Transvaginal ultrasound ovarian diathermy: sheep as an experimental model

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Pimentel Anita M

2012-01-01

Full Text Available Abstract Background Some techniques of transvaginal ovarian drilling have been previously described. Nevertheless a monopolar transvaginal ovarian cauterization, that use the expertise and safety of transvaginal puncture for oocyte captation seems to be an easier and feasible approach. The aim of this study was to develop a minimally invasive ovarian cauterization technique under transvaginal ultrasound control, and to evaluate the safety of the transvaginal ovarian monopolar cauterization, female sheep at reproductive age were used as an experimental model. Findings An experimental study was performed in a university research center. Seventeen female sheep (15 Corriedale e 2 Suffolk in reproductive age were submitted to transvaginal ovarian cauterization with a monopolar Valleylab Force 2 electrocautery. Macroscopic and microscopic lesions were assessed. Ovarian size were 1.31 cm2 ± 0,43 (Corriedale and 3.41 cm2 ± 0,64 (Suffolk. From 30 ovaries from Corriedale sheep punctured, only 3 were cauterized, presenting macroscopic and typical microscopic lesion. In the Suffolk sheep group, only one ovary was cauterized. No lesion could be found in the needle path. Conclusions This is the first experimental animal model described for ovarian cauterization needle guided by transvaginal ultrasound. The sheep does not seem to be the ideal animal model to study this technique. Another animal model, whose ovaries are better identified by transvaginal ultrasound should be sought for this technique, theoretically less invasive, before it could be offered safely to women with polycystic ovary syndrome.

Ocular lesions and experimental choline deficiency Lesiones oculares y deficiencia experimental de colina

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Georgina P. Ossani

2006-10-01

Full Text Available Previous studies have shown ocular haemorrhages in choline-deficient rats. The aim of this paper is to study further the relationship between ocular and renal lesions and biochemical alterations in rats fed a choline-deficient diet. Fifty one weanling male Wistar rats, were divided into two groups. Thirty one of them were fed a choline-deficient diet and the rest was fed a choline-supplemented diet ad libitum. Animals from both groups were killed between the fifth and the eighth day. Urea, creatinine and homocysteine concentrations in blood were determined. Eyes were used for light microscopy study; high resolution light microscopy and the study of the retina as "rétine a plat". Kidneys were studied by light microscopy. Choline-supplemented rats did not show ocular or renal lesion. Choline-deficient rats that showed renal lesions, tubular or cortical necrosis, did not always have ocular changes. There were no ocular changes in the only choline-deficient rat without renal lesion. The ocular changes consisted mainly in haemorrhage in both cameras and ciliary and vitreous bodies. Correlations between ocular and renal lesion (r=0.72, pEstudios previos han demostrado hemorragia ocular en ratas deficientes en colina. El objetivo de este trabajo es profundizar en la relación entre las alteraciones oculares, renales y bioquímicas en ratas deficientes en colina. Cincuenta y una ratas Wistar macho recién destetadas fueron divididas en dos grupos: treinta y una fueron alimentadas con una dieta colino deficiente y el resto con colina suplementada ad-libitum. Los animales de ambos grupos fueron sacrificados entre el quinto y el octavo día. Se midió la concentración de urea, creatinina y homocisteína en sangre. Los ojos fueron estudiados por microscopía de luz, microscopía óptica de alta resolución y para el estudio de la retina como retina plana. Los riñones fueron estudiados por microscopía de luz. Las ratas suplementadas con colina no

Breast lesion characterization using whole-lesion histogram analysis with stretched-exponential diffusion model.

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Liu, Chunling; Wang, Kun; Li, Xiaodan; Zhang, Jine; Ding, Jie; Spuhler, Karl; Duong, Timothy; Liang, Changhong; Huang, Chuan

2018-06-01

Diffusion-weighted imaging (DWI) has been studied in breast imaging and can provide more information about diffusion, perfusion and other physiological interests than standard pulse sequences. The stretched-exponential model has previously been shown to be more reliable than conventional DWI techniques, but different diagnostic sensitivities were found from study to study. This work investigated the characteristics of whole-lesion histogram parameters derived from the stretched-exponential diffusion model for benign and malignant breast lesions, compared them with conventional apparent diffusion coefficient (ADC), and further determined which histogram metrics can be best used to differentiate malignant from benign lesions. This was a prospective study. Seventy females were included in the study. Multi-b value DWI was performed on a 1.5T scanner. Histogram parameters of whole lesions for distributed diffusion coefficient (DDC), heterogeneity index (α), and ADC were calculated by two radiologists and compared among benign lesions, ductal carcinoma in situ (DCIS), and invasive carcinoma confirmed by pathology. Nonparametric tests were performed for comparisons among invasive carcinoma, DCIS, and benign lesions. Comparisons of receiver operating characteristic (ROC) curves were performed to show the ability to discriminate malignant from benign lesions. The majority of histogram parameters (mean/min/max, skewness/kurtosis, 10-90 th percentile values) from DDC, α, and ADC were significantly different among invasive carcinoma, DCIS, and benign lesions. DDC 10% (area under curve [AUC] = 0.931), ADC 10% (AUC = 0.893), and α mean (AUC = 0.787) were found to be the best metrics in differentiating benign from malignant tumors among all histogram parameters derived from ADC and α, respectively. The combination of DDC 10% and α mean , using logistic regression, yielded the highest sensitivity (90.2%) and specificity (95.5%). DDC 10% and α mean derived from

Radiofrequency thermal ablation of benign cystic lesion: an experimental pilot study in a porcine gallbladder model

International Nuclear Information System (INIS)

Song, Ho Taek; Rhim, Hyun Chul; Choi, Jung Bin; Oh, Jae Cheon; Cho, On Koo; Koh, Byung Hee; Kim, Yong Soo; Seo, Heung Suk; Joo, Kyung Bin

2001-01-01

To determine whether radiofrequency thermal ablation can be used to treat benign cystic lesions in a porcine gallbladder model. This experimental study of radiofrequency thermal ablation involved the use of 15 exvivo porcine gallbladders and 15-G expandable needle electrodes. To investigate optimal temperature parameters, three groups of five were designated according to target temperature:Group A: 70 deg C; Group B: 80 deg C; Group C: 90 deg C. After the target temperature was reached, ablation lasted for one minute. Gallbladder width, height and length were measured before and after ablation , and the estimated volume reduction ratios of the three groups were compared. Whether adjacent liver parenchyma around the gallbladder fossa was ablated by heat conducted from hot bile was also determined, and the thickness of the ablated area of the liver was measured. The volume reduction ratio in Group A, B and C was 42.7%, 41.7% and 42.9%, respectively (ρ>.05). In all 15 cases, gallbladder walls lost their transparency and elasticity at about 70 deg C. In nine of ten cases in Groups B and C, the hepatic capsule around the gallbladder fossa was retracted at about 80 deg C. The mean thickness of liver parenchymal damage adjacent to the gallbladder was 5.4 mm in Group B and 9.8 mm in Group C. In Group A livers, only one case showed minimal gradual parenchymal change. Microscopically, all three groups showed complete coagulation necrosis of the wall. On the basis of this feasibility study, radiofrequency thermal ablation is potentially suitable for the ultrasound-guided treatment of symptomatic cystic lesions including benign hepatic or renal cyst

Application of radiosurgical techniques to produce a primate model of brain lesions

OpenAIRE

Kunimatsu, Jun; Miyamoto, Naoki; Ishikawa, Masayori; Shirato, Hiroki; Tanaka, Masaki

2015-01-01

Behavioral analysis of subjects with discrete brain lesions provides important information about the mechanisms of various brain functions. However, it is generally difficult to experimentally produce discrete lesions in deep brain structures. Here we show that a radiosurgical technique, which is used as an alternative treatment for brain tumors and vascular malformations, is applicable to create non-invasive lesions in experimental animals for the research in systems neuroscience. We deliver...

Radiofrequency tissue ablation with cooled-tip electrodes:an experimental study in a bovine liver model on variables influencing lesion size

International Nuclear Information System (INIS)

Han, Hyun Young; Lee, Jeong Min; Kim, Chong Soo

2001-01-01

The purpose of this study was to determine the influence of various factors on the extent of thermal coagulation necrosis after radiofrequency (RF) tissue ablation using a cooled-tip electrode in bovine liver. RF ablation was induced by a monopolar 500 KHz-RF generator (CC-1; Radionics, Burlington, Mass., U.S.A.) and an 18-G cooled-tip with single or clustered electrodes. The ablation protocol involved a combination of varying current, ablation time, power output, gradual or abrupt increase of this out-put, and pulsed radiofrequency techniques. The maximum diameter of all thermal lesions which showed a color change was measured perpendicular to the electrode axis by two observers who reached their decisions by consensus. Twenty representative lesions were pathologically examined. With increasing current lesion diameter also increased, but above 1500 mA no further increase was induced. Extending the ablation time to 9 minutes for a single electrode and 15 minutes for a clustered electrode increased lesion diameter until a steady state was reached. Higher power levels caused larger lesions, but above 100 W no increase was observed. Ample exposure time coupled with a stepwise increase in power level induced a lesion larger than that resulting from an abrupt increase. Continuous pulsed RF with a high current led to increased coagulation necrosis diameter. These experimental findings may be useful thermotherapy. The data suggest that all involved factors significantly affect lesion size:if the factors are better understood, cancer thermotherapy can be better controlled

Stroke Lesions in a Large Upper Limb Rehabilitation Trial Cohort Rarely Match Lesions in Common Preclinical Models

Science.gov (United States)

Edwardson, Matthew A.; Wang, Ximing; Liu, Brent; Ding, Li; Lane, Christianne J.; Park, Caron; Nelsen, Monica A.; Jones, Theresa A; Wolf, Steven L; Winstein, Carolee J; Dromerick, Alexander W.

2017-01-01

Background Stroke patients with mild-moderate upper extremity (UE) motor impairments and minimal sensory and cognitive deficits provide a useful model to study recovery and improve rehabilitation. Laboratory-based investigators use lesioning techniques for similar goals. Objective Determine whether stroke lesions in an UE rehabilitation trial cohort match lesions from the preclinical stroke recovery models used to drive translational research. Methods Clinical neuroimages from 297 participants enrolled in the Interdisciplinary Comprehensive Arm Rehabilitation Evaluation (ICARE) study were reviewed. Images were characterized based on lesion type (ischemic or hemorrhagic), volume, vascular territory, depth (cortical gray matter, cortical white matter, subcortical), old strokes, and leukoaraiosis. Lesions were compared with those of preclinical stroke models commonly used to study upper limb recovery. Results Among the ischemic stroke participants, median infarct volume was 1.8 mL, with most lesions confined to subcortical structures (61%) including the anterior choroidal artery territory (30%) and the pons (23%). Of ICARE participants, stroke patients, but they represent a clinically and scientifically important subgroup. Compared to lesions in general stroke populations and widely-studied animal models of recovery, ICARE participants had smaller, more subcortically-based strokes. Improved preclinical-clinical translational efforts may require better alignment of lesions between preclinical and human stroke recovery models. PMID:28337932

Rapid noninvasive detection of experimental atherosclerotic lesions with novel 99mTc-labeled diadenosine tetraphosphates

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Elmaleh, David R.; Narula, Jagat; Babich, John W.; Petrov, Artiom; Fischman, Alan J.; Khaw, Ban-An; Rapaport, Eliezer; Zamecnik, Paul C.

1998-01-01

The development of a noninvasive imaging procedure for identifying atherosclerotic lesions is extremely important for the clinical management of patients with coronary artery and peripheral vascular disease. Although numerous radiopharmaceuticals have been proposed for this purpose, none has demonstrated the diagnostic accuracy required to replace invasive angiography. In this report, we used the radiolabeled purine analog, 99mTc diadenosine tetraphosphate (Ap4A; AppppA, P1,P4-di(adenosine-5′)-tetraphosphate) and its analogue 99mTc AppCHClppA for imaging experimental atherosclerotic lesions in New Zealand White rabbits. Serial gamma camera images were obtained after intravenous injection of the radiolabeled dinucleotides. After acquiring the final images, the animals were sacrificed, ex vivo images of the aortas were recorded, and biodistribution was measured. 99mTc-Ap4A and 99mTc AppCHClppA accumulated rapidly in atherosclerotic abdominal aorta, and lesions were clearly visible within 30 min after injection in all animals that were studied. Both radiopharmaceuticals were retained in the lesions for 3 hr, and the peak lesion to normal vessel ratio was 7.4 to 1. Neither of the purine analogs showed significant accumulation in the abdominal aorta of normal (control) rabbits. The excised aortas showed lesion patterns that were highly correlated with the in vivo and ex vivo imaging results. The present study demonstrates that purine receptors are up-regulated in experimental atherosclerotic lesions and 99mTc-labeled purine analogs have potential for rapid noninvasive detection of plaque formation. PMID:9435254

Generation of connectivity-preserving surface models of multiple sclerosis lesions.

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Meruvia-Pastor, Oscar; Xiao, Mei; Soh, Jung; Sensen, Christoph W

2011-01-01

Progression of multiple sclerosis (MS) results in brain lesions caused by white matter inflammation. MS lesions have various shapes, sizes and locations, affecting cognitive abilities of patients to different extents. To facilitate the visualization of the brain lesion distribution, we have developed a software tool to build 3D surface models of MS lesions. This tool allows users to create 3D models of lesions quickly and to visualize the lesions and brain tissues using various visual attributes and configurations. The software package is based on breadth-first search based 3D connected component analysis and a 3D flood-fill based region growing algorithm to generate 3D models from binary or non-binary segmented medical image stacks.

Longitudinal in vivo magnetic resonance imaging studies in experimental allergic encephalomyelitis: effect of a neurotrophic treatment on cortical lesion development

International Nuclear Information System (INIS)

Gispen, W.H.; Nicolay, K.; Verhaagen, J.; Muller, H.J.; Duckers, H.J.

1997-01-01

Proton magnetic resonance imaging enables non-invasive monitoring of lesion formation in multiple sclerosis and has an important role in assessing the potential effects of therapy. T2-weighted and short τ inversion recovery magnetic resonance imaging were used to assess the effect of a neurotrophic adrenocorticotrophic hormone 4-9 analogue [H-Met(O 2 )-Glu-His-Phe-d-Lys-Phe-OH] on the volume of lesions in the brains of rats suffering from chronic experimental allergic encephalomyelitis, an animal equivalent of multiple sclerosis. Lesion volume was monitored during a five-month period. Magnetic resonance imaging indicated that treatment with the adrenocorticotrophic hormone 4-9 analogue significantly reduced the lesion volume by 84 and 85% 10 and 20 weeks after lesion induction, respectively. Furthermore, peptide treatment significantly reduced chronic experimental allergic encephalomyelitis-related neurological symptoms during the chronic phase of the disease (week 3 until week 20 after lesion induction). Both functional and morphological recovery were considerably advanced by peptide treatment. Twenty weeks after lesion induction rats with chronic experimental allergic encephalomyelitis were killed for histological analysis, to correlate magnetic resonance imaging findings with morphological changes. The regions of abnormally high signal intensities on T2-weighted magnetic resonance images coincided with areas of demyelination and concomitant widespread inflammatory infiltration, oedema formation and enlarged ventricles.The improved neurological status and the 84% reduction in the lesion volume in the cerebrum of rats chronic experimental allergic encephalomyelitis point to the potential value of trophic peptides in the development of strategies for limiting the damage caused by central demyelinating lesions in syndromes such as multiple sclerosis. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

Longitudinal in vivo magnetic resonance imaging studies in experimental allergic encephalomyelitis: effect of a neurotrophic treatment on cortical lesion development

Energy Technology Data Exchange (ETDEWEB)

Gispen, W.H. [Rudolf Magnus Institute for Neurosciences, Department of Medical Pharmacology, Medical Faculty, Utrecht University Utrecht (Netherlands); Nicolay, K. [Department of in vivo NMR, Bijvoet Center, Utrecht University Utrecht (Netherlands); Verhaagen, J. [Rudolf Magnus Institute for Neurosciences, Department of Medical Pharmacology, Medical Faculty, Utrecht University Utrecht (Netherlands); Muller, H.J. [Department of in vivo NMR, Bijvoet Center, Utrecht University Utrecht (Netherlands); Duckers, H.J. [Rudolf Magnus Institute for Neurosciences, Department of Medical Pharmacology, Medical Faculty, Utrecht University Utrecht (Netherlands)

1997-02-14

Proton magnetic resonance imaging enables non-invasive monitoring of lesion formation in multiple sclerosis and has an important role in assessing the potential effects of therapy. T2-weighted and short {tau} inversion recovery magnetic resonance imaging were used to assess the effect of a neurotrophic adrenocorticotrophic hormone{sub 4-9} analogue [H-Met(O{sub 2})-Glu-His-Phe-d-Lys-Phe-OH] on the volume of lesions in the brains of rats suffering from chronic experimental allergic encephalomyelitis, an animal equivalent of multiple sclerosis. Lesion volume was monitored during a five-month period. Magnetic resonance imaging indicated that treatment with the adrenocorticotrophic hormone{sub 4-9} analogue significantly reduced the lesion volume by 84 and 85% 10 and 20 weeks after lesion induction, respectively. Furthermore, peptide treatment significantly reduced chronic experimental allergic encephalomyelitis-related neurological symptoms during the chronic phase of the disease (week 3 until week 20 after lesion induction). Both functional and morphological recovery were considerably advanced by peptide treatment. Twenty weeks after lesion induction rats with chronic experimental allergic encephalomyelitis were killed for histological analysis, to correlate magnetic resonance imaging findings with morphological changes. The regions of abnormally high signal intensities on T2-weighted magnetic resonance images coincided with areas of demyelination and concomitant widespread inflammatory infiltration, oedema formation and enlarged ventricles.The improved neurological status and the 84% reduction in the lesion volume in the cerebrum of rats chronic experimental allergic encephalomyelitis point to the potential value of trophic peptides in the development of strategies for limiting the damage caused by central demyelinating lesions in syndromes such as multiple sclerosis. (Copyright (c) 1997 Elsevier Science B.V., Amsterdam. All rights reserved.)

Chronological changes in the CT appearance of experimental radiofrequency thalamic lesions in dogs

International Nuclear Information System (INIS)

Ebisutani, Daizo; Makino, Akira; Matsumoto, Keizo; Ii, Kunio

1987-01-01

The location and extent of thalamic lesions following thalamotomy have been determined by the monopolar radiofrequency method. They can sometimes be identified in CT images as low-density areas, but also exceptionally high-density areas. However, this low-density area changes with time from a larger one in the acute stage to a smaller spot in the chronic stage, and sometimes it disappears within three months after the operation. It is the purpose of this study to elucidate the proper timing for the scanning for the anatomical mapping of the lesion in chronologically varying images of the lesions. Stereotactic experimental radiofrequency lesions were created in the thalamus of 35 mongrel dogs at 70 deg C for 120 sec. CT images of the brain were obtained at Days 0, 3, 7, 10, 14, 21 and 60. The lesions of the specimens and CT images tended to grow from Day 0 to Day 3, and then to grow smaller to Day 60. The area of the thalamus was measured in each specimen by means of coronal cutting. The thalamus of the lesion side was swollen from Day 0 to Day 10, but it became almost equal to that of the non-lesion side between Day 14 and Day 21. Then, the thalamus of the lesion side became atrophic. The mass effects with a ventricular deformity and a midline shift on CT images were diminished at Day 14 in most cases. The lesion areas at Day 14 corresponded to the contrast-enhanced area more than to that of the plain CT histologically. These results suggest that a lesion demonstrated by CE-CT scans at Day 14 would be suitable for anatomical mapping. (author)

[Mechanistic modelling allows to assess pathways of DNA lesion interactions underlying chromosome aberration formation].

Science.gov (United States)

Eĭdel'man, Iu A; Slanina, S V; Sal'nikov, I V; Andreev, S G

2012-12-01

The knowledge of radiation-induced chromosomal aberration (CA) mechanisms is required in many fields of radiation genetics, radiation biology, biodosimetry, etc. However, these mechanisms are yet to be quantitatively characterised. One of the reasons is that the relationships between primary lesions of DNA/chromatin/chromosomes and dose-response curves for CA are unknown because the pathways of lesion interactions in an interphase nucleus are currently inaccessible for direct experimental observation. This article aims for the comparative analysis of two principally different scenarios of formation of simple and complex interchromosomal exchange aberrations: by lesion interactions at chromosome territories' surface vs. in the whole space of the nucleus. The analysis was based on quantitative mechanistic modelling of different levels of structures and processes involved in CA formation: chromosome structure in an interphase nucleus, induction, repair and interactions of DNA lesions. It was shown that the restricted diffusion of chromosomal loci, predicted by computational modelling of chromosome organization, results in lesion interactions in the whole space of the nucleus being impossible. At the same time, predicted features of subchromosomal dynamics agrees well with in vivo observations and does not contradict the mechanism of CA formation at the surface of chromosome territories. On the other hand, the "surface mechanism" of CA formation, despite having certain qualities, proved to be insufficient to explain high frequency of complex exchange aberrations observed by mFISH technique. The alternative mechanism, CA formation on nuclear centres is expected to be sufficient to explain frequent complex exchanges.

REAC regenerative treatment efficacy in experimental chondral lesions: a pilot study on ovine animal model

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Sanna Passino E

2017-09-01

Full Text Available Eraldo Sanna Passino,1,2 Stefano Rocca,1 Sabrina Caggiu,1 Nicolò Columbano,1,2 Alessandro Castagna,3 Vania Fontani,3–5 Salvatore Rinaldi3–51Department of Veterinary Medicine, University of Sassari, Sassari, Italy; 2Comparative Surgery Research Laboratory, University of Sassari, Sassari, Italy; 3Department of Regenerative Medicine, Rinaldi Fontani Institute, Florence, Italy; 4Research Department, Rinaldi Fontani Foundation, Florence, Italy; 5Research Department, IRF Shanghai Biomedical Sciences, Shanghai, People’s Republic of China Abstract: Radioelectric asymmetric conveyor (REAC technology is a platform designed to optimize cell polarity. Cell polarity is a universal biological phenomenon that is implicated in cell differentiation, proliferation, morphogenesis, aging, and rejuvenation. In this work, we investigate a timing and administration protocol for tissue optimization regenerative treatment type C, in order to treat aging-related chondral damage or injuries and gain insights into regenerative processes of articular cartilage in humans. The chondral lesion produced in this study in an animal model (6 knee joints of 4 adult sheep was 6 mm in diameter and about 2 mm deep. These lesions, which did not involve subchondral bone, tend to increase in size and depth and are not completely repaired with normal hyaline articular cartilage since adult articular cartilage is avascular and has a very slow turnover at the cellular and molecular level. Moreover, the hydration of articular cartilage is reduced with aging and with decreased mitotic activity, synthesis, and population size of chondrocytes. Six months posttreatment, lesions appeared filled, though not completely, with newly generated tissue of the light opalescent color of healthy articular cartilage, which otherwise covered the underlying subchondral bone. The newly formed tissue surface appeared to be quite regular. Nearly complete regeneration of subchondral bone occurred, with

Experimental type 2 diabetes mellitus and acetaminophen toxic lesions: glutathione system indices changes

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Olga Furka

2017-11-01

Full Text Available Background. The goal of the research was to study the effect of acetaminophen on major glutathione part of antioxidant system indices in liver homogenate of rats with type 2 diabetes mellitus in time dynamics. Materials and methods. We conducted two series of experiments. In the first series toxic lesion was caused by a single intragastric administration of acetaminophen suspension in 2 % starch solution to animals in a dose of 1250 mg/kg (1/2 LD50. In the second series  the suspension of acetaminophen in 2 % starch solution in a dose of 55 mg/kg was given, which corresponds to the highest therapeutic dose during 7 days. Non-genetic form of experimental type 2 diabetes mellitus was modeled by Islam S., Choi H. method (2007. Activity of glutathione peroxidase (GPx and glutathione reductase (GR, and contents of reduced glutathione (GSH were determined in liver homogenate. Results. The obtained results have shown that GR and GPx activity actively decreased after acetaminophen administration in higher therapeutic doses to rats with type 2 DM. However, the changes were less pronounced than in rats with type 2 DM and acute acetaminophen toxic lesions. Conclusion. Results of the research have shown that acetaminophen administration to rats with type 2 DM causes a significant violation of compensatory mechanisms, especially of the enzyme and nonenzyme parts of antioxidant system.

Multiple-lesion track-structure model

International Nuclear Information System (INIS)

Wilson, J.W.; Cucinotta, F.A.; Shinn, J.L.

1992-03-01

A multilesion cell kinetic model is derived, and radiation kinetic coefficients are related to the Katz track structure model. The repair-related coefficients are determined from the delayed plating experiments of Yang et al. for the C3H10T1/2 cell system. The model agrees well with the x ray and heavy ion experiments of Yang et al. for the immediate plating, delaying plating, and fractionated exposure protocols employed by Yang. A study is made of the effects of target fragments in energetic proton exposures and of the repair-deficient target-fragment-induced lesions

Temporal and Spatial Characterization of Gait Pattern in Rodents as an Animal model of Cerebrovascular Lesion

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Jaison D Cucarián

2017-09-01

Full Text Available Animal experimentation is crucial for the advance in the understanding of pathophysiological mechanisms and their application on both clinical diagnosis and neuro-rehabilitation. Particularly, rodent brain lesion is commonly used in the modeling of locomotor, somatosensory and cognitive symptoms. The automated rodent gait analysis has been proposed as a tool for studying locomotor and sensory abilities and its use includes the identification of functional alterations, structural adaptations as well as neuro-rehabilitation mechanisms. From that standpoint, the effectiveness of many therapeutic intervention (i.e. physical exercises has been documented in rodents and humans. The translation from experimental data to clinical conditions requires the continuous collaboration and feedback between researchers and health clinicians looking for the selection of the best rehabilitation protocols obtained from animal research. Here we will show some locomotor alterations, the traditional methods used to assess motor dysfunction and gait abnormalities in rodent models with stroke. The aim of this review is to show some motor deficiencies and some methods used to establish gait disturbances in rodents with cerebrovascular lesion. The review included the search of defined terms (MeSH in PychINFO, Medline and Web of Science, between January 2000 and January 2017. Qualitative and narrative reports, dissertations, end course works and conference resumes were discarded. The review focuses on some clinical signs, their effects on rodent locomotor activity, some methodologies used to create lesion and to study motor function, some assessment methods and some translational aspects.

Animal model of atherosclerosis using rabbit experimentally induced by combination of X-ray and hypercholesterolemia

International Nuclear Information System (INIS)

Ishiyama, Tomotoshi; Sawai, Takashi; Okuma, Tsuneo; Mori, Shozo

1995-01-01

An attempt was made to prepare an animal model of atherosclerosis similar to human lesions. The experimental animals were male Japanese white rabbits weighting about 2 kg. Hypercholesterolemia was experimentally induced by giving a 1% cholesterol diet. Four weeks later, a single dose of 45 Gy was delivered to the femur to produce vascular changes. Soon after irradiation, immunohistochemical examination revealed the adhesion and invasion of macrophages to endothelial cells, followed by accumulation of foam cells and thickness of the intimal plaques. Three months after irradiation, these thickened plaques became fibrotic, calcified, and necrotic. The tunica media was thinned and the internal elastic lamella was destroyed. Irradiated arteries exhibited not only severe narrowing of the lumen but also aneurysmal dilation and the lesions of the irradiated arteries resembled human atherosclerosis. In conclusion, the atherosclerotic model produced by combining experimental hypercholesterolemia and X-ray irradiaiton may serve as a useful model for studies on atherosclerosis because it can be prepared with no need of complicated or time-consuming procedures. (N.K.)

99mTc human IgG radiolabelled by HYNIC. Biodistribution and scintigraphy of experimentally induced inflammatory lesions in animal model

International Nuclear Information System (INIS)

Karczmarczyk, U.; Markiewicz, A.; Mikolajczak, R.; Michalik, J.; Lisiak, E.; Bilski, M.; Pietrzykowski, J.

2004-01-01

Our goal was the efficient labelling of highly purified human gammaglobulin. This radioactive protein fraction can be used as a basic compound of radiopharmaceutical formulation for inflammation lesion diagnosis. This application was experimentally illustrated in animal models with artificially induced inflammatory lesions after turpentine oil injection into mouse leg muscle. Hydrazine nicotinamine derivative of human gammaglobulin (IgG-HYNIC) was synthesized according to Abrams method. The radionuclide: technetium 99mT c has been introduced into protein molecules by indirect method incorporation in phosphate buffer, pH 7.4, in the presence of stannous chloride as a reducing agent for sodium pertechnetate, and EDTA as a coligand. Radiochemical purity was estimated by thin layer chromatography. The stability of labelled IgG-HYNIC derivative in human serum in presence of copper, cobalt, iron and manganese salts was analyzed by HPLC method (BioSEP SEC 4000, eluent: 0.1mol/L phosphate). Inflammation lesions were induced in Balb/3 mice muscles by injection of 0.2 ml turpentine oil into the leg muscle. Five days later, inflammation lesions were visualized by hIgG-HYNIC- 99mT c injections. The tracer accumulation in tissue was evaluated by gamma camera at 1 to 24 hour intervals. Efficiency of technetium 99mT c human gammaglobulin labelling (pH 7.4, temp. 37 o C) was strictly dependant on ligand and coligand presence in the reaction mixture. Labelling of IgG molecules without any supplements resulted in very low efficiency, never exceeding the range of 5%. Presence of EDTA or hydrazine nicotinamide (HYNIC) conjugated with IgG increased radiolabelling efficiency to 50%. IgG-HYNIC derivative in EDTA presence enables us to reach value above 95% radiochemical purity. Stability of IgG-HYNIC derivative labelled with technetium 99mT c decreased rapidly in serum in time - up to 70% of initial value in 30 minutes and only 20% during further 4 hr incubation. This means that as much

Evaluation of experimental cartilage lesions with ultrahigh-resolution multi-slice-CT in comparison to histology

International Nuclear Information System (INIS)

Stork, A.; Kemper, J.; Begemann, P. G. C.; Habermann, C.R.; Adam, G.; Priemel, M.; Kummer, T.; Amling, M.

2004-01-01

Purpose: histologic validation of ultrahigh-resolution multislice (MS)-CT for the evaluation of focal, experimental cartilage lesions with special regard to the subchondral bone. Testing of micro-CT (μCT) as alternative reference standard. Methods: 32 experimental cartilage lesions in bovine patellae were imaged surrounded by air (MS-CT-air) and immersed in a contrast material solution (MS-CT-CM) with MS-CT (collimation 2 x 0,5 mm). After the μCT (8 μm-voxelsite) examination in three specimen and histologic work-up of 29 specimen two radiologist graded the defects on MS-CT images in consensus (subchondral bone involvement yes or no) and results were compared to the results of histomorphometry and μCT. Results: the MS-CT-air and -CM had an accuracy of 94% (30/32) and 88% (28/32), respectively. MS-CT-air led to one false-positive (remaining cartilage: = 0,1 mm) and false-negative result, each. MS-CT-CM showed false-positive results if the remaining cartilage was [de

Effect of an estrogen-deficient state and alendronate therapy on bone loss resulting from experimental periapical lesions in rats.

Science.gov (United States)

Xiong, Haofei; Peng, Bin; Wei, Lili; Zhang, Xiaolei; Wang, Li

2007-11-01

The aim of the research was to evaluate the impact of an estrogen-deficient state and alendronate (ALD) therapy on bone loss resulting from experimental periapical lesions in rats. Periapical lesions were induced on ovariectomized (OVX) and sham-ovariectomized (Sham) rats. After sample preparation, histologic and radiographic examination for periapical bone loss area and an enzyme histochemical test for tartrate-resistant acid phosphatase (TRAP) were performed. The results showed that OVX significantly increased bone loss resulting from periradicular lesions. After daily subcutaneous injection of ALD, the bone loss area and the number of TRAP-positive cells (osteoclasts) were reduced. These findings suggested that alendronate may protect against increased bone loss from experimental periapical lesions in estrogen-deficient rats. Given recent recognition of adverse effects of bisphosphonates, including an increased risk for osteonecrosis, the findings from this study should not be interpreted as a new indication for ALD treatment. However, they may offer insight into understanding and predicting outcomes in female postmenopausal patients already on ALD therapy for medical indications.

Statistical models for quantifying diagnostic accuracy with multiple lesions per patient

NARCIS (Netherlands)

Zwinderman, Aeilko H.; Glas, Afina S.; Bossuyt, Patrick M.; Florie, Jasper; Bipat, Shandra; Stoker, Jaap

2008-01-01

We propose random-effects models to summarize and quantify the accuracy of the diagnosis of multiple lesions on a single image without assuming independence between lesions. The number of false-positive lesions was assumed to be distributed as a Poisson mixture, and the proportion of true-positive

Laser beams hazards. Experimental determination of a laser ocular lesion threshold

International Nuclear Information System (INIS)

Courant, D.; Court, L.; Gueneau, G.; Bagot, J.D.; Abadie, B.; Brouillet, B.; Laborde, G.; Duchene, A.

1984-10-01

The risks due to the use of laser have called for the definition of exposure limits. The determination of these values requires the knowledge of the physical parameters of exposure and both the anatomical and the physiological properties of the skin and the eye. The parameters of the mechanisms involved in the biological effects of laser beams, the concept of damage criteria and the experimental results found in the literature are first discussed. The main parameter of the beam determining the injury: wavelength, time and the size of the image are then analysed. Some examples of experimental determinations of laser ocular lesion thresholds, carried out on the retinae of the rabbit and the monkey, emphasize, the difficulties met in the determination of the exposure limits. These experiments involve the effect of laser beam in the visible spectrum. Several techniques are compared: a direct ophthalmoscopic observation, a method with fluorescein angiography, a histologic study with light microscopy and an electrophysiological study. The results show that the determination of exposure limits is chiefly a function of the experimental techniques used, the delay of the observation after exposure and the probability of risk selected. The experimental results demonstrate the importance of these parameters and bring into light the uncertainties of the present guidelines [fr

Development of a unilaterally-lesioned 6-OHDA mouse model of Parkinson's disease.

Science.gov (United States)

Thiele, Sherri L; Warre, Ruth; Nash, Joanne E

2012-02-14

The unilaterally lesioned 6-hyroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease (PD) has proved to be invaluable in advancing our understanding of the mechanisms underlying parkinsonian symptoms, since it recapitulates the changes in basal ganglia circuitry and pharmacology observed in parkinsonian patients(1-4). However, the precise cellular and molecular changes occurring at cortico-striatal synapses of the output pathways within the striatum, which is the major input region of the basal ganglia remain elusive, and this is believed to be site where pathological abnormalities underlying parkinsonian symptoms arise(3,5). In PD, understanding the mechanisms underlying changes in basal ganglia circuitry following degeneration of the nigro-striatal pathway has been greatly advanced by the development of bacterial artificial chromosome (BAC) mice over-expressing green fluorescent proteins driven by promoters specific for the two striatal output pathways (direct pathway: eGFP-D1; indirect pathway: eGFP-D2 and eGFP-A2a)(8), allowing them to be studied in isolation. For example, recent studies have suggested that there are pathological changes in synaptic plasticity in parkinsonian mice(9,10). However, these studies utilised juvenile mice and acute models of parkinsonism. It is unclear whether the changes described in adult rats with stable 6-OHDA lesions also occur in these models. Other groups have attempted to generate a stable unilaterally-lesioned 6-OHDA adult mouse model of PD by lesioning the medial forebrain bundle (MFB), unfortunately, the mortality rate in this study was extremely high, with only 14% surviving the surgery for 21 days or longer(11). More recent studies have generated intra-nigral lesions with both a low mortality rate >80% loss of dopaminergic neurons, however expression of L-DOPA induced dyskinesia(11,12,13,14) was variable in these studies. Another well established mouse model of PD is the MPTP-lesioned mouse(15). Whilst this

Radio-frequency ablation in patients with malignant hepatic tumor and experimental model: comparison of expandable needle and water-cooled needle

Energy Technology Data Exchange (ETDEWEB)

Moon, Yong Ju; Jeong, Yong Yeon; Kim, Jeong; Yim, Nam yeol; Kang, Heoung Keun [School of Medicine, Chonnam National Univ., Gwangju (Korea, Republic of); Kim, Eun Ha; Yoon, Kwon Ha [School of Medicine, Wonkwang Univ., Iksan (Korea, Republic of); Ko, Seog Wan [School of Medicine, Chonbuk National Univ., Jeonju (Korea, Republic of)

2004-12-01

The purpose of this study was to compare the shape and volume of the radio-frequency induced lesions produced by two commercially available radio-frequency ablation (RFA) systems, the expandable and cooled-tip needles, in clinical patients and an experimental model. A twelve-array anchor expandable needle electrode and a single cooled-tip needle electrode were used to treat hepatic tumors with a single session in 23 patients (20 hepatocellular carcinomas and 3 hepatic metastases) and fourteen patients (10 hepatocellular carcinomas and 4 hepatic metastases), respectively. Twenty RFA induced lesions were created with each system in 10 explanted bovine livers. The shape of the RFA induced lesions were divided into oval lesions along or perpendicular to the axis of the electrode and spherical lesions, and we then calculated the volumes of the RFA induced lesions. Fourteen (61%) lesions of the 23 patients treated with the expandable system were oval perpendicular to the axis of the electrode and nine (39%) of the lesions were spherical. All the lesions (100%) of the 14 patients treated with the cooled-tip needle were ovaI along the axis of the electrode. In the ex vivo bovine livers, the shape of the all RFA induced lesions was oval perpendicular to the axis of the electrode for the expandable needle, and oval along the axis of the electrode for the cooled-tip needle. The mean diameter and volume of the RFA induced lesions in the patients were 3.35{+-}0.56 cm and 19.9{+-}6.53 cm{sup 3}, respectively, for the expandable needle and 3.58{+-}0.78 cm and 23.19{+-}5.27 cm{sup 3}, respectively, for the cooled-tip needle. In the ex vivo model, the mean diameter and volume of RFA induced lesions were 3.41{+-}0.59 cm and 26.59{+-}8.02 cm{sup 3}, respectively, for the expandable needle, and 4.04{+-}0.65 cm and 33.82{+-}6.16 cm{sup 3}, respectively, for the cooled-tip needle (p <0.05). These results indicate that the shape of RFA induced lesions with the expandable needle were oval

Fish biomarkers for environmental monitoring: An integrated model supporting enzyme activity and histopathological lesions

Science.gov (United States)

Neta, Raimunda Nonata Fortes Carvalho; Torres Junior, Audalio Rebelo

2014-10-01

We present a mathematical model describing the association between glutathione-S-transferase activity and brachial lesions in the catfish, Sciades herzbergii (Ariidae) from a polluted port. The catfish were sampled from a port known to be contaminated with heavy metals and organic compounds and from a natural reserve in São Marcos Bay, Brazil. Two biomarkers, hepatic glutathione S-transferase (GST) activity and histopathological lesions, in gills tissue were measured. The values for GST activity were modeled with the occurrence of branchial lesions by fitting a third order polynomial. Results from the mathematical model indicate that GST activity has a strong polynomial relationship with the occurrence of branchial lesions in both the wet and the dry seasons, but only at the polluted port site. The model developed in this study indicates that branchial and hepatic lesions are initiated when GST activity reaches 2.15 μmol min-1 mg protein-1. Beyond this limit, GST activity decreased to very low levels and irreversible histopathological lesions occurred. This mathematical model provides a realistic approach to analyze predictive biomarkers of environmental health status.

Persistent activation of microglia is associated with neuronal dysfunction of callosal projecting pathways and multiple sclerosis-like lesions in relapsing--remitting experimental autoimmune encephalomyelitis

DEFF Research Database (Denmark)

Rasmussen, Stine; Wang, Yue; Kivisäkk, Pia

2007-01-01

callosal projecting neurons. There was significant impairment of retrograde labeling of NeuN-positive callosal projecting neurons and reduction in the labelling of their transcallosal axons. These data demonstrate a novel paradigm of cortical and callosal neuropathology in a mouse model of MS, perpetuated......Cortical pathology, callosal atrophy and axonal loss are substrates of progression in multiple sclerosis (MS). Here we describe cortical, periventricular subcortical lesions and callosal demyelination in relapsing-remitting experimental autoimmune encephalomyelitis in SJL mice that are similar...... to lesions found in MS. Unlike the T-cell infiltrates that peak during acute disease, we found that microglia activation persists through the chronic disease phase. Microglia activation correlated with abnormal phosphorylation of neurofilaments in the cortex and stripping of synaptic proteins in cortical...

Simultaneous Whole-Brain Segmentation and White Matter Lesion Detection Using Contrast-Adaptive Probabilistic Models

DEFF Research Database (Denmark)

Puonti, Oula; Van Leemput, Koen

2016-01-01

In this paper we propose a new generative model for simultaneous brain parcellation and white matter lesion segmentation from multi-contrast magnetic resonance images. The method combines an existing whole-brain segmentation technique with a novel spatial lesion model based on a convolutional...... restricted Boltzmann machine. Unlike current state-of-the-art lesion detection techniques based on discriminative modeling, the proposed method is not tuned to one specific scanner or imaging protocol, and simultaneously segments dozens of neuroanatomical structures. Experiments on a public benchmark dataset...... in multiple sclerosis indicate that the method’s lesion segmentation accuracy compares well to that of the current state-of-the-art in the field, while additionally providing robust whole-brain segmentations....

Proangiogenic Tie2+ Macrophages Infiltrate Human and Murine Endometriotic Lesions and Dictate Their Growth in a Mouse Model of the Disease

Science.gov (United States)

Capobianco, Annalisa; Monno, Antonella; Cottone, Lucia; Venneri, Mary Anna; Biziato, Daniela; Di Puppo, Francesca; Ferrari, Stefano; De Palma, Michele; Manfredi, Angelo A.; Rovere-Querini, Patrizia

2011-01-01

Endometriosis affects women of reproductive age, causing infertility and pain. Although immune cells are recruited in endometriotic lesions, their role is unclear. Tie2-expressing macrophages (TEMs) have nonredundant functions in promoting angiogenesis and growth of experimental tumors. Here we show that human TEMs infiltrate areas surrounding newly formed endometriotic blood vessels. We set up an ad hoc mouse model in which TEMs, and not Tie2-expressing endothelial cells, are targeted. We transplanted in wild-type recipients bone marrow cells expressing a suicide gene (Herpes simplex virus type 1 thymidine kinase) under the Tie2 promoter/enhancer. TEMs infiltrated endometriotic lesions. TEM depletion by ganciclovir administration arrested the growth of established lesions, without toxicity. Lesion architecture was disrupted, with: i) loss of glandular organization, ii) reduced neovascularization, and iii) activation of caspase 3 in CD31+ endothelial cells. Thus, TEMs are important for maintaining the viability of newly formed vessels and represent a potential therapeutic target in endometriosis. PMID:21924227

[Transgastric laparo-endoscopic approach for difficult access lesions. Experimental mode].

Science.gov (United States)

Tapia-Vega, Marcel Adalid; Morales-Chávez, Carlos Ernesto; Aguirre-Olmedo, Itzé; Cuendis-Velázquez, Adolfo; Rojano-Rodríguez, Martín Edgardo; Cárdenas-Lailson, Luis Eduardo

2014-01-01

Gastric neoplasms can be treated by laparoscopy in a safe and efficient way. Some lesions are not accessible to laparoscopic surgery due to their location. A transgastric approach is proposed as an alternative. Show the results with the application of an endoscopic laparotomy in an animal model that maintains functional anatomy, to resect the posterior gastric neoplasms of the stomach wall, close to the cardia and pre-pyloric region. The laparo-endoscopic technique for resection of gastric neoplasms located in the posterior wall was developed in twelve pigs at the Hospital General Gea González from May to December 2011. An endoscopy was performed to establish the site of insertion of intragastric trocars. Three gastrotomies were made in the anterior wall; under endoscopic and laparoscopic vision the trocars were inserted. The stomach was insufflated with CO2. The lesion was resected maintaining a 20 mm circumferencial margin. The gastrotomies were sutured. The statistic analysis was made with t Student and exact Fisher tests. One-hundred percent of resections were achieved in an average time of 102.33 minutes (± 4.50). Two complications and no transoperatory deceases occurred. The technique we describe allows an appropriate approach to gastric lesions located in the posterior wall, those near to the esophagogastric juntion and the prepiloric region, due to the excellent exposure managed by working inside the stomach with a laparoscopic vision and the two intragastric movile ports. The laparoscopic transgastric approach is feasible and safe for the resection of gastric neoplasms located in the posterior wall, those close to the esophago-gastric junction, and the pre-pyloric region.

Premalignant Lesions in the Kidney

Directory of Open Access Journals (Sweden)

Ziva Kirkali

2001-01-01

Full Text Available Renal cell carcinoma (RCC is the most malignant urologic disease. Different lesions, such as dysplasia in the tubules adjacent to RCC, atypical hyperplasia in the cyst epithelium of von Hippel-Lindau syndrome, and adenoma have been described for a number of years as possible premalignant changes or precursor lesions of RCC. In two recent papers, kidneys adjacent to RCC or removed from other causes were analyzed, and dysplastic lesions were identified and defined in detail. Currently renal intraepithelial neoplasia (RIN is the proposed term for classification. The criteria for a lesion to be defined as premalignant are (1 morphological similarity; (2 spatial association; (3 development of microinvasive carcinoma; (4 higher frequency, severity, and extent then invasive carcinoma; (5 progression to invasive cancer; and (6 similar genetic alterations. RIN resembles the neoplastic cells of RCC. There is spatial association. Progression to invasive carcinoma is described in experimental cancer models, and in some human renal tumors. Similar molecular alterations are found in some putative premalignant changes. The treatment for RCC is radical or partial nephrectomy. Preneoplastic lesions may remain in the renal remnant in patients treated by partial nephrectomy and may be the source of local recurrences. RIN seems to be a biologic precursor of some RCCs and warrants further investigation. Interpretation and reporting of these lesions would reveal important resources for the biological nature and clinical significance. The management of RIN diagnosed in a renal biopsy and partial nephrectomy needs to be answered.

Evaluation of radiology as a tool to diagnose pulmonic lesions in calves, for example prior to experimental infection studies

DEFF Research Database (Denmark)

Tegtmeier, Conny; Arnbjerg, J.

2000-01-01

The aim of the study was to evaluate radiology as a technique to visualize pulmonary lesions in young calves, e.g. as a selection criterion for research animals in order to eliminate animals with lung lesions Drier to experimental studies of pneumonia. Five calves with acute clinical signs...... of pneumonia were included in a direct comparative study of radiological and post mortem findings. Also, a number of animals with no signs of pneumonia were included as controls. The study revealed good agreement between the radiological and post mortem findings. Thus, in conclusion, radiology should...

Gastroprotective effect of the ethanolic extract of Parkia platycephala Benth. leaves against acute gastric lesion models in rodents

Directory of Open Access Journals (Sweden)

Hélio B Fernandes

2010-01-01

Full Text Available Parkia platycephala Benth. (Leguminosae - Mimosoideae, popularly known as "visgueira", fava bean tree or "fava-de-bolota", is widely found in the Northern and Northeastern regions of Brazil. Its pods are used as cattle food supplement in the drought period. Compounds with a gastroprotective activity were obtained from the genus Parkia. Therefore, this study aimed at investigating the gastroprotective effect of the ethanolic extract of Parkia platycephala Benth. leaves (Pp-EtOH, as well as evaluating its possible mechanisms of action in experimental ulcer induction models. Lesions were induced by absolute ethanol, ethanol-HCl, ischemia-reperfusion and indomethacin in rodents. Pp-EtOH showed a protective effect in the lesion models (66, 48 and 52 %, respectively, but it was not able to protect gastric mucosa against indomethacin-induced lesions. Results show a possible participation of the NO-synthase pathway in the gastroprotection and an antioxidant activity, by the increase of the catalase activity. The participation of prostaglandins and potassium channels sensitive to ATP in the gastroprotective effect of Pp-EtOH seems less likely to occur. More comprehensive studies, therefore, should be carried out to elucidate the antiulcerative effects of this promising natural product against this gastrointestinal disorder.

Correlation between model observer and human observer performance in CT imaging when lesion location is uncertain

Energy Technology Data Exchange (ETDEWEB)

Leng, Shuai; Yu, Lifeng; Zhang, Yi; McCollough, Cynthia H. [Department of Radiology, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States); Carter, Rickey [Department of Biostatistics, Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota 55905 (United States); Toledano, Alicia Y. [Biostatistics Consulting, LLC, 10606 Wheatley Street, Kensington, Maryland 20895 (United States)

2013-08-15

Purpose: The purpose of this study was to investigate the correlation between model observer and human observer performance in CT imaging for the task of lesion detection and localization when the lesion location is uncertain.Methods: Two cylindrical rods (3-mm and 5-mm diameters) were placed in a 35 × 26 cm torso-shaped water phantom to simulate lesions with −15 HU contrast at 120 kV. The phantom was scanned 100 times on a 128-slice CT scanner at each of four dose levels (CTDIvol = 5.7, 11.4, 17.1, and 22.8 mGy). Regions of interest (ROIs) around each lesion were extracted to generate images with signal-present, with each ROI containing 128 × 128 pixels. Corresponding ROIs of signal-absent images were generated from images without lesion mimicking rods. The location of the lesion (rod) in each ROI was randomly distributed by moving the ROIs around each lesion. Human observer studies were performed by having three trained observers identify the presence or absence of lesions, indicating the lesion location in each image and scoring confidence for the detection task on a 6-point scale. The same image data were analyzed using a channelized Hotelling model observer (CHO) with Gabor channels. Internal noise was added to the decision variables for the model observer study. Area under the curve (AUC) of ROC and localization ROC (LROC) curves were calculated using a nonparametric approach. The Spearman's rank order correlation between the average performance of the human observers and the model observer performance was calculated for the AUC of both ROC and LROC curves for both the 3- and 5-mm diameter lesions.Results: In both ROC and LROC analyses, AUC values for the model observer agreed well with the average values across the three human observers. The Spearman's rank order correlation values for both ROC and LROC analyses for both the 3- and 5-mm diameter lesions were all 1.0, indicating perfect rank ordering agreement of the figures of merit (AUC

Background based Gaussian mixture model lesion segmentation in PET

Energy Technology Data Exchange (ETDEWEB)

Soffientini, Chiara Dolores, E-mail: chiaradolores.soffientini@polimi.it; Baselli, Giuseppe [DEIB, Department of Electronics, Information, and Bioengineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milan 20133 (Italy); De Bernardi, Elisabetta [Department of Medicine and Surgery, Tecnomed Foundation, University of Milano—Bicocca, Monza 20900 (Italy); Zito, Felicia; Castellani, Massimo [Nuclear Medicine Department, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, via Francesco Sforza 35, Milan 20122 (Italy)

2016-05-15

Purpose: Quantitative {sup 18}F-fluorodeoxyglucose positron emission tomography is limited by the uncertainty in lesion delineation due to poor SNR, low resolution, and partial volume effects, subsequently impacting oncological assessment, treatment planning, and follow-up. The present work develops and validates a segmentation algorithm based on statistical clustering. The introduction of constraints based on background features and contiguity priors is expected to improve robustness vs clinical image characteristics such as lesion dimension, noise, and contrast level. Methods: An eight-class Gaussian mixture model (GMM) clustering algorithm was modified by constraining the mean and variance parameters of four background classes according to the previous analysis of a lesion-free background volume of interest (background modeling). Hence, expectation maximization operated only on the four classes dedicated to lesion detection. To favor the segmentation of connected objects, a further variant was introduced by inserting priors relevant to the classification of neighbors. The algorithm was applied to simulated datasets and acquired phantom data. Feasibility and robustness toward initialization were assessed on a clinical dataset manually contoured by two expert clinicians. Comparisons were performed with respect to a standard eight-class GMM algorithm and to four different state-of-the-art methods in terms of volume error (VE), Dice index, classification error (CE), and Hausdorff distance (HD). Results: The proposed GMM segmentation with background modeling outperformed standard GMM and all the other tested methods. Medians of accuracy indexes were VE <3%, Dice >0.88, CE <0.25, and HD <1.2 in simulations; VE <23%, Dice >0.74, CE <0.43, and HD <1.77 in phantom data. Robustness toward image statistic changes (±15%) was shown by the low index changes: <26% for VE, <17% for Dice, and <15% for CE. Finally, robustness toward the user-dependent volume initialization was

Regeneración de las lesiones críticas del nervio periférico con factores de crecimiento: Estudio experimental

OpenAIRE

García Medrano, Belén

2013-01-01

Introducción:El objetivo del proyecto es estudiar la regeneración de lesiones no reparables de nervio periférico mediante un injerto muscular enriquecido con factores de crecimiento. Material y método: Estudio experimental controlado, nivel I de evidencia cientifica. Comparamos diez ratas con reparación de lesiones de 15 mm del nervio ciático mediante injerto muscular acelular, con un grupo de diez años en los que se añade la inyección de 2 cc de IGF-l (10 mg/ml de me

Experimental Object-Oriented Modelling

DEFF Research Database (Denmark)

Hansen, Klaus Marius

through, e.g., technical prototyping and active user involvement. We introduce and examine “experimental object-oriented modelling” as the intersection of these practices. The contributions of this thesis are expected to be within three perspectives on models and modelling in experimental system...... development: Grounding We develop an empirically based conceptualization of modelling and use of models in system development projects characterized by a high degree of uncertainty in requirements and point to implications for tools and techniques for modelling in such a setting. Techniques We introduce......This thesis examines object-oriented modelling in experimental system development. Object-oriented modelling aims at representing concepts and phenomena of a problem domain in terms of classes and objects. Experimental system development seeks active experimentation in a system development project...

Proangiogenic Tie2(+) macrophages infiltrate human and murine endometriotic lesions and dictate their growth in a mouse model of the disease.

Science.gov (United States)

Capobianco, Annalisa; Monno, Antonella; Cottone, Lucia; Venneri, Mary Anna; Biziato, Daniela; Di Puppo, Francesca; Ferrari, Stefano; De Palma, Michele; Manfredi, Angelo A; Rovere-Querini, Patrizia

2011-11-01

Endometriosis affects women of reproductive age, causing infertility and pain. Although immune cells are recruited in endometriotic lesions, their role is unclear. Tie2-expressing macrophages (TEMs) have nonredundant functions in promoting angiogenesis and growth of experimental tumors. Here we show that human TEMs infiltrate areas surrounding newly formed endometriotic blood vessels. We set up an ad hoc mouse model in which TEMs, and not Tie2-expressing endothelial cells, are targeted. We transplanted in wild-type recipients bone marrow cells expressing a suicide gene (Herpes simplex virus type 1 thymidine kinase) under the Tie2 promoter/enhancer. TEMs infiltrated endometriotic lesions. TEM depletion by ganciclovir administration arrested the growth of established lesions, without toxicity. Lesion architecture was disrupted, with: i) loss of glandular organization, ii) reduced neovascularization, and iii) activation of caspase 3 in CD31(+) endothelial cells. Thus, TEMs are important for maintaining the viability of newly formed vessels and represent a potential therapeutic target in endometriosis. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

A model to environmental monitoring based on glutathione-S-transferase activity and branchial lesions in catfish

Science.gov (United States)

Neta, Raimunda Nonata Fortes Carvalho; Torres, Audalio Rebelo

2017-11-01

In this work, we validate the glutathione-S-transferase and branchial lesions as biomarkers in catfish Sciades herzbergii to obtain a predictive model of the environmental impact effects in a harbor of Brazil. The catfish were sampled from a port known to be contaminated with heavy metals and organic compounds and from a natural reserve in São Marcos Bay, Maranhão. Two biomarkers, hepatic glutathione S-transferase (GST) activity and branchial lesions were analyzed. The values for GST activity were modeled with the occurrence of branchial lesions by fitting a third order polynomial. Results from the mathematical model indicate that GST activity has a strong polynomial relationship with the occurrence of branchial lesions in both the wet and the dry seasons, but only at the polluted port site. Our mathematic model indicates that when the GST ceases to act, serious branchial lesions are observed in the catfish of the contaminated port area.

SCREENING OF WILD FRUIT TREES WITH GASTROPROTECTIVE ACTIVITY IN DIFFERENT EXPERIMENTAL MODELS.

Science.gov (United States)

Nesello, Luciane Angela Nottar; Campos, Adriana; Rosa, Roseane Leandra da; Andrade, Sérgio Faloni de; Cechinel, Valdir

2017-01-01

Given the increase of people with gastrointestinal disorders, the search for alternative treatments with fewer side effects is vital, as well as the demand for food or plants that can help protect the stomach. The aim of this study was to evaluate the gastroprotective action of the extracts of wild fruit trees of Myrcianthes pungens (guabiju); Inga vera Willd. (ingá-banana) and Marlierea tomentosa Cambess. (guarapuruna) in in vivo pharmacological models. The different parts of the fruits were separately subjected to a process of extraction by methanol. Two experimental pharmacological models were conducted in mice; the gastric ulcer model induced by non-steroidal anti-inflammatory (indomethacin), and the gastric ulcer model induced by ethanol/HCl, which allowed us to evaluate the gastroprotective activity of the extracts at a dose of 250 mg/kg. Subsequently, the total lesion area (mm2) and relative lesion area (%) were determined. The results showed significant gastroprotective activity against the aggressive agents used - ethanol and indomethacin - for all the extracts tested. It is assumed that the fruits have bioactive compounds such as antioxidant substances that act on the prostaglandin levels, protecting them from the damage caused by ethanol and indomethacin. These results prompt further studies to isolate and identify the active properties.

A Generative Probabilistic Model and Discriminative Extensions for Brain Lesion Segmentation - With Application to Tumor and Stroke

DEFF Research Database (Denmark)

Menze, Bjoern H.; Van Leemput, Koen; Lashkari, Danial

2016-01-01

jointly from the image data. It delineates lesion areas individually in each channel, allowing for differences in lesion appearance across modalities, an important feature of many brain tumor imaging sequences. We also propose discriminative model extensions to map the output of the generative model......), to estimate the label map for a new image. Our model augments the probabilistic atlas of the healthy tissues with a latent atlas of the lesion. We derive an estimation algorithm with closed-form EM update equations. The method extracts a latent atlas prior distribution and the lesion posterior distributions...

Impact of cavitation on lesion formation induced by high intensity focused ultrasound

International Nuclear Information System (INIS)

Fan Pengfei; Jie Yu; Yang Xin; Tu Juan; Guo Xiasheng; Zhang Dong; Huang Pintong

2017-01-01

High intensity focused ultrasound (HIFU) has shown a great promise in noninvasive cancer therapy. The impact of acoustic cavitation on the lesion formation induced by HIFU is investigated both experimentally and theoretically in transparent protein-containing gel and ex vivo liver tissue samples. A numerical model that accounts for nonlinear acoustic propagation and heat transfer is used to simulate the lesion formation induced by the thermal effect. The results showed that lesions could be induced in the samples exposed to HIFU with various acoustic pressures and pulse lengths. The measured areas of lesions formed in the lateral direction were comparable to the simulated results, while much larger discrepancy was observed between the experimental and simulated data for the areas of longitudinal lesion cross-section. Meanwhile, a series of stripe-wiped-off B-mode pictures were obtained by using a special imaging processing method so that HIFU-induced cavitation bubble activities could be monitored in real-time and quantitatively analyzed as the functions of acoustic pressure and pulse length. The results indicated that, unlike the lateral area of HIFU-induced lesion that was less affected by the cavitation activity, the longitudinal cross-section of HIFU-induced lesion was significantly influenced by the generation of cavitation bubbles through the temperature elevation resulting from HIFU exposures. Therefore, considering the clinical safety in HIFU treatments, more attention should be paid on the lesion formation in the longitudinal direction to avoid uncontrollable variation resulting from HIFU-induced cavitation activity. (paper)

Cylindrical SUV distribution model for detecting skin lesions in body trunk FDG-PET/CT images

International Nuclear Information System (INIS)

Nemoto, Mitsutaka; Nomura, Yukihiro; Masutani, Yoshitaka; Yoshikawa, Takeharu; Hayashi, Naoto; Yoshioka, Naoki; Ohtomo, Kuni; Hanaoka, Shouhei

2010-01-01

We have been developing a computerized detection method for skin lesions in body trunk fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT images. Spots on the skin with a high standard uptake value (SUV) are due not only to glucose metabolism in skin lesions but also to the physiological metabolism of organs near the skin. The distribution pattern of regional SUV on the skin is important information for the differential diagnosis of such high-SUV spots. In this study, we have developed a new skin lesion detection method based on a cylindrical SUV distribution model of the skin. The shape of the SUV distribution model is an approximation of the body trunk, and the SUV distribution model includes standard values for regional skin SUV. Classifier ensembles based on CT image features, SUV features, and subtraction features between the SUVs in FDG-PET images and the values in the SUV distribution model are used to extract and classify candidate regions for skin lesions. In a study of skin lesion detection using FDG-PET/CT images in 36 clinical cases, the true-positive rate was 61.7%, with 11.7 false-positive regions per case. The training results of the classifier ensemble for extracting and classifying candidate regions showed the effective features for detecting skin lesions in the study. (author)

Thermophysical lesions caused by HZE particles

International Nuclear Information System (INIS)

Tobias, C.A.; Malachowski, M.; Nelson, A.; Philpott, D.E.

1980-01-01

This paper deals with a type of damage caused by heavy particles that may occur in subcellular structures. These lesions are called thermophysical radiation injury and are similar to damage produced in solids by HZE particles. This chapter summarizes some of the experimental evidence for the presence of these lesions in certain mammalian tissues including the retina, brain, cornea, lens of mice and seeds of corn. Of all tissues examined, only the cornea exhibited a type of lesion which would fulfill the criteria of thermophysical lesions

Experimental approbation of a new ultrosound contrast agent based on sulfur geksafluoride in diagnostics of focal liver lesions of inflammatory genesis

Directory of Open Access Journals (Sweden)

S. V. Fomina

2017-01-01

Full Text Available Purpose of the study. Experimental approbation of a new domestic ultrasound contrast agent (UCA based on sulfur hexafluoride in the diagnosis of focal liver lesions of inflammatory genesis.Materials and methods. The investigated ultrasound contrast agent (UCA was a heterogeneous gas-liquid system consisting of micro bubbles of a sparingly soluble gas of sulfur hexafluoride (SF6 surrounded by a flexible mobile membrane of surfactants. Experimental work was carried out on rabbits. The study group included rabbits of males and females with focal liver lesion of inflammatory genesis (n = 12 weighing 1500- 1700 g. UCA was administered to animals in the ear vein. Focal lesions of the liver in animals were created in the experimental laboratory conditions. 14 days after the operation, all animals were subjected to ultrasound examination of the surgical intervention zones by using the Toshiba Aplio 400 scanners (Japan with a 3,5–8 MHz convection sensor. In a natural study, the size, structure and echogenicity of the focus were assessed, the degree of vascularization, the evenness and clarity of the contours were determined. When performing post contrast ultrasound, the time of the onset of contrast enhancement, the total duration of contrast, the changes in the contrast enhancement of the focus in different phases of the study were measured, the dimensions of the focus were measured, and the evenness and acuity of contours were measured. For histological examination, liver fragments and lungs were used. 

Analysis of the effects of exposure to acute hypoxia on oxidative lesions and tumour progression in a transgenic mouse breast cancer model

Directory of Open Access Journals (Sweden)

Lunt Sarah

2008-05-01

Full Text Available Abstract Background Tumour hypoxia is known to be a poor prognostic indicator, predictive of increased risk of metastatic disease and reduced survival. Genomic instability has been proposed as one of the potential mechanisms for hypoxic tumour progression. Both of these features are commonly found in many cancer types, but their relationship and association with tumour progression has not been examined in the same model. Methods To address this issue, we determined the effects of 6 week in vivo acute hypoxic exposure on the levels of mutagenic lipid peroxidation product, malondialdehyde, and 8-oxo-7,8-dihydro-2'-deoxyguanosine DNA (8-oxo-dG lesions in the transgenic polyomavirus middle T (PyMT breast cancer mouse model. Results We observed significantly increased plasma lipid peroxidation and 8-oxo-dG lesion levels in the hypoxia-exposed mice. Consumption of malondialdehyde also induced a significant increase in the PyMT tumour DNA lesion levels, however, these increases did not translate into enhanced tumour progression. We further showed that the in vivo exposure to acute hypoxia induced accumulation of F4/80 positive tumour-associated macrophages (TAMs, demonstrating a relationship between hypoxia and macrophages in an experimental model. Conclusion These data suggest that although exposure to acute hypoxia causes an increase in 8-oxo-dG lesions and TAMs in the PyMT tumours, these increases do not translate into significant changes in tumour progression at the primary or metastatic levels in this strong viral oncogene-driven breast cancer model.

detecting multiple sclerosis lesions with a fully bioinspired visual attention model

Science.gov (United States)

Villalon-Reina, Julio; Gutierrez-Carvajal, Ricardo; Thompson, Paul M.; Romero-Castro, Eduardo

2013-11-01

The detection, segmentation and quantification of multiple sclerosis (MS) lesions on magnetic resonance images (MRI) has been a very active field for the last two decades because of the urge to correlate these measures with the effectiveness of pharmacological treatment. A myriad of methods has been developed and most of these are non specific for the type of lesions and segment the lesions in their acute and chronic phases together. On the other hand, radiologists are able to distinguish between several stages of the disease on different types of MRI images. The main motivation of the work presented here is to computationally emulate the visual perception of the radiologist by using modeling principles of the neuronal centers along the visual system. By using this approach we are able to detect the lesions in the majority of the images in our population sample. This type of approach also allows us to study and improve the analysis of brain networks by introducing a priori information.

Kinetic modeling of low density lipoprotein oxidation in arterial wall and its application in atherosclerotic lesions prediction.

Science.gov (United States)

Karimi, Safoora; Dadvar, Mitra; Modarress, Hamid; Dabir, Bahram

2013-01-01

Oxidation of low-density lipoprotein (LDL) is one of the major factors in atherogenic process. Trapped oxidized LDL (Ox-LDL) in the subendothelial matrix is taken up by macrophage and leads to foam cell generation creating the first step in atherosclerosis development. Many researchers have studied LDL oxidation using in vitro cell-induced LDL oxidation model. The present study provides a kinetic model for LDL oxidation in intima layer that can be used in modeling of atherosclerotic lesions development. This is accomplished by considering lipid peroxidation kinetic in LDL through a system of elementary reactions. In comparison, characteristics of our proposed kinetic model are consistent with the results of previous experimental models from other researches. Furthermore, our proposed LDL oxidation model is added to the mass transfer equation in order to predict the LDL concentration distribution in intima layer which is usually difficult to measure experimentally. According to the results, LDL oxidation kinetic constant is an important parameter that affects LDL concentration in intima layer so that existence of antioxidants that is responsible for the reduction of initiating rates and prevention of radical formations, have increased the concentration of LDL in intima by reducing the LDL oxidation rate. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Dosimetric analysis of radiation sources for use dermatological lesions

International Nuclear Information System (INIS)

Tada, Ariane

2010-01-01

Skin lesions undergoing therapy with radiation sources may have different patterns of malignancy. Malignant lesions or cancer most commonly found in radiotherapy services are carcinomas. Radiation therapy in skin lesions is performed with low penetration beams and orthovoltage X-rays, electron beams and radioactive sources ( 192 Ir, 198 Au, e 90 Sr) arranged on a surface mold or in metal applicator. This study aims to analyze the therapeutic radiation dose profile produced by radiation sources used in skin lesions radiotherapy procedures . Experimental measurements for the analysis of dosimetric radiation sources were compared with calculations obtained from a computer system based on the Monte Carlo Method. Computational results had a good agreement with the experimental measurements. Experimental measurements and computational results by the MCNP4C code were both physically consistent as expected. These experimental measurements compared with calculations using the MCNP-4C code have been used to validate the calculations obtained by MCNP code and to provide a reliable medical application for each clinical case. (author)

Oral Administration of Pentoxifylline Reduces Endometriosis-Like Lesions in a Nude Mouse Model.

Science.gov (United States)

Perelló, Maria; González-Foruria, Iñaki; Castillo, Paola; Martínez-Florensa, Mario; Lozano, Francisco; Balasch, Juan; Carmona, Francisco

2017-06-01

Recent reports consider endometriosis to be an immunological disorder, thus suggesting potential efficacy of immunomodulators for its treatment. The aim of this study was to assess the effects of oral administration of pentoxifylline on endometriosis-like lesions in a heterologous mice model. Human endometrial tissue obtained from women (n = 5) undergoing surgery for benign conditions was implanted in nude female mice (n = 30). The animals were distributed into 3 experimental groups receiving: saline 0.1 mL/d (control, group 1); pentoxifylline 100 mg/kg/d (group 2), and pentoxifylline 200 mg/kg/d (group 3). After 28 days, the number of implants and the total volume of surgically extracted tissue were recorded. Immunohistochemical analysis was performed to assess the area of endometriosis and vascularization of endometriosis-like lesions. Cytokine levels in peritoneal fluid samples were measured. Macroscopic quantification showed a trend to dose-dependent reduction in the number of the endometriosis-like lesions after 28 days. The volume was significantly reduced in group 3 versus group 2 and controls (399.10 ± 120.68 mm 3 vs 276.75 ± 94.30 mm 3 and 145.33 ± 38.20 mm 3 , respectively; P = .04). Similarly, the mean area of endometriosis was significantly lower in group 3 (0.12 ± 0.08 mm 2 ) versus group 2 (1.35 ± 0.43 mm 2 ) and control (2.84 ± 0.60 mm 2 ; P = .001). Vascularization and cytokine levels were also reduced posttreatment. Our results suggest that the oral administration of pentoxifylline may be an alternative to current therapies for endometriosis. Nonetheless, further studies are required.

Experimental rickets in broilers: gross, microscopic, and radiographic lesions. II. Calcium deficiency

International Nuclear Information System (INIS)

Long, P.H.; Lee, S.R.; Rowland, G.N.; Britton, W.M.

1984-01-01

Day-old broiler chicks were fed a calcium-deficient diet for 30 days. Gross, microscopic, and radiographic examinations of the proximal tibiotarsus were done at 2, 3, and 4 weeks of age. In 2-week-old chicks, the growth-plate proliferating-prehypertrophied zone (P-PHZ) was variably lengthened and disorganized, cartilage columns of the degenerating hypertrophied zone and metaphyseal primary spongiosa were shortened, and bone spicules of the secondary spongiosa were bordered by increased osteoid. In 3-week-old chicks, lesions were either similar or more pronounced, with the additional finding of metaphyseal peritrabecular fibrosis. In 4-week-old chicks, the P-PHZ decreased in relative length, osteoid seams and fibrous connective tissue were less prominent, and tibial dyschondroplasia-like lesions were present. Results demonstrated that dietary calcium deficiency produced rachitic lesions, that the lesions were very different from those of phosphorus deficiency or calcium excess, and that the lesions were variable over time. (author)

Post-radiotherapeutic heart lesions

International Nuclear Information System (INIS)

Testart, F.M.

1979-05-01

Heart structures have traditionally been considered radioresistant. In fact all tissues subjected to radiotherapy can develop lesions. Possible damage includes: - pericardiac fibrosis, the commonest and best individualized, associated with a constriction this leads to a stoppage pattern usually occurring late, around the 18th month. Its frequency depends directly on the total radiation dose; - fibrous myocarditis by direct damage to the heart muscle; - stenosis type lesions of the large coronary trunks; - in exceptional cases lesions of the aorta: hyperplastic degenerescence of the intima and adventitia or of the aortic sigmoid valvules and the mitral valves. Three observations are reported, concerning a coronary, a pericardiac and a coronary, myocardiac and pericardiac lesion. Following this account the irradiation techniques and main experimental data are reviewed and the prophylactic and therapeutic consequences to be derived from our observations and those of the literature are examined [fr

Effects of gypenosides on anxiety disorders in MPTP-lesioned mouse model of Parkinson's disease.

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Shin, Keon Sung; Zhao, Ting Ting; Choi, Hyun Sook; Hwang, Bang Yeon; Lee, Chong Kil; Lee, Myung Koo

2014-06-03

Ethanol extract (GP-EX) of Gynostemma pentaphyllum (GP) ameliorates chronic stress-induced anxiety in mice. The present study investigated the effects of gypenoside-enriched components (GPS), GP-EX and water extract of GP (GP-WX) on MPTP lesion-induced affective disorders in C57BL/6 mice. GPS (50mg/kg) and GP-EX (50mg/kg) for 21 day-treatment period improved the symptom of anxiety disorders in the MPTP-lesioned mouse model of PD with or without L-DOPA treatment, which was examined by the elevated plus-maze and marble burying tests. In these states, treatments with GPS (50mg/kg) and GP-EX (50mg/kg) significantly increased the brain levels of dopamine and serotonin in the MPTP-lesioned mouse model of PD with or without l-DOPA treatment. In addition, treatments with GPS (50mg/kg) and GP-EX (50mg/kg) showed protective effects on dopaminergic neurons in MPTP-lesioned mouse model of PD with or without L-DOPA treatment. In contrast, GPS (30 mg/kg) and GP-WX (50mg/kg) showed anxiolytic effects in the same animal models, but it was not significant. These results suggest that GPS (50mg/kg) and GP-EX (50mg/kg) showed anxiolytic effects on affective disorders and protective effects on dopaminergic neurons by modulating the brain levels of dopamine and serotonin in the MPTP-lesioned mouse model of PD with or without l-DOPA treatment. Clinical trials of GPS and GP-EX need to be conducted further so as to develop adjuvant therapeutic agents for PD patients. Copyright © 2014 Elsevier B.V. All rights reserved.

Radiation-induced hydronephrosis in the rat: a new experimental model

International Nuclear Information System (INIS)

Knowles, J.F.

1985-01-01

An experimental model for investigating the effects of localized X-irradiation on a single ureter or the bladder trigone in rats is described. Obstruction of the urinary tract in the irradiated region gives rise to hydroureter and hydronephrosis and the development of these, as detected urographically, gives a clear-cut end point. After irradiation of the ureter with a single dose of 37.4 gy many rats died of gut lesions but after 23.4 Gy only one such death occurred while 14 of 16 rats developed hydronephrosis. Irradiation of the bladder trigone was not associated with intercurrent deaths, even after 40 Gy, and after 25 Gy 9 of 11 rats developed hydronephrosis. (author)

Experimental Oral Candidiasis in Animal Models

Science.gov (United States)

Samaranayake, Yuthika H.; Samaranayake, Lakshman P.

2001-01-01

Oral candidiasis is as much the final outcome of the vulnerability of the host as of the virulence of the invading organism. We review here the extensive literature on animal experiments mainly appertaining to the host predisposing factors that initiate and perpetuate these infections. The monkey, rat, and mouse are the choice models for investigating oral candidiasis, but comparisons between the same or different models appear difficult, because of variables such as the study design, the number of animals used, their diet, the differences in Candida strains, and the duration of the studies. These variables notwithstanding, the following could be concluded. (i) The primate model is ideal for investigating Candida-associated denture stomatitis since both erythematous and pseudomembranous lesions have been produced in monkeys with prosthetic plates; they are, however, expensive and difficult to obtain and maintain. (ii) The rat model (both Sprague-Dawley and Wistar) is well proven for observing chronic oral candidal colonization and infection, due to the ease of breeding and handling and their ready availability. (iii) Mice are similar, but in addition there are well characterized variants simulating immunologic and genetic abnormalities (e.g., athymic, euthymic, murine-acquired immune deficiency syndrome, and severe combined immunodeficient models) and hence are used for short-term studies relating the host immune response and oral candidiasis. Nonetheless, an ideal, relatively inexpensive model representative of the human oral environment in ecological and microbiological terms is yet to be described. Until such a model is developed, researchers should pay attention to standardization of the experimental protocols described here to obtain broadly comparable and meaningful data. PMID:11292645

Local CD34-positive capillaries decrease in mouse models of kidney disease associating with the severity of glomerular and tubulointerstitial lesions.

Science.gov (United States)

Masum, Md Abdul; Ichii, Osamu; Elewa, Yaser Hosny Ali; Nakamura, Teppei; Kon, Yasuhiro

2017-09-04

The renal vasculature plays important roles in both homeostasis and pathology. In this study, we examined pathological changes in the renal microvascular in mouse models of kidney diseases. Glomerular lesions (GLs) in autoimmune disease-prone male BXSB/MpJ-Yaa (Yaa) mice and tubulointerstitial lesions (TILs) in male C57BL/6 mice subjected to unilateral ureteral obstruction (UUO) for 7 days were studied. Collected kidneys were examined using histopathological techniques. A nonparametric Mann-Whitney U test (P < 0.05) was performed to compare healthy controls and the experimental mice. The Kruskal-Wallis test was used to compare three or more groups, and multiple comparisons were performed using Scheffe's method when significant differences were observed (P < 0.05). Yaa mice developed severe autoimmune glomerulonephritis, and the number of CD34 + glomerular capillaries decreased significantly in GLs compared to that in control mice. However, UUO-treated mice showed severe TILs only, and CD34 + tubulointerstitial capillaries were decreased significantly in TILs with the progression of tubulointerstitial fibrosis compared to those in untreated control kidneys. Infiltrations of B-cells, T-cells, and macrophages increased significantly in the respective lesions of both disease models (P < 0.05). In observations of vascular corrosion casts by scanning electron microscopy and of microfil rubber-perfused thick kidney sections by fluorescence microscopy, segmental absences of capillaries were observed in the GLs and TILs of Yaa and UUO-treated mice, respectively. Further, transmission electron microscopy revealed capillary endothelial injury in the respective lesions of both models. The numbers of CD34 + glomerular and tubulointerstitial capillaries were negatively correlated with all examined parameters in GLs (P < 0.05) and TILs (P < 0.01), respectively. From the analysis of mouse models, we identified inverse pathological correlations between the number of

The effect of steroid on FDG uptake in experimental tumors, granulomatous and inflammatory lesions

International Nuclear Information System (INIS)

Zhao Songji; Yuji Kuge; Kunihiro Nakada; Masayuki Sato; Toshiki Takei; Zhao Yan; Nagara Tamaki; Masashi Kohanawa; Ken-ichi Seki

2004-01-01

Objectives: FDG accumulates not only in malignant tumors but also inflammatory lesions, especially in granulomatous lesions, which makes differentiate malignant tumors from benign lesions difficult. To obtain a clue for differentiating malignant lesions from benign ones by FDG-PET, we determined the effect of steroid on FDG uptake in granulomatous and inflammatory lesions, and compared them with those in malignant tumors in rats. Methods: Rats were inoculated with a suspension of allogenic hepatoma cells (KDH-8), Bacille bili e de Calmette-Guerin-(BCG) or Staphylococcus aureus (S. aureus), or with turpentine oil into the left calf muscle. Two weeks after KDH-8, 19 days after BCG, or one week after S. aureus or turpentine oil inoculations, the rats were fasted overnight and divided into two subgroups (n=5-6, in each group): Prednisolone (PRE)-pretreated (Methylprednisolone acetate, 8 mg/kg body weight, i.m. injection 20 hour before the FDG intravenous injection) and control (untreated) groups. Radioactivity in tissues was determined one hour after i.v. injection of FDG. FDG uptake in tissues were expressed as the percentage of injected dose per gram of tissue after normalization to animal's weight (%ID/g tissue/kg body weight). Results: FDG uptake in the tumor, granulomatous and inflammatory lesions were shown in Table. In the untreated animals, remarkably higher accumulations of FDG were observed in the tumor and granulomatous lesions, compared with those in the inflammatory lesions induced by S. aureus and turpentine oil. There was no significant difference in the level of FDG uptake between the tumor and granulomatous lesions, and between the two inflammatory lesions. PRE pre-treatment significantly decreased the level of FDG uptake in granulomatous lesions induced by BCG, inflammatory lesions induced by S. aureus and turpentine oil to 52%, 73% and 76% of the control value, respectively. The level of FDG uptake in the tumor was not significantly decreased by PRE

Simvastatin prevents dopaminergic neurodegeneration in experimental parkinsonian models: the association with anti-inflammatory responses.

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Junqiang Yan

Full Text Available BACKGROUND: In addition to their original applications to lowering cholesterol, statins display multiple neuroprotective effects. N-methyl-D-aspartate (NMDA receptors interact closely with the dopaminergic system and are strongly implicated in therapeutic paradigms of Parkinson's disease (PD. This study aims to investigate how simvastatin impacts on experimental parkinsonian models via regulating NMDA receptors. METHODOLOGY/PRINCIPAL FINDINGS: Regional changes in NMDA receptors in the rat brain and anxiolytic-like activity were examined after unilateral medial forebrain bundle lesion by 6-hydroxydopamine via a 3-week administration of simvastatin. NMDA receptor alterations in the post-mortem rat brain were detected by [³H]MK-801(Dizocilpine binding autoradiography. 6-hydroxydopamine treated PC12 was applied to investigate the neuroprotection of simvastatin, the association with NMDA receptors, and the anti-inflammation. 6-hydroxydopamine induced anxiety and the downregulation of NMDA receptors in the hippocampus, CA1(Cornu Ammonis 1 Area, amygdala and caudate putamen was observed in 6-OHDA(6-hydroxydopamine lesioned rats whereas simvastatin significantly ameliorated the anxiety-like activity and restored the expression of NMDA receptors in examined brain regions. Significant positive correlations were identified between anxiolytic-like activity and the restoration of expression of NMDA receptors in the hippocampus, amygdala and CA1 following simvastatin administration. Simvastatin exerted neuroprotection in 6-hydroxydopamine-lesioned rat brain and 6-hydroxydopamine treated PC12, partially by regulating NMDA receptors, MMP9 (matrix metalloproteinase-9, and TNF-a (tumour necrosis factor-alpha. CONCLUSIONS/SIGNIFICANCE: Our results provide strong evidence that NMDA receptor modulation after simvastatin treatment could partially explain its anxiolytic-like activity and anti-inflammatory mechanisms in experimental parkinsonian models. These findings

Effect of Pre-nutrion of Flax Seed Oil (Linum Usitatissimum on the amount of Cerebral ischemic lesion and motor nerve disorders in animal model rat.

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SV Hosseini

2015-10-01

Full Text Available Background & aim: Stroke is the third death agent (factor in industrial countries after cardiovascular disease and cancer. With regard to high content of antioxidant materials in flax seed oil like &alpha-linolenic acid, lignan as well as phenolic combinations like secoisolarisirsinol (SDG, this study performed for studding relationship between of cerebral ischemic lesion and motor-nerve disorders in model of stroke in rat. Methods: in the study, 35 male mice from strain Wistar divided to 5 groups. The groups included control, sham and 3 experimental groups. They received doses 0.25, 0.5 and 0.75 ml/kg from flax seed oil orally. By gavage for 30 days two control and sham groups received aqua distillate (distil water. Two hours after the last gavaged dose, overly group with 7 pieces operated for measurement of the amount of cerebral lesion and motor-nerve disorders. (Middle Cerebral Artery Occlusion Model. Middle cerebral Artery Occlusion by the model resulted in local ischemic stroke in animal. Data analyzed by software SPSS, test ANOVA and disorders by test mann-Whitney. Findings: Average of records of motor-nerve disorders decreased significantly in group with dose 0.5 and 0.75 using flax seed oil (P<0.05. The amount of cerebral ischemic lesion in doses 0.5 and 0.75 than to control group is indicated meaning full different, but percent of the total cerebral lesion in control group in compared group with dose 0.25 is not indicated meaningful different. Percent of the amount of ischemic lesion in region penumbra in group 0.75 and 0.5 than to control group is indicated meaningful different, but percent of the amount of lesion in region penumbra in control group in compared region penumbra in group with dose 0.25 is not indicated meaning full different. Results: Findings of the study indicated that flax seed oil, particular in doses 0.5 and 0.75 resulted to decrease of the amount of cerebral ischemic lesion and decrease of motor-nerve disorders in

Quantitative 2- and 3-dimensional analysis of pharmacokinetic model-derived variables for breast lesions in dynamic, contrast-enhanced MR mammography

International Nuclear Information System (INIS)

Hauth, E.A.M.; Jaeger, H.J.; Maderwald, S.; Muehler, A.; Kimmig, R.; Forsting, M.

2008-01-01

Purpose: 2- and 3-dimensional evaluation of quantitative pharmacokinetic parameters derived from the Tofts model modeling dynamic contrast enhancement of lesions in MR mammography. Materials and methods: In 95 patients, MR mammography revealed 127 suspicious lesions. The initial rate of enhancement was coded by color intensity, the post-initial enhancement change is coded by color hue. 2D and 3D analysis of distribution of color hue and intensity, vascular permeability and extracellular volume were performed. Results: In 2D, malignant lesions showed significant higher number of bright red, medium red, dark red, bright green, medium green, dark green and bright blue pixels than benign lesions. In 3D, statistical significant differences between malignant and benign lesions was found for all this parameters. Vascular permeability was significant higher in malignant lesions than in benign lesions. Regression model using the 3D data found that the best discriminator between malignant and benign lesions was combined number of voxels and medium green pixels, with a sensitivity of 79.4% and a specificity of 83.1%. Conclusions: Quantitative analysis of pharmacokinetic variables of contrast kinetics showed significant differences between malignant and benign lesions. 3D analysis showed superior diagnostic differentiation between malignant and benign lesions than 2D analysis. The parametric analysis using a pharmacokinetic model allows objective analysis of contrast enhancement in breast lesions

Is the repair of articular cartilage lesion by costal chondrocyte transplantation donor age-dependent? An experimental study in rabbits.

Directory of Open Access Journals (Sweden)

Janusz Popko

2006-09-01

Full Text Available The repair of chondral injuries is a very important problem and a subject of many experimental and clinical studies. Different techniques to induce articular cartilage repair are under investigation. In the present study, we have investigated whether the repair of articular cartilage folowing costal chondrocyte transplantation is donor age-dependent. Transplantation of costal chondrocytes from 4- and 24-week old donors, with artificially induced femoral cartilage lesion, was performed on fourteen 20-week-old New Zealand White male rabbits. In the control group, the lesion was left without chondrocyte transplantation. The evaluation of the cartilage repair was performed after 12 weeks of transplantation. We analyzed the macroscopic and histological appearance of the newly formed tissue. Immunohistochemistry was also performed using monoclonal antibodies against rabbit collagen type II. The newly formed tissue had a hyaline-like appearance in most of the lesions after chondrocyte transplantation. Positive immunohistochemical reaction for collagen II was also observed in both groups with transplanted chondrocytes. Cartilage from adult donors required longer isolation time and induced slightly poorer repair. However, hyaline-like cartilage was observed in most specimens from this group, in contrast to the control group, where fibrous connective tissue filled the lesions. Rabbit costal chondrocytes seem to be a potentially useful material for inducing articular cartilage repair and, even more important, they can also be derived from adult, sexually mature animals.

Is the Watanabe heritable hyperlipidemic rabbit a suitable experimental model for percutaneous transluminal coronary angioplasty in humans? A light microscopic, immunohistochemical and ultrastructural study

NARCIS (Netherlands)

Wanibuchi, H.; Dingemans, K. P.; Becker, A. E.; Ueda, M.; Naruko, T.; Tanizawa, S.; Nakamura, K.

1993-01-01

This study was designed to assess an experimental model for the study of mechanisms that underlie restenosis after percutaneous transluminal coronary angioplasty. The Watanabe heritable hyperlipidemic (WHHL) rabbit lacks the receptor for low density lipoproteins, produces atherosclerotic lesions

A new background distribution-based active contour model for three-dimensional lesion segmentation in breast DCE-MRI

Energy Technology Data Exchange (ETDEWEB)

Liu, Hui; Liu, Yiping; Qiu, Tianshuang [Department of Biomedical Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao, Zuowei, E-mail: liuhui@dlut.edu.cn [Second Affiliated Hospital, Dalian Medical University, Dalian 116027 (China); Zhang, Lina [Department of Radiology, First Affiliated Hospital, Dalian Medical University, Dalian 116027 (China)

2014-08-15

Purpose: To develop and evaluate a computerized semiautomatic segmentation method for accurate extraction of three-dimensional lesions from dynamic contrast-enhanced magnetic resonance images (DCE-MRIs) of the breast. Methods: The authors propose a new background distribution-based active contour model using level set (BDACMLS) to segment lesions in breast DCE-MRIs. The method starts with manual selection of a region of interest (ROI) that contains the entire lesion in a single slice where the lesion is enhanced. Then the lesion volume from the volume data of interest, which is captured automatically, is separated. The core idea of BDACMLS is a new signed pressure function which is based solely on the intensity distribution combined with pathophysiological basis. To compare the algorithm results, two experienced radiologists delineated all lesions jointly to obtain the ground truth. In addition, results generated by other different methods based on level set (LS) are also compared with the authors’ method. Finally, the performance of the proposed method is evaluated by several region-based metrics such as the overlap ratio. Results: Forty-two studies with 46 lesions that contain 29 benign and 17 malignant lesions are evaluated. The dataset includes various typical pathologies of the breast such as invasive ductal carcinoma, ductal carcinomain situ, scar carcinoma, phyllodes tumor, breast cysts, fibroadenoma, etc. The overlap ratio for BDACMLS with respect to manual segmentation is 79.55% ± 12.60% (mean ± s.d.). Conclusions: A new active contour model method has been developed and shown to successfully segment breast DCE-MRI three-dimensional lesions. The results from this model correspond more closely to manual segmentation, solve the weak-edge-passed problem, and improve the robustness in segmenting different lesions.

Dosimetric analysis of radiation sources to use in dermatological lesions

International Nuclear Information System (INIS)

Tada, Ariane

2010-01-01

Skin lesions undergoing therapy with radiation sources may have different patterns of malignancy. Malignant lesions or cancer most commonly found in radiotherapy services are carcinomas. Radiation therapy in skin lesions is performed with low penetration beams and orthovoltage X-rays, electron beams and radioactive sources ( 192 Ir, 198 Au, e 90 Sr) arranged on a surface mold or in metal applicator. This study aims to analyze the therapeutic radiation dose profile produced by radiation sources used in skin lesions radiotherapy procedures. Experimental measurements for the analysis of dosimetric radiation sources were compared with calculations obtained from a computer system based on the Monte Carlo Method. Computational results had a good agreement with the experimental measurements. Experimental measurements and computational results by the MCNP4C code have been used to validate the calculations obtained by MCNP code and to provide a reliable medical application for each clinical case. (author)

Experimental predictions drawn from a computational model of sign-trackers and goal-trackers.

Science.gov (United States)

Lesaint, Florian; Sigaud, Olivier; Clark, Jeremy J; Flagel, Shelly B; Khamassi, Mehdi

2015-01-01

Gaining a better understanding of the biological mechanisms underlying the individual variation observed in response to rewards and reward cues could help to identify and treat individuals more prone to disorders of impulsive control, such as addiction. Variation in response to reward cues is captured in rats undergoing autoshaping experiments where the appearance of a lever precedes food delivery. Although no response is required for food to be delivered, some rats (goal-trackers) learn to approach and avidly engage the magazine until food delivery, whereas other rats (sign-trackers) come to approach and engage avidly the lever. The impulsive and often maladaptive characteristics of the latter response are reminiscent of addictive behaviour in humans. In a previous article, we developed a computational model accounting for a set of experimental data regarding sign-trackers and goal-trackers. Here we show new simulations of the model to draw experimental predictions that could help further validate or refute the model. In particular, we apply the model to new experimental protocols such as injecting flupentixol locally into the core of the nucleus accumbens rather than systemically, and lesioning of the core of the nucleus accumbens before or after conditioning. In addition, we discuss the possibility of removing the food magazine during the inter-trial interval. The predictions from this revised model will help us better understand the role of different brain regions in the behaviours expressed by sign-trackers and goal-trackers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Porcine skin visible lesion thresholds for near-infrared lasers including modeling at two pulse durations and spot sizes.

Science.gov (United States)

Cain, C P; Polhamus, G D; Roach, W P; Stolarski, D J; Schuster, K J; Stockton, K L; Rockwell, B A; Chen, Bo; Welch, A J

2006-01-01

With the advent of such systems as the airborne laser and advanced tactical laser, high-energy lasers that use 1315-nm wavelengths in the near-infrared band will soon present a new laser safety challenge to armed forces and civilian populations. Experiments in nonhuman primates using this wavelength have demonstrated a range of ocular injuries, including corneal, lenticular, and retinal lesions as a function of pulse duration. American National Standards Institute (ANSI) laser safety standards have traditionally been based on experimental data, and there is scant data for this wavelength. We are reporting minimum visible lesion (MVL) threshold measurements using a porcine skin model for two different pulse durations and spot sizes for this wavelength. We also compare our measurements to results from our model based on the heat transfer equation and rate process equation, together with actual temperature measurements on the skin surface using a high-speed infrared camera. Our MVL-ED50 thresholds for long pulses (350 micros) at 24-h postexposure are measured to be 99 and 83 J cm(-2) for spot sizes of 0.7 and 1.3 mm diam, respectively. Q-switched laser pulses of 50 ns have a lower threshold of 11 J cm(-2) for a 5-mm-diam top-hat laser pulse.

The relative effects of cavitation and nonlinear ultrasound propagation on HIFU lesion dynamics in a tissue phantom

Science.gov (United States)

Khokhlova, Vera A.; Bailey, Michael R.; Reed, Justin; Kaczkowski, Peter J.

2004-05-01

The relative importance of the effects of acoustic nonlinearity and cavitation in HIFU lesion production is studied experimentally and theoretically in a polyacrylamide gel. A 2-MHz transducer of 40-mm diameter and 45-mm focal length was operated at different regimes of power, and in cw or duty-cycle regimes with equal mean intensity. Elevated static pressure was applied to suppress bubbles, increase boiling temperature, and thus to isolate the effect of acoustic nonlinearity in the enhancement of lesion production. Experimental data were compared with the results of simulations performed using a KZK acoustic model combined with the bioheat equation and thermal dose formulation. Boiling and the typical tadpole-shaped lesion shifting towards the transducer were observed under standard atmospheric pressure. No boiling was detected and a symmetric thermal lesion formed in the case of overpressure. A delay in lesion inception time was registered with overpressure, which was hypothesized to be due to suppressed microbubble dynamics. The effect of acoustic nonlinearity was revealed as a substantial decrease in the lesion inception time and an increase in the lesion size for high-amplitude waves under both standard and overpressure conditions. [Work supported by ONRIFO, NASA/NSBRI, NIH Fogarty, and CRDF grants.

Cellular composition of granulomatous lesions in gut-associated lymphoid tissues of goats during the first year after experimental infection with Mycobacterium avium subsp. paratuberculosis.

Science.gov (United States)

Krüger, C; Köhler, H; Liebler-Tenorio, E M

2015-01-15

Mycobacterium avium subsp. paratuberculosis (MAP) causes lesions in naturally and experimentally infected ruminants which greatly differ in severity, cellular composition and number of mycobacteria. Morphologically distinct lesions are already found during the clinically inapparent phase of infection. The complex local host response and number of MAP were characterized at the initial sites of lesions, organized gut-associated lymphoid tissue, in experimentally infected goats. Tissues were collected at 3, 6, 9 and 12 month post-inoculation (mpi) from goat kids that had orally received 10 times 10mg of bacterial wet mass of MAP (JII-1961). The cellular composition of lesions in Peyer's patches in the jejunum and next to the ileocecal valve was evaluated in 21 MAP-inoculated goats, where lesions were compared with unaltered tissue of six control goats. CD68+, CD4+, CD8+, γδ T lymphocytes, B lymphocytes and plasma cells, MHC class II+ and CD25+ cells were demonstrated by immunohistochemistry in serial cryostat sections. At 3 mpi, extensive granulomatous infiltrates predominated, consisting of numerous epitheloid cells admixed with many CD4 and γδ T lymphocytes. Only single MAP were detected. This indicates a strong cellular immune reaction able to control MAP infection. γδ T lymphocytes were markedly increased in this type of lesion which may reflect their important role early in the pathogenesis of paratuberculosis. At 9 and 12 mpi, divergent lesions were observed which may reflect different outcomes of host-pathogen interactions. In five goats, minimal granulomatous lesions were surrounded by extensive lymphoplasmacytic infiltrates and no MAP were detected by immunohistochemistry. This was interpreted as effective host response that was able to eliminate MAP locally. In three goats, decreased numbers of lymphocytes, but extensive granulomatous infiltrates with numerous epitheloid cells containing increased numbers of mycobacteria were seen. This shift of the

Evaluation of the chemical model of vestibular lesions induced by arsanilate in rats

International Nuclear Information System (INIS)

Vignaux, G.; Chabbert, C.; Gaboyard-Niay, S.; Travo, C.; Machado, M.L.; Denise, P.; Comoz, F.; Hitier, M.; Landemore, G.; Philoxène, B.; Besnard, S.

2012-01-01

Several animal models of vestibular deficits that mimic the human pathology phenotype have previously been developed to correlate the degree of vestibular injury to cognate vestibular deficits in a time-dependent manner. Sodium arsanilate is one of the most commonly used substances for chemical vestibular lesioning, but it is not well described in the literature. In the present study, we used histological and functional approaches to conduct a detailed exploration of the model of vestibular lesions induced by transtympanic injection of sodium arsanilate in rats. The arsanilate-induced damage was restricted to the vestibular sensory organs without affecting the external ear, the oropharynx, or Scarpa's ganglion. This finding strongly supports the absence of diffusion of arsanilate into the external ear or Eustachian tubes, or through the eighth cranial nerve sheath leading to the brainstem. One of the striking observations of the present study is the complete restructuring of the sensory epithelia into a non sensory epithelial monolayer observed at 3 months after arsanilate application. This atrophy resembles the monolayer epithelia observed postmortem in the vestibular epithelia of patients with a history of lesioned vestibular deficits such as labyrinthectomy, antibiotic treatment, vestibular neuritis, or Ménière's disease. In cases of Ménière's disease, aminoglycosides, and platinum-based chemotherapy, vestibular hair cells are destroyed, regardless of the physiopathological process, as reproduced with the arsanilate model of vestibular lesion. These observations, together with those presented in this study of arsanilate vestibular toxicity, suggest that this atrophy process relies on a common mechanism of degeneration of the sensory epithelia.

Experimental nickel-induced pulmonary lesions in nonhuman primates: Histologic and ultrastructural analysis

International Nuclear Information System (INIS)

Haley, P.J.; Bice, D.E.; Muggenburg, B.A.; Hahn, F.F.

1988-01-01

The histologic and ultrastructural alterations of lung were evaluated in cynomolgus monkeys instilled with nickel subsulfide (Ni 3 S 2 ) at a final dose of 0.06 μmol/g lung with and without repeated intrapulmonary exposure to sheep red blood cells (SRBC). individual lung lobes were exposed to nickel alone, SRBC alone, or nickel and SRBC together. Lesions were found in nickel-exposed lobes only, regardless of exposure to SRBC. Lesions were more developed at 14 days than at 21 days after exposure to nickel, and were characterized by multifocal perivascular and peribronchiolar lymphocytic infiltrates along with microgranuloma formation, occasional fibrosis and moderate type II epithelial cell hyperplasia. Microgranulomas consisted of either central histiocytic cores surrounded by lymphocytic mantles or dense aggregates of epithelioid cells forming irregular interstitial nodules. Tracheobronchial lymph nodes had marked reactive hyperplasia of cortical and paracortical zones. Ultrastructural analysis of lung lesions revealed numerous well-differentiated lymphocytes intermixed with macrophages, in a background of mature collagen bundles. Cell associated particles were evaluated by energy dispersive microanalysis and found to consist of nickel and sulfur. These lesions appeared to be distinct from pneumoconiotic lesions induced by inert dusts and had histologic qualities compatible with immune-mediated phenomena. Because nickel compounds stimulate strong humoral and cellular immune responses in man, we conclude that pulmonary exposure of nonhuman primates to nickel compounds may provide information useful in delineating Immune mediated pulmonary disorders of man. (author)

The Physiologic Impact of Unilateral Recurrent Laryngeal Nerve (RLN) Lesion on Infant Oropharyngeal and Esophageal Performance.

Science.gov (United States)

Gould, Francois D H; Lammers, Andrew R; Ohlemacher, Jocelyn; Ballester, Ashley; Fraley, Luke; Gross, Andrew; German, Rebecca Z

2015-12-01

Recurrent laryngeal nerve (RLN) injury in neonates, a complication of patent ductus arteriosus corrective surgery, leads to aspiration and swallowing complications. Severity of symptoms and prognosis for recovery are variable. We transected the RLN unilaterally in an infant mammalian animal model to characterize the degree and variability of dysphagia in a controlled experimental setting. We tested the hypotheses that (1) both airway protection and esophageal function would be compromised by lesion, (2) given our design, variability between multiple post-lesion trials would be minimal, and (3) variability among individuals would be minimal. Individuals' swallowing performance was assessed pre- and post-lesion using high speed VFSS. Aspiration was assessed using the Infant Mammalian Penetration-Aspiration Scale (IMPAS). Esophageal function was assessed using two measures devised for this study. Our results indicate that RLN lesion leads to increased frequency of aspiration, and increased esophageal dysfunction, with significant variation in these basic patterns at all levels. On average, aspiration worsened with time post-lesion. Within a single feeding sequence, the distribution of unsafe swallows varied. Individuals changed post-lesion either by increasing average IMPAS score, or by increasing variation in IMPAS score. Unilateral RLN transection resulted in dysphagia with both compromised airway protection and esophageal function. Despite consistent, experimentally controlled injury, significant variation in response to lesion remained. Aspiration following RLN lesion was due to more than unilateral vocal fold paralysis. We suggest that neurological variation underlies this pattern.

A radiographic study of the experimental lesions in the maxillary sinus

International Nuclear Information System (INIS)

Lee, Joo Hyun; Hwang, Eui Hwan; Lee, Sang Rae

1994-01-01

The purpose of this study was to examine the differences in representation of a globular radiopaque mass on the pantomograms and Waters' views and to compare the efficacy of periapical radiograms, pantomograms and Waters' views in detection of defects on the internal walls of the maxillary sinus. This study was performed with dried human skull. For the study of difference of radiopaque mass shadow in the two views, rubber ball with a diameter of 10mm was used as the experimental lesion. It was placed successively on the internal wall of the anterior, posterior, medial, lateral walls and floor of the maxillary sinus. To examine the detectability of defects for radiographic techniques, defects were formed in the anterior, posterior, medial, lateral walls, and floor of the maxillary sinus. They were formed with 0.5 mm, 0.75 mm, 1.0 mm, 2.0 mm and 3.0 mm sized steel round burs with a slow speed dental handpiece. By subsequently plugging the holes with zinc oxide eugenol paste, radiopaque defects were produced. After that the periapical radiograms, the pantomograms and the Waters' views were taken each and every defect. The obtained results were as follows: 1. Rubber balls placed on each internal wall of maxillary sinus were correctly depicted on the posterior wall and the floor in case of the pantomogram, and on the anterior wall and the medial wall in case of the Waters' view. 2. On the detectability of defects for each radiographic technique, radiolucent defects were detected in different places of each technique. Periapical radiogram could detect 1.0 mm defect on the floor of the maxillary sinus, pantomogram could detect 2.0 mm defect on every internal wall of the maxillary sinus, and Waters' view could detect 3.0 mm defect on the anterior wall of the maxillary sinus. 3. On the detectability of defects for each radiographic technique, radiopaque defects were detected in different places for each technique. Periapical radiogram could clearly detect 0.5 mm defect on

An experimental two-stage rat model of lung carcinoma initiated by radon exposure

International Nuclear Information System (INIS)

Poncy, J.L.; Laroque, P.; Fritsch, P.; Monchaux, G.; Masse, R.; Chameaud, J.

1992-01-01

We present the results of a two-stage biological model of lung carcinogenesis in rats. The histogenesis of these tumors was examined, and DNA content of lung cells was measured by flow cytometry during the evolving neoplastic stage. Tumors were induced in rat lungs after radon inhalation (1600 WLM) followed by a promoter treatment; six intramuscular injections of 5,6-benzoflavone (25 mg/kg of body weight/injection) every 2 wk. Less than 3 mo after the first injection of benzoflavone, squamous cell carcinoma was observed in the lungs of all rats exposed to radon. The preneoplastic lesions gradually developed as follows: hyperplastic bronchiolar-type cells migrated to the alveoli from cells that proliferated in bronchioles and alveolar ducts; initial lesions were observed in almost all respiratory bronchioles. From some hyperplasias, epidermoid metaplasias arose distally, forming nodular epidermoid lesions in alveoli, which progressed to form squamous papilloma and, finally, epidermoid carcinomas. The histogenesis of these experimentally induced epidermoid carcinomas showed the bronchioloalveolar origin of the tumor. This factor must be considered when comparing these with human lesions; in humans, lung epidermoid carcinomas are thought to arise mainly in the first bronchial generations. The labeling index of pulmonary tissue after incorporation of 3 H-thymidine by the cells was 0.2% in control rats. This index reached a value of 1 to 2% in the hyperplastic area of the bronchioles and 10 to 15% in epidermoid nodules and epidermoid tumors, respectively. DNA cytometric analysis was performed on cell suspensions obtained after enzymatic treatment of paraffin sections of lungs from rats sacrificed during different stags of neoplastic transformations. Data showed the early appearance of a triploid cell population that grew during the evolution of nodular epidermoid lesions to epidermoid carcinomas

Experimental Model of Tuberculosis in the Domestic Goat after Endobronchial Infection with Mycobacterium caprae ▿

Science.gov (United States)

Pérez de Val, Bernat; López-Soria, Sergio; Nofrarías, Miquel; Martín, Maite; Vordermeier, H. Martin; Villarreal-Ramos, Bernardo; Romera, Nadine; Escobar, Manel; Solanes, David; Cardona, Pere-Joan; Domingo, Mariano

2011-01-01

Caprine tuberculosis (TB) has increased in recent years, highlighting the need to address the problem the infection poses in goats. Moreover, goats may represent a cheaper alternative for testing of prototype vaccines in large ruminants and humans. With this aim, a Mycobacterium caprae infection model has been developed in goats. Eleven 6-month-old goats were infected by the endobronchial route with 1.5 × 103 CFU, and two other goats were kept as noninfected controls. The animals were monitored for clinical and immunological parameters throughout the experiment. After 14 weeks, the goats were euthanized, and detailed postmortem analysis of lung lesions was performed by multidetector computed tomography (MDCT) and direct observation. The respiratory lymph nodes were also evaluated and cultured for bacteriological analysis. All infected animals were positive in a single intradermal comparative cervical tuberculin (SICCT) test at 12 weeks postinfection (p.i.). Gamma interferon (IFN-γ) antigen-specific responses were detected from 4 weeks p.i. until the end of the experiment. The humoral response to MPB83 was especially strong at 14 weeks p.i. (13 days after SICCT boost). All infected animals presented severe TB lesions in the lungs and associated lymph nodes. M. caprae was recovered from pulmonary lymph nodes in all inoculated goats. MDCT allowed a precise quantitative measure of TB lesions. Lesions in goats induced by M. caprae appeared to be more severe than those induced in cattle by M. bovis over a similar period of time. The present work proposes a reliable new experimental animal model for a better understanding of caprine tuberculosis and future development of vaccine trials in this and other species. PMID:21880849

Evaluation of the chemical model of vestibular lesions induced by arsanilate in rats

Energy Technology Data Exchange (ETDEWEB)

Vignaux, G. [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); Chabbert, C.; Gaboyard-Niay, S.; Travo, C. [INSERM U1051, Institut des Neurosciences de Montpellier, Montpellier, F-34090,France (France); Machado, M.L. [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); Denise, P. [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); CHRU Caen, Explorations Fonctionnelles, Caen, F-14000 (France); Comoz, F. [CHRU Caen, Laboratoire d' anatomopathologie, Caen, F-14000 (France); Hitier, M. [CHRU Caen, Service d' Otorhinolaryngologie, Caen, F-14000,France (France); Landemore, G. [CHRU Caen, Laboratoire d' anatomopathologie, Caen, F-14000 (France); Philoxène, B. [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); CHRU Caen, Explorations Fonctionnelles, Caen, F-14000 (France); Besnard, S., E-mail: besnard-s@phycog.org [INSERM, ERI27, Caen, F-14000 (France); Univ Caen, Caen, F-14000 (France); CHRU Caen, Explorations Fonctionnelles, Caen, F-14000 (France)

2012-01-01

Several animal models of vestibular deficits that mimic the human pathology phenotype have previously been developed to correlate the degree of vestibular injury to cognate vestibular deficits in a time-dependent manner. Sodium arsanilate is one of the most commonly used substances for chemical vestibular lesioning, but it is not well described in the literature. In the present study, we used histological and functional approaches to conduct a detailed exploration of the model of vestibular lesions induced by transtympanic injection of sodium arsanilate in rats. The arsanilate-induced damage was restricted to the vestibular sensory organs without affecting the external ear, the oropharynx, or Scarpa's ganglion. This finding strongly supports the absence of diffusion of arsanilate into the external ear or Eustachian tubes, or through the eighth cranial nerve sheath leading to the brainstem. One of the striking observations of the present study is the complete restructuring of the sensory epithelia into a non sensory epithelial monolayer observed at 3 months after arsanilate application. This atrophy resembles the monolayer epithelia observed postmortem in the vestibular epithelia of patients with a history of lesioned vestibular deficits such as labyrinthectomy, antibiotic treatment, vestibular neuritis, or Ménière's disease. In cases of Ménière's disease, aminoglycosides, and platinum-based chemotherapy, vestibular hair cells are destroyed, regardless of the physiopathological process, as reproduced with the arsanilate model of vestibular lesion. These observations, together with those presented in this study of arsanilate vestibular toxicity, suggest that this atrophy process relies on a common mechanism of degeneration of the sensory epithelia.

Complement mRNA in the mammalian brain: responses to Alzheimer's disease and experimental brain lesioning.

Science.gov (United States)

Johnson, S A; Lampert-Etchells, M; Pasinetti, G M; Rozovsky, I; Finch, C E

1992-01-01

This study describes evidence in the adult human and rat brain for mRNAs that encode two complement (C) proteins, C1qB and C4. C proteins are important effectors of humoral immunity and inflammation in peripheral tissues but have not been considered as normally present in brain. Previous immunocytochemical studies showed that C proteins are associated with plaques, tangles, and dystrophic neurites in Alzheimer's disease (AD), but their source is unknown. Combined immunocytochemistry and in situ hybridization techniques show C4 mRNA in pyramidal neurons and C1qB mRNA in microglia. Primary rat neuron cultures also show C1qB mRNA. In the cortex from AD brains, there were two- to threefold increases of C1qB mRNA and C4 mRNA, and increased C1qB mRNA prevalence was in part associated with microglia. As a model for AD, we examined entorhinal cortex perforant path transection in the rat brain, which caused rapid increases of C1qB mRNA in the ipsilateral, but not contralateral, hippocampus and entorhinal cortex. The role of brain-derived acute and chronic C induction during AD and experimental lesions can now be considered in relation to functions of C proteins that pertain to cell degeneration and/or cell preservation and synaptic plasticity.

Lesions in Porcine Liver Tissues Created by Continuous High Intensity Ultrasound Exposures in Vitro

International Nuclear Information System (INIS)

Zhang Zhe; Chen Tao; Zhang Dong

2013-01-01

Lesions in porcine liver tissues created by continuous high intensity focused ultrasound (HIFU) exposures in vitro are theoretically and experimentally investigated, with the transmitter moving along a linear path at a fixed speed. Numerical simulations of the lesion formation are performed based on the Khokhlov—Zabolotskaya—Kuznetov equation and the bio-heat equation. In order to verify the theoretical predictions, experiments are performed in the one-dimensional scanning mode to measure the cross-sectional area of lesions created in the in vitro porcine liver exposed to 1.01-MHz HIFU pulses with the acoustic power of 70 W. The results indicate that, compared to the traditional discrete treatment protocol, the application of a continuous scanning model can create more uniform lesions in tissues and significantly reduces the total treatment time from 47s to 30s

Inter-algorithm lesion volumetry comparison of real and 3D simulated lung lesions in CT

Science.gov (United States)

Robins, Marthony; Solomon, Justin; Hoye, Jocelyn; Smith, Taylor; Ebner, Lukas; Samei, Ehsan

2017-03-01

The purpose of this study was to establish volumetric exchangeability between real and computational lung lesions in CT. We compared the overall relative volume estimation performance of segmentation tools when used to measure real lesions in actual patient CT images and computational lesions virtually inserted into the same patient images (i.e., hybrid datasets). Pathologically confirmed malignancies from 30 thoracic patient cases from Reference Image Database to Evaluate Therapy Response (RIDER) were modeled and used as the basis for the comparison. Lesions included isolated nodules as well as those attached to the pleura or other lung structures. Patient images were acquired using a 16 detector row or 64 detector row CT scanner (Lightspeed 16 or VCT; GE Healthcare). Scans were acquired using standard chest protocols during a single breath-hold. Virtual 3D lesion models based on real lesions were developed in Duke Lesion Tool (Duke University), and inserted using a validated image-domain insertion program. Nodule volumes were estimated using multiple commercial segmentation tools (iNtuition, TeraRecon, Inc., Syngo.via, Siemens Healthcare, and IntelliSpace, Philips Healthcare). Consensus based volume comparison showed consistent trends in volume measurement between real and virtual lesions across all software. The average percent bias (+/- standard error) shows -9.2+/-3.2% for real lesions versus -6.7+/-1.2% for virtual lesions with tool A, 3.9+/-2.5% and 5.0+/-0.9% for tool B, and 5.3+/-2.3% and 1.8+/-0.8% for tool C, respectively. Virtual lesion volumes were statistically similar to those of real lesions (.05 in most cases. Results suggest that hybrid datasets had similar inter-algorithm variability compared to real datasets.

Interpretation of proton relative biological effectiveness using lesion induction, lesion repair, and cellular dose distribution

International Nuclear Information System (INIS)

Paganetti, H.

2005-01-01

Phenomenological biophysical models have been successfully used to estimate the relative biological effectiveness (RBE) of ions. The predictive power of these models is limited because they require measured dose-response data that are not necessarily available for all clinically relevant end points. Furthermore, input parameters often lack mechanistic interpretation. In order to link RBE to more fundamental biological parameters we combine the concepts of two well-established biophysical models, i.e., the phenomenological 'track structure' model and the more mechanistic 'lethal lesion/potentially lethal lesion' (LPL) model. We parametrize a relation between RBE, dose homogeneity in the cell nucleus and induction rates for different lesion types. The macroscopic dose-response relationship is described in the LPL model and the microscopic, subcellular, relationship is determined by the local dose deposition pattern. The formalism provides a framework for a mechanistic interpretation of RBE values

Mapping 3D breast lesions from full-field digital mammograms using subject-specific finite element models

Science.gov (United States)

García, E.; Oliver, A.; Diaz, O.; Diez, Y.; Gubern-Mérida, A.; Martí, R.; Martí, J.

2017-03-01

Patient-specific finite element (FE) models of the breast have received increasing attention due to the potential capability of fusing images from different modalities. During the Magnetic Resonance Imaging (MRI) to X-ray mammography registration procedure, the FE model is compressed mimicking the mammographic acquisition. Subsequently, suspicious lesions in the MRI volume can be projected into the 2D mammographic space. However, most registration algorithms do not provide the reverse information, avoiding to obtain the 3D geometrical information from the lesions localized in the mammograms. In this work we introduce a fast method to localize the 3D position of the lesion within the MRI, using both cranio-caudal (CC) and medio-lateral oblique (MLO) mammographic projections, indexing the tetrahedral elements of the biomechanical model by means of an uniform grid. For each marked lesion in the Full-Field Digital Mammogram (FFDM), the X-ray path from source to the marker is calculated. Barycentric coordinates are computed in the tetrahedrons traversed by the ray. The list of elements and coordinates allows to localize two curves within the MRI and the closest point between both curves is taken as the 3D position of the lesion. The registration errors obtained in the mammographic space are 9.89 +/- 3.72 mm in CC- and 8.04 +/- 4.68 mm in MLO-projection and the error in the 3D MRI space is equal to 10.29 +/- 3.99 mm. Regarding the uniform grid, it is computed spending between 0.1 and 0.7 seconds. The average time spent to compute the 3D location of a lesion is about 8 ms.

Determinants for swine mycoplasmal pneumonia reproduction under experimental conditions: A systematic review and recursive partitioning analysis

Science.gov (United States)

Garcia-Morante, Beatriz; Segalés, Joaquim; Serrano, Emmanuel

2017-01-01

One of the main Mycoplasma hyopneumoniae (M. hyopneumoniae) swine experimental model objectives is to reproduce mycoplasmal pneumonia (MP). Unfortunately, experimental validated protocols to maximize the chance to successfully achieve lung lesions induced by M. hyopneumoniae are not available at the moment. Thus, the objective of this work was to identify those factors that might have a major influence on the effective development of MP, measured as macroscopic lung lesions, under experimental conditions. Data from 85 studies describing M. hyopneumoniae inoculation experiments were compiled by means of a systematic review and analyzed thereafter. Several variables were considered in the analyses such as the number of pigs in the experiment, serological status against M. hyopneumoniae, source of the animals, age at inoculation, type of inoculum, strain of M. hyopneumoniae, route, dose and times of inoculation, study duration and co-infection with other swine pathogens. Descriptive statistics were used to depict M. hyopneumoniae experimental model main characteristics whereas a recursive partitioning approach, using regression trees, assessed the importance of the abovementioned experimental variables as MP triggering factors. A strong link between the time period between challenge and necropsies and lung lesion severity was observed. Results indicated that the most important factors to explain the observed lung lesion score variability were: (1) study duration, (2) M. hyopneumoniae strain, (3) age at inoculation, (4) co-infection with other swine pathogens and (5) animal source. All other studied variables were not relevant to explain the variability on M. hyopneumoniae lung lesions. The results provided in the present work may serve as a basis for debate in the search for a universally accepted M. hyopneumoniae challenge model. PMID:28742802

Determinants for swine mycoplasmal pneumonia reproduction under experimental conditions: A systematic review and recursive partitioning analysis.

Directory of Open Access Journals (Sweden)

Beatriz Garcia-Morante

Full Text Available One of the main Mycoplasma hyopneumoniae (M. hyopneumoniae swine experimental model objectives is to reproduce mycoplasmal pneumonia (MP. Unfortunately, experimental validated protocols to maximize the chance to successfully achieve lung lesions induced by M. hyopneumoniae are not available at the moment. Thus, the objective of this work was to identify those factors that might have a major influence on the effective development of MP, measured as macroscopic lung lesions, under experimental conditions. Data from 85 studies describing M. hyopneumoniae inoculation experiments were compiled by means of a systematic review and analyzed thereafter. Several variables were considered in the analyses such as the number of pigs in the experiment, serological status against M. hyopneumoniae, source of the animals, age at inoculation, type of inoculum, strain of M. hyopneumoniae, route, dose and times of inoculation, study duration and co-infection with other swine pathogens. Descriptive statistics were used to depict M. hyopneumoniae experimental model main characteristics whereas a recursive partitioning approach, using regression trees, assessed the importance of the abovementioned experimental variables as MP triggering factors. A strong link between the time period between challenge and necropsies and lung lesion severity was observed. Results indicated that the most important factors to explain the observed lung lesion score variability were: (1 study duration, (2 M. hyopneumoniae strain, (3 age at inoculation, (4 co-infection with other swine pathogens and (5 animal source. All other studied variables were not relevant to explain the variability on M. hyopneumoniae lung lesions. The results provided in the present work may serve as a basis for debate in the search for a universally accepted M. hyopneumoniae challenge model.

Experimental autoimmune encephalomyelitis (EAE): lesion visualization on a 3 tesla Clinical whole-body system after intraperitoneal contrast injection

Energy Technology Data Exchange (ETDEWEB)

Heckl, S.; Naegele, T.; Klose, U. [Dept. of Neuroradiology, Medical School, Univ. of Tuebingen (Germany); Herrmann, M.; Gaertner, S.; Weissert, R. [Dept. of Neurology, Medical School, Univ. of Tuebingen (Germany); Schick, F. [Dept. of Radiology, Medical School, Univ. of Tuebingen (Germany); Kueker, W. [Dept. of Neuroradiology, Medical School, Univ. of Tuebingen (Germany); Dept. of Neuroradiology, Radcliffe Infirmary, Oxford, England (United Kingdom)

2004-11-01

Purpose: To investigate the intravital visibility of CNS lesions in rats with experimental autoimmune encephalomyelitis (EAE), the animal correlate of multiple sclerosis, using a 3-Tesla (T) wholebody MR system. Materials and Methods: Three healthy Dark Agouti (DA) rats and 16 DA rats with clinical signs of EAE were examined on a 3T whole body-system using a normal wrist coil. In total, 25 examinations were preformed using T2- and T1-weighted images in transverse and sagittal orientation with a slice thickness of 2 mm or 1 mm (voxel size up to 0.2 x 0.2 x 1 mm). Sedation was achieved by intraperitoneal injection of ketamine and xylazine. In addition, T1-weighted images were obtained after the instillation of 1.0 ml of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) (0.5 mmol/ml) into the peritoneal cavity. Results: T2- and T1-weighted images of the brain and spinal cord with high spatial and contrast resolution could be obtained in all animals. The anatomical details of the olfactory bulb glomeruli, cerebellum foliae, ventricles and corpus callosum were clearly visible. The EAE lesions presented as hyperintense area in T2-weighted images and could be demonstrated in all clinically affected animals by MRI and histologically verified. In total, the 16 affected rats had 28 cerebral and 2 spinal cord lesions (range 1 to 4, median 2). Contrast enhancement was noted in 12 animals and ranked as severe in ten and moderate in two cases. No adverse effects were noted due to sedation or intraperitoneal contrast injection. Conclusions: The intravital demonstration of cerebral and spinal cord EAE lesions in rats is possible on a 3T whole-body MR scanner using a normal wrist coil. Intraperitoneal injection of ketamine/xylazine and contrast agent is an easy, safe and effective procedure in rats. (orig.)

Experimental autoimmune encephalomyelitis (EAE): lesion visualization on a 3 tesla Clinical whole-body system after intraperitoneal contrast injection

International Nuclear Information System (INIS)

Heckl, S.; Naegele, T.; Klose, U.; Herrmann, M.; Gaertner, S.; Weissert, R.; Schick, F.; Kueker, W.

2004-01-01

Purpose: To investigate the intravital visibility of CNS lesions in rats with experimental autoimmune encephalomyelitis (EAE), the animal correlate of multiple sclerosis, using a 3-Tesla (T) wholebody MR system. Materials and Methods: Three healthy Dark Agouti (DA) rats and 16 DA rats with clinical signs of EAE were examined on a 3T whole body-system using a normal wrist coil. In total, 25 examinations were preformed using T2- and T1-weighted images in transverse and sagittal orientation with a slice thickness of 2 mm or 1 mm (voxel size up to 0.2 x 0.2 x 1 mm). Sedation was achieved by intraperitoneal injection of ketamine and xylazine. In addition, T1-weighted images were obtained after the instillation of 1.0 ml of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA) (0.5 mmol/ml) into the peritoneal cavity. Results: T2- and T1-weighted images of the brain and spinal cord with high spatial and contrast resolution could be obtained in all animals. The anatomical details of the olfactory bulb glomeruli, cerebellum foliae, ventricles and corpus callosum were clearly visible. The EAE lesions presented as hyperintense area in T2-weighted images and could be demonstrated in all clinically affected animals by MRI and histologically verified. In total, the 16 affected rats had 28 cerebral and 2 spinal cord lesions (range 1 to 4, median 2). Contrast enhancement was noted in 12 animals and ranked as severe in ten and moderate in two cases. No adverse effects were noted due to sedation or intraperitoneal contrast injection. Conclusions: The intravital demonstration of cerebral and spinal cord EAE lesions in rats is possible on a 3T whole-body MR scanner using a normal wrist coil. Intraperitoneal injection of ketamine/xylazine and contrast agent is an easy, safe and effective procedure in rats. (orig.)

Genital tract lesions in sexually mature Göttingen minipigs during the initial stages of experimental vaginal infection with Chlamydia trachomatis serovar D.

Science.gov (United States)

Erneholm, Karin; Lorenzen, Emma; Bøje, Sarah; Olsen, Anja Weinreich; Andersen, Peter; Cassidy, Joseph P; Follmann, Frank; Jensen, Henrik E; Agerholm, Jørgen S

2016-09-10

Chlamydia is one of the most common sexually transmitted diseases in humans worldwide, causing chronic lesions in the reproductive tract. Due to its often asymptomatic course, there is limited knowledge about the initial changes in the genital tract following infection. This study employs a novel sexually mature minipig model to investigate the initial histopathological changes following vaginal infection with Chlamydia trachomatis serovar D. A vaginal inoculation resulted in an infection primarily affecting the lower genital tract. The histopathological changes were characterized by a subepithelial inflammation consisting of neutrophils and mononuclear cells, followed by an increase in the number of plasma cells within the sub-epithelial stroma of the vagina. Detection of Chlamydia was associated with expression of cyclooxygenase-2 and interleukin-8 by superficial epithelial cells. The infection was self-limiting, with a duration of 7 days. Neutrophils, plasma cells and IL-8 have been linked with Chlamydia genital infection of unknown duration in human patients. In this study, we observe a similar pattern of local immune response/inflammation following experimental inoculation suggesting this porcine model shows promise as a model for translational chlamydia research.

Temporal Progression of Lesions in Guinea Pigs Infected With Lassa Virus.

Science.gov (United States)

Bell, T M; Shaia, C I; Bearss, J J; Mattix, M E; Koistinen, K A; Honnold, S P; Zeng, X; Blancett, C D; Donnelly, G C; Shamblin, J D; Wilkinson, E R; Cashman, K A

2017-05-01

Lassa virus (LASV) infection causes an acute, multisystemic viral hemorrhagic fever that annually infects an estimated 100 000 to 300 000 persons in West Africa. This pathogenesis study evaluated the temporal progression of disease in guinea pigs following aerosol and subcutaneous inoculation of the Josiah strain of LASV as well as the usefulness of Strain 13 guinea pigs as an animal model for Lassa fever. After experimental infection, guinea pigs ( Cavia porcellus; n = 67) were serially sampled to evaluate the temporal progression of infection, gross and histologic lesions, and serum chemistry and hematologic changes. Guinea pigs developed viremia on day 5 to 6 postexposure (PE), with clinical signs appearing by day 7 to 8 PE. Complete blood counts revealed lymphopenia and thrombocytopenia. Gross pathologic findings included skin lesions and congested lungs. Histologic lesions consisted of cortical lymphoid depletion by day 6 to 7 PE with lymphohistiocytic interstitial pneumonia at 7 to 8 days PE. Scattered hepatocellular degeneration and cell death were also noted in the liver and, to a lesser extent, in other tissues including the haired skin, lung, heart, adrenal gland, lymph nodes, thymus, and spleen. The first cell types to demonstrate staining for viral antigen were fibroblastic reticular cells and macrophages/dendritic cells in the lymph nodes on day 5 to 6 PE. This study demonstrates similarities between Lassa viral disease in human infections and experimental guinea pig infection. These shared pathologic characteristics support the utility of guinea pigs as an additional animal model for vaccine and therapeutic development under the Food and Drug Administration's Animal Rule.

Experimental alkylmercurial poisoning in swine. Lesions in the peripheral and central nervous systems

Energy Technology Data Exchange (ETDEWEB)

Charlton, K M

1974-01-01

The effects of alkylmercurial poisoning were studied in 16 pigs poisoned with daily oral doses of a fungicide containing methylmercury 2, 3-dihydroxy propyl mercaptide and methylmercury acetate. Clinical signs included weakness, wobbling gait, blindness, recumbency and death. Microscopic studies of the peripheral nervous system revealed Wallerian degeneration in sensory fibers and neuronal degeneration in dorsal root ganglia. In the central nervous system, there were neuronal degeneration of ischemic type, glial degeneration, gliosis and necrosis of the media of meningeal arterioles. The last mentioned lesion was not extensive. The sequential development of lesions and the absence of segmental demyelination suggest that the primary lesion in the peripheral nervous system was neuronal-axonal degeneration rather than degeneration of the Schwann cell and myelin sheath. 25 references.

Hypoxia and oxidation levels of DNA and lipids in humans and animal experimental models

DEFF Research Database (Denmark)

Møller, Peter; Risom, Lotte; Lundby, Carsten

2008-01-01

The objective of this review was to evaluate the association between hypoxia and oxidative damage to DNA and lipids. Evaluation criteria encompassed specificity and validation status of the biomarkers, study design, strength of the association, dose-response relationship, biological plausibility......, analogous exposures, and effect modification by intervention. The collective interpretation indicates persuasive evidence from the studies in humans for an association between hypoxia and elevated levels of oxidative damage to DNA and lipids. The levels of oxidatively generated DNA lesions and lipid...... in subjects at high altitude. Most of the animal experimental models should be interpreted with caution because the assays for assessment of lipid peroxidation products have suboptimal validity....

Are dinucleoside monophosphates relevant models for the study of DNA intrastrand cross-link lesions? The example of g[8-5m]T.

Science.gov (United States)

Garrec, Julian; Dumont, Elise

2014-07-21

Oxidatively generated tandem lesions such as G[8-5m]T pose a potent threat to genome integrity. Direct experimental studies of the kinetics and thermodynamics of a specific lesion within DNA are very challenging, mostly due to the variety of products that can be formed in oxidative conditions. Dinucleoside monophosphates (DM) involving only the reactive nucleobases in water represent appealing alternative models on which most physical chemistry and structural techniques can be applied. However, it is not yet clear how relevant these models are. Here, we present QM/MM MD simulations of the cyclization step involved in the formation of G[8-5m]T from the guanine-thymine (GpT) DM in water, with the aim of comparing our results to our previous investigation of the same reaction in DNA ( Garrec , J. , Patel , C. , Rothlisberger , U. , and Dumont , E. ( 2012 ) J. Am. Chem. Soc. 134 , 2111 - 2119 ). We show that, despite the different levels of preorganization of the two systems, the corresponding reactions share many energetic and structural characteristics. The main difference lies in the angle between the G and T bases, which is slightly higher in the transition state (TS) and product of the reaction in water than in the reaction in DNA. This effect is due to the Watson-Crick H-bonds, which are absent in the {GpT+water} system and restrain the relative positioning of the reactive nucleobases in DNA. However, since the lesion is accommodated easily in the DNA macromolecule, the induced energetic penalty is relatively small. The high similarity between the two reactions strongly supports the use of GpT in water as a model of the corresponding reaction in DNA.

Exploration of central dopamine D2 receptors by autoradiography, pathology and functional behaviour observation in rat model with experimental parkinsonism

International Nuclear Information System (INIS)

Lin Yansong; Lin Xiangtong

1996-01-01

The rat model with experimental parkinsonism mimic the course of human parkinsonism were made by cerebral-stereotaxic techniques. 125 I-IBZM was used to evaluate the D 2 receptors distribution by autoradiographic analysis of coronal brain section. In 6 parkinsonism model rats, on the lesioned side the striatum/frontal cortex ratio was 5.32 +- 0.37, it was significantly (P 125 I-IBZM as the ligand of D 2 receptor can well reflect the distribution and changes of D 2 receptors, and also as the theoretical basis for the clinical imaging diagnosis

Effects of insulin and glucose loading on FDG uptake in experimental malignant tumours and inflammatory lesions

International Nuclear Information System (INIS)

Zhao, Songji; Tsukamoto, Eriko; Kato, Takashi; Tamaki, Nagara; Kuge, Yuji; Hikosaka, Kenji; Mochizuki, Takafumi; Hosokawa, Masuo; Kohanawa, Masashi

2001-01-01

Fluorine-18 2-deoxy-2-fluoro-D-glucose (FDG) accumulation in tumours has been well investigated, but much less is known regarding FDG accumulation in inflammatory lesions. In this study, we determined the effects of hypo- and hyperglycaemia on FDG uptake in inflammatory lesions of infectious and non-infectious origin and compared them with those in malignant tumours in rats, to provide a biological basis for differentiating malignant lesions from benign lesions by means of FDG-PET. Rats were inoculated with a suspension of allogenic hepatoma cells (KDH-8) or Staphylococcus aureus, or with turpentine oil into the left calf muscle. Two weeks after KDH-8 inoculation and 1 week after S. aureus and turpentine oil inoculations, the rats were divided into three subgroups: insulin-loaded (2 U/kg body weight, i.p.), glucose-loaded (1.2 g/kg body weight, p.o.) and control groups. Radioactivity in tissues was determined 1 h after i.v. injection of FDG. Intraperitoneal injection of insulin and oral administration of glucose induced hypoglycaemia and hyperglycaemia, respectively. In the control animals, tumours showed a level of FDG uptake which was 2.2 and 3.0 times higher than the levels in the inflammatory lesions induced by S. aureus and turpentine oil, respectively (P<0.0001). There was no significant difference in the level of FDG uptake between the two inflammatory lesions of infectious and non-infectious origin. Insulin loading significantly decreased the level of FDG uptake in tumours and in both types of inflammatory lesion to approximately one-half of the control values (P=0.001 in the tumour group and P<0.0001 in the two inflammatory lesion groups). In the glucose-loaded group, the level of FDG uptake in both types of inflammatory lesion decreased significantly to 50%-61% of the control value (P=0.0002 in the S.aureus group and P<0.0001 in the turpetine group), while the tumour uptake did not decrease significantly (86% of the control value) (P=NS). It is concluded

Targeting of macrophages for the scintigraphic evaluation of inflammatory lesions in a model of radio-induced inflammation in pigs

International Nuclear Information System (INIS)

Hoffschir, D.; Daburon, F.; Normier, G.; Binz, H.; Le Pape, A.

1991-01-01

For a new scintigraphic strategy based on the targeting of macrophages recruited by inflammatory lesions, a specific ligand able to interact with these cells both in vitro and in vivo has been developed. J001 is a 34 KDa acylated peptidopoly 1-3 galactoside isolated from proteoglycans of a non pathogenic strain of klebsiella. When labelled with 99mTc then administrated by aerosol, this agent has been demonstrated to be a potent tool for the scintigraphic imaging of inflammatory lymph nodes in experimental berylliosis and in patients with sarcoidosis, lung tumors and ganglionic metastases. An experimental model was developed in pigs using an acute and localized muscular γ irradiation in the limb and skin resection to prevent ulceration. Dynamic imaging was performed during two hours after intravenous injection of 1 mg J001 labelled with 370 MBq 99mTc in the presence of 0.125 mg stannous fluoride. The perfusion of the lesions was evaluated from scintigraphic data obtained both 15 min after IV injection of J001 or 99mTc 04-. The intensity of the fixation of J001 was quantified 2 hours after injection and expressed as a scintigraphic ratio: R2h = cpm in lesion / cpm in a defined healthy area in the same limb. After induction of irradiation, scintigraphic ratios exhibited a progressive increase to reach a maximum (R2h = 3.6) after 3 months. Then, they decreased to recover a normal value about 6 months after irradiation. At that time, histological controls and clinical observations exhibited a significant decrease in inflammatory reaction, macrophages recruitment and apparition of fibrosis. J001 fixation was very sensitive to corticosteroids that resulted in a complete clearing of the scintigraphic images 12 to 24 hours after treatment. Two weeks were then required for a complete recovery of the inflammatory reaction and J001 fixation. So, targeting of macrophages with J001 should offer a sensitive and specific tool for the scintigraphic assessment of inflammation and

Unilateral Superior Laryngeal Nerve Lesion in an Animal Model of Dysphagia and Its Effect on Sucking and Swallowing

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Campbell-Malone, Regina; Holman, Shaina D.; Lukasik, Stacey L.; Fukuhara, Takako; Gierbolini-Norat, Estela M.; Thexton, Allan J.; German, Rebecca Z.

2013-01-01

We tested two hypotheses relating to the sensory deficit that follows a unilateral superior laryngeal nerve (SLN) lesion in an infant animal model. We hypothesized that it would result in (1) a higher incidence of aspiration and (2) temporal changes in sucking and swallowing. We ligated the right-side SLN in six 2–3-week-old female pigs. Using videofluoroscopy, we recorded swallows in the same pre- and post-lesion infant pigs. We analyzed the incidence of aspiration and the duration and latency of suck and swallow cycles. After unilateral SLN lesioning, the incidence of silent aspiration during swallowing increased from 0.7 to 41.5 %. The durations of the suck containing the swallow, the suck immediately following the swallow, and the swallow itself were significantly longer in the post-lesion swallows, although the suck prior to the swallow was not different. The interval between the start of the suck containing a swallow and the subsequent epiglottal movement was longer in the post-lesion swallows. The number of sucks between swallows was significantly greater in post-lesion swallows compared to pre-lesion swallows. Unilateral SLN lesion increased the incidence of aspiration and changed the temporal relationships between sucking and swallowing. The longer transit time and the temporal coordinative dysfunction between suck and swallow cycles may contribute to aspiration. These results suggest that swallow dysfunction and silent aspiration are common and potentially overlooked sequelae of unilateral SLN injury. This validated animal model of aspiration has the potential for further dysphagia studies. PMID:23417250

Shaofu Zhuyu Decoction Regresses Endometriotic Lesions in a Rat Model

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Guanghui Zhu

2018-01-01

Full Text Available The current therapies for endometriosis are restricted by various side effects and treatment outcome has been less than satisfactory. Shaofu Zhuyu Decoction (SZD, a classic traditional Chinese medicinal (TCM prescription for dysmenorrhea, has been widely used in clinical practice by TCM doctors to relieve symptoms of endometriosis. The present study aimed to investigate the effects of SZD on a rat model of endometriosis. Forty-eight female Sprague-Dawley rats with regular estrous cycles went through autotransplantation operation to establish endometriosis model. Then 38 rats with successful ectopic implants were randomized into two groups: vehicle- and SZD-treated groups. The latter were administered SZD through oral gavage for 4 weeks. By the end of the treatment period, the volume of the endometriotic lesions was measured, the histopathological properties of the ectopic endometrium were evaluated, and levels of proliferating cell nuclear antigen (PCNA, CD34, and hypoxia inducible factor- (HIF- 1α in the ectopic endometrium were detected with immunohistochemistry. Furthermore, apoptosis was assessed using the terminal deoxynucleotidyl transferase (TdT deoxyuridine 5′-triphosphate (dUTP nick-end labeling (TUNEL assay. In this study, SZD significantly reduced the size of ectopic lesions in rats with endometriosis, inhibited cell proliferation, increased cell apoptosis, and reduced microvessel density and HIF-1α expression. It suggested that SZD could be an effective therapy for the treatment and prevention of endometriosis recurrence.

Gender, Estrogen, and Obliterative Lesions in the Lung

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Hamza Assaggaf

2017-01-01

Full Text Available Gender has been shown to impact the prevalence of several lung diseases such as cancer, asthma, chronic obstructive pulmonary disease, and pulmonary arterial hypertension (PAH. Controversy over the protective effects of estrogen on the cardiopulmonary system should be of no surprise as clinical trials of hormone replacement therapy have failed to show benefits observed in experimental models. Potential confounders to explain these inconsistent estrogenic effects include the dose, cellular context, and systemic versus local tissue levels of estrogen. Idiopathic PAH is disproportionately found to be up to 4 times more common in females than in males; however, estrogen levels cannot explain why males develop PAH sooner and have poorer survival. Since the sex steroid hormone 17β-estradiol is a mitogen, obliterative processes in the lung such as cell proliferation and migration may impact the growth of pulmonary tissue or vascular cells. We have reviewed evidence for biological differences of sex-specific lung obliterative lesions and highlighted cell context-specific effects of estrogen in the formation of vessel lumen-obliterating lesions. Based on this information, we provide a biological-based mechanism to explain the sex difference in PAH severity as well as propose a mechanism for the formation of obliterative vascular lesions by estrogens.

Red lesion detection using background estimation and lesions characteristics in diabetic retinal image

Science.gov (United States)

Zhang, Dongbo; Peng, Yinghui; Yi, Yao; Shang, Xingyu

2013-10-01

Detection of red lesions [hemorrhages (HRs) and microaneurysms (MAs)] is crucial for the diagnosis of early diabetic retinopathy. A method based on background estimation and adapted to specific characteristics of HRs and MAs is proposed. Candidate red lesions are located by background estimation and Mahalanobis distance measure and then some adaptive postprocessing techniques, which include vessel detection, nonvessel exclusion based on shape analysis, and noise points exclusion by double-ring filter (only used for MAs detection), are conducted to remove nonlesion pixels. The method is evaluated on our collected image dataset, and experimental results show that it is better than or approximate to other previous approaches. It is effective to reduce the false-positive and false-negative results that arise from incomplete and inaccurate vessel structure.

Gypenosides attenuate the development of L-DOPA-induced dyskinesia in 6-hydroxydopamine-lesioned rat model of Parkinson's disease.

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Shin, Keon Sung; Zhao, Ting Ting; Park, Keun Hong; Park, Hyun Jin; Hwang, Bang Yeon; Lee, Chong Kil; Lee, Myung Koo

2015-04-21

Gypenosides (GPS) and ethanol extract of Gynostemma pentaphyllum (GP-EX) show anxiolytic effects on affective disorders in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-lesioned mouse model of Parkinson's disease (PD). Long-term administration of L-3,4-dihydroxyphenylalanine (L-DOPA) leads to the development of severe motor side effects such as L-DOPA-induced-dyskinesia (LID) in PD. The present study investigated the effects of GPS and GP-EX on LID in a 6-hydroxydopamine (6-OHDA)-lesioned rat model of PD. Daily administration of L-DOPA (25 mg/kg) in the 6-OHDA-lesioned rat model of PD for 22 days induced expression of LID, which was determined by the body and locomotive AIMs scores and contralateral rotational behaviors. However, co-treatments of GPS (25 and 50 mg/kg) or GP-EX (50 mg/kg) with L-DOPA significantly attenuated the development of LID without compromising the anti-parkinsonian effects of L-DOPA. In addition, the increases in ∆FosB expression and ERK1/2 phosphorylation in 6-OHDA-lesioned rats induced by L-DOPA administration were significantly reduced by co-treatment with GPS (25 and 50 mg/kg) or GP-EX (50 mg/kg). These results suggest that GPS (25 and 50 mg/kg) and GP-EX (50 mg/kg) effectively attenuate the development of LID by modulating the biomarker activities of ∆FosB expression and ERK1/2 phosphorylation in the 6-OHDA-lesioned rat model of PD. GPS and GP-EX will be useful adjuvant therapeutics for LID in PD.

New Perspectives on the Brain Lesion Approach - Implications for Theoretical Models of Human Memory.

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Irish, Muireann; van Kesteren, Marlieke T R

2018-03-15

Human lesion studies represent the cornerstone of modern day neuropsychology and provide an important adjunct to functional neuroimaging methods. The study of human lesion groups with damage to distinct regions of the brain permits the identification of underlying mechanisms and structures not only associated with, but essential for, complex cognitive processes. Here, we consider a recent review by McCormick et al., 2018 in which the power of the lesion model approach is elegantly presented with respect to a host of sophisticated cognitive endeavors, including autobiographical memory, future thinking, spatial navigation, and decision-making. By comparing profiles of loss and sparing in hippocampal (HC) and ventromedial prefrontal cortex (vmPFC) lesion groups, the authors provide new insights into the underlying neuroarchitecture of these diverse cognitive functions. Building on this framework, we consider how vmPFC and HC degeneration, in the context of large-scale network dysfunction in dementia, impacts discrete facets of memory and social cognition. Notably, we find remarkable concordance between the available evidence in dementia and that of the HC and vmPFC lesion literature. We further assess the role of the prefrontal cortex in modulating aspects of spatial navigation and discuss the role of schema-related processing in the service of memory more broadly. Far from being obsolete, we contend that human lesion work occupies a crucial position in cognitive neuroscience and offers an array of exciting areas for future study within this field. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Effects of new biomimetic regenerating agents on corneal wound healing in an experimental model of post-surgical corneal ulcers.

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Alcalde, I; Íñigo-Portugués, A; Carreño, N; Riestra, A C; Merayo-Lloves, J M

2015-10-01

The purpose of this study is to assess the effectiveness of the topical application of cacicol regenerating agent (RGTA) in an experimental model of corneal ulcer after photorefractive keratectomy (PRK) in mice. Mice were subjected to PRK surgery with a 2.0mm ablation zone on the central cornea and 45mm of depth on a VISX Star S2 excimer laser. Corneas were treated topically with cacicol drops 1hour and 48hours after injury. Control groups received balanced salt solution (BSS) in the same dosage. Clinical and histopathological events were evaluated at 1, 2, 3 and 7 days after surgery. Sections obtained through the central region of the corneas were used to analyze the histopathological events of injured and healed corneas. αSMA (myofibroblast transformation), E cadherin (assembly of epithelial cells) and neuronal class III β-tubulin (innervation) were performed. Corneas treated topically with cacicol for 7 days showed a greater degree of transparency compared to controls. cacicol treated corneas showed improved epithelial cytoarchitecture. Analysis of αSMA profiles in the stroma showed that cacicol reduced or delayed the presence of myofibroblasts in the stroma compared to BSS (P<0.001). Finally, a putative neuroregenerative effect of cacicol was found in corneas subjected to an experimental PRK lesion. In some cases some interindividual variability could be observed due to the design of the experimental model. This is a limitation to consider, despite the statistical significance of the data. In a model of laser induced surgical lesions in the cornea, topical application of an RGTA (i.e. cacicol) could be involved in avoiding myofibroblast scarring formation and promoting nerve regeneration. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

Effect of piroxicam, metamizol, and S-adenosylmethionine in a murine model of experimental trichomoniasis

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Nogal-Ruiz J.J.

2005-03-01

Full Text Available Biological effects of piroxicam, metamizol, and S-adenosylmethionine (S-AMET have been tested in NMRI mice infected intraperitoneally with Trichomonas vaginalis. An intraperitoneal treatment during ten preinfection days with piroxicam (10 mg/Kg/day, or metamizol (275 mg/Kg/day, but not with S-AMET (17 mg/Kg/day induced a significant decrease of abdominal lesions and mortality, assessed by means of a pathogenicity index. The trichomonicidal activity of piroxicam, metamizol, and S-AMET was tested in vitro at the concentration of 300 μM, but found ineffective. These assays have shown the usefulness of the experimental trichomoniasis model for the study of the immunomodulating activity of synthetic drugs.

Litter materials and the incidence of carcass lesions in broilers chickens

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RG Garcia

2012-03-01

Full Text Available The aim of this study was to evaluate the effects of different litter materials on litter compaction, broiler feathering and the incidence of carcass lesions. In the experiment, 3240 one-day-old Ross® chicks were selected by sex and distributed according to a completely randomized experimental design in a 2 x 6 factorial arrangement (two sex and six litter materials. The following litter materials were used: wood shavings, rice husks, chopped Napier grass, 50% sugar cane bagasse plus 50% wood shavings, 50% sugar cane bagasse plus 50% rice husks, and pure sugar cane bagasse. Litter compaction was weekly assessed using a penetrometer. On days 21, 35 and 42 of the experimental period, feathering on the back and legs was scored according to a 0 - 10 scale. On day 42, birds were slaughtered and the presence of bruises, scratches and footpad lesions was recorded. Litter material had no effect on bird feathering. Carcass lesions (scratches, bruises and footpad lesions were influenced by the litter material evaluated. Birds reared on sugarcane bagasse and chopped Napier grass presented more scratches, bruises and footpad lesions than the others. Dermatitis was more evident in birds reared on sugarcane bagasse, chopped Napier grass and the combination of litter materials. It was found that males presented higher incidence of dermatitis and footpad lesions than females. Each litter material presented different compaction degrees, which increased along the experimental period. Sugarcane bagasse, chopped Napier grass and the combination of bedding materials presented the highest degree of compaction, compared with wood shavings and rice husks.

Establishment of a mathematical model for the influence of respiratory movement upon the position of an intrahepatic space-occupying lesion

International Nuclear Information System (INIS)

Yu Yonghua; Luo Limin; Li Baosheng; Yu Jinming; Liang Chaoqian; Zhao Yuehuan

2002-01-01

Objective: To investigate the extent of liver lesion shifting with respiration in an attempt to establish a relevant mathematical model. Methods: We measured breathing movements with B ultrasonography in 84 primary or metastatic liver tumors and defined the relation between the lesion shifting extent with age, sex, height, weight, lesion location and size analyzed with the SPSS statistic software. Results: The Z, X and Y breathing-axis motions were 1.029±0.321 cm (range: 0.6-1.9 cm), 0.301 ± 0.131 cm (range: 0.0-0.6 cm) and 0.387±0.130 cm (range: 0.2-0.7 cm), respectively. The movement-related factor analysis revealed that age, weight and (right lobe) lesion location presented a negative relationship but height, sex and lesion size presented a positive relationship for Z, Y and X breathing-axis motions. Their mathematical regression models were established as Z = -2.660 + 2.952 H-1.539 x 10 -2 W-3.928 x 10 -3 A; Y = -0. 926 + 0. 987 H-4.992 x 10 -3 W, and X = 0.507 + 7.629 x 10 -2 S-3.686 x 10 -3 W [H : height (m), W : weight (kg) A : age (year), S : sex(M:1, F: 0)]. The liver breathing movement was verified with the model in another 11 patients and the conformation rate was up to 91%. Conclusions: The impact of breathing movement on the location of intrahepatic lesion is mainly focused on the Z-axis motion. The practical accuracy in anticipating breathing movement with the mathematical model is so justified that the use of this model be recommended in stereotactic radiotherapy

Experimental investigation of factors affecting the absolute recovery coefficients in iodine-124 PET lesion imaging

International Nuclear Information System (INIS)

Jentzen, Walter

2010-01-01

The use of recovery coefficients (RCs) in 124 I PET lesion imaging is a simple method to correct the imaged activity concentration (AC) primarily for the partial-volume effect and, to a minor extent, for the prompt gamma coincidence effect. The aim of this phantom study was to experimentally investigate a number of various factors affecting the 124 I RCs. Three RC-based correction approaches were considered. These approaches differ with respect to the volume of interest (VOI) drawn, which determines the imaged AC and the RCs: a single voxel VOI containing the maximum value (maximum RC), a spherical VOI with a diameter of the scanner resolution (resolution RC) and a VOI equaling the physical object volume (isovolume RC). Measurements were performed using mainly a stand-alone PET scanner (EXACT HR + ) and a latest-generation PET/CT scanner (BIOGRAPH mCT). The RCs were determined using a cylindrical phantom containing spheres or rotational ellipsoids and were derived from images acquired with a reference acquisition protocol. For each type of RC, the influence of the following factors on the RC was assessed: object shape, background activity spill in and iterative image reconstruction parameters. To evaluate the robustness of the RC-based correction approaches, the percentage deviation between RC-corrected and true ACs was determined from images acquired with a clinical acquisition protocol of different AC regimes. The observed results of the shape and spill-in effects were compared with simulation data derived from a convolution-based model. The study demonstrated that the shape effect was negligible and, therefore, was in agreement with theoretical expectations. In contradiction to the simulation results, the observed spill-in effect was unexpectedly small. To avoid variations in the determination of RCs due to reconstruction parameter changes, image reconstruction with a pixel length of about one-third or less of the scanner resolution and an OSEM 1 x 32 algorithm

Gypenosides ameliorate memory deficits in MPTP-lesioned mouse model of Parkinson's disease treated with L-DOPA.

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Zhao, Ting Ting; Kim, Kyung Sook; Shin, Keon Sung; Park, Hyun Jin; Kim, Hyun Jeong; Lee, Kyung Eun; Lee, Myung Koo

2017-09-06

Previous studies have revealed that gypenosides (GPS) improve the symptoms of anxiety disorders in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned rat model of Parkinson's disease (PD). The present study aimed to investigate the effects of GPS on memory deficits in an MPTP-lesioned mouse model of PD treated with L-3,4-dihydroxyphenylalanine (L-DOPA). MPTP (30 mg/kg/day, 5 days)-lesioned mice were treated with GPS (50 mg/kg) and/or L-DOPA (10 and 25 mg/kg) for 21 days. After the final treatments, behavioral changes were assessed in all mice using passive avoidance and elevated plus-maze tests. We then evaluated the biochemical influences of GPS treatment on levels of tyrosine hydroxylase (TH), dopamine, N-methyl-D-aspartate (NMDA) receptors, extracellular signal-regulated kinase (ERK1/2), and cyclic AMP-response element binding protein (CREB) phosphorylation. MPTP-lesioned mice exhibited deficits associated with habit learning and spatial memory, which were further aggravated by treatment with L-DOPA (25 mg/kg). However, treatment with GPS (50 mg/kg) ameliorated memory deficits. Treatment with GPS (50 mg/kg) also improved L-DOPA (25 mg/kg)-treated MPTP lesion-induced decreases in retention latency on the passive avoidance test, as well as levels of TH-immunopositive cells and dopamine in the substantia nigra and striatum. GPS treatment also attenuated increases in retention transfer latency on the elevated plus-maze test and in NMDA receptor expression, as well as decreases in the phosphorylation of ERK1/2 and CREB in the hippocampus. Treatment with L-DOPA (10 mg/kg) also ameliorated deficits in habit learning and spatial memory in MPTP-lesioned mice, and this effect was further enhanced by treatment with GPS (50 mg/kg). GPS ameliorate deficits in habit learning and spatial memory by modulating the dopaminergic neuronal and N-methyl-D-aspartate receptor-mediated signaling systems in MPTP-lesioned mice treated with L-DOPA. GPS may serve as an adjuvant

Anti-inflammatory effects of rebamipide eyedrop administration on ocular lesions in a murine model of primary Sjögren's syndrome.

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Rieko Arakaki

Full Text Available Topical therapy is effective for dry eye, and its prolonged effects should help in maintaining the quality of life of patients with dry eye. We previously reported that the oral administration of rebamipide (Reb, a mucosal protective agent, had a potent therapeutic effect on autoimmune lesions in a murine model of Sjögren's syndrome (SS. However, the effects of topical treatment with Reb eyedrops on the ocular lesions in the murine model of SS are unknown.Reb eyedrops were administered to the murine model of SS aged 4-8 weeks four times daily. Inflammatory lesions of the extraorbital and intraorbital lacrimal glands and Harderian gland tissues were histologically evaluated. The direct effects of Reb on the lacrimal glands were analyzed using cultured lacrimal gland cells. Tear secretions of Reb-treated mice were significantly increased compared with those of untreated mice. In addition to the therapeutic effect of Reb treatment on keratoconjunctivitis, severe inflammatory lesions of intraorbital lacrimal gland tissues in this model of SS were resolved. The mRNA expression levels of IL-10 and mucin 5Ac in conjunctival tissues from Reb-treated mice was significantly increased compared with those of control mice. Moreover, lactoferrin production from lacrimal gland cells was restored by Reb treatment.Topical Reb administration had an anti-inflammatory effect on the ocular autoimmune lesions in the murine model of SS and a protective effect on the ocular surfaces.

Energy deposition and the formation of biologically significant lesions by accelerated ions

International Nuclear Information System (INIS)

Kiefer, J.

1985-01-01

The assumption that the number of biologically significant lesions depends only on the amount of of energy absorbed in a critical cellular site is not able to explain the increase of RBE with LET and leads to large discrepancies between predicted and measured inactivation cross sections in the LET range between 20 and 200 keV.μm -1 . It has, therefore, to be concluded that not only the amount of energy absorbed but also the spatial pattern of this deposition plays a decisive role. In the model presented it is postulated that two or more energy deposition events in nanometre sites are required for the formation of biologically significant lesions. This cooperative action has to take place in very short times so that only interactions within a single particle track contribute. The mathematical treatment will be outlined and qualitatively shown that the model is able to predict RBE-LET relationships. The calculations use a track structure model based on classical collision mechanics. It is compared with existing experimental results showing good agreement at least for higher particle energies. (author)

Lesion progression in post-treatment persistent endodontic lesions.

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Yu, Victoria Soo Hoon; Messer, Harold Henry; Shen, Liang; Yee, Robert; Hsu, Chin-ying Stephen

2012-10-01

Radiographic lesions related to root-filled teeth may persist for long periods after treatment and are considered to indicate failure of initial treatment. Persistent lesions are found in a proportion of cases, but information on lesion progression is lacking. This study examined the incidence of lesion improvement, remaining unchanged, and deterioration among persistent lesions in a group of patients recruited from a university-based clinic and identified potential predictors for lesion progression. Patients of a university clinic with persistent endodontic lesions at least 4 years since treatment and with original treatment radiographs available were recruited with informed consent. Data were obtained by interview and from dental records and clinical and radiographic examinations. Univariate and multivariate statistical analyses were carried out by using SPSS (version 19). One hundred fifty-one persistent lesions were identified in 114 patients. A majority of the lesions (107, 70.9%) received treatment between 4 and 5 years prior. Eighty-six lesions (57.0%) improved, 18 (11.9%) remained unchanged, and 47 (31.1%) deteriorated since treatment. Potential predictors for lesions that did not improve included recall lesion size, pain on biting at recall examination, history of a postobturation flare-up, and a non-ideal root-filling length (P < .05). Lesions that had persisted for a longer period appeared less likely to be improving (relative risk, 1.038; 95% confidence interval, 1.000-1.077). A specific time interval alone should not be used to conclude that a lesion will not resolve without intervention. This study identified several clinical factors that are associated with deteriorating persistent lesions, which should aid in identifying lesions that require further intervention. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Initial lung lesions in two calves experimentally infected with Haemophilus somnus

DEFF Research Database (Denmark)

Tegtmeier, Conny; Bloch, B.; Jensen, N.E.

1999-01-01

electron microscopy (TEM). Inoculation with H. somnus resulted in the development of acute pulmonary lesions within 3.5 h. H. somnus antigen was demonstrated only within the luminal spaces of the airways and in one area of bronchio-associated lymphoid tissue (BALT). As observed by TEM, the bacteria were...

Visual performance of pigeons following hippocampal lesions.

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Bingman, V P; Hodos, W

1992-11-15

The effect of hippocampal lesions on performance in two psychophysical measures of spatial vision (acuity and size-difference threshold) was examined in 7 pigeons. No difference between the preoperative and postoperative thresholds of the experimental birds was found. The visual performance of pigeons in the psychophysical tasks failed to reveal a role of the hippocampal formation in vision. The results argue strongly that the behavioral deficits found in pigeons with hippocampal lesions when tested in a variety of memory-related spatial tasks is not based on a defect in spatial vision but impaired spatial cognition.

The extent of adhesion induction through electrocoagulation and suturing in an experimental rat study.

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Wallwiener, Christian W; Kraemer, Bernhard; Wallwiener, Markus; Brochhausen, Christoph; Isaacson, Keith B; Rajab, Taufiek K

2010-03-01

To investigate the effect of three types of peritoneal trauma occurring during surgery (high-frequency bipolar current, suturing, and mechanical damage) on postoperative adhesion formation in a rodent animal model. Randomized, controlled experimental trial in an in vitro animal model. Laboratory facilities of a university department of obstetrics and gynecology. Thirty-five female Wistar rats. Bilateral experimental lesions were created on the abdominal wall in every animal. The effect of minimal electrocoagulation was examined by creating lesions (n = 14) through sweeps of a bipolar forceps with a duration of 1 second and standardized pressure. For extensive electrocoagulation standardized lesions (n = 14) were created using sweeps of a duration of 3 seconds and three times more pressure. For mechanical trauma, standardized lesions (n = 14) were created by denuding the peritoneum mechanically. To study the additive effect of suturing, experimental lesions were created by suturing plus minimal electrocoagulation (n = 14) or mechanical denuding (n = 14). Adhesion incidence, quantity, and quality of the resulting adhesions were scored 14 days postoperatively. Adhesions were studied histopathologically. Mechanical denuding of the peritoneum did not result in adhesion formation. After minimal electrocoagulation, mean adhesion quantity of the traumatized area averaged 0%. This contrasted with extensive electrocoagulation, where there was 50% adhesion. Additional suturing increased mean adhesion quantity to 73% and 64% for superficial electrocoagulation and mechanical denuding, respectively. We conclude that superficial trauma limited mostly to the parietal peritoneum may be a negligible factor in adhesion formation in this model. This appears to be irrespective of the mode of trauma. However, additional trauma to the underlying tissues, either by deeper electrocoagulation or suturing, leads to significantly increased adhesion formation. These data also show that there

Injury Based on Its Study in Experimental Models

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M. Mendes-Braz

2012-01-01

Full Text Available The present review focuses on the numerous experimental models used to study the complexity of hepatic ischemia/reperfusion (I/R injury. Although experimental models of hepatic I/R injury represent a compromise between the clinical reality and experimental simplification, the clinical transfer of experimental results is problematic because of anatomical and physiological differences and the inevitable simplification of experimental work. In this review, the strengths and limitations of the various models of hepatic I/R are discussed. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. We also attempt to highlight the fact that the mechanisms responsible for hepatic I/R injury depend on the experimental model used, and therefore the therapeutic strategies also differ according to the model used. Thus, the choice of model must therefore be adapted to the clinical question being answered.

Modeling of Experimental Adsorption Isotherm Data

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Xunjun Chen

2015-01-01

Full Text Available Adsorption is considered to be one of the most effective technologies widely used in global environmental protection areas. Modeling of experimental adsorption isotherm data is an essential way for predicting the mechanisms of adsorption, which will lead to an improvement in the area of adsorption science. In this paper, we employed three isotherm models, namely: Langmuir, Freundlich, and Dubinin-Radushkevich to correlate four sets of experimental adsorption isotherm data, which were obtained by batch tests in lab. The linearized and non-linearized isotherm models were compared and discussed. In order to determine the best fit isotherm model, the correlation coefficient (r2 and standard errors (S.E. for each parameter were used to evaluate the data. The modeling results showed that non-linear Langmuir model could fit the data better than others, with relatively higher r2 values and smaller S.E. The linear Langmuir model had the highest value of r2, however, the maximum adsorption capacities estimated from linear Langmuir model were deviated from the experimental data.

Omega-3 polyunsaturated Fatty acids suppress the cystic lesion formation of peritoneal endometriosis in transgenic mouse models.

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Kensuke Tomio

Full Text Available Omega-3 polyunsaturated fatty acids (omega-3 PUFAs play a role in controlling pathological inflammatory reactions. Endometriosis is characterized by the presence of endometrial tissue on the peritoneum and an exaggerated inflammatory environment around ectopic tissues. Here peritoneal endometriosis was reproduced using a mouse model in which murine endometrial fragments were inoculated into the peritoneal cavity of mice. Fat-1 mice, in which omega-6 can be converted to omega-3 PUFAs, or wild type mice, in which it cannot, were used for the endometriosis model to address the actions of omega-3 PUFAs on the development of endometriotic lesions. The number and weight of cystic endometriotic lesions in fat-1 mice two weeks after inoculation were significantly less than half to those of controls. Mediator lipidomics revealed that cystic endometriotic lesions and peritoneal fluids were abundant in 12/15-hydroxyeicosapentaenoic acid (12/15-HEPE, derived from eicosapentaenoic acid (EPA, and their amount in fat-1 mice was significantly larger than that in controls. 12/15-Lipoxygenase (12/15-LOX-knockout (KO and control mice with or without EPA administration were assessed for the endometriosis model. EPA administration decreased the number of lesions in controls but not in 12/15-LOX-KO mice. The peritoneal fluids in EPA-fed 12/15-LOX-KO mice contained reduced levels of EPA metabolites such as 12/15-HEPE and EPA-derived resolvin E3 even after EPA administration. cDNA microarrays of endometriotic lesions revealed that Interleukin-6 (IL-6 expression in fat-1 mice was significantly lower than that in controls. These results suggest that both endogenous and exogenous EPA-derived PUFAs protect against the development of endometriosis through their anti-inflammatory effects and, in particular, the 12/15-LOX-pathway products of EPA may be key mediators to suppress endometriosis.

Omega-3 polyunsaturated Fatty acids suppress the cystic lesion formation of peritoneal endometriosis in transgenic mouse models.

Science.gov (United States)

Tomio, Kensuke; Kawana, Kei; Taguchi, Ayumi; Isobe, Yosuke; Iwamoto, Ryo; Yamashita, Aki; Kojima, Satoko; Mori, Mayuyo; Nagamatsu, Takeshi; Arimoto, Takahide; Oda, Katsutoshi; Osuga, Yutaka; Taketani, Yuji; Kang, Jing X; Arai, Hiroyuki; Arita, Makoto; Kozuma, Shiro; Fujii, Tomoyuki

2013-01-01

Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) play a role in controlling pathological inflammatory reactions. Endometriosis is characterized by the presence of endometrial tissue on the peritoneum and an exaggerated inflammatory environment around ectopic tissues. Here peritoneal endometriosis was reproduced using a mouse model in which murine endometrial fragments were inoculated into the peritoneal cavity of mice. Fat-1 mice, in which omega-6 can be converted to omega-3 PUFAs, or wild type mice, in which it cannot, were used for the endometriosis model to address the actions of omega-3 PUFAs on the development of endometriotic lesions. The number and weight of cystic endometriotic lesions in fat-1 mice two weeks after inoculation were significantly less than half to those of controls. Mediator lipidomics revealed that cystic endometriotic lesions and peritoneal fluids were abundant in 12/15-hydroxyeicosapentaenoic acid (12/15-HEPE), derived from eicosapentaenoic acid (EPA), and their amount in fat-1 mice was significantly larger than that in controls. 12/15-Lipoxygenase (12/15-LOX)-knockout (KO) and control mice with or without EPA administration were assessed for the endometriosis model. EPA administration decreased the number of lesions in controls but not in 12/15-LOX-KO mice. The peritoneal fluids in EPA-fed 12/15-LOX-KO mice contained reduced levels of EPA metabolites such as 12/15-HEPE and EPA-derived resolvin E3 even after EPA administration. cDNA microarrays of endometriotic lesions revealed that Interleukin-6 (IL-6) expression in fat-1 mice was significantly lower than that in controls. These results suggest that both endogenous and exogenous EPA-derived PUFAs protect against the development of endometriosis through their anti-inflammatory effects and, in particular, the 12/15-LOX-pathway products of EPA may be key mediators to suppress endometriosis.

Lesion removal and lesion addition algorithms in lung volumetric data sets for perception studies

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Madsen, Mark T.; Berbaum, Kevin S.; Ellingson, Andrew; Thompson, Brad H.; Mullan, Brian F.

2006-03-01

Image perception studies of medical images provide important information about how radiologists interpret images and insights for reducing reading errors. In the past, perception studies have been difficult to perform using clinical imaging studies because of the problems associated with obtaining images demonstrating proven abnormalities and appropriate normal control images. We developed and evaluated interactive software that allows the seamless removal of abnormal areas from CT lung image sets. We have also developed interactive software for capturing lung lesions in a database where they can be added to lung CT studies. The efficacy of the software to remove abnormal areas of lung CT studies was evaluated psychophysically by having radiologists select the one altered image from a display of four. The software for adding lesions was evaluated by having radiologists classify displayed CT slices with lesions as real or artificial scaled to 3 levels of confidence. The results of these experiments demonstrated that the radiologist had difficulty in distinguishing the raw clinical images from those that had been altered. We conclude that this software can be used to create experimental normal control and "proven" lesion data sets for volumetric CT of the lung fields. We also note that this software can be easily adapted to work with other tissue besides lung and that it can be adapted to other digital imaging modalities.

Effect of rotary or manual instrumentation, with or without a calcium hydroxide/1% chlorhexidine intracanal dressing, on the healing of experimentally induced chronic periapical lesions.

Science.gov (United States)

De Rossi, Andiara; Silva, Léa A B; Leonardo, Mario R; Rocha, Lenaldo B; Rossi, Marcos A

2005-05-01

To evaluate the healing of experimentally induced chronic periapical lesions in dogs at 30, 75, and 120 days after root canal instrumentation with rotary NiTi files or manual K-files, with or without a calcium hydroxide/1% chlorhexidine paste intracanal dressing. The second, third, and fourth mandibular premolars and the second and third maxillary premolars of 5 dogs (12 to 18 months of age, weighing 8 to 15 kg) were selected for treatment (a total of 82 root canals). After pulp removal, the root canals were left exposed to the oral cavity for 7 days to allow microbial contamination, after which the root canals were sealed with ZOE cement until periapical lesions were confirmed with radiography. Group I and II teeth were instrumented with manual K-files using the crown-down technique. In group III and IV teeth, NiTi rotary files were used. The apical delta was perforated by using #20 to #30 K-files at the length of the tooth, thus creating a standardized apical opening. The apical stop was enlarged to size 70, with 2.5% sodium hypochlorite irrigation at each file change. Teeth in groups II and IV were dressed with calcium hydroxide (Ca(OH) 2 )/1% chlorhexidine (CHX) paste for 15 days before root filling. Group I and III teeth did not receive an intracanal dressing. The access openings of the teeth were permanently restored with silver amalgam condensed on a glass ionomer cement base. Pairs of standardized periapical radiographs were taken at the beginning of the treatment (0 days) and at 30, 75, and 120 days after filling. There was no significant difference in the rate of radiographic healing of the periapical lesions between manual and rotary instrumentation. Radiographs taken at 120 days showed that the treatment with Ca(OH) 2 /1% CHX paste resulted in a significant reduction in mean size of the periapical lesions in comparison to single-session treatment. These findings were also true for histologic observations. The findings support the hypothesis that

Experimental models of brain ischemia: a review of techniques, magnetic resonance imaging and investigational cell-based therapies

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Alessandra eCanazza

2014-02-01

Full Text Available Stroke continues to be a significant cause of death and disability worldwide. Although major advances have been made in the past decades in prevention, treatment and rehabilitation, enormous challenges remain in the way of translating new therapeutic approaches from bench to bedside. Thrombolysis, while routinely used for ischemic stroke, is only a viable option within a narrow time window. Recently, progress in stem cell biology has opened up avenues to therapeutic strategies aimed at supporting and replacing neural cells in infarcted areas. Realistic experimental animal models are crucial to understand the mechanisms of neuronal survival following ischemic brain injury and to develop therapeutic interventions. Current studies on experimental stroke therapies evaluate the efficiency of neuroprotective agents and cell-based approaches using primarily rodent models of permanent or transient focal cerebral ischemia. In parallel, advancements in imaging techniques permit better mapping of the spatial-temporal evolution of the lesioned cortex and its functional responses. This review provides a condensed conceptual review of the state of the art of this field, from models and magnetic resonance imaging techniques through to stem cell therapies.

Tissue lesion created by HIFU in continuous scanning mode

Science.gov (United States)

Fan, Tingbo; Liu, Zhenbo; Zhang, Dong

2012-09-01

The lesion formation was numerically and experimentally investigated by the continuous scanning mode. Simulations were presented based on the combination of Khokhlov-Zabolotskaya-Kuznetov (KZK) equation and bio-heat equation. Measurements were performed on porcine liver tissues using a 1.01 MHz single-element focused transducer at various acoustic powers, confirmed the predicted results. Controlling of the peak temperature and lesion by the scanning speed may be exploited for improvement of efficiency in HIFU therapy.

Tratamiento no quirúrgico de lesiones periapicales Non-surgical treatment of periapical lesions

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Pedro Pablo Ferro Benítez

2005-08-01

Full Text Available El tratamiento de dientes con lesiones periapicales crónicas ha sido estudiado por diferentes autores en el campo endodóntico. Basados en los resultados obtenidos en diferentes trabajos experimentales, nos propusimos realizar la presente investigación, tomando 30 dientes humanos que al momento de realizar el tratamiento pulpo-radicular mostraban presencia de lesiones periapicales con diámetros variables, por encima de los 5 mm . Se tuvieron en cuenta 2 grupos: en uno de ellos se les realizaron a los conductos radiculares rellenos temporales de pasta de hidróxido de calcio y agua destilada; en el otro grupo a estos conductos se les realizaron rellenos temporales con pasta de hidróxido de calcio, agua destilada y paramonoclorofenol alcanforado. Se evaluó la disminución de las lesiones periapicales en ambos grupos a los 3 y 6 meses de iniciado el tratamiento, sin que se observaran diferencias estadísticamente significativas. Igual ocurrió en la evaluación de la reparación ósea periapical a los 9 meses de iniciado el tratamiento. Con ambas técnicas los resultados fueron satisfactorios, lo que demuestra una participación activa del hidróxido de calcio en la reparación de las lesiones periapicales, independientemente de su asociación con el paramonoclorofenol alcanforado.The treatment of teeth with chronic periapical lesions has been studied by different authors in the endodontics field. Based on the results attained in different experimental works, we proposed ourselves to make the present research taking 30 human teeth that at the time of applying the pulpar radicular treatment presented periapical lesions with variable diameters over 5 mm. Two groups were taken into account: in one of them, the radicular ducts were temporarily filled up with calcium hydroxide paste and distilled water, whereas in the other one these ducts were filled up with calcium hydroxide paste, distilled water and camphorated paramonochlorophenol. The

Neuroprotective and behavioral efficacy of intravenous transplanted adipose stem cells in experimental Parkinsonian rat models

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Malihe Nakhaeifard

2016-02-01

Full Text Available Background: Parkinson's disease is a deficiency of dopamine in the striatum, characterized by bradykinesis, rigidity and resting tremor. Adipose tissue-Derived Stem Cells (ADSCs have many advantages for cell therapy because of the easy availability and pluripotency without ethical problems. In this research, the effects of ADSCs transplantation on motor impairment of rat Parkinsonian models were evaluated. Materials and Methods: Parkinson model was constructed by the unilateral lesion of striatum of male Wistar rats using 20µg of 6-hydroxydopamine (6-OHDA as lesion group. Cell and α-MEM (α-minimal essential medium groups were lesioned animals that received intravenous injection of 3×106 cells suspended in medium and medium repectively. All rats were evaluated behaviorally with rotarod and apomorphine-induced rotation tests, at 4 and 8 weeks after cell transplantation. Results: Lesion and α-MEM groups showed increased contralateral turns while cell group significantly ameliorated both in rotarod and apomorphine-induced rotation tests. There was a significant difference of contralateral turns between cell and lesioned groups at 8 weeks after transplantation. Lesioned rats showed significant decrease of staying on the rod as compared to control, but in cell group there was a significant increase in comparision with the lesioned animals. Conclusion: ADSCs injected intravenously promote functional recovery in Parkinsonian rats.

Detection of oral early cancerous lesion by using polarization-sensitive optical coherence tomography: mice model

Science.gov (United States)

Lee, Hong-Yi; Chen, Ping-Hsien; Lee, Tzu-Han; Chang, Kuo-Wei; Kuo, Wen-Chuan

2018-02-01

Oral cancer is the 11th most common cancer worldwide, especially in a male adult. The median age of death in oral cancer was 55 years, 10-20 years earlier than other cancers. Presently, oral cancer is often found in late stage, because the lesion is often flat in early stage and is difficult to diagnose under traditional white light imaging. The only definitive method for determining cancer is an invasive biopsy and then using histology examination. How to detect precancerous lesions or early malignant lesions is an important issue for improving prognosis of oral cancer. Optical coherence tomography (OCT) is a new optical tool for diagnosing early malignant lesions in the skin or gastrointestinal tract recently. Here we report a new method for detecting precancerous or early malignant oral lesions by using swept source polarization-sensitive optical coherence tomography (PS-OCT) with center-wavelength 1310 nm, bandwidth 110 nm and 100 kHz swept rate. We used all single-mode fiber design to detect the change of birefringence information in the epithelium structure. This system has an advantage that enables measurement of backscattered intensity and birefringence simultaneously with only one A-scan per transverse location. In preliminary result, we computed the slope of the every A-scan signal in tissue part using a linear-curve fitting in backscattered intensity and birefringence on the enface. In this research, we used an oral cancer mice model for observing the change of structure and birefringence properties in different stages of oral cancer mice. We presented the parametric enface imaging that can detect the early oral malignant lesions.

Histomorphological spetrum of breast lesions.

Science.gov (United States)

Parajuli, S; Koirala, U; Khatri, R; Acharya, L; Suwal, A

2011-04-01

Cancer of the breast is the second most common cause of cancer in women. Mass in the breast, whether benign or malignant is a cause of anxiety to the patients and the family members. All breast lumps are considered to be carcinomas until proved otherwise and are the causes of concern both for the patient and surgeon. This is a retrospective study conducted in Kathmandu Model Hospital for a total duration of three years from August 2007 to August 2010. 114 sample of breast tissue sent for histopathology were studied. Peak incidence of benign lesion was in between 21-30 years and malignant lesions in between 31-50 years. No breast lesions were seen in the first decade of life. Cancer of the breast was seen in 12.28% of cases. Fibroadenoma and fibrocystic disease were the commonest benign lesion and infiltrating ductal carcinoma was the commonest malignant lesion. Specimens from 10 male breasts were received. Gynaecomastia was the most common lesion encountered in males. Infiltrating ductal carcinoma was seen in a 70 year old male. Breast cancer is one of the commonest causes of breast lump particularly in women and is growing public health problem in Nepal.

The cytolethal distending toxin of Haemophilus ducreyi aggravates dermal lesions in a rabbit model of chancroid.

Science.gov (United States)

Wising, Catharina; Mölne, Lena; Jonsson, Ing-Marie; Ahlman, Karin; Lagergård, Teresa

2005-05-01

Haemophilus ducreyi, the etiologic agent of the sexually transmitted disease chancroid, produces a cytolethal distending toxin (HdCDT) that inhibits cultured cell proliferation, leading to cell death. A rabbit model of dermal infection was used to investigate the roles of H. ducreyi bacteria and HdCDT in the development, clinical appearance, and persistence of infection. A non-toxin producing H. ducreyi strain, and for comparison purposes a non-capsulated Haemophilus influenzae strain, were inoculated intradermally, with and without co-administration of purified HdCDT. Co-administration of HdCDT resulted in significant aggravation of H. ducreyi-induced inflammatory lesions, and development of ulcers in rabbit skin. Less pronounced inflammatory lesions and lack of epithelial eruption were observed after inoculation with H. influenzae. Histopathological sections of the H. ducreyi-induced lesions, in both the presence and absence of HdCDT, showed dense infiltrates of the same type inflammatory cells, with the exception of a prominent endothelial cell proliferation noted in sections from lesions caused by H. ducreyi and toxin. Signs of chronic inflammation with involvement of T cells, macrophages, eosinophils, and granuloma formation were observed after H. ducreyi inoculation both with and without toxin. In conclusion, H. ducreyi causes a pronounced, chronic inflammation with involvement of T cells and macrophages, and in combination with HdCDT production of ulcers in the rabbit model. These pathogenic mechanisms may promote the development and persistence of chancroid ulcers.

Developing Phenomena Models from Experimental Data

DEFF Research Database (Denmark)

Kristensen, Niels Rode; Madsen, Henrik; Jørgensen, Sten Bay

2003-01-01

A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

Developing Phenomena Models from Experimental Data

DEFF Research Database (Denmark)

A systematic approach for developing phenomena models from experimental data is presented. The approach is based on integrated application of stochastic differential equation (SDE) modelling and multivariate nonparametric regression, and it is shown how these techniques can be used to uncover...... unknown functionality behind various phenomena in first engineering principles models using experimental data. The proposed modelling approach has significant application potential, e.g. for determining unknown reaction kinetics in both chemical and biological processes. To illustrate the performance...... of the approach, a case study is presented, which shows how an appropriate phenomena model for the growth rate of biomass in a fed-batch bioreactor can be inferred from data....

An Improved Mouse Model of Atopic Dermatitis and Suppression of Skin Lesions by an Inhibitor of Tec Family Kinases

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Yuko Kawakami

2007-01-01

Conclusions: We established a highly efficient, highly reproducible protocol to induce skin lesions in NC/Nga mice and successfully applied it to show the efficacy of terreic acid in treating skin lesions. This mouse model of atopic dermatitis will be useful to study the pathogenetic processes of atopic dermatitis and to evaluate the efficacy of drug candidates.

Application of the diffusion kurtosis model for the study of breast lesions

International Nuclear Information System (INIS)

Nogueira, Luisa; Brandao, Sofia; Loureiro, Joana; Matos, Eduarda; Nunes, Rita Gouveia; Ferreira, Hugo Alexandre; Ramos, Isabel

2014-01-01

To evaluate diffusion-weighted imaging (DWI) and diffusion kurtosis imaging (DKI) in the differentiation and characterisation of breast lesions. Thirty-six women underwent breast magnetic resonance imaging (MRI) including a DWI sequence with multiple b-values (50-3,000 s/mm 2 ). Mean values for apparent diffusion coefficient (ADC), mean diffusivity (MD) and mean kurtosis (MK) were calculated by lesion type and histological subtype. Differences and correlation between parameters were determined. Forty-four lesions were found. There were significant differences between benign and malignant lesions for all parameters (ADC, p = 0.017; MD, p = 0.028; MK, p = 0.017). ADC and MD were higher for benign (1.96 ± 0.41 x 10 -3 and 2.17 ± 0.42 x 10 -3 mm 2 /s, respectively) than for malignant lesions (1.33 ± 0.18 x 10 -3 and 1.52 ± 0.50 x 10 -3 mm 2 /s). MK was higher for malignant (0.61 ± 0.27) than benign lesions (0.37 ± 0.18). We found differences between invasive ductal carcinoma (IDC) and fibroadenoma (FA) for all parameters (ADC, MD and MK): p = 0.016, 0.022 and 0.016, respectively. FA and fibrocystic change (FC) showed differences only in MK (p = 0.016). Diffusion in breast lesions follows a non-Gaussian distribution. MK enables differentiation and characterisation of breast lesions, providing new insights into microstructural complexity. To confirm these results, further investigation in a broader sample should be performed. (orig.)

Application of the diffusion kurtosis model for the study of breast lesions

Energy Technology Data Exchange (ETDEWEB)

Nogueira, Luisa [School of Health Technology of Porto/Polytechnic Institute of Porto (ESTSP/IPP), Department of Radiology, Vila Nova de Gaia (Portugal); Brandao, Sofia; Loureiro, Joana [Hospital de Sao Joao, MRI Unit, Department of Radiology, Porto (Portugal); Matos, Eduarda [University of Porto, Department of Health Community, Institute of Biomedical Sciences Abel Salazar (ICBAS), Porto (Portugal); Nunes, Rita Gouveia; Ferreira, Hugo Alexandre [University of Lisbon, Institute of Biophysics and Biomedical Engineering (IBEB), Faculty of Sciences, Lisboa (Portugal); Ramos, Isabel [Hospital de Sao Joao/Faculty of Medicine of Porto University (FMUP), Head Department of Radiology, Porto (Portugal)

2014-06-15

To evaluate diffusion-weighted imaging (DWI) and diffusion kurtosis imaging (DKI) in the differentiation and characterisation of breast lesions. Thirty-six women underwent breast magnetic resonance imaging (MRI) including a DWI sequence with multiple b-values (50-3,000 s/mm{sup 2}). Mean values for apparent diffusion coefficient (ADC), mean diffusivity (MD) and mean kurtosis (MK) were calculated by lesion type and histological subtype. Differences and correlation between parameters were determined. Forty-four lesions were found. There were significant differences between benign and malignant lesions for all parameters (ADC, p = 0.017; MD, p = 0.028; MK, p = 0.017). ADC and MD were higher for benign (1.96 ± 0.41 x 10{sup -3} and 2.17 ± 0.42 x 10{sup -3} mm{sup 2}/s, respectively) than for malignant lesions (1.33 ± 0.18 x 10{sup -3} and 1.52 ± 0.50 x 10{sup -3} mm{sup 2}/s). MK was higher for malignant (0.61 ± 0.27) than benign lesions (0.37 ± 0.18). We found differences between invasive ductal carcinoma (IDC) and fibroadenoma (FA) for all parameters (ADC, MD and MK): p = 0.016, 0.022 and 0.016, respectively. FA and fibrocystic change (FC) showed differences only in MK (p = 0.016). Diffusion in breast lesions follows a non-Gaussian distribution. MK enables differentiation and characterisation of breast lesions, providing new insights into microstructural complexity. To confirm these results, further investigation in a broader sample should be performed. (orig.)

PEMFC modeling and experimental validation

Energy Technology Data Exchange (ETDEWEB)

Vargas, J.V.C. [Federal University of Parana (UFPR), Curitiba, PR (Brazil). Dept. of Mechanical Engineering], E-mail: jvargas@demec.ufpr.br; Ordonez, J.C.; Martins, L.S. [Florida State University, Tallahassee, FL (United States). Center for Advanced Power Systems], Emails: ordonez@caps.fsu.edu, martins@caps.fsu.edu

2009-07-01

In this paper, a simplified and comprehensive PEMFC mathematical model introduced in previous studies is experimentally validated. Numerical results are obtained for an existing set of commercial unit PEM fuel cells. The model accounts for pressure drops in the gas channels, and for temperature gradients with respect to space in the flow direction, that are investigated by direct infrared imaging, showing that even at low current operation such gradients are present in fuel cell operation, and therefore should be considered by a PEMFC model, since large coolant flow rates are limited due to induced high pressure drops in the cooling channels. The computed polarization and power curves are directly compared to the experimentally measured ones with good qualitative and quantitative agreement. The combination of accuracy and low computational time allow for the future utilization of the model as a reliable tool for PEMFC simulation, control, design and optimization purposes. (author)

Anti-fibrin antibody binding in valvular vegetations and kidney lesions during experimental endocarditis.

Science.gov (United States)

Yokota, M; Basi, D L; Herzberg, M C; Meyer, M W

2001-01-01

In Streptococcus sanguinis (sanguis) induced experimental endocarditis, we sought evidence that the development of aortic valvular vegetation depends on the availability of fibrin. Endocarditis was induced in New Zealand white rabbits by catheter placement into the left ventricle and inoculation of the bacteria. Fibrin was localized in the developing vegetation with 99mTechnetium (Tc)-labeled anti-fibrin antibody one or three days later. When rabbit anti-fibrin antibody was given intravenously on day 1, the mass of aortic valvular vegetation was significantly reduced at day 3; infusion of non-specific rabbit IgG showed no effect. The 99mTc-labeled anti-fibrin antibody also labeled kidneys that showed macroscopic subcapsular hemorrhage. To learn if the deposition of fibrin in the kidneys was a consequence of endocarditis required a comparison of farm-bred and specific pathogen-free rabbits before and after the induction of endocarditis. Before induction, the kidneys of farm-bred rabbits were labeled, but specific pathogen-free rabbits were free of labeling and signs of macroscopic hemorrhage. After 3 days of endocarditis, kidneys of 10 of 14 specific pathogen-free rabbits labeled with 99mTc-labeled anti-fibrin antibody and showed hemorrhage. Kidney lesions were suggested to be a frequent sequellae of S. sanguinis infective endocarditis. For the first time, fibrin was shown to be required for the continued development of aortic valvular vegetations.

Detection of questionable occlusal carious lesions using an electrical bioimpedance method with fractional electrical model

Energy Technology Data Exchange (ETDEWEB)

Morais, A. P. [Biomedical Engineering Program, COPPE, Rio de Janeiro (Brazil); Salgado de Oliveira University, Marechal Deodoro Street, 217 – Centro, Niterói, Rio de Janeiro (Brazil); Pino, A. V. [Biomedical Engineering Program, COPPE, Rio de Janeiro (Brazil); Souza, M. N. [Biomedical Engineering Program, COPPE, Rio de Janeiro (Brazil); Electronics Department at Polytechnic School, Federal University of Rio de Janeiro, Centro de Tecnologia Bloco H sala 217, Ilha do Fundão, Rio de Janeiro (Brazil)

2016-08-15

This in vitro study evaluated the diagnostic performance of an alternative electric bioimpedance spectroscopy technique (BIS-STEP) detect questionable occlusal carious lesions. Six specialists carried out the visual (V), radiography (R), and combined (VR) exams of 57 sound or non-cavitated occlusal carious lesion teeth classifying the occlusal surfaces in sound surface (H), enamel caries (EC), and dentinal caries (DC). Measurements were based on the current response to a step voltage excitation (BIS-STEP). A fractional electrical model was used to predict the current response in the time domain and to estimate the model parameters: Rs and Rp (resistive parameters), and C and α (fractional parameters). Histological analysis showed caries prevalence of 33.3% being 15.8% hidden caries. Combined examination obtained the best traditional diagnostic results with specificity = 59.0%, sensitivity = 70.9%, and accuracy = 60.8%. There were statistically significant differences in bioimpedance parameters between the H and EC groups (p = 0.016) and between the H and DC groups (Rs, p = 0.006; Rp, p = 0.022, and α, p = 0.041). Using a suitable threshold for the Rs, we obtained specificity = 60.7%, sensitivity = 77.9%, accuracy = 73.2%, and 100% of detection for deep lesions. It can be concluded that BIS-STEP method could be an important tool to improve the detection and management of occlusal non-cavitated primary caries and pigmented sites.

Detection of questionable occlusal carious lesions using an electrical bioimpedance method with fractional electrical model

International Nuclear Information System (INIS)

Morais, A. P.; Pino, A. V.; Souza, M. N.

2016-01-01

This in vitro study evaluated the diagnostic performance of an alternative electric bioimpedance spectroscopy technique (BIS-STEP) detect questionable occlusal carious lesions. Six specialists carried out the visual (V), radiography (R), and combined (VR) exams of 57 sound or non-cavitated occlusal carious lesion teeth classifying the occlusal surfaces in sound surface (H), enamel caries (EC), and dentinal caries (DC). Measurements were based on the current response to a step voltage excitation (BIS-STEP). A fractional electrical model was used to predict the current response in the time domain and to estimate the model parameters: Rs and Rp (resistive parameters), and C and α (fractional parameters). Histological analysis showed caries prevalence of 33.3% being 15.8% hidden caries. Combined examination obtained the best traditional diagnostic results with specificity = 59.0%, sensitivity = 70.9%, and accuracy = 60.8%. There were statistically significant differences in bioimpedance parameters between the H and EC groups (p = 0.016) and between the H and DC groups (Rs, p = 0.006; Rp, p = 0.022, and α, p = 0.041). Using a suitable threshold for the Rs, we obtained specificity = 60.7%, sensitivity = 77.9%, accuracy = 73.2%, and 100% of detection for deep lesions. It can be concluded that BIS-STEP method could be an important tool to improve the detection and management of occlusal non-cavitated primary caries and pigmented sites.

Accuracy of the detection of infratentorial stroke lesions using perfusion CT: an experimenter-blinded study

International Nuclear Information System (INIS)

Lee, In Hyouk; Kim, Myung Soon; Kim, Young Ju; Lee, Myeong Sub; You, Joshua H.; Lee, Ji Yong; Whang, Kum

2010-01-01

Although perfusion CT (PCT) for the detection of supratentorial stroke is well established, there is a dearth of evidence of its effectiveness in the detection of infratentorial stroke. Hence, this study compared sensitivity, specificity, and accuracy of PCT maps between infratentorial and supratentorial stroke lesions. One hundred patients with acute stroke who had successfully undergone near whole-brain PCT with the toggling table technique and follow-up MRI were included. Wilcoxon Mann-Whitney test was performed at P 0.01 in all PCT maps) between supratentorial and infratentorial stroke. Also, there was no remarkable difference in both sensitivity and specificity of PCT maps. This was the first study to investigate the accuracy of PCT with the toggling table technique in detection of infratentorial stroke lesions. Clinically, PCT is highly reliable and accurate in detecting infratentorial stroke lesions. (orig.)

Skin Lesion Analysis towards Melanoma Detection Using Deep Learning Network

Science.gov (United States)

2018-01-01

Skin lesions are a severe disease globally. Early detection of melanoma in dermoscopy images significantly increases the survival rate. However, the accurate recognition of melanoma is extremely challenging due to the following reasons: low contrast between lesions and skin, visual similarity between melanoma and non-melanoma lesions, etc. Hence, reliable automatic detection of skin tumors is very useful to increase the accuracy and efficiency of pathologists. In this paper, we proposed two deep learning methods to address three main tasks emerging in the area of skin lesion image processing, i.e., lesion segmentation (task 1), lesion dermoscopic feature extraction (task 2) and lesion classification (task 3). A deep learning framework consisting of two fully convolutional residual networks (FCRN) is proposed to simultaneously produce the segmentation result and the coarse classification result. A lesion index calculation unit (LICU) is developed to refine the coarse classification results by calculating the distance heat-map. A straight-forward CNN is proposed for the dermoscopic feature extraction task. The proposed deep learning frameworks were evaluated on the ISIC 2017 dataset. Experimental results show the promising accuracies of our frameworks, i.e., 0.753 for task 1, 0.848 for task 2 and 0.912 for task 3 were achieved. PMID:29439500

Skin Lesion Analysis towards Melanoma Detection Using Deep Learning Network

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Yuexiang Li

2018-02-01

Full Text Available Skin lesions are a severe disease globally. Early detection of melanoma in dermoscopy images significantly increases the survival rate. However, the accurate recognition of melanoma is extremely challenging due to the following reasons: low contrast between lesions and skin, visual similarity between melanoma and non-melanoma lesions, etc. Hence, reliable automatic detection of skin tumors is very useful to increase the accuracy and efficiency of pathologists. In this paper, we proposed two deep learning methods to address three main tasks emerging in the area of skin lesion image processing, i.e., lesion segmentation (task 1, lesion dermoscopic feature extraction (task 2 and lesion classification (task 3. A deep learning framework consisting of two fully convolutional residual networks (FCRN is proposed to simultaneously produce the segmentation result and the coarse classification result. A lesion index calculation unit (LICU is developed to refine the coarse classification results by calculating the distance heat-map. A straight-forward CNN is proposed for the dermoscopic feature extraction task. The proposed deep learning frameworks were evaluated on the ISIC 2017 dataset. Experimental results show the promising accuracies of our frameworks, i.e., 0.753 for task 1, 0.848 for task 2 and 0.912 for task 3 were achieved.

Skin Lesion Analysis towards Melanoma Detection Using Deep Learning Network.

Science.gov (United States)

Li, Yuexiang; Shen, Linlin

2018-02-11

Skin lesions are a severe disease globally. Early detection of melanoma in dermoscopy images significantly increases the survival rate. However, the accurate recognition of melanoma is extremely challenging due to the following reasons: low contrast between lesions and skin, visual similarity between melanoma and non-melanoma lesions, etc. Hence, reliable automatic detection of skin tumors is very useful to increase the accuracy and efficiency of pathologists. In this paper, we proposed two deep learning methods to address three main tasks emerging in the area of skin lesion image processing, i.e., lesion segmentation (task 1), lesion dermoscopic feature extraction (task 2) and lesion classification (task 3). A deep learning framework consisting of two fully convolutional residual networks (FCRN) is proposed to simultaneously produce the segmentation result and the coarse classification result. A lesion index calculation unit (LICU) is developed to refine the coarse classification results by calculating the distance heat-map. A straight-forward CNN is proposed for the dermoscopic feature extraction task. The proposed deep learning frameworks were evaluated on the ISIC 2017 dataset. Experimental results show the promising accuracies of our frameworks, i.e., 0.753 for task 1, 0.848 for task 2 and 0.912 for task 3 were achieved.

Experimental validation of a three-dimensional linear system model for breast tomosynthesis

International Nuclear Information System (INIS)

Zhao Bo; Zhou Jun; Hu Yuehoung; Mertelmeier, Thomas; Ludwig, Jasmina; Zhao Wei

2009-01-01

A three-dimensional (3D) linear model for digital breast tomosynthesis (DBT) was developed to investigate the effects of different imaging system parameters on the reconstructed image quality. In the present work, experimental validation of the model was performed on a prototype DBT system equipped with an amorphous selenium (a-Se) digital mammography detector and filtered backprojection (FBP) reconstruction methods. The detector can be operated in either full resolution with 85 μm pixel size or 2x1 pixel binning mode to reduce acquisition time. Twenty-five projection images were acquired with a nominal angular range of ±20 deg. The images were reconstructed using a slice thickness of 1 mm with 0.085x0.085 mm in-plane pixel dimension. The imaging performance was characterized by spatial frequency-dependent parameters including a 3D noise power spectrum (NPS) and in-plane modulation transfer function (MTF). Scatter-free uniform x-ray images were acquired at four different exposure levels for noise analysis. An aluminum (Al) edge phantom with 0.2 mm thickness was imaged to measure the in-plane presampling MTF. The measured in-plane MTF and 3D NPS were both in good agreement with the model. The dependence of DBT image quality on reconstruction filters was investigated. It was found that the slice thickness (ST) filter, a Hanning window to limit the high-frequency components in the slice thickness direction, reduces noise aliasing and improves 3D DQE. An ACR phantom was imaged to investigate the effects of angular range and detector operational modes on reconstructed image quality. It was found that increasing the angular range improves the MTF at low frequencies, resulting in better detection of large-area, low-contrast mass lesions in the phantom. There is a trade-off between noise and resolution for pixel binning and full resolution modes, and the choice of detector mode will depend on radiation dose and the targeted lesion.

Experimental validation of a three-dimensional linear system model for breast tomosynthesis

Energy Technology Data Exchange (ETDEWEB)

Zhao Bo; Zhou Jun; Hu Yuehoung; Mertelmeier, Thomas; Ludwig, Jasmina; Zhao Wei [Department of Radiology, State University of New York at Stony Brook, L-4 120 Health Sciences Center, Stony Brook, New York 11794-8460 (United States); Siemens AG Healthcare, Henkestrasse 127, D-91052 Erlangen (Germany); Department of Radiology, State University of New York at Stony Brook, L-4 120 Health Sciences Center, Stony Brook, New York 11794-8460 (United States)

2009-01-15

A three-dimensional (3D) linear model for digital breast tomosynthesis (DBT) was developed to investigate the effects of different imaging system parameters on the reconstructed image quality. In the present work, experimental validation of the model was performed on a prototype DBT system equipped with an amorphous selenium (a-Se) digital mammography detector and filtered backprojection (FBP) reconstruction methods. The detector can be operated in either full resolution with 85 {mu}m pixel size or 2x1 pixel binning mode to reduce acquisition time. Twenty-five projection images were acquired with a nominal angular range of {+-}20 deg. The images were reconstructed using a slice thickness of 1 mm with 0.085x0.085 mm in-plane pixel dimension. The imaging performance was characterized by spatial frequency-dependent parameters including a 3D noise power spectrum (NPS) and in-plane modulation transfer function (MTF). Scatter-free uniform x-ray images were acquired at four different exposure levels for noise analysis. An aluminum (Al) edge phantom with 0.2 mm thickness was imaged to measure the in-plane presampling MTF. The measured in-plane MTF and 3D NPS were both in good agreement with the model. The dependence of DBT image quality on reconstruction filters was investigated. It was found that the slice thickness (ST) filter, a Hanning window to limit the high-frequency components in the slice thickness direction, reduces noise aliasing and improves 3D DQE. An ACR phantom was imaged to investigate the effects of angular range and detector operational modes on reconstructed image quality. It was found that increasing the angular range improves the MTF at low frequencies, resulting in better detection of large-area, low-contrast mass lesions in the phantom. There is a trade-off between noise and resolution for pixel binning and full resolution modes, and the choice of detector mode will depend on radiation dose and the targeted lesion.

Platelet-rich plasma in orthopedic therapy: a comparative systematic review of clinical and experimental data in equine and human musculoskeletal lesions.

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Brossi, Patrícia M; Moreira, Juliana J; Machado, Thaís S L; Baccarin, Raquel Y A

2015-04-22

This systematic review aimed to present and critically appraise the available information on the efficacy of platelet rich plasma (PRP) in equine and human orthopedic therapeutics and to verify the influence of study design and methodology on the assumption of PRP's efficacy. We searched Medline, PubMed, Embase, Bireme and Google Scholar without restrictions until July 2013. Randomized trials, human cohort clinical studies or case series with a control group on the use of PRP in tendons, ligaments or articular lesions were included. Equine clinical studies on the same topics were included independently of their design. Experimental studies relevant to the clarification of PRP's effects and mechanisms of action in tissues of interest, conducted in any animal species, were selected. This review included 123 studies. PRP's beneficial effects were observed in 46.7% of the clinical studies, while the absence of positive effects was observed in 43.3%. Among experimental studies, 73% yielded positive results, and 7.9% yielded negative results. The most frequent flaws in the clinical trials' designs were the lack of a true placebo group, poor product characterization, insufficient blinding, small sampling, short follow-up periods, and adoption of poor outcome measures. The methods employed for PRP preparation and administration and the selected outcome measures varied greatly. Poor study design was a common feature of equine clinical trials. From studies in which PRP had beneficial effects, 67.8% had an overall high risk of bias. From the studies in which PRP failed to exhibit beneficial effects, 67.8% had an overall low risk of bias. Most experimental studies revealed positive effects of PRP. Although the majority of equine clinical studies yielded positive results, the human clinical trials' results failed to corroborate these findings. In both species, beneficial results were more frequently observed in studies with a high risk of bias. The use of PRP in musculoskeletal

A comparative study of 99mTc-HL91 and 99mTc-MIBI imaging in experimental tumor and inflammatory models

International Nuclear Information System (INIS)

Cao, W.; Zhang, X.Y.; An, R.

2002-01-01

Aim: 99m Tc-HL91 is a newly developed hypoxic imaging agent for ischemic myocardium and tumor imaging. 99m Tc-MIBI is one of imaging agent for mammary tumor imaging. The aim of this experiment is to evaluate the diagnostic value of 99m Tc-HL91 in detection of solid tumor in experimental tumor and inflammatory models, via comparative study with 99m Tc-MIBI. Material and Methods: HL91 kits was provided by China Nine Star Co. Three kinds of bearing solid neoplasm mice groups (bearing Ehrlich carcinoma mice, bearing H 22 carcinoma mice and bearing human ovarian COC 1 neoplasm nude mice) and two inflammatory model groups (chemical and bacterial inflammation) underwent static whole body planar images at 1 and 4 hours post injection of 99m Tc-HL91. Two kinds of bearing neoplasm mice groups (bearing Ehrlich carcinoma mice, bearing H 22 carcinoma mice) and two inflammatory model groups (chemical and bacterial inflammation) underwent static planar images post injection of 99m Tc-MIBI, at early phase (10∼20 minutes) and delayed phase (2 hrs). All of mice were sacrificed at 4 hrs. The tumors, or inflammatory lesions, blood and contralateral muscles were removed, weighed and the radioactivity was measured. Regions of interesting (ROIs) were drawn around tumor, inflammatory lesions and contralateral muscles in planar images, and the radioactivity ratios of target (tumor or inflammatory lesions)-to-blood (T/B), target-to-non target (contralateral muscles) i. e. T/NT was calculated. Results: Neoplasm can be clearly visible in planar images at 1hr and 4 hrs post injection of 99m Tc-HL91 in all tumor models. At same time inflammatory lesions cannot be seen clearly. Neoplasm can be seen in delayed phase in 99m Tc-MIBI groups, but not easy to distinguish them from inflammation. Conclusion: Compared with 99m Tc-MIBI imaging, 99m Tc-HL91 has much more diagnostic value in detection of solid neoplasm, and can distinguish neoplasm from inflammation

Intensity dependence of focused ultrasound lesion position

Science.gov (United States)

Meaney, Paul M.; Cahill, Mark D.; ter Haar, Gail R.

1998-04-01

Knowledge of the spatial distribution of intensity loss from an ultrasonic beam is critical to predicting lesion formation in focused ultrasound surgery. To date most models have used linear propagation models to predict the intensity profiles needed to compute the temporally varying temperature distributions. These can be used to compute thermal dose contours that can in turn be used to predict the extent of thermal damage. However, these simulations fail to adequately describe the abnormal lesion formation behavior observed for in vitro experiments in cases where the transducer drive levels are varied over a wide range. For these experiments, the extent of thermal damage has been observed to move significantly closer to the transducer with increasing transducer drive levels than would be predicted using linear propagation models. The simulations described herein, utilize the KZK (Khokhlov-Zabolotskaya-Kuznetsov) nonlinear propagation model with the parabolic approximation for highly focused ultrasound waves, to demonstrate that the positions of the peak intensity and the lesion do indeed move closer to the transducer. This illustrates that for accurate modeling of heating during FUS, nonlinear effects must be considered.

New experimental model for training in videosurgery Novo modelo experimental para treinamento em videocirurgia

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Danilo Malta Batista

2012-10-01

Full Text Available PURPOSE: To develop a new experimental model of lower cost for training in videosurgery. METHODS: This project was performed at the Nucleus of Experimental Surgery of the Bahiana School of Medicine and Public Health, based on previous models described in the literature and under the supervision of the full professor of Operative Technique and Experimental Surgery II. It was made a model cube-shaped, made of wood, with holes distributed in various locations, rubber stoppers for the holes and lined externally with carpet, and internally with laminate. RESULTS: The new experimental model is of low cost and reproduces quite faithfully several videosurgical procedures. CONCLUSION: Medical schools interested in the subject may adopt the new model for training in videosurgery without the need of high costs for making and using these models.OBJETIVO: Desenvolver um novo modelo experimental de baixo custo para treinamento em videocirurgia MÉTODOS: Este projeto foi conduzido no Núcleo de Cirurgia Experimental da Escola Bahiana de Medicina e Saúde Pública, baseado em modelos prévios descritos na literatura e sob a supervisão do professor titular de Técnica Operatória e Cirurgia Experimental II. Foi feito um modelo em formato de cubo, de madeira, com furos distribuídos em vários locais, tampas de borracha para os orifícios e forrado externamente com carpete e internamente com laminado. RESULTADOS: O novo modelo experimental desenvolvido é de baixo custo e reproduz de forma bastante fiel diversos procedimentos videocirúrgicos. CONCLUSÃO: Faculdades médicas interessadas no tema poderão adotar o novo modelo para o treinamento em videocirurgia sem que sejam necessários gastos elevados para a confecção e o uso desses modelos.

Heavy ion-induced lesions in DNA: A theoretical model for the initial induction of DNA strand breaks and chromatin breaks

International Nuclear Information System (INIS)

Schmidt, J.B.

1993-01-01

A theoretical model has been developed and used to calculate yields and spatial distributions of DNA strand breaks resulting from the interactions of heavy ions with chromatin in aqueous systems. The three dimensional spatial distribution of ionizing events has been modeled for charged particles as a function of charge and velocity. Chromatin has been modeled as a 30 nm diameter solenoid of nucleosomal DNA. The Monte Carlo methods used by Chatterjee et al. have been applied to DNA in a chromatin conformation. Refinements to their methods include: a combined treatment of primary and low energy (<2 keV) secondary electron interactions, an improved low energy delta ray model, and the combined simulation of direct energy deposition on the DNA and attack by diffusing hydroxyl radicals. Individual particle tracks are treated independently, which is assumed to be applicable to low fluence irradiations in which multiple particle effects are negligible. Single strand break cross section open-quotes hooksclose quotes seen in experiments at very high LET appear to be due to the collapsing radial extent of the track, as predicted in the open-quotes deep sieveclose quotes hypothesis proposed by Tobias et al. Spatial distributions of lesions produced by particles have been found to depend on chromatin structure. In the future, heavy ions may be used as a tool to probe the organization of DNA in chromatin. A Neyman A-binomial variation of the open-quotes cluster modelclose quotes for the distribution of chromatin breaks per irradiated cell has been theoretically tested. The model includes a treatment of the chromatin fragment detection technique's resolution, which places a limitation on the minimum size of fragments which can be detected. The model appears to fit some of the experimental data reasonably well. However, further experimental and theoretical refinements are desirable

Rehardening of caries-like lesions in root surfaces by saliva substitutes.

Science.gov (United States)

Turssi, Cecilia P; Lima, Renata Q V; Faraoni-Romano, Juliana J; Serra, Mônica C

2006-12-01

This study sought to evaluate whether root dentine caries-like lesions could be remineralised by saliva substitutes. Root dentine slabs (3 x 3 x 2 mm) were cut from bovine incisors, ground flat, polished and pre-tested for Knoop microhardness (KHN) at five locations spaced 500 microm apart and 500 microm from the left edge of each sectioned piece. After 60 out of the 100 slabs had been selected based upon their KHN values, specimens were coated with wax except for their outer surface. Specimens were then cycled through a highly cariogenic challenge model to induce caries-like lesions, whose formation was confirmed by KHN measurements located 500 microm from the right edge of the specimen. According to a randomised complete block design, the experimental units (n = 15) were exposed to 1.5 ml of saliva substitutes, based on either mucin (MC) or carboxymethylcellulose (CM), to natural human saliva (HS) or to 100% relative humidity (RH) over 20 days. Remineralisation was verified by KHN measurements located 1000 microm apart from the right edge of the specimen. Analysis of variance indicated a significant (p < 0.0001) difference among the KHN values attained by the carious root dentine after exposure to the remineralising agents. Tukey's test ascertained that remineralisation was greatest with MC, intermediate with CM and least with HS, but rehardening did not reach the pre-caries lesion formation values. Saliva substitutes may provide partial remineralisation to preformed caries-like lesions in root dentine.

BDNF levels are increased by aminoindan and rasagiline in a double lesion model of Parkinson׳s disease.

Science.gov (United States)

Ledreux, Aurélie; Boger, Heather A; Hinson, Vanessa K; Cantwell, Kelsey; Granholm, Ann-Charlotte

2016-01-15

The anti-Parkinsonian drug rasagiline is a selective, irreversible inhibitor of monoamine oxidase and is used in the treatment of Parkinson׳s disease (PD). Its postulated neuroprotective effects may be attributed to MAO inhibition, or to its propargylamine moiety. The major metabolite of rasagiline, aminoindan, has shown promising neuroprotective properties in vitro but there is a paucity of studies investigating in vivo effects of this compound. Therefore, we examined neuroprotective effects of rasagiline and its metabolite aminoindan in a double lesion model of PD. Male Fisher 344 rats received i.p. injections of the noradrenergic neurotoxin DSP-4 and intra-striatal stereotaxic microinjections of the dopamine neurotoxin 6-OHDA. Saline, rasagiline or aminoindan (3mg/kg/day s.c.) were delivered via Alzet minipumps for 4 weeks. Rats were then tested for spontaneous locomotion and a novel object recognition task. Following behavioral testing, brain tissue was processed for ELISA measurements of growth factors and immunohistochemistry. Double-lesioned rats treated with rasagiline or aminoindan had reduced behavioral deficits, both in motor and cognitive tasks compared to saline-treated double-lesioned rats. BDNF levels were significantly increased in the hippocampus and striatum of the rasagiline- and aminoindan-lesioned groups compared to the saline-treated lesioned group. Double-lesioned rats treated with rasagiline or aminoindan exhibited a sparing in the mitochondrial marker Hsp60, suggesting mitochondrial involvement in neuroprotection. Tyrosine hydroxylase (TH) immunohistochemistry revealed a sparing of TH-immunoreactive terminals in double-lesioned rats treated with rasagiline or aminoindan in the striatum, hippocampus, and substantia nigra. These data provide evidence of neuroprotection by aminoindan and rasagiline via their ability to enhance BDNF levels. Published by Elsevier B.V.

Paraquat poisoning: an experimental model of dose-dependent acute lung injury due to surfactant dysfunction

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M.F.R. Silva

1998-03-01

Full Text Available Since the most characteristic feature of paraquat poisoning is lung damage, a prospective controlled study was performed on excised rat lungs in order to estimate the intensity of lesion after different doses. Twenty-five male, 2-3-month-old non-SPF Wistar rats, divided into 5 groups, received paraquat dichloride in a single intraperitoneal injection (0, 1, 5, 25, or 50 mg/kg body weight 24 h before the experiment. Static pressure-volume (PV curves were performed in air- and saline-filled lungs; an estimator of surface tension and tissue works was computed by integrating the area of both curves and reported as work/ml of volume displacement. Paraquat induced a dose-dependent increase of inspiratory surface tension work that reached a significant two-fold order of magnitude for 25 and 50 mg/kg body weight (P<0.05, ANOVA, sparing lung tissue. This kind of lesion was probably due to functional abnormalities of the surfactant system, as was shown by the increase in the hysteresis of the paraquat groups at the highest doses. Hence, paraquat poisoning provides a suitable model of acute lung injury with alveolar instability that can be easily used in experimental protocols of mechanical ventilation

Involvement of TNF-α converting enzyme in the development of psoriasis-like lesions in a mouse model.

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Kenji Sato

Full Text Available TNF-α plays a crucial role in psoriasis; therefore, TNF inhibition has become a gold standard for the treatment of psoriasis. TNF-α is processed from a membrane-bound form by TNF-α converting enzyme (TACE to soluble form, which exerts a number of biological activities. EGF receptor (EGFR ligands, including heparin-binding EGF-like growth factor (HB-EGF, amphiregulin and transforming growth factor (TGF-α are also TACE substrates and are psoriasis-associated growth factors. Vascular endothelial growth factor (VEGF, one of the downstream molecules of EGFR and TNF signaling, plays a key role in angiogenesis for developing psoriasis. In the present study, to assess the possible role of TACE in the pathogenesis of psoriasis, we investigated the involvement of TACE in TPA-induced psoriasis-like lesions in K5.Stat3C mice, which represent a mouse model of psoriasis. In this mouse model, TNF-α, amphiregulin, HB-EGF and TGF-α were significantly up-regulated in the skin lesions, similar to human psoriasis. Treatment of K5.Stat3C mice with TNF-α or EGFR inhibitors attenuated the skin lesions, suggesting the roles of TACE substrates in psoriasis. Furthermore, the skin lesions of K5.Stat3C mice showed down-regulation of tissue inhibitor of metalloproteinase-3, an endogenous inhibitor of TACE, and an increase in soluble TNF-α. A TACE inhibitor abrogated EGFR ligand-dependent keratinocyte proliferation and VEGF production in vitro, suggesting that TACE was involved in both epidermal hyperplasia and angiogenesis during psoriasis development. These results strongly suggest that TACE contributes to the development of psoriatic lesions through releasing two kinds of psoriasis mediators, TNF-α and EGFR ligands. Therefore, TACE could be a potential therapeutic target for the treatment of psoriasis.

Effect of dose reduction on the detection of mammographic lesions: A mathematical observer model analysis

International Nuclear Information System (INIS)

Chawla, Amarpreet S.; Samei, Ehsan; Saunders, Robert; Abbey, Craig; Delong, David

2007-01-01

The effect of reduction in dose levels normally used in mammographic screening procedures on the detection of breast lesions were analyzed. Four types of breast lesions were simulated and inserted into clinically-acquired digital mammograms. Dose reduction by 50% and 75% of the original clinically-relevant exposure levels were simulated by adding corresponding simulated noise into the original mammograms. The mammograms were converted into luminance values corresponding to those displayed on a clinical soft-copy display station and subsequently analyzed by Laguerre-Gauss and Gabor channelized Hotelling observer models for differences in detectability performance with reduction in radiation dose. Performance was measured under a signal known exactly but variable detection task paradigm in terms of receiver operating characteristics (ROC) curves and area under the ROC curves. The results suggested that luminance mapping of digital mammograms affects performance of model observers. Reduction in dose levels by 50% lowered the detectability of masses with borderline statistical significance. Dose reduction did not have a statistically significant effect on detection of microcalcifications. The model results indicate that there is room for optimization of dose level in mammographic screening procedures

Tracing the origin of glomerular extracapillary lesions from parietal epithelial cells.

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Smeets, Bart; Uhlig, Sandra; Fuss, Astrid; Mooren, Fieke; Wetzels, Jack F M; Floege, Jürgen; Moeller, Marcus J

2009-12-01

Cellular lesions form in Bowman's space in both crescentic glomerulonephritis and collapsing glomerulopathy. The pathomechanism and origin of the proliferating cells in these lesions are unknown. In this study, we examined proliferating cells by lineage tracing of either podocytes or parietal epithelial cells (PECs) in the nephrotoxic nephritis model of inflammatory crescentic glomerulonephritis. In addition, we traced the fate of genetically labeled PECs in the Thy-1.1 transgenic mouse model of collapsing glomerulopathy. In both models, cellular bridges composed of PECs were observed between Bowman's capsule and the glomerular tuft. Genetically labeled PECs also populated larger, more advanced cellular lesions. In these lesions, we detected de novo expression of CD44 in activated PECs. In contrast, we rarely identified genetically labeled podocytes within the cellular lesions of crescentic glomerulonephritis. In conclusion, PECs constitute the majority of cells that compose early extracapillary proliferative lesions in both crescentic glomerulonephritis and collapsing glomerulopathy, suggesting similar pathomechanisms in both diseases.

The cannabinoid receptor CB1 contributes to the development of ectopic lesions in a mouse model of endometriosis.

Science.gov (United States)

Sanchez, Ana-Maria; Quattrone, Federica; Pannese, Maria; Ulisse, Adele; Candiani, Massimo; Diaz-Alonso, Javier; Velasco, Guillermo; Panina-Bordignon, Paola

2017-01-01

Does signaling via the cannabinoid (CB 1 ) receptor play a role in the pathogenesis of endometriosis in a mouse model? Mice treated with a CB 1 agonist developed larger ectopic lesions, while less severe lesions developed in the absence of functional CB 1 expression. The expression of components of the endocannabinoid system has been demonstrated in both mouse and human uteri. CB 1 receptors are expressed in human epithelial and stromal cell lines derived from eutopic endometrium and deep infiltrating endometriosis nodules. This was a randomized study in a mouse model of endometriosis. In a first set of experiments, mice with endometriosis were treated with the CB 1 receptor agonist methanandamide (MET) (5 mg/kg, n = 20) on Days 1-5 and 8-12. In a second set of experiments, endometriosis development was evaluated in CB 1 -/- mice and in their wild-type (WT) littermates. Endometriosis-like lesions were induced in Balb/c and C57/Bl6 mice. Two weeks after disease induction, the lesions were counted, measured and either included for immunohistochemistry analysis or frozen for gene expression profiling by semi-quantitative real-time PCR. To limit the role of chance, the experiments were conducted under standardized laboratory conditions with appropriate controls. The lesion total volume was significantly higher in MET-treated compared with vehicle-treated mice (P endometriosis in a mouse model. However, the relative contribution of the CB 1 -mediated signaling pathways active in inflammatory, uterine and peritoneal cells remains to be ascertained. Since the study was performed in a mouse model, the significance of the findings in the human system warrants further investigation. Clarifying the function and regulation of CB 1 and its molecular interactions with endogenous ligands, and how endocannabinoids levels are regulated in women with endometriosis, represent critical areas of research for the potential development of a novel medical treatment of the disease. A

Effects of neostriatal 6-OHDA lesion on performance in a rat sequential reaction time task.

Science.gov (United States)

Domenger, D; Schwarting, R K W

2008-10-31

Work in humans and monkeys has provided evidence that the basal ganglia, and the neurotransmitter dopamine therein, play an important role for sequential learning and performance. Compared to primates, experimental work in rodents is rather sparse, largely due to the fact that tasks comparable to the human ones, especially serial reaction time tasks (SRTT), had been lacking until recently. We have developed a rat model of the SRTT, which allows to study neural correlates of sequential performance and motor sequence execution. Here, we report the effects of dopaminergic neostriatal lesions, performed using bilateral 6-hydroxydopamine injections, on performance of well-trained rats tested in our SRTT. Sequential behavior was measured in two ways: for one, the effects of small violations of otherwise well trained sequences were examined as a measure of attention and automation. Secondly, sequential versus random performance was compared as a measure of sequential learning. Neurochemically, the lesions led to sub-total dopamine depletions in the neostriatum, which ranged around 60% in the lateral, and around 40% in the medial neostriatum. These lesions led to a general instrumental impairment in terms of reduced speed (response latencies) and response rate, and these deficits were correlated with the degree of striatal dopamine loss. Furthermore, the violation test indicated that the lesion group conducted less automated responses. The comparison of random versus sequential responding showed that the lesion group did not retain its superior sequential performance in terms of speed, whereas they did in terms of accuracy. Also, rats with lesions did not improve further in overall performance as compared to pre-lesion values, whereas controls did. These results support previous results that neostriatal dopamine is involved in instrumental behaviour in general. Also, these lesions are not sufficient to completely abolish sequential performance, at least when acquired

Modelling concentration-analgesia relationships for morphine to evaluate experimental pain models

DEFF Research Database (Denmark)

Sverrisdóttir, Eva; Foster, David John Richard; Upton, Richard Neil

2015-01-01

The aim of this study was to develop population pharmacokinetic-pharmacodynamic models for morphine in experimental pain induced by skin heat and muscle pressure, and to evaluate the experimental pain models with regard to assessment of morphine pharmacodynamics. In a randomized, double......-blind, placebo-controlled, crossover study, 39 healthy volunteers received an oral dose of 30 mg morphine hydrochloride or placebo. Non-linear mixed effects modelling was used to describe the plasma concentrations of morphine and metabolites, and the analgesic effect of morphine on experimental pain in skin...... and muscle. Baseline pain metrics varied between individuals and occasions, and were described with interindividual and interoccasion variability. Placebo-response did not change with time. For both pain metrics, morphine effect was proportional to baseline pain and was described with a linear model...

Neurohistologic and ultrastructural lesions in cattle experimentally intoxicated with the plant Prosopis juliflora.

Science.gov (United States)

Tabosa, I M; Riet-Correa, F; Barros, S S; Summers, B A; Simões, S V D; Medeiros, R M T; Nobre, V M T

2006-09-01

Intoxication by pods of Prosopis juliflora (mesquite beans) causes an impairment of cranial nerve function in cattle and goats. In goats, vacuolation of neurons in the trigeminal motor nuclei has been reported. To study the lesions in cattle caused by consumption of P. juliflora pods and dry ground pods, eight 6- to 12-month-old male cattle were divided into 4 groups: group 1 was fed a ration containing 50% of pods; groups 2 and 3 received a ration containing 50 and 75% of dry ground pods, respectively; group 4 was the control. After 200 days, all cattle were killed and sampled for histologic evaluation. Samples of the trigeminal motor nucleus were examined by electron microscopy. All cattle from groups 1, 2, and 3 showed clinical signs resulting from impaired function of cranial nerves V, IX, X, and XII, starting 45-75 days after consumption of the plant. The main histologic lesions were vacuolation and loss of neurons in trigeminal motor nuclei and other motor cranial nerve nuclei with Wallerian-like degeneration in the cranial nerves. Mild denervation atrophy was observed in the masseter and other masticatory muscles. On electron microscopy, neurons of the trigeminal nuclei had markedly swollen mitochondria, with the mitochondrial cristae displaced peripherally, disoriented and disintegrating. Intoxication by P. juliflora seems to have a novel pathogenesis, characterized by a selective, primary, chronic, and progressive injury to mitochondria of neurons of the trigeminal and other cranial nerve nuclei. Cranial nerve degeneration and denervation atrophy of the muscles occurs as a consequence of the neuronal lesion.

Histopathology of motor cortex in an experimental focal ischemic stroke in mouse model.

Science.gov (United States)

de Oliveira, Juçara Loli; Crispin, Pedro di Tárique Barreto; Duarte, Elisa Cristiana Winkelmann; Marloch, Gilberto Domingos; Gargioni, Rogério; Trentin, Andréa Gonçalves; Alvarez-Silva, Marcio

2014-05-01

Experimental ischemia results in cortical brain lesion followed by ischemic stroke. In this study, focal cerebral ischemia was induced in mice by occlusion of the middle cerebral artery. We studied cortical layers I, II/III, V and VI in the caudal forelimb area (CFA) and medial agranular cortex (AGm) from control and C57BL/6 mice induced with ischemic stroke. Based on our analysis of CFA and AGm motor cortex, significant differences were observed in the numbers of neurons, astrocytes and microglia in the superficial II/III and deep V cortical layers. Cellular changes were more prominent in layer V of the CFA with nuclear pyknosis, chromatin fragmentation, necrosis and degeneration, as well as, morphological evidence of apoptosis, mainly in neurons. As result, the CFA was more severely impaired than the AGm in this focal cerebral ischemic model, as evidenced by the proliferation of astrocytes, potentially resulting in neuroinflammation by microglia-like cells. Copyright © 2014 Elsevier B.V. All rights reserved.

EFFECT OF FLUORIDE MOUTHRINSING ON CARIES LESION DEVELOPMENT IN SHARK ENAMEL - AN INSITU CARIES MODEL STUDY

NARCIS (Netherlands)

OGAARD, B; ROLLA, G; DIJKMAN, T; RUBEN, J; ARENDS, J

1991-01-01

Shark enamel consists of nearly pure fluorapatite and has been shown to demineralize in an in situ caries model. The present study was conducted to investigate whether additional fluoride supplementation in the form of mouthrinsing would inhibit lesion development in shark enamel. The study slabs of

A numerical investigation of the functionality of coronary bifurcation lesions with respect to lesion configuration and stenosis severity.

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Pagiatakis, Catherine; Tardif, Jean-Claude; L'Allier, Philippe L; Mongrain, Rosaire

2015-09-18

The intervention of coronary bifurcation lesions is associated with higher rates of peri- and post-procedural clinical events compared to the treatment of isolated lesions. Overall, the factors that influence the dynamics of these types of configurations are still not well understood. A geometric multiscale model, consisting of a 3D representation of the left main coronary artery bifurcation and a 0D representation of the rest of the cardiovascular system, was developed. Computational fluid dynamics simulations of the 3D domain were executed by implementing the multiscale algorithm, in order to characterize the functionality of different multilesional configurations as a function of stenosis severity. The investigation found that coronary branch steal has a significant impact on the functionality of the disease and can render a two-lesion configuration more severe compared to a three-lesion configuration. As a result of the complexity of this phenomenon, it was also suggested that certain lesion configurations could result in false negatives in diagnosis when employing a pullback pressure recording across the tandem lesions. In conclusion, this study showed that coronary bifurcation lesions are subject to intricate haemodynamic interactions which render the characterization of their functionality complex and could have significant clinical implications with regards to their diagnosis and prognosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

The subclinical form of experimental visceral leishmaniasis in dogs

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G. G. S. Oliveira

1993-06-01

Full Text Available Pathological aspects of a subclinical form of experimental canine leishmaniasis is reported here for the first time. Fifteen mongrel dogs were used in the present study. Eight dogs were infected and seven were used as control. Four of the control dogs were inoculated with spleen cells from non-infected hamsters. The eight mongrel dogs inoculated intravenously with amastigotes forms of Leishmania chagasi envolved for periods as long as 25 months without any clinical characteristic sign of classical Visceral Leishmaniasis (VL. Most of the laboratory test results were compatible to those of the seven control animals but culture of bone marrow aspirated material and serologic testing (IIF demonstrated or provided evidence that the animals were infected. The most important and predominant histopathological lesion in infected animals were epitheloid granulomas presented in the liver, spleen, adrenal gland and lung of some animals. Channels containing erythrocytes in some granulomas of the liver suggeste that these granulomas are formed inside sinusoidal capillaries. Despite the animals were proved to be infected and presented characteristic histologic lesions, they did not present external signs of disease. The granulomatous aspect of the lesions indicates a good immunologic reactivity and suggest that a host-parasite equilibrium does exist in the dog experimental model

Experimental Toxoplasmosis in Rats Induced Orally with Eleven Strains of Toxoplasma gondii of Seven Genotypes: Tissue Tropism, Tissue Cyst Size, Neural Lesions, Tissue Cyst Rupture without Reactivation, and Ocular Lesions.

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Jitender P Dubey

Full Text Available The protozoan parasite Toxoplasma gondii is one of the most widely distributed and successful parasites. Toxoplasma gondii alters rodent behavior such that infected rodents reverse their fear of cat odor, and indeed are attracted rather than repelled by feline urine. The location of the parasite encysted in the brain may influence this behavior. However, most studies are based on the highly susceptible rodent, the mouse.Latent toxoplasmosis was induced in rats (10 rats per T. gondii strains of the same age, strain, and sex, after oral inoculation with oocysts (natural route and natural stage of infection of 11 T. gondii strains of seven genotypes. Rats were euthanized at two months post inoculation (p.i. to investigate whether the parasite genotype affects the distribution, location, tissue cyst size, or lesions. Tissue cysts were enumerated in different regions of the brains, both in histological sections as well in saline homogenates. Tissue cysts were found in all regions of the brain. The tissue cyst density in different brain regions varied extensively between rats with many regions highly infected in some animals. Overall, the colliculus was most highly infected although there was a large amount of variability. The cerebral cortex, thalamus, and cerebellum had higher tissue cyst densities and two strains exhibited tropism for the colliculus and olfactory bulb. Histologically, lesions were confined to the brain and eyes. Tissue cyst rupture was frequent with no clear evidence for reactivation of tachyzoites. Ocular lesions were found in 23 (25% of 92 rat eyes at two months p.i. The predominant lesion was focal inflammation in the retina. Tissue cysts were seen in the sclera of one and in the optic nerve of two rats. The choroid was not affected. Only tissue cysts, not active tachyzoite infections, were detected. Tissue cysts were seen in histological sections of tongue of 20 rats but not in myocardium and leg muscle.This study reevaluated

Hemorrhoids: an experimental model in monkeys

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Plapler Hélio

2006-01-01

Full Text Available PURPOSE: Hemorrhoids are a matter of concern due to a painful outcome. We describe a simple, easy and reliable experimental model to produce hemorrhoids in monkeys. METHODS: 14 monkeys (Cebus apella were used. After general anesthesia, hemorrhoids were induced by ligation of the inferior hemorrhoidal vein, which is very alike to humans. The vein was located through a perianal incision, dissected and ligated with a 3-0 vicryl. The skin was sutured with a 4-0 catgut thread. Animals were kept in appropriate cages and evaluated daily. RESULTS: Nine days later there were hemorrhoidal piles in the anus in fifty percent (50% of the animals. Outcome was unremarkable. There was no bleeding and all animals showed no signs of pain or suffering. CONCLUSION: This is an affordable and reliable experimental model to induce hemorrhoids for experimental studies.

Stenting for curved lesions using a novel curved balloon: Preliminary experimental study.

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Tomita, Hideshi; Higaki, Takashi; Kobayashi, Toshiki; Fujii, Takanari; Fujimoto, Kazuto

2015-08-01

Stenting may be a compelling approach to dilating curved lesions in congenital heart diseases. However, balloon-expandable stents, which are commonly used for congenital heart diseases, are usually deployed in a straight orientation. In this study, we evaluated the effect of stenting with a novel curved balloon considered to provide better conformability to the curved-angled lesion. In vitro experiments: A Palmaz Genesis(®) stent (Johnson & Johnson, Cordis Co, Bridgewater, NJ, USA) mounted on the Goku(®) curve (Tokai Medical Co. Nagoya, Japan) was dilated in vitro to observe directly the behavior of the stent and balloon assembly during expansion. Animal experiment: A short Express(®) Vascular SD (Boston Scientific Co, Marlborough, MA, USA) stent and a long Express(®) Vascular LD stent (Boston Scientific) mounted on the curved balloon were deployed in the curved vessel of a pig to observe the effect of stenting in vivo. In vitro experiments: Although the stent was dilated in a curved fashion, stent and balloon assembly also rotated conjointly during expansion of its curved portion. In the primary stenting of the short stent, the stent was dilated with rotation of the curved portion. The excised stent conformed to the curved vessel. As the long stent could not be negotiated across the mid-portion with the balloon in expansion when it started curving, the mid-portion of the stent failed to expand fully. Furthermore, the balloon, which became entangled with the stent strut, could not be retrieved even after complete deflation. This novel curved balloon catheter might be used for implantation of the short stent in a curved lesion; however, it should not be used for primary stenting of the long stent. Post-dilation to conform the stent to the angled vessel would be safer than primary stenting irrespective of stent length. Copyright © 2014 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

A micro-PET/CT approach using O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine in an experimental animal model of F98 glioma for BNCT

Energy Technology Data Exchange (ETDEWEB)

Menichetti, L., E-mail: luca.menichetti@ifc.cnr.it [CNR Institute of Clinical Physiology, Pisa (Italy); Petroni, D.; Panetta, D. [CNR Institute of Clinical Physiology, Pisa (Italy); Burchielli, S. [Fondazione CNR/Regione Toscana G. Monasterio, Pisa (Italy); Bortolussi, Silva [Dept. Theoretical and Nuclear Physics, University of Pavia, Pavia (Italy); Matteucci, M. [Scuola Superiore Sant' Anna, Pisa (Italy); Pascali, G.; Del Turco, S. [CNR Institute of Clinical Physiology, Pisa (Italy); Del Guerra, A. [Department of Physics, University of Pisa, Pisa (Italy); Altieri, S. [Dept. Theoretical and Nuclear Physics, University of Pavia, Pavia (Italy); Salvadori, P.A. [CNR Institute of Clinical Physiology, Pisa (Italy)

2011-12-15

The present study focuses on a micro-PET/CT application to be used for experimental Boron Neutron Capture Therapy (BNCT), which integrates, in the same frame, micro-CT derived anatomy and PET radiotracer distribution. Preliminary results have demonstrated that {sup 18}F-fluoroethyl-tyrosine (FET)/PET allows the identification of the extent of cerebral lesions in F98 tumor bearing rat. Neutron autoradiography and {alpha}-spectrometry on axial tissues slices confirmed the tumor localization and extraction, after the administration of fructose-boronophenylalanine (BPA). Therefore, FET-PET approach can be used to assess the transport, the net influx, and the accumulation of FET, as an aromatic amino acid analog of BPA, in experimental animal model. Coregistered micro-CT images allowed the accurate morphological localization of the radiotracer distribution and its potential use for experimental BNCT.

Improving the physiological realism of experimental models.

Science.gov (United States)

Vinnakota, Kalyan C; Cha, Chae Y; Rorsman, Patrik; Balaban, Robert S; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A; Jeneson, Jeroen A L

2016-04-06

The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these models rely on the analysis and integration of experimental data. As such, the success of VPH depends on the availability of physiologically realistic experimental models (E-Models) of human organ function that can be parametrized to test the numerical models. Here, the current state of suitable E-models, ranging from in vitro non-human cell organelles to in vivo human organ systems, is discussed. Specifically, challenges and recent progress in improving the physiological realism of E-models that may benefit the VPH project are highlighted and discussed using examples from the field of research on cardiovascular disease, musculoskeletal disorders, diabetes and Parkinson's disease.

Safety and performance analysis of acriflavine and methylene blue for in vivo imaging of precancerous lesions using fibered confocal fluorescence microscopy (FCFM): an experimental study.

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Obstoy, Bérengère; Salaun, Mathieu; Veresezan, Liana; Sesboüé, Richard; Bohn, Pierre; Boland, François-Xavier; Thiberville, Luc

2015-03-31

Fibered confocal fluorescence microscopy (FCFM) allows in vivo investigation of pulmonary microstructures. However, the bronchial epithelium can only be imaged using exogenous fluorophores. The objective of this study is to compare methylene blue (MB) and acriflavine genotoxicity and to assess FCFM performance for in vivo imaging of precancerous lesions. Genotoxicity was assessed using the comet assay on both cultured human lymphocytes and NCI-H460 cells, which had been exposed to MB or acriflavine before being illuminated at 660 or 488 nm, respectively. FCFM was performed on precancerous lesions in the hamster cheek pouch model, following topical application of the fluorophores. FCFM data were analyzed according to histology. No genotoxicity was found using 0.01% (w/v) MB after illumination at 660 nm for 2 and 15 min (5 mW). Acriflavine exposure (0.025%) led to DNA damages, increasing from 2 to 15 min of light exposure at 448 nm in both lymphocytes (83.4 to 88%, p = 0.021) and NCI H460 cell populations (79.9 to 84.6%, p = 0.045). In total, 11 invasive carcinoma, 24 reserve cell hyperplasia, and 17 dysplasia lesions were imaged using FCFM in vivo. With both fluorophores, the cellular density increased from hyperplasia to high-grade dysplasia (p < 0.05). With MB, the cellular diameter significantly decreased (48.9 to 13.9 μm) from hyperplasia to carcinoma (p < 0.05). In this model, a cut-off diameter of 30 μm enabled the diagnosis of high-grade lesions with a sensitivity of 94.7% and a specificity of 97%. Methylene blue can be used safely to image precancerous lesions in vivo. This study does not support the use of acriflavine in humans.

Gynostemma pentaphyllum Ethanolic Extract Protects Against Memory Deficits in an MPTP-Lesioned Mouse Model of Parkinson's Disease Treated with L-DOPA.

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Kim, Kyung Sook; Zhao, Ting Ting; Shin, Keon Sung; Park, Hyun Jin; Cho, Yoon Jeong; Lee, Kyung Eun; Kim, Seung Hwan; Lee, Myung Koo

2017-01-01

This study investigated the effects of ethanol extract from Gynostemma pentaphyllum (GP-EX) on memory deficits in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD) (MPTP-lesioned mice). MPTP (30 mg/kg/day, 5 days)-lesioned mice showed deficits of habit learning memory and spatial memory, which were further aggravated by treatment with L-3,4-dihydroxyphenylalanine (L-DOPA) (25 mg/kg, 21 days). However, treatment with GP-EX (50 mg/kg, 21 days) ameliorated memory deficits in MPTP-lesioned mice treated with L-DOPA (25 mg/kg): GP-EX prevented the decreases in retention latency time in the passive avoidance test and tyrosine hydroxylase-immunopositive cells and dopamine levels in the nigrostriatum. GP-EX also reduced increases in retention transfer latency time of the elevated plus-maze test and expression of N-methyl-D-aspartate (NMDA) receptor and improved decreases in phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB) in the hippocampus in the same models. By contrast, L-DOPA treatment (10 mg/kg, 21 days) ameliorated memory deficits in MPTP-lesioned mice, which were further improved by GP-EX treatment. These results suggest that GP-EX ameliorates habit learning memory deficits by activating dopaminergic neurons and spatial memory deficits by modulating NMDA receptor-ERK1/2-CREB system in MPTP-lesioned mice treated with L-DOPA. GP-EX may serve as an adjuvant phytonutrient for memory deficits in PD.

Retinoic acid suppresses growth of lesions, inhibits peritoneal cytokine secretion, and promotes macrophage differentiation in an immunocompetent mouse model of endometriosis.

Science.gov (United States)

Wieser, Friedrich; Wu, Juanjuan; Shen, Zhaoju; Taylor, Robert N; Sidell, Neil

2012-06-01

To determine the effects of all-trans-retinoic acid (RA) on establishment and growth of endometrial lesions, peritoneal interleukin-6 (IL-6) and macrophage chemotactic factor-1 (MCP-1) concentrations, and CD38, CD11b, and F4/80 expression on peritoneal macrophages in an immunocompetent mouse model of endometriosis. Experimental transplantation study using mice. Academic medical center. C57BL/6 recipient mice and syngeneic green fluorescent protein transgenic (GFP+) mice. Recipient mice were inoculated with GFP+ minced uterine tissue to induce endometriosis and treated with RA (400 nmol/day) or vehicle for 17 days (3 days before to 14 days after tissue injection). Total number of GFP+ implants in recipient mice, number of implants showing visible blood vessels, total volume of established lesions per mouse, concentrations of IL-6 and MCP-1 in peritoneal fluid, and expression of CD11b, F4/80, and CD38 on peritoneal macrophages. Retinoic acid treatment for 17 days reduced the number of implants versus controls and decreased the frequency of lesions with vessels. Peritoneal washings in RA-treated animals had lower concentrations of IL-6 and MCP-1 than controls 3 days after endometrial inoculation and lower levels of IL-6 on day 14 after inoculation. Concomitant with these effects on day 14, CD38, CD11b, and F4/80 were higher on macrophages from RA-treated mice versus controls. The development of endometriotic implants is inhibited by RA. This effect may be caused, at least in part, by reduced IL-6 and MCP-1 production and enhanced differentiation of peritoneal macrophages. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Reconstructing in-vivo reflectance spectrum of pigmented skin lesion by Monte Carlo simulation

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Wang, Shuang; He, Qingli; Zhao, Jianhua; Lui, Harvey; Zeng, Haishan

2012-03-01

In dermatology applications, diffuse reflectance spectroscopy has been extensively investigated as a promising tool for the noninvasive method to distinguish melanoma from benign pigmented skin lesion (nevus), which is concentrated with the skin chromophores like melanin and hemoglobin. We carried out a theoretical study to examine melanin distribution in human skin tissue and establish a practical optical model for further pigmented skin investigation. The theoretical simulation was using junctional nevus as an example. A multiple layer skin optical model was developed on established anatomy structures of skin, the published optical parameters of different skin layers, blood and melanin. Monte Carlo simulation was used to model the interaction between excitation light and skin tissue and rebuild the diffuse reflectance process from skin tissue. A testified methodology was adopted to determine melanin contents in human skin based on in vivo diffuse reflectance spectra. The rebuild diffuse reflectance spectra were investigated by adding melanin into different layers of the theoretical model. One of in vivo reflectance spectra from Junctional nevi and their surrounding normal skin was studied by compare the ratio between nevus and normal skin tissue in both the experimental and simulated diffuse reflectance spectra. The simulation result showed a good agreement with our clinical measurements, which indicated that our research method, including the spectral ratio method, skin optical model and modifying the melanin content in the model, could be applied in further theoretical simulation of pigmented skin lesions.

Transsynaptic neuronal degeneration of optic nerves associated with bilateral occipital lesions

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Sachdev Mahipal

1990-01-01

Full Text Available A case is reported of a 9-year old male who presented with abnormal behaviour and progressive diminution of vision. Pupils were middilated in both eyes but the pupillary reflexes were preserved. Fundus examination revealed a bilateral optic atrophy and radiological investigations showed a bilateral occipital calcification. We hereby document a case of retrograde transsynaptic neuronal degeneration of the visual system secondary to bilateral occipital lesions. Transsynapptic neuronal degeneration of optic nerves consequent to occipital lobe lesions is a rare phenomenon. Experimentally occipital lobe ablation in non-human primates has been shown to result in optic atrophy. Herein, we document a case of retrograde transsynaptic neuronal degeneration of the visual system secondary to bilateral occipital lesions.

Eccentric Training for Tendon Healing After Acute Lesion: A Rat Model.

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Kaux, Jean-François; Libertiaux, Vincent; Leprince, Pierre; Fillet, Marianne; Denoel, Vincent; Wyss, Clémence; Lecut, Christelle; Gothot, André; Le Goff, Caroline; Croisier, Jean-Louis; Crielaard, Jean-Michel; Drion, Pierre

2017-05-01

The tendon is a dynamic entity that remodels permanently. Platelet-rich plasma (PRP) injection has been shown to have a beneficial effect on tendon healing after lesion in rats. Furthermore, eccentric exercise seems to improve the mechanical quality of the tendon. A combination of PRP injection and eccentric training might be more effective than either treatment alone. Controlled laboratory study. Adult male rats were anesthetized, an incision was performed in the middle of their left patellar tendon and an injection of physiological fluid (PF) or homologous PRP was randomly made at the lesion level. The rats were then divided into 2 groups: the eccentric group, undergoing eccentric training 3 times a week, and the untrained group, without any training. Thus, 4 groups were compared. After 5 weeks, the tendons were removed and their ultimate tensile strength and energy were measured. Tendons were frozen for proteomic analyses when all biomechanical tests were completed. Statistical analysis was performed with linear mixed effect models. No significant difference was found between the treatments using PF injection or PRP injection alone. However, the value of the ultimate tensile force at rupture was increased by 4.5 N (108% of control, P = .006) when eccentric training was performed. An intragroup analysis revealed that eccentric training significantly improved the ultimate force values for the PRP group. Proteomic analysis revealed that eccentric training led to an increase in abundance of several cytoskeletal proteins in the PF group, while a decrease in abundance of enzymes of the glycolytic pathway occurred in the PRP-treated groups, indicating that this treatment might redirect the exercise-driven metabolic plasticity of the tendon. Eccentric training altered the metabolic plasticity of tendon and led to an improvement of injured tendon resistance regardless of the treatment injected (PF or PRP). This study demonstrates the necessity of eccentric rehabilitation

In vivo T2* weighted MRI visualizes cardiac lesions in murine models of acute and chronic viral myocarditis.

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Xavier Helluy

Full Text Available Acute and chronic forms of myocarditis are mainly induced by virus infections. As a consequence of myocardial damage and inflammation dilated cardiomyopathy and chronic heart failure may develop. The gold standard for the diagnosis of myocarditis is endomyocardial biopsies which are required to determine the etiopathogenesis of cardiac inflammatory processes. However, new non-invasive MRI techniques hold great potential in visualizing cardiac non-ischemic inflammatory lesions at high spatial resolution, which could improve the investigation of the pathophysiology of viral myocarditis.Here we present the discovery of a novel endogenous T2* MRI contrast of myocardial lesions in murine models of acute and chronic CVB3 myocarditis. The evaluation of infected hearts ex vivo and in vivo by 3D T2w and T2*w MRI allowed direct localization of virus-induced myocardial lesions without any MRI tracer or contrast agent. T2*w weighted MRI is able to detect both small cardiac lesions of acute myocarditis and larger necrotic areas at later stages of chronic myocarditis, which was confirmed by spatial correlation of MRI hypointensity in myocardium with myocardial lesions histologically. Additional in vivo and ex vivo MRI analysis proved that the contrast mechanism was due to a strong paramagnetic tissue alteration in the vicinity of myocardial lesions, effectively pointing towards iron deposits as the primary contributor of contrast. The evaluation of the biological origin of the MR contrast by specific histological staining and transmission electron microscopy revealed that impaired iron metabolism primarily in mitochondria caused iron deposits within necrotic myocytes, which induces strong magnetic susceptibility in myocardial lesions and results in strong T2* contrast.This T2*w MRI technique provides a fast and sensitive diagnostic tool to determine the patterns and the severity of acute and chronic enteroviral myocarditis and the precise localization of

Accuracy of the detection of infratentorial stroke lesions using perfusion CT: an experimenter-blinded study

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Lee, In Hyouk; Kim, Myung Soon; Kim, Young Ju; Lee, Myeong Sub [Yonsei University, Department of Radiology, Wonju College of Medicine, Wonju (Korea, Republic of); You, Joshua H. [Center for Health, Wellness, Fitness, Prevention, and Healing Across the Life Span, Department of Physical Therapy, Graduate School of Rehabilitation Science, Yonsei University, Center for Movement Impairment Solutions, Wonju City (Korea, Republic of); Lee, Ji Yong [Yonsei University, Department of Neurology, Wonju College of Medicine, Wonju (Korea, Republic of); Whang, Kum [Yonsei University, Department of Neurosurgery, Wonju College of Medicine, Wonju (Korea, Republic of)

2010-12-15

Although perfusion CT (PCT) for the detection of supratentorial stroke is well established, there is a dearth of evidence of its effectiveness in the detection of infratentorial stroke. Hence, this study compared sensitivity, specificity, and accuracy of PCT maps between infratentorial and supratentorial stroke lesions. One hundred patients with acute stroke who had successfully undergone near whole-brain PCT with the toggling table technique and follow-up MRI were included. Wilcoxon Mann-Whitney test was performed at P < 0.01. There was no significant statistical difference in the accuracy (91.79% vs. 93.23% in regional cerebral blood volume; 92.26% vs. 95.31% in regional cerebral blood flow; 89.17% vs. 92.71% in mean transit time; 89.76% vs. 92.19% in time to peak; P > 0.01 in all PCT maps) between supratentorial and infratentorial stroke. Also, there was no remarkable difference in both sensitivity and specificity of PCT maps. This was the first study to investigate the accuracy of PCT with the toggling table technique in detection of infratentorial stroke lesions. Clinically, PCT is highly reliable and accurate in detecting infratentorial stroke lesions. (orig.)

Establishment of a model of cochlear lesions in rats to study potential gene therapy for sensorineural hearing loss.

Science.gov (United States)

Wang, Ye; Qiao, Li; Chen, Yang; Wen, Liting; Yue, Bo; Qiu, Jianhua; Wu, Shengxi

2015-12-01

Sensorineural hearing loss seriously influences a patient's daily life, and no effective treatments exist to date. Gene therapy is a potential treatment for regenerating hair cells to restore hearing. In this study, we established a cochlear lesions model to study hair cell regeneration by co-administration of kanamycin and furosemide. After the injections, we assessed the survival of outer hair cells (OHC), inner hair cells (IHC), supporting cells (SC), spiral ganglion neurons (SGN) and peripheral axons. Moreover, we used two viral vectors to detect the transgene distribution. Our results showed at 12h post-treatment, numerous OHC were missing in the basal turn. At 24h post-treatment, all OHCs in basal half of the cochlea were lost, and by 48h, OHC loss had spread to the apical coil. Four days after the injections, all OHCs were absent. At 1mo post-treatment, the organ of Corti had collapsed. In contrast, most of the SC remained 4d after the injections. The loss of SGN and peripheral axons was consistent with this time course post-treatment. The results of transgene distribution suggested the correlative gene can be transferred into the organ of Corti using adenoviruses (AdV) vectors and lentiviruses (LV) vectors in our cochlear lesion model. We assessed the details of HC death at more time point and chosen the time point for gene transfer in this model. We conclude that this cochlear lesion model would be suitable for the study of hair cell regeneration. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Multispectral recordings and analysis of psoriasis lesions

DEFF Research Database (Denmark)

Clemmensen, Line Katrine Harder; Ersbøll, Bjarne Kjær

2006-01-01

An objective method to evaluate the severeness of psoriasis lesions is proposed. In order to obtain objectivity multi-spectral imaging is used. The multi-spectral images give rise to a large p, small n problem which is solved by use of elastic net model selection. The method is promising for furt......An objective method to evaluate the severeness of psoriasis lesions is proposed. In order to obtain objectivity multi-spectral imaging is used. The multi-spectral images give rise to a large p, small n problem which is solved by use of elastic net model selection. The method is promising...

Experimentally induced cam impingement in the sheep hip.

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Siebenrock, Klaus A; Fiechter, Ruth; Tannast, Moritz; Mamisch, Tallal C; von Rechenberg, Brigitte

2013-04-01

Sheep hips have a natural non-spherical femoral head similar to a cam-type deformity in human beings. By performing an intertrochanteric varus osteotomy, cam-type femoro-acetabular impingement (FAI) during flexion can be created. We tested the hypotheses that macroscopic lesions of the articular cartilage and an increased Mankin score (MS) can be reproduced by an experimentally induced cam-type FAI in this ovine in vivo model. Furthermore, we hypothesized that the MS increases with longer ambulatory periods. Sixteen sheep underwent unilateral intertrochanteric varus osteotomy of the hip with the non-operated hip as a control. Four sheep were sacrificed after 14, 22, 30, and 38-weeks postoperatively. We evaluated macroscopic chondrolabral alterations, and recorded the MS, based on histochemical staining, for each ambulatory period. A significantly higher prevalence of macroscopic chondrolabral lesions was found in the impingement zone of the operated hips. The MS was significantly higher in the acetabular/femoral cartilage of the operated hips. Furthermore, these scores increased as the length of the ambulatory period increased. Cam-type FAI can be induced in an ovine in vivo model. Localized chondrolabral degeneration of the hip, similar to that seen in humans (Tannast et al., Clin Orthop Relat Res 2008; 466: 273-280; Beck et al., J Bone Joint Surg Br 2005; 87: 1012-1018), can be reproduced. This experimental sheep model can be used to study cam-type FAI. Copyright © 2012 Orthopaedic Research Society.

Impact of Lesion Length on Functional Significance in Intermediate Coronary Lesions

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Morteza Safi

2017-07-01

Full Text Available Introduction: The present study aimed at assessing the role of lesion length in predicting Fractional Flow Reserve (FFR value for physiological evaluation of intermediate coronary lesions.Methods: In the current study, 68 patients with 83 coronary lesions were enrolled. All of the patients in this study underwent routine coronary angiography, according to appropriate indications. To evaluate physiologically significant intermediate coronary stenosis (defined between 40% and 70% on visual estimation, the Fractional Flow Reserve (FFR study was performed and the Quantitative Coronary Angiography (QCA data were also assessed for measurement of lesion length. The correlation between QCA data and FFR values was also examined.Results: Eighty-three lesions were evaluated from 68 patients. Stenosis was considered physiologically significant when FFR was lower than 0.75. The FFR was significant in twelve lesions (14.5%. There was a negative correlation between FFR value and lesion length (r = -0.294 and P = 0.013. Moreover, lesion length in physiologically significant FFR group (21.07  ± 6.9 was greater than that of the non-significant FFR group (15.23 ± 6.5 (P value < 0.05. Furthermore, the correlation between QCA data and FFR values was also investigated, yet, there was only a positive correlation between FFR and Minimum Luminal Diameter (MLD values (r = 0.248 and P value = 0.04. The Receiver Operating Characteristic (ROC curve analysis for predicting the significant FFR value demonstrated that a lesion length greater than 17.5 mm was the best cut-off point for prediction of the significant FFR value with acceptable sensitivity and specificity of 83.3% and 68.8%, respectively.Conclusions: There is a negative correlation between lesion length and FFR value in intermediate coronary lesions. In addition, a lesion length greater than 17.5 mm is the best cut- off point for prediction of significant FFR values.

Effects of hecogenin and its possible mechanism of action on experimental models of gastric ulcer in mice.

Science.gov (United States)

Santos Cerqueira, Gilberto; dos Santos e Silva, Gabriela; Rios Vasconcelos, Emiliano; Fragoso de Freitas, Ana Paula; Arcanjo Moura, Brinell; Silveira Macedo, Danielle; Lopes Souto, Augusto; Barbosa Filho, José Maria; de Almeida Leal, Luzia Kalyne; de Castro Brito, Gerly Anne; Souccar, Caden; de Barros Viana, Glauce Socorro

2012-05-15

This study investigates the gastroprotective effects of hecogenin, a steroid saponin isolated from Agave sisalana, on experimental models of gastric ulcer. Male Swiss mice were used in the models of ethanol- and indometacin-induced gastric ulcer. To clarify the hecogenin mechanism of action, the roles of nitric oxide (NO), sulfhydryls (GSH), K⁺(ATP) channels and prostaglandins were also investigated, and measurements of lipid peroxidation (TBARS assay) and nitrite levels in the stomach of hecogenin-treated and untreated animals were performed. Furthermore, the effects of hecogenin on myeloperoxidase (MPO) release from human neutrophils were assessed in vitro. Our results showed that hecogenin (3.1, 7.5, 15, 30, 60 and 90 mg/kg, p.o.) acutely administered, before ethanol or indomethacin, exhibited a potent gastroprotective effect. Although the pretreatments with L-NAME, an iNOS inhibitor, and capsazepine, a TRPV1 receptor agonist, were not able to reverse the hecogenin effect, this was reversed by glibenclamide, a K⁺(ATP) blocker, and indomethacin in the model of ethanol-induced gastric lesions. The hecogenin pretreatment normalized GSH levels and significantly reduced lipid peroxidation and nitrite levels in the stomach, as evaluated by the ethanol-induced gastric lesion model. The drug alone increased COX-2 expression and this effect was further enhanced in the presence of ethanol. It also decreased MPO release and significantly protected the gastric mucosa. In conclusion, we showed that hecogenin presents a significant gastroprotective effect that seems to be mediated by K⁺(ATP) channels opening and the COX-2/PG pathway. In addition, its antioxidant and anti-inflammatory properties may play a role in the gastroprotective drug effect. Copyright © 2012 Elsevier B.V. All rights reserved.

Monkeypox disease transmission in an experimental setting: prairie dog animal model.

Directory of Open Access Journals (Sweden)

Christina L Hutson

Full Text Available Monkeypox virus (MPXV is considered the most significant human public health threat in the genus Orthopoxvirus since the eradication of variola virus (the causative agent of smallpox. MPXV is a zoonotic agent endemic to forested areas of Central and Western Africa. In 2003, MPXV caused an outbreak in the United States due to the importation of infected African rodents, and subsequent sequential infection of North American prairie dogs (Cynomys ludovicianus and humans. In previous studies, the prairie dog MPXV model has successfully shown to be very useful for understanding MPXV since the model emulates key characteristics of human monkeypox disease. In humans, percutaneous exposure to animals has been documented but the primary method of human-to-human MPXV transmission is postulated to be by respiratory route. Only a few animal model studies of MPXV transmission have been reported. Herein, we show that MPXV infected prairie dogs are able to transmit the virus to naive animals through multiple transmission routes. All secondarily exposed animals were infected with MPXV during the course of the study. Notably, animals secondarily exposed appeared to manifest more severe disease; however, the disease course was very similar to those of experimentally challenged animals including inappetence leading to weight loss, development of lesions, production of orthopoxvirus antibodies and shedding of similar levels or in some instances higher levels of MPXV from the oral cavity. Disease was transmitted via exposure to contaminated bedding, co-housing, or respiratory secretions/nasal mucous (we could not definitively say that transmission occurred via respiratory route exclusively. Future use of the model will allow us to evaluate infection control measures, vaccines and antiviral strategies to decrease disease transmission.

Experimental Modeling of Dynamic Systems

DEFF Research Database (Denmark)

Knudsen, Morten Haack

2006-01-01

An engineering course, Simulation and Experimental Modeling, has been developed that is based on a method for direct estimation of physical parameters in dynamic systems. Compared with classical system identification, the method appears to be easier to understand, apply, and combine with physical...

A level set method for multiple sclerosis lesion segmentation.

Science.gov (United States)

Zhao, Yue; Guo, Shuxu; Luo, Min; Shi, Xue; Bilello, Michel; Zhang, Shaoxiang; Li, Chunming

2018-06-01

In this paper, we present a level set method for multiple sclerosis (MS) lesion segmentation from FLAIR images in the presence of intensity inhomogeneities. We use a three-phase level set formulation of segmentation and bias field estimation to segment MS lesions and normal tissue region (including GM and WM) and CSF and the background from FLAIR images. To save computational load, we derive a two-phase formulation from the original multi-phase level set formulation to segment the MS lesions and normal tissue regions. The derived method inherits the desirable ability to precisely locate object boundaries of the original level set method, which simultaneously performs segmentation and estimation of the bias field to deal with intensity inhomogeneity. Experimental results demonstrate the advantages of our method over other state-of-the-art methods in terms of segmentation accuracy. Copyright © 2017 Elsevier Inc. All rights reserved.

Human papillomavirus in oral lesions Virus papiloma humano en lesiones orales

Directory of Open Access Journals (Sweden)

Joaquín V. Gónzalez

2007-08-01

Full Text Available Growing evidence suggests a role for human papillomavirus (HPV in oral cancer; however its involvement is still controversial. This study evaluates the frequency of HPV DNA in a variety of oral lesions in patients from Argentina. A total of 77 oral tissue samples from 66 patients were selected (cases; the clinical-histopathological diagnoses corresponded to: 11 HPV- associated benign lesions, 8 non-HPV associated benign lesions, 33 premalignant lesions and 25 cancers. Sixty exfoliated cell samples from normal oral mucosa were used as controls. HPV detection and typing were performed by polymerase chain reaction (PCR using primers MY09, 11, combined with RFLP or alternatively PCR using primers GP5+, 6+ combined with dot blot hybridization. HPV was detected in 91.0% of HPV- associated benign lesions, 14.3% of non-HPV associated benign lesions, 51.5% of preneoplasias and 60.0% of cancers. No control sample tested HPV positive. In benign HPV- associated lesions, 30.0% of HPV positive samples harbored high-risk types, while in preneoplastic lesions the value rose to 59.9%. In cancer lesions, HPV detection in verrucous carcinoma was 88.9% and in squamous cell carcinoma 43.8%, with high-risk type rates of 75.5% and 85.6%, respectively. The high HPV frequency detected in preneoplastic and neoplastic lesions supports an HPV etiological role in at least a subset of oral cancers.Crecientes evidencias sugieren que el virus Papiloma humano (HPV tiene un rol en el cáncer oral; sin embargo su participación es todavía controvertida. Este estudio evalúa la frecuencia de ADN de HPV en una variedad de lesiones orales de pacientes de Argentina. Se seleccionaron 77 muestras de tejido oral de 66 pacientes (casos; el diagnóstico histo-patológico correspondió a: 11 lesiones benignas asociadas a HPV, 8 lesiones benignas no asociadas a HPV, 33 lesiones premalignas y 25 cánceres. Como controles se usaron 60 muestras de células exfoliadas de mucosa oral normal. La

Is the ipsilateral cortex surrounding the lesion or the non-injured contralateral cortex important for motor recovery in rats with photochemically induced cortical lesions?

Science.gov (United States)

Takata, Kotaro; Yamauchi, Hideki; Tatsuno, Hisashi; Hashimoto, Keiji; Abo, Masahiro

2006-01-01

To determine whether the ipsilateral cortex surrounding the lesion or the non-injured contralateral cortex is important for motor recovery after brain damage in the photochemically initiated thrombosis (PIT) model. We induced PIT in the sensorimotor cortex in rats and examined the recovery of motor function using the beam-walking test. In 24 rats, the right sensorimotor cortex was lesioned after 2 days of training for the beam-walking test (group 1). After 10 days, PIT was induced in the left sensorimotor cortex. Eight additional rats (group 2) received 2 days training in beam walking, then underwent the beam-walking test to evaluate function. After 10 days of testing, the left sensorimotor cortex was lesioned and recovery was monitored by the beam-walking test for 8 days. In group 1 animals, left hindlimb function caused by a right sensorimotor cortex lesion recovered within 10 days after the operation. Right hindlimb function caused by the left-side lesion recovered within 6 days. In group 2, right hindlimb function caused by induction of the left-side lesion after a total of 12 days of beam-walking training and testing recovered within 6 days as with the double PIT model. The training effect may be relevant to reorganization and neuromodulation. Motor recovery patterns did not indicate whether motor recovery was dependent on the ipsilateral cortex surrounding the lesion or the cortex of the contralateral side. The results emphasize the need for selection of appropriate programs tailored to the area of cortical damage in order to enhance motor functional recovery in this model. Copyright 2006 S. Karger AG, Basel.

Characterization of enamel caries lesions in rat molars using synchrotron X-ray microtomography

Energy Technology Data Exchange (ETDEWEB)

Free, R.D.; DeRocher, K.; Stock, S.R.; Keane, D.; Scott-Anne, K.; Bowen, W.H.; Joester, D. (Rochester); (NWU)

2017-08-18

Dental caries is a ubiquitous infectious disease with a nearly 100% lifetime prevalence. Rodent caries models are widely used to investigate the etiology, progression and potential prevention or treatment of the disease. To explore the suitability of these models for deeper investigations of intact surface zones during enamel caries, the structures of early-stage carious lesions in rats were characterized and compared with previous reports on white spot enamel lesions in humans. Synchrotron X-ray microcomputed tomography non-destructively mapped demineralization in carious rat molar specimens across a range of caries severity, identifying 52 lesions across the 30 teeth imaged. Of these lesions, 13 were shown to have intact surface zones. Depth profiles of fractional mineral density were qualitatively similar to lesions in human teeth. However, the thickness of the surface zone in the rat model ranges from 10 to 58 µm, and is therefore significantly thinner than in human enamel. These results indicate that a fraction of lesions in rat caries possess an intact surface zone and are qualitatively similar to human lesions at the micrometer scale. This suggests that rat caries models may be a suitable analog through which to investigate the structure of surface zone enamel and its role during dental caries.

Experimental modeling of swirl flows in power plants

Science.gov (United States)

Shtork, S. I.; Litvinov, I. V.; Gesheva, E. S.; Tsoy, M. A.; Skripkin, S. G.

2018-03-01

The article presents an overview of the methods and approaches to experimental modeling of various thermal and hydropower units - furnaces of pulverized coal boilers and flow-through elements of hydro turbines. The presented modeling approaches based on a combination of experimentation and rapid prototyping of working parts may be useful in optimizing energy equipment to improve safety and efficiency of industrial energy systems.

Molecular pathogenesis of precursor lesions of pancreatic ductal adenocarcinoma.

Science.gov (United States)

Biankin, Andrew V; Kench, James G; Dijkman, Floriaan P; Biankin, Sandra A; Henshall, Susan M

2003-02-01

Precursor lesions are assuming greater importance in the study of pancreatic ductal adenocarcinoma. As pancreatic cancer is almost universally fatal due to late clinical presentation and biological aggressiveness, characterisation of its precursor lesions may create scope for early diagnosis and improved outcome with conventional therapies as well as the development of novel therapeutic and preventative strategies. Pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous tumours (IPMTs) are thought to be precursor lesions of ductal adenocarcinoma of the pancreas. Recent work has focused on the molecular aberrations associated with these lesions leading to the formulation of a progression model for pancreatic cancer. Progressive histopathological changes along the progression model are associated with aberrations of cell cycle regulatory and growth factor signalling molecules that occur in pancreatic cancer at high frequency and are common to many cancers. Characterisation of these molecular aberrations provides scope for the development of novel diagnostic and treatment strategies that will ultimately impact on the outcome for people who develop pancreatic cancer.

Therapeutic enhancement of protective immunity during experimental leishmaniasis.

Directory of Open Access Journals (Sweden)

Senad Divanovic

2011-09-01

Full Text Available Leishmaniasis remains a significant cause of morbidity and mortality in the tropics. Available therapies are problematic due to toxicity, treatment duration and emerging drug resistance. Mouse models of leishmaniasis have demonstrated that disease outcome depends critically on the balance between effector and regulatory CD4(+ T cell responses, something mirrored in descriptive studies of human disease. Recombinant IL-2/diphtheria toxin fusion protein (rIL-2/DTx, a drug that is FDA-approved for the treatment of cutaneous T cell lymphoma, has been reported to deplete regulatory CD4(+ T cells.We investigated the potential efficacy of rIL-2/DTx as adjunctive therapy for experimental infection with Leishmania major. Treatment with rIL-2/DTx suppressed lesional regulatory T cell numbers and was associated with significantly increased antigen-specific IFN-γ production, enhanced lesion resolution and decreased parasite burden. Combined administration of rIL-2/DTx and sodium stibogluconate had additive biological and therapeutic effects, allowing for reduced duration or dose of sodium stibogluconate therapy.These data suggest that pharmacological suppression of immune counterregulation using a commercially available drug originally developed for cancer therapy may have practical therapeutic utility in leishmaniasis. Rational reinvestigation of the efficacy of drugs approved for other indications in experimental models of neglected tropical diseases has promise in providing new candidates to the drug discovery pipeline.

Intraosseous osteolytic lesions

Energy Technology Data Exchange (ETDEWEB)

Adler, C.P.; Wenz, W.

1981-10-01

Any pathological damage occurring in a bone will produce either an osteolytic or osteosclerotic lesion which can be seen in the macroscopic specimen as well as in the roentgenogram. Various bone lesions may lead to local destructions of the bone. An osteoma or osteoplastic osteosarcoma produces an osteosclerotic lesion showing a dense mass in the roentgenogram; a chondroblastoma or an osteoclastoma, on the other hand, induces an osteolytic focal lesion. This paper presents examples of different osteolytic lesions of the humerus. An osteolytic lesion seen in the roentgenogram may be either produced by an underlying non-ossifying fibroma of the bone, by fibrous dysplasia, osteomyelitis or Ewing's sarcoma. Differential diagnostic considerations based on the radiological picture include eosinophilic bone granuloma, juvenile or aneurysmal bone cyst, multiple myeloma or bone metastases. Serious differential diagnostic problems may be involved in case of osteolytic lesions occurring in the humerus. Cases of this type involving complications have been reported and include the presence of an teleangiectatic osteosarcoma as well as that of a hemangiosarcoma of the bone.

Follow-up of bone lesions in an experimental multiple myeloma mouse model: Description of an in vivo technique using radiography dedicated for mammography

NARCIS (Netherlands)

Vanderkerken, K.; Goes, E.; Raeve, H. de; Radl, J.; Camp, B. van

1996-01-01

The evolution of bone lesions in transplantable C57BL/KaLwRij 5T mouse myeloma (MM) has been followed in vivo. Mice were anaesthetised and a radiograph of the pelvis and hind legs was performed by a radiograph dedicated for mammography. This is the first description of an in vivo technique under

Periodontal bone lesions

International Nuclear Information System (INIS)

Linden, L.W.J. van der.

1985-01-01

In the course of life the periodontum is subject to changes which may be physiological or pathological. Intraoral radiographs give insight into the hard structures of the dentomaxillar region and provides information on lesions in the bone of the periodontum in that they show radiopacities and radiolucencies caused by such lesions. In this thesis the relation is investigated between the true shape and dimensions of periodontal bone lesions and their radiographic images. A method is developed and tested of making standardized and reproducible radiographs suitable for longitudinal studies of periodontal lesions. Also the possibility is demonstrated of an objective and reproducible interpretation of radiographic characteristics of periodontal bone lesions. (Auth.)

Ibuprofen therapy resulted in significantly decreased tissue bacillary loads and increased survival in a new murine experimental model of active tuberculosis.

Science.gov (United States)

Vilaplana, Cristina; Marzo, Elena; Tapia, Gustavo; Diaz, Jorge; Garcia, Vanesa; Cardona, Pere-Joan

2013-07-15

C3HeB/FeJ mice infected with Mycobacterium tuberculosis were used in an experimental animal model mimicking active tuberculosis in humans to evaluate the effect of antiinflammatory agents. No other treatment but ibuprofen was given, and it was administered when the animals' health started to deteriorate. Animals treated with ibuprofen had statistically significant decreases in the size and number of lung lesions, decreases in the bacillary load, and improvements in survival, compared with findings for untreated animals. Because antiinflammatory agents are already on the market, further clinical trials should be done to evaluate this effect in humans as soon as possible, to determine their suitability as coadjuvant tuberculosis treatment.

Experimental modeling of injectivity loss; Modelagem experimental da perda de injetividade

Energy Technology Data Exchange (ETDEWEB)

Bonato, Adriano Jose do Amaral Mello; Silva, Pedro Glauto de Farias e; Gomes, Vanessa Limeira Azevedo; Santos, Adriano dos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2012-07-01

Produced water reinjection, suspended particles are retained in the porous media causing formation damage and injectivity decline. In general the retention of the particles occurs near the side of injection, this fact occurs in most cases, due to the size exclusion. The modeling of filtration and the consequent formation damage is essential to the project management of water injection in oil reservoirs. Thus, mathematical models are studied to better predict the distribution of particles throughout the porous media and determine the parameters of adjustment to injectivity decline. Among these models, there is the classic model which consists in determining these parameters (coefficient of filtration and formation damage). The methodology used in modeling is given from the equations the mass conservation, kinetic particle retention, the modified Darcy equation and the function formation damage. This study aimed to improve experimental modeling, including development of software for acquisition and processing of experimental data, considering the variable number of pressure measurements along the sample. The software was developed using the Labview 2011 platform and allows the determination of relevant parameters to predict injectivity loss in water injection wells. Furthermore, based on the traditional model of filtration in porous media (including depth filtration and formation of the external plaster), the software was applied to predict injectivity loss in addition to the properties of the grout. Finally, the classical models for transporting suspensions and damage to the formation were observed. (author)

Correlation of bistranded clustered abasic DNA lesion processing with structural and dynamic DNA helix distortion

Science.gov (United States)

Bignon, Emmanuelle; Gattuso, Hugo; Morell, Christophe; Dehez, François; Georgakilas, Alexandros G.; Monari, Antonio; Dumont, Elise

2016-01-01

Clustered apurinic/apyrimidinic (AP; abasic) DNA lesions produced by ionizing radiation are by far more cytotoxic than isolated AP lesion entities. The structure and dynamics of a series of seven 23-bp oligonucleotides featuring simple bistranded clustered damage sites, comprising of two AP sites, zero, one, three or five bases 3′ or 5′ apart from each other, were investigated through 400 ns explicit solvent molecular dynamics simulations. They provide representative structures of synthetically engineered multiply damage sites-containing oligonucleotides whose repair was investigated experimentally (Nucl. Acids Res. 2004, 32:5609-5620; Nucl. Acids Res. 2002, 30: 2800–2808). The inspection of extrahelical positioning of the AP sites, bulge and non Watson–Crick hydrogen bonding corroborates the experimental measurements of repair efficiencies by bacterial or human AP endonucleases Nfo and APE1, respectively. This study provides unprecedented knowledge into the structure and dynamics of clustered abasic DNA lesions, notably rationalizing the non-symmetry with respect to 3′ to 5′ position. In addition, it provides strong mechanistic insights and basis for future studies on the effects of clustered DNA damage on the recognition and processing of these lesions by bacterial or human DNA repair enzymes specialized in the processing of such lesions. PMID:27587587

The continuum of spreading depolarizations in acute cortical lesion development

DEFF Research Database (Denmark)

Hartings, Jed A; Shuttleworth, C William; Kirov, Sergei A

2017-01-01

A modern understanding of how cerebral cortical lesions develop after acute brain injury is based on Aristides Leão's historic discoveries of spreading depression and asphyxial/anoxic depolarization. Treated as separate entities for decades, we now appreciate that these events define a continuum....... The causal role of these waves in lesion development has been proven by real-time monitoring of electrophysiology, blood flow, and cytotoxic edema. The spreading depolarization continuum further applies to other models of acute cortical lesions, suggesting that it is a universal principle of cortical lesion...

Peritoneal macrophages mediated delivery of chitosan/siRNA nanoparticle to the lesion site in a murine radiation-induced fibrosis model

DEFF Research Database (Denmark)

Nawroth, Isabel; Alsner, Jan; Deleuran, B.W.

2013-01-01

of chitosan/siRNA nanoparticles directed towards silencing TNF alpha in local macrophage populations, but the mechanism for the therapeutic effect at the lesion site remains unclear. Methods. Using the same murine RIF model we utilized an optical imaging technique and fluorescence microscopy to investigate...... the uptake of chitosan/fluorescently labeled siRNA nanoparticles by peritoneal macrophages and their subsequent migration to the inflamed tissue in the RIF model. Results. We observed strong accumulation of the fluorescent signal in the lesion site of the irradiated leg up to 24 hours using the optical...... imaging system. We further confirm by immunohistochemical staining that Cy3 labeled siRNA resides in macrophages of the irradiated leg. Conclusion. We provide a proof-of-concept for host macrophage trafficking towards the inflamed region in a murine RIF model, which thereby suggests that the chitosan...

Endogenous opioid antagonism in physiological experimental pain models

DEFF Research Database (Denmark)

Werner, Mads U; Pereira, Manuel P; Andersen, Lars Peter H

2015-01-01

hyperalgesia models (6 studies), 'pain' models (25 studies), summation models (2 studies), nociceptive reflex models (3 studies) and miscellaneous models (2 studies). A consistent reversal of analgesia by a MOR-antagonist was demonstrated in 10 of the 25 ITP-studies, including stress-induced analgesia and r...... ratings, threshold assessments and somatosensory evoked potentials (SSEP), did not appear consistent in 28 out of 32 'pain' model studies. In conclusion, only in 2 experimental human pain models, i.e., stress-induced analgesia and rTMS, administration of MOR-antagonist demonstrated a consistent effect......Opioid antagonists are pharmacological tools applied as an indirect measure to detect activation of the endogenous opioid system (EOS) in experimental pain models. The objective of this systematic review was to examine the effect of mu-opioid-receptor (MOR) antagonists in placebo-controlled, double...

Optical Assessment of Caries Lesion Structure and Activity

Science.gov (United States)

Lee, Robert Chulsung

New, more sophisticated diagnostic tools are needed for the detection and characterization of caries lesions in the early stages of development. It is not sufficient to simply detect caries lesions, methods are needed to assess the activity of the lesion and determine if chemical or surgical intervention is needed. Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to nondestructively image the subsurface lesion structure and measure the thickness of the highly mineralized surface zone. Other studies have demonstrated that the rate of dehydration can be correlated with the lesion activity and that the rate can be measured using optical methods. The main objective of this work was to test the hypothesis that optical methods can be used to assess lesion activity on tooth coronal and root surfaces. Simulated caries models were used to develop and validate an algorithm for detecting and measuring the highly mineralized surface layer using PS-OCT. This work confirmed that the algorithm was capable of estimating the thickness of the highly mineralized surface layer with high accuracy. Near-infrared (NIR) reflectance and thermal imaging methods were used to assess activity of caries lesions by measuring the state of lesion hydration. NIR reflectance imaging performed the best for artificial enamel and natural coronal caries lesion samples, particularly at wavelengths coincident with the water absorption band at 1460-nm. However, thermal imaging performed the best for artificial dentin and natural root caries lesion samples. These novel optical methods outperformed the conventional methods (ICDAS II) in accurately assessing lesion activity of natural coronal and root caries lesions. Infrared-based imaging methods have shown potential for in-vivo applications to objectively assess caries lesion activity in a single examination. It is likely that if future clinical trials are a success, this novel imaging

Managing Carious Lesions

DEFF Research Database (Denmark)

Schwendicke, F; Frencken, J E; Bjørndal, L

2016-01-01

should be prioritized, while in shallow or moderately deep lesions, restoration longevity becomes more important. For teeth with shallow or moderately deep cavitated lesions, carious tissue removal is performed according toselective removal to firm dentine.In deep cavitated lesions in primary......The International Caries Consensus Collaboration undertook a consensus process and here presents clinical recommendations for carious tissue removal and managing cavitated carious lesions, including restoration, based on texture of demineralized dentine. Dentists should manage the disease dental...

EXPERIMENTAL MODEL OF THE PRIMARY MALE HYPOGONADISM

Directory of Open Access Journals (Sweden)

P. A. Kulikova

2014-01-01

Full Text Available Background: Development of the new methods of treatment of primary male hypogonadism is an urgent medical problem. Its solution requires a suitable experimental model of the disease. Aim: The creation of new experimental model of primary male hypogonadism. Materials and methods: The study was conducted on the male Wistar rats, hypogonadism was modeled by temporary ligation of the distal part of the spermatic cord. Results: It was shown that three-day ligation of the spermatic cord led to persistent disturbance of the testosterone-producing and reproductive functions. These manifestations were reversible at shorter duration of the exposure. Conclusion: The created model of primary male hypogonadism is characterized by the persistent testosterone-producing and reproductive functions disturbance, technical availability, non-toxicity to the other organs and systems. Availability of the model provides new opportunities for the development of approaches to treating diseases of the reproductive organs in men.

In vivo T2* weighted MRI visualizes cardiac lesions in murine models of acute and chronic viral myocarditis

Science.gov (United States)

Helluy, Xavier; Sauter, Martina; Ye, Yu-Xiang; Lykowsky, Gunthard; Kreutner, Jakob; Yilmaz, Ali; Jahns, Roland; Boivin, Valerie; Kandolf, Reinhard; Jakob, Peter M.; Hiller, Karl-Heinz; Klingel, Karin

2017-01-01

Objective Acute and chronic forms of myocarditis are mainly induced by virus infections. As a consequence of myocardial damage and inflammation dilated cardiomyopathy and chronic heart failure may develop. The gold standard for the diagnosis of myocarditis is endomyocardial biopsies which are required to determine the etiopathogenesis of cardiac inflammatory processes. However, new non-invasive MRI techniques hold great potential in visualizing cardiac non-ischemic inflammatory lesions at high spatial resolution, which could improve the investigation of the pathophysiology of viral myocarditis. Results Here we present the discovery of a novel endogenous T2* MRI contrast of myocardial lesions in murine models of acute and chronic CVB3 myocarditis. The evaluation of infected hearts ex vivo and in vivo by 3D T2w and T2*w MRI allowed direct localization of virus-induced myocardial lesions without any MRI tracer or contrast agent. T2*w weighted MRI is able to detect both small cardiac lesions of acute myocarditis and larger necrotic areas at later stages of chronic myocarditis, which was confirmed by spatial correlation of MRI hypointensity in myocardium with myocardial lesions histologically. Additional in vivo and ex vivo MRI analysis proved that the contrast mechanism was due to a strong paramagnetic tissue alteration in the vicinity of myocardial lesions, effectively pointing towards iron deposits as the primary contributor of contrast. The evaluation of the biological origin of the MR contrast by specific histological staining and transmission electron microscopy revealed that impaired iron metabolism primarily in mitochondria caused iron deposits within necrotic myocytes, which induces strong magnetic susceptibility in myocardial lesions and results in strong T2* contrast. Conclusion This T2*w MRI technique provides a fast and sensitive diagnostic tool to determine the patterns and the severity of acute and chronic enteroviral myocarditis and the precise

Understanding Leadership: An Experimental-Experiential Model

Science.gov (United States)

Hole, George T.

2014-01-01

Books about leadership are dangerous to readers who fantasize about being leaders or apply leadership ideas as if they were proven formulas. As an antidote, I offer an experimental framework in which any leadership-management model can be tested to gain experiential understanding of the model. As a result one can gain reality-based insights about…

Human papillomavirus in oral lesions Virus papiloma humano en lesiones orales

OpenAIRE

Joaquín V. Gónzalez; Rafael A. Gutiérrez; Alicia Keszler; Maria Del Carmen Colacino; Lidia V. Alonio; Angélica R. Teyssie; Maria Alejandra Picconi

2007-01-01

Growing evidence suggests a role for human papillomavirus (HPV) in oral cancer; however its involvement is still controversial. This study evaluates the frequency of HPV DNA in a variety of oral lesions in patients from Argentina. A total of 77 oral tissue samples from 66 patients were selected (cases); the clinical-histopathological diagnoses corresponded to: 11 HPV- associated benign lesions, 8 non-HPV associated benign lesions, 33 premalignant lesions and 25 cancers. Sixty exfoliated cell ...

Experimental Verification of the Transient Model in an Enrichment Circuit

International Nuclear Information System (INIS)

Fernandino, Maria; Brasnarof, Daniel; Delmastro, Dario

2003-01-01

In the present work an experimental closed loop representing a single stage of an uranium gaseous diffusion enrichment cascade is described, loop that is used to experimentally validate an analytical model that describes the dynamics inside such a loop.The conditions established inside the experimental loop after a few working hours were reproduced by the analytical model, leaving the slower thermal phenomena taking place for future studies.Two kinds of perturbations were experimentally introduced: a change in the range of operation of one of the compressors and the addition of mass into the loop.Numerical and experimental results are compared and presented in this work. The analytical model proposed was verified against these two changes, with very good agreement in the time response and measured values.This analytical model allows us to determine the characteristic time response of the system

Small brain lesions and incident stroke and mortality: A cohort study

Science.gov (United States)

Windham, B Gwen; Deere, Bradley; Griswold, Michael E.; Wang, Wanmei; Bezerra, Daniel C; Shibata, Dean; Butler, Kenneth; Knopman, David; Gottesman, Rebecca F; Heiss, Gerardo; Mosley, Thomas H

2015-01-01

Background Although cerebral lesions ≥3mm on imaging are associated with incident stroke, lesions stroke risks associated with subclinical brain lesions by size (stroke; average 14.5 years follow-up. Measurements MRI lesions: none (n=1611), stroke (n=157), overall mortality (n=576), stroke mortality (n=50). Hazard Ratios (HR) estimated with proportional hazards models. Results Compared to no lesions, stroke risk was tripled with lesions Stroke risk doubled with WMH ≥3 (HR=2.14, 95% CI:1.45-3.16). Stroke mortality risk tripled with lesions stroke events (n=147), especially hemorrhagic (n=15); limited numbers of participants with only lesions ≤3mm (n=50) or with both lesions ≤3mm and 3–20mm (n=35). Conclusions Very small cerebrovascular lesions may be associated with increased risks of stroke and mortality; having both < 3 mm and ≥3 mm lesions may represent a particularly striking risk increase. Larger studies are needed to confirm findings and provide more precise estimates. PMID:26148278

Classification of multiple sclerosis lesions using adaptive dictionary learning.

Science.gov (United States)

Deshpande, Hrishikesh; Maurel, Pierre; Barillot, Christian

2015-12-01

This paper presents a sparse representation and an adaptive dictionary learning based method for automated classification of multiple sclerosis (MS) lesions in magnetic resonance (MR) images. Manual delineation of MS lesions is a time-consuming task, requiring neuroradiology experts to analyze huge volume of MR data. This, in addition to the high intra- and inter-observer variability necessitates the requirement of automated MS lesion classification methods. Among many image representation models and classification methods that can be used for such purpose, we investigate the use of sparse modeling. In the recent years, sparse representation has evolved as a tool in modeling data using a few basis elements of an over-complete dictionary and has found applications in many image processing tasks including classification. We propose a supervised classification approach by learning dictionaries specific to the lesions and individual healthy brain tissues, which include white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF). The size of the dictionaries learned for each class plays a major role in data representation but it is an even more crucial element in the case of competitive classification. Our approach adapts the size of the dictionary for each class, depending on the complexity of the underlying data. The algorithm is validated using 52 multi-sequence MR images acquired from 13 MS patients. The results demonstrate the effectiveness of our approach in MS lesion classification. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of a high-fat diet and alcohol on cutaneous repair: A systematic review of murine experimental models.

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Daiane Figueiredo Rosa

Full Text Available Chronic alcohol intake associated with an inappropriate diet can cause lesions in multiple organs and tissues and complicate the tissue repair process. In a systematic review, we analyzed the relevance of alcohol and high fat consumption to cutaneous and repair, compared the main methodologies used and the most important parameters tested. Preclinical investigations with murine models were assessed to analyze whether the current evidence support clinical trials.The studies were selected from MEDLINE/PubMed and Scopus databases, according to Fig 1. All 15 identified articles had their data extracted. The reporting bias was investigated according to the ARRIVE (Animal Research: Reporting of in Vivo Experiments strategy.In general, animals offered a high-fat diet and alcohol showed decreased cutaneous wound closure, delayed skin contraction, chronic inflammation and incomplete re-epithelialization.In further studies, standardized experimental design is needed to establish comparable study groups and advance the overall knowledge background, facilitating data translatability from animal models to human clinical conditions.

Models of experimental saccular aneurysms of carotid arteries in canine

International Nuclear Information System (INIS)

Zhang Haixia; Cheng Yingsheng; Li Minghua

2006-01-01

Objective: To study the availability by making experimental saccular aneurysm models of carotid arteries in canine similar to human intracranial aneurysms. Methods: Twenty healthy canines with experimental saccular side-wall aneurysms of carotid arteries were created successfully by surgery. Results: Forty experimental saccular side-wall aneurysms of carotid arteries were created successfully with 36 aneurysms and parent arteries maintaining patency with each other and four spontaneously occluded confirmed by angiography. Model successful rate reached 90%. Conclusions: Experimental saccular side-wall aneurysms of carotid arteries in canines were one of best models created for simulating human intracranial aneurysms. (authors)

A sEMG model with experimentally based simulation parameters.

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Wheeler, Katherine A; Shimada, Hiroshima; Kumar, Dinesh K; Arjunan, Sridhar P

2010-01-01

A differential, time-invariant, surface electromyogram (sEMG) model has been implemented. While it is based on existing EMG models, the novelty of this implementation is that it assigns more accurate distributions of variables to create realistic motor unit (MU) characteristics. Variables such as muscle fibre conduction velocity, jitter (the change in the interpulse interval between subsequent action potential firings) and motor unit size have been considered to follow normal distributions about an experimentally obtained mean. In addition, motor unit firing frequencies have been considered to have non-linear and type based distributions that are in accordance with experimental results. Motor unit recruitment thresholds have been considered to be related to the MU type. The model has been used to simulate single channel differential sEMG signals from voluntary, isometric contractions of the biceps brachii muscle. The model has been experimentally verified by conducting experiments on three subjects. Comparison between simulated signals and experimental recordings shows that the Root Mean Square (RMS) increases linearly with force in both cases. The simulated signals also show similar values and rates of change of RMS to the experimental signals.

[The theory of cardiac lesions from blunt chest injury].

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Tumanov, E V; Sokolova, Z Iu

2010-01-01

The main theories of myocardial lesions associated with a blunt chest injury proposed starting from the XIXth century till the present time are considered based on the overview of the literature data. It is shown that the theory of selective mechanical activation of ATP-dependent K+ channels is most promising for further investigations into the mechanisms of myocardial dysfunction resulting from blunt chest injuries. The authors emphasize the absence of the universally accepted theory explaining the mechanism behind traumatic cardiac troubles and its fatal outcome despite numerous studies of cardiac lesions in patients with a blunt chest injury. It dictates the necessity of further research, both clinical and experimental, for a deeper insight into the problem.

Adjustment model of thermoluminescence experimental data

International Nuclear Information System (INIS)

Moreno y Moreno, A.; Moreno B, A.

2002-01-01

This model adjusts the experimental results for thermoluminescence according to the equation: I (T) = I (a i * exp (-1/b i * (T-C i )) where: a i , b i , c i are the i-Th peak adjusted to a gaussian curve. The adjustments of the curve can be operated manual or analytically using the macro function and the solver.xla complement installed previously in the computational system. In this work it is shown: 1. The information of experimental data from a LiF curve obtained from the Physics Institute of UNAM which the data adjustment model is operated in the macro type. 2. A LiF curve of four peaks obtained from Harshaw information simulated in Microsoft Excel, discussed in previous works, as a reference not in macro. (Author)

Evaluated experimental database on critical heat flux in WWER FA models

International Nuclear Information System (INIS)

Artamonov, S.; Sergeev, V.; Volkov, S.

2015-01-01

The paper presents the description of the evaluated experimental database on critical heat flux in WWER FA models of new designs. This database was developed on the basis of the experimental data obtained in the years of 2009-2012. In the course of its development, the database was reviewed in terms of completeness of the information about the experiments and its compliance with the requirements of Rostekhnadzor regulatory documents. The description of the experimental FA model characteristics and experimental conditions was specified. Besides, the experimental data were statistically processed with the aim to reject incorrect ones and the sets of experimental data on critical heat fluxes (CHF) were compared for different FA models. As a result, for the fi rst time, the evaluated database on CHF in FA models of new designs was developed, that was complemented with analysis functions, and its main purpose is to be used in the process of development, verification and upgrading of calculation techniques. The developed database incorporates the data of 4183 experimental conditions obtained in 53 WWER FA models of various designs. Keywords: WWER reactor, fuel assembly, CHF, evaluated experimental data, database, statistical analysis. (author)

Incidence of Acneform Lesions in Previously Chemically Damaged Persons-2004

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N Dabiri

2008-04-01

Full Text Available ABSTRACT: Introduction & Objective: Chemical gas weapons especially nitrogen mustard which was used in Iraq-Iran war against Iranian troops have several harmful effects on skin. Some other chemical agents also can cause acne form lesions on skin. The purpose of this study was to compare the incidence of acneform in previously chemically damaged soldiers and non chemically damaged persons. Materials & Methods: In this descriptive and analytical study, 180 chemically damaged soldiers, who have been referred to dermatology clinic between 2000 – 2004, and forty non-chemically damaged people, were chosen randomly and examined for acneform lesions. SPSS software was used for statistic analysis of the data. Results: The mean age of the experimental group was 37.5 ± 5.2 and that of the control group was 38.7 ± 5.9 years. The mean percentage of chemical damage in cases was 31 percent and the time after the chemical damage was 15.2 ± 1.1 years. Ninety seven cases (53.9 percent of the subjects and 19 people (47.5 percent of the control group had some degree of acne. No significant correlation was found in incidence, degree of lesions, site of lesions and age of subjects between two groups. No significant correlation was noted between percentage of chemical damage and incidence and degree of lesions in case group. Conclusion: Incidence of acneform lesions among previously chemically injured peoples was not higher than the normal cases.

Lateral and Anterior Thalamic Lesions Impair Independent Memory Systems

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Mitchell, Anna S.; Dalrymple-Alford, John C.

2006-01-01

Damage to the medial region of the thalamus, both in clinical cases (e.g., patients with infarcts or the Korsakoff's syndrome) and animal lesion models, is associated with variable amnesic deficits. Some studies suggest that many of these memory deficits rely on the presence of lateral thalamic lesions (LT) that include the intralaminar nuclei,…

Experimental phantom lesion detectability study using a digital breast tomosynthesis prototype system

International Nuclear Information System (INIS)

Schulz-Wendtland, R.; Wenkel, E.; Lell, M.; Boehner, C.; Bautz, W.A.; Mertelmeier, T.

2006-01-01

Purpose: To compare the sensitivity of conventional two-dimensional (2D) projection imaging with tomosynthesis with respect to the detectability of mammographic phantom lesions. Materials and Methods: Using a breast tomosynthesis prototype based on a commercial FFDM system (Siemens MAMMOMAT Novation DR ), but modified for a wide angle tube motion and equipped with a fast read-out amorphous selenium detector, we acquired standard 2D images and tomosynthesis series of projection views. We used the Wisconsin mammographic random phantom, model RMI 152A. The anode filter combinations Mo/Mo and W/Rh at two different doses were used as typical radiographic techniques. Slice images through the phantom parallel to the detector were reconstructed with a distance of 1 mm employing a filtered back-projection algorithm. The image data sets were read by five radiologists and evaluated with respect to the detectability of the phantom details. Results: For all studied radiographic techniques, the detection rate in the tomosynthesis mode was 100%, i.e. 75 true positive findings out of 75 possible hits. In contrast, the conventional projection mode yielded a detection rate between 80 and 93% (corresponding to 60 and 70 detected details) depending on the dose and X-ray spectrum. Conclusion: Tomosynthesis has the potential to increase the sensitivity of digital mammography. Overlapping structures from out-of-plane tissue can be removed in the tomosynthesis reconstruction process, thereby enhancing the diagnostic accuracy. (orig.)

Pathogen translocation and histopathological lesions in an experimental model of Salmonella Dublin infection in calves receiving lactic acid bacteria and lactose supplements

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Zbrun, María V.; Soto, Lorena P.; Bertozzi, Ezequiel; Sequeira, Gabriel J.; Marti, Luis E.; Signorini, Marcelo L.; Armesto, Roberto Rodríguez; Rosmini, Marcelo R.

2012-01-01

The purpose of this study was to evaluate the capacity of a lactic acid bacteria (LAB) inoculum to protect calves with or without lactose supplements against Salmonella Dublin infection by evaluating histopathological lesions and pathogen translocation. Fifteen calves were divided into three groups [control group (C-G), a group inoculated with LAB (LAB-G), and a group inoculated with LAB and given lactose supplements (L-LAB-G)] with five, six, and four animals, respectively. The inoculum, composed of Lactobacillus (L.) casei DSPV 318T, L. salivarius DSPV 315T, and Pediococcus acidilactici DSPV 006T, was administered with milk replacer. The LAB-G and L-LAB-G received a daily dose of 109 CFU/kg body weight of each strain throughout the experiment. Lactose was provided to the L-LAB-G in doses of 100 g/day. Salmonella Dublin (2 × 1010 CFU) was orally administered to all animals on day 11 of the experiment. The microscopic lesion index values in target organs were 83%, 70%, and 64.3% (p < 0.05) for the C-G, LAB-G, and L-LAB-G, respectively. Administration of the probiotic inoculum was not fully effective against infection caused by Salmonella. Although probiotic treatment was unable to delay the arrival of pathogen to target organs, it was evident that the inoculum altered the response of animals against pathogen infection. PMID:23000583

Benign fibroosseous lesions

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Cansu Köseoğlu Seçgin

2016-05-01

Full Text Available Benign fibroosseous lesions represent a group of lesions that share the same basic evolutive mechanism and are characterized by replacement of normal bone with a fibrous connective tissue that gradually undergoes mineralization. These lesions are presented by a variety of diseases including developmental, reactive-dysplastic processes and neoplasms. Depending on the nature and amount of calcified tissue, they can be observed as radiolucent, mixed or radiopaque. Their radiographic features could be well-defined or indistinguishable from the surrounding bone tissue. They can be asymptomatic as in osseous dysplasias and can be detected incidentally on radiographs, or they can lead to expansion in the affected bone as in ossifying fibroma. All fibroosseous lesions seen in the jaws and face are variations of the same histological pattern. Therefore, detailed clinical and radiographic evaluation in differential diagnosis is important. In this review, fibroosseous benign lesions are classified as osseous dysplasia, fibrous dysplasia and fibroosseous tumors; and radiographic features and differential diagnosis of these lesions are reviewed taking into account this classification.

Metatranscriptomics reveals overall active bacterial composition in caries lesions

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Aurea Simón-Soro

2014-10-01

Full Text Available Background: Identifying the microbial species in caries lesions is instrumental to determine the etiology of dental caries. However, a significant proportion of bacteria in carious lesions have not been cultured, and the use of molecular methods has been limited to DNA-based approaches, which detect both active and inactive or dead microorganisms. Objective: To identify the RNA-based, metabolically active bacterial composition of caries lesions at different stages of disease progression in order to provide a list of potential etiological agents of tooth decay. Design: Non-cavitated enamel caries lesions (n=15 and dentin caries lesions samples (n=12 were collected from 13 individuals. RNA was extracted and cDNA was constructed, which was used to amplify the 16S rRNA gene. The resulting 780 bp polymerase chain reaction products were pyrosequenced using Titanium-plus chemistry, and the sequences obtained were used to determine the bacterial composition. Results: A mean of 4,900 sequences of the 16S rRNA gene with an average read length of 661 bp was obtained per sample, giving a comprehensive view of the active bacterial communities in caries lesions. Estimates of bacterial diversity indicate that the microbiota of cavities is highly complex, each sample containing between 70 and 400 metabolically active species. The composition of these bacterial consortia varied among individuals and between caries lesions of the same individuals. In addition, enamel and dentin lesions had a different bacterial makeup. Lactobacilli were found almost exclusively in dentin cavities. Streptococci accounted for 40% of the total active community in enamel caries, and 20% in dentin caries. However, Streptococcus mutans represented only 0.02–0.73% of the total bacterial community. Conclusions: The data indicate that the etiology of dental caries is tissue dependent and that the disease has a clear polymicrobial origin. The low proportion of mutans streptococci

PPARα activation differently affects microparticle content in atherosclerotic lesions and liver of a mouse model of atherosclerosis and NASH.

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Baron, Morgane; Leroyer, Aurélie S; Majd, Zouher; Lalloyer, Fanny; Vallez, Emmanuelle; Bantubungi, Kadiombo; Chinetti-Gbaguidi, Giulia; Delerive, Philippe; Boulanger, Chantal M; Staels, Bart; Tailleux, Anne

2011-09-01

Atherosclerosis and non-alcoholic fatty liver disease (NAFLD) are complex pathologies characterized by lipid accumulation, chronic inflammation and extensive tissue remodelling. Microparticles (MPs), small membrane vesicles produced by activated and apoptotic cells, might not only be biomarkers, but also functional actors in these pathologies. The apoE2-KI mouse is a model of atherosclerosis and NAFLD. Activation of the nuclear receptor PPARα decreases atherosclerosis and components of non-alcoholic steatohepatitis (NASH) in the apoE2-KI mouse. (1) To determine whether MPs are present in atherosclerotic lesions, liver and plasma during atherosclerosis and NASH progression in apoE2-KI mice, and (2) to study whether PPARα activation modulates MP concentrations. ApoE2-KI mice were fed a Western diet to induce atherosclerosis and NASH. MPs were isolated from atherosclerotic lesions, liver and blood and quantified by flow cytometry. An increase of MPs was observed in the atherosclerotic lesions and in the liver of apoE2-KI mice upon Western diet feeding. PPARα activation with fenofibrate decreased MP levels in the atherosclerotic lesions in a PPARα-dependent manner, but did not influence MP concentrations in the liver. Here we report that MPs are present in atherosclerotic lesions and in the liver of apoE2-KI mice. Their concentration increased during atherosclerosis and NASH development. PPARα activation differentially modulates MP levels in a tissue-specific manner. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Removal of focal atheromatous lesions by angioscopically guided high-speed rotary atherectomy. Preliminary experimental observations

International Nuclear Information System (INIS)

Ahn, S.S.; Auth, D.; Marcus, D.R.; Moore, W.S.

1988-01-01

A new high-speed rotary atherectomy device, inserted over a guide wire and directed with an angioscope, offers the potential of restoring patency of outflow vessels by boring out the atheromatous lesion of the orifices of runoff vessels. The device was tested on 68 cadaver arteries with atheromatous lesions involving the superficial femoral, popliteal, and tibial arteries. This was performed with either free segments or in situ with the device placed through a popliteal arteriotomy. The gross results of rotary atherectomy were assessed by angioscopy, angiography, or both. The luminal surfaces were studied with scanning electron microscopy and transverse sections of vessels were studied with light microscopy. The pulverized atheroma, in colloidal suspension, was analyzed for particle size by Coulter counter. The effect of a colloidal suspension of atheromatous particles on distal capillary circulation was measured in animal experiments. Obstructive lesions were successfully removed in 36 of 37 stenotic arteries (97%) and 18 of 31 completely occluded arteries (58%), an overall efficacy of 54 of 68 (79%). In successfully atherectomized arteries, angioscopy and angiography demonstrated a widely patent, smooth, polished surface. Light microscopy demonstrated removal of the diseased intima with maintenance of the outer media and adventitia. The pulverized atheroma particles were generally smaller than red blood cells and injection of the colloidal atheroma into canine femoral arteries failed to produce local tissue injury. We conclude that in the human cadaver this atherectomy device effectively enlarges and recanalizes obstructed superficial femoral, popliteal, and tibial arteries

The effects of neonatal amygdala or hippocampus lesions on adult social behavior.

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Bliss-Moreau, Eliza; Moadab, Gilda; Santistevan, Anthony; Amaral, David G

2017-03-30

The present report details the final phase of a longitudinal evaluation of the social behavior in a cohort of adult rhesus monkeys that received bilateral neurotoxic lesions of the amygdala or hippocampus, or sham operations at 2 weeks of age. Results were compared to previous studies in which adult animals received amygdala lesions and were tested in a similar fashion. Social testing with four novel interaction partners occurred when the animals were between 7 and 8 years of age. Experimental animals interacted with two male and two female partners in two conditions - one in which physical access was restricted (the constrained social access condition) and a second in which physical access was unrestricted (the unconstrained social access condition). Across conditions and interaction partners, there were no significant effects of lesion condition on the frequency or duration of social interactions. As a group, the hippocampus-lesioned animals generated the greatest number of communicative signals during the constrained social access condition. Amygdala-lesioned animals generated more frequent stress-related behaviors and were less exploratory. Amygdala and hippocampus-lesioned animals demonstrated greater numbers of stereotypies than control animals. Subtle, lesion-based differences in the sequencing of behaviors were observed. These findings suggest that alterations of adult social behavior are much less prominent when damage to the amygdala occurs early in life rather than in adulthood. Copyright © 2016 Elsevier B.V. All rights reserved.

After facial nerve damage, regenerating axons become aberrant throughout the length of the nerve and not only at the site of the lesion: an experimental study.

Science.gov (United States)

Choi, D; Raisman, G

2004-02-01

After facial nerve trauma, aberrant regeneration is associated with synkinesis. Animal models of mechanical nerve guides or reparative cell transplants at the site of a lesion have not been shown to improve disorganized regeneration. We examined whether this is because regenerating axons become disorganized throughout the length of the nerve and not only at the site of the lesion. In rats (n = 12), retrograde fluorescent tracer techniques were used to establish that most of the temporal branch fibres were carried in the superior half of the facial nerve trunk. In two further groups of rats (n = 24) a complete proximal facial nerve lesion was made, and the nerve immediately repaired by suture. After 4 weeks, at a second operation, the superior half of the facial nerve trunk was cut, either proximal or distal to the original lesion, and retrograde tracers were applied to distal branches of the nerve. It was possible to localize the points at which regenerating fibres became aberrant in their course by studying the number of labelled motoneurons in the facial nucleus after application of the tracer to the temporal branch of the nerve: this was similar in the distal and proximal hemisection groups, suggesting that aberrant axonal development occurred throughout the length of the nerve. Future strategies aimed at improving the organization of regeneration need to provide guidance cues not only at the site of the lesion as previously thought, but also throughout the length of the nerve.

The potential cost-effectiveness of the Diamondback 360® Coronary Orbital Atherectomy System for treating de novo, severely calcified coronary lesions: an economic modeling approach.

Science.gov (United States)

Chambers, Jeffrey; Généreux, Philippe; Lee, Arthur; Lewin, Jack; Young, Christopher; Crittendon, Janna; Mann, Marita; Garrison, Louis P

2016-04-01

Patients who undergo percutaneous coronary intervention (PCI) for severely calcified coronary lesions have long been known to have worse clinical and economic outcomes than patients with no or mildly calcified lesions. We sought to assess the likely cost-effectiveness of using the Diamondback 360(®) Orbital Atherectomy System (OAS) in the treatment of de novo, severely calcified lesions from a health-system perspective. In the absence of a head-to-head trial and long-term follow up, cost-effectiveness was based on a modeled synthesis of clinical and economic data. A cost-effectiveness model was used to project the likely economic impact. To estimate the net cost impact, the cost of using the OAS technology in elderly (⩾ 65 years) Medicare patients with de novo severely calcified lesions was compared with cost offsets. Elderly OAS patients from the ORBIT II trial (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) [ClinicalTrials.gov identifier: NCT01092426] were indirectly compared with similar patients using observational data. For the index procedure, the comparison was with Medicare data, and for both revascularization and cardiac death in the following year, the comparison was with a pooled analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI)/Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trials. After adjusting for differences in age, gender, and comorbidities, the ORBIT II mean index procedure costs were 17% (p economic modeling, the recently approved coronary OAS device is projected to be highly cost-effective for patients who undergo PCI for severely calcified lesions. © The Author(s), 2015.

Lesions of juxtacortical origin (surface lesions of bone)

International Nuclear Information System (INIS)

Kenan, S.; Abdelwahab, I.F.; Klein, M.J.; Hermann, G.; Lewis, M.M.

1993-01-01

A large variety of tumor and tumor-like conditions have been shown to originate from the surface of bone. Most surface lesions are associated with periosteal reaction. The periosteum is a multipotential membrane. Its cellular composition may give rise to a variety of both neoplasms and tumor-like conditions. To avoid misinterpretation, the orthopedist, radiologist, and pathologist should be familiar with the entire spectrum of surface lesions. A better understanding of the natural history and biological behavior at different lesional maturity stages and correlation of the history with the radiographic and pathological findings is essential to establish the correct diagnosis. A history of injury of blunt trauma is very important. A stress fracture may produce a periosteal reaction acd callus that can be difficult to distinguish from osteosarcoma. In this review article, the authors wish to describe and define each term by its anatomy and radiographic features while discussing the entire spectrum of surface lesions. All the illustrative cases in this review article have been proven histologically. (orig.)

Maxillary Bone Regeneration Based on Nanoreservoirs Functionalized ε-Polycaprolactone Biomembranes in a Mouse Model of Jaw Bone Lesion

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Marion Strub

2018-01-01

Full Text Available Current approaches of regenerative therapies constitute strategies for bone tissue reparation and engineering, especially in the context of genetical diseases with skeletal defects. Bone regeneration using electrospun nanofibers’ implant has the following objectives: bone neoformation induction with rapid healing, reduced postoperative complications, and improvement of bone tissue quality. In vivo implantation of polycaprolactone (PCL biomembrane functionalized with BMP-2/Ibuprofen in mouse maxillary defects was followed by bone neoformation kinetics evaluation using microcomputed tomography. Wild-Type (WT and Tabby (Ta mice were used to compare effects on a normal phenotype and on a mutant model of ectodermal dysplasia (ED. After 21 days, no effect on bone neoformation was observed in Ta treated lesion (4% neoformation compared to 13% in the control lesion. Between the 21st and the 30th days, the use of biomembrane functionalized with BMP-2/Ibuprofen in maxillary bone lesions allowed a significant increase in bone neoformation peaks (resp., +8% in mutant Ta and +13% in WT. Histological analyses revealed a neoformed bone with regular trabecular structure, areas of mineralized bone inside the membrane, and an improved neovascularization in the treated lesion with bifunctionalized membrane. In conclusion, PCL functionalized biomembrane promoted bone neoformation, this effect being modulated by the Ta bone phenotype responsible for an alteration of bone response.

Production of lesions in rabbit spinal cord with microwave hyperthermia

International Nuclear Information System (INIS)

Sutton, C.H.; Popovic, P.

1984-01-01

The use of a variety of injury models in different species to produce spinal cord lesions by trauma or ischemia has often given rise to conflicting or inconclusive data. A new model has been developed in rabbits. Spinal cord lesions were produced in selected spinal cord segments of male New Zealand white rabbits by non-invasive irradiation with microwaves in the near field at 915 MHz. Graded injuries of predictable severity can be produced by the non-invasive induction of moderate hyperthermia in the thoracic spinal cord at precise dosage levels of temperature elevation and duration. Histological changes in microwave-induced hyperthermia closely parallel those seen in traumatic lesions of the human spinal cord, as well as those produced in animals with the classical weight-drop method of Allen. In addition to grading the spinal cord lesions with respect to residual neurological function, dose-response observations made with somatosensory evoked responses, blood-spinal cord barrier tracers, and neurohistological and enzyme histochemical preparations, suggest that it will be possible to use this approach to develop a standardized, calibrated model in rabbits to evaluate the efficacy of new therapeutic modalities for the treatment of spinal cord injury

The experimental and shell model approach to 100Sn

International Nuclear Information System (INIS)

Grawe, H.; Maier, K.H.; Fitzgerald, J.B.; Heese, J.; Spohr, K.; Schubart, R.; Gorska, M.; Rejmund, M.

1995-01-01

The present status of experimental approach to 100 Sn and its shell model structure is given. New developments in experimental techniques, such as low background isomer spectroscopy and charged particle detection in 4π are surveyed. Based on recent experimental data shell model calculations are used to predict the structure of the single- and two-nucleon neighbours of 100 Sn. The results are compared to the systematic of Coulomb energies and spin-orbit splitting and discussed with respect to future experiments. (author). 51 refs, 11 figs, 1 tab

Mutant mice: experimental organisms as materialised models in biomedicine.

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Huber, Lara; Keuck, Lara K

2013-09-01

Animal models have received particular attention as key examples of material models. In this paper, we argue that the specificities of establishing animal models-acknowledging their status as living beings and as epistemological tools-necessitate a more complex account of animal models as materialised models. This becomes particularly evident in animal-based models of diseases that only occur in humans: in these cases, the representational relation between animal model and human patient needs to be generated and validated. The first part of this paper presents an account of how disease-specific animal models are established by drawing on the example of transgenic mice models for Alzheimer's disease. We will introduce an account of validation that involves a three-fold process including (1) from human being to experimental organism; (2) from experimental organism to animal model; and (3) from animal model to human patient. This process draws upon clinical relevance as much as scientific practices and results in disease-specific, yet incomplete, animal models. The second part of this paper argues that the incompleteness of models can be described in terms of multi-level abstractions. We qualify this notion by pointing to different experimental techniques and targets of modelling, which give rise to a plurality of models for a specific disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Experimental models of hepatotoxicity related to acute liver failure

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Maes, Michaël [Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels (Belgium); Vinken, Mathieu, E-mail: mvinken@vub.ac.be [Department of In Vitro Toxicology and Dermato-Cosmetology, Vrije Universiteit Brussel, Brussels (Belgium); Jaeschke, Hartmut [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City (United States)

2016-01-01

Acute liver failure can be the consequence of various etiologies, with most cases arising from drug-induced hepatotoxicity in Western countries. Despite advances in this field, the management of acute liver failure continues to be one of the most challenging problems in clinical medicine. The availability of adequate experimental models is of crucial importance to provide a better understanding of this condition and to allow identification of novel drug targets, testing the efficacy of new therapeutic interventions and acting as models for assessing mechanisms of toxicity. Experimental models of hepatotoxicity related to acute liver failure rely on surgical procedures, chemical exposure or viral infection. Each of these models has a number of strengths and weaknesses. This paper specifically reviews commonly used chemical in vivo and in vitro models of hepatotoxicity associated with acute liver failure. - Highlights: • The murine APAP model is very close to what is observed in patients. • The Gal/ET model is useful to study TNFα-mediated apoptotic signaling mechanisms. • Fas receptor activation is an effective model of apoptosis and secondary necrosis. • The ConA model is a relevant model of auto-immune hepatitis and viral hepatitis. • Multiple time point evaluation needed in experimental models of acute liver injury.

Differential Impairment of Noun and Verb Consequent to LH Lesions in Persian Aphasic Patients

OpenAIRE

Dr. Reza Nilipour; Rabeeh Ariaei; Dr. Hassan Ashayeri

2003-01-01

The major focus of this research is on the differential disruption of language abilities subsequent to brain damages as they relate to site and size of lesion, especially left hemisphere lesions which disrupt the production and processing of "Nouns" vs. "Verbs" as two functionally different lexical categories. Several clinical as well as experimental studies reported on different language have shown that nouns and verbs can be independently disrupted due to brain damage. A prevalent impairmen...

Development of experimental alloxan model of diabetes mellitus

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V.V. Semenko

2017-05-01

Full Text Available Background. One of the main causes that lead to the disability of diabetic patients is diabetic retinopathy (DR. The relevance of the problem of DR necessitates the development of optimal experimental models on experimental animals to find effective ways of correcting this pathology. The purpose of our work was to develop an experimental alloxan model of type 1 diabetes mellitus (DM for the study of DR, which would not result in the lethal outcome of experimental animals under the action of alloxan; histological examination of changes in the tissues of the eyeball in the reproduction of the DM model for the selection of new effective methods for the metabolic treatment of DR in the early stages. Materials and methods. The experiment was carried out on white outbred Wistar rats weighing 180–200 g. The first group consisted of 20 animals that were not subjected to any influence, served as a control; second group — 30 animals, in which DM was modeled by administration of alloxan and fructose. Results. When modeling DR, vessel changes in the form of wall fibrosis, edema of the endothelium and vasospasm were found. There was also a decrease in the amount of pigment granules, dystrophic changes in the cells of the ganglionic layer and a layer of retinal rods and cones, which coincides with the descriptions of damage to the coats of the eyeball in patients with DM. Conclusions. In our studies, we have calculated the optimal dose of alloxan administration, which does not lead to the death of rats (the lethality of rats was absent and is an effective model not only of DM in general, but also of DR.

Quantification of osteolytic bone lesions in a preclinical rat trial

Science.gov (United States)

Fränzle, Andrea; Bretschi, Maren; Bäuerle, Tobias; Giske, Kristina; Hillengass, Jens; Bendl, Rolf

2013-10-01

In breast cancer, most of the patients who died, have developed bone metastasis as disease progression. Bone metastases in case of breast cancer are mainly bone destructive (osteolytic). To understand pathogenesis and to analyse response to different treatments, animal models, in our case rats, are examined. For assessment of treatment response to bone remodelling therapies exact segmentations of osteolytic lesions are needed. Manual segmentations are not only time-consuming but lack in reproducibility. Computerized segmentation tools are essential. In this paper we present an approach for the computerized quantification of osteolytic lesion volumes using a comparison to a healthy reference model. The presented qualitative and quantitative evaluation of the reconstructed bone volumes show, that the automatically segmented lesion volumes complete missing bone in a reasonable way.

Generative adversarial networks for brain lesion detection

Science.gov (United States)

Alex, Varghese; Safwan, K. P. Mohammed; Chennamsetty, Sai Saketh; Krishnamurthi, Ganapathy

2017-02-01

Manual segmentation of brain lesions from Magnetic Resonance Images (MRI) is cumbersome and introduces errors due to inter-rater variability. This paper introduces a semi-supervised technique for detection of brain lesion from MRI using Generative Adversarial Networks (GANs). GANs comprises of a Generator network and a Discriminator network which are trained simultaneously with the objective of one bettering the other. The networks were trained using non lesion patches (n=13,000) from 4 different MR sequences. The network was trained on BraTS dataset and patches were extracted from regions excluding tumor region. The Generator network generates data by modeling the underlying probability distribution of the training data, (PData). The Discriminator learns the posterior probability P (Label Data) by classifying training data and generated data as "Real" or "Fake" respectively. The Generator upon learning the joint distribution, produces images/patches such that the performance of the Discriminator on them are random, i.e. P (Label Data = GeneratedData) = 0.5. During testing, the Discriminator assigns posterior probability values close to 0.5 for patches from non lesion regions, while patches centered on lesion arise from a different distribution (PLesion) and hence are assigned lower posterior probability value by the Discriminator. On the test set (n=14), the proposed technique achieves whole tumor dice score of 0.69, sensitivity of 91% and specificity of 59%. Additionally the generator network was capable of generating non lesion patches from various MR sequences.

Localization of lesions in aphasia

International Nuclear Information System (INIS)

Hojo, Kei; Watanabe, Shunzo; Tasaki, Hiroichi; Sato, Tokijiro; Metoki, Hirobumi.

1984-01-01

Using a microcomputer, the locus and extent of the lesions, as demonstrated by computed tomography for 127 cases with various types of aphasia were superimposed onto standardized marices. The relationship between the foci of the lesions and the types of aphasia was investigated. Broca aphasics (n=39) : Since the accumulated site of the lesions highly involved the deep structures of the lower part of the precentral gyrus as well as the insula and lenticular nucleus, only 60% of the Broca aphasics had lesions on these areas. This finding has proved to have little localizing value. Wernicke aphasics (n=23) : The size of the lesion was significantly smaller than Broca's aphasia. At least 70% of the patients had the superior temporal lesions involving Wernicke's area and subcortical lesions of the superior and middle temporal gyri. Amnestic aphasics (n=18) : The size of the lesion was smaller than any other types. While there was some concentration of the lesions (maximum 40%) in the area of the subcortical region of the anterior temporal gyrus adjacent to Wernicke's area and the lenticular nucleus, the lesions were distributed throughout the left hemisphere. Amnestic aphasia was thought to be the least localizable. Conduction aphasics (n=11) : The lesions were relatively small in size. Many patients had posterior speech area lesions involving at least partially Wernicke's area. In particular, more than 80% of the conduction aphasics had lesions of the supramarginal gyrus and it's adjacent deep structures. Global aphasics (n=36) : In general, the size of the lesion was very large and 70% of the global aphasics had extensive lesions involving both Broca's and Wernicke's areas. However, there were observations showing that the lesions can be small and confined. (J.P.N.)

Experimental data and dose-response models

International Nuclear Information System (INIS)

Ullrich, R.L.

1985-01-01

Dose-response relationships for radiation carcinogenesis have been of interest to biologists, modelers, and statisticians for many years. Despite his interest there are few instances in which there are sufficient experimental data to allow the fitting of various dose-response models. In those experimental systems for which data are available the dose-response curves for tumor induction for the various systems cannot be described by a single model. Dose-response models which have been observed following acute exposures to gamma rays include threshold, quadratic, and linear models. Data on sex, age, and environmental influences of dose suggest a strong role of host factors on the dose response. With decreasing dose rate the effectiveness of gamma ray irradiation tends to decrease in essentially every instance. In those cases in which the high dose rate dose response could be described by a quadratic model, the effect of dose rate is consistent with predictions based on radiation effects on the induction of initial events. Whether the underlying reasons for the observed dose-rate effect is a result of effects on the induction of initial events or is due to effects on the subsequent steps in the carcinogenic process is unknown. Information on the dose response for tumor induction for high LET (linear energy transfer) radiations such as neutrons is even more limited. The observed dose and dose rate data for tumor induction following neutron exposure are complex and do not appear to be consistent with predictions based on models for the induction of initial events

Effect of dependency versus nondependency on lung lesion visualization

International Nuclear Information System (INIS)

Pechman, R.D. Jr.

1987-01-01

Paraffin blocks and mineral oil were used as a model to determine the effect of dependency versus nondependency on radiographic visualization of lung lesions in lateral thoracic radiographs. It was concluded that the increased opacity of the material surrounding the lesion, not contact between the heart and the lesion, was responsible for the inability to detect lung disease in the dependent lung. The results were tested in dogs with pneumonia in the right middle lung lobe. When the dog was in right lateral recumbency, the dependent right lung was increased in opacity and decreased in volume and the pulmonary lesion was difficult to detect. When the dog was in left lateral recumbency, the non dependent right lung was increased in volume and decreased in opacity and the pulmonary disease was clearly visible. A single recumbent lateral radiograph must not be used to assess a dog with suspected lung disease because lesions in the dependent lung lobes may not be detected

Analysis of pulmonary coin lesions

International Nuclear Information System (INIS)

Kim, O; Kim, K. H.; Oh, K. K.; Park, C. Y.

1979-01-01

For A long time the solitary pulmonary nodule has remained a difficult problem to solve and has attracted a great deal of attension in recent years. Circumscribed coin lesions of the lung were generally peripheral in location with respect to the pulmonary hilus. Because of this, important clinical problem in management and diagnosis arise. Such a lesion is discovered through roentgenologic examination. So the roentgenologists is the first be in a position to offer advise. This presentation is an attempt to correlate a useful diagnosis with roentgenologic findings of pulmonary coin lesion which enables us to get differential diagnosis of benign and malignant lesion. Histologically proven 120 cases of the pulmonary coin lesion during the period of 8 years were reviewed through plain film, tomogram, bronchoscopy, variable laboratory findings, and clinical history. The results are as follows: 1. Male to female sex ratio was 3 : 1. In age distribution, most of the malignant pulmonary coin lesion appeared in 6th decade (39%) and 5th decade (27%). In benign lesion, the most cases were in 3 rd decade. 2. Pathological cell type are as follows: Primary bronchogenic cancer 43.3%, tuberculoma 25.8%, inflammatory lesion 17.5%, benign tumor 10%, and bronchial adenoma, harmartoma, A.V. malformation, mesothelioma, are 1 case respectively. As a result benign and malignant lesion showed equal distribution (49.1% : 50.3%). 3. In symptom analysis ; cough is the most common (43.5%) symptom in malignant lesion, next follows hemoptysis (20.9%) and chest pain (14.5%). In benign lesion, most of the patient (32.7%) did not complain any symptom. 4. In malignant lesion, the most common nodular size was 4 cm (32.3%), and in benign lesion 2 cm sized coin was most common (39.3%). 5. In general, margin of nodule was very sharp and well demarcated in benign lesion (83.3%), and in malignant lesion that was less demarcated and poorly defined. 6. Most case of calcification (82.7%) was seen in benign

Hemiballism due to the lesion in the striatum demonstrated by CT scan

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Kojima, S; Ito, N; Hirayama, K [Chiba Univ. (Japan). School of Medicine; Tochigi, S

1981-09-01

Two cases of hemiballism due to vascular lesions in the striatum demonstrated by CT scan were reported. Case 1 was a 58-year-old man with hypertension and diabetes mellitus, who had cerebral hemorrhage in the right striatum. Hemiballistic movements, which were confined to his face, neck and trunk as well as limbs of the left side, appeared soon after CVA and improved on treatment with haloperidol up to 4 mg per day. Case 2 was a 63-year-old woman with hypertension, who had probable cerebral infarct in the right striatum. The hemiballistic movements, confined to her right side, appeared soon after CVA and improved on treatment with chlorpromazine up to 50 mg per day, and perphenazine up to 6 mg per day. Whereas case 1 had contralateral hemiballism, case 2 had homolateral hemiballism, both due to vascular lesions in the striatum. Although it has been generally accepted, from postmortem and experimental studies, that the lesion responsible for hemiballism was localized in the contralateral subthalamic nucleus, a few cases of hemiballism have been reported, in which the subthalamic nucleus (Luys' body) and its connections appeared to be intact at necropsy. The present cases of hemiballism with involvement of the striatum without involvement of the subthalamic nucleus by CT scan, seem to be the first reported cases. It is not clear in the CT scan whether the subthalamic nucleus is also involved in addition to the striatal lesion, however, it is unlikely due to different vascular supplies to these areas. From a clinical and an experimental point of view, we would like to propose that hemiballism can occur due to the lesion in the striatum, especially the caudate nucleus even when the subthalamic nucleus and its connections are intact.

THE SIGNIFICANCE OF LESIONS IN PERIPHERAL GANGLIA IN CHIMPANZEE AND IN HUMAN POLIOMYELITIS

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Bodian, David; Howe, Howard A.

1947-01-01

1. The peripheral ganglia of eighteen inoculated chimpanzees and thirteen uninoculated controls, and of eighteen fatal human poliomyelitis cases, were studied for histopathological evidence of the route of transmission of virus from the alimentary tract to the CNS. 2. Lesions thought to be characteristic of poliomyelitis in inoculated chimpanzees could not be sharply differentiated from lesions of unknown origin in uninoculated control animals. Moreover, although the inoculated animals as a group, in comparison with the control animals, had a greater number of infiltrative lesions in sympathetic as well as in sensory ganglia, it was not possible to make satisfactory correlations between the distribution of these lesions and the routes of inoculation. 3. In sharp contrast with chimpanzees, the celiac and stellate ganglia of the human poliomyelitis cases were free of any but insignificant infiltrative lesions. Lesions in human trigeminal and spinal sensory ganglia included neuronal damage as well as focal and perivascular inflitrative lesions, as is well known. In most ganglia, as in monkey and chimpanzee sensory ganglia, these were correlated in intensify with the degree of severity of lesions in the region of the CNS receiving their axons. This suggested that lesions in sensory ganglia probably resulted from spread of virus centrifugally from the CNS, in accord with considerable experimental evidence. 4. Two principal difficulties in the interpretation of histopathological findings in peripheral ganglia were revealed by this study. The first is that the specificity of lesions in sympathetic ganglia has not been established beyond doubt as being due to poliomyelitis. The second is that the presence of characteristic lesions in sensory ganglia does not, and cannot, reveal whether the virus reached the ganglia from the periphery or from the central nervous system, except in very early preparalytic stages or in exceptional cases of early arrest of virus spread and of

Multidimensional study of orofacial chronic neuropathic pain: An experimental study in rats.

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Claudia Daniela Montes-Angeles

2017-10-01

Full Text Available Orofacial neuropathic chronic pain (NCP is frequently attributed to lesions caused by orofacial surgeries and dental treatments. There are many experimental models available to study orofacial NCP, however, many are extremely painful for the animal due to the amplitude of the innervated region. A previously proposed mental nerve constriction model, mNC, was used in this project. Forty Wistar rats were randomly divided into two groups: one group included rats with mNC (n=20, and another rats with sham lesions (n=20. Through the use of the fixed ratio program and the progressive program, a decrease of motivation for a sweet substance, caused by the lesion, was evaluated. The possibility of alterations in cognitive learning and adaptation abilities was also assessed using the go/no-go behavioral task. The mNC group showed low induced and spontaneously evoked pain responses, as well as a decrease in the motivation for sucrose, a sign of anhedonia. This decrease does not depend on taste processing. Finally, although no alterations in the learning-memory process were observed, the mNC group did show alterations when adapting to a new rule.

Robust Bayesian Experimental Design for Conceptual Model Discrimination

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Pham, H. V.; Tsai, F. T. C.

2015-12-01

A robust Bayesian optimal experimental design under uncertainty is presented to provide firm information for model discrimination, given the least number of pumping wells and observation wells. Firm information is the maximum information of a system can be guaranteed from an experimental design. The design is based on the Box-Hill expected entropy decrease (EED) before and after the experiment design and the Bayesian model averaging (BMA) framework. A max-min programming is introduced to choose the robust design that maximizes the minimal Box-Hill EED subject to that the highest expected posterior model probability satisfies a desired probability threshold. The EED is calculated by the Gauss-Hermite quadrature. The BMA method is used to predict future observations and to quantify future observation uncertainty arising from conceptual and parametric uncertainties in calculating EED. Monte Carlo approach is adopted to quantify the uncertainty in the posterior model probabilities. The optimal experimental design is tested by a synthetic 5-layer anisotropic confined aquifer. Nine conceptual groundwater models are constructed due to uncertain geological architecture and boundary condition. High-performance computing is used to enumerate all possible design solutions in order to identify the most plausible groundwater model. Results highlight the impacts of scedasticity in future observation data as well as uncertainty sources on potential pumping and observation locations.

Experimental study of virtual colonoscopy of simulated mass lesions in pig colon: comparison of CT and MR techniques

International Nuclear Information System (INIS)

Yang Xiujun; He Zhiyan; Tao Yonghao; Miao Jingtao; Chen Yuanjiong; Hu Yuansheng; Wang Linchuan

2000-01-01

Objective: To probe into the technique and diagnostic value of MR virtual colonoscopy (MRVC) compared with CT virtual colonoscopy (CTVC) and colonoscopy. Methods: Two approximately 25-cm-long-sections of fresh pit colon in vitro had 20 mass lesions created ranging from 3 mm to 12 mm in diameter. MR scanning, as well as CT scanning of the water- or air-insufflated colon was performed, and CT data were obtained with collimation of 3 mm at a pitch of 1.0 and reconstruction intervals of 1.5 mm. MRI data were acquired with the same matrix and reformatting slab, and with heavily T 2 -weighted fast spin-echo pulse sequences. Post processed image sets were performed by the same experienced doctor on a workstation using navigator software based on CT or MRI source imaging data. One section was also underwent electron colonoscopy. Results: MRVC and CTVC displayed colon morphology in a manner similar to colonoscopy. The sensitivity of MRVC and CTVC were all 100%, and the accuracy was 71.4% for MRVC and 100% for CTVC. With the combined analysis of the four-in-one multi-view images, they accurately demonstrated the site and size of lesions and distinguished the lesions from the artifacts such as small air bubbles, and the accuracy of MRVC was improved up to 100%. CTVC was better than MRVC (P<0.05), but both were inferior to colonoscopy in depicting mucosal details of the colon and lesions (P < 0.025). Conclusion: Virtual colonoscopy (CTVC or MRVC, the former appears better) provided noninvasive endoscope-like display of the colon, and permitted identification of colonic mass lesions as small as 3 mm in diameter, the diagnostic accuracy could be improved by combining with source images and other reformations

Dotted collar placed around carotid artery induces asymmetric neointimal lesion formation in rabbits without intravascular manipulations

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Kivelä Antti

2012-10-01

Full Text Available Abstract Background Neointimal formation in atherosclerosis has been subject for intense research. However, good animal models mimicking asymmetrical lesion formation in human subjects have been difficult to establish. The aim of this study was to develop a model which would lead to the formation of eccentric lesions under macroscopically intact non-denuded endothelium. Methods We have developed a new collar model where we placed two cushions or dots inside the collar. Arterial lesions were characterized using histology and ultrasound methods. Results When this dotted collar was placed around carotid and femoral arteries it produced asymmetrical pressure on adventitia and a mild flow disturbance, and hence a change in shear stress. Our hypothesis was that this simple procedure would reproducibly produce asymmetrical lesions without any intraluminal manipulations. Intima/media ratio increased towards the distal end of the collar with the direction of blood flow under macroscopically intact endothelium. Macrophages preferentially accumulated in areas of the thickest neointima thus resembling early steps in human atherosclerotic plaque formation. Proliferating cells in these lesions and underlying media were scarce at eight weeks time point. Conclusion The improved dotted collar model produces asymmetrical human-like atherosclerotic lesions in rabbits. This model should be useful in studies regarding the pathogenesis and formation of eccentric atherosclerotic lesions.

IVIM: modeling, experimental validation and application to animal models

International Nuclear Information System (INIS)

Fournet, Gabrielle

2016-01-01

This PhD thesis is centered on the study of the IVIM ('Intravoxel Incoherent Motion') MRI sequence. This sequence allows for the study of the blood microvasculature such as the capillaries, arterioles and venules. To be sensitive only to moving groups of spins, diffusion gradients are added before and after the 180 degrees pulse of a spin echo (SE) sequence. The signal component corresponding to spins diffusing in the tissue can be separated from the one related to spins travelling in the blood vessels which is called the IVIM signal. These two components are weighted by f IVIM which represents the volume fraction of blood inside the tissue. The IVIM signal is usually modelled by a mono-exponential (ME) function and characterized by a pseudo-diffusion coefficient, D*. We propose instead a bi-exponential IVIM model consisting of a slow pool, characterized by F slow and D* slow corresponding to the capillaries as in the ME model, and a fast pool, characterized by F fast and D* fast, related to larger vessels such as medium-size arterioles and venules. This model was validated experimentally and more information was retrieved by comparing the experimental signals to a dictionary of simulated IVIM signals. The influence of the pulse sequence, the repetition time and the diffusion encoding time was also studied. Finally, the IVIM sequence was applied to the study of an animal model of Alzheimer's disease. (author) [fr

Comparative study of lesions created by high-intensity focused ultrasound using sequential discrete and continuous scanning strategies.

Science.gov (United States)

Fan, Tingbo; Liu, Zhenbo; Zhang, Dong; Tang, Mengxing

2013-03-01

Lesion formation and temperature distribution induced by high-intensity focused ultrasound (HIFU) were investigated both numerically and experimentally via two energy-delivering strategies, i.e., sequential discrete and continuous scanning modes. Simulations were presented based on the combination of Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation and bioheat equation. Measurements were performed on tissue-mimicking phantoms sonicated by a 1.12-MHz single-element focused transducer working at an acoustic power of 75 W. Both the simulated and experimental results show that, in the sequential discrete mode, obvious saw-tooth-like contours could be observed for the peak temperature distribution and the lesion boundaries, with the increasing interval space between two adjacent exposure points. In the continuous scanning mode, more uniform peak temperature distributions and lesion boundaries would be produced, and the peak temperature values would decrease significantly with the increasing scanning speed. In addition, compared to the sequential discrete mode, the continuous scanning mode could achieve higher treatment efficiency (lesion area generated per second) with a lower peak temperature. The present studies suggest that the peak temperature and tissue lesion resulting from the HIFU exposure could be controlled by adjusting the transducer scanning speed, which is important for improving the HIFU treatment efficiency.

Uterine Vascular Lesions

Science.gov (United States)

Vijayakumar, Abhishek; Srinivas, Amruthashree; Chandrashekar, Babitha Moogali; Vijayakumar, Avinash

2013-01-01

Vascular lesions of the uterus are rare; most reported in the literature are arteriovenous malformations (AVMs). Uterine AVMs can be congenital or acquired. In recent years, there has been an increasing number of reports of acquired vascular lesions of the uterus following pregnancy, abortion, cesarean delivery, and curettage. It can be seen from these reports that there is confusion concerning the terminology of uterine vascular lesions. There is also a lack of diagnostic criteria and management guidelines, which has led to an increased number of unnecessary invasive procedures (eg, angiography, uterine artery embolization, hysterectomy for abnormal vaginal bleeding). This article familiarizes readers with various vascular lesions of the uterus and their management. PMID:24340126

New Perspectives on the Brain Lesion Approach - Implications for Theoretical Models of Human Memory.

NARCIS (Netherlands)

Irish, Muireann; van Kesteren, M.T.R.

2017-01-01

Human lesion studies represent the cornerstone of modern day neuropsychology and provide an important adjunct to functional neuroimaging methods. The study of human lesion groups with damage to distinct regions of the brain permits the identification of underlying mechanisms and structures not only

Experimental model to induce obesity in rats Modelo experimental para induzir obesidade em ratos

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Vinicius Von Diemen

2006-12-01

Full Text Available The etiology of obesity is multifactorial and is becoming a problem of public health, due to its increased prevalence and the consequent repercussion of its comorbidities on the health of the population. The great similarity and homology between the genomes of rodents and humans make these animal models a major tool to study conditions affecting humans, which can be simulated in rats. Obesity can be induced in animals by neuroendocrine, dietary or genetic changes. The most widely used models to induce obesity in rats are a lesion of the ventromedial hypothalamic nucleus (VMH by administering monosodium glutamate or a direct electrical lesion, ovariectomy, feeding on hypercaloric diets and genetic manipulation for obesity.A obesidade tem etiologia multifatorial e está se tornando um problema de saúde pública devido ao aumento da sua prevalência e a conseqüente repercusão das suas comorbidades na saúde da população. A grande similaridade e homologia entre os genomas dos roedores e dos humanos tornam esses modelos animais uma importante ferramenta para o estudo de condições que afetam os humanos e que podem ser simuladas em ratos. A obesidade pode ser induzida em animais com alterações neuroendócrinas, dietéticas ou genéticas. Os modelos mais utilizados para indução de obesidade em ratos são lesão do núcleo hipotalâmico venteromedial (VMH através da administração de glutamato monossódico ou lesão elétrica direta, ooforectomia, alimentação com dietas hipercalóricas e manipulação genética para obesidade.

Multiphysics modelling and experimental validation of high concentration photovoltaic modules

International Nuclear Information System (INIS)

Theristis, Marios; Fernández, Eduardo F.; Sumner, Mike; O'Donovan, Tadhg S.

2017-01-01

Highlights: • A multiphysics modelling approach for concentrating photovoltaics was developed. • An experimental campaign was conducted to validate the models. • The experimental results were in good agreement with the models. • The multiphysics modelling allows the concentrator’s optimisation. - Abstract: High concentration photovoltaics, equipped with high efficiency multijunction solar cells, have great potential in achieving cost-effective and clean electricity generation at utility scale. Such systems are more complex compared to conventional photovoltaics because of the multiphysics effect that is present. Modelling the power output of such systems is therefore crucial for their further market penetration. Following this line, a multiphysics modelling procedure for high concentration photovoltaics is presented in this work. It combines an open source spectral model, a single diode electrical model and a three-dimensional finite element thermal model. In order to validate the models and the multiphysics modelling procedure against actual data, an outdoor experimental campaign was conducted in Albuquerque, New Mexico using a high concentration photovoltaic monomodule that is thoroughly described in terms of its geometry and materials. The experimental results were in good agreement (within 2.7%) with the predicted maximum power point. This multiphysics approach is relatively more complex when compared to empirical models, but besides the overall performance prediction it can also provide better understanding of the physics involved in the conversion of solar irradiance into electricity. It can therefore be used for the design and optimisation of high concentration photovoltaic modules.

Effect of xylitol varnishes on remineralization of artificial enamel caries lesions in situ.

Science.gov (United States)

Cardoso, C A B; Cassiano, L P S; Costa, E N; Souza-E-Silva, C M; Magalhães, A C; Grizzo, L T; Caldana, M L; Bastos, J R M; Buzalaf, M A R

2016-07-01

Analyze the effect of varnishes containing xylitol compared to commercial fluoridated varnishes on the remineralization of artificial enamel caries lesions in situ. Twenty subjects took part in this crossover, double-blind study performed in four phases of 5days each. Each subject worn palatal appliances containing four predemineralized bovine enamel specimens. Artificial caries lesions were produced by immersion in 30ml of lactic acid buffer containing 3mM CaCl2·2H2O, 3mM KH2PO4, 6μM tetraetil metil diphosphanate (pH 5.0) for 6days. The specimens in each subject were treated once with the following varnishes: 20% xylitol (experimental); Duofluorid™ (6% NaF, 6% CaF2), Duraphat™ (5% NaF, positive control) and placebo (no-F/xylitol, negative control). The varnishes were applied in a thin layer and removed after 6h. Fifteen subjects were able to finish all phases. The enamel alterations were quantified by surface hardness and transversal microradiography. The percentage of surface hardness recovery (%SHR), the integrated mineral loss and lesion depth were statistically analyzed by Friedmann and Dunn's tests test (pxylitol formulations. Significant subsurface mineral remineralization could also be seen for the experimental and commercial varnishes, except for Duraphat™, when the parameter "lesion depth" was considered. 20% xylitol varnish seem to be a promising alternative to increase surface and subsurface remineralization of artificial caries lesions in situ. effective vehicles are desirable for caries control. Xylitol varnishes seem to be promising alternatives to increase enamel remineralization in situ, which should be confirmed by clinical studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

PREVAIL: Predicting Recovery through Estimation and Visualization of Active and Incident Lesions.

Science.gov (United States)

Dworkin, Jordan D; Sweeney, Elizabeth M; Schindler, Matthew K; Chahin, Salim; Reich, Daniel S; Shinohara, Russell T

2016-01-01

The goal of this study was to develop a model that integrates imaging and clinical information observed at lesion incidence for predicting the recovery of white matter lesions in multiple sclerosis (MS) patients. Demographic, clinical, and magnetic resonance imaging (MRI) data were obtained from 60 subjects with MS as part of a natural history study at the National Institute of Neurological Disorders and Stroke. A total of 401 lesions met the inclusion criteria and were used in the study. Imaging features were extracted from the intensity-normalized T1-weighted (T1w) and T2-weighted sequences as well as magnetization transfer ratio (MTR) sequence acquired at lesion incidence. T1w and MTR signatures were also extracted from images acquired one-year post-incidence. Imaging features were integrated with clinical and demographic data observed at lesion incidence to create statistical prediction models for long-term damage within the lesion. The performance of the T1w and MTR predictions was assessed in two ways: first, the predictive accuracy was measured quantitatively using leave-one-lesion-out cross-validated (CV) mean-squared predictive error. Then, to assess the prediction performance from the perspective of expert clinicians, three board-certified MS clinicians were asked to individually score how similar the CV model-predicted one-year appearance was to the true one-year appearance for a random sample of 100 lesions. The cross-validated root-mean-square predictive error was 0.95 for normalized T1w and 0.064 for MTR, compared to the estimated measurement errors of 0.48 and 0.078 respectively. The three expert raters agreed that T1w and MTR predictions closely resembled the true one-year follow-up appearance of the lesions in both degree and pattern of recovery within lesions. This study demonstrates that by using only information from a single visit at incidence, we can predict how a new lesion will recover using relatively simple statistical techniques. The

Ischemic lesion volume determination on diffusion weighted images vs. apparent diffusion coefficient maps.

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Bråtane, Bernt Tore; Bastan, Birgul; Fisher, Marc; Bouley, James; Henninger, Nils

2009-07-07

Though diffusion weighted imaging (DWI) is frequently used for identifying the ischemic lesion in focal cerebral ischemia, the understanding of spatiotemporal evolution patterns observed with different analysis methods remains imprecise. DWI and calculated apparent diffusion coefficient (ADC) maps were serially obtained in rat stroke models (MCAO): permanent, 90 min, and 180 min temporary MCAO. Lesion volumes were analyzed in a blinded and randomized manner by 2 investigators using (i) a previously validated ADC threshold, (ii) visual determination of hypointense regions on ADC maps, and (iii) visual determination of hyperintense regions on DWI. Lesion volumes were correlated with 24 hour 2,3,5-triphenyltetrazoliumchloride (TTC)-derived infarct volumes. TTC-derived infarct volumes were not significantly different from the ADC and DWI-derived lesion volumes at the last imaging time points except for significantly smaller DWI lesions in the pMCAO model (p=0.02). Volumetric calculation based on TTC-derived infarct also correlated significantly stronger to volumetric calculation based on last imaging time point derived lesions on ADC maps than DWI (pdetermined lesion volumes on ADC maps and DWI by both investigators correlated significantly with threshold-derived lesion volumes on ADC maps with the former method demonstrating a stronger correlation. There was also a better interrater agreement for ADC map analysis than for DWI analysis. Ischemic lesion determination by ADC was more accurate in final infarct prediction, rater independent, and provided exclusive information on ischemic lesion reversibility.

Type 1 diabetes promotes disruption of advanced atherosclerotic lesions in LDL receptor-deficient mice

OpenAIRE

Johansson, Fredrik; Kramer, Farah; Barnhart, Shelley; Kanter, Jenny E.; Vaisar, Tomas; Merrill, Rachel D.; Geng, Linda; Oka, Kazuhiro; Chan, Lawrence; Chait, Alan; Heinecke, Jay W.; Bornfeldt, Karin E.

2008-01-01

Cardiovascular disease, largely because of disruption of atherosclerotic lesions, accounts for the majority of deaths in people with type 1 diabetes. Recent mouse models have provided insights into the accelerated atherosclerotic lesion initiation in diabetes, but it is unknown whether diabetes directly worsens more clinically relevant advanced lesions. We therefore used an LDL receptor-deficient mouse model, in which type 1 diabetes can be induced at will, to investigate the effects of diabe...

Dextran sodium sulfate (DSS induces necrotizing enterocolitis-like lesions in neonatal mice.

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Marco Ginzel

Full Text Available Necrotizing enterocolitis (NEC is an inflammatory bowel disease of preterm human newborns with yet unresolved etiology. An established neonatal murine model for NEC employs oral administration of lipopolysaccharides (LPS combined with hypoxia/hypothermia. In adult mice, feeding dextran sodium sulfate (DSS represents a well-established model for experimental inflammatory bowel disease. Here we investigated the effect of DSS administration on the neonatal murine intestine in comparison with the established NEC model.3-day-old C57BL/6J mice were either fed formula containing DSS or LPS. LPS treated animals were additionally stressed by hypoxia/hypothermia twice daily. After 72 h, mice were euthanized, their intestinal tissue harvested and analyzed by histology, qRT-PCR and flow cytometry. For comparison, adult C57BL/6J mice were fed with DSS for 8 days and examined likewise. Untreated, age matched animals served as controls.Adult mice treated with DSS exhibited colonic inflammation with significantly increased Cxcl2 mRNA expression. In contrast, tissue inflammation in neonatal mice treated with DSS or LPS plus hypoxia/hypothermia was present in colon and small intestine as well. Comparative analysis of neonatal mice revealed a significantly increased lesion size and intestinal Cxcl2 mRNA expression after DSS exposure. Whereas LPS administration mainly induced local neutrophil recruitment, DSS treated animals displayed increased monocytes/macrophages infiltration.Our study demonstrates the potential of DSS to induce NEC-like lesions accompanied by a significant humoral and cellular immune response in the small and large intestine of neonatal mice. The new model therefore represents a good alternative to LPS plus hypoxia/hypothermia administration requiring no additional physical stress.

[Psychotherapy of patients with brain lesions: an integrative model based on neuropsychological and psychodynamic perspectives].

Science.gov (United States)

Ouss-Ryngaert, Lisa

2010-12-01

Our model of psychotherapy for patients with brain lesions is based on an integrative approach of psychobehavioral symptoms, especially from the neuropsychological and psychodynamic perspectives. Adjustment of technical modalities and aims of psychoanalytical therapy is required for these patients. The analysis of the influence of cognitive disorders on transference and contre-transference plays a major role, including the role of procedural processes in changes in the intersubjective relationship between the patient and the therapist. Two vignettes are presented to illustrate our model, which respects the integrity of the cognitive and psychodynamic approaches and can be implemented by only one therapist, using alternatively each lecture, or by a working team bringing to light the different aspects of the same symptom.

Antipsychotic potential of quinazoline ErbB1 inhibitors in a schizophrenia model established with neonatal hippocampal lesioning.

Science.gov (United States)

Mizuno, Makoto; Iwakura, Yuriko; Shibuya, Masako; Zheng, Yingjun; Eda, Takeyoshi; Kato, Taisuke; Takasu, Yohei; Nawa, Hiroyuki

2010-01-01

Hyper-signaling of the epidermal growth factor receptor family (ErbB) is implicated in the pathophysiology of schizophrenia. Various quinazoline inhibitors targeting ErbB1 or ErbB2 - 4 have been developed as anti-cancer agents and might be useful for antipsychotic treatment. In the present study, we used an animal model of schizophrenia established by neonatal hippocampal lesioning and evaluated the neurobehavioral consequences of ErbB1-inhibitor treatment. Subchronic administration of the ErbB1 inhibitor ZD1839 to the cerebroventricle of rats receiving neonatal hippocampal lesioning ameliorated deficits in prepulse inhibition as well as those in the latent inhibition of tone-dependent fear learning. There were no apparent adverse effects on basal learning scores or locomotor activity, however. The administration of other ErbB1 inhibitors, PD153035 and OSI-774, similarly attenuated the prepulse inhibition impairment of this animal model. In parallel, there were decreases in ErbB1 phosphorylation in animals treated with ErbB1 inhibitors. These results indicate an antipsychotic potential of quinazoline ErbB1 inhibitors. ErbB receptor tyrosine kinases may be novel therapeutic targets for schizophrenia or its related psychotic symptoms.

[RESEARCH PROGRESS OF EXPERIMENTAL ANIMAL MODELS OF AVASCULAR NECROSIS OF FEMORAL HEAD].

Science.gov (United States)

Yu, Kaifu; Tan, Hongbo; Xu, Yongqing

2015-12-01

To summarize the current researches and progress on experimental animal models of avascular necrosis of the femoral head. Domestic and internation literature concerning experimental animal models of avascular necrosis of the femoral head was reviewed and analyzed. The methods to prepare the experimental animal models of avascular necrosis of the femoral head can be mainly concluded as traumatic methods (including surgical, physical, and chemical insult), and non-traumatic methods (including steroid, lipopolysaccharide, steroid combined with lipopolysaccharide, steroid combined with horse serum, etc). Each method has both merits and demerits, yet no ideal methods have been developed. There are many methods to prepare the experimental animal models of avascular necrosis of the femoral head, but proper model should be selected based on the aim of research. The establishment of ideal experimental animal models needs further research in future.

Local increase of arginase activity in lesions of patients with cutaneous leishmaniasis in Ethiopia.

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Tamrat Abebe

Full Text Available Cutaneous leishmaniasis is a vector-borne disease that is in Ethiopia mainly caused by the parasite Leishmania aethiopica. This neglected tropical disease is common in rural areas and causes serious morbidity. Persistent nonhealing cutaneous leishmaniasis has been associated with poor T cell mediated responses; however, the underlying mechanisms are not well understood.We have recently shown in an experimental model of cutaneous leishmaniasis that arginase-induced L-arginine metabolism suppresses antigen-specific T cell responses at the site of pathology, but not in the periphery. To test whether these results translate to human disease, we recruited patients presenting with localized lesions of cutaneous leishmaniasis and assessed the levels of arginase activity in cells isolated from peripheral blood and from skin biopsies. Arginase activity was similar in peripheral blood mononuclear cells (PBMCs from patients and healthy controls. In sharp contrast, arginase activity was significantly increased in lesion biopsies of patients with localized cutaneous leishmaniasis as compared with controls. Furthermore, we found that the expression levels of CD3ζ, CD4 and CD8 molecules were considerably lower at the site of pathology as compared to those observed in paired PBMCs.Our results suggest that increased arginase in lesions of patients with cutaneous leishmaniasis might play a role in the pathogenesis of the disease by impairing T cell effector functions.

Basolateral amygdala lesions abolish mutual reward preferences in rats.

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Hernandez-Lallement, Julen; van Wingerden, Marijn; Schäble, Sandra; Kalenscher, Tobias

2016-01-01

In a recent study, we demonstrated that rats prefer mutual rewards in a Prosocial Choice Task. Here, employing the same task, we show that the integrity of basolateral amygdala was necessary for the expression of mutual reward preferences. Actor rats received bilateral excitotoxic (n=12) or sham lesions (n=10) targeting the basolateral amygdala and were subsequently tested in a Prosocial Choice Task where they could decide between rewarding ("Both Reward") or not rewarding a partner rat ("Own Reward"), either choice yielding identical reward to the actors themselves. To manipulate the social context and control for secondary reinforcement sources, actor rats were paired with either a partner rat (partner condition) or with an inanimate rat toy (toy condition). Sham-operated animals revealed a significant preference for the Both-Reward-option in the partner condition, but not in the toy condition. Amygdala-lesioned animals exhibited significantly lower Both-Reward preferences than the sham group in the partner but not in the toy condition, suggesting that basolateral amygdala was required for the expression of mutual reward preferences. Critically, in a reward magnitude discrimination task in the same experimental setup, both sham-operated and amygdala-lesioned animals preferred large over small rewards, suggesting that amygdala lesion effects were restricted to decision making in social contexts, leaving self-oriented behavior unaffected. Copyright © 2015 Elsevier Inc. All rights reserved.

Experimental In Vivo Models of Candidiasis

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Esther Segal

2018-02-01

Full Text Available Candidiasis is a multifaceted fungal disease including mucosal-cutaneous, visceral, and disseminated infections caused by yeast species of the genus Candida. Candida infections are among the most common human mycoses. Candida species are the third to fourth most common isolates from bloodstream infections in neutropenic or immunocompromised hospitalized patients. The mucosal-cutaneous forms—particularly vaginal infections—have a high prevalence. Vaginitis caused by Candida species is the second most common vaginal infection. Hence, candidiasis is a major subject for research, including experimental in vivo models to study pathogenesis, prevention, or therapy of the disease. The following review article will focus on various experimental in vivo models in different laboratory animals, such as mammals (mice, rats, rabbits, the fruit fly–Drosophila melanogaster, the larvae of the moth Galleria mellonella, or the free-living nematode Caenorhabditis elegans. The review will describe the induction of the different clinical forms of candidiasis in the various models and the validity of such models in mimicking the human clinical situations. The use of such models for the assessment of antifungal drugs, evaluation of potential vaccines to protect before candidiasis, exploration of Candida virulence factors, and comparison of pathogenicity of different Candida species will be included in the review. All of the above will be reported as based on published studies of numerous investigators as well as on the research of the author and his group.

Experimental comparison of models for ultrafast impact ionization is silicon

DEFF Research Database (Denmark)

Tarekegne, Abebe Tilahun; Iwaszczuk, Krzysztof; Jepsen, Peter Uhd

2016-01-01

We compare experimentally the exponential and quadratic (Keldysh formula) impact ionization models using THz induced impact ionization in silicon. We demonstrate that the exponential model offers the best description of impact ionization process for ultrashort electric filed pulses.......We compare experimentally the exponential and quadratic (Keldysh formula) impact ionization models using THz induced impact ionization in silicon. We demonstrate that the exponential model offers the best description of impact ionization process for ultrashort electric filed pulses....

Subtle Cardiovascular Dysfunction in the Unilateral 6-Hydroxydopamine-Lesioned Rat

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K. Slack

2010-01-01

Full Text Available The present study evaluated whether the unilateral 6-hydroxydopamine (6-OHDA model of Parkinson's disease produces autonomic deficits. Autonomic parameters were assessed by implanting a small radiofrequency telemetry device which measured heart rate variability (HRV, diurnal rhythms of heart rate (HR, core body temperature (cBT and locomotor activity (LA. Rats then received 6-OHDA lesion or sham surgery. 6-OHDA lesioned rats exhibited head and body axis biases, defective sensorimotor function (“disengage” test, and prominent apomorphine rotation (all P<.05 versus controls. Diurnal rhythm of HR was lower for 6-OHDA lesioned rats (n=8 versus controls (n=6; P<.05. Whilst HR decreased similarly in both groups during the day, there was a greater decrease in HR for the 6-OHDA lesioned rats at night (by 38 b.p.m. relative to 17 b.p.m. for controls. LA and cBT did not differ between surgery groups. This study indicates the unilateral 6-OHDA model of PD shows subtle signs of cardiovascular autonomic dysfunction.

Evaluación del módulo de elasticidad de materiales estéticos para la restauración de lesiones cervicales Assessment of the elasticity module of aesthetic materials for restoration of cervical lesions

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Claudia Estela Bonnin

2012-06-01

Full Text Available La pérdida de tejido en la zona cervical ha sido atribuida principalmente a la erosión y abrasión producidas por el cepillo de dientes. El rol de las fuerzas oclusales es un factor muy importante a tener en cuenta en el desarrollo y avance de estas lesiones cervicales no cariosas. Distinguir las diferentes propiedades mecánicas y sobre todo el módulo de elasticidad de los materiales estéticos utilizados para la restauración de este tipo de lesiones, permitirá una sobrevida mayor de las obturaciones y una gran mejoría en el tratamiento de nuestros pacientes. El objetivo de este trabajo fue evaluar el módulo de elasticidad de 6 materiales restauradores estéticos. Siguiendo la norma ISO 4049 se confeccionaron 10 probetas de cada material experimental. Se empleó el ensayo de flexión de 3 puntos con una INSTRON 4486. De la relación numérica entre los valores de tensión (T y deformación (D, se obtuvo el módulo de elasticidad o de Young (E, para cada material experimental. El análisis de varianza mostró diferencias significativas (p Te loss of tissue in the cervical zone has been attributed to the erosion and abrasion provoked by toothbrush. The role of occlusal forces is a very important factor to be taken into account in the development and advance of these carious non-cervical lesions. To distinguish the different mechanical properties and mainly the elasticity module of aesthetic material used for repair of this type of lesion, will allows a great survival of the obturations and in large extent in the treatment of our patients. The aim of present paper was to assess the elasticity module of 6 esthetic restoring materials. Following the ISO 4049 rule 10 test tubes of ach experimental material. A flexion assay of 3 points with INSTRON 4486 was used. From the numerical relation among the tension values (T and deformation (D we obtained the elasticity or Young (E elasticity module for each experimental material. The variance

Texture alteration detection in bitemporal images of lesions with psoriasis

DEFF Research Database (Denmark)

Maletti, Gabriela Mariel; Ersbøll, Bjarne Kjær

2003-01-01

The objective of this work is to explore the feasibility of quantifying textural change between pairs of segmented patterns without registering them. The Multi-variate Alteration Detection (M.A.D.) Transform is applied to a texture model constructed with the data of segmented psoriasis lesions im...... images. The texture model is Haralick's co-occurrence matrix, which is computed and normalized for each single band with the equalized data of a given lesion. The contribution of each single color band to the textural change is analyzed....

Modelling and experimental studies on the transfer of radionuclides to fruit

International Nuclear Information System (INIS)

Carini, F.; Atkinson, C.J.; Collins, C.; Coughtrey, P.J.; Eged, K.; Fulker, M.; Green, N.; Kinnersley, R.; Linkov, I.; Mitchell, N.G.; Mourlon, C.; Ould-Dada, Z.; Quinault, J.M.; Robles, B.; Stewart, A.; Sweeck, L.; Venter, A.

2005-01-01

Although fruit is an important component of the diet, the extent to which it contributes to radiological exposure remains unclear, partially as a consequence of uncertainties in models and data used to assess transfer of radionuclides in the food chain. A Fruits Working Group operated as part of the IAEA BIOMASS (BIOsphere Modelling and ASSessment) programme from 1997 to 2000, with the aim of improving the robustness of the models that are used for radiological assessment. The Group completed a number of modelling and experimental activities including: (i) a review of experimental, field and modelling information on the transfer of radionuclides to fruit; (ii) discussion of recently completed or ongoing experimental studies; (iii) development of a database on the transfer of radionuclides to fruit; (iv) development of a conceptual model for fruit and (v) two model intercomparison studies and a model validation study. The Group achieved significant advances in understanding the processes involved in transfer of radionuclides to fruit. The work demonstrated that further experimental and modelling studies are required to ensure that the current generation of models can be applied to a wide range of scenarios

High-Risk Breast Lesions: A Machine Learning Model to Predict Pathologic Upgrade and Reduce Unnecessary Surgical Excision.

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Bahl, Manisha; Barzilay, Regina; Yedidia, Adam B; Locascio, Nicholas J; Yu, Lili; Lehman, Constance D

2018-03-01

Purpose To develop a machine learning model that allows high-risk breast lesions (HRLs) diagnosed with image-guided needle biopsy that require surgical excision to be distinguished from HRLs that are at low risk for upgrade to cancer at surgery and thus could be surveilled. Materials and Methods Consecutive patients with biopsy-proven HRLs who underwent surgery or at least 2 years of imaging follow-up from June 2006 to April 2015 were identified. A random forest machine learning model was developed to identify HRLs at low risk for upgrade to cancer. Traditional features such as age and HRL histologic results were used in the model, as were text features from the biopsy pathologic report. Results One thousand six HRLs were identified, with a cancer upgrade rate of 11.4% (115 of 1006). A machine learning random forest model was developed with 671 HRLs and tested with an independent set of 335 HRLs. Among the most important traditional features were age and HRL histologic results (eg, atypical ductal hyperplasia). An important text feature from the pathologic reports was "severely atypical." Instead of surgical excision of all HRLs, if those categorized with the model to be at low risk for upgrade were surveilled and the remainder were excised, then 97.4% (37 of 38) of malignancies would have been diagnosed at surgery, and 30.6% (91 of 297) of surgeries of benign lesions could have been avoided. Conclusion This study provides proof of concept that a machine learning model can be applied to predict the risk of upgrade of HRLs to cancer. Use of this model could decrease unnecessary surgery by nearly one-third and could help guide clinical decision making with regard to surveillance versus surgical excision of HRLs. © RSNA, 2017.

Models for Experimental High Density Housing

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Bradecki, Tomasz; Swoboda, Julia; Nowak, Katarzyna; Dziechciarz, Klaudia

2017-10-01

The article presents the effects of research on models of high density housing. The authors present urban projects for experimental high density housing estates. The design was based on research performed on 38 examples of similar housing in Poland that have been built after 2003. Some of the case studies show extreme density and that inspired the researchers to test individual virtual solutions that would answer the question: How far can we push the limits? The experimental housing projects show strengths and weaknesses of design driven only by such indexes as FAR (floor attenuation ratio - housing density) and DPH (dwellings per hectare). Although such projects are implemented, the authors believe that there are reasons for limits since high index values may be in contradiction to the optimum character of housing environment. Virtual models on virtual plots presented by the authors were oriented toward maximising the DPH index and DAI (dwellings area index) which is very often the main driver for developers. The authors also raise the question of sustainability of such solutions. The research was carried out in the URBAN model research group (Gliwice, Poland) that consists of academic researchers and architecture students. The models reflect architectural and urban regulations that are valid in Poland. Conclusions might be helpful for urban planners, urban designers, developers, architects and architecture students.

Experimental Validation of a Dynamic Model for Lightweight Robots

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Alessandro Gasparetto

2013-03-01

Full Text Available Nowadays, one of the main topics in robotics research is dynamic performance improvement by means of a lightening of the overall system structure. The effective motion and control of these lightweight robotic systems occurs with the use of suitable motion planning and control process. In order to do so, model-based approaches can be adopted by exploiting accurate dynamic models that take into account the inertial and elastic terms that are usually neglected in a heavy rigid link configuration. In this paper, an effective method for modelling spatial lightweight industrial robots based on an Equivalent Rigid Link System approach is considered from an experimental validation perspective. A dynamic simulator implementing the formulation is used and an experimental test-bench is set-up. Experimental tests are carried out with a benchmark L-shape mechanism.

Interactive lesion segmentation with shape priors from offline and online learning.

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Shepherd, Tony; Prince, Simon J D; Alexander, Daniel C

2012-09-01

In medical image segmentation, tumors and other lesions demand the highest levels of accuracy but still call for the highest levels of manual delineation. One factor holding back automatic segmentation is the exemption of pathological regions from shape modelling techniques that rely on high-level shape information not offered by lesions. This paper introduces two new statistical shape models (SSMs) that combine radial shape parameterization with machine learning techniques from the field of nonlinear time series analysis. We then develop two dynamic contour models (DCMs) using the new SSMs as shape priors for tumor and lesion segmentation. From training data, the SSMs learn the lower level shape information of boundary fluctuations, which we prove to be nevertheless highly discriminant. One of the new DCMs also uses online learning to refine the shape prior for the lesion of interest based on user interactions. Classification experiments reveal superior sensitivity and specificity of the new shape priors over those previously used to constrain DCMs. User trials with the new interactive algorithms show that the shape priors are directly responsible for improvements in accuracy and reductions in user demand.

Ghost cell lesions

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E Rajesh

2015-01-01

Full Text Available Ghost cells have been a controversy for a long time. Ghost cell is a swollen/enlarged epithelial cell with eosnophilic cytoplasm, but without a nucleus. In routine H and E staining these cells give a shadowy appearance. Hence these cells are also called as shadow cells or translucent cells. The appearance of these cells varies from lesion to lesion involving odontogenic and nonodontogenic lesions. This article review about the origin, nature and significance of ghost cells in different neoplasms.

Development of a fault test experimental facility model using Matlab

Energy Technology Data Exchange (ETDEWEB)

Pereira, Iraci Martinez; Moraes, Davi Almeida, E-mail: martinez@ipen.br, E-mail: dmoraes@dk8.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

The Fault Test Experimental Facility was developed to simulate a PWR nuclear power plant and is instrumented with temperature, level and pressure sensors. The Fault Test Experimental Facility can be operated to generate normal and fault data, and these failures can be added initially small, and their magnitude being increasing gradually. This work presents the Fault Test Experimental Facility model developed using the Matlab GUIDE (Graphical User Interface Development Environment) toolbox that consists of a set of functions designed to create interfaces in an easy and fast way. The system model is based on the mass and energy inventory balance equations. Physical as well as operational aspects are taken into consideration. The interface layout looks like a process flowchart and the user can set the input variables. Besides the normal operation conditions, there is the possibility to choose a faulty variable from a list. The program also allows the user to set the noise level for the input variables. Using the model, data were generated for different operational conditions, both under normal and fault conditions with different noise levels added to the input variables. Data generated by the model will be compared with Fault Test Experimental Facility data. The Fault Test Experimental Facility theoretical model results will be used for the development of a Monitoring and Fault Detection System. (author)

Development of a fault test experimental facility model using Matlab

International Nuclear Information System (INIS)

Pereira, Iraci Martinez; Moraes, Davi Almeida

2015-01-01

The Fault Test Experimental Facility was developed to simulate a PWR nuclear power plant and is instrumented with temperature, level and pressure sensors. The Fault Test Experimental Facility can be operated to generate normal and fault data, and these failures can be added initially small, and their magnitude being increasing gradually. This work presents the Fault Test Experimental Facility model developed using the Matlab GUIDE (Graphical User Interface Development Environment) toolbox that consists of a set of functions designed to create interfaces in an easy and fast way. The system model is based on the mass and energy inventory balance equations. Physical as well as operational aspects are taken into consideration. The interface layout looks like a process flowchart and the user can set the input variables. Besides the normal operation conditions, there is the possibility to choose a faulty variable from a list. The program also allows the user to set the noise level for the input variables. Using the model, data were generated for different operational conditions, both under normal and fault conditions with different noise levels added to the input variables. Data generated by the model will be compared with Fault Test Experimental Facility data. The Fault Test Experimental Facility theoretical model results will be used for the development of a Monitoring and Fault Detection System. (author)

Spinal cord injury-induced immune deficiency syndrome enhances infection susceptibility dependent on lesion level.

Science.gov (United States)

Brommer, Benedikt; Engel, Odilo; Kopp, Marcel A; Watzlawick, Ralf; Müller, Susanne; Prüss, Harald; Chen, Yuying; DeVivo, Michael J; Finkenstaedt, Felix W; Dirnagl, Ulrich; Liebscher, Thomas; Meisel, Andreas; Schwab, Jan M

2016-03-01

Pneumonia is the leading cause of death after acute spinal cord injury and is associated with poor neurological outcome. In contrast to the current understanding, attributing enhanced infection susceptibility solely to the patient's environment and motor dysfunction, we investigate whether a secondary functional neurogenic immune deficiency (spinal cord injury-induced immune deficiency syndrome, SCI-IDS) may account for the enhanced infection susceptibility. We applied a clinically relevant model of experimental induced pneumonia to investigate whether the systemic SCI-IDS is functional sufficient to cause pneumonia dependent on spinal cord injury lesion level and investigated whether findings are mirrored in a large prospective cohort study after human spinal cord injury. In a mouse model of inducible pneumonia, high thoracic lesions that interrupt sympathetic innervation to major immune organs, but not low thoracic lesions, significantly increased bacterial load in lungs. The ability to clear the bacterial load from the lung remained preserved in sham animals. Propagated immune susceptibility depended on injury of central pre-ganglionic but not peripheral postganglionic sympathetic innervation to the spleen. Thoracic spinal cord injury level was confirmed as an independent increased risk factor of pneumonia in patients after motor complete spinal cord injury (odds ratio = 1.35, P spinal cord injury directly causes increased risk for bacterial infection in mice as well as in patients. Besides obvious motor and sensory paralysis, spinal cord injury also induces a functional SCI-IDS ('immune paralysis'), sufficient to propagate clinically relevant infection in an injury level dependent manner. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Protective effects of cannabidiol on lesion-induced intervertebral disc degeneration.

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João W Silveira

Full Text Available Disc degeneration is a multifactorial process that involves hypoxia, inflammation, neoinnervation, accelerated catabolism, and reduction in water and glycosaminoglycan content. Cannabidiol is the main non-psychotropic component of the Cannabis sativa with protective and anti-inflammatory properties. However, possible therapeutic effects of cannabidiol on intervertebral disc degeneration have not been investigated yet. The present study investigated the effects of cannabidiol intradiscal injection in the coccygeal intervertebral disc degeneration induced by the needle puncture model using magnetic resonance imaging (MRI and histological analyses. Disc injury was induced in the tail of male Wistar rats via a single needle puncture. The discs selected for injury were punctured percutaneously using a 21-gauge needle. MRI and histological evaluation were employed to assess the results. The effects of intradiscal injection of cannabidiol (30, 60 or 120 nmol injected immediately after lesion were analyzed acutely (2 days by MRI. The experimental group that received cannabidiol 120 nmol was resubmitted to MRI examination and then to histological analyses 15 days after lesion/cannabidiol injection. The needle puncture produced a significant disc injury detected both by MRI and histological analyses. Cannabidiol significantly attenuated the effects of disc injury induced by the needle puncture. Considering that cannabidiol presents an extremely safe profile and is currently being used clinically, these results suggest that this compound could be useful in the treatment of intervertebral disc degeneration.

Application of Iterative Robust Model-based Optimal Experimental Design for the Calibration of Biocatalytic Models

DEFF Research Database (Denmark)

Van Daele, Timothy; Gernaey, Krist V.; Ringborg, Rolf Hoffmeyer

2017-01-01

The aim of model calibration is to estimate unique parameter values from available experimental data, here applied to a biocatalytic process. The traditional approach of first gathering data followed by performing a model calibration is inefficient, since the information gathered during...... experimentation is not actively used to optimise the experimental design. By applying an iterative robust model-based optimal experimental design, the limited amount of data collected is used to design additional informative experiments. The algorithm is used here to calibrate the initial reaction rate of an ω......-transaminase catalysed reaction in a more accurate way. The parameter confidence region estimated from the Fisher Information Matrix is compared with the likelihood confidence region, which is a more accurate, but also a computationally more expensive method. As a result, an important deviation between both approaches...

Huntington disease: Experimental models and therapeutic perspectives

International Nuclear Information System (INIS)

Serrano Sanchez, Teresa; Blanco Lezcano, Lisette; Garcia Minet, Rocio; Alberti Amador, Esteban; Diaz Armesto, Ivan and others

2011-01-01

Huntington's disease (HD) is a degenerative dysfunction of hereditary origin. Up to date there is not, an effective treatment to the disease which having lapsed 15 or 20 years advances inexorably, in a slow form, toward the total inability or death. This paper reviews the clinical and morphological characteristics of Huntington's disease as well as the experimental models more commonly used to study this disease, having as source the articles indexed in Medline data base, published in the last 20 years. Advantages and disadvantages of all experimental models to reproduce the disease as well as the perspectives to therapeutic assay have been also considered. the consent of outline reported about the toxic models, those induced by neurotoxins such as quinolinic acid, appears to be the most appropriate to reproduce the neuropathologic characteristic of the disease, an genetic models contributing with more evidence to the knowledge of the disease etiology. Numerous treatments ameliorate clinical manifestations, but none of them has been able to stop or diminish the affectations derived from neuronal loss. At present time it is possible to reproduce, at least partially, the characteristics of the disease in experimentation animals that allow therapy evaluation in HD. from the treatment view point, the more promissory seems to be transplantation of no neuronal cells, taking into account ethical issues and factibility. On the other hand the new technology of interference RNA emerges as a potential therapeutic tool for treatment in HD, and to respond basic questions on the development of the disease.

Recent mouse and rat methods for the study of experimental oral candidiasis.

Science.gov (United States)

Costa, Anna C B P; Pereira, Cristiane A; Junqueira, Juliana C; Jorge, Antonio O C

2013-07-01

The Candida genus expresses virulence factors that, when combined with immunosuppression and other risk factors, can cause different manifestations of oral candidiasis. The treatment of mucosal infections caused by Candida and the elucidation of the disease process have proven challenging. Therefore, the study of experimentally induced oral candidiasis in rats and mice is useful to clarify the etiopathology of this condition, improve diagnosis, and search for new therapeutic options because the disease process in these animals is similar to that of human candidiasis lesions. Here, we describe and discuss new studies involving rat and mouse models of oral candidiasis with respect to methods for inducing experimental infection, methods for evaluating the development of experimental candidiasis, and new treatment strategies for oral candidiasis.

Recent mouse and rat methods for the study of experimental oral candidiasis

Science.gov (United States)

Costa, Anna CBP; Pereira, Cristiane A; Junqueira, Juliana C; Jorge, Antonio OC

2013-01-01

The Candida genus expresses virulence factors that, when combined with immunosuppression and other risk factors, can cause different manifestations of oral candidiasis. The treatment of mucosal infections caused by Candida and the elucidation of the disease process have proven challenging. Therefore, the study of experimentally induced oral candidiasis in rats and mice is useful to clarify the etiopathology of this condition, improve diagnosis, and search for new therapeutic options because the disease process in these animals is similar to that of human candidiasis lesions. Here, we describe and discuss new studies involving rat and mouse models of oral candidiasis with respect to methods for inducing experimental infection, methods for evaluating the development of experimental candidiasis, and new treatment strategies for oral candidiasis. PMID:23715031

Oral White Lesions: Presentation and Comparison of Oral Submucous Fibrosis with Other Lesions

International Nuclear Information System (INIS)

Maqsood, A.; Aman, N.

2013-01-01

Objective: To compare oral submucous fibrosis with other white oral lesions for presentation and associated factors. Study Design: Cross-sectional study. Place and Duration of Study: The Departments of Oral Medicine and Oral and Maxillofacial Surgery, Dr. Ishrat-ul-Ibad Institute of Oral Health Sciences (DIKIOHS), Karachi, from May 2008 to May 2009. Methodology: Patients presenting with oral white lesions were selected by consecutive non-purposive sampling and clinico-demographic data was collected. For patients with oral submucous fibrosis (OSF), additional information like duration of habits, maximal incisal opening (MIO), presence of any other associated lesion were noted. OSF was compared with other white lesions for any association between characteristic of subjects. Chi-square and independent t-tests for determining the statistical significance at p < 0.05. Results: OSF was present in 59.6% (n = 106) of the 178 patients; other white lesions were 40.4% (n = 72). The mean age of patients with OSF was 34 +- 12.7 years and 45.81 +- 16.2 years in patients with other white lesions, (p < 0.0001). Items containing areca nut were consumed more by patients with OSF, with a significant (p < 0.0001) compared to patients with other white lesions. Conclusion: OSF was the predominant white lesion in patients examined at DIKIOHS. Areca nut was found to be chewed more by patients with OSF and still longer by patients with SCC. (author)

Experimental models of developmental hypothyroidism.

Science.gov (United States)

Argumedo, G S; Sanz, C R; Olguín, H J

2012-02-01

Hypothyroidism is a systemic disease resulting from either thyroid gland's anatomical and functional absence or lack of hypophyseal stimulation, both of which can lead to deficiency in thyroid hormone (TH) production. TH is essential for human and animal development, growth, and function of multiple organs. Children with deficient TH can develop alterations in central nervous system (CNS), striated muscle, bone tissue, liver, bone marrow, and cardiorespiratory system. Among the clinical outlook are signs like breathing difficulty, cardiac insufficiency, dysphagia, and repeated bronchial aspiration, constipation, muscle weakness, cognitive alterations, cochlear dysfunction, reduced height, defects in temperature regulation, anaemia, jaundice, susceptibility to infection, and others. Experimental and clinical studies have shown that TH is very essential for normal brain development. Other research work based on mice pointed out that a reduced level of TH in pregnant mother leads to congenital hypothyroidism in animal models and it is associated with mental retardation, deep neurologic deficiency that impacts on cognitive, learning, and memory functions. The principal experimental model studies that have focused on hypothyroidism are reviewed in this study. This is important on considering the fact that almost all animal species require thyroid hormones for their metabolism. © Georg Thieme Verlag KG Stuttgart · New York.

Optimal Experimental Design for Model Discrimination

Science.gov (United States)

Myung, Jay I.; Pitt, Mark A.

2009-01-01

Models of a psychological process can be difficult to discriminate experimentally because it is not easy to determine the values of the critical design variables (e.g., presentation schedule, stimulus structure) that will be most informative in differentiating them. Recent developments in sampling-based search methods in statistics make it…

Experimental study and modeling of a novel magnetorheological elastomer isolator

International Nuclear Information System (INIS)

Yang, Jian; Li, Weihua; Sun, Shuaishuai; Du, Haiping; Li, Yancheng; Li, Jianchun; Deng, H X

2013-01-01

This paper reports an experimental setup aiming at evaluating the performance of a newly designed magnetorheological elastomer (MRE) seismic isolator. As a further effort to explore the field-dependent stiffness/damping properties of the MRE isolator, a series of experimental testing were conducted. Based upon the analysis of the experimental responses and the characteristics of the MRE isolator, a new model that is capable of reproducing the unique MRE isolator dynamics behaviors is proposed. The validation results verify the model’s effectiveness to portray the MRE isolator. A study on the field-dependent parameters is then provided to make the model valid with fluctuating magnetic fields. To fully explore the mechanism of the proposed model, an investigation relating the dependence of the proposed model on every parameter is carried out. (technical note)

A stochastic model of hormesis

International Nuclear Information System (INIS)

Yakovlev, A.Yu.; Tsodikov, A.D.; Bass, L.

1993-01-01

In order to describe the life-prolonging effect of some agents that are harmful at higher doses, ionizing radiations in particular, a stochastic model is developed in terms of accumulation and progression of intracellular lesions caused by the environment and by the agent itself. The processes of lesion repair, operating at the molecular and cellular level, are assumed to be responsible for this hormesis effect within the framework of the proposed model. Properties of lifetime distributions, derived for analysis of animal experiments with prolonged and acute irradiation, are given special attention. The model provides efficient means of interpreting experimental findings, as evidenced by its application to analysis of some published data on the hormetic effects of prolonged irradiation and of procaine on animal longevity. 51 refs., 2 figs., 1 tabs

Imaging review of lipomatous musculoskeletal lesions

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Burt Ashley M.

2017-01-01

Full Text Available Lipomatous lesions are common musculoskeletal lesions that can arise within the soft tissues, bone, neurovascular structures, and synovium. The majority of these lesions are benign, and many of the benign lesions can be diagnosed by radiologic evaluation. However, radiologic differences between benign and malignant lipomatous lesions may be subtle and pathologic correlation is often needed. The use of sonography, computed tomography (CT, and magnetic resonance imaging (MRI is useful not only in portraying fat within the lesion, but also for evaluating the presence and extent of soft tissue components. Lipomas make up most soft tissue lipomatous lesions, but careful evaluation must be performed to distinguish these lesions from a low-grade liposarcoma. In addition to the imaging appearance, the location of the lesion and the patient demographics can be utilized to help diagnose other soft tissue lipomatous lesions, such as elastofibroma dorsi, angiolipoma, lipoblastoma, and hibernoma. Osseous lipomatous lesions such as a parosteal lipoma and intraosseous lipoma occur less commonly as their soft tissue counterpart, but are also benign. Neurovascular and synovial lipomatous lesions are much rarer lesions but demonstrate more classic radiologic findings, particularly on MRI. A review of the clinical, radiologic, and pathologic characteristics of these lesions is presented.

Hock lesions and free-stall design.

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Weary, D M; Taszkun, I

2000-04-01

We compared the prevalence and severity of skin lesions on the hocks of lactating dairy cows in southern British Columbia, comparing 20 farms using three common bedding surfaces: sawdust, sand, and geotextile mattresses. Skin lesions were scored at five positions on the hock. For each position we noted if the lesion showed inflammatory attributes, and then assigned a severity score. Of the 1752 lactating cows scored, 1267 cows (73%) had at least one hock lesion. Of those cows with lesions, 87% had lesions on both legs, 76% had lesions on more than one location on the hock, and 78% had a lesion of at least moderate severity (i.e., evidence of skin breakage or an area of hair loss >10 cm2). Lesions were most prevalent on farms that used geotextile mattresses (91% of cows) and least common on farms that used sand (24% of cows). Moreover, lesions on cows from farms using mattresses were more numerous and more severe than those on cows from sand-bedded farms. The prevalence and severity of lesions on farms using sawdust was intermediate. Lesions also varied in relation to location on the hock. For farms using geotextile mattresses, lesions were more common and more severe on the lateral surfaces of both the tuber calcis and the tarsal joint. On farms using sawdust, lesions were common on the dorsal surface of the tuber calcis and the lateral surfaces of both the tuber calcis and the tarsal joint. Lesions were rare on all five positions for cows from sand-bedded farms. Among the 10 farms sampled using sawdust, we found a significant negative relationship between the length of the stall and severity of lesions. For cows with lesions, the number and severity of lesions increased with age.

DNA Damage by Ionizing Radiation: Tandem Double Lesions by Charged Particles

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Huo, Winifred M.; Chaban, Galina M.; Wang, Dunyou; Dateo, Christopher E.

2005-01-01

Oxidative damages by ionizing radiation are the source of radiation-induced carcinogenesis, damage to the central nervous system, lowering of the immune response, as well as other radiation-induced damages to human health. Monte Carlo track simulations and kinetic modeling of radiation damages to the DNA employ available molecular and cellular data to simulate the biological effect of high and low LET radiation io the DNA. While the simulations predict single and double strand breaks and base damages, so far all complex lesions are the result of stochastic coincidence from independent processes. Tandem double lesions have not yet been taken into account. Unlike the standard double lesions that are produced by two separate attacks by charged particles or radicals, tandem double lesions are produced by one single attack. The standard double lesions dominate at the high dosage regime. On the other hand, tandem double lesions do not depend on stochastic coincidences and become important at the low dosage regime of particular interest to NASA. Tandem double lesions by hydroxyl radical attack of guanine in isolated DNA have been reported at a dosage of radiation as low as 10 Gy. The formation of two tandem base lesions was found to be linear with the applied doses, a characteristic of tandem lesions. However, tandem double lesions from attack by a charged particle have not been reported.

Effect of Enamel Caries Lesion Baseline Severity on Fluoride Dose-Response

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Frank Lippert

2017-01-01

Full Text Available This study aimed to investigate the effect of enamel caries lesion baseline severity on fluoride dose-response under pH cycling conditions. Early caries lesions were created in human enamel specimens at four different severities (8, 16, 24, and 36 h. Lesions were allocated to treatment groups (0, 83, and 367 ppm fluoride as sodium fluoride based on Vickers surface microhardness (VHN and pH cycled for 5 d. The cycling model comprised 3 × 1 min fluoride treatments sandwiched between 2 × 60 min demineralization challenges with specimens stored in artificial saliva in between. VHN was measured again and changes versus lesion baseline were calculated (ΔVHN. Data were analyzed using two-way ANOVA (p<0.05. Increased demineralization times led to increased surface softening. The lesion severity×fluoride concentration interaction was significant (p<0.001. Fluoride dose-response was observed in all groups. Lesions initially demineralized for 16 and 8 h showed similar overall rehardening (ΔVHN and more than 24 and 36 h lesions, which were similar. The 8 h lesions showed the greatest fluoride response differential (367 versus 0 ppm F which diminished with increasing lesion baseline severity. The extent of rehardening as a result of the 0 ppm F treatment increased with increasing lesion baseline severity, whereas it decreased for the fluoride treatments. In conclusion, lesion baseline severity impacts the extent of the fluoride dose-response.

An effective approach of lesion segmentation within the breast ultrasound image based on the cellular automata principle.

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Liu, Yan; Cheng, H D; Huang, Jianhua; Zhang, Yingtao; Tang, Xianglong

2012-10-01

In this paper, a novel lesion segmentation within breast ultrasound (BUS) image based on the cellular automata principle is proposed. Its energy transition function is formulated based on global image information difference and local image information difference using different energy transfer strategies. First, an energy decrease strategy is used for modeling the spatial relation information of pixels. For modeling global image information difference, a seed information comparison function is developed using an energy preserve strategy. Then, a texture information comparison function is proposed for considering local image difference in different regions, which is helpful for handling blurry boundaries. Moreover, two neighborhood systems (von Neumann and Moore neighborhood systems) are integrated as the evolution environment, and a similarity-based criterion is used for suppressing noise and reducing computation complexity. The proposed method was applied to 205 clinical BUS images for studying its characteristic and functionality, and several overlapping area error metrics and statistical evaluation methods are utilized for evaluating its performance. The experimental results demonstrate that the proposed method can handle BUS images with blurry boundaries and low contrast well and can segment breast lesions accurately and effectively.

Treadmill sideways gait training with visual blocking for patients with brain lesions.

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Kim, Tea-Woo; Kim, Yong-Wook

2014-09-01

[Purpose] The aim of this study was to verify the effect of sideways treadmill training with and without visual blocking on the balance and gait function of patients with brain lesions. [Subjects] Twenty-four stroke and traumatic brain injury subjects participated in this study. They were divided into two groups: an experimental group (12 subjects) and a control group (12 subjects). [Methods] Each group executed a treadmill training session for 20 minutes, three times a week, for 6 weeks. The sideways gait training on the treadmill was performed with visual blocking by the experimental group and with normal vision by the control group. A Biodex Gait Trainer 2 was used to assess the gait function. It was used to measure walking speed, walking distance, step length, and stance time on each foot. The Five-Times-Sit-To-Stand test (FTSST) and Timed Up and Go test (TUG) were used as balance measures. [Results] The sideways gait training with visual blocking group showed significantly improved walking speed, walking distance, step length, and stance time on each foot after training; FTSST and TUG times also significantly improved after training in the experimental group. Compared to the control group, the experimental group showed significant increases in stance time on each foot. [Conclusion] Sideways gait training on a treadmill with visual blocking performed by patients with brain lesions significantly improved their balance and gait function.

DMFC performance and methanol cross-over: Experimental analysis and model validation

Energy Technology Data Exchange (ETDEWEB)

Casalegno, A.; Marchesi, R. [Dipartimento di Energia, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

2008-10-15

A combined experimental and modelling approach is proposed to analyze methanol cross-over and its effect on DMFC performance. The experimental analysis is performed in order to allow an accurate investigation of methanol cross-over influence on DMFC performance, hence measurements were characterized in terms of uncertainty and reproducibility. The findings suggest that methanol cross-over is mainly determined by diffusion transport and affects cell performance partly via methanol electro-oxidation at the cathode. The modelling analysis is carried out to further investigate methanol cross-over phenomenon. A simple model evaluates the effectiveness of two proposed interpretations regarding methanol cross-over and its effects. The model is validated using the experimental data gathered. Both the experimental analysis and the proposed and validated model allow a substantial step forward in the understanding of the main phenomena associated with methanol cross-over. The findings confirm the possibility to reduce methanol cross-over by optimizing anode feeding. (author)

Oropharynx lesion biopsy

Science.gov (United States)

... as papilloma) Fungal infections (such as candida) Histoplasmosis Oral lichen planus Precancerous sore (leukoplakia) Viral infections (such as Herpes simplex) Risks Risks of the procedure may ... Throat lesion biopsy; Biopsy - mouth or throat; Mouth lesion biopsy; Oral cancer - biopsy ...

Morphofunctional analysis of experimental model of esophageal achalasia in rats.

Science.gov (United States)

Sabirov, A G; Raginov, I S; Burmistrov, M V; Chelyshev, Y A; Khasanov, R Sh; Moroshek, A A; Grigoriev, P N; Zefirov, A L; Mukhamedyarov, M A

2010-10-01

We carried out a detailed analysis of rat model of esophageal achalasia previously developed by us. Manifest morphological and functional disorders were observed in experimental achalasia: hyperplasia of the squamous epithelium, reduced number of nerve fibers, excessive growth of fibrous connective tissue in the esophageal wall, high contractile activity of the lower esophageal sphincter, and reduced motility of the longitudinal muscle layer. Changes in rat esophagus observed in experimental achalasia largely correlate with those in esophageal achalasia in humans. Hence, our experimental model can be used for the development of new methods of disease treatment.

The Effect of Silybum marianum on GFAP and Spatial Memory in a Mouse Model of Alzheimer\\'s Disease

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A Hadinia

2010-01-01

Full Text Available Introduction & Objective: Studies have shown that Silybum marianum have high levels of antioxidant polyphenolic substances and have neuro-protective effects on neurodegenerative diseases. Accordingly, this study was conducted to determine the possible effect of Silybum marianum on expression of and spatial memory in a mouse model of Alzheimer's disease. Materials & Methods: This experimental study was conducted at Yasuj University of Medical Sciences in 2009. Thirty adult male Wistar rats were allocated in three groups: sham group, experimental group, and lesion group, each consisting of ten rats. The experimental and lesion groups received Ibotonic acid of the NBM nucleus in stereotaxic apparatus whereas the sham group underwent surgical procedure without any injection. The experimental group received 200mg/kg of Silybum mirianum extract orally, diluted in 1% Arabic gum. Also the sham group received 1% Arabic gum every day for four weeks. The lesion group did not receive anything. The behavioral assessment was measured, after treatment , by using of Y maze test on day 7 and 28 in all groups. The ELISA method was used to measure the GFAP level in Hippocamp at the end of behavioral assessment. The collected data was analyzed by the SPSS software using ANOVA and Repeated Measures of Analysis Variance tests. Results:Improvement of behavioral performance of the experimental animals compared to the lesion and sham groups were increased significantly on day 7 and 28 (P <0.01 & P <0.001 respectively. The ELISA method showed that the level of the GFAP synthesis decreased in the experimental group compared to the lesion and sham groups (P <0.001. Conclusion: The Silybum marianum plant has a protective effect on the nerve tissue in a mouse model of Alzheimer's disease by decreasing of the GFAP synthesis and lead to the improvement of behavioral performance. :

The potential cost-effectiveness of the Diamondback 360® Coronary Orbital Atherectomy System for treating de novo, severely calcified coronary lesions: an economic modeling approach

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Chambers, Jeffrey; Généreux, Philippe; Lee, Arthur; Lewin, Jack; Young, Christopher; Crittendon, Janna; Mann, Marita; Garrison, Louis P.

2015-01-01

Background: Patients who undergo percutaneous coronary intervention (PCI) for severely calcified coronary lesions have long been known to have worse clinical and economic outcomes than patients with no or mildly calcified lesions. We sought to assess the likely cost-effectiveness of using the Diamondback 360® Orbital Atherectomy System (OAS) in the treatment of de novo, severely calcified lesions from a health-system perspective. Methods and results: In the absence of a head-to-head trial and long-term follow up, cost-effectiveness was based on a modeled synthesis of clinical and economic data. A cost-effectiveness model was used to project the likely economic impact. To estimate the net cost impact, the cost of using the OAS technology in elderly (⩾ 65 years) Medicare patients with de novo severely calcified lesions was compared with cost offsets. Elderly OAS patients from the ORBIT II trial (Evaluate the Safety and Efficacy of OAS in Treating Severely Calcified Coronary Lesions) [ClinicalTrials.gov identifier: NCT01092426] were indirectly compared with similar patients using observational data. For the index procedure, the comparison was with Medicare data, and for both revascularization and cardiac death in the following year, the comparison was with a pooled analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI)/Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trials. After adjusting for differences in age, gender, and comorbidities, the ORBIT II mean index procedure costs were 17% (p < 0.001) lower, approximately US$2700. Estimated mean revascularization costs were lower by US$1240 in the base case. These cost offsets in the first year, on average, fully cover the cost of the device with an additional 1.2% cost savings. Even in the low-value scenario, the use of the OAS is cost-effective with a cost per life-year gained of US$11,895. Conclusions: Based on economic modeling

Robust segmentation of focal lesions on multi-sequence MRI in multiple sclerosis

International Nuclear Information System (INIS)

Garcia-Lorenzo, Daniel

2010-01-01

Multiple sclerosis (MS) affects around 80.000 people in France. Magnetic resonance imaging (MRI) is an essential tool for diagnosis of MS and MRI-derived surrogate markers such as MS lesion volumes are often used as measures in MS clinical trials for the development of new treatments. The manual segmentation of these MS lesions is a time-consuming task that shows high inter- and intra-rater variability. We developed an automatic work flow for the segmentation of focal MS lesions on MRI. The segmentation method is based on the robust estimation of a parametric model of the intensities of the brain; lesions are detected as outliers to the model. We proposed two methods to include spatial information in the segmentation using mean shift and graph cut. We performed a quantitative evaluation of our work flow using synthetic and clinical images of two different centers to verify its accuracy and robustness. (author)

Effects of Erdosteine on Experimental Acute Pancreatitis Model.

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Karapolat, Banu; Karapolat, Sami; Gurleyik, Emin; Yasar, Mehmet

2017-10-01

To create acute pancreatitis condition experimentally in rats using cerulein, and to reveal histopathological effects in pancreatic tissue with erdosteine. An experimental study. Department of General Surgery, Duzce University, Turkey, from June to October 2014. Thirty male Wistar albino rats were divided into three groups. No procedures were applied to Group 1. The rats in Group 2 and Group 3 were injected cerulein, to establish an experimental pancreatitis model and the blood amylase and lipase values were examined. The rats in Group 3 were given 10 mg/kg erdosteine. This treatment was continued for another 2 days and the rats were sacrificed. The pancreatic tissues were examined histopathologically for edema, inflammation, acinar necrosis, fat necrosis, and vacuolization. The lipase and amylase values and the histopathological examination of pancreatic tissues evidenced that the experimental acute pancreatitis model was established and edema, inflammation, acinar necrosis, fat necrosis, and vacuolization were observed in the pancreatic tissues. The statistical results suggest that erdosteine can decrease the edema, inflammation, acinar necrosis, fat necrosis and vacuolization scores in the tissues. The severity of acute pancreatitis, induced by cerulein in rats, is reduced with the use of erdosteine.

Deficit-Lesion Correlations in Syntactic Comprehension in Aphasia

Science.gov (United States)

Caplan, David; Michaud, Jennifer; Hufford, Rebecca; Makris, Nikos

2015-01-01

The effects of lesions on syntactic comprehension were studied in thirty one people with aphasia (PWA). Participants were tested for the ability to parse and interpret four types of syntactic structures and elements -- passives, object extracted relative clauses, reflexives and pronouns – in three tasks – object manipulation, sentence picture matching with full sentence presentation and sentence picture matching with self-paced listening presentation. Accuracy, end-of-sentence RT and self-paced listening times for each word were measured. MR scans were obtained and analyzed for total lesion volume and for lesion size in 48 cortical areas. Lesion size in several areas of the left hemisphere was related to accuracy in particular sentence types in particular tasks and to self-paced listening times for critical words in particular sentence types. The results support a model of brain organization that includes areas that are specialized for the combination of particular syntactic and interpretive operations and the use of the meanings produced by those operations to accomplish task-related operations. PMID:26688433

Deficit-lesion correlations in syntactic comprehension in aphasia.

Science.gov (United States)

Caplan, David; Michaud, Jennifer; Hufford, Rebecca; Makris, Nikos

2016-01-01

The effects of lesions on syntactic comprehension were studied in thirty-one people with aphasia (PWA). Participants were tested for the ability to parse and interpret four types of syntactic structures and elements - passives, object extracted relative clauses, reflexives and pronouns - in three tasks - object manipulation, sentence picture matching with full sentence presentation and sentence picture matching with self-paced listening presentation. Accuracy, end-of-sentence RT and self-paced listening times for each word were measured. MR scans were obtained and analyzed for total lesion volume and for lesion size in 48 cortical areas. Lesion size in several areas of the left hemisphere was related to accuracy in particular sentence types in particular tasks and to self-paced listening times for critical words in particular sentence types. The results support a model of brain organization that includes areas that are specialized for the combination of particular syntactic and interpretive operations and the use of the meanings produced by those operations to accomplish task-related operations. Copyright © 2015 Elsevier Inc. All rights reserved.

Photoacoustic discrimination of vascular and pigmented lesions using classical and Bayesian methods

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Swearingen, Jennifer A.; Holan, Scott H.; Feldman, Mary M.; Viator, John A.

2010-01-01

Discrimination of pigmented and vascular lesions in skin can be difficult due to factors such as size, subungual location, and the nature of lesions containing both melanin and vascularity. Misdiagnosis may lead to precancerous or cancerous lesions not receiving proper medical care. To aid in the rapid and accurate diagnosis of such pathologies, we develop a photoacoustic system to determine the nature of skin lesions in vivo. By irradiating skin with two laser wavelengths, 422 and 530 nm, we induce photoacoustic responses, and the relative response at these two wavelengths indicates whether the lesion is pigmented or vascular. This response is due to the distinct absorption spectrum of melanin and hemoglobin. In particular, pigmented lesions have ratios of photoacoustic amplitudes of approximately 1.4 to 1 at the two wavelengths, while vascular lesions have ratios of about 4.0 to 1. Furthermore, we consider two statistical methods for conducting classification of lesions: standard multivariate analysis classification techniques and a Bayesian-model-based approach. We study 15 human subjects with eight vascular and seven pigmented lesions. Using the classical method, we achieve a perfect classification rate, while the Bayesian approach has an error rate of 20%.

Experimental tests of proton spin models

International Nuclear Information System (INIS)

Ramsey, G.P.; Argonne National Lab., IL

1989-01-01

We have developed models for the spin-weighted quark and gluon distribution in a longitudinally polarized proton. The model parameters are determined from current algebra sum rules and polarized deep-inelastic scattering data. A number of different scenarios are presented for the fraction of spin carried the constituent parton distributions. A possible long-range experimental program is suggested for measuring various hard scattering processes using polarized lepton and proton beams. With the knowledge gained from these experiments, we can begin to understand the parton contributions to the proton spin. 28 refs., 5 figs

Hippocampal-dependent spatial memory in the water maze is preserved in an experimental model of temporal lobe epilepsy in rats.

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Marion Inostroza

Full Text Available Cognitive impairment is a major concern in temporal lobe epilepsy (TLE. While different experimental models have been used to characterize TLE-related cognitive deficits, little is known on whether a particular deficit is more associated with the underlying brain injuries than with the epileptic condition per se. Here, we look at the relationship between the pattern of brain damage and spatial memory deficits in two chronic models of TLE (lithium-pilocarpine, LIP and kainic acid, KA from two different rat strains (Wistar and Sprague-Dawley using the Morris water maze and the elevated plus maze in combination with MRI imaging and post-morten neuronal immunostaining. We found fundamental differences between LIP- and KA-treated epileptic rats regarding spatial memory deficits and anxiety. LIP-treated animals from both strains showed significant impairment in the acquisition and retention of spatial memory, and were unable to learn a cued version of the task. In contrast, KA-treated rats were differently affected. Sprague-Dawley KA-treated rats learned less efficiently than Wistar KA-treated animals, which performed similar to control rats in the acquisition and in a probe trial testing for spatial memory. Different anxiety levels and the extension of brain lesions affecting the hippocampus and the amydgala concur with spatial memory deficits observed in epileptic rats. Hence, our results suggest that hippocampal-dependent spatial memory is not necessarily affected in TLE and that comorbidity between spatial deficits and anxiety is more related with the underlying brain lesions than with the epileptic condition per se.

Ultra-low-dose lung screening CT with model-based iterative reconstruction: an assessment of image quality and lesion conspicuity.

Science.gov (United States)

Ju, Yun Hye; Lee, Geewon; Lee, Ji Won; Hong, Seung Baek; Suh, Young Ju; Jeong, Yeon Joo

2018-05-01

Background Reducing radiation dose inevitably increases image noise, and thus, it is important in low-dose computed tomography (CT) to maintain image quality and lesion detection performance. Purpose To assess image quality and lesion conspicuity of ultra-low-dose CT with model-based iterative reconstruction (MBIR) and to determine a suitable protocol for lung screening CT. Material and Methods A total of 120 heavy smokers underwent lung screening CT and were randomly and equally assigned to one of five groups: group 1 = 120 kVp, 25 mAs, with FBP reconstruction; group 2 = 120 kVp, 10 mAs, with MBIR; group 3 = 100 kVp, 15 mAs, with MBIR; group 4 = 100 kVp, 10 mAs, with MBIR; and group 5 = 100 kVp, 5 mAs, with MBIR. Two radiologists evaluated intergroup differences with respect to radiation dose, image noise, image quality, and lesion conspicuity using the Kruskal-Wallis test and the Chi-square test. Results Effective doses were 61-87% lower in groups 2-5 than in group 1. Image noises in groups 1 and 5 were significantly higher than in the other groups ( P image quality was best in group 1, but diagnostic acceptability of overall image qualities in groups 1-3 was not significantly different (all P values > 0.05). Lesion conspicuities were similar in groups 1-4, but were significantly poorer in group 5. Conclusion Lung screening CT with MBIR obtained at 100 kVp and 15 mAs enables a ∼60% reduction in radiation dose versus low-dose CT, while maintaining image quality and lesion conspicuity.

Differentiation of benign and malignant lung lesions: Dual-Energy Computed Tomography findings

International Nuclear Information System (INIS)

González-Pérez, Víctor; Arana, Estanislao; Barrios, María; Bartrés, Albert; Cruz, Julia; Montero, Rafael; González, Manuel; Deltoro, Carlos; Martínez-Pérez, Encarnación; De Aguiar-Quevedo, Karol; Arrarás, Miguel

2016-01-01

Purpose: To determine whether parameters generated by Dual-Energy Computed Tomography (DECT) can distinguish malignant from benign lung lesions. Methods: A prospective review of 125 patients with 126 lung lesions (23 benign and 103 malignant) who underwent lung DECT during arterial phase. All lesions were confirmed by tissue sampling. A radiologist semi-automatically contoured lesions and placed regions of interest (ROIs) in paravertebral muscle (PVM) for normalization. Variables related to absorption in Hounsfield units (HU), effective atomic number (Z eff ), iodine concentration (ρ I ) and spectral CT curves were assessed. Receiver operating characteristic (ROC) curves were generated to calculate sensitivity and specificity as predictors of malignancy. Multivariate logistic regression analysis was performed. Results: Reproducibility of measures normalized with PVM was poor. Bivariate analysis showed minimum Z eff and normalized mean Z eff to be statistically significant (p = 0.001), with area under the curve (AUC) values: 0.66 (CI 95% 0.54–0.80) and 0.72 (CI 95%, 0.60–0.84), respectively. Logistic regression models showed no differences between raw and normalized measurements. In both models, minimum HU (OR: 0.9) and size (OR: 0.1) were predictive of benign lesions. Conclusions: A quantitative approach to DECT using raw measurements is simpler than logistic regression models. Normalization to PVM was not clinically reliable due to its poor reproducibility. Further studies are needed to confirm our findings.

Differentiation of benign and malignant lung lesions: Dual-Energy Computed Tomography findings.

Science.gov (United States)

González-Pérez, Víctor; Arana, Estanislao; Barrios, María; Bartrés, Albert; Cruz, Julia; Montero, Rafael; González, Manuel; Deltoro, Carlos; Martínez-Pérez, Encarnación; De Aguiar-Quevedo, Karol; Arrarás, Miguel

2016-10-01

To determine whether parameters generated by Dual-Energy Computed Tomography (DECT) can distinguish malignant from benign lung lesions. A prospective review of 125 patients with 126 lung lesions (23 benign and 103 malignant) who underwent lung DECT during arterial phase. All lesions were confirmed by tissue sampling. A radiologist semi-automatically contoured lesions and placed regions of interest (ROIs) in paravertebral muscle (PVM) for normalization. Variables related to absorption in Hounsfield units (HU), effective atomic number (Zeff), iodine concentration (ρI) and spectral CT curves were assessed. Receiver operating characteristic (ROC) curves were generated to calculate sensitivity and specificity as predictors of malignancy. Multivariate logistic regression analysis was performed. Reproducibility of measures normalized with PVM was poor. Bivariate analysis showed minimum Zeff and normalized mean Zeff to be statistically significant (p=0.001), with area under the curve (AUC) values: 0.66 (CI 95% 0.54-0.80) and 0.72 (CI 95%, 0.60-0.84), respectively. Logistic regression models showed no differences between raw and normalized measurements. In both models, minimum HU (OR: 0.9) and size (OR: 0.1) were predictive of benign lesions. A quantitative approach to DECT using raw measurements is simpler than logistic regression models. Normalization to PVM was not clinically reliable due to its poor reproducibility. Further studies are needed to confirm our findings. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

DMFC anode polarization: Experimental analysis and model validation

Energy Technology Data Exchange (ETDEWEB)

Casalegno, A.; Marchesi, R. [Dipartimento di Energetica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

2008-01-03

Anode two-phase flow has an important influence on DMFC performance and methanol crossover. In order to elucidate two-phase flow influence on anode performance, in this work, anode polarization is investigated combining experimental and modelling approach. A systematic experimental analysis of operating conditions influence on anode polarization is presented. Hysteresis due to operating condition is observed; experimental results suggest that it arises from methanol accumulation and has to be considered in evaluating DMFC performances and measurements reproducibility. A model of DMFC anode polarization is presented and utilised as tool to investigate anode two-phase flow. The proposed analysis permits one to produce a confident interpretation of the main involved phenomena. In particular, it confirms that methanol electro-oxidation kinetics is weakly dependent on methanol concentration and that methanol transport in gas phase produces an important contribution in anode feeding. Moreover, it emphasises the possibility to optimise anode flow rate in order to improve DMFC performance and reduce methanol crossover. (author)

Experimental designs for autoregressive models applied to industrial maintenance

International Nuclear Information System (INIS)

Amo-Salas, M.; López-Fidalgo, J.; Pedregal, D.J.

2015-01-01

Some time series applications require data which are either expensive or technically difficult to obtain. In such cases scheduling the points in time at which the information should be collected is of paramount importance in order to optimize the resources available. In this paper time series models are studied from a new perspective, consisting in the use of Optimal Experimental Design setup to obtain the best times to take measurements, with the principal aim of saving costs or discarding useless information. The model and the covariance function are expressed in an explicit form to apply the usual techniques of Optimal Experimental Design. Optimal designs for various approaches are computed and their efficiencies are compared. The methods working in an application of industrial maintenance of a critical piece of equipment at a petrochemical plant are shown. This simple model allows explicit calculations in order to show openly the procedure to find the correlation structure, needed for computing the optimal experimental design. In this sense the techniques used in this paper to compute optimal designs may be transferred to other situations following the ideas of the paper, but taking into account the increasing difficulty of the procedure for more complex models. - Highlights: • Optimal experimental design theory is applied to AR models to reduce costs. • The first observation has an important impact on any optimal design. • Either the lack of precision or small starting observations claim for large times. • Reasonable optimal times were obtained relaxing slightly the efficiency. • Optimal designs were computed in a predictive maintenance context

Theoretical-experimental modelling of the momentum equation for PWR reactor steam generators

International Nuclear Information System (INIS)

Rodrigues, L.A.H.

1994-01-01

A mathematical model in steady-state conditions of the momentum equation at the secondary side of a vertical U-tube steam generator with recirculation is presented. The U-tube test section was the 150 bar - Circuito Termoidraulico Experimental - CTE-150. This facility is a Experimental Thermal-hydraulic Circuit and operates at the same conditions (pressure and temperature) of a typical PWR reactor. A comparison between the Homogeneous and Separate Flow models was done. those models were verified and compared with experimental data for several operational conditions. The results show that the model fits very well the experimental data and seems to be appropriate to study water recirculation of a steam generator secondary side. (author)

Experimental animal data and modeling of late somatic effects

International Nuclear Information System (INIS)

Fry, R.J.M.

1988-01-01

This section is restricted to radiation-induced life shortening and cancer and mainly to studies with external radiation. The emphasis will be on the experimental data that are available and the experimental systems that could provide the type of data with which to either formulate or test models. Genetic effects which are of concern are not discussed in this section. Experimental animal radiation studies fall into those that establish general principles and those that demonstrate mechanisms. General principles include the influence of dose, radiation quality, dose rate, fractionation, protraction and such biological factors as age and gender. The influence of these factors are considered as general principles because they are independent, at least qualitatively, of the species studied. For example, if an increase in the LET of the radiation causes an increased effectiveness in cancer induction in a mouse a comparable increase in effectiveness can be expected in humans. Thus, models, whether empirical or mechanistic, formulated from experimental animal data should be generally applicable

Electrochemical desalination of bricks - Experimental and modeling

DEFF Research Database (Denmark)

Skibsted, Gry; Ottosen, Lisbeth M.; Jensen, Pernille Erland

2015-01-01

Chlorides, nitrates and sulfates play an important role in the salt-decay of porous materials in buildings and monuments. Electrochemical desalination is a technology able to remove salts from such porous materials in order to stop or prevent the decay. In this paper, experimental and numerical......-contaminated bricks with respect to the monovalent ions is discussed. Comparison between the experimental and the simulation results showed that the proposed numerical model is able to predict electrochemical desalination treatments with remarkable accuracy, and it can be used as a predictive tool...

Lesion activity assessment

DEFF Research Database (Denmark)

Ekstrand, K R; Zero, D T; Martignon, S

2009-01-01

in response to cariogenic plaque as well as lesion arrest. Based on this understanding, different clinical scoring systems have been developed to assess the severity/depth and activity of lesions. A recent system has been devised by the International Caries Detection and Assessment System Committee...

Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

International Nuclear Information System (INIS)

Anfinsen, Ole-Gunnar

1999-01-01

The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks related to

Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

Energy Technology Data Exchange (ETDEWEB)

Anfinsen, Ole-Gunnar

1999-07-01

The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks

Anti-proliferative effect of extremely low frequency electromagnetic field on preneoplastic lesions formation in the rat liver

International Nuclear Information System (INIS)

Jiménez-García, Mónica Noemí; Arellanes-Robledo, Jaime; Aparicio-Bautista, Diana Ivette; Rodríguez-Segura, Miguel Ángel; Villa-Treviño, Saúl; Godina-Nava, Juan José

2010-01-01

Recently, extremely low frequency electromagnetic fields (ELF-EMF) have been studied with great interest due to their possible effects on human health. In this study, we evaluated the effect of 4.5 mT - 120 Hz ELF-EMF on the development of preneoplastic lesions in experimental hepatocarcinogenesis. Male Fischer-344 rats were subjected to the modified resistant hepatocyte model and were exposed to 4.5 mT - 120 Hz ELF-EMF. The effects of the ELF-EMF on hepatocarcinogenesis, apoptosis, proliferation and cell cycle progression were evaluated by histochemical, TUNEL assay, caspase 3 levels, immunohistochemical and western blot analyses. The application of the ELF-EMF resulted in a decrease of more than 50% of the number and the area of γ-glutamyl transpeptidase-positive preneoplastic lesions (P = 0.01 and P = 0.03, respectively) and glutathione S-transferase placental expression (P = 0.01). The number of TUNEL-positive cells and the cleaved caspase 3 levels were unaffected; however, the proliferating cell nuclear antigen, Ki-67, and cyclin D1 expression decreased significantly (P ≤ 0.03), as compared to the sham-exposure group. The application of 4.5 mT - 120 Hz ELF-EMF inhibits preneoplastic lesions chemically induced in the rat liver through the reduction of cell proliferation, without altering the apoptosis process

A Dirichlet process mixture model for automatic (18)F-FDG PET image segmentation: Validation study on phantoms and on lung and esophageal lesions.

Science.gov (United States)

Giri, Maria Grazia; Cavedon, Carlo; Mazzarotto, Renzo; Ferdeghini, Marco

2016-05-01

The aim of this study was to implement a Dirichlet process mixture (DPM) model for automatic tumor edge identification on (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) images by optimizing the parameters on which the algorithm depends, to validate it experimentally, and to test its robustness. The DPM model belongs to the class of the Bayesian nonparametric models and uses the Dirichlet process prior for flexible nonparametric mixture modeling, without any preliminary choice of the number of mixture components. The DPM algorithm implemented in the statistical software package R was used in this work. The contouring accuracy was evaluated on several image data sets: on an IEC phantom (spherical inserts with diameter in the range 10-37 mm) acquired by a Philips Gemini Big Bore PET-CT scanner, using 9 different target-to-background ratios (TBRs) from 2.5 to 70; on a digital phantom simulating spherical/uniform lesions and tumors, irregular in shape and activity; and on 20 clinical cases (10 lung and 10 esophageal cancer patients). The influence of the DPM parameters on contour generation was studied in two steps. In the first one, only the IEC spheres having diameters of 22 and 37 mm and a sphere of the digital phantom (41.6 mm diameter) were studied by varying the main parameters until the diameter of the spheres was obtained within 0.2% of the true value. In the second step, the results obtained for this training set were applied to the entire data set to determine DPM based volumes of all available lesions. These volumes were compared to those obtained by applying already known algorithms (Gaussian mixture model and gradient-based) and to true values, when available. Only one parameter was found able to significantly influence segmentation accuracy (ANOVA test). This parameter was linearly connected to the uptake variance of the tested region of interest (ROI). In the first step of the study, a calibration curve was determined to

A Dirichlet process mixture model for automatic 18F-FDG PET image segmentation: Validation study on phantoms and on lung and esophageal lesions

International Nuclear Information System (INIS)

Giri, Maria Grazia; Cavedon, Carlo; Mazzarotto, Renzo; Ferdeghini, Marco

2016-01-01

Purpose: The aim of this study was to implement a Dirichlet process mixture (DPM) model for automatic tumor edge identification on 18 F-fluorodeoxyglucose positron emission tomography ( 18 F-FDG PET) images by optimizing the parameters on which the algorithm depends, to validate it experimentally, and to test its robustness. Methods: The DPM model belongs to the class of the Bayesian nonparametric models and uses the Dirichlet process prior for flexible nonparametric mixture modeling, without any preliminary choice of the number of mixture components. The DPM algorithm implemented in the statistical software package R was used in this work. The contouring accuracy was evaluated on several image data sets: on an IEC phantom (spherical inserts with diameter in the range 10–37 mm) acquired by a Philips Gemini Big Bore PET-CT scanner, using 9 different target-to-background ratios (TBRs) from 2.5 to 70; on a digital phantom simulating spherical/uniform lesions and tumors, irregular in shape and activity; and on 20 clinical cases (10 lung and 10 esophageal cancer patients). The influence of the DPM parameters on contour generation was studied in two steps. In the first one, only the IEC spheres having diameters of 22 and 37 mm and a sphere of the digital phantom (41.6 mm diameter) were studied by varying the main parameters until the diameter of the spheres was obtained within 0.2% of the true value. In the second step, the results obtained for this training set were applied to the entire data set to determine DPM based volumes of all available lesions. These volumes were compared to those obtained by applying already known algorithms (Gaussian mixture model and gradient-based) and to true values, when available. Results: Only one parameter was found able to significantly influence segmentation accuracy (ANOVA test). This parameter was linearly connected to the uptake variance of the tested region of interest (ROI). In the first step of the study, a calibration curve

Contact Modelling in Resistance Welding, Part II: Experimental Validation

DEFF Research Database (Denmark)

Song, Quanfeng; Zhang, Wenqi; Bay, Niels

2006-01-01

Contact algorithms in resistance welding presented in the previous paper are experimentally validated in the present paper. In order to verify the mechanical contact algorithm, two types of experiments, i.e. sandwich upsetting of circular, cylindrical specimens and compression tests of discs...... with a solid ring projection towards a flat ring, are carried out at room temperature. The complete algorithm, involving not only the mechanical model but also the thermal and electrical models, is validated by projection welding experiments. The experimental results are in satisfactory agreement...

Hybrid Electric Vehicle Experimental Model with CAN Network Real Time Control

Directory of Open Access Journals (Sweden)

RATOI, M.

2010-05-01

Full Text Available In this paper an experimental model with a distributed control system of a hybrid electrical vehicle is presented. A communication CAN network of high speed (1 Mbps assures a distributed control of the all components. The modeling and the control of different operating regimes are realized on an experimental test-bench of a hybrid electrical vehicle. The experimental results concerning the variations of the mains variables (currents, torques, speeds are presented.

MALIGNANCY IN LARGE COLORECTAL LESIONS

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Carlos Eduardo Oliveira dos SANTOS

2014-09-01

Full Text Available Context The size of colorectal lesions, besides a risk factor for malignancy, is a predictor for deeper invasion Objectives To evaluate the malignancy of colorectal lesions ≥20 mm. Methods Between 2007 and 2011, 76 neoplasms ≥20 mm in 70 patients were analyzed Results The mean age of the patients was 67.4 years, and 41 were women. Mean lesion size was 24.7 mm ± 6.2 mm (range: 20 to 50 mm. Half of the neoplasms were polypoid and the other half were non-polypoid. Forty-two (55.3% lesions were located in the left colon, and 34 in the right colon. There was a high prevalence of III L (39.5% and IV (53.9% pit patterns. There were 72 adenomas and 4 adenocarcinomas. Malignancy was observed in 5.3% of the lesions. Thirty-three lesions presented advanced histology (adenomas with high-grade dysplasia or early adenocarcinoma, with no difference in morphology and site. Only one lesion (1.3% invaded the submucosa. Lesions larger than 30 mm had advanced histology (P = 0.001. The primary treatment was endoscopic resection, and invasive carcinoma was referred to surgery. Recurrence rate was 10.6%. Conclusions Large colorectal neoplasms showed a low rate of malignancy. Endoscopic treatment is an effective therapy for these lesions.

Development of Snake Fungal Disease after Experimental Challenge with Ophidiomyces ophiodiicola in Cottonmouths (Agkistrodon piscivorous.

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Matthew C Allender

Full Text Available Snake fungal disease (SFD is a clinical syndrome associated with dermatitis, myositis, osteomyelitis, and pneumonia in several species of free-ranging snakes in the US. The causative agent has been suggested as Ophidiomyces ophiodiicola, but other agents may contribute to the syndrome and the pathogenesis is not understood. To understand the role of O. ophiodiicola in SFD, a cottonmouth snake model of SFD was designed. Five cottonmouths (Agkistrodon piscivorous were experimentally challenged by nasolabial pit inoculation with a pure culture of O. ophiodiicola. Development of skin lesions or facial swelling at the site of inoculation was observed in all snakes. Twice weekly swabs of the inoculation site revealed variable presence of O. ophiodiicola DNA by qPCR in all five inoculated snakes for 3 to 58 days post-inoculation; nasolabial flushes were not a useful sampling method for detection. Inoculated snakes had a 40% mortality rate. All inoculated snakes had microscopic lesions unilaterally on the side of the swabbed nasolabial pit, including erosions to ulcerations and heterophilic dermatitis. All signs were consistent with SFD; however, the severity of lesions varied in individual snakes, and fungal hyphae were only observed in 3 of 5 inoculated snakes. These three snakes correlated with post-mortem tissue qPCR evidence of O. ophiodiicola. The findings of this study conclude that O. ophiodiicola inoculation in a cottonmouth snake model leads to disease similar to SFD, although lesion severity and the fungal load are quite variable within the model. Future studies may utilize this model to further understand the pathogenesis of this disease and develop management strategies that mitigate disease effects, but investigation of other models with less variability may be warranted.

Concurrent Reflectance Confocal Microscopy and Laser Doppler Flowmetry to Improve Skin Cancer Imaging: A Monte Carlo Model and Experimental Validation

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Alireza Mowla

2016-09-01

Full Text Available Optical interrogation of suspicious skin lesions is standard care in the management of skin cancer worldwide. Morphological and functional markers of malignancy are often combined to improve expert human diagnostic power. We propose the evaluation of the combination of two independent optical biomarkers of skin tumours concurrently. The morphological modality of reflectance confocal microscopy (RCM is combined with the functional modality of laser Doppler flowmetry, which is capable of quantifying tissue perfusion. To realize the idea, we propose laser feedback interferometry as an implementation of RCM, which is able to detect the Doppler signal in addition to the confocal reflectance signal. Based on the proposed technique, we study numerical models of skin tissue incorporating two optical biomarkers of malignancy: (i abnormal red blood cell velocities and concentrations and (ii anomalous optical properties manifested through tissue confocal reflectance, using Monte Carlo simulation. We also conduct a laboratory experiment on a microfluidic channel containing a dynamic turbid medium, to validate the efficacy of the technique. We quantify the performance of the technique by examining a signal to background ratio (SBR in both the numerical and experimental models, and it is shown that both simulated and experimental SBRs improve consistently using this technique. This work indicates the feasibility of an optical instrument, which may have a role in enhanced imaging of skin malignancies.

Correlation between local hemodynamics and lesion distribution in a novel aortic regurgitation murine model of atherosclerosis.

Science.gov (United States)

Hoi, Yiemeng; Zhou, Yu-Qing; Zhang, Xiaoli; Henkelman, R Mark; Steinman, David A

2011-05-01

Following surgical induction of aortic valve regurgitation (AR), extensive atherosclerotic plaque development along the descending thoracic and abdominal aorta of Ldlr⁻/⁻ mice has been reported, with distinct spatial distributions suggestive of a strong local hemodynamic influence. The objective of this study was to test, using image-based computational fluid dynamics (CFD), whether this is indeed the case. The lumen geometry was reconstructed from micro-CT scanning of a control Ldlr⁻/⁻ mouse, and CFD simulations were carried out for both AR and control flow conditions derived from Doppler ultrasound measurements and literature data. Maps of time-averaged wall shear stress magnitude (TAWSS), oscillatory shear index (OSI) and relative residence time (RRT) were compared against the spatial distributions of plaque stained with oil red O, previously acquired in a group of AR and control mice. Maps of OSI and RRT were found to be consistent with plaque distributions in the AR mice and the absence of plaque in the control mice. TAWSS was uniformly lower under control vs. AR flow conditions, suggesting that levels (> 100 dyn/cm²) exceeded those required to alone induce a pro-atherogenic response. Simulations of a straightened CFD model confirmed the importance of anatomical curvature for explaining the spatial distribution of lesions in the AR mice. In summary, oscillatory and retrograde flow induced in the AR mice, without concomitant low shear, may exacerbate or accelerate lesion formation, but the distinct anatomical curvature of the mouse aorta is responsible for the spatial distribution of lesions.

CT diagnosis of sellar and juxtasellar lesions, 3. Non-tumorous lesions

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Tatsuya [Nagoya Univ. (Japan). Faculty of Medicine

1982-08-01

A study is made of the usefulness and limitations of the CT diagnosis of sellar and juxtasellar lesions other than tumors. This study is based on 112 verified cases at Nagoya University Hospital from October, 1976, to December, 1981. The lesions included in this study are classified into four groups: vascular, inflammatory, traumatic lesion, and congenital anomaly. Although cerebral angiography is the cardinal method for the diagnosis of vascular lesions, CT is useful for the evaluation of a giant aneurysm, the localization of bleeding, or infarction by a ruptured aneurysm. Radiation brain necrosis, a special form of vascular lesion, can also be diagnosed if the critical analysis is made after previous irradiation. CT findings are helpful for the local diagnosis of acute inflammatory lesions, such as basal meningitis or abscess, but specific diagnosis is made on the basis of clinical signs and CSF study. Abnormal CT findings are obtained from a chronic inflammatory process, such as arachnoiditis adhesiva, glanuloma, or mucocele. Differential diagnosis is necessary with brain tumors. The CT findings of an arachnoid cyst are often diagnostic. Metrizamide or air cisternography, either combined with CT or without it, is important for the diagnosis of basal meningoencephalocele and hypothalamic hamaroma. Pneumocephalus and an intracranial foreign body resulting from a head injury can be diagnosed by plain skull and CT. The diagnosis of CSF leakage or prolapse cerebri associated with a skull-base fracture has been most difficult, but even it is possible by a combination of polytomography and high-resolution CT with metrizamide cisternography.

GLP-1 improves neuropathology after murine cold lesion brain trauma

DEFF Research Database (Denmark)

DellaValle, Brian; Hempel, Casper; Johansen, Flemming Fryd

2014-01-01

brain trauma. METHODS: Severe trauma was induced with a stereotactic cryo-lesion in mice and thereafter treated with vehicle, liraglutide, or liraglutide + GLP-1 receptor antagonist. A therapeutic window was established and lesion size post-trauma was determined. Reactive oxygen species were visualized......-neurodegenerative proteins increased with Lira-driven CREB activation. INTERPRETATION: These results show that Lira has potent effects after experimental trauma in mice and thus should be considered a candidate for critical care intervention post-injury. Moreover, activation of CREB in the brain by Lira - described......OBJECTIVES: In this study, we address a gap in knowledge regarding the therapeutic potential of acute treatment with a glucagon-like peptide-1 (GLP-1) receptor agonist after severe brain trauma. Moreover, it remains still unknown whether GLP-1 treatment activates the protective, anti...

Endothelial Dysfunction in Experimental Models of Arterial Hypertension: Cause or Consequence?

Directory of Open Access Journals (Sweden)

Iveta Bernatova

2014-01-01

Full Text Available Hypertension is a risk factor for other cardiovascular diseases and endothelial dysfunction was found in humans as well as in various commonly employed animal experimental models of arterial hypertension. Data from the literature indicate that, in general, endothelial dysfunction would not be the cause of experimental hypertension and may rather be secondary, that is, resulting from high blood pressure (BP. The initial mechanism of endothelial dysfunction itself may be associated with a lack of endothelium-derived relaxing factors (mainly nitric oxide and/or accentuation of various endothelium-derived constricting factors. The involvement and role of endothelium-derived factors in the development of endothelial dysfunction in individual experimental models of hypertension may vary, depending on the triggering stimulus, strain, age, and vascular bed investigated. This brief review was focused on the participation of endothelial dysfunction, individual endothelium-derived factors, and their mechanisms of action in the development of high BP in the most frequently used rodent experimental models of arterial hypertension, including nitric oxide deficient models, spontaneous (prehypertension, stress-induced hypertension, and selected pharmacological and diet-induced models.

Influence of social mixing and group size on skin lesions and mounting in organic entire male pigs

DEFF Research Database (Denmark)

Thomsen, Rikke; Edwards, Sandra A; Rousing, Tine

2016-01-01

in management procedures and production system might be needed. Elements from the organic pig production system might be beneficial in this aspect. The aim of this article is to investigate the effect of grouping strategy including social mixing and group size on levels of mounting behaviour and skin lesions...... at weaning. A second mixing occurred at insertion to fattening pens for pigs being regrouped. Counting of skin lesions (1348 or 1124 pigs) and registration of mounting behaviour (1434 or 1258 pigs) were done on two occasions during the experimental period. No interactive effects were found between social...... mixing and group size on either skin lesions or mounting frequency. Herd differences were found for both mounting frequency and number of skin lesions. No association between skin lesions and mounting were revealed. Social mixing and group size were shown as interacting effects with herds on mounting...

Experimental animal modelling for TB vaccine development

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Pere-Joan Cardona

2017-03-01

Full Text Available Research for a novel vaccine to prevent tuberculosis is an urgent medical need. The current vaccine, BCG, has demonstrated a non-homogenous efficacy in humans, but still is the gold standard to be improved upon. In general, the main indicator for testing the potency of new candidates in animal models is the reduction of the bacillary load in the lungs at the acute phase of the infection. Usually, this reduction is similar to that induced by BCG, although in some cases a weak but significant improvement can be detected, but none of candidates are able to prevent establishment of infection. The main characteristics of several laboratory animals are reviewed, reflecting that none are able to simulate the whole characteristics of human tuberculosis. As, so far, no surrogate of protection has been found, it is important to test new candidates in several models in order to generate convincing evidence of efficacy that might be better than that of BCG in humans. It is also important to investigate the use of “in silico” and “ex vivo” models to better understand experimental data and also to try to replace, or at least reduce and refine experimental models in animals.

Experimental Validation of a Permeability Model for Enrichment Membranes

International Nuclear Information System (INIS)

Orellano, Pablo; Brasnarof, Daniel; Florido Pablo

2003-01-01

An experimental loop with a real scale diffuser, in a single enrichment-stage configuration, was operated with air at different process conditions, in order to characterize the membrane permeability.Using these experimental data, an analytical geometric-and-morphologic-based model was validated.It is conclude that a new set of independent measurements, i.e. enrichment, is necessary in order to fully characterize diffusers, because of its internal parameters are not univocally determinated with permeability experimental data only

Investigation of wax precipitation in crude oil: Experimental and modeling

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Taraneh Jafari Behbahani

2015-09-01

Full Text Available In this work, a series of experiments were carried to investigation of rheological behavior of crude oil using waxy crude oil sample in the absence/presence of flow improver such as ethylene-vinyl acetate copolymer. The rheological data covered the temperature range of 5–30 °C. The results indicated that the performance of flow improver was dependent on its molecular weight. Addition of small quantities of flow improver, can improve viscosity and pour point of crude oil. Also, an Artificial Neural Network (ANN model using Multi-Layer Perceptron (MLP topology has been developed to account wax appearance temperature and the amount of precipitated wax and the model was verified using experimental data given in this work and reported in the literature. In order to compare the performance of the proposed model based on Artificial Neural Network, the wax precipitation experimental data at different temperatures were predicted using solid solution model and multi-solid phase model. The results showed that the developed model based on Artificial Neural Network can predict more accurately the wax precipitation experimental data in comparison to the previous models such as solid solution and multi-solid phase model with AADs less than 0.5%. Furthermore, the number of parameters required for the Artificial Neural Network (ANN model is less than the studied thermodynamic models.

Comparison of six different models describing survival of mammalian cells after irradiation

International Nuclear Information System (INIS)

Sontag, W.

1990-01-01

Six different cell-survival models have been compared. All models are based on the similar assumption that irradiated cells are able to exist in one of three states. S A is the state of a totally repaired cell, in state S C the cell contains lethal lesions and in state S b the cell contains potentially lethal lesions i.e. those which either can be repaired or converted into lethal lesions. The differences between the six models lie in the different mathematical relationships between the three states. To test the six models, six different sets of experimental data were used which describe cell survival at different repair times after irradiation with sparsely ionizing irradiation. In order to compare the models, a goodness-of-fit function was used. The differences between the six models were tested by use of the nonparametric Mann-Whitney two sample test. Based on the 95% confidence limit, this required separation into three groups. (orig.)

Search procedure for models based on the evolution of experimental curves

International Nuclear Information System (INIS)

Delforge, J.

1975-01-01

The possibilities offered by numerical analysis regarding the identification of parameters for the model are outlined. The use of a large number of experimental measurements is made possible by the flexibility of the proposed method. It is shown that the errors of numerical identification over all parameters are proportional to experimental errors, and to a proportionality factor called conditioning of the identification problem which is easily computed. Moreover, it is possible to define and calculate, for each parameter, a factor of sensitivity to experimental errors. The numerical values of conditioning and sensitivity factor depend on all experimental conditions, that is, on the one hand, the specific definition of the experiments, and on the other hand, the number and quality of the undertaken measurements. The identification procedure proposed includes several phases. The preliminary phase consists in a first definition of experimental conditions, in agreement with the experimenter. From the data thus obtained, it is generally possible to evaluate the minimum number of equivalence classes required for an interpretation compatible with the morphology of experimental curves. Possibly, from this point, some additional measurements may prove useful or required. The numerical phase comes afterwards to determine a first approximate model by means of the methods previously described. Next phases again require a close collaboration between experimenters and theoreticians. They consist mainly in refining the first model [fr

Application of the Physical Disector Principle for Quantification of Dopaminergic Neuronal Loss in a Rat 6-Hydroxydopamine Nigral Lesion Model of Parkinson's Disease

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Katrine Fabricius

2017-12-01

Full Text Available Stereological analysis is the optimal tool for quantitative assessment of brain morphological and cellular changes induced by neurotoxic lesions or treatment interventions. Stereological methods based on random sampling techniques yield unbiased estimates of particle counts within a defined volume, thereby providing a true quantitative estimate of the target cell population. Neurodegenerative diseases involve loss of specific neuron types, such as the midbrain tyrosine hydroxylase-positive dopamine neurons in Parkinson's disease and in animal models of nigrostriatal degeneration. Therefore, we applied an established automated physical disector principle in a fractionator design for efficient stereological quantitative analysis of tyrosine hydroxylase (TH-positive dopamine neurons in the substantia nigra pars compacta of hemiparkinsonian rats with unilateral 6-hydroxydopamine (6-OHDA lesions. We obtained reliable estimates of dopamine neuron numbers, and established the relationship between behavioral asymmetry and dopamine neuron loss on the lesioned side. In conclusion, the automated physical disector principle provided a useful and efficient tool for unbiased estimation of TH-positive neurons in rat midbrain, and should prove valuable for investigating neuroprotective strategies in 6-OHDA model of parkinsonism, while generalizing to other immunohistochemically-defined cell populations.

Experimental, statistical, and biological models of radon carcinogenesis

International Nuclear Information System (INIS)

Cross, F.T.

1991-09-01

Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared to domestic environments and from uncertainties about the interaction between cigarette-smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research program that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models), and the relationship of radon to smoking and other copollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. 20 refs., 1 fig

Evaluation of agents to detect inflammatory foci using an experimental animal model

International Nuclear Information System (INIS)

Shimpi, H.H.; Noronha, O.P.D.; Samuel, A.M.

1997-01-01

We have evaluated the propensities of four agents- two metal complexes and two protein species, viz. 67 Ga-citrate, 99m Tc-citrate, 99m Tc-human immunoglobulin ( 99m Tc-HIG); and 99m Tc-human serum albumin ( 99m Tc-HSA), for localization of (turpentine- induced) inflammatory lesions in a rat and rabbit animal model systems. All these radiopharmaceuticals showed fairly good uptake in inflammatory lesions. 99m Tc-HIG, 99m Tc-HSA and 67 Ga-citrate showed slower blood clearance and higher liver uptakes. On the other hand 99m Tc-citrate demonstrated faster blood clearance and negligible liver and gut accumulation. The respective inflamed/normal muscle (IM/NM) ratios obtained with these agents in this animal model were in the following order: 99m Tc-HIG> 99m Tc-HSA> 67 Ga-citrate> 99m Tc-citrate at 5 h post injection. Although the IM/NM was relatively low in the case of 99m Tc-citrate as compared with other radiopharmaceuticals the inflammation could be detected within 1-3 h. post injection because of the higher activities that could be injected with this radiopharmaceutical. Since 99m Tc-citrate is predominantly excreted via renal pathway it is rapidly cleared from blood and shows fairly good accumulation in infection/inflammatory lesions at early time periods along with low uptakes in liver and adjacent organs. This agent can therefore be beneficially used to detect the abdominal abscess(es)/inflammation(s) within 1-3 h post injection. Because of its favourable characteristics, physical, biological, clinical, and even cost-effectiveness, it is suggested that 99m Tc-citrate could be tried out as an agent for detection of inflammation including abdominal and vertebral abscess(es). (author)

Concordance between fine-needle aspiration and core biopsies for osseous lesions by lesion imaging appearance and CT attenuation.

Science.gov (United States)

Li, John; Weissberg, Zoe; Bevilacqua, Thomas A; Yu, Gordon; Weber, Kristy; Sebro, Ronnie

2018-04-01

To compare the concordance between fine-needle aspiration and core biopsies for osseous lesions by lesion imaging appearance and CT attenuation. Retrospective review of 215 FNAs of osseous lesions performed in conjunction with core biopsy at our institution over a 6-year period (2011-2016). FNAs were interpreted independently of core biopsies. We assessed if FNA in conjunction with core biopsy increased diagnostic accuracy compared to core biopsy alone. We also calculated the concordance between FNA and core biopsy by lesion appearance, lesion CT attenuation, lesion histology, lesion location and FNA needle gauge size. Core biopsy alone provided the diagnosis in 207/215 cases (96.3%), however, the FNA provided the diagnosis in the remaining 8/215 cases (3.7%) where the core biopsy was non-diagnostic. There were 154 (71.6%) lytic lesions, 21 (9.8%) blastic lesions, 25 (11.6%) mixed lytic and blastic lesions and 15 (7.0%) lesions that were neither lytic nor blastic. The concordance between FNA and core biopsy for lytic osseous lesions (136/154 cases, 88.3%) was statistically significantly higher than that for blastic osseous lesions (13/21 cases, 61.9%) [P = 4.2 × 10 -3 ; 95% CI (0.02, 0.50)]. The concordance between FNA and core biopsy was higher for low-attenuation- (110/126) than high-attenuation (58/77) lesions (P = 0.028). The concordance between FNA and core biopsy was also higher for metastases (102/119 cases, 85.7%) than non-metastases (78/96, 81.3%) [P = 0.487; 95% CI (- 0.15, 0.065)]. There was no difference in the rate of concordance between FNA and core biopsy by lesion location or FNA needle gauge size (P > 0.05). FNA with core biopsy increases diagnostic rate compared to core biopsy alone or FNA alone. The concordance between FNA and core biopsy is higher for lytic lesions than for blastic lesions; and higher for low-attenuation lesions than for high-attenuation lesions.

Epidermal hydrogen peroxide is not increased in lesional and non-lesional skin of vitiligo.

Science.gov (United States)

Zailaie, Mohammad Z

2017-01-01

It is widely believed that the loss of the epidermal melanocytes in vitiligo is basically due to excessive oxidative stress. Previous research work described abnormal elevation of the absolute concentration of the epidermal hydrogen peroxide (H 2 O 2 ) in lesional and non-lesional skin of vitiligo. Based on this finding, our primary research objective was to use this feature as a screening marker in individuals at a great risk of developing vitiligo. Ninety-six patients of non-segmental vitiligo (NSV) of varying durations, skin phototypes, and treatment modalities (psoralen UVA-, narrow band UVB-treated) were recruited for this study. Raman spectroscopic measurements, using an external probehead, of the lesional and non-lesional skin were obtained, and the resulting spectra were analyzed using the Opus software package of the MultiRam spectrometer and the intensity of the peak at 875 cm -1 that represents the absolute concentration of H 2 O 2 was calculated. Contrary to previous reports, in patients of skin phototype IV, the absolute concentrations of H 2 O 2 in non-lesional and lesional NSV of all groups were non-significantly decreased compared to normal control. In patients of NSV of skin phototype V, the decrease in the absolute concentrations of H 2 O 2 was not significant in the untreated group, and a slight non-significant increase in the NBUVB-treated group was noted. However, in the PUVA-treated group, the non-lesional skin demonstrated significant increase in the absolute concentration of H 2 O 2 , whereas the lesional skin showed only a slight non-significant increase compared to normal control. In NSV patients of skin phototype VI who were previously treated with PUVA, the non-lesional skin showed a slight non-significant increase in the absolute concentration of H 2 O 2 ; however, the lesional skin showed a marked significant decrease compared to normal control and the non-lesional skin. Thereof, one can conclude that the epidermal H 2 O 2 is not

The effects of iterative reconstruction in CT on low-contrast liver lesion volumetry: a phantom study

Science.gov (United States)

Li, Qin; Berman, Benjamin P.; Schumacher, Justin; Liang, Yongguang; Gavrielides, Marios A.; Yang, Hao; Zhao, Binsheng; Petrick, Nicholas

2017-03-01

Tumor volume measured from computed tomography images is considered a biomarker for disease progression or treatment response. The estimation of the tumor volume depends on the imaging system parameters selected, as well as lesion characteristics. In this study, we examined how different image reconstruction methods affect the measurement of lesions in an anthropomorphic liver phantom with a non-uniform background. Iterative statistics-based and model-based reconstructions, as well as filtered back-projection, were evaluated and compared in this study. Statistics-based and filtered back-projection yielded similar estimation performance, while model-based yielded higher precision but lower accuracy in the case of small lesions. Iterative reconstructions exhibited higher signal-to-noise ratio but slightly lower contrast of the lesion relative to the background. A better understanding of lesion volumetry performance as a function of acquisition parameters and lesion characteristics can lead to its incorporation as a routine sizing tool.

Embryonic Cell Grafts in a Culture Model of Spinal Cord Lesion: Neuronal Relay Formation is Essential for Functional Regeneration

Directory of Open Access Journals (Sweden)

Anne Tscherter

2016-09-01

Full Text Available Presently there exists no cure for spinal cord injury. However, transplantation of embryonic tissue into spinal cord lesions resulted in axon outgrowth across the lesion site and some functional recovery, fostering hope for future stem cell therapies. Although in vivo evidence for functional recovery is given, the exact cellular mechanism of the graft support remains elusive: either the grafted cells provide a permissive environment for the host tissue to regenerate itself or the grafts actually integrate functionally into the host neuronal network reconnecting the separated spinal cord circuits. We tested the two hypotheses in an in vitro spinal cord lesion model that is based on propagation of activity between two rat organotypic spinal cord slices in culture. Transplantation of dissociated cells from E14 rat spinal cord or forebrain re-established the relay of activity over the lesion site and, thus, provoked functional regeneration. Combining patch-clamp recordings from transplanted cells with network activity measurements from the host tissue on multi-electrode arrays we here show that neurons differentiate from the grafted cells and integrate into the host circuits. Optogenetic silencing of neurons developed from transplanted embryonic mouse forebrain cells provides clear evidence that they replace the lost neuronal connections to relay and synchronize activity between the separated spinal cord circuits. In contrast, transplantation of neurospheres induced neither the differentiation of mature neurons from the grafts nor an improvement of functional regeneration. Together these findings suggest, that the formation of neuronal relays from grafted embryonic cells is essential to re-connect segregated spinal cord circuits.

Differentiation of benign and malignant lung lesions: Dual-Energy Computed Tomography findings

Energy Technology Data Exchange (ETDEWEB)

González-Pérez, Víctor [Dept Radiophysics, Foundation IVO, Valencia (Spain); Arana, Estanislao, E-mail: aranae@uv.es [Dept Radiology, Foundation IVO, Valencia (Spain); Barrios, María [Dept Radiology, Foundation IVO, Valencia (Spain); Bartrés, Albert [Dept Radiophysics, Foundation IVO, Valencia (Spain); Cruz, Julia [Dept Pathology, Foundation IVO, Valencia (Spain); Montero, Rafael [GE Healthcare Diagnostic Imaging, Iberia (Spain); González, Manuel; Deltoro, Carlos [Dept Radiology, Foundation IVO, Valencia (Spain); Martínez-Pérez, Encarnación [Dept Pneumology, Foundation IVO, Valencia (Spain); De Aguiar-Quevedo, Karol; Arrarás, Miguel [Dept Thoracic Surgery, Foundation IVO, Valencia (Spain)

2016-10-15

Purpose: To determine whether parameters generated by Dual-Energy Computed Tomography (DECT) can distinguish malignant from benign lung lesions. Methods: A prospective review of 125 patients with 126 lung lesions (23 benign and 103 malignant) who underwent lung DECT during arterial phase. All lesions were confirmed by tissue sampling. A radiologist semi-automatically contoured lesions and placed regions of interest (ROIs) in paravertebral muscle (PVM) for normalization. Variables related to absorption in Hounsfield units (HU), effective atomic number (Z{sub eff}), iodine concentration (ρ{sub I}) and spectral CT curves were assessed. Receiver operating characteristic (ROC) curves were generated to calculate sensitivity and specificity as predictors of malignancy. Multivariate logistic regression analysis was performed. Results: Reproducibility of measures normalized with PVM was poor. Bivariate analysis showed minimum Z{sub eff} and normalized mean Z{sub eff} to be statistically significant (p = 0.001), with area under the curve (AUC) values: 0.66 (CI 95% 0.54–0.80) and 0.72 (CI 95%, 0.60–0.84), respectively. Logistic regression models showed no differences between raw and normalized measurements. In both models, minimum HU (OR: 0.9) and size (OR: 0.1) were predictive of benign lesions. Conclusions: A quantitative approach to DECT using raw measurements is simpler than logistic regression models. Normalization to PVM was not clinically reliable due to its poor reproducibility. Further studies are needed to confirm our findings.

Ultraviolet radiation-induced carcinogenesis: mechanisms and experimental models

International Nuclear Information System (INIS)

Ramasamy, Karthikeyan; Shanmugam, Mohana; Balupillai, Agilan; Govindhasamy, Kanimozhi; Gunaseelan, Srithar; Muthusamy, Ganesan; Robert, Beualah Mary; Nagarajan, Rajendra Prasad

2017-01-01

Ultraviolet radiation (UVR) is a very prominent environmental toxic agent. UVR has been implicated in the initiation and progression of photocarcinogenesis. UVR exposure elicits numerous cellular and molecular events which include the generation of inflammatory mediators, DNA damage, epigenetic modifications, and oxidative damages mediated activation of signaling pathways. UVR-initiated signal transduction pathways are believed to be responsible for tumor promotion effects. UVR-induced carcinogenic mechanism has been well studied using various animal and cellular models. Human skin-derived dermal fibroblasts, epidermal keratinocytes, and melanocytes served as excellent cellular model systems for the understanding of UVR-mediated carcinogenic events. Apart from this, scientists developed reconstituted three-dimensional normal human skin equivalent models for the study of UVR signaling pathways. Moreover, hairless mice such as SKH-1, devoid of Hr gene, served as a valuable model for experimental carcinogenesis. Scientists have also used transgenic mice and dorsal portion shaved Swiss albino mice for UVR carcinogenesis studies. In this review, we have discussed the current progress in the study on ultraviolet B (UVB)-mediated carcinogenesis and outlined appropriate experimental models for both ultraviolet A- and UVB-mediated carcinogenesis. (author)

Comparison between a Computational Seated Human Model and Experimental Verification Data

Directory of Open Access Journals (Sweden)

Christian G. Olesen

2014-01-01

Full Text Available Sitting-acquired deep tissue injuries (SADTI are the most serious type of pressure ulcers. In order to investigate the aetiology of SADTI a new approach is under development: a musculo-skeletal model which can predict forces between the chair and the human body at different seated postures. This study focuses on comparing results from a model developed in the AnyBody Modeling System, with data collected from an experimental setup. A chair with force-measuring equipment was developed, an experiment was conducted with three subjects, and the experimental results were compared with the predictions of the computational model. The results show that the model predicted the reaction forces for different chair postures well. The correlation coefficients of how well the experiment and model correlate for the seat angle, backrest angle and footrest height was 0.93, 0.96, and 0.95. The study show a good agreement between experimental data and model prediction of forces between a human body and a chair. The model can in the future be used in designing wheelchairs or automotive seats.

Modelling and experimental studies on a mixed-mode natural convection solar crop-dryer

Energy Technology Data Exchange (ETDEWEB)

Forson, F.K. [Department of Mechanical Engineering, Kwame Nkrumah University of Science and Technology, Kumasi (Ghana); Nazha, M.A.A.; Rajakaruna, H. [School of Engineering and Technology, De Montfort University, Queens Building, Leicester LE1 9BH (United Kingdom)

2007-03-15

A mathematical model for drying agricultural products in a mixed-mode natural convection solar crop dryer (MNCSCD) using a single-pass double-duct solar air-heater (SPDDSAH) is presented. The model was developed in parallel with experimental work. The model comprises the air-heating process model, the drying model and the technical performance criteria model. The governing equations of the drying air temperature and humidity ratio; the material temperature and its moisture content; and performance criteria indicators are derived. The model requires the solution of a number of interrelated non-linear equations and a set of simultaneous differential equations. Results from experimental studies used for generating the required experimental data for validating the model are presented. Results of simulation runs using the model are presented and compared with the experimental data. It is shown that the model can predict the performance of the MNCSCD fairly accurately and therefore can be used as a design tool for prototype development. (author)

Upregulated expression of Nogo-A and NgR in an experimental model of focal microgyria regulates the migration, proliferation and self-renewal of subventricular zone neural progenitors

Energy Technology Data Exchange (ETDEWEB)

Yu, Sixun; Shu, Haifeng; Yang, Tao; Huang, Haidong [Department of Neurosurgery, General Hospital of the People' s Liberation Army Chengdu Military Region, Chengdu, Sichuan, 610083 (China); Li, Song [Department of Neurosurgery, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037 (China); Zhao, Ziyi [Central Laboratory, Teaching Hospital of Chengdu University of Traditional Chinese Medicine, 610075 (China); Kuang, Yongqin, E-mail: kuangyongqin@163.com [Department of Neurosurgery, General Hospital of the People' s Liberation Army Chengdu Military Region, Chengdu, Sichuan, 610083 (China)

2016-04-29

Nogo-A and its receptor (NgR) were first described as myelin-associated inhibitors of neuronal regeneration in response to injury. In recent years, knowledge about the important role of the Nogo-A protein in several neuronal pathologies has grown considerably. Here, we employed a neonatal cortex freeze-lesion (NFL) model in neonatal rats and measured the expression of Nogo-A and NgR in the resulting cerebrocortical microdysgenesis 5–75 days after freezing injury. We observed marked upregulation of Nogo-A and NgR in protein levels. Furthermore, the migration of neural precursor cells (NPCs) derived from the subventricular zone (SVZ) toward the sits of injury was perturbed by treatment of NgR antagonist peptide NEP1-40. In vitro analysis showed that the knockdown of NgR by lentivirus-delivered siRNA promoted in axonal regeneration and SVZ-derived neural stem cell/progenitor cell (SVZ-NPCs) adhesion and migration, findings which were similar to the effects of NEP1-40. Taken together, our results indicate an important role for NgR in regulating the physiological processes of SVZ-NPCs. The observation of upregulated Nogo-A/NgR in lesion sites in the NFL model suggest that the effects of the perturbed Nogo-A are a key feature during the development and/or the progression of cortical malformation. - Highlights: • NFL model is an accurate experimental reproduction of focal microgyria of FCD. • The increase of the Nogo-A Levels occurs in response to freeze-induced focal lesioning. • Nogo-A/NgR may play a critical role for in the pathologic progression of FCD. • Nogo-A is associated with the migration, proliferation and self-renewal of SVZ-NPCs.

Effects of (-)-sesamin on motor and memory deficits in an MPTP-lesioned mouse model of Parkinson's disease treated with l-DOPA.

Science.gov (United States)

Zhao, T T; Shin, K S; Kim, K S; Park, H J; Kim, H J; Lee, K E; Lee, M K

2016-12-17

The present study investigated the effects of (-)-sesamin on motor and memory deficits in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned mouse model of Parkinson's disease (PD) with l-3,4-dihydroxyphenylalanine (l-DOPA). MPTP-lesioned (30mg/kg/day, 5days) mice showed deficits in memory including habit learning memory and spatial memory, which were further aggravated by daily treatment with 25mg/kg l-DOPA for 21days. However, daily treatment with (-)-sesamin (25 and 50mg/kg) for 21days ameliorated memory deficits in an MPTP-lesioned mouse model of PD treated with l-DOPA (25mg/kg). Both (-)-sesamin doses reduced decreases in the retention latency time in the passive avoidance test, latency to fall of rotarod test and distance traveled in the open field test, and attenuated decreases in tyrosine hydroxylase (TH)-immunopositive cells, dopamine, and its metabolites in the substantia nigra-striatum. (-)-Sesamin reduced increases in the retention transfer latency time in the elevated plus-maze test and N-methyl-d-aspartate receptor (NMDAR) expression and reduced decreases in the phosphorylation of extracellular signal-regulated kinase (ERK1/2) and cyclic AMP-response element binding protein (CREB) in the hippocampus. In contrast, daily treatment with 10mg/kg l-DOPA for 21days ameliorated memory deficits in MPTP-lesioned mice, and this effect was further improved by treatment with (-)-sesamin (25 and 50mg/kg). These results suggest that (-)-sesamin protects against habit learning memory deficits by activating the dopamine neuronal system, while spatial memory deficits are decreased by its modulatory effects on the NMDAR-ERK1/2-CREB system. Accordingly, (-)-sesamin may act as an adjuvant phytonutrient for motor and memory deficits in patients with PD receiving l-DOPA. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Does the cerebral cortex exacerbate dopaminergic cell death in the substantia nigra of 6OHDA-lesioned rats?

Science.gov (United States)

Luquin, Natasha; Mitrofanis, John

2008-01-01

We have explored the survival of dopaminergic cells of the substantia nigra pars compacta (SNc) in 6 hydroxydopamine (6OHDA)-lesioned rats with prior cortical removal. There were approximately 35% more dopaminergic cells in the ventral sector of SNc (vSNc) of 6OHDA-lesioned rats that had prior cortical removal compared to those that did not. By contrast, there were no differences in dopaminergic cell number between these experimental groups in the ventral tegmental area (VTA) and the dorsal sector of SNc (dSNc). Hence, prior cortical removal in 6OHDA-lesioned rats neuroprotected vSNc--but not VTA or dSNc--dopaminergic cells from death.

Improved efficiency in clinical workflow of reporting measured oncology lesions via PACS-integrated lesion tracking tool.

Science.gov (United States)

Sevenster, Merlijn; Travis, Adam R; Ganesh, Rajiv K; Liu, Peng; Kose, Ursula; Peters, Joost; Chang, Paul J

2015-03-01

OBJECTIVE. Imaging provides evidence for the response to oncology treatment by the serial measurement of reference lesions. Unfortunately, the identification, comparison, measurement, and documentation of several reference lesions can be an inefficient process. We tested the hypothesis that optimized workflow orchestration and tight integration of a lesion tracking tool into the PACS and speech recognition system can result in improvements in oncologic lesion measurement efficiency. SUBJECTS AND METHODS. A lesion management tool tightly integrated into the PACS workflow was developed. We evaluated the effect of the use of the tool on measurement reporting time by means of a prospective time-motion study on 86 body CT examinations with 241 measureable oncologic lesions with four radiologists. RESULTS. Aggregated measurement reporting time per lesion was 11.64 seconds in standard workflow, 16.67 seconds if readers had to register measurements de novo, and 6.36 seconds for each subsequent follow-up study. Differences were statistically significant (p workflow-integrated lesion management tool, especially for patients with multiple follow-up examinations, reversing the onetime efficiency penalty at baseline registration.

Using an experimental model for the study of therapeutic touch.

Science.gov (United States)

dos Santos, Daniella Soares; Marta, Ilda Estéfani Ribeiro; Cárnio, Evelin Capellari; de Quadros, Andreza Urba; Cunha, Thiago Mattar; de Carvalho, Emilia Campos

2013-02-01

to verify whether the Paw Edema Model can be used in investigations about the effects of Therapeutic Touch on inflammation by measuring the variables pain, edema and neutrophil migration. this is a pilot and experimental study, involving ten male mice of the same genetic strain and divided into experimental and control group, submitted to the chemical induction of local inflammation in the right back paw. The experimental group received a daily administration of Therapeutic Touch for 15 minutes during three days. the data showed statistically significant differences in the nociceptive threshold and in the paw circumference of the animals from the experimental group on the second day of the experiment. the experiment model involving animals can contribute to study the effects of Therapeutic Touch on inflammation, and adjustments are suggested in the treatment duration, number of sessions and experiment duration.

Prevalencia de lesiones incipientes de caries dental en niños escolares Prevalence of incipient lesions of dental caries in school children

Directory of Open Access Journals (Sweden)

Nayda Nasco Hidalgo

2008-06-01

School in Plaza de la Revolución municipality from January to December 2006, and to identify in the studied group the frequency of children according to the number of incipient lesion, as well as the frequency of incipient lesions per tooth localization in the arcade and per dental surface. METHODS: an observational descriptive cross-sectional study was undertaken. The universe consisted of all the children aged 6-11 that fulfilled the inclusion criteria for a total of 236, who were examined in the open-air and with natural light by using the soft visual-tactile method. The teeth were cleaned with cotton and were dried with air to detect the presence of incipient carious lesions, which were indicated in a dentigram model in the place corresponding to the surface affected. RESULTS: it was found that 22.5 % of the school children examined presented these lesions. Of them, 60.1 % were females, 19.5 % of the total of children presented a lesion and just 3 % had 2 incipient lesions of dental caries; 79.2 % of them were observed in the posterior tooth. The smooth surfaces were the most affected with 45.3 %. CONCLUSIONS: Approximately the fourth part of the studied children presented incipient carious lesions. Females were the most affected. Of all the children with incipient lesions, the highest figure corresponded to those having a lesion. The posterior teeth were the most affected by incipient lesions. The smooth surfaces showed more incipient lesions than the occlusal and proximal

Experimental study and mathematical model on remediation of Cd spiked kaolinite by electrokinetics

International Nuclear Information System (INIS)

Mascia, Michele; Palmas, Simonetta; Polcaro, Anna Maria; Vacca, Annalisa; Muntoni, Aldo

2007-01-01

An experimental study on electrokinetic removal of cadmium from kaolinitic clays is presented in this work, which is aimed to investigate the effect of surface reactions on the electrokinetic process. Enhanced electrokinetic tests were performed in which the pH of the compartments was controlled. Cadmium spiked kaolin was adopted in the experimental runs. On the basis of the experimental results, a numerical model was formulated to simulate the cadmium (Cd) transport under an electric field by combining a one-dimensional diffusion-advection model with a geochemical model: the combined model describes the contaminant transport driven by chemical and electrical gradients, as well as the effect of the surface reactions. The geochemical model utilized parameters derived from the literature, and it was validated by experimental data obtained by sorption and titration experiments. Electrokinetic tests were utilized to validate the results of the proposed model. A good prediction of the behaviour of the soil/cadmium ions system under electrical field was obtained: the differences between experimental and model predicted profiles for the species considered were less than 5% in all the examined conditions

A disappearing neonatal skin lesion.

LENUS (Irish Health Repository)

Hawkes, Colin Patrick

2012-01-31

A preterm baby girl was noted at birth to have a firm, raised, non-tender skin lesion located over her right hip. She developed three similar smaller lesions on her ear, buttock and right knee. All lesions had resolved by 2 months of age.

X-ray stereotactic lesion localization in conjunction with dedicated scintimammography

Energy Technology Data Exchange (ETDEWEB)

Mitali J. More; Deepa Narayanan; Patricia J. Goodale; Stanislaw Majewski; Benjamin Welch; Randolph Wojcik; Mark Williams

2003-10-01

We are developing a dual modality system that combines digital X-ray mammography with gamma emission scintigraphy on an upright mammography gantry. The breast is held under mild compression by a support structure that is independent of the detectors. The X-ray source and detectors can be rotated around a fixed rotation axis permitting multiple views of the breast with fixed compression. Two such views can be combined as a stereotactic pair to obtain the three-dimensional location of breast lesions. Information about the location of the lesion within the breast permits corrections for attenuation and detector spatial resolution, resulting in more accurate estimation of the true lesion-to-background concentration ratio, based on the image lesion-to-background counts ratio. In this paper, we describe the model used to make these corrections, and present the results of the phantom experiments designed to test the accuracy of our calculations.

Diffuse cavitary lung lesions

Energy Technology Data Exchange (ETDEWEB)

Grunzke, Mindy; Garrington, Timothy [University of Colorado Denver, Department of Pediatrics, Aurora, CO (United States); The Children' s Hospital, Rick Wilson Center for Cancer and Blood Disorders, Aurora, CO (United States); Hayes, Kari [The Children' s Hospital, Pediatric Radiology, Aurora, CO (United States); Bourland, Wendy [Children' s Hospital at St. Francis, Warren Clinic, Inc., Tulsa, OK (United States)

2010-02-15

An 11-year-old girl presented with a 2-month history of progressively worsening cough, daily fevers, and weight loss. A chest radiograph revealed multiple cystic cavitary lung lesions. An extensive infectious work-up was negative. Chest CT verified multiple cavitary lung lesions bilaterally, and [F-18]2-fluoro-2-deoxy-D-glucose ({sup 18}F-FDG) positron emission tomography with CT (PET/CT) showed increased uptake in the lung lesions as well as regional lymph nodes. Subsequent biopsy of an involved lymph node confirmed classical Hodgkin lymphoma, nodular sclerosis type. This case represents an unusual presentation for a child with Hodgkin lymphoma and demonstrates a role for {sup 18}F-FDG PET/CT in evaluating a child with cavitary lung lesions. (orig.)

Diffuse cavitary lung lesions

International Nuclear Information System (INIS)

Grunzke, Mindy; Garrington, Timothy; Hayes, Kari; Bourland, Wendy

2010-01-01

An 11-year-old girl presented with a 2-month history of progressively worsening cough, daily fevers, and weight loss. A chest radiograph revealed multiple cystic cavitary lung lesions. An extensive infectious work-up was negative. Chest CT verified multiple cavitary lung lesions bilaterally, and [F-18]2-fluoro-2-deoxy-D-glucose ( 18 F-FDG) positron emission tomography with CT (PET/CT) showed increased uptake in the lung lesions as well as regional lymph nodes. Subsequent biopsy of an involved lymph node confirmed classical Hodgkin lymphoma, nodular sclerosis type. This case represents an unusual presentation for a child with Hodgkin lymphoma and demonstrates a role for 18 F-FDG PET/CT in evaluating a child with cavitary lung lesions. (orig.)

Experimental model of intervertebral disc degeneration by needle puncture in Wistar rats

International Nuclear Information System (INIS)

Issy, A.C.; Castania, V.; Castania, M.; Salmon, C.E.G.; Nogueira-Barbosa, M.H.; Bel, E. Del; Defino, H.L.A.

2013-01-01

Animal models of intervertebral disc degeneration play an important role in clarifying the physiopathological mechanisms and testing novel therapeutic strategies. The objective of the present study is to describe a simple animal model of disc degeneration involving Wistar rats to be used for research studies. Disc degeneration was confirmed and classified by radiography, magnetic resonance and histological evaluation. Adult male Wistar rats were anesthetized and submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7 and 8-9 of the coccygeal vertebrae. The needle was inserted into the discs guided by fluoroscopy and its tip was positioned crossing the nucleus pulposus up to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s. To grade the severity of intervertebral disc degeneration, we measured the intervertebral disc height from radiographic images 7 and 30 days after the injury, and the signal intensity T2-weighted magnetic resonance imaging. Histological analysis was performed with hematoxylin-eosin and collagen fiber orientation using picrosirius red staining and polarized light microscopy. Imaging and histological score analyses revealed significant disc degeneration both 7 and 30 days after the lesion, without deaths or systemic complications. Interobserver histological evaluation showed significant agreement. There was a significant positive correlation between histological score and intervertebral disc height 7 and 30 days after the lesion. We conclude that the tail disc puncture method using Wistar rats is a simple, cost-effective and reproducible model for inducing disc degeneration

Experimental model of intervertebral disc degeneration by needle puncture in Wistar rats

Energy Technology Data Exchange (ETDEWEB)

Issy, A.C.; Castania, V.; Castania, M. [Departamento de Morfologia, Fisiologia e Patologia Básica, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Salmon, C.E.G. [Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Nogueira-Barbosa, M.H. [Divisão de Radiologia, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Bel, E. Del [Departamento de Morfologia, Fisiologia e Patologia Básica, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Defino, H.L.A. [Departamento de Biomecânica, Medicina e Reabilitação do Sistema Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

2013-03-15

Animal models of intervertebral disc degeneration play an important role in clarifying the physiopathological mechanisms and testing novel therapeutic strategies. The objective of the present study is to describe a simple animal model of disc degeneration involving Wistar rats to be used for research studies. Disc degeneration was confirmed and classified by radiography, magnetic resonance and histological evaluation. Adult male Wistar rats were anesthetized and submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7 and 8-9 of the coccygeal vertebrae. The needle was inserted into the discs guided by fluoroscopy and its tip was positioned crossing the nucleus pulposus up to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s. To grade the severity of intervertebral disc degeneration, we measured the intervertebral disc height from radiographic images 7 and 30 days after the injury, and the signal intensity T2-weighted magnetic resonance imaging. Histological analysis was performed with hematoxylin-eosin and collagen fiber orientation using picrosirius red staining and polarized light microscopy. Imaging and histological score analyses revealed significant disc degeneration both 7 and 30 days after the lesion, without deaths or systemic complications. Interobserver histological evaluation showed significant agreement. There was a significant positive correlation between histological score and intervertebral disc height 7 and 30 days after the lesion. We conclude that the tail disc puncture method using Wistar rats is a simple, cost-effective and reproducible model for inducing disc degeneration.

Optimality models in the age of experimental evolution and genomics.

Science.gov (United States)

Bull, J J; Wang, I-N

2010-09-01

Optimality models have been used to predict evolution of many properties of organisms. They typically neglect genetic details, whether by necessity or design. This omission is a common source of criticism, and although this limitation of optimality is widely acknowledged, it has mostly been defended rather than evaluated for its impact. Experimental adaptation of model organisms provides a new arena for testing optimality models and for simultaneously integrating genetics. First, an experimental context with a well-researched organism allows dissection of the evolutionary process to identify causes of model failure--whether the model is wrong about genetics or selection. Second, optimality models provide a meaningful context for the process and mechanics of evolution, and thus may be used to elicit realistic genetic bases of adaptation--an especially useful augmentation to well-researched genetic systems. A few studies of microbes have begun to pioneer this new direction. Incompatibility between the assumed and actual genetics has been demonstrated to be the cause of model failure in some cases. More interestingly, evolution at the phenotypic level has sometimes matched prediction even though the adaptive mutations defy mechanisms established by decades of classic genetic studies. Integration of experimental evolutionary tests with genetics heralds a new wave for optimality models and their extensions that does not merely emphasize the forces driving evolution.

Experimental nitrogen dioxide poisoning in cattle

Energy Technology Data Exchange (ETDEWEB)

Cutlip, R C

1966-01-01

Experimental nitrogen dioxide inhalation has been reported to produce signs and lesions typical of field cases of bovine pulmonary adenomatosis (BPA) as described by Monlux et al, and Seaton. Similar lesions have been produced in mice and guinea pigs. These studies were conducted because of the similarities between silo-filler's disease of man, caused by nitrogen dioxide, and BPA. Since previous studies involved inadequate numbers of cattle, a more critical evaluation of the effects of nitrogen dioxide was needed. This project was designed to study the clinical and pathologic alterations induced in cattle by repeated exposure to nitrogen dioxide gas.

A Dirichlet process mixture model for automatic {sup 18}F-FDG PET image segmentation: Validation study on phantoms and on lung and esophageal lesions

Energy Technology Data Exchange (ETDEWEB)

Giri, Maria Grazia, E-mail: mariagrazia.giri@ospedaleuniverona.it; Cavedon, Carlo [Medical Physics Unit, University Hospital of Verona, P.le Stefani 1, Verona 37126 (Italy); Mazzarotto, Renzo [Radiation Oncology Unit, University Hospital of Verona, P.le Stefani 1, Verona 37126 (Italy); Ferdeghini, Marco [Nuclear Medicine Unit, University Hospital of Verona, P.le Stefani 1, Verona 37126 (Italy)

2016-05-15

Purpose: The aim of this study was to implement a Dirichlet process mixture (DPM) model for automatic tumor edge identification on {sup 18}F-fluorodeoxyglucose positron emission tomography ({sup 18}F-FDG PET) images by optimizing the parameters on which the algorithm depends, to validate it experimentally, and to test its robustness. Methods: The DPM model belongs to the class of the Bayesian nonparametric models and uses the Dirichlet process prior for flexible nonparametric mixture modeling, without any preliminary choice of the number of mixture components. The DPM algorithm implemented in the statistical software package R was used in this work. The contouring accuracy was evaluated on several image data sets: on an IEC phantom (spherical inserts with diameter in the range 10–37 mm) acquired by a Philips Gemini Big Bore PET-CT scanner, using 9 different target-to-background ratios (TBRs) from 2.5 to 70; on a digital phantom simulating spherical/uniform lesions and tumors, irregular in shape and activity; and on 20 clinical cases (10 lung and 10 esophageal cancer patients). The influence of the DPM parameters on contour generation was studied in two steps. In the first one, only the IEC spheres having diameters of 22 and 37 mm and a sphere of the digital phantom (41.6 mm diameter) were studied by varying the main parameters until the diameter of the spheres was obtained within 0.2% of the true value. In the second step, the results obtained for this training set were applied to the entire data set to determine DPM based volumes of all available lesions. These volumes were compared to those obtained by applying already known algorithms (Gaussian mixture model and gradient-based) and to true values, when available. Results: Only one parameter was found able to significantly influence segmentation accuracy (ANOVA test). This parameter was linearly connected to the uptake variance of the tested region of interest (ROI). In the first step of the study, a

Irradiation Design for an Experimental Murine Model

International Nuclear Information System (INIS)

Ballesteros-Zebadua, P.; Moreno-Jimenez, S.; Suarez-Campos, J. E.; Celis, M. A.; Larraga-Gutierrez, J. M.; Garcia-Garduno, O. A.; Rubio-Osornio, M. C.; Custodio-Ramirez, V.; Paz, C.

2010-01-01

In radiotherapy and stereotactic radiosurgery, small animal experimental models are frequently used, since there are still a lot of unsolved questions about the biological and biochemical effects of ionizing radiation. This work presents a method for small-animal brain radiotherapy compatible with a dedicated 6MV Linac. This rodent model is focused on the research of the inflammatory effects produced by ionizing radiation in the brain. In this work comparisons between Pencil Beam and Monte Carlo techniques, were used in order to evaluate accuracy of the calculated dose using a commercial planning system. Challenges in this murine model are discussed.

Genetic algorithms and experimental discrimination of SUSY models

International Nuclear Information System (INIS)

Allanach, B.C.; Quevedo, F.; Grellscheid, D.

2004-01-01

We introduce genetic algorithms as a means to estimate the accuracy required to discriminate among different models using experimental observables. We exemplify the technique in the context of the minimal supersymmetric standard model. If supersymmetric particles are discovered, models of supersymmetry breaking will be fit to the observed spectrum and it is beneficial to ask beforehand: what accuracy is required to always allow the discrimination of two particular models and which are the most important masses to observe? Each model predicts a bounded patch in the space of observables once unknown parameters are scanned over. The questions can be answered by minimising a 'distance' measure between the two hypersurfaces. We construct a distance measure that scales like a constant fraction of an observable, since that is how the experimental errors are expected to scale. Genetic algorithms, including concepts such as natural selection, fitness and mutations, provide a solution to the minimisation problem. We illustrate the efficiency of the method by comparing three different classes of string models for which the above questions could not be answered with previous techniques. The required accuracy is in the range accessible to the Large Hadron Collider (LHC) when combined with a future linear collider (LC) facility. The technique presented here can be applied to more general classes of models or observables. (author)

Caffeine improves attention deficit in neonatal 6-OHDA lesioned rats, an animal model of attention deficit hyperactivity disorder (ADHD).

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Caballero, Miguel; Núñez, Fabiana; Ahern, Siobhán; Cuffí, Maria L; Carbonell, Lourdes; Sánchez, Silvia; Fernández-Dueñas, Víctor; Ciruela, Francisco

2011-04-20

Nowadays the pharmacological treatment of the attention deficit hyperactivity disorder (ADHD) is based on amphetamine derivatives (i.e. methylphenidate). However, these drugs induce a large array of adverse side effects, thus less aggressive psychostimulant drugs (i.e. caffeine) are being proposed in the management of ADHD. Following this tendency, we decided to study the possible therapeutic use of caffeine in an animal model of ADHD, namely the neonatal 6-hydroxy-dopamine (6-OHDA)-lesioned rat. Therefore, at postnatal day 7 rats were lesioned at the left striatum with 6-OHDA or with saline. Thereafter, at postnatal day 25 their activity and attention were measured with the Olton maze before caffeine was administered ad libitum in the drinking water. Next, after 14 days of caffeine treatment, we repeated these measurements to assess the effect of caffeine on motor activity and attention deficit. Interestingly, while no changes in the motor activity measurements were observed before and after caffeine administration, a significant improvement in the attention deficit of the 6-OHDA lesioned rats was achieved after caffeine treatment. Thus, our results led us to hypothesize that caffeine might be useful to manage the attention deficit during the prepubertal period of ADHD. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Vitamin D Repletion Reduces the Progression of Premalignant Squamous Lesions in the NTCU Lung Squamous Cell Carcinoma Mouse Model

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Mazzilli, Sarah A.; Hershberger, Pamela A.; Reid, Mary E.; Bogner, Paul N.; Atwood, Kristopher; Trump, Donald L.; Johnson, Candace S.

2015-01-01

The chemopreventive actions of vitamin D were examined in the N-nitroso-tris-chloroethylurea (NTCU) mouse model, a progressive model of lung squamous cell carcinoma (SCC). SWR/J mice were fed a deficient diet (D) containing no vitamin D3, a sufficient diet (S) containing 2000 IU/kg vitamin D3, or the same diets in combination with the active metabolite of vitamin D, calcitriol (C) (80 μg/kg, weekly). The percentage (%) of the mucosal surface of large airways occupied by dysplastic lesions was determined in mice after treatment with a total dose of 15 or 25 μmol NTCU (N). After treatment with 15 μmol NTCU, the % of the surface of large airways containing high-grade dysplastic (HGD) lesions were vitamin D-deficient +NTCU (DN), 22.7 % (p<0.05 compared to vitamin D-sufficient +NTCU (SN)); DN + C, 12.3%; SN, 8.7%; and SN + C, 6.6%. The extent of HGD increased with NTCU dose in the DN group. Proliferation, assessed by Ki-67 labeling, increased upon NTCU treatment. The highest Ki-67 labeling index was seen in the DN group. As compared to SN mice, DN mice exhibited a 3-fold increase (p <0.005) in circulating white blood cells (WBC), a 20% (p <0.05) increase in IL-6 levels, and a 4 -fold (p <0.005) increase in WBC in bronchial lavages. Thus, vitamin D repletion reduces the progression of premalignant lesions, proliferation, and inflammation, and may thereby suppress development of lung SCC. Further investigations of the chemopreventive effects of vitamin D in lung SCC are warranted. PMID:26276745

Experimental model of cutaneous radiation injury in rabbits

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Meirelles, Rafael Panisi de Campos [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina; Hochman, Bernardo [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Medicina. Dept. de Cirurgia; Helene Junior, Americo; Fraga, Murillo Francisco Pires [Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo (FCMSCSP), SP (Brazil). Dept. de Cirurgia. Divisao de Cirurgia Plastica; Lellis, Rute [Faculdade de Ciencias Medicas da Santa Casa de Sao Paulo (FCMSCSP), SP (Brazil). Divisao de Patologia; Ferreira, Lydia Masako, E-mail: rpcmeirelles@yahoo.com.br, E-mail: lydia.dcir@epm.br [Universidade Federal de Sao Paulo (EPM/UNIFESP), SP (Brazil). Escola Paulista de Mediciana. Divisao de Cirugia Plastica

2013-07-01

Purpose: to describe an experimental model of cutaneous radiation injury in rabbits. Methods: on this study eight six-month-old New Zealand male rabbits, with an average weight of 2.5kg were used. They were distributed in four groups (n=2 per group). The control group did not receive radiotherapy and the others received one radiotherapy session of 2000, 3000 and 4500 cGy, respectively. Photographic analysis and histopathological evaluation of the irradiated areas were carried out. Results: after 30 days, the animals from the control group had all their hair grown. In spite of that, the animals from group 2000 cGy had a 60-day alopecia and from group 3000 cGy, a 90-day alopecia. After the 30th day, the 3000cGy group demonstrated 90-day cutaneous radiation injuries, graded 3 and 4. One of the animals from group 4500 cGy died on the 7th day with visceral necrosis. The other from the same group had total skin necrosis. A progressive reduction of glands and blood vessels count and an increase on collagen deposition was observed. Conclusion: The proposed experimental model is reproducible. This study suggests that the dosage 4500cGy is excessive and the 3000 cGy is the most effective for this experimental model of cutaneous radiation injury in rabbits. (author)

OASIS is Automated Statistical Inference for Segmentation, with applications to multiple sclerosis lesion segmentation in MRI.

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Sweeney, Elizabeth M; Shinohara, Russell T; Shiee, Navid; Mateen, Farrah J; Chudgar, Avni A; Cuzzocreo, Jennifer L; Calabresi, Peter A; Pham, Dzung L; Reich, Daniel S; Crainiceanu, Ciprian M

2013-01-01

Magnetic resonance imaging (MRI) can be used to detect lesions in the brains of multiple sclerosis (MS) patients and is essential for diagnosing the disease and monitoring its progression. In practice, lesion load is often quantified by either manual or semi-automated segmentation of MRI, which is time-consuming, costly, and associated with large inter- and intra-observer variability. We propose OASIS is Automated Statistical Inference for Segmentation (OASIS), an automated statistical method for segmenting MS lesions in MRI studies. We use logistic regression models incorporating multiple MRI modalities to estimate voxel-level probabilities of lesion presence. Intensity-normalized T1-weighted, T2-weighted, fluid-attenuated inversion recovery and proton density volumes from 131 MRI studies (98 MS subjects, 33 healthy subjects) with manual lesion segmentations were used to train and validate our model. Within this set, OASIS detected lesions with a partial area under the receiver operating characteristic curve for clinically relevant false positive rates of 1% and below of 0.59% (95% CI; [0.50%, 0.67%]) at the voxel level. An experienced MS neuroradiologist compared these segmentations to those produced by LesionTOADS, an image segmentation software that provides segmentation of both lesions and normal brain structures. For lesions, OASIS out-performed LesionTOADS in 74% (95% CI: [65%, 82%]) of cases for the 98 MS subjects. To further validate the method, we applied OASIS to 169 MRI studies acquired at a separate center. The neuroradiologist again compared the OASIS segmentations to those from LesionTOADS. For lesions, OASIS ranked higher than LesionTOADS in 77% (95% CI: [71%, 83%]) of cases. For a randomly selected subset of 50 of these studies, one additional radiologist and one neurologist also scored the images. Within this set, the neuroradiologist ranked OASIS higher than LesionTOADS in 76% (95% CI: [64%, 88%]) of cases, the neurologist 66% (95% CI: [52%, 78

Imaging inflammatory acne: lesion detection and tracking

Science.gov (United States)

Cula, Gabriela O.; Bargo, Paulo R.; Kollias, Nikiforos

2010-02-01

It is known that effectiveness of acne treatment increases when the lesions are detected earlier, before they could progress into mature wound-like lesions, which lead to scarring and discoloration. However, little is known about the evolution of acne from early signs until after the lesion heals. In this work we computationally characterize the evolution of inflammatory acne lesions, based on analyzing cross-polarized images that document acne-prone facial skin over time. Taking skin images over time, and being able to follow skin features in these images present serious challenges, due to change in the appearance of skin, difficulty in repositioning the subject, involuntary movement such as breathing. A computational technique for automatic detection of lesions by separating the background normal skin from the acne lesions, based on fitting Gaussian distributions to the intensity histograms, is presented. In order to track and quantify the evolution of lesions, in terms of the degree of progress or regress, we designed a study to capture facial skin images from an acne-prone young individual, followed over the course of 3 different time points. Based on the behavior of the lesions between two consecutive time points, the automatically detected lesions are classified in four categories: new lesions, resolved lesions (i.e. lesions that disappear completely), lesions that are progressing, and lesions that are regressing (i.e. lesions in the process of healing). The classification our methods achieve correlates well with visual inspection of a trained human grader.

Solitary sternal lesions in breast cancer. Lesiones esternales unicas en cancer de mama

Energy Technology Data Exchange (ETDEWEB)

Morales, R; Cano, R; Mendoza, G [Instituto Peruano de Energia Nuclear, Lima (Peru); Guzman, C; Cotrina, M; Aguilar, C [Instituto Nacional de Enfermedades Neoplasicas, Lima (Peru)

1993-12-01

In a retrospective review of bone scans performed in 1740 patients with breast cancer from January 1988 to April 1993, twenty had a solitary sternal lesion. Etiology was found correlating this finding with pathology, x-rays and/or final outcome. Nineteen lesions were due to metastases and one to infection. This experience suggests that solitary sternal lesions in breast cancer patients are uncommon and are most frequently (95%) associated with malignant etiology. (Authors). 10 refs., 2 figs.

Preliminary evaluation of data mining on non-masslike enhancement of breast lesions on MRI

International Nuclear Information System (INIS)

Tan Hongna; Li Ruimin; Wang Peihua; Tang Feng; Mao Jian; Shen Xigang; Qian Min; Gu Yajia; Su Yi; Chen Ying

2009-01-01

Objective: To evaluate the diagnostic values of the breast imaging reporting and data system-MRI (BI-RADS-MRI)description about non-masslike enhancement by data mining. Methods: Fifty- five patients with non-masslike enhancement lesions showed on breast contrast-enhanced MRI were evaluated using two data mining algorithms (Logistic regression and decision tree) and 10-fold cross-validation methods. Results: There were 28 malignant and 27 benign lesions. The most frequent findings of the malignant lesions were clustered ring enhancement and clumped enhancement [12 and 4 lesions, respectively; 84.2% (16/19) in decision trees, partial regression coefficients in Logistic model were 2.128 and 1.723, respectively], whereas homogenous, stippled, reticular internal and linear ductal enhancement were the most frequent findings in benign lesions [4,9,1 and 7 lesions, respectively; 72.4% (21/29) in decision tree, partial regression coefficients in Logistic model were 0.357 (homogenous), 1.861 (stippled) and 18.870(reticular), respectively]. 10-fold cross-validation indicated that decision tree (C5.0) achieved an accuracy of 69.3% with a sensitivity of 66.7% and a specificity of 71.7% in comparison to the Logistic regression model with an accuracy of 57.0%, a sensitivity of 43.3% and a specificity of 71.7%. Conclusions: The diagnosis efficacy of non-masslike enhancement interpretation according to BI-RADS-MRI is not high. It is very important to find more potential features of non-masslike enhancement to improve the diagnosis accuracy. (authors)

Novel techniques for enhancement and segmentation of acne vulgaris lesions.

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Malik, A S; Humayun, J; Kamel, N; Yap, F B-B

2014-08-01

More than 99% acne patients suffer from acne vulgaris. While diagnosing the severity of acne vulgaris lesions, dermatologists have observed inter-rater and intra-rater variability in diagnosis results. This is because during assessment, identifying lesion types and their counting is a tedious job for dermatologists. To make the assessment job objective and easier for dermatologists, an automated system based on image processing methods is proposed in this study. There are two main objectives: (i) to develop an algorithm for the enhancement of various acne vulgaris lesions; and (ii) to develop a method for the segmentation of enhanced acne vulgaris lesions. For the first objective, an algorithm is developed based on the theory of high dynamic range (HDR) images. The proposed algorithm uses local rank transform to generate the HDR images from a single acne image followed by the log transformation. Then, segmentation is performed by clustering the pixels based on Mahalanobis distance of each pixel from spectral models of acne vulgaris lesions. Two metrics are used to evaluate the enhancement of acne vulgaris lesions, i.e., contrast improvement factor (CIF) and image contrast normalization (ICN). The proposed algorithm is compared with two other methods. The proposed enhancement algorithm shows better result than both the other methods based on CIF and ICN. In addition, sensitivity and specificity are calculated for the segmentation results. The proposed segmentation method shows higher sensitivity and specificity than other methods. This article specifically discusses the contrast enhancement and segmentation for automated diagnosis system of acne vulgaris lesions. The results are promising that can be used for further classification of acne vulgaris lesions for final grading of the lesions. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Macrophages and Uveitis in Experimental Animal Models

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Salvador Mérida

2015-01-01

Full Text Available Resident and infiltrated macrophages play relevant roles in uveitis as effectors of innate immunity and inductors of acquired immunity. They are major effectors of tissue damage in uveitis and are also considered to be potent antigen-presenting cells. In the last few years, experimental animal models of uveitis have enabled us to enhance our understanding of the leading role of macrophages in eye inflammation processes, including macrophage polarization in experimental autoimmune uveoretinitis and the major role of Toll-like receptor 4 in endotoxin-induced uveitis. This improved knowledge should guide advantageous iterative research to establish mechanisms and possible therapeutic targets for human uveitis resolution.

Numerical modelling and experimental study of liquid evaporation during gel formation

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Pokusaev, B. G.; Khramtsov, D. P.

2017-11-01

Gels are promising materials in biotechnology and medicine as a medium for storing cells for bioprinting applications. Gel is a two-phase system consisting of solid medium and liquid phase. Understanding of a gel structure evolution and gel aging during liquid evaporation is a crucial step in developing new additive bioprinting technologies. A numerical and experimental study of liquid evaporation was performed. In experimental study an evaporation process of an agarose gel layer located on Petri dish was observed and mass difference was detected using electronic scales. Numerical model was based on a smoothed particle hydrodynamics method. Gel in a model was represented as a solid-liquid system and liquid evaporation was modelled due to capillary forces and heat transfer. Comparison of experimental data and numerical results demonstrated that model can adequately represent evaporation process in agarose gel.

Model observer for assessing digital breast tomosynthesis for multi-lesion detection in the presence of anatomical noise

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Wen, Gezheng; Markey, Mia K.; Miner Haygood, Tamara; Park, Subok

2018-02-01

Model observers are widely used in task-based assessments of medical image quality. The presence of multiple abnormalities in a single set of images, such as in multifocal multicentric breast cancer (MFMC), has an immense clinical impact on treatment planning and survival outcomes. Detecting multiple breast tumors is challenging as MFMC is relatively uncommon, and human observers do not know the number or locations of tumors a priori. Digital breast tomosynthesis (DBT), in which an x-ray beam sweeps over a limited angular range across the breast, has the potential to improve the detection of multiple tumors. However, prior studies of DBT image quality all focus on unifocal breast cancers. In this study, we extended our 2D multi-lesion (ML) channelized Hotelling observer (CHO) into a 3D ML-CHO that detects multiple lesions from volumetric imaging data. Then we employed the 3D ML-CHO to identify optimal DBT acquisition geometries for detection of MFMC. Digital breast phantoms with multiple embedded synthetic lesions were scanned by simulated DBT scanners of different geometries (wide/narrow angular span, different number of projections per scan) to simulate MFMC cases. With new implementations of 3D partial least squares (PLS) and modified Laguerre-Gauss (LG) channels, the 3D ML-CHO made detection decisions based upon the overall information from individual DBT slices and their correlations. Our evaluation results show that: (1) the 3D ML-CHO could achieve good detection performance with a small number of channels, and 3D PLS channels on average outperform the counterpart LG channels; (2) incorporating locally varying anatomical backgrounds and their correlations as in the 3D ML-CHO is essential for multi-lesion detection; (3) the most effective DBT geometry for detection of MFMC may vary when the task of clinical interest changes, and a given DBT geometry may not yield images that are equally informative for detecting MF, MC, and unifocal cancers.

Constitutive Model Calibration via Autonomous Multiaxial Experimentation (Postprint)

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2016-09-17

ABSTRACT (Maximum 200 words) Modern plasticity models contain numerous parameters that can be difficult and time consuming to fit using current...Abstract Modern plasticity models contain numerous parameters that can be difficult and time consuming to fit using current methods. Additional...complexity, is a difficult and time consuming process that has historically be a separate process from the experimental testing. As such, additional

Analysis of lesions in patients with unilateral tactile agnosia using cytoarchitectonic probabilistic maps.

Science.gov (United States)

Hömke, Lars; Amunts, Katrin; Bönig, Lutz; Fretz, Christian; Binkofski, Ferdinand; Zilles, Karl; Weder, Bruno

2009-05-01

We propose a novel methodical approach to lesion analyses involving high-resolution MR images in combination with probabilistic cytoarchitectonic maps. 3D-MR images of the whole brain and the manually segmented lesion mask are spatially normalized to the reference brain of a stereotaxic probabilistic cytoarchitectonic atlas using a multiscale registration algorithm based on an elastic model. The procedure is demonstrated in three patients suffering from aperceptive tactile agnosia of the right hand due to chronic infarction of the left parietal cortex. Patient 1 presents a lesion in areas of the postcentral sulcus, Patient 3 in areas of the superior parietal lobule and adjacent intraparietal sulcus, and Patient 2 lesions in both regions. On the basis of neurobehavioral data, we conjectured degradation of sequential elementary sensory information processing within the postcentral gyrus, impeding texture recognition in Patients 1 and 2, and disturbed kinaesthetic information processing in the posterior parietal lobe, causing degraded shape recognition in the patients 2 and 3. The involvement of Brodmann areas 4a, 4p, 3a, 3b, 1, 2, and areas IP1 and IP2 of the intraparietal sulcus was assessed in terms of the voxel overlap between the spatially transformed lesion masks and the 50%-isocontours of the cytoarchitectonic maps. The disruption of the critical cytoarchitectonic areas and the impaired subfunctions, texture and shape recognition, relate as conjectured above. We conclude that the proposed method represents a promising approach to hypothesis-driven lesion analyses, yielding lesion-function correlates based on a cytoarchitectonic model. Finally, the lesion-function correlates are validated by functional imaging reference data. (c) 2008 Wiley-Liss, Inc.

Dynamic multislice helical CT of maxillomandibular lesions. Distinction of ameloblastomas from other cystic lesions

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Tozaki, Mitsuhiro; Hayashi, Katsuhiko; Fukuda, Kunihiko [Jikei Univ., Tokyo (Japan). School of Medicine

2001-10-01

The purpose of this study was to evaluate the clinical usefulness of dynamic multislice helical CT in differentiating ameloblastoma from other cystic lesions in cases of maxillomandibular cystic lesions. The study included 32 patients with maxillomandibular cystic lesions (ameloblastoma [n=6], myxofibroma [n=1], odontogenic keratocyst [n=3], dentigerous cyst [n=11], radicular cyst [n=11], and paradental cyst [n=2]). Dynamic study was performed before and 30 sec, and 90 sec after intravenous contrast medium administration. CT density values and percentage of density increase were calculated at 30 and 90 sec. In five cases of ameloblastoma, a rapidly enhancing area was detected within the cystic lesions at 30 sec, while no apparent rapid enhancement was seen in the other cystic lesions. Three cysts showed gradual enhancement in the marginal area at 90 sec. Comparing ameloblastoma and other kinds of cysts, we found significant differences in the percentage of density increase at 30 sec (p<0.01) and 90 sec (p<0.05). Dynamic multislice helical CT is useful in the diagnosis of cystic lesions of the maxillomandibular region, especially in the detection of neovascularities in ameloblastoma. (author)

Dynamic multislice helical CT of maxillomandibular lesions. Distinction of ameloblastomas from other cystic lesions

International Nuclear Information System (INIS)

Tozaki, Mitsuhiro; Hayashi, Katsuhiko; Fukuda, Kunihiko

2001-01-01

The purpose of this study was to evaluate the clinical usefulness of dynamic multislice helical CT in differentiating ameloblastoma from other cystic lesions in cases of maxillomandibular cystic lesions. The study included 32 patients with maxillomandibular cystic lesions (ameloblastoma [n=6], myxofibroma [n=1], odontogenic keratocyst [n=3], dentigerous cyst [n=11], radicular cyst [n=11], and paradental cyst [n=2]). Dynamic study was performed before and 30 sec, and 90 sec after intravenous contrast medium administration. CT density values and percentage of density increase were calculated at 30 and 90 sec. In five cases of ameloblastoma, a rapidly enhancing area was detected within the cystic lesions at 30 sec, while no apparent rapid enhancement was seen in the other cystic lesions. Three cysts showed gradual enhancement in the marginal area at 90 sec. Comparing ameloblastoma and other kinds of cysts, we found significant differences in the percentage of density increase at 30 sec (p<0.01) and 90 sec (p<0.05). Dynamic multislice helical CT is useful in the diagnosis of cystic lesions of the maxillomandibular region, especially in the detection of neovascularities in ameloblastoma. (author)

Virtual In-Silico Modeling Guided Catheter Ablation Predicts Effective Linear Ablation Lesion Set for Longstanding Persistent Atrial Fibrillation: Multicenter Prospective Randomized Study.

Science.gov (United States)

Shim, Jaemin; Hwang, Minki; Song, Jun-Seop; Lim, Byounghyun; Kim, Tae-Hoon; Joung, Boyoung; Kim, Sung-Hwan; Oh, Yong-Seog; Nam, Gi-Byung; On, Young Keun; Oh, Seil; Kim, Young-Hoon; Pak, Hui-Nam

2017-01-01

Objective: Radiofrequency catheter ablation for persistent atrial fibrillation (PeAF) still has a substantial recurrence rate. This study aims to investigate whether an AF ablation lesion set chosen using in-silico ablation (V-ABL) is clinically feasible and more effective than an empirically chosen ablation lesion set (Em-ABL) in patients with PeAF. Methods: We prospectively included 108 patients with antiarrhythmic drug-resistant PeAF (77.8% men, age 60.8 ± 9.9 years), and randomly assigned them to the V-ABL ( n = 53) and Em-ABL ( n = 55) groups. Five different in-silico ablation lesion sets [1 pulmonary vein isolation (PVI), 3 linear ablations, and 1 electrogram-guided ablation] were compared using heart-CT integrated AF modeling. We evaluated the feasibility, safety, and efficacy of V-ABL compared with that of Em-ABL. Results: The pre-procedural computing time for five different ablation strategies was 166 ± 11 min. In the Em-ABL group, the earliest terminating blinded in-silico lesion set matched with the Em-ABL lesion set in 21.8%. V-ABL was not inferior to Em-ABL in terms of procedure time ( p = 0.403), ablation time ( p = 0.510), and major complication rate ( p = 0.900). During 12.6 ± 3.8 months of follow-up, the clinical recurrence rate was 14.0% in the V-ABL group and 18.9% in the Em-ABL group ( p = 0.538). In Em-ABL group, clinical recurrence rate was significantly lower after PVI+posterior box+anterior linear ablation, which showed the most frequent termination during in-silico ablation (log-rank p = 0.027). Conclusions: V-ABL was feasible in clinical practice, not inferior to Em-ABL, and predicts the most effective ablation lesion set in patients who underwent PeAF ablation.

Investigation of approximate models of experimental temperature characteristics of machines

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Parfenov, I. V.; Polyakov, A. N.

2018-05-01

This work is devoted to the investigation of various approaches to the approximation of experimental data and the creation of simulation mathematical models of thermal processes in machines with the aim of finding ways to reduce the time of their field tests and reducing the temperature error of the treatments. The main methods of research which the authors used in this work are: the full-scale thermal testing of machines; realization of various approaches at approximation of experimental temperature characteristics of machine tools by polynomial models; analysis and evaluation of modelling results (model quality) of the temperature characteristics of machines and their derivatives up to the third order in time. As a result of the performed researches, rational methods, type, parameters and complexity of simulation mathematical models of thermal processes in machine tools are proposed.

FFA STUDY OF MACULAR LESIONS

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K. Vinayagamurthy

2017-08-01

Full Text Available BACKGROUND Macula is an important portion of retina that occupies the posterior pole of retina. Any disease that affects macula results in significant loss of central vision, form vision and colour vision to an extent. Macular lesions can be hereditary as well as acquired. Macular lesions occur in both younger and older individuals. Anatomically, a macular lesions can vary from a simple lesion like an RPF defect to a vision-threatening lesions like choroidal neovascular membrane. Many screening tests that are sensitive and specific are available to assess the functioning of macula called as ‘macular function test’. But, the greater understanding of the retinal vascular led to the usage of fluorescein angiogram in the detection and screening of macular, retinovascular and optic disc lesions. Through fundus fluorescein angiogram is a thirty-year-old procedure; it is still in vogue in almost all parts of the world. It has its own merits. The aim of the study is to study the role of fluorescein angiography in the evaluation of macular lesions. MATERIALS AND METHODS A hospital-based prospective randomised study was done, which included 50 patients. Detailed patient history was taken and thorough ocular and systemic examination was done. All patients were examined by ophthalmoscopy (direct and indirect and slit-lamp examination with 90D followed by fluorescein angiography. Ophthalmoscopic and fluorescein angiography findings were analysed and categorised. Patients were advised proper ocular and systemic treatment and follow up. RESULTS 50 cases with macular lesions were analysed and categorised into conditions like ARMD, CSR, macular oedema, CME, degenerations and dystrophies and miscellaneous conditions. FFA altered the diagnosis in 8% cases and categorised the cases in all cases. 16% patients developed adverse reactions like allergy, vomiting and nausea. On statistical analysis, FFA proved to be cheap and superior diagnostic tool in confirming

Unilateral Lesion of Dopamine Neurons Induces Grooming Asymmetry in the Mouse.

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Pelosi, Assunta; Girault, Jean-Antoine; Hervé, Denis

2015-01-01

Grooming behaviour is the most common innate behaviour in animals. In rodents, it consists of sequences of movements organized in four phases, executed symmetrically on both sides of the animal and creating a syntactic chain of behavioural events. The grooming syntax can be altered by stress and novelty, as well as by several mutations and brain lesions. Grooming behaviour is known to be affected by alterations of the dopamine system, including dopamine receptor modulation, dopamine alteration in genetically modified animals, and after brain lesion. While a lot is known about the initiation and syntactic modifications of this refined sequence of movements, effects of unilateral lesion of dopamine neurons are unclear particularly regarding the symmetry of syntactic chains. In the present work we studied grooming in mice unilaterally lesioned in the medial forebrain bundle by 6-hydroxydopamine. We found a reduction in completion of grooming bouts, associated with reduction in number of transitions between grooming phases. The data also revealed the development of asymmetry in grooming behaviour, with reduced tendency to groom the contralateral side to the lesion. Symmetry was recovered following treatment with L-DOPA. Thus, the present work shows that unilateral lesion of dopamine neurons reduces self-grooming behaviour by affecting duration and numbers of events. It produces premature discontinuation of grooming chains but the sequence syntax remains correct. This deficient grooming could be considered as an intrinsic symptom of Parkinson's disease in animal models and could present some similarities with abnormalities of motor movement sequencing seen in patients. Our study also suggests grooming analysis as an additional method to screen parkinsonism in animal models.

Entropy-Based Experimental Design for Optimal Model Discrimination in the Geosciences

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Wolfgang Nowak

2016-11-01

Full Text Available Choosing between competing models lies at the heart of scientific work, and is a frequent motivation for experimentation. Optimal experimental design (OD methods maximize the benefit of experiments towards a specified goal. We advance and demonstrate an OD approach to maximize the information gained towards model selection. We make use of so-called model choice indicators, which are random variables with an expected value equal to Bayesian model weights. Their uncertainty can be measured with Shannon entropy. Since the experimental data are still random variables in the planning phase of an experiment, we use mutual information (the expected reduction in Shannon entropy to quantify the information gained from a proposed experimental design. For implementation, we use the Preposterior Data Impact Assessor framework (PreDIA, because it is free of the lower-order approximations of mutual information often found in the geosciences. In comparison to other studies in statistics, our framework is not restricted to sequential design or to discrete-valued data, and it can handle measurement errors. As an application example, we optimize an experiment about the transport of contaminants in clay, featuring the problem of choosing between competing isotherms to describe sorption. We compare the results of optimizing towards maximum model discrimination with an alternative OD approach that minimizes the overall predictive uncertainty under model choice uncertainty.

Experimental transconjunctival diode laser retinal photocoagulation through silicone scleral exoplants.

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Nanda, S K; Han, D P

1995-07-01

To study the feasibility of inducing a chorioretinal lesion under a previously placed scleral buckle by experimental transconjunctival diode laser photocoagulation. We performed transconjunctival diode laser photocoagulation in the peripheral retinas of seven pigmented rabbit eyes with a silicone exoplant (No. 42 band or No. 276 tire) and seven eyes without an exoplant. Each eye received burns with an intensity of grades 1 to 3 in different quadrants at varying power levels, with a 0.5-second duration and 650-micron spot size. Eyes were enucleated for histopathologic studies 1 day and 1 week after treatment. Although the irradiance emitted through the No. 42 band and the No. 276 tire was attenuated by 17% and 23%, respectively, the range of threshold powers needed to produce grades 1 to 3 burns was similar between eyes with and without a silicone exoplant. At 1 day, full-thickness coagulative necrosis was observed in all lesions, except that the ganglion cell layer and inner nuclear layer were preserved in two of four grade 1 burns and the ganglion cell layer was intact in one of six grade 2 burns. Inner scleral changes were noted acutely in three of five grade 3 lesions. At 1 week, burns of all intensity grades showed a full-thickness atrophic chorioretinal lesion with inner scleral changes. Experimental transconjunctival diode laser photocoagulation through hard silicone elements reproducibly created a chorioretinal lesion with histopathologic findings similar to those of lesions obtained without these elements. Although retinal photocoagulative effects were prominent, inner scleral abnormalities were also observed histologically.

Effects of lesions of the amygdala central nucleus on autoshaped lever pressing

Science.gov (United States)

Chang, Stephen E.; Wheeler, Daniel S.; Holland, Peter C.

2012-01-01

Neutral cues paired with rewards often appear to acquire motivational significance, as if the incentive motivational value of the reward is transferred to the cue. Such cues have been reported to modulate the performance of instrumental action (Pavlovian-instrumental transfer, PIT), serve as conditioned reinforcers in the establishment of new learning, and be the targets of approach and other cue-directed behaviors. Here we examined the effects of lesions of the amygdala central nucleus (CeA) on the acquisition of discriminative autoshaped lever-pressing. Insertion of one lever into the experimental chamber was reinforced by sucrose delivery, but insertion of another lever was not reinforced. Although sucrose delivery was not contingent on lever pressing, both CeA- and sham-lesioned rats rapidly came to press the reinforced but not the nonreinforced lever. Despite their showing little evidence of impairments in autoshaped lever pressing, these same CeA-lesioned rats showed significant deficits in the expression of PIT in a subsequent phase of the experiment. The lack of impaired autoshaping in CeA-lesioned rats contrasts with effects previously reported for conditioned orienting responses (ORs) and for other putative measures of incentive learning including PIT and conditioned approach to visual cues. PMID:22386516

Pneumatic Adaptive Absorber: Mathematical Modelling with Experimental Verification

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Grzegorz Mikułowski

2016-01-01

Full Text Available Many of mechanical energy absorbers utilized in engineering structures are hydraulic dampers, since they are simple and highly efficient and have favourable volume to load capacity ratio. However, there exist fields of applications where a threat of toxic contamination with the hydraulic fluid contents must be avoided, for example, food or pharmacy industries. A solution here can be a Pneumatic Adaptive Absorber (PAA, which is characterized by a high dissipation efficiency and an inactive medium. In order to properly analyse the characteristics of a PAA, an adequate mathematical model is required. This paper proposes a concept for mathematical modelling of a PAA with experimental verification. The PAA is considered as a piston-cylinder device with a controllable valve incorporated inside the piston. The objective of this paper is to describe a thermodynamic model of a double chamber cylinder with gas migration between the inner volumes of the device. The specific situation considered here is that the process cannot be defined as polytropic, characterized by constant in time thermodynamic coefficients. Instead, the coefficients of the proposed model are updated during the analysis. The results of the experimental research reveal that the proposed mathematical model is able to accurately reflect the physical behaviour of the fabricated demonstrator of the shock absorber.

An experimental and modeling study of diethyl carbonate oxidation

KAUST Repository

Nakamura, Hisashi; Curran, Henry J.; Polo-Có rdoba, Á ngel David; Pitz, William J.; Dagaut, P.; Togbé , Casimir; Sarathy, Mani; Mehl, Marco; Agudelo, John Ramiro; Bustamante, Felipe

2015-01-01

Diethyl carbonate (DEC) is an attractive biofuel that can be used to displace petroleum-derived diesel fuel, thereby reducing CO2 and particulate emissions from diesel engines. A better understanding of DEC combustion characteristics is needed to facilitate its use in internal combustion engines. Toward this goal, ignition delay times for DEC were measured at conditions relevant to internal combustion engines using a rapid compression machine (RCM) and a shock tube. The experimental conditions investigated covered a wide range of temperatures (660-1300K), a pressure of 30bar, and equivalence ratios of 0.5, 1.0 and 2.0 in air. To provide further understanding of the intermediates formed in DEC oxidation, species concentrations were measured in a jet-stirred reactor at 10atm over a temperature range of 500-1200K and at equivalence ratios of 0.5, 1.0 and 2.0. These experimental measurements were used to aid the development and validation of a chemical kinetic model for DEC.The experimental results for ignition in the RCM showed near negative temperature coefficient (NTC) behavior. Six-membered alkylperoxy radical (RO˙2) isomerizations are conventionally thought to initiate low-temperature branching reactions responsible for NTC behavior, but DEC has no such possible 6- and 7-membered ring isomerizations. However, its molecular structure allows for 5-, 8- and 9-membered ring RO˙2 isomerizations. To provide accurate rate constants for these ring structures, ab initio computations for RO˙2⇌Q˙OOH isomerization reactions were performed. These new RO˙2 isomerization rate constants have been implemented in a chemical kinetic model for DEC oxidation. The model simulations have been compared with ignition delay times measured in the RCM near the NTC region. Results of the simulation were also compared with experimental results for ignition in the high-temperature region and for species concentrations in the jet-stirred reactor. Chemical kinetic insights into the

An experimental and modeling study of diethyl carbonate oxidation

KAUST Repository

Nakamura, Hisashi

2015-04-01

Diethyl carbonate (DEC) is an attractive biofuel that can be used to displace petroleum-derived diesel fuel, thereby reducing CO2 and particulate emissions from diesel engines. A better understanding of DEC combustion characteristics is needed to facilitate its use in internal combustion engines. Toward this goal, ignition delay times for DEC were measured at conditions relevant to internal combustion engines using a rapid compression machine (RCM) and a shock tube. The experimental conditions investigated covered a wide range of temperatures (660-1300K), a pressure of 30bar, and equivalence ratios of 0.5, 1.0 and 2.0 in air. To provide further understanding of the intermediates formed in DEC oxidation, species concentrations were measured in a jet-stirred reactor at 10atm over a temperature range of 500-1200K and at equivalence ratios of 0.5, 1.0 and 2.0. These experimental measurements were used to aid the development and validation of a chemical kinetic model for DEC.The experimental results for ignition in the RCM showed near negative temperature coefficient (NTC) behavior. Six-membered alkylperoxy radical (RO˙2) isomerizations are conventionally thought to initiate low-temperature branching reactions responsible for NTC behavior, but DEC has no such possible 6- and 7-membered ring isomerizations. However, its molecular structure allows for 5-, 8- and 9-membered ring RO˙2 isomerizations. To provide accurate rate constants for these ring structures, ab initio computations for RO˙2⇌Q˙OOH isomerization reactions were performed. These new RO˙2 isomerization rate constants have been implemented in a chemical kinetic model for DEC oxidation. The model simulations have been compared with ignition delay times measured in the RCM near the NTC region. Results of the simulation were also compared with experimental results for ignition in the high-temperature region and for species concentrations in the jet-stirred reactor. Chemical kinetic insights into the