Vitreoretinal lymphoma presenting as frosted branch angiitis in a patient with diffuse large B-cell lymphoma.

Purpose: To describe the evaluation, diagnosis, and treatment of vitreoretinal lymphoma presenting as frosted branch angiitis in a patient with diffuse large B-cell lymphoma (DLBCL). Observations: A 57-year-old woman with a history of non-Hodgkin lymphoma and recent DLBCL relapse presented with frosted branch angiitis that raised suspicion for an infectious retinitis but was found to be vitreoretinal lymphoma. Conclusions and Importance: This case primarily highlights the importance of considering vitreoretinal lymphoma on the differential diagnosis of etiologies of frosted branch angiitis. Despite suspicion for vitreoretinal lymphoma, it is also important to treat empirically for infectious etiologies of retinitis in cases of frosted branch angiitis. In this case where the diagnosis was ultimately vitreoretinal lymphoma, weekly alternating intravitreal injections of methotrexate and rituximab led to improvement in visual acuity and retinal infiltration.

Electrical Impedance Tomography for monitoring cardiac radiofrequency ablation: a scoping review of an emerging technology.

Arrhythmias are common cardiac diseases which can be treated effectively by the cardiac radiofrequency ablation (CRFA). However, information regarding the lesion growth within the myocardium is critical to the procedure's safety and efficacy but still unavailable in the current catheterisation lab (CathLab). Over the last 20 years, many efforts have been made in order to track the lesion size during the procedure. Unfortunately, all the approaches have their own limitations preventing them from the clinical translation and hence making the lesion size monitoring during a CRFA still an open issue. Electrical Impedance Tomography (EIT) is an impedance imaging modality that might be able to image the thermal-related impedance changes from which the lesion size can be measured. With the availability of the patient's CT scans, for a detailed model, and the catheter-based electrodes for the internal electrodes, EIT accuracy and sensitivity to the ablated sites can be significantly improved and is worth being explored for this application. Though EIT is still new to CRFA with no in-vivo experiments being done according to our up-to-date searching, many related EIT studies and its extensive research in Hyperthermia and other ablations can reveal many hints for a possibility of the CRFA-EIT application. In this paper, we present a review on multiple aspects of EIT in CRFA. First, the expected CRFA-EIT signal range and frequency are discussed based on various measured impedance results obtained from lesions in the past. Second, the possible noise sources that can happen in a clinical CRFA procedure, along with their signal range and frequency compared to the CRFA-EIT signal, and, third, the available current solutions to separate such noises from the CRFA-EIT signal. Finally, we review the progress of EIT in thermal applications over the last two decades in order to identify the developments that EIT can take advantage of and the current drawbacks that need to be solved for a potential CRFA-EIT application.

Implementing a School Vision Screening Program in Botswana Using Smartphone Technology.

Purpose: Child eye health is a significant public health issue in low- and middle-income countries, such as Botswana, and the need for eye care requires a well-integrated and innovative approach. Traditional vision screening tools are costly, difficult to transport, and reliant on highly trained eye care professionals. Novel smartphone-based vision screening technologies, however, are low cost, portable, and easily operated by trained novice users. Peek Vision is a mobile health (m-Health) organization that creates smartphone applications that screen for visual acuity, generate referrals to eye care professionals, and send phone notifications to those being screened. Methodology: In 2016, the government of Botswana partnered with local and international stakeholders to implement Peek vision screening in a subset of schoolchildren. From June to December of 2016, teachers, health assistants, nurses, and other volunteers in 49 schools in the Goodhope Subdistrict utilized Peek applications to screen schoolchildren, using acuity <6/12 in the better eye as a threshold for visual impairment. Results: Among 12,877 children screened, the application identified 16% (2,065/12,877) as screening positive for visual impairment, and these students were referred for optometric care. Ultimately, 96% (1,985/2,065) attended optometry triage camps, during which 42% (835/1,985) were provided with spectacles, 5% (94/1,985) received ophthalmic medications, and 3% (63/1,985) were referred for ophthalmic care. These findings underscore the need for comprehensive vision screening in schoolchildren in Botswana. Furthermore, the successful implementation of Peek smartphone applications illustrates the potential of m-Health technology for enacting comprehensive vision screening programs at a national level in Botswana and other similar countries.

Nuclear envelope deformation controls cell cycle progression in response to mechanical force.

The shape of the cell nucleus can vary considerably during developmental and pathological processes; however, the impact of nuclear morphology on cell behavior is not known. Here, we observed that the nuclear envelope flattens as cells transit from G1 to S phase and inhibition of myosin II prevents nuclear flattening and impedes progression to S phase. Strikingly, we show that applying compressive force on the nucleus in the absence of myosin II-mediated tension is sufficient to restore G1 to S transition. Using a combination of tools to manipulate nuclear morphology, we observed that nuclear flattening activates a subset of transcription factors, including TEAD and AP1, leading to transcriptional induction of target genes that promote G1 to S transition. In addition, we found that nuclear flattening mediates TEAD and AP1 activation in response to ROCK-generated contractility or cell spreading. Our results reveal that the nuclear envelope can operate as a mechanical sensor whose deformation controls cell growth in response to tension.

On the spatiotemporal regulation of cell tensional state.

Since the emergence of mechanobiology, mechanical signals have been shown to influence almost every process in biology. Cells transduce mechanical signals into biochemical signaling pathways, adjust their behavior and/or phenotype before transmitting these signals to neighboring cells. Mechanical signals thus appear as information, which can be "written" by cells in the surrounding extracellular matrix, "transmitted" through it and "read" by other cells. This brief review summarizes our current understanding of the mechanisms regulating the tensional state of cells and tissues subjected to mechanical perturbations, prior to examining existing or potential experimental approaches to study these mechanisms.

Enucleated cells reveal differential roles of the nucleus in cell migration, polarity, and mechanotransduction.

The nucleus has long been postulated to play a critical physical role during cell polarization and migration, but that role has not been defined or rigorously tested. Here, we enucleated cells to test the physical necessity of the nucleus during cell polarization and directed migration. Using enucleated mammalian cells (cytoplasts), we found that polarity establishment and cell migration in one dimension (1D) and two dimensions (2D) occur without the nucleus. Cytoplasts directionally migrate toward soluble (chemotaxis) and surface-bound (haptotaxis) extracellular cues and migrate collectively in scratch-wound assays. Consistent with previous studies, migration in 3D environments was dependent on the nucleus. In part, this likely reflects the decreased force exerted by cytoplasts on mechanically compliant substrates. This response is mimicked both in cells with nucleocytoskeletal defects and upon inhibition of actomyosin-based contractility. Together, our observations reveal that the nucleus is dispensable for polarization and migration in 1D and 2D but critical for proper cell mechanical responses.