Primary squamous cell carcinoma of the thyroid treated with concurrent chemoradiation and palliative immunotherapy: a case report.

BACKGROUND: Primary squamous cell carcinoma of the thyroid is a very rare malignancy with aggressive growth and poor prognosis. There is currently no consensus for treatment modality, however, most patients with primary squamous cell carcinoma of the thyroid are treated with surgery and adjuvant chemoradiation. CASE PRESENTATION: We report a rare case of primary squamous cell carcinoma of the thyroid in a 68-year-old White male who underwent chemoradiation and palliative immunotherapy after declining surgery. He was treated with intensity-modulated radiation therapy to 70 Gy in 35 fractions, with concurrent carboplatin-paclitaxel and palliative pembrolizumab. Local thyroid disease recurrence occurred at 6 months post-chemoradiation, and the patient died at 16 months post-chemoradiation. CONCLUSIONS: This is the first case report demonstrating the use of pembrolizumab as palliative therapy for primary squamous cell carcinoma of the thyroid. Our study also highlights the importance of chemoradiation in decreasing primary mass size and immunotherapy in preventing metastatic disease progression.

Risk of atrial fibrillation is increased in patients with exfoliation syndrome: the Utah project on exfoliation syndrome (UPEXS).

PURPOSE: Exfoliation syndrome, a systemic disorder with ocular manifestations, is associated with lysyl oxidase-like gene variants. Along with transforming growth factor beta-1, lysyl oxidase-like 1 is a key enzyme in stabilizing extracellular matrix and remodelling collagen/elastin. Given the role that transforming growth factor beta-1, lysyl oxidase-like gene variants and fibrosis play in atrial fibrillation, an association with exfoliation syndrome was investigated. METHODS: An exfoliation syndrome cohort of 2803 patients and an atrial fibrillation cohort of 43 694 patients aged 60-90 years at disease onset were identified using the Utah Population Database (1996-2015). Conditional logistic regression was used to estimate risk of atrial fibrillation in exfoliation syndrome patients and risk of exfoliation syndrome in atrial fibrillation patients compared with respective 5:1 sex- and age-matched control cohorts. Kaplan-Meier curves were examined to assess survival in atrial fibrillation patients by exfoliation syndrome status. RESULTS: Exfoliation syndrome patients had a 21% greater risk (95% CI 1.06-1.37; p < 0.0001) of atrial fibrillation. This was more pronounced in exfoliation syndrome patients with no hypertension history, who exhibited a 52% increased atrial fibrillation risk (95% CI 1.27-1.82; p < 0.0001). Atrial fibrillation patients exhibited a 20% increased risk of exfoliation syndrome (95% CI 1.07-1.35; p = 0.003), while atrial fibrillation patients with no hypertension had a 72% higher exfoliation risk (95% CI 1.45-2.03; p < 0.0001). Atrial fibrillation patients with exfoliation syndrome had a higher estimated probability of survival (alive at study end or at last follow-up) compared with patients with no exfoliation history (p < 0.0001, log-rank test). CONCLUSIONS: Exfoliation syndrome patients were at a statistically significant increased risk of atrial fibrillation. Similarly, atrial fibrillation patients were at a statistically significant higher risk of exfoliation, particularly when hypertension history was absent.

Association of Exfoliation Syndrome With Risk of Indirect Inguinal Hernia: The Utah Project on Exfoliation Syndrome.

Importance: Exfoliation syndrome (XFS) is a systemic connective tissue disease, and abnormal connective tissue metabolism is implicated in inguinal hernias (IH). Associating XFS with comorbid conditions may illuminate their underlying pathophysiology and affect clinical screening and treatment. Exfoliation syndrome involves altered systemic extracellular matrix (ECM) homeostasis involving elastin metabolism. Hernias occur owing to abnormal ECM synthesis, metabolism, or repair. Inguinal hernias involve weakening or rupture of the abdominal/groin wall. Objective: To determine an association between patients with XFS and patients with IH in Utah, possibly differing between direct or indirect hernia. Design, Setting, and Participants: Cross-sectional study in a large health care system of Utah hospitals and clinics. Conditional logistic regression odds ratios were used to estimate risk of XFS in patients with IH overall and by subtype (direct or indirect) compared with control individuals. Codes specific to direct and indirect IH with additional medical records review of 186 procedures were used to classify IH subtypes that were not prespecified. Bootstrap resampling with jackknife estimation used to calculate 95% confidence intervals. The model accounted for matching on sex and age and adjusted for body mass index and tobacco use. Population-based sample using medical records from 1996 to 2015 that identified 2594 patients 40 years or older on January 1, 1996, with surgical IH repair and 12 966 random control patients with no IH history matched 5:1 on sex and birth year. Data were analyzed between September 10, 2017, and October 23, 2017. Main Outcomes and Measures: Exfoliation syndrome outcome defined by diagnosis codes for XFS or exfoliation glaucoma from 1996 to 2015. Results: Participants were primarily white (2532 of 2594 patients, [96.1%]; 12 454 of 12 966 control individuals [97.6%]) and non-Hispanic (2396 of 2594 patients [92.4%]); 250 participants were women (9.6%). Of study participants, 22 patients with IH and 43 control individuals were diagnosed as having XFS, respectively. Patients with IH had a 2.3-fold risk for an XFS diagnosis compared with control individuals (95% CI, 1.4-3.5; P = .03), and XFS risk with indirect IH appeared especially pronounced. Conclusions and Relevance: Inguinal hernia was associated with an increased risk of XFS in this Utah population. Further work is needed to understand the pathophysiology, genetics, and environmental factors contributing to both diseases.

Correlations Between Macular, Skin, and Serum Carotenoids.

Purpose: Ocular and systemic measurement and imaging of the macular carotenoids lutein and zeaxanthin have been employed extensively as potential biomarkers of AMD risk. In this study, we systematically compare dual wavelength retinal autofluorescence imaging (AFI) of macular pigment with skin resonance Raman spectroscopy (RRS) and serum carotenoid levels in a clinic-based population. Methods: Eighty-eight patients were recruited from retina and general ophthalmology practices from a tertiary referral center and excluded only if they did not have all three modalities tested, had a diagnosis of macular telangiectasia (MacTel) or Stargardt disease, or had poor AFI image quality. Skin, macular, and serum carotenoid levels were measured by RRS, AFI, and HPLC, respectively. Results: Skin RRS measurements and serum zeaxanthin concentrations correlated most strongly with AFI macular pigment volume under the curve (MPVUC) measurements up to 9° eccentricity relative to MPVUC or rotationally averaged macular pigment optical density (MPOD) measurements at smaller eccentricities. These measurements were reproducible and not significantly affected by cataracts. We also found that these techniques could readily identify subjects taking oral carotenoid-containing supplements. Conclusions: Larger macular pigment volume AFI and skin RRS measurements are noninvasive, objective, and reliable methods to assess ocular and systemic carotenoid levels. They are an attractive alternative to psychophysical and optical methods that measure MPOD at a limited number of eccentricities. Consequently, skin RRS and MPVUC at 9° are both reasonable biomarkers of macular carotenoid status that could be readily adapted to research and clinical settings.

Retinal accumulation of zeaxanthin, lutein, and ß-carotene in mice deficient in carotenoid cleavage enzymes.

Carotenoid supplementation can prevent and reduce the risk of age-related macular degeneration (AMD) and other ocular disease, but until now, there has been no validated and well-characterized mouse model which can be employed to investigate the protective mechanism and relevant metabolism of retinal carotenoids. ß-Carotene oxygenases 1 and 2 (BCO1 and BCO2) are the only two carotenoid cleavage enzymes found in animals. Mutations of the bco2 gene may cause accumulation of xanthophyll carotenoids in animal tissues, and BCO1 is involved in regulation of the intestinal absorption of carotenoids. To determine whether or not mice deficient in BCO1 and/or BCO2 can serve as a macular pigment mouse model, we investigated the retinal accumulation of carotenoids in these mice when fed with zeaxanthin, lutein, or ß-carotene using an optimized carotenoid feeding method. HPLC analysis revealed that all three carotenoids were detected in sera, livers, retinal pigment epithelium (RPE)/choroids, and retinas of all of the mice, except that no carotenoid was detectable in the retinas of wild type (WT) mice. Significantly higher amounts of zeaxanthin and lutein accumulated in the retinas of BCO2 knockout (bco2-/-) mice and BCO1/BCO2 double knockout (bco1-/-/bco2-/-) mice relative to BCO1 knockout (bco1-/-) mice, while bco1-/- mice preferred to take up ß-carotene. The levels of zeaxanthin and lutein were higher than ß-carotene levels in the bco1-/-/bco2-/- retina, consistent with preferential uptake of xanthophyll carotenoids by retina. Oxidative metabolites were detected in mice fed with lutein or zeaxanthin but not in mice fed with ß-carotene. These results indicate that bco2-/- and bco1-/-/bco2-/- mice could serve as reasonable non-primate models for macular pigment function in the vertebrate eye, while bco1-/- mice may be more useful for studies related to ß-carotene.

Protein-Flavonoid Interaction Studies by a Taylor Dispersion Surface Plasmon Resonance (SPR) Technique: A Novel Method to Assess Biomolecular Interactions.

Flavonoids are common polyphenolic compounds widely distributed in fruits and vegetables. These pigments have important pharmacological relevance because emerging research suggests possible anti-cancer and anti-inflammatory properties as well other beneficial health effects. These compounds are relatively hydrophobic molecules, suggesting the role of blood transport proteins in their delivery to tissues. In this study, we assess the binding interactions of four flavonoids (kaempferol, luteolin, quercetin, and resveratrol) with human serum albumin (HSA), the most abundant protein in the blood, and with glutathione S-transferase pi isoform-1 (GSTP1), an enzyme with well-characterized hydrophobic binding sites that plays an important role in detoxification of xenobiotics with reduced glutathione, using a novel Taylor dispersion surface plasmon resonance (SPR) technique. For the first time, HSA sites revealed a high-affinity binding site for flavonoid interactions. Out of the four flavonoids that we examined, quercetin and kaempferol showed the strongest equilibrium binding affinities (K(D)) of 63 ± 0.03 nM and 37 ± 0.07 nM, respectively. GSTP1 displayed lower affinities in the micromolar range towards all of the flavonoids tested. The interactions of flavonoids with HSA and GSTP1 were studied successfully using this novel SPR assay method. The new method is compatible with both kinetic and equilibrium analyses.

Inactivity of human ß,ß-carotene-9',10'-dioxygenase (BCO2) underlies retinal accumulation of the human macular carotenoid pigment.

The macula of the primate retina uniquely concentrates high amounts of the xanthophyll carotenoids lutein, zeaxanthin, and meso-zeaxanthin, but the underlying biochemical mechanisms for this spatial- and species-specific localization have not been fully elucidated. For example, despite abundant retinal levels in mice and primates of a binding protein for zeaxanthin and meso-zeaxanthin, the pi isoform of glutathione S-transferase (GSTP1), only human and monkey retinas naturally contain detectable levels of these carotenoids. We therefore investigated whether or not differences in expression, localization, and activity between mouse and primate carotenoid metabolic enzymes could account for this species-specific difference in retinal accumulation. We focused on ß,ß-carotene-9',10'-dioxygenase (BCO2, also known as BCDO2), the only known mammalian xanthophyll cleavage enzyme. RT-PCR, Western blot analysis, and immunohistochemistry (IHC) confirmed that BCO2 is expressed in both mouse and primate retinas. Cotransfection of expression plasmids of human or mouse BCO2 into Escherichia coli strains engineered to produce zeaxanthin demonstrated that only mouse BCO2 is an active zeaxanthin cleavage enzyme. Surface plasmon resonance (SPR) binding studies showed that the binding affinities between human BCO2 and lutein, zeaxanthin, and meso-zeaxanthin are 10- to 40-fold weaker than those for mouse BCO2, implying that ineffective capture of carotenoids by human BCO2 prevents cleavage of xanthophyll carotenoids. Moreover, BCO2 knockout mice, unlike WT mice, accumulate zeaxanthin in their retinas. Our results provide a novel explanation for how primates uniquely concentrate xanthophyll carotenoids at high levels in retinal tissue.

Carotenoids as possible interphotoreceptor retinoid-binding protein (IRBP) ligands: a surface plasmon resonance (SPR) based study.

Uptake, transport and stabilization of xanthophylls in the human retina are important components of a complex multistep process that culminates in a non-uniform distribution of these important nutrients in the retina. The process is far from understood; here, we consider the potential role of interphotoreceptor retinoid-binding protein (IRBP) in this process. IRBP is thought to facilitate the exchange of 11-cis-retinal, 11-cis-retinol and all-trans-retinol between the retinal pigment epithelium (RPE), photoreceptors and Müller cells in the visual cycle. Structural and biochemical studies suggest that IRBP has a variety of nonequivalent ligand binding sites that function in this process. IRBP is multifunctional, being able to bind a variety of physiologically significant molecules including fatty acids in the subretinal space. This wide range of binding activities is of particular interest because it is unknown whether the lutein and zeaxanthin found in the macula originate from the choroidal or retinal circulations. If from the choroidal circulation, then IRBP is a likely mediator for their transport across the interphotoreceptor matrix. In this report, we explore the binding interactions of retinoids, fatty acids, and carotenoids with IRBP using surface plasmon resonance (SPR)-based biosensors. IRBP showed similar affinity toward retinoids and carotenoids (1-2 µM), while fatty acids had approximately 10 times less affinity. These results suggest that further studies should be carried out to evaluate whether IRBP has a physiologically relevant role in binding lutein and zeaxanthin in the interphotoreceptor matrix.