Synthesis of water-soluble anthracene-appended benzoxaboroles and evaluation of their cis-1,2-diol recognition properties.

Three series of water-soluble anthracene-appended benzoxaboroles 1a-c were developed; their binding affinity toward cis-1,2-diols was explored by conventional fluorescence titrations to demonstrate the role of benzoxaborole as a general recognition motif of cis-1,2-diols for fluorescent probes. The complex structures of the tetra-coordinated boronate adducts between 1 and the cis-1,2-diols were revealed.

Analysis of xenon CT data with a personal computer.

We transferred stable xenon cerebral blood flow (CBF) data to a personal computer by a software of the digital imaging and communications in medicine (DICOM) output, and handled raw data with the NIH image software. CBF values were able to calculate with the NIH image accurately. This system made a precise color image and correct grey scale image submit to a magazine. DICOM output liberates us from a limit of time and place to analyze xenon CT data.

The regional cerebral blood flow amelioration of argatroban in the acute stage of cerebral thrombosis.

Cerebral blood flow changes by argatroban in the acute stage of cerebral thrombosis have been investigated with the use of stable xenon computed tomography (Xe/CT). The study group consisted of 14 cases (7 males, 7 females) with the average age of 59 years old (ranging from 21 to 79 years of age). We evaluated the cerebral blood flow change after an intravenous drip infusion of 10 mg of argatroban. After the administration of argatroban, we recognized a significant increase in the blood flow (24.4 +/- 5.0 ml/100 g/min to 28.4 +/- 2.7 ml/100 g/min, p < 0.05) in the blood flow area of lower than 30 ml/100 g/min in the affected vascular territory. As a conclusion, we found that argatroban improves ischemic symptoms through the amelioration of blood flow in the penumbra area.

Mutastein, a new inhibitor of adhesive-insoluble glucan synthesis by glucosyltransferases of Streptococcus mutans.

Mutastein, a new inhibitor of glucosyltransferases (GTase) of Streptococcus mutans, was isolated from cultural broth of Aspergillus terreus M3328. Mutastein was a heat-stable protein and was sensitive to pronase digestion. In the formation of glucans, that of adhesive water-insoluble glucans of S. mutans was specifically inhibited by mutastein.

[A case of cerebellar hematoma due to venous angioma presenting trigeminal dysfunction].

With regard to the natural history of venous angioma, the risk of hemorrhage is reported to be relatively higher if the lesion exists in the posterior fossa. However a recent report of 100 cases of venous angioma concluded that the risk of hemorrhage was low, being only 0.22%/year. Although the true rate of hemorrhage is uncertain, we have encountered case of cerebellar hematoma due to venous angioma in the posterior fossa where the patient presented with trigeminal dysfunction and cerebellar ataxia, without any history of hypertension. We considered that venous angioma in the posterior fossa might cause cerebellar hemorrhage. After removal of the hematoma, the patient's symptoms were resolved. In the posterior fossa, a relatively higher volume of venous blood would cause venous congestion to occur more easily, leading to damage of the fragile wall of the angioma.

Supramolecular effects and molecular discrimination by macrocyclic hosts embedded in synthetic bilayer membranes.

Hybrid assemblies were prepared in combinations of a synthetic lipid, involving an L-alanine residue interposed between an anionic head group and a hydrophobic double-chain segment, with cage-type cyclophanes having a three-dimensionally extended hydrophobic cavity. Incorporation behavior of the cage-type hosts into the multi- and single-walled vesicules was characterized by highly sensitive differential scanning calorimetry and dynamic light-scattering measurements as well as by gel-filtration chromatography and electronic absorption spectroscopy. Both hosts were found to be completely incorporated into a relatively polar domain close to the vesicular surface. Anionic guest molecules, such as naphthol yellow S, dimethylsulfonazo III, bromopyrogallol red, and orange G, were effectively incorporated into the hydrophobic cavities provided by the cage-type cyclophanes embedded in the single-walled bilayer membrane, as confirmed by circular dichroism spectroscopy; the formation constants for 1:1 host-guest complexes were in the order of 10(4)-10(5) mol.dm-3. This means that the binding affinities of the cage-type hosts are largely retained even when the hosts are incorporated into the vesicle. Moreover, the pyridinium moieties bound to the chiral L-valine residues in the bridging components of the hosts underwent conformational changes upon inclusion of the guest, as confirmed by circular dichroism spectroscopy and molecular mechanics and dynamics calculations.

Chemical and functional properties of mutastein, an inhibitor of insoluble glucan synthesis by Streptococcus sobrinus.

Mutastein, a potent inhibitor of insoluble glucan synthesis by Streptococcus sobrinus, is a protein with a molecular weight of approximately 2 x 10(6). Amino acid and ELISA analyses suggested that mutastein is a mixture of heterogenous polymers of alpha-casein contained in the culture medium of the producing strain, Aspergillus terreus M3328. Mutastein strongly inhibited the primer-dependent insoluble glucan synthase of S. sobrinus B13. The primer-independent soluble glucan synthase was not affected by mutastein while primer-dependent soluble glucan synthase was slightly activated.

Inhibition of Glucan Synthesis by Casein Polymers Crosslinked by Glutaraldehyde.

Glutaraldehyde-crosslinked α-casein polymers with molecular masses of 1-5×10(5) were found to inhibit adhesive insoluble glucan formation catalyzed by glucan synthases from Streptococcus sobrinus B13, a cariogenic oral bacterium. Of the three subcomponents of the glucan synthases tested, primer-dependent insoluble glucan synthase was inhibited specifically by the M r~2.7×10(5) polymer at a concentration of 1.4-8.5 µg/ml. The polymer was also active in inhibiting the artificial plaque formation by S. sobrinus B13.

Experimental study on thermal damage to dog normal brain.

We investigated the temperature changes and their distribution in agar phantoms and dog normal brains induced by 8 MHz radiofrequency interstitial hyperthermia and observed the histological changes, with respect to the neurons and myelinated nerve fibres, induced by the same heat source in dog normal brains. We also examined the change of blood-brain barrier permeability using Evans blue solution. The heating limits of dog normal brain were 42 degrees C for 45 min or 43 degrees C for 15 min and the breakdown of the BBB was observed at 43 degrees C for 60 min.

Malignant meningioma metastasizing through the cerebrospinal pathway.

A case of malignant meningioma metastasizing through the cerebrospinal pathway is presented. The primary tumor was a parasagittal malignant meningioma invading into the brain. The tumor seeded to the cerebellopontine angle cistern and thoracic spine after multiple operations. Although this type of tumor borders the CSF, metastasis through the cerebrospinal pathway is rare, and only 18 such cases have been reported (2, 3, 10, 12).

Glucan-binding domain of a glucosyltransferase from Streptococcus sobrinus: isolation of a 55-kilodalton peptide from a trypsin digest of glucosyltransferase prebound to insoluble glucan.

We isolated a glucan-binding domain of water-insoluble glucan synthase (GTF-I) of Streptococcus sobrinus B13. Mild trypsin digestion of GTF-I bound to a water-insoluble glucan (IG) produced one predominant large fragment (55 kilodaltons). The fragment was easily recovered in IG precipitate. The isolated fragment had the same degree of affinity to IG as did the native GTF-I but no glucan synthesis activity. By the same method, a similar 55-kilodalton fragment was protected for GTF-Sd but not for GTF-Si. Immunological comparisons using specific antisera against the purified glucan-binding fragment of GTF-I from strain B13 indicated that GTF-I and GTF-S have a distinct glucan-binding domain.