Usefulness of cytology applied simultaneously to frozen section at rapid intraoperative diagnosis of intracranial tumors

We discussed usefulness of cytology for rapid intraoperative diagnosis of intracranial tumors using frozen section. Twenty five cases of intracranial tumors (6 cases of astrocytoma, 6 cases of glioblastoma multiforme, 4 cases of meningioma, 2 cases of pituitary adenoma, 1 case of ependymoma and 6 cases of metastatic carcinoma) were observed by cytological specimen, frozen section and formalin fixed-paraffin embedded section. When only frozen section were used for histopathological diagnosis, it was difficult to diagnose in a few case of astrocytic tumors by artifact in freezing process. When only cytological specimen were used for diagnosis, histological findings, for example pseudopalisading around necrosis in glioblastoma or rosette formation in ependymoma, were not identified. However, diagnostic accuracy were improved when both cytological and frozen specimen were used if adequate material were obtained for diagnosis. In conclusion, cytological approach used in addition to frozen section was useful for rapid intraoperative diagnosis.     

A new miniature mechanical testing procedure: Application to intermetallics

A new miniature double-shear testing procedure is introduced for the testing of semibrittle materials such as intermetallics. Detailed experiments on samples of pure Al and an Al-5 pct Mg solid solution alloy confirm that the miniature configuration provides consistent and reliable results when using either a circular or a square cross section. In addition, it is demonstrated that the data obtained using miniature specimens are consistent with results from conventional large double-shear specimens and from specimens tested under tensile conditions. The miniature testing technique is used to provide preliminary mechanical data on a Ni-45 pct Al-5 pct Fe intermetallic.     

Further purification and structural analysis of calcium spirulan from Spirulina platensis

An antiviral sulfated polysaccharide, calcium spirulan (Ca-SP), isolated from Spirulina platensis, was subjected to further purification. Ca-SP was found to be composed of rhamnose, 3-O-methylrhamnose (acofriose), 2,3-di-O-methylrhamnose, 3-O-methylxylose, uronic acids, and sulfate. The backbone of Ca-SP consisted of 1,3-linked rhamnose and 1,2-linked 3-O-methylrhamnose units with some sulfate substitution at the 4-position. The polymer was terminated at the nonreducing end by 2,3-di-O-methylrhamnose and 3-O-methylxylose residues.     

Enantioselective Total Synthesis of (+)‐Gephyrotoxin 287C

Gephyrotoxin 287C, a bioactive alkaloid bearing a perhydropyrrolo[1,2‐a]quinoline skeleton with five stereocenters, is an attractive target for synthetic organic chemistry. We achieved an enantioselective total synthesis of (+)‐gephyrotoxin 287C, for which the key steps were palladium‐catalyzed asymmetric allylic amination using a chiral diaminophosphine oxide (DIAPHOX) preligand, diastereoselective intramolecular Mannich reaction, and tin tetrachloride‐catalyzed diastereoselective conjugate addition/protonation.

     

Preparation of endohedral metallofullerene nanowhiskers and nanosheets

Endohedral metallofullerene nanowhiskers and nanosheets were prepared using pristine Sc₃N@C₈₀ by liquid-liquid interfacial precipitation. This means that it is possible to prepare endohedral metallofullerene structures without using chemical derivatization techniques. They were characterized using scanning and transmission electron microscopy and atomic force microscopy. The morphology of the prepared Sc₃N@C₈₀ structures could be tailored by merely changing the solvent used for the interfacial precipitation.     

Arc temperature measurement with microsecond spectroscopic measurement

The quality of electric power caused by frequency fluctuation and voltage rise will be degraded because of the lightning surge and the mass introduction of distributed power. Thus, it is necessary to improve the performance of gas circuit breaker in order to maintain the stable supply of electric power. It has been reported that the arc conductance is calculated as the index of the current interruption in numerical analysis. However, few report have the measured value in the current interruption. This is because that the current interruption is the steep phenomenon of micro seconds range. Thus, it is necessary to establish the time-high precision and noncontact measurement method. In this paper, the arc temperature is measured near current zero using the microsecond spectroscopic measurement. As a result, the microsecond spectroscopic measurement which combines the conventional spectroscope and the high speed video camera is 200 times faster than the measurement of conventional spectroscope. For this reason, the microsecond spectroscopic measurement is possible with the high speed video camera. Therefore, it is possible to measure the arc temperature with decreasing the current using the microsecond spectroscope.     

Synthesis and Thermal Characterization of Novel Fluorene-Based Polysiloxane Derivatives

Three novel poly(tetramethylsilfluorenylenesiloxane) derivatives having different substituent at 9-position of fluorenylene moiety, i.e. dimethyl (P1), spirocyclohexyl (P2), and spirofluorenyl (P3) substituents, were obtained by polycondensation of novel three disilanol monomers, i.e. 2,7-bis(dimethylhydroxysilyl)-9,9-dimethyl- fluorene (M1), 2’,7’-bis(dimethylhydroxysilyl)-spiro(cyclohexane-1,9’-fluorene) (M2), 2,7-bis(dimethylhydroxysilyl)-9,9’-spirobifluorene (M3), respectively. P1–P3 exhibited the good solubility in common organic solvents, such as tetrahydrofuran (THF), chloroform, dichloromethane, and toluene. It was suggested from the differential scanning calorimetry (DSC) and the X-ray diffraction analysis that P1 exhibited the crystallinity whereas P2 and P3 were amorphous polymers. The glass transition temperature (T _g) determined by DSC and the temperature at 5% weight loss (T _d5) determined by thermogravimetry (TG) were dependent on the substituent at 9-position on fluorene; both orders of T _g and T _d5 were P3 > P2 > P1, indicating the bulkiness of substituent at 9-position of fluorene resulted in the good thermal stability. It is noteworthy that amorphous P3 exhibiting very high T _g of 156 °C and T _d5 of 535 °C is a new heat-resistant polysiloxane derivative as well as a promising candidate for blue-light-emitting materials.     

Chemical Composition of the Defensive Secretion of the Longhorned Beetle, <Emphasis Type="Italic">Chloridolum loochooanum</Emphasis>

Adults of the longhorned beetle, Chloridolum loochooanum Gressitt (Coleoptera: Cerambycidae) emit a white frothy secretion from their metasternal glands. This defensive substance contains cyclopentanoid monoterpenoids (iridodials), whose structures were elucidated by gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses that compared the naturally occurring structures with synthesized versions. Optically active citronellals, [(S)-, (R)-, and (S)/(R)- mixture], were used as starting materials for synthesizing the corresponding iridodials for the determination of the absolute configuration of the natural product. The retention time of (2S)-iridodial, derived from (S)-citronellal, corresponded to that of C. loochooanum iridodial by enantioselective GC analysis. Thus, we suggest that the absolute configuration of C. loochooanum iridodial is (1R,2S,5S)-iridodial.     

Intracellular localization of the 74- and 53-kDa forms of L-histidine decarboxylase in a rat basophilic/mast cell line, RBL-2H3

To clarify the process of post-translational modification of L-histidine decarboxylase (HDC), we investigated the conversion of the 74-kDa form of HDC into the 53-kDa form in specialized organella of a rat basophilic/mast cell line (RBL-2H3). With treatment of streptolysin-O, RBL-2H3 cells released approximately 40% of HDC activity accompanied by over 90% of lactate dehydrogenase activity. Only the 74-kDa form of HDC was detected in the leaked fraction by SDS-polyacrylamide gel electrophoresis. The 74-kDa form in the homogenate of pulse-labeled cells was recovered in both the supernatant and particulate fractions, while the 53-kDa form was detected only in the particulate fraction containing marker proteins of microsomes, Golgi, and lysosomal granules. Confocal microscopic observation using double staining immunofluorescence with anti-GST fusion HDC antiserum showed that most of the HDC coexists with protein-disulfide isomerase, a typical marker of the luminal space of the ER. With treatment of digitonin, RBL-2H3 cells released only 74-kDa HDC. Trypsin digestion of digitonin-permeabilized cells resulted in the disappearance of the 74-kDa form but not the 53-kDa form. From these results, it is assumed that the 74-kDa form of HDC, synthesized in the cytosol, is translocated into the lumen of the ER, where it is converted to the 53-kDa form.     

Anesthetics modulate phospholipase C hydrolysis of monolayer phospholipids by surface pressure

N-Acetylmuramyl-L-alanine amidase (EC 3.5.1.28) cleaves the amide bond between N-acetyl muramic acid and L-alanine in the peptide side chain of different peptidoglycan products. The enzyme was purified from human plasma using a three-step column chromatography procedure. Monoclonal antibodies were produced against the purified human enzyme. By coupling of a high affinity monoclonal antibody to sepharose beads an immunoadsorbent column was prepared. Using this second purification method it was possible to purify large amounts of the amidase from human plasma in a single step. SDS-PAGE showed one single band of 70 kDa and two-dimensional electrophoresis showed the presence of multiple isomeric forms of the protein with pI between 6.5 and 7.9. Two different methods were used for determination of substrate specificity, a HPLC method separating peptidoglycan monomers from the reaction products after incubation with amidase and a colorimetric method when high molecular weight peptidoglycan was used as a substrate for amidase. It is shown that the disaccharide tetra peptide, disaccharide penta peptide and the anhydro disaccharide tetrapeptide are good substrates for the amidase and that muramyl dipeptide and disaccharide dipeptide are not a substrate for the amidase. Using one of the monoclonal antibodies against the amidase it was shown in FACScan analysis that N-acetylmuramyl-L-alanine amidase is present in granulocytes but not in monocytes from unstimulated peripheral blood of a healthy donor. The presence of N-acetylmuramyl-L-alanine amidase in granulocytes is a novel finding and perhaps important for the inactivation of biologically active peptidoglycan products still present after hydrolysis by lysozyme.