WorldWideScience

Sample records for cellular pituitary crosstalk

  1. Cellular and molecular specificity of pituitary gland physiology.

    Science.gov (United States)

    Perez-Castro, Carolina; Renner, Ulrich; Haedo, Mariana R; Stalla, Gunter K; Arzt, Eduardo

    2012-01-01

    The anterior pituitary gland has the ability to respond to complex signals derived from central and peripheral systems. Perception of these signals and their integration are mediated by cell interactions and cross-talk of multiple signaling transduction pathways and transcriptional regulatory networks that cooperate for hormone secretion, cell plasticity, and ultimately specific pituitary responses that are essential for an appropriate physiological response. We discuss the physiopathological and molecular mechanisms related to this integrative regulatory system of the anterior pituitary gland and how it contributes to modulate the gland functions and impacts on body homeostasis. PMID:22298650

  2. Microparticles as mediators of cellular cross-talk in inflammatory disease.

    Science.gov (United States)

    Distler, Jörg H W; Huber, Lars C; Gay, Steffen; Distler, Oliver; Pisetsky, David S

    2006-12-01

    Microparticles are a heterogeneous population of membrane-coated vesicles which can be released from virtually all cell types during activation or apoptosis. Release occurs from the cell surface in an exogenous budding process involving local rearrangement of the cytoskeleton. Given their origin, these particles can be identified by staining for cell surface markers and annexin V. As shown in in vitro studies, microparticles may represent a novel subcellular element for intercellular communication in inflammation. Thus, microparticles can transfer chemokine receptors and arachidonic acid between cells, activate complement, promote leukocyte rolling and stimulate the release of pro-inflammatory mediators. Under certain conditions, however, microparticles may also exert anti-inflammatory properties by inducing immune cell apoptosis and the production of anti-inflammatory mediators. Microparticles may play an important role in the pathogenesis of rheumatologic diseases as evidenced by their elevation in diseases such as systemic sclerosis (SSc), systemic vasculitis and antiphospholipid antibody syndrome and correlation with clinical events. A role in inflammatory arthritis is suggested by the finding that leukocyte-derived microparticles induce the production of matrix metalloproteinases and cytokines by synovial fibroblasts. Together, these findings point to novel signaling pathways of cellular cross-talk that may operate along the spectrum of soluble cytokines and mediators of direct cell-cell contact. PMID:17178565

  3. Role of Hepatic Progenitor Cells in Nonalcoholic Fatty Liver Disease Development: Cellular Cross-Talks and Molecular Networks

    Directory of Open Access Journals (Sweden)

    Eugenio Gaudio

    2013-10-01

    Full Text Available Nonalcoholic fatty liver disease (NAFLD includes a spectrum of diseases ranging from simple fatty liver to nonalcoholic steatohepatitis, (NASH which may progress to cirrhosis and hepatocellular carcinoma. NASH has been independently correlated with atherosclerosis progression and cardiovascular risk. NASH development is characterized by intricate interactions between resident and recruited cells that enable liver damage progression. The increasing general agreement is that the cross-talk between hepatocytes, hepatic stellate cells (HSCs and macrophages in NAFLD has a main role in the derangement of lipid homeostasis, insulin resistance, danger recognition, immune tolerance response and fibrogenesis. Moreover, several evidences have suggested that hepatic stem/progenitor cell (HPCs activation is a component of the adaptive response of the liver to oxidative stress in NAFLD. HPC activation determines the appearance of a ductular reaction. In NASH, ductular reaction is independently correlated with progressive portal fibrosis raising the possibility of a periportal fibrogenetic pathway for fibrogenesis that is parallel to the deposition of subsinusoidal collagen in zone 3 by HSCs. Recent evidences indicated that adipokines, a class of circulating factors, have a key role in the cross-talk among HSCs, HPCs and liver macrophages. This review will be focused on cellular cross-talk and the relative molecular networks which are at the base of NASH progression and fibrosis.

  4. Prolactin kinase activity in bovine anterior pituitary sub-cellular fractions.

    Science.gov (United States)

    Wicks, J R; Brooks, C L

    1999-01-25

    Bovine anterior pituitary cells phosphorylate prolactin (PRL). We describe the phosphorylation of endogenous and exogenous bPRL in highly enriched subcellular fractions of bovine anterior pituitary using [gamma-32P]-ATP. 32P-labeling of endogenous and exogenous bPRL occurred in all subcellular membrane fractions, but most significantly in the fraction enriched for secretory granules. Zn2+ (0.8 mM), Cu2+ (0.8 mM), and Mn2+ (9.8 mM) increased bPRL phosphorylation by 268, 214, and 154%, respectively, relative to basal phosphorylation with no added cations. Neither Mg2+ (10 mM) nor Ca2+ (0.9 mM) increased bPRL phosphorylation above basal levels. Phosphorylation was dependent on the concentration of Zn2+ with an apparent Km of 570 microM. bPRL phosphorylation occurred over a wide pH range of 5.9-8.3, with the greatest activity at pH of 6.7 or greater. Phosphorylation of bPRL was time-dependent. The apparent Kms of the bPRL kinase for exogenous bPRL and ATP were 15.3 and 267 microM, respectively. bPRL incorporation of 32P was unaffected by the presence of calcium and calmodulin, cAMP, phosphotidylserine and diolein, or spermine. From these results we conclude that in vitro phosphorylation of bPRL occurs under physiological conditions that would be found in pituitary cells. PMID:10195699

  5. Pituitary Tumors

    Science.gov (United States)

    ... Tumors Oligoastrocytoma Oligodendroglioma Pineal Tumor Pituitary Tumor PNET Schwannoma Risk Factors Brain Tumor Facts Brain Tumor Dictionary ... Tumors Oligoastrocytoma Oligodendroglioma Pineal Tumor Pituitary Tumor PNET Schwannoma Risk Factors Brain Tumor Facts Brain Tumor Dictionary ...

  6. Pituitary apoplexy

    Science.gov (United States)

    ... and you have already been diagnosed with a pituitary tumor, seek medical help right away. ... Melmed S, Kleinberg D. Pituitary masses and tumors. In: Melmed S, ... of Endocrinology. 12th ed. Philadelphia, Pa: Elsevier Saunders; ...

  7. Pituitary apoplexy

    Science.gov (United States)

    ... LH Prolactin TSH Insulin-like growth factor-1 (IGF-1) Sodium Osmolarity in blood and urine ... The outlook is good for people who have long-term (chronic) pituitary deficiency that is diagnosed and ...

  8. Pituitary apoplexy

    Directory of Open Access Journals (Sweden)

    Salam Ranabir

    2011-01-01

    Full Text Available Pituitary apoplexy is rare endocrine emergency which can occur due to infarction or haemorrhage of pituitary gland. This disorder most often involves a pituitary adenoma. Occasionally it may be the first manifestation of an underlying adenoma. There is conflicting data regarding which type of pituitary adenoma is prone for apoplexy. Some studies showed predominance of non-functional adenomas while some other studies showed a higher prevalence in functioning adenomas amongst which prolactinoma have the highest risk. Although pituitary apoplexy can occur without any precipitating factor in most cases, there are some well recognizable risk factors such as hypertension, medications, major surgeries, coagulopathies either primary or following medications or infection, head injury, radiation or dynamic testing of the pituitary. Patients usually present with headache, vomiting, altered sensorium, visual defect and/or endocrine dysfunction. Hemodynamic instability may be result from adrenocorticotrophic hormone deficiency. Imaging with either CT scan or MRI should be performed in suspected cases. Intravenous fluid and hydrocortisone should be administered after collection of sample for baseline hormonal evaluation. Earlier studies used to advocate urgent decompression of the lesion but more recent studies favor conservative approach for most cases with surgery reserved for those with deteriorating level of consciousness or increasing visual defect. The visual and endocrine outcomes are almost similar with either surgery or conservative management. Once the acute phase is over, patient should be re-evaluated for hormonal deficiencies.

  9. Inflammatory Pseudotumor of the Pituitary Gland Mimicking a Pituitary Adenoma: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Da Mi; Yu, In Kyu [Dept. of Radiology, Eulji University Hospital, Daejeon (Korea, Republic of); Kim, Han Kyu [Dept. of Neurosurgery, Eulji University Hospital, Daejeon (Korea, Republic of); Son Hyun Jin [Dept. of Pathology, Eulji University Hospital, Daejeon (Korea, Republic of)

    2011-04-15

    A 38-year-old man was admitted to our hospital with diplopia. The patient had a relatively well-defined pituitary mass with high cellularity as well as weaker enhancement on imaging modalities including computed tomography (CT) and magnetic resonance imaging (MRI), than a typical pituitary adenoma. The distinction between a pseudotumor and an invasive neoplasm is very difficult before biopsy. In this case report, we discuss the characteristic imaging features of a fibrosing inflammatory pseudotumor of the pituitary gland

  10. Pituitary Disorders Treatment Options

    Science.gov (United States)

    ... types of drugs can help relieve pituitary problems. Prolactinomas, for example, respond well to a dopamine agonist ... is caused by the treatment you have for pituitary tumors. Surgery or radiation therapy, for example, can lead ...

  11. Pituitary tumors containing cholecystokinin

    DEFF Research Database (Denmark)

    Rehfeld, J F; Lindholm, J; Andersen, B N;

    1987-01-01

    We found small amounts of cholecystokinin in the normal human adenohypophysis and therefore examined pituitary tumors from 87 patients with acromegaly, Cushing's disease, Nelson's syndrome, prolactinoma, or inactive pituitary adenomas. Five adenomas associated with Nelson's syndrome contained...

  12. Crosstalk between mitochondria and NADPH oxidases

    OpenAIRE

    Dikalov, Sergey

    2011-01-01

    Reactive oxygen species (ROS) play an important role in physiological and pathological processes. In recent years, a feed-forward regulation of the ROS sources has been reported. The interaction between main cellular sources of ROS, such as mitochondria and NADPH oxidases, however, remain obscure. This work summarizes the latest findings on the role of crosstalk between mitochondria and NADPH oxidases in pathophysiological processes. Mitochondria have the highest levels of antioxidants in the...

  13. Pituitary tumors containing cholecystokinin

    DEFF Research Database (Denmark)

    Rehfeld, J F; Lindholm, J; Andersen, B N;

    1987-01-01

    We found small amounts of cholecystokinin in the normal human adenohypophysis and therefore examined pituitary tumors from 87 patients with acromegaly, Cushing's disease, Nelson's syndrome, prolactinoma, or inactive pituitary adenomas. Five adenomas associated with Nelson's syndrome contained......'s disease and 7 acromegaly with adenomas containing ACTH. The cholecystokinin peptides from the tumors were smaller and less sulfated than cholecystokinin from normal pituitary glands. We conclude that ACTH-producing pituitary cells may also produce an altered form of cholecystokinin....

  14. Modeling crosstalk in silicon photomultipliers

    OpenAIRE

    Gallego, L.; Rosado Vélez, Jaime; Arqueros Martínez, Fernando

    2013-01-01

    Optical crosstalk seriously limits the photon-counting resolution of silicon photomultipliers. In this work, realistic analytical models to describe the crosstalk effects on the response of these photodetectors are presented and compared with experimental data. The proposed models are based on the hypothesis that each pixel of the array has a finite number of available neighboring pixels to excite via crosstalk. Dead-time effects and geometrical aspects of the propagation of crosstalk between...

  15. Pregnancy and pituitary adenomas.

    Science.gov (United States)

    Glezer, Andrea; Jallad, Raquel S; Machado, Marcio C; Fragoso, Maria C; Bronstein, Marcello D

    2016-09-01

    Infertility is frequent in patients harboring pituitary adenomas. The mechanisms involved include hypogonadism secondary to hormonal hypersecretion (prolactin, growth hormone and cortisol), stalk disconnection and pituitary damage. With the improvement of clinical and surgical treatment, pregnancy in women harboring pituitary adenomas turned into a reality. Pituitary hormonal hyper- and hyposecretion influences pregnancy outcomes, as well as pregnancy can interfere on pituitary tumors, especially in prolactinomas. We review literature about specific follow-up and management in pregnant women harboring prolactinomas, acromegaly, or Cushings disease and the impact of clinical and surgical treatment on each condition. PMID:26977888

  16. Modeling crosstalk in silicon photomultipliers

    CERN Document Server

    Gallego, L; Blanco, F; Arqueros, F

    2013-01-01

    Optical crosstalk seriously limits the photon-counting resolution of silicon photomultipliers. In this work, realistic analytical models to describe the crosstalk effects on the response of these photodetectors are presented and compared with experimental data. The proposed models are based on the hypothesis that each pixel of the array has a finite number of available neighboring pixels to excite via crosstalk. Dead-time effects and geometrical aspects of the propagation of crosstalk between neighbors are taken into account in the models for different neighborhood configurations. Simple expressions to account for crosstalk effects on the pulse-height spectrum as well as to evaluate the excess noise factor due to crosstalk are also given. Dedicated measurements were carried out under both dark-count conditions and pulsed illumination. Moreover, the influence of afterpulsing on the measured pulse-height spectrum was studied, and a measurement of the recovery time of pixels was reported. High-resolution pulse-h...

  17. MRI in haemochromatosis: pituitary versus testicular iron deposition in five patients with hypogonadism

    Energy Technology Data Exchange (ETDEWEB)

    Miaux, Y. [Dept. of Radiology, Hopital Saint-Louis, 75 Paris (France); Daurelle, P. [Dept. of Endocrinology, Hopital Saint-Louis, 75 Paris (France); Zagdanski, A.M. [Dept. of Radiology, Hopital Saint-Louis, 75 Paris (France); Passa, P. [Dept. of Endocrinology, Hopital Saint-Louis, 75 Paris (France); Bourrier, P. [Dept. of Radiology, Hopital Saint-Louis, 75 Paris (France); Frija, J. [Dept. of Radiology, Hopital Saint-Louis, 75 Paris (France)

    1995-08-01

    Haemochromatosis is a disease characterised by iron deposition in the liver and other organs. Hypogonadism is a commonly associated condition and may be either primary due to testicular lesions or secondary due to pituitary dysfunction. Hypogonadism secondary to pituitary dysfunction is more frequent and is thought to be related to iron deposition in the anterior pituitary. Increased iron content decreases signal intensity of spin-echo MRI images because T2 values are significantly shortened. Our purpose in this study was to evaluate by MRI iron deposition in the liver, testis and pituitary of 6 patients with haemochromatosis and severe hypogonadotrophic hypogonadism. Six subjects served as controls. There was a significant T2 shortening of the liver and pituitary in patients with haemochromatosis compared with control patients. Therefore MRI detected iron overload in the pituitary and no iron in the testis, supporting the hypothesis of hypogonadotrophic pituitary insufficiency due to cellular damage induced by iron overload in the anterior pituitary gland. (orig.)

  18. Modelling and Analysis of Biochemical Signalling Pathway Cross-talk

    Directory of Open Access Journals (Sweden)

    Robin Donaldson

    2010-02-01

    Full Text Available Signalling pathways are abstractions that help life scientists structure the coordination of cellular activity. Cross-talk between pathways accounts for many of the complex behaviours exhibited by signalling pathways and is often critical in producing the correct signal-response relationship. Formal models of signalling pathways and cross-talk in particular can aid understanding and drive experimentation. We define an approach to modelling based on the concept that a pathway is the (synchronising parallel composition of instances of generic modules (with internal and external labels. Pathways are then composed by (synchronising parallel composition and renaming; different types of cross-talk result from different combinations of synchronisation and renaming. We define a number of generic modules in PRISM and five types of cross-talk: signal flow, substrate availability, receptor function, gene expression and intracellular communication. We show that Continuous Stochastic Logic properties can both detect and distinguish the types of cross-talk. The approach is illustrated with small examples and an analysis of the cross-talk between the TGF-b/BMP, WNT and MAPK pathways.

  19. Double pituitary adenomas.

    Science.gov (United States)

    Iacovazzo, D; Bianchi, A; Lugli, F; Milardi, D; Giampietro, A; Lucci-Cordisco, E; Doglietto, F; Lauriola, L; De Marinis, L

    2013-04-01

    Double pituitary adenomas represent up to 2.6 % of pituitary adenomas in large surgical series and up to 3.3 % of patients with Cushing's disease have been found to have double or multiple pituitary adenomas. We report the case of a 60-year-old male patient whose medical history began in 2002 with erectile dysfunction; hyperprolactinemia was found and MRI showed a 6-mm area of delayed enhancement in the lateral portion of the right pituitary lobe. Treatment with cabergoline was started with normalization of prolactin levels; the following MRI, performed in 2005 and 2008, showed shrinkage of the pituitary lesion. In 2005, the patient began to manifest weight gain, hypertension, and facial plethora, but no further evaluations were done. In January 2010, the patient came to our attention and underwent multiple tests that suggested Cushing's disease. A new MRI was negative. Bilateral inferior petrosal sinus sampling showed significant pituitary-to-peripheral ratio and, in May 2010, the patient underwent exploratory pituitary surgery with evidence of a 1-2-mm white-coloured midline area compatible with pituitary adenoma that was surgically removed. Post-operatively, the patient's clinical conditions improved with onset of secondary hypoadrenalism. The histologic examination confirmed a pituitary adenoma (immunostaining was found to be positive for ACTH and negative for prolactin). We report the case of an ACTH-producing microadenoma metachronous to a prolactin secreting microadenoma although not confirmed histologically, shrunk by medical treatment. A review of data in the literature regarding double or multiple pituitary adenomas has also been done. PMID:23325364

  20. Performance of TPC crosstalk correction

    CERN Document Server

    Dydak, F; Krasnoperov, A; Nefedov, Y; Wotschack, J; Zhemchugov, A

    2004-01-01

    The performance of the CERN-Dubna-Milano (CDM) algorithm for TPC crosstalk correction is presented. The algorithm is designed to correct for uni-directional and bi-directional crosstalk, but not for self-crosstalk. It reduces at the 10% level the number of clusters, and the number of pads with a signal above threshold. Despite of dramatic effects in selected channels with complicated crosstalk patterns, the average longitudinal signal shape of a hit, and the average transverse signal shape of a cluster, are little affected by uni-directional and bi-directional crosstalk. The longitudinal signal shape of hits is understood in terms of preamplifier response, longitudinal diffusion, track inclination, and self-crosstalk. The transverse signal shape of clusters is understood in terms of the TPC's pad response function. The CDM crosstalk correction leads to an average charge decrease at the level of 15%, though with significant differences between TPC sectors. On the whole, crosstalk constitutes a relatively benig...

  1. Neu1 sialidase and matrix metalloproteinase-9 cross-talk regulates nucleic acid-induced endosomal TOLL-like receptor-7 and -9 activation, cellular signaling and pro-inflammatory responses.

    Science.gov (United States)

    Abdulkhalek, Samar; Szewczuk, Myron R

    2013-11-01

    The precise mechanism(s) by which intracellular TOLL-like receptors (TLRs) become activated by their ligands remains unclear. Here, we report a molecular organizational G-protein coupled receptor (GPCR) signaling platform to potentiate a novel mammalian neuraminidase-1 (Neu1) and matrix metalloproteinase-9 (MMP-9) cross-talk in alliance with neuromedin B GPCR, all of which form a tripartite complex with TLR-7 and -9. siRNA silencing Neu1, MMP-9 and neuromedin-B GPCR in RAW-blue macrophage cells significantly reduced TLR7 imiquimod- and TLR9 ODN1826-induced NF-κB (NF-κB-pSer(536)) activity. Tamiflu, specific MMP-9 inhibitor, neuromedin B receptor specific antagonist BIM23127, and the selective inhibitor of whole heterotrimeric G-protein complex BIM-46174 significantly block nucleic acid-induced TLR-7 and -9 MyD88 recruitment, NF-κB activation and proinflammatory TNFα and MCP-1 cytokine responses. For the first time, Neu1 clearly plays a central role in mediating nucleic acid-induced intracellular TLR activation, and the interactions involving NMBR-MMP9-Neu1 cross-talk constitute a novel intracellular TLR signaling platform that is essential for NF-κB activation and pro-inflammatory responses. PMID:23827939

  2. Modeling crosstalk in silicon photomultipliers

    Science.gov (United States)

    Gallego, L.; Rosado, J.; Blanco, F.; Arqueros, F.

    2013-05-01

    Optical crosstalk seriously limits the photon-counting resolution of silicon photomultipliers. In this work, realistic analytical models to describe the crosstalk effects on the response of these photodetectors are presented and compared with experimental data. The proposed models are based on the hypothesis that each pixel of the array has a finite number of available neighboring pixels to excite via crosstalk. Dead-time effects and geometrical aspects of the propagation of crosstalk between neighbors are taken into account in the models for different neighborhood configurations. Simple expressions to account for crosstalk effects on the pulse-height spectrum as well as to evaluate the excess noise factor due to crosstalk are also given. Dedicated measurements were carried out under both dark-count conditions and pulsed illumination. Moreover, the influence of afterpulsing on the measured pulse-height spectrum was studied, and a measurement of the recovery time of pixels was reported. High-resolution pulse-height spectra were obtained by means of a detailed waveform analysis, and the results have been used to validate our crosstalk models.

  3. What Are Pituitary Tumors?

    Science.gov (United States)

    ... too little makes you sluggish. If a pituitary tumor makes too much TSH, it can cause hyperthyroidism (an overactive thyroid gland). Adrenocorticotropic hormone (ACTH, also known as corticotropin ) causes ...

  4. Pineal and Pituitary Glands

    Science.gov (United States)

    ... Registries Review Brain & CNS Tumors Signs & Symptoms Anatomy Neurons & Glial Cells Brain Meninges Spinal Cord Cranial Nerves Pineal and Pituitary Glands Abstracting, Coding, & Staging Topographic Sites Histological Types Grading Staging Multiple Primaries Malignant Transformation Coding Sequence ...

  5. Pituitary tumour clonality revisited.

    Science.gov (United States)

    Clayton, R N; Farrell, W E

    2004-01-01

    Allelotype analysis and X chromosome inactivation analysis in women enables the assessment of tissue clonality, and has demonstrated that the majority of sporadic human pituitary adenomas are monoclonal. This implies that these tumours arise from de novo somatic genetic change(s) in a single pituitary cell. However, clonality within any given tumour may be multiple or single, multiple tumours arising on the background of hyperplasia may be of identical or different clonality, multiple 'sporadic' tumours in a tissue may be of differing clonal origin, and finally morphology cannot predict genetic makeup. These general principles may also apply to the pituitary so it is simplistic to assume that monoclonality is inevitable and that pituitary tumours cannot be multiclonal in origin. Indeed, these observations would be entirely compatible with the initiating stimulus resulting in hyperplasia of specific cell subtypes in the pituitary giving rise to a number of different clones each with variable potential to develop into a discrete tumour depending on their rate of cell division/rate of apotosis. Stimuli might include pituitary-specific oncogenes, intrapituitary growth factors, or extrapituitary trophic factors (e.g. hypothalamic releasing hormones). PMID:15281347

  6. Pituitary gland tumors

    International Nuclear Information System (INIS)

    This article gives an overview of the most common tumors of the pituitary gland and the differential diagnostics with special emphasis on radiological diagnostic criteria. A selective search of the literature in PubMed was carried out. Pituitary adenomas constitute 10-15 % of all intracranial tumors and are the most common tumors of the sellar region. Tumors smaller than 1 cm in diameter are called microadenomas while those larger than 1 cm in diameter are called macroadenomas. Approximately 65 % of pituitary gland adenomas secrete hormones whereby approximately 50 % secrete prolactin, 10 % secrete growth hormone (somatotropin) and 6 % secrete corticotropin. Other tumors located in the sella turcica can also cause endocrinological symptoms, such as an oversecretion of pituitary hormone or pituitary insufficiency by impinging on the pituitary gland or its stalk. When tumors spread into the space cranial to the sella turcica, they can impinge on the optic chiasm and cause visual disorders. A common differential diagnosis of a sellar tumor is a craniopharyngeoma. In children up to 10 % of all intracranial tumors are craniopharyngeomas. Other differential diagnoses for sellar tumors are metastases, meningiomas, epidermoids and in rare cases astrocytomas, germinomas or Rathke cleft cysts As these tumors are located in an anatomically complex region of the skull base and are often very small, a highly focused imaging protocol is required. The currently favored modality is magnetic resonance imaging (MRI) with the administration of a contrast agent. The sellar region should be mapped in thin slices. In cases of suspected microadenoma the imaging protocol should also contain a sequence with dynamic contrast administration in order to assess the specific enhancement characteristics of the tumor and the pituitary gland. (orig.)

  7. Pituitary Adenoma Segmentation

    CERN Document Server

    Egger, Jan; Kuhnt, Daniela; Freisleben, Bernd; Nimsky, Christopher

    2011-01-01

    Sellar tumors are approximately 10-15% among all intracranial neoplasms. The most common sellar lesion is the pituitary adenoma. Manual segmentation is a time-consuming process that can be shortened by using adequate algorithms. In this contribution, we present a segmentation method for pituitary adenoma. The method is based on an algorithm we developed recently in previous work where the novel segmentation scheme was successfully used for segmentation of glioblastoma multiforme and provided an average Dice Similarity Coefficient (DSC) of 77%. This scheme is used for automatic adenoma segmentation. In our experimental evaluation, neurosurgeons with strong experiences in the treatment of pituitary adenoma performed manual slice-by-slice segmentation of 10 magnetic resonance imaging (MRI) cases. Afterwards, the segmentations were compared with the segmentation results of the proposed method via the DSC. The average DSC for all data sets was 77.49% +/- 4.52%. Compared with a manual segmentation that took, on the...

  8. [Treatment of pituitary adenomas].

    Science.gov (United States)

    Mezosi, Emese; Nemes, Orsolya

    2009-09-27

    According to epidemiological studies, the prevalence of pituitary adenomas is 16.5% and the majority of them are "incidentalomas". The symptoms of pituitary disorders are often non-specific; disturbances of pituitary function, compression symptoms, hypophysis apoplexy or accidental findings may help the diagnosis. The hormonal evaluation of pituitary adenomas is different from the algorithm used in the disorders of peripheral endocrine organs. The first-line therapy of prolactinomas are the dopamine agonists, and the aims of the treatment are to normalize the prolactin level, restore fertility in child-bearing age, decrease tumor mass, save or improve the residual pituitary function and inhibit the relapse of the disease. The available dopamine agonists in Hungary are bromocriptine and quinagolide. In case of tumors with good therapeutic response, medical therapy can be withdrawn after 3-5 years; hyperprolactinemia will not recur in 2/3 of these patients. Neurosurgery is the primary therapy of GH-, ACTH-, TSH-producing and inactive adenomas. In the last decades, significant improvement has been reached in surgical procedures, resulting in low mortality rates. Acromegalic patients with unresectable tumors have a great benefit from somatostatin analog treatment. The growth hormone receptor antagonist pegvisomant is the newest modality for the treatment of acromegaly. The medical therapy of Cushing's disease is still based on the inhibition of steroid production. A new, promising somatostatin analog, pasireotide is evaluated in clinical trials. The rare TSH-producing tumor can respond to both dopamine agonist and somatostatin analog therapy. The application of conventional radiotherapy has decreased; radiotherapy is mainly used in the treatment of invasive, incurable or malignant tumors. Further studies are needed to elucidate the exact role of radiosurgery and fractionated stereotaxic irradiation in the treatment of pituitary tumors. PMID:19758960

  9. Inflammatory Mechanisms of Organ Crosstalk during Ischemic Acute Kidney Injury

    Directory of Open Access Journals (Sweden)

    Laura E. White

    2012-01-01

    Full Text Available Acute kidney injury (AKI is a common complication during inpatient hospitalization, and clinical outcomes remain poor despite advancements in renal replacement therapy. AKI in the setting of multiple organ failure (MOF remains a formidable challenge to clinicians and incurs an unacceptably high mortality rate. Kidney ischemia-reperfusion injury (IRI incites a proinflammatory cascade and releases cellular and soluble mediators with systemic implications for remote organ injury. Evidence from preclinical models cites mechanisms of organ crosstalk during ischemic AKI including the expression of cellular adhesion molecules, lymphocyte trafficking, release of proinflammatory cytokines and chemokines, and modification of the host innate and adaptive immune response systems. In this paper, the influence of kidney IRI on systemic inflammation and distant organ injury will be examined. Recent experimental data and evolving concepts of organ crosstalk during ischemic AKI will also be discussed in detail.

  10. Expression of Neuropeptide Y in Human Pituitary Adenoma

    Institute of Scientific and Technical Information of China (English)

    Laizhao Chen; Jingjian Ma; Anchao Zheng; Honggang Zheng

    2006-01-01

    and its expression level was related to the types and biological characteristics of the pituitary adenomas. NPY may have a depressive effect on tumor cellular proliferation in pituitary adenomas. NPY possibly participates in modulating angiogenesis and hemodynamic changes in pituitary adenomas.

  11. The effect of proton beam irradiation of the pituitary body on gonadotropic functions in patients with protactinemia

    International Nuclear Information System (INIS)

    Proton therapy efficiency in case of prolactin-secretion pituitary body adenomas and the degree of injury of intact cellular elements - the pituitary body gonadotrophs and thyrotrops - is studied. 16 women with hyperprolactinemy amenorrhee in combination with lacorrhee are investigated. Proton therapy is applied to 13 patients with pituitary body endocellar adenomas. The dose absorbed by pituitary body made up 10 Gy in 10 patiets and in one patient - 120 Gy. Application of functional tests with thyroliberin and luliberin allowed one to reveal the domaging effect of proton therapy on the pituitary body thyrotrophs and gonodotrops. Low therapeutic effect is detected in women with prolactin-secretion adenomas

  12. Pituitary cells in space

    Science.gov (United States)

    Hymer, W. C.; Shellenberger, K.; Grindeland, R.

    1994-01-01

    Cells of the mammalian pituitary gland synthesize and secrete several protein hormones which regulate a number of organ systems throughout the body. These include the musculoskeletal, immune, vascular and endocrine systems. Since changes occur in these tissues as a result of spaceflight, and since pituitary growth hormone (GH) and prolactin (PRL) play a role in the control of these systems on earth, we have focused attention over the last 10 years on GH and PRL cell function during and after spaceflight. The cumulative results of 4 spaceflight missions and several mimicked microgravity experiments establish 1) that production and release of biologically active GH and PRL is repeatedly and significantly attenuated (usually >50%) and 2) that changes in cell morphology also occur. In this paper we describe our results within the framework of methodologies and approaches frequently used to study pituitary cell function on earth. In so doing we hope to develop future flight experiments aimed at uncovering possible microgravity 'sensing systems' within the pituitary cell.

  13. Pituitary: Secretory Tumors

    Science.gov (United States)

    ... is caused by the excess secretion of growth hormone (GH). It can cause noticeable changes in your appearance, ... medication approved for acromegaly. Instead of suppressing excess GH production by the pituitary tumor, it works to stop the hormone from acting on the body, but does not ...

  14. Pituitary irradiation program

    International Nuclear Information System (INIS)

    The alpha particle pituitary irradiation program continues to be a major research project at Donner Pavilion. A study to determine the incidence of hyperprolactinemia in a large series of acromegalic subjects was undertaken. The relationships between plasma levels of growth hormone and prolactin, sellar volume, duration of acromegaly, and age at time of evaluation were investigated

  15. Pituitary aspergillus infection.

    Science.gov (United States)

    Moore, Lauren A; Erstine, Emily M; Prayson, Richard A

    2016-07-01

    Fungal infection should be considered in the differential diagnosis of a pituitary or sellar mass, albeit fungal infections involving the pituitary gland and sella are a rare occurrence. We report a case of Aspergillus infection involving the pituitary gland and sellar region discovered in a 74-year-old man. The patient had a history of hypertension, chronic renal disease, autoimmune hemolytic anemia and presented with right eye pain, headaches and worsening hemiparesis. Imaging studies revealed a right internal carotid artery occlusion and an acute right pontine stroke along with smaller infarcts in the right middle cerebral artery distribution. Clinically, the patient was thought to have vasculitis. An infectious etiology was not identified. He developed respiratory distress and died. At autopsy, necrotizing meningitis was discovered. A predominantly chronic inflammatory cell infiltrate consisting of benign-appearing lymphocytes, plasma cells and macrophages was accompanied by acute angle branching, angioinvasive hyphae which were highlighted on Gomori methenamine silver staining and were morphologically consistent with Aspergillus species. In previously reported cases of Aspergillus infection involving the pituitary or sella, most presented with headaches or impaired vision and were not immunocompromised. A transsphenoidal surgical approach is recommended in suspected cases in order to minimize the risk of dissemination of the infection. Some patients have responded well to antifungal medications once diagnosed. PMID:26896907

  16. Pituitary cells in space

    Science.gov (United States)

    Hymer, W. C.; Shellenberger, K.; Grindeland, R.

    1994-08-01

    Cells of the mammalian pituitary gland synthesize and secrete several protein hormones which regulate a number of organ systems throughout the body. These include the musculoskeletal, immune, vascular and endocrine systems. Since changes occur in these tissues as a result of spaceflight, and since pituitary growth hormone (GH) and prolactin (PRL) play a role in the control of these systems on earth, we have focused attention over the last 10 years on GH and PRL cell function during and after spaceflight. The cumulative results of 4 spaceflight missions and several mimicked microgravity (μG) experiments establish 1) that production and release of biologically active GH and PRL is repeatedly and significantly attenuated (usually > 50%) and 2) that changes in cell morphology also occur. In this paper we describe our results within the framework of methodologies and approaches frequently used to study pituitary cell function on earth. In so doing we hope to develop future flight experiments aimed at uncovering possible μG ``sensing systems'' within the pituitary cell.

  17. Molecular Mechanisms Underlying Pituitary Pathogenesis.

    Science.gov (United States)

    Sapochnik, Melanie; Nieto, Leandro Eduardo; Fuertes, Mariana; Arzt, Eduardo

    2016-04-01

    During the last years, progress has been made on the identification of mechanisms involved in anterior pituitary cell transformation and tumorigenesis. Oncogene activation, tumor suppressor gene inactivation, epigenetic changes, and microRNAs deregulation contribute to the initiation of pituitary tumors. Despite the high prevalence of pituitary adenomas, they are mostly benign, indicating that intrinsic mechanisms may regulate pituitary cell expansion. Senescence is characterized by an irreversible cell cycle arrest and represents an important protective mechanism against malignancy. Pituitary tumor transforming gene (PTTG) is an oncogene involved in early stages of pituitary tumor development, and also triggers a senescence response by activating DNA-damage signaling pathway. Cytokines, as well as many other factors, play an important role in pituitary physiology, affecting not only cell proliferation but also hormone secretion. Special interest is focused on interleukin-6 (IL-6) because its dual function of stimulating pituitary tumor cell growth but inhibiting normal pituitary cells proliferation. It has been demonstrated that IL-6 has a key role in promoting and maintenance of the senescence program in tumors. Senescence, triggered by PTTG activation and mediated by IL-6, may be a mechanism for explaining the benign nature of pituitary tumors. PMID:26718581

  18. Non-pituitary origin sellar tumours mimicking pituitary macroadenomas

    Energy Technology Data Exchange (ETDEWEB)

    Abele, T.A., E-mail: travaus@gmail.com [University of Texas Southwestern Medical Center at Dallas, Dallas, TX (United States); Yetkin, Z.F.; Raisanen, J.M.; Mickey, B.E.; Mendelsohn, D.B. [University of Texas Southwestern Medical Center at Dallas, Dallas, TX (United States)

    2012-08-15

    Although the large majority of sellar tumours are pituitary adenomas, several other pituitary and non-pituitary origin tumours arise in the sellar and parasellar regions. Given their location, non-adenomatous lesions frequently mimic pituitary macroadenomas and can pose a diagnostic challenge for the radiologist. Distinguishing rare sellar lesions from the common macroadenoma helps to direct the correct surgical approach and reduce the risk of incomplete resection and/or complications such as cerebrospinal fluid leak with the potential for meningitis. The purpose of this article is to review the imaging features of non-pituitary-origin sellar tumours, focusing on characteristics that may distinguish them from pituitary macroadenomas. Lesions include meningioma, metastatic disease, epidermoid cyst, germinoma, chondrosarcoma, giant cell tumour, and giant aneurysm.

  19. Haemorrhagic pituitary tumours

    International Nuclear Information System (INIS)

    In a group of 69 patients with pituitary tumours, 12 were found to have evidence of intratumoral haemorrhage on MRI, characterized by high signal intensity on short TR/TE sequences. This was verified in all but 1 patient. The majority of the bleedings occurred in macroadenomas. Five (42%) were prolactinomas and 4 (33%) were non-functioning adenomas. There were 2 GH- and 1 ACTH-secreting tumours. All 5 patients with prolactinomas were on bromocriptine medication. Two of the patients had a clinical picture of pituitary apoplexy. The haemorrhage was not large enough to prompt surgery in any of the patients. However, surgical verification of the diagnosis was obtained in 5 cases, while 6 patients were examined with follow-up MRI. (orig.)

  20. Pituitary stalk tuberculoma.

    Science.gov (United States)

    Stalldecker, Graciela; Diez, Sabrina; Carabelli, Alejandra; Reynoso, Roxana; Rey, Raul; Hofmann, Nestor; Beresñak, Alejandro

    2002-01-01

    Pituitary tuberculomas are exceptionally rare. Even with no evidence of systemic tuberculosis, it is important to recognize these lesions in the differential diagnosis of the intrasuprasellar tumors because they are curable. At present, in developed countries the frequency of intracranial tuberculomas of nervous system tumors is around 0.5-4%, whereas in under developed countries is 15-30%. It mainly affects children and young adults. In some cases, an accurate diagnosis may lead to an efficient medical therapy on the basis of biological, hormonal and imaging scans examinations. The case we studied shows the difficulties encountered in the diagnosis of a thickened stalk having normal pituitary image. It is to be highlighted the usage of the Polymerase Chain Reaction (PCR) technique. PMID:12812306

  1. Hypothalamus, pituitary and thyroid

    International Nuclear Information System (INIS)

    An investigation has been carried out due to the apparent disagreement between the very wide so called normal ranges of the serum levels of the thyroid hormones and the extreme sensitivity of the hypothalamus-pituitary control system to minimal changes in thyroid hormone production. TRH (thyrotropin-releasing-hormone) infusion and injection studies have been performed using labelled compounds and radioassays and radioimmunoassays. (Auth.)

  2. Pituitary gland tumors; Hypophysentumoren

    Energy Technology Data Exchange (ETDEWEB)

    Jesser, J.; Schlamp, K.; Bendszus, M. [Radiologische Klinik, Universitaetsklinikum Heidelberg, Abteilung fuer Neuroradiologie, Heidelberg (Germany)

    2014-10-15

    This article gives an overview of the most common tumors of the pituitary gland and the differential diagnostics with special emphasis on radiological diagnostic criteria. A selective search of the literature in PubMed was carried out. Pituitary adenomas constitute 10-15 % of all intracranial tumors and are the most common tumors of the sellar region. Tumors smaller than 1 cm in diameter are called microadenomas while those larger than 1 cm in diameter are called macroadenomas. Approximately 65 % of pituitary gland adenomas secrete hormones whereby approximately 50 % secrete prolactin, 10 % secrete growth hormone (somatotropin) and 6 % secrete corticotropin. Other tumors located in the sella turcica can also cause endocrinological symptoms, such as an oversecretion of pituitary hormone or pituitary insufficiency by impinging on the pituitary gland or its stalk. When tumors spread into the space cranial to the sella turcica, they can impinge on the optic chiasm and cause visual disorders. A common differential diagnosis of a sellar tumor is a craniopharyngeoma. In children up to 10 % of all intracranial tumors are craniopharyngeomas. Other differential diagnoses for sellar tumors are metastases, meningiomas, epidermoids and in rare cases astrocytomas, germinomas or Rathke cleft cysts As these tumors are located in an anatomically complex region of the skull base and are often very small, a highly focused imaging protocol is required. The currently favored modality is magnetic resonance imaging (MRI) with the administration of a contrast agent. The sellar region should be mapped in thin slices. In cases of suspected microadenoma the imaging protocol should also contain a sequence with dynamic contrast administration in order to assess the specific enhancement characteristics of the tumor and the pituitary gland. (orig.) [German] Diese Arbeit ist eine Uebersicht ueber die haeufigsten Hypophysentumoren und deren Differenzialdiagnosen mit Augenmerk auf die

  3. Post-polymerization crosstalk between the actin cytoskeleton and microtubule network.

    Science.gov (United States)

    Joo, E Emily; Yamada, Kenneth M

    2016-05-01

    Cellular cytoskeletal systems play many pivotal roles in living organisms by controlling cell shape, division, and migration, which ultimately govern morphology, physiology, and functions of animals. Although the cytoskeletal systems are distinct and play different roles, there is growing evidence that these diverse cytoskeletal systems coordinate their functions with each other. This coordination between cytoskeletal systems, often termed cytoskeletal crosstalk, has been identified when the dynamic state of one individual system affects the other system. In this review, we briefly describe some well-established examples of crosstalk between cytoskeletal systems and then introduce a newly discovered form of crosstalk between the actin cytoskeleton and microtubule network that does not appear to directly alter polymerization or depolymerization of either system. The biological impact and possible significance of this post-polymerization crosstalk between actin and microtubules will be discussed in detail. PMID:27058810

  4. Genetics Home Reference: combined pituitary hormone deficiency

    Science.gov (United States)

    ... Genetics Home Health Conditions combined pituitary hormone deficiency combined pituitary hormone deficiency Enable Javascript to view the ... boxes. Print All Open All Close All Description Combined pituitary hormone deficiency is a condition that causes ...

  5. Cellular toxicity (High-Throughput Cellular Assays for Modeling Toxicity in the Fish Reproductive System)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this project is to adapt cellular in vitro assay systems of the rainbow trout pituitary, liver and ovary for high-throughput screening (HTS) of...

  6. PI3K signalling in GnRH actions on dispersed goldfish pituitary cells: relationship with PKC-mediated LH and GH release and regulation of long-term effects on secretion and total cellular hormone availability.

    Science.gov (United States)

    Pemberton, Joshua G; Orr, Michael E; Stafford, James L; Chang, John P

    2014-09-01

    Goldfish pituitary cells are exposed to two GnRHs, salmon (s)GnRH and chicken (c)GnRH-II. Phosphoinositide 3-kinase (PI3K) and protein kinase C (PKC) both participate in acute sGnRH- and cGnRH-II-stimulated LH and GH release. Using goldfish pituitary cells, we examined the relationship between PI3K and PKC in acute LH and GH secretion, and PI3K involvement in chronic hormone release and total LH and GH availability. The PI3K inhibitor LY294002 did not affect PKC agonists-induced LH or GH release, and PKC agonists did not alter PI3K p85 phosphorylation, suggesting PKC activation is not upstream of PI3K in acute hormone release. In 2, 6, 12 and 24h treatments, LY294002 did not affect LH release but stimulated total LH availability at 6h. sGnRH stimulatory actions on LH release and total availability at 12 and 24h, and cGnRH-II effects on these parameters at 6h were inhibited by LY294002. LY294002 enhanced basal GH release at 2 and 6h, but reduced total GH at 12 and 24h. Increased GH release was seen following 6, 12 and 24h of sGnRH, and 2, 6 and 24h of cGnRH-II treatment but total GH availability was only elevated by 24h cGnRH-II treatment. Whereas LY294002 inhibited GH release responses to sGnRH at 12h and cGnRH-II at 6h, it attenuated cGnRH-II-elicited, but not sGnRH-induced, effects on total GH. These results indicate that PI3K differentially modulates long-term basal and GnRH-stimulated hormone release, and total hormone availability, in a time-, cell-type-, and GnRH isoform-selective manner. PMID:24681225

  7. Modeling crosstalk and afterpulsing in silicon photomultipliers

    OpenAIRE

    Rosado Vélez, Jaime; Aranda, V. M.(Universidad Complutense de Madrid, Madrid, Spain); Blanco Ramos, Francisco; Arqueros Martínez, Fernando

    2014-01-01

    An experimental method to characterize the crosstalk and afterpulsing in silicon photomultipliers has been developed and applied to two detectors fabricated by Hamamatsu. An analytical model of optical crosstalk that we presented in a previous publication has been compared with new measurements, confirming our results. Progresses on a statistical model to describe afterpulsing and delayed crosstalk are also shown and compared with preliminary experimental data. (C) 2014 Elsevier B.V. All righ...

  8. Modeling crosstalk and afterpulsing in silicon photomultipliers

    CERN Document Server

    Rosado, Jaime; Blanco, Francisco; Arqueros, Fernando

    2014-01-01

    An experimental method to characterize the crosstalk and afterpulsing in silicon photomultipliers has been developed and applied to two detectors fabricated by Hamamatsu. An analytical model of optical crosstalk that we presented in a previous publication has been compared with new measurements, confirming our results. Progresses on a statistical model to describe afterpulsing and delayed crosstalk are also shown and compared with preliminary experimental data.

  9. Modeling crosstalk and afterpulsing in silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Rosado, J., E-mail: jaime_ros@fis.ucm.es; Aranda, V.M.; Blanco, F.; Arqueros, F.

    2015-07-01

    An experimental method to characterize the crosstalk and afterpulsing in silicon photomultipliers has been developed and applied to two detectors fabricated by Hamamatsu. An analytical model of optical crosstalk that we presented in a previous publication has been compared with new measurements, confirming our results. Progresses on a statistical model to describe afterpulsing and delayed crosstalk are also shown and compared with preliminary experimental data.

  10. Notch-EGFR/HER2 Bidirectional Crosstalk in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Andrew T Baker

    2014-12-01

    Full Text Available The Notch pathway is a well-established mediator of cell-cell communication that plays a critical role in stem cell survival, self-renewal, cell fate decisions, tumorigenesis, invasion, metastasis, and drug resistance in a variety of cancers. An interesting form of crosstalk exists between the Notch receptor and the Epidermal Growth Factor Receptor Tyrosine Kinase family which consists of HER-1, -2, -3, and -4. Overexpression of HER and/or Notch occurs in several human cancers including brain, lung, breast, ovary, and skin making them potent oncogenes capable of advancing malignant disease. Continued assessment of interplay between these two critical signaling networks uncovers new insight into mechanisms used by HER-driven cancer cells to exploit Notch as a compensatory pathway. The compensatory Notch pathway maintains HER-induced downstream signals transmitted to pathways such as Mitogen Activated Protein Kinase (MAPK and Phosphatidylinositol 3-Kinase (PI3K, thereby allowing cancer cells to survive molecular targeted therapies, undergo EMT, and increase cellular invasion. Uncovering the critical crosstalk between the HER and Notch pathways can lead to improved screening for the expression of these oncogenes enabling patients to optimize their personal treatment options and predict potential treatment resistance. This review will focus on the current state of crosstalk between the HER and Notch receptors and the effectiveness of current therapies targeting HER-driven cancers.

  11. MRI of cystic pituitary tumors

    International Nuclear Information System (INIS)

    We retrospectively reviewed MRI findings of 17 patients with 3 histologically proven cystic pituitary tumors. They consisted of 10 cystic pituitary adenomas, 4 craniopharyngiomas and 3 Rathke's cleft cysts. We analyzed the following MRI parameters such as cyst wall appearance, enhancement pattern of cyst wall, location of residual pituitary gland and location of tumor. They were clinically significant parameters for histological differentiation. Even though combinations of such MRI parameters helped for more accurate preoperative diagnosis, the differentiation between craniopharyngioma and Rathke's cleft cyst was difficult in some cases. (author)

  12. Endoscopic pituitary surgery.

    Science.gov (United States)

    Cappabianca, Paolo; Cavallo, Luigi Maria; de Divitiis, Oreste; Solari, Domenico; Esposito, Felice; Colao, Annamaria

    2008-01-01

    Pituitary surgery is a continuous evolving speciality of the neurosurgeons' armamentarium, which requires precise anatomical knowledge, technical skills and integrated appreciation of the pituitary pathophysiology. What we consider "pure" endoscopic transsphenoidal surgery is a procedure performed through the nose and the sphenoid bone, with the endoscope alone throughout the whole approach to visualize the surgical target area and without the use of any transsphenoidal retractor. It offers some advantages due to the endoscope itself: a superior close-up view of the relevant anatomy and an enlarged working angle are provided with an increased panoramic vision inside the surgical area. Concerning results in terms of mass removal, relief of clinical symptoms, cure of the underlying disease and complication rate, they are, at least, similar to those reported in the major microsurgical series, but patient compliance is by far better. Furthermore transsphenoidal endoscopy brings advantages to the patient (less nasal traumatism, no nasal packing, less post-op pain and usually quick recovery), to the surgeon (wider and closer view of the surgical target area, increase of the scientific activity as from the peer-reviewed literature on the topic in the last 10 years, smoothing of interdisciplinary cooperation), to the institution (shorter post-op hospital stay, increase of the case load). Besides, further progress and technological advance are expected from the close cooperation between different technologies and industries. Continuing works in such field of "minimalism" will offer further possibilities to provide the surgeon with even more effectiveness and safety, and, on the other hand, the patient with improvement of results. PMID:18286374

  13. Hypothalamic-pituitary functions in patients with idiopathic pituitary dwarfism.

    Science.gov (United States)

    Demura, R; Jujo, K; Takano, K; Odagiri, E; Maeda, T; Suda, T; Demura, H; Shizume, K

    1975-04-01

    To investigate hypothalamic-pituitary functions and the primary site of the lesion in idiopathic pituitary dwarfism, various pituitary function tests, especially the pituitary hormone responses to the hypophysiotropic hormones were studied in 23 patients with idiopathic pituitary dwarfism. A few cases showed slight responses of GH to GH stimulation tests. Gonadotropin deficiencies were most frequently noted among pituitary hormones. The basal levels and the responses of plasma LH and FSH to LH-RH test were diminished markedly in all of the cases except in 5 cases with isolated GH deficiency. Responses of LH and FSH to LH-RH improved markedly after a long term administration of LH-RH for a period of one month in 2 patients with gonadotropin deficiency. As to TSH axis, half of the cases accompanied hypothyroidism. However, the responses of TSH to TRH were normal in all of the cases regardless of the thyroid function. The basal levels and the responses of plasma cortisol and 11-deoxycortisol to the rapid metopirone test were also impaired in about half of the cases. Basal levels of plasma prolactin were normal in all of the cases and the responses of prolactin to TRH were normal in cases with normal thyroid function, but slightly delayed in cases with hypothyroidism. It is concluded from the above observations that the incidences of various pituitary hormone deficiencies were quite high in this disorder and hypophysiotropic hormone deficiencies may cause pituitary hormone deficiencies. Therefore, it is suggested that the primary site of the lesion in this disorder might be at the hypothalamus. PMID:807471

  14. Experimental study of interband and intraband crosstalk in WDM networks

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The impacts of interband and intraband crosstalk are studied and compared experimentally. Results show that interband crosstalk can be removed with narrow-band filters and has no influence on signal. Intraband crosstalk will result in signal eye diagram close and BER increasing. When the polarization states of signal and crosstalk align, intraband crosstalk seriously decreases signal quality. But when they misalign, it has little influence. Coherent and incoherent crosstalk are studied experimentally. Results show that coherent crosstalk is less harmful to system performance than incoherent crosstalk.

  15. Cross-Talk between Signaling Pathways Can Generate Robust Oscillations in Calcium and cAMP

    OpenAIRE

    Siso-Nadal, Fernando; Fox, Jeffrey J.; Laporte, Stéphane A.; Hébert, Terence E.; Swain, Peter S

    2009-01-01

    Background To control and manipulate cellular signaling, we need to understand cellular strategies for information transfer, integration, and decision-making. A key feature of signal transduction is the generation of only a few intracellular messengers by many extracellular stimuli. Methodology/Principal Findings Here we model molecular cross-talk between two classic second messengers, cyclic AMP (cAMP) and calcium, and show that the dynamical complexity of the response of both messengers inc...

  16. Intrasellar schwannoma mimicking pituitary adenoma

    OpenAIRE

    Sai Sudarsan Puduru

    2013-01-01

    Intrasellar location of schwannoma is extremely uncommon and 18 cases are documented in the literature till now. This report describes intrasellar schwannoma in a patient in whom the neuroimaging features were suggestive of a pituitary adenoma.

  17. Signaling pathway networks mined from human pituitary adenoma proteomics data

    Directory of Open Access Journals (Sweden)

    Zhan Xianquan

    2010-04-01

    pituitary control related to gene expression and cellular development, and no canonical toxicity pathways were identified. Conclusions This pathway network analysis demonstrated that mitochondrial dysfunction, oxidative stress, cell-cycle dysregulation, and the MAPK-signaling abnormality are significantly associated with a pituitary adenoma. These pathway-network data provide new insights into the molecular mechanisms of human pituitary adenoma pathogenesis, and new clues for an in-depth investigation of pituitary adenoma and biomarker discovery.

  18. Recent advances in pituitary research

    International Nuclear Information System (INIS)

    The aims of this study are to investigate the neuroendocrine, neuroanatomical, and other effects of irradiation on defined regions of the pituitary and to correlate the onset of specific hormonal changes with anatomical localization of the focal lesions as well as with dose and mode of heavy-ion delivery. Autopsy data from these experiments will be used in the development of a methodology for total pituitary destruction without producing localized or widespread radionecrosis of surrounding tissues

  19. Recent advances in pituitary research

    International Nuclear Information System (INIS)

    The aim of the present study is to investigate the effects of irradiation on defined regions of the pituitary with 12C from the Bevalac. From initial experiments using 250 MeV/amu carbon ions and with use of sensitive radioimmunoassay hormone measurements, effects on the in vivo secretion of the pituitary peptide hormones by high LET carbon ions have been demonstrated. A greater and more rapid hormonal ablative effect was observed for Lateral Bragg Peak (LBP) with combined peak doses of approximately 14,000 rad in the lateral margins of the pituitary than when either higher central doses (CBP) or lower spread peak doses (SBP) were employed. The in vivo differences observed at 38 days suggest that both dose and volume of irradiated tissues determine the magnitude of the effect on hormone secretion. The greater hormonal effect of Bragg peak lesions in the lateral lobes of the pituitary conforms to other anatomical data and confirms that spatial distribution of cells in the pituitary can be used as an in vivo means of confirming accurate localization of high LET irradiation in the pituitary

  20. Radiosurgery of pituitary adenomas

    International Nuclear Information System (INIS)

    The efficacy and role of gamma knife (GK) in the treatment of various pituitary adenomas are described on author's experience and discussed with literature. GK subjects are 328 patients (M 126/F 202, av. age of 47.8 y) in author's hospital, and satisfactory follow-up (32-44 mo) for evaluation has been possible in 253 cases, who had tumors non-functional (129 cases), producing ACTH (23), HGH (70) and PRL (31). Stereotactic GK radiosurgery is done with navigation by Gamma Plan based on enhanced MRI images at various doses, and evaluation in the follow-up period is performed by hormonal levels and MRI which give efficacy of complete response (CR), partial response (PR), MR and standard deviation (SD)/ progressive disease (PD) on the tumor size. The overall tumor control rate is found to be 95-100%. Effectiveness (CR and PR) is found as high as 77.4% in PRL-producing tumor (marginal dose 14-32 Gy), 65% in non-functioning (15-25 Gy), 61% in ACTH (19-30 Gy) and 60% in GH (19-31 Gy), of which tendency is similar to that in literature. Even in ACTH-producing tumor, low ACTH and cortisol levels persisted with tendency of improved obese and hypertensive symptoms. GK radiosurgery has limitations in the tissue size and distance between the tumor and optic nerve/chiasm, but for the enough small tumor, it gives satisfactorily long term efficacy. (R.T.)

  1. Infrared focal plane array crosstalk measurement

    Science.gov (United States)

    Dang, Khoa V.; Kauffman, Christopher L.; Derzko, Zenon I.

    1992-07-01

    Crosstalk between two neighboring elements in a focal plane array (FPA) occurs when signal incident on one element in the array is seen on another. This undesired effect can occur due to both the electrical and optical properties of the FPA. An effort is underway at the U.S. Army's Night Vision and Electro-Optics Directorate to develop a capability to measure crosstalk on both mid-wave infrared and long-wave infrared FPAs. A single detector in an array is illuminated using a laser source coupled with a beam expander, collimating lens, and focusing lens. The relative response of that detector to that of its neighboring detectors is measured to calculate crosstalk. The various components of the test station, the methodology for implementing the crosstalk measurement, and a model of the laser spot size are discussed.

  2. Bone-cartilage interface crosstalk in osteoarthritis: potential pathways and future therapeutic strategies.

    Science.gov (United States)

    Yuan, X L; Meng, H Y; Wang, Y C; Peng, J; Guo, Q Y; Wang, A Y; Lu, S B

    2014-08-01

    Currently, osteoarthritis (OA) is considered a disease of the entire joint, which is not simply a process of wear and tear but rather abnormal remodelling and joint failure of an organ. The bone-cartilage interface is therefore a functioning synergistic unit, with a close physical association between subchondral bone and cartilage suggesting the existence of biochemical and molecular crosstalk across the OA interface. The crosstalk at the bone-cartilage interface may be elevated in OA in vivo and in vitro. Increased vascularisation and formation of microcracks associated with abnormal bone remodelling in joints during OA facilitate molecular transport from cartilage to bone and vice versa. Recent reports suggest that several critical signalling pathways and biological factors are key regulators and activate cellular and molecular processes in crosstalk among joint compartments. Therapeutic interventions including angiogenesis inhibitors, agonists/antagonists of molecules and drugs targeting bone remodelling are potential candidates for this interaction. This review summarised the premise for the presence of crosstalk in bone-cartilage interface as well as the current knowledge of the major signalling pathways and molecular interactions that regulate OA progression. A better understanding of crosstalk in bone-cartilage interface may lead to development of more effective strategies for treating OA patients. PMID:24928319

  3. Crosstalk analysis of carbon nanotube bundle interconnects

    OpenAIRE

    Zhang, Kailiang; Tian, Bo; Zhu, Xiaosong; WANG, FANG; Wei, Jun

    2012-01-01

    Carbon nanotube (CNT) has been considered as an ideal interconnect material for replacing copper for future nanoscale IC technology due to its outstanding current carrying capability, thermal conductivity, and mechanical robustness. In this paper, crosstalk problems for single-walled carbon nanotube (SWCNT) bundle interconnects are investigated; the interconnect parameters for SWCNT bundle are calculated first, and then the equivalent circuit has been developed to perform the crosstalk analys...

  4. Gallium-based avalanche photodiode optical crosstalk

    Science.gov (United States)

    Blazej, Josef; Prochazka, Ivan; Hamal, Karel; Sopko, Bruno; Chren, Dominik

    2006-11-01

    Solid-state single photon detectors based on avalanche photodiode are getting more attention in various areas of applied physics: optical sensors, quantum key distribution, optical ranging and Lidar, time-resolved spectroscopy, X-ray laser diagnostics, and turbid media imaging. Avalanche photodiodes specifically designed for single photon counting semiconductor avalanche structures have been developed on the basis of various materials: Si, Ge, GaP, GaAsP, and InGaP/InGaAs at the Czech Technical University in Prague during the last 20 years. They have been tailored for numerous applications. Trends in demand are focused on detection array construction recently. Even extremely small arrays containing a few cells are of great importance for users. Electrical crosstalk between individual gating and quenching circuits and optical crosstalk between individual detecting cells are serious limitation for array design and performance. Optical crosstalk is caused by the parasitic light emission of the avalanche which accompanies the photon detection process. We have studied in detail the optical emission of the avalanche photon counting structure in the silicon- and gallium-based photodiodes. The timing properties and spectral distribution of the emitted light have been measured for different operating conditions to quantify optical crosstalk. We conclude that optical crosstalk is an inherent property of avalanche photodiode operated in Geiger mode. The only way to minimize optical crosstalk in avalanche photodiode array is to build active quenching circuit with minimum response time.

  5. Genetically engineered mouse models of pituitary tumors

    OpenAIRE

    DavidACano; AlfonsoSoto-Moreno

    2014-01-01

    Animal models constitute valuable tools for investigating the pathogenesis of cancer as well as for preclinical testing of novel therapeutics approaches. However, the pathogenic mechanisms of pituitary tumor formation remain poorly understood, particularly in sporadic adenomas, thus making it a challenge to model pituitary tumors in mice. Nevertheless, genetically engineered mouse models (GEMMs) of pituitary tumors have provided important insight into pituitary tumor biology. In this paper, w...

  6. Subarachnoid hemorrhage in pituitary tumor

    Directory of Open Access Journals (Sweden)

    Ashis Patnaik

    2013-01-01

    Full Text Available Subarachnoid hemorrhage (SAH is the bleeding into the subarachnoid space containing cerebrospinal fluid. The most common cause of SAH is trauma. Rupture of aneurysms, vascular anomalies, tumor bleeds and hypertension are other important etiologies. SAH in the setting of pituitary tumor can result from various causes. It can be due to intrinsic tumor related pathology, injury to surrounding the vessel during the operative procedure or due to an associated aneurysm. We discuss the pathological mechanisms and review relevant literature related to this interesting phenomenon. Early and accurate diagnosis of the cause of the SAH in pituitary tumors is important, as this influences the management.

  7. Imaging of giant pituitary adenomas

    International Nuclear Information System (INIS)

    We present five proven giant pituitary adenomas studied by CT and MRI, and review the clinical and imaging findings. Our aim was to examine the radiologic appearances and to search for criteria useful in distinguishing these tumors from other sellar and suprasellar tumours, mainly craniopharyngioma. The main differences from small adenomas were high prevalence of macrocysts, a more invasive behaviour and a clinical picture dominated by mass effect rather than endocrine disturbance. Factors supporting the diagnosis of pituitary adenoma in a giant intra- and suprasellar mass include: infrasellar extension, absence of calcification and presence of low-signal cysts on T1-weighted images. (orig.) (orig.)

  8. Pituitary tumors: Diagnosis by magnetic resonance imaging

    International Nuclear Information System (INIS)

    This paper presents a survey of the current status of the diagnosis of pituitary tumors by means of magnetic resonance imaging. It focuses on the clinical and practical aspects. The recommended procedure and the sequences and slice orientations for magnetic resonance imaging of the pituitary gland are presented, and the features that are essential for the diagnosis of pituitary tumors are discussed. (orig.)

  9. The Spectrum of Pituitary Adenoma Hemorrhage

    OpenAIRE

    Hickstein, Dennis D.; Marshall, John C.; Chandler, William F.

    1986-01-01

    In 34 cases of pituitary adenoma hemorrhage at one institution, the clinical manifestations of adenoma hemorrhage depended upon the size of the adenoma, the presence of suprasellar extension, the amount of hemorrhage and the extent of pituitary glandular destruction. Recognition of the spectrum of acute, subacute and chronic pituitary adenoma hemorrhage should expedite diagnosis and treatment.

  10. Cross-talk between signaling pathways can generate robust oscillations in calcium and cAMP.

    Directory of Open Access Journals (Sweden)

    Fernando Siso-Nadal

    Full Text Available BACKGROUND: To control and manipulate cellular signaling, we need to understand cellular strategies for information transfer, integration, and decision-making. A key feature of signal transduction is the generation of only a few intracellular messengers by many extracellular stimuli. METHODOLOGY/PRINCIPAL FINDINGS: Here we model molecular cross-talk between two classic second messengers, cyclic AMP (cAMP and calcium, and show that the dynamical complexity of the response of both messengers increases substantially through their interaction. In our model of a non-excitable cell, both cAMP and calcium concentrations can oscillate. If mutually inhibitory, cross-talk between the two second messengers can increase the range of agonist concentrations for which oscillations occur. If mutually activating, cross-talk decreases the oscillation range, but can generate 'bursting' oscillations of calcium and may enable better filtering of noise. CONCLUSION: We postulate that this increased dynamical complexity allows the cell to encode more information, particularly if both second messengers encode signals. In their native environments, it is unlikely that cells are exposed to one stimulus at a time, and cross-talk may help generate sufficiently complex responses to allow the cell to discriminate between different combinations and concentrations of extracellular agonists.

  11. Computationally Efficient Partial Crosstalk Cancellation in Fast Time-Varying DSL Crosstalk Environments

    Directory of Open Access Journals (Sweden)

    Forouzan Amir R

    2007-01-01

    Full Text Available Line selection (LS, tone selection (TS, and joint tone-line selection (JTLS partial crosstalk cancellers have been proposed to reduce the online computational complexity of far-end crosstalk (FEXT cancellers in digital subscriber lines (DSL. However, when the crosstalk profile changes rapidly over time, there is an additional requirement that the partial crosstalk cancellers, particularly the LS and JTLS schemes, should also provide a low preprocessing complexity. This is in contrast to the case for perfect crosstalk cancellers. In this paper, we propose two novel channel matrix inversion methods, the approximate inverse (AI and reduced inverse (RI schemes, which reduce the recurrent complexity of the LS and JTLS schemes. Moreover, we propose two new classes of JTLS algorithms, the subsort and Lagrange JTLS algorithms, with significantly lower computational complexity than the recently proposed optimal greedy JTLS scheme. The computational complexity analysis of our algorithms shows that they provide much lower recurrent complexities than the greedy JTLS algorithm, allowing them to work efficiently in very fast time-varying crosstalk environments. Moreover, the analytical and simulation results demonstrate that our techniques are close to the optimal solution from the crosstalk cancellation point of view. The results also reveal that partial crosstalk cancellation is more beneficial in upstream DSL, particularly for short loops.

  12. Genetically engineered mouse models of pituitary tumors

    Directory of Open Access Journals (Sweden)

    DavidACano

    2014-08-01

    Full Text Available Animal models constitute valuable tools for investigating the pathogenesis of cancer as well as for preclinical testing of novel therapeutics approaches. However, the pathogenic mechanisms of pituitary tumor formation remain poorly understood, particularly in sporadic adenomas, thus making it a challenge to model pituitary tumors in mice. Nevertheless, genetically engineered mouse models (GEMMs of pituitary tumors have provided important insight into pituitary tumor biology. In this paper, we review various GEMMs of pituitary tumors, highlighting their contributions and limitations, and discuss opportunities for research in the field.

  13. DIAGNOSIS AND TREATMENT OF THE PITUITARY METASTASES

    Institute of Scientific and Technical Information of China (English)

    连伟; 任祖渊; 苏长保

    2004-01-01

    Thee cases of pituitary metastases were reported. They all had operations and the pathological examination confirming the diagnosis. The clinical features of diabetes insipidus and extraocular nerve palsy were presented. In two cases, the original tumors were bronchioloalveolar carcinoma; in the other one, the original tumor was unknown. All three cases had poor outcome. These cases illustrate the fact that a pituitary metastasis can closely mimic a pituitary benign tumor, such as pituitary adenoma. Especially in the presence of suggestive symptoms such as diabetes insipidus and/or cranical nerve paralysis, the possibility of metastatic disease in the differential diagnosis of a pituitary mass should always be considered.

  14. MR imaging of hemorrhagic pituitary apoplexy

    International Nuclear Information System (INIS)

    Pituitary apoplexy (stroke) may be ischemic or hemorrhagic. The authors studied three patients with hemorrhagic pituitary apoplexy. MR imaging is an accurate and noninvasive method that easily identifies areas of pituitary hemorrhage more than 48 hours old. Surgical planning based on MR imaging findings has been less successful than diagnosis based on MR imaging. In two patients a subfrontal approach was chosen because MR imaging suggested suprasellar extension, although none was found at operation. They hypothesize that pituitary hemmorrhage may act as a mass, creating alterations in cerebrospinal fluid or blood flow in the pituitary stalk and hypothamlamus that may exaggerate the suprasellar extension

  15. Computed tomography in pituitary abscess

    Energy Technology Data Exchange (ETDEWEB)

    Appel, W.; Scharphuis, T.; Distelmaier, P.

    1986-06-01

    This is a report on a rare case of a recurring abscess in the pituitary gland. Diagnosis was extremely difficult to establish preoperatively. This is demonstrated via various radiological methods. Anamnesis and clinical disease pattern are important assisting factors in diagnosis.

  16. Pituitary cretinism in two sisters.

    OpenAIRE

    Kohno, H.; Watanabe, N.; Ootsuka, M; Kajiwara, M; Gohya, N

    1980-01-01

    Two sisters with cretinism are reported. Each showed low levels of serum triiodothyronine, thyroxine, and thyroid-stimulating hormone (TSH). In the elder sister, serum TSH did not increase after administration of thyrotropin-releasing hormone. We conclude that cretinism in these 2 sisters was due to TSH deficiency. This is the second report of 'familial' pituitary cretinism (TSH-deficient congenital hypothyroidism).

  17. CT evaluation of the normal pituitary gland

    International Nuclear Information System (INIS)

    Direct coronal computed tomography with 1.5mm contiguous scanning was done in total 95 cases, who had no clinical evidence of pituitary and hypothalamic disease. The evaluation of pituitary height, width, upper surface contour and density was done and the pituitary stalk was also evaluated. The results as follow : 1. Total 95 cases were 45 males and 50 females. 2. The average height of normal pituitary gland was 5.72 ± 1.44 mm in female and 5.37 ± 1.17 mm in male. There was no significant difference of pituitary height between male and female (ρ > 0.1). 3. The pituitary height was decreased according to the increased age both in male and female except prepubertal age. 4. The group between 15-30 year old age showed significantly increased pituitary height comparing to the remained age group both in male and female (ρ 0.1). 8. The focal low density of normal pituitary gland was noted in only 8.4% and its size was always below 3mm. 9. The pituitary stalk can be seen in 94.7% by direct coronal CT scanning and it was located at the midline. The width of pituitary stalk was always smaller than internal carotid artery and basilar artery. 10. There were no significant difference in pituitary height and width according to the menopause or the marriage

  18. Cross-talk between calcium and reactive oxygen species signaling

    Institute of Scientific and Technical Information of China (English)

    Yuan YAN; Chao-liang WEI; Wan-rui ZHANG; He-ping CHENG; Jie LIU

    2006-01-01

    Calcium(Ca2+) and reactive oxygen species(ROS)constitute the most important intracellular signaling molecules participating in the regulation and integration of diverse cellular functions.Here we briefly review cross-talk between the two prominent signaling systems that finely tune the homeostasis and integrate functionality of Ca2+ and ROS in different types of cells.Ca2+ modulates ROS homeostasis by regulating ROS generation and annihilation mechanisms in both the mitochondria and the cytosol.Reciprocal redox regulation of Ca2+ homeostasis occurs in different physiological and pathological processes,by modulating components of the Ca2+ signaling toolkit and altering characteristics of local and global Ca2+ signals.Functionally,interactions between Ca2+ and ROS signaling systems can be both stimulatory and inhibitory,depending on the type of target proteins,the ROS species,the dose,duration of exposure,and the cell contexts.Such extensive and complex cross-talk might enhance signaling coordination and integration,whereas abnormalities in either system might propagate into the other system and undermine the stability of both systems.

  19. Alveologenesis: key cellular players and fibroblast growth factor 10 signaling

    OpenAIRE

    Chao, Cho-Ming; Moiseenko, Alena; Zimmer, Klaus-Peter; Bellusci, Saverio

    2016-01-01

    Background Alveologenesis is the last stage in lung development and is essential for building the gas-exchanging units called alveoli. Despite intensive lung research, the intricate crosstalk between mesenchymal and epithelial cell lineages during alveologenesis is poorly understood. This crosstalk contributes to the formation of the secondary septae, which are key structures of healthy alveoli. Conclusions A better understanding of the cellular and molecular processes underlying the formatio...

  20. E2F1 Induces Pituitary Tumor Transforming Gene (PTTG1) Expression in Human Pituitary Tumors

    OpenAIRE

    Zhou, Cuiqi; Wawrowsky, Kolja; Bannykh, Serguei; Gutman, Shiri; Melmed, Shlomo

    2009-01-01

    Rb/E2F is dysregulated in murine and human pituitary tumors. Pituitary tumor transforming gene (PTTG1), a securin protein, is required for pituitary tumorigenesis, and PTTG1 deletion attenuates pituitary tumor development in Rb+/− mice. E2F1 and PTTG1 were concordantly overexpressed in 29 of 46 Rb+/− murine pituitary tissues and also in 45 of 80 human pituitary tumors (P < 0.05). E2F1 specifically bound the hPTTG1 promoter as assessed by chromatin immunoprecipitation and biotin-streptavidin p...

  1. Forms, Crosstalks, and the Role of Phospholipid Biosynthesis in Autophagy

    Directory of Open Access Journals (Sweden)

    Leanne Pereira

    2012-01-01

    Full Text Available Autophagy is a highly conserved cellular process occurring during periods of stress to ensure a cell's survival by recycling cytosolic constituents and making products that can be used in energy generation and other essential processes. Three major forms of autophagy exist according to the specific mechanism through which cytoplasmic material is transported to a lysosome. Chaperone-mediated autophagy is a highly selective form of autophagy that delivers specific proteins for lysosomal degradation. Microautophagy is a less selective form of autophagy that occurs through lysosomal membrane invaginations, forming tubes and directly engulfing cytoplasm. Finally, macroautophagy involves formation of new membrane bilayers (autophagosomes that engulf cytosolic material and deliver it to lysosomes. This review provides new insights on the crosstalks between different forms of autophagy and the significance of bilayer-forming phospholipid synthesis in autophagosomal membrane formation.

  2. Computed tomography of pituitary microadenoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung-Il; Katto, Keiichi; Tanaka, Teruhiko; Kosaka, Shiro; Kaimori, Mitsuhiro (Aomori Prefectural Central Hospital (Japan))

    1983-08-01

    Thirteen pituitary microadenomas detected by Delta Scan 2020 are presented, and their CT findings are analyzed in points of size, shape, limit, density and contrast enhancement. All are demonstrated as a round, well defined and homogeneous mass, and are enhanced by contrast medium. The average size is 6.2 by 7.6 mm in diameter. Two of them are prolactinoma, and are treated by Bromocriptine. The prolactinomas vanished on CT scan, 6 months after administration of Bromocriptine. Eleven of them are nonfunctioning. Five are operated and the others are followed by CT scan. In detection of pituitary microadenoma, overlapping scanning with thin-slice is necessary and coronal scanning is often helpful. The adenoma greater than 5 mm in diameter may be detectable.

  3. Bromocriptine induces parapoptosis as the main type of cell death responsible for experimental pituitary tumor shrinkage

    International Nuclear Information System (INIS)

    Bromocriptine (Bc) produces pituitary tumoral mass regression which induces the cellular death that was classically described as apoptosis. However, recent works have related that other mechanisms of cell death could also be involved in the maintenance of physiological and pathological pituitary homeostasis. The aim of this study was to evaluate and characterize the different types of cell death in the involution induced by Bc in experimental rat pituitary tumors. The current study demonstrated that Bc induced an effective regression of estrogen induced pituitary tumors by a mechanism identified as parapoptosis. This alternative cell death was ultrastructurally recognized by extensive cytoplasmic vacuolization and an increased cell electron density, represented around 25% of the total pituitary cells counted. Furthermore, the results obtained from biochemical assays did not correspond to the criteria of apoptosis or necrosis. We also investigated the participation of p38, ERK1/2 and PKCδ in the parapoptotic pathway. An important observation was the significant increase in phosphorylated forms of these MAPKs, the holoenzyme and catalytic fragments of PKCδ in nuclear fractions after Bc administration compared to control and estrogen treated rats. Furthermore, the immunolocalization at ultrastructural level of these kinases showed a similar distribution pattern, with a prevalent localization at nuclear level in lactotrophs from Bc treated rats. In summary, we determined that parapoptosis is the predominant cell death type involved in the regression of pituitary tumors in response to Bc treatment, and may cause the activation of PKCδ, ERK1/2 and p38.

  4. Light bodies in human pituitary adenomas

    DEFF Research Database (Denmark)

    Holck, S; Wewer, U M; Albrechtsen, R

    1987-01-01

    Light bodies are large cytoplasmic granules originally described in the gonadotrophic cells of the rat pituitary gland. In order to determine whether similar bodies occur in the human anterior pituitary gland, 89 pituitary adenomas and periadenomatous tissue from 20 cases were examined by...... cells in periadenomatous tissue from 20 cases. These results show that some human pituitary adenomas may contain light bodies identical to those seen in gonadotrophs of rat pituitary....... transmission electron microscopy. Double membrane bound bodies with filamentous internal structure identical to rodent light bodies were identified in 10 hormone-producing adenomas: 5 PRL, 1 PRL-GH, 2 GH, and 2 ACTH-producing tumours. No light bodies were found in the remaining 79 tumours nor in the pituitary...

  5. Gamma knife radiosurgery for pituitary adenomas.

    Science.gov (United States)

    Ježková, Jana; Marek, Josef

    2016-09-01

    Pituitary adenomas are frequently occurring intracranial neoplasms. The aim of the treatment of pituitary adenomas is to normalize hormonal hypersecretion, to preserve the normal pituitary function, to reserve or treat impaired pituitary function and to control tumor growth and its mechanical effects on the surrounding structures. Treatment modalities include surgical, medical and radiation therapy. Radiosurgery is mainly used as a secondary line treatment after surgery for residual or recurrent tumors. The antiproliferative effect is achieved by LKG irradiation in more than 90% of patients. Regarding the functioning pituitary adenomas, the manifestation of the treatment effect is slow and depends mainly on the type of adenoma. Gamma knife irradiation is safe when the maximal doses to pituitary and infundibulum are respected. PMID:26899535

  6. A heritable predisposition to pituitary tumors

    OpenAIRE

    Couldwell, William T.; Cannon-Albright, Lisa

    2010-01-01

    Pituitary tumors are prevalent in the general population, with a frequency of nearly 1 in 5. The cause of most pituitary tumors remains unknown, although a genetic contribution is recognized for some. We analyzed the Utah Population Data Base (UPDB), a resource combining a computerized genealogy of the Utah population with a statewide tumor registry, to investigate familial clustering of pituitary tumors. We analyzed the genetic relationships among 741 individuals diagnosed with benign or mal...

  7. A Rare Cause of Hypopituitarism: Pituitary Tuberculosis

    Directory of Open Access Journals (Sweden)

    Şazi İmamoğlu

    2012-03-01

    Full Text Available Pituitary tuberculosis is a rare condition that can present with hypopituitarism even without any evidence of systemic tuberculosis and is easily confused with pituitary adenomas. Headache and hypopituitarism are the most common presenting symptoms. We report the case of pituitary tuberculosis in a 39-year-old male patient who presented with panhypopituitarism. Although it is rare and difficult to diagnose, pituitary tuberculosis should be considered in every nonfunctional sellar masses, especially in fairly small ones with unexpected hypopituitarism. Turk Jem 2012; 16: 26-8

  8. Tablets or scalpel: Pituitary hyperplasia due to primary hypothyroidism

    Directory of Open Access Journals (Sweden)

    Ahmed Imran Siddiqi, MBBS, MRCP

    2015-01-01

    Full Text Available We describe a patient with pituitary hyperplasia due to primary hypothyroidism. Pituitary hyperplasia and pituitary masses cannot be reliably differentiated on imaging alone, despite significant improvement in imaging quality in recent years.

  9. Afterpulse and delayed crosstalk analysis on a STMicroelectronics silicon photomultiplier

    Science.gov (United States)

    Nagy, Ferenc; Mazzillo, Massimo; Renna, Lucio; Valvo, Giuseppina; Sanfilippo, Delfo; Carbone, Beatrice; Piana, Angelo; Fallica, Giorgio; Molnár, József

    2014-09-01

    Crosstalk and afterpulsing in silicon photomultipliers can strongly limit the photon-counting resolution and dynamic range of the sensors. In this work we present a method and a measurement (as a demonstration) to separate the afterpulse and delayed crosstalk components of the delayed correlated pulses in STMicroelectronics silicon photomultiplier signals. The contribution of delayed crosstalk can be significant since even if one suppresses afterpulses by applying a longer recharge time, the delayed crosstalk component remains unaffected. This was the case for our measurement: 207 ns recharge was long enough to suppress afterpulses (3.3%), while the delayed crosstalk remained large (12.8%).

  10. Anatomy, Physiology, and Laboratory Evaluation of the Pituitary Gland.

    Science.gov (United States)

    Hong, Gregory K; Payne, Spencer C; Jane, John A

    2016-02-01

    The pituitary gland functions prominently in the control of most endocrine systems in the body. Diverse processes such as metabolism, growth, reproduction, and water balance are tightly regulated by the pituitary in conjunction with the hypothalamus and various downstream endocrine organs. Benign tumors of the pituitary gland are the primary cause of pituitary pathology and can result in inappropriate secretion of pituitary hormones or loss of pituitary function. First-line management of clinically significant tumors often involves surgical resection. Understanding of normal pituitary physiology and basic testing strategies to assess for pituitary dysfunction should be familiar to any skull base surgeon. PMID:26614827

  11. New formulas for interferometric crosstalk penalty as a function of total crosstalk power, number of crosstalk contributions and signal extinction ratio

    DEFF Research Database (Denmark)

    Rasmussen, Christian Jørgen; Jeppesen, Palle

    2000-01-01

    destructive phenomena in optical networks owing to its accumulative nature and strong impact on the transmission quality. New formulas state the crosstalk penalty as a function of the total crosstalk power, the number of contributions carrying this power and the signal extinction ratio. We consider both PIN...... and optically preamplified receivers. The authors know of no other published formulas which include the number of crosstalk contributions. The crosstalk penalty formulas are empirical, and they are based on a numerical model. This model is described briefly along with its experimental verification...

  12. Pituitary Gigantism: A Case Report

    Directory of Open Access Journals (Sweden)

    Rana Bhattacharjee

    2012-01-01

    Full Text Available Objective: To present a rare case of gigantism. Case Report: A 25-year-old lady presented with increased statural growth and enlarged body parts noticed since the age of 14 years, primary amenorrhea, and frontal headache for the last 2 years.She has also been suffering from non-inflammatory low back pain with progressive kyphosis and pain in the knees, ankles, and elbows for the last 5 years. There was no history of visual disturbance, vomiting, galactorrhoea, cold intolerance. She had no siblings. Family history was non-contributory.Blood pressure was normal. Height 221 cm, weight 138 kg,body mass index (BMI28. There was coarsening of facial features along with frontal bossing and prognathism, large hands and feet, and small goitre. Patient had severe kyphosis and osteoarthritis of knees. Confrontation perimetry suggested bitemporal hemianopia. Breast and pubic hair were of Tanner stage 1. Serum insulin like growth factor-1 (IGF1 was 703 ng/ml with all glucose suppressedgrowth hormone (GHvalues of >40 ng/ml. Prolactin was 174 ng/ml. Basal serum Lutenising Hormone (LH, follicle stimulating Hormone (FSH was low. Oral glucose tolerance test (OGTT, liver and renal function tests, basal cortisol and thyroid profile, Calcium, phosphorus and Intact Parathyroid hormone (iPTH were normal.Computed tomographyscan of brain showed large pituitary macroadenoma. Automated perimetry confirmed bitemporal hemianopia. A diagnosis of gigantism due to GH secreting pituitary macroadenoma with hypogonadotrophichypogonadism was made. Debulking pituitary surgery followed by somatostatin analogue therapy with gonadal steroid replacement had been planned, but the patient refused further treatment.

  13. Radiation Therapy of Pituitary Tumors

    International Nuclear Information System (INIS)

    Radiation treatment results were analyzed in a retrospective analysis of 47 patients with pituitary adenoma treated with radiation alone or combined with surgery from 1974 through 1987 at the Department of Therapeutic Radiology of Kyung Hee University. The 5-year overall survival rates for all patients was 80.4%. Radiation therapy was effective for improving visual symptoms and headache, but could not normalize amenorrhea and galactorrhoea. There was no difference of survival rate between radiation alone and combination with surgery. Prognostic factors such as age, sex, disease type, visual field, headache and surgical treatment were statistically no significant in survival rates of these patients

  14. NMR characterization of pituitary tumors

    International Nuclear Information System (INIS)

    Twelve patients (5 male, 7 female, mean age 37.9 +- 20) with pituitary tumors were extensively evaluated with NMR imaging using a 1.5K gauss resistive magnet. Saturation recovery (SR), inversion recovery (IR) and spin echo (SE) pulse sequences were used for qualitative characterization of the lesions. T/sub 1/ calculations were also performed for brain and pituitary. Tumor histology and endocrine status were correlated with NMR data. All tumors were large with suprasellar extension (6 with prolactin secretion, 6 without). Pituitary T/sub 1/'s ranged from .2 to .64, the mean T/sub 1/ being longer than that of brain (Brain = .4 +- .04; Pit = .48 +- .14). 3 patients with histological evidence of homogeneous adenomas had long T/sub 1/'s (0.58 +- .05). 3 patients with evidence of recent or old hemorhage into the pituitary had much shorter T/sub 1/'s (0.29 +- .12). There was no relationship between prolactin secretion and T/sub 1/. Qualitative T/sub 1/ and T/sub 2/ information can be obtained by using a combination of SR, IR, and SE images. Using this method in the patients, homogeneous adenomas had similar T/sub 1/'s and longer T/sub 2/'s compared to the brain, while patients with bleeds had shorter T/sub 1/'s and T/sub 2/'s. Image T/sub 1/ characteristics correlated well with the calculated T/sub 1/ values. The range of T/sub 1/ (and potentially T/sub 2/) values which occur in apparently similar lesions are most likely due to anatomical and pathophysiological variations in these lesions. It may be ultimately possible to separate different types of pathological processes based on NMR image T/sub 1/ and T/sub 2/ characteristics after careful comparative studies of NMR and histological data are completed. The combination of calculated T/sub 1/ and T/sub 2/ with image T/sub 1/ and T/sub 2/ information may also be useful in further characterization of lesions

  15. PageRank-based identification of signaling crosstalk from transcriptomics data: the case of Arabidopsis thaliana.

    Science.gov (United States)

    Omranian, Nooshin; Mueller-Roeber, Bernd; Nikoloski, Zoran

    2012-04-01

    The levels of cellular organization, from gene transcription to translation to protein-protein interaction and metabolism, operate via tightly regulated mutual interactions, facilitating organismal adaptability and various stress responses. Characterizing the mutual interactions between genes, transcription factors, and proteins involved in signaling, termed crosstalk, is therefore crucial for understanding and controlling cells' functionality. We aim at using high-throughput transcriptomics data to discover previously unknown links between signaling networks. We propose and analyze a novel method for crosstalk identification which relies on transcriptomics data and overcomes the lack of complete information for signaling pathways in Arabidopsis thaliana. Our method first employs a network-based transformation of the results from the statistical analysis of differential gene expression in given groups of experiments under different signal-inducing conditions. The stationary distribution of a random walk (similar to the PageRank algorithm) on the constructed network is then used to determine the putative transcripts interrelating different signaling pathways. With the help of the proposed method, we analyze a transcriptomics data set including experiments from four different stresses/signals: nitrate, sulfur, iron, and hormones. We identified promising gene candidates, downstream of the transcription factors (TFs), associated to signaling crosstalk, which were validated through literature mining. In addition, we conduct a comparative analysis with the only other available method in this field which used a biclustering-based approach. Surprisingly, the biclustering-based approach fails to robustly identify any candidate genes involved in the crosstalk of the analyzed signals. We demonstrate that our proposed method is more robust in identifying gene candidates involved downstream of the signaling crosstalk for species for which large transcriptomics data sets

  16. Angioscan exploration of morphology of pituitary adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Tabarin, A.; David, J.P.; Drouillard, J. and others

    1987-01-01

    Considerable progress has been made in the morphologic study of pituitary due to the availability of angioscan programs. An exceptional case is presented of a persistent intrasellar trigeminal artery associated with prolactinoma. Based on technological progress in CT scan imaging the place of angiographic explorations in the investigation of pituitary adenoma is reconsidered.

  17. Regression of pituitary macroadenoma after intratumoral hemorrhage

    International Nuclear Information System (INIS)

    Pituitary apoplexy syndrome is rarely recognized, whereas it can be the first sign of a nonfunctioning adenoma. It is caused by degenerative changes of vascular origin, necrotic and/or hemorrhagic, which can involve a normal gland or a pituitary tumor. It can be found in 0.6% to 9% of all pituitary tumors. Regression of the tumor mass can occasionally occur in patients after pituitary apoplexy. The authors present a case of pituitary macroadenoma regression as the result of hemorrhage into the tumor in a patient with clinical signs of pituitary apoplexy. Three MR examinations (at intervals of three and nine months) revealed the evolution of a hemorrhage within the tumor as well as an evident decrease in adenoma size. Because of the complete regression of clinical symptoms and hormonal inactivity of the tumor, the previously planned surgery was not performed. It is important to remember the possibility of pituitary apoplexy, also in nonfunctioning adenomas. Conservative treatment should be considered when the clinical symptoms of pituitary apoplexy resolve in a patient with a nonfunctioning adenoma. (author)

  18. Theoretical and experimental studies of the influence of the number of crosstalk signals on the penalty caused by incoherent optical crosstalk

    DEFF Research Database (Denmark)

    Rasmussen, Christian Jørgen; Liu, Fenghai; Pedersen, Rune Johan Skullerud;

    1999-01-01

    Calculations based on the exact probability density function of the received power show that for a fixed total crosstalk power, the incoherent crosstalk penalty increases with the number of crosstalk signals. Performed experiments verify this.......Calculations based on the exact probability density function of the received power show that for a fixed total crosstalk power, the incoherent crosstalk penalty increases with the number of crosstalk signals. Performed experiments verify this....

  19. Magnetic resonance imaging of pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Bonneville, Jean-Francois; Bonneville, Fabrice; Cattin, Francoise [University Hospital, Department of Neuroradiology, Besancon (France)

    2005-03-01

    Today, MR is the only method needed for the morphological investigation of endocrine-active pituitary adenomas. In acromegaly and Cushing's syndrome, the therapeutic attitude is directly dictated by MR data. We present the MR aspect of pituitary adenomas according to size, sex, age, endocrine activity and a few particular conditions such as hemorrhagic pituitary adenomas, pituitary adenomas during pregnancy, cavernous sinus invasion and postsurgical changes. When an intrasellar mass extending out of the sella turcica is detected, the goal of the MR examination is to indicate precisely the origin of the tumor, its extension in relation to the various surrounding structures, its structure and its enhancement in order to help in the differential diagnosis. Demonstration of very small pituitary adenomas remains a challenge. When SE T1- and Turbo SE T2-weighted sequences are non-diagnostic, enhanced imaging becomes mandatory; half-dose gadolinium injection, delayed sequence, dynamic imaging can be of some help. (orig.)

  20. Pituitary stem cells: candidates and implications.

    Science.gov (United States)

    Nassiri, Farshad; Cusimano, Michael; Zuccato, Jeff A; Mohammed, Safraz; Rotondo, Fabio; Horvath, Eva; Syro, Luis V; Kovacs, Kalman; Lloyd, Ricardo V

    2013-09-01

    The pituitary is the master endocrine gland of the body. It undergoes many changes after birth, and these changes may be mediated by the differentiation of pituitary stem cells. Stem cells in any tissue source must display (1) pluripotent capacity, (2) capacity for indefinite self-renewal, and (3) a lack of specialization. Unlike neural stem cells identified in the hippocampus and subventricular zone, pituitary stem cells are not associated with one specific cell type. There are many major candidates that are thought to be potential pituitary stem cell sources. This article reviews the evidence for each of the major cell types and discuss the implications of identifying a definitive pituitary stem cell type. PMID:23423660

  1. Transcriptional Crosstalk between Nuclear Receptors and Cytokine Signal Transduction Pathways in Immunity

    Institute of Scientific and Technical Information of China (English)

    LihuaWang; XiaohuZhang; WilliamL.Farrar

    2004-01-01

    The nuclear receptor superfamily and the transcriptional factors associated with cytokines are inherently different families of signaling molecules and activate gene transcription by binding to their respective responsive element. However, it has become increasingly clear from our works and others that nuclear receptors are important regulators of cytokine production and function through complex and varied interactions between these distinct transcriptional factors. This review provides a general overview of the mechanism of action of nuclear receptors and their transcriptional crosstalk with transcriptional factors associated with cytokine transduction pathways. One of the most important mechanistic aspects is protein to protein interaction through a direct or co-regulator-mediated indirect manner. Such crosstalk is crucially involved in physiological and therapeutic roles of nuclear receptors and their ligands in immunity,inflammation and cytokine-related tumors. Cellular & Molecular Immunology. 2004;1(6):416-424.

  2. Crosstalk Reduction for Superconducting Microwave Resonator Arrays

    CERN Document Server

    Noroozian, Omid; Eom, Byeong Ho; Leduc, Henry G; Zmuidzinas, Jonas; 10.1109/TMTT.2012.2187538

    2012-01-01

    Large-scale arrays of Microwave Kinetic Inductance Detectors (MKIDs) are attractive candidates for use in imaging instruments for next generation submillimeter-wave telescopes such as CCAT. We have designed and fabricated tightly packed ~250-pixel MKID arrays using lumped-element resonators etched from a thin layer of superconducting TiNx deposited on a silicon substrate. The high pixel packing density in our initial design resulted in large microwave crosstalk due to electromagnetic coupling between the resonators. Our second design eliminates this problem by adding a grounding shield and using a double-wound geometry for the meander inductor to allow conductors with opposite polarity to be in close proximity. In addition, the resonator frequencies are distributed in a checkerboard pattern across the array. We present details for the two resonator and array designs and describe a circuit model for the full array that predicts the distribution of resonator frequencies and the crosstalk level. We also show res...

  3. Effects of Prenatal Dexamethasone on the Rat Pituitary Gland and Gonadotropic Cells in Female Offspring.

    Science.gov (United States)

    Ristić, Nataša; Severs, Walter; Nestorović, Nataša; Jarić, Ivana; Manojlović-Stojanoski, Milica; Trifunović, Svetlana; Pendovski, Lazo; Milosević, Verica

    2016-01-01

    Glucocorticoids have a strong influence on growth and maturation of fetal organ systems, but overexposure to exogenous glucocorticoids may retard fetal growth and alter developmental processes in sensitive tissues. The aim of this study was to specifically determine whether prenatal exposure to dexamethasone (Dx) altered normal development and function of pituitary gonadotropic cells in neonatal, infant and peripubertal female offspring. On day 16 of pregnancy, rat dams received 1.0 mg Dx/kg body weight (BW) s.c., followed by 0.5 mg Dx/kg BW on days 17 and 18 of gestation. Control gravid females received the same volume of saline. Female offspring were sacrificed on days 5, 16 and 38 after delivery. The volume of the pituitary gland estimated using Cavalieri's principle was significantly reduced (p programming of the female reproductive system at the pituitary cellular level, which may be associated with impaired reproductive function. PMID:26950885

  4. Normal MR appearances of the posterior pituitary in central diabetes insipidus associated with septo-optic dysplasia

    International Nuclear Information System (INIS)

    Magnetic resonance (MR) imaging of the pituitary in children with central diabetes insipidus usually shows absence of the normal high signal within the posterior gland. The high signal of the normal posterior pituitary is thought to be due to the presence of intra- cellular storage granules of vasopressin. MR imaging has been advocated as a useful investigation to aid in the distinction between central diabetes insipidus and other causes of thirst and polydipsia. We report the case of an infant with central diabetes insipidus in association with septo-optic dysplasia in whom MR imaging showed normal appearances of the posterior pituitary. The mechanism of central diabetes insipidus in this case may be related to a failure of hypothalamic function affecting osmoreception, rather than to a deficiency of vasopressin. Normal MR appearances of the pituitary do not exclude central diabetes insipidus in infants with midline cerebral malformations. (orig.). With 1 fig

  5. Normal MR appearances of the posterior pituitary in central diabetes insipidus associated with septo-optic dysplasia

    Energy Technology Data Exchange (ETDEWEB)

    Abernethy, L.J. [Dept. of Radiology, Royal Liverpool Children`s Hospital, Liverpool (United Kingdom); Qunibi, M.A. [Depts. of Radiology and Child Health, Royal Liverpool Children`s Hospital, Liverpool (United Kingdom); Smith, C.S. [Depts. of Radiology and Child Health, Royal Liverpool Children`s Hospital, Liverpool (United Kingdom)

    1997-01-01

    Magnetic resonance (MR) imaging of the pituitary in children with central diabetes insipidus usually shows absence of the normal high signal within the posterior gland. The high signal of the normal posterior pituitary is thought to be due to the presence of intra- cellular storage granules of vasopressin. MR imaging has been advocated as a useful investigation to aid in the distinction between central diabetes insipidus and other causes of thirst and polydipsia. We report the case of an infant with central diabetes insipidus in association with septo-optic dysplasia in whom MR imaging showed normal appearances of the posterior pituitary. The mechanism of central diabetes insipidus in this case may be related to a failure of hypothalamic function affecting osmoreception, rather than to a deficiency of vasopressin. Normal MR appearances of the pituitary do not exclude central diabetes insipidus in infants with midline cerebral malformations. (orig.). With 1 fig.

  6. Comparison of objective metrics for image sensor crosstalk characterization

    Science.gov (United States)

    Li, Feng; Eliasson, Henrik; Dokoutchaev, Alexander

    2011-01-01

    Image sensor crosstalk can be divided into spectral crosstalk and pixel crosstalk. This paper focuses on the pixel crosstalk and its effect on signal to noise ratio (SNR). Pixel crosstalk occurs in the spatial domain and is due to the signal leakage between adjacent pixels either by imperfect optical isolation or diffusion of electrons. This will have a negative impact on image quality mainly in two ways: spatial blurring and decreased SNR due to more aggressive color correction required. A method for modeling the spectral broadening due to the pixel crosstalk is used where a matrix is calculated from crosstalk kernels representing the spatial leakage between neighboring pixels. In order to quantify the amount of crosstalk we present a method in which ratios of integrals of the same color channel but within different wavelength intervals are calculated. This provides a metric that is more robust with respect to color channel scaling. To study the impact on SNR due to pixel crosstalk, a number of SNR metrics are compared to results from a limited psychophysical study. The studied SNR metrics are the metric used for calculating the SNR10 value in mobile imaging, the ISO 12232 noise metric and a metric where the signal is transformed into orthogonal color opponent channels, thereby enabling the analysis of the luminance noise separate from the chrominance noises. The results indicate that the ISO total noise and SNR10 metric yield very similar results and that the green channel has the largest individual impact on the crosstalk.

  7. Preliminary Study on the Relationship between cAMP Level and gsp Expression in Cultured Human Pituitary Somatotrophinomas

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to investigate the relationship between abnormal intracellular signal transduction and tumorgenesis of human pituitary somatotrophinomas, the effects of protein kinase A (PKA)-dependent growth hormone (GH) releasing hormone (GHRH) and protein kinase C (PKC)-dependent GH-releasing peptide (GHRP-6) on cAMP production were observed by using cell culture and biochemical methods, and the expression of the gsp oncogene was detected by using PCR and direct sequence assay methods in 11 patients with human pituitary somatotrophinomas. It was found that GHRP-6 exerted significant stimulatory effect on cAMP production by 2 gsp-positive tumors and no effect on the gsp-negative tumors. GHRP-6 could enhance the stimulation of cAMP production induced by GHRH in tumor without gsp oncogenes. It was suggested that both GHRH and GHRP-6 exert identical effects on human pituitary soamtotrophinomas, which was contributed to the cross-talk between the two intracellular signal transduction pathways in pituitary cells.

  8. Arrestin orchestrates cross-talk between GPCRs to modulate the spatiotemporal activation of ERK MAPK

    Science.gov (United States)

    Cervantes, David; Crosby, Catherine; Xiang, Yang

    2009-01-01

    Rationale G protein-coupled receptors (GPCRs) respond to diversified extracellular stimuli to modulate cellular function. Despite extensive studies investigating the regulation of single GPCR signaling cascades, the effects of concomitant GPCR activation on downstream signaling and cellular function remain unclear. Objective We aim to characterize the cellular mechanism by which GPCR cross-talk regulates MAPK activation. Methods and Results Adrenergic receptors on cardiac fibroblasts were manipulated to examine the role of arrestin in the spatiotemporal regulation of ERK1/2 MAPK signaling. We show a general mechanism in which arrestin activation by one GPCR is capable of regulating signaling originating from another GPCR. Activation of Gq-coupled receptor signaling leads to prolonged ERK1/2 MAPK phosphorylation, nuclear accumulation and cellular proliferation. Interestingly, co-activation of these receptors with the β adrenergic receptors (ARs) induced transient ERK signaling localized within the cytosol, which attenuated cell proliferation. Further studies revealed that recruitment of arrestin3 to the β2AR orchestrates the sequestration of Gq-coupled receptor-induced ERK to the cytosol through direct binding of ERK to arrestin. Conclusion This is the first evidence showing that arrestin3 acts as a coordinator to integrate signals from multiple GPCRs. Our studies not only provide a novel mechanism explaining the integration of mitogenic signaling elicited by different GPCRs, but also underscore the critical role of signaling cross-talk among GPCRs in vivo. PMID:19926878

  9. Intrinsic limits to gene regulation by global crosstalk.

    Science.gov (United States)

    Friedlander, Tamar; Prizak, Roshan; Guet, Călin C; Barton, Nicholas H; Tkačik, Gašper

    2016-01-01

    Gene regulation relies on the specificity of transcription factor (TF)-DNA interactions. Limited specificity may lead to crosstalk: a regulatory state in which a gene is either incorrectly activated due to noncognate TF-DNA interactions or remains erroneously inactive. As each TF can have numerous interactions with noncognate cis-regulatory elements, crosstalk is inherently a global problem, yet has previously not been studied as such. We construct a theoretical framework to analyse the effects of global crosstalk on gene regulation. We find that crosstalk presents a significant challenge for organisms with low-specificity TFs, such as metazoans. Crosstalk is not easily mitigated by known regulatory schemes acting at equilibrium, including variants of cooperativity and combinatorial regulation. Our results suggest that crosstalk imposes a previously unexplored global constraint on the functioning and evolution of regulatory networks, which is qualitatively distinct from the known constraints that act at the level of individual gene regulatory elements. PMID:27489144

  10. Subcellular localization of pituitary enzymes

    Science.gov (United States)

    Smith, R. E.

    1970-01-01

    A cytochemical procedure is reported for identifying subcellular sites of enzymes hydrolyzing beta-naphthylamine substrates, and to study the sites of reaction product localization in cells of various tissues. Investigations using the substrate Leu 4-methoxy-8-naphthylamine, a capture with hexonium pararosaniline, and the final chelation of osmium have identified the hydrolyzing enzyme of rat liver cells; this enzyme localized on cell membranes with intense deposition in the areas of the parcanaliculi. The study of cells in the anterior pituitary of the rat showed the deposition of reaction product on cell membrane; and on the membranes of secretion granules contained within the cell. The deposition of reaction product on the cell membrane however showed no increase or decrease with changes in the physiological state of the gland and release of secretion granules from specific cells.

  11. Imaging of the pituitary: Recent advances

    Directory of Open Access Journals (Sweden)

    Vikas Chaudhary

    2011-01-01

    Full Text Available Pituitary lesions, albeit relatively infrequent, can significantly alter the quality of life. This article highlights the role of advanced imaging modalities in evaluating pituitary-hypothalamic axis lesions. Magnetic resonance imaging (MRI is the examination of choice for evaluating hypothalamic-pituitary-related endocrine diseases. Advanced MR techniques discussed in this article include dynamic contrast-enhanced MRI, 3T MRI, magnetization transfer (MT imaging, diffusion-weighted imaging (DWI, proton MR spectroscopy, fluorine-18 fluorodeoxyglucose-positron emission tomography, single-photon emission computed tomography, intraoperative MRI, and intraoperative real-time ultrasonography.

  12. Management of incidental pituitary tumors

    Directory of Open Access Journals (Sweden)

    Nicholas F. Marko

    2011-11-01

    Full Text Available Pituitary incidentalomas are common lesions for which neurosurgical referrals may become progressively more frequent, given the increasing application of neuroimaging. The initial evaluation of a patient with radiographic evidence of an incidentaloma should focus on addressing two questions: (1 is the lesion causing neurological symptoms, and (2 is the lesion hormonally active? The answers to these two questions provide a framework for subsequent clinical management. The initial patient assessment should include a detailed history and physical examination, including the bedside assessment of visual fields. High-quality MRI imaging is essential, and formal visual field testing should be obtained in patients where the lesion abuts or compresses the optic apparatus. The initial biochemical workup is intended to assess potential pituitary hypo- or hyperfunction and should include measurement of serum levels of prolactin, insulin-like growth factor type-1, free thyroxine, testosterone, and an assessment of axis hypothalamic–pituitary–adrenal axis function. Additional testing may include serum thyroid-stimulating hormone, follicle-stimulating hormone, and luteinizing hormone levels. Neurologically-asymptomatic patients without endocrine dysfunction can be managed with observation at regular intervals, including MRI imaging at 6 months and 1 year and then annually for a period of 3 years. Follow-up biochemical assessment is not necessary in the absence of clinical symptoms or radiographic enlargement of the lesion. After 3 years the follow-up interval may be prolonged, although closer follow-up may be indicated for patients with lesions C1 cm. Most patients who either present with or who subsequently develop neurologic or endocrinologic symptoms should be considered for surgery as the first-line therapy.

  13. Hypothalamus-Pituitary-Thyroid Axis.

    Science.gov (United States)

    Ortiga-Carvalho, Tania M; Chiamolera, Maria I; Pazos-Moura, Carmen C; Wondisford, Fredic E

    2016-01-01

    The hypothalamus-pituitary-thyroid (HPT) axis determines the set point of thyroid hormone (TH) production. Hypothalamic thyrotropin-releasing hormone (TRH) stimulates the synthesis and secretion of pituitary thyrotropin (thyroid-stimulating hormone, TSH), which acts at the thyroid to stimulate all steps of TH biosynthesis and secretion. The THs thyroxine (T4) and triiodothyronine (T3) control the secretion of TRH and TSH by negative feedback to maintain physiological levels of the main hormones of the HPT axis. Reduction of circulating TH levels due to primary thyroid failure results in increased TRH and TSH production, whereas the opposite occurs when circulating THs are in excess. Other neural, humoral, and local factors modulate the HPT axis and, in specific situations, determine alterations in the physiological function of the axis. The roles of THs are vital to nervous system development, linear growth, energetic metabolism, and thermogenesis. THs also regulate the hepatic metabolism of nutrients, fluid balance and the cardiovascular system. In cells, TH actions are mediated mainly by nuclear TH receptors (210), which modify gene expression. T3 is the preferred ligand of THR, whereas T4, the serum concentration of which is 100-fold higher than that of T3, undergoes extra-thyroidal conversion to T3. This conversion is catalyzed by 5'-deiodinases (D1 and D2), which are TH-activating enzymes. T4 can also be inactivated by conversion to reverse T3, which has very low affinity for THR, by 5-deiodinase (D3). The regulation of deiodinases, particularly D2, and TH transporters at the cell membrane control T3 availability, which is fundamental for TH action. © 2016 American Physiological Society. Compr Physiol 6:1387-1428, 2016. PMID:27347897

  14. New method for enhancing contrast between pituitary tumor and surrounding nontumorous pituitary tissue

    International Nuclear Information System (INIS)

    The authors have performed serial dynamic MR imaging after bolus injection of Gd-DTPA in 10 patients with normal pituitary glands showed marked enhancement in the early phase of the dynamic study, followed by gradual intensity reduction throughout the late phase. Pituitary adenoma showed gradually increasing enhancement throughout the dynamic study. Adenoma, surrounding nontumorous pituitary tissue, and cavernous sinus are clearly distinguished in the early phase of the dynamic study in all micro or macroadenomas less than 15 mm

  15. Postirradiation sarcomatous transformation of a pituitary adenoma: a combined pituitary tumor. Case report

    International Nuclear Information System (INIS)

    A case is reported in which a fibrosarcoma developed 20 years after irradiation of a pituitary chromophobe adenoma. This rare lesion, like most of the other documented postirradiation pituitary sarcomas, was a combination of fibrosarcoma and pituitary adenoma. These lesions tend to behave in a characteristic fashion, with onset after a long latent interval following irradiation, growth to a large size, and failure to metastasize

  16. Functional role of estrogen in pituitary tumor pathogenesis

    OpenAIRE

    Heaney, Anthony P.; Fernando, Manory; Melmed, Shlomo

    2002-01-01

    Pituitary hyperplasia and lactotroph replication are induced by estrogen. The product of the pituitary tumor transforming gene (PTTG) exhibits in vitro and in vivo transforming activity and induces basic bFGF secretion, thereby modulating pituitary angiogenesis and tumor formation. We demonstrated previously that pituitary pttg is induced by estrogen and bFGF, the latter being expressed in a concordant fashion with pttg in experimental and human pituitary adenomas. We now elucidate the role o...

  17. Dosimetric factors associated with pituitary function after Gamma Knife Surgery (GKS) of pituitary adenomas

    International Nuclear Information System (INIS)

    Background and purpose: Gamma Knife Surgery (GKS) can be an adjunctive option to surgery in the case of pituitary adenomas. The effect of dosimetric variables on the incidence of new anterior pituitary deficits after GKS requires better definition. Materials and methods: This retrospective study considered 130 patients with a follow up after GKS >6 months. The diagnosis was nonfunctioning pituitary adenoma (NFPA) in 68 patients and secreting pituitary adenoma (SPA) in 62 patients. Median margin dose was 15/25 Gy for NFPA and SPA, respectively. The endocrinological median follow-up was 60 months. Hypopituitarism was defined as a new pituitary deficit in (at least) one of the three hormonal axes (hypogonadism, hypothyroidism and hypoadrenalism). The predictive value of clinical/dosimetric parameters was tested by univariate/multivariate analyses. Results: Sixteen patients (12.3%) showed a new pituitary deficit in one or more axes. Multivariate analysis confirmed that the mean dose to the stalk/pituitary and the amount of healthy tissue within the high dose region were strong independent predictors of pituitary dysfunction; their best cut-off values were around 15.7 Gy, 7.3 Gy and 1.4 cm3, respectively. Conclusions: Our data showed a dose-dependent incidence of new hormonal deficits after GKS for pituitary adenoma. During planning definition, the risk of hypopituitarism could be reduced using the outlined safe dose–volume values.

  18. Signalling crosstalk in plants: emerging issues.

    Science.gov (United States)

    Taylor, Jane E; McAinsh, Martin R

    2004-01-01

    The Oxford English Dictionary defines crosstalk as 'unwanted transfer of signals between communication channels'. How does this definition relate to the way in which we view the organization and function of signalling pathways? Recent advances in the field of plant signalling have challenged the traditional view of a signalling transduction cascade as isolated linear pathways. Instead the picture emerging of the mechanisms by which plants transduce environmental signals is of the interaction between transduction chains. The manner in which these interactions occur (and indeed whether the transfer of these signals is 'unwanted' or beneficial) is currently the topic of intense research. PMID:14673021

  19. Pituitary macroadenomas: reviews of 60 cases

    International Nuclear Information System (INIS)

    We reviewed 60 cases of patients with pituitary macroadenomas who were submitted to magnetic resonance imaging evaluations at private institutions in Niteroi and Rio de Janeiro, Brazil. The aim of this study was to demonstrate the advantages of magnetic resonance imaging in the diagnosis and follow-up of these patients. Macroprolactinomas were the most prevalent tumors. We also observed four growth-hormone (GH) secreting macroadenomas with clinical signs of acromegaly, and one GH- and prolactin-secreting macroadenoma. Seven patients presented pituitary apoplexy and hyperintense signal on T1-W images before contrast medium (gadolinium) administration suggestive of intratumoral bleeding. The follow-up of 15 cases demonstrated a reduction in the size of the tumor after surgery, clinical treatment or radiotherapy. Magnetic resonance imaging is important for the study of pituitary macroadenomas, particularly before surgery, as it shows the involvement of adjacent structures, specially the cavernous sinus, optic chiasm and pituitary stalk compression. (author)

  20. Pituitary prolactin adenoma with Toxoplasma gondii infection

    Institute of Scientific and Technical Information of China (English)

    张晓晖; 李青; 程虹; 阎庆国; 黄高昇

    2003-01-01

    Objective: To report two recent cases of pituitary adenoma associated with Toxoplasma gondii (T.Gondii) infection.Methods: Histological changes were observed in H & E and PAS staining sections microscopically.Immunohistochemistry was performed to classify the pituitary tumors and to confirm the diagnosis of T.gondii.Results: The cases were 43- and 19-year-old females, in which the latter one was a recurring case, and radiology examination showed that tumors existed in sellar region.Microscopically, the tumors consisted of small homogenous polygonal or round cells with abundant eosinophilic granular cytoplasm.Immunohistochemistry revealed they were prolactin-producing adenomas.Interestingly, we found toxoplasma infection in the tumor tissues, being confirmed by T.gondii sepicific antibody immunohistochemistry.Conclusion: The association of pituitary adenoma with toxoplasma raises the possibility that T.gondii may be involved in the development of certain cases of pituitary adenoma.

  1. Metastases from a pituitary adenoma: MRI

    International Nuclear Information System (INIS)

    Few cases of pituitary adenoma with metastases have been reported. We report a case with histologically benign intracranial and cauda equina metastases. We compare it to the others in the literature. (orig.)

  2. Metastases from a pituitary adenoma: MRI

    Energy Technology Data Exchange (ETDEWEB)

    Boucaud, L. de; Dousset, V.; Viaud, B.; Caille, J.M. [Service de Neuroradiologie, CHU Pellegrin, Bordeaux (France); Caillaud, P.; Guerin, J. [Service de Neurochirurgie, CHU Pellegrin, Bordeaux (France)

    1999-10-01

    Few cases of pituitary adenoma with metastases have been reported. We report a case with histologically benign intracranial and cauda equina metastases. We compare it to the others in the literature. (orig.)

  3. Identification of metastases in the pituitary stalk

    International Nuclear Information System (INIS)

    Two cases of metastasis in the pituitary stalk are presented. In both cases, presenting with diabetes insipidus, the demonstration of a small (under 1 cm) metastasis in the pituitary stalk was possible using a current generation scanner. Patients with known primary tumors presenting with a diabetes insipidus should be examined by CT before therapy with antidiuretic hormone is initiated. In cases of visible metastasis, a specific therapy together with the hormone-substitution should be discussed. (orig.)

  4. Pituitary carcinoma with different hormone expressions

    Directory of Open Access Journals (Sweden)

    Tao LU

    2015-01-01

    Full Text Available Objective To introduce the experience of diagnosing and treating one case of pituitary carcinoma with distinct hormone expressions in primary and metastatic lesions and to improve understanding of this disease.  Methods Retrospective study was performed to analyze the clinical manifestations, imaging characteristics, histopathologic findings, and treatment information of the patient. Immunohistochemical staining was done to both primary and metastatic lesions.  Results The patient presented with eye pain and discomfort 4 months posterior to pituitary adenoma surgery. Head MRI showed multiple abnormal intracranial signals, irregular pituitary contour, and abnormal enhancements of the sellar region. PET-CT scan showed multiple hypermetabolic lesions. After the first surgery, histological study of the pituitary tumor showed disseminated tumor cells. The cells were round-shaped or polygonal, with mild atypia, moderate amount of eosinophilic plasma and round-shaped nuclei with fine chromatin and unconspicuous nucleoli; mitosis was abundant, while necrosis was absent. The tumor cells expressed P53, chromogranin A (CgA, with scattered expression for growth hormone (GH and a Ki-67 index of 80% by immunohistochemistry. The first pathologic diagnosis was atypical pituitary adenoma. The parietal tumor cells infiltrated parenchymal after the tumor recurrence. Immunohistochemistry findings were different from the first one. The tumor cells expressed GH diffusely, with a decreased Ki-67 index of 75%. The second pathologic diagnosis was metastatic pituitary carcinoma.  Conclusions Pituitary carcinoma is a rare malignant pituitary tumor. Diagnosis relies on radiology and pathology. Surgical resection and radiochemotherapy are the current treatment of choice but yield poor response. General prognosis of the disease is poor. DOI: 10.3969/j.issn.1672-6731.2015.01.013

  5. Pituitary Apoplexy Presented with Optic Neuritis

    Directory of Open Access Journals (Sweden)

    Mahsa Owji

    2013-07-01

    Full Text Available The patient is a 40-years-old woman presented with visual loss in the right eye since two days ago. The patient complained of headache with gradual onset in the right parietal area since 2 years ago. The headache pattern did not alter.The left eye was normal but the vision in the right eye was 50 cm finger counting. Marcus Gunn pupil could be observed during swinging-flashlight test in the right eye. According to these findings, the first diagnosis was optic neuritis which was corroborated with visual evoked potential (the latency of P100 was 122. According to magnetic resonance imaging (MRI, there was a big cystic tumor in sella turcica extended to the suprasellar region (Figure 1-A. It had a large liquid component. Optic chiasm was under pressure and was displaced (Figure 1-B. A faint enhancement was seen after the injection (Figure 1-C.The patient was operated with the transnasal-transsphenoidal approach. Blood and fibrin were among the small monomorphic round cells andfibro-connective tissue of the pituitary gland. Considering the bleeding inside the pituitary tumor, the final diagnosis was pituitary apoplexy. After recovery from the operation the symptoms were removed.Pituitary apoplexy presents with headache, loss of vision, ophthalmoplegia, and mental alterations which is caused by infarction or sudden bleeding inside the pituitary tumor.1In our review of literature, 3 patients afflicted with pituitary apoplexy presented with optic neuritis were reported.In a study conducted by Petersen et al., all three patients referred to them suffered from unilateral visual loss and headache. They were examined with the early diagnosis of optic neuritis. After taking a Brain Computerized tomography (CT scan, pituitary adenoma together with the formation of cyst were detected in patients. After transsphenoidal adenomectomy, the patient regained full vision. Therefore, the correct diagnosis of these patients, who had been incorrectly diagnosed with

  6. The various MRI patterns of pituitary apoplexy

    International Nuclear Information System (INIS)

    The aim of this study was to describe the various MRI features, in correlation to surgical and pathological findings, in patients who presented with pituitary apoplexy (PA). Eleven patients presenting with PA, were evaluated with various MR protocols including spin-echo (SE) T1-weighted sequences in 9 of 11 patients, post gadolinium SE T1-weighted sequences in only 8 of 11 patients, and with T2-weighted SE sequences in 2 of 11 patients. All patients had transsphenoidal pituitary surgery after MR studies. The severity of presenting symptoms ranged from headaches to coma. Ten patients had pituitary macroadenoma; one had a non-hemorrhagic metastatic lesion into a non-adenomatous pituitary gland. Of the 11 patients, one was studied at the acute stage of PA (1 day after onset), 9 at the subacute period (3-15 days after onset), and one at the late stage (5 months after onset). Images compatible with intratumoral hemorrhage were found in all macroadenomas, whereas the metastatic pituitary lesion did not show evidence of bleeding. All gadolinium-enhanced studies showed partial tumoral enhancement. The SE T2-weighted studies demonstrated areas of low and high signal intensities in keeping with the presence of blood degradation contents. Pituitary apoplexy present with different MR features, including hemorrhagic and non-hemorrhagic characteristics on T1-weighted images. Gadolinium-enhanced images do not provide complementary diagnostic information when the presence of blood is assessed on plain images. (orig.)

  7. Cellular metabolism regulates contact sites between vacuoles and mitochondria

    NARCIS (Netherlands)

    Hönscher, Carina; Mari, Muriel; Auffarth, Kathrin; Bohnert, Maria; Griffith, Janice; Geerts, Willie; van der Laan, Martin; Cabrera, Margarita; Reggiori, Fulvio; Ungermann, Christian

    2014-01-01

    Emerging evidence suggests that contact sites between different organelles form central hubs in the coordination of cellular physiology. Although recent work has emphasized the crucial role of the endoplasmic reticulum in interorganellar crosstalk, the cooperative behavior of other organelles is lar

  8. Mitochondria and endoplasmic reticulum crosstalk in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Manfredi, Giovanni; Kawamata, Hibiki

    2016-06-01

    Physical and functional interactions between mitochondria and the endoplasmic reticulum (ER) are crucial for cell life. These two organelles are intimately connected and collaborate to essential processes, such as calcium homeostasis and phospholipid biosynthesis. The connections between mitochondria and endoplasmic reticulum occur through structures named mitochondria associated membranes (MAMs), which contain lipid rafts and a large number of proteins, many of which serve multiple functions at different cellular sites. Growing evidence strongly suggests that alterations of ER-mitochondria interactions are involved in neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS), a devastating and rapidly fatal motor neuron disease. Mutations in proteins that participate in ER-mitochondria interactions and MAM functions are increasingly being associated with genetic forms of ALS and other neurodegenerative diseases. This evidence strongly suggests that, rather than considering the two organelles separately, a better understanding of the disease process can derive from studying the alterations in their crosstalk. In this review we discuss normal and pathological ER-mitochondria interactions and the evidence that link them to ALS. PMID:26282323

  9. Crosstalk between platelets and PBMC: New evidence in wound healing.

    Science.gov (United States)

    Nami, Niccolò; Feci, Luca; Napoliello, Luca; Giordano, Antonio; Lorenzini, Sauro; Galeazzi, Mauro; Rubegni, Pietro; Fimiani, Michele

    2016-01-01

    Platelet-derived products have proven useful in accelerating healing processes and tissue regeneration. However, despite their widespread use in clinical practice, the cellular and molecular mechanisms involved have not yet been completely clarified. Recent studies show that interaction between platelet gel (PG) and peripheral blood mononuclear cells (PBMC) can result in activation of PBMC and production of several cytokines involved in wound healing and tissue repair. The aim of our study was to analyze whether crosstalk between platelets and PBMC can influence wound healing by modulating release of VEGF, bFGF and IL-10 by PBMC. Cultures of PBMC alone and co-cultures with autologous PG of 24 healthy volunteers were incubated under normoxia for 24 h. VEGF, bFGF and IL-10 concentration and expression were then analyzed in supernatants by ELISA and by real-time RT-PCR. We observed a down-regulation of VEGF and bFGF release and an up-regulation of IL-10 release in co-cultures of PBMC and PG. Platelets are not only important in the early stages of the healing process (clot formation, direct release of growth factors), but also can influence the whole process of tissue regeneration by modulating synthesis and release of VEGF, bFGF and IL-10 by PBMC. These effects could give platelets a new key role in the control of healing processes and provide insights into the clinical success of platelet-derived products in many medical fields. PMID:26030799

  10. Pituitary tumor transforming gene-1 haplotypes and risk of pituitary adenoma: a case-control study

    Directory of Open Access Journals (Sweden)

    Liu Jinfang

    2011-03-01

    Full Text Available Abstract Background It has been suggested that pituitary adenoma results from accumulation of multiple genetic and/or epigenetic aberrations, which may be identified through association studies. As pituitary tumor transforming gene-1 (PTTG1/securin plays a critical role in promoting genomic instability in pituitary neoplasia, the present study explored the association of PTTG1 haplotypes with the risk of pituitary adenoma. Methods We genotyped five PTTG1 haplotype-tagging SNPs (htSNP by PCR-RFLP assays in a case-control study, which included 280 Han Chinese patients diagnosed with pituitary adenoma and 280 age-, gender- and geographically matched Han Chinese controls. Haplotypes were reconstructed according to the genotyping data and linkage disequilibrium status of the htSNPs. Results No significant differences in allele and genotype frequencies of the htSNPs were observed between pituitary adenoma patients and controls, indicating that none of the individual PTTG1 SNPs examined in this study is associated with the risk of pituitary adenoma. In addition, no significant association was detected between the reconstructed PTTG1 haplotypes and pituitary adenoma cases or the controls. Conclusions Though no significant association was found between PTTG1 haplotypes and the risk of pituitary adenoma, this is the first report on the association of individual PTTG1 SNPs or PTTG1 haplotypes with the risk of pituitary adenoma based on a solid study; it will provide an important reference for future studies on the association between genetic alterations in PTTG1 and the risk of pituitary adenoma or other tumors.

  11. Analysis of Inverse Crosstalk Channel Estimation Using SNR Feedback

    NARCIS (Netherlands)

    Whiting, P.A.; Kramer, G.; Nuzman, C.J.; Ashikhmin, A.; Wijngaarden, van A.J.; Zivkovic, M.

    2011-01-01

    Digital subscriber line (DSL) data rates for short loops are typically limited by crosstalk between adjacent lines rather than by background noise. Precoding can reduce crosstalk in the downstream from the access node to the customer premises equipment significantly if an accurate estimate of the in

  12. Accurate formulas for the penalty caused by interferometric crosstalk

    DEFF Research Database (Denmark)

    Rasmussen, Christian Jørgen; Liu, Fenghai; Jeppesen, Palle

    2000-01-01

    New simple formulas for the penalty caused by interferometric crosstalk in PIN receiver systems and optically preamplified receiver systems are presented. They are more accurate than existing formulas.......New simple formulas for the penalty caused by interferometric crosstalk in PIN receiver systems and optically preamplified receiver systems are presented. They are more accurate than existing formulas....

  13. Optimal Backlight Modulation With Crosstalk Control in Stereoscopic Display

    DEFF Research Database (Denmark)

    Jiao, Liangbao; Shu, Xiao; Cheng, Yong;

    2014-01-01

    Crosstalk between the left-eye and right-eye images is one of the main artifacts affecting the visual quality of stereoscopic liquid crystal display (LCD) systems. In this paper, a novel technique, called Optimal Backlight Modulation (OBM), is proposed to reduce crosstalk by taking the advantage ...

  14. The cellular decision between apoptosis and autophagy

    Directory of Open Access Journals (Sweden)

    Yong-Jun Fan

    2013-03-01

    Full Text Available Apoptosis and autophagy are important molecular processes that maintain organismal and cellular homeostasis, respectively. While apoptosis fulfills its role through dismantling damaged or unwanted cells, autophagy maintains cellular homeostasis through recycling selective intracellular organelles and molecules. Yet in some conditions, autophagy can lead to cell death. Apoptosis and autophagy can be stimulated by the same stresses. Emerging evidence indicates an interplay between the core proteins in both pathways, which underlies the molecular mechanism of the crosstalk between apoptosis and autophagy. This review summarizes recent literature on molecules that regulate both the apoptotic and autophagic processes.

  15. Functional maturation of growth hormone cells in the anterior pituitary gland of the fetus

    OpenAIRE

    Nogami, Haruo; Hisano, Setsuji

    2008-01-01

    Recent studies have disclosed the molecular mechanisms responsible for the phenotype determination of the anterior pituitary cell types. However, as far as growth hormone (GH) cells are concerned, particular extra-cellular cues are required for the initiation of GH and GH-releasing hormone (GHRH)-receptor gene production in addition to the expression of the cell type specific transcription factor, pit-1. The glucocorticoids play a principal role in the functional maturation of nascent GH cell...

  16. Cellular Signaling in the Bovine Antral Follicles

    OpenAIRE

    Juan F. Vásquez - Cano; Martha Olivera - A.

    2010-01-01

    Antral follicle development in the ovary of female cattle is the product of a complex of endocrine, paracrine and autocrine relationships. The interactions of the pituitary gonadotropins over granulosa and theca cells prepare the follicle to produce estradiol and for the final stages of maturation of the oocyte and its potencial ovulation or atresia inside subordinate follicles. It is a dynamic event where cellular signaling patterns changes sequentiallyand quickly at different stages of foll...

  17. Diagnosis of pituitary microadenoma : significance of T2-weighted MR image

    International Nuclear Information System (INIS)

    To evaluate the significance of T2-weighted MR imaging(T2WI) in the diagnosis of pituitary microadenoma. We retrospectively evaluated the MR imaging findings of 30 cases of pituitary microadenoma. Diagnosis was made on the basis of surgery, serum hormonal level, and the presence of mass lesion on MR (T1WI and T2WI), and conventional as well as dynamic contrast enhanced T1WI images were obtained. In each MR sequence, signal intensity and detectability of the tumor were evaluated. We also determined whether diagnosis was possible on both T1WI and T2WI. In eight cases, histopathologic findings (cellularity, fibrosis, and cystic change) were correlated with T2 signal intensity of the tumor. T2WI, T1WI, and dynamic and conventional enhanced T1WI detected the tumor in 21 cases (70%), 21 cases (70%), 28 cases (93.3%), and 22 cases (73.3%), respectively. On T2WI, pituitary microadenomas showed a high signal in 18 cases (60%), an iso-signal in nine (30%), and a low signal in three (10%) compared with normal pituitary gland. In 20 cases (66.7%), diagnosis of pituitary microadenoma was possible on both T1WI and T2WI, but in one case, the tumor was detected only on T2WI. Three cases with fibrosis, as seen on histopathologic examination showed an iso or low signal on T2WI. T2WI is useful in the diagnosis of pituitary microadenoma Decreased signal intensity on T2WI may suggest fibrosis

  18. Metalloproteinases ADAM12 and MMP-14 are associated with cavernous sinus invasion in pituitary adenomas.

    Science.gov (United States)

    Wang, Junwen; Voellger, Benjamin; Benzel, Julia; Schlomann, Uwe; Nimsky, Christopher; Bartsch, Jörg W; Carl, Barbara

    2016-09-15

    Invasion of tumor cells critically depends on cell-cell or cell-extracellular matrix interactions. Enzymes capable of modulating these interactions belong to the proteinase families of ADAM (a disintegrin and metalloprotease) and MMP (matrix metalloprotease) proteins. Our objective is to examine their expression levels and evaluate the relationship between expression levels and cavernous sinus invasion in pituitary adenomas. Tissue samples from 35 patients with pituitary adenomas were analyzed. Quantitative real-time polymerase chain reaction (qPCR) was employed to assess mRNA expression levels for ADAM and MMP genes. Protein levels were examined using immunohistochemistry and Western Blot. Correlation analyses between expression levels and clinical parameters were performed. By silencing ADAM12 and MMP-14 with siRNA in a mouse pituitary adenoma cell line (TtT/GF), their cellular effects were investigated. In our study, nine women and 26 men were included, with a mean age of 53.1 years (range 15-84 years) at the time of surgery. There were 19 cases with cavernous sinus invasion. The proteins ADAM12 and MMP-14 were significantly up-regulated in invasive adenomas compared to noninvasive adenomas. Both human isoforms of ADAM12 (ADAM12L and ADAM12s) were involved in tumor invasion; moreover, ADAM12L was found to correlate positively with Ki-67 proliferation index in pituitary adenomas. In TtT/GF pituitary adenoma cells, silencing of ADAM12 and MMP-14 significantly inhibited cell invasion and migration, respectively, whereas only silencing of ADAM12 suppressed cell proliferation. We conclude that ADAM12 and MMP-14 are associated with cavernous sinus invasion in pituitary adenomas, which qualifies these proteins in diagnosis and therapy. PMID:27144841

  19. Numerical Simulations of Intraband Crosstalk in Optical Cross Connect

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    All optical network based on wavelength division multiplexing transmission system with optical cross connect (OXC) is an essential approach for optical commumications.Crosstalk introduced by OXC (specially large scale one) is a key limiting factor for its capacity. Optical signal passing through a typical OXC is analyzed in this paper, followed by description of the generation and effect of intraband crosstalk.The power penalties induced by intraband crosstalk versus the number of multiplexed wavelengths M and the number of input fibers N have been given by numerical simulations. The results show that the coherent crosstalk is the most critical limitation on OXC and depends more closely on the number of multiplexed wavelengths M than the number of input fibers N. Crosstalk is suppressed by doubly filtering, fixing optimum decision-threshold and appropriately choosing the number of multiplexed wavelengths M.

  20. Cellular automata

    CERN Document Server

    Codd, E F

    1968-01-01

    Cellular Automata presents the fundamental principles of homogeneous cellular systems. This book discusses the possibility of biochemical computers with self-reproducing capability.Organized into eight chapters, this book begins with an overview of some theorems dealing with conditions under which universal computation and construction can be exhibited in cellular spaces. This text then presents a design for a machine embedded in a cellular space or a machine that can compute all computable functions and construct a replica of itself in any accessible and sufficiently large region of t

  1. Auxin-Oxylipin Crosstalk: Relationship of Antagonists

    Institute of Scientific and Technical Information of China (English)

    Maik Hoffmann; Mathias Hentrich; Stephan Pollmann

    2011-01-01

    Phytohormones regulate a wide array of developmental processes throughout the life cycle of plants. Herein, the various plant hormones may interact additively, synergistically, or antagonistically. By their cooperation they create a delicate regulatory network whose net output largely depends on the action of specific phytohormone combinations rather than on the independent activities of separate hormones. While most classical studies of plant hormonal control have focused mainly on the action of single hormones or on the synergistic interaction of hormones in regulating various developmental processes, recent work is beginning to shed light on the crosstalk of nominally antagonistic plant hormones, such as gibberellins and auxins with oxylipins or abscisic acid. In this review, we summarize our current understanding of how two of the first sight antagonistic plant hormones, i.e. auxins and oxylipins,interact in controlling plant responses and development.

  2. Mortality in patients with pituitary disease.

    LENUS (Irish Health Repository)

    Sherlock, Mark

    2010-06-01

    Pituitary disease is associated with increased mortality predominantly due to vascular disease. Control of cortisol secretion and GH hypersecretion (and cardiovascular risk factor reduction) is key in the reduction of mortality in patients with Cushing\\'s disease and acromegaly, retrospectively. For patients with acromegaly, the role of IGF-I is less clear-cut. Confounding pituitary hormone deficiencies such as gonadotropins and particularly ACTH deficiency (with higher doses of hydrocortisone replacement) may have a detrimental effect on outcome in patients with pituitary disease. Pituitary radiotherapy is a further factor that has been associated with increased mortality (particularly cerebrovascular). Although standardized mortality ratios in pituitary disease are falling due to improved treatment, mortality for many conditions are still elevated above that of the general population, and therefore further measures are needed. Craniopharyngioma patients have a particularly increased risk of mortality as a result of the tumor itself and treatment to control tumor growth; this is a key area for future research in order to optimize the outcome for these patients.

  3. Concomitant pituitary adenoma and Rathke's cleft cyst

    International Nuclear Information System (INIS)

    We reviewed the clinical, radiological and surgical findings in patients with both pituitary adenoma and Rathke's cleft cyst. We retrospectively selected patients with both lesions from the 374 patients in whom a sellar/juxtasellar lesion was detected on MRI at 1.5 tesla. All patients received intravenous contrast medium. Concomitant pituitary adenoma and Rathke's cleft cyst were found in eight patients (2.1 %). The frequency of the combination was 3.5 % of pituitary adenomas and 11 % of Rathke's cleft cysts. Symptoms were always due to the adenoma, secreting adrenocorticotrophin in two patients and growth hormone in six. The adenoma was larger in five patients, and the cyst in three. The cysts gave variable signal. The adenoma was adjacent to the cyst in seven patients, and enclosed it in the other patient. As a result of experience with MRI, concomitant pituitary adenoma and Rathke's cleft cyst are now known not to be as rare as thought previously. When a nonenhancing cyst-like structure is demonstrated in a patient with pituitary adenoma, the possibility of a coexisting Rathke's cleft cyst should be considered. (orig.)

  4. Terra MODIS Band 27 Electronic Crosstalk Effect and Its Removal

    Science.gov (United States)

    Sun, Junqiang; Xiong, Xiaoxiong; Madhavan, Sriharsha; Wenny, Brian

    2012-01-01

    The MODerate-resolution Imaging Spectroradiometer (MODIS) is one of the primary instruments in the NASA Earth Observing System (EOS). The first MODIS instrument was launched in December, 1999 on-board the Terra spacecraft. MODIS has 36 bands, covering a wavelength range from 0.4 micron to 14.4 micron. MODIS band 27 (6.72 micron) is a water vapor band, which is designed to be insensitive to Earth surface features. In recent Earth View (EV) images of Terra band 27, surface feature contamination is clearly seen and striping has become very pronounced. In this paper, it is shown that band 27 is impacted by electronic crosstalk from bands 28-30. An algorithm using a linear approximation is developed to correct the crosstalk effect. The crosstalk coefficients are derived from Terra MODIS lunar observations. They show that the crosstalk is strongly detector dependent and the crosstalk pattern has changed dramatically since launch. The crosstalk contributions are positive to the instrument response of band 27 early in the mission but became negative and much larger in magnitude at later stages of the mission for most detectors of the band. The algorithm is applied to both Black Body (BB) calibration and MODIS L1B products. With the crosstalk effect removed, the calibration coefficients of Terra MODIS band 27 derived from the BB show that the detector differences become smaller. With the algorithm applied to MODIS L1B products, the Earth surface features are significantly removed and the striping is substantially reduced in the images of the band. The approach developed in this report for removal of the electronic crosstalk effect can be applied to other MODIS bands if similar crosstalk behaviors occur.

  5. Radiotherapy for pituitary adenomas: an endocrinologist`s perspective

    Energy Technology Data Exchange (ETDEWEB)

    O`Halloran, D.J.; Shalet, S.M. [Christie Hospital and Holt Radium Inst., Manchester (United Kingdom)

    1996-10-01

    A brief review is given of the clinical management of patients with pituitary adenomas such as prolactinomas, adenomasin acromegoly and Leushin`s disease, and non-functioning pituitary adenomas. In particular the complications of radiotherapy are explored. (UK).

  6. Polymicrobial Pituitary Abscess Predominately Involving Escherichia coli in the Setting of an Apoplectic Pituitary Prolactinoma

    Directory of Open Access Journals (Sweden)

    Norman Beatty

    2016-01-01

    Full Text Available Pituitary abscess is a rare intracranial infection that can be life-threatening if not appropriately diagnosed and treated upon presentation. The most common presenting symptoms include headache, anterior pituitary hypofunction, and visual field disturbances. Brain imaging with either computed tomography or magnetic resonance imaging usually reveals intra- or suprasellar lesion(s. Diagnosis is typically confirmed intra- or postoperatively when pathological analysis is done. Clinicians should immediately start empiric antibiotics and request a neurosurgical consult when pituitary abscess is suspected. Escherichia coli (E. coli causing intracranial infections are not well understood and are uncommon in adults. We present an interesting case of an immunocompetent male with a history of hypogonadism presenting with worsening headache and acute right eye vision loss. He was found to have a polymicrobial pituitary abscess predominantly involving E.   coli in addition to Actinomyces odontolyticus and Prevotella melaninogenica in the setting of an apoplectic pituitary prolactinoma. The definitive etiology of this infection was not determined but an odontogenic process was suspected. A chronic third molar eruption and impaction in close proximity to the pituitary gland likely led to contiguous spread of opportunistic oral microorganisms allowing for a polymicrobial pituitary abscess formation.

  7. Polymicrobial Pituitary Abscess Predominately Involving Escherichia coli in the Setting of an Apoplectic Pituitary Prolactinoma.

    Science.gov (United States)

    Beatty, Norman; Medina-Garcia, Luis; Al Mohajer, Mayar; Zangeneh, Tirdad T

    2016-01-01

    Pituitary abscess is a rare intracranial infection that can be life-threatening if not appropriately diagnosed and treated upon presentation. The most common presenting symptoms include headache, anterior pituitary hypofunction, and visual field disturbances. Brain imaging with either computed tomography or magnetic resonance imaging usually reveals intra- or suprasellar lesion(s). Diagnosis is typically confirmed intra- or postoperatively when pathological analysis is done. Clinicians should immediately start empiric antibiotics and request a neurosurgical consult when pituitary abscess is suspected. Escherichia coli (E. coli) causing intracranial infections are not well understood and are uncommon in adults. We present an interesting case of an immunocompetent male with a history of hypogonadism presenting with worsening headache and acute right eye vision loss. He was found to have a polymicrobial pituitary abscess predominantly involving E.   coli in addition to Actinomyces odontolyticus and Prevotella melaninogenica in the setting of an apoplectic pituitary prolactinoma. The definitive etiology of this infection was not determined but an odontogenic process was suspected. A chronic third molar eruption and impaction in close proximity to the pituitary gland likely led to contiguous spread of opportunistic oral microorganisms allowing for a polymicrobial pituitary abscess formation. PMID:27006841

  8. The pituitary growth hormone cell in space

    Science.gov (United States)

    Hymer, Wesley C.; Grindeland, R.

    1989-01-01

    Growth hormone (GH), produced and secreted from specialized cells in the pituitary gland, controls the metabolism of protein, fat, and carbohydrate. It is also probably involved in the regulation of proper function of bone, muscle and immune systems. The behavior of the GH cell system was studied by flying either isolated pituitary cells or live rats. In the latter case, pituitary GH cells are prepared on return to earth and then either transplanted into hypophysectomized rats or placed into cell culture so that function of GH cells in-vivo vs. in-vitro can be compared. The results from three flights to date (STS-8, 1983; SL-3, 1985; Cosmos 1887, 1987) established that the ability of GH cells to release hormone, on return to earth, is compromised. The mechanism(s) responsible for this attenuation response is unknown. However, the data are sufficiently positive to indicate that the nature of the secretory defect resides directly within the GH cells.

  9. Patient reported outcome in posttraumatic pituitary deficiency

    DEFF Research Database (Denmark)

    Klose, Marianne; Stochholm, Kirstine; Janukonyté, Jurgita;

    2015-01-01

    with traumatic brain injury (TBI) in relation to deficiencies identified upon pituitary assessment. DESIGN AND METHODS: We conducted a nationwide population-based cohort study. Participants were Danish patients with a head trauma diagnosis recorded in the Danish Board of Health diagnostic code registry...... were observed with declining total testosterone concentrations (men), but not free testosterone concentrations or any other hormone concentrations. Total testosterone was not independently related to impaired QoL and fatigue, after adjustment for demographics, and treatment with antidiabetics, opioids......, antidepressants, and anticonvulsants. CONCLUSIONS: Only a very limited relationship between pituitary hormone deficiencies and QoL/fatigue was demonstrated. Due to the dominating influence of concurrent comorbidities, pituitary deficiencies were not independently related to QoL/fatigue. Causality is still to be...

  10. MRI of pituitary adenomas in acromegaly

    International Nuclear Information System (INIS)

    Adenomas causing acromegaly represent at least a quarter of pituitary adenomas. We studied 12 patients presenting with active acromegaly due to a pituitary adenoma with a 1.5 T superconductive MRI unit. All had T1-weighted sagittal and coronal sections before and after Gd-DTPA; six had coronal T2-weighted images. Surgical correlation was obtained in seven patients. Histologically, there were eight growth hormone (GH)-secreting and three mixed [GH and prolactin (PRL) secreting[ adenomas, and one secreting GH, PRL and follicle-stimulating hormone. Macroadenomas (10) were more frequent than microadenomas (2). No correlation was found between serum GH and tumour size. There were nine adenomas in the lateral part of the pituitary gland; seven showed lateral or infrasellar invasion. Homogeneous, isointense signal on T1-and T2-weighted images was observed in six cases. Heterogeneous adenomas had cystic or necrotic components. (orig.). With 5 figs., 3 tabs

  11. Computed tomography of the pituitary gland

    International Nuclear Information System (INIS)

    This book is written entirely to include the imaging of the pituitary gland by computed tomography (CT). The first three chapters illustrated technical aspects of scanning, anatomic depiction of the gland by CT, and the use of dynamic CT scanning for detecting and displaying abnormalities. The chapters discuss and illustrate various types of pathologic processes in and around the pituitary gland. One short but very helpful chapter demonstrates potential pitfalls due to the combination of anatomic variants and the geometry of CT sections. Some illustrations of disease processed are depicted by magnetic resonance imaging. All major types of pituitary diseases are illustrated. Lists of readily available English-language references are available. A small subject index is provided at the end of the book in which the illustrations are identified by use of a special numeric front

  12. Contemporary issues in the evaluation and management of pituitary adenomas.

    Science.gov (United States)

    Pekic, S; Stojanovic, M; Popovic, V

    2015-12-01

    Pituitary adenomas are common benign monoclonal neoplasms accounting for about 15% of intracranial neoplasms. Data from postmortem studies and imaging studies suggest that 1 of 5 individuals in the general population may have pituitary adenoma. Some pituitary adenomas (mainly microadenomas which have a diameter of less than 1 cm) are exceedingly common and are incidentally diagnosed on magnetic resonance imaging (MRI) performed for an unrelated reason (headache, vertigo, head trauma). Most microadenomas remain clinically occult and stable in size, without an increase in tumor cells and without local mass effects. However, some pituitary adenomas grow slowly, enlarge by expansion and become demarcated from normal pituitary (macroadenomas have a diameter greater than 1 cm). They may be clinically silent or secrete anterior pituitary hormones in excess such as prolactin, growth hormone (GH), or adrenocorticotropic hormone (ACTH) causing diseases like prolactinoma, acromegaly, Cushing's disease or rarely thyroid-stimulating hormone (TSH) or gonadotropins (LH, FSH). The incidence of the various subtypes of pituitary adenoma varies but the most common is prolactinoma. Clinically non-functioning pituitary adenomas (NFPAs), which do not secrete hormones often cause local mass symptoms and represent one-third of pituitary adenomas. Given the high prevalence of pituitary adenomas and their heterogeneity (different tumor subtypes), it is critical that clinicians have a thorough understanding of the potential abnormalities in pituitary function and prognostic factors for behavior of pituitary adenomas in order to timely implement specific treatment modalities. Regarding pathogenesis of these tumors genetics, epigenetics and signaling pathways are the focus of current research yet our understanding of pituitary tumorigenesis remains incomplete. Although several genes and signaling pathways have been identified as important factors in the development of pituitary tumors, current

  13. Pituitary tumors in patients with MEN1 syndrome

    OpenAIRE

    Syro, Luis V.; Scheithauer, Bernd W.; Kalman Kovacs; Toledo, Rodrigo A.; Francisco J. Londoño; Ortiz, Leon D.; Fabio Rotondo; Eva Horvath; Humberto Uribe

    2012-01-01

    We briefly review the characteristics of pituitary tumors associated with multiple endocrine neoplasia type 1. Multiple endocrine neoplasia type 1 is an autosomal-dominant disorder most commonly characterized by tumors of the pituitary, parathyroid, endocrine-gastrointestinal tract, and pancreas. A MEDLINE search for all available publications regarding multiple endocrine neoplasia type 1 and pituitary adenomas was undertaken. The prevalence of pituitary tumors in multiple endocrine neoplasia...

  14. The pituitary - Aging and spaceflown rats

    Science.gov (United States)

    Hymer, W. C.; Grindeland, R. E.

    1991-01-01

    Decrements in growth hormone (GH) release we observed in two spaceflight experiments and four tail-suspended rat studies mimic age-associated changes in the mammalian pituitary GH system seen by Meites and others. The spaceflight data suggest that formation of high molecular weight bioactive disulfide-linked aggregates of the 20 and 22K monomeric GH forms may be reduced in microgravity, thereby, reducing target tissue activity. Correlative studies to confirm spaceflight as a model for pituitary GH system aging should include: (1) investigation of mechanisms of intracellular hormone packaging, (2) consequences to biological activity of the hormone molecule, and (3) study of intracellular microtubule dynamics.

  15. MR of pituitary micro-adenomas

    International Nuclear Information System (INIS)

    Most of the time, rationales to look for pituitary micro-adenomas are based on endocrinal disorder. MRI is often helpful to confirm diagnosis. It gives information about micro-adenomas size and localisation. If conventional sequence are inadequate, a dynamic sequence has then to be performed after Gadolinium injection. Any disorder observed from the pituitary gland must be correlated with the clinical observation and results from biochemistry analysis. False positive happens quite open because of gland morphological variation, incidentalomas and partial volumes. MRI offers the possibility to follow-up treated micro-adenomas evolution especially to detect recurrence. (author)

  16. MR findings in three pituitary abscesses. Case reports

    International Nuclear Information System (INIS)

    We present MR findings in 3 surgically proved cases of pituitary abscess. All lesions were seen as a sellar cystic mass with a thin rim of enhancement. In addition, the pituitary stalk was thickened in 2 cases in which central diabetes insipidus developed. These findings may be suggestive of pituitary abscess. (orig.)

  17. Pathobiology and oncogenesis of pituitary corticotroph adenomas in dogs

    NARCIS (Netherlands)

    Hanson, J.M.

    2007-01-01

    Pituitary-dependent hyperadrenocorticism (PDH) or Cushing's disease is a common endocrinopathy in the elderly dog caused by a pituitary adrenocorticotrophic hormone (ACTH) producing tumor (corticotroph adenoma) of unknown pathogenesis. Surgical removal of the pituitary tumor is applied as routine tr

  18. Recurrent oculomotor palsy due to haemorrhage in pituitary adenoma.

    OpenAIRE

    Mohanty, S.

    1980-01-01

    Haemorrhage in pituitary adenoma is an unusual cause of recurrent oculomotor palsy. Three episodes of right oculomotor palsy are reported from a patient having haemorrhage in pituitary adenoma. Early operation and decompression of haemorrhagic pituitary adenoma should be performed so that vision may be preserved and recovery of oculomotor palsy be assured.

  19. Gene expression profiling analysis of MENX-associated rat pituitary adenomas contributes to understand molecular mechanisms of human pituitary adenomas

    OpenAIRE

    ZHANG, HONGZHI; XU, CHUAN; SUN, NINGYANG; ZHOU, YINTING; Yu, Xiaofei; Yan, Xue; ZHANG, QIUJUAN

    2015-01-01

    The present study aimed to screen potential genes associated with pituitary adenomas to obtain further understanding with regard to the pathogenesis of pituitary adenomas. The microarray GSE23207 dataset, containing 16 pituitary adenoma samples from multiple endocrine neoplasia syndrome-associated rats and 5 normal pituitary tissue samples, was downloaded from Gene Expression Omnibus. The Linear Models for Microarray Data package was used to identify the differentially-expressed genes (DEGs) ...

  20. Interferometric crosstalk suppression using polarization multiplexing technique and an SOA

    OpenAIRE

    LIU, FENGHAI; Xueyan, Zheng; Pedersen, Rune Johan Skullerud; Jeppesen, Palle

    2000-01-01

    Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA.

  1. Detection of Crosstalk Faults in Field Programmable Gate Arrays (FPGA)

    Science.gov (United States)

    Das, N.; Roy, P.; Rahaman, H.

    2015-09-01

    In this work, a Built-in-Self-Test (BIST) technique has been proposed to detect crosstalk faults in FPGA and run time congestion and to provide the crosstalk aware router for FPGA. The proposed BIST circuits require less overhead as compared to earlier techniques. The proposed detector can detect any logic hazard or delay due to crosstalk. A technique has also been proposed to avoid the crosstalk by routing the path in such a way that no interference occurs between the interconnects. The proposed router has achieved better utilization of routing resource to determine the net as compared to the earlier works. The proposed scheme is simulated in MATLAB and verified using Xilinx ISE tools and Modelsim 6.0. The router is implemented by using class provided by JBits for Xilinx, Vertex-II FPGA. It has been found that the results are quite encouraging.

  2. PCB 126 toxicity is modulated by cross-talk between caveolae and Nrf2 signaling

    Energy Technology Data Exchange (ETDEWEB)

    Petriello, Michael C. [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Han, Sung Gu [University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Food Science and Biotechnology of Animal Resources, College of Animal Bioscience and Technology, Konkuk University, Seoul 143-701 (Korea, Republic of); Newsome, Bradley J. [University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Chemistry, College of Arts and Sciences, University of Kentucky, Lexington, KY 40506 (United States); Hennig, Bernhard [Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, KY 40536 (United States); University of Kentucky Superfund Research Center, Lexington, KY 40536 (United States); Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, KY 40506 (United States)

    2014-06-01

    Environmental toxicants such as polychlorinated biphenyls (PCBs) have been implicated in the promotion of multiple inflammatory disorders including cardiovascular disease, but information regarding mechanisms of toxicity and cross-talk between relevant cell signaling pathways is lacking. To examine the hypothesis that cross-talk between membrane domains called caveolae and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathways alters PCB-induced inflammation, caveolin-1 was silenced in vascular endothelial cells, resulting in a decreased PCB-induced inflammatory response. Cav-1 silencing (siRNA treatment) also increased levels of Nrf2-ARE transcriptional binding, resulting in higher mRNA levels of the antioxidant genes glutathione s-transferase and NADPH dehydrogenase quinone-1 in both vehicle and PCB-treated systems. Along with this upregulated antioxidant response, Cav-1 siRNA treated cells exhibited decreased mRNA levels of the Nrf2 inhibitory protein Keap1 in both vehicle and PCB-treated samples. Silencing Cav-1 also decreased protein levels of Nrf2 inhibitory proteins Keap1 and Fyn kinase, especially in PCB-treated cells. Further, endothelial cells from wildtype and Cav-1 −/− mice were isolated and treated with PCB to better elucidate the role of functional caveolae in PCB-induced endothelial inflammation. Cav-1 −/− endothelial cells were protected from PCB-induced cellular dysfunction as evidenced by decreased vascular cell adhesion molecule (VCAM-1) protein induction. Compared to wildtype cells, Cav-1 −/− endothelial cells also allowed for a more effective antioxidant response, as observed by higher levels of the antioxidant genes. These data demonstrate novel cross-talk mechanisms between Cav-1 and Nrf2 and implicate the reduction of Cav-1 as a protective mechanism for PCB-induced cellular dysfunction and inflammation. - Highlights: • Reduction of caveolin-1 protein protects against polychlorinated biphenyl toxicity. • Decreasing

  3. PCB 126 toxicity is modulated by cross-talk between caveolae and Nrf2 signaling

    International Nuclear Information System (INIS)

    Environmental toxicants such as polychlorinated biphenyls (PCBs) have been implicated in the promotion of multiple inflammatory disorders including cardiovascular disease, but information regarding mechanisms of toxicity and cross-talk between relevant cell signaling pathways is lacking. To examine the hypothesis that cross-talk between membrane domains called caveolae and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathways alters PCB-induced inflammation, caveolin-1 was silenced in vascular endothelial cells, resulting in a decreased PCB-induced inflammatory response. Cav-1 silencing (siRNA treatment) also increased levels of Nrf2-ARE transcriptional binding, resulting in higher mRNA levels of the antioxidant genes glutathione s-transferase and NADPH dehydrogenase quinone-1 in both vehicle and PCB-treated systems. Along with this upregulated antioxidant response, Cav-1 siRNA treated cells exhibited decreased mRNA levels of the Nrf2 inhibitory protein Keap1 in both vehicle and PCB-treated samples. Silencing Cav-1 also decreased protein levels of Nrf2 inhibitory proteins Keap1 and Fyn kinase, especially in PCB-treated cells. Further, endothelial cells from wildtype and Cav-1 −/− mice were isolated and treated with PCB to better elucidate the role of functional caveolae in PCB-induced endothelial inflammation. Cav-1 −/− endothelial cells were protected from PCB-induced cellular dysfunction as evidenced by decreased vascular cell adhesion molecule (VCAM-1) protein induction. Compared to wildtype cells, Cav-1 −/− endothelial cells also allowed for a more effective antioxidant response, as observed by higher levels of the antioxidant genes. These data demonstrate novel cross-talk mechanisms between Cav-1 and Nrf2 and implicate the reduction of Cav-1 as a protective mechanism for PCB-induced cellular dysfunction and inflammation. - Highlights: • Reduction of caveolin-1 protein protects against polychlorinated biphenyl toxicity. • Decreasing

  4. Experimental investigation of inter-core crosstalk tolerance of MIMO-OFDM/OQAM radio over multicore fiber system.

    Science.gov (United States)

    He, Jiale; Li, Borui; Deng, Lei; Tang, Ming; Gan, Lin; Fu, Songnian; Shum, Perry Ping; Liu, Deming

    2016-06-13

    In this paper, the feasibility of space division multiplexing for optical wireless fronthaul systems is experimentally demonstrated by implementing high speed MIMO-OFDM/OQAM radio signals over 20km 7-core fiber and 0.4m wireless link. Moreover, the impact of optical inter-core crosstalk in multicore fibers on the proposed MIMO-OFDM/OQAM radio over fiber system is experimentally evaluated in both SISO and MIMO configurations for comparison. The experimental results show that the inter-core crosstalk tolerance of the proposed radio over fiber system can be relaxed to -10 dB by using the proposed MIMO-OFDM/OQAM processing. These results could guide high density multicore fiber design to support a large number of antenna modules and a higher density of radio-access points for potential applications in 5G cellular system. PMID:27410359

  5. Interferometric crosstalk suppression using polarization multiplexing technique and an SOA

    DEFF Research Database (Denmark)

    Liu, Fenghai; Xueyan, Zheng; Pedersen, Rune Johan Skullerud;

    2000-01-01

    Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA.......Interferometric crosstalk can be greatly suppressed at 10Gb/s and 20Gb/s by using a gain saturated SOA and a polarization multiplexing technique that eliminates impairments like waveform and extinction ratio degradation from the SOA....

  6. Elimination of flux-transformer crosstalk in multichannel SQUID magnetometers

    OpenAIRE

    Brake, ter, O.; Fleuren, F.H.; Ulfman, J.A.; Flokstra, J.

    1986-01-01

    Multichannel SQUID magnetometers are being developed for signal-field mapping in biomagnetic experiments. A problem that becomes more serious as the number of channels is increased is the crosstalk caused by the mutual inductances between the individual sensing coils. A simple and effective method for eliminating this crosstalk is presented in this Paper. The method is based on a rearrangement of the feedback loops which causes the flux-transformer circuits to become currentless. The feasibil...

  7. Elimination of flux-transformer crosstalk in multichannel SQUID magnetometers

    Science.gov (United States)

    ter Brake, H. J. M.; Fleuren, F. H.; Ulfrnan, J. A.; Flokstra, J.

    Multichannel SQUID magnetometers are being developed for signal-field mapping in biomagnetic experiments. A problem that becomes more serious as the number of channels is increased is the crosstalk caused by the mutual inductances between the individual sensing coils. A simple and effective method for eliminating this crosstalk is presented in this Paper. The method is based on a rearrangement of the feedback loops which causes the flux-transformer circuits to become currentless. The feasibility of the method is verified experimentally.

  8. Polymicrobial Pituitary Abscess Predominately Involving Escherichia coli in the Setting of an Apoplectic Pituitary Prolactinoma

    OpenAIRE

    Norman Beatty; Luis Medina-Garcia; Mayar Al Mohajer; Zangeneh, Tirdad T.

    2016-01-01

    Pituitary abscess is a rare intracranial infection that can be life-threatening if not appropriately diagnosed and treated upon presentation. The most common presenting symptoms include headache, anterior pituitary hypofunction, and visual field disturbances. Brain imaging with either computed tomography or magnetic resonance imaging usually reveals intra- or suprasellar lesion(s). Diagnosis is typically confirmed intra- or postoperatively when pathological analysis is done. Clinicians should...

  9. Radioimmunoassay of pituitary and hypothalamic hormones

    International Nuclear Information System (INIS)

    Radioimunoassay (RIA) systems have been developed to quantitate virtually every hormone available in pure form. This exquisitely sensitive technique has revolutionized the fields of endocrine physiology and clinical endocrinology. Bioassay techniques which have been employed for many years are not sufficiently sensitive to measure accurately all the anterior pituitary hormones in plasma; the development of RIAs in biologic fluids and tissues has permitted studies which have greatly expanded our knowledge of the factors involved in an anterior pituitary hormone synthesis, metabolism, and action. A chapter on the general principles of RIAs for anterior pituitary hormones would have the disadvantage of being repetitive, several excellent reviews on this topic being already available in the literature. In view of these points, this chapter, in addition to quoting many papers from the literature describing the technical procedures of pituitary hormone RIAs in several animal species, will focus on some aspects thought to be of peculiar interest. More space will be given to the second part of the chapter, on the RIA detection of hypophysiotropic neurohormones. This is an expanding field on endocrinology, particularly after the recent recognition of corticotropin-releasing factor (CRF) and growth hormone-releasing hormone (GHRH). Besides a description of the general problems related to the assay of hypophysiotropic peptides and a critical assessment of available techniques, the significance of determinations of these peptides in brain areas or biologic fluid as an index of neuronal function will be considered

  10. Pituitary tumors following fallout radiation exposure

    International Nuclear Information System (INIS)

    Two pituitary tumors were diagnosed in a small population of Marshallese accidentally exposed to radioactive fallout in 1954. Endocrinologic findings in the exposed population, are reported and the possible relation of the tumors to radiation exposure and thyroid disease is discussed

  11. Pituitary tumor secondary to primary hypothyroidism

    International Nuclear Information System (INIS)

    A 20-year-old female patient had primary hypothyroidism with a chief complaint of hypermenorrhea. She was found to have sellar dilation on cranial plain x-rays and was suspected of having pituitary tumor on cranial CT. When she was given levothyroxine, the thyroid function returned to normal and CT revealed disappearance of the tumor. (Namekawa, K.)

  12. HYPONATREMIA AFTER TRANSSPHENIODAL SURGERY OF PITUITARY ADENOMA

    Institute of Scientific and Technical Information of China (English)

    陶蔚; 任祖渊; 苏长保; 王任直; 杨义; 马文斌

    2003-01-01

    Objective. To clarify the frequency, presentation, associated factors, treatment and outcome of hy-ponatremia after transsphenoidal surgery of pituitary adenomas.Methods. Retrospectively reviewed the database of 183 patients who underwent transsphenoidal surgeryof pituitary adenomas between January 1999 and June 2000 in our department.Result.s. 38.8% (71/183) had postoperative hyponatremia. Among them, 59.2% (42/71) appeared onthe 4th to 7th day postoperatively. 59.2% (42/71) presented with nausea, vomiting, headache, dizzi-ness, confusion and weakness. Hyponatremia was related to age, tumor size and adenoma type, but notrelated to sex and degree of resection. Treatment consisted of salt replacement and mild fluid restrictionin 4 patients and salt and fluid replacement in 67 patients. Hyponatremia resolved within 16 days in allthe patients.Conclusions. Hyponatremia often appeared about 7 days after transsphenoidal surgery of pituitary ade-nomas, especially in elderly and patients with macroadenomas and huge pituitary adenomas. The principleof treatment was salt and fluid replacement.

  13. Pituitary Stone or Calcified Pituitary Tumor? Three Cases and Literature Review

    Science.gov (United States)

    Chentli, Farida; Safer-Tabi, Amel

    2015-01-01

    Introduction: Pituitary stone or pituitary calculus is a scientific enigma characterized by a large calcification in the pituitary sella. It can be discovered incidentally or in a patient with endocrine and/or neurological problems. Its mechanism is not understood. In this article, we described three patients harboring a large pituitary calcification. Case Presentation: The first case was observed in a 27-year-old woman who consulted for secondary amenorrhea. The second case concerned a woman who consulted for infertility, and the third one was observed in an 11-year and nine-month-old girl who was sent to our department for short stature. Clinical examination was normal in both adults. The pediatric case had dwarfism with lack of pubertal development. Hormonal assessment showed hyperprolactinemia in both women and thyrotroph and somatotroph deficits in the child. Radiologic exploration discovered pituitary calcifications measuring 10, 11, and 45 mm without any cystic or solid mass. Conclusions: Radiological findings pleaded for a pituitary stone, but calcified adenomas in women, and calcified craniopharyngioma in the pediatric case could not be excluded, as our three patients were not operated on. PMID:26401144

  14. Stroma-epithelium crosstalk in prostate cancer

    Institute of Scientific and Technical Information of China (English)

    Yi-Nong Niu; Shu-Jie Xia

    2009-01-01

    The critical role played by stroma-epithelium crosstalk in carcinogenesis and progression of prostate cancer has been increasingly recognized.These interactions are mediated by a variety of paracrine factors secreted by cancer cells and/or stromal cells.In human prostate cancer,reactive stroma is characterized by an increase in myofibroblasts and a corresponding amplification of extracellular matrix production and angiogenesis.Permanent genetic mutations have been reported in stromal cells as well as in turnout cells.Transforming growth factor-β,vascular endothelial growth factor,platelet-derived growth factor and fibroblast growth factor signalling pathways are involved in the process of angiogenesis,whereas hepatocyte growth factor,insulin-like growth factor-1,epidermal growth factor,CXC12 and Interleukin-6 play active roles in the progression,androgen-independent conversion and distal metastasis of prostate cancer.Some soluble factors have reciprocal interactions with androgens and the androgen receptor (AR),and can even activate AR in the absence of the androgen ligand.In this article,we review the complex interactions between cancer cells and the surrounding microenvironment,and discuss the potential therapeutic targets in the stromal compartment of prostate cancer.

  15. MRI study of pituitary in girls with central precocious puberty

    International Nuclear Information System (INIS)

    Objective: To study the shape, size and signal intensity of pituitary gland in girls aged 3-10 year old with central precocious puberty. Methods: MRI data of pituitary glands in 40 girls aged 3-10 years old with central precocious puberty were selected. The shape, height and the appearances of pituitary glands were measured and observed on sagittal T1WI. Results: Quantitative data about size, shape and single intensity changes of pituitary glands in central precocious puberty were obtained in two groups, including girls aged from 3-5 and 5-10. The convex pituitary gland were 85.0% in former group. The height of pituitary gland were 6.1±0.2mm (former group) and 6.4± 0.4mm (latter one) respectively. The width of pituitary stalk was 1.93±0.50mm. The posterior pituitary gland demonstrated high signal intensity in all cases. Conclusion: Obvious changes of the size and shape of pituitary glands were found in central precocious puberty of girls aged from 3-10. The pituitary glands manifested physiologic hypertrophy with more convex in central precocious puberty girls than in normal ones. The changes on MRI could reflect the function of hypothalamus-pituitary-gonadal axis. It is of important value and significance in the diagnosis of central precocious puberty. (authors)

  16. MRI evaluation of pituitary hyperplasia due to primary hypothyroidism

    International Nuclear Information System (INIS)

    Objective: To analyze the MRI manifestations of the pituitary hyperplasia due to primary hypothyroidism and to improve the differential diagnosis of secondary pituitary hyperplasia and pituitary tumors. Methods: The MRI findings of pituitary hyperplasia in 10 documented primary hypothyroidism patients (male 3, female 7; age range: 9-15 years) were reviewed. The pulse sequences using a 1.0T MR scanner included coronal and sagittal T1W, coronal T2W and coronal contrast-enhanced T1W in all patients. Results: The pituitary gland was markedly enlarged with mean height of 15.5 mm (11-23 mm). Central bulging of pituitary gland was seen in all 10 patients with mild displacement of the infundibulum in 3 and sellar enlargement in 5. All glands had homogeneous MR signal intensities and contrast enhancement. Conclusion: Pituitary hyperplasia due to primary hypothyroidism has characteristic MR features of central bulging with homogeneous signal intensities and contrast enhancement. (authors)

  17. Pituitary abscess: a case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Apostolos K A Karagiannis

    2016-06-01

    Full Text Available Pituitary abscess is a rare life-threating entity that is usually misdiagnosed as a pituitary tumor with a definite diagnosis only made postoperatively. Over the last several decades, advances in healthcare have led to a significant decrease in morbidity and mortality due to pituitary abscess. We report a case of a 34-year-old woman who was admitted to our department for investigation of a pituitary mass and with symptoms of pituitary dysfunction, headaches and impaired vision. During her admission, she developed meningitis-like symptoms and was treated with antibiotics. She eventually underwent transsphenoidal surgery for excision of the pituitary mass. A significant amount of pus was evident intraoperatively; however, no pathogen was isolated. Six months later, the patient was well and had full recovery of the anterior pituitary function. Her menses returned, and she was only on treatment with desmopressin for diabetes insipidus that developed postoperatively.

  18. The crosstalk between EGF, IGF, and Insulin cell signaling pathways - computational and experimental analysis

    Directory of Open Access Journals (Sweden)

    Przytycka Teresa M

    2009-09-01

    Full Text Available Abstract Background Cellular response to external stimuli requires propagation of corresponding signals through molecular signaling pathways. However, signaling pathways are not isolated information highways, but rather interact in a number of ways forming sophisticated signaling networks. Since defects in signaling pathways are associated with many serious diseases, understanding of the crosstalk between them is fundamental for designing molecularly targeted therapy. Unfortunately, we still lack technology that would allow high throughput detailed measurement of activity of individual signaling molecules and their interactions. This necessitates developing methods to prioritize selection of the molecules such that measuring their activity would be most informative for understanding the crosstalk. Furthermore, absence of the reaction coefficients necessary for detailed modeling of signal propagation raises the question whether simple parameter-free models could provide useful information about such pathways. Results We study the combined signaling network of three major pro-survival signaling pathways: Epidermal Growth Factor Receptor (EGFR, Insulin-like Growth Factor-1 Receptor (IGF-1R, and Insulin Receptor (IR. Our study involves static analysis and dynamic modeling of this network, as well as an experimental verification of the model by measuring the response of selected signaling molecules to differential stimulation of EGF, IGF and insulin receptors. We introduced two novel measures of the importance of a node in the context of such crosstalk. Based on these measures several molecules, namely Erk1/2, Akt1, Jnk, p70S6K, were selected for monitoring in the network simulation and for experimental studies. Our simulation method relies on the Boolean network model combined with stochastic propagation of the signal. Most (although not all trends suggested by the simulations have been confirmed by experiments. Conclusion The simple model

  19. Signaling cross-talk between TGF-β/BMP and other path-ways

    Institute of Scientific and Technical Information of China (English)

    Xing Guo; Xiao-Fan Wang

    2009-01-01

    Transforming growth factor-beta(TGF-β)/bone morphogenic protein(BMP)signaling is involved in the vast majority of cellular processes and is fundamentally important during the entire life of alI metazoans.Deregulation of TGF-β/BMP activity almost invariably leads to developmental defects and/or diseases.including cancer.The proper functioning of the TGF-β/BMP pathway depends on its constitutive and extensive communication with other signaling pathways,leading to synergistic or antagonistic effects and eventually desirable biological outcomes.The nature of such signaling cross-talk iS overwhelmingly complex and highly context-dependent.Here we review the difierent modes of cross-talk between TGF-β/BMP and the signaling pathways of Mitogen-activated protein kinase,phosphatidyIinositoI-3 kinase/Akt,Wnt,Hedgehog,Notch,and the interleukin/interferon-gamma/tumor necrosis factor-alpha cytokines,with an emphasis on the underlying molecular mechanisms.

  20. Cellular Automata

    OpenAIRE

    Bagnoli, Franco

    1998-01-01

    An introduction to cellular automata (both deterministic and probabilistic) with examples. Definition of deterministic automata, dynamical properties, damage spreading and Lyapunov exponents; probabilistic automata and Markov processes, nonequilibrium phase transitions, directed percolation, diffusion; simulation techniques, mean field. Investigation themes: life, epidemics, forest fires, percolation, modeling of ecosystems and speciation. They represent my notes for the school "Dynamical Mod...

  1. Contribution of crosstalk to the uncertainty of electrostatic actuator calibrations.

    Science.gov (United States)

    Shams, Qamar A; Soto, Hector L; Zuckerwar, Allan J

    2009-09-01

    Crosstalk in electrostatic actuator calibrations is defined as the ratio of the microphone response to the actuator excitation voltage at a given frequency with the actuator polarization voltage turned off to the response, at the excitation frequency, with the polarization voltage turned on. It consequently contributes to the uncertainty of electrostatic actuator calibrations. Two sources of crosstalk are analyzed: the first attributed to the stray capacitance between the actuator electrode and the microphone backplate, and the second to the ground resistance appearing as a common element in the actuator excitation and microphone input loops. Measurements conducted on 1/4, 1/2, and 1 in. air condenser microphones reveal that the crosstalk has no frequency dependence up to the membrane resonance frequency and that the level of crosstalk lies at about -60 dB for all three microphones-conclusions that are consistent with theory. The measurements support the stray capacitance model. The contribution of crosstalk to the measurement standard uncertainty of an electrostatic actuator calibration is therewith 0.01 dB. PMID:19739723

  2. Cavernous sinus extension of pituitary tumors

    International Nuclear Information System (INIS)

    This paper investigates the capability of ultrafast dynamic MR imaging to delineate cavernous sinus extension of pituitary region tumors. The dynamic imaging technique captures a temporal phase when Gd-DTPA-laden blood is in the vascular spaces, but the tumors have not yet enhanced and they appear as filling defects. This phase lasts less than 10 seconds. This information was helpful in the interpretation of seven equivocal cases (five positive, two negative), four of which were confirmed surgically. Dynamic imaging did not add to the determination of the pre- and postcontrast T1SE images in the remaining 15 patients. Dynamic imaging can be useful for delineating cavernous sinus extension of pituitary and perisellar tumors in cases in which the pre- and postgadolinium T1SE images are equivocal

  3. Preoperative volume determination for pituitary adenoma

    Science.gov (United States)

    Zukic, Dženan; Egger, Jan; Bauer, Miriam H. A.; Kuhnt, Daniela; Carl, Barbara; Freisleben, Bernd; Kolb, Andreas; Nimsky, Christopher

    2011-03-01

    The most common sellar lesion is the pituitary adenoma, and sellar tumors are approximately 10-15% of all intracranial neoplasms. Manual slice-by-slice segmentation takes quite some time that can be reduced by using the appropriate algorithms. In this contribution, we present a segmentation method for pituitary adenoma. The method is based on an algorithm that we have applied recently to segmenting glioblastoma multiforme. A modification of this scheme is used for adenoma segmentation that is much harder to perform, due to lack of contrast-enhanced boundaries. In our experimental evaluation, neurosurgeons performed manual slice-by-slice segmentation of ten magnetic resonance imaging (MRI) cases. The segmentations were compared to the segmentation results of the proposed method using the Dice Similarity Coefficient (DSC). The average DSC for all datasets was 75.92%+/-7.24%. A manual segmentation took about four minutes and our algorithm required about one second.

  4. Pituitary carcinoma with different hormone expressions

    OpenAIRE

    Lu, Tao; Wang, Ren-Zhi; Zhao-hui ZHU; Ding-rong ZHONG

    2015-01-01

    Objective To introduce the experience of diagnosing and treating one case of pituitary carcinoma with distinct hormone expressions in primary and metastatic lesions and to improve understanding of this disease.  Methods Retrospective study was performed to analyze the clinical manifestations, imaging characteristics, histopathologic findings, and treatment information of the patient. Immunohistochemical staining was done to both primary and metastatic lesions.  Results The patient pre...

  5. Pituitary apoplexy presenting as myocardial infarction

    Directory of Open Access Journals (Sweden)

    Vishal Gupta

    2014-01-01

    Full Text Available We describe a male patient who presented with sudden onset severe headache and right sided ptosis that was diagnosed to be secondary to pituitary apoplexy on the background of diabetes mellitus. This was complicated by left ventricular failure and acute coronary syndrome. The case highlights the importance of considering hypocortisolism/hypopituitarism as an important and rare precipitant of an acute coronary event as occurred in the case.

  6. The result of radiotherapy for pituitary adenoma

    International Nuclear Information System (INIS)

    To evaluate the prognostic factors for disease-free survival and long-term results of radiotherapy for pituitary adenoma. The study involved a retrospective review of outcome in a series of 27 patients with pituitary adenoma, between 1984 and 1995 at Paik hospital. The study included 20 patients treated with surgery and postoperative radiotherapy and 7 with radiotherapy alone. The patients were followed for 12-146 months (median: 97 months). Seventeen were men and 10 were women. The numbers of functioning and non-functioning pituitary adenoma were 22 and 5 respectively and those of microadenoma and macroadenoma were 4 and 23 respectively. The radiation doses of 5040-5580cGy(median: 5040cGy) were delivered over 5-7 weeks, using 4MV LINAC. The prognostic factors were analyzed by log-rank test. For radiation therapy alone, the 5 YSR was 100% and progression free survival rate was 85.8%. The tumor was controlled in 6/7 (85.8%). For surgery and postoperative radiotherapy , the 5YSR, progression free survival rate and local control rate were 95%, 84.8%, and 89.5% respectively. The parameters of tumor size, hormone secretion, radiation dose, radiotherapy field size were evaluated in a uni- and multivariate analysis and all the factors were not statistically significant (P>0.05). Eleven of 12 (92%) with visual field defect experienced normalization or improvement, and 5 for 7 evaluable patients with hyperprolactinoma achieved normalization in 4 and decrement in 5 patients. Only 2 patients developed mild degree of panhypopituitarism. The radiotherapy appears to be effective in controlling clinical symptoms and signs resulting from pituitary adenoma. Local control rate with radiotherapy alone or with surgery and postoperative radiotherapy was comparable. There was a trend toward high recurrence rate in patients with nonfunctioning or prolactin secreting tumor and larger radiation field sizes. (author)

  7. Assessment of crosstalks between the Snf1 kinase complex and sphingolipid metabolism in S. cerevisiae via systems biology approaches.

    Science.gov (United States)

    Borklu Yucel, Esra; Ulgen, Kutlu O

    2013-11-01

    Sphingolipids are essential building blocks of the plasma membranes and are highly bioactive in the regulation of diverse cellular functions and pathological processes, a fact which renders the sphingolipid metabolism an important research area. In this study, a computational framework was recruited for the reconstruction of a functional interaction network for sphingolipid metabolism in Baker's yeast, SSN. Gene Ontology (GO) annotations were integrated with functional interaction data of the BIOGRID database and the reconstructed protein interaction network was subjected to topological and descriptive analyses. SSN was of a scale-free nature, following a power law model with γ=1.41. Prominent processes of SSN revealed that the reconstructed network encapsulated the involvement of sphingolipid metabolism in vital cellular processes such as energy homeostasis, cell growth and/or death and synthesis of building blocks. To investigate the potential of SSN for predicting signal transduction pathways regulating and/or being regulated by sphingolipid biosynthesis in yeast, a case study involving the S. cerevisiae counterpart of AMP-activated protein kinase, the Snf1 kinase complex, was conducted. The mutant strain lacking the catalytic α subunit, snf1Δ/snf1Δ, had elevated inositol phosphorylceramide and mannosyl-inositol phosphorylceramide levels, and decreased mannosyl-diinositol phosphorylceramide levels compared to the wild type strain, revealing that Snf1p has a regulatory role in the sphingolipid metabolism. Transcriptome data belonging to that strain available in the literature were mapped onto SSN and the correlated SSN was further investigated to evaluate the possible crosstalk machineries where sphingolipids and Snf1p function in coordination, in other words the crosstalk points between sphingolipid-mediated and Snf1 kinase signalling. The subsequent investigation of the discovered candidate crosstalk processes by performing sensitivity experiments imply a

  8. Advances in trans-sphenoidal pituitary surgery.

    Science.gov (United States)

    Solari, D; Cavallo, L M; De Angelis, M; Villa, A; Somma, T; Esposito, F; Del Basso De Caro, M; Cappabianca, P

    2012-12-01

    Pituitary surgery is a continuous evolving speciality of the neurosurgeons' armamentarium, requiring precise anatomical knowledge, technical skills and integrated appreciation of the pituitary pathophysiology. Actually, it could be considered the result of a close cooperation between different specialists, i.e. the ophthalmologist, the neuroradiologist, the endocrinologist, the neurosurgeon, the pathologist, etc. In this teamwork environment each member plays his own role, offering his contribute to the final result; every effort is performed to provide patients with the best possible procedure, individually measured. The endoscopic pituitary surgery performed by means of a transsphenoidal approach perfectly fits this scenario, being though advocated as the result of an evolutionary process rather than a revolutionary one. The "pure" endoscopic transsphenoidal surgery - consisting of a whole procedure performed with the endoscope alone and without the use of any transsphenoidal retractor - offers some advantages due to the endoscope itself: a superior close-up view of the relevant anatomy, very important at the tumor/gland interface and an enlarged working angle are provided with an increased panoramic vision inside the surgical area. Results in terms of mass removal, relief of clinical symptoms, cure of the underlying disease and complication rate are similar to those reported in the major microsurgical series but patient compliance is by far better. PMID:23123578

  9. Mechanisms of mitochondria and autophagy crosstalk

    OpenAIRE

    Rambold, Angelika S.; Lippincott-Schwartz, Jennifer

    2011-01-01

    Autophagy is a cellular survival pathway that recycles intracellular components to compensate for nutrient depletion and ensures the appropriate degradation of organelles. Mitochondrial number and health are regulated by mitophagy, a process by which excessive or damaged mitochondria are subjected to autophagic degradation. Autophagy is thus a key determinant for mitochondrial health and proper cell function. Mitophagic malfunction has been recently proposed to contribute to progressive neuro...

  10. Effect of Crosstalk on Permutation in Optical Multistage Interconnection Networks

    CERN Document Server

    Kaur, Er Sandeep; Aggarwal, Er Deepak

    2010-01-01

    Optical MINs hold great promise and have advantages over their electronic networks.they also hold their own challenges. More research has been done on Electronic Multistage Interconnection Networks, (EMINs) but these days optical communication is a good networking choice to meet the increasing demands of high-performance computing communication applications for high bandwidth applications. The electronic Multistage Interconnection Networks (EMINs) and the Optical Multistage Interconnection Networks (OMINs) have many similarities, but there are some fundamental differences between them such as the optical-loss during switching and the crosstalk problem in the optical switches. To reduce the negative effect of crosstalk, various approaches which apply the concept of dilation in either the space or time domain have been proposed. With the space domain approach, extra SEs are used to ensure that at most one input and one output of every SE will be used at any given time. For an Optical network without crosstalk, ...

  11. Integrated SQUID sensors for low cross-talk multichannel systems

    International Nuclear Information System (INIS)

    We present a fully integrated dc-SQUID magnetometer based on niobium technology including a new feedback coil design. In respect to a standard SQUID design, such a feedback-coil design was optimized in order to reduce the mutual inductance with the neighbours and to increase the coupling with the pick-up coil of the SQUID itself. In such a way, it is possible to reduce cross-talks due to both feedback coil and wires. Experimental results about the characterization of the device and the crosstalk measurements are reported. The measurements have been performed in liquid helium using a low noise readout electronics specifically designed for large multichannel SQUID based instrumentations. The experimental data have shown a substantial reduction of cross-talk between neighbouring sensors

  12. Integrated SQUID sensors for low cross-talk multichannel systems

    Science.gov (United States)

    Granata, C.; Vettoliere, A.; Luiso, M.; Russo, M.

    2006-06-01

    We present a fully integrated dc-SQUID magnetometer based on niobium technology including a new feedback coil design. In respect to a standard SQUID design, such a feedback-coil design was optimized in order to reduce the mutual inductance with the neighbours and to increase the coupling with the pick-up coil of the SQUID itself. In such a way, it is possible to reduce cross-talks due to both feedback coil and wires. Experimental results about the characterization of the device and the crosstalk measurements are reported. The measurements have been performed in liquid helium using a low noise readout electronics specifically designed for large multichannel SQUID based instrumentations. The experimental data have shown a substantial reduction of cross-talk between neighbouring sensors.

  13. Theoretical analysis of crosstalk in near-infrared topography

    Science.gov (United States)

    Okada, E.; Okui, N.

    2006-09-01

    Crosstalk between changes in concentration of oxy-and deoxy-haemoglobin calculated by modified Lambert-Beer law in near-infrared topography is theoretically investigated. The change in intensity detected with source-detector pairs on the scalp caused by global or focal ahsorption change in the brain is predicted by Monte Carlo simulation. The topographic images of changes in oxy- and deoxy-haemoglobin are obtained from the changes in intensity detected with source-detector pairs on the scalp. The crosstalk depends on the relative position of the focal absorption change to source-detector pairs. The crosstalk is minimised when the focal absorption change is located below a measurement point that is the midpoint between a source and a detector.

  14. Crosstalk Cancellation for a Simultaneous Phase Shifting Interferometer

    Science.gov (United States)

    Olczak, Eugene (Inventor)

    2014-01-01

    A method of minimizing fringe print-through in a phase-shifting interferometer, includes the steps of: (a) determining multiple transfer functions of pixels in the phase-shifting interferometer; (b) computing a crosstalk term for each transfer function; and (c) displaying, to a user, a phase-difference map using the crosstalk terms computed in step (b). Determining a transfer function in step (a) includes measuring intensities of a reference beam and a test beam at the pixels, and measuring an optical path difference between the reference beam and the test beam at the pixels. Computing crosstalk terms in step (b) includes computing an N-dimensional vector, where N corresponds to the number of transfer functions, and the N-dimensional vector is obtained by minimizing a variance of a modulation function in phase shifted images.

  15. Crosstalk between tumor suppressors p53 and PKCδ: Execution of the intrinsic apoptotic pathways.

    Science.gov (United States)

    Dashzeveg, Nurmaa; Yoshida, Kiyotsugu

    2016-07-28

    p53 and PKCδ are tumor suppressors that execute apoptotic mechanisms in response to various cellular stresses. p53 is a transcription factor that is frequently mutated in human cancers; it regulates apoptosis in transcription-dependent and -independent ways in response to genotoxic stresses. PKCδ is a serine/threonine protein kinase and mutated in human cancers. Available evidence shows that PKCδ activates p53 by direct and/or indirect mechanisms. Moreover, PKCδ is also implicated in the transcriptional regulation of p53 in response to DNA damage. Recent findings demonstrated that p53, in turn, binds onto the PKCδ promoter and induces its expression upon DNA damage to facilitate apoptosis. Both p53 and PKCδ are associated with the apoptotic mechanisms in the mitochondria by regulating Bcl-2 family proteins to provide mitochondrial outer membrane permeabilization. This review discusses the crosstalk between p53 and PKCδ in the context of apoptotic cell death and cancer therapy. PMID:27130668

  16. Managing complexity: Dealing with systemic crosstalk in bovine physiology.

    Science.gov (United States)

    Bradford, Barry J; Yuan, Kai; Ylioja, Caroline

    2016-06-01

    Dairy producers rely heavily on advisors with deep expertise in nutrition, reproduction, and health. However, a shift is occurring, driven both by farm size and by advances in biology. Larger dairy businesses can investigate management options with a degree of precision never before possible; simultaneously, the lines between the metabolic, immune, and reproductive systems are becoming blurred. For example, new research has revealed a surprising role for immune cells in regulating metabolism and documented the nutrient requirements of the immune system. The gut epithelium has garnered new attention as a tissue that actively manages the commensal microbiome, entrains the responses of the neonatal immune system, and provides a barrier limiting movement of molecules from the gut lumen. New hormone discoveries have added adipose tissue, bone, and muscle to the list of endocrine organs. Finally, nutrients are now seen not only as substrates and cofactors, but also as signals that can alter cellular function. What does all of this mean for the dairy industry? Consultants are increasingly reaching across disciplinary boundaries to best support the physiology of the cow. However, research is needed to translate proof-of-principle findings into applications in cattle. Key unanswered questions include the degree to which roles of the hindgut in monogastrics translate to ruminants, and whether some host-microbe crosstalk also occurs in the rumen; whether hormone release by storage organs during a catabolic state affects reproductive function; and the degree to which immunostimulation by dietary signals enhances or disrupts health and productivity. It is critical to address these questions with multiple approaches. Mechanistic studies provide a nuanced understanding of signal interactions, but large-scale commercial studies are needed to evaluate effects on multiple production outcomes in the environment of interest, and meta-analyses best integrate findings into a cohesive

  17. Pituitary oncocytoma presenting as Cushing′s disease

    Directory of Open Access Journals (Sweden)

    M K Garg

    2013-01-01

    Full Text Available A 19-year-old girl presented with classical features of Cushing′s syndrome. Endocrinal evaluation was consistent with pituitary source of ACTH; but imaging showed normal pituitary. Bilateral inferior petrosal sinus sampling confirmed the diagnosis. A successful remission was achieved after adenomectomy by transphenoidal route. Histopathological examination was consistent with pituitary oncocytoma and immunohistochemistry was positive for synaptophysin, chromogranin, neuron specific enolase, S-100, ACTH, prolactin, and GH.

  18. The prevalence of hyperprolactinemia in non-functioning pituitary macroadenomas

    OpenAIRE

    Zhang, Fangfang; Huang, Yinxing; Ding, Chenyu; Huang, Guoliang; Wang, Shousen

    2015-01-01

    Objective: The prevalence of hyperprolactinemia in non-functioning pituitary macroadenomas (NFPMAs) is not well known, and hyperprolactinemia caused by a NFPMA is currently associated with diagnostic uncertainty. Thus, the aim of this study was to evaluate the prevalence of hyperprolactinemia in NFPMAs. Methods: A meta-analysis of all existing articles in PubMed was conducted. The search string was designed as “(non-functioning pituitary tumor OR non-functioning pituitary tumor OR non-functio...

  19. Accidently Discovered Postpartum Pituitary Apoplexy after Epidural Anesthesia

    OpenAIRE

    Rafik Sedra

    2014-01-01

    Anesthetic consideration of obstetric patients with pituitary disorders is an important topic to deal with. Few cases were reported with accidently discovered pituitary tumor complications especially in the postpartum period. A 26 years old primigravida lady with 39 weeks gestational period was reported to have severe headache and sudden loss of conscious after normal vaginal delivery with lumbar epidural anesthesia. Accidently discovered pituitary adenoma was proved after neurology, endocrin...

  20. Magnetic resonance imaging of normal pituitary gland

    International Nuclear Information System (INIS)

    Magnetic resonance imaging (MRI) is a suitable procedure for diagnosing such midline-positioned lesions as pituitary adenomas. To differentiate them from microadenomas fifty-seven cases (9 - 74 years old, 29 men and 28 women), including 50 patients without any sellar or parasellar diseases and seven normal volunteers, were studied in order to clarify the MR findings of the shape, height, and signal intensity of the normal pituitary gland, especially at the median sagittal section. The height of a normal pituitary gland varied from 2 to 9 mm (mean: 5.7 mm); the upper surface of the gland was convex in 19.3 %, flat in 49.1 %, and concave in 31.6 %. The mean height of the gland in women in their twenties was 7.5 mm, and the upper convex shape appeared exclusively in women of the second to fourth decades. Nine intrasellar pituitary adenomas (PRL-secreting: 4, GH-secreting: 4, ACTH-secreting: 1), all verified by surgery, were diagnosed using a resistive MR system. The heights of the gland in these cases were from 7 to 15 mm (mean: 11.3 mm); the upper surface was convex in 7 cases. A localized bulging of the upper surface of the gland and a localized depression of the sellar floor were depicted on the coronal and sagittal sections in most cases. Although the GH- and ACTH-secreting adenoma cases showed homogeneous intrasellar contents, in all the PRL-secreting adenoma cases a low-signal-intensity area was detected in the IR images. The mean T1 values of the intrasellar content of the normal volunteers, the PRL-, GH-, and ACTH-secreting adenoma cases, were 367, 416, 355, and 411 ms respectively. However, in the PRL-secreting adenoma cases, the mean T1 value of the areas showing a low signal intensity on IR images was 455 ms; this was a significant prolongation in comparison with that of a normal pituitary gland. (J.P.N.)

  1. Techniques for Characterizing Filters for Sensor Optical Cross-Talk

    OpenAIRE

    Murgai, Vijay; Cartland, Robert

    2013-01-01

    Interference filters assembled in ‘butcher-block’ arrays are used close to focal plane arrays for spectral definition in sensors such as VIIRS. Ideally only light incident on a particular filter above a detector element which is within the specified band will reach the detector. Optical cross-talk is in-band or out-of-band light incident on an adjacent filter or adjacent region of the same filter reaching the detector. Out-of-band optical cross-talk results in spectral and spatial ‘impurit...

  2. A Dual Decomposition Approach to Partial Crosstalk Cancelation in a Multiuser DMT-xDSL Environment

    Directory of Open Access Journals (Sweden)

    Verlinden Jan

    2007-01-01

    Full Text Available In modern DSL systems, far-end crosstalk is a major source of performance degradation. Crosstalk cancelation schemes have been proposed to mitigate the effect of crosstalk. However, the complexity of crosstalk cancelation grows with the square of the number of lines in the binder. Fortunately, most of the crosstalk originates from a limited number of lines and, for DMT-based xDSL systems, on a limited number of tones. As a result, a fraction of the complexity of full crosstalk cancelation suffices to cancel most of the crosstalk. The challenge is then to determine which crosstalk to cancel on which tones, given a complexity constraint. This paper presents an algorithm based on a dual decomposition to optimally solve this problem. The proposed algorithm naturally incorporates rate constraints and the complexity of the algorithm compares favorably to a known resource allocation algorithm, where a multiuser extension is made to incorporate the rate constraints.

  3. [Leptomeningeal Dissemination in Patients with Pituitary Metastasis from Breast Cancer].

    Science.gov (United States)

    Hayashi, Nakamasa; Mitsuya, Koichi; Harada, Hideyuki; Watanabe, Junichiro; Nishimura, Tetsuo; Nakasu, Yoko

    2016-05-01

    Pituitary metastases are uncommon complications of systemic cancer and account for only 1% of pituitary lesions. Breast cancer is one of the most common tumors to metastasize to the pituitary gland. A multidisciplinary approach that calls for close collaboration among oncologists, neurosurgeons, radiologists, and endocrinologists is mandatory for diagnosis and treatment of pituitary metastasis. From 2002 through 2013, 6 patients with pituitary metastases were treated at Shizuoka Cancer Center Hospital. The patients' age at presentation ranged from 45 to 75 years(average 59 years). Five of 6 patients had symptoms: anterior pituitary insufficiency in 4, diabetes insipidus in 3, and visual deficits in 2 patients. Five patients had other metastases at the time of presentation. Local irradiation to the metastatic lesion was adopted in 4, and whole brain irradiation was in 2 patients. In all cases, local control was achieved after irradiation, however, the pituitary insufficiency did not recover. Two of 4 patients treated with local irradiation suffered from meningeal dissemination within 5 months after treatment, and died at 8 and 11 months after diagnosis of pituitary metastasis, respectively. The patients treated with whole brain irradiation had longer survival periods. Early diagnosis, endocrinological management, and radiation therapy improve the quality of life in patients suffering from pituitary metastasis. Whole brain irradiation may be favorable in order to prevent meningeal dissemination. PMID:27166841

  4. Aspergillosis of the sphenoid sinus simulating a pituitary tumor

    International Nuclear Information System (INIS)

    Sphenoidal aspergillosis is an unusual cause of sella turcica enlargement. Pituitary abscess secondary to Aspergillus had been reported. In the present case, a woman with sphenoid sinus aspergillosis mimiced a pituitary tumor. This patient survived her infection with intact pituitary function following a transsphenoidal approach. No postoperative amphotericine-B and 5-fluorocytosine were necessary. CT scan revealed a mass occupying the sphenoid sinus extending to the sella turcica. Factors that should alert the clinican to the presence of a sphenoidal and pituitary abscess in a patient with sella turcica enlargement are prior episodes of sinusitis, meningitis and immunosuppression and, as in the present case, hyperglycemia. (orig.)

  5. Accidently Discovered Postpartum Pituitary Apoplexy after Epidural Anesthesia

    Directory of Open Access Journals (Sweden)

    Rafik Sedra

    2014-11-01

    Full Text Available Anesthetic consideration of obstetric patients with pituitary disorders is an important topic to deal with. Few cases were reported with accidently discovered pituitary tumor complications especially in the postpartum period. A 26 years old primigravida lady with 39 weeks gestational period was reported to have severe headache and sudden loss of conscious after normal vaginal delivery with lumbar epidural anesthesia. Accidently discovered pituitary adenoma was proved after neurology, endocrine and ophthalmology consultations. Hence, undiagnosed pituitary adenomas should be taken in to consideration with unexplained postpartum generalized weakness and loss of conscious especially after exclusion of epidural anesthesia complications.

  6. MRI of the hypothalamic-pituitary axis in children

    Energy Technology Data Exchange (ETDEWEB)

    Argyropoulou, Maria I. [University of Ioannina, Department of Radiology, Medical School, Ioannina (Greece); Kiortsis, Dimitrios Nikiforos [University of Ioannina, Department of Physiology, Medical School, Ioannina (Greece)

    2005-11-01

    In childhood, the MR characteristics of the normal pituitary gland are well established. During the first 2 months of life the adenohypophysis demonstrates high signal. Pituitary gland height (PGH) decreases during the 1st year of life and then increases, reaching a plateau after puberty. The magnetization transfer ratio (MTR) increases in both sexes up to the age of 20 years. On dynamic contrast-enhanced studies, the posterior pituitary lobe enhances simultaneously with the straight sinus, and the adenohypophysis later, but within 30 s. In genetically determined dysfunctional states, the adenohypophysis may be normal, hypoplastic, or enlarged. Pituitary enlargement, observed in Prop 1 gene mutations, is characterized by a mass interposed between the anterior and posterior lobes. An ectopic posterior lobe (EPP), associated with a hypoplastic or absent pituitary stalk, may be observed in patients with hypopituitarism. Tumors of the hypothalamic-pituitary (HP) axis may be the origin of adenohypophyseal deficiencies. A small hypointense adenohypophysis is found in iron overload states and is often associated with hypogonadotrophic hypogonadism. Absence of the posterior lobe bright signal, with or without a thick pituitary stalk or a mass at any site from the median eminence to the posterior pituitary lobe, may be found in diabetes insipidus. Hydrocephalus, suprasellar arachnoid cysts, hypothalamic hamartomas and craniopharyngiomas may result in central precocious puberty (CPP). Increased PGH in girls with idiopathic CPP is useful for its differential diagnosis from premature thelarche (PT). Pituitary adenomas, observed mainly in adolescents, present the same MR characteristics as those in adults. (orig.)

  7. Crosstalk between nitric oxide and hypoxia-inducible factor signaling pathways: an update

    Directory of Open Access Journals (Sweden)

    Hendrickson MD

    2015-06-01

    Full Text Available Marina D Hendrickson, Robert O Poyton Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO, USA Abstract: Hypoxia-inducible factor-1 (HIF-1 is responsible for cellular adaptations to hypoxia. While oxygen (O2 negatively regulates its stability, many other factors affect HIF-1 stability and activity, including nitric oxide (NO. NO derived from l-arginine and nitrite (NO2– could nitrosylate or nitrate HIF-1 and multiple proteins involved in HIF-1 regulation, and can allow HIF-1 to escape normoxic degradation. In turn, HIF-1 can increase NO production through multiple mechanisms, including increased inducible nitric oxide synthase (iNOS expression and subunit 4-2 of cytochrome c oxidase (COX4-2 expression. There is therefore a high degree of crosstalk between HIF-1 and NO signaling. As such, many cellular responses to NO are mediated by HIF-1, and vice versa. This includes, but is not limited to, angiogenesis, apoptosis, senescence, and metabolic changes. These pathways all have important functions in normal physiology and when altered can contribute or, in some cases, lead to pathogenesis. Keywords: HIF, nitric oxide, Cco/NO mitochondrial signaling, ROS/RNS, cancer

  8. Caveolin-1 sensitizes rat pituitary adenoma GH3 cells to bromocriptine induced apoptosis

    Directory of Open Access Journals (Sweden)

    Huang Mu-Chiou

    2007-03-01

    Full Text Available Abstract Background Prolactinoma is the most frequent pituitary tumor in humans. The dopamine D2 receptor agonist bromocriptine has been widely used clinically to treat human breast tumor and prolactinoma through inhibition of hyperprolactinemia and induction of tumor cell apoptosis, respectively, but the molecular mechanism of bromocriptine induction of pituitary tumor apoptosis remains unclear. Caveolin-1 is a membrane-anchored protein enriched on caveolae, inverted flask-shaped invaginations on plasma membranes where signal transduction molecules are concentrated. Currently, caveolin-1 is thought to be a negative regulator of cellular proliferation and an enhancer of apoptosis by blocking signal transduction between cell surface membrane receptors and intracellular signaling protein cascades. Rat pituitary adenoma GH3 cells, which express endogenous caveolin-1, exhibit increased apoptosis and shrinkage after exposure to bromocriptine. Hence, the GH3 cell line is an ideal model for studying the molecular action of bromocriptine on prolactinoma. Results The expression of endogenous caveolin-1 in GH3 cells was elevated after bromocriptine treatment. Transiently expressed mouse recombinant caveolin-1 induced apoptosis in GH3 cells by enhancing the activity of caspase 8. Significantly, caveolin-1 induction of GH3 cell apoptosis was sensitized by the administration of bromocriptine. Phosphorylation of caveolin-1 at tyrosine 14 was enhanced after bromocriptine treatment, suggesting that bromocriptine-induced phosphorylation of caveolin-1 may contribute to sensitization of apoptosis in GH3 cells exposed to bromocriptine. Conclusion Our results reveal that caveolin-1 increases sensitivity for apoptosis induction in pituitary adenoma GH3 cells and may contribute to tumor shrinkage after clinical bromocriptine treatment.

  9. Pituitary Apoplexy Presenting as Isolated Third Cranial Nerve Palsy with Ptosis : Two Case Reports

    OpenAIRE

    Cho, Won-Jin; Joo, Sung-Pil; Kim, Tae-Sun; Seo, Bo-Ra

    2009-01-01

    Pituitary apoplexy is a clinical syndrome caused by an acute ischemic or hemorrhagic vascular accident involving a pituitary adenoma or an adjacent pituitary gland. Pituitary apoplexy may be associated with a variety of neurological and endocrinological signs and symptoms. However, isolated third cranial nerve palsy with ptosis as the presenting sign of pituitary apoplexy is very rare. We describe two cases of pituitary apoplexy presenting as sudden-onset unilateral ptosis and diplopia. In on...

  10. Cellular resilience.

    Science.gov (United States)

    Smirnova, Lena; Harris, Georgina; Leist, Marcel; Hartung, Thomas

    2015-01-01

    Cellular resilience describes the ability of a cell to cope with environmental changes such as toxicant exposure. If cellular metabolism does not collapse directly after the hit or end in programmed cell death, the ensuing stress responses promote a new homeostasis under stress. The processes of reverting "back to normal" and reversal of apoptosis ("anastasis") have been studied little at the cellular level. Cell types show astonishingly similar vulnerability to most toxicants, except for those that require a very specific target, metabolism or mechanism present only in specific cell types. The majority of chemicals triggers "general cytotoxicity" in any cell at similar concentrations. We hypothesize that cells differ less in their vulnerability to a given toxicant than in their resilience (coping with the "hit"). In many cases, cells do not return to the naive state after a toxic insult. The phenomena of "pre-conditioning", "tolerance" and "hormesis" describe this for low-dose exposures to toxicants that render the cell more resistant to subsequent hits. The defense and resilience programs include epigenetic changes that leave a "memory/scar" - an alteration as a consequence of the stress the cell has experienced. These memories might have long-term consequences, both positive (resistance) and negative, that contribute to chronic and delayed manifestations of hazard and, ultimately, disease. This article calls for more systematic analyses of how cells cope with toxic perturbations in the long-term after stressor withdrawal. A technical prerequisite for these are stable (organotypic) cultures and a characterization of stress response molecular networks. PMID:26536287

  11. DMPD: Innate immune responses: crosstalk of signaling and regulation of genetranscription. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16753195 Innate immune responses: crosstalk of signaling and regulation of genetran...l) (.csml) Show Innate immune responses: crosstalk of signaling and regulation of genetranscription. PubmedI...D 16753195 Title Innate immune responses: crosstalk of signaling and regulation o

  12. Very low crosstalk wavelength router construction using arrayed-waveguide grating multi/demultiplexers

    DEFF Research Database (Denmark)

    Liu, Fenghai; Pedersen, Rune Johan Skullerud; Jeppesen, Palle

    1999-01-01

    A very low crosstalk N × N wavelength router construction using 1 × N arrayed-waveguide grating multi/demultiplexers is described. A crosstalk level of <-53 dB has been measured in such an 8 × 8 wavelength router. Even a 64 × 64 wavelength router can be built with a large crosstalk margin....

  13. Proteolytic crosstalk in multi-protease networks

    Science.gov (United States)

    Ogle, Curtis T.; Mather, William H.

    2016-04-01

    Processive proteases, such as ClpXP in E. coli, are conserved enzyme assemblies that can recognize and rapidly degrade proteins. These proteases are used for a number of purposes, including degrading mistranslated proteins and controlling cellular stress response. However, proteolytic machinery within the cell is limited in capacity and can lead to a bottleneck in protein degradation, whereby many proteins compete (‘queue’) for proteolytic resources. Previous work has demonstrated that such queueing can lead to pronounced statistical relationships between different protein counts when proteins compete for a single common protease. However, real cells contain many different proteases, e.g. ClpXP, ClpAP, and Lon in E. coli, and it is not clear how competition between proteins for multiple classes of protease would influence the dynamics of cellular networks. In the present work, we theoretically demonstrate that a multi-protease proteolytic bottleneck can substantially couple the dynamics for both simple and complex (oscillatory) networks, even between substrates with substantially different affinities for protease. For these networks, queueing often leads to strong positive correlations between protein counts, and these correlations are strongest near the queueing theoretic point of balance. Furthermore, we find that the qualitative behavior of these networks depends on the relative size of the absolute affinity of substrate to protease compared to the cross affinity of substrate to protease, leading in certain regimes to priority queue statistics.

  14. Scaling and Pixel Crosstalk Considerations for CMOS Image Sensor

    Institute of Scientific and Technical Information of China (English)

    JIN Xiang-liang; CHEN Jie(member,IEEE); QIU Yu-lin

    2003-01-01

    With the scaling development of the minimum lithographic size,the scaling trend of CMOS imager pixel size and fill factor has been computed according to the Moore rule.When the CMOS minimum lithographic feature scales down to 0.35 μm,the CCD image pixel size is not so easy to be reduced and but the CMOS image pixel size benefits from the scaling minimum lithographic feature. However, when the CMOS technology is downscaled to or under 0.35 μm,the fabrication of CMOS image sensors will be limited by the standard CMOS process in both ways of shallow trench isolation and source/drain junction,which results in pixel crosstalk.The impact of the crosstalk on the active pixel CMOS image sensor is analyzed based on the technology scaling.Some suppressed crosstalk methods have been reviewed.The best way is that combining the advantages of CMOS and SOI technology to fabricate the image sensors will reduce the pixel crosstalk.

  15. Crosstalk in production modules of the Electromagnetic Endcap Calorimeter

    CERN Document Server

    Hubaut, Fabrice; Dekhissi, Bouchra; Derkaoui, Jamal Eddine; El-Kharrim, Abderrahman; Maaroufi, Fatiha

    2003-01-01

    Various types of crosstalk, measured with ATLAS-like electronics on three electromagnetic endcap calorimeter production modules at liquid argon temperature are reviewed. A comparison is made between the three modules results and previous measurements. The effect on the physics data is discussed.

  16. Multiple Pituitary Adenomas: A Systematic Review

    Science.gov (United States)

    Budan, Renata M.; Georgescu, Carmen E.

    2016-01-01

    PubMed, Scopus, and Web of Science Core Collection databases were systematically searched for studies reporting synchronous double or multiple pituitary adenomas (MPA), a rare clinical condition, with a vague pathogenesis. Multiple adenomas of the pituitary gland are referred to as morphologically and/or immunocytochemically distinct tumors that are frequently small-sized and hormonally non-functional, to account for the low detection rate. There is no general agreement on how to classify MPA, various criteria, such as tumor contiguity, immunoreactivity, and clonality analysis are being used. Among the component tumors, prolactin (PRL)-immunopositive adenomas are highly prevalent, albeit mute in the majority of cases. The most frequent clinical presentation of MPA is Cushing’s syndrome, given the fact that in more than 50% of reported cases at least one lesion stains for adrenocorticotrophic hormone (ACTH). Plurihormonal hyperactivity may be diagnosed in a patient with MPA when more than one tumor is clinically active (e.g., ACTH and PRL) or in cases with at least one composite tumor (e.g., GH and PRL), to complicate the clinical scenario. Specific challenges associated with MPA include high surgical failure rates, enforcing second-look surgery in certain cases, and difficult preoperative neuroradiological imaging evaluation, with an overall sensitivity of only 25% for magnetic resonance imaging to detect distinct multiple tumors. Alternatively, minor pituitary imaging abnormalities may raise suspicion, as these are not uncommon. Postoperative immunohistochemistry is mandatory and in conjunction to electron microscopy scanning and testing for transcription factors (i.e., Pit-1, T-pit, and SF-1) accurately define and classify the distinct cytodifferentiation of MPA. PMID:26869991

  17. IL-1α mediates cellular cross-talk in the airway epithelial mesenchymal trophic unit.

    Science.gov (United States)

    Hill, Alison R; Donaldson, Jessica E; Blume, Cornelia; Smithers, Natalie; Tezera, Liku; Tariq, Kamran; Dennison, Patrick; Rupani, Hitasha; Edwards, Matthew J; Howarth, Peter H; Grainge, Christopher; Davies, Donna E; Swindle, Emily J

    2016-01-01

    The bronchial epithelium and underlying fibroblasts form an epithelial mesenchymal trophic unit (EMTU) which controls the airway microenvironment. We hypothesized that cell-cell communication within the EMTU propagates and amplifies the innate immune response to respiratory viral infections. EMTU co-culture models incorporating polarized (16HBE14o-) or differentiated primary human bronchial epithelial cells (HBECs) and fibroblasts were challenged with double-stranded RNA (dsRNA) or rhinovirus. In the polarized EMTU model, dsRNA affected ionic but not macromolecular permeability or cell viability. Compared with epithelial monocultures, dsRNA-stimulated pro-inflammatory mediator release was synergistically enhanced in the basolateral compartment of the EMTU model, with the exception of IL-1α which was unaffected by the presence of fibroblasts. Blockade of IL-1 signaling with IL-1 receptor antagonist (IL-1Ra) completely abrogated dsRNA-induced basolateral release of mediators except CXCL10. Fibroblasts were the main responders to epithelial-derived IL-1 since exogenous IL-1α induced pro-inflammatory mediator release from fibroblast but not epithelial monocultures. Our findings were confirmed in a differentiated EMTU model where rhinovirus infection of primary HBECs and fibroblasts resulted in synergistic induction of basolateral IL-6 that was significantly abrogated by IL-1Ra. This study provides the first direct evidence of integrated IL-1 signaling within the EMTU to propagate inflammatory responses to viral infection. PMID:27583193

  18. The EBI2 signalling pathway plays a role in cellular crosstalk between astrocytes and macrophages.

    Science.gov (United States)

    Rutkowska, Aleksandra; O'Sullivan, Sinead A; Christen, Isabelle; Zhang, Juan; Sailer, Andreas W; Dev, Kumlesh K

    2016-01-01

    EBI2 is a G protein-coupled receptor activated by oxysterol 7α, 25-dihydroxycholesterol (7α25HC) and regulates T cell-dependant antibody response and B cell migration. We recently found EBI2 is expressed in human astrocytes, regulates intracellular signalling and modulates astrocyte migration. Here, we report that LPS treatment of mouse astrocytes alters mRNA levels of EBI2 and oxysterols suggesting that the EBI2 signalling pathway is sensitive to LPS-mediated immune challenge. We also find that conditioned media obtained from LPS-stimulated mouse astrocytes induces macrophage migration, which is inhibited by the EBI2 antagonist NIBR189. These results demonstrate a role for the EBI2 signalling pathway in astrocytes as a sensor for immune challenge and for communication with innate immune cells such as macrophages. PMID:27166278

  19. Hemostatic Disorders in Hormonally Active Pituitary Tumors.

    Science.gov (United States)

    Świątkowska-Stodulska, R; Babińska, A; Mital, A; Stodulski, D; Sworczak, K

    2015-10-01

    Endocrinopathies encompass heterogeneous diseases that can lead to hemostasis disorders at various stages over their clinical course. Normal hemostasis requires an equilibrium between the processes of coagulation and fibrinolysis, which depend on multiple activators and inhibitors. To date, the influence of various hormonal disorders on the hemostatic system has been assessed many times. The aim of this review was to analyze hemostasis abnormalities that occur in patients with hormonally active pituitary tumors: corticotropinoma, somatotropinoma, prolactinoma, gonadotropinoma and thyrotropinoma. Authors discuss studies that examined coagulation and hemostasis parameters among patients with these tumors, as well as analyze antithrombotic prophylaxis approach for endogenous hypercortisolemia subjects in particular. PMID:26285071

  20. Pituitary adenylate cyclase activating polypeptide and migraine

    DEFF Research Database (Denmark)

    Zagami, Alessandro S; Edvinsson, Lars; Goadsby, Peter J

    2014-01-01

    Pituitary adenylate cyclase activating peptide (PACAP) is found in human trigeminocervical complex and can trigger migraine. PACAP levels were measured using a sensitive radioimmunoassay. Stimulation of the superior sagittal sinus (SSS) in cat elevated PACAP levels in cranial blood. Patients with...... moderate or severe migraine headache had elevated PACAP in the external jugular vein during headache (n = 15), that was reduced 1 h after treatment with sumatriptan 6 mg (n = 11), and further reduced interictally (n = 9). The data suggest PACAP, or its receptors, are a promising target for migraine...

  1. Ptosis as the early manifestation of pituitary tumour.

    OpenAIRE

    Yen, M Y; Liu, J H; Jaw, S J

    1990-01-01

    Three patients who developed unilateral ptosis followed by partial third nerve palsy were found to have a pituitary tumour. The visual field defects were minimal and asymptomatic. Two patients had a chromophobe adenoma and one patient had a prolactinoma. The importance of recognising a pituitary tumour as the cause of acquired unilateral ptosis is emphasised.

  2. Xanthomatosis, pituitary gland, Magnetic Resonance Imaging, Sella turcica

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seok Jin; Kim, Eui Jong; Choi, Woo Seok [Dept. of Radiology, Kyunghee Medical Center, Kyunghee University College of Medicine, Seoul (Korea, Republic of); Park, Bong Jin [Dept. of Neurosurgery, Kyunghee Medical Center, Kyunghee University College of Medicine, Seoul (Korea, Republic of)

    2011-04-15

    Xanthomatous hypophysitis is a rare inflammatory disorder of the pituitary gland of unknown prevalence that causes pituitary dysfunction and a mass-like lesion. The authors report a case of 40-year-old man with a visual disturbance and a confirmed diagnosis of xanthomatous hypophysitis.

  3. Cushing's Syndrome From Pituitary Microadenoma and Pulmonary Nodules.

    Science.gov (United States)

    Tating, Dan Louie Renz P; Montevirgen, Natasha Denise S; Cajucom, Loyda

    2016-03-01

    Cushing's syndrome is a state of cortisol excess, possibly from a tumor in the pituitary gland, the adrenal gland, or an ectopic nonpituitary ACTH-secreting source. The first form, pituitary in origin, was originally described by Harvey Cushing, MD, and was labeled as Cushing's disease. Long-term therapy with glucocorticoids also can lead to iatrogenic Cushing's syndrome. PMID:26906124

  4. Regional cerebral blood flow studies in patients with pituitary tumours

    International Nuclear Information System (INIS)

    Regional cerebral blood flow (rCBF) was measured in seven patients with pituitary tumours, in one patient with a craniopharyngioma, and in one patient with an empty sella; rCB was increased only in patients with gonadotrophin deficiency. The preliminary conclusion is that this is perhaps related to the pituitary tumour itself, and in particular to the endocrine state. (author)

  5. Massive cerebral infarction as a feature of pituitary apoplexy.

    Directory of Open Access Journals (Sweden)

    Lath R

    2001-04-01

    Full Text Available A patient with pituitary apoplexy is reported who, in addition to the clinical features of apoplexy, developed a cerebral infarct secondary to compression of the internal carotid artery. The mechanisms of a cerebral infarct associated with pituitary apoplexy are discussed.

  6. Volume of the adrenal and pituitary glands in depression

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Willer, Inge Stoel; Knorr, Ulla

    2011-01-01

    Numerous studies have shown that the hypothalamic-pituitary-adrenal (HPA) axis is hyperactive in some depressed patients. It is unclear whether such hyperactivity results in changed volumes of the adrenal glands, pituitary gland and hypothalamus. We systematically reviewed all controlled studies ...

  7. Pituitary Volume Prospectively Predicts Internalizing Symptoms in Adolescence

    Science.gov (United States)

    Zipursky, Amy R.; Whittle, Sarah; Yucel, Murat; Lorenzetti, Valentina; Wood, Stephen J.; Lubman, Dan I.; Simmons, Julian G.; Allen, Nicholas B.

    2011-01-01

    Background: Early adolescence is a critical time for the development of both internalizing and externalizing disorders. We aimed to investigate whether pituitary volume, an index of hypothalamic-pituitary-adrenal (HPA) axis function, represents a vulnerability factor for the emergence of internalizing and externalizing symptoms during adolescence…

  8. Expression studies of neuronatin in prenatal and postnatal rat pituitary.

    Science.gov (United States)

    Kanno, Naoko; Higuchi, Masashi; Yoshida, Saishu; Yako, Hideji; Chen, Mo; Ueharu, Hiroki; Nishimura, Naoto; Kato, Takako; Kato, Yukio

    2016-05-01

    The pituitary gland, an indispensable endocrine organ that synthesizes and secretes pituitary hormones, develops with the support of many factors. Among them, neuronatin (NNAT), which was discovered in the neonatal mouse brain as a factor involved in neural development, has subsequently been revealed to be coded by an abundantly expressing gene in the pituitary gland but its role remains elusive. We analyze the expression profile of Nnat and the localization of its product during rat pituitary development. The level of Nnat expression was high during the embryonic period but remarkably decreased after birth. Immunohistochemistry demonstrated that NNAT appeared in the SOX2-positive stem/progenitor cells in the developing pituitary primordium on rat embryonic day 11.5 (E11.5) and later in the majority of SOX2/PROP1 double-positive cells on E13.5. Thereafter, during pituitary embryonic development, Nnat expression was observed in some stem/progenitor cells, proliferating cells and terminally differentiating cells. In postnatal pituitaries, NNAT-positive cells decreased in number, with most coexpressing Sox2 or Pit1, suggesting a similar role for NNAT to that during the embryonic period. NNAT was widely localized in mitochondria, peroxisomes and lysosomes, in addition to the endoplasmic reticulum but not in the Golgi. The present study thus demonstrated the variability in expression of NNAT-positive cells in rat embryonic and postnatal pituitaries and the intracellular localization of NNAT. Further investigations to obtain functional evidence for NNAT are a prerequisite. PMID:26613603

  9. Pituitary tumors in patients with MEN1 syndrome

    Directory of Open Access Journals (Sweden)

    Luis V. Syro

    2012-01-01

    Full Text Available We briefly review the characteristics of pituitary tumors associated with multiple endocrine neoplasia type 1. Multiple endocrine neoplasia type 1 is an autosomal-dominant disorder most commonly characterized by tumors of the pituitary, parathyroid, endocrine-gastrointestinal tract, and pancreas. A MEDLINE search for all available publications regarding multiple endocrine neoplasia type 1 and pituitary adenomas was undertaken. The prevalence of pituitary tumors in multiple endocrine neoplasia type 1 may vary from 10% to 60% depending on the studied series, and such tumors may occur as the first clinical manifestation of multiple endocrine neoplasia type 1 in 25% of sporadic and 10% of familial cases. Patients were younger and the time between initial and subsequent multiple endocrine neoplasia type 1 endocrine lesions was significantly longer when pituitary disease was the initial manifestation of multiple endocrine neoplasia type 1. Tumors were larger and more invasive and clinical manifestations related to the size of the pituitary adenoma were significantly more frequent in patients with multiple endocrine neoplasia type 1 than in subjects with non-multiple endocrine neoplasia type 1. Normalization of pituitary hypersecretion was much less frequent in patients with multiple endocrine neoplasia type 1 than in subjects with non-multiple endocrine neoplasia type 1. Pituitary tumors in patients with multiple endocrine neoplasia type 1 syndrome tend to be larger, invasive and more symptomatic, and they tend to occur in younger patients when they are the initial presentation of multiple endocrine neoplasia type 1.

  10. EFFECTS OF CAGING DENSITY ON PITUITARY AND TESTICLE RELATED RESPONSES

    Science.gov (United States)

    Effects of caging density on pituitary and testicle related responses A significant negative correlation between the incidence of testicular interstitial cell tumors (ICT) and of pituitary tumors (PT) in control male F344 rats is reported associated with the number of ani...

  11. Hyperprolactinemia associated to calcification of the pituitary stalk: case report

    Directory of Open Access Journals (Sweden)

    OLIVEIRA MIRIAM DA COSTA

    1998-01-01

    Full Text Available In this work, the authors report the case of a female patient with 24 years of age with hyperprolactinemia, who presented a pituitary stalk calcification as seen by CT scan. Once other possible etiologies were excluded, we concluded that the calcification was probably related to hyperprolactinemia caused by interruption of the input of dopamine to the pituitary gland.

  12. Hyperprolactinemia associated to calcification of the pituitary stalk: case report

    OpenAIRE

    OLIVEIRA MIRIAM DA COSTA; CREMONESE RAFAEL; PIZARRO CRISTINA

    1998-01-01

    In this work, the authors report the case of a female patient with 24 years of age with hyperprolactinemia, who presented a pituitary stalk calcification as seen by CT scan. Once other possible etiologies were excluded, we concluded that the calcification was probably related to hyperprolactinemia caused by interruption of the input of dopamine to the pituitary gland.

  13. Note: Switching crosstalk on and off in Kelvin probe force microscopy

    International Nuclear Information System (INIS)

    In Kelvin Probe Force Microscopy (KPFM) electronic crosstalk can occur between the excitation signal and probe deflection signal. Here, we demonstrate how a small modification to our commercial instrument enables us to literally switch the crosstalk on and off. We study in detail the effect of crosstalk on open-loop KPFM and compare with closed-loop KPFM. We measure the pure crosstalk signal and verify that we can correct for it in the data-processing required for open-loop KPFM. We also demonstrate that open-loop KPFM results are independent of the frequency and amplitude of the excitation signal, provided that the influence of crosstalk has been eliminated

  14. Pituitary adenoma: A case report with special emphasis on approach to diagnosis

    Directory of Open Access Journals (Sweden)

    Shaista M Vasenwala

    2014-01-01

    Full Text Available Pituitary tumors are common in sellar area. The prevalence of clinically apparent pituitary lesions is estimated to comprise approximately 10% of all intracranial lesions, while incidental pituitary tumors are detected in approximately 11% of individuals at autopsy. Pituitary tumors are mostly found to be benign adenomas, however pituitary carcinoma has been reported to comprise about 0.5% of pituitary tumors. Pituitary adenomas are associated with an immense diversity in their endocrine manifestations secondary to hypo or hyperfunction of pituitary gland and ophthalmological manifestations due to mass effect. Progress in the diagnostic examination of pituitary adenomas and advances in the treatment of these tumors offers excellent prospects for a successful therapeutic outcome. We hereby discuss a case of pituitary macro-adenoma in a young adult male and review the recent advances in the classification and diagnosis of pituitary adenoma.

  15. Diagnostic imaging of dopamine receptors in pituitary adenomas.

    Science.gov (United States)

    de Herder, Wouter W; Reijs, Ambroos E M; Feelders, Richard A; van Aken, Maarten O; Krenning, Eric P; van der Lely, Aart-Jan; Kwekkeboom, Dik J

    2007-04-01

    Dopamine D2 receptor scintigraphy of pituitary adenomas is feasible by single-photon emission computed tomography using (123)I-S-(-)-N-[(1-ethyl-2-pyrrolidinyl)methyl]-2-hydroxy-3-iodo-6-methoxybenzamide ((123)I-IBZM) and (123)I-epidepride. (123)I-epidepride is generally superior to (123)I-IBZM for the visualization of D2 receptors on pituitary macroadenomas. However, (123)I-IBZM and (123)I-epidepride scintigraphy are generally not useful to predict the response to dopaminergic treatment in pituitary tumour patients. These techniques might allow discrimination of non-functioning pituitary macroadenomas from other non-tumour pathologies in the sellar region. Dopamine D2 receptors on pituitary tumours can also be studied using positron emission tomography with (11)C-N-raclopride and (11)C-N-methylspiperone. PMID:17413189

  16. Research Advances in Pituitary Adenoma and DNA Methylation.

    Science.gov (United States)

    Wei, Zhen-Qing; Li, Yang; Li, Wei-Hua; Lou, Jia-Cheng; Zhang, Bo

    2016-08-01

    DNA methylation is closely related to the genesis and development of pituitary adenoma. Studies have shown that high methylation in the promoter region of potassium voltage-gated chanel,shaker related subfamily,beta member 2,O-6-methylguanine-DNA methyltransferase,echinoderm microtubule associated protein like 2 ,ras homolog family member D ,homeobox B1 ,NNAT, and P16 inhibits the expression of these genes and regulates of the proliferation of pituitary adenoma. DNA methylation is also closely related to invasive pituitary adenoma. Therefore,further study on molecular mechanism of DNA methylation of pituitary adenoma will offer a new strategy for the diagnosis and treatment of pituitary adenoma. PMID:27594164

  17. Cellular host responses to gliomas.

    Directory of Open Access Journals (Sweden)

    Joseph Najbauer

    together with pericytes give rise to tumor vasculature. Mapping the cellular composition of glioma microenvironment and deciphering the complex 'crosstalk' between tumor and host may ultimately aid the development of novel anti-glioma therapies.

  18. Pituitary hyperplasia: an uncommon presentation of a common disease

    Science.gov (United States)

    Massolt, E T; Peeters, R P; Neggers, S J; de Herder, W W

    2015-01-01

    Summary A 21-year-old woman presented with amenorrhea, bilateral galactorrhea and fatigue. Visual acuity and visual fields were normal. Laboratory examination demonstrated hyperprolactinemia. Magnetic resonance imaging (MRI) of the pituitary showed a 19×17×12-mm sellar mass with supra- and parasellar extension, causing compression of the pituitary stalk and optic chiasm. Further examinations confirmed mild hyperprolactinemia, strongly elevated TSH (>500 mU/l), low free thyroxine (FT4), hypogonadotropic hypogonadism and secondary adrenal insufficiency. Hydrocortisone and l-T4 replacement therapy was started. Three months later, the galactorrhea had disappeared, thyroid function was normalized and MRI revealed regression of the pituitary enlargement, confirming the diagnosis of pituitary hyperplasia (PH) due to primary hypothyroidism. Subsequently, the menstrual cycle returned and the hypocortisolism normalized. This case demonstrates that severe primary hypothyroidism may have an unusual presentation and should be considered in the differential diagnosis of pituitary enlargement associated with moderate hyperprolactinemia. Learning points One should always try to find one etiology as the common cause of all the clinical findings in a pathologic process.Amenorrhea, galactorrhea and fatigue may be the only presenting clinical manifestations of primary hypothyroidism.Not every patient with galactorrhea, hyperprolactinemia and a pituitary mass has a prolactinoma.Primary hypothyroidism should always be considered in the differential diagnosis of hyperprolactinemia associated with pituitary enlargement and pituitary hormone(s) deficiency(ies).When PH due to primary hypothyroidism is suspected, thyroid hormone replacement should be started and only regression of pituitary enlargement on MRI follow-up can confirm the diagnosis.Examination of thyroid function in patients with a pituitary mass may avoid unnecessary surgery. PMID:26279852

  19. Endoscopic transnasal approach for removing pituitary tumors

    Directory of Open Access Journals (Sweden)

    Mirian Cabral Moreira de Castro

    2014-05-01

    Full Text Available To describe a series of 129 consecutive patients submitted to the resection of pituitary tumors using the endoscopic transsphenoidal approach in a public medical center. Method: Retrospective analysis based on the records of patients submitted to the resection of a pituitary tumor through the endoscopic transsphenoidal approach between 2004 and 2009. Results: One hundred and twenty-nine records were analyzed. The tumor was non-secreting in 96 (74.42% and secreting in 33 patients (22.58%. Out of the secretory tumors, the most prevalent was the growth hormone producer (7.65%, followed by the prolactinoma, (6.98%. Eleven patients developed cerebral spinal fluid (CSF fistulas, and four of them developed meningitis. One patient died due to intracerebral hemorrhage in the postoperative period. Conclusion: The endoscopic transsphenoidal approach to sellar tumors proved to be safe when the majority of the tumors were non-secreting. The most frequent complication was CSF. This technique can be done even in a public hospital with financial limits, since the health professionals are integrated.

  20. Using rectangular trace to reduce the crosstalk of the coupled microstrip lines

    Directory of Open Access Journals (Sweden)

    Ahmed Ali Hussein

    2015-12-01

    Full Text Available New electronic products must have high-speed, small size and lower voltages supply. With such layout, signal integrity (SI becomes an actual important issue because sensitive equipment is affected on electromagnetic interference (EMI. Crosstalk is a major factor in signal integrity (SI of printed circuit boards (PCBs. Crosstalk noise is usually represented in terms of Near-End crosstalk (NEXT and Far-End crosstalk (FEXT. Crosstalk is a common problem that degrades circuit performance. To reduce this problem, via hole-fences connected by guard trace between double microstrip lines are used, in this case the crosstalk will be reduce by 6 dB than use 3W rule, but when it replaced by rectangular metal the crosstalk was reduce by 7dB, is better than use via hole-fences by 1 dB. The simulation result was done by using FEKO 5.5 simulator.

  1. Is technetium-99m-MIBI taken up by the normal pituitary gland? A comparison of normal pituitary glands and pituitary adenomas

    International Nuclear Information System (INIS)

    The aim of this study was to compare the behavioral uptake of a normal gland and a pituitary adenoma and to assess the ability to diagnose pituitary adenoma by means of technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (MIBI) single photon emission computed tomography (SPECT). The study included 15 patients with pituitary adenomas (mean age=44.0 years, range 19-63) and 15 control subjects (mean age=50.7 years, range 20-67). SPECT was performed 15 minutes after an intravenous injection of MIBI 600 MBq. The shape and location of MIBI uptake were evaluated on a magnetic resonance (MR) imaging/SPECT registration image. The shape patterns and location were classified as follows: Shape C (circular); LO (longitudinal oval); T/R (triangular or rectangular) and location P (pituitary gland or adenoma); D/C (dorsum sellae and/or clivus). Analysis of the uptake showed that 10 (67%) adenomas were C, and 5 (33%) were LO. Of the controls, 5 (33%) were C, and 10 (69%) were T/R. With regard to location, all patients with pituitary adenomas were classified as P, and all control subjects (93%) but one showed uptake in the dorsum sellae and clivus (D/C). MIBI was taken up in the dorsum sellae or clivus but not the normal pituitary gland and had a strong affinity for the pituitary adenoma. This result implies that MIBI SPECT may be a useful new auxiliary examination technique for the location diagnosis of pituitary adenoma. (author)

  2. Pituitary macroadenoma presenting with pituitary apoplexy, acromegaly and secondary diabetes mellitus - a case report.

    Science.gov (United States)

    Nganga, Hudson Kamau; Lubanga, Reuben Paul

    2013-01-01

    Pituitary adenomas are associated with significant morbidity. The usual symptoms on presentation are of endocrine dysfunction and mass effects. A 31-year-old African female presented with headache, irregular menses, blurring of vision in the right eye and complete loss of vision in the left eye for 1 year. She had coarse facial features, enlarged hands and feet. Her right eye had temporal hemianopia with decreased visual acuity and her left eye had no perception of light. Investigations revealed an elevated fasting blood sugar and an elevated prolactin and growth hormone level. A CT scan and MRI done showed a hemorrhagic pituitary macroadenoma. She was put on bromocriptine, ocreotide, analgesics and insulin. Thereafter, she underwent transphenoidal surgery, where near total resection of the tumor was achieved. Patient is doing well post-operatively. This case highlights the importance of the use of a high clinical index of suspicion and radiological findings in diagnosis. PMID:24062868

  3. Primary hypothyroidism mimicking a pituitary macroadenoma: regression after thyroid hormone replacement therapy

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Ki Seong; Kim, Jong Moon; Kim, Tae Young [Wonkwang University School of Medicine, Department of Neurosurgery, Iksan (Korea); See-Sung, Choi [Wonkwang University School of Medicine, Department of Radiology, Iksan (Korea); Kim, Jong Duck [Wonkwang University School of Medicine, Department of Pediatrics, Iksan (Korea)

    2009-02-15

    We report a 9-year-old girl with pituitary hyperplasia due to primary hypothyroidism. She presented with growth arrest, abnormal thyroid function studies, and a pituitary mass on MRI. With thyroxine therapy, the pituitary mass regressed and her symptoms resolved. Primary hypothyroidism should be considered in the differential diagnosis of solid mass lesions of the pituitary gland. (orig.)

  4. The prevalence of hyperprolactinemia in non-functioning pituitary macroadenomas

    Science.gov (United States)

    Zhang, Fangfang; Huang, Yinxing; Ding, Chenyu; Huang, Guoliang; Wang, Shousen

    2015-01-01

    Objective: The prevalence of hyperprolactinemia in non-functioning pituitary macroadenomas (NFPMAs) is not well known, and hyperprolactinemia caused by a NFPMA is currently associated with diagnostic uncertainty. Thus, the aim of this study was to evaluate the prevalence of hyperprolactinemia in NFPMAs. Methods: A meta-analysis of all existing articles in PubMed was conducted. The search string was designed as “(non-functioning pituitary tumor OR non-functioning pituitary tumor OR non-functioning pituitary macroadenomas OR non-functioning pituitary macroadenomas OR non-functioning pituitary adenomas OR non-functioning pituitary adenomas) and hyperprolactinemia”. References of the articles found were also reviewed. Study selection and data extraction were performed independently by two reviewers. Data were analyzed with STATA 11.0 software (StataCorp LP, USA). The fixed effects model was used to evaluate these studies. Results: The search identified 57 published studies, seven of which were accepted for the final meta-analysis. The authors found an overall estimated 40.2% prevalence of (95% CI, 36.6%-43.7%) hyperprolactinemia in NFPMAs. Conclusions: Given the high frequency of hyperprolactinemia in NFPMAs, a diagnosis of NFPMA or prolactinoma should be made more carefully. PMID:26770524

  5. Development and sexual dimorphism of the pituitary gland.

    Science.gov (United States)

    MacMaster, Frank P; Keshavan, Matcheri; Mirza, Yousha; Carrey, Normand; Upadhyaya, Ameet R; El-Sheikh, Rhonda; Buhagiar, Christian J; Taormina, S Preeya; Boyd, Courtney; Lynch, Michelle; Rose, Michelle; Ivey, Jennifer; Moore, Gregory J; Rosenberg, David R

    2007-02-13

    The pituitary gland plays a central role in sexual development and brain function. Therefore, we examined the effect of age and gender on pituitary volume in a large sample of healthy children and adults. Volumetric magnetic resonance imaging (MRI) was conducted in one hundred and fifty four (77 males and 77 females) healthy participants. Males were between the ages of 7 to 35 years (16.91+/-5.89 years) and females were 7 to 35 years of age (16.75+/-5.75 years). Subjects were divided into subgroups of age (7 to 9, 10 to 13, 14 to 17, 18 to 21, 22 and older) and sex (male/female). Pituitary gland volume differed between sexes when comparing the age groups (F=3.55, df=2, 143, p=0.03). Females demonstrated larger pituitary glands than males in the age 14 to 17 year old groups (p=0.04). Young (19 years and under) and old (20 years and older) females demonstrated a correlation between pituitary volume and age. Males did not show this relationship. These findings provide additional evidence for gender differences in the normative anatomy of the pituitary and may have relevance for the study of various childhood onset neuropsychiatric disorders in which pituitary dysfunction has been implicated. PMID:17174342

  6. Relationship Between Histopathology and Clinical Prognosis of Invasive Pituitary Adenoma

    Institute of Scientific and Technical Information of China (English)

    LIYong; SHUKai; DONGFangyong; WANFeng; LEITing; LILing

    2005-01-01

    Objective: To study the relationship between histopathology and clinical prognosis of invasive pituitary adenoma subjected to transsphenoidal surgery. Methods: The enrolled were 82 patients with invasive pituitary adenomas undergoing transsphenoidal surgery during Jan. 2000 May 2003 in our department with full MR imaging findings, pathology data and follow-up information. The follow-up duration was 5-30 months. Results: MR imaging findings of invasive pituitary adenoma included: depression of the sellar floor, involvement of sphenoid sinus and cavernous sinus, breakthrough of diaphragma sellae,encasement of internal carotid artery, etc. Pathological examination revealed that the invasion rate of dura in sella turcica was the highest among the structures around tumor. Pituitary adenoma apoplexy was found in 20 cases (24.4%). The total removal rate for PRL-secreting adenomas was significantly lower than that for non-secreting adenomas (P<0.01), but non-, GH-, ACTH-secreting adenomas had no significant differences. The recurrence rate of PRL-secreting adenornas was higher than that of non- and GH-secreting adenomas (P<0.05). Conclusion: Among invasive pituitary adenomas, the therapeutic effects of nonand GH-secreting pituitary adenomas are better than that of PRL-secreting adenomas. Invasive biological behaviors of invasive pituitary adenomas result in radical operation failure and postoperative recurrence.

  7. Pituitary macroadenoma presenting with pituitary apoplexy, acromegaly and secondary diabetes mellitus - a case report

    OpenAIRE

    Nganga, Hudson Kamau; Lubanga, Reuben Paul

    2013-01-01

    Pituitary adenomas are associated with significant morbidity. The usual symptoms on presentation are of endocrine dysfunction and mass effects. A 31-year-old African female presented with headache, irregular menses, blurring of vision in the right eye and complete loss of vision in the left eye for 1 year. She had coarse facial features, enlarged hands and feet. Her right eye had temporal hemianopia with decreased visual acuity and her left eye had no perception of light. Investigations revea...

  8. Epidermal Growth Factor Receptor (EGFR) Crosstalks in Liver Cancer

    International Nuclear Information System (INIS)

    Hepatocarcinogenesis is a complex multistep process in which many different molecular pathways have been implicated. Hepatocellular carcinoma (HCC) is refractory to conventional chemotherapeutic agents, and the new targeted therapies are meeting with limited success. Interreceptor crosstalk and the positive feedback between different signaling systems are emerging as mechanisms of targeted therapy resistance. The identification of such interactions is therefore of particular relevance to improve therapeutic efficacy. Among the different signaling pathways activated in hepatocarcinogenesis the epidermal growth factor receptor (EGFR) system plays a prominent role, being recognized as a “signaling hub” where different extracellular growth and survival signals converge. EGFR can be transactivated in response to multiple heterologous ligands through the physical interaction with multiple receptors, the activity of intracellular kinases or the shedding of EGFR-ligands. In this article we review the crosstalk between the EGFR and other signaling pathways that could be relevant to liver cancer development and treatment

  9. Alien Crosstalk Cancellation for Multipair Digital Subscriber Line Systems

    Directory of Open Access Journals (Sweden)

    Ginis George

    2006-01-01

    Full Text Available An overview of alien crosstalk cancellation for DSL systems with multiple pairs is here presented. It is shown that when a common crosstalk source affects the receivers of multiple pairs, the noise exhibits a certain correlation among the pairs. In a DMT system, the frequency-domain noise samples are most strongly correlated between pairs when they correspond to the same tone. Thus, noise decorrelation algorithms applied independently for each tone can provide significant performance enhancements. Three possible methods are described for noise decorrelation, one is suitable for two-sided coordination and two are suited for receiver coordination among the pairs. It is theoretically proven that the data-rate performance of these three methods is identical from the perspective of the sum rate over all pairs. Simulation results corresponding to an ADSL2+ two-pair system with a T1 disturber are presented to illustrate the noise correlation property and to indicate the potential performance benefits.

  10. Stochastic Proofreading Mechanism Alleviates Crosstalk in Transcriptional Regulation

    Science.gov (United States)

    Cepeda-Humerez, Sarah A.; Rieckh, Georg; Tkačik, Gašper

    2015-12-01

    Gene expression is controlled primarily by interactions between transcription factor proteins (TFs) and the regulatory DNA sequence, a process that can be captured well by thermodynamic models of regulation. These models, however, neglect regulatory crosstalk: the possibility that noncognate TFs could initiate transcription, with potentially disastrous effects for the cell. Here, we estimate the importance of crosstalk, suggest that its avoidance strongly constrains equilibrium models of TF binding, and propose an alternative nonequilibrium scheme that implements kinetic proofreading to suppress erroneous initiation. This proposal is consistent with the observed covalent modifications of the transcriptional apparatus and predicts increased noise in gene expression as a trade-off for improved specificity. Using information theory, we quantify this trade-off to find when optimal proofreading architectures are favored over their equilibrium counterparts. Such architectures exhibit significant super-Poisson noise at low expression in steady state.

  11. Crosstalk between pathways enhances the controllability of signalling networks.

    Science.gov (United States)

    Wang, Dingjie; Jin, Suoqin; Zou, Xiufen

    2016-02-01

    The control of complex networks is one of the most challenging problems in the fields of biology and engineering. In this study, the authors explored the controllability and control energy of several signalling networks, which consisted of many interconnected pathways, including networks with a bow-tie architecture. On the basis of the theory of structure controllability, they revealed that biological mechanisms, such as cross-pathway interactions, compartmentalisation and so on make the networks easier to fully control. Furthermore, using numerical simulations for two realistic examples, they demonstrated that the control energy of normal networks with crosstalk is lower than in networks without crosstalk. These results indicate that the biological networks are optimally designed to achieve their normal functions from the viewpoint of the control theory. The authors' work provides a comprehensive understanding of the impact of network structures and properties on controllability. PMID:26816393

  12. Disturbed temporal lobe circulation due to compression by pituitary adenoma

    International Nuclear Information System (INIS)

    The objective of this study was to clarify the pathophysiology of temporal lobe-related symptoms in pituitary adenoma by investigating temporal lobe circulation in pituitary adenoma with single photon emission computed tomography (SPECT). The subjects were 37 patients with pituitary adenoma (74 regions in the bilateral temporal lobes) who underwent 123I-iofetamine (IMP) SPECT before treatment. Using imaging analysis software 3D-SSP, the temporal lobes were evaluated in the bottom view on SPECT using the following method. Regions of interest (ROI) were established in the anteromedial (AM), posteromedial (PM), anterolateral (AL), and posterolateral (PL) regions of the temporal lobe, and the activity ratio (AR) of the counts/pixel in each ROI to those throughout the entire brain was determined. The AR in the 37 patients was compared with that in 37 healthy volunteers. Furthermore, the temporal lobes in patients with pituitary adenoma were classified according to the presence or absence of compression caused by the tumor, pituitary apoplexy, and hormone production, and evaluated. The AR in the AM and AL was significantly lower in the pituitary adenoma than in the healthy group (both, p<0.001). In the pituitary adenoma group, the AR in the AM, AL, and PL was significantly lower in the compression than in the non-compression group (p<0.05, p<0.05, and p<0.01, respectively). Classification based on the presence or absence of pituitary apoplexy or hormone production did not significantly differ with the AR values. We conclude that pituitary adenoma causes hypoperfusion in the temporal lobe at a high frequency, and direct compression by the tumor is a cause of regional cerebral blood flow (rCBF) reduction. (author)

  13. Clinical and histological study of pituitary fibrosarcoma following radiotherapy for pituitary adenoma

    International Nuclear Information System (INIS)

    A 49-year old male was admitted with a history of radiotherapy for a pituitary adenoma 9 years earlier. Three weeks prior to admission, he noticed visual loss in the left eye. Computed tomography (CT) scan revealed a sellar tumor. The patient underwent craniotomy and the tumor was partially resected. The histological diagnosis was benign pituitary adenoma. Two months after surgery, he began to complain of headache and left hemiparesis. CT scan at that time showed a large parasellar tumor extending into the right temporal lobe. A second craniotomy was performed and a firm tumor was partially removed. Under light microscopy, the tumor was composed of anaplastic spindle cells showing a fascicular pattern. Ultrastructurally, the tumor cells were spindle-shaped with elongated nuclei. The cytoplasm contained numerous distended rough endoplasmic reticula and free ribosomes, Golgi apparatus as well as glycogen granules. Some desmosome-like intercellular adherents were observed. Collagen fibers were scattered in the extracellular space. There was no apparent formation of a basement membrane. These findings suggested a close morphological similarity between tumor cells and fibroblasts, conforming to ultrastructural diagnostic criteria for fibrosarcoma. In spite of intensive treatment, such as a second radiotherapy and subsequent craniotomy, the patient died 9 months after admission. The clinical course and pathological findings of the post-irradiation pituitary fibrosarcoma are discussed. (author)

  14. Theory of multisource crosstalk reduction by phase-encoded statics

    KAUST Repository

    Schuster, Gerard T.

    2011-03-01

    Formulas are derived that relate the strength of the crosstalk noise in supergather migration images to the variance of time, amplitude and polarity shifts in encoding functions. A supergather migration image is computed by migrating an encoded supergather, where the supergather is formed by stacking a large number of encoded shot gathers. Analysis reveals that for temporal source static shifts in each shot gather, the crosstalk noise is exponentially reduced with increasing variance of the static shift and the square of source frequency. This is not too surprising because larger time shifts lead to less correlation between traces in different shot gathers, and so should tend to reduce the crosstalk noise. Analysis also reveals that combining both polarity and time statics is a superior encoding strategy compared to using either polarity statics or time statics alone. Signal-to-noise (SNR) estimates show that for a standard migration image and for an image computed by migrating a phase-encoded supergather; here, G is the number of traces in a shot gather, I is the number of stacking iterations in the supergather and S is the number of encoded/blended shot gathers that comprise the supergather. If the supergather can be uniformly divided up into Q unique sub-supergathers, then the resulting SNR of the final image is, which means that we can enhance image quality but at the expense of Q times more cost. The importance of these formulas is that they provide a precise understanding between different phase encoding strategies and image quality. Finally, we show that iterative migration of phase-encoded supergathers is a special case of passive seismic interferometry. We suggest that the crosstalk noise formulas can be helpful in designing optimal strategies for passive seismic interferometry and efficient extraction of Green\\'s functions from simulated supergathers. © 2011 The Authors Geophysical Journal International © 2011 RAS.

  15. Microbial Hijacking of Complement–Toll-like Receptor Crosstalk*

    OpenAIRE

    WANG Min; Krauss, Jennifer L.; Domon, Hisanori; Hosur, Kavita B.; Liang, Shuang; Magotti, Paola; Triantafilou, Martha; Triantafilou, Kathy; Lambris, John D.; Hajishengallis, George

    2010-01-01

    Recent evidence suggests that complement and Toll-like receptors (TLRs) crosstalk to coordinate innate immunity. We report a novel immune subversion mechanism involving microbial exploitation of the ability of complement and TLRs for communication. Porphyromonas gingivalis, a major oral and systemic pathogen expressing complement C5 convertase-like activity, was shown to synergize with C5a for cAMP elevation resulting in macrophage immunosuppression and enhanced pathogen survival in vitro and...

  16. Silent pituitary adenomas: review and clinical cases

    Directory of Open Access Journals (Sweden)

    Anna Konstantinovna Lipatenkova

    2015-06-01

    Full Text Available Silent, or clinically nonfunctioning adenomas are morphologically heterogeneous group, characterized by positive immunoreactivity for one or more hormones classically secreted by normal pituitary cells but without clinical expression. Although in some occasions enhanced or changed secretory activity can develop over time. According to immunoreactivity they are divided into "silent" gonado-, cortico-, somato -, mammo – and thyrotropinomas, oncocytomas, «zero-cell» tumors. All types of "silent" adenomas have different biological activity, secretory capacity and outcomes in the postoperative period. This series of clinical cases shows more «aggressiveness», a higher risk of relapse for "silent" cortico- and somatotropinomas. Immunohistochemical analysis of residual tissue can be used to identify patients with high risk of recurrence, to develop optimal treatment and follow-up.

  17. Follicle stimulating hormone secreting pituitary adenoma: a challenging diagnosis

    Directory of Open Access Journals (Sweden)

    Madhuri Alap Mehendale

    2015-04-01

    Full Text Available FSH secreting pituitary adenomas are relatively uncommon brain tumours and usually non-functioning. But in rare cases they produce ovarian hyperstimulation. We report a case of a 32 year old female P2L2, with amenorrhoea of 1 year, pain in abdomen and galactorrhoea since 6 months. Initially thought to be a simple prolactinoma with multicystic ovaries, but after thorough investigations to our surprise diagnosed to be a rare case of gonadotropin secreting pituitary adenoma. Patient was successfully managed by excision of the pituitary adenoma. [Int J Reprod Contracept Obstet Gynecol 2015; 4(2.000: 493-496

  18. Electrophoretic separation of kidney and pituitary cells on STS-8

    Science.gov (United States)

    Morrison, D. R.; Nachtwey, D. S.; Barlow, G. H.; Cleveland, C.; Lanham, J. W.; Farrington, M. A.; Hatfield, J. M.; Hymer, W. C.; Grindeland, R.; Lewis, M. L.

    1984-01-01

    Specific secretory cells were separated from suspensions of cultured primary human embryonic cells and rat pituitary cells in microgravity conditions, with an objective of isolating the subfractions of kidney cells that produce the largest amount of urakinase, and the subfractions of rat pituitary cells that secrete growth hormones (GH), prolactin (PRL), and other hormones. It is inferred from the experimental observations that the surface charge distributions of the GH-containing cells differ from those of the PRL-containing cells, which is explained by the presence of secretory products on the surface of pituitary cells. For kidney cells, the electrophoretic mobility distributions in flight experiments were spread more than the ground controls.

  19. Electronic crosstalk characterization of Terra MODIS long wave infrared channels

    Science.gov (United States)

    Madhavan, Sriharsha; Xiong, Xiaoxiong; Sun, Junqiang; Chiang, Kwofu; Wu, Aisheng

    2015-09-01

    Terra (T) MODerate-resolution Imaging Spectroradiometer (MODIS), a heritage Earth observing sensor has completed 15 years of operation as of December 18 2014. T-MODIS has 36 spectral channels designed to monitor the land, ocean, and atmosphere. The long term climate data record from T-MODIS is an important dataset for global change monitoring. Sixteen of the spectral channels fall in the Mid (M) (3.7-4.5μm) to Long (L) (6.7-14.1μm)Wave InfraRed (M/LWIR) wavelengths, which are also referred to as the Thermal Emissive Bands (TEBs). To date the TEBs have very satisfactory performance which is attributed to the scan-by-scan calibration using an on-board BlackBody whose temperature is traceable to the NIST temperature standards. However, with an aging instrument, it was observed from 2010 onwards that the Photo Voltaic LWIR channels (Bands 27-30) have suffered significantly from electronic crosstalk. This is mainly due to the deterioration of the electronic circuits of the relevant bands in the LWIR Focal Plane Array (FPA). In this paper, we report the characterization of the electronic crosstalk in the above-mentioned bands using the well characterized test site such as Dome Concordia (C). Such characterization can be used to reduce the effects of crosstalk when implemented in the future Level 1B reprocessing and thereby increasing the radiometric fidelity of the concerned bands.

  20. Thermal crosstalk in arrays of III-N-based Lasers

    International Nuclear Information System (INIS)

    This paper presents a 3D comprehensive thermal-electrical self-consistent model of the continuous-wave (CW) operation of one-dimensional arrays of III-N-based laser diodes at room-temperature (RT). Their performance is mostly limited by thermal processes, in particular by thermal crosstalk between array emitters. Based on data collected from a range of secondary sources, the temperature dependence of the thermal and electrical conductivities of III-N materials used to manufacture nitride-based devices is shown to be a function of the thickness, aluminum mole fractions and Si- and Mg-doping levels of the nitride layers. The impact of substrate width and thickness on increasing the efficiency of heat-flux transport and reducing thermal crosstalk is investigated. As expected, the application of a top-mounted diamond heat spreader was found to have considerable influence on the thermal crosstalk between array emitters, enabling the RT CW operation of laser diode arrays with additional emitters

  1. Pituitary gland height evaluated by MR in patients with β-thalassemia major: a marker of pituitary gland function

    International Nuclear Information System (INIS)

    In transfusion-dependent β-thalassemia major, increased iron deposition in the pituitary gland has a cytotoxic effect leading mainly to hypogonadotropic hypogonadism. Our purpose was to assess in these patients the height of the pituitary gland and to evaluate whether it represents a marker of pituitary gland function. In 29 patients with β-thalassemia major and 35 age- and gender-matched controls the pituitary gland height was evaluated in a midline sagittal scan using a spin echo T1-weighted (500/20 TR/TE) sequence. In all patients, an extensive endocrine evaluation was performed, including measurements of spontaneous and stimulated levels of gonadotropins, thyroid hormones, growth hormone, insulin-like growth factor, and adrenal hormones. The pituitary gland height was lower in thalassemic patients with hypogonadotropic hypogonadism (n=15) (mean 3.48; SD 0.46) than in the age- and gender-matched controls (mean 6.29; SD 0.77), (P<0.001). No statistically significant difference was found between thalassemic patients without hormone dysfunction (n=14) (mean 5.34; SD 1.52) and age- and gender-matched controls (mean 5.91; SD 1.06). We conclude that in thalassemic patients the pituitary gland height is an additional marker of pituitary gland function and might be useful in clinical management. (orig.)

  2. Reversible pituitary hyperplasia at birth in a macrosomic full-term baby boy

    International Nuclear Information System (INIS)

    Pituitary hyperplasia is generally associated with end-organ failure such as primary hypothyroidism, physiological changes such as puberty and pregnancy, or neoplasms secreting releasing factors. We present a full-term infant with an enlarged pituitary height of 8 mm at age 3 days despite a normal endocrinological evaluation. Repeat imaging at 5 months of age revealed a normal-size pituitary gland. To our knowledge, pituitary hyperplasia has not been described in a neonate with normal pituitary function. (orig.)

  3. Reversible pituitary hyperplasia at birth in a macrosomic full-term baby boy

    Energy Technology Data Exchange (ETDEWEB)

    Osipoff, Jennifer; Wilson, Thomas A. [State University of New York, Division of Pediatric Endocrinology, Department of Pediatrics, Stony Brook, NY (United States); Peyster, Robert [Stony Brook University Medical Center, Department of Radiology, Stony Brook, NY (United States)

    2010-12-15

    Pituitary hyperplasia is generally associated with end-organ failure such as primary hypothyroidism, physiological changes such as puberty and pregnancy, or neoplasms secreting releasing factors. We present a full-term infant with an enlarged pituitary height of 8 mm at age 3 days despite a normal endocrinological evaluation. Repeat imaging at 5 months of age revealed a normal-size pituitary gland. To our knowledge, pituitary hyperplasia has not been described in a neonate with normal pituitary function. (orig.)

  4. Pregnancy and pituitary disorders: Challenges in diagnosis and management

    Directory of Open Access Journals (Sweden)

    Bashir A Laway

    2013-01-01

    Full Text Available Pregnancy is associated with normal physiological changes in endocrine system that assists fetal survival as well as preparation of labor. The pituitary gland is one of the most affected organs in which major changes in anatomy and physiology take place. Due to overlapping clinical and biochemical features of pregnancy, sometimes the diagnosis of pituitary disorders may be challenging. It is important to know what normal parameters of changes occur in endocrine system in order to diagnose and manage complex endocrine problems in pregnancy. In our present review, we will focus on pituitary disorders that occur exclusively during pregnancy like Sheehan′s syndrome and lymphocytic hypophysitis and pre-existing pituitary disorders (like prolactinoma, Cushing′s disease and acromegaly, which poses significant challenge to endocrinologists.

  5. Coexisting intracranial tumors with pituitary adenomas: Genetic association or coincidence?

    Directory of Open Access Journals (Sweden)

    Furtado Sunil

    2010-01-01

    Full Text Available The co-occurrence of two or more brain tumors with different histological features is rare. The authors report three rare cases of intracranial tumors associated with pituitary adenomas. Two of the pituitary tumors were functioning adenomas: a prolactinoma and a thyrotropin secreting adenoma. Two of the associated intracranial neoplasms were gliomas and one was a meningioma. Radiological and clinical examination for syndromal association was negative in all cases. We briefly discuss the presentation and treatment options of these cases and review the 19 previous publications in the literature of pituitary tumors occurring in association with other neoplasms and explore the possible links underlying these co-occurring neoplasms. Our three cases represent 0.86% of all pituitary tumors operated at our institute over a 9-year period.

  6. Response of silent corticotroph pituitary carcinoma to chemotherapy: case report.

    Science.gov (United States)

    He, Lucy; Forbes, Jonathan A; Carr, Kevin; Highfield Nickols, Hilary; Utz, Andrea; Moots, Paul; Weaver, Kyle

    2016-06-01

    Silent pituitary corticotroph carcinomas are rare, with only six previously described cases in the literature. We report a patient with a silent pituitary corticotroph adenoma treated with multiple trans-sphenoidal resections. Twelve years after her initial presentation, she returned with leptomeningeal metastases to the posterior fossa, foramen magnum, and numerous other subarachnoid locations involving the spine. Histopathology obtained from the metastatic foci was identical to previous trans-sphenoidal specimens - consistent with the diagnosis of corticotroph pituitary carcinoma. A carboplatin and etoposide chemotherapy regimen successfully arrested disease progression and produced regression of multiple radiographically documented leptomeningeal deposits. To the authors' knowledge, this is the first report of a patient with silent pituitary carcinoma treated successfully with chemotherapy. PMID:27150544

  7. Purification and cultivation of human pituitary growth hormone secreting cells

    Science.gov (United States)

    Hymer, W. C.

    1984-01-01

    A multiphase study was conducted to examine the properties of growth hormone cells. Topics investigated included: (1) to determine if growth hormone (GH) cells contained within the rat pituitary gland can be separated from the other hormone producing cell types by continuous flow electrophoresis (CFE); (2) to determine what role, if any, gravity plays in the electrophoretic separation of GH cells; (3) to compare in vitro GH release from rat pituitary cells previously exposed to microgravity conditions vs release from cells not exposed to microgravity; (4) to determine if the frequency of different hormone producing pituitary cell types contained in cell suspensions can be quantitated by flow cytometry; and (5) to determine if GH contained within the human post mortem pituitary gland can be purified by CFE. Specific experimental procedures and results are included.

  8. Immediate postoperative complications in transsphenoidal pituitary surgery: A prospective study

    Directory of Open Access Journals (Sweden)

    Tumul Chowdhury

    2014-01-01

    Full Text Available Background: Considering the important role of pituitary gland in regulating various endocrine axes and its unique anatomical location, various postoperative complications can be anticipated resulting from surgery on pituitary tumors. We examined and categorized the immediate postoperative complications according to various tumor pathologies. Materials and Methods: We carried out a prospective study in 152 consecutive patients and noted various postoperative complications during neurosurgical intensive care unit stay (within 48 hrs of hospital stay in patients undergoing transsphenoidal removal of pituitary tumors. Results: In our series, various groups showed different postoperative complications out of which, cerebrospinal fluid leak was the commonest followed by diabetes insipidus, postoperative nausea and vomiting, and hematoma at operation site. Conclusion: Various immediate postoperative complications can be anticipated in transsphenoidal pituitary surgery even though, it is considered to be relatively safe.

  9. Ectopic pituitary adenoma presenting as midline nasopharyngeal mass.

    LENUS (Irish Health Repository)

    Ali, R

    2012-02-01

    INTRODUCTION: Ectopic pituitary adenomas are extremely rare. We report a case of ectopic pituitary adenoma in the midline of the nasopharynx. This adenoma probably arose from the pharyngeal remnant of Rathke\\'s pouch. METHODS: We discuss a case of a lady who presented to our unit with 2 months history of dryness and sensation of lump in her throat and a long standing history of hypothyroidism. Examination of nasopharynx revealed a smooth and fluctuant midline mass. CT scan of nose and paranasal sinuses confirmed the midline mass with small defect communicating with the sphenoid sinus. An initial diagnosis of Thornwaldt\\'s cyst was made and she underwent upper aerodigestive tract endoscopy and marsupialization of the mass. Histopathological examination revealed ectopic pituitary adenoma. CONCLUSION: Ectopic pituitary adenoma is an important differential diagnosis for a midline nasopharyngeal mass. It is recommended that prior to surgical resection of midline nasopharyngeal mass biopsy is taken and MRI is performed.

  10. Volume of the adrenal and pituitary glands in depression

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Willer, Inge Stoel; Knorr, Ulla

    2011-01-01

    Numerous studies have shown that the hypothalamic-pituitary-adrenal (HPA) axis is hyperactive in some depressed patients. It is unclear whether such hyperactivity results in changed volumes of the adrenal glands, pituitary gland and hypothalamus. We systematically reviewed all controlled studies on...... the adrenal or pituitary glands or hypothalamus volume in unipolar depressive disorder published in PubMed 1966 to December 2009. We identified three studies that investigated the volume of the adrenal glands and eight studies that examined the volume of the pituitary gland, but no studies on...... identified such as small population samples, different subtypes of depression and insufficient matching of patients and controls. Due to large heterogeneity of study designs and data, it was futile to make a meta-analysis. It is concluded that it remains unclear whether hyperactivity of the HPA axis results...

  11. Spatial Cross-Talk between Oxidative Stress and DNA Replication in Human Fibroblasts.

    Science.gov (United States)

    Radulovic, Marko; Baqader, Noor O; Stoeber, Kai; Godovac-Zimmermann, Jasminka

    2016-06-01

    MS-based proteomics has been applied to a differential network analysis of the nuclear-cytoplasmic subcellular distribution of proteins between cell-cycle arrest: (a) at the origin activation checkpoint for DNA replication, or (b) in response to oxidative stress. Significant changes were identified for 401 proteins. Cellular response combines changes in trafficking and in total abundance to vary the local compartmental abundances that are the basis of cellular response. Appreciable changes for both perturbations were observed for 245 proteins, but cross-talk between oxidative stress and DNA replication is dominated by 49 proteins that show strong changes for both. Many nuclear processes are influenced by a spatial switch involving the proteins {KPNA2, KPNB1, PCNA, PTMA, SET} and heme/iron proteins HMOX1 and FTH1. Dynamic spatial distribution data are presented for proteins involved in caveolae, extracellular matrix remodelling, TGFβ signaling, IGF pathways, emerin complexes, mitochondrial protein import complexes, spliceosomes, proteasomes, and so on. The data indicate that for spatially heterogeneous cells cross-compartmental communication is integral to their system biology, that coordinated spatial redistribution for crucial protein networks underlies many functional changes, and that information on dynamic spatial redistribution of proteins is essential to obtain comprehensive pictures of cellular function. We describe how spatial data of the type presented here can provide priorities for further investigation of crucial features of high-level spatial coordination across cells. We suggest that the present data are related to increasing indications that much of subcellular protein transport is constitutive and that perturbation of these constitutive transport processes may be related to cancer and other diseases. A quantitative, spatially resolved nucleus-cytoplasm interaction network is provided for further investigations. PMID:27142241

  12. Diagnostic pitfalls of hyperprolactinemia: the importance of sequential pituitary imaging

    OpenAIRE

    KAWAGUCHI, Tomohiro; Ogawa, Yoshikazu; Tominaga, Teiji

    2014-01-01

    Background The purpose of this study is to confirm whether the serum prolactin cut-off value is definitive to distinguish prolactinoma and non-functioning pituitary adenoma with hyperprolactinemia. We retrospectively reviewed patients with non-functioning pituitary adenoma, including gonadotroph cell adenoma, null cell adenoma and prolactinoma who were surgically treated at Kohnan hospital between June 2005 and March 2012. The patients without endocrinological/neurological symptom and with th...

  13. Dopamine receptor expression and function in corticotroph pituitary tumors

    OpenAIRE

    Pivonello, Rosario; Lamberts, Steven; Ferone, Diego; De Herder, Wouter; Kros, Johan; Caro, M.L.; M. Arvigo; Annunziato, L; Lombardi, Gaetano; Colao, Annamaria; Hofland, Leo

    2004-01-01

    textabstractThe role of dopamine agonist treatment in corticotroph pituitary tumors is controversial. The aim of this study was to evaluate D(2) receptor expression in 20 corticotroph pituitary tumors and to correlate it to the in vitro effect of dopamine agonists on ACTH secretion and the in vivo effect of short-term cabergoline treatment on cortisol secretion. D(2) expression was evaluated by receptor-ligand binding, immunohistochemistry, and RT-PCR. A 50% or more decrease in daily urinary ...

  14. Metastatic pituitary carcinoma: a case report and review of literature

    OpenAIRE

    ZHANG Shang-fu; He, Xin; Zhang, Wen-Yan; Gong, Jing; YE Yun-xia

    2013-01-01

    Background As a kind of rare tumor, metastatic pituitary carcinoma is very difficult to diagnose clinically and is easy to be misdiagnosed. This article aims to discuss the clinical manifestations and histopathological features of this tumor. Methods The clinical presentations, histopathological features and immunophenotype were studied in one case of poorly differentiated lung adenocarcinoma metastatic to pituitary gland, and related literature was reviewed. Results A 47-year-old woman mainl...

  15. Pituitary hyperplasia: an uncommon presentation of a common disease

    OpenAIRE

    Neves, C P; Massolt, E T; Peeters, R P; Neggers, S J; de Herder, W. W.

    2015-01-01

    Summary A 21-year-old woman presented with amenorrhea, bilateral galactorrhea and fatigue. Visual acuity and visual fields were normal. Laboratory examination demonstrated hyperprolactinemia. Magnetic resonance imaging (MRI) of the pituitary showed a 19×17×12-mm sellar mass with supra- and parasellar extension, causing compression of the pituitary stalk and optic chiasm. Further examinations confirmed mild hyperprolactinemia, strongly elevated TSH (>500 mU/l), low free thyroxine (FT4), hypogo...

  16. Pituitary metastasis from breast cancer presenting as diabetes insipidus

    OpenAIRE

    Gormally, Joseph F; Izard, Michael A.; Robinson, Bruce G.; Boyle, Frances M

    2014-01-01

    An 83-year-old woman developed pituitary metastasis while being treated for metastatic breast cancer. She presented with visual disturbance and headache followed by thirst, nocturia and polyuria. A visual field defect was present. MRI revealed a sellar mass consistent with metastasis to the pituitary gland. She was successfully treated with radiotherapy to the sella and had improvement of her visual symptoms and visual field defect. She then required ongoing treatment for diabetes insipidus. ...

  17. Calculation of pad cross-talk in a thin-gap multiwire detector with pad readout

    International Nuclear Information System (INIS)

    Mechanisms responsible for cross-talk in a thin-gap multiwire chamber with pad readout are discussed. Using a simple capacitive coupling model, the cross-talk is calculated as a function of chamber geometry, capacitances and charge integration time. Calculation results are compared and found to be in reasonable agreement with measurements. Suggestions are given for reducing cross-talk in such a chamber. (orig.)

  18. Test Beam Measurement of the Crosstalk in the EM Barrel Module 0

    CERN Document Server

    Hubaut, F; Lacour, D; Orsini, F

    2000-01-01

    Test beam measurements of the crosstalk in the barrel electromagnetic calorimeter Module 0 tested at CERN in August 99' are reported. The main sources of crosstalk coming either from electronics or from physical effects on the electrodes have been identified and quantified. This has been done for the crosstalks between the different parts of the module, namely middle-middle, middle-back, middle-front, back-back, back-middle, back-front, front-front and front-middle.

  19. Investigation and Mitigation of the Crosstalk Effect in Terra MODIS Band 30

    OpenAIRE

    Junqiang Sun; Sriharsha Madhavan; Menghua Wang

    2016-01-01

    It has been previously reported that thermal emissive bands (TEB) 27–29 in the Terra (T-) MODerate resolution Imaging Spectroradiometer (MODIS) have been significantly affected by electronic crosstalk. Successful linear theory of the electronic crosstalk effect was formulated, and it successfully characterized the effect via the use of lunar observations as viable inputs. In this paper, we report the successful characterization and mitigation of the electronic crosstalk for T-MODIS band 30 us...

  20. Low crosstalk Bragg grating/Mach-Zehnder interferometer optical add-drop multiplexer in silicon photonics.

    Science.gov (United States)

    Wang, Junjia; Chen, Lawrence R

    2015-10-01

    We characterize the interferometric crosstalk and system performance of two optical add-drop multiplexer (OADM) designs based on Bragg grating/Mach-Zehnder interferometers implemented in silicon-on-insulator. Both OADM designs exhibit low crosstalk and negligible crosstalk-induced power penalties over their 3 dB bandwidths. The devices are tolerant to wavelength drift and misalignment between the transmitter and OADM; moreover, their designs can be optimized further to enable high performance operation in WDM systems. PMID:26480158

  1. Evaluation of pituitary adenomas by multidirectional multislice dynamic CT

    International Nuclear Information System (INIS)

    Purpose: Multidetector-row CT is a new technology with a short scanning time. Multislice dynamic CT (MSDCT) in various directions can be obtained using the multidetector-row CT with multiplanar reformatting (MPR) technique. Material and Methods: We evaluated the initial results of sagittal and coronal MSDCT images reconstructed by MPR (MSDCT-MPR) in 3 pituitary adenoma patients with a pacemaker. Results: In a patient with microadenoma, the maximum contrast between the normal anterior pituitary gland and the adenoma occurred approximately 50 s after the start of the contrast medium injection. A microadenoma was depicted as a less enhanced area relative to normal pituitary tissue. The macroadenomas were depicted as a less enhanced mass with cavernous sinus invasion in 1 patient and as a non-uniformly enhanced mass in another patient. Bone destruction and incomplete opening of the sellar floor during previous surgery were clearly detected in 2 patients with macroadenomas. These pituitary adenomas were removed via the transnasal route based on information from the MSDCT-MPR images only. The findings were verified surgically. Conclusion: The MSDCT-MPR provided the information needed for surgery with good image quality in the 3 patients with pacemakers. MSDCT-MPR appears to be a useful technique for patients with a pituitary adenoma in whom MR imaging is not available. This is the first report, to our knowledge, of the MSDCT-MPR technique being used to demonstrate pituitary disorders

  2. Outcome After Pituitary Radiosurgery for Thalamic Pain Syndrome

    International Nuclear Information System (INIS)

    Purpose: To evaluate outcomes after pituitary radiosurgery in patients with post-stroke thalamic pain syndrome. Methods and Materials: From 2002 to 2006, 24 patients with thalamic pain syndrome underwent pituitary radiosurgery at Tokyo Women's Medical University and were followed at least 12 months thereafter. The radiosurgical target was defined as the pituitary gland and its connection with the pituitary stalk. The maximum dose varied from 140 to 180 Gy. Mean follow-up after treatment was 35 months (range, 12-48 months). Results: Initial pain reduction, usually within 48 h after radiosurgery, was marked in 17 patients (71%). However, in the majority of cases the pain recurred within 6 months after treatment, and at the time of the last follow-up examination durable pain control was marked in only 5 patients (21%). Ten patients (42%) had treatment-associated side effects. Anterior pituitary abnormalities were marked in 8 cases and required hormonal replacement therapy in 3; transient diabetes insipidus was observed in 2 cases, transient hyponatremia in 1, and clinical deterioration due to increase of the numbness severity despite significant reduction of pain was seen once. Conclusions: Pituitary radiosurgery for thalamic pain results in a high rate of initial efficacy and is accompanied by acceptable morbidity. It can be used as a primary minimally invasive management option for patients with post-stroke thalamic pain resistant to medical therapy. However, in the majority of cases pain recurrence occurs within 1 year after treatment

  3. Crosstalk Enhancement in 32 nm FD SOI MOSFET using HR Substrate and Multilayer BOX

    Directory of Open Access Journals (Sweden)

    Parisa Tavanazadeh

    2011-06-01

    Full Text Available In this paper, the crosstalk in 32 nm UTB SOI MOSFET is examined by using a new structure, a high resistivity substrate, and a multilayer BOX (SiO2-Diamond. The electrical and thermal characteristics of the conventional SOI and a multilayer BOX SOI are compared, and it is concluded that parasitic capacitances and crosstalk are improved by incorporating multilayer BOX to a HR Substrate. In a conventional HR FD SOI, crosstalk is approximately -121dB, while by incorporating multilayer BOX substrate and increasing the thickness of the Diamond to 100nm, crosstalk can be reduced by 20%.

  4. Transcriptome Analysis of Individual Stromal Cell Populations Identifies Stroma-Tumor Crosstalk in Mouse Lung Cancer Model

    Directory of Open Access Journals (Sweden)

    Hyejin Choi

    2015-02-01

    Full Text Available 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.

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

    Science.gov (United States)

    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

  6. Changes of porcine growth hormone and pituitary nitrogen monoxide production as a response to cadmium toxicity.

    Science.gov (United States)

    Han, Xin-Yan; Huang, Qi-Chun; Liu, Bo-Jing; Xu, Zi-Rong; Wang, Yi-Zhen

    2007-11-01

    The present study was designed to investigate the effects of various cadmium concentrations on porcine growth hormone (GH) secretion in serum and cultured pituitary cells and to explore the possible mechanisms of cadmium toxicity. In feeding trial, 192 barrows (Duroc x Landrace x Yorkshire), with similar initial body weights, were randomly divided into four different treatment groups with three replicates for each treatment. The diets were supplemented for 83 days with 0, 0.5, 5.0, and 10.0 mg/kg cadmium (as CdCl2). For the cell culture trial, dispersed pituitary cells were incubated with graded doses of cadmium (0, 5, 10, 15, or 20 microM) for 24 h. Pigs treated with 10 mg/kg cadmium had significantly decreased serum GH content. 3-(4,5-dimethyl-2-yl)-2,5-diphenyl tetrazolium bromide assay showed that Cd toxicity was dose-dependent. Cell viability was reduced to 50% at 15 microM concentration. Administration of cadmium significantly reduced GH secretion, whereas cellular NO content and inducible nitric oxide synthase activity increased to a certain extent. These findings suggest that the decrease of GH might be related to NO production and to a change of NO signal pathway caused by cadmium. PMID:17916936

  7. In vitro impact of pegvisomant on growth hormone-secreting pituitary adenoma cells.

    Science.gov (United States)

    Cuny, Thomas; Zeiller, Caroline; Bidlingmaier, Martin; Défilles, Céline; Roche, Catherine; Blanchard, Marie-Pierre; Theodoropoulou, Marily; Graillon, Thomas; Pertuit, Morgane; Figarella-Branger, Dominique; Enjalbert, Alain; Brue, Thierry; Barlier, Anne

    2016-07-01

    Pegvisomant (PEG), an antagonist of growth hormone (GH)-receptor (GHR), normalizes insulin-like growth factor 1 (IGF1) oversecretion in most acromegalic patients unresponsive to somatostatin analogs (SSAs) and/or uncontrolled by transsphenoidal surgery. The residual GH-secreting tumor is therefore exposed to the action of circulating PEG. However, the biological effect of PEG at the pituitary level remains unknown. To assess the impact of PEG in vitro on the hormonal secretion (GH and prolactin (PRL)), proliferation and cellular viability of eight human GH-secreting tumors in primary cultures and of the rat somatolactotroph cell line GH4C1. We found that the mRNA expression levels of GHR were characterized in 31 human GH-secreting adenomas (0.086 copy/copy β-Gus) and the GHR was identified by immunocytochemistry staining. In 5/8 adenomas, a dose-dependent inhibition of GH secretion was observed under PEG with a maximum of 38.2±17% at 1μg/mL (Phuman primary tumors or GH4C1 cell line was observed. We conclude that PEG inhibits the secretion of GH and PRL in primary cultures of human GH(/PRL)-secreting pituitary adenomas without effect on cell viability or cell proliferation. PMID:27267119

  8. Experimental Modification of Rat Pituitary Growth Hormone Cell Function During and After Spaceflight

    Science.gov (United States)

    Hymer, W. C.; Salada, T.; Nye, P.; Grossman, E. J.; Lane, P. K.; Grindeland, R. E.

    1996-01-01

    Space-flown rats show a number of flight-induced changes in the structure and function of pituitary Growth Hormone (GH) cells after in vitro postflight testing. To evaluate the possible effects of microgravity on GH cells themselves, freshly dispersed rat anterior pituitary gland cells were seeded into vials containing serum +/- 1 micron HydroCortisone (HC) before flight. Five different cell preparations were used: the entire mixed-cell population of various hormone-producing cell types, cells of density less than 1.071 g/sq cm (band 1), cells of density greater than 1.071 g/sq cm (band 2), and cells prepared from either the dorsal or ventral part of the gland. Relative to ground control samples, bioactive GH released from dense cells during flight was reduced in HC-free medium but was increased in HC-containing medium. Band I and mixed cells usually showed opposite HC-dependent responses. Release of bioactive GH from ventral flight cells was lower; postflight responses to GH-releasing hormone challenge were reduced, and the cytoplasmic area occupied by GH in the dense cells was greater. Collectively, the data show that the chemistry and cellular makeup of the culture system modifies the response of GH cells to microgravity. As such, these cells offer a system to identify gravisensing mechanisms in secretory cells in future microgravity research.

  9. Temozolomide treatment of a pituitary carcinoma and two pituitary macroadenomas resistant to conventional therapy

    DEFF Research Database (Denmark)

    Schroeder, H D; Hansen, S; Hagen, C;

    2009-01-01

    (patient C), were highly invasive. The three patients suffered from extensive tumour mass effects, and all tumours were resistant to conventional treatment. METHOD: TMZ, 150-200 mg/m(2) of body surface area was administered orally for 5 days during each 28-day cycle. RESULT: During TMZ therapy, tumour...... staining for methylguanine DNA methyltransferase (MGMT) was negative in two patients (A and B), and in one patient (C) a few nuclei stained positive. CONCLUSION: TMZ therapy significantly decreased tumour volume, hormone hypersecretion and symptoms in all three patients, corresponding to the pathological...... findings regarding MGMT. TMZ therapy may be a new option for the treatment of resistant pituitary adenomas....

  10. A model for evaluating steroids acting at the hypothalamus-pituitary axis using radioimmunoassay and related procedures

    International Nuclear Information System (INIS)

    Relative affinity constants for binding of estrone (E1), estriol (E3), 17β-estradiol (E2) and 17α-ethinyl-17β-estradiol (EE2) to cytosol estrogen-receptor of rat hypothalamus and pituitary were estimated by radioligand-receptor assays. Relative affinity constants in the hypothalamic system were 6.5 x 10-1M for E2, 1 x 10-9M for EE2 and 2 x 10-8M for E1 and E3, respectively. The affinity constants were 1 x 10-9M for E2 and E3 and 7 x 10-9M for E1 and E3, resp., when pituitary cytosol samples were used. Some discrepancies between biological activity and affinity for the estrogen-receptor was noted, which may be due to differences in the metabolisms and cellular uptake of the estrogens. The present system may be also a useful procedure to help to provide a good definition of estrogen and anti-estroegn acting at the hypothalamic and pituitary level. Sedimentation patterns of cytosol samples labeled with estrogens used in this study revealed protein moieties sedimenting upon ultracentrifugation in the 8 S region. (orig.)

  11. Crosstalk properties of the CMS HCAL hybrid photodiode

    CERN Document Server

    Cushman, P B; Pearson, N; Elias, J; Freeman, J; Green, D; Los, S; Ronzhin, A

    2003-01-01

    The requirements of large dynamic range, 40 MHz readout and 4T magnetic field of the CMS Hadronic calorimeter have led to the development of a custom Hybrid PhotoDiode (HPD). In the last 5 years many improvements have been made in cooperation with DEP B.V. Delft Electronische Producten, Roden, Netherlands. and Canberra Semiconductor N.V., Olen, Belgium. to the basic HPD concept to improve the performance. A 200-mum thick 19-channel PIN diode array with various surface treatments has been developed to ensure fast pulse behavior and low optical and capacitive crosstalk.

  12. Gamma knife radiosurgery for secreting pituitary tumors

    Energy Technology Data Exchange (ETDEWEB)

    Noren, G. [Brown Univ., Providence, RI (United States). Rhode Island Hospital; Jackson, I.M.D.; Chougule, P.; Zheng, Z.; Epstein, M.H.

    1998-09-01

    Transsphenoidal surgery usually represents first line treatment for pituitary adenomas with the aim of removing the tumor, decompressing the optic apparatus and, in secreting tumors, eliminating the hypersecretion. Gamma Knife radiosurgery is indicated for tumor remnants or recurrences in or above the sella including those invading the cavernous sinus and also as initial treatment in patients who are unable to tolerate an open surgical procedure and where medication has failed. In this study, the target definition was retrospectively studied and when necessary corrected in 10 acromegalic patients, 8 with Cushing`s disease, and 12 with prolactinomas undergoing Gamma Knife radiosurgery. The dose plan was analyzed and the volume of the target covered by a minimum of 15, 20, 25, 30 and 35 Gy was estimated. A dose/volume profile for each treatment was created and correlated to the endocrinological and clinical outcome. Cure, according to strict endocrinological criteria, was seen in 6 of the acromegalic patients, in 2 of the patients with ACTH hypersecretion, and in 2 of the patients with prolactinomas. Analysis of these profiles, also for the patients with partial effect, show that a minimum radiation dose of 20 Gy may be adequate to eliminate the hypersecretion in acromegalic patients whereas a dose of at least 25 Gy may be required in patients with Cushing`s disease and prolactinoma. (author)

  13. Gamma knife radiosurgery for secreting pituitary tumors

    International Nuclear Information System (INIS)

    Transsphenoidal surgery usually represents first line treatment for pituitary adenomas with the aim of removing the tumor, decompressing the optic apparatus and, in secreting tumors, eliminating the hypersecretion. Gamma Knife radiosurgery is indicated for tumor remnants or recurrences in or above the sella including those invading the cavernous sinus and also as initial treatment in patients who are unable to tolerate an open surgical procedure and where medication has failed. In this study, the target definition was retrospectively studied and when necessary corrected in 10 acromegalic patients, 8 with Cushing's disease, and 12 with prolactinomas undergoing Gamma Knife radiosurgery. The dose plan was analyzed and the volume of the target covered by a minimum of 15, 20, 25, 30 and 35 Gy was estimated. A dose/volume profile for each treatment was created and correlated to the endocrinological and clinical outcome. Cure, according to strict endocrinological criteria, was seen in 6 of the acromegalic patients, in 2 of the patients with ACTH hypersecretion, and in 2 of the patients with prolactinomas. Analysis of these profiles, also for the patients with partial effect, show that a minimum radiation dose of 20 Gy may be adequate to eliminate the hypersecretion in acromegalic patients whereas a dose of at least 25 Gy may be required in patients with Cushing's disease and prolactinoma. (author)

  14. Diagnosis of pituitary adenoma with dynamic MRI

    International Nuclear Information System (INIS)

    Seventeen patients with pituitary adenomas topographically diagnosed by dynamic MRI between 1990 and 1995 are analyzed in this study. All patients were treated surgically and diagnosed pathologically. In all eight cases of macroadenomas, not only the normal glands, but also the adenomas were enhanced by Gd-DTPA (gadolinium diethylenetriamine pentaacetic acid). In three of eight cases, the normal glands could not be delineated, even by dynamic MRI. In five cases, the normal gland was recognized as an early enhancing area. In four of nine cases of microadenomas, the tumor was identified as a well-defined round area that enhanced later than normal tissue. In four other cases, a delayed enhancing area was vaguely dectable and proved to be the adenoma by histopathology. One of these cases was an ACTH producing adenoma. In the remaining case, three dynamic MRI study was performed, but no tumor was recognized preoperatively. This tumor was also an ACTH producing adenoma. These results suggest that, even by the dynamic MRI, sometimes the normal gland is not distinguishable from macroadenomas and furthermore, ACTH producing adenomas are still difficulty to diagnose preoperatively. (author)

  15. Cellular Kinetics of Perivascular MSC Precursors

    Directory of Open Access Journals (Sweden)

    William C. W. Chen

    2013-01-01

    Full Text Available Mesenchymal stem/stromal cells (MSCs and MSC-like multipotent stem/progenitor cells have been widely investigated for regenerative medicine and deemed promising in clinical applications. In order to further improve MSC-based stem cell therapeutics, it is important to understand the cellular kinetics and functional roles of MSCs in the dynamic regenerative processes. However, due to the heterogeneous nature of typical MSC cultures, their native identity and anatomical localization in the body have remained unclear, making it difficult to decipher the existence of distinct cell subsets within the MSC entity. Recent studies have shown that several blood-vessel-derived precursor cell populations, purified by flow cytometry from multiple human organs, give rise to bona fide MSCs, suggesting that the vasculature serves as a systemic reservoir of MSC-like stem/progenitor cells. Using individually purified MSC-like precursor cell subsets, we and other researchers have been able to investigate the differential phenotypes and regenerative capacities of these contributing cellular constituents in the MSC pool. In this review, we will discuss the identification and characterization of perivascular MSC precursors, including pericytes and adventitial cells, and focus on their cellular kinetics: cell adhesion, migration, engraftment, homing, and intercellular cross-talk during tissue repair and regeneration.

  16. MR imaging of pituitary hyperplasia in a child with growth arrest and primary hypothyroidism

    International Nuclear Information System (INIS)

    Magnetic resonance imaging of pituitary hyperplasia has been rarely described in children with primary hypothyroidism. We report a case of pituitary hyperplasia in a child presented with significant growth arrest and laboratory evidence of hypothyroidism. Magnetic resonance imaging revealed symmetrical pituitary enlargement simulating macroadenoma. After thyroid hormone replacement therapy, the child's height increased and pituitary enlargement regressed to normal. Awareness of MRI appearance of pituitary hyperplasia in children with laboratory evidence of hypothyroidism might avoid misdiagnosis for pituitary tumor, which may also manifest as growth disorder, obviating unnecessary surgery. (orig.)

  17. Expression pattern of the Hedgehog signaling pathway in pituitary adenomas.

    Science.gov (United States)

    Yavropoulou, Maria P; Maladaki, Anna; Topouridou, Konstantina; Kotoula, Vasiliki; Poulios, Chris; Daskalaki, Emily; Foroglou, Nikolaos; Karkavelas, George; Yovos, John G

    2016-01-12

    Several studies have demonstrated the role of Wnt and Notch signaling in the pathogenesis of pituitary adenomas, but data are scarce regarding the role of Hedgehog signaling. In this study we investigated the differential expression of gene targets of the Hedgehog signaling pathway. Formalin-fixed, paraffin-embedded specimens from adult patients who underwent transphenoidal resection and normal human pituitary tissues that were obtained from autopsies were used. Clinical information and data from pre-operative MRI scan (extracellular tumor extension, tumor size, displacement of the optic chiasm) were retrieved from the Hospital's database. We used a customized RT(2) Profiler PCR Array, to investigate the expression of genes related to Notch and Hedgehog signaling pathways (PTCH1, PTCH2, GLI1, GLI3, NOTCH3, JAG1, HES1, and HIP). A total of 52 pituitary adenomas (32 non-functioning adenomas, 15 somatotropinomas and 5 prolactinomas) were used in the final analysis. In non-functioning pituitary adenomas there was a significant decrease (approximately 75%) in expression of all Hedgehog related genes that were tested, while Notch3 and Jagged-1 expression was found significantly increased, compared with normal pituitary tissue controls. In contrast, somatotropinomas demonstrated a significant increase in expression of all Hedgehog related genes and a decrease in the expression of Notch3 and Jagged-1. There was no significant difference in the expression of Hedgehog and Notch related genes between prolactinomas and healthy pituitary tissues. Hedgehog signalling appears to be activated in somatotropinomas but not in non-functioning pituitary adenomas in contrast to the expression pattern of Notch signalling pathway. PMID:26620835

  18. Radioimmunoassay for determination of alpha subunit of pituitary glycoprotein hormones in patients with pituitary tumors

    International Nuclear Information System (INIS)

    A radioimmunoassay method for alpha subunit has been described and applied for serum alpha subunit determinations in normal subjects and 71 patients with pituitary tumors /45 acromegalic and 26 non-acromegalic/. The labelling of alpha subunit by the chloramine T technique yielded 125I-alpha subunit of high specific activity and high immuno-reactivity. Three purification methods of labelled 125I-alpha subunit were compared; the best separation of undamaged 125I-alpha subunit from impurities was achieved by gel filtration on Ultrogel AcA54 column, whereas gel filtration on Sephadex G-100 and adsorption chromatography on CF-11 cellulose gave less satisfactory results. Microheterogenity of 125I-alpha subunit was disclosed by chromatofocusing on PBE 94; the fractions of high immunoreactivitiy had isoelectric points of 6.0, 5.5 and 4.8. In normal subjects, radioimmunoassay of alpha subunit gave the following results /mean and SD/: 0.75 ng/ml +- 0.41 in males and 0.80 ng/ml +- 0.39 in females in reproductive age. In 9 acromegalic serum alpha subunit concentration were elevated up to 21 ng/ml, and in 8 non-acromegalic up to 30 ng/ml. One woman with acromegaly and high serum alpha subunit concentration had also elevated serum TSH associated with hyperthyroids. Our results disclosed that high serum alpha subunit concentration occurs in 25 % of patients with pituitary adenomas. (Author)

  19. MRI of the liver and the pituitary gland in patients with {beta}-thalassemia major: Does hepatic siderosis predict pituitary iron deposition?

    Energy Technology Data Exchange (ETDEWEB)

    Argyropoulou, Maria I.; Efremidis, Stavros C. [Department of Radiology, Medical School, University of Ioannina, 45110 Ioannina (Greece); Kiortsis, Dimitrios N. [Laboratory of Physiology, Medical School, University of Ioannina, 45110 Ioannina (Greece)

    2003-01-01

    Our objective was to study, in thalassemic patients, if hepatic siderosis evaluated by MRI could predict the pituitary iron overload. In 36 thalassemic patients (age range 6-44 years, mean age 21.7 years) the liver/fat ratio (L/F), the pituitary/fat ratio (P/F), the liver and pituitary T2 relaxation times were evaluated, by using a multiecho spin-echo sequence. Serum ferritin levels were measured and an extensive endocrine evaluation was performed. The L/F, the P/F and pituitary T2 showed a good correlation with serum ferritin (r=-0.55, r=-0.55 and r=-0.53, respectively; p<0.01). Liver T2 did not show significant correlation with serum ferritin. The variability of L/F explained only the 10.8% of the variability of pituitary T2 and of the P/F. When ferritin was added to the model it predicted only the 26.85% and the 30.8% of the variability of pituitary T2 and of the P/F, respectively. The P/F and pituitary T2 were lower in patients with hypogonadotropic hypogonadism (group 1) compared with those without pituitary dysfunction (group 2). No significant differences of L/F were found between the two groups. Hepatic iron overload evaluated by MR is a poor predictor of pituitary siderosis. The MR studies of the pituitary gland might be necessary to evaluate the pituitary iron overload. (orig.)

  20. Systematic Analysis of the Crosstalk between Mitosis and DNA Damage by a Live Cell siRNA Screen

    DEFF Research Database (Denmark)

    Pedersen, Ronni Sølvhøi

    Recent research has shown, that the biological processes of DNA replication, DNA damage, cell cycle and mitosis cannot be considered as isolated cellular functions but are mechanistically linked in many ways. For instance, when cells are exposed to replication stress and enter mitosis with...... unresolved replication intermediates, it can give rise to chromosome lesions, which are then transmitted to the next cell cycle. Aberrations in the mitotic process itself can potentially give rise to post-mitotic DNA damage with serious onsequences for genome integrity in the ensuing cell generations. The...... relative proportion and crosstalk between these causative versus consequent genome-destabilizing events remains elusive. The aim of this thesis was to assess the relationship between DNA damage and mitotic perturbations. Using large-scale, real-time siRNA screens and a live cell imaging approach...

  1. Understanding the complexities of Salmonella-host crosstalk as revealed by in vivo model organisms.

    Science.gov (United States)

    Verma, Smriti; Srikanth, Chittur V

    2015-07-01

    Foodborne infections caused by non-typhoidal Salmonellae, such as Salmonella enterica serovar Typhimurium (ST), pose a major challenge in the developed and developing world. With constant rise of drug-resistant strains, understanding the epidemiology, microbiology, pathogenesis and host-pathogen interactions biology is a mandatory requirement to enable health systems to be ready to combat these illnesses. Patient data from hospitals, at least from some parts of the world, have aided in epidemiological understanding of ST-mediated disease. Most of the other aspects connected to Salmonella-host crosstalk have come from model systems that offer convenience, genetic tractability and low maintenance costs that make them extremely valuable tools. Complex model systems such as the bovine model have helped in understanding key virulence factors needed for infection. Simple systems such as fruit flies and Caenorhabditis elegans have aided in identification of novel virulence factors, host pathways and mechanistic details of interactions. Some of the path-breaking concepts of the field have come from mice model of ST colitis, which allows genetic manipulations as well as high degree of similarity to human counterpart. Together, they are invaluable for correlating in vitro findings of ST-induced disease progression in vivo. The current review is a compilation of various advances of ST-host interactions at cellular and molecular levels that has come from investigations involving model organisms. PMID:26179888

  2. Cannabinoid-hypocretin cross-talk in the central nervous system: what we know so far

    Directory of Open Access Journals (Sweden)

    África eFlores

    2013-12-01

    Full Text Available Emerging findings suggest the existence of a cross-talk between hypocretinergic and endocannabinoid systems. Although few studies have examined this relationship, the apparent overlap observed in the neuroanatomical distribution of both systems as well as their putative functions strongly point to the existence of such cross-modulation. In agreement, biochemical and functional studies have revealed the existence of heterodimers between CB1 cannabinoid receptor and hypocretin receptor-1, which modulates the cellular localization and downstream signalling of both receptors. Moreover, the activation of hypocretin receptor-1 stimulates the synthesis of 2-arachidonoyl glycerol culminating in the retrograde inhibition of neighbouring cells and suggesting that endocannabinoids could contribute to some hypocretin effects. Pharmacological data indicate that endocannabinoids and hypocretins might have common physiological functions in the regulation of appetite, reward and analgesia. In contrast, these neuromodulatory systems seem to play antagonistic roles in the regulation of sleep/wake cycle and anxiety-like responses. The present review attempts to piece together what is known about this interesting interaction and describe its potential therapeutic implications.

  3. The Regulatory Role of Signaling Crosstalk in Hypertrophy of MSCs and Human Articular Chondrocytes

    Directory of Open Access Journals (Sweden)

    Leilei Zhong

    2015-08-01

    Full Text Available Hypertrophic differentiation of chondrocytes is a main barrier in application of mesenchymal stem cells (MSCs for cartilage repair. In addition, hypertrophy occurs occasionally in osteoarthritis (OA. Here we provide a comprehensive review on recent literature describing signal pathways in the hypertrophy of MSCs-derived in vitro differentiated chondrocytes and chondrocytes, with an emphasis on the crosstalk between these pathways. Insight into the exact regulation of hypertrophy by the signaling network is necessary for the efficient application of MSCs for articular cartilage repair and for developing novel strategies for curing OA. We focus on articles describing the role of the main signaling pathways in regulating chondrocyte hypertrophy-like changes. Most studies report hypertrophic differentiation in chondrogenesis of MSCs, in both human OA and experimental OA. Chondrocyte hypertrophy is not under the strict control of a single pathway but appears to be regulated by an intricately regulated network of multiple signaling pathways, such as WNT, Bone morphogenetic protein (BMP/Transforming growth factor-β (TGFβ, Parathyroid hormone-related peptide (PTHrP, Indian hedgehog (IHH, Fibroblast growth factor (FGF, Insulin like growth factor (IGF and Hypoxia-inducible factor (HIF. This comprehensive review describes how this intricate signaling network influences tissue-engineering applications of MSCs in articular cartilage (AC repair, and improves understanding of the disease stages and cellular responses within an OA articular joint.

  4. Tuning the material-cytoskeleton crosstalk via nanoconfinement of focal adhesions.

    Science.gov (United States)

    Natale, Carlo F; Ventre, Maurizio; Netti, Paolo A

    2014-03-01

    Material features proved to exert a potent influence on cell behaviour in terms of adhesion, migration and differentiation. In particular, biophysical and biochemical signals on material surfaces are able to affect focal adhesion distribution and cytoskeletal assemblies, which are known to regulate signalling pathways that ultimately influence cell fate and functions. However, a general, unifying model that correlates cytoskeletal-generated forces with genetic events has yet to be developed. Therefore, it is crucial to gain a better insight into the material-cytoskeleton crosstalk in order to design and fabricate biomaterials able to govern cell fate more accurately. In this work, we demonstrate that confining focal adhesion distribution and growth dramatically alters the cytoskeleton's structures and dynamics, which in turn dictate cellular and nuclear shape and polarization. MC3T3 preosteoblasts were cultivated on nanograted polydimethylsiloxane substrates and a thorough quantification - in static and dynamic modes - of the morphological and structural features of focal adhesions and cytoskeleton was performed. Nanoengineered surfaces provided well-defined zones for focal adhesions to form and grow. Unique cytoskeletal structures spontaneously assembled when focal adhesions were confined and, in fact, they proved to be very effective in deforming the nuclei. The results here presented provide elements to engineer surfaces apt to guide and control cell behaviour through the material-cytoskeleton-nucleus axis. PMID:24388800

  5. A Glutathione-Nrf2-Thioredoxin Cross-Talk Ensures Keratinocyte Survival and Efficient Wound Repair.

    Science.gov (United States)

    Telorack, Michèle; Meyer, Michael; Ingold, Irina; Conrad, Marcus; Bloch, Wilhelm; Werner, Sabine

    2016-01-01

    The tripeptide glutathione is the most abundant cellular antioxidant with high medical relevance, and it is also required as a co-factor for various enzymes involved in the detoxification of reactive oxygen species and toxic compounds. However, its cell-type specific functions and its interaction with other cytoprotective molecules are largely unknown. Using a combination of mouse genetics, functional cell biology and pharmacology, we unraveled the function of glutathione in keratinocytes and its cross-talk with other antioxidant defense systems. Mice with keratinocyte-specific deficiency in glutamate cysteine ligase, which catalyzes the rate-limiting step in glutathione biosynthesis, showed a strong reduction in keratinocyte viability in vitro and in the skin in vivo. The cells died predominantly by apoptosis, but also showed features of ferroptosis and necroptosis. The increased cell death was associated with increased levels of reactive oxygen and nitrogen species, which caused DNA and mitochondrial damage. However, epidermal architecture, and even healing of excisional skin wounds were only mildly affected in the mutant mice. The cytoprotective transcription factor Nrf2 was strongly activated in glutathione-deficient keratinocytes, but additional loss of Nrf2 did not aggravate the phenotype, demonstrating that the cytoprotective effect of Nrf2 is glutathione dependent. However, we show that deficiency in glutathione biosynthesis is efficiently compensated in keratinocytes by the cysteine/cystine and thioredoxin systems. Therefore, our study highlights a remarkable antioxidant capacity of the epidermis that ensures skin integrity and efficient wound healing. PMID:26808544

  6. The cross-talk between enterocytes and intraepithelial lymphocytes.

    Science.gov (United States)

    Vitale, Serena; Picascia, Stefania; Gianfrani, Carmen

    2016-12-01

    The gut mucosa is continuously exposed to food and microbial antigens. Both enterocytes and intraepithelial lymphocytes have a pivotal role in maintaining the integrity of intestinal mucosa, as these cells guarantee a first line of defense against pathogens and toxic molecules. Enterocytes maintain a physical barrier against microbes and directly contribute to the gut homeostasis by sampling the luminal agents through several pattern recognition receptors or presenting antigen to mucosa T cells. Similarly, due to a close physical contact with the intestinal epithelial cells, the intraepithelial lymphocytes represent an important part of the gut lymphoid tissue, contrasting the entry and spread of pathogens. An alteration of the cross-talk between intestinal epithelial cells and intraepithelial lymphocytes might actively contribute to the development of intestinal immune disorders, as occurring in patients with celiac disease. In genetically predisposed individuals, the gluten exposure results in a massive production of interleukin-15, activation of intraepithelial lymphocytes, and modification of small intestinal mucosa architecture and function. We will review the recent studies on the pathophysiology of cross-talk between enterocytes and intraepithelial T cells, and how this interaction is crucial for intestinal integrity and homeostasis. PMID:27251606

  7. Bus Encoder for Crosstalk Avoidance in RLC Modeled Interconnects

    Directory of Open Access Journals (Sweden)

    S.K.Verma

    2012-04-01

    Full Text Available The performance factors such as propagation delay, power dissipation and cross talk in RC modelled interconnects are major design issues for the System on-chip (SoC designs in current Deep Sub micron (DSM era. The crosstalk effect is a consequence of coupling and switching activities that is encountered when there is a transition as compared to previous state of wire and or when there are transitions in adjacent wires. Therefore, minimization or elimination of switching and coupling activities is crucial in enhancing the performance of SoC designs. There are several methods for the reduction of power dissipation, crosstalk and delay. The encoding method is most effective and popular method for enhancing the behaviour of on-chip buses. This paper proposes encoding scheme to achieve overall reduction in transitions. The reduction in transition improves the performance in terms of reduced power dissipation, coupling activity and delay in on-chip buses. This encoding method is implemented using VHDL. The result evidently demonstrates reduction in transitions which consequently improves the overall performance of on-chip buses.

  8. Immune-epithelial crosstalk at the intestinal surface.

    Science.gov (United States)

    Wittkopf, Nadine; Neurath, Markus F; Becker, Christoph

    2014-03-01

    The intestinal tract is one of the most complex organs of the human body. It has to exercise various functions including food and water absorption, as well as barrier and immune regulation. These functions affect not only the gut itself, but influence the overall health of the organism. Diseases involving the gastrointestinal tract such as inflammatory bowel disease and colorectal cancer therefore severely affect the patient's quality of life and can become life-threatening. Intestinal epithelial cells (IECs) play an important role in intestinal inflammation, infection, and cancer development. IECs not only constitute the first barrier in the gut against the lumen, they also constantly signal information about the gut lumen to immune cells, thereby influencing their behaviour. In contrast, by producing various antimicrobial peptides, IECs shape the microbial community within the gut. IECs also respond to cytokines and other mediators of immune cells in the lamina propria. Interactions between epithelial cells and immune cells in the intestine are responsible for gut homeostasis, and modulations of this crosstalk have been reported in studies of gut diseases. This review discusses the wide field of immune-epithelial interactions and shows the importance of immune-epithelial crosstalk in the intestine to gut homeostasis and the overall health status. PMID:24469679

  9. A new design of MRPC to reduce noise and crosstalk

    Science.gov (United States)

    Weiping, Z.; Yi, W.; Yuanjing, L.; Jianping, C.

    2014-07-01

    The CBM time of flight wall is proposed to be built with MRPC technology. In the past few years we have successfuly improved the rate capability of MRPCs to CBM level. However, in a relative high particle multiplicity situation (over 20 kHz/cm2), multi-hit capability is one of the most demanding requirement of the detector. In a free running mode too many noise not only affect the performance of MRPC but also enlarge the data file or even damage the FIFO. So it is needed to develop low crosstalk and low noise MRPC to meet CBM-TOF requirement. Three strip-readout MRPC with or without shielding grounds were designed to study how to reduce noise and crosstalk of MRPCs. In this paper we report on the performance of three different structures of MRPCs named G-0, G-2 and G-3. Tests with cosmic rays were performed at Tsinghua University. The results show that MRPC G-2 can perform better than other two structures, the average cluster size of G-2 is lower than 1.28 strips and the noise level is below 0.5 Hz/cm2. The detection efficiency is over 98% and the time resolution is around 65 ps.

  10. Embryonic–maternal cross-talk via exosomes: potential implications

    Directory of Open Access Journals (Sweden)

    Saadeldin IM

    2015-07-01

    Full Text Available Islam M Saadeldin,1 Hyun Ju Oh,2 Byeong Chun Lee2,3 1Department of Physiology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Egypt; 2Department of Theriogenology and Biotechnology, College of Veterinary Medicine and the Research Institute for Veterinary Science, Seoul National University, Seoul, Republic of Korea; 3Institute of Green Bio Science and Technology, Seoul National University, Pyeong Chang, Kangwon do, Republic of KoreaAbstract: A myriad of locally produced factors into the microenvironment of the reproductive tract is regulated, not one-way but rather, through embryonic–maternal cross-talk. In this minireview, we focused on the exosomes, which are cell-derived vesicles of 30–100 nm in diameter, as a communicating language facilitating this dialog. These nanovesicles are secreted from preimplantation embryos, oviduct epithelium, and endometrium as well as from the placenta, and contain proteins, messenger RNA (mRNA, microRNA, and DNA cargoes, and have pleiotropic effects on both embryonic and maternal environments. A better understanding of the molecular mechanisms mediating this cross-talk will lead to the development of new regulating agents, with novel diagnostic, biological, and therapeutic potential for either supporting or hindering the normal reproductive functions. Keywords: embryo, endometrium, placenta, mRNA, miRNA

  11. Elimination or minimisation of optoelectronic crosstalk between photodiodes and electronic devices in OEIC on Si

    NARCIS (Netherlands)

    Zhou, M.-J.; Holleman, J.; Wallinga, H.

    1994-01-01

    The optoelectronic crosstalk between photodiodes and electronic devices is observed and investigated in OEICs based on silicon. Results show that the phenomenon is closely related to the diffusion of minority carriers, generated by photon absorption. The crosstalk can be eliminated or minimised by e

  12. Crosstalk in 1.5-μm InGaAsP optical amplifiers

    DEFF Research Database (Denmark)

    Lassen, H. E.; Hansen, Peter Bukhave; Stubkjær, Kristian

    1988-01-01

    A dynamical model for multichannel amplification by near-traveling-wave optical amplifiers is presented, and results on crosstalk induced by either amplitude modulation or frequency modulation are given. The mechanisms influencing the crosstalk most are the residual facet reflectivities and the...

  13. Review of the crosstalk in the module 0 of the Electromagnetic Endcap Calorimeter

    CERN Document Server

    Pralavorio, Pascal

    2001-01-01

    This note presents a complete crosstalk map of the endcap calorimeter module 0. Results on test benches performed on mother boards (old and new), proven to be responsible of most of the crosstalk in Middle and Back samplings, are also shown.

  14. Reduction of crosstalk on printed circuit board using genetic algorithm in switching power supply

    OpenAIRE

    Pong, MH; Wu, X; Lee, CM; Qian, Z.

    2001-01-01

    Crosstalk between printed circuit board (PCB) traces in switching power supplies may cause high electromagnetic interference emission. PCB layout plays an important part and a genetic algorithm (GA) is used to produce a layout with reduced crosstalk. A coupling index and a new way of representing a trace for the GA process is presented.

  15. Crosstalk and Wire Length Reduction in the Non-Manhattan Channel Routing

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel framework for non-Manhattan channel routing considering crosstalk and wire length reduction is proposed. To handle crosstalk and wire length reduction problem, an improved non-Manhattan router in the gridded routing model is developed, and a novel rerouting algorithm based on segment-rerouting technique and layer reassignment is presented. Simulation experiments demonstrate that our algorithm achieves very good results.

  16. Decreased expression of APAF-1 and increased expression of cathepsin B in invasive pituitary adenoma

    Directory of Open Access Journals (Sweden)

    Tanase C

    2014-12-01

    Full Text Available Cristiana Tanase,1 Radu Albulescu,1,2 Elena Codrici,1 Bogdan Calenic,1,3 Ionela Daniela Popescu,1 Simona Mihai,1 Laura Necula,1,4 Maria Linda Cruceru,5 Mihail Eugen Hinescu1,5 1“Victor Babes” National Institute of Pathology, Biochemistry-Proteomics Department, 2National Institute for Chemical Pharmaceutical R&D, 3“Carol Davila” University of Medicine and Pharmacy, Department of Biochemistry, 4Stefan S. Nicolau Institute of Virology, Cellular and Molecular Pathology, 5“Carol Davila” University of Medicine and Pharmacy, Cellular and Molecular Medicine Department, Bucharest, Romania Purpose: Apoptotic protease-activating factor-1 (APAF-1 and cathepsin B are important functional proteins in apoptosis; the former is involved in the intrinsic (mitochondrial pathway, while the latter is associated with both intrinsic and extrinsic pathways. Changes in the expression of apoptosome-related proteins could be useful indicators of tumor development since a priori defects in the mitochondrial pathway might facilitate the inception and progression of human neoplasms. Our aim was to evaluate the profiles of APAF-1 and cathepsin B in relation with other molecules involved in apoptosis/proliferation and to correlate them with the aggressive behavior of invasive pituitary adenomas. Materials and methods: APAF-1 and cathepsin B were assessed in tissue samples from 30 patients with pituitary adenomas, of which 16 were functional adenomas and 22 were invasive adenomas. Results: A positive relationship between high proliferation and invasiveness was observed in invasive pituitary adenomas when compared to their noninvasive counterparts (Ki-67 labeling index – 4.72% versus 1.75%. Decreased expression of APAF-1 was recorded in most of the invasive adenomas with a high proliferation index, while the cathepsin B level was elevated in this group. We have noticed a negative correlation between the low level of APAF-1 and invasiveness (63.63%; P<0.01; at the

  17. Technetium-99m pentavalent dimercaptosuccinic acid imaging for pituitary adenomas

    International Nuclear Information System (INIS)

    The authors performed scintigraphy using 99mTc(V)-DMSA (Technetium-99m pentavalent dimercaptosuccinic acid) on patients with pituitary adenomas. Three non-functioning (100%), 2 GH-secreting (67%), 4 PRL-secreting (80%), and zero ACTH-secreting (0%) adenomas concentrated the 99mTc(V)-DMSA, but all 5 of the non-adenomatous lesions and 1 normal pituitary gland did not. There was no significant relationship between tumor-to-background ratios and tumor sizes, or the serum hormone level. The 99mTc(V)-DMSA scintigraphy showed an overall sensitivity of 69% (9/13) in detecting pituitary adenomas, which increased to 82% for non-functioning, GH-secreting and PRL-secreting adenomas. In conclusions, 99mTc(V)-DMSA was found to be a suitable radiotracer for detecting pituitary adenomas. But further studies are necessary to define the processes that concentrate 99mTc(V)-DMSA and their role in pituitary adenomas. (author)

  18. Fractionated stereotactic radiotherapy in the treatment of pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, C.; Theodorou, M.; Poullos, N.; Astner, S.T.; Geinitz, H.; Molls, M. [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Klinik und Poliklinik fuer Strahlentherapie und Radiologische Onkologie; Stalla, G.K. [Max-Planck-Institut fuer Psychiatrie, Muenchen (Germany). Klinische Neuroendokrinologie; Meyer, B. [Technische Univ. Muenchen, Klinikum rechts der Isar (Germany). Neurochirurgische Klinik und Poliklinik; Nieder, C. [Nordland Hospital, Bodoe (Norway). Dept. of Oncology and Palliative Medicine; Tromsoe Univ. (Norway). Inst. of Clinical Medicine; Grosu, A.L [Freiburg Univ. (Germany). Klinik fuer Strahlenheilkunde

    2013-11-15

    Purpose: The purpose of this work was to evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent pituitary adenomas. Patients and methods: We report on 37 consecutive patients with pituitary adenomas treated with FSRT at our department. All patients had previously undergone surgery. Twenty-nine patients had nonfunctioning, 8 had hormone-producing adenoma. The mean total dose delivered by a linear accelerator was 49.4 Gy (range 45-52.2 Gy), 5 x 1.8 Gy weekly. The mean PTV was 22.8 ccm (range 2.0-78.3 ccm). Evaluation included serial imaging tests, endocrinologic and ophthalmologic examination. Results: Tumor control was 91.9 % for a median follow-up time of 57 months (range 2-111 months). Before FSRT partial hypopituitarism was present in 41 % of patients, while 35 % had anterior panhypopituitarism. After FSRT pituitary function remained normal in 22 %, 43 % had partial pituitary dysfunction, and 35 % had anterior panhypopituitarism. Visual acuity was stable in 76 % of patients, improved in 19 %, and deteriorated in 5 %. Visual fields remained stable in 35 patients (95 %), improved in one and worsened in 1 patient (2.7 %). Conclusion: FSRT is an effective and safe treatment for recurrent or residual pituitary adenoma. Good local tumor control and preservation of adjacent structures can be reached, even for large tumors. (orig.)

  19. Fractionated stereotactic radiotherapy in the treatment of pituitary adenomas

    International Nuclear Information System (INIS)

    Purpose: The purpose of this work was to evaluate tumor control and side effects associated with fractionated stereotactic radiotherapy (FSRT) in the management of residual or recurrent pituitary adenomas. Patients and methods: We report on 37 consecutive patients with pituitary adenomas treated with FSRT at our department. All patients had previously undergone surgery. Twenty-nine patients had nonfunctioning, 8 had hormone-producing adenoma. The mean total dose delivered by a linear accelerator was 49.4 Gy (range 45-52.2 Gy), 5 x 1.8 Gy weekly. The mean PTV was 22.8 ccm (range 2.0-78.3 ccm). Evaluation included serial imaging tests, endocrinologic and ophthalmologic examination. Results: Tumor control was 91.9 % for a median follow-up time of 57 months (range 2-111 months). Before FSRT partial hypopituitarism was present in 41 % of patients, while 35 % had anterior panhypopituitarism. After FSRT pituitary function remained normal in 22 %, 43 % had partial pituitary dysfunction, and 35 % had anterior panhypopituitarism. Visual acuity was stable in 76 % of patients, improved in 19 %, and deteriorated in 5 %. Visual fields remained stable in 35 patients (95 %), improved in one and worsened in 1 patient (2.7 %). Conclusion: FSRT is an effective and safe treatment for recurrent or residual pituitary adenoma. Good local tumor control and preservation of adjacent structures can be reached, even for large tumors. (orig.)

  20. Reformatted CT diagnosis of pituitary microadenomas in hyperprolactinemic women

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Tetsuya; Kikuchi, Kenji; Kowada, Masayoshi; Hariu, Mineko; Miyauchi, Koji (Akita Univ. (Japan))

    1983-06-01

    The CT diagnosis of pituitary microadenomas was made in 13 among 20 female sterile patients with hyperprolactinemia, utilizing sagittal- and coronal-sectioned reformation on the basis of 1.5 mm-sliced high-resolution axial CT scanning. The pituitary stalk was found to have been shifted in 10 patients, and in all of them adenomas were verified. This was in contrast to the findings that, among another 10 patients with no definite evidence of the stalk shifting, only 3 patients had adenomas. Pituitary adenomas were present in 11 of the 12 patients demonstrating the pituitary surface in a ''convex'' fashion. In contrast, 2 among 6 patients with a ''flat'' surface demonstrated the presence of pituitary adenomas. Enhancement patterns in the sella could be classified as of four types: homogeneous, diffuse-low, punched-out, and nodular types. The adenomas tended to occur in either the nodular or diffuse-low type; they were less frequently seen in the punched-out or homogeneous type. With regard to the correlation between the patterns of contrast enhancement and the serum concentrations of prolactin, it may be of note that the nodular type corresponded well to the higher prolactin serum level, and the homogeneous type to the lower level.

  1. Reformatted CT diagnosis of pituitary microadenomas in hyperprolactinemic women

    International Nuclear Information System (INIS)

    The CT diagnosis of pituitary microadenomas was made in 13 among 20 female sterile patients with hyperprolactinemia, utilizing sagittal- and coronal-sectioned reformation on the basis of 1.5 mm-sliced high-resolution axial CT scanning. The pituitary stalk was found to have been shifted in 10 patients, and in all of them adenomas were verified. This was in contrast to the findings that, among another 10 patients with no definite evidence of the stalk shifting, only 3 patients had adenomas. Pituitary adenomas were present in 11 of the 12 patients demonstrating the pituitary suface in a ''convex'' fashion. In contrast, 2 among 6 patients with a ''flat'' surface demonstrated the presence of pituitary adenomas. Enhancement patterns in the sella could be classified as of four types: homogeneous, diffuse-low, punched-out, and nodular types. The adenomas tended to occur in either the nodular or diffuse-low type; they were less frequently seen in the punched-out or homogeneous type. With regard to the correlation between the patterns of contrast enhancement and the serum concentrations of prolactin, it may be of note that the nodular type corresponded well to the higher prolactin serum level, and the homogeneous type to the lower level. (author)

  2. Outcomes following Purely Endoscopic Endonasal Resection of Pituitary adenomas

    Directory of Open Access Journals (Sweden)

    Rezaul Amin

    2013-01-01

    Full Text Available Background: The use of endoscope for the management of pituitary adenoma is not new. The better magnification and illumination provided by the endoscope gives better outcome than microscopic pituitary surgery. Objective: To find out the benefits of endoscope in relation to microscopic surgery. Materials and Methods: We performed 45 cases of pituitary adenoma surgery by endoscopic endonasal approach from July 2008 to July 2010. Results: Forty five cases underwent endoscopic transsphenoidal approach. Gross total removal was done in 35 cases and subtotal removal was done in 10 cases. Residual tumours were seen in 10 cases (22% in postoperative follow-up MRI scan. Visual improvement was satisfactory, and hormonal improvement of functional adenoma was nice. Postoperative visual acuity and visual field were improved in 75% cases. There were 37% cases of temporary diabetes insipidus and about 4.5% cases of permanent diabetes insipidus. The average duration of follow-up was 20 months. One patient required reexploration to correct visual deterioration in the immediate postoperative period. There were 4.5% cases of CSF leak and 6.6% mortality. Mortality was due to electrolyte imbalance and improper management of infection and hydrocephalus. Conclusion: Endoscopic endonasal pituitary surgery now has become a gold standard surgery for most of the pituitary adenomas because of its better advantages in relation to microscopic surgery and less complications and less hospital stay.

  3. The clinical pathologic research of invasive pituitary adenomas

    International Nuclear Information System (INIS)

    Objective: To study the pathological morphologic characteristics of invasive pituitary tumor and the affect of vascularization to the tumor's invasion. Methods: One hundred and thirty cases of pituitary adenoma patients were divided into two groups, including invasive pituitary adenomas and non-invasive pituitary adenomas, and the clinical data of two groups were analysed and compared. Results : The difference was statistically significant between the invasive group and the non-invasive group in the incidence rate of pathological morphologic characteristics such as high nuclear cytoplasmic ratio, cell pleomorphism, nuclear atypia and nucleoli appearance (P<0.05); there were nuclear atypia and nucleolus margination in the invasive group through electron microscopy. And there was statistical significant difference in rate of MVD expression which was higher in the invasive group than that of noninvasive group (P<0.05). Conclusion: The pathological morphologic characteristics of pituitary tumor and the high expression of MVD are significantly reference valuable in tumor aggression diagnosis, which provides valuable indicators for early clinical diagnosis of tumor invasion. (authors)

  4. An RLC interconnect analyzable crosstalk model considering self-heating effect

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhang-Ming; Liu Shu-Bin

    2012-01-01

    According to the thermal profile of actual multilevel interconnects,in this paper we propose a temperature distribution model of multilevel interconnects and derive an analytical crosstalk model for the distributed resistanceinductance-capacitance (RLC) interconnect considering effect of thermal profile.According to the 65-nm complementary metal-oxide semiconductor (CMOS) process,we compare the proposed RLC analytical crosstalk model with the Hspice simulation results for different interconnect coupling conditions and the absolute error is within 6.5%.The computed results of the proposed analytical crosstalk model show that RCL crosstalk decreases with the increase of current density and increases with the increase of insulator thickness.This analytical crosstalk model can be applied to the electronic design automation (EDA) and the design optimization for nanometer CMOS integrated circuits.

  5. An RLC interconnect analyzable crosstalk model considering self-heating effect

    International Nuclear Information System (INIS)

    According to the thermal profile of actual multilevel interconnects, in this paper we propose a temperature distribution model of multilevel interconnects and derive an analytical crosstalk model for the distributed resistance—inductance—capacitance (RLC) interconnect considering effect of thermal profile. According to the 65-nm complementary metal—oxide semiconductor (CMOS) process, we compare the proposed RLC analytical crosstalk model with the Hspice simulation results for different interconnect coupling conditions and the absolute error is within 6.5%. The computed results of the proposed analytical crosstalk model show that RCL crosstalk decreases with the increase of current density and increases with the increase of insulator thickness. This analytical crosstalk model can be applied to the electronic design automation (EDA) and the design optimization for nanometer CMOS integrated circuits. (interdisciplinary physics and related areas of science and technology)

  6. Quantitative characterization of crosstalk effects for friction force microscopy with scan-by-probe SPMs.

    Science.gov (United States)

    Prunici, Pavel; Hess, Peter

    2008-06-01

    If the photodetector and cantilever of an atomic force microscope (AFM) are not properly adjusted, crosstalk effects will appear. These effects disturb measurements of the absolute vertical and horizontal cantilever deflections, which are involved in friction force microscopy (FFM). A straightforward procedure is proposed to study quantitatively crosstalk effects observed in scan-by-probe SPMs. The advantage of this simple, fast, and accurate procedure is that no hardware change or upgrade is needed. The results indicate that crosstalk effects depend not only on the alignment of the detector but also on the cantilever properties, position, and detection conditions. The measurements may provide information on the origin of the crosstalk effect. After determination of its magnitude, simple correction formulas can be applied to correct the crosstalk effects and then the single-load wedge method, using a commercially available grating, can be employed for accurate calibration of the lateral force. PMID:18035500

  7. Characterization and modeling of crosstalk and afterpulsing in Hamamatsu silicon photomultipliers

    CERN Document Server

    Rosado, Jaime

    2015-01-01

    The crosstalk and afterpulsing in Hamamatsu silicon photomultipliers, called Multi-Pixel Photon Counters (MPPCs), have been studied in depth. Several components of the correlated noise have been identified according to their different possible causes and their effects on the signal. In particular, we have distinguished between prompt and delayed crosstalk as well as between trap-assisted and hole-induced afterpulsing. The prompt crosstalk has been characterized through the pulse amplitude spectrum measured at dark conditions. The newest MPPC series, which incorporate isolating trenches between pixels, exhibit a very low prompt crosstalk, but a small component remains likely due to secondary photons reflected on the top surface of the device and photon-generated minority carriers diffusing in the silicon substrate. We present a meticulous procedure to characterize the afterpulsing and delayed crosstalk through the amplitude and delay time distributions of secondary pulses. Our results indicate that both noise ...

  8. Investigation of crosstalk in self oscillating switch mode audio power amplifier

    DEFF Research Database (Denmark)

    Birch, Thomas Haagen; Ploug, Rasmus Overgaard; Iversen, Niels Elkjær;

    2012-01-01

    Self oscillating switch mode power ampliers are known to be susceptible to interchannel disturbances also known as crosstalk. This phenomenon has a signicant impact on the performance of an amplier of this type. The goal of this paper is to investigate the presence and origins of crosstalk in a two...... channel self oscillating switch mode power amplier (class D). A step by step reduction of elements in an amplier built for this task, is used for methodically determining the actual presence and origins of crosstalk. The investigation shows that the crosstalk is caused by couplings in the self oscillating...... pulse width modulation circuits, but also that the output lter has a major impact on the level of crosstalk....

  9. Long-term drift induced by the electronic crosstalk in Terra MODIS Band 29

    Science.gov (United States)

    Sun, Junqiang; Madhavan, Sriharsha; Xiong, Xiaoxiong; Wang, Menghua

    2015-10-01

    Terra MODerate Resolution Imaging Spectroradiometer (MODIS) is one of the key sensors in the NASA's Earth Observing System, which has successfully completed 15 years of on-orbit operation. Terra MODIS continues to collect valuable information of the Earth's energy radiation from visible to thermal infrared wavelengths. The instrument has been well characterized over its lifetime using onboard calibrators whose calibration references are traceable to the National Institute of Standards and Technology standards. In this paper, we focus on the electronic crosstalk effect of Terra MODIS band 29, a thermal emissive band (TEB) whose center wavelength is 8.55 µm. Previous works have established the mechanism to describe the effect of the electronic crosstalk in the TEB channels of Terra MODIS. This work utilizes the established methodology to apply to band 29. The electronic crosstalk is identified and characterized using the regularly scheduled lunar observations. The moon being a near-pulse-like source allowed easy detection of extraneous signals around the actual Moon surface. First, the crosstalk-transmitting bands are identified along with their amplitudes. The crosstalk effect then is characterized using a moving average mechanism that allows a high fidelity of the magnitude to be corrected. The lunar-based analysis unambiguously shows that the crosstalk contamination is becoming more severe in recent years and should be corrected in order to maintain calibration quality for the affected spectral bands. Finally, two radiometrically well-characterized sites, Pacific Ocean and Libya 1 desert, are used to assess the impact of crosstalk effect. It is shown that the crosstalk contamination induces a long-term upward drift of 1.5 K in band 29 brightness temperature of MODIS Collection 6 L1B, which could significantly impact the science products. The crosstalk effect also induces strong detector-to-detector differences, which result in severe stripping in the Earth view

  10. Investigation and Mitigation of the Crosstalk Effect in Terra MODIS Band 30

    Directory of Open Access Journals (Sweden)

    Junqiang Sun

    2016-03-01

    Full Text Available It has been previously reported that thermal emissive bands (TEB 27–29 in the Terra (T- MODerate resolution Imaging Spectroradiometer (MODIS have been significantly affected by electronic crosstalk. Successful linear theory of the electronic crosstalk effect was formulated, and it successfully characterized the effect via the use of lunar observations as viable inputs. In this paper, we report the successful characterization and mitigation of the electronic crosstalk for T-MODIS band 30 using the same characterization methodology. Though the phenomena of the electronic crosstalk have been well documented in previous works, the novel for band 30 is the need to also apply electronic crosstalk correction to the non-linear term in the calibration coefficient. The lack of this necessity in early works thus demonstrates the distinct difference of band 30, and, yet, in the same instances, the overall correctness of the characterization formulation. For proper result, the crosstalk correction is applied to the band 30 calibration coefficients including the non-linear term, and also to the earth view radiance. We demonstrate that the crosstalk correction achieves a long-term radiometric correction of approximately 1.5 K for desert targets and 1.0 K for ocean scenes. Significant striping removal in the Baja Peninsula earth view imagery is also demonstrated due to the successful amelioration of detector differences caused by the crosstalk effect. Similarly significant improvement in detector difference is shown for the selected ocean and desert targets over the entire mission history. In particular, band 30 detector 8, which has been flagged as “out of family” is restored by the removal of the crosstalk contamination. With the correction achieved, the science applications based on band 30 can be significantly improved. The linear formulation, the characterization methodology, and the crosstalk effect correction coefficients derived using lunar

  11. Pituitary apoplexy complicated with subarachnoid hemorrhage caused by incidentaloma following a head injury:case report

    Institute of Scientific and Technical Information of China (English)

    BAO Yi-jun; LI Xin-guo; JING Zhi-tao; OU Shao-wu; WU An-hua; WANG Yun-jie

    2007-01-01

    @@ Pituitary apoplexy is a rare clinical syndrome caused by acute enlargement of pituitary adenomas,which may be secreting or nonfunctioning,and symptomatic or asymptomatic,resulted from hemorrhage or infarction.1

  12. Increased angiotensin II AT(1) receptor expression in paraventricular nucleus and hypothalamic-pituitary-adrenal axis stimulation in AT(2) receptor gene disrupted mice.

    Science.gov (United States)

    Armando, Inés; Terrón, José A; Falcón-Neri, Alicia; Takeshi, Ito; Häuser, Walter; Inagami, Tadashi; Saavedra, Juan M

    2002-09-01

    Angiotensin II AT(2) receptor gene-disrupted mice have increased blood pressure and response to angiotensin II, behavioral alterations, greater response to stress, and increased adrenal AT(1) receptors. We studied hypothalamic AT(1) receptor binding and mRNA by receptor autoradiography and in situ hybridization, adrenal catecholamines by HPLC, adrenal tyrosine hydroxylase mRNA by in situ hybridization and pituitary and adrenal hormones by RIA in AT(2) receptor-gene disrupted mice and wild-type controls. To confirm the role of adrenal AT(1) receptors, we treated wild-type C57 BL/6J mice with the AT(1) antagonist candesartan for 2 weeks, and measured adrenal hormones, catecholamines and tyrosine hydroxylase mRNA. In the absence of AT(2) receptor transcription, we found increased AT(1) receptor binding in brain areas involved in the regulation of the hypothalamic-pituitary-adrenal axis, the hypothalamic paraventricular nucleus and the median eminence, and increased adrenal catecholamine synthesis as shown by higher adrenomedullary tyrosine hydroxylase mRNA and higher adrenal dopamine, norepinephrine and epinephrine levels when compared to wild-type mice. In addition, in AT(2) receptor gene-disrupted mice there were higher plasma adrenocorticotropin (ACTH) and corticosterone levels and lower adrenal aldosterone content when compared to wild-type controls. Conversely, AT(1) receptor inhibition in CB57 BL/6J mice reduced adrenal tyrosine hydroxylase mRNA and catecholamine content and increased adrenal aldosterone content. These results can help to explain the enhanced response of AT(2) receptor gene-disrupted mice to exogenous angiotensin II, support the hypothesis of cross-talk between AT(1) and AT(2) receptors, indicate that the activity of the hypothalamic-pituitary-adrenal axis parallels the AT(1) receptor expression, and suggest that expression of AT(1) receptors can be dependent on AT(2) receptor expression. Our results provide an explanation for the increased

  13. Pituitary and ovarian function in women with congenitally absent uterus.

    Science.gov (United States)

    Ylikorkala, O; Viinikka, L

    1979-01-01

    Pituitary-ovarian function was studied in 2 women with congenital absence of the uterus and the vagina. Daily serum levels of luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, estradiol-17beta, and progesterone were measured by radioimmunoassay for 1 month. Gonadotropins and ovarian steroids showed normal cyclic variations in both patients. Prolactin was persistently elevated in one of them, who also demonstrated 2 abnormally high testosterone values among 6 determinations. The pituitary gland was stimulated by intravenous leasing hormone (LRH-TRY). Gonadotropin and prolactin responses to LRH-TRH were normal. The lifelong absence of the uterus does not alter the function of the pituitary-ovarian axis. The relation of hyperprolactinemia to this syndrome must be ascertained in a greater number of patients. PMID:104214

  14. Growth hormone secreting pituitary adenoma with admixed gangliocytoma and ganglioglioma.

    Science.gov (United States)

    Jukes, Alistair; Allan, Rodney; Rawson, Robert; Buckland, Michael E

    2016-09-01

    Pituitary adenomas are the most common tumours found in the sellar region and, when both functioning and non-functioning adenomas are combined, account for 7-15% of primary brain tumours in adults. Rarely, admixed or discrete groups of cells comprising two or more tumour subtypes are seen; the so-called 'collision tumour'. We present a case of a 54-year-old-woman with a growth hormone-secreting pituitary adenoma admixed with both ganglioglioma and gangliocytoma. The possible mechanisms by which this may occur include a pre-existing gangliocytoma promoting the development of pituitary adenoma by hypersecretion of releasing hormones or aberrant migration of hypothalamic neurons in early embryogenesis. PMID:27068013

  15. Surgical treatment of pituitary adenomas via the trans-sphenoidal route in Uzbekistan

    Directory of Open Access Journals (Sweden)

    Zamira Khalimova

    2013-12-01

    Full Text Available Pituitary adenomas, noncancerous tumors that occur in the pituitary gland, represent from 7% to 24% of all primary intracranial neoplasms. Worldwide the trans-sphenoidal approach is the preferred and more widely spread one. The work was initiated to study early and late complications in patients undergoing surgical treatment for pituitary adenomas via the trans-sphenoidal route at the Neuroendocrinology Department with pituitary neurosurgery, Center for the Scientific and Clinical Study of Endocrinology, Uzbekistan Public Health Ministry.

  16. Hedgehog signaling activation induces stem cell proliferation and hormone release in the adult pituitary gland

    OpenAIRE

    Joanna Pyczek; Rolf Buslei; David Schult; Annett Hölsken; Michael Buchfelder; Ina Heß; Heidi Hahn; Anja Uhmann

    2016-01-01

    Hedgehog (HH) signaling is known to be essential during the embryonal development of the pituitary gland but the knowledge about its role in the adult pituitary and in associated tumors is sparse. In this report we investigated the effect of excess Hh signaling activation in murine pituitary explants and analyzed the HH signaling status of human adenopituitary lobes and a large cohort of pituitary adenomas. Our data show that excess Hh signaling led to increased proliferation of Sox2+ and Sox...

  17. Pituitary hyperplasia: a complication of the pseudomalabsorption of thyroxine

    Directory of Open Access Journals (Sweden)

    Doyle MA

    2013-04-01

    Full Text Available Mary-Anne Doyle, Heather A Lochnan Division of Endocrinology, University of Ottawa, Ottawa, ON, Canada Objective: “The pseudomalabsorption of thyroxine” has been used to describe patients with hypothyroidism who fail to comply with their treatment. We describe a unique case of a 32-year-old with hypothyroidism who developed pituitary hyperplasia and hyperprolactinemia secondary to the pseudomalabsorption of thyroxine. Investigations and treatment: After baseline thyroid-function tests were performed, the patient was administered levothyroxine 0.5 mg under the supervision of a registered nurse. Thyroid function testing was repeated at 30, 60, 120, and 180 minutes. Arrangements were made for further daily supervised loading of levothyroxine 0.1 mg. Results: With the administration of 0.5 mg levothyroxine, free thyroxine levels increased by 120 minutes, and with daily supervised dosing of 0.1 mg there was normalization of the thyroid hormone levels and a reduction of thyroid-stimulating hormone levels. Maintenance of thyroid-stimulating hormone < 15 mU/L for 2 weeks led to a reduction in prolactin levels and regression in the size of the pituitary on magnetic resonance imaging. Conclusion: If left untreated, these patients face significant morbidity and are at risk of developing pituitary hyperplasia, complications from an increase in pituitary size, hyperprolactinemia, and potentially myxedema coma. Recognizing pituitary hyperplasia and hyperprolactinemia as a complication from the pseudomalabsorption of levothyroxine may prevent the potential of a misdiagnosis of a prolactinoma leading to unnecessary investigations and inappropriate treatment. Patient awareness of this serious complication and the rapid, demonstrable resolution with adequate thyroid hormone replacement may provide motivation to comply with supervised dosing of levothyroxine. It has also been suggested that supervised treatment enables the individual to maintain their patient

  18. Purification and cultivation of human pituitary growth hormone secreting cells

    Science.gov (United States)

    Hymer, W. C.

    1979-01-01

    Efforts were directed towards maintenance of actively secreting human pituitary growth hormone cells (somatotrophs) in vitro. The production of human growth hormone (hGH) by this means would be of benefit for the treatment of certain human hypopituitary diseases such as dwarfism. One of the primary approaches was the testing of agents which may logically be expected to increase hGH release. The progress towards this goal is summarized. Results from preliminary experiments dealing with electrophoresis of pituitary cell for the purpose of somatotroph separation are described.

  19. Transsphenoidal approach to pituitary adenoma: surgical technique of the Peking Union Medical College Hospital

    Institute of Scientific and Technical Information of China (English)

    LI Yong-Ning; WANG Ren-zhi; LI Gui-lin

    2009-01-01

    @@ Although presented over one hundred years ago, the transsphenoidal approach to pituitary adenoma is still the most suitable and safe route to pituitary adenoma, with a series of significant evolutional steps. The transsphenoidal approach to pituitary adenoma is still a non-universal approach used in different centers of different areas in our country.

  20. Activation of the NLRP3 inflammasome by cellular labile iron.

    Science.gov (United States)

    Nakamura, Kyohei; Kawakami, Toru; Yamamoto, Naoki; Tomizawa, Miyu; Fujiwara, Tohru; Ishii, Tomonori; Harigae, Hideo; Ogasawara, Kouetsu

    2016-02-01

    Cellular labile iron, which contains chelatable redox-active Fe(2+), has been implicated in iron-mediated cellular toxicity leading to multiple organ dysfunction. Iron homeostasis is controlled by monocytes/macrophages through their iron recycling and storage capacities. Furthermore, iron sequestration by monocytes/macrophages is regulated by pro-inflammatory cytokines including interleukin-1, highlighting the importance of these cells in the crosstalk between inflammation and iron homeostasis. However, a role for cellular labile iron in monocyte/macrophage-mediated inflammatory responses has not been defined. Here we describe how cellular labile iron activates the NLRP3 inflammasome in human monocytes. Stimulation of lipopolysaccharide-primed peripheral blood mononuclear cells with ferric ammonium citrate increases the level of cellular Fe(2+) levels in monocytes and induces production of interleukin-1β in a dose-dependent manner. This ferric ammonium citrate-induced interleukin-1β production is dependent on caspase-1 and is significantly inhibited by an Fe(2+)-specific chelator. Ferric ammonium citrate consistently induced interleukin-1β secretion in THP1 cells, but not in NLRP3-deficient THP1 cells, indicating a requirement for the NLRP3 inflammasome. Additionally, activation of the inflammasome is mediated by potassium efflux, reactive oxygen species-mediated mitochondrial dysfunction, and lysosomal membrane permeabilization. Thus, these results suggest that monocytes/macrophages not only sequestrate iron during inflammation, but also mediate inflammation in response to cellular labile iron, which provides novel insights into the role of iron in chronic inflammation. PMID:26577567

  1. Crosstalk between cancer cells and bone microenvironment in bone metastasis

    International Nuclear Information System (INIS)

    Bone, as well as lung and liver, is one of the most preferential metastatic target sites for cancers including breast, prostate, and lung cancers. Although the precise molecular mechanisms underlying this preference need to be elucidated, it appears that bone microenvironments possess unique biological features that enable circulating cancer cells to home, survive and proliferate, and destroy bone. In conjunction, cancers that develop bone metastases likely have the capacity to utilize these unique bone environments for colonization and bone destruction. This crosstalk between metastatic cancer cells and bone is critical to the development and progression of bone metastases. Disruption of this interaction will allow us to design mechanism-based effective and specific therapeutic interventions for bone metastases

  2. Thermal crosstalk simulation and measurement of linear terahertz detector arrays

    Science.gov (United States)

    Li, Weizhi; Huang, Zehua; Wang, Jun; Li, Mingyu; Gou, Jun; Jiang, Yadong

    2015-11-01

    Thermal simulation of differently structured linear terahertz detector arrays (TDAs) based on lithium tantalate was performed by finite element analysis (FEA). Simulation results revealed that a relatively simple TDA structure can have good thermal insulation, i.e., low thermal crosstalk effect (TCE), between adjacent pixels, which was thus selected for the real fabrication of TDA sample. Current responsivity (Ri) of the sample for a 2.52 THz source was measured to be 6.66 × 10-6 A/W and non-uniformity (NU) of Ri was 4.1%, showing good performance of the sample. TCE test result demonstrated that small TCE existed in the sample, which was in good agreement with the simulation results.

  3. Specificity, cross-talk and adaptation in Interferon signaling

    Science.gov (United States)

    Zilman, Anton

    Innate immune system is the first line of defense of higher organisms against pathogens. It coordinates the behavior of millions of cells of multiple types, achieved through numerous signaling molecules. This talk focuses on the signaling specificity of a major class of signaling molecules - Type I Interferons - which are also used therapeutically in the treatment of a number of diseases, such as Hepatitis C, multiple sclerosis and some cancers. Puzzlingly, different Interferons act through the same cell surface receptor but have different effects on the target cells. They also exhibit a strange pattern of temporal cross-talk resulting in a serious clinical problem - loss of response to Interferon therapy. We combined mathematical modeling with quantitative experiments to develop a quantitative model of specificity and adaptation in the Interferon signaling pathway. The model resolves several outstanding experimental puzzles and directly affects the clinical use of Type I Interferons in treatment of viral hepatitis and other diseases.

  4. Advances in the regulation and crosstalks of phytohormones

    Institute of Scientific and Technical Information of China (English)

    XIONG GuoSheng; LI JiaYang; WANG YongHong

    2009-01-01

    Various mutants defective in phytohormone biosynthesis and signaling pathways have been identified and characterized recently.Functional analysis of corresponding genes has greatly enriched our knowledge of phytohormone biosynthesis,transport,and signal transduction.Moreover,identification of phytohormone receptors and dissection of cross-talks among phytohormones allow us to elucidate the molecular basis of actions of phytohormones.The recent comprehensive work on the regulation of the biosynthesis,transport and signaling of phytohormones will help us to understand phytohormone actions in plant growth and development and their potential application in crop improvement.In this review,we summarize the latest work about phytohormones actions and highlight some common issues in this field.

  5. Crosstalk analysis of multilayer collinear volume holographic data storage

    Science.gov (United States)

    Liu, Jinqiu; Cao, Liangcai; Li, Chengmingyue; Li, Jianhua; He, Qingsheng; Jin, Guofan

    2013-09-01

    An optical model to describe the reconstructed image of the collinear holographic data storage system is presented. The 2-D shape of the recording spot in the medium is simulated. The system structure parameters that influence the signal-to-noise ratio (SNR) of the reconstructed image are investigated in order to choose proper optical components to improve data storage density of the system. The role of the random binary phase mask (RBPM) utilized in the multilayer collinear holographic system is investigated. It is proved that the inter-layer crosstalk can be effectively suppressed by using different RBPMs. Different layers of data pages can be recorded with the SNR increased by a factor of six at least and the shift selectivity along z-axis can also be improved significantly.

  6. Cross-talk effect in electrostatic based capillary array nozzles

    International Nuclear Information System (INIS)

    Electrohydrodynamic printing is a promising technique for printed electronics application. Most researchers working in this field are using a single nozzle configuration. However, for large area printing a multi-nozzle setup will be required for time and cost effective process. In this paper the influence of electric field and flow-rate on jetting angle on multi-nozzle array has been investigated experimentally. A three nozzle setup has been used in a linear array by using glass capillary as a nozzle with independent voltage applied on each nozzle and independent ink supply. The experiments are performed by changing the nozzle to nozzle gap and the effect on the jetting angle has been investigated. It has been observed that by increasing the applied voltage the jetting angle also increases at fixed flow-rate. In case of increasing the flow-rate, the jetting angle first increases with increase in flow-rate, but as the flow-rate increases at certain level the jetting angle decreases; moreover, at a high flow-rate the cone-jet length starts increasing. Numerical simulation has been performed to have a better understanding of the electric-field with respect to jetting angles. The influence of one nozzle on another nozzle is also investigated by operating the nozzle independently by using different operating cases. The cross-talk effect is also minimized by reducing the nozzle diameter. At 250 μm nozzle diameter the cross-talk effect was negligible for 5 mm nozzle-to-nozzle gap. This study will help in better understanding of the interaction between different nozzles in multi-nozzle cases and better design of the multi-nozzle system by minimizing the effects of adjacent nozzles for multi-nozzle electrohydrodynamic printing system

  7. Functional metagenomics to decipher food-microbe-host crosstalk.

    Science.gov (United States)

    Larraufie, Pierre; de Wouters, Tomas; Potocki-Veronese, Gabrielle; Blottière, Hervé M; Doré, Joël

    2015-02-01

    The recent developments of metagenomics permit an extremely high-resolution molecular scan of the intestinal microbiota giving new insights and opening perspectives for clinical applications. Beyond the unprecedented vision of the intestinal microbiota given by large-scale quantitative metagenomics studies, such as the EU MetaHIT project, functional metagenomics tools allow the exploration of fine interactions between food constituents, microbiota and host, leading to the identification of signals and intimate mechanisms of crosstalk, especially between bacteria and human cells. Cloning of large genome fragments, either from complex intestinal communities or from selected bacteria, allows the screening of these biological resources for bioactivity towards complex plant polymers or functional food such as prebiotics. This permitted identification of novel carbohydrate-active enzyme families involved in dietary fibre and host glycan breakdown, and highlighted unsuspected bacterial players at the top of the intestinal microbial food chain. Similarly, exposure of fractions from genomic and metagenomic clones onto human cells engineered with reporter systems to track modulation of immune response, cell proliferation or cell metabolism has allowed the identification of bioactive clones modulating key cell signalling pathways or the induction of specific genes. This opens the possibility to decipher mechanisms by which commensal bacteria or candidate probiotics can modulate the activity of cells in the intestinal epithelium or even in distal organs such as the liver, adipose tissue or the brain. Hence, in spite of our inability to culture many of the dominant microbes of the human intestine, functional metagenomics open a new window for the exploration of food-microbe-host crosstalk. PMID:25417646

  8. Characterizing and reducing crosstalk in printed anaglyph stereoscopic 3D images

    Science.gov (United States)

    Woods, Andrew J.; Harris, Chris R.; Leggo, Dean B.; Rourke, Tegan M.

    2013-04-01

    The anaglyph three-dimensional (3D) method is a widely used technique for presenting stereoscopic 3D images. Its primary advantages are that it will work on any full-color display and only requires that the user view the anaglyph image using a pair of anaglyph 3D glasses with usually one lens tinted red and the other lens tinted cyan. A common image quality problem of anaglyph 3D images is high levels of crosstalk-the incomplete isolation of the left and right image channels such that each eye sees a "ghost" of the opposite perspective view. In printed anaglyph images, the crosstalk levels are often very high-much higher than when anaglyph images are presented on emissive displays. The sources of crosstalk in printed anaglyph images are described and a simulation model is developed that allows the amount of printed anaglyph crosstalk to be estimated based on the spectral characteristics of the light source, paper, ink set, and anaglyph glasses. The model is validated using a visual crosstalk ranking test, which indicates good agreement. The model is then used to consider scenarios for the reduction of crosstalk in printed anaglyph systems and finds a number of options that are likely to reduce crosstalk considerably.

  9. Assessment of on-orbit crosstalk impact for SNPP VIIRS VisNIR bands

    Science.gov (United States)

    Lee, Shihyan; Oudrari, Hassan; McIntire, Jeff; Xiong, Xiaoxiong

    2014-09-01

    Electronic and optical crosstalk is one of the major challenges facing space-based Earth observing sensors, the effects of which could pose serious risks to the successful retrieval of geophysical information. There was an extensive effort during the SNPP VIIRS design and testing phase to characterize the on-orbit VisNIR crosstalk and its impact on environmental products. This paper describes an approach to assess the level of optical and electronic crosstalk on the measured radiance, and thereafter the retrieved geophysical products. During SNPP VIIRS pre-launch testing, a set of electronic and optical cross-talk influence coefficients was derived from measurements, which represent the amount of signal contamination received by each detector when other detectors on the same focal plane were illuminated. These coefficients were used to assess the potential crosstalk and its uncertainty on typical SNPP VIIRS land, atmosphere and ocean scenes. The simulation results show SNPP VIIRS crosstalk contamination is very small, less than 0.3 % for the stressing scenes, except for bands M7 and I2 over the dark ocean regions. These results are encouraging and constitute further evidence that SNPP VIIRS produces high quality imagery. The simulation approach presented in this paper could also be used for early crosstalk impact assessments for future VIIRS instruments.

  10. Characterization and modeling of crosstalk and afterpulsing in Hamamatsu silicon photomultipliers

    Science.gov (United States)

    Rosado, J.; Hidalgo, S.

    2015-10-01

    The crosstalk and afterpulsing in Hamamatsu silicon photomultipliers, called Multi-Pixel Photon Counters (MPPCs), have been studied in depth. Several components of the correlated noise have been identified according to their different possible causes and their effects on the signal. In particular, we have distinguished between prompt and delayed crosstalk as well as between trap-assisted and hole-induced afterpulsing. The prompt crosstalk has been characterized through the pulse amplitude spectrum measured at dark conditions. The newest MPPC series, which incorporate isolating trenches between pixels, exhibit a very low prompt crosstalk, but a small component remains likely due to secondary photons reflected on the top surface of the device and photon-generated minority carriers diffusing in the silicon substrate.We present a meticulous procedure to characterize the afterpulsing and delayed crosstalk through the amplitude and delay time distributions of secondary pulses. Our results indicate that both noise components are due to minority carriers diffusing in the substrate and that this effect is drastically reduced in the new MPPC series as a consequence of an increase of one order of magnitude in the doping density of the substrate.Finally, we have developed a Monte Carlo simulation to study the different components of the afterpulsing and crosstalk. The simulation results support our interpretation of the experimental data. They also demonstrate that trenches longer than those employed in the Hamamatsu MPPCs would reduce the crosstalk to a much greater extent.

  11. Numerical simulation of crosstalk in reduced pitch HgCdTe photon-trapping structure pixel arrays.

    Science.gov (United States)

    Schuster, Jonathan; Bellotti, Enrico

    2013-06-17

    We have investigated crosstalk in HgCdTe photovoltaic pixel arrays employing a photon trapping (PT) structure realized with a periodic array of pillars intended to provide broadband operation. We have found that, compared to non-PT pixel arrays with similar geometry, the array employing the PT structure has a slightly higher optical crosstalk. However, when the total crosstalk is evaluated, the presence of the PT region drastically reduces the total crosstalk; making the use of the PT structure not only useful to obtain broadband operation, but also desirable for reducing crosstalk in small pitch detector arrays. PMID:23787659

  12. Cellular Auxin Homeostasis:Gatekeeping Is Housekeeping

    Institute of Scientific and Technical Information of China (English)

    Michel Ruiz Rosquete; Elke Barbez; Jürgen Kleine-Vehn

    2012-01-01

    The phytohormone auxin is essential for plant development and contributes to nearly every aspect of the plant life cycle.The spatio-temporal distribution of auxin depends on a complex interplay between auxin metabolism and cell-to-cell auxin transport.Auxin metabolism and transport are both crucial for plant development;however,it largely remains to be seen how these processes are integrated to ensure defined cellular auxin levels or even gradients within tissues or organs.In this review,we provide a glance at very diverse topics of auxin biology,such as biosynthesis,conjugation,oxidation,and transport of auxin.This broad,but certainly superficial,overview highlights the mutual importance of auxin metabolism and transport.Moreover,it allows pinpointing how auxin metabolism and transport get integrated to jointly regulate cellular auxin homeostasis.Even though these processes have been so far only separately studied,we assume that the phytohormonal crosstalk integrates and coordinates auxin metabolism and transport.Besides the integrative power of the global hormone signaling,we additionally introduce the hypothetical concept considering auxin transport components as gatekeepers for auxin responses.

  13. In Situ Hybridization Method Reveals (Pro)renin Receptor Expressing Cells in the Pituitary Gland of Rats: Correlation with Anterior Pituitary Hormones

    International Nuclear Information System (INIS)

    Expression of (pro)renin receptor ((P)RR), a specific receptor for renin and prorenin, was studied in rat pituitary gland. In situ hybridization showed that cells expressing (P)RR mRNA were widely distributed in the anterior lobe and intermediate lobe of the pituitary gland. Double-staining using in situ hybridization for (P)RR mRNA and immunohistochemistry for the pituitary hormones showed that (P)RR mRNA was expressed in most of the GH cells and ACTH cells in the anterior lobe. (P)RR mRNA was also expressed in a few prolactin cells and TSH cells, but not in LH cells. The present study has shown for the first time the distribution of (P)RR mRNA expressing cells in the rat pituitary gland. These findings suggest that (P)RR plays physiological roles in the pituitary gland, such as the modulation of the pituitary hormone secretion

  14. Effect of treatment modality on the hypothalamic-pituitary function of patients treated with radiation therapy for pituitary adenomas: Hypothalamic dose and endocrine outcomes.

    OpenAIRE

    Andrew eElson; Joseph eBovi; Kawaljeet eKaur; Diana eMaas; Grant eSinson; Chris eSchultz

    2014-01-01

    Background: Both fractionated external beam radiotherapy and single fraction radiosurgery for pituitary adenomas are associated with the risk of hypothalamic-pituitary (HP) axis dysfunction.Objective: To analyze the effect of treatment modality (Linac, TomoTherapy, or Gamma Knife) on hypothalamic dose and correlate these with HP-Axis deficits after radiotherapy.Methods:Radiation plans of patients treated postoperatively for pituitary adenomas using Linac-based 3D Conformal Radiotherapy (CRT) ...

  15. Effect of Treatment Modality on the Hypothalamic–Pituitary Function of Patients Treated with Radiation Therapy for Pituitary Adenomas: Hypothalamic Dose and Endocrine Outcomes

    OpenAIRE

    Elson, Andrew; Bovi, Joseph; Kaur, Kawaljeet; Maas, Diana; Sinson, Grant; Schultz, Chris

    2014-01-01

    Background: Both fractionated external beam radiotherapy and single fraction radiosurgery for pituitary adenomas are associated with the risk of hypothalamic–pituitary (HP) axis dysfunction. Objective: To analyze the effect of treatment modality (Linac, TomoTherapy, or gamma knife) on hypothalamic dose and correlate these with HP-axis deficits after radiotherapy. Methods: Radiation plans of patients treated post-operatively for pituitary adenomas using Linac-based 3D-conformal radiother...

  16. Mid-wave infrared metasurface microlensed focal plane array for optical crosstalk suppression.

    Science.gov (United States)

    Akın, Onur; Demir, Hilmi Volkan

    2015-10-19

    Spatial crosstalk is one of the fundamental drawbacks of diminishing pixel size in mid-wave infrared focal plane arrays (IR-FPAs). We proposed an IR-FPA using the concept of optical phase discontinuities for substantial optical crosstalk suppression. This IR-FPA consists of asymmetrically tailored V-shaped optical antennas. Full-wave simulations confirmed major improvements in narrowing the intensity distribution of incident light beam by over 30-folds and concentrating these distributions in the central pixel of IR-FPA by achieving optical crosstalks of <1%. PMID:26480363

  17. OPtimal backlight scanning for 3D crosstalk reduction in LCD TV

    DEFF Research Database (Denmark)

    Burini, Nino; Shu, Xiao; Jiao, Liangbao; Forchhammer, Søren; Wu, Xiaolin

    2013-01-01

    This work presents a method to determine the optimal backlight scanning signals to minimize crosstalk for time-sequential stereoscopic 3D on LCD TV with active shutter glasses. The solution is obtained through optimization of the variables defined by a model of backlight scanning that considers...... important aspects like liquid crystal transitions and light diffusion, subject to constraints that ensure the rendition of a uniform backlight. Compared with basic backlight scanning, the proposed method can increase luminance at a given crosstalk level or reduce crosstalk at a given luminance level....

  18. A Joint-Coding Scheme With Crosstalk Avoidance in Network On Chip

    Directory of Open Access Journals (Sweden)

    Fen Ge

    2013-01-01

    Full Text Available The reliable transfer in Network on Chip can be guaranteed by crosstalk avoidance and error detection code. In this paper,we propose a joint coding scheme combined with crosstalk avoidance coding with error control coding. The Fibonacci numeral system is applied to satisfy the requirement of crosstalk avoidance coding, and the error detection is achieved by adding parity bits. We also implement the codec in register transfer level. Furthermore, the schemes of codec applying to fault-tolerant router are analyzed. The experimental result shows that "once encode, multiple decode" scheme outperforms other schemes in trade-o_ of delay, area and power.

  19. Crosstalk in x-ray framing cameras: Effect on voltage, gain, and timing (invited).

    Science.gov (United States)

    Benedetti, L R; Bell, P M; Bradley, D K; Brown, C G; Glenn, S M; Heeter, R; Holder, J P; Izumi, N; Khan, S F; Lacaille, G; Simanovskaia, N; Smalyuk, V A; Thomas, R

    2012-10-01

    We present evidence that electromagnetic crosstalk between independent strips in gated x-ray framing cameras can affect relative gains by up to an order of magnitude and gate arrival times up to tens of picoseconds when strip separation times are less then ∼1 ns. Crosstalk is observed by multiple methods, and it is confirmed by direct measurements of voltage on the active surface of the detector and also by indirect voltage monitors in routine operation. The voltage measurements confirm that crosstalk is produced not only in the active regions of the microchannel plate, but also along the entire input path of the voltage pulses. PMID:23126956

  20. Fourier analysis of RGB fringe-projection profilometry and robust phase-demodulation methods against crosstalk distortion

    CERN Document Server

    Padilla, Moises; Garnica, Guillermo

    2016-01-01

    In this paper we apply the frequency transfer function (FTF) formalism to analyze the red, green and blue (RGB) phase-shifting fringe-projection profilometry technique. The phase-shifted fringe patterns in RGB fringe projection are typically corrupted by crosstalk because the sensitivity curves of most projection-recording systems overlap. Crosstalk distortion needs to be compensated in order to obtain high quality measurements. We study phase-demodulation methods for null/mild, moderate, and severe levels of RGB crosstalk. For null/mild crosstalk, we can estimate the searched phase-map using Bruning's 3-step phase-shifting algorithm (PSA). For moderate crosstalk, the RGB recorded data is usually preprocessed before feeding it into Bruning's PSA; alternatively, in this paper we propose a computationally more efficient approach, which combines crosstalk compensation and phase-demodulation into a single process. For severe RGB crosstalk, we expect non-sinusoidal fringes' profiles (distorting harmonics) and sign...

  1. Hypothalamic-Pituitary Autoimmunity and Traumatic Brain Injury

    Directory of Open Access Journals (Sweden)

    Federica Guaraldi

    2015-05-01

    Full Text Available Background: Traumatic brain injury (TBI is a leading cause of secondary hypopituitarism in children and adults, and is responsible for impaired quality of life, disabilities and compromised development. Alterations of pituitary function can occur at any time after the traumatic event, presenting in various ways and evolving during time, so they require appropriate screening for early detection and treatment. Although the exact pathophysiology is unknown, several mechanisms have been hypothesized, including hypothalamic-pituitary autoimmunity (HP-A. The aim of this study was to systematically review literature on the association between HP-A and TBI-induced hypopituitarism. Major pitfalls related to the HP-A investigation were also discussed. Methods: The PubMed database was searched with a string developed for this purpose, without temporal or language limits, for original articles assessing the association of HP-A and TBI-induced hypopituitarism. Results: Three articles from the same group met the inclusion criteria. Anti-pituitary and anti-hypothalamic antibodies were detected using indirect immunofluorescence in a significant number of patients with acute and chronic TBI. Elevated antibody titer was associated with an increased risk of persistent hypopituitarism, especially somatotroph and gonadotroph deficiency, while no correlations were found with clinical parameters. Conclusion: HPA seems to contribute to TBI-induced pituitary damage, although major methodological issues need to be overcome and larger studies are warranted to confirm these preliminary data.

  2. Treatment and Prognosis of Pituitary Adenomas in Children

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to explore the treatments and prognosis of pituitary adenomas in children, the experience in the treatment of 15 children with pituitary adenomas was summed up. The clinical data of 15 children with pituitary adenomas in Tongji Hospital were retrospectively analyzed from Jan.1997 to Aug. 2004, including 9 males and 6 females with the age ranging from 9-15 years old (mean 12.8). The disease duration was 3 months to 5 years (mean 2 years). Fourteen cases were subjected to the microsurgical operation through oral tanssphenoidal approach and one case to medical treatment. All cases were followed up from 1 to 5 years by imaging studies and endocrine investigation. The results showed that 13 cases obtained total removal of the tumor and one subtotal removal of tumor. No severe complications and operation death occurred. It was concluded that the tanssphenoidal approach was the optimal treatment for children with pituitary adenomas. Regular and long-term follow-up is of great importance.

  3. Chronic stress and pituitary-adrenal function in female pigs.

    NARCIS (Netherlands)

    Janssens, C.J.J.C.

    1994-01-01

    IntroductionThe main purpose of the studies described in this thesis was to gain more insight in the regulation of the hypothalamic-pituitary-adrenocorticaI (HPA) system and the mechanisms underlying adaptation to chronic stress in female pigs. The function of the HPA axis, which coordinates multipl

  4. alpha-Melanocyte-stimulating-hormone precursors in the pig pituitary

    DEFF Research Database (Denmark)

    Fenger, M

    1986-01-01

    The occurrence of intermediates from the processing of ACTH-(1-39) [adrenocorticotropic hormone-(1-39)] to alpha-melanocyte-stimulating hormone was investigated in normal pig pituitaries by the use of sensitive and specific radioimmunoassays for ACTH-(1-13), ACTH-(1-14), ACTH-(1-13)-NH2 and ACTH-...

  5. Gamma-knife surgery for secreting pituitary adenomas

    International Nuclear Information System (INIS)

    We report our preliminary results concerning 25 patients with secreting pituitary adenomas treated with stereotactic radiosurgery after partial transsphenoidal surgery and followed over a 6-36 month-period. Among the 15 acromegalic patients, a decrease of 65% in mean GH levels was achieved after 6 months and of 77% at 12 months after radiosurgery. Presently, only 3 patients (20%) are considered as in remission (mean GH and IGF1 level into the normal range). A decrease of 46% and 64% was observed at 6 and 12 months after radiosurgery in 4 patients with prolactinomas although no normalization of PRL levels occurred. Presently, 3/4 patients have individual PRL levels slightly above the normal range. A normalization of Urinary Free Cortisol (UFC) was noticed in 4/6 (66%) patients with Cushing's disease within 6-12 months. No pituitary deficiency was noticed in this series with the exception of 4/25 patients (16%) who received subtotal or total pituitary irradiation for post-operative remnants of secreting adenomas poorly defined on MRI. One woman, who had undergone previously a conventional irradiation and presenting with a cavernous sinus adenoma reaching the optic nerve, developed an optic neuropathy. A second woman, with a cavernous sinus remnant, presented a cranial nerve palsy (VI) after the irradiation. We can conclude that radiosurgery using the Cobalt-60 Gamma-unit is, at least, as effective as conventional radiotherapy in the control of pituitary hormone hypersecretion from postoperative adenomas remnants with less adverse effects. (author)

  6. Endoscopic transsphenoidal approach to pituitary adenomas invading the cavernous sinus

    Institute of Scientific and Technical Information of China (English)

    TAO Yu-xin; QU Qiu-yi; WANG Zhen-lin; ZHANG Qiu-hang

    2010-01-01

    Background Surgery of pituitary adenomas invading cavernous sinus has always been thought as a challenge due to the complex anatomical structures and high risk of complications. The purpose of this study was to evaluate endoscopic trarssphenoidal approach to pituitary adenomas invading cavernous sinus.Methods The clinical data of 22 patients who admitted to Xuanwu Hospital with pituitary adenomas invading cavernous sinus were analyzed retrospectively. All patients underwent endoscopic transsphenoidal surgery. To expose the surgical field sufficiently, the opening of sellar floor was exceeded the bone overlying the invaded cavernous sinus, and synthetic dura was used to repair and strengthen the sella floor for preventing the leak of cerebrospinal fluid.Results Among 22 patients, total resection was achieved in 14, subtotal resection in 5, and partial resection in 3; no patient underwent insufficient resection. Visual symptoms improved in 7 of 9 patients. In one patient diplopia disappeared.Headache was relieved to various extents in all patients. No serious complications were found. Patient's hospital stay ranged from 7 to 20 days.Conclusion These data suggest that the endoscopic transsphenoid approach is a safe, minimally invasive, and efficient surgical technique, which might be an important therapeutic strategy for the pituitary adenoms invading cavernous sinus.

  7. Isolation of pancreatic trypsin inhibitor from bovine pituitary glands.

    OpenAIRE

    Li, C. H.; Chung, D.

    1983-01-01

    A trypsin inhibitor has been isolated from bovine pituitary extracts. From its amino acid composition, NH2-terminal residue, mobility in paper electrophoresis, and behavior in high-performance liquid chromatography and from the tryptic pattern of the performic acid-oxidized material, it appears that the inhibitor is identical to the Kunitz and Northrop pancreatic trypsin inhibitor.

  8. Functional Characteristics of Multipotent Mesenchymal Stromal Cells from Pituitary Adenomas.

    Science.gov (United States)

    Megnis, Kaspars; Mandrika, Ilona; Petrovska, Ramona; Stukens, Janis; Rovite, Vita; Balcere, Inga; Jansone, Laima Sabine; Peculis, Raitis; Pirags, Valdis; Klovins, Janis

    2016-01-01

    Pituitary adenomas are one of the most common endocrine and intracranial neoplasms. Although they are theoretically monoclonal in origin, several studies have shown that they contain different multipotent cell types that are thought to play an important role in tumor initiation, maintenance, and recurrence after therapy. In the present study, we isolated and characterized cell populations from seven pituitary somatotroph, nonhormonal, and lactotroph adenomas. The obtained cells showed characteristics of multipotent mesenchymal stromal cells as observed by cell morphology, cell surface marker CD90, CD105, CD44, and vimentin expression, as well as differentiation to osteogenic and adipogenic lineages. They are capable of growth and passaging under standard laboratory cell culture conditions and do not manifest any hormonal cell characteristics. Multipotent mesenchymal stromal cells are present in pituitary adenomas regardless of their clinical manifestation and show no considerable expression of somatostatin 1-5 and dopamine 2 receptors. Most likely obtained cells are a part of tissue-supportive cells in pituitary adenoma microenvironment. PMID:27340409

  9. Effect of guanfacine on pituitary hormones in man

    OpenAIRE

    Lancranjan, Ioana

    1980-01-01

    1 Animal studies have shown that adrenaline and noradrenaline are involved in the control of pituitary function. As very few data on this topic were available in man, some studies were carried out mainly in young normal volunteers using guanfacine, a new drug with central α-adrenoceptor properties.

  10. Hyperprolactinemia Secondary to Allergic Fungal Sinusitis Compressing the Pituitary Gland.

    Science.gov (United States)

    Chapurin, Nikita; Wang, Cynthia; Steinberg, David M; Jang, David W

    2016-01-01

    Objective. We aim to describe the first case in the literature of allergic fungal sinusitis (AFS) presenting with hyperprolactinemia due to compression of the pituitary gland. Case Presentation. A 37-year-old female presented with bilateral galactorrhea and occipital headaches of several weeks. Workup revealed elevated prolactin of 94.4, negative pregnancy test, and normal thyroid function. MRI and CT demonstrated a 5.0 × 2.7 × 2.5 cm heterogeneous expansile mass in the right sphenoid sinus with no pituitary adenoma as originally suspected. Patient was placed on cabergoline for symptomatic control until definitive treatment. Results. The patient underwent right endoscopic sphenoidotomy, which revealed nasal polyps and fungal debris in the sphenoid sinus, consistent with AFS. There was bony erosion of the sella and clivus. Pathology and microbiology were consistent with allergic fungal sinusitis caused by Curvularia species. Prolactin levels normalized four weeks after surgery with resolution of symptoms. Conclusion. Functional endoscopic sinus surgery alone was able to reverse the patient's pituitary dysfunction. To our knowledge, this is the first case of AFS presenting as hyperprolactinemia due to pituitary compression. PMID:26998375

  11. Early effects of cranial irradiation on hypothalamic-pituitary function

    Energy Technology Data Exchange (ETDEWEB)

    Lam, K.S.; Tse, V.K.; Wang, C.; Yeung, R.T.; Ma, J.T.; Ho, J.H.

    1987-03-01

    Hypothalamic-pituitary function was studied in 31 patients before and after cranial irradiation for nasopharyngeal carcinoma. The estimated radiotherapy (RT) doses to the hypothalamus and pituitary were 3979 +/- 78 (+/- SD) and 6167 +/- 122 centiGrays, respectively. All patients had normal pituitary function before RT. One year after RT, there was a significant decrease in the integrated serum GH response to insulin-induced hypoglycemia. In the male patients, basal serum FSH significantly increased, while basal serum LH and testosterone did not change. Moreover, in response to LHRH, the integrated FSH response was increased while that of LH was decreased. Such discordant changes in FSH and LH may be explained by a defect in LHRH pulsatile release involving predominantly a decrease in pulse frequency. The peak serum TSH response to TRH became delayed in 28 patients, suggesting a defect in TRH release. Twenty-one patients were reassessed 2 yr after RT. Their mean basal serum T4 and plasma cortisol levels had significantly decreased. Hyperprolactinemia associated with oligomenorrhoea was found in 3 women. Further impairment in the secretion of GH, FSH, LH, TSH, and ACTH had occurred, and 4 patients had hypopituitarism. Thus, progressive impairment in hypothalamic-pituitary function occurs after cranial irradiation and can be demonstrated as early as 1 yr after RT.

  12. Hyperprolactinemia Secondary to Allergic Fungal Sinusitis Compressing the Pituitary Gland

    Directory of Open Access Journals (Sweden)

    Nikita Chapurin

    2016-01-01

    Full Text Available Objective. We aim to describe the first case in the literature of allergic fungal sinusitis (AFS presenting with hyperprolactinemia due to compression of the pituitary gland. Case Presentation. A 37-year-old female presented with bilateral galactorrhea and occipital headaches of several weeks. Workup revealed elevated prolactin of 94.4, negative pregnancy test, and normal thyroid function. MRI and CT demonstrated a 5.0 × 2.7 × 2.5 cm heterogeneous expansile mass in the right sphenoid sinus with no pituitary adenoma as originally suspected. Patient was placed on cabergoline for symptomatic control until definitive treatment. Results. The patient underwent right endoscopic sphenoidotomy, which revealed nasal polyps and fungal debris in the sphenoid sinus, consistent with AFS. There was bony erosion of the sella and clivus. Pathology and microbiology were consistent with allergic fungal sinusitis caused by Curvularia species. Prolactin levels normalized four weeks after surgery with resolution of symptoms. Conclusion. Functional endoscopic sinus surgery alone was able to reverse the patient’s pituitary dysfunction. To our knowledge, this is the first case of AFS presenting as hyperprolactinemia due to pituitary compression.

  13. Early effects of cranial irradiation on hypothalamic-pituitary function

    International Nuclear Information System (INIS)

    Hypothalamic-pituitary function was studied in 31 patients before and after cranial irradiation for nasopharyngeal carcinoma. The estimated radiotherapy (RT) doses to the hypothalamus and pituitary were 3979 +/- 78 (+/- SD) and 6167 +/- 122 centiGrays, respectively. All patients had normal pituitary function before RT. One year after RT, there was a significant decrease in the integrated serum GH response to insulin-induced hypoglycemia. In the male patients, basal serum FSH significantly increased, while basal serum LH and testosterone did not change. Moreover, in response to LHRH, the integrated FSH response was increased while that of LH was decreased. Such discordant changes in FSH and LH may be explained by a defect in LHRH pulsatile release involving predominantly a decrease in pulse frequency. The peak serum TSH response to TRH became delayed in 28 patients, suggesting a defect in TRH release. Twenty-one patients were reassessed 2 yr after RT. Their mean basal serum T4 and plasma cortisol levels had significantly decreased. Hyperprolactinemia associated with oligomenorrhoea was found in 3 women. Further impairment in the secretion of GH, FSH, LH, TSH, and ACTH had occurred, and 4 patients had hypopituitarism. Thus, progressive impairment in hypothalamic-pituitary function occurs after cranial irradiation and can be demonstrated as early as 1 yr after RT

  14. Guanine nucleotide regulation of dopamine receptor agonist affinity states in rat estradiol-induced pituitary tumors

    Energy Technology Data Exchange (ETDEWEB)

    Di Paolo, T.; Falardeau, P.

    1987-08-31

    The authors have investigated dopamine (DA) receptor agonist high- and low-affinity states in female rate estradiol-induced prolactin (PRL)-secreting pituitary tumors and intact pituitary tissue. Estradiol treatment increased the anterior pituitary weight 9-fold and plasma prolactin levels 74-fold and these measures are correlated (R = 0.745, n = 73, p < 0.001). Competition for (/sup 3/H)-spiperone binding to the DA receptor by apomorphine was compared in normal and adenomatous pituitary tissue. The inhibition constants (Ki) and the proportions of the two apomorphine sites are unchanged in tumors compared to intact pituitary tissue. Guanosine 5'-(..beta..-..gamma..-imino)triphosphate (Gpp(NH)p) causes complete conversion of the high into low affinity dopaminergic agonist site in normal pituitary and in tumors. These results suggest that rats with primary estradiol-induced pituitary tumors have normal and functional DA receptors. 9 references, 2 tables.

  15. Guanine nucleotide regulation of dopamine receptor agonist affinity states in rat estradiol-induced pituitary tumors

    International Nuclear Information System (INIS)

    The authors have investigated dopamine (DA) receptor agonist high- and low-affinity states in female rate estradiol-induced prolactin (PRL)-secreting pituitary tumors and intact pituitary tissue. Estradiol treatment increased the anterior pituitary weight 9-fold and plasma prolactin levels 74-fold and these measures are correlated (R = 0.745, n = 73, p 3H]-spiperone binding to the DA receptor by apomorphine was compared in normal and adenomatous pituitary tissue. The inhibition constants (Ki) and the proportions of the two apomorphine sites are unchanged in tumors compared to intact pituitary tissue. Guanosine 5'-[β-γ-imino]triphosphate (Gpp(NH)p) causes complete conversion of the high into low affinity dopaminergic agonist site in normal pituitary and in tumors. These results suggest that rats with primary estradiol-induced pituitary tumors have normal and functional DA receptors. 9 references, 2 tables

  16. GH and Pituitary Hormone Alterations After Traumatic Brain Injury.

    Science.gov (United States)

    Karaca, Züleyha; Tanrıverdi, Fatih; Ünlühızarcı, Kürşad; Kelestimur, Fahrettin

    2016-01-01

    Traumatic brain injury (TBI) is a crucially important public health problem around the world, which gives rise to increased mortality and is the leading cause of physical and psychological disability in young adults, in particular. Pituitary dysfunction due to TBI was first described 95years ago. However, until recently, only a few papers have been published in the literature and for this reason, TBI-induced hypopituitarism has been neglected for a long time. Recent studies have revealed that TBI is one of the leading causes of hypopituitarism. TBI which causes hypopituitarism may be characterized by a single head injury such as from a traffic accident or by chronic repetitive head trauma as seen in combative sports including boxing, kickboxing, and football. Vascular damage, hypoxic insult, direct trauma, genetic predisposition, autoimmunity, and neuroinflammatory changes may have a role in the development of hypopituitarism after TBI. Because of the exceptional structure of the hypothalamo-pituitary vasculature and the special anatomic location of anterior pituitary cells, GH is the most commonly lost hormone after TBI, and the frequency of isolated GHD is considerably high. TBI-induced pituitary dysfunction remains undiagnosed and therefore untreated in most patients because of the nonspecific and subtle clinical manifestations of hypopituitarism. Treatment of TBI-induced hypopituitarism depends on the deficient anterior pituitary hormones. GH replacement therapy has some beneficial effects on metabolic parameters and neurocognitive dysfunction. Patients with TBI without neuroendocrine changes and those with TBI-induced hypopituitarism share the same clinical manifestations, such as attention deficits, impulsion impairment, depression, sleep abnormalities, and cognitive disorders. For this reason, TBI-induced hypopituitarism may be neglected in TBI victims and it would be expected that underlying hypopituitarism would aggravate the clinical picture of TBI itself

  17. Primary hypothyroidism presenting as pituitary hyperplasia with hyperprolactinemia

    Directory of Open Access Journals (Sweden)

    Xiao-ling YAN

    2016-04-01

    Full Text Available Objective To discuss the histological characteristics, immunohistochemical phenotypes, diagnosis and differential diagnosis, treatment and prognosis of one case of primary hypothyroidism presenting as pituitary hyperplasia concurrent with hyperprolactinemia.  Methods and Results A 29-year-old female presented menoxenia for one year, galactorrhea for 3 months, and headache for one week. Head MRI demonstrated a sellar space-occcupying lesion and a pituitary adenoma was suspected. Therefore, the patient underwent an exploratory surgery via transnasal-sphenoidal approach under general anesthesia. During the surgery the lesion was located in the right side of sella turcica. It was hard, tough and gray with poor blood supply. Under optical microscopy, the acinar cells showed a diffuse hyperplasia, with focal nodular expansion. The boundary between hyperplastic and normal acinus was ill-defined. By using immunohistochemical staining, the hyperplastic cells were diffusely positive for synaptophysin (Syn and thyroid stimulating hormone (TSH, partially positive for prolactin (PRL, and negative for thyoid transcription factor-1 (TTF-1. Lymphocytes were scatteredly positive for leukocyte common antigen (LCA. Ki-67 labeling index was less than 1%. Pathological diagnosis was pituitary hyperplasia. The final clinical diagnosis was hypothyroidism. The patient took levothyroxine sodium (Euthyrox 100 μg/d continously, and was well during the 13-month follow-up.  Conclusions Preopertive diagnosis of pituitary hyperplasia is difficult.Definite diagnosis could be made by clinical history, typical histopathological characteristics and immunohistochemical phenotypes. Differential diagnosis from pituitary adenoma, especially microadenoma, should be paid attention. DOI: 10.3969/j.issn.1672-6731.2016.04.009

  18. The chicken pituitary-specific transcription factor Pit-1 is involved in the hypothalamic regulation of pituitary hormones

    NARCIS (Netherlands)

    As, van P.; Janssens, K.; Pals, K.; Groef, De B.; Onagbesan, O.M.; Bruggeman, V.; Darras, V.M.; Denef, C.; Decuypere, E.

    2006-01-01

    Pit-1 is a pituitary-specific POU-domain DNA binding factor, which binds to and trans-activates promoters of growth hormone- (GH), prolactin- (PRL) and thyroid stimulating hormone-beta- (TSHbeta) encoding genes. Thyrotropin-releasing hormone (TRH) is located in the hypothalamus and stimulates TSH, G

  19. Cross-talk between ciliary epithelium and trabecular meshwork cells in-vitro: a new insight into glaucoma.

    Directory of Open Access Journals (Sweden)

    Natalie Lerner

    Full Text Available PURPOSE: It is assumed that the non-pigmented ciliary epithelium plays a role in regulating intraocular pressure via its neuroendocrine activities. To test this hypothesis, we investigated the effect on a human trabecular meshwork (TM cell line (NTM of co-culture with a human non-pigmented ciliary epithelium cell line (ODM-2. METHODS: The cellular cross-talk between ODM-2 and NTM cells was studied in a co-culture system in which the two cell types were co-cultured for 5 to 60 min or 2, 4 and 8h and then removed from the co-culture and analyzed. Analyses of the ERK and p38 mitogen-activated protein kinase (MAPK pathways and of the activity of TM phosphatases and matrix metalloproteins (MMPs were performed. Acid and alkaline phosphatase activity was determined by the DiFMUP (6, 8-difluoro-4-methylumbelliferyl phosphate assay. MMP levels were determined by gelatin zymography. RESULTS: Exposure of NTM cells to ODM-2 cells led to the activation of the MAPK signal transduction pathways in NTM cells within 5 min of co-culture. Phosphorylation of ERK1/ERK2 and p38 peaked at 10 and 15 min and then decreased over time. Interaction between ODM-2 and NTM cells promoted the expression of MMP-9 in the NTM cells after 4h of co-culture. CONCLUSIONS: Our findings provide support for the hypothesis that crosstalk does indeed take place between ODM-2 and NTM cells. Future studies should be designed to determine the relationship between the MMP system, MAPK kinases and phosphatases. Manipulation of these signaling molecules and the related NTM signal transduction pathways may provide targets for developing improved treatments for glaucoma.

  20. Cross-talk between macrophages and smooth muscle cells impairs collagen and metalloprotease synthesis and promotes angiogenesis.

    Science.gov (United States)

    Butoi, E; Gan, A M; Tucureanu, M M; Stan, D; Macarie, R D; Constantinescu, C; Calin, M; Simionescu, M; Manduteanu, I

    2016-07-01

    Coronary atherosclerosis complicated by plaque disruption and thrombosis is a critical event in myocardial infarction and stroke, the major causes of cardiovascular death. In atherogenesis, macrophages (MAC) and smooth muscle cells (SMC) are key actors; they synthesize matrix components and numerous factors involved in the process. Here, we design experiments to investigate whether SMC-MAC communication induces changes in ECM protein composition and/or neo-angiogenesis. Cell to cell communication was achieved using trans-well chambers, where SMCs were grown in the upper chamber and differentiated MAC in the bottom chamber for 24 or 72h. We found that cross-talk between MAC and SMC during co-culture: (i) significantly decreased the expression of ECM proteins (collagen I, III, elastin) in SMC; (ii) increased the expression and activity of metalloprotease MMP-9 and expression of collagenase MMP-1, in both MAC and SMC; (iii) augmented the secretion of soluble VEGF in the conditioned media of cell co-culture and VEGF gene expression in both cell types, compared with control cells. Moreover, the conditioned media collected from MAC-SMC co-culture promoted endothelial cell tube formation in Matrigel, signifying an increased angiogenic effect. In addition, the MAC-SMC communication led to an increase in inflammatory IL-1β and TLR-2, which could be responsible for cellular signaling. In conclusion, MAC-SMC communication affects factors and molecules that could alter ECM composition and neo-angiogenesis, features that could directly dictate the progression of atheroma towards the vulnerable plaque. Targeting the MAC-SMC cross-talk may represent a novel therapeutic strategy to slow-down or retard the plaque progression. PMID:27060293

  1. How actin/myosin crosstalks guide the adhesion, locomotion and polarization of cells.

    Science.gov (United States)

    Sackmann, Erich

    2015-11-01

    Cell-tissue-tissue interaction is determined by specific short range forces between cell adhesion molecules (CAMs) and ligands of the tissue, long range repulsion forces mediated by cell surface grafted macromolecules and adhesion-induced elastic stresses in the cell envelope. This interplay of forces triggers the rapid random clustering of tightly coupled linkers. By coupling of actin gel patches to the intracellular domains of the CAMs, these clusters can grow in a secondary process resulting in the formation of functional adhesion microdomains (ADs). The ADs can act as biochemical steering centers by recruiting and activating functional proteins, such as GTPases and associated regulating proteins, through electrostatic-hydrophobic forces with cationic lipid domains that act as attractive centers. First, I summarize physical concepts of cell adhesion revealed by studies of biomimetic systems. Then I describe the role of the adhesion domains as biochemical signaling platforms and force transmission centers promoting cellular protrusions, in terms of a shell string model of cells. Protrusion forces are generated by actin gelation triggered by molecular machines (focal adhesion kinase (FAK), Src-kinases and associated adaptors) which assemble around newly formed integrin clusters. They recruit and activate the GTPases Rac-1 and actin gelation promoters to charged membrane domains via electrostatic-hydrophobic forces. The cell front is pushed forward in a cyclic and stepwise manner and the step-width is determined by the dynamics antagonistic interplay between Rac-1 and RhoA. The global cell polarization in the direction of motion is mediated by the actin-microtubule (MT) crosstalk at adhesion domains. Supramolecular actin-MT assemblies at the front help to promote actin polymerization. At the rear they regulate the dismantling of the ADs through the Ca(++)-mediated activation of the protease calpain and trigger their disruption by RhoA mediated contraction via

  2. Heterogeneous glioblastoma cell cross-talk promotes phenotype alterations and enhanced drug resistance.

    Science.gov (United States)

    Motaln, Helena; Koren, Ana; Gruden, Kristina; Ramšak, Živa; Schichor, Christian; Lah, Tamara T

    2015-12-01

    Glioblastoma multiforme is the most lethal of brain cancer, and it comprises a heterogeneous mixture of functionally distinct cancer cells that affect tumor progression. We examined the U87, U251, and U373 malignant cell lines as in vitro models to determine the impact of cellular cross-talk on their phenotypic alterations in co-cultures. These cells were also studied at the transcriptome level, to define the mechanisms of their observed mutually affected genomic stability, proliferation, invasion and resistance to temozolomide. This is the first direct demonstration of the neural and mesenchymal molecular fingerprints of U87 and U373 cells, respectively. U87-cell conditioned medium lowered the genomic stability of U373 (U251) cells, without affecting cell proliferation. In contrast, upon exposure of U87 cells to U373 (U251) conditioned medium, U87 cells showed increased genomic stability, decreased proliferation rates and increased invasion, due to a plethora of produced cytokines identified in the co-culture media. This cross talk altered the expression 264 genes in U87 cells that are associated with proliferation, inflammation, migration, and adhesion, and 221 genes in U373 cells that are associated with apoptosis, the cell cycle, cell differentiation and migration. Indirect and direct co-culturing of U87 and U373 cells showed mutually opposite effects on temozolomide resistance. In conclusion, definition of transcriptional alterations of distinct glioblastoma cells upon co-culturing provides better understanding of the mechanisms of glioblastoma heterogeneity, which will provide the basis for more informed glioma treatment in the future. PMID:26517510

  3. Influence of fibre design and curvature on crosstalk in multi-core fibre

    Science.gov (United States)

    Egorova, O. N.; Astapovich, M. S.; Melnikov, L. A.; Salganskii, M. Yu; Mishkin, S. N.; Nishchev, K. N.; Semjonov, S. L.; Dianov, E. M.

    2016-03-01

    We have studied the influence of cross-sectional structure and bends on optical cross-talk in a multicore fibre. A reduced refractive index layer produced between the cores of such fibre with a small centre-to-centre spacing between neighbouring cores (27 μm) reduces optical cross-talk by 20 dB. The cross-talk level achieved, 30 dB per kilometre of the length of the multicore fibre, is acceptable for a number of applications where relatively small lengths of fibre are needed. Moreover, a significant decrease in optical cross-talk has been ensured by reducing the winding diameter of multicore fibres with identical cores.

  4. A Novel Metamaterial Structure to Reduce Far-End Crosstalk in Printed Circuit Boards

    Directory of Open Access Journals (Sweden)

    R.Azhagumurugan

    2014-05-01

    Full Text Available Far-End crosstalk is a common problem in a printed circuit boards when two transmission lines are in close proximity. This paper proposes a newly designed method to reduce the far-end crosstalk using metamaterials as a complementary split ring resonator (CSRRs. The CSRRs are etched in the ground plane and are used to control the radiated electromagnetic fileds. Comparative analyses are taken for three cases with solid ground plane etching one CSRR and 2 CSRRs in the ground plane. Analysis shows that a significant reduction in the crosstalk is achieved when 2 CSRRs are etched in the ground plane. This design is made to reduce the crosstalk without additional components.

  5. Impaired crosstalk between pulsatile insulin and glucagon secretion in prediabetic individuals

    DEFF Research Database (Denmark)

    Rohrer, Stefan; Menge, Björn A; Grüber, Lena; Deacon, Carolyn F; Schmidt, Wolfgang E; Veldhuis, Johannes D; Holst, Jens Juul; Meier, Juris J

    2012-01-01

    Postprandial hyperglucagonemia is frequently found in patients with diabetes. Recently, a loss of the inverse relationship between pulsatile insulin and glucagon secretion has been reported in patients with type 2 diabetes. The crosstalk between pulsatile islet hormone secretion in prediabetic...

  6. Through-silicon-via crosstalk model and optimization design for three-dimensional integrated circuits

    International Nuclear Information System (INIS)

    Through-silicon-via (TSV) to TSV crosstalk noise is one of the key factors affecting the signal integrity of three-dimensional integrated circuits (3D ICs). Based on the frequency dependent equivalent electrical parameters for the TSV channel, an analytical crosstalk noise model is established to capture the TSV induced crosstalk noise. The impact of various design parameters including insulation dielectric, via pitch, via height, silicon conductivity, and terminal impedance on the crosstalk noise is analyzed with the proposed model. Two approaches are proposed to alleviate the TSV noise, namely, driver sizing and via shielding, and the SPICE results show 241 mV and 379 mV reductions in the peak noise voltage, respectively

  7. Crosstalk reduction in free space optical interconnects systems using microlenses with Gaussian transmittance

    Science.gov (United States)

    Al-Ababneh, Nedal

    2014-05-01

    A novel method to reduce the diffraction crosstalk for micro-lens based free space optical interconnects is presented. Instead of using microlenses with uniform transmittance apertures, the use of microlenses with non-uniform transmittance apertures is proposed. It is shown that the diffraction crosstalk which exists in the free space interconnects systems that use microlenses with uniform transmittance apertures can be substantially reduced by using microlenses with Gaussian transmittance. The optical field at the detectors array using both the uniform and Gaussian apertures have been derived and used to calculate the crosstalk. Numerical results have been introduced to show the improvement of the signal-to-crosstalk ratio when using the Gaussian transmittance for the microlens.

  8. Optical crosstalk in single photon avalanche diode arrays: a new complete model.

    Science.gov (United States)

    Rech, Ivan; Ingargiola, Antonino; Spinelli, Roberto; Labanca, Ivan; Marangoni, Stefano; Ghioni, Massimo; Cova, Sergio

    2008-06-01

    One of the main issues of Single Photon Avalanche Diode arrays is optical crosstalk. Since its intensity increases with reducing the distance between devices, this phenomenon limits the density of integration within arrays. In the past optical crosstalk was ascribed essentially to the light propagating from one detector to another through direct optical paths. Accordingly, reflecting trenches between devices were proposed to prevent it, but they proved to be not completely effective. In this paper we will present experimental evidence that a significant contribution to optical crosstalk comes from light reflected internally off the bottom of the chip, thus being impossible to eliminate it completely by means of trenches. We will also propose an optical model to predict the dependence of crosstalk on the distance between devices. PMID:18545552

  9. Crosstalk in the measurement of focal brain activation by near-infrared topography

    Science.gov (United States)

    Okui, N.; Okada, E.

    2005-08-01

    Crosstalk between oxy- and deoxy-haemoglobin observed in near-infrared topography is investigated. The light propagation in an adult head model is predicted by Monte Carlo simulation to obtain the change in intensity detected with source-detector pairs on the scalp caused by a focal absorption change in the brain. The topographic images of changes in oxy- and deoxy-haemoglobin are obtained from the changes in intensity detected with source-detector pairs on the scalp. The crosstalk depends on the relative position of the focal absorption change to source-detector pairs. The crosstalk is minimised when the focal absorption change is located below a measurement point that is the midpoint between a source and a detector. Appropriate selection of wavelength pair is effective to reduce the crosstalk in the topographic image.

  10. Optimal Crosstalk Detection and Localization Method for Optical Time Division Multiplexed Transmission Systems

    CERN Document Server

    Jedidi, A Ahmed

    2010-01-01

    All-Optical Network (AON) is a network where the user-network interface is optical and the data does undergo optical to electrical conversion within the network. AONs are attractive because they promise very high rates, flexible switching and broad application support. There are two technologies for AON: Wavelength Division Multiplexed (WDM) and Optical Time Division Multiplexed (OTDM). OTDM transmission systems are becoming increasingly important as one of the key technologies satisfying the growing demand for large capacity optical networks. Although OTDM has several advantages in terms of operation system, such as natural accommodation of higher bit rate payloads, it introduces many security vulnerabilities, which do not exist in traditional networks. One of the serious problems with OTDM is the fact that optical crosstalk is additive, and thus the aggregate effect of crosstalk over a whole all-optical network (AON) may be more nefarious than a single point of crosstalk. This is because crosstalk can sprea...

  11. Crosstalk Suppression in Header Recognition Unit Using Time-Space Conversion

    Institute of Scientific and Technical Information of China (English)

    Hideaki Furukawa; Tsuyoshi Konishi; Yoshinori Oshita; Wanji Yu; Kazuyoshi Itoh; Yoshiki Ichioka

    2003-01-01

    We demonstrate a suppression effect of a crosstalk among a target and similar header signals using the header recognition filter designed by a design technique of the multiple-object discriminant filter.

  12. A Pepducin Derived from the Third Intracellular Loop of FPR2 Is a Partial Agonist for Direct Activation of This Receptor in Neutrophils But a Full Agonist for Cross-Talk Triggered Reactivation of FPR2

    DEFF Research Database (Denmark)

    Gabl, Michael; Winther, Malene; Skovbakke, Sarah Line; Bylund, Johan; Forsman, Huamei; Dahlgren, Claes

    2014-01-01

    We recently described a novel receptor cross-talk mechanism in neutrophils, unique in that the signals generated by the PAF receptor (PAFR) and the ATP receptor (P2Y2R) transfer formyl peptide receptor 1 (FPR1) from a desensitized (non-signaling) state back to an actively signaling state (Forsman H...... desensitized with the FPR2-specific pepducin display increased cellular responses to stimulation with PAF or ATP. The secondary PAF/ATP induced response was sensitive to FPR2-specific inhibitors, disclosing a receptor cross-talk mechanism underlying FPR2 reactivation. The pepducin induced an activity in naïve...... cells similar to that of a conventional FPR2 agonist, but with lower potency (partial efficacy), meaning that the pepducin is a partial agonist. The PAF- or ATP-induced reactivation was, however, much more pronounced when neutrophils had been desensitized to the pepducin as compared to cells...

  13. Ultra-low crosstalk, CMOS compatible waveguide crossings for densely integrated photonic interconnection networks.

    Science.gov (United States)

    Jones, Adam M; DeRose, Christopher T; Lentine, Anthony L; Trotter, Douglas C; Starbuck, Andrew L; Norwood, Robert A

    2013-05-20

    We explore the design space for optimizing CMOS compatible waveguide crossings on a silicon photonics platform. This paper presents simulated and experimental excess loss and crosstalk suppression data for vertically integrated silicon nitride over silicon-on-insulator waveguide crossings. Experimental results show crosstalk suppression exceeding -49/-44 dB with simulation results as low as -65/-60 dB for the TE/TM mode in a waveguide crossing with a 410 nm vertical gap. PMID:23736422

  14. Crosstalk and the evolution of specificity in two-component signaling

    OpenAIRE

    Rowland, Michael A.; Deeds, Eric J.

    2014-01-01

    The global architectures of signaling networks in bacteria and eukaryotes are remarkably different: crosstalk between pathways is very common in eukaryotes but is very limited in bacteria. Bacteria use two-component signaling (TCS) to transduce information, relying on a single enzyme to act as both kinase and phosphatase for targets. We used mathematical models to show that introducing crosstalk in TCS always decreases system performance. This indicates that the large-scale differences betwee...

  15. Electrical cross-talk in two-port resonators the resonant silicon beam force sensor

    OpenAIRE

    Mullem, van, F.; Tilmans, H. A. C.; Mouthaan, A.J.; Fluitman, J.H.J.

    1992-01-01

    An important design consideration in the development of two-port resonant sensors is the electrical cross-talk between the input port and the output port. The overall transfer function (j) of the two-port sensor is equal to the vectorial sum of a transfer function representing the mechanical behavior and a transfer function representing the electrical cross-talk. The resonant silicon beam force sensor with a piezoelectric driver and a piezoelectric detector is analyzed. Two solutions to reduc...

  16. Wrist electrogoniometry: are current mathematical correction procedures effective in reducing crosstalk in functional assessment?

    Directory of Open Access Journals (Sweden)

    Fabiana A. Foltran

    2013-02-01

    Full Text Available BACKGROUND: The recording of human movement is an essential requirement for biomechanical, clinical, and occupational analysis, allowing assessment of postural variation, occupational risks, and preventive programs in physical therapy and rehabilitation. The flexible electrogoniometer (EGM, considered a reliable and accurate device, is used for dynamic recordings of different joints. Despite these advantages, the EGM is susceptible to measurement errors, known as crosstalk. There are two known types of crosstalk: crosstalk due to sensor rotation and inherent crosstalk. Correction procedures have been proposed to correct these errors; however no study has used both procedures in clinical measures for wrist movements with the aim to optimize the correction. OBJECTIVE: To evaluate the effects of mathematical correction procedures on: 1 crosstalk due to forearm rotation, 2 inherent sensor crosstalk; and 3 the combination of these two procedures. METHOD: 43 healthy subjects had their maximum range of motion of wrist flexion/extension and ulnar/radials deviation recorded by EGM. The results were analyzed descriptively, and procedures were compared by differences. RESULTS: There was no significant difference in measurements before and after the application of correction procedures (P<0.05. Furthermore, the differences between the correction procedures were less than 5° in most cases, having little impact on the measurements. CONCLUSIONS: Considering the time-consuming data analysis, the specific technical knowledge involved, and the inefficient results, the correction procedures are not recommended for wrist recordings by EGM.

  17. Modeling, Prediction, and Reduction of 3D Crosstalk in Circular Polarized Stereoscopic LCDs.

    Science.gov (United States)

    Zeng, Menglin; Robinson, Alan E; Nguyen, Truong Q

    2015-12-01

    Crosstalk, which is the incomplete separation between the left and right views in 3D displays, induces ghosting and causes difficulty of the eyes to fuse the stereo image for depth perception. Circularly polarized (CP) liquid crystal display (LCD) is one of the main-stream consumer 3D displays with the prospering of 3D movies and gamings. The polarizing system including the patterned retarder is one of the major causes of crosstalk in CP LCD. The contributions of this paper are the modeling of the polarizing system of CP LCD, and a crosstalk reduction method that efficiently cancels crosstalk and preserves image contrast. For the modeling, the practical orientation of the polarized glasses (PG) is considered. In addition, this paper calculates the rotation of the light-propagation coordinate for the Stokes vector as light propagates from LCD to PG, and this calculation is missing in the previous works when applying Mueller calculus. The proposed crosstalk reduction method is formulated as a linear programming problem, which can be easily solved. In addition, we propose excluding the highly textured areas in the input images to further preserve image contrast in crosstalk reduction. PMID:26259220

  18. Crosstalk between adiponectin and IGF-IR in breast cancer

    Directory of Open Access Journals (Sweden)

    Loredana eMauro

    2015-07-01

    Full Text Available Obesity is a chronic and multifactorial disorder that is reaching epidemic proportions. It is characterized by an enlarged mass of adipose tissue caused by a combination of size increase of preexisting adipocytes (hypertrophy and de novo adipocyte differentiation (hyperplasia. Obesity is related to many metabolic disorders like hypertension, type 2 diabetes, metabolic syndrome, cardiovascular disease, and it is associated with an increased risk of cancer development in different tissues including breast. Adipose tissue is now regarded as not just a storage reservoir for excess energy, but rather as an endocrine organ, secreting a large number of bioactive molecules called adipokines. Among these, adiponectin represents the most abundant adipose tissue-excreted protein, which exhibits insulin-sensitizing, anti-inflammatory and antiatherogenic properties. The serum concentrations of adiponectin are inversely correlated with body mass index. Recently, low levels of plasma adiponectin have been associated with an increased risk for obesity-related cancers and development of more aggressive phenotype, concomitantly with alterations in the bioavailability of Insulin-like Growth Factor-I (IGF-I and IGF-I Receptor (IGF-IR signaling pathways. In this review we discuss the cross-talk between adiponectin/AdipoR1 and IGF-I/IGF-IR in breast cancer.

  19. Crosstalk between innate and adaptive immunity inhepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Hepatitis B virus (HBV) infection is a major public health problem worldwide. HBV is not directly cytotoxic toinfected hepatocytes; the clinical outcome of infectionresults from complicated interactions between the virusand the host immune system. In acute HBV infection,initiation of a broad, vigorous immune response is responsiblefor viral clearance and self-limited inflammatoryliver disease. Effective and coordinated innate andadaptive immune responses are critical for viral clearanceand the development of long-lasting immunity. Chronichepatitis B patients fail to mount efficient innate andadaptive immune responses to the virus. In particular,HBV-specific cytotoxic T cells, which are crucial for HBVclearance, are hyporesponsiveness to HBV infection.Accumulating experimental evidence obtained fromthe development of animal and cell line models hashighlighted the importance of innate immunity in theearly control of HBV spread. The virus has evolvedimmune escape strategies, with higher HBV loads andHBV protein concentrations associated with increasingimpairment of immune function. Therefore, treatmentof HBV infection requires inhibition of HBV replicationand protein expression to restore the suppressedhost immunity. Complicated interactions exist notonly between innate and adaptive responses, but alsoamong innate immune cells and different components ofadaptive responses. Improved insight into these complexinteractions are important in designing new therapeuticstrategies for the treatment HBV infection. In thisreview, we summarize the current knowledge regardingthe cross-talk between the innate and adaptive immuneresponses and among different immunocytes in HBVinfection.

  20. Dyslipidaemia--hepatic and intestinal cross-talk.

    LENUS (Irish Health Repository)

    Tomkin, Gerald H

    2010-06-01

    Cholesterol metabolism is tightly regulated with the majority of de novo cholesterol synthesis occurring in the liver and intestine. 3 Hydroxy-3-methylglutaryl coenzyme A reductase, a major enzyme involved in cholesterol synthesis, is raised in both liver and intestine in diabetic animals. Niemann PickC1-like1 protein regulates cholesterol absorption in the intestine and facilitates cholesterol transport through the liver. There is evidence to suggest that the effect of inhibition of Niemann PickC1-like1 lowers cholesterol through its effect not only in the intestine but also in the liver. ATP binding cassette proteins G5\\/G8 regulate cholesterol re-excretion in the intestine and in the liver, cholesterol excretion into the bile. Diabetes is associated with reduced ATP binding cassette protein G5\\/G8 expression in both the liver and intestine in animal models. Microsomal triglyceride transfer protein is central to the formation of the chylomicron in the intestine and VLDL in the liver. Microsomal triglyceride transfer protein mRNA is increased in diabetes in both the intestine and liver. Cross-talk between the intestine and liver is poorly documented in humans due to the difficulty in obtaining liver biopsies but animal studies are fairly consistent in showing relationships that explain in part mechanisms involved in cholesterol homeostasis.

  1. Crosstalk between cartilage and bone: when bone cytokines matter.

    Science.gov (United States)

    Funck-Brentano, Thomas; Cohen-Solal, Martine

    2011-04-01

    The cartilage damage which characterizes osteoarthritis is often accompanied by bone lesions. Joint integrity results from the balance in the physiological interactions between bone and cartilage. Several local factors regulate the physiological remodeling of cartilage, the disequilibrium of these leading to a higher cartilage catabolism. Several cytokines secreted by bone cells can induce chondrocyte differentiation, which suggests their role in the dialogue between both cells. Accumulative in vivo evidence shows that increased bone resorption occurs at an early stage in the development of osteoarthritis and that blocking bone-resorbing cytokines prevents cartilage damage, confirming the role of bone factors in the crosstalk of both tissues. Recently, molecules of the Wnt pathway have emerged as key regulators of bone and cartilage. Activation of Wnt/βcatenin induces an imbalance in cartilage homeostasis, and agonists/antagonists of Wnt are potential candidates for this interaction. This review will summarize what is known about the contribution of bone cytokines to the physiological remodeling of cartilage and in the pathophysiology of osteoarthritis. PMID:21596615

  2. Host-Bacteria Crosstalk at the Dentogingival Junction

    Directory of Open Access Journals (Sweden)

    M. T. Pöllänen

    2012-01-01

    Full Text Available The dentogingival junction is of crucial importance in periodontal host defense both structurally and functionally. Oral bacteria exert a constant challenge to the host cells and tissues at the dentogingival junction. The host response is set up to eliminate the pathogens by the innate and adaptive defense mechanisms. In health, the commensal bacteria and the host defense mechanisms are in a dynamic steady state. During periodontal disease progression, the dental bacterial plaque, junctional epithelium (JE, inflammatory cells, connective tissue, and bone all go through a series of changes. The tissue homeostasis is turned into tissue destruction and progression of periodontitis. The classical study of Slots showed that in the bacterial plaque, the most remarkable change is the shift from gram-positive aerobic and facultatively anaerobic flora to a predominantly gram-negative and anaerobic flora. This has been later confirmed by several other studies. Furthermore, not only the shift of the bacterial flora to a more pathogenic one, but also bacterial growth as a biofilm on the tooth surface, allows the bacteria to communicate with each other and exert their virulence aimed at favoring their growth. This paper focuses on host-bacteria crosstalk at the dentogingival junction and the models studying it in vitro.

  3. Flavonoids Affect Host-Microbiota Crosstalk through TLR Modulation

    Directory of Open Access Journals (Sweden)

    Francisco J. Pérez-Cano

    2014-10-01

    Full Text Available Interaction between host cells and microbes is known as crosstalk. Among other mechanisms, this takes place when certain molecules of the micro-organisms are recognized by the toll-like receptors (TLRs in the body cells, mainly in the intestinal epithelial cells and in the immune cells. TLRs belong to the pattern-recognition receptors and represent the first line of defense against pathogens, playing a pivotal role in both innate and adaptive immunity. Dysregulation in the activity of such receptors can lead to the development of chronic and severe inflammation as well as immunological disorders. Among components present in the diet, flavonoids have been suggested as antioxidant dietary factors able to modulate TLR-mediated signaling pathways. This review focuses on the molecular targets involved in the modulatory action of flavonoids on TLR-mediated signaling pathways, providing an overview of the mechanisms involved in such action. Particular flavonoids have been able to modify the composition of the microbiota, to modulate TLR gene and protein expression, and to regulate the downstream signaling molecules involved in the TLR pathway. These synergistic mechanisms suggest the role of some flavonoids in the preventive effect on certain chronic diseases.

  4. A crosstalk of auxin and GA during tuber development.

    Science.gov (United States)

    Roumeliotis, Efstathios; Visser, Richard G F; Bachem, Christian W B

    2012-10-01

    Several hormones have been studied for their effect on tuber initiation and development. Until recently, the hormone with the most prominent role in tuber initiation was attributed to GA. Genes involved in GA degradation do exhibit an upregulated profile during early stages of tuber development, leading to a rapid decrease of active GA content, thereby facilitating stolon-tip swelling. While GA is known to be involved in shoot and stolon elongation, the development of the new tuberorgan requires changes in meristem identity and the reorientation ofthe plane of cell division. In other developmental processes, such as embryo patterning, flower development and lateral root initiation auxin plays a key role. Recent evidence on the involvement of auxin in tuber formation was providedby the measurement of auxin content in swelling stolons. Auxin content in the stolon tips increased several fold prior to tuber swelling. In vitro tuberisation experiments with auxin applications support the role of auxin during tuber initiation. Taken together, it is becoming clear that the initiation and induction of tubers in potato is a developmental process that appears to be regulated by a crosstalk between GA and auxin. PMID:22902700

  5. Phase-amplitude crosstalk in intensity modulated near infrared spectroscopy

    Science.gov (United States)

    Alford, K.; Wickramasinghe, Y.

    2000-05-01

    Near infrared spectroscopy (NIRS) instruments that rely on phase sensitive detection suffer from what is called "phase-amplitude crosstalk," i.e., the phase measured is dependent on the average light intensity entering the detector. Changes in detector rise time with input light intensity is the accepted explanation of this phenomenon. It is concluded here that an additional simple mechanism can cause phase-amplitude errors, particularly if the ratio of the ac component of the detected signal to the dc component is low. It is shown that the form of the phase distortion encountered during the development of a new phase sensitive NIR instrument can be modeled by assuming the presence of a synchronous interfering signal, due to rf coupling, at the detector output. This modeling allows a required margin between the detected signal of interest, i.e., the signal from the tissue and the interfering signal to be set in order to achieve a measured phase accuracy necessary to derive sufficiently accurate clinical parameters.

  6. Pituitary apoplexy presenting as isolated third cranial nerve palsy with ptosis : two case reports.

    Science.gov (United States)

    Cho, Won-Jin; Joo, Sung-Pil; Kim, Tae-Sun; Seo, Bo-Ra

    2009-02-01

    Pituitary apoplexy is a clinical syndrome caused by an acute ischemic or hemorrhagic vascular accident involving a pituitary adenoma or an adjacent pituitary gland. Pituitary apoplexy may be associated with a variety of neurological and endocrinological signs and symptoms. However, isolated third cranial nerve palsy with ptosis as the presenting sign of pituitary apoplexy is very rare. We describe two cases of pituitary apoplexy presenting as sudden-onset unilateral ptosis and diplopia. In one case, brain magnetic resonance imaging (MRI) revealed a mass in the pituitary fossa with signs of hemorrhage, upward displacement of the optic chiasm, erosion of the sellar floor and invasion of the right cavernous sinus. In the other case, MRI showed a large area of insufficient enhancement in the anterior pituitary consistent with pituitary infarction or Sheehan's syndrome. We performed neurosurgical decompression via a transsphenoidal approach. Both patients showed an uneventful recovery. Both cases of isolated third cranial nerve palsy with ptosis completely resolved during the early postoperative period. We suggest that pituitary apoplexy should be included in the differential diagnosis of patients presenting with isolated third cranial nerve palsy with ptosis and that prompt neurosurgical decompression should be considered for the preservation of third cranial nerve function. PMID:19274125

  7. Pituitary dysfunction in adult patients after cranial irradiation for head and nasopharyngeal tumours

    International Nuclear Information System (INIS)

    Background: Pituitary insufficiency after radiotherapy in the hypothalamic pituitary region is a well-known complication. However, endocrine assessments are not incorporated in the follow-up after cranial irradiation for head and neck tumours. Aim of the study: To evaluate pituitary function in patients cranially irradiated for non-pituitary tumours. Patients and methods: Evaluation of pituitary function in all available patients treated at our centre with cranial radiotherapy for head and neck tumours. Results: We included 80 patients. Forty patients were treated for cerebral tumours, 15 for nasopharyngeal tumours, and 25 for different tumours like meningioma or cerebral metastasis. Mean age was 47.5 (18.6–89.7) years. Mean radiation dose delivered at the pituitary region was 56.27 Gy (40.0–70.0). Pituitary insufficiency was present in 16 patients within 2 years after irradiation 23/49 patients (47%) after 5 years and 27/45 (60%) after 10 years and 31/35 patients (89%) after 15 years. Conclusion: Pituitary insufficiency is highly prevalent in adult patients treated with cranial radiotherapy for head and nasopharyngeal tumours. These prevalence rates are comparable to those observed after radiotherapy for pituitary tumours. Because hormone replacement of endocrine deficits improves quality of life and prevents potential severe complications, such as Addisonian crises, periodical evaluation of pituitary function is advocated

  8. A model for evaluating steroids acting at the hypothalamus-pituitary axis using radioimmunoassay and related procedures

    International Nuclear Information System (INIS)

    The relative affinity constants for binding of estrone (E1), estriol (E3), 17β-estradiol(E2) and 17α-ethinyl-17β-estradiol(EE2) to cytosol estrogen-receptors of rat hypothalamus and pituitary were estimated by a radioligand-receptor assay procedure. The relative affinity constants in the hypothalamic system were 6.5x10-10 M for E2, 1x10-9 M for EE2 and 2x10-8 M for E1 and E3. The affinity constants were 1x10-9 M for E2 and E3 and 7x10-9 M for E1 and E3 when pituitary cytosol samples were used. Some discrepancies between biological activity and affinity for the estrogen-receptor were noted. These may be due to differences in the metabolism and cellular uptake of the estrogens. The radioligand-receptor assay procedure may be useful in evaluating the action of estrogens and anti-estrogens acting at the hypothalamic and pituitary level. Sedimentation patterns of cytosol samples labelled with the estrogens used in this study revealed, upon ultracentrifugation, protein moieties sedimenting in the 8 S region. The potency of progesterone and D-Norgestrel to modulate the release of LH and FSH stimulated by luteinizing hormone-releasing hormone (LH-RH) in castrated female rats was found to correlate well with the biological activity of the progestogens. It is concluded that the radioligand-receptor assay procedure for estrogens and the in-vivo model for the evaluation of the central action of progestogens may be valuable tools for testing new steroids to be used in oral contraceptives. (author)

  9. ELEVATED SOLUBLE EPIDERMAL GROWTH FACTOR RECEPTOR LEVEL IN PITUITARY ADENOMA AND CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    Yan-guo Kong; Zu-yuan Ren; Chang-bao Su; Ren-zhi Wang; Wen-bing Ma; Wei Lian

    2004-01-01

    Objective To investigate effect of the soluble epidermal growth factor receptor (sEGFR/sErbB1) level in the peripheral blood in development, invasiveness, apoplexy of each type of pituitary tumor.Methods The sEGFR level was determined in peripheral serum from 190 patients with pituitary diseases by enzyme linked immunosobent assay. The sEGFR levels were measured in 10 pituitary Rathke's pouch, 18 pituitary hyperplasia, 161pituitary adenomas including 30 microadenomas, 83 large adenomas, 48 giant adenomas, 1 pituitary carcinoma, and 28 healthy controls.Results In the patients with pituitary hyperplasia, microadenoma, large adenoma, giant adenoma, and pituitary carcinoma, the sEGFR level was 188.92 + 32.62, 209.83 + 19.01,333.20 + 69.33, 405.85 + 37.38, and 617.45 fmol/mL independently. They were all significantly higher than patients with pituitary Rathke's pouch (156.78 + 18.24 fmol/mL, P < 0.001)and healthy control group (159.11 +40.50 fmol/mL, P < 0.05). The sEGFR level in pituitary carcinoma was higher than pituitary adenoma. In patients with pituitary adenoma, the sEGFR level was positive correlated to the size of pituitary adenomas (r = 0.998), the significant difference was observed for the sEGFR level in each group of the patients with pituitary adenomas (P < 0.001). Furthermore, in patients with pituitary ACTH-secrefing microadenomas, the serum sEGFR levels in invasiveness (295.00+77.80 fmol/mL) was higher than that in non-invasiveness (210.60+ 16.4 fmol/mL, P < 0.05). In patients with pituitary ACTH-secreting, PRL-secreting, GH-secreting, and non-functioning large adenomas, the serum sEGFR levels in invasiveness (407.86 + 28.50, 399.25 + 30.10, 386.00 + 13.08, and 369.25 + 36.70 fmol/mL) was higher than that in non-invasiveness (335.25 +63.49, 300.64+47.57, 297.00+61.93, and 269.30+25.68 fmol/mL) respectively (P < 0.05). In patients with invasive pituitary PRL-secreting, GH-secreting, and non-functioning giant adenomas, the serum sEGFR levels not

  10. Sustained remission of Cushing's disease with mitotane and pituitary irradiation

    International Nuclear Information System (INIS)

    Low doses of mitotane were given orally to 36 patients with Cushing's disease, concurrently with or after pituitary cobalt irradiation. Clinical and biochemical remission occurred in 29. The response to treatment occurred early in 17 patients and late in 12. The different pattern of response to mitotane was not related to the dose given or to its serum level. Early biochemical indicators of adrenal suppression with mitotane were a sharp decrease in adrenal response to the infusion of ACTH and in plasma levels of dehydroepiandrosterone sulfate. Although mitotane was given together with pituitary irradiation, initial remission was due mainly to the adrenal effect of mitotane. Plasma ACTH levels were still elevated when cortisol had returned to normal. In seventeen of the 29 patients who responded to treatment drug therapy has been discontinued, and they remain in remission of Cushing's syndrome. Side-effects have been dose dependent, with anorexia, nausea, decreased memory, and gynecomastia in men being the commonest

  11. Gonadal steroid hormones and the hypothalamo-pituitary-adrenal axis.

    Science.gov (United States)

    Handa, Robert J; Weiser, Michael J

    2014-04-01

    The hypothalamo-pituitary-adrenal (HPA) axis represents a complex neuroendocrine feedback loop controlling the secretion of adrenal glucocorticoid hormones. Central to its function is the paraventricular nucleus of the hypothalamus (PVN) where neurons expressing corticotropin releasing factor reside. These HPA motor neurons are a primary site of integration leading to graded endocrine responses to physical and psychological stressors. An important regulatory factor that must be considered, prior to generating an appropriate response is the animal's reproductive status. Thus, PVN neurons express androgen and estrogen receptors and receive input from sites that also express these receptors. Consequently, changes in reproduction and gonadal steroid levels modulate the stress response and this underlies sex differences in HPA axis function. This review examines the make up of the HPA axis and hypothalamo-pituitary-gonadal (HPG) axis and the interactions between the two that should be considered when exploring normal and pathological responses to environmental stressors. PMID:24246855

  12. MR imaging of growth hormone-secreting pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Masayuki; Ueda, Fumiaki; Fujinaga, Yasunari [Kanazawa Univ. (Japan). School of Medicine] (and others)

    2000-11-01

    We evaluated MR imaging of 51 growth hormonesecreting pituitary adenomas. On T1WI, 22 tumors were isointense with gray matter (GM), nine isointense with GM and white matter (WM), 14 isointense with WM, and six more hyperintense than WM. On T2WI of 45 patients, only fifteen tumors showed hypointensity than WM, 10 were isointense with WM, eight isointense with GM and WM, 12 showed in part isointensity with GM, and one was more hyperintense than GM. The dynamic study demonstrated the tumor more clearly than the delayed study in 10, while the opposite was true for two patients. The dynamic study is inevitable for MR imaging of GH-secreting pituitary adenomas. (author)

  13. Radiosurgery for pituitary adenomas; Radiocirurgia nos adenomas hipofisarios

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Douglas Guedes de; Salvajoli, Joao Victor; Canteras, Miguel Montes; Cecilio, Soraya A. Jorge [Instituto de Radiocirurgia Neurologica, Sao Paulo, SP (Brazil)]. E-mail: dougguedes@uol.com.br

    2006-12-15

    Pituitary adenomas represent nearly 15% of all intracranial tumors. Multimodal treatment includes microsurgery, medical management and radiotherapy. Microsurgery is the primary recommendation for nonfunctioning and most of functioning adenomas, except for prolactinomas that are usually managed with dopamine agonist drugs. However, about 30% of patients require additional treatment after microsurgery for recurrent or residual tumors. In these cases, fractionated radiation therapy has been the traditional treatment. More recently, radiosurgery has been established as a treatment option. Radiosurgery allows the delivery of prescribed dose with high precision strictly to the target and spares the surrounding tissues. Therefore, the risks of hypopituitarism, visual damage and vasculopathy are significantly lower. Furthermore, the latency of the radiation response after radiosurgery is substantially shorter than that of fractionated radiotherapy. The goal of this review is to define the efficacy, safety and role of radiosurgery for treatment of pituitary adenomas and to present the preliminary results of our institution. (author)

  14. Transsphenoidal pituitary resection with intraoperative MR guidance: preliminary results

    Science.gov (United States)

    Pergolizzi, Richard S., Jr.; Schwartz, Richard B.; Hsu, Liangge; Wong, Terence Z.; Black, Peter M.; Martin, Claudia; Jolesz, Ferenc A.

    1999-05-01

    The use of intraoperative MR image guidance has the potential to improve the precision, extent and safety of transsphenoidal pituitary resections. At Brigham and Women's Hospital, an open-bore configuration 0.5T MR system (SIGNA SP, GE Medical Systems, Milwaukee, WI) has been used to provide image guidance for nine transsphenoidal pituitary adenoma resections. The intraoperative MR system allowed the radiologist to direct the surgeon toward the sella turcica successfully while avoiding the cavernous sinus, optic chiasm and other sensitive structures. Imaging performed during the surgery monitored the extent of resection and allowed for removal of tumor beyond the surgeon's view in five cases. Dynamic MR imaging was used to distinguish residual tumor from normal gland and postoperative changes permitting more precise tumor localization. A heme-sensitive long TE gradient echo sequence was used to evaluate for the presence of hemorrhagic debris. All patients tolerated the procedure well without significant complications.

  15. Progress in the diagnosis and classification of pituitary adenomas

    Directory of Open Access Journals (Sweden)

    Luis V Syro

    2015-06-01

    Full Text Available Pituitary adenomas are common neoplasms. Their classification is based upon size, invasion of adjacent structures, sporadic or familial cases, biochemical activity, clinical manifestations, morphological characteristics, response to treatment and recurrence. Although they are considered benign tumors, some of them are difficult to treat due to their tendency to recur, despite standardized treatment. Functional tumors present other challenges for normalizing their biochemical activity. Novel approaches for early diagnosis as well as different perspectives on classification may help to identify subgroups of patients with similar characteristics, creating opportunities to match each patient with the best personalized treatment option. In this paper we present the progress in the diagnosis and classification of different subgroups of patients with pituitary tumors that may be managed with specific considerations according to their tumor subtype.

  16. Heterogeneity of secretory granules of silent pituitary adenomas

    DEFF Research Database (Denmark)

    Holck, S; Wewer, U M; Albrechtsen, R

    1988-01-01

    Silent pituitary adenomas were compared with hormonally active tumors taking into account the size, number, and ultrastructural characteristics of secretory granules (SG). The study group (a total of 79 primary pituitary adenomas) comprised 27 silent, 21 growth hormone (GH)-producing-, 16 prolactin...... (PRL)-producing-, 5 GH-PRL-producing- and 10 adrenocorticotropic hormone (ACTH)-producing adenomas. The SG of silent adenomas were significantly smaller than SG in endocrine active adenomas. All hormonally inactive tumors also contained small (mean, 94 nm) specific cytoplasmic granules, designated...... "silent adenoma granules" (SIG). The fine structural features of the SIG included: a flocculent, granular material occupying an eccentric position in a larger vesicle limited by a double membrane. In the silent adenomas this particular granule was present in up to 90% of the adenoma cells and constituted...

  17. Growth hormone receptor expression and function in pituitary adenomas

    DEFF Research Database (Denmark)

    Clausen, Lene R; Kristiansen, Mikkel T; Rasmussen, Lars M;

    2004-01-01

    OBJECTIVE AND DESIGN: Hypopituitarism, in particular GH deficiency, is prevalent in patients with clinically nonfunctioning pituitary adenomas (NFPAs) both before and after surgery. The factors regulating the growth of pituitary adenomas in general and residual tumour tissue in particular are not...... transcription 5) phosphorylation was measured by Western blot analysis as an index of GHR signalling; cell proliferation was evaluated by [H3]-thymidine incorporation and glycoprotein hormone production analysed by radioimmunoassay (RIA). RESULTS: All adenomas investigated expressed the GHR, but there was no...... detection of STAT5 phosphorylation. Overall, GH and IGF-I administration did not significantly stimulate cell proliferation in vitro, although some individual adenomas exhibited a proliferative response to various extents. GH also did not significantly influence glycoprotein hormone secretion in vitro...

  18. Recurrence of chromophobe pituitary adenomas after operation and postoperative radiotherapy

    International Nuclear Information System (INIS)

    The rate of recurrence is reported in a prospective study of 56 patients (28 men, 28 women) with large chromophobe pituitary adenoma (with or without hyperprolactinemia). The surgical approach was transfrontal in 44 and transseptospehnoidal in 12 patients. Cryoapplication was combined with the transsphenoidal operation. All but one patient received postopertive pituitary irradiation. Altogether, 11 (20 %) clinical relapses (10 men) occurred between 0.5 and 6 years after the transfrontal operation. Patients that relapsed had had larger tumors than those remaining in remission. Occurence of the tumors appeared with a deterioration of the visual field defect in 9 patients. There were no differences in the degrees of hypopituitarism in patients who relapsed as compared to patients remaining in remission. (author)

  19. Recurrence of chromophobe pituitary adenomas after operation and postoperative radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Salmi, J.; Pelkonen, R. (Third Department of Medicine, University of Helsinki, Finland); Grahne, B. (Department of Otorhinolaryngology, University oF Helsinki, finland); Valtonen, S. (Department of Neurosurgery, University of Helsinki, Finland)

    1982-01-01

    The rate of recurrence is reported in a prospective study of 56 patients (28 men, 28 women) with large chromophobe pituitary adenoma (with or without hyperprolactinemia). The surgical approach was transfrontal in 44 and transseptospehnoidal in 12 patients. Cryoapplication was combined with the transsphenoidal operation. All but one patient received postopertive pituitary irradiation. Altogether, 11 (20 %) clinical relapses (10 men) occurred between 0.5 and 6 years after the transfrontal operation. Patients that relapsed had had larger tumors than those remaining in remission. Occurence of the tumors appeared with a deterioration of the visual field defect in 9 patients. There were no differences in the degrees of hypopituitarism in patients who relapsed as compared to patients remaining in remission.

  20. Electrophoretic analyses of proteins transported to the rat posterior pituitary

    International Nuclear Information System (INIS)

    [35S] cysteine, [3H] methionine, or [3H] fucose were injected into the supraoptic nuclei (SON) of rats, and the labelled proteins that were transported to and accumulated in the posterior pituitary 24 h post-injection were analyzed electrophoretically. The transported, labelled proteins which were soluble in 0.1 M-HCl were primarily of low molecular weight (about 12,000 on SDS gels). However, the selectivity of labelling of these proteins by the three different labelled precursors could be revealed by isoelectric focusing. The 0.1 M-HCl insoluble labelled proteins, presumably reflecting membrane proteins transported from the SON to the pituitary, were more diverse and generally of higher molecular weight (> 43,000 on SDS gels). (author)

  1. Oestrogen-androgen crosstalk in the pathophysiology of erectile dysfunction

    Institute of Scientific and Technical Information of China (English)

    BSrilatha; PGAdaikan

    2003-01-01

    Ageing in man is associated with a decline in testosterone following changes in the hypothalamo-pituitary-testicular axis. This may offset the physiologic equilibrium between oestrogen and androgen and at some point when the ratio of free testosterone to oestradiol reaches a critical level, the oestrogenic gonadotropin suppressive effect predominates with decreased release of FSH and LH. Adding to this endocrinal complexity is the continued peripheral conversion to oestradiol through aromatisation. Although the androgen deficiency is not the sole cause for impotence in the elderly, there is a gradual decrease in nocturnal penile tumescence (NPT) and spontaneous morning erections with ageing. Despite the age related increase in oestrogen levels, the information on the pathophysiological role of the "female hormone" in erectile dysfunction has been scanty. Together with our identification of oestrogen receptors within the penile cavernosum, we have delineated dysfunctional changes on male erection mediated by oestradiol.These findings parallel the recent concerns over environmental oestrogens on fertility declines in young men. Oestrogenic activity is also present in plants and thereby in human diet. These phytoestrogens are structurally and functionally similar to oestradiol and more potent than the environmental oestrogenic chemicals such as organochlorine and phenolic compounds. Thus in the light of growing concerns of possible compromising effects on sexuality by endogenous and environmental oestrogens, we are faced with the scientific need to delineate their role on the mechanism of male erectile pathway in health and disease for clinical correlates and prognostics.

  2. Methamphetamine and the hypothalamic-pituitary-adrenal axis

    OpenAIRE

    Zuloaga, Damian G.; Jacosbskind, Jason S.; Raber, Jacob

    2015-01-01

    Psychostimulants such as methamphetamine (MA) induce significant alterations in the function of the hypothalamic-pituitary-adrenal (HPA) axis. These changes in HPA axis function are associated with altered stress-related behaviors and might contribute to addictive processes such as relapse. In this mini-review we discuss acute and chronic effects of MA (adult and developmental exposure) on the HPA axis, including effects on HPA axis associated genes/proteins, brain regions, and behaviors such...

  3. Flow cytometric immunofluorescence of rat anterior pituitary cells

    Science.gov (United States)

    Hatfield, J. Michael; Hymer, W. C.

    1985-01-01

    A flow cytometric immunofluorescence technique was developed for the quantification of growth hormone, prolactin, and luteinizing hormone producing cells. The procedure is based on indirect-immunofluorescence of intracellular hormone using an EPICS V cell sorter and can objectively count 50,000 cells in about 3 minutes. It can be used to study the dynamics of pituitary cell populations under various physiological and pharmacological conditions.

  4. Hypothalamic-Pituitary Autoimmunity and Traumatic Brain Injury

    OpenAIRE

    Federica Guaraldi; Silvia Grottoli; Emanuela Arvat; Ezio Ghigo

    2015-01-01

    Background: Traumatic brain injury (TBI) is a leading cause of secondary hypopituitarism in children and adults, and is responsible for impaired quality of life, disabilities and compromised development. Alterations of pituitary function can occur at any time after the traumatic event, presenting in various ways and evolving during time, so they require appropriate screening for early detection and treatment. Although the exact pathophysiology is unknown, several mechanisms have been hypoth...

  5. Chronic stress and pituitary-adrenal function in female pigs.

    OpenAIRE

    Janssens, C.J.J.C.

    1994-01-01

    IntroductionThe main purpose of the studies described in this thesis was to gain more insight in the regulation of the hypothalamic-pituitary-adrenocorticaI (HPA) system and the mechanisms underlying adaptation to chronic stress in female pigs. The function of the HPA axis, which coordinates multiple neuroendocrine and metabolic responses to stressors, has been subject of extensive basic and clinical research. HPA-activation by stressful stimuli results in an increase in circulating adrenocor...

  6. Metastatic pituitary carcinoma: a case report and review of literature

    Directory of Open Access Journals (Sweden)

    ZHANG Shang-fu

    2013-02-01

    Full Text Available Background As a kind of rare tumor, metastatic pituitary carcinoma is very difficult to diagnose clinically and is easy to be misdiagnosed. This article aims to discuss the clinical manifestations and histopathological features of this tumor. Methods The clinical presentations, histopathological features and immunophenotype were studied in one case of poorly differentiated lung adenocarcinoma metastatic to pituitary gland, and related literature was reviewed. Results A 47-year-old woman mainly presented with faint, headache and blurred vision. CT scan demonstrated abnormal signals in suprasellar cistern. During the resection, the tumor could be seen locating in sellar region, the size of which was about 2 cm × 1 cm × 1 cm. Histopathological examination revealed that the structure of pituitary gland was damaged and the tumor was composed of atypical round or oval cells arranged in nest or glandular patterns, in which a number of enlarged plump tumor cells contained abundant eosinophilic cytoplasm with eccentrical caryogenesis. The immunohistochemistry showed that epithelial membrane antigen (EMA, pan cytokeratin (PCK, thyroid transcription factor-1 (TTF-1 and cytokeratin 7 (CK7 were positive in tumor cells with Ki-67 labeling index being 15%, but chromogranin (CgA, cancer embryo antigen (CEA, human chorionic gonadotropin (hCG, placental alkaline phosphatase (PLAP, CD117, leukocyte common antigen (LCA, CD30, anaplastic lymphoma kinase-1 (ALK-1 were negative in tumor cells. After operation the patient received treatment with levothyroxine sodium and γ knife, but died 4 months later. Conclusion Histopathological examination and immunohistochemistry can confirm the diagnosis of metastatic pituitary carcinoma and locate the primary lesion. Postoperative comprehensive therapy is necessary.

  7. Lymphocytic Adenohypophysitis Simulating a Pituitary Adenoma in a Pregnant Woman

    OpenAIRE

    Talan-Hranilović, J.; Gnjidić, Ž.; Sekso, M.; Berković, M.; Altabas, V.; Rumboldt, Z.

    2002-01-01

    The lymphocytic hypophysitis, appearing in women during the third trimester of pregnancy or early post-partum period, is a rare cause of hypopituitarism and pituitary enlargement. A 39 year-old woman presented in the 37th week of pregnancy with bilateral heteronymous quadrantanopsia, CT indicative of tumorous mass and symptoms of hypopituitarism with decreased thyroid hormone and thyrotrophin levels, and low normal level of cortisol. After the birth of a healthy male child the ...

  8. A pituitary abscess masquerading as recurrent hypernatremia and aseptic meningitis

    OpenAIRE

    Gonzales, Michael; Marik, Paul Ellis; Khardori, Romesh K.; O'Brian, John T

    2012-01-01

    Pituitary abscess is a rare condition. In the setting of multiple surgical interventions, the risk of its development increases. A 49-year-old man presented with episodes of altered mental status. He had two surgeries for a recurrent suprasellar arachnoid cyst. The second surgery was complicated by a persistent cerebrospinal fluid (CSF) leak that required two repairs following which he developed panhypopituitarism and central diabetes insipidus. Twelve months after his last surgery he was dia...

  9. Analysis and modeling of optical crosstalk in InP-based Geiger-mode avalanche photodiode FPAs

    Science.gov (United States)

    Chau, Quan; Jiang, Xudong; Itzler, Mark A.; Entwistle, Mark; Piccione, Brian; Owens, Mark; Slomkowski, Krystyna

    2015-05-01

    Optical crosstalk is a major factor limiting the performance of Geiger-mode avalanche photodiode (GmAPD) focal plane arrays (FPAs). This is especially true for arrays with increased pixel density and broader spectral operation. We have performed extensive experimental and theoretical investigations on the crosstalk effects in InP-based GmAPD FPAs for both 1.06-μm and 1.55-μm applications. Mechanisms responsible for intrinsic dark counts are Poisson processes, and their inter-arrival time distribution is an exponential function. In FPAs, intrinsic dark counts and cross talk events coexist, and the inter-arrival time distribution deviates from purely exponential behavior. From both experimental data and computer simulations, we show the dependence of this deviation on the crosstalk probability. The spatial characteristics of crosstalk are also demonstrated. From the temporal and spatial distribution of crosstalk, an efficient algorithm to identify and quantify crosstalk is introduced.

  10. Human Pituitary Adenoma Proteomics: New Progresses and Perspectives.

    Science.gov (United States)

    Zhan, Xianquan; Wang, Xiaowei; Cheng, Tingting

    2016-01-01

    Pituitary adenoma (PA) is a common intracranial neoplasm that impacts on human health through interfering hypothalamus-pituitary-target organ axis systems. The development of proteomics gives great promises in the clarification of molecular mechanisms of a PA and discovery of effective biomarkers for prediction, prevention, early-stage diagnosis, and treatment for a PA. A great progress in the field of PA proteomics has been made in the past 10 years, including (i) the use of laser-capture microdissection, (ii) proteomics analyses of functional PAs (such as prolactinoma), invasive and non-invasive non-functional pituitary adenomas (NFPAs), protein post-translational modifications such as phosphorylation and tyrosine nitration, NFPA heterogeneity, and hormone isoforms, (iii) the use of protein antibody array, (iv) serum proteomics and peptidomics, (v) the integration of proteomics and other omics data, and (vi) the proposal of multi-parameter systematic strategy for a PA. This review will summarize these progresses of proteomics in PAs, point out the existing drawbacks, propose the future research directions, and address the clinical relevance of PA proteomics data, in order to achieve our long-term goal that is use of proteomics to clarify molecular mechanisms, construct molecular networks, and discover effective biomarkers. PMID:27303365

  11. Human pituitary adenoma proteomics: new progresses and perspectives

    Directory of Open Access Journals (Sweden)

    Xianquan eZhan

    2016-05-01

    Full Text Available Pituitary adenoma (PA is a commonly intracranial neoplasm that impacts on human health through interfering hypothalamus-pituitary-target organ axis systems. The development of proteomics gives great promises in clarification of molecular mechanisms of a pituitary adenoma and discovery of effective biomarkers for prediction, prevention, early-stage diagnosis and treatment of a PA. A great progress in the field of PA proteomics has been made in the past ten years, including (i the use of laser capture microdissection, (ii proteomics analyses of functional PAs (FPAs, such as prolactinoma, invasive and noninvasive nonfunctional PAs (NFPAs, protein post-translational modifications (PTMs including phosphorylation and tyrosine nitration, NFPA heterogeneity, and hormone isoforms, (iii the use of protein antibody array, (iv serum proteomics and peptidomics, (v integration of proteomics and other omics data, and (vi proposal of multi-parameter systematic strategy for a PA. This review will summarize those progresses of proteomics in PAs, point out the existing drawbacks, propose the future research directions, and address the clinical relevance of PA proteomics data, in order to achieve our long-term goal that is use of proteomics to clarify molecular mechanisms, construct molecular networks, and discover effective biomarkers.

  12. Feeding Frequency Affects Cultured Rat Pituitary Cells in Low Gravity

    Science.gov (United States)

    Hymer, W. C.; Grindeland, R. E.; Salada, T.; Cenci, R.; Krishnan, K.; Mukai, C.; Nagaoka, S.

    1996-01-01

    In this report, we describe the results of a rat pituitary cell culture experiment done on STS-65 in which the effect of cell feeding on the release of the six anterior pituitary hormones was studied. We found complex microgravity related interactions between the frequency of cell feeding and the quantity and quality (i.e. biological activity) of some of the six hormones released in flight. Analyses of growth hormone (GH) released from cells into culture media on different mission days using gel filtration and ion exchange chromatography yielded qualitatively similar results between ground and flight samples. Lack of cell feeding resulted in extensive cell clumping in flight (but not ground) cultures. Vigorous fibroblast growth occurred in both ground and flight cultures fed 4 times. These results are interpreted within the context of autocrine and or paracrine feedback interactions. Finally the payload specialist successfully prepared a fresh trypsin solution in microgravity, detached the cells from their surface and reinserted them back into the culture chamber. These cells reattached and continued to release hormone in microgravity. In summary, this experiment shows that pituitary cells are microgravity sensitive and that coupled operations routinely associated with laboratory cel1 culture can also be accomplished in low gravity.

  13. Electrophoretic separation of kidney and pituitary cells on STS-8

    Science.gov (United States)

    Morrison, D. R.; Nachtwey, D. S.; Barlow, G. H.; Cleveland, C.; Lanham, J. W.; Farrington, M. A.; Hatfield, J. M.; Hymer, W. C.; Todd, P.; Wilfinger, W.; Grindeland, R.; Lewis, M. L.

    A Continuous Flow Electrophoresis System (CFES) was used on Space Shuttle flight STS-8 to separate specific secretory cells from suspensions of cultured primary human embryonic kidney cells and rat pituitary cells. The objectives were to isolate the subfractions of kidney cells that produce the largest amounts of urokinase (plasminogen activator), and to isolate the subfractions of rat pituitary cells that secrete growth hormone, prolactin, and other hormones. Kidney cells were separated into more than 32 fractions in each of two electrophoretic runs. Electrophoretic mobility distributions in flight experiments were spread more than the ground controls. Multiple assay methods confirmed that all cultured kidney cell fractions produced some urokinase, and five to six fractions produced significantly more urokinase than the other fractions. Several fractions also produced tissue plasminogen activator. The pituitary cells were separated into 48 fractions in each of the two electrophoretic runs, and the amounts of growth hormone (GH) and prolactin (PRL) released into the medium for each cell fraction were determined. Cell fractions were grouped into eight mobility classes and immunocytochemically assayed for the presence of GH, PRL, ACTH, LH, TSH, and FSH. The patterns of hormone distribution indicate that the specialized cells producing GH and PRL are isolatable due to the differences in electrophoretic mobilities.

  14. The value of radiation therapy for pituitary tumors

    International Nuclear Information System (INIS)

    Following points are discussed in this review. 1) Historical review of our previous therapeutic management. 2) Classification of pituitary adenomas. 3) Clinical analysis of my recent 58 cases. 4) Verification of usefulness of postoperative irradiation which achieved to increase in local control rate. 5) Authoritativeness of radiotherapy. In general, 3 to 4 portal technique or arc therapy were employed. The lateral opposing field technique was avoid to use. The recommended doses using linear accelerator x-ray technique is approximately 5000 cGy in 5 weeks. To prevent radiation hazard; (1) examiner should not use technique of two opposed fields, (2) total doses should not exceed 5000 cGy in 5 to 6 weeks and the use of daily fractions should not exceed 200 cGy. 6) Correlation of hormone secreting tumors and radiation therapy. 7) Problem of radiosurgery and heavy particle. 8) Countermeasure for recurrence cases. 9) Problem of side effects of radiotherapy and its precaution. Complication of radiation for pituitary adenoma found that the significant side effects are negligibly small in recent years. 10) Pituitary tumor are originally slow growing and benign tumor, therefore the response to irradiation takes long time to elapse for final evaluation. For instance, over 80 to 90% of acromegaly patients respond HGH successfully, but this may require from one to several years. 11) Conclusion. (author)

  15. Expression of p53 protein in pituitary adenomas

    Directory of Open Access Journals (Sweden)

    Oliveira M.C.

    2002-01-01

    Full Text Available Inactivating mutations of TP53, a tumor suppressor gene, are associated with abnormal cell proliferation. Although p53 expression is common in many human malignancies, p53 protein has seldom been evaluated in pituitary tumors. When detected, the percentage of p53-positive cells is low, and, in general, it is exclusive for invasive lesions. The aim of the present study was to use immunohistochemistry to determine the presence of p53 protein in pituitary adenomas from tumor samples of 163 surgeries performed in 148 patients (40% male, 60% female. In 35% of the cases the adenoma was nonfunctional, while in the others it was associated with PRL, GH and/or ACTH endocrine hypersecretion syndrome. Macroadenomas were observed in 83.2% of the cases with available neuroimage evaluation, of which 28% invaded the cavernous, sphenoid and/or ethmoidal sinus, bone, third ventricle or subfrontal lobe. p53 protein was detected in 2/148 patients (1.3%. Immunohistochemistry was positive for PRL and GH in these cases. Due to the high percentage of invasive pituitary adenomas found in our study, the low frequency of p53 detection suggests that it is inadequate as a routine marker for aggressiveness and as a predictive factor of tumor behavior.

  16. Thyrotropin-secreting pituitary adenomas: epidemiology, diagnosis, and management.

    Science.gov (United States)

    Amlashi, Fatemeh G; Tritos, Nicholas A

    2016-06-01

    Inappropriate secretion of TSH was first described in 1960 in a patient with evidence of hyperthyroidism and expanded sella on imaging. It was later found that a type of pituitary adenoma that secretes TSH (thyrotropinoma) was the underlying cause. The objective of the present review article is to summarize data on the epidemiology, pathogenesis, diagnosis, and management of thyrotropinomas. The prevalence of thyrotropinomas is lower than that of other pituitary adenomas. Early diagnosis is now possible thanks to the availability of magnetic resonance imaging and sensitive laboratory assays. As a corollary, many patients now present earlier in the course of their disease and have smaller tumors at the time of diagnosis. Treatment also has evolved over time. Transsphenoidal surgery is still considered definitive therapy. Meanwhile, radiation therapy, including radiosurgery, is effective in achieving tumor control in the majority of patients. In the past, radiation therapy was used as second line treatment in patients with residual or recurrent tumor after surgery. However, the availability of somatostatin analogs, which can lead to normalization of thyroid function as well as shrink these tumors, has led to an increase in the role of medical therapy in patients who are not in remission after pituitary surgery. In addition, dopamine agonists have shown some efficacy in the management of these tumors. Better understanding of the molecular pathogenesis of thyrotropinomas may lead to rationally designed therapies for patients with thyrotropinomas. PMID:26792794

  17. Clinicopathologic analysis of pituitary adenoma: a single institute experience.

    Science.gov (United States)

    Cho, Hwa Jin; Kim, Hanna; Kwak, Yoon Jin; Seo, Jeong Wook; Paek, Sun Ha; Sohn, Chul-Ho; Yun, Jung Min; Kim, Da Seu Ran; Kang, Peter; Park, Peom; Park, Sung-Hye

    2014-03-01

    Pituitary adenoma (PA) is a common benign neuroendocrine tumor; however, the incidence and proportion of hormone-producing PAs in Korean patients remain unknown. Authors analyzed 506 surgically resected and pathologically proven pituitary lesions of the Seoul National University Hospital from 2006 to 2011. The lesions were categorized as: PAs (n = 422, 83.4%), Rathke's cleft cysts (RCCs) (n = 54, 10.6%), inflammatory lesions (n = 8, 1.6%), meningiomas (n = 4), craniopharyngiomas (n = 4), granular cell tumors (n = 1), metastatic renal cell carcinomas (n = 2), germinomas (n = 1), ependymomas (n = 1), and unsatisfactory specimens (n = 9, 1.8%). PAs were slightly more prevalent in women (M: F = 1:1.17) with a mean age of 48.8 yr (9-80 yr). Immunohistochemical analysis revealed that prolactin-producing PAs (16.6%) and growth hormone-producing adenomas (9.2%) were the most common functional PAs. Plurihormonal PAs and nonfunctioning (null cell) adenomas were found in 14.9% and 42.4% of patients with PAs, respectively. The recurrence rate of PAs was 11.1%, but nearly 0% for the remaining benign lesions such as RCCs. 25.4% of patients with PAs were treated by gamma-knife after surgery due to residual tumors or regrowth of residual tumor. In conclusion, the pituitary lesions and the proportions of hormone-producing PAs in Korean patients are similar to those of previous reports except nonfunctioning (null cell) PAs, which are unusually frequent. PMID:24616591

  18. Hypothalamo-pituitary function after therapy for cancer

    International Nuclear Information System (INIS)

    Cranial irradiation may result in altered hypothalamo-pituitary function in patients treated for cancer distant from this area. Growth hormone (GH) deficiency is the most frequent complication. The frequency, delay of occurrence and severity of GH deficiency depend on the irradiation dose delivered to this area. The other factors influencing the frequency are the age at irradiations and the fractionation schedule. The frequency of other hypothalamo-pituitary changes is also dose-dependent: thyrotropin and gonadotropin deficiencies occur in 50-60% of cases after 50 Gray, and corticotrophin deficiency in 30%. Low dose cranial irradiations may also induce precocious puberty (onset < 8 yr in girls and < 10 yr in boys). The radiation-induced lesions seem to occur in the hypothalamus rather than in the pituitary. There is generally a good correlation between the GH peak and the growth velocity, but there may be normal growth in spite of GH deficiency after low dose or due to precocious puberty, decreased growth velocity in spite of normal GH peak, due to bone irradiation. Results on final height have been optimized by a better indication of GH therapy and by its association with treatment of precocious puberty. (author). 19 refs

  19. Modelling cellular behaviour

    Science.gov (United States)

    Endy, Drew; Brent, Roger

    2001-01-01

    Representations of cellular processes that can be used to compute their future behaviour would be of general scientific and practical value. But past attempts to construct such representations have been disappointing. This is now changing. Increases in biological understanding combined with advances in computational methods and in computer power make it possible to foresee construction of useful and predictive simulations of cellular processes.

  20. MR measurement of normal pituitary gland height on midsagittal section: Age and sex differentiation

    International Nuclear Information System (INIS)

    Measurement of the normal pituitary gland height was performed on magnetic resonance (MR) images of 144 subjects with no known or suspected pituitary or hypothalamic diseases. Midsagittal T1 weighted images(T1WI) were used for measurement, and mean vertical height according to age and sex group was obtained. In all age groups, the pituitary height was greater in females than in male. The group of 0-9 years in both genders showed the minimum mean pituitary height. The maximum mean height was observed in the 10-19 years age group in both genders. The height gradually decreases with increasing age after age 20 years. There was no subject with a height more than 9.0 mm in females or 8.0 mm in males. In conclusion the measurement of the normal pituitary gland height using mid-sagittal MR imaging can be used for the evaluation of the pituitary gland lesions

  1. Crosstalk between Wnt Signaling and RNA Processing in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Michael Bordonaro

    2013-01-01

    Full Text Available RNA processing involves a variety of processes affecting gene expression, including the removal of introns through RNA splicing, as well as 3' end processing (cleavage and polyadenylation. Alternative RNA processing is fundamentally important for gene regulation, and aberrant processing is associated with the initiation and progression of cancer. Deregulated Wnt signaling, which is the initiating event in the development of most cases of human colorectal cancer (CRC, has been linked to modified RNA processing, which may contribute to Wnt-mediated colonic carcinogenesis. Crosstalk between Wnt signaling and alternative RNA splicing with relevance to CRC includes effects on the expression of Rac1b, an alternatively spliced gene associated with tumorigenesis, which exhibits alternative RNA splicing that is influenced by Wnt activity. In addition, Tcf4, a crucial component of Wnt signaling, also exhibits alternative splicing, which is likely involved in colonic tumorigenesis. Modulation of 3' end formation, including of the Wnt target gene COX-2, also can influence the neoplastic process, with implications for CRC. While many human genes are dependent on introns and splicing for normal levels of gene expression, naturally intronless genes exist with a unique metabolism that allows for intron-independent gene expression. Effects of Wnt activity on the RNA metabolism of the intronless Wnt-target gene c-jun is a likely contributor to cancer development. Further, butyrate, a breakdown product of dietary fiber and a histone deacetylase inhibitor, upregulates Wnt activity in CRC cells, and also modulates RNA processing; therefore, the interplay between Wnt activity, the modulation of this activity by butyrate, and differential RNA metabolism in colonic cells can significantly influence tumorigenesis. Determining the role played by altered RNA processing in Wnt-mediated neoplasia may lead to novel interventions aimed at restoring normal RNA metabolism for

  2. The Experimental Analysis of Cross-talk Effect for Mixed-mode IC's Based on SOI Structure

    Institute of Scientific and Technical Information of China (English)

    ZHANGGuoyan; HUANGRu; ZHANGXing; WANGYangyuan

    2004-01-01

    The experimental study of cross-talk behavior is presented for mixed-mode integrated circuits based on SOI (Silicon-on-insulator) structure. Different strategies to reduce cross-talk are investigated. The influence of bulk contact, separation distance, the guard ring isolation and mesa isolation on the cross-talk has been compared. At the same time, the effect of load impedance on the cross-talk is also included. The results can serve as a guideline for designing low-noise coupling SOI mixed-mode IC's.

  3. Transcriptome-Wide Identification of Preferentially Expressed Genes in the Hypothalamus and Pituitary Gland

    OpenAIRE

    YuichiroNishida; JonnySt-Amand

    2012-01-01

    To identify preferentially expressed genes in the central endocrine organs of the hypothalamus and pituitary gland, we generated transcriptome-wide mRNA profiles of the hypothalamus, pituitary gland, and parietal cortex in male mice (12–15 weeks old) using serial analysis of gene expression (SAGE). Total counts of SAGE tags for the hypothalamus, pituitary gland, and parietal cortex were 165824, 126688, and 161045 tags, respectively. This represented 59244, 45151, and 55131 distinct tags, resp...

  4. Decreased hypothalamic growth hormone-releasing hormone content and pituitary responsiveness in hypothyroidism.

    OpenAIRE

    Katakami, H; Downs, T R; Frohman, L A

    1986-01-01

    The effects of thyroidectomy (Tx) and thyroxine replacement (T4Rx) on pituitary growth hormone (GH) secretion and hypothalamic GH-releasing hormone (GRH) concentration were compared to define the mechanism of hypothyroid-associated GH deficiency. Thyroidectomized rats exhibited a complete loss of pulsatile GH secretion with extensive reduction in GRH responsiveness and pituitary GH content. Cultured pituitary cells from Tx rats exhibited reduced GRH sensitivity, maximal GH responsiveness, and...

  5. STAT3 upregulation in pituitary somatotroph adenomas induces growth hormone hypersecretion

    OpenAIRE

    Zhou, Cuiqi; Jiao, Yonghui; Wang, Renzhi; Ren, Song-Guang; Wawrowsky, Kolja; Melmed, Shlomo

    2015-01-01

    Pituitary somatotroph adenomas result in dysregulated growth hormone (GH) hypersecretion and acromegaly; however, regulatory mechanisms that promote GH hypersecretion remain elusive. Here, we provide evidence that STAT3 directly induces somatotroph tumor cell GH. Evaluation of pituitary tumors revealed that STAT3 expression was enhanced in human GH-secreting adenomas compared with that in nonsecreting pituitary tumors. Moreover, STAT3 and GH expression were concordant in a somatotroph adenoma...

  6. The Spectrum of Hormone Immunoreactivity in Typical and Atypical Pituitary Adenomas

    Directory of Open Access Journals (Sweden)

    Yeşim ERTAN

    2009-09-01

    Full Text Available Objective: We aimed to assess the spectrum of hormone immunoreactivity in our pituitary adenoma cases and discuss the diagnostic parameters of atypical pituitary adenomas.Material and Methods: A total of 166 pituitary adenoma cases diagnosed from 2005 to 2008 in our department were included in the present study. Hematoxylin-eosin stained and immunohistochemistry performed slides (ACTH, PRL, GH, TSH, FSH, LH, Ki-67, and p53 were evaluated. Cases having more than two mitoses on 10 high power fields besides more than 3% Ki-67 index were accepted in the atypical group.Results: Histologically, 159 cases were typical pituitary adenoma and 7 were atypical pituitary adenoma. Of the atypical pituitary adenoma cases, one case was ACTH, one GH and one both GH and prolactin hormone immunoreactive pituitary adenomas. Four cases were hormone immunonegative adenomas. Of the typical pituitary adenoma cases, 39 cases were GH, 19 ACTH, 17 prolactin, 10 FSH, 8 LH and one TSH immunreactive pituitary adenomas. Fourty-seven cases were hormone immunonegative adenomas.Twenty-two of the all pitutary adenoma cases had recurrence. Of these cases, 18 were typical adenoma and four were atypical adenoma.Conclusion: The ratio of prolactin immunoreactive pituitary adenoma cases in the surgical material of neuropathology is decreasing due to medical therapy. Atypical pituitary adenomas are not the sole factor affecting the recurrence mechanism but these tumors have higher recurrence rate compared with typical pituitary adenomas and we think the proliferation index might be the principal approach in the diagnosis of these lesions.

  7. A Role for Glucocorticoids in Stress-Impaired Reproduction: Beyond the Hypothalamus and Pituitary

    OpenAIRE

    Whirledge, Shannon; Cidlowski, John A.

    2013-01-01

    In addition to the well-characterized role of the sex steroid receptors in regulating fertility and reproduction, reproductive events are also mediated by the hypothalamic-pituitary-adrenal axis in response to an individual's environment. Glucocorticoid secretion in response to stress contributes to the well-characterized suppression of the hypothalamic-pituitary-gonadal axis through central actions in the hypothalamus and pituitary. However, both animal and in vitro studies indicate that oth...

  8. Pituitary Insufficiency and Hyperprolactinemia Associated with Giant Intra- and Suprasellar Carotid Artery Aneurysm

    OpenAIRE

    Gungor, A.; Gokkaya, N.; Bilen, A.; H. Bilen; Akbas, E. M.; Y. Karadeniz; Eren, S

    2015-01-01

    Pituitary insufficiency secondary to internal carotid artery (ICA) aneurysm is a very rare condition. Its prevalence is reported as 0.17% (Heshmati et al., 2001). We present a case of pituitary insufficiency and hyperprolactinemia secondary to suprasellar giant intracranial aneurysm. A 71-year-old man was admitted to our clinic with symptoms of hypopituitarism, hyperprolactinemia, and visual field defect. His pituitary MRI and cerebral angiography revealed a giant saccular aneurysm filling su...

  9. Temozolomide (Temodar®) and capecitabine (Xeloda®) treatment of an aggressive corticotroph pituitary tumor

    OpenAIRE

    Thearle, Marie S.; Freda, Pamela U.; Bruce, Jeffrey N.; Isaacson, Steven R.; Lee, Yoomi; Fine, Robert L.

    2011-01-01

    Only rarely do corticotroph pituitary tumors become invasive leading to symptoms caused by compression of cranial nerves and other local structures. When aggressive pituitary neuroendocrine tumors do develop, conventional treatment options are of limited success. A 50-year-old man developed a giant invasive corticotroph pituitary tumor 2 years after initial presentation. His tumor and symptoms failed to respond to maximal surgical, radio-surgical, radiation and medical therapy and a bilateral...

  10. Cellular automata modelling of biomolecular networks dynamics.

    Science.gov (United States)

    Bonchev, D; Thomas, S; Apte, A; Kier, L B

    2010-01-01

    The modelling of biological systems dynamics is traditionally performed by ordinary differential equations (ODEs). When dealing with intracellular networks of genes, proteins and metabolites, however, this approach is hindered by network complexity and the lack of experimental kinetic parameters. This opened the field for other modelling techniques, such as cellular automata (CA) and agent-based modelling (ABM). This article reviews this emerging field of studies on network dynamics in molecular biology. The basics of the CA technique are discussed along with an extensive list of related software and websites. The application of CA to networks of biochemical reactions is exemplified in detail by the case studies of the mitogen-activated protein kinase (MAPK) signalling pathway, the FAS-ligand (FASL)-induced and Bcl-2-related apoptosis. The potential of the CA method to model basic pathways patterns, to identify ways to control pathway dynamics and to help in generating strategies to fight with cancer is demonstrated. The different line of CA applications presented includes the search for the best-performing network motifs, an analysis of importance for effective intracellular signalling and pathway cross-talk. PMID:20373215

  11. Protein kinase C (PKC) activity and PKC messenger RNAs in human pituitary adenomas.

    Science.gov (United States)

    Jin, L; Maeda, T; Chandler, W F; Lloyd, R V

    1993-02-01

    Protein kinase C (PKC) is involved in the differentiation and growth regulation of a variety of tissues including anterior pituitary gland cells. To determine the distribution of PKC in different types of adenomas, PKC activity was analyzed in human pituitary tumors and the effects of hypothalamic hormone stimulation on PKC activity were examined in cultured adenoma cells. Gonadotroph (LH/FSH) and null cell adenomas had significantly higher levels of particulate, soluble, and total PKC activity compared with growth hormone (GH) adenomas (P delta, epsilon, and zeta) were localized by in situ hybridization, normal and neoplastic pituitaries expressed abundant mRNA for PKC epsilon, whereas some tumors and one normal pituitary had a few cells positive for PKC zeta mRNA as evaluated by grain density and the number of cells labeled. These results indicate that there is a variable distribution of PKC mRNA isozymes in human pituitary adenomas and that normal pituitaries and pituitary adenoma cells express the mRNA for both the calcium-dependent and some of the calcium-independent PKC isozymes. Chronic treatment with the hypothalamic gonadotropin hormone-releasing hormone and GH-releasing hormone, which increased LH/FSH and GH secretion, respectively, did not increase PKC activity in cultured adenoma cells. The presence of calcium-dependent and calcium-independent PKC isozymes in normal and neoplastic pituitary cells indicates that PKC probably plays a major role in signal transduction in the human pituitary adenomas examined in this study. PMID:8434650

  12. IN VITRO CELL CULTURE AND HORMONE RADIOIMMUNOASSAY OF HUAMAN PITUITARY ADENOMAS

    Institute of Scientific and Technical Information of China (English)

    陆汉魁; 林祥通; 等

    1994-01-01

    Tissues from 30 human pituitary adenomas are monolayer-cell-cultured in vitro.Hormone secretion of GH,PRL,TSH,LH and FSH by cells into medium is detected by radioimmunoassay .The pattern and amount of hormone(s0 in the medium are used to determine the nature of the cells and thus to establish functional classification of pituitary adenomas.The results show that cell culture technique provides and easy and suitable mode for investigating the nature of pituitary adenomas.Hormone radioimmunoassay of culture medium is precise and reliable and represents the whole adenoma tissue.Further studies can lead to clearer understandngs of the pathology of pituitary adenomas.

  13. Pituitary gland levels of mercury, selenium, iron, and zinc in an Alzheimer`s disease study

    Energy Technology Data Exchange (ETDEWEB)

    Cornett, C.R.; Markesbery, W.R.; Wekstein, D.R.; Ehmann, W.D. [Univ. of Kentucky, Lexington, KY (United States)

    1996-12-31

    Mercury, iron, selenium, and zinc imbalances have been observed in comparisons between Alzheimer`s disease (AD) and control subject brains. Analyses of the pituitary gland have demonstrated that this organ retains relatively high concentrations of trace elements, including mercury, iron, and zinc. Our previous work has shown that the pituitary glands of AD and control subjects are typically higher in these trace elements than brain samples from the same subject. Instrumental neutron activation analysis (INAA) was used to compare the pituitary trace element levels of AD and control subjects. This study also describes the intrasubject relationships of brain trace element levels to those in the pituitary gland of AD and control subjects.

  14. Regulation of pituitary hormones and cell proliferation by components of the extracellular matrix

    Directory of Open Access Journals (Sweden)

    M. Paez-Pereda

    2005-10-01

    Full Text Available The extracellular matrix is a three-dimensional network of proteins, glycosaminoglycans and other macromolecules. It has a structural support function as well as a role in cell adhesion, migration, proliferation, differentiation, and survival. The extracellular matrix conveys signals through membrane receptors called integrins and plays an important role in pituitary physiology and tumorigenesis. There is a differential expression of extracellular matrix components and integrins during the pituitary development in the embryo and during tumorigenesis in the adult. Different extracellular matrix components regulate adrenocorticotropin at the level of the proopiomelanocortin gene transcription. The extracellular matrix also controls the proliferation of adrenocorticotropin-secreting tumor cells. On the other hand, laminin regulates the production of prolactin. Laminin has a dynamic pattern of expression during prolactinoma development with lower levels in the early pituitary hyperplasia and a strong reduction in fully grown prolactinomas. Therefore, the expression of extracellular matrix components plays a role in pituitary tumorigenesis. On the other hand, the remodeling of the extracellular matrix affects pituitary cell proliferation. Matrix metalloproteinase activity is very high in all types of human pituitary adenomas. Matrix metalloproteinase secreted by pituitary cells can release growth factors from the extracellular matrix that, in turn, control pituitary cell proliferation and hormone secretion. In summary, the differential expression of extracellular matrix components, integrins and matrix metalloproteinase contributes to the control of pituitary hormone production and cell proliferation during tumorigenesis.

  15. Hedgehog signaling activation induces stem cell proliferation and hormone release in the adult pituitary gland.

    Science.gov (United States)

    Pyczek, Joanna; Buslei, Rolf; Schult, David; Hölsken, Annett; Buchfelder, Michael; Heß, Ina; Hahn, Heidi; Uhmann, Anja

    2016-01-01

    Hedgehog (HH) signaling is known to be essential during the embryonal development of the pituitary gland but the knowledge about its role in the adult pituitary and in associated tumors is sparse. In this report we investigated the effect of excess Hh signaling activation in murine pituitary explants and analyzed the HH signaling status of human adenopituitary lobes and a large cohort of pituitary adenomas. Our data show that excess Hh signaling led to increased proliferation of Sox2(+) and Sox9(+) adult pituitary stem cells and to elevated expression levels of adrenocorticotropic hormone (Acth), growth hormone (Gh) and prolactin (Prl) in the adult gland. Inhibition of the pathway by cyclopamine reversed these effects indicating that active Hh signaling positively regulates proliferative processes of adult pituitary stem cells and hormone production in the anterior pituitary. Since hormone producing cells of the adenohypophysis as well as ACTH-, GH- and PRL-immunopositive adenomas express SHH and its target GLI1, we furthermore propose that excess HH signaling is involved in the development/maintenance of hormone-producing pituitary adenomas. These findings advance the understanding of physiological hormone regulation and may open new treatment options for pituitary tumors. PMID:27109116

  16. Diabetes Insipidus and Anterior Pituitary Insufficiency Due to Breast Cancer Metastasis

    Directory of Open Access Journals (Sweden)

    Ayşe Arduç

    2016-03-01

    Full Text Available Metastases from breast cancer to the pituitary gland are uncommon. We present a 35-year-old woman with diabetes insipidus and anterior pituitary insufficiency resulting from breast cancer metastases to the pituitary gland. The patient presented with reduced consciousness, fatigue, polyuria, and polydipsia. Hypernatremia (sodium: 154 mmol/L, hypostenuria (urine density: 1001, and hypopituitarism were present on laboratory evaluation. Magnetic resonance imaging (MRI revealed heterogeneous pituitary gland, thickened pituitary stalk (8mm, and loss of normal hyperintense signal of the posterior pituitary. Based on the clinical, laboratory, and MRI findings, the patient was diagnosed with diabetes insipidus and anterior pituitary insufficiency due to pituitary metastases from breast cancer. She received desmopressin, L-thyroxine, and prednisolone, which resulted in improvement of her symptoms and laboratory results. The patient, who also received Gamma Knife radiosurgery and chemotherapy, died six months later due to disseminated metastases. Although pituitary metastasis is rare, it should be kept in mind in patients with breast cancer since early detection and treatment can improve symptoms of patients.

  17. Pituitary Morphology and Function in 43 Children with Central Diabetes Insipidus

    Directory of Open Access Journals (Sweden)

    Wendong Liu

    2016-01-01

    Full Text Available Objective. In pediatric central diabetes insipidus (CDI, etiology diagnosis and pituitary function monitoring are usually delayed. This study aimed to illustrate the importance of regular follow-up and pituitary function monitoring in pediatric CDI. Methods. The clinical, hormonal, and neuroradiological characteristics of children with CDI at diagnosis and during 1.5–2-year follow-up were collected and analyzed. Results. The study included 43 CDI patients. The mean interval between initial manifestation and diagnosis was 22.29 ± 3.67 months (range: 2–108 months. The most common complaint was polyuria/polydipsia. Causes included Langerhans cell histiocytosis, germinoma, and craniopharyngioma in 2, 5, and 4 patients; the remaining were idiopathic. No significant changes were found during the 1.5–2 years after CDI diagnosis. Twenty-three of the 43 cases (53.5% had ≥1 anterior pituitary hormone deficiency. Isolated growth hormone deficiency was the most frequent abnormality (37.5% and was not associated with pituitary stalk diameter. Multiple pituitary hormone deficiencies were found in 8 cases with pituitary stalk diameter > 4.5 mm. Conclusion. Diagnosis of CDI is usually delayed. CDI with a pituitary stalk diameter > 4.5 mm carries a higher risk of multiple pituitary hormone deficiencies. Long-term MRI and pituitary function follow-ups are necessary for children with idiopathic CDI.

  18. Pituitary Morphology and Function in 43 Children with Central Diabetes Insipidus

    Science.gov (United States)

    Liu, Wendong; Wang, Limin; Liu, Minghua; Li, Guimei

    2016-01-01

    Objective. In pediatric central diabetes insipidus (CDI), etiology diagnosis and pituitary function monitoring are usually delayed. This study aimed to illustrate the importance of regular follow-up and pituitary function monitoring in pediatric CDI. Methods. The clinical, hormonal, and neuroradiological characteristics of children with CDI at diagnosis and during 1.5–2-year follow-up were collected and analyzed. Results. The study included 43 CDI patients. The mean interval between initial manifestation and diagnosis was 22.29 ± 3.67 months (range: 2–108 months). The most common complaint was polyuria/polydipsia. Causes included Langerhans cell histiocytosis, germinoma, and craniopharyngioma in 2, 5, and 4 patients; the remaining were idiopathic. No significant changes were found during the 1.5–2 years after CDI diagnosis. Twenty-three of the 43 cases (53.5%) had ≥1 anterior pituitary hormone deficiency. Isolated growth hormone deficiency was the most frequent abnormality (37.5%) and was not associated with pituitary stalk diameter. Multiple pituitary hormone deficiencies were found in 8 cases with pituitary stalk diameter > 4.5 mm. Conclusion. Diagnosis of CDI is usually delayed. CDI with a pituitary stalk diameter > 4.5 mm carries a higher risk of multiple pituitary hormone deficiencies. Long-term MRI and pituitary function follow-ups are necessary for children with idiopathic CDI. PMID:27118970

  19. A Case of Nonfunctioning Pituitary Carcinoma That Responded to Temozolomide Treatment

    Directory of Open Access Journals (Sweden)

    Haruko Morokuma

    2012-01-01

    Full Text Available Pituitary carcinoma is a rare malignancy and is difficult to manage. Pituitary carcinomas commonly produce either PRL or ACTH, but some do not produce pituitary hormones. The alkylating reagent temozolomide (TMZ was recently shown to be effective as a treatment for pituitary carcinoma. Most of the published reports of TMZ use in pituitary carcinoma cases were against hormone-producing carcinomas. Only a few patients with a nonfunctioning pituitary carcinoma treated with TMZ have been reported. Here we describe our treatment of a patient with nonfunctioning pituitary carcinoma and a background of multiple endocrine neoplasia type 1. The pituitary carcinoma was accompanied by meningeal dissemination with cerebral and L1 spinal bone metastasis. The patient received continuous dosing of TMZ along with external radiation, followed by standard dosing of TMZ. There was an apparent antitumor response seen in MRI. MGMT, an enzyme antagonized by TMZ, was negative in the tumor. The therapeutic efficacy of TMZ and dosing schedules of TMZ in pituitary carcinoma are discussed.

  20. Signal intensity of magnetic resonance imaging of pituitary adenoma reflects its collagen content

    Institute of Scientific and Technical Information of China (English)

    Hui Wang; Xianrui Yuan; Weixi Jiang

    2006-01-01

    BACKGROUND:At present,results of a few studies demonstrate that preoperative magnetic resonance imagling (MRI)examination reveals the texture of pituitary adenoma,I.e.on the T2-weighted image,solid pituitary adenoma shows weak signal and soft one shows strong signal.Also,solid pituitary adenoma is caused by fibrosis,which is confirmlea.However,some key problems are still in question and disputation,such as how to exactly quantize MRI signal intensity,which signal is used as prediction index,and the relationship of MRI signal and collagen content which reflects the texture of pituitary adenoma,and so on.OBJECTIVE:To observe the relationship of MRI signal intensity of different textures of pituitary adenoma and its collagen content,and investigate the best prediction index of the texture of pituitary adenoma.DESIGN:Case-control observation.SETTING:Department of Neurosurgery,Third Hospital Affiliated to Sun Yat-sen University;Department of Neurosurgery,Xiangya Hospital,Central South University.PARTICIPANTS:Fifty-seven patients with pituitary adenoma,including 32 males and 25 females,aged 20 to 65 years,who received treatment in the Department of Neurosurgery,Xiangya Hospital,Central South University during June 2003 to January 2004.The involved patients were all diagnosed by MRI and confirmed by pathological resection.Informed consents were obtained from all the patients.The samples of above-mentioned patients resected by operation were fixed with 40 g/L formaldehyde for sirius red staining.METHODS:①Accordling to the texture of pituitary adenoma observed in the operation:The 57 samples of pituitary adenoma were divided into 2 groups:non-flbrosis group(n=49)and fibrosis group(n=8).In the non-fibrosis group,the texture of pituitary adenoma was soft,I.e.pituitary adenoma tissue automatically flew out,and could be aspirated by aspirater or erased by curette,and the superior part of saddle could fall in the saddle,In the fibrosis group,pituitary adenoma tissue could be

  1. Measurements and analysis of optical crosstalk in a microwave kinetic inductance detector array

    CERN Document Server

    Bisigello, L; Ferrari, L; Baselmans, J J A; Baryshev, A M

    2016-01-01

    The main advantage of Microwave Kinetic Inductance Detector arrays (MKID) is their multiplexing capability, which allows for building cameras with a large number of pixels and good sensitivity, particularly suitable to perform large blank galaxy surveys. However, to have as many pixels as possible it is necessary to arrange detectors close in readout frequency. Consequently KIDs overlap in frequency and are coupled to each other producing crosstalk. Because crosstalk can be only minimised by improving the array design, in this work we aim to correct for this effect a posteriori. We analysed a MKID array consisting of 880 KIDs with readout frequencies at 4-8 GHz. We measured the beam patterns for every detector in the array and described the response of each detector by using a two-dimensional Gaussian fit. Then, we identified detectors affected by crosstalk above -30 dB level from the maximum and removed the signal of the crosstalking detectors. Moreover, we modelled the crosstalk level for each KID as a func...

  2. Comparative Study of Crosstalk Reduction Techniques in RF Printed Circuit Board Using FDTD Method

    Directory of Open Access Journals (Sweden)

    Rajeswari Packianathan

    2015-01-01

    Full Text Available Miniaturization of the feature size in modern electronic circuits results from placing interconnections in close proximity with a high packing density. As a result, coupling between the adjacent lines has increased significantly, causing crosstalk to become an important concern in high-performance circuit design. In certain applications, microstriplines may be used in printed circuit boards for propagating high-speed signals, rather than striplines. Here, the electromagnetic coupling effects are analyzed for various microstrip transmission line structures, namely, microstriplines with a guard trace, double stub microstriplines, and parallel serpentine microstriplines using the finite-difference time-domain method. The numerical results are compared with simulation results, where the variants are simulated using an Ansoft high-frequency structure simulator. The analysis and simulation results are experimentally validated by fabricating a prototype and establishing a good correspondence between them. Numerical results are compared with simulation and experimental results, showing that double stub microstriplines reduce the far end crosstalk by 7 dB and increase the near end crosstalk by about 2 dB compared with the parallel microstriplines. Parallel serpentine microstriplines reduce the far end crosstalk by more than 10 dB and also reduce more than 15 mV of peak far end crosstalk voltage, compared with parallel microstriplines.

  3. Orbital angular momentum crosstalk of single photons propagation in a slant non-Kolmogorov turbulence channel

    Science.gov (United States)

    Zhang, Yi-xin; Wang, Yang-guang; Xu, Jian-cai; Wang, Jian-yu; Jia, Jian-jun

    2011-03-01

    We analyze the orbital angular momentum (OAM) crosstalk of single photons propagation through low-order atmospheric turbulence. The probability models of the orbital angular momentum crosstalk for single photons propagation in the channel with the non-Kolmogorov turbulence tilt, coma, and astigmatism and defocus aberration have been established. It is found, for α = 11/3, that the turbulent tilt is the dominant aberration which causes the orbital angular momentum crosstalk, the coma is second and the astigmatism is third, but the defocus aberration has no impact on OAM. The results also indicate that the regularities of orbital angular momentum crosstalk caused by the tilt, the coma and the astigmatism are almost the same, respectively. The crosstalk probability of the orbital angular momentum increases as the azimuth mode index p of Laguerre-Gaussian (LG) beam increases, the turbulent strength Cn2 enhances, the orbital angular momentum quantum number rises, the diameter of circular sampling aperture D and the channel zenith angle θ increase.

  4. Influence of force-based crosstalk on the 'wedge method' in lateral force microscopy

    International Nuclear Information System (INIS)

    The lateral force mode of an atomic force microscope is a contact-based measurement where the cantilever moves laterally in order to contribute to the lateral component of the tip–surface interaction. An accurate quantitative measure is difficult to achieve and is subject to the calibration of a model of the machine such that the output signal is related to the contact forces. Currently available models and calibration methods do not consider the existence of crosstalk. The influence of the latter on the measurement is not clearly identified and raises the question of the result's accuracy. In this paper a definition of the crosstalk is given and the diversity of the crosstalk briefly presented. A first-order, two-dimensional model of the system that includes the force-based crosstalk is presented. The model is used to simulate a calibration method known as the 'wedge method'. A parametric study is carried out to evaluate the calibration errors that can be made by the 'wedge method'. Results show that force-based crosstalk can have a noticeable influence on the calibration as well as on the estimated friction coefficient

  5. Spatial optical crosstalk in CMOS image sensors integrated with plasmonic color filters.

    Science.gov (United States)

    Yu, Yan; Chen, Qin; Wen, Long; Hu, Xin; Zhang, Hui-Fang

    2015-08-24

    Imaging resolution of complementary metal oxide semiconductor (CMOS) image sensor (CIS) keeps increasing to approximately 7k × 4k. As a result, the pixel size shrinks down to sub-2μm, which greatly increases the spatial optical crosstalk. Recently, plasmonic color filter was proposed as an alternative to conventional colorant pigmented ones. However, there is little work on its size effect and the spatial optical crosstalk in a model of CIS. By numerical simulation, we investigate the size effect of nanocross array plasmonic color filters and analyze the spatial optical crosstalk of each pixel in a Bayer array of a CIS with a pixel size of 1μm. It is found that the small pixel size deteriorates the filtering performance of nanocross color filters and induces substantial spatial color crosstalk. By integrating the plasmonic filters in the low Metal layer in standard CMOS process, the crosstalk reduces significantly, which is compatible to pigmented filters in a state-of-the-art backside illumination CIS. PMID:26368174

  6. Crosstalk elimination in the detection of dual-beam optical tweezers by spatial filtering

    Energy Technology Data Exchange (ETDEWEB)

    Ott, Dino; Oddershede, Lene B., E-mail: oddershede@nbi.dk [Niels Bohr Institute (NBI), University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen (Denmark); Reihani, S. Nader S. [Department of Physics, Sharif University of Technology, 11369-9161 Tehran (Iran, Islamic Republic of)

    2014-05-15

    In dual-beam optical tweezers, the accuracy of position and force measurements is often compromised by crosstalk between the two detected signals, this crosstalk leading to systematic and significant errors on the measured forces and distances. This is true both for dual-beam optical traps where the splitting of the two traps is done by polarization optics and for dual optical traps constructed by other methods, e.g., holographic tweezers. If the two traps are orthogonally polarized, most often crosstalk is minimized by inserting polarization optics in front of the detector; however, this method is not perfect because of the de-polarization of the trapping beam introduced by the required high numerical aperture optics. Here we present a simple and easy-to-implement method to efficiently eliminate crosstalk. The method is based on spatial filtering by simply inserting a pinhole at the correct position and is highly compatible with standard back focal plane photodiode based detection of position and force. Our spatial filtering method reduces crosstalk up to five times better than polarization filtering alone. The effectiveness is dependent on pinhole size and distance between the traps and is here quantified experimentally and reproduced by theoretical modeling. The method here proposed will improve the accuracy of force-distance measurements, e.g., of single molecules, performed by dual-beam optical traps and hence give much more scientific value for the experimental efforts.

  7. Crosstalk elimination in the detection of dual-beam optical tweezers by spatial filtering

    Science.gov (United States)

    Ott, Dino; Reihani, S. Nader S.; Oddershede, Lene B.

    2014-05-01

    In dual-beam optical tweezers, the accuracy of position and force measurements is often compromised by crosstalk between the two detected signals, this crosstalk leading to systematic and significant errors on the measured forces and distances. This is true both for dual-beam optical traps where the splitting of the two traps is done by polarization optics and for dual optical traps constructed by other methods, e.g., holographic tweezers. If the two traps are orthogonally polarized, most often crosstalk is minimized by inserting polarization optics in front of the detector; however, this method is not perfect because of the de-polarization of the trapping beam introduced by the required high numerical aperture optics. Here we present a simple and easy-to-implement method to efficiently eliminate crosstalk. The method is based on spatial filtering by simply inserting a pinhole at the correct position and is highly compatible with standard back focal plane photodiode based detection of position and force. Our spatial filtering method reduces crosstalk up to five times better than polarization filtering alone. The effectiveness is dependent on pinhole size and distance between the traps and is here quantified experimentally and reproduced by theoretical modeling. The method here proposed will improve the accuracy of force-distance measurements, e.g., of single molecules, performed by dual-beam optical traps and hence give much more scientific value for the experimental efforts.

  8. Heterogeneous cellular networks

    CERN Document Server

    Hu, Rose Qingyang

    2013-01-01

    A timely publication providing coverage of radio resource management, mobility management and standardization in heterogeneous cellular networks The topic of heterogeneous cellular networks has gained momentum in industry and the research community, attracting the attention of standardization bodies such as 3GPP LTE and IEEE 802.16j, whose objectives are looking into increasing the capacity and coverage of the cellular networks. This book focuses on recent progresses,  covering the related topics including scenarios of heterogeneous network deployment, interference management i

  9. Cellular Reflectarray Antenna

    Science.gov (United States)

    Romanofsky, Robert R.

    2010-01-01

    The cellular reflectarray antenna is intended to replace conventional parabolic reflectors that must be physically aligned with a particular satellite in geostationary orbit. These arrays are designed for specified geographical locations, defined by latitude and longitude, each called a "cell." A particular cell occupies nominally 1,500 square miles (3,885 sq. km), but this varies according to latitude and longitude. The cellular reflectarray antenna designed for a particular cell is simply positioned to align with magnetic North, and the antenna surface is level (parallel to the ground). A given cellular reflectarray antenna will not operate in any other cell.

  10. Nuclear magnetic resonance studies of biological systems: Applications to liver preservation and metabolism in cultured pituitary tumor cells

    International Nuclear Information System (INIS)

    This study centers on applications of both 31P and 13C nuclear magnetic resonance spectroscopy to two different biological systems. The first application utilizes 31P NMR to study mobile phospholipids in the MMQ cell line, a pituitary tumor cell line. These measurements characterize membrane phospholipids thought to be part of a RNA-proteolipid complex unique to cellular transformation. The second application utilizes both 31P and 13C spectroscopy to study liver preservation and transplantation an a rat model. In this work, several questions were addressed: (1) to what extent do successful preservation solutions slow ATP breakdown? (2) can clinically successful preservation conditions ameliorate total nucleotide breakdown? (3) to what extent is energy reconstitution following cold storage correlated with transport success? and (4) can any spectroscopic parameter be used as a diagnostic indicator of tissue viability?

  11. Fathead minnow steroidogenesis: in silico analyses reveals tradeoffs between nominal target efficacy and robustness to cross-talk

    Directory of Open Access Journals (Sweden)

    Villeneuve Daniel L

    2010-06-01

    Full Text Available Abstract Background Interpreting proteomic and genomic data is a major challenge in predictive ecotoxicology that can be addressed by a systems biology approach. Mathematical modeling provides an organizational platform to consolidate protein dynamics with possible genomic regulation. Here, a model of ovarian steroidogenesis in the fathead minnow, Pimephales promelas, (FHM is developed to evaluate possible transcriptional regulation of steroid production observed in microarray studies. Results The model was developed from literature sources, integrating key signaling components (G-protein and PKA activation with their ensuing effect on steroid production. The model properly predicted trajectory behavior of estradiol and testosterone when fish were exposed to fadrozole, a specific aromatase inhibitor, but failed to predict the steroid hormone behavior occurring one week post-exposure as well as the increase in steroid levels when the stressor was removed. In vivo microarray data implicated three modes of regulation which may account for over-production of steroids during a depuration phase (when the stressor is removed: P450 enzyme up-regulation, inhibin down-regulation, and luteinizing hormone receptor up-regulation. Simulation studies and sensitivity analysis were used to evaluate each case as possible source of compensation to endocrine stress. Conclusions Simulation studies of the testosterone and estradiol response to regulation observed in microarray data supported the hypothesis that the FHM steroidogenesis network compensated for endocrine stress by modulating the sensitivity of the ovarian network to global cues coming from the hypothalamus and pituitary. Model predictions of luteinizing hormone receptor regulation were consistent with depuration and in vitro data. These results challenge the traditional approach to network elucidation in systems biology. Generally, the most sensitive interactions in a network are targeted for further

  12. Cellular oncogenes in neoplasia.

    OpenAIRE

    Chan, V T; McGee, J O

    1987-01-01

    In recent years cellular homologues of many viral oncogenes have been identified. As these genes are partially homologous to viral oncogenes and are activated in some tumour cell lines they are termed "proto-oncogenes". In tumour cell lines proto-oncogenes are activated by either quantitative or qualitative changes in gene structure: activation of these genes was originally thought to be a necessary primary event in carcinogenesis, but activated cellular oncogenes, unlike viral oncogenes, do ...

  13. Cellular Cardiomyoplasty: Clinical Application

    OpenAIRE

    Chachques, J. (J.); Acar, C; J. Herreros; Trainini, J. (Jorge); Prosper, F.; D’Attellis, N. (N.); Fabiani, J. N.; Carpentier, A

    2004-01-01

    Myocardial regeneration can be induced with the implantation of a variety of myogenic and angiogenic cell types. More than 150 patients have been treated with cellular cardiomyoplasty worldwide, 18 patients have been treated by our group. Cellular cardiomyoplasty seems to reduce the size and fibrosis of infarct scars, limit postischemic remodelling, and restore regional myocardial contractility. Techniques for skeletal myoblasts culture and ex vivo expansion using auto...

  14. Crosstalk Between Reverse Cholesterol Transport and Innate Immunity

    OpenAIRE

    Azzam, Kathleen M.; Fessler, Michael B.

    2012-01-01

    Although lipid metabolism and host defense are widely considered to be very divergent disciplines, compelling evidence suggests that host cell handling of self- and microbe-derived (e.g., lipopolysaccharide) lipids may have common evolutionary roots, and that they indeed may be inseparable processes. The innate immune response and the homeostatic network controlling cellular sterol levels are now known to reciprocally regulate one another, with important implications for several common diseas...

  15. Analysis of regulatory networks constructed based on gene coexpression in pituitary adenoma

    Indian Academy of Sciences (India)

    Jie Gong; Bo Diao; Guo Jie Yao; Ying Liu; Guo Zheng Xu

    2013-12-01

    Gene coexpression patterns can reveal gene collections with functional consistency. This study systematically constructs regulatory networks for pituitary tumours by integrating gene coexpression, transcriptional and posttranscriptional regulation. Through network analysis, we elaborate the incidence mechanism of pituitary adenoma. The Pearson’s correlation coefficient was utilized to calculate the level of gene coexpression. By comparing pituitary adenoma samples with normal samples, pituitary adenoma-specific gene coexpression patterns were identified. For pituitary adenoma-specific coexpressed genes, we integrated transcription factor (TF) and microRNA (miRNA) regulation to construct a complex regulatory network from the transcriptional and posttranscriptional perspectives. Network module analysis identified the synergistic regulation of genes by miRNAs and TFs in pituitary adenoma. We identified 142 pituitary adenoma-specific active genes, including 43 TFs and 99 target genes of TFs. Functional enrichment of these 142 genes revealed that the occurrence of pituitary adenoma induced abnormalities in intracellular metabolism and angiogenesis process. These 142 genes were also significantly enriched in adenoma pathway. Module analysis of the systematic regulatory network found that three modules contained elements that were closely related to pituitary adenoma, such as FGF2 and SP1, as well as transcription factors and miRNAs involved in the tumourigenesis. These results show that in the occurrence of pituitary adenoma, miRNA, TF and genes interact with each other. Based on gene expression, the proposed method integrates interaction information from different levels and systematically explains the occurrence of pituitary tumours. It facilitates the tracing of the origin of the disease and can provide basis for early diagnosis of complex diseases or cancer without obvious symptoms.

  16. A CMOS-compatible silicon substrate optimization technique and its application in radio frequency crosstalk isolation

    International Nuclear Information System (INIS)

    In this paper, a complementary metal-oxide semiconductor (CMOS)-compatible silicon substrate optimization technique is proposed to achieve effective isolation. The selective growth of porous silicon is used to effectively suppress the substrate crosstalk. The isolation structures are fabricated in standard CMOS process and then this post-CMOS substrate optimization technique is carried out to greatly improve the performances of crosstalk isolation. Three-dimensional electro-magnetic simulation is implemented to verify the obvious effect of our substrate optimization technique. The morphologies and growth condition of porous silicon fabricated have been investigated in detail. Furthermore, a thick selectively grown porous silicon (SGPS) trench for crosstalk isolation has been formed and about 20dB improvement in substrate isolation is achieved. These results demonstrate that our post-CMOS SGPS technique is very promising for RF IC applications. (cross-disciplinary physics and related areas of science and technology)

  17. Readout cross-talk for alpha-particle measurements in a pixelated sensor system

    International Nuclear Information System (INIS)

    Simulations in Medici are performed to quantify crosstalk and charge sharing in a hybrid pixelated silicon detector. Crosstalk and charge sharing degrades the spatial and spectral resolution of single photon processing X-ray imaging systems. For typical medical X-ray imaging applications, the process is dominated by charge sharing between the pixels in the sensor. For heavier particles each impact generates a large amount of charge and the simulation seems to over predict the charge collection efficiency. This indicates that some type of non modelled degradation of the charge transport efficiency exists, like the plasma effect where the plasma might shield the generated charges from the electric field and hence distorts the charge transport process. Based on the simulations it can be reasoned that saturation of the amplifiers in the Timepix system might generate crosstalk that increases the charge spread measured from ion impact on the sensor

  18. Readout cross-talk for alpha-particle measurements in a pixelated sensor system

    Science.gov (United States)

    Norlin, B.; Reza, S.; Krapohl, D.; Fröjdh, E.; Thungström, G.

    2015-05-01

    Simulations in Medici are performed to quantify crosstalk and charge sharing in a hybrid pixelated silicon detector. Crosstalk and charge sharing degrades the spatial and spectral resolution of single photon processing X-ray imaging systems. For typical medical X-ray imaging applications, the process is dominated by charge sharing between the pixels in the sensor. For heavier particles each impact generates a large amount of charge and the simulation seems to over predict the charge collection efficiency. This indicates that some type of non modelled degradation of the charge transport efficiency exists, like the plasma effect where the plasma might shield the generated charges from the electric field and hence distorts the charge transport process. Based on the simulations it can be reasoned that saturation of the amplifiers in the Timepix system might generate crosstalk that increases the charge spread measured from ion impact on the sensor.

  19. Crosstalk, cathode structure and electrical parameters of the MWPCs for the LHCb muon system

    CERN Document Server

    Riegler, W

    2000-01-01

    This note discusses the electrical characteristics of the Multi Wire Proportional Chambers (MWPCs) for the LHCb muon system that were originally developed at PNPI. Optimized layouts for cathode structure and readout traces together with the expected crosstalk numbers are presented. We conclude that cathode pad dimensions should not be smaller than 3 cm in order to limit the cluster size to smaller than 1.2. We also conclude that a front-end electronics input resistance of less than 50 Ohm is preferred in order to limit the capacitive crosstalk. In some regions a resistance of 100 Ohm might be acceptable. In order to limit the crosstalk for chambers with a 'chessboard' cathode structure it is essential that we run the signal traces parallel to the wires.

  20. Directional gamma sensing from covariance processing of inter-detector Compton crosstalk energy asymmetries

    Energy Technology Data Exchange (ETDEWEB)

    Trainham, R., E-mail: trainhcp@nv.doe.gov; Tinsley, J. [Special Technologies Laboratory of National Security Technologies, LLC, 5520 Ekwill Street, Santa Barbara, California 93111 (United States)

    2014-06-15

    Energy asymmetry of inter-detector crosstalk from Compton scattering can be exploited to infer the direction to a gamma source. A covariance approach extracts the correlated crosstalk from data streams to estimate matched signals from Compton gammas split over two detectors. On a covariance map the signal appears as an asymmetric cross diagonal band with axes intercepts at the full photo-peak energy of the original gamma. The asymmetry of the crosstalk band can be processed to determine the direction to the radiation source. The technique does not require detector shadowing, masking, or coded apertures, thus sensitivity is not sacrificed to obtain the directional information. An angular precision of better than 1° of arc is possible, and processing of data streams can be done in real time with very modest computing hardware.

  1. Directional gamma sensing from covariance processing of inter-detector Compton crosstalk energy asymmetries

    Science.gov (United States)

    Trainham, R.; Tinsley, J.

    2014-06-01

    Energy asymmetry of inter-detector crosstalk from Compton scattering can be exploited to infer the direction to a gamma source. A covariance approach extracts the correlated crosstalk from data streams to estimate matched signals from Compton gammas split over two detectors. On a covariance map the signal appears as an asymmetric cross diagonal band with axes intercepts at the full photo-peak energy of the original gamma. The asymmetry of the crosstalk band can be processed to determine the direction to the radiation source. The technique does not require detector shadowing, masking, or coded apertures, thus sensitivity is not sacrificed to obtain the directional information. An angular precision of better than 1° of arc is possible, and processing of data streams can be done in real time with very modest computing hardware.

  2. Amplitude-phase cross-talk cancellation in frequency domain instrumentation

    Science.gov (United States)

    Morgan, Stephen P.; Yong, Kai Y.

    2001-06-01

    Changes in phase that occurs with changes in amplitude impose severe limitations on the accuracy of frequency domain near infrared spectrometers. Phase is related to the photon pathlength in tissue and phase errors introduced by the instrument can be interpreted as changes in tissue oxygenation. The instrument described employs a reference RF modulated laser diode to eliminate the effects of amplitude- phase crosstalk and requires no feedback. Light from the reference and medium channels follow a common path through the detector and so the same phase error is imposed on both. Summing the reference and medium phase eliminates the crosstalk and enables the resultant to be attributed only to photon pathlength within the medium. It is also demonstrated that elimination of amplitude-phase crosstalk is a natural consequence of a phased array configuration.

  3. Elimination of amplitude-phase crosstalk in frequency domain near-infrared spectroscopy

    Science.gov (United States)

    Morgan, S. P.; Yong, K. Y.

    2001-04-01

    Changes in phase that occur with changes in amplitude impose severe limitations on the accuracy of frequency domain near-infrared spectrometers. Phase is related to the photon pathlength in tissue and phase errors introduced by the instrument can be interpreted as changes in tissue oxygenation. The instrument described in this article employs a reference radio frequency modulated laser diode to eliminate the effects of amplitude-phase crosstalk and requires no feedback. Light from the reference laser diode does not pass through the medium under investigation but passes directly onto the detector. The reference and medium signals follow a common path through the detector and so the same phase error is imposed on both. Summing the reference and medium phase eliminates the crosstalk and enables the resultant to be attributed only to the photon pathlength within the medium. It is also demonstrated that elimination of amplitude-phase crosstalk is a natural consequence of a phased array configuration.

  4. A Novel Crosstalk Suppression Method of the 2-D Networked Resistive Sensor Array

    Directory of Open Access Journals (Sweden)

    Jianfeng Wu

    2014-07-01

    Full Text Available The 2-D resistive sensor array in the row–column fashion suffered from the crosstalk problem for parasitic parallel paths. Firstly, we proposed an Improved Isolated Drive Feedback Circuit with Compensation (IIDFCC based on the voltage feedback method to suppress the crosstalk. In this method, a compensated resistor was specially used to reduce the crosstalk caused by the column multiplexer resistors and the adjacent row elements. Then, a mathematical equivalent resistance expression of the element being tested (EBT of this circuit was analytically derived and verified by the circuit simulations. The simulation results show that the measurement method can greatly reduce the influence on the EBT caused by parasitic parallel paths for the multiplexers’ channel resistor and the adjacent elements.

  5. Digital Image Diffusion Technique for Suppressing Interpage Crosstalk in Holographic Data Storage

    Science.gov (United States)

    Shibukawa, Atsushi; Okamoto, Atsushi; Wakayama, Yuta; Tomita, Akihisa; Funakoshi, Hisatoshi; Sato, Kunihiro

    2013-09-01

    To suppress interpage crosstalk that strongly restricts holographic data storage capacity, a digital image diffusion technique was proposed. In this technique, signal and crosstalk components are separated from the propagation angle difference produced by using a random diffuser and the nature of phase conjugate lights. The most attractive feature of the technique is that crosstalk suppression can be conducted while mostly keeping the conventional holographic data storage system unchanged by integrating optical processing and digital processing effectively. The connection between the two types of processing is realized by using two spatial light modulators for complex amplitude generation and phase detection methods for complex amplitude measurement. The simulation results showed that the proposed technique could increase the recording density 5.5-fold and reduce the shift pitch by a factor of 5 in comparison with conventional multiplexing methods when the diffusion angle of the diffuser is 10°.

  6. Correcting for color crosstalk and chromatic aberration in multicolor particle shadow velocimetry

    International Nuclear Information System (INIS)

    Color crosstalk and chromatic aberration can bias estimates of fluid velocity measured by color particle shadow velocimetry (CPSV), using multicolor illumination and a color camera. This article describes corrections to remove these bias errors, and their evaluation. Color crosstalk removal is demonstrated with linear unmixing. It is also shown that chromatic aberrations may be removed using either scale calibration, or by processing an image illuminated by all colors simultaneously. CPSV measurements of a fully developed turbulent pipe flow of glycerin were conducted. Corrected velocity statistics from these measurements were compared to both single-color PSV and LDV measurements and showed excellent agreement to fourth-order, to well into the viscous sublayer. Recommendations for practical assessment and correction of color aberration and color crosstalk are discussed. (paper)

  7. Polyamine and methionine adenosyltransferase 2A crosstalk in human colon and liver cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tomasi, Maria Lauda [Division of Gastrointestinal and Liver Diseases, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033 (United States); USC Research Center for Liver Diseases, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033 (United States); The Southern California Research Center for Alcoholic and Pancreatic Diseases and Cirrhosis, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033 (United States); Ryoo, Minjung; Skay, Anna [Division of Gastrointestinal and Liver Diseases, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033 (United States); USC Research Center for Liver Diseases, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033 (United States); Tomasi, Ivan; Giordano, Pasquale [Department of Colorectal Surgery, Whipps Cross University Hospital, London E11 1NR (United Kingdom); Mato, José M. [CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Technology Park of Bizkaia, 48160 Derio, Bizkaia (Spain); Lu, Shelly C., E-mail: shellylu@usc.edu [Division of Gastrointestinal and Liver Diseases, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033 (United States); USC Research Center for Liver Diseases, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033 (United States); The Southern California Research Center for Alcoholic and Pancreatic Diseases and Cirrhosis, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033 (United States)

    2013-07-15

    Methionine adenosyltransferase (MAT) is an essential enzyme that is responsible for the biosynthesis of S-adenosylmethionine (SAMe), the principal methyl donor and precursor of polyamines. MAT1A is expressed in normal liver and MAT2A is expressed in all extrahepatic tissues. MAT2A expression is increased in human colon cancer and in colon cancer cells treated with mitogens, whereas silencing MAT2A resulted in apoptosis. The aim of the current work was to examine the mechanism responsible for MAT2A-dependent growth and apoptosis. We found that in RKO (human adenocarcinoma cell line) cells, MAT2A siRNA treatment lowered cellular SAMe and putrescine levels by 70–75%, increased apoptosis and inhibited growth. Putrescine supplementation blunted significantly MAT2A siRNA-induced apoptosis and growth suppression. Putrescine treatment (100 pmol/L) raised MAT2A mRNA level to 4.3-fold of control, increased the expression of c-Jun and c-Fos and binding to an AP-1 site in the human MAT2A promoter and the promoter activity. In human colon cancer specimens, the expression levels of MAT2A, ornithine decarboxylase (ODC), c-Jun and c-Fos are all elevated as compared to adjacent non-tumorous tissues. Overexpression of ODC in RKO cells also raised MAT2A mRNA level and MAT2A promoter activity. ODC and MAT2A are also overexpressed in liver cancer and consistently, similar MAT2A-ODC-putrescine interactions and effects on growth and apoptosis were observed in HepG2 cells. In conclusion, there is a crosstalk between polyamines and MAT2A. Increased MAT2A expression provides more SAMe for polyamines biosynthesis; increased polyamine (putrescine in this case) can activate MAT2A at the transcriptional level. This along with increased ODC expression in cancer all feed forward to further enhance the proliferative capacity of the cancer cell. -- Highlights: • MAT2A knockdown depletes putrescine and leads to apoptosis. • Putrescine attenuates MAT2A knockdown-induced apoptosis and growth

  8. Polyamine and methionine adenosyltransferase 2A crosstalk in human colon and liver cancer

    International Nuclear Information System (INIS)

    Methionine adenosyltransferase (MAT) is an essential enzyme that is responsible for the biosynthesis of S-adenosylmethionine (SAMe), the principal methyl donor and precursor of polyamines. MAT1A is expressed in normal liver and MAT2A is expressed in all extrahepatic tissues. MAT2A expression is increased in human colon cancer and in colon cancer cells treated with mitogens, whereas silencing MAT2A resulted in apoptosis. The aim of the current work was to examine the mechanism responsible for MAT2A-dependent growth and apoptosis. We found that in RKO (human adenocarcinoma cell line) cells, MAT2A siRNA treatment lowered cellular SAMe and putrescine levels by 70–75%, increased apoptosis and inhibited growth. Putrescine supplementation blunted significantly MAT2A siRNA-induced apoptosis and growth suppression. Putrescine treatment (100 pmol/L) raised MAT2A mRNA level to 4.3-fold of control, increased the expression of c-Jun and c-Fos and binding to an AP-1 site in the human MAT2A promoter and the promoter activity. In human colon cancer specimens, the expression levels of MAT2A, ornithine decarboxylase (ODC), c-Jun and c-Fos are all elevated as compared to adjacent non-tumorous tissues. Overexpression of ODC in RKO cells also raised MAT2A mRNA level and MAT2A promoter activity. ODC and MAT2A are also overexpressed in liver cancer and consistently, similar MAT2A-ODC-putrescine interactions and effects on growth and apoptosis were observed in HepG2 cells. In conclusion, there is a crosstalk between polyamines and MAT2A. Increased MAT2A expression provides more SAMe for polyamines biosynthesis; increased polyamine (putrescine in this case) can activate MAT2A at the transcriptional level. This along with increased ODC expression in cancer all feed forward to further enhance the proliferative capacity of the cancer cell. -- Highlights: • MAT2A knockdown depletes putrescine and leads to apoptosis. • Putrescine attenuates MAT2A knockdown-induced apoptosis and growth

  9. Cross-talk and information transfer in mammalian and bacterial signaling.

    Directory of Open Access Journals (Sweden)

    Samanthe M Lyons

    Full Text Available In mammalian and bacterial cells simple phosphorylation circuits play an important role in signaling. Bacteria have hundreds of two-component signaling systems that involve phosphotransfer between a receptor and a response regulator. In mammalian cells a similar pathway is the TGF-beta pathway, where extracellular TGF-beta ligands activate cell surface receptors that phosphorylate Smad proteins, which in turn activate many genes. In TGF-beta signaling the multiplicity of ligands begs the question as to whether cells can distinguish signals coming from different ligands, but transduced through a small set of Smads. Here we use information theory with stochastic simulations of networks to address this question. We find that when signals are transduced through only one Smad, the cell cannot distinguish between different levels of the external ligands. Increasing the number of Smads from one to two significantly improves information transmission as well as the ability to discriminate between ligands. Surprisingly, both total information transmitted and the capacity to discriminate between ligands are quite insensitive to high levels of cross-talk between the two Smads. Robustness against cross-talk requires that the average amplitude of the signals are large. We find that smaller systems, as exemplified by some two-component systems in bacteria, are significantly much less robust against cross-talk. For such system sizes phosphotransfer is also less robust against cross-talk than phosphorylation. This suggests that mammalian signal transduction can tolerate a high amount of cross-talk without degrading information content. This may have played a role in the evolution of new functionalities from small mutations in signaling pathways, allowed for the development of cross-regulation and led to increased overall robustness due to redundancy in signaling pathways. On the other hand the lack of cross-regulation observed in many bacterial two

  10. Optical crosstalk in CT detectors and its effects on CT images

    Science.gov (United States)

    Youn, Hanbean; Kam, Soohwa; Han, Jong Chul; Kim, Ho Kyung

    2014-03-01

    Detectors for computed tomography (CT) typically consist of scintillator and photodiode arrays which are coupled using optical glue. Therefore, the leakage of optical photons generated in a scintillator block to neighboring pixel photodiodes through the optical glue layer is inevitable. Passivation layers to protect the silicon photodiode as well as the silicon layer itself, which is inactive to the optical photons, are another causes for the leakage. This optical crosstalk reduces image sharpness, and eventually will blur CT images. We have quantitatively investigated the optical crosstalk in CT detectors using the Monte Carlo technique. We performed the optical Monte Carlo simulations for various thicknesses of optical components in a 129 × 129 CT detector array. We obtained the coordinates of optical photons hitting the user-defined detection plane. From the coordinate information, we calculated the collection efficiency at the detection plane and the collection efficiency at the single pixel located just below the scintillator in which the optical photons were generated. Difference between the two quantities provided the optical crosstalk. In addition, using the coordinate information, we calculated point-spread functions as well as modulation-transfer functions from which we estimated the effective aperture due to the optical photon spreading. The optical crosstalk was most severely affected by the thickness of photodiode passivation layer. The effective aperture due to the optical crosstalk was about 110% of the detector pixel aperture for a 0.1 mm-thick passivation layer, and this signal blur was appeared as a relative error of about 3-4% in mismatches between CT images with and without the optical crosstalk. The detailed simulation results are shown and will be very useful for the design of CT detectors.

  11. [Hyperthyroidism caused by a TSH producing pituitary adenoma].

    Science.gov (United States)

    Prasch, F; Knosp, S E; Steinbach, R; Wogritsch, S; Hurtl, I; Greifeneder, M; Holm, C; Najemnik, C; Dudczak, R

    1999-01-01

    Elevated levels of free triiodothyronine (fT3) of 8.8 ng/dl (normal range 2.0 to 4.2) and free thyroxin (fT4) of 3.5 pg/ml (0.8 to 1.7) were found in the course of an examination of a 53-year old patient due to a planned hysterectomy. As thyrotropin (TSH) also was elevated with 5.8 mU/l (0.4 to 4.5), these findings corresponded to an inappropriate secretion of TSH (IST). Additional examinations revealed a blunted rise of TSH secretion after i.v. injection of 200 micrograms thyrotropin releasing hormone (TRH) as well as lacking suppression of TSH secretion after oral doses of 75 micrograms T3 during one week. alpha-TSH levels with 3.7 micrograms/l were elevated in comparison to a matched normal sample just as the molar ratio alpha-TSH/TSH with 6.95 and sex hormone-binding globulin (SHBG) with 175 nmol/l and showed an absence of inhibition in the T3 suppression test. These results were suggestive of neoplastic inappropriate secretion of TSH (nIST) due to a TSH-secreting pituitary adenoma. In concordance, the magnetic resonance imaging (MRI) showed a 1 cm tumor in the sella. The adenoma could also be visualized by 111In-octreotide and 123I-epidepride scintigraphies of the pituitary gland. After transsphenoidal resection, histological examination of the tumor resulted in the finding of a TSH-secreting adenoma. Postoperative TSH levels were not detectable, indicating the complete removal of the adenoma. Levels of fT3 and fT4 were slightly below normal with 1.9 pg/ml and 0.7 ng/dl, respectively. A control scintigraphy with 111In-octreotide following an equivocal MRI showed no uptake in the pituitary. PMID:10230475

  12. Dopamine receptor expression and function in corticotroph pituitary tumors.

    Science.gov (United States)

    Pivonello, Rosario; Ferone, Diego; de Herder, Wouter W; Kros, Johan M; De Caro, Maria Laura Del Basso; Arvigo, Marica; Annunziato, Lucio; Lombardi, Gaetano; Colao, Annamaria; Hofland, Leo J; Lamberts, Steven W J

    2004-05-01

    The role of dopamine agonist treatment in corticotroph pituitary tumors is controversial. The aim of this study was to evaluate D(2) receptor expression in 20 corticotroph pituitary tumors and to correlate it to the in vitro effect of dopamine agonists on ACTH secretion and the in vivo effect of short-term cabergoline treatment on cortisol secretion. D(2) expression was evaluated by receptor-ligand binding, immunohistochemistry, and RT-PCR. A 50% or more decrease in daily urinary cortisol levels was considered a significant clinical response. At receptor-ligand binding, specific binding of [(125)I]epidepride was found in 80% of cases. At immunohistochemistry, specific D(2) immunostaining was found in 75% of cases. D(2) expression was found in 83.3% of cases (D(2long) in 40%, D(2short) in 20%, and both in 40%) by RT-PCR. Significant in vitro inhibition of ACTH secretion was found in 100% of D(2)-positive cases, but not in 100% of D(2)-negative cases by either bromocriptine or cabergoline. A significant in vivo inhibition of cortisol secretion after 3-month cabergoline treatment was found in 60%, although a normalization of cortisol secretion was found in 40% of cases. All cabergoline-responsive cases were associated with D(2) expression, whereas all noncabergoline-responsive cases but one were not associated with D(2) expression. In conclusion, functional D(2) receptors were expressed in approximately 80% of corticotroph pituitary tumors. The effectiveness of cabergoline in normalizing cortisol secretion in 40% of cases supports its therapeutic use in the management of Cushing's disease. PMID:15126577

  13. Brain-Pituitary Axis Development In The CEBAS Minimodule

    Science.gov (United States)

    Schreibman, Martin P.; Magliulo-Cepriano, Lucia

    2001-01-01

    The CEBAS minimodule system is a man-made aquatic ecological system that incorporates animals, plants, snails, and microorganisms. It has been proposed that CEBAS will lead to a multigenerational experimental facility for utilization in a space station as well as for the development of an aquatic CELSS to produce animal and plant biomass for human nutrition. In this context, research on the reproductive biology of the organisms within the system should receive the highest priority. 1bus, the goals of our proposal were to provide information on space-flight-induced changes in the brain-pituitary axis and in the organs that receive information from the environment in the vertebrate selected for the CEBAS Minimodule program, the freshwater teleost Xiphophorus helleri (the swordtail). We studied the development of the brain- pituitary axis in neonates, immature and mature swordtails using histology, cytology, immunohistochemistry, morphometry, and in situ histochemistry to evaluate the synthesis, storage, and release of neurotransmitters, neuroregulatory peptides, neurohormones, and pituitary hormones as well as the structure of the organs and cells that produce, store, or are the target organs for these substances. We flew experiments in the CEBAS-minimodule on two shuttle missions, STS-89 and STS-90. In both flights four gravid females and about 200 juvenile (7 days old) swordtails (Xiphophorus helleri) constituted the aquatic vertebrates to be studied, in addition to the plants and snails that were studied by other team members. In a sample sharing agreement developed with Dr. Volker Bluem, organizer of the CEBAS research program, we received a small number of the juveniles and shared the brains of two adult females.

  14. Dysregulation of circadian rhythms following prolactin-secreting pituitary microadenoma.

    Science.gov (United States)

    Borodkin, Katy; Ayalon, Liat; Kanety, Hanna; Dagan, Yaron

    2005-01-01

    A patient who developed an irregular sleep-wake pattern following prolactin-secreting pituitary microadenoma is described. The patient reported difficulties in sleep onset and awakening at the desired time, which caused major dysfunction in his daily life activities. Despite these difficulties, the sleep-related complaints of the patient remained unrecognized for as long as three yrs. Statistical analyses of the patient's rest-activity patterns revealed that the disruption of the sleep-wake circadian rhythm originated from a disharmony between ultradian (semicircadian) and circadian components. The circadian component displayed shorter than 24 h periodicity most of the time, but the semicircadian component fluctuated between longer and shorter than 12 h periods. Additionally, desynchrony in terms of period length was found in the tentative analyses of the rest-activity pattern, salivary melatonin, and oral temperature. While the salivary melatonin time series data could be characterized by a best-fit cosine curve of 24 h, the time series data of oral temperature was more compatible with 28 h best-fit curve. The rest-activity cycle during the simultaneous measurements, however, was best approximated by a best-fit curve of 21 h. The dysregulation of circadian rhythms occurred concomitantly, but not beforehand, with the onset of pituitary disease, thus suggesting an association between the two phenomena. This association may have interesting implications to the modeling of the circadian time-keeping system. This case also highlights the need to raise the awareness to circadian rhythm sleep disorders and to consider disruptions of sleep-wake cycle in patients with pituitary adenoma. PMID:15865328

  15. Lectin Histochemical Study of Vasculogenesis During Rat Pituitary Morphogenesis

    Directory of Open Access Journals (Sweden)

    Ali Reza Ebrahimzadeh Bideskan

    2011-01-01

    Full Text Available Objective(s The aim of this study was to investigate glycoconjugates distribution patterns as well as their changes during the course of pituitary portal vasculogenesis and angiogenesis.Materials and MethodsFormalin fixed paraffin sections of 10 to 20 days of Sprague Dawly rat fetuses were processed for histochemical studies using four different horseradish peroxidase (HRP conjugated lectins. Orange peel fungus (OFA, Vicica villosa (VVA, Glycine max (SBA and Wistaria floribunda (WFA specific for α-L-Fucose, D-Gal, α, ß-D-GalNAc and D- GalNAc terminal sugars of glycoconjugates respectively.ResultsOur finding indicated that adenohypophysal cells reacted with OFA on gestational day 10 (E10 and increased progressively to E14. Staining intensity did not change from days 14 to17, then after increased following days to E20 significantly (P< 0.05. A few cells around Rathke’s pouch reacted with VVA on E13, increased to E14 and decreased significantly afterward (P< 0.05. Reaction of some cells around Rathke’s pouch reacted with SBA on E14. This visible reaction was the same as E18 and decreased later (P< 0.05. Many cells around Rathke’s pouch reacted with WFA on E13 and increased on E 14 and E15 and decreased thereafter (P< 0.05.ConclusionReactions of OFA and other tested lectins with endothelial cells around Rathke’s pouch and developing pars distalis were different. These results suggest that embryonic origin of hypophiseal pituitary portal (HPP system endothelial cells are not the same and our finding also indicated that glycoconjugates with terminal sugars α-L-Fucose, D-Gal, α, ß-D-GalNAc may play critical role(s in cell interactions and tissue differentiations such as vasculogensis and angiogenesis as well as other developmental precursors in formation of the pituitary gland.

  16. Anticancer effect of genistein on BG-1 ovarian cancer growth induced by 17 β-estradiol or bisphenol A via the suppression of the crosstalk between estrogen receptor alpha and insulin-like growth factor-1 receptor signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyung-A; Park, Min-Ah; Kang, Nam-Hee; Yi, Bo-Rim; Hyun, Sang-Hwan; Jeung, Eui-Bae; Choi, Kyung-Chul, E-mail: kchoi@cbu.ac.kr

    2013-11-01

    The interaction between estrogen receptor (ER) and insulin-like growth factor-1 receptor (IGF-1R) signaling pathway plays an important role in proliferation of and resistance to endocrine therapy to estrogen dependent cancers. Estrogen (E2) upregulates the expression of components of IGF-1 system and induces the downstream of mitogenic signaling cascades via phosphorylation of insulin receptor substrate-1 (IRS-1). In the present study, we evaluated the xenoestrogenic effect of bisphenol A (BPA) and antiproliferative activity of genistein (GEN) in accordance with the influence on this crosstalk. BPA was determined to affect this crosstalk by upregulating mRNA expressions of ERα and IGF-1R and inducing phosphorylation of IRS-1 and Akt in protein level in BG-1 ovarian cancer cells as E2 did. In the mouse model xenografted with BG-1 cells, BPA significantly increased a tumor burden of mice and expressions of ERα, pIRS-1, and cyclin D1 in tumor mass compared to vehicle, indicating that BPA induces ovarian cancer growth by promoting the crosstalk between ER and IGF-1R signals. On the other hand, GEN effectively reversed estrogenicity of BPA by reversing mRNA and protein expressions of ERα, IGF-1R, pIRS-1, and pAkt induced by BPA in cellular model and also significantly decreased tumor growth and in vivo expressions of ERα, pIRS-1, and pAkt in xenografted mouse model. Also, GEN was confirmed to have an antiproliferative effect by inducing apoptotic signaling cascades. Taken together, these results suggest that GEN effectively reversed the increased proliferation of BG-1 ovarian cancer by suppressing the crosstalk between ERα and IGF-1R signaling pathways upregulated by BPA or E2.

  17. Modeling Inter-Pixel Crosstalk in Teledyne Imaging Sensors H4RG Detectors

    CERN Document Server

    Dudik, R P; Dorland, B N; Veillette, D; Waczynski, A; Lane, B; Loose, M; Kan, E; Waterman, J; Pravdo, S

    2012-01-01

    CMOS-hybrid arrays have recently surfaced as competitive optical detectors for use in ground- and space-based astronomy. One source of error in these detectors that does not appear in more traditional CCD arrays is the inter-pixel capacitance component of crosstalk. In this paper we use a single pixel reset method to model inter-pixel capacitance (IPC). We combine this IPC model with a model for charge diffusion to estimate the total crosstalk on H4RG arrays. Finally, we compare our model results to Fe55 data obtained using an astrometric camera built to test the H4RG-B0 generation detectors.

  18. A Novel Metamaterial Structure to Reduce Far-End Crosstalk in Printed Circuit Boards

    OpenAIRE

    R.Azhagumurugan; Indumathi, P.

    2014-01-01

    Far-End crosstalk is a common problem in a printed circuit boards when two transmission lines are in close proximity. This paper proposes a newly designed method to reduce the far-end crosstalk using metamaterials as a complementary split ring resonator (CSRRs). The CSRRs are etched in the ground plane and are used to control the radiated electromagnetic fileds. Comparative analyses are taken for three cases with solid ground plane etching one CSRR and 2 CSRRs in the ground plane. Analysis sh...

  19. Clean Beam Patterns with Low Crosstalk Using 850 GHz Microwave Kinetic Inductance Detectors

    Science.gov (United States)

    Yates, S. J. C.; Baselmans, J. J. A.; Baryshev, A. M.; Doyle, S.; Endo, A.; Ferrari, L.; Hochgürtel, S.; Klein, B.

    2014-09-01

    We present modeling of distributed /4 microwave kinetic inductance detectors (MKIDs) showing how electromagnetic cross coupling between the MKID resonators can occur at frequencies corresponding to the microwave readout signal (4-8 GHz). We then show system beam pattern measurements in the reimaged focal plane of a 72 detector array of lens-antenna coupled MKIDs at 850 GHz, which enables a direct measure of any residual optical crosstalk. With use of transmission line bridges we see no residual cross coupling between MKIDs and hence low crosstalk down to the 30 dB level, with near Gaussian shape (limited by reimaging optics) to 10 dB level.

  20. Zero-crossing detector with sub-microsecond jitter and crosstalk

    Science.gov (United States)

    Dick, G. John; Kuhnle, Paul F.; Sydnor, Richard L.

    1990-01-01

    A zero-crossing detector (ZCD) was built and tested with a new circuit design which gives reduced time jitter compared to previous designs. With the new design, time jitter is reduced for the first time to a value which approaches that due to noise in the input amplifying stage. Additionally, with fiber-optic transmission of the output signal, crosstalk between units has been eliminated. The measured values are in good agreement with circuit noise calculations and approximately ten times lower than that for ZCD's presently installed in the JPL test facility. Crosstalk between adjacent units was reduced even more than the jitter.