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Sample records for abundant myxoid stroma

  1. Malicious masquerade: myxoid melanoma.

    PubMed

    Hitchcock, M G; White, W L

    1998-08-01

    The morphological spectrum of malignant melanoma is broad. Unusual stromal changes can distract pathologists from the correct diagnosis. Fibroblastic, chondroid, osteoid, and myxoid stroma have been documented in melanomas. Myxoid melanoma is problematic--introducing carcinomas and soft tissue sarcomas into the differential diagnosis. This review examines the clinicopathologic aspects of myxoid malignant melanoma, with emphasis on its differential diagnosis. PMID:9711669

  2. Myxoid adrenal adenoma with focal pseudoglandular pattern.

    PubMed

    De Padua, Michelle; Rajagopal, V

    2008-05-01

    Adrenal cortical tumors with myxoid change are rare tumors. To our knowledge, only 22 cases have been described so far in literature, which include 13 carcinomas and 9 adenomas. A pseudoglandular pattern has been described in 9 of these tumors. We report a case of a myxoid adenoma of the left adrenal gland in a 67-year-old woman, with a focal pseudoglandular pattern involving about 20% of the studied tumor. Rest of the tumor was composed of anastomosing cords of tumor cells. Abundant myxoid stroma was present, which stained positively with alcian blue and was weakly focally positive with periodic acid Schiff. Immunophenotype was consistent with an adrenal tumor, i.e., positive for vimentin, inhibin, and melan A. Cytokeratin AE1/AE3 and chromogranin were negative. MIB-1 index was < 0.1%. PMID:18579979

  3. Myxoid Cyst

    MedlinePlus

    ... question & answer discussion forum widgets for professionals dermatology education rash and rashes clinical tools ... These cysts form in the middle aged and the elderly. Overview A myxoid cyst, also known as a digital mucous cyst or pseudocyst, is a growth usually ...

  4. Multikinase inhibitor regorafenib inhibits the growth and metastasis of colon cancer with abundant stroma.

    PubMed

    Takigawa, Hidehiko; Kitadai, Yasuhiko; Shinagawa, Kei; Yuge, Ryo; Higashi, Yukihito; Tanaka, Shinji; Yasui, Wataru; Chayama, Kazuaki

    2016-05-01

    Interaction between tumor cells and stromal cells plays an important role in the growth and metastasis of colon cancer. We previously found that carcinoma-associated fibroblasts (CAFs) expressed platelet-derived growth factor receptor-β (PDGFR-β) and that PDGFR targeted therapy using imatinib or nilotinib inhibited stromal reaction. Bone marrow-derived mesenchymal stem cells (MSCs) migrate to tumor stroma and differentiate into CAFs. A novel oral multikinase inhibitor regorafenib inhibits receptor tyrosine kinases expressed on stromal cells (vascular endothelial growth factor receptor 1-3, TIE2, PDGFR-β, and fibroblast growth factors) and tumor cells (c-KIT, RET, and BRAF). These molecules are involved in tumor growth, angiogenesis, lymphangiogenesis, and stromal activation. Therefore, we examined whether regorafenib impaired the tumor-promoting effect of CAFs/MSCs. KM12SM human colon cancer cells alone or KM12SM cells with MSCs were transplanted into the cecal wall of nude mice. Co-implantation of KM12SM cells with MSCs into the cecal wall of nude mice produced tumors with abundant stromal component and promoted tumor growth and lymph node metastasis. Single treatment with regorafenib inhibited tumor growth and metastasis by inhibiting both tumor cells and stromal reaction. This tumor-inhibitory effect of regorafenib was more obvious in tumors developed by co-implanting KM12SM cells with MSCs. Our data suggested that targeting of the tumor microenvironment with regorafenib affected tumor cell-MSC interaction, which in turn inhibited the growth and metastasis of colon cancer. PMID:26865419

  5. Paravertebral extraskeletal myxoid chondrosarcoma: a case report and review of the literature

    PubMed Central

    Farhane, Fatima Zahra; Alami, Zineb; Bouhafa, Touria; Elmazghi, Abderrahmane; Hassouni, Khalid

    2015-01-01

    The extraskeletal myxoid chondrosarcoma (CME) is a rare malignant soft tissue tumour described as a distinct clinical, histological, immunohistochemical, genetical and evolutive entity. It represents only 2.5% of soft tissue sarcomas. Its individualization is important because it has a long and indolent clinical course, and tumour-related death often occurs after a long survival period. The diagnostic key is morphological supported by immunohistochemistry and genetics t (9; 22) that allow differentiating it from other tumours with myxoid stroma and from chordoma. This report describes a patient with paravertebral extraskeletal myxoid chondrosrcoma with a high locoregional extension. PMID:26448808

  6. Primary Retroperitoneal Myxoid Liposarcomas.

    PubMed

    Setsu, Nokitaka; Miyake, Mototaka; Wakai, Susumu; Nakatani, Fumihiko; Kobayashi, Eisuke; Chuman, Hirokazu; Hiraoka, Nobuyoshi; Kawai, Akira; Yoshida, Akihiko

    2016-09-01

    Myxoid liposarcomas (MLSs) are genetically defined by the presence of DDIT3 gene fusions and most commonly arise in the extremities of young adults. Whether MLSs develop primarily in the retroperitoneum is controversial, and a recent retrospective study found no molecularly confirmed examples. Because MLSs tend to metastasize to deep soft tissues, purported examples of primary retroperitoneal lesions might represent distant metastasis, most commonly from extremities. In addition, well-differentiated or dedifferentiated liposarcomas, which are characterized by MDM2 amplifications, may exhibit prominent myxoid changes and mimic MLSs. Here, we document 5 cases of MLSs that originated in the retroperitoneum that were identified through critical clinicopathologic reevaluation. These cases accounted for 2.3% of 214 primary retroperitoneal liposarcomas and 3.2% of 156 MLSs in our database. They occurred in 3 men and 2 women with a median age of 32 years. All tumors were localized to the retroperitoneum at presentation, and no patient developed extra-abdominal recurrences during the clinical course (median, 50 mo). All 5 cases exhibited at least focal classic histologic findings. All harbored DDIT3 gene rearrangements, and none harbored MDM2 amplifications according to fluorescence in situ hybridization. This study demonstrates that primary MLSs can occur in the retroperitoneum, albeit rarely, and can be accurately diagnosed through combined clinicopathologic and molecular analysis. PMID:27158758

  7. Myxoid mesenchymal neoplasm presenting as massive arm and chest wall oedema with pleural effusion

    PubMed Central

    Pai, Vidya B; Ravilla, Rahul; Lindberg, Matthew; Steliga, Matthew; Arnaoutakis, Konstantinos

    2015-01-01

    Myxoid mesenchymal tumours are a heterogeneous group of neoplasms characterised histologically by their abundant mucoid and myxoid extracellular matrix (ECM). Encompassing a broad spectrum of clinical behaviour ranging from benign to malignant, there are more than 60 reactive and neoplastic entities currently classified under its domain. Its varied clinical and histopathologic features continue to pose a diagnostic challenge to clinicians and pathologists. Here, we describe a rare case of myxoid mesenchymal tumour presenting as oedema of the upper extremity with pleural metastasis and partial response to chemotherapy, which to the best of our knowledge has not yet been described in the literature. PMID:26635894

  8. Myxoid degeneration of appendix wall: An entity in search of identity: Report of two cases.

    PubMed

    Hakima, Laleh; Mohanty, Sambit K; Pradhan, Dinesh; Samal, Aurobinda; Pattnaik, Niharika; Turi, George K

    2015-01-01

    Myxoid degeneration of the appendix wall without accompanying acute appendicitis (AA) is rare. We report two cases of myxoid degeneration of appendix associated with appendiceal adhesions. Both the cases showed marked splitting and disruption of smooth muscle fibers of muscularis propria by abundant myxoid ground substance and dispersed degenerated hypereosinophilic myofibers with pyknotic nuclei. Scattered degenerated myocytes with vacuolated cytoplasm were also identified. Focal serosal fibrosis was observed in both cases. We reviewed other pathologic processes that involve the appendix such as fibrous obliteration, AA, and appendiceal mucinous neoplasm (AMN) and conclude that the constellations of pathologic findings described herein are unique. Nonneoplastic dissecting myxoid degeneration of the appendix muscularis propria has not been reported in the pathology literature to date. The pathologic nature of appendiceal mucinous stromal change remains unclear; however, we hypothesize that the lesion occurs as a consequence of traction related injury to the appendix. PMID:26881615

  9. Primary hepatic tumors with myxoid change: morphologically unique hepatic adenomas and hepatocellular carcinomas.

    PubMed

    Salaria, Safia N; Graham, Rondell P; Aishima, Shinichi; Mounajjed, Taofic; Yeh, Matthew M; Torbenson, Michael S

    2015-03-01

    Mucin production in primary liver neoplasms is typically interpreted as evidence for biliary differentiation. However, we have observed benign and malignant liver tumors that have abundant extracellular myxoid/mucinous material, yet have only evidence of hepatocellular differentiation. To further characterize these unusual findings, 9 cases were identified and further studied. Four cases were hepatic adenomas, whereas 5 were hepatocellular carcinomas. Extracellular myxoid/mucinous material was diffuse in 7 cases and patchy in 2 cases. The extracellular myxoid/mucinous material was typically weakly mucicarmine positive (N=6) and Alcian blue positive (N=8). All tumors were well differentiated, and none had evidence for biliary differentiation by morphology or immunohistochemistry. The hepatic adenomas arose in nondiabetic and nonobese patients. Both the hepatic adenomas and the hepatocellular carcinomas were strongly and diffusely HepPar1 positive, CK19 negative, and showed loss of LFABP protein expression. These findings indicate that extracellular myxoid/mucinous material in isolation should not be interpreted as cholangiocarcinoma. Furthermore, the unique morphology, the clinical characteristics, and the immunophenotype results suggest that myxoid hepatic adenomas and hepatocellular carcinoma may be unique tumor variants. PMID:25602798

  10. Multiple myxoid cysts secondary to occupation.

    PubMed

    Connolly, M; de Berker, D A R

    2006-05-01

    We report the case of a 50-year-old woman who presented with eight digital myxoid cysts (DMCs) involving the fingers of both hands. They developed within 12 months of the patient starting a job that involved pushing a garment into an embroidery mould, thus exerting a downward force on the fingertips. The pressure exerted from this force could have potentially damaged the joint synovial capsule, leading to rupture and loss of synovial gel, thus inducing myxoid cysts. This case suggests that DMCs may be related to occupation, and to our knowledge, this is only the second reported case of occupationally induced DMCs. PMID:16681589

  11. Giant Right Intrathoracic Myxoid Fusocellular Lipoma

    PubMed Central

    Botianu, Petre V. H.; Cerghizan, Anda Mihaela; Botianu, Alexandru M.

    2015-01-01

    Intrathoracic lipomas are rare benign tumors; their behavior is not completely clear and their surgical removal may be challenging. We report a case of a giant right intrathoracic myxoid fusocellular lipoma compressing the lung, tracheobronchial tree, and esophagus which was removed through a posterolateral thoracotomy. Complete removal resulted in resolution of the chest pain and improvement of the dyspnea, with no recurrence at 4-year follow-up. PMID:26509096

  12. Novel cell lines established from a human myxoid malignant fibrous histiocytoma arising in the uterus.

    PubMed

    Kiyozuka, Y; Nakagawa, H; Uemura, Y; Senzaki, H; Yamamoto, A; Noguchi, T; Mizuta, H; Nakanishi, K; Nakano, S; Tsubura, A

    2001-05-01

    Two cell lines (Nara-H and Nara-F) with different phenotypes were established from a myxoid MFH of the uterus. In vitro, Nara-F grew in sheets showing a storiform arrangement and Nara-H in raised colonies. Although tumors generated in nude mice shared similar morphological features of abundant myxoid tumor in Nara-H and -F, the pleomorphic component was conspicuous in Nara-F. Both cell lines produced hyaluronic-acid but CD44 was expressed only in Nara-H. Estrogen receptor alpha (ER alpha) and progesterone receptor (PgR) were detected in Nara-H. Nara-F was positive for ER beta and PgR. Among hormonal agents, the response to the anti-estrogen tamoxifen was more sensitive than progesterone agents. This report illustrates the characteristics of these newly established cell lines, and presents the possibility of an adjuvant hormonal therapy for MFH. PMID:11408058

  13. Pelvic Myxoid Leiomyoma Mass between Vagina and Rectum.

    PubMed

    AlShalabi, Omar; Alahmar, Fadi Obaied; Aljasem, Hazem; Alsaid, Bayan; AlShalabi, Abdulghani

    2016-01-01

    Leiomyomas are the most common pelvic tumors in women. About 20-30% of women older than 35 are affected. Rare conditions of leiomyomas have extrauterine locations. Myxoid degeneration is a rare type of leiomyoma degeneration. We report a case of solid-cystic myxoid leiomyoma in a 53-year-old woman complained of constipation, urinary hesitation, and malodorous vaginal discharge with palpable 17 × 12 cm mass between vagina and rectum. Regarding the inferior location of the mass, a perineal approach was used to enucleate it. This rare location has not been mentioned before. The woman was finally diagnosed by pathologists which was myxoid leiomyoma. PMID:27429825

  14. Myxoid Neurofibromas of the External Ear Canal: A Case Report.

    PubMed

    Maryam, Y K; Mohd Khairi, M D; Asmah Hanim, H

    2015-04-01

    Myxoid neurofibroma is benign tumours of perineural cell origin that arise from elements in the peripheral nervous system. We report a case of a 60-year-old female patient presented with history of right ear mass which was slowly growing. Her primary complaint was cosmetic deformity but hearing loss was also present. The mass was excised and histologically revealed a myxoid neurofibroma. To the authors' knowledge, this is the first time that a myxoid neurofibroma arising from external auditory canal is reported. It should be included in the differential diagnosis of a mass originating from this location. PMID:26162387

  15. Pelvic Myxoid Leiomyoma Mass between Vagina and Rectum

    PubMed Central

    Alahmar, Fadi Obaied; Aljasem, Hazem; Alsaid, Bayan; AlShalabi, Abdulghani

    2016-01-01

    Leiomyomas are the most common pelvic tumors in women. About 20–30% of women older than 35 are affected. Rare conditions of leiomyomas have extrauterine locations. Myxoid degeneration is a rare type of leiomyoma degeneration. We report a case of solid-cystic myxoid leiomyoma in a 53-year-old woman complained of constipation, urinary hesitation, and malodorous vaginal discharge with palpable 17 × 12 cm mass between vagina and rectum. Regarding the inferior location of the mass, a perineal approach was used to enucleate it. This rare location has not been mentioned before. The woman was finally diagnosed by pathologists which was myxoid leiomyoma. PMID:27429825

  16. Reticulated myxoid tumor of the tongue: 2 cases supporting an expanded clinical and immunophenotypic spectrum of ectomesenchymal chondromyxoid tumor of the tongue.

    PubMed

    Seo, Sang Hee; Shin, Dong Hoon; Kang, Hyun Jeong; Choi, Kyung Un; Kim, Jee Yeon; Park, Do Youn; Lee, Chang Hun; Sol, Mee Young; Lee, Jin Choon

    2010-10-01

    An ectomesenchymal chondromyxoid tumor (ECMT) is a rare neoplasm that exclusively occurs in the anterior dorsum of the tongue. The tumor consists of small round to fusiform or spindle cells with myxoid or chondroid stroma. The tumor consistently shows a positive reaction with glial fibrillary acidic protein antibodies, especially polyclonal antibodies. We report 2 cases of reticulated myxoid tumors arising in the tongue. One tumor occurred in the posterior dorsum of the tongue and another in the anterior. Both tumors showed characteristic morphology of ECMT; however, both were negative for reactions with monoclonal and polyclonal glial fibrillary acidic protein antibodies. On the basis of morphology, they are thought to be belonging to ECMT. Hence, we suggest that ECMT can show broader spectrum of clinical and immunophenotypic feature. PMID:20661118

  17. Pericardial myxoid liposarcoma in a common eland (Taurotragus oryx).

    PubMed

    Foster, A P; Johnston, P E; Duignan, P J; Schock, A

    2011-07-01

    A pericardial myxoid liposarcoma was diagnosed in a common eland (Taurotragus oryx) based on gross, microscopical and immunohistochemical findings. The pericardial and epicardial tissues were soft and uniformly thickened. Microscopically, the neoplastic mass consisted of stellate cells embedded in a myxoid matrix. These cells contained cytoplasmic vacuoles stained by oil red O. Immunohistochemical analysis showed the neoplastic cells to express vimentin and S-100. PMID:21306730

  18. [Myxoid/round cell liposarcoma of the brachial plexus].

    PubMed

    Giner, Javier; Isla, Alberto; Hernández, Borja; Nistal, Manuel

    2014-01-01

    Myxoid/round cell liposarcoma is a soft tissue sarcoma that is extremely rare in the brachial plexus. We report a case of a myxoid/round cell liposarcoma originating in the brachial plexus that was surgically resected and evolved well, with no deficit or recurrence after 2 years of follow-up. To date, there has been no other case of this sarcoma in the literature. PMID:25126709

  19. Fine needle aspiration biopsy of metastatic malignant mesothelioma with myxoid change and signet ring cells: A case report and review of the literature.

    PubMed

    Mishra, Manisha M; Farver, Carol F; Chute, Deborah J

    2016-01-01

    Malignant mesothelioma (MM) is a rare neoplasm, which is most commonly encountered in cytology through effusion specimens. Fine needle aspiration biopsy of MM, particularly the epithelioid subtype, can be a source of diagnostic difficulty and may mimic sampling of an adenocarcinoma. This is the first case report to demonstrate abundant extracellular myxoid material and numerous intracellular vacuoles, including signet ring cells, in a fine needle aspirate of metastatic MM. A review of the literature for myxoid change and vacuoles in fine needle aspiration biopsies of MM discloses that vacuoles are found in up to 35% of aspirates of MM, but myxoid change is very rare, reported in <5% of the cases. Cytologists should be aware of this rare morphologic pattern of metastatic epithelioid MM. PMID:27014364

  20. The prognostic role of desmoplastic stroma in pancreatic ductal adenocarcinoma

    PubMed Central

    Soonawalla, Zahir; Liu, Stanley; O'Neill, Eric; Mukherjee, Somnath; McKenna, W. Gillies; Muschel, Ruth; Fokas, Emmanouil

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundant desmoplastic stroma. We examined the prognostic value of stroma density and activity in patients with resectable PDAC treated with surgery and adjuvant gemcitabine-based chemotherapy. FFPE-tissue from the pancreatectomy of 145 patients was immunohistochemically stained for haematoxylin-eosin and Masson's trichrome to assess stroma density, and alpha-smooth muscle actin (αSMA) expression for activated pancreatic stellate cells. Their expression was correlated with clinicopathological characteristics as well as overall survival (OS), progression-free survival (PFS), local progression-free survival (LPFS) and distant metastases free-survival (DMFS). After a mean follow-up of 20 months (range, 2–69 months), the median OS was 21 months and the 3-year OS was 35.7%. In multivariate analysis, highly-dense stroma was an independent prognostic parameter for OS (p = 0.001), PFS (p = 0.007), LPFS (p = 0.001) and DMFS (p = 0.002), while αSMA expression lacked significance. Interestingly, highly-dense stroma retained significance for the four clinical endpoints only in early (pT1–2) but not late (pT3–4) stage tumors. Additionally, late pT-stage (pT3–4), the presence of lymph node metastases (pN+ vs pN0), perineural/neural invasion and administration of adjuvant chemotherapy also correlated with prognosis in multivariate analysis. Altogether, stroma density constitutes an independent prognostic marker in PDAC patients treated with adjuvant chemotherapy. Our findings highlight the dynamic complexity of desmoplasia and indicate that highly-dense stroma is correlated with better outcome. Further validation of the prognostic value of stroma as a biomarker and its role in PDAC patients after adjuvant chemotherapy is warranted and will be performed in a prospective study. PMID:26716653

  1. Corneal Stroma Microfibrils

    PubMed Central

    Hanlon, Samuel D.; Behzad, Ali R.; Sakai, Lynn Y.; Burns, Alan R.

    2015-01-01

    Elastic tissue was first described well over a hundred years ago and has since been identified in nearly every part of the body. In this review, we examine elastic tissue in the corneal stroma with some mention of other ocular structures which have been more thoroughly described in the past. True elastic fibers consist of an elastin core surrounded by fibrillin microfibrils. However, the presence of elastin fibers is not a requirement and some elastic tissue is comprised of non-elastin-containing bundles of microfibrils. Fibers containing a higher relative amount of elastin are associated with greater elasticity and those without elastin, with structural support. Recently it has been shown that the microfibrils, not only serve mechanical roles, but are also involved in cell signaling through force transduction and the release of TGF-β. A well characterized example of elastin-free microfibril bundles (EFMBs) is found in the ciliary zonules which suspend the crystalline lens in the eye. Through contraction of the ciliary muscle they exert enough force to reshape the lens and thereby change its focal point. It is believed that the molecules comprising these fibers do not turn-over and yet retain their tensile strength for the life of the animal. The mechanical properties of the cornea (strength, elasticity, resiliency) would suggest that EFMBs are present there as well. However, many authors have reported that, although present during embryonic and early postnatal development, EFMBs are generally not present in adults. Serial-block-face imaging with a scanning electron microscope enabled 3D reconstruction of elements in murine corneas. Among these elements were found fibers that formed an extensive network throughout the cornea. In single sections these fibers appeared as electron dense patches. Transmission electron microscopy provided additional detail of these patches and showed them to be composed of fibrils (∼10nm diameter). Immunogold evidence clearly

  2. Myxoid Malignant Fibrous Histiocytoma with Multiple Primary Sites

    PubMed Central

    Muler, Jeffrey H.; Paulino, Augusto F.; Roulston, Diane

    2002-01-01

    Malignant fibrous histiocytoma (MFH) is one of the most common types of soft tissue sarcomas in adults. The most common location of MFH are the extremities and the trunk, with the most common site for distant metastases being the lung. We describe a case with multiple synchronous sites of myxoid MFH but no lung metastases and presence of abnormalities of 19p13. PMID:18521346

  3. Stem Cells in the Limbal Stroma.

    PubMed

    Funderburgh, James L; Funderburgh, Martha L; Du, Yiqin

    2016-04-01

    The corneal stroma contains a population of mesenchymal cells subjacent to the limbal basement membrane with characteristics of adult stem cells. These 'niche cells' support limbal epithelial stem cell viability. In culture by themselves, the niche cells display a phenotype typical of mesenchymal stem cells. These stromal stem cells exhibit a potential to differentiate to multiple cell types, including keratocytes, thus providing an abundant source of these rare cells for experimental and bioengineering applications. Stromal stem cells have also shown the ability to remodel pathological stromal tissue, suppressing inflammation and restoring transparency. Because stromal stem cells can be obtained by biopsy, they offer a potential for autologous stem cell treatment for stromal opacities. This review provides an overview of the status of work on this interesting cell population. PMID:26804252

  4. Diagnostic utility of molecular investigation in extraskeletal myxoid chondrosarcoma.

    PubMed

    Benini, Stefania; Cocchi, Stefania; Gamberi, Gabriella; Magagnoli, Giovanna; Vogel, Daniela; Ghinelli, Cristina; Righi, Alberto; Picci, Piero; Alberghini, Marco; Gambarotti, Marco

    2014-05-01

    Extraskeletal myxoid chondrosarcoma is characterized by the reciprocal chromosomal translocation t(9;22) and the resultant fused gene EWS RNA-binding protein 1 and nuclear receptor subfamily 4, group A, member 3 (EWSR1-NR4A3). A second cytogenetic rearrangement t(9;17) involves the genes NR4A3 and TAF 15 RNA polymerase II, TATA box binding protein (TBP)-associated factor (TAF15). Less frequent fusion transcript variants of the NR4A3 gene, transcription factor 12 (TCF12)-NR4A3 and TRK-fused gene (TFG)-NR4A3, are associated with t(9;15) and t(9;3) respectively. The samples from 42 patients with extraskeletal myxoid chondrosarcoma were examined for the presence of EWSR1-NR4A3, TAF15-NR4A3, TCF12-NR4A3, and TFG-NR4A3 fusion transcripts by using RT-PCR. Fluorescence in situ hybridization was performed to analyze the status of EWSR1 and NR4A3 genes. The fusion transcripts were detected in 34 of 42 samples (81%); the presence of an EWSR1 or NR4A3 gene rearrangements were detected in 8 of 42 samples (19%) which had tested negative for all fusion transcripts detected by RT-PCR. Of the 34 samples evaluable for fusion transcripts, 23 yielded positive results for EWSR1-NR4A3, 10 for TAF15-NR4A3, and 1 for TCF12-NR4A3. The combination of RT-PCR and fluorescence in situ hybridization on frozen and paraffin-embedded tissue is a sensitive and specific method for molecular detection of recurrent translocations and is an important ancillary method to establish the diagnosis of extraskeletal myxoid chondrosarcoma. PMID:24508382

  5. A Case of Digital Myxoid Cyst Coexisting with Epidermal Inclusion Cyst

    PubMed Central

    Kim, Byung Soo; Jwa, Seung Wook; Suh, Sung Won; Kim, Sung Jun; Oh, Chang-Keun; Kwon, Kyung Sool

    2008-01-01

    A 62-year-old male developed a solitary asymptomatic nodule on the lateral aspect of the distal interphalangeal joint of the right great toe. Histopathologic findings demonstrated a myxoid cyst with a concomitant epidermal inclusion cyst. To the best of our knowledge, this is the first case of concurrent occurrence of digital myxoid cyst and epidermal inclusion cyst. Although the exact mechanism for developing a digital myxoid cyst and an epidermal inclusion cyst simultaneously at the same site is not explained, trauma might be a possible cause.

  6. Pancreatic cancer stroma: friend or foe?

    PubMed

    Gore, Jesse; Korc, Murray

    2014-06-16

    Pancreatic cancer desmoplasia is thought to confer biological aggressiveness. In this issue of Cancer Cell, Özdemir and colleagues and Rhim and colleagues demonstrate that targeting the stroma results in undifferentiated, aggressive pancreatic cancer that responds to checkpoint blockade or antiangiogenic therapy, uncovering a protective role by stroma in this cancer. PMID:24937454

  7. Exomic Analysis of Myxoid Liposarcomas, Synovial Sarcomas, and Osteosarcomas

    PubMed Central

    Jiao, Yuchen; Wood, Laura D.; Kinde, Isaac; Wu, Jian; Mandahl, Nils; Luo, Jinyong; Hruban, Ralph H.; Diaz, Luis A.; He, Tong-Chuan; Vogelstein, Bert; Kinzler, Kenneth W.; Mertens, Fredrik; Papadopoulos, Nickolas

    2014-01-01

    Bone and soft tissue sarcomas are a group of histologically heterogeneous and relatively uncommon tumors. To explore their genetic origins, we sequenced the exomes of 13 osteosarcomas, eight myxoid liposarcomas (MLPS), and seven synovial sarcomas (SYN). These tumors had few genetic alterations (median of 10.8). Nevertheless, clear examples of driver gene mutations were observed, including canonical mutations in TP53, PIK3CA, SETD2, AKT1, and subclonal mutation in FBXW7. Of particular interest were mutations in H3F3A, encoding the variant histone H3.3. Mutations in this gene have only been previously observed in gliomas. Loss of heterozygosity of exomic regions was extensive in osteosarcomas but rare in SYN and MLPS. These results provide intriguing nucleotide-level information on these relatively uncommon neoplasms and highlight pathways that help explain their pathogenesis. PMID:24190505

  8. [A giant myxoid leiomyoma mimicking an inguinal hernia].

    PubMed

    Huszár, Orsolya; Zaránd, Attila; Szántó, Gyöngyi; Juhász, Viktória; Székely, Eszter; Novák, András; Molnár, Béla Ákos; Harsányi, László

    2016-03-01

    Leiomyoma is a rare, smooth muscle tumour that can occur everywhere in the human body. The authors present the history of a 60-year-old female, who had a giant, Mullerian type myxoid leiomyoma in the inguinal region mimicking acute abdominal symptoms. After examination the authors removed the soft tissue mass in the right femoral region reaching down in supine position to the middle third of the leg measuring 335 × 495 × 437 mm in greatest diameters in weight 33 kg. Reconstruction of the tissue defect was performed using oncoplastic guidelines. During the follow-up time no tumour recurrence was detected and the quality of life of the patient improved significantly. PMID:26920330

  9. Tumor Stroma Manipulation By MSC.

    PubMed

    Grisendi, Giulia; Spano, Carlotta; Rossignoli, Filippo; D Souza, Naomi; Golinelli, Giulia; Fiori, Agnese; Horwitz, Edwin M; Guarneri, Valentina; Piacentini, Federico; Paolucci, Paolo; Dominici, Massimo

    2016-01-01

    Tumor stroma (TS) plays relevant roles in all steps of cancer development. We here address several fundamental aspects related with the interaction between cancer cells and their stromal counterparts. Dissecting these players is of pivotal importance to understand oncogenesis, immunoescape and drug resistance. In addition, this better comprehension will allow the introduction of novel and more effective therapeutic approaches where manipulated stromal elements may become detrimental for tumor growth. Our group and others rely on the use of multipotent mesenchymal stromal/stem cells (MSC) as anti-cancer tools, since these putative TS cell precursors can deliver potent apoptosis-inducing agents. Multimodal-armed MSC can target a variety of cancers in vitro and, when injected in vivo, they localize into tumors mediating cell death without evident toxicities to normal tissues. While several aspects of these strategies shall require further investigations, these approaches collectively indicate how TS manipulation by MSC represents a tool to influence the fate of cancer cells, creating a new generation of anti-cancer strategies. PMID:26953248

  10. Molecular analysis of the fusion of EWS to an orphan nuclear receptor gene in extraskeletal myxoid chondrosarcoma.

    PubMed Central

    Brody, R. I.; Ueda, T.; Hamelin, A.; Jhanwar, S. C.; Bridge, J. A.; Healey, J. H.; Huvos, A. G.; Gerald, W. L.; Ladanyi, M.

    1997-01-01

    The pathogenesis of myxoid chondrosarcoma (CS) is poorly understood. A recurrent translocation, t(9;22) (q22;q12), has been recognized in CS, specifically in extraskeletal myxoid CS. Recently, this translocation has been shown to represent a rearrangement of the EWS gene at 22q12 with a novel gene at 9q22 designated CHN (or TEC). Sequence analysis suggests that CHN encodes a novel orphan nuclear receptor with a zinc finger DNA-binding domain. The structure of this gene fusion has been characterized in only a limited number of extraskeletal myxoid CSs and its presence in other types of CS has not been extensively examined. We studied 46 cases of CS (8 extraskeletal myxoid, 4 skeletal myxoid, 4 mesenchymal, and 30 other) for the EWS/CHN gene fusion by reverse transcriptase polymerase chain reaction, Southern blotting, and long-range DNA polymerase chain reaction. The EWS/CHN gene fusion was present in 6 of 8 extraskeletal myxoid CSs and was not detected in any of the remaining cases, including the 4 skeletal myxoid CSs. The negative findings in the latter cases suggest that skeletal myxoid CS is pathogenetically distinct from its extraskeletal counterpart. Notably, 2 cases of extraskeletal myxoid CS showed neither an EWS/CHN fusion transcript nor EWS/CHN genomic fusion nor EWS or CHN genomic rearrangement, suggesting genetic heterogeneity within extraskeletal myxoid CS. Finally, we also provide evidence for alternative splicing of the 3' end of the fusion transcript. Extraskeletal myxoid CS thus represents yet another sarcoma type containing a gene fusion involving EWS. Images Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 PMID:9060841

  11. Regulation of Corneal Stroma Extracellular Matrix Assembly

    PubMed Central

    Chen, Shoujun; Mienaltowski, Michael J.; Birk, David E.

    2014-01-01

    The transparent cornea is the major refractive element of the eye. A finely controlled assembly of the stromal extracellular matrix is critical to corneal function, as well as in establishing the appropriate mechanical stability required to maintain corneal shape and curvature. In the stroma, homogeneous, small diameter collagen fibrils, regularly packed with a highly ordered hierarchical organization, are essential for function. This review focuses on corneal stroma assembly and the regulation of collagen fibrillogenesis. Corneal collagen fibrillogenesis involves multiple molecules interacting in sequential steps, as well as interactions between keratocytes and stroma matrix components. The stroma has the highest collagen V:I ratio in the body. Collagen V regulates the nucleation of protofibril assembly, thus controlling the number of fibrils and assembly of smaller diameter fibrils in the stroma. The corneal stroma is also enriched in small leucine-rich proteoglycans (SLRPs) that cooperate in a temporal and spatial manner to regulate linear and lateral collagen fibril growth. In addition, the fibril-associated collagens (FACITs) such as collagen XII and collagen XIV have roles in the regulation of fibril packing and inter-lamellar interactions. A communicating keratocyte network contributes to the overall and long-range regulation of stromal extracellular matrix assembly, by creating micro-domains where the sequential steps in stromal matrix assembly are controlled. Keratocytes control the synthesis of extracellular matrix components, which interact with the keratocytes dynamically to coordinate the regulatory steps into a cohesive process. Mutations or deficiencies in stromal regulatory molecules result in altered interactions and deficiencies in both transparency and refraction, leading to corneal stroma pathobiology such as stromal dystrophies, cornea plana and keratoconus. PMID:25819456

  12. Corneal Stroma Regeneration with Acellular Corneal Stroma Sheets and Keratocytes in a Rabbit Model

    PubMed Central

    Ma, Xiao Yun; Zhang, Yun; Zhu, Dan; Lu, Yang; Zhou, Guangdong; Liu, Wei; Cao, Yilin; Zhang, Wen Jie

    2015-01-01

    Acellular corneal stroma matrix has been used for corneal stroma engineering. However, because of its compact tissue structure, regrowth of keratocytes into the scaffold is difficult. Previously, we developed a sandwich model for cartilage engineering using acellular cartilage sheets. In the present study, we tested this model for corneal stroma regeneration using acellular porcine corneal stroma (APCS) sheets and keratocytes. Porcine corneas were decellularized by NaCl treatment, and the APCS was cut into 20-μm-thick sheets. A rabbit corneal stroma defect model was created by lamellar keratoplasty and repaired by transplantation of five pieces of APCS sheets with keratocytes. Six months after transplantation, transparent corneas were present in the experimental group, which were confirmed by anterior segment optical coherence tomography examination and transmittance examination. The biomechanical properties in the experimental group were similar to those of normal cornea. Histological analyses showed an even distribution of keratocytes and well-oriented matrix in the stroma layer in the experimental group. Together, these results demonstrated that the sandwich model using acellular corneal stroma sheets and keratocytes could be potentially useful for corneal stroma regeneration. PMID:26167895

  13. Emerging roles of the tumor-associated stroma in promoting tumor metastasis

    PubMed Central

    Horimoto, Yoshiya; Polanska, Urszula M.; Takahashi, Yuko; Orimo, Akira

    2012-01-01

    The stroma in human carcinomas consists of extracellular matrix and various types of non-carcinoma cells, mainly leukocytes, endothelial cells, fibroblasts, myofibroblasts and bone marrow-derived progenitors. The tumor-associated stroma actively supports tumor growth by stimulating neo-angiogenesis, as well as proliferation and invasion of apposed carcinoma cells. It has long been accepted that alterations within carcinoma cells mediate metastasis in a cell-autonomous fashion. Recent studies have, however, suggested an additional notion that cancer cells instigate local and systemic changes in the tumor microenvironment and contribute to niche formation for metastasis. Research, aiming to establish the roles of the tumor-associated stroma in facilitating the spread of carcinoma cells into distant organs, has provided an abundance of data and greater knowledge of the biology of metastatic carcinoma cells and associated stromal cells. This has stimulated further advances in the development of novel therapeutic approaches targeting tumor metastasis. PMID:22568980

  14. Unresectable Extraskeletal Myxoid Chondrosarcoma of the Neck: Early Tumor Response to Chemoradiotherapy.

    PubMed

    Zaki, Mark; Laszewski, Pam; Robinette, Natasha; Saleh, Husain; Raza, Naweed; Sukari, Ammar; Kim, Harold

    2015-01-01

    Extraskeletal myxoid chondrosarcoma (EMC) rarely occurs in the head and neck and is generally managed with primary surgery. To our knowledge, no cases of unresectable EMC of the neck have been reported. We present a case of an unresectable EMC treated with chemotherapy and radiation, and highlight the exceptional early response to therapy. PMID:26848421

  15. Unresectable Extraskeletal Myxoid Chondrosarcoma of the Neck: Early Tumor Response to Chemoradiotherapy

    PubMed Central

    Laszewski, Pam; Robinette, Natasha; Saleh, Husain; Raza, Naweed; Sukari, Ammar; Kim, Harold

    2015-01-01

    Extraskeletal myxoid chondrosarcoma (EMC) rarely occurs in the head and neck and is generally managed with primary surgery. To our knowledge, no cases of unresectable EMC of the neck have been reported. We present a case of an unresectable EMC treated with chemotherapy and radiation, and highlight the exceptional early response to therapy.  PMID:26848421

  16. Why the stroma matters in breast cancer

    PubMed Central

    Conklin, Matthew W.; Keely, Patricia J.

    2012-01-01

    Survival and recurrence rates in breast cancer are variable for common diagnoses, and therefore the biological underpinnings of the disease that determine those outcomes are yet to be fully understood. As a result, translational medicine is one of the fastest growing arenas of study in tumor biology. With advancements in genetic and imaging techniques, archived biopsies can be examined for purposes other than diagnosis. There is a great deal of evidence that points to the stroma as the major regulator of tumor progression following the initial stages of tumor formation, and the stroma may also contribute to risk factors determining tumor formation. Therefore, aspects of stromal biology are well-suited to be a focus for studies of patient outcome, where statistical differences in survival among patients provide evidence as to whether that stromal component is a signpost for tumor progression. In this review we summarize the latest research done where breast cancer patient survival was correlated with aspects of stromal biology, which have been put into four categories: reorganization of the extracellular matrix (ECM) to promote invasion, changes in the expression of stromal cell types, changes in stromal gene expression, and changes in cell biology signaling cascades to and from the stroma. PMID:22568982

  17. Deep stroma investigation by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Tatini, Francesca; Pini, Roberto; Valente, Paola; Ardia, Roberta; Buzzonetti, Luca; Canovetti, Annalisa; Malandrini, Alex; Lenzetti, Ivo; Menabuoni, Luca

    2015-03-01

    Laser assisted keratoplasty is nowadays largely used to perform minimally invasive surgery and partial thickness keratoplasty [1-3]. The use of the femtosecond laser enables to perform a customized surgery, solving the specific problem of the single patient, designing new graft profiles and partial thickness keratoplasty (PTK). The common characteristics of the PTKs and that make them eligible respect to the standard penetrating keratoplasty, are: the preservation of eyeball integrity, a reduced risk of graft rejection, a controlled postoperative astigmatism. On the other hand, the optimal surgical results after these PTKs are related to a correct comprehension of the deep stroma layers morphology, which can help in the identification of the correct cleavage plane during surgeries. In the last years some studies were published, giving new insights about the posterior stroma morphology in adult subjects [4,5]. In this work we present a study performed on two groups of tissues: one group is from 20 adult subjects aged 59 +/- 18 y.o., and the other group is from 15 young subjects, aged 12+/-5 y.o.. The samples were from tissues not suitable for transplant in patients. Confocal microscopy and Environmental Scanning Electron Microscopy (ESEM) were used for the analysis of the deep stroma. The preliminary results of this analysis show the main differences in between young and adult tissues, enabling to improve the knowledge of the morphology and of the biomechanical properties of human cornea, in order to improve the surgical results in partial thickness keratoplasty.

  18. Myxoid Leiomyosarcoma of the Uterus: A Clinicopathologic Analysis of 30 Cases and Review of the Literature With Reappraisal of Its Distinction From Other Uterine Myxoid Mesenchymal Neoplasms.

    PubMed

    Parra-Herran, Carlos; Schoolmeester, John K; Yuan, Liping; Dal Cin, Paola; Fletcher, Christopher D M; Quade, Bradley J; Nucci, Marisa R

    2016-03-01

    Myxoid leiomyosarcoma (mLMS) of the uterus is a rare neoplasm; thus, knowledge of its clinical behavior and morphology remains limited. We therefore reviewed 30 cases initially diagnosed as uterine mLMS to better characterize its clinicopathologic features. Diagnosis was confirmed in 25 subjects (average age 51.5 y), of whom 80% were stage 1 at presentation. The average tumor size was 10.8 cm. An infiltrative tumor border was observed microscopically in 24 cases (96%); the border in 1 case could not be assessed. Fourteen cases (56%) had >10 mitoses per 10 high-power fields, 8 (32%) had between 2 and 10, and 3 cases (12%) had <2 mitoses. Geographic tumor necrosis and moderate to severe nuclear pleomorphism were seen concurrently in 12 cases (48%). All tumors expressed smooth muscle markers. Estrogen receptor was expressed in 29.4% of cases. Eighteen of 21 cases (85.7%) were negative for ALK by immunohistochemistry. Follow-up information was available in 18 subjects: 8 died of disease, 6 were alive with local and/or distant recurrence, and 4 were alive with no evidence of disease. Individuals who died of disease tended to have tumors with >10 mitoses per 10 high-power fields. Among cases with ≥5-year follow-up, overall survival was 11.1%, significantly worse compared with reported survival rates for conventional LMS. The initial diagnosis of mLMS was revised in 5 cases. Four had a distinctive loose myxoid appearance, nuclei with vesicular chromatin, and ALK positivity by immunohistochemistry, suggesting, suggesting inflammatory myofibroblastic tumor. This diagnosis was confirmed by in situ hybridization in 2 cases. One additional myxoid tumor lacked smooth muscle or myofibroblastic features and could not be classified further. mLMS is an aggressive neoplasm characterized by infiltrative tumor borders and variability of other features (mitotic count, atypia, and necrosis). The differential diagnosis includes myxoid leiomyoma and inflammatory myofibroblastic tumor

  19. Primary endobronchial myxoid leiomyoma in a child: An unusual case report and review of literature.

    PubMed

    Awasthi, Ashutosh; Dubey, Suparna; Sabhikhi, Abha K; Bal, Sabyasachi

    2016-01-01

    Primary leiomyomas are rare benign tumors of the lung and only 25 cases have been documented in children, most of which are endobronchial. Leiomyomas are benign smooth muscle neoplasms, usually diagnosed on morphological characteristics. However, immunohistochemistry plays a crucial role in the lineage differentiation when these are encountered at unusual sites or with unexpected morphological features. We report a case of endobronchial tumor of a 13-year-old male child who presented with a dry cough and hemoptysis. A mass lesion in the right main bronchus was detected by bronchoscopy and contrast-enhanced computed tomography. On histopathological examination of the resected specimen, a diagnosis of myxoid leiomyoma was made. To the best of our knowledge, this is the first case of myxoid leiomyoma to be reported in the respiratory tract. This case also demonstrates the need for a high index of suspicion and the role of immunomarkers in the diagnosis of such challenging cases. PMID:26960646

  20. A novel type of EWS-CHOP fusion gene in myxoid liposarcoma

    SciTech Connect

    Matsui, Yoshito . E-mail: ymatsui@sb4.so-net.ne.jp; Ueda, Takafumi; Kubo, Takahiro; Hasegawa, Tadashi; Tomita, Yasuhiko; Okamoto, Mina; Myoui, Akira; Kakunaga, Shigeki; Yasui, Natsuo; Yoshikawa, Hideki

    2006-09-22

    The cytogenetic hallmark of myxoid type and round cell type liposarcoma consists of reciprocal translocation of t(12;16)(q13;p11) and t(12;22)(q13;q12), which results in fusion of TLS/FUS and CHOP, and EWS and CHOP, respectively. Nine structural variations of the TLS/FUS-CHOP chimeric transcript have been reported, however, only two types of EWS-CHOP have been described. We describe here a case of myxoid liposarcoma containing a novel EWS-CHOP chimeric transcript and identified the breakpoint occurring in intron 13 of EWS. Reverse transcription-polymerase chain reaction and direct sequence showed that exon 13 of EWS was in-frame fused to exon 2 of CHOP. Genomic analysis revealed that the breaks were located in intron 13 of EWS and intron 1 of CHOP.

  1. Myxoid Chondrosarcoma of Maxilla in a Pediatric Patient: A Rare Case Report

    PubMed Central

    Nimonkar, Pranali; Bhola, Nitin; Jadhav, Anendd; Jain, Anuj; Borle, Rajiv; Ranka, Rajul; Chaudhary, Minal

    2016-01-01

    Myxoid variant of chondrosarcoma is an uncommon potentially lethal malignant tumor which is even rare in pediatric age group. In the present paper, we report one such case of intermediate grade myxoid chondrosarcoma of left side of maxilla in a 12-year-old girl. The present case had a firm, painless, and lobulated growth in premolar-molar region which was associated with bicortical expansion. Maxillofacial imaging showed ill-defined radiolucency with displaced maxillary molars. Osteolytic changes were evident with the alveolus and walls of maxillary sinus. Owing to the age of the patient, surgical excision was selected as the modality of management followed by postoperative radiotherapy. This report encompasses the entire gamut of clinicopathological, radiological, and treatment modalities employed for chondrosarcoma. PMID:26904332

  2. Discal cyst associated with myxoid change and apoptosis of herniated disc materials: a case report.

    PubMed

    Okada, Kyoji; Saito, Hajime; Nishida, Jun; Miyakoshi, Naohisa; Takahashi, Shu; Nagasawa, Hiroyuki; Suzuki, Norio; Chida, Shuichi

    2007-01-01

    Discal cyst is a lumbar intraspinal cyst communicating with intervertebral disc, and previously reported series described the wall of these cysts as consisting of dense fibrous connective tissue. We report a 29-year-old Japanese male with discal cyst showing unusual histological features. Clinical symptoms in the current case as well as imaging features including discography were similar to those previously reported.However, the wall of the cyst consisted of disc material with myxoid degeneration. In addition, apoptosis of chondrocytes was diffusely observed in the herniated disc material. The current case was considered a histological variant of discal cyst. Myxoid degeneration of herniated disc material with diffuse apoptotic change of chondrocytes was probably associated with the formation of discal cyst. PMID:17578806

  3. Stroma Targeting Nuclear Imaging and Radiopharmaceuticals

    PubMed Central

    Shetty, Dinesh; Jeong, Jae-Min; Shim, Hyunsuk

    2012-01-01

    Malignant transformation of tumor accompanies profound changes in the normal neighboring tissue, called tumor stroma. The tumor stroma provides an environment favoring local tumor growth, invasion, and metastatic spreading. Nuclear imaging (PET/SPECT) measures biochemical and physiologic functions in the human body. In oncology, PET/SPECT is particularly useful for differentiating tumors from postsurgical changes or radiation necrosis, distinguishing benign from malignant lesions, identifying the optimal site for biopsy, staging cancers, and monitoring the response to therapy. Indeed, PET/SPECT is a powerful, proven diagnostic imaging modality that displays information unobtainable through other anatomical imaging, such as CT or MRI. When combined with coregistered CT data, [18F]fluorodeoxyglucose ([18F]FDG)-PET is particularly useful. However, [18F]FDG is not a target-specific PET tracer. This paper will review the tumor microenvironment targeting oncologic imaging such as angiogenesis, invasion, hypoxia, growth, and homing, and also therapeutic radiopharmaceuticals to provide a roadmap for additional applications of tumor imaging and therapy. PMID:22685650

  4. Ectopic micronodular thymoma with lymphoid stroma in the cervical region: a rare case associated with Langerhans cells proliferation

    PubMed Central

    Yu, Min; Meng, Yuan; Xu, Bin; Zhao, Lin; Zhang, Qingfu

    2016-01-01

    Micronodular thymoma (MNT) with lymphoid stroma is a rare thymic epithelial neoplasm with the characteristics of multiple nodules separated by abundant lymphoid stroma. MNTs mainly arise in the anterior mediastinum and thymus, while ectopic MNTs are extremely rarely seen. Here, we report an ectopic MNT that occurred in the neck of a 62-year-old woman. There were also scattered eosinophilic granulocytes and S100+/CD1a+ Langerhans cells within the tumor. This case provides a better understanding of such rare, poorly understood cases. PMID:27486334

  5. Abundant lubricin expression suggests a link between synoviocytes, synovial tumors, and myxomas.

    PubMed

    Solka, Kathryn A; Schmid, Thomas M; Miller, Ira J

    2016-10-01

    Progenitor cell differentiation into fibroblast-like synoviocytes (FLSs) and their ensuing phenotypic changes are incompletely explored. Synovial lining is composed of intimal macrophages and FLSs. FLSs have epithelioid morphology and directionally secrete components of synovial fluid, including lubricin. We stained human tissues and tumors using two anti-lubricin antibodies. Lubricin was found in FLSs in synovium and in tenosynovial giant cell tumors (TSGCTs) and not in the associated monocyte/macrophage cells, which were identified by double immunostaining for CD163. In TSGCTs, giant cells, known to form by fusion of mononuclear cells, were negative for both lubricin and CD163. Occasional mononuclear cells with the same phenotype were also seen, suggesting that the precursors of the giant cells are derived from the minor CD163-negative monocyte subset. Lubricin was also detected in intramuscular myxomas, in early myxoid changes of ganglion cysts, and in one of five low-grade myxofibrosarcomas, but not in other fibroconnective tissues, epithelial tissues, or other tumors tested. This suggests that lubricin expression may typify adaptive and neoplastic changes along a pathway toward FLSs. Further support for this concept comes from ganglion cysts and juxta-articular myxoma tumors, which show a spectrum of myxoid, cystic and synovial differentiation, and in which moderate lubricin staining of myxoid stroma was seen. PMID:26924731

  6. Lysyl hydroxylase 2 induces a collagen cross-link switch in tumor stroma

    PubMed Central

    Chen, Yulong; Terajima, Masahiko; Yang, Yanan; Sun, Li; Ahn, Young-Ho; Pankova, Daniela; Puperi, Daniel S.; Watanabe, Takeshi; Kim, Min P.; Blackmon, Shanda H.; Rodriguez, Jaime; Liu, Hui; Behrens, Carmen; Wistuba, Ignacio I.; Minelli, Rosalba; Scott, Kenneth L.; Sanchez-Adams, Johannah; Guilak, Farshid; Pati, Debananda; Thilaganathan, Nishan; Burns, Alan R.; Creighton, Chad J.; Martinez, Elisabeth D.; Zal, Tomasz; Grande-Allen, K. Jane; Yamauchi, Mitsuo; Kurie, Jonathan M.

    2015-01-01

    Epithelial tumor metastasis is preceded by an accumulation of collagen cross-links that heighten stromal stiffness and stimulate the invasive properties of tumor cells. However, the biochemical nature of collagen cross-links in cancer is still unclear. Here, we postulated that epithelial tumorigenesis is accompanied by changes in the biochemical type of collagen cross-links. Utilizing resected human lung cancer tissues and a p21CIP1/WAF1-deficient, K-rasG12D-expressing murine metastatic lung cancer model, we showed that, relative to normal lung tissues, tumor stroma contains higher levels of hydroxylysine aldehyde–derived collagen cross-links (HLCCs) and lower levels of lysine aldehyde–derived cross-links (LCCs), which are the predominant types of collagen cross-links in skeletal tissues and soft tissues, respectively. Gain- and loss-of-function studies in tumor cells showed that lysyl hydroxylase 2 (LH2), which hydroxylates telopeptidyl lysine residues on collagen, shifted the tumor stroma toward a high-HLCC, low-LCC state, increased tumor stiffness, and enhanced tumor cell invasion and metastasis. Together, our data indicate that LH2 enhances the metastatic properties of tumor cells and functions as a regulatory switch that controls the relative abundance of biochemically distinct types of collagen cross-links in the tumor stroma. PMID:25664850

  7. Myxoid chondrosarcoma of the mandible in a 22-year-old man: A case report

    PubMed Central

    Chen, Ying; Zhang, Ying

    2016-01-01

    This study describes a case of myxoid chondrosarcoma of the mandible in a 22-year-old male patient. A tumour in the buccal gingiva of the lower left premolar region had been identified 2 years earlier. Whole-jaw panoramic radiographs showed a hypodense shadow in the mesiodistal area near the roots of teeth 34 and 35. A maxillofacial computed tomography scan revealed a mass in the lower left premolar soft tissue, with a shadow indicating bone destruction, a clear boundary and uniform density. The preliminary diagnosis at the outpatient department was 34–35 epulis. The patient underwent surgery for 34–35 gingival tumour resection, 34 and 35 extraction, and 34 and 35 immediate implantation. The postoperative pathological examination revealed a cellular type extraskeletal myxoid chondrosarcoma of the lower left mandible. Under general anaesthesia, the patient underwent lower left mandibular block and segmental resection, submandibular triangle dissection and vessel disassociation, and musculocutaneous flap repair in the oral and maxillofacial defect area. After 9 months of follow-up, the patient had no complaints of discomfort, and tumour recurrence was not observed on imaging examinations. PMID:27602220

  8. Excellent Local Control Rates and Distinctive Patterns of Failure in Myxoid Liposarcoma Treated With Conservation Surgery and Radiotherapy

    SciTech Connect

    Guadagnolo, B. Ashleigh Zagars, Gunar K.; Ballo, Matthew T.; Patel, Shreyaskumar R.; Lewis, Valerae O.; Benjamin, Robert S.; Pollock, Raphael E.

    2008-03-01

    Purpose: To evaluate the local control rates and patterns of metastatic relapse in patients with localized myxoid liposarcoma treated with conservation surgery and radiotherapy (RT). Patients and Methods: Between 1960 and 2003, 127 patients with non-metastatic myxoid liposarcoma were treated with conservation surgery and RT at our institution. The median patient age was 39 years (range, 14-79 years). Of the 127 patients, 46% underwent preoperative RT (median dose, 50 Gy) and 54% underwent postoperative RT (median dose, 60 Gy). Also, 28% received doxorubicin-based chemotherapy as a part of their treatment. Results: The median follow-up was 9.1 years. The overall survival rate at 5 and 10 years was 87% and 79%, respectively. The corresponding disease-free survival rates were 81% and 73%. The local control rate at {>=}5 years was 97%. The actuarial rate of distant metastases at 5 and 10 years was 15% and 24%, respectively. Of the 27 patients who developed distant metastases, 48% did so in the retroperitoneum, 22% in other extrapulmonary soft tissues, 22% in the lung, 15% in bone, and 4% in the liver. Conclusion: The results of our study have shown that RT and conservation surgery for localized myxoid liposarcoma provide excellent local control. Distant metastatic relapse tended to occur in the retroperitoneum and other nonpulmonary soft tissues. Therefore, staging and surveillance imaging should include the abdomen and pelvis, as well as the thorax, for patients with localized myxoid liposarcoma.

  9. The autophagic tumor stroma model of cancer

    PubMed Central

    Pavlides, Stephanos; Tsirigos, Aristotelis; Migneco, Gemma; Whitaker-Menezes, Diana; Chiavarina, Barbara; Flomenberg, Neal; Frank, Philippe G; Casimiro, Mathew C; Wang, Chenguang; Pestell, Richard G; Martinez-Outschoorn, Ubaldo E; Howell, Anthony

    2010-01-01

    A loss of stromal caveolin-1 (Cav-1) in the tumor fibroblast compartment is associated with early tumor recurrence, lymphnode metastasis and tamoxifen-resistance, resulting in poor clinical outcome in breast cancer patients. Here, we have used Cav-1 (−/−) null mice as a pre-clinical model for this “lethal tumor micro-environment”. Metabolic profiling of Cav-1 (−/−) mammary fat pads revealed the upregulation of numerous metabolites (nearly 100), indicative of a major catabolic phenotype. Our results are consistent with the induction of oxidative stress, mitochondrial dysfunction and autophagy/mitophagy. The two most prominent metabolites that emerged from this analysis were ADMA (asymmetric dimethyl arginine) and BHB (beta-hydroxybutyrate; a ketone body), which are markers of oxidative stress and mitochondrial dysfunction, respectively. Transcriptional profiling of Cav-1 (−/−) stromal cells and human tumor stroma from breast cancer patients directly supported an association with oxidative stress, mitochondrial dysfunction and autophagy/mitophagy, as well as ADMA and ketone production. MicroRNA profiling of Cav-1 (−/−) stromal cells revealed the upregulation of two key cancer-related miR's, namely miR-31 and miR-34c. Consistent with our metabolic findings, these miR's are associated with oxidative stress (miR-34c) or activation of the hypoxic response/HIF1α (miR-31), which is sufficient to drive authophagy/mitophagy. Thus, via an unbiased comprehensive analysis of a lethal tumor micro-environment, we have identified a number of candidate biomarkers (ADMA, ketones and miR-31/34c) that could be used to identify high-risk cancer patients at diagnosis, for treatment stratification and/or for evaluating therapeutic efficacy during anti-cancer therapy. We propose that the levels of these key biomarkers (ADMA, ketones/BHB, miR-31 and miR-34c) could be (1) assayed using serum or plasma from cancer patients or (2) performed directly on excised tumor

  10. Targeting the tumor stroma in hepatocellular carcinoma

    PubMed Central

    Heindryckx, Femke; Gerwins, Pär

    2015-01-01

    Hepatocellular carcinoma (HCC) is one of the most common and deadly cancers worldwide. In ninety percent of the cases it develops as a result of chronic liver damage and it is thus a typical inflammation-related cancer characterized by the close relation between the tumor microenvironment and tumor cells. The stromal environment consists out of several cell types, including hepatic stellate cells, macrophages and endothelial cells. They are not just active bystanders in the pathogenesis of HCC, but play an important and active role in tumor initiation, progression and metastasis. Furthermore, the tumor itself influences these cells to create a background that is beneficial for sustaining tumor growth. One of the key players is the hepatic stellate cell, which is activated during liver damage and differentiates towards a myofibroblast-like cell. Activated stellate cells are responsible for the deposition of extracellular matrix, increase the production of angiogenic factors and stimulate the recruitment of macrophages. The increase of angiogenic factors (which are secreted by macrophages, tumor cells and activated stellate cells) will induce the formation of new blood vessels, thereby supplying the tumor with more oxygen and nutrients, thus supporting tumor growth and offering a passageway in the circulatory system. In addition, the secretion of chemokines by the tumor cells leads to the recruitment of tumor associated macrophages. These tumor associated macrophages are key actors of cancer-related inflammation, being the main type of inflammatory cells infiltrating the tumor environment and exerting a tumor promoting effect by secreting growth factors, stimulating angiogenesis and influencing the activation of stellate cells. This complex interplay between the several cell types involved in liver cancer emphasizes the need for targeting the tumor stroma in HCC patients. PMID:25729472

  11. Imaging aspects of the tumor stroma with therapeutic implications.

    PubMed

    Narunsky, Lian; Oren, Roni; Bochner, Filip; Neeman, Michal

    2014-02-01

    Cancer cells rely on extensive support from the stroma in order to survive, proliferate and invade. The tumor stroma is thus an important potential target for anti-cancer therapy. Typical changes in the stroma include a shift from the quiescence promoting-antiangiogenic extracellular matrix to a provisional matrix that promotes invasion and angiogenesis. These changes in the extracellular matrix are induced by changes in the secretion of extracellular matrix proteins and glucose amino glycans, extravasation of plasma proteins from hyperpermeable vessels and release of matrix modifying enzymes resulting in cleavage and cross-linking of matrix macromolecules. These in turn alter the rigidity of the matrix and the exposure and release of cytokines. Changes in matrix rigidity and vessel permeability affect drug delivery and mediate resistance to cytotoxic therapy. These stroma changes are brought about not only by the cancer cells, but also through the action of many cell types that are recruited by tumors including immune cells, fibroblasts and endothelial cells. Within the tumor, these normal host cells are activated resulting in loss of inhibitory and induction of cancer promoting activities. Key to the development of stroma-targeted therapies, selective biomarkers were developed for specific imaging of key aspects of the tumor stroma. PMID:24134903

  12. Imaging aspects of the tumor stroma with therapeutic implications

    PubMed Central

    Narunsky, Lian; Oren, Roni; Bochner, Filip; Neeman, Michal

    2013-01-01

    Cancer cells rely on extensive support from the stroma in order to survive, proliferate and invade. The tumor stroma is thus an important potential target for anti-cancer therapy. Typical changes in the stroma include a shift from the quiescence promoting- antiangiogenic extracellular matrix to a provisional matrix that promotes invasion and angiogenesis. These changes in the extracellular matrix are induced by changes in the secretion of extracellular matrix proteins and glucose amino glycans, extravasation of plasma proteins from hyperpermeable vessels and release of matrix modifying enzymes resulting in cleavage and crosslinking of matrix macromolecules. These in turn alter the rigidity of the matrix and the exposure and release of cytokines. Changes in matrix rigidity and vessel permeability affect drug delivery and mediate resistance to cytotoxic therapy. These stroma changes are brought about not only by the cancer cells, but also through the action of many cell types that are recruited by tumors including immune cells, fibroblasts and endothelial cells. Within the tumor, these normal host cells are activated resulting in loss of inhibitory and induction of cancer promoting activities. Key to the development of stroma targeted therapies, selective biomarkers were developed for specific imaging of key aspects of the tumor stroma. PMID:24134903

  13. Membrane-to-Nucleus Signals and Epigenetic Mechanisms for Myofibroblastic Activation and Desmoplastic Stroma: Potential Therapeutic Targets for Liver Metastasis?

    PubMed Central

    Kang, Ningling; Shah, Vijay H.; Urrutia, Raul

    2015-01-01

    Cancer associated fibroblasts (CAFs), the most abundant cells in the tumor microenvironment (TME), are a key source of extracellular matrix (ECM) that constitutes the desmoplastic stroma. Through remodeling of the reactive tumor stroma and paracrine actions, CAFs regulate cancer initiation, progression, and metastasis, as well as tumor resistance to therapies. The CAFs found in stroma-rich primary hepatocellular carcinomas (HCCs) and liver metastases of primary cancers of other organs predominantly originate from hepatic stellate cells (HSTCs), which are pericytes associated with hepatic sinusoids. During tumor invasion, HSTCs transdifferentiate into myofibroblasts in response to paracrine signals emanating from either tumor cells or a heterogenous cell population within the hepatic tumor microenvironment. Mechanistically, HSTC-to-myofibroblast transdifferentiation, also known as, HSTC activation, requires cell surface receptor activation, intracellular signal transduction, gene transcription and epigenetic signals, which combined ultimately modulate distinct gene expression profiles that give rise to and maintain a new phenotype. The current review, defines a paradigm that explains how HSTCs are activated into CAFs to promote liver metastasis. Furthermore, focus on the most relevant intracellular signaling networks and epigenetic mechanisms that control HSTC activation is provided. Finally, we discuss the feasibility of targeting CAF/activated HSTCs, in isolation or in conjunction with targeting cancer cells, which constitutes a promising and viable therapeutic approach for the treatment of primary stroma-rich liver cancers and liver metastasis. PMID:25548101

  14. Diagnosis of Prostate Cancer Using Differentially Expressed Genes in Stroma

    PubMed Central

    Jia, Zhenyu; Wang, Yipeng; Sawyers, Anne; Yao, Huazhen; Rahmatpanah, Farahnaz; Xia, Xiao-Qin; Xu, Qiang; Pio, Rebecca; Turan, Tolga; Koziol, James A.; Goodison, Steve; Carpenter, Philip; Wang-Rodriquez, Jessica; Simoneau, Anne; Meyskens, Frank; Sutton, Manuel; Lernhardt, Waldemar; Beach, Thomas; Monforte, Joseph; McClelland, Michael; Mercola, Dan

    2011-01-01

    Over one million prostate biopsies are performed in the U.S. every year. A failure to find cancer is not definitive in a significant percentage of patients due to the presence of equivocal structures or continuing clinical suspicion. We have identified gene expression changes in stroma that can detect tumor nearby. We compared gene expression profiles of 13 biopsies containing stroma near tumor and 15 biopsies from volunteers without prostate cancer. About 3800 significant expression changes were found and thereafter filtered using independent expression profiles to eliminate possible age-related genes and genes expressed at detectable levels in tumor cells. A stroma-specific classifier for nearby tumor was constructed based on 114 candidate genes and tested on 364 independent samples, including 243 tumor-bearing samples and 121 non-tumor samples (normal biopsies, normal autopsies, remote stroma, as well as stroma within a few millimeters of tumor). The classifier predicted the tumor status of patients using tumor-free samples with an average accuracy of 97% (sensitivity = 98% and specificity = 88%) whereas classifiers trained with sets of 100 randomly generated genes had no diagnostic value. These results indicate that the prostate cancer microenvironment exhibits reproducible changes useful for categorizing the presence of tumor in patients when a prostate sample is derived from near the tumor but does not contain any recognizable tumor. PMID:21459804

  15. Myxoid angioblastomatosis of bones. A case report of a rare, multifocal entity with light, ultramicroscopic, and immunopathologic correlation.

    PubMed

    Mirra, J M; Kameda, N

    1985-06-01

    An example of multicentric, skeletal, myxoid angioblastomas in a Japanese woman is reported. The disease was symptomatic at age 12 years and was characterized by slowly progressive, multiple, lytic bone defects. In addition the patient had juvenile hypertension, and, at age 20 years, had focal brain infarction. The primitive vascular nature of the process was supported by the following observations: occasional erythrocytes within cytoplasmic lumina and capillary-like cellular tubes; Weibel-Palade bodies, numerous pinocytotic vesicles, prominent microvilli, elaborate intercellular contacts, desmosomes, and numerous arrays of fine intracytoplasmic filaments by electron microscopy; and, in addition, Factor VIII positivity. The clinical findings in this case are more consistent with a multicentric, rather than a metastatic process. The name myxoid angioblastomatosis of bones is appropriate. PMID:4091181

  16. FGFR2 is overexpressed in myxoid liposarcoma and inhibition of FGFR signaling impairs tumor growth in vitro

    PubMed Central

    Künstlinger, Helen; Fassunke, Jana; Schildhaus, Hans-Ulrich; Brors, Benedikt; Heydt, Carina; Ihle, Michaela Angelika; Mechtersheimer, Gunhild; Wardelmann, Eva; Büttner, Reinhard; Merkelbach-Bruse, Sabine

    2015-01-01

    Myxoid liposarcomas account for more than one third of liposarcomas and about 10% of all adult soft tissue sarcomas. The tumors are characterized by specific chromosomal translocations leading to the chimeric oncogenes FUS-DDIT3 or EWS1R-DDIT3. The encoded fusion proteins act as aberrant transcription factors. Therefore, we implemented comparative expression analyses using whole-genome microarrays in tumor and fat tissue samples. We aimed at identifying differentially expressed genes which may serve as diagnostic or prognostic biomarkers or as therapeutic targets. Microarray analyses revealed overexpression of FGFR2 and other members of the FGF/FGFR family. Overexpression of FGFR2 was validated by qPCR, immunohistochemistry and western blot analysis in primary tumor samples. Treatment of the myxoid liposarcoma cell lines MLS 402 and MLS 1765 with the FGFR inhibitors PD173074, TKI258 (dovitinib) and BGJ398 as well as specific siRNAs reduced cell proliferation, induced apoptosis and delayed cell migration. Combination of FGFR inhibitors with trabectedin further increased the effect. Our study demonstrates overexpression of FGFR2 and a functional role of FGFR signaling in myxoid liposarcoma. As FGFR inhibition showed effects on proliferation and cell migration and induced apoptosis in vitro, our data indicate the potential use of FGFR inhibitors as a targeted therapy for these tumors. PMID:26036639

  17. FGFR2 is overexpressed in myxoid liposarcoma and inhibition of FGFR signaling impairs tumor growth in vitro.

    PubMed

    Künstlinger, Helen; Fassunke, Jana; Schildhaus, Hans-Ulrich; Brors, Benedikt; Heydt, Carina; Ihle, Michaela Angelika; Mechtersheimer, Gunhild; Wardelmann, Eva; Büttner, Reinhard; Merkelbach-Bruse, Sabine

    2015-08-21

    Myxoid liposarcomas account for more than one third of liposarcomas and about 10% of all adult soft tissue sarcomas. The tumors are characterized by specific chromosomal translocations leading to the chimeric oncogenes FUS-DDIT3 or EWS1R-DDIT3. The encoded fusion proteins act as aberrant transcription factors. Therefore, we implemented comparative expression analyses using whole-genome microarrays in tumor and fat tissue samples. We aimed at identifying differentially expressed genes which may serve as diagnostic or prognostic biomarkers or as therapeutic targets. Microarray analyses revealed overexpression of FGFR2 and other members of the FGF/FGFR family. Overexpression of FGFR2 was validated by qPCR, immunohistochemistry and western blot analysis in primary tumor samples. Treatment of the myxoid liposarcoma cell lines MLS 402 and MLS 1765 with the FGFR inhibitors PD173074, TKI258 (dovitinib) and BGJ398 as well as specific siRNAs reduced cell proliferation, induced apoptosis and delayed cell migration. Combination of FGFR inhibitors with trabectedin further increased the effect. Our study demonstrates overexpression of FGFR2 and a functional role of FGFR signaling in myxoid liposarcoma. As FGFR inhibition showed effects on proliferation and cell migration and induced apoptosis in vitro, our data indicate the potential use of FGFR inhibitors as a targeted therapy for these tumors. PMID:26036639

  18. Tumor stroma as targets for cancer therapy

    PubMed Central

    Zhang, Jing; Liu, Jinsong

    2012-01-01

    Cancer is not only composed malignant epithelial component but also stromal components such as fibroblasts, endothelial cells, and inflammatory cells, by which an appropriate tumor microenvironment (TME) is formed to promote tumorigenesis, progression, and metastasis. As the most abundant component in the TME, cancer-associated fibroblasts (CAFs) are involved in multifaceted mechanistic details including remodeling the extracellular matrix, suppressing immune responses, and secreting growth factors and cytokines that mediate signaling pathways to extensively affect tumor cell growth and invasiveness, differentiation, angiogenesis, and chronic inflammatory milieu. Today, more and more therapeutic strategies are purposefully designed to target the TME as well as tumor cells. This review will focus on the role of CAFs in tumor development and the novel strategies to target this component to inhibit the tumor growth. PMID:23064233

  19. Tumor Stroma, Tumor Blood Vessels, and Antiangiogenesis Therapy.

    PubMed

    Dvorak, Harold F

    2015-01-01

    Solid tumors generally require a vascularized connective tissue stroma if they are to grow beyond minimal size. They generate that stroma in part by secreting vascular endothelial growth factor (VEGF), a potent vascular permeability and angiogenic factor. Increased vascular permeability leads to deposition of a provisional fibrin stroma, which supports tumor, connective tissue, and inflammatory cell migration and plays an active role in the formation of mature vascularized stroma. Vascular endothelial growth factor-induced tumor blood vessels are heterogeneous, of at least 6 distinct types, and develop linearly over time. They include both angiogenic (mother vessels, glomeruloid microvascular proliferations, vascular malformations, capillaries) and arteriovenogenic (feeding arteries, draining veins) blood vessels. Attacking the tumor vasculature with drugs that target VEGF or its receptors (VEGFR) has come into vogue but has been less effective than had been hope for. One reason for this is that anti-VEGF/VEGFR therapy attacks only a subset of tumor blood vessels, the earliest to form. New targets on late-forming blood vessels such as feeding arteries would be useful in helping antivascular cancer therapy fulfill its promise. PMID:26222073

  20. Establishment and characterization of a new human myxoid liposarcoma cell line (DL-221) with the FUS-DDIT3 translocation.

    PubMed

    de Graaff, Marieke A; Yu, Jamie S E; Beird, Hannah C; Ingram, Davis R; Nguyen, Theresa; Juehui Liu, Jeffrey; Bolshakov, Svetlana; Szuhai, Károly; Åman, Pierre; Torres, Keila E; Lev, Dina; Nielsen, Torsten O; Bovée, Judith V M G; Lazar, Alexander J; Somaiah, Neeta

    2016-08-01

    Myxoid liposarcoma has the pathognomonic fusion oncogene FUS-DDIT3 encoding a chimeric transcription factor. Metastatic risk is higher with an increased round cell component and has been linked to aberrations involving the IGFR/PI3K/AKT pathway. These molecular insights have yet to translate to targeted therapies, and the lack of experimental models is a major hindrance. We describe the initial in-depth characterization of a new cell line (DL-221) and establishment of a mouse xenograft model. The cell line DL-221 was derived from a metastatic pleural lesion showing myxoid and round cell histology. This newly established cell line was characterized for phenotypic properties and molecular cytogenetic profile, using PCR, COBRA-FISH, and western blot. Next-generation whole-exome sequencing was performed to further characterize the cell line and the parent tumor. NOD-SCID-IL2R gamma knockout mice were xenograft hosts. DL-221 cells grew an adhering monolayer and COBRA-FISH showed an aneuploid karyotype with t(12;16)(q13;p11) and several other rearrangements; RT-PCR demonstrated a FUS-DDIT3 fusion transcript type 1. Both the cell line and the original tumor harbored a TP53 compound heterozygous mutation in exon 4 and 7, and were wild-type for PIK3CA. Moreover, among the 1254 variants called by whole-exome sequencing, there was 77% concordance between the cell line and parent tumor. The recently described hotspot mutation in the TERT promoter region in myxoid liposarcomas was also found at C228T in DL-221. Xenografts suitable for additional preclinical studies were successfully established in mice after subcutaneous injection. The established DL-221 cell line is the only published available myxoid liposarcoma cell line that underwent spontaneous immortalization, without requiring SV40 transformation. The cell line and its xenograft model are unique and helpful tools to study the biology and novel potential-targeted treatment approaches for myxoid liposarcoma. PMID:27270875

  1. Mucinous Urothelial Carcinoma of the Renal Pelvis

    PubMed Central

    Behzatğlu, Kemal; Boyaci, Ceren; Okçu, Oğuzhan; Hacihasanoğlu, Ezgi; Çakir, Yasemin; Darakçi, Seher

    2014-01-01

    Urothelial carcinoma with abundant myxoid stroma is a newly-described and extremely rare entity. Since only very few cases have been reported, there is no consensus on its nomenclature. Microscopic examination revealed invasive urothelial carcinoma with widespread low-grade noninvasive areas. There were focal invasive areas in the neighborhood of the renal parenchyma. Malignant urothelial tumor/cell groups localized in the stroma had abundant myxoid/mucinous background in the invasive areas. The cytoplasm of the tumoral cells was more eosinophilic in these areas and the cells formed small groups and cords. Histochemically, PAS and Alcian Blue were positive in the cytoplasm of the tumoral cells and in the stroma while negative in the non-mucinous areas. Immunohistochemically, the tumoral cells of the mucinous invasive areas diffusely expressed MUC1 and MUC2. We discuss the origin of the mucinous/myxoid stroma, the tumor’s nature and its nomenclature with histochemical and immunohistochemical features. PMID:25568745

  2. Normal and Functional TP53 in Genetically Stable Myxoid/Round Cell Liposarcoma

    PubMed Central

    Ståhlberg, Anders; Kåbjörn Gustafsson, Christina; Engtröm, Katarina; Thomsen, Christer; Dolatabadi, Soheila; Jonasson, Emma; Li, Chieh-Yuan; Ruff, David; Chen, Shiaw-Min; Åman, Pierre

    2014-01-01

    Myxoid/round-cell liposarcoma (MLS/RCLS) is characterized by either the fusion gene FUS-DDIT3 or the less commonly occurring EWSR1-DDIT3 and most cases carry few or no additional cytogenetic changes. There are conflicting reports concerning the status and role of TP53 in MLS/RCLS. Here we analysed four MLS/RCLS derived cell lines for TP53 mutations, expression and function. Three SV40 transformed cell lines expressed normal TP53 proteins. Irradiation caused normal posttranslational modifications of TP53 and induced P21 expression in two of these cell lines. Transfection experiments showed that the FUS-DDIT3 fusion protein had no effects on irradiation induced TP53 responses. Ion Torrent AmpliSeq screening, using the Cancer Hotspot panel, showed no dysfunctional or disease associated alleles/mutations. In conclusion, our results suggest that most MLS/RCLS cases carry functional TP53 genes and this is consistent with the low numbers of secondary mutations observed in this tumor entity. PMID:25393000

  3. Cancer-stroma evolutionary dynamics in stress-gradient microenvironment

    NASA Astrophysics Data System (ADS)

    Wu, Amy; Lambert, Guillaume; Austin, Robert; Sturm, James; Khin, Zayar; Silva, Ariosto

    2012-02-01

    In order to study the evolution of drug resistance in cancer, it is important to mimic the tumor microenvironment, in which cells are exposed to not uniform concentrations but rather gradients of drugs, nutrients, and other factors Compared to traditional in-vitro methods, microfluidic structure enables better control of the temporal and spatial profile of gradients. Here we demonstrate a microfluidic Doxorubicin gradient environment with heterogeneous landscape, and culture multiple myeloma (8226-S, expressing RFP) and bone marrow stroma (HS-5, expressing GFP) cell lines together. The myeloma cells are not directly motile, but they are able to migrate via the adhesion to motile stroma cells. The indirect motility mechanism of the myeloma cells is crucial for the adaptation to stress environment. Finally, we will report the co-culture dynamics under the stress of doxorubicin gradients, observing for cellular migrations and growth

  4. Ex vivo and in vivo modulatory effects of umbilical cord Wharton's jelly stem cells on human oral mucosa stroma substitutes.

    PubMed

    Alfonso-Rodríguez, C A; González-Andrades, E; Jaimes-Parra, B D; Fernández-Valadés, R; Campos, A; Sánchez-Quevedo, M C; Alaminos, M; Garzón, I

    2015-11-01

    Novel oral mucosa substitutes have been developed in the laboratory using human umbilical cord Wharton's jelly stem cells -HWJSC- as an alternative cell source. In the present work, we have generated human oral mucosa substitutes with oral mucosa keratinocytes and HWJSC to determine the influence of these cell sources on stromal differentiation. First, acellular and cellular stroma substitutes and bilayered oral mucosa substitutes with an epithelial layer consisting of oral mucosa keratinocytes -OM samples- or HWJSC -hOM- were generated. Then, tissues were analyzed by light and electron microscopy, histochemistry and immunohistochemistry to quantify all major extracellular matrix components after 1, 2 and 3 weeks of ex vivo development, and OM and hOM were also analyzed after in vivo grafting. The results showed that bioengineered oral mucosa stromas displayed an adequate fibrillar mesh. Synthesis of abundant collagen fibers was detected in OM and hOM after 3 weeks, and in vivo grafting resulted in an increased collagen synthesis. No elastic or reticular fibers were found. Glycoprotein synthesis was found at the epithelial-stromal layer when samples were grafted in vivo. Finally, proteoglycans, decorin, versican and aggrecan were strongly dependent on the in vivo environment and the presence of a well-structured epithelium on top. The use of HWJSC was associated to an increased synthesis of versican. These results confirm the usefulness of fibrin-agarose biomaterials for the generation of an efficient human oral mucosa stroma substitute and the importance of the in vivo environment and the epithelial-mesenchymal interaction for the adequate differentiation of the bioengineered stroma. PMID:25967581

  5. Riboflavin concentration in corneal stroma after intracameral injection

    PubMed Central

    Li, Na; Peng, Xiu-Jun; Fan, Zheng-Jun; Pang, Xu; Xia, Yu; Wu, Teng-Fei

    2015-01-01

    AIM To evaluate the enrichment of riboflavin in the corneal stroma after intracameral injection to research the barrier ability of the corneal endothelium to riboflavin in vivo. METHODS The right eyes of 30 New Zealand white rabbits were divided into three groups. Different concentrations riboflavin-balanced salt solutions (BSS) were injected into the anterior chamber (10 with 0.5%, 10 with 1%, and 10 with 2%). Eight corneal buttons of 8.5 mm in diameter from each group were dissected at 30min after injection and the riboflavin concentrations in the corneal stroma were determined using high-performance liquid chromatography (HPLC) after removing the epithelium and endothelium. The other two rabbits in every group were observed for 24h and sacrificed. As a comparison, the riboflavin concentrations from 16 corneal stromal samples were determined using HPLC after instillation of 0.1% riboflavin-BSS solution for 30min on the corneal surface (8 without epithelium and 8 with intact epithelium). RESULTS The mean riboflavin concentrations were 11.19, 18.97, 25.08, 20.18, and 1.13 µg/g for 0.5%, 1%, 2%, de-epithelialzed samples, and the transepithelial groups, respectively. The color change of the corneal stroma and the HPLC results showed that enrichment with riboflavin similar to classical de-epithelialized corneal collagen crosslinking (CXL) could be achieved by intracameral 1% riboflavin-BSS solution after 30min; the effect appeared to be continuous for at least 30min. CONCLUSION Riboflavin can effectively penetrate the corneal stroma through the endothelium after an intracameral injection in vivo, so it could be an enhancing method that could improve the corneal riboflavin concentration in transepithelial CXL. PMID:26085993

  6. Tumour stroma-derived lipocalin-2 promotes breast cancer metastasis.

    PubMed

    Ören, Bilge; Urosevic, Jelena; Mertens, Christina; Mora, Javier; Guiu, Marc; Gomis, Roger R; Weigert, Andreas; Schmid, Tobias; Grein, Stephan; Brüne, Bernhard; Jung, Michaela

    2016-07-01

    Tumour cell-secreted factors skew infiltrating immune cells towards a tumour-supporting phenotype, expressing pro-tumourigenic mediators. However, the influence of lipocalin-2 (Lcn2) on the metastatic cascade in the tumour micro-environment is still not clearly defined. Here, we explored the role of stroma-derived, especially macrophage-released, Lcn2 in breast cancer progression. Knockdown studies and neutralizing antibody approaches showed that Lcn2 contributes to the early events of metastasis in vitro. The release of Lcn2 from macrophages induced an epithelial-mesenchymal transition programme in MCF-7 breast cancer cells and enhanced local migration as well as invasion into the extracellular matrix, using a three-dimensioanl (3D) spheroid model. Moreover, a global Lcn2 deficiency attenuated breast cancer metastasis in both the MMTV-PyMT breast cancer model and a xenograft model inoculating MCF-7 cells pretreated with supernatants from wild-type and Lcn2-knockdown macrophages. To dissect the role of stroma-derived Lcn2, we employed an orthotopic mammary tumour mouse model. Implantation of wild-type PyMT tumour cells into Lcn2-deficient mice left primary mammary tumour formation unaltered, but specifically reduced tumour cell dissemination into the lung. We conclude that stroma-secreted Lcn2 promotes metastasis in vitro and in vivo, thereby contributing to tumour progression. Our study highlights the tumourigenic potential of stroma-released Lcn2 and suggests Lcn2 as a putative therapeutic target. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:27038000

  7. Effectiveness of Radiotherapy in Myxoid Sarcomas Is Associated With a Dense Vascular Pattern

    SciTech Connect

    Vreeze, Ronald S.A. de Jong, Daphne de; Haas, Rick L.; Stewart, Fiona; Coevorden, Frits van

    2008-12-01

    Purpose: Surgery and adjuvant radiotherapy (RT) have long been the standard treatment for most deep-seated sarcomas; however, since the randomized trial from the National Cancer Institute of Canada, which described similar local control for pre- vs. postoperative RT, both modalities are now widely accepted. As a group, sarcomas are classified as radiation resistant. The subgroup of myxoid liposarcoma (MLS), a sarcoma with a typical vascular crow's feet pattern, is highly radiosensitive, but a mechanism for this phenomenon is unknown. Here we describe our results with preoperative RT and propose a mechanism explaining the high sensitivity based on the distinctive vascularization pattern of MLS. Methods and Materials: Between 2002 and 2006, 31 sarcoma patients, including 10 with MLS, underwent preoperative RT at our institute. Resected specimens were histologically evaluated, focusing on classification, grade, and vascularization patterns. Results: Twenty sarcomas showed more than 80% pathologic response after preoperative RT. A pathologic complete response was found in all 'pure' MLS specimens after preoperative RT (n = 8). There were no pathologic complete responses in the remaining sarcoma patients (n = 23), although 12 showed 80% to 90% pathologic response. In contrast to the remaining RT-resistant sarcomas, the highly responding specimens contained branching vasculature, partial thrombus formation and inflammation of medium sized arterioles, similar to the vascular changes in MLS. Conclusions: Both MLS and sarcomas with MLS-like vasculature are highly radiosensitive. Radiation sensitivity may be explained by changes in medium-sized arterioles, obstructing the specific crow's feet vascularization and inducing hypoxia with secondary tumor cell death.

  8. Myxoid malignant fibrous histiocytoma and pleomorphic liposarcoma share very similar genomic imbalances.

    PubMed

    Idbaih, Ahmed; Coindre, Jean-Michel; Derré, Josette; Mariani, Odette; Terrier, Philippe; Ranchère, Dominique; Mairal, Aline; Aurias, Alain

    2005-02-01

    Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma. Nevertheless, the validity of this heterogeneous pathological entity has been recurrently questioned by pathologists. Recently, analyses by comparative genomic hybridization (CGH) of a large series of MFHs suggested that MFHs consist of morphologic modulation of other poorly differentiated sarcomas like leiomyosarcomas (LMS) or dedifferentiated liposarcomas (DLPS). We report here an analysis by CGH of 22 myxoid MFHs (mMFH), one of the five histological subtypes of MFH, and of nine pleomorphic liposarcomas (pLPS), a rare poorly differentiated LPS. The chromosome imbalances encountered in the series of mMFH were very similar to those observed in the series of pLPS studied in the laboratory and in the series of 14 pLPS published in the literature. The most frequent gains involved chromosome subregions: pericentromeric regions of 1, 5p, 19p, 19q and 20q. Losses found in the chromosomal arms 1q, 2q, 3p, 4q, 10q, 11q and 13q were also recurrent. The use of a clustering software did not separate the two pathological groups (mMFH and pLPS) on the basis of genomic data. Moreover, pLPS-mMFH represented, according to the clustering software results, an entity clearly distinguished from other soft tissue sarcomas, LMS in particular, with which they share common genetic aberrations. Additional studies are needed to identify genes targeted by these genomic aberrations, and implicated in the oncogenesis of these tumor subtypes. The characterization of common gene alterations in both tumor groups would suggest a closer relationship between these two types of soft tissue sarcomas. PMID:15702084

  9. Pancreatic cancer and its stroma: A conspiracy theory

    PubMed Central

    Xu, Zhihong; Pothula, Srinivasa P; Wilson, Jeremy S; Apte, Minoti V

    2014-01-01

    Pancreatic cancer is characterised by a prominent desmoplastic/stromal reaction that has received little attention until recent times. Given that treatments focusing on pancreatic cancer cells alone have failed to significantly improve patient outcome over many decades, research efforts have now moved to understanding the pathophysiology of the stromal reaction and its role in cancer progression. In this regard, our Group was the first to identify the cells (pancreatic stellate cells, PSCs) that produced the collagenous stroma of pancreatic cancer and to demonstrate that these cells interacted closely with cancer cells to facilitate local tumour growth and distant metastasis. Evidence is accumulating to indicate that stromal PSCs may also mediate angiogenesis, immune evasion and the well known resistance of pancreatic cancer to chemotherapy and radiotherapy. This review will summarise current knowledge regarding the critical role of pancreatic stellate cells and the stroma in pancreatic cancer biology and the therapeutic approaches being developed to target the stroma in a bid to improve the outcome of this devastating disease. PMID:25170206

  10. Pancreatic cancer and its stroma: a conspiracy theory.

    PubMed

    Xu, Zhihong; Pothula, Srinivasa P; Wilson, Jeremy S; Apte, Minoti V

    2014-08-28

    Pancreatic cancer is characterised by a prominent desmoplastic/stromal reaction that has received little attention until recent times. Given that treatments focusing on pancreatic cancer cells alone have failed to significantly improve patient outcome over many decades, research efforts have now moved to understanding the pathophysiology of the stromal reaction and its role in cancer progression. In this regard, our Group was the first to identify the cells (pancreatic stellate cells, PSCs) that produced the collagenous stroma of pancreatic cancer and to demonstrate that these cells interacted closely with cancer cells to facilitate local tumour growth and distant metastasis. Evidence is accumulating to indicate that stromal PSCs may also mediate angiogenesis, immune evasion and the well known resistance of pancreatic cancer to chemotherapy and radiotherapy. This review will summarise current knowledge regarding the critical role of pancreatic stellate cells and the stroma in pancreatic cancer biology and the therapeutic approaches being developed to target the stroma in a bid to improve the outcome of this devastating disease. PMID:25170206

  11. Cytogenetic analysis of myxoid liposarcoma and myxofibrosarcoma by array‐based comparative genomic hybridisation

    PubMed Central

    Ohguri, T; Hisaoka, M; Kawauchi, S; Sasaki, K; Aoki, T; Kanemitsu, S; Matsuyama, A; Korogi, Y; Hashimoto, H

    2006-01-01

    Aim To investigate overall chromosomal alterations using array‐based comparative genomic hybridisation (CGH) of myxoid liposarcomas (MLSs) and myxofibrosarcomas (MFSs). Materials and methods Genomic DNA extracted from fresh‐frozen tumour tissues was labelled with fluorochromes and then hybridised on to an array consisting of 1440 bacterial artificial chromosome clones representing regions throughout the entire human genome important in cytogenetics and oncology. Results DNA copy number aberrations (CNAs) were found in all the 8 MFSs, but no alterations were found in 7 (70%) of 10 MLSs. In MFSs, the most frequent CNAs were gains at 7p21.1–p22.1 and 12q15–q21.1 and a loss at 13q14.3–q34. The second most frequent CNAs were gains at 7q33–q35, 9q22.31–q22.33, 12p13.32–pter, 17q22–q23, Xp11.2 and Xq12 and losses at 10p13–p14, 10q25, 11p11–p14, 11q23.3–q25, 20p11–p12 and 21q22.13–q22.2, which were detected in 38% of the MFSs examined. In MLSs, only a few CNAs were found in two sarcomas with gains at 8p21.2–p23.3, 8q11.22–q12.2 and 8q23.1–q24.3, and in one with gains at 5p13.2–p14.3 and 5q11.2–5q35.2 and a loss at 21q22.2–qter. Conclusions MFS has more frequent and diverse CNAs than MLS, which reinforces the hypothesis that MFS is genetically different from MLS. Out‐array CGH analysis may also provide several entry points for the identification of candidate genes associated with oncogenesis and progression in MFS. PMID:16751306

  12. Stroma Cells in Tumor Microenvironment and Breast Cancer

    PubMed Central

    Mao, Yan; Keller, Evan T.; Garfield, David H.; Shen, Kunwei; Wang, Jianhua

    2015-01-01

    Cancer is a systemic disease, encompassing multiple components of both tumor cells themselves and host stromal cells. It is now clear that stromal cells in the tumor microenvironment play an important role in cancer development. Molecular events through which reactive stromal cells affect cancer cells can be defined so that biomarkers and therapeutic targets can be identified. Cancer-associated fibroblasts (CAFs) make up the bulk of cancer stroma and affect the tumor microenvironment such that they promote cancer initiation, angiogenesis, invasion and metastasis. In breast cancer, CAFs not only promote tumor progression, but also induce therapeutic resistances. Accordingly, targeting CAFs provides a novel way to control tumors with therapeutic resistances. This review summarizes the current understanding of tumor stroma in breast cancer with a particular emphasis on the role of CAFs and the therapeutic implications of CAFs. The effects of other stromal components such as endothelial cells, macrophages and adipocytes in breast cancer are also discussed. Finally, we describe the biologic markers to sort patients into a specific and confirmed subtype for personalized treatment. PMID:23114846

  13. Evaluation of Tumor-associated Stroma and Its Relationship with Tumor Hypoxia Using Dynamic Contrast-enhanced CT and (18)F Misonidazole PET in Murine Tumor Models.

    PubMed

    Koyasu, Sho; Tsuji, Yoshihisa; Harada, Hiroshi; Nakamoto, Yuji; Nobashi, Tomomi; Kimura, Hiroyuki; Sano, Kohei; Koizumi, Koji; Hamaji, Masatsugu; Togashi, Kaori

    2016-03-01

    Purpose To determine the relationship between the fractional interstitial volume (Fis), as calculated at dynamic contrast material-enhanced (DCE) computed tomography (CT), and tumor-associated stroma and to analyze its spatial relationship with tumor hypoxia in several xenograft tumor models. Materials and Methods All animal experiments were approved by the animal research committee. Mice with three different xenograft tumors (U251, CFPAC-1, and BxPC-3; n = 6, n = 8, and n = 6, respectively) underwent DCE CT then hypoxia imaging with fluorine 18 ((18)F) fluoromisonidazole (FMISO) positron emission tomography (PET) within 24 hours. Immunohistochemical analysis was performed in harvested tumors to detect hypoxia markers and to quantify microvascular and stromal density. Two DCE CT parameters (amount of interstitial space associated with the amount of stroma [Fis] and flow velocity [Fv]) were identified and quantitatively validated by using immunohistochemistry. FMISO uptake within the tumor was also assessed in relation to DCE CT parameters. Imaging and immunohistochemical parameters were assessed by using the Kruskal-Wallis test, Wilcoxon rank-sum test with Bonferroni correction, and Pearson correlation coefficient. Results Almost no α-smooth muscle actin-positive cells were found in the U251 xenograft, while abundant stroma was found in the entire BxPC-3 xenograft and in the periphery of the CFPAC-1 xenograft. Quantitative analysis showed a significant correlation (R = 0.83, P < .0001) between Fis and stromal density. FMISO uptake had a negative correlation with Fis (R = -0.58, P < .0001) and Fv (R = -0.53, P < .0001). Conclusion DCE CT can be used to quantify parameters associated with tumor-associated stroma. Tumor hypoxia was Complementarily localized in tumor-associated stroma in these models. (©) RSNA, 2015 Online supplemental material is available for this article. PMID:26393963

  14. TERT promoter hotspot mutations are recurrent in myxoid liposarcomas but rare in other soft tissue sarcoma entities

    PubMed Central

    2014-01-01

    Background Recently, recurrent point mutations in the telomerase reverse transcriptase (TERT) promoter region have been found in many human cancers, leading to a new transcription factor binding site, increased induction of TERT and subsequently to telomere maintenance. We determined the prevalence of TERT promoter mutations in soft tissue sarcomas of 341 patients comprising 16 entities and in 16 sarcoma cell lines covering 7 different soft tissue sarcoma types. Methods The sarcoma tissue samples were collected from the archives of the Institute of Pathology, University of Heidelberg and were composed of 39 myxoid liposarcomas (MLS), 61 dedifferentiated liposarcomas, 15 pleomorphic liposarcomas, 27 leiomyosarcomas, 25 synovial sarcomas (SS), 35 malignant peripheral nerve sheath tumors (MPNST), 40 undifferentiated pleomorphic sarcomas, 17 myxofibrosarcomas, 9 low grade fibromyxoid sarcomas, 10 cases of dermatofibrosarcoma protuberans, 31 solitary fibrous tumors (SFT), 8 extraskeletal myxoid chondrosarcomas, 9 angiosarcomas, 6 alveolar soft part sarcomas, 5 clear cell sarcomas and 4 epithelioid sarcomas. Sarcoma cell lines were obtained from the raising laboratories. A 193 bp fragment of the TERT promoter region covering the hot-spot mutations C228T and C250T was amplified, and direct sequencing of the PCR products was performed. Results TERT promoter mutations were detected in 36/341 sarcomas. They were highly recurrent in MLS (29/39; 74%) and were in the present MLS series not associated with the phenotype (myxoid vs. round cell variant), tumor grade, tumor site and patients’ median age or gender. In the remaining cases, TERT promoter mutations were found only in 7/302 sarcoma samples and confined to SFTs (4/31; 13%), MPNSTs (2/35; 6%), and SSs (1/25; 4%). Within the collection of sarcoma cell lines examined, TERT promoter mutations were detected in two MLS and in one of three MPNST cell lines. Conclusions TERT promoter mutations are frequent in MLSs including

  15. High-grade primary myxoid lung sarcoma presenting as recurrent hemorrhagic pleural effusions in a young woman

    PubMed Central

    Tahir, Hassan; Coleman, Cinthia; Sagi, Jahnavi; Wani, Adil; Daruwalla, Vistasp

    2015-01-01

    Primary lung sarcomas are rare but aggressive tumors accounting for less than 0.5% of all lung tumors. The diagnosis of primary lung sarcoma should only be considered after exclusion of other sites. A 32-year-old female presented with recurrent hemorrhagic pleural effusions, shortness of breath and persistent cough. Pleural effusion was drained twice, and each time its analysis was normal. Patient developed atelectasis of left lung with hemothorax for which she underwent video-assisted thoracoscopic surgery. A large mass was found compressing the entire lower lobe of left lung with extension into mediastinum, the biopsy of which showed myxoid sarcoma. The tumor was inoperable and options of chemotherapy or radiotherapy were discussed with the patient. Primary lung sarcoma can rarely present with recurrent hemorrhagic pleural effusion. A high degree of suspicion is required for early diagnosis as large hemothorax on computed tomography or chest X-ray may obscure lung mass and make its diagnosis difficult. PMID:27489706

  16. Studies on the molecular pathogenesis of extraskeletal myxoid chondrosarcoma-cytogenetic, molecular genetic, and cDNA microarray analyses.

    PubMed

    Sjögren, Helene; Meis-Kindblom, Jeanne M; Orndal, Charlotte; Bergh, Peter; Ptaszynski, Konrad; Aman, Pierre; Kindblom, Lars-Gunnar; Stenman, Göran

    2003-03-01

    Extraskeletal myxoid chondrosarcomas (EMCs) are characterized by recurrent chromosome translocations resulting in fusions of the nuclear receptor TEC to various NH(2)-terminal partners. Here we describe the phenotypic, cytogenetic, and molecular genetic characteristics of a series of 10 EMCs. Using spectral karyotyping and fluorescence in situ hybridization, clonal chromosome abnormalities were detected in all but one tumor. A t(9;22)(q22;q12) translocation was found in three cases; a del(22)(q12-13)in one case; and variant translocations, including t(9;17)(q22;q11-12), t(7;9;17)(q32;q22;q11), and t(9;15)(q22;q21), were detected in one case each. Recurrent, secondary abnormalities, including trisomy 1q, 7, 8, 12, and 19, were found in seven tumors. All tumors contained translocation-generated or cryptic gene fusions, including EWS-TEC (five cases, of which one was a novel fusion), TAF2N-TEC (four cases), and TCF12-TEC (one case). cDNA microarray analysis of the gene expression patterns of two EMCs and a myxoid liposarcoma reference tumor revealed a remarkably distinct and uniform expression profile in both EMCs despite the fact that they had different histologies and expressed different fusion transcripts. The most differentially expressed gene in both tumors was CHI3L1, which encodes a secreted glycoprotein (YKL-40) previously implicated in various pathological conditions of extracellular matrix degradation as well as in cancer. Our findings suggests that EMC exhibits a tumor-specific gene expression profile, including overexpression of several cancer-related genes as well as genes implicated in chondrogenesis and neural-neuroendocrine differentiation, thus distinguishing it from other soft tissue sarcomas. PMID:12598313

  17. Prognostic Significance of the Tumor-Stroma Ratio in Epithelial Ovarian Cancer

    PubMed Central

    Chen, Ying; Zhang, Lei; Liu, Wenxin; Liu, Xiangyu

    2015-01-01

    Tumor-stroma ratio (TSR) has recently been identified as a promising prognostic parameter for several solid tumors. This study aimed to evaluate the prognostic role of TSR in epithelial ovarian cancer (EOC) and 838 EOC patients were enrolled in this study. TSR was estimated on hematoxylin-and-eosin-stained tissue sections from the most invasive part of the primary tumor. Patients were classified as stroma-rich or stroma-poor according to the proportion of stroma ≥50% or <50%. Chi-square test analysis revealed that TSR were significantly associated with FIGO stage, LN status, and recurrence or not (all of them P < 0.001). The higher stroma-rich proportions were found in EOC patients with advanced stage (36.13% versus 19.75%), LN metastasis (51.93% versus 27.25%), and recurrence (34.27% versus 6.82%). Stroma-rich EOC patients had obvious shorter median time of progression-free survival (29 versus 39 months) and overall survival (50 versus 58 months), respectively. TSR was an independent prognostic factor for the evaluation of PFS in EOC. Stroma-rich tumors had worse prognosis and higher risk of relapse compared with those in stroma-poor tumors in EOC patients. Considered easy to determine for routine pathological examination, TSR may serve as a new prognostic histological parameter in EOC. PMID:26609529

  18. IL-33 activates tumor stroma to promote intestinal polyposis.

    PubMed

    Maywald, Rebecca L; Doerner, Stephanie K; Pastorelli, Luca; De Salvo, Carlo; Benton, Susan M; Dawson, Emily P; Lanza, Denise G; Berger, Nathan A; Markowitz, Sanford D; Lenz, Heinz-Josef; Nadeau, Joseph H; Pizarro, Theresa T; Heaney, Jason D

    2015-05-12

    Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by nonepithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin 33 (IL-33) as a regulator of tumor stromal cell activation and mediator of intestinal polyposis. In human colorectal cancer, IL-33 expression was induced in the tumor epithelium of adenomas and carcinomas, and expression of the IL-33 receptor, IL1RL1 (also referred to as IL1-R4 or ST2), localized predominantly to the stroma of adenoma and both the stroma and epithelium of carcinoma. Genetic and antibody abrogation of responsiveness to IL-33 in the Apc(Min/+) mouse model of intestinal tumorigenesis inhibited proliferation, induced apoptosis, and suppressed angiogenesis in adenomatous polyps, which reduced both tumor number and size. Similar to human adenomas, IL-33 expression localized to tumor epithelial cells and expression of IL1RL1 associated with two stromal cell types, subepithelial myofibroblasts and mast cells, in Apc(Min/+) polyps. In vitro, IL-33 stimulation of human subepithelial myofibroblasts induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in Apc(Min/+) polyps and suppressed the expression of mast cell-derived proteases and cytokines known to promote polyposis. Based on these findings, we propose that IL-33 derived from the tumor epithelium promotes polyposis through the coordinated activation of stromal cells and the formation of a protumorigenic microenvironment. PMID:25918379

  19. IL-33 activates tumor stroma to promote intestinal polyposis

    PubMed Central

    Maywald, Rebecca L.; Doerner, Stephanie K.; Pastorelli, Luca; De Salvo, Carlo; Benton, Susan M.; Dawson, Emily P.; Lanza, Denise G.; Berger, Nathan A.; Markowitz, Sanford D.; Lenz, Heinz-Josef; Nadeau, Joseph H.; Pizarro, Theresa T.; Heaney, Jason D.

    2015-01-01

    Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by nonepithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin 33 (IL-33) as a regulator of tumor stromal cell activation and mediator of intestinal polyposis. In human colorectal cancer, IL-33 expression was induced in the tumor epithelium of adenomas and carcinomas, and expression of the IL-33 receptor, IL1RL1 (also referred to as IL1-R4 or ST2), localized predominantly to the stroma of adenoma and both the stroma and epithelium of carcinoma. Genetic and antibody abrogation of responsiveness to IL-33 in the ApcMin/+ mouse model of intestinal tumorigenesis inhibited proliferation, induced apoptosis, and suppressed angiogenesis in adenomatous polyps, which reduced both tumor number and size. Similar to human adenomas, IL-33 expression localized to tumor epithelial cells and expression of IL1RL1 associated with two stromal cell types, subepithelial myofibroblasts and mast cells, in ApcMin/+ polyps. In vitro, IL-33 stimulation of human subepithelial myofibroblasts induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in ApcMin/+ polyps and suppressed the expression of mast cell-derived proteases and cytokines known to promote polyposis. Based on these findings, we propose that IL-33 derived from the tumor epithelium promotes polyposis through the coordinated activation of stromal cells and the formation of a protumorigenic microenvironment. PMID:25918379

  20. The bone marrow stroma in hematological neoplasms—a guilty bystander

    PubMed Central

    Tripodo, Claudio; Sangaletti, Sabina; Piccaluga, Pier P.; Prakash, Sonam; Franco, Giovanni; Borrello, Ivan; Orazi, Attilio; Colombo, Mario P.; Pileri, Stefano A.

    2013-01-01

    In the setting of hematological neoplasms, changes in the bone marrow (BM) stroma might arise from pressure exerted by the neoplastic clone in shaping a supportive microenvironment, or from chronic perturbation of the BM homeostasis. Under such conditions, alterations in the composition of the BM stroma can be profound, and could emerge as relevant prognostic factors. In this Review, we delineate the multifaceted contribution of the BM stroma to the pathobiology of several hematological neoplasms, and discuss the impact of stromal modifications on the natural course of these diseases. Specifically, we highlight the involvement of BM stromal components in lymphoid and myeloid malignancies, and present the most relevant processes responsible for remodeling the BM stroma. The role of bystander BM stromal elements in the setting of hematological neoplasms is discussed, strengthening the rationale for treatment strategies that target the BM stroma. PMID:21448151

  1. Mapping the Extracellular and Membrane Proteome Associated with the Vasculature and the Stroma in the Embryo*

    PubMed Central

    Soulet, Fabienne; Kilarski, Witold W.; Roux-Dalvai, Florence; Herbert, John M. J.; Sacewicz, Izabela; Mouton-Barbosa, Emmanuelle; Bicknell, Roy; Lalor, Patricia; Monsarrat, Bernard; Bikfalvi, Andreas

    2013-01-01

    In order to map the extracellular or membrane proteome associated with the vasculature and the stroma in an embryonic organism in vivo, we developed a biotinylation technique for chicken embryo and combined it with mass spectrometry and bioinformatic analysis. We also applied this procedure to implanted tumors growing on the chorioallantoic membrane or after the induction of granulation tissue. Membrane and extracellular matrix proteins were the most abundant components identified. Relative quantitative analysis revealed differential protein expression patterns in several tissues. Through a bioinformatic approach, we determined endothelial cell protein expression signatures, which allowed us to identify several proteins not yet reported to be associated with endothelial cells or the vasculature. This is the first study reported so far that applies in vivo biotinylation, in combination with robust label-free quantitative proteomics approaches and bioinformatic analysis, to an embryonic organism. It also provides the first description of the vascular and matrix proteome of the embryo that might constitute the starting point for further developments. PMID:23674615

  2. CCX-CKR deficiency alters thymic stroma impairing thymocyte development and promoting autoimmunity.

    PubMed

    Bunting, Mark D; Comerford, Iain; Seach, Natalie; Hammett, Maree V; Asquith, Darren L; Körner, Heinrich; Boyd, Richard L; Nibbs, Robert J B; McColl, Shaun R

    2013-01-01

    The atypical chemokine receptor CCX-CKR regulates bioavailability of CCL19, CCL21, and CCL25, homeostatic chemokines that play crucial roles in thymic lymphopoiesis. Deletion of CCX-CKR results in accelerated experimental autoimmunity induced by immunization. Here we show that CCX-CKR deletion also increases incidence of a spontaneous Sjögren's syndrome-like pathology, characterized by lymphocytic infiltrates in salivary glands and liver of CCX-CKR(-/-) mice, suggestive of a defect in self-tolerance when CCX-CKR is deleted. This prompted detailed examination of the thymus in CCX-CKR(-/-) mice. Negatively selected mature SP cells were less abundant in CCX-CKR(-/-) thymi, yet expansion of both DP and immature SP cells was apparent. Deletion of CCX-CKR also profoundly reduced proportions of DN3 thymocyte precursors and caused DN2 cells to accumulate within the medulla. These effects are likely driven by alterations in thymic stroma as CCX-CKR(-/-) mice have fewer cTECs per thymocyte, and cTECs express the highest level of CCX-CKR in the thymus. A profound decrease in CCL25 within the thymic cortex was observed in CCX-CKR(-/-) thymi, likely accounting for their defects in thymocyte distribution and frequency. These findings identify a novel role for CCX-CKR in regulating cTEC biology, which promotes optimal thymocyte development and selection important for self-tolerant adaptive immunity. PMID:23152546

  3. Baculovirus phosphoprotein pp31 is associated with virogenic stroma.

    PubMed Central

    Guarino, L A; Dong, W; Xu, B; Broussard, D R; Davis, R W; Jarvis, D L

    1992-01-01

    The PstI K fragment of Autographa californica nuclear polyhedrosis virus (AcMNPV) encodes a protein with a molecular weight of 31,000. To define the role of this protein (pp31) in virus infection further, it was overexpressed in bacteria and used to produce polyclonal antiserum. Radioimmunoprecipitation analysis indicated that pp31 was synthesized during both the early and late phases of virus infection, consistent with previous analyses indicating that the gene was regulated by tandem early and late promoters. Metabolic labeling of cells with carrier-free phosphate indicated that pp31 was phosphorylated. Biochemical fractionation experiments showed that pp31 was localized in the nucleus and that it was more stably associated with the nucleus at later times of infection. Immunoblot analysis of subnuclear fractions indicated that pp31 was associated predominantly with the chromatin and nuclear matrix fractions. Immunofluorescence experiments confirmed that the pp31 protein was localized in the nucleus. Nuclear staining was relatively uniform early but was more centrally nuclear later in infection. Immunoelectron microscopy indicated that the pp31 protein was a component of virogenic stroma. Southwestern (DNA-protein) blot analysis demonstrated that pp31 is a DNA-binding protein. These findings suggest a possible role for pp31 in the virus life cycle. Images PMID:1433508

  4. [Treatment Strategy for Gastric Carcinoma with Lymphoid Stroma].

    PubMed

    Kobayashi, Ryosuke; Takiguchi, Nobuhiro; Nabeya, Yoshihiro; Ikeda, Atsushi; Souda, Hiroaki; Kainuma, Osamu; Tonooka, Toru; Imanishi, Shunsuke; Arimitsu, Hidehito; Chibana, Tomofumi; Ishige, Fumitaka; Sasaki, Kosuke; Yamamoto, Hiroshi

    2015-11-01

    Gastric carcinoma with lymphoid stroma (GCLS) is a histological type with severe lymphocytic infiltration. GCLS is very rare and few cases have been reported. We examined the clinical features, problems of preoperative diagnosis, and treatment of 14 cases (1.8%) that were diagnosed as GCLS out of 790 gastric cancers surgically resected in our hospital. The mean age was 69 years. Six, 8, and 0 cases were located in the upper, middle, and lower fields of the stomach, respectively, and 8, 1, 4, and 1 cases were macroscopically 0-Ⅱc, 0-Ⅰ, type 2, and type 3, respectively. The depth of invasion was M, SM1, SM2, MP, and SS in 0, 0, 9, 3, and 2 cases, respectively. There were 12 cases(86%)with infection by Epstein-Barr virus, and just 1 case with lymph node metastasis. All cases have had no evidence of recurrence. There were no cases that were diagnosed as GCLS before surgery. GCLS is recognized as having a more favorable prognosis compared with other types of gastric carcinoma, so an aggressive surgery might achieve good outcomes. However, preoperative diagnosis is very difficult and there is a compelling need for new techniques or criteria for diagnosis of GCLS. PMID:26805251

  5. The emerging role of Snail1 in the tumor stroma.

    PubMed

    Herrera, A; Herrera, M; Peña, C

    2016-09-01

    The transcription factor Snail1 leads to the epithelial-mesenchymal transition by repressing the adherent and tight junctions in epithelial cells. This process is related to an increase of cell migratory and mesenchymal properties during both embryonic development and tumor progression. Although Snail1 expression is very limited in adult animals, emerging evidence has placed Snail at the forefront of medical science. As a transcriptional repressor, Snail1 confers cancer stem cell-like traits on tumor cells and promotes drug resistance, tumor recurrence and metastasis. In this review, we summarize recent reports that suggest the pro-tumorigenic roles of Snail1 expression in tumor stroma. The crosstalk between tumor and stromal cells mediated by Snail1 regulates paracrine communication, pro-tumorigenic abilities of cancer cells, extracellular matrix characteristics and mesenchymal differentiation in cancer stem cells and cancer-associated fibroblasts. Therefore, understanding the regulation and functional roles of Snail1 in the tumor microenvironment will provide us with new therapies for treating metastatic disease. PMID:26687368

  6. GIANT-CELL RICH ATRIAL MYXOMA: REPORT OF TWO CASES AND REVIEW OF LITERATURE.

    PubMed

    Tariq, Hina; Mamoon, Nadira

    2016-01-01

    The cases of two middle age males are presented who were incidentally diagnosed to have atrial myxoma. Both of them underwent successful surgical interventions. Histologically, both myxomas showed abundant multinucleated giant cells, in addition to typical myxoid stroma with stellate and cord-like structures. PMID:27323595

  7. Expression of proteoglycan core proteins in human bone marrow stroma.

    PubMed Central

    Schofield, K P; Gallagher, J T; David, G

    1999-01-01

    Heparan sulphate proteoglycans (HSPGs) present on the surface of bone marrow stromal cells and in the extracellular matrix (ECM) have important roles in the control of adhesion and growth of haemopoietic stem and progenitor cells. The two main groups of proteoglycans which contain heparan sulphate chains are members of the syndecan and glypican families. In this study we have identified the main surface membrane and matrix-associated HSPGs present in normal human bone marrow stroma formed in long-term culture. Proteoglycans were extracted from the adherent stromal layers and treated with heparitinase and chondroitinase ABC. The core proteins were detected by Western blotting using antibodies directed against syndecans-1-4, glypican-1 and the ECM HSPG, perlecan. Stromal cell expression at the RNA level was detected by Northern blotting and by reverse transcription PCR. Glypican-1, syndecan-3 and syndecan-4 were the major cell-membrane HSPG species and perlecan was the major ECM proteoglycan. There was no evidence for expression of syndecan-1 protein. Syndecan-3 was expressed mainly as a variant or processed 50-55 kDa core protein and in lower amounts as the characteristic 125 kDa core protein. These results suggest that syndecan-3, syndecan-4 and glypican-1 present on the surface of marrow stromal cells, together with perlecan in the ECM, may be responsible for creating the correct stromal 'niche' for the maintenance and development of haemopoietic stem and progenitor cells. The detection of a variant form of syndecan-3 as a major stromal HSPG suggests a specific role for this syndecan in haemopoiesis. PMID:10527946

  8. Key players in pancreatic cancer-stroma interaction: Cancer-associated fibroblasts, endothelial and inflammatory cells

    PubMed Central

    Nielsen, Michael Friberg Bruun; Mortensen, Michael Bau; Detlefsen, Sönke

    2016-01-01

    Pancreatic cancer (PC) is the most aggressive type of common cancers, and in 2014, nearly 40000 patients died from the disease in the United States. Pancreatic ductal adenocarcinoma, which accounts for the majority of PC cases, is characterized by an intense stromal desmoplastic reaction surrounding the cancer cells. Cancer-associated fibroblasts (CAFs) are the main effector cells in the desmoplastic reaction, and pancreatic stellate cells are the most important source of CAFs. However, other important components of the PC stroma are inflammatory cells and endothelial cells. The aim of this review is to describe the complex interplay between PC cells and the cellular and non-cellular components of the tumour stroma. Published data have indicated that the desmoplastic stroma protects PC cells against chemotherapy and radiation therapy and that it might promote the proliferation and migration of PC cells. However, in animal studies, experimental depletion of the desmoplastic stroma and CAFs has led to more aggressive cancers. Hence, the precise role of the tumour stroma in PC remains to be elucidated. However, it is likely that a context-dependent therapeutic modification, rather than pure depletion, of the PC stroma holds potential for the development of new treatment strategies for PC patients. PMID:26973408

  9. Anterior and posterior corneal stroma elasticity after corneal collagen crosslinking treatment

    PubMed Central

    Dias, Janice; Diakonis, Vasilios F.; Kankariya, Vardhaman P.; Yoo, Sonia H.; Ziebarth, Noël M.

    2013-01-01

    The purpose of this project was to assess anterior and posterior corneal stromal elasticity after corneal collagen cross linking (CXL) treatment in human cadaver eyes using Atomic Force Microscopy (AFM) through indentation. Twenty four human cadaver eyes (12 pairs) were included in this study and divided into 2 groups (6 pairs per group). In both groups, the left eye (OS) served as a control (no riboflavin or CXL treatment was performed) and the right eye (OD) underwent CXL treatment (30 minutes of riboflavin pretreatment followed by 30 minutes of exposure to 3mW/cm2 of ultraviolet light). In group 1, the anterior stroma was exposed by manual delamination of approximately 50μm of the corneal stroma including Bowman’s membrane. In group 2, the posterior stroma was exposed by delamination of the anterior 50% of the corneal stroma including Bowman’s membrane. Delamination was performed after crosslinking treatment in the case of the treated eyes. In all eyes, the stromal elasticity was quantified using AFM through indentation. Young’s modulus of elasticity for the anterior cornea (group 1) was 245.9±209.1kPa (range: 82.3 - 530.8 kPa) for the untreated control eyes, and 467.8±373.2kPa (range: 157.4 – 1126 kPa) for the CXL treated eyes. Young’s modulus for the posterior cornea (group 2) was 100.2±61.9kPa (range: 28.1 - 162.6 kPa) for the untreated control eyes and 66.0±31.8kPa (range: 31.3 - 101.7 kPa) for the CXL treated eyes. Young’s modulus of the anterior stroma significantly increased after CXL treatment (p=0.024), whereas the posterior stroma did not demonstrate a significant difference in Young’s modulus after CXL treatment (p=0.170). The anterior stroma was stiffer than the posterior stroma for both the control and CXL treatment groups (p=0.077 and p=0.023, respectively). Our findings demonstrate that stiffness of the anterior corneal stroma after CXL treatment seems to increase significantly, while the posterior stroma does not seem to be

  10. Multiscale Investigation of the Depth-Dependent Mechanical Anisotropy of the Human Corneal Stroma

    PubMed Central

    Labate, Cristina; Lombardo, Marco; De Santo, Maria P.; Dias, Janice; Ziebarth, Noel M.; Lombardo, Giuseppe

    2015-01-01

    Purpose. To investigate the depth-dependent mechanical anisotropy of the human corneal stroma at the tissue (stroma) and molecular (collagen) level by using atomic force microscopy (AFM). Methods. Eleven human donor corneas were dissected at different stromal depths by using a microkeratome. Mechanical measurements were performed in 15% dextran on the surface of the exposed stroma of each sample by using a custom-built AFM in force spectroscopy mode using both microspherical (38-μm diameter) and nanoconical (10-nm radius of curvature) indenters at 2-μm/s and 15-μm/s indentation rates. Young's modulus was determined by fitting force curve data using the Hertz and Hertz-Sneddon models for a spherical and a conical indenter, respectively. The depth-dependent anisotropy of stromal elasticity was correlated with images of the corneal stroma acquired by two-photon microscopy. Results. The force curves were obtained at stromal depths ranging from 59 to 218 μm. At the tissue level, Young's modulus (ES) showed a steep decrease at approximately 140-μm stromal depth (from 0.8 MPa to 0.3 MPa; P = 0.03) and then was stable in the posterior stroma. At the molecular level, Young's modulus (EC) was significantly greater than at the tissue level; EC decreased nonlinearly with increasing stromal depth from 3.9 to 2.6 MPa (P = 0.04). The variation of microstructure through the thickness correlated highly with a nonconstant profile of the mechanical properties in the stroma. Conclusions. The corneal stroma exhibits unique anisotropic elastic behavior at the tissue and molecular levels. This knowledge may benefit modeling of corneal behavior and help in the development of biomimetic materials. PMID:26098472

  11. Clinicopathologic and radiologic features of extraskeletal myxoid chondrosarcoma: a retrospective study of 40 Chinese cases with literature review.

    PubMed

    Shao, Rui; Lao, I Weng; Wang, Lei; Yu, Lin; Wang, Jian; Fan, Qinhe

    2016-08-01

    The aim of this study is to describe the clinicopathologic and radiologic features of 40 cases of extraskeletal myxoid chondrosarcoma (EMC) from China. There were 25 males and 15 females (sex ratio, 1.7:1). Apart from an adolescent, all patients were adults with a median age of 49years. Twenty-four tumors (60%) occurred in the lower limb and limb girdles, especially the thigh, followed by the upper limb and limb girdles (20%) and trunk (10%). Other less commonly involved locations included the head and neck, sacrococcygeal region, and perineum. Tumors ranged in size from 1.5 to 19cm (mean, 7cm). By radiology, they appeared as hypoattenuated or isoattenuated masses on computed tomography with hyperintense signal on T2-weighted magnetic resonance imaging. Intralesional hypointense septa were present in most cases. Of the 40 tumors, 30 belonged to the classic subtype, whereas 9 cases were cellular, and 1 case had a rhabdoid phenotype. Tumor cells showed variable expression of synaptophysin (36%), S-100 protein (29%), epithelial membrane antigen (11%), and neuron-specific enolase (7%). Ki-67 index was remarkably higher in the cellular variant (mean, 30%). EWSR1-related rearrangement was detected in 12 of 14 cases tested by fluorescence in situ hybridization using break-apart probes. The overall 5- and 7-year survival was 71% and 60%, respectively. Awareness of the imaging features may help pathologists in the diagnosis of EMC. Fluorescence in situ hybridization also serves as a useful diagnostic tool for EMC, especially in the distinction from its mimics. PMID:27402218

  12. Tumor cell-specific bioluminescence platform to identify stroma-induced changes to anticancer drug activity.

    PubMed

    McMillin, Douglas W; Delmore, Jake; Weisberg, Ellen; Negri, Joseph M; Geer, D Corey; Klippel, Steffen; Mitsiades, Nicholas; Schlossman, Robert L; Munshi, Nikhil C; Kung, Andrew L; Griffin, James D; Richardson, Paul G; Anderson, Kenneth C; Mitsiades, Constantine S

    2010-04-01

    Conventional anticancer drug screening is typically performed in the absence of accessory cells of the tumor microenvironment, which can profoundly alter antitumor drug activity. To address this limitation, we developed the tumor cell-specific in vitro bioluminescence imaging (CS-BLI) assay. Tumor cells (for example, myeloma, leukemia and solid tumors) stably expressing luciferase are cultured with nonmalignant accessory cells (for example, stromal cells) for selective quantification of tumor cell viability, in presence versus absence of stromal cells or drug treatment. CS-BLI is high-throughput scalable and identifies stroma-induced chemoresistance in diverse malignancies, including imatinib resistance in leukemic cells. A stroma-induced signature in tumor cells correlates with adverse clinical prognosis and includes signatures for activated Akt, Ras, NF-kappaB, HIF-1alpha, myc, hTERT and IRF4; for biological aggressiveness; and for self-renewal. Unlike conventional screening, CS-BLI can also identify agents with increased activity against tumor cells interacting with stroma. One such compound, reversine, shows more potent activity in an orthotopic model of diffuse myeloma bone lesions than in conventional subcutaneous xenografts. Use of CS-BLI, therefore, enables refined screening of candidate anticancer agents to enrich preclinical pipelines with potential therapeutics that overcome stroma-mediated drug resistance and can act in a synthetic lethal manner in the context of tumor-stroma interactions. PMID:20228816

  13. Thylakoid direct photobioelectrocatalysis: utilizing stroma thylakoids to improve bio-solar cell performance.

    PubMed

    Rasmussen, Michelle; Minteer, Shelley D

    2014-08-28

    Thylakoid membranes from spinach were separated into grana and stroma thylakoid fractions which were characterized by several methods (pigment content, protein gel electrophoresis, photosystem activities, and electron microscopy analysis) to confirm that the intact thylakoids were differentiated into the two domains. The results of photoelectrochemical experiments showed that stroma thylakoid electrodes generate photocurrents more than four times larger than grana thylakoids (51 ± 4 nA cm(-2) compared to 11 ± 1 nA cm(-2)). A similar trend was seen in a bio-solar cell configuration with stroma thylakoids giving almost twice the current (19 ± 3 μA cm(-2)) as grana thylakoids (11 ± 2 μA cm(-2)) with no change in open circuit voltage. PMID:25019197

  14. Integrated Bioinformatics Approach Reveals Crosstalk Between Tumor Stroma and Peripheral Blood Mononuclear Cells in Breast Cancer.

    PubMed

    He, Lang; Wang, Dan; Wei, Na; Guo, Zheng

    2016-01-01

    Breast cancer is now the leading cause of cancer death in women worldwide. Cancer progression is driven not only by cancer cell intrinsic alterations and interactions with tumor microenvironment, but also by systemic effects. Integration of multiple profiling data may provide insights into the underlying molecular mechanisms of complex systemic processes. We performed a bioinformatic analysis of two public available microarray datasets for breast tumor stroma and peripheral blood mononuclear cells, featuring integrated transcriptomics data, protein-protein interactions (PPIs) and protein subcellular localization, to identify genes and biological pathways that contribute to dialogue between tumor stroma and the peripheral circulation. Genes of the integrin family as well as CXCR4 proved to be hub nodes of the crosstalk network and may play an important role in response to stroma-derived chemoattractants. This study pointed to potential for development of therapeutic strategies that target systemic signals travelling through the circulation and interdict tumor cell recruitment. PMID:27039717

  15. A Rare Case of Renal Cell Carcinoma With Leiomyomatous Stroma and Concomitant Ruptured Adrenal Aneurysm.

    PubMed

    Lu, Chuanyong; Nicastri, Anthony; Shao, Charles

    2016-09-01

    Here we report a rare case of coexisting renal cell carcinoma (RCC) with leiomyomatous stroma and a ruptured adrenal aneurysm. The patient was a 75-year-old woman with acute abdominal pain. Imaging studies showed a left peri-renal hematoma and a mass in the left kidney. Left nephrectomy and adrenalectomy were performed. Pathological examination showed a ruptured aneurysm in the left adrenal gland. The renal mass was composed of tubules and acini of epithelial cells and a prominent leiomyomatous stroma. The tumor cells were positive for carbonic anhydrase IX, cytokeratin 7, and negative for AMACR, consistent with clear cell (tubulo) papillary RCC. PMID:27516974

  16. Corneal Opacity in Lumican-Null Mice: Defects in Collagen Fibril Structure and Packing in the Posterior Stroma

    PubMed Central

    Chakravarti, Shukti; Petroll, W. Matthew; Hassell, John R.; Jester, James V.; Lass, Jonathan H.; Paul, Jennifer; Birk, David E.

    2015-01-01

    Purpose Gene targeted lumican-null mutants (lumtm1sc/lumtm1sc) have cloudy corneas with abnormally thick collagen fibrils. The purpose of the present study was to analyze the loss of transparency quantitatively and to define the associated corneal collagen fibril and stromal defects. Methods Backscattering of light, a function of corneal haze and opacification, was determined regionally using in vivo confocal microscopy in lumican-deficient and wild-type control mice. Fibril organization and structure were analyzed using transmission electron microscopy. Biochemical approaches were used to quantify glycosaminoglycan contents. Lumican distribution in the cornea was elucidated immunohistochemically. Results Compared with control stromas, lumican-deficient stromas displayed a threefold increase in backscattered light with maximal increase confined to the posterior stroma. Confocal microscopy through-focusing (CMTF) measurement profiles also indicated a 40% reduction in stromal thickness in the lumican-null mice. Transmission electron microscopy indicated significant collagen fibril abnormalities in the posterior stroma, with the anterior stroma remaining relatively unremarkable. The lumican-deficient posterior stroma displayed a pronounced increase in fibril diameter, large fibril aggregates, altered fibril packing, and poor lamellar organization. Immunostaining of wild-type corneas demonstrated high concentrations of lumican in the posterior stroma. Biochemical assessment of keratan sulfate (KS) content of whole eyes revealed a 25% reduction in KS content in the lumican-deficient mice. Conclusions The structural defects and maximum backscattering of light clearly localized to the posterior stroma of lumican-deficient mice. In normal mice, an enrichment of lumican was observed in the posterior stroma compared with that in the anterior stroma. Taken together, these observations indicate a key role for lumican in the posterior stroma in maintaining normal fibril

  17. Tic40 is important for reinsertion of proteins from the chloroplast stroma into the inner membrane

    PubMed Central

    Chiu, Chi-Chou; Li, Hsou-min

    2008-01-01

    Chloroplast inner-membrane proteins Tic40 and Tic110 are first imported from the cytosol into the chloroplast stroma, and subsequently reinserted from the stroma into the inner membrane. However, the mechanism of reinsertion remains unclear. Here we show that Tic40 itself is involved in this reinsertion process. When precursors of either Tic40 or a Tic110 C-terminal truncate, tpTic110-Tic110N, were imported into chloroplasts isolated from a tic40-null mutant, soluble Tic40 and Tic110N intermediates accumulated in the stroma of tic40-mutant chloroplasts, due to a slower rate of reinsertion. We further show that a larger quantity of soluble Tic21 intermediates also accumulated in the stroma of tic40-mutant chloroplasts. In contrast, inner-membrane insertion of the triose-phosphate/phosphate translocator was not affected by the tic40 mutation. Our data suggest that multiple pathways exist for the insertion of chloroplast inner-membrane proteins. PMID:18657235

  18. Pathophysiological role of microRNA-29 in pancreatic cancer stroma

    PubMed Central

    Kwon, Jason J.; Nabinger, Sarah C.; Vega, Zachary; Sahu, Smiti Snigdha; Alluri, Ravi K.; Abdul-Sater, Zahi; Yu, Zhangsheng; Gore, Jesse; Nalepa, Grzegorz; Saxena, Romil; Korc, Murray; Kota, Janaiah

    2015-01-01

    Dense fibrotic stroma associated with pancreatic ductal adenocarcinoma (PDAC) is a major obstacle for drug delivery to the tumor bed and plays a crucial role in pancreatic cancer progression. Current, anti-stromal therapies have failed to improve tumor response to chemotherapy and patient survival. Furthermore, recent studies show that stroma impedes tumor progression, and its complete ablation accelerates PDAC progression. In an effort to understand the molecular mechanisms associated with tumor-stromal interactions, using in vitro and in vivo models and PDAC patient biopsies, we show that the loss of miR-29 is a common phenomenon of activated pancreatic stellate cells (PSCs)/fibroblasts, the major stromal cells responsible for fibrotic stromal reaction. Loss of miR-29 is correlated with a significant increase in extracellular matrix (ECM) deposition, a major component in PDAC stroma. Our in vitro miR-29 gain/loss-of-function studies document the role of miR-29 in PSC-mediated ECM stromal protein accumulation. Overexpression of miR-29 in activated stellate cells reduced stromal deposition, cancer cell viability, and cancer growth in co-culture. Furthermore, the loss of miR-29 in TGF-β1 activated PSCs is SMAD3 dependent. These results provide insights into the mechanistic role of miR-29 in PDAC stroma and its potential use as a therapeutic agent to target PDAC. PMID:26095125

  19. Understanding tumor-stroma interplays for targeted therapies by armed mesenchymal stromal progenitors: the Mesenkillers

    PubMed Central

    Grisendi, Giulia; Bussolari, Rita; Veronesi, Elena; Piccinno, Serena; Burns, Jorge S; De Santis, Giorgio; Loschi, Pietro; Pignatti, Marco; Di Benedetto, Fabrizio; Ballarin, Roberto; Di Gregorio, Carmela; Guarneri, Valentina; Piccinini, Lino; Horwitz, Edwin M; Paolucci, Paolo; Conte, PierFranco; Dominici, Massimo

    2011-01-01

    A tumor represents a complex structure containing malignant cells strictly coupled with a large variety of surrounding cells constituting the tumor stroma (TS). In recent years, the importance of TS for cancer initiation, development, local invasion and metastases has become increasingly clear allowing the identification of TS as one of the possible ways to indirectly target tumors. Inside the heterogeneous stromal cell population, tumor associated fibroblasts (TAF) play a crucial role providing both functional and supportive environments. During both tumor and stroma development, several findings suggest that TAF could be recruited from different sources such as locally derived host fibroblasts, via epithelial/endothelial mesenchymal transitions or from circulating pools of fibroblasts deriving form mesenchymal progenitors, namely mesenchymal stem/stromal cells (MSC). These insights prompted scientists to identify multimodal approaches to target TS by biomolecules, monoclonal antibodies, and more recently via cell based strategies. These latter strategies appear extremely promising, although still associated with debated and unclear findings. This review discusses crosstalk between cancers and their stroma, dissecting specific tumor types, such as sarcoma, pancreatic and breast carcinoma, where stroma plays distinct paradigmatic roles. The recognition of these distinct stromal functions may help in planning effective and safer approaches aimed either to eradicate or to substitute TS by novel compounds and/or MSC having specific killing activities. PMID:22016827

  20. Localization, Purification, and Characterization of Shikimate Oxidoreductase-Dehydroquinate Hydrolyase from Stroma of Spinach Chloroplasts 1

    PubMed Central

    Fiedler, Erich; Schultz, Gernot

    1985-01-01

    The stroma of chloroplasts is probably the sole site of the shikimate pathway enzymes shikimate oxidoreductase/dehydroquinate hydrolyase (SORase/DHQase) in spinach leaves. (a) The chromatographic behavior of the bifunctional protein SORase/DHQase on several separation materials with extracts from stroma compared with leaf extracts showed only one peak of enzymic activity originating from the stroma. (b) Polyacrylamide gel electrophoresis (PAGE) of these extracts followed by specific staining resulted in the same pattern without a band of extraplastidic enzyme. (c) In protoplast fractionation experiments it was shown that SORase/DHQase was present only in the soluble chloroplast protein fraction. An improved purification procedure for SORase/DHQase from stroma of chloroplasts, yield 40%, 1600 times as pure, gave essentially one protein band on sodium dodecyl sulfate-PAGE. Our results demonstrate that both enzyme functions are carried out by a single polypeptide. Nondenaturing PAGE exhibited a pattern of four bands with SORase/DHQase showing that they differ in charge but not in their molecular weight. Molecular weight was determined to be 67 kilodaltons (gel filtration) and 59 kilodaltons (PAGE) for all four forms. It was proven they were not due to artifacts. The four forms show similar kinetic properties, their Km and pH optima differing only very slightly. Response to some metabolites is reported. Images Fig. 3 Fig. 7 PMID:16664373

  1. TRP channels and STIM/ORAI proteins: sensors and effectors of cancer and stroma cell migration

    PubMed Central

    Nielsen, N; Lindemann, O; Schwab, A

    2014-01-01

    Cancer cells are strongly influenced by host cells within the tumour stroma and vice versa. This leads to the development of a tumour microenvironment with distinct physical and chemical properties that are permissive for tumour progression. The ability to migrate plays a central role in this mutual interaction. Migration of cancer cells is considered as a prerequisite for tumour metastasis and the migration of host stromal cells is required for reaching the tumour site. Increasing evidence suggests that transient receptor potential (TRP) channels and STIM/ORAI proteins affect key calcium-dependent mechanisms implicated in both cancer and stroma cell migration. These include, among others, cytoskeletal remodelling, growth factor/cytokine signalling and production, and adaptation to tumour microenvironmental properties such as hypoxia and oxidative stress. In this review, we will summarize the current knowledge regarding TRP channels and STIM/ORAI proteins in cancer and stroma cell migration. We focus on how TRP channel or STIM/ORAI-mediated Ca2+ signalling directly or indirectly influences cancer and stroma cell migration by affecting the above listed mechanisms. Linked Articles This article is part of a themed section on Cytoskeleton, Extracellular Matrix, Cell Migration, Wound Healing and Related Topics. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-24 PMID:24724725

  2. Inflammation as a Keystone of Bone Marrow Stroma Alterations in Primary Myelofibrosis

    PubMed Central

    Desterke, Christophe; Martinaud, Christophe; Ruzehaji, Nadira; Le Bousse-Kerdilès, Marie-Caroline

    2015-01-01

    Primary myelofibrosis (PMF) is a clonal myeloproliferative neoplasm where severity as well as treatment complexity is mainly attributed to a long lasting disease and presence of bone marrow stroma alterations as evidenced by myelofibrosis, neoangiogenesis, and osteosclerosis. While recent understanding of mutations role in hematopoietic cells provides an explanation for pathological myeloproliferation, functional involvement of stromal cells in the disease pathogenesis remains poorly understood. The current dogma is that stromal changes are secondary to the cytokine “storm” produced by the hematopoietic clone cells. However, despite therapies targeting the myeloproliferation-sustaining clones, PMF is still regarded as an incurable disease except for patients, who are successful recipients of allogeneic stem cell transplantation. Although the clinical benefits of these inhibitors have been correlated with a marked reduction in serum proinflammatory cytokines produced by the hematopoietic clones, further demonstrating the importance of inflammation in the pathological process, these treatments do not address the role of the altered bone marrow stroma in the pathological process. In this review, we propose hypotheses suggesting that the stroma is inflammatory-imprinted by clonal hematopoietic cells up to a point where it becomes “independent” of hematopoietic cell stimulation, resulting in an inflammatory vicious circle requiring combined stroma targeted therapies. PMID:26640324

  3. High levels of EGFR expression in tumor stroma are associated with aggressive clinical features in epithelial ovarian cancer

    PubMed Central

    Wang, Ke; Li, Dan; Sun, Lu

    2016-01-01

    Purpose The aim of this study was to investigate the clinical significance and biological function of epidermal growth factor receptor (EGFR) expressed in tumor stroma of epithelial ovarian cancer. Methods Immunohistological staining of EGFR was evaluated in 242 patients with epithelial ovarian cancer. The correlations of EGFR expression in tumor stroma with clinicopathological features and with the expression level of Ki-67 were analyzed by SPSS software. Kaplan–Meier analysis and the Cox proportional hazard model were used to analyze the effect of EGFR expression in tumor stroma on the prognosis of patients with epithelial ovarian cancer. Meanwhile, the activities of proliferation and migration of tumor cells were detected when EGFR overexpressed in stroma cells. Results EGFR expression in tumor stroma correlated significantly with clinical stage (χ2=7.002, P=0.008) and distant metastases (χ2=16.59, P<0.001). Furthermore, there was a significantly positive correlation between the level of EGFR expressed in tumor stroma and the level of Ki-67 expressed in tumor cells (χ2=6.120, P=0.013). Patients with high EGFR expression level in tumor stroma showed poor survival (P=0.002). Multivariate analysis showed that high expression of EGFR in tumor stroma was an independent predictor for epithelial ovarian cancer patients (hazard ratio =1.703; 95% confidence interval 1.125–2.578, P=0.012). Furthermore, stroma cells overexpressing EGFR could promote the proliferation and migration of adjacent tumor cells. Conclusion High expression of EGFR in tumor stroma correlates with aggressive clinical features in epithelial ovarian cancer, and is an independent prognostic factor. PMID:26855586

  4. Differential expression of miRNAs in pancreatobiliary type of periampullary adenocarcinoma and its associated stroma.

    PubMed

    Sandhu, V; Bowitz Lothe, I M; Labori, K J; Skrede, M L; Hamfjord, J; Dalsgaard, A M; Buanes, T; Dube, G; Kale, M M; Sawant, S; Kulkarni-Kale, U; Børresen-Dale, A-L; Lingjærde, O C; Kure, E H

    2016-02-01

    Periampullary adenocarcinomas can be of two histological subtypes, intestinal or pancreatobiliary. The latter is more frequent and aggressive, and characterized by a prominent desmoplastic stroma, which is tightly related to the biology of the cancer, including its poor response to chemotherapy. Whereas miRNAs are known to regulate various cellular processes and interactions between cells, their exact role in periampullary carcinoma remains to be characterized, especially with respect to the prominent stromal component of pancreatobiliary type cancers. The present study aimed at elucidating this role by miRNA expression profiling of the carcinomatous and stromal component in twenty periampullary adenocarcinomas of pancreatobiliary type. miRNA expression profiles were compared between carcinoma cells, stromal cells and normal tissue samples. A total of 43 miRNAs were found to be differentially expressed between carcinoma and stroma of which 11 belong to three miRNA families (miR-17, miR-15 and miR-515). The levels of expression of miRNAs miR-17, miR-20a, miR-20b, miR-223, miR-10b, miR-2964a and miR-342 were observed to be higher and miR-519e to be lower in the stromal component compared to the carcinomatous and normal components. They follow a trend where expression in stroma is highest followed by carcinoma and then normal tissue. Pathway analysis revealed that pathways regulating tumor-stroma interactions such as ECM interaction remodeling, epithelial-mesenchymal transition, focal adhesion pathway, TGF-beta, MAPK signaling, axon guidance and endocytosis were differently regulated. The miRNA-mRNA mediated interactions between carcinoma and stromal cells add new knowledge regarding tumor-stroma interactions. PMID:26590090

  5. Teleost fish scales: a unique biological model for the fabrication of materials for corneal stroma regeneration.

    PubMed

    Takagi, Yasuaki; Ura, Kazuhiro

    2007-03-01

    The corneal stroma is composed of multiple lamellae, each containing closely packed collagen fibrils. The orientation of fibrils in a lamella is parallel, but those in different lamellae are orthogonal. As a result, the corneal stroma has a characteristic orthogonal plywood-like structure. Such a highly-regulated three-dimensional arrangement of collagen fibrils gives strength and transparency to the corneal stroma, but it also presents a challenge in the fabrication of materials to replace it. A bioinspired technology is required to process such materials, but the regulatory mechanism of collagen-fibril orientation is still unknown. The low regenerating activity of the corneal stroma seems to be a major factor preventing progress in this field of research. A similarly highly-ordered arrangement of collagen fibrils can be seen in the basal plates of teleost fish scales. Moreover, the scales have high regenerating ability. When a scale is mechanically lost, a new scale is rapidly regenerated. The cells that produce the basal plates are extremely activated; thus, production of the highly-ordered collagen fibrils is very rapid. Therefore, the regenerating scales should be a uniquely helpful biological model for studying the regulatory mechanism of collagen-fibril orientation. Fish-scale collagen has another advantage for use as a biomaterial: the low probability of zoonotic infection. Therefore, scale collagen is a most promising biomaterial for fabricating three-dimensionally arranged collagen fibers to substitute for the corneal stroma. Three tasks that must be clarified for the bioinspired production of a corneal substitute from fish scale collagen are proposed. PMID:17450830

  6. New avenues for improving pancreatic ductal adenocarcinoma (PDAC) treatment: Selective stroma depletion combined with nano drug delivery.

    PubMed

    Bhaw-Luximon, Archana; Jhurry, Dhanjay

    2015-12-28

    The effectiveness of chemotherapy in PDAC is hampered by the dynamic interaction between stroma and cancer cell. The two opposing schools of thought - non-depletion of the stroma vs its depletion - to better drug efficacy are here discussed. Disrupting stroma-cancer cell interaction to reduce tumor progression and promote apoptosis is identified as the new direction of treatment for PDAC. Clinical data have shown that elimination of fibrosis and blockade of the Hedgehog pathway in stroma effectively promote drug delivery to tumor site and apoptosis. Reduced stiffness of ECM, lower fibrosis, higher permeability and higher blood flow after stroma depletion increase drug delivery. Combination strategies involving selective stroma depletion coupled with chemotherapy is currently proving to be the most efficient at clinical level. Striking the right balance between fibrosis depletion and angiogenesis promotion resulting in enhanced drug delivery and apoptosis is a major challenge. The use of nano drug delivery devices coupled with stroma depletion is emerging as the next phase treatment for PDAC. The breakthrough to combat PDAC will likely be a combination of early diagnosis and the emerging chemotherapy strategies. PMID:26415628

  7. Proteomics of the human endometrial glandular epithelium and stroma from the proliferative and secretory phases of the menstrual cycle.

    PubMed

    Hood, Brian L; Liu, Baoquan; Alkhas, Addie; Shoji, Yutaka; Challa, Rusheeswar; Wang, Guisong; Ferguson, Susan; Oliver, Julie; Mitchell, Dave; Bateman, Nicholas W; Zahn, Christopher M; Hamilton, Chad A; Payson, Mark; Lessey, Bruce; Fazleabas, Asgerally T; Maxwell, G Larry; Conrads, Thomas P; Risinger, John I

    2015-04-01

    Despite its importance in reproductive biology and women's health, a detailed molecular-level understanding of the human endometrium is lacking. Indeed, no comprehensive studies have been undertaken to elucidate the important protein expression differences between the endometrial glandular epithelium and surrounding stroma during the proliferative and midsecretory phases of the menstrual cycle. We utilized laser microdissection to harvest epithelial cells and stromal compartments from proliferative and secretory premenopausal endometrial tissue and performed a global, quantitative mass spectrometry-based proteomics analysis. This analysis identified 1224 total proteins from epithelial cells, among which 318 were differentially abundant between the proliferative and secretory phases (q < 0.05), and 1005 proteins from the stromal compartments, 19 of which were differentially abundant between the phases (q < 0.05). Several proteins were chosen for validation by immunohistochemistry in an independent set of uterine tissues, including carboxypeptidase M, tenascin C, neprilysin, and ectonucleotide pyrophosphatase/phosphodiesterase family member 3 (ENPP3). ENPP3, which was elevated in epithelial glandular cells in the secretory phase, was confirmed to be elevated in midsecretory-phase baboon uterine lavage samples and also observed to have an N-linked glycosylated form that was not observed in the proliferative phase. This study provides a detailed view into the global proteomic alterations of the epithelial cells and stromal compartments of the cycling premenopausal endometrium. These proteomic alterations during endometrial remodeling provide a basis for numerous follow-up investigations on the function of these differentially regulated proteins and their role in reproductive biology and endometrial pathologies. PMID:25695723

  8. Isolation of an immunosuppressive lectin from Phaseolus vulgaris L. cv Cacahuate using stroma.

    PubMed

    Vargas-Albores, F; Hernández, J; Córdoba, F; Zenteno, E

    1993-11-01

    An immunosuppressive lectin was isolated from seed of Phaseolus vulgaris cv Cacahuate using physically entrapped stroma. The lectin was found to be a 94 kDa tetrameric protein. When 50 micrograms, of this lectin were administered intraperitoneally 2 days before the immunization with sheep red blood cells, humoral response against the immunogen was completely inhibited. Other properties of the protein are discussed. PMID:8248029

  9. Normal stroma suppresses cancer cell proliferation via mechanosensitive regulation of JMJD1a-mediated transcription

    PubMed Central

    Kaukonen, Riina; Mai, Anja; Georgiadou, Maria; Saari, Markku; De Franceschi, Nicola; Betz, Timo; Sihto, Harri; Ventelä, Sami; Elo, Laura; Jokitalo, Eija; Westermarck, Jukka; Kellokumpu-Lehtinen, Pirkko-Liisa; Joensuu, Heikki; Grenman, Reidar; Ivaska, Johanna

    2016-01-01

    Tissue homeostasis is dependent on the controlled localization of specific cell types and the correct composition of the extracellular stroma. While the role of the cancer stroma in tumour progression has been well characterized, the specific contribution of the matrix itself is unknown. Furthermore, the mechanisms enabling normal—not cancer—stroma to provide tumour-suppressive signals and act as an antitumorigenic barrier are poorly understood. Here we show that extracellular matrix (ECM) generated by normal fibroblasts (NFs) is softer than the CAF matrix, and its physical and structural features regulate cancer cell proliferation. We find that normal ECM triggers downregulation and nuclear exit of the histone demethylase JMJD1a resulting in the epigenetic growth restriction of carcinoma cells. Interestingly, JMJD1a positively regulates transcription of many target genes, including YAP/TAZ (WWTR1), and therefore gene expression in a stiffness-dependent manner. Thus, normal stromal restricts cancer cell proliferation through JMJD1a-dependent modulation of gene expression. PMID:27488962

  10. Studies on the mechanism of edematous changes at the endometrial stroma for implantation.

    PubMed

    Okada, Y; Asahina, T; Kobayashi, T; Goto, J; Terao, T

    2001-01-01

    The endometrium undergoes edematous changes during the implantation period. Many factors may be involved in these biochemical reactions. We investigated the localization of inducible NO synthase (iNOS), interleukin-8 (IL-8), mast cell tryptase, neutrophil elastase, type III collagen, and CD44 in human endometrium. Immunohistochemical staining was performed by the labeled streptavidin-biotin method. iNOS was stained in the entire endometrial tissue from the midproliferative phase. The IL-8-positive cells, mast cells, and neutrophil elastase in the stroma increased toward the early to midsecretory phase. Type III collagen was arranged regularly in the stromal extracellular matrix during the proliferative phase; however, it was dissected during the secretory phase. CD44 was detected around stromal cells in the midsecretory phase. From these results, we propose the following mechanism. Initially, iNOS, expressed by the entire endometrial tissues from the midproliferative phase, catalyzes the production of NO. NO stimulates cells, supposed to be mast cells, to produce IL-8, which lets neutrophils migrate into the stroma. Neutrophils secrete elastase, which degrades type III collagen, generating spaces in the stroma. Hyaluronic acid adheres to CD44 around the stromal cells and retains water intermolecularly, finally forming the edematous matrix. PMID:11372773

  11. Normal stroma suppresses cancer cell proliferation via mechanosensitive regulation of JMJD1a-mediated transcription.

    PubMed

    Kaukonen, Riina; Mai, Anja; Georgiadou, Maria; Saari, Markku; De Franceschi, Nicola; Betz, Timo; Sihto, Harri; Ventelä, Sami; Elo, Laura; Jokitalo, Eija; Westermarck, Jukka; Kellokumpu-Lehtinen, Pirkko-Liisa; Joensuu, Heikki; Grenman, Reidar; Ivaska, Johanna

    2016-01-01

    Tissue homeostasis is dependent on the controlled localization of specific cell types and the correct composition of the extracellular stroma. While the role of the cancer stroma in tumour progression has been well characterized, the specific contribution of the matrix itself is unknown. Furthermore, the mechanisms enabling normal-not cancer-stroma to provide tumour-suppressive signals and act as an antitumorigenic barrier are poorly understood. Here we show that extracellular matrix (ECM) generated by normal fibroblasts (NFs) is softer than the CAF matrix, and its physical and structural features regulate cancer cell proliferation. We find that normal ECM triggers downregulation and nuclear exit of the histone demethylase JMJD1a resulting in the epigenetic growth restriction of carcinoma cells. Interestingly, JMJD1a positively regulates transcription of many target genes, including YAP/TAZ (WWTR1), and therefore gene expression in a stiffness-dependent manner. Thus, normal stromal restricts cancer cell proliferation through JMJD1a-dependent modulation of gene expression. PMID:27488962

  12. An imported thylakoid protein accumulates in the stroma when insertion into thylakoids is inhibited.

    PubMed

    Cline, K; Fulsom, D R; Viitanen, P V

    1989-08-25

    The light-harvesting chlorophyll a/b protein (LHCP) is synthesized in the cytosol as a precursor (pLHCP) that is imported into chloroplasts and assembled into thylakoid membranes. Under appropriate conditions, either pLHCP or LHCP will integrate into isolated thylakoids. We have identified two situations that inhibit integration in this assay. Ionophores and uncouplers inhibited integration up to 70%. Carboxyl-terminal truncations of pLHCP also interfered with integration. A 22-residue truncation reduced integration to about 25% of control, whereas a 93 residue truncation completely abolished it. When pLHCP was imported into chloroplasts in the presence of uncouplers or when truncated forms of pLHCP were used, significant amounts of the imported proteins failed to insert into thylakoids and instead accumulated in the aqueous stroma. Accumulation of stromal LHCP occurred at uncoupler concentrations required to dissipate the trans-thylakoid proton electrochemical gradient and was enhanced at reduced levels of ATP. The latter effect may be a secondary consequence of a reduction in ATP-dependent degradation within the stroma. These results indicate that the stroma is an intermediate location in the LHCP assembly pathway and provide the first evidence for a soluble intermediate during biogenesis of a chloroplast membrane protein. PMID:2668283

  13. Digital histologic analysis reveals morphometric patterns of age-related involution in breast epithelium and stroma.

    PubMed

    Sandhu, Rupninder; Chollet-Hinton, Lynn; Kirk, Erin L; Midkiff, Bentley; Troester, Melissa A

    2016-02-01

    Complete age-related regression of mammary epithelium, often termed postmenopausal involution, is associated with decreased breast cancer risk. However, most studies have qualitatively assessed involution. We quantitatively analyzed epithelium, stroma, and adipose tissue from histologically normal breast tissue of 454 patients in the Normal Breast Study. High-resolution digital images of normal breast hematoxylin and eosin-stained slides were partitioned into epithelium, adipose tissue, and nonfatty stroma. Percentage area and nuclei per unit area (nuclear density) were calculated for each component. Quantitative data were evaluated in association with age using linear regression and cubic spline models. Stromal area decreased (P = 0.0002), and adipose tissue area increased (P < 0.0001), with an approximate 0.7% change in area for each component, until age 55 years when these area measures reached a steady state. Although epithelial area did not show linear changes with age, epithelial nuclear density decreased linearly beginning in the third decade of life. No significant age-related trends were observed for stromal or adipose nuclear density. Digital image analysis offers a high-throughput method for quantitatively measuring tissue morphometry and for objectively assessing age-related changes in adipose tissue, stroma, and epithelium. Epithelial nuclear density is a quantitative measure of age-related breast involution that begins to decline in the early premenopausal period. PMID:26772400

  14. A novel method in preparation of acellularporcine corneal stroma tissue for lamellar keratoplasty

    PubMed Central

    Shao, Yi; Tang, Jing; Zhou, Yueping; Qu, Yangluowa; He, Hui; Liu, Qiuping; Tan, Gang; Li, Wei; Liu, Zuguo

    2015-01-01

    Our objective was to develop a novel lamellar cornealbiomaterial for corneal reconstruction.Theporcine acellular corneal stroma discs (ACSDs) were prepared from de-epithelized fresh porcine corneas (DFPCs) by incubation with 100% fresh human serum and additional electrophoresis at 4°C. Such manipulation removed theanterior corneal stromal cells without residual of DNA content and α-Galantigen. Human serum decellularizing activity on porcineanterior corneal stroma cells is through apoptosis, and associated with the presence of α-Gal epitopes in anterior stroma. ACSDs displayed similar optical, biomechanical properties and ultrastructure to DFPCs, and showed good histocompatibility in rabbit corneal stromal pockets and anterior chamber. Rabbit corneallamellar keratoplasty (LKP) using ACSDs showed no rejection and high transparency of cornea at 2 months after surgery. In vivo confocal laser scanning microscopy and immunostaining analysis showed complete re-epithelization and stromal cell in growth of ACSDs without inflammatory cell infiltration, new blood vessel ingrowth and excessive wound healing. In conclusion, this novel decellularization method may be valuable for preparation of xenogenic corneal tissue for clinical application, ACSDs resulted from this method may be served as a matrix equivalent for LKP in corneal xenotransplantation. PMID:26885261

  15. Targeting the leukemia–stroma interaction in acute myeloid leukemia: rationale and latest evidence

    PubMed Central

    Rashidi, Armin; DiPersio, John F.

    2016-01-01

    The concept of ‘niche’ has become a focus of attention in hematologic malignancies including acute myeloid leukemia (AML). Similar to normal hematopoietic stem cells, AML cells interact both anatomically and functionally with the stroma within the marrow microenvironment. These interactions have a critical role in the development, progression, and relapse of AML. Chemotherapy resistance is another feature that is at least partially related to AML–stroma interactions. The evidence for safety and efficacy of agents targeting AML–niche interactions is currently limited to preclinical and early phase clinical studies. Examples include CXCR4 inhibitors, hypoxia-inducible agents, and adhesion molecule inhibitors. Agents that target AML–stroma interactions differ from mutation-specific approaches that tend to be limited due to within-individual and between-individual genetic heterogeneity. These agents may be used alone or as chemosensitizers in AML. This novel and rapidly advancing strategy is likely to become an important part of our armamentarium of anti-leukemia treatments in the near future. PMID:26834953

  16. GT198 Expression Defines Mutant Tumor Stroma in Human Breast Cancer.

    PubMed

    Yang, Zheqiong; Peng, Min; Cheng, Liang; Jones, Kimya; Maihle, Nita J; Mivechi, Nahid F; Ko, Lan

    2016-05-01

    Human breast cancer precursor cells remain to be elucidated. Using breast cancer gene product GT198 (PSMC3IP; alias TBPIP or Hop2) as a unique marker, we revealed the cellular identities of GT198 mutant cells in human breast tumor stroma. GT198 is a steroid hormone receptor coactivator and a crucial factor in DNA repair. Germline mutations in GT198 are present in breast and ovarian cancer families. Somatic mutations in GT198 are present in ovarian tumor stromal cells. Herein, we show that human breast tumor stromal cells carry GT198 somatic mutations and express cytoplasmic GT198 protein. GT198(+) stromal cells share vascular smooth muscle cell origin, including myoepithelial cells, adipocytes, capillary pericytes, and stromal fibroblasts. Frequent GT198 mutations are associated with GT198(+) tumor stroma but not with GT198(-) tumor cells. GT198(+) progenitor cells are mostly capillary pericytes. When tested in cultured cells, mutant GT198 induces vascular endothelial growth factor promoter, and potentially promotes angiogenesis and adipogenesis. Our results suggest that multiple lineages of breast tumor stromal cells are mutated in GT198. These findings imply the presence of mutant progenitors, whereas their descendants, carrying the same GT198 mutations, are collectively responsible for forming breast tumor microenvironment. GT198 expression is, therefore, a specific marker of mutant breast tumor stroma and has the potential to facilitate diagnosis and targeted treatment of human breast cancer. PMID:27001628

  17. Gangliosides of myelosupportive stroma cells are transferred to myeloid progenitors and are required for their survival and proliferation

    PubMed Central

    Ziulkoski, Ana L.; Andrade, Cláudia M. B.; Crespo, Pilar M.; Sisti, Elisa; Trindade, Vera M. T.; Daniotti, Jose L.; Guma, Fátima C. R.; Borojevic, Radovan

    2005-01-01

    In previous studies, we have shown that the myelopoiesis dependent upon myelosupportive stroma required production of growth factors and heparan-sulphate proteoglycans, as well as generation of a negatively charged sialidase-sensitive intercellular environment between the stroma and the myeloid progenitors. In the present study, we have investigated the production, distribution and role of gangliosides in an experimental model of in vitro myelopoiesis dependent upon AFT-024 murine liver-derived stroma. We used the FDC-P1 cell line, which is dependent upon GM-CSF (granulocyte/macrophage colony-stimulating factor) for both survival and proliferation, as a reporter system to monitor bioavailability and local activity of GM-CSF. GM3 was the major ganglioside produced by stroma, but not by myeloid cells, and it was required for optimal stroma myelosupportive function. It was released into the supernatant and selectively incorporated into the myeloid progenitor cells, where it segregated into rafts in which it co-localized with the GM-CSF-receptor α chain. This ganglioside was also metabolized further by myeloid cells into gangliosides of the a and b series, similar to endogenous GM3. In these cells, GM1 was the major ganglioside and it was segregated at the interface by stroma and myeloid cells, partially co-localizing with the GM-CSF-receptor α chain. We conclude that myelosupportive stroma cells produce and secrete the required growth factors, the cofactors such as heparan sulphate proteoglycans, and also supply gangliosides that are transferred from stroma to target cells, generating on the latter ones specific membrane domains with molecular complexes that include growth factor receptors. PMID:16321139

  18. Follicular thyroid carcinoma characterized by abundant stromal components with chondroid and osseous metaplasia in a dog.

    PubMed

    Kobayashi, Ryosuke; Yamada, Naoaki; Kitamori, Takashi; Kitamori, Fumiyo; Sato, Kazunari; Doi, Takuya; Wako, Yumi; Sato, Junko; Tsuchitani, Minoru

    2014-08-01

    A dog developed a cervical mass, and computed tomography verified a mass surrounding the trachea with some pulmonary masses. Histopathologically, the cervical mass was composed of malignant neoplastic cells showing follicular appearance which reacted positive for thyroglobulin on immunohistochemistry. A characteristic feature of the tumor was abundant and metaplastic stromal components. Anastomosed collagenous tissues connecting to capsule of the tumor were abundant in the stroma. In parts of the collagenous tissues, mature cartilages and bones were continuously formed. There was no cellular atypia or invasion in the components. We diagnosed this case as follicular thyroid carcinoma with metaplastic stroma. This is the first case report that characterizes stromal components with chondroid and osseous metaplasia in a canine thyroid carcinoma. PMID:24805905

  19. Keratinocyte-Derived Chemokine Induces Prostate Epithelial Hyperplasia and Reactive Stroma in a Novel Transgenic Mouse Model

    PubMed Central

    Schauer, Isaiah G.; Ressler, Steven J.; Rowley, David R.

    2009-01-01

    Background Interleukin-8 (IL-8) is upregulated in fibrotic and malignant diseases and is a key mediator of proliferative responses. Elevated IL-8 was recently correlated with benign prostatic hyperplasia epithelium and a myofibroblast reactive stroma. Thus, we sought to determine whether overexpressed IL-8 and keratinocyte-derived chemokine (KC), the functional murine homolog of IL-8, induce prostate epithelial hyperplasia and a reactive phenotype. Methods Transgenic mice that overexpress KC within prostate epithelia and xenograft models with engineered human cells that overexpress IL-8 were developed. Results Overexpression of KC in transgenic mice produced hyperplastic prostate epithelial acini associated with a periacinar reactive stroma. KC induced an altered epithelial/stroma proliferation index ratio, increased acini diameter, epithelial infolding, and expression of prototypical reactive stroma markers. Overexpression of IL-8 in normal human prostate epithelial xenografts correlated with elevated epithelial proliferation index and altered morphology. Elevated human prostate stromal and epithelial cell proliferation, nodule-like morphology and increased xenograft survival were observed in IL-8-overexpressing orthotopic xenografts. Conclusions Together, these data demonstrate that overexpression of IL-8/KC results in a prostate epithelial hyperplasia with an associated reactive stroma phenotype. The novel transgenic mouse and human xenograft models described here may be useful in dissecting key mechanisms of IL-8 induced prostate hyperplasia and reactive stroma. PMID:19021203

  20. Reproductive age-associated fibrosis in the stroma of the mammalian ovary.

    PubMed

    Briley, Shawn M; Jasti, Susmita; McCracken, Jennifer M; Hornick, Jessica E; Fegley, Barbara; Pritchard, Michele T; Duncan, Francesca E

    2016-09-01

    Under normal physiological conditions, tissue remodeling in response to injury leads to tissue regeneration without permanent damage. However, if homeostasis between synthesis and degradation of extracellular matrix (ECM) components is altered, fibrosis - or the excess accumulation of ECM - can disrupt tissue architecture and function. Several organs, including the heart, lung and kidney, exhibit age-associated fibrosis. Here we investigated whether fibrosis underlies aging in the ovary - an organ that ages chronologically before other organs. We used Picrosirius Red (PSR), a connective tissue stain specific for collagen I and III fibers, to evaluate ovarian fibrosis. Using bright-field, epifluorescence, confocal and polarized light microscopy, we validated the specific staining of highly ordered PSR-stained fibers in the ovary. We next examined ovarian PSR staining in two mouse strains (CD1 and CB6F1) across an aging continuum and found that PSR staining was minimal in ovaries from reproductively young adult animals, increased in distinct foci in animals of mid-to-advanced reproductive age, and was prominent throughout the stroma of the oldest animals. Consistent with fibrosis, there was a reproductive age-associated increase in ovarian hydroxyproline content. We also observed a unique population of multinucleated macrophage giant cells, which are associated with chronic inflammation, within the ovarian stroma exclusively in reproductively old mice. In fact, several genes central to inflammation had significantly higher levels of expression in ovaries from reproductively old mice relative to young mice. These results establish fibrosis as an early hallmark of the aging ovarian stroma, and this altered microenvironment may contribute to the age-associated decline in gamete quality. PMID:27491879

  1. Antagonizing the Hedgehog Pathway with Vismodegib Impairs Malignant Pleural Mesothelioma Growth In Vivo by Affecting Stroma.

    PubMed

    Meerang, Mayura; Bérard, Karima; Felley-Bosco, Emanuela; Lauk, Olivia; Vrugt, Bart; Boss, Andreas; Kenkel, David; Broggini-Tenzer, Angela; Stahel, Rolf A; Arni, Stephan; Weder, Walter; Opitz, Isabelle

    2016-05-01

    An autocrine-driven upregulation of the Hedgehog (Hh) signaling pathway has been described in malignant pleural mesothelioma (MPM), in which the ligand, desert Hh (DHH), was produced from tumor cells. However, our investigation revealed that the Hh pathway is activated in both tumor and stroma of MPM tumor specimens and an orthotopic immunocompetent rat MPM model. This was demonstrated by positive immunohistochemical staining of Glioma-associated oncogene 1 (GLI1) and Patched1 (PTCH1) in both tumor and stromal fractions. DHH was predominantly expressed in the tumor fractions. To further investigate the role of the Hh pathway in MPM stroma, we antagonized Hh signaling in the rat model of MPM using a Hh antagonist, vismodegib, (100 mg/kg orally). Daily treatment with vismodegib efficiently downregulated Hh target genes Gli1, Hedgehog Interacting Protein (Hhip), and Ptch1, and caused a significant reduction of tumor volume and tumor growth delay. Immunohistochemical analyses revealed that vismodegib treatment primarily downregulated GLI1 and HHIP in the stromal compartment along with a reduced expression of previously described fibroblast Hh-responsive genes such as Fibronectin (Fn1) and Vegfa Primary cells isolated from the rat model cultured in 3% O2 continued to express Dhh but did not respond to vismodegib in vitro However, culture supernatant from these cells stimulated Gli1, Ptch1, and Fn1 expression in mouse embryonic fibroblasts, which was suppressed by vismodegib. Our study provides new evidence regarding the role of Hh signaling in MPM stroma in the maintenance of tumor growth, emphasizing Hh signaling as a treatment target for MPM. Mol Cancer Ther; 15(5); 1095-105. ©2016 AACR. PMID:26839306

  2. Columnar cell lesions and pseudoangiomatous hyperplasia like stroma: is there an epithelial-stromal interaction?

    PubMed

    Recavarren, Rosemary A; Chivukula, Mamatha; Carter, Gloria; Dabbs, David J

    2009-01-01

    The significance of association between cancer and its microenvironment has been increasingly recognized. It has been shown in animal models that interaction between neoplastic epithelial cells and adjacent stroma can modulate tumor behavior. Carcinoma associated stromal cells can transform normal epithelial cells into neoplastic cells. In breast, columnar cell lesions are non-obligate precursors of low grade ductal carcinoma in situ. Columnar cell lesions can be seen intimately associated with PASH-like-stroma, a lesion we termed as CCPLS. Our aim is to investigate epithelial-stromal interactions in CCPLS and compare them to PASH without columnar cell lesions in breast core needle biopsies. Normal terminal duct lobular unit (TDLU) epithelium was seen in association with columnar cell lesions as well as PASH. Eight (8) cases of each category were examined by a panel of immunostains: CD117 (C-kit), CD34, CD105, bFGF, AR, ER-beta, MIB-1. We observed a markedly decreased expression of c-kit in columnar cell lesions compared to TDLU-epithelium. CD105 showed a quantitative increase in activated vessels in CCPLS compared to PASH. A subset of CCPLS and PASH were androgen receptor positive. A strong nuclear positivity for ER-beta is observed in the epithelium and stroma of all CCPLS cases. We conclude that (1) activated blood vessels predominate in CCPLS; (2) A molecular alteration is signified by c-kit loss in columnar cell lesions; (3) ER-beta and androgen receptor positivity indicate CCPLS are hormonally responsive lesions. Our study suggests an intimate vascular and hormone dependent epithelial-stromal interaction exists in CCPLS lesions. PMID:19918332

  3. Altered Proteomic Polymorphisms in the Caterpillar Body and Stroma of Natural Cordyceps sinensis during Maturation

    PubMed Central

    Wu, Zi-Mei; Gao, Ling; Yao, Yi-Sang; Tan, Ning-Zhi; Wu, Jian-Yong; Ni, Luqun; Zhu, Jia-Shi

    2014-01-01

    Objective To examine the maturational changes in proteomic polymorphisms resulting from differential expression by multiple intrinsic fungi in the caterpillar body and stroma of natural Cordyceps sinensis (Cs), an integrated micro-ecosystem. Methods The surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) biochip technique was used to profile the altered protein compositions in the caterpillar body and stroma of Cs during its maturation. The MS chromatograms were analyzed using density-weighted algorithms to examine the similarities and cluster relationships among the proteomic polymorphisms of the Cs compartments and the mycelial products Hirsutella sinensis (Hs) and Paecilomyces hepiali (Ph). Results: SELDI-TOF MS chromatograms displayed dynamic proteomic polymorphism alterations among samples from the different Cs compartments during maturation. More than 1,900 protein bands were analyzed using density-weighted ZUNIX similarity equations and clustering methods, revealing integral polymorphism similarities of 57.4% between the premature and mature stromata and 42.8% between the premature and mature caterpillar bodies. The across-compartment similarity was low, ranging from 10.0% to 18.4%. Consequently, each Cs compartment (i.e., the stroma and caterpillar body) formed a clustering clade, and the 2 clades formed a Cs cluster. The polymorphic similarities ranged from 0.51% to 1.04% between Hs and the Cs compartments and were 2.8- to 4.8-fold higher (1.92%–4.34%) between Ph and the Cs compartments. The Hs and Ph mycelial samples formed isolated clades outside of the Cs cluster. Conclusion Proteomic polymorphisms in the caterpillar body and stroma of Cs change dynamically during maturation. The proteomic polymorphisms in Hs and Ph differ from those in Cs, suggesting the presence of multiple Cs-associated fungi and multiple Ophiocordyceps sinensis genotypes with altered differential protein expression in the Cs compartments

  4. Tamoxifen induces pleiotrophic changes in mammary stroma resulting in extracellular matrix that suppresses transformed phenotypes

    PubMed Central

    Hattar, Rhonda; Maller, Ori; McDaniel, Shauntae; Hansen, Kirk C; Hedman, Karla J; Lyons, Traci R; Lucia, Scott; Wilson, R Storey; Schedin, Pepper

    2009-01-01

    Introduction The functional unit of the mammary gland has been defined as the epithelial cell plus its microenvironment, a hypothesis that predicts changes in epithelial cell function will be accompanied by concurrent changes in mammary stroma. To test this hypothesis, the question was addressed of whether mammary stroma is functionally altered by the anti-oestrogen drug tamoxifen. Methods Forty female rats at 70 days of age were randomised to two groups of 20 and treated with 1.0 mg/kg tamoxifen or vehicle subcutaneously daily for 30 days, followed by a three-day wash out period. Mammary tissue was harvested and effects of tamoxifen on mammary epithelium and stroma determined. Results As expected, tamoxifen suppressed mammary alveolar development and mammary epithelial cell proliferation. Primary mammary fibroblasts isolated from tamoxifen-treated rats displayed a three-fold decrease in motility and incorporated less fibronectin in their substratum in comparison to control fibroblasts; attributes indicative of fibroblast quiescence. Immunohistochemistry analysis of CD68, a macrophage lysosomal marker, demonstrated a reduction in macrophage infiltration in mammary glands of tamoxifen-treated rats. Proteomic analyses by mass spectrometry identified several extracellular matrix (ECM) proteins with expression levels with tamoxifen treatment that were validated by Western blot. Mammary tissue from tamoxifen-treated rats had decreased fibronectin and increased collagen 1 levels. Further, ECM proteolysis was reduced in tamoxifen-treated rats as detected by reductions in fibronectin, laminin 1, laminin 5 and collagen 1 cleavage fragments. Consistent with suppression in ECM proteolysis with tamoxifen treatment, matrix metalloproteinase-2 levels and activity were decreased. Biochemically extracted mammary ECM from tamoxifen-treated rats suppressed in vitro macrophage motility, which was rescued by the addition of proteolysed collagen or fibronectin. Mammary ECM from

  5. Biliary cystadenoma with mesenchymal stroma: Report of a case and review of the literature

    PubMed Central

    Manouras, Andreas; Markogiannakis, Haridimos; Lagoudianakis, Emmanuel; Katergiannakis, Vangelogiannis

    2006-01-01

    Biliary cystadenomas are rare, cystic neoplasms of the biliary ductal system that usually occur in middle-aged women. They cannot be safely differentiated from cystadenocarcinomas before operation and should always be considered for resection. Cystadenomas have a strong tendency to recur, particularly following incomplete excision, and a potential of malignant transformation. Therefore, complete resection is the therapy of choice and thorough histopathologic evaluation is imperative. A case of benign biliary cystadenoma with mesenchymal stroma is presented along with a review of the relative literature addressing the clinical presentation, histology, histogenesis, differential diagnosis, imaging features, treatment and prognosis of this interesting and rare entity. PMID:17009411

  6. HSP90 inhibition blocks ERBB3 and RET phosphorylation in myxoid/round cell liposarcoma and causes massive cell death in vitro and in vivo

    PubMed Central

    Safavi, Setareh; Järnum, Sofia; Vannas, Christoffer; Udhane, Sameer; Jonasson, Emma; Tomic, Tajana Tesan; Grundevik, Pernilla; Fagman, Henrik; Hansson, Magnus; Kalender, Zeynep; Jauhiainen, Alexandra; Dolatabadi, Soheila; Stratford, Eva Wessel; Myklebost, Ola; Eriksson, Mikael; Stenman, Göran; Stock, Regine Schneider; Ståhlberg, Anders; Åman, Pierre

    2016-01-01

    Myxoid sarcoma (MLS) is one of the most common types of malignant soft tissue tumors. MLS is characterized by the FUS-DDIT3 or EWSR1-DDIT3 fusion oncogenes that encode abnormal transcription factors. The receptor tyrosine kinase (RTK) encoding RET was previously identified as a putative downstream target gene to FUS-DDIT3 and here we show that cultured MLS cells expressed phosphorylated RET together with its ligand Persephin. Treatment with RET specific kinase inhibitor Vandetanib failed to reduce RET phosphorylation and inhibit cell growth, suggesting that other RTKs may phosphorylate RET. A screening pointed out EGFR and ERBB3 as the strongest expressed phosphorylated RTKs in MLS cells. We show that ERBB3 formed nuclear and cytoplasmic complexes with RET and both RTKs were previously reported to form complexes with EGFR. The formation of RTK hetero complexes could explain the observed Vandetanib resistence in MLS. EGFR and ERBB3 are clients of HSP90 that help complex formation and RTK activation. Treatment of cultured MLS cells with HSP90 inhibitor 17-DMAG, caused loss of RET and ERBB3 phosphorylation and lead to rapid cell death. Treatment of MLS xenograft carrying Nude mice resulted in massive necrosis, rupture of capillaries and hemorrhages in tumor tissues. We conclude that complex formation between RET and other RTKs may cause RTK inhibitor resistance. HSP90 inhibitors can overcome this resistance and are thus promising drugs for treatment of MLS/RCLS. PMID:26595521

  7. Extraskeletal myxoid chondrosarcoma with a t(9;16)(q22;p11.2) resulting in a NR4A3-FUS fusion.

    PubMed

    Broehm, Cory J; Wu, Jin; Gullapalli, Rama R; Bocklage, Thèrése

    2014-06-01

    Extraskeletal myxoid chondrosarcoma (EMC) is a rare neoplasm characterized by rearrangement of NR4A3. A t(9;22)(q22;q12), creating a fusion protein of EWSR1 and NR4A3, has been reported as a unique, recurring translocation in most cases. Reported variant translocations have resulted in fusion of NR4A3 with three other genes: TAF15, TCF12, and TFG. We report a case of EMC in a 59-year-old man who presented with a 6-month history of an enlarging mass in the proximal right thigh. The karyotype of fresh tissue from tumor taken at incisional biopsy revealed a t(9;16)(q22;p11.2). There was no evidence of an EWSR1 rearrangement by dual-color break-apart fluorescence in situ hybridization (FISH). Dual-color FISH probes revealed fusion of NR4A3 and FUS, a member of the TET family of genes, which includes EWSR1 and TAF15. Break-apart FISH probe results confirmed rearrangement of FUS. These findings show that a fusion product of FUS and NR4A3 may be an additional pathway to development of EMC. PMID:25130955

  8. Multiphoton imaging to identify grana, stroma thylakoid, and starch inside an intact leaf

    PubMed Central

    2014-01-01

    Background Grana and starch are major functional structures for photosynthesis and energy storage of plant, respectively. Both exhibit highly ordered molecular structures and appear as micrometer-sized granules inside chloroplasts. In order to distinguish grana and starch, we used multiphoton microscopy, with simultaneous acquisition of two-photon fluorescence (2PF) and second harmonic generation (SHG) signals. SHG is sensitive to crystallized structures while 2PF selectively reveals the distribution of chlorophyll. Result Three distinct microstructures with different contrasts were observed, i.e. “SHG dominates”, “2PF dominates”, and “SHG collocated with 2PF”. It is known that starch and grana both emit SHG due to their highly crystallized structures, and no autofluorescence is emitted from starch, so the “SHG dominates” contrast should correspond to starch. The contrast of “SHG collocated with 2PF” is assigned to be grana, which exhibit crystallized structure with autofluorescent chlorophyll. The “2PF dominates” contrast should correspond to stroma thylakoid, which is a non-packed membrane structure with chrolophyll. The contrast assignment is further supported by fluorescence lifetime measurement. Conclusion We have demonstrated a straightforward and noninvasive method to identify the distribution of grana and starch within an intact leaf. By merging the 2PF and SHG images, grana, starch and stroma thylakoid can be visually distinguished. This approach can be extended to the observation of 3D grana distribution and their dynamics in living plants. PMID:24969621

  9. Distinct subpopulations of FOXD1 stroma-derived cells regulate renal erythropoietin.

    PubMed

    Kobayashi, Hanako; Liu, Qingdu; Binns, Thomas C; Urrutia, Andres A; Davidoff, Olena; Kapitsinou, Pinelopi P; Pfaff, Andrew S; Olauson, Hannes; Wernerson, Annika; Fogo, Agnes B; Fong, Guo-Hua; Gross, Kenneth W; Haase, Volker H

    2016-05-01

    Renal peritubular interstitial fibroblast-like cells are critical for adult erythropoiesis, as they are the main source of erythropoietin (EPO). Hypoxia-inducible factor 2 (HIF-2) controls EPO synthesis in the kidney and liver and is regulated by prolyl-4-hydroxylase domain (PHD) dioxygenases PHD1, PHD2, and PHD3, which function as cellular oxygen sensors. Renal interstitial cells with EPO-producing capacity are poorly characterized, and the role of the PHD/HIF-2 axis in renal EPO-producing cell (REPC) plasticity is unclear. Here we targeted the PHD/HIF-2/EPO axis in FOXD1 stroma-derived renal interstitial cells and examined the role of individual PHDs in REPC pool size regulation and renal EPO output. Renal interstitial cells with EPO-producing capacity were entirely derived from FOXD1-expressing stroma, and Phd2 inactivation alone induced renal Epo in a limited number of renal interstitial cells. EPO induction was submaximal, as hypoxia or pharmacologic PHD inhibition further increased the REPC fraction among Phd2-/- renal interstitial cells. Moreover, Phd1 and Phd3 were differentially expressed in renal interstitium, and heterozygous deficiency for Phd1 and Phd3 increased REPC numbers in Phd2-/- mice. We propose that FOXD1 lineage renal interstitial cells consist of distinct subpopulations that differ in their responsiveness to Phd2 inactivation and thus regulation of HIF-2 activity and EPO production under hypoxia or conditions of pharmacologic or genetic PHD inactivation. PMID:27088801

  10. On Orbit Osteobiology Experiments: from "STROMA" to "MDS" -from in vitro to in vivo

    NASA Astrophysics Data System (ADS)

    Liu, Yi; Cancedda, Ranieri

    Spaceflight causes profound changes in the skeleton, in particular, in the weight-loading bones. Uncoupling of bone remodeling equilibrium between bone formation and resorption is con-sidered responsible for the microgravity-induced bone loss. These changes result in weak-ened and brittle bones prone to fracture on re-entry and in accelerated osteoporosis, making bone deterioration a major problem obstructing the prospects of long-duration manned space flight. Osteoblasts (bone forming cells) and osteocytes (bone resorption cells) are known to be mechano-sensors. Short-exposure of osteoblasts to simulated microgravity ensnarled cell adhe-sion and cytoskeleton. Also osteoblast precursors such as bone marrow stroma cells (BMSC) were shown to be sensitive to mechanical loading. We performed a series of STROMA space-flight experiments by culturing BMSC or co-culturing osteoblasts and osteoclast precursors in automated bioreactors on orbit. Genechip analysis revealed an inhibition of cell proliferation and an unexpected activation of nervous system development genes by spaceflight. To unravel effects of microgravity on genes governing bone mass, transgenic mice with a higher bone mass were flown to orbit inside the Mice Drawer System (MDS) payload. The MDS experiment was launched inside Shuttle Discovery in STS-128 on August 28 2009 at 23:58 EST, and returned to earth by Shuttle Atlantis in STS129 on November 27 2009 at 9:47 EST, marking it as the first long duration animal experiment on the International Space Station (ISS).

  11. Stroma provides an intestinal stem cell niche in the absence of epithelial Wnts.

    PubMed

    Kabiri, Zahra; Greicius, Gediminas; Madan, Babita; Biechele, Steffen; Zhong, Zhendong; Zaribafzadeh, Hamed; Edison; Aliyev, Jamal; Wu, Yonghui; Bunte, Ralph; Williams, Bart O; Rossant, Janet; Virshup, David M

    2014-06-01

    Wnt/β-catenin signaling supports intestinal homeostasis by regulating proliferation in the crypt. Multiple Wnts are expressed in Paneth cells as well as other intestinal epithelial and stromal cells. Ex vivo, Wnts secreted by Paneth cells can support intestinal stem cells when Wnt signaling is enhanced with supplemental R-Spondin 1 (RSPO1). However, in vivo, the source of Wnts in the stem cell niche is less clear. Genetic ablation of Porcn, an endoplasmic reticulum resident O-acyltransferase that is essential for the secretion and activity of all vertebrate Wnts, confirmed the role of intestinal epithelial Wnts in ex vivo culture. Unexpectedly, mice lacking epithelial Wnt activity (Porcn(Del)/Villin-Cre mice) had normal intestinal proliferation and differentiation, as well as successful regeneration after radiation injury, indicating that epithelial Wnts are dispensable for these processes. Consistent with a key role for stroma in the crypt niche, intestinal stromal cells endogenously expressing Wnts and Rspo3 support the growth of Porcn(Del) organoids ex vivo without RSPO1 supplementation. Conversely, increasing pharmacologic PORCN inhibition, affecting both stroma and epithelium, reduced Lgr5 intestinal stem cells, inhibited recovery from radiation injury, and at the highest dose fully blocked intestinal proliferation. We conclude that epithelial Wnts are dispensable and that stromal production of Wnts can fully support normal murine intestinal homeostasis. PMID:24821987

  12. Regulation of dendritic-cell differentiation by bone marrow stroma via different Notch ligands

    PubMed Central

    Cheng, Pingyan; Nefedova, Yulia; Corzo, Cesar A.; Gabrilovich, Dmitry I.

    2007-01-01

    Notch is a major factor mediating interaction between hematopoietic progenitor cells (HPCs) and bone marrow stroma (BMS). However its contribution to dendritic cell (DC) differentiation is controversial. We found that main Notch ligands Delta-1 and Jagged-1 had the opposite effect on DC differentiation. Delta-1 promoted generation of fully differentiated DCs, whereas Jagged-1 stimulated accumulation of DC precursors but prevented their transition to terminally differentiated DCs. BMS expressed a substantially higher level of Jagged-1 than Delta-1. Just the opposite expression pattern was observed in spleen stroma (SS). The BMS effect on DC differentiation was similar to that of Jagged-1, whereas the effect of SS was similar to the effect of Delta-1. Down-regulation of Jagged-1 in BMS substantially increased DC differentiation. Experiments in vivo with adoptive transfer of DC precursors further supported the different roles of BMS and SS in DC development. Jagged-1 and Delta-1 equally activated CBF-1/RBPJκ transcription factor, which is a major Notch target. However, they produced a different pattern of activation of Notch target gene Hes1. Overexpression of Hes1 resulted in increased DC differentiation from HPCs. Thus, this study not only revealed the different role of Notch ligands in DC differentiation but also may provide a new insight into regulation of DC differentiation by BMS. PMID:16973960

  13. Gene Expression Analysis of In Vitro Cocultures to Study Interactions between Breast Epithelium and Stroma

    PubMed Central

    Casbas-Hernandez, Patricia; Fleming, Jodie M.; Troester, Melissa A.

    2011-01-01

    The interactions between breast epithelium and stroma are fundamental to normal tissue homeostasis and for tumor initiation and progression. Gene expression studies of in vitro coculture models demonstrate that in vitro models have relevance for tumor progression in vivo. For example, stromal gene expression has been shown to vary in association with tumor subtype in vivo, and analogous in vitro cocultures recapitulate subtype-specific biological interactions. Cocultures can be used to study cancer cell interactions with specific stromal components (e.g., immune cells, fibroblasts, endothelium) and different representative cell lines (e.g., cancer-associated versus normal-associated fibroblasts versus established, immortalized fibroblasts) can help elucidate the role of stromal variation in tumor phenotypes. Gene expression data can also be combined with cell-based assays to identify cellular phenotypes associated with gene expression changes. Coculture systems are manipulable systems that can yield important insights about cell-cell interactions and the cellular phenotypes that occur as tumor and stroma co-evolve. PMID:22203785

  14. Impact of Stroma on the Growth, Microcirculation, and Metabolism of Experimental Prostate Tumors

    PubMed Central

    Zechmann, Christian M; Woenne, Eva C; Brix, Gunnar; Radzwill, Nicole; Ilg, Martin; Bachert, Peter; Peschke, Peter; Kirsch, Stefan; Kauczor, Hans-Ulrich; Delorme, Stefan; Semmler, Wolfhard; Kiessling, Fabian

    2007-01-01

    Abstract In prostate cancers (PCa), the formation of malignant stroma may substantially influence tumor phenotype and aggressiveness. Thus, the impact of the orthotopic and subcutaneous implantations of hormone-sensitive (H), hormone-insensitive (HI), and anaplastic (AT1) Dunning PCa in rats on growth, microcirculation, and metabolism was investigated. For this purpose, dynamic contrast-enhanced magnetic resonance imaging and 1H magnetic resonance spectroscopy ([1H]MRS) were applied in combination with histology. Consistent observations revealed that orthotopic H tumors grew significantly slower compared to subcutaneous ones, whereas the growth of HI and AT1 tumors was comparable at both locations. Histologic analysis indicated that glandular differentiation and a close interaction of tumor cells and smooth muscle cells (SMC) were associated with slow tumor growth. Furthermore, there was a significantly lower SMC density in subcutaneous H tumors than in orthotopic H tumors. Perfusion was observed to be significantly lower in orthotopic H tumors than in subcutaneous H tumors. Regional blood volume and permeability-surface area product showed no significant differences between tumor models and their implantation sites. Differences in growth between subcutaneous and orthotopic H tumors can be attributed to tumor-stroma interaction and perfusion. Here, SMC, may stabilize glandular structures and contribute to the maintenance of differentiated phenotype. PMID:17325744

  15. Type IV collagen is a tumour stroma-derived biomarker for pancreas cancer

    PubMed Central

    Öhlund, D; Lundin, C; Ardnor, B; Öman, M; Naredi, P; Sund, M

    2009-01-01

    Background: Pancreas cancer is a dreaded disease with high mortality, despite progress in surgical and oncological treatments in recent years. The field is hampered by a lack of good prognostic and predictive tumour biomarkers to be used during follow-up of patients. Methods: The circulating level of type IV collagen was measured by ELISA in pancreas cancer patients and controls. The expression pattern of type IV collagen in normal pancreas, pancreas cancer tissue and in pancreas cancer cell lines was studied by immunofluorescence and Western blot techniques. Results: Patients with pancreas cancer have significantly increased circulating levels of type IV collagen. In pancreas cancer tissue high levels of type IV collagen expression was found in close proximity to cancer cells in the tumour stroma. Furthermore, pancreas cancer cells were found to produce and secrete type IV collagen in vitro, which in part can explain the high type IV collagen expression observed in pancreas cancer tissue, and the increased circulating levels in pancreas cancer patients. Of clinical importance, our results show that the circulating level of type IV collagen after surgery is strongly related to prognosis in patients treated for pancreas cancer by pancreatico-duodenectomy with curative intent. Persisting high levels of circulating type IV collagen after surgery indicates a quick relapse in disease and poor survival. Conclusion: Our results most importantly show that stroma related substances can be evaluated as potential cancer biomarkers, and thereby underline the importance of the tumour microenvironment also in this context. PMID:19491897

  16. Distinct subpopulations of FOXD1 stroma-derived cells regulate renal erythropoietin

    PubMed Central

    Liu, Qingdu; Binns, Thomas C.; Davidoff, Olena; Kapitsinou, Pinelopi P.; Pfaff, Andrew S.; Olauson, Hannes; Fogo, Agnes B.; Fong, Guo-Hua; Gross, Kenneth W.

    2016-01-01

    Renal peritubular interstitial fibroblast-like cells are critical for adult erythropoiesis, as they are the main source of erythropoietin (EPO). Hypoxia-inducible factor 2 (HIF-2) controls EPO synthesis in the kidney and liver and is regulated by prolyl-4-hydroxylase domain (PHD) dioxygenases PHD1, PHD2, and PHD3, which function as cellular oxygen sensors. Renal interstitial cells with EPO-producing capacity are poorly characterized, and the role of the PHD/HIF-2 axis in renal EPO-producing cell (REPC) plasticity is unclear. Here we targeted the PHD/HIF-2/EPO axis in FOXD1 stroma-derived renal interstitial cells and examined the role of individual PHDs in REPC pool size regulation and renal EPO output. Renal interstitial cells with EPO-producing capacity were entirely derived from FOXD1-expressing stroma, and Phd2 inactivation alone induced renal Epo in a limited number of renal interstitial cells. EPO induction was submaximal, as hypoxia or pharmacologic PHD inhibition further increased the REPC fraction among Phd2–/– renal interstitial cells. Moreover, Phd1 and Phd3 were differentially expressed in renal interstitium, and heterozygous deficiency for Phd1 and Phd3 increased REPC numbers in Phd2–/– mice. We propose that FOXD1 lineage renal interstitial cells consist of distinct subpopulations that differ in their responsiveness to Phd2 inactivation and thus regulation of HIF-2 activity and EPO production under hypoxia or conditions of pharmacologic or genetic PHD inactivation. PMID:27088801

  17. The identification of trans-associations between prostate cancer GWAS SNPs and RNA expression differences in tumor-adjacent stroma

    PubMed Central

    Chen, Xin; McClelland, Michael; Jia, Zhenyu; Rahmatpanah, Farah B.; Sawyers, Anne; Trent, Jeffrey; Duggan, David; Mercola, Dan

    2015-01-01

    Here we tested the hypothesis that SNPs associated with prostate cancer risk, might differentially affect RNA expression in prostate cancer stroma. The most significant 35 SNP loci were selected from Genome Wide Association (GWA) studies of ~40,000 patients. We also selected 4030 transcripts previously associated with prostate cancer diagnosis and prognosis. eQTL analysis was carried out by a modified BAYES method to analyze the associations between the risk variants and expressed transcripts jointly in a single model. We observed 47 significant associations between eight risk variants and the expression patterns of 46 genes. This is the first study to identify associations between multiple SNPs and multiple in trans gene expression differences in cancer stroma. Potentially, a combination of SNPs and associated expression differences in prostate stroma may increase the power of risk assessment for individuals, and for cancer progression. PMID:25638161

  18. Giant cell tumor of the pancreas arising in the ovarian-like stroma of a mucinous cystadenocarcinoma.

    PubMed

    Bergman, S; Medeiros, L J; Radr, T; Mangham, D C; Lewandrowski, K B

    1995-08-01

    We describe a malignant mucinous cystic neoplasm of the pancreas with ovarian-like stroma within which an osteoclast-like giant cell rich tumor arose. This rare tumor had a unique immunohistochemical profile with the giant cells staining for vimentin, leukocyte common antigen, and the monocyte/macrophage marker CD68, whereas the mucinous epithelium stained for epithelial membrane antigen and cytokeratin. The immunohistochemical findings are consistent with two lines of differentiation, one epithelial and the other suggesting mesenchymal differentiation of the giant cell tumor with an immunophenotype similar to giant cell tumor of bone. The coexistence of these two rare tumors suggests that they are histogenetically related. The findings of a giant cell tumor arising in the ovarian stroma indicates that the stroma of mucinous tumors is not always an innocuous component of the tumor. PMID:7594774

  19. Systems Analysis of a Mouse Xenograft Model Reveals Annexin A1 as a Regulator of Gene Expression in Tumor Stroma

    PubMed Central

    Yi, Ming

    2012-01-01

    Annexin A1 is a multi functional molecule which is involved in inflammation, innate and adaptive immune systems, tumor progression and metastasis. We have previously showed the impaired tumor growth, metastasis, angiogenesis and wound healing in annexin A1 knockout mice. While tumor is a piece of heterogeneous mass including not only malignant tumor cells but also the stroma, the importance of the tumor stroma for tumor progression and metastasis is becoming increasingly clear. The tumor stroma is comprised by various components including extracellular matrix and non-malignant cells in the tumor, such as endothelial cells, fibroblasts, immune cells, inflammatory cells. Based on our previous finding of pro-angiogenic functions for annexin A1 in vascular endothelial cell sprouting, wound healing, tumor growth and metastasis, and the previously known properties for annexin A1 in immune cells and inflammation, this study hypothesized that annexin A1 is a key functional player in tumor development, linking the various components in tumor stroma by its actions in endothelial cells and immune cells. Using systems analysis programs commercially available, this paper further compared the gene expression between tumors from annexin A1 wild type mice and annexin A1 knockout mice and found a list of genes that significantly changed in the tumor stroma that lacked annexin A1. This revealed annexin A1 to be an effective regulator in tumor stroma and suggested a mechanism that annexin A1 affects tumor development and metastasis through interaction with the various components in the microenvironment surrounding the tumor cells. PMID:23077482

  20. NR4A3 rearrangement reliably distinguishes between the clinicopathologically overlapping entities myoepithelial carcinoma of soft tissue and cellular extraskeletal myxoid chondrosarcoma.

    PubMed

    Flucke, Uta; Tops, Bastiaan B J; Verdijk, Marian A J; van Cleef, Patricia J H; van Zwam, Peter H; Slootweg, Pieter J; Bovée, Judith V M G; Riedl, Robert G; Creytens, David H; Suurmeijer, Albert J H; Mentzel, Thomas

    2012-06-01

    Myoepithelial carcinoma of soft tissue (MEC) and cellular extraskeletal myxoid chondrosarcoma (cEMC) share striking similarities. In this paper, we compare ten MECs with five cEMCs. MEC patients had an equal gender distribution. The age range was 15-76 years (mean, 42 years). Tumours were located on extremities, pelvic girdle, vulva and neck. Follow-up, available for nine patients, ranged from 4 to 85 months (mean, 35 months). Five patients were alive without evidence of disease, two were alive with disease and two died 8 months after the initial diagnosis. cEMCs were from three males and two females with an age range of 37-82 years (mean, 57 years); they presented in extremities, shoulder and paravertebral/cervical. Follow-up, available for four patients, ranged from 6 to 220 months (mean, 61 months). All patients were alive, two with recurrences and/or metastases and two without evidence of disease. Morphologically, the distinction between these two entities was difficult since all cases exhibited features typically seen in myoepithelial tumours. Immunohistochemically, MECs expressed pan-keratin (80 %), epithelial membrane antigen (EMA; 57 %), S100 (50 %), alpha-smooth muscle actin (ASMA; 75 %), calponin (67 %) and p63 (25 %). S100 and EMA were expressed in 40 % of cEMC cases respectively with additional immunoreactivity for p63, ASMA and glial fibrillary acidic protein in one case. Pan-keratin was negative in all neoplasms. NR4A3 rearrangement was present in four of four cEMCs and in none of the MECs. In contrast, three of nine (33 %) MECs and four of five (80 %) cEMCs showed an EWSR1 rearrangement. In summary, MECs and cEMCs share clinical, morphological, immunohistochemical and genetic characteristics. The pathognomic rearrangement of NR4A3 is a useful diagnostic feature in identifying cEMCs. PMID:22569967

  1. Virtual microdissection identifies distinct tumor- and stroma-specific subtypes of pancreatic ductal adenocarcinoma

    PubMed Central

    Moffitt, Richard A.; Marayati, Raoud; Flate, Elizabeth L.; Volmar, Keith E.; Loeza, S. Gabriela Herrera; Hoadley, Katherine A.; Rashid, Naim U.; Williams, Lindsay A.; Eaton, Samuel C.; Chung, Alexander H.; Smyla, Jadwiga K.; Anderson, Judy M.; Kim, Hong Jin; Bentrem, David J.; Talamonti, Mark S.; Iacobuzio-Donahue, Christine A.; Hollingsworth, Michael A.; Yeh, Jen Jen

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) remains a lethal disease with a 5-year survival of 4%. A key hallmark of PDAC is extensive stromal involvement, which makes capturing precise tumor-specific molecular information difficult. Here, we have overcome this problem by applying blind source separation to a diverse collection of PDAC gene expression microarray data, which includes primary, metastatic, and normal samples. By digitally separating tumor, stroma, and normal gene expression, we have identified and validated two tumor-specific subtypes including a “basal-like” subtype which has worse outcome, and is molecularly similar to basal tumors in bladder and breast cancer. Furthermore, we define “normal” and “activated” stromal subtypes which are independently prognostic. Our results provide new insight into the molecular composition of PDAC which may be used to tailor therapies or provide decision support in a clinical setting where the choice and timing of therapies is critical. PMID:26343385

  2. Thermal Transitions of Fibrillar Collagen Unveiled by Second-Harmonic Generation Microscopy of Corneal Stroma

    PubMed Central

    Matteini, Paolo; Cicchi, Riccardo; Ratto, Fulvio; Kapsokalyvas, Dimitrios; Rossi, Francesca; de Angelis, Marella; Pavone, Francesco S.; Pini, Roberto

    2012-01-01

    The thermal transitions of fibrillar collagen are investigated with second-harmonic generation polarization anisotropy microscopy. Second-harmonic generation images and polarization anisotropy profiles of corneal stroma heated in the 35–80°C range are analyzed by means of a theoretical model that is suitable to probe principal intramolecular and interfibrillar parameters of immediate physiological interest. Our results depict the tissue modification with temperature as the interplay of three destructuration stages at different hierarchical levels of collagen assembly including its tertiary structure and interfibrillar alignment, thus supporting and extending previous findings. This method holds the promise of a quantitative inspection of fundamental biophysical and biochemical processes and may find future applications in real-time and postsurgical functional imaging of collagen-rich tissues subjected to thermal treatments. PMID:22995490

  3. Sclerotic fibroma (storiform collagenoma)-like stroma in a fibroadenoma of axillary accessory breast tissue.

    PubMed

    Val-Bernal, José Fernando; González-Vela, María Carmen; De Grado, Mauricio; Garijo, María Francisca

    2012-08-01

    Accessory breast tissue is a subcutaneous remnant persisting after normal embryological development of the breast. It occurs most frequently in the axilla. Fibroadenomas in axillary breast tissue are rare. We report the case of a 29-year-old female patient who presented a fibroadenoma arising in the accessory breast tissue of the right axillary fossa. The neoplasm showed foci of sclerotic fibroma-like stroma. The patient had no signs of Cowden's syndrome. To the best of our knowledge, a lesion of this kind has not been previously reported. This stromal change suggests an uncommon involutional phase of the fibroadenoma with production of sclerotic and hypocellular collagen. The lesion should be differentiated from extraneural perineuroma, from the changes in fibroadenomas in Cowden's syndrome, from sclerosing lobular hyperplasia (fibroadenomatoid mastopathy) and from pseudoangiomatous stromal hyperplasia. PMID:22804110

  4. Separation and identification of the light harvesting proteins contained in grana and stroma thylakoid membrane fractions.

    PubMed

    Timperio, Anna Maria; Huber, Christian G; Zolla, Lello

    2004-06-18

    This paper presents the results of a study performed to develop a rapid and straightforward method to resolve and simultaneously identify the light-harvesting proteins of photosystem I (LHCI) and photosystem II (LHCII) present in the grana and stroma of the thylakoid membranes of higher plants. These hydrophobic proteins are embedded in the phospholipid membrane, and their extraction usually requires detergent and time consuming manipulations that may introduce artifacts. The method presented here makes use of digitonin, a detergent which causes rapid (within less than 3 min) cleavage of the thylakoid membrane into two subfractions: appressed (grana) and non-appressed (stroma) membranes, the former enriched in photosystem II and the latter containing mainly photosystem I. From these two fractions identification of the protein components was performed by separating them by reversed-phase high-performance liquid chromatography (RP-HPLC) and determining the intact molecular mass by electrospray ionization mass spectrometry (ESI-MS). By this strategy the ion suppression during ESI-MS that normally occurs in the presence of membrane phospholipids was avoided, since RP-HPLC removed most phospholipids from the analytes. Consequently, high quality mass spectra were extracted from the reconstructed ion chromatograms. The specific cleavage of thylakoid membranes by digitonin, as well as the rapid identification and quantification of the antenna composition of the two complexes facilitate future studies of the lateral migration of the chlorophyll-protein complexes along thylakoid membranes, which is well known to be induced by high intensity light or other environmental stresses. Such investigations could not be performed by sodium dodecylsulfate-polyacrylamide gel electrophoresis because of insufficient resolution of the proteins having molecular masses between 22,000 and 25,000. PMID:15248427

  5. A Native-Like Corneal Construct Using Donor Corneal Stroma for Tissue Engineering

    PubMed Central

    Lin, Jing; Yoon, Kyung-Chul; Zhang, Lili; Su, Zhitao; Lu, Rong; Ma, Ping; De Paiva, Cintia S.; Pflugfelder, Stephen C.; Li, De-Quan

    2012-01-01

    Tissue engineering holds great promise for corneal transplantation to treat blinding diseases. This study was to explore the use of natural corneal stroma as an optimal substrate to construct a native like corneal equivalent. Human corneal epithelium was cultivated from donor limbal explants on corneal stromal discs prepared by FDA approved Horizon Epikeratome system. The morphology, phenotype, regenerative capacity and transplantation potential were evaluated by hematoxylin eosin and immunofluorescent staining, a wound healing model, and the xeno-transplantation of the corneal constructs to nude mice. An optically transparent and stratified epithelium was rapidly generated on donor corneal stromal substrate and displayed native-like morphology and structure. The cells were polygonal in the basal layer and became flattened in superficial layers. The epithelium displayed a phenotype similar to human corneal epithelium in vivo. The differentiation markers, keratin 3, involucrin and connexin 43, were expressed in full or superficial layers. Interestingly, certain basal cells were immunopositive to antibodies against limbal stem/progenitor cell markers ABCG2 and p63, which are usually negative in corneal epithelium in vivo. It suggests that this bioengineered corneal epithelium shared some characteristics of human limbal epithelium in vivo. This engineered epithelium was able to regenerate in 4 days following from a 4mm-diameter wound created by a filter paper soaked with 1 N NaOH. This corneal construct survived well after xeno-transplantation to the back of a nude mouse. The transplanted epithelium remained multilayer and became thicker with a phenotype similar to human corneal epithelium. Our findings demonstrate that natural corneal stroma is an optimal substrate for tissue bioengineering, and a native-like corneal construct has been created with epithelium containing limbal stem cells. This construct may have great potential for clinical use in corneal

  6. Bidirectional Signaling of Mammary Epithelium and Stroma: Implications for Breast Cancer—Preventive Actions of Dietary Factors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mammary gland is composed of two major cellular compartments: a highly dynamic epithelium that undergoes cycles of proliferation, differentiation, and apoptosis in response to local and endocrine signals and the underlying stroma comprised of fibroblasts, endothelial cells, and adipocytes that c...

  7. Solar abundance of osmium

    PubMed Central

    Jacoby, George; Aller, Lawrence H.

    1976-01-01

    The abundance parameter, log gfA, where g is the statistical weight of the lower level, f is the oscillator strength, and A is the abundance (by numbers of atoms with respect to hydrogen), has been derived for three lines of osmium by a method of spectrum synthesis. An apparent discordance of the derived abundance with that found from the carbonaceous chondrites is probably to be attributed primarily to errors in the f-values, and blending with unknown contributors. PMID:16592314

  8. Mechanoregulatory tumor-stroma crosstalk in pancreatic cancer: Measurements of the effects of extracellular matrix mechanics on tumor growth behavior, and vice-versa, to inform therapeutics

    NASA Astrophysics Data System (ADS)

    Celli, Jonathan; Jones, Dustin; El-Hamidi, Hamid; Cramer, Gwendolyn; Hanna, William; Caide, Andrew; Jafari, Seyedehrojin

    The rheological properties of the extracellular matrix (ECM) have been shown to play key roles in regulating tumor growth behavior through mechanotranduction pathways. The role of the mechanical microenvironment may be particularly important tumors of the pancreas, noted for an abundance of rigid fibrotic stroma, implicated in therapeutic resistance. At the same time, cancer cells and their stromal partners (e.g. tumor associated fibroblasts) continually alter the mechanical microenvironment in response to extracellular physical and biochemical cues as part of a two-way mechanoregulatory dialog. Here, we describe experimental studies using 3D pancreatic cell cultures with customized mechanical properties, combined with optical microrheology to provide insight into tumor-driven matrix remodeling. Quantitative microscopy provides measurements of phenotypic changes accompanying systematic variation of ECM composition in collagen and laminin-rich basement membrane admixtures, while analysis of the trajectories of passive tracer particles embedded in ECM report dynamic changes in heterogeneity, microstructure and local shear modulus accompanying both ECM stiffening (fibrosis) processes, and ECM degradation near invading cells. We gratefully acknowledge funding from the National Cancer Institute, R00CA155045 (PI: Celli).

  9. SU-E-J-248: Contributions of Tumor and Stroma Phenotyping in Computer-Aided Diagnosis

    SciTech Connect

    Li, H; Lan, L; Sennett, C; Giger, M

    2015-06-15

    Purpose: To gain insight into the role of parenchyma stroma in the characterization of breast tumors by incorporating computerized mammographic parenchyma assessment into breast CADx in the task of distinguishing between malignant and benign lesions. Methods: This study was performed on 182 biopsy-proven breast mass lesions, including 76 benign and 106 malignant lesions. For each full-field digital mammogram (FFDM) case, our quantitative imaging analysis was performed on both the tumor and a region-of-interest (ROI) from the normal contralateral breast. The lesion characterization includes automatic lesion segmentation and feature extraction. Radiographic texture analysis (RTA) was applied on the normal ROIs to assess the mammographic parenchymal patterns of these contralateral normal breasts. Classification performance of both individual computer extracted features and the output from a Bayesian artificial neural network (BANN) were evaluated with a leave-one-lesion-out method using receiver operating characteristic (ROC) analysis with area under the curve (AUC) as the figure of merit. Results: Lesion characterization included computer-extracted phenotypes of spiculation, size, shape, and margin. For parenchymal pattern characterization, five texture features were selected, including power law beta, contrast, and edge gradient. Merging of these computer-selected features using BANN classifiers yielded AUC values of 0.79 (SE=0.03) and 0.67 (SE=0.04) in the task of distinguishing between malignant and benign lesions using only tumor phenotypes and texture features from the contralateral breasts, respectively. Incorporation of tumor phenotypes with parenchyma texture features into the BANN yielded improved classification performance with an AUC value of 0.83 (SE=0.03) in the task of differentiating malignant from benign lesions. Conclusion: Combining computerized tumor and parenchyma phenotyping was found to significantly improve breast cancer diagnostic accuracy

  10. Extraskeletal myxoid chondrosarcoma with non-EWSR1-NR4A3 variant fusions correlate with rhabdoid phenotype and high-grade morphology.

    PubMed

    Agaram, Narasimhan P; Zhang, Lei; Sung, Yun-Shao; Singer, Samuel; Antonescu, Cristina R

    2014-05-01

    Extraskeletal myxoid chondrosarcomas (EMC) are rare soft tissue sarcomas with distinctive histology and uncertain histogenesis, characterized by Ewing sarcoma breakpoint region 1-nuclear receptor subfamily 4, group A, member 3 (EWSR1-NR4A3) fusion in 75% of the cases. A smaller proportion of cases show NR4A3 fused to other gene partners including TATA binding protein-associated factor 15 (TAF15), transcription factor 12 (TCF12), and TRK-fused gene (TFG). The impact of various gene fusions on morphology and outcome has not been previously evaluated. We investigated 26 consecutive EMCs and correlated the genetic findings with morphology and clinical outcome. There were 5 females and 21 males (median age, 49.5 years). Mean size of the tumors was 11 cm. Fluorescence in situ hybridization analysis showed EWSR1-NR4A3 gene fusion in 16 cases (62%), TAF15-NR4A3 gene fusion in 7 cases (27%), and TCF12-NR4A3 gene fusion in 1 case (4%). Two cases showed only NR4A3 gene rearrangements. Morphologically, most EWSR1-rearranged tumors (10/16) showed low cellularity, minimal cytologic atypia, and low mitotic counts. In contrast, 80% of EMCs with variant (non-EWSR1) NR4A3 gene fusions (TAF15, TCF12) had high-grade morphology with increased cellularity, proliferation, and cytologic atypia, showing a plasmacytoid/rhabdoid morphology in half the cases. Follow-up showed that only 1 of 16 patients with EWSR1-rearranged tumors died of disease, in contrast to 3 (43%) of 7 TAF15-rearranged tumors. In conclusion, EMCs with variant NR4A3 gene fusions show a higher incidence of rhabdoid phenotype, high-grade morphology, and a more aggressive outcome compared with the EWSR1-NR4A3 positive tumors. Furthermore, fluorescence in situ hybridization assay for NR4A3, along with EWSR1, may be an additional ancillary test to confirm diagnosis of EMCs. PMID:24746215

  11. Immune Dysfunction Associated with Abnormal Bone Marrow-Derived Mesenchymal Stroma Cells in Senescence Accelerated Mice

    PubMed Central

    Li, Ming; Guo, Kequan; Adachi, Yasushi; Ikehara, Susumu

    2016-01-01

    Senescence accelerated mice (SAM) are a group of mice that show aging-related diseases, and SAM prone 10 (SAMP10) show spontaneous brain atrophy and defects in learning and memory. Our previous report showed that the thymus and the percentage of T lymphocytes are abnormal in the SAMP10, but it was unclear whether the bone marrow-derived mesenchymal stroma cells (BMMSCs) were abnormal, and whether they played an important role in regenerative medicine. We thus compared BMMSCs from SAMP10 and their control, SAM-resistant (SAMR1), in terms of cell cycle, oxidative stress, and the expression of PI3K and mitogen-activated protein kinase (MAPK). Our cell cycle analysis showed that cell cycle arrest occurred in the G0/G1 phase in the SAMP10. We also found increased reactive oxygen stress and decreased PI3K and MAPK on the BMMSCs. These results suggested the BMMSCs were abnormal in SAMP10, and that this might be related to the immune system dysfunction in these mice. PMID:26840301

  12. Therapeutic applications of mesenchymal stroma cells in pediatric diseases: current aspects and future perspectives.

    PubMed

    Habib, Hamid S; Halawa, Taher F; Atta, Hazem M

    2011-11-01

    Mesenchymal stem cells or stroma cells (MSCs) were recently proven to play various therapeutic roles when used in clinical trials to control various inflammatory, neoplastic and immunologic diseases in children. Clinical trials show some promising results, particularly in diseases where conventional therapy is still ineffective. However, experimental studies sometimes show conflicting results. This review aims to assess the current therapeutic role of MSCs in the control of several pediatric diseases and elaborate on their future applications by reviewing published studies. A review of published studies on this subject based on Pubmed and Medical Subject Heading databases, with search for all relevant articles focusing on results of clinical trials to evaluate the clinical applications of MSCs. The review includes documentation of positive as well as negative applications of MSCs focused on pediatric diseases. MSCs have important immunosuppressive and antifibrotic effects that need to be employed to help patients with diseases for which no conventional management has proven to be effective. They may be also be used as an adjuvant to conventional therapeutic modalities to consolidate recovery. This review sheds light on the significance of the use of MSCs for the treatment of various pediatric diseases and focuses on promising applications. Most of the reported studies agree about the favorable use of MSCs in various diseases; however, more clinical trials, involving larger numbers of patients, need to be conducted in order to refine the outcome of the therapeutic methods and establish standardized protocols. PMID:22037754

  13. Hyalinizing Spitz nevus: spindle and epithelioid cell nevus with paucicellular collagenous stroma.

    PubMed

    Liu, Jing; Cohen, Philip R; Farhood, Anwar

    2004-01-01

    Hyalinizing spindle and epithelioid cell nevus (Spitz nevus) is an uncommon melanocytic lesion. The histologic features of this benign tumor can mimic those of certain benign (dermatofibroma and desmoplastic cellular blue nevus) and malignant (metastatic carcinoma and malignant melanoma) neoplasms. We report a woman with a hyalinizing Spitz nevus and review the clinical characteristics, histologic features, and differential diagnosis of this lesion. The lesion presented as an asymptomatic red firm nodule on her abdomen. Microscopic examination showed a symmetric lesion in the dermis. The neoplastic cells were large and epithelioid-shaped or plump and spindle-shaped. They were present as isolated individual cells, single cells in a linear pattern, small nests, and fascicles in a paucicellular hyalinized stroma. Neoplastic cells with prominent eosinophilic nucleoli were evenly exhibited from the superficial to deep lesion. Diffuse expression of S-100 protein and absence of staining with antibodies to cytokeratin and HMB-45 were observed. The features were diagnostic of a hyalinizing Spitz nevus. Hyalinizing Spitz nevus is a benign lesion whose histologic features may mimic dermatofibroma, desmoplastic cellular blue nevus, metastatic carcinoma, and malignant melanoma. Immunohistochemical studies are helpful to differentiate these lesions. PMID:14746435

  14. Resolving Cancer-Stroma Interfacial Signaling and Interventions with Micropatterned Tumor-Stromal Assays

    PubMed Central

    Shen, Keyue; Luk, Samantha; Hicks, Daniel F; Elman, Jessica S; Bohr, Stefan; Iwamoto, Yoshiko; Murray, Ryan; Pena, Kristen; Wang, Fangjing; Seker, Erkin; Weissleder, Ralph; Yarmush, Martin L; Toner, Mehmet; Sgroi, Dennis; Parekkadan, Biju

    2014-01-01

    Tumor-stromal interactions are a determining factor in cancer progression. In vivo, the interaction interface is associated with spatially-resolved distributions of cancer and stromal phenotypes. Here, we establish a micropatterned tumor-stromal assay (μTSA) with laser capture microdissection to control the location of co-cultured cells and analyze bulk and interfacial tumor-stromal signaling in driving cancer progression. μTSA reveals a spatial distribution of phenotypes in concordance with human estrogen receptor-positive (ER+) breast cancer samples, and heterogeneous drug activity relative to the tumor-stroma interface. Specifically, an unknown mechanism of reversine is shown in targeting tumor-stromal interfacial interactions using ER+ MCF-7 breast cancer and bone marrow-derived stromal cells. Reversine suppresses MCF-7 tumor growth and bone metastasis in vivo by reducing tumor stromalization including collagen deposition and recruitment of activated stromal cells. This study advocates μTSA as a platform for studying tumor microenvironmental interactions and cancer field effects with applications in drug discovery and development. PMID:25489927

  15. Clinicopathological implications of vascular endothelial growth factor 165b expression in oral squamous cell carcinoma stroma.

    PubMed

    Nagasaki, Masahiro; Kondo, Seiji; Mukudai, Yoshiki; Kamatani, Takaaki; Akizuki, Ayako; Yaso, Atsushi; Shimane, Toshikazu; Shirota, Tatsuo

    2016-07-01

    Vascular endothelial growth factor (VEGF) is one of the most important angiogenic factors. VEGF165b was recently isolated as the anti-angiogenic VEGF splice variant. In the present study, we examined the association between VEGF165b expression and clinicopathological characteristics in order to determine how VEGF165b produced from oral squamous cell carcinoma (OSCC) affects the stromal cell biological activity. We examined the relationships between the expressions of both VEGF isoforms in normal human dermal fibroblasts (NHDFs) and OSCC cell lines (HSC2, 3, 4 and SAS). Our analyses indicated that both the mRNA and protein expression levels of VEGF165b in the HSC2 and SAS cells were higher than those in the NHDFs. VEGF165b did not promote cell growth or invasive capabilities, but it induced the cell adhesive capabilities to ECM. Although strong expression of the VEGF165 isoforms in tumor cells of OSCC tissues was observed, there was no significant difference in the VEGF165b expression level among the various degrees of malignancy. OSCC cells secrete VEGF165b into the stroma, and this factor may contribute to the process of anti-angiogenesis by inhibiting gelatinase-expressing cells and activating cell adhesive capabilities to ECM, such as that of fibroblasts surrounding tumor cells. PMID:27221145

  16. Scatter factor influences the formation of prostate epithelial cell colonies on bone marrow stroma in vitro.

    PubMed

    Lang, S H; Clarke, N W; George, N J; Testa, N G

    1999-06-01

    Prostate cancer metastases form selectively in the bone marrow. Previously we demonstrated motility was important for the formation of primary prostatic epithelial cell colonies in bone marrow stroma (BMS) co-culture. In this study we looked at the influence of motility factors on the colony formation of epithelial cells derived from benign (bPEC) or malignant (mPEC) prostate tissue. After 7 days co-culture we found that anti-scatter factor consistently inhibited prostate epithelial cell colony formation on BMS (7/7 mPEC and 4/7 bPEC samples showed significant inhibition). Antibodies against bFGF and 5T4 did not significantly affect colony formation. Addition of fibroblast conditioned media (derived from benign prostates) to co-cultures stimulated the colony formation of bPEC (170%) and mPEC (252%). This stimulation was eliminated by depletion of SF from the conditioned media. Immunohistochemical staining found c-Met expression in 5/6 bPEC cultures and 7/9 mPEC cultures. When grown in BMS co-culture expression of c-Met was positive in 3/6 bPEC and 2/7 mPEC samples. In conclusion, scatter factor influences the in vitro formation of prostate epithelial cell colonies on BMS co-culture. PMID:10545020

  17. Concurrent Gastric Adenocarcinoma of Fundic Gland Type and Carcinoma with Lymphoid Stroma: A Rare Case Report

    PubMed Central

    Cha, Hee Jeong; Kim, Kyungbin; Kim, Misung; Choi, Hyejeong; Kim, Young Min; Suh, Jae Hee

    2016-01-01

    Both gastric adenocarcinoma of fundic gland type (ADC-FG) and carcinoma with lymphoid stroma (lymphoepithelioma-like carcinoma, LELC) are relatively rare. Epstein-Barr virus (EBV) has been implicated in the pathogenesis of LELC. However, the pathogenesis of ADC-FG, as well as the role of EBV in the carcinogenesis of LELC, remain unclear and under debate. The current study presents a case of concurrent ADC-FG and LELC in the stomach in a 69-year-old man. Total gastrectomy was performed, and two separate masses were identified. Upon histological and immunohistochemical examination, the mass located in the lower body was determined to be LELC and the mass in the upper body was diagnosed as ADC-FG. The lesions were characterized by different mucin phenotypes and EBV in situ results. In the lower-body mass, EBV in situ hybridization expression was diffusely strongly positive, but MUC2, MUC5AC, MUC6, and CD10 were all negative. On the other hand, in the upper-body mass, the results were positive for MUC6 but negative for MUC2, MUC5AC, CD10, and EBV by in situ hybridization. The remaining gastric tissue was unremarkable, and perigastric lymph node metastases were absent. Seven months after the gastrectomy, a postoperative computed tomography scan revealed no recurrence or metastasis. PMID:27462199

  18. Efficient Transduction of Corneal Stroma by Adeno-Associated Viral Serotype Vectors for Implications in Gene Therapy of Corneal Diseases.

    PubMed

    Lu, Yi; Ai, Jianzhong; Gessler, Dominic; Su, Qin; Tran, Karen; Zheng, Qiang; Xu, Xun; Gao, Guangping

    2016-08-01

    Corneal disease is one of the leading causes of blindness worldwide. Gene therapy is an attractive therapeutic strategy for corneal diseases, but currently underdeveloped. Recombinant adeno-associated viral (rAAV) vectors have emerged as a highly promising gene therapy platform. This study aims to identify rAAV vectors that can efficiently transduce corneal stroma for potential applications in studying pathophysiology of corneal diseases and therapeutic development. We characterized 14 rAAV serotypes expressing enhanced green fluorescent protein (EGFP), for cell specificity and transduction efficiency after either intrastromal injection or topical administration in mouse corneas in vivo. Our results show that intrastromal injections of rAAVrh.8, rAAVrh.10, rAAVrh.39, and rAAVrh.43 efficiently transduce mouse corneal stroma in vivo, and that topical administrations of rAAVrh.10 and rAAVrh.39 subsequent to epithelial scraping generate detectable transgene expression. In vivo imaging analysis revealed that transgene expression became detectable by 1 week postadministration, peaked at 2 weeks, and lasted for the duration of the study (i.e., 4 weeks). Both rAAVrh.10 and rAAVrh.39 transduced more than 50% of keratocytes, the major cell type in the corneal stroma, by intrastromal injection and 30% by topical administration. Histopathology indicated that rAAV transduction of cornea caused no morphological adverse effects. Overall, our findings suggest that some rAAV serotype vectors can efficiently transduce corneal stroma in vivo, constituting a potentially powerful and safe gene delivery platform for gene therapy of corneal diseases. PMID:27001051

  19. Amount of stroma is associated with mammographic density and stromal expression of oestrogen receptor in normal breast tissues.

    PubMed

    Gabrielson, Marike; Chiesa, Flaminia; Paulsson, Janna; Strell, Carina; Behmer, Catharina; Rönnow, Katarina; Czene, Kamila; Östman, Arne; Hall, Per

    2016-07-01

    Following female sex and age, mammographic density is considered one of the strongest risk factors for breast cancer. Despite the association between mammographic density and breast cancer risk, little is known about the underlying histology and biological basis of breast density. To better understand the mechanisms behind mammographic density we assessed morphology, proliferation and hormone receptor status in relation to mammographic density in breast tissues from healthy women. Tissues were obtained from 2012-2013 by ultrasound-guided core needle biopsy from 160 women as part of the Karma (Karolinska mammography project for risk prediction for breast cancer) project. Mammograms were collected through routine mammography screening and mammographic density was calculated using STRATUS. The histological composition, epithelial and stromal proliferation status and hormone receptor status were assessed through immunohistochemical staining. Higher mammographic density was significantly associated with a greater proportion of stromal and epithelial tissue and a lower proportion of adipose tissue. Epithelial expression levels of Ki-67, oestrogen receptor (ER) and progesterone receptor (PR) were not associated with mammographic density. Epithelial Ki-67 was associated with a greater proportion of epithelial tissue, and epithelial PR was associated with a greater proportion of stromal and a lower proportion of adipose tissue. Epithelial ER was not associated with any tissues. In contrast, expression of ER in the stroma was significantly associated with a greater proportion of stroma, and negatively associated with the amount of adipose tissue. High mammographic density is associated with higher amount of stroma and epithelium and less amount of fat, but is not associated with a change in epithelial proliferation or receptor status. Increased expressions of both epithelial PR and stromal ER are associated with a greater proportion of stroma, suggesting hormonal involvement

  20. Combined cytotoxic and anti-invasive properties of redox-active nanoparticles in tumor-stroma interactions.

    PubMed

    Alili, Lirija; Sack, Maren; Karakoti, Ajay S; Teuber, Sarah; Puschmann, Katharina; Hirst, Suzanne M; Reilly, Christopher M; Zanger, Klaus; Stahl, Wilhelm; Das, Soumen; Seal, Sudipta; Brenneisen, Peter

    2011-04-01

    Tumor-stroma interaction plays an important role in tumor progression. Myofibroblasts, pivotal for tumor progression, populate the microecosystem of reactive stroma. The formation of myofibroblasts is mediated by tumor derived transforming growth factor β1 (TGFβ1) which initiates a reactive oxygen species cell type dependent expression of alpha-smooth muscle actin, a biomarker for myofibroblastic cells. Myofibroblasts express and secrete proinvasive factors significantly increasing the invasive capacity of tumor cells via paracrine mechanisms. Although antioxidants prevent myofibroblast formation, the same antioxidants increase the aggressive behavior of the tumor cells. In this study, the question was addressed of whether redox-active polymer-coated cerium oxide nanoparticles (CNP, nanoceria) affect myofibroblast formation, cell toxicity, and tumor invasion. Herein, nanoceria downregulate both the expression of alpha-smooth muscle actin positive myofibroblastic cells and the invasion of tumor cells. Furthermore, concentrations of nanoceria being non-toxic for normal (stromal) cells show a cytotoxic effect on squamous tumor cells. The treatment with redox-active CNP may form the basis for protection of stromal cells from the dominating influence of tumor cells in tumor-stroma interaction, thus being a promising strategy for chemoprevention of tumor invasion. PMID:21269688

  1. Transcriptome analysis of individual stromal cell populations identifies stroma-tumor crosstalk in mouse lung cancer model.

    PubMed

    Choi, Hyejin; Sheng, Jianting; Gao, Dingcheng; Li, Fuhai; Durrans, Anna; Ryu, Seongho; Lee, Sharrell B; Narula, Navneet; Rafii, Shahin; Elemento, Olivier; Altorki, Nasser K; Wong, Stephen T C; Mittal, Vivek

    2015-02-24

    Emerging studies have begun to demonstrate that reprogrammed stromal cells play pivotal roles in tumor growth, metastasis, and resistance to therapy. However, the contribution of stromal cells to non-small-cell lung cancer (NSCLC) has remained underexplored. We used an orthotopic model of Kras-driven NSCLC to systematically dissect the contribution of specific hematopoietic stromal cells in lung cancer. RNA deep-sequencing analysis of individually sorted myeloid lineage and tumor epithelial cells revealed cell-type-specific differentially regulated genes, indicative of activated stroma. We developed a computational model for crosstalk signaling discovery based on ligand-receptor interactions and downstream signaling networks and identified known and novel tumor-stroma paracrine and tumor autocrine crosstalk-signaling pathways in NSCLC. We provide cellular and molecular insights into components of the lung cancer microenvironment that contribute to carcinogenesis. This study has the potential for development of therapeutic strategies that target tumor-stroma interactions and may complement conventional anti-cancer treatments. PMID:25704820

  2. OXYGEN ABUNDANCES IN CEPHEIDS

    SciTech Connect

    Luck, R. E.; Andrievsky, S. M.; Korotin, S. N.; Kovtyukh, V. V. E-mail: serkor@skyline.od.ua E-mail: scan@deneb1.odessa.ua

    2013-07-01

    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  3. JNK1 stress signaling is hyper-activated in high breast density and the tumor stroma

    PubMed Central

    Lisanti, Michael P; Tsirigos, Aristotelis; Pavlides, Stephanos; Reeves, Kimberley Jayne; Peiris-Pagès, Maria; Chadwick, Amy L; Sanchez-Alvarez, Rosa; Lamb, Rebecca; Howell, Anthony; Martinez-Outschoorn, Ubaldo E; Sotgia, Federica

    2014-01-01

    myofibroblasts and macrophages, to create and maintain a fibrotic and inflammatory microenvironment. Finally, comparisons between the HD fibroblast gene signature and breast cancer tumor stroma revealed that JNK1 stress signaling is the single most significant biological process that is shared between these 2 data sets (with P values between 5.40E-09 and 1.02E-14), and is specifically associated with tumor recurrence. These results implicate “stromal JNK1 signaling” in the pathogenesis of human breast cancers and the transition to malignancy. Augmented TGF-β signaling also emerged as a common feature linking high breast density with tumor stroma and breast cancer recurrence (P = 5.23E-05). Similarities between the HD fibroblast gene signature, wound healing, and the cancer-associated fibroblast phenotype were also noted. Thus, this unbiased informatics analysis of high breast density provides a novel framework for additional experimental exploration and new hypothesis-driven breast cancer research, with a focus on cancer prevention and personalized medicine. PMID:24434780

  4. EDC/NHS cross-linked collagen foams as scaffolds for artificial corneal stroma.

    PubMed

    Vrana, N E; Builles, N; Kocak, H; Gulay, P; Justin, V; Malbouyres, M; Ruggiero, F; Damour, O; Hasirci, V

    2007-01-01

    In this study, a highly porous collagen-based biodegradable scaffold was developed as an alternative to synthetic, non-degradable corneal implants. The developed method involved lyophilization and subsequent stabilization through N-ethyl-N'-[3-dimethylaminopropyl] carbodiimide/N-hydroxy succinimide (EDC/NHS) cross-linking to yield longer lasting, porous scaffolds with a thickness similar to that of native cornea (500 microm). For collagen-based scaffolds, cross-linking is essential; however, it has direct effects on physical characteristics crucial for optimum cell behavior. Hence, the effect of cross-linking was studied by examining the influence of cross-linking on pore size distribution, bulk porosity and average pore size. After seeding the foam with human corneal keratocytes, cell proliferation, cell penetration into the scaffold and ECM production within the scaffold were studied. After a month of culture microscopical and immunohistochemical examinations showed that the foam structure did not undergo any significant loss of integrity, and the human corneal keratocytes populated the scaffold with cells migrating both longitudinally and laterally, and secreted some of the main constituents of the corneal ECM, namely collagen types I, V and VI. The foams had a layer of lower porosity (skin layer) both at the top and the bottom. Foams had an optimal porosity (93.6%), average pore size (67.7 microm), and chemistry for cell attachment and proliferation. They also had a sufficiently rapid degradation rate (73.6+/-1.1% in 4 weeks) and could be produced at a thickness close to that of the natural corneal stroma. Cells were seeded at the top surface of the foams and their numbers there was higher than the rest, basically due to the presence of the skin layer. This is considered to be an advantage when epithelial cells need to be seeded for the construction of hemi or full thickness cornea. PMID:17988518

  5. Detecting thermal phase transitions in corneal stroma by fluorescence micro-imaging analysis

    NASA Astrophysics Data System (ADS)

    Matteini, P.; Rossi, F.; Ratto, F.; Bruno, I.; Nesi, P.; Pini, R.

    2008-02-01

    Thermal modifications induced in corneal stroma were investigated by the use of fluorescence microscopy. Freshly extracted porcine corneas were immersed for 5 minutes in a water bath at temperatures in the 35-90°C range and stored in formalin. The samples were then sliced in 200-μm-thick transversal sections and analyzed under a stereomicroscope to assess corneal shrinkage. Fluorescence images of the thermally treated corneal samples were acquired using a slow-scan cooled CCD camera, after staining the slices with Indocyanine Green (ICG) fluorescent dye which allowed to detect fluorescence signal from the whole tissue. All measurements were performed using an inverted epifluorescence microscope equipped with a mercury lamp. The thermally-induced modifications to the corneal specimens were evaluated by studying the grey level distribution in the fluorescence images. For each acquired image, Discrete Fourier Transform (DFT) and entropy analyses were performed. The spatial distribution of DFT absolute value indicated the spatial orientation of the lamellar planes, while entropy was used to study the image texture, correlated to the stromal structural transitions. As a result, it was possible to indicate a temperature threshold value (62°C) for high thermal damage, resulting in a disorganization of the lamellar planes and in full agreement with the measured temperature for corneal shrinkage onset. Analysis of the image entropy evidenced five strong modifications in stromal architecture at temperatures of ~45°C, 53°C, 57°C, 66°C, 75°C. The proposed procedure proved to be an effective micro-imaging method capable of detecting subtle changes in corneal tissue subjected to thermal treatment.

  6. Human Ovarian Cancer Stroma Contains Luteinized Theca Cells Harboring Tumor Suppressor Gene GT198 Mutations*

    PubMed Central

    Peng, Min; Zhang, Hao; Jaafar, Lahcen; Risinger, John I.; Huang, Shuang; Mivechi, Nahid F.; Ko, Lan

    2013-01-01

    Ovarian cancer is a highly lethal gynecological cancer, and its causes remain to be understood. Using a recently identified tumor suppressor gene, GT198 (PSMC3IP), as a unique marker, we searched for the identity of GT198 mutant cells in ovarian cancer. GT198 has germ line mutations in familial and early onset breast and ovarian cancers and recurrent somatic mutations in sporadic fallopian tube cancers. GT198 protein has been shown as a steroid hormone receptor coregulator and also as a crucial factor in DNA repair. In this study, using GT198 as a marker for microdissection, we find that ovarian tumor stromal cells harboring GT198 mutations are present in various types of ovarian cancer including high and low grade serous, endometrioid, mucinous, clear cell, and granulosa cell carcinomas and in precursor lesions such as inclusion cysts. The mutant stromal cells consist of a luteinized theca cell lineage at various differentiation stages including CD133+, CD44+, and CD34+ cells, although the vast majority of them are differentiated overexpressing steroidogenic enzyme CYP17, a theca cell-specific marker. In addition, wild type GT198 suppresses whereas mutant GT198 protein stimulates CYP17 expression. The chromatin-bound GT198 on the human CYP17 promoter is decreased by overexpressing mutant GT198 protein, implicating the loss of wild type suppression in mutant cells. Together, our results suggest that GT198 mutant luteinized theca cells overexpressing CYP17 are common in ovarian cancer stroma. Because first hit cancer gene mutations would specifically mark cancer-inducing cells, the identification of mutant luteinized theca cells may add crucial evidence in understanding the cause of human ovarian cancer. PMID:24097974

  7. Loss of caveolin-1 and gain of MCT4 expression in the tumor stroma

    PubMed Central

    Martins, Diana; Beça, Francisco F; Sousa, Bárbara; Baltazar, Fátima; Paredes, Joana; Schmitt, Fernando

    2013-01-01

    The progression from in situ to invasive breast carcinoma is still an event poorly understood. However, it has been suggested that interactions between the neoplastic cells and the tumor microenvironment may play an important role in this process. Thus, the determination of differential tumor-stromal metabolic interactions could be an important step in invasiveness. The expression of stromal Caveolin-1 (Cav-1) has already been implicated in the progression from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC). Additionally, stromal Cav-1 expression has been associated with the expression of stromal monocarboxylate transporter 4 (MCT4) in invasive breast cancer. However, the role of stromal MCT4 in invasiveness has never been explored, neither the association between Cav-1 and MCT4 in the transition from breast DCIS to IDC. Therefore, our aim was to investigate in a series of breast cancer samples including matched in situ and invasive components, if there was a relationship between stromal Cav-1 and MCT4 in the progression from in situ to invasive carcinoma. We found loss of stromal Cav-1 in the progression to IDC in 75% of the cases. In contrast, MCT4 stromal expression was acquired in 87% of the IDCs. Interestingly, a concomitant loss of Cav-1 and gain of MCT4 was observed in the stroma of 75% of the cases, when matched in situ and invasive carcinomas were compared. These results suggest that alterations in Cav-1 and MCT4 may thus mark a critical point in the progression from in situ to invasive breast cancer. PMID:23907124

  8. Porphyromonas gingivalis within Placental Villous Mesenchyme and Umbilical Cord Stroma Is Associated with Adverse Pregnancy Outcome

    PubMed Central

    Vanterpool, Sizzle F.; Been, Jasper V.; Houben, Michiel L.; Nikkels, Peter G. J.; De Krijger, Ronald R.; Zimmermann, Luc J. I.; Kramer, Boris W.; Progulske-Fox, Ann; Reyes, Leticia

    2016-01-01

    Intrauterine presence of Porphyromonas gingivalis (Pg), a common oral pathobiont, is implicated in preterm birth. Our aim was to determine if the location of Pg within placental and/or umbilical cord sections was associated with a specific delivery diagnosis at preterm delivery (histologic chorioamnionitis, chorioamnionitis with funisitis, preeclampsia, and preeclampsia with HELLP-syndrome, small for gestational age). The prevalence and location of Pg within archived placental and umbilical cord specimens from preterm (25 to 32 weeks gestation) and term control cohorts were evaluated by immunofluorescent histology. Detection of Pg was performed blinded to pregnancy characteristics. Multivariate analyses were performed to evaluate independent effects of gestational age, being small for gestational age, specific preterm delivery diagnosis, antenatal steroids, and delivery mode, on the odds of having Pg in the preterm tissue. Within the preterm cohort, 49 of 97 (51%) placentas and 40 of 97 (41%) umbilical cord specimens were positive for Pg. Pg within the placenta was significantly associated with shorter gestation lengths (OR 0.63 (95%CI: 0.48–0.85; p = 0.002) per week) and delivery via caesarean section (OR 4.02 (95%CI: 1.15–14.04; p = 0.03), but not with histological chorioamnionitis or preeclampsia. However, the presence of Pg in the umbilical cord was significantly associated with preeclampsia: OR 6.73 (95%CI: 1.31–36.67; p = 0.02). In the term cohort, 2 of 35 (6%) placentas and no umbilical cord term specimens were positive for Pg. The location of Pg within the placenta was different between preterm and term groups in that Pg within the villous mesenchyme was only detected in the preterm cohort, whereas Pg associated with syncytiotrophoblasts was found in both preterm and term placentas. Taken together, our results suggest that the presence of Pg within the villous stroma or umbilical cord may be an important determinant in Pg-associated adverse pregnancy

  9. Six stroma-based RNA markers diagnostic for prostate cancer in European-Americans validated at the RNA and protein levels in patients in China

    PubMed Central

    Zhu, Jianguo; Pan, Cong; Jiang, Jun; Deng, Mingsen; Gao, Hengjun; Men, Bozhao; McClelland, Michael; Mercola, Dan; Zhong, Wei-De; Jia, Zhenyu

    2015-01-01

    We previously analyzed human prostate tissue containing stroma near to tumor and from cancer-negative tissues of volunteers. Over 100 candidate gene expression differences were identified and used to develop a classifier that could detect nearby tumor with an accuracy of 97% (sensitivity = 98% and specificity = 88%) based on 364 independent test cases from primarily European American cases. These stroma-based gene signatures have the potential to identify cancer patients among those with negative biopsies. In this study, we used prostate tissues from Chinese cases to validate six of these markers (CAV1, COL4A2, HSPB1, ITGB3, MAP1A and MCAM). In validation by real-time PCR, four genes (COL4A2, HSPB1, ITGB3, and MAP1A) demonstrated significantly lower expression in tumor-adjacent stroma compared to normal stroma (p value ≤ 0.05). Next, we tested whether these expression differences could be extended to the protein level. In IHC assays, all six selected proteins showed lower expression in tumor-adjacent stroma compared to the normal stroma, of which COL4A2, HSPB1 and ITGB3 showed significant differences (p value ≤ 0.05). These results suggest that biomarkers for diagnosing prostate cancer based on tumor microenvironment may be applicable across multiple racial groups. PMID:26158290

  10. Six stroma-based RNA markers diagnostic for prostate cancer in European-Americans validated at the RNA and protein levels in patients in China.

    PubMed

    Zhu, Jianguo; Pan, Cong; Jiang, Jun; Deng, Mingsen; Gao, Hengjun; Men, Bozhao; McClelland, Michael; Mercola, Dan; Zhong, Wei-D; Jia, Zhenyu

    2015-06-30

    We previously analyzed human prostate tissue containing stroma near to tumor and from cancer-negative tissues of volunteers. Over 100 candidate gene expression differences were identified and used to develop a classifier that could detect nearby tumor with an accuracy of 97% (sensitivity = 98% and specificity = 88%) based on 364 independent test cases from primarily European American cases. These stroma-based gene signatures have the potential to identify cancer patients among those with negative biopsies. In this study, we used prostate tissues from Chinese cases to validate six of these markers (CAV1, COL4A2, HSPB1, ITGB3, MAP1A and MCAM). In validation by real-time PCR, four genes (COL4A2, HSPB1, ITGB3, and MAP1A) demonstrated significantly lower expression in tumor-adjacent stroma compared to normal stroma (p value ≤ 0.05). Next, we tested whether these expression differences could be extended to the protein level. In IHC assays, all six selected proteins showed lower expression in tumor-adjacent stroma compared to the normal stroma, of which COL4A2, HSPB1 and ITGB3 showed significant differences (p value ≤ 0.05). These results suggest that biomarkers for diagnosing prostate cancer based on tumor microenvironment may be applicable across multiple racial groups. PMID:26158290

  11. Solar abundance of platinum

    PubMed Central

    Burger, Harry; Aller, Lawrence H.

    1975-01-01

    Three lines of neutral platinum, located at λ 2997.98 Å, λ 3064.71 Å, and λ 3301.86 Å have been used to determine the solar platinum abundance by the method of spectral synthesis. On the scale, log A(H) = 12.00, the thus-derived solar platinum abundance is 1.75 ± 0.10, in fair accord with Cameron's value of log A(Pt) = 1.69 derived by Mason from carbonaceous chondrites and calculated on the assumption that log A(Si) = 7.55 in the sun. PMID:16592278

  12. Stellar Oxygen Abundances

    NASA Astrophysics Data System (ADS)

    King, Jeremy

    1994-04-01

    This dissertation addresses several issues concerning stellar oxygen abundances. The 7774 {\\AA} O I triplet equivalent widths of Abia & Rebolo [1989, AJ, 347, 186] for metal-poor dwarfs are found to be systematically too high. I also argue that current effective temperatures used in halo star abundance studies may be ~150 K too low. New color-Teff relations are derived for metal-poor stars. Using the revised Teff values and improved equivalent widths for the 7774A O I triplet, the mean [O/Fe] ratio for a handful of halo stars is found to be +0.52 with no dependence on Teff or [Fe/H]. Possible cosmological implications of the hotter Teff scale are discussed along with additional evidence supporting the need for a higher temperature scale for metal-poor stars. Our Teff scale leads to a Spite Li plateau value of N(Li)=2.28 +/- 0.09. A conservative minimal primordial value of N(Li)=2.35 is inferred. If errors in the observations and models are considered, consistency with standard models of Big Bang nucleosynthesis is still achieved with this larger Li abundance. The revised Teff scale raises the observed B/Be ratio of HD 140283 from 10 to 12, making its value more comfortably consistent with the production of the observed B and Be by ordinary spallation. Our Teff values are found to be in good agreement with values predicted from both the Victoria and Yale isochrone color-Teff relations. Thus, it appears likely that no changes in globular cluster ages would result. Next, we examine the location of the break in the [O/Fe] versus [Fe/H] plane in a quantitative fashion. Analysis of a relatively homogeneous data set does not favor any unique break point in the range -1.7 /= -3), in agreement with the new results for halo dwarfs. We find that the gap in the observed [O/H] distribution, noted by Wheeler et al

  13. Abundances of light elements.

    PubMed Central

    Pagel, B E

    1993-01-01

    Recent developments in the study of abundances of light elements and their relevance to cosmological nucleosynthesis are briefly reviewed. The simplest model, based on standard cosmology and particle physics and assuming homogeneous baryon density at the relevant times, continues to stand up well. PMID:11607388

  14. PDGFR signaling blockade in marrow stroma impairs lung cancer bone metastasis.

    PubMed

    Catena, Raúl; Luis-Ravelo, Diego; Antón, Iker; Zandueta, Carolina; Salazar-Colocho, Pablo; Larzábal, Leyre; Calvo, Alfonso; Lecanda, Fernando

    2011-01-01

    Bone microenvironment and cell-cell interactions are crucial for the initiation and development of metastasis. By means of a pharmacologic approach, using the multitargeted tyrosine kinase inhibitor sunitinib, we tested the relevance of the platelet-derived growth factor receptor (PDGFR) axis in the bone marrow (BM) stromal compartment for the initiation and development of lung cancer metastasis to bone. PDGFRβ was found to be the main tyrosine kinase target of sunitinib expressed in BM stromal ST-2 and MC3T3-E1 preosteoblastic cells. In contrast, no expression of sunitinib-targeted receptors was found in A549M1 and low levels in H460M5 lung cancer metastatic cells. Incubation of ST-2 and human BM endothelial cells with sunitinib led to potent cell growth inhibition and induction of apoptosis in a dose-dependent manner. Similarly, sunitinib induced a robust proapoptotic effect in vivo on BM stromal PDGFRβ(+) cells and produced extensive disruption of tissue architecture and vessel leakage in the BM cavity. Pretreatment of ST-2 cells with sunitinib also hindered heterotypic adhesion to lung cancer cell lines. These effects were correlated with changes in cell-cell and cell-matrix molecules in both stromal and tumor cells. Pretreatment of mice with sunitinib before intracardiac inoculation of A549M1 or H460M5 cells caused marked inhibition of tumor cells homing to bone, whereas no effect was found when tumor cells were pretreated before inoculation. Treatment with sunitinib dramatically increased overall survival and prevented tumor colonization but not bone lesions, whereas combination with zoledronic acid resulted in marked reduction of osteolytic lesions and osseous tumor burden. Thus, disruption of the PDGFR axis in the BM stroma alters heterotypic tumor-stromal and tumor-matrix interactions, thereby preventing efficient engagement required for bone homing and osseous colonization. These results support the notion that concomitant targeting of the tumor and

  15. THE TREATMENT-RESISTANT MESENCHYMAL SIGNATURE IN GLIOBLASTOMA DERIVES FROM TUMOR CELLS INDEPENDENT OF STROMA

    PubMed Central

    Sulman, Erik P.; Wang, Qianghu; Ezhilarasan, Ravesanker; Goodman, Lindsey D.; Gumen, Joy; Sun, Peng; Aldape, Ken; Alfred Yung, WK; Heffernan, Timothy; Draetta, Giulio F.; Lang, Frederick F.

    2014-01-01

    identified a total of 5 gene-expression clusters. GSCs in only one of these clusters showed enrichment for a unique TCGA class, mesenchymal. GSCs in other clusters were divided among multiple TCGA classes. CONCLUSIONS: Mesenchymal glioblastomas are derived from mesenchymal GSCs, suggesting that the tumor component is the largest contributor to the aggressive biology of this subtype. GSCs from other tumor subtypes correlate to multiple TCGA classes, suggesting that tumor stroma may contribute to the expression phenotype in those cases. Therapeutics targeting the microenvironment, such as anti-angiogenesis drugs, may have a greater role in non-mesenchymal tumors where the stromal contribution is more prominent. SECONDARY CATEGORY: Neuropathology & Tumor Biomarkers.

  16. SPARC-Independent Delivery of Nab-Paclitaxel without Depleting Tumor Stroma in Patient-Derived Pancreatic Cancer Xenografts.

    PubMed

    Kim, Harrison; Samuel, Sharon; Lopez-Casas, Pedro; Grizzle, William; Hidalgo, Manuel; Kovar, Joy; Oelschlager, Denise; Zinn, Kurt; Warram, Jason; Buchsbaum, Donald

    2016-04-01

    The study goal was to examine the relationship between nab-paclitaxel delivery and SPARC (secreted protein acidic and rich in cysteine) expression in pancreatic tumor xenografts and to determine the antistromal effect of nab-paclitaxel, which may affect tumor vascular perfusion. SPARC-positive and -negative mice bearing Panc02 tumor xenografts (n = 5-6/group) were injected with IRDye 800CW (IR800)-labeled nab-paclitaxel. After 24 hours, tumors were collected and stained with DL650-labeled anti-SPARC antibody, and the correlation between nab-paclitaxel and SPARC distributions was examined. Eight groups of mice bearing either Panc039 or Panc198 patient-derived xenografts (PDX; 4 groups/model, 5 animals/group) were untreated (served as control) or treated with gemcitabine (100 mg/kg body weight, i.p., twice per week), nab-paclitaxel (30 mg/kg body weight, i.v., for 5 consecutive days), and these agents in combination, respectively, for 3 weeks, and tumor volume and perfusion changes were assessed using T2-weighted MRI and dynamic contrast-enhanced (DCE) MRI, respectively. All tumors were collected and stained with Masson's Trichrome Stain, followed by a blinded comparative analysis of tumor stroma density. IR800-nab-paclitaxel was mainly distributed in tumor stromal tissue, but nab-paclitaxel and SPARC distributions were minimally correlated in either SPARC-positive or -negative animals. Nab-paclitaxel treatment neither decreased tumor stroma nor increased tumor vascular perfusion in either PDX model when compared with control groups. These data suggest that the specific tumor delivery of nab-paclitaxel is not directly related to SPARC expression, and nab-paclitaxel does not deplete tumor stroma in general. Mol Cancer Ther; 15(4); 680-8. ©2016 AACR. PMID:26832793

  17. Transforming growth factor beta2 inhibits adipocyte differentiation induced by skeletal unloading in rat bone marrow stroma.

    PubMed

    Ahdjoudj, Souhila; Lasmoles, Françoise; Holy, Xavier; Zerath, Erik; Marie, Pierre J

    2002-04-01

    Skeletal unloading induced by hindlimb suspension in rats reduces bone formation and induces osteopenia, but its effect on adipogenesis is unknown. We assessed the effects of unloading and transforming growth factor (TGF) beta2 on bone marrow stromal cell adipocyte differentiation in relation with osteoblast differentiation. Skeletal unloading rapidly (4-7 days) decreased osteoblast transcription factor Runx2, osteocalcin (OC), and type I collagen messenger RNA (mRNA) levels and reduced bone formation in the long bone metaphysis. Conversely, unloading increased expression of the adipocyte transcription factor peroxisome proliferator-activated receptor gamma2 (PPARgamma2) at 4 days and increased expression of the adipocyte differentiation genes lipoprotein lipase (LPL) and aP2 in the bone marrow stroma at 7 days. Consistently, unloading increased the number and volume of adipocytes in the bone marrow stroma. Continuous (0-7 days) and late (4-7 days) treatments with TGF-beta2 corrected the abnormal expression of Cbfa1/Runx2, OC, and type I collagen mRNAs and normalized bone formation in unloaded metaphyseal bone. Moreover, both TGF-beta2 treatments decreased PPARy2 and C/EBPalpha mRNA levels at 4 days and normalized aP2 and LPL expression and adipocyte number and volume at 7 days. These results show that skeletal unloading increases adipocyte differentiation concomitantly with inhibition of osteoblast differentiation. These abnormalities are prevented and reversed by TGF-beta2, suggesting a role for TGF-beta in the control of adipogenic differentiation in the bone marrow stroma. PMID:11918224

  18. Elevated expression of chemokine C-C ligand 2 in stroma is associated with recurrent basal-like breast cancers.

    PubMed

    Yao, Min; Yu, Elaine; Staggs, Vincent; Fan, Fang; Cheng, Nikki

    2016-08-01

    Despite advances in treatment, up to 30% of breast cancer patients experience disease recurrence accompanied by more aggressive disease and poorer prognosis. Treatment of breast cancer is complicated by the presence of multiple breast cancer subtypes, including: luminal, Her2 overexpressing, and aggressive basal-like breast cancers. Identifying new biomarkers specific to breast cancer subtypes could enhance the prediction of patient prognosis and contribute to improved treatment strategies. The microenvironment influences breast cancer progression through expression of growth factors, angiogenic factors and other soluble proteins. In particular, chemokine C-C ligand 2 (CCL2) regulates macrophage recruitment to primary tumors and signals to cancer cells to promote breast tumor progression. Here we employed a software-based approach to evaluate the prognostic significance of CCL2 protein expression in breast cancer subtypes in relation to its expression in the epithelium or stroma or in relation to fibroblast-specific protein 1 (Fsp1), a mesenchymal marker. Immunohistochemistry analysis of tissue microarrays revealed that CCL2 significantly correlated with Fsp1 expression in the stroma and tumor epithelium of invasive ductal carcinoma. In the overall cohort of invasive ductal carcinomas (n=427), CCL2 and Fsp1 expression in whole tissues, stroma and epithelium were inversely associated with cancer stage and tumor size. When factoring in molecular subtype, stromal CCL2 was observed to be most highly expressed in basal-like breast cancers. By Cox regression modeling, stromal CCL2, but not epithelial CCL2, expression was significantly associated with decreased recurrence-free survival. Furthermore, stromal CCL2 (HR=7.51 P=0.007) was associated with a greater hazard than cancer stage (HR=2.45, P=0.048) in multivariate analysis. These studies indicate that stromal CCL2 is associated with decreased recurrence-free survival in patients with basal-like breast cancer, with

  19. Stromal progesterone receptors mediate induction of Indian Hedgehog (IHH) in uterine epithelium and its downstream targets in uterine stroma.

    PubMed

    Simon, Liz; Spiewak, Kerry A; Ekman, Gail C; Kim, Jaeyeon; Lydon, John P; Bagchi, Milan K; Bagchi, Indrani C; DeMayo, Francesco J; Cooke, Paul S

    2009-08-01

    Uterine receptivity to embryo implantation depends on appropriate progesterone (P4) and estrogen stimulation. P4 rapidly stimulates production of the morphogen Indian hedgehog (IHH) in murine uterine epithelium as well as downstream molecules in the hedgehog pathway such as Patched homolog 1 (PTCH1) and nuclear receptor subfamily 2, group F, member 2 (NR2F2) in uterine stroma. Studies using IHH-null mice indicate that IHH is obligatory for the normal P4 response in the uterus. To determine whether IHH induction in uterine epithelium is mediated through P4 receptor (PR) in epithelium (E) and/or stroma (S), we produced tissue recombinants using uteri from neonatal PR knockout (ko) mice and wild-type (wt) mice containing PR in S and/or E or lacking PR altogether using a tissue recombinant methodology and assessed their response to P4. In tissue recombinants containing wt-S (wt-S + wt-E and wt-S + ko-E), P4 induced Ihh mRNA expression at 6 h that was 6-fold greater than in oil-treated controls (P < 0.05; n = 6) in both types of tissue recombinants despite the absence of epithelial PR in wt-S + ko-E grafts. Conversely, Ihh mRNA expression was unaffected by P4 in ko-S + ko-E and ko-S + wt-E grafts despite epithelial PR expression in the latter. Nr2f2 and Ptch1 mRNA expression was similar in that it was stimulated by P4 only in recombinants containing stromal PR. These results indicate that stromal PR is both necessary and sufficient for P4 stimulation of epithelial IHH as well as downstream events such as PTCH1 and NR2F2 increases in stroma. PMID:19372202

  20. Biochemical characterization of nuclear receptors for vitamin D{sub 3} and glucocorticoids in prostate stroma cell microenvironment

    SciTech Connect

    Hidalgo, Alejandro A.; Montecinos, Viviana P.; Paredes, Roberto; Godoy, Alejandro S.; McNerney, Eileen M.; Tovar, Heribelt; Pantoja, Diego; Johnson, Candace; Trump, Donald; Onate, Sergio A.

    2011-08-19

    Highlights: {yields} Fibroblasts from benign and carcinoma-associated stroma were biochemically characterized for VDR and GR function as transcription factors in prostate stroma cell microenvironment. {yields} Decreased SRC-1/CBP coactivators recruitment to VDR and GR may result in hormone resistance to 1,25D{sub 3} in stromal cell microenvironment prostate cancer. {yields} 1a,25-Dyhidroxyvitamin D{sub 3} (1,25D{sub 3}) and glucocorticoids, either alone or in combination, may not be an alternative for 'some' advanced prostate cancers that fails androgen therapies. -- Abstract: The disruption of stromal cell signals in prostate tissue microenvironment influences the development of prostate cancer to androgen independence. 1{alpha},25-Dihydroxyvitamin D{sub 3} (1,25D{sub 3}) and glucocorticoids, either alone or in combination, have been investigated as alternatives for the treatment of advanced prostate cancers that fails androgen therapies. The effects of glucocorticoids are mediated by the intracellular glucocorticoid receptor (GR). Similarly, the effect of 1,25D{sub 3} is mediated by the 1,25D{sub 3} nuclear receptor (VDR). In this study, fibroblasts from benign- (BAS) and carcinoma-associated stroma (CAS) were isolated from human prostates to characterize VDR and GR function as transcription factors in prostate stroma. The VDR-mediated transcriptional activity assessed using the CYP24-luciferase reporter was limited to 3-fold induction by 1,25D{sub 3} in 9 out of 13 CAS (70%), as compared to >10-fold induction in the BAS clinical sample pair. Expression of His-tagged VDR (Ad-his-VDR) failed to recover the low transcriptional activity of the luciferase reporter in 7 out of 9 CAS. Interestingly, expression of Ad-his-VDR successfully recovered receptor-mediated induction in 2 out of the 9 CAS analyzed, suggesting that changes in the receptor protein itself was responsible for decreased response and resistance to 1,25D{sub 3} action. Conversely, VDR

  1. Renal cell carcinoma with angioleiomyoma-like stroma: clinicopathological, immunohistochemical, and molecular features supporting classification as a distinct entity.

    PubMed

    Williamson, Sean R; Cheng, Liang; Eble, John N; True, Lawrence D; Gupta, Nilesh S; Wang, Mingsheng; Zhang, Shaobo; Grignon, David J

    2015-02-01

    Rare renal epithelial neoplasms have been recognized to have an angioleiomyoma or leiomyoma-like proliferation of stromal smooth muscle; however, the nature of these tumors and their relationships to other renal cell carcinomas are poorly understood. We analyzed 23 such tumors for their clinicopathological, immunohistochemical, and cytogenetic features using fluorescence in situ hybridization. Twelve showed a homogeneous combination of features and were reclassified as renal cell carcinoma with angioleiomyoma-like stroma. These were composed of neoplastic glandular structures lined by cells with mixed clear, pale, and eosinophilic cytoplasm forming occasional papillary tufts. The stroma resembled smooth muscle and often extended away from the epithelial component, entrapping perinephric fat or non-neoplastic renal elements. Immunohistochemistry showed the epithelium to have reactivity for: carbonic anhydrase IX, CD10, vimentin, cytokeratin 7, cytokeratin 34βE12, and PAX8 but not α-methylacyl-coA-racemase. The stroma labeled for smooth muscle (smooth muscle actin 3+, desmin 1+, caldesmon 3+) but not epithelial antigens. Neither component showed substantial reactivity for HMB45, melan-A, cathepsin K, or TFE3 protein. An interrupted, conspicuous layer of CD34-positive endothelial cells rimmed the epithelium, imparting a two-cell layer pattern resembling myoepithelial or basal cells. Chromosome 3p deletion and trisomy 7 and 17 were uniformly absent. Follow-up was available for three patients, none of whom experienced malignant behavior. Eleven tumors were excluded from this category and considered to be clear cell renal cell carcinoma with a reactive proliferation of smooth muscle (n=4) or tangential sectioning of the pseudocapsule (n=2), renal cell carcinoma unclassified (n=4), or clear cell papillary renal cell carcinoma (n=1). In summary, renal cell carcinoma with angioleiomyoma-like stroma is a distinct neoplasm with characteristic morphological

  2. Solar abundance of iridium

    PubMed Central

    Drake, Stephen; Aller, Lawrence H.

    1976-01-01

    By a method of spectrum synthesis, which yields log gfA, where g is the statistical weight of the lower level, f is the oscillator strength, and A is the abundance, an attempt is made to deduce the solar iridium abundance from one relatively unblended, but fairly weak IrI line, λ 3220.78 Å. If the Corliss-Bozman f-value for this line is adopted, we find log A(Ir) = 0.82 on the scale log A(H) = 12.00. The discordance with the value found from carbonaceous chondrites may arise from faulty f-values or from difficulties arising from line blending in this far ultraviolet domain of the solar spectrum. PMID:16578735

  3. The absence of aldehyde dehydrogenase 1 A1-positive cells in benign mammary stroma is associated with risk factors for breast cancer

    PubMed Central

    Isfoss, Björn Logi; Holmqvist, Bo; Jernström, Helena; Alm, Per; Olsson, Håkan

    2016-01-01

    In this study, aldehyde dehydrogenase 1 (ALDH1)-expressing cells in stroma of histologically normal breast tissue from premenopausal women were investigated in situ regarding cellular morphology, cell distribution, and relation to the additional stem cell markers, CD44 (+) and CD24 (−). These results were correlated with hormonal and genetic risk factors for breast cancer. Triple immunofluorescence labeling was performed on tissues from premenopausal women with a family history of breast cancer, and breast reduction specimens from premenopausal women with no family history of breast cancer were used as a control group. The majority of ALDH1-immunoreactive cells in stroma were spindle-shaped or polygonal, and such cells that were CD44− and CD24− were absent in the breast stroma of a significantly larger number of nulliparous than parous women. A less common morphological type of ALDH1-positive cells in stroma was round or oval in shape, and such cells that were CD44+ and CD24− were absent in a significant number of women with a family history of breast cancer. The CD44+/CD24− immunophenotype is consistent with stem cells, and the round/oval morphology suggests mesenchymal cells. This study demonstrates that there are two morphologically distinct types of ALDH1-positive cells in histologically benign mammary stroma, and the absence of these cells is correlated with clinical risk factors for breast cancer in premenopausal women. PMID:27313475

  4. The absence of aldehyde dehydrogenase 1 A1-positive cells in benign mammary stroma is associated with risk factors for breast cancer.

    PubMed

    Isfoss, Björn Logi; Holmqvist, Bo; Jernström, Helena; Alm, Per; Olsson, Håkan

    2016-01-01

    In this study, aldehyde dehydrogenase 1 (ALDH1)-expressing cells in stroma of histologically normal breast tissue from premenopausal women were investigated in situ regarding cellular morphology, cell distribution, and relation to the additional stem cell markers, CD44 (+) and CD24 (-). These results were correlated with hormonal and genetic risk factors for breast cancer. Triple immunofluorescence labeling was performed on tissues from premenopausal women with a family history of breast cancer, and breast reduction specimens from premenopausal women with no family history of breast cancer were used as a control group. The majority of ALDH1-immunoreactive cells in stroma were spindle-shaped or polygonal, and such cells that were CD44(-) and CD24(-) were absent in the breast stroma of a significantly larger number of nulliparous than parous women. A less common morphological type of ALDH1-positive cells in stroma was round or oval in shape, and such cells that were CD44(+) and CD24(-) were absent in a significant number of women with a family history of breast cancer. The CD44(+)/CD24(-) immunophenotype is consistent with stem cells, and the round/oval morphology suggests mesenchymal cells. This study demonstrates that there are two morphologically distinct types of ALDH1-positive cells in histologically benign mammary stroma, and the absence of these cells is correlated with clinical risk factors for breast cancer in premenopausal women. PMID:27313475

  5. c-Met identifies a population of matrix metalloproteinase 9-producing monocytes in peritumoural stroma of hepatocellular carcinoma.

    PubMed

    Zhao, Lan; Wu, Yan; Xie, Xu-Dong; Chu, Yi-Fan; Li, Jin-Qing; Zheng, Limin

    2015-11-01

    Macrophages (Mϕ) are prominent components of solid tumours and exhibit distinct phenotypes in different microenvironments. Previously, we found that tumours could alter the normal developmental process of Mϕ to trigger transient activation of monocytes in the peritumoural stroma of human hepatocellular carcinoma (HCC). In the present study, we showed that a fraction of monocytes in the peritumoural stroma, but not in HCC cancer nests, expressed surface c-Met molecules. Monocytes exposed to tumours strongly expressed c-Met proteins with kinetics similar to their activation status, and significant correlations were found between c-Met levels and HLA-DR expression on tumour-infiltrating monocytes. NF-κB-mediated autocrine TNF-α stimulated the expression of c-Met on activated monocytes, and by interacting with its ligand hepatocyte growth factor (HGF), c-Met increased the motility and matrix metalloproteinase (MMP) 9-producing capacity of tumour-associated monocytes. The intensity of c-Met expression on tumour-infiltrating monocytes was associated with high mortality and reduced survival of patients with HCC. Therefore, the expression of c-Met on activated monocytes/Mϕ may represent a novel mechanism by which a tumour actively and precisely regulates the distribution and functions of these cells to facilitate disease progression. PMID:26108200

  6. Modulation of Smad signaling by non-TGFβ components in myofibroblast generation during wound healing in corneal stroma.

    PubMed

    Saika, Shizuya; Yamanaka, Osamu; Okada, Yuka; Sumioka, Takayoshi

    2016-01-01

    Corneal scarring/fibrosis disturbs normal transparency and curvature of the tissue and thus impairs vision. The lesion is characterized by appearance of myofibroblasts, the key player of the fibrogenic reaction, and excess accumulation of extracellular matrix. Inflammatory/fibrogenic growth factors or cytokines expressed in inflammatory cells that infiltrate into injured tissues play a pivotal role in fibrotic tissue formation. In this article the pathogenesis of fibrosis/scarring in the corneal stroma is reviewed focusing on the roles of myofibroblast, the key player in corneal stromal wound healing and fibrosis, and cytoplasmic signals activated by the fibrogenic cytokine, transforming growth factor β (TGFβ). Although it is established that TGFβ/Smad signal is essential to the process of keratocyte-myofibroblast transformation in a healing corneal stroma post-injury. This article emphasizes the involvement of non-TGFβ molecular mechanisms in modulating Smad signal. We focus on the roles of matricellular proteins, i.e., osteopontin and tenascin C, and as cellular components, the roles of transient receptor potential (TRP) cation channel receptors are discussed. Our intent is to draw attention to the possibility of signal transduction cascade modulation (e.g., Smad signal and mitogen-activated protein kinases, by gene transfer and other related technology) as being beneficial in a clinical setting to reduce or even prevent corneal stromal tissue fibrosis/scarring and inflammation. PMID:26675402

  7. Thyroid hormones and tetrac: new regulators of tumour stroma formation via integrin αvβ3.

    PubMed

    Schmohl, Kathrin A; Müller, Andrea M; Wechselberger, Alexandra; Rühland, Svenja; Salb, Nicole; Schwenk, Nathalie; Heuer, Heike; Carlsen, Janette; Göke, Burkhard; Nelson, Peter J; Spitzweg, Christine

    2015-12-01

    To improve our understanding of non-genomic, integrin αvβ3-mediated thyroid hormone action in tumour stroma formation, we examined the effects of triiodo-l-thyronine (T3), l-thyroxine (T4) and integrin-specific inhibitor tetrac on differentiation, migration and invasion of mesenchymal stem cells (MSCs) that are an integral part of the tumour's fibrovascular network. Primary human bone marrow-derived MSCs were treated with T3 or T4 in the presence of hepatocellular carcinoma (HCC) cell-conditioned medium (CM), which resulted in stimulation of the expression of genes associated with cancer-associated fibroblast-like differentiation as determined by qPCR and ELISA. In addition, T3 and T4 increased migration of MSCs towards HCC cell-CM and invasion into the centre of three-dimensional HCC cell spheroids. All these effects were tetrac-dependent and therefore integrin αvβ3-mediated. In a subcutaneous HCC xenograft model, MSCs showed significantly increased recruitment and invasion into tumours of hyperthyroid mice compared to euthyroid and, in particular, hypothyroid mice, while treatment with tetrac almost completely eliminated MSC recruitment. These studies significantly improve our understanding of the anti-tumour activity of tetrac, as well as the mechanisms that regulate MSC differentiation and recruitment in the context of tumour stroma formation, as an important prerequisite for the utilisation of MSCs as gene delivery vehicles. PMID:26307023

  8. Identification of multipotent mesenchymal stromal cells in the reactive stroma of a prostate cancer xenograft by side population analysis

    SciTech Connect

    Santamaria-Martinez, Albert; Barquinero, Jordi; Barbosa-Desongles, Anna; Hurtado, Antoni; Pinos, Tomas; Seoane, Joan; Poupon, Marie-France; Morote, Joan; Reventos, Jaume; Munell, Francina

    2009-10-15

    Cancer stem cells are a distinct cellular population that is believed to be responsible for tumor initiation and maintenance. Recent data suggest that solid tumors also contain another type of stem cells, the mesenchymal stem cells or multipotent mesenchymal stromal cells (MSCs), which contribute to the formation of tumor-associated stroma. The Hoechst 33342 efflux assay has proved useful to identify a rare cellular fraction, named Side Population (SP), enriched in cells with stem-like properties. Using this assay, we identified SP cells in a prostate cancer xenograft containing human prostate cancer cells and mouse stromal cells. The SP isolation, subculture and sequential sorting allowed the generation of single-cell-derived clones of murine origin that were recognized as MSC by their morphology, plastic adherence, proliferative potential, adipogenic and osteogenic differentiation ability and immunophenotype (CD45{sup -}, CD81{sup +} and Sca-1{sup +}). We also demonstrated that SP clonal cells secrete transforming growth factor {beta}1 (TGF-{beta}1) and that their inhibition reduces proliferation and accelerates differentiation. These results reveal the existence of SP cells in the stroma of a cancer xenograft, and provide evidence supporting their MSC nature and the role of TGF-{beta}1 in maintaining their proliferation and undifferentiated status. Our data also reveal the usefulness of the SP assay to identify and isolate MSC cells from carcinomas.

  9. Targeted Disruption of Orchestration between Stroma and Tumor Cells in Pancreatic Cancer: Molecular Basis and Therapeutic Implications

    PubMed Central

    Kong, Xiangyu; Li, Lei; Li, Zhaoshen; Xie, Keping

    2012-01-01

    Pancreatic cancer is one of the most lethal malignancies, with a prominent desmoplastic reaction as the defining hallmark of the disease. The past several decades have seen dramatic progress in understanding of pancreatic cancer pathogenesis, including the identification of precursor lesions, sequential transformation from normal pancreas to invasive pancreatic cancer and corresponding signature genetic events, and the biological impact of those alterations on malignant behaviors. However, the current therapeutic strategies for epithelial tumor cells, which have exhibited potent antitumor activity in cell culture and animal models, have failed to have significant effects in the clinic. The desmoplastic stroma surrounding pancreatic cancer cells, which accounts for about 90% of a tumor’s mass, clearly is not a passive scaffold for cancer cells but an active contributor to carcinogenesis. Improved understanding of the dynamic interaction between cancer cells and their stroma will be important to designing new, effective therapeutic strategies for pancreatic cancer. This review focuses on the origination of stromal molecular and cellular components in pancreatic tumors, their biological effects on pancreatic cancer cells, and the orchestration between these two components. PMID:22749856

  10. Automatic Tumor-Stroma Separation in Fluorescence TMAs Enables the Quantitative High-Throughput Analysis of Multiple Cancer Biomarkers

    PubMed Central

    Lahrmann, Bernd; Halama, Niels; Sinn, Hans-Peter; Schirmacher, Peter; Jaeger, Dirk; Grabe, Niels

    2011-01-01

    The upcoming quantification and automation in biomarker based histological tumor evaluation will require computational methods capable of automatically identifying tumor areas and differentiating them from the stroma. As no single generally applicable tumor biomarker is available, pathology routinely uses morphological criteria as a spatial reference system. We here present and evaluate a method capable of performing the classification in immunofluorescence histological slides solely using a DAPI background stain. Due to the restriction to a single color channel this is inherently challenging. We formed cell graphs based on the topological distribution of the tissue cell nuclei and extracted the corresponding graph features. By using topological, morphological and intensity based features we could systematically quantify and compare the discrimination capability individual features contribute to the overall algorithm. We here show that when classifying fluorescence tissue slides in the DAPI channel, morphological and intensity based features clearly outpace topological ones which have been used exclusively in related previous approaches. We assembled the 15 best features to train a support vector machine based on Keratin stained tumor areas. On a test set of TMAs with 210 cores of triple negative breast cancers our classifier was able to distinguish between tumor and stroma tissue with a total overall accuracy of 88%. Our method yields first results on the discrimination capability of features groups which is essential for an automated tumor diagnostics. Also, it provides an objective spatial reference system for the multiplex analysis of biomarkers in fluorescence immunohistochemistry. PMID:22164226

  11. Overexpression of FGF9 in prostate epithelial cells augments reactive stroma formation and promotes prostate cancer progression.

    PubMed

    Huang, Yanqing; Jin, Chengliu; Hamana, Tomoaki; Liu, Junchen; Wang, Cong; An, Lei; McKeehan, Wallace L; Wang, Fen

    2015-01-01

    Bone metastasis is the major cause of morbidity and mortality of prostate cancer (PCa). Fibroblast growth factor 9 (FGF9) has been reported to promote PCa bone metastasis. However, the mechanism by which overexpression of FGF9 promotes PCa progression and metastasis is still unknown. Herein, we report that transgenic mice forced to express FGF9 in prostate epithelial cells (F9TG) developed high grade prostatic intraepithelial neoplasia (PIN) in an expression level- and time-dependent manner. Moreover, FGF9/TRAMP bigenic mice (F9TRAMP) grew advanced PCa earlier and had higher frequencies of metastasis than TRAMP littermates. We observed tumor microenvironmental changes including hypercellularity and hyperproliferation in the stromal compartment of F9TG and F9TRAMP mice. Expression of TGFβ1, a key signaling molecule overexpressed in reactive stroma, was increased in F9TG and F9TRAMP prostates. Both in vivo and in vitro data indicated that FGF9 promoted TGFβ1 expression via increasing cJun-mediated signaling. Moreover, in silico analyses showed that the expression level of FGF9 was positively associated with expression of TGFβ1 and its downstream signaling molecules in human prostate cancers. Collectively, our data demonstrated that overexpressing FGF9 in PCa cells augmented the formation of reactive stroma and promoted PCa initiation and progression. PMID:26157349

  12. Pyruvate Dehydrogenase and Pyruvate Dehydrogenase Kinase Expression in Non Small Cell Lung Cancer and Tumor-Associated Stroma1

    PubMed Central

    Koukourakis, Michael I; Giatromanolaki, Alexandra; Sivridis, Efthimios; Gatter, Kevin C; Harris, Adrian L; “Tumor and Angiogenesis Research Group”

    2005-01-01

    Abstract Pyruvate dehydrogenase (PDH) catalyzes the conversion of pyruvate to acetyl-coenzyme A, which enters into the Krebs cycle, providing adenosine triphosphate (ATP) to the cell. PDH activity is under the control of pyruvate dehydrogenase kinases (PDKs). Under hypoxic conditions, conversion of pyruvate to lactate occurs, a reaction catalyzed by lactate dehydrogenase 5 (LDH5). In cancer cells, however, pyruvate is transformed to lactate occurs, regardless of the presence of oxygen (aerobic glycolysis/Warburg effect). Although hypoxic intratumoral conditions account for HIF1α stabilization and induction of anaerobic metabolism, recent data suggest that high pyruvate concentrations also result in HIF1α stabilization independently of hypoxia. In the present immunohistochemical study, we provide evidence that the PDH/PDK pathway is repressed in 73% of non small cell lung carcinomas, which may be a key reason for HIF1α stabilization and “aerobic glycolysis.” However, about half of PDH-deficient carcinomas are not able to switch on the HIF pathway, and patients harboring these tumors have an excellent postoperative outcome. A small subgroup of clinically aggressive tumors maintains a coherent PDH and HIF/LDH5 expression. In contrast to cancer cells, fibroblasts in the tumor-supporting stroma exhibit an intense PDH but reduced PDK1 expression favoring maximum PDH activity. This means that stroma may use lactic acid produced by tumor cells, preventing the creation of an intolerable intratumoral acidic environment at the same time. PMID:15736311

  13. Expression of Autoactivated Stromelysin-1 in Mammary Glands of Transgenic Mice Leads to a Reactive Stroma During Early Development

    SciTech Connect

    Thomasset, N.; Lochter, A.; Sympson, C.J.; Lund, L.R.; Williams, D.R.; Behrendtsen, O.; Werb, Z.; Bissell, M.J.

    1998-04-24

    Extracellular matrix and extracellular matrix-degrading matrix metalloproteinases play a key role in interactions between the epithelium and the mesenchyme during mammary gland development and disease. In patients with breast cancer, the mammary mesenchyme undergoes a stromal reaction, the etiology of which is unknown. We previously showed that targeting of an autoactivating mutant of the matrix metalloproteinase stromelysin-1 to mammary epithelia of transgenic mice resulted in reduced mammary function during pregnancy and development of preneoplastic and neoplastic lesions. Here we examine the cascade of alterations before breast tumor formation in the mammary gland stroma once the expression of the stromelysin-1 transgene commences. Beginning in postpubertal virgin animals, low levels of transgene expression in mammary epithelia led to increased expression of endogenous stromelysin-1 in stromal fibroblasts and up-regulation of other matrix metalloproteinases, without basement membrane disruption. These changes were accompanied by the progressive development of a compensatory reactive stroma, characterized by increased collagen content and vascularization in glands from virgin mice. This remodeling of the gland affected epithelial-mesenchymal communication as indicated by inappropriate expression of tenascin-C starting by day 6 of pregnancy. This, together with increased transgene expression, led to basement membrane disruption starting by day 15 of pregnancy. We propose that the highly reactive stroma provides a prelude to breast epithelial tumors observed in these animals. Epithelial development depends on an exquisite series of inductive and instructive interactions between the differentiating epithelium and the mesenchymal (stromal) compartment. The epithelium, which consists of luminal and myoepithelial cells, is separated from the stroma by a basement membrane (BM), which plays a central role in mammary gland homeostasis and gene expression. In vivo, stromal

  14. Abundance of field galaxies

    NASA Astrophysics Data System (ADS)

    Klypin, Anatoly; Karachentsev, Igor; Makarov, Dmitry; Nasonova, Olga

    2015-12-01

    We present new measurements of the abundance of galaxies with a given circular velocity in the Local Volume: a region centred on the Milky Way Galaxy and extending to distance ˜10 Mpc. The sample of ˜750 mostly dwarf galaxies provides a unique opportunity to study the abundance and properties of galaxies down to absolute magnitudes MB ≈ -10 and virial masses M_vir= 109{ M_{⊙}}. We find that the standard Λ cold dark matter (ΛCDM) model gives remarkably accurate estimates for the velocity function of galaxies with circular velocities V ≳ 70 kms-1 and corresponding virial masses M_vir≳ 5× 10^{10}{ M_{⊙}}, but it badly fails by overpredicting ˜5 times the abundance of large dwarfs with velocities V = 30-40 kms-1. The warm dark matter (WDM) models cannot explain the data either, regardless of mass of WDM particle. Just as in previous observational studies, we find a shallow asymptotic slope dN/dlog V ∝ Vα, α ≈ -1 of the velocity function, which is inconsistent with the standard ΛCDM model that predicts the slope α = -3. Though reminiscent to the known overabundance of satellite problem, the overabundance of field galaxies is a much more difficult problem. For the standard ΛCDM model to survive, in the 10 Mpc radius of the Milky Way there should be 1000 not yet detected galaxies with virial mass M_vir≈ 10^{10}{ M_{⊙}}, extremely low surface brightness and no detectable H I gas. So far none of this type of galaxies have been discovered.

  15. Late embryogenesis abundant proteins

    PubMed Central

    Olvera-Carrillo, Yadira; Reyes, José Luis

    2011-01-01

    Late Embryogenesis Abundant (LEA) proteins accumulate at the onset of seed desiccation and in response to water deficit in vegetative plant tissues. The typical LEA proteins are highly hydrophilic and intrinsically unstructured. They have been classified in different families, each one showing distinctive conserved motifs. In this manuscript we present and discuss some of the recent findings regarding their role in plant adaptation to water deficit, as well as those concerning to their possible function, and how it can be related to their intrinsic structural flexibility. PMID:21447997

  16. Flare Plasma Iron Abundance

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.; Dan, Chau; Jain, Rajmal; Schwartz, Richard A.; Tolbert, Anne K.

    2008-01-01

    The equivalent width of the iron-line complex at 6.7 keV seen in flare X-ray spectra suggests that the iron abundance of the hottest plasma at temperatures >approx.10 MK may sometimes be significantly lower than the nominal coronal abundance of four times the photospheric value that is commonly assumed. This conclusion is based on X-ray spectral observations of several flares seen in common with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Solar X-ray Spectrometer (SOXS) on the second Indian geostationary satellite, GSAT-2. The implications of this will be discussed as it relates to the origin of the hot flare plasma - either plasma already in the corona that is directly heated during the flare energy release process or chromospheric plasma that is heated by flare-accelerated particles and driven up into the corona. Other possible explanations of lower-than-expected equivalent widths of the iron-line complex will also be discussed.

  17. Oxygen abundance and convection

    NASA Astrophysics Data System (ADS)

    Van't Veer, C.; Cayrel, R.

    The triplet IR lines of O I near 777 nm are computed with the Kurucz's code, modified to accept several convection models. The program has been run with the MLT algorithm, with l/H = 1.25 and 0.5, and with the Canuto-Mazzitelli and Canuto-Goldman-Mazzitelli approaches, on a metal-poor turnoff-star model atmosphere with Teff=6200 K, log g = 4.3, [Fe/H]= -1.5. The results show that the differences in equivalent widths for the 4 cases do not exceed 2 per cent (0.3 mA). The convection treatment is therefore not an issue for the oxygen abundance derived from the permitted lines.

  18. Origin of the impedance cardiogram investigated in the dog by exchange transfusion with a stroma-free haemoglobin solution.

    PubMed

    Visser, K R; Lamberts, R; Poelmann, A M; Zijlstra, W G

    1977-03-11

    In an anaesthetized dog an exchange transfusion was carried out with stroma-free haemoglobin solution. The total circulating blood volume was kept constant. The heart-syncronous changes in the thoracic electrical impedance (Zo) were measured before and after the exchange transfusion. Zo consists of a parallel connection of a tissue impedance (Zt) and a blood impedance (Zb). With the aid of this model for Zo the relative variations in Zb (delta Zb/Zb) were calculated from the relative variations in Zo (delta Zo/Zo). The marked decrease of delta Zb/Zb during the experiment can only be explained by the fact that apart from the heart-synchronous changes in vascular volume the impedance changes are also caused by flow dependent changes in the electrical conductivity of blood caused by variations in orientation of the erythrocytes. PMID:558590

  19. The role of stroma in the expansion of odontogenic cysts and adenomatoid odontogenic tumor: A polarized microscopy study

    PubMed Central

    Mahajan, Aarti M.; Mahajan, Mahendra C.; Ganvir, S. M.; Hazarey, V. K.

    2013-01-01

    Objectives: To compare the polarization colors of collagen fibers of odontogenic keratocyst (OKC), radicular cyst, dentigerous cyst, and adenomatoid odontogenic tumor (AOT) with reference to their biological behavior. Study Design: Twenty cases each of OKC, radicular cyst, dentigerous cyst, and AOT were stained with picrosirius red stain and studied under polarized light. Results: A predominance of green to greenish yellow thick fibers was noted in OKC and AOT as compared to dentigerous cyst and radicular cyst. There was no significant difference between the polarization colors of the thin fibers in all the three groups. Conclusion: The stroma of OKC and AOT consists of poorly packed or pathologic collagen and plays a role in its neoplastic behavior. PMID:24082724

  20. Distribution and significance of interstitial fibrosis and stroma-infiltrating B cells in tongue squamous cell carcinoma

    PubMed Central

    LAO, XIAO-MEI; LIANG, YU-JIE; SU, YU-XIONG; ZHANG, SI-EN; ZHOU, XI; LIAO, GUI-QING

    2016-01-01

    Inflammation and desmoplasia are frequently identified in the tumor microenvironment, and have been demonstrated to be effective modulators of malignant biological events. However, the mechanisms by which the inflammatory microenvironment and interstitial fibrosis interact with one another remain to be elucidated. The present study aimed to investigate the degree of inflammation and interstitial fibrosis in tongue squamous cell carcinoma (TSCC), and how this acts to affect the outcome of TSCC. Tissue samples from 93 cases of TSCC and paired tumor-adjacent non-neoplastic tongue epithelium, as well as 14 cases of epithelial dysplasia, were used. Interstitial collagen fibers were assessed using Masson's trichrome stain. Immunohistochemical identification of cancer-associated fibroblasts (CAFs) and stroma-infiltrating B cells was performed via detection of α-smooth muscle actin (SMA), vimentin, desmin and cluster of differentiation 19 (CD19). The clinicopathological significance and overall survival of the TSCC patients were statistically analyzed. Regularly distributed CAFs and CD19+ B cells were identified in the TSCC stroma, whereas no CAFs or CD19+ B cells were observed in epithelial dysplasia samples or paired tumor-adjacent non-neoplastic tongue epithelium samples. The distribution of interstitial collagen fibers and CAFs was closely associated with the tumor stage of the primary cancer, and high levels of CD19+ B cells together with low CAF infiltration were identified to be associated with favorable prognosis in TSCC. In conclusion, the inflammatory and interstitial fibrotic microenvironments coexist in TSCC, and each has specific effects on disease outcome, individually or perhaps collectively. However, it remains to be determined exactly how the microenvironments affect one another in TSCC. PMID:26998116

  1. Actinide abundances in ordinary chondrites

    NASA Technical Reports Server (NTRS)

    Hagee, B.; Bernatowicz, T. J.; Podosek, F. A.; Johnson, M. L.; Burnett, D. S.

    1990-01-01

    Measurements of actinide and light REE (LREE) abundances and of phosphate abundances in equilibrated ordinary chondrites were obtained and were used to define the Pu abundance in the solar system and to determine the degree of variation of actinide and LREE abundances. The results were also used to compare directly the Pu/U ratio with the earlier obtained ratio determined indirectly, as (Pu/Nd)x(Nd/U), assuming that Pu behaves chemically as a LREE. The data, combined with high-accuracy isotope-dilution data from the literature, show that the degree of gram-scale variability of the Th, U, and LREE abundances for equilibrated ordinary chondrites is a factor of 2-3 for absolute abundances and up to 50 percent for relative abundances. The observed variations are interpreted as reflecting the differences in the compositions and/or proportions of solar nebula components accreted to ordinary chondrite parent bodies.

  2. Capella: Structure and Abundances

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy S.

    1999-01-01

    This grant covers the analysis of EUVE spectra of the cool star binary system Capella. This project has also required the analysis of simultaneous Advanced Satellite for Cosmology and Astrophysics (ASCA) data. The ASCA spectrum of Capella could not be fit with standard models; by imposing models based on strong lines observed with EUVE, a problem wavelength region was identified. Correcting the problem required calculations of atomic collision strengths of higher principal quantum number than had ever been calculated. With these new models applied to the ASCA spectrum, better fits were obtained. Findings are that: (1) ASCA and EUVE spectra are both dominated by a region at 6 x 10(exp 6) K. (2) The high energy cut-off of the ASCA spectrum is consistent with emission from the highest ionization stages of EUVE, namely Fe XXIV. (3) EUVE requires a continuous emission measure distribution with more than two temperatures. (4) The ASCA spectra are of such high statistical significance that systematic uncertainties dominate, including atomic physics issues and calibration issues. (5) While the ASCA spectral fits achieve lower Chi(exp 2 with two-temperature fits, the EUVE-derived emission measure distribution models are also consistent with the spectra. (6) The Fe/H ratio obtained from the ASCA fit is within 20 % of the Fe/H abundance obtained from the summed spectra of Capella over 5 EUVE pointings, as well as the 1996 EUVE data. This result confirms our claims that quasi-continua composed of weak emission lines in the short wavelength spectrometer of EUVE are not major contributors to the measured Capella continuum. Other abundance ratios are also determined from the ASCA data, using models derived with EUVE. Si, Si, and Mg appear to be close to solar photospheric values, while the ratio of Ne/Fe is three to four times lower than solar photospheric values. Whether there is a general First Ionization Potential (FIP) effect or a specific neon anomaly cannot be determined

  3. Markers of fibroblast-rich tumor stroma and perivascular cells in serous ovarian cancer: Inter- and intra-patient heterogeneity and impact on survival

    PubMed Central

    Corvigno, Sara; Wisman, G. Bea A.; Mezheyeuski, Artur; van der Zee, Ate G.J.; Nijman, Hans W.; Åvall-Lundqvist, Elisabeth; Östman, Arne; Dahlstrand, Hanna

    2016-01-01

    Inter- and intra-patient variations in tumor microenvironment of serous ovarian cancer are largely unexplored. We aimed to explore potential co-regulation of tumor stroma characteristics, analyze their concordance in primary and metastatic lesions, and study their impact on survival. A tissue microarray (TMA) with 186 tumors and 91 matched metastases was subjected to immunohistochemistry double staining with endothelial cell marker CD34 and fibroblast and pericyte markers α-SMA, PDGFβR and desmin. Images were digitally analyzed to yield “metrics” related to vasculature and stroma features. Intra-case analyses showed that PDGFβR in perivascular cells and fibroblasts were strongly correlated. Similar findings were observed concerning α-SMA. Most stroma characteristics showed large variations in intra-case comparisons of primary tumors and metastasis. Large PDGFβR-positive stroma fraction and high PDGFβFR positive perivascular intensity were both significantly associated with shorter survival in uni- and multi-variate analyses (HR 1.7, 95% CI 1.1-2.5; HR 1.7, 95% CI 1.1-2.8). In conclusion, we found PDGFβR- and α-SMA-expression to be largely independent of each other but concordantly activated in perivascular cells and in fibroblasts within the primary tumor. Stromal characteristics differed between primary tumors and metastases. PDGFβR in perivascular cells and in fibroblasts may be novel prognostic markers in serous ovarian cancer. PMID:26918345

  4. Probing tumor-stroma interactions and response to photodynamic therapy in a 3D pancreatic cancer-fibroblast co-culture model

    NASA Astrophysics Data System (ADS)

    Glidden, Michael D.; Massodi, Iqbal; Rizvi, Imran; Celli, Jonathan P.; Hasan, Tayyaba

    2012-02-01

    Pancreatic ductal adenocarcinoma is a lethal disease that is often unresectable by the time of diagnosis and is typically non-responsive to chemo- and radiotherapy, resulting in a five year survival of only 3%. Tumors of the pancreas are characterized by a dense fibrous stroma rich in extracellular matrix proteins, which is implicated in poor therapeutic response, though its precise roles remain poorly understood. Indeed, while the use of therapeutics that target the stroma is an emerging paradigm in the clinical management of this disease, the primary focus of such efforts is to enhance drug penetration through dense fibrous stroma and it is unclear to what extent the characteristically rigid stroma of pancreatic tumors imparts drug resistance by acting as a complex signaling partner, or merely as a physical barrier for drug delivery. Here we use 3D in vitro co-cultures of pancreatic cancer cells and normal human fibroblasts as a model system to study heterotypic interactions between these populations. Leveraging this in vitro model along with image-based methods for quantification of growth and therapeutic endpoints, we characterize these co-cultures and examine the role of verteporfin-based photodynamic therapy (PDT) for targeting tumor-fibroblast interactions in pancreatic tumors.

  5. Capella: Structure and Abundances

    NASA Technical Reports Server (NTRS)

    Brickhouse, Nancy S.

    1999-01-01

    This grant covers the analysis of ASCA spectra of the cool star binary system Capella. This project has also required the analysis of simultaneous EUVE data. The ASCA spectrum of Capella could not be fit with standard models; by imposing models based on strong lines observed with EUVE, a problem wavelength region was identified. Correcting the problem required calculations of atomic collision strengths of higher principal quantum number than had ever been calculated, resulting in a paper in process by Liedahl and Brickhouse. With these new models applied to the ASCA spectrum, better fits were obtained. While solar abundance ratios are generally consistent with the ASCA data, the ratio of Ne/Fe is three to four times lower than solar photospheric values. Whether there is a general First Ionization Potential (FIP) effect or a specific neon anomaly cannot be determined from these data. Detailed discussion has been provided to NASA in the most recent annual report (1997). Two poster presentations have been made regarding modeling requirements. A substantial paper is in the final revision form, following review by six co-authors. The results of this work have wide implications, since the newly calculated emission lines almost certainly contribute to other problems in fitting not only other stellar spectra, but also composite supernova remnants, galaxies, and cooling flow clusters of galaxies. Furthermore, Liedahl and Brickhouse have identified other species for which lines of a similar nature (high principal quantum number) will contribute significant flux. For moderate resolution X-ray spectra, lines left out of the models in relatively isolated bands, will be attributed to continuum flux by spectral fitting engines, causing errors in line-to-continuum ratios. Thus addressing the general theoretical problem is of crucial importance.

  6. Abundances in dwarf irregular galaxies

    NASA Technical Reports Server (NTRS)

    Dufour, Reginald J.

    1986-01-01

    The results of abundance studies of dwarf irregular galaxies and similar objects are reviewed with special attention to variations in the CNO element group. Observations of the forbidden N II and semiforbidden C III lines in the most metal-poor galaxy known, IZw 18, are presented for the first time and CNO abundances are derived via a photoionization model and discussed in the context of the abundances found in other metal-poor H II regions and galaxies.

  7. Abundance coefficients, a new method for measuring microorganism relative abundance

    USGS Publications Warehouse

    Forester, R.M.

    1977-01-01

    A new method of measuring the relative abundance of microorganisms by using a set of interrelated coefficients, termed 'abundance coefficients' or 'AC', is proposed. These coefficients provide a means of recording abundance for geometric density categories, and each density measurement represents an approximation of the Poisson parameter ??t. The AC is the natural logarithm of a 'characteristic value,' which is a particular number for each geometric density category. The 'characteristic values' are based upon a probabilistic error statement derived from the Poisson formula, and they present evidence for separation of the geometric category boundaries by e = 2.71828. The proposed AC provide a means for recording species abundance in a manner suitable for arithmetic manipulation, for population structure studies, and for the determination of practical limits for defining the presence or absence of a species. Further, these coefficients provide for both intrasample and intersample abundance comparisons. ?? 1977 Plenum Publishing Corporation.

  8. Erratum: Interstellar Abundance Standards Revisited

    NASA Astrophysics Data System (ADS)

    Sofia, U. J.; Meyer, D. M.

    2001-09-01

    In the Letter ``Interstellar Abundance Standards Revisited'' by U. J. Sofia and D. M. Meyer (ApJ, 554, L221 [2001]), Table 2 and its footnotes contain several typographical errors. The corrected table is shown below. We note that the solar reference standard now implies a positive abundance of nitrogen in halo dust.

  9. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing

    PubMed Central

    Veréb, Zoltán; Póliska, Szilárd; Albert, Réka; Olstad, Ole Kristoffer; Boratkó, Anita; Csortos, Csilla; Moe, Morten C.; Facskó, Andrea; Petrovski, Goran

    2016-01-01

    Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases. PMID:27195722

  10. Automated tracking of tumor-stroma morphology in microtissues identifies functional targets within the tumor microenvironment for therapeutic intervention.

    PubMed

    Åkerfelt, Malin; Bayramoglu, Neslihan; Robinson, Sean; Toriseva, Mervi; Schukov, Hannu-Pekka; Härmä, Ville; Virtanen, Johannes; Sormunen, Raija; Kaakinen, Mika; Kannala, Juho; Eklund, Lauri; Heikkilä, Janne; Nees, Matthias

    2015-10-01

    Cancer-associated fibroblasts (CAFs) constitute an important part of the tumor microenvironment and promote invasion via paracrine functions and physical impact on the tumor. Although the importance of including CAFs into three-dimensional (3D) cell cultures has been acknowledged, computational support for quantitative live-cell measurements of complex cell cultures has been lacking. Here, we have developed a novel automated pipeline to model tumor-stroma interplay, track motility and quantify morphological changes of 3D co-cultures, in real-time live-cell settings. The platform consists of microtissues from prostate cancer cells, combined with CAFs in extracellular matrix that allows biochemical perturbation. Tracking of fibroblast dynamics revealed that CAFs guided the way for tumor cells to invade and increased the growth and invasiveness of tumor organoids. We utilized the platform to determine the efficacy of inhibitors in prostate cancer and the associated tumor microenvironment as a functional unit. Interestingly, certain inhibitors selectively disrupted tumor-CAF interactions, e.g. focal adhesion kinase (FAK) inhibitors specifically blocked tumor growth and invasion concurrently with fibroblast spreading and motility. This complex phenotype was not detected in other standard in vitro models. These results highlight the advantage of our approach, which recapitulates tumor histology and can significantly improve cancer target validation in vitro. PMID:26375443

  11. Cells from the adult corneal stroma can be reprogrammed to a neuron-like cell using exogenous growth factors

    SciTech Connect

    Greene, Carol Ann Chang, Chuan-Yuan; Fraser, Cameron J.; Nelidova, Dasha E.; Chen, Jing A.; Lim, Angela; Brebner, Alex; McGhee, Jennifer; Sherwin, Trevor; Green, Colin R.

    2014-03-10

    Cells thought to be stem cells isolated from the cornea of the eye have been shown to exhibit neurogenic potential. We set out to uncover the identity and location of these cells within the cornea and to elucidate their neuronal protein and gene expression profile during the process of switching to a neuron-like cell. Here we report that every cell of the adult human and rat corneal stroma is capable of differentiating into a neuron-like cell when treated with neurogenic differentiation specifying growth factors. Furthermore, the expression of genes regulating neurogenesis and mature neuronal structure and function was increased. The switch from a corneal stromal cell to a neuron-like cell was also shown to occur in vivo in intact corneas of living rats. Our results clearly indicate that lineage specifying growth factors can affect changes in the protein and gene expression profiles of adult cells, suggesting that possibly many adult cell populations can be made to switch into another type of mature cell by simply modifying the growth factor environment. - Highlights: • Adult corneal stromal cells can differentiated into neuron-like cells. • Neuronal specification of the adult stromal cell population is stochastic. • Neuronal specification in an adult cell population can be brought about by growth factors.

  12. Role of Human Corneal Stroma-Derived Mesenchymal-Like Stem Cells in Corneal Immunity and Wound Healing.

    PubMed

    Veréb, Zoltán; Póliska, Szilárd; Albert, Réka; Olstad, Ole Kristoffer; Boratkó, Anita; Csortos, Csilla; Moe, Morten C; Facskó, Andrea; Petrovski, Goran

    2016-01-01

    Corneal tissue regeneration is of crucial importance for maintaining normal vision. We aimed to isolate and cultivate human corneal stroma-derived mesenchymal stem-like cells (CSMSCs) from the central part of cadaver corneas and study their phenotype, multipotency, role in immunity and wound healing. The isolated cells grew as monolayers in vitro, expressed mesenchymal- and stemness-related surface markers (CD73, CD90, CD105, CD140b), and were negative for hematopoietic markers as determined by flow cytometry. CSMSCs were able to differentiate in vitro into fat, bone and cartilage. Their gene expression profile was closer to bone marrow-derived MSCs (BMMSCs) than to limbal epithelial stem cells (LESC) as determined by high-throughput screening. The immunosuppressive properties of CSMSCs were confirmed by a mixed lymphocyte reaction (MLR), while they could inhibit proliferation of activated immune cells. Treatment of CSMSCs by pro-inflammatory cytokines and toll-like receptor ligands significantly increased the secreted interleukin-6 (IL-6), interleukin-8 (IL-8) and C-X-C motif chemokine 10 (CXCL-10) levels, as well as the cell surface adhesion molecules. CSMSCs were capable of closing a wound in vitro under different stimuli. These cells thus contribute to corneal tissue homeostasis and play an immunomodulatory and regenerative role with possible implications in future cell therapies for treating sight-threatening corneal diseases. PMID:27195722

  13. Abnormalities of Thymic Stroma may Contribute to Immune Dysregulation in Murine Models of Leaky Severe Combined Immunodeficiency

    PubMed Central

    Rucci, Francesca; Poliani, Pietro Luigi; Caraffi, Stefano; Paganini, Tiziana; Fontana, Elena; Giliani, Silvia; Alt, Frederick W.; Notarangelo, Luigi Daniele

    2011-01-01

    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 severe combined immune deficiency, 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 autoimmune regulator (Aire) is preserved in mutant mice, the frequency of mature mTECs expressing Aire and tissue-specific antigens 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. PMID:21822418

  14. Stroma Cell-Derived Factor-1α Signaling Enhances Calcium Transients and Beating Frequency in Rat Neonatal Cardiomyocytes

    PubMed Central

    Hadad, Ielham; Veithen, Alex; Springael, Jean–Yves; Sotiropoulou, Panagiota A.; Mendes Da Costa, Agnès; Miot, Françoise; Naeije, Robert

    2013-01-01

    Stroma cell-derived factor-1α (SDF-1α) is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency. Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R) blocker, but not with a ryanodine receptor (RyR) antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax. These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect. PMID:23460790

  15. Tumour imaging by the detection of fibrin clots in tumour stroma using an anti-fibrin Fab fragment

    PubMed Central

    Obonai, Toshifumi; Fuchigami, Hirobumi; Furuya, Fumiaki; Kozuka, Naoyuki; Yasunaga, Masahiro; Matsumura, Yasuhiro

    2016-01-01

    The diagnosis of early and aggressive types of cancer is important for providing effective cancer therapy. Cancer-induced fibrin clots exist only within lesions. Previously, we developed a monoclonal antibody (clone 102-10) that recognizes insoluble fibrin but not fibrinogen or soluble fibrin and confirmed that fibrin clots form continuously in various cancers. Here, we describe the development of a Fab fragment probe of clone 102-10 for tumour imaging. The distribution of 102-10 Fab was investigated in genetically engineered mice bearing pancreatic ductal adenocarcinoma (PDAC), and its effect on blood coagulation was examined. Immunohistochemical and ex vivo imaging revealed that 102-10 Fab was distributed selectively in fibrin clots in PDAC tumours 3 h after injection and that it disappeared from the body after 24 h. 102-10 Fab had no influence on blood coagulation or fibrinolysis. Tumour imaging using anti-fibrin Fab may provide a safe and effective method for the diagnosis of invasive cancers by detecting fibrin clots in tumour stroma. PMID:27009516

  16. Increased expression of the collagen internalization receptor uPARAP/Endo180 in the stroma of head and neck cancer.

    PubMed

    Sulek, Jay; Wagenaar-Miller, Rebecca A; Shireman, Jessica; Molinolo, Alfredo; Madsen, Daniel H; Engelholm, Lars H; Behrendt, Niels; Bugge, Thomas H

    2007-04-01

    Local growth, invasion, and metastasis of malignancies of the head and neck involve extensive degradation and remodeling of the underlying, collagen-rich connective tissue. Urokinase plasminogen activator receptor-associated protein (uPARAP)/Endo180 is an endocytic receptor recently shown to play a critical role in the uptake and intracellular degradation of collagen by mesenchymal cells. As a step toward determining the putative function of uPARAP/Endo180 in head and neck cancer progression, we used immunohistochemistry to determine the expression of this collagen internalization receptor in 112 human squamous cell carcinomas and 19 normal or tumor-adjacent head and neck tissue samples from the tongue, gingiva, cheek, tonsils, palate, floor of mouth, larynx, maxillary sinus, upper jaw, nasopharynx/nasal cavity, and lymph nodes. Specificity of detection was verified by staining of serial sections with two different monoclonal antibodies against two non-overlapping epitopes on uPARAP/Endo180 and by the use of isotype-matched non-immune antibodies. uPARAP/Endo180 expression was observed in stromal fibroblast-like, vimentin-positive cells. Furthermore, expression of the collagen internalization receptor was increased in tumor stroma compared with tumor-adjacent connective tissue or normal submucosal connective tissue and was most prominent in poorly differentiated tumors. These data suggest that uPARAP/Endo180 participates in the connective tissue destruction during head and neck squamous cell carcinoma progression by mediating cellular uptake and lysosomal degradation of collagen. PMID:17189524

  17. Reactive stroma component COL6A1 is upregulated in castration-resistant prostate cancer and promotes tumor growth

    PubMed Central

    Shen, Yi-Jun; Wang, Hong-Kai; Zhang, Gui-Ming; Ye, Ding-Wei

    2015-01-01

    Castration-resistant prostate cancer (CRPC) remains the most critical challenge in the clinical management of prostate cancer (PCa). Reactive stromal changes in PCa are likely involved in the emergence of CRPC. In the present study, we identified a novel oncogene termed COL6A1 which was upregulated in the reactive stroma of CRPC. We established an androgen-independent LNCaP (LNCaP-AI) cell line in steroid-reduced (SR) medium within 2 months. We examined COL6A1 expression with western blot during the LNCaP-AI induction, and studied the function of COL6A1 in vitro and in vivo. Immunohistochemical staining of COL6A1 was performed in ten pairs of androgen-sensitive PCa and CRPC samples. We demonstrated that COL6A1 expression was markedly increased in LNCaP-AI cells and CRPC tissues compared with LNCaP cells and paired androgen-sensitive PCa specimens. In vitro, COL6A1 knockdown resulted in G1-S cell cycle arrest and descended vitality. Overexpression of COL6A1 was associated with accelerated S phase entry and elevated vitality in prostate cancer cells. COL6A1 also promoted tumorigenesis of LNCaP cells in vivo. Taken together, these data suggest an important role of COL6A1 in the molecular etiology of castration-resistant prostate cancer, and support the potential use of COL6A1 in CRPC therapy. PMID:25895032

  18. Automated tracking of tumor-stroma morphology in microtissues identifies functional targets within the tumor microenvironment for therapeutic intervention

    PubMed Central

    Åkerfelt, Malin; Bayramoglu, Neslihan; Robinson, Sean; Toriseva, Mervi; Schukov, Hannu-Pekka; Härmä, Ville; Virtanen, Johannes; Sormunen, Raija; Kaakinen, Mika; Kannala, Juho; Eklund, Lauri; Heikkilä, Janne; Nees, Matthias

    2015-01-01

    Cancer-associated fibroblasts (CAFs) constitute an important part of the tumor microenvironment and promote invasion via paracrine functions and physical impact on the tumor. Although the importance of including CAFs into three-dimensional (3D) cell cultures has been acknowledged, computational support for quantitative live-cell measurements of complex cell cultures has been lacking. Here, we have developed a novel automated pipeline to model tumor-stroma interplay, track motility and quantify morphological changes of 3D co-cultures, in real-time live-cell settings. The platform consists of microtissues from prostate cancer cells, combined with CAFs in extracellular matrix that allows biochemical perturbation. Tracking of fibroblast dynamics revealed that CAFs guided the way for tumor cells to invade and increased the growth and invasiveness of tumor organoids. We utilized the platform to determine the efficacy of inhibitors in prostate cancer and the associated tumor microenvironment as a functional unit. Interestingly, certain inhibitors selectively disrupted tumor-CAF interactions, e.g. focal adhesion kinase (FAK) inhibitors specifically blocked tumor growth and invasion concurrently with fibroblast spreading and motility. This complex phenotype was not detected in other standard in vitro models. These results highlight the advantage of our approach, which recapitulates tumor histology and can significantly improve cancer target validation in vitro. PMID:26375443

  19. Stroma derived COL6A3 is a potential prognosis marker of colorectal carcinoma revealed by quantitative proteomics

    PubMed Central

    Chen, Sun-Xia; Wang, Xiao-Qing; Cui, Shu-Jian; Liu, Xiao-Hui; Jiang, Ying-Hua; Wang, Jie; Zhang, Yang; Yang, Peng-Yuan; Liu, Feng

    2015-01-01

    Colorectal cancer (CRC) represents the third most common cancer in males and second in females worldwide. Here, we performed a quantitative 8-plex iTRAQ proteomics analysis of the secreted proteins from five colonic fibroblast cultures and three colon cancer epithelial cell lines. We identified 1114 proteins at 0% FDR, including 587 potential secreted proteins. We further recognized 116 fibroblast-enriched proteins which were significantly associated with cell movement, angiogenesis, proliferation and wound healing, and 44 epithelial cell-enriched proteins. By interrogation of Oncomine database, we found that 20 and 8 fibroblast-enriched proteins were up- and downregulated in CRC, respectively. Western blots confirmed the fibroblast-specific secretion of filamin C, COL6A3, COL4A1 and spondin-2. Upregulated mRNA and stroma expression of COL6A3 in CRC, which were revealed by Oncomine analyses and tissue-microarray-immunohistochemistry, indicated poor prognosis. COL6A3 expression was significantly associated with Dukes stage, T stage, stage, recurrence and smoking status. Circulating plasma COL6A3 in CRC patients was upregulated significantly comparing with healthy peoples. Receiver operating characteristic curve analysis revealed that COL6A3 has better predictive performance for CRC with an area under the curve of 0.885 and the best sensitivity/specificity of 92.9%/81.3%. Thus we demonstrated that COL6A3 was a potential diagnosis and prognosis marker of CRC. PMID:26338966

  20. Novel protein phosphorylation site identification in spinach stroma membranes by titanium dioxide microcolumns and tandem mass spectrometry.

    PubMed

    Rinalducci, Sara; Larsen, Martin R; Mohammed, Shabaz; Zolla, Lello

    2006-04-01

    In this work, spinach stroma membrane, instead of thylakoid, has been investigated for the presence of phosphorylated proteins. We identified seven previously unknown phosphorylation sites by taking advantage of TiO(2) phosphopeptides enrichment coupled to mass spectrometric analysis. Upon illumination at 100 micromol m(-2) s(-1), two novel phosphopeptides belonging to the N-terminal region of Lhcb1 light-harvesting protein were detected: NVSSGS(p)PWYGPDR and T(p)VQSSSPWYGPDR. Moreover, three new threonine residues in CP43 (Thr-6, Thr-8, and Thr-346) and, for the first time, two amino acid residues of the N-terminus of Rieske Fe-S protein of the cytochrome b(6)f complex (Thr-2 and Ser-3) were revealed to be phosphorylated. Since Lhcb1 and CP43 have been reported as mobile proteins, it may be suggested that illumination derived phosphorylation, and consequently the addition of negatively charged groups to the protein, is a necessary condition to induce a significant protein structural change. PMID:16602705

  1. IGF-1 receptor targeted nanoparticles for image-guided therapy of stroma-rich and drug resistant human cancer

    PubMed Central

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M.; Zhou, Zhiyang; Wang, Liya; Wang, Andrew; Mao, Hui

    2016-01-01

    Low drug delivery efficiency and drug resistance from highly heterogeneous cancer cells and tumor microenvironment represent major challenges in clinical oncology. Growth factor receptor, IGF-1R, is overexpressed in both human tumor cells and tumor associated stromal cells. The level of IGF-1R expression is further up-regulated in drug resistant tumor cells. We have developed IGF-1R targeted magnetic iron oxide nanoparticles (IONPs) carrying multiple anticancer drugs into human tumors. This IGF-1R targeted theranostic nanoparticle delivery system has an iron core for non-invasive MR imaging, amphiphilic polymer coating to ensure the biocompatibility as well as for drug loading and conjugation of recombinant human IGF-1 as targeting molecules. Chemotherapy drugs, Doxorubicin (Dox), was encapsulated into the polymer coating and/or conjugated to the IONP surface by coupling with the carboxyl groups. The ability of IGF1R targeted theranostic nanoparticles to penetrate tumor stromal barrier and enhance tumor cell killing has been demonstrated in human pancreatic cancer patient tissue derived xenograft (PDX) models. Repeated systemic administrations of those IGF-1R targeted theranostic IONP carrying Dox led to breaking the tumor stromal barrier and improved therapeutic effect. Near infrared (NIR) optical and MR imaging enabled noninvasive monitoring of nanoparticle-drug delivery and therapeutic responses. Our results demonstrated that IGF-1R targeted nanoparticles carrying multiple drugs are promising combination therapy approaches for image-guided therapy of stroma-rich and drug resistant human cancer, such as pancreatic cancer. PMID:27313332

  2. Quantitation of Murine Stroma and Selective Purification of the Human Tumor Component of Patient-Derived Xenografts for Genomic Analysis.

    PubMed

    Schneeberger, Valentina E; Allaj, Viola; Gardner, Eric E; Poirier, J T; Rudin, Charles M

    2016-01-01

    Patient-derived xenograft (PDX) mouse models are increasingly used for preclinical therapeutic testing of human cancer. A limitation in molecular and genetic characterization of PDX tumors is the presence of integral murine stroma. This is particularly problematic for genomic sequencing of PDX models. Rapid and dependable approaches for quantitating stromal content and purifying the malignant human component of these tumors are needed. We used a recently developed technique exploiting species-specific polymerase chain reaction (PCR) amplicon length (ssPAL) differences to define the fractional composition of murine and human DNA, which was proportional to the fractional composition of cells in a series of lung cancer PDX lines. We compared four methods of human cancer cell isolation: fluorescence-activated cell sorting (FACS), an immunomagnetic mouse cell depletion (MCD) approach, and two distinct EpCAM-based immunomagnetic positive selection methods. We further analyzed DNA extracted from the resulting enriched human cancer cells by targeted sequencing using a clinically validated multi-gene panel. Stromal content varied widely among tumors of similar histology, but appeared stable over multiple serial tumor passages of an individual model. FACS and MCD were superior to either positive selection approach, especially in cases of high stromal content, and consistently allowed high quality human-specific genomic profiling. ssPAL is a dependable approach to quantitation of murine stromal content, and MCD is a simple, efficient, and high yield approach to human cancer cell isolation for genomic analysis of PDX tumors. PMID:27611664

  3. Human periprostatic white adipose tissue is rich in stromal progenitor cells and a potential source of prostate tumor stroma.

    PubMed

    Ribeiro, Ricardo; Monteiro, Cátia; Silvestre, Ricardo; Castela, Angela; Coutinho, Helena; Fraga, Avelino; Príncipe, Paulo; Lobato, Carlos; Costa, Carla; Cordeiro-da-Silva, Anabela; Lopes, José Manuel; Lopes, Carlos; Medeiros, Rui

    2012-10-01

    A body of growing evidence now implicates white adipose tissue as a relevant source of stromal progenitor cells recruited to the tumor microenvironment to form supportive tumor stroma. While the role of periprostatic (PP) adipose tissue in prostate cancer progression has been barely appreciated, we sought to determine the progenitor cell population in PP adipose tissue and the association with prostate cancer. We isolated and characterized CD31(-)CD34(+)CD45(-)CD146(-) progenitor cells (adipose-derived stem cells [ASC]) in paired samples of PP and preperitoneal visceral adipose tissue from prostate tissue and peripheral blood mononuclear cells of prostate cancer and nodular prostatic hyperplasia patients. ASC were quantified by flow cytometry and confirmed through target gene expression. Here we show a significantly higher amount of ASC in PP than in visceral adipose tissue, independent of body mass index and prostatic disease. In the prostate, ASC are increased in cancer compared with prostatic nodular hyperplasia patients. Concordantly, adipsin gene (CFD) expression, which is known to be up-regulated in adipose stem cells, was overexpressed in PP adipose tissue, in the prostate of cancer patients and in prostate CD31(-)CD34(+)CD45(-)CD146(-) sorted cells. ASC were found at higher levels in the blood of prostate cancer patients simultaneously overweight/obese. Present findings indicate that PP adipose tissue is a reservoir of progenitor cells with the potential to migrate towards prostate tumors, although its clinical significance merits further evaluation. PMID:23038706

  4. Stroma derived COL6A3 is a potential prognosis marker of colorectal carcinoma revealed by quantitative proteomics.

    PubMed

    Qiao, Jie; Fang, Cai-Yun; Chen, Sun-Xia; Wang, Xiao-Qing; Cui, Shu-Jian; Liu, Xiao-Hui; Jiang, Ying-Hua; Wang, Jie; Zhang, Yang; Yang, Peng-Yuan; Liu, Feng

    2015-10-01

    Colorectal cancer (CRC) represents the third most common cancer in males and second in females worldwide. Here, we performed a quantitative 8-plex iTRAQ proteomics analysis of the secreted proteins from five colonic fibroblast cultures and three colon cancer epithelial cell lines. We identified 1114 proteins at 0% FDR, including 587 potential secreted proteins. We further recognized 116 fibroblast-enriched proteins which were significantly associated with cell movement, angiogenesis, proliferation and wound healing, and 44 epithelial cell-enriched proteins. By interrogation of Oncomine database, we found that 20 and 8 fibroblast-enriched proteins were up- and downregulated in CRC, respectively. Western blots confirmed the fibroblast-specific secretion of filamin C, COL6A3, COL4A1 and spondin-2. Upregulated mRNA and stroma expression of COL6A3 in CRC, which were revealed by Oncomine analyses and tissue-microarray-immunohistochemistry, indicated poor prognosis. COL6A3 expression was significantly associated with Dukes stage, T stage, stage, recurrence and smoking status. Circulating plasma COL6A3 in CRC patients was upregulated significantly comparing with healthy peoples. Receiver operating characteristic curve analysis revealed that COL6A3 has better predictive performance for CRC with an area under the curve of 0.885 and the best sensitivity/specificity of 92.9%/81.3%. Thus we demonstrated that COL6A3 was a potential diagnosis and prognosis marker of CRC. PMID:26338966

  5. Overcoming a species-specificity barrier in development of an inhibitory antibody targeting a modulator of tumor stroma

    PubMed Central

    Grossman, Iris; Ilani, Tal; Fleishman, Sarel Jacob; Fass, Deborah

    2016-01-01

    The secreted disulfide catalyst Quiescin sulfhydryl oxidase-1 (QSOX1) affects extracellular matrix organization and is overexpressed in various adenocarcinomas and associated stroma. Inhibition of extracellular human QSOX1 by a monoclonal antibody decreased tumor cell migration in a cell co-culture model and hence may have therapeutic potential. However, the species specificity of the QSOX1 monoclonal antibody has been a setback in assessing its utility as an anti-metastatic agent in vivo, a common problem in the antibody therapy industry. We therefore used structurally guided engineering to expand the antibody species specificity, improving its affinity toward mouse QSOX1 by at least four orders of magnitude. A crystal structure of the re-engineered variant, complexed with its mouse antigen, revealed that the antibody accomplishes dual-species targeting through altered contacts between its heavy and light chains, plus replacement of bulky aromatics by flexible side chains and versatile water-bridged polar interactions. In parallel, we produced a surrogate antibody targeting mouse QSOX1 that exhibits a new QSOX1 inhibition mode. This set of three QSOX1 inhibitory antibodies is compatible with various mouse models for pre-clinical trials and biotechnological applications. In this study we provide insights into structural blocks to cross-reactivity and set up guideposts for successful antibody design and re-engineering. PMID:26819240

  6. Possible contribution of prostatic anterior fibromuscular stroma to age-related urinary disturbance in reference to pressure-flow study.

    PubMed

    Ukimura, Osamu; Iwata, Tsuyoshi; Ushijima, So; Suzuki, Kei; Honjo, Hisashi; Okihara, Koji; Mizutani, Yoichi; Kawauchi, Akihiro; Miki, Tsuneharu

    2004-05-01

    Recently, we reported that the anterior fibromuscular stroma (AFMS) of the prostate has significant different innervation compared with the other glandular regions of the prostate. In healthy volunteers (n = 12) using transrectal ultrasound (US), or TRUS, monitoring during voiding, we observed dynamic change (p < 0.0001) of the thickness of the AFMS during voiding. The aim of this study was to reveal the possible functional contribution of the AFMS to micturition, as well as the age-related voiding dysfunction. In the patients (n = 56) with voiding dysfunction who underwent both pressure-flow study (PFS) for determining obstruction and TRUS monitoring during voiding, we measured the ultrasonic dynamic change of the lower urinary tract during voiding. In old men with voiding dysfunction, ultrasonic measurements of dynamic change in the AFMS (p < 0.01) as well as the opening urethra (p < 0.05) could contribute to diagnosing of the anatomical localization of obstructive lesions. The poor movement of AFMS could account for the age-related urinary disturbance in the patients without benign prostatic enlargement and without bladder neck obstruction. PMID:15183221

  7. Stroma cell-derived factor-1α signaling enhances calcium transients and beating frequency in rat neonatal cardiomyocytes.

    PubMed

    Hadad, Ielham; Veithen, Alex; Springael, Jean-Yves; Sotiropoulou, Panagiota A; Mendes Da Costa, Agnès; Miot, Françoise; Naeije, Robert; De Deken, Xavier; Entee, Kathleen Mc

    2013-01-01

    Stroma cell-derived factor-1α (SDF-1α) is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency.Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R) blocker, but not with a ryanodine receptor (RyR) antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax.These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect. PMID:23460790

  8. Suppression of CD51 in pancreatic stellate cells inhibits tumor growth by reducing stroma and altering tumor-stromal interaction in pancreatic cancer.

    PubMed

    Horioka, Kohei; Ohuchida, Kenoki; Sada, Masafumi; Zheng, Biao; Moriyama, Taiki; Fujita, Hayato; Manabe, Tatsuya; Ohtsuka, Takao; Shimamoto, Masaya; Miyazaki, Tetsuyuki; Mizumoto, Kazuhiro; Oda, Yoshinao; Nakamura, Masafumi

    2016-04-01

    Pancreatic stellate cells (PSCs) enhance the malignant behavior of pancreatic cancer by interacting with cancer cells and producing extracellular matrix (ECM). To date, several stroma-targeted therapies for pancreatic cancer have been attempted, but these therapies are still not in practical use. Integrins expressed in stromal cells are involved in fibrosis of several organs, as well as promoting tumor malignancy. We investigated whether CD51, also known as integrin αV, expressed in PSCs was associated with stromal formation of pancreatic cancer and enhancement of tumor malignancy. We also assessed the effects of suppression of CD51 in PSCs on pancreatic cancer. Immunohistochemistry for CD51 in resected pancreatic cancer tissues showed that high expression of CD51 in the tumor stroma was associated with lymph node metastasis (P=0.025), positive pathologic margin (P=0.025), and shorter patient survival times (P=0.043). Lentivirus-mediated short hairpin RNA knockdown of CD51 decreased the proliferation and migration of PSCs. Quantitative real-time polymerase chain reaction showed that expression levels of genes related with ECM and tumor-stromal interactions were decreased by CD51 knockdown in PSCs. In a co-implantation model of pancreatic cancer cells and PSCs, tumor growth in vivo was inhibited by CD51 knockdown in PSCs (P<0.05). We also found reduced tumor stroma and decreased proliferation of cancer cells in implanted cancer tissues with CD51-silenced PSCs (P<0.05). Our results showed that CD51 expression in pancreatic cancer stroma is associated with enhanced tumor malignancy and that CD51 may be a potential therapeutic target for pancreatic cancer. PMID:26846197

  9. Toward automatic segmentation and quantification of tumor and stroma in whole-slide images of H and E stained rectal carcinomas

    NASA Astrophysics Data System (ADS)

    Geessink, Oscar G. F.; Baidoshvili, Alexi; Freling, Gerard; Klaase, Joost M.; Slump, Cornelis H.; van der Heijden, Ferdinand

    2015-03-01

    Visual estimation of tumor and stroma proportions in microscopy images yields a strong, Tumor-(lymph)Node- Metastasis (TNM) classification-independent predictor for patient survival in colorectal cancer. Therefore, it is also a potent (contra)indicator for adjuvant chemotherapy. However, quantification of tumor and stroma through visual estimation is highly subject to intra- and inter-observer variability. The aim of this study is to develop and clinically validate a method for objective quantification of tumor and stroma in standard hematoxylin and eosin (H and E) stained microscopy slides of rectal carcinomas. A tissue segmentation algorithm, based on supervised machine learning and pixel classification, was developed, trained and validated using histological slides that were prepared from surgically excised rectal carcinomas in patients who had not received neoadjuvant chemotherapy and/or radiotherapy. Whole-slide scanning was performed at 20× magnification. A total of 40 images (4 million pixels each) were extracted from 20 whole-slide images at sites showing various relative proportions of tumor and stroma. Experienced pathologists provided detailed annotations for every extracted image. The performance of the algorithm was evaluated using cross-validation by testing on 1 image at a time while using the other 39 images for training. The total classification error of the algorithm was 9.4% (SD = 3.2%). Compared to visual estimation by pathologists, the algorithm was 7.3 times (P = 0.033) more accurate in quantifying tissues, also showing 60% less variability. Automatic tissue quantification was shown to be both reliable and practicable. We ultimately intend to facilitate refined prognostic stratification of (colo)rectal cancer patients and enable better personalized treatment.

  10. The boron abundance of Procyon

    NASA Technical Reports Server (NTRS)

    Lemke, Michael; Lambert, David L.; Edvardsson, Bengt

    1993-01-01

    The B I 2496.8 A resonance line and HST/GHRS echelle spectra are used with model atmospheres and synthetic spectra to derive the B abundance of the F dwarfs Procyon (Alpha Canis Minoris), Theta Ursae Majoris, and Iota Pegasi. The B abundance of Theta UMa and Iota Peg is similar to that derived by Boesgaard and Heacox (1978) from the B II resonance line in spectra of A- and B-type stars. These two dwarfs show normal abundances of Li, Be, and B. Procyon, which is highly depleted in Li and Be, is depleted in B by a factor of at least 3. Comparison of the spectra of Procyon and the halo dwarf HD 140283 shows that the B abundance assigned by Duncan et al. (1992) to three halo dwarfs is not greatly overestimated as a result of contamination of the B I line by an unidentified line.

  11. Cystic tumor of the liver without ovarian-like stroma or bile duct communication: two case reports and a review of the literature.

    PubMed

    Kishida, Norihiro; Shinoda, Masahiro; Masugi, Yohei; Itano, Osamu; Fujii-Nishimura, Yoko; Ueno, Akihisa; Kitago, Minoru; Hibi, Taizo; Abe, Yuta; Yagi, Hiroshi; Tanimoto, Akihiro; Tanabe, Minoru; Sakamaoto, Michiie; Kitagawa, Yuko

    2014-01-01

    We report two cases of cystic neoplasm of the liver with mucinous epithelium in which both ovarian-like stroma and bile duct communication were absent. The first case was a 41-year-old woman. She underwent right trisegmentectomy due to a multilocular cystic lesion, 15 cm in diameter, with papillary nodular components in the medial segment and right lobe. Histologically, arborizing papillae were seen in the papillary lesion. The constituent neoplastic cells had sufficient cytoarchitectural atypia to be classified as high-grade dysplasia. The second case was a 60-year-old woman. She underwent left lobectomy due to a unilocular cystic lesion, 17 cm in diameter, in the left lobe. Histologically, the cyst wall was lined by low columnar epithelia with slight cellular atypia. In both cases, neither ovarian-like stroma nor bile duct communications were found throughout the resected specimen. According to the most recent World Health Organization (WHO) classification in 2010, cystic tumors of the liver with mucinous epithelium are classified as mucinous cystic neoplasms when ovarian-like stromata are found, and as intraductal papillary neoplasm of bile duct when bile duct communication exists. Therefore, we diagnosed the cystic tumors as 'biliary cystadenoma' according to the past WHO classification scheme from 2000. We believe that the combined absence of both ovarian-like stroma and bile duct communication is possible in mucinous cystic tumors of the liver. Herein, we have described the clinicopathologic features of the two cases and reviewed past cases in the literature. PMID:25047921

  12. Spectrum of cutaneous and soft tissue lesions in two Carney complex patients-adnexal induction versus authentic adnexal neoplasms.

    PubMed

    Kacerovska, Denisa; Requena, Luis; Michal, Michal; Grossmann, Petr; Treskova, Inka; Roucka, Patrik; Kazakov, Dmitry V

    2012-10-01

    Two unusual Carney complex patients are described. In one of them, several cutaneous biopsies revealed myxoid lesions that were rather more close to authentic adnexal neoplasms with myxoid stroma than to a "myxoma with an epithelial component." These included lesions resembling trichofolliculoma, infundibular cyst, and trichodiscoma. Additionally, 1 soft tissue myxoma was unique in the sense that it greatly resembled a cardiac myxoma, begging the question whether this could represent an embolus from the patient's cardiac myxoma. Given the large size and complexity and heterogeneity of the cutaneous lesions, the authors suggest that these may represent authentic cutaneous neoplasms accompanied by myxoid stroma and not adnexal elements induced by the stroma. However, the latter mechanism is well recognized and demonstrated by our second patient in whom adnexal-type elements in the cutaneous lesion were clearly induced by the myxoid stroma but were unusually complex by manifesting panfollicular and also sebaceous differentiation. PMID:22588545

  13. The Molecular Signature of the Stroma Response in Prostate Cancer-Induced Osteoblastic Bone Metastasis Highlights Expansion of Hematopoietic and Prostate Epithelial Stem Cell Niches

    PubMed Central

    Secondini, Chiara; Wetterwald, Antoinette; Schwaninger, Ruth; Fleischmann, Achim; Raffelsberger, Wolfgang; Poch, Olivier; Delorenzi, Mauro; Temanni, Ramzi; Mills, Ian G.; van der Pluijm, Gabri; Thalmann, George N.; Cecchini, Marco G.

    2014-01-01

    The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature (“Core” OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this

  14. The molecular signature of the stroma response in prostate cancer-induced osteoblastic bone metastasis highlights expansion of hematopoietic and prostate epithelial stem cell niches.

    PubMed

    Özdemir, Berna C; Hensel, Janine; Secondini, Chiara; Wetterwald, Antoinette; Schwaninger, Ruth; Fleischmann, Achim; Raffelsberger, Wolfgang; Poch, Olivier; Delorenzi, Mauro; Temanni, Ramzi; Mills, Ian G; van der Pluijm, Gabri; Thalmann, George N; Cecchini, Marco G

    2014-01-01

    The reciprocal interaction between cancer cells and the tissue-specific stroma is critical for primary and metastatic tumor growth progression. Prostate cancer cells colonize preferentially bone (osteotropism), where they alter the physiological balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption, and elicit prevalently an osteoblastic response (osteoinduction). The molecular cues provided by osteoblasts for the survival and growth of bone metastatic prostate cancer cells are largely unknown. We exploited the sufficient divergence between human and mouse RNA sequences together with redefinition of highly species-specific gene arrays by computer-aided and experimental exclusion of cross-hybridizing oligonucleotide probes. This strategy allowed the dissection of the stroma (mouse) from the cancer cell (human) transcriptome in bone metastasis xenograft models of human osteoinductive prostate cancer cells (VCaP and C4-2B). As a result, we generated the osteoblastic bone metastasis-associated stroma transcriptome (OB-BMST). Subtraction of genes shared by inflammation, wound healing and desmoplastic responses, and by the tissue type-independent stroma responses to a variety of non-osteotropic and osteotropic primary cancers generated a curated gene signature ("Core" OB-BMST) putatively representing the bone marrow/bone-specific stroma response to prostate cancer-induced, osteoblastic bone metastasis. The expression pattern of three representative Core OB-BMST genes (PTN, EPHA3 and FSCN1) seems to confirm the bone specificity of this response. A robust induction of genes involved in osteogenesis and angiogenesis dominates both the OB-BMST and Core OB-BMST. This translates in an amplification of hematopoietic and, remarkably, prostate epithelial stem cell niche components that may function as a self-reinforcing bone metastatic niche providing a growth support specific for osteoinductive prostate cancer cells. The induction of this

  15. Blood-Based Biomarkers Are Associated with Disease Recurrence and Survival in Gastrointestinal Stroma Tumor Patients after Surgical Resection

    PubMed Central

    Stotz, Michael; Liegl-Atzwanger, Bernadette; Posch, Florian; Mrsic, Edvin; Thalhammer, Michael; Stojakovic, Tatjana; Bezan, Angelika; Pichler, Martin; Gerger, Armin; Szkandera, Joanna

    2016-01-01

    Background Inflammatory blood count biomarkers may improve recurrence risk stratification and inform long-term prognosis of cancer patients. Here, we quantify the prognostic impact of blood-based biomarkers on recurrence risk and long-term survival in a large cohort of gastrointestinal stroma tumor (GIST) patients after curative surgery. Methods One-hundred-forty-nine consecutive GIST patients were followed-up for a median period of 4.8 years. Local recurrence, distant metastasis, and death occurred in 9, 21, and 31 patients, respectively. Time-to-event and competing risk analysis were applied to study the association between haemoglobin (Hb) level, white blood cell count (WBC), neutrophil/lymphocyte ratio (NLR), derived NLR (dNLR), lymphocyte/monocyte ratio (LMR), and platelet/lymphocyte ratio (PLR) with risk of local or distant recurrence (RR), recurrence free survival (RFS), and overall survival (OS). Results A low Hb (p = 0.029), and elevations in the parameters WBC (p = 0.004), NLR (p = 0.015) and dNLR (p = 0.037) were associated with a poor OS in GIST patients in multivariate analysis. Moreover, a low Hb (p = 0.049) and an elevated WBC (p = 0.001), NLR (p = 0.007), dNLR (p = 0.043) and PLR (p = 0.024) were independently associated with decreased RFS after adjusting for Miettinen score. However, only an increase of dNLR/NLR showed a significant association to higher RR (p = 0.048). Inclusion of NLR or PLR to Miettinen risk score did not reasonably improve the clinical risk prediction of 2-year RFS. Conclusion Low Hb, elevated WBC, elevated dNLR, and elevated PLR are independent prognostic factors for a worse clinical outcome in GIST patients after curative resection. PMID:27454486

  16. Tbx18 Regulates the Differentiation of Periductal Smooth Muscle Stroma and the Maintenance of Epithelial Integrity in the Prostate

    PubMed Central

    Guimarães-Camboa, Nuno; Zhang, Huimin; Troy, Joseph M.; Lu, Xiaochen; Kispert, Andreas; Evans, Sylvia M.; Stubbs, Lisa

    2016-01-01

    The T-box transcription factor TBX18 is essential to mesenchymal cell differentiation in several tissues and Tbx18 loss-of-function results in dramatic organ malformations and perinatal lethality. Here we demonstrate for the first time that Tbx18 is required for the normal development of periductal smooth muscle stromal cells in prostate, particularly in the anterior lobe, with a clear impact on prostate health in adult mice. Prostate abnormalities are only subtly apparent in Tbx18 mutants at birth; to examine postnatal prostate development we utilized a relatively long-lived hypomorphic mutant and a novel conditional Tbx18 allele. Similar to the ureter, cells that fail to express Tbx18 do not condense normally into smooth muscle cells of the periductal prostatic stroma. However, in contrast to ureter, the periductal stromal cells in mutant prostate assume a hypertrophic, myofibroblastic state and the adjacent epithelium becomes grossly disorganized. To identify molecular events preceding the onset of this pathology, we compared gene expression in the urogenital sinus (UGS), from which the prostate develops, in Tbx18-null and wild type littermates at two embryonic stages. Genes that regulate cell proliferation, smooth muscle differentiation, prostate epithelium development, and inflammatory response were significantly dysregulated in the mutant urogenital sinus around the time that Tbx18 is first expressed in the wild type UGS, suggesting a direct role in regulating those genes. Together, these results argue that Tbx18 is essential to the differentiation and maintenance of the prostate periurethral mesenchyme and that it indirectly regulates epithelial differentiation through control of stromal-epithelial signaling. PMID:27120339

  17. Solar and stellar photospheric abundances

    NASA Astrophysics Data System (ADS)

    Allende Prieto, Carlos

    2016-07-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  18. Robust Abundance Estimation in Animal Abundance Surveys with Imperfect Detection

    EPA Science Inventory

    Surveys of animal abundance are central to the conservation and management of living natural resources. However, detection uncertainty complicates the sampling process of many species. One sampling method employed to deal with this problem is depletion (or removal) surveys in whi...

  19. Coronal abundances and their variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1995-01-01

    This contract supports the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution soft X-ray spectra from the Flat Crystal Spectrometer on the Solar Maximum Mission. The goals of the study are a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This report is a summation of the data analysis and reporting activities which occurred during the period of 15 April 1994 to 15 April 1995.

  20. The solar abundance of beryllium

    NASA Technical Reports Server (NTRS)

    Ross, J. E.; Aller, L. H.

    1974-01-01

    The solar abundance of beryllium is deduced from high-resolution Kitt Peak observations of the 3130.43- and 3131.08-A lines of Be II interpreted by the method of spectrum synthesis. The results are in good agreement with those previously obtained by Grevesse (1968) and by Hauge and Engvold (1968) and indicate that in the photospheric layers, beryllium is depleted below the chondritic value by a factor of about two. It is found that the beryllium abundance is equal to logN(Be)/N(H) + 12 = 1.08 plus or minus 0.05.

  1. Chemical Abundances of Symbiotic Giants

    NASA Astrophysics Data System (ADS)

    Gałan, C.; Mikołajewska, J.; Hinkle, K. H.; Joyce, R. R.

    2015-12-01

    High resolution (R ˜ 50000), near-IR spectra were used to measure photospheric abundances of CNO and elements around the iron peak for 24 symbiotic giants. Spectrum synthesis was employed using local thermal equilibrium and hydrostatic model atmospheres. The metallicities are distributed in a wide range with maximum around [Fe/H] ˜-0.4 - - 0.3 dex. Enrichment in 14N indicates that all the sample giants have experienced the first dredge-up. The relative abundance of [Ti/Fe] is generally large in red symbiotic systems.

  2. Coronal Abundances and Their Variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1996-01-01

    This contract supported the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution soft X-ray spectra from the Flat Crystal Spectrometer on NASA's Solar Maximum Mission. The goals of the study were a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This is the Final Report, summarizing the data analysis and reporting activities which occurred during the period of performance, June 1993 - December 1996.

  3. SOLAR MODELS WITH REVISED ABUNDANCE

    SciTech Connect

    Bi, S. L.; Li, T. D.; Yang, W. M.; Li, L. H.

    2011-04-20

    We present new solar models in which we use the latest low abundances and further include the effects of rotation, magnetic fields, and extra-mixing processes. We assume that the extra-element mixing can be treated as a diffusion process, with the diffusion coefficient depending mainly on the solar internal configuration of rotation and magnetic fields. We find that such models can well reproduce the observed solar rotation profile in the radiative region. Furthermore, the proposed models can match the seismic constraints better than the standard solar models, also when these include the latest abundances, but neglect the effects of rotation and magnetic fields.

  4. THE SOLAR FLARE IRON ABUNDANCE

    SciTech Connect

    Phillips, K. J. H.; Dennis, B. R. E-mail: Brian.R.Dennis@nasa.gov

    2012-03-20

    The abundance of iron is measured from emission line complexes at 6.65 keV (Fe line) and 8 keV (Fe/Ni line) in RHESSI X-ray spectra during solar flares. Spectra during long-duration flares with steady declines were selected, with an isothermal assumption and improved data analysis methods over previous work. Two spectral fitting models give comparable results, viz., an iron abundance that is lower than previous coronal values but higher than photospheric values. In the preferred method, the estimated Fe abundance is A(Fe) = 7.91 {+-} 0.10 (on a logarithmic scale, with A(H) = 12) or 2.6 {+-} 0.6 times the photospheric Fe abundance. Our estimate is based on a detailed analysis of 1898 spectra taken during 20 flares. No variation from flare to flare is indicated. This argues for a fractionation mechanism similar to quiet-Sun plasma. The new value of A(Fe) has important implications for radiation loss curves, which are estimated.

  5. Clinicopathologic Characteristics of 29 Invasive Carcinomas Arising in 178 Pancreatic Mucinous Cystic Neoplasms With Ovarian-type Stroma

    PubMed Central

    Jang, Kee-Taek; Park, Sang Mo; Basturk, Olca; Bagci, Pelin; Bandyopadhyay, Sudeshna; Stelow, Edward B.; Walters, Dustin M.; Choi, Dong Wook; Choi, Seoung Ho; Heo, Jin Seok; Sarmiento, Juan M.; Reid, Michelle D.; Adsay, Volkan

    2015-01-01

    Information on the clinicopathologic characteristics of invasive carcinomas arising from mucinous cystic neoplasms (MCNs) is limited, because in many early studies they were lumped and analyzed together with noninvasive MCNs. Even more importantly, many of the largest prior studies did not require ovarian-type stroma (OTS) for diagnosis. We analyzed 178 MCNs, all strictly defined by the presence of OTS, 98% of which occurred in perimenopausal women (mean age, 47 y) and arose in the distal pancreas. Twenty-nine (16%) patients had associated invasive carcinoma, and all were female with a mean age of 53. Invasion was far more common in tumors with grossly visible intracystic papillary nodule formation ≥ 1.0 cm (79.3% vs. 8.7%, P = 0.000) as well as in larger tumors (mean cyst size: 9.4 vs. 5.4 cm, P = 0.006); only 4/29 (14%) invasive carcinomas occurred in tumors that were < 5 cm; however, none were < 3 cm. Increased serum CA19-9 level (> 37 U/L) was also more common in the invasive tumors (64% vs. 23%, P = 0.011). Most invasive carcinomas (79%) were of tubular type, and the remainder (5 cases) were mostly undifferentiated carcinoma (2, with osteoclast-like giant cells), except for 1 with papillary features. Interestingly, there were no colloid carcinomas; 2 patients had nodal metastasis at the time of diagnosis, and both died of disease at 10 and 35 months, respectively. While noninvasive MCNs had an excellent prognosis (100% at 5 y), tumors with invasion often had an aggressive clinical course with 3- and 5-year survival rates of 44% and 26%, respectively (P = 0.000). The pT2 (> 2 cm) invasive tumors had a worse prognosis than pTl (≤ 2 cm) tumors (P = 0.000), albeit 3 patients with T1a (< 0.5 cm) disease also died of disease. In conclusion, invasive carcinomas are seen in 16% of MCNs and are mostly of tubular (pancreatobiliary) type; colloid carcinoma is not seen in MCNs. Serum CA19-9 is often higher in invasive carcinomas, and invasion is typically seen in OTS

  6. Actinide abundances in ordinary chondrites

    USGS Publications Warehouse

    Hagee, B.; Bernatowicz, T.J.; Podosek, F.A.; Johnson, M.L.; Burnett, D.S.; Tatsumoto, M.

    1990-01-01

    Measurements of 244Pu fission Xe, U, Th, and light REE (LREE) abundances, along with modal petrographic determinations of phosphate abundances, were carried out on equilibrated ordinary chondrites in order to define better the solar system Pu abundance and to determine the degree of variation of actinide and LREE abundances. Our data permit comparison of the directly measured Pu/ U ratio with that determined indirectly as (Pu/Nd) ?? (Nd/U) assuming that Pu behaves chemically as a LREE. Except for Guaren??a, and perhaps H chondrites in general, Pu concentrations are similar to that determined previously for St. Se??verin, although less precise because of higher trapped Xe contents. Trapped 130Xe 136Xe ratios appear to vary from meteorite to meteorite, but, relative to AVCC, all are similar in the sense of having less of the interstellar heavy Xe found in carbonaceous chondrite acid residues. The Pu/U and Pu/Nd ratios are consistent with previous data for St. Se??verin, but both tend to be slightly higher than those inferred from previous data on Angra dos Reis. Although significant variations exist, the distribution of our Th/U ratios, along with other precise isotope dilution data for ordinary chondrites, is rather symmetric about the CI chondrite value; however, actinide/(LREE) ratios are systematically lower than the CI value. Variations in actinide or LREE absolute and relative abundances are interpreted as reflecting differences in the proportions and/or compositions of more primitive components (chondrules and CAI materials?) incorporated into different regions of the ordinary chondrite parent bodies. The observed variations of Th/U, Nd/U, or Ce/U suggest that measurements of Pu/U on any single equilibrated ordinary chondrite specimen, such as St. Se??verin, should statistically be within ??20-30% of the average solar system value, although it is also clear that anomalous samples exist. ?? 1990.

  7. Small-angle neutron scattering study of the ultrastructure of chloroplast thylakoid membranes - periodicity and structural flexibility of the stroma lamellae.

    PubMed

    Posselt, Dorthe; Nagy, Gergely; Kirkensgaard, Jacob J K; Holm, Jens K; Aagaard, Thomas H; Timmins, Peter; Rétfalvi, Eszter; Rosta, László; Kovács, László; Garab, Győző

    2012-08-01

    The multilamellar organization of freshly isolated spinach and pea chloroplast thylakoid membranes was studied using small-angle neutron scattering. A broad peak at ~0.02Å(-1) is ascribed to diffraction from domains of ordered, unappressed stroma lamellae, revealing a repeat distance of 294ű7Å in spinach and 345ű11Å in pea. The peak position and hence the repeat distance of stroma lamellae is strongly dependent on the osmolarity and the ionic strength of the suspension medium, as demonstrated by varying the sorbitol and the Mg(++)-concentration in the sample. For pea thylakoid membranes, we show that the repeat distance decreases when illuminating the sample with white light, in accordance with our earlier results on spinach, also regarding the observation that addition of an uncoupler prohibits the light-induced structural changes, a strong indication that these changes are driven by the transmembrane proton gradient. We show that the magnitude of the shrinkage is strongly dependent on light intensity and that the repeat distance characteristic of the dark state after illumination is different from the initial dark state. Prolonged strong illumination leads to irreversible changes and swelling as reflected in increased repeat distances. The observed reorganizations are discussed within the frames of the current structural models of the granum-stroma thylakoid membrane assembly and the regulatory mechanisms in response to variations in the environmental conditions in vivo. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial. PMID:22306529

  8. Extracting a low-dimensional description of multiple gene expression datasets reveals a potential driver for tumor-associated stroma in ovarian cancer.

    PubMed

    Celik, Safiye; Logsdon, Benjamin A; Battle, Stephanie; Drescher, Charles W; Rendi, Mara; Hawkins, R David; Lee, Su-In

    2016-01-01

    Patterns in expression data conserved across multiple independent disease studies are likely to represent important molecular events underlying the disease. We present the INSPIRE method to infer modules of co-expressed genes and the dependencies among the modules from multiple expression datasets that may contain different sets of genes. We show that INSPIRE infers more accurate models than existing methods to extract low-dimensional representation of expression data. We demonstrate that applying INSPIRE to nine ovarian cancer datasets leads to a new marker and potential driver of tumor-associated stroma, HOPX, followed by experimental validation. The implementation of INSPIRE is available at http://inspire.cs.washington.edu . PMID:27287041

  9. Coronal abundances and their variation

    NASA Technical Reports Server (NTRS)

    Saba, Julia L. R.

    1994-01-01

    This contract supports the investigation of elemental abundances in the solar corona, principally through analysis of high-resolution software X-ray spectra from the Flat Crystal Spectrometer on NASA's Solar Maximum Mission. The goals of the study are a characterization of the mean values of relative abundances of elements accessible in the FCS data, and information on the extent and circumstances of their variability. This report is a summation of the data analysis and reporting activities which occurred since the last report, submitted two months early, in April 1994, to facilitate evaluation of the first year's progress for contract renewal. Hence this report covers the period 15 April 1994 - 15 December 1994. A list of publications resulting from this research is included.

  10. The solar abundance of thulium

    NASA Technical Reports Server (NTRS)

    Ross, J. E.; Aller, L. H.

    1974-01-01

    Consideration of one relatively unblended line of the solar spectrum, namely, the 3131.258-A line of Tm II, which yields a thulium abundance of 0.80 plus or minus 0.10 with the Corliss and Bozman (1962) f-value. The uncertainty of this figure is discussed in conjunction with the contradictory findings of some other investigators. The need for further detailed study of the lanthanides by the method of spectrum synthesis is pointed out.

  11. Chlorine Abundances in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Bogard, D.D.; Garrison, D.H.; Park, J.

    2009-01-01

    Chlorine measurements made in martian surface rocks by robotic spacecraft typically give Chlorine (Cl) abundances of approximately 0.1-0.8%. In contrast, Cl abundances in martian meteorites appear lower, although data is limited, and martian nakhlites were also subjected to Cl contamination by Mars surface brines. Chlorine abundances reported by one lab for whole rock (WR) samples of Shergotty, ALH77005, and EET79001 range 108-14 ppm, whereas Cl in nakhlites range 73-1900 ppm. Measurements of Cl in various martian weathering phases of nakhlites varied 0.04-4.7% and reveal significant concentration of Cl by martian brines Martian meteorites contain much lower Chlorine than those measured in martian surface rocks and give further confirmation that Cl in these surface rocks was introduced by brines and weathering. It has been argued that Cl is twice as effective as water in lowering the melting point and promoting melting at shallower martian depths, and that significant Cl in the shergottite source region would negate any need for significant water. However, this conclusion was based on experiments that utilized Cl concentrations more analogous to martian surface rocks than to shergottite meteorites, and may not be applicable to shergottites.

  12. Surface abundances of OC supergiants

    NASA Astrophysics Data System (ADS)

    Martins, F.; Foschino, S.; Bouret, J.-C.; Barbá, R.; Howarth, I.

    2016-04-01

    Context. Some O and B stars show unusually strong or weak lines of carbon and/or nitrogen. These objects are classified as OBN or OBC stars. It has recently been shown that nitrogen enrichment and carbon depletion are the most likely explanations for the existence of the ON class. Aims: We investigate OC stars (all being supergiants) to check that surface abundances are responsible for the observed anomalous line strengths. Methods: We perform a spectroscopic analysis of three OC supergiants using atmosphere models. A fourth star was previously studied by us. Our sample thus comprises all OC stars known to date in the Galaxy. We determine the stellar parameters and He, C, N, and O surface abundances. Results: We show that all stars have effective temperatures and surface gravities fully consistent with morphologically normal O supergiants. However, OC stars show little, if any, nitrogen enrichment and carbon surface abundances consistent with the initial composition. OC supergiants are thus barely chemically evolved, unlike morphologically normal O supergiants. Based on observations obtained at the ESO/La Silla Observatory under programs 081.D-2008, 083.D-0589, 089.D-0975.

  13. The Abundance of Interstellar Fluorine

    NASA Technical Reports Server (NTRS)

    Lauroesch, James T.

    2005-01-01

    The primary objective of this program was to obtain FUSE observations of the interstellar absorption lines of F I at 951 and 954 Angstroms to derive the abundance of fluorine toward the star HD 164816. The nucleosynthetic source(s) of fluorine are still a matter of debate - the present day abundance of fluorine can potentially constrain models for pulsationally driven dredge-up in asymptotic giant branch stars. An accurate measure for the depletion behavior of fluorine will determine whether it may be detectable in QSO absorption line systems - an unambiguous detection of fluorine at suitably high redshifts would provide the best evidence to date for the neutrino process in massive stars. Furthermore, due to its extreme reactivity, measurement of the gas-phase interstellar fluorine abundance is important for models of grain chemistry. Despite the importance of measuring the interstellar fluorine abundance, at the time of our proposal only one previous detection has been made due to the low relative abundance of fluorine, the lack of lines outside the far-UV, and the blending of the available F I transitions with lines of Hz. The star HD 164816 is associated with the Lagoon nebula (M8), and at a distance of approximately 1.5 kpc probes both distant and local gas. Beginning April 8th, 2004 FUSE FP-Split observations of the star HD 164816 were obtained for this program. This data became available in the FUSE data archive May 21, 2004, and these observations were then downloaded and we began our analysis. Our analysis procedure has involved (1) fitting stellar models to the FUSE spectra, (2) using the multiple lines of Hz and N I at other wavelengths in the FUSE bandpass to derive column densities for the lines of H2 and N I which are blended with the F I features at 951 and 954 angstroms (3) the measurement of the column densities of F I and the species O I and C1 I which are important species for the dis-entangling of dust and nucleosynthetic effects. As discussed in

  14. Tissue Proteomics Reveals Differential and Compartment-Specific Expression of the Homologs Transgelin and Transgelin-2 in Lung Adenocarcinoma and Its Stroma

    PubMed Central

    Rho, Jung-hyun; Roehrl, Michael H. A.; Wang, Julia Y.

    2009-01-01

    Discovery of tissue-specific biomarkers for human cancer is crucial for early diagnosis and molecular understanding of the disease. To overcome the limitations posed by the large dynamic concentration range and compositional complexity of tissue biomacromolecules, we applied heparin affinity fractionation for proteomic enrichment. Comparing the proteomes of five paired samples of normal lung and pulmonary adenocarcinoma tissue by 2-D difference gel electrophoresis, 14 spots were found to be differentially expressed. From these candidate spots, three proteins overexpressed in cancer were identified by mass spectrometry as transgelin (TAGLN, SM22-α, WS3-10), transgelin-2 (TAGLN2), and cyclophilin A (PPIA). Quantitative RT-PCR indicated that both TAGLN2 and PPIA were upregulated at transcriptional level. Differential protein expression levels were validated by Western blot analysis using an independent set of 10 paired lung adenocarcinoma samples. Using immunohistochemistry on human tissue sections, we discovered that overexpression of TAGLN was strictly localized to the tumor-induced reactive myofibroblastic stromal tissue compartment, whereas overexpression of TAGLN2 was exclusively localized to the neoplastic glandular compartment. Thus, the highly homologous protein pair TAGLN and TAGLN2 displayed mutually exclusive, compartment-specific cell type expression regulation in tumor stroma vs. neoplastic epithelial cells. Our data further suggest that TGLN may be a marker of active stromal remodeling in the vicinity of invasive carcinomas. It may shed light on mechanisms of tumor-stroma interaction and could be useful for early diagnosis, treatment guidance, and treatment response monitoring. PMID:19848416

  15. Separation of light-induced linear, cyclic and stroma-sourced electron fluxes to P700+ in cucumber leaf discs after pre-illumination at a chilling temperature.

    PubMed

    Fan, Da-Yong; Hope, Alexander B; Jia, Husen; Chow, Wah Soon

    2008-06-01

    Pre-illumination of cucumber leaf discs at 4 degrees C with low-irradiance white light (i) led to a marked decrease in the extent of photo-oxidation of P700 (the special chlorophyll pair in the PSI reaction center) in actinic light at room temperature and (ii) hastened the post-illumination re-reduction of P700+. Quantifying the linear, cyclic and stroma-sourced electron fluxes to P700+ in two actinic light regimes, we found that there was no increase in cyclic or linear electron fluxes to account for these changes. Rather, we observed a decrease in the maximum extent of P700 photo-oxidation assayed by a strong flash superimposed on continuous, background light of wavelength 723 nm, which we interpret to represent a loss of stable charge separation in PSI due to enhanced charge recombination as a result of the pre-illumination treatment. The funneling of electrons towards fewer non-damaged PSI complexes could explain the hastened post-illumination re-reduction of P700+, aided by a slight increase in a stroma-sourced electron flux after prolonged pre-illumination at 4 degrees C. Quantifying the separate fluxes to P700+ helps to elucidate the effects of chilling of cucumber leaf discs in the light and the reasons for the hastened post-illumination re-reduction of P700+. PMID:18426807

  16. Defining lymphocyte-predominant breast cancer by the proportion of lymphocyte-rich stroma and its significance in routine histopathological diagnosis.

    PubMed

    Ohtani, Haruo; Mori-Shiraishi, Kazuko; Nakajima, Morio; Ueki, Hamaichi

    2015-12-01

    Lymphocyte-predominant breast cancer (LPBC) defined by the density of stromal lymphocytes shows favorable behavior. However, considerable distribution heterogeneity of lymphocytes is a major problem. The present study defined LPBC by the proportion of lymphocyte-rich stroma with the cut-off values of 30, 50, and 75%, and clinicopathologically analyzed mainly LPBC (area > 30%) defined by the cut-off value of 30%. LPBCs (area > 30%), 39 cases in total, were composed mainly of triple-negative and HER2(+) /ER(-) subtypes, without any luminal A-like subtype. LPBCs were composed predominantly of histological grade 3 tumors, without any grade 1 lesions. Multivariate analyses on 477 consecutive tumors revealed that ER-negativity and grade 3 status associated significantly with LPBC. LPBC (area > 30%) showed better disease-free survival than grade-matched controls, and it was a good indicator of complete pathological remission after pre-operative chemotherapy. Patients with LPBC with the cut-off value of 50% and that of 75% showed 100% disease-free survival. These results demonstrated the validity of our definition of LPBC. Our data also suggest that de-differentiated cancers without TILs could be regarded as high-grade cancer without lymphocyte-mediated responses. In conclusion, the definition of LPBC by the proportion of lymphoid stroma is useful for prognostication of high grade breast cancer in routine diagnosis. PMID:26530981

  17. Origin of cosmic chemical abundances

    NASA Astrophysics Data System (ADS)

    Maio, Umberto; Tescari, Edoardo

    2015-11-01

    Cosmological N-body hydrodynamic computations following atomic and molecular chemistry (e-, H, H+, H-, He, He+, He++, D, D+, H2, H_2^+, HD, HeH+), gas cooling, star formation and production of heavy elements (C, N, O, Ne, Mg, Si, S, Ca, Fe, etc.) from stars covering a range of mass and metallicity are used to explore the origin of several chemical abundance patterns and to study both the metal and molecular content during simulated galaxy assembly. The resulting trends show a remarkable similarity to up-to-date observations of the most metal-poor damped Lyman α absorbers at redshift z ≳ 2. These exhibit a transient nature and represent collapsing gaseous structures captured while cooling is becoming effective in lowering the temperature below ˜ 104 K, before they are disrupted by episodes of star formation or tidal effects. Our theoretical results agree with the available data for typical elemental ratios, such as [C/O], [Si/Fe], [O/Fe], [Si/O], [Fe/H], [O/H] at redshifts z ˜ 2-7. Correlations between H I and H2 abundances show temporal and local variations and large spreads as a result of the increasing cosmic star formation activity from z ˜ 6 to 3. The scatter we find in the abundance ratios is compatible with the observational data and is explained by simultaneous enrichment by sources from different stellar phases or belonging to different stellar populations. Simulated synthetic spectra support the existence of metal-poor cold clumps with large optical depth at z ˜ 6 that could be potential Population III sites at low or intermediate redshift. The expected dust content is in line with recent determinations.

  18. Element abundances of classical novae

    NASA Astrophysics Data System (ADS)

    Andrea, J.; Drechsel, H.; Starrfield, S.

    1994-11-01

    Physical conditions and element abundances in the optically thin shells of 11 classical novae with outbursts between 1978 and 1989 were determined from an analysis of UV and optical spectra obtained during the nebular stage. Eight novae were studied on the basis of new optical and UV spectra. The accuracy of the element abundances depends on whether or not simultaneous UV spectra were available to determine individual ionization stage dependent gas temperatures. Generally, slightly higher than solar abundances of helium and pronounced overabundances of the heavier elements were found. QU Vul turned out to be an ONeMg nova, while the other objects belong to the class of CO novae. The nature of V2214 Oph could not be completely clarified. The novae V1668 Cyg (1978), V693 CrA (1981), and V1370 Aql (1982), for which published element abundances exist, were reanalyzed to check the consistency of our spectral analysis approach. Satisfactory agreement of the results was found. Photoionization calculations were carried out for PW Vul using the code of Aldrovandi, Pequignot, and Stasinska. A synthetic spectrum was generated for the parameters derived from the analysis of the UV and optical spectra, which is in very good agreement with the observations. The spectral analysis technique was then applied to the model spectrum and reproduced the model parameters well. Electron temperatures for the C(2+) and C(3+) ions between 7 500 and 12,000 K and for N(4+) betwen 12,000 and 16,000 K were derived. For PW Vul these temperatures remained relatively constant over several months. The decline in density of the ejected shells with time could be investigated for V842 Cen, QV Vul, V977 Sco, and V443 Sct, and was found to deviate from the relation Ne proportional to t-2 for free expansion of a shell in a different way for each object. A possible explanation may be the complex density structure of the shells. This suspicion is supported by high resolution spectra (ESO 3.6m telescope

  19. Abundance measurements in stellar environments

    NASA Astrophysics Data System (ADS)

    Leone, F.

    2014-05-01

    Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit. These notes are dedicated to the recently passed, November 21, 2013, Prof. Dimitri Mihalas who spent his life confuting the 19th century positivist philosopher Auguste Comte who stated that we shall not at all be able to determine the chemical composition of stars.

  20. Abundance measurements in stellar environments

    SciTech Connect

    Leone, F.

    2014-05-09

    Most of what we know about stars, and systems of stars, is derived from the analysis of their electromagnetic radiation. This lesson is an attempt to describe to Physicists, without any Astrophysical background, the framework to understand the present status of abundance determination in stellar environments and its limit. These notes are dedicated to the recently passed, November 21, 2013, Prof. Dimitri Mihalas who spent his life confuting the 19th century positivist philosopher Auguste Comte who stated that we shall not at all be able to determine the chemical composition of stars.

  1. The solar abundance of Oxygen

    NASA Astrophysics Data System (ADS)

    Grevesse, N.

    2009-07-01

    With Martin Asplund (Max Planck Institute of Astrophysics, Garching) and Jacques Sauval (Observatoire Royal de Belgique, Brussels) I recently published detailed reviews on the solar chemical composition ({Asplund et al. 2005}, {Grevesse et al. 2007}). A new one, with Pat Scott (Stockholm University) as additional co-author, will appear in Annual Review of Astronomy and Astrophysics ({Asplund et al. 2009}). Here we briefly analyze recent works on the solar abundance of Oxygen and recommend a value of 8.70 in the usual astronomical scale.

  2. Elemental Abundances in NGC 3516

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; Kraemer, S. B.; Mushotzky, R. F.; George, I. M.; Gabel, J. R.

    2003-01-01

    We present Reflection Grating Spectrometer data from an XMM-Newton observation of the Seyfert 1 galaxy NGC 3516, taken while the continuum source was in an extremely low flux state. This observation offers a rare opportunity for a detailed study of emission from a Seyfert 1 galaxy as these are usually dominated by high nuclear continuum levels and heavy absorption. The spectrum shows numerous narrow emission lines (FWHM approximately less than 1300 kilometers per second) in the 0.3 - 2 keV range, including the H-like lines of C, N, and O and the He-like lines of N, O and Ne. The emission-line ratios and the narrow width of the radiative recombination continuum of CVI indicate that the gas is photoionized and of fairly low temperature (kT approximately less than 0.01 keV). The availability of emission lines from different elements for two iso-electronic sequences allows us to constrain the element abundances. These data show that the N lines are far stronger than would be expected from gas of solar abundances. Based on our photoionization models we find that nitrogen is overabundant in the central regions of the galaxy, compared to carbon, oxygen and neon by at least a factor of 2.5. We suggest that this is the result of secondary production of nitrogen in intermediate mass stars, and indicative of the history of star formation in NGC 3516.

  3. Abundance patterns in planetary nebulae

    NASA Astrophysics Data System (ADS)

    Henry, Richard B. C.

    1990-06-01

    Abundances of He, N, O, and Ne have been uniformly calculated for 192 planetary nebulas residing in the Galactic disk and halo, the LMC, the SMC, and M31. Direct correlations appear to exist for type I as well as non-type I objects for the following pairs of parameters: N/O-He/H, N/O-N/H, and Ne/H-O/H. Separately, type I planetaries show a weak anticorrelation between N/O and O/H, while non-type I's exhibit direct correlations between N/H and O/H and between N/O and O/H. From these patterns, it is inferred that non-type I's synthesize N via the CN cycle. Type I planetaries, on the other hand, manufacture N at least partially via the ON cycle, destroying O in the process. Neither type appears to synthesize O or Ne.

  4. Stroma-induced Jagged1 expression drives PC3 prostate cancer cell migration; disparate effects of RIP-generated proteolytic fragments on cell behaviour and Notch signaling.

    PubMed

    Delury, Craig; Hart, Claire; Brown, Mick; Clarke, Noel; Parkin, Edward

    2016-03-25

    The Notch ligand Jagged1 is subject to regulated intramembrane proteolysis (RIP) which yields a soluble ectodomain (sJag) and a soluble Jagged1 intracellular domain (JICD). The full-length Jagged1 protein enhances prostate cancer (PCa) cell proliferation and is highly expressed in metastatic cells. However, little is known regarding the mechanisms by which Jagged1 or its RIP-generated fragments might promote PCa bone metastasis. In the current study we show that bone marrow stroma (BMS) induces Jagged1 expression in bone metastatic prostate cancer PC3 cells and that this enhanced expression is mechanistically linked to the promotion of cell migration. We also show that RIP-generated Jagged1 fragments exert disparate effects on PC3 cell behaviour and Notch signaling. In conclusion, the expression of both the full-length ligand and its RIP-generated fragments must be considered in tandem when attempting to regulate Jagged1 as a possible PCa therapy. PMID:26921446

  5. 3, 3', 5-triiodo-L-thyronine Increases In Vitro Chondrogenesis of Mesenchymal Stem Cells From Human Umbilical Cord Stroma Through SRC2.

    PubMed

    Fernández-Pernas, Pablo; Fafián-Labora, Juan; Lesende-Rodriguez, Iván; Mateos, Jesús; De la Fuente, Alexandre; Fuentes, Isaac; De Toro Santos, Javier; Blanco García, Fco; Arufe, María C

    2016-09-01

    Our group focuses on the study of mesenchymal stem cells (MSCs) from human umbilical cord stroma or Warthońs jelly and their directed differentiation toward chondrocyte-like cells capable of regenerating damaged cartilage when transplanted into an injured joint. This study aimed to determine whether lactogenic hormone prolactin (PRL) or 3, 3', 5-triiodo-L-thyronine (T3), the active thyroid hormone, modulates chondrogenesis in our in vitro model of directed chondrogenic differentiation, and whether Wnt signalling is involved in this modulation. MSCs from human umbilical cord stroma underwent directed differentiation toward chondrocyte-like cells by spheroid formation. The addition of T3 to the chondrogenic medium increased the expression of genes linked to chondrogenesis like collagen type 2, integrin alpha 10 beta 1, and Sox9 measured by quantitative real time polymerase chain reaction (qRT-PCR) analysis. Levels of collagen type 2 and aggrecane analyzed by immunohistochemistry, and staining by Safranin O were increased after 14 days in spheroid culture with T3 compared to those without T3 or only with PRL. B-catenin, Frizzled, and GSK-3β gene expressions were significantly higher in spheroids cultured with chondrogenic medium (CM) plus T3 compared to CM alone after 14 days in culture. The increase of chondrogenic differentiation was inhibited when the cells were treated with T3 plus ML151, an inhibitor of the T3 steroid receptor. This work demonstrates, for first time, that T3 promotes differentiation towards chondrocytes-like cells in our in vitro model, that this differentiation is mediated by steroid receptor co-activator 2 (SRC2) and does not induce hypertrophy. J. Cell. Biochem. 117: 2097-2108, 2016. © 2016 Wiley Periodicals, Inc. PMID:26869487

  6. Understanding of the Viscoelastic Response of the Human Corneal Stroma Induced by Riboflavin/UV-A Cross-Linking at the Nano Level

    PubMed Central

    Labate, Cristina; De Santo, Maria Penelope; Lombardo, Giuseppe; Lombardo, Marco

    2015-01-01

    Purpose To investigate the viscoelastic changes of the human cornea induced by riboflavin/UV-A cross-linking using Atomic Force Microscopy (AFM) at the nano level. Methods Seven eye bank donor corneas were investigated, after gently removing the epithelium, using a commercial AFM in the force spectroscopy mode. Silicon cantilevers with tip radius of 10 nm and spring elastic constants between 26- and 86-N/m were used to probe the viscoelastic properties of the anterior stroma up to 3 µm indentation depth. Five specimens were tested before and after riboflavin/UV-A cross-linking; the other two specimens were chemically cross-linked using glutaraldehyde 2.5% solution and used as controls. The Young’s modulus (E) and the hysteresis (H) of the corneal stroma were quantified as a function of the application load and scan rate. Results The Young’s modulus increased by a mean of 1.1-1.5 times after riboflavin/UV-A cross-linking (P<0.05). A higher increase of E, by a mean of 1.5-2.6 times, was found in chemically cross-linked specimens using glutaraldehyde 2.5% (P<0.05). The hysteresis decreased, by a mean of 0.9-1.5 times, in all specimens after riboflavin/UV-A cross-linking (P<0.05). A substantial decrease of H, ranging between 2.6 and 3.5 times with respect to baseline values, was observed in glutaraldehyde-treated corneas (P<0.05). Conclusions The present study provides the first evidence that riboflavin/UV-A cross-linking induces changes of the viscoelastic properties of the cornea at the scale of stromal molecular interactions. PMID:25830534

  7. Evaluation of T, B and natural killer lymphocyte in the cervical stroma of HIV-positive and negative patients with cervical intraepithelial neoplasia.

    PubMed

    Lucena, Adriana A S; Guimarães, Mírian Viviane M B; Michelin, Márcia A; Lodi, Cláudia T C; Lima, Maria Inês M; Murta, Eddie Fernando Candido; Melo, Victor Hugo

    2016-01-01

    Cervical intraepithelial neoplasias (CIN) are closely associated with oncogenic subtypes of the human papillomavirus (HPV). In the presence of this virus, it is known that the activation or suppression of immune system is the key to the development, progression and/or regression of cervical lesions. Therefore, the objective of this study is to compare the local immune response among HIV-seropositive and seronegative patients with cervical intraepithelial neoplasia regarding the expression of T lymphocytes (CD3+, CD4+ and CD8+), B lymphocytes (CD20+) and natural killers cells (CD56+) in the cervical stroma. A cross-sectional study of paraffin blocks containing cervical tissue after conization by the Loop Electrosurgical Excision Procedure (LEEP) from 47 HIV-seropositive and 38 seronegative patients with CIN. Cervical stroma immunohistochemistry was performed in the CIN area. The Fisher's exact test was used for the statistical analysis. When HIV-seropositive and seronegative women were compared, the seropositive women had a higher count of CD8+ T lymphocytes (52.1% versus 28.9%, P<0.04). Considering CIN degree (CIN 1 and CIN 2/3), the HIV-seronegative patients with CIN 1 had a low count of CD20+B-lymphocytes (7.1%) in comparison with CIN 1 HIV seropositive and with CIN 2/3 HIV-seronegative patients, respectively 50% (P<0.018) and 54.5% (P<0.0048). The HIV infection and degree of CIN influenced the cytotoxic lymphocytes inducing an increase in the number of cells high count of CD20+ lymphocytes with CIN 1. PMID:26545568

  8. Improved adipogenic in vitro differentiation: comparison of different adipogenic cell culture media on human fat and bone stroma cells for fat tissue engineering.

    PubMed

    Ghoniem, Amir-Alexander; Açil, Yahya; Wiltfang, Jörg; Gierloff, Matthias

    2015-06-01

    To date there is no sufficient in vitro fat tissue engineering and a protocol has not been well established for this purpose. Therefore, we evaluated the in vitro influence of two different adipogenic growth media for their stimulation potential on different cell lineages to clearly define the most potent adipogenic growth media for future in vitro tissue engineering approaches. The samples for differentiation were composed of human adipogenic-derived stroma cells (hADSCs) and human bone marrow mesenchymal stroma cells (hMSCs). A normal adipogenic medium (NAM) and a specific adipogenic medium (SAM) were tested for their adipogenic stimulation potential. After 10 days and 21 days the relative gene expression was measured for the adipogenic marker genes PPARγ2, C/EBPα, FABP4, LPL, and GLUT4 detected through real time reverse transcriptase polymease chain reaction (RT-PCR). Other study variables were the comparison between NAM and SAM and between the used cells hADSCs and hMSCs. Additionally an Oil-Red staining was performed after 21 days. Our results revealed that only SAM was significantly (P<0.05) superior in the differentiation process in contrast to NAM for 10 days and 21 days. As well was SAM superior to differentiate the used cell lineages. This was evaluated by the detected marker genes PPARγ2, C/EBPα, FABP4, LPL, and GLUT4 through real time RT-PCR and by Oil-Red staining. In addition, the hMSCs proofed to be equal donor cells for adipogenic differentiation especially when stimulated by SAM. The results suggest that the SAM should be established as a new standard medium for a more promising in vitro adipogenic differentiation. PMID:26140219

  9. Amino-Biphosphonate–Mediated MMP-9 Inhibition Breaks the Tumor-Bone Marrow Axis Responsible for Myeloid-Derived Suppressor Cell Expansion and Macrophage Infiltration in Tumor Stroma

    PubMed Central

    Melani, Cecilia; Sangaletti, Sabina; Barazzetta, Francesca M.; Werb, Zena; Colombo, Mario P.

    2009-01-01

    BALB-neuT mice expressing an activated rat c-erbB-2/neu transgene under the mouse mammary tumor virus long terminal repeat show enhanced hematopoiesis with hyperproduction of myeloid-derived suppressor cells (MDSC) because of vascular endothelial growth factor (VEGF) secreted by the tumor. Here, we show that both tumor and stromal cells express matrix metalloproteinase-9 (MMP-9), thereby increasing the levels of pro–MMP-9 in the sera of tumor-bearing mice. Treatment with amino-biphosphonates impaired tumor growth, significantly decreased MMP-9 expression and the number of macrophages in tumor stroma, and reduced MDSC expansion both in bone marrow and peripheral blood by dropping serum pro–MMP-9 and VEGF. We dissected the role of tumor-derived MMP-9 from that secreted by stromal leukocytes by transplanting bone marrow from MMP-9 knockout mice into BALB-neuT mice. Although bone marrow progenitor–derived MMP-9 had a major role in driving MDSC expansion, amino-biphosphonate treatment of bone marrow chimeras further reduced both myelopoiesis and the supportive tumor stroma, thus enhancing tumor necrosis. Moreover, by reducing MDSC, amino-biphosphonates overcome the tumor-induced immune suppression and improved the generation and maintenance of antitumor immune response induced by immunization against the p185/HER-2. Our data reveal that suppression of MMP-9 activity breaks the vicious loop linking tumor growth and myeloid cell expansion, thus reducing immunosuppression. Amino-biphosphonates disclose a specific MMP-9 inhibitory activity that may broaden their application above their current usage. PMID:18056472

  10. Lithium Abundance in Planet Search Stars

    NASA Astrophysics Data System (ADS)

    Myles, Justin; Yale Exoplanets

    2016-01-01

    Since most lithium in the universe is primordial and is destroyed in stars, lithium abundance can be used as a stellar age indicator. Some research seems to show that planet formation may also affect lithium abundance in exoplanet host stars (EHS). However, small and heterogenous samples have made both of these phenomena unclear. Further study of lithium abundance in EHS is needed to better understand possible physical roles of lithium in planet formation theory. We use a large homogenous sample with accurate stellar parameters on which we will use equivalent width analysis to determine precise lithium abundances. From these abundance values we determine an age vs. abundance relation. Additionally, we aim to explore correlation between lithium abundance and planet formation.

  11. Surface abundances of ON stars

    NASA Astrophysics Data System (ADS)

    Martins, F.; Simón-Díaz, S.; Palacios, A.; Howarth, I.; Georgy, C.; Walborn, N. R.; Bouret, J.-C.; Barbá, R.

    2015-06-01

    Context. Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient or when mass transfer in binary systems occurs, chemically processed material is observed at the surface of O and B stars. Aims: ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle is not known. Our goal is to answer this question. Methods: We performed a spectroscopic analysis of a sample of ON stars with atmosphere models. We determined the fundamental parameters as well as the He, C, N, and O surface abundances. We also measured the projected rotational velocities. We compared the properties of the ON stars to those of normal O stars. Results: We show that ON stars are usually rich in helium. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cannot account for the extreme enrichment observed among ON main sequence stars. Some ON stars are members of binary systems, but others are single stars as indicated by stable radial velocities. Mass transfer is therefore not a simple explanation for the observed chemical properties. Conclusions: We conclude that ON stars show extreme chemical enrichment at their surface, consistent with nucleosynthesis through the CNO cycle. Its origin is not clear at present. Based on observations obtained 1) at the Anglo-Australian Telescope; 2) at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii; 3) at the ESO/La Silla Observatory under programs 081.D-2008, 083.D-0589, 086.D-0997; 4) the Nordic Optical Telescope, operated on the island of La

  12. Significant biases affecting abundance determinations

    NASA Astrophysics Data System (ADS)

    Wesson, Roger

    2015-08-01

    I have developed two highly efficient codes to automate analyses of emission line nebulae. The tools place particular emphasis on the propagation of uncertainties. The first tool, ALFA, uses a genetic algorithm to rapidly optimise the parameters of gaussian fits to line profiles. It can fit emission line spectra of arbitrary resolution, wavelength range and depth, with no user input at all. It is well suited to highly multiplexed spectroscopy such as that now being carried out with instruments such as MUSE at the VLT. The second tool, NEAT, carries out a full analysis of emission line fluxes, robustly propagating uncertainties using a Monte Carlo technique.Using these tools, I have found that considerable biases can be introduced into abundance determinations if the uncertainty distribution of emission lines is not well characterised. For weak lines, normally distributed uncertainties are generally assumed, though it is incorrect to do so, and significant biases can result. I discuss observational evidence of these biases. The two new codes contain routines to correctly characterise the probability distributions, giving more reliable results in analyses of emission line nebulae.

  13. Histological and immunohistochemical evaluation of stroma variations and their correlation with the Ki-67 index and expressions of glucose transporter 1 and monocarboxylate transporter 1 in canine thyroid C-cell carcinomas.

    PubMed

    Kawamura, Yoshio; Mizooku, Hiroko; Okamoto, Minoru; Matsuda, Kazuya; Omachi, Tetsuo; Hirayama, Kazuko; Kadosawa, Tsuyoshi; Taniyama, Hiroyuki

    2016-05-01

    Canine thyroid C-cell carcinomas (CTCCs) are malignant tumors derived from calcitonin-producing C-cells of the thyroid gland. This study aimed to investigate the histological diversity of CTCCs from the viewpoint of stroma variations and to investigate their components by histological and immunohistochemical analyses including semiquantitative analysis of the density of microvessels (MVs) and α-SMA-positive cell count. Moreover, we examined whether the variations correlated with the Ki-67 index and expressions of glucose transporter 1 (GLUT-1) and monocarboxylate transporter 1 (MCT-1). Three stroma types (reticular, R, nest, N, and trabecular, T) were observed in CTCCs, and 21 cases were divided into 3 variations based on their combinations: mixed R and N (R/N) (n=7), simple N (n=7) and mixed T and N (T/N) (n=7). Immunohistochemically, stroma types depended on morphological features of α-SMA/fibronectin/laminin/collagen type IV-positive stroma cells. The density of MVs in R/N tended to be highest, and the density of those in N was significantly higher than the density of those in T/N (P=0.028). The α-SMA-positive cell count for N tended to be the lowest among the 3 variations. The Ki-67 index for R/N was significantly higher than those of the other variations (vs. N, P=0.007; vs. T/N, P=0.03), and that for T/N tended to be higher than that for N. Although there were no significant differences, GLUT-1 and MCT-1 expressions tended to be low in N. We concluded that stroma variations reflect tumor cell proliferation and expressions of GLUT-1 and MCT-1 in CTCCs. PMID:26726103

  14. Histological and immunohistochemical evaluation of stroma variations and their correlation with the Ki-67 index and expressions of glucose transporter 1 and monocarboxylate transporter 1 in canine thyroid C-cell carcinomas

    PubMed Central

    KAWAMURA, Yoshio; MIZOOKU, Hiroko; OKAMOTO, Minoru; MATSUDA, Kazuya; OMACHI, Tetsuo; HIRAYAMA, Kazuko; KADOSAWA, Tsuyoshi; TANIYAMA, Hiroyuki

    2016-01-01

    Canine thyroid C-cell carcinomas (CTCCs) are malignant tumors derived from calcitonin-producing C-cells of the thyroid gland. This study aimed to investigate the histological diversity of CTCCs from the viewpoint of stroma variations and to investigate their components by histological and immunohistochemical analyses including semiquantitative analysis of the density of microvessels (MVs) and α-SMA-positive cell count. Moreover, we examined whether the variations correlated with the Ki-67 index and expressions of glucose transporter 1 (GLUT-1) and monocarboxylate transporter 1 (MCT-1). Three stroma types (reticular, R, nest, N, and trabecular, T) were observed in CTCCs, and 21 cases were divided into 3 variations based on their combinations: mixed R and N (R/N) (n=7), simple N (n=7) and mixed T and N (T/N) (n=7). Immunohistochemically, stroma types depended on morphological features of α-SMA/fibronectin/laminin/collagen type IV-positive stroma cells. The density of MVs in R/N tended to be highest, and the density of those in N was significantly higher than the density of those in T/N (P=0.028). The α-SMA-positive cell count for N tended to be the lowest among the 3 variations. The Ki-67 index for R/N was significantly higher than those of the other variations (vs. N, P=0.007; vs. T/N, P=0.03), and that for T/N tended to be higher than that for N. Although there were no significant differences, GLUT-1 and MCT-1 expressions tended to be low in N. We concluded that stroma variations reflect tumor cell proliferation and expressions of GLUT-1 and MCT-1 in CTCCs. PMID:26726103

  15. Immunohistochemical analysis of steroidogenic enzymes in ovarian-type stroma of pancreatic mucinous cystic neoplasms: Comparative study of subepithelial stromal cells in intraductal papillary mucinous neoplasms of the pancreas.

    PubMed

    Ishida, Kazuyuki; Sasano, Hironobu; Moriya, Takuya; Takahashi, Yayoi; Sugimoto, Ryo; Mue, Yoshiharu; Murakami, Keigo; Fujishima, Fumiyoshi; Nakamura, Yasuhiro; Morikawa, Takanori; Motoi, Fuyuhiko; Suzuki, Takashi; Unno, Michiaki; Sugai, Tamotsu

    2016-05-01

    Mucinous cystic neoplasms (MCNs) are generally defined as cyst-forming epithelial neoplasms that arise in the pancreas and harbor characteristic ovarian-type stroma beneath the epithelium. In this study, we compared the immunoreactivity of steroid-related factors in these subepithelial stromal cells in MCNs to those in intraductal papillary mucinous neoplasms (IPMNs) to further characterize this unique MCN ovarian-type stroma through evaluation of sex steroid biosynthesis. Twenty MCNs and twenty IPMNs were examined. Immunoreactivity of steroid hormone receptors, including estrogen receptor (ERα and ERβ), progesterone receptor (PR, PR-A, and PR-B), and androgen receptor (AR), was more frequently detected in MCN ovarian-type stromal cells than in IPMN stromal cells (P < 0.01). The H-scores (mean ± SD) of steroidogenic factor (SF)-1 were also significantly higher in MCNs (112.3 ± 33.1) than in IPMNs (0.9 ± 1.2) (P < 0.01). The steroidogenic enzymes cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), cytochrome P450 17 alpha-hydroxylase (P450c17) and 3β-hydroxysteroid dehydrogenase (3β-HSD) showed immunoreactivity in 9/20 (45.0 %), 15/20 (75.0 %) and 13/20 (65.0 %), respectively, of ovarian-type stroma from MCN cases. These results demonstrate that the ovarian-type stroma of MCNs can express steroidogenic enzymes. Thus, the ovarian-type stroma of MCNs can produce sex steroids that may also act on these cells. PMID:27060902

  16. Cold-regulated cereal chloroplast late embryogenesis abundant-like proteins. Molecular characterization and functional analyses.

    PubMed

    NDong, Christian; Danyluk, Jean; Wilson, Kenneth E; Pocock, Tessa; Huner, Norman P A; Sarhan, Fathey

    2002-07-01

    Cold acclimation and freezing tolerance are the result of complex interaction between low temperature, light, and photosystem II (PSII) excitation pressure. Previous results have shown that expression of the Wcs19 gene is correlated with PSII excitation pressure measured in vivo as the relative reduction state of PSII. Using cDNA library screening and data mining, we have identified three different groups of proteins, late embryogenesis abundant (LEA) 3-L1, LEA3-L2, and LEA3-L3, sharing identities with WCS19. These groups represent a new class of proteins in cereals related to group 3 LEA proteins. They share important characteristics such as a sorting signal that is predicted to target them to either the chloroplast or mitochondria and a C-terminal sequence that may be involved in oligomerization. The results of subcellular fractionation, immunolocalization by electron microscopy and the analyses of target sequences within the Wcs19 gene are consistent with the localization of WCS19 within the chloroplast stroma of wheat (Triticum aestivum) and rye (Secale cereale). Western analysis showed that the accumulation of chloroplastic LEA3-L2 proteins is correlated with the capacity of different wheat and rye cultivars to develop freezing tolerance. Arabidopsis was transformed with the Wcs19 gene and the transgenic plants showed a significant increase in their freezing tolerance. This increase was only evident in cold-acclimated plants. The putative function of this protein in the enhancement of freezing tolerance is discussed. PMID:12114590

  17. Cold-Regulated Cereal Chloroplast Late Embryogenesis Abundant-Like Proteins. Molecular Characterization and Functional Analyses

    PubMed Central

    NDong, Christian; Danyluk, Jean; Wilson, Kenneth E.; Pocock, Tessa; Huner, Norman P.A.; Sarhan, Fathey

    2002-01-01

    Cold acclimation and freezing tolerance are the result of complex interaction between low temperature, light, and photosystem II (PSII) excitation pressure. Previous results have shown that expression of the Wcs19 gene is correlated with PSII excitation pressure measured in vivo as the relative reduction state of PSII. Using cDNA library screening and data mining, we have identified three different groups of proteins, late embryogenesis abundant (LEA) 3-L1, LEA3-L2, and LEA3-L3, sharing identities with WCS19. These groups represent a new class of proteins in cereals related to group 3 LEA proteins. They share important characteristics such as a sorting signal that is predicted to target them to either the chloroplast or mitochondria and a C-terminal sequence that may be involved in oligomerization. The results of subcellular fractionation, immunolocalization by electron microscopy and the analyses of target sequences within the Wcs19 gene are consistent with the localization of WCS19 within the chloroplast stroma of wheat (Triticum aestivum) and rye (Secale cereale). Western analysis showed that the accumulation of chloroplastic LEA3-L2 proteins is correlated with the capacity of different wheat and rye cultivars to develop freezing tolerance. Arabidopsis was transformed with the Wcs19 gene and the transgenic plants showed a significant increase in their freezing tolerance. This increase was only evident in cold-acclimated plants. The putative function of this protein in the enhancement of freezing tolerance is discussed. PMID:12114590

  18. Abundance of introduced species at home predicts abundance away in herbaceous communities

    USGS Publications Warehouse

    Firn, Jennifer; Moore, Joslin L.; MacDougall, Andrew S.; Borer, Elizabeth T.; Seabloom, Eric W.; HilleRisLambers, Janneke; Harpole, W. Stanley; Cleland, Elsa E.; Brown, Cynthia S.; Knops, Johannes M.H.; Prober, Suzanne M.; Pyke, David A.; Farrell, Kelly A.; Bakker, John D.; O'Halloran, Lydia R.; Adler, Peter B.; Collins, Scott L.; D'Antonio, Carla M.; Crawley, Michael J.; Wolkovich, Elizabeth M.; La Pierre, Kimberly J.; Melbourne, Brett A.; Hautier, Yann; Morgan, John W.; Leakey, Andrew D.B.; Kay, Adam; McCulley, Rebecca; Davies, Kendi F.; Stevens, Carly J.; Chu, Cheng-Jin; Holl, Karen D.; Klein, Julia A.; Fay, Phillip A.; Hagenah, Nicole; Kirkman, Kevin P.; Buckley, Yvonne M.

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.

  19. Abundance Gradients in Clusters of Galaxies

    NASA Astrophysics Data System (ADS)

    Dupke, Renato De Alencar

    This dissertation presents the analysis of spatially resolved ASCA satellite X-ray spectra for four clusters of galaxies (Abell 496, Abell 2199, Abell 3571 and Abell 1060). The abundance distributions of Abell 496, Abell 2199 and Abell 3571 are shown to be centrally enhanced. The distribution of elemental abundance ratios, combined with calculations of supernovae rates, shows that the central abundance enhancement in these galaxy clusters is dominated by supernova, Type 1a iron, while the outer parts are dominated by supernovae Type II iron and the most likely mechanism proposed to produce this central iron is ram-pressure stripping, rather than accumulated stellar mass loss from the central dominant galaxy. At least 50% (by mass) of the iron in the central regions is from supernovae Type Ia, varying slightly from cluster to cluster. Although the analysis of Abell 1060 reveals no significant central abundance enhancement, supernovae Type Ia are shown to contribute significantly to the iron content of the central regions. However, accumulated stellar mass loss from the two central dominant galaxies in this cluster can account for all of the supernovae Type la iron in the central regions. The nickel to iron abundance ratio shows that delayed detonation explosion models for supernovae Type la are inconsistent with the observed abundance ratios in the inner regions of Abell 496, Abell 2199 and Abell 3571. A comparison of the distributions of iron mass and the luminosity of early type galaxies in four clusters, three of them having central abundance enhancements (Virgo, Abell 496 and Centaurus) and one having a flat abundance distribution (Coma), indicates that the iron mass traces the luminosity of early type galaxies in abundance gradient clusters better than in flat abundance clusters. This suggests that abundance gradients can be washed out by cluster mergers.

  20. Hymenoscyphus fraxineus vs. Hymenoscyphus albidus – A comparative light microscopic study on the causal agent of European ash dieback and related foliicolous, stroma-forming species

    PubMed Central

    Baral, Hans-Otto; Bemmann, Martin

    2014-01-01

    Five species of Hymenoscyphus that fruit on black stromatized parts of dead leaves of deciduous trees are presented, giving details on their morphological and ecological characteristics. Several of these species have previously been misplaced in rutstroemiaceous genera because of the presence of a substratal stroma. However, the heteropolar, scutuloid ascospores with an often hook-like lateral protrusion at the rounded apex and the ascus apical ring of the Hymenoscyphus-type represent two reliable morphological characteristics that, together with molecular data, provide clear evidence for their placement in the genus Hymenoscyphus (Helotiaceae). Among the species treated is Hymenoscyphus fraxineus (=Hymenoscyphus pseudoalbidus), the causal agent of the European ash dieback disease. Since 1992 this species started within Europe to replace the rather uncommon Hymenoscyphus albidus, which is likewise confined to leaves of Fraxinus. Hy. fraxineus has been recorded already since 1990 in Eastern Asia (Japan, Korea, northeast of China), where it had been initially misidentified as Lambertella albida (≡Hy. albidus). In these regions, it occurs as a harmless saprotroph on Fraxinus mandshurica and Fraxinus rhynchophylla, suggesting that those populations are native while the European ash dieback disease has a recent Eastern Asiatic origin. The distinctly higher genetic diversity found in Japanese Hy. fraxineus in contrast to European Hy. fraxineus supports this view. Genetic similarities between Japanese Hy. fraxineus and European Hy. albidus suggest that also Hy. albidus might be a descendant of Asian Hy. fraxineus, though having invaded Europe much earlier. However, consistent genetic deviation between European and Asian Hy. fraxineus at two nucleotide positions of the ITS region indicates that the European ash disease originates from a region different from the presently known areas in Eastern Asia. Our results underline the importance of detailed morphological studies

  1. Infrared microspectroscopy identifies biomolecular changes associated with chronic oxidative stress in mammary epithelium and stroma of breast tissues from healthy young women

    PubMed Central

    Patel, Imran I; Shearer, Debra A; Fogarty, Simon W; Fullwood, Nigel J; Quaroni, Luca; Martin, Francis L; Weisz, Judith

    2014-01-01

    Studies of the decades-long latent stages of breast carcinogenesis have been limited to when hyperplastic lesions are already present. Investigations of earlier stages of breast cancer (BC) latency have been stymied by the lack of fiducial biomarkers needed to identify where in histologically normal tissues progression toward a BC might be taking place. Recent evidence suggests that a marker of chronic oxidative stress (OxS), protein adducts of 4-hydroxy-2-nonenal (4HNE), can meet this need. Specifically: (1) 4HNE immunopositive (4HNE+) mammary epithelial (ME) cells were found to be prevalent in normal (reduction mammoplasty) tissues of most women (including many teenagers) studied, representative of those living in the United States’ high risk-posing environment and: (2) marked (>1.5-fold) differences were identified between tissues of healthy young women with many vs. few 4HNE+ ME cells in the relative levels of transcripts for 42 of the 84 OxS-associated genes represented in SABioscience Oxidative-Stress/Oxidative-Defense PCR array. Herein we used synchrotron radiation-based Fourier-transform infrared (SR-FTIR) microspectroscopy to identify molecular changes associated with 4HNE adducts in basal and luminal ME cells in terminal ductal units (TDLU), which are the cells of origin of BC, and associated intralobular and interlobular stroma, known contributors to carcinogenesis. Multivariate analysis-derived wavenumbers differentiated 4HNE+ and 4HNE− cells in each of the anatomical compartments. Specifically, principal component and linear discriminant analyses of mid-infrared spectra obtained from these cells revealed unambiguous, statistically highly significant differences in the “biochemical fingerprint” of 4HNE+ vs. 4HNE− luminal and basal ME cells, as well as between associated intralobular and interlobular stroma. These findings demonstrate further SR-FTIR microspectroscopy’s ability to identify molecular changes associated with altered

  2. Capacity of Lung Stroma to Educate Dendritic Cells Inhibiting Mycobacteria-Specific T-Cell Response Depends upon Genetic Susceptibility to Tuberculosis

    PubMed Central

    Majorov, Konstantin B.; Logunova, Nadezhda N.; Apt, Alexander S.

    2013-01-01

    The balance between activation and inhibition of local immune responses in affected tissues during prolonged chronic infections is important for host protection. There is ample evidence that regulatory, tolerogenic dendritic cells (DC) are developed and present in tissues and inhibit overwhelming inflammatory reactions. Also, it was firmly established that stromal microenvironment of many organs is able to induce development of immature regulatory DC (DCreg), an essential element of a general immune regulatory network. However, direct experimental data demonstrating inhibition of immune responses by stroma-instructed immature DCreg in infectious models are scarce, and virtually nothing is known about functioning of this axis of immunity during tuberculosis (TB) infection. In this study, we demonstrate that lung stromal cells are capable of supporting the development in culture of immature CD11b+CD11clowCD103- DCreg from lineage-negative (lin-) bone marrow precursors. DCreg developed on lung stroma isolated from mice of genetically TB-hyper-susceptible I/St and relatively resistant B6 inbred strains inhibited proliferative response of mycobacteria-specific CD4+ T-cell lines a dose-dependent manner. Importantly, the inhibitory activity of B6 DCreg was substantially higher than that of I/St Dcreg. Moreover, when the donors of stromal cells were chronically infected with virulent mycobacteria, the capacity to instruct inhibitory DCreg was retained in B6, but further diminished in I/St stromal cells. DCreg-provided suppression was mediated by a few soluble mediators, including PGE2, NO and IL-10. The content of CD4+Foxp3+ Treg cells in the mediastinal, lung-draining lymph nodes at the advanced stages of chronic infection did not change in I/St, but increased 2-fold in B6 mice, and lung pathology was much more pronounced in the former mice. Taken together, these data provide genetic evidence that the capacity to maintain populations of regulatory cells during M

  3. Climate and local abundance in freshwater fishes

    PubMed Central

    Knouft, Jason H.; Anthony, Melissa M.

    2016-01-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  4. Climate and local abundance in freshwater fishes.

    PubMed

    Knouft, Jason H; Anthony, Melissa M

    2016-06-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  5. Solar Energetic Particles: Sampling Coronal Abundances

    NASA Astrophysics Data System (ADS)

    Reames, Donald V.

    1998-05-01

    In the large solar energetic particle (SEP) events, coronal mass ejections (CMEs) drive shock waves out through the corona that accelerate elements of the ambient material to MeV energies in a fairly democratic, temperature-independent manner. These events provide the most complete source of information on element abundances in the corona. Relative abundances of 22 elements from H through Zn display the well-known dependence on the first ionization potential (FIP) that distinguishes coronal and photospheric material. For most elements, the main abundance variations depend upon the gyrofrequency, and hence on the charge-to-mass ratio, Q/A, of the ion. Abundance variations in the dominant species, H and He, are not Q/A dependent, presumably because of non-linear wave-particle interactions of H and He during acceleration. Impulsive flares provide a different sample of material that confirms the Ne:Mg:Si and He/C abundances in the corona.

  6. Influence of Coronal Abundance Variations

    NASA Technical Reports Server (NTRS)

    Scargle, Jeffrey D. (Technical Monitor); Kashyap, Vinay

    2005-01-01

    The PI of this project was Jeff Scargle of NASA/Ames. Co-I's were Alma Connors of Eureka Scientific/Wellesley, and myself. Part of the work was subcontracted to Eureka Scientific via SAO, with Vinay Kashyap as PI. This project was originally assigned grant number NCC2-1206, and was later changed to NCC2-1350 for administrative reasons. The goal of the project was to obtain, derive, and develop statistical and data analysis tools that would be of use in the analyses of high-resolution, high-sensitivity data that are becoming available with new instruments. This is envisioned as a cross-disciplinary effort with a number of "collaborators" including some at SA0 (Aneta Siemiginowska, Peter Freeman) and at the Harvard Statistics department (David van Dyk, Rostislav Protassov, Xiao-li Meng, Epaminondas Sourlas, et al). We have developed a new tool to reliably measure the metallicities of thermal plasma. It is unfeasible to obtain high-resolution grating spectra for most stars, and one must make the best possible determination based on lower-resolution, CCD-type spectra. It has been noticed that most analyses of such spectra have resulted in measured metallicities that were significantly lower than when compared with analyses of high- resolution grating data where available (see, e.g., Brickhouse et al., 2000, ApJ 530,387). Such results have led to the proposal of the existence of so-called Metal Abundance Deficient, or "MAD" stars (e.g., Drake, J.J., 1996, Cool Stars 9, ASP Conf.Ser. 109, 203). We however find that much of these analyses may be systematically underestimating the metallicities, and using a newly developed method to correctly treat the low-counts regime at the high-energy tail of the stellar spectra (van Dyk et al. 2001, ApJ 548,224), have found that the metallicities of these stars are generally comparable to their photospheric values. The results were reported at the AAS (Sourlas, Yu, van Dyk, Kashyap, and Drake, 2000, BAAS 196, v32, #54.02), and at the

  7. Stroma-Derived Connective Tissue Growth Factor Maintains Cell Cycle Progression and Repopulation Activity of Hematopoietic Stem Cells In Vitro

    PubMed Central

    Istvánffy, Rouzanna; Vilne, Baiba; Schreck, Christina; Ruf, Franziska; Pagel, Charlotta; Grziwok, Sandra; Henkel, Lynette; Prazeres da Costa, Olivia; Berndt, Johannes; Stümpflen, Volker; Götze, Katharina S.; Schiemann, Matthias; Peschel, Christian; Mewes, Hans-Werner; Oostendorp, Robert A.J.

    2015-01-01

    Summary Hematopoietic stem cells (HSCs) are preserved in co-cultures with UG26-1B6 stromal cells or their conditioned medium. We performed a genome-wide study of gene expression changes of UG26-1B6 stromal cells in contact with Lineage− SCA-1+ KIT+ (LSK) cells. This analysis identified connective tissue growth factor (CTGF) to be upregulated in response to LSK cells. We found that co-culture of HSCs on CTGF knockdown stroma (shCtgf) shows impaired engraftment and long-term quality. Further experiments demonstrated that CD34− CD48− CD150+ LSK (CD34− SLAM) cell numbers from shCtgf co-cultures increase in G0 and senescence and show delayed time to first cell division. To understand this observation, a CTGF signaling network model was assembled, which was experimentally validated. In co-culture experiments of CD34− SLAM cells with shCtgf stromal cells, we found that SMAD2/3-dependent signaling was activated, with increasing p27Kip1 expression and downregulating cyclin D1. Our data support the view that LSK cells modulate gene expression in the niche to maintain repopulating HSC activity. PMID:26527384

  8. Constitutive activation of Beta-catenin in uterine stroma and smooth muscle leads to the development of mesenchymal tumors in mice.

    PubMed

    Tanwar, Pradeep S; Lee, Ho-Joon; Zhang, LiHua; Zukerberg, Lawrence R; Taketo, Makoto M; Rueda, Bo R; Teixeira, Jose M

    2009-09-01

    Leiomyomas and other mesenchymally derived tumors are the most common neoplasms of the female reproductive tract. Presently, very little is known about the etiology and progression of these tumors, which are the primary indication for hysterectomies. Dysregulated WNT signaling through beta-catenin is a well-established mechanism for tumorigenesis. We have developed a mouse model that expresses constitutively activated beta-catenin in uterine mesenchyme driven by the expression of Cre recombinase knocked into the Müllerian-inhibiting substance type II receptor promoter locus to investigate its effects on uterine endometrial stroma and myometrium. These mice show myometrial hyperplasia and develop mesenchymal tumors with 100% penetrance that exhibit histological and molecular characteristics of human leiomyomas and endometrial stromal sarcomas. By immunohistochemistry, we also show that both transforming growth factor beta and the mammalian target of rapamycin are induced by constitutive activation of beta-catenin. The prevalence of the tumors was greater in multiparous mice, suggesting that their development may be a hormonally driven process or that changes in uterine morphology during pregnancy and after parturition induce injury and repair mechanisms that stimulate tumorigenesis from stem/progenitor cells, which normally do not express constitutively activated beta-catenin. Additionally, adenomyosis and endometrial gland hyperplasia were occasionally observed in some mice. These results show evidence suggesting that dysregulated, stromal, and myometrial WNT/beta-catenin signaling has pleiotropic effects on uterine function and tumorigenesis. PMID:19403928

  9. Constitutive Activation of Beta-Catenin in Uterine Stroma and Smooth Muscle Leads to the Development of Mesenchymal Tumors in Mice1

    PubMed Central

    Tanwar, Pradeep S.; Lee, Ho-Joon; Zhang, LiHua; Zukerberg, Lawrence R.; Taketo, Makoto M.; Rueda, Bo R.; Teixeira, Jose M.

    2009-01-01

    Leiomyomas and other mesenchymally derived tumors are the most common neoplasms of the female reproductive tract. Presently, very little is known about the etiology and progression of these tumors, which are the primary indication for hysterectomies. Dysregulated WNT signaling through beta-catenin is a well-established mechanism for tumorigenesis. We have developed a mouse model that expresses constitutively activated beta-catenin in uterine mesenchyme driven by the expression of Cre recombinase knocked into the Müllerian-inhibiting substance type II receptor promoter locus to investigate its effects on uterine endometrial stroma and myometrium. These mice show myometrial hyperplasia and develop mesenchymal tumors with 100% penetrance that exhibit histological and molecular characteristics of human leiomyomas and endometrial stromal sarcomas. By immunohistochemistry, we also show that both transforming growth factor beta and the mammalian target of rapamycin are induced by constitutive activation of beta-catenin. The prevalence of the tumors was greater in multiparous mice, suggesting that their development may be a hormonally driven process or that changes in uterine morphology during pregnancy and after parturition induce injury and repair mechanisms that stimulate tumorigenesis from stem/progenitor cells, which normally do not express constitutively activated beta-catenin. Additionally, adenomyosis and endometrial gland hyperplasia were occasionally observed in some mice. These results show evidence suggesting that dysregulated, stromal, and myometrial WNT/beta-catenin signaling has pleiotropic effects on uterine function and tumorigenesis. PMID:19403928

  10. Tissue-specific patterns of gene expression in the epithelium and stroma of normal colon in healthy individuals in an aspirin intervention trial.

    PubMed

    Thomas, Sushma S; Makar, Karen W; Li, Lin; Zheng, Yingye; Yang, Peiying; Levy, Lisa; Rudolph, Rebecca Y; Lampe, Paul D; Yan, Min; Markowitz, Sanford D; Bigler, Jeannette; Lampe, Johanna W; Potter, John D

    2015-12-01

    Regular aspirin use reduces colon adenoma and carcinoma incidence. UDP-glucuronosyltransferases (UGT) are involved in aspirin metabolism and clearance, and variant alleles in UGT1A6 have been shown to alter salicylic acid metabolism and risk of colon neoplasia. In a randomized, cross-over, placebo-controlled trial of 44 healthy men and women, homozygous for UGT1A6*1 or UGT1A6*2, we explored differences between global epithelial and stromal expression, using Affymetrix U133 + 2.0 microarrays and tested effects of 60-day aspirin supplementation (325 mg/d) on epithelial and stromal gene expression and colon prostaglandin E2 (PGE2) levels. We conducted a comprehensive study of differential gene expression between normal human colonic epithelium and stroma from healthy individuals. Although no statistically significant differences in gene expression were observed in response to aspirin or UGT1A6 genotype, we have identified the genes uniquely and reproducibly expressed in each tissue type and have analyzed the biologic processes they represent. Here we describe in detail how the data, deposited in the Gene Expression Omnibus (GEO) - accession number GSE71571 - was generated including the basic analysis as contained in the manuscript published in BMC Medical Genetics with the PMID 25927723 (Thomas et al., 2015 [9]). PMID:26697360

  11. On protein abundance distributions in complex mixtures

    PubMed Central

    2013-01-01

    Mass spectrometry, an analytical technique that measures the mass-to-charge ratio of ionized atoms or molecules, dates back more than 100 years, and has both qualitative and quantitative uses for determining chemical and structural information. Quantitative proteomic mass spectrometry on biological samples focuses on identifying the proteins present in the samples, and establishing the relative abundances of those proteins. Such protein inventories create the opportunity to discover novel biomarkers and disease targets. We have previously introduced a normalized, label-free method for quantification of protein abundances under a shotgun proteomics platform (Griffin et al., 2010). The introduction of this method for quantifying and comparing protein levels leads naturally to the issue of modeling protein abundances in individual samples. We here report that protein abundance levels from two recent proteomics experiments conducted by the authors can be adequately represented by Sichel distributions. Mathematically, Sichel distributions are mixtures of Poisson distributions with a rather complex mixing distribution, and have been previously and successfully applied to linguistics and species abundance data. The Sichel model can provide a direct measure of the heterogeneity of protein abundances, and can reveal protein abundance differences that simpler models fail to show. PMID:23360617

  12. Silicon abundances in population I giants

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika

    1992-01-01

    Silicon to carbon abundance ratios for population I giants were determined from emission lines originating in the transition layers between stellar chromospheres and coronae. For effective temperatures larger than 6200 K we find a group of stars with increased silicon to carbon but normal nitrogen to carbon abundance ratios. These stars are presumably descendents from Ap stars with increased surface silicon to carbon abundance ratios. For G stars this anomaly disappears as is to be expected due to the increased depth of the convection zone and therefore deeper mixing which dilutes the surface overabundances. The disappearance of the abundance anomalies proves that the anomalous abundances observed for the F giants are indeed only a surface phenomenon. It also proves that the same holds for their progenitors, the Ap and Am stars, as has been generally believed. Unexplained is the increased silicon to carbon abundance ratio observed for several stars cooler than 5100 L. RS CVn and related stars do not show this increased abundance ratio. There are also some giants which appear to be enriched in carbon, perhaps due to a helium flash with some mixing if the star is a clump star.

  13. Monitoring Butterfly Abundance: Beyond Pollard Walks

    PubMed Central

    Pellet, Jérôme; Bried, Jason T.; Parietti, David; Gander, Antoine; Heer, Patrick O.; Cherix, Daniel; Arlettaz, Raphaël

    2012-01-01

    Most butterfly monitoring protocols rely on counts along transects (Pollard walks) to generate species abundance indices and track population trends. It is still too often ignored that a population count results from two processes: the biological process (true abundance) and the statistical process (our ability to properly quantify abundance). Because individual detectability tends to vary in space (e.g., among sites) and time (e.g., among years), it remains unclear whether index counts truly reflect population sizes and trends. This study compares capture-mark-recapture (absolute abundance) and count-index (relative abundance) monitoring methods in three species (Maculinea nausithous and Iolana iolas: Lycaenidae; Minois dryas: Satyridae) in contrasted habitat types. We demonstrate that intraspecific variability in individual detectability under standard monitoring conditions is probably the rule rather than the exception, which questions the reliability of count-based indices to estimate and compare specific population abundance. Our results suggest that the accuracy of count-based methods depends heavily on the ecology and behavior of the target species, as well as on the type of habitat in which surveys take place. Monitoring programs designed to assess the abundance and trends in butterfly populations should incorporate a measure of detectability. We discuss the relative advantages and inconveniences of current monitoring methods and analytical approaches with respect to the characteristics of the species under scrutiny and resources availability. PMID:22859980

  14. Predicting the dynamics of protein abundance.

    PubMed

    Mehdi, Ahmed M; Patrick, Ralph; Bailey, Timothy L; Bodén, Mikael

    2014-05-01

    Protein synthesis is finely regulated across all organisms, from bacteria to humans, and its integrity underpins many important processes. Emerging evidence suggests that the dynamic range of protein abundance is greater than that observed at the transcript level. Technological breakthroughs now mean that sequencing-based measurement of mRNA levels is routine, but protocols for measuring protein abundance remain both complex and expensive. This paper introduces a Bayesian network that integrates transcriptomic and proteomic data to predict protein abundance and to model the effects of its determinants. We aim to use this model to follow a molecular response over time, from condition-specific data, in order to understand adaptation during processes such as the cell cycle. With microarray data now available for many conditions, the general utility of a protein abundance predictor is broad. Whereas most quantitative proteomics studies have focused on higher organisms, we developed a predictive model of protein abundance for both Saccharomyces cerevisiae and Schizosaccharomyces pombe to explore the latitude at the protein level. Our predictor primarily relies on mRNA level, mRNA-protein interaction, mRNA folding energy and half-life, and tRNA adaptation. The combination of key features, allowing for the low certainty and uneven coverage of experimental observations, gives comparatively minor but robust prediction accuracy. The model substantially improved the analysis of protein regulation during the cell cycle: predicted protein abundance identified twice as many cell-cycle-associated proteins as experimental mRNA levels. Predicted protein abundance was more dynamic than observed mRNA expression, agreeing with experimental protein abundance from a human cell line. We illustrate how the same model can be used to predict the folding energy of mRNA when protein abundance is available, lending credence to the emerging view that mRNA folding affects translation efficiency

  15. Predicting the Dynamics of Protein Abundance

    PubMed Central

    Mehdi, Ahmed M.; Patrick, Ralph; Bailey, Timothy L.; Bodén, Mikael

    2014-01-01

    Protein synthesis is finely regulated across all organisms, from bacteria to humans, and its integrity underpins many important processes. Emerging evidence suggests that the dynamic range of protein abundance is greater than that observed at the transcript level. Technological breakthroughs now mean that sequencing-based measurement of mRNA levels is routine, but protocols for measuring protein abundance remain both complex and expensive. This paper introduces a Bayesian network that integrates transcriptomic and proteomic data to predict protein abundance and to model the effects of its determinants. We aim to use this model to follow a molecular response over time, from condition-specific data, in order to understand adaptation during processes such as the cell cycle. With microarray data now available for many conditions, the general utility of a protein abundance predictor is broad. Whereas most quantitative proteomics studies have focused on higher organisms, we developed a predictive model of protein abundance for both Saccharomyces cerevisiae and Schizosaccharomyces pombe to explore the latitude at the protein level. Our predictor primarily relies on mRNA level, mRNA–protein interaction, mRNA folding energy and half-life, and tRNA adaptation. The combination of key features, allowing for the low certainty and uneven coverage of experimental observations, gives comparatively minor but robust prediction accuracy. The model substantially improved the analysis of protein regulation during the cell cycle: predicted protein abundance identified twice as many cell-cycle-associated proteins as experimental mRNA levels. Predicted protein abundance was more dynamic than observed mRNA expression, agreeing with experimental protein abundance from a human cell line. We illustrate how the same model can be used to predict the folding energy of mRNA when protein abundance is available, lending credence to the emerging view that mRNA folding affects translation

  16. Solar abundances and 3D model atmospheres

    NASA Astrophysics Data System (ADS)

    Ludwig, Hans-Günter; Caffau, Elisabetta; Steffen, Matthias; Bonifacio, Piercarlo; Freytag, Bernd; Cayrel, Roger

    2010-03-01

    We present solar photospheric abundances for 12 elements from optical and near-infrared spectroscopy. The abundance analysis was conducted employing 3D hydrodynamical (CO5BOLD) as well as standard 1D hydrostatic model atmospheres. We compare our results to others with emphasis on discrepancies and still lingering problems, in particular exemplified by the pivotal abundance of oxygen. We argue that the thermal structure of the lower solar photosphere is very well represented by our 3D model. We obtain an excellent match of the observed center-to-limb variation of the line-blanketed continuum intensity, also at wavelengths shortward of the Balmer jump.

  17. Interstellar Abundances Toward X Per, Revisited

    NASA Technical Reports Server (NTRS)

    Valencic, Lynne A.; Smith, Randall K.

    2012-01-01

    The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to measure elemental abundances in the local ISM. We examine absorption features of O, Mg, and Si along this line of sight using spectra from the Chandra Observatory's LETG/ACIS-S and XMM-Newton's RGS instruments. In general, we find that the abundances and their ratios are similar to those of young F and G stars and the most recent solar values. We compare our results with abundances required by dust grain models.

  18. Interstellar Abundances Toward X Per, Revisited

    NASA Technical Reports Server (NTRS)

    Valencic, Lynne A.; Smith, Randall K.

    2014-01-01

    The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to measure elemental abundances in the local ISM. We examine absorption features of 0, Mg, and Si along this line of sight using spectra from the Chandra Observatory's LETG/ ACIS-S and XMM-Newton's RGS instruments. In general, we find that the abundances and their ratios are similar to those of young F and G stars and the most recent solar values. We compare our results with abundances required by dust grain models.

  19. Abundance variations in solar energetic particles

    NASA Technical Reports Server (NTRS)

    Cane, H. V.; Reames, D. V.; Von Rosenvinge, T. T.

    1991-01-01

    Abundance variations are examined in a large number of events including smaller nonimpulsive events not previously considered. Whereas a comparison at equal energy per nucleon is appropriate for heavy ions this is not the case when including H. The best representation is either in terms of rigidity or energy per charge depending on the type of event under consideration. For the majority of large events, where particles are primarily accelerated at interplanetary shocks, if abundances relative to H are evaluated at equal energy per charge then abundance ratios are compatible with solar wind values and spectral shapes agree. Furthermore the behavior of H is then compatible with that of other high FIP elements.

  20. The state of the photosynthetic apparatus in leaves as analyzed by rapid gas exchange and optical methods: the pH of the chloroplast stroma and activation of enzymes in vivo.

    PubMed

    Laisk, A; Oja, V; Kiirats, O; Raschke, K; Heber, U

    1989-03-01

    The exchange of CO2 and O2 was measured in leaves using specially constructed equipment capable of responding to rapid transients. Optical measurements provided information on cytochrome f and P 700 oxidation in the light. The following results were obtained: i) The solubilization of CO2 was used to calculate the pH of the chloroplast stroma in darkened leaves. Values ranged from pH 7.8 to pH 8.0 in different C3 plants. ii) Illumination of predarkened leaves of Helianthus annuus L. resulted in three distinct phases of O2 evolution that illustrate the complexity of light activation of the photosynthetic apparatus. A first burst of O2 is attributed to the reduction of electron carriers of the electron-transport chain. While plastoquinone was reduced, cytochrome f was oxidized. Appreciable oxidation of P 700 became possible only during the second O2 burst, which indicates the reduction of the phosphoglycerate pool. Extensive oxidation required the opening of an electron gate on the reducing side of photosystem I. The subsequent slow rise in O2 evolution towards a steady state reflects activation of the Calvin cycle and is the result of CO2 assimilation. iii) Light-dependent CO2 uptake by predarkened leaves occurred in four phases, three of them based on pH changes in the chloroplast stroma. Initial CO2 uptake was small and probably caused by protonation of reduced plastoquinone. In the second phase, which coincided with the reduction of the pool of phosphoglycerate, the initial alkalization of the chloroplast stroma was substantially increased. In the third phase, the stroma alkalization decreased, and the fourth phase was dominated by CO2 assimilation. iv) Respiratory CO2 production was partially suppressed in the light during the second phase of O2 evolution while phosphoglycerate was being reduced. PMID:24212428

  1. Bone marrow stroma-induced resistance of chronic lymphocytic leukemia cells to arsenic trioxide involves Mcl-1 upregulation and is overcome by inhibiting the PI3Kδ or PKCβ signaling pathways.

    PubMed

    Amigo-Jiménez, Irene; Bailón, Elvira; Aguilera-Montilla, Noemí; Terol, María José; García-Marco, José A; García-Pardo, Angeles

    2015-12-29

    CLL remains an incurable disease in spite of the many new compounds being studied. Arsenic trioxide (ATO) induces apoptosis in all CLL cell types and could constitute an efficient therapy. To further explore this, we have studied the influence of stromal cells, key components of the CLL microenvironment, on the response of CLL cells to ATO. Bone marrow stromal cells induced CLL cell resistance to 2 μM ATO and led to activation of Lyn, ERK, PI3K and PKC, as well as NF-κB and STAT3. Mcl-1, Bcl-xL, and Bfl-1 were also upregulated after the co-culture. Inhibition experiments indicated that PI3K and PKC were involved in the resistance to ATO induced by stroma. Moreover, idelalisib and sotrastaurin, specific inhibitors for PI3Kδ and PKCβ, respectively, inhibited Akt phosphorylation, NF-κB/STAT3 activation and Mcl-1 upregulation, and rendered cells sensitive to ATO. Mcl-1 was central to the mechanism of resistance to ATO, since: 1) Mcl-1 levels correlated with the CLL cell response to ATO, and 2) blocking Mcl-1 expression or function with specific siRNAs or inhibitors overcame the protecting effect of stroma. We have therefore identified the mechanism involved in the CLL cell resistance to ATO induced by bone marrow stroma and show that idelalisib or sotrastaurin block this mechanism and restore sensibility to ATO. Combination of ATO with these inhibitors may thus constitute an efficient treatment for CLL. PMID:26540567

  2. Bone marrow stroma-induced resistance of chronic lymphocytic leukemia cells to arsenic trioxide involves Mcl-1 upregulation and is overcome by inhibiting the PI3Kδ or PKCβ signaling pathways

    PubMed Central

    Amigo-Jiménez, Irene; Bailón, Elvira; Aguilera-Montilla, Noemí; Terol, María José; García-Marco, José A.; García-Pardo, Angeles

    2015-01-01

    CLL remains an incurable disease in spite of the many new compounds being studied. Arsenic trioxide (ATO) induces apoptosis in all CLL cell types and could constitute an efficient therapy. To further explore this, we have studied the influence of stromal cells, key components of the CLL microenvironment, on the response of CLL cells to ATO. Bone marrow stromal cells induced CLL cell resistance to 2 μM ATO and led to activation of Lyn, ERK, PI3K and PKC, as well as NF-κB and STAT3. Mcl-1, Bcl-xL, and Bfl-1 were also upregulated after the co-culture. Inhibition experiments indicated that PI3K and PKC were involved in the resistance to ATO induced by stroma. Moreover, idelalisib and sotrastaurin, specific inhibitors for PI3Kδ and PKCβ, respectively, inhibited Akt phosphorylation, NF-κB/STAT3 activation and Mcl-1 upregulation, and rendered cells sensitive to ATO. Mcl-1 was central to the mechanism of resistance to ATO, since: 1) Mcl-1 levels correlated with the CLL cell response to ATO, and 2) blocking Mcl-1 expression or function with specific siRNAs or inhibitors overcame the protecting effect of stroma. We have therefore identified the mechanism involved in the CLL cell resistance to ATO induced by bone marrow stroma and show that idelalisib or sotrastaurin block this mechanism and restore sensibility to ATO. Combination of ATO with these inhibitors may thus constitute an efficient treatment for CLL. PMID:26540567

  3. The solar system abundance of tin

    NASA Astrophysics Data System (ADS)

    Loss, R. D.; Rosman, K. K. R.; de Laeter, J. R.

    1989-04-01

    The elemental abundance of tin has been determined by the mass spectrometric isotope dilution technique for four carbonaceous chondrites, including the Cl chondrites Orgueil and Ivuna. A solar system abundance of 3.98 (normalized to Si = 10 to the 6th atoms) can be derived from these data, which is in excellent agreement with the presently accepted value. Recently, a theoretical value of 2.82 + or - 0.21 (Si = 10 to the 6th atoms) has been proposed for the abundance of tin based on an s-process nucleosynthesis model. This value is 26 percent lower than the presently accepted solar system abundance. The present data confirm the higher value for tin and indicate that a reexamination of the assumptions on which the nucleosynthetic value is based is required.

  4. Coronal abundances determined from energetic particles

    NASA Technical Reports Server (NTRS)

    Reames, D. V.

    1995-01-01

    Solar energetic particles (SEPs) provide a measurement of coronal element abundances that is highly independent of the ionization states and temperature of the ions in the source plasma. The most complete measurements come from large 'gradual' events where ambient coronal plasma is swept up by the expanding shock wave from a coronal mass ejection. Particles from 'impulsive' flares have a pattern of acceleration-induced enhancements superimposed on the coronal abundances. Particles accelerated from high-speed solar wind streams at corotating shocks show a different abundance pattern corresponding to material from coronal holes. Large variations in He/O in coronal material are seen for both gradual and impulsive-flare events but other abundance ratios, such as Mg/Ne, are remarkably constant. SEP measurements now include hundreds of events spanning 15 years of high-quality measurement.

  5. SAGA: Stellar Abundances for Galatic Archeology

    NASA Astrophysics Data System (ADS)

    Suda, T.

    A tutorial for the Stellar Abundances for Galactic Archaeology (SAGA) database is presented. This paper describes the outline of the database, reports the current status of the data compilation and known problems, and presents plans for future updates and extensions.

  6. GALA: Stellar atmospheric parameters and chemical abundances

    NASA Astrophysics Data System (ADS)

    Mucciarelli, A.; Pancino, E.; Lovisi, L.; Ferraro, F. R.; Lapenna, E.

    2013-02-01

    GALA is a freely distributed Fortran code to derive the atmospheric parameters (temperature, gravity, microturbulent velocity and overall metallicity) and abundances for individual species of stellar spectra using the classical method based on the equivalent widths of metallic lines. The abundances of individual spectral lines are derived by using the WIDTH9 code developed by R. L. Kurucz. GALA is designed to obtain the best model atmosphere, by optimizing temperature, surface gravity, microturbulent velocity and metallicity, after rejecting the discrepant lines. Finally, it computes accurate internal errors for each atmospheric parameter and abundance. The code obtains chemical abundances and atmospheric parameters for large stellar samples quickly, thus making GALA an useful tool in the epoch of the multi-object spectrographs and large surveys.

  7. Abundances of Elements in Stellar Coronae

    NASA Technical Reports Server (NTRS)

    Drake, Jeremy

    1998-01-01

    Interest in stellar coronal abundances was piqued several years ago by the launch of satellites that were able to study the compositions of coronae on stars other than the sun. Motivated by the possibility that other stellar coronae might share the First Ionization Potential (FIP) Effect solar abundance anomaly, we have in recent years been attempting to determine coronal element abundances in other stars. I will review these results, together with similar results reported in the literature, from a critical perspective of understanding the true uncertainties involved in the measurements. The importance of element abundances for coronal physics will be highlighted, and it will be shown that the differences in the chemical compositions of active stars allow us to draw new conclusions regarding the nature of stellar coronae and coronal heating.

  8. The abundant elements in interstellar dust

    NASA Technical Reports Server (NTRS)

    Sofia, Ulysses J.; Cardelli, Jason A.; Savage, Blair D.

    1994-01-01

    We explore the incorporation of the cosmically abundant species O, C, N, Mg, Si, Fe, and S into interstellar dust. Column densities based on Goddard High Resolution Spectrograph 3.5 km/s resolution measurements from the literature for eight individual absorbing regions toward five lines of sight are used. Corrections are applied as needed in order to account for recent improvements in oscillator strengths. In order to acquire the most accurate column densities, and check on the accuracy of the oscillator strengths, we compare column densities based on the very strong Lorentzian damped lines of C II, O I, N I, and Mg II with results for the weak lines of these species, and confirm the previously determined f-values for O I lambda 1335, C II lambda 2325, and N I lambda lambda 1159, 1160. New empirical f-values of 1.25 x 10(exp -3) and 6.25 x 10(exp -4), respectively, are derived for the Mg II weak doublet at 1239 and 1240 A. Assuming a cosmic reference abundance based on solar and B star values, we derive depletions and dust-phase abundances which suggest that more than 70% of the available Mg and Fe is incorporated into dust-grain cores, whereas only 35% of the silicon is. This implies that oxides are important constituents of the grain core population. Mg and Fe atoms are mantled onto grain cores in a ratio of 1.8 to 1, whereas approximately 4.0 Si atoms are in the mantle per Fe atom. Since Si is not expected to accrete onto silicate or graphite grains, other grain cores, perhaps oxides and/or metallic Fe, may provide mantling sites for this species. The abundances of Fe and Mg in mantles would imply that graphite grains must have a substantial coating unless oxides provide significant mantling sites for these species. The abundance of O and N in the dust phase as implied by the solar reference abundance values are difficult to reconcile with the fact that these elements are not expected to participate in mantle formation, and the 3.1 micrometer H2O ice feature is

  9. Elemental abundance determinations for meteors by spectroscopy.

    NASA Technical Reports Server (NTRS)

    Harvey, G. A.

    1973-01-01

    Relative elemental abundance determinations for meteors by spectroscopy are discussed. Relative abundances of spectroscopically accessible elements of four major shower meteors and one sporadic meteor are presented. A sporadic meteor with dominant sodium radiation and an iron-deficient sporadic meteor are analyzed. Empirical and theoretical tests for self-absorption in optical meteor plasmas have been conducted. Both ionization and incomplete dissociation are found to severely deplete certain neutral atoms from meteor plasmas.

  10. Species Abundance Patterns in Complex Evolutionary Dynamics

    NASA Astrophysics Data System (ADS)

    Tokita, Kei

    2004-10-01

    An analytic theory of species abundance patterns (SAPs) in biological networks is presented. The theory is based on multispecies replicator dynamics equivalent to the Lotka-Volterra equation, with diverse interspecies interactions. Various SAPs observed in nature are derived from a single parameter. The abundance distribution is formed like a widely observed left-skewed lognormal distribution. As the model has a general form, the result can be applied to similar patterns in other complex biological networks, e.g., gene expression.

  11. Coronae of Stars with Supersolar Elemental Abundances

    NASA Technical Reports Server (NTRS)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.

    2015-01-01

    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, iota Hor, HR 7291, tau Boo, and alpha Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and tau Boo no FIP effect is present, while iota Hor, HR 7291, and alpha Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  12. Coronae of stars with supersolar elemental abundances

    NASA Astrophysics Data System (ADS)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.

    2015-05-01

    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, ι Hor, HR 7291, τ Boo, and α Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and τ Boo no FIP effect is present, while ι Hor, HR 7291, and α Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  13. Solar Models with New Low Metal Abundances

    NASA Astrophysics Data System (ADS)

    Yang, Wuming

    2016-04-01

    In the past decade, the photospheric abundances of the Sun had been revised several times by many observers. The standard solar models constructed with the new low-metal abundances disagree with helioseismic results and detected neutrino fluxes. The solar model problem has puzzled some stellar physicists for more than 10 years. Rotation, enhanced diffusion, convection overshoot, and magnetic fields are used to reconcile the new abundances with helioseismology. The too low helium subsurface abundance in enhanced diffusion models can be improved by the mixing caused by rotation and magnetic fields. The problem of the depth of the convective zone in rotating models can be resolved by convection overshoot. Consequently, the Asplund–Grevesse–Sauval rotation model including overshooting (AGSR) reproduces the seismically inferred sound-speed and density profiles and the convection zone depth as well as the Grevesse & Sauval model computed before. But this model fails to reproduce the surface helium abundance, which is 0.2393 (2.6σ away from the seismic value), and neutrino fluxes. The magnetic model called AGSM keeps the agreement of the AGSR and improves the prediction of the surface helium abundance. The observed separation ratios r02 and r13 are reasonably reproduced by AGSM. Moreover, neutrino fluxes calculated by this model are not far from the detected neutrino fluxes and the predictions of previous works.

  14. Report on carbon and nitrogen abundance studies

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika

    1991-01-01

    The aim of the proposal was to determine the nitrogen to carbon abundance ratios from transition layer lines in stars with different T(sub eff) and luminosities. The equations which give the surface emission line fluxes and the measured ratio of the NV to CIV emission line fluxes are presented and explained. The abundance results are compared with those of photospheric abundance studies for stars in common with the photospheric investigations. The results show that the analyses are at least as accurate as the photospheric determinations. These studies can be extended to F and early G stars for which photospheric abundance determinations for giants are hard to do because molecular bands become too weak. The abundance determination in the context of stellar evolution is addressed. The N/C abundance ratio increases steeply at the point of evolution for which the convection zone reaches deepest. Looking at the evolution of the rotation velocities v sin i, a steep decrease in v sin i is related to the increasing depth of the convection zone. It is concluded that the decrease in v sin i for T(sub eff) less than or approximately = 5800 K is most probably due to the rearrangement of the angular momentum in the stars due to deep convective mixing. It appears that the convection zone is rotating with nearly depth independent angular momentum. Other research results and ongoing projects are discussed.

  15. Zinc Abundances in Galactic Bulge Stars

    NASA Astrophysics Data System (ADS)

    Silveira, C. R.; Barbuy, B.

    2014-10-01

    Zinc is overabundant in metal-poor stars (Cayrel et al. 2004), being partially produced by neutron addition. It decreases with increasing metallicity, similarly to alpha-elements. In order to trace its abundance, the derivation of Zn abundance in different stellar populations, and varying metallicities, helps understanding its nucleosynthesis processes. Zn is also the main element of reference to derive the metallicity from absorption lines in quasars (QSOs), which allows to compare their evolution as a function of redshift and metallicity in metal-poor stars. In the present work, we derive Zn abundances for a sample of 56 bulge field stars, observed at high resolution with the FLAMES-UVES spectrograph. The mean wavelength coverage is 4800-6800 Å, at a resolution R ˜ 45000. The atmospheric parameters effective temperature, gravity and metallicity were derived in Zoccali et al. (2008) and Hill et al. (2011). Recently we have analysed the manganese abundances of this sample (Barbuy et al. 2013). To compute the Zn abundances we use spectrum synthesis, for the lines ZnI 4810.53 and 6362.34 Å. The analysis of our data shows that the abundance of [Zn/Fe] decreases with increasing metallicity, in agreement with the data obtained from the literature. The details of Zn behaviour for the metal-rich bulge stars of the present work are under analysis.

  16. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  17. Abundances in 8 QSO Absorption Line Systems

    NASA Astrophysics Data System (ADS)

    Lauroesch, James Thomas

    1995-01-01

    An analysis is given of high resolution observations of metal-absorption line systems in the spectra of 4 QSOs made with the echelle spectrograph on the Mayall 4-meter telescope at Kitt Peak National Observatory. High spectral -resolution (9 to 18 km cdot s^{ -1}) observations were obtained for the QSOs S5 0014 + 813, H 0913 + 072, B2 1225 + 317, and HS 1946 + 7658; column densities were derived for the heavy element line systems. Abundances and/or abundance ratios have been determined for 8 systems and a variety of H I column densities in the redshift range 1-3.4 are probed. The systems studies are generally relatively poor in heavy elements, and appear to be similar in heavy element abundances to the gas out of which the Galactic halo stars of similar metallicity formed. Indications of the halo star-abundance sample include the observed ratios of (N/Si), (Al/Si), and (Mn/Fe). The existence of associated H II regions is inferred for a number of damped systems, and it is suggested that the possibly significant amount of gas in H II regions in damped Lyman-alpha systems can be constrained by the comparison of the column densities of O I, N I, N II, Si II, and S II in these systems. The ratio of N(Al II)/N(Al III) is shown to be a poor indicator of the amount of ionized gas in some cases. The abundances of Si as determined from N(Si II)/N(H I) suggest that there is a relatively rapid decrease in abundances in these systems at z _sp{ ~}> 2. Such a decrease in abundances is what would be expected if the galactic (thin) disks did not form before redshifts of z {~} 2. The use of Si II is important, since the weakness of the Zn II lines at low abundances (due to the low relative abundance of Zn compared to elements such as Si) will result in few detections, and in upper limits that are difficult to interpret. The observed drop in abundances is consistent with the decrease in number of heavy-element absorption systems at high redshifts, a result that is found in

  18. Mesenchymal stroma cells trigger early attraction of M1 macrophages and endothelial cells into fibrin hydrogels, stimulating long bone healing without long-term engraftment.

    PubMed

    Seebach, Elisabeth; Freischmidt, Holger; Holschbach, Jeannine; Fellenberg, Jörg; Richter, Wiltrud

    2014-11-01

    Implantation of mesenchymal stroma cells (MSCs) is an attractive approach to stimulate closure of large bone defects but an optimal carrier has yet to be defined. MSCs may display trophic and/or immunomodulatory features or stimulate bone healing by their osteogenic activity. The aim of this study was to unravel whether fibrin hydrogel supports early actions of implanted MSCs, such as host cell recruitment, immunomodulation and tissue regeneration, in long bone defects. Female rats received cell-free fibrin or male MSCs embedded in a fibrin carrier into plate-stabilized femoral bone defects. Removed callus was analyzed for host cell invasion (day 6), local cytokine expression (days 3 and 6) and persistence of male MSCs (days 3, 6, 14 and 28). Fibrin-MSC composites triggered fast attraction of host cells into the hydrogel while cell-free fibrin implants were not invaded. A migration front dominated by M1 macrophages and endothelial progenitor cells formed while M2 macrophages remained sparse. Only MSC-seeded fibrin hydrogel stimulated early tissue maturation and primitive vessel formation at day 6 in line with significantly higher VEGF mRNA levels recorded at day 3. Local TNF-α, IL-1β and IL-10 expression indicated a balanced immune cell activity independent of MSC implantation. Implanted MSCs persisted until day 14 but not day 28. Our results demonstrate that fibrin hydrogel is an attractive carrier for MSC implantation into long bone defects, supporting host cell attraction and pro-angiogenic activity. By this angiogenesis, implant integration and tissue maturation was stimulated in long bone healing independent of long-term engraftment of implanted MSCs. PMID:25058402

  19. The assessment of cryopreservation conditions for human umbilical cord stroma-derived mesenchymal stem cells towards a potential use for stem cell banking.

    PubMed

    Balci, Deniz; Can, Alp

    2013-01-01

    Human umbilical cord stroma-derived mesenchymal stem cells (hUCS-MSCs) are considered as a remarkable and promising stem cell source to be potentially used in cellular therapies. While no graft rejection has been reported in the recipient organism even in xeno-transplantation studies, attenuate tumor cell growth and gene transfers have been experimentally shown. In this study, we have demonstrated a reliable, reproducible and efficient cryopreservation method of hUCS-MSCs resulting in one of the highest cell survival rates reported so far. Conventional, computer-controlled multistep slow freezing (MSSF), and vitrification methods were comparatively tested using cell permeable [dimethylsulfoxide (DMSO), ethylene glycol] and impermeable [trehalose, sucrose, hydroxyethyl starch (HES), human serum albumin] cryoprotectant agents (CPAs). After determining the ice nucleation point for each solution, latent heat evolution was suppressed during freezing, followed by a cooling process to -40°C at 1°C/min or 0.3°C/min. The efficiency of the cryopreservation techniques used was determined by cell viability and proliferation assays, the expression of cell surface markers, cytoskeletal proteins and chromosome alignments. The cell survival rate was found to be highest (87 ± 5%) by MSSF with sucrose (0.1 M) +DMSO (10%) at 1°C/min freezing rate. In this group, no significant difference was noted before and after the cryopreservation in cell morphology, cytokeratin, vimentin, and α-smooth muscle actin profiles and the expressions of CD105, CD90, CD73, CD29 and HLA-DR. Second highest cell survival ratio (85 ± 6%) was obtained in DMSO (10%) alone at 1°C/min freezing rate. Interestingly, poor (18 ± 15%) cell survival rates were obtained after vitrification. Cumulatively, results indicated that MSSF favors the other freezing protocols with an addition of sucrose or DMSO alone depending on the freezing rate used. PMID:23270628

  20. Co-Targeting Prostate Cancer Epithelium and Bone Stroma by Human Osteonectin-Promoter-Mediated Suicide Gene Therapy Effectively Inhibits Androgen-Independent Prostate Cancer Growth.

    PubMed

    Sung, Shian-Ying; Chang, Junn-Liang; Chen, Kuan-Chou; Yeh, Shauh-Der; Liu, Yun-Ru; Su, Yen-Hao; Hsueh, Chia-Yen; Chung, Leland W K; Hsieh, Chia-Ling

    2016-01-01

    Stromal-epithelial interaction has been shown to promote local tumor growth and distant metastasis. We sought to create a promising gene therapy approach that co-targets cancer and its supporting stromal cells for combating castration-resistant prostate tumors. Herein, we demonstrated that human osteonectin is overexpressed in the prostate cancer epithelium and tumor stroma in comparison with their normal counterpart. We designed a novel human osteonectin promoter (hON-522E) containing positive transcriptional regulatory elements identified in both the promoter and exon 1 region of the human osteonectin gene. In vitro reporter assays revealed that the hON-522E promoter is highly active in androgen receptor negative and metastatic prostate cancer and bone stromal cells compared to androgen receptor-positive prostate cancer cells. Moreover, in vivo prostate-tumor-promoting activity of the hON-522E promoter was confirmed by intravenous administration of an adenoviral vector containing the hON-522E promoter-driven luciferase gene (Ad-522E-Luc) into mice bearing orthotopic human prostate tumor xenografts. In addition, an adenoviral vector with the hON-522E-promoter-driven herpes simplex virus thymidine kinase gene (Ad-522E-TK) was highly effective against the growth of androgen-independent human prostate cancer PC3M and bone stromal cell line in vitro and in pre-established PC3M tumors in vivo upon addition of the prodrug ganciclovir. Because of the heterogeneity of human prostate tumors, hON-522E promoter-mediated gene therapy has the potential for the treatment of hormone refractory and bone metastatic prostate cancers. PMID:27054343

  1. Long-lasting morphofunctional remodelling of liver parenchyma and stroma after a single exposure to low and moderate doses of cadmium in rats

    PubMed Central

    Cupertino, Marli C; Costa, Kyvia L C; Santos, Daiane C M; Novaes, Rômulo D; Condessa, Suellen S; Neves, Ana C; Oliveira, Juraci A; Matta, Sérgio L P

    2013-01-01

    Frequent exposure to cadmium (Cd) in low doses is common; however, the long-lasting effects of this exposure are still poorly understood. Therefore in this study we have evaluated long-lasting hepatic morphofunctional adaptations in rats exposed to low and moderate doses of Cd. Five experimental groups were tested: control (0.9% saline) and other four receiving single intraperitoneal doses of 0.67, 0.74, 0.86 and 1.1 mg of Cd/kg. The animals were killed after eight weeks and the following parameters were analysed: biometrics, oedema, Cd bio-accumulation, collagen, glycogen, lipid droplets, superoxide dismutase (SOD) and catalase (CAT), serum transaminases, liver histopathology and stereology. In all groups exposed to Cd there was significant increase in SOD and CAT activities, ALP levels, proportion of binucleated hepatocytes, nuclei/cytoplasm ratio, macrophages (Kupffer cells) and collagen fibres. In these groups, glycogen accumulation by hepatocytes and the proportion of sinusoidal capillaries were significantly reduced compared with controls. The liver somatic index was increased, and liver oedema was evident in animals exposed to higher dose of Cd. Areas of necrosis were found in animals exposed to the three highest doses. These results indicate that Cd is an extremely toxic bioactive heavy metal, which even at low doses is able to disrupt liver homeostasis. At low and moderate doses, Cd exposure induces morphofunctional pathological remodelling of the hepatic stroma and parenchyma, which remain active after eight weeks. In response to injury, the liver tissue triggers a reactive process by enhancing activation of antioxidant enzymes and collagenogenesis. PMID:24020407

  2. Chloroplast-Specific in Vivo Ca2+ Imaging Using Yellow Cameleon Fluorescent Protein Sensors Reveals Organelle-Autonomous Ca2+ Signatures in the Stroma.

    PubMed

    Loro, Giovanna; Wagner, Stephan; Doccula, Fabrizio Gandolfo; Behera, Smrutisanjita; Weinl, Stefan; Kudla, Joerg; Schwarzländer, Markus; Costa, Alex; Zottini, Michela

    2016-08-01

    In eukaryotes, subcellular compartments such as mitochondria, the endoplasmic reticulum, lysosomes, and vacuoles have the capacity for Ca(2+) transport across their membranes to modulate the activity of compartmentalized enzymes or to convey specific cellular signaling events. In plants, it has been suggested that chloroplasts also display Ca(2+) regulation. So far, monitoring of stromal Ca(2+) dynamics in vivo has exclusively relied on using the luminescent Ca(2+) probe aequorin. However, this technique is limited in resolution and can only provide a readout averaged over chloroplast populations from different cells and tissues. Here, we present a toolkit of Arabidopsis (Arabidopsis thaliana) Ca(2+) sensor lines expressing plastid-targeted FRET-based Yellow Cameleon (YC) sensors. We demonstrate that the probes reliably report in vivo Ca(2+) dynamics in the stroma of root plastids in response to extracellular ATP and of leaf mesophyll and guard cell chloroplasts during light-to-low-intensity blue light illumination transition. Applying YC sensing of stromal Ca(2+) dynamics to single chloroplasts, we confirm findings of gradual, sustained stromal Ca(2+) increases at the tissue level after light-to-low-intensity blue light illumination transitions, but monitor transient Ca(2+) spiking as a distinct and previously unknown component of stromal Ca(2+) signatures. Spiking was dependent on the availability of cytosolic Ca(2+) but not synchronized between the chloroplasts of a cell. In contrast, the gradual sustained Ca(2+) increase occurred independent of cytosolic Ca(2+), suggesting intraorganellar Ca(2+) release. We demonstrate the capacity of the YC sensor toolkit to identify novel, fundamental facets of chloroplast Ca(2+) dynamics and to refine the understanding of plastidial Ca(2+) regulation. PMID:27252306

  3. Co-Targeting Prostate Cancer Epithelium and Bone Stroma by Human Osteonectin-Promoter–Mediated Suicide Gene Therapy Effectively Inhibits Androgen-Independent Prostate Cancer Growth

    PubMed Central

    Sung, Shian-Ying; Chang, Junn-Liang; Chen, Kuan-Chou; Yeh, Shauh-Der; Liu, Yun-Ru; Su, Yen-Hao; Hsueh, Chia-Yen; Chung, Leland W. K.; Hsieh, Chia-Ling

    2016-01-01

    Stromal-epithelial interaction has been shown to promote local tumor growth and distant metastasis. We sought to create a promising gene therapy approach that co-targets cancer and its supporting stromal cells for combating castration-resistant prostate tumors. Herein, we demonstrated that human osteonectin is overexpressed in the prostate cancer epithelium and tumor stroma in comparison with their normal counterpart. We designed a novel human osteonectin promoter (hON-522E) containing positive transcriptional regulatory elements identified in both the promoter and exon 1 region of the human osteonectin gene. In vitro reporter assays revealed that the hON-522E promoter is highly active in androgen receptor negative and metastatic prostate cancer and bone stromal cells compared to androgen receptor-positive prostate cancer cells. Moreover, in vivo prostate-tumor–promoting activity of the hON-522E promoter was confirmed by intravenous administration of an adenoviral vector containing the hON-522E promoter-driven luciferase gene (Ad-522E-Luc) into mice bearing orthotopic human prostate tumor xenografts. In addition, an adenoviral vector with the hON-522E-promoter–driven herpes simplex virus thymidine kinase gene (Ad-522E-TK) was highly effective against the growth of androgen-independent human prostate cancer PC3M and bone stromal cell line in vitro and in pre-established PC3M tumors in vivo upon addition of the prodrug ganciclovir. Because of the heterogeneity of human prostate tumors, hON-522E promoter-mediated gene therapy has the potential for the treatment of hormone refractory and bone metastatic prostate cancers. PMID:27054343

  4. Glioma-Derived Platelet-Derived Growth Factor-BB Recruits Oligodendrocyte Progenitor Cells via Platelet-Derived Growth Factor Receptor-α and Remodels Cancer Stroma.

    PubMed

    Zheng, Yang; Yamamoto, Seiji; Ishii, Yoko; Sang, Yang; Hamashima, Takeru; Van De, Nguyen; Nishizono, Hirofumi; Inoue, Ran; Mori, Hisashi; Sasahara, Masakiyo

    2016-05-01

    Glioma is an aggressive and incurable disease, and is frequently accompanied by augmented platelet-derived growth factor (PDGF) signaling. Overexpression of PDGF-B ligand characterizes a specific subclass of glioblastoma multiforme, but the significance of the ligand remains to be elucidated. For this end, we implanted a glioma-cell line transfected with PDGF-BB-overexpressing vector (GL261-PDGF-BB) or control vector (GL261-vector) into wild-type mouse brain, and examined the effect of glioma-derived PDGF on the tumor microenvironment. The volume of GL261-PDGF-BB rapidly increased compared with GL261-vector. Recruitment of many PDGF receptor (PDGFR)-α and Olig2-positive oligodendrocyte precursor cells and frequent hemorrhages were observed in GL261-PDGF-BB but not in GL261-vector. We then implanted GL261-PDGF-BB into the mouse brain with and without Pdgfra gene inactivation, corresponding to PDGFRα-knockout (KO) and Flox mice, respectively. The recruitment of oligodendrocyte precursor cells was largely suppressed in PDGFRα-KO than in Flox, whereas the volume of GL261-PDGF-BB was comparable between the two genotypes. Frequent hemorrhage and increased IgG-leakage were associated with aberrant vascular structures within the area where many recruited oligodendrocyte precursor cells accumulated in Flox. In contrast, these vascular phenotypes were largely normalized in PDGFRα-KO. Increased matrix metalloproteinase-9 in recruited oligodendrocyte precursor cells and decreased claudin-5 in vasculature may underlie the vascular abnormality. Glioma-derived PDGF-B signal induces cancer stroma characteristically seen in high-grade glioma, and should be therapeutically targeted to improve cancer microenvironment. PMID:26945107

  5. Clonal growth and plant species abundance

    PubMed Central

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-01-01

    Background and Aims Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf–height–seed) traits and by actual performance in the botanical garden. Methods Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area – height – seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. Key Results After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Conclusions Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially

  6. Why is Trichodesmium abundant in the Kuroshio?

    NASA Astrophysics Data System (ADS)

    Shiozaki, T.; Takeda, S.; Itoh, S.; Kodama, T.; Liu, X.; Hashihama, F.; Furuya, K.

    2015-12-01

    The genus Trichodesmium is recognized as an abundant and major diazotroph in the Kuroshio, but the reason for this remains unclear. The present study investigated the abundance of Trichodesmium spp. and nitrogen fixation together with concentrations of dissolved iron and phosphate in the Kuroshio and its marginal seas. We performed the observations near the Miyako Islands, which form part of the Ryukyu Islands, situated along the Kuroshio, since our satellite analysis suggested that material transport could occur from the islands to the Kuroshio. Trichodesmium spp. bloomed (> 20 000 filaments L-1) near the Miyako Islands, abundance was high in the Kuroshio and the Kuroshio bifurcation region of the East China Sea, but was low in the Philippine Sea. The abundance of Trichodesmium spp. was significantly correlated with the total nitrogen fixation activity. The surface concentrations of dissolved iron (0.19-0.89 nM) and phosphate (< 3-36 nM) were similar for all of the study areas, indicating that the nutrient distribution could not explain the spatial differences in Trichodesmium spp. abundance and nitrogen fixation. Numerical particle-tracking experiments simulated the transportation of water around the Ryukyu Islands to the Kuroshio. Our results indicate that Trichodesmium growing around the Ryukyu Islands could be advected into the Kuroshio.

  7. Abundances in Eight M31 Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Hensley, Kerry G.; Kwitter, Karen B.; Corradi, Romano; Galera-Rosillo, R.; Balick, Bruce; Henry, Richard B. C.

    2014-06-01

    As part of a continuing project using planetary nebulae (PNe) to study the chemical evolution and formation history of M31 (see accompanying poster by Balick et al.), we obtained spectra of eight PNe in the fall of 2013 with the OSIRIS spectrograph on the GTC. All of these PNe are located outside M31’s inner disk and bulge. Spectral coverage extended from 3700-7800Å with a resolution of ~6 Å. Especially important in abundance determinations is the detection of the weak, temperature-sensitive auroral line of [O III], at 4363Å, which is often contaminated by Hg I 4358Å from streetlights; the remoteness of the GTC eliminated this difficulty. We reduced and measured the spectra using IRAF, and derived nebular diagnostics and abundances with ELSA, our in-house five-level-atom program. Here we report the chemical abundances determined from these spectra. The bottom line is that the oxygen abundances in these PNe are all within a factor of 2-3 of the solar value, (as are all the other M31 PNe our team has previously measured) despite the significant range of galactocentric distance. Future work will use these abundances to constrain models of the central star to estimate progenitor masses and ages. In particular we will use the results to investigate the hypothesis that these PNe might represent a population related to the encounter between M31 and M33 ~3 Gy ago. We gratefully acknowledge support from Williams College.

  8. Accurate abundance determinations in S stars

    NASA Astrophysics Data System (ADS)

    Neyskens, P.; Van Eck, S.; Plez, B.; Goriely, S.; Siess, L.; Jorissen, A.

    2011-12-01

    S-type stars are thought to be the first objects, during their evolution on the asymptotic giant branch (AGB), to experience s-process nucleosynthesis and third dredge-ups, and therefore to exhibit s-process signatures in their atmospheres. Until present, the modeling of these processes is subject to large uncertainties. Precise abundance determinations in S stars are of extreme importance for constraining e.g., the depth and the formation of the 13C pocket. In this paper a large grid of MARCS model atmospheres for S stars is used to derive precise abundances of key s-process elements and iron. A first estimation of the atmospheric parameters is obtained using a set of well-chosen photometric and spectroscopic indices for selecting the best model atmosphere of each S star. Abundances are derived from spectral line synthesis, using the selected model atmosphere. Special interest is paid to technetium, an element without stable isotopes. Its detection in stars is considered as the best possible signature that the star effectively populates the thermally-pulsing AGB (TP-AGB) phase of evolution. The derived Tc/Zr abundances are compared, as a function of the derived [Zr/Fe] overabundances, with AGB stellar model predictions. The computed [Zr/Fe] overabundances are in good agreement with the AGB stellar evolution model predictions, while the Tc/Zr abundances are slightly over-predicted. This discrepancy can help to set stronger constraints on nucleosynthesis and mixing mechanisms in AGB stars.

  9. Relative Abundance Measurements in Plumes and Interplumes

    NASA Astrophysics Data System (ADS)

    Guennou, C.; Hahn, M.; Savin, D. W.

    2015-07-01

    We present measurements of relative elemental abundances in plumes and interplumes. Plumes are bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Previous work has found that in some coronal structures the abundances of elements with a low first ionization potential (FIP) <10 eV are enhanced relative to their photospheric abundances. This coronal-to-photospheric abundance ratio, commonly called the FIP bias, is typically 1 for elements with a high-FIP (>10 eV). We have used Extreme Ultraviolet Imaging Spectrometer observations made on 2007 March 13 and 14 over a ≈24 hr period to characterize abundance variations in plumes and interplumes. To assess their elemental composition, we used a differential emission measure analysis, which accounts for the thermal structure of the observed plasma. We used lines from ions of iron, silicon, and sulfur. From these we estimated the ratio of the iron and silicon FIP bias relative to that for sulfur. From the results, we have created FIP-bias-ratio maps. We find that the FIP-bias ratio is sometimes higher in plumes than in interplumes and that this enhancement can be time dependent. These results may help to identify whether plumes or interplumes contribute to the fast solar wind observed in situ and may also provide constraints on the formation and heating mechanisms of plumes.

  10. Hierarchical models of animal abundance and occurrence

    USGS Publications Warehouse

    Royle, J. Andrew; Dorazio, R.M.

    2006-01-01

    Much of animal ecology is devoted to studies of abundance and occurrence of species, based on surveys of spatially referenced sample units. These surveys frequently yield sparse counts that are contaminated by imperfect detection, making direct inference about abundance or occurrence based on observational data infeasible. This article describes a flexible hierarchical modeling framework for estimation and inference about animal abundance and occurrence from survey data that are subject to imperfect detection. Within this framework, we specify models of abundance and detectability of animals at the level of the local populations defined by the sample units. Information at the level of the local population is aggregated by specifying models that describe variation in abundance and detection among sites. We describe likelihood-based and Bayesian methods for estimation and inference under the resulting hierarchical model. We provide two examples of the application of hierarchical models to animal survey data, the first based on removal counts of stream fish and the second based on avian quadrat counts. For both examples, we provide a Bayesian analysis of the models using the software WinBUGS.

  11. Abundance and chemistry of interstellar HOCO(+)

    NASA Technical Reports Server (NTRS)

    Minh, Y. C.; Brewer, M. K.; Irvine, W. M.; Friberg, P.; Johansson, L. E. B.

    1991-01-01

    Column densities of 10 to the 15th/sq cm toward the Galactic center and not more than 10 to the 12th/sq cm for cold dark clouds are derived from observations using an LVG model, and the chemical implications are discussed. The HOCO(+) 4(04)-3(03) line toward Sgr A is mapped. The fractional abundance of HOCO(+) in the Galactic center region was found to be three orders of magnitude larger than predicted by quiescent ion-molecule chemistry and an order of magnitude larger than predicted by an MHD shock model. It is suggested that the possibly high CO2 abundance, and consequently the observed HOCO(+) abundance in the Galactic center, may result from UV photolysis of grain mantles.

  12. Earth-Abundant Nanomaterials for Oxygen Reduction.

    PubMed

    Xia, Wei; Mahmood, Asif; Liang, Zibin; Zou, Ruqiang; Guo, Shaojun

    2016-02-18

    Replacing the rare and precious platinum (Pt) electrocatalysts with earth-abundant materials for promoting the oxygen reduction reaction (ORR) at the cathode of fuel cells is of great interest in developing high-performance sustainable energy devices. However, the challenging issues associated with non-Pt materials are still their low intrinsic catalytic activity, limited active sites, and the poor mass transport properties. Recent advances in material sciences and nanotechnology enable rational design of new earth-abundant materials with optimized composition and fine nanostructure, providing new opportunities for enhancing ORR performance at the molecular level. This Review highlights recent breakthroughs in engineering nanocatalysts based on the earth-abundant materials for boosting ORR. PMID:26663778

  13. Rare-earth abundances in chondritic meteorites

    NASA Technical Reports Server (NTRS)

    Evensen, N. M.; Hamilton, P. J.; Onions, R. K.

    1978-01-01

    Fifteen chondrites, including eight carbonaceous chondrites, were analyzed for rare earth element abundances by isotope dilution. Examination of REE for a large number of individual chondrites shows that only a small proportion of the analyses have flat unfractionated REE patterns within experimental error. While some of the remaining analyses are consistent with magmatic fractionation, many patterns, in particular those with positive Ce anomalies, can not be explained by known magmatic processes. Elemental abundance anomalies are found in all major chondrite classes. The persistence of anomalies in chondritic materials relatively removed from direct condensational processes implies that anomalous components are resistant to equilibrium or were introduced at a late stage of chondrite formation. Large-scale segregation of gas and condensate is implied, and bulk variations in REE abundances between planetary bodies is possible.

  14. Absolute isotopic abundances of TI in meteorites

    NASA Astrophysics Data System (ADS)

    Niederer, F. R.; Papanastassiou, D. A.; Wasserburg, G. J.

    1985-03-01

    The absolute isotope abundance of Ti has been determined in Ca-Al-rich inclusions from the Allende and Leoville meteorites and in samples of whole meteorites. The absolute Ti isotope abundances differ by a significant mass dependent isotope fractionation transformation from the previously reported abundances, which were normalized for fractionation using 46Ti/48Ti. Therefore, the absolute compositions define distinct nucleosynthetic components from those previously identified or reflect the existence of significant mass dependent isotope fractionation in nature. The authors provide a general formalism for determining the possible isotope compositions of the exotic Ti from the measured composition, for different values of isotope fractionation in nature and for different mixing ratios of the exotic and normal components.

  15. Age-abundance relationships for neutral communities.

    PubMed

    Danino, Matan; Shnerb, Nadav M

    2015-10-01

    Neutral models for the dynamics of a system of competing species are often used to describe a wide variety of empirical communities. These models are used in many situations, ranging from population genetics and ecological biodiversity to macroevolution and cancer tumors. One of the main issues discussed within this framework is the relationships between the abundance of a species and its age. Here we provide a comprehensive analysis of the age-abundance relationships for fixed-size and growing communities. Explicit formulas for the average and the most likely age of a species with abundance n are given, together with the full probability distribution function. We further discuss the universality of these results and their applicability to the tropical forest community. PMID:26565271

  16. Age-abundance relationships for neutral communities

    NASA Astrophysics Data System (ADS)

    Danino, Matan; Shnerb, Nadav M.

    2015-10-01

    Neutral models for the dynamics of a system of competing species are often used to describe a wide variety of empirical communities. These models are used in many situations, ranging from population genetics and ecological biodiversity to macroevolution and cancer tumors. One of the main issues discussed within this framework is the relationships between the abundance of a species and its age. Here we provide a comprehensive analysis of the age-abundance relationships for fixed-size and growing communities. Explicit formulas for the average and the most likely age of a species with abundance n are given, together with the full probability distribution function. We further discuss the universality of these results and their applicability to the tropical forest community.

  17. Beryllium Abundances in Solar Mass Stars

    NASA Astrophysics Data System (ADS)

    Krugler, J. A.; Boesgaard, A. M.

    2008-08-01

    Light element abundance analysis allows for a deeper understanding of the chemical composition of a star beneath its surface. Beryllium provides a probe down to 3.5×106 K, where it fuses with protons. In this study, Be abundances were determined for 52 F and G dwarfs selected from a sample of local thin disc stars. These stars were selected by mass to range from 0.9 to 1.1 M⊙. They have effective temperatures from 5600 to 6400 K, and their metallicities [Fe/H]=-0.65 to +0.11. The data were taken with the Keck HIRES instrument and the Gecko spectrograph on the Canada France Hawaii Telescope. The abundances were calculated via spectral synthesis and were analyzed to investigate the Be abundance as a function of age, temperature, metallicity, and its relation to the lithium abundance for this narrow mass range. Be is found to decrease linearly with metallicity down to [Fe/H]˜-4.0 with slope 0.86 ± 0.02. The relation of the Be abundance to effective temperature is dependent upon metallicity, but when metallicity effects are taken into account, there is a spread ˜1.2 dex. We find a 1.5 dex spread in A(Be) when plotted against age, with the largest spread occurring from 6-8 Gyr. The relation with Li is found to be linear with slope 0.36 ± 0.06 for the temperature regime of 5900-6300 K.

  18. Beryllium Abundances in Solar Mass Stars

    NASA Astrophysics Data System (ADS)

    Krugler, Julie A.; Boesgaard, A. M.

    2007-12-01

    Light element abundance analysis allows for a deeper understanding of the chemical composition of a star beneath its surface. Beryllium provides a probe down to 3.5x106 K, where it fuses with protons. In this study, Be abundances were determined for 52 F and G dwarfs selected from a sample of local thin disc stars. These stars were selected by their mass to be in a mass range of 0.9 to 1.1 solar masses as determined by Lambert & Reddy (2004). They have effective temperatures from 5600 to 6400 K, and their metallicities [Fe/H] -0.65 to +0.11. The data were taken over several nights, with forty-six spectra taken with the Keck HIRES instrument and six spectra on the Canada France Hawaii Telescope (CFHT) using the Gecko spectrograph. The abundances were calculated via spectral synthesis, fitting a 4Å region around the resonance lines of Be II. The data were then analyzed to investigate the Be abundance as a function of age, temperature, and metallicity and its relation to the lithium abundance for this narrow mass range. Be is found to increase with metallicity and the linear relationship evident when extended to metallicities down to -4.0 dex with slope 0.86 ± 0.02. The relation of the Be abundance to effective temperature is dependent upon metallicity, but when metallicity effects are taken into account, there is a spread 1.2 dex. We find a 1.5 dex spread in A(Be) when plotted against age, with the largest spread occurring from 6-8 Gyr. The relation with Li is found to be linear with slope 0.36 ± 0.06 for the temperature regime of 5900-6300 K. This research was conducted through the Research Experiences for Undergraduate (REU) program at the University of Hawaii's Institute for Astronomy and was funded by the NSF.

  19. Reliability of indicators of decline in abundance.

    PubMed

    Porszt, Erin J; Peterman, Randall M; Dulvy, Nicholas K; Cooper, Andrew B; Irvine, James R

    2012-10-01

    Although there are many indicators of endangerment (i.e., whether populations or species meet criteria that justify conservation action), their reliability has rarely been tested. Such indicators may fail to identify that a population or species meets criteria for conservation action (false negative) or may incorrectly show that such criteria have been met (false positive). To quantify the rate of both types of error for 20 commonly used indicators of declining abundance (threat indicators), we used receiver operating characteristic curves derived from historical (1938-2007) data for 18 sockeye salmon (Oncorhynchus nerka) populations in the Fraser River, British Columbia, Canada. We retrospectively determined each population's yearly status (reflected by change in abundance over time) on the basis of each indicator. We then compared that population's status in a given year with the status in subsequent years (determined by the magnitude of decline in abundance across those years). For each sockeye population, we calculated how often each indicator of past status matched subsequent status. No single threat indicator provided error-free estimates of status, but indicators that reflected the extent (i.e., magnitude) of past decline in abundance (through comparison of current abundance with some historical baseline abundance) tended to better reflect status in subsequent years than the rate of decline over the previous 3 generations (a widely used indicator). We recommend that when possible, the reliability of various threat indicators be evaluated with empirical analyses before such indicators are used to determine the need for conservation action. These indicators should include estimates from the entire data set to take into account a historical baseline. PMID:22741815

  20. INTERSTELLAR ABUNDANCES TOWARD X Per, REVISITED

    SciTech Connect

    Valencic, Lynne A.; Smith, Randall K.

    2013-06-10

    The nearby X-ray binary X Per (HD 24534) provides a useful beacon with which to examine dust grain types and measure elemental abundances in the local interstellar medium (ISM). The absorption features of O, Fe, Mg, and Si along this line of sight were measured using spectra from the Chandra X-Ray Observatory's LETG/ACIS-S and XMM-Newton's RGS instruments, and the Spex software package. The spectra were fit with dust analogs measured in the laboratory. The O, Mg, and Si abundances were compared to those from standard references, and the O abundance was compared to that along lines of sight toward other X-ray binaries. The results are as follows. First, it was found that a combination of MgSiO{sub 3} (enstatite) and Mg{sub 1.6}Fe{sub 0.4}SiO{sub 4} (olivine) provided the best fit to the O K edge, with N(MgSiO{sub 3})/N(Mg{sub 1.6}Fe{sub 0.4}SiO{sub 4}) = 3.4. Second, the Fe L edge could be fit with models that included metallic iron, but it was not well described by the laboratory spectra currently available. Third, the total abundances of O, Mg, and Si were in very good agreement with that of recently re-analyzed B stars, suggesting that they are good indicators of abundances in the local ISM, and the depletions were also in agreement with expected values for the diffuse ISM. Finally, the O abundances found from X-ray binary absorption spectra show a similar correlation with Galactocentric distances as seen in other objects.

  1. The evolution of abundances in the Galaxy

    NASA Astrophysics Data System (ADS)

    Audouze, J.

    This very brief review of the evolution of the abundances in the Galaxy first recalls the main observational facts regarding such abundances. After having defined what are the crucial parameters which define such model, emphasis is given to two approaches: the first analyzed by Vangioni-Flam and Audouze (1988), and Andreani et al. (1988), in which the rate of star formation is allowed to vary with time; the second approach was favored by Matteucci and Francois (1989), who invoke a multizone galactic model with infall (inflow) of external gas into the galactic disk.

  2. ABUNDANT OR RARE? A HYBRID APPROACH FOR DETERMINING SPECIES RELATIVE ABUNDANCE AT AN ECOREGOIONAL SCALE - 2014

    EPA Science Inventory

    Everyone knows what abundant and rare species are, but quantifying the concept proves elusive. As part of an EPA/USGS project to assess near-coastal species vulnerability to climate change affects, we designed a hybrid approach to determine species relative abundance at an ecoreg...

  3. ABUNDANT OR RARE? A HYBRID APPROACH FOR DETERMINING SPECIES RELATIVE ABUNDANCE AT AN ECOREGOIONAL SCALE

    EPA Science Inventory

    Everyone knows what abundant and rare species are, but quantifying the concept proves elusive. As part of an EPA/USGS project to assess near-coastal species vulnerability to climate change affects, we designed a hybrid approach to determine species relative abundance at an ecoreg...

  4. Empirical oxygen abundances and physical conditions for relatively low abundance H II regions

    SciTech Connect

    Skillman, E.D. )

    1989-12-01

    The utility of the emission-line ratio (3727 + 4959 + 5007 A)/H-beta as an estimate of the total oxygen abundance in H II regions of low abundance (less than 10 percent of the solar value) is discussed. Using both observational data where the 4363A line is measured and model H II regions it is concluded that, for low abundance systems, total oxygen abundances can be determined with an accuracy of + or - 0.2 dex in the absence of a 4363A measurement. An attempt is made to study the average behavior of the stellar effective temperature (Teff) and ionization parameter (U) with changing abundance in low abundance systems. It is shown that some diagnostic methods which are viable for high abundance systems are not capable of uniquely determining Teff and U in low abundance systems. The most promising method of determining Teff and U requires measuring emission lines of forbidden O II, O III, S II, and S III. 53 refs.

  5. Toward Reliable Estimates of Abundance: Comparing Index Methods to Assess the Abundance of a Mammalian Predator

    PubMed Central

    Güthlin, Denise; Storch, Ilse; Küchenhoff, Helmut

    2014-01-01

    Due to time and financial constraints indices are often used to obtain landscape-scale estimates of relative species abundance. Using two different field methods and comparing the results can help to detect possible bias or a non monotonic relationship between the index and the true abundance, providing more reliable results. We used data obtained from camera traps and feces counts to independently estimate relative abundance of red foxes in the Black Forest, a forested landscape in southern Germany. Applying negative binomial regression models, we identified landscape parameters that influence red fox abundance, which we then used to predict relative red fox abundance. We compared the estimated regression coefficients of the landscape parameters and the predicted abundance of the two methods. Further, we compared the costs and the precision of the two field methods. The predicted relative abundances were similar between the two methods, suggesting that the two indices were closely related to the true abundance of red foxes. For both methods, landscape diversity and edge density best described differences in the indices and had positive estimated effects on the relative fox abundance. In our study the costs of each method were of similar magnitude, but the sample size obtained from the feces counts (262 transects) was larger than the camera trap sample size (88 camera locations). The precision of the camera traps was lower than the precision of the feces counts. The approach we applied can be used as a framework to compare and combine the results of two or more different field methods to estimate abundance and by this enhance the reliability of the result. PMID:24743565

  6. Elemental abundances in meteoritic and terrestrial matter

    NASA Technical Reports Server (NTRS)

    Schmitt, R. A.

    1974-01-01

    Major and trace element analyses of over 180 individual chondrules from 12 carbonaceous chondrites are reported, including individual analyses of 60 chondrules from Pueblito de Allende. Siderophile elements in most chondrules are depleted, compared to the whole chondrite. Correlations of Al-Ir and Ir-Sc among chondrules high in Ca and Al were observed. A Cu-Mn correlation was also found for chondrules from some meteorites. No correlation was observed between Au and other siderophile elements (Fe, Ni, Co and Ir). It is suggested that these elemental associations were present in the material from which the chondrules formed. Compositionally, chondrules appear to be a multicomponent mixture of remelted dust. One component displaying an Al-Ir correlation is identified as Allende-type white aggregates. The other components are a material chemically similar to the present matrix and sulfides-plus-metal material. Abundances of the REE (rare earth elements) were measured in ordinary Allende chondrules and were 50% higher than REE abundances in Mokoia chondrules; REE abundances in Ca-Al rich chondrules were similar to REE abundances in Ca-rich white aggregates.

  7. The Abundance of Large Arcs From CLASH

    NASA Astrophysics Data System (ADS)

    Xu, Bingxiao; Postman, Marc; Meneghetti, Massimo; Coe, Dan A.; Clash Team

    2015-01-01

    We have developed an automated arc-finding algorithm to perform a rigorous comparison of the observed and simulated abundance of large lensed background galaxies (a.k.a arcs). We use images from the CLASH program to derive our observed arc abundance. Simulated CLASH images are created by performing ray tracing through mock clusters generated by the N-body simulation calibrated tool -- MOKA, and N-body/hydrodynamic simulations -- MUSIC, over the same mass and redshift range as the CLASH X-ray selected sample. We derive a lensing efficiency of 15 ± 3 arcs per cluster for the X-ray selected CLASH sample and 4 ± 2 arcs per cluster for the simulated sample. The marginally significant difference (3.0 σ) between the results for the observations and the simulations can be explained by the systematically smaller area with magnification larger than 3 (by a factor of ˜4) in both MOKA and MUSIC mass models relative to those derived from the CLASH data. Accounting for this difference brings the observed and simulated arc statistics into full agreement. We find that the source redshift distribution does not have big impact on the arc abundance but the arc abundance is very sensitive to the concentration of the dark matter halos. Our results suggest that the solution to the "arc statistics problem" lies primarily in matching the cluster dark matter distribution.

  8. Photoelectric absorption cross sections with variable abundances

    NASA Technical Reports Server (NTRS)

    Balucinska-Church, Monika; Mccammon, Dan

    1992-01-01

    Polynomial fit coefficients have been obtained for the energy dependences of the photoelectric absorption cross sections of 17 astrophysically important elements. These results allow the calculation of X-ray absorption in the energy range 0.03-10 keV in material with noncosmic abundances.

  9. Will Abundant Natural Gas Solve Climate Change?

    NASA Astrophysics Data System (ADS)

    McJeon, H. C.; Edmonds, J.; Bauer, N.; Leon, C.; Fisher, B.; Flannery, B.; Hilaire, J.; Krey, V.; Marangoni, G.; Mi, R.; Riahi, K.; Rogner, H.; Tavoni, M.

    2015-12-01

    The rapid deployment of hydraulic fracturing and horizontal drilling technologies enabled the production of previously uneconomic shale gas resources in North America. Global deployment of these advanced gas production technologies could bring large influx of economically competitive unconventional gas resources to the energy system. It has been hoped that abundant natural gas substituting for coal could reduce carbon dioxide (CO2) emissions, which in turn could reduce climate forcing. Other researchers countered that the non-CO2 greenhouse gas (GHG) emissions associated with shale gas production make its lifecycle emissions higher than those of coal. In this study, we employ five state-of-the-art integrated assessment models (IAMs) of energy-economy-climate systems to assess the full impact of abundant gas on climate change. The models show large additional natural gas consumption up to +170% by 2050. The impact on CO2 emissions, however, is found to be much smaller (from -2% to +11%), and a majority of the models reported a small increase in climate forcing (from -0.3% to +7%) associated with the increased use of abundant gas. Our results show that while globally abundant gas may substantially change the future energy market equilibrium, it will not significantly mitigate climate change on its own in the absence of climate policies.

  10. In Abundance: Networked Participatory Practices as Scholarship

    ERIC Educational Resources Information Center

    Stewart, Bonnie E.

    2015-01-01

    In an era of knowledge abundance, scholars have the capacity to distribute and share ideas and artifacts via digital networks, yet networked scholarship often remains unrecognized within institutional spheres of influence. Using ethnographic methods including participant observation, interviews, and document analysis, this study investigates…

  11. Mimicking Metastases Including Tumor Stroma: A New Technique to Generate a Three-Dimensional Colorectal Cancer Model Based on a Biological Decellularized Intestinal Scaffold

    PubMed Central

    Nietzer, Sarah; Baur, Florentin; Sieber, Stefan; Hansmann, Jan; Schwarz, Thomas; Stoffer, Carolin; Häfner, Heide; Gasser, Martin; Waaga-Gasser, Ana Maria; Walles, Heike

    2016-01-01

    generation, a bioreactor was constructed for dynamic culture approaches. This induced a close tissue-like association of cultured tumor cells with fibroblasts reflecting tumor biopsies. Therapy with 5-fluorouracil (5-FU) was effective only in 3D coculture. In conclusion, our 3D tumor model reflects human tissue-related tumor characteristics, including lower tumor cell proliferation. It is now available for drug testing in metastatic context—especially for substances targeting tumor–stroma interactions. PMID:27137941

  12. Mimicking Metastases Including Tumor Stroma: A New Technique to Generate a Three-Dimensional Colorectal Cancer Model Based on a Biological Decellularized Intestinal Scaffold.

    PubMed

    Nietzer, Sarah; Baur, Florentin; Sieber, Stefan; Hansmann, Jan; Schwarz, Thomas; Stoffer, Carolin; Häfner, Heide; Gasser, Martin; Waaga-Gasser, Ana Maria; Walles, Heike; Dandekar, Gudrun

    2016-07-01

    generation, a bioreactor was constructed for dynamic culture approaches. This induced a close tissue-like association of cultured tumor cells with fibroblasts reflecting tumor biopsies. Therapy with 5-fluorouracil (5-FU) was effective only in 3D coculture. In conclusion, our 3D tumor model reflects human tissue-related tumor characteristics, including lower tumor cell proliferation. It is now available for drug testing in metastatic context-especially for substances targeting tumor-stroma interactions. PMID:27137941

  13. Cold acclimation of Arabidopsis thaliana results in incomplete recovery of photosynthetic capacity, associated with an increased reduction of the chloroplast stroma.

    PubMed

    Savitch, L V; Barker-Astrom, J; Ivanov, A G; Hurry, V; Oquist, G; Huner, N P; Gardeström, P

    2001-12-01

    The effects of short-term cold stress and long-term cold acclimation on the light reactions of photosynthesis were examined in vivo to assess their contributions to photosynthetic acclimation to low temperature in Arabidopsis thaliana (L.) Heynh.. All photosynthetic measurements were made at the temperature of exposure: 23 degrees C for non-acclimated plants and 5 degrees C for cold-stressed and cold-acclimated plants. Three-day cold-stress treatments at 5 degrees C inhibited light-saturated rates of CO2 assimilation and O2 evolution by approximately 75%. The 3-day exposure to 5 degrees C also increased the proportion of reduced QA by 50%, decreased the yield of PSII electron transport by 65% and decreased PSI activity by 31%. In contrast, long-term cold acclimation resulted in a strong but incomplete recovery of light-saturated photosynthesis at 5 degrees C. The rates of light-saturated CO2 and O2 gas exchange and the in vivo yield of PSII activity under light-saturating conditions were only 35-40% lower, and the relative redox state of QA only 20% lower, at 5 degrees C after cold acclimation than in controls at 23 degrees C. PSI activity showed full recovery during long-term cold acclimation. Neither short-term cold stress nor long-term cold acclimation of Arabidopsis was associated with a limitation in ATP, and both treatments resulted in an increase in the ATP/NADPH ratio. This increase in ATP/NADPH was associated with an inhibition of PSI cyclic electron transport but there was no apparent change in the Mehler reaction activity in either cold-stressed or cold-acclimated leaves. Cold acclimation also resulted in an increase in the reduction state of the stroma, as indicated by an increased total activity and activation state of NADP-dependent malate dehydrogenase, and increased light-dependent activities of the major regulatory enzymes of the oxidative pentose-phosphate pathway. We suggest that the photosynthetic capacity during cold stress as well as cold

  14. Thermal relics: Do we know their abundances

    NASA Technical Reports Server (NTRS)

    Kamionkowski, Marc; Turner, Michael S.

    1990-01-01

    The relic abundance of a particle species that was once in thermal equilibrium in the expanding Universe depends upon a competition between the annihilation rate of the species and the expansion rate of the Universe. Assuming that the Universe is radiation dominated at early times the relic abundance is easy to compute and well known. At times earlier than about 1 sec after the bang there is little or no evidence that the Universe had to be radiation dominated, although that is the simplest and standard assumption. Because early-Universe relics are of such importance both to particle physics and to cosmology, three nonstandard possibilities are considered in detail for the Universe at the time a species' abundance froze in: energy density dominated by shear (i.e., anisotropic expansion), energy density dominated by some other nonrelativistic species, and energy density dominated by the kinetic energy of the scalar field that sets the gravitational constant in a Brans-Dicke-Jordan cosmological mode. In the second case the relic abundance is less than the standard value, while in the other two cases it can be enhanced by a significant factor. Two other more exotic possibilities for enhancing the relic abundance of a species are also mentioned--a larger value of Newton's constant at early times (e.g., as might occur in superstring or Kaluza-Klein theories) or a component of the energy density at early times with a very stiff equation of state (p greater than rho/3), e.g., a scalar field phi with potential V(phi) = Beta /phi/ (exp n) with n greater than 4. Results have implications for dark matter searches and searches for particle relics in general.

  15. Chemical abundances and kinematics of barium stars

    NASA Astrophysics Data System (ADS)

    de Castro, D. B.; Pereira, C. B.; Roig, F.; Jilinski, E.; Drake, N. A.; Chavero, C.; Silva, J. V. Sales

    2016-04-01

    In this paper we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scale height, radial velocities, abundances of the Na, Al, alpha-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code MOOG. We found that the metallicities, the temperatures and the surface gravities for barium stars can not be represented by a single gaussian distribution. The abundances of alpha-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heavy-element abundance pattern as given by the ratio [s/Fe], we found that the barium stars present several degrees of enrichment. We also obtained the [hs/ls] ratio by measuring the photospheric abundances of the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and the [hs/ls] ratios are strongly anti-correlated with the metallicity. Our kinematical analysis showed that 90% of the barium stars belong to the thin disk population. Based on their luminosities, none of the barium stars are luminous enough to be an AGB star, nor to become self-enriched in the s-process elements. Finally, we determined that the barium stars also follow an age-metallicity relation.

  16. Chemical abundances and kinematics of barium stars

    NASA Astrophysics Data System (ADS)

    de Castro, D. B.; Pereira, C. B.; Roig, F.; Jilinski, E.; Drake, N. A.; Chavero, C.; Sales Silva, J. V.

    2016-07-01

    In this paper, we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scaleheight, radial velocities, abundances of the Na, Al, α-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local thermodynamic equilibrium model atmospheres of Kurucz and the spectral analysis code MOOG. We found that the metallicities, the temperatures and the surface gravities for barium stars cannot be represented by a single Gaussian distribution. The abundances of α-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heavy-element abundance pattern as given by the ratio [s/Fe], we found that the barium stars present several degrees of enrichment. We also obtained the [hs/ls] ratio by measuring the photospheric abundances of the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and the [hs/ls] ratios are strongly anticorrelated with the metallicity. Our kinematical analysis showed that 90 per cent of the barium stars belong to the thin disc population. Based on their luminosities, none of the barium stars are luminous enough to be an asymptotic giant branch star, nor to become self-enriched in the s-process elements. Finally, we determined that the barium stars also follow an age-metallicity relation.

  17. Human Embryonic Stem Cell-Derived Mesenchymal Stroma Cells (hES-MSCs) Engraft In Vivo and Support Hematopoiesis without Suppressing Immune Function: Implications for Off-The Shelf ES-MSC Therapies

    PubMed Central

    Li, Ou; Tormin, Ariane; Sundberg, Berit; Hyllner, Johan; Le Blanc, Katarina; Scheding, Stefan

    2013-01-01

    Mesenchymal stroma cells (MSCs) have a high potential for novel cell therapy approaches in clinical transplantation. Commonly used bone marrow-derived MSCs (BM-MSCs), however, have a restricted proliferative capacity and cultures are difficult to standardize. Recently developed human embryonic stem cell-derived mesenchymal stroma cells (hES-MSCs) might represent an alternative and unlimited source of hMSCs. We therefore compared human ES-cell-derived MSCs (hES-MP002.5 cells) to normal human bone marrow-derived MSCs (BM-MSCs). hES-MP002.5 cells had lower yet reasonable CFU-F capacity compared with BM-MSC (8±3 versus 29±13 CFU-F per 100 cells). Both cell types showed similar immunophenotypic properties, i.e. cells were positive for CD105, CD73, CD166, HLA-ABC, CD44, CD146, CD90, and negative for CD45, CD34, CD14, CD31, CD117, CD19, CD 271, SSEA-4 and HLA-DR. hES-MP002.5 cells, like BM-MSCs, could be differentiated into adipocytes, osteoblasts and chondrocytes in vitro. Neither hES-MP002.5 cells nor BM-MSCs homed to the bone marrow of immune-deficient NSG mice following intravenous transplantation, whereas intra-femoral transplantation into NSG mice resulted in engraftment for both cell types. In vitro long-term culture-initiating cell assays and in vivo co-transplantation experiments with cord blood CD34+ hematopoietic cells demonstrated furthermore that hES-MP002.5 cells, like BM-MSCs, possess potent stroma support function. In contrast to BM-MSCs, however, hES-MP002.5 cells showed no or only little activity in mixed lymphocyte cultures and phytohemagglutinin (PHA) lymphocyte stimulation assays. In summary, ES-cell derived MSCs might be an attractive unlimited source for stroma transplantation approaches without suppressing immune function. PMID:23383153

  18. Solar abundances from gamma-ray spectroscopy - Comparisons with energetic particle, photospheric, and coronal abundances

    NASA Technical Reports Server (NTRS)

    Murphy, R. J.; Ramaty, R.; Reames, D. V.; Kozlovsky, B.

    1991-01-01

    Accelerated particle and ambient gas abundances have been derived using solar flare gamma-ray spectroscopy. The results with photospheric and coronal abundances, as well as with solar energetic particle abundances. This is the first time that the composition of accelerated particles interacting in an astrophysical source has been compared with the composition of particles escaping from the source. The analysis shows that the derived composition of the accelerated particles is different from the composition of particles observed in large proton flares; rather, it resembles the composition observed in He-3-rich flares. The analysis also suggests an ambient gas composition which differs from the composition of both the photosphere and the corona.

  19. Deuterium Abundance in Consciousness and Current Cosmology

    NASA Astrophysics Data System (ADS)

    Rauscher, Elizabeth A.

    We utilize the deuterium-hydrogen abundances and their role in setting limits on the mass and other conditions of cosmogenesis and cosmological evolution. We calculate the dependence of a set of physical variables such as density, temperature, energy mass, entropy and other physical variable parameters through the evolution of the universe under the Schwarzschild conditions as a function from early to present time. Reconciliation with the 3°K and missing mass is made. We first examine the Schwarzschild condition; second, the geometrical constraints of a multidimensional Cartesian space on closed cosmologies, and third we will consider the cosmogenesis and evolution of the universe in a multidimensional Cartesian space, obeying the Schwarzschild condition. Implications of this model for matter creation are made. We also examine experimental evidence for closed versus open cosmologies; x-ray detection of the "missing mass" density. Also the interstellar deuterium abundance, along with the value of the Hubble constant set a general criterion on the value of the curvature constant, k. Once the value of the Hubble constant, H is determined, the deuterium abundance sets stringent restrictions on the value of the curvature constant k by an detailed discussion is presented. The experimental evidences for the determination of H and the primary set of coupled equations to determine D abundance is given. 'The value of k for an open, closed, or flat universe will be discussed in terms of the D abundance which will affect the interpretation of the Schwarzschild, black hole universe. We determine cosmology solutions to Einstein's field obeying the Schwarzschild solutions condition. With this model, we can form a reconciliation of the black hole, from galactic to cosmological scale. Continuous creation occurs at the dynamic blackhole plasma field. We term this new model the multiple big bang or "little whimper model". We utilize the deuteriumhydrogen abundances and their role in

  20. Chemical abundance analysis of 19 barium stars

    NASA Astrophysics Data System (ADS)

    Yang, Guo-Chao; Liang, Yan-Chun; Spite, Monique; Chen, Yu-Qin; Zhao, Gang; Zhang, Bo; Liu, Guo-Qing; Liu, Yu-Juan; Liu, Nian; Deng, Li-Cai; Spite, Francois; Hill, Vanessa; Zhang, Cai-Xia

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures Teff, surface gravities log g, metallicity [Fe/H] and microturbulence velocity ξt) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants as indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their Na, Al, α- and iron-peak elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-capture) process elements relative to the Sun. Their median abundances of [Ba/Fe], [La/Fe] and [Eu/Fe] are 0.54, 0.65 and 0.40, respectively. The Y I and Zr I abundances are lower than Ba, La and Eu, but higher than the α- and iron-peak elements for the strong Ba stars and similar to the iron-peak elements for the mild stars. There exists a positive correlation between Ba intensity and [Ba/Fe]. For the n-capture elements (Y, Zr, Ba, La), there is an anti-correlation between their [X/Fe] and [Fe/H]. We identify nine of our sample stars as strong Ba stars with [Ba/Fe] >0.6 where seven of them have Ba intensity Ba=2-5, one has Ba=1.5 and another one has Ba=1.0. The remaining ten stars are classified as mild Ba stars with 0.17<[Ba/Fe] <0.54.

  1. Abundances from solar-flare gamma-ray line spectroscopy

    NASA Technical Reports Server (NTRS)

    Murphy, R. J.; Ramaty, R.; Forrest, D. J.; Kozlovsky, B.

    1985-01-01

    Elemental abundances of the ambient gas at the site of gamma ray line production inthe solar atmosphere are deduced using gamma ray line observations from a solar flare. The resultant abundances are different from local galactic abundances which are thought to be similar to photospheric abundances.

  2. Deuterium Abundance in the Local Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Ferlet, R.; Gry, C.; Vidal-Madjar, A.

    1984-01-01

    The present situation of deuterium abundance evaluation in interstellar space is discussed, and it is shown that it should be or = .00001 by studying in more detail lambda the Sco line of sight and by observing two NaI interstellar components toward that star, it can be shown that the D/H evaluation made toward lambda Sco is in fact related to the local interstellar medium (less than 10 pc from the Sun). Because this evaluation is also or = .00001 it is in striking contrast with the one made toward alpha Aur (D/H or = .000018 confirming the fact that the deuterium abundance in the local interstellar medium varies by at least a factor of two over few parsecs.

  3. THE OXYGEN ABUNDANCE IN THE SOLAR NEIGHBORHOOD

    SciTech Connect

    RodrIguez, Monica; Delgado-Inglada, Gloria E-mail: gloria@inaoep.mx

    2011-06-01

    We present a homogeneous analysis of the oxygen abundance in five H II regions and eight planetary nebulae (PNe) located at distances lower than 2 kpc and with available spectra of high quality. We find that both the collisionally excited lines (CELs) and recombination lines imply that the PNe are overabundant in oxygen by about 0.2 dex. An explanation that reconciles the oxygen abundances derived with CELs for H II regions and PNe with the values found for B stars, the Sun, and the diffuse interstellar medium (ISM) requires the presence in H II regions of an organic refractory dust component that is not present in PNe. This dust component has already been invoked to explain the depletion of oxygen in molecular clouds and in the diffuse ISM.

  4. Attenuation of species abundance distributions by sampling.

    PubMed

    Shimadzu, Hideyasu; Darnell, Ross

    2015-04-01

    Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used technique to reduce the amount of time and effort for investigating large quantities of biological samples. However, it is not immediately clear how (sub-)sampling affects the estimate of biodiversity aspects from a quantitative perspective. This paper specifies the effect of (sub-)sampling as attenuation of the species abundance distribution (SAD), and articulates how the sampling bias is induced to the SAD by random sampling. The framework presented also reveals some confusion in previous theoretical studies. PMID:26064626

  5. Attenuation of species abundance distributions by sampling

    PubMed Central

    Shimadzu, Hideyasu; Darnell, Ross

    2015-01-01

    Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used technique to reduce the amount of time and effort for investigating large quantities of biological samples. However, it is not immediately clear how (sub-)sampling affects the estimate of biodiversity aspects from a quantitative perspective. This paper specifies the effect of (sub-)sampling as attenuation of the species abundance distribution (SAD), and articulates how the sampling bias is induced to the SAD by random sampling. The framework presented also reveals some confusion in previous theoretical studies. PMID:26064626

  6. Solar abundances from gamma-ray spectroscopy

    NASA Technical Reports Server (NTRS)

    Ramaty, R.

    1989-01-01

    Determinations of solar abundances from gamma-ray line observations are reviewed. The principal results are: (1) in flare loops, at atmospheric heights betwen the transition region and the upper photosphere, the Mg/O ratio is higher by about a factor of 3 than in the photosphere, while the C/O ratio is essentially photospheric; (2) in the same region, the Ne/O ratio is higher by about a factor of 3 than the Ne/O ratio in the corona; (3) the photospheric He-3/H ratio is less than 0.000035. These results, combined with other data, suggest abundance variations in the solar atmosphere, possibly resulting from charge and mass dependent transport.

  7. Top consumer abundance influences lake methane efflux

    PubMed Central

    Devlin, Shawn P.; Saarenheimo, Jatta; Syväranta, Jari; Jones, Roger I.

    2015-01-01

    Lakes are important habitats for biogeochemical cycling of carbon. The organization and structure of aquatic communities influences the biogeochemical interactions between lakes and the atmosphere. Understanding how trophic structure regulates ecosystem functions and influences greenhouse gas efflux from lakes is critical to understanding global carbon cycling and climate change. With a whole-lake experiment in which a previously fishless lake was divided into two treatment basins where fish abundance was manipulated, we show how a trophic cascade from fish to microbes affects methane efflux to the atmosphere. Here, fish exert high grazing pressure and remove nearly all zooplankton. This reduction in zooplankton density increases the abundance of methanotrophic bacteria, which in turn reduce CH4 efflux rates by roughly 10 times. Given that globally there are millions of lakes emitting methane, an important greenhouse gas, our findings that aquatic trophic interactions significantly influence the biogeochemical cycle of methane has important implications. PMID:26531291

  8. Top consumer abundance influences lake methane efflux.

    PubMed

    Devlin, Shawn P; Saarenheimo, Jatta; Syväranta, Jari; Jones, Roger I

    2015-01-01

    Lakes are important habitats for biogeochemical cycling of carbon. The organization and structure of aquatic communities influences the biogeochemical interactions between lakes and the atmosphere. Understanding how trophic structure regulates ecosystem functions and influences greenhouse gas efflux from lakes is critical to understanding global carbon cycling and climate change. With a whole-lake experiment in which a previously fishless lake was divided into two treatment basins where fish abundance was manipulated, we show how a trophic cascade from fish to microbes affects methane efflux to the atmosphere. Here, fish exert high grazing pressure and remove nearly all zooplankton. This reduction in zooplankton density increases the abundance of methanotrophic bacteria, which in turn reduce CH4 efflux rates by roughly 10 times. Given that globally there are millions of lakes emitting methane, an important greenhouse gas, our findings that aquatic trophic interactions significantly influence the biogeochemical cycle of methane has important implications. PMID:26531291

  9. Helium abundance enhancements in the solar wind

    NASA Technical Reports Server (NTRS)

    Borrini, G.; Gosling, J. T.; Bame, S. J.; Feldman, W. C.

    1982-01-01

    Evidence for a link between helium enhancements at 1 AU and transient coronal mass ejections is provided by the statistical analysis of 73 large helium abundance enhancement observations made by IMPs 6, 7 and 8 over 1972-1978. These events, in which helium abundance enhancement is greater than about 10%, are sporadic, sometimes clustered in time, occur approximately in phase with the solar cycle, and nearly 50% of them are associated with interplanetary shocks and/or geomagnetic activity sudden commencements. The plasma pattern associated with them is nevertheless independent of shock occurrence, and features high magnetic field strength, low alpha-proton velocity difference, and low proton temperature, suggesting that the enhancement is embedded in a closed, magnetically dominated structure that expands adiabatically. Evidence of an association between helium enhancement at 1 AU and type II and IV radio bursts in the corona is presented.

  10. An unusual case of neurothekeoma of the arm in an adult.

    PubMed

    Bergamin, Federica; Gangemi, Ezio Nicola; Cerato, Claudia; Clemente, Alessandra; Borsetti, Marco; Suriani, Adolfo; Taraglio, Stefano

    2016-09-01

    Neurothekeomas are uncommon benign neoplasms with a peripheral nerve sheath origin. This tumor usually involves dermis and is described as a small, solitary, slow growing and reddish to flesh-colored nodule or papule. Neurothekeoma preferentially affects the central aspect of the face, the arms or shoulders of women in the second and third decades of life. This is the first case report of neurothekeoma involving the wrist developing from synovial tissue and with uncertain clinical behavior in an adult female. The tumor was completely excised under brachial plexus block. Histopathologically, the examination of the microscopic slides revealed the presence of a 20-mm diameter, well-circumscribed and multilobulated tumor composed of abundant myxoid stroma with cellular elements; with immunohistochemistry there was positivity to vimentin but S100-protein, epithelial membrane antigen, cytokeratin AE1-3, CD99 and CD34 were all negative. This pattern suggested a myxoid tumor form of neurothekeoma, mixed subtype. The patient had an atypical local recurrence and was re-operated after 3 months. After 12 months there was no evidence of clinical recurrences confirmed by magnetic resonance evaluation. Basically, our case report adds an important element in the correct clinical management of neurotecheomas: faced with a histological diagnosis with an unusual localization and mixed or hypercellular type, clinicians must consider the possibility of an early local recurrence, suggesting a close clinical and radiological follow-up. PMID:26577935

  11. Helium isotopic abundance variation in nature

    SciTech Connect

    Holden, N.E.

    1993-08-01

    The isotopic abundance of helium in nature has been reviewed. This atomic weight value is based on the value of helium in the atmosphere, which is invariant around the world and up to a distance of 100,000 feet. Helium does vary in natural gas, volcanic rocks and gases, ocean floor sediments, waters of various types and in radioactive minerals and ores due to {alpha} particle decay of radioactive nuclides.

  12. WIMP abundance and lepton (flavour) asymmetry

    SciTech Connect

    Stuke, Maik; Schwarz, Dominik J.; Starkman, Glenn E-mail: dschwarz@physik.uni-bielefeld.de

    2012-03-01

    We investigate how large lepton asymmetries affect the evolution of the early universe at times before big bang nucleosynthesis and in particular how they influence the relic density of WIMP dark matter. In comparison to the standard calculation of the relic WIMP abundance we find a decrease, depending on the lepton flavour asymmetry. We find an effect of up to 20 per cent for lepton flavour asymmetries l{sub f} = O(0.1)

  13. Primordial Li abundance and massive particles

    NASA Astrophysics Data System (ADS)

    ðapo, H.

    2012-10-01

    The problem of the observed lithium abundance coming from the Big Bang Nucleosynthesis is as of yet unsolved. One of the proposed solutions is including relic massive particles into the Big Bang Nucleosynthesis. We investigated the effects of such particles on 4HeX-+2H-->6Li+X-, where the X- is the negatively charged massive particle. We demonstrate the dominance of long-range part of the potential on the cross-section.

  14. Revised Thorium Abundances for Lunar Red Spots

    NASA Technical Reports Server (NTRS)

    Hagerty, J. J.; Lawrence, D. J.; Elphic, R. C.; Feldman, W. C.; Vaniman, D. T.; Hawke, B. R.

    2005-01-01

    Lunar red spots are features on the nearside of the Moon that are characterized by high albedo and by a strong absorption in the ultraviolet. These red spots include the Gruithuisen domes, the Mairan domes, Hansteen Alpha, the southern portion of Montes Riphaeus, Darney Chi and Tau, Helmet, and an area near the Lassell crater. It has been suggested that many of the red spots are extrusive, nonmare, volcanic features that could be composed of an evolved lithlogy enriched in thorium. In fact, Hawke et al. used morphological characteristics to show that Hansteen Alpha is a nonmare volcanic construct. However, because the apparent Th abundances (6 - 7 ppm) were lower than that expected for evolved rock types, Hawke et al. concluded that Hansteen Alpha was composed of an unknown rock type. Subsequent studies by Lawrence et al. used improved knowledge of the Th spatial distribution for small area features on the lunar surface to revisit the interpretation of Th abundances at the Hansteen Alpha red spot. As part of their study, Lawrence et al. used a forward modeling technique to show that the Th abundance at Hansteen Alpha is not 6 ppm, but is more likely closer to 25 ppm, a value consistent with evolved lithologies. This positive correlation between the morphology and composition of Hansteen Alpha provides support for the presence of evolved lithologies on the lunar surface. It is possible, however, that Hansteen Alpha represents an isolated occurrence of non-mare volcanism. That is why we have chosen to use the forward modeling technique of Lawrence et al. to investigate the Th abundances at other lunar red spots, starting with the Gruithuisen domes. Additional information is included in the original extended abstract.

  15. The primordial helium abundance from updated emissivities

    SciTech Connect

    Aver, Erik; Olive, Keith A.; Skillman, Evan D.; Porter, R.L. E-mail: olive@umn.edu E-mail: skillman@astro.umn.edu

    2013-11-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y{sub p}. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, and Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, and Stasi'nska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y{sub p}. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increased variance (due to additional objects included). From a regression to zero metallicity, we determine Y{sub p} = 0.2465 ± 0.0097, in good agreement with the BBN result, Y{sub p} = 0.2485 ± 0.0002, based on the Planck determination of the baryon density. In the future, a better understanding of why a large fraction of spectra are not well fit by the model will be crucial to achieving an increase in the precision of the primordial helium abundance determination.

  16. The shape of terrestrial abundance distributions.

    PubMed

    Alroy, John

    2015-09-01

    Ecologists widely accept that the distribution of abundances in most communities is fairly flat but heavily dominated by a few species. The reason for this is that species abundances are thought to follow certain theoretical distributions that predict such a pattern. However, previous studies have focused on either a few theoretical distributions or a few empirical distributions. I illustrate abundance patterns in 1055 samples of trees, bats, small terrestrial mammals, birds, lizards, frogs, ants, dung beetles, butterflies, and odonates. Five existing theoretical distributions make inaccurate predictions about the frequencies of the most common species and of the average species, and most of them fit the overall patterns poorly, according to the maximum likelihood-related Kullback-Leibler divergence statistic. Instead, the data support a low-dominance distribution here called the "double geometric." Depending on the value of its two governing parameters, it may resemble either the geometric series distribution or the lognormal series distribution. However, unlike any other model, it assumes both that richness is finite and that species compete unequally for resources in a two-dimensional niche landscape, which implies that niche breadths are variable and that trait distributions are neither arrayed along a single dimension nor randomly associated. The hypothesis that niche space is multidimensional helps to explain how numerous species can coexist despite interacting strongly. PMID:26601249

  17. The shape of terrestrial abundance distributions

    PubMed Central

    Alroy, John

    2015-01-01

    Ecologists widely accept that the distribution of abundances in most communities is fairly flat but heavily dominated by a few species. The reason for this is that species abundances are thought to follow certain theoretical distributions that predict such a pattern. However, previous studies have focused on either a few theoretical distributions or a few empirical distributions. I illustrate abundance patterns in 1055 samples of trees, bats, small terrestrial mammals, birds, lizards, frogs, ants, dung beetles, butterflies, and odonates. Five existing theoretical distributions make inaccurate predictions about the frequencies of the most common species and of the average species, and most of them fit the overall patterns poorly, according to the maximum likelihood–related Kullback-Leibler divergence statistic. Instead, the data support a low-dominance distribution here called the “double geometric.” Depending on the value of its two governing parameters, it may resemble either the geometric series distribution or the lognormal series distribution. However, unlike any other model, it assumes both that richness is finite and that species compete unequally for resources in a two-dimensional niche landscape, which implies that niche breadths are variable and that trait distributions are neither arrayed along a single dimension nor randomly associated. The hypothesis that niche space is multidimensional helps to explain how numerous species can coexist despite interacting strongly. PMID:26601249

  18. How selection structures species abundance distributions

    PubMed Central

    Magurran, Anne E.; Henderson, Peter A.

    2012-01-01

    How do species divide resources to produce the characteristic species abundance distributions seen in nature? One way to resolve this problem is to examine how the biomass (or capacity) of the spatial guilds that combine to produce an abundance distribution is allocated among species. Here we argue that selection on body size varies across guilds occupying spatially distinct habitats. Using an exceptionally well-characterized estuarine fish community, we show that biomass is concentrated in large bodied species in guilds where habitat structure provides protection from predators, but not in those guilds associated with open habitats and where safety in numbers is a mechanism for reducing predation risk. We further demonstrate that while there is temporal turnover in the abundances and identities of species that comprise these guilds, guild rank order is conserved across our 30-year time series. These results demonstrate that ecological communities are not randomly assembled but can be decomposed into guilds where capacity is predictably allocated among species. PMID:22787020

  19. Fluorine Abundances in the Milky Way Bulge

    NASA Astrophysics Data System (ADS)

    Cunha, Katia; Smith, Verne V.; Gibson, Brad K.

    2008-05-01

    Fluorine (19F) abundances are derived in a sample of six bulge red giants in Baade's window. These giants span a factor of 10 in metallicity, and this is the first study to define the behavior of 19F with metallicity in the bulge. The bulge results show an increase in F/O with increasing oxygen. This trend overlaps what is found in the disk at comparable metallicities, with the most oxygen-rich bulge target extending the disk trend. The increase in F/O in the disk arises from 19F synthesis in both asymptotic giant branch (AGB) stars and metal-rich Wolf-Rayet (WR) stars through stellar winds. The lack of an s-process enhancement in the most fluorine-rich bulge giant in this study suggests that WR stars represented a larger contribution than did AGB stars to 19F production in the bulge, when compared to the disk. If this result for fluorine is combined with the previously published overall decline in the O/Mg abundance ratios in metal-rich bulge stars, it suggests that WR winds played a role in shaping chemical evolution in the bulge. One star in this study exhibits a very low value of F/O while having a large O abundance; this chemical mixture can be understood if this star formed from gas that was enriched by metal-poor core-collapse supernovae, and it may indicate that chemical evolution in the bulge was inhomogeneous.

  20. Distribution and Abundance of Mars' Atmospheric Argon

    NASA Technical Reports Server (NTRS)

    Sprague, A. L.; Boynton, W. V.; Kerry, K. E.; Nelli, Steven; Murphy, Jim; Reedy, R. C.; Metzger, A. E.; Hunten, D. M.; Janes, K. D.; Crombie, M. K.

    2005-01-01

    One and one half Mars years (MY 26 and 27) of atmospheric Argon measurements are described and studied in the context of understanding how Argon, a minor constituent of Mars atmosphere that does not condense at Mars temperatures, can be used to study martian circulation and dynamics. Argon data are from the 2001 Mars Odyssey Gamma Subsystem (GS) of the suite of three instruments comprising the Gamma Ray Spectrometer (GRS). A comprehensive data analysis including gamma-ray production and attenuation by the atmosphere is included. Of particular interest is the enhanced abundance of Ar over the observed Ar abundance at lower latitudes at south (up to a factor of 10) and north (up to a factor of 4) polar regions during winter. Calibration of the measurements to actual Ar abundance is possible because GS measurements cover the same latitude and season as measurements made by the gas chromatograph mass spectrometer (GCMS) on Viking Landers 1 and 2 (VL1 and VL2). [2].

  1. Elemental abundances of solar sibling candidates

    SciTech Connect

    Ramírez, I.; Lambert, D. L.; Endl, M.; Cochran, W. D.; MacQueen, P. J.; Bajkova, A. T.; Bobylev, V. V.; Wittenmyer, R. A.

    2014-06-01

    Dynamical information along with survey data on metallicity and in some cases age have been used recently by some authors to search for candidates of stars that were born in the cluster where the Sun formed. We have acquired high-resolution, high signal-to-noise ratio spectra for 30 of these objects to determine, using detailed elemental abundance analysis, if they could be true solar siblings. Only two of the candidates are found to have solar chemical composition. Updated modeling of the stars' past orbits in a realistic Galactic potential reveals that one of them, HD 162826, satisfies both chemical and dynamical conditions for being a sibling of the Sun. Measurements of rare-element abundances for this star further confirm its solar composition, with the only possible exception of Sm. Analysis of long-term high-precision radial velocity data rules out the presence of hot Jupiters and confirms that this star is not in a binary system. We find that chemical tagging does not necessarily benefit from studying as many elements as possible but instead from identifying and carefully measuring the abundances of those elements that show large star-to-star scatter at a given metallicity. Future searches employing data products from ongoing massive astrometric and spectroscopic surveys can be optimized by acknowledging this fact.

  2. THE CORONAL ABUNDANCE ANOMALIES OF M DWARFS

    SciTech Connect

    Wood, Brian E.; Laming, J. Martin; Karovska, Margarita

    2012-07-01

    We analyze Chandra X-ray spectra of the M0 V+M0 V binary GJ 338. As quantified by X-ray surface flux, these are the most inactive M dwarfs ever observed with X-ray grating spectroscopy. We focus on measuring coronal abundances, in particular searching for evidence of abundance anomalies related to first ionization potential (FIP). In the solar corona and wind, low-FIP elements are overabundant, which is the so-called FIP effect. For other stars, particularly very active ones, an 'inverse FIP effect' is often observed, with low-FIP elements being underabundant. For both members of the GJ 338 binary, we find evidence for a modest inverse FIP effect, consistent with expectations from a previously reported correlation between spectral type and FIP bias. This amounts to strong evidence that all M dwarfs should exhibit the inverse FIP effect phenomenon, not just the active ones. We take the first step toward modeling the inverse FIP phenomenon in M dwarfs, building on past work that has demonstrated that MHD waves coursing through coronal loops can lead to a ponderomotive force that fractionates elements in a manner consistent with the FIP effect. We demonstrate that in certain circumstances this model can also lead to an inverse FIP effect, pointing the way to more detailed modeling of M dwarf coronal abundances in the future.

  3. The Coronal Abundance Anomalies of M Dwarfs

    NASA Astrophysics Data System (ADS)

    Wood, Brian E.; Laming, J. Martin; Karovska, Margarita

    2012-07-01

    We analyze Chandra X-ray spectra of the M0 V+M0 V binary GJ 338. As quantified by X-ray surface flux, these are the most inactive M dwarfs ever observed with X-ray grating spectroscopy. We focus on measuring coronal abundances, in particular searching for evidence of abundance anomalies related to first ionization potential (FIP). In the solar corona and wind, low-FIP elements are overabundant, which is the so-called FIP effect. For other stars, particularly very active ones, an "inverse FIP effect" is often observed, with low-FIP elements being underabundant. For both members of the GJ 338 binary, we find evidence for a modest inverse FIP effect, consistent with expectations from a previously reported correlation between spectral type and FIP bias. This amounts to strong evidence that all M dwarfs should exhibit the inverse FIP effect phenomenon, not just the active ones. We take the first step toward modeling the inverse FIP phenomenon in M dwarfs, building on past work that has demonstrated that MHD waves coursing through coronal loops can lead to a ponderomotive force that fractionates elements in a manner consistent with the FIP effect. We demonstrate that in certain circumstances this model can also lead to an inverse FIP effect, pointing the way to more detailed modeling of M dwarf coronal abundances in the future.

  4. Aerial survey estimates of fallow deer abundance

    USGS Publications Warehouse

    Gogan, Peter J.; Gates, Natalie B.; Lubow, Bruce C.; Pettit, Suzanne

    2012-01-01

    Reliable estimates of the distribution and abundance of an ungulate species is essential prior to establishing and implementing a management program. We used ground surveys to determine distribution and ground and aerial surveys and individually marked deer to estimate the abundance of fallow deer (Dama dama) in north-coastal California. Fallow deer had limited distribution and heterogeneous densities. Estimated post-rut densities across 4 annual surveys ranged from a low of 1.4 (SE=0.2) deer/km2 to a high of 3.3 (se=0.5) deer/km2 in a low density stratum and from 49.0 (SE=8.3) deer/km2 to 111.6 deer/km2 in a high density stratum. Sightability was positively influenced by the presence of white color-phase deer in a group and group size, and varied between airial and ground-based observers and by density strata. Our findings underscore the utility of double-observer surveys and aerial surveys with individually marked deer, both incorporating covariates to model sightability, to estimate deer abundance.

  5. Environmental factors shaping ungulate abundances in Poland.

    PubMed

    Borowik, Tomasz; Cornulier, Thomas; Jędrzejewska, Bogumiła

    2013-01-01

    Population densities of large herbivores are determined by the diverse effects of density-dependent and independent environmental factors. In this study, we used the official 1998-2003 inventory data on ungulate numbers from 462 forest districts and 23 national parks across Poland to determine the roles of various environmental factors in shaping country-wide spatial patterns of ungulate abundances. Spatially explicit generalized additive mixed models showed that different sets of environmental variables explained 39 to 50 % of the variation in red deer Cervus elaphus, wild boar Sus scrofa, and roe deer Capreolus capreolus abundances. For all of the studied species, low forest cover and the mean January temperature were the most important factors limiting their numbers. Woodland cover above 40-50 % held the highest densities for these species. Wild boar and roe deer were more numerous in deciduous or mixed woodlands within a matrix of arable land. Furthermore, we found significant positive effects of marshes and water bodies on wild boar abundances. A juxtaposition of obtained results with ongoing environmental changes (global warming, increase in forest cover) may indicate future growth in ungulate distributions and numbers. PMID:24244044

  6. Beryllium and Boron abundances in population II stars

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The scientific focus of this program was to undertake UV spectroscopic abundance analyses of extremely metal poor stars with attention to determining abundances of light elements such as beryllium and boron. The abundances are likely to reflect primordial abundances within the early galaxy and help to constrain models for early galactic nucleosynthesis. The general metal abundances of these stars are also important for understanding stellar evolution.

  7. Abundant Solar Nebula Solids in Comets

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Keller, L. P.; Nakamura-Messenger, K.; Nguyen, A. N.; Clemett, S.

    2016-01-01

    Comets have been proposed to consist of unprocessed interstellar materials together with a variable amount of thermally annealed interstellar grains. Recent studies of cometary solids in the laboratory have shown that comets instead consist of a wide range of materials from across the protoplanetary disk, in addition to a minor complement of interstellar materials. These advances were made possible by the return of direct samples of comet 81P/Wild 2 coma dust by the NASA Stardust mission and recent advances in microscale analytical techniques. Isotopic studies of 'cometary' chondritic porous interplanetary dust particles (CP-IDPs) and comet 81P/Wild 2 Stardust samples show that preserved interstellar materials are more abundant in comets than in any class of meteorite. Identified interstellar materials include sub-micron-sized presolar silicates, oxides, and SiC dust grains and some fraction of the organic material that binds the samples together. Presolar grain abundances reach 1 weight percentage in the most stardust-rich CP-IDPs, 50 times greater than in meteorites. Yet, order of magnitude variations in presolar grain abundances among CP-IDPs suggest cometary solids experienced significant variations in the degree of processing in the solar nebula. Comets contain a surprisingly high abundance of nebular solids formed or altered at high temperatures. Comet 81P/Wild 2 samples include 10-40 micron-sized, refractory Ca- Al-rich inclusion (CAI)-, chondrule-, and ameboid olivine aggregate (AOA)-like materials. The O isotopic compositions of these refractory materials are remarkably similar to their meteoritic counterparts, ranging from 5 percent enrichments in (sup 16) O to near-terrestrial values. Comet 81P/Wild 2 and CP-IDPs also contain abundant Mg-Fe crystalline and amorphous silicates whose O isotopic compositions are also consistent with Solar System origins. Unlike meteorites, that are dominated by locally-produced materials, comets appear to be composed of

  8. Bringing abundance into environmental politics: Constructing a Zionist network of water abundance, immigration, and colonization.

    PubMed

    Alatout, Samer

    2009-06-01

    For more than five decades, resource scarcity has been the lead story in debates over environmental politics. More importantly, and whenever environmental politics implies conflict, resource scarcity is constructed as the culprit. Abundance of resources, if at all visited in the literature, holds less importance. Resource abundance is seen, at best, as the other side of scarcity--maybe the successful conclusion of multiple interventions that may turn scarcity into abundance. This paper reinstates abundance as a politico-environmental category in its own right. Rather than relegating abundance to a second-order environmental actor that matters only on occasion, this paper foregrounds it as a crucial element in modern environmental politics. On the substantive level, and using insights from science and technology studies, especially a slightly modified actor-network framework, I describe the emergence and consolidation of a Zionist network of abundance, immigration, and colonization in Palestine between 1918 and 1948. The essential argument here is that water abundance was constructed as fact, and became a political rallying point around which a techno-political network emerged that included a great number of elements. To name just a few, the following were enrolled in the service of such a network: geologists, geophysicists, Zionist settlement experts, Zionist organizations, political and technical categories of all sorts, Palestinians as the negated others, Palestinian revolts in search of political rights, the British Mandate authorities, the hydrological system of Palestine, and the absorptive capacity of Palestine, among others. The point was to successfully articulate these disparate elements into a network that seeks opening Palestine for Jewish immigration, redefining Palestinian geography and history through Judeo-Christian Biblical narratives, and, in the process, de-legitimizing political Palestinian presence in historic Palestine. PMID:19848183

  9. Carbon and oxygen abundances in stellar populations

    NASA Astrophysics Data System (ADS)

    Nissen, P. E.; Chen, Y. Q.; Carigi, L.; Schuster, W. J.; Zhao, G.

    2014-08-01

    Context. Carbon and oxygen abundances in stars are important in many fields of astrophysics including nucleosynthesis, stellar structure, evolution of galaxies, and formation of planetary systems. Still, our knowledge of the abundances of these elements in different stellar populations is uncertain because of difficulties in observing and analyzing atomic and molecular lines of C and O. Aims: Abundances of C, O, and Fe are determined for F and G main-sequence stars in the solar neighborhood with metallicities in the range -1.6 < [Fe/H] < +0.4 in order to study trends and possible systematic differences in the C/Fe, O/Fe, and C/O ratios for thin- and thick-disk stars as well as high- and low-alpha halo stars. In addition, we investigate if there is any connection between C and O abundances in stellar atmospheres and the occurrence of planets. Methods: Carbon abundances are determined from the λλ 5052,5380 C i lines and oxygen abundances from the λ7774 O i triplet and the forbidden [O i] line at 6300 Å. MARCS model atmospheres are applied and non-LTE corrections for the O i triplet are included. Results: Systematic differences between high- and low-alpha halo stars and between thin- and thick-disk stars are seen in the trends of [C/Fe] and [O/Fe]. The two halo populations and thick-disk stars show the same trend of [C/O] versus [O/H], whereas the thin-disk stars are shifted to higher [C/O] values. Furthermore, we find some evidence of higher C/O and C/Fe ratios in stars hosting planets than in stars for which no planets have been detected. Conclusions: The results suggest that C and O in both high- and low-alpha halo stars and in thick-disk stars are made mainly in massive (M> 8 M⊙) stars, whereas thin-disk stars have an additional carbon contribution from low-mass AGB and massive stars of high metallicity causing a rising trend of the C/O ratio with increasing metallicity. However, at the highest metallicities investigated ([Fe/H] ≃ + 0.4), C/O does not

  10. Abundance anomalies in tidal disruption events

    NASA Astrophysics Data System (ADS)

    Kochanek, C. S.

    2016-05-01

    The ˜10 per cent of tidal disruption events (TDEs) due to stars more massive than M* ≳ M⊙ should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ˜25 per cent on average because it becomes inaccessible once it is sequestered in the high-density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main-sequence star can be enhanced in helium by factors of 2-3 for debris at a common orbital period. These helium abundance variations may be a contributor to the observed diversity of hydrogen and helium line strengths in TDEs. A still more striking anomaly is the rapid enhancement of nitrogen and the depletion of carbon due to the CNO cycle - stars with M* ≳ M⊙ quickly show an increase in their average N/C ratio by factors of 3-10. Because low-mass stars evolve slowly and high-mass stars are rare, TDEs showing high N/C will almost all be due to ˜1-2 M⊙ stars disrupted on the main sequence. Like helium, portions of the debris will show still larger changes in C and N, and the anomalies decline as the star leaves the main sequence. The enhanced [N/C] abundance ratio of these TDEs provides the first natural explanation for the rare, nitrogen-rich quasars and may also explain the strong nitrogen emission seen in ultraviolet spectra of ASASSN-14li.

  11. Primordial Li abundance and massive particles

    SciTech Connect

    Latin-Capital-Letter-Eth apo, H.

    2012-10-20

    The problem of the observed lithium abundance coming from the Big Bang Nucleosynthesis is as of yet unsolved. One of the proposed solutions is including relic massive particles into the Big Bang Nucleosynthesis. We investigated the effects of such particles on {sup 4}HeX{sup -}+{sup 2}H{yields}{sup 6}Li+X{sup -}, where the X{sup -} is the negatively charged massive particle. We demonstrate the dominance of long-range part of the potential on the cross-section.

  12. Abundances of Planetary Nebula NGC 5315

    NASA Technical Reports Server (NTRS)

    Pottasch, S. R.; Beintema, D. A.; Koorneef, J.; Salas, J. Bernard; Feibelman, W. A.; Oegerle, William R. (Technical Monitor)

    2002-01-01

    The ISO and IUE spectra of the elliptical nebula NGC 5315 is presented. These spectra axe combined with the spectra in the visual wavelength region to obtain a complete, extinction corrected, spectrum. The chemical composition of the nebulae is then calculated and compared to previous determinations. The HST Nicmos observations of the nebula in 3 emission lines are also presented. These observations are used to determine the helium abundance as a function of position in the nebula. A discussion is given of possible evolutionary effects.

  13. Chemical abundances in cold, dark interstellar clouds.

    PubMed

    Irvine, W M; Ohishi, M; Kaifu, N

    1991-05-01

    The Sun may well have formed in the type of interstellar cloud currently referred to as a cold, dark cloud. We present current tabulations of the totality of known interstellar molecules and of the subset which have been identified in cold clouds. Molecular abundances are given for two such clouds which show interesting chemical differences in spite of strong physical similarities, Taurus Molecular Cloud 1 (TMC-1) and Lynd's 134N (L134N, also referred to as L183). These regions may be at different evolutionary stages. PMID:11542208

  14. Chemical abundances in cold, dark interstellar clouds

    NASA Technical Reports Server (NTRS)

    Irvine, William M.; Kaifu, Norio; Ohishi, Masatoshi

    1991-01-01

    Current tabulations are presented of the entire range of known interstellar molecules, giving attention to that subset which has been identified in the cold, dark interstellar clouds out of which the sun has been suggested to have formed. The molecular abundances of two such clouds, Taurus Molecular Cloud 1 and Lynd's 134N, exhibit prepossessing chemical differences despite considerable physical similarities. This discrepancy may be accounted for by the two clouds' differing evolutionary stages. Two novel classes of interstellar molecules are noted: sulfur-terminated carbon chains and silicon-terminated ones.

  15. Neon and Oxygen Abundances and Abundance Ratio in the Solar Corona

    NASA Astrophysics Data System (ADS)

    Landi, E.; Testa, P.

    2015-02-01

    In this work we determine the Ne/O abundance ratio from Solar and Heliospheric Observatory (SOHO)/Solar Ultraviolet Measurement of Emitted Radiation (SUMER) off-disk observations of quiescent streamers over the 1996-2008 period. We find that the Ne/O ratio is approximately constant over solar cycle 23 from 1996 to 2005, at a value of 0.099 ± 0.017 this value is lower than the transition region determinations from the quiet Sun used to infer the neon photospheric abundance from the oxygen photospheric abundance. Also, the Ne/O ratio we determined from SUMER is in excellent agreement with in situ determinations from ACE/SWICS. In 2005-2008, the Ne/O abundance ratio increased with time and reached 0.25 ± 0.05, following the same trend found in the slowest wind analyzed by ACE/SWICS. Further, we measure the absolute abundance in the corona for both oxygen and neon from the data set of 1996 November 22, obtaining A o = 8.99 ± 0.04 and A Ne = 7.92 ± 0.03, and we find that both elements are affected by the first ionization potential (FIP) effect, with oxygen being enhanced by a factor of 1.4-2.1 over its photospheric abundance, and neon being changed by a factor of 0.75-1.20. We conclude that the Ne/O ratio is not constant in the solar atmosphere, both in time and at different heights, and that it cannot be reliably used to infer the neon abundance in the photosphere. Also, we argue that the FIP effect was less effective during the minimum of solar cycle 24, and that the Ne/O = 0.25 ± 0.05 value measured at that time is closer to the true photospheric value, leading to a neon photospheric abundance larger than assumed by ≈40%. We discuss the implications of these results for the solar abundance problem, for the FIP effect, and for the identification of the source regions of the solar wind.

  16. Non-Additive Effects of Genotypic Diversity Increase Floral Abundance and Abundance of Floral Visitors

    PubMed Central

    Genung, Mark A.; Lessard, Jean-Philippe; Brown, Claire B.; Bunn, Windy A.; Cregger, Melissa A.; Reynolds, Wm. Nicholas; Felker-Quinn, Emmi; Stevenson, Mary L.; Hartley, Amanda S.; Crutsinger, Gregory M.; Schweitzer, Jennifer A.; Bailey, Joseph K.

    2010-01-01

    Background In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. Methodology/Principal Findings Using an experimental common garden that manipulated genotypic diversity (the number of distinct genotypes per plot) of Solidago altissima, we document that genotypic diversity of a dominant plant can indirectly influence flower visitor abundance. Across two years, we found that 1) plant genotype explained 45% and 92% of the variation in flower visitor abundance in 2007 and 2008, respectively; and 2) plant genotypic diversity had a positive and non-additive effect on floral abundance and the abundance of flower visitors, as plots established with multiple genotypes produced 25% more flowers and received 45% more flower visits than would be expected under an additive model. Conclusions/Significance These results provide evidence that declines in genotypic diversity may be an important but little considered factor for understanding plant-pollinator dynamics, with implications for the global decline in pollinators due to reduced plant diversity in both agricultural and natural ecosystems. PMID:20090850

  17. Metal Abundances of KISS Galaxies. V. Nebular Abundances of 15 Intermediate Luminosity Star-forming Galaxies

    NASA Astrophysics Data System (ADS)

    Hirschauer, Alec S.; Salzer, John J.; Bresolin, Fabio; Saviane, Ivo; Yegorova, Irina

    2015-09-01

    We present high signal-to-noise ratio spectroscopy of 15 emission-line galaxies cataloged in the KPNO International Spectroscopic Survey, selected for their possession of high equivalent width [O iii] lines. The primary goal of this study was to attempt to derive direct-method (Te) abundances for use in constraining the upper-metallicity branch of the {R}23 relation. The spectra cover the full optical region from [O ii]λλ3726,3729 to [S iii]λλ9069,9531 and include the measurement of [O iii]λ4363 in 13 objects. From these spectra, we determine abundance ratios of helium, nitrogen, oxygen, neon, sulfur, and argon. We find these galaxies to predominantly possess oxygen abundances in the range of 8.0 ≲ 12+log(O/H) ≲ 8.3. We present a comparison of direct-method abundances with empirical strong-emission-line techniques, revealing several discrepancies. We also present a comparison of direct-method oxygen abundance calculations using electron temperatures determined from emission lines of O++ and S++, finding a small systematic shift to lower Te (∼1184 K) and higher metallicity (∼0.14 dex) for sulfur-derived Te compared to oxygen-derived Te. Finally, we explore in some detail the different spectral activity types of targets in our sample, including regular star-forming galaxies, those with suspected AGN contamination, and a local pair of low-metallicity, high-luminosity compact objects.

  18. Occupancy as a surrogate for abundance estimation

    USGS Publications Warehouse

    MacKenzie, D.I.; Nichols, J.D.

    2004-01-01

    In many monitoring programmes it may be prohibitively expensive to estimate the actual abundance of a bird species in a defined area, particularly at large spatial scales, or where birds occur at very low densities. Often it may be appropriate to consider the proportion of area occupied by the species as an alternative state variable. However, as with abundance estimation, issues of detectability must be taken into account in order to make accurate inferences: the non?detection of the species does not imply the species is genuinely absent. Here we review some recent modelling developments that permit unbiased estimation of the proportion of area occupied, colonization and local extinction probabilities. These methods allow for unequal sampling effort and enable covariate information on sampling locations to be incorporated. We also describe how these models could be extended to incorporate information from marked individuals, which would enable finer questions of population dynamics (such as turnover rate of nest sites by specific breeding pairs) to be addressed. We believe these models may be applicable to a wide range of bird species and may be useful for investigating various questions of ecological interest. For example, with respect to habitat quality, we might predict that a species is more likely to have higher local extinction probabilities, or higher turnover rates of specific breeding pairs, in poor quality habitats.

  19. Parameters and abundances in luminous stars

    SciTech Connect

    Earle Luck, R.

    2014-06-01

    Parameters and abundances for 451 stars of spectral types F, G, and K of luminosity classes I and II have been derived. Absolute magnitudes and E(B – V) have been derived for the warmer stars in order to investigate the galactic abundance gradient. The value found here: d[Fe/H]/dR ∼ –0.06 dex kpc{sup –1}, agrees well with previous determinations. Stellar evolution indicators have also been investigated with the derived C/O ratios indicating that standard CN processing has been operating. Perhaps the most surprising result found in these supposedly relatively young intermediate-mass stars is that both [O/Fe] and [C/Fe] show a correlation with [Fe/H] much the same as found in older populations. While the stars were selected based on luminosity class, there does exist a significant [Fe/H] range in the sample. The likely explanation of this is that there is a significant range in age in the sample; that is, some of the sample are low-mass red-giant stars with types that place them within the selection criteria.

  20. Elemental Abundances of Mercury-Manganese Stars

    NASA Astrophysics Data System (ADS)

    Adelman, Saul J.

    We propose to obtain a carefully planned set of multiple high dispersion exposures of three MercuryManganese stars in both the SWP and LWP cameras. These observations will be coadded to increase the S/N ratio so that accurate elemental abundances can be derived for these examples of HgMn stars, each of which represents some extreme class aspect. This will increase of sample of HgMn stars from four to seven. Of particular interest are the abundances of N and Co in which some HgMn stars have shown remarkable underabundances. Comparison of the UV and optical spectra features due to light elements such as N (and C and 0) provide an observational framework to test NLTE models such as those of Takada (1993). This work has already shed some light on some of earlier findings for normal stars. The ability to accurately determine the surface chemical composition of the late B stars through such studies will lead to better tests for theories purporting to explain the origin of the chemical peculiarities seen in this temperature domain.

  1. Absolute Abundance Measurements in Solar Flares

    NASA Astrophysics Data System (ADS)

    Warren, Harry

    2014-06-01

    We present measurements of elemental abundances in solar flares with EVE/SDO and EIS/Hinode. EVE observes both high temperature Fe emission lines Fe XV-XXIV and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (F). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is F=1.17+-0.22. Furthermore, we have compared the EVE measurements with corresponding flare observations of intermediate temperature S, Ar, Ca, and Fe emission lines taken with EIS. Our initial calculations also indicate a photospheric composition for these observations. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation in the non-flaring corona occurs.

  2. Measurements of Absolute Abundances in Solar Flares

    NASA Astrophysics Data System (ADS)

    Warren, Harry P.

    2014-05-01

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

  3. Genomic Repeat Abundances Contain Phylogenetic Signal

    PubMed Central

    Dodsworth, Steven; Chase, Mark W.; Kelly, Laura J.; Leitch, Ilia J.; Macas, Jiří; Novák, Petr; Piednoël, Mathieu; Weiss-Schneeweiss, Hanna; Leitch, Andrew R.

    2015-01-01

    A large proportion of genomic information, particularly repetitive elements, is usually ignored when researchers are using next-generation sequencing. Here we demonstrate the usefulness of this repetitive fraction in phylogenetic analyses, utilizing comparative graph-based clustering of next-generation sequence reads, which results in abundance estimates of different classes of genomic repeats. Phylogenetic trees are then inferred based on the genome-wide abundance of different repeat types treated as continuously varying characters; such repeats are scattered across chromosomes and in angiosperms can constitute a majority of nuclear genomic DNA. In six diverse examples, five angiosperms and one insect, this method provides generally well-supported relationships at interspecific and intergeneric levels that agree with results from more standard phylogenetic analyses of commonly used markers. We propose that this methodology may prove especially useful in groups where there is little genetic differentiation in standard phylogenetic markers. At the same time as providing data for phylogenetic inference, this method additionally yields a wealth of data for comparative studies of genome evolution. PMID:25261464

  4. MEASUREMENTS OF ABSOLUTE ABUNDANCES IN SOLAR FLARES

    SciTech Connect

    Warren, Harry P.

    2014-05-01

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

  5. ABUNDANCES OF GALACTIC ANTICENTER PLANETARY NEBULAE AND THE OXYGEN ABUNDANCE GRADIENT IN THE GALACTIC DISK

    SciTech Connect

    Henry, R. B. C.; Morrison, Michael A.; Kwitter, Karen B.; Jaskot, Anne E.; Balick, Bruce; Milingo, Jacquelynne B. E-mail: morrison@nhn.ou.ed E-mail: ajaskot@umich.ed E-mail: jmilingo@gettysburg.ed

    2010-11-20

    We have obtained spectrophotometric observations of 41 anticenter planetary nebulae (PNe) located in the disk of the Milky Way. Electron temperatures and densities, as well as chemical abundances for He, N, O, Ne, S, Cl, and Ar were determined. Incorporating these results into our existing database of PN abundances yielded a sample of 124 well-observed objects with homogeneously determined abundances extending from 0.9 to 21 kpc in galactocentric distance. We performed a detailed regression analysis which accounted for uncertainties in both oxygen abundances and radial distances in order to establish the metallicity gradient across the disk to be 12 + log(O/H) = (9.09 {+-} 0.05) - (0.058 {+-} 0.006) x R{sub g} , with R{sub g} in kpc. While we see some evidence that the gradient steepens at large galactocentric distances, more objects toward the anticenter need to be observed in order to confidently establish the true form of the metallicity gradient. We find no compelling evidence that the gradient differs between Peimbert Types I and II, nor is oxygen abundance related to the vertical distance from the galactic plane. Our gradient agrees well with analogous results for H II regions but is steeper than the one recently published by Stanghellini and Haywood over a similar range in galactocentric distance. A second analysis using PN distances from a different source implied a flatter gradient, and we suggest that we have reached a confusion limit which can only be resolved with greatly improved distance measurements and an understanding of the natural scatter in oxygen abundances.

  6. VLT spectroscopy of low-metallicity emission-line galaxies: abundance patterns and abundance discrepancies

    NASA Astrophysics Data System (ADS)

    Guseva, N. G.; Izotov, Y. I.; Stasińska, G.; Fricke, K. J.; Henkel, C.; Papaderos, P.

    2011-05-01

    Context. We present deep spectroscopy of a large sample of low-metallicity emission-line galaxies. Aims: The main goal of this study is to derive element abundances in these low-metallicity galaxies. Methods: We analyze 121 VLT spectra of H ii regions in 46 low-metallicity emission-line galaxies. Of these spectra 83 are archival VLT/FORS1+UVES spectra of H ii regions in 31 low-metallicity emission-line galaxies that are studied for the first time with standard direct methods to determine the electron temperatures, the electron number densities, and the chemical abundances. Results: The oxygen abundance of the sample lies in the range 12 + log O/H = 7.2-8.4. We confirm previous findings that Ne/O increases with increasing oxygen abundance, likely because of a higher depletion of oxygen in higher-metallicity galaxies. The Fe/O ratio decreases from roughly solar at the lowest metallicities to about one tenth of solar, indicating that the degree of depletion of iron into dust grains depends on metallicity. The N/O ratio in extremely low-metallicity galaxies with 12 + log O/H < 7.5 shows a slight increase with decreasing oxygen abundance, which could be the signature of enhanced production of primary nitrogen by rapidly rotating stars at low metallicity. We present the first empirical relation between the electron temperature derived from [S iii]λ6312/λ9069 or [N ii]λ5755/λ6583 and the one derived from [O iii]λ4363/λ(4959+5007) in low-metallicity galaxies. We also present an empirical relation between te derived from [O ii]λ3727/(λ7320 + λ7330) or [S ii]λ4068/(λ6717 + λ6730) and [O iii]λ4363/λ(4959+5007). The electron number densities Ne(Cl iii) and Ne(Ar iv) were derived in a number of objects and are found to be higher than Ne(O ii) and Ne(S ii). This has potential implications for the derivation of the pregalactic helium abundance. In a number of objects, the abundances of C++ and O++ could be derived from recombination lines. Our study confirms the

  7. The carbon monoxide abundance in interstellar clouds

    NASA Technical Reports Server (NTRS)

    Langer, W.

    1976-01-01

    The steady-state abundance of carbon monoxide in interstellar clouds is calculated as a function of optical depth, density, and temperature. The molecular reactions which lead to CO can be initiated by the following ion-molecule reactions: H(+) + O yields O(+) + H, C(+) + H2 yields CH2(+) + a photon, and H3(+) + C and O. As the ultraviolet radiation field is attenuated, C(+) is transformed primarily into CO and C I. There are characteristic column densities for the transition to CO corresponding to the optical depths for attenuating this field at different wavelengths. For thick, low-temperature clouds the attenuation of the fields which ionize carbon, sulfur, and heavy metals is important for CO production initiated by H3(+). Complete conversion to CO does not necessarily occur, and considerable neutral carbon may be expected even in optically thick clouds. Comparison of integrated column densities of CO with extinction are in reasonable agreement with observations.

  8. An Update of the Primordial Helium Abundance

    NASA Astrophysics Data System (ADS)

    Peimbert, Antonio; Peimbert, Manuel; Luridiana, Valentina

    2015-08-01

    Three of the best determinations of the primordial helium abundance (Yp) are those obtained from low metallicity HII regions by Aver, Olive, Porter, & Skillman (2013); Izotov, Thuan, & Guseva (2014); and Peimbert, Peimbert, & Luridiana (2007). In this poster we update the Yp determination by Peimbert et al. taking into account, among other aspects, recent advances in the determination of the He atomic physical parameters, the temperature structure, the collisional effects of high temperatures on the Balmer lines, as well as the effect of H and He bound-bound absorption.We compare our results with those of Aver et al. and Izotov et al. and point out possible explanations for the differences among the three determinations. We also compare our results with those obtained with the Plank satellite considering recent measurements of the neutron mean life; this comparison has implications on the determination of the number of light neutrino families.

  9. Element abundance ratios in stellar population modelling

    NASA Astrophysics Data System (ADS)

    Thomas, Daniel

    2015-04-01

    I review the implementation of the effects from varying chemical element abundance ratios in stellar population modelling, focusing on α- and Fe-peak elements. A brief overview of the development of such models over the past 30 years is provided, starting with early work on the identification of relevant absorption features in the spectra of early-type galaxies in the 1980s leading to the most recent developments of the past years. Recent highlights include the adoption of new flux calibrated libraries, the inclusion of a wide range of chemical elements, the calculation of error estimates on the model, and the consideration of element variation effects on full spectra. The calibration of such models with globular clusters and some key results on the element ratios measured in early-type galaxies are presented.

  10. Carbonate abundances and isotopic compositions in chondrites

    NASA Astrophysics Data System (ADS)

    Alexander, C. M. O'd.; Bowden, R.; Fogel, M. L.; Howard, K. T.

    2015-04-01

    We report the bulk C abundances, and C and O isotopic compositions of carbonates in 64 CM chondrites, 14 CR chondrites, 2 CI chondrites, LEW 85332 (C2), Kaba (CV3), and Semarkona (LL3.0). For the unheated CMs, the total ranges of carbonate isotopic compositions are δ13C ≈ 25-75‰ and δ18O ≈ 15-35‰, and bulk carbonate C contents range from 0.03 to 0.60 wt%. There is no simple correlation between carbonate abundance and isotopic composition, or between either of these parameters and the extent of alteration. Unless accretion was very heterogeneous, the uncorrelated variations in extent of alteration and carbonate abundance suggests that there was a period of open system behavior in the CM parent body, probably prior to or at the start of aqueous alteration. Most of the ranges in CM carbonate isotopic compositions can be explained by their formation at different temperatures (0-130 °C) from a single fluid in which the carbonate O isotopes were controlled by equilibrium with water (δ18O ≈ 5‰) and the C isotopes were controlled by equilibrium with CO and/or CH4 (δ13C ≈ -33‰ or -20‰ for CO- or CH4-dominated systems, respectively). However, carbonate formation would have to have been inefficient, otherwise carbonate compositions would have resembled those of the starting fluid. A quite similar fluid composition (δ18O ≈ -5.5‰, and δ13C ≈ -31‰ or -17‰ for CO- or CH4-dominated systems, respectively) can explain the carbonate compositions of the CIs, although the formation temperatures would have been lower (~10-40 °C) and the relative abundances of calcite and dolomite may play a more important role in determining bulk carbonate compositions than in the CMs. The CR carbonates exhibit a similar range of O isotopes, but an almost bimodal distribution of C isotopes between more (δ13C ≈ 65-80‰) and less altered samples (δ13C ≈ 30-40‰). This bimodality can still be explained by precipitation from fluids with the same isotopic

  11. Chemical abundances in the Galactic bulge

    NASA Astrophysics Data System (ADS)

    Zoccali, M.; Lecureur, A.; Hill, V.; Barbuy, B.; Renzini, A.; Minniti, D.; Gómez, A.; Ortolani, S.

    We spectroscopically characterize the Galactic Bulge to infer its star formation timescale, compared to the other Galactic components, through the chemical signature on its individual stars. O, Na, Mg, Al were obtained for 50 K giants in four fields towards the Galactic bulge from UVES spectra (R=45,000), while Fe was measured in more than 400 stars with a slightly low resolution (R=20,000) and the GIRAFFE spectrograph at VLT. Oxygen and Magnesium show a well defined trend with [Fe/H], with abundances larger than those measured in both thin and thick disk stars, supporting a scenario in which the bulge formed before and more rapidly than the disk. On the other hand the iron distribution peaks at solar metallicity and it is slightly narrower than that measured in previous works. Part of the present results have been published by \\citet{Zoccali06} and \\citet{Lecureur07}, and part will be discussed in forthcoming papers.

  12. Abundance of introduced species at home predicts abundance away in herbaceous grasslands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced versus native communities, because ecological or evolutionary based shifts in popula...

  13. Cosmological implications of light element abundances: theory.

    PubMed

    Schramm, D N

    1993-06-01

    Primordial nucleosynthesis provides (with the microwave background radiation) one of the two quantitative experimental tests of the hot Big Bang cosmological model (versus alternative explanations for the observed Hubble expansion). The standard homogeneous-isotropic calculation fits the light element abundances ranging from 1H at 76% and 4He at 24% by mass through 2H and 3He at parts in 105 down to 7Li at parts in 1010. It is also noted how the recent Large Electron Positron Collider (and Stanford Linear Collider) results on the number of neutrinos (Nnu) are a positive laboratory test of this standard Big Bang scenario. The possible alternate scenario of quark-hadron-induced inhomogeneities is also discussed. It is shown that when this alternative scenario is made to fit the observed abundances accurately, the resulting conclusions on the baryonic density relative to the critical density (Omegab) remain approximately the same as in the standard homogeneous case, thus adding to the robustness of the standard model and the conclusion that Omegab approximately 0.06. This latter point is the driving force behind the need for nonbaryonic dark matter (assuming total density Omegatotal = 1) and the need for dark baryonic matter, since the density of visible matter Omegavisible < Omegab. The recent Population II B and Be observations are also discussed and shown to be a consequence of cosmic ray spallation processes rather than primordial nucleosynthesis. The light elements and Nnu successfully probe the cosmological model at times as early as 1 sec and a temperature (T) of approximately 10(10) K (approximately 1 MeV). Thus, they provided the first quantitative arguments that led to the connections of cosmology to nuclear and particle physics. PMID:11607387

  14. Cosmological implications of light element abundances: theory.

    PubMed Central

    Schramm, D N

    1993-01-01

    Primordial nucleosynthesis provides (with the microwave background radiation) one of the two quantitative experimental tests of the hot Big Bang cosmological model (versus alternative explanations for the observed Hubble expansion). The standard homogeneous-isotropic calculation fits the light element abundances ranging from 1H at 76% and 4He at 24% by mass through 2H and 3He at parts in 105 down to 7Li at parts in 1010. It is also noted how the recent Large Electron Positron Collider (and Stanford Linear Collider) results on the number of neutrinos (Nnu) are a positive laboratory test of this standard Big Bang scenario. The possible alternate scenario of quark-hadron-induced inhomogeneities is also discussed. It is shown that when this alternative scenario is made to fit the observed abundances accurately, the resulting conclusions on the baryonic density relative to the critical density (Omegab) remain approximately the same as in the standard homogeneous case, thus adding to the robustness of the standard model and the conclusion that Omegab approximately 0.06. This latter point is the driving force behind the need for nonbaryonic dark matter (assuming total density Omegatotal = 1) and the need for dark baryonic matter, since the density of visible matter Omegavisible < Omegab. The recent Population II B and Be observations are also discussed and shown to be a consequence of cosmic ray spallation processes rather than primordial nucleosynthesis. The light elements and Nnu successfully probe the cosmological model at times as early as 1 sec and a temperature (T) of approximately 10(10) K (approximately 1 MeV). Thus, they provided the first quantitative arguments that led to the connections of cosmology to nuclear and particle physics. Images Fig. 2 PMID:11607387

  15. Earth abundant bimetallic nanoparticles for heterogeneous catalysis

    NASA Astrophysics Data System (ADS)

    Senn, Jonathan F., Jr.

    Polymer exchange membrane fuel cells have the potential to replace current fossil fuel-based technologies in terms of emissions and efficiency, but CO contamination of H2 fuel, which is derived from steam methane reforming, leads to system inefficiency or failure. Solutions currently under development are bimetallic nanoparticles comprised of earth-abundant metals in different architectures to reduce the concentration of CO by PROX during fuel cell operation. Chapter One introduces the Pt-Sn and Co-Ni bimetallic nanoparticle systems, and the intermetallic and core-shell architectures of interest for catalytic evaluation. Application, theory, and studies associated with the efficacy of these nanoparticles are briefly reviewed. Chapter Two describes the concepts of the synthetic and characterization methods used in this work. Chapter Three presents the synthetic, characterization, and catalytic findings of this research. Pt, PtSn, PtSn2, and Pt 3Sn nanoparticles have been synthesized and supported on gamma-Al2O3. Pt3Sn was shown to be an effective PROX catalyst in various gas feed conditions, such as the gas mixture incorporating 0.1% CO, which displayed a light-off temperatures of ˜95°C. Co and Ni monometallic and CoNi bimetallic nanoparticles have been synthesized and characterized, ultimately leading to the development of target Co Ni core-shell nanoparticles. Proposed studies of catalytic properties of these nanoparticles in preferential oxidation of CO (PROX) reactions will further elucidate the effects of different crystallographic phases, nanoparticle-support interactions, and architecture on catalysis, and provide fundamental understanding of catalysis with nanoparticles composed of earth abundant metals in different architectures.

  16. Halo abundances within the cosmic web

    NASA Astrophysics Data System (ADS)

    Alonso, D.; Eardley, E.; Peacock, J. A.

    2015-03-01

    We investigate the dependence of the mass function of dark-matter haloes on their environment within the cosmic web of large-scale structure. A dependence of the halo mass function on large-scale mean density is a standard element of cosmological theory, allowing mass-dependent biasing to be understood via the peak-background split. On the assumption of a Gaussian density field, this analysis can be extended to ask how the mass function depends on the geometrical environment: clusters, filaments, sheets and voids, as classified via the tidal tensor (the Hessian matrix of the gravitational potential). In linear theory, the problem can be solved exactly, and the result is attractively simple: the conditional mass function has no explicit dependence on the local tidal field, and is a function only of the local density on the filtering scale used to define the tidal tensor. There is nevertheless a strong implicit predicted dependence on geometrical environment, because the local density couples statistically to the derivatives of the potential. We compute the predictions of this model and study the limits of their validity by comparing them to results deduced empirically from N-body simulations. We have verified that, to a good approximation, the abundance of haloes in different environments depends only on their densities, and not on their tidal structure. In this sense we find relative differences between halo abundances in different environments with the same density which are smaller than ˜13 per cent. Furthermore, for sufficiently large filtering scales, the agreement with the theoretical prediction is good, although there are important deviations from the Gaussian prediction at small, non-linear scales. We discuss how to obtain improved predictions in this regime, using the `effective-universe' approach.

  17. Neon and Oxygen Abundances in M33

    NASA Astrophysics Data System (ADS)

    Crockett, Nathan R.; Garnett, Donald R.; Massey, Philip; Jacoby, George

    2006-02-01

    We present new spectroscopic observations of 13 H II regions in the Local Group spiral galaxy M33. The regions observed range from 1 to 7 kpc in distance from the nucleus. Of the 13 H II regions observed, the [O III] λ4363 line was detected in six regions. Electron temperatures were thus able to be determined directly from the spectra using the [O III] λλ4959, 5007/λ4363 line ratio. Based on these temperature measurements, oxygen and neon abundances and their radial gradients were calculated. For neon, a gradient of -0.016+/-0.017 dex kpc-1 was computed, which agrees with the Ne/H gradient derived previously from ISO spectra. A gradient of -0.012+/-0.011 dex kpc-1 was computed for O/H, much shallower than was derived in previous studies. The newly calculated O/H and Ne/H gradients are in much better agreement with each other, as expected from predictions of stellar nucleosynthesis. We examine the correlation between the WC/WN ratio and metallicity, and find that the new M33 abundances do not impact the observed correlation significantly. We also identify two new He II-emitting H II regions in M33, the first to be discovered in a spiral galaxy other than the Milky Way. In both cases the nebular He II emission is not associated with Wolf-Rayet stars. Therefore, caution is warranted in interpreting the relationship between nebular He II emission and Wolf-Rayet stars when both are observed in the integrated spectrum of an H II region.

  18. Dynamical implications of Jupiter's tropospheric ammonia abundance

    NASA Astrophysics Data System (ADS)

    Showman, Adam P.; de Pater, Imke

    2005-03-01

    Groundbased radio observations indicate that Jupiter's ammonia is globally depleted from 0.6 bars to at least 4-6 bars relative to the deep abundance of ˜3 times solar, a fact that has so far defied explanation. The observations also indicate that (i) the depletion is greater in belts than zones, and (ii) the greatest depletion occurs within Jupiter's local 5-μm hot spots, which have recently been detected at radio wavelengths. Here, we first show that both the global depletion and its belt-zone variation can be explained by a simple model for the interaction of moist convection with Jupiter's cloud-layer circulation. If the global depletion is dynamical in origin, then important endmember models for the belt-zone circulation can be ruled out. Next, we show that the radio observations of Jupiter's 5-μm hot spots imply that the equatorial wave inferred to cause hot spots induces vertical parcel oscillation of a factor of ˜2 in pressure near the 2-bar level, which places important constraints on hot-spot dynamics. Finally, using spatially resolved radio maps, we demonstrate that low-latitude features exceeding ˜4000 km diameter, such as the equatorial plumes and large vortices, are also depleted in ammonia from 0.6 bars to at least 2 bars relative to the deep abundance of 3 times solar. If any low-latitude features exist that contain 3-times-solar ammonia up to the 0.6-bar ammonia condensation level, they must have diameters less than ˜4000 km.

  19. Li-7 abundances in halo stars: Testing stellar evolution models and the primordial Li-7 abundance

    NASA Technical Reports Server (NTRS)

    Chaboyer, Brian; Demarque, P.

    1994-01-01

    A large number of stellar evolution models with (Fe/H) = -2.3 and -3.3 have been calculated in order to determine the primordial Li-7 abundance and to test current stellar evolution models by a comparison to the extensive database of accurate Li abundances in extremely metal-poor halo stars observed by Thorburn (1994). Standard models with gray atmospheres do a very good job of fitting the observed Li abundances in stars hotter than approximately 5600 K. They predict a primordial. Li-7 abundance of log N(Li) = 2.24 +/- 0.03. Models which include microscopic diffusion predict a downward curvature in the Li-7 destruction isochrones at hot temperatures which is not present in the observations. Thus, the observations clearly rule out models which include uninhibited microscopic diffusion of Li-7 from the surface of the star. Rotational mixing inhibits the microscopic diffusion and the (Fe/H) = -2.28 stellar models which include both diffusion and rotational mixing provide an excellent match to the mean trend in T(sub eff) which is present in the observations. Both the plateau stars and the heavily depleted cool stars are well fit by these models. The rotational mixing leads to considerable Li-7 depletion in these models and the primordial Li-7 abundance inferred from these models is log N(Li) = 3.08 +/- 0.1. However, the (Fe/H) = -3.28 isochrones reveal problems with the combined models. These isochrones predict a trend of decreasing log N(Li) with increasing T(sub eff) which is not present in the observations. Possible causes for this discrepancy are discussed.

  20. Li-7 abundances in halo stars: Testing stellar evolution models and the primordial Li-7 abundance

    NASA Astrophysics Data System (ADS)

    Chaboyer, Brian; Demarque, P.

    1994-10-01

    A large number of stellar evolution models with (Fe/H) = -2.3 and -3.3 have been calculated in order to determine the primordial Li-7 abundance and to test current stellar evolution models by a comparison to the extensive database of accurate Li abundances in extremely metal-poor halo stars observed by Thorburn (1994). Standard models with gray atmospheres do a very good job of fitting the observed Li abundances in stars hotter than approximately 5600 K. They predict a primordial. Li-7 abundance of log N(Li) = 2.24 +/- 0.03. Models which include microscopic diffusion predict a downward curvature in the Li-7 destruction isochrones at hot temperatures which is not present in the observations. Thus, the observations clearly rule out models which include uninhibited microscopic diffusion of Li-7 from the surface of the star. Rotational mixing inhibits the microscopic diffusion and the (Fe/H) = -2.28 stellar models which include both diffusion and rotational mixing provide an excellent match to the mean trend in Teff which is present in the observations. Both the plateau stars and the heavily depleted cool stars are well fit by these models. The rotational mixing leads to considerable Li-7 depletion in these models and the primordial Li-7 abundance inferred from these models is log N(Li) = 3.08 +/- 0.1. However, the (Fe/H) = -3.28 isochrones reveal problems with the combined models. These isochrones predict a trend of decreasing log N(Li) with increasing Teff which is not present in the observations. Possible causes for this discrepancy are discussed.

  1. Solar coronal and photospheric abundances from solar energetic particle measurements

    NASA Technical Reports Server (NTRS)

    Breneman, H. H.; Stone, E. C.

    1985-01-01

    Solar energetic particle (SEP) elemental abundance data from the cosmic ray subsystem (CRS) aboard the Voyager 1 and 2 spacecraft are used to derive unfractionated coronal and photospheric abundances for elements with Z = 6-30. It is found that the ionic charge-to-mass ratio (Q/M) is the principal organizing parameter for the fractionation of SEPs by acceleration and propagation processes and for flare-to-flare variability, making possible a single-parameter Q/M-dependent correction to the average SEP abundances to obtain unfractionated coronal abundances. A further correction based on first ionization potential allows the determination of unfractionated photospheric abundances.

  2. Solar Coronal and photospheric abundances from solar energetic particle measurements

    NASA Technical Reports Server (NTRS)

    Breneman, H.; Stone, E. C.

    1985-01-01

    Solar energetic particle (SEP) elemental abundance data from the cosmic ray subsystem (CRS) aboard the Voyager 1 and 2 spacecraft are used to derive unfractionated coronal and photospheric abundances for elements with 3 Z or = 30. It is found that the ionic charge-to-mass ratio (Q/M) is the principal organizing parameter for the fractionation of SEPs by acceleration and propagation processes and for flare-to-flare variability, making possible a single-parameter Q/M-dependent correction to the average SEP abundances to obtain unfractionated coronal abundances. A further correction based on first ionization potential allows the determination of unfractionated photospheric abundances.

  3. Solar coronal and photospheric abundances from solar energetic particle measurements

    NASA Technical Reports Server (NTRS)

    Breneman, H.; Stone, E. C.

    1985-01-01

    Solar energetic particle (SEP) elemental abundance data from the Cosmic Ray Subsystem (CRS) aboard the Voyager 1 and 2 spacecraft are used to derive unfractionated coronal and photospheric abundances for elements with 3 = or Z or = 30. The ionic charge-to-mass ratio (Q/M) is the principal organizing parameter for the fractionation of SEPs by acceleration and propagation processes and for flare-to-flare variability, making possible a single-parameter Q/M-dependent correction to the average SEP abundances to obtain unfractionated coronal abundances. A further correction based on first ionization potential allows the determination of unfractionated photospheric abundances.

  4. Elevated S100A9 expression in tumor stroma functions as an early recurrence marker for early-stage oral cancer patients through increased tumor cell invasion, angiogenesis, macrophage recruitment and interleukin-6 production

    PubMed Central

    Fang, Wei-Yu; Chen, Yi-Wen; Hsiao, Jenn-Ren; Liu, Chiang-Shin; Kuo, Yi-Zih; Wang, Yi-Ching; Chang, Kung-Chao; Tsai, Sen-Tien; Chang, Mei-Zhu; Lin, Siao-Han; Wu, Li-Wha

    2015-01-01

    S100A9 is a calcium-binding protein with two EF-hands and frequently deregulated in several cancer types, however, with no clear role in oral cancer. In this report, the expression of S100A9 in cancer and adjacent tissues from 79 early-stage oral cancer patients was detected by immunohistochemical staining. Although S100A9 protein was present in both tumor and stromal cells, only the early-stage oral cancer patients with high stromal expression had reduced recurrence-free survival. High stromal S100A9 expression was also significantly associated with non-well differentiation and recurrence. In addition to increasing cell migration and invasion, ectopic S100A9 expression in tumor cells promoted xenograft tumorigenesis as well as the dominant expression of myeloid cell markers and pro-inflammatory IL-6. The expression of S100A9 in one stromal component, monocytes, stimulated the aggressiveness of co-cultured oral cancer cells. We also detected the elevation of serum S100A9 levels in early-stage oral cancer patients of a separate cohort of 73 oral cancer patients. The release of S100A9 protein into extracellular milieu enhanced tumor cell invasion, transendothelial monocyte migration and angiogenic activity. S100A9-mediated release of IL-6 requires the crosstalk of tumor cells with monocytes through the activation of NF-κB and STAT-3. Early-stage oral cancer patients with both high S100A9 expression and high CD68+ immune infiltrates in stroma had shortest recurrence-free survival, suggesting the use of both S100A9 and CD68 as poor prognostic markers for oral cancer. Together, both intracellular and extracellular S100A9 exerts a tumor-promoting action through the activation of oral cancer cells and their associated stroma in oral carcinogenesis. PMID:26315114

  5. Manganese abundances in Galactic bulge red giants

    NASA Astrophysics Data System (ADS)

    Barbuy, B.; Hill, V.; Zoccali, M.; Minniti, D.; Renzini, A.; Ortolani, S.; Gómez, A.; Trevisan, M.; Dutra, N.

    2013-11-01

    Context. Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut between the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy. Manganese is also produced in type Ia SNe. Aims: The aim of this work is the study of abundances of the iron-peak element Mn in 56 bulge giants, among which 13 are red clump stars. Four bulge fields along the minor axis are inspected. The study of abundances of Mn-over-Fe as a function of metallicity in the Galactic bulge may shed light on its production mechanisms. Methods: High-resolution spectra were obtained using the FLAMES+UVES spectrograph on the Very Large Telescope. The spectra were obtained within a program to observe 800 stars using the GIRAFFE spectrograph, together with the present UVES spectra. Results: We aim at identifying the chemical evolution of manganese, as a function of metallicity, in the Galactic bulge. We find [Mn/Fe] ~ -0.7 at [Fe/H] ~ -1.3, increasing to a solar value at metallicities close to solar, and showing a spread around - 0.7 ≲ [Fe/H] ≲ -0.2, in good agreement with other work on Mn in bulge stars. There is also good agreement with chemical evolution models. We find no clear difference in the behaviour of the four bulge fields. Whereas [Mn/Fe] vs. [Fe/H] could be identified with the behaviour of the thick disc stars, [Mn/O] vs. [O/H] has a behaviour running parallel, at higher metallicities, compared to thick disc stars, indicating that the bulge enrichment might have proceeded differently from that of the thick disc. Observations collected at the European Southern Observatory, Paranal, Chile (ESO programmes 71.B-0617A, 73.B0074A, and GTO 71.B-0196).Tables 1-6 and Figs. 1-6 are available in electronic form at http://www.aanda.org

  6. Large Silicon Abundance in Photodissociation Regions

    NASA Astrophysics Data System (ADS)

    Okada, Yoko; Onaka, Takashi; Nakagawa, Takao; Shibai, Hiroshi; Tomono, Daigo; Yui, Yukari Y.

    2006-03-01

    We have made one-dimensional raster scan observations of the ρ Oph and σ Sco star-forming regions with two spectrometers (SWS and LWS) on board the ISO. In the ρ Oph region, [Si II] 35 μm, [O I] 63 μm, 146 μm, [C II] 158 μm, and the H2 pure rotational transition lines S(0) to S(3) are detected, and the photodissociation region (PDR) properties are derived as the radiation field scaled by the solar neighborhood value G0~30-500, the gas density n~250-2500 cm-3, and the surface temperature T~100-400 K. The ratio of [Si II] 35 μm to [O I] 146 μm indicates that silicon of 10%-20% of the solar abundance must be in the gaseous form in the PDR, suggesting that efficient dust destruction is ongoing even in the PDR and that a fraction of the silicon atoms may be contained in volatile forms in dust grains. The [O I] 63 μm and [C II] 158 μm emissions are too weak relative to [O I] 146 μm to be accounted for by standard PDR models. We propose a simple model, in which overlapping PDR clouds along the line of sight absorb the [O I] 63 μm and [C II] 158 μm emissions, and show that the proposed model reproduces the observed line intensities fairly well. In the σ Sco region, we have detected three fine-structure lines, [O I] 63 μm, [N II] 122 μm, and [C II] 158 μm, and derived that 30%-80% of the [C II] emission comes from the ionized gas. The upper limit of the [Si II] 35 μm is compatible with the solar abundance relative to nitrogen, and no useful constraint on the gaseous Si is obtained for the σ Sco region. Based on observations with ISO, an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, the Netherlands, and the UK) and with the participation of ISAS and NASA.

  7. Metallic abundances of the 2002 Leonid

    NASA Astrophysics Data System (ADS)

    Kasuga, T.; Yamamoto, T.; Watanabe, J.; Yano, H.

    spectra, time variation of the abundances of metallic atoms and of their electronic excitation temperature were obtained. In this meeting, we will discuss the metallic abundances of the 2001 and 2002 Leonid meteors and the possibility of the delivery mechanism of OH and CN (387.9 nm B2Σ+ - X2π) from the comet. The discussion of the possibility of the volatile element is one of the interesting subjects of the meteor.

  8. High Abundance of Ions in Cosmic Ices

    NASA Technical Reports Server (NTRS)

    Gudipati, Murthy S.; Allamandola, Louis J.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Water-rich, mixed molecular ices and polycyclic aromatic hydrocarbons (PAHs) are common throughout interstellar molecular clouds and the Solar System. Vacuum ultraviolet (VUV) irradiation and particle bombardment of these abiotic ices produces complex organic species, including important biogenic molecules such as amino acids and functionalized PAHs which may have played a role in the origin of life. This ability of such water-rich, oxygen dominated ices to promote production of complex organic species is surprising and points to an important, unusual, but previously overlooked mechanism at play within the ice. Here we report the nature of this mechanism using electronic spectroscopy. VUV-irradiation of PAH/H2O ices leads to an unprecedented and efficient (greater than 70 %) conversion of the neutral PAHs to their cation form (PAH+). Further, these H2O/PAH+ ices are stabile at temperatures below 50 K, a temperature domain common throughout interstellar clouds and the Solar System. Between 50 and 125 K they react to form the complex organics. In view of this, we conclude that charged PAHs and other molecular ions should be common and abundant in many cosmic ices. The chemical, spectroscopic and physical properties of these ion-rich ices can be of fundamental importance for objects as diverse as comets, planets, and molecular clouds and may account for several poorly understood phenomena associated with each of these object classes.

  9. Abundances in the Planetary Nebula IC 5217

    NASA Technical Reports Server (NTRS)

    Hyung, Siek; Aller, Lawrence H.; Feibelman, Walter A.; Lee, Woo-Baik; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    High resolution optical wavelength spectroscopic data were secured in the optical wavelengths, 3700A - 10,050A, for the planetary nebula IC 5217 with the Hamilton Echelle Spectrograph at Lick Observatory. These optical spectra have been analyzed along with the near-UV and UV archive data. Diagnostic analyses indicate a nebular physical condition with electron temperature of about 10,700 K (from the [O III] lines) and the density of N(sub epsilon) = 5000/cm. Ionic concentrations have been derived with the representative diagnostics, and with the aid of a photoionization model construction, we derived the elemental abundances. Contrary to the previous studies found in the literature, He and C appear to be depleted compared to the average planetary nebula and to the Sun (and S marginally so), while the remaining elements appear to be close to the average value. IC 5217 may have evolved from an O-rich progenitor and the central star temperature of IC 5217 is likely to be 92,000 K.

  10. Abundances of isotopes in planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Owen, T.

    1978-01-01

    Carbon and oxygen isotopes show no large anomalies on Venus (no more than 10-15%) or Mars (less than 5%); the high value of N-15/N-14 found on Mars is explained by nonthermal escape of nitrogen. The isotopes of nonradiogenic noble gases in the atmosphere of Mars exhibit abundance patterns similar to those in the primordial component of meteoritic gases and in the earth's atmosphere. This implies that gas fractionation took place in the inner solar nebula prior to planet formation. The relatively high value of Xe-129 on Mars emphasizes its deficiency on earth, implying a difference in accretion histories of volatiles for the two planets. In the outer solar system, normal isotope ratios for nitrogen and carbon on Jupiter, and for carbon on Saturn are found, but precision is low (+ or - 15% at best). Controversy exists about the correct value of D/H, with current estimates ranging from 2.3 plus or minus 1.1 to 5.1 plus or - 0.7 times 10 to the minus 5th. Planetary missions planned for the next few years should add considerably to the quantity and quality of these data.

  11. Energetic particle abundances in solar electron events

    NASA Technical Reports Server (NTRS)

    Reames, D. V.; Cane, H. V.; Von Rosenvinge, T. T.

    1990-01-01

    The results of a comprehensive search of the ISEE 3 energetic particle data for solar electron events with associated increases in elements with atomic number Z = 6 or greater are reported. A sample of 90 such events was obtained. The events support earlier evidence of a bimodal distribution in Fe/O or, more clearly, in Fe/C. Most of the electron events belong to the group that is Fe-rich in comparison with the coronal abundance. The Fe-rich events are frequently also He-3-rich and are associated with type III and type V radio bursts and impulsive solar flares. Fe-poor events are associated with type IV bursts and with interplanetary shocks. With some exceptions, event-to-event enhancements in the heavier elements vary smoothly with Z and with Fe/C. In fact, these variations extend across the full range of events despite inferred differences in acceleration mechanism. The origin of source material in all events appears to be coronal and not photospheric.

  12. Modeling abundances in star forming galaxies

    NASA Astrophysics Data System (ADS)

    Kobayashi, Chiaki

    2015-08-01

    Heavy elements are produced from various types of supernovae (and AGB stars). I first show that elemental abundances of extremely metal-poor stars are consistent not with pair-instability supernovae but with faint supernovae. Then I introduce subclasses of Type Ia supernovae such as SN 2002cx-like objects and sub-Chandrasekhar mass explosions. These "minor" supernovae are important in the early Universe or metal-poor systems such as dwarf spheroidal galaxies. With "major" chemical enrichment sources, I show cosmic chemical enrichment in our cosmological, hydrodynamical simulations. The feedback from active galactic nuclei (AGN) is also included with a new model for the formation of black holes motivated by the first star formation. AGN-driven outflows transport metals into the circumgalactic medium and the intergalactic medium. Nonetheless, the metallicity changes of galaxies are negligible, and the mass-metallicity relations, which are mainly generated by supernova feedback at the first star burst, are preserved. Within galaxies, metallicity radial gradients are produced, which can be affected by AGN feedback but are more sensitive to the merging histories. We find a weak correlation between the gradients and galaxy mass, which is consistent with available observations. These simulations also provide predictions of supernova/hypernova/GRB rates and the properties of their host galaxies.

  13. Late Embryogenesis Abundant (LEA) proteins in legumes

    PubMed Central

    Battaglia, Marina; Covarrubias, Alejandra A.

    2013-01-01

    Plants are exposed to different external conditions that affect growth, development, and productivity. Water deficit is one of these adverse conditions caused by drought, salinity, and extreme temperatures. Plants have developed different responses to prevent, ameliorate or repair the damage inflicted by these stressful environments. One of these responses is the activation of a set of genes encoding a group of hydrophilic proteins that typically accumulate to high levels during seed dehydration, at the last stage of embryogenesis, hence named Late Embryogenesis Abundant (LEA) proteins. LEA proteins also accumulate in response to water limitation in vegetative tissues, and have been classified in seven groups based on their amino acid sequence similarity and on the presence of distinctive conserved motifs. These proteins are widely distributed in the plant kingdom, from ferns to angiosperms, suggesting a relevant role in the plant response to this unfavorable environmental condition. In this review, we analyzed the LEA proteins from those legumes whose complete genomes have been sequenced such as Phaseolus vulgaris, Glycine max, Medicago truncatula, Lotus japonicus, Cajanus cajan, and Cicer arietinum. Considering their distinctive motifs, LEA proteins from the different groups were identified, and their sequence analysis allowed the recognition of novel legume specific motifs. Moreover, we compile their transcript accumulation patterns based on publicly available data. In spite of the limited information on these proteins in legumes, the analysis and data compiled here confirm the high correlation between their accumulation and water deficit, reinforcing their functional relevance under this detrimental conditions. PMID:23805145

  14. Numerical resolution limits on subhalo abundance matching

    NASA Astrophysics Data System (ADS)

    Guo, Qi; White, Simon

    2014-02-01

    Subhalo abundance matching (SHAM) inserts galaxies into dark matter only simulations of the growth of cosmic structure in a way that requires minimal assumptions about galaxy formation. A galaxy is placed at the potential minimum of each distinct self-bound subhalo with a luminosity which is a monotonically increasing function of the maximum mass (or circular velocity) attained over the subhalo's earlier history. Galaxy and subhalo properties are linked by matching model and observed luminosity functions. Simulated structures can then be compared in detail with observation, for example, through galaxy correlation statistics, group catalogues or galaxy-galaxy lensing. Robust astrophysical conclusions can be drawn from such a comparison only on scales which are unaffected by the numerical limitations of the simulation. Here, we compare results for the Millennium Simulation (MS) with subhaloes defined using the SUBFIND to those obtained applying identical analysis to the much higher resolution Millennium-II. Correlation statistics on scales between 200 and 2 Mpc converge to within 20 per cent only for subhaloes with masses at infall corresponding to at least 1000 simulation particles in the MS. Numerically converged results can be obtained to much lower infall particle number, if galaxies are followed even after their associated subhaloes have been tidally disrupted, as in most recent semi-analytic galaxy formation simulations. This allows robust comparison between simulation and observation over a wider dynamic range in mass than for a SHAM analysis which ignores such `orphan' galaxies.

  15. Late Embryogenesis Abundant (LEA) proteins in legumes.

    PubMed

    Battaglia, Marina; Covarrubias, Alejandra A

    2013-01-01

    Plants are exposed to different external conditions that affect growth, development, and productivity. Water deficit is one of these adverse conditions caused by drought, salinity, and extreme temperatures. Plants have developed different responses to prevent, ameliorate or repair the damage inflicted by these stressful environments. One of these responses is the activation of a set of genes encoding a group of hydrophilic proteins that typically accumulate to high levels during seed dehydration, at the last stage of embryogenesis, hence named Late Embryogenesis Abundant (LEA) proteins. LEA proteins also accumulate in response to water limitation in vegetative tissues, and have been classified in seven groups based on their amino acid sequence similarity and on the presence of distinctive conserved motifs. These proteins are widely distributed in the plant kingdom, from ferns to angiosperms, suggesting a relevant role in the plant response to this unfavorable environmental condition. In this review, we analyzed the LEA proteins from those legumes whose complete genomes have been sequenced such as Phaseolus vulgaris, Glycine max, Medicago truncatula, Lotus japonicus, Cajanus cajan, and Cicer arietinum. Considering their distinctive motifs, LEA proteins from the different groups were identified, and their sequence analysis allowed the recognition of novel legume specific motifs. Moreover, we compile their transcript accumulation patterns based on publicly available data. In spite of the limited information on these proteins in legumes, the analysis and data compiled here confirm the high correlation between their accumulation and water deficit, reinforcing their functional relevance under this detrimental conditions. PMID:23805145

  16. Beryllium abundances in Hg-Mn stars

    SciTech Connect

    Boesgaard, A.M.; Heacox, W.D.; Wolff, S.C.; Borsenberger, J.; Praderie, F.

    1982-08-15

    The Hg-Mn stars show anomalous line strengths of many chemical elements including Be. We have observed the Be ii resonance doublet at lambdalambda 3130, 3131 at 6.7 A mm/sup -1/ in 43 Hg-Mn stars and 10 normal stars in the same temperature range with the coude spectrograph of the 2.24 m University of Hawaii telescope at Mauna Kea. Measured equivalent widths of the two lines and/or the blend of the doublet have been compared with predictions from (1) LTE model atmospheres and (2) non-LTE line formation on non-LTE model atmospheres. (For strong Be ii lines, the LTE calculations result in more Be by factors of 2 to 4 than do the non-LTE calculations.) Overabundances of factors of 20--2 x 10/sup 4/ relative to solar have been found for 75% of the Hg-Mn stars. The 25% with little or no Be are typically among the cooler Hg-Mn stars, but for the stars with Be excesses, there is only marginal evidence for a correlationi of the size of the overabundance and temperature. It is suggested that diffusion driven by radiation pressure is responsible for the observed Be abundance anomalies.

  17. Elemental Abundance Analyses with DAO Spectrograms. XXXV. On the Iron Abundances of B and A Stars

    NASA Astrophysics Data System (ADS)

    Adelman, Saul J.

    2014-06-01

    I compared the results of LTE fine analyses for B and A stars based on the newer "precise and accurate" Fe II gf values of Melendez & Barbuy (MB) with those based on the relatively recent major critical compilation of Fuhr & Wiese (FW). Only nonblended Fe II lines with both FW and MB gf values for 34 B and A stars with equivalent widths derived from high dispersion, high (>200) signal-to-noise ratio Dominion Astrophysical Observatory spectra were used. For most stars the standard deviations of the abundances derived from Fe II lines decrease slightly with the MB values, which is the signature of better consistency among the gf values. Then, for stars with many Fe I lines, I performed analyses using all lines with FW gf values and those with only A and B quality gf values and found minor improvements in the latter case. However, the abundances and microturbulences derived from Fe I lines are in better agreement with the Fe II FW results. The discrepancy between the results for Fe I FW and Fe II MB values could be due to NLTE effects on Fe I. A more limited comparison is made with the recent theoretical values of Deb & Hibbert which, when used, show a greater scatter of the derived Fe II gf values and smaller abundances than those obtained with the MB gf values.

  18. Chemical abundance analysis of symbiotic giants - III. Metallicity and CNO abundance patterns in 24 southern systems

    NASA Astrophysics Data System (ADS)

    Gałan, Cezary; Mikołajewska, Joanna; Hinkle, Kenneth H.; Joyce, Richard R.

    2016-01-01

    The elemental abundances of symbiotic giants are essential to address the role of chemical composition in the evolution of symbiotic binaries, to map their parent population, and to trace their mass transfer history. However, the number of symbiotic giants with fairly well determined photospheric composition is still insufficient for statistical analyses. This is the third in a series of papers on the chemical composition of symbiotic giants determined from high-resolution (R ˜ 50 000), near-infrared spectra. Here we present results for 24 S-type systems. Spectrum synthesis methods employing standard local thermal equilibrium analysis and atmosphere models were used to obtain photospheric abundances of CNO and elements around the iron peak (Fe, Ti, Ni, and Sc). Our analysis reveals metallicities distributed in a wide range from slightly supersolar ([Fe/H] ˜ +0.35 dex) to significantly subsolar ([Fe/H] ˜ -0.8 dex) but principally with near-solar and slightly subsolar metallicity ([Fe/H] ˜ -0.4 to -0.3 dex). The enrichment in 14N isotope, found in all these objects, indicates that the giants have experienced the first dredge-up. This was confirmed in a number of objects by the low 12C/13C ratio (5-23). We found that the relative abundance of [Ti/Fe] is generally large in red symbiotic systems.

  19. Abundance models improve spatial and temporal prioritization of conservation resources.

    PubMed

    Johnston, Alison; Fink, Daniel; Reynolds, Mark D; Hochachka, Wesley M; Sullivan, Brian L; Bruns, Nicholas E; Hallstein, Eric; Merrifield, Matt S; Matsumoto, Sandi; Kelling, Steve

    2015-10-01

    Conservation prioritization requires knowledge about organism distribution and density. This information is often inferred from models that estimate the probability of species occurrence rather than from models that estimate species abundance, because abundance data are harder to obtain and model. However, occurrence and abundance may not display similar patterns and therefore development of robust, scalable, abundance models is critical to ensuring that scarce conservation resources are applied where they can have the greatest benefits. Motivated by a dynamic land conservation program, we develop and assess a general method for modeling relative abundance using citizen science monitoring data. Weekly estimates of relative abundance and occurrence were compared for prioritizing times and locations of conservation actions for migratory waterbird species in California, USA. We found that abundance estimates consistently provided better rankings of observed counts than occurrence estimates. Additionally, the relationship between abundance and occurrence was nonlinear and varied by species and season. Across species, locations prioritized by occurrence models had only 10-58% overlap with locations prioritized by abundance models, highlighting that occurrence models will not typically identify the locations of highest abundance that are vital for conservation of populations. PMID:26591443

  20. The Origin of Element Abundance Variations in Solar Energetic Particles

    NASA Astrophysics Data System (ADS)

    Reames, Donald V.

    2016-08-01

    Abundance enhancements, during acceleration and transport in both gradual and impulsive solar energetic particle (SEP) events, vary approximately as power laws in the mass-to-charge ratio [A/Q] of the ions. Since the Q-values depend upon the electron temperature of the source plasma, this has allowed a determination of this temperature from the pattern of element-abundance enhancements and a verification of the expected inverse-time dependence of the power of A/Q for diffusive transport of ions from the SEP events, with scattering mean free paths found to be between 0.2 and 1 AU. SEP events derived from plasma of different temperatures map into different regions in typical cross-plots of abundances, spreading the distributions. In comparisons of SEP events with temperatures above 2 MK, impulsive events show much broader non-thermal variation of abundances than do gradual events. The extensive shock waves accelerating ions in gradual events may average over much of an active region where numerous but smaller magnetic reconnections, "nanojets", produce suprathermal seed ions, thus averaging over varying abundances, while an impulsive SEP event only samples one local region of abundance variations. Evidence for a reference He/O-abundance ratio of 91, rather than 57, is also found for the hotter plasma. However, while this is similar to the solar-wind abundance of He/O, the solar-wind abundances otherwise provide an unacceptably poor reference for the SEP-abundance enhancements, generating extremely large errors.

  1. The Origin of Element Abundance Variations in Solar Energetic Particles

    NASA Astrophysics Data System (ADS)

    Reames, Donald V.

    2016-07-01

    Abundance enhancements, during acceleration and transport in both gradual and impulsive solar energetic particle (SEP) events, vary approximately as power laws in the mass-to-charge ratio [ A/Q] of the ions. Since the Q-values depend upon the electron temperature of the source plasma, this has allowed a determination of this temperature from the pattern of element-abundance enhancements and a verification of the expected inverse-time dependence of the power of A/Q for diffusive transport of ions from the SEP events, with scattering mean free paths found to be between 0.2 and 1 AU. SEP events derived from plasma of different temperatures map into different regions in typical cross-plots of abundances, spreading the distributions. In comparisons of SEP events with temperatures above 2 MK, impulsive events show much broader non-thermal variation of abundances than do gradual events. The extensive shock waves accelerating ions in gradual events may average over much of an active region where numerous but smaller magnetic reconnections, "nanojets", produce suprathermal seed ions, thus averaging over varying abundances, while an impulsive SEP event only samples one local region of abundance variations. Evidence for a reference He/O-abundance ratio of 91, rather than 57, is also found for the hotter plasma. However, while this is similar to the solar-wind abundance of He/O, the solar-wind abundances otherwise provide an unacceptably poor reference for the SEP-abundance enhancements, generating extremely large errors.

  2. An Increased Abundance of Tumor-Infiltrating Regulatory T Cells Is Correlated with the Progression and Prognosis of Pancreatic Ductal Adenocarcinoma

    PubMed Central

    Tang, Yichen; Xu, Xuejun; Guo, Shixiang; Zhang, Chaobin; Tang, Yan; Tian, Yi; Ni, Bing; Lu, Binfeng; Wang, Huaizhi

    2014-01-01

    CD4+CD25+Foxp3+ regulatory T cells (Tregs) can inhibit cytotoxic responses. Though several studies have analyzed Treg frequency in the peripheral blood mononuclear cells (PBMCs) of pancreatic ductal adenocarcinoma (PDA) patients using flow cytometry (FCM), few studies have examined how intratumoral Tregs might contribute to immunosuppression in the tumor microenvironment. Thus, the potential role of intratumoral Tregs in PDA patients remains to be elucidated. In this study, we found that the percentages of Tregs, CD4+ T cells and CD8+ T cells were all increased significantly in tumor tissue compared to control pancreatic tissue, as assessed via FCM, whereas the percentages of these cell types in PBMCs did not differ between PDA patients and healthy volunteers. The percentages of CD8+ T cells in tumors were significantly lower than in PDA patient PBMCs. In addition, the relative numbers of CD4+CD25+Foxp3+ Tregs and CD8+ T cells were negatively correlated in the tissue of PDA patients, and the abundance of Tregs was significantly correlated with tumor differentiation. Additionally, Foxp3+ T cells were observed more frequently in juxtatumoral stroma (immediately adjacent to the tumor epithelial cells). Patients showing an increased prevalence of Foxp3+ T cells had a poorer prognosis, which was an independent factor for patient survival. These results suggest that Tregs may promote PDA progression by inhibiting the antitumor immunity of CD8+ T cells at local intratumoral sites. Moreover, a high proportion of Tregs in tumor tissues may reflect suppressed antitumor immunity. PMID:24637664

  3. Abundances, planetary nebulae, and stellar evolution

    NASA Technical Reports Server (NTRS)

    Aller, Lawrence H.

    1994-01-01

    Among Henry Norris Russell's many achievements were his contributions to solar and stellar spectroscopy, in particular, to an analysis of the chemical composition of the solar atmosphere. The question of composition differences between stars was hotly debated; some distinguished astronomers argued that all stars had the solar composition. Some early challenges to this doctrine are described. Determinations of chemical compositions of gaseous nebulae were much more difficult. If we observe the lines of a given chemical element in one ionization stage in a stellar spectrum, we can deduce readily the abundance of that element. No such luxury is available for a planetary or diffuse gaseous nebula. We must measure lines of as many ionization stages as we can. Furthermore, a nebula is an extended object. Often detailed spectroscopy is at hand only for narrow pencil columns taken through the image. Different observers use a variety of apertures. Fortunately it is possible to calculate theoretical spectra for any arbitrary cross section taken through a symmetrical model, so UV, optical, and IR observations all can be compared properly with a prediction. The value of high-resolution spectra obtained with instruments such as the Hamilton Echelle Spectrograph at Lick Observatory is emphasized. Improved fluxes for weak but important transitions are found. Close blends of lines of different ions can be resolved, and checks can be made on predictions of atomic parameters such as Einstein A-values and collision strengths. High spectral resolution data have been obtained and reduced for 22 planetary nebulae of varying size, structure, stellar population membership, dustiness, level of excitation, evolutionary status, and chemical compositions. The promise seems justified that with such extensive, high quality data, additional insights on nebular genesis and late states of stellar evolution can be found. The present survey is confined to nebulae of high surface brightness, but

  4. Nitrogen abundances in damped Lyalpha absorbers

    NASA Astrophysics Data System (ADS)

    Zafar, T.; Centurión, M.; Molaro, P.; Péroux, C.; D'Odorico, V.; Vladilo, G.

    Nitrogen is thought to have both primary and secondary origins depending on whether the seed carbon and oxygen are produced by the star itself (primary) or already present in the interstellar medium (secondary) from which star forms. Damped Lyalpha (DLA) and sub-DLA systems with typical metallicities of -3.0≲ Z/Z⊙ ≲ -0.5 are excellent tools to study nitrogen production. We made a search for nitrogen in the European Southern Observatory (ESO) Ultraviolet Visual Echelle Spectrograph (UVES) advanced data products (EUADP) database. In the EUADP database, we find 10 new measurements and 9 upper limits of nitrogen. We further compiled DLA/sub-DLA data from the literature with estimates available of nitrogen and alpha -elements. This yields a total of 98 systems, i.e. the largest nitrogen abundance sample investigated so far. In agreement with previous studies, we indeed find a bimodal [N/alpha ] behaviour: three-quarter systems show a mean value of [N/alpha ] =-0.87 with a scatter of 0.21 dex and one-quarter shows ratios clustered at [N/alpha ] = -1.43 with a lower dispersion of 0.13 dex. The high [N/alpha ] group is consistent with the blue compact dwarves and dwarf irregular galaxies, suggesting primary nitrogen production. The low [N/alpha ] group is the lowest ever observed in any astrophysical site and probably provides an evidence of the primary production by fast rotating massive stars in young sites. Moreover, we find a transition between the two [N/alpha ] groups around [N/H] ≃-2.5. The transition is not abrupt and there are a few systems lying in the transition region. Additional observations of DLAs/sub-DLAs below [N/H] <-2.5 would provide more clues.

  5. Testing spherical evolution for modelling void abundances

    NASA Astrophysics Data System (ADS)

    Achitouv, Ixandra; Neyrinck, Mark; Paranjape, Aseem

    2015-08-01

    We compare analytical predictions of void volume functions to those measured from N-body simulations, detecting voids with the ZOBOV void finder. We push to very small, non-linear voids, below few Mpc radius, by considering the unsampled dark matter density field. We also study the case where voids are identified using haloes. We develop analytical formula for the void abundance of both the excursion set approach and the peaks formalism. These formulas are valid for random walks smoothed with a top-hat filter in real space, with a large class of realistic barrier models. We test the extent to which the spherical evolution approximation, which forms the basis of the analytical predictions, models the highly aspherical voids that occur in the cosmic web, and are found by a watershed-based algorithm such as ZOBOV. We show that the volume function returned by ZOBOV is quite sensitive to the choice of treatment of subvoids, a fact that has not been appreciated previously. For reasonable choices of subvoid exclusion, we find that the Lagrangian density δv of the ZOBOV voids - which is predicted to be a constant δv ≈ -2.7 in the spherical evolution model - is different from the predicted value, showing substantial scatter and scale dependence. This result applies to voids identified at z = 0 with effective radius between 1 and 10 h-1 Mpc. Our analytical approximations are flexible enough to give a good description of the resulting volume function; however, this happens for choices of parameter values that are different from those suggested by the spherical evolution assumption. We conclude that analytical models for voids must move away from the spherical approximation in order to be applied successfully to observations, and we discuss some possible ways forward.

  6. Comparing halo bias from abundance and clustering

    NASA Astrophysics Data System (ADS)

    Hoffmann, K.; Bel, J.; Gaztañaga, E.

    2015-06-01

    We model the abundance of haloes in the ˜(3 Gpc h-1)3 volume of the MICE Grand Challenge simulation by fitting the universal mass function with an improved Jackknife error covariance estimator that matches theory predictions. We present unifying relations between different fitting models and new predictions for linear (b1) and non-linear (c2 and c3) halo clustering bias. Different mass function fits show strong variations in their performance when including the low mass range (Mh ≲ 3 × 1012 M⊙ h-1) in the analysis. Together with fits from the literature, we find an overall variation in the amplitudes of around 10 per cent in the low mass and up to 50 per cent in the high mass (galaxy cluster) range (Mh > 1014 M⊙ h-1). These variations propagate into a 10 per cent change in b1 predictions and a 50 per cent change in c2 or c3. Despite these strong variations, we find universal relations between b1 and c2 or c3 for which we provide simple fits. Excluding low-mass haloes, different models fitted with reasonable goodness in this analysis, show per cent level agreement in their b1 predictions, but are systematically 5-10 per cent lower than the bias directly measured with two-point halo-mass clustering. This result confirms previous findings derived from smaller volumes (and smaller masses). Inaccuracies in the bias predictions lead to 5-10 per cent errors in growth measurements. They also affect any halo occupation distribution fitting or (cluster) mass calibration from clustering measurements.

  7. Abundances, planetary nebulae, and stellar evolution

    NASA Astrophysics Data System (ADS)

    Aller, Lawrence H.

    1994-09-01

    Among Henry Norris Russell's many achievements were his contributions to solar and stellar spectroscopy, in particular, to an analysis of the chemical composition of the solar atmosphere. The question of composition differences between stars was hotly debated; some distinguished astronomers argued that all stars had the solar composition. Some early challenges to this doctrine are described. Determinations of chemical compositions of gaseous nebulae were much more difficult. If we observe the lines of a given chemical element in one ionization stage in a stellar spectrum, we can deduce readily the abundance of that element. No such luxury is available for a planetary or diffuse gaseous nebula. We must measure lines of as many ionization stages as we can. Furthermore, a nebula is an extended object. Often detailed spectroscopy is at hand only for narrow pencil columns taken through the image. Different observers use a variety of apertures. Fortunately it is possible to calculate theoretical spectra for any arbitrary cross section taken through a symmetrical model, so UV, optical, and IR observations all can be compared properly with a prediction. The value of high-resolution spectra obtained with instruments such as the Hamilton Echelle Spectrograph at Lick Observatory is emphasized. Improved fluxes for weak but important transitions are found. Close blends of lines of different ions can be resolved, and checks can be made on predictions of atomic parameters such as Einstein A-values and collision strengths. High spectral resolution data have been obtained and reduced for 22 planetary nebulae of varying size, structure, stellar population membership, dustiness, level of excitation, evolutionary status, and chemical compositions. The promise seems justified that with such extensive, high quality data, additional insights on nebular genesis and late states of stellar evolution can be found. The present survey is confined to nebulae of high surface brightness, but

  8. Global distribution of microbial abundance and biomass in subseafloor sediment

    PubMed Central

    Kallmeyer, Jens; Pockalny, Robert; Adhikari, Rishi Ram; Smith, David C.; D’Hondt, Steven

    2012-01-01

    The global geographic distribution of subseafloor sedimentary microbes and the cause(s) of that distribution are largely unexplored. Here, we show that total microbial cell abundance in subseafloor sediment varies between sites by ca. five orders of magnitude. This variation is strongly correlated with mean sedimentation rate and distance from land. Based on these correlations, we estimate global subseafloor sedimentary microbial abundance to be 2.9⋅1029 cells [corresponding to 4.1 petagram (Pg) C and ∼0.6% of Earth’s total living biomass]. This estimate of subseafloor sedimentary microbial abundance is roughly equal to previous estimates of total microbial abundance in seawater and total microbial abundance in soil. It is much lower than previous estimates of subseafloor sedimentary microbial abundance. In consequence, we estimate Earth’s total number of microbes and total living biomass to be, respectively, 50–78% and 10–45% lower than previous estimates. PMID:22927371

  9. On the radial abundance gradients in discs of irregular galaxies

    NASA Astrophysics Data System (ADS)

    Pilyugin, L. S.; Grebel, E. K.; Zinchenko, I. A.

    2015-07-01

    We determine the radial abundance distributions across the discs of 14 irregular galaxies of the types Sm and Im (morphological T types 9 and 10) as traced by their H II regions. The oxygen and nitrogen abundances in H II regions are estimated through the Te method or/and with the counterpart method (C method). Moreover, we examine the correspondence between the radial abundance gradient and the surface brightness profile. We find that irregular galaxies with a flat inner profile (flat or outwardly increasing surface brightness in the central region) show shallow (if any) radial abundance gradients. On the other hand, irregular galaxies with a steep inner profile (with or without a bulge or central star cluster) usually show rather steep radial abundance gradients. This is in contrast to the widely held belief that irregular galaxies do not usually show a radial abundance gradient.

  10. Solar abundances as derived from solar energetic particles

    NASA Technical Reports Server (NTRS)

    Stone, E. C.

    1989-01-01

    Recent studies have shown that there are well defined average abundances of heavy (Z above 2) solar energetic particles (SEPs), with variations in the acceleration and propagation producing a systematic flare-to-flare fractionation that depends on the charge per unit mass of the ion. Correcting the average SEP abundances for this fractionation yields SEP-derived coronal abundances for 20 elements. High-resolution SEP studies have also provided isotopic abundances for five elements. SEP-derived abundances indicate that elements with high first ionization potentials (greater than 10 eV) are depleted in the corona relative to the photosphere and provide new information on the solar abundance of C and Ne-22.

  11. Abiotic mediation of a mutualism drives herbivore abundance.

    PubMed

    Mooney, Emily H; Phillips, Joseph S; Tillberg, Chadwick V; Sandrow, Cheryl; Nelson, Annika S; Mooney, Kailen A

    2016-01-01

    Species abundance is typically determined by the abiotic environment, but the extent to which such effects occur through the mediation of biotic interactions, including mutualisms, is unknown. We explored how light environment (open meadow vs. shaded understory) mediates the abundance and ant tending of the aphid Aphis helianthi feeding on the herb Ligusticum porteri. Yearly surveys consistently found aphids to be more than 17-fold more abundant on open meadow plants than on shaded understory plants. Manipulations demonstrated that this abundance pattern was not due to the direct effects of light environment on aphid performance, or indirectly through host plant quality or the effects of predators. Instead, open meadows had higher ant abundance and per capita rates of aphid tending and, accordingly, ants increased aphid population growth in meadow but not understory environments. The abiotic environment thus drives the abundance of this herbivore exclusively through the mediation of a protection mutualism. PMID:26563752

  12. Evolution of dispersion in the cosmic deuterium abundance

    NASA Astrophysics Data System (ADS)

    Dvorkin, Irina; Vangioni, Elisabeth; Silk, Joseph; Petitjean, Patrick; Olive, Keith A.

    2016-05-01

    Deuterium is created during big bang nucleosynthesis, and, in contrast to the other light stable nuclei, can only be destroyed thereafter by fusion in stellar interiors. In this Letter, we study the cosmic evolution of the deuterium abundance in the interstellar medium (ISM) and its dispersion using realistic galaxy evolution models. We find that models that reproduce the observed metal abundance are compatible with observations of the deuterium abundance in the local ISM and z ˜ 3 absorption line systems. In particular, we reproduce the low astration factor which we attribute to a low global star formation efficiency. We calculate the dispersion in deuterium abundance arising from different structure formation histories in different parts of the Universe. Our model also predicts a tight correlation between deuterium and metal abundances which could be used to measure the primordial deuterium abundance.

  13. Galilean satellite eclipse studies. III - Jovian methane abundance

    NASA Technical Reports Server (NTRS)

    Smith, D. W.; Greene, T. F.

    1980-01-01

    The methane abundance in the lower Jovian stratosphere is measured using the Galilean satellite eclipse technique. The average mixing ratio at the locations measured is larger than the expected value for a solar abundance of carbon with the expected value for a solar abundance of carbon with the possibility of some zenographic variation. Observationally compatible values are found for the South Temperate Zone, the edge of the Great Red Spot and the South Tropical Zone, and the Great Red Spot.

  14. The abundance of carbon in HU 2-1

    NASA Technical Reports Server (NTRS)

    Lutz, J. H.

    1981-01-01

    A logarithmic carbon abundance of 8.61 + or - 0.3 is derived for the planetary nebula Hu 2-1 using data taken with the International Ultraviolet Explorer satellite. This value is close to the logarithmic carbon abundance of 8.67 + or - 0.1, found for the sun by other investigators. The carbon abundance of Hu 2-1 is compared to those of other planetary nebulae and to the predictions of stellar evolution calculations.

  15. Column abundance measurements of atmospheric hydroxyl at 45 deg S

    NASA Technical Reports Server (NTRS)

    Wood, S. W.; Keep, D. J.; Burnett, C. R.; Burnett, E. B.

    1994-01-01

    The first Southern Hemisphere measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been obtained at Lauder, New Zealand (45 deg S) with a PEPSIOS instrument measuring the absorption of sunlight at 308 nm. The variation of column OH with solar zenith angle is similar to that measured at other sites. However average annual abundances of OH are about 20% higher than those found by similar measurements at 40 deg N. Minimum OH abundances about 10% less than average levels at 40 deg N, are observed during austral spring. The OH abundance abruptly increases by 30% in early summer and remains at the elevated level until late the following winter.

  16. Abundances of planetary nebulae in the Galactic bulge

    NASA Astrophysics Data System (ADS)

    Pottasch, S. R.; Bernard-Salas, J.

    2015-11-01

    Context. Planetary nebulae (PNe) abundances are poorly known for those nebulae in the Galactic bulge. This is because of the high and uneven extinction in the bulge which makes visual spectral measurements difficult. In addition, the extinction corrections may be unreliable. Elements considered are O, N, Ne, S, Ar, and Cl. Aims: We determine the abundances in 19 PNe, 18 of which are located in the bulge. This doubles the number of PNe abundance determinations in the bulge. The Galactic abundance gradient is discussed for five elements. Methods: The mid-infrared spectra measured by the Spitzer Space Telescope are used to determine the abundances. This part of the spectrum is little affected by extinction for which an uncertain correction is no longer necessary. In addition the connection with the visible and ultraviolet spectrum becomes simpler because hydrogen lines are observed both in the infrared and in the visible spectra. In this way we more than double the number of PNe with reliable abundances. Results: Reliable abundances are obtained for O, N, Ne, S, and Ar for Galactic bulge PNe. Conclusions: The Galactic abundance gradient is less steep than previously thought. This is especially true for oxygen. The sulfur abundance is reliable because all stages of ionization expected have been measured. It is not systematically low compared to oxygen as has been found for some Galactic PNe. Based on observations with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology.

  17. Modelling occurrence and abundance of species when detection is imperfect

    USGS Publications Warehouse

    Royle, J. Andrew; Nichols, J.D.; Kery, M.

    2005-01-01

    Relationships between species abundance and occupancy are of considerable interest in metapopulation biology and in macroecology. Such relationships may be described concisely using probability models that characterize variation in abundance of a species. However, estimation of the parameters of these models in most ecological problems is impaired by imperfect detection. When organisms are detected imperfectly, observed counts are biased estimates of true abundance, and this induces bias in stated occupancy or occurrence probability. In this paper we consider a class of models that enable estimation of abundance/occupancy relationships from counts of organisms that result from surveys in which detection is imperfect. Under such models, parameter estimation and inference are based on conventional likelihood methods. We provide an application of these models to geographically extensive breeding bird survey data in which alternative models of abundance are considered that include factors that influence variation in abundance and detectability. Using these models, we produce estimates of abundance and occupancy maps that honor important sources of spatial variation in avian abundance and provide clearly interpretable characterizations of abundance and occupancy adjusted for imperfect detection.

  18. Origin of Stellar Abundances in the early Galaxy

    SciTech Connect

    Montes, F.; Beers, T. C.; Cowan, J.; Elliot, T.; Schatz, H.; Farouqi, K.; Gallino, R.; Heil, M.; Kratz, K.-L.; Pfeiffer, B.; Pignatari, M.

    2007-10-26

    Observations of metal-poor stars in the last decade have revealed an abundance pattern that have recently been explained as the result of two nucleosynthesis processes, a strong r-process that creates most of the Z{>=}56 and some 38{<=}Z{<=}47 abundances and a light element primary process (LEPP) responsible for creating the remaining 38{<=}Z{<=}47 abundances and some small contribution to heavier elements. We review some of the current literature on the LEPP and show a derived abundance pattern as a function of mass number.

  19. Gaseous abundances in galaxies explored with IFU surveys

    NASA Astrophysics Data System (ADS)

    Sánchez, S. F.; Sánchez-Menguiano, L.; Califa Collaboration

    2016-06-01

    We present here our recent results in the analysis of the gas abundance gradients in galaxies in the Local Universe using IFU data extracted mostly from the CALIFA survey. With an updated statistics based on the analysis of more than 600 galaxies we confirm previous results: (1) the abundance gradient seems to present a characteristic value when normalized to the effective radius, (2) the shape of the abundance gradient depends on the stellar mass, with a clear drop in the inner regions for more massive galaxies, (3) using the abundance at the effective radius we confirm our previous results showing no secondary correlation with the SFR in the M-z relation.

  20. Highly Siderophile Element Abundances in Martian Meteorites

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Neal, C. R.; Ely, J. C.

    2001-01-01

    Critical evaluation of new and literature data for highly siderophile elements (HSE) in Martian (SNC) meteorites allows several first order conclusions to be drawn. (i) Re concentrations in SNC meteorites are nearly constant (within a factor of two) and do not correlate with rock type. Exceptions to this rule are Chassigny and Dar al Gani (DaG) 476, both of which are inferred to have experienced terrestrial Re contamination. (ii) Fractionations between Rh and Pd are small. Excluding Shergotty, the Rh/Pd ratio of the SNC suite is 0.22\\pm0.05. (iii) Os and Ir contents vary by about four orders of magnitude; and positive correlations with MgO, Cr, and Ni suggest that these variations are not controlled by sulfide fractionation. A possible exception is the orthopyroxenite ALH84001, whose HSE's (including Ni, which is compatible in opx) are very low. (iv) Zagami, Shergotty, and Nakhla have nearly identical HSE signatures. Shergotty and Zagami have experienced assimilation-fractional crystallization (AFC) and have "crustal" Sr and Nd isotopic signatures. Conversely, the Nakhla parent was a small degree partial melt of a depleted mantle that interacted little with the Martian crust. These observations suggest that "evolved" HSE signatures can be produced by either fractional crystallization or small degrees of partial melting. (v) Chassigny and other mafic SNC's have HSE signatures that are very distinct from those of Nakhla-Zagami-Shergotty. The HSE elemental ratios of mafic SNC's approach chondritic, implying that the Martian mantle has nearly chondritic relative abundances of the HSE's. (vi) This chondritic HSE signature is observed in SNC's of various ages, suggesting that this is an ancient feature that has not evolved over time. (vii) No correlation is observed between HSE's and signatures of crustal contamination (e.g., Sr isotopes), indicating that the HSE signatures of the SNC suite are not derived from the crust. (vii) The Ru/Pd for the SNC suite ratio is about

  1. Heavy Element Abundances in NGC 5846

    NASA Technical Reports Server (NTRS)

    Jones, Christine

    2000-01-01

    In this paper we analyze the diffuse X-ray coronae surrounding the elliptical galaxy NGC 5846, combining measurements from two observatories, ROSAT and the Advanced Satellite for Cosmology and Astrophysics. We map the gas temperature distribution and find a central cool region within an approximately isothermal gas halo extending to a radius of about 50 kpc and evidence for a temperature decrease at larger radii. With a radially falling temperature profile, the total mass converges to (9.6 +/- 1.0) x 10(exp 12) solar mass at 230 kpc radius. This corresponds to a total mass to blue light ratio of 53 +/- 5 solar mass/solar luminosity. As in other early type galaxies, the gas mass is only a few percent of the total mass. Using the spectroscopic measurements, we also derive radial distributions for the heavy elements silicon and iron and find that the abundances of both decrease with galaxy radius. The mass ratio of Si to Fe lies between the theoretical predictions for element production in SN Ia and SN II, suggesting an important role for SN Ia, as well as SN II, for gas enrichment in ellipticals. Using the 2 SN la yield of Si, we set an upper limit of 0.012 h(sup 2, sub 50) solar neutrino units (SNU) for the SN Ia rate at radii >50 kpc, which is independent of possible uncertainties in the iron L-shell modeling. We compare our observations with the theoretical predictions for the chemical evolution of ellipticals. We conclude that the metal content in stars, if explained by the star formation duration, requires a significant decline in the duration of star formation with galaxy radius, ranging from 1 Gyr at the center to 0.01 Gyr at 100 kpc radius. Alternatively, the decline in metallicity with galaxy radius may be caused by a similar drop with radius in the efficiency of star formation. Based on the Si and Fe measurements presented in this paper, we conclude that the latter scenario is preferred unless a dependence of the SN Ia rate on stellar metallicity is invoked.

  2. Plexiform fibromyxoma with cotyledon-like serosal growth: A case report of a rare gastric tumor and review of the literature

    PubMed Central

    KANE, JOSHUA ROBERT; LEWIS, NATASHA; LIN, REBECCA; VILLA, CELINA; LARSON, ALEXANDRA; WAYNE, JEFFREY D.; YELDANDI, ANJANA V.; LASKIN, WILLIAM B.

    2016-01-01

    Plexiform fibromyxoma is a rare, benign mesenchymal neoplasm that predilects the gastric antrum and has potential for misdiagnosis as a gastrointestinal stromal tumor (GIST). The histology of the tumor is characterized by interwoven fascicular growth of cytologically bland spindled cells within a variably myxoid stroma. The current study reports the clinicopathological and immunohistochemical findings of a plexiform fibromyxoma resected from a 28-year-old Vietnamese female. The patient presented with acute, severe abdominal pain and worsening anemia. The initial fine-needle aspiration and needle core biopsy of the gastric antral mass led to an initial diagnosis of GIST. The subsequent distal partial gastrectomy revealed a 5.5-cm transmural antral mass that ulcerated the overlying mucosa and grew as variably elongated, myxoedematous, polypoid (cotyledon-like) excrescences from the serosal surface. Microscopically, the tumor demonstrated plexiform and multinodular growth of cytologically bland spindled cells proliferating in an abundant myxocollagenous stroma with a prominent capillary network. Tumor cells immunohistochemically expressed smooth muscle actin and CD10, but did not express CD117, Discovered on GIST-1 or nuclear β-catenin. Follow-up evaluation 23 months post surgery revealed no evidence of residual tumor. A review the cases of this rare entity reported in the English language literature is also provided. PMID:26998147

  3. Climatic effects on mosquito abundance in Mediterranean wetlands

    PubMed Central

    2014-01-01

    Background The impact of climate change on vector-borne diseases is highly controversial. One of the principal points of debate is whether or not climate influences mosquito abundance, a key factor in disease transmission. Methods To test this hypothesis, we analysed ten years of data (2003–2012) from biweekly surveys to assess inter-annual and seasonal relationships between the abundance of seven mosquito species known to be pathogen vectors (West Nile virus, Usutu virus, dirofilariasis and Plasmodium sp.) and several climatic variables in two wetlands in SW Spain. Results Within-season abundance patterns were related to climatic variables (i.e. temperature, rainfall, tide heights, relative humidity and photoperiod) that varied according to the mosquito species in question. Rainfall during winter months was positively related to Culex pipiens and Ochlerotatus detritus annual abundances. Annual maximum temperatures were non-linearly related to annual Cx. pipiens abundance, while annual mean temperatures were positively related to annual Ochlerotatus caspius abundance. Finally, we modelled shifts in mosquito abundances using the A2 and B2 temperature and rainfall climate change scenarios for the period 2011–2100. While Oc. caspius, an important anthropophilic species, may increase in abundance, no changes are expected for Cx. pipiens or the salt-marsh mosquito Oc. detritus. Conclusions Our results highlight that the effects of climate are species-specific, place-specific and non-linear and that linear approaches will therefore overestimate the effect of climate change on mosquito abundances at high temperatures. Climate warming does not necessarily lead to an increase in mosquito abundance in natural Mediterranean wetlands and will affect, above all, species such as Oc. caspius whose numbers are not closely linked to rainfall and are influenced, rather, by local tidal patterns and temperatures. The final impact of changes in vector abundance on disease frequency

  4. Differential expression and regulation of vitamin D hydroxylases and inflammatory genes in prostate stroma and epithelium by 1,25-dihydroxyvitamin D in men with prostate cancer and an in vitro model

    PubMed Central

    Giangreco, Angeline A.; Dambal, Shweta; Wagner, Dennis; Van der Kwast, Theodorus; Vieth, Reinhold; Prins, Gail S.; Nonn, Larisa

    2014-01-01

    Previous work on vitamin D in the prostate has focused on the prostatic epithelium, from which prostate cancer arises. Prostatic epithelial cells are surrounded by stroma, which has well-established regulatory control over epithelial proliferation, differentiation, and the inflammatory response. Here we examined the regulation of vitamin D-related genes and inflammatory genes by 1α,25-dihydroxyvitamin D3 (1,25(OH)2D) in laser-capture microdissected prostate tissue from a vitamin D3 clinical trial and in an in vitro model that facilitates stromal–epithelial crosstalk. Analysis of the trial tissues showed that VDR was present in both cell types, whereas expression of the hydroxylases was the highest in the epithelium. Examination of gene expression by prostatic (1,25(OH)2D) concentrations showed that VDR was significantly lower in prostate tissues with the highest concentration of 1,25(OH)2D, and down-regulation of VDR by 1,25(OH) 2D was confirmed in the primary cell cultures. Analysis of inflammatory genes in the patient tissues revealed that IL-6 expression was the highest in the prostate stroma while PTGS2 (COX2) levels were lowest in the prostate cancer tissues from men in the highest tertile of prostatic 1,25(OH)2D. In vitro, TNF-α, IL-6 and IL-8 were suppressed by 1,25 (OH)2D in the primary epithelial cells, whereas TNF-α and PTGS2 were suppressed by 1,25(OH) 2D in the stromal cells. Importantly, the ability of 1,25(OH)2D to alter pro-inflammatory-induced changes in epithelial cell growth were dependent on the presence of the stromal cells. In summary, whereas both stromal and epithelial cells of the prostate express VDR and can presumably respond to 1,25(OH)2D, which appears to be primarily produced by the prostatic epithelium. Further, while the prostate epithelium was more responsive to the anti-inflammatory activity of 1,25 (OH)2D than stromal cells, stroma–epithelial crosstalk enhanced the phenotypic effects of 1,25(OH)2D and the inflammatory

  5. The Abundance and Distribution of Presolar Materials in Cluster IDPS

    NASA Technical Reports Server (NTRS)

    Messenger, Scott; Keller, Lindsay; Nakamura-Messenger, Keiko; Ito, Motoo

    2007-01-01

    Presolar grains and remnants of interstellar organic compounds occur in a wide range of primitive solar system materials, including meteorites, interplanetary dust particles (IDPs), and comet Wild-2 samples. Among the most abundant presolar phases are silicate stardust grains and molecular cloud material. However, these materials have also been susceptible to destruction and alteration during parent body and nebular processing. In addition to their importance as direct samples of remote and ancient astrophysical environments, presolar materials thus provide a measure of how well different primitive bodies have preserved the original solar system starting materials. The matrix normalized abundances of presolar silicate grains in meteorites range from 20 ppm in Semarkona and Bishunpur to 170 ppm for Acfer 094. The lower abundances of presolar silicates in Bishunpur and Semarkona has been ascribed to the destruction of presolar silicates during aqueous processes. Presolar silicates appear to be significantly more abundant in anhydrous IDPs, possibly because these materials did not experience parent body hydrothermal alteration. Among IDPs the estimated abundances of presolar silicates vary by more than an order of magnitude, from 480 to 5500 ppm. The wide disparity in the abundances of presolar silicates of IDPs may be a consequence of the relatively small total area analyzed in those studies and the fine grain sizes of the IDPs. Alternatively, there may be a wide range in presolar silicate abundances between different IDPs. This view is supported by the observation that 15N-rich IDPs have higher presolar silicate abundances than those with isotopically normal N.

  6. LITHIUM ABUNDANCES OF EXTREMELY METAL-POOR TURNOFF STARS

    SciTech Connect

    Aoki, Wako; Inoue, Susumu; Barklem, Paul S.; Beers, Timothy C.; Christlieb, Norbert; Perez, Ana E. GarcIa; Norris, John E.; Carollo, Daniela E-mail: Paul.Barklem@physics.uu.se E-mail: N.Christlieb@lsw.uni-heidelberg.de E-mail: jen@mso.anu.edu.au E-mail: inoue@tap.scphys.kyoto-u.ac.jp

    2009-06-20

    We have determined Li abundances for eleven metal-poor turnoff stars, among which eight have [Fe/H] <-3, based on LTE analyses of high-resolution spectra obtained with the High Dispersion Spectrograph on the Subaru Telescope. The Li abundances for four of these eight stars are determined for the first time by this study. Effective temperatures are determined by a profile analysis of H{alpha} and H{beta}. While seven stars have Li abundances as high as the Spite Plateau value, the remaining four objects with [Fe/H] <-3 have A(Li) =log (Li/H)+ 12 {approx}< 2.0, confirming the existence of extremely metal-poor (EMP) turnoff stars having low Li abundances, as reported by previous work. The average of the Li abundances for stars with [Fe/H]<-3 is lower by 0.2 dex than that of the stars with higher metallicity. No clear constraint on the metallicity dependence or scatter of the Li abundances is derived from our measurements for the stars with [Fe/H]<-3. Correlations of the Li abundance with effective temperatures, with abundances of Na, Mg, and Sr, and with the kinematical properties are investigated, but no clear correlation is seen in the EMP star sample.

  7. Element Abundances in Solar Energetic Particles and the Solar Corona

    NASA Astrophysics Data System (ADS)

    Reames, Donald V.

    2014-03-01

    This is a study of abundances of the elements He, C, N, O, Ne, Mg, Si, S, Ar, Ca, and Fe in solar energetic particles (SEPs) in the 2 - 15 MeV amu-1 region measured on the Wind spacecraft during 54 large SEP events occurring between November 1994 and June 2012. The origin of most of the temporal and spatial variations in abundances of the heavier elements lies in rigidity-dependent scattering during transport of the particles away from the site of acceleration at shock waves driven out from the Sun by coronal mass ejections (CMEs). Variation in the abundance of Fe is correlated with the Fe spectral index, as expected from scattering theory but not previously noted. Clustering of Fe abundances during the "reservoir" period, late in SEP events, is also newly reported. Transport-induced enhancements in one region are balanced by depletions in another, thus, averaging over these variations produces SEP abundances that are energy independent, confirms previous SEP abundances in this energy region, and provides a credible measure of element abundances in the solar corona. These SEP-determined coronal abundances differ from those in the solar photosphere by a well-known function that depends upon the first ionization potential (FIP) or ionization time of the element.

  8. Nucleosynthesis: Stellar and Solar Abundances and Atomic Data

    NASA Technical Reports Server (NTRS)

    Cowan, John J.; Lawler, James E.; Sneden, Christopher; DenHartog, E. A.; Collier, Jason; Dodge, Homer L.

    2006-01-01

    Abundance observations indicate the presence of often surprisingly large amounts of neutron capture (i.e., s- and r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy the progenitors of the halo stars responsible for neutron-capture synthesis. Comparisons of abundance trends can be used to understand the chemical evolution of the Galaxy and the nature of heavy element nucleosynthesis. In addition age determinations, based upon long-lived radioactive nuclei abundances, can now be obtained. These stellar abundance determinations depend critically upon atomic data. Improved laboratory transition probabilities have been recently obtained for a number of elements. These new gf values have been used to greatly refine the abundances of neutron-capture elemental abundances in the solar photosphere and in very metal-poor Galactic halo stars. The newly determined stellar abundances are surprisingly consistent with a (relative) Solar System r-process pattern, and are also consistent with abundance predictions expected from such neutron-capture nucleosynthesis.

  9. Elemental abundances of the B6 IV star Xi Octantis

    NASA Technical Reports Server (NTRS)

    Adelman, Saul J.; Robinson, Richard D.; Wahlgren, Glenn M.

    1993-01-01

    An elemental abundance study used AAT echelle spectrograms of the ultrasharp-lined, superficially normal B6 IV star Xi Octantis. The derived abundances fall within the trends of values derived for normal B main-sequence band stars. On average, they are 0.28 dex less than solar.

  10. Carbon and nitrogen abundances determined from transition layer lines

    NASA Technical Reports Server (NTRS)

    Boehm-Vitense, Erika; Mena-Werth, Jose

    1992-01-01

    The possibility of determining relative carbon, nitrogen, and silicon abundances from the emission-line fluxes in the lower transition layers between stellar chromospheres and coronae is explored. Observations for main-sequence and luminosity class IV stars with presumably solar element abundances show that for the lower transition layers Em = BT sup -gamma. For a given carbon abundance the constants gamma and B in this relation can be determined from the C II and C IV emission-line fluxes. From the N V and S IV lines, the abundances of these elements relative to carbon can be determined from their surface emission-line fluxes. Ratios of N/C abundances determined in this way for some giants and supergiants agree within the limits of errors with those determined from molecular bands. For giants, an increase in the ratio of N/C at B-V of about 0.8 is found, as expected theoretically.

  11. Interstellar Dust Models Consistent with Extinction, Emission, and Abundance Constraints

    NASA Technical Reports Server (NTRS)

    Zubko, Viktor; Dwek, Eli; Arendt, Richard G.

    2004-01-01

    We present new interstellar dust models which have been derived by simultaneously fitting the far ultraviolet to near infrared extinction, the diffuse infrared emission, and, unlike previous models, the elemental abundances in dust for the diffuse interstellar medium. We found that dust models consisting of a mixture of spherical graphite and silicate grains, polycyclic aromatic hydrocarbon (PAH) molecules, in addition to porous composite particles containing silicate, organic refractory, and water ice, provide an improved .t to the UV-to-infrared extinction and infrared emission measurements, while consuming the amounts of elements well within the uncertainties of adopted interstellar abundances, including B star abundances. These models are a signi.cant improvement over the recent Li & Draine (2001, ApJ, 554, 778) model which requires an excessive amount of silicon to be locked up in dust: 48 ppm (atoms per million of H atoms), considerably more than the solar abundance of 34 ppm or the B star abundance of 19 ppm.

  12. Total carbon and sulfur abundances in Antarctic meteorites

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.; Yanai, K.

    1979-01-01

    Total carbon and sulfur abundances have been measured in five Antarctic meteorites. Two C2 carbonaceous chondrites Yamato 74662 and Allan Hills 77306 have sulfur abundances (3.490 plus or minus .040% and 3.863 plus or minus 0.050% respectively) similar to other C2 chondrites but their carbon abundances (1.514 plus or minus 0.050% and 1.324 plus or minus .040% respectively) are lower than previously measured C2 chondrites. The decreased carbon abundances may reflect the effects of weathering in cold environments. Carbon and sulfur abundances for one C4 carbonaceous chondrite, one E4 enstatite chondrite and one ureilite are similar to values reported previously for meteorites of the same petrologic grades.

  13. An "Andesitic" Component in Shergottites with Restored LREE Abundances?

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Shih, C.-Y.; Wiesmann, H.; Barrat, J. A.

    2002-01-01

    The shergottite Martian meteorites present a variety of oft-confusing petrologic features. In particular, represented among this subgroup are basalts with very depleted LREE abundances, as well as those with nearly chondritic overall REE abundances. The LREE-depleted basalts appear to more closely record the REE and isotopic features of their mantle source legions. Those basalts with more nearly chondritic REE abundances appear to contain an extra component often referred to as a "crustal" component. The addition of the crustal component tends to restore the overall REE abundance pattern towards chondritic relative abundances. Here we suggest that the crustal component could derive from andesitic rocks observed remotely to occur on the Martian surface, and which were analysed at the Pathfinder site.

  14. An "Andestic" Component in Shergottites with Restored LREE Abundances?

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Shih, C.-Y.; Wiesmann, H.; Barrat, J. A.

    2002-01-01

    The shergottite Martian meteorites present a variety of oft-confusing petrologic features. In particular, represented among this subgroup are basalts with very depleted LREE abundances, as well as those with nearly chondritic overall REE abundances. The LREE-depleted basalts appear to more closely record the REE and isotopic features of their mantle source regions. Those basalts with more nearly chondritic REE abundances appear to contain an extra component often referred to as a "crustal" component. The addition of the crustal component tends to restore the overall REE abundance pattern towards chondritic relative abundances. Here we suggest that the crustal component could derive from "andesitic" rocks observed remotely to occur on the Martian surface, and which were analysed at the Pathfinder site.

  15. Abundance recovery error analysis using simulated AVIRIS data

    NASA Technical Reports Server (NTRS)

    Stoner, William W.; Harsanyi, Joseph C.; Farrand, William H.; Wong, Jennifer A.

    1992-01-01

    Measurement noise and imperfect atmospheric correction translate directly into errors in the determination of the surficial abundance of materials from imaging spectrometer data. The effects of errors on abundance recovery were investigated previously using Monte Carlo simulation methods by Sabol et. al. The drawback of the Monte Carlo approach is that thousands of trials are needed to develop good statistics on the probable error in abundance recovery. This computational burden invariably limits the number of scenarios of interest that can practically be investigated. A more efficient approach is based on covariance analysis. The covariance analysis approach expresses errors in abundance as a function of noise in the spectral measurements and provides a closed form result eliminating the need for multiple trials. Monte Carlo simulation and covariance analysis are used to predict confidence limits for abundance recovery for a scenario which is modeled as being derived from Airborne Visible/Infrared Imaging Spectrometer (AVIRIS).

  16. Recombination Line vs. Forbidden Line Abundances in Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Robertson-Tessi, M.; Garnett, D. R.

    2004-05-01

    Recombination lines (RLs) of C II, N II, and O II in planetary nebulae (PNe) have been found to give abundances that are much larger in some cases than abundances from collisionally-excited forbidden lines (CELs). The origins of this abundance discrepancy are highly debated. We present new spectroscopic observations of O II and C II recombination lines for six planetary nebulae. With these data we compare the abundances derived from the optical recombination lines with those determined from collisionally-excited lines. Combining our new data with published results on RLs in other PNe, we examine the discrepancy in abundances derived from RLs and CELs. We find that there is a wide range in the measured abundance discrepancy Δ (O+2) = log O+2(RL) - log O+2(CEL), ranging from approximately 0.1 dex (within the 1σ measurement errors) up to 1.3 dex. This tends to rule out errors in the recombination coefficients as a source of the discrepancy. Most RLs yield similar abundances, with the notable exception of O II multiplet V15, known to arise primarily from dielectronic recombination, which gives abundances averaging 0.6 dex higher than other O II RLs. We compare Δ (O+2) against a variety of physical properties of the PNe to look for clues as to the mechanism responsible for the abundance discrepancy. The strongest correlation is found with Balmer surface brightness; high surface brightness, compact PNe show small values of Δ (O+2), while large low surface brightness PNe show the largest discrepancies. Rougher correlations of Δ (O+2) are found with He+2/He+ and with the expansion velocity. No correlations are seen with electron temperature, electron density, central star effective temperature and luminosity, stellar mass loss rate, or nebular morphology. Similar results are found for carbon, comparing C II RL abundances with ultraviolet measurements of C III]. This work is supported by NSF grant AST-0203905.

  17. Carbon and nitrogen abundance variations in globular cluster red giants

    NASA Astrophysics Data System (ADS)

    Martell, Sarah L.

    2008-06-01

    This dissertation describes investigations into two of the persistent questions of elemental abundances in Galactic globular clusters: the phenomenon of deep mixing, observed through the progressive depletion of surface carbon abundance as stars evolve along the red giant branch, and abundance bimodality, a phenomenon observed only in globular clusters, in which a subset of stars in a given globular cluster have a distinctive pattern of elemental enhancements and depletions relative to the Solar pattern. The first chapter gives an introduction to the history of globular cluster abundance studies, with particular focus on low-resolution spectroscopy. For both deep mixing and abundance bimodality, the leading theoretical models and the data which support and challenge them are laid out. Each section ends with a description of presently-unanswered questions; these are the motivation for the various projects contained in this dissertation. The second chapter describes the use of molecular handstrengths for determining elemental abundances from low-resolution spectra, and introduces a new CH bandstrength index that is designed to be sensitive to carbon abundance and insensitive to nitrogen abundance in Pop. II red giants over a wide range of metallicity. Various CH indices defined elsewhere in the literature are also discussed, and are shown to have comparable accuracy to the new index only over a limited range of stellar properties. Carbon abundances determined using the new CH index are compared to literature abundances for a few stars, and general concordance with published abundances is found. The third chapter contains a large-scale application of the new CH index: a survey of present-day carbon abundances and calculated carbon depletion rates in bright red giants belonging to eleven Galactic globular clusters spanning the full metallicity range of halo globular clusters. Targets were selected with similar evolutionary states, were observed with one instrument on

  18. Influence of deer abundance on the abundance of questing adult Ixodes scapularis (Acari: Ixodidae)

    USGS Publications Warehouse

    Ginsberg, H.S.; Zhioua, E.

    1999-01-01

    Nymphal and adult Ixodes scapularis Say were sampled by flagging at 2 sites on a barrier island, Fire Island, NY, and at 2 sites on the nearby mainland. Nymphal densities did not differ consistently between island and mainland sites, but adult densities were consistently lower on the island. We tested whether lower adult densities on the island resulted from greater nymphal mortality on the island than the mainland, or whether adult ticks on the island were poorly sampled by flagging because they had attached abundantly to deer, which were common on Fire Island. Differential nymphal mortality on islands vs. mainland did not explain this difference in adult densities because survival of flat and engorged nymphs in enclosures was the same at island and mainland sites. Ticks were infected by parasitic wasps on the island and not the mainland, but the infection rate (4.3%) was too low to explain the difference in adult tick densities. In contrast, exclusion of deer by game fencing on Fire Island resulted in markedly increased numbers of adult ticks in flagging samples inside compared to samples taken outside the exclosures. Therefore, the scarcity of adult ticks in flagging samples on Fire Island resulted, at least in part, from the ticks being unavailable to flagging samples because they were on deer hosts. Differences in the densities of flagged ticks inside and outside the exclosures were used to estimate the percentage of questing adults on Fire Island that found deer hosts, excluding those that attached to other host species. Approximately 56% of these questing adult ticks found deer hosts in 1995 and 50% found deer hosts in 1996. Therefore, in areas where vertebrate hosts are highly abundant, large proportions of the questing tick population can find hosts. Moreover, comparisons of tick densities at different sites by flagging can potentially be biased by differences in host densities among sites.

  19. Model reduction for stochastic chemical systems with abundant species.

    PubMed

    Smith, Stephen; Cianci, Claudia; Grima, Ramon

    2015-12-01

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems. PMID:26646867

  20. Stellar abundances in the solar neighborhood: The Hypatia Catalog

    SciTech Connect

    Hinkel, Natalie R.; Timmes, F.X.; Young, Patrick A.; Pagano, Michael D.; Turnbull, Margaret C.

    2014-09-01

    We compile spectroscopic abundance data from 84 literature sources for 50 elements across 3058 stars in the solar neighborhood, within 150 pc of the Sun, to produce the Hypatia Catalog. We evaluate the variability of the spread in abundance measurements reported for the same star by different surveys. We also explore the likely association of the star within the Galactic disk, the corresponding observation and abundance determination methods for all catalogs in Hypatia, the influence of specific catalogs on the overall abundance trends, and the effect of normalizing all abundances to the same solar scale. The resulting stellar abundance determinations in the Hypatia Catalog are analyzed only for thin-disk stars with observations that are consistent between literature sources. As a result of our large data set, we find that the stars in the solar neighborhood may reveal an asymmetric abundance distribution, such that a [Fe/H]-rich group near the midplane is deficient in Mg, Si, S, Ca, Sc II, Cr II, and Ni as compared to stars farther from the plane. The Hypatia Catalog has a wide number of applications, including exoplanet hosts, thick- and thin-disk stars, and stars with different kinematic properties.

  1. Spatial patterns in the abundance of the coastal horned lizard

    USGS Publications Warehouse

    Fisher, R.N.; Suarez, A.V.; Case, T.J.

    2002-01-01

    Coastal horned lizards (Phrynosoma coronatum) have undergone severe declines in southern California and are a candidate species for state and federal listing tender the Endangered Species Act. Quantitative data on their habitat use, abundance, and distribution are lacking, however. We investigated the determinants of abundance for coastal horned lizards at multiple spatial scales throughout southern California. Specifically, we estimated lizard distribution and abundance by establishing 256 pitfall trap arrays clustered within 21 sites across four counties. These arrays were sampled bimonthly for 2-3 years. At each array we measured 26 "local" site descriptors and averaged these values with other "regional" measures to determine site characteristics. Our analyses were successful at identifying factors within and among sites correlated with the presence and abundance of coastal horned lizards. These factors included the absence of the invasive Argentine ant (Linepithema humile) (and presence of native ant species eaten by the lizards), the presence of chaparral community plants, and the presence of sandy substrates. At a regional scale the relative abundance of Argentine ants was correlated with the relative amount of developed edge around a site. There was no evidence for spatial autocorrelation, even at the scale of the arrays within sites, suggesting that the determinants of the presence or absence and abundance of horned lizard can vary over relatively small spatial scales (hundreds of meters). Our results suggest that a gap-type approach may miss some of the fine-scale determinants of species abundance in fragmented habitats.

  2. A Semi-automated Abundance Survey of Ap Stars

    NASA Astrophysics Data System (ADS)

    Hall, Martin P.; Kurtz, Don; Elkin, Vladimir; Bruntt, Hans

    2015-08-01

    We have carried out an abundance analysis on the high-resolution spectra of approximately 350 Ap stars collected between 2007 and 2010 on the FEROS Echelle (Fibre-led, Extended Range, Echelle ) spectrograph housed at the 2.2-m telescope at European Southern Observatory at La Silla, Chile. We employed the VWA package (vsin I, wavelength shift, abundance analysis) for preliminary selection of spectral lines, and a semi-automated set of routines which we developed in the programming language IDL, to calculate the equivalent widths and abundances of ions of Iron and the rare earth elements Neodymium and Praseodymium using the WIDTH program and NEMO model atmospheres. Initial results are presented, which reinforce the correlation between iron abundance and effective temperature, from an over-abundance in the late Bp stars, to under-abundant in the early F stars. Results also suggest that the disequilibrium in abundances of the first and second ionisation stages of these ions in the rapidly oscillating Ap (roAp) stars may a consequence of the relatively cool temperatures of those stars, rather than a signature of pulsation.

  3. Model reduction for stochastic chemical systems with abundant species

    NASA Astrophysics Data System (ADS)

    Smith, Stephen; Cianci, Claudia; Grima, Ramon

    2015-12-01

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems.

  4. Geographical Range and Local Abundance of Tree Species in China

    PubMed Central

    Ren, Haibao; Condit, Richard; Chen, Bin; Mi, Xiangcheng; Cao, Min; Ye, Wanhui; Hao, Zhanqing; Ma, Keping

    2013-01-01

    Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1) whether locally abundant species tend to be geographically widespread; 2) whether species are more abundant towards their range-centers; and 3) how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20–25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km2, and >90% of 651 species had ranges >105 km2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species’ abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges. PMID:24130772

  5. Dam removal increases American eel abundance in distant headwater streams

    USGS Publications Warehouse

    Hitt, Nathaniel P.; Eyler, Sheila; Wofford, John E.B.

    2012-01-01

    American eel Anguilla rostrata abundances have undergone significant declines over the last 50 years, and migration barriers have been recognized as a contributing cause. We evaluated eel abundances in headwater streams of Shenandoah National Park, Virginia, to compare sites before and after the removal of a large downstream dam in 2004 (Embrey Dam, Rappahannock River). Eel abundances in headwater streams increased significantly after the removal of Embrey Dam. Observed eel abundances after dam removal exceeded predictions derived from autoregressive models parameterized with data prior to dam removal. Mann–Kendall analyses also revealed consistent increases in eel abundances from 2004 to 2010 but inconsistent temporal trends before dam removal. Increasing eel numbers could not be attributed to changes in local physical habitat (i.e., mean stream depth or substrate size) or regional population dynamics (i.e., abundances in Maryland streams or Virginia estuaries). Dam removal was associated with decreasing minimum eel lengths in headwater streams, suggesting that the dam previously impeded migration of many small-bodied individuals (<300 mm TL). We hypothesize that restoring connectivity to headwater streams could increase eel population growth rates by increasing female eel numbers and fecundity. This study demonstrated that dams may influence eel abundances in headwater streams up to 150 river kilometers distant, and that dam removal may provide benefits for eel management and conservation at the landscape scale.

  6. Model reduction for stochastic chemical systems with abundant species

    SciTech Connect

    Smith, Stephen; Cianci, Claudia; Grima, Ramon

    2015-12-07

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems.

  7. OH Column Abundance Apparent Response to Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Burnett, C. R.; Minschwaner, K. R.

    2009-12-01

    The 33-year series of high spectral resolution measurements of absorption of sunlight by OH at 308 nm has exhibited temporary decreases of column abundances in 1986, 1997, and 2008 near the times of minimum solar activity. These observations and analyses are of significance as they encompass three complete solar cycles for comparison. During solar cycle 23, the annual average abundances increased approximately 20% from the minimum abundance in 1997 to high-sun enhanced values in 2000-2006, then dropped approximately 15% in 2008. The abundances exhibited a pronounced reduction at solar minimum in August-October 2008, similar to that seen in fall 1986 and fall 1997. The average morning abundances on those occasions were 13% smaller than the 1980-88 corresponding average, about 0.9 x 1013 cm-2, with minimum values broadly consistent with model results. In contrast, high-sun OH abundances observed during periods of solar maximum are approximately 33% larger than modeled abundances. This discrepancy cannot be explained by reasonable adjustments of reaction rates or modeled constituent concentrations in the stratosphere or mesosphere. However, the observed responses to a tropopause fold event in 1988 and to the Pinatubo aerosol in 1991 do suggest an important contribution to the total OH column from the lower stratosphere. In addition to the apparent variations with solar activity, this OH column database contains a number of other effects such as diurnal and seasonal patterns, and geographic differences between observations from Colorado, Florida, Alaska, Micronesia, New Zealand, and New Mexico.

  8. Seasonal Abundance of Aphids and Aphidophagous Insects in Pecan.

    PubMed

    Dutcher, James D; Karar, Haider; Abbas, Ghulam

    2012-01-01

    Seasonal occurrence of aphids and aphidophagous insects was monitored for six years (2006-2011) from full leaf expansion in May to leaf fall in October in "Desirable" variety pecan trees that were not treated with insecticides. Aphid outbreaks occurred two times per season, once in the spring and again in the late summer. Yellow pecan and blackmargined aphids exceeded the recommended treatment thresholds one time and black pecan aphids exceeded the recommended treatment levels three times over the six seasons. Increases in aphidophagous insect abundance coincided with aphid outbreaks in five of the six seasons. Among aphidophagous insects Harmonia axyridis and Olla v-nigrum were frequently collected in both the tree canopy and at the ground level, whereas, Coccinella septempunctata, Hippodamia convergens were rarely found in the tree canopy and commonly found at the ground level. Green lacewing abundance was higher in the ground level than in the tree canopy. Brown lacewings were more abundant in the tree canopy than at the ground level. Dolichopodid and syrphid fly abundance, at the ground level increased during peak aphid abundance in the tree canopy. Application of an aqueous solution of fermenting molasses to the pecan foliage during an aphid outbreak significantly increased the abundance of ladybeetles and lacewings and significantly reduced the abundance of yellow pecan, blackmargined and black pecan aphids. PMID:26466738

  9. Abundance Inequality in Freshwater Communities Has an Ecological Origin.

    PubMed

    Passy, Sophia I

    2016-04-01

    The hollow-shaped species abundance distribution (SAD) and its allied rank abundance distribution (RAD)-showing that abundance is unevenly distributed among species-are some of the most studied patterns in ecology. To explain the nature of abundance inequality, I developed a novel framework identifying environmental favorability, which controls the balance between reproduction and immigration, as the ultimate source and species stress tolerance as a proximate factor. Thus, under harsh conditions, only a few tolerant species can reproduce, while some sensitive species can be present in low numbers due to chance immigration. This would lead to high abundance inequality between the two groups of species. Under benign conditions, both groups can reproduce and give rise to higher abundance equality. To test these ideas, I examined the variability in the parameters of a Poisson lognormal fit of the SAD and a square root fit of the RAD in diatom and fish communities across US streams. Indeed, as environmental favorability increased, more sensitive forms were able to establish large populations, diminishing the abundance disparity between locally common and rare species. Finally, it was demonstrated that in diatoms, the RAD belonged to the same family of relationships as those of population density with body size and regional distribution. PMID:27028078

  10. How Ants Drop Out: Ant Abundance on Tropical Mountains

    PubMed Central

    Longino, John T.; Branstetter, Michael G.; Colwell, Robert K.

    2014-01-01

    In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica) and examined the impact of elevation (as a proxy for temperature) and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops. PMID:25098722

  11. The determination of electron abundances in interstellar clouds

    NASA Technical Reports Server (NTRS)

    Wootten, A.; Snell, R.; Glassgold, A. E.

    1979-01-01

    An independent method is proposed for the determination of electron abundances in dense clouds based upon the abundance ratio of HCO(+) and CO. The method is derived from a simple application of gas phase ion molecule interstellar chemistry. It is noted that unlike the fractionation of deuterated molecules, it applies to warm as well as to cool clouds. The method is illustrated with the results of the recent abundance survey of Wooten et al. (1978). Finally, it is shown that in cases where deuterium enhancement is measured, an upper limit can be obtained for the cosmic ray ionization rate.

  12. Dust formation in a galaxy with primitive abundances.

    PubMed

    Sloan, G C; Matsuura, M; Zijlstra, A A; Lagadec, E; Groenewegen, M A T; Wood, P R; Szyszka, C; Bernard-Salas, J; van Loon, J Th

    2009-01-16

    Interstellar dust plays a crucial role in the evolution of galaxies. It governs the chemistry and physics of the interstellar medium. In the local universe, dust forms primarily in the ejecta from stars, but its composition and origin in galaxies at very early times remain controversial. We report observational evidence of dust forming around a carbon star in a nearby galaxy with a low abundance of heavy elements, 25 times lower than the solar abundance. The production of dust by a carbon star in a galaxy with such primitive abundances raises the possibility that carbon stars contributed carbonaceous dust in the early universe. PMID:19150838

  13. Abundances of energy spectra of individual iron-secondary elements

    NASA Technical Reports Server (NTRS)

    Israel, M. H.; Klarmann, J.; Love, P. L.; Tueller, J.

    1980-01-01

    Relative abundances of individual Iron-secondary elements have been measured using a balloon-borne 6.6 m ster ionization/Cerenkov detector system. The unusually large geometry factor and single-charge resolution yield empirical atmospheric attenuation curves for individual elements which combine with high statistics at float altitude to yield individual element abundances, extrapolated to the top of the atmosphere, with high precision. Results are presented for top-of-the-atmosphere abundances (relative to iron) of individual elements in the Z range 13-30.

  14. Trace-element abundances in several new ureilites

    NASA Technical Reports Server (NTRS)

    Boynton, William V.; Hill, Dolores H.

    1993-01-01

    Four new ureilites are analyzed for trace-element abundances. Frontier Mountain (FRO) 90054 is an augite-rich ureilite and has high rare earth element (REE) abundances with a pattern expected of augite. FRO 90036 and Acfer 277 have REE patterns similar to the V-shape pattern of other ureilites. Nuevo Mercurio (b)