A Dual-layer Detector for Simultaneous Fluoroscopic and Nuclear Imaging

Purpose To develop and evaluate a dual-layer detector capable of acquiring intrinsically registered real-time fluoroscopic and nuclear images in the interventional radiology suite. Materials and Methods The dual-layer detector consists of an x-ray flat panel detector placed in front of a γ camera with cone beam collimator focused at the x-ray focal spot. This design relies on the x-ray detector absorbing the majority of the x-rays while it is more transparent to the higher energy γ photons. A prototype was built and dynamic phantom images were acquired. In addition, spatial resolution and system sensitivity (evaluated as counts detected within the energy window per second per megabecquerel) were measured with the prototype. Monte Carlo simulations for an improved system with varying flat panel compositions were performed to assess potential spatial resolution and system sensitivity. Results Experiments with the dual-layer detector prototype showed that spatial resolution of the nuclear images was unaffected by the addition of the flat panel (full width at half maximum, 13.6 mm at 15 cm from the collimator surface). However, addition of the flat panel lowered system sensitivity by 45%-60% because of the nonoptimized transmission of the flat panel. Simulations showed that an attenuation of 27%-35% of the γ rays in the flat panel could be achieved by decreasing the crystal thickness and housing attenuation of the flat panel. Conclusion A dual-layer detector was capable of acquiring real-time intrinsically registered hybrid images, which could aid interventional procedures involving radionuclides. Published under a CC BY-NC-ND 4.0 license. Online supplemental material is available for this article

Good performance of p16/ki-67 dual-stained cytology for surveillance of women treated for high-grade CIN

Women treated for high-grade cervical intraepithelial neoplasia (CIN) are at risk of recurrent CIN Grade 2 or worse (rCIN2+). Currently, posttreatment monitoring is performed using cytology or cytology/high-risk (hr)HPV cotesting. This study aimed to evaluate the performance of p16/Ki-67 dual-stained cytology (p16/Ki-67) for posttreatment monitoring. Three hundred and twenty-three women treated for high-grade CIN in the SIMONATH study underwent close surveillance by cytology, hrHPV and DNA methylation marker testing up to 12 months posttreatment. Histological endpoints were ascertained by colposcopy with biopsy at 6 and/or 12 months. p16/Ki-67 dual-staining was performed on residual liquid-based cytology samples obtained at, or shortly before biopsy collection. Clinical performance estimates of cytology, hrHPV, p16/Ki-67 testing and combinations thereof for the detection of rCIN2+ were determined and compared to each other. Sensitivity of p16/Ki-67 for rCIN2+ (69.2%) was nonsignificantly lower than that of cytology (82.1%; ratio 0.84, 95% CI: 0.71-1.01), but significantly lower than that of hrHPV testing (84.6%; ratio 0.82, 95% CI: 0.68-0.99). Specificity of p16/Ki-67 for rCIN2+ (90.4%) was significantly higher compared to both cytology (70.8%; ratio 1.28, 95% CI: 1.19-1.37) and hrHPV testing (76.2%; ratio 1.19, 95% CI: 1.12-1.26). Overall, hrHPV testing showed very high sensitivity, along with a good specificity. When considering cotesting, combined p16/Ki-67/hrHPV testing showed rCIN2+ sensitivity comparable to cytology/hrHPV cotesting (87.2% vs. 89.7%; ratio 0.97, 95% CI: 0.92-1.03), but with significantly increased specificity (74.2% vs. 58.1%; ratio 1.28, 95% CI: 1.19-1.38). Thus, when considered in combination with hrHPV, p16/Ki-67 might be an attractive approach for surveillance of women treated for high-grade CIN

Classification of high-grade cervical intraepithelial neoplasia by p16ink4a, Ki-67, HPV E4 and FAM19A4/miR124-2 methylation status demonstrates considerable heterogeneity with potential consequences for management

High-grade cervical intraepithelial neoplasia (CIN2 and CIN3) represents a heterogeneous disease with varying cancer progression risks. Biomarkers indicative for a productive human papillomavirus (HPV) infection (HPV E4) and a transforming HPV infection (p16 ink4a, Ki-67 and host-cell DNA methylation) could provide guidance for clinical management in women with high-grade CIN. This study evaluates the cumulative score of immunohistochemical expression of p16 ink4a (Scores 0-3) and Ki-67 (Scores 0-3), referred to as the “immunoscore” (IS), in 262 CIN2 and 235 CIN3 lesions derived from five European cohorts in relation to immunohistochemical HPV E4 expression and FAM19A4/miR124-2 methylation in the corresponding cervical scrape. The immunoscore classification resulted in 30 lesions within IS group 0-2 (6.0%), 151 lesions within IS group 3-4 (30.4%) and 316 lesions within IS group 5-6 (63.6%). E4 expression decreased significantly from CIN2 to CIN3 (P <.001) and with increasing immunoscore group (P trend <.001). Methylation positivity increased significantly from CIN2 to CIN3 (P <.001) and with increasing immunoscore group (P trend <.001). E4 expression was present in 9.8% of CIN3 (23/235) and in 12.0% of IS group 5-6 (38/316). Notably, in a minority (43/497, 8.7%) of high-grade lesions, characteristics of both transforming HPV infection (DNA hypermethylation) and productive HPV infection (E4 expression) were found simultaneously. Next, we stratified all high-grade CIN lesions, based on the presumed cancer progression risk of the biomarkers used, into biomarker profiles. These biomarker profiles, including immunoscore and methylation status, could help the clinician in the decision for immediate treatment or a “wait and see” policy to reduce overtreatment of high-grade CIN lesions

N-Glycosylation Defects in Humans Lower Low-Density Lipoprotein Cholesterol Through Increased Low-Density Lipoprotein Receptor Expression

BACKGROUND: The importance of protein glycosylation in regulating lipid metabolism is becoming increasingly apparent. We set out to further investigate this by studying patients with type I congenital disorders of glycosylation (CDGs) with defective N-glycosylation. METHODS: We studied 29 patients with the 2 most prevalent types of type I CDG, ALG6 (asparagine-linked glycosylation protein 6)-deficiency CDG and PMM2 (phosphomannomutase 2)-deficiency CDG, and 23 first- and second-degree relatives with a heterozygous mutation and measured plasma cholesterol levels. Low-density lipoprotein (LDL) metabolism was studied in 3 cell models-gene silencing in HepG2 cells, patient fibroblasts, and patient hepatocyte-like cells derived from induced pluripotent stem cells-by measuring apolipoprotein B production and secretion, LDL receptor expression and membrane abundance, and LDL particle uptake. Furthermore, SREBP2 (sterol regulatory element-binding protein 2) protein expression and activation and endoplasmic reticulum stress markers were studied. RESULTS: We report hypobetalipoproteinemia (LDL cholesterol [LDL-C] and apolipoprotein B below the fifth percentile) in a large cohort of patients with type I CDG (mean age, 9 years), together with reduced LDL-C and apolipoprotein B in clinically unaffected heterozygous relatives (mean age, 46 years), compared with 2 separate sets of age- and sex-matched control subjects. ALG6 and PMM2 deficiency led to markedly increased LDL uptake as a result of increased cell surface LDL receptor abundance. Mechanistically, this outcome was driven by increased SREBP2 protein expression accompanied by amplified target gene expression, resulting in higher LDL receptor protein levels. Endoplasmic reticulum stress was not found to be a major mediator. CONCLUSIONS: Our study establishes N-glycosylation as an important regulator of LDL metabolism. Given that LDL-C was also reduced in a group of clinically unaffected heterozygotes, we propose that increasing LDL receptor-mediated cholesterol clearance by targeting N-glycosylation in the LDL pathway may represent a novel therapeutic strategy to reduce LDL-C and cardiovascular disease

N-Glycosylation Defects in Humans Lower Low-Density Lipoprotein Cholesterol Through Increased Low-Density Lipoprotein Receptor Expression

Background: The importance of protein glycosylation in regulating lipid metabolism is becoming increasingly apparent. We set out to further investigate this by studying patients with type I congenital disorders of glycosylation (CDGs) with defective N-glycosylation. Methods: We studied 29 patients with the 2 most prevalent types of type I CDG, ALG6 (asparagine-linked glycosylation protein 6)-deficiency CDG and PMM2 (phosphomannomutase 2)-deficiency CDG, and 23 first- and second-degree relatives with a heterozygous mutation and measured plasma cholesterol levels. Low-density lipoprotein (LDL) metabolism was studied in 3 cell models-gene silencing in HepG2 cells, patient fibroblasts, and patient hepatocyte-like cells derived from induced pluripotent stem cells-by measuring apolipoprotein B production and secretion, LDL receptor expression and membrane abundance, and LDL particle uptake. Furthermore, SREBP2 (sterol regulatory element-binding protein 2) protein expression and activation and endoplasmic reticulum stress markers were studied. Results: We report hypobetalipoproteinemia (LDL cholesterol [LDL-C] and apolipoprotein B below the fifth percentile) in a large cohort of patients with type I CDG (mean age, 9 years), together with reduced LDL-C and apolipoprotein B in clinically unaffected heterozygous relatives (mean age, 46 years), compared with 2 separate sets of age- and sex-matched control subjects. ALG6 and PMM2 deficiency led to markedly increased LDL uptake as a result of increased cell surface LDL receptor abundance. Mechanistically, this outcome was driven by increased SREBP2 protein expression accompanied by amplified target gene expression, resulting in higher LDL receptor protein levels. Endoplasmic reticulum stress was not found to be a major mediator. Conclusions: Our study establishes N-glycosylation as an important regulator of LDL metabolism. Given that LDL-C was also reduced in a group of clinically unaffected heterozygotes, we propose that increasing LDL receptor-mediated cholesterol clearance by targeting N-glycosylation in the LDL pathway may represent a novel therapeutic strategy to reduce LDL-C and cardiovascular disease

FAM19A4 methylation analysis in self-samples compared with cervical scrapes for detecting cervical (pre)cancer in HPV-positive women

BACKGROUND: High-risk human papillomavirus (hrHPV)-positive women require triage to identify those with cervical high-grade intraepithelial neoplasia and cancer (⩾CIN3 (cervical intraepithelial neoplasia grade 3)). FAM19A4 methylation analysis, which detects advanced CIN and cancer, is applicable to different sample types. However, studies comparing the performance of FAM19A4 methylation analysis in hrHPV-positive self-samples and paired physician-taken scrapes are lacking. METHODS: We compared the performance of FAM19A4 methylation analysis (and/or HPV16/18 genotyping) in self-samples and paired physician-taken scrapes for ⩾CIN3 detection in hrHPV-positive women (n=450,18–66 years). RESULTS: Overall FAM19A4 methylation levels between sample types were significantly correlated, with strongest correlation in women with ⩾CIN3 (Spearman's ρ 0.697, P<0.001). The performance of FAM19A4 methylation analysis and/or HPV16/18 genotyping did not differ significantly between sample types. In women ⩾30 years, ⩾CIN3 sensitivity of FAM19A4 methylation analysis was 78.4% in self-samples and 88.2% in scrapes (ratio 0.89; CI: 0.75–1.05). In women <30 years, ⩾CIN3 sensitivities were 37.5% and 45.8%, respectively (ratio 0.82; CI: 0.55–1.21). In both groups, ⩾CIN3 specificity of FAM19A4 methylation analysis was significantly higher in self-samples compared with scrapes. CONCLUSIONS: FAM19A4 methylation analysis in hrHPV-positive self-samples had a slightly lower sensitivity and a higher specificity for ⩾CIN3 compared with paired physician-taken scrapes. With a similarly good clinical performance in both sample types, combined FAM19A4 methylation analysis and HPV16/18 genotyping provides a feasible triage strategy for hrHPV-positive women, with direct applicability on self-samples