Crawling Magnetic Robot to Perform a Biopsy in Tubular Environments by Controlling a Magnetic Field

We developed a crawling magnetic robot (CMR), which can stably navigate and perform biopsies remotely in tubular environments by controlling a magnetic field. The CMR is composed of a crawling part and a biopsy part. The crawling part allows the CMR to crawl forward and backward via an asymmetric friction force generated by an external precessional magnetic field. The biopsy part closes or opens the cover of a needle to use the biopsy needle selectively with the control of the external precessional magnetic field. The cover of the biopsy part prevents damage to the tubular environments because the biopsy needle is inside the cover while the CMR is navigating. We developed the design of the proposed CMR using magnetic torque constraints and a magnetic force constraint, and then we fabricated the CMR with three-dimensional printing technology. Finally, we conducted an experiment to measure the CMR’s puncturing force with a load cell and conducted an experiment in a Y-shaped watery glass tube with pseudo-tissue to verify the crawling motion, the uncovering and covering motion of the biopsy needle, and the CMR’s ability to extract tissue with the biopsy needle

Electrical Optimization Method Based on a Novel Arrangement of the Magnetic Navigation System with Gradient and Uniform Saddle Coils

The magnetic navigation system (MNS) with gradient and uniform saddle coils is an effective system for manipulating various medical magnetic robots because of its compact structure and the uniformity of its magnetic field and field gradient. Since each coil of the MNS was geometrically optimized to generate strong uniform magnetic field or field gradient, it is considered that no special optimization is required for the MNS. However, its electrical characteristics can be still optimized to utilize the maximum power of a power supply unit with improved operating time and a stronger time-varying magnetic field. Furthermore, the conventional arrangement of the coils limits the maximum three-dimensional (3D) rotating magnetic field. In this paper, we propose an electrical optimization method based on a novel arrangement of the MNS. We introduce the objective functions, constraints, and design variables of the MNS considering electrical characteristics such as resistance, current density, and inductance. Then, we design an MNS using an optimization algorithm and compare it with the conventional MNS; the proposed MNS generates a magnetic field or field gradient 22% stronger on average than that of the conventional MNS with a sevenfold longer operating time limit, and the maximum three-dimensional rotating magnetic field is improved by 42%. We also demonstrate that the unclogging performance of the helical robot improves by 54% with the constructed MNS

The Effect of Lactobacillus acidophilus YT1 (MENOLACTO) on Improving Menopausal Symptoms: A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

This study evaluated the efficacy of Lactobacillus acidophilus YT1 (MENOLACTO) for alleviating menopausal symptoms. This study was a multi-center, randomized, double-blinded, placebo-controlled clinical trial involving female subjects (ages: 40–60 years) with menopausal symptoms and a Kupperman index (KMI) score ≥ 20. Subjects were administered 1 × 108 CFU/day MENOLACTO or placebo, with the primary endpoint being total KMI score, and the effect of secondary endpoints on alleviating menopausal symptoms according to individual categories of the modified KMI, as well as a quality of life questionnaire (MENQOL questionnaire). After 12 weeks, total KMI scores decreased significantly, demonstrating improved menopausal symptoms relative to placebo along with improved modified KMI scores. Additionally, quality of life, according to the MENQOL questionnaire, significantly improved in all four symptoms—physical, psychosocial, vasomotor, and sexual symptoms. Moreover, we observed no significant difference between the two groups or significant changes in blood follicle-stimulating hormone and estradiol levels or endometrial thickness. These results demonstrated that MENOLACTO alleviated menopausal symptoms without notable side effects and improved quality of life, suggesting its efficacy as an alternative supplement to alleviate menopausal symptoms in women ineligible for hormonal therapy

Activation of Astrocytic μ-Opioid Receptor Causes Conditioned Place Preference

© 2019 The AuthorsThe underlying mechanisms of how positive emotional valence (e.g., pleasure) causes preference of an associated context is poorly understood. Here, we show that activation of astrocytic μ-opioid receptor (MOR) drives conditioned place preference (CPP) by means of specific modulation of astrocytic MOR, an exemplar endogenous Gi protein-coupled receptor (Gi-GPCR), in the CA1 hippocampus. Long-term potentiation (LTP) induced by a subthreshold stimulation with the activation of astrocytic MOR at the Schaffer collateral pathway accounts for the memory acquisition to induce CPP. This astrocytic MOR-mediated LTP induction is dependent on astrocytic glutamate released upon activation of the astrocytic MOR and the consequent activation of the presynaptic mGluR1. The astrocytic MOR-dependent LTP and CPP were recapitulated by a chemogenetic activation of astrocyte-specifically expressed Gi-DREADD hM4Di. Our study reveals that the transduction of inhibitory Gi-signaling into augmented excitatory synaptic transmission through astrocytic glutamate is critical for the acquisition of contextual memory for CPP. Nam et al. demonstrate that activation of hippocampal astrocytic μ-opioid receptor causes glutamate release, which increases the release probability by neuronal presynaptic mGluR1 activation and potentiates synaptic plasticity at the SC-CA1 pathway. This enhanced synaptic transmission and synaptic plasticity account for the acquisition of memory associated with CPP11Nsciescopu

Control of hippocampal prothrombin kringle-2 (pKr-2) expression reduces neurotoxic symptoms in five familial Alzheimer's disease mice

Background and Purpose: There is a scarcity of information regarding the role of prothrombin kringle-2 (pKr-2), which can be generated by active thrombin, in hippocampal neurodegeneration and Alzheimer's disease (AD). Experimental Approach: To assess the role of pKr-2 in association with the neurotoxic symptoms of AD, we determined pKr-2 protein levels in post-mortem hippocampal tissues of patients with AD and the hippocampi of five familial AD (5XFAD) mice compared with those of age-matched controls and wild-type (WT) mice, respectively. In addition, we investigated whether the hippocampal neurodegeneration and object memory impairments shown in 5XFAD mice were mediated by changes to pKr-2 up-regulation. Key Results: Our results demonstrated that pKr-2 was up-regulated in the hippocampi of patients with AD and 5XFAD mice, but was not associated with amyloid-β aggregation in 5XFAD mice. The up-regulation of pKr-2 expression was inhibited by preservation of the blood–brain barrier (BBB) via addition of caffeine to their water supply or by treatment with rivaroxaban, an inhibitor of factor Xa that is associated with thrombin production. Moreover, the prevention of up-regulation of pKr-2 expression reduced neurotoxic symptoms, such as hippocampal neurodegeneration and object recognition decline due to neurotoxic inflammatory responses in 5XFAD mice. Conclusion and Implications: We identified a novel pathological mechanism of AD mediated by abnormal accumulation of pKr-2, which functions as an important pathogenic factor in the adult brain via blood brain barrier (BBB) breakdown. Thus, pKr-2 represents a novel target for AD therapeutic strategies and those for related conditions. © 2021 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.TRU