Antioxidative activity of volatile chemicals extracted from beer.

Volatile chemicals obtained from a commercial beer by liquid-liquid continuous extraction were evaluated for antioxidant activity. The inhibitory ability of this extract toward the conversion of hexanal to hexanoic acid was monitored over a 35-day period. The volatile extract demonstrated >99% effectiveness at inhibiting hexanal oxidation at 50 microg/mL, comparable to that of the natural antioxidant alpha-tocopherol (vitamin E). Volatile compounds contained in the extract were isolated and identified by gas chromatography-mass spectrometry (GC-MS). From the volatile constituents identified in beer extract, phenylethyl alcohol, maltol, and 2-furanmethanol were examined for antioxidative activities. At a concentration of 500 microg/mL, maltol and 2-furanmethanol demonstrated approximately 95 and 100% inhibition of hexanal oxidation over 35 days, respectively. Phenylethyl alcohol did not show any appreciable level of inhibition of hexanal oxidation. Heterocyclic compounds, some of which are known to possess antioxidative activities, were also identified in the volatile extract.

Fast MR imaging and ultrafast MR imaging of fetal central nervous system abnormalities.

The aims of this study were two: (1) to compare the efficacy of fast MRI (breath-hold fast spin-echo T2-weighted and fast gradient-echo T1-weighted sequence) and ultrafast MRI (half-Fourier acquisition single-shot turbo spin-echo sequence) in evaluation of fetal central nervous system (CNS) abnormalities at late gestational age, and (2) to compare the capability of fast MRI and ultrafast MRI to assess fetal CNS abnormalities with that of prenatal ultrasonography (US). Forty-nine women with fetuses at gestational ages of 26-39 weeks underwent fast MRI (29 patients) or ultrafast MRI (20 patients). In detection of motion artifact, visualization of the lateral and 4th ventricles, and differentiation between gray and white matter in cerebral hemispheres, ultrafast MRI was significantly superior to fast MRI (p< 0.0001, Mann-Whitney U test). In 25 of 43 cases, US and MR diagnoses were the same and consistent with postnatal diagnosis. In 10 of 43 cases, MRI demonstrated findings additional to or different from those of US, and MR findings were confirmed postnatally. MRI, particularly ultrafast MRI, is useful for demonstrating CNS abnormalities in situations in which US is suggestive but not definitive.

Biochemical differences between human malignant and benign insulinoma tissues.

Five cases of malignant insulinoma and 2 cases of benign insulinoma were studied lipid-chemically. Tissues were collected by surgical operation or biopsy under peritoneoscopy. The total lipid was extracted from each tissue, and one part of each total lipid was separated into phospholipid, triglyceride and other lipid fractions by a thin-layer chromatography (TLC) on silica gel. The fatty acid composition and fatty acid content of each lipid fraction were measured by a gas-liquid chromatography (GLC). The most remarkable difference between malignant and benign isulinoma tissues was a higher percentage value of eicosatrienoic acid in the phospholipid of malignant insulinoma tissues when compared with that of non-malignant insulinoma tissues; the values mentioned above distributed between 9.82 and 3.32 in 5 malignant cases, but were 2.89 and 2.57 in 2 benign cases. Those changes in the phospholipid fatty acid composition of malignant insulinoma tissues may represent one of the mechanisms of malignant growth in the malignant neoplastic tissue.

[Fibrinolytic activity of cerebrospinal fluid in subarachnoid hemorrhage (author's transl)].

This study was aimed to investigate the correlation between recurrent hemorrhage of ruptured intracranial aneurysm and local fibrinolytic activity of aneurysmal fibrin plug. The fibrinolytic activity of cerebrospinal fluid (CSF) was investigated in 63 patients with various neurological diseases by means of modified fibrin plate method. No plasmin was elicited in normal CSF, however, it was confirmed that CSF contained an incomplete activator which became a complete activator inthe presence of streptokinase, and plasminogen was identified in the presence of urokinase. In 26 cases of subarachnoid hemorrhage, the fibrinolytic activity of CSF occurred in the patients within two weeks following hemorrhagic ictus. In almost cases, the fibrinolytic activity of CSF was not increased in the first three weeks after the onset of hemorrhage. This result agreed with the fact that rebleeding of intracranial aneurysm tended to occur within two weeks after the hemorrhage. Therefore, intensive antifibrinolytic therapy for two weeks after onset of hemorrhage is necessary in order to prevent recurrent hemorrhage of intracranial aneurysm, and its doses should be sufficient to inhibit local fibinolysis. It has been suggested that the local fibrinolysis after subarachnoid hemorrhage would be caused by activators released from damaged surrounding brain tissues. Furthermore, it is strongly suggested from the result of our in vitro experiments that coexistence of CSF and blood play an important role to increase local fibrinolysis.