Cardioprotective properties of OMT-28, a synthetic analog of omega-3 epoxyeicosanoids

OMT-28 is a metabolically robust small molecule developed to mimic the structure and function of omega-3 epoxyeicosanoids. However, it remained unknown to what extent OMT-28 also shares the cardio-protective and anti-inflammatory properties of its natural counterparts. To address this question, we analyzed the ability of OMT-28 to ameliorate hypoxia/reoxygenation (HR)-injury and lipopolysaccharide (LPS)-induced endotoxemia in cultured cardiomyocytes. Moreover, we investigated the potential of OMT-28 to limit functional damage and inflammasome activation in isolated perfused mouse hearts subjected to ischemia/reperfusion (IR) injury. In the HR model, OMT-28 (1 μM) treatment largely preserved cell viability (about 75 vs. 40 % with vehicle) and mitochondrial function as indicated by the maintenance of NAD+/NADH-, ADP/ATP- and respiratory control ratios. Moreover, OMT-28 blocked the HR-induced production of mitochondrial reactive oxygen species. Pharmacological inhibition experiments suggested that Gαi, PI3K, PPARα, and Sirt1 are essential components of the OMT-28 mediated pro-survival pathway. Counteracting inflammatory injury of cardiomyocytes, OMT-28 (1 μM) reduced LPS-induced increases in TNFα protein (by about 85 % vs vehicle) and NF-κB DNA binding (by about 70 % vs. vehicle). In the ex vivo model, OMT-28 improved post-IR myocardial function recovery to reach about 40 % of the baseline value compared to less than 20 % with vehicle. Furthermore, OMT-28 (1 μM) limited IR-induced NLRP3 inflammasome activation similarly like a direct NLRP3 inhibitor (MCC950). Overall, this study demonstrates that OMT-28 possesses potent cardio-protective and anti-inflammatory properties supporting the hypothesis that extending the bioavailability of omega-3 epoxyeicosanoids may improve their prospects as therapeutic agents.

Chapter 6: The Breadth and Limits of Life on Earth

Scientific ideas about the potential existence of life elsewhere in the universe are predominantly informed by knowledge about life on Earth. Over the past ∼4 billion years, life on Earth has evolved into millions of unique species. Life now inhabits nearly every environmental niche on Earth that has been explored. Despite the wide variety of species and diverse biochemistry of modern life, many features, such as energy production mechanisms and nutrient requirements, are conserved across the Tree of Life. Such conserved features help define the operational parameters required by life and therefore help direct the exploration and evaluation of habitability in extraterrestrial environments. As new diversity in the Tree of Life continues to expand, so do the known limits of life on Earth and the range of environments considered habitable elsewhere. The metabolic processes used by organisms living on the edge of habitability provide insights into the types of environments that would be most suitable to hosting extraterrestrial life, crucial for planning and developing future astrobiology missions. This chapter will introduce readers to the breadth and limits of life on Earth and show how the study of life at the extremes can inform the broader field of astrobiology.

ELISA-Based Biosensors

Enzyme-linked immunosorbent assay (ELISA) is by definition a biosensor. However, not all immuno-biosensors involve the use of enzymes, while other biosensors incorporate ELISA as a key signaling component. In this chapter, we review the role of ELISA in signal amplification, integration with microfluidic systems, digital labeling, and electrochemical detection.

Distinctive accumulation of globotriaosylceramide and globotriaosylsphingosine in a mouse model of classic Fabry disease

Fabry disease (FD) is an inherited disease caused by deficient α-galactosidase A activity that is characterized by the accumulation of globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3). Although plasma lyso-Gb3 is a sensitive biomarker of FD, the correlation between its concentration and clinical symptoms remains unclear. To clarify the influence of plasma Gb3 and lyso-Gb3 in a symptomatic Gla ^tm Tg(CAG-A4GALT) FD mouse model, the total contents of Gb3, lyso-Gb3 and their analogs in various organs and plasma were determined in mice with early- (5-week-old) and late-stage (20-week-old) renal dysfunction. A marked increase in total Gb3 content in the heart, kidneys, spleen, liver, small intestine, lungs, brain, and plasma was observed in the 20-week-old mice compared to that in 5-week-old mice. In contrast, the increase in lyso-Gb3 was relatively small, and the total content in the lungs and plasma was unchanged. Lyso-Gb3 analogs {lyso-Gb3(-2) and lyso-Gb3(+18)} and Gb3 analogs {Gb3(-2) and Gb3(+18)} were observed in all organs and plasma at both ages, and the percentages of the analogs were unique to specific organs. The pattern of 37 Gb3 analogs/isoforms of liver Gb3 corresponded well with that of plasma Gb3. Although the analog pattern of plasma lyso-Gb3 did not resemble that of any organ lyso-Gb3, the relative content {lyso-Gb3: lyso-Gb3(-2)} in the sum of all organs corresponded well to that of the plasma at both ages. These data indicate that liver Gb3 may contribute to the plasma Gb3 level, while plasma lyso-Gb3 may be released from all organs, and the capacity of the plasma lyso-Gb3 pool may reach a maximum at an early stage of renal dysfunction.

Structurally diverse fentanyl analogs yield differential locomotor activities in mice

Synthetic narcotics have been implicated as the single greatest contributor to increases in opioid-related fatalities in recent years. This study evaluated the effects of nine fentanyl-related substances that have emerged in the recreational drug marketplace, and for which there are no existing or only limited in vivo data. Adult male Swiss Webster mice were administered fentanyl-related substances and their effects on locomotion as compared to MOR agonist standards were recorded. In locomotor activity tests, morphine (100, 180 mg/kg), buprenorphine (1, 10 mg/kg), fentanyl (1, 10 mg/kg), cyclopropylfentanyl (1, 10 mg/kg), cyclopentylfentanyl (10 mg/kg), (±)-cis-3-methylbutyrylfentanyl (0.1, 1, 10 mg/kg), ortho-methylacetylfentanyl (10 mg/kg), para-chloroisobutyrylfentanyl (100 mg/kg), ocfentanil (1, 10 mg/kg), and ortho-fluoroacrylfentanyl (0.1, 1, 10 mg/kg) elicited significant (p ≤ 0.05) dose-dependent increases in locomotion. However, 2,2,3,3-tetramethylcyclopropylfentanyl did not have any effects on locomotion, even when tested up to 100 mg/kg, and 4'-methylacetylfentanyl (10, 100 mg/kg) significantly decreased locomotion. The rank order of efficacy for stimulating locomotion (maximum effect as a % of fentanyl's maximum effect) for fentanyl-related substances relative to MOR agonist standards was cyclopropylfentanyl (108.84 ± 20.21) > fentanyl (100 ± 15.3) > ocfentanil (79.27 ± 16.92) > morphine (75.9 ± 14.5) > (±)-cis-3-methylbutyrylfentanyl (68.04 ± 10.08) > ortho-fluoroacrylfentanyl (63.56 ± 19.88) > cyclopentylfentanyl (56.46 ± 8.54) > para-chloroisobutyrylfentanyl (22.44 ± 8.51) > buprenorphine (11.26 ± 2.30) > ortho-methylacetylfentanyl (9.45 ± 2.92) > 2,2,3,3-tetramethylcyclopropylfentanyl (6.75 ± 1.43) > 4'-methylacetylfentanyl (3.47 ± 0.43). These findings extend in vivo results from previous reports documenting additional fentanyl related-related substances that stimulate locomotion similar to known abused opioids while also identifying some anomalies.

A versatile and fast-sampling rate wearable analog data logger

We propose a wearable, versatile, and open-source data logger that harvests the capacities of a low-cost microcontroller and enables fast-sampling recording of Analog signals into a microSD card. We describe here the circuit design and an exhaustive list of instructions to build a small, lightweight, and fast sampling rate data logger (up to 5 kHz for simultaneous recording of 3 channels and up to 40 kHz when using a single channel). We provide data analysis instructions, including publicly available scripts to facilitate its replication and customization. As a straightforward proof-of-concept, we tested our device embedded with a three-axial Analog accelerometer and were able to record triple axis acceleration of body movements in high resolution. A Fourier transform followed by a principal component analysis discriminated accurately between body motions of two participants and two types of movement recorded (walking VS running). Our wearable and fast-sampling rate data logger overcomes limits that we identified in previous studies, by being low-cost, capable of fast sampling rate, and easily replicated. Moreover, it can be customized to fit with a wide variety of applications in biomedical research by substituting the three-axial Analog accelerometer with virtually any type of Analog sensors or devices that output Analog signals. •We present a method to build and use a low-cost, fast-sampling rate and wearable Analog data logger, where having an engineering background is not required.•The data logger we present can collect Analog signals from 3 channels simultaneously at 5kHz and up to 40 kHz when using a single channel.•We demonstrate that our data logger can record data from a triple axis Analog accelerometer at 5 kHz, however, signals from virtually any Analog sensor or device that outputs Analog signals can be collected.

Is CEES a good analog of sulfur mustard? Macroscopic aspect, histology, and molecular biology comparisons between sulfur mustard and CEES-induced skin lesions

Sulfur mustard (SM) is a chemical blistering warfare agent affecting multiple organs. SM is an ongoing chemical threat in addition to the accidental risk associated with World War I buried shells. As no specific treatments are available, only symptomatic therapies can be used. To test new medical countermeasures in standard laboratories, analogs such as 2-chloroethyl ethylsulfide (CEES) are currently used, although only a few studies compare its clinical effects with SM. In the present paper, skin lesions induced by SM and CEES are compared in terms of their macroscopic aspects, histology, and molecular biology to evaluate the pertinence of CEES as a SM analog. For this purpose, an in vivo model of CEES vapor exposure, similar to that of SM, is described in this paper. RESULTS: showed similar skin lesions with CEES and SM but with slight differences in the apparition delay and intensity of the lesions. Indeed, SM induced earlier, deeper, and stronger lesions. However, the same healing status was observed at the end of the study period (14 days). In conclusion, CEES appears a relevant analog of SM, leading to similar skin lesions. The CEES vapor exposure model therefore seems suitable for testing new medical countermeasures.

Crew time in a space greenhouse using data from analog missions and Veggie

Crew time requirements for human space exploration missions is as critical as mass, energy, and volume requirements. However, it has only been sporadically recorded in past analog and space missions for plant cultivation. In this retrospective study on crew time data collected in various analog facilities and on the Veggie hardware on ISS, we propose a methodology for efficient categorizing and reporting of crew time in space plant growth systems. Crew time is difficult to capture in operational environments, and this study intends to harmonize these efforts among different locations. This article also provides a current database for required crew time in several plant growth hardware and facilities, on the ISS, and on Earth. These data could serve mission planners as a baseline to establish standardized activities and extrapolate crew time needed to operate future plant growth units. Finally, we discuss how crew time needed for plant cultivation will change in future exploration missions, based on choices made for plant species, watering systems, level of automation, and use of virtual assistants, among others. Crew time will need to be accounted for as a decisive factor to design future space greenhouse modules.

Fentanyl-related substances elicit antinociception and hyperlocomotion in mice via opioid receptors

Synthetic opioids have been implicated as the single greatest contributor to rising drug-related fatalities in recent years. This study evaluated mu-opioid receptor (MOR) mediated effects of seven fentanyl-related substances that have emerged in the recreational drug marketplace, and for which there are no existing or only limited in vivo data. Adult male Swiss Webster mice were administered fentanyl-related substances and their effects on nociception and locomotion as compared to MOR agonist standards were observed. In locomotor activity tests, morphine (100, 180 mg/kg), fentanyl (1, 10 mg/kg), beta-methylfentanyl (10 mg/kg), para-methoxyfentanyl (10 mg/kg), fentanyl carbamate (100 mg/kg), and 3-furanylfentanyl (10 mg/kg), elicited significant (p ≤ 0.05) dose-dependent increases in locomotion. However, para-methylfentanyl and beta'-phenylfentanyl did not produce significant effects on locomotion at doses up to 100 mg/kg and phenylfentanyl (100 mg/kg) significantly decreased locomotion. In warm-water tail-withdrawal tests, all substances produced significant dose-dependent increases in antinociception with increasing ED₅₀ values (95% CI) of fentanyl [0.08 mg/kg (0.04-0.16)] > para-methoxyfentanyl [0.43 mg/kg (0.23-0.77)] > 3-furanylfentanyl [0.51 mg/kg (0.36-0.74)] > beta-methylfentanyl [0.74 mg/kg (0.64-0.85)] > para-methylfentanyl [1.92 mg/kg (1.48-2.45)] > fentanyl carbamate [5.59 mg/kg (4.11-7.54)] > morphine [7.82 mg/kg (5.42-11.0)] > beta'-phenylfentanyl [19.4 mg/kg (11.0-34.4)] > phenylfentanyl [55.2 mg/kg (33.5-93.0)]. Naltrexone (1 mg/kg) increased ED₅₀ values several fold with decreasing magnitudes of para-methylfentanyl (63.1×) > para-methoxyfentanyl (22.5×) > beta'-phenylfentanyl (21.0×) > 3-furanylfentanyl (20.6×) > beta-methylfentanyl (19.2×) > phenylfentanyl (5.23×) > fentanyl (3.95×) > fentanyl carbamate (2.21×) > morphine (1.48×). These findings expand upon in vivo results from previous studies and establish that the effects of these fentanyl related-related substances are at least in part mediated by the MOR.

A matched molecular pair (MMP) approach for selecting analogs suitable for structure activity relationship (SAR)-based read across

One of the most challenging aspects of SAR-based read across is the identification of structurally similar compounds suitable for use as data sources to cover the safety of a target chemical. Matched molecular pair analysis (MMPA) provides a systematic method for mining experimental data for chemical substitutions that may be interpreted in terms of changes in properties. Here we use the relationships between structural substitutions linking a target chemical with an analog determined to be suitable using the expert-judgment based P&G framework of Wu et al. (2010). The relationships are established by applying MMPA to a database of compounds with safety assessed using SAR-based read across to suitable analogs possessing toxicological data. The analysis revealed that only five categories of substitutions per chemical class (aromatic or aliphatic) were necessary to link all molecular pairs. These data are summarized in a workflow outlining a strategy for searching toxicological databases for potential analogs. This approach provides structural comparisons that are interpretable and sensitive to small differences in the local structure of two compounds that may be linked to suitability for read across in contrast to the use of quantitative similarity measures which show little correlation with analog suitability.

AMADEE-18: Vision-Based Unmanned Aerial Vehicle Navigation for Analog Mars Mission (AVI-NAV)

As a part of the AMADEE-18 analog Mars mission, designed to study challenges associated with human-based exploration of the Red Planet, we focused our team efforts on testing means to localize an unmanned aerial vehicle (UAV) on Mars. Robot helicopters, such as the one selected for a technology demonstration as a part of NASA's Mars 2020 mission, are small and their performance is computationally limited. An essential aspect of navigation and path planning of an autonomous helicopter is accurate localization of the robot. In the absence of a global positioning system, a computationally efficient localization technology that can be applied on Mars is visual-inertial odometry (VIO). The AMADEE-18 mission provided an opportunity to test the feasibility of a state-of-the-art VIO algorithm and the camera in a Mars-like analog environment. The flight datasets included different terrain structures that challenged the functionality of VIO algorithms. The experiment has yielded valuable insights into the desired surface structure, texture, and mission times for surface relative navigation of UAV on Mars.

The ScanMars Subsurface Radar Sounding Experiment on AMADEE-18

Terrestrial simulations for crewed missions are critically important for testing technologies and improving methods and procedures for future robotic and human planetary exploration. In February 2018, AMADEE-18 simulated a mission to Mars in the Dhofar region of Oman. During the mission, a field crew coordinated by the Österreichisches Weltraum Forum (OeWF) accomplished several experiments in the fields of astrobiology, space physiology and medicine, geology, and geophysics. Within the scientific payload of AMADEE-18, ScanMars provided geophysical radar imaging of the subsurface at the simulated landing site and was operated by analog astronauts wearing spacesuits during extra-vehicular activities. The analog astronauts were trained to operate a ground-penetrating radar instrument that transmits and then collects radio waves carrying information about the geological setting of the first few meters of the subsurface. The data presented in this work show signal returns from structures down to 4 m depth, associated with the geology of the investigated rocks. Integrating radar data and the analog astronauts' observations of the geology at the surface, it was possible to identify the contact between shallow sediments and bedrock, the local occurrence of conductive soils, and the presence of pebbly materials in the shallow subsurface, which together describe the geology of recent loose sediments overlying an older deformed bedrock. The results obtained by ScanMars confirm that subsurface radar sounding at martian landing sites is key for the geological characterization at shallow depths. The geologic model of the subsurface can be used as the basis for reconstructing palaeoenvironments and paleo-habitats, thus assisting scientific investigations looking for traces of present or past life on the Red Planet. Highlights The ScanMars experiment brings a ground-penetrating radar to the AMADEE-18 simulated Mars mission. The ScanMars radar was operated following procedures and training developed before the mission. Approximately 2000 m of radar data profiles have been acquired during the analog mission. Combining the results for ScanMars, orbital remote sensing data, and first-person observation in the field while wearing spacesuits (analog astronauts), it was possible to generate a geological model at the AMADEE-18 study site.

Unique and Potentially Mars-Relevant Flow Regime and Water Sources at a High Andes-Atacama Site

A field expedition in the High Andes/Atacama Desert region revealed two types of flow-produced structures and a unique flow regime. Gullies somewhat smaller than those on Mars (width: 0.2-1 m, depth: 0.2-0.6 m, length: 4-60 m) were observed as mainly erosional structures. The other flow-related feature called infilled valleys showed activity only in specific, spatially discrete areas during the daytime. The active sections were composed of a source depression where liquid H₂O was produced from subsurface buried sources, which flowed down and percolated into fine-grained infilling material of the valley. Several such active sections could be present along one valley, separated by inactive ones. Three types of H₂O sources fed them: buried snow, surface snow, and ice left behind from the liquid water that had emerged the preceding day. This latter source has not yet been suggested for Mars. Some aspects related to the formation of the gullies and infilled valleys (H₂O budget, albedo, erosional processes) may be similar with the formation processes hypothesized for the recurring slope lineae on Mars. The observed diurnal spatially discrete activity of the infilled valleys is related to the interaction of insolation and mass movement of exhumed subsurface snow, which is also believed to exist on Mars. The Ojos del Salado site is unique in that, despite it being located in the hyperarid High Andes/Atacama Desert region, material from rare snowfall events has been protected due to burial by grains transported by strong winds, supporting ephemeral melting in the long term.

Is a Linear or a Walkabout Protocol More Efficient When Using a Rover to Choose Biologically Relevant Samples in a Small Region of Interest?

We conducted a field test at a potential Mars analog site to provide insight into planning for future robotic missions such as Mars 2020, where science operations must facilitate efficient choice of biologically relevant sampling locations. We compared two data acquisition and decision-making protocols currently used by Mars Science Laboratory: (1) a linear approach, where sites are examined as they are encountered and (2) a walkabout approach, in which the field site is first examined with remote rover instruments to gain an understanding of regional context followed by deployment of time- and power-intensive contact and sampling instruments on a smaller subset of locations. The walkabout method was advantageous in terms of both the time required to execute and a greater confidence in results and interpretations, leading to enhanced ability to tailor follow-on observations to better address key science and sampling goals. This advantage is directly linked to the walkabout method's ability to provide broad geological context earlier in the science analysis process. For Mars 2020, and specifically for small regions to be explored (e.g., <1 km²), we recommend that the walkabout approach be considered where possible, to provide early context and time for the science team to develop a coherent suite of hypotheses and robust ways to test them.

Chalcone synthases (CHSs): the symbolic type III polyketide synthases

Present review provides a thorough insight on some significant aspects of CHSs over a period of about past three decades with a better outlook for future studies toward comprehending the structural and mechanistic intricacy of this symbolic enzyme. Polyketide synthases (PKSs) form a large family of iteratively acting multifunctional proteins that are involved in the biosynthesis of spectrum of natural products. They exhibit remarkable versatility in the structural configuration and functional organization with an incredible ability to generate different classes of compounds other than the characteristic secondary metabolite constituents. Architecturally, chalcone synthase (CHS) is considered to be the simplest representative of Type III PKSs. The enzyme is pivotal for phenylpropanoid biosynthesis and is also well known for catalyzing the initial step of the flavonoid/isoflavonoid pathway. Being the first Type III enzyme to be discovered, CHS has been subjected to ample investigations which, to a greater extent, have tried to understand its structural complexity and promiscuous functional behavior. In this context, we vehemently tried to collect the fragmented information entirely focussed on this symbolic enzyme from about past three-four decades. The aim of this review is to selectively summarize data on some of the fundamental aspects of CHSs viz, its history and distribution, localization, structure and analogs in non-plant hosts, promoter analyses, and role in defense, with an emphasis on mechanistic studies in different species and vis-à-vis mutation-led changes, and evolutionary significance which has been discussed in detail. The present review gives an insight with a better perspective for the scientific community for future studies devoted towards delimiting the mechanistic and structural basis of polyketide biosynthetic machinery vis-à-vis CHS.

Opioid-like antinociceptive and locomotor effects of emerging fentanyl-related substances

The emergence of several fentanyl-related substances in the recreational drug marketplace has resulted in a surge of opioid overdose deaths in the United States. Many of these substances have never been examined in living organisms under controlled conditions. In the present study, seven fentanyl-related substances were tested in adult male Swiss Webster mice for their effects on locomotion and antinociception and compared to those of fentanyl and morphine. In locomotor activity tests, fentanyl (1, 10 mg/kg), morphine (100, 180 mg/kg), isobutyrylfentanyl (10 mg/kg), crotonylfentanyl (10 mg/kg), para-fluorobutyrylfentanyl (10, 100 mg/kg), para-methoxybutyrylfentanyl (10 mg/kg), thiophenefentanyl (100 mg/kg), and benzodioxolefentanyl (0.1 mg/kg) produced significant (p ≤ 0.05) dose-dependent increases in locomotion. Valerylfentanyl, however, was without effects on locomotion up to 100 mg/kg. In warm-water tail-withdrawal tests, all substances produced significant (p ≤ 0.05) dose-dependent increases in antinociception with increasing ED₅₀ values (CI) of isobutyrylfentanyl [0.0768 mg/kg (0.044-0.128)] > fentanyl [0.0800 mg/kg (0.0403-0.164)] > para-methoxybutyrylfentanyl [0.106 mg/kg (0.0516-0.195)] > crotonylfentanyl [0.226 mg/kg (0.176-0.292)] > para-fluorobutyrylfentanyl [0.908 mg/kg (0.459-1.58)] > thiophenefentanyl [4.66 mg/kg (3.65-5.95)] > valerylfentanyl [6.43 mg/kg (3.91-10.5)] > morphine [7.82 mg/kg (5.42-11.0)] > benzodioxolefentanyl [46.3 mg/kg (25.8-83.4)]. Naltrexone (1 mg/kg) increased antinociceptive ED₅₀ values several fold in decreasing magnitudes of isobutyrylfentanyl (233x) > para-methoxybutyrylfentanyl (37.7x) > thiophenefentanyl (34.6x) > valerylfentanyl (11.9x) > para-fluorobutyrylfentanyl (10.9x) > benzodioxolefentanyl (8.42x) > crotonylfentanyl (6.27x) > fentanyl (3.95x) > morphine (1.48x). These findings establish that locomotor and antinociceptive effects of several fentanyl-related substances are similar to those of morphine and fentanyl and are mediated by opioid receptors.

A Flexible Telecommunication Architecture for Human Planetary Exploration Based on the BASALT Science-Driven Mars Analog

There is a synergistic relationship between analog field testing and the deep space telecommunication capabilities necessary for future human exploration. The BASALT (Biologic Analog Science Associated with Lava Terrains) research project developed and implemented a telecommunications architecture that serves as a high-fidelity analog of future telecommunication capabilities for Mars. This paper presents the architecture and its constituent elements. The rationale for the various protocols and radio frequency (RF) link types required to enable an interdisciplinary field mission are discussed, and the performance results from the BASALT field tests are provided. Extravehicular Informatics Backpacks (EVIB) designed for BASALT and tested by human subjects are also discussed, and the proceeding sections show how these prototype extravehicular activity (EVA) information systems can augment future human exploration. The paper concludes with an aggregate analysis of the data product types and data volumes generated, transferred, and utilized by the ground team and explorers over the course of the field deployments.

The BASALT Research Program: Designing and Developing Mission Elements in Support of Human Scientific Exploration of Mars

The articles associated with this Special Collection focus on the NASA BASALT (Biologic Analog Science Associated with Lava Terrains) Research Program, which aims at answering the question, "How do we support and enable scientific exploration during human Mars missions?" To answer this the BASALT team conducted scientific field studies under simulated Mars mission conditions to both broaden our understanding of the habitability potential of basalt-rich terrains on Mars and examine the effects of science on current Mars mission concepts of operations. This article provides an overview of the BASALT research project, from the science, to the operational concepts that were tested and developed, to the technical capabilities that supported all elements of the team's research. Further, this article introduces the 12 articles that are included in this Special Collection.

Opportunities and Challenges of Promoting Scientific Dialog throughout Execution of Future Science-Driven Extravehicular Activity

Science-driven, human spaceflight missions of the future will rely on regular and interactive communication between Earth- and space-based teams during activity in which astronauts work directly on Mars or other planetary surfaces (extravehicular activity, EVA). The Biologic Analog Science Associated with Lava Terrains (BASALT) project conducted simulated human missions to Mars, complete with realistic one-way light time (OWLT) communication latency. We discuss the modes of communication used by the Mars- and Earth-based teams, including text, audio, video, and still imagery. Real-time communication between astronauts in the field (extravehicular, EV) and astronauts in a communication relay station (intravehicular, IV) was broadcast over OWLT, providing important contextual information to the Science Backroom Team (SBT) in Mission Control. Collaborative communication between the Earth- and Mars-based teams, however, requires active communication across latency via the Mission Log. We provide descriptive statistics of text communication between IV and SBT in a high-fidelity, scientifically driven analog for human space exploration. Over an EVA, the SBT sent an average of ∼23 text messages containing recommendations, requests, and answers to questions, while the science-focused IV crew member (IV2) sent an average of ∼38 text messages. Though patterns varied, communication between the IV and SBT teams tended to be highest during ∼50-150 min into the EVA, corresponding to the candidate sample search and presampling instrument survey phases, and then decreased dramatically after minute ∼200 during the sample collection phase. Generally, the IV2 and SBT used ∼4.6 min to craft a reply to a direct question or comment, regardless of message length or OWLT, offering a valuable glimpse into actual time-to-reply. We discuss IV2-SBT communication within the context of case examples from an EVA during which communication failures affected operations in the field. Finally, we offer recommendations for communication practices for use in future analogs and, perhaps, science-driven human spaceflight.

Developing Intra-EVA Science Support Team Practices for a Human Mission to Mars

During the BASALT research program, real (nonsimulated) geological and biological science was accomplished through a series of extravehicular activities (EVAs) under simulated Mars mission conditions. These EVAs were supported by a Mission Support Center (MSC) that included an on-site, colocated Science Support Team (SST). The SST was composed of scientists from a variety of disciplines and operations researchers who provided scientific and technical expertise to the crew while each EVA was being conducted (intra-EVA). SST management and organization developed under operational conditions that included Mars-like communication latencies, bandwidth constraints, and EVA plans that were infused with Mars analog field science objectives. This paper focuses on the SST workspace considerations such as science team roles, physical layout, communication interactions, operational techniques, and work support technology. Over the course of BASALT field deployments to Idaho and Hawai'i, the SST team made several changes of note to increase both productivity and efficiency. For example, new roles were added for more effective management of technical discussions, and the layout of the SST workspace evolved multiple times during the deployments. SST members' reflexive adjustments resulted in a layout that prioritized face-to-face discussions over face-to-data displays, highlighting the importance of interpersonal communication during SST decision-making. In tandem with these workspace adjustments, a range of operational techniques were developed to help the SST manage discussions and information flow under time pressure.

Strategic Planning Insights for Future Science-Driven Extravehicular Activity on Mars

Short-term and long-term science plans were developed as part of the strategic planning process used by the Biologic Analog Science Associated with Lava Terrains (BASALT) science team to conduct two Mars-simulation missions investigating basalt habitability at terrestrial volcanic analog sites in 2016. A multidisciplinary team of scientists generated and codified a range of scientific hypotheses distilled into a Science Traceability Matrix (STM) that defined the set of objectives pursued in a series of extravehicular activity (EVA) campaigns performed across multiple field deployments. This STM was used to guide the pre-deployment selection of sampling stations within the selected Mars analog sites on the Earth based on precursor site information such as multispectral imagery. It also informed selection of hand-held instruments and observational data to collect during EVA to aid sample selection through latency-impacted interaction with an Earth-based Science Support Team. A significant portion of the pre-deployment strategic planning activities were devoted to station selection, ultimately the locations used for sample collection and EVA planning. During development of the EVAs, the BASALT science team identified lessons learned that could be used to inform future missions and analog activities, including the critical need for high-resolution precursor imagery that would enable the selection of stations that could meet the scientific objectives outlined in the STM.

Synthesis of a novel analog of calcitriol and its biological evaluation as antitumor agent

Calcitriol analogs have shown promising potential as compounds to be used in cancer chemotherapy. This report presents the synthesis of a novel vitamin D₃ derivative with an amide and a carboxyl group in its side chain, called ML-344. In addition, we report its in vitro antitumor activity and its in vivo calcemic effects. We demonstrate that the analog decreases cell viability and retards cell migration of different breast, glioblastoma and head and neck cancer cell lines. Additionally, unlike calcitriol, ML-344 does not display citotoxicity to the murine non-malignant mammary cells and human astrocytes. In concordance with the antimigratory effects found in breast cancer cells, ML-344 decreased the invasive capacity and induced a rearrangement of the actin cytoskeleton in the LM3 breast cancer cell line. In relation to the in vivo studies, the analog did not cause hypercalcemic effects in CF1 mice administered daily at 5 μg/Kg of body weight during a period of 264 h. Finally, computational studies were performed to evaluate the potential binding of the analog to the vitamin D receptor and the in silico assays showed that ML-344 is able to bind to VDR with interesting particularities and greater affinity than calcitriol. Altogether, these results suggest that ML-344 has a promising potential as an antitumor agent with a differential effect between tumor and non-malignant cells.

Anesthetic Drug Discovery and Development: A Case Study of Novel Etomidate Analogs

All currently available general anesthetic agents possess potentially lethal side effects requiring their administration by highly trained clinicians. Among these agents is etomidate, a highly potent imidazole-based intravenous sedative-hypnotic that deleteriously suppresses the synthesis of adrenocortical steroids in a manner that is both potent and persistent. We developed two distinct strategies to design etomidate analogs that retain etomidate's potent hypnotic activity, but produce less adrenocortical suppression than etomidate. One strategy seeks to reduce binding to 11β-hydroxylase, a critical enzyme in the steroid biosynthetic pathway, which is potently inhibited by etomidate. The other strategy seeks to reduce the duration of adrenocortical suppression after etomidate administration by modifying the drug's structure to render it susceptible to rapid metabolism by esterases. In this chapter, we describe the methods used to evaluate the hypnotic and adrenocortical inhibitory potencies of two lead compounds designed using the aforementioned strategies. Our purpose is to provide a case study for the development of novel analogs of existing drugs with reduced side effects.

DNA-Based Analog Computing

The field of DNA computation makes use of DNA reactions to do molecular-scale computation. Most works in DNA computation execute digital computations such as evaluation of Boolean circuits. This chapter surveys novel DNA computation methods that execute analog computations, where the inputs and outputs are real values specified by the concentrations of particular DNA strands.

Amylin - Its role in the homeostatic and hedonic control of eating and recent developments of amylin analogs to treat obesity

BACKGROUND

Amylin is a pancreatic β-cell hormone that produces effects in several different organ systems. One of its best-characterized effects is the reduction in eating and body weight seen in preclinical and clinical studies. Amylin activates specific receptors, a portion of which it shares with calcitonin gene-related peptide (CGRP). Amylin's role in the control of energy metabolism relates to its satiating effect, but recent data indicate that amylin may also affect hedonic aspects in the control of eating, including a reduction of the rewarding value of food. Recently, several amylin-based peptides have been characterized. Pramlintide (Symlin^®) is currently the only one being used clinically to treat type 1 and type 2 diabetes. However other amylin analogs with improved pharmacokinetic properties are being considered as anti-obesity treatment strategies. Several other studies in obesity have shown that amylin agonists could also be useful for weight loss, especially in combination with other agents.

SCOPE OF REVIEW

This review will briefly summarize amylin physiology and pharmacology and then focus on amylin's role in food reward and the effects of amylin analogs in pre-clinical testing for anti-obesity drugs.

CONCLUSION

We propose here that the effects of amylin may be homeostatic and hedonic in nature.

Effect of nanolayering of calcium salts of phosphoric acid ester monomers on the durability of resin-dentin bonds

To investigate the contribution of nanolayering on resin-dentin bond durability, two phosphoric acid ester resin monomers, 10-methacryloyloxy-decyl-dihydrogen-phosphate (10-MDP) or its analog, methacryloyloxy-penta-propyleneglycol-dihydrogen-phosphate (MDA), were examined for their affinity for mineralized dentin powder in a column chromatography setup. Hydroxyapatite (HA) powder was dispersed in experimental primers consisting of 10-MDP or MDA solvated in ethanol/water and examined with FTIR, (31)P MAS-NMR and XPS. Light-curable 10-MDP or MDA primers were used for bonding to dentin, and examined after 24h or one-year of water-aging by TEM for evidence of nanolayering, and for microtensile bond strength evaluation. Primer-bonded dentin was examined by thin-film XRD to identify short-range order peaks characteristic of nanolayering of resin monomer-Ca salts. Although 10-MDP had better affinity for mineralized dentin than MDA, both monomers completely eluted from the mineralized dentin powder column using ethanol-water as mobile phase, indicating that the adsorption processes were reversible. This finding was supported by chemoanalytic data. XRD of 10-MDP-bonded dentin showed three diffraction peaks hat were absent from MDA-bonded dentin. Nanolayering was identified by TEM in 10-MDP-bonded dentin, but not in MDA-bonded dentin. Significant drop in bond strength (in MPa) was observed for both groups after one-year of water-aging compared with 24-h: 10-MDP group from 48.3±6.3 to 37.4±4.6; MDA group from 50.7±5.0 to 35.7±3.8 (P<0.05), with no significant difference between the two groups at the same time-point. Because both functional monomer-primed, resin-bonded dentin exhibited similar bond strength decline after water-aging, presence of nanolayering is unlikely to contribute to the overall resin-dentin bond durability.

STATEMENT OF SIGNIFICANCE

The durability of resin-dentin bonds in 10-MDP containing self-etching adhesives has been anecdotally attributed to the presence of nanolayering of 10-MDP-calcium salts in the resin-dentin interface. Results of the present work indicate that such a claim cannot be justified. Complete elution of the phosphoric acid ester monomer from mineralized dentin powder in the column chromatography experiments using ethanol-water mobile phase to simulate the solvent mixture employed in most 10-MDP-containing dentin adhesives further challenges the previously proposed adhesion-decalcification concept that utilizes chemical bonding of phosphoric acid ester monomers to apatite as a bonding mechanism in 10-MDP containing dentin adhesives.

Ceramide channel: Structural basis for selective membrane targeting

A ceramide commonly found in mammalian cells, C16-ceramide (N-palmitoyl-d-erythro-sphingosine), is capable of forming large, protein-permeable channels in the mitochondrial outer membrane (MOM). However, C16-ceramide is unable to permeabilize the plasma membrane of erythrocytes. This specificity is unexpected considering that ceramide forms channels in simple phosphoglycerolipid membranes. Synthetic analogs of C16-ceramide with targeted changes at each of the functional regions of the molecule including methylation, altered hydrocarbon chain length, and changes in the stereochemistry, were tested to probe the role of ceramide's molecular features on its ability to form channels in these two different membrane types. The ability to permeabilize the MOM was relatively insensitive to modifications of the various functional groups of ceramide whereas the same modifications resulted in plasma membrane permeabilization (a gain of function rather than a loss of function). Some analogs (ceramine, NBD-labeled ceramide, C18,1 ceramide) gained another function, the ability to inhibit cytochrome oxidase. The gain of deleterious functions indicates that constraints on the structure of ceramide that is formed by the cell's synthetic machinery includes the avoidance of deleterious interactions. We propose that the specific structure of ceramide limits the size of its interactome (both proteins and lipids) thus reducing the likelihood of unwanted side effects.

Inhibition of β-catenin and STAT3 with a curcumin analog suppresses gastric carcinogenesis in vivo

BACKGROUND

Potent chemotherapy for advanced gastric cancer has not been completely established. Many molecularly targeted therapies are under investigation, but their therapeutic outcomes are not promising because they do not target specific and/or critical targets of gastric carcinogenesis. Although the molecular basis of gastric carcinogenesis remains poorly understood, nuclear localization of β-catenin was observed in approximately 50 % of gastric cancer specimens. Recent studies have suggested that activation of signal transducer and activator of transcription 3 (STAT3) contributes to gastric carcinogenesis in a mouse model. A newly synthesized curcumin analog has inhibitory potential against β-catenin and STAT3.

METHODS

Using a transgenic mouse model of gastric cancer in which β-catenin, cyclooxygenase 2, and microsomal prostaglandin E synthase 1 activation is induced, we examined a curcumin analog with the most enhanced potential for treating gastric cancer through oral administration. Inhibition of these targets was demonstrated using microarray and immunohistochemical analyses.

RESULTS

The curcumin analog GO-Y031 decreased the incidence of gastric carcinogenesis to 54.5 % of that of the control (50.0 % vs 91.7 %, p = 0.043), and tumor size was reduced to 51.6 % of that of the control (1.6 mm vs 3.1 mm, p = 0.03). β-Catenin and STAT3 levels were suppressed to 26.2 % (p = 0.00023) and 44.8 % (p = 0.025), respectively, of those of the control. Moreover, macrophage infiltration was suppressed with GO-Y031.

CONCLUSION

β-Catenin and STAT3 can be pharmacologically inhibited in vivo with a curcumin analog, which effectively inhibits β-catenin and STAT3.

A Novel Long-Acting Glucagon-Like Peptide-1 Agonist with Improved Efficacy in Insulin Secretion and β-Cell Growth

BACKGROUND

Glucagon-like peptide-1 (GLP-1) is an incretin hormone produced by cleavage of proglucagon in intestinal L-cells. In the pancreas, GLP-1 stimulates post-prandial insulin secretion, promotes insulin biosynthesis, and improves insulin sensitivity. Because of its insulinotropic activity, GLP-1 has been considered a good candidate drug for treatment of diabetes mellitus. However, clinical use of GLP-1 has been limited by its short half-life, as a result of rapid degradation by dipeptidyl peptidase-IV (DPP-IV).

METHODS

We designed a novel GLP-1 analog, Xenopus GLP-1 (xGLP)-E4. The Ala residue in the second position of xGLP was replaced with a Ser residue to increase the half-life in the body. The C-terminal tail of exendin-4 was added to enhance the binding affinity for the GLP-1 receptor (GLP1R). The potency of GLP-1 and its analogs was determined by luciferase assay. The stability of GLP1R agonists was evaluated by determining the activity of agonists that had been preincubated in the presence of fetal bovine serum, which contains innate DPP-IV activity. The effects of xGLP-E4 on insulin secretion and β-cell growth were investigated using insulin enzyme-linked immunosorbent assay and cell counting.

RESULTS

xGLP-E4 exhibited improved stability against DPP-IV activity and increased potency to GLP1R, compared with GLP-1. An increase in glucose-dependent insulin secretion was observed in xGLP-E4-treated pancreatic β-cells. The effect of xGLP-E4 on β-cell growth was greater than that of GLP-1.

CONCLUSION

We developed a novel GLP-1 analog, xGLP-E4, that shows prolonged longevity and improved efficacy. This analog is a potential candidate for treatment of type 2 diabetes.

Multiple bonds for the lipid interest

Polyene lipids and alkyne lipids allow study of lipid organization, dynamics and metabolism. Both types of lipids contain multiple bonds as the essential functional group, leading to minimal disturbance of the hydrophobic properties on which the characteristic behavior of lipids is based. Polyene lipids can directly be traced due to their intrinsic fluorescence, while alkyne lipids need the copper-catalyzed click reaction to an azido-reporter for detection. This review describes recent developments in synthesis and application of both types of lipid analogs with emphasis on metabolic tracing and microscopy imaging. This article is part of a Special Issue entitled Tools to study lipid functions.

Imatinib analogs as potential agents for PET imaging of Bcr-Abl and c-KIT expression at a kinase level

We synthesized two series of imatinib mesylate (STI-571) analogs to develop a Bcr-Abl and c-KIT receptor-specific labeling agent for positron emission tomography (PET) imaging to measure Bcr-Abl and c-KIT expression levels in a mouse model. The methods of molecular modeling, synthesis of STI-571 and its analogs, in vitro kinase assays, and radiolabeling are described. Molecular modeling revealed that these analogs bind the same Bcr-Abl and c-KIT binding sites as those bound by STI-571. The analogs potently inhibit the tyrosine kinase activity of Bcr-Abl and c-KIT, similarly to STI-571. [(18)F]-labeled STI-571 was prepared with high specific activity (75 GBq/μmol) by nucleophilic displacement and an average radiochemical yield of 12%. [(131)I]-labeled STI-571 was prepared with high purity (>95%) and an average radiochemical yield of 23%. The uptake rates of [(18)F]-STI-571 in K562 cells expressing Abl and in U87WT cells overexpressing c-KIT were significantly higher than those in the U87 cell and could be inhibited by STI-71 (confirming the specificity of uptake). PET scans of K562 and U87WT tumor-bearing mice with [(18)F]-STI-571 as a contrast agent showed visible tumor uptake and tumor-to-non-target contrast.

A new device for impression transfer for non-parallel endosseus implants

The three-dimensional orientation of dental implant is transferred to a model by means of transfer device and impression material. If more than one implant is inserted and fixtures are not perfectly parallel, the impression may become distorted when removed from the mouth. In this case, a transfer that can be disengaged from the internal implant-abutment connection and removed together with the tray could be useful. An impression transfer device composed of a proper transfer, an inner hexagon and a central screw is described. When the central screw and the hexagon are removed, the proper transfer is free to move horizontally and the tray can be removed from the mouth without distortion of the impression material.