Neural Tissue-Like, not Supraphysiological, Electrical Conductivity Stimulates Neuronal Lineage Specification through Calcium Signaling and Epigenetic Modification.

Electrical conductivity is a pivotal biophysical factor for neural interfaces, though optimal values remain controversial due to challenges isolating this cue. To address this issue, conductive substrates made of carbon nanotubes and graphene oxide nanoribbons, exhibiting a spectrum of conductivities from 0.02 to 3.2 S m-1, while controlling other surface properties is designed. The focus is to ascertain whether varying conductivity in isolation has any discernable impact on neural lineage specification. Remarkably, neural-tissue-like low conductivity (0.02-0.1 S m-1) prompted neural stem/progenitor cells to exhibit a greater propensity toward neuronal lineage specification (neurons and oligodendrocytes, not astrocytes) compared to high supraphysiological conductivity (3.2 S m-1). High conductivity instigated the apoptotic process, characterized by increased apoptotic fraction and decreased neurogenic morphological features, primarily due to calcium overload. Conversely, cells exposed to physiological conductivity displayed epigenetic changes, specifically increased chromatin openness with H3acetylation (H3ac) and neurogenic-transcription-factor activation, along with a more balanced intracellular calcium response. The pharmacological inhibition of H3ac further supported the idea that such epigenetic changes might play a key role in driving neuronal specification in response to neural-tissue-like, not supraphysiological, conductive cues. These findings underscore the necessity of optimal conductivity when designing neural interfaces and scaffolds to stimulate neuronal differentiation and facilitate the repair process.

Hematopoietic Stem Cells and Their Niche in Bone Marrow.

Extensive research has explored the functional correlation between stem cells and progenitor cells, particularly in blood. Hematopoietic stem cells (HSCs) can self-renew and regenerate tissues within the bone marrow, while stromal cells regulate tissue function. Recent studies have validated the role of mammalian stem cells within specific environments, providing initial empirical proof of this functional phenomenon. The interaction between bone and blood has always been vital to the function of the human body. It was initially proposed that during evolution, mammalian stem cells formed a complex relationship with the surrounding microenvironment, known as the niche. Researchers are currently debating the significance of molecular-level data to identify individual stromal cell types due to incomplete stromal cell mapping. Obtaining these data can help determine the specific activities of HSCs in bone marrow. This review summarizes key topics from previous studies on HSCs and their environment, discussing current and developing concepts related to HSCs and their niche in the bone marrow.

A Marine Collagen-Based 3D Scaffold for In Vitro Modeling of Human Prostate Cancer Niche and Anti-Cancer Therapeutic Discovery.

Recently, the need to develop a robust three-dimensional (3D) cell culture system that serves as a valuable in vitro tumor model has been emphasized. This system should closely mimic the tumor growth behaviors observed in vivo and replicate the key elements and characteristics of human tumors for the effective discovery and development of anti-tumor therapeutics. Therefore, in this study, we developed an effective 3D in vitro model of human prostate cancer (PC) using a marine collagen-based biomimetic 3D scaffold. The model displayed distinctive molecular profiles and cellular properties compared with those of the 2D PC cell culture. This was evidenced by (1) increased cell proliferation, migration, invasion, colony formation, and chemoresistance; (2) upregulated expression of crucial multidrug-resistance- and cancer-stemness-related genes; (3) heightened expression of key molecules associated with malignant progressions, such as epithelial-mesenchymal transition transcription factors, Notch, matrix metalloproteinases, and pluripotency biomarkers; (4) robust enrichment of prostate cancer stem cells (CSCs); and (5) enhanced expression of integrins. These results suggest that our 3D in vitro PC model has the potential to serve as a research platform for studying PC and prostate CSC biology, as well as for screening novel therapies targeting PC and prostate CSCs.

Leukemic Stem Cells and Hematological Malignancies.

The association between leukemic stem cells (LSCs) and leukemia development has been widely established in the context of genetic alterations, epigenetic pathways, and signaling pathway regulation. Hematopoietic stem cells are at the top of the bone marrow hierarchy and can self-renew and progressively generate blood and immune cells. The microenvironment, niche cells, and complex signaling pathways that regulate them acquire genetic mutations and epigenetic alterations due to aging, a chronic inflammatory environment, stress, and cancer, resulting in hematopoietic stem cell dysregulation and the production of abnormal blood and immune cells, leading to hematological malignancies and blood cancer. Cells that acquire these mutations grow at a faster rate than other cells and induce clone expansion. Excessive growth leads to the development of blood cancers. Standard therapy targets blast cells, which proliferate rapidly; however, LSCs that can induce disease recurrence remain after treatment, leading to recurrence and poor prognosis. To overcome these limitations, researchers have focused on the characteristics and signaling systems of LSCs and therapies that target them to block LSCs. This review aims to provide a comprehensive understanding of the types of hematopoietic malignancies, the characteristics of leukemic stem cells that cause them, the mechanisms by which these cells acquire chemotherapy resistance, and the therapies targeting these mechanisms.

Advancement in Cancer Vasculogenesis Modeling through 3D Bioprinting Technology.

Cancer vasculogenesis is a pivotal focus of cancer research and treatment given its critical role in tumor development, metastasis, and the formation of vasculogenic microenvironments. Traditional approaches to investigating cancer vasculogenesis face significant challenges in accurately modeling intricate microenvironments. Recent advancements in three-dimensional (3D) bioprinting technology present promising solutions to these challenges. This review provides an overview of cancer vasculogenesis and underscores the importance of precise modeling. It juxtaposes traditional techniques with 3D bioprinting technologies, elucidating the advantages of the latter in developing cancer vasculogenesis models. Furthermore, it explores applications in pathological investigations, preclinical medication screening for personalized treatment and cancer diagnostics, and envisages future prospects for 3D bioprinted cancer vasculogenesis models. Despite notable advancements, current 3D bioprinting techniques for cancer vasculogenesis modeling have several limitations. Nonetheless, by overcoming these challenges and with technological advances, 3D bioprinting exhibits immense potential for revolutionizing the understanding of cancer vasculogenesis and augmenting treatment modalities.

Commemoration of body donors in a religiously diverse society: A tale of two Korean medical schools.

Although a diversity of religions exists in South Korea, with Buddhism and Christianity (Protestantism and Catholicism) being the two main faiths, Korean beliefs are deeply rooted in Confucianism. Despite the notion that the Confucian norm of filial piety discourages body donation to medical science, there has been a mindset shift in favor of body donation, driven by a heightened awareness of the body bequest programs and the care and dignity accorded to the altruistic body donors, together with the institution of commemorative services to honor them. As spirituality and religion are known to be factors that influence body donation, how religious- and non-religious-based memorial services are held to honor the donors as exemplified by two Korean medical schools-from a public university with no religious affiliation and from a Protestant-based university-are described here. The key concept of expressing gratitude and respect for the donors and their family members has positively impacted body bequest programs in this multi-religious society. Commemorative services held to pay tribute to the altruistic body donors may play an important role in inspiring a humanistic spirit in students, regardless of religious or non-religious beliefs, as exemplified by the two Korean medical schools. The takeaway here is that the elevation of spirituality in memorial services effectively resonates with society, thereby demonstrating the impact of spiritual principles independent of religious influence.

Effectiveness and Safety of Meridian Activation Remedy System for Alleviating Motor Symptoms in Parkinson's Disease: an Observational Study.

Background: Parkinson's disease (PD) lacks disease-modifying drugs or sustainable interventions, creating an unmet treatment need. Investigating complementary and alternative medicines aims to improve PD patients' quality of life by alleviating symptoms and delaying the course of the disease. Objectives: In this single-center, prospective, observational, single-arm study, we aimed to assess the effectiveness and safety of acupuncture combined with exercise therapy and the Meridian Activation Remedy System (MARS). Methods: From March to October 2021, 13 PD patients with Hoehn and Yahr stages 1 to 3 were recruited. For 8 weeks, MARS intervention was carried out twice a week. T-statistics were used to evaluate functional near-infrared spectroscopy (fNIRS) and GAITRite outcomes. All of the remaining outcome variables were evaluated using the Wilcoxon signed-rank test. Results: The MARS intervention significantly reduced PD patients' Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDSUPDRS) Part III score (from 20.0 ± 11.8 to 8.8 ± 5.5, p = 0.003), 10-meter walk test speed (from 9.5 ± 1.8 to 8.7 ± 1.3 seconds, p = 0.040), and timed up and go time (from 9.8 ± 1.8 to 8.9 ± 1.4 seconds, p = 0.040). Moreover, the MDS-UPDRS Part II, fNIRS hemodynamics, 360-degree turn test, fall efficacy scale, and Parkinson's Disease Questionnaire 39 scores improved but not significantly. All participants completed the 8-week intervention without any adverse reactions. Conclusion: An 8-week MARS intervention improved motor symptoms in PD patients. In particular, improvements in UPDRS Part III scores exhibited large clinically important differences. The findings are encouraging, and a randomized controlled trial will be conducted to determine the efficacy and cost-effectiveness of MARS intervention.

The efficacy of slow-rate ventriculolumbar perfusion chemotherapy for leptomeningeal carcinomatosis: a phase II study.

PURPOSE: This study aimed to evaluate the symptomatic response and side effects of ventriculolumbar perfusion (VLP) methotrexate chemotherapy with a low perfusion rate in patients with leptomeningeal metastasis. METHODS: Patients in a single-arm, two-stage phase II trial based on Simon's minimax design received VLP with a reduced (15 cc/h) perfusion rate with the purpose of decreasing constitutional side effects such as nausea/vomiting, insomnia, and confusion. The primary outcome was control of increased intracranial pressure (ICP). The secondary outcome was an occurrence of side effects. The results were compared with those of a previous trial of VLP with a 20-cc/h perfusion rate. RESULTS: Total 90 patients were enrolled. Out of 65 patients with increased ICP, 32 achieved normalized ICP after VLP chemotherapy (bias-adjusted response rate = 51%). The incidence of moderate-to-severe nausea/vomiting was reduced to 46% from 64% in the previous study, and that of sleep disturbance was increased to 13% from 9%, but both failed to reach statistical significance. The incidence of moderate-to-severe confusion was significantly reduced to 12% from 23% in the previous study (p = 0.04). Median overall survival was better among patients with controlled ICP than among those who remained with increased ICP (193 days vs. 94 days, p = 0.013). CONCLUSION: Compared with a higher perfusion rate, the low perfusion rate failed to provide non-inferior ICP control or improved side effects, except for confusion. The relationship between VLP perfusion rate and ICP control needs to be evaluated in future trials adjusting for bias from uncompleted protocol due to poor general condition.