1,196 research outputs found
Regular dipyridamole therapy produces sustained protection against cardiac ischemia-reperfusion injury: is it time to revisit PARIS?
BACKGROUND: Increased activated Akt and eNOS expression coincide with this persistent cardioprotection. Emergent coronary reperfusion therapies are rarely carried out before considerable myocardial injury has occurred. Moreover, reperfusion after prolonged ischemia produces paradoxical ischemia-reperfusion injury, attenuating the efficacy of reperfusion therapies. This has provided impetus for identifying chronic therapies to protect against ischemia-reperfusion injury in those at risk. We previously found that regular dipyridamole therapy produces a chronic preconditioning-like effect mediated through adenosine A1 receptors.
METHODS: To determine how long this chronic preconditioning effect of dipyridamole remains present after discontinuing therapy, guinea pigs received 4 mg/kg/day in their water for 6 weeks. Ischemia-reperfusion was performed at 0, 2, 3, and 4 days after dipyridamole discontinuation (0 day, 2 days, 3 days and 4 days; n=8 per group). Left ventricular developed pressure (LVDP), end-diastolic pressure (LVEDP), coronary flow (CF), infarct size, and western blot analyses for Akt and endothelial nitric oxide synthase (eNOS) were studied.
RESULTS: After ischemia-reperfusion, 0 day, 2 days and 3 days, but not 4 days, had significantly higher LVDP and lower LVEDP compared to control. Myocardial infarct size was significantly reduced at 0 day, 2 days and 3 days, but not 4 days, compared to control. Western blot analyses demonstrated upregulation of phospho-Akt and phospho-eNOS expression at 0 day, 2 days, and 3 days, but not 4 days.
CONCLUSIONS: A chronic preconditioning-like cardioprotection by regular dipyridamole treatment persists for 3 days after discontinuing therapy. Increased activated Akt and eNOS expression may play a role in this persistent cardioprotection
Synchro: Block-generation Protocol to Synchronously Process Cross-shard Transactions in State Sharding
Traditional blockchains cannot achieve the same transaction throughput as
Web2, so their use cases are limited. Therefore, state sharding has been
proposed to improve transaction throughput by dividing the blockchain network
and managing states and transactions in parallel. However, Nightshade in the
NEAR Protocol, a type of state sharding, provides a rollback protocol to cancel
the generation of blocks containing inconsistent transaction results because
processing cross-shard transactions (CSTXs) in a 2-phase commit may cause state
inconsistency. We present a new attack that interferes with the generation of
new blocks by repeatedly executing CSTXs that certainly causes state
inconsistency, causing continuous rollback. We also propose a block-generation
protocol called Synchro to incorporate all the state changes of each CSTX into
the same block by coordinating the block prior to approving transactions in
each shard. Synchro eliminates the occurrence of the state inconsistency caused
by the CSTXs and the necessity of the rollback protocol. We use zero-knowledge
proof to make Synchro scalable in the global validation phase. Although the
actual overhead of the zero-knowledge proof has not yet been evaluated, we show
that Synchro could achieve the same transaction throughput as Nightshade
theoretically, depending on the future innovations in zero-knowledge proof
techniques
Two Kampo Medicines, Jidabokuippo and Hachimijiogan Alleviate Sprains, Bruises and Arthritis
In traditional Chinese medicine theory (TCM), the affected parts of sprains, bruises and arthritis are considered to be under certain conditions of TCM concept. We administered two Kampo medicines with synergistic effects to promote quick recovery from these conditions. Jidabokuippo (Zhidapuyifang in Chinese), which means ‘decoction for contusions’ is expected to remove these conditions. Hachimijiogan (Baweidihuangwan in Chinese), which translates as ‘eight-ingredient pill with Rehmannia’ is expected to restore presumed minute bone injury and regulates bone metabolism by changing such conditions based on TCM theory. We administered the two prescriptions to 10 patients (age range: 40–85 years; 1 male, 9 females) suffering from bruises, sprains, arthritis and spinal compression fracture without changing their routine intake of other drugs. Patients reported on changes in the pain of affected body parts by using the visual analog scale (VAS) before and after administration of Kampo medicine. In almost all cases, recovery began promptly after administration and the pain disappeared within ∼2 weeks. Large doses for a short time brought about much quicker recovery than small doses. Administration of a combination of two Kampo medicines, Jidabokuippo and Hachimijiogan, quickly resolved the pain of bruises, sprains, arthritis and one spinal compression fracture
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