Tetherin inhibits HIV-1 release by directly tethering virions to cells.

Tetherin is an interferon-induced protein whose expression blocks the release of HIV-1 and other enveloped viral particles. The underlying mechanism by which tetherin functions and whether it directly or indirectly causes virion retention are unknown. Here, we elucidate the mechanism by which tetherin exerts its antiviral activity. We demonstrate, through mutational analyses and domain replacement experiments, that tetherin configuration rather than primary sequence is critical for antiviral activity. These findings allowed the design of a completely artificial protein, lacking sequence homology with native tetherin, that nevertheless mimicked its antiviral activity. We further show that tetherin is incorporated into HIV-1 particles as a parallel homodimer using either of its two membrane anchors. These results indicate that tetherin functions autonomously and directly and that infiltration of virion envelopes by one or both of tetherin's membrane anchors is necessary, and likely sufficient, to tether enveloped virus particles that bud through the plasma membrane.

Frequency and phenotypic spectrum of spinocerebellar ataxia 27B and other genetic ataxias in a Spanish cohort of late-onset cerebellar ataxia.

BACKGROUND AND PURPOSE: Dominantly inherited GAA repeat expansions in the fibroblast growth factor 14 (FGF14) gene have recently been shown to cause spinocerebellar ataxia 27B (SCA27B). We aimed to study the frequency and phenotype of SCA27B in a cohort of patients with unsolved late-onset cerebellar ataxia (LOCA). We also assessed the frequency of SCA27B relative to other genetically defined LOCAs. METHODS: We recruited a consecutive series of 107 patients with LOCA, of whom 64 remained genetically undiagnosed. We screened these 64 patients for the FGF14 GAA repeat expansion. We next analysed the frequency of SCA27B relative to other genetically defined forms of LOCA in the cohort of 107 patients. RESULTS: Eighteen of 64 patients (28%) carried an FGF14 (GAA)≥250 expansion. The median (range) age at onset was 62.5 (39-72) years. The most common clinical features included gait ataxia (100%) and mild cerebellar dysarthria (67%). In addition, episodic symptoms and downbeat nystagmus were present in 39% (7/18) and 37% (6/16) of patients, respectively. SCA27B was the most common cause of LOCA in our cohort (17%, 18/107). Among patients with genetically defined LOCA, SCA27B was the main cause of pure ataxia, RFC1-related disease of ataxia with neuropathy, and SPG7 of ataxia with spasticity. CONCLUSION: We showed that SCA27B is the most common cause of LOCA in our cohort. Our results support the use of FGF14 GAA repeat expansion screening as a first-tier genetic test in patients with LOCA.

Microlearning through TikTok in Higher Education. An evaluation of uses and potentials.

While social media is evolving rapidly, understanding its underlying and persistent features with the potential to support high-quality learning would provide opportunities to enhance competence acquisition and collaborative work in higher education. Moreover, the adoption of tools that students already use in their everyday lives facilitates the integration of new forms of learning. In this context, we have developed an initiative to disseminate content through TikTok in three modules of the Bachelor's Degree in Nursing course, with the aim of promoting quality learning through these microlearning environments. To this end, we have implemented these learning environments and evaluated the users' perceptions, as well as their level of acceptance of the technology according to the Technology Acceptance Model. Overall, our results show high levels of satisfaction with regard to engagement and the content generated, as well as in terms of the acceptance of the technology. Our results do not show gender-specific variations, but we did detect slight variations depending on the subject in which the microlearning tool was deployed. Although for the most part these variations do not change the participants' assessment of their experience, it will be necessary in the future to determine the underlying reasons for these variations. In addition, our results suggest that it is possible to design a content creation system to promote quality learning through microlearning that can be transferred to other subjects, at least in the Bachelor's Degree in Nursing. Supplementary Information: The online version contains supplementary material available at 10.1007/s10639-023-11904-4.

Current Trends in Microfluidics and Biosensors for Cancer Research Applications.

Despite the significant amount of resources invested, cancer remains a considerable burden in our modern society and a leading cause of death. There is still a lack of knowledge about the mechanistic determinants of the disease, the mechanism of action of drugs, and the process of tumor relapse. Current methodologies to study all these events fail to provide accurate information, threatening the prognosis of cancer patients. This failure is due to the inadequate procedure in how tumorigenesis is studied and how drug discovery and screening are currently made. Traditionally, they both rely on seeding cells on static flat cultures and on the immunolabelling of cellular structures, which are usually limited in their ability to reproduce the complexity of the native cellular habitat and provide quantitative data. Similarly, more complex animal models are employed for-unsuccessfully-mimicking the human physiology and evaluating the etiology of the disease or the efficacy/toxicity of pharmacological compounds. Despite some breakthroughs and success obtained in understanding the disease and developing novel therapeutic approaches, cancer still kills millions of people worldwide, remaining a global healthcare problem with a high social and economic impact. There is a need for novel integrative methodologies and technologies capable of providing valuable readouts. In this regard, the combination of microfluidics technology with miniaturized biosensors offers unprecedented advantages to accelerate the development of drugs. This integrated technology have the potential to unravel the key pathophysiological processes of cancer progression and metastasis, overcoming the existing gap on in vitro predictive platforms and in vivo model systems. Herein, we discuss how this combination may boost the field of cancer theranostics and drug discovery/screening toward more precise devices with clinical relevance.

From Exosomes to Circulating Tumor Cells: Using Microfluidics to Detect High Predictive Cancer Biomarkers.

Early cancer screening and effective diagnosis is the most effective form to diminish the number of cancer-related deaths. Liquid biopsy constitutes an attractive alternative to tumor biopsy due to its non-invasive nature and sample accessibility, which permits effective screening and patient monitoring. Within the plethora of biomarkers present in circulation, liquid biopsy has mainly been performed by analyzing circulating tumor cells, and more recently, extracellular vesicles. Tracking these biological particles could provide valuable insights into cancer origin, progression, treatment efficacy, and patient prognosis. Microfluidic devices have emerged as viable solutions for point-of-care cancer screening and monitoring due to their user-friendly operation, low operation costs, and capability of processing, quantifying, and analyzing these bioparticles in a single device. However, the size difference between cells and exosomes (micrometer vs nanometer) requires an adaptation of microfluidic isolation approaches, particularly in label-free methodologies governed by particle and fluid mechanics. This chapter will explore the theory behind particle isolation and sorting in different microfluidic techniques necessary to guide researchers into the design and development of such devices.

Emerging Microfluidic and Biosensor Technologies for Improved Cancer Theranostics.

Microfluidics and biosensors have already demonstrated their potential in cancer research. Typical applications of microfluidic devices include the realistic modeling of the tumor microenvironment for mechanistic investigations or the real-time monitoring/screening of drug efficacy. Similarly, point-of-care biosensing platforms are instrumental for the early detection of predictive biomarkers and their accurate quantification. The combination of both technologies offers unprecedented advantages for the management of the disease, with an enormous potential to contribute to improving patient prognosis. Despite their high performance, these methodologies are still encountering obstacles for being adopted by the healthcare market, such as a lack of standardization, reproducibility, or high technical complexity. Therefore, the cancer research community is demanding better tools capable of boosting the efficiency of cancer diagnosis and therapy. During the last years, innovative microfluidic and biosensing technologies, both individually and combined, have emerged to improve cancer theranostics. In this chapter, we discuss how these emerging-and in some cases unconventional-microfluidics and biosensor technologies, tools, and concepts can enhance the predictive power of point-of-care devices and the development of more efficient cancer therapies.

Frequency, Predictors, Etiology, and Outcomes for Deep Intracerebral Hemorrhage without Hypertension.

OBJECTIVES: Some patients with deep intracerebral hemorrhage (ICH) have a transient hypertensive response and they may be erroneously classified as secondary to hypertension. We investigated frequency, risk factors, and outcomes for patients with deep ICH without hypertension. MATERIALS AND METHODS: We consecutively recruited patients with spontaneous ICH attending two Spanish stroke centers (January 2015-June 2019). Excluded were patients with lobar/infratentorial ICH and patients who died during hospitalization. We defined deep ICH without hypertension when the bleeding was in a deep structure, no requirement for antihypertensive agents during follow-up and no evident chronic hypertension markers evaluated by transthoracic echocardiography, 24 h ambulatory blood pressure monitoring and/or electrocardiography. We compared clinical, radiological, and 3-month functional outcome data for deep-ICH patients with hypertension versus those without hypertension. RESULTS: Of 759 patients with ICH, 219 (mean age 69.6 ± 15.4 years, 54.8% men) met the inclusion criteria and 36 (16.4%) did not have hypertension. Of these 36 patients, 19 (52.7%) had a transient hypertensive response. Independent predictors of deep ICH without hypertension were age (adjusted OR:0.94;95%CI:0.91-0.96) and dyslipidemia (adjusted OR:0.27;95% CI:0.08-0.85). One third of deep ICH without hypertension were secondary to vascular malformations. Favorable outcomes (modified Rankin Scale 0-2) were more frequent in patients with deep ICH without hypertension compared to those with hypertension (70.9% vs 33.8%; p < 0.001). CONCLUSION: Of patients with deep ICH, 16.4% were unrelated with hypertension, around half showed hypertensive response, and around a third had vascular malformations. We suggest studying hypertension markers and performing a follow-up brain MRI in those patients with deep ICH without prior hypertension.

Providing Spiritual Care to In-Hospital Patients During COVID-19: A Preliminary European Fact-Finding Study.

Historically, there has be a close relationship between the nursing services and spiritual care provision to patients, arising due to the evolvement of many hospitals and nursing programmes from faith-based institutions and religious order nursing. With increasing secularism, these relationships are less entwined. Nonetheless, as nurses typically encounter patients at critical life events, such as receiving bad news or dying, nurses frequently understand the need and requirement for both spiritual support and religious for patients and families during these times. Yet there are uncertainties, and nurses can feel ill-equipped to deal with patients' spiritual needs. Little education or preparation is provided to these nurses, and they often report a lack of confidence within this area. The development of this confidence and the required competencies is important, especially so with increasingly multicultural societies with diverse spiritual and religious needs. In this manuscript, we discuss initial field work carried out in preparation for the development of an Erasmus Plus educational intervention, entitled from Cure to Care Digital Education and Spiritual Assistance in Healthcare. Referring specifically to post-COVID spirituality needs, this development will support nurses to respond to patients' spiritual needs in the hospital setting, using digital means. This preliminary study revealed that while nurses are actively supporting patients' spiritual needs, their education and training are limited, non-standardised and heterogeneous. Additionally, most spiritual support occurs within the context of a Judeo-Christian framework that may not be suitable for diverse faith and non-faith populations. Educational preparation for nurses to provide spiritual care is therefore urgently required.

Memories of hunger, continuities, and food choices: An ethnography of the elderly in extremadura (Spain).

Food choices are a complex subject of study. This study reviews existing literature on the topic, while also offering new perspectives. It introduces empirical materials that suggest the existence of continuities between childhood memories of food insecurity and current nutritional choices and practices among older adults. This is a qualitative study, based on grounded theory, which explores memories of hunger in the aftermath of the Spanish Civil War through ethnographic fieldwork conducted in 12 rural localities in Extremadura (Spain) - analysing current food practices and ideologies among surviving post-war children and tracing continuities between the past and the present. It provides results in the field of food continuities and shows how experiences and memories of hunger have an impact on food choices many decades later Data analysis and interpretation revealed three main categories: food memories of the so-called "years of hunger"; present-day food practices; and continuities between past and present. The inductive-deductive analysis revealed enduring memories that shaped present-day attitudes towards food - i.e. maximisation of ingredients and "zero-waste" practices; conspicuous consumption at particular times of the year; the central role of bread; and even certain food taboos. More than seventy years later, memories of deprivation and hunger are still pervasive and permeate present-day dietary practices and choices.

Silicon Based Coplanar Capacitive Device for Liquid Sensor Applications.

The development of silicon-based sensor devices has enabled the possibility to pursue novel integrated smart sensor technologies. Under this scenario, capacitive sensor devices are one viable option for implementing different kinds of applications. In this paper, an interdigitated coplanar capacitive device fabricated over a silicon substrate is presented and its potential use as liquid sensor is demonstrated. Additionally, a detailed capacitance model, which includes the parasitic capacitances introduced by the silicon substrate, was developed. The capacitance model has been theoretically validated through finite-element simulations as well as experimentally by comparison with fabricated devices. A polydimethylsiloxane mold has been fabricated and bonded to the sensor device with the aim of defining a cavity to collect the liquid sample into the device's active region. The active capacitance component correlates to the electric field coupling between adjacent metal lines. Therefore, any change to the dielectric constant of the medium above the coplanar metal lines will produce a change to the device capacitance. Finally, the main guidelines for device performance improvement are depicted.

Description of Two Families with New Mutations in Familial Cerebral Cavernous Malformations Genes.

Cerebral cavernous malformations (CCMs) are dilated aberrant leaky capillaries located in the Central Nervous System. Familial CCM is an autosomal dominant inherited disorder related to mutations in KRIT1, Malcavernin or PDCD10. We show two unrelated families presenting familial CCM due to two new mutations in KRIT1 and PDCD10, producing truncated proteins. Clinical phenotype was highly variable among patients from asymptomatic individuals to diplopia, seizures or severe intracranial hemorrhage. PDCD10 patients usually show a more aggressive course and they frequently showed multiple meningiomas. This work provides evidence for the pathogenicity of two new mutations in CCM genes and supports previous findings regarding familial CCM and multiple meningiomas.

Cryptococcal meningoencephalitis presenting as cerebral venous thrombosis.

Cerebral venous thrombosis (CVT) is characterized by its variety of neurological manifestations and difficulty in diagnosis. In subacute cases, the main symptoms are secondary to increased intracranial pressure. This condition is associated with an extensive range of medical disorders, but only 2% are caused by a CNS infection in recent series. We report a 45-year-old patient, with no previous medical history, who developed a syndrome of increased intracranial pressure as the presentation of a cryptococcal meningoencephalitis (CM) complicated with a CVT. The patient was first diagnosed of a CVT, and later on, the VIH infection and the CM diagnosis were made. Despite being treated with anticoagulation, liposomal amphotericin B, and a therapeutic lumbar puncture, the patient continued to deteriorate and suffered a respiratory arrest secondary to the increased intracranial pressure, with subsequent brain death. Cryptococcus is an infrequent cause of CNS infection in developed countries, despite being the most frequent cause of meningits in adults in several countries with high rates of HIV infection. CVT is a very rare complication of CM which can contribute to worsen the increased intracranial pressure and in consequence, its prognosis and outcome. A high level of suspicion is needed for diagnosing CM as the underlying cause of CVT and the subsequent increased intracranial pressure should be managed exhaustively.

Engineering Patient-on-a-Chip Models for Personalized Cancer Medicine.

Traditional in vitro and in vivo models typically used in cancer research have demonstrated a low predictive power for human response. This leads to high attrition rates of new drugs in clinical trials, which threaten cancer patient prognosis. Tremendous efforts have been directed towards the development of a new generation of highly predictable pre-clinical models capable to reproduce in vitro the biological complexity of the human body. Recent advances in nanotechnology and tissue engineering have enabled the development of predictive organs-on-a-chip models of cancer with advanced capabilities. These models can reproduce in vitro the complex three-dimensional physiology and interactions that occur between organs and tissues in vivo, offering multiple advantages when compared to traditional models. Importantly, these models can be tailored to the biological complexity of individual cancer patients resulting into biomimetic and personalized cancer patient-on-a-chip platforms. The individualized models provide a more accurate and physiological environment to predict tumor progression on patients and their response to drugs. In this chapter, we describe the latest advances in the field of cancer patient-on-a-chip, and discuss about their main applications and current challenges. Overall, we anticipate that this new paradigm in cancer in vitro models may open up new avenues in the field of personalized - cancer - medicine, which may allow pharmaceutical companies to develop more efficient drugs, and clinicians to apply patient-specific therapies.

COL4A1 Mutation as a Cause of Familial Recurrent Intracerebral Hemorrhage.

The COL4A1 mutation is a very rare monogenic cause of small vessel disease related to recurrent intracerebral hemorrhage. We report a family in which the index case presented with two intracerebral hemorrhages in the basal ganglia with severe periventricular leukoaraiosis and a cataract and vascular tortuosity in the ophthalmological study. His twin brother also had severe leukoaraiosis and multiple subcortical microhemorrhages as well as a congenital cataract and vascular tortuosity in the retina. The older sister had a porencephalic cyst and involvement of the periventricular white matter and intracerebral hemorrhage. In single-gene testing, all three were found to have the same COL4A1 mutation. Intracerebral subcortical hemorrhages or microhemorrhages and severe subcortical leukoaraiosis in familial cases may be related to COL4 mutations.

Protrusion membrane pearling emerges during 3D cell division.

Cell division is accompanied by dramatic changes in shape that ultimately lead to the physical separation of one cell into two. In 2D microenvironments, cells round up and remain adhered onto the substrate by thin retraction fibers during division. In contrast, in 3D environments, cells divide exhibiting long protrusions that guide the orientation of the division axis. However, the mechanism of cell division in three dimensions still remains poorly understood. Here we report the spontaneous formation of transient quasiperiodic membrane pearling on extended mitotic protrusions during 3D cell division. Protrusion membrane pearling may be initiated by the non-uniform distribution of focal adhesions and consequent stationary instability of the protrusive membrane. Overall, membrane pearling emergence may provide insights into a novel modality of 3D cell division with potential physiological relevance.

Fates of retroviral core components during unrestricted and TRIM5-restricted infection.

TRIM5 proteins can restrict retroviral infection soon after delivery of the viral core into the cytoplasm. However, the molecular mechanisms by which TRIM5α inhibits infection have been elusive, in part due to the difficulty of developing and executing biochemical assays that examine this stage of the retroviral life cycle. Prevailing models suggest that TRIM5α causes premature disassembly of retroviral capsids and/or degradation of capsids by proteasomes, but whether one of these events leads to the other is unclear. Furthermore, how TRIM5α affects the essential components of the viral core, other than capsid, is unknown. To address these questions, we devised a biochemical assay in which the fate of multiple components of retroviral cores during infection can be determined. We utilized cells that can be efficiently infected by VSV-G-pseudotyped retroviruses, and fractionated the cytosolic proteins on linear gradients following synchronized infection. The fates of capsid and integrase proteins, as well as viral genomic RNA and reverse transcription products were then monitored. We found that components of MLV and HIV-1 cores formed a large complex under non-restrictive conditions. In contrast, when MLV infection was restricted by human TRIM5α, the integrase protein and reverse transcription products were lost from infected cells, while capsid and viral RNA were both solubilized. Similarly, when HIV-1 infection was restricted by rhesus TRIM5α or owl monkey TRIMCyp, the integrase protein and reverse transcription products were lost. However, viral RNA was also lost, and high levels of preexisting soluble CA prevented the determination of whether CA was solubilized. Notably, proteasome inhibition blocked all of the aforementioned biochemical consequences of TRIM5α-mediated restriction but had no effect on its antiviral potency. Together, our results show how TRIM5α affects various retroviral core components and indicate that proteasomes are required for TRIM5α-induced core disruption but not for TRIM5α-induced restriction.

Protrusion fluctuations direct cell motion.

Many physiological phenomena involve directional cell migration. It is usually attributed to chemical gradients in vivo. Recently, other cues have been shown to guide cells in vitro, including stiffness/adhesion gradients or micropatterned adhesive motifs. However, the cellular mechanism leading to these biased migrations remains unknown, and, often, even the direction of motion is unpredictable. In this study, we show the key role of fluctuating protrusions on ratchet-like structures in driving NIH3T3 cell migration. We identified the concept of efficient protrusion and an associated direction index. Our analysis of the protrusion statistics facilitated the quantitative prediction of cell trajectories in all investigated conditions. We varied the external cues by changing the adhesive patterns. We also modified the internal cues using drug treatments, which modified the protrusion activity. Stochasticity affects the short- and long-term steps. We developed a theoretical model showing that an asymmetry in the protrusion fluctuations is sufficient for predicting all measures associated with the long-term motion, which can be described as a biased persistent random walk.

Cells as active particles in asymmetric potentials: motility under external gradients.

Cell migration is a crucial event during development and in disease. Mechanical constraints and chemical gradients can contribute to the establishment of cell direction, but their respective roles remain poorly understood. Using a microfabricated topographical ratchet, we show that the nucleus dictates the direction of cell movement through mechanical guidance by its environment. We demonstrate that this direction can be tuned by combining the topographical ratchet with a biochemical gradient of fibronectin adhesion. We report competition and cooperation between the two external cues. We also quantitatively compare the measurements associated with the trajectory of a model that treats cells as fluctuating particles trapped in a periodic asymmetric potential. We show that the cell nucleus contributes to the strength of the trap, whereas cell protrusions guided by the adhesive gradients add a constant tunable bias to the direction of cell motion.

Evaluation of novel dendrimer-gold complex nanoparticles for theranostic application in oncology.

Aim: Despite some successful examples of therapeutic nanoparticles reaching clinical stages, there is still a significant need for novel formulations in order to improve the selectivity and efficacy of cancer treatment. Methods: The authors developed two novel dendrimer-gold (Au) complex-based nanoparticles using two different synthesis routes: complexation method (formulation A) and precipitation method (formulation B). Using a biomimetic cancer-on-a-chip model, the authors evaluated the possible cytotoxicity and internalization by colorectal cancer cells of dendrimer-Au complex-based nanoparticles. Results: The results showed promising capabilities of these nanoparticles for selectively targeting cancer cells and delivering drugs, particularly for the formulation A nanoparticles. Conclusion: This work highlights the potential of dendrimer-Au complex-based nanoparticles as a new strategy to improve the targeting of anticancer drugs.