Organic Electronic Platform for Real-Time Phenotypic Screening of Extracellular-Vesicle-Driven Breast Cancer Metastasis

Tumor-derived extracellular vesicles (TEVs) induce the epithelial-to-mesenchymal transition (EMT) in nonmalignant cells to promote invasion and cancer metastasis, representing a novel therapeutic target in a field severely lacking in efficacious antimetastasis treatments. However, scalable technologies that allow continuous, multiparametric monitoring for identifying metastasis inhibitors are absent. Here, the development of a functional phenotypic screening platform based on organic electrochemical transistors (OECTs) for real-time, noninvasive monitoring of TEV-induced EMT and screening of antimetastatic drugs is reported. TEVs derived from the triple-negative breast cancer cell line MDA-MB-231 induce EMT in nonmalignant breast epithelial cells (MCF10A) over a nine-day period, recapitulating a model of invasive ductal carcinoma metastasis. Immunoblot analysis and immunofluorescence imaging confirm the EMT status of TEV-treated cells, while dual optical and electrical readouts of cell phenotype are obtained using OECTs. Further, heparin, a competitive inhibitor of cell surface receptors, is identified as an effective blocker of TEV-induced EMT. Together, these results demonstrate the utility of the platform for TEV-targeted drug discovery, allowing for facile modeling of the transient drug response using electrical measurements, and provide proof of concept that inhibitors of TEV function have potential as antimetastatic drug candidates.

Dual Mode Sensing of Binding and Blocking of Cancer Exosomes to Biomimetic Human Primary Stem Cell Surfaces

Cancer-derived exosomes (cEXOs) facilitate transfer of information between tumor and human primary stromal cells, favoring cancer progression. Although the mechanisms used during this information exchange are still not completely understood, it is known that binding is the initial contact established between cEXOs and cells. Hence, studying binding and finding strategies to block it are of great therapeutic value. However, such studies are challenging for a variety of reasons, including the need for human primary cell culture, the difficulty in decoupling and isolating binding from internalization and cargo delivery, and the lack of techniques to detect these specific interactions. In this work, we created a supported biomimetic stem cell membrane incorporating membrane components from human primary adipose-derived stem cells (ADSCs). We formed the supported membrane on glass and on multielectrode arrays to offer the dual option of optical or electrical detection of cEXO binding to the membrane surface. Using our platform, we show that cEXOs bind to the stem cell membrane and that binding is blocked when an antibody to integrin β1, a component of ADSC surface, is exposed to the membrane surface prior to cEXOs. To test the biological outcome of blocking this interaction, we first confirm that adding cEXOs to cultured ADSCs leads to the upregulation of vascular endothelial growth factor, a measure of proangiogenic activity. Next, when ADSCs are first blocked with anti-integrin β1 and then exposed to cEXOs, the upregulation of proangiogenic activity and cell proliferation are significantly reduced. This biomimetic membrane platform is the first cell-free label-free in vitro platform for the recapitulation and study of cEXO binding to human primary stem cells with potential for therapeutic molecule screening as it is compatible with scale-up and multiplexing.

Supported Membrane Platform to Assess Surface Interactions between Extracellular Vesicles and Stromal Cells

Extracellular vesicles (EVs) are membrane-encapsulated particles secreted by eukaryotic cells that stimulate cell communication and horizontal cargo exchange. EV interactions with stromal cells can result in molecular changes in the recipient cell and, in some cases, lead to disease progression. However, mechanisms leading to these changes are poorly understood. A few model systems are available for studying the outcomes of surface interactions between EV membranes with stromal cells. Here, we created a hybrid supported bilayer incorporating EVs membrane material, called an extracellular vesicle supported bilayer, EVSB. Using EVSBs, we investigated the surface interactions between breast cancer EVs and adipose-derived stem cells (ADSCs) by culturing ADSCs on EVSBs and analyzing cell adhesion, spreading, viability, vascular endothelial growth factor (VEGF) secretion, and myofibroblast differentiation. Results show that cell viability, adhesion, spreading, and proangiogenic activity were enhanced, conditions that promote oncogenic activity, but cell differentiation was not. This model system could be used to develop therapeutic strategies to limit EV-ADSC interactions and proangiogenic conditions. Finally, this model system is not limited to the study of cancer but can be used to study surface interactions between EVs from any origin and any target cell to investigate EV mechanisms leading to cellular changes in other diseases.

Reproducible in vitro model for dystrophic calcification of cardiac valvular interstitial cells: insights into the mechanisms of calcific aortic valvular disease

Calcific aortic valvular disease (CAVD) is the most prevalent valvular pathology in the United States. Development of a pharmacologic agent to slow, halt, or reverse calcification has proven to be unsuccessful as still much remains unknown about the mechanisms of disease initiation. Although in vitro models of some features of CAVD exist, their utility is limited by the inconsistency of the size and time course of the calcified cell aggregates. In this study, we introduce and verify a highly reproducible in vitro method for studying dystrophic calcification of cardiac valvular interstitial cells, considered to be a key mechanism of clinical CAVD. By utilizing micro-contact printing, we were able to consistently reproduce cell aggregation, myofibroblastic markers, programmed cell death, and calcium accumulation within aggregates of 50-400 μm in diameter on substrates with moduli from 9.6 to 76.8 kPa. This method is highly repeatable, with 70% of aggregates staining positive for Alizarin Red S after one week in culture. Dense mineralized calcium-positive nanoparticles were found within the valvular interstitial cell aggregates as shown by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The area of micro-contact printed aggregates staining positive for caspase 3/7 activity increased from 5.9 ± 0.9% to 12.6 ± 4.5% over one week in culture. Z-VAD-FMK reduced aggregates staining positive for Alizarin Red S by 60%. The state of cell stress is hypothesized to play a role in the disease progression; traction force microscopy indicates high substrate stresses along the aggregate periphery which can be modulated by altering the size of the aggregates and the modulus of the substrate. Micro-contact printing is advantageous over the currently used in vitro model as it allows the independent study of how cytokines, substrate modulus, and pharmacologic agents affect calcification. This controlled method for aggregate creation has the potential to be used as an in vitro assay for the screening of promising therapeutics to mitigate CAVD.

A practical approach to investigating a man with a raised prostate-specific antigen in the modern era

Urologists in the UK are encouraged to follow the National Institute for Health and Care Excellence (NICE) guidelines for patient management. In 2014, members of the British Association of Urological Surgeons (BAUS) were asked in a survey what diagnostic pathway they would follow for themselves or their relatives if they had a raised prostate-specific antigen (PSA). It was found that only a quarter would follow NICE guidance. The current recommendations rely on pathological assessment of prostate tissue obtained at a transrectal ultrasound guided biopsy. Increasing evidence indicates that pre-biopsy multiparametric magnetic resonance imaging (mp-MRI) coupled with targeted biopsy approaches outperform random biopsies in the detection of clinically significant disease. Herein we discuss the role of magnetic resonance imaging and targeted biopsy approaches to diagnose prostate cancer in the modern era.

Feasibility of a high-speed gamma-camera design using the high-yield-pileup-event-recovery method

Higher count-rate gamma cameras than are currently used are needed if the technology is to fulfill its promise in positron coincidence imaging, radionuclide therapy dosimetry imaging, and cardiac first-pass imaging. The present single-crystal design coupled with conventional detector electronics and the traditional Anger-positioning algorithm hinder higher count-rate imaging because of the pileup of gamma-ray signals in the detector and electronics. At an interaction rate of 2 million events per second, the fraction of nonpileup events is < 20% of the total incident events. Hence, the recovery of pileup events can significantly increase the count-rate capability, increase the yield of imaging photons, and minimize image artifacts associated with pileups. A new technology to significantly enhance the performance of gamma cameras in this area is introduced.

METHODS

We introduce a new electronic design called high-yield-pileup-event-recovery (HYPER) electronics for processing the detector signal in gamma cameras so that the individual gamma energies and positions of pileup events, including multiple pileups, can be resolved and recovered despite the mixing of signals. To illustrate the feasibility of the design concept, we have developed a small gamma-camera prototype with the HYPER-Anger electronics. The camera has a 10 x 10 x 1 cm NaI(Tl) crystal with four photomultipliers. Hot-spot and line sources with very high 99mTc activities were imaged. The phantoms were imaged continuously from 60,000 to 3,500,000 counts per second to illustrate the efficacy of the method as a function of counting rates.

RESULTS

At 2-3 million events per second, all phantoms were imaged with little distortion, pileup, and dead-time loss. At these counting rates, multiple pileup events (> or = 3 events piling together) were the predominate occurrences, and the HYPER circuit functioned well to resolve and recover these events. The full width at half maximum of the line-spread function at 3,000,000 counts per second was 1.6 times that at 60,000 counts per second.

CONCLUSION

This feasibility study showed that the HYPER electronic concept works; it can significantly increase the count-rate capability and dose efficiency of gamma cameras. In a larger clinical camera, multiple HYPER-Anger circuits may be implemented to further improve the imaging counting rates that we have shown by multiple times. This technology would facilitate the use of gamma cameras for radionuclide therapy dosimetry imaging, cardiac first-pass imaging, and positron coincidence imaging and the simultaneous acquisition of transmission and emission data using different isotopes with less cross-contamination between transmission and emission data.

Unique clinical presentation of pediatric shunt malfunction

INTRODUCTION

A cerebrospinal fluid (CSF) shunt is the primary treatment for most etiologies of hydrocephalus in the pediatric population. Malfunction of the shunt may present with unique symptoms and signs. This retrospective review investigates the presenting signs and symptoms of pediatric patients with shunt malfunction. Clinical

MATERIAL AND METHOD

One-hundred-and-thirty CSF diversion procedures were performed at two affiliated pediatric hospitals over a 2-year period. Seventy consecutive cases of CSF shunt revision were reviewed. These 70 operations were performed on 65 patients. Their medical records and radiographic studies were reviewed, and supplemented with a telephone interview to obtain a minimum of 3 months follow-up.

RESULTS

The 65 patients' age ranged from 3 months to 16 years. The original etiology of the hydrocephalus was Chiari II malformation in 17, idiopathic in 15 and intraventricular hemorrhage in 10, neoplasm in 8 patients and meningitis in 5 patients. The most frequent presenting symptoms were headache (39 admissions), nausea/vomiting (28) and drowsiness (21). Seven Chiari patients (41%) presented with neck pain, 2 (12%) presented with lower cranial nerve palsy, and 2 (12%) presented with symptomatic syrinx, complaints not reported by non-Chiari patients (p < 0.01, chi2 analysis). Four myelodysplastic patients presented with a new-onset or recurrent seizure episode, which was significantly more frequent than in nonmyelodysplastic patients (p < 0.05, chi2 analysis). On examination, increased head circumference was noted in 17 patients. Parinaud's syndrome was noted more prominently in patients with a history of intracranial neoplasm (4 of 8 cases) than in patients with nonneoplastic diseases (2 of 62 cases; p < 0.05, chi2 analysis). Other interesting presenting signs were pseudocyst (2), syringomyelia (2), hemiparesis (2) and Parkinson-like rigidity (2).

CONCLUSION

Pediatric shunt malfunction generally presents with headache, nausea/vomiting, altered mental status, increased head circumference and bulging fontanelle. Other less frequent but unique presenting signs and symptoms, such as neck pain, syringomyelia and lower cranial nerve palsy in the myelodysplastic population, and Parinaud's syndrome in patients with a history of intracranial neoplasm are frequently associated with shunt malfunction and should prompt a radiographic workup.

The incidence of Hill-Sachs lesions in initial anterior shoulder dislocations

We undertook a prospective study using arthroscopy to determine the intraarticular derangement caused by initial anterior shoulder dislocations. Of our 32 patients, 15 (47%) had a grade I, grade II, or grade III Hill-Sachs lesion. The patients were 29 men and 3 women whose ages ranged from 15 to 28 years (mean 22 years). All of the patients studied were United States military personnel or members of their families. None of the patients had had prior injuries of the affected shoulder, and all underwent arthroscopy within 72 h of injury. Few reports describe a Hill-Sachs lesion in a patient following a single anterior dislocation. Early reports of this lesion were based on indirect (radiographic) evidence. Our arthroscopic findings indicate that the incidence of this lesion after one anterior dislocation is higher than previously thought.

[Markers of HIV infection in prostitutes: analysis of preventive and risk factors]

We studied 501 prostitutes from the northern and eastern areas of Santiago in november and december, 1987. HIV infection was studied by the HIV antibody and also by HIV antigen. At that time no positive reactors were found. Prostitutes from the northern area were older, of a lower socioeconomic background and less promiscuous, in comparison to prostitutes of the eastern area. However, other disorders of sexual transmission were found in 41% of prostitutes of the northern area and in only 28% of those from the eastern area. This difference may be attributed to the more frequent use of preservative in the latter group.

Adrenal adenocarcinomas: diagnosis and management

Thirty-two patients with adrenal adenocarcinoma are reviewed. Eleven of them had symptoms suggestive of a hormonally functional tumor. The median survival in 17 patients who had the primary tumor removed was 13.5 months from the time of surgery, with one patient surviving disease-free 19 years later. The median survival of 11 patients who did not have surgery owing to delays in diagnosis was 7.5 months from the onset of symptoms. Of six patients given O,P'DDD, two patients had objective regression, one partial, one complete. Early diagnosis may improve survival and curability of this malignant tumor.