ocorreu com a dose de 10 kGy.(AU)


Subject(s)
Eggs/microbiology , Eggs/radiation effects , Gamma Rays/therapeutic use , Sterilization/methods , Cobalt/therapeutic use , Fungi/radiation effects
16.
J. appl. oral sci ; 25(6): 657-665, Nov.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-893675

ABSTRACT

Abstract Objective: The purpose of this study was to compare laser with conventional techniques in class V cavity preparation in gamma-irradiated teeth. Methods: Forty extracted human teeth with no carious lesions were used for this study and were divided into two main groups: Group I (n = 20) was not subjected to gamma radiation (control) and Group II (n=20) was subjected to gamma radiation of 60 Gray. Standard class V preparation was performed in buccal and lingual sides of each tooth in both groups. Buccal surfaces were prepared by the Er,Cr:YSGG laser (Waterlase iPlus) 2780 nm, using the gold handpiece with MZ10 Tip in non-contact and the "H" mode, following parameters of cavity preparation - power 6 W, frequency 50 Hz, 90% water and 70% air, then shifting to surface treatment laser parameters - power 4.5 W, frequency 50 Hz, 80% water and 50% air. Lingual surfaces were prepared by the conventional high-speed turbine using round diamond bur. Teeth were then sectioned mesio-distally, resulting in 80 specimens: 40 of which were buccal laser-treated (20 control and 20 gamma-irradiated specimens) and 40 were lingual conventional high-speed bur specimens (20 control and 20 gamma-irradiated specimens). Results: Microleakage analysis revealed higher scores in both gamma groups compared with control groups. Chi-square test revealed no significant difference between both control groups and gamma groups (p=1, 0.819, respectively). A significant difference was revealed between all 4 groups (p=0.00018). Conclusion: Both laser and conventional high-speed turbine bur show good bond strength in control (non-gamma) group, while microleakage is evident in gamma group, indicating that gamma radiation had a dramatic negative effect on the bond strength in both laser and bur-treated teeth.


Subject(s)
Humans , Dental Caries/radiotherapy , Dental Cavity Preparation/methods , Dental Leakage/radiotherapy , Gamma Rays
17.
An. acad. bras. ciênc ; 89(3): 1925-1933, July-Sept. 2017. graf
Article in English | LILACS | ID: biblio-886733

ABSTRACT

ABSTRACT This study aimed to evaluate the radiosensitivity of castor bean seeds after applications of different doses of Cobalt60 gamma radiation. Seeds were pre-soaked for 24 hours in distilled water and then irradiated with 50, 100, 150, and 200 Gy, except the control. Sowing was performed in trays, which contained soil as substrate and were maintained in a greenhouse. The electrical conductivity, emergence, emergence speed index, growth parameters and activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, and catalase) were evaluated in the leaves and roots of castor bean seedlings. Gamma radiation did not affect the electrical conductivity of the seeds; however, at a dose of 200 Gy, the emergence and emergence speed index of the seedlings was negatively affected. An analysis of the morphophysiological parameters revealed a reduction in seedling size as the radiation dose increased. There was a significant increase in superoxide dismutase and ascorbate peroxidase activities at higher radiation doses in the leaves, but not in roots. Thus, the analysis of all the variables suggests a response pattern as to the morphophysiological and biochemical changes of castor bean seedlings due to the increase of gamma radiation, which may serve as a tool for generating greater genetic variability.


Subject(s)
Ricinus/radiation effects , Seeds/radiation effects , Cobalt Radioisotopes , Germination/radiation effects , Gamma Rays , Ricinus/growth & development , Seeds/growth & development , Dose-Response Relationship, Radiation
18.
Hig. aliment ; 31(264/265): 115-121, 27/02/2017.
Article in Portuguese | LILACS | ID: biblio-833118

ABSTRACT

O principal objetivo deste trabalho foi avaliar os efeitos do processo de exposição à radiação gama (césio- 137) na estabilidade físico-química de anéis de lula, Dorytheutis plei, congelados. Foram investigadas 30 amostras, separadas em três grupos, de acordo com a dose de radiação absorvida: 0 kGy (controle), 1,5 kGy e 3,0 kGy. Análises físico-químicas, de Base Voláteis Totais e pH, relevantes na determinação da qualidade do pescado, foram realizadas durante o período de seis semanas. Durante a estocagem, observou-se uma relativa estabilidade físico-química nas amostras estudadas, caracterizando um produto viável para a comercialização. Dentre as doses investigadas, 1,5 kGy mostrou-se a mais apropriada para tratamento do produto. Não houve alteração significativa da composição centesimal das amostras.


Subject(s)
Humans , Animals , Decapodiformes , Food Irradiation/methods , Food Preservation/methods , Frozen Foods , Gamma Rays , Food Composition , Food Samples , Chemical Phenomena
19.
Article in English | WPRIM | ID: wpr-226733

ABSTRACT

PURPOSE: The aim of the present study was to identify the radiation hazards to vascular surgeons and scrub nurses working in mobile fluoroscopy equipped hybrid vascular operation rooms; additionally, to estimate cumulative cancer risk due to certain exposure dosages. METHODS: The study was conducted prospectively in 71 patients (53 men and 18 women) who had undergone vascular intervention at our hybrid vascular theater for 6 months. OEC 9900 fluoroscopy was used as mobile C-arm. Exposure dose (ED) was measured by attaching optically stimulated luminescence at in and outside of the radiation protectors. To measure X-ray scatter with the anthropomorphic phantom model, the dose was measured at 3 distances (20, 50, 100 cm) and 3 angles (horizontal, upward 45°, downward 45°) using a personal gamma radiation dosimeter, Ecotest CARD DKG-21, for 1, 3, 5, 10 minutes. RESULTS: Lifetime attributable risk of cancer was estimated using the approach of the Biological Effects of Ionizing Radiation report VII. The 6-month ED of vascular surgeons and scrub nurses were 3.85, 1.31 mSv, respectively. The attenuation rate of lead apron, neck protector and goggle were 74.6%, 60.6%, and 70.1%, respectively. All cancer incidences among surgeons and scrub nurses correspond to 2,355 and 795 per 100,000 persons. The 10-minute dose at 100-cm distance was 0.004 mSv at horizontal, 0.009 mSv at downward 45°, 0.003 mSv at upward 45°. CONCLUSION: Although yearly radiation hazards for vascular surgeons and scrub nurses are still within safety guidelines, protection principles can never be too stringent when aiming to minimize the cumulative harmful effects.


Subject(s)
Fluoroscopy , Gamma Rays , Humans , Incidence , Luminescence , Male , Neck , Prospective Studies , Radiation, Ionizing , Surgeons
20.
International Journal of Radiation Research. 2017; 15 (1): 107-111
in English | IMEMR | ID: emr-187502

ABSTRACT

4-Methylimidazole [4-MEI] is a simple nitrogen-containing heterocyclic compound, and recently classified as group 2B by International Agency for Research on Cancer [IARC]. Caramel coloring is widely applied food coloring in many food products including coffee, carbonated beverages, beer and wine. In present study, y-irradiation was applied to Caramel Color III to reduce the level of 4-MEI without color changes. Caramel coloring III was y-irradiated with 1, 3, 5, 10, 30, 50 and 100 kGy. Non-irradiated caramel coloring was served as a control. The level of 4-MEI and color were analyzed on all caramel coloring. The concentration of 4-MEI in the non-irradiated caramel coloring was 714.9 mg/kg. The level of 4-MEI in caramel coloring was significantly reduced from 3 kGy y-irradiated caramel coloring [p<0.05]. After 100 kGy irradiation, the amount of 4-MEI in caramel color was at 658 mg/kg, which equates 7.9% reduction from non-irradiated sample. No color change was observed on irradiated and non-irradiated caramel coloring [p>0.05]. Therefore, y-irradiation could be used as an alternative processing method to improve the quality of caramel coloring by reducing 4-MEI content without its color change


Subject(s)
Food Coloring Agents/radiation effects , Carbohydrates/radiation effects , Gamma Rays
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