Headaches in Patients with Pituitary Tumors: a Clinical Conundrum.

PURPOSE OF REVIEW: Pituitary tumors account for approximately 17% of all intracranial neoplasms, with the majority being pituitary adenomas. Often, these are found incidentally during a workup for headache; however, the relationship between symptom and pathology remains unclear. The purpose of this article is to review the most recent literature on the epidemiology, pathophysiology, and management of headaches in patients with pituitary tumors. RECENT FINDINGS: The current literature is limited, with few prospective trials focusing on this question. With the exception of pituitary apoplexy, the relationship between headaches and pituitary masses remains unclear. Intervention does not always improve headache and can lead to development of new headache syndromes. Further research is needed to better elucidate the relationship between pituitary tumors and headaches. Headache alone is rarely an indication for surgical management of a pituitary adenoma.

Quantitative analysis of the detergent-insoluble brain proteome in frontotemporal lobar degeneration using SILAC internal standards.

A hallmark of neurodegeneration is the aggregation of disease related proteins that are resistant to detergent extraction. In the major pathological subtype of frontotemporal lobar degeneration (FTLD), modified TAR-DNA binding protein 43 (TDP-43), including phosphorylated, ubiquitinated, and proteolytically cleaved forms, is enriched in detergent-insoluble fractions from post-mortem brain tissue. Additional proteins that accumulate in the detergent-insoluble FTLD brain proteome remain largely unknown. In this study, we used proteins from stable isotope-labeled (SILAC) human embryonic kidney 293 cells (HEK293) as internal standards for peptide quantitation across control and FTLD insoluble brain proteomes. Proteins were identified and quantified by liquid-chromatography coupled with tandem mass spectrometry (LC-MS/MS) and 21 proteins were determined to be enriched in FTLD using SILAC internal standards. In parallel, label-free quantification of only the unlabeled brain derived peptides by spectral counts (SC) and G-test analysis identified additional brain-specific proteins significantly enriched in disease. Several proteins determined to be enriched in FTLD using SILAC internal standards were not considered significant by G-test due to their low total number of SC. However, immunoblotting of FTLD and control samples confirmed enrichment of these proteins, highlighting the utility of SILAC internal standard to quantify low-abundance proteins in brain. Of these, the RNA binding protein PTB-associated splicing factor (PSF) was further characterized because of structural and functional similarities to TDP-43. Full-length PSF and shorter molecular weight fragments, likely resulting from proteolytic cleavage, were enriched in FTLD cases. Immunohistochemical analysis of PSF revealed predominately nuclear localization in control and FTLD brain tissue and was not associated with phosphorylated pathologic TDP-43 neuronal inclusions. However, in a subset of FTLD cases, PSF was aberrantly localized to the cytoplasm of oligodendrocytes. These data raise the possibility that PSF directed RNA processes in oligodendrocytes are altered in neurodegenerative disease.

Causes of Death and End-of-Life Care in Patients With Intracranial High-Grade Gliomas: A Retrospective Observational Study.

BACKGROUND AND OBJECTIVES: To understand patterns of care and circumstances surrounding end of life in patients with intracranial gliomas. METHODS: We retrospectively analyzed end-of-life circumstances in patients with intracranial high-grade gliomas at Columbia University Irving Medical Center who died from January 2014 to February 2019, including cause of death, location of death, and implementation of comfort measures and resuscitative efforts. RESULTS: There were 152 patients (95 men, 57 women; median age at death 61.5 years, range 24-87 years) who died from January 2014 to February 2019 with adequate data surrounding end-of-life circumstances. Clinical tumor progression (n = 117, 77.0%) was the most common cause of death, with all patients transitioned to comfort measures. Other causes included, but were not limited to, infection (19, 12.5%); intratumoral hemorrhage (5, 3.3%); seizures (8, 5.3%); cerebral edema (4, 2.6%); pulmonary embolism (4, 2.6%); autonomic failure (2, 1.3%); and hemorrhagic shock (2, 1.3%). Multiple mortal events were identified in 10 (8.5%). Seventy-three patients (48.0%) died at home with hospice. Other locations were inpatient hospice (40, 26.3%); acute care hospital (34, 22.4%), including 27 (17.8%) with and 7 (4.6%) without comfort measures; skilled nursing facility (4, 3.3%), including 3 (2.0%) with and 1 (0.7%) without comfort measures; or religious facility (1, 0.7%) with comfort measures. Acute cardiac or pulmonary resuscitation was performed in 20 patients (13.2%). DISCUSSION: Clinical tumor progression was the most common (77.0%) cause of death, followed by infection (12.5%). Hospice or comfort measures were ultimately implemented in 94.7% of patients, although resuscitation was performed in 13.2%. Improved understanding of circumstances surrounding death, frequency of use of hospice services, and frequency of resuscitative efforts in patients with gliomas may allow physicians to more accurately discuss end-of-life expectations with patients and caregivers, facilitating informed care planning.

Chemotherapy Treatment and Trials in Low-Grade Gliomas.

There is currently no universally accepted standard of care treatment for low-grade gliomas, a molecularly heterogeneous group of tumors with similarly heterogeneous clinical outcomes. Risk stratification by clinical and molecular features is useful to help determine which patients benefit the most from adjuvant treatment. The addition of combination chemotherapy with procarbazine, lomustine, and vincristine confers survival advantage, as likely does temozolomide, but radiochemotherapy may not be appropriate for all patients owing to its toxicity profile. We review the approach to treatment in patients with low-grade gliomas with an emphasis on the clinical trials focusing on adjuvant chemotherapy in this population.

Widely metastatic atypical pituitary adenoma with mTOR pathway STK11(F298L) mutation treated with everolimus therapy.

Pituitary adenomas are the commonest intracranial tumor, but metastases are rare (0.2% yearly incidence) and portend poor prognosis. CAPecitabine and TEMozolomide improved outcomes for neuroendocrine tumors. However, no chemotherapy is approved for refractory pituitary carcinomas. Next-generation sequencing revealed an actionable mTOR pathway STK11 mutation in a woman with adrenocorticotropic hormone-secreting pituitary carcinoma refractory to six resections, radiation and CAPecitabine and TEMozolomide. Given efficacy in preclinical pancreatic cancer models with STK11 mutations, she received radiation and everolimus leading to clinical improvement and stability on MRI and PET for >6 months. She ultimately expired from widely metastatic disease. Next-generation sequencing can identify actionable mutations in rare or treatment refractory tumors. Earlier targeted therapy may improve outcomes.

Exploring the potential of the platelet membrane proteome as a source of peripheral biomarkers for Alzheimer's disease.

INTRODUCTION: Peripheral biomarkers to diagnose Alzheimer's disease (AD) have not been established. Given parallels between neuron and platelet biology, we hypothesized platelet membrane-associated protein changes may differentiate patients clinically defined with probable AD from noncognitive impaired controls. METHODS: Purified platelets, confirmed by flow cytometry were obtained from individuals before fractionation by ultracentrifugation. Following a comparison of individual membrane fractions by SDS-PAGE for general proteome uniformity, equal protein weight from the membrane fractions for five representative samples from AD and five samples from controls were pooled. AD and control protein pools were further divided into molecular weight regions by one-dimensional SDS-PAGE, prior to digestion in gel. Tryptic peptides were analyzed by reverse-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Ionized peptide intensities were averaged for each identified protein in the two pools, thereby measuring relative protein abundance between the two membrane protein pools. Log2-transformed ratio (AD/control) of protein abundances fit a normal distribution, thereby permitting determination of significantly changed protein abundances in the AD pool. RESULTS: We report a comparative analysis of the membrane-enriched platelet proteome between patients with mild to moderate AD and cognitively normal, healthy subjects. A total of 144 proteins were determined significantly altered in the platelet membrane proteome from patients with probable AD. In particular, secretory (alpha) granule proteins were dramatically reduced in AD. Of these, we confirmed significant reduction of thrombospondin-1 (THBS1) in the AD platelet membrane proteome by immunoblotting. There was a high protein-protein connectivity of proteins in other pathways implicated by proteomic changes to the proteins that define secretory granules. CONCLUSIONS: Depletion of secretory granule proteins is consistent with a preponderance of post-activated platelets in circulation in AD. Significantly changed pathways implicate additional AD-related defects in platelet glycoprotein synthesis, lipid homeostasis, amyloidogenic proteins, and regulators of protease activity, many of which may be useful plasma membrane-expressed markers for AD. This study highlights the utility of LC-MS/MS to quantify human platelet membrane proteins and suggests that platelets may serve as a source of blood-based biomarkers in neurodegenerative disease.

Analysis of a membrane-enriched proteome from postmortem human brain tissue in Alzheimer's disease.

PURPOSE: The present study is a discovery mode proteomics analysis of the membrane-enriched fraction of postmortem brain tissue from Alzheimer's disease (AD) and control cases. This study aims to validate a method to identify new proteins that could be involved in the pathogenesis of AD and potentially serve as disease biomarkers. EXPERIMENTAL DESIGN: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze the membrane-enriched fraction of human postmortem brain tissue from five AD and five control cases of similar age. Biochemical validation of specific targets was performed by immunoblotting. RESULTS: One thousand seven hundred and nine proteins were identified from the membrane-enriched fraction of frontal cortex. Label-free quantification by spectral counting and G-test analysis identified 13 proteins that were significantly changed in disease. In addition to Tau (MAPT), two additional proteins found to be enriched in AD, ubiquitin carboxy-terminal hydrolase 1 (UCHL1), and syntaxin-binding protein 1 (Munc-18), were validated through immunoblotting. DISCUSSION AND CLINICAL RELEVANCE: Proteomic analysis of the membrane-enriched fraction of postmortem brain tissue identifies proteins biochemically altered in AD. Further analysis of this subproteome may help elucidate mechanisms behind AD pathogenesis and provide new sources of biomarkers.