Improving the electronic nexus between generalists and specialists: A public health imperative?

Recent changes in healthcare delivery and payment policy have precipitated interest among healthcare providers across the U.S. seeking innovative strategies to achieve higher quality, lower cost care through improved resource-utilization. One dimension of healthcare delivery with distinctive potential for improvement is care coordination between primary care and specialist providers. Optimizing the nexus between PCPs and specialists through innovations including eConsultation platforms portends reductions in unnecessary referrals and testing, and may help align incentives to promote high-value care. Opportunities and challenges surrounding effective and versatile operationalization of such technologies are assessed, focusing on specific public health needs of access and utilization.

A Comparison of Alternatives for Automated Decision Support in a Multi-Task Environment

Complex, multi-task work environments that require humans to “juggle” many simultaneous tasks are becoming more widespread. How can automated capabilities best support the operator in these environments? We grouped the cognitive workload associated with multi-task management into two broad areas: 1) creating, maintaining, and updating an awareness of the status of all of the active tasks, and 2) choosing actions from among these active tasks based on overall goals. We then developed automated decision support for each of these aspects of workload and assessed which type of support was more effective in improving performance. Our findings indicate that, in a simulated air traffic control environment, the effort associated with creating and maintaining situation awareness was overwhelmingly responsible for the operator's workload. The results suggest that effective decision support in this environment should focus on helping the operator maintain awareness of the changing status of the active tasks, not on setting priorities or choosing among alternative tasks.

A Systematic Approach to Identify Candidate Transcription Factors that Control Cell Identity

Hundreds of transcription factors (TFs) are expressed in each cell type, but cell identity can be induced through the activity of just a small number of core TFs. Systematic identification of these core TFs for a wide variety of cell types is currently lacking and would establish a foundation for understanding the transcriptional control of cell identity in development, disease, and cell-based therapy. Here, we describe a computational approach that generates an atlas of candidate core TFs for a broad spectrum of human cells. The potential impact of the atlas was demonstrated via cellular reprogramming efforts where candidate core TFs proved capable of converting human fibroblasts to retinal pigment epithelial-like cells. These results suggest that candidate core TFs from the atlas will prove a useful starting point for studying transcriptional control of cell identity and reprogramming in many human cell types.

•

Core transcription factors (TFs) are predicted for >200 cell types/tissues

•

Predicted TFs for retinal pigment epithelial (RPE) cells can reprogram fibroblasts

•

These reprogrammed RPE-like cells are functionally similar to primary RPE

•

The sets of predicted factors may facilitate studies of control of cell identity

Cautionary optimism: caffeine and Parkinson's disease risk

Most Parkinson’s disease (PD) patients present without known family history and without a diagnosed prodromal phase, underscoring the difficulty of employing primary (neuroprevention) and secondary (neuroprotection) preventions. In cases of monogenic forms, however, potential gene-carrying family members of a proband could engage in neuroprevention, such as exercise or diet modifications, to attenuate the risk of, or delay, disease development. However, a historical lack of recognized disease-modifying interventions has limited clinicians’ ability to recommend reliable preventive measures in caring for at-risk populations. We briefly analyze the first retrospective study to examine caffeine consumption and PD risk in a LRRK2 R1628P cohort.

Decellularized retinal matrix: Natural platforms for human retinal progenitor cell culture

Tissue decellularization strategies have enabled engineering of scaffolds that preserve native extracellular matrix (ECM) structure and composition. In this study, we developed decellularized retina (decell-retina) thin films. We hypothesized that these films, mimicking the retina niche, would promote human retinal progenitor cell (hRPC) attachment, proliferation and differentiation. Retinas isolated from bovine eyes were decellularized using 1% w/v sodium dodecyl sulfate (SDS) and pepsin digested. The resulting decell-retina was biochemically assayed for composition and cast dried to develop thin films. Attachment, viability, morphology, proliferation and gene expression of hRPC cultured on the films were studied in vitro. Biochemical analyses of decell-retina compared to native retina indicated the bulk of DNA (94%) was removed, while the majority of sulfated GAGs (55%), collagen (83%), hyaluronic acid (87%), and key growth factors were retained. The decell-retina films supported hRPC attachment and growth, with cell number increasing 1.5-fold over a week. RT-PCR analysis revealed hRPC expression of rhodopsin, rod outer membrane, neural retina-specific leucine zipper neural and cone-rod homeobox gene on decell-retina films, indicating photoreceptor development. In conclusion, novel decell-retina films show promise as potential substrates for culture and/or transplantation of retinal progenitor cells to treat retinal degenerative disorders.

STATEMENT OF SIGNIFICANCE

In this study, we report the development of a novel biomaterial, based on decellularized retina (decell-retina) that mimics the retina niche and promotes human retinal progenitor cell (hRPC) attachment, proliferation and differentiation. We estimated, for the first time, the amounts of collagen I, GAGs and HA present in native retina, as well as the decell-retina. We demonstrated that retinas can be decellularized using ionic detergents and can be processed into mechanically stable thin films, which can act as substrates for culturing hRPCs. Rhodopsin, ROM1, NRL and CRX gene expression on the decell-retina films indicated photoreceptor development from RPCs. These results support the potential of decell-retina as a cell delivery platform to treat and manage retinal degenerative disease like AMD.

Bioenhancements and the telos of medicine

Staggering advances in biotechnology within the past decade have given rise to pharmacological, surgical and prosthetic techniques capable of enhancing human functioning rather than merely treating or preventing disease. Bioenhancement technologies range from nootropics capable of enhancing cognitive abilities to distraction osteogenesis, a surgical technique capable of increasing height through limb lengthening. This paper examines whether the use of bioenhancements falls inside or outside the proper boundaries of healthcare, and if so, whether clinicians have professional responsibilities to administer bioenhancements to patients. After explicating two theoretical approaches to the concept of health, one objectivist and the other constructivist, I contend that clinicians' corresponding professional responsibilities hinge on which philosophical account of health is endorsed, and illustrate how the lack of analytic clarity with respect to this concept can lead to defective positions on the place of bioenhancements in healthcare. With this conceptual framework in place, an account of health as a cluster concept that incorporates both constructivist and objectivist components is developed and defended.

Obstruction of an ileal urinary conduit in an incarcerated right inguinal hernia

We present the case of a 72-year-old man with a history of anuria from his ileal conduit 15 months following its formation. That conduit had become incarcerated in a right-sided ingunial hernia. The patient presented with anuria and an acute kidney injury. A clincal diagnosis of an incarcerated hernia was made, and he was taken to theatre for reduction and repair of the hernia. On removal of the conduit from the hernial sac, it began to drain immediately. He made a full recovery, with normalisation of his renal function.

Enhanced differentiation and delivery of mouse retinal progenitor cells using a micropatterned biodegradable thin-film polycaprolactone scaffold

The deterioration of retinal tissue in advanced stages of retinitis pigmentosa and age-related macular degeneration and the lack of signaling cues for laminar regeneration are significant challenges highlighting the need for a tissue engineering approach to retinal repair. In this study, we fabricated a biodegradable thin-film polycaprolactone (PCL) scaffold with varying surface topographies using microfabrication techniques. Mouse retinal progenitor cells (mRPCs) cultured on PCL scaffolds exhibited enhanced potential to differentiate toward a photoreceptor fate in comparison to mRPCs cultured on control substrates, suggesting that PCL scaffolds are promising as substrates to guide differentiation of mRPCs toward a photoreceptor fate in vitro before transplantation. When cocultured with the retinal explants of rhodopsin null mice, mRPC/PCL constructs showed increased mRPC integration rates compared to directly applied dissociated mRPCs. Moreover, these mRPC/PCL constructs could be delivered into the subretinal space of rhodopsin null mice with minimal disturbance of the host retina. Whether cocultured with retinal explants or transplanted into the subretinal space, newly integrated mRPCs localized to the outer nuclear layer and expressed appropriate markers of photoreceptor fate. Thus, the PCL scaffold provides a platform to guide differentiation and organized delivery of mRPCs as a practical strategy to repair damaged retina.

Narrative Symposium: Patient and Research Participant experiences with Genetic Testing

Twelve personal narratives address the challenges, benefits, and pitfalls of genetic testing. Three commentary articles explore these stories and suggest lessons that can be learned from them. The commentators come from backgrounds that include bioethics, public health, psychology, and philosophy.

Functional and morphological analysis of the subretinal injection of human retinal progenitor cells under Cyclosporin A treatment

PURPOSE

The purpose of this study is to evaluate the functional and morphological changes in subretinal xenografts of human retinal progenitor cells (hRPCs) in B6 mice treated with Cyclosporin A (CsA; 210 mg/l in drinking water).

METHODS

The hRPCs from human fetal eyes were isolated and expanded for transplantation. These cells, with green fluorescent protein (GFP) at 11 passages, were transplanted into the subretinal space in B6 mice. A combination of invasive and noninvasive approaches was used to analyze the structural and functional consequences of the subretinal injection of the hRPCs. The process of change was monitored using spectral domain optical coherence tomography (SDOCT), histology, and electroretinography (ERG) at 3 days, 1 week, and 3 weeks after transplantation. Cell counts were used to evaluate the survival rate with a confocal microscope. ERGs were performed to evaluate the physiologic changes, and the structural changes were evaluated using SDOCT and histological examination.

RESULTS

The results of the histological examination showed that the hRPCs gained a better survival rate in the mice treated with CsA. The SDOCT showed that the bleb size of the retinal detachment was significantly decreased, and the retinal reattachment was nearly complete by 3 weeks. The ERG response amplitudes in the CsA group were less decreased after the injection, when compared with the control group, in the dark-adapted and light-adapted conditions. However, the cone-mediated function in both groups was less affected by the transplantation after 3 weeks than the rod-mediated function.

CONCLUSIONS

Although significant functional and structural recovery was observed after the subretinal injection of the hRPCs, the effectiveness of CsA in xenotransplantation may be a novel and potential approach for increasing retinal progenitor cell survival.

Approaches to cell delivery: substrates and scaffolds for cell therapy

Retinal degeneration, associated with loss of photoreceptors, is the primary cause of permanent vision impairment, impacting millions of people worldwide. Age-related macular degeneration and retinitis pigmentosa are two common retinal diseases resulting in photoreceptor loss and vision impairment or blindness. Presently, available treatments can only delay the progress of retinal degeneration, and there are no treatments that can restore permanent vision loss. Research is underway to develop methods of regenerating the impaired retina by delivering photoreceptor precursor cells and retinal pigment epithelium to the subretinal space. Challenges to cell transplantation include limited survival upon implantation and the formation of abnormal cell architectures in vivo. Retinal tissue engineering shows immense promise and potential in treatment of retinal degeneration by employing scaffold-based delivery systems of retinal progenitor cells to the subretinal space. Scaffold delivery strategy has been shown to enhance the cell survival and direct cell differentiation in a variety of retinal degenerative models. In this chapter, we summarize the research findings on different scaffold- or substrate-based transplantation techniques used to deliver retinal progenitor/photoreceptor precursors and retinal pigment epithelial cells to the subretinal space.

CCL2-dependent macrophage recruitment is critical for mineralocorticoid receptor-mediated cardiac fibrosis, inflammation, and blood pressure responses in male mice

Recent studies show that mice with selective deletion of the mineralocorticoid receptor (MR) in macrophages are protected from mineralocorticoid-induced cardiac fibrosis and hypertension without altering cardiac macrophage accumulation. However, it is unclear whether preventing macrophages from entering cardiac tissue would provide similar or additional protection in this disease setting. Therefore, we examined mineralocorticoid-induced cardiovascular disease in mice lacking the CCL2 gene (encoding monocyte chemoattractant protein-1), which have a markedly reduced capacity to recruit proinflammatory tissue macrophages. Male wild-type (WT) and CCL2-null mice were treated for 8 days or 8 weeks with either vehicle (control, CON) or deoxycorticosterone (DOC). At both time points, there was a significant reduction in DOC-induced macrophage recruitment (50% at 8 d and 75% at 8 wk) in the heart with a corresponding suppression of cardiac inflammatory markers in the CCL2-null mice. CCL2-null mice given DOC/salt also displayed 35% less cardiac fibrosis at 8 weeks vs WT DOC. Absence of recruited macrophages in CCL2-null mice promotes greater collagen breakdown by matrix metalloproteinase-9 in the heart and also leads to significantly reduced cardiac fibroblast and myofibroblast numbers. Systolic blood pressure (BP) after DOC/salt was significantly lower in CCL2-null than for WT mice. In the aorta at 8 weeks, MR-responsive gene expression remained intact. However, macrophage-mediated proinflammatory gene expression was reduced in the CCL2-null mice and may account for differential regulation of BP. Our data thus demonstrate an important role for CCL2-dependent macrophage recruitment in MR-dependent cardiac inflammation and remodeling and in the regulation of systolic BP.

Undocumented injustice? Medical repatriation and the ends of health care

The authors review the history and motivations behind medical repatriation, the transfer of undocumented patients in need of subacute care to their country of origin. They argue that involuntary medical repatriation violates the ethical duties of health care providers.

Low-oxygen culture conditions extend the multipotent properties of human retinal progenitor cells

PURPOSE

Development of an effective cell-based therapy is highly dependent upon having a reproducible cell source suitable for transplantation. One potential source, isolated from the developing fetal neural retina, is the human retinal progenitor cell (hRPC). One limiting factor for the use of hRPCs is their in vitro expansion limit. As such, the aim of this study was to determine whether culturing hRPCs under 3% O2 would support their proliferative capacity while maintaining multipotency.

METHODS

To determine the effect of low oxygen on the ability of hRPCs to self-renew, rates of proliferation and apoptosis, telomerase activity, and expression of proliferative, stemness, and differentiation markers were assessed for hRPCs cultured in 3% and 20% oxygen conditions.

RESULTS

Culture under 3% oxygen increases the proliferation rate and shifts the proliferation limit of hRPCs to greater 40 divisions. This increased capacity for proliferation is correlated with an upregulation of Ki67, CyclinD1, and telomerase activity and a decrease in p53 expression and apoptosis. Increased expression of cMyc, Klf4, Oct4, and Sox2 in 3% O₂ is correlated with stabilization of both HIF1α and HIF2α. The eye field development markers Pax6, Sox2, and Otx2 are present in hRPCs up to passage 16 in 3% O₂ . Following in vitro differentiation hRPCs expanded in the 3% O₂ were able to generate specialized retinal cells, including rods and cones.

CONCLUSIONS

Low-oxygen culture conditions act to maintain both multipotency and self-renewal properties of hRPCs in vitro. The extended expansion limits permit the development of a clinical-grade reagent for transplantation.

Use of a synthetic xeno-free culture substrate for induced pluripotent stem cell induction and retinal differentiation

The purpose of this study was to determine whether a proprietary xeno-free synthetic culture surface could be used to aid in the production and subsequent retinal-specific differentiation of clinical-grade induced pluripotent stem cells (iPSCs). iPSCs were generated using adult somatic cells via infection with either a single cre-excisable lentiviral vector or four separate nonintegrating Sendai viruses driving expression of the transcription factors OCT4, SOX2, KLF4, and c-MYC. Retinal precursor cells were derived via targeted differentiation of iPSCs with exogenous delivery of dkk-1, noggin, insulin-like growth factor-1, basic fibroblast growth factor, acidic fibroblast growth factor, and DAPT. Phase contrast microscopy, immunocytochemistry, hematoxylin and eosin staining, and reverse transcription-polymerase chain reaction were used to determine reprogramming efficiency, pluripotency, and fate of undifferentiated and differentiated iPSCs. Following viral transduction, cells underwent prototypical morphological changes resulting in the formation of iPSC colonies large enough for manual isolation/passage at 3-4 weeks postinfection. Both normal and disease-specific iPSCs expressed markers of pluripotency and, following transplantation into immune-compromised mice, formed teratomas containing tissue comprising all three germ layers. When subjected to our established retinal differentiation protocol, a significant proportion of the xeno-free substrate-derived cells expressed retinal cell markers, the number of which did not significantly differ from that derived on traditional extracellular matrix-coated dishes. Synthetic cell culture substrates provide a useful surface for the xeno-free production, culture, and differentiation of adult somatic cell-derived iPSCs. These findings demonstrate the potential utility of these surfaces for the production of clinical-grade retinal neurons for transplantation and induction of retinal regeneration.

Preservation of biological activity of glial cell line-derived neurotrophic factor (GDNF) after microencapsulation and sterilization by gamma irradiation

A main issue in controlled delivery of biotechnological products from injectable biodegradable microspheres is to preserve their integrity and functional activity after the microencapsulation process and final sterilization. The present experimental work tested different technological approaches to maintain the biological activity of an encapsulated biotechnological product within PLGA [poly (lactic-co-glycolic acid)] microspheres (MS) after their sterilization by gamma irradiation. GDNF (glial cell line-derived neurotrophic factor), useful in the treatment of several neurodegenerative diseases, was chosen as a labile model protein. In the particular case of optic nerve degeneration, GDNF has been demonstrated to improve the damaged retinal ganglion cells (RGC) survival. GDNF was encapsulated in its molecular state by the water-in-oil-in-water (W/O/W) technique or as solid according to the solid-in-oil-in-water (S/O/W) method. Based on the S/O/W technique, GDNF was included in the PLGA microspheres alone (S/O/W 1) or in combination with an antioxidant (vitamin E, Vit E) (S/O/W 2). Microspheres were sterilized by gamma-irradiation (dose of 25 kGy) at room and low (-78 °C) temperatures. Functional activity of GDNF released from the different microspheres was evaluated both before and after sterilization in their potential target cells (retinal cells). Although none of the systems proposed achieved with the goal of totally retain the structural stability of the GDNF-dimer, the protein released from the S/O/W 2 microspheres was clearly the most biologically active, showing significantly less retinal cell death than that released from either W/O/W or S/O/W 1 particles, even in low amounts of the neurotrophic factor. According to the results presented in this work, the biological activity of biotechnological products after microencapsulation and sterilization can be further preserved by the inclusion of the active molecule in its solid state in combination with antioxidants and using low temperature (-78 °C) during gamma irradiation exposure.

Monitoring morphological changes in the retina of rhodopsin-/- mice with spectral domain optical coherence tomography

PURPOSE

The rhodopsin(-/-) C57Bl/6 (rho(-/-)) mouse is a very important model for understanding retinal degenerative diseases. In this study, spectral domain optical coherence tomography (SD-OCT) was used to monitor the dynamic morphological changes in retina of rho(-/-) mice.

METHODS

Rho(-/-) mice and wild type C57Bl/6 (B6) mice at the age of 3, 6, 9, and 12 weeks were investigated using SD-OCT to obtain cross-sectional images of the retina. The outer nuclear layer (ONL) thickness was measured. Histological sections were used to compare to the OCT data. Electroretinograms (ERG) were performed to evaluate the physiological change for establishing the relationship between retinal morphology and its functional changes.

RESULTS

There was no apparent morphological or functional change in B6 mice at any time point. The SD-OCT measurement showed that the ONL thickness in rho(-/-) mice was significantly decreased from 40.6 μm to 6.0 μm from week 3 to week 12 postnatal. Histological examinations identified a similar trend, although the average thickness of ONL from histological sections at these time points was slightly larger (ranging from 55.4 μm to 14.9 μm). The ERG in rho(-/-) mice indicated functional changes that were in concordant with morphological changes; a significant linear positive association was identified between the amplitude of b-wave and the ONL thickness.

CONCLUSIONS

Our findings confirmed that the functional changes in retina were concordant with morphological changes measured by SD-OCT in vivo, which indicates that SD-OCT can be used as a reliable noninvasive method to monitor the degenerative progression in retinal disease models.

Transplantation of adult mouse iPS cell-derived photoreceptor precursors restores retinal structure and function in degenerative mice

This study was designed to determine whether adult mouse induced pluripotent stem cells (iPSCs), could be used to produce retinal precursors and subsequently photoreceptor cells for retinal transplantation to restore retinal function in degenerative hosts. iPSCs were generated using adult dsRed mouse dermal fibroblasts via retroviral induction of the transcription factors Oct4, Sox2, KLF4 and c-Myc. As with normal mouse ES cells, adult dsRed iPSCs expressed the pluripotency genes SSEA1, Oct4, Sox2, KLF4, c-Myc and Nanog. Following transplantation into the eye of immune-compromised retinal degenerative mice these cells proceeded to form teratomas containing tissue comprising all three germ layers. At 33 days post-differentiation a large proportion of the cells expressed the retinal progenitor cell marker Pax6 and went on to express the photoreceptor markers, CRX, recoverin, and rhodopsin. When tested using calcium imaging these cells were shown to exhibit characteristics of normal retinal physiology, responding to delivery of neurotransmitters. Following subretinal transplantation into degenerative hosts differentiated iPSCs took up residence in the retinal outer nuclear layer and gave rise to increased electro retinal function as determined by ERG and functional anatomy. As such, adult fibroblast-derived iPSCs provide a viable source for the production of retinal precursors to be used for transplantation and treatment of retinal degenerative disease.