Publications by authors named "Shuhei Niiyama"

: As COVID-19 can be severe, early predictive markers of both severity and onset of secondary bacterial infections are needed. This study first examined changes over time in the levels of plasma neopterin (NP) and biopterins (BPs), among others, in patients with COVID-19 and then in those with secondary bacterial infection complications. : Fifty-two patients with COVID-19 admitted to two tertiary care centers were included.

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Background Congenital heart disease (CHD) is a structural deformity of the heart present at birth. Pulmonary hypertension (PH) may arise from increased blood flow to the lungs, persistent pulmonary arterial pressure elevation, or the use of cardiopulmonary bypass (CPB) during surgical repair. Inhaled nitric oxide (iNO) selectively reduces high blood pressure in the pulmonary vessels without lowering systemic blood pressure, making it useful for treating children with postoperative PH due to heart disease.

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Tetrahydrobiopterin (BH4) is an essential cofactor for dopamine and serotonin synthesis in monoaminergic neurons, phenylalanine metabolism in hepatocytes, and nitric oxide synthesis in endothelial and immune cells. BH4 is consumed as a cofactor or is readily oxidized by autooxidation. Quinonoid dihydropteridine reductase (QDPR) is an enzyme that reduces quinonoid dihydrobiopterin (qBH2) back to BH4, and we have previously demonstrated the significance of QDPR in maintaining BH4 in vivo using Qdpr-KO mice.

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Background: Upon cellular injury, damage-associated molecular patterns (DAMPs) are released into the extracellular space and evoke proinflammatory and prothrombotic responses in animal models of sterile inflammation. However, in clinical settings, the dynamics of DAMP levels after trauma and links between DAMPs and trauma-associated coagulopathy remain largely undetermined.

Methods: Thirty-one patients with severe trauma, who were transferred to Kagoshima City Hospital between June 2018 and December 2019, were consecutively enrolled in this study.

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Oxidation of BH, a cofactor of nitric oxide synthase (NOS), produces reactive oxygen species (ROS) through uncoupling of NOS and affects vascular endothelial dysfunction. Ascorbic acid (AsA) inhibits the oxidation of BH and reduces ROS. However, the kinetic changes of BH in sepsis and its effect on the kinetic changes in AsA administration therapy, as well as the appropriate timing of AsA administration for AsA therapy to be effective, are unclear.

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Background: Neopterin (NP) is a biomarker for activated cellular immunity and is elevated in diseases including viral and bacterial infections, autoimmune diseases, and cancer. However, the clinical assessment of neopterin has not been used for these disorders because the physiological significance of measuring NP is obscure. It would be important to compare the NP profiles with those of other inflammation markers especially in relatively early phase of patients to reveal the significance of NP measurements in pathological states.

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Sepsis is defined as life-threatening organ dysfunction caused by dysregulated host responses to infection. Recent studies have suggested that endotheliopathy may be the common basis for multiple organ failure in sepsis. Under septic conditions, accumulation of proteases accelerates shedding of proteoglycans, such as syndecan-1, from the endothelial surface, resulting in augmented leukocyte adhesion to the vascular wall, enhanced vascular permeability, and intravascular coagulation.

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Cecal ligation and puncture (CLP) models exhibiting polymicrobial sepsis are considered as the gold standard in sepsis research. However, despite meticulous research being conducted in this field, only few treatment drugs are available, indicating that CLP sepsis models do not completely mimic human sepsis models. The greatest flaw in CLP models is abscess formation because the localization of inflammation caused by abscess formation increases the survival rate.

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An intraperitoneal giant tumor can form deep venous thrombosis (DVT), leading to pulmonary embolism (PE) when it is removed. We report a case of a giant ovarian cystic tumor with possible DVT. A 52-year-old woman (149 cm in height, 85 kg in weight, and 150 cm in ventral girth) underwent the laparoscopic resection of the cyst.

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Cerebral venous sinus thrombosis (CVST) is rare but displays various and often dramatic clinical symptoms. Few cases of CVST have been reported in the field of anesthesiology. We encountered an unexpected case of CVST that presented with delayed emergence from anesthesia after resection of a brain tumor.

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Local anesthetics block not only the Na(+) but also the K(+) and Ca(2+) channels in the mammalian neurons. It is well known that lidocaine has neuroprotective actions against the ischemic insult of neurons in the central nervous system. In order to elucidate how other local anesthetics as well as lidocaine show the neuroprotective effects against in vitro ischemic insult, intracellular recordings were made from CA1 pyramidal neurons in rat hippocampal slices.

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Neuroprotective actions of local anesthetics, bupivacaine and tetracaine, against the irreversible membrane dysfunction induced by in vitro ischemia were investigated. Intracellular recordings were made from hippocampal CA1 neurons in rat brain slice preparations. Oxygen and glucose deprivation (in vitro ischemia) produced a rapid depolarization after approximately 5 min of exposure.

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