Clinical usefulness of facial soft tissues thickness measurement using 3D computed tomographic images

International Nuclear Information System (INIS)

Jeong, Ho Gul; Kim, Kee Deog; Hu, Kyung Seok; Lee, Jae Bum; Park, Hyok; Han, Seung Ho; Choi, Seong Ho; Kim, Chong Kwan; Park, Chang Seo

2006-01-01

To evaluate clinical usefulness of facial soft tissue thickness measurement using 3D computed tomographic images. One cadaver that had sound facial soft tissues was chosen for the study. The cadaver was scanned with a Helical CT under following scanning protocols about slice thickness and table speed: 3 mm and 3 mm/sec, 5 mm and 5 mm/sec, 7 mm and 7 mm/sec. The acquired data were reconstructed 1.5, 2.5, 3.5 mm reconstruction interval respectively and the images were transferred to a personal computer. Using a program developed to measure facial soft tissue thickness in 3D image, the facial soft tissue thickness was measured. After the ten-time repeation of the measurement for ten times, repeated measure analysis of variance (ANOVA) was adopted to compare and analyze the measurements using the three scanning protocols. Comparison according to the areas was analysed by Mann-Whitney test. There were no statistically significant intraobserver differences in the measurements of the facial soft tissue thickness using the three scanning protocols (p>0.05). There were no statistically significant differences between measurements in the 3 mm slice thickness and those in the 5 mm, 7 mm slice thickness (p>0.05). There were statistical differences in the 14 of the total 30 measured points in the 5 mm slice thickness and 22 in the 7 mm slice thickness. The facial soft tissue thickness measurement using 3D images of 7 mm slice thickness is acceptable clinically, but those of 5 mm slice thickness is recommended for the more accurate measurement

Taurine content of tissues of irradiated rats

International Nuclear Information System (INIS)

Akhalaya, M.Ya.; Bogatyrev, G.P.; Kudryashov, Yu.B.; Yartsev, E.I.

1976-01-01

The taurine content of tissues (liver, stomach, small intestine and spleen) of rats irradiated with doses of 700 and 450 rads has been studied. Phase changes have been found in the taurine content of radiosensitive tissues in the course of radiation injury development

Estimation of soft- and hard-tissue thickness at implant sites

Directory of Open Access Journals (Sweden)

Anil Kumar

2014-01-01

Full Text Available Introduction: Anchorage control is a critical consideration when planning treatment for patients with dental and skeletal malocclusions. To obtain sufficient stability of implants, the thickness of the soft tissue and the cortical-bone in the placement site must be considered; so as to provide an anatomical map in order to assist the clinician in the placement of the implants. Objective: The aim of this study is to evaluate the thickness of soft- and hard-tissue. Materials and Methods: To measure soft tissue and cortical-bone thicknesses, 12 maxillary cross-sectional specimens were obtained from the cadavers, which were made at three maxillary mid-palatal suture areas: The interdental area between the first and second premolars (Group 1, the second premolar and the first molar (Group 2, and the first and second molars (Group 3. Sectioned samples along with reference rulers were digitally scanned. Scanned images were calibrated and measurements were made with image-analysis software. We measured the thickness of soft and hard-tissues at five sectional areas parallel to the buccopalatal cementoenamel junction (CEJ line at 2-mm intervals and also thickness of soft tissue at the six landmarks including the incisive papilla (IP on the palate. The line perpendicular to the occlusal plane was made and measurement was taken at 4-mm intervals from the closest five points to IP. Results: (1 Group 1:6 mm from CEJ in buccal side and 2 mm from CEJ in palatal side. (2 Group 2:8 mm from CEJ in buccal side and 4 mm from CEJ in palatal side. (3 Group 3:8 mm from CEJ in buccal side and 8 mm from CEJ in palatal side. Conclusions: The best site for placement of implant is with thinnest soft tissue and thickest hard tissue, which is in the middle from CEJ in buccal side and closest from CEJ in palatal side in Group 1 and faraway from CEJ in buccal side and closest from CEJ in palatal side in Group 2 and faraway from CEJ in buccal side and faraway from CEJ in palatal

A study on tissue compensator thickness ratio and an application for 4MV X-rays

International Nuclear Information System (INIS)

Kim, Young Bum; Kwon, Young Ho; Jung, Hee Young; Kim, You Hyun

1996-01-01

A radiation beam incident on irregular or sloping surface produces an inhomogeneity of absorbed dose. The use of a tissue compensator can partially correct this dose inhomogeneity. The tissue compensator should be made based on experimentally measured thickness ratio. The thickness ratio depends on beam energy, distance from the tissue compensator to the surface of patient, field size, treatment depth, tissue deficit and other factors. In this study, the thickness ratio was measured for various field size of 5cm x 5cm, 10cm x 10cm, 15cm x 15cm, 20 x 20cm for 4MV X-ray beams. The distance to the compensator from the X-ray target was fixed, 49cm, and measurement depth was 3, 5, 7, 9 cm. For each measurement depth, the tissue deficit was changed from 0 to(measurement depth-1)cm by 1cm increment. As a result, thickness ratio was decreased according to field size and tissue deficit was increased. Use of a representative thickness ratio for tissue compensator, there was 10% difference of absorbed dose but use of a experimentally measured thickness ratio for tissue compensator, there was 2% difference of absorbed dose. Therefore, it can be concluded that the tissue compensator made by experimentally measured thickness ratio can produce good distribution with acceptable inhomogeneity and such tissue compensator can be effectively applied to clinical radiotherapy.

Study on optimizing ultrasonic irradiation period for thick polycrystalline PZT film by hydrothermal method.

Science.gov (United States)

Ohta, Kanako; Isobe, Gaku; Bornmann, Peter; Hemsel, Tobias; Morita, Takeshi

2013-04-01

The hydrothermal method utilizes a solution-based chemical reaction to synthesize piezoelectric thin films and powders. This method has a number of advantages, such as low-temperature synthesis, and high purity and high quality of the product. In order to promote hydrothermal reactions, we developed an ultrasonic assisted hydrothermal method and confirmed that it produces dense and thick lead-zirconate-titanate (PZT) films. In the hydrothermal method, a crystal growth process follows the nucleation process. In this study, we verified that ultrasonic irradiation is effective for the nucleation process, and there is an optimum irradiation period to obtain thicker PZT films. With this optimization, a 9.2-μm-thick PZT polycrystalline film was obtained in a single deposition process. For this film, ultrasonic irradiation was carried out from the beginning of the reaction for 18 h, followed by a 6 h deposition without ultrasonic irradiation. These results indicate that the ultrasonic irradiation mainly promotes the nucleation process. Copyright © 2012 Elsevier B.V. All rights reserved.

On the participation of irradiated tissues in the formation of limb regenerate in axolotls

International Nuclear Information System (INIS)

Tuchkova, S.Ya.

1976-01-01

The aim of the study was to obtain further information on the participation of irradiated tissue cells in formation of regenerated limbs after X-irradiation of axolotls and experimental restoration of the regenerational ability. Cells of irradiated tissues were labeled with H 3 -thymidine; the presence of the label in regenerated tissues would be indicative of participation of irradiated cells in the regeneration process. Irradiation dose was 700 R. 30 axolotls with irradiated limbs were intramuscularly injected with rat muscle homogenate into the right limb once a day beginning from the day of treatment. 15 similarly irradiated animals which did not receive homogenate served as a control. The authors concluded that the presence of highly labeled cells in regenerated tissues was likely to indicate the participation of irradiated tissue cells in regeneration of the limb. However, the quantitative contribution of such cells was impossible to determine since remaining irradiated tissues of the organ contained mostly unlabeled cells. It was also impossible to rule out the possibility of cell migration from non-irradiated tissues [ru

Splitting diffraction peak in different thickness LL-interferometer and determination of thickness of damaged layer induced by electron irradiation of plates

International Nuclear Information System (INIS)

Truni, K.G.; Sedrakyan, A.G.; Papoyan, A.A.; Bezirganyan, P.A.

1988-01-01

Amplitude of twice reflected beam is calculated analytically, oscillatory dependence of peak intensity in the centre of diffraction image on the small variations in thickness is shown. The expression, clearly binding the splitting value of diffraction peak with variation in thickness of the interferometer plates, is received. The effect of variation in thickness on the splitting value of focal line is studied experimentally in case of irradiation of the equal-arm Π-shaped interferometer blocks by fast electron flow, thickness of the originated damaged layers are determined

Analysis of feature stability for laser-based determination of tissue thickness

Science.gov (United States)

Ernst, Floris; Schweikard, Achim; Stüber, Patrick; Bruder, Ralf; Wagner, Benjamin; Wissel, Tobias

2015-03-01

Localisation of the cranium is necessary for accurate stereotactic radiotherapy of malign lesions in the brain. This is achieved by immobilizing the patient's head (typically by using thermoplastic masks, bite blocks or combinations thereof) and x-ray imaging to determine the actual position of the patient with respect to the treatment device. In previous work we have developed a novel method for marker-less and non-invasive tracking of the skull using a combination of laser-based surface triangulation and the analysis of backscattered feature patterns of a tightly collimated NIR laser beam scanned over the patient's forehead. An HDR camera is coupled into the beam path of the laser scanning system to acquire one image per projected laser point. We have demonstrated that this setup is capable of accurately determining the tissue thickness for each triangulation point and consequently allows detecting the surface of the cranial bone with sub-millimetre accuracy. Typical clinical settings (treatment times of 15-90 min) require feature stability over time, since the determination of tissue thickness is achieved by machine learning methods trained on initial feature scans. We have collected initial scans of the forehead as well as long-term backscatter data (20 images per seconds over 30 min) from five subjects and extracted the relevant tissue features from the image streams. Based on the knowledge of the relationship between the tissue feature values and the tissue thickness, the analysis of the long-term data showed that the noise level is low enough to allow robust discrimination of tissue thicknesses of 0.5 mm.

Effect of whole body irradiation on different tissues

International Nuclear Information System (INIS)

Casati, V.; Nardino, A.; Tomassi, I.; Becciolini, A.; Rizzi, M.; Martelli, T.

1979-01-01

The uptake and elimination of 14 C leucine were analysed in controls and in rats irradiated 2 h before injection with 8 Gy whole-body irradiation. Plasma, small intestine, kidney and skin were assayed after homogenization for TCA soluble and insoluble activity curves. In highly differentiated tissues with poor proliferative activity and low protein turnover, the uptake and elimination of the tracer did not appear to be affected by irradiation. In the small intestine differences between control and irradiated animals seemed significant. (Auth.)

Histological observation on dental hard tissue irradiated by ultrashort-pulsed laser

Science.gov (United States)

Uchizono, Takeyuki; Awazu, Kunio; Igarashi, Akihiro; Kato, Junji; Hirai, Yoshito

2006-04-01

In the field of dentistry, effectiveness of USPL irradiation is researched because USPL has less thermal side effect to dental hard tissue. In this paper, we observed morphological change and optical change of dental hard tissue irradiated by USPL for discussing the safety and effectiveness of USPL irradiation to dental hard tissues. Irradiated samples were crown enamel and root dentin of bovine teeth. Lasers were Ti:sapphire laser, which had pulse duration (P d)of 130 fsec and pulse repetition rate (f) of 1kHz and wavelength (l) of 800nm, free electron laser (FEL), which had P d of 15 μsec and f of 10Hz and wavelength of 9.6μm, and Er:YAG laser, which had P d of 250 μsec and f of 10Hz and wavelength of 2.94μm. After laser irradiation, the sample surfaces and cross sections were examined with SEM and EDX. The optical change of samples was observed using FTIR. In SEM, the samples irradiated by USPL had sharp and accurate ablation with no crack and no carbonization. But, in FEL and Er:YAG laser, the samples has rough ablation with crack and carbonization. It was cleared that the P/Ca ratio of samples irradiated by USPL had same value as non-irradiated samples. There was no change in the IR absorption spectrum between samples irradiated by USPL and non-irradiated sample. But, they of samples irradiated by FEL and Er:YAG laser, however, had difference value as non-irradiated samples. These results showed that USPL might be effective to ablate dental hard tissue without thermal damage.

Measurement of facial soft tissues thickness using 3D computed tomographic images

Energy Technology Data Exchange (ETDEWEB)

Jeong, Ho Gul; Kim, Kee Deog; Shin, Dong Won; Hu, Kyung Seok; Lee, Jae Bum; Park, Hyok; Park, Chang Seo [Yonsei Univ. Hospital, Seoul (Korea, Republic of); Han, Seung Ho [Catholic Univ. of Korea, Seoul (Korea, Republic of)

2006-03-15

To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. There were no statistically significant differences between the direct measurements and those using the 3D images(p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissue thickness more easily in forensic science and anthropology.

Measurement of facial soft tissues thickness using 3D computed tomographic images

International Nuclear Information System (INIS)

Jeong, Ho Gul; Kim, Kee Deog; Shin, Dong Won; Hu, Kyung Seok; Lee, Jae Bum; Park, Hyok; Park, Chang Seo; Han, Seung Ho

2006-01-01

To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. There were no statistically significant differences between the direct measurements and those using the 3D images(p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissue thickness more easily in forensic science and anthropology

Effect of irradiation on the dental pulp tissues in streptozotocin-induced diabetic rats

International Nuclear Information System (INIS)

Kang, Ho Duk; Hwang, Eui Hwan; Lee, Sang Rae

2005-01-01

To observe the histological changes in the pulp tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups : control, diabetes, irradiation, and diabetes-irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in control and irradiation groups were injected with citrate buffer only. After 5 days, the head and neck region of the rats in irradiation and diabetes-irradiation groups were irradiated with a single absorbed dose of 10 Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. In the diabetes group, capillary dilatation was observed. However, there was no obvious morphologic alteration of the odontoblasts. In the irradiation group, generalized necrosis of the dental pulp tissues was observed. Vacuolation of the odontoblasts and dilatation of the capillaries were noted in the early experimental phases. In the diabetes-irradiation group, generalized degeneration of the dental pulp tissues was observed. Vacuolation of the dental pulp cells and the odontoblasts was noted in the late experimental phases. This experiment suggest that dilatation of the capillaries in the dental pulp tissue is induced by diabetic state, and generalized degeneration of the dental pulp tissues is induced by irradiation of the diabetic group.

Skin color and tissue thickness effects on transmittance, reflectance, and skin temperature when using 635 and 808 nm lasers in low intensity therapeutics.

Science.gov (United States)

Souza-Barros, Leanna; Dhaidan, Ghaith; Maunula, Mikko; Solomon, Vaeda; Gabison, Sharon; Lilge, Lothar; Nussbaum, Ethne L

2018-04-01

To examine the role of skin color and tissue thickness on transmittance, reflectance, and skin heating using red and infrared laser light. Forty volunteers were measured for skin color and skin-fold thickness at a standardized site near the elbow. Transmittance, reflectance and skin temperature were recorded for energy doses of 2, 6, 9, and 12 Joules using 635 nm (36 mW) and 808 nm (40 mW) wavelength laser diodes with irradiances within American National Standards Institute safety guidelines (4.88 mm diameter, 0.192 W/cm 2 and 4.88 mm diameter, 0.214 W/cm 2 , respectively). The key factors affecting reflectance to an important degree were skin color and wavelength. However, the skin color effects were different for the two wavelengths: reflectance decreased for darker skin with a greater decrease for red light than near infrared light. Transmittance was greater using 808 nm compared with 635 nm. However, the effect was partly lost when the skin was dark rather than light, and was increasingly lost as tissue thickness increased. Dose had an increasing effect on temperature (0.7-1.6°C across the 6, 9, and 12 J doses); any effects of wavelength, skin color, and tissue thickness were insignificant compared to dose effects. Subjects themselves were not aware of the increased skin temperature. Transmittance and reflectance changes as a function of energy were very small and likely of no clinical significance. Absorption did not change with higher energy doses and increasing temperature. Skin color and skin thickness affect transmittance and reflectance of laser light and must be accounted for when selecting energy dose to ensure therapeutic effectiveness at the target tissue. Skin heating appears not to be a concern when using 635 and 808 nm lasers at energy doses of up to 12 J and irradiance within American National Standards Institute standards. Photobiomodulation therapy should never exceed the American National Standards Institute

Correlation of blister diameter and blister skin thickness in helium-ion-irradiated Nb

International Nuclear Information System (INIS)

Das, S.K.; Kaminsky, M.; Fenske, G.

1979-01-01

A systematic study of the correlation between blister diameter and blister skin thickness has been performed for helium-ion irradiation of monocrystalline and polycrystalline Nb for ion energies ranging from 20 to 500 keV. The results indicate that a relationship Datsub mpatproportionaltatsup 1.50at between the most probable blister diameter, Datsub mpat, and blister skin thickness, t, which has been suggested by other authors, does not exist for the various types of Nb targets studied. For example, for room-temperature irradiation of annealed polycrystalline Nb the experimentally determined relationship is Datsub mpat<10.3tatsup 1.22at. Furthermore, the D-t relationship was found to depend on the irradiation temperature in contrast to theoretical predictions by the lateral stress model of blister formation. These results do not appear to support the lateral stress model which predicts the relationship Dproportionaltatsup 1.5at. However, the experimentally determined relationships can be explained in part by the gas pressure model of blister formation

The study on facial soft tissue thickness using Han population in Xinjiang.

Science.gov (United States)

Wang, Jierui; Zhao, Xi; Mi, Congbo; Raza, Iqbal

2016-09-01

Facial profile is an important aspect in physical anthropology, forensic science, and cosmetic research. Thus, facial soft tissue measurement technology plays a significant role in facial restoration. A considerable amount of work has investigated facial soft tissue thickness, which significantly varies according to gender, age, and race. However, only few studies have considered the nutritional status of the investigated individuals. Moreover, no sufficient research among Chinese ethnic groups, particularly Xinjiang population in China, is currently available. Hence, the current study investigated the adaptability of facial soft tissue to the underlying hard tissue among young adults of Han population in Xinjiang, China; the analysis was performed on the basis of gender, skeletal class, and body mass index (BMI). Measurements were obtained from the lateral cephalometric radiographs of 256 adults aged 18-26 years old. Differences in soft tissue thickness were observed between genders and among skeletal classes. With regard to gender, significant differences in soft tissue thickness were found at rhinion, glabella, subnasale, stomion, labrale superius, pogonion, and gnathion among different BMI groups. Thus, nutritional status should be considered when reconstructing an individual's facial profile. Results showed that the thinnest and thickest craniofacial soft tissues existed in rhinion and lip regions, respectively. Overall, this research provides valuable data for forensic facial reconstruction and identification of young adults in Xinjiang, China. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Accumulation of DNA Double-Strand Breaks in Normal Tissues After Fractionated Irradiation

International Nuclear Information System (INIS)

Ruebe, Claudia E.; Fricke, Andreas; Wendorf, Juliane; Stuetzel, Annika; Kuehne, Martin; Ong, Mei Fang; Lipp, Peter; Ruebe, Christian

2010-01-01

Purpose: There is increasing evidence that genetic factors regulating the recognition and/or repair of DNA double-strand breaks (DSBs) are responsible for differences in radiosensitivity among patients. Genetically defined DSB repair capacities are supposed to determine patients' individual susceptibility to develop adverse normal tissue reactions after radiotherapy. In a preclinical murine model, we analyzed the impact of different DSB repair capacities on the cumulative DNA damage in normal tissues during the course of fractionated irradiation. Material and Methods: Different strains of mice with defined genetic backgrounds (SCID -/- homozygous, ATM -/- homozygous, ATM +/- heterozygous, and ATM +/+ wild-type mice) were subjected to single (2 Gy) or fractionated irradiation (5 x 2 Gy). By enumerating γH2AX foci, the formation and rejoining of DSBs were analyzed in organs representative of both early-responding (small intestine) and late-responding tissues (lung, kidney, and heart). Results: In repair-deficient SCID -/- and ATM -/- homozygous mice, large proportions of radiation-induced DSBs remained unrepaired after each fraction, leading to the pronounced accumulation of residual DNA damage after fractionated irradiation, similarly visible in early- and late-responding tissues. The slight DSB repair impairment of ATM +/- heterozygous mice was not detectable after single-dose irradiation but resulted in a significant increase in unrepaired DSBs during the fractionated irradiation scheme. Conclusions: Radiation-induced DSBs accumulate similarly in acute- and late-responding tissues during fractionated irradiation, whereas the whole extent of residual DNA damage depends decisively on the underlying genetically defined DSB repair capacity. Moreover, our data indicate that even minor impairments in DSB repair lead to exceeding DNA damage accumulation during fractionated irradiation and thus may have a significant impact on normal tissue responses in clinical

Analytical formulae in fractionated irradiation of normal tissue

International Nuclear Information System (INIS)

Kozubek, S.

1982-01-01

The new conception of the modeling of the cell tissue kinetics after fractionated irradiation is proposed. The formulae given earlier are compared with experimental data on various normal tissues and further adjustments are considered. The tissues are shown to exhibit several general patterns of behaviour. The repopulation, if it takes place, seems to start after some time, independently of fractionation in first approximation and can be treated as simple autogenesis. The results are compared with the commonly used NSD conception and the well-known Cohen cell tissue kinetic model

Measurement of subcutaneous adipose tissue thickness by near-infrared

International Nuclear Information System (INIS)

Wang, Yu; Ying, Zeqiang; Hao, Dongmei; Zhang, Song; Yang, Yimin; Zeng, Yanjun

2013-01-01

Obesity is strongly associated with the risks of diabetes and cardiovascular disease, and there is a need to measure the subcutaneous adipose tissue (SAT) layer thickness and to understand the distribution of body fat. A device was designed to illuminate the body parts by near-infrared (NIR), measure the backscattered light, and predict the SAT layer thickness. The device was controlled by a single-chip microcontroller (SCM), and the thickness value was presented on a liquid crystal display (LCD). There were 30 subjects in this study, and the measurements were performed on 14 body parts for each subject. The paper investigated the impacts of pressure and skin colour on the measurement. Combining with principal component analysis (PCA) and support vector regression (SVR), the measurement accuracy of SAT layer thickness was 89.1 % with a mechanical caliper as reference. The measuring range was 5–11 mm. The study provides a non-invasive and low-cost technique to detect subcutaneous fat thickness, which is more accessible and affordable compared to other conventional techniques. The designed device can be used at home and in community.

Effect of irradiation on the periodontal tissues in streptozotocin-induced diabetic rats

International Nuclear Information System (INIS)

Park, Dong Sin; Hwang, Eui Hwan; Lee, Sang Rae

2005-01-01

To observe the histopathological changes in the periodontal tissues of mandibular molars in streptozotocin-induced diabetic rats after irradiation. The male Sprague-Dawley rats weighing approximately 250 gm were divided into four groups; control, diabetes, irradiation, and diabetes - irradiation groups. Diabetes mellitus was induced in the rats by injecting streptozotocin. Rats in the control and irradiation groups were injected with citrate buffer only. After 5 days, the head and neck region of the rats in irradiation and diabetes - irradiation groups were irradiated with a single absorbed dose of 10 Gy. All the rats were sacrificed at 3, 7, 14, 21, and 28 days after irradiation. The specimen including the mandibular molars were sectioned and observed using a histopathological method. In the diabetes group, osteoclastic activity was observed in the alveolar bone and the root throughout the period of experiment. Also, osteoblastic and fibroblastic activities were markedly decreased. In the irradiation group, the osteoclasts were observed in the alveolar bone and the dilated capillaries were increased in the early experimental phases. However, vigorous osteoblastic activity was noted in the late experimental phases. In the diabetes- irradiation group, osteoblastic activity in the alveolar bone and the root was observed in the early experimental phases. However, there were no resorption and osteoblastic activity in the alveolar bone and the root in the late experimental phases, and obvious atrophic change of fibrous tissues was noted. This experiment suggests that osteoblastic activity was caused by irradiation in the late experimental phases, but atrophic change of the periodontal ligament tissues was induced after irradiation in diabetic state.

The role of irradiated tissue during pattern formation in the regenerating limb

International Nuclear Information System (INIS)

Maden, M.

1979-01-01

The amphibian limb regeneration blastema is used here to examine whether irradiated, non-dividing tissue can participate in the development of new patterns of morphogenesis. Irradiated blastemas were rotated 180 0 on normal stumps and normal blastemas rotated on irradiated stumps. In both cases supernumerary elements developed from the unirradiated tissue. The supernumeraries were defective but this did not seem to be due to a lack of tissue. Rather it suggested that this could be a realization of compartments in vertebrate development or simply reflect the limited regulative ability of the blastema. The results are also discussed in relation to a recent model of pattern formation. (author)

Effect of irradiation on glycosaminoglycans connect in rat tissue

Energy Technology Data Exchange (ETDEWEB)

Drozdz, M; Kucharz, E; Glowacki, A; Zylka, J

1981-01-01

Glycosaminoglycan (GAGs) fractions were determined in tissues (skin, liver, lungs, aortic wall) and blood serum of rats irradiated with a single dose of 500 R. An increase of total GAGs as well as changes in the fractions were found in the tissues and urine of exposed rats.

Changes in lipolysis in rat adipose tissue during continuous irradiation

International Nuclear Information System (INIS)

Sedlakova, A.; Ahlers, I.; Praslicka, M.

1980-01-01

Changes in lipolysis were monitored by measuring the release of non-esterified fatty acids (NEFA) and glycerol under basal conditions and after stimulation with L-noradrenaline in rat adipose tissue in the course of continuous irradiation with daily gamma doses of 0.57 Gy (60 R) for 50 days. As compared with the control animals, lipolysis in the irradiated rats was lower on days 3 to 14, and higher on days 21 to 25 to 32 and at the end of the screening period (day 50) of continuous irradiation. The changes in lipolysis in the course of irradiation reflected individual stages of the general adaptation syndrome. Many changes were modified by the effect of non-specific factors due to the experimental field and the starvation prior to the analysis. Changes in lipolysis were connected with changes in the mobilization of fatty acids and the concentrations of NEFA in white adipose tissue with changes in serum lipids predominantly in the period of 21 to 25 days of continuous irradiation. (author)

Histopathological investigation of radiation necrosis. Coagulation necrosis in the irradiated and non-irradiated brain tumors and in the normal brain tissue

Energy Technology Data Exchange (ETDEWEB)

Nakamura, N [Niigata Univ. (Japan). Brain Research Inst.

1977-01-01

Eighty four irradiated tumors (including 59 gliomas) and the surrounding brain tissue were analyzed. In 'normal' brain tissue, typical coagulation necrosis attributable to irradiation was observed in the cerebral white matter, presenting a whitish-yellow color but no remarkable changes in volume. Histologically there was complete desintegration of myelin and axon. Vascular changes included hyalinous thickening, concentric cleavage, fibrinoid degeneration, adventitial fibrosis and edema of small arteries, fibrin thrombi or occlusion of arterioles and capillaries, and telangiectasia of small veins and venules. While other tumors showed hyalinous or fibrous scar tissue and decrease in volume, the gliomas maintained their original volume without residual tumor cells. Massive coagulation necrosis was occasionally found even in full volume, non-irradiated gliomas (controls), although the changes were fewer and not so varied as in typical radiation necrosis. With small dosages, it was difficult to judge whether the necrosis was caused by irradiation or occurred spontaneously. Coagulation necrosis in tumor tissue was found in 25 of 59 cases (42%) of irradiated gliomas, but in only 2 of 49 cases (4%) of the nonirradiated gliomas. In 49 cases no coagulation necrosis of the surrounding tissue was found. Although histopathological judgement is difficult, it is suggested that there is a significant correlation between coagulation necrosis and irradiation. Discussion of the relationship between coagulation necrosis and NSD (nominal standard dose) led to the conclusion that coagulation necrosis will not be caused by irradiation of less than 1400 rets in NSD.

Factors that influence soft tissue thickness over the greater trochanter: application to understanding hip fractures.

Science.gov (United States)

Levine, Iris C; Minty, Lauren E; Laing, Andrew C

2015-03-01

Fall-related hip injuries are a concern for the growing population of older adults. Evidence suggests that soft tissue overlying the greater trochanter attenuates the forces transmitted to the proximal femur during an impact, reducing mechanical risk of hip fracture. However, there is limited information about the factors that influence trochanteric soft tissue thickness. The current study used ultrasonography and electromyography to determine whether trochanteric soft tissue thickness could be quantified reproducibly and whether it was influenced by: (1) gender; (2) hip postures associated with potential falling configurations in the sagittal plane (from 30° of extension to 60° of flexion, at 15° intervals), combined adduction-flexion, and combined adduction-extension; and (3) activation levels of the tensor fascia lata (TFL) and gluteus medius (GM) muscles. Our results demonstrated that soft tissue thickness can be measured reliably in nine hip postures and three muscle activation conditions (for all conditions, ICC >0.98). Mean (SD) thickness in quiet stance was 2.52 cm. Thickness was 27.0% lower for males than females during quiet stance. It was 16.4% greater at maximum flexion than quiet standing, 27.2% greater at maximum extension, and 12.5% greater during combined adduction-flexion. However, there was no significant difference between combined adduction-extension and quiet standing. Thickness was not affected by changes in muscle activity. Forces applied to the femoral neck during a lateral fall decrease as trochanteric soft tissue thickness increases; gender and postural configuration at impact could influence the loads applied to the proximal femur (and thus hip fracture risk) during falls on the hip. © 2014 Wiley Periodicals, Inc.

Dual-energy digital mammography: Calibration and inverse-mapping techniques to estimate calcification thickness and glandular-tissue ratio

International Nuclear Information System (INIS)

Kappadath, S. Cheenu; Shaw, Chris C.

2003-01-01

Breast cancer may manifest as microcalcifications in x-ray mammography. Small microcalcifications, essential to the early detection of breast cancer, are often obscured by overlapping tissue structures. Dual-energy imaging, where separate low- and high-energy images are acquired and synthesized to cancel the tissue structures, may improve the ability to detect and visualize microcalcifications. Transmission measurements at two different kVp values were made on breast-tissue-equivalent materials under narrow-beam geometry using an indirect flat-panel mammographic imager. The imaging scenario consisted of variable aluminum thickness (to simulate calcifications) and variable glandular ratio (defined as the ratio of the glandular-tissue thickness to the total tissue thickness) for a fixed total tissue thickness--the clinical situation of microcalcification imaging with varying tissue composition under breast compression. The coefficients of the inverse-mapping functions used to determine material composition from dual-energy measurements were calculated by a least-squares analysis. The linear function poorly modeled both the aluminum thickness and the glandular ratio. The inverse-mapping functions were found to vary as analytic functions of second (conic) or third (cubic) order. By comparing the model predictions with the calibration values, the root-mean-square residuals for both the cubic and the conic functions were ∼50 μm for the aluminum thickness and ∼0.05 for the glandular ratio

Prediction model for oxide thickness on aluminum alloy cladding during irradiation

International Nuclear Information System (INIS)

Kim, Yeon Soo; Hofman, G.L.; Hanan, N.A.; Snelgrove, J.L.

2003-01-01

An empirical model predicting the oxide film thickness on aluminum alloy cladding during irradiation has been developed as a function of irradiation time, temperature, heat flux, pH, and coolant flow rate. The existing models in the literature are neither consistent among themselves nor fit the measured data very well. They also lack versatility for various reactor situations such as a pH other than 5, high coolant flow rates, and fuel life longer than ∼1200 hrs. Particularly, they were not intended for use in irradiation situations. The newly developed model is applicable to these in-reactor situations as well as ex-reactor tests, and has a more accurate prediction capability. The new model demonstrated with consistent predictions to the measured data of UMUS and SIMONE fuel tests performed in the HFR, Petten, tests results from the ORR, and IRIS tests from the OSIRIS and to the data from the out-of-pile tests available in the literature as well. (author)

Time-resolved analysis of thickness-dependent dewetting and ablation of silver films upon nanosecond laser irradiation

International Nuclear Information System (INIS)

Qi, Dongfeng; Paeng, Dongwoo; Yeo, Junyeob; Kim, Eunpa; Wang, Letian; Grigoropoulos, Costas P.; Chen, Songyan

2016-01-01

Nanosecond pulsed laser dewetting and ablation of thin silver films is investigated by time-resolved imaging. Laser pulses of 532 nm wavelength and 5 ns temporal width are irradiated on silver films of different thicknesses (50 nm, 80 nm, and 350 nm). Below the ablation threshold, it is observed that the dewetting process does not conclude until 630 ns after the laser irradiation for all samples, forming droplet-like particles in the spot central region. At higher laser intensities, ablative material removal occurs in the spot center. Cylindrical rims are formed in the peripheral dewetting zone due to the solidification of transported matter at about 700 ns following the laser pulse exposure. In addition to these features, droplet fingers are superposed upon irradiation of 350-nm thick silver films with higher intensity.

Time-resolved analysis of thickness-dependent dewetting and ablation of silver films upon nanosecond laser irradiation

Energy Technology Data Exchange (ETDEWEB)

Qi, Dongfeng [Laser Thermal Laboratory, Department of Mechanical Engineering, University of California, Berkeley, California 94720-1740 (United States); Semiconductor Photonics Research Center, Department of Physics, Xiamen University, Xiamen 361005 (China); Paeng, Dongwoo; Yeo, Junyeob; Kim, Eunpa; Wang, Letian; Grigoropoulos, Costas P., E-mail: cgrigoro@berkeley.edu [Laser Thermal Laboratory, Department of Mechanical Engineering, University of California, Berkeley, California 94720-1740 (United States); Chen, Songyan [Semiconductor Photonics Research Center, Department of Physics, Xiamen University, Xiamen 361005 (China)

2016-05-23

Nanosecond pulsed laser dewetting and ablation of thin silver films is investigated by time-resolved imaging. Laser pulses of 532 nm wavelength and 5 ns temporal width are irradiated on silver films of different thicknesses (50 nm, 80 nm, and 350 nm). Below the ablation threshold, it is observed that the dewetting process does not conclude until 630 ns after the laser irradiation for all samples, forming droplet-like particles in the spot central region. At higher laser intensities, ablative material removal occurs in the spot center. Cylindrical rims are formed in the peripheral dewetting zone due to the solidification of transported matter at about 700 ns following the laser pulse exposure. In addition to these features, droplet fingers are superposed upon irradiation of 350-nm thick silver films with higher intensity.

Gamma-ray irradiation and post-irradiation at room and elevated temperature response of pMOS dosimeters with thick gate oxides

Directory of Open Access Journals (Sweden)

Pejović Momčilo M.

2011-01-01

Full Text Available Gamma-ray irradiation and post-irradiation response at room and elevated temperature have been studied for radiation sensitive pMOS transistors with gate oxide thickness of 100 and 400 nm, respectively. Their response was followed based on the changes in the threshold voltage shift which was estimated on the basis of transfer characteristics in saturation. The presence of radiation-induced fixed oxide traps and switching traps - which lead to a change in the threshold voltage - was estimated from the sub-threshold I-V curves, using the midgap technique. It was shown that fixed oxide traps have a dominant influence on the change in the threshold voltage shift during gamma-ray irradiation and annealing.

An Experimental Study on the Effects of Co-60 Irradiation on the Rat Tongue Tissue

Energy Technology Data Exchange (ETDEWEB)

Lee, Seon Kee; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyung Hee University, Seoul (Korea, Republic of)

1990-02-15

It is known that radiation therapy is a kind of treatment choices of the maxillofacial tumors. This study is designed to investigate the effects of irradiation on rat's tongue tissues as functional tissues which relate to taste, mastication, and pronunciation. 88 rats (Sprague Dawley branch, male) were divided into control group of 4 and experimental group of 84. Experimental group was singly exposed to Co-60 irradiation with 8, 13, 18 Gy in the head and neck region. Animals were sacrificed on 1 hour, 3 hours, 6 hours, 1 day, 3 days, 7 days, and 28 days after the irradiation. The specimens were observed by histopathological examination employing H-E stain and Van-Gieson stain. The results were follows; 1. The tongue tissue were severely swollen on the 1 hour after irradiation, but gradually decreased in course of time. 2. The basal cells of epithelium of tongue proliferated at initial stage of irradiation, but gradually decreased. The Keratin layer were gradually increased. 4. The tissue changes after irradiation were gradually increased by the degree of irradiation.

Surgical performance of a 405-nm diode laser in treatment of soft tissue

International Nuclear Information System (INIS)

Kato, J; Akashi, G; Moriya, K; Hirai, Y; Hatayama, H; Inoue, A; Miyazaki, H

2008-01-01

The study was conducted to evaluate the surgical performance of a 405-nm diode laser ex vivo. The experiments were carried out using tuna tissue, which was irradiated with a 405-nm diode laser at output powers of 400 mW (694 W/cm 2 ) to 1 W (1735 W/cm 2 ) on a motorized stage moving at a rate of 1 mm/sec. As a control, a 920-nm diode laser was used with the same irradiation conditions. After irradiation, the thickness of ablation and coagulation was measured by stereoscopic microscopy and evaluated statistically. Ablation and coagulation zones were obtained with 405-nm laser irradiation, but not with irradiation at 920 nm. Ablation depth increased significantly with output power and a thick coagulation zone was observed with 405-nm irradiation. The 405-nm diode laser performed well for incising and coagulating soft tissue at a low power density

Chitosan Dermal Substitute and Chitosan Skin Substitute Contribute to Accelerated Full-Thickness Wound Healing in Irradiated Rats

Directory of Open Access Journals (Sweden)

Abu Bakar Mohd Hilmi

2013-01-01

Full Text Available Wounds with full-thickness skin loss are commonly managed by skin grafting. In the absence of a graft, reepithelialization is imperfect and leads to increased scar formation. Biomaterials can alter wound healing so that it produces more regenerative tissue and fewer scars. This current study use the new chitosan based biomaterial in full-thickness wound with impaired healing on rat model. Wounds were evaluated after being treated with a chitosan dermal substitute, a chitosan skin substitute, or duoderm CGF. Wounds treated with the chitosan skin substitute showed the most re-epithelialization (33.2 ± 2.8%, longest epithelial tongue (1.62 ± 0.13 mm, and shortest migratory tongue distance (7.11 ± 0.25 mm. The scar size of wounds treated with the chitosan dermal substitute (0.13 ± 0.02 cm and chitosan skin substitute (0.16 ± 0.05 cm were significantly decreased (P<0.05 compared with duoderm (0.45 ± 0.11 cm. Human leukocyte antigen (HLA expression on days 7, 14, and 21 revealed the presence of human hair follicle stem cells and fibroblasts that were incorporated into and surviving in the irradiated wound. We have proven that a chitosan dermal substitute and chitosan skin substitute are suitable for wound healing in full-thickness wounds that are impaired due to radiation.

Cellular localization of peptide hydrolases in chicken embryo tissues and influence of gamma irradiation on their activity

Energy Technology Data Exchange (ETDEWEB)

Khristov, D; Marinopolski, G

1975-01-01

Studied was the influence of chicken embryo irradiation at 600 R and 1000 R gamma rays on the activity of tissue peptide hydrolases in mitochondrial-lysosomal, microsomal and supernatant (cell hyaloplasm) cell fractions. The investigation was performed 50 to 168 hours post irradiation. The wole tissue (of the whole embryo) was examined following irradiation of 4-day-old embryos whose liver, muscle and brain tissues were post irradiation examined on day 12 and 16 of incubation. Prior to treatment, the tissues were threfold rinsed with sucrose solution to eliminate proeinase inhibitors. Lysosome membranes were destroyed by adding 0.5 % desoxycholate. It was found that: Peptide hydrolase activity of mitochondrial-lysosomal cell fractions of tissues of whole 6-day chicken embryos is 4-5 times as high as that of cell hyaloplasm. Peptide hydrolase activity of mitochondrial-lysosomal fractions of liver tissues decreases on day 18 and 19 post incubation, while the same fraction of muscle and brain tissues shows high activity. Peptide hydrolase activity of microsomal fraction and of cell hyaloplasm rises during embryonal development and exceeds the activity of liver tissue mitochondrial fraction. Peptide hydrolase activity of mitochondrial-lysosomal fraction of tissue of whole 6-day-old embryos 50 hours post irradiation is higher than the activity of non-irradiated embryos. Later the activity of this fraction diminishes and on the 168 hr post irradiation it drops below the normal. Microsomal fraction and cell hyaloplasm activity likewise show deviation from the norm. Peptide hydrolase activity of mitochondrial-lysosomal fraction of liver, muscle and brain tissue of 14 and 18-day-old embryos is higher than the control 50 hours post irradiation and then declines. The activity of mitochondrial-lysosomal fraction of embryo brain tissue changes most strikingly on irradiation, while other brain cell fractions change less compared with liver and muscle fractions.

Cellular localization of peptide hydrolases in chicken embryo tissues and influence of gamma irradiation on their activity

International Nuclear Information System (INIS)

Khristov, D.; Marinopolski, G.

1975-01-01

Studied was the influence of chicken embryo irradiation at 600 R and 1000 R gamma rays on the activity of tissue peptide hydrolases in mitochondrial-lysosomal, microsomal and supernatant (cell hyaloplasm) cell fractions. The investigation was performed 50 to 168 hours post irradiation. The wole tissue (of the whole embryo) was examined following irradiation of 4-day-old embryos whose liver, muscle and brain tissues were post irradiation examined on day 12 and 16 of incubation. Prior to treatment, the tissues were threfold rinsed with sucrose solution to eliminate proeinase inhibitors. Lysosome membranes were destroyed by adding 0.5 % desoxycholate. It was found that: Peptide hydrolase activity of mitochondrial-lysosomal cell fractions of tissues of whole 6-day chicken embryos is 4-5 times as high as that of cell hyaloplasm. Peptide hydrolase activity of mitochondrial-lysosomal fractions of liver tissues decreases on day 18 and 19 post incubation, while the same fraction of muscle and brain tissues shows high activity. Peptide hydrolase activity of microsomal fraction and of cell hyaloplasm rises during embryonal development and exceeds the activity of liver tissue mitochondrial fraction. Peptide hydrolase activity of mitochondrial-lysosomal fraction of tissue of whole 6-day-old embryos 50 hours post irradiation is higher than the activity of non-irradiated embryos. Later the activity of this fraction diminishes and on the 168 hr post irradiation it drops below the normal. Microsomal fraction and cell hyaloplasm activity likewise show deviation from the norm. Peptide hydrolase activity of mitochondrial-lysosomal fraction of liver, muscle and brain tissue of 14 and 18-day-old embryos is higher than the control 50 hours post irradiation and then declines. The activity of mitochondrial-lysosomal fraction of embryo brain tissue changes most strikingly on irradiation, while other brain cell fractions change less compared with liver and muscle fractions

Soft tissue thickness of face profile conditioning by dento-skeletal anomalies

Directory of Open Access Journals (Sweden)

Tanić Tatjana

2011-01-01

Full Text Available Introduction. Orthodontic treatment of dento-skeletal anomalies is generally based on the correction of teeth and jaws relationship, while it is expected that soft facial tissue spontaneously adapts to therapeutically achieved relationship and to accompany hard tissue changes. Objective. To establish facial soft tissue thickness conditioning by the presence of dento-skeletal anomalies. Methods. The study was performed at the Dental Clinic of Niš, and involved the analysis of cephalometric rendgenograms in 121 patients, aged 12-18 years, with no previous orthodontical treatment. According to dento-skeletal relationship between teeth and jaws the patients were divided into four groups; class I (control group, class II of division 1, class II of division 2 and class III. The standard analysis of dento-skeletal profile was done according to Steiner and soft tissue profile according to Burstone was done in all. Results. The patients of class II/1 had a significantly thinner upper lip (t=2.650; p<0.05 and thinner upper lip sulcus (t=1.999; p<0.05. The patients of class II/2 had a significantly thicker upper lip (t=2.912; p<0.01, while those of class III had a significantly thinner lower lip (t=3.900; p<0.001. Conclusion. The thickness of facial soft tissue considerably influences facial profile appearance in persons with a dento-skeletal anomaly. Not only do soft tissues adapt to the existing jaws relationship, but can also camouflage present anomalies.

Corneal thickness changes during corneal collagen cross-linking with UV-A irradiation and hypo-osmolar riboflavin in thin corneas

Directory of Open Access Journals (Sweden)

Belquiz Amaral Nassaralla

2013-06-01

Full Text Available PURPOSE: To evaluate the thinnest corneal thickness changes during and after corneal collagen cross-linking treatment with ultraviolet-A irradiation, using hypo-osmolar riboflavin solution in thin corneas. METHODS: Eighteen eyes of 18 patients were included in this study. After epithelium removal, iso-osmolar 0.1% riboflavin solution was instilled to the cornea every 3 minutes for 30 minutes. Hypo-osmolar 0.1% riboflavin solution was then applied every 20 seconds for 5 minutes or until the thinnest corneal thickness reached 400 µm. Ultraviolet-A irradiation was performed for 30 minutes. During irradiation, iso-osmolar 0.1% riboflavin drops were applied every 5 minutes. Ultrasound pachymetry was performed at approximately the thinnest point of the cornea preoperatively, after epithelial removal, after iso-osmolar riboflavin instillation, after hypo-osmolar riboflavin instillation, after ultraviolet-A irradiation, and at 1, 6 and 12 months after treatment. RESULTS: Mean preoperative thinnest corneal thickness was 380 ± 11 µm. After epithelial removal it decreased to 341 ± 11 µm, and after 30 minutes of iso-osmolar 0.1% riboflavin drops, to 330 ± 7.6 µm. After hypo-osmolar 0.1% riboflavin drops, mean thinnest corneal thickness increased to 418 ± 11 µm. After UVA irradiation, it was 384 ± 10 µm. At 1, 6 and 12 months after treatment, it was 372 ± 10 µm, 381 ± 12.7, and 379 ± 15 µm, respectively. No intraoperative, early postoperative, or late postoperative complications were noted. CONCLUSIONS: Hypo-osmolar 0.1% riboflavin solution seems to be effective for swelling thin corneas. The swelling effect is transient and short acting. Corneal thickness should be monitored throughout the procedure. Larger sample sizes and longer follow-up are required in order to make meaningful conclusions regarding safety.

Regional Analysis of Soft Tissue Thickness on Korean Buttocks and Application to Fasciocutaneous Flap Design

Directory of Open Access Journals (Sweden)

Do Yup Kim

2014-03-01

Full Text Available Background Various shapes and designs of the gluteal artery perforator flap have been used for treating sacral pressure sores and reconstructing breasts. To establish the ideal fasciocutaneous flap design for use in the gluteal area, the soft tissue thickness distribution was measured. Methods Twenty-one buttocks of adult Korean cadavers were analyzed through rectangular subfascial dissection. Each buttock was divided horizontally into 10 sections and vertically into 10 sections, and then, the thickness at the corners of the sections was measured. For the sake of comparison and statistical verification with living bodies, computed tomography (CT images of 120 buttocks of patients were randomly selected. Five horizontal sections and 4 vertical sections were made, and the thickness at each corner was recorded. Results According to the dissection and the CT images, the area with the thinnest soft tissues in the buttock was around the posterior superior iliac spine, close to the sacral area. The thickest area was the superolateral area of the buttock, which was 3.24 times and 2.15 times thicker than the thinnest area in the studies on cadaver anatomy and the CT images, respectively. Conclusions The thickness of the soft tissues in the buttocks differed by area. The superolateral area had the thickest soft tissues, and the superomedial area had the thinnest. This study includes information on the distribution of the thickness of the gluteal soft tissues of Koreans. The outcome of this study may contribute to the design of effective local flaps for pressure sore reconstruction and free flaps for breast reconstruction.

Evaluating Superoxide Dismutase (SOD, Glutathione (GSH, Malondialdehyde (MDA and the Histological Changes of the Lung Tissue after γ-Irradiation in Rats

Directory of Open Access Journals (Sweden)

Abolhasan Rezaeyan

2016-09-01

Full Text Available Background & Objective: The lung is a radiosensitive organ and its damage is a dose-limiting factor in radiotherapy. Different side effects such as pneumonia and lung fibrosis are found in patients with thorax irradiation. The objective of the present study is to evaluate the effects of γ-irradiation on acute and chronic injuries of lung tissue in rats. Materials & Methods: 32 rats were divided into two groups. Control group consisted of 14 rats that underwent shame irradiation. In radiation group, 18 rats underwent γ-irradiation. The rats were exposed to γ-irradiation 18 Gy using a single fraction cobalt-60 unit. Eight rats in each group were sacrificed 24 hours after radiotherapy for determining Superoxide Dismutase (SOD, Glutathione (GSH, Malondialdehyde (MDA, and histopathological evaluations. Remained animals were sacrificed eight weeks after radiotherapy for histopathological evaluation. Results: Compared to control group, the level of SOD and GSH significantly decreased and MDA level significantly increased in radiation group 24 hours following irradiation, (p=0.001, p<0.001, p=0.001 respectively. Early histopathological results after 24 hours showed that radiation increases neutrophil, macrophage, and inflammation incidence compared to control group (p<0.05. Late histopathological evaluation after eight weeks revealed significant increase in factors including mast cells, pulmonary edema, vascular thickness, vascular damage, and also inflammation and fibrosis incidence in case group compared to radiation group  (p<0.05. Conclusion: Localized chest radiation with dose of 18 Gy induces changes in oxidative stress indices and histopathological lung tissue damage in short and long term.

Thick tissue diffusion model with binding to optimize topical staining in fluorescence breast cancer margin imaging

Science.gov (United States)

Xu, Xiaochun; Kang, Soyoung; Navarro-Comes, Eric; Wang, Yu; Liu, Jonathan T. C.; Tichauer, Kenneth M.

2018-03-01

Intraoperative tumor/surgical margin assessment is required to achieve higher tumor resection rate in breast-conserving surgery. Though current histology provides incomparable accuracy in margin assessment, thin tissue sectioning and the limited field of view of microscopy makes histology too time-consuming for intraoperative applications. If thick tissue, wide-field imaging can provide an acceptable assessment of tumor cells at the surface of resected tissues, an intraoperative protocol can be developed to guide the surgery and provide immediate feedback for surgeons. Topical staining of margins with cancer-targeted molecular imaging agents has the potential to provide the sensitivity needed to see microscopic cancer on a wide-field image; however, diffusion and nonspecific retention of imaging agents in thick tissue can significantly diminish tumor contrast with conventional methods. Here, we present a mathematical model to accurately simulate nonspecific retention, binding, and diffusion of imaging agents in thick tissue topical staining to guide and optimize future thick tissue staining and imaging protocol. In order to verify the accuracy and applicability of the model, diffusion profiles of cancer targeted and untargeted (control) nanoparticles at different staining times in A431 tumor xenografts were acquired for model comparison and tuning. The initial findings suggest the existence of nonspecific retention in the tissue, especially at the tissue surface. The simulator can be used to compare the effect of nonspecific retention, receptor binding and diffusion under various conditions (tissue type, imaging agent) and provides optimal staining and imaging protocols for targeted and control imaging agent.

The influence of fiber thickness, wall thickness and gap distance on the spiral nanofibrous scaffolds for bone tissue engineering

International Nuclear Information System (INIS)

Wang Junping; Shah, Ami; Yu Xiaojun

2011-01-01

We have developed a 3D nanofibrous spiral scaffold for bone tissue engineering which has shown enhanced cell attachment, proliferation and differentiation compared to traditional cylindrical scaffolds due to the spiral structures and the nanofiber incorporation. Some important parameters of these spiral scaffolds including gap distance, wall thickness and especially fiber thickness are crucial to the performance of the spiral structured scaffolds. In this study, we investigated the fiber thickness, gap distance and wall thickness of the spiral structure on the behavior of osteoblast cells. The human osteoblast cells are seeded on spiral structured scaffolds with various fiber thickness, gap distance and wall thickness and cell attachment, proliferation, differentiation and mineralized matrix deposition on the scaffolds are evaluated. It was found that increasing the thickness of nanofiber layer not only limited the cell infiltration into the scaffolds, but also restrained the osteoblastic cell phenotype development. Moreover, the geometric effect studies indicated that scaffolds with the thinner wall and gap distance 0.2 mm show the best bioactivity for osteoblasts.

Response of tissue lysosomes in Gamma-irradiated rats and possible modulation through diclofenac treatment

International Nuclear Information System (INIS)

Hassan, S.H.S.; Abu-Ghadeer, A.R.M.; Osman, S.A.A.

1995-01-01

The effect of pre and post-irradiation treatment of rats with diclofenac (5 mg kg-1) for modulating the damaging effect of radiation on tissue lysosomes was investigated. The parameters used for this study were the activity level of acid phosphatase (ACP) and acid ribonuclease (RNase) activities, both being hydrolytic enzymes of lysosomes. The activities of ACP and RNase in liver, spleen, intestine, kidney, lung and brain were determined at different times up to 14 days after irradiation (4(Gy). Lysosomal affection was represented by time dependent significant increase in ACP activity in all the tissue homogenates of the investigated organs 3, 7 and 14 days after irradiation at 4 Gy. Gamma irradiation at 4 Gy resulted also in a significant rise in RNase activity of all the tissue organs 3 days post-irradiation. However, gradual decrease in the enzyme activity was recorded 7 and 14 days following irradiation. Diclofenac, pre (as prophylactic) and post (as therapeutic) irradiation treatment of rats successfully restored the increase in the enzymatic activities of ACP and RNase nearly to their normal levels in all the investigated organs. The beneficial effect of diclofenac inhibited completely the effect of irradiation at 14 days post-exposure. 2 figs., 2 tabs

Use of autologous tissue engineered skin to treat porcine full-thickness skin defects

Institute of Scientific and Technical Information of China (English)

CAI Xia; CAO Yi-lin; CUI Lei; LIU Wei; GUAN Wen-xiang

2005-01-01

Objective: To explore a feasible method to repair full-thickness skin defects utilizing tissue engineered techniques. Methods: The Changfeng hybrid swines were used and the skin specimens were cut from the posterior limb girdle region, from which the keratinocytes and fibroblasts were isolated and harvested by trypsin, EDTA, and type II collagenase. The cells were seeded in Petri dishes for primary culture. When the cells were in logarithmic growth phase, they were treated with trypsin to separate them from the floor of the tissue culture dishes. A biodegradable material, Pluronic F-127, was prefabricated and mixed with these cells, and then the cell-Pluronic compounds were seeded evenly into a polyglycolic acid (PGA). Then the constructs were replanted to the autologous animals to repair the full-thickness skin defects. Histology and immunohistochemistry of the neotissue were observed in 1, 2, 4, and 8 postoperative weeks. Results: The cell-Pluronic F-127-PGA compounds repaired autologous full-thickness skin defects 1 week after implantation. Histologically, the tissue engineered skin was similar to the normal skin with stratified epidermis overlying a moderately thick collageneous dermis. Three of the structural proteins in the epidermal basement membrane zone, type IV collagen, laminin, and type VII collagen were detected using immunohistochemical methods. Conclusions: By studying the histology and immunohistochemistry of the neotissue, the bioengineered skin graft holds great promise for improving healing of the skin defects.

Chemical evaluation of strawberry plants produced by tissue culturing of gamma irradiated seedlings

International Nuclear Information System (INIS)

Maraei, R.W.

2007-01-01

studies were conducted to evaluate the influence of gamma irradiation as a supplementary factor precedes tissue culture application on strawberry seedlings (c.v.Rosa Linda). the strawberry seedling were irradiated using 8 doses of co 60 gamma rays 50.75.100.125 ,150,250, 350 and 500 gray. tissue culture technique was applied on irradiated and unirradiated strawberry seedling. different characteristics of plantlets, plant and fruit of strawberry produced from the double treatment (irradiation followed by tissue culture) were studied as well as the early, total and exportable fruit yields. data indicated that, low radiation doses 50,75 and 100 gray increased all morphological and chemical characteristics of the plantlets, plant and fruit of strawberry, whereas radiation doses higher than 100 gray decreased them significantly. moreover 350 and gray were lethal doses. radiation dose 50 gray increased the survival percentage and the length of plantlets by 1.5% and 50% respectively more than the unirradiated treatment in all multiplication stages

MCNP Code in Assessment of Variations of Effective Dose with Torso Adipose Tissue Thickness

International Nuclear Information System (INIS)

Massoud, E.

2005-01-01

The effective dose is the unite used in the field of radiation protection. It is a well defined doubly weighted uantity involving both physical and biological variables. Several factors may induce variation in the effective dose in different individuals of similar exposure data. One of these factors is the variation of adipose tissue thickness in different exposed individuals. This study essentially concenrs the assessment of the possible variation in the effective dose due to variation in the thickness of adipose tissue. The study was done using MCNP4b code to perform mathematical model of the human body depending on that given to the reference man developed by International Commission of Radiological Protection (ICRP), and calculate the effective dose with different thicknessess of adipose tissues. The study includes a comprehensive appraisal of the Monte Cario simulation, the Medical Internal Radiation Dose (MIRD) model for the human body, and the various mathematical considerations involved in the radiation dose calculations for the various pertinent parts of the human body. The radiation energies considered were 80 KeV, 300 KeV and I MeV, applying two exposure positions; anteroposterior (AP), postero-anterior (PA) with different adipose tissue thickness. This study is a theoretical approach based on detailed mathematical calculations of great precision that deals with all considerations involved in the mechanisms of radiation energy absorption in biological system depending on the variation in the densities of the particular in biological system depending on the variation in the densities of the particular tissues. The results obtained indicate that maximum decrease in effective dose occures with the lowest energy at 5cm adipose tissues thickeness for both AP and PA exposure positions. The results obtained were compared to similar work previsouly done using MCNP4 b showing very good agreement

Modification of PLGA Nanofibrous Mats by Electron Beam Irradiation for Soft Tissue Regeneration

Directory of Open Access Journals (Sweden)

Jae Baek Lee

2015-01-01

Full Text Available Biodegradable poly(lactide-co-glycolide (PLGA has found widespread use in modern medical practice. However, the degradation rate of PLGA should be adjusted for specific biomedical applications such as tissue engineering, drug delivery, and surgical implantation. This study focused on the effect of electron beam radiation on nanofibrous PLGA mats in terms of physical properties and degradation behavior with cell proliferation. PLGA nanofiber mats were prepared by electrospinning, and electron beam was irradiated at doses of 50, 100, 150, 200, 250, and 300 kGy. PLGA mats showed dimensional integrity after electron beam irradiation without change of fiber diameter. The degradation behavior of a control PLGA nanofiber (0 kGy and electron beam-irradiated PLGA nanofibers was analyzed by measuring the molecular weight, weight loss, change of chemical structure, and fibrous morphology. The molecular weight of the PLGA nanofibers decreased with increasing electron beam radiation dose. The mechanical properties of the PLGA nanofibrous mats were decreased with increasing electron beam irradiation dose. Cell proliferation behavior on all electron beam irradiated PLGA mats was similar to the control PLGA mats. Electron beam irradiation of PLGA nanofibrous mats is a potentially useful approach for modulating the biodegradation rate of tissue-specific nonwoven nanofibrous scaffolds, specifically for soft tissue engineering applications.

The use of Am-241 as Equivalence Thickness Measurement for Irradiation Room at National institute for Cancer and Malacca Hospital: A Review

International Nuclear Information System (INIS)

Mohd Khalid Matori; Azuhar Ripin; Husaini Salleh

2013-01-01

Lead equivalent thickness measurement of a shielding material in diagnostic radiology is very important to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. The Malaysian Ministry of Health (MOH) has established that the irradiation room must have sufficient shielding thickness, for example for general radiography it must be at least equal to 2.0 mm of Pb, for panoramic dental radiography at least equal to 1.5 mm of Pb and for mammography should be a minimum of 1.0 mm of Pb. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for irradiation room at National Institute for Cancer (IKN) and General Malacca Hospital. Results of measurement of 10 irradiation rooms conducted in 2012 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that almost all the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

Tissue glycogen and blood glucose in irradiated rats. I

International Nuclear Information System (INIS)

Ahlersova, E.; Ahlers, I.; Paulikova, E.; Praslicka, M.

1980-01-01

Fed and starved (overnight) male rats of the Wistar strain were exposed to whole-body irradiation with 14.35 Gy (1500 R) of X-rays. After irradiation and sham-irradiation all animals were starved until examination performed 1, 6, 24, 48 and 72 h after treatment. The concentration of glucose in the blood and the concentration of glycogen in the liver, heart, skeletal muscle, brown and white adipose tissue were determined. The concentrations of blood glucose and liver glycogen were found to increase between 1 and 6 h after irradiation of the starved animals. The most pronounced increase in glycogen concentration in the liver and heart muscle was observed 24 and 48 h after irradiation. A similar increase in the concentration of blood glucose was found between 48 and 72 h after irradiation. The fed and starved irradiated rats reacted differently, particularly between 48 and 72 h; the liver glycogen concentration decreased in the fed animals and remained elevated in the starved ones. Very high values of terminal glycemia were observed in both groups. The accumulation of glycogen in the heart muscle indicates that this organ is sensitive to ionizing radiation. (author)

Light ion irradiation for unfavorable soft tissue sarcoma

International Nuclear Information System (INIS)

Linstadt, D.; Castro, J.R.; Phillips, T.L.; Petti, P.L.; Collier, J.M.; Daftari, I.; Schoethaler, R.; Rayner, A.

1990-09-01

Between 1978 and 1989, 32 patients with unfavorable soft tissue sarcoma underwent light ion (helium, neon) irradiation with curative intent at Lawrence Berkeley Laboratory. The tumors were located in the trunk in 22 patients and head and neck in 10. Macroscopic tumor was present in 22 at the time of irradiation. Two patients had tumors apparently induced by previous therapeutic irradiation. Follow-up times for surviving patients ranged from 4 to 121 months (median 27 months). The overall 3-year actuarial local control rate was 62%; the corresponding survival rate was 50%. The 3-year actuarial control rate for patients irradiated with macroscopic tumors was 48%, while none of the patients with microscopic disease developed local recurrence (100%). The corresponding 3-year actuarial survival rates were 40% (macroscopic) and 78% (microscopic). Patients with retroperitoneal sarcoma did notably well; the local control rate and survival rate were 64% and 62%, respectively. Complications were acceptable; there were no radiation related deaths, while two patients (6%) required operations to correct significant radiation-related injuries. These results appear promising compared to those achieved by low -LET irradiation, and suggest that this technique merits further investigation

500-Gray γ-Irradiation May Increase Adhesion Strength of Lyophilized Cadaveric Split-Thickness Skin Graft to Wound Bed.

Science.gov (United States)

Wei, Lin-Gwei; Chen, Chieh-Feng; Wang, Chi-Hsien; Cheng, Ya-Chen; Li, Chun-Chang; Chiu, Wen-Kuan; Wang, Hsian-Jenn

2017-03-01

Human cadaveric skin grafts are considered as the "gold standard" for temporary wound coverage because they provide a more conductive environment for natural wound healing. Lyophilization, packing, and terminal sterilization with gamma-ray can facilitate the application of cadaveric split-thickness skin grafts, but may alter the adhesion properties of the grafts. In a pilot study, we found that 500 Gy γ-irradiation seemed not to reduce the adherence between the grafts and wound beds. We conducted this experiment to compare the adherences of lyophilized, 500-Gy γ-irradiated skin grafts to that of lyophilized, nonirradiated grafts. Pairs of wounds were created over the backs of Sprague- Dawley rats. Pairs of "lyophilized, 500-Gy γ-irradiated" and "lyophilized, nonirradiated" cadaveric split-thickness skin grafts were fixed to the wound beds. Adhesion strength between the grafts and the wound beds was measured and compared. On post-skin-graft day 7 and day 10, the adhesion strength of γ-irradiated grafts was greater than that of the nonirradiated grafts. Because lyophilized cadaveric skin grafts can be vascularized and the collagen of its dermal component can be remodeled after grafting, the superior adhesion strength of 500-Gy γ-irradiated grafts can be explained by the collagen changes from irradiation.

Tissue glycogen and blood glucose in irradiated rats. II

International Nuclear Information System (INIS)

Ahlersova, E.; Ahlers, I.; Praslicka, M.

1980-01-01

Male rats of the Wistar strain were continuously irradiated with 0.57 Gy (60 R) of gamma rays from a 60 Co source. Irradiation lasted from 1 to 50 days in an experimental field where also control animals shielded from radiation were placed. After a 16 h starvation, the concentration of glucose in the blood and of glycogen in the liver and the heart was determined 1, 3, 7, 14, 21, 25, 32, 39 and 50 days after the beginning of irradiation. The concentration of blood glucose in irradiated rats did not practically differ from that of control animals during the whole period of investigation. The concentration of liver glycogen in irradiated animals was higher than that in the controls during all time intervals, except for day 1. The values of glycogen in the heart muscle were approximately identical in the irradiated and control rats, except for day 21 when they sharply increased in the irradiated animals. In addition to the investigation of blood glucose and tissue glycogen during continuous irradiation, these parameters were studied immediately, and 1, 6 and 12 months after continuous irradiation with a daily exposure of 0.57 Gy (60 R) up to a total exposure of 14.35 Gy (1500 R) of gamma rays. Considerably higher values of liver glycogen were detected in the irradiated rats immediately, and 1 and 6 months after the end of irradiation. (author)

Reduction of dose enhancement from backscattered radiation at tissue-metal interfaces irradiated with 6MeV electrons

International Nuclear Information System (INIS)

Steel, B.

1996-01-01

Due to Electron Back Scatter (EBS), electron irradiation of tissue having under lying lead shielding results in an increase in dose to the tissue on the entrance side of the lead. In these situations dose increases as high as 80% have been reported in the literature. Saunders (British Journal of Radiology, 47, 467-470) noted that dose enhancement is dependent on atomic number of the under lying material approximately as Z 0.5 , and it increases at lower incident electron energies. In our clinic we use 2mm of lead shielding to protect under lying normal tissue when 6MeV electrons are used to treat lips and ears. The object of this study was to find the thinnest combination of materials to reduce the total dose to an acceptable level, with the provisos that; the patient does not come into contact with the lead or other metals, the finished shield could comfortabley be placed between the patient's lip and teeth, and that the materials are sufficietly malleable to work into custom shields. Various combinations of dental wax and aluminium were trialed. That which proved to give the best compromise between reduction of EBS and total shielding thickness was, 1mm of aluminim on the beam side of the lead with 1mm of dental wax to completely enclose the shield. In practice the manufactured shields are approximately 6 mm thick, and are usually not uncomfortable for the patient. (author)

Leptin induction following irradiation is a conserved feature in mammalian epithelial cells and tissues.

Science.gov (United States)

Licursi, Valerio; Cestelli Guidi, Mariangela; Del Vecchio, Giorgia; Mannironi, Cecilia; Presutti, Carlo; Amendola, Roberto; Negri, Rodolfo

2017-09-01

Leptin (LEP) is a peptide hormone with multiple physiological functions. Besides its systemic actions, it has important peripheral roles such as a mitogen action on keratinocytes following skin lesions. We previously showed that LEP mRNA is significantly induced in response to neutron irradiation in mouse skin and that the protein increases in the irradiated epidermis and in the related subcutaneous adipose tissue. In this work, we investigated the post-transcriptional regulation of LEP by miRNAs and the conservation of LEP's role in radiation response in human cells. We used microarray analysis and real-time polymerase chain reaction (RT-PCR) to analyze modulation of miRNAs potentially targeting LEP in mouse skin following irradiation and bioinformatic analysis of transcriptome of irradiated human cell lines and cancer tissues from radiotherapy-treated patients to evaluate LEP expression. We show that a network of miRNAs potentially targeting LEP mRNA is modulated in irradiated mouse skin and that LEP itself is significantly modulated by irradiation in human epithelial cell lines and in breast cancer tissues from radiotherapy-treated patients. These results confirm and extend the previous evidence that LEP has a general and important role in the response of mammalian cells to irradiation.

Histochemical differentiation between unirradiated and gamma-irradiated tissue in commercial use of some irradiated vegetables

International Nuclear Information System (INIS)

Foa, E.

1978-01-01

The use of gamma irradiation as a commercial method for the preservation of fruits and vegetables calls for methods of differentiation between unirradiated and irradiated products. A new approach to studying the influence of gamma irradiation on vegetable tissue at the cellular level by histochemical techniques has been developed by the authors and already applied to a number of fruits and vegetables. The possibility of evidencing radiation effects in the polysaccharide components of the cell wall suggested that these detected differences could be applied to differentiate irradiated from unirradiated tomatoes and potatoes. Some work done to determine changes in the cell wall polysaccharides of gamma-irradiated potatoes and tomatoes and to relate these changes to some other factors, such as storage time and vegetable variety, is reported here. While significant differences have been found in the optical densities of the total polysaccharides of the cell wall as a function of irradiation and of the other variables mentioned, it is not yet possible to use these values as a means of reliable differentiation. (author)

Influence of trichlorfon and fractionated irradiation on hydroproteolytic activity of pancreas and intestinal tissues of rats

Energy Technology Data Exchange (ETDEWEB)

Kocmierska-Grodzka, D [Akademia Medyczna, Bialystok (Poland). Zaklad Farmakologii

1976-03-01

Investigations were carried out of the hydroproteolytic activity of pancreas, small intestine and colon of rats after fractionated irradiation (5x150 R). Marked postirradiation enhancement of lipase activity was found in pancreas and duodenal part of intestine as well as an increase of B-glucuronidase and acid phosphatase activity in nearly all parts of the intestinal tissues. Fractionated irradiation resulted in an increase of pancreatic catheptic (proteolytic) activity, causing simultaneous decrease of proteolytic activity in intestine and colon. Preventive administation of Trichlorfon ten days before irradiation (10 mg or 30 mg/kg) evoked modification of hydroproteolytic activity in intestinal tissues of healthy and irradiated rats. 30mg/kg Trichlorfon exerted antilipolytic and anticatheptic effects in pancreas and intestinal tissues of irradiated rats.

Post-curing conversion kinetics as functions of the irradiation time and increment thickness

Directory of Open Access Journals (Sweden)

Nicola Scotti

2013-04-01

Full Text Available Objective: This study evaluated the variation of conversion degree (DC in the 12 hours following initial photoactivation of a low-shrinkage composite resin (Venus Diamond. Material and Methods: The conversion degree was monitored for 12 hours using Attenuated Total Reflection (ATR F-TIR Spectroscopy. The composite was placed in 1 or 2 mm rings and cured for 10 or 20 seconds with a LED lamp. ATR spectra were acquired from the bottom surface of each sample immediately after the initial photoactivation (P=0, 30 minutes (P=0.5 and 12 hours after photoactivation (P=12 in order to obtain the DC progression during the post-curing period. Interactions between thickness (T, irradiation time (I and post-curing (P on the DC were calculated through ANOVA testing. Results: All the first order interactions were statistically significant, with the exception of the T-P interaction. Furthermore, the shift from P=0 to P=0.5 had a statistically higher influence than the shift from P=0.5 to P=12. The post-curing period played a fundamental role in reaching higher DC values with the low-shrinkage composite resin tested in this study. Moreover, both the irradiation time and the composite thickness strongly influenced the DC. Conclusions: Increased irradiation time may be useful in obtaining a high conversion degree (DC with a low-shrinkage nano-hybrid composite resin, particularly with 2 mm composite layers.

Pathologic characteristics of gut-associated lymphoid tissues and lymphocyte apoptosis in mouse intestine after neutron-and γ-irradiation

International Nuclear Information System (INIS)

Fu Kaifei; Peng Ruiyun; Gao Yabing; Wang Dewen; Chen Haoyu; Wu Xiaohong; Yang Yi; Hu Wenhua; Ma Junjie

2004-01-01

Objective: To compare the pathologic characteristics of gut-associated lymphoid tissues and lymphocyte apoptosis in neutron-irradiated mouse small intestines with those in γ-irradiated ones. Methods: Altogether 350 BALB/c mice were irradiated with different doses of neutrons or γ-rays, and were sacrificed on 6 h,12 h,125 d, 7 d, 14 d, 21 d and 28 d after irradiation and their total intestines were removed. Then the pathologic changes and death mode of lymphocytes in gut-associated lymphoid tissues were studied comparatively with light microscopy, electron microscopy and in situ terminal labeling method. Results: The basic pathologic changes of gut-associated lymphoid tissues after neutron irradiation included degeneration, apoptosis and necrosis of lymphocytes. The number of lymphocytes also decreased. There was no obvious regeneration after 4.0 and 5.5 Gy neutron irradiation, while after 2.5 Gy regeneration and recovery appeared, which were, there fore, dose-dependent. In the 2.5 Gy neutron group, the numbers of lymphocytes of intramucosal and submucous lymphoid tissues decreased, and karyopyknosis and a great quantity of nuclear fragments could also be observed at 6 h-3 d after irradiation. However, on the 3rd day regeneration of crypt epithelial cells appeared. On the 5th day hyperplasia of submucous lymphocytic tissues appeared, but recovery to normal level was not achieved till 14 d after irradiation. The basic pathologic changes after γ-irradiation were similar to that of neutron irradiation. Regeneration and recovery appeared in the 5.5 Gy group while no obvious regeneration in the 12.0 Gy group. The results of in situ terminal labeling indicated that at 6 h after irradiation the number of apoptotic cells in gut-associated lymphoid tissues of each group increased obviously, while in 4.0 Gy neutron group and 12.0 Gy γ-ray group it was more abundant. Conclusion: Both 2.5-5.5 Gy neutron and 5.5-12.0 Gy γ-ray irradiation can induce obvious injuries in gut

Comparisons of Soft Tissue Thickness Measurements in Adult Patients With Various Vertical Patterns

Directory of Open Access Journals (Sweden)

Neslihan Seyhan Cezairli

2017-08-01

Full Text Available Objective: The purposes of this study were to evaluate to study soft tissue facial profile among the different vertical patterns using the Holdaway analysis and the soft tissue thickness measurements. Materials and Methods: The study sample consisted of 90 patients divided into 3 groups: low angle group (30 patients; mean age, 20.38±3.76 years, normal angle group (30 patients; mean age, 19.36±2.83 years and high angle group (30 patients; mean age, 19.44±2.14 years. The study sample, comprised a total of 90 patients (54 women and 36 men divided into low-angle, normal-angle and high angle groups based on vertical growth pattern using the SN/GoGn angle (high-angle group >37°; low-angle group <27°; and control group or normal angle group 27-37°. Facial soft-tissue thickness and Holdaway measurements were analyzed on each radiograph with Image J programme. One-way analysis of variance and post-hoc test (Tukey were used to compare Holdaway measurements and soft tissue thicknesses among the three groups. Results: Significant differences among vertical patterns were observed for the ‘gnathion’, ‘menton’, ‘stomion’ and ‘inferior sulcus to H line’ when both genders were combined. These measurements were thinner in the high-angle group. Significant differences among vertical patterns were observed for ‘gnathion’ and ‘lower lip to H line’ in women; for ‘stomion’ and ‘nose prominence’ in men when examined separately. Conclusion: Facial soft tissue measurements except some for in high angle group were thinner than in low angle group. All soft tissue measurements were greater except for gnathion in low angle group in men than in women.

Reconstruction with vascularized composite tissue in patients with excessive injury following surgery and irradiation

International Nuclear Information System (INIS)

Serafin, D.; DeLand, M.; Lesesne, C.B.; Smith, P.J.; Noell, K.T.; Georgiade, N.

1982-01-01

The biological effects of a single high dose of radiation are examined. Both cellular injury and repair are reviewed during early, intermediate, and late phases. Anticipated composite tissue morbidity is detailed for therapeutic radiation doses administered to the head and neck, breast and thorax, and perineum. Patients who demonstrated excessive time-dose fractionation values were irradiated with lower x-ray energies. Those in whom there was an overlap of treatment fields presented a serious challenge to the reconstructive surgeon. Judicious selection of well-vascularized composite tissue outside the portals of irradiation, preferably with a long vascular pedicle, facilitated reconstruction. When possible, both donor and recipient vasculature should be outside the irradiated area to ensure uninterrupted blood flow to the transferred or transplanted tissue

LYCOPENE EFFICIENCY IN THE MODULATION OF OXIDATIVE DAMAGE IN DIFFERENT TISSUES OF GAMMA IRRADIATED RATS

International Nuclear Information System (INIS)

EL-TAHAWY, N.A.; NADA, A.S.; REZK, R.G.

2008-01-01

Exposure to ionizing radiation induces oxidative stress that has been recognized as an important etiological factor in the causation of several chronic diseases. Lycopene, a carotenoid almost exclusively present in tomatoes and tomatoes products, is a lipid soluble antioxidant claimed to possess cardio protective and anticancer properties. The present study was designed to determine the possible modulator effects of lycopene on radiation-induced oxidative damage to liver, spleen and lung tissues. Animals were supplemented with lycopene (5 mg/kg body weight/ day) by gavages for two weeks before whole body exposure to gamma rays and within the period of irradiation (3 successive doses, each of 3 Gy at 72 hours intervals). Animals were sacrificed on the 3 r d day post the last irradiation session.The results obtained in the present study showed that whole body gamma irradiation produced oxidative stress manifested by significant elevation in lipid peroxides levels measured as thiobarbituric acid reactive substances (TBARS) associated with significant decrease of nitric oxide (NO) content. Non-significant change in total cupper (Cu) in the three tissues was recorded while significant increase of total iron (Fe) was observed in liver and spleen tissues only. Liver tissue of irradiated rats showed significant decrease in the activities of the antioxidant enzymes as superoxide dismutase (SOD) and catalase (CAT). In spleen tissues, there was a significant increase of SOD and significant decrease of CAT activities while in lung tissues, both SOD and CAT activities showed significant increase.Histological observations of photomicrograph of liver sections showed that radiation-induced sever damage obvious by dilated portal vein, ruptured hepatocytes, necrotic, pyknotic, karyolitic nuclei and vacuolated cytoplasm. In spleen tissue, radiation was induced degeneration of lymphatic nodules, dilation follicular artery and marked hemorrhage. In lung tissue, radiation- induces ill

Cell and tissue kinetics of the subependymal layer in mouse brain following heavy charged particle irradiation

Energy Technology Data Exchange (ETDEWEB)

Manley, N.B.; Fabrikant, J.I.; Alpen, E.L.

1988-12-01

The following studies investigate the cellular response and cell population kinetics of the subependymal layer in the mouse brain exposed to heavy charged particle irradiation. Partial brain irradiation with helium and neon ions was confined to one cortex of the brain. Both the irradiated and the unirradiated contralateral cortex showed similar disturbances of the cell and tissue kinetics in the subependymal layers. The irradiated hemisphere exhibited histological damage, whereas the unirradiated side appeared normal histologically. This study concerns the cell population and cell cycle kinetics of the subependymal layer in the mouse brain, and the effects of charged particle irradiations on this cell population. Quantitative high resolution autoradiography was used to study the kinetic parameters in this cell layer. This study should help in understanding the effects of these high-energy heavy ions on normal mammalian brain tissue. The response of the mammalian brain exposure to charged particle ionizing radiation may be extremely variable. It varies from minimal physiological changes to overt tissue necrosis depending on a number of factors such as: the administered dose, dose-rate, the volume of the irradiated tissue, and the biological end-point being examined.

Shear Wave Elastography--A New Quantitative Assessment of Post-Irradiation Neck Fibrosis.

Science.gov (United States)

Liu, K H; Bhatia, K; Chu, W; He, L T; Leung, S F; Ahuja, A T

2015-08-01

Shear wave elastography (SWE) is a new technique which provides quantitative assessment of soft tissue stiffness. The aim of this study was to assess the reliability of SWE stiffness measurements and its usefulness in evaluating post-irradiation neck fibrosis. 50 subjects (25 patients with previous radiotherapy to the neck and 25 sex and age-matched controls) were recruited for comparison of SWE stiffness measurements (Aixplorer, Supersonic Imagine). 30 subjects (16 healthy individuals and 14 post-irradiated patients) were recruited for a reliability study of SWE stiffness measurements. SWE stiffness measurements of the sternocleidomastoid muscle and the overlying subcutaneous tissues of the neck were made. The cross-sectional area and thickness of the sternocleidomastoid muscle and the overlying subcutaneous tissue thickness of the neck were also measured. The post-irradiation duration of the patients was recorded. The intraclass correlation coefficients for the intraoperator and interoperator reliability of deep and subcutaneous tissue SWE stiffness ranged from 0.90-0.99 and 0.77-0.94, respectively. The SWE stiffness measurements (mean +/- SD) of deep and subcutaneous tissues were significantly higher in the post-irradiated patients (64.6 ± 46.8 kPa and 63.9 ± 53.1 kPa, respectively) than the sex and age-matched controls (19.9 ± 7.8 kPa and 15.3 ± 8.37 respectively) (p < 0.001). The SWE stiffness increased with increasing post-irradiation therapy duration in the Kruskal Wallis test (p < 0.001) and correlated with muscle atrophy and subcutaneous tissue thinning (p < 0.01). SWE is a reliable technique and may potentially be an objective and specific tool in quantifying deep and subcutaneous tissue stiffness, which in turn reflects the severity of neck fibrosis. © Georg Thieme Verlag KG Stuttgart · New York.

Post-radiation changes in oral tissues - An analysis of cancer irradiation cases

Directory of Open Access Journals (Sweden)

Jay Ashokkumar Pandya

2014-01-01

Full Text Available Introduction: Radiation, commonly employed as neoadjuvant, primary, and adjuvant therapy for head and neck cancer causes numerous epithelial and stromal changes, prominent among which is fibrosis with its early and late consequences. Very little is known about the true nature of the fibrosed tissue and the type of fibers accumulated. Radiotherapy affects the supporting tumor stroma often resulting in a worsening grade of tumor post-radiation. Aim: To study epithelial, neoplastic, stromal, and glandular changes in oral cavity induced by radiation therapy for oral squamous cell carcinoma (OSCC using special stains. Materials and Methods: The study included 27 samples of recurrent OSCC following completion of radiotherapy (recurrence within an average span of 11 months, and 26 non-irradiated cases of OSCC. Patients with a history of combined radiotherapy and chemotherapy were not included in the study. The epithelial changes assessed included epithelial atrophy, apoptosis, necrosis, dysplasia, and neoplasia. The connective tissue was evaluated for amount of fibrosis, quality of fibers (using picrosirius red staining, fibrinous exudate, necrosis, pattern of invasion, vessel wall thickening, and salivary gland changes. The aforementioned changes were assessed using light and polarizing microscopy and tabulated. Statistical Analysis: Epithelial and connective tissue parameters were compared between the irradiated and non-irradiated cases using chi square and t-tests. Results: Epithelial and connective tissue parameters were found to be increased in irradiated patients. Pattern of invasion by tumor cells varied from strands and  cords between the two groups studied. The effect of radiation was seen to reflect on the maturity of fibers and the regularity of their distribution.

The Influence of Tissue Lyophilization and Gamma Irradiation on the Solubility of Proteins

International Nuclear Information System (INIS)

Komender, J.; Jendyk, J.; Leibschang, J.

1967-01-01

Most recent methods of tissue preservation are based on lyophilization and sterilization with gamma rays. Unfortunately the tissues preserved by this method lose their viability, this being connected with protein denaturation. The denaturing influence either of lyophilization or sterilization with gamma rays on different materials has been described. However, no observations on denaturation of proteins in prepared grafts are known. The work aimed at establishing the influence of individual stages of the procedure used in a tissue bank on the solubility of proteins. An experiment was performed using rat liver as a model tissue. Solubility of protein was determined in five groups of material, as follows: (1) fresh tissue, used as a control, (2) frozen tissue, (3) frozen and lyophilized tissue, (4) frozen, lyophilized and irradiated tissue, and (5) fresh irradiated tissue. Folin's method was used for determination of protein in water extracts of tissues. It was found that: (1) the whole procedure considerably diminished the protein solubility, (2) freezing diminishes the protein solubility by 35% on average, (3) lyophilization causes no further protein denaturation, (4) protein solubility is reduced most (by about 65%) by sterilization with gamma rays. (author)

Does Acellular Dermal Matrix Thickness Affect Complication Rate in Tissue Expander Based Breast Reconstruction?

Directory of Open Access Journals (Sweden)

Jessica F. Rose

2016-01-01

Full Text Available Background. While the benefits of using acellular dermal matrices (ADMs in breast reconstruction are well described, their use has been associated with additional complications. The purpose of this study was to determine if ADM thickness affects complications in breast reconstruction. Methods. A retrospective chart review was performed including all tissue expander based breast reconstructions with AlloDerm (LifeCell, Branchburg, NJ over 4 years. We evaluated preoperative characteristics and assessed postoperative complications including seroma, hematoma, infection, skin necrosis, and need for reintervention. We reviewed ADM thickness and time to Jackson-Pratt (JP drain removal. Results. Fifty-five patients underwent 77 ADM-associated tissue expander based breast reconstructions, with average age of 48.1 years and average BMI of 25.9. Average ADM thickness was 1.21 mm. We found higher complication rates in the thick ADM group. Significant associations were found between smokers and skin necrosis (p<0.0001 and seroma and prolonged JP drainage (p=0.0004; radiated reconstructed breasts were more likely to suffer infections (p=0.0085, and elevated BMI is a significant predictor for increased infection rate (p=0.0037. Conclusion. We found a trend toward increased complication rates with thicker ADMs. In the future, larger prospective studies evaluating thickness may provide more information.

Active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue

International Nuclear Information System (INIS)

Ogawa, Y.; Imanaka, K.; Ashida, C.; Takashima, H.; Imajo, Y.; Kimura, S.

1983-01-01

Active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was studied on the transplanted MM46 tumor of female C3H/He mice after radiotherapy. MM46 tumor cells were inoculated into the right hind paws of mice. On the 5th day, irradiation with the dose irradiated tumor tissue (2000 rad on the fifth day), were injected into the left hind paws of the tumor-bearing mice. Effectiveness of this active specific immunotherapy against tumor was evaluated by the regression of tumor and survival rate of mice. Tumor was markedly regressed and survival rate was significantly increased by the active specific immunitherapy

Biochemical and Tissue Studies on Post Irradiation Recovery in Mammals

International Nuclear Information System (INIS)

Abdou, M.I.M.

2004-01-01

three main studies were performed in this thesis, namely, mortality and survival study, biochemical studies, and studies on tissue alterations cobalt-60 gamma irradiation for low let was used for the external whole body irradiation of the irradiated animal groups. a total number of animals of 722 virgin female adult wister rats of approximately the same age and weight were used for the three studies that were performed, including the control and irradiated animal groups. the animals were housed and kept with special care at fixed temperature, humidity and diet. the study on mortality and survival included 370 animals divided into control and groups irradiated with 4,5,6,7,8 and 9 Gy. this study was followed up for one year to record the number and date of animal deaths for the different irradiated groups. for the 8 and 9 Gy irradiated groups the follow up ended after 12 weeks and 11 days respectively when animal mortality reached 100%. the maximum percent mortality was noted at the second week (3.3,8,14 and 29%) for the 4,5,6 and 7 Gy irradiated groups respectively. for the 8 and 9 Gy irradiated groups, the maximum percent mortality was noted at the first week (42.9 and 90% respectively). regression equations were applied for the percent of mortality of the 5-8 Gy irradiated groups to estimate the LD 50/30, which was found to be 6.4 Gy

Blue light irradiation-induced oxidative stress in vivo via ROS generation in rat gingival tissue.

Science.gov (United States)

Yoshida, Ayaka; Shiotsu-Ogura, Yukako; Wada-Takahashi, Satoko; Takahashi, Shun-suke; Toyama, Toshizo; Yoshino, Fumihiko

2015-10-01

It has been reported that oxidative stress with reactive oxygen species (ROS) generation is induced by blue light irradiation to a living body. Only limited research has been reported in dental field on the dangers of blue light, mostly focusing on cytotoxicity associated with heat injury of dental pulp. We thus performed an in vivo study on oral tissue exposed to blue light. ROS generated upon blue light irradiation of flavin adenine dinucleotide were measured by electron spin resonance spectroscopy. After blue light irradiation, the palatal gingiva of Wistar rats were isolated. Collected samples were subjected to biochemical analysis of lipid peroxidation and glutathione. Singlet oxygen was generated by blue light irradiation, but was significantly quenched in an N-acetyl-L-cysteine (NAC) concentration-dependent manner. Blue light significantly accelerated oxidative stress and increased the oxidized glutathione levels in gingival tissue. These effects were also inhibited by NAC pre-administration. The results suggest that blue light irradiation at clinical levels of tooth bleaching treatment may enhance lipid peroxidation by the induction of oxidative stress and the consumption of a significant amount of intracellular glutathione. In addition, NAC might be an effective supplement for the protection of oral tissues against blue light irradiation-induced oxidative damage. Copyright © 2015 Elsevier B.V. All rights reserved.

Salisphere derived c-Kit+ cell transplantation restores tissue homeostasis in irradiated salivary gland

International Nuclear Information System (INIS)

Nanduri, Lalitha S.Y.; Lombaert, Isabelle M.A.; Zwaag, Marianne van der; Faber, Hette; Brunsting, Jeanette F.; Os, Ronald P. van; Coppes, Robert P.

2013-01-01

Introduction: During radiotherapy salivary glands of head and neck cancer patients are unavoidably co-irradiated, potentially resulting in life-long impairment. Recently we showed that transplantation of salisphere-derived c-Kit expressing cells can functionally regenerate irradiated salivary glands. This study aims to select a more potent subpopulation of c-Kit + cells, co-expressing stem cell markers and to investigate whether long-term tissue homeostasis is restored after stem cell transplantation. Methods and results: Salisphere derived c-Kit + cells that co-expressed CD24 and/or CD49f markers, were intra-glandularly injected into 15 Gy irradiated submandibular glands of mice. Particularly, c-Kit + /CD24 + /CD49f + cell transplanted mice improved saliva production (54.59 ± 11.1%) versus the irradiated control group (21.5 ± 8.7%). Increase in expression of cells with differentiated duct cell markers like, cytokeratins (CK8, 18, 7 and 14) indicated functional recovery of this compartment. Moreover, ductal stem cell marker expression like c-Kit, CD133, CD24 and CD49f reappeared after transplantation indicating long-term functional maintenance potential of the gland. Furthermore, a normalization of vascularization as indicated by CD31 expression and reduction of fibrosis was observed, indicative of normalization of the microenvironment. Conclusions: Our results show that stem cell transplantation not only rescues hypo-salivation, but also restores tissue homeostasis of the irradiated gland, necessary for long-term maintenance of adult tissue

Controlling Fluences of Reactive Species Produced by Multipulse DBDs onto Wet Tissue: Frequency and Liquid Thickness

Science.gov (United States)

Tian, Wei; Kushner, Mark J.

2015-09-01

Tissue covered by a thin liquid layer treated by atmospheric pressure plasmas for biomedical applications ultimately requires a reproducible protocol for human healthcare. The outcomes of wet tissue treatment by dielectric barrier discharges (DBDs) depend on the plasma dose which determines the integral fluences of radicals and ions onto the tissue. These fluences are controlled in part by frequency and liquid thickness. In this paper, we report on results from a computational investigation of multipulse DBDs interacting with wet tissue. The DBDs were simulated for 100 stationary or random streamers at different repetition rates and liquid thicknesses followed by 10 s to 2 min of afterglow. At 100 Hz, NOaq and OHaq are mixed by randomly striking streamers, although they have different rates of solvation. NOaq is nearly completely consumed by reactions with OHaq at the liquid surface. Only H2O2aq, produced through OHaq mutual reactions, survives to reach the tissue. After 100 pulses, the liquid becomes ozone-rich, in which the nitrous ion, NO2-aq, is converted to the nitric ion, NO3-aq. Reducing the pulse frequency to 10 Hz results in significant fluence of NOaq to the tissue as NOaq can escape during the interpulse period from the liquid surface where OHaq is formed. For the same reason, NO2-aq can also reach deeper into the liquid at lower frequency. Frequency and thickness of the liquid are methods to control the plasma produced aqueous species to the underlying tissue. Work supported by DOE (DE-SC0001319) and NSF (CHE-1124724).

Pattern of Bone Generation after Irradiation in Vascularized Tissue Engineered Constructs.

Science.gov (United States)

Eweida, Ahmad; Fathi, Ibrahim; Eltawila, Ahmed M; Elsherif, Ahmad M; Elkerm, Yasser; Harhaus, Leila; Kneser, Ulrich; Sakr, Mahmoud F

2018-02-01

 Regenerative medicine modalities provide promising alternatives to conventional reconstruction techniques but are still deficient after malignant tumor excision or irradiation due to defective vascularization.  We investigated the pattern of bone formation in axially vascularized tissue engineering constructs (AVTECs) after irradiation in a study that mimics the clinical scenario after head and neck cancer. Heterotopic bone generation was induced in a subcutaneously implanted AVTEC in the thigh of six male New Zealand rabbits. The tissue construct was made up of Nanobone (Artoss GmbH; Rostock, Germany) granules mixed with autogenous bone marrow and 80 μL of bone morphogenic protein-2 at a concentration of 1.5 μg/μL. An arteriovenous loop was created microsurgically between the saphenous vessels and implanted in the core of the construct to induce axial vascularization. The constructs were subjected to external beam irradiation on postoperative day 20 with a single dose of 15 Gy. The constructs were removed 20 days after irradiation and subjected to histological and immunohistochemical analysis for vascularization, bone formation, apoptosis, and cellular proliferation.  The vascularized constructs showed homogenous vascularization and bone formation both in their central and peripheral regions. Although vascularity, proliferation, and apoptosis were similar between central and peripheral regions of the constructs, significantly more bone was formed in the central regions of the constructs.  The study shows for the first time the pattern of bone formation in AVTECs after irradiation using doses comparable to those applied after head and neck cancer. Axial vascularization probably enhances the osteoinductive properties in the central regions of AVTECs after irradiation. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Comparison of the effect between an active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue and that using irradiated tumor cells

International Nuclear Information System (INIS)

Ogawa, Yasuhiro; Maeda, Tomoho; Yoshida, Shoji; Yamamoto, Yoichi; Morita, Masaru

1983-01-01

The effect of the active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was compared with that of irradiated (10,000 rads) tumor cells on the transplanted MM46 tumor of female C3H/He mice after radiotherapy. MM46 tumor cells were inoculated into the right hind paws of mice. On the 6th day, irradiation with a dose of 3,000 rads was performed. On the 14th day, tumor cells and concomitant mononuclear cells which were separated from the low-dose irradiated tumor tissue (2,000 rads on the 6th day) were injected into the left hind paws of one group of the tumor-bearing mice. On the same day, irradiated MM46 tumor cells were injected into the left hind paws of another group of the tumor-bearing mice. Effectiveness of these two methods of active specific immunotherapy against tumor was evaluated by the regression of tumor and survival rate of mice. The active specific immunotherapy using the immune reaction of a low-dose irradiated tumor tissue was far more effective than irradiated tumor cells on this tumor system involved. (author)

The effect of irradiation on function in self-renewing normal tissues with differing proliferative organisation

International Nuclear Information System (INIS)

Wheldon, T.E.; Michalowski, A.S.

1982-01-01

The primary effect of irradiation on self-renewing normal tissues is sterilisation of their proliferative cells, but how this translates into failure of tissue function depends on the mode of organisation of the tissue concerned. It has recently been suggested (Michalowski, 1981) that proliferative normal tissues may be classed as ''hierarchical'' (like haemopoietic tissues) or as ''flexible'' (like liver parenchyma) and that radiation injury to tissue function develops by different pathways in these tissues. Mathematical model studies confirm the different radiation responses of differently organized tissues. Tissues of the ''flexible'' or ''F-type'' category display a variety of novel radiobiological properties, different from those of the more familiar ''hierarchical'' or ''H-type'' tissues. The ''F-type'' responses are strongly influenced by radiation-sterilised (''doomed'') cells, and is is suggested that the role of ''doomed'' cells has been undervalued relative to that of clonogenic survivors. Since ''F-type'' tissues have characteristically low rates of cell renewal, it is possible that these tissues are preferentially responsible for late effects of irradiation in clinical radiotherapy. (author)

Effect of propolis feeding on rat tissues damaged by X-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Lee, Ji Hoon; Seo, Eul Won [Andong National Univ., Andong (Korea, Republic of); Ji, Tae Jeong [Kaya Univ., Goryeong (Korea, Republic of)

2007-06-15

Present study aimed to investigate the radioprotective effects of propolis feeding on rat tissues damaged by X-ray irradiation. It was shown that the number of white blood cell in X-ray irradiated group supplemented with propolis increased as much to those of the control group and also the GOT activities among the blood components were decreased after propolis feeding. The mineral contents such as Mg, Fe, Ca, Mn, Cu, Mo, Ni, As in liver were increased as compared with those of the control group but maintained lower level than those of only irradiated groups, implying that the propolis feeding elevated the recovery capability of white blood cell effectively and propolis have a potential resistance to cell damage by X-ray. According to histological observations of the testis, intestine and liver tissues which are irradiated after feeding propolis, the numbers of damaged undifferentiated cells were decreased in testis and the shape of the goblet cells and inner and outer muscular layers in intestine were restored to the original state and the hepatocytes and interlobular veins were shown intact in liver, suggesting that propolis has a potential capacity to restore cell shapes or resist deformation of cell.

Lipid metabolism in rat tissues exposed to the chronic effects of γ-irradiation and ubiquinone Q9

International Nuclear Information System (INIS)

Novoselova, E.G.

1992-01-01

Chronic γ-irradiation of rats with the daily dose of 0.129 Gy activates the synthesis of various classes of lipids in the thymus, spleen and bone marrow cells and induces lipid accumulation in these tissues. Feeding of rats with the antioxidant, ubiquinone Q-9, under conditions of chronic irradiation causes a considerable normalization of lipogenesis and levels of the lipid concentration in the tissues of animals irradiated with the dose of 20 Gy

Multi-time-scale heat transfer modeling of turbid tissues exposed to short-pulsed irradiations.

Science.gov (United States)

Kim, Kyunghan; Guo, Zhixiong

2007-05-01

A combined hyperbolic radiation and conduction heat transfer model is developed to simulate multi-time-scale heat transfer in turbid tissues exposed to short-pulsed irradiations. An initial temperature response of a tissue to an ultrashort pulse irradiation is analyzed by the volume-average method in combination with the transient discrete ordinates method for modeling the ultrafast radiation heat transfer. This response is found to reach pseudo steady state within 1 ns for the considered tissues. The single pulse result is then utilized to obtain the temperature response to pulse train irradiation at the microsecond/millisecond time scales. After that, the temperature field is predicted by the hyperbolic heat conduction model which is solved by the MacCormack's scheme with error terms correction. Finally, the hyperbolic conduction is compared with the traditional parabolic heat diffusion model. It is found that the maximum local temperatures are larger in the hyperbolic prediction than the parabolic prediction. In the modeled dermis tissue, a 7% non-dimensional temperature increase is found. After about 10 thermal relaxation times, thermal waves fade away and the predictions between the hyperbolic and parabolic models are consistent.

Effect of tumor therapeutic irradiation on the mechanical properties of teeth tissue

International Nuclear Information System (INIS)

Fraenzel, W.; Gerlach, R.; Hein, H.J.; Schaller, H.G.

2006-01-01

Tumor irradiation of the head-neck area is accompanied by the development of a so-called radiation caries in the treated patients. In spite of conservative therapeutic measures, the process results in tooth destruction. The present study investigated the effects of irradiation on the demineralization and remineralization of the dental tissue. For this purpose, retained third molars were prepared and assigned either to a test group, which was exposed to fractional irradiation up to 60 Gy, or to a non-irradiated control group. Irradiated and non-irradiated teeth were then demineralized using acidic hydroxyl-cellulose gel; afterwards the teeth were remineralized using either Bifluorid12 registered or elmex gelee registered . The nanoindentation technique was used to measure the mechanical properties, hardness and elasticity, of the teeth in each of the conditions. The values were compared to the non-irradiated control group. Irradiation decreased dramatically the mechanical parameters of enamel and dentine. In non-irradiated teeth, demineralization had nearly the same effects of irradiation on the mechanical properties. In irradiated teeth, the effects of demineralization were negligible in comparison to non-irradiated teeth. Remineralization with Bifluorid12 registered or elmex gelee registered led to a partial improvement of the mechanical properties of the teeth. The enamel was more positively affected, by remineralization than the dentine. (orig.)

Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

Energy Technology Data Exchange (ETDEWEB)

Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, Kwangwon [Eulji Univ. Hospital, Daejeon (Korea, Republic of); Kwon, Jungkee [Chonbuk National Univ., Jeonju (Korea, Republic of); Kim, Taewoon [Jeonbuk Technopark, Jeonju (Korea, Republic of)

2012-03-15

This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage.

Prevention Effect of Poly-Gamma-Glutamic Acid on Tissue Damage Induced by Gamma Irradiation as a Natural Cross-Linker

International Nuclear Information System (INIS)

Kim, Jaehun; Sung, Nakyun; Kim, Jeongsoo; Jo, Euri; Choi, Jongil; Park, Jongheum; Lee, Juwoon; Lee, Kwangwon; Kwon, Jungkee; Kim, Taewoon

2012-01-01

This study was to determine the prevention effect of poly-gamma-glutamic acid (PGA) on tissue damage induced by gamma irradiation for development of xenograft. PGA (MW 2000 kDa) extracted from permeated soy bean (natto) was used in this study as natural compound, and glutaraldehyde (GA) and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) were used as a control, chemical based cross-linking agents. GA, EDC and PGA treated porcine tendons were gamma-irradiated at the dose of 30 kGy. Prevention effects against tissue damage were measured as the result of tensile strength, hydroxyproline contents and tissue morphological analysis. Tensile of porcine tendon was remarkably decreased by gamma irradiation, but increased in PGA treated group. Morphological analysis showed that collagen structure was broken by gamma irradiation, but attenuated by PGA treatment. Base on the results, it demonstrated that gamma irradiation can induce severe alteration of porcine tendon, but PGA can effectively improve the tissue damage

Microradiographical aspects of maxillo-dental lesions in the irradiated cat

International Nuclear Information System (INIS)

Dambrain, R.; Dhem, A.; Winant, M.; Wambersie, A.

1986-01-01

This paper describes the reactions of bone tissue and teeth, in cats, after continuous low rate irradiation, in conditions similar to those encountered in interstitial therapy. Irradiations were performed using 3 hairpin shape iridium-192 wires. The doses were assessed following the Paris System. As far as the teeth are concerned, the development proceeds normally after 60 Gy irradiation delivered over 6 days. At 80 Gy, irradiation has an indirect effect on the teeth by altering the salivary environment; the dental crowns are coated with a thick layer of tarter and show cavities reaching the pulp. As far as the bony tissue is concerned, its normal development is not altered after 60 Gy. At 80 Gy, a destructive process appears, similar to those oberved in patients with mandibular osteoradionecrosis. The foci of destruction are very irregular in shape; the cavities do not contain osteoclasts but small mononucleated cells

Global adiposity and thickness of intraperitoneal and mesenteric adipose tissue depots are increased in women with polycystic ovary syndrome (PCOS).

Science.gov (United States)

Borruel, Susana; Fernández-Durán, Elena; Alpañés, Macarena; Martí, David; Alvarez-Blasco, Francisco; Luque-Ramírez, Manuel; Escobar-Morreale, Héctor F

2013-03-01

Sexual dimorphism suggests a role for androgens in body fat distribution. Women with polycystic ovary syndrome (PCOS), a mainly androgen excess disorder, often present with abdominal obesity and visceral adiposity. We hypothesized that women with PCOS have a masculinized body fat distribution favoring the deposition of fat in visceral and organ-specific adipose tissue depots. This was a case-control study. The study was conducted at an academic hospital. Women with PCOS (n = 55), women without androgen excess (n = 25), and men (n = 26) presenting with similar body mass index participated in the study. There were no interventions. Ultrasound measurements of adipose tissue depots including sc (minimum and maximum), preperitoneal, ip, mesenteric, epicardial, and perirenal fat thickness were obtained and total body fat mass was estimated using a body fat monitor. Men and patients with PCOS had increased amounts of total body fat compared with control women. Men had increased thickness of intraabdominal adipose tissue depots compared with the control women, with the women with PCOS showing intermediate values that were also higher than those of control women in the case of ip and mesenteric fat thickness and was close to reaching statistical significance in the case of epicardial fat thickness. Women with PCOS also showed increased minimum sc fat thickness compared with the control women. Obesity increased the thickness of all of the adipose tissue depots in the 3 groups of subjects. Women with PCOS have higher global adiposity and increased amounts of visceral adipose tissue compared with control women, especially in the ip and mesenteric depots.

Function of skeletal muscle tissue formed after myoblast transplantation into irradiated mouse muscles.

Science.gov (United States)

Wernig, A; Zweyer, M; Irintchev, A

2000-01-15

1. Pretreatment of muscles with ionising radiation enhances tissue formation by transplanted myoblasts but little is known about the effects on muscle function. We implanted myoblasts from an expanded, male-donor-derived, culture (i28) into X-ray irradiated (16 Gy) or irradiated and damaged soleus muscles of female syngeneic mice (Balb/c). Three to 6 months later the isometric contractile properties of the muscles were studied in vitro, and donor nuclei were visualised in muscle sections with a Y chromosome-specific DNA probe. 2. Irradiated sham-injected muscles had smaller masses than untreated solei and produced less twitch and tetanic force (all by about 18 %). Injection of 106 myoblasts abolished these deficiencies and innervation appeared normal. 3. Cryodamage of irradiated solei produced muscle remnants with few (1-50) or no fibres. Additional myoblast implantation led to formation of large muscles (25 % above normal) containing numerous small-diameter fibres. Upon direct electrical stimulation, these muscles produced considerable twitch (53 % of normal) and tetanic forces (35 % of normal) but innervation was insufficient as indicated by weak nerve-evoked contractions and elevated ACh sensitivity. 4. In control experiments on irradiated muscles, reinnervation was found to be less complete after botulinum toxin paralysis than after nerve crush indicating that proliferative arrest of irradiated Schwann cells may account for the observed innervation deficits. 5. Irradiation appears to be an effective pretreatment for improving myoblast transplantation. The injected cells can even produce organised contractile tissue replacing whole muscle. However, impaired nerve regeneration limits the functional performance of the new muscle.

Effect of tumor therapeutic irradiation on the mechanical properties of teeth tissue

Energy Technology Data Exchange (ETDEWEB)

Fraenzel, W. [Dept. of Physics, Martin Luther Univ. Halle (Germany); Gerlach, R. [Univ. Clinic and Policlinic for Radiation Therapy, Martin Luther Univ. Halle (Germany); Hein, H.J. [Univ. Clinic and Policlinic for Orthopaedics and Physical Medicine, Martin Luther Univ. Halle (Germany); Schaller, H.G. [Dept. of Operative Dentistry and Periodontology, Martin Luther Univ. Halle (Germany)

2006-07-01

Tumor irradiation of the head-neck area is accompanied by the development of a so-called radiation caries in the treated patients. In spite of conservative therapeutic measures, the process results in tooth destruction. The present study investigated the effects of irradiation on the demineralization and remineralization of the dental tissue. For this purpose, retained third molars were prepared and assigned either to a test group, which was exposed to fractional irradiation up to 60 Gy, or to a non-irradiated control group. Irradiated and non-irradiated teeth were then demineralized using acidic hydroxyl-cellulose gel; afterwards the teeth were remineralized using either Bifluorid12 {sup registered} or elmex gelee {sup registered}. The nanoindentation technique was used to measure the mechanical properties, hardness and elasticity, of the teeth in each of the conditions. The values were compared to the non-irradiated control group. Irradiation decreased dramatically the mechanical parameters of enamel and dentine. In non-irradiated teeth, demineralization had nearly the same effects of irradiation on the mechanical properties. In irradiated teeth, the effects of demineralization were negligible in comparison to non-irradiated teeth. Remineralization with Bifluorid12 {sup registered} or elmex gelee {sup registered} led to a partial improvement of the mechanical properties of the teeth. The enamel was more positively affected, by remineralization than the dentine. (orig.)

The use of tissue culture techniques to detect irradiated vegetables

International Nuclear Information System (INIS)

Al-Safadi, B.; Sharabi, N.E.; Nabulsi, I

2001-01-01

the ability of two tissue culture methods, callus and vegetable growth induction, to detect irradiated vegetables was evaluated. Potato tubers, carrot roots, garlic cloves and onion bulbs were subjected to various gamma radiation doses (0, 25, 100, 150, 250, 500, 750, and 1000 Gy). Irradiated vegetables were cultured in vitro and in vivo (pots). Gamma irradiation significantly reduced callus-forming ability especially in carrot and potato where no callus was observed in doses higher than 50 Gy. Length of shoots and roots growing from irradiated garlic and onion explants was considerably reduced starting from the 25 Gy dose. No roots were formed on garlic explants at any irradiation dose. Garlic leaves growing from irradiated explants were spotted with purple to brown spots. The intensity of these spots increased as gamma ray dosage increased. In the pot experiment, potato plant appeared in the control only. On the contrary, a complete sprouting of garlic and onion was seen in all irradiation treatments. It was not possible to distinguish between the various irradiation treatments and the control 3 days after planting in pots. The two in vitro techniques, tested in our study, may effectively be used to detect irradiated vegetables and estimate the range of doses used. The callus formation method is more useful for potato and carrot, since regeneration of shoots in vitro from these two plants takes along time, making this method unpractical. The other technique is very useful in the case of onion and garlic since it is rapid. The two techniques can be used with most of the vegetables that can be cultured in vitro. (Author)

Characterization of 150 $\\mu$m thick epitaxial silicon detectors from different producers after proton irradiation

CERN Document Server

Hoedlmoser, H; Haerkoenen, J; Kronberger, M; Trummer, J; Rodeghiero, P

2007-01-01

Epitaxial (EPI) silicon has recently been investigated for the development of radiation tolerant detectors for future high-luminosity HEP experiments. A study of 150 mm thick EPI silicon diodes irradiated with 24GeV=c protons up to a fluence of 3 1015 p=cm2 has been performed by means of Charge Collection Efficiency (CCE) measurements, investigations with the Transient Current Technique (TCT) and standard CV=IV characterizations. The aim of the work was to investigate the impact of radiation damage as well as the influence of the wafer processing on the material performance by comparing diodes from different manufacturers. The changes of CCE, full depletion voltage and leakage current as a function of fluence are reported. While the generation of leakage current due to irradiation is similar in all investigated series of detectors, a difference in the effective doping concentration can be observed after irradiation. In the CCE measurements an anomalous drop in performance was found even for diodes exposed to ...

Hip fracture and anthropometric variations: dominance among trochanteric soft tissue thickness, body height and body weight during sideways fall.

Science.gov (United States)

Majumder, Santanu; Roychowdhury, Amit; Pal, Subrata

2013-01-01

Hip fracture depends on various anthropometric parameters such as trochanteric soft tissue thickness, body height and body weight. The objective was to evaluate the responses to the variations in anthropometric parameters during sideways fall, and to identify the most dominant parameter among them. Seven finite element models were developed having anthropometric variations in trochanteric soft tissue thickness (5-26 mm), body height (1.70-1.88 m), and body weight (63-93.37 kg). These were simulated for sideways fall with ANSYS-LS-DYNA® code. Significant effect of trochanteric soft tissue thickness variation was found on 'normalized peak impact force with respect to the body weight' (p=0.004, r²=0.808) and strain ratio (p=0.083, r²=0.829). But, variation in body height was found to be less significant on normalized peak impact force (p=0.478, r²=0.105) and strain ratio (p=0.292, r²=0.217). Same was true for the variation in body weight on normalized peak impact force (p=0.075, r²=0.456) and strain ratio (p=0.857, r²=0.007). The risk factor for fracture was also well correlated to the strain ratio for the inter-trochanteric zone (pfractures are clinically observed to happen. Trochanteric soft tissue thickness was found likely to be the most dominant parameter over body height and body weight, signifying that a slimmer elderly person, taller or shorter, with less trochanteric soft tissue thickness should be advised to take preventive measures against hip fracture under sideways fall. © 2013.

Effects of x-ray irradiation on mast cells and mastocalcergy in the connective tissue

Energy Technology Data Exchange (ETDEWEB)

Song, H. Y.; Rhee, S. J.; Son, M. H.; Choi, K. C. [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

1982-09-15

Experiments were performed to observe the influence of x-ray irradiation on mast cells and mastocalcergy in rats. Animals were irradiated single dose of x-ray. X-ray irradiation was applied to the whole body in doses either 100 rads or 150 rads (Cobalt-60 Teletherapy Unit). One day after irradiation the rats were injected lead acetate intravenously, followed by injection of compound 48/80 in the back subcutaneously. Animals were killed by decapitation at intervals, 1 hour, 5 hours, 1 day and 6 day after subcutaneous injection. Specimens of the abdominal and back skin were fixed in alcohol formol solution and stained with the following methods; H-E for observation of pathological changes of tissues, toluidine blue for demonstration of mast cells, von Kossa-azure A for demonstration of carbonate and phosphate, and chloranilic acid for demonstration of calcium. The following conclusions were obtained. Calciphylatic wheals are large size in the control group, medium size in 100 rads irradiation group and small size in 150 rads irradiation group. In x-ray irradiation groups the number of mast cells decreases more in the 150 rads than in the 100 rads irradiation. In the 100 rads x-ray irradiation group, histochemical study of the injection sites showed that calcium impregnated to mast cell granules and connective tissue fibers in 1 days after subcutaneous injection. The morphogenesis of this calcinosis was the same in the rat of 5 hour after subcutaneous injection of the control group. Whereas, 1 day after subcutaneous injection in 150 rads x-ray irradiation group calcium deposited more slightly than other groups.

A magnetic resonance imaging study on changes in rat mandibular bone marrow and pulp tissue after high-dose irradiation

Energy Technology Data Exchange (ETDEWEB)

Lee, Wan; Lee, Byung Do [Dept. of Oral and Maxillofacial Radiology and Wonkwang Dental Research Institute, College of Dentistry, Wonkwang University, Iksan (Korea, Republic of); Lee, Kang Kyoo [Dept. of Radiation Oncology, School of Medicine, Wonkwang University, Iksan (Korea, Republic of); Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology, School of Dentistry and Institute of Oral Bioscience, Chonbuk National University, Jeonju (Korea, Republic of)

2014-03-15

This study was designed to evaluate whether magnetic resonance imaging (MRI) is appropriate for detecting early changes in the mandibular bone marrow and pulp tissue of rats after high-dose irradiation. The right mandibles of Sprague-Dawley rats were irradiated with 10 Gy (Group 1, n=5) and 20 Gy (Group 2, n=5). Five non-irradiated animals were used as controls. The MR images of rat mandibles were obtained before irradiation and once a week until week 4 after irradiation. From the MR images, the signal intensity (SI) of the mandibular bone marrow and pulp tissue of the incisor was interpreted. The MR images were compared with the histopathologic findings. The SI of the mandibular bone marrow had decreased on T2-weighted MR images. There was little difference between Groups 1 and 2. The SI of the irradiated groups appeared to be lower than that of the control group. The histopathologic findings showed that the trabecular bone in the irradiated group had increased. The SI of the irradiated pulp tissue had decreased on T2-weighted MR images. However, the SI of the MR images in Group 2 was high in the atrophic pulp of the incisor apex at week 2 after irradiation. These patterns seen on MRI in rat bone marrow and pulp tissue were consistent with histopathologic findings. They may be useful to assess radiogenic sclerotic changes in rat mandibular bone marrow.

DNA Measurement of Overlapping Cell Nuclei in Thick Tissue Sections

Directory of Open Access Journals (Sweden)

Liang Ji

1997-01-01

Full Text Available The paper describes an improved image analysis procedure for measuring the DNA content of cell nuclei in thick sections of liver tissue by absorption densitometry. Whereas previous methods only permitted the analysis of isolated nuclei, the new technique enables both isolated and overlapping nuclei to be measured. A 3D segmentation procedure determines whether each object is an isolated nucleus or a pair of overlapping nuclei; in the latter case the combined optical density is redistributed to the individual nuclei. A selection procedure ensures that only complete nuclei are measured.

Synchrotron X-ray irradiation effects on the device characteristics and the resistance to hot-carrier damage of MOSFETs with 4 nm thick gate oxides

International Nuclear Information System (INIS)

Tanaka, Yuusuke; Tanabe, Akira; Suzuki, Katsumi

1998-01-01

The effects of synchrotron x-ray irradiation on the device characteristics and hot-carrier resistance of n- and p-channel metal oxide semiconductor field effect transistors (MOSFETs) with 4 nm thick gate oxides are investigated. In p-channel MOSFETs, device characteristics were significantly affected by the x-ray irradiation but completely recovered after annealing, while the device characteristics in n-channel MOSFETs were not noticeably affected by the irradiation. This difference appears to be due to a difference in interface-state generation. In p-channel MOSFETs, defects caused by boron-ion penetration through the gate oxides may be sensitive to x-ray irradiation, causing the generation of many interface states. These interface states are completely eliminated after annealing in hydrogen gas. The effects of irradiation on the resistance to hot-carrier degradation in annealed 4 nm thick gate-oxide MOSFETs were negligible even at an x-ray dose of 6,000 mJ/cm 2

Upconverting core-shell nanocrystals with high quantum yield under low irradiance: On the role of isotropic and thick shells

Energy Technology Data Exchange (ETDEWEB)

Fischer, Stefan; Goldschmidt, Jan Christoph [Fraunhofer Institute for Solar Energy Systems, Heidenhofstraße 2, 79110 Freiburg (Germany); Johnson, Noah J. J.; Pichaandi, Jothirmayanantham; Veggel, Frank C. J. M. van [Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, British Columbia V8W 3V6 (Canada)

2015-11-21

Colloidal upconverter nanocrystals (UCNCs) that convert near-infrared photons to higher energies are promising for applications ranging from life sciences to solar energy harvesting. However, practical applications of UCNCs are hindered by their low upconversion quantum yield (UCQY) and the high irradiances necessary to produce relevant upconversion luminescence. Achieving high UCQY under practically relevant irradiance remains a major challenge. The UCQY is severely limited due to non-radiative surface quenching processes. We present a rate equation model for migration of the excitation energy to show that surface quenching does not only affect the lanthanide ions directly at the surface but also many other lanthanide ions quite far away from the surface. The average migration path length is on the order of several nanometers and depends on the doping as well as the irradiance of the excitation. Using Er{sup 3+}-doped β-NaYF{sub 4} UCNCs, we show that very isotropic and thick (∼10 nm) β-NaLuF{sub 4} inert shells dramatically reduce the surface-related quenching processes, resulting in much brighter upconversion luminescence at simultaneously considerably lower irradiances. For these UCNCs embedded in poly(methyl methacrylate), we determined an internal UCQY of 2.0% ± 0.2% using an irradiance of only 0.43 ± 0.03 W/cm{sup 2} at 1523 nm. Normalized to the irradiance, this UCQY is 120× higher than the highest values of comparable nanomaterials in the literature. Our findings demonstrate the important role of isotropic and thick shells in achieving high UCQY at low irradiances from UCNCs. Additionally, we measured the additional short-circuit current due to upconversion in silicon solar cell devices as a proof of concept and to support our findings determined using optical measurements.

Radiation-induced organogenesis: effects of irradiated medium and its components on tobacco tissue culture

International Nuclear Information System (INIS)

Degani, N.

1975-01-01

Gamma irradiated medium induces the formation of buds in non-irradiated dark growth tobacco callus (Nicotiana tabacum Var. Wisconsin No.38). Experiments were conducted to determine the component(s) of the medium that is effective in this radiation-induced organogenesis. Fraction of medium were irradiated singly and in combination, then combined with non-irradiated fractions to form the complete growth medium. The results showed that irradiated indoleacetic acid (IAA) was not the effective component in the induction of organogensis. Omission of IAA from the medium resulted in the formation of buds, as expected. Irradiated myo-inositol induced organogenesis more consistently than the other irradiated components. The age of the inoculum tissue and its passage number from the tobacco stem affected the potency of the tobacco callus to organise. (author)

Iso-effect tables for tolerance of irradiated normal human tissues

International Nuclear Information System (INIS)

Cohen, L.; Creditor, M.

1983-01-01

Available literature on a radiation injury to human tissues (lung, brain, kidney and intestine) was surveyed. A parameter search program (RAD3) was used to derive best-fitting cell kinetic parameters, on the assumption that radiation injury arises from depletion of parenchymal cells in the irradiated organs. From these parameters iso-effect tables were constructed for a wide range of treatment schedules, including daily treatment as well as fractionation at longer intervals, for each tissue. The tables provide a set of limiting doses, above which the risk of radiation injury becomes substantial. Tolerance limits and dose-time-factors were substantially different in the four tissues. It is concluded that computed iso-effect tables provide a more reliable guide to treatment than conventional time-dose equations

Outcomes of microvascular free tissue transfer in twice-irradiated patients.

Science.gov (United States)

Clancy, Kate; Melki, Sami; Awan, Musaddiq; Li, Shawn; Lavertu, Pierre; Fowler, Nicole; Yao, Min; Rezaee, Rod; Zender, Chad A

2017-09-01

Patients may require microvascular free tissue transfer (MFTT) following re-irradiation for recurrent cancer or radiation complications. The objective of this study was to describe the indications for and outcomes of free flaps performed in twice-radiated patients. A retrospective chart review identified the indications for and outcomes of 36 free flaps performed on 29 twice-irradiated patients. The free flap success rate was 92%. The most common indications requiring MFTT were cancer recurrence and osteoradionecrosis. Sixty-one percent experienced postoperative complications, most commonly wound infection (33%). Twenty-five percent of the procedures required return to the operating room due to postoperative complication. MFTT can be successfully performed in the twice-irradiated patient population with a success rate comparable to singly-radiated patients. Despite a high success rate, there is also a high rate of surgical site complications, especially infection. © 2017 Wiley Periodicals, Inc.

Changes in rat liver and adipose tissue lipogenesis after single lethal X-irradiation: modification by the restricted food intake

International Nuclear Information System (INIS)

Sedlakova, A.; Ahlers, I.; Praslicka, M.

1981-01-01

Male rats of Wistar strain were adapted during a 4-week period to the nutritional regimes of meal feeding (MF) and ad libitum (AL) and were irradiated with the single whole-body lethal X-ray dose 14.35 Gy after 22 h of fasting. Within the intervals 1, 24, 48 and 72 h after irradiation lipogenesis changes in the liver were studied by measuring 1- 14 C-acetate incorporation (74 KBq) in the total lipids, fatty acids and cholesterol, and in the white adipose tissue pieces by measuring U- 14 C-glucose incorporation (74 KBq) in the total lipids, fatty acids and glyceride glycerol. Lipogenesis increased in the liver of the irradiated rats as compared with sham irradiated rats and reached the maximal values at 72 h after irradiation in AL animals and at 48 h after irradiation in MF animals. Lipogenesis in the adipose tissue decreased in the irradiated rats as compared with the sham irradiated ones and continued to decrease with the post-irradiation period. The adaptation to the nutritional regime of meal feeding markedly modified lipogenesis in the liver and the adipose tissue of the irradiated rats. Long-term fasting (before and after irradiation) was supposed to be another modifying factor in the lipogenesis changes. Lipogenesis changes in the liver depended on the MF nutritional regime. (author)

Changes in rat liver and adipose tissue lipogenesis after single lethal X-irradiation: modification by the restricted food intake

Energy Technology Data Exchange (ETDEWEB)

Sedlakova, A; Ahlers, I; Praslicka, M [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

1981-01-01

Male rats of Wistar strain were adapted during a 4-week period to the nutritional regimes of meal feeding (MF) and ad libitum (AL) and were irradiated with the single whole-body lethal X-ray dose 14.35 Gy after 22 h of fasting. Within the intervals 1, 24, 48 and 72 h after irradiation lipogenesis changes in the liver were studied by measuring 1-/sup 14/C-acetate incorporation (74 KBq) in the total lipids, fatty acids and cholesterol, and in the white adipose tissue pieces by measuring U-/sup 14/C-glucose incorporation (74 KBq) in the total lipids, fatty acids and glyceride glycerol. Lipogenesis increased in the liver of the irradiated rats as compared with sham irradiated rats and reached the maximal values at 72 h after irradiation in AL animals and at 48 h after irradiation in MF animals. Lipogenesis in the adipose tissue decreased in the irradiated rats as compared with the sham irradiated ones and continued to decrease with the post-irradiation period. The adaptation to the nutritional regime of meal feeding markedly modified lipogenesis in the liver and the adipose tissue of the irradiated rats. Long-term fasting (before and after irradiation) was supposed to be another modifying factor in the lipogenesis changes. Lipogenesis changes in the liver depended on the MF nutritional regime.

A mast cell secretagogue, compound 48/80, prevents the accumulation of hyaluronan in lung tissue injured by ionizing irradiation

International Nuclear Information System (INIS)

Nilsson, K.; Bjermer, L.; Hellstroem, S.H.; Henriksson, R.; Haellgren, R.

1990-01-01

Irradiation with a single dose of 30 Grey on the basal regions of the lungs of Sprague-Dawley rats induced a peribronchial and alveolar inflammation. Infiltration of mast cells in the edematous alveolar interstitial tissue and also in the peribronchial tissue were characteristic features of the lesion. The appearance of mast cells was already seen 4 wk after irradiation and by weeks 6 to 8 there was a heavy infiltration. The staining properties suggested that they were connective tissue-type mast cells. The infiltration of mast cells was paralleled by an accumulation of hyaluronan (hyaluronic acid) in the alveolar interstitial tissue 6 and 8 wk after irradiation. The recovery of hyaluronan (HA) during bronchoalveolar lavage (BAL) of the lungs also increased at this time. Treatment with a mast cell secretagogue, compound 48/80, induced a distinct reduction of granulated mast cells in the alveolar tissue. Regular treatment with compound 48/80 from the time of irradiation considerably reduced the HA recovery during BAL and the HA accumulation in the interstitial tissue but did not affect the interstitial infiltration of mononuclear cells and polymorphonuclear leukocytes. By contrast, an accumulation of HA in the alveolar interstitial space was induced when compound 48/80 was given not until mast cell infiltration of the lung had started. The effects of compound 48/80 indicate that the connective tissue response after lung irradiation is dependent on whether or not mast cell degranulation is induced before or after the mast cell infiltration of the alveolar tissue

Fusarium growth on culture media made of tissue juice from irradiated and unirradiated potato tubers

International Nuclear Information System (INIS)

Taczanowski, M.

1994-01-01

Fusarium Sulphureum Schlecht is one of the tuber pathogens causing potato storage disease knowing as dry rot. Because irradiation can disturb the tissue defence mechanism against the pathogen, it was decided to carry out experiments on influence of the treatment on subsequent tuber tissue reaction to a maceration process. The maceration as a physical stress was a substitute for the pathogen activity. Tubers of two potato varieties were tested: Mila -a resistant variety to Fusarium and Atol - susceptible one. Tubers of both varieties were irradiated with a dose of 105 kGy. Unirradiated tubers were taken as a control. A day after irradiation the cortex tissue was macerated using an ordinary rasper and the resulted tissue pulp was strained through medical gauze to obtain crude juice. The juice was clarified by centrifugation and then added to dissolved PDA. The volume ratio of juice to PDA was 1:1. The prepared media were dispensed into Petri dishes. Small pieces of the Fusarium culture were put on the surface of the medium at the centre of each Petri dish. Subsequent growth of the fungus was assessed by measurement of culture diameters every 24 hours. Linear functions of the Fusarium growth were obtained for Mila control and Atol control. In the case of Mila, the Fusarium found more favourable conditions for its growth in the presence of juice from irradiated tubers than from the control ones. Making the same comparison for Atol, no difference was detected. (author)

Photo-neutron yields from thin and thick targets irradiated by 2.0 GeV electrons

International Nuclear Information System (INIS)

Hee-Seock, Lee; Syuichi, Ban; Toshiya, Sanami; Kazutoshi, Takahashi; Tatsuhiko, Sato; Kazuo, Shin

2005-01-01

The photo-neutron yields from thin and thick targets irradiated by high energy electrons were studied. The photo-neutron spectra at 90 deg C relative to the incident 2.0 GeV electrons were measured by the pulsed beam time-of-flight technique using the Pilot-U plastic scintillator and the NE213 liquid scintillator with 2 inches in length and 2 inches in diameter. Targets, from low-Z element (carbon) to high-Z element (bismuth) and with thin (0.5 Xo) and thick (10 Xo) thickness, were used in this study. The differential photo-neutron yields between 2 MeV (mainly 8 MeV) and 400 MeV were obtained. The systematics was studied to make empirical yield terms for shielding application. Recently, the study of the angular distributed yields was conducted at two other observing angles, 48 deg C and 140 deg C. The photo-neutron yields between 8 MeV and 250 MeV were obtained for thick targets. The experimental data were compared with results calculated using the EGS4+PICA3 or the MCNPX 2.5d code. (authors)

Optical histology: a method to visualize microvasculature in thick tissue sections of mouse brain.

Directory of Open Access Journals (Sweden)

Austin J Moy

Full Text Available The microvasculature is the network of blood vessels involved in delivering nutrients and gases necessary for tissue survival. Study of the microvasculature often involves immunohistological methods. While useful for visualizing microvasculature at the µm scale in specific regions of interest, immunohistology is not well suited to visualize the global microvascular architecture in an organ. Hence, use of immunohistology precludes visualization of the entire microvasculature of an organ, and thus impedes study of global changes in the microvasculature that occur in concert with changes in tissue due to various disease states. Therefore, there is a critical need for a simple, relatively rapid technique that will facilitate visualization of the microvascular network of an entire tissue.The systemic vasculature of a mouse is stained with the fluorescent lipophilic dye DiI using a method called "vessel painting". The brain, or other organ of interest, is harvested and fixed in 4% paraformaldehyde. The organ is then sliced into 1 mm sections and optically cleared, or made transparent, using FocusClear, a proprietary optical clearing agent. After optical clearing, the DiI-labeled tissue microvasculature is imaged using confocal fluorescence microscopy and adjacent image stacks tiled together to produce a depth-encoded map of the microvasculature in the tissue slice. We demonstrated that the use of optical clearing enhances both the tissue imaging depth and the estimate of the vascular density. Using our "optical histology" technique, we visualized microvasculature in the mouse brain to a depth of 850 µm.Presented here are maps of the microvasculature in 1 mm thick slices of mouse brain. Using combined optical clearing and optical imaging techniques, we devised a methodology to enhance the visualization of the microvasculature in thick tissues. We believe this technique could potentially be used to generate a three-dimensional map of the

Proton irradiation impacts age-driven modulations of cancer progression influenced by immune system transcriptome modifications from splenic tissue

International Nuclear Information System (INIS)

Wage, Justin; Ma, Lili; Peluso, Michael; Lamont, Clare; Hahnfeldt, Philip; Hlatky, Lynn; Beheshti, Afshin; Evens, Andrew M.

2015-01-01

Age plays a crucial role in the interplay between tumor and host, with additional impact due to irradiation. Proton irradiation of tumors induces biological modulations including inhibition of angiogenic and immune factors critical to 'hallmark' processes impacting tumor development. Proton irradiation has also provided promising results for proton therapy in cancer due to targeting advantages. Additionally, protons may contribute to the carcinogenesis risk from space travel (due to the high proportion of high-energy protons in space radiation). Through a systems biology approach, we investigated how host tissue (i.e. splenic tissue) of tumor-bearing mice was altered with age, with or without whole-body proton exposure. Transcriptome analysis was performed on splenic tissue from adolescent (68-day) versus old (736-day) C57BL/6 male mice injected with Lewis lung carcinoma cells with or without three fractionations of 0.5 Gy (1-GeV) proton irradiation. Global transcriptome analysis indicated that proton irradiation of adolescent hosts caused significant signaling changes within splenic tissues that support carcinogenesis within the mice, as compared with older subjects. Increases in cell cycling and immunosuppression in irradiated adolescent hosts with CDK2, MCM7, CD74 and RUVBL2 indicated these were the key genes involved in the regulatory changes in the host environment response (i.e. the spleen). Collectively, these results suggest that a significant biological component of proton irradiation is modulated by host age through promotion of carcinogenesis in adolescence and resistance to immunosuppression, carcinogenesis and genetic perturbation associated with advancing age. (author)

Influence of chronic internal and acute external irradiations on the critical tissues of plants

International Nuclear Information System (INIS)

Kostyuk, O.P.; Ryasnenko, N.A.; Grodzins'kij, D.M.

1998-01-01

Peculiarities of chronic internal and acute external irradiations of the critical (as for irradiation influence) plants part, meristem, are studied. In particular, the investigation has aimed to evaluate the level of doses, accumulated by plant tissues, of the chronic internal irradiation from radiocaesium incorporated by them, and to compare its possible effect to one caused by the acute external irradiation. It is shown that the effects of both chronic and acute irradiations have similar features, and it is assumed that they have the very same mechanisms. We think that such a parameter of the plant ability to accumulate radiocaesium as the ratio of its content in a root tip and in the whole root system is a very sensible and useful criterion to estimate the irradiation influence on plants

Analysis of DNA vulnerability to damage, repair and degradation in tissues of irradiated animals

International Nuclear Information System (INIS)

Ryabchenko, N.I.; Ivannik, B.P.

1982-01-01

Single-strand and paired ruptures of DNA were found to result in appearance of locally denaturated areas in its secondary structure and to disordered protein-DNA interaction. It was shown with the use of the viscosimeter method of measuring the molecular mass of single stranded high-polymeric DNA that cells of various tissues by the intensity of DNA repair can be divided into two groups, rapid- and slow-repair ones. Tissue specificity of enzyme function of the repair systems and systems responsible for post-irradiation DNA degradation depends on the activity of endonucleases synthesized by the cells both in health and in their irradiation-induced synthesis

Detailed measurements of local thickness changes for U-7Mo dispersion fuel plates with Al-3.5Si matrix after irradiation at different powers in the RERTR-9B experiment

Science.gov (United States)

Keiser, Dennis D.; Williams, Walter; Robinson, Adam; Wachs, Dan; Moore, Glenn; Crawford, Doug

2017-10-01

The Materials Management and Minimization program is developing fuel designs to replace highly enriched fuel with fuels of low enrichment. Swelling is an important irradiation behavior that needs to be well understood. Data from high resolution thickness measurements performed on U-7Mo dispersion fuel plates with Al-Si alloy matrices that were irradiated at high power is sparse. This paper reports the results of detailed thickness measurements performed on two dispersion fuel plates that were irradiated at relatively high power to high fission densities in the Advanced Test Reactor in the same RERTR-9B experiment. Both plates were irradiated to similar fission densities, but one was irradiated at a higher power than the other. The goal of this work is to identify any differences in the swelling behavior when fuel plates are irradiated at different powers to the same fission densities. Based on the results of detailed thickness measurments, more swelling occurs when a U-7Mo dispersion fuel with Al-3.5Si matrix is irradiated to a high fission density at high power compared to one irradiated at a lower power to high fission density.

Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

Directory of Open Access Journals (Sweden)

Muhammed Bora Demircelik

2014-06-01

Full Text Available OBJECTIVE:The aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease.METHODS:The study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing <50% in diameter, Group 2; and obstructive atherosclerosis (luminal narrowing ≥50% in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium. Epicardial adipose tissue thickness (mm was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses.RESULTS:The average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm.CONCLUSION:We showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases.

Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

Energy Technology Data Exchange (ETDEWEB)

Demircelik, Muhammed Bora; Gurel, Ozgul Malcok; Selcoki, Yusuf; Atar, Inci Asli; Eryonucu, Beyhan, E-mail: drdemircelik@yahoo.com [Turgut Ozal Univercity, Department of Cardiology, Ankara (Turkey); Bozkurt, Alper; Akin, Kayihan [Turgut Ozal Univercity, Department of Radiology, Ankara (Turkey); Yilmaz, Omer Caglar [Ankara Occupational Diseases Hospital, Department of Cardiology, Ankara (Turkey)

2014-06-15

Objective: the aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease. Methods: the study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing < 50% in diameter), Group 2; and obstructive atherosclerosis (luminal narrowing ≧ 50%) in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium). Epicardial adipose tissue thickness (mm) was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses. Results: the average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm. Conclusion: we showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases. (author)

Epicardial adipose tissue and pericoronary fat thickness measured with 64-multidetector computed tomography: potential predictors of the severity of coronary artery disease

International Nuclear Information System (INIS)

Demircelik, Muhammed Bora; Gurel, Ozgul Malcok; Selcoki, Yusuf; Atar, Inci Asli; Eryonucu, Beyhan; Bozkurt, Alper; Akin, Kayihan; Yilmaz, Omer Caglar

2014-01-01

Objective: the aim of the present study was to investigate the relationship between pericoronary fat and the severity and extent of atherosclerosis, quantified using 64-multidetector computed tomography, in patients with suspected coronary artery disease. Methods: the study population consisted of 131 patients who were clinically referred for noninvasive multislice computed tomography coronary angiography for the evaluation of coronary artery disease. Patients were classified as follows: no atherosclerosis, Group 1; nonobstructive atherosclerosis (luminal narrowing < 50% in diameter), Group 2; and obstructive atherosclerosis (luminal narrowing ≧ 50%) in a single vessel or obstructive atherosclerosis in the left main coronary artery and/or multiple vessels, Group 3. Epicardial adipose tissue was defined as the adipose tissue between the surface of the heart and the visceral layer of the pericardium (visceral epicardium). Epicardial adipose tissue thickness (mm) was determined in the right ventricular anterior free wall. The mean thickness of the pericoronary fat surrounding the three coronary arteries was used for the analyses. Results: the average thickness over all three regions was 13.2 ± 2.1 mm. The pericoronary fat thickness was significantly increased in Group 3 compared with Groups 2 and 1. The epicardial adipose tissue thickness was significantly increased in Group 3 compared with Groups 2 and 1. A receiver operating characteristic curve for obstructive coronary artery disease was assessed to verify the optimum cut-off point for pericoronary fat thickness, which was 13.8 mm. A receiver operating characteristic curve for obstructive coronary artery disease was also assessed to verify the optimum cut-off point for epicardial adipose tissue, which was 6.8 cm. Conclusion: we showed that the epicardial adipose tissue and pericoronary fat thickness scores were higher in patients with obstructive coronary artery diseases. (author)

Inhibition of proliferative activity in tissue culture in vivo of esophagus and stomach tumour cells under preoperative irradiation

International Nuclear Information System (INIS)

Zinchenko, V.A.; Okulov, L.V.; Gol'dshmid, B.Ya.

1988-01-01

Inhibition of proliferative activity of tumor cells as a result of radiation effect. Tumor tissue taken from patiets with preoperative tumor irradiation by 30 Gy cumulative dose (5 Gy per a session) and from patients whose tumors were not subjected to irradiation (control) was used. The tumor tissue was cultivated in the diffusion chamber and then implanted to the abdominal cavity of the non-inbred male rats. On preparations in the growth area pathomorphological changes were evaluated, the share of mitotically dividing and DNA-synthesizing cells was determined. The absence of growth area around the explant, obvious reduction of mitotic activity and DNA-synthesizing function of cells in preparations of irradiated tumors in 88 % of cases testify to the inhibition of the stomach cardial section and esophagus tumor tissue repopulation after radiation effect. The investigation results confirm the advisability of preoperative irradiation of patients with tumors of the given localization

Study on changes of sperm count and testis tissue in black mouse after neutron irradiation

Energy Technology Data Exchange (ETDEWEB)

Chun, Ki Jung; Seo, Won Sook [KAERI, Daejeon (Korea, Republic of); Son, Hwa Young [Chungnam National Univ., Daejeon (Korea, Republic of)

2006-03-15

For the purpose of the biological effect in black mouse by neutron irradiation, mice were irradiated with 16 or 32 Gy neutron (flux: 1.036739E+09) by lying flat pose at BNCT facility on HANARO Reactors. And 90 days later of irradiation, physical changes of testis and testis tissue were examined. There were no weight changes but a little bit volume changes and sperm counts in the tests. Atrophy of seminiferous tubules irradiated with 32 Gy neutron is increased in number and severity and those in stage VI showed depletion of spermatogonia and pachytene spermatocytes compared to the non-irradiated control group. Testis damage of black mouse was not recovered after long time by 32 Gy neutron irradiation.

Study on changes of sperm count and testis tissue in black mouse after neutron irradiation

International Nuclear Information System (INIS)

Chun, Ki Jung; Seo, Won Sook; Son, Hwa Young

2006-01-01

For the purpose of the biological effect in black mouse by neutron irradiation, mice were irradiated with 16 or 32 Gy neutron (flux: 1.036739E+09) by lying flat pose at BNCT facility on HANARO Reactors. And 90 days later of irradiation, physical changes of testis and testis tissue were examined. There were no weight changes but a little bit volume changes and sperm counts in the tests. Atrophy of seminiferous tubules irradiated with 32 Gy neutron is increased in number and severity and those in stage VI showed depletion of spermatogonia and pachytene spermatocytes compared to the non-irradiated control group. Testis damage of black mouse was not recovered after long time by 32 Gy neutron irradiation

Research progress in plant mutation by combining ion beam irradiations and tissue culture

International Nuclear Information System (INIS)

Zhou Linbin; Li Wenjian; Qu Ying; Li Ping

2007-01-01

About a new mutation breeding method which combines plant tissue culture technique with heavy ion beam irradiations were discussed in this paper with the principles, operation steps, molecular mechanisms, etc. The mutation method developed a few advantages coming from plant tissue culture, which can produce offspring by asexual ways. Meanwhile, using this method, the study of biological effects of high energy particles with different linear energy transfer values on plant tissues or cells can be explored and optimized in theory or practice. (authors)

Simulation of X-ray irradiation on human hand

International Nuclear Information System (INIS)

Amaya, Fabiola; Montoya, Modesto

2001-01-01

Using the Monte Carlo code MCNP we simulate a human hand X-rays irradiation with radiodiagnostic energies to find the better range energy to make radiographs with the lowest dose and an optimal contrast. We calculate bone doses by considering a soft tissue - water - and calcium bone hand, which is irradiated with a million of X-rays photons from a punctual source. These photons are directed inside a conic angle on the hand. Afterwards, we simulate elements which normally compose bones (C, H, O, N, Mg, P, Ca, and S). We estimate bone dose considering: a) bone material (water, calcium and bone tissue); b) bone thickness (0.01; 0.1; 0.5; 1.0; 1.5 and 3.0 cm); and c) source-hand distance (30, 50, 70 and 90 cm). We calculate photon transmission percent through soft tissue and bone tissue and the statistics from the number of photons that reach the radiographic film after passing through soft tissue or bone tissue for our geometric configuration. We found that we can obtain a good image contrast by using X-rays with energies in the range of 20 to 40 keV. (author)

Effect of high-frequency near-infrared diode laser irradiation on periodontal tissues during experimental tooth movement in rats.

Science.gov (United States)

Gunji, Hidemi; Kunimatsu, Ryo; Tsuka, Yuji; Yoshimi, Yuki; Sumi, Keisuke; Awada, Tetsuya; Nakajima, Kengo; Kimura, Aya; Hiraki, Tomoka; Hirose, Naoto; Yanoshita, Makoto; Tanimoto, Kotaro

2018-02-05

Tooth movement during orthodontic treatment is associated with bone neoplasticity and bone resorption on the tension and pressure sides. Previous clinical studies have suggested that low-power laser irradiation can accelerate tooth movement during orthodontic treatment, although the underlying mechanism remains unclear. In this study, we used a high-frequency near-infrared diode laser that generates less heat and examined the histologic changes in periodontal tissue during experimental tooth movement with laser irradiation. A nickel-titanium closed coil was mounted between the maxillary left side first molar and incisor of rats to model experimental tooth movement. The laser-irradiation and the control groups were set, and the amount of movement of the first molar on 7th and 14th days after the start of pulling of the first molar tooth on the maxillary left was measured by three-dimensional analysis of µCT. After tooth movement, tissue samples from the mesial and tension sides were collected, and successive horizontal sections were prepared and examined using hematoxylin-eosin and TRAP staining and immunohistochemical staining for RANKL, OPG, ALP, and proliferating cell nuclear antigen (PCNA). Changes in tissue temperature following laser irradiation were also examined. Laser irradiation significantly increased tooth movement compared with non-irradiated controls. Histologic staining of the pressure-side mesial root in laser-irradiated rats revealed enhanced RANKL expression and increased numbers of TRAP-positive cells compared with controls. By contrast, on the tension side, laser irradiation led to increased expression of ALP and PCNA. These data indicate that high-frequency near-infrared diode laser irradiation on the pressure side upregulates RANKL expression and accelerates osteoclast differentiation, facilitating bone resorption, whereas bone formation is induced on the tension side. This study demonstrates that high-frequency near-infrared diode laser

The irradiation action on human dental tissue by X-rays and electrons. A nanoindenter study

Energy Technology Data Exchange (ETDEWEB)

Fraenzel, Wolfgang [Halle-Wittenberg Univ., Halle (Germany). Dept. of Physics; Gerlach, Reinhard [Halle-Wittenberg Univ., Halle (Germany). Clinic of Radiation Therapy

2009-07-01

It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue. (orig.)

The irradiation action on human dental tissue by X-rays and electrons. A nanoindenter study

International Nuclear Information System (INIS)

Fraenzel, Wolfgang; Gerlach, Reinhard

2009-01-01

It is known that ionizing radiation is used in medicine for Roentgen diagnostics and for radiation therapy. The radiation interacts with matter, in particular with biological one, essentially by scattering, photoelectric effect, Compton effect and pair production. To what extent the biological material is changed thereby, depends on the type and the amount of radiation energy, on the dose and on the tissue constitution. In modern radiation therapy two different kinds of radiation are used: high energy X-rays and electron radiation. In the case of head-neck tumors the general practice is an irradiation with high energy X-rays with absorbed dose to water up to 70 Gy. Teeth destruction has been identified as a side effect during irradiation. In addition, damage to the salivary glands is often observed which leads to a decrease or even the complete loss of the salivary secretion (xerostomia). This study shows how the different energy and radiation types damage the tooth tissue. The effects of both, high X-ray energy and high energy electrons, on the mechanical properties hardness and elasticity of the human dental tissue are measured by the nanoindentation technique. We compare these results with the effect of the irradiation of low X-ray energy on the dental tissue. (orig.)

Validity of soft-tissue thickness of calf measured using MRI for assessing unilateral lower extremity lymphoedema secondary to cervical and endometrial cancer treatments

International Nuclear Information System (INIS)

Lu, Qing; Li, Yulai; Chen, Tian-Wu; Yao, Yuan; Zhao, Zizhou; Li, Yang; Xu, Jianrong; Jiang, Zhaohua; Hu, Jiani

2014-01-01

Aim: To determine whether soft-tissue thickness of the calf measured using MRI could be valid for assessing unilateral lower extremity lymphoedema (LEL) secondary to cervical and endometrial cancer treatments. Materials and methods: Seventy women with unilateral LEL and 25 without LEL after cervical or endometrial cancer treatments underwent MRI examinations of their calves. Total thickness of soft-tissue (TT), muscle thickness (MT), and subcutaneous tissue thickness (STT) of the calf, and the difference between the affected and contralateral unaffected calf regarding TT (DTT), MT (DMT), and STT (DSTT) were obtained using fat-suppressed T2-weighted imaging in the middle of the calves. The volume of the calf and difference in volume (DV) between calves were obtained by the method of water displacement. Statistical analysis was performed to determine the validity of MRI measurements by volume measurements in staging LEL. Results: There was a close correlation between volume and TT for the affected (r = 0.927) or unaffected calves (r = 0.896). STT of the affected calf, and DTT or DSTT of the calves were closely correlated with volume of the affected calf or DV of the calves (all p < 0.05). Multivariate analysis showed significant differences in TT, STT, volume of the affected calf, DTT, DSTT, and DV between stages except in volume of the affected calf or in DV between stage 0 and 1. For staging LEL, DSTT showed the best discrimination ability among all the parameters. Conclusions: Soft-tissue thickness of the calf measured at MRI could be valid for quantitatively staging unilateral LEL, and DSTT of the calves could be the best classifying factor. - Highlights: • The soft tissue thickness of calves on MRI could quantitatively assess secondary LEL. • Calf soft tissue thickness indicated concurrent or construct validity of calf volume. • The difference of subcutaneous tissue thickness of calves could be used to stage LEL

Models for radiation-induced tissue degeneration and conceptualization of rehabilitation of irradiated tissue by cell therapy

International Nuclear Information System (INIS)

Phulpin, Berengere

2011-01-01

Radiation therapy induced acute and late sequelae within healthy tissue included in the irradiated area. In general, lesions are characterized by ischemia, cell apoptosis and fibrosis. In this context, cell therapy using bone marrow mesenchymal stem cells (BMSC) might represent an attractive new therapeutic approach, based partly on their angiogenic ability and their involvement in the natural processes of tissue repair. The first part of this work consisted in the development of experimental mouse model of radio-induced tissue degeneration similar to that occurring after radiotherapy. The aim was to better understand the physiopathological mechanisms of radiation-induced tissue damage and to determine the best treatment strategy. The second part of this work investigated the feasibility of autologous BMSC therapy on the murine model of radiation previously established with emphasis on two pre-requisites: the retention of the injected cells within the target tissue and the evaluation of the graft on bone metabolism. This preclinical investigation in a mouse model constitutes an essential step allowing an evaluation of the benefit of cell therapy for the treatment of radiation-induced tissue injury. Data from these studies could allow the proposal of clinical studies [fr

Modulatory Role of Aloe vera on Gamma Irradiation Induced Histological Changes in Different Tissues of Rats

International Nuclear Information System (INIS)

Rezk, R.G.

2005-01-01

Aloe Vera is known for its wide medicinal properties. This study was performed to evaluate the role of Aloe vera (Aloe barbadensis Miller) in the amelioration of the histological disorders that occurr in different tissues of albino rats exposed to 7 Gy whole body gamma irradiation, delivered as a single dose. Aloe vera (leaf juice filtrate) was supplemented daily to rats (0.25 ml/kg b wt/day) by gavage, 5 days before irradiation and 10 days after irradiation. Experimental investigations performed 7 and 10 days after exposure to radiation showed that Aloe vera treatment has significantly improved the radiation-induced inflammation, haemorrhage, widening and dilated blood vessela, necrosis, atrophy sloughing in liver, spleen and small intestine (jejenum) tissues of irradiated rats. It is concluded that the synergistic relationship between the elements found in the leaf of Aloe vera could be a useful adjunct for maintaining the integrity of histological architecture

Expression of HIF-1{alpha} in irradiated tissue is altered by topical negative-pressure therapy

Energy Technology Data Exchange (ETDEWEB)

Grimm, A.; Stange, S.; Labanaris, A.; Horch, R.E. [Erlangen-Nuernberg Univ., Erlangen (Germany). Dept. of Plastic and Hand Surgery; Dimmler, A. [Erlangen-Nuernberg Univ., Erlangen (Germany). Dept. of Pathology; Sauer, R.; Grabenbauer, G. [Erlangen-Nuernberg Univ. (Germany). Dept. of Radiation Oncology

2007-03-15

Background and Purpose: Despite the enormous therapeutic potential of modern radiotherapy, common side effects such as radiation-induced wound healing disorders remain a well-known clinical phenomenon. Topical negative pressure therapy (TNP) is a novel tool to alleviate intraoperative, percutaneous irradiation or brachytherapy. Since TNP has been shown to positively influence the perfusion of chronic, poorly vascularized wounds, the authors applied this therapeutic method to irradiated wounds and investigated the effect on tissue oxygenation in irradiated tissue in five patients. Material and Methods: With informed patients' consent, samples prior to and 4 and 8 days after continuous TNP with -125 mmHg were obtained during routine wound debridements. Granulation tissue was stained with hematoxylin-eosin, and additionally with CD31, HIF-1{alpha} (hypoxia-inducible factor-1{alpha}), and D2-40 to detect blood vessels, measure indirect signs of hypoxia, and lymph vessel distribution within the pre- and post-TNP samples. Results: In this first series of experiments, a positive influence of TNP onto tissue oxygenation in radiation-induced wounds could be demonstrated. TNP led to a significant decrease of 53% HIF-1{alpha}-positive cell nuclei. At the same time, a slight reduction of CD31-stained capillaries was seen in comparison to samples before TNP. Immunostaining with D2-40 revealed an increased number of lymphatic vessels with distended lumina and an alteration of the parallel orientation within the post-TNP samples. Conclusion: This study is, to the authors' knowledge, the first report on a novel previously not described histological marker to demonstrate the effects of TNP on HIF-1{alpha} expression as an indirect marker of tissue oxygenation in irradiated wounds, as demonstrated by a reduction of HIF-1{alpha} concentration after TNP. Since this observation may be of significant value to develop possible new strategies to treat radiation-induced tissue

Expression of HIF-1α in irradiated tissue is altered by topical negative-pressure therapy

International Nuclear Information System (INIS)

Grimm, A.; Stange, S.; Labanaris, A.; Horch, R.E.; Dimmler, A.; Sauer, R.; Grabenbauer, G.

2007-01-01

Background and Purpose: Despite the enormous therapeutic potential of modern radiotherapy, common side effects such as radiation-induced wound healing disorders remain a well-known clinical phenomenon. Topical negative pressure therapy (TNP) is a novel tool to alleviate intraoperative, percutaneous irradiation or brachytherapy. Since TNP has been shown to positively influence the perfusion of chronic, poorly vascularized wounds, the authors applied this therapeutic method to irradiated wounds and investigated the effect on tissue oxygenation in irradiated tissue in five patients. Material and Methods: With informed patients' consent, samples prior to and 4 and 8 days after continuous TNP with -125 mmHg were obtained during routine wound debridements. Granulation tissue was stained with hematoxylin-eosin, and additionally with CD31, HIF-1α (hypoxia-inducible factor-1α), and D2-40 to detect blood vessels, measure indirect signs of hypoxia, and lymph vessel distribution within the pre- and post-TNP samples. Results: In this first series of experiments, a positive influence of TNP onto tissue oxygenation in radiation-induced wounds could be demonstrated. TNP led to a significant decrease of 53% HIF-1α-positive cell nuclei. At the same time, a slight reduction of CD31-stained capillaries was seen in comparison to samples before TNP. Immunostaining with D2-40 revealed an increased number of lymphatic vessels with distended lumina and an alteration of the parallel orientation within the post-TNP samples. Conclusion: This study is, to the authors' knowledge, the first report on a novel previously not described histological marker to demonstrate the effects of TNP on HIF-1α expression as an indirect marker of tissue oxygenation in irradiated wounds, as demonstrated by a reduction of HIF-1α concentration after TNP. Since this observation may be of significant value to develop possible new strategies to treat radiation-induced tissue injury, further investigations of HIF

Project on production of mutants by irradiation of in vitro cultured tissues of coconut and banana and their mass propagation by the tissue culture technique

International Nuclear Information System (INIS)

Guzman, E.V. de

1975-01-01

Fruit pulp tissue, ovary segments with or without ovules and sections from shoot tips of banana were used for studies on growth stimulating or morphogenetic effects of irradiation. Irradiation at 0.1-1.0 kR tended to induce faster callus growth in the otherwise slow-growing cultures. The physical condition and composition of the culture media especially with respect to growth regulators were studied, as were techniques to overcome discoloration of explants, the best choice of plant tissue for explant, and radiation effects on growth and morphogenesis. Due to the difficulty of callus induction with coconut, only the effects of irradiation on embryos cultured in vitro were studied. They were irradiated at various stages of development, i.e. during the early and final stage of liquid culture, and several days after transfer to a solid medium. Adverse effects of irradiation became evident only during the subsequent growth in solid, during the latter stage of which morphological changes were observed. Whereas irradiation of the liquid as well as solid media up to 50 kR had no adverse effect; survival and development became adversely affected at a dose of 1 kR

Modulation of scar tissue formation using different dermal regeneration templates in the treatment of experimental full-thickness wounds.

NARCIS (Netherlands)

Druecke, D.; Lamme, E.N.; Hermann, S.; Pieper, J.S.; May, P.S.; Steinau, H.U.; Steinstraesser, L.

2004-01-01

The recovery of skin function is the goal of each burn surgeon. Split-skin graft treatment of full-thickness skin defects leads to scar formation, which is often vulnerable and instable. Therefore, the aim of this study was to analyze wound healing and scar tissue formation in acute full-thickness

DOMPAC dosimetry experiment. Neutronic simulation of the thickness of a PWR pressure vessel. Irradiation damages

International Nuclear Information System (INIS)

Alberman, A.; Faure, M.; Thierry, M.; Hoclet, O.; Le Dieu de Ville, A.; Nimal, J.C.; Soulat, P.

1979-01-01

For suitable extrapolation of irradiated PWR ferritic steel results, proper irradiation of the pressure vessel has been 'simulated' in test reactor. For this purpose, a huge steel block (20 cm in depth) was loaded with Saclay's graphite (GAMIN) and tungsten damage detectors. Core-block water gap was optimized through spectrum indexes method, by ANISN and SABINE codes so that spectrum in 1/4 thickness matches with ANISN computations for PWR Fessenheim 1. A good experimental agreement is found with calculated dpa damage gradient. 3D Monte Carlo computation (TRIPOLI), was performed on the DOMPAC device, and spectrum indexes evolution was found consistent with experimental results. Surveillance rigs behind a 'thermal shield' were also simulated, including damage and activation monitors. Dosimetry results give an order of magnitude of accuracies involved in projecting steel sample embrittlement to the pressure vessel [fr

Advantageous use of SSA technique to observe effects of thickness, antioxidant and oxygen in gamma irradiated low density polyethylene

Energy Technology Data Exchange (ETDEWEB)

Perez, C.J., E-mail: cjperez@fi.mdp.edu.ar [Research Institute of Material Science and Technology (INTEMA), National Research Council (CONICET), Engineering Faculty, Mar del Plata University, Av. J.B. Justo 4302, 7600 Mar del Plata (Argentina); Failla, M.D. [Planta Piloto de Ingenieria Quimica-PLAPIQUI (UNS-CONICET), Camino ' La Carrindanga' Km 7, 8000 Bahia Blanca (Argentina); Carella, J.M. [Research Institute of Material Science and Technology (INTEMA), National Research Council (CONICET), Engineering Faculty, Mar del Plata University, Av. J.B. Justo 4302, 7600 Mar del Plata (Argentina)

2012-06-20

Highlights: Black-Right-Pointing-Pointer Information from successive self-nucleation and annealing technique is analyzed. Black-Right-Pointing-Pointer Oxygen and antioxidants reduce crosslinking efficiency by reaction with free radicals. Black-Right-Pointing-Pointer Recognizable differences are obtained in samples irradiated at different atmospheres. - Abstract: Information obtained from successive self-nucleation and annealing (SSA) technique is analyzed, paying special attention to the observable effects of samples thickness and antioxidant and oxygen concentrations. Molecular structure changes for low density polyethylene (LDPE) samples, irradiated under three different atmospheres for doses between 33 and 222 kGy were analyzed, with emphasis on the changes of longer polymethylene crystallizable lengths. Antioxidant and oxygen concentrations were varied for samples of different thickness to study the effects on degradation. The changes in the molecular structure were followed simultaneously by SSA and Infrared spectroscopy (FTIR) via carbonyl group concentration. Preliminary quantifications of the SSA technique sensitivity are also advanced.

Alteration of phospholipase D activity in the rat tissues by irradiation

Energy Technology Data Exchange (ETDEWEB)

Choi, M. S. [Korea Univ., Seoul (Korea, Republic of). Coll. of Medicine; Cho, Y. J. [Hanyang Univ., Seoul (Korea, Republic of). Coll. of Medicine; Choi, M. U. [Seoul National Univ. (Korea, Republic of). Coll. of Natural Sciences

1997-09-01

Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine to phosphatidic acid (PA) and choline. Recently, PLD has been drawing much attentions and considered to be associated with cancer process since it is involved in cellular signal transduction. In this experiment, oleate-PLD activities were measured in various tissues of the living rats after whole body irradiation. The reaction mixture for the PLD assay contained 0.1{mu}Ci 1,2-di[1-{sup 14}C]palmitoyl phosphatidylcholine, 0.5mM phosphatidylcholine, 5mM sodium oleate, 0.2% taurodeoxycholate, 50mM HEPES buffer(pH 6.5), 10mM CaCl{sub 2}, and 25mM KF. phosphatidic acid, the reaction product, was separated by TLC and its radioactivity was measured with a scintillation counter. The whole body irradiation was given to the female Wistar rats via Cobalt 60 Teletherapy with field size of 10cm x 10cm and an exposure of 2.7Gy per minute to the total doses of 10Gy and 25Gy. Among the tissues examined, PLD activity in lung was the highest one and was followed by kidney, skeletal muscle, brain, spleen, bone marrow, thymus, and liver. Upon irradiation, alteration of PLD activity was observed in thymus, spleen, lung, and bone marrow. Especially PLD activities of the spleen and thymus revealed the highest sensitivity toward {gamma}-ray with more than two times amplification in their activities. In contrast, the PLD activity of bone marrow appears to be reduced to nearly 30%. Irradiation effect was hardly detected in liver which showed the lowest PLD activity. The PLD activities affected most sensitively by the whole-body irradiation seem to be associated with organs involved in immunity and hematopoiesis. This observation strongly indicates that the PLD is closely related to the physiological function of these organs. Furthermore, radiation stress could offer an important means to explore the phenomena covering from cell proliferation to cell death on these organs. (author).

Study of temperature increase and optic depth penetration in photo irradiated human tissues

International Nuclear Information System (INIS)

Stolik, Suren; Delgado, Jose A.; Perez, Arllene M.; Anasagasti, Lorenzo

2009-01-01

Optical radiation is widely applied in the treatment and diagnosis of different pathologies. If the power density of the incident light is sufficiently high to induce a significant temperature rise in the irradiated tissue, then it is also needed the knowledge of the thermal properties of the tissue for a complete understanding of the therapeutic effects. The thermal penetration depth of several human tissues has been measured applying the diffusion approximation of the radiative transfer equation for the distribution of optical radiation. The method, the experimental setup and the results are presented and discussed. (Author)

Effects of sub-lethal dose of γ-irradiation on lysosomal enzymes in tissue of pigeon

International Nuclear Information System (INIS)

Shah, V.C.; Gadhia, P.K.

1979-01-01

Effects of total body γ-irradiation with sub-lethal dose (300 rad) on three lysosomal enzymes namely acid phosphatase, ribonuclease-II and deoxyribonuclease-II have been studied in pigeons. Liver, kidney and spleen were the tissues studied at different intervals like 1-h, 24-h, 48-h, and 72-h of irradiation. The specific activities ('crude' fraction) of acid phosphatase and ribonuclease-II increased significantly in spleen and liver at 48-h of irradiation. The activity of deoxyribonuclease-II in liver and spleen was increased only at 72-h post-irradiation. On the other hand, the total activities of three lysosomal enzymes did not show remarkable change throughout 72-h of irradiation. (author)

Whole-body γ-irradiation effects on catecholamine concentration in animal tissues

International Nuclear Information System (INIS)

Makashev, Zh.K.; Uteshev, T.A.; Abylaev, Zh. A.; Zhurnist, A.G.

2003-01-01

On the whole-body gamma-radiation activity in the exchanges of catecholamines (adrenalin and non-adrenalin) and their predecessors (dopamine and DOPA) in the rats tissue organism, indicate the infringement of irradiated animals in different links of biological synthesis the bio-gen amines in different phases of the radiation: DOPA→dopamine, dopamine→adrenalin, adrenalin→non-adrenalin. (author)

Reverse tissue expansion by liposuction deflation adopted for harvest of large sheet of full-thickness skin graft.

Science.gov (United States)

Ibrahim, A E; Debbas, C C; Dibo, S A; Atiyeh, B S; Abu-Sittah, G S; Isik, S

2012-06-30

Full-thickness skingraft is a valid option to release burn scar contractures with the main purpose of correcting the induced limitation in function and improve the disfiguring appearance of the scar. The main pitfall remains the limited availability of these grafts, especially when large sheets are needed. We present an application of a previously described technique known as reverse tissue expansion, which permits the harvesting of a large sheet of full thickness skin graft when needed. This method was adopted to release a burn scar contracture in a 32-yr-old man who sustained a 65% TBSA burn secondary to a gasoline tank explosion at the age of 7 yr followed by multiple reconstructive procedures. The patient presented with a disfiguring anterior neck contracture coupled to limited range of motion. Improvement of neck extension was contemplated using full-thickness skin graft harvested following reverse tissue expansion achieved by deflation liposuction of the donor site.

Repopulation of the Stem-Cell Compartment in Haemopoietic and Lymphatic Tissues of Mice after X-Irradiation

Energy Technology Data Exchange (ETDEWEB)

Vos, O. [Medical Biological Laboratory of the National Defense Organization TNO, Rijswijk Z.H. (Netherlands)

1968-08-15

Repopulation in haemopoietic tissues of mice was studied at various times after irradiation with a sub-lethal X-ray dose of 460 R and after exposure to a lethal X-ray dose of 800 R followed by transplantation of 4 x 10{sup 6} syngeneic bone-marrow cells. The number of stem cells was determined with the exogenous and endogenous spleen colony technique in the bone-marrow of the femur and in the spleen. Repopulation in lymphatic tissues was investigated at various times after sub-lethal irradiation with 460 R, sub-lethal irradiation with 460 R followed by allogeneic skin transplantation, lethal irradiation with 800 R followed by transplantation of 2 x 10{sup 6} syngeneic bone-marrow cells, and irradiation with 800 R followed by transplantation of 2 x 10{sup 6} and 5 x 10{sup 6} syngeneic bone-marrow and lymph node cells, respectively. The number of stem cells was estimated in the spleen and in lymph nodes with a technique based on a graft-versus- host reaction. The results showed that a rapid repopulation occurred in haemopoietic tissues under all circumstances. In the spleen an overshoot was found during a period beginning shortly after the 7th day and lasting for some weeks. In lymphatic tissues repopulation by stem cells was slow. During the first one or two weeks some decrease was even observed. This was followed by a slow repopulation that around 100 days after irradiation reached a level slightly below that found in control animals. Small differences of repopulation in the various organs and under different circumstances are discussed. It was postulated that immuno-competent lymphatic stem cells (antigen-sensitive cells or PC{sub 1} cells) do not proliferate or do so only to a limited extent. This compartment must be replenished by repopulation of differentiating stem cells from the bone marrow. It seems probable that stem-cell depletion or antigeneic stimulation has only a marginal effect upon repopulation. (author)

Results of total lung irradiation and chemotherapy in comparison with partial lung irradiation in metastatic undifferentiated soft tissue sarcomas

Energy Technology Data Exchange (ETDEWEB)

Zamboglou, N.; Fuerst, G.; Pape, H.; Bannach, B.; Schmitt, G.; Molls, M.

1988-07-01

The poor prognosis of patients with unresectable pulmonary metastases of soft tissue sarcoma is well known. In order to evaluate the beneficial effect of radiotherapy, we have treated 44 patients with pulmonary metastases of grade 3 soft tissue sarcoma from 1980 to 1986. In 36 patients the treatment volume was restricted to the single metastases up to a dose of 50 to 60 (9 to 10 Gy/week). The survival rate at one year was 18% and at two years 6%. Eight patients were treated with a combined regimen, consisting of cisplatin and ifosfamide with simultaneous whole lung irradiation. Irradiation was performed with 8 or 16 MV photons at a hyperfractionation of 2x0,8 Gy/day (8 Gy/week). After a dose of 12 Gy, the single metastases were boosted up to 50 to 60 Gy, with a second course of chemotherapy. In six of eight patients complete remissions were achieved, one patient showed a partial remission. The survival rate at 27 months was 50%. The patients with partial remission died from pulmonary progression at 23 months. One patient died after twelve months from a loco-regional recurrence in the tonsillar fossa without evidence of pulmonary disease. Side effects included alopecia and moderate bone marrow suppression approximately twelve days after each chemotherapy cycle. Pulmonary fibrosis was observed only at the high dose volume without impairment of respiratory function. From these observations the conclusion is drawn that whole lung irradiation simultaneously with cisplatin and ifosfamide chemotherapy provides good palliative results without relevant morbidity in patients with high grade unresectable pulmonary metastases of soft tissue sarcomas.

Facial soft tissue thicknesses: Noise, signal, and P.

Science.gov (United States)

Stephan, Carl N; Munn, Lachlan; Caple, Jodi

2015-12-01

Facial soft tissue thicknesses (FSTTs) hold an important role in craniofacial identification, forming the underlying quantitative basis of craniofacial superimposition and facial approximation methods. It is, therefore, important that patterns in FSTTs be correctly described and interpreted. In prior FSTT literature, small statistically significant differences have almost universally been overemphasized and misinterpreted to reflect sex and ancestry effects when they instead largely encode nuisance statistical noise. Here we examine FSTT data and give an overview of why P-values do not mean everything. Scientific inference, not mechanical evaluation of P, should be awarded higher priority and should form the basis of FSTT analysis. This hinges upon tempered consideration of many factors in addition to P, e.g., study design, sampling, measurement errors, repeatability, reproducibility, and effect size. While there are multiple lessons to be had, the underlying message is foundational: know enough statistics to avoid misinterpreting background noise for real biological effects. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction: A systematic review.

Science.gov (United States)

Dashe, Jesse; Parisien, Robert L; Cusano, Antonio; Curry, Emily J; Bedi, Asheesh; Li, Xinning

2016-06-18

To evaluate whether anterior cruciate ligament (ACL) allograft irradiation is effective for sterility without compromising graft integrity and increasing failure rate. A literature search was conducted using PubMed, Cochrane, and Google. The following search terms were used: "Gamma irradiation AND anterior cruciate ligament AND allograft" with a return of 30 items. Filters used included: English language, years 1990-2015. There were 6 hits that were not reviewed, as there were only abstracts available. Another 5 hits were discarded, as they did not pertain to the topic of interest. There were 9 more articles that were excluded: Three studies were performed on animals and 6 studies were meta-analyses. Therefore, a total of 10 articles were applicable to review. There is a delicate dosing crossover where gamma irradiation is both effective for sterility without catastrophically compromising the structural integrity of the graft. Of note, low dose irradiation is considered less than 2.0 Mrad, moderate dose is between 2.1-2.4 Mrad, and high dose is greater than or equal to 2.5 Mrad. Based upon the results of the literature search, the optimal threshold for sterilization was found to be sterilization at less than 2.2 Mrad of gamma irradiation with the important caveat of being performed at low temperatures. The graft selection process also must include thorough donor screening and testing as well as harvesting the tissue in a sterile fashion. Utilization of higher dose (≥ 2.5 Mrad) of irradiation causes greater allograft tissue laxity that results in greater graft failure rate clinically in patients after ACL reconstruction. Allograft ACL graft gamma irradiated with less than 2.2 Mrad appears to be a reasonable alternative to autograft for patients above 25 years of age.

The effects of irradiation on the periodontal tissues of rats with the low calcium diet

International Nuclear Information System (INIS)

Choi, Mun Cheol; Lee, Sang Rae

1992-01-01

The purpose of this study was to investigate the changes of periodontal tissues in the irradiated mandibular bone in rats which were fed normal diet and low calcium diet. In order to carry out this experiment, 64 seven-week old Sprague-Dawley strain rats weighing about 150 gms were selected and equally divided into one experimental group of 32 rats and one control group with the remainder. The experimental group and the control group were then subdivided into two groups when the rats reached the age of 10 weeks, 16 rats were allotted for each subdivided group was composed of 16 rats and exposed to irradiation. The two groups were irradiated a single dose of 20 Gy on the only jaw area and irradiated with a cobalt-60 teletherapy unit. The rats in the control and experimental groups were warily dissected by fours on the 3rd, 7th, the 14th, and the 21st day after irradiation. After each dissection, both sides of the dead rat mandibular bodies were removed and fixed with 10% neutral formalin. The specimens sectioned and observed in histopathological, histochemical, and immunocellular chemical methods. The obtained results were as follows: 1. In the mandibles of rats with low calcium diet the increased number of fibroblasts of periodontal ligaments, many small capillaries and irregular arrangement of loose collagen fibers were detected and the partial resorption of dentin and cementum could be found by the microscopic studies. 2. In the group of irradiated rats, deaerated periodontal tissues led to the condition of irregular arrangement of collagen fibers and the decreased number of fibroblasts. But this condition was somewhat restored after 21 days of experiment. 3. Periodontal tissues of the irradiated rat group with low calcium diet were destroyed earlier than those of the irradiated rat group with normal diet. Soon this condition was restored and then high cellularity and dense collagen fibers were observed. 4. Many periodontal cells bearing tumor necrosis factor

Measurement of characteristic prompt gamma rays emitted from oxygen and carbon in tissue-equivalent samples during proton beam irradiation.

Science.gov (United States)

Polf, Jerimy C; Panthi, Rajesh; Mackin, Dennis S; McCleskey, Matt; Saastamoinen, Antti; Roeder, Brian T; Beddar, Sam

2013-09-07

The purpose of this work was to characterize how prompt gamma (PG) emission from tissue changes as a function of carbon and oxygen concentration, and to assess the feasibility of determining elemental concentration in tissues irradiated with proton beams. For this study, four tissue-equivalent water-sucrose samples with differing densities and concentrations of carbon, hydrogen, and oxygen were irradiated with a 48 MeV proton pencil beam. The PG spectrum emitted from each sample was measured using a high-purity germanium detector, and the absolute detection efficiency of the detector, average beam current, and delivered dose distribution were also measured. Changes to the total PG emission from (12)C (4.44 MeV) and (16)O (6.13 MeV) per incident proton and per Gray of absorbed dose were characterized as a function of carbon and oxygen concentration in the sample. The intensity of the 4.44 MeV PG emission per incident proton was found to be nearly constant for all samples regardless of their carbon concentration. However, we found that the 6.13 MeV PG emission increased linearly with the total amount (in grams) of oxygen irradiated in the sample. From the measured PG data, we determined that 1.64 × 10(7) oxygen PGs were emitted per gram of oxygen irradiated per Gray of absorbed dose delivered with a 48 MeV proton beam. These results indicate that the 6.13 MeV PG emission from (16)O is proportional to the concentration of oxygen in tissue irradiated with proton beams, showing that it is possible to determine the concentration of oxygen within tissues irradiated with proton beams by measuring (16)O PG emission.

Internal irradiation for cystic craniopharyngioma

International Nuclear Information System (INIS)

Kobayashi, Tatsuya; Kageyama, Naoki

1979-01-01

Internal irradiation with P-32 chromic phosphate and Au-198 colloid was used to treat cystic craniopharyngioma. A newly developed dosimetric formula, by which the radiation dose can be calculated simultaneously at the cyst wall and at a point far from the radioactive source and the untoward effect of irradiation on surrounding brain tissue can be eliminated, especially in cases in which the wall is thin and can be penetrated by beta emission, was used. Radioactive phosphate or gold was injected into eight craniopharyngioma cysts throught the Ommaya reservoir and a tube inserted at the first craniotomy. All cysts were effectively treated for 3 to 33 months, to eliminate fluid retention or collapse. A collapsed cyst was removed at the second craniotomy and irradiation was histologically shown to be effective. Oculomotor palsy, a side effect of irradiation, occurred 10 days after the injection of 5 mc of P-32 chromic phosphate only in a case of small cysts (5.0 ml) in the supra- and intracellular regions. The thickness of the cyst wall was less than 0.5 mm and the oculomotor nerves were thought to adhere to the wall. Not only the amount of wall dose but also the thickness of the wall and localization of the cyst are important factors in internal irradiation. Sufficient and safer doses which kill tumor cells in the wall and have no side effects, are 9,000 to 30,000 rad. Internal irradiation can be used to treat large cysts of more than 10 ml which are supposedly difficult to remove radically and or multiple cysts. It is effective not only for cystic craniopharyngioma but also for intracrania cystic tumors other than craniopharyngioma, if dosimetry is accurate. (J.P.N.)

Monte Carlo modelling and comparison with experiment of the nuclide production in thick stony targets isotropically irradiated with 600 MeV protons

International Nuclear Information System (INIS)

Aylmer, D.; Herzog, G.F.; Kruse, T.H.; Cloth, P.; Filges, D.; Moniot, R.K.; Signer, P.; Wieler, R.; Tuniz, C.

1987-05-01

Depth profiles for the production of stable and radioactive nuclides have been measured for a large variety of target elements in three thick spherical stony targets with radii of 5, 15 and 26 cm isotropically irradiated with 600 MeV protons at the CERN synchrocyclotron. These irradiation experiments (CERN SC96) were intended to simulate the irradiation of meteoroids by galactic cosmic ray protons. In order to combine this experimental approach with a theoretical one the intra- and internuclear cascades were calculated using Monte Carlo techniques via the high energy transport code HET/KFA 1. Together with transport calculations for low energy neutrons by the MORSE-CG code the depth dependent spectra of primary and secondary protons and of secondary neutrons were derived. On the basis of these spectra and a set of evaluated experimental excitation functions for p-induced reactions and of theoretical ones for n-induced reactions, calculated by the code ALICE LIVERMORE 82, theoretical depth profiles for the production of stable and radioactive nuclides in the three thick targets were calculated. This report is a comprehensive survey on all those target/product combination for which both experimental and theoretical data are available. It provides the basis for a detailed discussion of the various production modes of residual nuclides and on the depth and size dependence of their production rates in thick stony targets, serving as a simulation of the galactic cosmic ray irradiation of meteoroids in space. On the other hand the comparison of the experimental and theoretical depth profiles validates the high energy transport calculations, making them a promissing tool for further model calculations of the interactions of cosmic rays with matter. (orig.)

The In Vitro Response of Tissue Stem Cells to Irradiation With Different Linear Energy Transfers

Energy Technology Data Exchange (ETDEWEB)

Nagle, Peter W.; Hosper, Nynke A. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Ploeg, Emily M. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Goethem, Marc-Jan van [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); KVI-Center for Advanced Radiation Research, University of Groningen, Groningen (Netherlands); Brandenburg, Sytze [KVI-Center for Advanced Radiation Research, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Chiu, Roland K. [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Coppes, Robert P., E-mail: r.p.coppes@umcg.nl [Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands); Department of Radiation Oncology, University of Groningen, University Medical Center Groningen, Groningen (Netherlands)

2016-05-01

Purpose: A reduction in the dose, irradiated volume, and sensitivity of, in particular, normal tissue stem cells is needed to advance radiation therapy. This could be obtained with the use of particles for radiation therapy. However, the radiation response of normal tissue stem cells is still an enigma. Therefore, in the present study, we developed a model to investigate the in vitro response of stem cells to particle irradiation. Methods and Materials: We used the immortalized human salivary gland (HSG) cell line resembling salivary gland (SG) cells to translate the radiation response in 2-dimensional (2D) to 3-dimensional (3D) conditions. This response was subsequently translated to the response of SG stem cells (SGSCs). Dispersed single cells were irradiated with photons or carbon ions at different linear energy transfers (LETs; 48.76 ± 2.16, 149.9 ± 10.8, and 189 ± 15 keV/μm). Subsequently, 2D or 3D clonogenicity was determined by counting the colonies or secondary stem cell-derived spheres in Matrigel. γH2AX immunostaining was used to assess DNA double strand break repair. Results: The 2D response of HSG cells showed a similar increase in dose response to increasing higher LET irradiation as other cell lines. The 3D response of HSG cells to increasing LET irradiation was reduced compared with the 2D response. Finally, the response of mouse SGSCs to photons was similar to the 3D response of HSG cells. The response to higher LET irradiation was reduced in the stem cells. Conclusions: Mouse SGSC radiosensitivity seems reduced at higher LET radiation compared with transformed HSG cells. The developed model to assess the radiation response of SGSCs offers novel possibilities to study the radiation response of normal tissue in vitro.

The In Vitro Response of Tissue Stem Cells to Irradiation With Different Linear Energy Transfers

International Nuclear Information System (INIS)

Nagle, Peter W.; Hosper, Nynke A.; Ploeg, Emily M.; Goethem, Marc-Jan van; Brandenburg, Sytze; Langendijk, Johannes A.; Chiu, Roland K.; Coppes, Robert P.

2016-01-01

Purpose: A reduction in the dose, irradiated volume, and sensitivity of, in particular, normal tissue stem cells is needed to advance radiation therapy. This could be obtained with the use of particles for radiation therapy. However, the radiation response of normal tissue stem cells is still an enigma. Therefore, in the present study, we developed a model to investigate the in vitro response of stem cells to particle irradiation. Methods and Materials: We used the immortalized human salivary gland (HSG) cell line resembling salivary gland (SG) cells to translate the radiation response in 2-dimensional (2D) to 3-dimensional (3D) conditions. This response was subsequently translated to the response of SG stem cells (SGSCs). Dispersed single cells were irradiated with photons or carbon ions at different linear energy transfers (LETs; 48.76 ± 2.16, 149.9 ± 10.8, and 189 ± 15 keV/μm). Subsequently, 2D or 3D clonogenicity was determined by counting the colonies or secondary stem cell-derived spheres in Matrigel. γH2AX immunostaining was used to assess DNA double strand break repair. Results: The 2D response of HSG cells showed a similar increase in dose response to increasing higher LET irradiation as other cell lines. The 3D response of HSG cells to increasing LET irradiation was reduced compared with the 2D response. Finally, the response of mouse SGSCs to photons was similar to the 3D response of HSG cells. The response to higher LET irradiation was reduced in the stem cells. Conclusions: Mouse SGSC radiosensitivity seems reduced at higher LET radiation compared with transformed HSG cells. The developed model to assess the radiation response of SGSCs offers novel possibilities to study the radiation response of normal tissue in vitro.

Detection of free radicals in γ-irradiated seasnail hard tissues by electron paramagnetic resonance

International Nuclear Information System (INIS)

Koeseoglu, Rahmi; Koeksal, Fevzi

2003-01-01

Gamma-irradiated seasnail (from family of Helix lukortium) hard tissues (CaCO 3 ) were investigated by electron paramagnetic resonance (EPR) at room temperature. The radicals produced by γ-irradiation in seasnail were attributed to orthorhombic C · O 2 - , freely rotating C · O 2 - , orthorhombic C · O 3 - , axial C · O 3 - , and axial C · O 3 3- free radicals. Unirradiated seasnail hard tissues also feature Mn 2+ ions in their EPR spectra. The hyperfine values were determined for the 13 C nucleus in the orthorhombic C · O 2 - and axial C · O 3 3- free radicals and for the manganese impurity ions. The g values of all the free radicals have been measured. The results were compared with the literature data for similar defects

The In Vitro Response of Tissue Stem Cells to Irradiation With Different Linear Energy Transfers

NARCIS (Netherlands)

Nagle, Peter W; Hosper, Nynke A; Ploeg, Emily M; van Goethem, Marc-Jan; Brandenburg, Sytze; Langendijk, Johannes A; Chiu, Roland K; Coppes, Robert P

2016-01-01

PURPOSE: A reduction in the dose, irradiated volume, and sensitivity of, in particular, normal tissue stem cells is needed to advance radiation therapy. This could be obtained with the use of particles for radiation therapy. However, the radiation response of normal tissue stem cells is still an

Anterior thigh composition measured using ultrasound imaging to quantify relative thickness of muscle and non-contractile tissue: a potential biomarker for musculoskeletal health

International Nuclear Information System (INIS)

Agyapong-Badu, Sandra; Warner, Martin; Samuel, Dinesh; Stokes, Maria; Narici, Marco; Cooper, Cyrus

2014-01-01

This study aimed to use ultrasound imaging to provide objective data on the effects of ageing and gender on relative thickness of quadriceps muscle and non-contractile tissue thickness (subcutaneous fat, SF, combined with perimuscular fascia). In 136 healthy males and females (aged 18–90 years n = 63 aged 18–35 years; n = 73 aged 65–90) images of the anterior thigh (dominant) were taken in relaxed supine using B-mode ultrasound imaging. Thickness of muscle, SF and perimuscular fascia were measured, and percentage thickness of total anterior thigh thickness calculated. Independent t-tests compared groups. Correlation between tissue thickness and BMI was examined using Pearson’s coefficient. Muscle thickness was: 39  ±  8 mm in young males, 29  ±  6 mm in females, 25  ±  4 mm in older males and 20  ±  5 mm in females. Percentage muscle to thigh thickness was greater in young participants (p = 0.001). Percentage SF and fascia was 17  ±  6% in young and 26  ±  8% in older males, 32  ±  7% in young and 44  ±  7% in older females. BMI was similar for age and correlated moderately with non-contractile tissue (r = 0.54; p < 0.001) and poorly with muscle (r = −0.01; p = 0.93). In conclusion, this novel application of ultrasound imaging as a simple and rapid means of assessing thigh composition (relative thickness of muscle and non-contractile tissue) may help inform health status, e.g. in older people at risk of frailty and loss of mobility, and aid monitoring effects of weight loss or gain, deconditioning and exercise. (paper)

On redistribution of alimentary vitamin E within irradiated rat tissues

International Nuclear Information System (INIS)

Paranich, A.V.; Chajkina, L.A.

1992-01-01

The data were presented concerning the content of lipopigments, vitamin E and malondialdehyde (MDA) in the brain and liver of rats. Excess vitamin E delivered with food was shown to be bound in tissues into complex with MDA. It was suggested that it was a labile form that reserves vitamin E. Irradiation of rats caused impairment of these complex and release of vitamin E, as well a decrease in the lipopigment fluorescence and increase in the MDA content

Oscillations of serum and tissue lipids in rats X-irradiated at different times of day

International Nuclear Information System (INIS)

Ahlers, I.; Ahlersova, E.; Toropila, M.; Smajda, B.; Praslicka, M.

1983-01-01

Young male Wistar rats (mean body mass 200 g) adapted to a 12:12 h light:dark regimen (7 a.m. to 7 p.m., 7 p.m. to 7 a.m.) were X-irradiated at 3-h intervals during one day with doses of 2.39 or 14.25 Gy and were killed 48 or 24 h afterwards. Nonesterified fatty acids were determined in their serum and white and brown adipose tissue, and triacylglycerols, phospholipids and total cholesterol in their serum and liver. The reaction of serum and tissue lipids during the day varied after both non-lethal and lethal irradiation. After non-lethal exposure, most of the curves, as regards their course, the presence of rhythm and their oscillation properties, concurred with the lipid indicator curves in the control series and indicated that the organism's response is dependent on the time of day. Circadian variation of serum and adipose tissue nonesterified fatty acid levels, the liver triacylglycerol concentration and the adrenal cholesterol concentration in lethally irradiated animals showed no significant dependence on the time of application of the stimulus. An analysis of circadian variation of the effectiveness of a stimulus facilitates understanding of the organism's reactivity better than a single examination in the morning. (author)

Corneal tissue welding with infrared laser irradiation after clear corneal incision.

Science.gov (United States)

Rasier, Rfat; Ozeren, Mediha; Artunay, Ozgür; Bahçecioğlu, Halil; Seçkin, Ismail; Kalaycoğlu, Hamit; Kurt, Adnan; Sennaroğlu, Alphan; Gülsoy, Murat

2010-09-01

The aim of this study was to investigate the potential of infrared lasers for corneal welding to seal corneal cuts done in an experimental animal model. Full-thickness corneal cuts on freshly enucleated bovine eyes were irradiated with infrared (809-nm diode, 980-nm diode, 1070-nm YLF, and 1980-nm Tm:YAP) lasers to get immediate laser welding. An 809-nm laser was used with the topical application of indocyanine green to enhance the photothermal interaction at the weld site. In total, 60 bovine eyes were used in this study; 40 eyes were used in the first part of the study for the determination of optimal welding parameters (15 eyes were excluded because of macroscopic carbonization, opacification, or corneal shrinkage; 2 eyes were used for control), and 20 eyes were used for further investigation of more promising lasers (YLF and Tm:YAP). Laser wavelength, irradiating power, exposure time, and spot size were the dose parameters, and optimal dose for immediate closure with minimal thermal damage was estimated through histological examination of welded samples. In the first part of the study, results showed that none of the applications was satisfactory. Full-thickness success rates were 28% (2 of 7) for 809-nm and for 980-nm diode lasers and 67% (2 of 3) for 1070-nm YLF and (4 of 6) for 1980-nm Tm:YAP lasers. In the second part of the study, YLF and Tm:YAP lasers were investigated with bigger sample size. Results were not conclusive but promising again. Five corneal incisions were full-thickness welded out of 10 corneas with 1070-nm laser, and 4 corneal incisions were partially welded out of 10 corneas with 1980-nm laser in the second part of the study. Results showed that noteworthy corneal welding could be obtained with 1070-nm YLF laser and 1980-nm Tm:YAP laser wavelengths. Furthermore, in vitro and in vivo studies will shed light on the potential usage of corneal laser welding technique.

Anatomic defects and behavioral abnormalities in rats irradiated in utero

International Nuclear Information System (INIS)

Kimler, B.F.; Norton, S.

1987-01-01

Pregnant rats were irradiated with 1.0 Gy whole-body doses of Cs-137 γ-rays on gestational days 11, 13, 15 and 17. Postnatal growth and preweaning behavior of the offspring were monitored prior to sacrifice or post-partuition day 28. Brain (sensory motor cortex) and pituitary tissues were processed for histological evaluation and morphometric analysis. The gestational days on which irradiation produced significant (rho<0.05) changes relative to controls are enclosed in parentheses, with the day(s) on which irradiation produced the maximum effect being underlined for the various parameters: body weight on post-partuition day 7, pituitary nuclear area, percent acidophils, and percent vacuolization, thickness of cortical layer I, II, III, IV, V, VI, and total cortical thickness; negative geotaxis, reflex suspension, continuous corridor activity, and gait. These data indicate that the critical period of development for radiation-induced alterations in post-natal growth, development, and behavior changes from the pituitary at gestational day 11 to the brain (primitive cortex) at days 13 to 17 with a peak of sensitivity at day 15

Biological effects of fast neutron irradiation on callus tissues of Tecoma stans Juss. and Ammi visnaga Lam

International Nuclear Information System (INIS)

Supniewska, J.H.; Dohnal, B.; Cebulska Wasilewska, A.; Huczkowski, J.

1982-01-01

Callus tissues of Tecoma stans Juss. and Ammi visnaga Lam. were subjected to fast neutron irradiation. Nine doses were applied within the range of 100 - 10.000 cGy. Small doses caused growth stimulation. Intermediate and high doses caused morphological changes, reduced growth and biosynthesis of biologically active substances (monoterpene alkaloids in T. stans, furanochromones in A. visnaga). In A. visnaga neutron irradiation considerably decreased the chlorophyll content in callus tissues. The radiosensitivity of A. visnaga at 50% growth reduction level was 1.5 times higher than that of the callus of T. stans. The recovery of the tissues takes place during a subculturing course. Three to 7 months after neutron exposure growth and biosynthesis reach the control level. (author)

Tissue breathing and topology of rats thymocytes surface under acute total γ-irradiation.

Science.gov (United States)

Nikitina, I A; Gritsuk, A I

2017-12-01

Assessment of the effect of single total γ irradiation to the parameters of mitochondrial oxidation and the topology of the thymocyte surface. The study was performed in sexually mature white outbreeding male rats divided into three groups: two experimental and one control. The states of energy metabolism were determined by the rate of oxygen consumption by the thymus tissues on endogenous substrates at the presence of 2,4 dinitrophenol, uncoupler of a tissue breathing (TB) and oxidative phosphorylation (OP) after a single total γ irradiation at a dose of 1.0 Gy at 3, 10, 40 and 60 days. The topology of thymus cells was assessed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). On the 3rd and 10th days after total gamma irradiation at a dose of 1.0 Gy, a significant decrease in respira tory activity was determined in thymus tissues on endogenous substrates. Simultaneously, on the 3rd day, pro nounced changes in the morphological parameters of thymocytes (height, volume, area of contact with the sub strate) and the topology of their surface were also observed. On the 10th day after irradiation, most of the morpho logical parameters of thymocytes, except for their volume, were characterized by restoration to normal. In the long term (on the 30th and 60th days after exposure), a gradual but not complete recovery of the respiratory activity of thymocytes was observed, accompanied by an increase in the degree of dissociation of TD and OP. The obtained data reflect and refine mechanisms of post radiation repair of lymphopoiesis, showing the presence of conjugated changes in the parameters of aerobic energy metabolism of thymocytes, morphology and topology of their surface. The synchronism of changes in the parameters under study is a reflection of the state of the cytoskeleton, the functional activity of which largely depends on the level and efficiency of mitochondrial oxidation. І. A. Nikitina, A. I. Gritsuk.

Morphometric changes of pulmonary tissues after 20 Gy external irradiation of rat chest

International Nuclear Information System (INIS)

Cao Zhenshan; Ye Changqing; Yuan Lizhen

1996-01-01

The changes in the main parameters of the lungs at different periods of early stage after local 20 Gy external irradiation of the lungs were measured with morphometric method. The results indicated that the walls of pulmonary arterioles and venules thickened and the vascular permeability index (area of vascular lumen/total area of blood vessel) decreased 7 days after irradiation (P 2 , r = -0.919), indicating that narrowing of the vascular lumen was the result of thickening of the vascular wall. Fifteen days after irradiation, the pulmonary alveolar wall thickened, the area of alveolar cavity decreased and the area of pulmonary interstitial space increased (P<0.01). Electron microscopic examination demonstrated profuse exudation surrounding the microvessels, obvious evacuation of pulmonary type-II cells and increase in cellular types and quantity of pulmonary tissues

Epicardial adipose tissue thickness and NGAL levels in women with polycystic ovary syndrome.

Science.gov (United States)

Sahin, Serap Baydur; Cure, Medine Cumhur; Ugurlu, Yavuz; Ergul, Elif; Gur, Emine Uslu; Alyildiz, Nese; Bostan, Mehmet

2014-02-16

Polycystic ovary syndrome (PCOS) is associated with an increased cardiovascular disease (CVD) risk and early atherosclerosis. Epicardial adipose tissue thickness (EATT) is clinically related to subclinical atherosclerosis. In the present study, considering the major role of neutrophil gelatinase-associated lipocalin (NGAL) which is an acute phase protein rapidly releasing upon inflammation and tissue injury, we aimed to evaluate NGAL levels and EATT in PCOS patients and assess their relationship with cardiometabolic factors. 64 patients with PCOS and 50 age- and body mass index-matched healthy controls were included in the study. We evaluated anthropometric, hormonal and metabolic parameters. EATT was measured by echocardiography above the free wall of the right ventricle. Serum NGAL and high-sensitive C- reactive protein (hsCRP) levels were measured by ELISA. Mean EATT was 0,38 +/-0,16 mm in the PCOS group and 0,34 +/-0,36 mm in the control group (p = 0,144). In the obese PCOS group (n = 44) EAT was thicker compared to the obese control group (n = 41) (p = 0.026). Mean NGAL levels of the patients with PCOS were 101,98 +/-21,53 pg/ml, while mean NGAL levels were 107,40 +/-26,44 pg/ml in the control group (p = 0,228). We found a significant positive correlation between EATT and age, BMI, waist circumference, fasting insulin, HOMA-IR, triglyceride and hsCRP levels in PCOS group. Thickness of the epicardial adipose tissue can be used to follow the risk of CVD development in obese PCOS cases. However serum NGAL levels do not differ in patients with PCOS and control group.

The effect of a single lethal X-irradiation exposure on the activity of lipoprotein lipase in the tissues of the rat

International Nuclear Information System (INIS)

Sedlakova, A.; Ahlers, I.; Praslicka, M.

1979-01-01

Wistar male rats, both fed and fasting for 16 h prior to irradiation, were exposed to a single lethal X-ray dose of 387 mC/kg (1500R). The activity of lipoprotein lipase in white adipose (epididymal) tissue and heart muscle and the concentration of serum triglycerides were determined at 1, 6, 24, 48, and 72 h after irradiation. In the early time periods, at 1 and 6 h after exposure, the activity of lipoprotein lipase decreased in adipose tissue and increased in heart muscle of the irradiated fed rats; in fasting rats it decreased in heart muscle at 1 h after exposure. The concentration of serum triglycerides increased at 1 h and decreased at 6 h after exposure in fed rats. In these rats, alterations in serum triglycerides correlated with changes in lipoprotein lipase activity in adipose tissue. Alterations observed at the later time periods were more dependent on the time interval between irradiation and the analysis. Lipoprotein lipase activity increased with time after irradiation up to the maximal values at 72 h. Fasting prior to and after irradiation substantially modified the response of animals to radiation. (author)

Tissue factor levels and the fibrinolytic system in thin and thick intraluminal thrombus and underlying walls of abdominal aortic aneurysms.

Science.gov (United States)

Siennicka, Aldona; Zuchowski, Marta; Kaczmarczyk, Mariusz; Cnotliwy, Miłosław; Clark, Jeremy Simon; Jastrzębska, Maria

2018-03-20

The hemostatic system cooperates with proteolytic degradation in processes allowing abdominal aortic aneurysm (AAA) formation. In previous studies, it has been suggested that aneurysm rupture depends on intraluminal thrombus (ILT) thickness, which varies across each individual aneurysm. We hypothesized that hemostatic components differentially accumulate in AAA tissue in relation to ILT thickness. Thick (A1) and thin (B1) segments of ILTs and aneurysm wall sections A (adjacent to A1) and B (adjacent to B1) from one aneurysm sac were taken from 35 patients undergoing elective repair. Factor levels were measured using enzyme-linked immunosorbent assay of protein extract. Tissue factor (TF) activities were significantly higher in thinner segments of AAA (B1 vs A1, P = .003; B vs A, P thick thrombus-covered wall segments (A) than in B, A1, and B1 (P = .015, P thick ILT (P = .021) and thick ILT (A1; P thick ILT (A1). However, no correlations were found at B sites, except for a correlation between plasmin and TF activities (r = 0.55; P = .004). These results suggest that higher TF activities are present in thinner AAA regions. These parameters and local fibrinolysis may be part of the processes leading to destruction of the aneurysm wall. Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

The Edinburgh experience of treating sarcomas of soft tissues and bone with neutron irradiation

International Nuclear Information System (INIS)

Duncan, W.; Arnott, S.J.; Jack, W.J.L.

1986-01-01

The experience of treating 30 patients with sarcomas of soft tissue and bone with d(15)+Be neutron irradiation is reported. The local control of measurable soft-tissue sarcomas was 38.5% (minimum follow-up 2 years), which is similar to that expected after photon therapy. The radiation morbidity was unacceptably high (50%). Bone tumours did not respond well; in only one out of nine was lasting local tumour control achieved. (author)

Rapid differentiation between gamma-irradiated and non irradiated potato tubers

International Nuclear Information System (INIS)

Jona, R.; Fronda, A.

1990-01-01

The use of gamma irradiation as commercial method for the preservation of fruits and vegetables calls for methods of differentiation between irradiated and non-irradiated foodstuffs. In a previous research, the polysaccharidic content of cell walls of irradiated tissue has been investigated, but it required rather long time to reach the result. A method devised to ascertain the vitality of cells has been applied to distinguish irradiated from non-irradiated potato tubers. 500 mg of tissue excised from tubers have been infiltrated with tetrazolium chloride 0.6% in phosphate buffer, pH 7.4. After 15 hrs of incubation at 30 0 C the treated tissues have been extracted with 95% ethanol whose O.D. has been measured at 530 mμ wavelength. The colour intensity of the alcohol allowed a very clearcut recognition of the irradiated tubers. (author)

Technical aspects in the obtention of tissue autoradiography using solid state nuclear track detectors

International Nuclear Information System (INIS)

Saint Martin, Gisela; Bernaola, Omar A.; Pozzi, Emiliano; Thorp, Silvia; Cabrini, Romulo L.; Tomasi, V.H.

2007-01-01

The autoradiography images produced in solid state nuclear track detectors by heavy ions originated in tissue provide relevant information about the spatial biodistribution of heavy particle emitters. Some preliminary aspects of the autoradiography technique are evaluated by two experiments which are in progress, using Lexan and CR 39 foils as solid state nuclear track detectors. In the first case, a tissue sample from rat kidney intoxicated with UO 2 (NO 3 ) 2 was embedded in paraffin and put in contact with a 1 mm thick CR 39 foil. After a two months exposure the foil was chemically developed resulting in scarce tracks. A satisfactory image cannot be obtained in these conditions. More prolonged exposure time is needed to obtain better images of such samples. The second experience consisted in the irradiation of fresh kidney tissue slices from healthy rats in contact with 250 μm thick Lexan foils, in a thermal neutrons flux. The irradiation was performed at the RA-3 facility of the Ezeiza Atomic Center (CAE). The contribution to image produced by tracks of particles due to reactions between neutrons and tissue elements (i.e. 14 N) was evaluated. The etching conditions should be modified in order to desensitize the detector material. (author) [es

Relationship between the Echocardiographic Epicardial Adipose Tissue Thickness and Serum Adiponectin in Patients with Angina

Science.gov (United States)

Yun, Kyeong Ho; Rhee, Sang Jae; Yoo, Nam Jin; Oh, Seok Kyu; Kim, Nam-Ho; Park, Do-Sim; Park, Hyun-Young

2009-01-01

Background It is still unknown whether increased cardiac adiposity is related to the risk factors of coronary artery disease (CAD). We measured epicaridal adopose tissue (EAT) and mediastinal adipose tissue (MAT) using echocardiography and examined their correlations with CAD and serum adiponectin. Methods One hundred fifty three patients who underwent elective coronary angiography for chest pain were measured cardiac adiposity by transthoracic echocardiography. The correlations of cardiac adipose tissue with the presence and severity of CAD and the serum adiponectin level were examined. Results EAT was thicker in patients with CAD (1.8±1.4 vs. 3.8±1.9 mm, phomocystein (r=0.289, p=0.001), fasting glucose (r=0.167, p=0.042), and fibrinogen (r=0.218, p=0.009), and a significant negative correlation with serum adiponectin (r=-0.194, p=0.016). EAT thickness (OR 11.53, 95% CI; 3.61-36.84, p<0.001) and low serum adiponectin (OR 2.88, 95% CI; 1.02-8.15, p=0.046) were independent predictors of obstructive CAD. However, MAT thickness was not associated with CAD. Conclusion EAT was associated with the severity and risk factors of CAD and correlated with serum adiponectin level. In contrast with EAT, MAT was not associated with CAD and adiponectin. PMID:20661336

Ultra-rapid microwave variable pressure-induced histoprocessing : Description of a new tissue processor

NARCIS (Netherlands)

Visinoni, F; Milios, J; Leong, ASY; Boon, ME; Kok, LP; Malcangi, F

We describe a new method of ultra-rapid histoprocessing that reduces the processing times for needle and endoscopic biopsies to 30 min and that of other surgical biopsy tissue blocks of up to 4 mm thick to 120 min. The MicroMED U R M Histoprocessor, which combines microwave irradiation with precise

Late nonstochastic changes in pig skin after β irradiation

International Nuclear Information System (INIS)

Peel, D.M.; Hopewell, J.W.; Wells, J.; Charles, M.W.

1985-01-01

Late radiation-induced changes in pig skin have been assessed following irradiation with β-rays from a 22.5- or 15-mm-diameter 90 Sr/ 90 Y source and a 19- or 9-mm-diameter 170 Tm source. Late damage, in terms of dermal atrophy, was assessed 2 years after irradiation from measurements of dermal thickness of 40-50% of the control value, occurred at a dose of approx. 40 Gy from the 22.5-mm source and approx. 75 Gy from the 15-mm source. In the case of 170 Tm the 19- and 9-mm sources produced similar degrees of atrophy at equal doses. Maximum atrophy occurred at approx. 70 Gy, when the dermis was approx. 70% of the thickness of normal skin. Significant late tissue atrophy was seen at doses, from both types of radiation, which only produced minimal erythema in the early reaction. Such late reactions need to be taken into account when revised radiological protection criteria are proposed for skin

Variations in epidermal cytochrome oxidase activity after local irradiation

International Nuclear Information System (INIS)

Itoiz, M.E.; Rey, B.M. de; Cabrini, R.L.

1982-01-01

Cytochrome oxidase activity was evaluated histochemically as an index of mitochondrial damage after local irradiation with X-rays. It was determined by microphotometry on the tail skin of newly born Wistar rats four days after irradiation with doses ranging from 2 to 16krad. The enzyme activity of the whole epidermis increased after irradiation, the increases being related to the increase in thickness of the epithelium which was observed as a response to irradiation injury. Within the dose range tested, the enzyme concentration (expressed per unit volume of tissue) decreased in relation to the dose applied. At the electron microscopy level, the cytochemical demonstration of cytochrome oxidase revealed an irregular reaction over the cristae, intramitochondrial vacuolization and partial homogenization of the matrix. Positive membrane fragments were seen around lipid droplets. This reaction confirms the mitochondrial origin of these previously observed radiation-induced vacuoles. (author)

Effect of x-ray irradiation on maize inbred line B73 tissue cultures and regenerated plants

International Nuclear Information System (INIS)

Wang, A.S.; Cheng, D.S.K.; Milcic, J.B.; Yang, T.C.

1988-01-01

In order to enhance variation induced by the tissue culture process and to obtain agronomically desirable mutants, friable embryogenic tissue cultures of maize (Zea mays L.) inbred line B73 were x-ray irradiated with 11 doses [0-8.4 kilorads (kR)]. Reductions in callus growth rate and embryogenic callus formation occurred with increasing x-ray doses 20 d and 3 months after irradiation. Callus irradiated with 0.8 kR showed a significant increase in growth rate and a 20% increase in embryogenic callus 9 months after irradiation. A total of 230 R 0 plants were regenerated for evaluation. Pollen fertility and seed set of R 0 plants decreased with increasing x-ray dosage. Days to anthesis and plant height of R 0 plants varied among x-ray treatments but were generally reduced with higher dosages. The number of chromosomal aberrations increased with x-ray dosage. The R 1 seeds taken from R 0 plants were also grown and tested for mutant segregation. Plants regenerated from irradiated calli had a two- to 10-fold increase in mutations over plants regenerated from unirradiated control callus. Germination frequency of seeds from R 0 plants decreased with increasing x-ray dosage. Although chlorophyll mutants were most frequently observed, a number of vigorous plants with earlier anthesis date were also recovered

Up-regulation of calreticulin in mouse liver tissues after long-term irradiation with low-dose-rate gamma rays.

Science.gov (United States)

Yi, Lan; Hu, Nan; Yin, Jie; Sun, Jing; Mu, Hongxiang; Dai, Keren; Ding, Dexin

2017-01-01

The biological effects of low-dose or low-dose-rate ionizing radiation on normal tissues has attracted attention. Based on previous research, we observed the morphology of liver tissues of C57BL/6J mice that received irradiation dose rates increased. Additionally, differential protein expression in liver tissues was analyzed using a proteomics approach. Compared with the matched group in the 2D gel analysis of the irradiated groups, 69 proteins had ≥ 1.5-fold changes in expression. Twenty-three proteins were selected based on ≥2.5-fold change in expression, and 22 of them were meaningful for bioinformatics and protein fingerprinting analysis. These molecules were relevant to cytoskeleton processes, cell metabolism, biological defense, mitochondrial damage, detoxification and tumorigenesis. The results from real-time PCR and western blot (WB) analyses showed that calreticulin (CRT) was up-regulated in the irradiated groups, which indicates that CRT may be relevant to stress reactions when mouse livers are exposed to low-dose irradiation and that low-dose-rate ionizing radiation may pose a cancer risk. The CRT protein can be a potential candidate for low-dose or low-dose-rate ionizing radiation early-warning biomarkers. However, the underlying mechanism requires further investigation.

Chitosan adhesive for laser tissue repair

Science.gov (United States)

Lauto, A.; Stoodley, M.; Avolio, A.; Foster, L. J. R.

2006-02-01

Background. Laser tissue repair usually relies on haemoderivate solders, based on serum albumin. These solders have intrinsic limitations that impair their widespread use, such as limited repair strength, high solubility, brittleness and viral transmission. Furthermore, the solder activation temperature (65-70 °C) can induce significant damage to tissue. In this study, a new laser-activated biomaterial for tissue repair was developed and tested in vitro and in vivo to overcome some of the shortcomings of traditional solders. Materials and Methods. Flexible and insoluble strips of chitosan adhesive (surface area ~34 mm2, thickness ~20 μm) were developed and bonded on sheep intestine with a laser fluence and irradiance of 52 +/- 2 J/cm2 and ~15 W/cm2 respectively. The temperature between tissue and adhesive was measured using small thermocouples. The strength of repaired tissue was tested by a calibrated tensiometer. The adhesive was also bonded in vivo to the sciatic nerve of rats to assess the thermal damage induced by the laser (fluence = 65 +/- 11 J/cm2, irradiance = 15 W/cm2) four days post-operatively. Results. Chitosan adhesives successfully repaired intestine tissue, achieving a repair strength of 0.50 +/- 0.15 N (shear stress = 14.7 +/- 4.7 KPa, n=30) at a temperature of 60-65 °C. The laser caused demyelination of axons at the operated site; nevertheless, the myelinated axons retained their normal morphology proximally and distally.

Does Three-Dimensional External Beam Partial Breast Irradiation Spare Lung Tissue Compared With Standard Whole Breast Irradiation?

International Nuclear Information System (INIS)

Jain, Anudh K.; Vallow, Laura A.; Gale, Ashley A.; Buskirk, Steven J.

2009-01-01

Purpose: To determine whether three-dimensional conformal partial breast irradiation (3D-PBI) spares lung tissue compared with whole breast irradiation (WBI) and to include the biologically equivalent dose (BED) to account for differences in fractionation. Methods and Materials: Radiotherapy treatment plans were devised for WBI and 3D-PBI for 25 consecutive patients randomized on the NSABP B-39/RTOG 0413 protocol at Mayo Clinic in Jacksonville, Florida. WBI plans were for 50 Gy in 25 fractions, and 3D-PBI plans were for 38.5 Gy in 10 fractions. Volume of ipsilateral lung receiving 2.5, 5, 10, and 20 Gy was recorded for each plan. The linear quadratic equation was used to calculate the corresponding dose delivered in 10 fractions and volume of ipsilateral lung receiving these doses was recorded for PBI plans. Ipsilateral mean lung dose was recorded for each plan and converted to BED. Results: There was a significant decrease in volume of lung receiving 20 Gy with PBI (median, 4.4% vs. 7.5%; p 3 vs 4.85 Gy 3 , p = 0.07). PBI plans exposed more lung to 2.5 and 5 Gy. Conclusions: 3D-PBI exposes greater volumes of lung tissue to low doses of radiation and spares the amount of lung receiving higher doses when compared with WBI.

Beam Attenuators and the Risk of Unrecognized Large-Fraction Irradiation of Critical Tissues

International Nuclear Information System (INIS)

Luka, S.; Marks, J.E.

2015-01-01

The use of radiation beam attenuators led to radiation injury of the spinal cord in one patient and of the peripheral nerve in another due to unsuspected large-fraction irradiation. The anatomic distribution of radiation dose was reconstructed in the sagittal plane for the patient who developed radiation myelopathy and in the axial plane for the patient who developed peripheral neuropathy. The actual dose delivered to the injured structure in each patient was taken from the dose distribution and recorded along with the time, number of fractions, and dose per fraction. The patient who developed radiation myelopathy received a total of 46.5 Gy in twenty-three 2.1 Gy fractions in 31 days to the upper cervical spinal cord where the thickness of the neck was less than the central axis thickness due to cervical lordosis and absence of a posterior compensating filter. The patient who developed peripheral neuropathy received 55 Gy in twenty-five 2.2 Gy fractions in 50 days to the femoral nerve using bolus over the groins and an anterior one-half value layer Cerrobend pelvic block to bias the dose anteriorly. Compensating filters and other beam attenuators should be used with caution because they may result in unsuspected large-fraction irradiation and total doses of radiation that exceed the tolerance of critical structures.

Beam Attenuators and the Risk of Unrecognized Large-Fraction Irradiation of Critical Tissues

Energy Technology Data Exchange (ETDEWEB)

Luka, S.; Marks, J.E.

2015-01-15

The use of radiation beam attenuators led to radiation injury of the spinal cord in one patient and of the peripheral nerve in another due to unsuspected large-fraction irradiation. The anatomic distribution of radiation dose was reconstructed in the sagittal plane for the patient who developed radiation myelopathy and in the axial plane for the patient who developed peripheral neuropathy. The actual dose delivered to the injured structure in each patient was taken from the dose distribution and recorded along with the time, number of fractions, and dose per fraction. The patient who developed radiation myelopathy received a total of 46.5 Gy in twenty-three 2.1 Gy fractions in 31 days to the upper cervical spinal cord where the thickness of the neck was less than the central axis thickness due to cervical lordosis and absence of a posterior compensating filter. The patient who developed peripheral neuropathy received 55 Gy in twenty-five 2.2 Gy fractions in 50 days to the femoral nerve using bolus over the groins and an anterior one-half value layer Cerrobend pelvic block to bias the dose anteriorly. Compensating filters and other beam attenuators should be used with caution because they may result in unsuspected large-fraction irradiation and total doses of radiation that exceed the tolerance of critical structures.

Carotid intima-media thickness in patients with head and neck irradiation for the treatment of nasopharyngeal carcinoma

Energy Technology Data Exchange (ETDEWEB)

So, N.M.C.; Lam, W.W.M.; Chook, P.; Woo, K.S.; Liu, K.H.; Leung, S.F.; Wong, K.S.; Metreweli, C

2002-07-01

AIM: Intima-media thickness (IMT) has been shown to be useful in the evaluation and monitoring of carotid artery atherosclerosis in patients at risk of cardiovascular events. In this study, we aimed to examine the IMT in patients with nasopharyngeal carcinoma (NPC) who received irradiation to the carotid arteries during radiotherapy, and compared them with a control group. MATERIALS AND METHODS: Fifty-one NPC patients (aged between 39 and 69 years) and a group of 51 age-and sex-matched controls were studied by ultrasound. The IMT at the far wall of the common carotid artery was measured three times and the average value taken in each subject. The IMT of both groups were compared. Risk factors for IMT thickness, including hypertension, smoking, hyperglycaemia, hypercholesterolaemia, history of cerebrovascular accidents and cardiovascular disease, were also studied. RESULTS: The mean carotid IMT of patients in the NPC group (2.2+/-1.5 mm) was statistically greater than that in normal controls (0.7+/-0.15 mm) (P < 0.05). There was no statistically significant difference between the IMT in the right and left common carotid arteries within each group of patients. CONCLUSION: The findings suggest that patients with irradiation have increased arterial IMT. As they are asymptomatic the clinical relevance is not clear. So, N.M.C. et al. (2002)

Carotid intima-media thickness in patients with head and neck irradiation for the treatment of nasopharyngeal carcinoma

International Nuclear Information System (INIS)

So, N.M.C.; Lam, W.W.M.; Chook, P.; Woo, K.S.; Liu, K.H.; Leung, S.F.; Wong, K.S.; Metreweli, C.

2002-01-01

AIM: Intima-media thickness (IMT) has been shown to be useful in the evaluation and monitoring of carotid artery atherosclerosis in patients at risk of cardiovascular events. In this study, we aimed to examine the IMT in patients with nasopharyngeal carcinoma (NPC) who received irradiation to the carotid arteries during radiotherapy, and compared them with a control group. MATERIALS AND METHODS: Fifty-one NPC patients (aged between 39 and 69 years) and a group of 51 age-and sex-matched controls were studied by ultrasound. The IMT at the far wall of the common carotid artery was measured three times and the average value taken in each subject. The IMT of both groups were compared. Risk factors for IMT thickness, including hypertension, smoking, hyperglycaemia, hypercholesterolaemia, history of cerebrovascular accidents and cardiovascular disease, were also studied. RESULTS: The mean carotid IMT of patients in the NPC group (2.2+/-1.5 mm) was statistically greater than that in normal controls (0.7+/-0.15 mm) (P < 0.05). There was no statistically significant difference between the IMT in the right and left common carotid arteries within each group of patients. CONCLUSION: The findings suggest that patients with irradiation have increased arterial IMT. As they are asymptomatic the clinical relevance is not clear. So, N.M.C. et al. (2002)

Relationship between X-ray irradiation and chromosomal damage in bone marrow tissue of mice

International Nuclear Information System (INIS)

Chaubey, R.C.; George, K.P.; Sundaram, K.

1976-01-01

X-ray induced chromosomal damage in bone-marrow tissue of male mice was studied using micronucleus technique. Dose response relationship was evaluated. Male Swiss mice received whole body x-ray irradiation at different doses from 25-1000 rads. Animals were sacrificed at the end of 24 hours, bone-marrow smears were made and stained in May-Grunwald-Giemsa. The preparatians were scored for the following types of aberrations: micronuclei in young erythocytes-polychromatic cells and in the mature erythrocytes-normechromatic cells. A dose dependent increase in the frequency of micronuclei in polychromatic cells up to a dose of 100 rads was observed. In addition the effect of post-irradiation duration on the frequency of micronuclei in polychromatic and normochromatic cells were studied. Male Swiss mice were exposed to 200 rads x-rays and were then sacrificed at different time intervals after irradiation and bone-marrow preparations were made and scored. Maximum polychromatic cells with micronuclei were observed in 24 hours post-irradiated animals, thereafter a decrease in the frequency of polychromatic cells with micronuclei was observed in 40 hours post irradiated animals. (author

Kinetics of [14C-5] 8-methoxypsoralen uptake by UVA irradiated and non-irradiated rabbit eye tissues

International Nuclear Information System (INIS)

Malinin, G.I.; Glew, W.B.; Roberts, W.P.; Nigra, T.P.

1981-01-01

Total 8-methoxypsoralen (8-MOP) in intact and UVA irradiated rabbit eye tissues and its unaltered fraction in aqueous and eye lenses were determined over the 24 hours after i.v. injection of [ 14 C-5] and carrier 8-MOP at the concentration of 50 microCi and 5 mg/kg. No 8-MOP was detected at the end of 24 hours in intact and irradiated aqueous, vitreous and retina in contrast to one hour when the respective levels were congruent to 220, greater than 0 and congruent to 160 ng/g. Eye-plasma drug concentration ratios were less than 0.5 initially, but increased thereafter. While the average lens 8-MOP levels of congruent to 140 ng/g remained unchanged for 24 hours, no unaltered drug was detected beyond eight hours. Measurable amounts of label at the end of 24 hours also persisted in the cornea, iris, sclera and conjunctiva

Functional state of perfused liver tissue in X-ray irradiated rats

Energy Technology Data Exchange (ETDEWEB)

Borovikova, G.V.; Dokshina, G.A.; Lapteva, T.A. (Tomskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Biologii i Biofiziki)

1981-01-01

The results of studying the functional state of perfused liver tissue isolated from rats after irradiation in the 18.06x10/sup -2/ Kl/kg dose, which has been estimated by transamination process rate catalized alanine-(KF 2.6x1.2, ALT and aspartate by aminotransferases (KF 2.6x1.1, ACT), gluconeogenesis and urea production intensity presented. When comparing the results obtained on the perfused liver deprived of homeostatic body effects it has been found that the liver isolated from the body for the first 24 hours of the radiation sickness development possesses a higher radiation activity which manifests itself in intensification of the processes of gluconeogenesis and transamination with substrate addition. The third 24 hours upon irradiation in the isolated liver the intensity of the gluconeogenesis and transamination processes is attenuated.

Pre-irradiation of tissue culture flasks leads to diminished stem and progenitor cell production in long-term bone marrow cultures

International Nuclear Information System (INIS)

Rooney, P.; Wright, E.G.

1993-01-01

Empty plastic tissue culture flasks were exposed to X-irradiation doses of 0.3-10.0 Gy, prior to the establishment of long-term bone marrow cultures. During the course of a 10 week culture period, all irradiated plastic flasks exhibited a dramatic decrease in the number of both haemopoietic stem cells and myeloid progenitor cells, in the non-adherent layer, when compared with controls. This decrease was not due to a decrease in the number of non-adherent cells produced. Histological examination of non-adherent cells showed an increase in mature granulocytic cells with few blast cells. Morphologically, the adherent layers of irradiated flasks demonstrated a delay in appearance or absence of fat cell production. X-irradiation of glass tissue culture flasks had no deleterious effect. (author)

The dosimetry of cobalt-60 γ-ray total body irradiation before bone marrow transplantation

International Nuclear Information System (INIS)

Dong Fan; Zhang Guiru

1989-11-01

The dosimetric considerations of using conventional cobalt-60 unit total body irradiation (TBI) are presented. By extending the source-to-midplane distance (SMD) to 346 cm, a 92 x 98 cm 2 rectangular field with diagonal dimension 134 cm was obtained. The results from the phantom measurements showed: (1) the effective field corresponding to an average-size patient is 25 x 25 cm 2 , and a method for estimating the effective field of human body is given; (2) the midplane doses are consistently higher than those of surfaces, but the dose ratio of midplane to surface decreases as the body thickness increases, and a significant negative correlation is existed between the dose ratio and thickness, thus a linear regression line is fitted; (3) the anterior-posterior (AP) or AP + bilateral irradiation will yield a more uniform dose distribution in the whole body than the bilateral irradiation; (4) the dose uniformity can apparently be improved by the tissue compensation, for which the technique is described

Aluminium and Gamma Irradiation Induced Oxidative Damage in Brain Tissue of Male Rats - Protective Role of Ferulic Acid

International Nuclear Information System (INIS)

Mansour, S.Z.; Hanafi, N.; Noaman, E.

2011-01-01

The current study was carried out to investigate the potential role of ferulic acid (FA) against Aluminium chloride (AlCl 3 ), γ- radiation either alone or combination induced oxidative stress in brain tissue of Wistar rats. The period of the experiment was eight weeks. Animals were administrated by aluminium chloride at a dose of 8.5 mg/kg/day and exposed to a single dose (4 Gy) of γ-radiation. FA was administered orally (50 mg/Kg body weight)/day. Histopathological observations and myeloid protein distribution were recorded in brain tissue. Induction of oxidative stress was recorded after all exposures. Brain tissue of AlCl 3 and γ- irradiation treatments either alone or combined revealed many altered changes and myeloid protein distribution. Also a decrease in serotonin concentration was recorded. An increase in Malonaldialdahyde (MDA) and acetylcholinesterase activity and percentage of saturated fatty acids in plasma and brain tissue was recorded. Reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) in blood and brain showed a significant decrease. Treatment of AlCl 3 loaded animals by FA showed simple atrophy as shrunken morphology saw in amyotrophic lateral sclerosis and a decrease in myeloid protein deposition. FA treatment of AlCl 3 loaded or irradiated animals represented a significant increase in serotonin concentration and ameliorated affects on oxidative stress markers, acetylcholinesterase activity and percentage of saturated fatty acids in plasma and brain tissue. In conclusion FA has a role in reducing the oxidative stress of AlCl 3 and γ- irradiation on brain tissue of rats

On fibrinolytic phenomenon in the cancerous tissue of cervical carcinoma with special reference to irradiation changes

International Nuclear Information System (INIS)

Nakamura, Kazuyoshi

1978-01-01

In a study undertaken to investigate alterations of fibrinolytic enzymes in cancerous tissue of the cervix under radiotherapy, specimens were taken from malignant tissues of cervical cancer patients during irradiation therapy with Linac x-ray at 1000, 2000 and 3000 rads and were subsequently assayed for fibrinolytic enzyme activities using the fibrin plate method. No plasmin activity was demonstrable in the normal mucosa of the uterine cervix. Cancerous tissue of the uterine cervix also showed no demonstrable plasmin activity. The malignant tissue, as compared to the normal mucosa of the cervix, was found to have a lower activator activity, a higher proactivator activity and lower activities of both antiplasmin inhibitors. During radiotherapy for cervical cancer, plasmin activity was demonstrable in the cancerous tissue and in patients with malignant neoplasm, demonstrating that plasmin activity increased as the radiation dose was increased. A relationship seemed to exist between morphological changes and alterations in the fibrinolytic system of cancerous tissue of the cervix. From these findings it seems that the altered fibrinolytic enzyme system in cancerous tissue may have a close relationship with the growth and development of malignancy and may also have an important role in the occurrence of metastasis. There were some cases, in which an abnormal increase in activator activity occurred during irradiation therapy, leading to the death of the patients. This fact points to the possibility that activator activity might provide a useful index for evaluating the prognosis of cervical cancer. (author)

MR characterization of post-irradiation soft tissue edema

International Nuclear Information System (INIS)

Richardson, M.L.; Zink-Brody, G.C.; Patten, R.M.; Koh Wuijin; Conrad, E.U.

1996-01-01

Objective. Radiation therapy is often used to treat bone und soft tissue neoplasms, and commonly results in soft tissue edema in the radiation field. However, the time course, distribution and degree of this edema have not been well characterized. Our study was carried out to better define these features of the edema seen following neutron and photon radiation therapy. Results. In general, soft tissue signal intensity in the radiation field initially increased over time, peaking at about 6 months for neutron-treated patients and at about 12-18 months for photon-treated patients. Signal intensity then decreased slowly over time. However, at the end of the follow-up period, signal intensity remained elevated for most patients in both groups. Signal intensity in a particular tissue was greater and tended to persist longer on STIR sequences than on T2-weighted sequences. Survival analysis of signal intensity demonstrated much longer edema survival times for neutron-treated patients than for photon-treated patients. Signal intensity increase in the intramuscular septa persisted for much longer than for fat or muscle. A mild increase in size was noted in the subcutaneous fat and intramuscular septa. Muscle, on the other hand, showed a decrease in size following treatment. This was mild for the photon-treated group and more marked for the neutron-treated group. Conclusions. There is a relatively wide variation in the duration and degree of post-irradiation edema in soft tissues. This edema seems to persist longer in the intramuscular septa than in fat or muscle. Although the duration of follow-up was limited, our study suggests that this edema resolves in roughly half the photon-treated patients within 2-3 years post-treatment and in less than 20% of neutron-treated patients by 3-4 years post-treatment. Muscle atrophy was seen in both photon- and neutron-treated patients, but was more severe in the neutron-treated group. (orig./vhe). With 4 figs

The concentration of oxygen dissolved in tissues at the time of irradiation as a factor in radiotherapy

International Nuclear Information System (INIS)

Gray, L.H.; Conger, A.D.; Ebert, M.; Hornsey, S.; Scott, O.C.A.

1984-01-01

The sensitivity of tumour cells to X rays has been shown to be about three times as great when irradiated in a well-oxygenated medium as under anoxic conditions. The manner in which sensitivity depends on oxygen tension closely resembles that found by other workers for plant and insect tissues. The sensitivity of the tumour cells to fast neutron radiation is only slightly affected by oxygen tension. Consideration is given to the supply of oxygen to tissues as a factor in radiotherapy, and it is concluded on the basis of existing knowledge that in certain circumstances the effectiveness of X-ray treatment might be increased if the patient were breathing oxygen at the time of irradiation

Propagation characteristics of laser-induced stress wave in deep tissue for gene transfer

International Nuclear Information System (INIS)

Ando, Takahiro; Sato, Shunichi; Takano, Shinta; Ashida, Hiroshi; Obara, Minoru

2009-01-01

Propagation characteristics of laser-induced stress waves (LISWs) in tissue and their correlation with properties of gene transfection were investigated for targeted deep-tissue gene therapy. LISWs were generated by irradiating a laser-absorbing material with 532-nm Q-switched Nd:YAG laser pulses; a transparent plastic sheet was attached on the absorbing material for plasma confinement. Temporal pressure profiles of LISWs that were propagated through different thickness tissues were measured with a needle-type hydrophone and propagation of LISWs in water was visualized by shadowgraph technique. The measurements showed that at a laser fluence of 1.2 J/cm 2 with a laser spot diameter of 3 mm, flat wavefront was maintained for up to 5 mm in depth and peak pressure P decreased with increasing tissue thickness d; P was proportional to d -0.54 . Rat dorsal skin was injected with plasmid DNA coding for reporter gene, on which different numbers of excised skin(s) was/were placed, and LISWs were applied from the top of the skins. Efficient gene expression was observed in the skin under the 3 mm thick stacked skins, suggesting that deep-located tissue such as muscle can be transfected by transcutaneous application of LISWs.

Immunocytochemistry of formalin-fixed human brain tissues: microwave irradiation of free-floating sections.

Science.gov (United States)

Shiurba, R A; Spooner, E T; Ishiguro, K; Takahashi, M; Yoshida, R; Wheelock, T R; Imahori, K; Cataldo, A M; Nixon, R A

1998-01-01

antigens. Theory and practice of microwave antigen retrieval are covered extensively in the handbook Microwave Cookbook for Microscopists. A concise overview of microwave methods in the neurosciences has been published, and clinical applications have been reviewed. In this context, it should be noted that fresh tissues may be stabilized for immunocytochemistry by reversible, non-chemical binding processes such as cryosectioning after microwave treatment and freeze-drying. Thus, it may be possible to enhance immunostaining for some antigens by microwave irradiation of unfixed as well as fixed specimens. Parameters to be optimized for microwave retrieval of specific antigens include temperature, irradiation time, tissue buffer composition, salt concentration, and pH. Temperature, irradiation time, and pH are key variables. With this in mind, an optimal method was developed for retrieval of a wide variety of antigens in human brain tissues. Typical microwave protocols employ elevated temperatures that may reach 100 degrees C, where denaturation causes irreversible uncoiling and disruption of protein secondary and tertiary structures. Under these conditions, stable covalent bonds securing methylene crosslinks between polypeptides remain intact, but more reactive links formed by Schiff bases may be hydrolyzed. Resultant conformational changes presumably expose buried loops of continuous amino acids and protruding regions, increasing accessibility of their epitopes. Protein denaturation seems to be a reasonable explanation for the effects of microwaves on antigen retrieval. This idea is supported by the observation that denaturing solutions such as 6 M urea increase immunoreactivity of some antigens. Still, the molecular basis of these effects remains unresolved, in part due to the complex chemistry of formaldehyde reactions with tissue constituents. Indeed, some methylene bridges between similar groups such as NH2 and NH may be hydrolyzed by washing fixed tissues in distilled

Experimental study on active specific immunotherapy utilizing the immunotherapy utilizing the immune reaction of low-dose irradiated tumor tissue, 3

International Nuclear Information System (INIS)

Ogawa, Yasuhiro; Imanaka, Kazufumi; Gose, Kyuhei; Imajo, Yoshinari; Kimura, Shuji

1982-01-01

We have already demonstrated the remarkable effect of the active specific immunotherapy utilizing tumor cells and infiltrating lymphocytes prepared from a low-dose irradiated tumor tissue after cytoreductive radiotherapy. In the present study, the active specific immunotherapy using the tumor cells and infiltrating lymphocytes which were cryopreserved at -196 0 C in liquid nitrogen was investigated in female C3H/He mice inoculated MM46 tumor. Irradiation with the dose of 3,000 rads was performed on the sixth day. The tumor cells and lymphocytes which were separated from 2,000 rads-irradiated tumor tissue were frozen by the program freezer to be preserved at -196 0 C for two months and were thawed to inject into the tumor-bearing mice on the thirteenth day. Anti-tumor effect was evaluated by the regression of the tumor and survival curves. The remarkable regression of the tumor (p < 0.01) and significant elongation of the survival period (p < 0.1) were observed in the group which received the active specific immunotherapy using the cryopreserved tumor cells and lymphocytes as well as the group using the fresh tumor cells and lymphocytes prepared from a low-dose irradiated tumor tissue. (author)

The functional state of perfused liver tissue in X-ray irradiated rats

International Nuclear Information System (INIS)

Borovikova, G.V.; Dokshina, G.A.; Lapteva, T.A.

1981-01-01

The results of studying the functional state of perfused liver tissue isolated from rates after irradiation in the 18.06x10 - 2 Kl/kg dose, which has been estimated by transamination process rate catalized alanine-(KF 2.6x1.2, ALT and aspartate by aminotransferases (KF 2.6x1.1, ACT), gluconeogenesis and urea production intensity presented. When comparing the results obtained on the perfused liver deprived of homeostatic body effects it has been found that the liver isolated from the body for the first 24 hours of the radiation sickness development possesses a higher radiation activity which manifests itself in intensification of the processes of gluconeogenesis and transamination with substrate addition. The third 24 hours upon irradiation in the isolated liver the intensity of the gluconeogenesis and transamination processes is attenuated

An ultrasonographic evaluation of skin thickness in breast cancer patients after postmastectomy radiation therapy

International Nuclear Information System (INIS)

Wong, Sharon; Kaur, Amarjit; Back, Michael; Lee, Khai Mun; Baggarley, Shaun; Lu, Jiade Jay

2011-01-01

To determine the usefulness of ultrasonography in the assessment of post radiotherapy skin changes in postmastectomy breast cancer patients. Patients treated for postmastectomy radiotherapy in National University Hospital (NUH) and Tan Tock Seng Hospital (TTSH), Singapore between January 2004- December 2005 was recruited retrospectively. Ultrasound scan was performed on these Asian patients who had been treated to a total dose of 46-50 Gy with 1 cm bolus placed on the skin. The ultrasound scans were performed blinded to the RTOG scores, and the skin thickness of the individually marked points on the irradiated chest wall was compared to the corresponding points on the non-irradiated breast. The mean total skin thickness inclusive of the epidermis and the dermis of the right irradiated chest wall was 0.1712 mm (± 0.03392 mm) compared with the contra-lateral non-irradiated breast which was 0.1845 mm (± 0.04089 mm; p = 0.007). The left irradiated chest wall had a mean skin thickness of 0.1764 mm (± 0.03184 mm) compared with the right non-irradiated breast which was 0.1835 mm (± 0.02584 mm; p = 0.025). These independent t-tests produced a significant difference of reduced skin thickness on the right irradiated chest wall, p = 0.007 (p < 0.05) and left irradiated chest wall p = 0.025 (p < 0.025) in comparison to the non-irradiated skin thickness investigating chronic skin reactions. Patients with grade 2 acute skin toxicity presented with thinner skin as compared to patients with grade 1 (p = 0.006). This study has shown that there is a statistically significant difference between the skin thicknesses of the irradiated chest wall and the contra-lateral non-irradiated breast and a predisposition to chronic reactions was found in patients with acute RTOG scoring of grade1 and grade 2

Characterization of 150μm thick epitaxial silicon detectors from different producers after proton irradiation

International Nuclear Information System (INIS)

Hoedlmoser, H.; Moll, M.; Haerkoenen, J.; Kronberger, M.; Trummer, J.; Rodeghiero, P.

2007-01-01

Epitaxial (EPI) silicon has recently been investigated for the development of radiation tolerant detectors for future high-luminosity HEP experiments. A study of 150μm thick EPI silicon diodes irradiated with 24GeV/c protons up to a fluence of 3x10 15 p/cm 2 has been performed by means of Charge Collection Efficiency (CCE) measurements, investigations with the Transient Current Technique (TCT) and standard CV/IV characterizations. The aim of the work was to investigate the impact of radiation damage as well as the influence of the wafer processing on the material performance by comparing diodes from different manufacturers. The changes of CCE, full depletion voltage and leakage current as a function of fluence are reported. While the generation of leakage current due to irradiation is similar in all investigated series of detectors, a difference in the effective doping concentration can be observed after irradiation. In the CCE measurements an anomalous drop in performance was found even for diodes exposed to very low fluences (5x10 13 p/cm 2 ) in all measured series. This result was confirmed for one series of diodes in TCT measurements with an infrared laser. TCT measurements with a red laser showed no type inversion up to fluences of 3x10 15 p/cm 2 for n-type devices whereas p-type diodes undergo type inversion from p- to n-type for fluences higher than ∼2x10 14 p/cm 2

Stress Analysis of Transcatheter Aortic Valve Leaflets Under Dynamic Loading: Effect of Reduced Tissue Thickness.

Science.gov (United States)

Abbasi, Mostafa; Azadani, Ali N

2017-07-01

In order to accommodate transcatheter valves to miniaturized catheters, the leaflet thickness must be reduced to a value which is typically less than that of surgical bioprostheses. The study aim was to use finite-element simulations to determine the impact of the thickness reduction on stress and strain distribution. A 23 mm transcatheter aortic valve (TAV) was modelled based on the Edwards SAPIEN XT (Edwards Lifesciences, Irvine, CA, USA). Finite-element (FE) analysis was performed using the ABAQUS/Explicit solver. An ensemble-averaged transvalvular pressure waveform measured from in-vitro tests conducted in a pulse duplicator was applied to the leaflets. Through a parametric study, uniform TAV leaflet thickness was reduced from 0.5 to 0.18 mm. By reducing leaflet thickness, significantly higher stress values were found in the leaflet's fixed edge during systole, and in the commissures during diastole. Through dynamic FE simulations, the highest stress values were found during systole in the leaflet fixed edge. In contrast, at the peak of diastole high-stress regions were mainly observed in the commissures. The peak stress was increased by 178% and 507% within the leaflets after reducing the thickness of 0.5 mm to 0.18 mm at the peak of systole and diastole, respectively. The study results indicated that, the smaller the leaflet thickness, the higher the maximum principal stress. Increased mechanical stress on TAV leaflets may lead to accelerated tissue degeneration. By using a thinner leaflet, TAV durability may not atch with that of surgical bioprostheses.

THE PERMEABILITY OF THE SCLERAL TISSUE FOR ULTRAVIOLET A IN THE EXPERIMENT

Directory of Open Access Journals (Sweden)

M. M. Bikbov

2017-01-01

Full Text Available Purpose: to evaluate the permeability of the scleral tissue for ultraviolet A (UVA.Materials and Methods. The study was conducted on 15 cadaver porcine eyes. Rectangular scleral flap 12*15 mm was cut out from each eyeball. The thickness of the sample was measured with a digital caliper. The outer surface of the scleral flap was irradiated with ultraviolet A. A sensor of the UV-radiometer was placed under the sample. It measured the UVA irradiance passing through the sclera. The absorption coefficient of ultraviolet A by the sclera was calculated from the formula derived from the Bouguer-Lambert Beer law: , where  E0 — the absorption coefficient, mm-1;  — irradiance of the transmitted light, mW/cm2; I0 — irradiance of the received light, mW/cm2; — thickness of the sclera, mm.Results. The absorption coefficient of ultraviolet A by the sclera was 4,91±0,43 mm-1. According literature the threshold damaging radiation for retina is 7.7 J/cm2. Substituting these values in the converted formula of the Bouguer-Lambert-Beer law, we can derive an equation for calculating the threshold UVA irradiation dose of the sclera: , where 0 — the threshold UVA irradiation dose of the sclera, J/cm2;  — the base of the natural logarithm; — thickness of the sclera, mm.Conclusion. The absorption coefficient of ultraviolet A by the cadaver porcine sclera is 4,91±0,43 mm-1. The derived formula of the threshold UVA irradiation dose of the sclera calculating allows to avoid the threatening for the retina procedure parameters in the performance of the scleral crosslinking with riboflavin/UVA.

Facial soft tissue thickness database of Gujarati population for forensic craniofacial reconstruction

Directory of Open Access Journals (Sweden)

Anand Lodha

2016-06-01

Full Text Available The forensic facial reconstruction is a scientific art to construct the ante-mortem face from the human skull. The facial recognition is made by reconstructing the contours of the facial soft tissue thickness (FSTT.These FSTT data are essential for probable face reconstruction but the data of FSTT at particular anthropological landmarks differ in various ethnic groups. Until now several works have been reported on different population but no study exists in which the FSTT of a Gujarati population has been measured. The aim of this study is to compile a set of soft tissue depth data of Gujarati population of India to add to existing literature on FSTT. Computed tomography (CT-scan has been utilized to measure the 25 different FSTT landmarks of 324 male and 165 female. Present study shows significant differences in certain FSTT of Gujarati population from that of other populations. Our compiled data set of FSTT for the Gujarati population is important in understanding craniofacial characteristics of the Gujarati population and potentially be helpful in forensic identification.

Effects of low-dose irradiation of X-rays on IUdR incorporation into mouse tissues

International Nuclear Information System (INIS)

Misonoh, J.; Ishii, K.; Yoshida, M.; Okumura, Y.; Kodama, S.

1992-01-01

It is well known that biological responses get smaller when a radiation dose gets lower, and it makes it difficult to detect them with significant differences from background levels. Therefore we know little about biological effects arisen from very low-dose radiation in mammals and mammalian cells. Feinendegen et al. detected a significant reduction of 125 I-UdR uptake in bone marrow cells at doses below 0.01 Gy. Using this extremely sensitive biological response, they also indicated that cells of mice irradiated twice with an interval of 4 hours did not show any reaction after the second irradiation. This meant that cells became radio-resistant after whole-body irradiation with low-doses. This phenomenon, an acquired radio-resistance after low-dose irradiation, is explained as an adaptive response to radiation , which is recently well documented in cytogenic studies. In order to confirm that whether it is common in the cell renewal systems, IUdR incorporation into mouse spleen and the other tissues were studied after whole-body irradiation. (author). 7 refs., 1 fig., 2 tabs

Radiotherapy. Non-standard fractionated regimens improving cancer treatment. Part II. Response of normal tissues to fractionated irradiation

International Nuclear Information System (INIS)

Villar, A.; Hernandez, M.; Pera, J.; Cambray, M.; Villa, S.; Arnaiz, M.D.

1988-01-01

The phenomena participating in the response of tissues to fractionated irradiation are analyzed with special emphasis on the most relevant points influencing the design of non-standard fractionated regimens. (Author)

Study on Dental Treatment with YAG Laser (1st Report): Temperature of Dental Tissue Irradiated with Laser Beam

OpenAIRE

上田, 隆司; 山田, 啓司; 古本, 達明

2000-01-01

The flash temperature of a dental hard tissue irradiated with pulsed Nd:YAG laser is measured using a two-color pyrometer with an optical fiber. This pyrometer consists of a chalcogenide optical fiber and a laminated infrared detector. The influence of the laser power on the temperature of the dental tissue is investigated, and the relationship between the laser power and the removal volume of the dental tissue is obtained. In order to examine the thermal damage on the dental tissue, hardness...

Two-dimensional and 3-D images of thick tissue using time-constrained times-of-flight and absorbance spectrophotometry

Science.gov (United States)

Benaron, David A.; Lennox, M.; Stevenson, David K.

1992-05-01

Reconstructing deep-tissue images in real time using spectrophotometric data from optically diffusing thick tissues has been problematic. Continuous wave applications (e.g., pulse oximetry, regional cerebral saturation) ignore both the multiple paths traveled by the photons through the tissue and the effects of scattering, allowing scalar measurements but only under limited conditions; interferometry works poorly in thick, highly-scattering media; frequency- modulated approaches may not allow full deconvolution of scattering and absorbance; and pulsed-light techniques allow for preservation of information regarding the multiple paths taken by light through the tissue, but reconstruction is both computation intensive and limited by the relative surface area available for detection of photons. We have developed a picosecond times-of-flight and absorbance (TOFA) optical system, time-constrained to measure only photons with a narrow range of path lengths and arriving within a narrow angel of the emitter-detector axis. The delay until arrival of the earliest arriving photons is a function of both the scattering and absorbance of the tissues in a direct line between the emitter and detector, reducing the influence of surrounding tissues. Measurement using a variety of emitter and detector locations produces spatial information which can be analyzed in a standard 2-D grid, or subject to computer reconstruction to produce tomographic images representing 3-D structure. Using such a technique, we have been able to demonstrate the principles of tc-TOFA, detect and localize diffusive and/or absorptive objects suspended in highly scattering media (such as blood admixed with yeast), and perform simple 3-D reconstructions using phantom objects. We are now attempting to obtain images in vivo. Potential future applications include use as a research tool, and as a continuous, noninvasive, nondestructive monitor in diagnostic imaging, fetal monitoring, neurologic and cardiac

Experimental study on active specific immunotherapy utilizing the immune reaction of low-dose irradiated tumor tissue

International Nuclear Information System (INIS)

Imanaka, Kazufumi; Tanaka, Koji; Sasai, Keisuke

1984-01-01

We have already reported the effectiveness of active specific immunotherapy based on the immune reaction of low-dose irradiated tumor tissue. In the present study, three kinds of immunotherapeutic methods subdivided by used cells were performed in order to compare each effectiveness. C3H/He mice bearing MM 46 tumor transplanted in the right hind paws received local irradiation with the dose of 3,000 rad on the 6th day, and the above-mentioned three methods, using tumor cells, lymphocytes, and tumor cells combining lymphocytes which were all separated from the topical tumor tissue exposed to 2,000 rad, were applied respectively on the 14 th day. The most effective data were obtained from two groups treated by the immunotherapy with tumor cells combining lymphocytes, which virtually caused the longest survival and best tumor growth control. (author)

Subcutaneous Tissue Thickness is an Independent Predictor of Image Noise in Cardiac CT

Energy Technology Data Exchange (ETDEWEB)

Staniak, Henrique Lane; Sharovsky, Rodolfo [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil); Pereira, Alexandre Costa [Hospital das Clínicas - Universidade de São Paulo, São Paulo, SP (Brazil); Castro, Cláudio Campi de; Benseñor, Isabela M.; Lotufo, Paulo A. [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil); Faculdade de Medicina - Universidade de São Paulo, São Paulo, SP (Brazil); Bittencourt, Márcio Sommer, E-mail: msbittencourt@mail.harvard.edu [Hospital Universitário - Universidade de São Paulo, São Paulo, SP (Brazil)

2014-01-15

Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation. The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively. Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure.

Subcutaneous Tissue Thickness is an Independent Predictor of Image Noise in Cardiac CT

International Nuclear Information System (INIS)

Staniak, Henrique Lane; Sharovsky, Rodolfo; Pereira, Alexandre Costa; Castro, Cláudio Campi de; Benseñor, Isabela M.; Lotufo, Paulo A.; Bittencourt, Márcio Sommer

2014-01-01

Few data on the definition of simple robust parameters to predict image noise in cardiac computed tomography (CT) exist. To evaluate the value of a simple measure of subcutaneous tissue as a predictor of image noise in cardiac CT. 86 patients underwent prospective ECG-gated coronary computed tomographic angiography (CTA) and coronary calcium scoring (CAC) with 120 kV and 150 mA. The image quality was objectively measured by the image noise in the aorta in the cardiac CTA, and low noise was defined as noise < 30HU. The chest anteroposterior diameter and lateral width, the image noise in the aorta and the skin-sternum (SS) thickness were measured as predictors of cardiac CTA noise. The association of the predictors and image noise was performed by using Pearson correlation. The mean radiation dose was 3.5 ± 1.5 mSv. The mean image noise in CT was 36.3 ± 8.5 HU, and the mean image noise in non-contrast scan was 17.7 ± 4.4 HU. All predictors were independently associated with cardiac CTA noise. The best predictors were SS thickness, with a correlation of 0.70 (p < 0.001), and noise in the non-contrast images, with a correlation of 0.73 (p < 0.001). When evaluating the ability to predict low image noise, the areas under the ROC curve for the non-contrast noise and for the SS thickness were 0.837 and 0.864, respectively. Both SS thickness and CAC noise are simple accurate predictors of cardiac CTA image noise. Those parameters can be incorporated in standard CT protocols to adequately adjust radiation exposure

Research on the dose of the tissues located outside the treatment field when breast cancer was irradiated by linear accelerator

International Nuclear Information System (INIS)

Tu Yu; Zhou Juying; Jiang Dezhi; Qin Songbing

1999-10-01

The purpose of study was to determine the dose of the tissues which located outside the treatment field, when breast cancer was irradiated by 9 MeV electron-beam and 6 MV-X ray after operation. A search for decreasing the dose of the tissues outside the treatment field was made. Clinically relevant treatment fields were simulated on a tissue-equivalent material phantom and subsequently irradiated with 9 MeV electron-beam and 6 MV-X ray. TLD were used to measure absorbed doses. The prescribed dose of breast cancer region was 50.0 Gy, region-lymph-nodes were 60.0 Gy, each exposure dose was 2.0 Gy. In breast cancer region, if only with 9 MeV electron-beam, the dose of the tissues located outside the treatment field were from 29.0 cGy to 295.5 cGy, when shielded with Pb lump, the doses of the tissues outside the treatment field may descended 9.4%-53.6%; if only with 6 MV-X ray, the doses of aforementioned tissues were from 32.0 cGy to 206.7 cGy, when shielded with Pb lump, the doses of the tissues outside the treatment field descended 19.7%-56.6%. In region-lymph-nodes, with 6 MV-X ray, the doses of aforementioned tissues were from 22.5 cGy to 1650.9 cGy, when shielded with Pb lump, the doses of the tissues outside the treatment field descended 19.7-65.6%. If mix-irradiation (9 MeV electron-beam vs. 6 MV-X ray 2:3) was used, the doses outside field would be lower than only used 9 MeV electron-beam or 6 MV-X ray were used

Chemical and physical analysis on hard tissues after irradiation with short pulse Nd:YAG laser

International Nuclear Information System (INIS)

Pereira, Andrea Antunes

2003-01-01

This work reports on a study that was designed to investigate chemical, physical and morphological alterations in the dental enamel surface. The influence of application of laser in enamel surface by microscopic technical, X-ray fluorescence for chemical analysis, physical property as well as hardness and thermal analysis with Nd:YAG laser is also pointed out. A prototype of Nd:YAG (Q-switched) laser developed at the Center of Lasers and Applications - Institute of Energetic and Nuclear Research, aiming applications in the Medical Sciences that typical wavelength of 1.064 nm was used. The modifications in human dental enamel chemical composition for major and trace elements are here outlined. The accuracy of procedures was performed by analysis of natural hydroxyapatite as standard reference material. The identification and quantification of the chemical elements presented in the dental tissue samples were performed trough EDS, XRF and INAA. We determined the rate Calcium/Phosphorus (Ca/P) for different techniques. We performed an analysis in different regions of the surface and for different areas allowing a description of the chemical change in the total area of the specimen and the assessment of the compositional homogeneity of the each specimen. A comparison between XRF and INAA is presented. Based on morphological analysis of the irradiated surfaces with short pulse Nd:YAG laser we determined the area surrounded by the irradiation for the parameters for this thesis, and this technique allowed us to visualize the regions of fusion and re-solidification. The energy densities ranged from 10 J/cm 2 to 40 J/cm 2 , with pulse width of 6, 10 e 200 ns, and repetition rates of 5 and 7 Hz. In this thesis, FTIR-spectroscopy is used to analyze powder of mineralized tissue as well as enamel, dentine, root and cementum for human and bovine teeth after irradiation with short-pulse Nd:YAG laser. Characteristic spectra were obtained for the proteins components and mineral

Irradiation of protoporphyric mice induces down-regulation of epidermal eicosanoid metabolism

International Nuclear Information System (INIS)

He, D.; Lim, H.W.

1991-01-01

This study investigated the effect of radiation on clinical and histologic changes, and on cutaneous eicosanoid metabolism, in Skh:HR-1 hairless albino mice rendered protoporphyric by the administration of collidine. At 0.1-18 h after exposure to 12 kJ/m2 of 396-406 nm irradiation, thicknesses of back skin and ears were measured, and histologic changes were evaluated by using hematoxylin and eosin (H-E) and Giemsa's stains. Activities of eicosanoid-metabolizing enzymes in epidermal and dermal homogenates were assessed by incubating the tissue homogenates with 3H-AA, followed by quantitation of the eicosanoids generated by radio-TLC. In irradiated protoporphyric mice, an increase of back-skin thickness was noted at 0.1 h, reaching a peak at 18 h, whereas maximal increase in ear thickness was observed at 12 h. Histologic changes included dermal edema, increased mast cell degranulation, and mononuclear cells in the dermis. In these irradiated protoporphyric animals, generations of 6 keto-PGF1a, PGF2a, PGE2, PGD2, and HETE by epidermal eicosanoid-metabolizing enzymes were markedly suppressed at all the timepoints studied. Dermal eicosanoid-metabolizing enzymes of irradiated protoporphyric mice generated increased amounts of PGE2 and HETE at 18 h, probably reflecting the presence of dermal cellular infiltrates. The suppression of the activities of epidermal eicosanoid-metabolizing enzymes was prevented by intraperitoneal injection of WR-2721, a sulfhydryl group generator, prior to irradiation, suggesting that the suppression was secondary to photo-oxidative damage of the enzymes during the in vivo phototoxic response. These results suggest that the effect of protoporphyrin and radiation on cutaneous eicosanoid metabolism in this animal model in vivo is that of a down regulation of the activities of epidermal eicosanoid-metabolizing enzymes

ALK1 heterozygosity delays development of late normal tissue damage in the irradiated mouse kidney

International Nuclear Information System (INIS)

Scharpfenecker, Marion; Floot, Ben; Korlaar, Regina; Russell, Nicola S.; Stewart, Fiona A.

2011-01-01

Background and Purpose: Activin receptor-like kinase 1 (ALK1) is a transforming growth factor β (TGF-β) receptor, which is mainly expressed in endothelial cells regulating proliferation and migration in vitro and angiogenesis in vivo. Endothelial cells also express the co-receptor endoglin, which modulates ALK1 effects on endothelial cells. Our previous studies showed that mice with reduced endoglin levels develop less irradiation-induced vascular damage and fibrosis, caused by an impaired inflammatory response. This study was aimed at investigating the role of ALK1 in late radiation toxicity. Material and Methods: Kidneys of ALK +/+ and ALK1 +/- mice were irradiated with 14 Gy. Mice were sacrificed at 10, 20, and 30 weeks after irradiation and gene expression and protein levels were analyzed. Results: Compared to wild type littermates, ALK1 +/- mice developed less inflammation and fibrosis at 20 weeks after irradiation, but displayed an increase in pro-inflammatory and pro-fibrotic gene expression at 30 weeks. In addition, ALK1 +/- mice showed superior vascular integrity at 10 and 20 weeks after irradiation which deteriorated at 30 weeks coinciding with changes in the VEGF pathway. Conclusions: ALK1 +/- mice develop a delayed normal tissue response by modulating the inflammatory response and growth factor expression after irradiation.

Fluid distribution and tissue thickness changes in 29 men during 1 week at moderate altitude (2,315 m).

Science.gov (United States)

Gunga, H C; Kirsch, K; Baartz, F; Steiner, H J; Wittels, P; Röcker, L

1995-01-01

To quantify fluid distribution at a moderate altitude (2,315 m) 29 male subjects were studied with respect to tissue thickness changes [front (forehead), sternum, tibia], changes of total body water, changes of plasma volume, total protein concentrations (TPC), colloid osmotic pressure (COP), and electrolytes. Tissue thickness at the forehead showed a significant increase from 4.14 mm to 4.41 mm 48 h after ascent to the Rudolfshuette (2,315 m) (P Rudolf-shuette in Saalfelden (744 m) COP was back to the control values. The TPC also showed an initial drop from 7.75 g.dl-1 to 7.48 g.dl-1 after 48 h at altitude and remained below the control value during the whole week (P < 0.01). It seems from our study that even with exposure to moderate altitude measurable fluid shifts to the upper part of the body occurred which were detected by our ultrasound method.

Production of mutants by irradiation of in vitro-cultured tissues of coconut and banana and their mass propagation by the tissue culture technique

International Nuclear Information System (INIS)

Guzman, E.V. de; Rosario, A.G. del; Pagcaliwagan, P.C.

1982-01-01

Regeneration of buds/shoots as well as plantlets was induced from banana shoot tip explants cultured in highly modified Murashige and Skoog's medium supplemented with coconut water and benzyladenine. Initially shoot regeneration was sparse, but on further subculture became profuse. Gamma irradiation at low dosage (1.0 kR) was stimulating to explant growth and bud formation with the two types of explants used. With Bungulan stimulation was observed even at 2.5 kR. Several morphological aberrations were exhibited by shoots of 'irradiated' in vitro plants growing in potted soil. A highly and continuously proliferating tissue strain has been isolated from a subculture which was ultimately derived from an irradiated explant. Its continued proliferation is dependent on an external supply of coconut water and benzyladenine. In vitro-produced plants have been established under field conditions. The 'irradiated' plants are comparable with, and some seem to be better than, the unirradiated controls with respect to height, girth, sucker production and number of hands and fingers per bunch. Higher doses of irradiation are required to produce an adverse effect on growth of coconut embryos during the liquid culture than when growing in solid medium. (author)

Use of high-resolution ultrasound to measure changes in plantar fascia thickness resulting from tissue creep in runners and walkers.

Science.gov (United States)

Welk, Aaron B; Haun, Daniel W; Clark, Thomas B; Kettner, Norman W

2015-01-01

This study sought to use high-resolution ultrasound to measure changes in plantar fascia thickness as a result of tissue creep generated by walking and running. Independent samples of participants were obtained. Thirty-six walkers and 25 runners walked on a treadmill for 10 minutes or ran for 30 minutes, respectively. Standardized measures of the thickness of the plantar fascia were obtained in both groups using high-resolution ultrasound. The mean thickness of the plantar fascia was measured immediately before and after participation. The mean plantar fascia thickness was decreased by 0.06 ± 0.33 mm SD after running and 0.03 ± 0.22 mm SD after walking. The difference between groups was not significant. Although the parameters of this study did not produce significant changes in the plantar fascia thickness, a slightly higher change in the mean thickness of the plantar fascia in the running group deserves further investigation. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

Effect of gamma irradiation at various temperatures and packaging conditions on chicken tissues

International Nuclear Information System (INIS)

Rady, A.H.; Maxwell, R.J.; Wierbicki, E.; Phillips, J.G.

1988-01-01

A lipid composition study on irradiated chicken muscle is reported. All muscle samples, packed either under air or vacuum, were gamma irradiated (-20 0 C) at 0, 1, 3, 6 and 10 kGy using 137 Cs (dose rate 0.1 kGy/min). Lipids were isolated from the muscle using a dry column extraction method with concomitant isolation of separated neutral and polar fractions. Lipid isolates were converted to their methyl esters and analyzed by capillary column gas chromatography with computer assisted data storage, followed by data consolidation and statistical computer analysis. Separated fatty acid profiles for neutral and polar lipids were obtained as normalized reports (each fatty acid as percentage of total fatty acids) and as gravimetric reports (mg of each fatty acid/100 g tissue). Normalized reports showed only negligible occurrence of significant changes in fatty acid profiles of neutral muscle lipid fractions regardless of irradiation doses (0 to 10 kGy) in either air and vacuum packaging. These differences were not apparent when the data were compiled as gravimetric reports. The polar lipid fractions containing the nutritionally significant ω3 and ω6 fatty acids showed only slight changes in normalized and gravimetric reports and were similarly unaffected with increasing levels of irradiation. Additionally, no new fatty acids or other artifacts due to gamma-irradiation were observed in detectable amounts by gas chromatography in any lipid fractions. (author)

Vertical leaf mass per area gradient of mature sugar maple reflects both height-driven increases in vascular tissue and light-driven increases in palisade layer thickness.

Science.gov (United States)

Coble, Adam P; Cavaleri, Molly A

2017-10-01

A key trait used in canopy and ecosystem function modeling, leaf mass per area (LMA), is influenced by changes in both leaf thickness and leaf density (LMA = Thickness × Density). In tall trees, LMA is understood to increase with height through two primary mechanisms: (i) increasing palisade layer thickness (and thus leaf thickness) in response to light and/or (ii) reduced cell expansion and intercellular air space in response to hydrostatic constraints, leading to increased leaf density. Our objective was to investigate within-canopy gradients in leaf anatomical traits in order to understand environmental factors that influence leaf morphology in a sugar maple (Acer saccharum Marshall) forest canopy. We teased apart the effects of light and height on anatomical traits by sampling at exposed and closed canopies that had different light conditions at similar heights. As expected, palisade layer thickness responded strongly to cumulative light exposure. Mesophyll porosity, however, was weakly and negatively correlated with light and height (i.e., hydrostatic gradients). Reduced mesophyll porosity was not likely caused by limitations on cell expansion; in fact, epidermal cell width increased with height. Palisade layer thickness was better related to LMA, leaf density and leaf thickness than was mesophyll porosity. Vein diameter and fraction of vascular tissue also increased with height and LMA, density and thickness, revealing that greater investment in vascular and support tissue may be a third mechanism for increased LMA with height. Overall, decreasing mesophyll porosity with height was likely due to palisade cells expanding into the available air space and also greater investments in vascular and support tissue, rather than a reduction of cell expansion due to hydrostatic constraints. Our results provide evidence that light influences both palisade layer thickness and mesophyll porosity and indicate that hydrostatic gradients influence leaf vascular and support

Manual for target thickness measurement by alpha particle irradiation

International Nuclear Information System (INIS)

Dias, J.F.; Martins, M.N.

1990-04-01

A system is described for thin-target thickness measurement through the alpha particle energy loss when them traverse the target. It is also described the program used in the analysis of the target thickness. (L.C.) [pt

Effects of gamma radiation on hard dental tissues of albino rats: investigation by light microscopy.

Science.gov (United States)

El-Faramawy, Nabil; Ameen, Reham; El-Haddad, Khaled; El-Zainy, Medhat

2013-08-01

The present work aims at studying the effect of gamma radiation on the hard dental tissues. Eighty adult male albino rats with weights of about 250 g were used. The rats were irradiated at 0.2, 0.5, 1.0, 2.0, 4.0 and 6.0 Gy whole-body gamma doses. The effects on hard dental tissue samples were investigated after 48 h in histological and ground sections using light microscopy. Areas of acid phosphatase activity were detected using tartrate-resistant acid phosphatase (TRAP) stains. Observation of histological sections revealed disturbance in predentin thickness and odontoblastic layer as the irradiation dose increased. In cementum, widened cementocytes lacunae were occasionally detected even with low irradiated doses. On the other hand, relatively homogenous enamel was detected with darkened areas in enamel surface at doses over than 0.5 Gy. TRAP-positive cells were detected on the surface of the dentin of irradiated groups as well as cementum surface. Minimal detectable changes were observed in ground sections.

Intraoperative extracorporeal autogenous irradiated tendon grafts for functional limb salvage surgery of soft tissue sarcomas of the wrist and hand.

Science.gov (United States)

Omori, Shinsuke; Hamada, Kenichiro; Outani, Hidetatsu; Oshima, Kazuya; Joyama, Susumu; Tomita, Yasuhiko; Naka, Norifumi; Araki, Nobuhito; Yoshikawa, Hideki

2015-05-12

In patients with soft tissue sarcoma of the wrist and hand, limb salvage operation is extremely challenging for surgeons in attempting a complete tumor resection with negative surgical margins. In this study, we report four patients with soft tissue sarcoma of the wrist and hand treated by limb salvage operation with intraoperative extracorporeal autogenous irradiated tendon grafts. The patients were all male, and the mean age at the time of surgery was 45 years. Histological diagnoses included clear cell sarcoma in two patients, synovial sarcoma in one, and angiosarcoma in one. All four patients had high grade tumors, wherein three had American Joint Committee on Cancer (AJCC) stage III disease and one with AJCC stage IV disease. The tumors were resected en bloc with involved tendons. The tendons were isolated from the resected tissues, irradiated ex vivo, and re-implanted into the host tendons. In one patient, the bone was resected additionally because of tumor invasion to the bone. Hand function was evaluated using Musculoskeletal Tumor Society (MSTS) rating system. Of the four patients, three died of distant metastatic disease. The remaining patient lives and remains disease-free. The mean follow-up period was 33 months. One patient had local recurrence outside the irradiated graft at 20 months after surgery. The functional rating was 22. Lower scores were seen in patients with reconstruction of flexor tendons than extensor tendons. Limb salvage operation with intraoperative extracorporeal autogenous irradiated tendon grafts is an acceptable method in selected patients with soft tissue sarcoma of the wrist and hand.

The Effects of Topical Agent (Kelo-Cote or Contractubex Massage on the Thickness of Post-Burn Scar Tissue Formed in Rats

Directory of Open Access Journals (Sweden)

Won Jin Ko

2013-11-01

Full Text Available BackgroundWe conducted an experimental study to compare the effect of massage using topical agents (Kelo-cote or Contractubex on scar formation by massaging the healed burn wound on the dorsal area of Sprague-Dawley (SD rats.MethodsFour areas of second degree contact burn were made on the dorsal area of each of 15 SD rats, using a soldering iron 15 mm in diameter. After gross epithelialization in the defect, 15 SD rats were randomly divided into four groups: the Kelo-cote group, Contractubex group, Vaseline group, and control group. Rats in three of the groups (all but the Control group were massaged twice per day for 5 minutes each day, while those in the Control group were left unattended. For histologic analysis, we performed a biopsy and evaluated the thickness of scar tissue.ResultsIn the Kelo-cote and Contractubex groups, scar tissue thicknesses showed a significant decrease, compared with the Vaseline and control groups. However, no significant differences were observed between the Kelo-cote and Contractubex groups. In the Vaseline group, scar tissue thicknesses showed a significant decrease, compared with the control groups.ConclusionsThe findings of this study suggest that massage using a topical agent is helpful in the prevention of scar formation and that massage only with lubricant (no use of a topical agent also has a considerable effect, although not as much as the use of a topical agent. Thus, we recommend massage with a topical agent on the post-burn scar as an effective method for decreasing the scar thickness.

The influence of parenteral nitrogen feeding on free amino acid composition of blood serum and hepatic tissue of irradiated rats

International Nuclear Information System (INIS)

Mil'ko, V.I.; Kirichenko, A.V.; Chalaya, L.A.

1985-01-01

A considerable change in the free am ino acid composition of blood serum and hepatic tissued was noted on the 7th and 14th days following total-body X-irradiation of rats with a dose of 2.9 Gy. The total free amino acid content of blood serum increased and that of hepatic tissue decreased by 85% (on an average) as compared to the intact controls. Quantitative changes in the content of individual amino acids were analysed. Polyamine injected enterally for 7 days and parenterally for 3 days after irradiation a the elimination of the postirradiation changes in the amino acid balance

Effects of bleomycin and x irradiation on the frequency of chromosomal aberrations in selected connective tissue diseases

International Nuclear Information System (INIS)

Burkhardt, W.C. Jr.

1978-01-01

Whole blood lymphocytes from 28 patients with selected connective tissue disorders (6 progressive systemic sclerosis (PSS), 6 anti-nuclear antibody positive rheumatoid arthritis, 6 anti-nuclear antibody negative rheumatoid arthritis, 6 systemic lupus erythematosus, and 4 mixed connective tissue disease) and 17 controls matched for sex, age, and race were studied to determine the frequency of spontaneous as well as bleomycin and/or x-irradiation induced chromosomal aberrations. The effects of bleomycin on cultured lymphocytes were tested, but differential susceptibilities to this clastogen were not demonstrated among the disease groups and controls investigated. However, the combined effect of bleomycin and x irradiation were found to be additive in control lymphocytes, nearly additive in PSS, RA+, and SLE cultures, but reduced considerably from the expected additive value in Ra- cultures. This study indicated that peripheral blood lymphocytes from patients with connective tissue disease, as a whole, possess greater frequencies of spontaneous chromosomal aberrations than matched controls and that x rays can produce greater frequencies of chromosomal aberrations in whole blood lymphocytes of PSS patients than in suitably matched control individuals

An ultrasonographic evaluation of skin thickness in breast cancer patients after postmastectomy radiation therapy

Directory of Open Access Journals (Sweden)

Baggarley Shaun

2011-01-01

Full Text Available Abstract Background To determine the usefulness of ultrasonography in the assessment of post radiotherapy skin changes in postmastectomy breast cancer patients. Methods Patients treated for postmastectomy radiotherapy in National University Hospital (NUH and Tan Tock Seng Hospital (TTSH, Singapore between January 2004- December 2005 was recruited retrospectively. Ultrasound scan was performed on these Asian patients who had been treated to a total dose of 46-50 Gy with 1 cm bolus placed on the skin. The ultrasound scans were performed blinded to the RTOG scores, and the skin thickness of the individually marked points on the irradiated chest wall was compared to the corresponding points on the non-irradiated breast. Results The mean total skin thickness inclusive of the epidermis and the dermis of the right irradiated chest wall was 0.1712 mm (± 0.03392 mm compared with the contra-lateral non-irradiated breast which was 0.1845 mm (± 0.04089 mm; p = 0.007. The left irradiated chest wall had a mean skin thickness of 0.1764 mm (± 0.03184 mm compared with the right non-irradiated breast which was 0.1835 mm (± 0.02584 mm; p = 0.025. These independent t-tests produced a significant difference of reduced skin thickness on the right irradiated chest wall, p = 0.007 (p Conclusions This study has shown that there is a statistically significant difference between the skin thicknesses of the irradiated chest wall and the contra-lateral non-irradiated breast and a predisposition to chronic reactions was found in patients with acute RTOG scoring of grade1 and grade 2.

Heat generation caused by ablation of dental hard tissues with an ultrashort pulse laser (USPL) system.

Science.gov (United States)

Braun, Andreas; Krillke, Raphael Franz; Frentzen, Matthias; Bourauel, Christoph; Stark, Helmut; Schelle, Florian

2015-02-01

Heat generation during the removal of dental hard tissues may lead to a temperature increase and cause painful sensations or damage dental tissues. The aim of this study was to assess heat generation in dental hard tissues following laser ablation using an ultrashort pulse laser (USPL) system. A total of 85 specimens of dental hard tissues were used, comprising 45 specimens of human dentine evaluating a thickness of 1, 2, and 3 mm (15 samples each) and 40 specimens of human enamel with a thickness of 1 and 2 mm (20 samples each). Ablation was performed with an Nd:YVO4 laser at 1,064 nm, a pulse duration of 9 ps, and a repetition rate of 500 kHz with an average output power of 6 W. Specimens were irradiated for 0.8 s. Employing a scanner system, rectangular cavities of 1-mm edge length were generated. A temperature sensor was placed at the back of the specimens, recording the temperature during the ablation process. All measurements were made employing a heat-conductive paste without any additional cooling or spray. Heat generation during laser ablation depended on the dental hard tissue (enamel or dentine) and the thickness of the respective tissue (p dental hard tissues, heat generation has to be considered. Especially during laser ablation next to pulpal tissues, painful sensations and potential thermal injury of pulp tissue might occur.

Early ultrastructural changes in the dorsal mucosa of rat tongue after irradiation, with special reference to the microvasculature

International Nuclear Information System (INIS)

Obinata, Ken-ichi; Ohshima, Hayato; Ito, Jusuke; Takano, Yoshiro.

1997-01-01

To clarify the acute effects of irradiation on the ultrastructural conformation of the dorsal mucosa of the rat tongue, with special reference to the changes in microvasculature. The proboscis of seventy rats were irradiated. The animals were then perfusion-fixed, followed by India ink-injection or resin casting at 3 to 7 days after irradiation. The bulk, frozen sections, or plastic embedded sections of the treated rat tongues were examined by light and electron microscopy. In the dorsal epithelium of the rat tongue, multi-nucleated cells appeared in the basal layer at 3 days after irradiation. At day 5, the thickness of the epithelial layer and connective tissue papillae decreased dramatically, concomitant with the shortening of the capillary loops. At day 7, lingual papillae and connective tissue papillae disappeared, leaving dissociated epithelial cells and numerous neutrophils migrating throughout the tissue. Subepithelial blood vessels displayed drastic dilation with a number of neutrophils adhering to the endothelial surface, but without ultrastructural abnormalities in its cellular components. Early changes in the dorsal mucosa of the irradiated rat tongue were limited to the basal epithelial cells, leading to a total disruption of the epithelial layer. Atrophic changes of the capillary loops is due to the loss of the connective tissue papillae. Dilation and conformational changes of the subepithelial capillaries appear to result from the inflammatory reaction, taking place secondarily to the loss of the epithelial barrier of the irradiated tongue. A difference in radiosensitivity among the epithelial, endothelial, and mesenchymal cell components of the rat tongue in vivo is suggested. (author)

Radiorestoring activity of few nucleotides on normal tissues of Jerusalem Artichoke after an irradiation with γ rays of 60Co

International Nuclear Information System (INIS)

Jonard, Robert; Bayonove, Jacqueline; Riedel, Michel.

1978-01-01

The nucleotides tested: adenosine triphosphate (ATP) and cyclic adenosine 3',5'-monophosphate (3',5'-cAMP), guanosine triphosphate (GTP) and cyclic guanosine 3',5'-monophosphate (3',5'-cGMP), are able to restore proliferation to irradiated (γ irradiation, 3,000 rad) Jesusalem Artichoke tissue. The 3',5'-cGMP shows the greater radiorestoring activity [fr

Dose effect comparisons between HFR and BMRR irradiated dogs with respect to healthy tissue tolerance

International Nuclear Information System (INIS)

Huiskamp, R.; Philipp, K.H.I.; Gavin, P.R.; Wheeler, F.J.; Siefert, A.

1993-01-01

Epithermal neutron beams are being developed for the application of boron neutron capture therapy (BNCT) of deep seated tumors, like glioblastoma and astrocytomas, through the intact skin. Epithermal neutrons will be moderated by the tissue mass between skin and tumour to produce the thermal neutrons necessary for the 10 B(n,α) 7 Li reaction in the target tissue. Although the neutron capture cross-sections of elements in normal tissue are several orders of magnitude lower that for boron, the high abundance of hydrogen and nitrogen will cause a significant contribution to the total absorbed radiation dose through the 1 H(n,γ) 2 H and the 14 N(n,p) 14 C reaction, respectively. Due to inevitable incomplete filtration, an epithermal beam will also contain a fast neutron component, i.e. neutrons with energies ≥ 10 keV, and a γ-photon component originating from the reactor and produced in structural and filter materials. Therefore, the resultant radiation consists of a complex of low and high LET radiation of which the constitutents vary rapidly with depth in tissue. Based on the ongoing canine healthy tissue tolerance study at the Brookhaven Medical Research Reactor (BMRR) using the epithermal beam without BSH, the relative biological effectiveness (RBE) of the fast neutron beam component has been determined for skin reactions. In addition, a open-quotes compound factorclose quotes, i.e geometry x RBE, for the 10 B(n,α) 7 Li reaction was derived for dogs irradiated at the BMRR with the epithermal beam and BSH (Gavin et al.). Currently, a healthy tissue tolerance study with BSH is being carried out at the HB11 epithermal beam of the High Flux Reactor at Petten. The present paper describes preliminary dose effect comparisons between High Flux Reactor (HFR) and BMRR irradiated dogs with respect to healthy tissue tolerance in order to refine the BSH compound factors and the fast neutron RBE for skin and brain

Changes in regional blood flow of normal and tumor tissues following hyperthermia and combined X-ray irradiation

International Nuclear Information System (INIS)

Suga, Kazuyoshi

1986-01-01

Hyperthermia and X-ray irradiation were given to Ehrlich tumors, which were induced in the ventrum of the right hind foot of ICR mice, and to the normal tissues. Their effects on regional blood flow were examined using Xe-133 local clearance method. Blood flow of the normal tissues remained unchanged by heating at 41 deg C for 30 minutes, and increased by heating at 43 deg C and 45 deg C for 30 minutes. On the contrary, blood flow of the tumors decreased with an increase in temperature. When hypertermia (43 deg C for 30 minutes) was combined with irradiation of 30 Gy, decrease in blood flow of the tumors was greater than the normal tissues at 24 hours. Blood flow of the tumors depended on tumor size. The decreased amount of blood flow by hyperthermia was more for tumors > 250 mm 3 than tumors 3 . Blood flow ratios of tumor to normal tissues were also smaller in tumors > 250 mm 3 than tumors 3 . In the case of tumors 3 , blood flow tended to return to normal at 3 hr after heating at 43 deg C for 30 min. However, this was not seen in tumors > 250 mm 3 . (Namekawa, K.)

Effects of tissue inhomogeneities on dose patterns in cylinders irradiated by negative pion beams

International Nuclear Information System (INIS)

Hamm, R.N.; Wright, H.A.; Turner, J.E.

1975-10-01

Effects of the presence of inhomogeneities in tissue irradiated by negative pion beams are investigated. Soft-tissue targets are considered with embedded regions of bone and cavities of air. The absorbed dose is calculated as a function of position in the targets for parallel and converging beams and for two parallel beams that enter the target from opposite sides. Isodose contours are calculated and displayed in each case. While these studies show expected trends, they indicate that specific calculations are needed for other beam parameters and target geometries. The contributions of neutrons to the dose contours can be seen from several calculations made both with and without neutrons

Apple's dehydration by the irradiation pretreatment

International Nuclear Information System (INIS)

Fu Junjie; Chao Yan; Shen Weiqiao; Wang Jun

2001-01-01

"6"0 Co γ-ray irradiation was used as a pre-treatment method to dry the apple. The aim of this study was to discover the effect factor concerning the change of the apple cell structure which would affect the speed of drhydration and the relation between the speed of hot air dehydration and the irradiation dose. The results demonstrated that with the increasing of irradiation dose. The damage of apple's vacuole membrane increased. The positive correlation was shown in slice thickness and dehydration rate, the relation of the irradiation dose and the temperature of hot air was negatively correlated. The optimum of pre-treatment was gained for slice thickness, the irradiation dose and dry temperature of hot air. (authors)

Monte Carlo simulation studies for the determination of microcalcification thickness and glandular ratio through dual-energy mammography

Science.gov (United States)

Del Lama, L. S.; Godeli, J.; Poletti, M. E.

2017-08-01

The majority of breast carcinomas can be associated to the presence of calcifications before the development of a mass. However, the overlapping tissues can obscure the visualization of microcalcification clusters due to the reduced contrast-noise ratio (CNR). In order to overcome this complication, one potential solution is the use of the dual-energy (DE) technique, in which two different images are acquired at low (LE) and high (HE) energies or kVp to highlight specific lesions or cancel out tissue background. In this work, the DE features were computationally studied considering simulated acquisitions from a modified PENELOPE Monte Carlo code. The employed irradiation geometry considered typical distances used in digital mammography, a CsI detection system and an updated breast model composed of skin, microcalcifications and glandular and adipose tissues. The breast thickness ranged from 2 to 6 cm with glandularities of 25%, 50% and 75%, where microcalcifications with dimensions from 100 up to 600 μm were positioned. In general, results pointed an efficiency index better than 87% for the microcalcification thicknesses and better than 95% for the glandular ratio. The simulations evaluated in this work can be used to optimize the elements from the DE imaging chain, in order to become a complementary tool for the conventional single-exposure images, especially for the visualization and estimation of calcification thicknesses and glandular ratios.

Thickness Dependent on Photocatalytic Activity of Hematite Thin Films

Directory of Open Access Journals (Sweden)

Yen-Hua Chen

2012-01-01

Full Text Available Hematite (Fe2O3 thin films with different thicknesses are fabricated by the rf magnetron sputtering deposition. The effects of film thicknesses on the photocatalytic activity of hematite films have been investigated. Hematite films possess a polycrystalline hexagonal structure, and the band gap decreases with an increase of film thickness. Moreover, all hematite films exhibit good photocatalytic ability under visible-light irradiation; the photocatalytic activity of hematite films increases with the increasing film thickness. This is because the hematite film with a thicker thickness has a rougher surface, providing more reaction sites for photocatalysis. Another reason is a lower band gap of a hematite film would generate more electron-hole pairs under visible-light illumination to enhance photocatalytic efficiency. Experimental data are well fitted with Langmuir-Hinshelwood kinetic model. The photocatalytic rate constant of hematite films ranges from 0.052 to 0.068 min-1. This suggests that the hematite film is a superior photocatalyst under visible-light irradiation.

Acute and chronic response of articular cartilage to Ho:YAG laser irradiation

Science.gov (United States)

Trauner, Kenneth B.; Nishioka, Norman S.; Flotte, Thomas J.; Patel, Dinesh K.

1992-06-01

A Ho:YAG laser system operating at a wavelength of 2.1 microns has recently been introduced for use in arthroscopic surgery. The acceptability of this new tool will be determined not only by its ability to resect tissue, but also by its long term effects on articular surfaces. In order to investigate these issues further, we performed two studies to evaluate the acute and chronic effects of the laser on cartilaginous tissue. We evaluated the acute, in vitro effects of 2.1 micron laser irradiation on articular and fibrocartilage. This included the measurement of ablation efficiency, ablation threshold and thermal damage in both meniscus and articular cartilage. To document the chronic effects on articular cartilage in vivo, we next performed a ten week healing study. Eight sheep weighing 30 - 40 kg underwent bilateral arthrotomy procedures. Multiple full thickness and partial thickness defects were created. Animals were sacrificed at 0, 2, 4, and 10 weeks. The healing study demonstrated: (1) no healing of full or partial thickness defects at 10 weeks with hyaline cartilage; (2) fibrocartilaginous granulation tissue filling full thickness defects at two and four weeks, but no longer evident at ten weeks; (3) chondrocyte necrosis extending to greater than 900 microns distal to ablation craters at four weeks with no evidence of repair at later dates; and (4) chondrocyte hyperplasia at the borders of the damage zone at two weeks but no longer evident at later sacrifice dates.

Changes of the lactate dehydrogenase in the tissue fraction with Walker carcinoma under irradiation

International Nuclear Information System (INIS)

Schultheis, W.

1972-01-01

The behaviour of LDH, GOT and GPT of one and the same tissue with and without irradiation treatment as a means of cancer diagnosis is presented. Parallel to this, the corresponding blood values are determined, and an agar-gel isoenzyme separation of the LDH is carried out. In the 11 day-old Walker carcinoma of the rat, total tumour LDH as well as total serum LDH are increased. The X-radiation does not affect the result. The M 4 isoenzyme is mainly found in the tumour tissue, to whose benefit the tumour sera also change. In tissue processing, LDH, GOT and GPT behave corresponding to their occurence in the cell compartments. The enzymes, however, appear to differ in their solution behaviour. X-radiation leeds to an early removal of these enzymes in the sense of an 'enzyme release'. (BSC/LH) [de

Cell and tissue kinetics of the subependymal layer in mouse brain following heavy charged particle irradiation

International Nuclear Information System (INIS)

Manley, N.B.

1988-01-01

The following studies investigate the cellular response and cell population kinetics of the subependymal layer in the mouse brain exposed to heavy charged particle irradiation. Partial brain irradiation with helium and neon ions was confined to one cortex of the brain. Both the irradiated and the unirradiated contralateral cortex showed similar disturbances of the cell and tissue kinetics in the subependymal layers. The irradiated hemisphere exhibited histological damage, whereas the unirradiated side appeared normal histologically. The decrease in the values of the labeling indices 1 week after charged particle irradiation was dose- and ion-dependent. Mitotic indices 1 week after 10 and 25 Gy helium and after 10 Gy neon were the same as those seen in the control mice. Analysis of cell kinetics 1 week after 10 Gy helium and 10 Gy neon irradiation suggests the presence of a progenitor subpopulation that is proliferating with a shorter cell cycle. Comparison of the responses to the different charged particle beams indicates that neon ions are more effective in producing direct cellular damage than the helium ions, but the surviving proliferating cells several divisions later continue to maintain active cell renewal. Based on the 1 week post-irradiation H 3 -TdR labeling indices, a rough estimate of the RBE for neon ions is at least 2.5 when compared to helium ions

Suberoylanilide hydroxamic acid affects γH2AX expression in osteosarcoma, atypical teratoid rhabdoid tumor and normal tissue cell lines after irradiation

International Nuclear Information System (INIS)

Blattmann, C.; Oertel, S.; Thiemann, M.; Weber, K.J.; Schmezer, P.; Zelezny, O.; Lopez Perez, R.; Kulozik, A.E.; Debus, J.; Ehemann, V.

2012-01-01

Osteosarcoma and atypical teratoid rhabdoid tumors are tumor entities with varying response to common standard therapy protocols. Histone acetylation affects chromatin structure and gene expression which are considered to influence radiation sensitivity. The aim of this study was to investigate the effect of the combination therapy with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) and irradiation on atypical teratoid rhabdoid tumors and osteosarcoma compared to normal tissue cell lines. Clonogenic assay was used to determine cell survival. DNA double-strand breaks (DSB) were examined by pulsed-field electrophoresis (PFGE) as well as by γH2AX immunostaining involving flow cytometry, fluorescence microscopy, and immunoblot analysis. SAHA lead to an increased radiosensitivity in tumor but not in normal tissue cell lines. γH2AX expression as an indicator for DSB was significantly increased when SAHA was applied 24 h before irradiation to the sarcoma cell cultures. In contrast, γH2AX expression in the normal tissue cell lines was significantly reduced when irradiation was combined with SAHA. Analysis of initial DNA fragmentation and fragment rejoining by PFGE, however, did not reveal differences in response to the SAHA pretreatment for either cell type. SAHA increases radiosensitivity in tumor but not normal tissue cell lines. The increased H2AX phosphorylation status of the SAHA-treated tumor cells post irradiation likely reflects its delayed dephosphorylation within the DNA damage signal decay rather than chromatin acetylation-dependent differences in the overall efficacy of DSB induction and rejoining. The results support the hypothesis that combining SAHA with irradiation may provide a promising strategy in the treatment of solid tumors. (orig.)

Evaluation of radio-protective effect of melatonin on whole body irradiation induced liver tissue damage.

Science.gov (United States)

Shirazi, Alireza; Mihandoost, Ehsan; Ghobadi, Ghazale; Mohseni, Mehran; Ghazi-Khansari, Mahmoud

2013-01-01

Ionizing radiation interacts with biological systems to induce excessive fluxes of free radicals that attack various cellular components. Melatonin has been shown to be a direct free radical scavenger and indirect antioxidant via its stimulatory actions on the antioxidant system.The aim of this study was to evaluate the antioxidant role of melatonin against radiation-induced oxidative injury to the rat liver after whole body irradiation. In this experimental study,thirty-two rats were divided into four groups. Group 1 was the control group, group 2 only received melatonin (30 mg/kg on the first day and 30 mg/kg on the following days), group 3 only received whole body gamma irradiation of 10 Gy, and group 4 received 30 mg/kg melatonin 30 minutes prior to radiation plus whole body irradiation of 10 Gy plus 30 mg/kg melatonin daily through intraperitoneal (IP) injection for three days after irradiation. Three days after irradiation, all rats were sacrificed and their livers were excised to measure the biochemical parameters malondialdehyde (MDA) and glutathione (GSH). Each data point represents mean ± standard error on the mean (SEM) of at least eight animals per group. A one-way analysis of variance (ANOVA) was performed to compare different groups, followed by Tukey's multiple comparison tests (p<0.05). The results demonstrated that whole body irradiation induced liver tissue damage by increasing MDA levels and decreasing GSH levels. Hepatic MDA levels in irradiated rats that were treated with melatonin (30 mg/kg) were significantly decreased, while GSH levels were significantly increased, when compared to either of the control groups or the melatonin only group. The data suggest that administration of melatonin before and after irradiation may reduce liver damage caused by gamma irradiation.

Effect of low dose x irradiation on the succinate dehydrogenase activity of guinea pig, rat and mouse tissues

Energy Technology Data Exchange (ETDEWEB)

Shah, V C; Bhatavdekar, J M; Aravinda Babu, K [Gujarat Univ., Ahmedabad (India). Dept. of Zoology

1976-07-01

The histochemical changes in succinate dehydrogenase (SDH) were investigated in pectoralis major muscle of guinea pig, rat and mouse after level X-irradiation (72 R and 240 R) and compared with control animals. Biochemical studies were carried out on liver, kidney, muscle (pectoralis major), adrenal and spleen of these animals after low dose local X-irradiation and compared with control animals. Changes in SDH activity were studied up to 72-h post-irradiation, which shows that low dose local X-irradiation leads to increased enzymic activity. The increase in enzymic activity was remarkable in mouse tissues as compared with guinea pig and rat. Adrenals of all the three animals showed significant activation after all the doses of radiation studied. The significance of these results, with special reference to oxidative metabolism, has been discussed.

Heritable Genetic Changes in Cells Recovered From Irradiated 3D Tissue Contracts. Final report

Energy Technology Data Exchange (ETDEWEB)

Cornforth, Michael N. [The University of Texas Medical Branch at Galveston, TX (United States)

2013-05-03

Combining contemporary cytogenetic methods with DNA CGH microarray technology and chromosome flow-sorting increases substantially the ability to resolve exchange breakpoints associated with interstitial deletions and translocations, allowing the consequences of radiation damage to be directly measured at low doses, while also providing valuable insights into molecular mechanisms of misrepair processes that, in turn, identify appropriate biophysical models of risk at low doses. The aims of this work apply to cells recovered from 3D tissue constructs of human skin and, for the purpose of comparison, the same cells irradiated in traditional 2D cultures. These aims are: to analyze by multi-flour fluorescence in situ hybridization (mFISH) the chromosomes in clonal descendents of individual human fibroblasts that were previously irradiated; to examine irradiated clones from Aim 1 for submicroscopic deletions by subjecting their DNA to comparative genomic hybridization (CGH) microarray analysis; and to flow-sort aberrant chromosomes from clones containing stable radiation-induced translocations and map the breakpoints to within an average resolution of 100 kb using the technique of 'array painting'.

Heritable Genetic Changes in Cells Recovered From Irradiated 3D Tissue Contracts. Final report

International Nuclear Information System (INIS)

Cornforth, Michael N.

2013-01-01

Combining contemporary cytogenetic methods with DNA CGH microarray technology and chromosome flow-sorting increases substantially the ability to resolve exchange breakpoints associated with interstitial deletions and translocations, allowing the consequences of radiation damage to be directly measured at low doses, while also providing valuable insights into molecular mechanisms of misrepair processes that, in turn, identify appropriate biophysical models of risk at low doses. The aims of this work apply to cells recovered from 3D tissue constructs of human skin and, for the purpose of comparison, the same cells irradiated in traditional 2D cultures. These aims are: to analyze by multi-flour fluorescence in situ hybridization (mFISH) the chromosomes in clonal descendents of individual human fibroblasts that were previously irradiated; to examine irradiated clones from Aim 1 for submicroscopic deletions by subjecting their DNA to comparative genomic hybridization (CGH) microarray analysis; and to flow-sort aberrant chromosomes from clones containing stable radiation-induced translocations and map the breakpoints to within an average resolution of 100 kb using the technique of 'array painting'

Localized irradiations, Evaluation through ''comet assay''

International Nuclear Information System (INIS)

Giorgio, M.D.; Taja, M.R.; Nasazzi, N.B.; Bustos, N.; Cavalieri, H.; Bolgiani, A.

2000-01-01

During the last 50 years various radiation accidents involving localized irradiations occurred, resulting mainly from improper handling of sealed sources Co 60 , Cs 137 or Ir 192 at workplaces for industrial gammagraphy. Severe skin reaction may develop at the contact sites. Such inhomogeneous irradiations lead to a differential exposure of lymphocytes in lymphatic tissues or other organs that may recirculate into the peripheral blood producing a mixed irradiated and unirradiated population of lymphocytes. Applying the mathematical models ''Contaminated Poisson'' of Dolphin and Qdr method of Sasaki, a mean dose in the irradiated body area and its size can be estimated from unstable chromosome aberration scoring. This give an indication of the proportion of haemopoietic stem cell compartment involved in the overexposure. There are also different biophysical techniques that can give responses in biological dosimetry. The ''Comet Assay'' (single cell gel electrophoresis) is a sensitive and rapid method for DNA strand break detection in individual cells. The advantages of the technique include: collection of data at the level of individual cell; the need for small numbers of cells per sample; its sensitivity for detecting DNA damage and that virtually any eukaryote cell population is amenable to analysis. The objective of this work is to apply ''Comet Assay'' method to evaluate the effect of radiation on skin and subcutaneous tissues, differentiating irradiated from unirradiated body areas. It could provide a useful tool to estimate the extension and the dose in the irradiated region, contributing with the current techniques. In this first study, we evaluate the alkaline comet assay as a method for detection of DNA radiation induced damage in keratinocytes from primary culture obtained from full thickness skin biopsies of patients requiring grafts. Skin and, particularly, keratinocytes were selected as an appropriate cellular system due to: Skin, the first barrier

Electron arc therapy: chest wall irradiation of breast cancer patients

International Nuclear Information System (INIS)

McNeely, L.K.; Jacobson, G.M.; Leavitt, D.D.; Stewart, J.R.

1988-01-01

From 1980 to October 1985 we treated 45 breast cancer patients with electron arc therapy. This technique was used in situations where optimal treatment with fixed photon or electron beams was technically difficult: long scars, recurrent tumor extending across midline or to the posterior thorax, or marked variation in depth of target tissue. Forty-four patients were treated following mastectomy: 35 electively because of high risk of local failure, and 9 following local recurrence. One patient with advanced local regional disease was treated primarily. The target volume boundaries on the chest wall were defined by a foam lined cerrobend cast which rested on the patient during treatment, functioning as a tertiary collimator. A variable width secondary collimator was used to account for changes in the radius of the thorax from superior to inferior border. All patients had computerized tomography performed to determine Internal Mammary Chain depth and chest wall thickness. Electron energies were selected based on these thicknesses and often variable energies over different segments of the arc were used. The chest wall and regional node areas were irradiated to 45 Gy-50 Gy in 5-6 weeks by this technique. The supraclavicular and upper axillary nodes were treated by a direct anterior photon field abutted to the superior edge of the electron arc field. Follow-up is from 10-73 months with a median of 50 months. No major complications were observed. Acute and late effects and local control are comparable to standard chest wall irradiation. The disadvantages of this technique are that the preparation of the tertiary field defining cast and CT treatment planning are labor intensive and expensive. The advantage is that for specific clinical situations large areas of chest wall with marked topographical variation can be optimally, homogeneously irradiated while sparing normal uninvolved tissues

SU-F-T-150: Comparing Normal Tissue Irradiated Volumes for Proton Vs. Photon Treatment Plans On Lung Patients

Energy Technology Data Exchange (ETDEWEB)

Liu, A; Mohan, R; Liao, Z [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: The aim of this work is to compare the “irradiated volume” (IRV) of normal tissues receiving 5, 20, 50, 80 and 90% or higher of the prescription dose with passively scattered proton therapy (PSPT) vs. IMRT of lung cancer patients. The overall goal of this research is to understand the factors affecting outcomes of a randomized PSPT vs. IMRT lung trial. Methods: Thirteen lung cancer patients, selected randomly, were analyzed. Each patient had PSPT and IMRT 74 Gy (RBE) plans meeting the same normal tissue constraints generated. IRVs were created for pairs of IMRT and PSPT plans on each patient. The volume of iGTV, (respiratory motion-incorporated GTV) was subtracted from each IRV to create normal tissue irradiated volume IRVNT. The average of IRVNT DVHs over all patients was also calculated for both modalities and inter-compared as were the selected dose-volume indices. Probability (p value) curves were calculated based on the Wilcoxon matched-paired signed-rank test to determine the dose regions where the statistically significant differences existed. Results: As expected, the average 5, 20 and 50% IRVNT’s for PSPT was found to be significantly smaller than for IMRT (p < 0.001, 0.01, and 0.001 respectively). However, the average 90% IRVNT for PSPT was greater than for IMRT (p = 0.003) presumably due to larger penumbra of protons and the long range of protons in lower density media. The 80% IRVNT for PSPT was also larger but not statistically distinguishable (p = .224). Conclusion: PSPT modality has smaller irradiated volume at lower doses, but larger volume at high doses. A larger cohort of lung patients will be analyzed in the future and IRVNT of patients treated with PSPT and IMRT will be compared to determine if the irradiated volumes (the magnitude of “dose bath”) correlate with outcomes.

The effect of the shape and size of gold seeds irradiated with ultrasound on the bio-heat transfer in tissue.

Science.gov (United States)

Gkigkitzis, Ioannis; Austerlitz, Carlos; Haranas, Ioannis; Campos, Diana

2015-01-01

The aim of this report is to propose a new methodology to treat prostate cancer with macro-rod-shaped gold seeds irradiated with ultrasound and develop a new computational method for temperature and thermal dose control of hyperthermia therapy induced by the proposed procedure. A computer code representation, based on the bio-heat diffusion equation, was developed to calculate the heat deposition and temperature elevation patterns in a gold rod and in the tissue surrounding it as a result of different therapy durations and ultrasound power simulations. The numerical results computed provide quantitative information on the interaction between high-energy ultrasound, gold seeds and biological tissues and can replicate the pattern observed in experimental studies. The effect of differences in shapes and sizes of gold rod targets irradiated with ultrasound is calculated and the heat enhancement and the bio-heat transfer in tissue are analyzed.

Biochemical And Biological Effects Of GAMMA Irradiation On Certain Mineral Contents In The Almond Moth Tissues, EPHESTIA CAUTELLA (WALKER)

International Nuclear Information System (INIS)

MOHAMED, H.F.; GHAREIB, O.H.

2009-01-01

In the present study, the biochemical and biological effects of two sub-sterilizing doses of gamma radiation (100 and 200 Gray) were studied on F 1 adult male and female almond moths, Ephestia cautella (Walker) (Pyralidae: Lepidoptera) descendant of irradiated parental male pupae. The insects were maintained continuously on peanuts and hazelnuts diets. Oviposition, average of adult longevity per days, the emerged adult weight, the percentage loss in diet weight and the percentage free fatty acid and peroxide values of infested peanuts and hazelnuts were determined. The effect of gamma irradiation on the relative percentage of metal contents was detected in the whole body tissues of males and females descendant of irradiated parental male pupae. The obtained results indicated that the total concentrations of the light metals (Mg, Al, Si, P, S, Cl, K and Fe) of F 1 male and female tissues at 100 and 200 Gy and reared on peanuts and hazelnuts diets were very higher than those of the heavy metals (Cu and Zn) at all treatments.

Ocular brachytherapy with a holmium-166 irradiator device

International Nuclear Information System (INIS)

Mourao, Arnaldo P.; Campos, Tarcisio P.R.

2009-01-01

The ocular brachytherapy is a method that allows controlling ocular tumors. However, the irradiation of the ocular area in high doses can bring damages mainly to the surrounding healthy tissue, such as lens, retina and bone tissue of the orbital area in growth phase. Brachytherapy in comparison to teletherapy allows a large reduction of the absorbed doses in the adjacent tissues avoiding deleterious effects. Various types of radionuclides can be applied to ocular brachytherapy. Those radionuclides shall be encapsulated and placed juxtaposed to the sclera, back to the tumor. Herein, a new device was developed to encapsulate the radioactive material. It can easily place back of the eyeball. A computational model of the ocular area was developed in order to simulate the spatial dose distribution promoted by the holmium-166 nuclide distributed inside the irradiator device. The simulations addressed a device placed on the surface of the sclera, rotated 90 deg taken at the normal axis forward to the lens. The simulation was carried on the code Monte Carlo MCNP5. The computational simulation generates the spatial dose distribution in the treated volume. All continuous beta and the discrete gamma and X-ray spectra emitted by the holmium-166 were incorporated on simulations. The results allow comparing the space dose distribution to other types of sources used for the same end. The sclera absorbed dose, the maximum apical tumor dose, as well as on the tumor base were investigated. Indeed, the tumor thickness defines the conditions of irradiation. The holmium-166 dose distribution provides a tool to propose a better and optimized protocol for ocular brachytherapy. (author)

Ocular brachytherapy with a holmium-166 irradiator device

Energy Technology Data Exchange (ETDEWEB)

Mourao, Arnaldo P. [Centro Federal de Educacao Tecnoloica de Minas Gerais (CEFET-MG), Belo Horizonte, MG (Brazil). Nucleo de Engenharia Hospitalar], e-mail: aprata@des.cefetmg.br; Campos, Tarcisio P.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-graduacao em Ciencias e Tecnicas Nucleares], e-mail: campos@nuclear.ufmg.br

2009-07-01

The ocular brachytherapy is a method that allows controlling ocular tumors. However, the irradiation of the ocular area in high doses can bring damages mainly to the surrounding healthy tissue, such as lens, retina and bone tissue of the orbital area in growth phase. Brachytherapy in comparison to teletherapy allows a large reduction of the absorbed doses in the adjacent tissues avoiding deleterious effects. Various types of radionuclides can be applied to ocular brachytherapy. Those radionuclides shall be encapsulated and placed juxtaposed to the sclera, back to the tumor. Herein, a new device was developed to encapsulate the radioactive material. It can easily place back of the eyeball. A computational model of the ocular area was developed in order to simulate the spatial dose distribution promoted by the holmium-166 nuclide distributed inside the irradiator device. The simulations addressed a device placed on the surface of the sclera, rotated 90 deg taken at the normal axis forward to the lens. The simulation was carried on the code Monte Carlo MCNP5. The computational simulation generates the spatial dose distribution in the treated volume. All continuous beta and the discrete gamma and X-ray spectra emitted by the holmium-166 were incorporated on simulations. The results allow comparing the space dose distribution to other types of sources used for the same end. The sclera absorbed dose, the maximum apical tumor dose, as well as on the tumor base were investigated. Indeed, the tumor thickness defines the conditions of irradiation. The holmium-166 dose distribution provides a tool to propose a better and optimized protocol for ocular brachytherapy. (author)

Electron irradiation of dry food products

Energy Technology Data Exchange (ETDEWEB)

Gruenewald, Th [Bundesbahn-Zentralamt, Minden (Germany, F.R.)

1983-01-01

The interest of the industrial food producer is increasing in having the irradiation facility installed in the food processing chain. The throughput of the irradiator should be high and the residence time of the product in the facility should be short. These conditions can be accomplished by electron irradiators. To clarify the irradiation conditions spices taken out of the industrial process, food grade salt, sugar, and gums as models of dry food products were irradiated. With a radiation dose of 10 kGy microbial load can be reduced on 10**4 microorganisms/g. The sensory properties of the spices were not changed in an atypical way. For food grade salt and sugar changes of colour were observed which are due to lattice defects or initiated browning. The irradiation of several gums led only in some cases to an improvement of the thickness properties in the application below 50 deg C, in most cases the thickness effect was reduced. The products were packaged before irradiation. But it would be possible also to irradiate the products without packaging moving the product through the irradiation field in a closed conveyor system.

Electron irradiation of dry food products

International Nuclear Information System (INIS)

Gruenewald, Th.

1983-01-01

The interest of the industrial food producer is increasing in having the irradiation facility installed in the food processing chain. The throughput of the irradiator should be high and the residence time of the product in the facility should be short. These conditions can be accomplished by electron irradiators. To clarify the irradiation conditions spices taken out of the industrial process, food grade salt, sugar, and gums as models of dry food products were irradiated. With a radiation dose of 10 kGy microbial load can be reduced on 10**4 microorganisms/g. The sensory properties of the spices were not changed in an atypical way. For food grade salt and sugar changes of colour were observed which are due to lattice defects or initiated browning. The irradiation of several gums led only in some cases to an improvement of the thickness properties in the application below 50 deg C, in most cases the thickness effect was reduced. The products were packaged before irradiation. But it would be possible also to irradiate the products without packaging moving the product through the irradiation field in a closed conveyor system. (author)

Heritable Genetic Changes in Cells Recovered From Irradiated 3D Tissue Constructs

Energy Technology Data Exchange (ETDEWEB)

Michael Cornforth

2012-03-26

Combining contemporary cytogenetic methods with DNA CGH microarray technology and chromosome flow-sorting increases substantially the ability to resolve exchange breakpoints associated with interstitial deletions and translocations, allowing the consequences of radiation damage to be directly measured at low doses, while also providing valuable insights into molecular mechanisms of misrepair processes that, in turn, identify appropriate biophysical models of risk at low doses. Specific aims apply to cells recovered from 3D tissue constructs of human skin and, for the purpose of comparison, the same cells irradiated in traditional 2D cultures. The project includes research complementary to NASA/HRP space radiation project.

Wound Complications in Preoperatively Irradiated Soft-Tissue Sarcomas of the Extremities

Energy Technology Data Exchange (ETDEWEB)

Rosenberg, Lewis A. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Esther, Robert J. [Department of Orthopedics, University of North Carolina, Chapel Hill, North Carolina (United States); Erfanian, Kamil [Department of Surgery, University of North Carolina, Chapel Hill, North Carolina (United States); Green, Rebecca [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Kim, Hong Jin; Sweeting, Raeshell [Department of Surgery, University of North Carolina, Chapel Hill, North Carolina (United States); Tepper, Joel E., E-mail: tepper@med.unc.edu [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States)

2013-02-01

Purpose: To determine whether the involvement of plastic surgery and the use of vascularized tissue flaps reduces the frequency of major wound complications after radiation therapy for soft-tissue sarcomas (STS) of the extremities. Methods and Materials: This retrospective study evaluated patients with STS of the extremities who underwent radiation therapy before surgery. Major complications were defined as secondary operations with anesthesia, seroma/hematoma aspirations, readmission for wound complications, or persistent deep packing. Results: Between 1996 and 2010, 73 patients with extremity STS were preoperatively irradiated. Major wound complications occurred in 32% and secondary operations in 16% of patients. Plastic surgery closed 63% of the wounds, and vascularized tissue flaps were used in 22% of closures. When plastic surgery performed closure the frequency of secondary operations trended lower (11% vs 26%; P=.093), but the frequency of major wound complications was not different (28% vs 38%; P=.43). The use of a vascularized tissue flap seemed to have no effect on the frequency of complications. The occurrence of a major wound complication did not affect disease recurrence or survival. For all patients, 3-year local control was 94%, and overall survival was 72%. Conclusions: The rates of wound complications and secondary operations in this study were very similar to previously published results. We were not able to demonstrate a significant relationship between the involvement of plastic surgery and the rate of wound complications, although there was a trend toward reduced secondary operations when plastic surgery was involved in the initial operation. Wound complications were manageable and did not compromise outcomes.

Wound Complications in Preoperatively Irradiated Soft-Tissue Sarcomas of the Extremities

International Nuclear Information System (INIS)

Rosenberg, Lewis A.; Esther, Robert J.; Erfanian, Kamil; Green, Rebecca; Kim, Hong Jin; Sweeting, Raeshell; Tepper, Joel E.

2013-01-01

Purpose: To determine whether the involvement of plastic surgery and the use of vascularized tissue flaps reduces the frequency of major wound complications after radiation therapy for soft-tissue sarcomas (STS) of the extremities. Methods and Materials: This retrospective study evaluated patients with STS of the extremities who underwent radiation therapy before surgery. Major complications were defined as secondary operations with anesthesia, seroma/hematoma aspirations, readmission for wound complications, or persistent deep packing. Results: Between 1996 and 2010, 73 patients with extremity STS were preoperatively irradiated. Major wound complications occurred in 32% and secondary operations in 16% of patients. Plastic surgery closed 63% of the wounds, and vascularized tissue flaps were used in 22% of closures. When plastic surgery performed closure the frequency of secondary operations trended lower (11% vs 26%; P=.093), but the frequency of major wound complications was not different (28% vs 38%; P=.43). The use of a vascularized tissue flap seemed to have no effect on the frequency of complications. The occurrence of a major wound complication did not affect disease recurrence or survival. For all patients, 3-year local control was 94%, and overall survival was 72%. Conclusions: The rates of wound complications and secondary operations in this study were very similar to previously published results. We were not able to demonstrate a significant relationship between the involvement of plastic surgery and the rate of wound complications, although there was a trend toward reduced secondary operations when plastic surgery was involved in the initial operation. Wound complications were manageable and did not compromise outcomes.

Is It Possible to Detect Activated Brown Adipose Tissue in Humans Using Single-Time-Point Infrared Thermography under Thermoneutral Conditions? Impact of BMI and Subcutaneous Adipose Tissue Thickness.

Directory of Open Access Journals (Sweden)

Sergios Gatidis

Full Text Available To evaluate the feasibility to detect activated brown adipose tissue (BAT using single-time-point infrared thermography of the supraclavicular skin region under thermoneutral conditions. To this end, infrared thermography was compared with 18-F-FDG PET, the current reference standard for the detection of activated BAT.120 patients were enrolled in this study. After exclusion of 18 patients, 102 patients (44 female, 58 male, mean age 58±17 years were included for final analysis. All patients underwent a clinically indicated 18F-FDG-PET/CT examination. Immediately prior to tracer injection skin temperatures of the supraclavicular, presternal and jugular regions were measured using spatially resolved infrared thermography at room temperature. The presence of activated BAT was determined in PET by typical FDG uptake within the supraclavicular adipose tissue compartments. Local thickness of supraclavicular subcutaneous adipose tissue (SCAT was measured on CT. Measured skin temperatures were statistically correlated with the presence of activated BAT and anthropometric data.Activated BAT was detected in 9 of 102 patients (8.8%. Local skin temperature of the supraclavicular region was significantly higher in individuals with active BAT compared to individuals without active BAT. However, after statistical correction for the influence of BMI, no predictive value of activated BAT on skin temperature of the supraclavicular region could be observed. Supraclavicular skin temperature was significantly negatively correlated with supraclavicular SCAT thickness.We conclude that supraclavicular SCAT thickness influences supraclavicular skin temperature and thus makes a specific detection of activated BAT using single-time-point thermography difficult. Further studies are necessary to evaluate the possibility of BAT detection using alternative thermographic methods, e.g. dynamic thermography or MR-based thermometry taking into account BMI as a confounding factor.

Post-irradiation diarrhea

International Nuclear Information System (INIS)

Meerwaldt, J.H.

1984-01-01

In radiotherapy of pelvic cancers, the X-ray dose to be delivered to the tumour is limited by the tolerance of healthy surrounding tissue. In recent years, a number of serious complications of irradiation of pelvic organs were encountered. Modern radiotherapy necessitates the acceptance of a calculated risk of complications in order to achieve a better cure rate. To calculate these risks, one has to know the radiation dose-effect relationship of normal tissues. Of the normal tissues most at risk when treating pelvic tumours only the bowel is studied. In the literature regarding post-irradiation bowel complications, severe and mild complications are often mixed. In the present investigation the author concentrated on the group of patients with relatively mild symptoms. He studied the incidence and course of post-irradiation diarrhea in 196 patients treated for carcinoma of the uterine cervix or endometrium. The aims of the present study were: 1) to determine the incidence, course and prognostic significance of post-irradiation diarrhea; 2) to assess the influence of radiotherapy factors; 3) to study the relation of bile acid metabolism to post-irradiation diarrhea; 4) to investigate whether local factors (reservoir function) were primarily responsible. (Auth.)

Total body irradiation: current indications; L`irradiation corporelle totale: les indications actuelles

Energy Technology Data Exchange (ETDEWEB)

Giraud, P.; Danhier, S.; Dubray, B.; Cosset, J.M. [Institut Curie, 75 - Paris (France)

1998-05-01

The choice of dose and fractionation for total body irradiation is made difficult by the large number of considerations to be taken into account. The outcome of bone marrow transplantation after total body irradiation can be understood in terms of tumor cell killing, engraftment, and normal tissue damage, each of these endpoints being influenced by irradiation-, disease-, transplant-, and patient- related factors. Interpretation of clinical data is further hampered by the overwhelming influence of logistic constraints, the small numbers of randomized studies, and the concomitant variations in total dose and fraction size or dose rate. So far, three cautious conclusions can be drawn in order to tentatively adapt the total body irradiation schedule to clinically-relevant situations. Firstly, the organs at risk for normal tissue damage (lung, liver, lens, kidney) are protected by delivering small doses per fraction at low dose rate. This suggests that, when toxicity is at stake (e.g. in children), fractionated irradiation should be preferred, provided that inter-fraction intervals are long enough. Secondly, fractionated irradiation should be avoided in case of T-cell depleted transplant, given the high risk of graft rejection in this setting. An alternative would be to increase total (or fractional) dose of fractionated total body irradiation, but this approach is likely to induce more normal tissue toxicity. Thirdly, clinical data have shown higher relapse rates in chronic myeloid leukemia after fractionated or low dose rate total body irradiation, suggesting that fractionated irradiation should not be recommended, unless total (or fractional) dose is increased. Total body irradiation-containing regimens, primarily cyclophosphamide / total body irradiation, are either equivalent to or better than the chemotherapy-only regimens, primarily busulfan / cyclophosphamide. Busulfan / cyclophosphamide certainly represents a reasonable alternative, especially in patients who

Does the ratio and thickness of prevertebral soft tissue provide benefit in blunt cervical spine injury?

Science.gov (United States)

Shiau, J-P; Chin, C-C; Yeh, C-N; Chen, J-F; Lee, S-T; Fang, J-F; Liao, C-C

2013-06-01

Although many reports advocate computed tomography (CT) as the initial surveillance tool for occult cervical spine injury (CSI) at the emergency department (ED), the role of a lateral cervical spine radiograph (LCSX) has still not been replaced. We hypothesized that the increased width of the prevertebral soft tissue on an LCSX provides helpful information for selecting the high-risk patients who need to be evaluated with more accurate diagnostic tools. This was a retrospective and consecutive series of injured patients requiring cervical spine evaluation who were first imaged with three-view plain films at the ED. The prevertebral soft tissue thickness (PVST) and ratio of prevertebral soft tissue thickness to the cervical vertebrae diameter (PVST ratio) were calculated on the LCSX. Suspicion of CSI was confirmed by either CT or magnetic resonance imaging (MRI) scans. A total of 826 adult trauma patients requiring cervical spine evaluation were enrolled. The C3 PVST and PVST ratio were significantly different between patients with or without upper cervical area injury (UCAI, 8.64 vs. 5.49 mm, and 0.394 vs. 0.276, respectively), and, likewise, the C6 PVST and PVST ratio for patients with or without lower cervical area injury (LCAI, 16.89 vs. 14.66 mm, and 0.784 vs. 0.749, respectively). The specificity was greater than 90 % in predicting UCAI and LCAI when combining these two parameters. This method maximizes the usefulness of LCSX during the initial assessment of a conscious patient with blunt head and neck injury, especially for the identification of high-risk patients requiring prompt CT or MRI; on the other hand, it prevents the overuse of these high-cost imaging studies as initial diagnostic tools.

Acute Ultraviolet Radiation Perturbs Epithelialization but not the Biomechanical Strength of Full-thickness Cutaneous Wounds

DEFF Research Database (Denmark)

Danielsen, Patricia L; Lerche, Catharina M; Wulf, Hans Christian

2016-01-01

SED, 3 SED and 5 SED. Twenty-four hours after UV irradiation, inflammation was quantified by skin reflectance (erythema) and myeloperoxidase (MPO) tissue levels, and two 6 mm full-thickness excisional wounds and one 3 cm incisional wound were inflicted. Epidermal hyperplasia was assessed...... (P epithelial coverage decreased (P = 0.024) by increasing the UVR dose, whereas there was no significant difference (P = 0.765) in wound MPO levels. Neither wound width (P = 0.850) nor breaking strength (P...... = 0.320) differed among the groups. Solar-simulated UVR 24 h before wounding impaired epithelialization but was not detrimental for surgical incisional wound healing....

Study of the agroindustrial alterations induced by the irradiated tissue culture in sugar cane, variety NA 56-79

International Nuclear Information System (INIS)

Figueiredo Junior, O.

1991-01-01

The use of plant tissue culture and the application of gamma radiation as mutation inducing agents, in the sugar cane plant, variety NA 5679, are studied. The variation in the contents of brix, pol, fiber, purity, extraction, phosphorus, nitrogen, reducing sugars as well as the morphological characteristics are analysed. The 'callus' obtained by the tissue culture were irradiated with 20, 40, and 60 Gy doses. The statistical analysis indicated that the method of tissue culture may, eventually, increase the contents of the technological parameters and the dosages of gamma radiation were not efficient for such purpose. (M.A.C.)

Computer-based anthropometrical system for total body irradiation.

Science.gov (United States)

Sánchez-Nieto, B; Sánchez-Doblado, F; Terrón, J A; Arráns, R; Errazquin, L

1997-05-01

For total body irradiation (TBI) dose calculation requirements, anatomical information about the whole body is needed. Despite the fact that video image grabbing techniques are used by some treatment planning systems for standard radiotherapy, there are no such systems designed to generate anatomical parameters for TBI planning. The paper describes an anthropometrical computerised system based on video image grabbing which was purpose-built to provide anatomical data for a PC-based TBI planning system. Using software, the system controls the acquisition and digitalisation of the images (external images of the patient in treatment position) and the measurement procedure itself (on the external images or the digital CT information). An ASCII file, readable by the TBI planning system, is generated to store the required parameters of the dose calculation points, i.e. depth, backscatter tissue thickness, thickness of inhomogeneity, off-axis distance (OAD) and source to skin distance (SSD).

Viability of acid-fast bacilli from γ- and UV-irradiated lepromatous armadillo tissues infected with mycobacterium leprae

International Nuclear Information System (INIS)

Dastidar, S.G.; Chakraborty, A.N.

1992-01-01

γ-irradiated splenic homogenates of armadillos infected with M. leprae proved sterile by conventional tests and media. However, on media for chemoautotrophy, these could repeatedly grow as a single type of acid-fast nocardioform bacterium like the unirradiated specimens, although with a much reduced count. In the slide culture, transition from the initial acid-fast bacilli (AFB)/coccoid bodies, to sporulating mycelia and granules in the final stage, could be observed sequentially. The γ-irradiated tissue specimens failed to yield any other mycobacterium/corynebacterium tested according to standard protocols. (author). 26 refs., 2 tabs., 1 fig

Improvement of polyethylene by irradiation in artificial joints

International Nuclear Information System (INIS)

Oonishi, H.; Takayama, Y.

1992-01-01

The decrease in socket thickness of several total hip prostheses was measured on X-ray film. The following prostheses were compared: (1) SOM ''28 mm metal head and an ultra-high-molecular-weight-polyethylene (UHMWPE) socket irradiated with 10 8 rad of γ-radiation'', (2) T-28 ''28 mm metal head and a UHMWPE socket not irradiated'', (3) Bioceram ''28 mm alumina head and UHMWPE not irradiated'' and (4) irradiated Bioceram ''28 mm alumina head and UHMWPE socket irradiated with 10 8 rad of γ-radiation''. The average steady state wear rate of SOM, T-28, Bioceram and irradiated Bioceram were 0.076, 0.247, 0.098 and 0.072 mm/year, respectively. The weight bearing portion of the irradiated socket presented a clearly-outlined and irregular pattern of about 0.1 μm thickness having a smooth ripple surface. The scratch and holding phenomenon characteristic of non-irradiated sockets was not observed at all. In our experimental tests using an IS sliding wear test machine, the wear measured as decrease of thickness was smallest at 10 8 rad, although there was an increase in the coefficient of friction. Our experimental and clinical findings suggest that the best total hip prosthesis at present is one with an alumina head and a UHMWPE socket irradiated with 10 8 rad of γ-radiation. (author)

Dose characterization of the rad sourceTM 2400 X-ray irradiator for oyster pasteurization

International Nuclear Information System (INIS)

Wagner, Jennifer Koop; Dillon, Jeff A.; Blythe, Eugene K.; Ford, John R.

2009-01-01

The RS 2400's cylindrical X-ray source yields dose rates high enough to allow the irradiator to replace widely used gamma irradiators. Except for the leftmost 5 cm, beam uniformity is within 10% at the tube surface. At maximum operating parameters, the beam has HVL 1 =13.66 mm aluminum, HC=0.47, and hν eq =88.5 keV. Maximum dose rates to tissue are 65 Gy min -1 ±3.1% at tube surface, 37 Gy min -1 ±3.1% at center of canisters, 14.1 Gy min -1 ±6.5% for thin-shelled oysters, and 12.3 Gy min -1 ±6.2% for thick-shelled oysters

Comparison on the production of radionuclides in 1.4 GeV proton irradiated LBE targets of different thickness

CERN Document Server

Maiti, Moumita; Mendonça, Tania M; Stora, Thierry; Lahiri, Susanta

2014-01-01

This is the first report on the inventory of radionuclides produced in 1.4 GeV proton induced reaction on Lead-Bismuth Eutectic (LBE) targets. LBE targets of 6 mm diameter and 1 to 8 mm lengths were irradiated with 1.4 GeV protons. The radionuclides ranging from Be-7 (53.12 days) to Po-207 (5.8 h) were identified in the samples with the help of time resolved gamma-ray spectroscopy. However, there is no signature of formation of At radioisotopes, which can be produced by the interaction of secondary particles, typical for thick targets.

Surface functionalization by fine ultraviolet-patterning of nanometer-thick liquid lubricant films

International Nuclear Information System (INIS)

Lu, Renguo; Zhang, Hedong; Komada, Suguru; Mitsuya, Yasunaga; Fukuzawa, Kenji; Itoh, Shintaro

2014-01-01

Highlights: • We present fine UV-patterning of nm-thick liquid films for surface functionalization. • The patterned films exhibit both a morphological pattern and a functional pattern of different surface properties. • The finest pattern linewidth was 0.5 μm. • Fine patterning is crucial for improving surface and tribological properties. - Abstract: For micro/nanoscale devices, surface functionalization is essential to achieve function and performance superior to those that originate from the inherent bulk material properties. As a method of surface functionalization, we dip-coated nanometer-thick liquid lubricant films onto solid surfaces and then patterned the lubricant films with ultraviolet (UV) irradiation through a photomask. Surface topography, adhesion, and friction measurements demonstrated that the patterned films feature a concave–convex thickness distribution with thicker lubricant in the irradiated regions and a functional distribution with lower adhesion and friction in the irradiated convex regions. The pattern linewidth ranged from 100 to as fine as 0.5 μm. The surface functionalization effect of UV-patterning was investigated by measuring the water contact angles, surface energies, friction forces, and depletion of the patterned, as-dipped, and full UV-irradiated lubricant films. The full UV-irradiated lubricant film was hydrophobic with a water contact angle of 102.1°, and had lower surface energy, friction, and depletion than the as-dipped film, which was hydrophilic with a water contact angle of 80.7°. This demonstrates that UV irradiation substantially improves the surface and tribological properties of the nanometer-thick liquid lubricant films. The UV-patterned lubricant films exhibited superior surface and tribological properties than the as-dipped film. The water contact angle increased and the surface energy, friction, and depletion decreased as the pattern linewidth decreased. In particular, the 0.5-μm patterned lubricant

High-resolution and high sensitivity mesoscopic fluorescence tomography based on de-scanning EMCCD: System design and thick tissue imaging applications

Science.gov (United States)

Ozturk, Mehmet Saadeddin

Optical microscopy has been one of the essential tools for biological studies for decades, however, its application areas was limited to superficial investigation due to strong scattering in live tissues. Even though advanced techniques such as confocal or multiphoton methods have been recently developed to penetrate beyond a few hundreds of microns deep in tissues, they still cannot perform in the mesoscopic regime (millimeter scale) without using destructive sample preparation protocols such as clearing techniques. They provide rich cellular information; however, they cannot be readily employed to investigate the biological processes at larger scales. Herein, we will present our effort to establish a novel imaging approach that can quantify molecular expression in intact tissues, well beyond the current microscopy depth limits. Mesoscopic Fluorescence Molecular Tomography (MFMT) is an emerging imaging modality that offers unique potential for the non-invasive molecular assessment of thick in-vitro and in-vivo live tissues. This novel imaging modality is based on an optical inverse problem that allows for retrieval of the quantitative spatial distribution of fluorescent tagged bio-markers at millimeter depth. MFMT is well-suited for in-vivo subsurface tissue imaging and thick bio-printed specimens due to its high sensitivity and fast acquisition times, as well as relatively large fields of view. Herein, we will first demonstrate the potential of this technique using our first generation MFMT system applied to multiplexed reporter gene imaging (in-vitro) and determination of Photodynamic Therapy (PDT) agent bio-distribution in a mouse model (in-vivo). Second, we will present the design rationale, in silico benchmarking, and experimental validation of a second generation MFMT (2GMFMT) system. We will demonstrate the gain in resolution and sensitivity achieved due to the de-scanned dense detector configuration implemented. The potential of this novel platform will be

Application of the ultrasound hyperthermia model for a multi-layered tissue system

International Nuclear Information System (INIS)

Loerincz, A

2004-01-01

This work models the thermal effect of several planar transducers targeting the tumour interactively in a ceramics-coupling-skin-muscle-tumour system. The most important inputs of the model include the following: emitted electric output, J/s; mechanical efficiency, %; number of transducers, pieces; surface area of the transducer, m 2 ; area, m 2 and temperature, K of the cooling surface, attenuation coefficients, Np/cm MHz; specific heats, J/gK; densities, g/cm 3 ; heat conductivities, J/msK; sound velocities m/s; flow rate of blood in the tissues, ml/gtissue/min; sound path in the tissues and in the blood flowing through the tissues, m. From the inputs, a number of intermediate data are determined, e.g. the geometry of the irradiated bodies that are in the path of ultrasound, acoustic hardness, Pas/m; sound reflection and sound transmission occurring at the interfaces, Np; heat exchanger wall thickness of the irradiated bodies, m; heat dissipation and heat exchanger surface areas, m 2 ; flow rate of blood in the tissues located in the path of ultrasound, ml/tissue mass in g/min; and the sound attenuation of the tissues, Np. The amount of generated heat, K/s decreased by the heat energy transported, J/s to the surrounding tissues by blood and heat conductivity, and the actual temperature, K of the irradiated tissue are the output parameters calculated by the model. The output results are available in the form of functions. The expected temperature of the target area, K can be set to either the denaturation temperature or to the respiratory decomposition temperature (43.5 deg. C) without damaging the surrounding tissues by setting in the following parameters properly: electric output power, W; the number and surface area, m 2 of the transducers; the area, m 2 and temperature, K of the cooling surfaces. After further development, the model will be suitable for handling more than three tissue layers, increased blood flow rates different angles of incidence, and

Hassall's corpuscles in the guinea-pig thymus after 60Co 2000R local irradiation

International Nuclear Information System (INIS)

Kinoshita, Hideo; Sugiyama, Shizuyuki; Shibata, Moritoshi; Ishibashi, Hirofumi; Uehara, Masaomi

1974-01-01

The cervical regions of male guinea pigs weighing about 300g were irradiated locally with 60 Co 2000 R and the animals were sacrificed on the 3rd, 5th, 7th and 9th days after the irradiation. The thymus was weighed and fixed in 10% formal saline. Tissues were blocked in paraffin and each block was cut into serial sections having a thickness of approximately 6 microns. These sections were stained by the haematoxylin-eosin (HE) and the aldehyde-fuchsin (AF) techniques. The size of Hassall's corpuscles was measured in the sections stained with haematoxylin-eosin and it was found that the weight of the thymus in 60 Co 2000 R irradiation decreased remarkably and that the tendency of Hassall's corpuscles to enlarge was more remarkable in the 2000 R group than in the 800 R group. (author)

Neuropathological changes following experimental stereotactic irradiation. Progressive injuries of oligodendrocytes

International Nuclear Information System (INIS)

Ohtsuka, Takashi; Seiki, Yoshikatsu; Nakano, Jiro; Shibata, Iekado; Terao, Hideo

1997-01-01

This report describes the results of neuropathological examinations in 14 rabbit brains after 100 Gy of linear stereotactic irradiation. The tissue around the area of radiation necrosis was subjected to special examination. Fourteen rabbits were given a single dose of 100 Gy by a linear accelerator with a use of the 10 mm collimator. Animals were sacrificed serially after irradiation. Brains were removed and formalin treated paraffin sections were made. All sections were stained by H and E, GFAP and TUNEL (TdT-mediated dUTP-biotin nick end labeling method) stain. Pathological changes of vessels and neural tissue around the area of necrosis were examined. Three months after irradiation, TUNEL-positive oligodendrocytes were seen scattered in the white matter or the radiated field, and after 6 months, these changes extended around the radiating field, but vessels and neurons appeared to be intact. Two years after irradiation, massive necrosis had occurred in the radiated area. Thickness and fibrinoid degeneration of the vessel walls were evident in the area around the necrosis. These vessel changes were recognized in the zone of the 40 Gy radiated region. TUNEL-positive oligodendrocytes were also observed around the necrosis, and were scattered in the white matter and corpus callosum over the region of vascular changes. These findings suggested the following: In the later period after irradiation, oligodendrocytes in the peripheral zone of necrosis are damaged by ischemia and edema, which are caused by vascular changes. TUNEL-positive oligodendrocytes which exsisted in the white matter and corpus callosum distal to the radiated area may exhibit development of serial damage of oligodendrocytes in those regions. (author)

Cost evaluation of irradiation system with electron accelerator

International Nuclear Information System (INIS)

Kashiwagi, M.

2003-01-01

The features of electron beam irradiation system using electron accelerator are direct energy pour into the irradiated material, no third material mixture such as catalyst, suitable for mass production and easy operation and maintenance work available. These features can bring the various applications such as cross-linking action, graft polymerization, radical polymerization and others. The selection of electron accelerator ratings is made under consideration of quality, width and thickness of irradiated material, production amount, dose required for reaction and irradiation atmosphere. Especially in a case of irradiation of wire with high insulation material such as polyethylene, the consideration of maximum thickness toward irradiation direction is necessary to avoid the discharge (Lichtenberg discharge) by charged-up electrons inside insulation material. Therefore, the acceleration voltage should be selected to make the maximum penetration larger than maximum irradiation thickness. The actual model case of estimate the irradiation cost was selected that the irradiation object was polyethylene insulated wire up to AWG no.14, irradiation amount was 5,000 km/month, necessary dose was 200 kGy, operation time was 22 d/month and 8 h/day and actual operation efficiency was considered loss time such as bobbin changing as 80%. The selected ratings of electron accelerator were acceleration voltage of 800 kV, beam current of 100 mA and irradiation width of 180 cm with irradiation pulleys stand of 60 turns x 3 lanes. The initial total cost was estimated as 3 M$(US) and operation cost was evaluated as 215 k$(US). Therefore, the irradiation cost of wire was evaluated as 0.0036 $/m. (author)

SU-E-T-92: Achieving Desirable Lung Doses in Total Body Irradiation Based On in Vivo Dosimetry and Custom Tissue Compensation

International Nuclear Information System (INIS)

Cui, G; Shiu, A; Zhou, S; Cui, J; Ballas, L

2015-01-01

Purpose: To achieve desirable lung doses in total body irradiation (TBI) based on in vivo dosimetry and custom tissue compensation. Methods: The 15 MV photon beam of a Varian TrueBeam STx linac was used for TBI. Patients were positioned in the lateral decubitus position for AP/PA treatment delivery. Dose was calculated using the midpoint of the separation distance across the patient’s umbilicus. Patients received 200 cGy twice daily for 3 days. The dose rate at the patient’s midplane was approximately 10 cGy/min. Cerrobend blocks with a 5-HVL thickness were used for the primary lung shielding. A custom styrofoam holder for rice-flour filled bags was created based on the lung block cutouts. This was used to provide further lung shielding based on in vivo dose measurements. Lucite plates and rice-flour bags were placed in the head, neck, chest, and lower extremity regions during the treatment to compensate for the beam off-axis output variations. Two patients were included in the study. Patients 1 and 2 received a craniospinal treatment (1080 cGy) and a mediastinum treatment (2520 cGy), respectively, before the TBI. During the TBI nanoDot dosimeters were placed on the patient skin in the forehead, neck, umbilicus, and lung regions for dose monitoring. The doses were readout immediately after the treatment. Based on the readings, fine tuning of the thickness of the rice-flour filled bags was exploited to achieve the desirable lung doses. Results: For both patients the mean lung doses, which took into consideration all treatments, were controlled within 900 +/−10% cGy, as desired. Doses to the forehead, neck, and umbilicus were achieved within +/−10% of the prescribed dose (1200 cGy). Conclusion: A reliable and robust method was developed to achieve desirable lung doses and uniform body dose in TBI based on in vivo dosimetry and custom tissue compensator

SU-E-T-92: Achieving Desirable Lung Doses in Total Body Irradiation Based On in Vivo Dosimetry and Custom Tissue Compensation

Energy Technology Data Exchange (ETDEWEB)

Cui, G; Shiu, A; Zhou, S; Cui, J; Ballas, L [Univ Southern California, Los Angeles, CA (United States)

2015-06-15

Purpose: To achieve desirable lung doses in total body irradiation (TBI) based on in vivo dosimetry and custom tissue compensation. Methods: The 15 MV photon beam of a Varian TrueBeam STx linac was used for TBI. Patients were positioned in the lateral decubitus position for AP/PA treatment delivery. Dose was calculated using the midpoint of the separation distance across the patient’s umbilicus. Patients received 200 cGy twice daily for 3 days. The dose rate at the patient’s midplane was approximately 10 cGy/min. Cerrobend blocks with a 5-HVL thickness were used for the primary lung shielding. A custom styrofoam holder for rice-flour filled bags was created based on the lung block cutouts. This was used to provide further lung shielding based on in vivo dose measurements. Lucite plates and rice-flour bags were placed in the head, neck, chest, and lower extremity regions during the treatment to compensate for the beam off-axis output variations. Two patients were included in the study. Patients 1 and 2 received a craniospinal treatment (1080 cGy) and a mediastinum treatment (2520 cGy), respectively, before the TBI. During the TBI nanoDot dosimeters were placed on the patient skin in the forehead, neck, umbilicus, and lung regions for dose monitoring. The doses were readout immediately after the treatment. Based on the readings, fine tuning of the thickness of the rice-flour filled bags was exploited to achieve the desirable lung doses. Results: For both patients the mean lung doses, which took into consideration all treatments, were controlled within 900 +/−10% cGy, as desired. Doses to the forehead, neck, and umbilicus were achieved within +/−10% of the prescribed dose (1200 cGy). Conclusion: A reliable and robust method was developed to achieve desirable lung doses and uniform body dose in TBI based on in vivo dosimetry and custom tissue compensator.

In vitro assessment of the composition and microhardness of hard tissues of oral cavity submitted to gamma irradiation

International Nuclear Information System (INIS)

Paredes, Wilber Edison Bernaola

2017-01-01

Clinical Radiotherapy is extremely important for the treatment of malignant lesions of the head and neck region, however, exposure to ionizing radiation can lead to systemic or local complications during and after radiation treatment. Among these immediate local complications are the oral cavity xerostomia and the consequent oral mucositis. Regarding late complications produced by radiation, tooth decay of radiation and osteoradionecrosis are included, which are considered dose-dependent lesions, with high incidence in recent decades and difficult to manage, although these appear after completion of treatment and under the influence of local factors. The methodology proposed in this study consists in evaluating the effect of gamma radiation after irradiation of the samples, using the dose used in patients suffering with head and neck cancer. The samples were obtained from human enamel and root dentin; and swine mandibular bone, which were previously polished, and then submitted to the analysis of the initial surface microhardness of all groups. Subsequently, the samples were irradiated in a dose rate of 4 Gy per day, completing a total dose of 72 Gy. Finally, the samples were submitted to surface microhardness analysis after irradiation, which presented statistically significant results from the Student t, ANOVA and Tukey statistical tests referred to the difference of the mean of the initial and final values of each study group with a significant value of p = 0.00 (<0.05). Regarding the morphological analysis in scanning electron microscopy (SEM), the deleterious effect of gamma irradiation was evidenced as structural cracks, breaks and superficial fractures of the analyzed tissues and the biochemical analysis by Attenuated Total Reflection technique using Fourier transform infrared spectroscopy (ATR - FTIR) showed degradation of inorganic components and denaturation of organic compounds; whereby, the effect of gamma irradiation on the hard tissues of the oral

Dose characterization of the rad source{sup TM} 2400 X-ray irradiator for oyster pasteurization

Energy Technology Data Exchange (ETDEWEB)

Wagner, Jennifer Koop [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843-3133 (United States)], E-mail: jenkoop@gmail.com; Dillon, Jeff A. [Experimental Seafood Processing Laboratory, Mississippi State University, Pascagoula, MS 39567 (United States); Blythe, Eugene K. [Coastal Research and Extension Center, Mississippi State University, South Mississippi Branch Experiment Station, Poplarville, MS 39470 (United States); Ford, John R. [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843-3133 (United States)

2009-02-15

The RS 2400's cylindrical X-ray source yields dose rates high enough to allow the irradiator to replace widely used gamma irradiators. Except for the leftmost 5 cm, beam uniformity is within 10% at the tube surface. At maximum operating parameters, the beam has HVL{sub 1}=13.66 mm aluminum, HC=0.47, and h{nu}{sub eq}=88.5 keV. Maximum dose rates to tissue are 65 Gy min{sup -1}{+-}3.1% at tube surface, 37 Gy min{sup -1}{+-}3.1% at center of canisters, 14.1 Gy min{sup -1}{+-}6.5% for thin-shelled oysters, and 12.3 Gy min{sup -1}{+-}6.2% for thick-shelled oysters.

Construction of tissue compensating filters for extended areas in Hodgkin-irradiation on the basis of moire topography

International Nuclear Information System (INIS)

Binder, W.; Cabaj, A.; Kaercher, K.H.; Windischbauer, G.; Tieraerztliche Hochschule, Vienna

1977-01-01

In order to obtain a homogeneous distribution of the dose over extended fields in radiotherapy of Hodgkin's disease, for an exact dose within the irradiated region it is necessary to consider the topography of the patient. The skin protective build-up effect due to the use of bolus materials would be lost with telecobalt irradiation, and therefore tissue compensating filters with a large surface are to be preferred. A simple method of making such filters by means of the moire topography is described. The way to obtain a compensation filter for extended areas is demonstrated by an example showing how to construct it from layered lead plates. (orig./HP) [de

Effect of taurine on the insuline secretion isolated by the pancreatic tissue of intact and irradiated rats

International Nuclear Information System (INIS)

Dokshina, G.A.; Silaeva, T.Yu.

1976-01-01

The whole-body irradiation of rats (700 rads) inhibits the secretory activity of insular pancreatic tissue. Administration of taurine (200 mg/kg), on the fifth day after irradiation, five times every second day normalizes the secretory function of pancreatic islands. In the experiments in vitro, taurine (1.5 and 3.0 mg/ml) stimulated hormone secretion. The stimulating action of the amino acid manifests itself when β-receptors are blocked by obsidane (0.5 μg/ml). It is suggested that insuline secretion by β-cells of pancreas is restored and enhanced by taurine not merely through the adenylatecyclase system; other ways are also possible

Effect of taurine on the insuline secretion isolated by the pancreatic tissue of intact and irradiated rats

Energy Technology Data Exchange (ETDEWEB)

Dokshina, G A; Silaeva, T Yu [Tomskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Biologii i Biofiziki

1976-05-01

The whole-body irradiation of rats (700 rads) inhibits the secretory activity of insular pancreatic tissue. Administration of taurine (200 mg/kg), on the fifth day after irradiation, five times every second day normalizes the secretory function of pancreatic islands. In the experiments in vitro, taurine (1.5 and 3.0 mg/ml) stimulated hormone secretion. The stimulating action of the amino acid manifests itself when ..beta..-receptors are blocked by obsidane (0.5 ..mu..g/ml). It is suggested that insuline secretion by ..beta..-cells of pancreas is restored and enhanced by taurine not merely through the adenylatecyclase system; other ways are also possible.

Uncertainty in stratiform cloud optical thickness inferred from pyranometer measurements at the sea surface

Directory of Open Access Journals (Sweden)

Anna Rozwadowska

2004-06-01

Full Text Available The relative "plane-parallel" error in a mean cloud optical thickness retrieved from ground-based pyranometer measurements is estimated. The plane-parallel error is defined as the bias introduced by the assumption in the radiative transfer model used in cloud optical thickness retrievals that the atmosphere, including clouds, is horizontally homogeneous on the scale of an individual retrieval. The error is estimated for the optical thickness averaged over the whole domain, which simulates the mean cloud optical thickness obtained from a time series of irradiance measurements. The study is based on 3D Monte Carlo radiative transfer simulations for non-absorbing, all-liquid, layer clouds. Liquid water path distributions in the clouds are simulated by a bounded cascade fractal model. The sensitivity of the error is studied with respect to the following factors: averaging time of irradiance used in an individual retrieval, mean cloud optical thickness, cloud variability, cloud base height and solar zenith angle. In the simulations presented in this paper, the relative bias in the domain averaged cloud optical thickness retrieved from pyranometer measurements varies from +1% for optically thin clouds to nearly -20%. The highest absolute value of the relative bias is expected for thick and variable clouds with high bases (e.g. 1 km and retrievals based on long-term mean irradiances (averaging time of the order of several tens of minutes or hours. The bias can be diminished by using short-term irradiance averages, e.g. of one minute, and by limiting retrievals to low-level clouds.

Influence of γ-irradiation on drying of slice potato

International Nuclear Information System (INIS)

Wang Jun; Chao Yan; Fu Junjie; Wang Jianping

2001-01-01

A new technology is introduced to dry food products by hot-air after pretreated by irradiation. The influence of different dosage of irradiation, temperature of hot air, thickness of the slice potato on the rate of dehydration temperature of irradiated potato were studied. A conclusion is reached that the 3 factors, irradiation dosage, hot-air temperature and thickness of slice potato, affect the rate of dehydration and temperature of slice potato. The higher the dosage is, the greater the rate of dehydration of potato becomes, and the higher the temperature of the slice potato gets. (authors)

Effects of hyperthermia and X-irradiation on mouse stromal tissue

International Nuclear Information System (INIS)

Wondergem, J.; Haveman, J.

1986-01-01

The sensitivity of normal stroma to heat, irradiation and heat combined with irradiation, was studied using the tumour bed effect (TBE) assay. Irradiation before implantation led to a TBE, dose dependent below 15 Gy, but remaining relatively constant above. The interval (0-90 days) between irradiation and tumour implantation did not influence the magnitude of the TBE. Hyperthermia with large heat doses (45-60 min at 44 0 C) before implantation may lead to a TBE. The interval between hyperthermia and tumour implantation was very important. Results showed that the recovery from heat-induced stromal damage is very rapid. When the interval between hyperthermia and tumour implantation was 10 days or longer, no TBE could be observed. Irradiation combined with large heat doses (30-60 min at 44 0 C) decreased the radiation-induced TBE. The combination of irradiation with mild heat treatments (15 min at 44 0 C) could lead to a larger TBE then after irradiation alone. When hyperthermia was given prior to irradiation, the interval between heat and irradiation proved to be very important. With large intervals (21 days or longer), TBE values were about the same as with irradiation alone. When heat was given after irradiation, irradiation-induced TBE was always reduced. (UK)

Hassall's corpuscles in the guinea-pig thymus after /sup 60/Co 2000R local irradiation

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, H; Sugiyama, S; Shibata, M; Ishibashi, H; Uehara, M [Nara Medical Univ., Kashihara (Japan)

1974-12-01

The cervical regions of male guinea pigs weighing about 300g were irradiated locally with /sup 60/Co 2000 R and the animals were sacrificed on the 3rd, 5th, 7th and 9th days after the irradiation. The thymus was weighed and fixed in 10% formal saline. Tissues were blocked in paraffin and each block was cut into serial sections having a thickness of approximately 6 microns. These sections were stained by the haematoxylin-eosin (HE) and the aldehyde-fuchsin (AF) techniques. The size of Hassall's corpuscles was measured in the stained sections and it was found that the weight of the thymus in /sup 60/Co 2000 R irradiation decreased remarkably and that the tendency of Hassall's corpuscles to enlarge was greater in the 2000 R group than in the 800 R group.

Antioxidant Approaches to Management of Ionizing Irradiation Injury

Directory of Open Access Journals (Sweden)

Joel Greenberger

2015-01-01

Full Text Available Ionizing irradiation induces acute and chronic injury to tissues and organs. Applications of antioxidant therapies for the management of ionizing irradiation injury fall into three categories: (1 radiation counter measures against total or partial body irradiation; (2 normal tissue protection against acute organ specific ionizing irradiation injury; and (3 prevention of chronic/late radiation tissue and organ injury. The development of antioxidant therapies to ameliorate ionizing irradiation injury began with initial studies on gene therapy using Manganese Superoxide Dismutase (MnSOD transgene approaches and evolved into applications of small molecule radiation protectors and mitigators. The understanding of the multiple steps in ionizing radiation-induced cellular, tissue, and organ injury, as well as total body effects is required to optimize the use of antioxidant therapies, and to sequence such approaches with targeted therapies for the multiple steps in the irradiation damage response.

The effect of continuous low dose-rate gamma irradiation on cell population kinetics of lymphoid tissue

Science.gov (United States)

Foster, B. R.

1974-01-01

Cellular response and cell population kinetics were studied during lymphopoiesis in the thymus of the mouse under continuous gamma irradiation using autoradiographic techniques and specific labeling with tritiated thymidine. On the basis of tissue weights, it is concluded that the response of both the thymus and spleen to continuous low dose-rate irradiation is multiphasic. That is, alternating periods of steady state growth, followed by collapse, which in turn is followed by another period of homeostasis. Since there are two populations of lymphocytes - short lived and long-lived, it may be that different phases of steady state growth are mediated by different lymphocytes. The spleen is affected to a greater extent with shorter periods of steady-state growth than exhibited by the thymus.

Testicular dose and associated risk from inverted-Y field irradiation in patients with Hodgkin's disease.

Science.gov (United States)

Mazonakis, Michalis; Kokona, Georgiana; Damilakis, John; Varveris, Haris; Gourtsoyiannis, Nicholas

This study aims to estimate testicular dose and the associated risks for infertility and hereditary effects from inverted-Y field irradiation Radiotherapy was simulated on a humanoid phantom using a 6 MV photon beam. Testicular dose was measured for various field sizes and tissue thicknesses along beam axis using an ionization chamber. Gonadal dose was reduced by placing lead cups around the testes supplemented by a field edge block. For a tumor dose of 40 Gy, testicular dose was 0.56-6.52 Gy depending upon the field size and the distance from the inferior field edge. The corresponding dose to shielded testes was 0.12-1.96 Gy. The increase of tissue thickness in reased the testicular dose up to 40%. An excess risk of hereditary disorders of (7-391) per 10000 births was calculated. The treatment parameters, the presence of gonad shield and the somatometric characteristics determine whether testicular dose can exceed 1 Gy which allows a complete recovery of spermatogenesis.

Cryogen spray cooling during laser tissue welding.

Science.gov (United States)

Fried, N M; Walsh, J T

2000-03-01

Cryogen cooling during laser tissue welding was explored as a means of reducing lateral thermal damage near the tissue surface and shortening operative time. Two centimetre long full-thickness incisions were made on the epilated backs of guinea pigs, in vivo. India ink was applied to the incision edges then clamps were used to appose the edges. A 4 mm diameter beam of 16 W, continuous-wave, 1.06 microm, Nd:YAG laser radiation was scanned over the incisions, producing approximately 100 ms pulses. There was a delay of 2 s between scans. The total irradiation time was varied from 1-2 min. Cryogen was delivered to the weld site through a solenoid valve in spurt durations of 20, 60 and 100 ms. The time between spurts was either 2 or 4 s, corresponding to one spurt every one or two laser scans. Histology and tensile strength measurements were used to evaluate laser welds. Total irradiation times were reduced from 10 min without surface cooling to under 1 min with surface cooling. The thermal denaturation profile showed less denaturation in the papillary dermis than in the mid-dermis. Welds created using optimized irradiation and cooling parameters had significantly higher tensile strengths (1.7 +/- 0.4 kg cm(-2)) than measured in the control studies without cryogen cooling (1.0 +/- 0.2 kg cm(-2)) (p laser welding results in increased weld strengths while reducing thermal damage and operative times. Long-term studies will be necessary to determine weld strengths and the amount of scarring during wound healing.

Identification of radiation response genes and proteins from mouse pulmonary tissues after high-dose per fraction irradiation of limited lung volumes.

Science.gov (United States)

Jin, Hee; Jeon, Seulgi; Kang, Ga-Young; Lee, Hae-June; Cho, Jaeho; Lee, Yun-Sil

2017-02-01

The molecular effects of focal exposure of limited lung volumes to high-dose per fraction irradiation (HDFR) such as stereotactic body radiotherapy (SBRT) have not been fully characterized. In this study, we used such an irradiation system and identified the genes and proteins after HDFR to mouse lung, similar to those associated with human therapy. High focal radiation (90 Gy) was applied to a 3-mm volume of the left lung of C57BL6 mice using a small-animal stereotactic irradiator. As well as histological examination for lungs, a cDNA micro array using irradiated lung tissues and a protein array of sera were performed until 4 weeks after irradiation, and radiation-responsive genes and proteins were identified. For comparison, the long-term effects (12 months) of 20 Gy radiation wide-field dose to the left lung were also investigated. The genes ermap, epb4.2, cd200r3 (up regulation) and krt15, hoxc4, gdf2, cst9, cidec, and bnc1 (down-regulation) and the proteins of AIF, laminin, bNOS, HSP27, β-amyloid (upregulation), and calponin (downregulation) were identified as being responsive to 90 Gy HDFR. The gdf2, cst9, and cidec genes also responded to 20 Gy, suggesting that they are universal responsive genes in irradiated lungs. No universal proteins were identified in both 90 Gy and 20 Gy. Calponin, which was downregulated in protein antibody array analysis, showed a similar pattern in microarray data, suggesting a possible HDFR responsive serum biomarker that reflects gene alteration of irradiated lung tissue. These genes and proteins also responded to the lower doses of 20 Gy and 50 Gy HDFR. These results suggest that identified candidate genes and proteins are HDFR-specifically expressed in lung damage induced by HDFR relevant to SBRT in humans.

Metabolic Profiling of Somatic Tissues from Monochamus alternatus (Coleoptera: Cerambycidae Reveals Effects of Irradiation on Metabolism

Directory of Open Access Journals (Sweden)

Liangjian Qu

2014-06-01

Full Text Available A high-level of sexual sterility is of importance for the sterile insect technique (SIT. However, the use of high-dose-intensity gamma radiation to induce sterility has negative impacts not only on reproductive cells but also on somatic cells. In this study, we investigated the metabolite differences in somatic tissues between non-irradiated, 20-Gy-irradiated, and 40-Gy-irradiated male Monochamus alternatus, an important vector of the pathogenic nematode, Bursaphelenchus xylophilus, which kills Asian pines. The results showed that metabolite levels changed moderately in the 20-Gy samples but were markedly altered in the 40-Gy samples compared with the non-irradiated samples. Twenty-six and 53 metabolites were disturbed by 20-Gy and 40-Gy radiation, respectively. Thirty-six metabolites were found to be markedly altered in the 40-Gy samples but were not changed significantly in the 20-Gy samples. The comprehensive metabolomic disorders induced by 40-Gy radiation dysregulated six metabolic pathways involved in the life process. The findings presented in this manuscript will contribute to our knowledge of the characteristic metabolic changes associated with gamma-radiation-induced damage to somatic cells and will allow for better exploration of the SIT for the control of this target pest.

Effects of x-irradiation on steroid biotransformations by testicular tissue. Progress report, August 1, 1974--July 31, 1975

International Nuclear Information System (INIS)

Ellis, L.C.

1975-01-01

X irradiation of rat testicular tissue either in vivo or in vitro labilized the lysosomal membranes with a release of both acid phosphatase and phospholipase A 2 resulting in an increased lipid peroxidation. The results from these investigations suggest that the lipid endoperoxides and malonaldehyde are responsible for mediating the effects of radiation on steroid biotransformations. Estradiol, testosterone, 5α-dihydrotestosterone, prolactin, acetylcholine, cGMP, H 2 O 2 , PUFA, ethanol and vitamin A increased lysosomal fragility and initiated enzyme release while ATP, cAMP, vitamin E, theophylline, indomethacin, caffeine, cortisol, epinephrine, NADPH, NDGA, FSH and Zn ++ decreased both phenomena. An increase in catalase activity was consistently observed after irradiation and by cAMP indicative of an increase in testicular cAMP content following irradiation. Seminiferous tubules were found to be dependent on prostaglandins for their contractions. (U.S.)

The influence of combined treatment of Cd, and γ-irradiation on DNA damage and repair in lymphoid tissues of mice

International Nuclear Information System (INIS)

Privezentsev, K.V.; Sirota, N.P.; Gaziev, A.I.

1996-01-01

The effect of combined treatment of Cd and γ-irradiation on DNA damage and repair was studied in lymphoid tissues of mice using single-cell gel assay. Single i.p. injection of CdCl 2 (1 mg Cd/kg body wt), 2 h prior to irradiation resulted in increasing of DNA lesions in peripheral blood lymphocytes (PBL) when compared to non-injected animals. However, the same treatment, 48 h prior to irradiation is shown to decrease DNA damage in PBL and splenocytes in comparison with untreated mice. In thymocytes maximal protective effect of Cd was determined when mice were irradiated in 24 h after injection. The protective effect observed is due to decreasing of initial level of DNA damage in thymocytes as well as acceleration of DNA repair in PBL and splenocytes. 28 refs.; 2 figs

Qualitative and quantitative histological changes in ewe oviduct and uterus after X irradiation

International Nuclear Information System (INIS)

Stanikova, A.; Maracek, I.; Arendarcik, J.; Balun, J.; Praslicka, M.

1980-01-01

Experiments were performed to study changes in the epithelium of the oviduct and surface epithelium of the endometrium and endometrial glands of ewes of the Slovak Merino breed after irradiation of the hypothalamo-hypophysial region at a dose of 516.5 mC.kg -1 (2000 R) and after direct exposure of the ovaries to 64.4 mC.kg -1 (250 R); prior to this, the ewes had been laparotomized. The symptoms of irradiation included multiplication of pale cells, an increased occurrence of the subnuclear vacuolization of the surface epithelium, and similar vacuolization in the secretory cells of the endometrial glands. Irradiation of the ovaries induces a marked occurrence of round cells. Irradiation of the head caused a significant increase in the thickness of the epithelium on the border between the infundibulum and the ampulla as well as at the site where the ampulla passes into the isthmus. The thickness of the oviduct epithelium remained unchanged after the irradiation of the ovaries, in comparison with the control group. It was found by a quantitative microscopic analysis that the thickness of surface epithelium did not show any marked changes after irradiation. On the other hand, the thickness of the secretory cells of the endometrial glands changed significantly in both experimental groups of ewes. The change in endometrial thickness was decribed; the change was more significant after irradiation of the ovaries than after irradiation of the hypothalamo-hypophysial region. (author)

Development of the tissues of the ovule of Capsicum annum L. after irradiation during early embryogenesis

Energy Technology Data Exchange (ETDEWEB)

Ilieva, I.; Zagorska, N. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Genetika)

1983-01-01

The interrelation between the embryo, the endosperm and the other tissues of the ovule during the late stages of embryogenesis was surveyed. Observations in vivo were carried out on seeds of C. annum, Gold Medal variety, after irradiation with 0,5; 1,0 and 1,5 krad during the stages of middle and late proembryo. A trend was observed towards higher sensitivity of the endothelium (necrosis vacuolization, etc.), compared with the remaining tissues of the ovule whose destructive changes are not as marked. Most probably the endothelium and the endosperm, which make the connection between the mother organism and the embryo, serve as a kind of filters retaining the metabolites harmful to the embryo.

Development of the tissues of the ovule of Capsicum annum L. after irradiation during early embryogenesis

International Nuclear Information System (INIS)

Ilieva, I.; Zagorska, N.

1983-01-01

The interrelation between the embryo, the endosperm and the other tissues of the ovule during the late stages of embryogenesis was surveyed. Observations in vivo were carried out on seeds of C. annum, Gold Medal variety, after irradiation with 0,5; 1,0 and 1,5 krad during the stages of middle and late proembryo. A trend was observed towards higher sensitivity of the endothelium (necrosis vacuolization, etc.), compared with the remaining tissues of the ovule whose destructive changes are not as marked. Most probably the endothelium and the endosperm, which make the connection between the mother organism and the embryo, serve as a kind of filters retaining the metabolites harmful to the embryo

Study on lethal effect on cells by determination of 10B in biological tissues and (n, α) reaction

International Nuclear Information System (INIS)

Ishida, Masahiro; Tsuruta, Takao; Takagaki, Masao

1980-01-01

As for the macroscopic distribution in tissues and microscopic distribution in cells of 10 B administrated to patients, which are important in thermal neutron capture therapy, it is difficult to say that the method of quantitative determination has been established. The authors tried some experiments by solid state track detection for the determination. That is, the trial determinations of boron in cells by solution method (wet process), filter paper method (dry process) and the method using an electron microscope are reported. If the maximum thermal neutron fluence available is assumed to be 10 14 /cm 2 and the minimum detectable surface density of etch pits is 10 4 /cm 2 , the detection limit of 10 B concentration is estimated as about 10 -2 μg/ml either in the solution method or in the filter paper method. In the quantitative determination of boron distribution at cell level with an electron microscope, a sample of tissue was covered with a plastic thin film, etched after the irradiation with thermal neutrons, and the tissue and the thin film were simultaneously observed with the transmission electron microscope. The thin film thickness of about 0.1 μm is suitable for the sliced tissue of about 0.1 μm thick. The existence of fast neutrons at the time of thermal neutron irradiation causes the generation of etch pits by recoiled particles in celluloid, and increases background counts, while γ-dose above 10 6 rad leads to the deterioration of celluloid composition. Some automatic methods of counting etch pits under consideration are described. (Wakatsuki, Y.)

Revascularization of autogenous skin grafts placed on irradiated tissue

International Nuclear Information System (INIS)

Ueda, M.; Torii, S.; Kaneda, T.; Oka, T.

1982-01-01

Vascular changes in rat skin after irradiation were examined microangiographically. Revascularization of the skin transplanted during the chronic stage after irradiation was also studied. The results obtained through these examinations revealed higher vascular densities at the acute and the subacute stages, and low values at the chronic stages compared with those of the control. Furthermore, when the skin grafts were transplanted to the irradiated beds in the chronic stage, primary revascularization was scant, and the inhibited capillary proliferation in the recipient sites prevented new vessel penetration. This explains why grafts transplanted to previously irradiated beds fail to survive

Dose-dependent induction of transforming growth factor β (TGF-β) in the lung tissue of fibrosis-prone mice after thoracic irradiation

International Nuclear Information System (INIS)

Ruebe, Claudia E.; Uthe, Daniela; Schmid, Kurt W.; Richter, Klaus D.; Wessel, Jan; Schuck, Andreas; Willich, Norman; Ruebe, Christian

2000-01-01

Purpose: The lung is the major dose-limiting organ for radiotherapy of cancer in the thoracic region. The pathogenesis of radiation-induced lung injury at the molecular level is still unclear. Immediate cellular damage after irradiation is supposed to result in cytokine-mediated multicellular interactions with induction and progression of fibrotic tissue reactions. The purpose of this investigation was to evaluate the acute and long-term effects of radiation on the gene expression of transforming growth factor beta (TGF-β) in a model of lung injury using fibrosis-sensitive C57BL/6 mice. Methods and Materials: The thoraces of C57BL/6 mice were irradiated with 6 and 12 Gy, respectively. Treated and sham-irradiated control mice were sacrificed at times corresponding to the latent period (1, 3, 6, 12, 24, 48, 72 hours and 1 week postirradiation), the pneumonic phase (2, 4, 8, and 16 weeks postirradiation), and the beginning of the fibrotic phase (24 weeks postirradiation). The lung tissue from three different mice per dosage and time point was analyzed by a combination of polymerase chain reaction (PCR), immunohistochemistry, and light microscopy. The mRNA expression of TGF-β was quantified by competitive reverse transcriptase/polymerase chain reaction (RT-PCR); the cellular origin of the TGF-β protein was identified by immunohistochemical staining (alkaline phosphatase-anti-alkaline phosphatase [APAAP]). The cytokine expression on mRNA and protein level was correlated with the histopathological alterations. Results: Following thoracic irradiation with a single dose of 12 Gy, radiation-induced TGF-β release in lung tissue was appreciable already within the first hours (1, 3, and 6 hours postirradiation) and reached a significant increase after 12 hours; subsequently (48 hours, 72 hours, and 1 week postirradiation) the TGF-β expression declined to basal levels. At the beginning of the pneumonic phase, irradiation-mediated stimulation of TGF-β release reached

Phase-changes in cell cycle of wound tissue irradiated with 5.21 Gy soft X-rays

International Nuclear Information System (INIS)

Liu Jianzhong; Zhou Yuanguo; Cheng Tianmin; Zhou Ping; Liu Xia; Li Ping

2002-01-01

Objective: To study the phase-changes in cell cycle of wound tissue which was locally irradiated with 5.21 Gy soft X-rays. Methods: Flow cytometry and PI staining were used to analyze cell cycle. Cell proliferation was determined with BrdU labeling. Results: During 3-9 days after irradiation, the percentage of the G 0 /G 1 phase cells in wound of the control side decreased while the percentage of S phase cells increased and reached the highest value on day 9. The percentage of G 2 /M phase cells also increased, and reached its peak on day 15. The percentage of G 0 /G 1 phase cell increased in wound of the irradiation side and was higher than that of the control wound, meanwhile the percentages of S and G 2 /M cells were significantly lower than those of the control wound. In the period of 12-22 days after wounding, the percentage of S phase cells increased and reached its peak value on the 22 th day. When most of cells were in S phase and arrested dramatically. Through the whole healing process, the percentage of G 2 /M in wound of the irradiation side was lower than that of the non-irradiated wound. The BrdU-positive cells were fibroblasts, endothelial cells and smooth muscle cells. Conclusion: These results suggest that G 1 block, S phase arrest, and switch of G 2 /M with suppression of mitotic activity of these cells are induced by local 5.21 Gy soft X-ray irradiation. Therefore, wound healing delay is induced partly by cell cycle arrest

Effects of buffer thickness on ATW blanket performance

International Nuclear Information System (INIS)

Yang, W. S.; Mercatali, L.; Taiwo, T. A.; Hill, R. N.

2001-01-01

This paper presents preliminary results of target and buffer design studies for liquid metal cooled accelerator transmutation of waste (ATW) systems, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using 840 MWt liquid metal cooled ATW designs, the effects of buffer thickness on the blanket performance have been studied. Varying the buffer thickness for a given blanket configuration, system performance parameters have been estimated by a series of calculations using the MCNPX and REBUS-3 codes. The effects of source importance variation are studied by investigating the low-energy ( and lt; 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. For investigating irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. Results for the liquid-metal-cooled designs show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable. Investigation of the impact of the proton beam energy on the target and buffer design shows that for a given blanket power level, a lower beam energy (0.6 GeV versus 1 GeV) results in a higher irradiation damage to the beam window. This trend occurs because of the increase in the beam intensity required to maintain the power level

Effects of Buffer Thickness on ATW Blanket Performance

International Nuclear Information System (INIS)

Yang, W.S.; Mercatali, L.; Taiwo, T.A.; Hill, R.N.

2002-01-01

This paper presents preliminary results of target and buffer design studies for liquid metal cooled accelerator transmutation of waste (ATW) systems, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using 840 MWt liquid metal cooled ATW designs, the effects of buffer thickness on the blanket performance have been studied. Varying the buffer thickness for a given blanket configuration, system performance parameters have been estimated by a series of calculations using the MCNPX and REBUS-3 codes. The effects of source importance variation are studied by investigating the low-energy (< 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. For investigating irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. Results for the liquid-metal-cooled designs show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable. Investigation of the impact of the proton beam energy on the target and buffer design shows that for a given blanket power level, a lower beam energy (0.6 GeV versus 1 GeV) results in a higher irradiation damage to the beam window. This trend occurs because of the increase in the beam intensity required to maintain the power level. (authors)

Biological Activity Alterations of Human Amniotic Membrane Pre and Post Irradiation Tissue Banking.

Science.gov (United States)

Nemr, Waleed; Bashandy, A S; Araby, Eman; Khamiss, O

Innate immunity of Human Amniotic Membrane (HAM) and its highly active secretome that rich with various types of growth factors and anti-inflammatory substances proposed it as a promising material for many medical studies and applications. This study evaluate the biological activity of cultivated HAM pre and post tissue banking process in which freeze-dried HAM was sterilized by 25 KGray (kGy) dose of γ radiation. The HAM's antimicrobial activity, viability, growth of isolated human amniotic epithelial cells (HAECs), hematopoietic stimulation of co-cultivated murine bone marrow cells (mammalian model), scaffold efficiency for fish brain building up (non-mammalian model) and self re-epithelialization after trypsin denuding treatment were examined as supposed biological activity features. Native HAM revealed viability indications and was active to kill all tested microorganisms; 6 bacterial species (3 Gram-positive and 3 Gram-negative) and Candida albicans as a pathogenic fungus. Also, HAM activity promoted colony formation of murine hematopoietic cells, Tilapia nilotica brain fragment building-up and self re-epithelialization after trypsin treatment. In contrary, radiation-based tissue banking of HAM caused HAM cellular death and consequently lacked almost all of examined biological activity features. Viable HAM was featured with biological activity than fixed HAM prepared by irradiation tissue banking.

Effects of buffer thickness on ATW blanket performances

International Nuclear Information System (INIS)

Yang, Won Sik

2001-01-01

This paper presents the preliminary results of target and buffer design studies for a lead-bismuth eutectic (LBE) cooled accelerator transmutation of waste (ATW) system, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using an 840 MWt LBE cooled ATW design, the effects of buffer thickness on the blanket performances have been studied. Varying the buffer thickness for a given blanket configuration, system performances have been estimated by a series of calculations using MCNPX and REBUS-3 codes. The effects of source importance change are studied by investigating the low-energy (< 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. As the irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. The results show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable

Light gradients and optical microniches in coral tissues

Directory of Open Access Journals (Sweden)

Daniel eWangpraseurt

2012-08-01

Full Text Available Light quantity and quality are among the most important factors determining the physiology and stress response of zooxanthellate corals. Yet, almost nothing is known about the light field that Symbiodinium experiences within their coral host, and the basic optical properties of coral tissue are unknown. We used scalar irradiance microprobes to characterise vertical and lateral light gradients within and across tissues of several coral species. Our results revealed the presence of steep light gradients with PAR (photosynthetically available radiation decreasing by about one order of magnitude from the tissue surface to the coral skeleton. Surface scalar irradiance was consistently higher over polyp tissue than over coenosarc tissue in faviid corals. Coral bleaching increased surface scalar irradiance by ~150% (between 500-700 nm relative to a healthy coral. Photosynthesis peaked around 300 µm within the tissue, which corresponded to a zone exhibiting strongest depletion of scalar irradiance. Deeper coral tissue layers, e.g. ~1000 µm into aboral polyp tissues, harbor optical microniches, where only ~10% of the incident irradiance remains. We conclude that the optical microenvironment of corals exhibits strong lateral and vertical gradients of scalar irradiance, which are affected by both tissue and skeleton optical properties. Our results imply that zooxanthellae populations inhabit a strongly heterogeneous light environment and highlight the presence of different optical microniches in corals; an important finding for understanding the photobiology, stress response, as well as the phenotypic and genotypic plasticity of coral symbionts.

Effect of MgSO4 on expression of NSE and S-100 in rats brain tissue irradiated by 6 MeV electron beam

International Nuclear Information System (INIS)

Zhou Juying; Wang Lili; Yu Zhiying; Qin Songbing; Xu Xiaoting; Li Li; Tu Yu

2007-01-01

Objective: To explore the protection of magnesium sulfate (MgSO 4 ) on radiation-induced acute brain injuries. Methods: Thirty six mature Sprague-Dawley rats were randomly divided into 3 groups: blank control group, experimental control group and experimental administered group. The whole brain of SD rats of experimental control group and experimental-therapeutic group were irradiated with a dose of 20 Gy using 6 MeV electron beam. Magnesium sulfate was injected intraperitoneally into the rats of experimental-therapeutic group before and after irradiation for five times. The brain tissue were taken on days 1, 7, 14 and 30 after irradiation. Immunohistochemical method was used to detect the expressions of NSE and S-100 in brain tissue. All data were processed statistically with One-ANOVA analysis. Results: The expressions of NSE and S-100 after whole brain irradiation were time-dependent. Compared with blank control group, the expression of NSE in brains of experimental control group decreased significantly (P 4 can inhibit the expression of S-100, but induce the expression of NSE on radiation-induced acute brain injury. MgSO 4 has a protective effect on radiation-induced acute brain injury. (authors)

GC and GC-MS studies of the effects of gamma-irradiation on olive oil and chicken skin tissue fat

International Nuclear Information System (INIS)

Tuominen, J.; Kiutamo, T.; Sjoeberg, A.M.; Leinonen

1991-01-01

Reduction of the microbial cell count in a frozen packaged chicken by ionizing radiation is an advantageous method with a microbiologically optimum dose of 4 kGy (5). However, the detection of irradiation in poultry is a problem in food analysis. Our study focused on to the possible changes in the fatty acid composition and formation of long-chain hydrocarbons in the chicken fat. The composition of chicken fat is complex. Therefore, our study was started with some pure fatty acids and a vegetable oil consisting mainly of triglycerides of fatty acids and having, qualitatively, the same fatty acids as the chicken. Pure olive oil (a retail oil from Italy) was chosen for the purpose. Later, also fat extracted from chicken skin was analysed. All samples were analysed as irradiated and non-irradiated. The results show that no new radiolytically induced fatty acids or other related compounds could be detected by using a BP-21 polar capillary column and flame ionization detector. Moreover, the composition of the major fatty acids remained constant. In the qualitative analysis of hydrocarbons produced by irradiation, it was shown that there is a distinct difference in the hydrocarbon pattern between non-irradiated and irradiated chicken skin tissues. (5 figs, 2 tabs, 6 refs)

Improvement of potato tolerance to salinity using tissue culture techniques and irradiation with in vitro selection

International Nuclear Information System (INIS)

Al-Safadi, B.; Arabi, M. I. E.

2006-01-01

A mutation breeding program was conducted to improve potato (Solanum tuberosum) tolerance to salinity. In vitro cultured explants from potato cvs. Draga, Diamant, Spunta were irradiated with gamma doses 25, 30, and 35 Gy. Mutants were isolated to get rid of chimeral tissues and subsequently propagated for in vitro and pot selection pressure. Cultivar Sponta produced the highest number of tolerant plants (4) and only one plant was obtained from Diamant. (authors)

Photothermal effects of laser tissue soldering

International Nuclear Information System (INIS)

McNally, K.M.; Sorg, B.S.; Welch, A.J.; Dawes, J.M.; Owen, E.R.

1999-01-01

Low-strength anastomoses and thermal damage of tissue are major concerns in laser tissue welding techniques where laser energy is used to induce thermal changes in the molecular structure of the tissues being joined, hence allowing them to bond together. Laser tissue soldering, on the other hand, is a bonding technique in which a protein solder is applied to the tissue surfaces to be joined, and laser energy is used to bond the solder to the tissue surfaces. The addition of protein solders to augment tissue repair procedures significantly reduces the problems of low strength and thermal damage associated with laser tissue welding techniques. Investigations were conducted to determine optimal solder and laser parameters for tissue repair in terms of tensile strength, temperature rise and damage and the microscopic nature of the bonds formed. An in vitro study was performed using an 808 nm diode laser in conjunction with indocyanine green (ICG)-doped albumin protein solders to repair bovine aorta specimens. Liquid and solid protein solders prepared from 25% and 60% bovine serum albumin (BSA), respectively, were compared. The efficacy of temperature feedback control in enhancing the soldering process was also investigated. Increasing the BSA concentration from 25% to 60% greatly increased the tensile strength of the repairs. A reduction in dye concentration from 2.5mgml -1 to 0.25mgml -1 was also found to result in an increase in tensile strength. Increasing the laser irradiance and thus surface temperature resulted in an increased severity of histological injury. Thermal denaturation of tissue collagen and necrosis of the intimal layer smooth muscle cells increased laterally and in depth with higher temperatures. The strongest repairs were produced with an irradiance of 6.4Wcm -2 using a solid protein solder composed of 60% BSA and 0.25mgml -1 ICG. Using this combination of laser and solder parameters, surface temperatures were observed to reach 85±5 deg. C with a

Analysis on the post-irradiation examination of the HANARO miniplate-1 irradiation test for Kijang research reactor

Energy Technology Data Exchange (ETDEWEB)

Park, Jong Man; Tahk, Young Wook; Jeong, Yong Jin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); and others

2017-08-15

The construction project of the Kijang research reactor (KJRR), which is the second research reactor in Korea, has been launched. The KJRR was designed to use, for the first time, U–Mo fuel. Plate-type U–7 wt.% Mo/Al–5 wt.% Si, referred to as U–7Mo/Al–5Si, dispersion fuel with a uranium loading of 8.0 gU/cm{sup 3}, was selected to achieve higher fuel efficiency and performance than are possible when using U{sub 3}Si{sub 2}/Al dispersion fuel. To qualify the U–Mo fuel in terms of plate geometry, the first miniplates [HANARO Miniplate (HAMP-1)], containing U–7Mo/Al–5Si dispersion fuel (8 gU/cm{sup 3}), were fabricated at the Korea Atomic Energy Research Institute and recently irradiated at HANARO. The PIE (Post-irradiation Examination) results of the HAMP-1 irradiation test were analyzed in depth in order to verify the safe in-pile performance of the U–7Mo/Al–5Si dispersion fuel under the KJRR irradiation conditions. Nondestructive analyses included visual inspection, gamma spectrometric mapping, and two-dimensional measurements of the plate thickness and oxide thickness. Destructive PIE work was also carried out, focusing on characterization of the microstructural behavior using optical microscopy and scanning electron microscopy. Electron probe microanalysis was also used to measure the elemental concentrations in the interaction layer formed between the U–Mo kernels and the matrix. A blistering threshold test and a bending test were performed on the irradiated HAMP-1 miniplates that were saved from the destructive tests. Swelling evaluation of the U–Mo fuel was also conducted using two methods: plate thickness measurement and meat thickness measurement.

Analysis on the post-irradiation examination of the HANARO miniplate-1 irradiation test for kijang research reactor

Directory of Open Access Journals (Sweden)

Jong Man Park

2017-08-01

Full Text Available The construction project of the Kijang research reactor (KJRR, which is the second research reactor in Korea, has been launched. The KJRR was designed to use, for the first time, U–Mo fuel. Plate-type U–7 wt.% Mo/Al–5 wt.% Si, referred to as U–7Mo/Al–5Si, dispersion fuel with a uranium loading of 8.0 gU/cm3, was selected to achieve higher fuel efficiency and performance than are possible when using U3Si2/Al dispersion fuel. To qualify the U–Mo fuel in terms of plate geometry, the first miniplates [HANARO Miniplate (HAMP-1], containing U–7Mo/Al–5Si dispersion fuel (8 gU/cm3, were fabricated at the Korea Atomic Energy Research Institute and recently irradiated at HANARO. The PIE (Post-irradiation Examination results of the HAMP-1 irradiation test were analyzed in depth in order to verify the safe in-pile performance of the U–7Mo/Al–5Si dispersion fuel under the KJRR irradiation conditions. Nondestructive analyses included visual inspection, gamma spectrometric mapping, and two-dimensional measurements of the plate thickness and oxide thickness. Destructive PIE work was also carried out, focusing on characterization of the microstructural behavior using optical microscopy and scanning electron microscopy. Electron probe microanalysis was also used to measure the elemental concentrations in the interaction layer formed between the U–Mo kernels and the matrix. A blistering threshold test and a bending test were performed on the irradiated HAMP-1 miniplates that were saved from the destructive tests. Swelling evaluation of the U–Mo fuel was also conducted using two methods: plate thickness measurement and meat thickness measurement.

Radiological changes of bones and soft tissues after irradiation therapy in patients with Wilms' tumor and neuroblastoma

Energy Technology Data Exchange (ETDEWEB)

Hirose, Hiroaki; Okabe, Ikuo

1989-04-01

Late effects of tele cobalt 60 therapy on bones and soft tissues were studied radiologically in 24 patients with neuroblastoma and Wilms' tumor. The degree of changes in spinal bodies was influenced by the dose of irradiation as well as the age of patients at the time of irradiation. In patients who had 15 to 19 Gy of irradiation at the ages under one year old, a moderate to severe degree of changes was observed. Many patients showed atrophies of iliac bone, ribs, and erector spinae and psoas muscles on the side of the irradiation. In patients who were equal to or over 12 y.o. at the time of the examination, the degree of atrophy of erector spinae muscles on the side of the irradiation was greater than that of the patients who were less than 12 y.o.. Scoliosis was observed in 71% of patients and it had a tendency to aggravate at puberty. Because there was a significant correlation between the degree of scoliosis and the severity of the atrophic erector spinae muscle, the latter was thought to contribute much to the development of the former. At present, all patients are living with no limitation of their daily activities and no one needs medical care. (author).

Studies on the use of gamma irradiation and tissue culture in improving brassica napus

International Nuclear Information System (INIS)

Khedr, E.K.A.

2012-01-01

The objectives of this study were to:1- Studying the effect of different doses of gamma rays on some growth and yield component traits of three Brassica napus cultivars (Serow6, Serow4 and Pactol) during four consecutive generations aiming to create new genotypes characterized with high yielding traits. 2- Studying the effect of different doses of gamma rays on in vitro biotechnology technique (tissue culture) used in improving Brassica napus. Seeds of three Brassica napus cultivars were irradiated with different gamma ray doses then sown for four consecutive seasons. Data were collected and recorded to clarify the effect gamma irradiation on some yield component traits which were days to flowering , plant height, number of main branches per plant, number of secondary branches per plant, number of pods per plant, number of seeds per pod, weight of 1000-seed, weight of grain yield/plant and oil content of seeds). Results showed that high doses of gamma radiation had enhanced all of the studied traits for each of the three tested cultivars (except the plant height trait for Serow6 and Pactol cultivars). Seven new mutant lines were selected for their superiority in one or more of the studied yield component traits. Regarding the effect of gamma rays on tissue culture techniques, the applied gamma radiation doses did not affect the percentage of seed germination of the three studied cultivars, whereas the percentage of callus induction decreased by increasing the dose of gamma rays for each of the three cultivars and in both types of explants (hypocotyl and cotyledons) used in this experiment.

Nd:YAG laser irradiation on temporary teeth carious tissue using 12% diamine silver fluoride as a photo-absorber - a morphological study

International Nuclear Information System (INIS)

Calmon, Andrea de Avillez

2001-01-01

Since Nd:YAG laser radiation was first introduced in Dentistry various photo-absorbers were employed with the intent of improving its efficacy when used on dental carious tissue. The purpose of the present study was to analyze the influence of this radiation using Scanning and Optical microscopy over carious tissue of primary teeth using two photo-absorbers. 15 primary human teeth were used and, in each one, 3 cavity preparations were performed. Specimens were then submitted to an in vitro demineralizing environment during 18 days. Two of the cavities of each specimen were laser irradiated using the Nd:YAG laser with 60 mJ of energy per pulse, 10 Hz and average power of 0,6 W. The 12% diamine silver fluoride or the mineral coal were used as photo-absorbers. The third cavity of the specimens was used as a control and received no laser irradiation. Samples were transversally cut and the section analyzed by SEM and OM. Results showed that the 12% diamine silver fluoride is an efficient photo-absorber and, when used it the Nd:YAG laser, leading to melting and resolidification of the carious tissue. It can be concluded that the 12% diammine silver fluoride presents advantages over the mineral coal as a photo absorber when used in primary teeth as it promotes and improves the efficacy of laser irradiation. This substance also works as a barrier on the carie progression in deeper areas such as the infected and necrotic zones. (author)

ion irradiation

Indian Academy of Sciences (India)

Swift heavy ions interact predominantly through inelastic scattering while traversing any polymer medium and produce excited/ionized atoms. Here samples of the polycarbonate Makrofol of approximate thickness 20 m, spin coated on GaAs substrate were irradiated with 50 MeV Li ion (+3 charge state). Build-in ...

Low-dose-rate intraoperative brachytherapy combined with external beam irradiation in the conservative treatment of soft tissue sarcoma

International Nuclear Information System (INIS)

Delannes, M.; Thomas, L.; Martel, P.; Bonnevialle, P.; Stoeckle, E.; Chevreau, Ch.; Bui, B.N.; Daly-Schveitzer, N.; Pigneux, J.; Kantor, G.

2000-01-01

Purpose: Conservative treatment of soft tissue sarcomas most often implies combination of surgical resection and irradiation. The aim of this study was to evaluate low-dose-rate intraoperative brachytherapy, delivered as a boost, in the local control of primary tumors, with special concern about treatment complications. Methods and Materials: Between 1986 and 1995, 112 patients underwent intraoperative implant. This report focuses on the group of 58 patients with primary sarcomas treated by combination of conservative surgery, intraoperative brachytherapy, and external irradiation. Most of the tumors were located in the lower limbs (46/58--79%). Median size of the tumor was 10 cm, most of the lesions being T2-T3 (51/58--88%), Grade 2 or 3 (48/58--83%). The mean brachytherapy dose was 20 Gy and external beam irradiation dose 45 Gy. In 36/58 cases, iridium wires had to be placed on contact with neurovascular structures. Results: With a median follow-up of 54 months, the 5-year actuarial survival was 64.9%, with a 5-year actuarial local control of 89%. Of the 6 patients with local relapse, 3 were salvaged. Acute side effects, essentially wound healing problems, occurred in 20/58 patients, late side effects in 16/58 patients (7 neuropathies G2 to G4). No amputation was required. The only significant factor correlated with early side effects was the location of the tumor in the lower limb (p = 0.003), and with late side effects the vicinity of the tumor with neurovascular structures (p = 0.009). Conclusion: Brachytherapy allows early delivery of a boost dose in a reduced volume of tissue, precisely mapped by the intraoperative procedure. Combined with external beam irradiation, it is a safe and efficient treatment technique leading to high local control rates and limited functional impairment

Reusable bi-directional 3ω sensor to measure thermal conductivity of 100-μm thick biological tissues

Science.gov (United States)

Lubner, Sean D.; Choi, Jeunghwan; Wehmeyer, Geoff; Waag, Bastian; Mishra, Vivek; Natesan, Harishankar; Bischof, John C.; Dames, Chris

2015-01-01

Accurate knowledge of the thermal conductivity (k) of biological tissues is important for cryopreservation, thermal ablation, and cryosurgery. Here, we adapt the 3ω method—widely used for rigid, inorganic solids—as a reusable sensor to measure k of soft biological samples two orders of magnitude thinner than conventional tissue characterization methods. Analytical and numerical studies quantify the error of the commonly used "boundary mismatch approximation" of the bi-directional 3ω geometry, confirm that the generalized slope method is exact in the low-frequency limit, and bound its error for finite frequencies. The bi-directional 3ω measurement device is validated using control experiments to within ±2% (liquid water, standard deviation) and ±5% (ice). Measurements of mouse liver cover a temperature ranging from -69 °C to +33 °C. The liver results are independent of sample thicknesses from 3 mm down to 100 μm and agree with available literature for non-mouse liver to within the measurement scatter.

Surgical effects on soft tissue produced by a 405-nm violet diode laser in vivo

Science.gov (United States)

Miyazaki, H.; Kato, J.; Kawai, S.; Hatayama, H.; Uchida, K.; Otsuki, M.; Tagami, J.; Yokoo, S.

2011-12-01

This study evaluated the surgical performance of a 405-nm diode laser in vivo, using living rat liver tissue. Tissue was incised by irradiation with the laser at low output power ranging from 1 W (722 W/cm2) to 3 W (2165 W/cm2) on a manual control at a rate of 1 mm/s. As a control, incisions using a stainless scalpel were compared. Immediately after operation, the surface of the incisions was macroscopically observed and histopathologically evaluated by microscopy. Laser-ablated liver tissue was smooth with observable signs of remnant carbonization and easily acquired hemostasis. The thickness of the denatured layer increased in proportion to the output power; the coagulation layer did not thicken accordingly. Bleeding could not be stopped for tissues incised with the stainless scalpel. The 405-nm diode laser thus proved to be effective for ablating soft tissue with high hemostatic ability at low power.

Americium-241 use of measurement lead equivalent thickness for medical x-ray room: A review

International Nuclear Information System (INIS)

Mohd Khalid Matori; Husaini Saleh; Abd Aziz Mhd Ramli; Muhammad Jamal Md Isa; Mohd Firdaus Abd Rahman; Zainal Jamaluddin

2010-01-01

Lead equivalent thickness measurement of a shielding material in diagnostic radiology is very important to ensure that requirements for the purpose of radiation protection of patients, employees and the public are met. The Malaysian Ministry of Health (MOH) has established that the irradiation room must have sufficient shielding thickness, for example for general radiography it must be at least equal to 2.0 mm of Pb, for panoramic dental radiography at least equal to 1.5 mm of Pb and for mammography should be a minimum of 1.0 mm of Pb. This paper presents a technique using americium-241 source to test and verify the integrity of the shielding thickness in term of lead equivalent for X-ray room at health centres. Results of measurement of 30 irradiation rooms conducted from 2009 to mid 2010 were analyzed for this presentation. Technical comparison of the attenuation of gamma rays from Am-241 source through the walls of the irradiation room and pieces of lead were used to assess the lead equivalent thickness of the walls. Results showed that 96.7 % of the irradiation rooms tested meet the requirements of the Ministry of Health and is suitable for the installation of the intended diagnostic X-ray apparatus. Some specific positions such as door knobs and locks, electrical plug sockets were identified with potential to not met the required lead equivalent thickness hence may contribute to higher radiation exposure to workers and the public. (author)

Model for thickness dependence of radiation charging in MOS structures

Science.gov (United States)

Viswanathan, C. R.; Maserjian, J.

1976-01-01

The model considers charge buildup in MOS structures due to hole trapping in the oxide and the creation of sheet charge at the silicon interface. The contribution of hole trapping causes the flatband voltage to increase with thickness in a manner in which square and cube dependences are limiting cases. Experimental measurements on samples covering a 200 - 1000 A range of oxide thickness are consistent with the model, using independently obtained values of hole-trapping parameters. An important finding of our experimental results is that a negative interface charge contribution due to surface states created during irradiation compensates most of the positive charge in the oxide at flatband. The tendency of the surface states to 'track' the positive charge buildup in the oxide, for all thicknesses, applies both in creation during irradiation and in annihilation during annealing. An explanation is proposed based on the common defect origin of hole traps and potential surface states.

Assessment of maxillary sinus wall thickness with paranasal sinus digital tomosynthesis and CT

Energy Technology Data Exchange (ETDEWEB)

Byun, Ji Eun; Shim, Sung Shine; Kim, Yoo Kyung; Kong, Kyoung Ae [Mokdong Hospital, Ewha Womans University School of Medicine, Seoul (Korea, Republic of)

2017-05-15

This study was performed to compare paranasal sinus tomosynthesis with computed tomography (CT) imaging as a radiologic tool to evaluate the paranasal sinuses, using measurement of the soft tissue thickness of the maxillary sinus. A total of 114 patients with sinusitis who underwent both paranasal sinus digital tomosynthesis (DT) and CT were enrolled in this retrospective study. Two observers independently assessed soft tissue thickness in both maxillary sinus chambers using both DT and CT images. The mean difference in soft tissue thickness measured by each observer was −0.31 mm on CT and 0.15 mm on DT. The mean differences in soft tissue thickness measured with DT and CT were −0.15 by observer 1 and −0.31 by observer 2. Evaluation of the agreement in measurement of soft tissue thickness in the maxillary sinus using DT and CT showed a high intraclass correlation, with the 95% limit of agreement ranging from −3.36 mm to 3.06 mm [intraclass correlation coefficient (ICC), 0.994: p<0.01] for observer 1 and from −5.56 mm to 4.95 mm (ICC, 0.984: p<0.01) for observer 2. As an imaging tool, DT is comparable to CT for assessing the soft tissue thickness of maxillary sinuses in patients with sinusitis.

Histopathological study of the effects of low-intensity laser irradiation (λ=650 nm) on dental pulp tissue after cavity pre paration

International Nuclear Information System (INIS)

Bertella, Claudio

2001-01-01

The purpose of this study was to evaluate (in vivo) the effects of low-intensity Arsenide Gallium Aluminium laser application post-cavity preparation class 1. Six patients with bilateral pre-molars and molars indicated to extraction for orthodontics aim were selected. Four samples of these teeth underwent cavity preparation with deep from medium to high and two samples underwent cavity preparation from high to pulp expositions. The samples were constituted of two teeth of the same patient and received different treatments. One of the teeth underwent laser exposition and the other one was maintained as control, before restorative procedure with polycarboxylate cement. A diode laser (λ=650 nm), output power 30 mW and fluencies of 1,8 J/cm 2 and 2,7 J/cm 2 in pre-molars and molars, respectively, was used for irradiation with repetition rate of 18 Hz in interrupted continuous wave mode. After seven days, the teeth were extracted and processed histologically with HE to verify morphological changes in the pulpy tissue. The four samples, which cavity preparation and restorative material were not in contact with the pulp, did not show histological differences between irradiated and non-irradiated teeth. Both of them presented the same characteristics of normality. The two samples with exposed pulpy tissue showed different results. The irradiated teeth presented no or slight inflammatory signs when compared to the control samples, which showed abscess in the coronary pulp interior and intense inflammatory infiltrated. These results suggest that the laser irradiation can be used as a therapeutic modality in clinical trials, in the conditions employed in this study. (author)

Effects of hyperthermia and X-irradiation on mouse stromal tissue

NARCIS (Netherlands)

Wondergem, J.; Begg, A. C.; Haveman, J.

1986-01-01

The sensitivity of normal stroma to heat, irradiation and heat combined with irradiation has been studied using the tumour bed effect (TBE) assay. Irradiation before implantation led to a TBE. This TBE was dose dependent below 15 Gy, the TBE remaining relatively constant above 15 Gy. The interval

10 μ m-thick four-quadrant transmissive silicon photodiodes for beam position monitor application: electrical characterization and gamma irradiation effects

Science.gov (United States)

Rafí, J. M.; Pellegrini, G.; Quirion, D.; Hidalgo, S.; Godignon, P.; Matilla, O.; Juanhuix, J.; Fontserè, A.; Molas, B.; Pothin, D.; Fajardo, P.

2017-01-01

Silicon photodiodes are very useful devices as X-ray beam monitors in synchrotron radiation beamlines. Owing to Si absorption, devices thinner than 10 μ m are needed to achieve transmission over 90% for energies above 10 keV . In this work, new segmented four-quadrant diodes for beam alignment purposes are fabricated on both ultrathin (10 μ m-thick) and bulk silicon substrates. Four-quadrant diodes implementing different design parameters as well as auxiliary test structures (single diodes and MOS capacitors) are studied. An extensive electrical characterization, including current-voltage (I-V) and capacitance-voltage (C-V) techniques, is carried out on non-irradiated and gamma-irradiated devices up to 100 Mrad doses. Special attention is devoted to the study of radiation-induced charge build-up in diode interquadrant isolation dielectric, as well as its impact on device interquadrant resistance. Finally, the devices have been characterized with an 8 keV laboratory X-ray source at 108 ph/s and in BL13-XALOC ALBA Synchroton beamline with 1011 ph/s and energies from 6 to 16 keV . Sensitivity, spatial resolution and uniformity of the devices have been evaluated.

Irradiation-injured brain tissues can self-renew in the absence of the pivotal tumor suppressor p53 in the medaka (Oryzias latipes) embryo

International Nuclear Information System (INIS)

Yasuda, Takako; Nagata, Kento; Igarashi, Kento; Watanabe-Asaka, Tomomi; Oda, Shoji; Mitani, Hiroshi; Kimori, Yoshitaka

2016-01-01

The tumor suppressor protein, p53, plays pivotal roles in regulating apoptosis and proliferation in the embryonic and adult central nervous system (CNS) following neuronal injuries such as those induced by ionizing radiation. There is increasing evidence that p53 negatively regulates the self-renewal of neural stem cells in the adult murine brain; however, it is still unknown whether p53 is essential for self-renewal in the injured developing CNS. Previously, we demonstrated that the numbers of apoptotic cells in medaka (Oryzias latipes) embryos decreased in the absence of p53 at 12-24 h after irradiation with 10-Gy gamma rays. Here, we used histology to examine the later morphological development of the irradiated medaka brain. In p53-deficient larvae, the embryonic brain possessed similar vacuoles in the brain and retina, although the vacuoles were much smaller and fewer than those found in wild-type embryos. At the time of hatching (6 days after irradiation), no brain abnormality was observed. In contrast, severe disorganized neuronal arrangements were still present in the brain of irradiated wild-type embryos. Our present results demonstrated that self-renewal of the brain tissue completed faster in the absence of p53 than wild type at the time of hatching because p53 reduces the acute severe neural apoptosis induced by irradiation, suggesting that p53 is not essential for tissue self-renewal in developing brain. (author)

Technique of manufacturing specimen of irradiated fuel rods

International Nuclear Information System (INIS)

Min, Duck Seok; Seo, Hang Seok; Min, Duck Kee; Koo, Dae Seo; Lee, Eun Pyo; Yang, Song Yeol

1999-04-01

Technique of manufacturing specimen of irradiated fuel rods to perform efficient PIE is developed by analyzing the relation between requiring time of manufacturing specimen and manufacturing method in irradiated fuel rods. It takes within an hour to grind 1 mm of specimen thickness under 150 rpm in speed of grinding, 600 g gravity in force using no.120, no.240, no.320 of grinding paper. In case of no.400 of grinding paper, it takes more an hour to grind the same thickness as above. It takes up to a quarter to grind 80-130 μm in specimen thickness using no.400 of grinding paper. When grinding time goes beyond 15 minutes, the grinding thickness of specimen does not exist. The polishing of specimen with 150 Rpms in speed of grinding machine, 600 g gravity in force, 10 minutes in polishing time using diamond paste 15 μm on polishing cloths amounts to 50 μm in specimen thickness. In case of diamond paste 9 μm on polishing cloth, the polishing of specimen amounts to 20 μm. The polishing thickness of specimen with 15 minutes in polishing time using 6 μm, 3 μm, 1 μm, 1/4 μm does not exist. Technique of manufacturing specimen of irradiated fuel rods will have application to the destructive examination of PIE. (author). 6 refs., 1 tab., 10 figs

Experimental study on the effect of x-irradiation in the rat periodontal ligament

International Nuclear Information System (INIS)

Cho, Won Pyo; You, Dong Soo

1980-01-01

The author studied on the effects of X-ray irradiation to the development of periodontal ligament in gestation rats. They were irradiated in their abdomen with 100, 200 and 300 rads respectively in one shot irradiation with deep radiation therapy equipment(MAXIMAR 250-III). In 7th, 14th, 21th and 28th day after delivery, those new born rats were respectively sacrificed with ether anesthesia and removed of their mandibles. After removal, those mandibles were fixed in 10% neutral buffer formalin, decalcified with 5% trichloroacetic acid for 5 days and embedded with paraffin. Staining was performed with H-E, Van Gieson, Mallory azan, Bielshowsky-Gomori silver stain and Halmi's oxytalan fiber stain. The results were as follows: 1. Before tooth eruption, all the fiber components in dental sac were almost always oriented near the outer enamel epithelial layer. But in irradiated new born rats, those collagen fiber orientation was more irregular than those of control groups, and this phenomenon was more severe in proportion to the amount of irradiation in the gestation period. 2. Before tooth eruption, the connective tissue fibers in periodontal ligament were stained with lighter in the irradiated groups than those of control groups. Oxytalan fibers of irradiated groups were thin and splitting pattern of their fiber morphology to compare with those of control groups. 3. After tooth eruption, the periodontal ligament fibers of irradiated groups were oriented functionally and their morphology was thick, fine and heavy staining. Oxytalan fibers were revealed with oblique parallel arrangement in the periodontal ligament of irradiated groups.

Focal exposure of limited lung volumes to high-dose irradiation down-regulated organ development-related functions and up-regulated the immune response in mouse pulmonary tissues.

Science.gov (United States)

Kim, Bu-Yeo; Jin, Hee; Lee, Yoon-Jin; Kang, Ga-Young; Cho, Jaeho; Lee, Yun-Sil

2016-01-27

Despite the emergence of stereotactic body radiotherapy (SBRT) for treatment of medically inoperable early-stage non-small-cell lung cancer patients, the molecular effects of focal exposure of limited lung volumes to high-dose radiation have not been fully characterized. This study was designed to identify molecular changes induced by focal high-dose irradiation using a mouse model of SBRT. Central areas of the mouse left lung were focally-irradiated (3 mm in diameter) with a single high-dose of radiation (90 Gy). Temporal changes in gene expression in the irradiated and non-irradiated neighboring lung regions were analyzed by microarray. For comparison, the long-term effect (12 months) of 20 Gy radiation on a diffuse region of lung was also measured. The majority of genes were down-regulated in the focally-irradiated lung areas at 2 to 3 weeks after irradiation. This pattern of gene expression was clearly different than gene expression in the diffuse region of lungs exposed to low-dose radiation. Ontological and pathway analyses indicated these down-regulated genes were mainly associated with organ development. Although the number was small, genes that were up-regulated after focal irradiation were associated with immune-related functions. The temporal patterns of gene expression and the associated biological functions were also similar in non-irradiated neighboring lung regions, although statistical significance was greatly reduced when compared with those from focally-irradiated areas of the lung. From network analysis of temporally regulated genes, we identified inter-related modules associated with diverse functions, including organ development and the immune response, in both the focally-irradiated regions and non-irradiated neighboring lung regions. Focal exposure of lung tissue to high-dose radiation induced expression of genes associated with organ development and the immune response. This pattern of gene expression was also observed in non-irradiated

Study of human mesenchymal stem cells plasticity into radiation injured tissues in a N.O.D./S.C.I.D. mouse model: therapeutic approach of the multiple organ dysfunction; Etude de la capacite plastique des Cellules Souches Mesenchymateuses humaines (CSM) apres irradiation du tissu receveur: approche therapeutique de l'atteinte multiorgane radio-induite

Energy Technology Data Exchange (ETDEWEB)

Francois, S

2006-01-15

The therapeutic potential of bone marrow-derived human mesenchymal stem cells (h.M.S.C.) has recently been brought into the spotlight of many fields of research. One possible application of the approach is the repair of injured tissues arising from side effects of radiation treatments and accidents. The first challenge in cell therapy is to assess the quality of the cell and the ability to retain their differentiation potential during the expansion process. Efficient delivery to the sites of intended action is also necessary. We addressed both questions using h.M.S.C. cultured and then infused to Non Obese Diabetes/Severe Combined Immunodeficiency (N.O.D./S.C.I.D.) mice submitted to total body irradiation. Further, we tested the impact of additional local irradiation superimposed to total body irradiation (T.B.I.), as a model of accidental irradiation. Our results showed that the h.M.S.C. used for transplant have been expanded without significant loss in their differentiation capacities. After transplantation into adult unconditioned mice, h.M.S.C. not only migrate in bone marrow but also into other tissues. Total body irradiation increased h.M.S.C. implantation in bone marrow and muscle and further led to engraftment in brain, heart, and liver. Local irradiation, in addition to T.B.I., increased both specific homing of injected cells to the injured tissues and to other tissues outside the local irradiation field. M.S.C. may participate to restoration of intestinal homeostasis 3 days post abdominal irradiation. This study suggests that using the potential of h.M.S.C. to home to various organs in response to tissue injuries could be a promising strategy to repair the radiation induced damages. (author)

SEM analysis of enamel surface treated by Er:YAG laser: influence of irradiation distance.

Science.gov (United States)

Souza-Gabriel, A E; Chinelatti, M A; Borsatto, M C; Pécora, J D; Palma-Dibb, R G; Corona, S A M

2008-07-01

Depending on the distance of laser tip to dental surface a specific morphological pattern should be expected. However, there have been limited reports that correlate the Er:YAG irradiation distance with dental morphology. To assess the influence of Er:YAG laser irradiation distance on enamel morphology, by means of scanning electron microscopy (SEM). Sixty human third molars were employed to obtain discs (approximately =1 mm thick) that were randomly assigned to six groups (n=10). Five groups received Er:YAG laser irradiation (80 mJ/2 Hz) for 20 s, according to the irradiation distance: 11, 12, 14, 16, or 17 mm and the control group was treated with 37% phosphoric acid for 15 s. The laser-irradiated discs were bisected. One hemi-disc was separated for superficial analysis without subsequent acid etching, and the other one, received the phosphoric acid for 15 s. Samples were prepared for SEM. Laser irradiation at 11 and 12 mm provided an evident ablation of enamel, with evident fissures and some fused areas. At 14, 16 and 17 mm the superficial topography was flatter than in the other distances. The subsequent acid etching on the lased-surface partially removed the disorganized tissue. Er:YAG laser in defocused mode promoted slight morphological alterations and seems more suitable for enamel conditioning than focused irradiation. The application of phosphoric acid on lased-enamel surface, regardless of the irradiation distance, decreased the superficial irregularities.

Two types of congenital hydrocephalus induced in rats by X-irradiation in utero: electron microscopic study on the telencephalic wall

International Nuclear Information System (INIS)

Takeuchi, I.K.; Murakami, U.

1979-01-01

Stage-specific incidences of congenital hydrocephalus induced by X-irradiation of pregnant rats showed a bimodal distribution. At a dose level of 200 R, 100% hydrocephalic offspring were obtained by irradiation at embryonic days 11 and 14. When pregnant rats were subjected to 200 R X-irradiation at embryonic day 11, numerous ventricular cells of the telencephalic wall of the embryo became necrotic during the first 2 hours post-irradiation, but the paraventricular cell-to-cell interconnexions made up of zonulae adhaerentes were less affected. Mitosis took place in the surviving paraventricular surface cells throughout subsequent development. The full-term fetus exhibited little change in the cytoarchitectural arrangement of neural cells and neuropils, although it was only about half the thickness of the untreated control. After 200 R X-irradiation at embryonic day 14, most of the ventricular cells became necrotic within 6 hours. The paraventricular cell-to-cell interconnexions were completely destroyed, and never repaired in subsequent development. Mitosis took place either freely in cell clusters, or in rosettes which formed randomly in the telencephalic wall between 48 and 72 hours post-irradiation. The resulting telencephalic wall of the full-term fetus was also about half the thickness of the control. In the outer part of the tissue, the cortical plate made up of differentiating neuroblasts was hypoplastic, but the inner half was filled with numerous heterotopic masses of pleomorphic cells and bundles of primitive axons. The ependymal layer at the paraventricular surface was never formed. Whether the paraventricular zonulae adhaerentes were destroyed or not by X-irradiation was considered to be an important factor in the determination of the subsequent cytoarchitectural organization of the telencephalic wall. (author)

In vivo facial soft tissue thicknesses of adult Australians.

Science.gov (United States)

Stephan, Carl N; Preisler, Rory

2018-01-01

Facial soft tissue thicknesses (FSTT) set important quantitative guides in craniofacial identification, but so far Australian FSTTs have only been published for supine cadavers. This study aimed to use B-mode ultrasound to measure FSTTs in living Australians (N=63 participants; n 1 =52 [x¯=21 years, s=2 years]; and n 2 =11 [x¯=54years, s=13years]) using 14 craniometric landmarks with participants in both upright and supine positions. The multiple pre-existing Australian cadaver investigations (n=7 reporting FSTT means and 6 of these reporting raw datasets) enabled living and cadaveric samples drawn from the same parent population to be compared. By using a non-invasive and safe imaging method (no ionising radiation) repeated measurements could be taken in the in vivo participants to gauge measurement reliability (and compare to pre-existing reliability for cadaver measurements): mean r-TEM=12%; max r-TEM=25%. In terms of changes between upright and supine positions (as measured by B-mode ultrasound) only 2 of 14 measured landmarks had FSTT changes in excess of 1mm. Comparisons of the in vivo ultrasound data to pre-existing needle puncture studies demonstrated that mean B-mode ultrasound measurements were very similar to cadaver values. Contrary to popular thought, but in keeping with the findings of prior meta-analyses, cadaver FSTT data are good proxies to living subjects, at least as measured by ultrasound. To increase sample sizes and triangulate upon ground truth FSTT values, weighted grand means combining all Australian samples were calculated (n range=280-385) and compared to the multi-group 2018 adult T-Tables (max. n=10,333). Copyright © 2017 Elsevier B.V. All rights reserved.

External Volume Expansion in Irradiated Tissue: Effects on the Recipient Site.

Science.gov (United States)

Chin, Michael S; Lujan-Hernandez, Jorge; Babchenko, Oksana; Bannon, Elizabeth; Perry, Dylan J; Chappell, Ava G; Lo, Yuan-Chyuan; Fitzgerald, Thomas J; Lalikos, Janice F

2016-05-01

External volume expansion prepares recipient sites to improve outcomes of fat grafting. For patients receiving radiotherapy after mastectomy, results with external volume expansion vary, and the relationship between radiotherapy and expansion remains unexplored. Thus, the authors developed a new translational model to investigate the effects in chronic skin fibrosis after radiation exposure. Twenty-four SKH1-E mice received 50 Gy of β-radiation to each flank and were monitored until fibrosis developed (8 weeks). External volume expansion was then applied at -25 mmHg to one side for 6 hours for 5 days. The opposite side served as the control. Perfusion changes were assessed with hyperspectral imaging. Mice were euthanized at 5 (n = 12) and 15 days (n = 12) after the last expansion application. Tissue samples were analyzed with immunohistochemistry for CD31 and Ki67, Masson trichrome for skin thickness, and picrosirius red to analyze collagen composition. All animals developed skin fibrosis 8 weeks after radiotherapy and became hypoperfused based on hyperspectral imaging. Expansion induced edema on treated sides after stimulation. Perfusion was decreased by 13 percent on the expansion side (p External volume expansion temporarily reduces perfusion, likely because of transient ischemia or edema. Together with mechanotransduction, these effects encourage a proangiogenic and proliferative environment in fibrotic tissue after radiotherapy in the authors' mouse model. Further studies are needed to assess these changes in fat graft retention.

Neutron irradiation test of depleted CMOS pixel detector prototypes

International Nuclear Information System (INIS)

Mandić, I.; Cindro, V.; Gorišek, A.; Hiti, B.; Kramberger, G.; Mikuž, M.; Zavrtanik, M.; Hemperek, T.; Daas, M.; Hügging, F.; Krüger, H.; Pohl, D.-L.; Wermes, N.; Gonella, L.

2017-01-01

Charge collection properties of depleted CMOS pixel detector prototypes produced on p-type substrate of 2 kΩ cm initial resistivity (by LFoundry 150 nm process) were studied using Edge-TCT method before and after neutron irradiation. The test structures were produced for investigation of CMOS technology in tracking detectors for experiments at HL-LHC upgrade. Measurements were made with passive detector structures in which current pulses induced on charge collecting electrodes could be directly observed. Thickness of depleted layer was estimated and studied as function of neutron irradiation fluence. An increase of depletion thickness was observed after first two irradiation steps to 1 · 10 13 n/cm 2 and 5 · 10 13 n/cm 2 and attributed to initial acceptor removal. At higher fluences the depletion thickness at given voltage decreases with increasing fluence because of radiation induced defects contributing to the effective space charge concentration. The behaviour is consistent with that of high resistivity silicon used for standard particle detectors. The measured thickness of the depleted layer after irradiation with 1 · 10 15 n/cm 2 is more than 50 μm at 100 V bias. This is sufficient to guarantee satisfactory signal/noise performance on outer layers of pixel trackers in HL-LHC experiments.

Angular dependence of depth doses in a tissue slab irradiated with monoenergetic photons

International Nuclear Information System (INIS)

Till, E.; Zankl, M.; Drexler, G.

1995-12-01

This report presents dose equivalents from external photon irradiation, normalised to air kerma free in air, on the central axis of a cuboid slab of ICRU tissue for various depths, photon energies and angles of beam incidence. The data were calculated by a Monte Carlo method using an idealised planar parallel source of monoenergetic photons. The data presented here aim at facilitating the calibration of individual dosimeters; they provide also an estimate of the quantity 'personal dose equivalent' defined by the ICRU. A detailed evaluation of the dependence of the calculated conversion coefficients on depth in the slab, photon energy and angle of incidence is given. A comparison with published measured an calculated values of angular dependence factors is made. (orig.)

Production of Basella plants resistant to rust by irradiation of seeds and vegetative tissue

International Nuclear Information System (INIS)

Makambila, C.

1997-01-01

Basella is classified in the family Chenopodiaceae or Basellaceae. Also known as African spinach, this plant is consumed in Central Africa and several other African countries. There are two types of varieties grown in Congo: i. a local variety characterized by red leaves and stalks in which the principal way of propagation is from cuttings; ii. a group of varieties which have green or purple leaves and stalks. These varieties are called Basella alba and Basella rubra. These varieties have sexual reproduction. Among the two groups of varieties, the local variety is propagated vegetatively but is resistant to rust, while varieties with green leaves or with purple leaves (B. alba and B. rubra) that are propagated from seed are susceptible to rust. Since hybrid cannot be made by conventional crossing, the following procedures have been adopted to produce plants with disease tolerance: 1. production of resistant variants by irradiation of Basella alba seeds with Cesium 137; 2. production of resistant variants by irradiation of vegetative tissues obtained by culture of meristematic cells of B alba; and 3. obtaining resistant plants through somaclonal variation. 1 tab

Production of Basella plants resistant to rust by irradiation of seeds and vegetative tissue

Energy Technology Data Exchange (ETDEWEB)

Makambila, C [Laboratory of Phytopathology, Faculty of Sciences, Univ. of Brazzaville, Brazzaville (Congo)

1997-12-01

Basella is classified in the family Chenopodiaceae or Basellaceae. Also known as African spinach, this plant is consumed in Central Africa and several other African countries. There are two types of varieties grown in Congo: i. a local variety characterized by red leaves and stalks in which the principal way of propagation is from cuttings; ii. a group of varieties which have green or purple leaves and stalks. These varieties are called Basella alba and Basella rubra. These varieties have sexual reproduction. Among the two groups of varieties, the local variety is propagated vegetatively but is resistant to rust, while varieties with green leaves or with purple leaves (B. alba and B. rubra) that are propagated from seed are susceptible to rust. Since hybrid cannot be made by conventional crossing, the following procedures have been adopted to produce plants with disease tolerance: 1. production of resistant variants by irradiation of Basella alba seeds with Cesium 137; 2. production of resistant variants by irradiation of vegetative tissues obtained by culture of meristematic cells of B alba; and 3. obtaining resistant plants through somaclonal variation. 1 tab.

Effect of gamma irradiation on bitter pit of apple fruits (Malus Domestica Borkh)

International Nuclear Information System (INIS)

Al-Bachir, M.; Farah, S.

2000-12-01

Tow varieties of apple fruits Golden and Starking were irradiated with 0, 0.5, 1.0, 1.5 kGy and with 0, 1.0, 1.5 kGy respectively. Irradiated and unirradiated fruits were stored at 1 to 2 centigrade and relative humidity of 80 to 90%. Fruit quality (firmness, skin thickness and bitter pit) and juice characteristics (moisture, ash, carbohydrates, organic acids, Ph, and viscosity), were determined during storage periods (0, 3 and 6 months). The used doses of gamma irradiation significantly decreased the percentage and intensity of bitter pit. Irradiated fruits were softer immediately after irradiation and through storage periods, there were no differences in firmness between irradiated and unirradiated fruits. Gamma irradiation increased the thickness of skin in Golden fruits and decreased it in Starking. Juice production from both varieties immediately after irradiation was not affected by gamma irradiation. However the juice produced from irradiated fruits had higher organic acids (citric and malic acids), viscosity and Ph values than the control. (author)

Chronic irradiation of gonad tissue of the male rat

International Nuclear Information System (INIS)

Lemaire, G.; Maas, J.

1982-01-01

The effects of chronically irradiating rats' testes with daily gamma radiation doses of (1.4 - 8.6) x 10 -2 Gy for 71-140 days were studied. After about 30 days irradiation, the testes weights decrease and level off at about 75 days. Irradiation also caused the germ cells in the seminiferous tubules to disappear progressively, completely when the dose exceeded 6 x 10 -2 Gy/day and partially with the lower doses. At doses below 6 x 10 -2 Gy/day, there was also a delay in the spermatogenesis cycle with the spermatogonia and spermatocytes appearing to reach a new equilibrium, the level of which depended on the dose. (U.K.)

Immunological aspect of the electron-beam irradiation

Energy Technology Data Exchange (ETDEWEB)

Ikeda, K [Hyogo College of Medicine, Nishinomiya (Japan)

1978-05-01

In the present study, sciatic nerve tissues of the cat were emulsified with the complete Freund's adjuvant and injected into the foot-pads of the guinea pig. Frozen and frozen-irradiated feline sciatic nerve tissues were treated in the similar manner, and their encephalitogenicity was comparatively studied. Affected animals became skinny, weak in the hind limbs and sometimes solid their tails. Antigenic mixtures of the fresh peripheral nerves with adjuvant have sensitized 75% (15 out of 20) of guinea pigs, whereas none of the 41 animals manifested any sign of experimental allergic neuritis (EAN) after intradermal Frozen-preserved peripheral nerve-adjuvant mixtures gave rise to EAN in 29% (6 out of 21) of guinea pigs. The present results appear to show that the electron-beam irradiation might have modified the specific chemical structures of the myelin basic protein to completely suppress the encephalitogenicity of the peripheral nerve-tissues. High-voltage cathode irradiations would be capable of depressing the antigenicity of the transplantation immunology when the antigenic determinants have the chemical structures in common with the encephalitogenic antigens. Excessive amount of the irradiation used to result in severe tissue damages, therefore, an optimum dosis of electron-beams should be determined for each tissue destined for grafting. As the frozen peripheral nerve-adjuvant mixtures have been less encephalitogenic, freezing alone might well be considered partially to improve the acceptability of the grafts. Cryopreservation of the irradiated allografts would be worth further studying.

Immunological aspect of the electron-beam irradiation

International Nuclear Information System (INIS)

Ikeda, Kimiyuki

1978-01-01

In the present study, sciatic nerve tissues of the cat were emulsified with the complete Freund's adjuvant and injected into the foot-pads of the guinea pig. Frozen and frozen-irradiated feline sciatic nerve tissues were treated in the similar manner, and their encephalitogenicity was comparatively studied. Affected animals became skinny, weak in the hind limbs and sometimes solid their tails. Antigenic mixtures of the fresh peripheral nerves with adjuvant have sensitized 75% (15 out of 20) of guinea pigs, whereas none of the 41 animals manifested any sign of experimental allergic neuritis (EAN) after intradermal Frozen-preserved peripheral nerve-adjuvant mixtures gave rise to EAN in 29% (6 out of 21) of guinea pigs. The present results appear to show that the electron-beam irradiation might have modified the specific chemical structures of the myelin basic protein to completely suppress the encephalitogenicity of the peripheral nerve-tissues. High-voltage cathode irradiations would be capable of depressing the antigenicity of the transplantation immunology when the antigenic determinants have the chemical structures in common with the encephalitogenic antigens. Excessive amount of the irradiation used to result in severe tissue damages, therefore, an optimum dosis of electron-beams should be determined for each tissue destined for grafting. As the frozen peripheral nerve-adjuvant mixtures have been less encephalitogenic, freezing alone might well be considered partially to improve the acceptability of the grafts. Cryopreservation of the irradiated allografts would be worth further studying. (author)

Study of human mesenchymal stem cells plasticity into radiation injured tissues in a N.O.D./S.C.I.D. mouse model: therapeutic approach of the multiple organ dysfunction; Etude de la capacite plastique des Cellules Souches Mesenchymateuses humaines (CSM) apres irradiation du tissu receveur: approche therapeutique de l'atteinte multiorgane radio-induite

Energy Technology Data Exchange (ETDEWEB)

Francois, S

2006-01-15

The therapeutic potential of bone marrow-derived human mesenchymal stem cells (h.M.S.C.) has recently been brought into the spotlight of many fields of research. One possible application of the approach is the repair of injured tissues arising from side effects of radiation treatments and accidents. The first challenge in cell therapy is to assess the quality of the cell and the ability to retain their differentiation potential during the expansion process. Efficient delivery to the sites of intended action is also necessary. We addressed both questions using h.M.S.C. cultured and then infused to Non Obese Diabetes/Severe Combined Immunodeficiency (N.O.D./S.C.I.D.) mice submitted to total body irradiation. Further, we tested the impact of additional local irradiation superimposed to total body irradiation (T.B.I.), as a model of accidental irradiation. Our results showed that the h.M.S.C. used for transplant have been expanded without significant loss in their differentiation capacities. After transplantation into adult unconditioned mice, h.M.S.C. not only migrate in bone marrow but also into other tissues. Total body irradiation increased h.M.S.C. implantation in bone marrow and muscle and further led to engraftment in brain, heart, and liver. Local irradiation, in addition to T.B.I., increased both specific homing of injected cells to the injured tissues and to other tissues outside the local irradiation field. M.S.C. may participate to restoration of intestinal homeostasis 3 days post abdominal irradiation. This study suggests that using the potential of h.M.S.C. to home to various organs in response to tissue injuries could be a promising strategy to repair the radiation induced damages. (author)

Response functions for computing absorbed dose to skeletal tissues from photon irradiation-an update

Energy Technology Data Exchange (ETDEWEB)

Johnson, Perry B; Bahadori, Amir A [Nuclear and Radiological Engineering, University of Florida, Gainesville, FL 32611 (United States); Eckerman, Keith F [Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Lee, Choonsik [Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892 (United States); Bolch, Wesley E, E-mail: wbolch@ufl.edu [Nuclear and Radiological/Biomedical Engineering, University of Florida, Gainesville, FL 32611 (United States)

2011-04-21

A comprehensive set of photon fluence-to-dose response functions (DRFs) is presented for two radiosensitive skeletal tissues-active and total shallow marrow-within 15 and 32 bone sites, respectively, of the ICRP reference adult male. The functions were developed using fractional skeletal masses and associated electron-absorbed fractions as reported for the UF hybrid adult male phantom, which in turn is based upon micro-CT images of trabecular spongiosa taken from a 40 year male cadaver. The new DRFs expand upon both the original set of seven functions produced in 1985, and a 2007 update calculated under the assumption of secondary electron escape from spongiosa. In this study, it is assumed that photon irradiation of the skeleton will yield charged particle equilibrium across all spongiosa regions at energies exceeding 200 keV. Kerma coefficients for active marrow, inactive marrow, trabecular bone and spongiosa at higher energies are calculated using the DRF algorithm setting the electron-absorbed fraction for self-irradiation to unity. By comparing kerma coefficients and DRF functions, dose enhancement factors and mass energy-absorption coefficient (MEAC) ratios for active marrow to spongiosa were derived. These MEAC ratios compared well with those provided by the NIST Physical Reference Data Library (mean difference of 0.8%), and the dose enhancement factors for active marrow compared favorably with values calculated in the well-known study published by King and Spiers (1985 Br. J. Radiol. 58 345-56) (mean absolute difference of 1.9 percentage points). Additionally, dose enhancement factors for active marrow were shown to correlate well with the shallow marrow volume fraction (R{sup 2} = 0.91). Dose enhancement factors for the total shallow marrow were also calculated for 32 bone sites representing the first such derivation for this target tissue.

Electrical biopsy of irradiated intestinal tissue with a simple electrical impedance spectroscopy system for radiation enteropathy in rats—a pilot study

International Nuclear Information System (INIS)

Huang, Yu-Jie; Lu, Yi-Yu; Chen, Cheng-Yu; Cheng, Kuo-Sheng; Huang, Eng-Yen

2011-01-01

Electrical impedance is one of the most often used parameters for characterizing material properties, especially in biomedical applications. Electrical impedance spectroscopy (EIS), used for revealing both resistive and capacitive characteristics, is good for use in tissue characterization. In this study, a portable and simple EIS system based on a commercially available chip was used to assess rat intestinal tissues following irradiation. The EIS results were fitted to a resistor and capacitor electrical circuit model to solve the electrical properties of the tissue. The variation in the tissue's electrical characteristics was compared to the morphological and histological findings. From the experimental results, it was clear that the electrical properties, based on receiver operation curve analysis, demonstrated good detection performance relative to the histological changes. The electrical parameters of the tissues could be used to distinguish the tissue's status for investigation, which introduced a concept of 'electrical biopsy', and this 'electrical biopsy' approach may be used to complement histological examinations

Response functions for computing absorbed dose to skeletal tissues from neutron irradiation

Science.gov (United States)

Bahadori, Amir A.; Johnson, Perry; Jokisch, Derek W.; Eckerman, Keith F.; Bolch, Wesley E.

2011-11-01

Spongiosa in the adult human skeleton consists of three tissues—active marrow (AM), inactive marrow (IM) and trabecularized mineral bone (TB). AM is considered to be the target tissue for assessment of both long-term leukemia risk and acute marrow toxicity following radiation exposure. The total shallow marrow (TM50), defined as all tissues lying within the first 50 µm of the bone surfaces, is considered to be the radiation target tissue of relevance for radiogenic bone cancer induction. For irradiation by sources external to the body, kerma to homogeneous spongiosa has been used as a surrogate for absorbed dose to both of these tissues, as direct dose calculations are not possible using computational phantoms with homogenized spongiosa. Recent micro-CT imaging of a 40 year old male cadaver has allowed for the accurate modeling of the fine microscopic structure of spongiosa in many regions of the adult skeleton (Hough et al 2011 Phys. Med. Biol. 56 2309-46). This microstructure, along with associated masses and tissue compositions, was used to compute specific absorbed fraction (SAF) values for protons originating in axial and appendicular bone sites (Jokisch et al 2011 Phys. Med. Biol. 56 6857-72). These proton SAFs, bone masses, tissue compositions and proton production cross sections, were subsequently used to construct neutron dose-response functions (DRFs) for both AM and TM50 targets in each bone of the reference adult male. Kerma conditions were assumed for other resultant charged particles. For comparison, AM, TM50 and spongiosa kerma coefficients were also calculated. At low incident neutron energies, AM kerma coefficients for neutrons correlate well with values of the AM DRF, while total marrow (TM) kerma coefficients correlate well with values of the TM50 DRF. At high incident neutron energies, all kerma coefficients and DRFs tend to converge as charged-particle equilibrium is established across the bone site. In the range of 10 eV to 100 Me

Experimental studies on prevention of trichinosis by food irradiation (Co60)

International Nuclear Information System (INIS)

Shimazu, Kimitaka

1993-01-01

A systemic study was performed to elucidate the effects of 60 Co irradiation on maturation or fecundity of Trichinella spiralis by assessing from parasitological, morphological and immunological points of view. Pieces of muscle tissue of mice infected with T. spiralis were irradiated with 60 Co at doses of 50, 75, 100, 150 and 200 Gy. These irradiated tissue (Experimental group) and non-irradiated tissues (Control group) were fed to healthy mice. Half of the mice were sacrificed 6 days after the ingestion. The number of adult worms were counted and subjected to statistical analysis, which disclosed a good correlation between the dose of 60 Co irradiation and worm damage; the higher the dose the more damage parasites had, and no adults were recovered if the tissue had been irradiated with more than 150 Gy prior to infection. The same tendency was true for the histopathology of the intenstines of host mice; the higher the dose the less tissue damage. Circulating antigens of T. spiralis and antibodies against T. spiralis were detected in every serum examined by ELISA. The remaining mice were sacrificed 30 days after the ingestion. The numbers of muscle larvae were counted and subjected to statistical analysis, which disclosed a good correlation between th dose of 60 Co irradiation and worm damage, and no larvae were recovered if the tissue had been irradiated with more than 75Gy. Higher concentrations of circulating antigens of T. spiralis and antibodies against T. spiralis were detected in the serum samples taken with muscle larvae. Thus this study established that 60 Co irradiation of more than 150 Gy caused complete damage on maturation, and that irradiation of more than 75 Gy caused complete damage on the fecundity of T. spimalis. (author)

An algorithm to biological tissues evaluation in pediatric examinations

International Nuclear Information System (INIS)

Souza, R.T.F.; Miranda, J.R.A.; Alvarez, M.; Velo, A.F.; Pina, D.R.

2011-01-01

A prerequisite for the construction of phantoms is the quantification of the average thickness of biological tissues and the equivalence of these simulators in simulator material thicknesses. This study aim to develop an algorithm to classify and quantify tissues, based on normal distribution of CT numbers of anatomical structures found in the mean free path of the X-rays beam, using the examination histogram to carry out this evaluation. We have considered an algorithm for the determination of the equivalent biological tissues thickness from histograms. This algorithm classifies different biological tissues from tomographic exams in DICOM format and calculates the average thickness of these tissues. The founded results had revealed coherent with literature, presenting discrepancies of up to 21,6%, relative to bone tissue, analyzed for anthropomorphic phantom (RANDO). These results allow using this methodology in livings tissues, for the construction of thorax homogeneous phantoms, of just born and suckling patients, who will be used later in the optimization process of pediatrics radiographic images. (author)

The effect of irradiance on the carbon balance and tissue characteristics of five herbaceous species differing in shade-tolerance

Directory of Open Access Journals (Sweden)

Thijs Leendert Pons

2014-02-01

Full Text Available Plant photosynthesis scales positively with growth irradiance. The carbon balance, defined here as the daily whole-plant gross CO2 assimilation (A partitioned in C available for growth and C required for respiration (R, is thus irradiance dependent. Here we ask if R as a fraction of A is also irradiance dependent, whether there are systematic differences in C-balance between shade-tolerant and shade-intolerant species, and what the causes could be. Growth, gas exchange, chemical composition and leaf structure were analyzed for two shade-tolerant and three shade-intolerant herbaceous species that were hydroponically grown in a growth room at five irradiances from 20 µmol m-2 s-1 (1.2 mol m-2 day-1 to 500 µmol m-2 s-1 (30 mol m-2 day-1. Growth analysis showed little difference between species in unit leaf rate (dry mass increase per unit leaf area at low irradiance, but lower rates for the shade-tolerant species at high irradiance, mainly as a result of their lower light saturated rate of photosynthesis. This resulted in lower relative growth rates in these conditions. Daily whole-plant R scaled with A in a very tight manner, giving a remarkably constant R/A ratio of around 0.3 for all but the lowest irradiance. Although some shade-intolerant species showed tendencies towards a higher R/A and inefficiencies in terms of carbon and nitrogen investment in their leaves, no conclusive evidence was found for systematic differences in C-balance between the shade-tolerant and intolerant species at the lowest irradiance. Leaf tissue of the shade-tolerant species was characterized by high dry matter percentages, C-concentration and construction costs, which could be associated with a better defense in shade environments where leaf longevity matters. We conclude that shade-intolerant species have a competitive advantage at high irradiance due to superior potential growth rates, but that shade-tolerance is not necessarily associated with a superior C

Artificial semi-rigid tissue sensitized with natural pigments: Effect of photon radiations

Directory of Open Access Journals (Sweden)

Adnan Jaradat

2011-01-01

Full Text Available Background: A new approach for evaluating the optical penetration depth and testing its validity with Monte Carlo simulations and Kubelka-Munk theory is used for artificial semi-rigid tissue sensitized with natural pigments. Photodynamic therapy is a promising cancer treatment in which a photosensitizing drug concentrates in malignant cells and is activated by visible light at certain wavelength. Materials and Methods: Cheap artificial semi-rigid tissue incorporated with scattering and absorbing materials along with some other composites comparable to normal human tissue has been performed. The optical parameters as measured with different conditions and calculated with various techniques are investigated. Results: The probability of interaction of light with tissue is very high when exposed to light in presence of Cichorium pumilum and RBCs followed by photohemolysis or/and photodegradation. The optical penetration depth calculated by linear absorption coefficient ranges from 0.63 to 2.85 mm is found to be comparable to those calculated using Kubelka-Munk theory or Monte Carlo simulation (range from 0.78 to 2.42 mm. The ratio of absorption to the scattering is independent of thickness and decreases with increasing irradiation time. Moreover, the optical parameters as well as their ratios are in very good agreement in the two approaches of calculation. The values of absorption and scattering coefficients are independent of thickness. Furthermore, the average photon ranges in the samples containing no scattering and absorbing materials are about three times greater than those samples containing scattering materials. Conclusion: Our results suggest that light propagation with optical properties presented in this work could be applicable in diagnostic and therapeutic of the human biological tissue for photodynamic therapy.

Effect of ultraviolet irradiation on mast cell-deficient W/Wv mice

International Nuclear Information System (INIS)

Ikai, K.; Danno, K.; Horio, T.; Narumiya, S.

1985-01-01

The effect of UV irradiation on the skin was investigated in (WB-W/+) X (C57BL/6J-Wv/+)F1-W/Wv mice, which are genetically deficient in tissue mast cells. Their congenic littermates (+/+) and normal albino mice (ICR or BALB/c) were used as controls. Mice were irradiated with 500 mJ/cm2 of UVB and the increment of ear thickness was measured before and 6, 12, and 24 h after irradiation. Ear swelling in W/Wv mice at 12 and 24 h after irradiation was significantly smaller than that in +/+ and ICR mice. In contrast, the number of sunburn cells formed 24 h after UVB irradiation (200 or 500 mJ/cm2) was similar in W/Wv, +/+ and ICR mice. On the other hand, when mice were treated with 8-methoxy-psoralen (0.5%) plus UVA irradiation (4 J/cm2) (topical PUVA), ears of W/Wv and BALB/c mice, which were both white in color, were thickened similarly 72 h after treatment, but less swelling was observed in +/+ mice, which were black in skin color. The amount of prostaglandin D2 (PGD2) in ears, determined by radioimmunoassay specific for PGD2, was elevated 3-fold in +/+ and ICR mice at 3 h after irradiation with 500 mJ/cm2 of UVB in comparison with basal level without irradiation. However, such elevation was not observed in W/Wv mice. These results suggest that mast cells play an important role in UVB-induced inflammation, and PGs from mast cells are responsible at least in part for the development of this reaction. However, neither mast cells nor PGs contribute to the sunburn cell formation and ear swelling response by PUVA treatment

Improvement in the repair of defects in maxillofacial soft tissue in irradiated minipigs by a mixture of adipose-derived stem cells and platelet-rich fibrin.

Science.gov (United States)

Chen, Yuanzheng; Niu, Zhanguo; Xue, Yan; Yuan, Fukang; Fu, Yanjie; Bai, Nan

2014-10-01

To find out if adipose-derived stem cells (ASC) and platelet-rich fibrin (PRF), alone or combined, had any effect on the repair of maxillofacial soft tissue defects in irradiated minipigs, ASC were isolated, characterised, and expanded. Twenty female minipigs, the right parotid glands of which had been irradiated, were randomly divided into 4 groups of 5 each: those in the first group were injected with both ASC and PRF (combined group), the second group was injected with ASC alone (ASC group), the third group with PRF alone (PRF group), and the fourth group with phosphate buffer saline (PBS) (control group). Six months after the last injection, the size and depth of each defect were assessed, and subcutaneous tissues were harvested, stained with haematoxylin and eosin, and examined immunohistologically and for apoptosis. Expanded cells were successfully isolated and identified. Six months after injection the defects in the 3 treated groups were significantly smaller (p<0.001) and shallower (p<0.001) than those in the control group. Those in the combined group were the smallest and shallowest. Haematoxylin and eosin showed that the 3 treated groups contained more subcutaneous adipose tissue than the control group, and also had significantly greater vascular density (p<0.001) and fewer apoptotic cells (p<0.001). Both ASC and PRF facilitate the repair of defects in maxillofacial soft tissue in irradiated minipigs, and their combined use is more effective than their use as single agents. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Hassall's corpuscles in the guinea-pig thymus after a second 60Co local irradiation

International Nuclear Information System (INIS)

Kinoshita, Hideo

1974-01-01

The cervical regions of male guinea-pigs, weighing about 300 g, were irradiated locally with 60 Co 800 R, and the same dose of irradiation was repeated a second time in each guinea pig at a different interval. Thereafter, an irradiated animal was sacrificed every other day for 2 weeks. Thymuses were weighed and fixed in 10 percent formal saline. Tissues were blocked in paraffin and each block was cut into serial sections having a thickness of approximately 6 microns. These sections were stained with the haematoxylin-eosin (HE) and the aldehyde-fuchsin (AF) techniques. The size of Hassall's corpuscles was measured in the sections of HE and the AF (+) ratio of Hassall's corpuscles was calculated in sections of AF. The ratio (%) of the number of AF (+) corpuscles to the total number of corpuscles seen in the entire microscopical field was called ''AF (+) ratio''. The weight of the twice irradiated thymuses decreased regardless of the interval from the first irradiation. The tendency of Hassall's corpuscles to enlarge during the period of enlargement of the corpuscles after first irradiation was increased by the second irradiation. The enlarged pattern of Hassall's corpuscles after a single irradiation of 60 Co 800 R re-appeared when the animals were given a second irradiation on the 35th day. Concerning the AF (+) ratio of Hassall's corpuscles, the increasing pattern of AF (+) ratio such as after single irradiation of 60 Co 800 R re-appeared when the animals were given a second irradiation on the 35th day, but no effect was observed during the process of enlargement and disintegration of Hassall's corpuscles after the second irradiation. The enlargement of Hassall's corpuscles is attributed not only to the process of lympholysis, but also to various other factors such as the number and size of the corpuscles and the stage in their life cycle. (JPN)

Managing the Difficult Soft Tissue Envelope in Facial and Rhinoplasty Surgery.

Science.gov (United States)

Kosins, Aaron M; Obagi, Zein E

2017-02-01

The nasal soft tissue envelope affects the final rhinoplasty result, and can limit the expected improvement. Currently, no dependable and objective test exists to measure the thickness of the nasal skin and underlying soft tissue. This paper presents a simple, yet reliable method to determine the thickness of the soft tissue envelope. An algorithm is presented for treatment of the dermis and/or soft tissue apart from surgery of the underlying osseocartilaginous structures. Seventy-five patients presenting for primary rhinoplasty underwent visual and ultrasound assessment of their nasal soft tissue envelope. At preoperative evaluation, the Obagi "skin pinch test" was used to assess the thickness of the nasolabial fold and whether or not the skin was oily. Patients were classified based on the pinch thickness. At time of surgery prior to injection of local anesthesia, ultrasonic assessment was done at the nasolabial fold, keystone junction, supratip, and tip to measure the thickness of the nasal dermis and underlying soft tissue. Patients determined to have thin, normal, and thick skin by the "skin pinch test" were found to have a nasolabial fold dermal thickness with an average of 0.7 mm (0.4-1.2 mm), 1.1 mm (0.8-1.8 mm), and 1.4 mm (0.7-2.0 mm). Patients determined to have thin, normal, and thick skin were found to have a dermal thickness at the keystone junction with an average of 0.3 mm (0.2-0.4 mm), 0.5 mm (0.3-1.1 mm), and 0.9 mm (0.6-1.2 mm), respectively. This difference in thickness also translated to the supratip and tip areas measured. However, all areas were also affected by the oiliness of the skin. Soft tissue thickness (SMAS and muscle) underlying the dermis was variable. Patients of non-Caucasian background were more likely to have a thicker soft tissue layer. The "skin pinch test" is an easy and reliable way for the surgeon to evaluate the thickness of the nasal soft tissue envelope. The rhinoplasty surgeon can make decisions pre- and postoperatively

Systemic transplantation of human adipose tissue-derived mesenchymal stem cells for the regeneration of irradiation-induced salivary gland damage.

Directory of Open Access Journals (Sweden)

Jae-Yol Lim

Full Text Available OBJECTIVES: Cell-based therapy has been reported to repair or restore damaged salivary gland (SG tissue after irradiation. This study was aimed at determining whether systemic administration of human adipose-derived mesenchymal stem cells (hAdMSCs can ameliorate radiation-induced SG damage. METHODS: hAdMSCs (1 × 10(6 were administered through a tail vein of C3H mice immediately after local irradiation, and then this infusion was repeated once a week for 3 consecutive weeks. At 12 weeks after irradiation, functional evaluations were conducted by measuring salivary flow rates (SFRs and salivation lag times, and histopathologic and immunofluorescence histochemistry studies were performed to assay microstructural changes, apoptosis, and proliferation indices. The engraftment and in vivo differentiation of infused hAdMSCs were also investigated, and the transdifferentiation of hAdMSCs into amylase-producing SG epithelial cells (SGCs was observed in vitro using a co-culture system. RESULTS: The systemic administration of hAdMSCs exhibited improved SFRs at 12 weeks after irradiation. hAdMSC-transplanted SGs showed fewer damaged and atrophied acinar cells and higher mucin and amylase production levels than untreated irradiated SGs. Immunofluorescence TUNEL assays revealed fewer apoptotic cells in the hAdMSC group than in the untreated group. Infused hAdMSCs were detected in transplanted SGs at 4 weeks after irradiation and some cells were found to have differentiated into SGCs. In vitro, a low number of co-cultured hAdMSCs (13%-18% were observed to transdifferentiate into SGCs. CONCLUSION: The findings of this study indicate that hAdMSCs have the potential to protect against irradiation-induced cell loss and to transdifferentiate into SGCs, and suggest that hAdMSC administration should be viewed as a candidate therapy for the treatment of radiation-induced SG damage.

Contrast enhancement in the craniopharyngioma cyst wall caused by irradiation

Energy Technology Data Exchange (ETDEWEB)

Eldevik, O.P.; Gabrielsen, T.O.; Altinok, D. [Univ. of Michigan Medical Center, Ann Arbor, MI (United States). Div. of Neuroradiology

1998-03-01

Purpose: To report the occurrence, degree, frequency, and duration of contrast enhancement in the craniopharyngioma cyst wall as caused by irradiation. Material and Methods: Eight patients with cystic craniopharyngiomas had comparable CT or MR studies before and after either external irradiation of the cyst (n=5) or {sup 32}P instillation into the cyst (n=3). Results: A minimal to marked increase in cyst-wall enhancement was seen at 66-157 days after {sup 32}P instillation in 3/3 cases and at 112-495 days after external irradiation in 3/5 cases. The increased enhancement was always associated with a variable interim increase in the thickness of the enhanced cyst wall. Conclusion: CT or MR imaging after the irradiation of cystic craniopharyngiomas usually demonstrated an increase in thickness and enhancement in the cyst wall. Such changes may be due to the irradiation alone and do not necessarily represent infection or increased neoplastic activity. The timing is uncertain as to the earliest possible development of such changes and their maximum duration, but they were seen as early as 66 days post-irradiation and as late as 495 days post-irradiation. (orig.).

Contrast enhancement in the craniopharyngioma cyst wall caused by irradiation

International Nuclear Information System (INIS)

Eldevik, O.P.; Gabrielsen, T.O.; Altinok, D.

1998-01-01

Purpose: To report the occurrence, degree, frequency, and duration of contrast enhancement in the craniopharyngioma cyst wall as caused by irradiation. Material and Methods: Eight patients with cystic craniopharyngiomas had comparable CT or MR studies before and after either external irradiation of the cyst (n=5) or 32 P instillation into the cyst (n=3). Results: A minimal to marked increase in cyst-wall enhancement was seen at 66-157 days after 32 P instillation in 3/3 cases and at 112-495 days after external irradiation in 3/5 cases. The increased enhancement was always associated with a variable interim increase in the thickness of the enhanced cyst wall. Conclusion: CT or MR imaging after the irradiation of cystic craniopharyngiomas usually demonstrated an increase in thickness and enhancement in the cyst wall. Such changes may be due to the irradiation alone and do not necessarily represent infection or increased neoplastic activity. The timing is uncertain as to the earliest possible development of such changes and their maximum duration, but they were seen as early as 66 days post-irradiation and as late as 495 days post-irradiation. (orig.)

Repair of radiation injury by transplantation of hemopoietic tissue

International Nuclear Information System (INIS)

Smith, L.H.

1978-01-01

The following topics are discussed: endogenous repair of tissue by surviving cells; exogenous repair by transplantation of tissue from unirradiated donor; repair of hematopoietic tissue following sublethal exposure or exposure in the LD 1 to LD 100 range; early studies on regeneration of hematopoietic tissue in x-irradiated dogs by giving bone marrow; hypotheses as to how bone marrow injections result in regeneration of blood-forming tissue; effects of rat bone marrow transplants on survival of lethally irradiated mice; and effect of tissue transplants on dose-response curve

Upregulated epidermal growth factor receptor expression following near-infrared irradiation simulating solar radiation in a three-dimensional reconstructed human corneal epithelial tissue culture model.

Science.gov (United States)

Tanaka, Yohei; Nakayama, Jun

2016-01-01

Humans are increasingly exposed to near-infrared (NIR) radiation from both natural (eg, solar) and artificial (eg, electrical appliances) sources. Although the biological effects of sun and ultraviolet (UV) exposure have been extensively investigated, the biological effect of NIR radiation is still unclear. We previously reported that NIR as well as UV induces photoaging and standard UV-blocking materials, such as sunglasses, do not sufficiently block NIR. The objective of this study was to investigate changes in gene expression in three-dimensional reconstructed corneal epithelial tissue culture exposed to broad-spectrum NIR irradiation to simulate solar NIR radiation that reaches human tissues. DNA microarray and quantitative real-time polymerase chain reaction analysis were used to assess gene expression levels in a three-dimensional reconstructed corneal epithelial model composed of normal human corneal epithelial cells exposed to water-filtered broad-spectrum NIR irradiation with a contact cooling (20°C). The water-filter allowed 1,000-1,800 nm wavelengths and excluded 1,400-1,500 nm wavelengths. A DNA microarray with >62,000 different probes showed 25 and 150 genes that were up- or downregulated by at least fourfold and twofold, respectively, after NIR irradiation. In particular, epidermal growth factor receptor (EGFR) was upregulated by 19.4-fold relative to control cells. Quantitative real-time polymerase chain reaction analysis revealed that two variants of EGFR in human corneal epithelial tissue were also significantly upregulated after five rounds of 10 J/cm(2) irradiation (Psolar energy reaching the Earth is in the NIR region, which cannot be adequately blocked by eyewear and thus can induce eye damage with intensive or long-term exposure, protection from both UV and NIR radiation may prevent changes in gene expression and in turn eye damage.

The effect of irradiance on the carbon balance and tissue characteristics of five herbaceous species differing in shade-tolerance.

Science.gov (United States)

Pons, Thijs L; Poorter, Hendrik

2014-01-01

The carbon balance is defined here as the partitioning of daily whole-plant gross CO2 assimilation (A) in C available for growth and C required for respiration (R). A scales positively with growth irradiance and there is evidence for an irradiance dependence of R as well. Here we ask if R as a fraction of A is also irradiance dependent, whether there are systematic differences in C-balance between shade-tolerant and shade-intolerant species, and what the causes could be. Growth, gas exchange, chemical composition and leaf structure were analyzed for two shade-tolerant and three shade-intolerant herbaceous species that were hydroponically grown in a growth room at five irradiances from 20 μmol m(-2) s(-1) (1.2 mol m(-2) day(-1)) to 500 μmol m(-2) s(-1) (30 mol m(-2) day(-1)). Growth analysis showed little difference between species in unit leaf rate (dry mass increase per unit leaf area) at low irradiance, but lower rates for the shade-tolerant species at high irradiance, mainly as a result of their lower light-saturated rate of photosynthesis. This resulted in lower relative growth rates in these conditions. Daily whole-plant R scaled with A in a very tight manner, giving a remarkably constant R/A ratio of around 0.3 for all but the lowest irradiance. Although some shade-intolerant species showed tendencies toward a higher R/A and inefficiencies in terms of carbon and nitrogen investment in their leaves, no conclusive evidence was found for systematic differences in C-balance between the shade-tolerant and intolerant species at the lowest irradiance. Leaf tissue of the shade-tolerant species was characterized by high dry matter percentages, C-concentration and construction costs, which could be associated with a better defense in shade environments where leaf longevity matters. We conclude that shade-intolerant species have a competitive advantage at high irradiance due to superior potential growth rates, but that shade-tolerance is not necessarily associated

Patient absorbed radiation doses estimation related to irradiation anatomy

International Nuclear Information System (INIS)

Soares, Flavio Augusto Penna; Soares, Amanda Anastacio; Kahl, Gabrielly Gomes

2014-01-01

Developed a direct equation to estimate the absorbed dose to the patient in x-ray examinations, using electric, geometric parameters and filtering combined with data from irradiated anatomy. To determine the absorbed dose for each examination, the entrance skin dose (ESD) is adjusted to the thickness of the patient's specific anatomy. ESD is calculated from the estimated KERMA greatness in the air. Beer-Lambert equations derived from power data mass absorption coefficients obtained from the NIST / USA, were developed for each tissue: bone, muscle, fat and skin. Skin thickness was set at 2 mm and the bone was estimated in the central ray of the site, in the anteroposterior view. Because they are similar in density and attenuation coefficients, muscle and fat are treated as a single tissue. For evaluation of the full equations, we chose three different anatomies: chest, hand and thigh. Although complex in its shape, the equations simplify direct determination of absorbed dose from the characteristics of the equipment and patient. The input data is inserted at a single time and total absorbed dose (mGy) is calculated instantly. The average error, when compared with available data, is less than 5% in any combination of device data and exams. In calculating the dose for an exam and patient, the operator can choose the variables that will deposit less radiation to the patient through the prior analysis of each combination of variables, using the ALARA principle in routine diagnostic radiology sector

Surface cracking in proton-irradiated glass

International Nuclear Information System (INIS)

Jensen, T.; Lawn, B.R.; Dalglish, R.L.; Kelly, J.C.

1976-01-01

Some observations are reported of the surface fracture behaviour of soda-lime glass slabs (6mm thick Pilkington float glass) irradiated with 480 kV protons. A simple indentation microfracture technique provided a convenient means of probing the irradiated surface regions. Basically, the technique involves loading a standard Vickers diamond pyramid indenter onto the area of interest such that a well-developed deformation/fracture pattern is generated. (author)

Non-thermal near-infrared exposure photobiomodulates cellular responses to ionizing radiation in human full thickness skin models.

Science.gov (United States)

König, Anke; Zöller, Nadja; Kippenberger, Stefan; Bernd, August; Kaufmann, Roland; Layer, Paul G; Heselich, Anja

2018-01-01

Ionizing and near-infrared radiation are both part of the therapeutic spectrum in cancer treatment. During cancer therapy ionizing radiation is typically used for non-invasive reduction of malignant tissue, while near-infrared photobiomodulation is utilized in palliative medical approaches, e.g. for pain reduction or impairment of wound healing. Furthermore, near-infrared is part of the solar wavelength spectrum. A combined exposure of these two irradiation qualities - either intentionally during medical treatment or unintentionally due to solar exposure - is therefore presumable for cancer patients. Several studies in different model organisms and cell cultures show a strong impact of near-infrared pretreatment on ionizing radiation-induced stress response. To investigate the risks of non-thermal near-infrared (NIR) pretreatment in patients, a human in vitro full thickness skin models (FTSM) was evaluated for radiation research. FTSM were pretreated with therapy-relevant doses of NIR followed by X-radiation, and then examined for DNA-double-strand break (DSB) repair, cell proliferation and apoptosis. Double-treated FTSM revealed a clear influence of NIR on X-radiation-induced stress responses in cells in their typical tissue environment. Furthermore, over a 24h time period, double-treated FTSM presented a significant persistence of DSBs, as compared to samples exclusively irradiated by X-rays. In addition, NIR pretreatment inhibited apoptosis induction of integrated fibroblasts, and counteracted the radiation-induced proliferation inhibition of basal keratinocytes. Our work suggests that cancer patients treated with X-rays should be prevented from uncontrolled NIR irradiation. On the other hand, controlled double-treatment could provide an alternative therapy approach, exposing the patient to less radiation. Copyright © 2017. Published by Elsevier B.V.

Dosimetric evaluation in heterogeneous tissue of anterior electron beam irradiation for treatment of retinoblastoma

International Nuclear Information System (INIS)

Kirsner, S.M.; Hogstrom, K.R.; Kurup, R.G.; Moyers, M.F.

1987-01-01

A dosimetric study of anterior electron beam irradiation for treatment of retinoblastoma was performed to evaluate the influence of tissue heterogeneities on the dose distribution within the eye and the accuracy of the dose calculated by a pencil beam algorithm. Film measurements were made in a variety of polystyrene phantoms and in a removable polystyrene eye incorporated into a tissue substitute phantom constructed from a human skull. Measurements in polystyrene phantoms were used to demonstrate the algorithm's ability to predict the effect of a lens block placed in the beam, as well as the eye's irregular surface shape. The eye phantom was used to measure dose distributions within the eye in both the sagittal and transverse planes in order to test the algorithm's ability to predict the dose distribution when bony heterogeneities are present. Results show (1) that previous treatment planning conclusions based on flat, uniform phantoms for central-axis depth dose are adequate; (2) that a three-dimensional heterogeneity correction is required for accurate dose calculations; and (3) that if only a two-dimensional heterogeneity correction is used in calculating the dose, it is more accurate for the sagittal than the transverse plane

Facile synthesis of CdS@TiO2 core–shell nanorods with controllable shell thickness and enhanced photocatalytic activity under visible light irradiation

International Nuclear Information System (INIS)

Dong, Wenhao; Pan, Feng; Xu, Leilei; Zheng, Minrui; Sow, Chorng Haur; Wu, Kai; Xu, Guo Qin

2015-01-01

Graphical abstract: - Highlights: • CdS nanorods were coated with amorphous TiO 2 shells under a mild condition. • The TiO 2 shell thickness can be controlled from 3.5 to 40 nm. • CdS@TiO 2 nanorods exhibit enhanced photocatalytic activities under visible light. • Efficient charge carriers separation leads to the improved photocatalytic activity. - Abstract: Amorphous TiO 2 layers with a controllable thickness from 3.5 to 40 nm were coated on the one-dimensional CdS nanorods surface under mild conditions. Compared to the bare CdS nanorods, the as-prepared CdS@TiO 2 nanorods exhibit enhanced photocatalytic activities for phenol photodecomposition under visible light irradiation. The improved photoactivity is ascribed to the efficient separation of photogenerated electron and hole charge carriers between CdS cores and TiO 2 shells. This study promises a simple approach to fabricating CdS@TiO 2 core–shell structure nanocomposites, and can be applied for other semiconductor cores with TiO 2 shells

Effect of red and infrared low-level laser therapy in endodontic sealer on subcutaneous tissue

Science.gov (United States)

Sivieri-Araujo, G.; Berbert, F. L. C. V.; Ramalho, L. T. O.; Rastelli, A. N. S.; Crisci, F. S.; Bonetti-Filho, I.; Tanomaru-Filho, M.

2011-12-01

This study evaluated the reactions of connective tissue after the implant of one endodontic sealer (Endofill) that was irradiated with low-level laser therapy (LLLT). Sixty mice were distributed into three Groups ( n = 20): GI—the tubes filled with Endofill were implanted in the animals and were not irradiated with LLLT; GII—the tubes containing Endofill were implanted in the animals and then irradiated with red LLLT (InGaAlP, λ = 685 nm, P = 35 mW, t = 58 s, D = 72 J/cm2, E = 2 J, Ø = 0.60 mm, continuous mode) and GIII—the tubes with Endofill were implanted and irradiated with infrared LLLT (AsGaAl, λ = 830 nm, P = 50 mW, t = 40 s, D = 70 J/cm2, E = 2 J, Ø = 0.60 mm, continuous wave) both are semiconductor diode laser device. The animals were killed after 7 and 30 days. Series sections of 6 μm thickness were obtained and stained with Hematoxylin-Eosin and Masson Trichrome. The data of the histopathological evaluation were submitted to Kruskal-Wallis and Dunn's tests at 5% significance level. At the 7th day: GI showed the presence of inflammation; GII and GIII reduced inflammation. At 30th day: GI showed low inflammation; GII and GII the absence of inflammation. It was possible show that LLLT reduced the irritating effect promoted by the Endofill, in the period of 7 days ( p > 0.05). The tissue repair occurred in 30 days, regardless of the use of LLLT.

Nomogram to Predict Graft Thickness in Descemet Stripping Automated Endothelial Keratoplasty: An Eye Bank Study.

Science.gov (United States)

Bae, Steven S; Menninga, Isaac; Hoshino, Richard; Humphreys, Christine; Chan, Clara C

2018-06-01

The purpose of this study was to develop a nomogram to predict postcut thickness of corneal grafts prepared at an eye bank for Descemet stripping automated endothelial keratoplasty (DSAEK). Retrospective chart review was performed of DSAEK graft preparations by 3 experienced technicians from April 2012 to May 2017 at the Eye Bank of Canada-Ontario Division. Variables collected included the following: donor demographics, death-to-preservation time, death-to-processing time, precut tissue thickness, postcut tissue thickness, microkeratome head size, endothelial cell count, cut technician, and rate of perforation. Linear regression models were generated for each microkeratome head size (300 and 350 μm). A total of 780 grafts were processed during the study period. Twelve preparation attempts resulted in perforation (1.5%) and were excluded. Mean precut tissue thickness was 510 ± 49 μm (range: 363-670 μm). Mean postcut tissue thickness was 114 ± 22 μm (range: 57-193 μm). Seventy-nine percent (608/768) of grafts were ≤130 μm. The linear regression models included precut thickness and donor age, which were able to predict the thickness to within 25 μm 80% of the time. We report a nomogram to predict thickness of DSAEK corneal grafts prepared in an eye bank setting, which was accurate to within 25 μm 80% of the time. Other eye banks could consider performing similar analyses.

Irradiation effects in superconductor oxides. Effets d'irradiation dans les oxydes supraconducteurs

Energy Technology Data Exchange (ETDEWEB)

Rullier-Albenque, F; Konczykowski, M [CEA-Ecole Polytechnique, 91 - Palaiseau (France). Lab. d' Etudes des Solides Irradies

1993-01-01

Several effects of irradiation on the 92 K - oxide superconductor YBa[sub 2]Cu[sub 3]O[sub 7] are reported. Whatever irradiation type, the critical temperature T[sub c] is found to decrease and the resistivity to increase. At sufficiently high damage levels, YBa[sub 2]Cu[sub 3]O[sub 7] is no longer superconducting and even displays a semiconducting-like behaviour. The alterations of superconducting properties are clearly related to oxygen defects - in the CuO[sub 2] planes or CuO chains... but we have shown experimentally that copper defects are also important. Magnetic properties of YBa[sub 2]Cu[sub 3]O[sub 7] in mixed state are also very sensitive to irradiation. By pinning the flux lines, irradiation defects can considerably increase the critical current density j[sub c]. At present, irradiations by highly energetic heavy ions (6 GeV Pb for instance), which produce cylindrical tubes of amorphous material (latent tracks) throughout the whole thickness of the samples, are probably the most efficient way to enhance j[sub c]. (Author). 18 refs., 7 figs.

Proton irradiation effects on organic polymers

International Nuclear Information System (INIS)

Seguchi, T.; Sasuga, T.; Kawakami, W.; Hagiwara, M.; Kohno, I.; Kamitsubo, H.

1987-01-01

Organic polymer films(100 μm thickness) of polyethylene, polypropylene, polyethyleneterephtalate, and polyethersulfone were irradiated by protons of 8 MeV using a cyclotron, and their radiation effects were investigated by the changes of mechanical properties. In order to irradiate protons uniformly over wide area of polymer films, specimens were scanned during proton irradiation using a special apparatus. The absorbed dose was measured by CTA and RCD film dosimeters, and can be determined that 1 μC/cm 2 of 8 MeV proton fluence is equivalent to 54 kGy. For polyethylene and polypropylene, there was no significant difference between proton and electron irradiation for same doses. However, for polyethersulfone the decay of mechanical property was observed to be less than that of irradiation by electron. (author)

Radiation-induced soft-tissue and bone sarcoma

International Nuclear Information System (INIS)

Kim, J.H.; Chu, F.C.; Woodard, H.Q.; Melamed, R.; Huvos, A.; Cantin, J.

1978-01-01

From the records of Memorial Hospital of the past 50 years, 47 cases with an established diagnosis of radiation-induced sarcoma were identified and divided into two groups: the first included 20 cases of soft-tissue sarcoma arising from irradiated tissues, and the second comprised 27 cases of bone sarcoma arising from normal bones in the irradiated field. Medians for the latent periods from irradiation to diagnosis of bone and soft-tissue sarcoma were 11 and 12, years, respectively. In bone sarcomas, the latent period was longer after larger radiation doses and children appeared to be more susceptible to cancer induction than adults. Criteria for establishing the diagnosis of radiation-induced sarcoma and the magnitude of the risk of bone sarcoma are discussed

Interdiffusion and grain-boundary migration in Au-Cu bilayers during ion-irradiation

International Nuclear Information System (INIS)

Alexander, D.E.; Rehn, L.E.; Baldo, P.M.

1991-11-01

Ion irradiation and annealing experiments have been conducted on Au/Cu bilayer films to evaluate the effect of irradiation on diffusion-induced grain boundary migration (DIGM). The Au films were prepared with a large-grained microstructure with grain boundaries perpendicular to the film surface and extending through the film thickness. Irradiations were conducted with 1.5 MeV Kr at 228 degree C. Rutherford backscattering spectrometry of the samples revealed that interdiffusion was substantially enhanced in the irradiated area relative to the unirradiated area. Both irradiated and annealed-only areas were characterized by a nearly uniform composition of 14 at.% and 7 at.% Cu respectively through the entire thickness of the underlying Au film. Small probe X-ray energy dispersive spectroscopy showed significant lateral compositional homogeneities in both irradiated and annealed areas. These two results are consistent with previous observations of DIGM in the Au/Cu system, suggesting that this previously unexamined mechanism contributes to ion beam mixing

Gamma irradiation-induced variation in carrots (Daucus carota L.)

International Nuclear Information System (INIS)

Al-Safadi, B.; Simon, P.W.

1996-01-01

Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue cultures, were exposed to low doses of gamma irradiation. Higher doses reduced M1 plant size by 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M2 families. Less variation was observed in total carotene content and none was seen in sugar type (reducing vs. non reducing sugars). Induced variation in root color and root shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M2 somaclonal variation. Average root weight of M2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment

Gamma irradiation induced variation in carrots (Daucus Carota L.)

International Nuclear Information System (INIS)

Al-Safady, B.; Simon, P.W.

1999-01-01

Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M 1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue culture, were exposed to low doses of gamma irradiation. Higher doses reduced M 1 plant size by > 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M 1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M 2 families. Less variation was observed in total carotene content and none was seen in sugar type [reducing vs. non reducing sugars]. Induced variation in root color and rot shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M 2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M 2 somaclonal variation. Average root weight of M 2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment (Author)

Optimization of phantom backscatter thickness and lateral scatter volume for radiographic film dosimetry

International Nuclear Information System (INIS)

Srivastava, R.P.; De Wagter, C.

2012-01-01

The aim of this study is to determine the optimal backscatter thickness and lateral phantom dimension beyond the irradiated volume for the dosimetric verification with radiographic film when applying large field sizes. Polystyrene and Virtual Water™ phantoms were used to study the influence of the phantom backscatter thickness. EDR2 and XV films were used in 6 and 18 MV photon beams. The results show 11.4% and 6.4% over-response of the XV2 film when compared to the ion chamber for 6 MV 30×30 and 10×10 cm 2 field sizes, respectively, when the phantom backscatter thickness is 5 cm. For the same setup, measurements with EDR2 films indicate 8.5% and 1.7% over-response. The XV2 film response in the polystyrene phantom is about 2.0% higher than in the Virtual Water™ phantom for the 6 MV beam and 20 cm backscatter thickness. Similar results were obtained for EDR2 film. In the lateral scatter study, film response was nearly constant within 5 cm of lateral thickness and it increases when lateral thickness increases due to more multiple scatter of low energy photons. The backscatter thickness of the phantom should be kept below 7 cm for the accuracy of the film dosimetry. The lateral extension of the phantom should not be more than 5 cm from the field boundary in case of large irradiated volumes.

Production of irradiated bone derivatives for odontology and traumatology

International Nuclear Information System (INIS)

Martin, Hugo R.; Murature, D.A.

2004-01-01

In 2003, the National Atomic Energy Commission (CNEA), the Industrial Human Tissue Processing Plant of the Cordoba University and the Cordoba Science Agency analyzed the joint installation and operation of a Gamma Radiosterilization Module for the production of sterile human bone tissues as allografts for odontology and traumatology. The irradiation procedures were developed at the CNEA's Ezeiza Atomic Center. The irradiated bone tissues are being used in odontology with an excellent clinical behaviour. (author)

SU-E-T-501: Normal Tissue Toxicities of Pulsed Low Dose Rate Radiotherapy and Conventional Radiotherapy: An in Vivo Total Body Irradiation Study

Energy Technology Data Exchange (ETDEWEB)

Cvetkovic, D; Zhang, P; Wang, B; Chen, L; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States)

2014-06-01

Purpose: Pulsed low dose rate radiotherapy (PLDR) is a re-irradiation technique for therapy of recurrent cancers. We have previously shown a significant difference in the weight and survival time between the mice treated with conventional radiotherapy (CRT) and PLDR using total body irradiation (TBI). The purpose of this study was to investigate the in vivo effects of PLDR on normal mouse tissues.Materials and Methods: Twenty two male BALB/c nude mice, 4 months of age, were randomly assigned into a PLDR group (n=10), a CRT group (n=10), and a non-irradiated control group (n=2). The Siemens Artiste accelerator with 6 MV photon beams was used. The mice received a total of 18Gy in 3 fractions with a 20day interval. The CRT group received the 6Gy dose continuously at a dose rate of 300 MU/min. The PLDR group was irradiated with 0.2Gyx20 pulses with a 3min interval between the pulses. The mice were weighed thrice weekly and sacrificed 2 weeks after the last treatment. Brain, heart, lung, liver, spleen, gastrointestinal, urinary and reproductive organs, and sternal bone marrow were removed, formalin-fixed, paraffin-embedded and stained with H and E. Morphological changes were observed under a microscope. Results: Histopathological examination revealed atrophy in several irradiated organs. The degree of atrophy was mild to moderate in the PLDR group, but severe in the CRT group. The most pronounced morphological abnormalities were in the immune and hematopoietic systems, namely spleen and bone marrow. Brain hemorrhage was seen in the CRT group, but not in the PLDR group. Conclusions: Our results showed that PLDR induced less toxicity in the normal mouse tissues than conventional radiotherapy for the same dose and regimen. Considering that PLDR produces equivalent tumor control as conventional radiotherapy, it would be a good modality for treatment of recurrent cancers.

Hassall's corpuscles in the guinea-pig thymus after a second /sup 60/Co local irradiation

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, H [Nara Medical Univ., Kashihara (Japan)

1974-12-01

The cervical regions of male guinea-pigs, weighing about 300 g, were irradiated locally with /sup 60/Co 800 R, and the same dose of irradiation was repeated a second time in each guinea pig at a different interval. Thereafter, an irradiated animal was sacrificed every other day for 2 weeks. Thymuses were weighed and fixed in 10 percent formal saline. Tissues were blocked in paraffin and each block was cut into serial sections having a thickness of approximately 6 microns. These sections were stained with the haematoxylin-eosin (HE) and the aldehyde-fuchsin (AF) techniques. The size of Hassall's corpuscles was measured in the sections of HE and the AF (+) ratio of Hassall's corpuscles was calculated in sections of AF. The ratio (%) of the number of AF (+) corpuscles to the total number of corpuscles seen in the entire microscopical field was called ''AF (+) ratio''. The weight of the twice irradiated thymuses decreased regardless of the interval from the first irradiation. The tendency of Hassall's corpuscles to enlarge during the period of enlargement of the corpuscles after first irradiation was increased by the second irradiation. The enlarged pattern of Hassall's corpuscles after a single irradiation of /sup 60/Co 800 R re-appeared when the animals were given a second irradiation on the 35th day. Concerning the AF (+) ratio of Hassall's corpuscles, the increasing pattern of AF (+) ratio such as after single irradiation of /sup 60/Co 800 R re-appeared when the animals were given a second irradiation on the 35th day, but no effect was observed during the process of enlargement and disintegration of Hassall's corpuscles after the second irradiation. The enlargement of Hassall's corpuscles is attributed not only to the process of lympholysis, but also to various other factors such as the number and size of the corpuscles and the stage in their life cycle.

PIE Report on the KOMO-3 Irradiation Test Fuels

International Nuclear Information System (INIS)

Park, Jong Man; Ryu, H. J.; Yang, J. H.

2009-04-01

In the KOMO-3, in-reactor irradiation test had been performed for 12 kinds of dispersed U-Mo fuel rods, a multi wire fuel rod and a tube fuel rod. In this report we described the PIE results on the KOMO-3 irradiation test fuels. The interaction layer thickness between fuel particle and matrix could be reduced by using a large size U-Mo fuel particle or introducing Al-Si matrix or adding the third element in the U-Mo particle. Monolithic fuel rod of multi-wire or tube fuel was also effective in reducing the interaction layer thickness

Combined treatment of 8 MHz radiofrequency hyperthermia and irradiation for advanced urological malignancies

International Nuclear Information System (INIS)

Nakajima, Kazuyoshi; Hisazumi, Haruo; Yamamoto, Hajime; Naito, Katsusuke; Misaki, Toshimitsu; Kobashi, Kazunori; Yokoyama, Osamu; Saito, Yasuo

1986-01-01

A combined therapy of irradiation and 8 MHz radiofrequency hyperthermia using Thermotron-RF Model 8 was carried out in a total of 26 patients with urological malignancies; 9 renal cancers, 1 renal capsular tumor, multiple liver metastatic lesions of renal cancer, a postoperative mediastinal metastasis of renal cancer, 2 ureteral cancers associated with bladder cancers, 4 bladder cancers, 4 prostatic cancers, a postoperative local recurrent tumor of an adult type Wilms' tumor, and multiple skin metastatic lesions of a penile cancer. Previous therapies were unsuccessful, or surgical interventions were not indicated because of poor general conditions. They were irradiated with daily 1.8 to 2.0 Gy, 5 times a week, or daily 2.0 to 4.0 Gy twice a week. Hyperthermia was induced twice a week within one hour after each irradiation, in total 10 times for 5 weeks. Intratumoral temperature was kept between 42.0 to 44.0 deg C. Clinical efficacy was evaluated by CT, ultrasound and biochemical data. Partial tumor regression, defined as the regression of 50 % or more, was obtained in one of the 9 renal cancers, in the mediastinal metastasis of renal cancer, 2 of the 4 prostatic cancers, one of the 4 bladder cancers and the 2 ureteral cancers, CR was obtained in the 2 associated bladder cancers. As side effects, a mild skin burns and anorexia were observed in approximately 50 % of the cases. Subcutaneous fat tissue indurations occurred in 6 of the 30 patients, who had 15 mm or more thickness of subdermal fat tissues, after treatment. (author)

Comprehensive irradiation of head and neck cancer using conformal multisegmental fields: assessment of target coverage and noninvolved tissue sparing

International Nuclear Information System (INIS)

Eisbruch, Avraham; Marsh, Lon H.; Martel, Mary K.; Ship, Jonathan A.; Haken, Randall ten; Pu, Anthony T.; Fraass, Benedick A.; Lichter, Allen S.

1998-01-01

Purpose: Conformal treatment using static multisegmental intensity modulation was developed for patients requiring comprehensive irradiation for head and neck cancer. The major aim is sparing major salivary gland function while adequately treating the targets. To assess the adequacy of the conformal plans regarding target coverage and dose homogeneity, they were compared with standard irradiation plans. Methods and Materials: Fifteen patients with stage III/IV head and neck cancer requiring comprehensive, bilateral neck irradiation participated in this study. CT-based treatment plans included five to six nonopposed fields, each having two to four in-field segments. Fields and segments were devised using beam's eye views of the planning target volumes (PTVs), noninvolved organs, and isodose surfaces, to achieve homogeneous dose distribution that encompassed the targets and spared major salivary gland tissue. For comparison, standard three-field radiation plans were devised retrospectively for each patient, with the same CT-derived targets used for the clinical (conformal) plans. Saliva flow rates from each major salivary gland were measured before and periodically after treatment. Results: On average, the minimal dose to the primary PTVs in the conformal plans [95.2% of the prescribed dose, standard deviation (SD) 4%] was higher than in the standard plans (91%, SD 7%; p = 0.02), and target volumes receiving <95% or <90% of the prescribed dose were smaller in the conformal plans (p = 0.004 and 0.02, respectively). Similar advantages of the conformal plans compared to standard plans were found in ipsilateral jugular nodes PTV coverage. The reason for underdosing in the standard treatment plans was primarily failure of electron beams to fully encompass targets. No significant differences were found in contralateral jugular or posterior neck nodes coverage. The minimal dose to the retropharyngeal nodes was higher in the standard plans. However, all conformal plans

Experimental Platform for Ultra-high Dose Rate FLASH Irradiation of Small Animals Using a Clinical Linear Accelerator

Energy Technology Data Exchange (ETDEWEB)

Schüler, Emil; Trovati, Stefania; King, Gregory; Lartey, Frederick; Rafat, Marjan; Villegas, Manuel; Praxel, A. Joe [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Loo, Billy W., E-mail: BWLoo@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States); Maxim, Peter G., E-mail: PMaxim@stanford.edu [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California (United States); Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California (United States)

2017-01-01

Purpose: A key factor limiting the effectiveness of radiation therapy is normal tissue toxicity, and recent preclinical data have shown that ultra-high dose rate irradiation (>50 Gy/s, “FLASH”) potentially mitigates this effect. However, research in this field has been strongly limited by the availability of FLASH irradiators suitable for small animal experiments. We present a simple methodologic approach for FLASH electron small animal irradiation with a clinically available linear accelerator (LINAC). Methods and Materials: We investigated the FLASH irradiation potential of a Varian Clinac 21EX in both clinical mode and after tuning of the LINAC. We performed detailed FLUKA Monte Carlo and experimental dosimetric characterization at multiple experimental locations within the LINAC head. Results: Average dose rates of ≤74 Gy/s were achieved in clinical mode, and the dose rate after tuning exceeded 900 Gy/s. We obtained 220 Gy/s at 1-cm depth for a >4-cm field size with 90% homogeneity throughout a 2-cm-thick volume. Conclusions: We present an approach for using a clinical LINAC for FLASH irradiation. We obtained dose rates exceeding 200 Gy/s after simple tuning of the LINAC, with excellent dosimetric properties for small animal experiments. This will allow for increased availability of FLASH irradiation to the general research community.

Experimental Platform for Ultra-high Dose Rate FLASH Irradiation of Small Animals Using a Clinical Linear Accelerator.

Science.gov (United States)

Schüler, Emil; Trovati, Stefania; King, Gregory; Lartey, Frederick; Rafat, Marjan; Villegas, Manuel; Praxel, A Joe; Loo, Billy W; Maxim, Peter G

2017-01-01

A key factor limiting the effectiveness of radiation therapy is normal tissue toxicity, and recent preclinical data have shown that ultra-high dose rate irradiation (>50 Gy/s, "FLASH") potentially mitigates this effect. However, research in this field has been strongly limited by the availability of FLASH irradiators suitable for small animal experiments. We present a simple methodologic approach for FLASH electron small animal irradiation with a clinically available linear accelerator (LINAC). We investigated the FLASH irradiation potential of a Varian Clinac 21EX in both clinical mode and after tuning of the LINAC. We performed detailed FLUKA Monte Carlo and experimental dosimetric characterization at multiple experimental locations within the LINAC head. Average dose rates of ≤74 Gy/s were achieved in clinical mode, and the dose rate after tuning exceeded 900 Gy/s. We obtained 220 Gy/s at 1-cm depth for a >4-cm field size with 90% homogeneity throughout a 2-cm-thick volume. We present an approach for using a clinical LINAC for FLASH irradiation. We obtained dose rates exceeding 200 Gy/s after simple tuning of the LINAC, with excellent dosimetric properties for small animal experiments. This will allow for increased availability of FLASH irradiation to the general research community. Copyright © 2016 Elsevier Inc. All rights reserved.

Transplantation of an LGR6+ Epithelial Stem Cell-Enriched Scaffold for Repair of Full-Thickness Soft-Tissue Defects: The In Vitro Development of Polarized Hair-Bearing Skin.

Science.gov (United States)

Lough, Denver M; Wetter, Nathan; Madsen, Christopher; Reichensperger, Joel; Cosenza, Nicole; Cox, Lisa; Harrison, Carrie; Neumeister, Michael W

2016-02-01

Recent literature has shown that full-thickness wounds, devoid of the stem cell niche, can subsequently be reconstructed with functional skin elements following migration of the LGR6 epithelial stem cell into the wound bed. In this study, the authors use a variety of LGR6 epithelial stem cell-seeded scaffolds to determine therapeutic utility and regenerative potential in the immediate reconstruction of full-thickness wounds. Isolated LGR6 epithelial stem cells were seeded onto a spectrum of acellular matrices and monitored in both in vitro and in vivo settings to determine their relative capacity to regenerate tissues and heal wounds. Wound beds containing LGR6 stem cell-seeded scaffolds showed significantly augmented rates of healing, epithelialization, and hair growth compared with controls. Gene and proteomic expression studies indicate that LGR6 stem cell-seeded constructs up-regulate WNT, epidermal growth factor, and angiogenesis pathways. Finally, the addition of stromal vascular fraction to LGR6 stem cell-seeded constructs induces polarized tissue formation, nascent hair growth, and angiogenesis within wounds. LGR6 stem cells are able to undergo proliferation, differentiation, and migration following seeding onto a variety of collagen-based scaffolding. In addition, deployment of these constructs induces epithelialization, hair growth, and angiogenesis within wound beds. The addition of stromal vascular fraction to LGR6 stem cell-containing scaffolds initiated an early form of tissue polarization, providing for the first time a clinically applicable stem cell-based construct that is capable of the repair of full-thickness wounds and hair regeneration. Therapeutic, V.

Soft tissue sarcomas of the extremities: survival and patterns of failure with conservative surgery and postoperative irradiation compared to surgery alone

International Nuclear Information System (INIS)

Leibel, S.A.; Tranbaugh, R.F.; Wara, W.M.; Beckstead, J.H.; Bovill, E.G.; Phillips, T.L.

1982-01-01

Between 1960 and 1978, 81 patients received their primary treatment for localized soft tissue sarcomas of the extremities, buttock and shoulder at the University of California, San Francisco. Initial treatment consisted of surgery alone in 47 patients, planned conservative surgery followed by radiation therapy in 29 patients, and irradiation alone in five patients. The two- and five-year determinate survival for all cases was 86% and 73%, respectively. The local control rate achieved with surgery alone was related to the extent of surgery. Eighty-seven percent (14/16) of the patients undergoing amputation were locally controlled. Seventy-two percent (8/11) were treated with wide en bloc resection and had local tumor control while only 30% (6/20) having simple excision were controlled. The local control rate with surgery and postoperative irradiation was 90% (26/29). No patients treated with irradiation therapy alone were controlled. This review suggests that local tumor control achieved with limb preserving conservative surgery and postoperative irradiation is superior to limited surgery alone. The survival and patterns of failure of patients undergoing radical surgery is comparable to combined treatment with the risk-benefit ratio favoring the latter

Experimental study of mechanical response of artificial tissue models irradiated with Nd:YAG nanosecond laser pulses

Science.gov (United States)

Pérez-Gutiérrez, Francisco G.; Camacho-López, Santiago; Aguilar, Guillermo

2011-07-01

Nanosecond long laser pulses are used in medical applications where precise tissue ablation with minimal thermal and mechanical collateral damage is required. When a laser pulse is incident on a material, optical energy will be absorbed by a combination of linear and nonlinear absorption according to both: laser light irradiance and material properties. In the case of water or gels, the first results in heat generation and thermoelastic expansion; while the second results in an expanding plasma formation that launches a shock wave and a cavitation/boiling bubble. Plasma formation due to nonlinear absorption of nanosecond laser pulses is originated by a combination of multiphoton ionization and thermionic emission of free electrons, which is enhanced when the material has high linear absorption coefficient. In this work, we present three experimental approaches to study pressure transients originated when 6 ns laser pulses are incident on agar gels and water with varying linear absorption coefficient, using laser radiant exposures above and below threshold for bubble formation: (a) PVDF sensors, (b) Time-resolved shadowgraphy and (c) Time-resolved interferometry. The underlying hypothesis is that pressure transients are composed of the superposition of both: shock wave originated by hot expanding plasma resulting from nonlinear absorption of optical energy and, thermoelastic expansion originated by heat generation due to linear absorption of optical energy. The objective of this study is to carry out a comprehensive experimental analysis of the mechanical effects that result when tissue models are irradiated with nanosecond laser pulses to elucidate the relative contribution of linear and nonlinear absorption to bubble formation. Furthermore, we investigate cavitation bubble formation with temperature increments as low as 3 °C.

Vesicular thick-walled swollen hyphae in pulmonary zygomycosis.

Science.gov (United States)

Kimura, Masatomo; Ito, Hiroyuki

2009-03-01

An autopsy case of pulmonary zygomycosis in a patient with rheumatoid arthritis on immunosuppressive therapy is presented herein. There was a pulmonary cavitated infarct caused by mycotic thrombosis. Thin-walled narrow hyphae and vesicular thick-walled swollen hyphae were found on the pleural surface and in the necrotic tissue at the periphery of the cavity. Findings of such shaped fungal elements may cause erroneous histopathological diagnosis because pauciseptate broad thin-walled hyphae are usually the only detectable fungal elements in zygomycosis tissue. Although immunohistochemistry confirmed these unusual elements to be zygomycetous in the present case, it is important for the differential diagnosis to be aware that zygomycetes can form thin narrow hyphae and vesicular thick-walled swollen hyphae.

Effect of ceramic thickness and shade on mechanical properties of a resin luting agent.

Science.gov (United States)

Passos, Sheila Pestana; Kimpara, Estevão Tomomitsu; Bottino, Marco Antonio; Rizkalla, Amin S; Santos, Gildo Coelho

2014-08-01

This study aimed to investigate the influence of ceramic thickness and shade on the Knoop hardness and dynamic elastic modulus of a dual-cured resin cement. Six ceramic shades (Bleaching, A1, A2, A3, A3.5, B3) and two ceramic thicknesses (1 mm, 3 mm) were evaluated. Disk specimens (diameter: 7 mm; thickness: 2 mm) of the resin cement were light cured under a ceramic block. Light-cured specimens without the ceramic block at distances of 1 and 3 mm were also produced. The Knoop hardness number (KHN), density, and dynamic Young's moduli were determined. Statistical analysis was conducted using ANOVA and a Tukey B rank order test (p = 0.05). The bleaching 1-mm-thick group exhibited significantly higher dynamic Young's modulus. Lower dynamic Young's moduli were observed for the 3-mm-thick ceramic groups compared to bleaching 3-mm-thick group, and no difference was found among the other 3-mm groups. For the KHN, when A3.5 3-mm-thick was used, the KHN was significantly lower than bleaching and A1 1-mm-thick ceramic; however, no difference was exhibited between the thicknesses of the same shade. The dual-cured resin cement studied irradiated through the 1-mm-thick ceramic with the lightest shade (bleaching ceramic) exhibited a better elastic modulus, and there was no effect in KHN of the resin cement when light cured under different ceramic shades and thicknesses (1 and 3 mm), except when the A3.5 3-mm-thick ceramic was used. Variolink II irradiated through ceramic with the lowest chroma exhibited the highest elastic modulus; therefore, the light activation method might not be the same for all clinical situations. © 2014 by the American College of Prosthodontists.

Drosophila Wnt and STAT Define Apoptosis-Resistant Epithelial Cells for Tissue Regeneration after Irradiation.

Directory of Open Access Journals (Sweden)

Shilpi Verghese

2016-09-01

Full Text Available Drosophila melanogaster larvae irradiated with doses of ionizing radiation (IR that kill about half of the cells in larval imaginal discs still develop into viable adults. How surviving cells compensate for IR-induced cell death to produce organs of normal size and appearance remains an active area of investigation. We have identified a subpopulation of cells within the continuous epithelium of Drosophila larval wing discs that shows intrinsic resistance to IR- and drug-induced apoptosis. These cells reside in domains of high Wingless (Wg, Drosophila Wnt-1 and STAT92E (sole Drosophila signal transducer and activator of transcription [STAT] homolog activity and would normally form the hinge in the adult fly. Resistance to IR-induced apoptosis requires STAT and Wg and is mediated by transcriptional repression of the pro-apoptotic gene reaper. Lineage tracing experiments show that, following irradiation, apoptosis-resistant cells lose their identity and translocate to areas of the wing disc that suffered abundant cell death. Our findings provide a new paradigm for regeneration in which it is unnecessary to invoke special damage-resistant cell types such as stem cells. Instead, differences in gene expression within a population of genetically identical epithelial cells can create a subpopulation with greater resistance, which, following damage, survive, alter their fate, and help regenerate the tissue.

Study on residual stress across the pipes' thickness using outer surface rapid heating. Development of pipe outer surface irradiated laser stress improvement process (L-SIP)

International Nuclear Information System (INIS)

Ohta, Takahiro; Terasaki, Toshio

2009-01-01

The new process called L-SIP (outer surface irradiated Laser Stress Improvement Process) is developed to improve the tensile residual stress of the inner surface near the butt welded joints of pipes in the compression stress. The temperature gradient occurs in the thickness of pipes in heating the outer surface rapidly by laser beam. By the thermal expansion difference between the inner surface and the outer surface, the compression plastic strain generates near the outer surface and the tensile plastic strain generates near the inner surface of pipes. The compression stress occurs near the inner surface of pipes by the plastic deformation. In this paper, the theoretical equation which calculates residual stress distribution from the inherent strain distribution in the thickness of pipes is derived. And, the relation between the distribution of temperature and the residual stress in the thickness is examined for various pipes size. (1) By rapidly heating from the outer surface, the residual stress near the inner surface of the pipe is improved to the compression stress. (2) Pipes size hardly affects the distribution of the residual stress in the stainless steel pipes for piping (JISG3459). (3) The temperature rising area from the outside is smaller, the area of the compression residual stress near the inner surface becomes wider. (author)

Calculation of the kinetics of heating and structural changes in the cartilaginous tissue under the action of laser radiation

International Nuclear Information System (INIS)

Sobol', E N; Kitai, M S

1998-01-01

A theoretical model is developed for the calculation of the temperature fields and determination of the size of a zone with structural changes in the cartilaginous tissue. The model is based on a simultaneous analysis of the heat and mass transfer processes and it takes into account the bulk absorption of laser radiation by the tissue, surface evaporation of water, and temperature dependences of the diffusion coefficients. It is assumed that under the influence of a phase transition between free and bound water, caused by heating of the cartilage to 70 0 C, the proteoglycans of the cartilage matrix become mobile and, as a result of such mass transfer, structural changes are induced in the cartilaginous tissue causing relaxation of stresses or denaturation. It is shown that the maximum temperature is then reached not on the irradiated surface but at some distance from it, and that the size of the zones of structural changes (denaturation depth) depends strongly on the energy density of the laser radiation and its wavelength, on the duration of the irradiation, and on the cartilage thickness. This model makes it possible to calculate the temperature fields and the depth of structural changes in laser-induced relaxation of stresses and changes in the shape of the cartilaginous tissue. (interaction of laser radiation with matter)