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The heterogeneity of BPA distribution in the tumor tissues suggests the possibility of tumor recurrence for patients because the area with a lower penetration of BPA might receive an insufficient dose for killing tumor cells in BNCT. In addition, the BPA biodistribution image obtained in the present study showed that BPA accumulates evenly in the deep part of the brain tumor, rather than a biased BPA biodistribution due to diffusion from CSF. In our study, we examined the BPA biodistribution in rat brain after BPA infusion via CSF circulation to demonstrate the usefulness of the CSF administration method for brain tumors. We obtained evidence that BPA arrives directly into the brain parenchyma with CSF microcirculation through perivascular spaces by creating images of BPA penetration into the brain parenchyma following administration via CSF. [Extracted from the article]

We studied 27 cases that were post or prenatally diagnosed with body stalk anomaly (BSA) using medical records of prenatal ultrasound findings, pregnancy outcomes, and fetal/neonatal prognosis during 1992 to 2018. Termination of pregnancy was chosen in 15 cases. Of the remaining 12 cases, seven were stillbirths and five were live births. Of seven stillbirths, intrauterine fetal demise occurred before onset of labor in four cases at 17 to 20th weeks of pregnancy. Pregnancy was continued in eight cases. Median gestational age of delivery was 33rd weeks of pregnancy. Median birth weight was 1198 g (range:482‐1914 g). Vaginal delivery was chosen in six and caesarean delivery in two cases. Among six vaginally delivered cases, three (50%) fetuses were stillborn. All five live born neonates died within a few hours (16‐133 minutes). Eighteen cases were confirmed as BSA postnatally by placental examination or autopsy at our hospital. Main prenatal ultrasonographic findings of them were abdominal wall defect (100%), absence of the umbilical cord (72%), abnormal spine (61%), and abnormal legs (50%). The most characteristic prenatal ultrasonography findings of BSA were the absence of free umbilical cord in the amniotic cavity and the presence of abdominal organs into the extraembryonic celom through abdominal wall defects. The autopsy showed severe pulmonary hypoplasia with the median lung/body weight ratio of 0.61% (range:0.34‐0.85%). There were no cases of maternal morbidities. Our study provides important information about the pregnancy outcome and the fetal/neonatal outcome of BSA cases for the parents whose fetuses are diagnosed with BSA prenatally. [ABSTRACT FROM AUTHOR]

A novel ionization technique named medium vacuum chemical ionization (MVCI) mass spectrometry (MS), which is a chemical ionization using oxonium (H 3 O + ) and hydroxide (OH - ) formed from water, has excellent compatibility with the supercritical fluid extraction (SFE)/supercritical fluid chromatography (SFC). We have studied a method to determine free fatty acids (FFAs) in a small section of bovine liver tissue using SFE/SFC-MVCI MS analysis without further sample preparation. A series of FFA molecules interact with the C18 stationary phase, exhibiting broad chromatographic peaks when using a non-modified CO 2 as the mobile phase. It can be optimized by adding a small content of methanol to the mobile phase as a modifier; however, it may dampen the ionization efficiency of MVCI since the proton affinity of methanol is slightly higher than water. We have carefully evaluated the modifier content on the ion detection and column efficiencies. The obtained result showed that an optimized performance was in the range of 1 to 2% methanol-modified CO 2 mobile phase for both column efficiency and peak intensity. Higher methanol content than 2% degrades both peak intensity and column efficiency. Using optimized SFC conditions, a section of bovine liver tissue sliced for 14 µm thickness by 1 mm square, which is roughly estimated as about 3300 hepatocytes, was applied to determine 18 FFAs amounts for carbon chains of C12-C24. An amount of each tested FFA was estimated as in the range of 0.07 to 2.6 fmol per cell., (Copyright ©2024 Toshinobu Hondo, Yumi Miyake, and Michisato Toyoda.)

A method for the rapid determination of α -tocopherol ( α -T) and its oxidative products in plant tissue has been developed using supercritical fluid extraction (SFE) coupled with supercritical fluid chromatography (SFC) and medium vacuum chemical ionization (MVCI) with tandem mass spectrometry. The method is designed to study changes in levels for α -T and its oxidative products in plant cells during photosynthesis, aiming to observe the light response curves. α -T oxidation is a non-enzymatic self-defense mechanism in plant cells. Unlike enzyme-involved reactions, it cannot be stopped, so the oxidation continues in crude extracts even after extraction. Therefore, a real-time in-situ method is essential for tracking the light response curves. To optimize the selective reaction monitoring method, the reaction mixture of α -T and singlet oxygen ( 1 O 2 ), generated by rose Bengal under light illumination, was used as the source of oxidative products. The relative abundance changes in α -tocopherylquinone and 8a-hydroperoxy tocopherone in Pisum sativum L. (Pea) leaves under excessive light illumination have been preliminarily analyzed as part of the light response curve study. The method archives a throughput of 10-15 minutes for analyzing duplicate leaf samples. This process includes cutting off the leaf, sectioning it, placing the sample in a frozen SFE vessel, and conducting SFE/SFC analysis. Consequently, the average throughput is approximately 5-7 minutes per sample., (Copyright © 2024 Toshinobu Hondo, Yumi Miyake, and Michisato Toyoda.)

We have developed a rapid and sensitive analytical method for α-tocopherol and its oxidative products by combining online hyphenation of supercritical fluid extraction-supercritical fluid chromatography (SFC) with proton transfer reaction (PTR) ionization mass spectrometry (MS). α-Tocopherol is a well-known antioxidant that plays a vital role in the antioxidant defense system in plant cells. However, studies on the cellular mechanisms of α-tocopherol have been limited owing to the lack of a rapid analytical method, which limits the comparison of plant cells incubated in various conditions. Additionally, complex sample preparation and long chromatography separation times are required. Moreover, the majority of the involved molecules are a combination of isomers, which must be separated before applying tandem MS. α-Tocopherol produces the α-tocopheroxyl radical in the first step of its antioxidant function; another ion with the same mass may also be generated from the source. SFC separation effectively distinguished the observed ions from their oxidative products in the sample and those produced during the ionization reaction process. This method enabled the measurement of α-tocopherol and its oxidative products such as α-tocopheroxyl radical and α-tocopheryl quinone in approximately 3 min per sample, including the time required for sample preparation., (Copyright © 2022 Chihiro Ota, Toshinobu Hondo, Yumi Miyake, Hiroshi Furutani, and Michisato Toyoda.)

Proton-transfer-reaction (PTR) mass spectrometry (MS) is capable of detecting trace-level volatile organic compounds (VOCs) in gaseous samples in real time. Therefore, PTR-MS has become a popular method in many different study areas. Most of the currently reported PTR-MS applications are designed to determine volatile compounds. However, the method might be applicable for nonvolatile organic compound detection. Supercritical fluid chromatography (SFC) has been studied in the last 5 decades. This approach has high separation efficiency and predictable retention behavior, making separation optimization easy. Atmospheric ionization techniques, such as atmospheric chemical ionization (APCI) and electrospray ionization (ESI), are the most studied SFC-MS interfaces. These processes require the addition of makeup solvents to prevent precipitation or crystallization of the solute while depressurizing the mobile phase. In contrast, the PTR process is carried out in a vacuum; supercritical carbon dioxide may release solute into the PTR flow tube without a phase transition as long as it is maintained above a critical temperature. Therefore, this might constitute yet another use for the SFC-MS interface. Caffeine and a few other nonpolar compounds in supercritical carbon dioxide were successfully detected with time-of-flight MS without adding solvent by using preliminarily assembled supercritical flow injection and supercritical fluid extraction (SFE)-PTR interfaces.

Simultaneous ion counting and waveform averaging implemented on a field-programmable gate array compiled with a high-speed digitizer was applied to ultraperformance liquid chromatography-time-of-flight mass spectrometric analysis of sulfa drugs. Ion counting was carried out by a "Peak Detection" (PKD) function that works together with signal averaging (AVG). Sulfadimidine (SDD) and sulfadimethoxine (SDMX) were measured in human serum (HS) model sample matrix. By using simultaneous PKD and AVG acquisition, we observed a unified calibration curve for more than 3 orders of magnitude of sample amounts (0.010-100.0 pmol). The ion count rate for the "practical" sample amounts, such as less than 1 pmol, was below 30%, which is suitable for PKD-based ion counting for quantitative accuracy and excellent peak identification performance. Samples containing 200 fmol or less could not be identified from the AVG waveform. Adding HS treated with acetonitrile severely suppressed the SDMX ion to less than one-half (58.1%). However, a linear response was observed for chromatographic peak area for analytes calculated from PKD waveforms. Also, the mass-resolving power calculated from the peak on the PKD waveform was 24% better than the corresponding AVG waveform, which also improves performance for analyte identification.

Objective: Crush syndrome (CS) is a serious medical condition characterized by muscle cell damage resulting from pressure. CS has a high mortality, even when patients receive fluid therapy. We examined whether administration of NaNO2-containing fluid can improve survival in a rat model of CS., Design: The CS model was generated by subjecting anesthetized rats to bilateral hind limb compression with a rubber tourniquet for 5 h. Rats were then randomly divided into six groups: sham; CS with no treatment; CS with normal saline treatment; CS with normal saline + 25 mEq/L bicarbonate treatment; and CS with normal saline + 200 or 500 μmol/kg NaNO2., Measurements and Main Results: Blood and tissue samples were collected for histological and biochemical analyses at predetermined time points before and after reperfusion. Ischemic compression of rat hind limbs reduced nitrite content in the crushed muscle, and subsequent reperfusion resulted in reactive oxygen species-induced circulatory dysfunction and systemic inflammation. Rats treated with 200 μmol/kg NaNO2 showed increased nitric oxide (NO) levels, blood circulation, and neoangiogenesis, decreased generation of reactive oxygen species, and suppression of the inflammatory response, leading to complete recovery., Conclusions: Treatment with 200 μmol/kg NaNO2 prevents muscle damage induced by ischemia reperfusion via the protective effects of NO and suppression of systemic inflammation, thereby increasing survival rates in CS.