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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

EXAMINATION OF BASAL NEUROENDOCRINE LEVELS IN OIF/OEF/OND VETERANS

Hawn, Sage E. 01 January 2015 (has links)
Abstract EXAMINATION OF BASAL NEUROENDOCRINE LEVELS IN OIF/OEF/OND VETERANS By Sage E. Hawn, B.S. A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2015. Major Director: Ananda B. Amstadter, PhD. Associate Professor Departments of Psychiatry, Psychology, & Human and Molecular Genetics High rates of combat exposure exist among veterans of the recent conflicts, and are associated with debilitating mental health conditions, including posttraumatic stress disorder (PTSD). Numerous psychosocial and biologic factors are associated with PTSD, including the HPA-axis. The present study aimed to compare baseline neuroendocrine levels by trauma group (PTSD, trauma exposed [TE], and non-trauma controls [NTC]) among a sample of young veterans. An exploratory aim was to examine potential moderators of the relation between PTSD and basal cortisol/ACTH. Group differences in cortisol were nominally significant, with the NTC group having significantly higher cortisol than the PTSD group. Sleep disturbance was the only moderator of this relationship in cortisol, although lifetime trauma load significantly predicted basal cortisol across all models. No significant effects were demonstrated for ACTH. Examining effects of trauma on basal physiology provides a critical stepping ground for future investigations that may inform targeted prevention and intervention efforts.
22

"Marcação do peptídeo Dota-TYR3-Octreotato com radioiodo e estudo da biodistribuição e afinidade por células de carcinoma pancreático" / LABELING OF THE PEPTIDE DOTA-TYR3-OCTREOTATE WITH RADIOIODINE AND BIODISTRIBUTION AND AR42J NEUROENDOCRINE TUMOR AFFINITY STUDY IN MICE

Nagamati, Lucio Takeshi 19 December 2006 (has links)
Os tumores neuroendócrinos são raros, ocorrem principalmente no trato gastrointestinal, mas outros sistemas são acometidos como pele, pulmões e sistema nervoso. São ricos em receptores de somatostatina (SM) do tipo 2 (SSTR2) e podem secretar hormônios em excesso. Peptídeos análogos sintéticos da SM são de grande utilidade por possuírem meia vida maior do que a SM e, assim, podem ser utilizados para melhora clínica destes pacientes devido sua ação inibitória tumoral. A marcação destes peptídeos com radioisótopos permite a obtenção de imagens, de boa relação custo-eficácia comprovada, e realização de terapia. O peptídeo utilizado, DOTA-Tyr3-octreotato (DOTATATO), possui afinidade ao receptor SSTR2 muito maior do que o utilizado comercialmente hoje, é facilmente radioiodado e possui biodistribuição favorável para diagnóstico e terapia devido à presença do quelante DOTA. Estudamos a influência de vários fatores na pureza radioquímica do composto marcado além da estabilidade da marcação e biodistribuição em camundongos Swiss e Nude, normais e com tumor de células AR42J, além da estimativa de dose absorvida. Observamos fácil e estável radioiodação do peptídeo à razão molar peptídeo/radioiodo (131I) de 2,73, que gerou espécie radioquímica com tempo de retenção de 22,7 minutos na cromatografia líquida de alta eficiência e que apresentou biodistribuição e dosimentria favoráveis para a realização de imagens e terapia dos pacientes com tumores neuroendócrinos, ao contrário do que dados antigos da literatura mostravam nos compostos radioativos sem quelante associado. Outras razões molares não se mostraram eficientes, com outras espécies radioquímicas e biodistribuição desfavorável. Um estudo dosimétrico em pacientes com tumores neuroendócrinos pode ser realizado num futuro próximo. / Neuroendocrine tumors are rare and affect mainly the gastrointestinal tract but other systems are also affected like the skin, lungs and the nervous system. They are rich in type 2 somatostatin (SM) receptors (SSTR2) and may secrete hormones in excess. Synthetic SM derivative peptides are of great utility because presented bigger half life when compared to SM and can be used to clinical improvement of these patients due to its tumoral inhibitory action. The labeling of these peptides with radioisotopes allowed the acquisition of images with favourable cost-efficiency relationship and use in therapy. The peptide, DOTATyr3- octreotate (DOTATATE), has much more affinnity for the SSTR2 receptor than the peptide commercially used nowadays, is easily radioiodinated and has a favourable biodistribution for diagnosis and treatment due to the presence of the chelator DOTA. We have studied the influence of various factors on the radiochemical purity of the labeled compound as labeling stability, absorbed dose estimation and biodistribution in normal and AR42J cell tumor-bearing Swiss and Nude mice. We observed easy and stable peptide radioiodination at peptide/radioiodine (131I) ratio of 2.73 that produced a radiochemical species with retention time of 22.7 minutes at high performance liquid chromatography and presented a favourable biodistribution and dosimetry for imaging and therapy of patients with neuroendocrine tumors, just the opposite result observed the radioiodinated compounds without a chelator as described in the literature. Other molar peptide/radioiodine ratios did not showed good results, with various radiochemical species and unfavourable biodistribution. A possible dosimetric study in patients with neuroendocrine tumors may be carried out in the near future.
23

Neuroendocrine genomics for tumor variant discovery

Tessmann, Jonathon 01 May 2018 (has links)
An exome sequencing analysis pipeline was constructed to analyze NET germline and somatic samples. SNPs and INDELs were called and annotated from germline and somatic tissue. CNVs were also called for the tumor samples. This was accomplished using open source bioinformatics software that has been developed by the research community. Broad Institute "best practices" were followed. Some of the tools that were used include BWA, SAMtools, GATK, Varscan, VT, VEP, and GEMINI. Computational resources were provided by The University of Iowa NEON computer cluster. 57 germline samples and 15 tumor samples across 23 families with a history of NETs produced 4,452 germline variants, 1,695 somatic variants, 5,853 LOH events, and 627 CNV calls. False positive and driver candidacy filtering was applied. One family with Currarino syndrome has an inherited germline missense variant in MNX1. This variant has a phred-scaled Combined Annotation Dependant Depletion score of 35, putting it in the top 0.031% of deleterious variants. CNV analysis demonstrates that 8 of the 15 tumor samples have large-scale deletions of chromosome 18, three of which have nearly the entire chromosome deleted. An affected tumor suppressor gene in this region includes DCC, which is present in all three variant discovery techniques. Variant prioritization techniques are effective, but need further development to increase candidate variant/gene discovery rate.
24

Relationship between Quality of Life for Patients with Neuroendocrine Tumors and Novel Biomarkers

Ford-Scheimer, Stephanie L. 01 January 2017 (has links)
Research in the field of neuroendocrine tumors (NETs) has increased over the last decade, including studies focused on biochemical markers (biomarkers) of the disease. There is also growing interest in how NETs impact patients' quality of life (QOL). Consequently, there is a paucity of information about whether the expression of the specific disease biomarkers affects QOL as well as whether the primary tumor site impacts QOL. Using the explanatory model of health promotion and quality of life in chronic disabling conditions as the theoretical framework and data collected with the Norfolk QOL-NET instrument, this study's purpose was to fill that gap in knowledge through research questions addressing the relationship between the primary tumor site and NET patients' total QOL score as well as the effect of specific NET biomarkers on NET patients' total QOL score. Data were analyzed using descriptive statistics, one-way analysis of variance (ANOVA), regression analysis, and post hoc tests to determine significance. Results from an ANOVA showed that abnormal NET biomarkers affected total QOL (p = 0.011). In the analyses of whether the independent biomarker variables affected the dependent total QOL variable, only the result for Serotonin Normal was significant (p = 0.002). The presence of abnormal biomarker measurements also affected two of the Norfolk QOL-NET domains significantly, gastrointestinal and physical functioning (p = 0.005 and p = 0.030, respectively). By understanding the relationship between NETs and patient QOL, the potential positive social change implications are helping NET patients assess the severity of their condition, determining what affects their well-being, and using this information to help monitor their treatment/progress.
25

Dosimetry of Radionuclide Therapy with 177Lu-octreotate

Sandström, Mattias January 2011 (has links)
In radionuclide therapy it is still common to administer standard activities or to scale administered activity with blunt parameters such as body weight or surface area. This is not ideal because, due to considerable variation in kinetics, large safety margins have to be applied to avoid radiation damage to healthy organs, which causes under-treatment of many patients. To base the administered activity on individual dosimetry, as in other therapy modalities using ionizing radiation, will essentially solve this problem. However, dosimetry in radionuclide therapy is resource-demanding and debilitating for the patient because it involves a number of measurements to determine the kinetics of the therapy radionuclide and needs to be optimized for clinical feasibility. First, the ability to measure radioactivity distributions of radionuclides for therapy was investigated. SPECT measurements of 177Lu, which was later used clinically, showed good spatial resolution and a reasonable quantitative accuracy. A new method to calculate absorbed dose to solid risk organs and tumours was developed and applied in the clinic. Kinetic data were obtained by repeated SPECT measurements. Radiation concentration determined in small volumes of interest could then be multiplied by a constant to obtain absorbed dose because it was shown that cross-fire was negligible in organs with high activity concentration. The new dosimetry method, compared to other methods, was found to give better results with less effort. In addition, a method to calculate absorbed dose to bone marrow was developed and clinically implemented. In 200 patients, individual kinetics and absorbed dose were studied and variations were found to be large. Kidney was the dose-limiting organ in almost all patients (98.5%). Keeping the kidney dose < 23Gy, about half of the patients could receive 5, or up to 10 treatments instead of the stipulated 4.
26

"Marcação do peptídeo Dota-TYR3-Octreotato com radioiodo e estudo da biodistribuição e afinidade por células de carcinoma pancreático" / LABELING OF THE PEPTIDE DOTA-TYR3-OCTREOTATE WITH RADIOIODINE AND BIODISTRIBUTION AND AR42J NEUROENDOCRINE TUMOR AFFINITY STUDY IN MICE

Lucio Takeshi Nagamati 19 December 2006 (has links)
Os tumores neuroendócrinos são raros, ocorrem principalmente no trato gastrointestinal, mas outros sistemas são acometidos como pele, pulmões e sistema nervoso. São ricos em receptores de somatostatina (SM) do tipo 2 (SSTR2) e podem secretar hormônios em excesso. Peptídeos análogos sintéticos da SM são de grande utilidade por possuírem meia vida maior do que a SM e, assim, podem ser utilizados para melhora clínica destes pacientes devido sua ação inibitória tumoral. A marcação destes peptídeos com radioisótopos permite a obtenção de imagens, de boa relação custo-eficácia comprovada, e realização de terapia. O peptídeo utilizado, DOTA-Tyr3-octreotato (DOTATATO), possui afinidade ao receptor SSTR2 muito maior do que o utilizado comercialmente hoje, é facilmente radioiodado e possui biodistribuição favorável para diagnóstico e terapia devido à presença do quelante DOTA. Estudamos a influência de vários fatores na pureza radioquímica do composto marcado além da estabilidade da marcação e biodistribuição em camundongos Swiss e Nude, normais e com tumor de células AR42J, além da estimativa de dose absorvida. Observamos fácil e estável radioiodação do peptídeo à razão molar peptídeo/radioiodo (131I) de 2,73, que gerou espécie radioquímica com tempo de retenção de 22,7 minutos na cromatografia líquida de alta eficiência e que apresentou biodistribuição e dosimentria favoráveis para a realização de imagens e terapia dos pacientes com tumores neuroendócrinos, ao contrário do que dados antigos da literatura mostravam nos compostos radioativos sem quelante associado. Outras razões molares não se mostraram eficientes, com outras espécies radioquímicas e biodistribuição desfavorável. Um estudo dosimétrico em pacientes com tumores neuroendócrinos pode ser realizado num futuro próximo. / Neuroendocrine tumors are rare and affect mainly the gastrointestinal tract but other systems are also affected like the skin, lungs and the nervous system. They are rich in type 2 somatostatin (SM) receptors (SSTR2) and may secrete hormones in excess. Synthetic SM derivative peptides are of great utility because presented bigger half life when compared to SM and can be used to clinical improvement of these patients due to its tumoral inhibitory action. The labeling of these peptides with radioisotopes allowed the acquisition of images with favourable cost-efficiency relationship and use in therapy. The peptide, DOTATyr3- octreotate (DOTATATE), has much more affinnity for the SSTR2 receptor than the peptide commercially used nowadays, is easily radioiodinated and has a favourable biodistribution for diagnosis and treatment due to the presence of the chelator DOTA. We have studied the influence of various factors on the radiochemical purity of the labeled compound as labeling stability, absorbed dose estimation and biodistribution in normal and AR42J cell tumor-bearing Swiss and Nude mice. We observed easy and stable peptide radioiodination at peptide/radioiodine (131I) ratio of 2.73 that produced a radiochemical species with retention time of 22.7 minutes at high performance liquid chromatography and presented a favourable biodistribution and dosimetry for imaging and therapy of patients with neuroendocrine tumors, just the opposite result observed the radioiodinated compounds without a chelator as described in the literature. Other molar peptide/radioiodine ratios did not showed good results, with various radiochemical species and unfavourable biodistribution. A possible dosimetric study in patients with neuroendocrine tumors may be carried out in the near future.
27

A Rare Case of Non-Functional Urinary Bladder Paraganglioma

Kim, Do Young, M.D, Khan, Ali, M.D, Singal, Sakshi, M.D, Jaishankar, Devapiran, M.D 07 April 2022 (has links)
Urinary bladder paraganglioma (UBP) is a rare neuroendocrine neoplasm. It accounts for less than 1% of urinary bladder tumors and less than 6% among all types of paragangliomas. More commonly, UBP occurs in the female population aged 20-40 years old. UBP is classified into functional and non-functional types, and the majority is functional, leading to symptoms and signs of excess catecholamine, including hypertension, palpitation, syncope, and headache. Non-functional UBP comprises about 15% of UBPs and lacks the excess secretion of catecholamine, which often leads to misdiagnosis as urothelial cancer due to its rarity and nonspecific symptoms - increased urinary frequency/urgency and painless gross hematuria. Here, we present a rare case of a non-functional UBP. A 65-year-old male with BPH presented to ER with a 6-month history of urinary retention. He also was experiencing intermittent hematuria and dysuria during this time but otherwise remained asymptomatic without headache, dyspnea, wheezing, or diarrhea. Physical exam showed normal BP and no suprapubic tenderness on palpation. UA showed gross hematuria. Subsequent cystoscopy showed thickening of the bladder dome and an 8 mm lesion. Transurethral resection of bladder tumor (TURBT) was performed, and pathology showed 1 cm tumor confined to submucosa with questionable margins. Chromogranin, synaptophysin, CD56, GATA3, CD10 were stained positive; cytokeratin AE1/AE3, cytokeratin 34betaE12, SOX10, S100, and calretinin were negative. From morphology and immunochemistry, the diagnosis of UBP was made. Free metanephrine, plasma normetanephrine, 24-hour urine metanephrine and normetanephrine levels were not elevated. Post-TURBT MRI abdomen showed no other suspicious lesions. A wide re-resection of the bladder dome was performed due to the questionable margins from the initial surgery, and pathology showed benign bladder tissue with unremarkable immunostains, indicating no overt features of residual paraganglioma. Due to its paucity and uncertain biological behavior, the prognosis of UBP is not well established. While most UBP are benign, 10-15% of cases are malignant. High expression of VEGF and or abnormal vessel architecture in the tumor cells raise suspicion of malignancy. However, typically, definitive evidence of malignancy in paraganglioma is its invasion of adjacent organs or distant metastasis. The local recurrence rate ranges from 5-15%, thus necessitating long-term surveillance for 10-years. Systemic chemotherapy, including cyclophosphamide, vincristine, dacarbazine (CVD), or temozolomide, is necessary for distant metastatic or symptomatic disease. Iobenguane I-131 or Lutathera can be utilized with positive MIBG or 68Ga DOTATATE scan, respectively. Otherwise, surgical extirpation remains the choice of curative intent, and a multidisciplinary approach consisting of urologists, medical/radiation oncologists, and endocrinologists would be warranted for this rare entity of disease.
28

State-dependent changes in astrocyte regulation of extrasynaptic NMDA receptor signaling in neurosecretory neurons

Fleming, Tiffany M. January 2012 (has links)
No description available.
29

Dual signal transduction pathways activated by TSH receptors in rat primary 1 tanycyte cultures

Bolborea, M., Helfer, Gisela, Ebling, F.J.P., Barrett, P. 15 April 2015 (has links)
yes / Tanycytes play multiple roles in hypothalamic functions, including sensing peripheral nutrients and metabolic hormones, regulating neurosecretion and mediating seasonal cycles of reproduction and metabolic physiology. This last function reflects the expression of TSH receptors in tanycytes, which detect photoperiod-regulated changes in TSH secretion from the neighbouring pars tuberalis. The present overall aim was to determine the signal transduction pathway by which TSH signals in tanycytes. Expression of the TSH receptor in tanycytes of 10-day-old Sprague Dawley rats was observed by in situ hybridisation. Primary ependymal cell cultures prepared from 10-day-old rats were found by immunohistochemistry to express vimentin but not GFAP and by PCR to express mRNA for Dio2, Gpr50, Darpp-32 and Tsh receptors that are characteristic of tanycytes. Treatment of primary tanycyte/ependymal cultures with TSH (100 IU/l) increased cAMP as assessed by ELISA and induced a cAMP-independent increase in the phosphorylation of ERK1/2 as assessed by western blot analysis. Furthermore, TSH (100 IU/l) stimulated a 2.17-fold increase in Dio2 mRNA expression. We conclude that TSH signal transduction in cultured tanycytes signals via Gαs to increase cAMP and via an alternative G protein to increase phosphorylation of ERK1/2.
30

Characterization of Gene Expression During Adenosine 3':5'-Cyclic Monophosphate Induced Neuroendocrine Differentiation in Human Prostatic Adenocarcinoma

Goodin, Jeremy Lee 19 April 2002 (has links)
The LNCaP cell line is a versatile and useful model that is suitable for the study of human prostate cancer in vitro. The elevation of LNCaP intracellular cAMP levels through the addition of membrane permeable cAMP analogues, phosphodiesterase inhibitors, adenylate cyclase activators, or components of the cAMP signal transduction pathway can induce reversible neuroendocrine differentiation. Elucidation of those genes that are differentially expressed between undifferentiated prostate cancer cells and prostate cancer cells that have been induced to differentiate may present new insights for the molecular mechanisms governing neuroendocrine differentiation, early detection of prostate cancer, and/or potential targets for gene therapy. In this study, differential display PCR was used to identify 226 differentially expressed PCR products. Twelve of the differential display PCR products were confirmed by Northern blot analysis and cloned. DNA sequencing and database comparisons were performed. Among the differentially expressed genes, the human ribosomal S3a gene was identified as down regulated in response to LNCaP differentiation. In order to better ascertain the mechanism by which HRS3a gene expression is decreased during differentiation, the promoter region for this gene was analyzed. Electrophoretic mobility shift assay, antibody supershift assays, site-directed mutagenesis, and luciferase reporter gene analysis were employed to authenticate the roles of several transcription factors in the regulation of the HRS3a gene. Two cyclic AMP response elements, a Sp1 element and a GA-binding protein element, were involved in the regulation of HRS3a gene expression. In order to ascertain the effect of HRS3a down regulation in LNCaP cells, antisense phosphorothioate oligonucleotides were designed to inhibit HRS3a gene expression. Treatment of LNCaP cells with antisense HRS3a oligonucleotides did not influence cAMP induced neuroendocrine differentiation but antisense treatment did result in a decrease in LNCaP cell growth. In addition, it was determined that morphological changes associated with cAMP induced differentiation of LNCaP cells from the epithelial to the neuroendocrine state may not require alterations in gene expression nor the expression of novel proteins. / Ph. D.

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