Isolated splenic metastasis from a thymic carcinoma: A case report.

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Chen, Dongmei; Meng, Xiangying; Zhao, Yaowei; Wu, Shikai

2016-09-01

Thymic carcinomas are rare tumors that arise in the anterior mediastinum. Most of these malignancies develop local metastases limited in the thorax. Splenic metastases from thymic carcinomas are extremely rare. Here we report a case of isolated splenic metastasis from a 38-year-old female patient with Stage IV thymic carcinoma, who was treated with chemoradiotherapy. At twenty-2 months follow-up, the patient was found to have an isolated spleen metastasis, which was treated by Cyberknife with a reduced size of the metastasis, representing a partial response. Although splenic metastasis is a rare phenomenon, physicians need to be aware of the possibility of such metastases.

CT findings of lymphofollicular thymic hyperplasia in adult myasthenia gravis

International Nuclear Information System (INIS)

Liu Fugeng; Wei Jiahu; Pan Jishu; Zhou Cheng; Chen Qihang; Yu Jingying; Wu Guogeng; Xu Xianhao

2006-01-01

Objective: To evaluate the CT findings of lymphofollicular thymic hyperplasia in adult myasthenia gravis (MG). Methods: The CT findings of thymus area of 134 adult patients with lymphofollicular thymic hyperplasia in MG were reviewed, all of them with surgically and histologically proven diagnosis, and compared with the CT findings of 165 normal subjects. Results: In the group of patient, CT showed enlargement of thymus in 31 patients, 5 patients had nodule or mass ( 3 cm) and 9 patients (6.7%) had normal size thymus with soft-tissue density, it can considered with thymic hyperplasia. The spotty or streak shadow showed in other patients, though it could not be certain diagnosed as thymic hyperplasia, but could not be except it. The thymus area tissue complete replacement by fatty density were not found in patient group. The CT findings of patients had marked difference when compared with group of normal subjects (P<0.01), except the spotty or streak shadows. Conclusion: CT scan is an important method in diagnosing thymic lymphofollicular hyperplasia of MG in adult. (authors)

Thymic Carcinoma Management Patterns among International Thymic Malignancy Interest Group (ITMIG) Physicians with Consensus from the Thymic Carcinoma Working Group.

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Shepherd, Annemarie; Riely, Gregory; Detterbeck, Frank; Simone, Charles B; Ahmad, Usman; Huang, James; Korst, Robert; Rajan, Arun; Rimner, Andreas

2017-04-01

Thymic carcinomas are rare epithelial malignancies with limited data to guide management. To identify areas of agreement and variability in current clinical practice, a 16-question electronic survey was given to members of the International Thymic Malignancy Interest Group (ITMIG). Areas of controversy were discussed with the Thymic Carcinoma Working Group and consensus was achieved, as described. A total of 100 ITMIG members responded. There was general agreement regarding the role for multimodality therapy with definitive surgical resection in physically fit patients with advanced but resectable disease. Areas of controversy included the need for histologic confirmation before surgery, the role of adjuvant therapy, the optimal first-line chemotherapy regimen, and the recommended treatment course for marginally resectable disease with invasion into the great vessels, pericardium, and lungs. The results of the questionnaire provide a description of the management of thymic carcinoma by 100 ITMIG members with a specific interest or expertise in thymic malignancies. Although there was agreement in some areas, clinical practice appears to vary significantly. There is a great need for collaborative research to identify optimal evaluation and treatment strategies. Given the need for multimodality therapy in many cases, a multidisciplinary discussion of the management of patients with thymic carcinoma is critical. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Significance of thymic scintigraphy

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Baba, Hiromi; Oshiumi, Yoshihiko; Nakayama, Chikashi; Morita, Kazunori; Koga, Ichinari

1978-01-01

Thymic scintigraphy by 67 Ga-citrate and 75 Se-methionine was done on 6 cases of thymoma, and 5 cases of myasthenia gravis. Scan was positive on 5 of 6 cases of thymoma. All patients with malignant thymoma were positive. Among the 7 cases of myasthenia gravis, scintigrams revealed 2 thymomas and 1 hyperplasia on whom no thymic mass suspected. Thymic scintigraphy is useful examination when dealing with myasthenia gravis. (auth.)

Images in pediatrics: the thymic sail sign and thymic wave sign.

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Alves, Nuno D; Sousa, Marta

2013-01-01

The authors present a radiographic image portraying the "thymic sail sign" and the "thymic wave sign," both normal findings in infant radiographs and present a short description of these signs. These are distinguished from pathologic findings such as the "spinnaker-sail sign" in pneumomediastinum.

Thymic epithelial tumors: Comparison of CT and MR imaging findings of low-risk thymomas, high-risk thymomas, and thymic carcinomas

International Nuclear Information System (INIS)

Sadohara, Junko; Fujimoto, Kiminori; Mueller, Nestor L.; Kato, Seiya; Takamori, Shinzo; Ohkuma, Kazuaki; Terasaki, Hiroshi; Hayabuchi, Naofumi

2006-01-01

Objective: To assess the CT and magnetic resonance (MR) imaging findings of thymic epithelial tumors classified according to the current World Health Organization (WHO) histologic classification and to determine useful findings in differentiating the main subtypes. Materials and methods: Sixty patients with thymic epithelial tumor who underwent both CT and MR imaging were reviewed retrospectively. All cases were classified according to the 2004 WHO classification. The following findings were assessed in each case on both CT and MRI: size of tumor, contour, perimeter of capsule; homogeneity, presence of septum, hemorrhage, necrotic or cystic component within tumor; presence of mediastinal lymphadenopathy, pleural effusion, and great vessel invasion. These imaging characteristics of 30 low-risk thymomas (4 type A, 12 type AB, and 14 type B1), 18 high-risk thymomas (11 type B2 and seven type B3), and 12 thymic carcinomas on CT and MR imaging were compared using the chi-square test. Comparison between CT and MR findings was performed by using McNemar test. Results: On both CT and MR imaging, thymic carcinomas were more likely to have irregular contours (P < .001), necrotic or cystic component (P < .05), heterogeneous contrast-enhancement (P < .05), lymphadenopathy (P < .0001), and great vessel invasion (P < .001) than low-risk and high-risk thymomas. On MR imaging, the findings of almost complete capsule, septum, and homogenous enhancement were more commonly seen in low-risk thymomas than high-risk thymomas and thymic carcinomas (P < .05). MR imaging was superior to CT in the depiction of capsule, septum, or hemorrhage within tumor (all comparison, P < .05). Conclusion: The presence of irregular contour, necrotic or cystic component, heterogeneous enhancement, lymphadenopathy, and great vessel invasion on CT or MR imaging are strongly suggestive of thymic carcinomas. On MR imaging, the findings of contour, capsule, septum, and homogenous enhancement are helpful in

PPARgamma Deficiency Counteracts Thymic Senescence

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David Ernszt

2017-11-01

Full Text Available Thymic senescence contributes to increased incidence of infection, cancer and autoimmunity at senior ages. This process manifests as adipose involution. As with other adipose tissues, thymic adipose involution is also controlled by PPARgamma. This is supported by observations reporting that systemic PPARgamma activation accelerates thymic adipose involution. Therefore, we hypothesized that decreased PPARgamma activity could prevent thymic adipose involution, although it may trigger metabolic adverse effects. We have confirmed that both human and murine thymic sections show marked staining for PPARgamma at senior ages. We have also tested the thymic lobes of PPARgamma haplo-insufficient and null mice. Supporting our working hypothesis both adult PPARgamma haplo-insufficient and null mice show delayed thymic senescence by thymus histology, thymocyte mouse T-cell recombination excision circle qPCR and peripheral blood naive T-cell ratio by flow-cytometry. Delayed senescence showed dose–response with respect to PPARgamma deficiency. Functional immune parameters were also evaluated at senior ages in PPARgamma haplo-insufficient mice (null mice do not reach senior ages due to metabolic adverse affects. As expected, sustained and elevated T-cell production conferred oral tolerance and enhanced vaccination efficiency in senior PPARgamma haplo-insufficient, but not in senior wild-type littermates according to ELISA IgG measurements. Of note, humans also show increased oral intolerance issues and decreased protection by vaccines at senior ages. Moreover, PPARgamma haplo-insufficiency also exists in human known as a rare disease (FPLD3 causing metabolic adverse effects, similar to the mouse. When compared to age- and metabolic disorder-matched other patient samples (FPLD2 not affecting PPARgamma activity, FPLD3 patients showed increased human Trec (hTrec values by qPCR (within healthy human range suggesting delayed thymic senescence, in accordance with

Imaging of thymus in myasthenia gravis: From thymic hyperplasia to thymic tumor

International Nuclear Information System (INIS)

Priola, A.M.; Priola, S.M.

2014-01-01

Myasthenia gravis (MG) is an autoimmune disorder often associated with thymic abnormalities. At onset, thymic lymphoid hyperplasia (TLH) and thymoma can be found in up to 65% and 15% of patients, respectively. Diagnostic imaging is crucial in this setting in order to detect the presence and type of the thymic abnormality and in the preoperative planning, when indicated. Chest radiography has a minor role due to its low accuracy. Computed tomography is the imaging modality of choice, although the differentiation between a small thymoma and TLH that appears as a focal soft-tissue mass may be not possible. Magnetic resonance imaging (MRI) is not usually employed, but it is useful in equivocal cases, especially in differentiating focal TLH from thymoma by using chemical-shift sequences for defining the proper management. In addition, diffusion-weighted (DW)-MRI can differentiate lipid-poor normal/hyperplastic thymus from thymoma and could be useful in differentiating non-advanced from advanced thymomas. Positron emission tomography (PET)-CT is not helpful in distinguishing early from advanced thymoma but can be used to differentiate thymic carcinoma from thymoma. Hereby, we discuss the imaging features of thymic abnormalities in MG, even focusing on novel aspects of chemical-shift and DW-MRI

Thymic epithelial cells. I. Expression of strong suppressive (veto) activity in mouse thymic epithelial cell cultures

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Claesson, Mogens Helweg; Ropke, C

1990-01-01

We show that thymic epithelial cells grown under serum-free conditions in a chemically defined culture medium can act as veto cells in vitro. The veto activity of thymic epithelial cells results in inactivation of specific alloreactive cytotoxic T-cell precursors at the clonal level. It is conclu......We show that thymic epithelial cells grown under serum-free conditions in a chemically defined culture medium can act as veto cells in vitro. The veto activity of thymic epithelial cells results in inactivation of specific alloreactive cytotoxic T-cell precursors at the clonal level...

Computed tomography of thymic abnormalities

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Schnyder, P.; Candardjis, G.

1987-05-01

Computed tomographic examinations of 38 patients with surgically and histologically proven diagnosis were reviewed. Twenty subjects (52%) had an invasive thymoma and 16% an hyperplastic thymus. Myasthenia gravis was present in 6 cases (16%) of thymic abnormalities, four (10,5%) with invasive thymoma and two (5%) with thymic hyperplasia. Graves' disease was also present in one case of thymic hyperplasia. We emphasize the contribution of CT to the diagnosis and the prognosis.

Computed tomography of thymic abnormalities

International Nuclear Information System (INIS)

Schnyder, P.; Candardjis, G.

1987-01-01

Computed tomographic examinations of 38 patients with surgically and histologically proven diagnosis were reviewed. Twenty subjects (52%) had an invasive thymoma and 16% an hyperplastic thymus. Myasthenia gravis was present in 6 cases (16%) of thymic abnormalities, four (10,5%) with invasive thymoma and two (5%) with thymic hyperplasia. Graves' disease was also present in one case of thymic hyperplasia. We emphasize the contribution of CT to the diagnosis and the prognosis. (orig.)

CT differentiation of invasive thymoma and thymic carcinoma

International Nuclear Information System (INIS)

Lee, Eun Jung; Jung, Gyoo Sik; Kim, Seong Min; Huh, Jin Do; Joh, Young Duk; Shin, Mi Jung; Kim, Jung Sik; Suh, Soo Jhi

1998-01-01

In order to determine the differential points between them, we analyzed the CT findings of invasive thymoma and thymic carcinoma. We retrospectively reviewed the CT scans of 14 patients with invasive thymoma and 15 with thymic carcinoma, confirmed by surgery(n=3D19) or percutaneous needle aspiration(n=3D10) between 1988 and 1996. CT findings were evaluated in each group for intrathoracic spread(posterior, direct posterior, and anterolateral), obliteration of the fat plane between the mass and vascular structures, vessel encasement, invasion of adjacent mediastinal structures, pleural implants, mediastinal nodes and distant metastasis. Direct posterior spread was more common in thymic carcinoma than invasive thymoma;it was seen in one case (7%) of invasive thymoma and 12(80%) of thymic carcinoma(p=3D0.00). Posterior spread was seen in six cases (43%) of in vasive thymoma and nine (60%) of thymic carcinoma. Anterolateral spread was seen only in two cases (13%) of thymic carcinoma. Obliteration of the fat plane was seen in nine cases (64%) of invasive thymoma and 14 (93%) of thymic carcinoma, while vessel encasement was seen in two cases (14%) of invasive thymoma and 13(87%) of thymic carcinoma(p=3D0.00). Invasion of adjacent structures was seen in two cases (14%) of invasive thymoma and eight (53%) of thymic carcinoma. Pleural implants were more common in invasive thymoma than thymic carcinoma, being seen in six cases (43%) of the former and one (7%) of the latter(p=3D0.04). Mediastinal lymphadenopathy was seen in three cases (21%) of invasive thymoma and ten (67%) of thymic carcinoma. Distant metastases were observed only in six cases (40%) of thymic carcinoma(p=3D0.02). Although differentiation between invasive thymoma and thymic carcinoma is difficult on the basis of CT findings, there are certain differential points. Thymic carcinomas showed a higher rate of direct posterior intrathoracic spread, vessel encasement, mediastinal nodes and distant metastases than

Thymic size in uninfected infants born to HIV-positive mothers and fed with pasteurized human milk

DEFF Research Database (Denmark)

Jeppesen, Dorthe Lisbeth; Hasselbalch, H; Ersbøll, A K

2003-01-01

/weight-ratio (Ti/w) at birth and at 4 mo of age in 12 healthy uninfected infants born to HlV-infected mothers. All infants were exclusively fed pasteurized donor milk. The results were compared with those obtained from a previous cohort of exclusively breastfed, partially breastfed and exclusively formula.......8 and the mean Ti/w-ratio was 4.2. Compared with those of exclusively breastfed infants, the Ti and Ti/w-ratio of infants fed donor milk were significantly reduced (p infants compared with that in the formula-fed infants (p = 0.02). CONCLUSION: At birth...... with thymic size in infants that were exclusively formula fed....

Factors associated with thymic size at birth among low and normal birth-weight infants

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Eriksen, Helle Brander; Biering-Sørensen, Sofie; Lund, Najaaraq

2014-01-01

treatment at the time of labor (0.84 [0.70-1.00]), number of pregnancy consultations (1.03 [1.00-1.05]), maternal age (0.91 [0.84-0.98]), Apgar score (1.06 [1.03-1.10]), and infant convulsions (0.44 [0.29-0.65]) were all independent determinants of thymic index but not all were determinants of thymus....../weight index. Pathologic amniotic fluid and cesarean delivery were associated with thymus/weight index among LBW infants (0.85 [0.75-0.95] and 0.80 [0.67-0.96]) but were only borderline significant for thymic index. CONCLUSION: Exposures mainly related to stress and infections were associated with a smaller...

Gallium 67 uptake in thymic rebound

International Nuclear Information System (INIS)

Hurst, R.; Sabio, H.; Teates, C.D.

1988-01-01

We have reported a case of localized thymic enlargement and uptake of gallium 67 in a child who had received antineoplastic chemotherapy. The enlarged thymus showed normal histology, a picture consistent with thymic rebound after nonspecific stress. This case further demonstrates the need to consider thymic rebound as a cause of gallium 67 uptake in children with neoplastic diseases

Frequent silencing of RASSF1A by DNA methylation in thymic neuroendocrine tumours.

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Kajiura, Koichiro; Takizawa, Hiromitsu; Morimoto, Yuki; Masuda, Kiyoshi; Tsuboi, Mitsuhiro; Kishibuchi, Reina; Wusiman, Nuliamina; Sawada, Toru; Kawakita, Naoya; Toba, Hiroaki; Yoshida, Mitsuteru; Kawakami, Yukikiyo; Naruto, Takuya; Imoto, Issei; Tangoku, Akira; Kondo, Kazuya

2017-09-01

Aberrant methylation of promoter CpG islands (CGIs) of tumour suppressor genes is a common epigenetic mechanism underlying cancer pathogenesis. The methylation patterns of thymic tumours have not been studied in detail since such tumours are rare. Herein, we sought to identify genes that could serve as epigenetic targets for thymic neuroendocrine tumour (NET) therapy. Genome-wide screening for aberrantly methylated CGIs was performed in three NET samples, seven thymic carcinoma (TC) samples, and eight type-B3 thymoma samples. The methylation status of thymic epithelial tumours (TETs) samples was validated by pyrosequencing in a larger cohort. The expression status was analysed by quantitative polymerase chain reaction (PCR) and immunohistochemistry. We identified a CGI on a novel gene, RASSF1A, which was strongly hypermethylated in NET, but not in thymic carcinoma or B3 thymoma. RASSF1A was identified as a candidate gene statistically and bibliographically, as it showed frequent CGI hypermethylation in NET by genome-wide screening. Pyrosequencing confirmed significant hypermethylation of a RASSF1A CGI in NET. Low-grade NET tissue was more strongly methylated than high-grade NET. Quantitative PCR and immunohistochemical staining revealed that RASSF1A mRNA and protein expression levels were negatively regulated by DNA methylation. RASSF1A is a tumour suppressor gene epigenetically dysregulated in NET. Aberrant methylation of RASSF1A has been reported in various tumours, but this is the first report of RASSF1A hypermethylation in TETs. RASSF1A may represent an epigenetic therapeutic target in thymic NET. Copyright © 2017 Elsevier B.V. All rights reserved.

Review of thymic pathology in 30 cats and 36 dogs.

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Day, M J

1997-09-01

Data are presented from 30 cats and 36 dogs in which thymic disease was recognised clinically or on postmortem examination. The diagnoses included thymic lymphoma (19 cats, 12 dogs), thymoma (five cats, 18 dogs), thymic branchial cyst formation or cystic change (one cat, four dogs), thymic hyperplasia (two cats), congenital hypoplasia (one cat, one dog), thymic haemorrhage (one cat, one dog) and thymic amyloidosis (one cat). Thymic lymphoma occurred in younger dogs and cats, and was recorded equally among domestic shorthaired and purebred (especially Siamese) cats. Eight cats with thymic lymphoma were tested for feline leukaemia virus and four were positive. Thymoma occurred more frequently in older cats and dogs, and in Labradors and German shepherd dogs. Thymic tumours were associated with paraneoplastic hypercalcaemia (six dogs), megaoesophagus (two dogs) or interface dermatitis with basement membrane immune complex deposition (one cat). Non-neoplastic thymic diseases were associated with myasthenia gravis (one cat), pemphigus foliaceus (one cat) and superficial necrolytic dermatitis (one cat).

Development of Thymic Epithelial Cells

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Ulyanchenko, Svetlana; Vaidya, Harsh J.; O'Neill, Kathy E.

2016-01-01

The thymus is the primary lymphoid organ in which the T cell repertoire is generated. The complex cellularity of this organ is uniquely designed to facilitate T cell development: defects in thymus development or function can cause immunodeficiencies ranging from the absence of T cell-mediated imm......The thymus is the primary lymphoid organ in which the T cell repertoire is generated. The complex cellularity of this organ is uniquely designed to facilitate T cell development: defects in thymus development or function can cause immunodeficiencies ranging from the absence of T cell......-mediated immunity to broad-spectrum autoimmune disease. Peak thymus size and output occurs early in life, after which the thymus undergoes a natural process of involution. This results in the progressive loss of functional thymus tissue and correspondingly in decreased production of new naïve T cells with age...... - contributing to the diminished capacity of the aged immune system to adequately respond to new antigenic challenge. Age-related thymic involutions, together with the thymic involutions associated with cytotoxic therapies (e.g., radio- or chemotherapy), have raised interest in development of clinically useful...

The International Thymic Malignancy Interest Group thymic initiative: a state-of-the-art study of thymic malignancies.

Science.gov (United States)

Detterbeck, Frank; Korst, Robert

2014-01-01

Thymic malignancies are relatively rare tumors. A general lack of knowledge, misconceptions about benignancy, confusion about the definition of terms, and variability in reporting of outcomes have further hampered progress in these diseases. The International Thymic Malignancy Interest Group has emerged to counter these challenges and has brought together a worldwide multidisciplinary community determined to improve outcomes for these patients. Although the organization is young (initiated in 2010), major early accomplishments have created a foundation and infrastructure for scientific research. These include consensus definitions of terms, an unprecedented global database, development of practical clinical resources and, together with the International Association for the Study of Lung Cancer, development of proposals for the first formal stage classification of these malignant tumors. Many articles have been published or are under way, and a second phase of projects building on the early success is proceeding. The greatest accomplishment of the International Thymic Malignancy Interest Group lies in the establishment of an open culture of collaboration and the engagement of a broad group of individuals united by a common mission. It is a testament to what can be achieved, despite ongoing and inherent challenges, by determination and a collective effort. Copyright © 2014 Elsevier Inc. All rights reserved.

The effect of age on thymic function

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Donald B. Palmer

2013-10-01

Full Text Available Age-related regression of the thymus is associated with a decline in naïve T cell output. This is thought to contribute to the reduction in T cell diversity seen in older individuals and linked with increased susceptibility to infection, autoimmune disease and cancer. Thymic involution is one of the most dramatic and ubiquitous changes seen in the ageing immune system, but the mechanisms which underlying this process are poorly understood. However, a picture is emerging, implicating the involvement of both extrinsic and intrinsic factors. In this review we assess the role of the thymic microenvironment as a potential target that regulates thymic involution, question whether thymocyte development in the aged thymus is functionally impaired and explore the kinetics of thymic involution.

Doubling time of thymic epithelial tumours on CT: correlation with histological subtype

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Choe, Jooae; Lee, Sang Min; Kim, Namkug; Do, Kyung-Hyun; Seo, Joon Beom [University of Ulsan College of Medicine, Department of Radiology and Research Institute of Radiology, Songpa-gu, Seoul (Korea, Republic of); Lim, Soyeoun [Ulsan University Hospital, Department of Radiology, University of Ulsan College of Medicine, Ulsan (Korea, Republic of); Choi, Se Hoon [University of Ulsan College of Medicine, Department of Thoracic and Cardiovascular Surgery, Seoul (Korea, Republic of)

2017-10-15

We retrospectively evaluated the doubling time (DT) of thymic epithelial tumours (TET) according to the histological subtype on CT. From January 2005 to June 2016, we enrolled 53 patients who had pathologically confirmed TET and at least two CT scans. Tumour size was measured using a two-dimensional method, and the DT was calculated. DTs were compared among histological subtypes, and factors associated with rapid tumour growth (DT <180 days) were assessed. In 42 of the 53 patients (79.2%) the tumours showed interval growth (>2 mm) during follow-up. The median DT for all tumours was 400 days (range 48-1,964 days). There were no significant differences in DT in relation to histological subtype (p = 0.177). When TETs were recategorized into three groups, i.e. low-risk thymomas (types A, AB, B1), high-risk thymomas (types B2, B3), and thymic carcinoma, DT was significantly different among the groups (median DT 436, 381 and 189 days, respectively; p = 0.031). Histological subtype (type B3 and thymic carcinoma) was the single independent predictor of rapid tumour growth. The majority of TETs grew during follow-up with variable and relatively slow growth rates. Histological features of aggressive behaviour significantly correlated with a decreased DT and rapid growth. circle The majority of thymic epithelial tumours grew during follow-up (79.2%, 42/53). (orig.)

Thymic involvement in immune recovery during antiretroviral treatment of HIV infection in adults; comparison of CT and sonographic findings

DEFF Research Database (Denmark)

Kolte, Lilian; Strandberg, Charlotte; Dreves, Anne-Mette

2002-01-01

In adult HIV-infected patients, thymic size evaluated from CT scans seems to be important to the degree of immune reconstitution obtainable during treatment with highly active antiretroviral therapy (HAART). To examine whether ultrasound is as reliable as CT for estimating thymic size...... and predicting immune recovery, CT and ultrasound scans were performed in 25 adult HIV-infected patients and 10 controls. CD4 counts and naive CD4 counts were measured in order to determine immune reconstitution. Furthermore, the CD4+ T-cell receptor excision circle (TREC) frequency and T-cell receptor (TCR...

Rag defects and thymic stroma: lessons from animal models

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Veronica eMarrella

2014-06-01

Full Text Available Thymocytes and thymic epithelial cells (TECs cross-talk is essential to support T-cell development and preserve thymic architecture and maturation of TECs and Foxp3+ natural regulatory T (nTreg cells. Accordingly, disruption of thymic lymphostromal cross-talk may have major implications on the thymic mechanisms that govern T cell tolerance. Several genetic defects have been described in humans that affect early stages of T cell development (leading to Severe Combined Immune Deficiency, SCID or late stages in thymocyte maturation (resulting in combined immunodeficiency. Hypomorphic mutations in SCID-causing genes may allow for generation of a limited pool of T lymphocytes with a restricted repertoire. These conditions are often associated with infiltration of peripheral tissues by activated T cells and immune dysregulation, as best exemplified by Omenn syndrome (OS. In this review, we will discuss our recent findings on abnormalities of thymic microenvironment in OS with a special focus of defective maturation of TECs, altered distribution of thymic dendritic cells (DCs and impairment of deletional and non-deletional mechanisms of central tolerance. Here, taking advantage of mouse models of OS and atypical SCID, we will discuss how modifications in stromal compartment impact and shape lymphocyte differentiation, and vice versa how inefficient T cell signalling results in defective stromal maturation. These findings are instrumental to understand the extent to which novel therapeutic strategies should act on thymic stroma to achieve full immune reconstitution.

Thymic hyperplasia in Graves′ disease

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Narendra Kotwal

2013-01-01

Full Text Available Graves′ disease is an autoimmune thyroid condition characterized by the production of autoantibodies against the thyrotropin receptor. It is known to be associated with autoimmune conditions such as myasthenia gravis, Addison′s disease, type 1 diabetes mellitus, and vitiligo. We present a case of rare autoimmune association of Graves′ disease with thymic hyperplasia which regressed after treatment with antithyroid drugs. Exact pathophysiology of thymic hyperplasia in Graves′ is not well understood; it is likely to be the result of rather than the cause of Graves′ disease.

Administration of RANKL boosts thymic regeneration upon bone marrow transplantation.

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Lopes, Noella; Vachon, Hortense; Marie, Julien; Irla, Magali

2017-06-01

Cytoablative treatments lead to severe damages on thymic epithelial cells (TECs), which result in delayed de novo thymopoiesis and a prolonged period of T-cell immunodeficiency. Understanding the mechanisms that govern thymic regeneration is of paramount interest for the recovery of a functional immune system notably after bone marrow transplantation (BMT). Here, we show that RANK ligand (RANKL) is upregulated in CD4 + thymocytes and lymphoid tissue inducer (LTi) cells during the early phase of thymic regeneration. Importantly, whereas RANKL neutralization alters TEC recovery after irradiation, ex vivo RANKL administration during BMT boosts the regeneration of TEC subsets including thymic epithelial progenitor-enriched cells, thymus homing of lymphoid progenitors, and de novo thymopoiesis. RANKL increases specifically in LTi cells, lymphotoxin α, which is critical for thymic regeneration. RANKL treatment, dependent on lymphotoxin α, is beneficial upon BMT in young and aged individuals. This study thus indicates that RANKL may be clinically useful to improve T-cell function recovery after BMT by controlling multiple facets of thymic regeneration. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

Mutational status of EGFR and KIT in thymoma and thymic carcinoma.

Science.gov (United States)

Yoh, Kiyotaka; Nishiwaki, Yutaka; Ishii, Genichiro; Goto, Koichi; Kubota, Kaoru; Ohmatsu, Hironobu; Niho, Seiji; Nagai, Kanji; Saijo, Nagahiro

2008-12-01

This study was conducted to evaluate the prevalence of EGFR and KIT mutations in thymomas and thymic carcinomas as a means of exploring the potential for molecularly targeted therapy with tyrosine kinase inhibitors. Genomic DNA was isolated from 41 paraffin-embedded tumor samples obtained from 24 thymomas and 17 thymic carcinomas. EGFR exons 18, 19, and 21, and KIT exons 9, 11, 13, and 17, were analyzed for mutations by PCR and direct sequencing. Protein expression of EGFR and KIT was evaluated immunohistochemically. EGFR mutations were detected in 2 of 20 thymomas, but not in any of the thymic carcinomas. All of the EGFR mutations detected were missense mutations (L858R and G863D) in exon 21. EGFR protein was expressed in 71% of the thymomas and 53% of the thymic carcinomas. The mutational analysis of KIT revealed only a missense mutation (L576P) in exon 11 of one thymic carcinoma. KIT protein was expressed in 88% of the thymic carcinomas and 0% of the thymomas. The results of this study indicate that EGFR and KIT mutations in thymomas and thymic carcinomas are rare, but that many of the tumors express EGFR or KIT protein.

Minimally Invasive Surgery in Thymic Malignances

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Wentao FANG

2018-04-01

Full Text Available Surgery is the most important therapy for thymic malignances. The last decade has seen increasing adoption of minimally invasive surgery (MIS for thymectomy. MIS for early stage thymoma patients has been shown to yield similar oncological results while being helpful in minimize surgical trauma, improving postoperative recovery, and reduce incisional pain. Meanwhile, With the advance in surgical techniques, the patients with locally advanced thymic tumors, preoperative induction therapies or recurrent diseases, may also benefit from MIS in selected cases.

Thymic involvement in immune recovery during antiretroviral treatment of HIV infection in adults; comparison of CT and sonographic findings

DEFF Research Database (Denmark)

Kolte, Lilian; Strandberg, Charlotte; Dreves, Anne-Mette

2002-01-01

) repertoire were determined. The study demonstrated no correlation between the 2 scanning methods (r = 0.201, p = 0.358 in patients and r = 0.457, p = 0.184 in controls). Among the patients, no association was found between the sonographically estimated thymic size and immunological parameters such as CD4...... count (r = 0.083, p = 0.706), naive CD4 count (r = 0.067, p = 0.762), CD4 + TREC frequency (r = 0.028, p = 0.900) and CD4 + TCR repertoire (r = -0.057, p = 0.828). These findings show that CT remains superior for assessing thymic size in adults and is preferable to ultrasound when evaluating...

Association of murine lupus and thymic full-length endogenous retroviral expression maps to a bone marrow stem cell

International Nuclear Information System (INIS)

Krieg, A.M.; Gourley, M.F.; Steinberg, A.D.

1991-01-01

Recent studies of thymic gene expression in murine lupus have demonstrated 8.4-kb (full-length size) modified polytropic (Mpmv) endogenous retroviral RNA. In contrast, normal control mouse strains do not produce detectable amounts of such RNA in their thymuses. Prior studies have attributed a defect in experimental tolerance in murine lupus to a bone marrow stem cell rather than to the thymic epithelium; in contrast, infectious retroviral expression has been associated with the thymic epithelium, rather than with the bone marrow stem cell. The present study was designed to determine whether the abnormal Mpmv expression associated with murine lupus mapped to thymic epithelium or to a marrow precursor. Lethally irradiated control and lupus-prone mice were reconstituted with T cell depleted bone marrow; one month later their thymuses were studied for endogenous retroviral RNA and protein expression. Recipients of bone marrow from nonautoimmune donors expressed neither 8.4-kb Mpmv RNA nor surface MCF gp70 in their thymuses. In contrast, recipients of bone marrow from autoimmune NZB or BXSB donors expressed thymic 8.4-kb Mpmv RNA and mink cell focus-forming gp70. These studies demonstrate that lupus-associated 8.4-kb Mpmv endogenous retroviral expression is determined by bone marrow stem cells

The size of the thymus: an important immunological diagnostic tool?

DEFF Research Database (Denmark)

Jeppesen, Dorthe Lisbeth

2003-01-01

The report on the influence of seasonal factors on thymic size in early life describes a pattern of ultrasonographically measured thymic growth in Gambian infants including the finding of a smaller thymus in the hungry season. These factors raise a number of important questions: Is the size...

Thymic pathology and cardiac myxomas: Coincidence or a closer relationship?

Science.gov (United States)

Moraitis, Sotirios D; Agrafiotis, Apostolos C; Pappas, Dimitrios; Pothitakis, Chrysovalantis; Stergianni, Maria; Koukis, Ioannis

2018-04-30

Myxomas are the most common benign cardiac tumors and are located more frequently in the left atrium. In the literature there are cases describing the coexistence of thymic tumors and cardiac myxomas. In the case reported herein, during the resection of a cardiac myxoma, an enlarged thymus gland was encountered and resected. The histological exam revealed a thymic hyperplasia. The aim of this case study is to assess the need of conducting further studies in order to identify a common histological pathway between thymic lesions and cardiac myxomas. The diagnosis of a cardiac myxoma could justify a further workup of the anterior mediastinum in order not to overlook a lesion of thymic origin.

Detection of chemotherapy-induced thymic changes in patients with metastasised testicular tumors by computed tomography

International Nuclear Information System (INIS)

Hendrickx, P.; Doehring, W.

1989-01-01

Serial thoracic CT scans of 100 patients suffering from testicular cancer revealed that the thymus appears to atrophy temporarily during administration of cytostatic agents. About two months after cessation of chemotherapy rebound enlargement of the thymus occurs and persists for about two years followed by a slow involution. Using a semiquantitative score system, thymic CT images of these patients were compared with that of 100 patients suffering from other malignancies, 100 patients without malignant disease and 52 patients with myasthenia gravis, taking into account the age-related changes of the size of the organ. Rebound thymic enlargement should not be misinterpreted as metastatic lymph nodes. (orig.) [de

Detection of chemotherapy-induced thymic changes in patients with metastasised testicular tumors by computed tomography

Energy Technology Data Exchange (ETDEWEB)

Hendrickx, P.; Doehring, W.

1989-03-01

Serial thoracic CT scans of 100 patients suffering from testicular cancer revealed that the thymus appears to atrophy temporarily during administration of cytostatic agents. About two months after cessation of chemotherapy rebound enlargement of the thymus occurs and persists for about two years followed by a slow involution. Using a semiquantitative score system, thymic CT images of these patients were compared with that of 100 patients suffering from other malignancies, 100 patients without malignant disease and 52 patients with myasthenia gravis, taking into account the age-related changes of the size of the organ. Rebound thymic enlargement should not be misinterpreted as metastatic lymph nodes.

Juvenile exposure to predator cues induces a larger egg size in fish

Science.gov (United States)

Segers, Francisca H. I. D.; Taborsky, Barbara

2012-01-01

When females anticipate a hazardous environment for their offspring, they can increase offspring survival by producing larger young. Early environmental experience determines egg size in different animal taxa. We predicted that a higher perceived predation risk by juveniles would cause an increase in the sizes of eggs that they produce as adults. To test this, we exposed juveniles of the mouthbrooding cichlid Eretmodus cyanostictus in a split-brood experiment either to cues of a natural predator or to a control situation. After maturation, females that had been confronted with predators produced heavier eggs, whereas clutch size itself was not affected by the treatment. This effect cannot be explained by a differential female body size because the predator treatment did not influence growth trajectories. The observed increase of egg mass is likely to be adaptive, as heavier eggs gave rise to larger young and in fish, juvenile predation risk drops sharply with increasing body size. This study provides the first evidence that predator cues perceived by females early in life positively affect egg mass, suggesting that these cues allow her to predict the predation risk for her offspring. PMID:21976689

Immune activation is associated with decreased thymic function in ...

African Journals Online (AJOL)

Background: Reduced thymic function causes poor immunological reconstitution in human immunodeficiency virus (HIV)-positive patients on combined antiretroviral therapy (cART). The association between immune activation and thymic function in asymptomatic HIVpositive treatment-naive individuals has thus far not been ...

Preoperative CT prediction for Masaoka staging of thymic epithelial tumor

International Nuclear Information System (INIS)

Feng Zhan; Huang Zhen; Zhang Liang

2013-01-01

Objective: To discuss the value of CT prognosis on the Masaoka staging system of thymic epithelial tumors (TET) before surgical resection. Methods: The CT images of 102 patients with TET proved by surgery and pathology were reviewed retrospectively. The TET were reclassified according to Masaoka stage system. The size, homogeneity, sharp, contour, infiltration of surrounding tissue, and metastasis on CT were analyzed with Logistic analysis. The diagnostic value was also evaluated with a ROC curve. Results: Masaoka pathologic stages were stage Ⅰ for 36 (35.3 %), stage Ⅱ for 27 (26.5 %), stage Ⅲ for 30 (29.4 %), and stage Ⅳ for 9 (8.8 %). A multivariable Logistic regression model showed that TET with larger size of tumor (20/35, P = 0.0371, OR = 4.539), irregular or lobulated tumor contour (26/42, P = 0.0230, OR = 4.870), heterogeneous (21/33, P = 0.0154, OR = 6.020), infiltration of surrounding fat (25/32, P = 0.0019, OR = 14.005), and pleural seeding (11/11, P = 0.0032, OR = 36.153) were more likely to have stage Ⅲ or Ⅳ disease. The area under ROC curve was 0.940. Conclusions: The tumor CT imaging features can differentiate between stage Ⅰ, Ⅱ and stage Ⅲ, Ⅳ disease. This helps identified patients more likely to benefit from neoadjuvant therapy. (authors)

Thymic B cell development is controlled by the B potential of progenitors via both hematopoietic-intrinsic and thymic microenvironment-intrinsic regulatory mechanisms.

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Shiyun Xiao

Full Text Available Hematopoietic stem cells (HSCs derived from birth through adult possess differing differentiation potential for T or B cell fate in the thymus; neonatal bone marrow (BM cells also have a higher potential for B cell production in BM compared to adult HSCs. We hypothesized that this hematopoietic-intrinsic B potential might also regulate B cell development in the thymus during ontogeny.Foxn1lacZ mutant mice are a model in which down regulation of a thymic epithelial cell (TEC specific transcription factor beginning one week postnatal causes a dramatic reduction of thymocytes production. In this study, we found that while T cells were decreased, the frequency of thymic B cells was greatly increased in these mutants in the perinatal period. We used this model to characterize the mechanisms in the thymus controlling B cell development.Foxn1lacZ mutants, T cell committed intrathymic progenitors (DN1a,b were progressively reduced beginning one week after birth, while thymic B cells peaked at 3-4 weeks with pre-B-II progenitor phenotype, and originated in the thymus. Heterochronic chimeras showed that the capacity for thymic B cell production was due to a combination of higher B potential of neonatal HSCs, combined with a thymic microenvironment deficiency including reduction of DL4 and increase of IL-7 that promoted B cell fate.Our findings indicate that the capacity and time course for thymic B-cell production are primarily controlled by the hematopoietic-intrinsic potential for B cells themselves during ontogeny, but that signals from TECs microenvironment also influence the frequency and differentiation potential of B cell development in the thymus.

Evaluation of thymic tumors with 18F-FDG PET-CT - A pictorial review

International Nuclear Information System (INIS)

Sharma, Punit; Singhal, Abhinav; Bal, Chandrasekhar; Malhotra, Arun; Kumar, Rakesh; Kumar, Arvind

2013-01-01

Thymic tumors represent a broad spectrum of neoplastic disorders and pose considerable diagnostic difficulties. A non-invasive imaging study to determine the nature of thymic lesions can have significant impact on management of such tumors. 18F-flurorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) has shown promising results in characterization of thymic tumors. The objective of this article is to provide an illustrative tutorial highlighting the clinical utility of 18F-FDG PET-CT imaging in patients with thymic tumors. We have pictorially depicted the 18F-FDG PET-CT salient imaging characteristics of various thymic tumors, both epithelial and non-epithelial. Also discussed is the dynamic physiology of thymus gland which is to be kept in mind when evaluating thymic pathology on 18F-FDG PET-CT, as it can lead to interpretative pitfalls

Size selectivity of commercial (300 MC) and larger square mesh top ...

African Journals Online (AJOL)

In the present study, size selectivity of a commercial (300 MC) and a larger square mesh top panel (LSMTPC) codend for blue whiting (Micromesistius poutassou) were tested on a commercial trawl net in the international waters between Turkey and Greece. Trawling, performed during daylight was carried out at depths ...

Correlation between the CT manifestations and post-operative survival time in patients with thymic epithelial tumor

International Nuclear Information System (INIS)

Chen Juan; Tan Ye; Wang Xiangyang; Du Jun; Pan Jishu; Wei Jiahu

2011-01-01

Objective: To describe the CT manifestations of thymic epithelial tumor and explore the correlation between CT findings and post-operative tumor-related survival time. Methods: Ninety-one patients who underwent CT scan before operation were reviewed retrospectively. All cases had operation and were classified according to the WHO classification. The size, contour, shape, density and enhancement of the tumors on CT were assessed. Presence of mediastinal lymphadenopathy, great vessel invasion, metastasis to the lung or plural, myasthenia gravis (MG) were also analyzed. The survival rate was obtained using, the Kaplan-Meier method. The Cox model was applied to determine the factors affecting the tumor-related survivals. Chi square test was used to analyze the relationship between CT findings and WHO classification. Results: Two patients were excluded because of dying of myocardial infarction and colon cancer. The total 5-year survival rate was 84.3% (n=75). Eighty-nine patients had total 91 tumors. Tumors with diameter larger than 5 cm, lobular contour, heterogenous density, and presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis were adverse factors which could significantly affect the survival time. Five-year survival rates of these factors were 72.7%, 77.3%, 76.7%, 73.8%, 30.0%, and 68.8%, respectively. Presence of MG was a favorable factor which also significantly affected the survival time (P 0.05). The result of the Cox multivariate analysis was consistent with that of the Log-rank test. For different WHO classification, there were significant different among the size or contour of the tumors, presence of great vessel invasion, mediastinal lymphadenopathy, and metastasis (χ 2 value were 6.598, 5.737, 18.307, 8.465, and 15.608, respectively P<0.05). Conclusions: CT findings may be served as predictors of clinical prognosis of the thymic epithelial tumors. Adverse factors for survival time are the size of the tumors and presence of

Ectopic Thymic Cyst of the Subglottis: Considerations for Diagnosis and Management.

Science.gov (United States)

Ahmad, Iram; Kirby, Patricia; Liming, Bryan

2018-03-01

To share the diagnostic and management challenges created by an extremely rare airway lesion-the subglottic ectopic thymic cyst. Case report and literature review. We review the presentation, management, and clinical course of an infant who presented with a subglottic mass that was histologically confirmed as a thymic cyst. A brief literature review supplements the case presentation Results: We present the third described case of an ectopic thymic cyst presenting as a subglottic mass. The differential diagnosis of subglottic masses in neonates consists primarily of subglottic hemangioma and mucous retention cysts. Otolaryngologists must be prepared for unexpected findings when dealing with critical airways. We compare the presentation and management of our patient with the 2 previously described cases. We propose an embryologic theory for the origin of these rare lesions. An ectopic thymic cyst is a rare and unexpected cause of neonatal stridor. Management of pediatric airway lesions must allow for unexpected findings at the time of diagnostic and therapeutic endoscopy. The appropriate management of subglottic thymic cysts is poorly defined, but close surveillance for recurrence is mandatory.

Radiation-induced quantitative alterations in prenatal thymic development in the beagle dog

International Nuclear Information System (INIS)

Miller, G.K.; Benjamin, S.A.

1985-01-01

Quantitative morphology of the canine fetal thymus was studied to evaluate the age-dependent radiosensitivity of the developing immune system. Pregnant beagle dams received abdominal 60 Co gamma exposures (200 R) or were sham irradiated at one of three ages in gestation, 30, 40, or 45 days. The mean calculated dose to each fetus was 1.5 Gray. One-half of the fetuses in each litter were harvested by hysterotomy at 5 days and one-half at 10 days post-irradiation (PI). The volumes of the thymic lobules and lobular cortices were significantly reduced at 5 and 10 days PI when compared with age-matched controls. Thymic cortical volumes in irradiated fetuses were reduced between 13 and 29% from control volumes by 5 days PI and 8 and 13% by 10 day PI. Thymic medullary volumes in irradiated fetuses were reduced 18 to 23% by 5 days PI and 27 to 54% by 10 days PI. The reductions in medullary volumes in fetuses irradiated at 35, 40, and 45 days of gestation and evaluated at 10 days PI were 54, 38, and 27%, respectively. Although injury to both thymic cortices and medullas was greater following exposures earlier in gestation, damage to medullas was relatively more severe than in cortices following exposure at any one age. The degree of reduction of medullary volume reflects thymic epithelial injury and is surprising since thymic epithelium is considered to be radioresistant in the adult. Such injury may have serious consequences postnatally as normal differentiation of T cell subpopulations is dependent upon the integrity of the thymic microenvironment. Damage to the thymic microenvironment could result in defects in immunologic regulation and in immune deficiencies

Thymic epithelial tumours: from basic principles to individualised treatment strategies

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Nicolas Girard

2013-03-01

Full Text Available Thymic epithelial tumours represent a wide range of anatomical, clinical, histological and molecular malignant entities that may be aggressive and difficult to treat. The histopathological classification distinguishes thymomas from thymic carcinomas. Thymomas may be associated with autoimmune disorders. The management of thymic epithelial tumours is a paradigm of co-operation between clinicians, surgeons and pathologists, from establishing the diagnosis to organising the multimodal therapeutic strategy. Surgery is the mainstay of the curative-intent treatment, as complete resection represents the most significantly favourable prognostic factor on overall survival. In case of invasion of intra-thoracic structures and/or dissemination to the pleura and the pericardium, precluding complete resection to be achieved, primary chemotherapy has been used to reduce the tumour burden, possibly allowing subsequent surgery and/or radiotherapy. Novel strategies are needed, especially for refractory, recurrent tumours and thymic carcinomas, which carry a poor prognosis. Personalised approaches are currently being developed, as potentially “druggable” molecular targets are emerging from recent integrated genomic analyses. Along with the large variety of questions relative to the treatment strategy, thymic epithelial tumours represent a model of therapeutic implementation and achievement in orphan thoracic oncology, showing how the advent of new results induces new questions, as well as diversifies further clinical research directions and international collaborative initiatives.

Thymic nurse cells and thymic repopulation after whole body sublethal irradiation in mice

International Nuclear Information System (INIS)

Houben-Defresne, M.P.; Varlet, A.; Boniver, J.

1984-01-01

Thymic Nurse Cells (TNCs) are lymphoepithelial complexes which are thought to play a role in the early stages of the intrathymic differentiation pathway. Their repopulation kinetics were analyzed in mice after sublethal whole-body irradiation. Changes of the number of TNCs per thymus were parallel with the evolution of the whole thymocyte population. Particularly, a first wave of TNCs restoration was followed by a secondary depletion and a final recovery. This suggests that TNCs restoration is related to the proliferating progeny of intrathymic radioresistant thymocytes. When normal bone marrow cells were grafted intravenously after irradiation, no secondary depletion was found. This pattern of restoration was obviously related to thymic repopulation by cells which were derived from the inoculated bone marrow. Homing studies with FITC labelled bone marrow cells showed that inoculated bone marrow cells did not penetrate TNCs early after irradiation. Later on, when immigrant cells started to proliferate, they were found preferentially within TNCs before spreading in the whole thymus. (Auth.)

Optimal surgical approach to thymic malignancies: New trends challenging old dogmas.

Science.gov (United States)

Ruffini, Enrico; Filosso, Pier Luigi; Guerrera, Francesco; Lausi, Paolo; Lyberis, Paraskevas; Oliaro, Alberto

2018-04-01

Until recently, the surgical approach to thymic tumors has remained basically unchanged. The collaborative effort led by ITMIG with the collaboration of regional and society-based interest groups (ESTS, JART) produced an enthusiastic surge of interest in testing the new technological advances in thoracic surgery and many historical dogmas in thymic surgery have been questioned and challenged. The present review addresses the new trends in the optimal surgical management of thymic tumors based on the review of the current literature. 1. Minimally-invasive techniques (MIT) including video-assisted thoracic surgery (VATS) and robotic-assisted thoracic Surgery (RATS) are now to be considered the standard of care in early-stage thymic tumors. MIT are no inferior to open approaches in terms of postoperative complications, loco-regional recurrence rates and survival. MIT are associated with a shorter length of stay, reduced intraoperative blood loss and better cosmetic results. 2. The adoption of the ITMIG/IASLC TNM staging system for thymic tumors requires a paradigm shift among thoracic surgeons to include regional lymphadenectomy according to the IASLC/ITMIG nodal map in the surgical management of thymic tumors. 3. A limited thymectomy instead of total thymectomy along with the removal of the thymic tumor in nonmyasthenic Stage I-II tumors has been proposed by some authors, although the results are not uniform. Until more mature data is available, adherence to the current guidelines recommending total thymectomy in addition to thymomectomy is always indicated. 4. In locally-advanced Stage IVa patients with pleural involvement, major pleural resections, including pleurectomy/decortication or extrapleural pneumonectomy are indicated, provided a complete resection of the pleural deposits is anticipated, usually in a multidisciplinary setting, with excellent long-term results. The incorporation of these new concepts and techniques in the surgical armamentarium of the

LAT1 acts as a crucial transporter of amino acids in human thymic carcinoma cells

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Keitaro Hayashi

2016-11-01

Full Text Available L-type amino acid transporter 1 (LAT1, SLC7A5 incorporates essential amino acids into cells. Recent studies have shown that LAT1 is a predominant transporter in various human cancers. However, the function of LAT1 in thymic carcinoma remains unknown. Here we demonstrate that LAT1 is a critical transporter for human thymic carcinoma cells. LAT1 was strongly expressed in human thymic carcinoma tissues. LAT1-specific inhibitor significantly suppressed leucine uptake and growth of Ty82 human thymic carcinoma cell lines, suggesting that thymic carcinoma takes advantage of LAT1 as a quality transporter and that LAT1-specific inhibitor might be clinically beneficial in therapy for thymic carcinoma.

Effects of the thymic microenvironment on autoantibody production in (NZB X NZW)F1 mice

International Nuclear Information System (INIS)

Huston, D.P.; Smathers, P.A.; Reeves, J.P.; Steinberg, A.D.

1983-01-01

The effects of the thymic microenvironment on autoantibody production in (NZB X NZW)F1 mice were studied. Neonatally thymectomized male and female F1 mice reconstituted with a parental or F1-irradiated thymic lobe were compared to nonreconstituted and sham-thymectomized controls. While maleness retarded the spontaneous production of ss- and ds-DNA antibodies, thymic grafts did not suppress antibodies to ss-DNA in either sex, but did suppress the production of antibodies to ds-DNA in female mice. A unique property of NZB thymic grafts was the inability to suppress anti-RBC antibodies in male mice. Thus, (i) the gender of the F1 recipient was the most important determinant of production of antibodies to ss-DNA, (ii) either maleness or the thymic microenvironment could retard production of anti-ds-DNA antibodies, and (iii) both gender and the thymic microenvironment were important in the regulation of anti-RBC antibody production. Since the administration of thymosin did not suppress autoantibody production, the effects of the thymic grafts was not solely via thymic hormone production. These studies suggest that sex hormones and/or the thymic microenvironment can exert a suppressive effect on autoantibody production and that autoantibodies differ in their susceptibility to such suppression

Intrapericardial primary thymic carcinoma in a 73-year-old man.

Science.gov (United States)

Calderon, Ana Maria; Merchan, Juan Andres; Rozo, Juan Carlos; Guerrero, Cesar Ivan; Treistman, Bernardo; Sulak, Laura E; Cheong, Benjamin Y C; Rodríguez, German; Mesa, Andrés

2008-01-01

Thymic carcinoma is a rare, highly aggressive type of tumor that typically occurs in the anterior mediastinum. We describe the case of a 73-year-old man who presented with weakness, cough, dyspnea, anorexia, and weight loss. An echocardiogram showed an intrapericardial mass that occupied the space around the lateral walls of the left ventricle and distally compressed the right ventricle. Magnetic resonance imaging and a biopsy confirmed the presence of intrapericardial primary thymic carcinoma. The patient underwent surgical excision of the tumor and died of right ventricular rupture during the procedure. This case highlights the importance of considering thymic carcinoma whenever an otherwise unexplained intrapericardial mass is encountered.

Fate of thymic radioactivity after local labeling with 125Iododeoxyuridine

International Nuclear Information System (INIS)

Laissue, J.A.; Chanana, A.D.; Cottier, H.; Cronkite, E.P.; Joel, D.D.

1976-01-01

The thymic cortex was locally labeled with 125 Iododeoxyuridine ( 125 IUdR) in young adult mice in an attempt to provide a simple quantitative assessment of the fate of cortical thymocytes. Similarly operated and nonoperated mice given 125 IUdR intravenously were used for comparison. Analogous experiments were performed in adrenalectomized animals. More than 90 percent of thymic activity present 1 day after labeling had been lost by day 8. That proportion of radioactivity contributed to a given organ by accumulation of labeled thymic migrants was estimated by comparison of values obtained after local labeling with those acquired after systemic labeling. Thymic cell accumulation was apparent in the intestine, spleen, mesenteric lymph node, and femurs of locally labeled mice; however, only a few percent of the total activity lost from the thymus was accounted for in these lymphoid organs. The pattern of fecal and urinary elimination of 125 I did not markedly differ in the various experimental groups, the bulk of the activity being recovered in the urine. The intestine could not be ruled out as a major site of thymocyte loss. Since significant radiation or pharmacologic toxicity was unlikely with the doses of 125 IUdR used, the data indicated that the vast majority of newly formed thymocytes dies after a short life and only a small fraction of thymic migrants is longer lived

Bioprocessing feasibility analysis. [thymic hormone bioassay and electrophoresis

Science.gov (United States)

1978-01-01

The biology and pathophysiology of the thymus gland is discussed and a clinical procedure for thymic hormone assay is described. The separation of null lymphocytes from mice spleens and the functional characteristics of the cells after storage and transportation were investigated to develop a clinical procedure for thymic hormone assay, and to determine whether a ground-based approach will provide the desired end-product in sufficient quantities, or whether the microgravity of space should be exploited for more economical preparation of the hormone.

Flt3 ligand-receptor interaction is important for maintenance of early thymic progenitor numbers in steady-state thymopoiesis.

Science.gov (United States)

Kenins, Linda; Gill, Jason W; Holländer, Georg A; Wodnar-Filipowicz, Aleksandra

2010-01-01

T-cell production throughout life depends on efficient colonization and intrathymic expansion of BM-derived hematopoietic precursors. After irradiation-induced thymic damage, thymic recovery is facilitated by Flt3 ligand (FL), expressed by perivascular fibroblasts surrounding the thymic entry site of Flt3 receptor-positive progenitor cells. Whether intrathymic FL-Flt3 interactions play a role in steady-state replenishment of T cells remains unknown. Here, using competitive BM transplantation studies and fetal thymic organ cultures we demonstrated the continued numerical advantage of Flt3+ intrathymic T-cell precursors. Sub-kidney capsule thymic transplantation experiments, in which WT and FL-/- thymic lobes were grafted into FL-/- recipients, revealed that FL expression by the thymic microenvironment plays a role in steady-state thymopoiesis. The deficiency of the most immature thymic T-cell precursors correlated to upregulation of FL by thymic MTS15+ fibroblasts, suggesting that the number of Flt3+ progenitor cells may regulate the thymic expression of this cytokine. Together, these results show that FL expression by thymic stromal fibroblasts interacting with Flt3+ T-cell progenitors is important for the physiological maintenance of early T-cell development.

The diagnosis of thymoma and thymic atrophy in patients with myasthenia gravis

International Nuclear Information System (INIS)

Sund, K.K.; Skeie, G.O.; Gilhus, N.E.; Aarli, J.A.; Varhaug, J.E.

1997-01-01

The authors have compared clinical, immunological and radiological data in 20 patients with myasthenia gravis and thymoma and in 21 patients with myasthenia gravis and thymic atrophy. The median age at onset was 54 years in the thymoma group and 63 years in the thymic atrophy group. The severity of the disease was similar in the two groups, and there was no significant difference in the concentration of acetylcholine receptor antibodies. CA antibodies were demonstrated in 17/20 thymoma patients and in 6/21 with thymic atrophy, while 19/20 thymoma patients had antibodies to titin, compared with 9/21 among those with thymic atrophy. The diagnosis and treatment of patients with myasthenia gravis is based upon an evaluation of clinical, immunological and radiological data. 28 refs., 2 tabs

Thymic hyperplasia - clinical course and imaging diagnostic

International Nuclear Information System (INIS)

Drebov, R.; Panov, M.; Totev, M.; Deliverski, T.; Tcandev, I.; Velkovski, I.

2006-01-01

The real thymic hyperplasia is benign disease sometimes simulating malignant tumours. The aim of this study is to analyse the clinical symptoms of real thymic hyperplasia and the results from imaging diagnostic based on our clinical material. Clinical material include 27 children, aged from two months to 15 years, admitted in department of thoracic surgery, for a period of 20 years (1985 - 2004). We retrospectively analyze the clinical signs and results from X-ray investigation, CT (Siemens Somatom DRG and Philips Secura) and echocardiography (Acuson TX, 5 and 7 MHz). We discuss the diagnostic value of different methods as well as typical and atypical findings. (authors)

Effect of allogenic thymic cells on radioleukaemogenesis in AKR-T1ALD mice

International Nuclear Information System (INIS)

Legrand, E.; Sankar-Mistry, P.; Kressmann, M.C.

1975-01-01

When AKR mice are irradiated with a sub-lethal dose (4 times 175 R), thymic lymphosarcomas (L.S.) occur earlier than in controls. This accelerated leukaemogenesis is not inhibited by syngenic restoration with bone marrows cells (BM). Using the AKR/T1ALD substrain which bears 38 chromosomes with 1 metacentric markers, it has been shown that AKR radio-chimaeras restored by T1ALD BM developed two kinds of L.S.: early (radiation-induced) L.S. originating mainly from host cells surviving irradiation and late L.S. from donor cells. The experiments were to investigate the potential influence of normal allogenic thymic cells, with or without syngenic B.M., on the incidence, latency and origin of LS appearing in irradiated AKR recipients. Adding C3H allogenic thymic cells to syngenic B.M. increases the percentage of early L.S. whose latencies are unchanged. Besides, when C3H thymic cells are injected to irradiated controls without syngenic B.M. cells, L.S. are seen to occur significantly earlier than in just the irradiated animals alone. In radio-chimaeras restored by allogenic thymic cells and syngenic B.M., except in one case, all the L.S. were seen to originate from B.M. cells. The interpretation of these results depends on the possible role of allogenic thymic cells on host cells surviving the irradiation, or the exogeneous B.M. In the first case, allogenic thymocytes could induce a graft versus host reaction increasing the post-irradiation depletion of lymphoid system and hastening thymic endoregeneration which is supposed to be the first step towards leukaemogenesis. The second hypothesis, which seems the most likely, would be that C1H thymic cells could selectively act on host cells surviving irradiation and enhance the differenciation of haemopoietic precursors at the expense of the lymphoid cells [fr

Radiation carcinogenesis in mouse thymic lymphomas

International Nuclear Information System (INIS)

Kominami, Ryo; Niwa, Ohtsura

2006-01-01

Ionizing radiation is a well-known carcinogen for various human tissues and a complete carcinogen that is able to initiate and promote neoplastic progression. Studies of radiation-induced mouse thymic lymphomas, one of the classic models in radiation carcinogenesis, demonstrated that even the unirradiated thymus is capable of developing into full malignancy when transplanted into the kidney capsule or subcutaneous tissue of irradiated mice. This suggests that radiation targets tissues other than thymocytes to allow expansion of cells with tumorigenic potential in the thymus. The idea is regarded as the ''indirect mechanism'' for tumor development. This paper reviews the indirect mechanism and genes affecting the development of thymic lymphomas that we have analyzed. One is the Bcl11b/Rit1 tumor suppressor gene and the other is Mtf-1 gene affecting tumor susceptibility. (author)

Larger ATV engine size correlates with an increased rate of traumatic brain injury.

Science.gov (United States)

Butts, C Caleb; Rostas, Jack W; Lee, Y L; Gonzalez, Richard P; Brevard, Sidney B; Frotan, M Amin; Ahmed, Naveed; Simmons, Jon D

2015-04-01

Since the introduction of all-terrain vehicles (ATV) to the United States in 1971, injuries and mortalities related to their use have increased significantly. Furthermore, these vehicles have become larger and more powerful. As there are no helmet requirements or limitations on engine-size in the State of Alabama, we hypothesised that larger engine size would correlate with an increased incidence of traumatic brain injury (TBI) in patients following an ATV crash. Patient and ATV data were prospectively collected on all ATV crashes presenting to a level one trauma centre from September 2010 to May 2013. Collected data included: demographics, age of driver, ATV engine size, presence of helmet, injuries, and outcomes. The data were grouped according to the ATV engine size in cubic centimetres (cc). For the purposes of this study, TBI was defined as any type of intracranial haemorrhage on the initial computed tomography scan. There were 61 patients identified during the study period. Two patients (3%) were wearing a helmet at the time of injury. Patients on an ATV with an engine size of 350 cc or greater had higher Injury Severity Scores (13.9 vs. 7.5, p ≤ 0.05) and an increased incidence of TBI (26% vs. 0%, p ≤ 0.05) when compared to patients on ATV's with an engine size less than 350 cc. Patients on an ATV with an engine size of 350 cc or greater were more likely to have a TBI. The use of a helmet was rarely present in this cohort. Legislative efforts to implement rider protection laws for ATVs are warranted. Copyright © 2014 Elsevier Ltd. All rights reserved.

HIV-infected patients with a large thymus maintain higher CD4 counts in a 5-year follow-up study of patients treated with highly active antiretroviral therapy

DEFF Research Database (Denmark)

Kolte, L; Ryder, L P; Albrecht-Beste, E

2009-01-01

output determined as the number of CD4 + cells containing T-cell receptor-rearrangement excision DNA circles were measured prospectively in 25 HIV-infected patients with known thymic size during 5 years of HAART. Patients with larger thymic size had at all time points of follow-up significantly higher CD...

Clinical analysis of thymic regrowth following chemotherapy in children and adolescents with malignant lymphoma

International Nuclear Information System (INIS)

Zhen Zijun; Sun Xiaofei; Xia Yi; Ling Jiayu; Cai Yue; Wang Juan; Guan Zhongzhen

2010-01-01

Thymic regrowth following chemotherapy has typical clinical and imaging manifestations that can be used to diagnose it prior to pathological diagnosis. We investigated methods for diagnosing thymic regrowth following chemotherapy with non-invasive methods. Our study included 26 children and adolescents with thymic regrowth following chemotherapy for malignant lymphoma. Computed tomography scans were routinely performed for follow-up observations. After the emergence of new mediastinal masses, patients either underwent Fluorine-18 fluorodeoxyglucose-positron emission tomography scans to identify the characteristics of the mass, or were closely followed up. Thymic regrowth occurred 1-12 months after the last chemotherapy (mean, 4 months). Computed tomography mostly revealed diffusely enlarged thymic parenchymatous tissues that maintained normal thymic morphology. Computed tomography values were 36.72±9.48 Hu and increased by 5.56±2.62 Hu in contrast enhancement. The mean volume of the mass was 19.2 cm 3 . Twenty patients underwent positron emission tomography; among them, five (25%) showed no intake of Fluorine-18 fluorodeoxyglucose in the anterior mediastinal mass, and 15 (75%) showed radioactivity distribution in the mass with a mean standardized uptake value of 2.7; the shape was regular and radioactivity distribution was uniform. The mean follow-up duration was 40 months and all patients achieved disease-free survival. In the absence of pathological diagnosis, thymic regrowth following chemotherapy can be diagnosed by clinical features combined with characteristic manifestations in computed tomography and positron emission tomography scans. (author)

Anti-apoptotic signature in thymic squamous cell carcinomas – functional relevance of anti-apoptotic BIRC3 expression in the thymic carcinoma cell line 1889c

OpenAIRE

Huang, Bei; Belharazem, Djeda; Li, Li; Kneitz, Susanne; Schnabel, Philipp A.; Rieker, Ralf J.; Körner, Daniel; Nix, Wilfried; Schalke, Berthold; Müller-Hermelink, Hans Konrad; Ott, German; Rosenwald, Andreas; Ströbel, Philipp; Marx, Alexander

2016-01-01

The molecular pathogenesis of thymomas and thymic carcinomas (TCs) is poorly understood and results of adjuvant therapy are unsatisfactory in case of metastatic disease and tumor recurrence. For these clinical settings, novel therapeutic strategies are urgently needed. Recently, limited sequencing efforts revealed that a broad spectrum of genes that play key roles in various common cancers are rarely affected in thymomas and thymic carcinomas, suggesting that other oncogenic principles might ...

The Wnt Signaling Antagonist Kremen1 is Required for Development of Thymic Architecture

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Masako Osada

2006-01-01

Full Text Available Wnt signaling has been reported to regulate thymocyte proliferation and selection at several stages during T cell ontogeny, as well as the expression of FoxN1 in thymic epithelial cells (TECs. Kremen1 (Krm1 is a negative regulator of the canonical Wnt signaling pathway, and functions together with the secreted Wnt inhibitor Dickkopf (Dkk by competing for the lipoprotein receptor-related protein (LRP-6 co-receptor for Wnts. Here krm1 knockout mice were used to examine krm1 expression in the thymus and its function in thymocyte and TEC development. krm1 expression was detected in both cortical and medullary TEC subsets, as well as in immature thymocyte subsets, beginning at the CD25+CD44+ (DN2 stage and continuing until the CD4+CD8+(DP stage. Neonatal mice show elevated expression of krm1 in all TEC subsets. krm1− / − mice exhibit a severe defect in thymic cortical architecture, including large epithelial free regions. Much of the epithelial component remains at an immature Keratin 5+ (K5 Keratin 8+(K8 stage, with a loss of defined cortical and medullary regions. A TOPFlash assay revealed a 2-fold increase in canonical Wnt signaling in TEC lines derived from krm1− / − mice, when compared with krm1+ / + derived TEC lines. Fluorescence activated cell sorting (FACS analysis of dissociated thymus revealed a reduced frequency of both cortical (BP1+EpCAM+ and medullary (UEA-1+ EpCAMhi epithelial subsets, within the krm1− / − thymus. Surprisingly, no change in thymus size, total thymocyte number or the frequency of thymocyte subsets was detected in krm1− / − mice. However, our data suggest that a loss of Krm1 leads to a severe defect in thymic architecture. Taken together, this study revealed a new role for Krm1 in proper development of thymic epithelium.

Evidence That Androgens Modulate Human Thymic T Cell Output

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Olsen, Nancy J.; Kovacs, William J.

2010-01-01

Background The thymus has long been recognized as a target for the actions of androgenic hormones, but it has only been recently recognized that alterations in circulating levels of gonadal steroids might affect thymic output of T cells. We had the opportunity to examine parameters of thymic cellular output in several hypogonadal men undergoing androgen replacement therapy. Methods Circulating naive (CD4+CD45RA+) T cells were quantitated by flow cytometric analysis of peripheral blood mononuclear cells (PBMCs). Cells bearing T cell receptor excision circles (TRECs) were quantitated using real-time PCR amplification of DNA isolated from PBMCs from normal men and from hypogonadal men before and after testosterone replacement therapy. Results CD4+CD45+ (“naïve”) T cells comprised 10.5% of lymphocytes in normal males; this proportion was greatly increased in two hypogonadal men (35.5% and 44.4%). One man was studied sequentially during treatment with physiologic doses of testosterone. CD4+CD45RA+ cells fell from 37.36% to 20.05% after one month and to 12.51% after 7 months of normalized androgen levels. In two hypogonadal patients TREC levels fell by 83% and 78% after androgen replacement therapy. Conclusions Our observations indicate that the hypogonadal state is associated with increased thymic output of T cells and that this increase in recent thymic emigrants in peripheral blood is reversed by androgen replacement. PMID:21218609

Spontaneous rupture of thymic neuroendocrine carcinoma: A case report

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Park, Chan Yeong; Lee, In Jae; Min, Soo Kee [Hallym University College of Medicine, Chuncheon (Korea, Republic of)

2015-11-15

Thymic neuroendocrine carcinoma (NEC) is a rare neoplasm with tendencies of local invasion and metastasis. Usually, it is detected incidentally or by its symptoms caused by mass effect. Rupture of the tumor is extremely rare. In this study, we report a case of a ruptured thymic NEC that was combined with a potentially fatal hemorrhage. This lesion was manifested as a progressive bulging of the right cardiac border on serial chest radiographs, and on CT as a large anterior mediastinal mass with heterogeneous enhancement, internal necrosis, and hematoma.

Retinoic Acid Signaling in Thymic Epithelial Cells Regulates Thymopoiesis

DEFF Research Database (Denmark)

Wendland, Kerstin; Niss, Kristoffer; Kotarsky, Knut

2018-01-01

Despite the essential role of thymic epithelial cells (TEC) in T cell development, the signals regulating TEC differentiation and homeostasis remain incompletely understood. In this study, we show a key in vivo role for the vitamin A metabolite, retinoic acid (RA), in TEC homeostasis. In the abse......Despite the essential role of thymic epithelial cells (TEC) in T cell development, the signals regulating TEC differentiation and homeostasis remain incompletely understood. In this study, we show a key in vivo role for the vitamin A metabolite, retinoic acid (RA), in TEC homeostasis...

Antiretroviral therapy increases thymic output in children with HIV

DEFF Research Database (Denmark)

Schou Sandgaard, Katrine; Lewis, Joanna; Adams, Stuart

2014-01-01

OBJECTIVE: Disease progression and response to antiretroviral therapy (ART) in HIV-infected children is different to that of adults. Immune reconstitution in adults is mainly from memory T cells, whereas in children it occurs predominantly from the naive T-cell pool. It is unclear however what...... with a recently described mathematical model to give explicit measures of thymic output. RESULTS: We found that age-adjusted thymic output is reduced in untreated children with HIV, which increases significantly with length of time on ART. CONCLUSION: Our results suggest that a highly active thymus in early...

Effect of Bcl11b genotypes and γ-radiation on the development of mouse thymic lymphomas

International Nuclear Information System (INIS)

Yoshikai, Yoshihiro; Sato, Toshihiro; Morita, Shinichi; Kohara, Yuki; Takagi, Ritsuo; Mishima, Yukio; Kominami, Ryo

2008-01-01

Bcl11b is a haploinsufficient tumor suppressor gene and expressed in many tissues such as thymus, brain and skin. Irradiated Bcl11b +/- heterozygous mice mostly develop thymic lymphomas, but the preference of Bcl11b inactivation for thymic lymphomas remains to be addressed. We produced Bcl11b +/- heterozygous and Bcl11b wild-type mice of p53 +/- background and compared their incidence of γ-ray induced thymic lymphomas. Majority of the tumors in p53 +/- mice were skin tumors, and only 5 (36%) of the 14 tumors were thymic lymphomas. In contrast, Bcl11b +/- p53 +/- doubly heterozygous mice developed thymic lymphomas at the frequency of 27 (79%) of the 34 tumors developed (P = 0.008). This indicates the preference of Bcl11b impairment for thymic lymphoma development. We also analyzed loss of the wild-type alleles in the 27 lymphomas, a predicted consequence given by γ-irradiation. However, the loss frequency was low, only six (22%) for Bcl11b and five (19%) for p53. The frequencies did not differ from those of spontaneously developed thymic lymphomas in the doubly heterozygous mice, though the latency of lymphoma development markedly differed between them. This suggests that the main contribution of irradiation at least in those mice is not for the tumor initiation by inducing allelic losses but probably for the promotion of thymic lymphoma development

Modification of radiation-induced murine thymic lymphoma incidence by curcumin

International Nuclear Information System (INIS)

Dange, P.S.; Yadav, H.D.; Kumar, Vimalesh; Bhilwade, H.N.; Pandey, B.N.; Sarma, H.D.

2017-01-01

Curcumin is a known antioxidant, preventing radiation damage including carcinogenesis. However, concentration and feeding schedule of curcumin in modification of radiation induced thymic lymphoma incidence in vivo model has not been studied. We report here modification of incidence of γ-radiation-induced thymic lymphoma in mice fed with different doses of curcumin (0.05 to 1 %) in diet. Results: Female Swiss mice (6-8 weeks) fed with normal diet and exposed to 3 Gy whole body "6"0Co γ-irradiation (WBI) showed 85 % incidence of thymic lymphoma (TL) at 120 days post-irradiation. A concentration of 1 % curcumin was found the most effective in TL incidence prevention than other fed concentrations. The TL incidence was remarkably reduced when curcumin was fed to the mice before than after the radiation exposure. These results suggest modification of TL incidence by curcumin in irradiated mice involving DNA damage and apoptotic death mechanisms

Production of BMP4 by endothelial cells is crucial for endogenous thymic regeneration

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Wertheimer, Tobias; Velardi, Enrico; Tsai, Jennifer; Cooper, Kirsten; Xiao, Shiyun; Kloss, Christopher C.; Ottmüller, Katja J.; Mokhtari, Zeinab; Brede, Christian; deRoos, Paul; Kinsella, Sinéad; Palikuqi, Brisa; Ginsberg, Michael; Young, Lauren F.; Kreines, Fabiana; Lieberman, Sophia R.; Lazrak, Amina; Guo, Peipei; Malard, Florent; Smith, Odette M.; Shono, Yusuke; Jenq, Robert R.; Hanash, Alan M.; Nolan, Daniel J.; Butler, Jason M.; Beilhack, Andreas; Manley, Nancy R.; Rafii, Shahin; Dudakov, Jarrod A; van den Brink, Marcel RM

2018-01-01

The thymus is extremely sensitive to damage but also has a remarkable ability to repair itself. However, the mechanisms underlying this endogenous regeneration remain poorly understood and this capacity diminishes considerably with age. Here we show that thymic endothelial cells (ECs) comprise a critical pathway of regeneration, via their production of BMP4. ECs increased their production of BMP4 after thymic damage, and abrogating BMP4 signalling or production by either pharmacologic or genetic inhibition impaired thymic repair. EC-derived BMP4 acted on thymic epithelial cells (TECs) to increase their expression of Foxn1, a key transcription factor involved in TEC development, maintenance and regeneration; and its downstream targets such as Dll4, itself a key mediator of thymocyte development and regeneration. These studies demonstrate the importance of the BMP4 pathway in endogenous tissue regeneration and offer a potential clinical approach to enhance T cell immunity. PMID:29330161

Studies on radiation-induced thymic lymphomagenesis in B10 strain mice

International Nuclear Information System (INIS)

Muto, Masahiro

1989-01-01

Using B10.Thy 1 congenic strain mice, we reexamined the earlier results by Kaplan and others that lymphomas could develop from lymphocytes present in the nonirradiated parental thymuses grafted into thymectomized, fractionally irradiated H-2 semiincompatible recipient mice. The results indicated that 37 out of 91 thymectomized and irradiated B10.Thy 1.2 mice developed lymphomas of which 75 % were shown to have originated from grafted thymuses. The evidence was not obtained that supported the involvement of endogenous MuLV or some kind of transmissible agents during thymic lymphomagenesis. We found, with intrathymic injection assay, that 'preneoplastic' cells that will eventually develop into thymic lymphomas under the influence of thymic microenvironment first appeared in the thymuses about 4-8 days after irradiation. These thymic prelymphoma cells 'thymus-dependent' preneoplastic cells were detected in 26.1 % of the test donor thymuses when examined at 14 days and in more than 63 % 21 and 31 days after irradiation. It was found that lymphomagenic irradiation resulted in the anomalous appearance of CD4 + and/or CD8 + thymocytes bearing IL-2 receptor (IL-2R) which were different from normal thymocyte subpopulations. Thymic prelymphoma cells existed mainly in CD4 - CD8 - and CD4 - CD8 + thymocyted subpopulations and also in CD4 + CD8 + subpopulation. T cell lymphomas derived from CD4 - CD8 - prelymphoma cells had mainly CD4 - CD8 - or CD4 - CD8 + phenotypes. T cell lymphomas developed from CD4 - CD8 + prelymphoma cells mainly expressed CD4 - CD8 + or CD4 + CD8 + phenotype. T cell lymphomas originated from CD4 + CD8 + prelymphoma cells were mainly CD4 + CD8 + but some CD4 - CD8 + or CD4 + CD8 - cells were also present. These T cell lymphomas expressed IL-2R on various levels. The development of thymic prelymphoma cells is discussed in view of thymocyte differentiation. (J.P.N)

[Thymic carcinoma involving aortic arch; report of a case].

Science.gov (United States)

Noriyuki, Toshio; Hamamoto, M; Takazawa, Y; Katoh, K; Hashimoto, M; Kuranishi, F; Nakahara, M; Fukuda, T; Ishizaki, Y; Okuda, H; Akimoto, E; Yonehara, S

2009-05-01

Adenocarcinoma of the thymus is a very rare malignant tumor. The standard treatment for advanced thymic carcinoma has not yet been established, and the prognosis is poor. We report a case of thymic carcinoma that involving the aortic arch and the innominate vein. A 78-year-old woman was admitted to our hospital complaining of hoarseness in April 2007. The computed tomography (CT) scan showed an anterior mediastinal tumor contiguous to the aortic arch and the innominate vein with swelling lymphnodes. Microspcopic examinations of specimens obtained by CT-guided needle biopsy revealed poorly differenciated adenocarcinoma. The carcinoembryonic antigen (CEA) level of serum elevated at 54.9 ng/ml. Thymic carcinoma was diagnosed. The chemoradiotherapy [concurrent, carboplatin (CBDCA) + paclitaxel(TXL)-->vinorelbine (NVB), 60 Gy] was performed, but the effect of the therapy was limited. The resection of the tumor with a part of aortic arch and other peripheral tissues was performed in Augast 2007. The postoperative course was uneventful and the CEA level of serum lowered to the normal. She was discharged 30 days after surgery.

Thyroid and thymic exeresis in surgery of hyperparathyroidism.

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Diaconescu, Mr; Glod, M; Costea, I; Grigorovici, M; Diaconescu, S

2014-01-01

Owing to close anatomical and embryological connexions between the thyroid, parathyroids and thymus,manifold coexisting pathology can be identified during the surgery of hyperparathyroidism (Hp). In this retrospective study we report the incidence, clinical forms, histology and management of thyroid and thymic synchronous lesions encountered in as eries of 82 consecutive patients with various types of Hp operated on in the last three decades. Demography, clinical records, biochemical data, imaging procedures, pathology reports and surgical protocols were revised. Between 1984-2013, 82 cases of Hp, 20 primary and 62 renal (27 secondary and 35 tertiary), 57 women and 25 males (sex ratio: 2.3 1) of 15-72 (mean 46.5) years, under went surgery in our clinic. Concomitant thyroid exereses were performed in 32 patients (2 subtotal thyroidectomies, 12 lobectomies, 8 atypical resections and 10 diagnosis biopsies), foruni- or bilateral (multi)nodular goiters or different €œminutelesions. Pathology showed 11 colloid goiters, 3 follicular adenomas,5 nodular hyperplasias and 6 thyroiditis cases, 3 papillary microcarcinomas and 4 specimens with normal thyroid tissue.Excision of the fibrofatty retromanubrial tissue in total parathyroidectomies for renal Hp (19 cases) revealed one nonmyastenicthymoma, one thymic cyst and thymic remnants in 6 patients.Morbidity in these extended operations was not significantly increased, comparing to the parathyroid exploration alone. Meticulous pre- and intraoperative evaluation in all cases of Hp enables the actual shift from bilateral neck exploration to minimally invasive surgery,increasing however the potential risk of missing thyroid or thymic coexistent significant lesions. The surgeon dedicated to this pathology must be aware of the possibility of encountering such synchronous association and make generous efforts to wards their complete cure in a single operation. Celsius.

Diagnostic value of plain chest roentgenogram and CT scan findings in four cases of massive thymic hyperplasia

International Nuclear Information System (INIS)

Kobayashi, T.; Hirabayashi, Y.; Kobayashi, Y.

1986-01-01

Massive thymic hyperplasia (MTH) is rare in the pediatric age group, especially in infants. However, because of a wide variation in size and weight of the thymus, an enlarged gland is often resected because of suspicion of a neoplasm or a cyst. Some cases of thymoma resembling pulmonary acute infection occur less frequently than MTH, but if respiratory problems are accompanied by a large thymus immediate diagnosis is often necessary to differentiate between these two conditions. Four infants (14 days to 4 months of age) with MTH were recently studied, all having an acute onset an of severe respiratory distress. The infants were referred to our center with a tentative diagnosis of thymic or other intrathoracic tumors. The following case reports illustrate our diagnostic approach to evaluate patients with symptoms suggesting MTH and the response to the ''steroid test''. (orig.)

A rear case of multilocular thymic cyst with follicular lymphoid hyperplasia; Radiologic and histopathologic features

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Kim, Jin Suk; Cha, Eun Jung [Konyang University Hospital, Daejeon (Korea, Republic of)

2016-06-15

Multilocular thymic cysts are rare and acquired lesions induced by an inflammatory arising within the thymus. We report a rare case of multilocular thymic cyst with follicular lymphoid hyperplasia in a 59-year-old female. Chest CT and MRI revealed a large multilocular cystic mass, which contains thick septa and nodules in the thymus. F-18 FDG PET/CT showed almost no FDG uptake of the multilocular cystic mass but moderate FDG uptake of the solid nodules. Extended total thymectomy was performed. Histopathological findings revealed follicular lymphoid hyperplasia of thymic tissue but no neoplastic lesion. Based on these findings, diagnosis of multilocular thymic cyst with follicular lymphoid hyperplasia was made. This is a rare case that preoperatively was difficult to diagnose.

Generation of Tumor Antigen-Specific iPSC-Derived Thymic Emigrants Using a 3D Thymic Culture System

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Raul Vizcardo

2018-03-01

Full Text Available Summary: Induced pluripotent stem cell (iPSC-derived T cells may provide future therapies for cancer patients, but those generated by current methods, such as the OP9/DLL1 system, have shown abnormalities that pose major barriers for clinical translation. Our data indicate that these iPSC-derived CD8 single-positive T cells are more like CD4+CD8+ double-positive T cells than mature naive T cells because they display phenotypic markers of developmental arrest and an innate-like phenotype after stimulation. We developed a 3D thymic culture system to avoid these aberrant developmental fates, generating a homogeneous subset of CD8αβ+ antigen-specific T cells, designated iPSC-derived thymic emigrants (iTEs. iTEs exhibit phenotypic and functional similarities to naive T cells both in vitro and in vivo, including the capacity for expansion, memory formation, and tumor suppression. These data illustrate the limitations of current methods and provide a tool to develop the next generation of iPSC-based antigen-specific immunotherapies. : A barrier for clinical application of iPSC-derived CD8 T cells using OP9/DLL1 is their abnormal biology. Vizcardo et al. show that a 3D thymic culture system enables the generation of a homogeneous antigen-specific T cell subset, named iTEs, which closely mimics naive T cells and exhibits potent anti-tumor activity. Keywords: thymopoiesis, T cell differentiation, iPSC differentiation, adoptive cell transfer, naïve T cell, recent rhymic emigrants, fetal thymus organ culture, immunotherapy, 3D culture, tumor antigen specific T cell

Elevation of oleate-activated phospholipase D activity during thymic atrophy

Science.gov (United States)

Lee, Youngkyun; Song, Soo-Mee; Park, Heung Soon; Kim, Sungyeol; Koh, Eun-Hee; Choi, Myung Sun; Choi, Myung-Un

2002-01-01

Various phospholipases are thought to be associated with the in vitro apoptosis of thymocytes. In the present study, the in vivo phospholipase D (PLD) activity of rat thymus was studied after whole-body X-irradiation or injection of dexamethasone (DEX). Using exogenous [14C]dipalmitoyl phosphatidylcholine (PC) as the substrate, an elevation of oleate-activated PLD activity was observed during thymic atrophy. The activity increases were sevenfold at 48 hr after 5-Gy irradiation and fourfold at 72 hr after injection of 5 mg/kg DEX. The elevation of PLD activity appeared to parallel extensive thymus shrinkage. An increased level of thymic phosphatidic acid (PA), the presumed physiological product of PLD action on PC, was also detected. By comparing the acyl chains of PA with those of other phospholipids, PA appeared to originate from PC. To assess the role of PLD during thymic atrophy, thymocytes and stromal cells were isolated. Although thymocytes themselves exhibited significant PLD activation, the major elevation in PLD activity (greater than fourfold) was found in isolated stromal cells. PLD was also activated during in vitro phagocytosis of apoptotic thymocytes by the macrophage-like cell line P388D1. This in vitro phagocytosis was significantly inhibited by PLD action blockers, such as 2,3-diphosphoglycerate and 1-butanol. These observations strongly suggest that the alteration of oleate-activated PLD activity is part of an in vivo event in the progression of thymic atrophy, including phagocytic clearance of apoptotic thymocytes. PMID:12460188

Platinum-based chemotherapy with or without thoracic radiation therapy in patients with unresectable thymic carcinoma

International Nuclear Information System (INIS)

Nakamura, Yoichi; Kunitoh, Hideo; Kubota, Kaoru

2000-01-01

Thymic carcinoma is a rare mediastinal neoplasm with poor prognosis. Although the clinical benefit of chemotherapy for thymic carcinoma is controversial, cisplatin-based chemotherapy with or without radiation therapy is ordinarily adopted in advanced cases. We evaluated the clinical outcome of platinum-based chemotherapy with or without radiation therapy in unresectable thymic carcinoma patients. Ten patients with unresectable thymic carcinoma were treated with platinum-based chemotherapy with or without radiation therapy in the National Cancer Center Hospital between 1989 and 1998. We reviewed the histological type, treatment, response and survival of these patients. Four of the 10 patients responded to chemotherapy and both the median progression-free survival period and the median response duration were 6.0 months. The median survival time was 11.0 months. There was no relationship between histological classification and prognosis. Platinum-based chemotherapy with or without thoracic radiation is, regardless of tumor histology, marginally effective in advanced thymic carcinoma patients, giving only a modest tumor response rate and short response duration and survival. (author)

Anti-apoptotic signature in thymic squamous cell carcinomas - functional relevance of anti-apoptotic BIRC3 expression in the thymic carcinoma cell line 1889c

Directory of Open Access Journals (Sweden)

Bei eHuang

2013-12-01

Full Text Available The molecular pathogenesis of thymomas and thymic carcinomas (TCs is poorly understood and results of adjuvant therapy are unsatisfactory in case of metastatic disease and tumor recurrence. For these clinical settings, novel therapeutic strategies are urgently needed. Recently, limited sequencing efforts revealed that a broad spectrum of genes that play key roles in various common cancers are rarely affected in thymomas and thymic carcinomas, suggesting that other oncogenic principles might be important. This made us re-analyze historic expression data obtained in a spectrum of thymomas and thymic squamous cell carcinomas (TSCC with a custom made cDNA microarray. By cluster analysis, different anti-apoptotic signatures were detected in type B3 thymoma and TSCC, including overexpression of BIRC3 in TSCCs. This was confirmed by qRT-PCR in the original and an independent validation set of tumors. In contrast to several other cancer cell lines, the BIRC3-positive TSCC cell line, 1889c showed spontaneous apoptosis after BIRC3 knock-down. Targeting apoptosis genes is worth testing as therapeutic principle in TSCC.

Acute respiratory failure revealing a multilocular thymic cyst in an infant: a case report.

Science.gov (United States)

Asma, Bouziri; Ammar, Khaldi; Khaled, Menif; Najoua, Guandoura; Nejla, Ben Jaballah

2009-11-30

Multilocular thymic cysts are rare benign lesions of the neck and mediastinum that can occur at any age. In children, multilocular thymic cysts are usually symptomatic after the age of 2 years and produce few symptoms. We present an unusual case of a multilocular thymic cyst diagnosed in a 3-month-old girl and causing severe respiratory failure. A 3 month-old-girl, with a medical history of dyspnea and wheezing since the age of 20 days, presented in our pediatric intensive care unit for acute respiratory failure requiring mechanical ventilation. The chest radiograph showed thoracic distension without any other abnormalities. The diagnosis of severe asthma was initially suspected and the patient was treated by intravenous corticosteroids and continuous perfusion of salbutamol without any improvement. A chest tomography scan was performed and demonstrated an anterior mediastinal multiseptated cystic mass extending from the inferior face of the thyroid gland to the left cardiophrenic angle. Sternotomy and excision biopsy were planned urgently. The cystic mass was excised completely. The histopathological examination confirmed the diagnosis of a multilocular thymic cyst. The particularities of our observation are the occurrence of a multilocular thymic cyst in a young infant and its presentation by a severe acute respiratory failure mimicking asthma.

When larger brains do not have more neurons: Increased numbers of cells are compensated by decreased average cell size across mouse individuals

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Suzana eHerculano-Houzel

2015-06-01

Full Text Available There is a strong trend toward increased brain size in mammalian evolution, with larger brains composed of more and larger neurons than smaller brains across species within each mammalian order. Does the evolution of increased numbers of brain neurons, and thus larger brain size, occur simply through the selection of individuals with more and larger neurons, and thus larger brains, within a population? That is, do individuals with larger brains also have more, and larger, neurons than individuals with smaller brains, such that allometric relationships across species are simply an extension of intraspecific scaling? Here we show that this is not the case across adult male mice of a similar age. Rather, increased numbers of neurons across individuals are accompanied by increased numbers of other cells and smaller average cell size of both types, in a trade-off that explains how increased brain mass does not necessarily ensue. Fundamental regulatory mechanisms thus must exist that tie numbers of neurons to numbers of other cells and to average cell size within individual brains. Finally, our results indicate that changes in brain size in evolution are not an extension of individual variation in numbers of neurons, but rather occur through step changes that must simultaneously increase numbers of neurons and cause cell size to increase, rather than decrease.

Deregulation of mTOR signaling is involved in thymic lymphoma development in Atm-/- mice

International Nuclear Information System (INIS)

Kuang, Xianghong; Shen, Jianjun; Wong, Paul K.Y.; Yan, Mingshan

2009-01-01

Abnormal thymocyte development with thymic lymphomagenesis inevitably occurs in Atm-/- mice, indicating that ATM plays a pivotal role in regulating postnatal thymocyte development and preventing thymic lymphomagenesis. The mechanism for ATM controls these processes is unclear. We have shown previously that c-Myc, an oncoprotein regulated by the mammalian target of rapamycin (mTOR), is overexpressed in Atm-/- thymocytes. Here, we show that inhibition of mTOR signaling with its specific inhibitor, rapamycin, suppresses normal thymocyte DNA synthesis by downregulating 4EBP1, but not S6K, and that 4EBP1 phosphorylation and cyclin D1 expression are coordinately increased in Atm-/- thymocytes. Administration of rapamycin to Atm-/- mice attenuates elevated phospho-4EBP1, c-Myc and cyclin D1 in their thymocytes, and delays thymic lymphoma development. These results indicate that mTOR downstream effector 4EBP1 is essential for normal thymocyte proliferation, but deregulation of 4EBP1 in Atm deficiency is a major factor driving thymic lymphomagenesis in the animals.

CT features of the subtypes of thymic epithelial tumors on the basis of the world health organization classification

International Nuclear Information System (INIS)

Guo Xiaoyu; Yu Hong; Xiao Xiangsheng

2013-01-01

Thymic epithelial tumors including thymomas and thymic carcinomas have well-known heterogeneous oncologic behaviors and variable histologic features. They show variable and unpredictable evolutions ranging from an indolent non-invasive feature to a highly infiltrative and metastasising one. Currently, CT is a common and efficient imaging method for assessing thymic epithelial tumors. CT evaluation is the main reference for preoperative clinic staging and histological classification. CT features of subtypes of thymic epithelial tumors on the basis of the World Health Organization classification provide the foundation for the diagnosis and predicting prognosis. (authors)

PICTORIAL ESSAY Thymic masses: A radiological review

African Journals Online (AJOL)

On chest X-ray, thymic abnormalities typically manifest as focal or diffuse ... Department of Radiodiagnosis and Imaging, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India. Corresponding author: B ... are considered of primary mediastinal origin if there is neither a detectable gonadal primary nor.

Adjuvant Therapy for Thymic Carcinoma--A Decade of Experience in a Taiwan National Teaching Hospital.

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Yen-Han Tseng

Full Text Available Thymic carcinomas are rare tumors for which surgical resection is the first treatment of choice. The role of adjuvant treatment after surgery is unknown because of limited available data. The present study evaluated the efficacy of post-surgery adjuvant chemotherapy or radiotherapy in patients with thymic carcinoma.To evaluate the role of adjuvant therapy in patients with thymic carcinoma, we retrospectively reviewed the records of patients with thymic carcinoma who were diagnosed and treated between 2004 and 2014.Among 78 patients with thymic carcinoma, 30 patients received surgical resection. Progression-free survival (PFS and overall survival (OS were significantly longer among these patients than among patients who received other treatments (PFS: 88.4 months vs 9.1 months, p<0.001; OS: 134.9 months vs 60.9 months; p = 0.003. Patients with stage III thymic carcinoma who received surgery had a longer OS than patients who did not receive surgery (70.1 months vs 23.9 months; p = 0.017, n = 11. Among 47 patients with stage IV carcinoma, 12 patients who received an extended thymothymectomy had a longer PFS than 35 patients who did not receive surgery (18.9 months vs 8.7 months; p = 0.029. Among 30 patients (with stage I- IV carcinoma who received primary lesion surgery, 19 patients received an R0 resection and 9 patients of the 19 patients received adjuvant radiotherapy. These patients had longer PFS (50.3 months than 2 patients who received adjuvant chemotherapy (5.9 months or 4 patients who received concurrent chemoradiotherapy (7.5 months after surgery (p = 0.003.Surgical resection should be considered for patients with thymic carcinoma, even for patients with locally advanced or stage IV carcinoma. Adjuvant radiotherapy resulted in a better PFS after R0 resection.

[Impact of thymic function in age-related immune deterioration].

Science.gov (United States)

Ferrando-Martínez, Sara; de la Fuente, Mónica; Guerrero, Juan Miguel; Leal, Manuel; Muñoz-Fernández, M Ángeles

2013-01-01

Age-related biological deterioration also includes immune system deterioration and, in consequence, a rise in the incidence and prevalence of infections and cancers, as well as low responses to vaccination strategies. Out of all immune cell subsets, T-lymphocytes seem to be involved in most of the age-related defects. Since T-lymphocytes mature during their passage through the thymus, and the thymus shows an age-related process of atrophy, thymic regression has been proposed as the triggering event of this immune deterioration in elderly people. Historically, it has been accepted that the young thymus sets the T-lymphocyte repertoire during the childhood, whereupon atrophy begins until the elderly thymus is a non-functional evolutionary trace. However, a rising body of knowledge points toward the thymus functioning during adulthood. In the elderly, higher thymic function is associated with a younger immune system, while thymic function failure is associated with all-cause mortality. Therefore, any new strategy focused on the improvement of the elderly quality of life, especially those trying to influence the immune system, should take into account, together with peripheral homeostasis, thymus function as a key element in slowing down age-related decline. Copyright © 2012 SEGG. Published by Elsevier Espana. All rights reserved.

Interaction between thymic cells and hemopoietic stem cells. Enhanced repopulation of the irradiated thymus

International Nuclear Information System (INIS)

Daculsi, Richard; Legrand, Elisabeth; Duplan, J.-F.

1977-01-01

In irradiated mice engrafted with hemopoietic cells, the thymus is repopulated more rapidly by bone marrow-derived than by spleen-derived cells. Admixing thymic cells with restorative suspension stimulates the thymic repopulation by spleen-derived cells whereas it has no effect on the repopulation by bone marrow-derived cells [fr

Lymphocyte depletion in thymic nurse cells: a tool to identify in situ lympho-epithelial complexes having thymic nurse cell characteristics

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Leene, W.; de Waal Malefijt, R.; Roholl, P. J.; Hoeben, K. A.

1988-01-01

In situ pre-existing complexes of epithelial cells and thymocytes having thymic nurse cell characteristics were visualized in the murine thymus cortex using dexamethasone as a potent killer of cortisone-sensitive thymocytes. The degradation and subsequent depletion of cortisone-sensitive thymocytes

Thymic function in the regulation of T cells, and molecular mechanisms underlying the modulation of cytokines and stress signaling (Review).

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Yan, Fenggen; Mo, Xiumei; Liu, Junfeng; Ye, Siqi; Zeng, Xing; Chen, Dacan

2017-11-01

The thymus is critical in establishing and maintaining the appropriate microenvironment for promoting the development and selection of T cells. The function and structure of the thymus gland has been extensively studied, particularly as the thymus serves an important physiological role in the lymphatic system. Numerous studies have investigated the morphological features of thymic involution. Recently, research attention has increasingly been focused on thymic proteins as targets for drug intervention. Omics approaches have yielded novel insights into the thymus and possible drug targets. The present review addresses the signaling and transcriptional functions of the thymus, including the molecular mechanisms underlying the regulatory functions of T cells and their role in the immune system. In addition, the levels of cytokines secreted in the thymus have a significant effect on thymic functions, including thymocyte migration and development, thymic atrophy and thymic recovery. Furthermore, the regulation and molecular mechanisms of stress‑mediated thymic atrophy and involution were investigated, with particular emphasis on thymic function as a potential target for drug development and discovery using proteomics.

Rapid development of thymic neuroendocrine carcinoma despite transcervical thymectomy in a patient with multiple endocrine neoplasia type 1

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Dhalapathy Sadacharan

2013-01-01

Full Text Available Thymic neuroendocrine (NE tumors are a rare manifestation of multiple endocrine neoplasia syndrome type 1 (MEN-1. They are malignant and aggressive tumors and form a major cause of mortality in MEN-1. Transcervical thymectomy (TCT at the time of parathyroid surgery for primary hyperparathyroidism (PHPT in MEN-1 usually prevents thymic NE tumors. We report a 56-year-old nonsmoker male with sporadic MEN-1 who presented with thymic NE carcinoma developing rapidly within a span of 8 months after subtotal parathyroidectomy and TCT for PHPT. We present a brief review of literature on this rare NE malignancy, focusing on its occurrence despite TCT. This case highlights the fact that thymic NE carcinoma may develop even after TCT in MEN-1. Regular surveillance for these aggressive thymic NE tumors is mandatory even after TCT in MEN-1 setting.

Clinical results of radiation therapy for thymic tumors

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Masunaga, Shin-ichiro; Ono, Koji; Hiraoka, Masahiro; Kitakabu, Yoshizumi; Abe, Mitsuyuki (Kyoto Univ. (Japan). Faculty of Medicine); Takahashi, Masaji; Fushiki, Masato

1991-12-01

From August 1968 to December 1989, 58 patients with thymoma, and 3 with thymic carcinoma were treated by radiotherapy using cobalt-60 gamma ray. Eleven cases were treated by radiotherapy alone, 1 by preoperative radiotherapy, 45 by postoperative radiotherapy, and 4 in combination with intraoperative radiotherapy. In thymoma, postoperative and intraoperative radiotherapies were effective, while concerning postoperative radiotherapy, operability was the major factor influencing survival and local control, and Stage I and II tumors resected totally or subtotally as well as Stage III tumors resected totally were good indications for such therapy. Cases of thymoma complicated by myasthenia gravis had a longer survival time and better local control rate than those without it. In the treatment of thymic carcinoma, it was suggested that the tumors can be controlled using complete resection and sufficient postoperative radiotherpay. (author).

Clinical results of radiation therapy for thymic tumors

International Nuclear Information System (INIS)

Masunaga, Shin-ichiro; Ono, Koji; Hiraoka, Masahiro; Kitakabu, Yoshizumi; Abe, Mitsuyuki; Takahashi, Masaji; Fushiki, Masato.

1991-01-01

From August 1968 to December 1989, 58 patients with thymoma, and 3 with thymic carcinoma were treated by radiotherapy using cobalt-60 gamma ray. Eleven cases were treated by radiotherapy alone, 1 by preoperative radiotherapy, 45 by postoperative radiotherapy, and 4 in combination with intraoperative radiotherapy. In thymoma, postoperative and intraoperative radiotherapies were effective, while concerning postoperative radiotherapy, operability was the major factor influencing survival and local control, and Stage I and II tumors resected totally or subtotally as well as Stage III tumors resected totally were good indications for such therapy. Cases of thymoma complicated by myasthenia gravis had a longer survival time and better local control rate than those without it. In the treatment of thymic carcinoma, it was suggested that the tumors can be controlled using complete resection and sufficient postoperative radiotherpay. (author)

Application values of 99mTc-methoxyisobutylisonitrile imaging for differentiating benign and malignant thymic masses.

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Lu, Chenghui; Wang, Xufu; Liu, Bin; Liu, Xinfeng; Wang, Guoming; Zhang, Qin

2017-08-01

The aim of the present study was to investigate the application value of 99m Tc-methoxyisobutylisonitrile (MIBI) imaging to differentiate between benign and malignant thymic masses. A total of 32 patients with space-occupying mediastinal masses were enrolled and early and delayed-phase images were collected following injection with the imaging agent. The tumor to background ratio (T/N) values at the different phases were also recorded. The sensitivity of the qualitative analysis to distinguish between benign and malignant thymic masses was 95.24%, with specificity as 90.91%. The T/N values in the early and delayed phases were not significantly different in the group with benign thymic masses, but demonstrated statistical significant differences in the groups with low- and intermediate-grade malignant thymic masses. The T/N values at the above early and delayed phase were significantly different between the benign and low-grade malignancy groups, as well as between low- and moderate-grade malignancy groups. Those between the benign and moderate-grade malignancy groups demonstrated no significant difference. 99m Tc-MIBI imaging was able to differentiate between benign and malignant thymic masses, and the simultaneous semi-quantitative analysis of the T/N values of the tumors may be able to initially determine the degree of malignancy of thymoma.

Volume-based quantification using dual-energy computed tomography in the differentiation of thymic epithelial tumours: an initial experience

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Chang, Suyon; Hur, Jin; Im, Dong Jin; Suh, Young Joo; Hong, Yoo Jin; Lee, Hye-Jeong; Kim, Young Jin; Choi, Byoung Wook [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Seoul (Korea, Republic of); Han, Kyunghwa [Yonsei University College of Medicine, Yonsei Biomedical Research Institute, Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Seoul (Korea, Republic of); Kim, Dae Joon; Lee, Chang Young [Yonsei University College of Medicine, Department of Thoracic and Cardiovascular Surgery, Seoul (Korea, Republic of); Shin, Ha Young [Yonsei University College of Medicine, Department of Neurology, Seoul (Korea, Republic of)

2017-05-15

To investigate the diagnostic value of dual-energy computed tomography (DECT) in differentiating between low- and high-risk thymomas and thymic carcinomas. Our institutional review board approved this study, and patients provided informed consent. We prospectively enrolled 37 patients (20 males, mean age: 55.6 years) with thymic epithelial tumour. All patients underwent DECT. For quantitative analysis, two reviewers measured the following tumour parameters: CT attenuation value in contrast Hounsfield units (CHU), iodine-related HU and iodine concentration (mg/ml). Pathological results confirmed the final diagnosis. Of the 37 thymic tumours, 23 (62.2 %) were low-risk thymomas, five (13.5 %) were high-risk thymomas and nine (24.3 %) were thymic carcinomas. According to quantitative analysis, iodine-related HU and iodine concentration were significantly different among low-risk thymomas, high-risk thymomas and thymic carcinomas (median: 29.78 HU vs. 14.55 HU vs. 19.95 HU, p = 0.001 and 1.92 mg/ml vs. 0.99 mg/ml vs. 1.18 mg/ml, p < 0.001, respectively). DECT using a quantitative analytical method based on iodine concentration measurement can be used to differentiate among thymic epithelial tumours using single-phase scanning. (orig.)

{sup 18}F-FDG uptake on PET in primary mediastinal non-thymic neoplasm: A clinicopathological study

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Kaira, Kyoichi, E-mail: kkaira1970@yahoo.co.jp [Division of Thoracic Oncology, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Abe, Masato [Division of Pathology, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Nakagawa, Kazuo; Ohde, Yasuhisa; Okumura, Takehiro [Division of Thoracic Surgery, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Takahashi, Toshiaki; Murakami, Haruyasu; Shukuya, Takehito; Kenmotsu, Hirotsugu; Naito, Tateaki [Division of Thoracic Oncology, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Hayashi, Isamu [Division of Pathology, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Oriuchi, Noboru [Department of Diagnostic Radiology and Nuclear medicine, Gunma University Graduate School of Medicine, Showa-machi, Maebashi 371-8511, Gunma (Japan); Endo, Masahiro [Division of Diagnostic Radiology, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Kondo, Haruhiko [Division of Thoracic Surgery, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Nakajima, Takashi [Division of Pathology, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan); Yamamoto, Nobuyuki [Division of Thoracic Oncology, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777 (Japan)

2012-09-15

Background: The usefulness of 2-[{sup 18}F]-fluoro-2-deoxy-D-glucose ({sup 18}F-FDG) positron emission tomography (PET) has been investigated in thymic epithelial tumors. However, little is known about PET imaging of {sup 18}F-FDG in primary non-thymic mediastinal neoplasms. The aim of this study is to explore the clinicopathological significance of {sup 18}F-FDG PET in primary mediastinal (non-thymic) neoplasms. Methods: Twenty-one patients with mediastinal neoplasms who underwent {sup 18}F-FDG PET before treatment were included in this study. Tumor sections were stained by immunohistochemistry for glucose transporter 1 (Glut1); glucose transporter 3 (Glut3); hypoxia-inducible factor-1 alpha (HIF-1α); hexokinase I; vascular endothelial growth factor (VEGF); microvessels (CD34); epidermal growth factor receptor (EGFR); Akt/mTOR signaling pathway (p-Akt and p-mTOR); cell cycle control (p53). Results: Seventeen of 21 patients were imaged on PET system using {sup 18}F-FDG, but 4 patients with a histology of cyst showed nothing abnormal in PET scans. The histology of the resected tumors was as follows: 6 schwannoma, 3 teratoma, 4 cyst, 3 sarcoma, 1 undifferentiated carcinoma, 1 seminoma, 1 mediastinal goiter, 1 ganglioneuroma, and 1 Hodgkin lymphoma. {sup 18}F-FDG uptake was significantly correlated with Glut1, HIF-1α, EGFR, p-Akt and p-S6K. These biomarkers were highly expressed in schwannoma, teratoma and high grade malignancies, whereas all patients with cyst and ganglioneuroma had no positive expression of these biomarkers. High uptake of {sup 18}F-FDG was significant associated with Glut1, VEGF, EGFR, p-Akt, p-S6K and tumor maximal size. Conclusion: The amount of {sup 18}F-FDG uptake in primary mediastinal non-thymic neoplasms is determined by the presence of glucose metabolism (Glut1), hypoxia (HIF-1α) and upstream components of HIF-1α (EGFR, p-Akt and p-S6K)

Thymic hyperplasia in a patient with Grave's disease.

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Hamzaoui, Amira A; Klii, Rim R; Salem, Randa R; Kochtali, Ines I; Golli, Mondher M; Mahjoub, Silvia S

2012-02-09

Hyperplastic changes of the thymus may be found in patients with Graves' disease. However, this rarely presents as an anterior mediastinal mass, particularly among adults. In this report, we describe a 46-year old woman with Graves' disease and thymic hyperplasia.

Age-Associated Decline in Thymic B Cell Expression of Aire and Aire-Dependent Self-Antigens

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Sergio Cepeda

2018-01-01

Full Text Available Although autoimmune disorders are a significant source of morbidity and mortality in older individuals, the mechanisms governing age-associated increases in susceptibility remain incompletely understood. Central T cell tolerance is mediated through presentation of self-antigens by cells constituting the thymic microenvironment, including epithelial cells, dendritic cells, and B cells. Medullary thymic epithelial cells (mTECs and B cells express distinct cohorts of self-antigens, including tissue-restricted self-antigens (TRAs, such that developing T cells are tolerized to antigens from peripheral tissues. We find that expression of the TRA transcriptional regulator Aire, as well as Aire-dependent genes, declines with age in thymic B cells in mice and humans and that cell-intrinsic and cell-extrinsic mechanisms contribute to the diminished capacity of peripheral B cells to express Aire within the thymus. Our findings indicate that aging may diminish the ability of thymic B cells to tolerize T cells, revealing a potential mechanistic link between aging and autoimmunity.

A Whole-Tumor Histogram Analysis of Apparent Diffusion Coefficient Maps for Differentiating Thymic Carcinoma from Lymphoma.

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Zhang, Wei; Zhou, Yue; Xu, Xiao-Quan; Kong, Ling-Yan; Xu, Hai; Yu, Tong-Fu; Shi, Hai-Bin; Feng, Qing

2018-01-01

To assess the performance of a whole-tumor histogram analysis of apparent diffusion coefficient (ADC) maps in differentiating thymic carcinoma from lymphoma, and compare it with that of a commonly used hot-spot region-of-interest (ROI)-based ADC measurement. Diffusion weighted imaging data of 15 patients with thymic carcinoma and 13 patients with lymphoma were retrospectively collected and processed with a mono-exponential model. ADC measurements were performed by using a histogram-based and hot-spot-ROI-based approach. In the histogram-based approach, the following parameters were generated: mean ADC (ADC mean ), median ADC (ADC median ), 10th and 90th percentile of ADC (ADC 10 and ADC 90 ), kurtosis, and skewness. The difference in ADCs between thymic carcinoma and lymphoma was compared using a t test. Receiver operating characteristic analyses were conducted to determine and compare the differentiating performance of ADCs. Lymphoma demonstrated significantly lower ADC mean , ADC median , ADC 10 , ADC 90 , and hot-spot-ROI-based mean ADC than those found in thymic carcinoma (all p values histogram analysis of ADC maps can improve the differentiating performance between thymic carcinoma and lymphoma.

Micronodular thymic neoplasms: case series and literature review with emphasis on the spectrum of differentiation.

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Mneimneh, Wadad S; Gökmen-Polar, Yesim; Kesler, Kenneth A; Loehrer, Patrick J; Badve, Sunil

2015-11-01

We report nine cases of micronodular thymoma with lymphoid B-cell hyperplasia and one case of micronodular thymic carcinoma with lymphoid hyperplasia from our institution. For a better understanding of these rare tumors, clinical records, and histological features of these cases were reviewed, with detailed review of additional 64 literature cases of micronodular thymic neoplasms. The joint analysis identified 64 cases of micronodular thymoma with lymphoid B-cell hyperplasia and 9 cases of micronodular thymic carcinoma with lymphoid hyperplasia. Both groups revealed slight male predilection, with male:female ratio of 1.3:1 and 5:4, and occurred at >40 years of age, with a mean of 64 (41-83) and 62 (42-78) years, respectively. Myasthenia gravis was noted in 3/64 (5%) and 1/9 (11%) patients, respectively. Other systemic, disimmune, or hematologic disorders were noted in 6/64 (9%) and 1/9 (11%) patients, respectively. Components of conventional thymoma were reported in 11/64 (17%) micronodular thymomas with lymphoid B-cell hyperplasia, with transitional morphology between the two components in most of them. Cellular morphology was predominantly spindle in micronodular thymoma with lymphoid B-cell hyperplasia when specified (30/43), and epithelioid in micronodular thymic carcinoma with lymphoid hyperplasia (6/9), and cytological atypia was more encountered in the latter. Dedifferentiation/transformation from micronodular thymoma with lymphoid B-cell hyperplasia to micronodular thymic carcinoma with lymphoid hyperplasia seems to occur in a small subset of cases. Three cases of micronodular thymomas with lymphoid B-cell hyperplasia were described with co-existent low-grade B-cell lymphomas. Follow-up data were available for 30 micronodular thymomas with lymphoid B-cell hyperplasia and 6 micronodular thymic carcinomas with lymphoid hyperplasia, with a mean of 47 (0.2-180) months and 23 (3-39) months, respectively. Patients were alive without disease, except for five

Bilateral cervical ectopic thymic nodules with accessory thyroid tissue and an ectopic parathyroid in the neck region

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Wea-Lung Lin

2011-03-01

Full Text Available Some remnants of thymic tissue may be deposited along the pathway of the descent of the neck during embryologic development of the thymus. Ectopic thymic tissue is usually deposited along the pathway from the mandibular angle to the manubrium of the sternum. Most reported cases of an ectopic thymus occurred in children, and cases are less common in adults. We report a 26-year-old woman, who was incidentally found to have 2 neck nodules on the posterior side of the bilateral upper pole of the thyroid gland while undergoing a subtotal thyroidectomy. The left-side neck nodule showed accessory thyroid follicles intermixed with ectopic thymic tissue, and the right-side neck nodule was ectopic parathyroid tissue together with ectopic thymic tissue.

Thymic irradiation and chronic myelogenous leukemia

International Nuclear Information System (INIS)

Shimaoka, K.; Sokal, J.E.

1977-01-01

Two cases of Ph positive chronic myelogenous leukemia with a history of thymic irradiation are presented. Both patients received radiation therapy from low voltage x-ray equipment at two to three months of age. Leukemia developed 18 and 22 years later. Presentation, response to antileukemic therapy, and clinical course did not differ from that of other patients with this disease treated in our department

Photoperiodic modulation of local melatonin synthesis and its role in regulation of thymic homeostasis in Funambulus pennanti.

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Gupta, Sameer; Haldar, Chandana

2016-12-01

The effect of photo-neuroendocrine system on the thymic (immune) functions is mediated by gonadal steroid and the pineal hormone melatonin. The present study explored the effect of photoperiod on the thymic melatonergic system and its role in protection of thymic T-cells from the testosterone induced seasonal oxidative stress and apoptosis. Exposure to long day-length (LD) was noted to decrease local (thymic) melatonin content and induce oxidative stress and apoptosis in the thymus. Increased peripheral level of testosterone upregulated the androgen receptor expression and, consequently reduced proliferation response of the thymocytes. Short day conditions (SD) however, reversed the effect of LD on the thymic physiology. Low level of testosterone was concomitant with diminished nitro-oxidative stress and decreased expression of redox sensitive factors (NF-κB, p53 and Bax/Bcl-2 ratio) in the thymus. SD retarded activation of caspase-3 resulting in procaspase-3 accumulation. Further, in vitro treatment of thymocytes with AR antagonist flutamide impaired the sensitivity of thymocytes to androgen and reversed the deleterious effects of testosterone on the proliferative and apoptotic responses of thymocytes. Therefore, it can be suggested that thymus derived melatonin protects thymic T-cells from testosterone induced seasonal oxidative stress, apoptosis and also acts as a potent paracrine factor for maintenance of redox status to ensure thymocyte survival. Copyright © 2015 Elsevier Inc. All rights reserved.

Treatment results and prognostic indicators in thymic epithelial tumors: a clinicopathological analysis of 45 patients.

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Ansari, Mansour; Dehsara, Farzin; Mohammadianpanah, Mohammad; Mosalaei, Ahmad; Omidvari, Shapour; Ahmadloo, Niloofar

2014-07-01

Thymomas are rare epithelial tumors arising from thymus gland. This study aims at investigating the clinical presentation, prognostic factors and treatment outcome of forty five patients with thymoma and thymic carcinoma. Forty-five patients being histologically diagnosed with thymoma or thymic carcinoma that were treated and followed-up at a tertiary academic hospital during January 1987 and December 2008 were selected for the present study. Twelve patients were solely treated with surgery, 14 with surgery followed by adjuvant radiotherapy, 12 with sequential combined treatment of surgery, radiotherapy and/or chemotherapy and 7 with non-surgical approach including radiotherapy and/or chemotherapy.  Tumors were classified based on the new World Health Organization (WHO) histological classification. There were 18 women and 27 men with a median age of 43 years. Twelve patients (26.7%) had stage I, 7 (17.8%) had stage II, 23 (51%) had stage III and 2 (4.5%) had stage IV disease. Tumors types were categorized as type A (n=4), type AB (n=10), type B1 (n=9), type B2 (n=10), type B3 (n=5) and type C (n=7). In univariate analysis for overall survival, disease stage (P=0.001), tumor size (P=0.017) and the extent of surgical resection (P<0.001) were prognostic factors. Regarding the multivariate analysis, only the extent of the surgical resection (P<0.001) was the independent prognostic factor and non-surgical treatment had a negative influence on the survival. The 5-year and 10-year overall survival rates were 70.8% and 62.9%, respectively. Complete surgical resection is the most important prognostic factor in patients with thymic epithelial tumors.

Utility of Electrocardiography (ECG)-Gated Computed Tomography (CT) for Preoperative Evaluations of Thymic Epithelial Tumors.

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Ozawa, Yoshiyuki; Hara, Masaki; Nakagawa, Motoo; Shibamoto, Yuta

2016-01-01

Preoperative evaluation of invasion to the adjacent organs is important for the thymic epithelial tumors on CT. The purpose of our study was to evaluate the utility of electrocardiography (ECG)-gated CT for assessing thymic epithelial tumors with regard to the motion artifacts produced and the preoperative diagnostic accuracy of the technique. Forty thymic epithelial tumors (36 thymomas and 4 thymic carcinomas) were examined with ECG-gated contrast-enhanced CT using a dual source scanner. The scan delay after the contrast media injection was 30 s for the non-ECG-gated CT and 100 s for the ECG-gated CT. Two radiologists blindly evaluated both the non-ECG-gated and ECG-gated CT images for motion artifacts and determined whether the tumors had invaded adjacent structures (mediastinal fat, superior vena cava, brachiocephalic veins, aorta, pulmonary artery, pericardium, or lungs) on each image. Motion artifacts were evaluated using a 3-grade scale. Surgical and pathological findings were used as a reference standard for tumor invasion. Motion artifacts were significantly reduced for all structures by ECG gating ( p =0.0089 for the lungs and p ECG-gated CT and ECG-gated CT demonstrated 79% and 95% accuracy, respectively, during assessments of pericardial invasion ( p =0.03). ECG-gated CT reduced the severity of motion artifacts and might be useful for preoperative assessment whether thymic epithelial tumors have invaded adjacent structures.

Thymic hyperplasia in a patient with Grave's disease

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Hamzaoui Amira A

2012-02-01

Full Text Available Abstract Hyperplastic changes of the thymus may be found in patients with Graves' disease. However, this rarely presents as an anterior mediastinal mass, particularly among adults. In this report, we describe a 46-year old woman with Graves' disease and thymic hyperplasia.

Phenotypic characterization of thymic prelymphoma cells of B10 mice treated with split-dose irradiation

International Nuclear Information System (INIS)

Muto, M.; Kubo, E.; Kamisaku, H.; Sado, T.

1990-01-01

Using an intrathymic injection assay on B10 Thy-1 congenic mice, it was demonstrated that thymic prelymphoma cells first developed within the thymuses from 4 to 8 days after split-dose irradiation and were detected in more than 63% of the test donor thymuses when examined at 21 and 31 days after irradiation. Moreover, some mice (25%) at 2 mo after split-dose irradiation had already developed thymic lymphomas in their thymuses. To characterize these thymic prelymphoma cells, the thymocytes from B10 Thy-1.1 mice 1 mo after irradiation were stained with anti-CD4 and anti-CD8 mAb and were sorted into four subpopulations. These fractionated cells were injected into the recipient thymuses to examine which subpopulation contained thymic prelymphoma cells. The results indicated that thymic prelymphoma cells existed mainly in CD4- CD8- and CD4- CD8+ thymocyte subpopulations and also in CD4+ CD8+ subpopulation. T cell lymphomas derived from CD4- CD8- prelymphoma cells had mainly CD4- CD8- or CD4- CD8+ phenotypes. T cell lymphomas developed from CD4- CD8+ prelymphoma cells mainly expressed CD4- CD8+ or CD4+ CD8+ phenotype. T cell lymphomas originating from CD4+ CD8+ prelymphoma cells were mainly CD4+ CD8+ but some CD4- CD8+ or CD4+ CD8- cells were also present. These thymic prelymphoma cells were further characterized phenotypically in relation to their expression of the marker defined by the mAb against J11d marker and TL-2 (thymus-leukemia) Ag, which is not expressed on normal thymocytes of B10.Thy-1.2 or B10.Thy-1.1 strain, but appears on the thymocytes of lymphomagenic irradiated mice. The results indicated that the prelymphoma cells existed in J11d+, TL-2+ cells

Plxnd1 expression in thymocytes regulates their intrathymic migration while that in thymic endothelium impacts medullary topology

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Young Il Choi

2013-11-01

Full Text Available An important role for plexinD1 in thymic development is inferred from studies of germline Plxnd1 knockout (KO mice where mislocalized CD69+ thymocytes as well as ectopic thymic subcapsular medullary structures were observed. Given embryonic lethality of the Plxnd1-/- genotype, fetal liver transplantation was employed in these prior analyses. Such embryonic hematopoietic reconstitution may have transferred Plxnd1 KO endothelial and/or epithelial stem cells in addition to Plxnd1 KO lymphoid progenitors, thereby contributing to that phenotype. Here we use Plxnd1flox/flox mice crossed to pLck-Cre, pKeratin14-Cre or pTek-Cre transgenic animals to create cell-type specific conditional knockout (CKO lines involving thymocytes (D1ThyCKO, thymic epithelium (D1EpCKO and thymic endothelium (D1EnCKO, respectively. These CKOs allowed us to directly assess the role of plexinD1 in each lineage. Loss of plexinD1 expression on double positive (DP thymocytes leads to their aberrant migration and cortical retention after TCR-mediated positive selection. In contrast, ectopic medulla formation is a consequence of loss of plexinD1 expression on endothelial cells, in turn linked to dysregulation of thymic angiogenesis. D1EpCKO thymi manifest neither abnormality. Collectively, our findings underscore the non-redundant roles for plexinD1 on thymocytes and endothelium, including the dynamic nature of medulla formation resulting from crosstalk between these thymic cellular components.

Effect of granulocyte colony-stimulating factor on murine thymic emigration and subsets reconstitution after a sublethal dose of irradiation

International Nuclear Information System (INIS)

Zhao Hongxia; Guo Mei; Sun Xuedong; Ai Huisheng

2011-01-01

Objective: To investigate the effects of recombinant human granulocyte colony stimulating factor (G-CSF) on murine thymic emigration and subsets reconstitution after a sublethal dose of irradiation. Methods: Female BALB/c mice were irradiated with a 6.0 Gy of γ-ray total-body irradiation and then randomly divided into GCSF group and control group. For mice in the GCSF group, recombinant human G-CSF 100 μg · kg -1 · d -1 was injected subcutaneously once daily for 14 continuous days and mice in the control group were given the same volume of phosphate buffered solution (PBS). At 7, 14, 21 and 28 days later, mice were killed and thymus mononuclear cell suspension were analyzed by flow cytometry for the percentage of the four stages of thymic CD4 - CD8 - double negative cells (DN1-4) and the CD4 + CD8 + double positive ( CD4 + CD8 + DP), CD4 + CD8 - single positive (CD4 + SP), CD4 - CD8 + single positive cells (CD8 + SP).Real-time PCR was used for detection and quantitation of murine T cell receptor rearrangement excision circles (sjTRECs) of the thymic cells of 30 and 60 d after irradiation. Results: The percentage of thymic DN1 cells in GCSF group was significantly higher than that of the control group 7 d after irradiation (t=9.59, P<0.05). 21 d later, the proportion of thymic DN3 and DN4 cells were higher than those of the control group (t=16.37, 7.6, P<0.05). The percentage of thymic CD4 + CD8 + DP cells decreased 7 d after irradiation,increased at 14 d, decreased again at 21 days,and then got a permanent recover. The percentage of thymic CD4 + CD8 + DP cells in the GCSF group recovered to normal and was significantly higher than that of the control group 28 days after irradiation (t=12.22, P<0.05). The percentage of thymic CD8 + SP cells of the GCSF group was significantly higher than that of the control group 21 d after irradiation (t=3.77, P<0.05), while G-CSF had no obvious influence on the percentage of the thymic CD4 + SP cells. The sjTRECs copies in the

S1P lyase in thymic perivascular spaces promotes egress of mature thymocytes via up-regulation of S1P receptor 1.

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Maeda, Yasuhiro; Yagi, Hideki; Takemoto, Kana; Utsumi, Hiroyuki; Fukunari, Atsushi; Sugahara, Kunio; Masuko, Takashi; Chiba, Kenji

2014-05-01

Sphingosine 1-phosphate (S1P) and S1P receptor 1 (S1P1) play an important role in the egress of mature CD4 or CD8 single-positive (SP) thymocytes from the thymus. Fingolimod hydrochloride (FTY720), an S1P1 functional antagonist, induced significant accumulation of CD62L(high)CD69(low) mature SP thymocytes in the thymic medulla. Immunohistochemical staining using anti-S1P1 antibody revealed that S1P1 is predominantly expressed on thymocytes in the thymic medulla and is strongly down-regulated even at 3h after FTY720 administration. 2-Acetyl-4-tetrahydroxybutylimidazole (THI), an S1P lyase inhibitor, also induced accumulation of mature SP thymocytes in the thymic medulla with an enlargement of the perivascular spaces (PVS). At 6h after THI administration, S1P1-expressing thymocytes reduced partially as if to form clusters and hardly existed in the proximity of CD31-expressing blood vessels in the thymic medulla, suggesting S1P lyase expression in the cells constructing thymic medullary PVS. To determine the cells expressing S1P lyase in the thymus, we newly established a mAb (YK19-2) specific for mouse S1P lyase. Immunohistochemical staining with YK19-2 revealed that S1P lyase is predominantly expressed in non-lymphoid thymic stromal cells in the thymic medulla. In the thymic medullary PVS, S1P lyase was expressed in ER-TR7-positive cells (reticular fibroblasts and pericytes) and CD31-positive vascular endothelial cells. Our findings suggest that S1P lyase expressed in the thymic medullary PVS keeps the tissue S1P concentration low around the vessels and promotes thymic egress via up-regulation of S1P1.

nab-Paclitaxel in Combination with Carboplatin for a Previously Treated Thymic Carcinoma

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Go Makimoto

2014-01-01

Full Text Available We present the case of a 40-year-old man with previously treated thymic carcinoma, complaining of gradually worsening back pain. Computed tomography scans of the chest showed multiple pleural disseminated nodules with a pleural effusion in the right thorax. The patient was treated with carboplatin on day 1 plus nab-paclitaxel on day 1 and 8 in cycles repeated every 4 weeks. Objective tumor shrinkage was observed after 4 cycles of this regimen. In addition, the elevated serum cytokeratin 19 fragment level decreased, and the patient's back pain was relieved without any analgesics. Although he experienced grade 4 neutropenia and granulocyte colony-stimulating factor (G-CSF injection, the severity of thrombocytopenia and nonhematological toxicities such as reversible neuropathy did not exceed grade 1 during the treatment. To our knowledge, this is the first report to demonstrate the efficacy of combination chemotherapy consisting of carboplatin and nab-paclitaxel against thymic carcinoma. This case report suggests that nab-paclitaxel in combination with carboplatin can be a favorable chemotherapy regimen for advanced thymic carcinoma.

Histogram analysis of apparent diffusion coefficient maps for assessing thymic epithelial tumours: correlation with world health organization classification and clinical staging.

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Kong, Ling-Yan; Zhang, Wei; Zhou, Yue; Xu, Hai; Shi, Hai-Bin; Feng, Qing; Xu, Xiao-Quan; Yu, Tong-Fu

2018-04-01

To investigate the value of apparent diffusion coefficients (ADCs) histogram analysis for assessing World Health Organization (WHO) pathological classification and Masaoka clinical stages of thymic epithelial tumours. 37 patients with histologically confirmed thymic epithelial tumours were enrolled. ADC measurements were performed using hot-spot ROI (ADC HS-ROI ) and histogram-based approach. ADC histogram parameters included mean ADC (ADC mean ), median ADC (ADC median ), 10 and 90 percentile of ADC (ADC 10 and ADC 90 ), kurtosis and skewness. One-way ANOVA, independent-sample t-test, and receiver operating characteristic were used for statistical analyses. There were significant differences in ADC mean , ADC median , ADC 10 , ADC 90 and ADC HS-ROI among low-risk thymoma (type A, AB, B1; n = 14), high-risk thymoma (type B2, B3; n = 9) and thymic carcinoma (type C, n = 14) groups (all p-values histogram analysis may assist in assessing the WHO pathological classification and Masaoka clinical stages of thymic epithelial tumours. Advances in knowledge: 1. ADC histogram analysis could help to assess WHO pathological classification of thymic epithelial tumours. 2. ADC histogram analysis could help to evaluate Masaoka clinical stages of thymic epithelial tumours. 3. ADC 10 might be a promising imaging biomarker for assessing and characterizing thymic epithelial tumours.

Bone marrow-derived thymic antigen-presenting cells determine self-recognition of Ia-restricted T lymphocytes

International Nuclear Information System (INIS)

Longo, D.L.; Kruisbeek, A.M.; Davis, M.L.; Matis, L.A.

1985-01-01

The authors previously have demonstrated that in radiation-induced bone marrow chimeras, T-cell self-Ia restriction specificity appeared to correlate with the phenotype of the bone marrow-derived antigen-presenting (or dendritic) cell in the thymus during T-cell development. However, these correlations were necessarily indirect because of the difficulty in assaying thymic function directly by adult thymus transplant, which has in the past been uniformly unsuccessful. They now report success in obtaining functional T cells from nude mice grafted with adult thymuses reduced in size by treatment of the thymus donor with anti-thymocyte globulin and cortisone. When (B10 Scn X B10.D2)F1 nude mice (I-Ab,d) are given parental B10.D2 (I-Ad) thymus grafts subcutaneously, their T cells are restricted to antigen recognition in association with I-Ad gene products but not I-Ab gene products. Furthermore, thymuses from (B10 X B10.D2)F1 (I-Ab,d)----B10 (I-Ab) chimeras transplanted 6 months or longer after radiation (a time at which antigen-presenting cell function is of donor bone marrow phenotype) into (B10 X B10.D2)F1 nude mice generate T cells restricted to antigen recognition in association with both I-Ad and I-Ab gene products. Thymuses from totally allogeneic bone marrow chimeras appear to generate T cells of bone marrow donor and thymic host restriction specificity. Thus, when thymus donors are radiation-induced bone marrow chimeras, the T-cell I-region restriction of the nude mice recipients is determined at least in part by the phenotype of the bone marrow-derived thymic antigen presenting cells or dendritic cells in the chimeric thymus

Treatment Results and Prognostic Indicators in Thymic Epithelial Tumors: A Clinicopathological Analysis of 45 Patients

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Mansour Ansari

2014-07-01

Full Text Available Background: Thymomas are rare epithelial tumors arising from thymus gland. This study aims at investigating the clinical presentation, prognostic factors and treatment outcome of forty five patients with thymoma and thymic carcinoma. Methods: Forty-five patients being histologically diagnosed with thymoma or thymic carcinoma that were treated and followed-up at a tertiary academic hospital during January 1987 and December 2008 were selected for the present study. Twelve patients were solely treated with surgery, 14 with surgery followed by adjuvant radiotherapy, 12 with sequential combined treatment of surgery, radiotherapy and/or chemotherapy and 7 with non-surgical approach including radiotherapy and/or chemotherapy. Tumors were classified based on the new World Health Organization (WHO histological classification. Results: There were 18 women and 27 men with a median age of 43 years. Twelve patients (26.7% had stage I, 7 (17.8% had stage II, 23 (51% had stage III and 2 (4.5% had stage IV disease. Tumors types were categorized as type A (n=4, type AB (n=10, type B1 (n=9, type B2 (n=10, type B3 (n=5 and type C (n=7. In univariate analysis for overall survival, disease stage (P=0.001, tumor size (P=0.017 and the extent of surgical resection (P<0.001 were prognostic factors. Regarding the multivariate analysis, only the extent of the surgical resection (P<0.001 was the independent prognostic factor and non-surgical treatment had a negative influence on the survival. The 5-year and 10-year overall survival rates were 70.8% and 62.9%, respectively. Conclusion: Complete surgical resection is the most important prognostic factor in patients with thymic epithelial tumors.

Thymic masses: A radiological review | Mittal | SA Journal of Radiology

African Journals Online (AJOL)

Abstract. Various thymic masses and their normal variations have different pathological and management consequences. Radiologists and clinicians should be aware of these entities so that appropriate and timely treatment can be given.

Abnormalities of thymic stroma may contribute to immune dysregulation in murine models of leaky severe combined immunodeficiency

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Francesca eRucci

2011-05-01

Full Text Available Lymphostromal cross-talk in the thymus is essential to allow generation of a diversified repertoire of T lymphocytes and to prevent autoimmunity by self-reactive T cells. Hypomorphic mutations in genes that control T cell development have been associated with immunodeficiency and immune dysregulation both in humans and in mice. We have studied T cell development and thymic stroma architecture and maturation in two mouse models of leaky SCID, carrying hypomorphic mutations in Rag1 and Lig4 genes. Defective T cell development was associated with abnormalities of thymic architecture that predominantly affect the thymic medulla, with reduction of the pool of mature medullary thymic epithelial cells (mTECs. While the ability of mTECs to express Aire is preserved in mutant mice, the frequency of mature mTECs expressing Aire and tissue-specific antigens (TSAs is severely reduced. Similarly, the ability of CD4+ T cells to differentiate into Foxp3+ natural regulatory T cells is preserved in Rag1 and Lig4 mutant mice, but their number is greatly reduced. These data indicate that hypomorphic defects in T cell development may cause defective lymphostromal cross-talk and impinge on thymic stromal cells maturation, and thus favor immune dysregulation.

FOXN1: a master regulator gene of thymic epithelial development programme

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Rosa eRomano

2013-07-01

Full Text Available T cell ontogeny is a sophisticated process, which takes place within the thymus through a series of well-defined discrete stages. The process requires a proper lympho-stromal interaction. In particular, cortical and medullary thymic epithelial cells (cTECs, mTECs drive T cell differentiation, education and selection processes, while the thymocyte-dependent signals allow TECs to maturate and provide an appropriate thymic microenvironment. Alterations in genes implicated in thymus organogenesis, including Tbx1, Pax1, Pax3, Pax9, Hoxa3, Eya1 and Six1, affect this well-orchestrated process, leading to disruption of thymic architecture. Of note, in both human and mice, the primordial TECs are yet unable to fully support T cell development and only after the transcriptional activation of the Forkhead-box n1 (FOXN1 gene in the thymic epithelium this essential function is acquired. FOXN1 is a master regulator in the TEC lineage specification in that it down-stream promotes transcription of genes, which, in turn, regulate TECs differentiation. In particular, FOXN1 mainly regulates TEC patterning in the fetal stage and TEC homeostasis in the postnatal thymus. An inborn null mutation in FOXN1 leads to Nude/SCID phenotype in mouse, rat and humans. In Foxn1-/- nude animals, initial formation of the primordial organ is arrested and the primordium is not colonized by hematopoietic precursors, causing a severe primary T cell immunodeficiency. In humans, the Nude/SCID phenotype is characterized by congenital alopecia of the scalp, eyebrows, and eyelashes, nail dystrophy and a severe T cell immunodeficiency, inherited as an autosomal recessive disorder. Aim of this review is to summarize all the scientific information so far available to better characterize the pivotal role of the master regulator FOXN1 transcription factor in the TEC lineage specifications and functionality.

Different mechanisms for the resistance of C3H and STS strain mice to the development of thymic lymphomas following fractionated whole-body irradiation

International Nuclear Information System (INIS)

Aizawa, Shiro; Kamisaku, Hitoko

1999-01-01

B10 strain mice are extremely susceptible for induction of thymic lymphomas by fractionated whole-body irradiation (FI), whereas C3H and STS mice are fairly resistant. In the present study, we constructed radiation bone marrow chimeras in the reciprocal donor-host combinations of susceptible and resistant mice with use of Thy1 markers that allow to determine genetic origins of donor- and host-type thymocytes, and then to analyze the influence of host/thymic environment on the strain-dependent susceptibility to thymic lymphomagenesis. B10.Thy1.1→C3H, B10.Thy1.1→STS as well as B10.Thy1.1→B10 bone marrow chimeras manifested a high incidence of thymic lymphomas after FI-treatment, whereas C3H. Thy1.1→B10 and STS→B10 as well as C3H→C3H and STS→STS chimeras manifested a low incidence of thymic lymphoma. Furthermore, FI-treatment of [B10.Thy1.1+C3H]→B10 mixed chimeras resulted in the generation of similar numbers of thymic lymphomas of B10 and C3H origins, whereas FI-treatment of [B10.Thy1.1+STS]→B10 mixed chimeras preferentially induced thymic lymphomas of B10 origin. These results indicated that host environments of C3H and STS resistant mice are not inhibitory for the development of thymic lymphomas, genetic factors responsible for the strain-dependent susceptibility and/or resistance to FI-induced lymphomagenesis exert their effects entirely on bone-marrow derived cells, and the resistance of STS mice to FI-induced thymic lymphomagenesis is an intrinsic property of thymocytes as the targets of thymic lymphoma induction, whereas bone marrow-derived thymic stroma cells seem to play a significant role in the resistance of C3H mice for the induction of thymic lymphomas. (author)

Radiotherapy for invasive thymoma and thymic carcinoma. Clinicopathological review

International Nuclear Information System (INIS)

Mayer, R.; Stuecklschweiger, G.F.; Prettenhofer, U.; Stranzl, H.; Hackl, A.; Beham-Schmid, C.; Groell, R.; Smolle-Juettner, F.M.; Renner, H.; Quehenberger, F.

1999-01-01

All 33 patients were irradiated with a mean dose of 50 Gy after complete resection (16 patients), partial resection (9 patients) of biopsy (8 patients). Staging was done according to the Masaoka classification; there were 12 Stage II, 12 Stage III and 9 Stage IV patients. Results: In patients with invasive thymoma Stage II to IV (median follow-up 54.4 months) Kaplan-Meier estimates of overall survival (OS), disease-specific (DSS) and disease-free survival (DFS) at 5 years were 63.7% (95% confidence interval [CI], 42 to 84%), 88.3% (CI, 75 to 100%) and 77,4% (CI, 58 to 95%), respectively. Among the prognostic factors tested, such as age, myasthenia gravis, completeness of surgery and histologic subclassification, total radiation dose, and Masaoka Stage, the latter was the only significant predictor of improved survival (p=0.04). Considering local control, radiation dose was a significant prognostic factor (p=0.0006). In patients with thymic carcinoma (median follow-up 43.4 months) 5 year DSS, and DFS were 22.2% (CI, 0 to 60%) and 16.7% (CI, 0 to 46%), respectively. Thymoma as compared to thymic carcinoma had a statistically significant better DSS (p=0.007) and DFS (p=0.0007). Conclusion: Postoperative radiotherapy with sufficient doses plays an important role as adjuvant treatment in complete or incomplete resected invasive Stage II to III thymoma. In unresectable thymoma Stage III to IV as well as in thymic carcinoma a multimodality approach should be considered to improve survival. (orig.) [de

Ventricular arrhythmia burst is an independent indicator of larger infarct size even in optimal reperfusion in STEMI

NARCIS (Netherlands)

van der Weg, Kirian; Majidi, Mohamed; Haeck, Joost D. E.; Tijssen, Jan G. P.; Green, Cynthia L.; Koch, Karel T.; Kuijt, Wichert J.; Krucoff, Mitchell W.; Gorgels, Anton P. M.; de Winter, Robbert J.

2016-01-01

We hypothesized that ventricular arrhythmia (VA) bursts during reperfusion phase are a marker of larger infarct size despite optimal epicardial and microvascular perfusion. 126 STEMI patients were studied with 24h continuous, 12-lead Holter monitoring. Myocardial blush grade (MBG) was determined and

Can a Proper T-Cell Development Occur in an Altered Thymic Epithelium? Lessons From EphB-Deficient Thymi

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Juan José Muñoz

2018-04-01

Full Text Available For a long time, the effects of distinct Eph tyrosine kinase receptors and their ligands, ephrins on the structure, immunophenotype, and development of thymus and their main cell components, thymocytes (T and thymic epithelial cells (TECs, have been studied. In recent years, the thymic phenotype of mutant mice deficient in several Ephs and ephrins B has been determined. Remarkably, thymic stroma in these animals exhibits important defects that appear early in ontogeny but little alterations in the proportions of distinct lymphoid cell populations. In the present manuscript, we summarize and extend these results discussing possible mechanisms governing phenotypical and functional thymocyte maturation in an absence of the critical T–TEC interactions, concluding that some signaling mediated by key molecules, such as MHCII, CD80, β5t, Aire, etc. could be sufficient to enable a proper maturation of thymocytes, independently of morphological alterations affecting thymic epithelium.

A stromal myoid cell line provokes thymic erythropoiesis between ...

African Journals Online (AJOL)

Background: The thymus provides an optimal cellular and humoral microenvironment for cell line committed differentiation of haematopoietic stem cells. The immigration process requires the secretion of at least one peptide called thymotaxine by cells of the reticulo-epithelial (RE) network of the thymic stromal cellular ...

Reactive thymic hyperplasia following treatment of ACTH-producing tumors

International Nuclear Information System (INIS)

Schmidt, S.; Klose, K.J.; Iwinska-Zelder, J.; Frank, M.; Ehlenz, K.; Kisker, O.

1997-01-01

Surgical or conservative treatment of ACTH-producing tumors results in acute drop of the previously excessively high cortisol levels. The following associated pathophysiological changes also occur in the organism's recovery from stress, such as trauma, operation or chemotherapy of tumors. Both cases result in a regeneration of the immune system, which might even be exalted. The corresponding radiographic feature is the 'rebound' enlargement of the thymus occuring about six months after remission of hypercortisolism. Histological examination reveals benign thymus hyperplasia. Especially in cases of still unkown primary tumor the apperance of this anterior mediastinal mass can lead to misdiagnosis. We present the cases of two patients with diffuse thymic hyperplasia following surgical and medical correction of hypercortisolism. One patient suffered from classic Cushing's disease responding to transsphenoidal resection of an ACTH-secreting pituitary microadenoma. Six monsths later CT of the chest incidentally demonstrated an anterior mediastinal mass known as thymic hyperplasia. The second patient presented with an ectopic, still unknown source of ACTH-production. (orig./AJ) [de

DKK1 mediated inhibition of Wnt signaling in postnatal mice leads to loss of TEC progenitors and thymic degeneration.

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Masako Osada

2010-02-01

Full Text Available Thymic epithelial cell (TEC microenvironments are essential for the recruitment of T cell precursors from the bone marrow, as well as the subsequent expansion and selection of thymocytes resulting in a mature self-tolerant T cell repertoire. The molecular mechanisms, which control both the initial development and subsequent maintenance of these critical microenvironments, are poorly defined. Wnt signaling has been shown to be important to the development of several epithelial tissues and organs. Regulation of Wnt signaling has also been shown to impact both early thymocyte and thymic epithelial development. However, early blocks in thymic organogenesis or death of the mice have prevented analysis of a role of canonical Wnt signaling in the maintenance of TECs in the postnatal thymus.Here we demonstrate that tetracycline-regulated expression of the canonical Wnt inhibitor DKK1 in TECs localized in both the cortex and medulla of adult mice, results in rapid thymic degeneration characterized by a loss of DeltaNP63(+ Foxn1(+ and Aire(+ TECs, loss of K5K8DP TECs thought to represent or contain an immature TEC progenitor, decreased TEC proliferation and the development of cystic structures, similar to an aged thymus. Removal of DKK1 from DKK1-involuted mice results in full recovery, suggesting that canonical Wnt signaling is required for the differentiation or proliferation of TEC populations needed for maintenance of properly organized adult thymic epithelial microenvironments.Taken together, the results of this study demonstrate that canonical Wnt signaling within TECs is required for the maintenance of epithelial microenvironments in the postnatal thymus, possibly through effects on TEC progenitor/stem cell populations. Downstream targets of Wnt signaling, which are responsible for maintenance of these TEC progenitors may provide useful targets for therapies aimed at counteracting age associated thymic involution or the premature thymic

A thymic neuroendocrine tumour in a young female: a rare cause of relapsing and remitting Cushing's syndrome.

Science.gov (United States)

Trott, M J; Farah, G; Stokes, V J; Wang, L M; Grossman, A B

2016-01-01

We present a case of a young female patient with a rare cause of relapsing and remitting Cushing's syndrome due to ectopic ACTH secretion from a thymic neuroendocrine tumour. A 34-year-old female presented with a constellation of symptoms of Cushing's syndrome, including facial swelling, muscle weakness and cognitive impairment. We use the terms 'relapsing and remitting' in this case report, given the unpredictable time course of symptoms, which led to a delay of 2 years before the correct diagnosis of hypercortisolaemia. Diagnostic workup confirmed ectopic ACTH secretion, and a thymic mass was seen on mediastinal imaging. The patient subsequently underwent thymectomy with complete resolution of her symptoms. Several case series have documented the association of Cushing's syndrome with thymic neuroendocrine tumours (NETs), although to our knowledge there are a few published cases of patients with relapsing and remitting symptoms. This case is also notable for the absence of features of the MEN-1 syndrome, along with the female gender of our patient and her history of non-smoking. Ectopic corticotrophin (ACTH) secretion should always be considered in the diagnostic workup of young patients with Cushing's syndromeThere is a small but growing body of literature describing the correlation between ectopic ACTH secretion and thymic neuroendocrine tumours (NETs)The possibility of a MEN-1 syndrome should be considered in all patients with thymic NETs, and we note the observational association with male gender and cigarette smoking in this cohortAn exception to these associations is the finding of relatively high incidence of thymic NETs among female non-smoking MEN-1 patients in the Japanese compared with Western populationsThe relapsing and remitting course of our patient's symptoms is noteworthy, given the paucity of this finding among other published cases.

A case of congenital Langerhans cell histiocytosis with skin and thymic lesions: Exploring the prognostic value of thymus involvement

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M.M. Escudero-Góngora

2016-10-01

Full Text Available Thymus evaluation is not included in the guidelines of the Histiocyte Society, so its prevalence, management and prognosis are not well established. We present a newborn with self-healing cutaneous LCH and thymic involvement that was evaluated with a thoracic ultrasound. With the current evidence we are unable to predict the prognosis of the thymus association in neonatal LCH. We suggest that performing thymic ultrasound study, which is a non-invasive technique, would allow us to know the incidence of thymic involvement and its role on prognosis.

Tissue-resident natural killer (NK) cells are cell lineages distinct from thymic and conventional splenic NK cells

Science.gov (United States)

Sojka, Dorothy K; Plougastel-Douglas, Beatrice; Yang, Liping; Pak-Wittel, Melissa A; Artyomov, Maxim N; Ivanova, Yulia; Zhong, Chao; Chase, Julie M; Rothman, Paul B; Yu, Jenny; Riley, Joan K; Zhu, Jinfang; Tian, Zhigang; Yokoyama, Wayne M

2014-01-01

Natural killer (NK) cells belong to the innate immune system; they can control virus infections and developing tumors by cytotoxicity and producing inflammatory cytokines. Most studies of mouse NK cells, however, have focused on conventional NK (cNK) cells in the spleen. Recently, we described two populations of liver NK cells, tissue-resident NK (trNK) cells and those resembling splenic cNK cells. However, their lineage relationship was unclear; trNK cells could be developing cNK cells, related to thymic NK cells, or a lineage distinct from both cNK and thymic NK cells. Herein we used detailed transcriptomic, flow cytometric, and functional analysis and transcription factor-deficient mice to determine that liver trNK cells form a distinct lineage from cNK and thymic NK cells. Taken together with analysis of trNK cells in other tissues, there are at least four distinct lineages of NK cells: cNK, thymic, liver (and skin) trNK, and uterine trNK cells. DOI: http://dx.doi.org/10.7554/eLife.01659.001 PMID:24714492

A pediatric case of life-threatening airway obstruction caused by a cervicomediastinal thymic cyst

Energy Technology Data Exchange (ETDEWEB)

Komura, Makoto; Kanamori, Yutaka; Sugiyama, Masahiko; Iwanaka, Tadashi [University of Tokyo Hospital, Department of Pediatric Surgery, Tokyo (Japan); Fukushima, Noriyoshi [University of Tokyo Hospital, Department of Pathology, Tokyo (Japan)

2010-09-15

Most patients with thymic cysts complain of a slowly enlarging, asymptomatic cervical mass. Only 6-10% suffer dysphagia, dyspnoea, stridor, cervical pain or vocal paralysis. In some rare cases sudden onset of severe dyspnoea or asphyxia is the first symptom, especially in neonates and small infants. We report a unique case of a 20-month-old child, who required emergency tracheal intubation due to asphyxia. Cervicomediastinal thymic cyst might need to be included in causes of life-threatening airway obstruction in young children. (orig.)

Expression of tyrosine kinase gene in mouse thymic stromal cells

NARCIS (Netherlands)

Rinke de Wit, T. F.; Izon, D. J.; Revilla, C.; Oosterwegel, M.; Bakker, A. Q.; van Ewijk, W.; Kruisbeek, A. M.

1996-01-01

Amongst the most important signal transduction molecules involved in regulating growth and differentiation are the protein tyrosine kinases (PTK). Since T cell development is a consequence of interactions between thymic stromal cells (TSC) and thymocytes, identification of the PTK in both

The molecular biology of radiation-induced carcinogenesis: thymic lymphoma, myeloid leukaemia and osteosarcoma

Energy Technology Data Exchange (ETDEWEB)

Janowski, M [Centre d' Etude de l' Energie Nucleaire, Mol (Belgium); Cox, R [Medical Research Council, Harwell (UK). Radiobiological Research Unit; Strauss, P G [GSF, Neuherberg (Germany, F.R.). Abt. fuer Molekulare Zellpathologie

1990-04-01

In mice, external X- or {gamma}-irradiation may induce thymic lymphomas or myeloid leukaemias, while bone-seeking {alpha}-emitters may induce osteosarcomas, and to a lesser extent acute myeloid leukaemia. The paper reviews briefly some experimental data in respect to molecular mechanisms underlying these radio-carcinogenic processes. Thymic lymphomagenesis proceeds by an indirect mechanism in which recombinant proviruses could be involved. Myeloid leukaemogenesis is characterized by a very early putative initiating event, consisting of non-random rearrangements and/or deletions of chromosome 2. Osteosarcomagenesis in mice is often associated with the expression of proviruses, and the tumors often contain somatically acquired proviruses. (UK).

Weapons make the man (larger: formidability is represented as size and strength in humans.

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Daniel M T Fessler

Full Text Available In order to determine how to act in situations of potential agonistic conflict, individuals must assess multiple features of a prospective foe that contribute to the foe's resource-holding potential, or formidability. Across diverse species, physical size and strength are key determinants of formidability, and the same is often true for humans. However, in many species, formidability is also influenced by other factors, such as sex, coalitional size, and, in humans, access to weaponry. Decision-making involving assessments of multiple features is enhanced by the use of a single summary variable that encapsulates the contributions of these features. Given both a the phylogenetic antiquity of the importance of size and strength as determinants of formidability, and b redundant experiences during development that underscore the contributions of size and strength to formidability, we hypothesize that size and strength constitute the conceptual dimensions of a representation used to summarize multiple diverse determinants of a prospective foe's formidability. Here, we test this hypothesis in humans by examining the effects of a potential foe's access to weaponry on estimations of that individual's size and strength. We demonstrate that knowing that an individual possesses a gun or a large kitchen knife leads observers to conceptualize him as taller, and generally larger and more muscular, than individuals who possess only tools or similarly mundane objects. We also document that such patterns are not explicable in terms of any actual correlation between gun ownership and physical size, nor can they be explained in terms of cultural schemas or other background knowledge linking particular objects to individuals of particular size and strength. These findings pave the way for a fuller understanding of the evolution of the cognitive systems whereby humans--and likely many other social vertebrates--navigate social hierarchies.

Effects of neonatal thymic exposure to high doses of X-irradiation

International Nuclear Information System (INIS)

Bains, G.S.; Sundaram, K.

1979-01-01

The thymic region of neonatal Swiss mice was exposed to doses varying from 1000 R to 2000 R of X-irradiation. The animals did not show any signs of wasting syndrome up to 6 months after irradiation. At this time hyperplasia of the thymus with an associated lymphocytosis was evident in irradiated animals. Antibody production to sheep red blood cells (SRBC) was not affected. However, at 12 months post-irradiation the animals showed signs of wasting disease with a progressive increase in their numbers at 18 and 24 months of age. The percentage incidence of animals with wasting disease was dose dependent. At this stage in the majority of the animals with the disease the thymus showed varying degrees of atrophy along with splenomegaly. There were no significant differences in the number of lymphocytes but the number of granulocytes showed a substantial increase. This was more evident in animals exposed to 2000 R to the thymic region. Though one observed a lowered ability to form antibodies to bovine serum albumin (BSA) with advancing age, the thymic irradiation did not affect the immune response to BSA even in animals manifesting wasting disease. An interesting observation has been the development of a severe loss of muscle power and tone in the hind limbs in a large majority of animals. (author)

Alteration of T cell function in healthy persons with a history of thymic x irradiation

International Nuclear Information System (INIS)

Rieger, C.H.L.; Kraft, S.C.; Rothberg, R.M.

1975-01-01

The possible late effects of x irradiation to the infantile thymus were investigated by studying immune functions in 12 healthy persons with a history of thymic x irradiation and healthy control subjects. No differences were found in serum immunoglobulin values, humoral antibody levels, lymphocyte counts, and lymphocyte reactivity to phytohemagglutinin, vaccinia virus, purified protein derivative (PPD), and allogeneic cells. The irradiation group exhibited cellular hyperresponsiveness to streptokinase-streptodornase (SK-SD). In contrast, mean skin and in vitro lymphocyte responses to Candida albicans were depressed in the patients with thymic irradiation. A dissociation of these two Candida responses was found in only 1 of 14 healthy control subjects but in 7 of 12 irradiated individuals. While thymic irradiation did not result in impaired immunologic defenses leading to clinical disease, it caused alterations in T cell responses similar to those reported in patients with chronic mucocutaneous candidiasis

Alteration of T cell function in healthy persons with a history of thymic x irradiation

Energy Technology Data Exchange (ETDEWEB)

Rieger, C.H.L.; Kraft, S.C.; Rothberg, R.M.

1975-10-01

The possible late effects of x irradiation to the infantile thymus were investigated by studying immune functions in 12 healthy persons with a history of thymic x irradiation and healthy control subjects. No differences were found in serum immunoglobulin values, humoral antibody levels, lymphocyte counts, and lymphocyte reactivity to phytohemagglutinin, vaccinia virus, purified protein derivative (PPD), and allogeneic cells. The irradiation group exhibited cellular hyperresponsiveness to streptokinase-streptodornase (SK-SD). In contrast, mean skin and in vitro lymphocyte responses to Candida albicans were depressed in the patients with thymic irradiation. A dissociation of these two Candida responses was found in only 1 of 14 healthy control subjects but in 7 of 12 irradiated individuals. While thymic irradiation did not result in impaired immunologic defenses leading to clinical disease, it caused alterations in T cell responses similar to those reported in patients with chronic mucocutaneous candidiasis.

TaGS5-3A, a grain size gene selected during wheat improvement for larger kernel and yield.

Science.gov (United States)

Ma, Lin; Li, Tian; Hao, Chenyang; Wang, Yuquan; Chen, Xinhong; Zhang, Xueyong

2016-05-01

Grain size is a dominant component of grain weight in cereals. Earlier studies have shown that OsGS5 plays a major role in regulating both grain size and weight in rice via promotion of cell division. In this study, we isolated TaGS5 homoeologues in wheat and mapped them on chromosomes 3A, 3B and 3D. Temporal and spatial expression analysis showed that TaGS5 homoeologues were preferentially expressed in young spikes and developing grains. Two alleles of TaGS5-3A, TaGS5-3A-T and TaGS5-3A-G were identified in wheat accessions, and a functional marker was developed to discriminate them. Association analysis revealed that TaGS5-3A-T was significantly correlated with larger grain size and higher thousand kernel weight. Biochemical assays showed that TaGS5-3A-T possesses a higher enzymatic activity than TaGS5-3A-G. Transgenic rice lines overexpressing TaGS5-3A-T also exhibited larger grain size and higher thousand kernel weight than TaGS5-3A-G lines, and the transcript levels of cell cycle-related genes in TaGS5-3A-T lines were higher than those in TaGS5-3A-G lines. Furthermore, systematic evolution analysis in diploid, tetraploid and hexaploid wheat showed that TaGS5-3A underwent strong artificial selection during wheat polyploidization events and the frequency changes of two alleles demonstrated that TaGS5-3A-T was favoured in global modern wheat cultivars. These results suggest that TaGS5-3A is a positive regulator of grain size and its favoured allele TaGS5-3A-T exhibits a larger potential application in wheat high-yield breeding. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

Spleen and thymic sonography as estimator of the immune response in children with repeated infections

International Nuclear Information System (INIS)

Rabaza, Jesus; Fundora, Hermes; Rodriguez, Alexis; Hernandez, Maria de los Angeles

2010-01-01

The spleen is a secondary lymphoid organ. The spleen has many functions: IgM class antibody production and phagocytosis of encapsulated bacteria. We propose to measure the dimensions of the spleen in children with repeated infections, in order to describe them as a diagnosis marker and to explore the probable correlation between the thymic characteristics and the dimensions of the spleen. We study 81 patients that attended the consultation of Immunology from Aballi hospital with repeated infections and they were from 8 months to 9 years old. Children with nutritional value up to the third percentile and those taking steroids 45 days before the study were excluded. We measured the thymic and splenic areas by mediastinal and abdominal echography. The length, the splenic index and the weight are less in patients with repeated infections. These data were significant in 12 to 23 month of age group. The length and the splenic index were less in patients with depletion of thymic area. The sonographic evaluation of the spleen is very important in patients from 1 to 2 years old and in patients with thymic depletion, because they are on the age of vaccine administration according to the Cuban schedule and having affected a main organ for immune response might be a reason for them to show a deficient response and need special schedules

Direct analysis of thymic function in children with Down's syndrome

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Meschiari Liviana

2005-02-01

Full Text Available Abstract Background Down's syndrome (DS is characterized by several immunological defects, especially regarding T cell compartment. DS is considered the best example of accelerated ageing in humans. Direct observations of the thymus have shown that in DS this organ undergoes severe histological and morphological changes. However, no data on its capacity to generate T cells are present in the literature. Here, using a new technology based upon real time PCR, we have investigated the capacity of the thymus to produce and release newly generated T lymphocytes (the so called "recent thymic emigrants", RTE in children with DS. Methods We studied 8 children affected by DS, aged 2–7 years, compared with 8 age- and sex-matched healthy controls. Flow cytometry was used to determine different lymphocytes subsets. Real time PCR with the Taqman system was used to quantify the amount of RTE, i.e. peripheral blood lymphocytes that express the T cell receptor rearrangement excision circles (TREC. Results In comparison with control children, those with DS had a significant lower number of TREC+ peripheral blood cells. Moreover, in DS children but not in controls, a strong negative correlation between age and the levels of TREC+ cells was found. Conclusions The direct measure of thymic output indicates that the impairment of the organ results in a reduced production of newly generated T cells. This observation could suggest that cytokines able to modulate thymic function, such as interleukins, could be useful to improve the functionality of the organ and to treat the immunodeficiency present in DS subjects.

A False Positive I-131 Metastatic Survey Caused by Radioactive Iodine Uptake by a Benign Thymic Cyst

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Avneet K. Singh

2017-01-01

Full Text Available Thyroid carcinoma is the most common endocrine malignancy in the United States with increasing incidence and diagnosis but stable mortality. Differentiated thyroid cancer rarely presents with distant metastases and is associated with a low risk of morbidity and mortality. Despite this, current protocols recommend remnant ablation with radioactive iodine and evaluation for local and distant metastasis in some patients with higher risk disease. There are several case reports of false positive results of metastatic surveys that are either normal physiologic variants or other pathological findings. Most false positive findings are associated with tissue that has physiologic increased uptake of I-131, such as breast tissue or lung tissue; pathological findings such as thymic cysts are also known to have increased uptake. Our case describes a rare finding of a thymic cyst found on a false positive I-131 metastatic survey. The patient was taken for surgical excision and the final pathology was a benign thymic cyst. Given that pulmonary metastases of differentiated thyroid cancer are rare, thymic cysts, though also rare, must be part of the differential diagnosis for false positive findings on an I-131 survey.

MASSIVE GALAXIES ARE LARGER IN DENSE ENVIRONMENTS: ENVIRONMENTAL DEPENDENCE OF MASS–SIZE RELATION OF EARLY-TYPE GALAXIES

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Yoon, Yongmin; Im, Myungshin; Kim, Jae-Woo, E-mail: yymx2@astro.snu.ac.kr, E-mail: mim@astro.snu.ac.kr [Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

2017-01-01

Under the Λ cold dark matter (ΛCDM) cosmological models, massive galaxies are expected to be larger in denser environments through frequent hierarchical mergers with other galaxies. Yet, observational studies of low-redshift early-type galaxies have shown no such trend, standing as a puzzle to solve during the past decade. We analyzed 73,116 early-type galaxies at 0.1 ≤  z  < 0.15, adopting a robust nonparametric size measurement technique and extending the analysis to many massive galaxies. We find for the first time that local early-type galaxies heavier than 10{sup 11.2} M {sub ⊙} show a clear environmental dependence in mass–size relation, in such a way that galaxies are as much as 20%–40% larger in the densest environments than in underdense environments. Splitting the sample into the brightest cluster galaxies (BCGs) and non-BCGs does not affect the result. This result agrees with the ΛCDM cosmological simulations and suggests that mergers played a significant role in the growth of massive galaxies in dense environments as expected in theory.

Mesothelioma and thymic tumors: Treatment challenges in (outside) a network setting.

Science.gov (United States)

Imbimbo, Martina; Maury, Jean-Michel; Garassino, Marina; Girard, Nicolas

2018-02-02

The management of patients with mesothelioma and thymic malignancy requires continuous multidisciplinary expertise at any step of the disease. A dramatic improvement in our knowledge has occurred in the last few years, through the development of databases, translational research programs, and clinical trials. Access to innovative strategies represents a major challenge, as there is a lack of funding for clinical research in rare cancers and their rarity precludes the design of robust clinical trials that could lead to specific approval of drugs. In this context, patient-centered initiatives, such as the establishment of dedicated networks, are warranted. International societies, such as IMIG (International Mesothelioma Interest Group) and ITMIG (International Thymic Malignancy Interest Group) provide infrastructure for global collaboration, and there are many advantages to having strong regional groups working on the same issues. There may be regional differences in risk factors, susceptibility, management and outcomes. The ability to address questions both regionally as well as globally is ideal to develop a full understanding of mesothelioma and thymic malignancies. In Europe, through the integration of national networks with EURACAN, the collaboration with academic societies and international groups, the development of networks in thoracic oncology provides multiplex integration of clinical care and research, ultimately ensuring equal access to high quality care to all patients, with the opportunity of conducting high level clinical and translational research projects. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

Models of Aire-dependent gene regulation for thymic negative selection

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Dina eDanso-Abeam

2011-05-01

Full Text Available Mutations in the Autoimmune Regulator (AIRE gene lead to Autoimmune Polyendocrinopathy Syndrome type 1 (APS1, characterized by the development of multi-organ autoimmune damage. The mechanism by which defects in AIRE result in autoimmunity has been the subject of intense scrutiny. At the cellular level, the working model explains most of the clinical and immunological characteristics of APS1, with AIRE driving the expression of tissue restricted antigens (TRAs in the epithelial cells of the thymic medulla. This TRA expression results in effective negative selection of TRA-reactive thymocytes, preventing autoimmune disease. At the molecular level, the mechanism by which AIRE initiates TRA expression in the thymic medulla remains unclear. Multiple different models for the molecular mechanism have been proposed, ranging from classical transcriptional activity, to random induction of gene expression, to epigenetic tag recognition effect, to altered cell biology. In this review, we evaluate each of these models and discuss their relative strengths and weaknesses.

T-lymphocyte subsets, thymic size and breastfeeding in infancy

DEFF Research Database (Denmark)

Jeppesen, Dorthe Lisbeth; Hasselbalch, Helle; Lisse, Ida M

2004-01-01

We followed the changes in concentration of T-lymphocyte subsets (CD4+ and CD8+ cells) in peripheral blood and thymus size during infancy. Previous studies have found increased thymus size in breastfed infants. The present study analyzed the association between breastfeeding and the number of CD4...

Effects of marrow grafting on preleukemia cells and thymic nurse cells in C57BL/Ka mice after a leukemogenic split-dose irradiation

International Nuclear Information System (INIS)

Defresne, M.P.; Greimers, R.; Lenaerts, P.; Boniver, J.

1986-01-01

A split-dose regimen of whole-body irradiation (4 X 175 rad at weekly intervals) induced thymic lymphomas in C57BL/Ka mice after a latent period of 3-9 months. Meanwhile, preleukemia cells arose in the thymus and bone marrow and persisted until the onset of lymphomas. Simultaneously, thymic lymphopoiesis was impaired; thymocyte numbers were subnormal and thymic nurse cells disappeared in a progressive but irreversible fashion. The depletion of these lymphoepithelial complexes, which are normally involved in the early steps of thymic lymphopoiesis, was related to altered prothymocyte activity in bone marrow and to damaged thymic microenvironment, perhaps as a consequence of the presence of preleukemia cells. The grafting of normal bone marrow cells after irradiation prevented the development of lymphomas. However, marrow reconstitution did not inhibit the induction of preleukemia cells. They disappeared from the thymus during the second part of the latent period. At the same time, thymic lymphopoiesis was restored; thymocytes and nurse cell numbers returned to normal as a consequence of the proliferation of grafted marrow-derived cells within the thymus. The results thus demonstrated an intimate relationship between preleukemia cells and an alteration of thymic lymphopoiesis, which particularly involved the nurse cell microenvironment. Some preleukemia cells in marrow-reconstituted, irradiated mice derived from the unirradiated marrow inoculate. Thus these cells acquired neoplastic potential through a factor present in the irradiated tissues. The nature of this indirect mechanism was briefly discussed

Implantation of cultured thymic fragments in patients with acquired immunodeficiency syndrome

NARCIS (Netherlands)

Danner, S. A.; Schuurman, H. J.; Lange, J. M.; Gmelig Meyling, F. H.; Schellekens, P. T.; Huber, J.; Kater, L.

1986-01-01

Cultured thymic fragments were implanted in one patient with acquired immunodeficiency syndrome (AIDS)-related complex (ARC) and in eight AIDS patients with opportunistic infections (OIs, four patients), Kaposi's sarcoma (KS, two patients), or both (two patients). Thereafter, objective clinical

IL-33 and Thymic Stromal Lymphopoietin in mast cell functions

NARCIS (Netherlands)

Saluja, Rohit; Zoltowska, Anna; Ketelaar, Maria Elizabeth; Nilsson, Gunnar

2016-01-01

Thymic Stromal Lymphopoietin (TSLP) and Interleukin 33 (IL-33) are two cytokines released by cells that are in proximity to our environment, e.g., keratinocytes of the skin and epithelial cells of the airways. Pathogens, allergens, chemicals and other agents induce the release of TSLP and IL-33,

Osseous oligometastases from thymic carcinoma: a case report suggesting the effectiveness of palliative-intent radiotherapy treatment

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Kashima J

2016-02-01

Full Text Available Jumpei Kashima,1 Hirotoshi Horio,1 Yusuke Okuma,1,2 Yukio Hosomi,1 Tsunekazu Hishima3 1Department of Thoracic Oncology and Respiratory Medicine, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan; 2Division of Oncology, Research Center for Medical Sciences, Jikei University School of Medicine, Tokyo, Japan; 3Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan Background: Oligometastasis, a recently proposed concept, is defined as an intermediate state of cancer, between localized and systemic disease, that may be well controlled by local ablative treatment. Thymic carcinoma is a rare cancer with a poor prognosis. A definitive management approach has yet to be confirmed by a high level of evidence.Case presentation: We present the case of a 41-year-old female who underwent curative-intent surgery for a stage III squamous cell carcinoma of the thymus. Bone metastases were detected 1 year later by magnetic resonance imaging. These were treated with palliative-intent radiotherapy. Disease progression has not been observed in more than 15 years since the achievement of complete radiological remission.Conclusion: The treatment outcomes in this and other reported cases suggest that some patients with oligometastatic thymic carcinoma may achieve prolonged survival or even cure with low-dose radiotherapy delivered to the metastases. Keywords: oligometastasis, thymic carcinoma, thymic epithelial tumor, bone metastasis

The diagnosis of thymoma and thymic atrophy in patients with myasthenia gravis; Dignostikk av tymom og thymusatrofi hos pasienter med myasthenia gravis

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Sund, K.K.; Skeie, G.O.; Gilhus, N.E.; Aarli, J.A.; Varhaug, J.E. [Haukeland Sykehus, Bergen (Norway)

1997-11-01

The authors have compared clinical, immunological and radiological data in 20 patients with myasthenia gravis and thymoma and in 21 patients with myasthenia gravis and thymic atrophy. The median age at onset was 54 years in the thymoma group and 63 years in the thymic atrophy group. The severity of the disease was similar in the two groups, and there was no significant difference in the concentration of acetylcholine receptor antibodies. CA antibodies were demonstrated in 17/20 thymoma patients and in 6/21 with thymic atrophy, while 19/20 thymoma patients had antibodies to titin, compared with 9/21 among those with thymic atrophy. The diagnosis and treatment of patients with myasthenia gravis is based upon an evaluation of clinical, immunological and radiological data. 28 refs., 2 tabs.

Intrathymic radioresistant stem cells follow an IL-2/IL-2R pathway during thymic regeneration after sublethal irradiation

International Nuclear Information System (INIS)

Zuniga-Pfluecker, J.C.K.; Kruisbeek, A.M.

1990-01-01

Sublethally irradiated mice undergo thymic regeneration which follows a phenotypic pattern of events similar to that observed during normal fetal development. Thymic regeneration after irradiation is the product of a limited pool of intrathymic radioresistant stem cells undergoing simultaneous differentiation. We show that in this model of T cell development, thymic regeneration follows a pathway in which the IL-2R is transiently expressed on CD4-/CD8- cells. IL-2R expression occurred during the exponential growth period of thymic regeneration, and IL-2R blocking prevented this explosive growth. Flow cytometry analysis revealed that the IL-2R blockade affected primarily the development of the immature CD3-/CD4-/CD8- (triple negative) cells and their ability to generate CD3+/CD4+/CD8+ or CD3+/CD4+/CD8- and CD3+/CD4-/CD8+ thymocytes. Thus, our findings demonstrate that blocking of the IL-2R resulted in an arrest in proliferation and differentiation by intrathymic radioresistant stem cells, indicating that the IL-2/IL-2R pathway is necessary for the expansion of immature triple negative T cells

Anti-Apoptotic Signature in Thymic Squamous Cell Carcinomas - Functional Relevance of Anti-Apoptotic BIRC3 Expression in the Thymic Carcinoma Cell Line 1889c.

Science.gov (United States)

Huang, Bei; Belharazem, Djeda; Li, Li; Kneitz, Susanne; Schnabel, Philipp A; Rieker, Ralf J; Körner, Daniel; Nix, Wilfred; Schalke, Berthold; Müller-Hermelink, Hans Konrad; Ott, German; Rosenwald, Andreas; Ströbel, Philipp; Marx, Alexander

2013-01-01

The molecular pathogenesis of thymomas and thymic carcinomas (TCs) is poorly understood and results of adjuvant therapy are unsatisfactory in case of metastatic disease and tumor recurrence. For these clinical settings, novel therapeutic strategies are urgently needed. Recently, limited sequencing efforts revealed that a broad spectrum of genes that play key roles in various common cancers are rarely affected in thymomas and TCs, suggesting that other oncogenic principles might be important. This made us re-analyze historic expression data obtained in a spectrum of thymomas and thymic squamous cell carcinomas (TSCCs) with a custom-made cDNA microarray. By cluster analysis, different anti-apoptotic signatures were detected in type B3 thymoma and TSCC, including overexpression of BIRC3 in TSCCs. This was confirmed by qRT-PCR in the original and an independent validation set of tumors. In contrast to several other cancer cell lines, the BIRC3-positive TSCC cell line, 1889c showed spontaneous apoptosis after BIRC3 knock-down. Targeting apoptosis genes is worth testing as therapeutic principle in TSCC.

Fate of thymic lymphocytes. [/sup 125/IudR and /sup 3/HTdR tracer studies in mice

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Laissue, J A; Chanana, A D; Cronkite, E P; Joel, D D

1976-01-01

Data are summarized from a number of studies on the fate of thymic lymphocytes. Results are reported from studies in mice in which /sup 125/IudR and /sup 3/HTdR were used as tracers to study the production, maturation, migration, and life span of thymic lymphocytes. It is pointed out that thymus-derived cells constitute the majority of recirculating lymphocytes and that peripheral, differentiated thymus-derived lymphocytes exhibit a number of immunological functions. 114 references.

Case Report: CT diagnosis of thymic remnant cyst/thymopharyngeal duct cyst

International Nuclear Information System (INIS)

Daga, Bipin V; Chaudhary, VA; Dhamangaokar, VB

2009-01-01

A 4-year-old boy presented with history of left anterolateral neck swelling since birth. He was clinically diagnosed to have a branchial cleft cyst. A CT scan revealed findings suggestive of a thymic remnant cyst. The lesion was excised and the diagnosis was confirmed by histopathology

A Prospective Phase II Study of Cisplatin and Cremophor EL-Free Paclitaxel (Genexol-PM) in Patients with Unresectable Thymic Epithelial Tumors.

Science.gov (United States)

Kim, Hae Su; Lee, Ji Yun; Lim, Sung Hee; Sun, Jong-Mu; Lee, Se Hoon; Ahn, Jin Seok; Park, Keunchil; Moon, Seung Hwan; Ahn, Myung-Ju

2015-12-01

We conducted a prospective phase II study of cisplatin plus cremophor EL-free paclitaxel (Genexol-PM) in patients with unresectable thymic epithelial tumors to determine the efficacy and tolerability of the combination therapy. Patients were treated with cisplatin (70 mg/m) and Genexol-PM (230 mg/m) on day 1 of a 3-week cycle as first-line palliative chemotherapy. The primary end point of this study was objective response rate, and the secondary end points included toxicity, progression-free survival (PFS), overall survival, correlation between early 18F-fluorodeoxyglucose positron emission tomography/computed tomography response and PFS, and correlation between baseline flurododeoxyglucose uptake and histology. Forty-two patients with unresectable thymoma (n = 14) or thymic carcinoma (n = 28) were enrolled between May 2012 and October 2014. The median age was 59 years (range: 25-77) and 30 patients (71%) were male, and 39 patients (93%) had an ECOG PS of 1. The median number of treatment cycles was six (range: 1-6). For 40 assessable patients, the objective response rate was 62.5% (95% confidence interval [CI]: 47.6-77.4) with rates of 46% (95% CI: 23.3-76.9) for advanced thymoma (n = 13) and 70% (95% CI: 52.0-82.1) for thymic carcinoma (n = 27). With a median follow-up of 15.5 months, the median PFS for all 42 patients was 9.8 months (11.4 months for thymoma versus 8.1 months for thymic carcinoma). The 2-year overall survival was 77.9% for thymoma and 65.9% for thymic carcinoma. There were no treatment-related deaths. The most common grade 3 and 4 treatment-related adverse event was neutropenia in 11 patients (26%). Eight patients (19%) experienced grade 2 hypersensitivity reactions. There was no correlation between early positron emission tomography response and PFS, but tumor histology (thymoma versus thymic carcinoma) was correlated with SUVmax before chemotherapy. These data suggest that combination of cisplatin and Genexol-PM is highly effective and

Anti-Apoptotic Signature in Thymic Squamous Cell Carcinomas – Functional Relevance of Anti-Apoptotic BIRC3 Expression in the Thymic Carcinoma Cell Line 1889c

Science.gov (United States)

Huang, Bei; Belharazem, Djeda; Li, Li; Kneitz, Susanne; Schnabel, Philipp A.; Rieker, Ralf J.; Körner, Daniel; Nix, Wilfred; Schalke, Berthold; Müller-Hermelink, Hans Konrad; Ott, German; Rosenwald, Andreas; Ströbel, Philipp; Marx, Alexander

2013-01-01

The molecular pathogenesis of thymomas and thymic carcinomas (TCs) is poorly understood and results of adjuvant therapy are unsatisfactory in case of metastatic disease and tumor recurrence. For these clinical settings, novel therapeutic strategies are urgently needed. Recently, limited sequencing efforts revealed that a broad spectrum of genes that play key roles in various common cancers are rarely affected in thymomas and TCs, suggesting that other oncogenic principles might be important. This made us re-analyze historic expression data obtained in a spectrum of thymomas and thymic squamous cell carcinomas (TSCCs) with a custom-made cDNA microarray. By cluster analysis, different anti-apoptotic signatures were detected in type B3 thymoma and TSCC, including overexpression of BIRC3 in TSCCs. This was confirmed by qRT-PCR in the original and an independent validation set of tumors. In contrast to several other cancer cell lines, the BIRC3-positive TSCC cell line, 1889c showed spontaneous apoptosis after BIRC3 knock-down. Targeting apoptosis genes is worth testing as therapeutic principle in TSCC. PMID:24427739

The size of the thymus: an important immunological diagnostic tool?

DEFF Research Database (Denmark)

Jeppesen, Dorthe Lisbeth

2003-01-01

of the thymus relevant to its function and could measurement of the thymus be a useful immunological diagnostic tool in the investigation of thymic function in humans with a depressed immune system? Conclusion: Studies using the size of the thymus as an immunological diagnostic tool should be encouraged....

Obturator externus was larger, while obturator internus size was similar in ballet dancers compared to nondancing athletes.

Science.gov (United States)

Mayes, Susan; Ferris, April-Rose; Smith, Peter; Cook, Jill

2018-06-02

To compare the cross-sectional area (CSA) of hip external rotators, obturator externus (OE) and obturator internus (OI), in ballet dancers and nondancing athletes, and evaluate the relationship between obturator muscle size and hip pain. Case-control study. Elite ballet and sport. 33 male and female professional ballet dancers and 33 age and sex-matched athletes. CSA's of OE and OI measured on magnetic resonance imaging (MRI) of one hip. Hip pain was scored with the Copenhagen Hip and Groin Outcome Score (HAGOS): HAGOS pain score of 100 was defined as no pain and a score less than 100 was defined as pain. Participants weight and height. Estimated marginal mean CSA of OE was 14% larger in dancers than athletes (p = 0.01, ηp2 = 0.1); the size of OI was similar (p > 0.05). Men and women in both groups had similar sized OI and OE. There was no interaction between the estimated marginal mean CSA of either obturator and hip pain. It appears that ballet selectively increases muscle size of OE, but not OI. Obturator size was not related to mild hip pain, as OE and OI size was similar in dancers and athletes with and without pain. Copyright © 2018. Published by Elsevier Ltd.

HLA-B*39:06 Efficiently Mediates Type 1 Diabetes in a Mouse Model Incorporating Reduced Thymic Insulin Expression.

Science.gov (United States)

Schloss, Jennifer; Ali, Riyasat; Racine, Jeremy J; Chapman, Harold D; Serreze, David V; DiLorenzo, Teresa P

2018-04-09

Type 1 diabetes (T1D) is characterized by T cell-mediated destruction of the insulin-producing β cells of the pancreatic islets. Among the loci associated with T1D risk, those most predisposing are found in the MHC region. HLA-B*39:06 is the most predisposing class I MHC allele and is associated with an early age of onset. To establish an NOD mouse model for the study of HLA-B*39:06, we expressed it in the absence of murine class I MHC. HLA-B*39:06 was able to mediate the development of CD8 T cells, support lymphocytic infiltration of the islets, and confer T1D susceptibility. Because reduced thymic insulin expression is associated with impaired immunological tolerance to insulin and increased T1D risk in patients, we incorporated this in our model as well, finding that HLA-B*39:06-transgenic NOD mice with reduced thymic insulin expression have an earlier age of disease onset and a higher overall prevalence as compared with littermates with typical thymic insulin expression. This was despite virtually indistinguishable blood insulin levels, T cell subset percentages, and TCR Vβ family usage, confirming that reduced thymic insulin expression does not impact T cell development on a global scale. Rather, it will facilitate the thymic escape of insulin-reactive HLA-B*39:06-restricted T cells, which participate in β cell destruction. We also found that in mice expressing either HLA-B*39:06 or HLA-A*02:01 in the absence of murine class I MHC, HLA transgene identity alters TCR Vβ usage by CD8 T cells, demonstrating that some TCR Vβ families have a preference for particular class I MHC alleles. Copyright © 2018 by The American Association of Immunologists, Inc.

Artificial selection on relative brain size in the guppy reveals costs and benefits of evolving a larger brain.

Science.gov (United States)

Kotrschal, Alexander; Rogell, Björn; Bundsen, Andreas; Svensson, Beatrice; Zajitschek, Susanne; Brännström, Ioana; Immler, Simone; Maklakov, Alexei A; Kolm, Niclas

2013-01-21

The large variation in brain size that exists in the animal kingdom has been suggested to have evolved through the balance between selective advantages of greater cognitive ability and the prohibitively high energy demands of a larger brain (the "expensive-tissue hypothesis"). Despite over a century of research on the evolution of brain size, empirical support for the trade-off between cognitive ability and energetic costs is based exclusively on correlative evidence, and the theory remains controversial. Here we provide experimental evidence for costs and benefits of increased brain size. We used artificial selection for large and small brain size relative to body size in a live-bearing fish, the guppy (Poecilia reticulata), and found that relative brain size evolved rapidly in response to divergent selection in both sexes. Large-brained females outperformed small-brained females in a numerical learning assay designed to test cognitive ability. Moreover, large-brained lines, especially males, developed smaller guts, as predicted by the expensive-tissue hypothesis, and produced fewer offspring. We propose that the evolution of brain size is mediated by a functional trade-off between increased cognitive ability and reproductive performance and discuss the implications of these findings for vertebrate brain evolution. Copyright © 2013 Elsevier Ltd. All rights reserved.

An early thymic precursor phenotype predicts outcome exclusively in HOXA-overexpressing adult T-cell acute lymphoblastic leukemia: a Group for Research in Adult Acute Lymphoblastic Leukemia study.

Science.gov (United States)

Bond, Jonathan; Marchand, Tony; Touzart, Aurore; Cieslak, Agata; Trinquand, Amélie; Sutton, Laurent; Radford-Weiss, Isabelle; Lhermitte, Ludovic; Spicuglia, Salvatore; Dombret, Hervé; Macintyre, Elizabeth; Ifrah, Norbert; Hamel, Jean-François; Asnafi, Vahid

2016-06-01

Gene expression studies have consistently identified a HOXA-overexpressing cluster of T-cell acute lymphoblastic leukemias, but it is unclear whether these constitute a homogeneous clinical entity, and the biological consequences of HOXA overexpression have not been systematically examined. We characterized the biology and outcome of 55 HOXA-positive cases among 209 patients with adult T-cell acute lymphoblastic leukemia uniformly treated during the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL)-2003 and -2005 studies. HOXA-positive patients had markedly higher rates of an early thymic precursor-like immunophenotype (40.8% versus 14.5%, P=0.0004), chemoresistance (59.3% versus 40.8%, P=0.026) and positivity for minimal residual disease (48.5% versus 23.5%, P=0.01) than the HOXA-negative group. These differences were due to particularly high frequencies of chemoresistant early thymic precursor-like acute lymphoblastic leukemia in HOXA-positive cases harboring fusion oncoproteins that transactivate HOXA Strikingly, the presence of an early thymic precursor-like immunophenotype was associated with marked outcome differences within the HOXA-positive group (5-year overall survival 31.2% in HOXA-positive early thymic precursor versus 66.7% in HOXA-positive non-early thymic precursor, P=0.03), but not in HOXA-negative cases (5-year overall survival 74.2% in HOXA-negative early thymic precursor versus 57.2% in HOXA-negative non-early thymic precursor, P=0.44). Multivariate analysis further revealed that HOXA positivity independently affected event-free survival (P=0.053) and relapse risk (P=0.039) of chemoresistant T-cell acute lymphoblastic leukemia. These results show that the underlying mechanism of HOXA deregulation dictates the clinico-biological phenotype, and that the negative prognosis of early thymic precursor acute lymphoblastic leukemia is exclusive to HOXA-positive patients, suggesting that early treatment intensification is currently

Thymic stromal lymphopoietin as a novel mediator amplifying immunopathology in rheumatic disease

NARCIS (Netherlands)

Hillen, Maarten R.; Radstake, Timothy R. D. J.; Hack, Cornelis E.; van Roon, Joel A. G.

2015-01-01

Thymic stromal lymphopoietin (TSLP) is an IL-7-related cytokine that has been studied extensively in atopic diseases and more recently in various rheumatic disorders. It is involved in T cell development in the thymus and promotes homeostatic T cell expansion by classical dendritic cells. However,

Isolated thymic Langerhans cell histiocytosis discovered on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT).

Science.gov (United States)

Turpin, Sophie; Carret, Anne-Sophie; Dubois, Josée; Buteau, Chantal; Patey, Natalie

2015-11-01

The thymic infiltration in young patients with multisystemic Langerhans cell histiocytosis and its radiologic features are well known. However, isolated thymic disease has seldom been reported in the literature. We report the case of a 10-month-old child admitted for fever of unknown origin. Whole-body F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) was performed to identify a focus of infection. It demonstrated an unusual aspect of the thymus, which led to further investigation and revealed isolated infiltration of the thymus by Langerhans cell histiocytosis. The patient was treated accordingly and is now disease free. As evaluation of Langerhans cell histiocytosis patients with F-18 FDG PET/CT is becoming more frequent, it is important to be aware of the scintigraphical characteristics of thymic Langerhans cell histiocytosis.

Isolated thymic Langerhans cell histiocytosis discovered on F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT)

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Turpin, Sophie [CHU Sainte-Justine, Nuclear Medicine, Montreal (Canada); Carret, Anne-Sophie [CHU Sainte-Justine, Hemato-Oncology, Montreal (Canada); Dubois, Josee [CHU Sainte-Justine, Radiology, Montreal (Canada); Buteau, Chantal [CHU Sainte-Justine, Infectious Diseases, Montreal (Canada); Patey, Natalie [CHU Sainte-Justine, Pathology, Montreal (Canada)

2015-11-15

The thymic infiltration in young patients with multisystemic Langerhans cell histiocytosis and its radiologic features are well known. However, isolated thymic disease has seldom been reported in the literature. We report the case of a 10-month-old child admitted for fever of unknown origin. Whole-body F-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) was performed to identify a focus of infection. It demonstrated an unusual aspect of the thymus, which led to further investigation and revealed isolated infiltration of the thymus by Langerhans cell histiocytosis. The patient was treated accordingly and is now disease free. As evaluation of Langerhans cell histiocytosis patients with F-18 FDG PET/CT is becoming more frequent, it is important to be aware of the scintigraphical characteristics of thymic Langerhans cell histiocytosis. (orig.)

Early thymic T cell development in young transgenic mice overexpressing human Cu/Zn superoxide dismutase, a model of Down syndrome.

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Laurent, Julien; Paly, Evelyne; Marche, Patrice N; London, Jacqueline

2006-06-01

Previous studies have shown that transgenic mice overexpressing Cu/Zn superoxide dismutase, a model of Down syndrome, exhibit premature thymic involution. We have performed a flow cytometry analysis of the developing thymus in these homozygous transgenic mice (hSOD1/hSOD1: Tg-SOD). Longitudinal follow-up analysis from day 3 to day 280 showed an early thymic development in Tg-SOD mice compared with controls. This early thymic development was associated with an increased migration of mature T cells to peripheral lymphoid organs. BrdU labeling showed no difference between Tg-SOD and control mice, confirming that the greater number of peripheral T cells in Tg-SOD mice was not due to extensive proliferation of these cells but rather to a greater pool of emigrant T cells in Tg-SOD.

HTLV-1-infected thymic epithelial cells convey the virus to CD4+ T lymphocytes.

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Carvalho Barros, Luciana Rodrigues; Linhares-Lacerda, Leandra; Moreira-Ramos, Klaysa; Ribeiro-Alves, Marcelo; Machado Motta, Maria Cristina; Bou-Habib, Dumith Chequer; Savino, Wilson

2017-12-01

The human T-lymphotropic virus type-1 (HTLV-1) is the causative agent of adult T cell leukemia/lymphoma (ATL) and HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). CD4 + T cells are the main target of HTLV-1, but other cell types are known to be infected, including immature lymphocytes. Developing T cells undergo differentiation in the thymus, through migration and interaction with the thymic microenvironment, in particular with thymic epithelial cells (TEC) the major component of this three dimensional meshwork of non-lymphoid cells. Herein, we show that TEC express the receptors for HTLV-1 and can be infected by this virus through cell-cell contact and by cell-free virus suspensions. The expression of anti-apoptosis, chemokine and adhesion molecules genes are altered in HTLV-1-infected TEC, although gene expression of antigen presentation molecules remained unchanged. Furthermore, HTLV-1-infected TEC transmitted the virus to a CD4 + T cell line and to CD4 + T cells from healthy donors, during in vitro cellular co-cultures. Altogether, our data point to the possibility that the human thymic epithelial cells play a role in the establishment and progression of HTLV-1 infection, functioning as a reservoir and transmitting the virus to maturing CD4 + T lymphocytes, which in turn will cause disease in the periphery. Copyright © 2017. Published by Elsevier GmbH.

Exploring the link between innate immune activation and thymic function by measuring sCD14 and TRECs in HIV patients living in Belgium.

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Adrien De Voeght

Full Text Available Microbial translocation is now viewed as a central event in the pathogenesis of chronic inflammation during HIV infection. Thymic function failure is another crucial factor involved in HIV disease progression. The goal of this study was to explore the hypothesis of potential links between microbial translocation and thymic function in HIV-1 patients living in Belgium. The extent of microbial translocation was assessed through the measurement of soluble CD14 (sCD14. T-cell receptor excision circles (sjTRECs and dβTRECs were used as a measure of thymic function. Data were collected from 75 HIV-infected patients. Simple and complex linear regressions were done to analyze the link between these two processes. We found a statistically relevant negative correlation between thymopoiesis (sjTREC and sCD14 level (p = 0.004. These results suggest a link between thymic function failure, microbial translocation and innate immune activation.

Heat shock protein 90-sheltered overexpression of insulin-like growth factor 1 receptor contributes to malignancy of thymic epithelial tumors.

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Breinig, Marco; Mayer, Philipp; Harjung, Andreas; Goeppert, Benjamin; Malz, Mona; Penzel, Roland; Neumann, Olaf; Hartmann, Arndt; Dienemann, Hendrik; Giaccone, Giuseppe; Schirmacher, Peter; Kern, Michael André; Chiosis, Gabriela; Rieker, Ralf Joachim

2011-04-15

The underlying molecular mechanisms of thymic epithelial malignancies (TEMs) are poorly understood. Consequently, there is a lack of efficacious targeted therapies and patient prognosis remains dismal, particularly for advanced TEMs. We sought to investigate protumorigenic mechanism relevant to this understudied cancer. Recently established cell lines derived from thymic epithelial tumors were used as a model system. The antitumor activity of specific heat shock protein 90 (Hsp90) inhibitors was investigated by an analysis of cell viability, cell cycle, and apoptosis using MTT-assays and flow cytometry. Western blotting was used to investigate the altered expression of Hsp90 clients. Pharmacological inhibitors against select Hsp90 clients, as well as RNAi, were employed to test the relevance of each client independently. Tissue microarray analysis was performed to match the in vitro findings with observations obtained from patient-derived samples. Hsp90 inhibition significantly reduces cell viability of thymic carcinoma cells, induces cell cycle arrest and apoptosis, and blocks invasiveness. Hsp90 inhibition triggers the degradation of multiple oncogenic clients, for example insulin-like growth factor 1 receptor (IGF-1R), CDK4, and the inactivation of PI3K/Akt and RAF/Erk signaling. Mechanistically, the IGF/IGF-1R-signaling axis contributes to the establishment of the antiapoptotic phenotype of thymic cancer cells. Finally, IGF-1R is overexpressed in advanced TEMs. We have unraveled a novel protumorigenic mechanism in TEMs, namely Hsp90-capacitated overexpression of IGF-1R, which confers apoptosis evasion in malignant thymic epithelial cells. Our data indicate that Hsp90 inhibition, which simultaneously blocks multiple cancer hallmarks, represents a therapeutic strategy in TEMs that may merit evaluation in clinical trials. ©2011 AACR.

PRESENCE OF THYMIC TISSUE IN THE ANTERIOR MEDIASTINAL FATTY TISSUE AND ITS SIGNIFICANCE IN THYMECTOMY FOR MYASTHENIA GRAVIS PATIENT: A CASE REPORT

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Athouba

2016-03-01

Full Text Available In 1970s, presence of thymic tissue in anterior mediastinal adipose tissue around the thymus was found. Here we report a case of ectopic thymic tissue in the mediastinum and the possible relevance of this distribution of thymic tissue outside thymus to the therapeutic yield of thymectomies in myasthenia gravis. A 30-year lady with myasthenia gravis (nonthymomatous presented with difficulty in swallowing and breathing for the last 1 years. She was under medical treatment but with little improvement. She underwent extended thymectomy, after which an en bloc resection of the anterior mediastinal fat tissues from pericardium and pleura, including the thymus, was performed. Grossly the soft tissue specimen taken from near left lateral area of heart was fibrofatty tissue. Microscopically isolated thymic tissues were seen interspersed among the fatty tissues composed of mature lymphocytes, epithelial cells and few Hassall's corpuscles were observed. Thymus specimen was within normal histological limits. To ensure complete removal, the adipose tissue at the anterior mediastinum as well as the gross thymus should be removed. Thymic tissue incidence in individual locations was as follows: Retrothyroid, 3(6%; peritracheal, 5 (10%; retrotracheal, 1 (2%; right phrenic nerve, 2 (4%; left phrenic nerve, 14 (28%; right recurrent laryngeal nerve, 2 (4%; left recurrent laryngeal nerve, 2 (4% and periaortic, 0. Trans-sternal thymectomy was found to be beneficial to all patients of mild-to-moderate myasthenia gravis with 70.2% patients showing improvement postoperatively.

Immune recovery in acute and chronic HIV infection and the impact of thymic stromal lymphopoietin

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Gelpi, Marco; Hartling, Hans J; Thorsteinsson, Kristina

2016-01-01

was comparable in all groups, and no differences in immune homeostasis were found between primary HIV infection and early presenters, whereas differences in absolute counts and proportions of CD4+ T cell subpopulations were found between primary HIV infection and late presenters. TSLP was elevated in primary HIV...... thymic output, but not with immune recovery. These findings indicate a possible role of TSLP in immune homeostasis in HIV infection but do not support TSLP to affect immune recovery in primary HIV infection.......BACKGROUND: Symptomatic primary HIV infection is associated with an adverse prognosis, and immediate initiation of combination antiretroviral therapy (cART) is recommended. However, little is known about immunological predictors of immune recovery. Thymic Stromal Lymphopoietin (TSLP) is a cytokine...

Induction of epithelial to mesenchymal transition (EMT) and inhibition on adipogenesis: Two different sides of the same coin? Feasible roles and mechanisms of transforming growth factor β1 (TGF-β1) in age-related thymic involution.

Science.gov (United States)

Tan, Jianxin; Wang, Yajun; Zhang, Nannan; Zhu, Xike

2016-08-01

Age-related thymic involution is characterized by a loss of thymic epithelial cells (TECs) and a concomitant increase in adipocytes, but the mechanisms involved in thymic adipogenesis are still not clear. Transforming growth factor β1 (TGF-β1) is a pleiotropic cytokine that has been reported to be up-regulated with age in thymic stromal cells in both human and mouse. However, the exact role of TGF-β1 in age-related thymic involution remains to be further elucidated. On the basis of previous findings, we propose a novel hypothesis that TGF-β1 functions a dual role in age-related thymic involution. On one hand, up-regulation of TGF-β1 promotes epithelial to mesenchymal transition (EMT) process in TECs via activating forkhead box protein C2 (FoxC2). On the other hand, TGF-β1 inhibits the transdifferentiation of EMT-derived mesenchymal cells to adipocytes in the thymus. If confirmed, our hypothesis will not only provide further evidence supporting that the transdifferentiation of TECs into pre-adipocytes represents a source of thymic adiposity during age-related thymic involution, but also uncover a unique role of TGF-β1 in the transdifferentiation of TECs into pre-adipocytes. Collectively, the inhibition of TGF-β1 may serve as a strategy to hinder age-related thymic involution or even to restore thymic function in the elderly. © 2016 International Federation for Cell Biology.

Increased cFLIP expression in thymic epithelial tumors blocks autophagy via NF-κB signalling.

Science.gov (United States)

Belharazem, Djeda; Grass, Albert; Paul, Cornelia; Vitacolonna, Mario; Schalke, Berthold; Rieker, Ralf J; Körner, Daniel; Jungebluth, Philipp; Simon-Keller, Katja; Hohenberger, Peter; Roessner, Eric M; Wiebe, Karsten; Gräter, Thomas; Kyriss, Thomas; Ott, German; Geserick, Peter; Leverkus, Martin; Ströbel, Philipp; Marx, Alexander

2017-10-27

The anti-apoptotic cellular FLICE-like inhibitory protein cFLIP plays a pivotal role in normal tissues homoeostasis and the development of many tumors, but its role in normal thymus (NT), thymomas and thymic carcinomas (TC) is largely unknown. Expression, regulation and function of cFLIP were analyzed in biopsies of NT, thymomas, thymic squamous cell carcinomas (TSCC), thymic epithelial cells (TECs) derived thereof and in the TC line 1889c by qRT-PCR, western blot, shRNA techniques, and functional assays addressing survival, senescence and autophagy. More than 90% of thymomas and TSCCs showed increased cFLIP expression compared to NT. cFLIP expression declined with age in NTs but not in thymomas. During short term culture cFLIP expression levels declined significantly slower in neoplastic than non-neoplastic primary TECs. Down-regulation of cFLIP by shRNA or NF-κB inhibition accelerated senescence and induced autophagy and cell death in neoplastic TECs. The results suggest a role of cFLIP in the involution of normal thymus and the development of thymomas and TSCC. Since increased expression of cFLIP is a known tumor escape mechanism, it may serve as tissue-based biomarker in future clinical trials, including immune checkpoint inhibitor trials in the commonly PD-L1 high thymomas and TCs.

Development of donor-derived thymic lymphomas after allogeneic bone marrow transplantation in AKR/J mice

International Nuclear Information System (INIS)

Yasumizu, R.; Hiai, H.; Sugiura, K.

1988-01-01

The transplantation of bone marrow cells from BALB/c (but not C57BL/6 and C3H/HeN) mice was observed to lead to the development of thymic lymphomas (leukemias) in AKR/J mice. Two leukemic cell lines, CAK1.3 and CAK4.4, were established from the primary culture of two thymic lymphoma, and surface phenotypes of these cell lines found to be H-2d and Thy-1.2+, indicating that these lymphoma cells are derived from BALB/c donor bone marrow cells. Further analyses of surface markers revealed that CAK1.3 is L3T4+ Lyt2+ IL2R-, whereas CAK4.4 is L3T4- Lyt2- IL2R+. Both CAK1.3 and CAK4.4 were transplantable into BALB/c but not AKR/J mice, further indicating that these cells are of BALB/c bone marrow donor origin. The cells were found to produce XC+-ecotropic viruses, but xenotropic and mink cell focus-forming viruses were undetectable. Inasmuch as thymic lymphomas are derived from bone marrow cells of leukemia-resistant BALB/c strain of mice under the allogeneic environment of leukemia-prone AKR/J mice, this animal model may serve as a useful tool not only for the analysis of leukemic relapse after bone marrow transplantation but also for elucidation of the mechanism of leukemogenesis

How nonuniform contact profiles of T cell receptors modulate thymic selection outcomes

Science.gov (United States)

Chen, Hanrong; Chakraborty, Arup K.; Kardar, Mehran

2018-03-01

T cell receptors (TCRs) bind foreign or self-peptides attached to major histocompatibility complex (MHC) molecules, and the strength of this interaction determines T cell activation. Optimizing the ability of T cells to recognize a diversity of foreign peptides yet be tolerant of self-peptides is crucial for the adaptive immune system to properly function. This is achieved by selection of T cells in the thymus, where immature T cells expressing unique, stochastically generated TCRs interact with a large number of self-peptide-MHC; if a TCR does not bind strongly enough to any self-peptide-MHC, or too strongly with at least one self-peptide-MHC, the T cell dies. Past theoretical work cast thymic selection as an extreme value problem and characterized the statistical enrichment or depletion of amino acids in the postselection TCR repertoire, showing how T cells are selected to be able to specifically recognize peptides derived from diverse pathogens yet have limited self-reactivity. Here, we investigate how the diversity of the postselection TCR repertoire is modified when TCRs make nonuniform contacts with peptide-MHC. Specifically, we were motivated by recent experiments showing that amino acids at certain positions of a TCR sequence have large effects on thymic selection outcomes, and crystal structure data that reveal a nonuniform contact profile between a TCR and its peptide-MHC ligand. Using a representative TCR contact profile as an illustration, we show via simulations that the statistical enrichment or depletion of amino acids now varies by position according to the contact profile, and, importantly, it depends on the implementation of nonuniform contacts during thymic selection. We explain these nontrivial results analytically. Our study has implications for understanding the selection forces that shape the functionality of the postselection TCR repertoire.

Association between thymic function and allogeneic hematopoietic stem cell transplantation outcome: results of a pediatric study.

Science.gov (United States)

Saglio, Francesco; Cena, Silvia; Berger, Massimo; Quarello, Paola; Boccasavia, Viola; Ferrando, Federica; Pittana, Laura; Bruno, Benedetto; Fagioli, Franca

2015-06-01

Robust T cell function recovery has been shown to be crucial in determining allogeneic hematopoietic stem cell transplantation (HSCT) outcome, and there is growing evidence that the thymus plays a central role in regulating this process. We performed a long-term analysis of the role of thymic activity recovery in a population of pediatric patients undergoing allogeneic HSCT by signal joint T cell receptor excision circle (sjTREC) quantification. In this study, characterized by a long-term follow-up (median, 72 months), we found patients with higher levels of sjTRECs before transplantation had a statistically significant reduced risk of death compared with patients with lower values (relative risk, .31; 95% confidence interval, .30 to .32; P = .02), showing this different outcome was mainly related to a reduction of relapse incidence (14% versus 43%, P = .02). Unlike previous reports, we observed no correlation between sjTREC levels and lymphocyte recovery. Moreover, we confirmed that only graft-versus-host disease influenced thymic activity after transplantation. In conclusion, our results suggest an association between pretransplantation thymic activity and the long-term outcome of pediatric patients undergoing HSCT, mainly through a reduction of relapse opportunities. Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Three distinct subsets of thymic epithelial cells in rats and mice defined by novel antibodies.

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Yasushi Sawanobori

Full Text Available Thymic epithelial cells (TECs are thought to play an essential role in T cell development and have been detected mainly in mice using lectin binding and antibodies to keratins. Our aim in the present study was to create a precise map of rat TECs using antibodies to putative markers and novel monoclonal antibodies (i.e., ED 18/19/21 and anti-CD205 antibodies and compare it with a map from mouse counterparts and that of rat thymic dendritic cells.Rat TECs were subdivided on the basis of phenotype into three subsets; ED18+ED19+/-keratin 5 (K5+K8+CD205+ class II MHC (MHCII+ cortical TECs (cTECs, ED18+ED21-K5-K8+Ulex europaeus lectin 1 (UEA-1+CD205- medullary TECs (mTEC1s, and ED18+ED21+K5+K8dullUEA-1-CD205- medullary TECs (mTEC2s. Thymic nurse cells were defined in cytosmears as an ED18+ED19+/-K5+K8+ subset of cTECs. mTEC1s preferentially expressed MHCII, claudin-3, claudin-4, and autoimmune regulator (AIRE. Use of ED18 and ED21 antibodies revealed three subsets of TECs in mice as well. We also detected two distinct TEC-free areas in the subcapsular cortex and in the medulla. Rat dendritic cells in the cortex were MHCII+CD103+ but negative for TEC markers, including CD205. Those in the medulla were MHCII+CD103+ and CD205+ cells were found only in the TEC-free area.Both rats and mice have three TEC subsets with similar phenotypes that can be identified using known markers and new monoclonal antibodies. These findings will facilitate further analysis of TEC subsets and DCs and help to define their roles in thymic selection and in pathological states such as autoimmune disorders.

Unusual Thymic Hyperplasia Mimicking Lipomatous Tumor in an Eight-Year-Old Boy with Concomitant Pericardial Lipomatosis and Right Facial Hemihypertrophy

International Nuclear Information System (INIS)

Kim, Yoo Jin; Kim Woo Sun; Cheon, Jung Eun; Lim, Yun Jung; Kim, In One; Yeon, Kyung Mo; Jung, Kyeong Cheon; Byun, Sun Ju

2011-01-01

We report a case of thymic hyperplasia accompanied by pericardial lipomatosis and right facial hemihypertrophy in an 8-year-old boy. On imaging studies, the hyperplastic thymus had prominent curvilinear and nodular fatty areas simulating a fat-containing anterior mediastinal mass, which is an unusual finding in children. To our knowledge, this is the first report on a child with a combination of thymic hyperplasia, pericardial lipomatosis, and right facial hemihypertrophy. The radiologic findings are presented with a brief discussion.

Increased cell division but not thymic dysfunction rapidly affects the T-cell receptor excision circle content of the naive T cell population in HIV-1 infection

NARCIS (Netherlands)

Hazenberg, Mette D.; Borleffs, J.C.C.; Otto, S.A.; Cohen Stuart, J.W.T. (James Willem Theodoor); Verschuren, M.C.M. (Martie); Boucher, C.A.B.; Coutinho, R.A.; Lange, Joep M.A.; Rinke de Wit, T.F. (Tobias); Tsegaye, A. (Aster); Dongen, J.J.M. (Jaques) van; Hamann, D. (Dörte); Boer, R.J. de; Miedema, F.

2000-01-01

Recent thymic emigrants can be identified by T cell receptor excision circles (TRECs) formed during T-cell receptor rearrangement. Decreasing numbers of TRECs have been observed with aging and in human immunodeficiency virus (HIV)-1 infected individuals, suggesting for thymic impairment. Here,

Human thymic epithelial cells express functional HLA-DP molecules

DEFF Research Database (Denmark)

Jørgensen, A; Röpke, C; Nielsen, M

1996-01-01

T lymphocytes, we examined whether human thymic epithelial cells (TEC) expressed HLA-DP molecules. We present evidence that TEC obtained from short time culture express low but significant levels of HLA-DP molecules. The expression of HLA-DP molecules was comparable to or higher than the expression...... of HLA-DP allospecific primed lymphocyte typing (PLT) CD4 T cell lines. IFN-gamma treatment strongly upregulated the HLA-DP allospecific PLT responses whereas other PLT responses remained largely unchanged. In conclusion, these data indicate that human thymus epithelial cells express significant levels...

Immunologic competence in adults following thymic irradiation in infancy

International Nuclear Information System (INIS)

Ammann, A.J.; Wara, W.M.; Wara, D.W.; Phillips, T.L.

1977-01-01

Removal of, or irradiation to, the thymus during the neonatal period in man has resulted in no reported adverse effects on cellular immunity, although thymectomy in neonatal experimental animals is known to produce profound immunological disturbances. Adverse effects in humans may not be recognized until several decades have passed. The immunological capabilities of 7 adults with histories of thymic irradiation as infants were evaluated; normal tests results indicated intact immune systems in all cases. The 3 women tested, however, had abnormal clinical histories, including 2 with multiple tumors and 1 with chronic mucocutaneous candidiasis

Immunologic competence in adults following thymic irradiation in infancy

Energy Technology Data Exchange (ETDEWEB)

Ammann, A.J.; Wara, W.M.; Wara, D.W.; Phillips, T.L.

1977-07-01

Removal of, or irradiation to, the thymus during the neonatal period in man has resulted in no reported adverse effects on cellular immunity, although thymectomy in neonatal experimental animals is known to produce profound immunological disturbances. Adverse effects in humans may not be recognized until several decades have passed. The immunological capabilities of 7 adults with histories of thymic irradiation as infants were evaluated; normal tests results indicated intact immune systems in all cases. The 3 women tested, however, had abnormal clinical histories, including 2 with multiple tumors and 1 with chronic mucocutaneous candidiasis.

Genetic analysis of radiation-induced mouse thymic lymphomas

International Nuclear Information System (INIS)

Kominami, R.; Wakabayashi, Y.; Niwa, O.

2003-01-01

Mouse thymic lymphomas are one of the classic models of radiation-induced malignancies, and the model has been used for the study of genes involved in carcinogenesis. ras oncogenes are the first isolate which undergoes mutations in 10 to 30 % of lymphomas, and p16INK4a and p19ARF in the INK4a-ARF locus are also frequently inactivated. In our previous study, the inactivation of Ikaros, a key regurator of lymphoid system, was found in those lymphomas, and it was suggested that there are other responsible genes yet to be discovered. On the other hand, genetic predisposition to radiation-induced lymphoma often differs in different strains, and this reflects the presence of low penetrance genes that can modify the impact of a given mutation. Little study of such modifiers or susceptibility genes has been performed, either. Recent availability of databases on mouse genome information and the power of mouse genetic system underline usefulness of the lymphoma model in search for novel genes involved, which may provide clues to molecular mechanisms of development of the radiogenic lymphoma and also genes involved in human lymphomas and other malignancies. Accordingly, we have carried out positional cloning for the two different types of tumor-related genes. In this symposium, our current progress is presented that includes genetic mapping of susceptibility/ resistance loci on mouse chromosomes 4, 5 and 19, and also functional analysis of a novel tumor suppressor gene, Rit1/Bcl11b, that has been isolated from allelic loss (LOH) mapping and sequence analysis for γ -ray induced mouse thymic lymphomas

Changes in protein expression in p53 deleted spontaneous thymic lymphomas

DEFF Research Database (Denmark)

Honoré, Bent; Vorum, Henrik; Pedersen, Anders Elm

2004-01-01

with the protein expression in p53+/+ and p53-/- thymocytes. Only a minority (13 proteins) of the quantitatively changed proteins were common for the two thymic lymphoma cell lines, suggesting that the p53 deficiency mainly results in genetic dysfunctions which are individual for a given tumor. Two of the detected...... structure containing motifs of the glyoxalase-bleomycin resistance protein family (MDR) as deduced from the cDNA....

Complicated biallelic inactivation of Pten in radiation-induced mouse thymic lymphomas

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Yamaguchi, Yu [Department of Biology, Graduate School of Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Takabatake, Takashi; Kakinuma, Shizuko; Amasaki, Yoshiko; Nishimura, Mayumi; Imaoka, Tatsuhiko; Yamauchi, Kazumi; Shang, Yi [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Miyoshi-Imamura, Tomoko [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan); Genetic Counseling Program, Graduate School of Humanities and Sciences, Ochanomizu University, 2-1-1 Otsuka, Bunkyou-ku, Tokyo 112-8610 (Japan); Nogawa, Hiroyuki [Department of Biology, Graduate School of Science, Chiba University, Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Kobayashi, Yoshiro [Department of Biomolecular Science, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba 274-8510 (Japan); Shimada, Yoshiya, E-mail: y_shimad@nirsgo.jp [Experimental Radiobiology for Children' s Health Research Group, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba 263-8555 (Japan)

2010-04-01

Inactivation of the phosphatase and tensin homolog gene (Pten) occurs via multiple tissue-dependent mechanisms including epigenetic silencing, point mutations, insertions, and deletions. Although frequent loss of heterozygosity around the Pten locus and plausible involvement of epigenetic silencing have been reported in radiation-induced thymic lymphomas, the proportion of lymphomas with inactivated Pten and the spectrum of causal aberrations have not been extensively characterized. Here, we assessed the mode of Pten inactivation by comprehensive analysis of the expression and alteration of Pten in 23 radiation-induced thymic lymphomas developed in B6C3F1 mice. We found no evidence for methylation-associated silencing of Pten; rather, complex structural abnormalities comprised of missense and nonsense mutations, 1- and 3-bp insertions, and focal deletions were identified in 8 of 23 lymphomas (35%). Sequencing of deletion breakpoints suggested that aberrant V(D)J recombination and microhomology-mediated rearrangement were responsible for the focal deletions. Seven of the 8 lymphomas had biallelic alterations, and 4 of them did not express Pten protein. These Pten aberrations coincided with downstream Akt phosphorylation. In conclusion, we demonstrate that Pten inactivation is frequently biallelic and is caused by a variety of structural abnormalities (rather than by epigenetic silencing) and is involved in radiation-induced lymphomagenesis.

Postoperative Radiation Therapy for Non-Small Cell Lung Cancer and Thymic Malignancies

International Nuclear Information System (INIS)

Gomez, Daniel R.; Komaki, Ritsuko

2012-01-01

For many thoracic malignancies, surgery, when feasible, is the preferred upfront modality for local control. However, adjuvant radiation plays an important role in minimizing the risk of locoregional recurrence. Tumors in the thoracic category include certain subgroups of non-small cell lung cancer (NSCLC) as well as thymic malignancies. The indications, radiation doses, and treatment fields vary amongst subtypes of thoracic tumors, as does the level of data supporting the use of radiation. For example, in the setting of NSCLC, postoperative radiation is typically reserved for close/positive margins or N2/N3 disease, although such diseases as superior sulcus tumors present unique cases in which the role of neoadjuvant vs. adjuvant treatment is still being elucidated. In contrast, for thymic malignancies, postoperative radiation therapy is often used for initially resected Masaoka stage III or higher disease, with its use for stage II disease remaining controversial. This review provides an overview of postoperative radiation therapy for thoracic tumors, with a separate focus on superior sulcus tumors and thymoma, including a discussion of acceptable radiation approaches and an assessment of the current controversies involved in its use

Inferior Vena Cava and Renal Vein Thrombosis Associated with Thymic Carcinoma

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Vlad Teodor Berbecar

2017-01-01

Full Text Available Thymic tumors are rare mediastinal tumors that can present with a wide variety of symptoms. They can cause distant manifestations and are frequently associated with paraneoplastic syndromes. In our case, we describe the evolution of a 68-year-old male whose first manifestation was thrombosis of the inferior vena cava and renal veins. Thrombosis of large abdominal veins is rare, especially without being associated with any other comorbidity or risk factors.

Long-term persistence of functional thymic epithelial progenitor cells in vivo under conditions of low FOXN1 expression

DEFF Research Database (Denmark)

Jin, Xin; Nowell, Craig S; Ulyanchenko, Svetlana

2014-01-01

does not require FOXN1. Here, we have used a revertible severely hypomorphic allele of Foxn1, Foxn1R, to test the stability of the common TEPC in vivo. By reactivating Foxn1 expression postnatally in Foxn1R/- mice we demonstrate that functional TEPCs can persist in the thymic rudiment until at least 6...... months of age, and retain the potential to give rise to both cortical and medullary thymic epithelial cells (cTECs and mTECs). These data demonstrate that the TEPC-state is remarkably stable in vivo under conditions of low Foxn1 expression, suggesting that manipulation of FOXN1 activity may prove...... a valuable method for long term maintenance of TEPC in vitro....

Molecular characterization of non-thymic lymphomas in mice exposed to continuous low-dose-rate g-ray irradiation

International Nuclear Information System (INIS)

Takabatake, T.; Fujikawa, K.; Nakamura, S.; Tanaka, S.; Tanaka, I.; Tanaka-Braga III, I.; Sunaga, Y.; Ichinoche, K.; Sato, F.; Tanaka, K.; Matsumoto, T.

2004-01-01

To investigate the effects of continuous low-dose-rate irradiation on life span and neoplasm incidence, SPE B6C3 F1 mice were irradiated with 137Cs-ray at dose-rates of 20, 1 and 0.05 mGy/day with accumulated doses equivalent to 8000, 40 and 20 mGy, respectively. Examination of a total of 3,000 irradiated and 1,000 non-irradiated control mice showed that the life spans of the both sexes irradiated at 20 mGy/day, respectively. Examination of a total of 3,000 irradiated and 1,000 non-irradiated control mice showed that the life spans of the both sexes irradiated at 20 mGy/day were significantly shorter than that of the non-irradiated group. No significant difference in the cause of death and mortality rates was found between the groups. However, non-thymic lymphomas, the most common lethal neoplasm, showed a tendency to develop at an earlier age in mice irradiated with 20 mGy/day, regardless of sex. to obtain clues on the molecular mechanisms underlying the earlier development of non-thymic lymphomas in 20 mGy/day irradiated group, detailed molecular characterizations of non-thymic lymphomas with respect to B-cell or T-cell origin was done by detecting rearrangements in immunoglobulin heavy gene and in T-cell receptor b-and g chain genes by Southem hybridization method. to determine whether the early development of non-thymic lymphomas in 20 mGy/day irradiated group is associated wi the any recurrent chromosomal imbalance such as deletions and amplifications, the genome-wide scanning is also currently in progress by both LOH and array CGH methods. Present data obtained by LOH method show that deletions in parts of chromosomes 11 and 12 were more frequent than in chromosomes 2, 4 and 14 in both the non-irradiated control and 20 mGy/day irradiated groups. this work is supported by grants from Aomori Prefecture, Japan. (Author)

Identification of differentially expressed proteins in spontaneous thymic lymphomas from knockout mice with deletion of p53

DEFF Research Database (Denmark)

Honoré, Bent; Buus, Søren; Claësson, Mogens H

2008-01-01

ABSTRACT: BACKGROUND: Knockout mice with a deletion of p53 spontaneously develop thymic lymphomas. Two cell lines (SM5 and SM7), established from two independent tumours, exhibited about fifty to seventy two-fold differentially expressed proteins compared to wild type thymocytes by two-dimensiona......ABSTRACT: BACKGROUND: Knockout mice with a deletion of p53 spontaneously develop thymic lymphomas. Two cell lines (SM5 and SM7), established from two independent tumours, exhibited about fifty to seventy two-fold differentially expressed proteins compared to wild type thymocytes by two...... alpha type 3, transforming acidic coiled-coil containing protein 3, mitochondrial ornithine aminotransferase and epidermal fatty acid binding protein and down-regulation of adenylosuccinate synthetase, tubulin beta-3 chain, a 25 kDa actin fragment, proteasome subunit beta type 9, cofilin-1 and glia...

Low thymic output in the 22q11.2 deletion syndrome measured by CCR9+CD45RA+ T cell counts and T cell receptor rearrangement excision circles

DEFF Research Database (Denmark)

Lima, K; Abrahamsen, Gitte Meldgaard; Foelling, I

2010-01-01

Thymic hypoplasia is a frequent feature of the 22q11.2 deletion syndrome, but we know little about patients' age-related thymic output and long-term consequences for their immune system. We measured the expression of T cell receptor rearrangement excision circles (TREC) and used flow cytometry...

Cell-intrinsic role for NF-kappa B-inducing kinase in peripheral maintenance but not thymic development of Foxp3+ regulatory T cells in mice.

Directory of Open Access Journals (Sweden)

Susan E Murray

Full Text Available NF-κB inducing kinase (NIK, MAP3K14 is a key signaling molecule in non-canonical NF-κB activation, and NIK deficient mice have been instrumental in deciphering the immunologic role of this pathway. Global ablation of NIK prevents lymph node development, impairs thymic stromal development, and drastically reduces B cells. Despite altered thymic selection, T cell numbers are near normal in NIK deficient mice. The exception is CD4(+ regulatory T cells (Tregs, which are reduced in the thymus and periphery. Defects in thymic stroma are known to contribute to impaired Treg generation, but whether NIK also plays a cell intrinsic role in Tregs is unknown. Here, we compared intact mice with single and mixed BM chimeric mice to assess the intrinsic role of NIK in Treg generation and maintenance. We found that while NIK expression in stromal cells suffices for normal thymic Treg development, NIK is required cell-intrinsically to maintain peripheral Tregs. In addition, we unexpectedly discovered a cell-intrinsic role for NIK in memory phenotype conventional T cells that is masked in intact mice, but revealed in BM chimeras. These results demonstrate a novel role for NIK in peripheral regulatory and memory phenotype T cell homeostasis.

S1P Lyase Regulation of Thymic Egress and Oncogenic Inflammatory Signaling

Science.gov (United States)

Kumar, Ashok; Zamora-Pineda, Jesus; Degagné, Emilie

2017-01-01

Sphingosine-1-phosphate (S1P) is a potent lipid signaling molecule that regulates pleiotropic biological functions including cell migration, survival, angiogenesis, immune cell trafficking, inflammation, and carcinogenesis. It acts as a ligand for a family of cell surface receptors. S1P concentrations are high in blood and lymph but low in tissues, especially the thymus and lymphoid organs. S1P chemotactic gradients are essential for lymphocyte egress and other aspects of physiological cell trafficking. S1P is irreversibly degraded by S1P lyase (SPL). SPL regulates lymphocyte trafficking, inflammation and other physiological and pathological processes. For example, SPL located in thymic dendritic cells acts as a metabolic gatekeeper that controls the normal egress of mature T lymphocytes from the thymus into the circulation, whereas SPL deficiency in gut epithelial cells promotes colitis and colitis-associated carcinogenesis (CAC). Recently, we identified a complex syndrome comprised of nephrosis, adrenal insufficiency, and immunological defects caused by inherited mutations in human SGPL1, the gene encoding SPL. In the present article, we review current evidence supporting the role of SPL in thymic egress, inflammation, and cancer. Lastly, we summarize recent progress in understanding other SPL functions, its role in inherited disease, and SPL targeting for therapeutic purposes. PMID:29333002

S1P Lyase Regulation of Thymic Egress and Oncogenic Inflammatory Signaling

Directory of Open Access Journals (Sweden)

Ashok Kumar

2017-01-01

Full Text Available Sphingosine-1-phosphate (S1P is a potent lipid signaling molecule that regulates pleiotropic biological functions including cell migration, survival, angiogenesis, immune cell trafficking, inflammation, and carcinogenesis. It acts as a ligand for a family of cell surface receptors. S1P concentrations are high in blood and lymph but low in tissues, especially the thymus and lymphoid organs. S1P chemotactic gradients are essential for lymphocyte egress and other aspects of physiological cell trafficking. S1P is irreversibly degraded by S1P lyase (SPL. SPL regulates lymphocyte trafficking, inflammation and other physiological and pathological processes. For example, SPL located in thymic dendritic cells acts as a metabolic gatekeeper that controls the normal egress of mature T lymphocytes from the thymus into the circulation, whereas SPL deficiency in gut epithelial cells promotes colitis and colitis-associated carcinogenesis (CAC. Recently, we identified a complex syndrome comprised of nephrosis, adrenal insufficiency, and immunological defects caused by inherited mutations in human SGPL1, the gene encoding SPL. In the present article, we review current evidence supporting the role of SPL in thymic egress, inflammation, and cancer. Lastly, we summarize recent progress in understanding other SPL functions, its role in inherited disease, and SPL targeting for therapeutic purposes.

Hematological alterations and thymic function in newborns of HIV-infected mothers receiving antiretroviral drugs.

Science.gov (United States)

Wongnoi, Rotjanee; Penvieng, Nawaporn; Singboottra, Panthong; Kingkeow, Doungnapa; Oberdorfer, Peninnah; Sirivatanapa, Pannee; Pornprasert, Sakorn

2013-06-08

To investigate the effects of antiretroviral (ARV) drugs on hematological parameters and thymic function in HIV-uninfected newborns of HIV-infected mothers. Cross sectional study. Chiang-Mai University Hospital, Chiang-Mai, Thailand. 49 HIV-uninfected and 26 HIV-infected pregnancies. Cord blood samples of newborns from HIV-uninfected and HIV-infected mothers were collected. Hematological parameters were measured using automatic blood cell count. T-cell receptor excision circles (TRECs) levels in cord blood mononuclear cells (CBMCs), CD4+ and CD8+ T-cells were quantified using real-time PCR.. Hemotological parameters and thymic function. Newborn of HIV-infected mother tended to have lower mean levels of hemoglobin than those of HIV-uninfected mother (137 ±22 vs 146 ±17 g/L, P = 0.05). Furthermore, mean of red blood cell (RBC) counts and hematocrit and median of TRECs in CD4+ T-cells in the newborns of the former were significantly lower than those of the latter [3.6 ±0.7 vs 4.8 ±0.6 x 1012 cells/L, P cells) in HIV-uninfected newborns of HIV-infected mothers.

Cellular and biochemical actions of adrenal glucocorticoid hormones on rat thymic lymphocytes.

OpenAIRE

Young, D A; Voris, B P; Nicholson, M L

1981-01-01

The molecular, biochemical, and cellular effects of adrenal glucocorticoid hormones on thymic lymphocytes are reviewed, with emphasis on their relationship to the growth suppressive and lethal actions that occur in lymphoid tissues when glucocorticoids are administered to the whole animal. The data support the hypothesis that the hormonal inhibition of growth and development is a consequence of its ability to suppress cellular energy production, causing the cells to behave as though they were...

Cyclosporine promotes the induction of thymic lymphomas in C57BL/6 mice initiated by a single dose of γ-radiation

International Nuclear Information System (INIS)

Yabu, Koji; Warty, V.S.; Gorelik, E.; Shinozuka, Hisashi

1991-01-01

We previously demonstrated that a single dose of γ-radiation (350 rads) was able to induce thymic lymphomas in C57BL mice when followed by promoting treatment with oral cyclosporine (CsA), a non-genotoxic immunosuppressant. We have now tested the efficacy of various doses of γ-radiation as an initiator of CsA promotion of the induction of thymic lymphomas in male C57BL mice. The effects of oral CsA on the splenic natural killer (NK) cell activity of non-irradiated and irradiated (400 rads, 1X) mice were tested by the standard 51 Cr release assays against YAC-1 cells. The cumulative incidence of thymic lymphomas induced by a single dose of γ-radiation at 100, 200, 400 and 600 rads were 10, 25, 63 and 75% respectively, after 42 weeks of CsA promotion. The splenic NK cell activity in non-irradiated mice given CsA for 4 weeks was twice as high as that in the control mice. CsA inhibited poly I:C-induced augmentation of the splenic NK cell activity. In mice given a single dose (400 rads) of γ-radiation and CsA for 4 weeks, a similar but reduced enhancement of the splenic NK cell activity as seen in non-irradiated mice was observed. These results indicate that the efficacy of CsA promotion in the induction of thymic lymphomas is dependent on the initiating doses of γ-radiation, and that CsA enhances host splenic NK cell activity during the early stage of tumor promotion. (author)

Osseous oligometastases from thymic carcinoma: a case report suggesting the effectiveness of palliative-intent radiotherapy treatment.

Science.gov (United States)

Kashima, Jumpei; Horio, Hirotoshi; Okuma, Yusuke; Hosomi, Yukio; Hishima, Tsunekazu

2016-01-01

Oligometastasis, a recently proposed concept, is defined as an intermediate state of cancer, between localized and systemic disease, that may be well controlled by local ablative treatment. Thymic carcinoma is a rare cancer with a poor prognosis. A definitive management approach has yet to be confirmed by a high level of evidence. We present the case of a 41-year-old female who underwent curative-intent surgery for a stage III squamous cell carcinoma of the thymus. Bone metastases were detected 1 year later by magnetic resonance imaging. These were treated with palliative-intent radiotherapy. Disease progression has not been observed in more than 15 years since the achievement of complete radiological remission. The treatment outcomes in this and other reported cases suggest that some patients with oligometastatic thymic carcinoma may achieve prolonged survival or even cure with low-dose radiotherapy delivered to the metastases.

Ontogeny of thymic independent antibody responses in vitro in normal mice and mice with an x-linked B cell defect

Energy Technology Data Exchange (ETDEWEB)

Mosier, D.E.; Mond, J.J.; Goldings, E.A.

1977-12-01

The primary in vitro antibody response of neonatal spleen cells to three thymic independent antigens has been examined. The time of onset of responsiveness to TNP-Brucella abortus and TNP-lipopolysaccharide was significantly earlier than the onset of responsiveness to TNP-Ficoll. This ontologic sequence was not affected by T cell depletion or antigen presentation on adult macrophages. In neonatal mice bearing the X-linked CBA/N defect, the response to TNP-Brucella abortus and TNP-lipopolysaccharide was much delayed and no response to TNP-Ficoll developed. We conclude that different thymic independent antigens address different subpopulations of B cells, one of which appears earlier in ontogeny than the other.

Ontogeny of thymic independent antibody responses in vitro in normal mice and mice with an x-linked B cell defect

International Nuclear Information System (INIS)

Mosier, D.E.; Mond, J.J.; Goldings, E.A.

1977-01-01

The primary in vitro antibody response of neonatal spleen cells to three thymic independent antigens has been examined. The time of onset of responsiveness to TNP-Brucella abortus and TNP-lipopolysaccharide was significantly earlier than the onset of responsiveness to TNP-Ficoll. This ontologic sequence was not affected by T cell depletion or antigen presentation on adult macrophages. In neonatal mice bearing the X-linked CBA/N defect, the response to TNP-Brucella abortus and TNP-lipopolysaccharide was much delayed and no response to TNP-Ficoll developed. We conclude that different thymic independent antigens address different subpopulations of B cells, one of which appears earlier in ontogeny than the other

Major features of immunesenescence, including reduced thymic output, are ameliorated by high levels of physical activity in adulthood.

Science.gov (United States)

Duggal, Niharika Arora; Pollock, Ross D; Lazarus, Norman R; Harridge, Stephen; Lord, Janet M

2018-04-01

It is widely accepted that aging is accompanied by remodelling of the immune system including thymic atrophy and increased frequency of senescent T cells, leading to immune compromise. However, physical activity, which influences immunity but declines dramatically with age, is not considered in this literature. We assessed immune profiles in 125 adults (55-79 years) who had maintained a high level of physical activity (cycling) for much of their adult lives, 75 age-matched older adults and 55 young adults not involved in regular exercise. The frequency of naïve T cells and recent thymic emigrants (RTE) were both higher in cyclists compared with inactive elders, and RTE frequency in cyclists was no different to young adults. Compared with their less active counterparts, the cyclists had significantly higher serum levels of the thymoprotective cytokine IL-7 and lower IL-6, which promotes thymic atrophy. Cyclists also showed additional evidence of reduced immunesenescence, namely lower Th17 polarization and higher B regulatory cell frequency than inactive elders. Physical activity did not protect against all aspects of immunesenescence: CD28 -ve CD57 +ve senescent CD8 T-cell frequency did not differ between cyclists and inactive elders. We conclude that many features of immunesenescence may be driven by reduced physical activity with age. © 2018 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Apoptosis-promoted tumorigenesis: γ-irradiation-induced thymic lymphomagenesis requires Puma-driven leukocyte death

OpenAIRE

Michalak, Ewa M.; Vandenberg, Cassandra J.; Delbridge, Alex R.D.; Wu, Li; Scott, Clare L.; Adams, Jerry M.; Strasser, Andreas

2010-01-01

Although tumor development requires impaired apoptosis, we describe a novel paradigm of apoptosis-dependent tumorigenesis. Because DNA damage triggers apoptosis through p53-mediated induction of BH3-only proteins Puma and Noxa, we explored their roles in γ-radiation-induced thymic lymphomagenesis. Surprisingly, whereas Noxa loss accelerated it, Puma loss ablated tumorigenesis. Tumor suppression by Puma deficiency reflected its protection of leukocytes from γ-irradiation-induced death, because...

The pack size effect: Influence on consumer perceptions of portion sizes

NARCIS (Netherlands)

Hieke, Sophie; Palascha, Aikaterini; Jola, Corinne; Wills, Josephine; Raats, Monique M.

2016-01-01

Larger portions as well as larger packs can lead to larger prospective consumption estimates, larger servings and increased consumption, described as 'portion-size effects' and 'pack size effects'. Although related, the effects of pack sizes on portion estimates have received less attention. While

Hybrid Josephson-CMOS Memory in Advanced Technologies and Larger Sizes

International Nuclear Information System (INIS)

Liu, Q; Van Duzer, T; Fujiwara, K; Yoshikawa, N

2006-01-01

Recent progress on demonstrating components of the 64 kb Josephson-CMOS hybrid memory has encouraged exploration of the advancement possible with use of advanced technologies for both the Josephson and CMOS parts of the memory, as well as considerations of the effect of memory size on access time and power dissipation. The simulations to be reported depend on the use of an approximate model for 90 nm CMOS at 4 K. This model is an extension of the one we developed for 0.25 μm CMOS and have already verified. For the Josephson parts, we have chosen 20 kA/cm 2 technology, which was recently demonstrated. The calculations show that power dissipation and access time increase rather slowly with increasing size of the memory

Primary thymic extranodal marginal zone B cell lymphoma as an incidental finding in a Caucasian woman

DEFF Research Database (Denmark)

Krogh Petersen, Jeanette; Larsen, Thomas Stauffer; Møller, Michael Boe

2015-01-01

Primary thymic extranodal marginal zone B cell lymphoma (TML) is an extremely rare lymphoma strongly associated with autoimmune disease. We report an exceedingly rare case of TML found in a non-Asian population. TML was found incidentally in a 60-year-old Caucasian woman with a short history...

Thymic lesions and myasthenia gravis. Diagnosis based on mediastinal imaging and pathological findings

International Nuclear Information System (INIS)

Pirronti, T.; Rinaldi, P.; Marano, P.; Batocchi, A.P.; Evoli, A.; Di Schino, C.

2002-01-01

Purpose: To achieve a better understanding of the role of CT and MR imaging in the study of the mediastinum in patients with myasthenia gravis (MG). Material and Methods: Mediastinal CT and MR findings were correlated with the histopathological results in 104 thymectomized MG patients. Results: CT was performed in 104 patients; in 11 of them, MR was also carried out. 44 patients had hyperplasia at histology. On CT, thymic hyperplasia was confirmed in 16 cases, thymoma was diagnosed in 10 and a normal thymus in 18 (sensitivity 36%, specificity 95%). Of 52 patients with thymoma at histology, CT showed thymoma in 46, hyperplasia in 1, and normal thymus in 5. CT showed 88.5% sensitivity and 77% specificity for thymoma. In 10 patients with invasive thymoma, CT was indiscriminate, while invasiveness was detected in 7 cases at MR (70% sensitivity) and at CT in 1 case. Both CT and MR detected tumor recurrence in 5 cases, but the exact localization and degree of invasion were best defined by MR. Conclusion: In MG patients CT is a sensitive, specific and efficient modality for detecting thymoma, but is less so for detecting thymic hyperplasia. MR was shown to be accurate in detecting invasive thymoma both preoperatively and in postoperative follow-up

Thymic lesions and myasthenia gravis. Diagnosis based on mediastinal imaging and pathological findings

Energy Technology Data Exchange (ETDEWEB)

Pirronti, T.; Rinaldi, P.; Marano, P. [Univ. Cattolica del S. Cuore, Roma (Italy). Inst. of Radiology; Batocchi, A.P.; Evoli, A.; Di Schino, C. [Univ. Cattolica del S. Cuore, Roma (Italy). Inst. of Neurology

2002-07-01

Purpose: To achieve a better understanding of the role of CT and MR imaging in the study of the mediastinum in patients with myasthenia gravis (MG). Material and Methods: Mediastinal CT and MR findings were correlated with the histopathological results in 104 thymectomized MG patients. Results: CT was performed in 104 patients; in 11 of them, MR was also carried out. 44 patients had hyperplasia at histology. On CT, thymic hyperplasia was confirmed in 16 cases, thymoma was diagnosed in 10 and a normal thymus in 18 (sensitivity 36%, specificity 95%). Of 52 patients with thymoma at histology, CT showed thymoma in 46, hyperplasia in 1, and normal thymus in 5. CT showed 88.5% sensitivity and 77% specificity for thymoma. In 10 patients with invasive thymoma, CT was indiscriminate, while invasiveness was detected in 7 cases at MR (70% sensitivity) and at CT in 1 case. Both CT and MR detected tumor recurrence in 5 cases, but the exact localization and degree of invasion were best defined by MR. Conclusion: In MG patients CT is a sensitive, specific and efficient modality for detecting thymoma, but is less so for detecting thymic hyperplasia. MR was shown to be accurate in detecting invasive thymoma both preoperatively and in postoperative follow-up.

Synergistic action of radiation and chemical carcinogen in induction of thymic lymphoma in mice

International Nuclear Information System (INIS)

Kajitani, Takashi; Kamiya, Kenji; Seyama, Toshio; Ito, Takaaki; Yokoro, Kenjiro

1980-01-01

Young adult C57BL/6 female mice were used to study the induction of leukemia by a combined treatment of x-rays and N-nitrosoethylurea (NEU). Administration of NEU after x-ray irradiation induced the leukemia in 100% with shortening latent period, which indicated that the combined treatment enhanced the leukemia induction. Thymic localized X-irradiation decreased the leukemia induction ratio from 100 to 55% and prolonged the latent period from 86 days to 128 days, compared with the whole body irradiation. For whole body irradiation, thymus weights, cell counts, rates of DNA-synthesizing cells, and rates, of mitotic index were decreased markedly after irradiation. For thymus weights and cell counts minimum values were observed after 3 days, and recovered by 10 days. DNA-synthesizing cells and the rates of mitotic index began to increase from the minimum value at the first day to the maximum value at the 5th day after irradiation. By thymic localized irradiation, no marked damage nor recovering process could be followed. It was suggested that the administration of NEU after irradiation, especially, to the young recovering cells with high potential for proliferation derived the high induction rate of leukemia. (Nakanishi, T.)

Editorial Commentary: The Larger Holes or Larger Number of Holes We Drill in the Coracoid, the Weaker the Coracoid Becomes.

Science.gov (United States)

Brady, Paul

2016-06-01

The larger holes or larger number of holes we drill in the coracoid, the weaker the coracoid becomes. Thus, minimizing bone holes (both size and number) is required to lower risk of coracoid process fracture, in patients in whom transosseous shoulder acromioclavicular joint reconstruction is indicated. A single 2.4-mm-diameter tunnel drilled through both the clavicle and the coracoid lowers the risk of fracture, but the risk cannot be entirely eliminated. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Clinical application of SPECT-CT with 99mTc-Tektrotyd in bronchial and thymic neuroendocrine tumors (NETs).

Science.gov (United States)

Sergieva, Sonya; Robev, Bozhil; Dimcheva, Milena; Fakirova, Albena; Hristoskova, Radka

2016-01-01

Neuroendocrine tumors (NETs) of the thorax including bronchial and thymic tumors belong to foregut NETs. Limited loco-regional thoracic NETs can be resected with surgery, but in extensive metastatic disease the treatment is mainly palliative. A high incidence and density of somatostatin receptors (SSTR2, SSTR3, and SSTR5) are found in thoracic NETs. The purpose of this study was to evaluate the role of SPECT-CT somatostatin receptor scintigraphy (SRS) with 99mTc-Tektrotyd for imaging, staging and follow up of patients with bronchial and thymic neuroendocrine tumors. Forty-one patients with thoracic tumors with neuroendocrine differentiation were studied. Sixty-eight examinations including SPECT-CT studies of the neck and chest and/or abdomen and pelvis were carried out 2-4 hrs. post i.v. administration of aver-age 740 MBq activity dose of 99mTc-EDDA/HYNIC-TOC (Tektrotyd, Polatom). In all 41 investigated patients we obtained 81.25% (13/16), 88% (22/25) and 85.36% (35/41) of sensitivity, specificity and accuracy of this diagnostic approach, respectively. Somatostatin-receptor scintigraphy correctly identified all primary NETs located in the lungs and thymus. SPECT-CT studies with 99mTc-EDDA/HYNIC-TOC resulted in exact pre-surgical and pre-treatment N/M staging of bronchial and thymic NETs, except 2 cases with multiple hepatic metastases and 1 with massive suprarenal metastasis. It can be concluded that SPECT-CT with 99mTc-EDDA/HYNIC-TOC is a valuable tool for staging and follow-up of patients with thoracic NETs.

Deletion of Notch1 converts pro-T cells to dendritic cells and promotes thymic B cells by cell-extrinsic and cell-intrinsic mechanisms.

Science.gov (United States)

Feyerabend, Thorsten B; Terszowski, Grzegorz; Tietz, Annette; Blum, Carmen; Luche, Hervé; Gossler, Achim; Gale, Nicholas W; Radtke, Freddy; Fehling, Hans Jörg; Rodewald, Hans-Reimer

2009-01-16

Notch1 signaling is required for T cell development and has been implicated in fate decisions in the thymus. We showed that Notch1 deletion in progenitor T cells (pro-T cells) revealed their latent developmental potential toward becoming conventional and plasmacytoid dendritic cells. In addition, Notch1 deletion in pro-T cells resulted in large numbers of thymic B cells, previously explained by T-to-B cell fate conversion. Single-cell genotyping showed, however, that the majority of these thymic B cells arose from Notch1-sufficient cells by a cell-extrinsic pathway. Fate switching nevertheless exists for a subset of thymic B cells originating from Notch1-deleted pro-T cells. Chimeric mice lacking the Notch ligand delta-like 4 (Dll4) in thymus epithelium revealed an essential role for Dll4 in T cell development. Thus, Notch1-Dll4 signaling fortifies T cell commitment by suppressing non-T cell lineage potential in pro-T cells, and normal Notch1-driven T cell development repels excessive B cells in the thymus.

Radiotherapy for invasive thymoma and thymic carcinoma. Clinicopathological review

Energy Technology Data Exchange (ETDEWEB)

Mayer, R.; Stuecklschweiger, G.F.; Prettenhofer, U.; Stranzl, H.; Hackl, A. [Univ. Graz (Austria). Dept. of Radiotherapy; Beham-Schmid, C. [Univ. Graz (Austria). Dept. of Pathology; Groell, R. [Univ. Graz (Austria). Dept. of Radiology; Smolle-Juettner, F.M.; Renner, H. [Univ. Graz (Austria). Dept. of Thoracic and Hyperbaric Surgery; Quehenberger, F. [Univ. Graz (Austria). Dept. of Medical Informatics, Statistics and Documentation

1999-06-01

All 33 patients were irradiated with a mean dose of 50 Gy after complete resection (16 patients), partial resection (9 patients) of biopsy (8 patients). Staging was done according to the Masaoka classification; there were 12 Stage II, 12 Stage III and 9 Stage IV patients. Results: In patients with invasive thymoma Stage II to IV (median follow-up 54.4 months) Kaplan-Meier estimates of overall survival (OS), disease-specific (DSS) and disease-free survival (DFS) at 5 years were 63.7% (95% confidence interval [CI], 42 to 84%), 88.3% (CI, 75 to 100%) and 77,4% (CI, 58 to 95%), respectively. Among the prognostic factors tested, such as age, myasthenia gravis, completeness of surgery and histologic subclassification, total radiation dose, and Masaoka Stage, the latter was the only significant predictor of improved survival (p=0.04). Considering local control, radiation dose was a significant prognostic factor (p=0.0006). In patients with thymic carcinoma (median follow-up 43.4 months) 5 year DSS, and DFS were 22.2% (CI, 0 to 60%) and 16.7% (CI, 0 to 46%), respectively. Thymoma as compared to thymic carcinoma had a statistically significant better DSS (p=0.007) and DFS (p=0.0007). Conclusion: Postoperative radiotherapy with sufficient doses plays an important role as adjuvant treatment in complete or incomplete resected invasive Stage II to III thymoma. In unresectable thymoma Stage III to IV as well as in thymic carcinoma a multimodality approach should be considered to improve survival. (orig.) [Deutsch] Alle 33 Patienten wurden nach kompletter Resektion (n=16), Teilresektion (n=9) oder Biopsie (n=8) mit einer mittleren Dosis von 50 Gy (30 bis 60 Gy) bestrahlt. Die Stadieneinteilung nach Masaoka ergab jeweils zwoelf Patienten in Stadium II und III sowie neun Patienten im Stadium IV. Ergebnisse: Patienten mit einem invasivem Thymom Masaoka-Stadium II bis IV (mediane Nachsorgezeit 54,4 Monate) hatten ein Fuenf-Jahres-Gesamtueberleben, krankheitsspezifisches und

Inhibitory effects of a polypeptide thymic factor on the development of 7,12-dimethylbenz(a)anthragene-induced mammary adenocarcinoma in female rats

Energy Technology Data Exchange (ETDEWEB)

Anisimov, V.N.; Danetskaya, E.V.; Morozov, V.G.; Khavinson, V.Kh.

1980-01-01

It has come to be recognized that tumor growth is accompanied by inhibition of cellular immunity and the function of the T lymphocytes. Restitution of T lymphocyte function by means of several pharmacologic agents such as levamisole, phenformin, or epithalamin (an epiphyseal factor) has, in a number of cases, been accompanied by growth inhibition of both spontaneous and induced tumors. In addition, the importance of the thymus in the regulation of T lymphocytes and in antitumor immunity has been recognized. Several indicators point to the fact that the thymus contains physiologically active substances which stimulate T cell-dependent immunity and prevent the occurrence of neoplasms. These considerations have led to attempts at isolation of active thymic factors and studies on their effects on the appearance and growth of tumors. Previously, a thymic factor - thymarin - had been isolated which imparted immunocompetence to the T lymphocytes. This factor differs from other thymic preparations, including thymosine, in terms of a number of physicochemical characteristics and is a polypeptide with a molecular weight of 5000. This study is concerned with its effects on tumor development - mammary gland adenocarcinoma induced in animals with a chemical carcinogen.

Why have microsaccades become larger?

DEFF Research Database (Denmark)

Hansen, Dan Witzner; Nyström, Marcus; Andersson, Richard

2014-01-01

-trackers compared to the systems used in the classical studies, in combination with the lack of a systematic algorithmic treatment of the overshoot. We hope that awareness of these discrepancies in microsaccade dynamics across eye structures will lead to more generally accepted definitions of microsaccades....... experts. The main reason was that the overshoots were not systematically detected by the algorithm and therefore not accurately accounted for. We conclude that one reason to why the reported size of microsaccades has increased is due to the larger overshoots produced by the modern pupil-based eye...

Analysis of early initiating event(s) in radiation-induced thymic lymphomagenesis

International Nuclear Information System (INIS)

Muto, Masahiro; Ying Chen; Kubo, Eiko; Mita, Kazuei

1996-01-01

Since the T cell receptor rearrangement is a sequential process and unique to the progeny of each clone, we investigated the early initiating events in radiation-induced thymic lymphomagenesis by comparing the oncogenic alterations with the pattern of γ T cell receptor (TCR) rearrangements. We reported previously that after leukemogenic irradiation, preneoplastic cells developed, albeit infrequently, from thymic leukemia antigen-2 + (TL-2 + ) thymocytes. Limited numbers of TL-2 + cells from individual irradiated B10.Thy-1.1 mice were injected into B10.Thy-1.2 mice intrathymically, and the common genetic changes among the donor-type T cell lymphomas were investigated with regard to p53 gene and chromosome aberrations. The results indicated that some mutations in the p53 gene had taken place in these lymphomas, but there was no common mutation among the donor-type lymphomas from individual irradiated mice, suggesting that these mutations were late-occurring events in the process of oncogenesis. On the other hand, there were common chromosome aberrations or translocations such as trisomy 15, t(7F; 10C), t(1A; 13D) or t(6A; XB) among the donor-type lymphomas derived from half of the individual irradiated mice. This indicated that the aberrations/translocations, which occurred in single progenitor cells at the early T cell differentiation either just before or after γ T cell receptor rearrangements, might be important candidates for initiating events. In the donor-type lymphomas from the other half of the individual irradiated mice, microgenetic changes were suggested to be initial events and also might take place in single progenitor cells just before or right after γ TCR rearrangements. (author)

Diffusion of two-dimensional epitaxial clusters on metal (100) surfaces: Facile versus nucleation-mediated behavior and their merging for larger sizes

International Nuclear Information System (INIS)

Lai, King C.; Liu, Da-Jiang; Evans, James W.

2017-01-01

For diffusion of two-dimensional homoepitaxial clusters of N atoms on metal(100) surfaces mediated by edge atom hopping, macroscale continuum theory suggests that the diffusion coefficient scales like DN ~ N -β with β = 3/2. However, we find quite different and diverse behavior in multiple size regimes. These include: (i) facile diffusion for small sizes N < 9; (ii) slow nucleation-mediated diffusion with small β < 1 for “perfect” sizes N = N p = L 2 or L(L+1), for L = 3, 4,… having unique ground state shapes, for moderate sizes 9 ≤ N ≤ O(10 2 ); the same also applies for N = N p +3, N p + 4,… (iii) facile diffusion but with large β > 2 for N = Np + 1 and N p + 2 also for moderate sizes 9 ≤ N ≤ O(10 2 ); (iv) merging of the above distinct branches and subsequent anomalous scaling with 1 ≲ β < 3/2, reflecting the quasi-facetted structure of clusters, for larger N = O(10 2 ) to N = O(10 3 ); and (v) classic scaling with β = 3/2 for very large N = O(103) and above. The specified size ranges apply for typical model parameters. We focus on the moderate size regime where show that diffusivity cycles quasi-periodically from the slowest branch for N p + 3 (not Np) to the fastest branch for Np + 1. Behavior is quantified by Kinetic Monte Carlo simulation of an appropriate stochastic lattice-gas model. However, precise analysis must account for a strong enhancement of diffusivity for short time increments due to back-correlation in the cluster motion. Further understanding of this enhancement, of anomalous size scaling behavior, and of the merging of various branches, is facilitated by combinatorial analysis of the number of the ground state and low-lying excited state cluster configurations, and also of kink populations.

Thymic lymphocytes. III. Cooperative phenomenon in the proliferation of thymocytes under Con A stimulation.

Science.gov (United States)

Papiernik, M; Jacobson, J B

1986-01-01

In the present paper, the response of thymocytes to Con A is analyzed in terms of a cooperative phenomenon between medullary thymocytes, cortical thymocytes, thymic accessory cells, and interleukin 2. Medullary thymocytes respond spontaneously to Con A and produce IL-2. The addition of exogenously produced IL-2 enhances their proliferation. Small numbers of cortical (PNA+) thymocytes do not respond to Con A, even in the presence of IL-2-containing supernatant. By increasing the number of PNA+ cells per well, sensitivity to Con A and IL-2 appears. This response may be linked either to the increase in a minor PNA+-responding population and/or to the enhanced contamination by medullary thymocytes and macrophages in non-responding PNA+ thymocyte population. In this hypothesis, either the contaminating cells respond by themselves and/or cooperate with PNA+ cells to induce their proliferation. Coculture of non-responding low numbers of PNA+ thymocytes with Con A- and IL-2-containing supernatant in the presence of PNA- cells containing thymic medullary thymocytes and macrophages always produces a higher response than that of each individual population. These results show that a cooperative phenomenon occurs in the cocultures of PNA+ and PNA- thymic cells. We can show using PNA+ and PNA- thymocytes with different Thy 1 alleles, that indeed both PNA+ and populations participate PNA-thymocytes with different Thy 1 alleles, that indeed both PNA+ and PNA- populations participate in the generation of proliferating cells. We can demonstrate, by lysis experiments with monoclonal antibodies and complement that at the end of coculture, most of the proliferating cells are Lyt 1+, and part are Lyt 2+ or L3T4+. We discuss the fact that the phenotype of the cells after activation does not allow us to deduce the phenotype of their precursors. Lysis of Ia+ cells prior to coculture, reduces the level of the proliferative response but does not modify the percentage of cooperation produced

B and T lymphocytes in man. I. Effect of infant thymic irradiation on the circulating B and T lymphocytes

International Nuclear Information System (INIS)

Reddy, M.M.; Goh, K.; Hempelmann, L.H.

1976-01-01

B and T lymphocytes were studied in a group of adults whose thymic glands were irradiated in infancy for alleged thymic enlargement. Two independent methods were used to determine the B and T lymphocytes from each peripheral blood specimen: (1) the relative proportion of cells with surface immunoglobulins (B lymphocytes) and cells forming rosettes with sheep erythrocytes (T lymphocytes); and (2) the relative mitogenic response to phytohemagglutinin (T lymphocytes) and to pokeweed mitogen (B lymphocytes). All specimens were coded. The results obtained indicate: (1) a reduction of B and T lymphocytes; and (2) a decreased mitogenic response of lymphocytes to phytohemagglutinin and pokeweed mitogen in this group of patients as compared with the controls. These observations suggest that (1) the effect of irradiation to the thymus gland on lymphocytes is long lasting and (2) both B and T lymphocytes are affected by irradiation to the thymus gland

Modulatory effects of cAMP and PKC activation on gap junctional intercellular communication among thymic epithelial cells

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Neves-dos-Santos Sandra

2010-01-01

Full Text Available Abstract Background We investigated the effects of the signaling molecules, cyclic AMP (cAMP and protein-kinase C (PKC, on gap junctional intercellular communication (GJIC between thymic epithelial cells (TEC. Results Treatment with 8-Br-cAMP, a cAMP analog; or forskolin, which stimulates cAMP production, resulted in an increase in dye transfer between adjacent TEC, inducing a three-fold enhancement in the mean fluorescence of coupled cells, ascertained by flow cytometry after calcein transfer. These treatments also increased Cx43 mRNA expression, and stimulated Cx43 protein accumulation in regions of intercellular contacts. VIP, adenosine, and epinephrine which may also signal through cyclic nucleotides were tested. The first two molecules did not mimic the effects of 8-Br-cAMP, however epinephrine was able to increase GJIC suggesting that this molecule functions as an endogenous inter-TEC GJIC modulators. Stimulation of PKC by phorbol-myristate-acetate inhibited inter-TEC GJIC. Importantly, both the enhancing and the decreasing effects, respectively induced by cAMP and PKC, were observed in both mouse and human TEC preparations. Lastly, experiments using mouse thymocyte/TEC heterocellular co-cultures suggested that the presence of thymocytes does not affect the degree of inter-TEC GJIC. Conclusions Overall, our data indicate that cAMP and PKC intracellular pathways are involved in the homeostatic control of the gap junction-mediated communication in the thymic epithelium, exerting respectively a positive and negative role upon cell coupling. This control is phylogenetically conserved in the thymus, since it was seen in both mouse and human TEC preparations. Lastly, our work provides new clues for a better understanding of how the thymic epithelial network can work as a physiological syncytium.

Critical role for thymic CD19+CD5+CD1dhiIL-10+ regulatory B cells in immune homeostasis.

Science.gov (United States)

Xing, Chen; Ma, Ning; Xiao, He; Wang, Xiaoqian; Zheng, Mingke; Han, Gencheng; Chen, Guojiang; Hou, Chunmei; Shen, Beifen; Li, Yan; Wang, Renxi

2015-03-01

This study tested the hypothesis that besides the spleen, LNs, peripheral blood, and thymus contain a regulatory IL-10-producing CD19(+)CD5(+)CD1d(high) B cell subset that may play a critical role in the maintenance of immune homeostasis. Indeed, this population was identified in the murine thymus, and furthermore, when cocultured with CD4(+) T cells, this population of B cells supported the maintenance of CD4(+)Foxp3(+) Tregs in vitro, in part, via the CD5-CD72 interaction. Mice homozygous for Cd19(Cre) (CD19(-/-)) express B cells with impaired signaling and humoral responses. Strikingly, CD19(-/-) mice produce fewer CD4(+)Foxp3(+) Tregs and a greater percentage of CD4(+)CD8(-) and CD4(-)CD8(+) T cells. Consistent with these results, transfer of thymic CD19(+)CD5(+)CD1d(hi) B cells into CD19(-/-) mice resulted in significantly up-regulated numbers of CD4(+)Foxp3(+) Tregs with a concomitant reduction in CD4(+)CD8(-) and CD4(-)CD8(+) T cell populations in the thymus, spleen, and LNs but not in the BM of recipient mice. In addition, thymic CD19(+)CD5(+)CD1d(hi) B cells significantly suppressed autoimmune responses in lupus-like mice via up-regulation of CD4(+)Foxp3(+) Tregs and IL-10-producing Bregs. This study suggests that thymic CD19(+)CD5(+)CD1d(hi)IL-10(+) Bregs play a critical role in the maintenance of immune homeostasis. © Society for Leukocyte Biology.

Homeostatic properties and phenotypic maturation of murine CD4+ pre-thymic emigrants in the thymus.

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Jie Dong

Full Text Available After a tightly regulated developmental program in the thymus, "mature" single positive (SP thymocytes leave the thymus and enter the periphery. These newly arrived recent thymic emigrants (RTEs are phenotypically and functionally immature, and will complete a dynamic maturation in the peripheral lymphoid organs before being licensed to be resident naïve T cells. To study the early events occurring in the RTE maturation process, we identified the phenotype of CD4(+ pre-RTEs, a population of CD4(+ SP thymocytes that have acquired the thymus egress capability. Compared to peripheral naïve T cells, CD4(+ pre-RTEs displayed superior survival capability in lymphoreplete mice and faster proliferation under lymphopenic condition. The differences in Bcl2/Bim expression and/or heightened IL-7 signaling pathway may account for the pre-RTEs' better responsiveness to homeostatic signals. Qa2, the expression of which indicates the phenotypic maturation of SPs and RTEs, was found to be upregulated in CD4(+ pre-RTEs in thymic perivascular space. Migratory dendritic cells that surround this region contribute to Qa2 expression in pre-RTEs. The dendritic cell-driven Qa2 induction of CD4(+ pre-RTEs is independent of MHC class II and Aire molecules.

Is a positron emission tomography-computed tomography scan useful in the staging of thymic epithelial neoplasms?

Science.gov (United States)

Viti, Andrea; Terzi, Alberto; Bianchi, Andrea; Bertolaccini, Luca

2014-07-01

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed concerned the employment of 18-fluorine fluorodeoxyglucose positron emission tomography/computed tomography (PET-CT) in the preoperative evaluation of thymic epithelial neoplasms (TENs). We reviewed its role as a predictor of Masaoka stage and histology (according to the WHO). In clinical practice, stage is considered the most important determinant in the therapeutic approach. A total of 265 papers were found as a result of the reported search, of which 14 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All the studies are retrospective analyses. Patient numbers varied from 13 to 58. Our research showed that PET-CT could clearly add information about the histology of the tumour. Thymic carcinoma constantly showed a higher standard uptake value (SUVmax) than thymomas. Furthermore, in one retrospective study of 36 patients, when using a derived PET indicator, the T/M ratio (ratio between SUVmax of the tumour and SUVmax of mediastinum, as conventionally measured at the level of the aortic arc), PET-CT could also differentiate between low- and high-risk thymomas (low risk vs high risk P = 0.01). In another study, a cut-off value of T/M ratio of 2.75 was identified between low- and high-risk TENs. The role of PET-CT in prediction of stage is harder to recognize. In one study, there was a statistically significant correlation between SUVmax, T/M ratio and Masaoka stage (P = 0.781 and 0.718, respectively). When analysing the data from the three larger series on this topic (58, 51 and 47 patients, the latter group selected in a multicentre study), only one study identified a correlation between SUVmax and Masaoka stage (Spearman correlation coefficient 0.30, P = 0.0436), while the other two failed

Larger Bowl Size Increases the Amount of Cereal Children Request, Consume, and Waste

NARCIS (Netherlands)

Wansink, Brian; van Ittersum, Koert; Payne, Collin R.

Objective To examine whether larger bowls bias children toward requesting more food from the adults who serve them. Study design Study 1 was a between-subject design involving 69 preschool-age children who were randomized to receive either a small (8 oz) or large (16 oz) cereal bowl and were asked

In vitro evidence for participation of DEC-205 expressed by thymic cortical epithelial cells in clearance of apoptotic thymocytes.

NARCIS (Netherlands)

Small, M; Kraal, G.

2003-01-01

Binding of apoptotic cells was compared after incubation of thymocytes with two clones of murine thymic stromal cells to which CD4(+)/CD8(+) thymocytes attach. With the BA/10, but not the BA/2, clone, thymocytes with apoptotic morphology were bound irreversibly. These tightly bound thymocytes were

Impaired progenitor cell function in HIV-negative infants of HIV-positive mothers results in decreased thymic output and low CD4 counts

DEFF Research Database (Denmark)

Nielsen, S. D.; Jeppesen, D. L.; Kolte, L.

2001-01-01

and fetal thymic organ cultures (FTOCs). Lower naive CD4 counts (459.3 +/- 68.9 vs 1128.9 +/- 146.8 cells/microL, P mothers were found (frequency of CD4(+) cells with TRECs was 3.6% +/- 0.7% compared with 14.3% +/- 2.2% in controls, P ...). In combination with lower red blood cell counts in infants of HIV-positive mothers, this finding suggested impairment of progenitor cell function. Indeed, progenitors from infants of HIV-positive mothers had decreased cloning efficiency (15.7% +/- 2.6% vs 55.8% +/- 15.9%, P =.009) and seemed to generate fewer T...... cells in FTOCs. In conclusion, lower numbers of naive CD4(+) cells and reduced thymic output in HIV-negative infants of HIV-positive mothers may be due to impaired progenitor cell function....

T-cell receptor excision circles (TREC) in CD4+ and CD8+ T-cell subpopulations in atopic dermatitis and psoriasis show major differences in the emission of recent thymic emigrants

DEFF Research Database (Denmark)

Just, Helle L; Deleuran, Mette; Vestergaard, Christian

2008-01-01

. In contrast, both men and women with psoriasis had significantly reduced TREC levels, which were, on average, only 30% of that of healthy persons. In atopic dermatitis the levels of TREC declined with increasing levels of IgE, disease intensity and extent of eczema. Furthermore, patients with atopic......-cells, this indicates that atopic dermatitis patients can have compensatory emissions of thymic emigrants, whereas psoriatic patients do not, thus supporting different thymic function in these two diseases....

Effect of Boron on Thymic Cytokine Expression, Hormone Secretion, Antioxidant Functions, Cell Proliferation, and Apoptosis Potential via the Extracellular Signal-Regulated Kinases 1 and 2 Signaling Pathway.

Science.gov (United States)

Jin, Erhui; Ren, Man; Liu, Wenwen; Liang, Shuang; Hu, Qianqian; Gu, Youfang; Li, Shenghe

2017-12-27

Boron is an essential trace element in animals. Appropriate boron supplementation can promote thymus development; however, a high dose of boron can lead to adverse effects and cause toxicity. The influencing mechanism of boron on the animal body remains unclear. In this study, we examined the effect of boron on cytokine expression, thymosin and thymopoietin secretion, antioxidant function, cell proliferation and apoptosis, and extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway in the thymus of rats. We found that supplementation with 10 and 20 mg/L boron to the drinking water significantly elevated levels of interleukin 2 (IL-2), interferon γ (IFN-γ), interleukin 4 (IL-4), and thymosin α1 in the thymus of rats (p boron had no apparent effect on many of the above indicators. In contrast, supplementation with 480 and 640 mg/L boron had the opposite effect on the above indicators in rats and elevated levels of pro-inflammatory cytokines, such as interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor α (TNF-α) (p boron to the drinking water had a U-shaped dose-effect relationship with thymic cytokine expression, hormone secretion, antioxidant function, cell proliferation, and apoptosis. Specifically, supplementation with 10 and 20 mg/L boron promoted thymocyte proliferation and enhanced thymic functions. However, supplementation with 480 and 640 mg/L boron inhibited thymic functions and increased the number of apoptotic thymocytes, suggesting that the effects of boron on thymic functions may be caused via the ERK1/2 signaling pathway.

Thymic Nurse Cells Participate in Heterotypic Internalization and Repertoire Selection of Immature Thymocytes; Their Removal from the Thymus of Autoimmune Animals May be Important to Disease Etiology.

Science.gov (United States)

Guyden, J C; Martinez, M; Chilukuri, R V E; Reid, V; Kelly, F; Samms, M-O D

2015-01-01

Thymic nurse cells (TNCs) are specialized epithelial cells that reside in the thymic cortex. The initial report of their discovery in 1980 showed TNCs to contain up to 200 thymocytes within specialized vacuoles in their cytoplasm. Much has been reported since that time to determine the function of this heterotypic internalization event that exists between TNCs and developing thymocytes. In this review, we discuss the literature reported that describes the internalization event and the role TNCs play during T cell development in the thymus as well as why these multicellular complexes may be important in inhibiting the development of autoimmune diseases.

Dairy farmers with larger herd sizes adopt more precision dairy technologies.

Science.gov (United States)

Gargiulo, J I; Eastwood, C R; Garcia, S C; Lyons, N A

2018-06-01

An increase in the average herd size on Australian dairy farms has also increased the labor and animal management pressure on farmers, thus potentially encouraging the adoption of precision technologies for enhanced management control. A survey was undertaken in 2015 in Australia to identify the relationship between herd size, current precision technology adoption, and perception of the future of precision technologies. Additionally, differences between farmers and service providers in relation to perception of future precision technology adoption were also investigated. Responses from 199 dairy farmers, and 102 service providers, were collected between May and August 2015 via an anonymous Internet-based questionnaire. Of the 199 dairy farmer responses, 10.4% corresponded to farms that had fewer than 150 cows, 37.7% had 151 to 300 cows, 35.5% had 301 to 500 cows; 6.0% had 501 to 700 cows, and 10.4% had more than 701 cows. The results showed that farmers with more than 500 cows adopted between 2 and 5 times more specific precision technologies, such as automatic cup removers, automatic milk plant wash systems, electronic cow identification systems and herd management software, when compared with smaller farms. Only minor differences were detected in perception of the future of precision technologies between either herd size or farmers and service providers. In particular, service providers expected a higher adoption of automatic milking and walk over weighing systems than farmers. Currently, the adoption of precision technology has mostly been of the type that reduces labor needs; however, respondents indicated that by 2025 adoption of data capturing technology for monitoring farm system parameters would be increased. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Visual exposure to large and small portion sizes and perceptions of portion size normality: Three experimental studies.

Science.gov (United States)

Robinson, Eric; Oldham, Melissa; Cuckson, Imogen; Brunstrom, Jeffrey M; Rogers, Peter J; Hardman, Charlotte A

2016-03-01

Portion sizes of many foods have increased in recent times. In three studies we examined the effect that repeated visual exposure to larger versus smaller food portion sizes has on perceptions of what constitutes a normal-sized food portion and measures of portion size selection. In studies 1 and 2 participants were visually exposed to images of large or small portions of spaghetti bolognese, before making evaluations about an image of an intermediate sized portion of the same food. In study 3 participants were exposed to images of large or small portions of a snack food before selecting a portion size of snack food to consume. Across the three studies, visual exposure to larger as opposed to smaller portion sizes resulted in participants considering a normal portion of food to be larger than a reference intermediate sized portion. In studies 1 and 2 visual exposure to larger portion sizes also increased the size of self-reported ideal meal size. In study 3 visual exposure to larger portion sizes of a snack food did not affect how much of that food participants subsequently served themselves and ate. Visual exposure to larger portion sizes may adjust visual perceptions of what constitutes a 'normal' sized portion. However, we did not find evidence that visual exposure to larger portions altered snack food intake. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Thymic and lymph node mesenchymal subsets can be derived from PDGFRα/β+Gp38+CD34+ICAM1- vascular adventitial precursors

DEFF Research Database (Denmark)

Sitnik, Katarzyna Maria; Wendland, Kerstin; Weishaupt, Holger

While discrete Gp38- and Gp38+ mesenchymal populations have previously been described in the lymph nodes (LNs) and in the thymus the putative relationship between LN and thymic mesenchymal cells remains unclear. Here, using transcriptome profiling as well as phenotypic and localization studies we...

Song repertoire size correlates with measures of body size in Eurasian blackbirds

DEFF Research Database (Denmark)

Hesler, Nana; Mundry, Roger; Sacher, Thomas

2012-01-01

In most oscine bird species males possess a repertoire of different song patterns. The size of these repertoires is assumed to serve as an honest signal of male quality. The Eurasian blackbird’s (Turdus merula) song contains a large repertoire of different element types with a flexible song...... organisation. Here we investigated whether repertoire size in Eurasian blackbirds correlates with measures of body size, namely length of wing, 8th primary, beak and tarsus. So far, very few studies have investigated species with large repertoires and a flexible song organisation in this context. We found...... positive correlations, meaning that larger males had larger repertoires. Larger males may have better fighting abilities and, thus, advantages in territorial defence. Larger structural body size may also reflect better conditions during early development. Therefore, under the assumption that body size...

Surgical outcome of primary clipping for anterior circulation aneurysms of size 2 centimeters or larger.

Science.gov (United States)

Furtado, Sunil V; Saikiran, Narayanam A; Thakar, Sumit; Dadlani, Ravi; Mohan, Dilip; Aryan, Saritha; Hegde, Alangar S

2014-07-01

Aneurysms of the anterior circulation larger than 2cm have a complex relationship to the anterior skull base, requiring a multi-modality management approach. This retrospective study of 54 patients with such aneurysms who underwent clipping between 2001 and 2012 analyzes clinical and surgical data, aneurysm characteristics and correlates them with respect to the Glasgow outcome score at follow-up and immediate post-operative clinical status. Patients with an outcome score of 5 or 4 were categorized as "good", while those with score 3-1 were "poor". Fisher's exact test and paired T-test (p<0.5) were used to test statistical significance for discrete and continuous variables respectively. 44 (81.4%) patients had a good outcome. Patients with non-ophthalmic/paraclinoid aneurysms had significantly lower incidence of adverse intra-operative events (p=0.035). Patients older than 50 years (p=0.045), with adverse intra-operative events (p=0.015) and post-operative infarction (p<0.001) had a poor outcome compared to those younger than 50 years age and those without adverse intra-operative events or infarctions. The grouped age variable had maximum influence on patient outcome. Location and size of aneurysm did not have an overall impact on surgical outcome. There were 4 mortalities. Primary clipping of proximal non-cavernous aneurysms on the internal carotid artery is associated with adverse intra-operative events. A multi-modality treatment approach in these aneurysms should be individualized, more so in patients older than 50 years. Copyright © 2014 Elsevier B.V. All rights reserved.

SME routes for innovation collaboration with larger enterprises

DEFF Research Database (Denmark)

Brink, Tove

2017-01-01

The research in this paper reveals how Small and Medium-sized Enterprises (SMEs) can contribute to industry competiveness through collaboration with larger enterprises. The research is based on a longitudinal qualitative case study starting in 2011 with 10 SME offshore wind farm suppliers...... and follow-up interviews in 2013. The research continued with a second approach in 2014 within operation and maintenance (O&M) through focus group interviews and subsequent individual interviews with 20 enterprises and a seminar in May 2015. The findings reveal opportunities and challenges for SMEs according...... to three different routes for cooperation and collaboration with larger enterprises: demand-driven cooperation, supplier-driven cooperation and partnerdriven collaboration. The SME contribution to innovation and competiveness is different within the three routes and ranges from providing specific knowledge...

Demonstrating the value of larger ensembles in forecasting physical systems

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Reason L. Machete

2016-12-01

Full Text Available Ensemble simulation propagates a collection of initial states forward in time in a Monte Carlo fashion. Depending on the fidelity of the model and the properties of the initial ensemble, the goal of ensemble simulation can range from merely quantifying variations in the sensitivity of the model all the way to providing actionable probability forecasts of the future. Whatever the goal is, success depends on the properties of the ensemble, and there is a longstanding discussion in meteorology as to the size of initial condition ensemble most appropriate for Numerical Weather Prediction. In terms of resource allocation: how is one to divide finite computing resources between model complexity, ensemble size, data assimilation and other components of the forecast system. One wishes to avoid undersampling information available from the model's dynamics, yet one also wishes to use the highest fidelity model available. Arguably, a higher fidelity model can better exploit a larger ensemble; nevertheless it is often suggested that a relatively small ensemble, say ~16 members, is sufficient and that larger ensembles are not an effective investment of resources. This claim is shown to be dubious when the goal is probabilistic forecasting, even in settings where the forecast model is informative but imperfect. Probability forecasts for a ‘simple’ physical system are evaluated at different lead times; ensembles of up to 256 members are considered. The pure density estimation context (where ensemble members are drawn from the same underlying distribution as the target differs from the forecasting context, where one is given a high fidelity (but imperfect model. In the forecasting context, the information provided by additional members depends also on the fidelity of the model, the ensemble formation scheme (data assimilation, the ensemble interpretation and the nature of the observational noise. The effect of increasing the ensemble size is quantified by

Generation of Functional Thymic Epithelium from Human Embryonic Stem Cells that Supports Host T Cell Development

OpenAIRE

Parent, Audrey V.; Russ, Holger A.; Khan, Imran S.; LaFlam, Taylor N.; Metzger, Todd C.; Anderson, Mark S.; Hebrok, Matthias

2013-01-01

Inducing immune tolerance to prevent rejection is a key step toward successful engraftment of stem-cell-derived tissue in a clinical setting. Using human pluripotent stem cells to generate thymic epithelial cells (TECs) capable of supporting T cell development represents a promising approach to reach this goal; however, progress toward generating functional TECs has been limited. Here, we describe a robust in vitro method to direct differentiation of human embryonic stem cells (hESCs) into th...

Growth hormone in the presence of laminin modulates interaction of human thymic epithelial cells and thymocytes in vitro

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Marvin Paulo Lins

Full Text Available BACKGROUND: Several evidences indicate that hormones and neuropeptides function as immunomodulators. Among these, growth hormone (GH is known to act on the thymic microenvironment, supporting its role in thymocyte differentiation. The aim of this study was to evaluate the effect of GH on human thymocytes and thymic epithelial cells (TEC in the presence of laminin. RESULTS: GH increased thymocyte adhesion on BSA-coated and further on laminin-coated surfaces. The number of migrating cells in laminin-coated membrane was higher in GH-treated thymocyte group. In both results, VLA-6 expression on thymocytes was constant. Also, treatment with GH enhanced laminin production by TEC after 24 h in culture. However, VLA-6 integrin expression on TEC remained unchanged. Finally, TEC/thymocyte co-culture model demonstrated that GH elevated absolute number of double-negative (CD4-CD8- and single-positive CD4+ and CD8+ thymocytes. A decrease in cell number was noted in double-positive (CD4+CD8+ thymocytes. CONCLUSIONS: The results of this study demonstrate that GH is capable of enhancing the migratory capacity of human thymocytes in the presence of laminin and promotes modulation of thymocyte subsets after co-culture with TEC.

Kepler Mission: a Discovery-Class Mission Designed to Determine the Frequency of Earth-Size and Larger Planets Around Solar-Like Stars

Science.gov (United States)

Borucki, William; Koch, David; Lissauer, Jack; Basri, Gibor; Caldwell, John; Cochran, William; Dunham, Edward W.; Gilliland, Ronald; Caldwell, Douglas; Kondo, Yoji;

Differentiating the grades of thymic epithelial tumor malignancy using textural features of intratumoral heterogeneity via (18)F-FDG PET/CT.

Science.gov (United States)

Lee, Hyo Sang; Oh, Jungsu S; Park, Young Soo; Jang, Se Jin; Choi, Ik Soo; Ryu, Jin-Sook

2016-05-01

We aimed to explore the ability of textural heterogeneity indices determined by (18)F-FDG PET/CT for grading the malignancy of thymic epithelial tumors (TETs). We retrospectively enrolled 47 patients with pathologically proven TETs who underwent pre-treatment (18)F-FDG PET/CT. TETs were classified by pathological results into three subgroups with increasing grades of malignancy: low-risk thymoma (LRT; WHO classification A, AB and B1), high-risk thymoma (B2 and B3), and thymic carcinoma (TC). Using (18)F-FDG PET/CT, we obtained conventional imaging indices including SUVmax and 20 intratumoral heterogeneity indices: i.e., four local-scale indices derived from the neighborhood gray-tone difference matrix (NGTDM), eight regional-scale indices from the gray-level run-length matrix (GLRLM), and eight regional-scale indices from the gray-level size zone matrix (GLSZM). Area under the receiver operating characteristic curve (AUC) was used to demonstrate the abilities of the imaging indices for differentiating subgroups. Multivariable logistic regression analysis was performed to show the independent significance of the textural indices. Combined criteria using optimal cutoff values of the SUVmax and a best-performing heterogeneity index were applied to investigate whether they improved differentiation between the subgroups. Most of the GLRLM and GLSZM indices and the SUVmax showed good or fair discrimination (AUC >0.7) with best performance for some of the GLRLM indices and the SUVmax, whereas the NGTDM indices showed relatively inferior performance. The discriminative ability of some of the GLSZM indices was independent from that of SUVmax in multivariate analysis. Combined use of the SUVmax and a GLSZM index improved positive predictive values for LRT and TC. Texture analysis of (18)F-FDG PET/CT scans has the potential to differentiate between TET tumor grades; regional-scale indices from GLRLM and GLSZM perform better than local-scale indices from the NGTDM. The SUVmax

A comparative study of PD-L1 immunohistochemical assays with four reliable antibodies in thymic carcinoma.

Science.gov (United States)

Sakane, Tadashi; Murase, Takayuki; Okuda, Katsuhiro; Takino, Hisashi; Masaki, Ayako; Oda, Risa; Watanabe, Takuya; Kawano, Osamu; Haneda, Hiroshi; Moriyama, Satoru; Saito, Yushi; Yamada, Takeshi; Nakanishi, Ryoichi; Inagaki, Hiroshi

2018-01-23

Currently, four immunohistochemical assays are registered with the US Food and Drug Administration to detect the expression of PD-L1. We investigated the PD-L1 expression in thymic carcinomas using these four diagnostic assays. The cases of 53 patients were reviewed and their specimens were subjected to four PD-L1 assays with different antibodies (SP142, SP263, 22C3, and 28-8). The PD-L1 expression in tumor cells (TCs) and immune cells (ICs) was evaluated. In TCs, the four assays showed similar scores in each case. Histopathologically, high TC scores were observed in squamous cell carcinomas (SqCCs). Meanwhile, there were no significant relationships among the IC scores in the four assays. In SqCCs, the high expression of PD-L1 (defined as ≥50% TC score) in TCs tended to be associated with early stage cancer. The patients with high expression levels of PD-L1 tended to show longer overall survival in the 22C3 assays (p=0.0200). In thymic carcinomas, the staining pattern showed high concordance among the four assays when TCs - rather than ICs - were stained. High PD-L1 positivity in TCs, especially in SqCCs, indicated that PD-1/PD-L1 targeted therapy may be a promising therapeutic approach.

Transient nature of long-term nonprogression and broad virus-specific proliferative T-cell responses with sustained thymic output in HIV-1 controllers.

Directory of Open Access Journals (Sweden)

Samantha J Westrop

Full Text Available HIV-1(+ individuals who, without therapy, conserve cellular anti-HIV-1 responses, present with high, stable CD4(+ T-cell numbers, and control viral replication, facilitate analysis of atypical viro-immunopathology. In the absence of universal definition, immune function in such HIV controllers remains an indication of non-progression.CD4 T-cell responses to a number of HIV-1 proteins and peptide pools were assessed by IFN-gamma ELISpot and lymphoproliferative assays in HIV controllers and chronic progressors. Thymic output was assessed by sjTRECs levels. Follow-up of 41 HIV-1(+ individuals originally identified as "Long-term non-progressors" in 1996 according to clinical criteria, and longitudinal analysis of two HIV controllers over 22 years, was also performed. HIV controllers exhibited substantial IFN-gamma producing and proliferative HIV-1-specific CD4 T-cell responses to both recombinant proteins and peptide pools of Tat, Rev, Nef, Gag and Env, demonstrating functional processing and presentation. Conversely, HIV-specific T-cell responses were limited to IFN-gamma production in chronic progressors. Additionally, thymic output was approximately 19 fold higher in HIV controllers than in age-matched chronic progressors. Follow-up of 41 HIV-1(+ patients identified as LTNP in 1996 revealed the transitory characteristics of this status. IFN-gamma production and proliferative T-cell function also declines in 2 HIV controllers over 22 years.Although increased thymic output and anti-HIV-1 T-cell responses are observed in HIV controllers compared to chronic progressors, the nature of nonprogressor/controller status appears to be transitory.

Analysis of the expression level and methylation of tumor protein p53, phosphatase and tensin homolog and mutS homolog 2 in N-methyl-N-nitrosourea-induced thymic lymphoma in C57BL/6 mice.

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Huo, Xueyun; Li, Zhenkun; Zhang, Shuangyue; Li, Changlong; Guo, Meng; Lu, Jing; Lv, Jianyi; Du, Xiaoyan; Chen, Zhenwen

2017-10-01

Tumorigenesis is often caused by somatic mutation or epigenetic changes in genes that regulate aspects of cell death, proliferation and survival. Although the functions of multiple tumor suppressor genes have been well studied in isolation, how these genes cooperate during the progression of a single tumor remains unclear in numerous cases. The present study used N-methyl-N-nitrosourea (MNU), one of the most potent mutagenic nitrosourea compounds, to induce thymic lymphoma in C57BL/6J mice. Subsequently, the protein expression levels of phosphatase and tensin homolog (PTEN), transformation protein 53 and mutS homolog 2 (MSH2) were evaluated concomitantly in the thymus, liver, kidney and spleen of MNU-treated mice by western blotting. To determine whether changes in expression level were due to aberrant epigenetic regulation, the present study further examined the methylation status of each gene by MassARRAY analysis. During the tumorigenesis process of an MNU-induced single thymic lymphoma, the expression level of PTEN was revealed to be reduced in thymic lymphoma samples but not in normal or non-tumor thymus tissue samples. Furthermore, a marked reduction of P53 expression levels were demonstrated in thymic lymphomas and spleens with a metastatic tumor. Conversely, MSH2 upregulation was identified only in liver, kidney, and spleen samples that were infiltrated by thymic lymphoma cells. Furthermore, the present study revealed that a number of 5'-C-phosphate-G-3' sites located in the promoter of aberrantly expressed genes had significantly altered methylation statuses. These results improve the understanding of the course of mutagen-induced cancer, and highlight that epigenetic regulation may serve an important function in cancer.

Unicortical critical size defect of rabbit tibia is larger than 8 mm

DEFF Research Database (Denmark)

Aaboe, M; Pinholt, E M; Hjørting-Hansen, E

1994-01-01

The critical-size defect is important as an experimental model to test bone repair materials. Guided tissue regeneration is an established method for tissue regeneration within periodontal surgery. Bony defects covered by a membrane are allowed to be filled by bony tissue. Healing of 8-mm...

Standard Practice for Continuous Sizing and Counting of Airborne Particles in Dust-Controlled Areas and Clean Rooms Using Instruments Capable of Detecting Single Sub-Micrometre and Larger Particles

CERN Document Server

American Society for Testing and Materials. Philadelphia

2007-01-01

1.1 This practice covers the determination of the particle concentration, by number, and the size distribution of airborne particles in dust-controlled areas and clean rooms, for particles in the size range of approximately 0.01 to 5.0 m. Particle concentrations not exceeding 3.5 106 particles/m3 (100 000/ft 3) are covered for all particles equal to and larger than the minimum size measured. 1.2 This practice uses an airborne single particle counting device (SPC) whose operation is based on measuring the signal produced by an individual particle passing through the sensing zone. The signal must be directly or indirectly related to particle size. Note 1The SPC type is not specified here. The SPC can be a conventional optical particle counter (OPC), an aerodynamic particle sizer, a condensation nucleus counter (CNC) operating in conjunction with a diffusion battery or differential mobility analyzer, or any other device capable of counting and sizing single particles in the size range of concern and of sampling...

Container size influences snack food intake independently of portion size.

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Marchiori, David; Corneille, Olivier; Klein, Olivier

2012-06-01

While larger containers have been found to increase food intake, it is unclear whether this effect is driven by container size, portion size, or their combination, as these variables are usually confounded. The study was advertised as examining the effects of snack food consumption on information processing and participants were served M&M's for free consumption in individual cubicles while watching a TV show. Participants were served (1) a medium portion of M&M's in a small (n=30) or (2) in a large container (n=29), or (3) a large portion in a large container (n=29). The larger container increased intake by 129% (199 kcal) despite holding portion size constant, while controlling for different confounding variables. This research suggests that larger containers stimulate food intake over and above their impact on portion size. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nur77 nuclear import and its NBRE-binding activity in thymic lymphoma cells are regulated by different mechanisms sensitive to FK506 or HA1004

International Nuclear Information System (INIS)

Kochel, Izabela; Rapak, Andrzej; Ziolo, Ewa; Strzadala, Leon

2005-01-01

Thymic lymphoma cells restore their sensitivity to ionomycin-induced apoptosis when treated with FK506 or HA1004. In apoptosis-resistant cells, ionomycin-induced Nur77 strongly binds DNA during the first 2 h of response, in contrast to lymphoma cells treated with ionomycin together with FK506 or HA1004, which undergo massive apoptosis. We show that Nur77 could discriminate between calcium signals sensitive to FK506 and those sensitive to HA1004, as the inhibitors differentially regulate the kinetics of Nur77 nuclear import, and FK506, unlike HA1004, inhibits Nur77 DNA-binding activity. In the presence of HA1004, NBRE binding by Nur77 protein increases with time (6 h vs 2 h), whereas the final outcome of both inhibitors is apoptosis of thymic lymphoma cells

Squamate hatchling size and the evolutionary causes of negative offspring size allometry.

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Meiri, S; Feldman, A; Kratochvíl, L

2015-02-01

Although fecundity selection is ubiquitous, in an overwhelming majority of animal lineages, small species produce smaller number of offspring per clutch. In this context, egg, hatchling and neonate sizes are absolutely larger, but smaller relative to adult body size in larger species. The evolutionary causes of this widespread phenomenon are not fully explored. The negative offspring size allometry can result from processes limiting maximal egg/offspring size forcing larger species to produce relatively smaller offspring ('upper limit'), or from a limit on minimal egg/offspring size forcing smaller species to produce relatively larger offspring ('lower limit'). Several reptile lineages have invariant clutch sizes, where females always lay either one or two eggs per clutch. These lineages offer an interesting perspective on the general evolutionary forces driving negative offspring size allometry, because an important selective factor, fecundity selection in a single clutch, is eliminated here. Under the upper limit hypotheses, large offspring should be selected against in lineages with invariant clutch sizes as well, and these lineages should therefore exhibit the same, or shallower, offspring size allometry as lineages with variable clutch size. On the other hand, the lower limit hypotheses would allow lineages with invariant clutch sizes to have steeper offspring size allometries. Using an extensive data set on the hatchling and female sizes of > 1800 species of squamates, we document that negative offspring size allometry is widespread in lizards and snakes with variable clutch sizes and that some lineages with invariant clutch sizes have unusually steep offspring size allometries. These findings suggest that the negative offspring size allometry is driven by a constraint on minimal offspring size, which scales with a negative allometry. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary

Kepler Mission: A Wide-FOV Photometer Designed to Determine the Frequency of Earth-Size and Larger Planets Around Solar-like stars

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Borucki, William; Koch, David; Lissauer, Jack; Basri, Gibor; Caldwell, John; Cochran, William; Dunham, Edward W.; Gilliland, Ronald; Jenkins, Jon M.; Caldwell, Douglas;

Dietary modulation of thymic enzymes.

Science.gov (United States)

Susana, Feliu María; Paula, Perris; Slobodianik, Nora

2014-01-01

Malnutrition is a complex syndrome caused by an inadequate intake of energy, protein, minerals and vitamins which affects the immune system. Nutritional imbalances, present in children with energy-protein malnutrition and infections, make defining the specific effects of each of them on the thymus difficult. For this reason, it is necessary to design an experimental model in animals that could define a single variable. As the thymus atrophy described in humans is similar to that observed in murines, a rat experimental model makes the extrapolation to man possible. Some authors suggest that the activity of Adenosine Deaminase (ADA) and Purine Nucleoside Phosphorylase (PNP)--involved in purine metabolism--have an influence on T lymphocyte development and the immune system, due to intracellular accumulation of toxic levels of deoxynucleotides. Studies in our group, performed in an experimental model on Wistar growing rats, have demonstrated that protein deficiency or imbalance in the profile of essential amino acids in the diet, produce loss of thymus weight, reduction in the number of thymocytes, a diminished proportion of T cells presenting the W3/13 antigenic determinant and DNA content with concomitant increase in cell size, and the proportion of immature T cells and activity of ADA and PNP, without modifying the activity of 5´Nucleotidase in the thymus. It is important to point out that there were neither differences in energy intake between experimental groups and their controls, nor clinical symptoms of deficiency of other nutrients. The increase in these thymic enzyme activities was an alternative mechanism to avoid the accumulation of high levels of deoxynucleotides, which would be toxic for T lymphocytes. On the other hand, the administration of a recovery diet, with a high amount of high quality protein, was able to reverse the mentioned effects. The quick reply of Adenosine Deaminase to nutritional disorders and the following nutritional recovery, points

Comparison between smaller ruptured intracranial aneurysm and larger un-ruptured intracranial aneurysm: gene expression profile analysis.

Science.gov (United States)

Li, Hao; Li, Haowen; Yue, Haiyan; Wang, Wen; Yu, Lanbing; ShuoWang; Cao, Yong; Zhao, Jizong

2017-07-01

As it grows in size, an intracranial aneurysm (IA) is prone to rupture. In this study, we compared two extreme groups of IAs, ruptured IAs (RIAs) smaller than 10 mm and un-ruptured IAs (UIAs) larger than 10 mm, to investigate the genes involved in the facilitation and prevention of IA rupture. The aneurismal walls of 6 smaller saccular RIAs (size smaller than 10 mm), 6 larger saccular UIAs (size larger than 10 mm) and 12 paired control arteries were obtained during surgery. The transcription profiles of these samples were studied by microarray analysis. RT-qPCR was used to confirm the expression of the genes of interest. In addition, functional group analysis of the differentially expressed genes was performed. Between smaller RIAs and larger UIAs, 101 genes and 179 genes were significantly over-expressed, respectively. In addition, functional group analysis demonstrated that the up-regulated genes in smaller RIAs mainly participated in the cellular response to metal ions and inorganic substances, while most of the up-regulated genes in larger UIAs were involved in inflammation and extracellular matrix (ECM) organization. Moreover, compared with control arteries, inflammation was up-regulated and muscle-related biological processes were down-regulated in both smaller RIAs and larger UIAs. The genes involved in the cellular response to metal ions and inorganic substances may facilitate the rupture of IAs. In addition, the healing process, involving inflammation and ECM organization, may protect IAs from rupture.

Influence of age on the proliferation and peripheralization of thymic T cells

International Nuclear Information System (INIS)

Hirokawa, K.; Utsuyama, M.; Katsura, Y.; Sado, T.

1988-01-01

Bone marrow cells obtained from B10.Thy-1.1 mice (H-2b, Thy-1.1) were injected directly into the thymus of C57BL/6 mice (H-2b,Thy 1.2) of various ages. Thymocyte precursors in the injected donor-bone marrow cells could proliferate in the thymic microenvironment in the following manner: first, preferentially proliferating into the subcapsular cortex; and second, spreading to the whole layer of the cortex, a portion of them gradually moving into the medulla. The proliferation of donor-type thymocytes was most pronounced when intrathymic injection of bone marrow cells (ITB) was performed in newborn mice and especially prominent in week-old mice; it took approximately ten weeks for donor-type thymocytes to finish the whole course of proliferation, differentiation, and emigration to the periphery. When ITB was performed in mice 4 weeks of age and older, the proliferation of donor-type thymocytes was retarded at onset, less pronounced in magnitude, and disappeared earlier. Emigration of donor-type T cells from the thymus to the peripheral lymphoid tissues occurred most rapidly when ITB was performed in newborn mice, and these T cells continued to reside thereafter in the peripheral lymphoid tissues. However, when ITB was performed in mice 4 weeks of age and older, the number of emigrated T cells in the spleen decreased (about a tenth of that in newborn mice) and, moreover, these T cells resided only transiently in the spleen. It was suggested that T cells emigrating from the thymus of mice from newborn to 2 weeks of age are long-lived, whereas those from the thymus in mice 4 weeks of age and older are short-lived. However, when 4-week-old young adult mice were treated by irradiation or hydrocortisone, the thymic capacity was enhanced in terms of proliferation and peripheralization of thymocytes, and emigrated T cells became long-lived

Larger men have larger prostates: Detection bias in epidemiologic studies of obesity and prostate cancer risk.

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Rundle, Andrew; Wang, Yun; Sadasivan, Sudha; Chitale, Dhananjay A; Gupta, Nilesh S; Tang, Deliang; Rybicki, Benjamin A

2017-06-01

Obesity is associated with risk of aggressive prostate cancer (PCa), but not with over-all PCa risk. However, obese men have larger prostates which may lower biopsy accuracy and cause a systematic bias toward the null in epidemiologic studies of over-all risk. Within a cohort of 6692 men followed-up after a biopsy or transurethral resection of the prostate (TURP) with benign findings, a nested case-control study was conducted of 495 prostate cancer cases and controls matched on age, race, follow-up duration, biopsy versus TURP, and procedure date. Data on body mass index and prostate volume at the time of the initial procedure were abstracted from medical records. Prior to consideration of differences in prostate volume, overweight (OR = 1.41; 95%CI 1.01, 1.97), and obese status (OR = 1.59; 95%CI 1.09, 2.33) at the time of the original benign biopsy or TURP were associated with PCa incidence during follow-up. Prostate volume did not significantly moderate the association between body-size and PCa, however it did act as an inverse confounder; adjustment for prostate volume increased the effect size for overweight by 22% (adjusted OR = 1.52; 95%CI 1.08, 2.14) and for obese status by 23% (adjusted OR = 1.77; 95%CI 1.20, 2.62). Larger prostate volume at the time of the original benign biopsy or TURP was inversely associated with PCa incidence during follow-up (OR = 0.92 per 10 cc difference in volume; 95%CI 0.88, 0.97). In analyses that stratified case-control pairs by tumor aggressiveness of the case, prostate volume acted as an inverse confounder in analyses of non-aggressive PCa but not in analyses of aggressive PCa. In studies of obesity and PCa, differences in prostate volume cause a bias toward the null, particularly in analyses of non-aggressive PCa. A pervasive underestimation of the association between obesity and overall PCa risk may exist in the literature. © 2017 Wiley Periodicals, Inc.

Selective lymphoid irradiation. V. Synergism with pretransplant thymectomy or thymic irradiation in cardiac transplantation in rats

International Nuclear Information System (INIS)

Iga, C.; Fawwaz, R.; Nowygrod, R.; Reemtsma, K.; Hardy, M.A.

1985-01-01

Selective lymphoid irradiation (SLI) using palladium-109-hematoporphyrin (Pd-H), given four days prior to transplantation, combined with two doses of antilymphocyte globulin (ALG) (10 mg, days -2 and -1), was evaluated as a method of induction of permanent heterotopic cardiac allograft survival in the highly histoincompatible rat strain combination of ACI (RT1(1))-to-Lewis (RT1a). Both Pd-H and ALG localize poorly in the thymus, so this study evaluated whether thymic irradiation (TI) or thymectomy (TX) of the adult recipient results in indefinite allograft survival. Immunosuppression with Pd-H or ALG alone gave a mean survival time (MST) of 6.7 +/- 0.6 days, but the combination of the two agents led to an MST of 17.6 +/- 3.4 days. When TI was combined with Pd-H and ALG, cardiac allograft survival was prolonged to 50.2 +/- 13.9 days, but TI alone showed an MST of 10.3 +/- 1.8 days. Permanent cardiac allograft survival (greater than 250 days) was achieved in all thymectomized recipients treated with the combination of Pd-H and a brief course of ALG. These animals also accepted second-set skin grafts and rejected third-party skin grafts following more than 150 days of ACI cardiac allograft survival. Thymic irradiation, although effective in acting synergistically with SLI and ALG, led to prolonged, but limited allograft survival, although thymectomy with SLI and ALG is synergistic in prolonging allograft survival permanently without chronic immunosuppression

Protecting the larger fish: an ecological, economical and evolutionary analysis using a demographic model

DEFF Research Database (Denmark)

Verdiell, Nuria Calduch

. Recently, there is increasing evidence that this size-selective fishing reduces the chances of maintaining populations at levels sufficient to produce maximum sustainable yields, the chances of recovery/rebuilding populations that have been depleted/collapsed and may causes rapid evolutionary changes...... and the consequent changes in yield. We attempt to evaluate the capability of the larger fish to mitigate the evolutionary change on life-history traits caused by fishing, while also maintaining a sustainable annual yield. This is achieved by calculating the expected selection response on three life-history traits......Many marine fish stocks are reported as overfished on a global scale. This overfishing not only removes fish biomass, but also causes dramatic changes in the age and size structure of fish stocks. In particular, targeting of the larger individuals truncates the age and size structure of stocks...

comparison of clinical features and CT findings between atypical thymoma and thymic carcinoma

International Nuclear Information System (INIS)

Wang Xiangyang; Tan Ye; Chen Juan; Wei Jiahu; Pan Jishun; Du Jun; Zhou Cheng

2011-01-01

Objective: To investigate the differences and the similarities of clinical presentations and CT features between type B3 thymoma (atypical thymoma) and type C thymoma (thymic carcinoma) in the WHO classification of thymic epithelial tumors. Methods: Complete CT findings of thirty cases of type B3 and seventeen cases of type C thymic epithelial tumors confirmed by histopathology according to WHO 2004 Classification System and clinical features including the prognosis of each case were reviewed retrospectively. Statistical analyses of the data for the age and the long diameter were performed with Independent-Samples t test between the two groups. Statistical analysis for gender, association with myasthenia gravis, method of the operation, contours, shapes, calcification,necrosis, enhancement pattern of the tumors on CT, presence of mediastinal lymphadenopathy, invasion of mediastinal fat, chest wall, pericardium, great vessel, pleural mediastinum, metastasis to the plural, pleural effusion, distant metastasis were performed with Fisher exact test. Kaplan-Meier method was employed for survival analysis. Results: Clinical data: the average age of type B3 group was significantly younger (t=-2.905, P=0.006). 90.0% (27/30) of patients in type B3 group were complicated by myasthenia gravis, while only 5.9% (1/17) of patients in type C group were complicated by myasthenia gravis. The difference between the two groups was statistically significant (P=0.000). The ratio of complete resection of type B3 group (80.0%) was significantly higher than that in type C group (P=0.001), 70.6% (12/17) of patients in type C group died within 2 years after surgical resection, while only 20.0% (6/30) of patients in type B3 group died within one to nine years after surgical resection. Three years' survival ratio of C group was 29.4%, and five years' survival ratio of C group was lower than 14.7%, which was significantly lower than B3 group five years' survival ratio was 94.7%), which was

Regulation of radiation-induced protein kinase Cδ activation in radiation-induced apoptosis differs between radiosensitive and radioresistant mouse thymic lymphoma cell lines

International Nuclear Information System (INIS)

Nakajima, Tetsuo; Yukawa, Osami; Tsuji, Hideo; Ohyama, Harumi; Wang, Bing; Tatsumi, Kouichi; Hayata, Isamu; Hama-Inaba, Hiroko

2006-01-01

Protein kinase Cδ (PKCδ) has an important role in radiation-induced apoptosis. The expression and function of PKCδ in radiation-induced apoptosis were assessed in a radiation-sensitive mouse thymic lymphoma cell line, 3SBH5, and its radioresistant variant, XR223. Rottlerin, a PKCδ-specific inhibitor, completely abolished radiation-induced apoptosis in 3SBH5. Radiation-induced PKCδ activation correlated with the degradation of PKCδ, indicating that PKCδ activation through degradation is involved in radiation-induced apoptosis in radiosensitive 3SBH5. In radioresistant XR223, radiation-induced PKCδ activation was lower than that in radiosensitive 3SBH5. Cytosol PKCδ levels in 3SBH5 decreased markedly after irradiation, while those in XR223 did not. There was no apparent change after irradiation in the membrane fractions of either cell type. In addition, basal cytosol PKCδ levels in XR223 were higher than those in 3SBH5. These results suggest that the radioresistance in XR223 to radiation-induced apoptosis is due to a difference in the regulation of radiation-induced PKCδ activation compared to that of 3SBH5. On the other hand, Atm -/- mouse thymic lymphoma cells were more radioresistant to radiation-induced apoptosis than wild-type mouse thymic lymphoma cells. Irradiated wild-type cells, but not Atm -/- cells, had decreased PKCδ levels, indicating that the Atm protein is involved in radiation-induced apoptosis through the induction of PKCδ degradation. The decreased Atm protein levels induced by treatment with Atm small interfering RNA had no effect on radiation-induced apoptosis in 3SBH5 cells. These results suggest that the regulation of radiation-induced PKCδ activation, which is distinct from the Atm-mediated cascade, determines radiation sensitivity in radiosensitive 3SBH5 cells

The petit rat (pet/pet), a new semilethal mutant dwarf rat with thymic and testicular anomalies.

Science.gov (United States)

Chiba, Junko; Suzuki, Katsushi; Suzuki, Hiroetsu

2008-12-01

The petit rat (pet/pet) is a recently discovered semilethal mutant dwarf. The neonatal pet/pet rats had a low body weight and small thymus and testis. During the first 3 d after birth, 50% of the male and 80% of the female pet/pet pups were lost or found dead. Surviving pet/pet rats showed marked retardation of postnatal growth, and their body weights were 41% (female rats) and 32% (male rats) of those of normal rats at the adult stage. The pet/pet rats exhibited proportional dwarfism, and their longitudinal bones were shorter than those of controls without skeletal malformations. Most organs of male pet/pet rats, especially the thymus, testis, adipose tissue surrounding the kidney, and accessory sex organs, weighed markedly less at 140 d of age than did those of their normal counterparts. The thymus of pet/pet rats was small with abnormal thymic follicles. Testes from pet/pet rats exhibited 2 patterns of abnormal histology. Spermatogenesis was present in testes that were only slightly anomalous, but the seminiferous tubules were reduced in diameter. In severely affected testes, most of the seminiferous tubules showed degeneration, and interstitial tissue was increased. Plasma growth hormone concentrations did not differ between pet/pet and normal male rats. The dwarf phenotype of pet/pet rats was inherited as an autosomal recessive trait. These results indicate that the pet/pet rat has a semilethal growth-hormone-independent dwarf phenotype that is accompanied by thymic and testicular anomalies and low birth weight.

Therapeutic implications of thymic uptake of radioiodine in thyroid carcinoma

International Nuclear Information System (INIS)

Wilson, L.M.; Barrington, S.F.; Kettle, A.G.; O'Doherty, M.J.; Coakley, A.J.; Morrison, I.D.

1998-01-01

The management of 38 consecutive patients with differentiated thyroid carcinoma in the period 1991-1996, who each received at least one therapy dose of iodine-131, was reviewed, looking in particular at those in whom anterior mediastinal uptake was demonstrated on scans taken 3 and 7 days post-therapy. Such activity was noted in ten patients. On the basis of clinical follow-up, thyroglobulin measurement and radiological and other scintigraphic imaging, in nine of the ten patients the anterior mediastinal activity was attributed to physiological thymic uptake. Of those nine, all were under 50 years of age; seven were considered disease free, one had residual disease in the neck and one had distant metastases. Physiological uptake by the thymus was more prominent on the 7-day scans and in patients with low tumour volumes. For appropriate patient management it is essential to recognise that physiological uptake of 131 I by the thymus in patients under 50 years of age is a potential cause of false-positive therapy scans. (orig.)

Impaired Thymic Output in Patients with Chronic Hepatitis C Virus Infection

DEFF Research Database (Denmark)

Hartling, Hans Jakob; Gaardbo, Julie Christine; Ronit, Andreas

2013-01-01

Altered T cell homeostasis in chronic hepatitis C virus (HCV) infection has been demonstrated. However, it is unknown if fibrosis is associated with more perturbed T cell homeostasis in chronic HCV infection. The aim of the present study was to examine and compare T cell subsets including recent...... thymic emigrants (RTE), naive, memory, senescent, apoptotic and IL-7 receptor α (CD127) expressing CD4+ and CD8+ T cells as well as telomere length and interferon-γ production in HCV-infected patients with (n=25) and without (n=26) fibrosis as well as in healthy controls (n=24). Decreased proportions...... of CD4+ and CD8+ RTE were found in HCV-infected patients, especially in HCV-infected patients with fibrosis (14.3% (9.7-23.0) and 28.8% (16.1-40.5), respectively) compared to healthy controls (24.2% (16.3-32.1), P=0.004, and 39.1% (31.6-55.0), P=0.010, respectively). Furthermore, HCV-infected patients...

NK cell activite in C157BL/Ka mice during the development of radiation induced thymic lymphomas

International Nuclear Information System (INIS)

Noel, A.; Schaaf-Lafontaine, N.; Defresne, M.P.; Boniver, J.

1985-01-01

Treatment of C57BL/Ka mice with a split dose whole-body irradiation (four weekly irradiations of 1,75 Gy) induces the development of thymic lymphomas. NK activity of spleen cells has been determined at several internals after leukemogenic treatment. Two days after irradiations, NK activity is normal and decreases strongly after one week. This period of decline persists during about one month. Then, NK activity restores and reaches control values. Lymphomas appear in spite of NK activity restauration. The diminution of NK activity during the preleukemic period could favour preleukemic cells apparition [fr

Action video game players and deaf observers have larger Goldmann visual fields.

Science.gov (United States)

Buckley, David; Codina, Charlotte; Bhardwaj, Palvi; Pascalis, Olivier

2010-03-05

We used Goldmann kinetic perimetry to compare how training and congenital auditory deprivation may affect the size of the visual field. We measured the ability of action video game players and deaf observers to detect small moving lights at various locations in the central (around 30 degrees from fixation) and peripheral (around 60 degrees ) visual fields. Experiment 1 found that 10 habitual video game players showed significantly larger central and peripheral field areas than 10 controls. In Experiment 2 we found that 13 congenitally deaf observers had significantly larger visual fields than 13 hearing controls for both the peripheral and central fields. Here the greatest differences were found in the lower parts of the fields. Comparison of the two groups showed that whereas VGP players have a more uniform increase in field size in both central and peripheral fields deaf observers show non-uniform increases with greatest increases in lower parts of the visual field.

Thymic function and T cell parameters in a natural human experimental model of seasonal infectious diseases and nutritional burden

Directory of Open Access Journals (Sweden)

Morgan Gareth

2011-06-01

Full Text Available Abstract Background The study exploits a natural human experimental model of subsistence farmers experiencing chronic and seasonally modified food shortages and infectious burden. Two seasons existed, one of increased deprivation and infections (Jul-Dec, another of abundance and low infections (Jan-Jun; referred to as the hungry/high infection and harvest/low infection seasons respectively. Prior analysis showed a 10-fold excess in infectious disease associated mortality in young adults born in the hungry/high infection versus harvest/low infection season, and reduced thymic output and T cell counts in infancy. Here we report findings on the role of early life stressors as contributors to the onset of T cell immunological defects in later life. Methods We hypothesised that season of birth effects on thymic function and T cell immunity would be detectable in young adults since Kaplan-Meier survival curves indicated this to be the time of greatest mortality divergence. T cell subset analyses by flow-cytometry, sjTRECs, TCRVβ repertoire and telomere length by PCR, were performed on samples from 60 males (18-23 y selected to represent births in the hungry/high infection and harvest/low infection Results Total lymphocyte counts were normal and did not differ by birth season. CD3+ and CD4+ but not CD8+ counts were lower for those born during the hungry/high infection season. CD8+ telomere length also tended to be shorter. Overall, CD8+ TCRVβ repertoire skewing was observed with 'public' expressions and deletions seen in TCRVβ12/22 and TCRVβ24, respectively but no apparent effect of birth season. Conclusions We conclude that, although thymic function was unchanged, the CD4+ and CD3+ counts, and CD8+ telomere length results suggested that aspects of adult T cell immunity were under the influence of early life stressors. The endemicity of CMV and HBV suggested that chronic infections may modulate immunity through T cell repertoire development. The

Larger groups of passerines are more efficient problem solvers in the wild

Science.gov (United States)

Morand-Ferron, Julie; Quinn, John L.

2011-01-01

Group living commonly helps organisms face challenging environmental conditions. Although a known phenomenon in humans, recent findings suggest that a benefit of group living in animals generally might be increased innovative problem-solving efficiency. This benefit has never been demonstrated in a natural context, however, and the mechanisms underlying improved efficiency are largely unknown. We examined the problem-solving performance of great and blue tits at automated devices and found that efficiency increased with flock size. This relationship held when restricting the analysis to naive individuals, demonstrating that larger groups increased innovation efficiency. In addition to this effect of naive flock size, the presence of at least one experienced bird increased the frequency of solving, and larger flocks were more likely to contain experienced birds. These findings provide empirical evidence for the “pool of competence” hypothesis in nonhuman animals. The probability of success also differed consistently between individuals, a necessary condition for the pool of competence hypothesis. Solvers had a higher probability of success when foraging with a larger number of companions and when using devices located near rather than further from protective tree cover, suggesting a role for reduced predation risk on problem-solving efficiency. In contrast to traditional group living theory, individuals joining larger flocks benefited from a higher seed intake, suggesting that group living facilitated exploitation of a novel food source through improved problem-solving efficiency. Together our results suggest that both ecological and social factors, through reduced predation risk and increased pool of competence, mediate innovation in natural populations. PMID:21930936

Larger eggs in resident brown trout living in sympatry with anadromous brown trout

DEFF Research Database (Denmark)

Olofsson, H.; Mosegaard, Henrik

1999-01-01

Freshwater resident brown trout (Salmo trutta L.) in the stream Jorlandaan (southwestern Sweden) had larger eggs (range of actual mean egg wet weights, 65.9-108.5 mg) than both sympatric migratory trout (76.8-84.2 mg) and trout from five other Swedish streams with allopatric resident (23.7-80.1 mg......) or migratory populations (44.5-121.9 mg), after accounting for differences in body size. In Jorlandaan, some resident females even had a larger absolute mean egg weight than any of the migratory females found in the stream Resident trout had low absolute fecundity, and our data suggest that resident females...... in Jorlandan produce large eggs at the expense of their fecundity The extremely large relative egg size in resident Jorlandaan females suggests that the production of large offspring enhances fitness, possibly through increased fry survival....

The relations between forest fragmentation and bird community body size and biodiversity and bird community body size.

OpenAIRE

Hopman, F.

2017-01-01

Bachelor thesis Future Planet Studies, major biologie ABSTRACT Animal species with a larger body-size tend to have larger home ranges than small-bodied animals. Therefore it is likely that they are more affected by habitat fragmentation than small-bodied species. Body size of birds also seems to have a negative relation with species richness. This research has therefore looked into whether birds with a larger body-size are more sensitive to habitat fragmentation caused by forest...

Unique loss of heterozygosity of murine thymic lymphomas as a candidate of radiation signature

Energy Technology Data Exchange (ETDEWEB)

Shimada, Yoshiya; Nishimura, Mayumi; Kakinuma, Shizuko [National Inst. of Radiological Sciences, Chiba (Japan); Wakana, Shigeharu; Okumoto, Masaaki

1999-06-01

Signature(s) of prior exposure to carcinogens have immediate application to the identification of environmental risk factors. Such signatures have been sought to aid in developing policies for the protection from risks of environmental carcinogens. Although ionizing radiation is a potent carcinogenic agent, little is known about possible radiation signatures. This is because radiation induces a broad spectrum of DNA lesions. Here we describe a diversity of K-ras mutations and a unique locus with frequent loss of heterozygisity (LOH) on chromosome 11 of radiation induced thymic lymphomas. The latter locus has never been observed to be similarly altered in either ethylnitrosourea-induced or spontaneously developed lymphomas. These results describe, to our knowledge for the first time, a molecular basis for radiation signature. (author)

IL-4/IL-13 Signaling Inhibits the Potential of Early Thymic Progenitors To Commit to the T Cell Lineage.

Science.gov (United States)

Barik, Subhasis; Miller, Mindy M; Cattin-Roy, Alexis N; Ukah, Tobechukwu K; Chen, Weirong; Zaghouani, Habib

2017-10-15

Early thymic progenitors (ETPs) are endowed with diverse potencies and can give rise to myeloid and lymphoid lineage progenitors. How the thymic environment guides ETP commitment and maturation toward a specific lineage remains obscure. We have previously shown that ETPs expressing the heteroreceptor (HR) comprising IL-4Rα and IL-13Rα1 give rise to myeloid cells but not T cells. In this article, we show that signaling through the HR inhibits ETP maturation to the T cell lineage but enacts commitment toward the myeloid cells. Indeed, HR + ETPs, but not HR - ETPs, exhibit activated STAT6 transcription factor, which parallels with downregulation of Notch1, a critical factor for T cell development. Meanwhile, the myeloid-specific transcription factor C/EBPα, usually under the control of Notch1, is upregulated. Furthermore, in vivo inhibition of STAT6 phosphorylation restores Notch1 expression in HR + ETPs, which regain T lineage potential. In addition, upon stimulation with IL-4 or IL-13, HR - ETPs expressing virally transduced HR also exhibit STAT6 phosphorylation and downregulation of Notch1, leading to inhibition of lymphoid, but not myeloid, lineage potential. These observations indicate that environmental cytokines play a role in conditioning ETP lineage choice, which would impact T cell development. Copyright © 2017 by The American Association of Immunologists, Inc.

Activation of the aryl hydrocarbon receptor reduces the number of precursor and effector T cells, but preserves thymic CD4(+)CD25(+)Foxp3(+) regulatory T cells

NARCIS (Netherlands)

Schulz, V.J.; Smit, J.J.; Bol-Schoenmakers, M.; van Duursen, M.B.M.; van den Berg, M.; Pieters, R.H.H.

2012-01-01

Aryl hydrocarbon receptor (AhR) activation suppresses immune responses, including allergic sensitization, by increasing the percentage of regulatory (Treg) cells. Furthermore, AhR activation is known to affect thymic precursor T cells. However, the effect of AhR activation on intrathymic

Origins and Properties of Dental, Thymic, and Bone Marrow Mesenchymal Cells and Their Stem Cells

Science.gov (United States)

Komada, Yukiya; Yamane, Toshiyuki; Kadota, Daiji; Isono, Kana; Takakura, Nobuyuki; Hayashi, Shin-Ichi; Yamazaki, Hidetoshi

2012-01-01

Mesenchymal cells arise from the neural crest (NC) or mesoderm. However, it is difficult to distinguish NC-derived cells from mesoderm-derived cells. Using double-transgenic mouse systems encoding P0-Cre, Wnt1-Cre, Mesp1-Cre, and Rosa26EYFP, which enabled us to trace NC-derived or mesoderm-derived cells as YFP-expressing cells, we demonstrated for the first time that both NC-derived (P0- or Wnt1-labeled) and mesoderm-derived (Mesp1-labeled) cells contribute to the development of dental, thymic, and bone marrow (BM) mesenchyme from the fetal stage to the adult stage. Irrespective of the tissues involved, NC-derived and mesoderm-derived cells contributed mainly to perivascular cells and endothelial cells, respectively. Dental and thymic mesenchyme were composed of either NC-derived or mesoderm-derived cells, whereas half of the BM mesenchyme was composed of cells that were not derived from the NC or mesoderm. However, a colony-forming unit-fibroblast (CFU-F) assay indicated that CFU-Fs in the dental pulp, thymus, and BM were composed of NC-derived and mesoderm-derived cells. Secondary CFU-F assays were used to estimate the self-renewal potential, which showed that CFU-Fs in the teeth, thymus, and BM were entirely NC-derived cells, entirely mesoderm-derived cells, and mostly NC-derived cells, respectively. Colony formation was inhibited drastically by the addition of anti-platelet–derived growth factor receptor-β antibody, regardless of the tissue and its origin. Furthermore, dental mesenchyme expressed genes encoding critical hematopoietic factors, such as interleukin-7, stem cell factor, and cysteine-X-cysteine (CXC) chemokine ligand 12, which supports the differentiation of B lymphocytes and osteoclasts. Therefore, the mesenchymal stem cells found in these tissues had different origins, but similar properties in each organ. PMID:23185234

Dust captures effectiveness of scrubber systems on mechanical miners operating in larger roadways.

CSIR Research Space (South Africa)

Hole, BJ

1998-03-01

Full Text Available The project was directed towards bord and pillar working by mechanised miners operating in larger section roadways, where the problem of scrubber capture tends to be greatest owing to the limited size of the zone of influence around exhaust...

Mediastinal neoplasms in patients with Graves disease: a possible link between sustained hyperthyroidism and thymic neoplasia?

Directory of Open Access Journals (Sweden)

Boyd Jonathan D

2012-07-01

Full Text Available Abstract Background Anterior mediastinal masses are a rare but well documented finding in Graves disease. The vast majority of these lesions represents benign thymic hypertrophy and regress after treatment of the hyperthyroidism. A small percentage of these cases however represent neoplastic/malignant diseases which require further treatment. Cases 12 year old boy with one year history of refractory Graves disease was found to have an anterior mediastinal mass and underwent curative thyroidectomy for sustained hyperthyroidism. Cervical lymphadenopathy was detected during the procedure and biopsy was obtained. A 23 year old woman who presented with a one month history of hyperthyroid symptoms, was diagnosed with Graves disease and also was found to have an anterior mediastinal mass on imaging. Biopsy of the anterior mediastinal mass was obtained and subsequently the patient underwent robotic thymectomy. Histologic examination and immunophenotyping of the cervical lymph node in a 12 year old boy revealed neoplastic proliferation of T lymphoblasts diagnostic of T lymphoblastic leukemia/lymphoma. Examination of the anterior mediastinal mass biopsy in the 23 year old woman revealed type B1 thymoma which was confirmed after examination of the subsequent robotic thymectomy specimen. Conclusion This is the first reported case of T cell lymphoblastic lymphoma and the third reported case of thymoma associated with sustained hyperthyroidism due to Graves disease. These cases indicate that an anterior mediastinal mass in a patient with active Graves disease may be due to a neoplastic cause, which may require definitive treatment. Caution should be exercised when dismissing a mediastinal mass as benign thymic hyperplasia in patients with active Graves disease.

Differential regulation of caspase-9 by ionizing radiation- and UV-induced apoptotic pathways in thymic cells

Energy Technology Data Exchange (ETDEWEB)

Okamoto, Mayumi; Koga, Satomi [Department of Life Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Hiroshima 727-0023 (Japan); Tatsuka, Masaaki, E-mail: tatsuka@pu-hiroshima.ac.jp [Department of Life Sciences, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Hiroshima 727-0023 (Japan)

2010-06-01

In mouse thymic lymphoma 3SB cells bearing wild type p53, ionizing radiation (IR) and UV light are potent triggers of caspase-3-dependent apoptosis. Although cytochrome c was released from mitochondria as expected, caspase-9 activation was not observed in UV-exposed cells. Laser scanning confocal microscopy analysis showed that caspase-9 is localized in an unusual punctuated pattern in UV-induced apoptotic cells. In agreement with differences in the status of caspase-9 activation between IR and UV, subcellular protein fractionation experiments showed that pro-apoptotic apoptosis protease-activating factor 1 (Apaf-1), normally a part of the apoptosome assembled in response to the release of cytochrome c from mitochondria, and B-cell lymphoma extra long (Bcl-xL), an inhibitor of the change in mitochondrial membrane permeability, were redistributed by the IR-exposure but not by the UV-exposure. Instead of the sequestration of the capase-9/apoptosome activation in UV-induced apoptotic cells, the extrinsic apoptotic signaling generated by caspase-8 activation and consequent activation of B-cell lymphoma extra long (Bid) to release cytochrome c from mitochondria was observed. Thus, the post-mitochondrial apoptotic pathway downstream of cytochrome c release cannot operate the apoptosome function in UV-induced apoptosis in thymic 3SB cells. The intracellular redistribution and sequestration of apoptosis-related proteins upon mitochondrion-based apoptotic signaling was identified as a novel cellular mechanism to respond to DNA damage in an agent type-specific manner. This finding suggests that the kind of the critical ultimate apoptosis-inducing DNA lesion complex form resulting from the agent-specific DNA damage responses is important to determine which of apoptosis signals would be activated.

Portion size and intended consumption. Evidence for a pre-consumption portion size effect in males?

Science.gov (United States)

Robinson, Eric; te Raa, Wesselien; Hardman, Charlotte A

2015-08-01

Larger portions increase energy intake (the 'portion size effect'); however, the mechanisms behind this effect are unclear. Although pre-meal intentions are thought to be an important determinant of energy intake, little research has examined how much of a meal individuals intend to eat when served standard versus larger portion sizes. Three studies examined the effect of manipulating portion size on intended food consumption. In Studies 1 (spaghetti bolognese) and 2 (curry and rice) male participants were shown an image of either a standard or a larger meal and indicated how much of the meal they intended to consume. In Study 3 male and female participants were served either a standard or a larger portion of ice cream for dessert, they indicated how much they intended to consume and then ate as much of the ice cream as they desired. Regardless of being shown standard or large portion sizes, in Studies 1 and 2 participants reported that they intended to eat the majority of the meal, equating to a large difference in intended energy consumption between portion size conditions (a 'pre-consumption portion size effect'). This finding was replicated in male participants in Study 3, although females intended to eat a smaller proportion of the larger portion of ice cream, compared to the standard portion. Both male and female participants tended to eat in accordance with their pre-meal intentions and a portion size effect on actual consumption was subsequently observed in males, but not in females. The portion size effect may be observed when measuring pre-meal intended consumption in males. Copyright © 2015. Published by Elsevier Ltd.

Glenosphere size in reverse shoulder arthroplasty: is larger better for external rotation and abduction strength?

Science.gov (United States)

Müller, Andreas M; Born, Marian; Jung, Christian; Flury, Matthias; Kolling, Christoph; Schwyzer, Hans-Kaspar; Audigé, Laurent

2018-01-01

The role of glenosphere size in reverse shoulder arthroplasty (RSA) may be important in prosthetic stability, joint kinematics, rotator cuff tension and excursion, scapular impingement, humeral lateralization, deltoid wrap, and the occurrence of "notching." This study compared short- and midterm clinical and radiographic outcomes for 2 different glenosphere sizes of a single RSA type with respect to implant positioning, glenoid size, and morphology. This retrospective analysis included 68 RSA procedures that were prospectively documented in a local register during a 5-year postoperative period. Two glenosphere diameter sizes of 36 mm (n = 33) and 44 mm (n = 35) were used. Standard radiographs were made preoperatively (ie, baseline) and at 6, 12, 24, and 60 months after surgery. Range of motion, strength, the Constant-Murley score, and the Shoulder Pain and Disability Index were also assessed at all follow-up visits. The effect of glenosphere size on measured outcomes was adjusted for baseline values, patient gender, and humeral head diameter. No significant differences were found in the functional scores between treatment groups at all follow-up assessments. At the 12-month follow-up, patients with a 44-mm glenosphere had greater external rotation in adduction (mean difference, 12°; P = .001) and abduction strength (mean difference, 1.4 kg; P = .026) compared with those with the smaller implant. These differences remained at 60 months. Scapular notching was observed in 38% of all patients, without any relevant difference between the groups. An increase in glenosphere diameter leads to a clinically moderate but significant increase in external rotation in adduction and abduction strength at midterm follow-up. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Signal transduction around thymic stromal lymphopoietin (TSLP in atopic asthma

Directory of Open Access Journals (Sweden)

Kuepper Michael

2008-08-01

Full Text Available Abstract Thymic stromal lymphopoietin (TSLP, a novel interleukin-7-like cytokine, triggers dendritic cell-mediated inflammatory responses ultimately executed by T helper cells of the Th2 subtype. TSLP emerged as a central player in the development of allergic symptoms, especially in the airways, and is a prime regulatory cytokine at the interface of virus- or antigen-exposed epithelial cells and dendritic cells (DCs. DCs activated by epithelium-derived TSLP can promote naïve CD4+ T cells to adopt a Th2 phenotype, which in turn recruite eosinophilic and basophilic granulocytes as well as mast cells into the airway mucosa. These different cells secrete inflammatory cytokines and chemokines operative in inducing an allergic inflammation and atopic asthma. TSLP is, thus, involved in the control of both an innate and an adaptive immune response. Since TSLP links contact of allergen with the airway epithelium to the onset and maintainance of the asthmatic syndrome, defining the signal transduction underlying TSLP expression and function is of profound interest for a better understandimg of the disease and for the development of new therapeutics.

Normal thymus in adults: appearance on CT and associations with age, sex, BMI and smoking

International Nuclear Information System (INIS)

Araki, Tetsuro; Nishino, Mizuki; Hatabu, Hiroto; Gao, Wei; Dupuis, Josee; Hunninghake, Gary M.; Washko, George R.; Murakami, Takamichi; O'Connor, George T.

2016-01-01

To investigate CT appearance and size of the thymus in association with participant characteristics. 2540 supposedly healthy participants (mean age 58.9 years, 51 % female) were evaluated for the CT appearance of thymic glands with four-point scores (according to the ratio of fat and soft tissue), size and morphology. These were correlated with participants' age, sex, BMI and smoking history. Of 2540 participants, 1869 (74 %) showed complete fatty replacement of the thymus (Score 0), 463 (18 %) predominantly fatty attenuation (Score 1), 172 (7 %) half fatty and half soft-tissue attenuation (Score 2) and 36 (1 %) solid thymic gland with predominantly soft-tissue attenuation (Score 3). Female participants showed less fatty degeneration of the thymus with higher thymic scores within age 40-69 years (P < 0.001). Participants with lower thymic scores showed higher BMI (P < 0.001) and were more likely to be former smokers (P < 0.001) with higher pack-years (P = 0.04). Visual assessment with four-point thymic scores revealed a sex difference in the fatty degeneration of the thymus with age. Women show significantly higher thymic scores, suggesting less fat content of the thymus, during age 40-69 years. Cigarette smoking and high BMI are associated with advanced fatty replacement of the thymus. (orig.)

Normal thymus in adults: appearance on CT and associations with age, sex, BMI and smoking

Energy Technology Data Exchange (ETDEWEB)

Araki, Tetsuro [Harvard Medical School, Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women' s Hospital, Boston, MA (United States); Kinki University Faculty of Medicine, Department of Radiology, Osaka-Sayama (Japan); Nishino, Mizuki; Hatabu, Hiroto [Harvard Medical School, Department of Radiology, Center for Pulmonary Functional Imaging, Brigham and Women' s Hospital, Boston, MA (United States); Gao, Wei [Boston University School of Public Health, Department of Biostatistics, Boston, MA (United States); Dupuis, Josee [Boston University School of Public Health, Department of Biostatistics, Boston, MA (United States); The National Heart Lung and Blood Institute' s Framingham Heart Study, Framingham, MA (United States); Hunninghake, Gary M.; Washko, George R. [Harvard Medical School, The Pulmonary and Critical Care Division, Brigham and Women' s Hospital, Boston, MA (United States); Murakami, Takamichi [Kinki University Faculty of Medicine, Department of Radiology, Osaka-Sayama (Japan); O' Connor, George T. [The National Heart Lung and Blood Institute' s Framingham Heart Study, Framingham, MA (United States); Boston University School of Medicine, Pulmonary Center and Department of Medicine, Boston, MA (United States)

2016-01-15

To investigate CT appearance and size of the thymus in association with participant characteristics. 2540 supposedly healthy participants (mean age 58.9 years, 51 % female) were evaluated for the CT appearance of thymic glands with four-point scores (according to the ratio of fat and soft tissue), size and morphology. These were correlated with participants' age, sex, BMI and smoking history. Of 2540 participants, 1869 (74 %) showed complete fatty replacement of the thymus (Score 0), 463 (18 %) predominantly fatty attenuation (Score 1), 172 (7 %) half fatty and half soft-tissue attenuation (Score 2) and 36 (1 %) solid thymic gland with predominantly soft-tissue attenuation (Score 3). Female participants showed less fatty degeneration of the thymus with higher thymic scores within age 40-69 years (P < 0.001). Participants with lower thymic scores showed higher BMI (P < 0.001) and were more likely to be former smokers (P < 0.001) with higher pack-years (P = 0.04). Visual assessment with four-point thymic scores revealed a sex difference in the fatty degeneration of the thymus with age. Women show significantly higher thymic scores, suggesting less fat content of the thymus, during age 40-69 years. Cigarette smoking and high BMI are associated with advanced fatty replacement of the thymus. (orig.)

Larger aftershocks happen farther away: nonseparability of magnitude and spatial distributions of aftershocks

Science.gov (United States)

Van Der Elst, Nicholas; Shaw, Bruce E.

2015-01-01

Aftershocks may be driven by stress concentrations left by the main shock rupture or by elastic stress transfer to adjacent fault sections or strands. Aftershocks that occur within the initial rupture may be limited in size, because the scale of the stress concentrations should be smaller than the primary rupture itself. On the other hand, aftershocks that occur on adjacent fault segments outside the primary rupture may have no such size limitation. Here we use high-precision double-difference relocated earthquake catalogs to demonstrate that larger aftershocks occur farther away than smaller aftershocks, when measured from the centroid of early aftershock activity—a proxy for the initial rupture. Aftershocks as large as or larger than the initiating event nucleate almost exclusively in the outer regions of the aftershock zone. This observation is interpreted as a signature of elastic rebound in the earthquake catalog and can be used to improve forecasting of large aftershocks.

Appearance of thymic nurse cells after gamma irradiation

International Nuclear Information System (INIS)

Mulder, A.H.; Bekkum, D.W. van

1983-01-01

Since prothymocytes home from the bone marrow to the thymus, it was tested in the mouse whether prothymocytes could be recaptured from thymic nurse cells (TNC). Bone marrow cells were labelled with the red fluorescing anthracycline daunomycin and varying numbers (up to 25 x 10 6 nucleated bone marrow cells) were injected into lethally irradiated recipients. At several time intervals after transplantation (up to 24 hours), thymuses were removed and the TNCs were isolated. No specific red fluorescence was found within the TNCs. These experiments were repeated with supravital compounds at concentrations which have been shown not to affect viability, homing pattern and function. Again, no specific fluoresence was found in the TNC after transplantation of labelled bone marrow into irradiated mice. The relationship between the dose of total body gamma irradiation and the time after irradiation was investigated. Maximal numbers of TNCs were found at 6 hours after irradiation with 4 Gy. Eight to 12 hours after irradiation, the number of TNCs isolated decreased and had returned to preirradiation levels at 24 hours. The relation between TBI dose and the number of TNCs per thymus is shown. The number determined at 3 hours increased with the dose to reach a maximum at 4 Gy. The authors later studied the morphology of the TNCs isolated at 4 to 6 hours after irradiation. On electron microscopic examination, signs of degeneration and death of the enclosed thymocytes was detected. (Auth.)

More 'altruistic' punishment in larger societies.

Science.gov (United States)

Marlowe, Frank W; Berbesque, J Colette

2008-03-07

If individuals will cooperate with cooperators, and punish non-cooperators even at a cost to themselves, then this strong reciprocity could minimize the cheating that undermines cooperation. Based upon numerous economic experiments, some have proposed that human cooperation is explained by strong reciprocity and norm enforcement. Second-party punishment is when you punish someone who defected on you; third-party punishment is when you punish someone who defected on someone else. Third-party punishment is an effective way to enforce the norms of strong reciprocity and promote cooperation. Here we present new results that expand on a previous report from a large cross-cultural project. This project has already shown that there is considerable cross-cultural variation in punishment and cooperation. Here we test the hypothesis that population size (and complexity) predicts the level of third-party punishment. Our results show that people in larger, more complex societies engage in significantly more third-party punishment than people in small-scale societies.

Oocyte size, egg index, and body lipid content in relation to body size in the solitary bee Megachile rotundata.

Science.gov (United States)

O'Neill, Kevin M; Delphia, Casey M; O'Neill, Ruth P

2014-01-01

Females of solitary, nest-provisioning bees have relatively low fecundity, but produce large eggs as part of their overall strategy of investing substantially in each offspring. In intraspecific comparisons of several species of solitary, nest-provisioning bees and wasps, the size of the mature eggs produced increases with female body size. We further examined oocyte size-body size correlations in the solitary bee Megachile rotundata (F.), an important crop pollinator. We hypothesized that larger females carry larger basal oocytes (i.e., those next in line to be oviposited) but that body size-oocyte size correlations would be absent soon after emergence, before their first eggs fully matured. Because egg production is likely affected by the quantity of stored lipids carried over from the bees' immature stages, we also tested the hypothesis that female body size is correlated with the body lipid content at adult emergence, the time during which oocyte growth accelerates. We found significant correlations of body size with oocyte size variables chosen to reflect: (1) the magnitude of the investment in the next egg to be laid (i.e., the length and volume of the basal oocyte) and (2) the longer term potential to produce mature oocytes (i.e., the summed lengths and volumes of the three largest oocytes in each female). Positive correlations existed throughout the nesting season, even during the first week following adult emergence. The ability to produce and carry larger oocytes may be linked to larger females starting the nesting season with greater lipid stores (which we document here) or to greater space within the abdomen of larger females. Compared to other species of solitary bees, M. rotundata appears to have (1) smaller oocytes than solitary nest-provisioning bees in general, (2) comparable oocyte sizes relative to congeners, and (3) larger oocytes than related brood parasitic megachilids.

Base stock policies with degraded service to larger orders

DEFF Research Database (Denmark)

Du, Bisheng; Larsen, Christian

We study an inventory system controlled by a base stock policy assuming a compound renewal demand process. We extend the base stock policy by incorporating rules for degrading the service of larger orders. Two specific rules are considered, denoted Postpone(q,t) and Split(q), respectively. The aim...... of using these rules is to achieve a given order fill rate of the regular orders (those of size less than or equal to the parameter q) having less inventory. We develop mathematical expressions for the performance measures order fill rate (of the regular orders) and average on-hand inventory level. Based...

A specialist toxicity database (TRACE) is more effective than its larger, commercially available counterparts

NARCIS (Netherlands)

Anderson, C.A.; Copestake, P.T.; Robinson, L.

2000-01-01

The retrieval precision and recall of a specialist bibliographic toxicity database (TRACE) and a range of widely available bibliographic databases used to identify toxicity papers were compared. The analysis indicated that the larger size and resources of the major bibliographic databases did not,

Portion size: a qualitative study of consumers' attitudes toward point-of-purchase interventions aimed at portion size.

Science.gov (United States)

Vermeer, Willemijn M; Steenhuis, Ingrid H M; Seidell, Jacob C

2010-02-01

This qualitative study assessed consumers' opinions of food portion sizes and their attitudes toward portion-size interventions located in various point-of-purchase settings targeting overweight and obese people. Eight semi-structured focus group discussions were conducted with 49 participants. Constructs from the diffusion of innovations theory were included in the interview guide. Each focus group was recorded and transcribed verbatim. Data were coded and analyzed with Atlas.ti 5.2 using the framework approach. Results showed that many participants thought that portion sizes of various products have increased during the past decades and are larger than acceptable. The majority also indicated that value for money is important when purchasing and that large portion sizes offer more value for money than small portion sizes. Furthermore, many experienced difficulties with self-regulating the consumption of large portion sizes. Among the portion-size interventions that were discussed, participants had most positive attitudes toward a larger availability of portion sizes and pricing strategies, followed by serving-size labeling. In general, reducing package serving sizes as an intervention strategy to control food intake met resistance. The study concludes that consumers consider interventions consisting of a larger variety of available portion sizes, pricing strategies and serving-size labeling as most acceptable to implement.

Computer tomographic examination of the thymus

International Nuclear Information System (INIS)

Weiss, C.; Dinkel, E.; Wimmer, B.; Grosser, G.; Schildge, J.

1987-01-01

The diagnostic value of CT in follicular thymic hyperplasia and in thymomas in 8 patients with myasthenia gravis and in 12 patients without myasthenia gravis suffering from thymic tumors was evaluated by correlating CT-findings to surgical results and pathological-histological findings. Thymic size of the six patients with histologically proven follicular hyperplasia were scattered within the normal range, but half of them were at the upper limit. Thymic tumors were differentiated between invasive and non invasive tumors by CT staging. Solid tumors with different histology could not be further classified; the attenuation values ranging from 15-55 HU were the same in tumors, follicular hyperplasia and normal thymus. (orig.) [de

Computer tomographic examination of the thymus. Normal and pathological findings

Energy Technology Data Exchange (ETDEWEB)

Weiss, C.; Dinkel, E.; Wimmer, B.; Grosser, G.; Schildge, J.

1987-09-01

The diagnostic value of CT in follicular thymic hyperplasia and in thymomas in 8 patients with myasthenia gravis and in 12 patients without myasthenia gravis suffering from thymic tumors was evaluated by correlating CT-findings to surgical results and pathological-histological findings. Thymic size of the six patients with histologically proven follicular hyperplasia were scattered within the normal range, but half of them were at the upper limit. Thymic tumors were differentiated between invasive and non invasive tumors by CT staging. Solid tumors with different histology could not be further classified; the attenuation values ranging from 15-55 HU were the same in tumors, follicular hyperplasia and normal thymus.

Poverty and household size

NARCIS (Netherlands)

Lanjouw, P.; Ravallion, M.

1995-01-01

The widely held view that larger families tend to be poorer in developing countries has influenced research and policy. The scope for size economies in consumption cautions against this view. The authors find that the correlation between poverty and size vanishes in Pakistan when the size elasticity

BODY SIZE AND HAREM SIZE IN MALE RED-WINGED BLACKBIRDS: MANIPULATING SELECTION WITH SEX-SPECIFIC FEEDERS.

Science.gov (United States)

Rohwer, Sievert; Langston, Nancy; Gori, Dave

1996-10-01

We experimentally manipulated the strength of selection in the field on red-winged blackbirds (Agelaius phoeniceus) to test hypotheses about contrasting selective forces that favor either large or small males in sexually size dimorphic birds. Selander (1972) argued that sexual selection favors larger males, while survival selection eventually stabilizes male size because larger males do not survive as well as smaller males during harsh winters. Searcy (1979a) proposed instead that sexual selection may be self limiting: male size might be stabilized not by overwinter mortality, but by breeding-season sexual selection that favors smaller males. Under conditions of energetic stress, smaller males should be able to display more and thus achieve higher reproductive success. Using feeders that provisioned males or females but not both, we produced conditions that mimicked the extremes of natural conditions. We found experimental support for the hypothesis that when food is abundant, sexual selection favors larger males. But even under conditions of severe energetic stress, smaller males did not gain larger harems, as the self-limiting hypothesis predicted. Larger males were more energetically stressed than smaller males, but in ways that affected their future reproductive output rather than their current reproductive performance. Stressed males that returned had smaller wings and tails than those that did not return; among returning stressed males, relative harem sizes were inversely related to wing and tail length. Thus, male body size may be stabilized not by survival costs during the non-breeding season, nor by energetic costs during the breeding season, but by costs of future reproduction that larger males pay for their increased breeding-season effort. © 1996 The Society for the Study of Evolution.

Oocyte size, egg index, and body lipid content in relation to body size in the solitary bee Megachile rotundata

Directory of Open Access Journals (Sweden)

Kevin M. O’Neill

2014-03-01

Full Text Available Females of solitary, nest-provisioning bees have relatively low fecundity, but produce large eggs as part of their overall strategy of investing substantially in each offspring. In intraspecific comparisons of several species of solitary, nest-provisioning bees and wasps, the size of the mature eggs produced increases with female body size. We further examined oocyte size–body size correlations in the solitary bee Megachile rotundata (F., an important crop pollinator. We hypothesized that larger females carry larger basal oocytes (i.e., those next in line to be oviposited but that body size–oocyte size correlations would be absent soon after emergence, before their first eggs fully matured. Because egg production is likely affected by the quantity of stored lipids carried over from the bees’ immature stages, we also tested the hypothesis that female body size is correlated with the body lipid content at adult emergence, the time during which oocyte growth accelerates. We found significant correlations of body size with oocyte size variables chosen to reflect: (1 the magnitude of the investment in the next egg to be laid (i.e., the length and volume of the basal oocyte and (2 the longer term potential to produce mature oocytes (i.e., the summed lengths and volumes of the three largest oocytes in each female. Positive correlations existed throughout the nesting season, even during the first week following adult emergence. The ability to produce and carry larger oocytes may be linked to larger females starting the nesting season with greater lipid stores (which we document here or to greater space within the abdomen of larger females. Compared to other species of solitary bees, M. rotundata appears to have (1 smaller oocytes than solitary nest-provisioning bees in general, (2 comparable oocyte sizes relative to congeners, and (3 larger oocytes than related brood parasitic megachilids.

Pre-T Cell Receptors (Pre-TCRs) Leverage Vβ Complementarity Determining Regions (CDRs) and Hydrophobic Patch in Mechanosensing Thymic Self-ligands.

Science.gov (United States)

Das, Dibyendu Kumar; Mallis, Robert J; Duke-Cohan, Jonathan S; Hussey, Rebecca E; Tetteh, Paul W; Hilton, Mark; Wagner, Gerhard; Lang, Matthew J; Reinherz, Ellis L

2016-12-02

The pre-T cell receptor (pre-TCR) is a pTα-β heterodimer functioning in early αβ T cell development. Although once thought to be ligand-autonomous, recent studies show that pre-TCRs participate in thymic repertoire formation through recognition of peptides bound to major histocompatibility molecules (pMHC). Using optical tweezers, we probe pre-TCR bonding with pMHC at the single molecule level. Like the αβTCR, the pre-TCR is a mechanosensor undergoing force-based structural transitions that dynamically enhance bond lifetimes and exploiting allosteric control regulated via the Cβ FG loop region. The pre-TCR structural transitions exhibit greater reversibility than TCRαβ and ordered force-bond lifetime curves. Higher piconewton force requires binding through both complementarity determining region loops and hydrophobic Vβ patch apposition. This patch functions in the pre-TCR as a surrogate Vα domain, fostering ligand promiscuity to favor development of β chains with self-reactivity but is occluded by α subunit replacement of pTα upon αβTCR formation. At the double negative 3 thymocyte stage where the pre-TCR is first expressed, pre-TCR interaction with self-pMHC ligands imparts growth and survival advantages as revealed in thymic stromal cultures, imprinting fundamental self-reactivity in the T cell repertoire. Collectively, our data imply the existence of sequential mechanosensor αβTCR repertoire tuning via the pre-TCR. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Global warming may disproportionately affect larger adults in a predatory coral reef fish

KAUST Repository

Messmer, Vanessa

2016-11-03

Global warming is expected to reduce body sizes of ectothermic animals. Although the underlying mechanisms of size reductions remain poorly understood, effects appear stronger at latitudinal extremes (poles and tropics) and in aquatic rather than terrestrial systems. To shed light on this phenomenon, we examined the size dependence of critical thermal maxima (CTmax) and aerobic metabolism in a commercially important tropical reef fish, the leopard coral grouper (Plectropomus leopardus) following acclimation to current-day (28.5 °C) vs. projected end-of-century (33 °C) summer temperatures for the northern Great Barrier Reef (GBR). CTmax declined from 38.3 to 37.5 °C with increasing body mass in adult fish (0.45-2.82 kg), indicating that larger individuals are more thermally sensitive than smaller conspecifics. This may be explained by a restricted capacity for large fish to increase mass-specific maximum metabolic rate (MMR) at 33 °C compared with 28.5 °C. Indeed, temperature influenced the relationship between metabolism and body mass (0.02-2.38 kg), whereby the scaling exponent for MMR increased from 0.74 ± 0.02 at 28.5 °C to 0.79 ± 0.01 at 33 °C, and the corresponding exponents for standard metabolic rate (SMR) were 0.75 ± 0.04 and 0.80 ± 0.03. The increase in metabolic scaling exponents at higher temperatures suggests that energy budgets may be disproportionately impacted in larger fish and contribute to reduced maximum adult size. Such climate-induced reductions in body size would have important ramifications for fisheries productivity, but are also likely to have knock-on effects for trophodynamics and functioning of ecosystems.

Global warming may disproportionately affect larger adults in a predatory coral reef fish

KAUST Repository

Messmer, Vanessa; Pratchett, Morgan S.; Hoey, Andrew S.; Tobin, Andrew J.; Coker, Darren James; Cooke, Steven J.; Clark, Timothy D.

2016-01-01

Global warming is expected to reduce body sizes of ectothermic animals. Although the underlying mechanisms of size reductions remain poorly understood, effects appear stronger at latitudinal extremes (poles and tropics) and in aquatic rather than terrestrial systems. To shed light on this phenomenon, we examined the size dependence of critical thermal maxima (CTmax) and aerobic metabolism in a commercially important tropical reef fish, the leopard coral grouper (Plectropomus leopardus) following acclimation to current-day (28.5 °C) vs. projected end-of-century (33 °C) summer temperatures for the northern Great Barrier Reef (GBR). CTmax declined from 38.3 to 37.5 °C with increasing body mass in adult fish (0.45-2.82 kg), indicating that larger individuals are more thermally sensitive than smaller conspecifics. This may be explained by a restricted capacity for large fish to increase mass-specific maximum metabolic rate (MMR) at 33 °C compared with 28.5 °C. Indeed, temperature influenced the relationship between metabolism and body mass (0.02-2.38 kg), whereby the scaling exponent for MMR increased from 0.74 ± 0.02 at 28.5 °C to 0.79 ± 0.01 at 33 °C, and the corresponding exponents for standard metabolic rate (SMR) were 0.75 ± 0.04 and 0.80 ± 0.03. The increase in metabolic scaling exponents at higher temperatures suggests that energy budgets may be disproportionately impacted in larger fish and contribute to reduced maximum adult size. Such climate-induced reductions in body size would have important ramifications for fisheries productivity, but are also likely to have knock-on effects for trophodynamics and functioning of ecosystems.

Global warming may disproportionately affect larger adults in a predatory coral reef fish.

Science.gov (United States)

Messmer, Vanessa; Pratchett, Morgan S; Hoey, Andrew S; Tobin, Andrew J; Coker, Darren J; Cooke, Steven J; Clark, Timothy D

2017-06-01

Global warming is expected to reduce body sizes of ectothermic animals. Although the underlying mechanisms of size reductions remain poorly understood, effects appear stronger at latitudinal extremes (poles and tropics) and in aquatic rather than terrestrial systems. To shed light on this phenomenon, we examined the size dependence of critical thermal maxima (CTmax) and aerobic metabolism in a commercially important tropical reef fish, the leopard coral grouper (Plectropomus leopardus) following acclimation to current-day (28.5 °C) vs. projected end-of-century (33 °C) summer temperatures for the northern Great Barrier Reef (GBR). CTmax declined from 38.3 to 37.5 °C with increasing body mass in adult fish (0.45-2.82 kg), indicating that larger individuals are more thermally sensitive than smaller conspecifics. This may be explained by a restricted capacity for large fish to increase mass-specific maximum metabolic rate (MMR) at 33 °C compared with 28.5 °C. Indeed, temperature influenced the relationship between metabolism and body mass (0.02-2.38 kg), whereby the scaling exponent for MMR increased from 0.74 ± 0.02 at 28.5 °C to 0.79 ± 0.01 at 33 °C, and the corresponding exponents for standard metabolic rate (SMR) were 0.75 ± 0.04 and 0.80 ± 0.03. The increase in metabolic scaling exponents at higher temperatures suggests that energy budgets may be disproportionately impacted in larger fish and contribute to reduced maximum adult size. Such climate-induced reductions in body size would have important ramifications for fisheries productivity, but are also likely to have knock-on effects for trophodynamics and functioning of ecosystems. © 2016 John Wiley & Sons Ltd.

Study of RpI22 in MDS and AML

Science.gov (United States)

2016-12-01

developed significantly larger and markedly more vascularized thymic tumors than those observed in Rpl22þ/þ control mice. But, unlike Rpl22þ/þ or Rpl22þ...hypoxia (31). Alternatively, we did not observe obvious necrosis in the center of the large thymic tumors from Rpl22-deficent mice, suggesting Rpl22...Orthop Res 2004;22:1175–81. 32. Loeffler S, Fayard B, Weis J, Weissenberger J. Interleukin-6 induces tran- scriptional activation of vascular endothelial

Gigantic enlargement of the thymus gland

International Nuclear Information System (INIS)

Regal, Mohamed A.

2007-01-01

True massive thymic hyperplasia is a very rare entity, characterized by an increase in the size and weight of the thymus gland without an apparent cause. Surgery has been required in patients with severe respiratory distress. We present an idiopathic true massive thymic hyperplasia in a 5-month-old boy. (author)

Epithelial cells prime the immune response to an array of gut-derived commensals towards a tolerogenic phenotype through distinct actions of thymic stromal lymphopoietin and transforming growth factor-beta

DEFF Research Database (Denmark)

Zeuthen, Louise Hjerrild; Fink, Lisbeth Nielsen; Frøkiær, Hanne

2007-01-01

in DC priming of naive T cells with elevated levels of transforming growth factor-beta (TGF-beta) and markedly reduced levels of bacteria-induced interferon-gamma production. Caco2 cell production of IL-8, thymic stromal lymphopoietin (TSLP) and TGF-beta increases upon microbial stimulation in a strain...

More ‘altruistic’ punishment in larger societies

Science.gov (United States)

Marlowe, Frank W; Berbesque, J. Colette; Barr, Abigail; Barrett, Clark; Bolyanatz, Alexander; Cardenas, Juan Camilo; Ensminger, Jean; Gurven, Michael; Gwako, Edwins; Henrich, Joseph; Henrich, Natalie; Lesorogol, Carolyn; McElreath, Richard; Tracer, David

2007-01-01

If individuals will cooperate with cooperators, and punish non-cooperators even at a cost to themselves, then this strong reciprocity could minimize the cheating that undermines cooperation. Based upon numerous economic experiments, some have proposed that human cooperation is explained by strong reciprocity and norm enforcement. Second-party punishment is when you punish someone who defected on you; third-party punishment is when you punish someone who defected on someone else. Third-party punishment is an effective way to enforce the norms of strong reciprocity and promote cooperation. Here we present new results that expand on a previous report from a large cross-cultural project. This project has already shown that there is considerable cross-cultural variation in punishment and cooperation. Here we test the hypothesis that population size (and complexity) predicts the level of third-party punishment. Our results show that people in larger, more complex societies engage in significantly more third-party punishment than people in small-scale societies. PMID:18089534

A human thymic epithelial cell culture system for the promotion of lymphopoiesis from hematopoietic stem cells.

Science.gov (United States)

Beaudette-Zlatanova, Britte C; Knight, Katherine L; Zhang, Shubin; Stiff, Patrick J; Zúñiga-Pflücker, Juan Carlos; Le, Phong T

2011-05-01

A human thymic epithelial cell (TEC) line expressing human leukocyte antigen-ABC and human leukocyte antigen-DR was engineered to overexpress murine Delta-like 1 (TEC-Dl1) for the purpose of establishing a human culture system that supports T lymphopoiesis from hematopoietic progenitor cells (HPCs). Cord blood or bone marrow HPCs were co-cultured with either the parental TEC line expressing low levels of the Notch ligands, Delta-like 1 and Delta-like 4, or with TEC-Dl1 to determine if these cell lines support human lymphopoiesis. In co-cultures with cord blood or bone marrow HPCs, TEC-Dl1 cells promote de novo generation of CD7(pos)CD1a(pos) T-lineage committed cells. Most CD7(pos)CD1a(hi) cells are CD4(pos)CD8(pos) double-positive (DP). We found that TEC-Dl1 cells are insufficient to generate mature CD3(hi) CD4(pos) or CD3(hi) CD8(pos) single-positive (SP) T cells from the CD4(pos)CD8(pos) DP T cells; however, we detected CD3(lo) cells within the DP and SP CD4 and CD8 populations. The CD3(lo) SP cells expressed lower levels of interleukin-2Rα and interleukin-7Rα compared to CD3(lo) DP cells. In contrast to the TEC-Dl1 line, the parental TEC-84 line expressing low levels of human Notch ligands permits HPC differentiation to the B-cell lineage. We report for the first time a human TEC line that supports lymphopoiesis from cord blood and bone marrow HPC. The TEC cell lines described herein provide a novel human thymic stroma model to study the contribution of human leukocyte antigen molecules and Notch ligands to T-cell commitment and maturation and could be utilized to promote lymphopoiesis for immune cell therapy. Copyright © 2011 ISEH - Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

Polyhexamethyleneguanidine phosphate induces severe lung inflammation, fibrosis, and thymic atrophy.

Science.gov (United States)

Song, Jeong Ah; Park, Hyun-Ju; Yang, Mi-Jin; Jung, Kyung Jin; Yang, Hyo-Seon; Song, Chang-Woo; Lee, Kyuhong

2014-07-01

Polyhexamethyleneguanidine phosphate (PHMG-P) has been widely used as a disinfectant because of its strong bactericidal activity and low toxicity. However, in 2011, the Korea Centers for Disease Control and Prevention and the Ministry of Health and Welfare reported that a suspicious outbreak of pulmonary disease might have originated from humidifier disinfectants. The purpose of this study was to assess the toxicity of PHMG-P following direct exposure to the lung. PHMG-P (0.3, 0.9, or 1.5 mg/kg) was instilled into the lungs of mice. The levels of proinflammatory markers and fibrotic markers were quantified in lung tissues and flow cytometry was used to evaluate T cell distribution in the thymus. Administration of PHMG-P induced proinflammatory cytokines elevation and infiltration of immune cells into the lungs. Histopathological analysis revealed a dose-dependent exacerbation of both inflammation and pulmonary fibrosis on day 14. PHMG-P also decreased the total cell number and the CD4(+)/CD8(+) cell ratio in the thymus, with the histopathological examination indicating severe reduction of cortex and medulla. The mRNA levels of biomarkers associated with T cell development also decreased markedly. These findings suggest that exposure of lung tissue to PHMG-P leads to pulmonary inflammation and fibrosis as well as thymic atrophy. Copyright © 2014 Elsevier Ltd. All rights reserved.

Computed tomography of the thymus after pneumomediastinography in patients with myasthenia gravis

International Nuclear Information System (INIS)

Hirose, Genjiro; Yamamoto, Teiji; Kosoegawa, Hiroshi; Saeki, Mitsuo; Hayashi, Toshiharu

1982-01-01

Nine patients with myasthenia gravis (MG) had plain chest X-ray, tomography, computed tomography (CT) of the thorax, pneumomediastinography (PMG) and post-PMG CT scans. Routine chest radiography detected mediastinal masses in two patients and conventional laminogram provided no additional informations. CT yielded anterior mediastinal increased densities in seven patients (78%), whereas post-PMG CT delineated masses (thymoma or thymic hyperplasia) or thymic gland in all cases (100%), but these procedures could not distinguish thymic tumor from nontumorous conditions. PMG and post-PMG CT scans are superior to other radiographic techniques in detecting mediastinal abnormalities with more clear delineation of thymoma or thymic gland. When an abnormal density is present in the mediastinum of a patient with MG, PMG and post-PMG CT scans should be done to outline the mediastinal anatomy, to determine the size, extent, invasiveness of thymoma or thymic gland prior to thymectomy. (author)

Computed tomography of the thymus after pneumomediastinography in patients with myasthenia gravis

Energy Technology Data Exchange (ETDEWEB)

Hirose, Genjiro; Yamamoto, Teiji; Kosoegawa, Hiroshi; Saeki, Mitsuo; Hayashi, Toshiharu (Kanazawa Medical Univ., Ishikawa (Japan))

1982-09-01

Nine patients with myasthenia gravis (MG) had plain chest X-ray, tomography, computed tomography (CT) of the thorax, pneumomediastinography (PMG) and post-PMG CT scans. Routine chest radiography detected mediastinal masses in two patients and conventional laminogram provided no additional information. CT yielded anterior mediastinal increased densities in seven patients (78%), whereas post-PMG CT delineated masses (thymoma or thymic hyperplasia) or thymic gland in all cases (100%), but these procedures could not distinguish thymic tumor from nontumorous conditions. PMG and post-PMG CT scans are superior to other radiographic techniques in detecting mediastinal abnormalities with more clear delineation of thymoma or thymic gland. When an abnormal density is present in the mediastinum of a patient with MG, PMG and post-PMG CT scans should be done to outline the mediastinal anatomy, to determine the size, extent, invasiveness of thymoma or thymic gland prior to thymectomy.

Apparent failure of thymic epithelium transplants to alter the course of autoimmune disease in NZB/W mice

International Nuclear Information System (INIS)

Morrow, W.J.W.; Nayak, R.C.; Cooke, A.; Roitt, I.M.

1982-01-01

Thymic epithelium from neonatal DBA/2 mice (H-2sup(d)) was placed under the kidney capsule of 10- to 12-wk-old female NZB/W mice (H-2sup(d/z)). Donor epithelium, equivalent to 1-2 lobes of neonatal thymus, was either irradiated (1300 rad.) or cultured for 7 days in order to minimise host-versus-graft reactions. Histological examination showed that the epithelium repopulated and remained in place until the end of the experiment, with no sign of rejection. Despite this, the treated animals lived no longer than the untreated or sham operated controls. Levels of anti-nuclear antibody and serum IgM (normally highly elevated in these animals) were not significantly different in any group. (Auth.)

A general model for the scaling of offspring size and adult size.

Science.gov (United States)

Falster, Daniel S; Moles, Angela T; Westoby, Mark

2008-09-01

Understanding evolutionary coordination among different life-history traits is a key challenge for ecology and evolution. Here we develop a general quantitative model predicting how offspring size should scale with adult size by combining a simple model for life-history evolution with a frequency-dependent survivorship model. The key innovation is that larger offspring are afforded three different advantages during ontogeny: higher survivorship per time, a shortened juvenile phase, and advantage during size-competitive growth. In this model, it turns out that size-asymmetric advantage during competition is the factor driving evolution toward larger offspring sizes. For simplified and limiting cases, the model is shown to produce the same predictions as the previously existing theory on which it is founded. The explicit treatment of different survival advantages has biologically important new effects, mainly through an interaction between total maternal investment in reproduction and the duration of competitive growth. This goes on to explain alternative allometries between log offspring size and log adult size, as observed in mammals (slope = 0.95) and plants (slope = 0.54). Further, it suggests how these differences relate quantitatively to specific biological processes during recruitment. In these ways, the model generalizes across previous theory and provides explanations for some differences between major taxa.

The actin regulator coronin-1A is mutated in a thymic egress deficient mouse strain and in a T?B+NK+ SCID patient

OpenAIRE

Shiow, Lawrence R.; Roadcap, David W.; Paris, Kenneth; Watson, Susan R.; Grigorova, Irina L.; Lebet, Tonya; An, Jinping; Xu, Ying; Jenne, Craig N.; F?ger, Niko; Sorensen, Ricardo U.; Goodnow, Christopher C.; Bear, James E.; Puck, Jennifer M.; Cyster, Jason G.

2008-01-01

Mice carrying the recessive peripheral T cell deficiency (Ptcd) locus have a block in thymic egress but the mechanism responsible is undefined. Here we found that Ptcd T cells have an intrinsic migration defect, impaired lymphoid tissue trafficking and irregularly shaped protrusions. Characterization of the Ptcd locus revealed an E26K point mutation within the actin regulator coronin-1A (Coro1a) that enhanced its inhibition of the actin regulator Arp2/3 and resulted in its mislocalization fro...

Body size and predatory performance in wolves: is bigger better?

Science.gov (United States)

MacNulty, Daniel R; Smith, Douglas W; Mech, L David; Eberly, Lynn E

2009-05-01

1. Large body size hinders locomotor performance in ways that may lead to trade-offs in predator foraging ability that limit the net predatory benefit of larger size. For example, size-related improvements in handling prey may come at the expense of pursuing prey and thus negate any enhancement in overall predatory performance due to increasing size. 2. This hypothesis was tested with longitudinal data from repeated observations of 94 individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park, USA. Wolf size was estimated from an individually based sex-specific growth model derived from body mass measurements of 304 wolves. 3. Larger size granted individual wolves a net predatory advantage despite substantial variation in its effect on the performance of different predatory tasks; larger size improved performance of a strength-related task (grappling and subduing elk) but failed to improve performance of a locomotor-related task (selecting an elk from a group) for wolves > 39 kg. 4. Sexual dimorphism in wolf size also explained why males outperformed females in each of the three tasks considered (attacking, selecting, and killing). 5. These findings support the generalization that bigger predators are overall better hunters, but they also indicate that increasing size ultimately limits elements of predatory behaviour that require superior locomotor performance. We argue that this could potentially narrow the dietary niche of larger carnivores as well as limit the evolution of larger size if prey are substantially more difficult to pursue than to handle.

FOXN1GFP/w Reporter hESCs Enable Identification of Integrin-β4, HLA-DR, and EpCAM as Markers of Human PSC-Derived FOXN1+ Thymic Epithelial Progenitors

Directory of Open Access Journals (Sweden)

Chew-Li Soh

2014-06-01

Full Text Available Thymic epithelial cells (TECs play a critical role in T cell maturation and tolerance induction. The generation of TECs from in vitro differentiation of human pluripotent stem cells (PSCs provides a platform on which to study the mechanisms of this interaction and has implications for immune reconstitution. To facilitate analysis of PSC-derived TECs, we generated hESC reporter lines in which sequences encoding GFP were targeted to FOXN1, a gene required for TEC development. Using this FOXN1GFP/w line as a readout, we developed a reproducible protocol for generating FOXN1-GFP+ thymic endoderm cells. Transcriptional profiling and flow cytometry identified integrin-β4 (ITGB4, CD104 and HLA-DR as markers that could be used in combination with EpCAM to selectively purify FOXN1+ TEC progenitors from differentiating cultures of unmanipulated PSCs. Human FOXN1+ TEC progenitors generated from PSCs facilitate the study of thymus biology and are a valuable resource for future applications in regenerative medicine.

Size Evolution and Stochastic Models: Explaining Ostracod Size through Probabilistic Distributions

Science.gov (United States)

Krawczyk, M.; Decker, S.; Heim, N. A.; Payne, J.

2014-12-01

The biovolume of animals has functioned as an important benchmark for measuring evolution throughout geologic time. In our project, we examined the observed average body size of ostracods over time in order to understand the mechanism of size evolution in these marine organisms. The body size of ostracods has varied since the beginning of the Ordovician, where the first true ostracods appeared. We created a stochastic branching model to create possible evolutionary trees of ostracod size. Using stratigraphic ranges for ostracods compiled from over 750 genera in the Treatise on Invertebrate Paleontology, we calculated overall speciation and extinction rates for our model. At each timestep in our model, new lineages can evolve or existing lineages can become extinct. Newly evolved lineages are assigned sizes based on their parent genera. We parameterized our model to generate neutral and directional changes in ostracod size to compare with the observed data. New sizes were chosen via a normal distribution, and the neutral model selected new sizes differentials centered on zero, allowing for an equal chance of larger or smaller ostracods at each speciation. Conversely, the directional model centered the distribution on a negative value, giving a larger chance of smaller ostracods. Our data strongly suggests that the overall direction of ostracod evolution has been following a model that directionally pushes mean ostracod size down, shying away from a neutral model. Our model was able to match the magnitude of size decrease. Our models had a constant linear decrease while the actual data had a much more rapid initial rate followed by a constant size. The nuance of the observed trends ultimately suggests a more complex method of size evolution. In conclusion, probabilistic methods can provide valuable insight into possible evolutionary mechanisms determining size evolution in ostracods.

Modelling the effect of size-asymmetric competition on size inequality

DEFF Research Database (Denmark)

Rasmussen, Camilla Ruø; Weiner, Jacob

2017-01-01

Abstract The concept of size asymmetry in resource competition among plants, in which larger individuals obtain a disproportionate share of contested resources, appears to be very straightforward, but the effects of size asymmetry on growth and size variation among individuals have proved...... to be controversial. It has often been assumed that competition among individual plants in a population has to be size-asymmetric to result in higher size inequality than in the absence of competition, but here we question this inference. Using very simple, individual-based models, we investigate how size symmetry...... of competition affects the development in size inequality between two competing plants and show that increased size inequality due to competition is not always strong evidence for size-asymmetric competition. Even absolute symmetric competition, in which all plants receive the same amount of resources...

Class size versus class composition

DEFF Research Database (Denmark)

Jones, Sam

Raising schooling quality in low-income countries is a pressing challenge. Substantial research has considered the impact of cutting class sizes on skills acquisition. Considerably less attention has been given to the extent to which peer effects, which refer to class composition, also may affect...... bias from omitted variables, the preferred IV results indicate considerable negative effects due to larger class sizes and larger numbers of overage-for-grade peers. The latter, driven by the highly prevalent practices of grade repetition and academic redshirting, should be considered an important...

The body size of the oil-collecting bee Tetrapedia diversipes (Apidae)

OpenAIRE

Pinto da Silva,Carlos; Silva,Adriana; Duran Cordeiro,Guaraci; Alves dos Santos ,Isabel

2015-01-01

The body size of bees can affect their fitness in many ways. There is an indirect relationship between the size of the mother and the size of her progeny. This is so because large mothers use larger nests and brood cells and have higher foraging capacity than small mothers, and consequently large mothers supply a larger amount of food to their larvae, which grow larger. We analyzed the relationship between body size of individual oil-collecting bees of the species Tetrapedia diversipes and th...

Body size and predatory performance in wolves: Is bigger better?

Science.gov (United States)

MacNulty, D.R.; Smith, D.W.; Mech, L.D.; Eberly, L.E.

2009-01-01

Large body size hinders locomotor performance in ways that may lead to trade-offs in predator foraging ability that limit the net predatory benefit of larger size. For example, size-related improvements in handling prey may come at the expense of pursuing prey and thus negate any enhancement in overall predatory performance due to increasing size. 2. This hypothesis was tested with longitudinal data from repeated observations of 94 individually known wolves (Canis lupus) hunting elk (Cervus elaphus) in Yellowstone National Park, USA. Wolf size was estimated from an individually based sex-specific growth model derived from body mass measurements of 304 wolves. 3. Larger size granted individual wolves a net predatory advantage despite substantial variation in its effect on the performance of different predatory tasks; larger size improved performance of a strength-related task (grappling and subduing elk) but failed to improve performance of a locomotor-related task (selecting an elk from a group) for wolves > 39 kg. 4. Sexual dimorphism in wolf size also explained why males outperformed females in each of the three tasks considered (attacking, selecting, and killing). 5. These findings support the generalization that bigger predators are overall better hunters, but they also indicate that increasing size ultimately limits elements of predatory behaviour that require superior locomotor performance. We argue that this could potentially narrow the dietary niche of larger carnivores as well as limit the evolution of larger size if prey are substantially more difficult to pursue than to handle. ?? 2009 British Ecological Society.

Stereotactic Radiosurgery with Neoadjuvant Embolization of Larger Arteriovenous Malformations: An Institutional Experience

Directory of Open Access Journals (Sweden)

Richard Dalyai

2014-01-01

Full Text Available Objective. This study investigates the safety and efficacy of a multimodality approach combining staged endovascular embolizations with subsequent SRS for the management of larger AVMs. Methods. Ninety-five patients with larger AVMs were treated with staged endovascular embolization followed by SRS between 1996 and 2011. Results. The median volume of AVM in this series was 28 cm3 and 47 patients (48% were Spetzler-Martin grade IV or V. Twenty-seven patients initially presented with hemorrhage. Sixty-one patients underwent multiple embolizations while a single SRS session was performed in 64 patients. The median follow-up after SRS session was 32 months (range 9–136 months. Overall procedural complications occurred in 14 patients. There were 13 minor neurologic complications and 1 major complication (due to embolization while four patients had posttreatment hemorrhage. Thirty-eight patients (40% were cured radiographically. The postradiosurgery actuarial rate of obliteration was 45% at 5 years, 56% at 7 years, and 63% at 10 years. In multivariate analysis, larger AVM size, deep venous drainage, and the increasing number of embolization/SRS sessions were negative predictors of obliteration. The number of embolizations correlated positively with the number of stereotactic radiosurgeries (P<0.005. Conclusions. Multimodality endovascular and radiosurgical approach is an efficacious treatment strategy for large AVM.

Mammal extinctions, body size, and paleotemperature.

Science.gov (United States)

Bown, T M; Holroyd, P A; Rose, K D

1994-10-25

There is a general inverse relationship between the natural logarithm of tooth area (a body size indicator) of some fossil mammals and paleotemperature during approximately 2.9 million years of the early Eocene in the Bighorn Basin of northwest Wyoming. When mean temperatures became warmer, tooth areas tended to become smaller. During colder times, larger species predominated; these generally became larger or remained the same size. Paleotemperature trends also markedly affected patterns of local (and, perhaps, regional) extinction and immigration. New species appeared as immigrants during or near the hottest (smaller forms) and coldest (larger forms) intervals. Paleotemperature trend reversals commonly resulted in the ultimate extinction of both small forms (during cooling intervals) and larger forms (during warming intervals). These immigrations and extinctions mark faunal turnovers that were also modulated by sharp increases in sediment accumulation rate.

Adipocyte and leptin accumulation in tumor-induced thymic involution.

Science.gov (United States)

Lamas, Alejandro; Lopez, Elena; Carrio, Roberto; Lopez, Diana M

2016-01-01

Cell-mediated immunity is an important defense mechanism against pathogens and developing tumor cells. The thymus is the main lymphoid organ involved in the formation of the cell-mediated immune response by the maturation and differentiation of lymphocytes that travel from the bone marrow, through the lymphatic ducts, to become T lymphocytes. Thymic involution has been associated with aging; however, other factors such as obesity, viral infection and tumor development have been shown to increase the rate of shrinkage of this organ. The heavy infiltration of adipocyte fat cells has been reported in the involuted thymuses of aged mice. In the present study, the possible accumulation of such cells in the thymus during tumorigenesis was examined by immunohistochemistry. A significant number of adipocytes around and infiltrating the thymuses of tumor-bearing mice was observed. Leptin is a pro-inflammatory adipocytokine that enhances thymopoiesis and modulates T cell immune responses. The levels of leptin and adiponectin, another adipocytokine that has anti-inflammatory properties, were examined by western blot analysis. While no changes were observed in the amounts of adiponectin present in the thymuses of the normal and tumor-bearing mice, significantly higher levels of leptin were detected in the thymocytes of the tumor-bearing mice. This correlated with an increase in the expression of certain cytokines, such as interleukin (IL)-2, interferon (IFN)-γ and granulocyte-macrophage colony-stimulating factor (GM-CSF). The co-culture of thymocytes isolated from normal mice with ex vivo isolated adipocytes from tumor-bearing mice yielded similar results. Our findings suggest that the infiltration and accumulation of adipocytes in the thymuses of tumor-bearing mice play an important role in their altered morphology and functions.

Lineage Tracing and Cell Ablation Identify a Post-Aire-Expressing Thymic Epithelial Cell Population

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Todd C. Metzger

2013-10-01

Full Text Available Thymic epithelial cells in the medulla (mTECs play a critical role in enforcing central tolerance through expression and presentation of tissue-specific antigens (TSAs and deletion of autoreactive thymocytes. TSA expression requires autoimmune regulator (Aire, a transcriptional activator present in a subset of mTECs characterized by high CD80 and major histocompatibility complex II expression and a lack of potential for differentiation or proliferation. Here, using an Aire-DTR transgenic line, we show that short-term ablation specifically targets Aire+ mTECs, which quickly undergo RANK-dependent recovery. Repeated ablation also affects Aire− mTECs, and using an inducible Aire-Cre fate-mapping system, we find that this results from the loss of a subset of mTECs that showed prior expression of Aire, maintains intermediate TSA expression, and preferentially migrates toward the center of the medulla. These results clearly identify a distinct stage of mTEC development and underscore the diversity of mTECs that play a key role in maintaining tolerance.

New Regimes of Implosions of Larger Sized Wire Arrays With and Without Modified Central Plane at 1.5-1.7 MA Zebra

Science.gov (United States)

Safronova, A. S.; Kantsyrev, V. L.; Esaulov, A. A.; Weller, M. E.; Shrestha, I.; Shlyaptseva, V. V.; Stafford, A.; Keim, S. F.; Petkov, E. E.; Lorance, M.; Chuvatin, A. S.; Coverdale, C. A.; Jones, B.

2013-10-01

The recent experiments at 1.5-1.7 MA on Zebra at UNR with larger sized planar wires arrays (compared to the wire loads at 1 MA current) have demonstrated higher linear radiation yield and electron temperatures as well as advantages of better diagnostics access to observable plasma regions. Such multi-planar wire arrays had two outer wire planes from mid-Z material to create a global magnetic field (gmf) and mid-Z plasma flow between them. Also, they included a modified central plane with a few Al wires at the edges to influence gmf and to create Al plasma flow in the perpendicular direction. The stationary shock waves which existed over tens of ns on shadow images and the early x-ray emissions before the PCD peak on time-gated spectra were observed. The most recent experiments with similar loads but without the central wires demonstrated a very different regime of implosion with asymmetrical jets and no precursor formation. This work was supported by NNSA under DOE Cooperative Agreement DE-NA0001984 and in part by DE-FC52-06NA27616. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

Perioperative Outcomes and Long-term Survival in Clinically Early-stage Thymic 
Malignancies: Video-assisted Thoracoscopic Thymectomy versus Open Approaches

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Hao WANG

2016-07-01

Full Text Available Background and objective Video-assisted thoracoscopic surgery (VATS theoretically offers advantages over open thymectomy for clinically early-stage (Masaoka-Koga stage I and II thymic malignancies. However, longterm outcomes have not been well studied. We compared the postoperative outcomes and survival from a cohort study based on the database of the Chinese Alliance for Research in Thymomas (ChART. Methods Between 1994 and 2012, data of 1,117 patients having surgery for clinically early-stage (Masaoka-Koga stage I and II tumors were enrolled for the study. Among them, 241 cases underwent VATS thymectomy (VATS group, while 876 cases underwent open thymectomy (Open group. Univariate analyses were used to compare the clinical character and perioperative outcomes between the two groups. And multivariate analysis was performed to determine the independent predictive factors for long-term survival. Results Compared with the Open group, the VATS group had higher percentage of total thymectomy (80.5% vs 73.9%, P=0.028, resection rate (98.8% vs 88.7%, P<0.001 and less recurrence (2.9% vs 16.0%, P<0.001. Five-year overall survival was 92% after VATS and 92% after open thymectomy, with no significant difference between the two groups (P=0.15. However, 5-year disease free survival were 92% in VATS group and 83% in Open group (P=0.011. Cox proportional hazards model revealed that WHO classification, Masaoka-Koga stage and adjuvant therapy were independent predictive factors for overall survival, while surgical approach had no significant impact on long-term outcome. Conclusion This study suggests that VATS thymectomy is an effective approach for clinically early-stage thymic malignancies. And it may offer better perioperative outcomes, as well as equal oncological survival.

Speaker Input Variability Does Not Explain Why Larger Populations Have Simpler Languages.

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Atkinson, Mark; Kirby, Simon; Smith, Kenny

2015-01-01

A learner's linguistic input is more variable if it comes from a greater number of speakers. Higher speaker input variability has been shown to facilitate the acquisition of phonemic boundaries, since data drawn from multiple speakers provides more information about the distribution of phonemes in a speech community. It has also been proposed that speaker input variability may have a systematic influence on individual-level learning of morphology, which can in turn influence the group-level characteristics of a language. Languages spoken by larger groups of people have less complex morphology than those spoken in smaller communities. While a mechanism by which the number of speakers could have such an effect is yet to be convincingly identified, differences in speaker input variability, which is thought to be larger in larger groups, may provide an explanation. By hindering the acquisition, and hence faithful cross-generational transfer, of complex morphology, higher speaker input variability may result in structural simplification. We assess this claim in two experiments which investigate the effect of such variability on language learning, considering its influence on a learner's ability to segment a continuous speech stream and acquire a morphologically complex miniature language. We ultimately find no evidence to support the proposal that speaker input variability influences language learning and so cannot support the hypothesis that it explains how population size determines the structural properties of language.

Tumor carcinóide do timo - Caso clínico Thymic carcinoid - case report

Directory of Open Access Journals (Sweden)

Lina Carvalho

2010-01-01

Full Text Available Os tumores neuroendócrinos primários representam cerca de 4% do total dos tumores do mediastino anterior, incluindo o timo, afectando mais homens que mulheres numa razão de 3:1 e apresentando uma maior incidência entre os 40 e os 60 anos. Antigamente classificados como timomas, desde 1972 são considerados um grupo distinto de neoplasias tímicas, podendo ser biologicamente activos, estando sobretudo associados à síndroma NEM-1 (19 a 25% dos doentes, sendo nestes casos mais agressivos. São descritos como tendo grande progressão local, recorrência e metástases em elevada percentagem de casos, o que determina um mau prognóstico. O estadiamento é o parâmetro mais importante para determinar a sobrevida. Tumores detectados em fase precoce e capsulados associam-se a um excelente prognóstico, enquanto em estádios avançados, localmente invasivos, têm prognóstico relativamente pobre. A remoção cirúrgica completa, para todos os tumores tímicos, é a base da terapêutica e o factor crítico para a sobrevivência a longo prazo, independentemente do tipo histológico. São uma causa de morte importante, nomeadamente os tumores associados a NEM-1 e síndroma de Cushing, e há autores que defendem a realização de timectomia profiláctica nestes doentes.Primary neuroendocrine tumours (carcinoid tumours account for about 4% of anterior mediastinal tumours concerning thymus localization. They appear to have a male predilection (3:1 ratio and occur mostly between 40 and 60 years of age. Classified primarily as thymomas, they have been considered a different group of thymic neoplasia since 1972. They can be biologically active, mostly associated with MEN-1 (19-25% of patients and more aggressive in these cases. As a locally invasive disease, with recurrence and metastasis in a high percentage of cases, it correlates with a poor prognosis. Staging is the most important determinant of survival. Encapsulated tumours diagnosed in early stages

The discrepancy between emotional vs. rational estimates of body size, actual size, and ideal body ratings: theoretical and clinical implications.

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Thompson, J K; Dolce, J J

1989-05-01

Thirty-two asymptomatic college females were assessed on multiple aspects of body image. Subjects' estimation of the size of three body sites (waist, hips, thighs) was affected by instructional protocol. Emotional ratings, based on how they "felt" about their body, elicited ratings that were larger than actual and ideal size measures. Size ratings based on rational instructions were no different from actual sizes, but were larger than ideal ratings. There were no differences between actual and ideal sizes. The results are discussed with regard to methodological issues involved in body image research. In addition, a working hypothesis that differentiates affective/emotional from cognitive/rational aspects of body size estimation is offered to complement current theories of body image. Implications of the findings for the understanding of body image and its relationship to eating disorders are discussed.

Immunologic mechanism of the suppressive effect of low dose radiation on thymic lymphoma induced by radiation

International Nuclear Information System (INIS)

Li Xiujuan; Yang Ying; Li Xiuyi; Liu Shuzheng

1999-01-01

To study immunologic mechanism of the suppressive effect of low dose radiation (LDR) on thymic lymphoma (TL) induced by high dose radiation (HDR). The authors adopted the model that C57BL/6J mice were administered whole body irradiation with 1.75 Gy X-rays one time every week for 4 weeks to induce TL. It was examined that splenic NK cytotoxic activity, IL-2 and γ-IFN secretion activity, peritoneal macrophage phagocytosis and its TNF-α secretion activity in mice with different dose 1 month after irradiation. The results showed that all the immunologic functions mentioned above in mice given 75 mGy 12 h before 1.75 Gy every time were higher than that in mice given only 1.75 Gy, and approached to the sham-irradiation mice. It suggested that the suppressive effect of LDR on TL induced by HDR may be related to the adaptive response induced by LDR and decreasing immunological functions damage caused by HDR

Generation of mature T cells from human hematopoietic stem and progenitor cells in artificial thymic organoids.

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Seet, Christopher S; He, Chongbin; Bethune, Michael T; Li, Suwen; Chick, Brent; Gschweng, Eric H; Zhu, Yuhua; Kim, Kenneth; Kohn, Donald B; Baltimore, David; Crooks, Gay M; Montel-Hagen, Amélie

2017-05-01

Studies of human T cell development require robust model systems that recapitulate the full span of thymopoiesis, from hematopoietic stem and progenitor cells (HSPCs) through to mature T cells. Existing in vitro models induce T cell commitment from human HSPCs; however, differentiation into mature CD3 + TCR-αβ + single-positive CD8 + or CD4 + cells is limited. We describe here a serum-free, artificial thymic organoid (ATO) system that supports efficient and reproducible in vitro differentiation and positive selection of conventional human T cells from all sources of HSPCs. ATO-derived T cells exhibited mature naive phenotypes, a diverse T cell receptor (TCR) repertoire and TCR-dependent function. ATOs initiated with TCR-engineered HSPCs produced T cells with antigen-specific cytotoxicity and near-complete lack of endogenous TCR Vβ expression, consistent with allelic exclusion of Vβ-encoding loci. ATOs provide a robust tool for studying human T cell differentiation and for the future development of stem-cell-based engineered T cell therapies.

A change in competitive context reverses sexual selection on male size.

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Kasumovic, M M; Andrade, M C B

2009-02-01

In studies of sexual selection, larger size is often argued to increase male fitness, and relatively smaller males are explained by genetic and/or environmental variation. We demonstrate that a size-development life-history trade-off could underlie the maintenance of a broad, unimodal distribution of size in male redback spiders (Latrodectus hasselti). Larger males are superior in direct competition, but redback males mature rapidly at small size in the presence of females. In field enclosures, we simulated two competitive contexts favouring development of divergent male sizes. Relatively smaller males lost when competing directly, but had 10 times higher fitness than relatively larger males when given the temporal advantage of rapid development. Linear selection gradients confirmed the reversal of selection on size, showing that it is critical to consider life-history decisions underlying the development of traits related to fitness.

Effects of 2,3,7,8-TCDD and PCB 126 on human thymic epithelial cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Riecke, Kai [Institut fuer Klinische Pharmakologie und Toxikologie (Abt. Toxikologie), Universitaetsklinikum Benjamin Franklin, Freie Universitaet Berlin, Garystrasse 5, 14195, Berlin (Germany); Experimental Toxicology, Schering AG, 10334, Berlin (Germany); Schmidt, Andre; Stahlmann, Ralf [Institut fuer Klinische Pharmakologie und Toxikologie (Abt. Toxikologie), Universitaetsklinikum Benjamin Franklin, Freie Universitaet Berlin, Garystrasse 5, 14195, Berlin (Germany)

2003-06-01

2,3,7,8-Tetrachloro-dibenzo-p-dioxin (TCDD) is a ubiquitously distributed xenobiotic. The adverse effects of TCDD on the mammalian immune system have been studied for decades, but it is still unclear whether TCDD has direct effects on T-lymphocytes or whether it acts via the thymic microenvironment. We have studied the effects of TCDD on primary cultures of human thymic epithelial cells (TEC) focusing on differentiation markers, integrins and adhesion molecules involved in cell-cell and in cell-matrix interactions. TEC were treated with TCDD at concentrations of 0.001, 0.01, 0.1, 1.0 or 10.0 nM or with 100 nM PCB 126 (3,3',4,4',5-pentachlorobiphenyl) for 3 days, and were then analysed by flow cytometry for expression of surface antigens using monoclonal antibodies against Hassall's bodies (TE-8, TE-16) or against surface structures such as CD29, CD49b, CD49e, CD49f, CD51, CD54, CD58, CD61 and CD106. At TCDD concentrations as low as 0.01 nM we found a significant increase in terminally differentiated, TE-16-positive TEC; at a ten-fold greater concentration the number of cells marked with the TE-8 antibody was also increased. With both markers the most pronounced effect (approximately +15%) was observed at 1 nM TCDD. An increase of cells expressing the integrin {alpha}-chains CD49b, CD49e and CD51 as well as CD54 was observed at concentrations of 0.1 nM TCDD or higher. The proportion of cells expressing CD106 or CD49f decreased significantly upon treatment with TCDD. No effects on the integrin {beta}-chains CD29 and CD61 could be detected. Overall, PCB 126 induced similar changes to TCDD. In summary, TCDD and a coplanar PCB induced terminal differentiation of human TEC along with changes of integrins and other adhesion molecules. These receptors and their interplay with the extracellular matrix have key functions in the maturation of T-lymphocytes and it is plausible that their alteration would be involved in TCDD-induced immunotoxicity. (orig.)

Characterization of antigen-specific, Ia-restricted, L3T4+ cytolytic T lymphocytes and assessment of thymic influence on their self specificity

International Nuclear Information System (INIS)

Golding, H.; Munitz, T.I.; Singer, A.

1985-01-01

The goals of the present study were: (a) to generate antigen-specific L3T4+ cytolytic T lymphocytes (CTL), (b) to determine their major histocompatibility complex (MHC) restriction specificity, and (c) to assess the influence of thymic MHC determinants on their self specificity. The authors found that L3T4+ CTL specific for either trinitrophenyl (TNP)-modified self determinants or minor histocompatibility antigens could be generated from Lyt-2- responder T cells provided that the response cultures were supplemented with supernatants rich in helper factors. Such antigen-specific L3T4+ CTL were Ia-restricted by the criteria that they lysed only Ia+ target cells and that their lysis of Ia+ target cells was specifically inhibited by anti-Ia monoclonal antibodies. The relative frequency of L3T4+ pCTL was found to be only 5-10% of the total anti-TNP pCTL present in the spleens of normal mice. Finally, the authors utilized radiation bone marrow chimeras to assess the influence of the thymic haplotype on the self-Ia specificity of L3T4+ CTL. Both bulk culture and limiting dilution experiments revealed that the self-Ia specificity of L3T4+ anti-TNP CTL from F1----parent and A----B allogeneic chimeras was not markedly skewed toward the haplotype of the chimeric thymus. These results contrast with those obtained previously for L3T4+ anti-TNP Th cells and demonstrate that in the radiation bone marrow chimera model of T cell differentiation, the self specificity of Th cells but not pCTL is markedly influenced by the haplotype of the chimeric thymus

Effects of methylandrostenediol and a lymphostimulatory thymic factor (leucotrofin) on the reactivity of adrenal cortex of X-irradiated A2G mice

International Nuclear Information System (INIS)

Abraham, A.D.; Rusu, V.M.; Borsa, M.; Uray, Z.; Banu, C.

1982-01-01

Administration of methylandrostenediol alone or with Leucotrofin to whole-body irradiated A2G mice was associated with the diminuation of some enzymatic reactions in the zona fasciculata of the adrenals after 30 days on irradiation in comparison with the irradiated controls. The incorporation rate of (2- 14 C)acetate into free cholesterol and glucocorticoid, de novo synthesized in the adrenals of the protected mice, was decreased compared to the untreated animals. These data showed that late irradiation damage - caused by enhanced synthesis and secretion of catabolic corticosteroids - could be prevented by administration of anabolic steroids and lymphostimulatory thymic factors, which protect the lymphoid system from lymphotoxic agents. (author)

Effects of methylandrostenediol and a lymphostimulatory thymic factor (leucotrofin) on the reactivity of adrenal cortex of X-irradiated A2G mice

Energy Technology Data Exchange (ETDEWEB)

Abraham, A.D.; Rusu, V.M.; Borsa, M.; Uray, Z.; Banu, C. (Biological Research Centre, Cluj (Romania))

1982-03-01

Administration of methylandrostenediol alone or with Leucotrofin to whole-body irradiated A2G mice was associated with the diminuation of some enzymatic reactions in the zona fasciculata of the adrenals after 30 days on irradiation in comparison with the irradiated controls. The incorporation rate of (2-/sup 14/C)acetate into free cholesterol and glucocorticoid, de novo synthesized in the adrenals of the protected mice, was decreased compared to the untreated animals. These data showed that late irradiation damage - caused by enhanced synthesis and secretion of catabolic corticosteroids - could be prevented by administration of anabolic steroids and lymphostimulatory thymic factors, which protect the lymphoid system from lymphotoxic agents.

Plant Size and Competitive Dynamics along Nutrient Gradients.

Science.gov (United States)

Goldberg, Deborah E; Martina, Jason P; Elgersma, Kenneth J; Currie, William S

2017-08-01

Resource competition theory in plants has focused largely on resource acquisition traits that are independent of size, such as traits of individual leaves or roots or proportional allocation to different functions. However, plants also differ in maximum potential size, which could outweigh differences in module-level traits. We used a community ecosystem model called mondrian to investigate whether larger size inevitably increases competitive ability and how size interacts with nitrogen supply. Contrary to the conventional wisdom that bigger is better, we found that invader success and competitive ability are unimodal functions of maximum potential size, such that plants that are too large (or too small) are disproportionately suppressed by competition. Optimal size increases with nitrogen supply, even when plants compete for nitrogen only in a size-symmetric manner, although adding size-asymmetric competition for light does substantially increase the advantage of larger size at high nitrogen. These complex interactions of plant size and nitrogen supply lead to strong nonlinearities such that small differences in nitrogen can result in large differences in plant invasion success and the influence of competition along productivity gradients.

The mean-size dependence of the exchange narrowing in molecular J-aggregates

International Nuclear Information System (INIS)

Chen Yulu; Zhao Jijun

2011-01-01

The effect of segment-size fluctuations on exchange narrowing in a molecular J-aggregate of site-energy disordered distributions is studied using a one-dimensional Frenkel-exciton model. It is found that the segment-size disorder leads to the width of the absorption spectra deviating from the scaling law, σ 4/3 of the site-energy disordered standard deviation σ, being suitable for the system only with the site-energy disorder. In larger σ, the segment-size disorder has little influence on the linear absorption spectra. With increasing segment mean-length, the absorption line width monotonically increases, and then approaches a saturated value. By comparing a system of larger mean-length segment with a smaller one, both with the same segment-size disorder, it is found that the absorption line width of the former is broadened, and the exchange narrowing effect is reduced. The present result shows that the correlation effect can be partially maintained for the system with larger mean-length segment. -- Research Highlights: → Segment fluctuations affect the exchange narrowing of molecular J-aggregates. → The width of the absorption spectra is found to deviate from the scaling law. → Increase in segment size causes increase in the width and then saturates. → Exchange narrowing is reduced for larger mean-size segment. → Correlation can be kept partly in the larger size segment.

Zooplankton size selection relative to gill raker spacing in rainbow trout

Science.gov (United States)

Budy, P.; Haddix, T.; Schneidervin, R.

2005-01-01

Rainbow trout Oncorhynchus mykiss are one of the most widely stocked salmonids worldwide, often based on the assumption that they will effectively utilize abundant invertebrate food resources. We evaluated the potential for feeding morphology to affect prey selection by rainbow trout using a combination of laboratory feeding experiments and field observations in Flaming Gorge Reservoir, Utah-Wyoming. For rainbow trout collected from the reservoir, inter-gill raker spacing averaged 1.09 mm and there was low variation among fish overall (SD = 0.28). Ninety-seven percent of all zooplankton observed in the diets of rainbow trout collected in the reservoir were larger than the interraker spacing, while only 29% of the zooplankton found in the environment were larger than the interraker spacing. Over the size range of rainbow trout evaluated here (200-475 mm), interraker spacing increased moderately with increasing fish length; however, the size of zooplankton found in the diet did not increase with increasing fish length. In laboratory experiments, rainbow trout consumed the largest zooplankton available; the mean size of zooplankton observed in the diets was significantly larger than the mean size of zooplankton available. Electivity indices for both laboratory and field observations indicated strong selection for larger-sized zooplankton. The size threshold at which electivity switched from selection against smaller-sized zooplankton to selection for larger-sized zooplankton closely corresponded to the mean interraker spacing for both groups (???1-1.2 mm). The combination of results observed here indicates that rainbow trout morphology limits the retention of different-sized zooplankton prey and reinforces the importance of understanding how effectively rainbow trout can utilize the type and sizes of different prey available in a given system. These considerations may improve our ability to predict the potential for growth and survival of rainbow trout within and

Body Size, Fecundity, and Sexual Size Dimorphism in the Neotropical Cricket Macroanaxipha macilenta (Saussure) (Orthoptera: Gryllidae).

Science.gov (United States)

Cueva Del Castillo, R

2015-04-01

Body size is directly or indirectly correlated with fitness. Body size, which conveys maximal fitness, often differs between sexes. Sexual size dimorphism (SSD) evolves because body size tends to be related to reproductive success through different pathways in males and females. In general, female insects are larger than males, suggesting that natural selection for high female fecundity could be stronger than sexual selection in males. I assessed the role of body size and fecundity in SSD in the Neotropical cricket Macroanaxipha macilenta (Saussure). This species shows a SSD bias toward males. Females did not present a correlation between number of eggs and body size. Nonetheless, there were fluctuations in the number of eggs carried by females during the sampling period, and the size of females that were collected carrying eggs was larger than that of females collected with no eggs. Since mating induces vitellogenesis in some cricket species, differences in female body size might suggest male mate choice. Sexual selection in the body size of males of M. macilenta may possibly be stronger than the selection of female fecundity. Even so, no mating behavior was observed during the field observations, including audible male calling or courtship songs, yet males may produce ultrasonic calls due to their size. If female body size in M. macilenta is not directly related to fecundity, the lack of a correlated response to selection on female body size could represent an alternate evolutionary pathway in the evolution of body size and SSD in insects.

The effect of embryonal thymic calf extracts on neonatally thymectomized mice and on mice lethally irradiated with gamma rays

International Nuclear Information System (INIS)

Czaplicki, J.; Blonska, B.; Stec, L.

1981-01-01

The effect of embryonal thymic calf extracts (ETCE) on mice thymectomized at birth was investigated. ETCE was found to induce an increase in leukopenia and decrease in the level of serum gamma globulins; it also reduced survival time in mice. The effect of ETCE on lethally irradiated mice was also examined. Only long-term administration of ETCE prior to gamma irradiation at 750 rad prolonged the survival time of mice (40% permanent survival) as compared with irradiated controls; the leukocytes from mice retained mitotic capability. Neither long-term treatment with ETCE prior to irradiation at 1000 rad, nor short-term administration prior to 750 rad affected survival time. ETCE administered after irradiation of mice with 750 rad caused a rapid decrease in blood leukocytes and a significantly lowered survival time. (Auth.)

[Effect sizes, statistical power and sample sizes in "the Japanese Journal of Psychology"].

Science.gov (United States)

Suzukawa, Yumi; Toyoda, Hideki

2012-04-01

This study analyzed the statistical power of research studies published in the "Japanese Journal of Psychology" in 2008 and 2009. Sample effect sizes and sample statistical powers were calculated for each statistical test and analyzed with respect to the analytical methods and the fields of the studies. The results show that in the fields like perception, cognition or learning, the effect sizes were relatively large, although the sample sizes were small. At the same time, because of the small sample sizes, some meaningful effects could not be detected. In the other fields, because of the large sample sizes, meaningless effects could be detected. This implies that researchers who could not get large enough effect sizes would use larger samples to obtain significant results.

Relation between the ion size and pore size for an electric double-layer capacitor.

Science.gov (United States)

Largeot, Celine; Portet, Cristelle; Chmiola, John; Taberna, Pierre-Louis; Gogotsi, Yury; Simon, Patrice

2008-03-05

The research on electrochemical double layer capacitors (EDLC), also known as supercapacitors or ultracapacitors, is quickly expanding because their power delivery performance fills the gap between dielectric capacitors and traditional batteries. However, many fundamental questions, such as the relations between the pore size of carbon electrodes, ion size of the electrolyte, and the capacitance have not yet been fully answered. We show that the pore size leading to the maximum double-layer capacitance of a TiC-derived carbon electrode in a solvent-free ethyl-methylimmidazolium-bis(trifluoro-methane-sulfonyl)imide (EMI-TFSI) ionic liquid is roughly equal to the ion size (approximately 0.7 nm). The capacitance values of TiC-CDC produced at 500 degrees C are more than 160 F/g and 85 F/cm(3) at 60 degrees C, while standard activated carbons with larger pores and a broader pore size distribution present capacitance values lower than 100 F/g and 50 F/cm(3) in ionic liquids. A significant drop in capacitance has been observed in pores that were larger or smaller than the ion size by just an angstrom, suggesting that the pore size must be tuned with sub-angstrom accuracy when selecting a carbon/ion couple. This work suggests a general approach to EDLC design leading to the maximum energy density, which has been now proved for both solvated organic salts and solvent-free liquid electrolytes.

Visual exposure to large and small portion sizes and perceptions of portion size normality: Three experimental studies

OpenAIRE

Robinson, Eric; Oldham, Melissa; Cuckson, Imogen; Brunstrom, Jeffrey M.; Rogers, Peter J.; Hardman, Charlotte A.

2016-01-01

Portion sizes of many foods have increased in recent times. In three studies we examined the effect that repeated visual exposure to larger versus smaller food portion sizes has on perceptions of what constitutes a normal-sized food portion and measures of portion size selection. In studies 1 and 2 participants were visually exposed to images of large or small portions of spaghetti bolognese, before making evaluations about an image of an intermediate sized portion of the same food. In study ...

Mean size estimation yields left-side bias: Role of attention on perceptual averaging.

Science.gov (United States)

Li, Kuei-An; Yeh, Su-Ling

2017-11-01

The human visual system can estimate mean size of a set of items effectively; however, little is known about whether information on each visual field contributes equally to the mean size estimation. In this study, we examined whether a left-side bias (LSB)-perceptual judgment tends to depend more heavily on left visual field's inputs-affects mean size estimation. Participants were instructed to estimate the mean size of 16 spots. In half of the trials, the mean size of the spots on the left side was larger than that on the right side (the left-larger condition) and vice versa (the right-larger condition). Our results illustrated an LSB: A larger estimated mean size was found in the left-larger condition than in the right-larger condition (Experiment 1), and the LSB vanished when participants' attention was effectively cued to the right side (Experiment 2b). Furthermore, the magnitude of LSB increased with stimulus-onset asynchrony (SOA), when spots on the left side were presented earlier than the right side. In contrast, the LSB vanished and then induced a reversed effect with SOA when spots on the right side were presented earlier (Experiment 3). This study offers the first piece of evidence suggesting that LSB does have a significant influence on mean size estimation of a group of items, which is induced by a leftward attentional bias that enhances the prior entry effect on the left side.

The cavity-nest ant Temnothorax crassispinus prefers larger nests.

Science.gov (United States)

Mitrus, S

Colonies of the ant Temnothorax crassispinus inhabit mostly cavities in wood and hollow acorns. Typically in the field, nest sites that can be used by the ant are a limited resource. In a field experiment, it was investigated whether the ants prefer a specific size of nest, when different ones are available. In July 2011, a total of 160 artificial nests were placed in a beech-pine forest. Four artificial nests (pieces of wood with volume cavities, ca 415, 605, 730, and 980 mm 3 , respectively) were located on each square meter of the experimental plot. One year later, shortly before the emergence of new sexuals, the nests were collected. In July 2012, colonies inhabited more frequently bigger nests. Among queenright colonies, the ones which inhabited bigger nests had more workers. However, there was no relationship between volume of nest and number of workers for queenless colonies. Queenright colonies from bigger nests produced more sexual individuals, but there was no correlation between number of workers and sex allocation ratio, or between volume of nest and sex allocation ratio. In a laboratory experiment where ant colonies were kept in 470 and 860 mm 3 nests, larger colonies allocated more energy to produce sexual individuals. The results of this study show the selectivity of T. crassispinus ants regarding the size of nest cavity, and that the nest volume has an impact on life history parameters.

Hydroxyhydroquinone, a by-product of coffee bean roasting, increases intracellular Ca2+ concentration in rat thymic lymphocytes.

Science.gov (United States)

Kamae, Risa; Nojima, Shoko; Akiyoshi, Kenji; Setsu, Shoki; Honda, Sari; Masuda, Toshiya; Oyama, Yasuo

2017-04-01

Hydroxyhydroquinone (HHQ) is generated during coffee bean roasting. A cup of coffee contains 0.1-1.7 mg of HHQ. The actions of HHQ on mammalian DNA were examined because HHQ is a metabolite of benzene, which causes leukemia. Currently, information on the cellular actions of HHQ is limited. We examined the effects of sublethal levels of HHQ on the concentration of intracellular Ca 2+ in rat thymic lymphocytes by using a flow cytometric technique with fluorescent probes. HHQ at 10 μM or more significantly elevated intracellular Ca 2+ levels by increasing the membrane permeability of divalent cations, resulting in hyperpolarization via the activation of Ca 2+ -dependent K + channels. HHQ-induced changes in the intracellular Ca 2+ concentration and membrane potential may affect the cell functions of lymphocytes. HHQ-reduced coffee may be preferable in order to avoid the possible adverse effects of HHQ. Copyright © 2017 Elsevier Ltd. All rights reserved.

Methods for obtaining true particle size distributions from cross section measurements

Energy Technology Data Exchange (ETDEWEB)

Lord, Kristina Alyse [Iowa State Univ., Ames, IA (United States)

2013-01-01

Sectioning methods are frequently used to measure grain sizes in materials. These methods do not provide accurate grain sizes for two reasons. First, the sizes of features observed on random sections are always smaller than the true sizes of solid spherical shaped objects, as noted by Wicksell [1]. This is the case because the section very rarely passes through the center of solid spherical shaped objects randomly dispersed throughout a material. The sizes of features observed on random sections are inversely related to the distance of the center of the solid object from the section [1]. Second, on a plane section through the solid material, larger sized features are more frequently observed than smaller ones due to the larger probability for a section to come into contact with the larger sized portion of the spheres than the smaller sized portion. As a result, it is necessary to find a method that takes into account these reasons for inaccurate particle size measurements, while providing a correction factor for accurately determining true particle size measurements. I present a method for deducing true grain size distributions from those determined from specimen cross sections, either by measurement of equivalent grain diameters or linear intercepts.

RasGRP1, but not RasGRP3, is required for efficient thymic β-selection and ERK activation downstream of CXCR4.

Directory of Open Access Journals (Sweden)

Dominic P Golec

Full Text Available T cell development is a highly dynamic process that is driven by interactions between developing thymocytes and the thymic microenvironment. Upon entering the thymus, the earliest thymic progenitors, called CD4(-CD8(- 'double negative' (DN thymocytes, pass through a checkpoint termed "β-selection" before maturing into CD4(+CD8(+ 'double positive' (DP thymocytes. β-selection is an important developmental checkpoint during thymopoiesis where developing DN thymocytes that successfully express the pre-T cell receptor (TCR undergo extensive proliferation and differentiation towards the DP stage. Signals transduced through the pre-TCR, chemokine receptor CXCR4 and Notch are thought to drive β-selection. Additionally, it has long been known that ERK is activated during β-selection; however the pathways regulating ERK activation remain unknown. Here, we performed a detailed analysis of the β-selection events in mice lacking RasGRP1, RasGRP3 and RasGRP1 and 3. We report that RasGRP1 KO and RasGRP1/3 DKO deficient thymi show a partial developmental block at the early DN3 stage of development. Furthermore, DN3 thymocytes from RasGRP1 and RasGRP1/3 double knock-out thymi show significantly reduced proliferation, despite expression of the TCRβ chain. As a result of impaired β-selection, the pool of TCRβ(+ DN4 is significantly diminished, resulting in inefficient DN to DP development. Also, we report that RasGRP1 is required for ERK activation downstream of CXCR4 signaling, which we hypothesize represents a potential mechanism of RasGRP1 regulation of β-selection. Our results demonstrate that RasGRP1 is an important regulator of proliferation and differentiation at the β-selection checkpoint and functions downstream of CXCR4 to activate the Ras/MAPK pathway.

Social thermoregulation as a potential mechanism linking sociality and fitness: Barbary macaques with more social partners form larger huddles.

Science.gov (United States)

Campbell, Liz A D; Tkaczynski, Patrick J; Lehmann, Julia; Mouna, Mohamed; Majolo, Bonaventura

2018-04-17

Individuals with more or stronger social bonds experience enhanced survival and reproduction in various species, though the mechanisms mediating these effects are unclear. Social thermoregulation is a common behaviour across many species which reduces cold stress exposure, body heat loss, and homeostatic energy costs, allowing greater energetic investment in growth, reproduction, and survival, with larger aggregations providing greater benefits. If more social individuals form larger thermoregulation aggregations due to having more potential partners, this would provide a direct link between sociality and fitness. We conducted the first test of this hypothesis by studying social relationships and winter sleeping huddles in wild Barbary macaques (Macaca sylvanus), wherein individuals with more social partners experience greater probability of winter survival. Precipitation and low temperature increased huddle sizes, supporting previous research that huddle size influences thermoregulation and energetics. Huddling relationships were predicted by social (grooming) relationships. Individuals with more social partners therefore formed larger huddles, suggesting reduced energy expenditure and exposure to environmental stressors than less social individuals, potentially explaining how sociality affects survival in this population. This is the first evidence that social thermoregulation may be a direct proximate mechanism by which increased sociality enhances fitness, which may be widely applicable across taxa.

Bimodal Nanoparticle Size Distributions Produced by Laser Ablation of Microparticles in Aerosols

International Nuclear Information System (INIS)

Nichols, William T.; Malyavanatham, Gokul; Henneke, Dale E.; O'Brien, Daniel T.; Becker, Michael F.; Keto, John W.

2002-01-01

Silver nanoparticles were produced by laser ablation of a continuously flowing aerosol of microparticles in nitrogen at varying laser fluences. Transmission electron micrographs were analyzed to determine the effect of laser fluence on the nanoparticle size distribution. These distributions exhibited bimodality with a large number of particles in a mode at small sizes (3-6-nm) and a second, less populated mode at larger sizes (11-16-nm). Both modes shifted to larger sizes with increasing laser fluence, with the small size mode shifting by 35% and the larger size mode by 25% over a fluence range of 0.3-4.2-J/cm 2 . Size histograms for each mode were found to be well represented by log-normal distributions. The distribution of mass displayed a striking shift from the large to the small size mode with increasing laser fluence. These results are discussed in terms of a model of nanoparticle formation from two distinct laser-solid interactions. Initially, laser vaporization of material from the surface leads to condensation of nanoparticles in the ambient gas. Material evaporation occurs until the plasma breakdown threshold of the microparticles is reached, generating a shock wave that propagates through the remaining material. Rapid condensation of the vapor in the low-pressure region occurs behind the traveling shock wave. Measurement of particle size distributions versus gas pressure in the ablation region, as well as, versus microparticle feedstock size confirmed the assignment of the larger size mode to surface-vaporization and the smaller size mode to shock-formed nanoparticles

Sexual differences in post-hatching Saunders's gulls: size, locomotor activity, and foraging skill.

Science.gov (United States)

Yoon, Jongmin; Lee, Seung-Hee; Joo, Eun-Jin; Na, Ki-Jeong; Park, Shi-Ryong

2013-04-01

Various selection pressures induce the degree and direction of sexual size dimorphism in animals. Selection favors either larger males for contests over mates or resources, or smaller males are favored for maneuverability; whereas larger females are favored for higher fecundity, or smaller females for earlier maturation for reproduction. In the genus of Larus (seagulls), adult males are generally known to be larger in size than adult females. However, the ontogeny of sexual size dimorphism is not well understood, compared to that in adults. The present study investigates the ontogeny of sexual size dimorphism in Saunders's gulls (Larus saundersi) in captivity. We artificially incubated fresh eggs collected in Incheon, South Korea, and measured body size, locomotor activity, and foraging skill in post-hatching chicks in captivity. Our results indicated that the sexual differences in size and locomotor activity occurred with the post-hatching development. Also, larger males exhibited greater foraging skills for food acquisition than smaller females at 200 days of age. Future studies should assess how the adaptive significance of the sexual size dimorphism in juveniles is linked with sexual divergence in survival rates, intrasexual contests, or parental effort in sexes.

Size exclusion chromatography with superficially porous particles.

Science.gov (United States)

Schure, Mark R; Moran, Robert E

2017-01-13

A comparison is made using size-exclusion chromatography (SEC) of synthetic polymers between fully porous particles (FPPs) and superficially porous particles (SPPs) with similar particle diameters, pore sizes and equal flow rates. Polystyrene molecular weight standards with a mobile phase of tetrahydrofuran are utilized for all measurements conducted with standard HPLC equipment. Although it is traditionally thought that larger pore volume is thermodynamically advantageous in SEC for better separations, SPPs have kinetic advantages and these will be shown to compensate for the loss in pore volume compared to FPPs. The comparison metrics include the elution range (smaller with SPPs), the plate count (larger for SPPs), the rate production of theoretical plates (larger for SPPs) and the specific resolution (larger with FPPs). Advantages to using SPPs for SEC are discussed such that similar separations can be conducted faster using SPPs. SEC using SPPs offers similar peak capacities to that using FPPs but with faster operation. This also suggests that SEC conducted in the second dimension of a two-dimensional liquid chromatograph may benefit with reduced run time and with equivalently reduced peak width making SPPs advantageous for sampling the first dimension by the second dimension separator. Additional advantages are discussed for biomolecules along with a discussion of optimization criteria for size-based separations. Copyright © 2016 Elsevier B.V. All rights reserved.

The Evolution of Clutch Size in Hosts of Avian Brood Parasites.

Science.gov (United States)

Medina, Iliana; Langmore, Naomi E; Lanfear, Robert; Kokko, Hanna

2017-11-01

Coevolution with avian brood parasites shapes a range of traits in their hosts, including morphology, behavior, and breeding systems. Here we explore whether brood parasitism is also associated with the evolution of host clutch size. Several studies have proposed that hosts of highly virulent parasites could decrease the costs of parasitism by evolving a smaller clutch size, because hosts with smaller clutches will lose fewer progeny when their clutch is parasitized. We describe a model of the evolution of clutch size, which challenges this logic and shows instead that an increase in clutch size (or no change) should evolve in hosts. We test this prediction using a broad-scale comparative analysis to ask whether there are differences in clutch size within hosts and between hosts and nonhosts. Consistent with our model, this analysis revealed that host species do not have smaller clutches and that hosts that incur larger costs from raising a parasite lay larger clutches. We suggest that brood parasitism might be an influential factor in clutch-size evolution and could potentially select for the evolution of larger clutches in host species.

The Dynamical Imprint of Lost Protoplanets on the Trans-Neptunian Populations, and Limits on the Primordial Size Distribution of Trans-Neptunian Objects at Pluto and Larger Sizes.

Science.gov (United States)

Shannon, Andrew Brian; Dawson, Rebekah

2018-04-01

Planet formation remains a poorly understood process, in part because of our limited access to the intermediate phases of planetesimal and protoplanet growth. Today, the vast majority of the accessible remaining planetesimals and protoplanets reside within the Hot Trans-Neptunian Object population. This population has been depleted by 99% - 99.9% over the course of the Solar system's history, and as such the present day size-number distribution may be incomplete at the large size end. We show that such lost protoplanets would have left signatures in the dynamics of the present-day Trans-Neptunian Populations, and their primordial number can thus be statistically limited by considering the survival of ultra-wide binary TNOs, the Cold Classical Kuiper belt, and the resonant populations. We compare those limits to the predicted size-number distribution of various planetesimal and proto-planet growth models.

A model for optimal offspring size in fish, including live-bearing and parental effects.

Science.gov (United States)

Jørgensen, Christian; Auer, Sonya K; Reznick, David N

2011-05-01

Since Smith and Fretwell's seminal article in 1974 on the optimal offspring size, most theory has assumed a trade-off between offspring number and offspring fitness, where larger offspring have better survival or fitness, but with diminishing returns. In this article, we use two ubiquitous biological mechanisms to derive the shape of this trade-off: the offspring's growth rate combined with its size-dependent mortality (predation). For a large parameter region, we obtain the same sigmoid relationship between offspring size and offspring survival as Smith and Fretwell, but we also identify parameter regions where the optimal offspring size is as small or as large as possible. With increasing growth rate, the optimal offspring size is smaller. We then integrate our model with strategies of parental care. Egg guarding that reduces egg mortality favors smaller or larger offspring, depending on how mortality scales with size. For live-bearers, the survival of offspring to birth is a function of maternal survival; if the mother's survival increases with her size, then the model predicts that larger mothers should produce larger offspring. When using parameters for Trinidadian guppies Poecilia reticulata, differences in both growth and size-dependent predation are required to predict observed differences in offspring size between wild populations from high- and low-predation environments.

Are larger and/or more symmetrical Drosophila melanogaster (Diptera, Drosophilidae males more successful in matings in nature?

Directory of Open Access Journals (Sweden)

Sofija Pavković-Lučić

Full Text Available Are larger and/or more symmetrical Drosophila melanogaster (Diptera, Drosophilidae males more successful in matings in nature? Sexual selection in Drosophila melanogaster, related to body size and fluctuating asymmetry in wing length and number of sex comb teeth in males, was tested in natural conditions. Males collected in copula were significantly larger than those collected as a single, while no difference in mean number of sex comb teeth between copulating and single males was observed. On the other hand, single males had greater asymmetry both for wing length and number of sex comb teeth than their mating counterparts. It looks like that symmetry of these bilateral traits also may play a role in sexual selection in this dipteran species in nature.

Eye Size, Fovea, and Foraging Ecology in Accipitriform Raptors.

Science.gov (United States)

Potier, Simon; Mitkus, Mindaugas; Bonadonna, Francesco; Duriez, Olivier; Isard, Pierre-François; Dulaurent, Thomas; Mentek, Marielle; Kelber, Almut

2017-01-01

Birds with larger eyes are predicted to have higher spatial resolution because of their larger retinal image. Raptors are well known for their acute vision, mediated by their deep central fovea. Because foraging strategies may demand specific visual adaptations, eye size and fovea may differ between species with different foraging ecology. We tested whether predators (actively hunting mobile prey) and carrion eaters (eating dead prey) from the order Accipitriformes differ in eye size, foveal depth, and retinal thickness using spectral domain optical coherence tomography and comparative phylogenetic methods. We found that (1) all studied predators (except one) had a central and a temporal fovea, but all carrion eaters had only the central fovea; (2) eye size scaled with body mass both in predators and carrion eaters; (3) predators had larger eyes relative to body mass and a thicker retina at the edge of the fovea than carrion eaters, but there was no difference in the depth of the central fovea between the groups. Finally, we found that (4) larger eyes generally had a deeper central fovea. These results suggest that the visual system of raptors within the order Accipitriformes may be highly adapted to the foraging strategy, except for the foveal depth, which seems mostly dependent upon the eye size. © 2017 S. Karger AG, Basel.

Smart moves: effects of relative brain size on establishment success of invasive amphibians and reptiles.

Science.gov (United States)

Amiel, Joshua J; Tingley, Reid; Shine, Richard

2011-04-06

Brain size relative to body size varies considerably among animals, but the ecological consequences of that variation remain poorly understood. Plausibly, larger brains confer increased behavioural flexibility, and an ability to respond to novel challenges. In keeping with that hypothesis, successful invasive species of birds and mammals that flourish after translocation to a new area tend to have larger brains than do unsuccessful invaders. We found the same pattern in ectothermic terrestrial vertebrates. Brain size relative to body size was larger in species of amphibians and reptiles reported to be successful invaders, compared to species that failed to thrive after translocation to new sites. This pattern was found in six of seven global biogeographic realms; the exception (where relatively larger brains did not facilitate invasion success) was Australasia. Establishment success was also higher in amphibian and reptile families with larger relative brain sizes. Future work could usefully explore whether invasion success is differentially associated with enlargement of specific parts of the brain (as predicted by the functional role of the forebrain in promoting behavioural flexibility), or with a general size increase (suggesting that invasion success is facilitated by enhanced perceptual and motor skills, as well as cognitive ability).

Children's accuracy of portion size estimation using digital food images: effects of interface design and size of image on computer screen.

Science.gov (United States)

Baranowski, Tom; Baranowski, Janice C; Watson, Kathleen B; Martin, Shelby; Beltran, Alicia; Islam, Noemi; Dadabhoy, Hafza; Adame, Su-heyla; Cullen, Karen; Thompson, Debbe; Buday, Richard; Subar, Amy

2011-03-01

To test the effect of image size and presence of size cues on the accuracy of portion size estimation by children. Children were randomly assigned to seeing images with or without food size cues (utensils and checked tablecloth) and were presented with sixteen food models (foods commonly eaten by children) in varying portion sizes, one at a time. They estimated each food model's portion size by selecting a digital food image. The same food images were presented in two ways: (i) as small, graduated portion size images all on one screen or (ii) by scrolling across large, graduated portion size images, one per sequential screen. Laboratory-based with computer and food models. Volunteer multi-ethnic sample of 120 children, equally distributed by gender and ages (8 to 13 years) in 2008-2009. Average percentage of correctly classified foods was 60·3 %. There were no differences in accuracy by any design factor or demographic characteristic. Multiple small pictures on the screen at once took half the time to estimate portion size compared with scrolling through large pictures. Larger pictures had more overestimation of size. Multiple images of successively larger portion sizes of a food on one computer screen facilitated quicker portion size responses with no decrease in accuracy. This is the method of choice for portion size estimation on a computer.

The correlation between supermarket size and national obesity prevalence.

Science.gov (United States)

Cameron, Adrian J; Waterlander, Wilma E; Svastisalee, Chalida M

2014-01-01

Supermarkets provide healthy and affordable food options while simultaneously heavily promoting energy-dense, nutrient-poor foods and drinks. Store size may impact body weight via multiple mechanisms. Large stores encourage purchasing of more food in a single visit, and in larger packages. In addition they provide greater product choice (usually at lower prices) and allow greater exposure to foods of all types. These characteristics may promote purchasing and consumption. Our objective was to assess the relationship between supermarket size and obesity, which has rarely been assessed. Data on supermarket size (measured as total aisle length in metres) was from 170 stores in eight developed countries with Western-style diets. Data for national obesity prevalence was obtained from the UK National Obesity Observatory. We found a strong correlation between average store size and national obesity prevalence (r = 0.96). Explanations for the association between store size and national obesity prevalence may include larger and less frequent shopping trips and greater choice and exposure to foods in countries with larger stores. Large supermarkets may represent a food system that focuses on quantity ahead of quality and therefore may be an important and novel environmental indicator of a pattern of behaviour that encourages obesity.

Imaging samples larger than the field of view: the SLS experience

Science.gov (United States)

Vogiatzis Oikonomidis, Ioannis; Lovric, Goran; Cremona, Tiziana P.; Arcadu, Filippo; Patera, Alessandra; Schittny, Johannes C.; Stampanoni, Marco

2017-06-01

Volumetric datasets with micrometer spatial and sub-second temporal resolutions are nowadays routinely acquired using synchrotron X-ray tomographic microscopy (SRXTM). Although SRXTM technology allows the examination of multiple samples with short scan times, many specimens are larger than the field-of-view (FOV) provided by the detector. The extension of the FOV in the direction perpendicular to the rotation axis remains non-trivial. We present a method that can efficiently increase the FOV merging volumetric datasets obtained by region-of-interest tomographies in different 3D positions of the sample with a minimal amount of artefacts and with the ability to handle large amounts of data. The method has been successfully applied for the three-dimensional imaging of a small number of mouse lung acini of intact animals, where pixel sizes down to the micrometer range and short exposure times are required.

Identification of neurotensin-related peptides in human thymic epithelial cell membranes and relationship with major histocompatibility complex class I molecules.

Science.gov (United States)

Vanneste, Y; Thome, A N; Vandersmissen, E; Charlet, C; Franchimont, D; Martens, H; Lhiaubet, A M; Schimpff, R M; Rostène, W; Geenen, V

1997-06-01

This study shows the expression at the cell surface of human thymic epithelial cells (TEC) of a neurotensin (NT)-like immunoreactivity. NT radio-immunoassay (RIA) revealed that cultured human TEC contain +/-5 ng immunoreactive (ir) NT/10(6) cells, of which 5% is associated with plasma cell membranes. HPLC analysis of NT-ir present in human TEC showed a major peak of NT-ir corresponding to NT1-13. NT-ir was not detected in the supernatant of human TEC cultures. Using an affinity column prepared with a anti-MHC class I monoclonal antibody, NT-ir-related peptides were retained on the column and eluted together with MHC class I-related proteins. According to the elution time on HPLC of these peptides, they correspond to intact NT1-13, as well as to smaller fragments of NT1-13.

Do class size effects differ across grades?

DEFF Research Database (Denmark)

Nandrup, Anne Brink

size cap that creates exogenous variation in class sizes. Significant (albeit modest) negative effects of class size increases are found for children on primary school levels. The effects on math abilities are statistically different across primary and secondary school. Larger classes do not affect......This paper contributes to the class size literature by analyzing whether short-run class size effects are constant across grade levels in compulsory school. Results are based on administrative data on all pupils enroled in Danish public schools. Identification is based on a government-imposed class...

Country size, currency unions, and international asset returns

OpenAIRE

Hassan, Tarek A.

2015-01-01

The fact that economies differ in size has important implications for international asset returns. I solve for the spread on international bonds and stocks in an endowment economy with complete asset markets and non-traded goods. The model predicts that larger countries have lower real interest rates because their bonds provide insurance against shocks that affect a larger fraction of the world economy. Larger countries' bonds must therefore pay lower excess returns in equilibrium and uncover...

Smart Moves: Effects of Relative Brain Size on Establishment Success of Invasive Amphibians and Reptiles

Science.gov (United States)

Amiel, Joshua J.; Tingley, Reid; Shine, Richard

2011-01-01

Brain size relative to body size varies considerably among animals, but the ecological consequences of that variation remain poorly understood. Plausibly, larger brains confer increased behavioural flexibility, and an ability to respond to novel challenges. In keeping with that hypothesis, successful invasive species of birds and mammals that flourish after translocation to a new area tend to have larger brains than do unsuccessful invaders. We found the same pattern in ectothermic terrestrial vertebrates. Brain size relative to body size was larger in species of amphibians and reptiles reported to be successful invaders, compared to species that failed to thrive after translocation to new sites. This pattern was found in six of seven global biogeographic realms; the exception (where relatively larger brains did not facilitate invasion success) was Australasia. Establishment success was also higher in amphibian and reptile families with larger relative brain sizes. Future work could usefully explore whether invasion success is differentially associated with enlargement of specific parts of the brain (as predicted by the functional role of the forebrain in promoting behavioural flexibility), or with a general size increase (suggesting that invasion success is facilitated by enhanced perceptual and motor skills, as well as cognitive ability). PMID:21494328

Smart moves: effects of relative brain size on establishment success of invasive amphibians and reptiles.

Directory of Open Access Journals (Sweden)

Joshua J Amiel

2011-04-01

Full Text Available Brain size relative to body size varies considerably among animals, but the ecological consequences of that variation remain poorly understood. Plausibly, larger brains confer increased behavioural flexibility, and an ability to respond to novel challenges. In keeping with that hypothesis, successful invasive species of birds and mammals that flourish after translocation to a new area tend to have larger brains than do unsuccessful invaders. We found the same pattern in ectothermic terrestrial vertebrates. Brain size relative to body size was larger in species of amphibians and reptiles reported to be successful invaders, compared to species that failed to thrive after translocation to new sites. This pattern was found in six of seven global biogeographic realms; the exception (where relatively larger brains did not facilitate invasion success was Australasia. Establishment success was also higher in amphibian and reptile families with larger relative brain sizes. Future work could usefully explore whether invasion success is differentially associated with enlargement of specific parts of the brain (as predicted by the functional role of the forebrain in promoting behavioural flexibility, or with a general size increase (suggesting that invasion success is facilitated by enhanced perceptual and motor skills, as well as cognitive ability.

Promotion of alternative-sized personal protective equipment.

Science.gov (United States)

Flynn, Michael A; Keller, Brenna; DeLaney, Sheli C

2017-12-01

With more diversity in the workforce, companies are producing PPE such as hard hats, safety glasses, coveralls, foot protection, and safety harnesses for a larger range of body shapes and sizes. However, gray literature reports suggest that barriers exist to getting alternate sized PPE from the manufacturer to the workers who need it. The purpose of this study is to determine the extent to which alternative-sized PPE is marketed. A web-based review of seven major manufacturers of PPE was conducted to determine: (a) whether or not they offer alternative-sized products, (b) if these products are clearly labeled, and (c) if images used to display PPE are representative of a diverse workforce. Of the seven PPE manufacturers investigated, six had at least one product that was marketed as gender and/or size alternatives however, alternative sizes were more common for larger body types. Alternative-sized products rarely included size charts, and the models used to display PPE were overwhelmingly white males of average size. Despite the growing availability of alternative-sized PPE, it can be difficult to find these products, which suggests that they are rarely promoted or labeled as alternative-sized. Our study indicates that companies should expand their product lines and more aggressively market and promote these items. Guidance on how to properly fit their products would also be extremely helpful to the end-user. Manufacturers could improve the availability of alternative-sized PPE and increase their promotion of these products on their websites and in their catalogs. Individual companies and safety professionals may assist in this process by demonstrating demand for alternative-sized PPE. Published by Elsevier Ltd.

Size determinations of colloidal fat emulsions

DEFF Research Database (Denmark)

Kuntsche, Judith; Klaus, Katrin; Steiniger, Frank

2009-01-01

Size and size distributions of colloidal dispersions are of crucial importance for their performance and safety. In the present study, commercially available fat emulsions (Lipofundin N, Lipofundin MCT and Lipidem) were analyzed by photon correlation spectroscopy, laser diffraction with adequate...... was checked with mixtures of monodisperse polystyrene nanospheres. In addition, the ultrastructure of Lipofundin N and Lipofundin MCT was investigated by cryo-electron microscopy. All different particle sizing methods gave different mean sizes and size distributions but overall, results were in reasonable...... agreement. By all methods, a larger mean droplet size (between 350 and 400 nm) as well as a broader distribution was measured for Lipofundin N compared to Lipofundin MCT and Lipidem (mean droplet size between about 280 and 320 nm). Size distributions of Lipofundin MCT and Lipidem were very similar...

An intracellular adrenomedullin system reduces IL-6 release via a NF-kB-mediated, cAMP-independent transcriptional mechanism in rat thymic epithelial cells.

Science.gov (United States)

Castellani, Giulia; Paliuri, Giovanna; Orso, Genny; Paccagnella, Nicola; D'Amore, Claudio; Facci, Laura; Cima, Francesca; Caicci, Federico; Palatini, Pietro; Bova, Sergio; De Martin, Sara

2016-12-01

Thymic epithelial cells (TECs) play a key role in the regulation of central immune tolerance by expressing autoantigens and eliminating self-reactive T cells. In a previous paper we reported that adrenomedullin (ADM) and its co-receptor protein RAMP2 are located intracellularly in newborn human thymic epithelial cells (TECs). This work has two main aims: (1) to examine the cellular localization of ADM and its receptor in TECs of adult Wistar rats to validate this animal model for the study of the ADM system and its function(s) in thymus; (2) to investigate the potential modulating effect of ADM on the NF-kB pathway, which is involved through the production of cytokines such as IL-6, in the maturation of T-lymphocytes and immunological tolerance. Our results show that, similarly to human newborn TECs, ADM is localized to the cytoplasm of adult rat TECs, and RAMP2 is expressed in the nucleus but not in the plasma membrane. Pretreatment of TECs for 4h with ADM significantly reduced lipopolysaccharide (LPS)-induced release of IL-6 (PkB, while doubled the expression of IkBα (PkB nuclear translocation. These effects were not mediated by activation of the cAMP pathway, a signalling cascade that is rapidly activated by ADM in cells that express plasma membrane RAMP2, but were the consequence of a reduction in the transcription of p65 (PkB genes transcription through an interaction with a receptor localized to the nucleus. This may partly explain the protective effects of ADM in autoimmune diseases and points to the ADM system of TECs as a novel potential target for immunomodulating drugs. Copyright © 2016 Elsevier Ltd. All rights reserved.

Diffusion of two-dimensional epitaxial clusters on metal (100) surfaces: Facile versus nucleation-mediated behavior and their merging for larger sizes

Science.gov (United States)

Lai, King C.; Liu, Da-Jiang; Evans, James W.

2017-12-01

For diffusion of two-dimensional homoepitaxial clusters of N atoms on metal (100) surfaces mediated by edge atom hopping, macroscale continuum theory suggests that the diffusion coefficient scales like DN˜ N-β with β =3 /2 . However, we find quite different and diverse behavior in multiple size regimes. These include: (i) facile diffusion for small sizes N mediated diffusion with small β 2 for N =Np+1 and Np+2 also for moderate sizes 9 ≤N ≤O (102) ; (iv) merging of the above distinct branches and subsequent anomalous scaling with 1 ≲β analysis must account for a strong enhancement of diffusivity for short time increments due to back correlation in the cluster motion. Further understanding of this enhancement, of anomalous size scaling behavior, and of the merging of various branches, is facilitated by combinatorial analysis of the number of the ground-state and low-lying excited state cluster configurations, and also of kink populations.

Sauropod dinosaurs evolved moderately sized genomes unrelated to body size.

Science.gov (United States)

Organ, Chris L; Brusatte, Stephen L; Stein, Koen

2009-12-22

Sauropodomorph dinosaurs include the largest land animals to have ever lived, some reaching up to 10 times the mass of an African elephant. Despite their status defining the upper range for body size in land animals, it remains unknown whether sauropodomorphs evolved larger-sized genomes than non-avian theropods, their sister taxon, or whether a relationship exists between genome size and body size in dinosaurs, two questions critical for understanding broad patterns of genome evolution in dinosaurs. Here we report inferences of genome size for 10 sauropodomorph taxa. The estimates are derived from a Bayesian phylogenetic generalized least squares approach that generates posterior distributions of regression models relating genome size to osteocyte lacunae volume in extant tetrapods. We estimate that the average genome size of sauropodomorphs was 2.02 pg (range of species means: 1.77-2.21 pg), a value in the upper range of extant birds (mean = 1.42 pg, range: 0.97-2.16 pg) and near the average for extant non-avian reptiles (mean = 2.24 pg, range: 1.05-5.44 pg). The results suggest that the variation in size and architecture of genomes in extinct dinosaurs was lower than the variation found in mammals. A substantial difference in genome size separates the two major clades within dinosaurs, Ornithischia (large genomes) and Saurischia (moderate to small genomes). We find no relationship between body size and estimated genome size in extinct dinosaurs, which suggests that neutral forces did not dominate the evolution of genome size in this group.

Multiple Functions of the New Cytokine-Based Antimicrobial Peptide Thymic Stromal Lymphopoietin (TSLP

Directory of Open Access Journals (Sweden)

Louise Bjerkan

2016-07-01

Full Text Available Thymic stromal lymphopoietin (TSLP is a pleiotropic cytokine, hitherto mostly known to be involved in inflammatory responses and immunoregulation. The human tslp gene gives rise to two transcription and translation variants: a long form (lfTSLP that is induced by inflammation, and a short, constitutively-expressed form (sfTSLP, that appears to be downregulated by inflammation. The TSLP forms can be produced by a number of cell types, including epithelial and dendritic cells (DCs. lfTSLP can activate mast cells, DCs, and T cells through binding to the lfTSLP receptor (TSLPR and has a pro-inflammatory function. In contrast, sfTSLP inhibits cytokine secretion of DCs, but the receptor mediating this effect is unknown. Our recent studies have demonstrated that both forms of TSLP display potent antimicrobial activity, exceeding that of many other known antimicrobial peptides (AMPs, with sfTSLP having the strongest effect. The AMP activity is primarily mediated by the C-terminal region of the protein and is localized within a 34-mer peptide (MKK34 that spans the C-terminal α-helical region in TSLP. Fluorescent studies of peptide-treated bacteria, electron microscopy, and liposome leakage models showed that MKK34 exerted membrane-disrupting effects comparable to those of LL-37. Expression of TSLP in skin, oral mucosa, salivary glands, and intestine is part of the defense barrier that aids in the control of both commensal and pathogenic microbes.

Size exclusion chromatography for semipreparative scale separation of Au38(SR)24 and Au40(SR)24 and larger clusters.

Science.gov (United States)

Knoppe, Stefan; Boudon, Julien; Dolamic, Igor; Dass, Amala; Bürgi, Thomas

2011-07-01

Size exclusion chromatography (SEC) on a semipreparative scale (10 mg and more) was used to size-select ultrasmall gold nanoclusters (<2 nm) from polydisperse mixtures. In particular, the ubiquitous byproducts of the etching process toward Au(38)(SR)(24) (SR, thiolate) clusters were separated and gained in high monodispersity (based on mass spectrometry). The isolated fractions were characterized by UV-vis spectroscopy, MALDI mass spectrometry, HPLC, and electron microscopy. Most notably, the separation of Au(38)(SR)(24) and Au(40)(SR)(24) clusters is demonstrated.

Larger fig wasps are more careful about which figs to enter--with good reason.

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Liu, Cong; Yang, Da-Rong; Compton, Stephen G; Peng, Yan-Qiong

2013-01-01

Floral longevity reflects a balance between gains in pollinator visitation and the costs of flower maintenance. Because rewards to pollinators change over time, older flowers may be less attractive, reducing the value of extended longevity. Un-pollinated figs, the inflorescences of Ficus species, can remain receptive for long periods, but figs that are older when entered by their host-specific fig wasp pollinators produce fewer seeds and fig wasp offspring. Our field experiments with Ficushispida, a dioecious fig tree, examined how the length of time that receptive figs have remained un-pollinated influences the behaviour and reproductive success of its short-lived fig wasp pollinator, Ceratosolensolmsi marchali. The results were consistent in three different seasons, and on male and female trees, although receptivity was greatly extended during colder months. Pollinators took longer to find the ostioles of older figs, and longer to penetrate them. They also became increasingly unwilling to enter figs as they aged, and increasing numbers of the wasps became trapped in the ostiolar bracts. Larger individuals were particularly unwilling to enter older figs, resulting in older figs being pollinated by smaller wasps. On female trees, where figs produce only seeds, seed production declined rapidly with fig age. On male trees, the numbers and size of fig wasp offspring declined, and a higher proportion were male. Older male figs are harder to enter, especially for larger individuals, and offer poorer quality oviposition opportunities. This study opens an interesting new perspective on the coevolution of figs and their pollinators, especially factors influencing pollinator body size and emphasises the subtleties of interactions between mutualists.

Thymic versus induced regulatory T cells – who regulates the regulators?

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Giovanni Antonio Maria Povoleri

2013-06-01

Full Text Available Physiological health must balance immunological responsiveness against foreign pathogens with tolerance towards self-components and commensals. Disruption of this balance causes autoimmune diseases/chronic inflammation, in case of excessive immune responses, and persistent infection/immunodeficiency if regulatory components are overactive. This homeostasis occurs at two different levels: at a resting state to prevent autoimmune disease, as autoreactive effector T-cells (Teffs are only partially deleted in the thymus, and during inflammation to prevent excessive tissue injury, contract the immune response and enable tissue repair. Adaptive immune cells with regulatory function (regulatory T-cells are essential to control Teffs. Two sets of regulatory T cell are required to achieve the desired control: those emerging de novo from embryonic/neonatal thymus (thymic or tTregs, whose function is to control autoreactive Teffs to prevent autoimmune diseases, and those induced in the periphery (peripheral or pTregs to acquire regulatory phenotype in response to pathogens/inflammation. The differentiation mechanisms of these cells determine their commitment to lineage and plasticity towards other phenotypes. tTregs, expressing high levels of IL-2 receptor alpha chain (CD25, and the transcription factor Foxp3, are the most important, since mutations or deletions in these genes cause fatal autoimmune diseases in both mice and men. In the periphery, instead, Foxp3+ pTregs can be induced from naïve precursors in response to environmental signals. Here, we discuss molecular signatures and induction processes, mechanisms and sites of action, lineage stability and differentiating characteristics of both Foxp3+ and Foxp3- populations of regulatory T cells, derived from the thymus or induced peripherally. We relate these predicates to programs of cell-based therapy for the treatment of autoimmune diseases and induction of tolerance to transplants.

Size-dependent magnetic properties of branchlike nickel oxide nanocrystals

Directory of Open Access Journals (Sweden)

Dan Liu

2017-01-01

Full Text Available Branchlike nickel oxide nanocrystals with narrow size distribution are obtained by a solution growth method. The size-dependent of magnetic properties of the nickel oxides were investigated. The results of magnetic characterization indicate that the NiO nanocrystals with size below 12.8 nm show very weak ferromagnetic state at room temperature due to the uncompensated spins. Both of the average blocking temperature (Tb and the irreversible temperature (Tirr increase with the increase of nanoparticle sizes, while both the remnant magnetization and the coercivity at 300 K increase with the decrease of the particle sizes. Moreover, the disappearance of two-magnon (2M band and redshift of one-phonon longitudinal (1LO and two-phonon LO in vibrational properties due to size reduction are observed. Compared to the one with the spherical morphological, it is also found that nano-structured nickel oxides with the branchlike morphology have larger remnant magnetization and the coercivity at 5 K due to their larger surface-to-volume ratio and greater degree of broken symmetry at the surface or the higher proportion of broken bonds.

Sizing of intergranular stress corrosion cracking using low frequency ultrasound

International Nuclear Information System (INIS)

Fuller, M.D.; Avioli, M.J.; Rose, J.L.

1985-01-01

Based upon the work thus far accomplished on low frequency sizing, the following conclusions can be drawn: the potential of low frequency ultrasound for the sizing of IGSCC seams encouraging as demonstrated in this work. If minimal walking is expected, larger values of crack height/wavelength ratios should not affect the reliability of estimates; notch data points out the validity of signal amplitude for sizing. With care in frequency consideration, the technique can be extended to cracks; when wavelength is greater than flaw size, importance of orientation and reflector shape diminishes although less so for deeper cracks; when beam profile is larger than the defect size, echo amplitude is proportional to defect area when using shear wave probes and corner reflectors; other factors, in addition to crack size, affect signal amplitude. Reference data to compensate for depth and material (HAZ) is a must; additional crack samples should be studied in order to further develop and characterize the use of low frequency ultrasonics

Stable Size Distribution of Amyloid Plaques Over the Course of Alzheimer Disease

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Serrano-Pozo, Alberto; Mielke, Matthew L.; Muzitansky, Alona; Gómez-Isla, Teresa; Growdon, John H.; Bacskai, Brian J.; Betensky, Rebecca A.; Frosch, Matthew P.; Hyman, Bradley T.

2012-01-01

Amyloid-β plaques are a key pathological feature of Alzheimer disease (AD), but whether plaque sizes increase or stabilize over the course of AD is unknown. We measured the size distribution of total immunoreactive (10D5-positive) and dense-core (Thioflavine-S-positive) plaques in the temporal neocortex of a large group of AD and plaque-bearing age-matched non-demented subjects to test the hypothesis that amyloid plaques continue to grow along with the progression of the disease. The size of amyloid-β (10D5)-positive plaques did not differ between groups whereas dense-core plaques from the AD group were slightly larger than those in the non-demented group (~25%–30%, p = 0.01). Within the AD group, dense-core plaque size did not independently correlate with duration of clinical disease (from 4 to 21 years, p = 0.68), whereas 10D5-positive plaque size correlated negatively with disease duration (p = 0.01). By contrast, an earlier age of symptom onset strongly predicted a larger postmortem plaque size; this effect was independent of disease duration and the presence of the APOEε4 allele (p = 0.0001). We conclude that plaques vary in size among patients, with larger size distributions correlating with an earlier age of onset, but plaques do not substantially increase in size over the clinical course of the disease. PMID:22805771

Effects of habitat features on size-biased predation on salmon by bears.

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Andersson, Luke C; Reynolds, John D

2017-05-01

Predators can drive trait divergence among populations of prey by imposing differential selection on prey traits. Habitat characteristics can mediate predator selectivity by providing refuge for prey. We quantified the effects of stream characteristics on biases in the sizes of spawning salmon caught by bears (Ursus arctos and U. americanus) on the central coast of British Columbia, Canada by measuring size-biased predation on spawning chum (Oncorhynchus keta) and pink (O. gorbuscha) salmon in 12 streams with varying habitat characteristics. We tested the hypotheses that bears would catch larger than average salmon (size-biased predation) and that this bias toward larger fish would be higher in streams that provide less protection to spawning salmon from predation (e.g., less pools, wood, undercut banks). We then we tested for how such size biases in turn translate into differences among populations in the sizes of the fish. Bears caught larger-than-average salmon as the spawning season progressed and as predicted, this was most pronounced in streams with fewer refugia for the fish (i.e., wood and undercut banks). Salmon were marginally smaller in streams with more pronounced size-biased predation but this predictor was less reliable than physical characteristics of streams, with larger fish in wider, deeper streams. These results support the hypothesis that selective forces imposed by predators can be mediated by habitat characteristics, with potential consequences for physical traits of prey.

Temporal profile of body temperature in acute ischemic stroke: relation to infarct size and outcome.

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Geurts, Marjolein; Scheijmans, Féline E V; van Seeters, Tom; Biessels, Geert J; Kappelle, L Jaap; Velthuis, Birgitta K; van der Worp, H Bart

2016-11-21

High body temperatures after ischemic stroke have been associated with larger infarct size, but the temporal profile of this relation is unknown. We assess the relation between temporal profile of body temperature and infarct size and functional outcome in patients with acute ischemic stroke. In 419 patients with acute ischemic stroke we assessed the relation between body temperature on admission and during the first 3 days with both infarct size and functional outcome. Infarct size was measured in milliliters on CT or MRI after 3 days. Poor functional outcome was defined as a modified Rankin Scale score ≥3 at 3 months. Body temperature on admission was not associated with infarct size or poor outcome in adjusted analyses. By contrast, each additional 1.0 °C in body temperature on day 1 was associated with 0.31 ml larger infarct size (95% confidence interval (CI) 0.04-0.59), on day 2 with 1.13 ml larger infarct size(95% CI, 0.83-1.43), and on day 3 with 0.80 ml larger infarct size (95% CI, 0.48-1.12), in adjusted linear regression analyses. Higher peak body temperatures on days two and three were also associated with poor outcome (adjusted relative risks per additional 1.0 °C in body temperature, 1.52 (95% CI, 1.17-1.99) and 1.47 (95% CI, 1.22-1.77), respectively). Higher peak body temperatures during the first days after ischemic stroke, rather than on admission, are associated with larger infarct size and poor functional outcome. This suggests that prevention of high temperatures may improve outcome if continued for at least 3 days.

Indoor radon progeny aerosol size measurements in urban, suburban, and rural regions

International Nuclear Information System (INIS)

Tu, K.W.; Knutson, E.O.; George, A.C.

1991-01-01

By using direct and indirect methods, the authors conducted size distribution measurements of radon progeny particles in a variety of indoor environments in urban, suburban, and rural areas. The radon progeny particle size distribution owing to indoor activities has two definable source categories: (1) gas combustion from stoves and kerosene heaters - particles were found to be smaller than 0.1 μm in diameter, mostly in the range 0.02-0.08 μm; and (2) cigarette smoking and food frying - particles were found to be larger, in the size range 0.1-0.2 μm. The radon progeny particle size distribution, without significant indoor activities, such as cooking, was found to be larger in rural areas than in urban or suburban areas. The modal diameters of the size spectra in the rural areas were two to three times larger than those in urban or suburban areas, around 0.3-0.4 bs. 0.1-0.2 μm. Results obtained by applying the attachment theory to the measured number-weighted size spectra from an electrical aerosol size analyzer support this finding. These results, if confirmed by more extensive studies, will be useful for the assessment of the risk from the inhalation of radon progeny in various indoor environments

Synthesis and electrochemical properties of different sizes of the CuO particles

International Nuclear Information System (INIS)

Zhang Xiaojun; Zhang Dongen; Ni Xiaomin; Song Jimei; Zheng Huagui

2008-01-01

Well-dispersed cupric oxide (CuO) nanoparticles with the size from 10 to 100 nm were successfully synthesized by thermal decomposition of CuC 2 O 4 precursor at 400 deg. C. The prepared CuO nanoparticles of different sizes used as anode materials for Li ion battery all exhibit high electrochemical capacity at the first discharge. However, with the particles size changing, an interesting phenomenon appears. That is, the larger size of the particles is, the discharge capacity of the first time smaller is, while that of the second time is larger. At the same time, the mechanism of the above phenomenon is discussed in this paper. Surprisingly, we have synthesized the copper nanoparticles with different sizes by the CuO of different sizes as the electrodes

Normal kidney size and renal cortical thickness of the Korean adults

International Nuclear Information System (INIS)

Chung, Hee Kyung; Hahm, Chang Kok

1974-01-01

1. The kidney size and cortical thickness were measured from intravenous pyelograms of healthy Korean adults of 250 males and 250 females. 2. The measured size and cortical thickness of kidney were following figure (mm). 3. The size of kidney of male is a little larger than female both in vertical length and horizontal width. 4. The renal cortical thickness were not significant in differences between male and female, right and left, in each poles. 5. In the study of distribution of length differences between pairs of kidneys in our series, the length of right kidney is larger in 18.6%, and width in 27.2%. 6. Comparative study is carried out measuring the length of first lumbar vertebral bodies including 4 intervertebral spaces. 7. The site of kidney is larger in the group of greater length of vertebral height. 8. The renal cortical thickness have no significant differences in according to the differences of length of vertebral height, in each poles. 9. Comparing with the western authors, the kidney size of the Korean adult is not smaller than western

Evolution of body size in Galapagos marine iguanas.

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Wikelski, Martin

2005-10-07

Body size is one of the most important traits of organisms and allows predictions of an individual's morphology, physiology, behaviour and life history. However, explaining the evolution of complex traits such as body size is difficult because a plethora of other traits influence body size. Here I review what we know about the evolution of body size in a group of island reptiles and try to generalize about the mechanisms that shape body size. Galapagos marine iguanas occupy all 13 larger islands in this Pacific archipelago and have maximum island body weights between 900 and 12 000g. The distribution of body sizes does not match mitochondrial clades, indicating that body size evolves independently of genetic relatedness. Marine iguanas lack intra- and inter-specific food competition and predators are not size-specific, discounting these factors as selective agents influencing body size. Instead I hypothesize that body size reflects the trade-offs between sexual and natural selection. We found that sexual selection continuously favours larger body sizes. Large males establish display territories and some gain over-proportional reproductive success in the iguanas' mating aggregations. Females select males based on size and activity and are thus responsible for the observed mating skew. However, large individuals are strongly selected against during El Niño-related famines when dietary algae disappear from the intertidal foraging areas. We showed that differences in algae sward ('pasture') heights and thermal constraints on large size are causally responsible for differences in maximum body size among populations. I hypothesize that body size in many animal species reflects a trade-off between foraging constraints and sexual selection and suggest that future research could focus on physiological and genetic mechanisms determining body size in wild animals. Furthermore, evolutionary stable body size distributions within populations should be analysed to better

Body size, performance and fitness in galapagos marine iguanas.

Science.gov (United States)

Wikelski, Martin; Romero, L Michael

2003-07-01

Complex organismal traits such as body size are influenced by innumerable selective pressures, making the prediction of evolutionary trajectories for those traits difficult. A potentially powerful way to predict fitness in natural systems is to study the composite response of individuals in terms of performance measures, such as foraging or reproductive performance. Once key performance measures are identified in this top-down approach, we can determine the underlying physiological mechanisms and gain predictive power over long-term evolutionary processes. Here we use marine iguanas as a model system where body size differs by more than one order of magnitude between island populations. We identified foraging efficiency as the main performance measure that constrains body size. Mechanistically, foraging performance is determined by food pasture height and the thermal environment, influencing intake and digestion. Stress hormones may be a flexible way of influencing an individual's response to low-food situations that may be caused by high population density, famines, or anthropogenic disturbances like oil spills. Reproductive performance, on the other hand, increases with body size and is mediated by higher survival of larger hatchlings from larger females and increased mating success of larger males. Reproductive performance of males may be adjusted via plastic hormonal feedback mechanisms that allow individuals to assess their social rank annually within the current population size structure. When integrated, these data suggest that reproductive performance favors increased body size (influenced by reproductive hormones), with an overall limit imposed by foraging performance (influenced by stress hormones). Based on our mechanistic understanding of individual performances we predicted an evolutionary increase in maximum body size caused by global warming trends. We support this prediction using specimens collected during 1905. We also show in a common

Evaluation of actual vs expected photodynamic therapy spot size.

Science.gov (United States)

Ranchod, Tushar M; Brucker, Alexander J; Liu, Chengcheng; Cukras, Catherine A; Hopkins, Tim B; Ying, Gui-Shuang

2009-05-01

To determine the accuracy of the photodynamic therapy (PDT) laser spot size on the retina as generated by 2 Food and Drug Administration (FDA)-approved lasers. Prospective observational case series. Fundus photographs were taken of 1 eye of each of 10 subjects with the WinStation 4000 fundus photography system (OIS; Ophthalmic Imaging Systems, Sacramento, California, USA); disc size was calculated using OIS software. Slit-lamp photographs were taken of the PDT laser spot focused on the retina adjacent to the optic disc, using various spot sizes in combination with 3 different contact lenses and 2 different lasers. Spot size at the retina was determined by measuring the ratio of disc diameter to spot diameter in Adobe Photoshop (San Jose, California, USA) and applying this ratio to the OIS disc measurements. Spot size at the retina averaged 87% of expected spot size for the Coherent Opal laser (Coherent Inc, Santa Clara, California, USA) and 104% of expected spot size for the Zeiss Visulas laser (Carl Zeiss Meditec Inc, Dublin, California, USA)(P = .002). Multivariate analysis demonstrated that percentage of expected spot size decreased with larger spot diameter (P = .01 for Coherent laser; P = .02 for Zeiss laser). PDT spot size at the retina appears to be consistently smaller than expected for the Coherent laser while the spot size was consistently within 10% of expected size for the Zeiss laser. The deviation from expected size increased with larger spot size using the Coherent laser.

The relationship between UT reported size and actual size of the defects in rotor forgings

International Nuclear Information System (INIS)

Seong, Un Hak; Kim, Jeong Tae; Park, Yun Sik

2003-01-01

In order to evaluate the reliability of rotor forgings, it is very important to know the actual size of the defects in the rotor forgings. The determination of the defect size requires the accurate non-destructive measurement. However, there may be some differences between the reported size with the ultrasonic non-destructive testing method and the actual size of defects. These differences may be a severe cause of errors in evaluation of rotor forgings. So, the calculated size with 'Master Curve' considering safety factor, which is usually larger than the reported size, has been used in evaluation of rotor forgings. The relation between the EFBH (Equivalent Flat Bottom Hole) size measured by non-destructive method and the actual size by destructive method in many rotors manufactured at Doosan was investigated. In this investigation 'Master Curve' compensating the differences between UT reported size and actual size of defects in our rotor forgings was obtainable. The applicability of this 'Master Curve' as a way of calculating the actual defect size was also investigated. For the evaluation of rotor forgings, it is expected that this 'Master Curve' may be used to determine the accurate actual size of defects.

The relationship between UT reported size and actual size of the defects in rotor forgings

International Nuclear Information System (INIS)

Seong, Un Hak; Kim, Jeong Tae; Park, Yun Sik

2003-01-01

In order to evaluate the reliability of rotor forgings, it is very important to know the actual size of the defects in the rotor forgings. The determination of the defect size requires the accurate non-destructive measurement. However, there may be some difference between the reported size with ultrasonic non-destructive testing method and the actual size of defects. These differences may be a severe cause of errors in evaluation of rotor forgings. So, the calculated size with 'Master Curve' considering safety factor, which is usually larger than the reported size, has been used in evaluation of rotor forgings. The relation between the EFBH (Equivalent Flat Bottom Hole) size measured by non-destructive method and the actual size by destructive method in many rotors manufactured at Doosan was investigated. In this investigation, 'Master Curve' compensating the differences between UT reported size and actual size of defects in our rotor forgings was obtainable. The applicability of this 'Master Curve' as a way of calculating the actual defect size was also investigated. For the evaluation of rotor forgings, it is expected that this 'Master Curve' may be used to determine the accurate actual size of defects.

Effects of anion size and concentration on electrolyte invasion into molecular-sized nanopores

International Nuclear Information System (INIS)

Liu Ling; Chen Xi; Kim, Taewan; Han Aijie; Qiao Yu

2010-01-01

When an electrolyte solution is pressurized into a molecular-sized nanopore, oppositely charged ions are strongly inclined to aggregate, which effectively reduces the ion solubility to zero. Inside the restrictive confinement, a unique quasi-periodic structure is formed where the paired ion couples are periodically separated by a number of water molecules. As the anion size or ion concentration varies, the geometrical characteristics of the confined ion structure would change considerably, leading to a significant variation in the transport pressure. Both experimental and simulation results indicate that, contradictory to the prediction of conventional theory, infiltration pressure decreases as the anions become larger.

Correlation Between Echinoidea Size and Threat Level

Science.gov (United States)

Bakshi, S.; Lee, A.; Heim, N.; Payne, J.

2017-12-01

Echinoidea (or sea urchins), are small, spiny, globular, animals that populate the seafloors of nearly the entire planet. Echinoidea have existed on Earth since the Ordovician period, and from their archaic origin there is much to be learned about the relationship between Echinoidea body size and how it affects the survivability of the individual. The goal of this project is to determine how Echinoidea dimensions such as body volume, area, and length compare across extinct and extant species by plotting Echinoidea data in R. We will use stratigraphic data as a source to find which species of sea urchin from our data is extinct. We will then create three sets of three histograms of the size data for each type of measurement. One set will include histograms for sea urchin length, area, and volume. The other set will include histograms for extinct sea urchin length, area, and volume. The last set will include histograms for extant sea urchin length, area, and volume. Our data showed that extant sea urchins had a larger size, and extinct sea urchins were smaller. Our length data showed that the average length of all sea urchins were 54.95791 mm, the average length of extinct sea urchins were 51.0337 mm, and the average length of extant sea urchins were 66.12774 mm. There is a generally increasing trend of size over time, except for a small outlier about 350 million years ago, where echinoderm extinction selected towards larger species and biovolume was abnormally high. Our data also showed that over the past 200 million years, echinoderm extinction selectivity drove slightly smaller sea urchins towards extinction, further supporting the idea that a larger size was and still is advantageous for echinoderms.

Effects of patch size on feeding associations in muriquis (Brachyteles arachnoides).

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Strier, K B

1989-01-01

Data were collected on one group of muriquis, or woolly spider monkeys (Brachyteles arachnoides) during a 14-month study at Fazenda Montes Claros, Minas Gerais, Brazil to examine the effects of food patch size on muriqui feeding associations. Muriqui food patches were larger than expected from the availability of patch sizes in the forest; fruit patches were significantly larger than leaf patches. Feeding aggregate size, the maximum number of simultaneous occupants, and patch occupancy time were positively related to the size of fruit patches. However, a greater number of individuals fed at leaf sources than expected from the size of these patches. Adult females tended to feed alone in patches more often than males, whereas males tended to feed in single-sexed groups more often than females. Yet in neither case were these differences statistically significant.

Energetic tradeoffs control the size distribution of aquatic mammals

Science.gov (United States)

Gearty, William; McClain, Craig R.; Payne, Jonathan L.

2018-04-01

Four extant lineages of mammals have invaded and diversified in the water: Sirenia, Cetacea, Pinnipedia, and Lutrinae. Most of these aquatic clades are larger bodied, on average, than their closest land-dwelling relatives, but the extent to which potential ecological, biomechanical, and physiological controls contributed to this pattern remains untested quantitatively. Here, we use previously published data on the body masses of 3,859 living and 2,999 fossil mammal species to examine the evolutionary trajectories of body size in aquatic mammals through both comparative phylogenetic analysis and examination of the fossil record. Both methods indicate that the evolution of an aquatic lifestyle is driving three of the four extant aquatic mammal clades toward a size attractor at ˜500 kg. The existence of this body size attractor and the relatively rapid selection toward, and limited deviation from, this attractor rule out most hypothesized drivers of size increase. These three independent body size increases and a shared aquatic optimum size are consistent with control by differences in the scaling of energetic intake and cost functions with body size between the terrestrial and aquatic realms. Under this energetic model, thermoregulatory costs constrain minimum size, whereas limitations on feeding efficiency constrain maximum size. The optimum size occurs at an intermediate value where thermoregulatory costs are low but feeding efficiency remains high. Rather than being released from size pressures, water-dwelling mammals are driven and confined to larger body sizes by the strict energetic demands of the aquatic medium.

Myonuclear domain size and myosin isoform expression in muscle fibres from mammals representing a 100,000-fold difference in body size.

Science.gov (United States)

Liu, Jing-Xia; Höglund, Anna-Stina; Karlsson, Patrick; Lindblad, Joakim; Qaisar, Rizwan; Aare, Sudhakar; Bengtsson, Ewert; Larsson, Lars

2009-01-01

This comparative study of myonuclear domain (MND) size in mammalian species representing a 100,000-fold difference in body mass, ranging from 25 g to 2500 kg, was undertaken to improve our understanding of myonuclear organization in skeletal muscle fibres. Myonuclear domain size was calculated from three-dimensional reconstructions in a total of 235 single muscle fibre segments at a fixed sarcomere length. Irrespective of species, the largest MND size was observed in muscle fibres expressing fast myosin heavy chain (MyHC) isoforms, but in the two smallest mammalian species studied (mouse and rat), MND size was not larger in the fast-twitch fibres expressing the IIA MyHC isofom than in the slow-twitch type I fibres. In the larger mammals, the type I fibres always had the smallest average MND size, but contrary to mouse and rat muscles, type IIA fibres had lower mitochondrial enzyme activities than type I fibres. Myonuclear domain size was highly dependent on body mass in the two muscle fibre types expressed in all species, i.e. types I and IIA. Myonuclear domain size increased in muscle fibres expressing both the beta/slow (type I; r = 0.84, P fast IIA MyHC isoform (r = 0.90; P muscle fibre type, independent of species. However, myosin isoform expression is not the sole protein determining MND size, and other protein systems, such as mitochondrial proteins, may be equally or more important determinants of MND size.

Concerted evolution of body mass and cell size: similar patterns among species of birds (Galliformes) and mammals (Rodentia)

Science.gov (United States)

Dragosz-Kluska, Dominika; Pis, Tomasz; Pawlik, Katarzyna; Kapustka, Filip; Kilarski, Wincenty M.; Kozłowski, Jan

2018-01-01

ABSTRACT Cell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs). In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells) and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity. PMID:29540429

Concerted evolution of body mass and cell size: similar patterns among species of birds (Galliformes and mammals (Rodentia

Directory of Open Access Journals (Sweden)

Marcin Czarnoleski

2018-04-01

Full Text Available Cell size plays a role in body size evolution and environmental adaptations. Addressing these roles, we studied body mass and cell size in Galliformes birds and Rodentia mammals, and collected published data on their genome sizes. In birds, we measured erythrocyte nuclei and basal metabolic rates (BMRs. In birds and mammals, larger species consistently evolved larger cells for five cell types (erythrocytes, enterocytes, chondrocytes, skin epithelial cells, and kidney proximal tubule cells and evolved smaller hepatocytes. We found no evidence that cell size differences originated through genome size changes. We conclude that the organism-wide coordination of cell size changes might be an evolutionarily conservative characteristic, and the convergent evolutionary body size and cell size changes in Galliformes and Rodentia suggest the adaptive significance of cell size. Recent theory predicts that species evolving larger cells waste less energy on tissue maintenance but have reduced capacities to deliver oxygen to mitochondria and metabolize resources. Indeed, birds with larger size of the abovementioned cell types and smaller hepatocytes have evolved lower mass-specific BMRs. We propose that the inconsistent pattern in hepatocytes derives from the efficient delivery system to hepatocytes, combined with their intense involvement in supracellular function and anabolic activity.

Allometry of sexual size dimorphism in domestic dog.

Directory of Open Access Journals (Sweden)

Daniel Frynta

Full Text Available The tendency for male-larger sexual size dimorphism (SSD to scale with body size - a pattern termed Rensch's rule - has been empirically supported in many animal lineages. Nevertheless, its theoretical elucidation is a subject of debate. Here, we exploited the extreme morphological variability of domestic dog (Canis familiaris to gain insights into evolutionary causes of this rule.We studied SSD and its allometry among 74 breeds ranging in height from less than 19 cm in Chihuahua to about 84 cm in Irish wolfhound. In total, the dataset included 6,221 individuals. We demonstrate that most dog breeds are male-larger, and SSD in large breeds is comparable to SSD of their wolf ancestor. Among breeds, SSD becomes smaller with decreasing body size. The smallest breeds are nearly monomorphic.SSD among dog breeds follows the pattern consistent with Rensch's rule. The variability of body size and corresponding changes in SSD among breeds of a domestic animal shaped by artificial selection can help to better understand processes leading to emergence of Rensch's rule.

Interpretations of family size distributions: The Datura example

Science.gov (United States)

Henych, Tomáš; Holsapple, Keith A.

2018-04-01

Young asteroid families are unique sources of information about fragmentation physics and the structure of their parent bodies, since their physical properties have not changed much since their birth. Families have different properties such as age, size, taxonomy, collision severity and others, and understanding the effect of those properties on our observations of the size-frequency distribution (SFD) of family fragments can give us important insights into the hypervelocity collision processes at scales we cannot achieve in our laboratories. Here we take as an example the very young Datura family, with a small 8-km parent body, and compare its size distribution to other families, with both large and small parent bodies, and created by both catastrophic and cratering formation events. We conclude that most likely explanation for the shallower size distribution compared to larger families is a more pronounced observational bias because of its small size. Its size distribution is perfectly normal when its parent body size is taken into account. We also discuss some other possibilities. In addition, we study another common feature: an offset or "bump" in the distribution occurring for a few of the larger elements. We hypothesize that it can be explained by a newly described regime of cratering, "spall cratering", which controls the majority of impact craters on the surface of small asteroids like Datura.

Object size effects on initial lifting forces under microgravity conditions

NARCIS (Netherlands)

Kingma, I.; Savelsbergh, G.J.P.; Toussaint, H.M.

1999-01-01

Individuals usually report for two objects of equal mass but different volume that the larger object feels lighter. This so-called size-weight illusion has been investigated for more than a century. The illusion is accompanied by increased forces, used to lift the larger object, resulting in a

Size distributions and dispersions along a 485-year chronosequence for sand dune vegetation.

Science.gov (United States)

Waugh, Jennifer M; Aarssen, Lonnie W

2012-04-01

Using a sand dune chronosequence that spans 485 years of primary succession, we collected nearest-neighbor vegetation data to test two predictions associated with the traditional "size-advantage" hypothesis for plant competitive ability: (1) the relative representation of larger species should increase in later stages of succession; and (2) resident species that are near neighbors should, over successional time, become more similar in plant body size and/or seed size than expected by random assembly. The first prediction was supported over the time period between mid to later succession, but the second prediction was not; that is, there was no temporal pattern across the chronosequence indicating that either larger resident species, or larger seeded resident species, increasingly exclude smaller ones from local neighborhoods over time. Rather, neighboring species were generally more different from each other in seed sizes than expected by random assembly. As larger species accumulate over time, some relatively small species are lost from later stages of succession, but species size distributions nevertheless remain strongly right-skewed-even in late succession-and species of disparate sizes are just as likely as in early succession to coexist as immediate neighbors. This local-scale coexistence of disparate sized neighbors might be accounted for-as in traditional interpretations-in terms of species differences in "physical-space-niches" (e.g., involving different rooting depths), combined with possible facilitation effects. We propose, however, that this coexistence may also occur because competitive ability involves more than just a size advantage, with traits associated with survival (tolerance of intense competition) and fecundity (offspring production despite intense competition) being at least equally important.

Simulation of the measure of the microparticle size distribution in two dimensions

International Nuclear Information System (INIS)

Lameiras, F.S.; Pinheiro, P.

1987-01-01

Different size distributions of plane figures were generated in a computer as a simply connected network. These size distributions were measured by the Saltykov method for two dimensions. The comparison between the generated and measured distributions showed that the Saltkov method tends to measure larger scattering than the real one and to move the maximum of the real distribution to larger diameters. These erros were determined by means of the ratio of the perimeter of the figures per unit area directly measured and the perimeter calculated from the size distribution obtained by using the SaltyKov method. (Author) [pt

Maternal effects of egg size on emu Dromaius novaehollandiae egg composition and hatchling phenotype.

Science.gov (United States)

Dzialowski, Edward M; Sotherland, Paul R

2004-02-01

Parental investment in eggs and, consequently, in offspring can profoundly influence the phenotype, survival and ultimately evolutionary fitness of an organism. Avian eggs are excellent model systems to examine maternal allocation of energy translated through egg size variation. We used the natural range in emu Dromaius novaehollandiae egg size, from 400 g to >700 g, to examine the influence of maternal investment in eggs on the morphology and physiology of hatchlings. Female emus provisioned larger eggs with a greater absolute amount of energy, nutrients and water in the yolk and albumen. Variation in maternal investment was reflected in differences in hatchling size, which increased isometrically with egg size. Egg size also influenced the physiology of developing emu embryos, such that late-term embryonic metabolic rate was positively correlated with egg size and embryos developing in larger eggs consumed more yolk during development. Large eggs produced hatchlings that were both heavier (yolk-free wet and dry mass) and structurally larger (tibiotarsus and culmen lengths) than hatchlings emerging from smaller eggs. As with many other precocial birds, larger hatchlings also contained more water, which was reflected in a greater blood volume. However, blood osmolality, hemoglobin content and hematocrit did not vary with hatchling mass. Emu maternal investment in offspring, measured by egg size and composition, is significantly correlated with the morphology and physiology of hatchlings and, in turn, may influence the success of these organisms during the first days of the juvenile stage.

Myc contribution to γ-ray induced thymic lymphomas in mice of different genetic predispositions

International Nuclear Information System (INIS)

Sato, Toshihiro

2008-01-01

Myc gene has been suggested to be one of radiation targets in early genesis of γ ray-induced thymic lymphoma where Myc trisomy often occurs, and Myc activation results in p53 activation and apoptosis. The purpose of this study is to see the effects of radiation and mutation on Myc activation in the mouse. The lymphoma was induced by a single exposure of 3 Gy γ ray in BALB/c Bcl11b/Rit+/- and MSM p53-/- mice at 4 weeks after birth and by 4 weekly exposures of 2.5 Gy in p53+/- mouse. Genetic allele analysis for trisomy identification in the lymphoma was done by quantitative PCR using brain DNA as a control. Myc trisomy was found in the lymphoma of p53+/- mouse in 62% (23/37 animals) and of p53+/+, 66% (23/25), a similar frequency, suggesting that the target of radiation was not only the Myc activation. In addition, Myc trisomy frequency was 15% (4/27) in the lymphoma of Bcl11b+/+p53+/- and 36% (9/25), in heterozygote Bcl11b+/-. This finding suggested that the functional failure of Bcl11b reduced the contribution of Myc trisomy to the genesis. It was concluded that contribution of Myc trisomy to genesis of the lymphoma was dependent on genetic predisposition, and Myc-activated-, Bcl11b/Rit1-signal pathways played a parallel role in the genesis. (R.T.)

Geographical variation in body size and sexual size dimorphism in an Australian lizard, Boulenger's Skink (Morethia boulengeri).

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Michael, Damian R; Banks, Sam C; Piggott, Maxine P; Cunningham, Ross B; Crane, Mason; MacGregor, Christopher; McBurney, Lachlan; Lindenmayer, David B

2014-01-01

Ecogeographical rules help explain spatial and temporal patterns in intraspecific body size. However, many of these rules, when applied to ectothermic organisms such as reptiles, are controversial and require further investigation. To explore factors that influence body size in reptiles, we performed a heuristic study to examine body size variation in an Australian lizard, Boulenger's Skink Morethia boulengeri from agricultural landscapes in southern New South Wales, south-eastern Australia. We collected tissue and morphological data on 337 adult lizards across a broad elevation and climate gradient. We used a model-selection procedure to determine if environmental or ecological variables best explained body size variation. We explored the relationship between morphology and phylogenetic structure before modeling candidate variables from four broad domains: (1) geography (latitude, longitude and elevation), (2) climate (temperature and rainfall), (3) habitat (vegetation type, number of logs and ground cover attributes), and (4) management (land use and grazing history). Broad phylogenetic structure was evident, but on a scale larger than our study area. Lizards were sexually dimorphic, whereby females had longer snout-vent length than males, providing support for the fecundity selection hypothesis. Body size variation in M. boulengeri was correlated with temperature and rainfall, a pattern consistent with larger individuals occupying cooler and more productive parts of the landscape. Climate change forecasts, which predict warmer temperature and increased aridity, may result in reduced lizard biomass and decoupling of trophic interactions with potential implications for community organization and ecosystem function.

Andrographolide suppresses thymic stromal lymphopoietin in phorbol myristate acetate/calcium ionophore A23187-activated mast cells and 2,4-dinitrofluorobenzene-induced atopic dermatitis-like mice model

Directory of Open Access Journals (Sweden)

Li CX

2016-02-01

Full Text Available Chun-xiao Li,* Hua-guo Li,* Hui Zhang,* Ru-hong Cheng, Ming Li, Jian-ying Liang, Yan Gu, Bo Ling, Zhi-rong Yao, Hong Yu Department of Dermatology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China *These authors contributed equally to this work Background: Atopic dermatitis (AD is one of the most common inflammatory cutaneous diseases. Thymic stromal lymphopoietin (TSLP has been demonstrated to be an important immunologic factor in the pathogenesis of AD. The production of TSLP can be induced by a high level of intracellular calcium concentration and activation of the receptor-interacting protein 2/caspase-1/NF-κB pathway. Andrographolide (ANDRO, a natural bicyclic diterpenoid lactone, has been found to exert anti-inflammatory effects in gastrointestinal inflammatory disorders through suppressing the NF-κB pathway. Objective: To explore the effect of ANDRO on the production of TSLP in human mast cells and AD mice model. Methods: We utilized enzyme-linked immunosorbent assay, real-time reverse transcription polymerase chain reaction analysis, Western blot analysis, and immunofluorescence staining assay to investigate the effects of ANDRO on AD. Results: ANDRO ameliorated the increase in the intracellular calcium, protein, and messenger RNA levels of TSLP induced by phorbol myristate acetate/calcium ionophore A23187, through the blocking of the receptor-interacting protein 2/caspase-1/NF-κB pathway in human mast cell line 1 cells. ANDRO, via oral or local administration, also attenuated clinical symptoms in 2,4-dinitrofluorobenzene-induced AD mice model and suppressed the levels of TSLP in lesional skin. Conclusion: Taken together, ANDRO may be a potential therapeutic agent for AD through suppressing the expression of TSLP. Keywords: atopic dermatitis, thymic stromal lymphopoietin, andrographolide, human mast cell

Ultraviolet (UV) disinfection of grey water: particle size effects.

Science.gov (United States)

Winward, G P; Avery, L M; Stephenson, T; Jefferson, B

2008-02-01

The impact of water quality on the ultraviolet (UV) disinfection of grey water was investigated with reference to urban water reuse. Direct UV disinfection of grey water did not meet the stringent California State Title 22 criteria for unrestricted urban water reuse due to the presence of particulate material ranging from or = 2000 microm in size. Grey water was manipulated by settling to produce fractions of varying particle size distributions and blending was employed post-disinfection to extract particle-associated coliforms (PACs). The efficacy of UV disinfection was found to be linked to the particle size of the grey water fractions. The larger particle size fractions with a mean particle size of 262 microm and above were observed to shield more coliforms from UV light than did the smaller particles with a mean particle size below 119 microm. Up to 70% of total coliforms in the larger particle size fractions were particle-associated following a UV dose (fluence) of 260 mJ.cm(-2) and would remain undetected by standard coliform enumeration techniques. Implications for urban water reuse are discussed and recommendations made for grey water treatment to ensure removal of particle-associated indicator bacteria and pathogens prior to UV disinfection.

Production of sized particles of uranium oxides and uranium oxyfluorides

International Nuclear Information System (INIS)

Knudsen, I.E.; Randall, C.C.

1976-01-01

A process is claimed for converting uranium hexafluoride (UF 6 ) to uranium dioxide (UO 2 ) of a relatively large particle size in a fluidized bed reactor by mixing uranium hexafluoride with a mixture of steam and hydrogen and by preliminary reacting in an ejector gaseous uranium hexafluoride with steam and hydrogen to form a mixture of uranium and oxide and uranium oxyfluoride seed particles of varying sizes, separating the larger particles from the smaller particles in a cyclone separator, recycling the smaller seed particles through the ejector to increase their size, and introducing the larger seed particles from the cyclone separator into a fluidized bed reactor where the seed particles serve as nuclei on which coarser particles of uranium dioxide are formed. 9 claims, 2 drawing figures

MR evaluation of postmenopausal ovarian size. Comparison with surgical specimen

International Nuclear Information System (INIS)

Joja, Ikuo; Ishida, Kana; Matsushita, Toshi; Mimura, Seiichi; Yamaguchi, Takuya; Akagi, Noriaki; Miyagi, Yasunari; Hara, Takeshi; Kanazawa, Susumu

2008-01-01

We investigated ovarian size after menopause using magnetic resonance (MR) imaging and gross specimens obtained from patients with uterine cancer after menopause in whom normal ovaries were confirmed at the time of surgery. The relationships between size of ovarian long axis and age, the number of years since menopause, and age at menopause were statistically evaluated for 130 ovaries observed in short-axis T 2 -weighted MR images of the uterine corpus and in 147 ovarian gross specimens. No significant relationships were found between size of ovarian long axis and these 3 factors. When the sizes of the ovaries in MR images were compared with those in gross specimens, the latter were larger, with a statistically significant difference. Similarly, when the sizes of the ovaries observed or not observed in MR images were compared in gross specimens, the former were larger, with a statistically significant difference. These results indicate that the size of the ovarian long axis observed in MR images does not accurately reflect the true size of the long axis, but ovarian size strongly affects visualization of the ovaries in MR images after menopause. In addition, these results indicate that there are no significant relationships between ovarian size after menopause and age, the number of years since menopause, or age at menopause. (author)

Ecological correlates of relative brain size in some South African ...

African Journals Online (AJOL)

Relative brain size (size of the brain once body size effects have been removed) has been calculated for 16 species of rodent from South Africa and is shown to vary with six species having a positive RBS (that is a brain larger than expected) and 10 a negative RBS. Arboreal species such as Paraxerus cepapi and ...

A general solution for optimal egg size during external fertilization, extended scope for intermediate optimal egg size and the introduction of Don Ottavio 'tango'

NARCIS (Netherlands)

Luttikhuizen, PC; Honkoop, PJC; Drent, J; van der Meer, J

2004-01-01

Egg sizes of marine invertebrates vary greatly, both within and between species. Among the proposed causes of this are a trade-off between egg size, egg number and survival probability of offspring, and a selection pressure exerted by sperm limitation during external fertilization. Although larger

The Roles of Size and Size Difference in Australian and Chinese Inter-firm Collaborations

Directory of Open Access Journals (Sweden)

Yu Zhang

Full Text Available There has been considerable debate on the contribution and significance of firm size to the establishment, operation and success of business collaboration. One important source of this debate arises from differing definitions of firm size used in previous research. This paper uses firm size categories and size differences between collaborating firms to examine their contribution to the formation and performance of inter-firmcollaboration in Australia and China. Both qualitative case study and quantitative data analyses are adopted in this paper. Results from both the qualitative case study and quantitative study in Australia and China show that size plays a significant positive role in the formation and performance of business collaboration. Firmsprefer collaborating with larger partners. Bigger firms are more likely to achieve success collaborations. However, size difference plays a negative role in business collaboration. Collaborating with a bigger partner makes it harder to succeed. On the other hand, size and size difference play very different roles in performanceand outcomes of business collaboration in different countries.This paper compares the roles of firm size and size difference in Australian and Chinese inter-firm collaboration. The results provide important strategic implications for business managers, industry regulators, and policy decision makers regarding international business collaboration.

Single-larger-portion-size and dual-column nutrition labeling may help consumers make more healthful food choices.

Science.gov (United States)

Lando, Amy M; Lo, Serena C

2013-02-01

The Food and Drug Administration is considering changes to the Nutrition Facts label to help consumers make more healthful choices. To examine the effects of modifications to the Nutrition Facts label on foods that can be listed as having 1 or 2 servings per container, but are reasonably consumed at a single eating occasion. Participants were randomly assigned to study conditions that varied on label format, product, and nutrition profile. Data were collected via an online consumer panel. Adults aged 18 years and older were recruited from Synovate's online household panel. Data were collected during August 2011. A total of 32,897 invitations were sent for a final sample of 9,493 interviews. Participants were randomly assigned to one of 10 label formats classified into three groups: listing 2 servings per container with a single column, listing 2 servings per container with a dual column, and listing a single serving per container. Within these groups there were versions that enlarged the font size for "calories," removed "calories from fat," and changed the wording for serving size declaration. The single product task measured product healthfulness, the amount of calories and various nutrients per serving and per container, and label perceptions. The product comparison task measured ability to identify the healthier product and the product with fewer calories per container and per serving. Analysis of covariance models with Tukey-Kramer tests were used. Covariates included general label use, age, sex, level of education, and race/ethnicity. Single-serving and dual-column formats performed better and scored higher on most outcome measures. For products that contain 2 servings but are customarily consumed at a single eating occasion, using a single-serving or dual-column labeling approach may help consumers make healthier food choices. Published by Elsevier Inc.

78 FR 37404 - Small Business Size Standards: Support Activities for Mining

Science.gov (United States)

2013-06-20

... assistance programs, SBA establishes small business size definitions (referred to as size standards) for... million should be the limit of a small business definition and anything larger than that, such as that SBA... Business Act (15 U.S.C. 632(a)) (Act) requires that small business size definitions vary to reflect...

The Attenuated Live Yellow Fever Virus 17D Infects the Thymus and Induces Thymic Transcriptional Modifications of Immunomodulatory Genes in C57BL/6 and BALB/C Mice

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Breno Luiz Melo-Lima

2015-01-01

Full Text Available Thymus is involved in induction of self-tolerance in T lymphocytes, particularly due to Aire activity. In peripheral tissues, Treg cells and immunomodulatory molecules, like the major histocompatibility complex (MHC class Ib molecules, are essential for maintenance of autotolerance during immune responses. Viral infections can trigger autoimmunity and modify thymic function, and YFV17D immunization has been associated with the onset of autoimmunity, being contraindicated in patients with thymic disorders. Aiming to study the influence of YFV17D immunization on the transcriptional profiles of immunomodulatory genes in thymus, we evaluated the gene expression of AIRE, FOXP3, H2-Q7 (Qa-2/HLA-G, H2-T23 (Qa-1/HLA-E, H2-Q10, and H2-K1 following immunization with 10,000 LD50 of YFV17D in C57BL/6 and BALB/c mice. The YFV17D virus replicated in thymus and induced the expression of H2-Q7 (Qa-2/HLA-G and H2-T23 (Qa-1/HLA-E transcripts and repressed the expression of AIRE and FOXP3. Transcriptional expression varied according to tissue and mouse strain analyzed. Expression of H2-T23 (Qa-1/HLA-E and FOXP3 was induced in thymus and liver of C57BL/6 mice, which exhibited defective control of viral load, suggesting a higher susceptibility to YFV17D infection. Since the immunization with YFV17D modulated thymus gene expression in genetically predisposed individuals, the vaccine may be related to the onset of autoimmunity disorders.

Thymic Output and CD4 T-Cell Reconstitution in HIV-Infected Children on Early and Interrupted Antiretroviral Treatment: Evidence from the Children with HIV Early Antiretroviral Therapy Trial

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Joanna Lewis

2017-09-01

Full Text Available ObjectivesEarly treatment of HIV-infected children and adults is important for optimal immune reconstitution. Infants’ immune systems are more plastic and dynamic than older children’s or adults’, and deserve particular attention. This study aimed to understand the response of the HIV-infected infant immune system to early antiretroviral therapy (ART and planned ART interruption and restart.MethodsData from HIV-infected children enrolled the CHER trial, starting ART aged between 6 and 12 weeks, were used to explore the effect of ART on immune reconstitution. We used linear and non-linear regression and mixed-effects models to describe children’s CD4 trajectories and to identify predictors of CD4 count during early and interrupted ART.ResultsEarly treatment arrested the decline in CD4 count but did not fully restore it to the levels observed in HIV-uninfected children. Treatment interruption at 40 or 96 weeks resulted in a rapid decline in CD4 T-cells, which on retreatment returned to levels observed before interruption. Naïve CD4 T-cell count was an important determinant of overall CD4 levels. A strong correlation was observed between thymic output and the stable CD4 count both before and after treatment interruption.ConclusionEarly identification and treatment of HIV-infected infants is important to stabilize CD4 counts at the highest levels possible. Once stabilized, children’s CD4 counts appear resilient, with good potential for recovery following treatment interruption. The naïve T-cell pool and thymic production of naive cells are key determinants of children’s CD4 levels.

Suppressive effects of Lactobacillus casei cells, a bacterial immunostimulant, on the incidence of spontaneous thymic lymphoma in AKR mice.

Science.gov (United States)

Watanabe, T

1996-06-01

The mean survival age of female AKR/J mice was significantly prolonged, the enlargement of thymus was markedly suppressed, and the proliferation of ecotropic and recombinant murine leukemia viruses (MuLV) was markedly inhibited when 8-week-old female AKR/J mice were injected intraperitoneally (i.p.) with heat-killed Lactobacillus casei cells twice weekly for 8 weeks. In contrast, such actions of heat-killed L. casei cells were not seen in 20-week-old female AKR/J mice. The leukemogenic activity of the cell-free extract of thymus from adult female AKR/J mice in newborn female AKR/J mice was drastically reduced by i.p. treatment with heat-killed L. casei cells. The difference in adjuvant effectiveness of heat-killed L. casei cells on 8- and 20-week-old animals may be dependent on the difference in the enhancing activity of the cell-mediated immune systems between the groups induced by heat-killed L. casei cells, and, as a result, on the difference in the degree of proliferation of ecotropic and recombinant MuLV in thymus, which consequently causes thymic lymphoma.

Size Matters: Penis Size and Sexual Position in Gay Porn Profiles.

Science.gov (United States)

Brennan, Joseph

2018-01-01

This article combines qualitative and quantitative textual approaches to the representation of penis size and sexual position of performers in 10 of the most visited gay pornography Web sites currently in operation. Specifically, in excess of 6,900 performer profiles sourced from 10 commercial Web sites are analyzed. Textual analysis of the profile descriptions is combined with a quantitative representation of disclosed penis size and sexual position, which is presented visually by two figures. The figures confirm that these sites generally market themselves as featuring penises that are extraordinarily large and find a sample-wide correlation between smaller penis sizes (5-6.5 inches) and receptive sexual acts (bottoming), and larger (8.5-13 inches) with penetrative acts (topping). These observations are supported through the qualitative textual readings of how the performers are described on these popular sites, revealing the narratives and marketing strategies that shape the construction of popular porn brands, performers, and profitable fantasies.

Measurements of the size dependence of the concentration of nonvolatile material in fog droplets

Science.gov (United States)

Ogren, J. A.; Noone, K. J.; Hallberg, A.; Heintzenberg, J.; Schell, D.; Berner, A.; Solly, I.; Kruisz, C.; Reischl, G.; Arends, B. G.; Wobrock, W.

1992-11-01

Measurements of the size dependence of the mass concentration of nonvolatile material dissolved and suspended in fog droplets were obtained with three complementary approaches, covering a size range from c. 1 50µm diameter: a counterflow virtual impactor, an eight-stage aerosol impactor, and a two-stage fogwater impactor. Concentrations were observed to decrease with size over the entire range, contrary to expectations of increasing concentrations at larger sizes. It is possible that the larger droplets had solute concentrations that increased with increasing size, but that the increase was too weak for the measurements to resolve. Future studies should consider the hypothesis that the droplets were coated with a surface-active substance that hindered their uptake of water.

Consequences of sex-specific growth on sibling competition in black-headed gulls : A sexually-size dimorphic species with scramble competition

NARCIS (Netherlands)

Mueller, Wendt; Groothuis, Ton G. G.; Dijkstra, Cor

2007-01-01

Biased mortality of the larger sex during the early developmental period has been reported for a number of size-dimorphic bird species. This can partly be explained by the fact that growing to larger size renders the larger sex more vulnerable to food shortage. However, since sibling rivalry is

Food web structure shaped by habitat size and climate across a latitudinal gradient.

Science.gov (United States)

Romero, Gustavo Q; Piccoli, Gustavo C O; de Omena, Paula M; Gonçalves-Souza, Thiago

2016-10-01

Habitat size and climate are known to affect the trophic structure and dynamics of communities, but their interactive effects are poorly understood. Organisms from different trophic levels vary in terms of metabolic requirements and heat dissipation. Indeed, larger species such as keystone predators require more stable climatic conditions than their prey. Likewise, habitat size disproportionally affects large-sized predators, which require larger home ranges and are thus restricted to larger habitats. Therefore, food web structure in patchy ecosystems is expected to be shaped by habitat size and climate variations. Here we investigate this prediction using natural aquatic microcosm (bromeliad phytotelmata) food webs composed of litter resources (mainly detritus), detritivores, mesopredators, and top predators (damselflies). We surveyed 240 bromeliads of varying sizes (water retention capacity) across 12 open restingas in SE Brazil spread across a wide range of tropical latitudes (-12.6° to -27.6°, ca. 2,000 km) and climates (Δ mean annual temperature = 5.3°C). We found a strong increase in predator-to-detritivore mass ratio with habitat size, which was representative of a typical inverted trophic pyramid in larger ecosystems. However, this relationship was contingent among the restingas; slopes of linear models were steeper in more stable and favorable climates, leading to inverted trophic pyramids (and top-down control) being more pronounced in environments with more favorable climatic conditions. By contrast, detritivore-resource and mesopredator-detritivore mass ratios were not affected by habitat size or climate variations across latitudes. Our results highlight that the combined effects of habitat size, climate and predator composition are pivotal to understanding the impacts of multiple environmental factors on food web structure and dynamics. © 2016 by the Ecological Society of America.

Is a larger refuge always better? Dispersal and dose in pesticide resistance evolution.

Science.gov (United States)

Takahashi, Daisuke; Yamanaka, Takehiko; Sudo, Masaaki; Andow, David A

2017-06-01

The evolution of resistance against pesticides is an important problem of modern agriculture. The high-dose/refuge strategy, which divides the landscape into treated and nontreated (refuge) patches, has proven effective at delaying resistance evolution. However, theoretical understanding is still incomplete, especially for combinations of limited dispersal and partially recessive resistance. We reformulate a two-patch model based on the Comins model and derive a simple quadratic approximation to analyze the effects of limited dispersal, refuge size, and dominance for high efficacy treatments on the rate of evolution. When a small but substantial number of heterozygotes can survive in the treated patch, a larger refuge always reduces the rate of resistance evolution. However, when dominance is small enough, the evolutionary dynamics in the refuge population, which is indirectly driven by migrants from the treated patch, mainly describes the resistance evolution in the landscape. In this case, for small refuges, increasing the refuge size will increase the rate of resistance evolution. Our analysis distils major driving forces from the model, and can provide a framework for understanding directional selection in source-sink environments. © 2017 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

6 Tips for Managing Portion Size

Science.gov (United States)

Eating healthy is about enjoying your food while also managing portion size. Most people eat and drink more than their bodies need especially when they are served larger portions. So, choosing smaller portions to begin with is important for maintaining your overall health and well-being.

Only half right: species with female-biased sexual size dimorphism consistently break Rensch's rule.

Directory of Open Access Journals (Sweden)

Thomas J Webb

2007-09-01

Full Text Available Most animal species display Sexual Size Dimorphism (SSD: males and females consistently attain different sizes, most frequently with females being larger than males. However the selective mechanisms driving patterns of SSD remain controversial. 'Rensch's rule' proposes a general scaling phenomenon for all taxa, whereby SSD increases with average body size when males are larger than females, and decreases with body size when females are larger than males. Rensch's rule appears to be general in the former case, but there is little evidence for the rule when females are larger then males.Using comprehensive data for 1291 species of birds across 30 families, we find strong support for Rensch's rule in families where males are typically larger than females, but no overall support for the rule in families with female-biased SSD. Reviewing previous studies of a broad range of taxa (arthropods, reptiles, fish and birds showing predominantly female-biased SSD, we conclude that Rensch's conjecture is the exception rather than the rule in such species.The absence of consistent scaling of SSD in taxa with female-biased SSD, the most prevalent direction of dimorphism, calls into question previous general evolutionary explanations for Rensch's rule. We propose that, unlike several other ecological scaling relationships, Rensch's rule does not exist as an independent scaling phenomenon.

Thymus size at 6 months of age and subsequent child mortality.

Science.gov (United States)

Garly, May-Lill; Trautner, Sisse Lecanda; Marx, Charlotte; Danebod, Kamilla; Nielsen, Jens; Ravn, Henrik; Martins, Cesário Lourenco; Balé, Carlito; Aaby, Peter; Lisse, Ida Maria

2008-11-01

To examine determinants of thymus size at age 6 months and investigate whether thymus size at this age is a determinant of subsequent mortality. Thymus size was measured by transsternal sonography in 923 6-month-old children participating in a measles vaccination trial in Guinea-Bissau. Thymus size was strongly associated with anthropometric measurements. Boys had larger thymuses than girls, controlling for anthropometry. Crying during sonography made the thymus appear smaller. Children who were not vaccinated with Bacille Calmette-Guérin (BCG) or were vaccinated with BCG in the preceding 4 weeks before inclusion into the study had larger thymuses. Children who had malaria or had been treated with chloroquine or Quinimax in the previous week before inclusion had smaller thymuses. Controlled for background factors associated with thymus size and mortality, small thymus size remained a strong and independent risk factor for mortality (hazard ratio = 0.31; 95% confidence interval = 0.18 to 0.52). Small thymus size at age 6 months is a strong risk factor for mortality. To prevent unnecessary deaths, it is important to identify preventable factors predisposing to small thymus size.

ON THE RELATIVE SIZES OF PLANETS WITHIN KEPLER MULTIPLE-CANDIDATE SYSTEMS

International Nuclear Information System (INIS)

Ciardi, David R.; Fabrycky, Daniel C.; Ford, Eric B.; Ragozzine, Darin; Gautier, T. N. III; Howell, Steve B.; Lissauer, Jack J.; Rowe, Jason F.

2013-01-01

We present a study of the relative sizes of planets within the multiple-candidate systems discovered with the Kepler mission. We have compared the size of each planet to the size of every other planet within a given planetary system after correcting the sample for detection and geometric biases. We find that for planet pairs for which one or both objects are approximately Neptune-sized or larger, the larger planet is most often the planet with the longer period. No such size-location correlation is seen for pairs of planets when both planets are smaller than Neptune. Specifically, if at least one planet in a planet pair has a radius of ∼> 3 R ⊕ , 68% ± 6% of the planet pairs have the inner planet smaller than the outer planet, while no preferred sequential ordering of the planets is observed if both planets in a pair are smaller than ∼ ⊕ .

Offspring fitness and individual optimization of clutch size

Science.gov (United States)

Both, C.; Tinbergen, J. M.; Noordwijk, A. J. van

1998-01-01

Within-year variation in clutch size has been claimed to be an adaptation to variation in the individual capacity to raise offspring. We tested this hypothesis by manipulating brood size to one common size, and predicted that if clutch size is individually optimized, then birds with originally large clutches have a higher fitness than birds with originally small clutches. No evidence was found that fitness was related to the original clutch size, and in this population clutch size is thus not related to the parental capacity to raise offspring. However, offspring from larger original clutches recruited better than their nest mates that came from smaller original clutches. This suggests that early maternal or genetic variation in viability is related to clutch size.

Dolphin underwater bait-balling behaviors in relation to group and prey ball sizes.

Science.gov (United States)

Vaughn-Hirshorn, Robin L; Muzi, Elisa; Richardson, Jessica L; Fox, Gabriella J; Hansen, Lauren N; Salley, Alyce M; Dudzinski, Kathleen M; Würsig, Bernd

2013-09-01

We characterized dusky dolphin (Lagenorhynchus obscurus) feeding behaviors recorded on underwater video, and related behaviors to variation in prey ball sizes, dolphin group sizes, and study site (Argentina versus New Zealand, NZ). Herding behaviors most often involved dolphins swimming around the side or under prey balls, but dolphins in Argentina more often swam under prey balls (48% of passes) than did dolphins in NZ (34% of passes). This result may have been due to differences in group sizes between sites, since groups are larger in Argentina. Additionally, in NZ, group size was positively correlated with proportion of passes that occurred under prey balls (pdolphins in Argentina more often swam through prey balls (8% of attempts) than did dolphins in NZ (4% of attempts). This result may have been due to differences in prey ball sizes between sites, since dolphins fed on larger prey balls in Argentina (>74m(2)) than in NZ (maximum 33m(2)). Additionally, in NZ, dolphins were more likely to swim through prey balls to capture fish when they fed on larger prey balls (p=0.025). Copyright © 2013 Elsevier B.V. All rights reserved.

The Size Distribution of Stardust Injected into the ISM

Science.gov (United States)

Krueger, D.; Sedlmayr, E.

1996-01-01

A multi-component method for the description of the evolution of the grain size distribution in consideration of a size dependent grain drift and growth rate is applied in order to model dust driven winds around cool C-stars. Grain drift introduces several modifications concerning dust growth: on one hand the residence time in the region of efficient growth is reduced, on the other hand the growth efficiency is higher due to an increased collisional rate. For carbon grains the surface density of radical sites is increased, but on the other hand there is a reduction of the sticking efficiency of the growth species for drift velocities larger than a few km/s. It is found that the consideration of drift results in a considerable distortion of the size distribution as compared to the case of zero drift velocity. Generally, there are less, but larger grains if drift is included.

Effects of Meaning and Symmetry on Judgments of Size

DEFF Research Database (Denmark)

Reber, Rolf; Christensen, Bo T.; Meier, Beat

2014-01-01

to be judged as larger than asymmetric numbers (e.g., 43). However, recent research found that symmetric numbers were judged to be smaller than asymmetric numbers. This finding suggests that the mechanisms underlying size judgments may differ in meaningful and meaningless materials. Supporting this notion, we...... showed in Experiment 1 that meaning increased judged size, whereas symmetry decreased judged size. In the next two experiments, we excluded several alternative explanations for the differences in size judgments between meaningful and meaningless materials in earlier studies. This finding contradicts...

Introgression of a Rare Haplotype from Southeastern Africa to Breed California Blackeyes with Larger Seeds

Directory of Open Access Journals (Sweden)

Mitchell R Lucas

2015-03-01

Full Text Available Seed size distinguishes most crops from their wild relatives and is an important quality trait for the grain legume cowpea. In order to breed cowpea varieties with larger seeds we introgressed a rare haplotype associated with large seeds at the Css-1 locus from an African buff seed type cultivar, IT82E-18 (18.5g/100 seeds, into a blackeye seed type cultivar, CB27 (22g/100 seed. Four RILs derived from these two parents were chosen for marker-assisted breeding based on SNP genotyping with a goal of stacking large seed haplotypes into a CB27 background. Foreground and background selection were performed during two cycles of backcrossing based on genome-wide SNP markers. The average seed size of introgression lines homozygous for haplotypes associated with large seeds was 28.7g/100 seed and 24.8g/100 seed for cycles 1 and 2, respectively. One cycle 1 introgression line with desirable seed quality was selfed for two generations to make families with very large seeds (28-35g/100 seeds. Field-based performance trials helped identify breeding lines that not only have large seeds but are also desirable in terms of yield, maturity, and plant architecture when compared to industry standards. A principal component analysis was used to explore the relationships between the parents relative to a core set of landraces and improved varieties based on high-density SNP data. The geographic distribution of haplotypes at the Css-1 locus suggest the haplotype associated with large seeds is unique to accessions collected from Southeastern Africa. Therefore this QTL has a strong potential to develop larger seeded varieties for other growing regions which is demonstrated in this work using a California pedigree.

Reestablishment of radiographic kidney size in Miniature Schnauzer dogs.

Science.gov (United States)

Sohn, Jungmin; Yun, Sookyung; Lee, Jeosoon; Chang, Dongwoo; Choi, Mincheol; Yoon, Junghee

2017-01-10

Kidney size may be altered in renal diseases, and the detection of kidney size alteration has diagnostic and prognostic values. We hypothesized that radiographic kidney size, the kidney length to the second lumbar vertebra (L2) length ratio, in normal Miniature Schnauzer dogs may be overestimated due to their shorter vertebral length. This study was conducted to evaluate radiographic and ultrasonographic kidney size and L2 length in clinically normal Miniature Schnauzers and other dog breeds to evaluate the effect of vertebral length on radiographic kidney size and to reestablish radiographic kidney size in normal Miniature Schnauzers. Abdominal radiographs and ultrasonograms from 49 Miniature Schnauzers and 54 other breeds without clinical evidence of renal disease and lumbar vertebral abnormality were retrospectively evaluated. Radiographic kidney size, in the Miniature Schnauzer (3.31 ± 0.26) was significantly larger than that in other breeds (2.94 ± 0.27). Relative L2 length, the L2 length to width ratio, in the Miniature Schnauzer (1.11 ± 0.06) was significantly shorter than that in other breeds (1.21 ± 0.09). However, ultrasonographic kidney sizes, kidney length to aorta diameter ratios, were within or very close to normal range both in the Miniature Schnauzer (6.75 ± 0.67) and other breeds (7.16 ± 1.01). Thus, Miniature Schnauzer dogs have breed-specific short vertebrae and consequently a larger radiographic kidney size, which was greater than standard reference in normal adult dogs. Care should be taken when evaluating radiographic kidney size in Miniature Schnauzers to prevent falsely diagnosed renomegaly.

Sexual dimorphism in size, age, maturation, and growth characteristics of boarfish (Capros aper) in the Northeast Atlantic

DEFF Research Database (Denmark)

Hüssy, Karin; Coad, Julie Olivia; Farrell, Edward D.

2012-01-01

Sexual dimorphism in size, age, maturation, and growth characteristics of boarfish (Capros aper) in the Northeast Atlantic – ICES Journal of Marine Science, 69: 1729–1735.Boarfish (Capros aper) have, in recent years, become of increasing commercial importance due to their apparent increase...... stock with sexual dimorphism, where females are, on average, larger than males. No seasonal effects occur in size distribution and sex ratio, indicating that females and males stay together in shoals throughout the year. Females become increasingly dominant in abundance at larger sizes and older ages...... in abundance in the Northeast Atlantic. This study presents detailed biological information relevant to understanding stock structure and dynamics. Boarfish are a long-lived species that reach a maximum age of >30 years. The size distribution is skewed towards larger sizes, as expected from an unexploited...

Plasticity in sexual size dimorphism and Rensch's rule in Mediterranean blennies (Blenniidae)

NARCIS (Netherlands)

Lengkeek, W.; Didderen, K.; Cote, I. M.; van der Zee, E. M.; Snoek, R. C.; Reynolds, J. D.

2008-01-01

Comparative analyses of sexual size dimorphism (SSD) across species have led to the discovery of Rensch's rule. This rule states that SSD increases with body size when males are the largest sex, but decreases with increasing size when females are larger. Within-species comparisons of SSD in fish are

The impact of death awareness on sizes of self-representational objects.

Science.gov (United States)

McCabe, Simon; Vail, Kenneth E; Arndt, Jamie

2018-01-01

People seem to have a tendency to increase the relative size of self-representational objects. Prior research suggests that motivational factors may fuel that tendency, so the present research built from terror management theory to examine whether existential motivations - engendered by concerns about death - may have similar implications for self-relevant size biases. Specifically, across two studies (total N = 288), we hypothesized that reminders of death would lead participants to inflate the size of self-representational objects. Both studies suggested that relative to reminders of pain, mortality salience led participants to construct larger clay sculptures of themselves (vs. others; Study 1) and a larger ostensible video game avatar for the self (vs. others; Study 2). © 2017 The British Psychological Society.

Sexual selection on male size drives the evolution of male-biased sexual size dimorphism via the prolongation of male development.

Science.gov (United States)

Rohner, Patrick T; Blanckenhorn, Wolf U; Puniamoorthy, Nalini

2016-06-01

Sexual size dimorphism (SSD) arises when the net effects of natural and sexual selection on body size differ between the sexes. Quantitative SSD variation between taxa is common, but directional intraspecific SSD reversals are rare. We combined micro- and macroevolutionary approaches to study geographic SSD variation in closely related black scavenger flies. Common garden experiments revealed stark intra- and interspecific variation: Sepsis biflexuosa is monomorphic across the Holarctic, while S. cynipsea (only in Europe) consistently exhibits female-biased SSD. Interestingly, S. neocynipsea displays contrasting SSD in Europe (females larger) and North America (males larger), a pattern opposite to the geographic reversal in SSD of S. punctum documented in a previous study. In accordance with the differential equilibrium model for the evolution of SSD, the intensity of sexual selection on male size varied between continents (weaker in Europe), whereas fecundity selection on female body size did not. Subsequent comparative analyses of 49 taxa documented at least six independent origins of male-biased SSD in Sepsidae, which is likely caused by sexual selection on male size and mediated by bimaturism. Therefore, reversals in SSD and the associated changes in larval development might be much more common and rapid and less constrained than currently assumed. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Does wine glass size influence sales for on-site consumption? A multiple treatment reversal design

Directory of Open Access Journals (Sweden)

Rachel Pechey

2016-06-01

Full Text Available Abstract Background Wine glass size can influence both perceptions of portion size and the amount poured, but its impact upon purchasing and consumption is unknown. This study aimed to examine the impact of wine glass size on wine sales for on-site consumption, keeping portion size constant. Methods In one establishment (with separate bar and restaurant areas in Cambridge, England, wine glass size (Standard; Larger; Smaller was changed over eight fortnightly periods. The bar and restaurant differ in wine sales by the glass vs. by the bottle (93 % vs. 63 % by the glass respectively. Results Daily wine volume purchased was 9.4 % (95 % CI: 1.9, 17.5 higher when sold in larger compared to standard-sized glasses. This effect seemed principally driven by sales in the bar area (bar: 14.4 % [3.3, 26.7]; restaurant: 8.2 % [−2.5, 20.1]. Findings were inconclusive as to whether sales were different with smaller vs. standard-sized glasses. Conclusions The size of glasses in which wine is sold, keeping the portion size constant, can affect consumption, with larger glasses increasing consumption. The hypothesised mechanisms for these differential effects need to be tested in a replication study. If replicated, policy implications could include considering glass size amongst alcohol licensing requirements. Trial registration ISRCTN registry: ISRCTN12018175 . Registered 12th May 2015.

Cultural constructions of "obesity": understanding body size, social class and gender in Morocco.

Science.gov (United States)

Batnitzky, Adina K

2011-01-01

This article presents data from an in-depth qualitative study of overweight and diabetic women in Morocco, a North African country experiencing a rapid increase in obesity according to national statistics. This case study explores the heterogeneous relationship among health, culture and religion in Morocco by highlighting the relationship between the intricacies of women's everyday lives and their body sizes. My findings suggest that although the Body Mass Index (BMI) of adult women has been documented to have increased in Morocco along with other macroeconomic changes (i.e., increases in urbanization, etc.), "obesity" has yet to be universally medicalized in the Moroccan context. As such women do not generally utilize a medicalized concept of obesity in reference to their larger body sizes. Rather, cultural constructions of "obesity" are understood through cultural understandings of a larger body size, religious beliefs about health and illness, and the nature of women's religious participation. This stands in contrast to dominant accounts about the region that promote an overall veneration of a larger body size for women. Copyright © 2010 Elsevier Ltd. All rights reserved.

Estimating Search Engine Index Size Variability

DEFF Research Database (Denmark)

Van den Bosch, Antal; Bogers, Toine; De Kunder, Maurice

2016-01-01

One of the determining factors of the quality of Web search engines is the size of their index. In addition to its influence on search result quality, the size of the indexed Web can also tell us something about which parts of the WWW are directly accessible to the everyday user. We propose a novel...... method of estimating the size of a Web search engine’s index by extrapolating from document frequencies of words observed in a large static corpus of Web pages. In addition, we provide a unique longitudinal perspective on the size of Google and Bing’s indices over a nine-year period, from March 2006...... until January 2015. We find that index size estimates of these two search engines tend to vary dramatically over time, with Google generally possessing a larger index than Bing. This result raises doubts about the reliability of previous one-off estimates of the size of the indexed Web. We find...

Determination of Flaw Size from Thermographic Data

Science.gov (United States)

Winfree, William P.; Howell, Patricia A.; Zalameda, Joseph N.

2014-01-01

Conventional methods for reducing the pulsed thermographic responses of delaminations tend to overestimate the size of the flaw. Since the heat diffuses in the plane parallel to the surface, the resulting temperature profile over the flaw is larger than the flaw. A variational method is presented for reducing the thermographic data to produce an estimated size for the flaw that is much closer to the true size of the flaw. The size is determined from the spatial thermal response of the exterior surface above the flaw and a constraint on the length of the contour surrounding the flaw. The technique is applied to experimental data acquired on a flat bottom hole composite specimen.

Pre-thymic somatic mutation leads to high mutant frequency at hypoxanthine-guanine phosphoribosyltransferase gene

Energy Technology Data Exchange (ETDEWEB)

Jett, J. [Lawrence Livermore National Lab., CA (United States)

1994-12-01

While characterizing the background mutation spectrum of the Hypoxathine-guanine phosphoribosyltransferase (HPRT) gene in a healthy population, an outlier with a high mutant frequency of thioguanine resistant lymphocytes was found. When studied at the age of 46, this individual had been smoking 60 cigarettes per day for 38 years. His mutant frequency was calculated at 3.6 and 4.2x10{sup {minus}4} for two sampling periods eight months apart. Sequencing analysis of the HPRT gene in his mutant thioguanine resistant T lymphocytes was done to find whether the cells had a high rate of mutation, or if the mutation was due to a single occurrence of mutation and, if so, when in the T lymphocyte development the mutation occurred. By T-cell receptor analysis it has been found that out of 35 thioguanine resistant clones there was no dominant gamma T cell receptor gene rearrangement. During my appointment in the Science & Engineering Research Semester, I found that 34 of those clones have the same base substitution of G{yields}T at cDNA position 197. Due to the consistent mutant frequency from both sampling periods and the varying T cell receptors, the high mutant frequency cannot be due to recent proliferation of a mature mutant T lymphocyte. From the TCR and DNA sequence analysis we conclude that the G{yields}T mutation must have occurred in a T lymphocyte precursor before thymic differentiation so that the thioguanine resistant clones share the same base substitution but not the same gamma T cell receptor gene.

Breaking Haller's rule: brain-body size isometry in a minute parasitic wasp.

NARCIS (Netherlands)

Woude, van der E.; Smid, H.M.; Chittka, L.; Huigens, M.E.

2013-01-01

Throughout the animal kingdom, Haller's rule holds that smaller individuals have larger brains relative to their body than larger-bodied individuals. Such brain-body size allometry is documented for all animals studied to date, ranging from small ants to the largest mammals. However, through

Depicted serving size: cereal packaging pictures exaggerate serving sizes and promote overserving.

Science.gov (United States)

Tal, Aner; Niemann, Stina; Wansink, Brian

2017-02-06

Extensive work has focused on the effects of nutrition label information on consumer behavior on the one hand, and on the effects of packaging graphics on the other hand. However, little work has examined how serving suggestion depictions - graphics relating to serving size - influence the quantity consumers serve themselves. The current work examines the prevalence of exaggerated serving size depictions on product packaging (study 1) and its effects on food serving in the context of cereal (study 2). Study 1 was an observational field survey of cereal packaging. Study 2 was a mixed experimental cross-sectional design conducted at a U.S. university, with 51 student participants. Study 1 coded 158 US breakfast cereals and compared the serving sizes depicted on the front of the box with the suggested serving size stated on the nutrition facts panel. Study 2 measured the amount of cereal poured from exaggerated or accurate serving size depictions. Study 1 compared average servings via t-tests. Study 2 used a mixed model with cereal type as the repeated measure and a compound symmetry covariance matrix. Study 1 demonstrated that portion size depictions on the front of 158 cereal boxes were 65.84% larger (221 vs. 134 calories) than the recommended portions on nutrition facts panels of those cereals. Study 2 showed that boxes that depicted exaggerated serving sizes led people to pour 20% more cereal compared to pouring from modified boxes that depicted a single-size portion of cereal matching suggested serving size. This was 45% over the suggested serving size. Biases in depicted serving size depicted on cereal packaging are prevalent in the marketplace. Such biases may lead to overserving, which may consequently lead to overeating. Companies should depict the recommended serving sizes, or otherwise indicate that the depicted portion represents an exaggerated serving size.

Depicted serving size: cereal packaging pictures exaggerate serving sizes and promote overserving

Directory of Open Access Journals (Sweden)

Aner Tal

2017-02-01

Full Text Available Abstract Background Extensive work has focused on the effects of nutrition label information on consumer behavior on the one hand, and on the effects of packaging graphics on the other hand. However, little work has examined how serving suggestion depictions - graphics relating to serving size - influence the quantity consumers serve themselves. The current work examines the prevalence of exaggerated serving size depictions on product packaging (study 1 and its effects on food serving in the context of cereal (study 2. Methods Study 1 was an observational field survey of cereal packaging. Study 2 was a mixed experimental cross-sectional design conducted at a U.S. university, with 51 student participants. Study 1 coded 158 US breakfast cereals and compared the serving sizes depicted on the front of the box with the suggested serving size stated on the nutrition facts panel. Study 2 measured the amount of cereal poured from exaggerated or accurate serving size depictions. Study 1 compared average servings via t-tests. Study 2 used a mixed model with cereal type as the repeated measure and a compound symmetry covariance matrix. Results Study 1 demonstrated that portion size depictions on the front of 158 cereal boxes were 64.7% larger (221 vs. 134 calories than the recommended portions on nutrition facts panels of those cereals. Study 2 showed that boxes that depicted exaggerated serving sizes led people to pour 17.8% more cereal compared to pouring from modified boxes that depicted a single-size portion of cereal matching suggested serving size. This was 42% over the suggested serving size. Conclusions Biases in depicted serving size depicted on cereal packaging are prevalent in the marketplace. Such biases may lead to overserving, which may consequently lead to overeating. Companies should depict the recommended serving sizes, or otherwise indicate that the depicted portion represents an exaggerated serving size.

7 CFR 52.1851 - Sizes of raisins with seeds-layer or cluster.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Sizes of raisins with seeds-layer or cluster. 52.1851...-Raisins with Seeds § 52.1851 Sizes of raisins with seeds—layer or cluster. The size of Layer or Cluster... measurement as applicable to layer or cluster raisins with seeds are: (a) 3 Crown size or larger. “3 Crown...

Sequential mutations in Notch1, Fbxw7, and Tp53 in radiation-induced mouse thymic lymphomas.

Science.gov (United States)

Jen, Kuang-Yu; Song, Ihn Young; Banta, Karl Luke; Wu, Di; Mao, Jian-Hua; Balmain, Allan

2012-01-19

T-cell acute lymphoblastic lymphomas commonly demonstrate activating Notch1 mutations as well as mutations or deletions in Fbxw7. However, because Fbxw7 targets Notch1 for degradation, genetic alterations in these genes are expected to be mutually exclusive events in lymphomagenesis. Previously, by using a radiation-induced Tp53-deficient mouse model for T-cell acute lymphoblastic lymphoma, we reported that loss of heterozygosity at the Fbxw7 locus occurs frequently in a Tp53-dependent manner. In the current study, we show that these thymic lymphomas also commonly exhibit activating Notch1 mutations in the proline-glutamic acid-serine-threonine (PEST) domain. Moreover, concurrent activating Notch1 PEST domain mutations and single-copy deletions at the Fbxw7 locus occur with high frequency in the same individual tumors, indicating that these changes are not mutually exclusive events. We further demonstrate that although Notch1 PEST domain mutations are independent of Tp53 status, they are completely abolished in mice with germline Fbxw7 haploinsufficiency. Therefore, Notch1 PEST domain mutations only occur when Fbxw7 expression levels are intact. These data suggest a temporal sequence of mutational events involving these important cancer-related genes, with Notch1 PEST domain mutations occurring first, followed by Fbxw7 deletion, and eventually by complete loss of Tp53.

Comparison of feeding behavior between two different-sized groups of Japanese macaques (Macaca fuscata yakui).

Science.gov (United States)

Kurihara, Yosuke; Hanya, Goro

2015-05-13

Group-living animals face intragroup scramble and intergroup contest competitions. Many studies have shown that larger groups bear the costs of intragroup scramble competition, which negatively affects the reproductive success of females. Unlike most primate species, Japanese macaques in the Yakushima coastal forest show increased reproductive success with group size. However, it remains unclear how group size affects the behavior of macaques. The present study examined the effects of group size on the feeding behavior of Japanese macaques in the Yakushima coastal forest. We investigated 9-13 adult females from two different-sized groups via focal animal sampling during October 2012-August 2013. We compared the feeding behavior, including patch use, between the two groups. The larger group had a larger home range and spent more time feeding, especially on mature leaves. This suggests that intragroup feeding competition should be more intense in the larger group than in the smaller group. The feeding of mature leaves might enable the larger group to increase the number of co-feeding individuals. Contrary to the predictions that the larger group travels longer distances and spends more time moving, the smaller group traveled longer distances, and spent more time moving, although the number of visited patches did not differ between the two groups. The immediate consequences of the loss of inter-group encounters could accumulate as daily travel costs, considering that group size is associated with inter-group dominance and that intergroup aggressive encounters occur frequently in the Yakushima coastal forest. This suggests that the smaller group has increased travel costs as a result of intergroup contest competition, which leads to decline in reproductive success. Am. J. Primatol. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Age- and size-dependent mating performance and fertility in a pelagic copepod, Temora longicornis

DEFF Research Database (Denmark)

Sichlau, Mie Hylstofte; Kiørboe, Thomas

2011-01-01

Prepress abstract: In many species, size and age have been shown to be strong determinants of the reproductive success for both sexes. Here we examine age- and size dependent reproductive performance (egg- and sperm production, mating success) in a pelagic copepod. Compared to smaller males, larger...... males produce larger spermatophores containing more spermatozoa, and fertilize a larger fraction of available females. Females mating with large males produce more offspring than those mating with small males. Similarly, large females have higher egg production rates as well as a higher life-time egg...... fertilize females for only about eight days after they mature. The strong size- and age-dependent fertility observed in this species is conducive to the development of sexual selection via mate choice for young and large partners, as has been shown in one other copepod species...

Import Penetration, Export Orientation and Plant Size in Indonesian Manufacturing

OpenAIRE

Sadayuki TAKII

2014-01-01

This paper empirically examines differential impacts of globalisation on plant size among plants with different characteristics, including initial plant size, import and export status, and ownership. After accounting for other characteristics, results of this analysis suggest that both import penetration and export orientation do not have differential impacts on the size of larger and smaller plants. This is contrary to fears that only relatively large plants can benefit from globalisation wh...

Prognostic Importance of Small Prostate Size in Men Receiving Definitive Prostate Brachytherapy

International Nuclear Information System (INIS)

Taira, Al V.; Merrick, Gregory S.; Galbreath, Robert W.; Butler, Wayne M.; Adamovich, Edward; Wallner, Kent E.

2012-01-01

Purpose: To assess whether small prostate size is an adverse prognostic factor in men undergoing brachytherapy in the same manner in which it seems to be for men undergoing radical prostatectomy. Methods and Materials: From April 1995 to June 2008, 2024 patients underwent brachytherapy by a single brachytherapist. Median follow-up was 7.4 years. The role of small prostate size (≤20 cm 3 ) as a prognostic factor for biochemical progression-free survival, cause-specific survival, and all-cause mortality was investigated. The differences in survival between men with small and larger prostates were compared using Kaplan-Meier curves and log-rank tests. Results: Median prostate size for the entire cohort was 32.7 cm 3 . For the 167 men with small prostates, median prostate size was 17.4 cm 3 . There was no difference in biochemical progression-free survival (95.2% vs 96.2%, P=.603), cause-specific survival (97.7% vs 98.3%, P=.546), or all-cause mortality (78.0% vs 77.2%, P=.838) at 10 years for men with small prostates compared with men with larger prostates. On univariate and multivariate analysis, small prostate size was not associated with any of the primary outcome measures. Conclusion: Men with small prostates treated with brachytherapy have excellent outcomes and are at no higher risk of treatment failure than men with larger glands. High-quality implants with adequate margins seem sufficient to address the increased adverse risk factors associated with small prostate size.

Big bees do a better job: intraspecific size variation influences pollination effectiveness

Directory of Open Access Journals (Sweden)

Pat Willmer

2014-09-01

Full Text Available 1. Bumblebees (Bombus spp. are efficient pollinators of many flowering plants, yet the pollen deposition performance of individual bees has not been investigated. Worker bumblebees exhibit large intraspecific and intra-nest size variation, in contrast with other eusocial bees; and their size influences collection and deposition of pollen grains. 2. Laboratory studies with B. terrestris workers and Vinca minor flowers showed that pollination effectiveness PE, as measured from pollen grains deposited on stigmas in single visits (SVD, was significantly positively related to bee size; larger bees deposited more grains, while the smallest individuals, with proportionally shorter tongues, were unable to collect or deposit pollen in these flowers. Individuals did not increase their pollen deposition over time, so handling experience does not influence SVD in Vinca minor. 3. Field studies using Geranium sanguineum and Echium vulgare, and multiple visiting species, confirmed that individual size affects SVD. All bumblebee species showed positive SVD/size effects, though even the smallest individuals did deposit pollen. Apis with its limited size variation showed no such detectable effect when visiting Geranium flowers. Two abundant hoverfly species also showed size effects, particularly when feeding for nectar on Echium. 4. Mean size of foragers also varied diurnally, with larger individuals active earlier and later, so that pollination effectiveness varies through a day; flowers routinely pollinated by bees may best be served by early morning dehiscence and visits from larger individuals. 5. Thus, while there are well-documented species-level variations in pollination effectiveness, the fine-scale individual differences between foragers should also be taken into account when assessing the reproductive outputs of biotically-pollinated plants.

Effect of meal size and body size on specific dynamic action and gastric processing in decapod crustaceans.

Science.gov (United States)

McGaw, Iain J; Curtis, Daniel L

2013-11-01

Meal size and animal size are important factors affecting the characteristics of the specific dynamic action (SDA) response across a variety of taxa. The effects of these two variables on the SDA of decapod crustaceans are based on just a couple of articles, and are not wholly consistent with the responses reported for other aquatic ectotherms. Therefore, the effects of meal size and animal size on the characteristics of SDA response were investigated in a variety of decapod crustaceans from different families. A 6 fold increase in meal size (0.5%-3% body mass) resulted a pronounced increase in the duration of increased oxygen consumption, resulting in an increase in the SDA of Callinectes sapidus, Cancer gracilis, Hemigrapsus nudus, Homarus americanus, Pugettia producta and Procambarus clarkii. Unlike many other aquatic ectotherms a substantial increase between meal sizes was required, with meal size close to their upper feeding limit (3% body mass), before changes were evident. In many organisms increases in both duration and scope contribute to the overall SDA, here changes in scope as a function of meal size were weak, suggesting that a similar amount of energy is required to upregulate gastric processes, regardless of meal size. The SDA characteristics were less likely to be influenced by the size of the animal, and there was no difference in the SDA (kJ) as a function of size in H. americanus or Cancer irroratus when analysed as mass specific values. In several fish species characteristics of the SDA response are more closely related to the transit times of food, rather than the size of a meal. To determine if a similar trend occurred in crustaceans, the transit rates of different sized meals were followed through the digestive system using a fluoroscope. Although there was a trend towards larger meals taking longer to pass through the gut, this was only statistically significant for P. clarkii. There were some changes in transit times as a function of animal

THE MASSIVE SATELLITE POPULATION OF MILKY-WAY-SIZED GALAXIES

International Nuclear Information System (INIS)

Rodríguez-Puebla, Aldo; Avila-Reese, Vladimir; Drory, Niv

2013-01-01

Several occupational distributions for satellite galaxies more massive than m * ≈ 4 × 10 7 M ☉ around Milky-Way (MW)-sized hosts are presented and used to predict the internal dynamics of these satellites as a function of m * . For the analysis, a large galaxy group mock catalog is constructed on the basis of (sub)halo-to-stellar mass relations fully constrained with currently available observations, namely the galaxy stellar mass function decomposed into centrals and satellites, and the two-point correlation functions at different masses. We find that 6.6% of MW-sized galaxies host two satellites in the mass range of the Small and Large Magellanic Clouds (SMC and LMC, respectively). The probabilities of the MW-sized galaxies having one satellite equal to or larger than the LMC, two satellites equal to or larger than the SMC, or three satellites equal to or larger than Sagittarius (Sgr) are ≈0.26, 0.14, and 0.14, respectively. The cumulative satellite mass function of the MW, N s (≥m * ) , down to the mass of the Fornax dwarf is within the 1σ distribution of all the MW-sized galaxies. We find that MW-sized hosts with three satellites more massive than Sgr (as the MW) are among the most common cases. However, the most and second most massive satellites in these systems are smaller than the LMC and SMC by roughly 0.7 and 0.8 dex, respectively. We conclude that the distribution N s (≥m * ) for MW-sized galaxies is quite broad, the particular case of the MW being of low frequency but not an outlier. The halo mass of MW-sized galaxies correlates only weakly with N s (≥m * ). Then, it is not possible to accurately determine the MW halo mass by means of its N s (≥m * ); from our catalog, we constrain a lower limit of 1.38 × 10 12 M ☉ at the 1σ level. Our analysis strongly suggests that the abundance of massive subhalos should agree with the abundance of massive satellites in all MW-sized hosts, i.e., there is not a missing (massive) satellite problem

Investigation of active vibration drilling using acoustic emission and cutting size analysis

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Yingjian Xiao

2018-04-01

Full Text Available This paper describes an investigation of active bit vibration on the penetration mechanisms and bit-rock interaction for drilling with a diamond impregnated coring bit. A series of drill-off tests (DOTs were conducted where the drilling rate-of-penetration (ROP was measured at a series of step-wise increasing static bit thrusts or weight-on-bits (WOBs. Two active DOTs were conducted by applying 60 Hz axial vibration at the bit-rock interface using an electromagnetic vibrating table mounted underneath the drilling samples, and a passive DOT was conducted where the bit was allowed to vibrate naturally with lower amplitude due to the compliance of the drilling sample mountings. During drilling, an acoustic emission (AE system was used to record the AE signals generated by the diamond cutter penetration and the cuttings were collected for grain size analysis. The instrumented drilling system recorded the dynamic motions of the bit-rock interface using a laser displacement sensor, a load cell, and an LVDT (linear variable differential transformer recorded the dynamic WOB and the ROP, respectively. Calibration with the drilling system showed that rotary speed was approximately the same at any given WOB, facilitating comparison of the results at the same WOB. Analysis of the experimental results shows that the ROP of the bit at any given WOB increased with higher amplitude of axial bit-rock vibration, and the drill cuttings increased in size with a higher ROP. Spectral analysis of the AEs indicated that the higher ROP and larger cutting size were correlated with a higher AE energy and a lower AE frequency. This indicated that larger fractures were being created to generate larger cutting size. Overall, these results indicate that a greater magnitude of axial bit-rock vibration produces larger fractures and generates larger cuttings which, at the same rotary speed, results in a higher ROP. Keywords: Active bit vibration, Diamond coring drilling, Drill

Sample size determination for mediation analysis of longitudinal data.

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Pan, Haitao; Liu, Suyu; Miao, Danmin; Yuan, Ying

2018-03-27

Sample size planning for longitudinal data is crucial when designing mediation studies because sufficient statistical power is not only required in grant applications and peer-reviewed publications, but is essential to reliable research results. However, sample size determination is not straightforward for mediation analysis of longitudinal design. To facilitate planning the sample size for longitudinal mediation studies with a multilevel mediation model, this article provides the sample size required to achieve 80% power by simulations under various sizes of the mediation effect, within-subject correlations and numbers of repeated measures. The sample size calculation is based on three commonly used mediation tests: Sobel's method, distribution of product method and the bootstrap method. Among the three methods of testing the mediation effects, Sobel's method required the largest sample size to achieve 80% power. Bootstrapping and the distribution of the product method performed similarly and were more powerful than Sobel's method, as reflected by the relatively smaller sample sizes. For all three methods, the sample size required to achieve 80% power depended on the value of the ICC (i.e., within-subject correlation). A larger value of ICC typically required a larger sample size to achieve 80% power. Simulation results also illustrated the advantage of the longitudinal study design. The sample size tables for most encountered scenarios in practice have also been published for convenient use. Extensive simulations study showed that the distribution of the product method and bootstrapping method have superior performance to the Sobel's method, but the product method was recommended to use in practice in terms of less computation time load compared to the bootstrapping method. A R package has been developed for the product method of sample size determination in mediation longitudinal study design.

Is Parental Involvement Lower at Larger Schools?

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Walsh, Patrick

2010-01-01

Parents who volunteer, or who lobby for improvements in school quality, are generally seen as providing a school-wide public good. If so, straightforward public-good theory predicts that free-riding will reduce average involvement at larger schools. This study uses longitudinal data to follow families over time, as their children move from middle…

Mother-Offspring Relations: Prey Quality and Maternal Size Affect Egg Size of an Acariphagous Lady Beetle in Culture

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Eric W. Riddick

2012-01-01

Full Text Available We investigated mother-offspring relations in a lady beetle Stethorus punctillum Weise that utilizes spider mites as prey. Our objectives were to determine if (1 prey quality affects egg size, (2 maternal size correlates with egg size, and (3 egg size affects hatching success. We fed predators spider mites Tetranychus urticae Koch from lima bean Phaseolus lunatus L. foliage in the laboratory. Mothers of unknown body size offered high rather than low quality spider mites since birth produced larger eggs. Mothers of known body size offered only high quality spider mites, produced eggs of variable size, but mean egg size correlated positively with hind femur length. Mothers laid their eggs singly, rather than in batches, and eggs were large relative to femur size. Egg size did not affect hatch success; mean hatch rate exceeded 95% regardless of egg size. In conclusion, the quality of prey consumed by S. punctillum mothers while in the larval stage can affect their size as adults and, consequently, the size of their eggs. The behavior of laying eggs singly, the positive relationship between maternal size and mean egg size, and the high rate of egg hatch suggest that S. punctillum mothers invest heavily in offspring.

From the point-of-purchase perspective: a qualitative study of the feasibility of interventions aimed at portion-size.

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Vermeer, Willemijn M; Steenhuis, Ingrid H M; Seidell, Jacob C

2009-04-01

Food portion-sizes might be a promising starting point for interventions targeting obesity. The purpose of this qualitative study was to assess how representatives of point-of-purchase settings perceived the feasibility of interventions aimed at portion-size. Semi-structured interviews were conducted with 22 representatives of various point-of-purchase settings. Constructs derived from the diffusion of innovations theory were incorporated into the interview guide. Each interview was recorded and transcribed verbatim. Data were coded and analysed with Atlas.ti 5.2 using the framework approach. According to the participants, offering a larger variety of portion-sizes had the most relative advantages, and reducing portions was the most disadvantageous. The participants also considered portion-size reduction and linear pricing of portion-sizes to be risky. Lastly, a larger variety of portion-sizes, pricing strategies and portion-size labelling were seen as the most complex interventions. In general, participants considered offering a larger variety of portion-sizes, portion-size labelling and, to a lesser extent, pricing strategies with respect to portion-sizes as most feasible to implement. Interventions aimed at portion-size were seen as innovative by most participants. Developing adequate communication strategies about portion-size interventions with both decision-makers in point-of-purchase settings and the general public is crucial for successful implementation.