A technique to quantify very low activities in regions of interest with a collimatorless detector

We present a new method to measure sub-microcurie activities of photon-emitting radionuclides in organs and lesions of small animals in vivo. Our technique, named the collimator-less likelihood fit, combines a very high sensitivity collimatorless detector with a Monte Carlo-based likelihood fit in order to estimate the activities in previously segmented regions of interest along with their uncertainties. This is done directly from the photon projections in our collimatorless detector and from the region of interest segmentation provided by an x-ray computed tomography scan. We have extensively validated our approach with 225Ac experimentally in spherical phantoms and mouse phantoms, and also numerically with simulations of a realistic mouse anatomy. Our method yields statistically unbiased results with uncertainties smaller than 20% for activities as low as ~111 Bq (3 nCi) and for exposures under 30 minutes. We demonstrate that our method yields more robust recovery coefficients when compared to SPECT imaging with a commercial pre-clinical scanner, specially at very low activities. Thus, our technique is complementary to traditional SPECT/CT imaging since it provides a more accurate and precise organ and tumor dosimetry, with a more limited spatial information. Finally, our technique is specially significant in extremely low-activity scenarios when SPECT/CT imaging is simply not viable.

Dosimetry Reconstruction in Radiopharmaceutical Therapy Using a Sparse Network of External γ-Sensors

PURPOSE/OBJECTIVE(S)

Radiopharmaceutical therapy (RPT) has demonstrated promise in the treatment of neuroendocrine and prostate cancer. Due to the highly varied biodistribution and non-homogeneity of total integrated dose across cancer patients, a system for real-time dosimetry based on continuous measurement is desirable to deliver sufficient dose for tumor ablation while preventing toxicity from off-target uptake by organs at risk (OAR). Single time point imaging (mostly SPECT)-based dosimetry offers a snapshot of the body-wide dose distribution at a given time point, but even single SPECT imaging is generally limited in availability, often leading to significant inaccuracies in estimating total integrated dose. Therefore, accurate personalized dosimetry in RPT is an unmet need and requires continuous dosimetry measurements of tumors and OARs across multiple half-lives of the therapeutic radiopharmaceutical. Using a priori knowledge of tumor and OAR locations from pretherapy imaging, we have developed a novel algorithm that utilizes a network of custom uncollimated, optical fiber-based γ-counting probes to isolate the real-time in vivo tumor and OAR uptake in 177Lu-PSMA-617 and 225Ac-MACROPA-YS5 therapy.

MATERIALS/METHODS

The proposed system was successfully validated in athymic mice models bearing varying numbers of tumors from two human prostate cancer cell lines (PC3-pip, PC3-flu). Uncollimated γ counts using the developed probes were acquired outside of the mice for 10 minutes, starting at 0 hr, 6 hrs, 12 hrs, 24 hrs, and 48 hrs after the injection of 177Lu-PSMA-617. The percent injected activity per mL of tissue (%IA/mL) of each tumor and OAR was reconstructed at every time point and compared to the %IA/mL extracted from SPECT/CT immediately after the recording.

RESULTS

The developed system's %IA/mL reconstruction in PC3-pip tumors, PC3-flu tumors, kidneys, and bladders is highly correlative with the %IA/mL extracted from state-of-art in vivo dosimetry techniques, with %IA/mL ranging from 0.1% to 160% assuming a 29.6 MBq 177Lu-PSMA-617 administration. The least squares linear regression fit between the reconstructed activity and the activity measured from SPECT/CT is given by Estimated %IA/mL = 0.91 x SPECT %IA/mL, with an R2 of 0.991, and Pearson's r of 0.9975. There is a nearly 1:1 mapping between the proposed model and SPECT/CT.

CONCLUSION

A novel dose reconstruction algorithm for personalized dosimetry in RPT that utilizes a sparse set of external γ-counters and a priori knowledge of tumor and OAR locations was developed and validated in in vivo human prostate cancer murine models. The proposed system enables continuous dosimetry measurements of multiple tumors and OAR noninvasively, with high accessibility, high temporal resolution, and across multiple classes of ɑ and β-based RPT. Similar experiments using 225Ac-MACROPA-YS5 are ongoing and additional results will be reported.

Brain lipidomics: From functional landscape to clinical significance

Lipids are crucial components of cellular function owing to their role in membrane formation, intercellular signaling, energy storage, and homeostasis maintenance. In the brain, lipid dysregulations have been associated with the etiology and progression of neurodegeneration and other neurological pathologies. Hence, brain lipids are emerging as important potential targets for the early diagnosis and prognosis of neurological diseases. This review aims to highlight the significance and usefulness of lipidomics in diagnosing and treating brain diseases. We explored lipid alterations associated with brain diseases, paying attention to organ-specific characteristics and the functions of brain lipids. As the recent advances in brain lipidomics would have been impossible without advances in analytical techniques, we provide up-to-date information on mass spectrometric approaches and integrative analysis with other omic approaches. Last, we present the potential applications of lipidomics combined with artificial intelligence techniques and interdisciplinary collaborative research for treating brain diseases with clinical heterogeneities.

Application of Proteomics in Cancer: Recent Trends and Approaches for Biomarkers Discovery

Proteomics has become an important field in molecular sciences, as it provides valuable information on the identity, expression levels, and modification of proteins. For example, cancer proteomics unraveled key information in mechanistic studies on tumor growth and metastasis, which has contributed to the identification of clinically applicable biomarkers as well as therapeutic targets. Several cancer proteome databases have been established and are being shared worldwide. Importantly, the integration of proteomics studies with other omics is providing extensive data related to molecular mechanisms and target modulators. These data may be analyzed and processed through bioinformatic pipelines to obtain useful information. The purpose of this review is to provide an overview of cancer proteomics and recent advances in proteomic techniques. In particular, we aim to offer insights into current proteomics studies of brain cancer, in which proteomic applications are in a relatively early stage. This review covers applications of proteomics from the discovery of biomarkers to the characterization of molecular mechanisms through advances in technology. Moreover, it addresses global trends in proteomics approaches for translational research. As a core method in translational research, the continued development of this field is expected to provide valuable information at a scale beyond that previously seen.

Fermented milk with Lactobacillus curvatus SMFM2016-NK alleviates periodontal and gut inflammation, and alters oral and gut microbiota

This study aimed to analyze the effect of milk fermented with Lactobacillus curvatus SMFM2016-NK on periodontal diseases and gut health in a rat model. To improve the effect of Lb. curvatus SMFM2016-NK-fermented milk administration for relieving periodontitis, the periodontitis rat models were treated with the following for 4 wk: 10% skim milk (normal), periodontitis + 10% skim milk (negative control), periodontitis + Lactobacillus rhamnosus GG-fermented milk (positive control), and periodontitis + Lb. curvatus SMFM2016-NK-fermented milk (PD+LCFM). Transcriptional analysis of inflammatory cytokines [tumor necrosis factor α (TNF-α), IL-1β, IL-6, and IL-10] was performed via quantitative reverse-transcription PCR. The changes in the oral and gut microbiomes after administering Lb. curvatus SMFM2016-NK-fermented milk were analyzed with metagenomics sequencing using DNA extracted from the oral gingival tissues and feces from the cecum of the rat models. After treatment with Lb. curvatus SMFM2016-NK-fermented milk, the relative gene expression levels of TNFA and IL1B in the gingiva decreased in the PD+LCFM group compared with those in the negative control group. In the oral microbiome, the proportion of the phylum Proteobacteria in the PD+LCFM group was lower than that in the negative control after treatment with Lb. curvatus SMFM2016-NK-fermented milk. For the effect in the gut, the relative gene expression levels of inflammatory cytokines in the colon between the normal and negative control groups were not different; however, the expression levels of TNFA and IL1B in the PD+LCFM and positive control groups, respectively, were lower than those in the negative control group. The composition and diversity of the gut microbiome differed among normal, periodontitis, and Lb. curvatus SMFM2016-NK-fermented milk treatment groups. These results indicate that Lb. curvatus SMFM2016-NK-fermented milk could alleviate periodontal and gut inflammation and change oral and gut microbiota.

Subepithelial neutrophil infiltration as a predictor of the surgical outcome of chronic rhinosinusitis with nasal polyps

BACKGROUND

Neutrophils present as major inflammatory cells in refractory chronic rhinosinusitis with nasal polyps (CRSwNP), regardless of the endotype. However, their role in the pathophysiology of CRSwNP remains poorly understood. We investigated factors predicting the surgical outcomes of CRSwNP patients with focus on neutrophilic localization.

METHODS

We employed machine-learning methods such as the decision tree and random forest models to predict the surgical outcomes of CRSwNP. Immunofluorescence analysis was conducted to detect human neutrophil elastase (HNE), Bcl-2, and Ki-67 in NP tissues. We counted the immunofluorescence-positive cells and divided them into three groups based on the infiltrated area, namely, epithelial, subepithelial, and perivascular groups.

RESULTS

On machine learning, the decision tree algorithm demonstrated that the number of subepithelial HNE-positive cells, Lund-Mackay (LM) scores, and endotype (eosinophilic or non-eosinophilic) were the most important predictors of surgical outcomes in CRSwNP patients. Additionally, the random forest algorithm showed that, after ranking the mean decrease in the Gini index or the accuracy of each factor, the top three ranking factors associated with surgical outcomes were the LM score, age, and number of subepithelial HNE-positive cells. In terms of cellular proliferation, immunofluorescence analysis revealed that Ki-67/HNE-double positive and Bcl-2/HNE-double positive cells were significantly increased in the subepithelial area in refractory CRSwNP.

CONCLUSION

Our machine-learning approach and immunofluorescence analysis demonstrated that subepithelial neutrophils in NP tissues had a high expression of Ki-67 and could serve as a cellular biomarker for predicting surgical outcomes in CRSwNP patients.

Engineered ionizable lipid nanoparticles for targeted delivery of RNA therapeutics into different types of cells in the liver

Ionizable lipid nanoparticles (LNPs) have been widely used for in vivo delivery of RNA therapeutics into the liver. However, a main challenge remains to develop LNP formulations for selective delivery of RNA into certain types of liver cells, such as hepatocytes and liver sinusoidal endothelial cells (LSECs). Here, we report the engineered LNPs for the targeted delivery of RNA into hepatocytes and LSECs. The effects of particle size and polyethylene glycol-lipid content in the LNPs were evaluated for the hepatocyte-specific delivery of mRNA by ApoE-mediated cellular uptake through low-density lipoprotein receptors. Targeted delivery of RNA to LSECs was further investigated using active ligands. Incorporation of mannose allowed the selective delivery of RNA to LSECs, while minimizing the unwanted cellular uptake by hepatocytes. These results demonstrate that engineered LNPs have great potential for the cell type-specific delivery of RNA into the liver and other tissues.

In-Depth Glycan Characterization of Therapeutic Glycoproteins by Stepwise PGC SPE and LC-MS/MS

Glycosylation of biologics, an important factor in pharmacological functions such as efficacy, safety, and biological activity, is easily affected by subtle changes in the cellular environment. Therefore, comprehensive and in-depth glycan characterization of therapeutic glycoproteins should be performed to ensure product quality and process consistency, but it is analytically challenging due to glycan microheterogeneity occurring in the glycan biosynthesis pathway. LC-based chromatographic separation combined with mass spectrometry (MS) has been widely used as a prominent tool for the qualitative and quantitative analysis of glycosylation of therapeutic glycoproteins. However, prior to LC/MS analysis, glycans are selectively captured and fractionated by solid-phase extraction (SPE) utilizing physicochemical characteristics for comprehensive characterization of a wide range of glycan heterogeneity on glycoengineered therapeutic proteins. In particular, porous graphitized carbon (PGC) SPE has been employed as a useful technique for the fractionation of native glycans having different sizes and polarities. Here, we describe a systematic method for comprehensive glycan characterization of therapeutic proteins using stepwise PGC SPE and LC/MS.

Clinical features, risk factors, and prognosis of anthracycline-induced cardiotoxicity in patients with malignant lymphoma who received a CHOP like regimen

Background

Anthracycline-induced cardiotoxicity is a serious complication in patients with malignant lymphoma (ML) who received chemotherapy, which threatens life prognosis and quality of life of patients. However, incidence and risk factors of cardiotoxicity in patients with ML who undergo intensive chemotherapy which aims complete remission is not clarified. Furthermore, prognosis after cardiotoxicity and that after recovery from cardiotoxicity have not been elucidated.

Method

We screened 443 ML patients who received either rituximab (R)-CHOP or CHOP regimen between January 2008 and December 2017 at Nagoya City University Hospital. Two handled forty-four patients who underwent echocardiography before and after chemotherapy were enrolled and data were analyzed retrospectively. Cardiotoxicity was defined as a decline in left ventricular ejection fraction (LVEF) of 10% or greater and an LVEF was below 50%. Partial recovery was defined as a 5% or more of increase in LVEF and an LVEF was ≥50% after cardiotoxicity. Complete recovery was defined as an increase in LVEF became more than 95% of the baseline value. Patient's basic characteristics, chemotherapeutic regimen, laboratory data, echocardiographic data, and prognosis were collected from the medical records by two cardiologists and two hematologists.

Result

At baseline, the median age was 71 years, the median cumulative dose of doxorubicin was 302 mg/m2 and the median LVEF was 69%. During the follow-up period, cardiotoxicity was observed in 52 out of 244 patients (21%), 30 patients (12%) had a symptomatic heart failure, and 5 patients died from cardiovascular cause. Thirty-five patients developed cardiotoxicity during the first year of chemotherapy. Multivariate analysis identified that only the baseline LVEF (HR 0.949, 95% CI 0.919–0.981, p=0.002) was an independent risk factor for cardiotoxicity. In our study, patients who received more than 200 mg/m2 of doxorubicin developed cardiotoxicity frequently. Among 52 patients who experienced cardiotoxicity, partial recovery and full recovery were observed in 18 (35%) and 4 (8%) patients, respectively. Four patients without recovery died due to heart failure and 1 patient with partial recovery died suddenly. Six out of 18 patients with partial recovery developed re-cardiotoxicity.

Conclusion

ML patients who undergo more than 200 mg/m2 of doxorubicin need a watchful follow-up. Only a baseline LVEF was an independent risk factor for cardiotoxicity. one third of patients with partial recovery developed re-cardiotoxicity.

Funding Acknowledgement

Type of funding source: None

Diagnostic accuracy of left ventricular diastolic transverse strain imaging by speckle tracking echocardiography for diagnosing chest pain in diabetic patients

Background

Two-dimensional speckle tracking echocardiography (2D-STE) has been reported to be useful for the diagnosis of myocardial ischemia by detecting delayed relaxation (diastolic stunning) after an episode of angina. 2D-longitudinal strain is not specific besides ischemia such as diastolic dysfunction, and diabetes have been associated with abnormal longitudinal fibers. The aim is to evaluate the diagnostic accuracy of Left ventricular (LV) diastolic transverse strain imaging by STE to detect the presence of acute coronary syndrome (ACS) in diabetic patients with acute chest pain.

Methods

385 consecutive patients with acute chest pain and without wall motion abnormality, who were admitted to an emergency department (ED) at 1 of 12 clinical sites in Japan, were enrolled and underwent 2D-STE at ED. Left ventricular (LV) transverse strain values at aortic valve closure (A) and one-third of diastole duration (B) were measured. The strain imaging diastolic index (SI-DI) was value was determined as: (A − B)/A × 100% to assess the LV diastolic strain imaging and was used to identify the regional LV delayed relaxation. All patients underwent coronary CT or coronary angiography to establish the diagnosis of ACS. Clinicians were blinded to the 2D-STE results.

Results

Out of 385 patients, 2D-STE analysis was possible in 365 patients (94%). 76 patients were diabetic (DM+), and 289 patients were non-diabetic (DM-). With assessment of coronary CT or coronary angiography, ACS was diagnosed in 125 patients (34%). 2D-STE was obtained at a mean of 5.3 hours after chest pain episode. Transverse SI-DI of ischemic segments were significantly lower than those of non-ischemic segments (p value <0.001) in both diabetic and non-diabetic patients, and transverse SI-DI of both diabetic and non-diabetic patients demonstrated high area under curve (AUC) for detection of myocardial ischemia (Figure: RCA; right coronary artery, LAD; left anterior descending artery, LCX; left circumferencial artery). In diabetic patients, sensitivity, specificity, and negative predictive value for ACS of transverse SI-DI are 100%, 95%, 100% in RCA (a cut-off value of 36.2), and 86.4%, 95%, 93% in LAD (a cut-off value of 50.2), and 75%, 85%, 94% in LCX (a cut-off value of 52), respectively.

Conclusion

LV diastolic transverse strain imaging by 2D-STE at ED increase the sensitivity, specificity and accuracy to predict the presence of ACS in diabetic patients with chest pain, as well as non-diabetic patients. (UMIN000013859).

Figure 1. Transverse Strain (SI-DI): AUC (95% CI)

Funding Acknowledgement

Type of funding source: None

Arterial stiffness could reflect increased cardiac load and reduced pulmonary function in the general population

Background

Pulmonary function is known to decrease with age and reduced pulmonary function has been reported to be associated with all-cause mortality and cardiovascular death. The association between pulmonary impairment and atherosclerosis was reported previously but has not been investigated sufficiently in the general population.

Purpose

We hypothesized that arterial stiffness could reflect increase of cardiac load and reduced pulmonary function. The present study aimed to investigate whether increased cardiac load and reduced pulmonary function could affect arterial stiffness in the general population.

Methods

Subjects undergoing their health check-up were enrolled. Plasma B-type natriuretic peptide (BNP) levels and serum high-sensitivity cardiac troponin I (hs-cTnI) levels were measured to evaluate cardiac load and myocardial damage. Radial augmentation index (rAI) was measured to investigate arterial stiffness using HEM-9000AI device. Subjects with an ST-T segment abnormality on the electrocardiogram, renal insufficiency, cancer, active inflammatory disease, or a history of cardiovascular events and pulmonary disease were excluded. Pulmonary function was assessed using spirometry by calculating forced vital capacity (FVC) as a percentage of predicted value (FVC%-predicted), forced expiratory volume in 1 second (FEV1) as a percentage of predicted value (FEV1%-predicted), and the ratio of FEV1 to FVC (FEV1/FVC).

Results

A total of 1100 subjects aged 57 years were enrolled and their median values of BNP and hs-cTnI were 15.5 and 2.3 pg/ml. The levels of rAI were significantly associated with the levels of BNP after adjustment for possible confounders in multivariate regression analysis, but were not with the levels of hs-TnI. While the parameters of pulmonary function were inversely associated with the levels of rAI and hs-cTnI after adjustment for possible confounders in the multivariate regression analysis, but not with the levels of BNP. The other multivariate regression analyses where BNP, hs-cTnI, parameters of pulmonary function, and the other possible factors were simultaneously included as independent variables revealed that the BNP levels and the FVC%-predicted or FEV1%-predicted, besides age, gender, smoking status, body mass index, blood pressure, heart rate, creatinine, fasting plasma glucose, and triglyceride, were significantly associated with the levels of rAI.

Conclusions

The significant associations of rAI with BNP and pulmonary function were revealed in the general population. These findings support that arterial stiffness could reflect increased cardiac load and reduced pulmonary function, in apparently healthy individuals.

Funding Acknowledgement

Type of funding source: None

NIST Interlaboratory Study on Glycosylation Analysis of Monoclonal Antibodies: Comparison of Results from Diverse Analytical Methods

Glycosylation is a topic of intense current interest in the development of biopharmaceuticals because it is related to drug safety and efficacy. This work describes results of an interlaboratory study on the glycosylation of the Primary Sample (PS) of NISTmAb, a monoclonal antibody reference material. Seventy-six laboratories from industry, university, research, government, and hospital sectors in Europe, North America, Asia, and Australia submitted a total of 103 reports on glycan distributions. The principal objective of this study was to report and compare results for the full range of analytical methods presently used in the glycosylation analysis of mAbs. Therefore, participation was unrestricted, with laboratories choosing their own measurement techniques. Protein glycosylation was determined in various ways, including at the level of intact mAb, protein fragments, glycopeptides, or released glycans, using a wide variety of methods for derivatization, separation, identification, and quantification. Consequently, the diversity of results was enormous, with the number of glycan compositions identified by each laboratory ranging from 4 to 48. In total, one hundred sixteen glycan compositions were reported, of which 57 compositions could be assigned consensus abundance values. These consensus medians provide community-derived values for NISTmAb PS. Agreement with the consensus medians did not depend on the specific method or laboratory type. The study provides a view of the current state-of-the-art for biologic glycosylation measurement and suggests a clear need for harmonization of glycosylation analysis methods.

P743 Right ventricular function is important for exercise capacity in patients at risk of heart failure

Background and Purpose

It is important to evaluate exercise capacity to detect the development of heart failure (HF) in patients with heart disease. The pathology of exercise capacity is multi-factorial, and cardiac function is recognized as one of the most important determinants. However, the correlation between right ventricular (RV) function and exercise capacity is not fully understood in the subjects without HF. Therefore, we assessed the relationship between RV function and exercise capacity, both in patients with HF (HF+) and in patients with heart disease but not developed HF (HF-).

Methods

Two hundred and fifty-two patients with heart disease who underwent both Doppler echocardiography at rest and cardio-pulmonary exercise testing (CPET) for the assessment of heart function were enrolled (HF+: n = 142, HF-: n = 110). We measured left ventricular ejection fraction (LVEF), peak early diastolic transmitral flow velocity (E), peak late diastolic transmitral flow velocity (A), early diastolic mitral annular velocity (e’), left atrial volume (LAV), and tricuspid annular plane systolic excursion (TAPSE) by echocardiography. After echocardiographic examination, symptom-limited exercise testing was performed with simultaneous respiratory gas analysis, and peak oxygen consumption (pVO2) was determined. Blood examination including hemoglobin (Hb) and brain natriuretic peptide (BNP) was done on the same day.

Results

There were significant relationships between pVO2 and LVEF (r = 0.16, p = 0.005), e" (r = 0.51, p < 0.0001), E/e" (r=-0.47, p < 0.0001), LAV (r=-0.21, p = 0.0002), and TAPSE (r = 0.33, p < 0.0001) in the whole subjects. In the multiple regression analyses, age, Hb, E/e" and TAPSE were selected as significant determinants for pVO2 both in HF+ (R²=0.39, p < 0.0001) and HF- (R²=0.33, p < 0.0001).

Conclusion

RV function is the prime determinant of exercise capacity in patients at risk of HF, as well as in patients with HF.

Abstract P743 Figure.

1225 Diagnostic accuracy of left ventricular diastolic strain imaging by speckle tracking echocardiography in detecting ischemic etiology of acute chest pain

Funding Acknowledgements

none

OnBehalf

A TRAC-SI Multicenter Trial

Background

Two-dimensional speckle tracking echocardiography (2D-STE) has been reported to be useful for the diagnosis of myocardial ischemia by detecting delay in regional myocardial expansion (diastolic stunning) up to many hours after an episode of angina. The aim is to evaluate the diagnostic accuracy of Left ventricular (LV) diastolic longitudinal, circumferential, transverse and radial strain imaging by STE to detect the presence of acute coronary syndrome (ACS) in patients with acute chest pain.

Methods

388 consecutive patients with acute chest pain and without wall motion abnormality, who were admitted to an emergency department (ED) at 1 of 12 clinical sites in Japan, were enrolled and underwent 2D-STE at ED. Left ventricular (LV) longitudinal, circumferential, transverse and radial strain values at aortic valve closure (A) and one-third of diastole duration (B) were measured. The strain imaging diastolic index (SI-DI) was value was determined as: (A-B)/A × 100% to assess the LV diastolic strain imaging and was used to identify the regional LV delayed relaxation. All patients underwent coronary CT or coronary angiography to establish the diagnosis of ACS. Clinicians were blinded to the 2D-STE results.

Results

Out of 388 patients, 2D-STE analysis was possible in 358 patients (92%). With assessment of coronary CT or coronary angiography, ACS was diagnosed in 118 patients (33%). 2D-STE was obtained at a mean of 5.3 hours after chest pain episode. SI-DI of longitudinal, circumferential, transverse and radial strain of ischemic segments were significantly lower than those of non-ischemic segments (p value < 0.001), and transverse and radial SI-DI demonstrated high diagnostic accuracy, compared with longitudinal SI-DI (Figure 1). Sensitivity, specificity, and negative predictive value for ACS of transverse SI-DI are 87%, 88%, % and 95%, respectively, using a cut-off value of 63.3.

Conclusion

LV diastolic strain imaging by 2D-STE at ED increase the sensitivity, specificity and accuracy to predict the presence of ACS in patients with chest pain. Compared with longitudinal diastolic strain imaging, transverse diastolic strain imaging is more sensitive marker to detect the myocardial ischemic episode (UMIN000013859).

Abstract 1225 Figure 1

A Case Series of Asymptomatic Hemodialysis Catheter-Related Right Atrial Thrombi That Are Incidentally Detected Prior to Kidney Transplantation

A hemodialysis (HD) catheter-related right atrial thrombus (RAT) is rarely encountered prior to kidney transplantation (KT) but necessitates a decision about whether to anticoagulate and/or delay the surgery. There is controversy surrounding the clinical implications of a RAT in this situation. It is sometimes considered fatal but other opinions consider it to be benign, especially when incidentally detected. We reviewed the clinical characteristics, management, and outcomes of a patient series with HD catheter-related RAT detected prior to KT and speculated on its clinical significance. Among 3677 cases of KT performed on 3607 patients between January 1997 and September 2015 in our single tertiary center, 11 cases of HD catheter-related RAT detected on transthoracic echocardiography (TTE) prior to KT were included for analysis. The average maximal diameter of the RAT was 23.2 ± 16.3 (SD in mm) and 9 (81.8%) of these 11 patients had no symptoms associated with the RAT. Four patients (36.3%) had their catheters replaced, 5 patients (45.5%) had their catheters removed, and the catheters were maintained in the remaining 2 patients (18.2%). Six patients (54.5%) were anticoagulated with either heparin or warfarin. However all 11 patients had a successful KT suggesting that a HD catheter-related RAT incidentally detected prior to this surgery may not be as serious as previously considered and should not be a reason for delaying the transplantation.

Brain somatic mutations in SLC35A2 cause intractable epilepsy with aberrant N-glycosylation

OBJECTIVE

To identify whether somatic mutations in SLC35A2 alter N-glycan structures in human brain tissues and cause nonlesional focal epilepsy (NLFE) or mild malformation of cortical development (mMCD).

METHODS

Deep whole exome and targeted sequencing analyses were conducted for matched brain and blood tissues from patients with intractable NLFE and patients with mMCD who are negative for mutations in mTOR pathway genes. Furthermore, tissue glyco-capture and nanoLC/mass spectrometry analysis were performed to examine N-glycosylation in affected brain tissue.

RESULTS

Six of the 31 (19.3%) study patients exhibited brain-only mutations in SLC35A2 (mostly nonsense and splicing site mutations) encoding a uridine diphosphate (UDP)-galactose transporter. Glycome analysis revealed the presence of an aberrant N-glycan series, including high degrees of N-acetylglucosamine, in brain tissues with SLC35A2 mutations.

CONCLUSION

Our study suggests that brain somatic mutations in SLC35A2 cause intractable focal epilepsy with NLFE or mMCD via aberrant N-glycosylation in the affected brain.

Multi-paratopic VEGF decoy receptor have superior anti-tumor effects through anti-EGFRs and targeted anti-angiogenic activities

Limitation of current anti-Vascular Endothelial Growth Factor (VEGF) cancer therapy is transitory responses, inevitable relapses and its insufficient tumor-targeting. Thus, multifaceted approaches, including the development of bispecific antibodies and combination strategies targeting different pathways have been proposed as an alternative. Here, we developed a novel multi-paratopic VEGF decoy receptor, Cetuximab-VEGF-Grab and Trastuzumab-VEGF-Grab, by genetically fusing VEGF decoy receptor (VEGF-Grab) to a single chain Fv of anti-Epidermal Growth Factor Receptor (EGFR) antibody (Cetuximab and Trastuzumab). These multi-paratopic VEGF decoy receptor, which recognize VEGF and EGFR family (EGFR or HER2), effectively suppressed both VEGF and EGFR pathways in vitro, to levels similar to those of the parental VEGF-Grab and anti-EGFR antibodies. In addition, the concurrent binding of multi-paratopic VEGF decoy receptor to VEGF and EGFR family enabled their specific localization to EGFR + tumor in vitro and in vivo. Furthermore, Cetuximab-VEGF-Grab and Trastuzumab-VEGF-Grab exhibited the enhanced anti-tumor activities compared to VEGF-Grab in EGFR + tumor xenograft mouse model via anti-EGFR and the targeted anti-angiogenic activities. These results indicate that multi-paratopic VEGF decoy receptor can be a promising agent, combining tumor-targeted anti-angiogenic therapy with efficient blockade of proliferative signals mediated by EGFR family.

Effect of topical loteprednol etabonate with lid hygiene on tear cytokines and meibomian gland dysfunction in prosthetic eye wearers

PurposeTo assess tear cytokine levels and clinical outcomes in meibomian gland dysfunction (MGD) in the blind eye of patients wearing an ocular prosthesis after 2 months of treatment with topical loteprednol etabonate and eyelid scrubs with warm compresses.Patients and methodsThis study included patients with MGD wearing a unilateral ocular prosthesis for more than 1 year. All patients topically received 0.5% loteprednol etabonate and were instructed to scrub their eyelids with warm compresses on the prosthetic eye for 2 months. We evaluated tear cytokine levels using Multiplex Bead Immunoassays, performed biomicroscopic examination of the lid margins and meibomian gland, conducted meibography imaging, and assessed MGD-related ocular symptoms using a questionnaire for the prosthetic eye before and 2 months after treatment.ResultsThirty consecutive patients were included. There were significant reductions in the levels of interleukin (IL)-6, interferon-γ, monocyte chemotactic protein-1, IL-8, tumor necrosis factor-α, and IL-1β (P<0.001 for each cytokine). Moreover, there were improvements in ocular symptoms (P=0.001), lid margin abnormalities (P<0.001), meibomian gland expressibility (P<0.001) and meibography findings (P=0.037).ConclusionTopical loteprednol etabonate in conjunction with eyelid scrubs and warm compresses were effective in treating MGD in prosthetic eye wearers. Furthermore, tear cytokine measurements may serve as an additional approach for evaluating the efficacy of anti-inflammatory treatment for MGD in prosthetic eye wearers.

Unsupervised Learning in PET Radiomics

In this study, we investigated large scale radoimics on 116 breast cancer patients. We are particularly interested in unsupervised learning to bicluster patients and features in order to associate such biclusters with the disease characteristics. The results show that radiomics features with wavelet features have a better biclustering ability. And 172 radiomics features have shown a better classification capability.

[18F]-Sodium Fluoride PET MR-Based Localization and Quantification of Bone Turnover as a Biomarker for Facet Joint-Induced Disability

Our aim was to prospectively evaluate the relationship between low back pain-related disability and quantitative measures from [¹⁸F]-sodium fluoride ([¹⁸F]-NaF) MR imaging. Six patients with facetogenic low back pain underwent dynamic [¹⁸F]-NaF PET/MR imaging. PET metrics were correlated with clinical measures and MR imaging grading of lumbar facet arthropathy. A significant positive correlation was observed between maximum facet joint uptake rate and clinical disability (P < .05). These data suggest that dynamic [¹⁸F]-NaF PET may serve as a useful biomarker for facetogenic disability.

Test of a 32-channel Prototype ASIC for Photon Counting Application

A new low-power application-specific integrated circuit (ASIC) for Cadmium Zinc Telluride (CZT) detectors for single-photon emission computed tomography (SPECT) application is being developed at BNL. As the first step, a 32-channel prototype ASIC was designed and tested recently. Each channel has a preamplifier followed by CR-RC³ shaping circuits and three independent energy bins with comparators and 16-bit counters. The ASIC was fabricated with TSMC 0.35-μm complementary metal-oxide-semiconductor (CMOS) process and tested in laboratories. The power consumption is around 1 mW/ch with a 2.5-V supply. With a gain of 400 mV/fC and the peaking time of 500 ns, the equivalent noise charge (ENC) of 360 e- has been measured in room temperature while the crosstalk rate is less than 0.3%. The 10-bit DACs for global thresholds have an integral nonlinearity (INL) less than 0.56% and differential nonlinearity (DNL) less than 0.33%. In the presentation, we will report the detailed test results with this ASIC.

Extrusion Foaming Behavior of PBT Resins

An investigation of the foaming behavior of polybutylene terephthalate (PBT) resins in extrusion is performed. Commercial grades of PBT with different molecular weights and rheological characteristics are chosen. PBTs with a high temperature chemical blowing agent are extruded under different material and operational conditions (e.g., amount of blowing agent, set temperature at the die, screw RPM, etc.) to allow the understanding of the effects of those conditions on product characteristics. The foamed extrudates are analyzed for density, morphology, and crystallinity. It is shown that the foaming behavior and the foam quality of PBT are functions of the characteristic properties of the resins including rheological and crystallization behavior.

Stability of the Baseline Holder in Readout Circuits For Radiation Detectors

Baseline holder (BLH) circuits are used widely to stabilize the analog output of application-specific integrated circuits (ASICs) for high-count-rate applications. The careful design of BLH circuits is vital to the overall stability of the analog-signal-processing chain in ASICs. Recently, we observed self-triggered fluctuations in an ASIC in which the shaping circuits have a BLH circuit in the feedback loop. In fact, further investigations showed that methods of enhancing small-signal stabilities cause an even worse situation. To resolve this problem, we used large-signal analyses to study the circuit's stability. We found that a relatively small gain for the error amplifier and a small current in the non-linear stage of the BLH are required to enhance stability in large-signal analysis, which will compromise the properties of the BLH. These findings were verified by SPICE simulations. In this paper, we present our detailed analysis of the BLH circuits, and propose an improved version of them that have only minimal self-triggered fluctuations. We summarize the design considerations both for the stability and the properties of the BLH circuits.