Protective roles of ascorbic acid in oxidative stress induced by depletion of superoxide dismutase in vertebrate cells.

Superoxide dismutases (SODs) are antioxidant proteins that convert superoxide to hydrogen peroxide. In vertebrate cells, SOD1 is mainly present in the cytoplasm, with small levels also found in the nucleus and mitochondrial intermembrane space, and SOD2 is present in the mitochondrial matrix. Previously, the authors conditionally disrupted the SOD1 or SOD2 gene in DT40 cells and found that depletion of SOD1 caused lethality, while depletion of SOD2 led to growth retardation. The observations from previous work showed that the lethality observed in SOD1-depleted cells was completely rescued by ascorbic acid. Ascorbic acid is a water-soluble antioxidant present in biological fluids; however, the exact target for its antioxidant effects is not known. In this study, the authors demonstrated that ascorbic acid offset growth defects observed in SOD2-depleted cells and also lowered mitochondrial superoxide to physiological levels in both SOD1- or SOD2-depleted cells. Moreover, depletion of SOD1 or SOD2 resulted in the accumulation of intracellular oxidative stress, and this increased oxidative stress was reduced by ascorbic acid. Taken together, this study suggests that ascorbic acid can be applied as a nontoxic antioxidant that mimics the functions of cytoplasmic and mitochondrial SODs

Growth of Acetaminophen Polymorphic Crystals and Solution-Mediated Phase Transition from Trihydrate to Form II in Agarose Gel

The growth of acetaminophen polymorphic crystals and the solution-mediated phase transition from trihydrate to form II in agarose gel were investigated. The form II crystals grown in gels, presumably because of the agarose content, dissolved less rapidly at high temperatures and were more stable than in water. The trihydrate crystals in the gel were also expected to be stabilized by containing agarose, but in fact the fine morphology resulted in reduced stability. The solution-mediated phase transition from trihydrate to form II via form II seeding took longer in the gel because the gel slowed down the dissolution of the trihydrate by hindering the dispersion of the form II seeds and delayed the growth of form II by reducing the diffusion rate of the molecules dissolved from the trihydrate. Delays in solution-mediated phase transition and changes in stability for crystals grown in gels indicate the effectiveness of gels in controlling polymorphisms in pharmaceutical compounds.Nishigaki A., Maruyama M., Tanaka S.I., et al. Growth of acetaminophen polymorphic crystals and solution-mediated phase transition from trihydrate to form II in agarose gel. Crystals 11, 1069 (2021); https://doi.org/10.3390/cryst11091069

Decision analysis for transplant candidates with primary myelofibrosis in the ruxolitinib era

The recent progress with ruxolitinib treatment might improve quality-of-life as well as overall survival in patients with primary myelofibrosis (PMF). Therefore, the optimal timing of allogeneic hematopoietic cell transplantation (HCT) remains to be elucidated in the ruxolitinib era. We constructed a Markov model to simulate the 5-year clinical course of transplant candidates with PMF, and compared outcomes between immediate HCT and delayed HCT after ruxolitinib failure. Since older age was associated with an increased risk of mortality, we analyzed patients aged < 60 and ≥ 60 separately in subgroup analyses. The expected life years was consistently longer in delayed HCT after ruxolitinib failure regardless of patient age. Regarding quality-adjusted life years (QALYs), a baseline analysis showed that immediate HCT was inferior to delayed HCT after ruxolitinib failure (2.19 versus 2.26). In patients aged < 60, immediate HCT was equivalent to delayed HCT after ruxolitinib failure (2.31 versus 2.31). On the other hand, in patients aged ≥ 60, immediate HCT was inferior to delayed HCT after ruxolitinib failure (1.98 versus 2.21). A one-way sensitivity analysis showed that the utility of being alive without chronic graft-versus-host disease after immediate HCT was the most influential parameter for QALYs, and that a value higher than 0.836 could reverse the superiority of delayed HCT after ruxolitinib failure. As a result, delayed HCT after ruxolitinib failure is expected to be superior to immediate HCT, especially in patients aged ≥ 60, and is also a promising strategy even in those aged < 60

The first chick brain with non-invasively embedded beads: a foundation for the automation of brain research

Abstract Background The automation of biotechnology, such as next-generation DNA sequencing, revolutionarily provides massive amounts of data and integrates various research fields. By contrast, many non-automated brain research fields are not interconnected with one other. In this study, we developed a basis for the automation of brain research. Two major technical barriers for the automation of brain research in vertebrates are the necessity for skull incision and a precise inoculation system for probes, devices, and electrodes in defined brain locations. Results The former barrier in the background was overcome by inoculating probes into the future brain area of chick embryos before skull formation. Fluorescent micro-beads that mimic probes were inoculated into the future brain area of chick embryos, and 20% of the manipulated embryos hatched, with 71% of the hatched chicks containing multiple beads in their brains. Conclusions With this technique, beads are embedded inside the brain without skull incision, promising a novel non-invasive method that overcomes the drawbacks associated with traditional invasive brain manipulation

Metastable Crystallization by Drop Impact

It has been reported that cavitation bubbles (air–liquid interface) by femtosecond laser and ultrasonic irradiations are effective for metastable phase crystallization in polymorph control. It has also been noted that cavitation bubbles are generated by mechanical shock when dropping a vial. Here we describe the crystallization of acetaminophen by drop impact. In the condition where spontaneous nucleation did not occur, the drop impact produced the metastable form (form II) and trihydrate. This supports the potency of the air–liquid interface in metastable phase formation. Furthermore, crystallization by drop impact is a completely new phenomenon, and new developments are expected in the future

Metastable Crystallization by Drop Impact

It has been reported that cavitation bubbles (air&ndash;liquid interface) by femtosecond laser and ultrasonic irradiations are effective for metastable phase crystallization in polymorph control. It has also been noted that cavitation bubbles are generated by mechanical shock when dropping a vial. Here we describe the crystallization of acetaminophen by drop impact. In the condition where spontaneous nucleation did not occur, the drop impact produced the metastable form (form II) and trihydrate. This supports the potency of the air&ndash;liquid interface in metastable phase formation. Furthermore, crystallization by drop impact is a completely new phenomenon, and new developments are expected in the future