Discovery and preclinical development of a therapeutically active nanobody-based chimeric antigen receptor targeting human CD22

Chimeric antigen receptor (CAR) T cell therapies targeting B cell-restricted antigens CD19, CD20, or CD22 can produce potent clinical responses for some B cell malignancies, but relapse remains common. Camelid single-domain antibodies (sdAbs or nanobodies) are smaller, simpler, and easier to recombine than single-chain variable fragments (scFvs) used in most CARs, but fewer sdAb-CARs have been reported. Thus, we sought to identify a therapeutically active sdAb-CAR targeting human CD22. Immunization of an adult Llama glama with CD22 protein, sdAb-cDNA library construction, and phage panning yielded >20 sdAbs with diverse epitope and binding properties. Expressing CD22-sdAb-CAR in Jurkat cells drove varying CD22-specific reactivity not correlated with antibody affinity. Changing CD28- to CD8-transmembrane design increased CAR persistence and expression in vitro. CD22-sdAb-CAR candidates showed similar CD22-dependent CAR-T expansion in vitro, although only membrane-proximal epitope targeting CD22-sdAb-CARs activated direct cytolytic killing and extended survival in a lymphoma xenograft model. Based on enhanced survival in blinded xenograft studies, a lead CD22sdCAR-T was selected, achieving comparable complete responses to a benchmark short linker m971-scFv CAR-T in high-dose experiments. Finally, immunohistochemistry and flow cytometry confirm tissue and cellular-level specificity of the lead CD22-sdAb. This presents a complete report on preclinical development of a novel CD22sdCAR therapeutic.

The role of the Toll like receptor 4 signaling in sex-specific persistency of depression-like behavior in response to chronic stress

Chronic stress is a major risk factor for Major Depressive Disorder (MDD), and it has been shown to impact the immune system and cause microglia activation in the medial prefrontal cortex (mPFC) involved in the pathogenesis of depression. The aim of this study is to further investigate cellular and molecular mechanisms underlying persistent depression behavior in sex specific manner, which is observed clinically. Here, we report that both male and female mice exhibited depression-like behavior following exposure to chronic stress. However, only female mice showed persistent depression-like behavior, which was associated with microglia activation in mPFC, characterized by distinctive alterations in the phenotype of microglia. Given these findings, to further investigate the underlying molecular mechanisms associated with persistent depression-like behavior and microglia activation in female mice, we used translating-ribosome affinity purification (TRAP). We find that Toll like receptor 4 (TLR4) signaling is casually related to persistent depression-like behavior in female mice. This is supported by the evidence that the fact that genetic ablation of TLR4 expression in microglia significantly reduced the persistent depression-like behavior to baseline levels in female mice. This study tentatively supports the hypothesis that the TLR4 signaling in microglia may be responsible for the sex differences in persistent depression-like behavior in female.

The Implementation of Precise Point Positioning (PPP): A Comprehensive Review

High-precision positioning from Global Navigation Satellite Systems (GNSS) has garnered increased interest due to growing demand in various applications, like autonomous car navigation and precision agriculture. Precise Point Positioning (PPP) offers a distinct advantage over differential techniques by enabling precise position determination of a GNSS rover receiver through the use of external corrections sourced from either the Internet or dedicated correction satellites. However, PPP's implementation has been challenging due to the need to mitigate numerous GNSS error sources, many of which are eliminated in differential techniques such as Real-Time Kinematics (RTK) or overlooked in Standard Point Positioning (SPP). This paper extensively reviews PPP's error sources, such as ionospheric delays, tropospheric delays, satellite orbit and clock errors, phase and code biases, and site displacement effects. Additionally, this article examines various PPP models and correction sources that can be employed to address these errors. A detailed discussion is provided on implementing the standard dual-frequency (DF)-PPP to achieve centimeter- or millimeter-level positioning accuracy. This paper includes experimental examples of PPP implementation results using static data from the International GNSS Service (IGS) station network and a kinematic road test based on the actual trajectory to showcase DF-PPP development for practical applications. By providing a fusion of theoretical insights with practical demonstrations, this comprehensive review offers readers a pragmatic perspective on the evolving field of Precise Point Positioning.

Impact of an NCCN-Compliant Multidisciplinary Conference on Treatment Decisions for Localized Prostate Cancer

BACKGROUND

We sought to investigate the impact of an NCCN-compliant multidisciplinary conference on treatment decisions of patients with localized prostate cancer.

METHODS

A retrospective review of our quality assurance localized prostate cancer database was performed. All patients with localized prostate cancer who sought a second opinion at Roswell Park Comprehensive Cancer Center between 2009 and 2019 were presented to the multidisciplinary Localized Prostate Cancer Conference (LPCC) that includes urologists, radiation oncologists, pathologists, and patient advocates. Multivariable regression models were fit to evaluate variables associated with concordance between community recommendations, LPCC recommendations, and treatment received by patients.

RESULTS

A total of 1,164 patients were identified, of whom 26% had NCCN very low-/low-risk, 27% had favorable intermediate-risk, 25% had unfavorable intermediate-risk, and 22% had high-/very high-risk prostate cancer. Pathology changed in 11% of patients after genitourinary pathologist review, which caused disease reclassification in 9%. Concordance between community and LPCC recommendations occurred in 78%, with lowest concordance for androgen deprivation therapy (21%) and radiotherapy (53%). Concordance between community recommendations and treatment received occurred in 65%, with lowest concordance for androgen deprivation therapy and radiotherapy; among those who were recommended radiotherapy as the only option by their community urologist, only 26% received it. Concordance between LPCC recommendations and treatment received occurred in 92%.

CONCLUSIONS

Community recommendations differed from the multidisciplinary NCCN-compliant recommendations in 22% of patients, primarily for radiotherapy. Multidisciplinary recommendations matched the treatment received in 92% of patients compared with 65% for community recommendations.

Real-Time Safe Landing Zone Identification Based on Airborne LiDAR

Over the past two decades, there has been a growing demand for generating digital surface models (DSMs) in real-time, particularly for aircraft landing in degraded visual environments. Challenging landing environments can hinder a pilot's ability to accurately navigate, see the ground, and avoid obstacles that may lead to equipment damage or loss of life. While many accurate and robust filtering algorithms for airborne laser scanning (ALS) data have been developed, they are typically computationally expensive. Moreover, these filtering algorithms require high execution times, making them unsuitable for real-time applications. This research aims to design and implement an efficient algorithm that can be used in real-time on limited-resource embedded processors without the need for a supercomputer. The proposed algorithm effectively identifies the best safe landing zone (SLZ) for an aircraft/helicopter based on processing 3D LiDAR point cloud data collected from a LiDAR mounted on the aircraft/helicopter. The algorithm was successfully implemented in C++ in real-time and validated using professional software for flight simulation. By comparing the results with maps, this research demonstrates the ability of the developed method to assist pilots in identifying the safest landing zone for helicopters.

Evaluation of Adjuvant Activity and Bio-Distribution of Archaeosomes Prepared Using Microfluidic Technology

Archaeosomes, composed of sulfated lactosyl archaeol (SLA) glycolipids, have been proven to be an effective vaccine adjuvant in multiple preclinical models of infectious disease or cancer. They have classically been prepared using a thin-film hydration method with an average particle size of 100-200 nm. In this study, we developed methods to generate SLA archaeosomes at different sizes, i.e., 30 nm and 100 nm, via microfluidic mixing technology and evaluated their physicochemical characteristics, as well as adjuvant activity and in vivo biodistribution in mice. Archaeosomes, prepared using thin-film and microfluidic mixing techniques, had similar nanostructures and physicochemical characteristics, with both appearing stable during the course of this study when stored at 4 °C or 37 °C. They also demonstrated similar adjuvant activity when admixed with ovalbumin antigen and used to immunize mice, generating equivalent antigen-specific immune responses. Archaeosomes, labeled with CellVueTM NIR815, had an equivalent biodistribution with both sizes, namely the highest signal at the injection site at 24 h post injection, followed by liver, spleen and inguinal lymph node. The presence of SLA archaeosomes of either size helped to retain OVA antigen (OVA-Cy5.5) longer at the injection site than unadjuvanted OVA. Overall, archaeosomes of two sizes (30 nm and 100 nm) prepared using microfluidic mixing maintained similar physicochemical properties, adjuvant activity and biodistribution of antigen, in comparison to those compared by the conventional thin film hydration method. This suggests that microfluidics based approaches could be applied to generate consistently sized archaeosomes for use as a vaccine adjuvant.

Correction: Elsheikh et al. Low-Cost Real-Time PPP/INS Integration for Automated Land Vehicles. Sensors 2019, 19, 4896

The authors wish to make the following corrections in the original paper [...].

Relapses Rates and Patterns for Pathological T0 After Robot-Assisted Radical Cystectomy: Results From the International Robotic Cystectomy Consortium

OBJECTIVES

To investigate the oncologic outcomes of pT0 after robot-assisted radical cystectomy (RARC).

METHODS

A retrospective review of the International Robotic Cystectomy Consortium database was performed. Patients with pT0 after RARC were identified and analyzed. Data were reviewed for demographics and pathologic outcomes. Kaplan-Meier curves were used to depict recurrence-free survival (RFS), disease-specific survival (DSS), and overall survival (OS). Multivariate stepwise Cox regression models were used to identify variables associated with RFS and OS.

RESULTS

Four hundred seventy-one patients (18%) with pT0 were identified. Median age was 68 years (interquartile range (IQR) 60-73), with a median follow up of 20 months (IQR 6-47). Thirty-seven percent received neoadjuvant chemotherapy and 5% had pN+ disease. Seven percent of patients experienced disease relapse; 3% had local and 5% had distant recurrence. Most common sites of local and distant recurrences were pelvis (1%) and lungs (2%). Five-year RFS, DSS, and OS were 88%, 93%, and 79%, respectively. Age (hazards ratio [HR] 1.05, 95% confidence interval [CI] 1.01-1.09, P = 0.02), pN+ve (HR 11.48, 95% CI 4.47-29.49, P < .01), and reoperations within 30 days (HR 5.53, 95% CI 2.08-14.64, P < .01) were associated with RFS. Chronic kidney disease (HR 3.24, 95% CI 1.45-7.23, P < .01), neoadjuvant chemotherapy (HR 0.41, 95% CI 0.18-0.92, P = .03), pN+ve (HR 4.37, 95% CI 1.46-13.06, P < .01), and reoperations within 30 days (HR 2.64, 95% CI, 1.08-6.43, P = .03) were associated with OS.

CONCLUSIONS

Despite pT0 status at RARC, 5% had pN+ disease and 7% of patients relapsed. Node status was the variable strongest associated with RFS and OS in pT0.

Microbubble drug conjugate and focused ultrasound blood brain barrier delivery of AAV-2 SIRT-3

BACKGROUND

Delivery of viral vectors as gene therapies to treat neurodegenerative diseases has been hampered by the inability to penetrate the blood brain barrier (BBB) and invasive or non-targeted delivery options prone to inducing immune responses. MR guided focused ultrasound (MR-g-FUS) and microbubbles have demonstrated safe, temporary, targeted BBB permeabilization clinically.

METHODS

We developed clinically scalable, microbubble drug conjugates (MDCs) for the viral gene therapy, AAV.SIRT3-myc [adeno-associated virus expressing myc-tagged SIRT3], which has previously been shown to have disease modifying effects in animal models of Parkinson's disease (PD). The lipid shells of the perfluorocarbon gas MDCs were covalently conjugated to antibodies with binding specificity to AAVs. Following systemic (iv) delivery of AAV.SIRT3-myc MDCs, MR-g-FUS was used to deliver SIRT3-myc to brain regions affected in PD. SIRT3-myc expression was determined post mortem, using immunohistochemistry.

RESULTS

An in vitro, SH-SY5Y cell culture model was used to show that the localized destruction of MDCs using ultrasound exposures within biological safety limits dissociated AAV2-GFP (green fluorescent protein) from the MDCs in the targeted area while maintaining their transduction capacity. In rats, MR-g-FUS resulted in BBB permeabilization in the striatum and substantia nigra (SNc). SIRT3-myc was expressed in the striatum, but not the SNc.

CONCLUSION

These studies demonstrate that MDCs combined with MR-g-FUS are an effective method for delivery of viral vector gene therapies, such as AAV.SIRT3, to brain regions affected in PD. This technology may prove useful as a disease-modifying strategy in PD and other neurodegenerative disorders.

Perioperative and Functional Outcomes of Robot-assisted Ureteroenteric Reimplantation: A Multicenter Study of Seven Referral Institutions

Background

Open revision of ureteroenteric strictures (UESs) is associated with considerable morbidity. There is a lack of data evaluating the feasibility of robotic revisions.

Objective

To analyze the perioperative and functional outcomes of robot-assisted ureteroenteric reimplantation (RUER) for the management of UESs after radical cystectomy (RC).

Design, setting, and participants

A retrospective multicenter study of 61 patients, who underwent 63 RUERs at seven high-volume institutions between 2009 and 2020 for benign UESs after RC, was conducted.

Outcome measurements and statistical analysis

Data were reviewed for demographics, stricture characteristics, and perioperative outcomes. Variables associated with being stricture free after an RUER were evaluated using a multivariate Cox regression analysis.

Results and limitations

Among 63 RUERs, 22 were right sided (35%), 34 left sided (54%), and seven bilateral (11%). Twenty-seven (44%) had prior abdominal/pelvic surgery and five (8%) radiotherapy (RT). Thirty-two patients had American Society of Anesthesiologists (ASA) scores I–II (52%) and 29 ASA III (48%). Forty-two (68%) RUERs were in ileal conduits, 18 (29%) in neobladders, and two (3%) in Indiana pouch. The median time to diagnosis of a UES from cystectomy was 5 (3–11) mo. Of the UESs, 28 (44%) failed an endourological attempt (balloon dilatation/endoureterotomy). The median RUER operative time was 195 (175–269) min. No intraoperative complications or conversions to open approach were reported. Twenty-three (37%) patients had postoperative complications (20 [32%] were minor and three [5%] major). The median length of hospital stay was 3 (1–6) d and readmissions were 5%. After a median follow-up of 19 (8–43) mo, 84% of cases were stricture free. Lack of prior RT was the only variable associated with better stricture-free survival after RUER (hazard ratio 6.8, 95% confidence interval 1.10–42.00, p = 0.037). The study limitations include its retrospective nature and the small number of patients.

Conclusions

RUER is a feasible procedure for the management of UESs. Prospective and larger studies are warranted to prove the safety and efficacy of this technique.

Patient summary

In this study, we investigate the feasibility of a novel minimally invasive technique for the management of ureteroenteric strictures. We conclude that robotic reimplantation is a feasible and effective procedure.

Development and Validation of an Objective Scoring Tool for Robot-Assisted Partial Nephrectomy: Scoring for Partial Nephrectomy

Objective: To develop a structured and objective scoring tool for assessment of robot-assisted partial nephrectomy (RAPN): Scoring for Partial Nephrectomy (SPaN). Materials and Methods: Content development: RAPN was deconstructed into 6 domains by a multi-institutional panel of 10 expert robotic surgeons. Performance on each domain was represented on a Likert scale of 1 to 5, with specific descriptions of anchors 1, 3, and 5. Content validation: The Delphi methodology was utilized to achieve consensus about the description of each anchor for each domain in terms of appropriateness of the skill assessed, objectiveness, clarity, and unambiguous wording. The content validity index (CVI) of ≥0.75 was set as cutoff for consensus. Reliability: 15 de-identified videos of RAPN were utilized to determine the inter-rater reliability using linearly weighted percent agreement, and Construct validation of SPaN was described in terms of median scores and odds ratios. Results: The expert panel reached consensus (CVI ≥0.75) after 2 rounds. Consensus was achieved for 36 (67%) statements in the first round and 18 (33%) after the second round. The final six-domain SPaN included Exposure of the kidney; Identification and dissection of the ureter and gonadal vessels; Dissection of the hilum; Tumor localization and exposure; Clamping and tumor resection; and Renorrhaphy. The linearly weighted percent agreement was >0.75 for all domains. There was no difference between median scores for any domain between attendings and trainees. Conclusion: Despite the lack of significant construct validity, SPaN is a structured, reliable, and procedure-specific tool that can objectively assesses technical proficiency for RAPN.

Ileal conduit versus neobladder: A propensity score-matched analysis of the effect on renal function

OBJECTIVES

To analyze the long-term effects of continent (neobladder) compared with incontinent (ileal conduit) urinary diversion.

METHODS

We carried out a retrospective review of our departmental database. Estimated glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Neobladder and ileal conduit patients were matched in a 1:2 ratio and a propensity score-matched analysis was carried out. Data were summarized using descriptive analysis. Trend plots were generated using baseline and follow-up creatinine values to compare estimated glomerular filtration rate at 3 months, then annually for 5 years. Variables associated with estimated glomerular filtration rate were assessed using multivariate linear analysis.

RESULTS

Our cohort consisted of 137 patients (neobladder n = 50 and ileal conduit n = 87) with a median follow-up time of 3 years (interquartile range 1-7 years). The ileal conduit group had shorter operative times (352 vs 444 min, P < 0.01), intracorporeal diversions were more common (66% vs 44%, P = 0.01), had prior abdominal surgery (66% vs 38%, P < 0.01) and had radiation (9% vs 0%, P = 0.03). The neobladder group more commonly had recurrent urinary tract infections (22% vs 3%, P < 0.01) and a steeper decrease in estimated glomerular filtration rate in the first year. On multivariate linear analysis, age/year (-0.59), body mass index per kg/m² (-0.52), preoperative estimated glomerular filtration rate per unit (0.51), recurrent urinary tract infections (-14.03) and time versus day 90 (year 1, -7.52; year 2, -9.06; year 3, -10.78) were significantly associated with estimated glomerular filtration rate.

CONCLUSION

Ileal conduits and neobladders showed a similar effect on the estimated glomerular filtration rate up to 5 years after robot-assisted radical cystectomy. Recurrent urinary tract infections were associated with a worse estimated glomerular filtration rate.

Dural Follicular Lymphoma: Case Report and Literature Review

Follicular lymphoma (FL) usually has an indolent course and presents with painless, waxing and waning lymphadenopathy in the absence of systemic symptoms. It is uncommon for FL to present outside of lymph nodes, although it can develop in the gastrointestinal tract, skin, thyroid, and testes. Central nervous system (CNS) involvement in FL is rare. Most CNS lymphomas are diffuse large B-cell lymphoma, although Burkitt lymphoma, lymphoblastic lymphoma, and peripheral T-cell lymphoma are also observed. These tumors usually involve white matter but may also involve gray matter. Lymphomas of the dura are very uncommon and are usually mucosa-associated lymphoid tissue lymphomas. Here, we present a case of FL of the dura arising in a 62-year-old woman that was responsive to chemotherapy. According to a literature review, there have been 15 previously reported cases of FL of the dura. Dural FL has been most frequently treated with radiation and chemotherapy. Patients were still alive in all cases in which follow-up was reported. Although the sample size is small, these data suggest that dural FL, like other forms of FL, is an indolent disease that is associated with prolonged survival despite usually being incurable.

Patterns and predictors of relapse in Merkel cell carcinoma: Results from a population-based study

BACKGROUND AND PURPOSE

Prospective data evaluating the role of adjuvant radiotherapy (RT) for Merkel Cell Carcinoma(MCC) is lacking. To better understand the efficacy of adjuvant RT, a population-based patterns of failure study was conducted.

METHODS

We identified MCC patients treated from 1988 to 2018.Primary outcome measures were recurrence-free survival (RFS), overall survival (OS) and MCC-specific survival (MCC-SS). Charlson Co-morbidity Index (CCI) was also calculated.

RESULTS

217 patients with mean age 79 (range: 33-96) were analyzed. The median follow-up was 40 months. Treatments were: surgery(S) alone (n = 101, 45%) or S + RT(n = 116, 55%).Local recurrence (LR) was low in stage I (n = 6, 6.5%) with clear margin of ≥1 cm, negative sentinel lymph node biopsy (SLNB) without high-risk factors, irrespective of adjuvant RT. Tumor size ≥ 2 cm (HR:2.95; p = 0.024) and immunosuppression(HR:3.98; p = 0.001) were associated with high risk of nodal failure. Adjuvant RT was associated with significant reduction in regional failure (HR:0.36; p = 0.002). Distant metastases (DM) were infrequent in stage I (4/90) and stage II (4/34), compared to stage III (32/93). Adjuvant RT improvedRFS but did not influence MCC-SS and OS. CCI was a significant predictor of OS.

CONCLUSIONS

Adjuvant RT improvedRFS, withoutimpact on MCC-SS and OS. Co-morbidity rather than RT influenced OS. Adjuvant RT may be avoided instage I patients with negative SLNB and no associated high-risk factors. Prophylactic RNI could be considered in stage II with high risk features, inspite of negative SLNB. Stage III patients benefited from adjuvant RNI, but no impact on prevention of DM.

Intracorporeal Versus Extracorporeal Neobladder After Robot-assisted Radical Cystectomy: Results From the International Robotic Cystectomy Consortium

OBJECTIVE

To compare perioperative and oncologic outcomes of intracorporeal (ICNB) and extracorporeal neobladder (ECNB) following robot assisted radical cystectomy (RARC) from a multi-institutional, prospectively maintained database, the International Robotic Cystectomy Consortium (IRCC).

METHODS

A retrospective review of IRCC database between 2003 and 2020 (3742 patients from 33 institutions across 14 countries) was performed (I-79606). The Cochran-Armitage trend test was used to assess utilization of ICNB over time. Multivariate logistic regression models were fit to evaluate variables associated with receiving ICNB, overall complications, high-grade complications, and readmissions after RARC. Kaplan Meier curves were used to depict recurrence-free, disease-specific, and overall survival.

RESULTS

Four hundred eleven patients received neobladder, 64% underwent ICNB. ICNB utilization increased significantly over time (P <.01). Patients who received ICNB were readmitted and received neoadjuvant chemotherapy more frequently (36% vs 24%, P = .03, 35% vs 8%, P <.01, respectively). ICNB was associated with older age (OR 1.04, 95% CI 1.01-1.07, P = .001), receipt of neoadjuvant chemotherapy (OR 4.63, 95% CI 2.34-9.18, P <.01), and more recent RARC era (2016-2020) (OR 12.6, 95% CI 5.6-28.4, P <.01). On multivariate analysis, ICNB (OR 5.43, 95% CI 2.34-12.58, P <.01), positive surgical margin (OR 4.88, 95% CI 1.29-18.42, P = .019), longer operative times (OR 1.26, 95% CI 1.00-1.58, P = .048), and institutional annual RARC volume (OR 1.09, 95% CI 1.05-1.12, P <.01) were associated with readmissions.

CONCLUSION

Utilization of ICNB increased significantly over time. Patients who underwent RARC and ICNB had shorter hospital stays and fewer 30-d reoperations but were readmitted more frequently compared to those who underwent ECNB.

Utilizing deep neural networks and electroencephalogram for objective evaluation of surgeon's distraction during robot-assisted surgery

OBJECTIVE

To develop an algorithm for objective evaluation of distraction of surgeons during robot-assisted surgery (RAS).

MATERIALS AND METHODS

Electroencephalogram (EEG) of 22 medical students was recorded while performing five key tasks on the robotic surgical simulator: Instrument Control, Ball Placement, Spatial Control II, Fourth Arm Tissue Retraction, and Hands-on Surgical Training Tasks. All students completed the Surgery Task Load Index (SURG-TLX), which includes one domain for subjective assessment of distraction (scale: 1-20). Scores were divided into low (score 1-6, subjective label: 1), intermediate (score 7-12, subjective label: 2), and high distraction (score 13-20, subjective label: 3). These cut-off values were arbitrarily considered based on a verbal assessment of participants and experienced surgeons. A Deep Convolutional Neural Network (CNN) algorithm was trained utilizing EEG recordings from the medical students and used to classify their distraction levels. The accuracy of our method was determined by comparing the subjective distraction scores on SURG-TLX and the results from the proposed classification algorithm. Also, Pearson correlation was utilized to assess the relationship between performance scores (generated by the simulator) and distraction (Subjective assessment scores).

RESULTS

The proposed end-to-end model classified distraction into low, intermediate, and high with 94%, 89%, and 95% accuracy, respectively. We found a significant negative correlation (r = -0.21; p = 0.003) between performance and SURG-TLX distraction scores.

CONCLUSIONS

Herein we report, to our knowledge, the first objective method to assess and quantify distraction while performing robotic surgical tasks on the robotic simulator, which may improve patient safety. Validation in the clinical setting is required.

Upstaging and Survival Outcomes for Non-Muscle Invasive Bladder Cancer After Radical Cystectomy: Results from the International Robotic Cystectomy Consortium

INTRODUCTION

We sought to describe the incidence, risk factors, and survival outcomes associated with pathological upstaging from non-muscle invasive bladder cancer (NMIBC) to muscle invasive bladder cancer (MIBC) after robot-assisted radical cystectomy (RARC).

METHODS

We reviewed the International Robotic Cystectomy Consortium database between 2004 and 2020. Upstaging was defined as ≥pT2 or pN+ at final pathology from clinical <T2N0M0. Descriptive statistics were used to summarize data. Cochran-Armitage test was used to depict upstaging trend over time. Multivariate regression models were used to depict variables associated with upstaging. Kaplan Meier curves were used to describe disease-specific (DSS), recurrence-free (RFS), and overall survival (OS).

RESULTS

463 patients underwent RARC for NMIBC. Upstaging occurred in 145 (31%) patients. Upstaged patients were older (70 vs 67 years, p <0.01), more likely to have American Society of Anesthesiologists score (≥3) (55% vs 44%, p=0.04) and had higher rate of preoperative hydronephrosis (26% vs 10%, p <0.01). They were more likely to have positive surgical margins (10% vs 3%, p= 0.01), recurrences (28% vs 9%, p<0.01), and to receive adjuvant/salvage treatment (26% vs none, p <0.01). On multivariate analysis, upstaging was associated with older age (OR 1.04; CI 1.01-1.07, p<0.01), cT1 vs cTis (OR 4.25; CI 1.57-11.48, p <0.01), cT1 vs cTa (OR 2.92; CI 1.40-6.06, p<0.01), and preoperative hydronephrosis (OR 3.18; CI 1.60-6.32, p<0.01). Upstaged patients had worse 5-year RFS (53 % vs 85%, log rank p<0.01), DSS (66% vs 93%, log rank p<0.01), and OS (49% vs 74%, log rank p<0.01). The rate of upstaging did not significantly change over time (38% in 2004 to 27% in 2019, p=0.17).

CONCLUSION

Upstaging to MIBC occurred in a significant proportion of patients after RARC for NMIBC and was associated with worse survival outcomes. Older patients, those with cT1 disease and hydronephrosis were more likely to upstage.

Functional outcomes after robot-assisted radical cystectomy: A review of literature

Robot-assisted radical cystectomy has steadily gained wider acceptance among urologists compared with open and laparoscopic approaches. Robot-assisted radical cystectomy has shown comparable perioperative and oncologic outcomes compared with open radical cystectomy. Nevertheless, data about the functional outcomes and quality of life after robot-assisted radical cystectomy remain limited. We sought to review the literature and describe urinary, sexual and bowel functions after robot-assisted radical cystectomy in addition to mental health and health-related quality of life. Despite limitations of the available literature, data suggests that functional outcomes after robot-assisted radical cystectomy are comparable to open radical cystectomy. However, more studies utilizing standardized definitions are required.

Surgical Hand Gesture Recognition Utilizing Electroencephalogram as Input to the Machine Learning and Network Neuroscience Algorithms

Surgical gestures detection can provide targeted, automated surgical skill assessment and feedback during surgical training for robot-assisted surgery (RAS). Several sources including surgical videos, robot tool kinematics, and an electromyogram (EMG) have been proposed to reach this goal. We aimed to extract features from electroencephalogram (EEG) data and use them in machine learning algorithms to classify robot-assisted surgical gestures. EEG was collected from five RAS surgeons with varying experience while performing 34 robot-assisted radical prostatectomies over the course of three years. Eight dominant hand and six non-dominant hand gesture types were extracted and synchronized with associated EEG data. Network neuroscience algorithms were utilized to extract functional brain network and power spectral density features. Sixty extracted features were used as input to machine learning algorithms to classify gesture types. The analysis of variance (ANOVA) F-value statistical method was used for feature selection and 10-fold cross-validation was used to validate the proposed method. The proposed feature set used in the extra trees (ET) algorithm classified eight gesture types performed by the dominant hand of five RAS surgeons with an accuracy of 90%, precision: 90%, sensitivity: 88%, and also classified six gesture types performed by the non-dominant hand with an accuracy of 93%, precision: 94%, sensitivity: 94%.

7-Fluorosialyl Glycosides Are Hydrolysis Resistant but Readily Assembled by Sialyltransferases Providing Easy Access to More Metabolically Stable Glycoproteins

The maintenance of therapeutic glycoproteins within the circulatory system is associated, in large part, with the integrity of sialic acids as terminal sugars on the glycans. Glycoprotein desialylation, either by spontaneous cleavage or through host sialidases, leads to protein clearance, mainly through the liver. Thus, the installation of minimally modified sialic acids that are hydrolysis-resistant yet biologically equivalent should lead to increased circulatory half-lives and improved pharmacokinetic profiles. Here we describe the chemoenzymatic synthesis of CMP-sialic acid sugar donors bearing fluorine atoms at the 7-position, starting from the corresponding 4-deoxy-4-fluoro-N-acetylhexosamine precursors. For the derivative with natural stereochemistry we observe efficient glycosyl transfer by sialyltransferases, along with improved stability of the resultant 7-fluorosialosides toward spontaneous hydrolysis (3- to 5-fold) and toward cleavage by GH33 sialidases (40- to 250-fold). Taking advantage of the rapid transfer of 7-fluorosialic acid by sialyltransferases, we engineered the O-glycan of Interferon α-2b and the N-glycans of the therapeutic glycoprotein α1-antitrypsin. Studies of the uptake of the glyco-engineered α1-antitrypsin by HepG2 liver cells demonstrated the bioequivalence of 7-fluorosialic acid to sialic acid in suppressing interaction with liver cell lectins. In vivo pharmacokinetic studies reveal enhanced half-life of the protein decorated with 7-fluorosialic acid relative to unmodified sialic acid in the murine circulatory system. 7-Fluorosialylation therefore offers considerable promise as a means of prolonging circulatory half-lives of glycoproteins and may pave the way toward biobetters for therapeutic use.

Validation of the Khorana Score for Prediction of Venous Thromboembolism After Robot-Assisted Radical Cystectomy

Introduction: The Khorana score (KS) is used to predict the risk of venous thromboembolism (VTE) for cancer patients. We sought to assess the association between KS and VTE for patients who underwent robot-assisted radical cystectomy (RARC). Materials and Methods: We reviewed our prospectively maintained quality assurance RARC database between 2005 and 2020. KS was calculated for all patients (one point for each body mass index [BMI] ≥35 kg/m², platelet count ≥350 × 10⁹/L, leukocyte count >11 × 10⁹/L, and hemoglobin level <10 g/dL, or use of erythropoiesis-stimulating agents). All patients received one point by default for the cancer type (bladder). Patients were divided into intermediate-risk (KS 1-2) or high-risk (KS ≥3) groups. Receiver operating characteristic curve was used to assess the ability of KS to predict VTE. Kaplan-Meier curves were stratified based on their KS risk and used to depict overall survival (OS). Multivariate analysis (MVA) was used to identify variables associated with VTE. Results: Out of 589 patients, 33 (6%) developed VTE (18 had deep vein thrombosis and 15 had pulmonary embolism). Five hundred forty-six (93%) patients had intermediate-risk KS and 30 (5%) of them developed VTE. Forty-three (7%) patients were classified as high-risk KS and 3 (7%) developed VTE. This difference was not significant (p = 0.73). The KS area under the curve for VTE prediction was 0.51. On MVA, BMI ≥35 kg/m² (odds ratio [OR] 2.69, confidence interval [CI] 1.19-6.11, p = 0.02), longer inpatient stay (OR 1.04, CI 1.003-1.07, p = 0.03), and ≥pT₃ disease (OR 2.29, CI 1.11-4.71, p = 0.03) were associated with VTE, whereas KS was not associated with VTE (p = 0.68). Five-year OS of patients with intermediate KS was 53% compared with 30% for high-risk KS (log rank p < 0.01). Conclusion: KS underestimated VTE risk after RARC and showed poor accuracy. This highlights the need to develop procedure-specific tools to estimate the risk of VTE after RARC.

Prevalence and Predictors of Venous Thromboembolism After Robot-Assisted Radical Cystectomy

OBJECTIVE

To describe incidence and variables associated with venous thromboembolism (VTE) after robot-assisted radical cystectomy (RARC).

METHODS

A retrospective review of the prospectively maintained departmental database was performed. Extended thromboprophylaxis (for 4 weeks postoperatively) was implemented November 2017. Patients were divided into VTE (deep venous thrombosis [DVT] and/or pulmonary embolism [PE]) and non-VTE groups. Baseline demographics, disease characteristics and perioperative outcomes were compared. Cochran-Armitage trend test was used to assess trends of VTE. Multivariate logistic regression was used to identify variables associated with VTE. The Kaplan-Meier method was used to depict recurrence free survival (RFS), disease specific survival (DSS), and overall survival (OS).

RESULTS

Twenty nine patients (5%) developed VTE (14 developed DVT and 15 developed PE). Median time to DVT was 28 days and to PE was 23 days after RARC. The rate of VTE remained stable between 2005 and 2020 (P= .99). Patients who developed VTE had significantly higher BMI (31 vs 29, P = .04), had COPD more often (34% vs 14%, P < .01) and had longer median hospital stay (8 vs 7 days, P = .01). Multivariate analysis showed that BMI (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.005-1.10; P = .03), COPD (OR 3.24; 95% CI 1.43-7.30; P < .01),and non-organ confined disease (OR 2.73; 95% CI 1.22-6.11; P = 0.01) were associated with VTE. Kaplan-Meier curves showed that patients who developed VTE exhibited similar RFS (79% vs 64%, P = .28), DSS (90% vs 76%, P = .17), and OS (54% vs 52%, P = .76) at 5 years compared to those who did not develop VTE.

CONCLUSION

VTE remains a significant complication after RARC. Higher BMI, COPD, and non-organ confined disease were significantly associated with VTE.

Mechanistic insight into the induction of cellular immune responses by encapsulated and admixed archaeosome-based vaccine formulations

Archaeosomes are liposomes formulated using total polar lipids (TPLs) or semi-synthetic glycolipids derived from archaea. Conventional archaeosomes with entrapped antigen exhibit robust adjuvant activity as demonstrated by increased antigen-specific humoral and cell-mediated responses and enhanced protective immunity in various murine infection and cancer models. However, antigen entrapment efficiency can vary greatly resulting in antigen loss during formulation and variable antigen:lipid ratios. In order to circumvent this, we recently developed an admixed archaeosome formulation composed of a single semi-synthetic archaeal lipid (SLA, sulfated lactosylarchaeol) which can induce similarly robust adjuvant activity as an encapsulated formulation. Herein, we evaluate and compare the mechanisms involved in the induction of early innate and antigen-specific responses by both admixed (Adm) and encapsulated (Enc) SLA archaeosomes. We demonstrate that both archaeosome formulations result in increased immune cell infiltration, enhanced antigen retention at injection site and increased antigen uptake by antigen-presenting cells and other immune cell types, including neutrophils and monocytes following intramuscular injection to mice using ovalbumin as a model antigen. In vitro studies demonstrate SLA in either formulation is preferentially taken up by macrophages. Although the encapsulated formulation was better able to induce antigen-specific CD8⁺ T cell activation by dendritic cells in vitro, both encapsulated and admixed formulations gave equivalently enhanced protection from tumor challenge when tested in vivo using a B16-OVA melanoma model. Despite some differences in the immunostimulatory profile relative to the SLA (Enc) formulation, SLA (Adm) induces strong in vivo immunogenicity and efficacy, while offering an ease of formulation.

Inhibition of lipopolysaccharide-induced inflammation via the protective role of T regulatory cells in the fetal liver in a late-pregnancy preterm mouse model

OBJECTIVES

This study intended to explore the effect of T regulatory cells (Tregs) in the perinatal liver against LPS-induced inflammation in a preterm birth mouse model. Moreover, the role of adoptive Tregs on the inflammatory response induced by LPS was also studied.

METHODS

Female BALB/C mice were injected intraperitoneally (IP) with LPS dissolved in normal saline solution at a dose of 50 µg/kg. Spleens from pregnant mice were used to obtain Tregs. The expression of Forkhead family transcription factor-3 (Foxp3), Interleukin-6 (IL-6), Toll-like receptor-4 (TLR-4), and Heme oxygenase-1 (HO-1) were assessed from fetal liver tissues by polymerase chain reaction and western blotting.

RESULTS

LPS administered to mice induced an inflammatory response in the perinatal liver, and this inflammatory response was negatively regulated by Tregs in the experimental group. Maternal-fetal tolerance was maintained by Tregs. Transmission of Tregs was estimated in different experimental groups based on the mRNA expression of TLR-4, IL-6, HO-1, and Foxp3.

CONCLUSIONS

After analysis of the experimental data, it was determined that Tregs exhibited regulatory potential against LPS-induced inflammatory response. Further, it was concluded that the transmission of Tregs improved the mother's immune tolerance against LPS-induced inflammation in the fetal liver.

Low-Cost Real-Time PPP/INS Integration for Automated Land Vehicles

The last decade has witnessed a growing demand for precise positioning in many applications including car navigation. Navigating automated land vehicles requires at least sub-meter level positioning accuracy with the lowest possible cost. The Global Navigation Satellite System (GNSS) Single-Frequency Precise Point Positioning (SF-PPP) is capable of achieving sub-meter level accuracy in benign GNSS conditions using low-cost GNSS receivers. However, SF-PPP alone cannot be employed for land vehicles due to frequent signal degradation and blockage. In this paper, real-time SF-PPP is integrated with a low-cost consumer-grade Inertial Navigation System (INS) to provide a continuous and precise navigation solution. The PPP accuracy and the applied estimation algorithm contributed to reducing the effects of INS errors. The system was evaluated through two road tests which included open-sky, suburban, momentary outages, and complete GNSS outage conditions. The results showed that the developed PPP/INS system maintained horizontal sub-meter Root Mean Square (RMS) accuracy in open-sky and suburban environments. Moreover, the PPP/INS system could provide a continuous real-time positioning solution within the lane the vehicle is moving in. This lane-level accuracy was preserved even when passing under bridges and overpasses on the road. The developed PPP/INS system is expected to benefit low-cost precise land vehicle navigation applications including level 2 of vehicle automation which comprises services such as lane departure warning and lane-keeping assistance.

PRIMING OF MICROGLIA ACTIVITY INCREASES SUSCEPTIBILITY TO DEPRESSION-LIKE BEHAVIORS

This study investigates the role of microglia activity in stress-induced depression and anxiety and the mechanisms associated with the role of certain microbiome derived anti-inflammatory polyphenols in attenuating stress-induced microglia immune priming and symptoms of depression. We implemented a chronic unpredictable stress (CUS) paradigm to exhibit priming of microglia innate immunity in the context of the onset of depression and anxiety phenotypes. Mechanistic studies related to prophylactic treatment using dietary microbiome derived polyphenols were also investigated in this model. Depression and anxiety phenotypes, gene expression in microglia and protein expression in the cortex of mice were measured following a primary exposure to short-term unpredictable stress (US) followed by CUS. We examined the long-term, persistent CUS induced changes at 4-weeks of post-stress rest following a secondary US exposure. We found depression phenotypes resulted from US only following exposure to CUS. This was accompanied by an increase and persistent upregulation of toll-like receptor 4 (TLR4), RAGE, and HMGB1 gene expression in isolated cortical microglia. Priming by CUS also amplified gene expression of IL-1β in microglia and protein IL-1β in the cerebral cortex following US re-exposure. Increased activity of NF-kB was also noted in the period following CUS. Furthermore, polyphenol treatment prevented stress-induced phenotypes, upregulation of HMGB1, IL-1B, and TLR4 gene expression, as well as upregulation of IL-1β and NF-kB. The study suggests that latent activity of the TLR4-NFkB-IL1β pathway contributes to immune priming and increases susceptibility to depression-like behaviors. Anti-depressant effects of polyphenols may result from their ability to attenuate microglia priming.

Single-Domain Antibodies as Therapeutic and Imaging Agents for the Treatment of CNS Diseases

Antibodies have become one of the most successful therapeutics for a number of oncology and inflammatory diseases. So far, central nervous system (CNS) indications have missed out on the antibody revolution, while they remain 'hidden' behind several hard to breach barriers. Among the various antibody modalities, single-domain antibodies (sdAbs) may hold the 'key' to unlocking the access of antibody therapies to CNS diseases. The unique structural features of sdAbs make them the smallest monomeric antibody fragments suitable for molecular targeting. These features are of particular importance when developing antibodies as modular building blocks for engineering CNS-targeting therapeutics and imaging agents. In this review, we first introduce the characteristic properties of sdAbs compared to traditional antibodies. We then present recent advances in the development of sdAbs as potential therapeutics across brain barriers, including their use for the delivery of biologics across the blood-brain and blood-cerebrospinal fluid (CSF) barriers, treatment of neurodegenerative diseases and molecular imaging of brain targets.

Thyroid function alterations attributed to high iodide supplementation in maternal rats and their offspring

OBJECTIVE

Our aim was to investigate thyroid function alterations attributed to high iodide supplementation in maternal rats and their offspring.

METHODS

Depending on their iodide intake, the pregnant rats were randomly divided into three groups: normal iodide intake (NI), 10 times high iodide intake (10 HI) and 100 times high iodide intake (100 HI) groups. Iodine concentration in the urine and maternal milk; iodine content and mitochondrial superoxide production; expression of TRα1, TRβ1, NIS and Dio1 in both the thyroid and mammary glands were all measured. The offspring were exposed to different iodide-containing water (NI, 10 HI and 100 HI) from weaning to postnatal day 180 (PN180). Serum thyroid hormone levels were measured in both maternal rats and their offspring.

RESULTS

Iodine concentration in the urine and maternal milk, as well as iodine content in the thyroid and mammary glands was significantly increased in both the 10 HI and 100 HI groups (p < .05). In the 100 HI group of maternal rats, low FT3 levels, high FT4, TPOAb and TgAb levels were detected. In addition, an increased mitochondrial superoxide production and decreased expression of TRα1, TRβ1, NIS and Dio1 in the thyroid and mammary glands was found (p < .05). A positive staining of CD4⁺ that co-localized with TRβ1 in the infiltrated cells within the thyroid follicles was observed. At PN180 in the offspring, the FT3 and FT4 levels showed a significant decrease, while the levels of serum TSH, TPOAb and TgAb were significantly increased in both 10 HI and 100 HI groups (p < .05).

CONCLUSION

In maternal rats, although normal thyroid function can be maintained following 10 HI, thyroiditis can be induced following 100 HI on lactation days 7, 14, and 21. In the offspring at PN180, hypothyroidism complicated with thyroiditis can occur in both the 10 HI and 100 HI groups.

Safety and biodistribution of sulfated archaeal glycolipid archaeosomes as vaccine adjuvants

Archaeosomes are liposomes comprised of ether lipids derived from various archaea. Unlike conventional ester-linked liposomes, archaeosomes exhibit high pH and thermal stability. As adjuvants, archaeosomes can induce robust, long-lasting humoral and cell-mediated immune responses and enhance protection in murine models of infectious disease and cancer. Archaeosomes constituted with total polar lipids (TPL) of various archaea are relatively complex, comprising >10 different lipid compounds. Archaeosomes can be constituted with semi-synthetic glycerolipids built on ether-linked isoprenoid phytanyl cores with varied synthetic glycol- and amino-head groups. However, such semi-synthetic archaeosomes involve many synthetic steps to arrive at the final desired glycolipid composition. We have developed a novel archaeosome formulation comprising a sulfated saccharide group covalently linked to the free sn-1 hydroxyl backbone of an archaeal core lipid (sulfated S-lactosylarchaeol, SLA) mixed with uncharged glycolipid (lactosylarchaeol, LA). This new class of adjuvants can be easily synthesized and retains strong immunostimulatory activity for induction of cell-mediated immunity following systemic immunization. Herein, we demonstrate the safety of SLA/LA archaeosomes following intramuscular injection to mice and evaluate the immunogenicity, in vivo distribution and cellular uptake of antigen (ovalbumin) encapsulated into SLA/LA archaeosomes. Overall, we have found that semi-synthetic sulfated glycolipid archaeosomes are a safe and effective novel class of adjuvants capable of inducing strong antigen-specific immune responses in mice and protection against subsequent B16 melanoma tumor challenge. A key step in their mechanism of action appears to be the recruitment of immune cells to the injection site and the subsequent trafficking of antigen to local draining lymph nodes.

Co-occurrence of second primary malignancy in patients with thyroid cancer

BACKGROUND

The discovery of asynchronous or synchronous double or multiple malignancies in patients is not uncommon. The co-occurrence of second primary malignancy (SPM) could be randomly occurring or association with risk factors such as environmental, genetic predisposition and therapy-related.

MATERIALS AND METHODS

We retrieved ∼782 million claim records consisting of 10.8 million males and 10.6 million females from Taiwan's National Health Insurance, which were collected for a period of 3 years (January 2000-December 2002). All the patient records were stratified by gender and ages at a 20-year interval with SPMs and specific groups. Interestingness or Q-value was used to measure strength of the disease-disease associations.

RESULTS

A total of 9423 thyroid cancer (female: 7483, male: 1940), 276 184 SPM (female: 141 023, male: 135 161) and 861 co-occurrence cases (female: 583, male: 278) were recorded. The co-occurrence incidence rate of head and neck, breast, digestive system and lung was 1.93%, 1.59%, 1.44% and 1.18%, respectively. Malignancy of salivary glands, laryngx, sarcoma, lymphoid tissue, mouth, central nervous system and lungs found Q-value >10. Malignancies with intermediate Q-values (5.0-9.9) were observed in nasopharynx, kidney and ureter, breast, stomach and skin. Prostate, leukemia, urinary bladder, ovary, colon, liver and uterine cervix cancer have lower Q-values (1.0-4.9).

CONCLUSION

Co-occurrence ratio of thyroid cancer and SPM was high, occurred in all organ systems. We postulated that the aggressive use of modern diagnostic modalities, aggressive radioiodine treatment, pre-existing molecular oncogen mutations, and thyroid hormone for simultaneously supple-mentary and suppressive therapies were responsible.

Abstract A247: BT2111, a new anticancer agent composed of trastuzumab and transcend a vector for brain delivery for the treatment of metastatic Her2+ breast cancer

Background: The blood-brain barrier (BBB) is mainly formed by brain capillary endothelial cells, which are closely sealed by tight junctions and express high levels of active efflux transport proteins, including P-glycoprotein (Pgp). As a result, the overwhelming majority of small molecules, proteins such as antibodies do not cross the BBB. For example, a humanized monoclonal antibody, trastuzumab improves survival of patients with metastatic breast cancer that overexpress HER2. However, the breast cancer frequently progresses in the CNS probably a result from poor brain penetration of trastuzumab. BT2111 made by incorporating Transcend (Melanotransferrin, MTf, p97) a brain delivery vector to trastuzumab was manufactured to provide a non-invasive and flexible platform for transporting an active agent into the brain.

Material and Methods: Brain distribution of Transcend, trastuzumab, and BT2111 was done by fluorescence confocal microscopy of brain slices after i.v. injection of rhodamine labeled molecules. Therapeutical efficacy was assessed in a mice model characterized by the formation of brain metastases after intracardiac administration of MDA-MB 231BR. A biweekly treatment was initiated on day 21 after the initial intracardiac injections. The efficacy of the different compounds was assessed by counting the number and size of metastases in brain at the termination of the experiment.

Results: We demonstrate that an antibody, trastuzumab, labelled with rhodamine can be transported in the brain parenchyma after incorporation of MTf. By quantitative confocal fluorescence microscopy we determined that 10 to 15 times more antibodies were delivered in the brain parenchyma when conjugated to MTf. It was found that BT2111 reduces by 68% the number of human HER2+ breast cancer metastases in the brain when compared to control animals with the remaining tumors being 57% smaller than those in the control animals. In contrast, trastuzumab alone had no effect on reducing the number of metastases and was associated with only a slight reduction in metastasis size when compared to untreated control animals.

Conclusion: Transcend (MTf, p97) a brain delivery vector can be used to transport large biologics such as mAbs, trastuzumab, at therapeutic concentration to the brain parenchyma for the treatment of brain cancers. BT2111 has the potential to become a new anticancer agent, BT2111, for treatment of brain metastases.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A247.

Citation Format: Reinhard Gabathuler, Timothy Z. Vitalis, Mohamed I. Nounou, Umar Iqbal, Maria Moreno, Chris E. Adkins, Tori O. Torrell, Wilfred A. Jefferies, Paul R. Lockman. BT2111, a new anticancer agent composed of trastuzumab and transcend a vector for brain delivery for the treatment of metastatic Her2+ breast cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A247.

Comparison of T2 and T2*-weighted MR molecular imaging of a mouse model of glioma

Background

Standard MRI has been used for high-grade gliomas detection, albeit with limited success as it does not provide sufficient specificity and sensitivity to detect complex tumor structure. Therefore targeted contrast agents based on iron oxide, that shorten mostly T2 relaxation time, have been recently applied. However pulse sequences for molecular imaging in animal models of gliomas have not been yet fully studied. The aim of this study was therefore to compare contrast-to-noise ratio (CNR) and explain its origin using spin-echo (SE), gradient echo (GE), GE with flow compensation (GEFC) as well as susceptibility weighted imaging (SWI) in T2 and T2* contrast-enhanced molecular MRI of glioma.

Methods

A mouse model was used. U87MGdEGFRvIII cells (U87MG), derived from a human tumor, were injected intracerebrally. A 9.4 T MRI system was used and MR imaging was performed on the 10 day after the inoculation of the tumor. The CNR was measured prior, 20 min, 2 hrs and 24 hrs post intravenous tail administration of glioma targeted paramagnetic nanoparticles (NPs) using SE, SWI, GE and GEFC pulse sequences.

Results

The results showed significant differences in CNR among all pulse sequences prior injection. GEFC provided higher CNR post contrast agent injection when compared to GE and SE. Post injection CNR was the highest with SWI and significantly different from any other pulse sequence.

Conclusions

Molecular MR imaging using targeted contrast agents can enhance the detection of glioma cells at 9.4 T if the optimal pulse sequence is used. Hence, the use of flow compensated pulse sequences, beside SWI, should to be considered in the molecular imaging studies.

mtDNA haplotypes differ in their probability of being eliminated by a mass die-off in an abundant seabird

In this study, we take advantage of a natural experiment--a 2004 mass die-off of the Common Murre in Alaska to determine whether closely related mtDNA haplotypes differ in their probability of being eliminated during such a short term but a marked event removing hundreds of thousands of individuals. We sequenced complete mtDNA ND2 gene (1041 bp) for 168 Common Murres sampled from seven breeding colonies across Alaska before the 2004 die-off and 127 dead murres washed ashore during the die-off. We found little mtDNA variation and lack of geographical structuring among the seven Common Murre breeding colonies in Alaska. A comparison of the single-dominant mtDNA haplotype's frequency between live murres sampled on breeding colonies before the die-off (73.2%; 95% confidence interval 66.3-79.9%) and dead murres sampled during the die-off (59.1%; 95% confidence interval 50.4-67.4%; Fisher's exact P=0.01) showed that carriers of the dominant haplotype were significantly less likely to die than carriers of other haplotypes. At the same time, the ratio of non-synonymous to synonymous substitutions did not differ between live (10:35) and dead birds (18:34; Fisher's exact P=0.26), indicating that non-synonymous substitutions were as likely to be eliminated as synonymous substitutions. These results are consistent with the possibility of positive selection on the dominant mtDNA haplotype during the die-off.

Evaluation of brain tumor vessels specific contrast agents for glioblastoma imaging

A mouse model of glioblastoma multiforme was used to determine the accumulation of a targeted contrast agent in tumor vessels. The contrast agent, consisting of superparamagnetic iron oxide coated with dextran, was functionalized with an anti-insulin-like-growth-factor binding protein 7 (anti-IGFBP7) single domain antibody. The near infrared marker, Cy5.5, was also attached for an in vivo fluorescence study. A 9.4T magnetic resonance imaging (MRI) system was used for in vivo studies on days 10 and 11 following tumor inoculation. T(2) relaxation time was used to measure the accumulation of the contrast agent in the tumor. Changes in tumor to brain contrast because of active targeting were compared with a nontargeted contrast agent. Effective targeting was confirmed with near infrared measurements and fluorescent microscopic analysis. The results showed that there was a statistically significant (P < .01) difference in normalized T(2) between healthy brain and tumor tissue 10 min, 1 h, and 2 h point postinjection of the anti-IGFBP7 single domain antibody targeted and nontargeted iron oxide nanoparticles. A statistical difference remained in animals treated with targeted nanoparticles 24 h postinjection only. The MRI, near infrared imaging, and fluorescent microscopy studies showed corresponding spatial and temporal changes. We concluded that the developed anti-IGFBP7-iron oxide single domain antibody-targeted MRI contrast agent selectively binds to abnormal vessels within a glioblastoma. T(2)-weighted MRI and near infrared imaging are able to detect the targeting effects in brain tumors.

FPGA-based real-time embedded system for RISS/GPS integrated navigation

Navigation algorithms integrating measurements from multi-sensor systems overcome the problems that arise from using GPS navigation systems in standalone mode. Algorithms which integrate the data from 2D low-cost reduced inertial sensor system (RISS), consisting of a gyroscope and an odometer or wheel encoders, along with a GPS receiver via a Kalman filter has proved to be worthy in providing a consistent and more reliable navigation solution compared to standalone GPS receivers. It has been also shown to be beneficial, especially in GPS-denied environments such as urban canyons and tunnels. The main objective of this paper is to narrow the idea-to-implementation gap that follows the algorithm development by realizing a low-cost real-time embedded navigation system capable of computing the data-fused positioning solution. The role of the developed system is to synchronize the measurements from the three sensors, relative to the pulse per second signal generated from the GPS, after which the navigation algorithm is applied to the synchronized measurements to compute the navigation solution in real-time. Employing a customizable soft-core processor on an FPGA in the kernel of the navigation system, provided the flexibility for communicating with the various sensors and the computation capability required by the Kalman filter integration algorithm.

Isolation of functional single domain antibody by whole cell immunization: implications for cancer treatment

Carcinoembryonic antigen related cell adhesion molecule (CEACAM) 6 is over-expressed in different types of cancer cells. In addition, it has also been implicated in some infectious diseases. Targeting this molecule by an antibody might have applications in diverse tumor models. Single domain antibody (sdAb) is becoming very useful format in antibody engineering as potential tools for treating acute and chronic disease conditions such as cancer for both diagnostic as well as therapeutic application. Generally, sdAbs with good affinity are isolated from an immune library. Discovery of a new target antigen would require a new immunization with purified antigen which is not always easy. In this study, we have isolated, by phage display, an sdAb against CEACAM6 with an affinity of 5 nM from a llama immunized with cancer cells. The antibody has good biophysical properties, and it binds to the cells expressing the target antigen. Furthermore, it reduces cancer cells proliferation in vitro and shows an excellent tumor targeting in vivo. This sdAb could be useful in diagnosis as well as therapy of CEACAM6 expressing tumors. Finally, we envisage it would be feasible to isolate good sdAbs against other interesting tumor associated antigens from this library. Therefore, this immunization method could be a general strategy for isolating sdAbs against any surface antigen without immunizing the animal with the antigen of interest each time.