A comment on the evaluation of equilibrium constants for alpha-tocopherol interactions with fatty acids by absorbance in the ultraviolet region.

This paper comments on the evaluation of Erin and co-workers (Biochim. Biophys. Acta 774 (1984) 96-102) of equilibrium constants for alpha-tocopherol interactions with fatty acids on the basis of the changes of absorbance in a 200 nm ultraviolet region. It is concluded that the ultraviolet method is inadequate because it is affected by absorption in that region of the solvent, ethanol and fatty acids which they used.

Enantioselective binding sites on bovine serum albumin to dansyl amino acids.

The enantioselective binding sites on bovine serum albumin were examined by HPLC using 19 racemic 5-N, N-dimethylamino-1-naphthalenesulfonyl derivatives of alpha-amino acids (dansyl amino acids) as chiral probes. On a bovine serum albumin bonded chiral stationary phase, seven L-forms eluted faster than their D-forms, while ten D-forms eluted before their L-forms. It was speculated that either two classes or two different binding sites exist on bovine serum albumin which can be distinguished by N-dansyl-L-proline and N-dansyl-D-norvaline. This was confirmed by fluorometric experiments where non-fluorescent 1-naphthalenesulfonyl derivatives were synthesized and competitive adsorption experiments were performed.

[Enzymatic conversion of tegafur in human tumor tissue].

Enzymatic conversion of tegafur was studied using a thymidine phosphorylase preparation purified from human liver cancer. Tegafur dissolved in water slowly decomposed to 5-FU upon storage at 37 degrees C and this conversion was further activated with an addition of a thymidine phosphorylase preparation. Analysis of Tegafur and 5-FU was performed on a high performance liquid chromatograph. The Km value was in agreement with Michaelis-Menten Kinetics and 2.44 X 10(-2) M without thymidine phosphorylase preparation. When the preparation was added, it was 2.53 X 10(-4) M and 1.75 X 10(-3) M, respectively. Determination of 5-FU concentrations in blood, normal and tumor tissues following a long term administration of Tegafur was performed. The highest concentration of 5-FU was detected in tumor tissue followed by normal tissue and blood, suggesting a human liver thymidine phosphorylase was capable of converting Tegafur to 5-FU more actively in tumor tissue than in normal tissue.

Entry point to the Sylvian fissure for the pterional transsylvian approach.

BACKGROUND: Although the anatomy of the Sylvian fissure is understood, there is little information on where to start its dissection in the pterional transsylvian (PT-TS) approach. At small craniotomy using the PT-TS approach, we set the entry point to the Sylvian fissure at 15 mm behind the anterior edge of the craniotomy along the Sylvian fissure and designated this site "point 15." Here we compared the utility of "point 15" with the Sylvian point (point on the Sylvian fissure giving rise to the horizontal and anterior ascending rami) that had been recommended earlier as the entry site for opening the Sylvian fissure. MATERIALS AND METHODS: This study includes 16 patients with 7 ruptured and 9 unruptured anterior circulation aneurysms. We evaluated the usefulness of "point 15" in the PT-TS approach for aneurysmal neck clipping with respect to the adequacy of anatomical exposure and low invasiveness. RESULTS: In 12 patients "point 15" provided for excellent anatomical exposure of the Sylvian fissure; complete neck clipping was possible with minimal brain retraction and damage. In two patients with ruptured aneurysms and thick subarachnoid hemorrhage and in two patients with unruptured aneurysms, the dissection had to be enlarged 3 to 4 mm distally without reaching the Sylvian point. In the latter two patients the Sylvian veins were tethered to frontal and temporal lobes. CONCLUSIONS: The "point 15" was an easily set entry point to the Sylvian fissure. It provided for sufficient anatomical exposure at surgery for anterior circulation aneurysms; additional posterior dissection was required in rare cases. We found that "point 15" was useful in small craniotomies using the PT-TS approach.

Low distribution of synaptic vesicle protein 2A and synaptotagimin-1 in the cerebral cortex and hippocampus of spontaneously epileptic rats exhibiting both tonic convulsion and absence seizure.

The spontaneously epileptic rat (SER) is a double mutant (zi/zi, tm/tm) which begins to exhibit tonic convulsions and absence seizures after 6 weeks of age, and repetitive tonic seizures over time induce sclerosis-like changes in SER hippocampus with high brain-derived neurotrophic factor (BDNF) expression. Levetiracetam, which binds to synaptic vesicle protein 2A (SV2A), inhibited both tonic convulsions and absence seizures in SERs. We studied SER brains histologically and immunohistochemically after verification by electroencephalography (EEG), as SERs exhibit seizure-related alterations in the cerebral cortex and hippocampus. SERs did not show interictal abnormal spikes and slow waves typical of focal epilepsy or symptomatic generalized epilepsy. The difference in neuronal density of the cerebral cortex was insignificant between SER and Wistar rats, and apoptotic neurons did not appear in SERs. BDNF distributions portrayed higher values in the entorhinal and piriform cortices which would relate with hippocampal sclerosis-like changes. Similar synaptophysin expression in the cerebral cortex and hippocampus was found in both animals. Low and diffuse SV2A distribution portrayed in the cerebral cortex and hippocampus of SERs was significantly less than that of all cerebral lobes and inner molecular layer (IML) of the dentate gyrus (DG) of Wistar rats. The extent of low SV2A expression/distribution in SERs was particularly remarkable in the frontal (51% of control) and entorhinal cortices (47%). Lower synaptotagmin-1 expression (vs Wistar rats) was located in the frontal (31%), piriform (13%) and entorhinal (39%) cortices, and IML of the DG (38%) in SER. Focal low distribution of synaptotagmin-1 accompanying low SV2A expression may contribute to epileptogenesis and seizure propagation in SER.

[On the leptospirosis occurred in a worker under construction of World Ocean Exposition in Okinawa Prefecture (author's transl)].

A male worker, 29 years old, was engaged in construction work of World Ocean Exposition in Okinawa Perfecture, and was diagnosed as suffering from leptospirosis in September 1973. The leptospirosis was an acute infection caused by Leptospira hebdomadis. The parasite seemed to be transmitted to him by ingestion of food and drink contaminated with the urine and excreta of the reservoir animals in the unsanitary workshop and living environment in Okinawa district. This leptospirosis was determined as an occupational disease.

Late-phase enhancement of the upstream portion of pancreatic adenocarcinoma on dual-phase helical CT.

BACKGROUND: Late-phase enhancement of pancreatic parenchyma upstream (tail side) of pancreatic adenocarcinoma is found frequently on dual-phase helical computed tomography (CT). We measured the frequency of late-phase enhancement of the upstream portion of pancreatic adenocarcinoma and normal pancreatic parenchyma using dual-phase helical CT. METHODS: Twenty-one patients with pancreatic adenocarcinoma and nontumorous pancreas upstream of tumors were compared with 100 control patients without pancreatic disease. Early and late scans started at 25 and 75 s, respectively, after intravenous injection of contrast material. The attenuation values of normal and nontumorous pancreas upstream of tumors were assessed in three phases: precontrast, early, and late enhanced. Enhancement ratio (ER) was calculated as ER = (late phase - precontrast)/(early phase - precontrast). RESULTS: Late-phase enhancements (ER > 1.0) were seen in 86% of upstream pancreas and 10% of normal pancreas. The mean ER of upstream pancreas was significantly higher than that of normal pancreas (p < 0.01). CONCLUSION: Late-phase enhancement of the pancreas upstream of the tumor is frequently observed in patients with pancreatic adenocarcinoma. Late-phase enhancement and histology showed a correlation for chronic obstructing pancreatitis in five patients.

A chemical model of catechol-O-methyltransferase. Methylation of 3,4-dihydroxybenzaldehyde in aqueous solution.

The reaction of 3,4-dihydroxybenzaldehyde (LH2) and dimethylsulfate (DMS) to form the m- and p-O-methylated products (vanillin and isovanillin, respectively) in aqueous 2-(N-morpholino)ethane sulfonate buffer was studied kinetically. The products were determined by means of high-performance liquid chromatography. The O-methylation occurred principally at the p-hydroxyl group in the absence of divalent metal ions. In the presence of Cu(II), the m-methylation was promoted and became predominant. Zn(II) showed a similar but less pronounced effect. The effects were explained in terms of the complex formation of LH2. The second order rate constants for the m- and p-methylation of the species, LH2, CuL and CuL2-2 by DMS were calculated. The values and their ratio for the m-/p-reactions increased in the order of LH2 less than CuL less than CuL2-2. The reaction may serve as a chemical model for catechol-O-methyltransferase, which requires divalent metals and catalyzes the m-methylation.

CT-guided treatment of ultrasonically invisible hepatocellular carcinoma.

New techniques of CT-guided management were introduced to ablate ultrasonically invisible hepatocellular carcinomas. In six patients with HCC, a total of six nodules (8-30 mm in diameter) were treated under the guidance of CT. These lesions were not visualized by sonography but were visualized as Lipiodol spots on CT after chemoembolization. Tumor localization was successful in all patients without difficulty, using a thin needle or hookwire under the guidance of CT. Two patients underwent subsequent hepatic resection and/or microwave coagulation therapy (MCT) through a small incision after hookwire placement. Four patients received percutaneous MCT (n = 2) or ethanol injection (PEI) (n = 2) at the time of localization. The postoperative CT with contrast enhancement indicated that tumor ablation was complete in four of the five nodules treated with MCT or PEI. However, in one nodule (30 mm in diameter) treated with PEI, tumor ablation was not complete. There were no complications. There has been no local tumor recurrence 6-46 months after treatment in any of the patients. In conclusion, these CT-guided procedures were effective in treating ultrasonically invisible hepatocellular carcinomas that otherwise would have remained untreated.

Chiral discrimination of N-carbazole-carbonyl derivatives of alpha-amino acids with a short linear alkyl side chain by bovine serum albumin.

Chiral discrimination of racemic carbazole carbonyl (CC)-amino acids with linear alkyl sidechain (C(1)-C(4)) by bovine serum albumin (BSA) was investigated by competitive replacement experiments using dansyl-L-proline and dansyl-D-norvaline as fluorescent probes. It was found that the CC derivatives of the D-forms of alanine (C(1)), amino butyric acid (C(2)), norvaline (C(3)), and norleucine (C(4)) bound to the dansyl-L-proline site much more strongly than their L-forms, whereas the interactions between both enantiomers of these amino acids with dansyl-D-norvaline site were slight.

[Role of CT and ultrasonography in acute blunt trauma of the abdomen].

From March 1985 to April 1989, one hundred thirty-one patients were examined using computed tomography (CT) and/or ultrasonography (US) in the evaluation of acute blunt trauma of the abdomen (CT and US in 36 patients, CT in 25 US in 70). Twenty-three out of the 131 cases (17.6%) showed positive findings of abdominal trauma on CT and/or US. Sixteen of the 23 patients with positive findings underwent therapeutic laparotomy, while all of the other 108 patients with negative findings were successfully managed conservatively. This fact suggests that one of the roles of CT and/or US is to pick up patients with negative findings who do not have any laparotomy. Free fluid collection was demonstrated in all of the 23 patients with positive findings in: all 22 on CT (100%), and 13 of 14 on US (92.9%). In all of the 23 patients but one with an injured mesenterium, injured organ was demonstrated by CT and/or US in: 21 of 22 by CT (95.5%), and 11 of 14 by US (78.6%). In one of the 11 patients, not an immediate US but a follow-up on the next day revealed an injured organ. In 6 out of the 12 patients who underwent both plain and contrast enhancement (CE), CT, CE-CT demonstrated the injured organ more clearly than plain CT. US with sector probe was also useful for demonstrating the injured lesion.(ABSTRACT TRUNCATED AT 250 WORDS)