Multispectral Photoacoustic Imaging of Tumor Protease Activity with a Gold Nanocage-Based Activatable Probe

Purpose

Tumor proteases have been recognized as significant regulators in the tumor microenvironment, but the current strategies for in vivo protease imaging have tended to focus on the development of a probe design rather than the investigation of a novel imaging strategy by leveraging the imaging technique and probe. Herein, it is the first report to investigate the ability of multispectral photoacoustic imaging (PAI) to estimate the distribution of protease cleavage sites inside living tumor tissue by using an activatable photoacoustic (PA) probe.

Procedures

The protease MMP-2 is selected as the target. In this probe, gold nanocages (GNCs) with an absorption peak at ~?800 nm and fluorescent dye molecules with an absorption peak at ~?680 nm are conjugated via a specific enzymatic peptide substrate. Upon enzymatic activation by MMP-2, the peptide substrate is cleaved and the chromophores are released. Due to the different retention speeds of large GNCs and small dye molecules, the probe alters its intrinsic absorption profile and produces a distinct change in the PA signal. A multispectral PAI technique that can distinguish different chromophores based on intrinsic PA spectral signatures is applied to estimate the signal composition changes and indicate the cleavage interaction sites. Finally, the multispectral PAI technique with the activatable probe is tested in solution, cultured cells, and a subcutaneous tumor model in vivo.

Results

Our experiment in solution with enzyme ± inhibitor, cell culture ± inhibitor, and in vivo tumor model with administration of the developed probe ± inhibitor demonstrated the probe was cleaved by the targeted enzyme. Particularly, the in vivo estimation of the cleavage site distribution was validated with the result of ex vivo immunohistochemistry analysis.

Conclusions

This novel synergy of the multispectral PAI technique and the activatable probe is a potential strategy for the distribution estimation of tumor protease activity in vivo.

     

Selecting Tumor-Specific Molecular Targets in Pancreatic Adenocarcinoma: Paving the Way for Image-Guided Pancreatic Surgery

Purpose

The purpose of this study was to identify suitable molecular targets for tumor-specific imaging of pancreatic adenocarcinoma.

Procedures

The expression of eight potential imaging targets was assessed by the target selection criteria (TASC)—score and immunohistochemical analysis in normal pancreatic tissue (n?=?9), pancreatic (n?=?137), and periampullary (n?=?28) adenocarcinoma.

Results

Integrin α_vβ₆, carcinoembryonic antigen (CEA), epithelial growth factor receptor (EGFR), and urokinase plasminogen activator receptor (uPAR) showed a significantly higher (all p?<?0.001) expression in pancreatic adenocarcinoma compared to normal pancreatic tissue and were confirmed by the TASC score as promising imaging targets. Furthermore, these biomarkers were expressed in respectively 88 %, 71 %, 69 %, and 67 % of the pancreatic adenocarcinoma patients.

Conclusions

The results of this study show that integrin α_vβ₆, CEA, EGFR, and uPAR are suitable targets for tumor-specific imaging of pancreatic adenocarcinoma.

     

Intraoperative Molecular Imaging of Lung Adenocarcinoma Can Identify Residual Tumor Cells at the Surgical Margins

Purpose

During lung surgery, identification of surgical margins is challenging. We hypothesized that molecular imaging with a fluorescent probe to pulmonary adenocarcinomas could enhance residual tumor during resection.

Procedures

Mice with flank tumors received a contrast agent targeting folate receptor alpha. Optimal dose and time of injection was established. Margin detection was compared using traditional methods versus molecular imaging. A pilot study was then performed in three humans with lung adenocarcinoma.

Results

The peak tumor-to-background ratio (TBR) of murine tumors was 3.9. Fluorescence peaked at 2 h and was not improved beyond 0.1 mg/kg. Traditional inspection identified 30 % of mice with positive margins. Molecular imaging identified an additional 50 % of residual tumor deposits (p?<?0.05). The fluorescent probe visually enhanced all human tumors with a mean TBR of 3.5.

Conclusions

Molecular imaging is an important adjunct to traditional inspection to identify surgical margins after tumor resection.

     

Olanzapine vs haloperidol: treating delirium in a critical care setting

Objective

To compare the safety and estimate the response profile of olanzapine, a second-generation antipsychotic, to haloperidol in the treatment of delirium in the critical care setting.

Design

Prospective randomized trial

Setting

Tertiary care university affiliated critical care unit.

Patients

All admissions to a medical and surgical intensive care unit with a diagnosis of delirium.

Interventions

Patients were randomized to receive either enteral olanzapine or haloperidol.

Measurements

Patient’s delirium severity and benzodiazepine use were monitored over 5 days after the diagnosis of delirium.

Main results

Delirium Index decreased over time in both groups, as did the administered dose of benzodiazepines. Clinical improvement was similar in both treatment arms. No side effects were noted in the olanzapine group, whereas the use of haloperidol was associated with extrapyramidal side effects.

Conclusions

Olanzapine is a safe alternative to haloperidol in delirious critical care patients, and may be of particular interest in patients in whom haloperidol is contraindicated.

     

Multimodality Imaging of Cancer Superoxide Anion Using the Small Molecule Coelenterazine

Purpose

We evaluated the small molecule coelenterazine as a potential reporter of cancer-associated superoxide anion in cell culture and in mice.

Procedures

The superoxide anion concentrations of various cancer cell lines were quantified by coelenterazine chemiluminescence in vitro. Coelenteramide fluorescence was detected via flow cytometry and fluorescent microscopy. Coelenterazine was used for the in vivo detection of cancer-associated superoxide anion using the 4T1 breast adenocarcinoma mouse model.

Results

Various cell lines in culture demonstrated different superoxide anion concentrations, with a signal range of 3.15?±?0.06 to 11.80?±?0.24 times that of background. In addition to chemiluminescent detection of coelenterazine, we demonstrated fluorescent detection of coelenteramide within the cytoplasm of cells. 4T1 murine mammary adenocarcinoma tumors in mice demonstrated significantly higher 2.13?±?0.19-fold coelenterazine-based chemiluminescence than that of surrounding normal tissues.

Conclusions

Collectively, our results indicate that coelenterazine can be used to assay superoxide anion concentrations in cultured cancer cells and in tumors growing in mice.

     

Dynamic Measurement of Tumor Vascular Permeability and Perfusion using a Hybrid System for Simultaneous Magnetic Resonance and Fluorescence Imaging

Purpose

Assessing tumor vascular features including permeability and perfusion is essential for diagnostic and therapeutic purposes. The aim of this study was to compare fluorescence and magnetic resonance imaging (MRI)-based vascular readouts in subcutaneously implanted tumors in mice by simultaneous dynamic measurement of tracer uptake using a hybrid fluorescence molecular tomography (FMT)/MRI system.

Procedure

Vascular permeability was measured using a mixture of extravascular imaging agents, GdDOTA and the dye Cy5.5, and perfusion using a mixture of intravascular agents, Endorem and a fluorescent probe (Angiosense). Dynamic fluorescence reflectance imaging (dFRI) was integrated into the hybrid system for high temporal resolution.

Results

Excellent correspondence between uptake curves of Cy5.5/GdDOTA and Endorem/Angiosense has been found with correlation coefficients R?>?0.98. The two modalities revealed good agreement regarding permeability coefficients and centers-of-gravity of the imaging agent distribution.

Conclusion

The FMT/dFRI protocol presented is able to accurately map physiological processes and poses an attractive alternative to MRI for characterizing tumor neoangiogenesis.

     

Pooled Aquablation Results for American Men with Lower Urinary Tract Symptoms due to Benign Prostatic Hyperplasia in Large Prostates (60–150 cc)

Introduction

To present short-term safety and efficacy data of men with lower urinary tract symptoms (LUTS) secondary to benign prostatic hyperplasia (BPH) treated with Aquablation.

Methods

Men with LUTs secondary to BPH (60–150 cc) underwent Aquablation treatment from February 2016 to December 2017 across 17 investigational sites in the USA from two contemporary investigational device exemption (IDE) studies called WATER (NCT02505919) and WATER II (NCT03123250).

Results

One hundred seven males with mean age of 67.3?±?6.5 years were treated with Aquablation; mean prostate volume was 99.4?±?24.1 cc. The pooled results show that large prostates have an average procedure time of less than 36 min and discharge on average 1.6?±?1 days. The IPSS decreased by 16.7?±?8.1 points at 3 months and Q_max increased by 11.2?±?12.4 ml/s. The Clavien-Dindo (CD) grade 2 or higher event rate at 3 months was 29%. A non-hierarchical breakdown for CD events yielded 18% grade 2 and 19% grade 3 or higher.

Conclusion

Men with LUTS secondary to BPH (60–150 cc) in a pooled analysis were treated safely and effectively with Aquablation up to 3 months postoperatively.

Trial Registration

ClinicalTrials.gov identifiers, NCT02505919 and NCT03123250.

Funding

PROCEPT BioRobotics.

     

Automatic adjustment of pressure support by a computer-driven knowledge-based system during noninvasive ventilation: a feasibility study

Objective

To evaluate the feasibility of using a knowledge-based system designed to automatically titrate pressure support (PS) to maintain the patient in a “respiratory comfort zone” during noninvasive ventilation (NIV) in patients with acute respiratory failure.

Design and setting

Prospective crossover interventional study in an intensive care unit of a university hospital.

Patients

Twenty patients.

Interventions

After initial NIV setting and startup in conventional PS by the chest physiotherapist NIV was continued for 45?min with the automated PS activated.

Measurements and results

During automated PS minute-volume was maintained constant while respiratory rate decreased significantly from its pre-NIV value (20?±?3 vs. 25?±?3?bpm). There was a trend towards a progressive lowering of dyspnea. In hypercapnic patients PaCO₂ decreased significantly from 61?±?9 to 51?±?2?mmHg, and pH increased significantly from 7.31?±?0.05 to 7.35?±?0.03. Automated PS was well tolerated. Two system malfunctions occurred prompting physiotherapist intervention.

Conclusions

The results of this feasibility study suggest that the system can be used during NIV in patients with acute respiratory failure. Further studies should now determine whether it can improve patient-ventilator interaction and reduce caregiver workload.

     

Prone equals prone? Impact of positioning techniques on respiratory function in anesthetized and paralyzed healthy children

Objectives

Although the prone position is effectively used to improve oxygenation, its impact on functional residual capacity is controversial. Different techniques of body positioning might be an important confounding factor. The aim of this study was to determine the impact of two different prone positioning techniques on functional residual capacity and ventilation distribution in anesthetized, preschool-aged children.

Design

Functional residual capacity and lung clearance index, a measure of ventilation homogeneity, were calculated using a sulfur-hexafluoride multibreath washout technique. After intubation, measurements were taken in the supine position and, in random order, in the flat prone position and the augmented prone position (gel pads supporting the pelvis and the upper thorax).

Setting

Pediatric anesthesia unit of university hospital.

Patients and participants

Thirty preschool children without cardiopulmonary disease undergoing elective surgery.

Measurements and results

Mean (range) age was 48.5 (24–80) months, weight 17.2 (10.5–26.9)?kg, functional residual capacity (mean ±?SD) 22.9?±?6.2?ml.kg ^?1 in the supine position and 23.3?±?5.6?ml.kg ^?1 in the flat prone position, while lung clearance indices were 8.1?±?2.3 vs. 7.9?±?2.3, respectively. In contrast, functional residual capacity increased to 27.6 ± 6.5 ml.kg ^?1 (pp

Conclusions

Functional residual capacity and ventilation distribution were similar in the supine and flat prone positions, while these parameters improved significantly in the augmented prone position, suggesting that the technique of prone positioning has major implications for pulmonary function.

     

Validity of the diagnosis of a single depressive episode in a case register

Objective

To validate the ICD-10 diagnosis of a single depressive episode as used in daily clinical psychiatric practice and as recorded in the Danish Psychiatric Central Research Register.

Methods

Patients discharged with a diagnosis of a single depressive episode were consecutively sampled from the register and diagnosed according to an interview using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN).

Results

A total of 75.4% of 399 patients with a register diagnosis of a single depressive episode also got this diagnosis according to the SCAN interview (82.8% for severe type of a single depression, 76.0% for moderate type of a single depression and 65.2% for mild type of a single depression).

Conclusion

The ICD-10 diagnosis of a single depressive episode can be used in daily clinical practice with sufficient precision. The validity of the diagnosis is highest for severe and moderate type of depression and decreases for mild depression.

     

Evaluation of Quantitative Imaging Biomarkers in the DSS Colitis Model

Purpose

In humans, colonoscopy is the gold standard for the diagnosis of inflammatory changes of the colon wall. Aim of this study was the identification of less invasive imaging biomarkers in the dextran sodium sulfate (DSS) colitis model to provide additional information on transmural changes of the colon wall.

Procedures

Colitis was induced in C57BL/6 mice by administration of 2, 3, and 4 % DSS over a period of 5 days. Colon wall thickness was measured using magnetic resonance imaging (MRI), ultrasound (US), and x-ray computed tomography (CT), gut inflammation by positron emission tomography/CT, and mucosal changes of the colon wall by colonoscopy. Colon samples were examined histologically.

Results

MRI, CT, US, and histological data revealed increased colon wall thickness in DSS-treated mice compared to healthy controls. Elevated 2-deoxy-2[¹⁸F]fluoro-d-glucose uptake and colonoscopy confirmed high inflammatory load in the guts of colitis mice.

Conclusions

The established quantitative imaging readouts offer promising perspectives to develop new compounds and to translate these methods into the clinical setting.

     

Early nontumorous CT findings after irreversible electroporation of locally advanced pancreatic cancer

Purpose

The use of irreversible electroporation (IRE) has been a relatively recent development in the palliative treatment of locally advanced pancreatic cancer. With CT as a key modality in patient follow-up, recognition of nontumorous imaging findings is paramount after IRE.

Methods

A retrospective review of patients having undergone IRE for locally advanced pancreatic adenocarcinoma was performed. A total of 36 patients met inclusion criteria and their imaging studies were reviewed by two radiologists. Nontumorous abnormalities identified in the peri-electroporation bed on Computed Tomography (CT) during the early postoperative period (within 30 days) were characterized and classified into categories.

Results

Our results indicate that the most common nontumorous findings in the peri-electroporation bed were vascular, followed by changes involving the gastrointestinal tract, peritoneal cavity, and, infrequently, the biliary tree.

Conclusions

Interpretation of CT imaging of the postoperative peri-electroporation bed is challenging. This review of CT findings allows the radiologist to recognize and anticipate significant nontumorous findings in the peri-electroporation bed during early follow-up after IRE.

     

Quantitative [<Superscript>18</Superscript>F]FMISO PET Imaging Shows Reduction of Hypoxia Following Trastuzumab in a Murine Model of HER2+ Breast Cancer

Purpose

Evaluation of [¹⁸F]fluoromisonidazole ([¹⁸F]FMISO)-positron emission tomography (PET) imaging as a metric for evaluating early response to trastuzumab therapy with histological validation in a murine model of HER2+ breast cancer.

Procedures

Mice with BT474, HER2+ tumors, were imaged with [¹⁸F]FMISO-PET during trastuzumab therapy. Pimonidazole staining was used to confirm hypoxia from imaging.

Results

[¹⁸F]FMISO-PET indicated significant decreases in hypoxia beginning on day 3 (P?<?0.01) prior to changes in tumor size. These results were confirmed with pimonidazole staining on day 7 (P?<?0.01); additionally, there was a significant positive linear correlation between histology and PET imaging (r ² ?=?0.85).

Conclusions

[¹⁸F]FMISO-PET is a clinically relevant modality which provides the opportunity to (1) predict response to HER2+ therapy before changes in tumor size and (2) identify decreases in hypoxia which has the potential to guide subsequent therapy.

     

Hypoxia-Targeting Fluorescent Nanobodies for Optical Molecular Imaging of Pre-Invasive Breast Cancer

Purpose

The aim of this work was to develop a CAIX-specific nanobody conjugated to IRDye800CW for molecular imaging of pre-invasive breast cancer.

Procedures

CAIX-specific nanobodies were selected using a modified phage display technology, conjugated site-specifically to IRDye800CW and evaluated in a xenograft breast cancer mouse model using ductal carcinoma in situ cells (DCIS).

Results

Specific anti-CAIX nanobodies were obtained. Administration of a CAIX-specific nanobody into mice with DCIS xenografts overexpressing CAIX showed after 2 h a mean tumor-to-normal tissue ratio (TNR) of 4.3?±?0.6, compared to a TNR of 1.4?±?0.2 in mice injected with the negative control nanobody R2-IR. In DCIS mice, a TNR of 1.8?±?0.1 was obtained. Biodistribution studies demonstrated an uptake of 14.0?±?1.1 %I.D./g in DCIS?+?CAIX tumors, 4.6?±?0.8 %I.D./g in DCIS tumors, while 2.0?±?0.2 %I.D./g was obtained with R2-IR.

Conclusions

These results demonstrate the successful generation of a CAIX-specific nanobody-IRDye800CW conjugate that can be used for rapid imaging of (pre-)invasive breast cancer.

     

Estimating Long-Term Survival of Adults with Philadelphia Chromosome-Negative Relapsed/Refractory B-Precursor Acute Lymphoblastic Leukemia Treated with Blinatumomab Using Historical Data

Introduction

Blinatumomab is a bispecific T cell-engaging antibody construct indicated for adult patients with relapsed/refractory (R/R) Ph(?) B-precursor acute lymphoblastic leukemia (ALL), an aggressive disease with poor prognosis. A phase 2 single-arm clinical study showed that 43% of patients achieved CR/CRh within two cycles and approximately 20% of patients receiving blinatumomab were still alive after 2 years.

Methods

The objective of the current analysis was to estimate long-term survival of patients receiving blinatumomab beyond the observed time period in the clinical study using a large historical observational dataset. Conditional survival probabilities of blinatumomab-treated patients beyond month 60 were assumed to be the same as the US general population.

Results

At month 60, the estimated proportion of blinatumomab-treated patients alive was more than double that of historical patients (12.6% vs 5.4%). The mean overall survival was 76.1 months for blinatumomab patients and 39.8 months for historical patients. Sensitivity analyses including additional follow-up data from the clinical study showed consistent results.

Conclusions

These findings suggest that blinatumomab provides substantial overall survival benefit to patients with (R/R) Ph(?) B-precursor ALL compared with salvage chemotherapy.

Funding

Amgen.

Trial Registration

ClinicalTrials.gov identifier NCT01466179 and NCT02003612.

     

Lack of agreement between thermodilution and electrical velocimetry cardiac output measurements

Objective

The modified algorithm for the non-invasive determination of cardiac output (CO) by electrical bioimpedance—electrical velocimetry (EV^®)—has been reported to give reliable results in comparison with echocardiography and pulmonary arterial thermodilution (PA-TD) in patients either before or after cardiac surgery. The present study was designed to determine whether EV^®-CO measurements reflect intraindividual changes in CO during cardiac surgery.

Design

Prospective, observational study.

Setting

Operating room (OR) and intensive care unit (ICU) of a university hospital.

Patients

Twenty-nine patients undergoing elective cardiac surgery.

Interventions

None.

Measurements

CO was determined simultaneously by PA-TD and EV^® after induction of anesthesia (t1) and 4.9?±?3.5?h after ICU admission (t2).

Results

TD-CO was 3.9?±?1.4 and 5.4?±?1.1 l/min at t1 and t2 (?p?®-CO was 4.3?±?1.1 and 4.9?±?1.5 l/min at t1 and t2 (?p?=?0.013). Bland–Altman analysis showed a bias of ?0.4 l/min and 0.4 l/min and a precision of 3.2 and 3.6 l/min (34.3% and 67.4%) at t1 and t2, respectively. Analysis of the individual pre- to postoperative changes in CO with both methods revealed bidirectional changes in n?=?12 patients and unidirectional changes with a difference greater than 50% and less than 50% in n?=?9 and n?=?8 patients, respectively.

Conclusions

The disagreement between PA-TD and EV^®-CO measurements after anesthesia induction and after ICU admission, as well as the fact that thoracic bioimpedance did not adequately reflect pre- to postoperative changes in CO, questions the reliability of EV^®-CO measurements in cardiac surgery patients and contrasts sharply with previous studies.

     

Determination of functional residual capacity by oxygen washin-washout: a validation study

Objective

To validate a new system for functional residual capacity (FRC) measurements using oxygen washin/washout in spontaneously breathing humans. The system (LUFU, Drägerwerk AG, Lübeck, Germany) consists of an unmodified EVITA 4 ventilator, a side-stream paramagnetic oxygen sensor and a dedicated software.

Design

Laboratory study and measurements in spontaneously breathing volunteers.

Setting

Pulmonary function laboratory of a university hospital.

Participants

20 healthy and 15 lung diseased volunteers.

Interventions

FRC was measured by LUFU (LUFU-FRC) and by helium dilution (He-FRC); intra-thoracic gas volume (ITGV) was determined by body plethysmography. Each measurement cycle consisted of four independent LUFU-FRC determinations (step change of FiO₂ from 0.21 to 0.5 and back and from 0.21 to 1.0 and back), two helium-dilution runs and two body box measurements. Repeatability and agreement between methods were determined by comparing different measurements of one technique and by comparing different techniques among each other.

Measurements and results

Repeatability of LUFU-FRC was estimated by comparing washin to washout and the different FiO₂steps. The difference of the means was 3.7% at the most. Agreement between methods resulted in the following differences (mean?±?standard deviation of differences) for healthy and lung-diseased volunteers, respectively: LUFU-FRC vs. He-FRC –0.40?±?0.50?L (0.02?±?0.95?L), LUFU-FRC vs. ITGV –0.43?±?0.54?L (–0.18?±?0.61?L) and He-FRC vs. ITGV –0.03?±?0.43?L (–0.20?±?0.98?L).

Conclusions

LUFU is a non-invasive method for the determination of FRC that requires only minor additional equipment and no modification to the ventilator. It can be used in difficult conditions such as breathing patterns with variations from breath to breath. The results of this study show that LUFU is sufficiently reliable and repeatable to warrant its clinical application.

     

Low dose quetiapine induced galactorrhoea: a case report

Background

Quetiapine causes less prolactin elevation and/or galactorrhoea than other atypical antipsychotics.

Case Presentation

Ms AB had galactorrhoea and raised prolactin levels at only 100 mg of quetiapine daily.

Conclusion

Low dose quetiapine can also cause galactorrhoea.

     

Predictive factors for polypharmacy among child and adolescent psychiatry inpatients

Background

Aim was to determine the predictive factors for polypharmacy among inpatient children and adolescents with psychiatric disorders.

Methods

Blinded, case-note review of children and adolescents with ICD 10 diagnosis of psychiatric disorders on psychotropic medication was conducted. Data on demography, illness, and treatment was analyzed with univariate and multivariate techniques.

Results

Proscribing non-pharmacological interventions (OR = 4.7) and pro re nata medication (OR = 3.3), increased the risk of polypharmacy. Prescribing physical restraint reduced the risk of receiving multiple medications (OR = 0.3).

Conclusion

Proscribing non-pharmacological interventions, pro re nata medication and physical restraints increased polypharmacy.

     

Using Patient Feedback to Optimize the Design of a Certolizumab Pegol Electromechanical Self-Injection Device: Insights from Human Factors Studies

Introduction

We incorporated patient feedback from human factors studies (HFS) in the patient-centric design and validation of ava^®, an electromechanical device (e-Device) for self-injecting the anti-tumor necrosis factor certolizumab pegol (CZP).

Methods

Healthcare professionals, caregivers, healthy volunteers, and patients with rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, or Crohn’s disease participated in 11 formative HFS to optimize the e-Device design through intended user feedback; nine studies involved simulated injections. Formative participant questionnaire feedback was collected following e-Device prototype handling. Validation HFS (one EU study and one US study) assessed the safe and effective setup and use of the e-Device using 22 predefined critical tasks. Task outcomes were categorized as “failures” if participants did not succeed within three attempts.

Results

Two hundred eighty-three participants entered formative (163) and validation (120) HFS; 260 participants performed one or more simulated e-Device self-injections. Design changes following formative HFS included alterations to buttons and the graphical user interface screen. All validation HFS participants completed critical tasks necessary for CZP dose delivery, with minimal critical task failures (12 of 572 critical tasks, 2.1%, in the EU study, and 2 of 5310 critical tasks, less than 0.1%, in the US study).

Conclusion

CZP e-Device development was guided by intended user feedback through HFS, ensuring the final design addressed patients’ needs. In both validation studies, participants successfully performed all critical tasks, demonstrating safe and effective e-Device self-injections.

Funding

UCB Pharma.

Plain Language Summary

Plain language summary available on the journal website.