Application of residual polysaccharide-degrading enzymes in dried shiitake mushrooms as an enzyme preparation in food processing.

OBJECTIVE: To examine the activities of residual enzymes in dried shiitake mushrooms, which are a traditional foodstuff in Japanese cuisine, for possible applications in food processing. RESULTS: Polysaccharide-degrading enzymes remained intact in dried shiitake mushrooms and the activities of amylase, ß-glucosidase and pectinase were high. A potato digestion was tested using dried shiitake powder. The enzymes reacted with potato tuber specimens to solubilize sugars even under a heterogeneous solid-state condition and that their reaction modes were different at 38 and 50 °C. CONCLUSION: Dried shiitake mushrooms have a potential use in food processing as an enzyme preparation.

Biodegradation of polyvinyl alcohol by a brown-rot fungus, Fomitopsis pinicola.

A brown-rot fungus, Fomitopsis pinicola, degraded polyvinyl alcohol (PVA) in quartz sand but not in liquid culture. From gel permeation chromatography analysis, the high-molecular-weight fraction of PVA was decreased by the action of F. pinicola but the coloration of the culture filtrate with I2 solution increased. The reason for the increase in coloration was assumed to be the increase in the low-molecular-weight fraction in degraded PVA. Diffuse reflectance infrared Fourier transform spectral analysis showed that spectral changes of the fungally degraded PVA were similar to those of PVA treated with Fenton's reagent suggesting that PVA degradation by F. pinicola was via the Fenton reaction. F. pinicola can thus be used to degrade PVA in woody wastes.

Biodegradation of 2,4-dichlorophenol by shiitake mushroom (Lentinula edodes) using vanillin as an activator.

The white-rot shiitake mushroom, Lentinula edodes, was used to degrade an environmentally hazardous compound, 2,4-dichlorophenol (DCP), using vanillin as an activator. Vanillin increased the mycelial growth from 74 to 118 mg/150 ml culture and accelerated laccase and Mn-peroxidase production from the maximum on days 24-28 without vanillin to days 10-14. It eliminated 92% of 100 mM DCP with 50 mg vanillin/l compared with only 15% without vanillin. GC-MS revealed that a diaryl ether dimer of DCP was formed in the culture without vanillin, whereas dimer formation was diminished with vanillin addition. This indicates that vanillin enhances the degradation of DCP and disrupts the formation of the toxic dimer. Therefore, lignin-derived phenol such as vanillin can be used as natural and eco-friendly activators to control white-rot mushrooms, thereby facilitating the effective degradation of environmentally hazardous compounds.

Potentiation by ethanol of GABA-induced current and facilitation of its desensitization in cultured rat cortical neurons.

1. Patch-clamp whole cell recording was performed to elucidate whether or not ethanol, at low concentration, has an effect on the GABAA receptor in cultured rat cortical neurons as compared with flunitrazepam. 2. Bath application of ethanol (0.01%) or flunitrazepam (1 mM) potentiated the peak amplitude of GABA-induced (10 microM) current without affecting the equilibrium potential. 3. The decay time constant and time to peak of GABA-induced current were shortened in the presence of ethanol or flunitrazepam. 4. These findings indicate that a low concentration of ethanol and flunitrazepam potentiates the GABA-induced current concomitantly with acceleration of desensitization to the drug.

Potentiation of GABA-induced inhibition by 20-hydroxyecdysone, a neurosteroid, in cultured rat cortical neurons.

Effects of 20-hydroxyecdysone (20-HE), a neurosteroid, on cultured rat cortical neurons were examined using the whole cell recording technique. Under the voltage and current clamp conditions, brief application (5 sec) of 20-HE alone did not produce current changes nor any changes in the membrane potential. However, the chemical dose-dependently potentiated the GABA-induced current and hyperpolarization, which were blocked by bicuculline. These results suggest that 20-HE acts on the modulatory site of the GABAA receptor and potentiates GABAergic inhibition in rat cortical neurons.

Relatively immediate relaxant effects of cholera toxin on isolated rabbit blood vessels.

A study was made on the relatively immediate relaxant effect of cholera toxin (CTX) on the isolated ear artery, thoracic aorta and saphenous vein of the rabbit. Both preparations of CTX, containing sodium azide (NaN3) and azide-free, showed no effect on the non-precontracted artery, but CTX containing NaN3 relaxed the moderately precontracted blood vessels with methoxamine promptly, i.e., with a time course of min order. However, the immediate relaxation produced by CTX containing NaN3 was attributed mainly to NaN3. Azide-free CTX, on the other hand, at 1-10 micrograms/ml gradually produced concentration-dependent relaxation of the precontracted vessels. The relaxant effects of CTX on the vessels were slow and long-lasting, i.e., with a time course of 10 min order. The relaxation induced by CTX was not influenced by the removal of endothelium nor by pretreatment with 10 microM indomethacin, 3 microM atropine or 3 microM propranolol. Activation of protein kinase C by a phorbol ester inhibited the relaxant effect of CTX. These results indicate that CTX relaxes the blood vessels by directly acting on the smooth muscles, without mediation by known endogenous relaxing factor, such as endothelium-derived relaxing factor (EDRF = NO) or prostaglandin I2 (prostacyclin) and by muscarinic receptor or beta-adrenoceptor.

[A case of acute massive pulmonary embolism successfully treated with transvenous pulmonary embolectomy by catheter].

A 78-year-old woman, suffering from acute massive pulmonary embolism, was successfully treated with transvenous pulmonary embolectomy by catheter. This patient had been suffering from oppressive chest sensations during exercise, and diagnosed and treated as angina pectoris at a nearby clinic. She consulted our hospital complaining that her chest pains were increasing in frequency. She was admitted to our hospital on July 7, 1988, for coronary angiography (CAG), which she underwent on July 8 by the right femoral approach. After the CAG, she was ordered to rest in bed overnight, with the right inguinal region compressed. 18 hours later, the compression was removed and she was allowed to walk. Soon after she walked to the toilet, she complained of chest discomfort and fell into shock (systolic blood pressure was 60 mmHg). An ECG examination showed a right bundle branch block and an inverted T wave in lead V1-3. An echocardiography showed normal contraction of the left ventricle, but an enlargement of the right ventricle and a flattened interventricular septum. An analysis of arterial blood gas showed hypoxia (Pao2 52.5 mmHg, Paco2, 30.9 mmHg). Acute pulmonary embolism was suspected. 240,000 units of urokinase were administered intravenously, and pulmonary angiography was performed immediately. It revealed that the bilateral pulmonary arteries were almost completely obstructed. Although 720,000 units of urokinase were infused into the pulmonary artery, the obstruction did not improve. At that time, we performed a transvenous pulmonary embolectomy. We used a Judkins R 4 guiding catheter for PTCA made by USCI. The catheter was inserted into the pulmonary artery and clots were aspirated with a syringe.(ABSTRACT TRUNCATED AT 250 WORDS)