| 1. |
- Schill, Fredrika, et al.
(författare)
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Pituitary Metastases : A Nationwide Study on Current Characteristics With Special Reference to Breast Cancer
- 2019
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : Oxford University Press. - 0021-972X .- 1945-7197. ; 104:8, s. 3379-3388
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate the contemporary presentation of pituitary metastases. Patients: Thirty-eight patients diagnosed with pituitary metastases from 1996 to 2018 in Sweden.Methods: Pituitary metastases were confirmed by histopathology (n = 27) or considered highly likely according to radiological findings, including rapid tumor progression (n = 11). Medical records were reviewed and cellar images reexamined centrally.Results: Breast and lung cancers were the most common primary tumors, in 45% and 21% of patients, respectively. Sixty-seven percent of breast cancers overexpressed human epidermal growth factor receptor 2 (HER2); 53% of pituitary metastases from breast cancers appeared >= 10 years after diagnosis of the primary tumor. At presentation, 71% appeared to have ACTH deficiency, 65% had TSH deficiency, and 26% had diabetes insipidus. Fatigue, nausea/vomiting, loss of appetite, weight loss, myalgia, and/or arthralgia were reported in 47% of patients with morning cortisol <100 nmol/L vs 23% with cortisol >= 200 nmol/L. Sixteen patients had visual field defects, and eight had diplopia. Intrasellar and suprasellar tumor growth was the most frequent finding. Initially, a pituitary adenoma was considered the etiology in 18% of patients. Radiotherapy, pituitary surgery, and chemotherapy were used in 68%, 68%, and 11% of patients, respectively. One and 2 years after diagnosis of pituitary metastases, 50% and 26% of patients were alive.Conclusion: Pituitary metastases may be mistaken for pituitary adenomas and can appear late, especially in breast cancer. Breast cancers overexpressing HER2 seem prone to metastasize to the pituitary. Hypocortisolism may be misdiagnosed as cancer-related malaise. An increased awareness of pituitary metastases and undiagnosed pituitary failure can improve management in these patients.
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| 2. |
- Trotter, Dinko E. Gonzalez, et al.
(författare)
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In Vivo Imaging of the Programmed Death Ligand 1 by F-18 PET
- 2017
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 58:11, s. 1852-1857
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Tidskriftsartikel (refereegranskat)abstract
- Programmed death ligand 1 (PD-L1) is an immune regulatory ligand that binds to the T-cell immune check point programmed death 1. Tumor expression of PD-L1 is correlated with immune suppression and poor prognosis. It is also correlated with therapeutic efficacy of programmed death 1 and PD-L1 inhibitors. In vivo imaging may enable real-time follow-up of changing PD-L1 expression and heterogeneity evaluation of PD-L1 expression across tumors in the same subject. We have radiolabeled the PD-L1-binding Affibody molecule NOTA-Z(PD-L1_1) with F-18 and evaluated its in vitro and in vivo binding affinity, targeting, and specificity. Methods: The affinity of the PD-L1-binding Affibody ligand Z(PD-L1_1) was evaluated by surface plasmon resonance. Labeling was accomplished by maleimide coupling of NOTA to a unique cysteine residue and chelation of F-18-AlF. In vivo studies were performed in PD-L1-positive, PD-L1-negative, and mixed tumor-bearing severe combined immunodeficiency mice. Tracer was injected via the tail vein, and dynamic PET scans were acquired for 90 min, followed by gamma-counting biodistribution. Immunohistochemical staining with an antibody specific for anti-PD-L1 (22C3) was used to evaluate the tumor distribution of PD-L1. Immunohistochemistry results were then compared with ex vivo autoradiographic images obtained from adjacent tissue sections. Results: NOTA-Z(PD-L1_1) was labeled, with a radiochemical yield of 15.1% +/- 5.6%, radiochemical purity of 96.7% +/- 2.0%, and specific activity of 14.6 +/- 6.5 GBq/mu mol. Surface plasmon resonance showed a NOTA-conjugated ligand binding affinity of 1 nM. PET imaging demonstrated rapid uptake of tracer in the PD-L1-positive tumor, whereas the PD-L1-negative control tumor showed little tracer retention. Tracer clearance from most organs and blood was quick, with biodistribution showing prominent kidney retention, low liver uptake, and a significant difference between PD-L1-positive (percentage injected dose per gram [%ID/g] = 2.56 +/- 0.33) and -negative (% ID/g = 0.32 +/- 0.05) tumors (P = 0.0006). Ex vivo autoradiography showed excellent spatial correlation with immunohistochemistry in mixed tumors. Conclusion: Our results show that Affibody ligands can be effective at targeting tumor PD-L1 in vivo, with good specificity and rapid clearance. Future studies will explore methods to reduce kidney activity retention and further increase tumor uptake.
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| 3. |
- Wahlberg, Elisabet, et al.
(författare)
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Identification of proteins that specifically recognize and bind protofibrillar aggregates of amyloid-β
- 2017
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Protofibrils of the 42 amino acids long amyloid-β peptide are transient pre-fibrillar intermediates in the process of peptide aggregation into amyloid plaques and are thought to play a critical role in the pathology of Alzheimer's disease. Hence, there is a need for research reagents and potential diagnostic reagents for detection and imaging of such aggregates. Here we describe an in vitro selection of Affibody molecules that bind to protofibrils of Aβ42cc, which is a stable engineered mimic of wild type Aβ42 protofibrils. Several binders were identified that bind Aβ42cc protofibrils with low nanomolar affinities, and which also recognize wild type Aβ42 protofibrils. Dimeric head-to-tail fusion proteins with subnanomolar binding affinities, and very slow dissociation off-rates, were also constructed. A mapping of the chemical properties of the side chains onto the Affibody scaffold surface reveals three distinct adjacent surface areas of positively charged surface, nonpolar surface and a polar surface, which presumably match a corresponding surface epitope on the protofibrils. The results demonstrate that the engineered Aβ42cc is a suitable antigen for directed evolution of affinity reagents with specificity for wild type Aβ42 protofibrils.
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