Supernumerary ring chromosomes and nuclear blebs in some low-grade malignant soft tissue tumours: atypical lipomatous tumours and dermatofibrosarcoma protuberans

We investigated the diagnostic significance of supernumerary ring chromosomes in low-grade soft-tissue neoplasms. Chromosome slides were prepared from 123 samples of soft-tissue tumours using the standard trypsin-Giemsa banding technique. Supernumerary ring chromosomes were found in 6 cases of soft tissue tumours: 5 cases of atypical lipomatous tumour (ALT) and 1 case of dermatofibrosarcoma protuberans (DFSP). By chromosome painting with fluorescence in situ hybridization (FISH), the ring chromosome in 1 ALT was painted over its entire length with the chromosome 12 probe. Nuclear blebs and micronuclei, which were observed in each case of ALT, also contained chromosome 12 material; and these structures may represent a topological distribution of ring or giant marker chromosomes in the interphase nuclei. Our findings suggest that supernumerary ring chromosomes are characteristic of some low-grade soft tissue neoplasms including ALT and DFSP.

Complete amino acid sequences of chitinase-1 and -2 from bulbs of genus Tulipa

The complete amino acid sequences of tulip bulb chitinase-1 and -2 (TBC-1 and -2) were determined. The sequences of the TBC-1 and TBC-2 were solved by analysis of peptides derived by enzymatic digestions as well as by chemical cleavages with cyanogen bromide (CNBr), o-iodosobenzoic acid, and hydroxylamine. TBC-1 and TBC-2 both consisted of 275 amino acid residues and had molecular masses of 30,825 and 30,863, respectively. They shared 247 identical residues, that is 90% identity. Comparison of their sequences with that of gladiolus bulb class IIIb chitinase-a (GBC-a) showed that 63% of the residues of both TBC-1 and TBC-2 are identical to that of GBC-a. From these results, it was seen that TBC-1 and -2 are class IIIb chitinases. The characteristic difference in specific activity between TBC-1 and -2 was also discussed on the basis of their amino acid sequences.

Efficiency of targeted gene delivery of ligand-poly-L-lysine hybrids with different crosslinks

Hybrids of a ligand protein crosslinked to a DNA binding protein have been developed as gene delivery vehicles mediated by receptors. To identify the effect of the crosslinks between the ligand and DNA binding protein on gene expression caused by an internalized hybrid-DNA complex, we prepared two kinds of transferrin-poly-L-lysine (TF-PL) hybrids: one was crosslinked by probably cleavable disulfide bonds (TF-ss-PL) and the other was linked by a probably uncleavable Schiff's base (TF-Schiff-PL). The binding affinity of the hybrids to HeLa cells was not different. However, the expression of a reporter gene (for luciferase) bound to these hybrids in HeLa cells transfected with TF-Schiff-PL was greater than that of TF-ss-PL.

Studies on relationships between chemical structure and beta-blocking potency of bopindolol and its two metabolites

The structure-activity relationships of bopindolol and its two metabolites (18-502 and 20-785) and their beta-blocking potencies in the human beta2-adrenoceptor (AR) were assessed using molecular modeling on an INDIGO2 workstation (SGI Co., Ltd.) and DISCOVER/INSIGHT II (Biosym Co., Ltd.). Through modeling, possible binding sites for these agents were hypothesized to involve the 3rd, 4th, 5th and 6th helices of the beta2-AR, and these shared a common interaction site at Asp113 in helix 3. The different chemical structure of these three agents, however, showed binding to different binding sites (amino acids). This study therefore suggests that different beta-blocking potencies of these agents may be due to different chemical structure.

Cloning and sequencing of the gene encoding Toho-2, a class A beta-lactamase preferentially inhibited by tazobactam

Escherichia coli TUM1083, which is resistant to ampicillin, carbenicillin, cephaloridine, cephalothin, piperacillin, cefuzonam, and aztreonam while being sensitive to cefoxitin, moxalactam, cefmetazole, ceftazidime, and imipenem, was isolated from the urine of a patient treated with beta-lactam antibiotics. The beta-lactamase (Toho-2) purified from the bacteria hydrolyzed beta-lactam antibiotics such as penicillin G, carbenicillin, cephaloridine, cefoxitin, cefotaxime, ceftazidime, and aztreonam and especially had increased relative hydrolysis rates for cephalothin, cephaloridine, cefotaxime, and ceftizoxime. Different from other extended-spectrum beta-lactamases, Toho-2 was inhibited 16-fold better by the beta-lactamase inhibitor tazobactam than by clavulanic acid. Resistance to beta-lactams was transferred by conjugation from E. coli TUM1083 to E. coli ML4909, and the transferred plasmid was about 54.4 kbp, belonging to the incompatibility group IncFII. The cefotaxime resistance gene for Toho-2 was subcloned from the 54.4-kbp plasmid. The sequence of the gene was determined, and the open reading frame of the gene was found to consist of 981 bases. The nucleotide sequence of the gene (DDBJ accession no. D89862) designated as bla(toho) was found to have 76.3% identity to class A beta-lactamase CTX-M-2 and 76.2% identity to Toho-1. It has 55.9% identity to SHV-1 beta-lactamase and 47.5% identity to TEM-1 beta-lactamase. Therefore, the newly isolated beta-lactamase designated as Toho-2 produced by E. coli TUM1083 is categorized as an enzyme similar to Toho-1 group beta-lactamases rather than to mutants of TEM or SHV enzymes. According to the amino acid sequence deduced from the DNA sequence, the precursor consisted of 327 amino acid residues. Comparison of Toho-2 with other beta-lactamase (non-Toho-1 group) suggests that the substitutions of threonine for Arg-244 and arginine for Asn-276 are important for the extension of the substrate specificity.

Complete amino acid sequence of chitinase-A from leaves of pokeweed (Phytolacca americana)

The complete amino acid sequence of pokeweed leaf chitinase-A was determined. First all 11 tryptic peptides from the reduced and S-carboxymethylated form of the enzyme were sequenced. Then the same form of the enzyme was cleaved with cyanogen bromide, giving three fragments. The fragments were digested with chymotrypsin or Staphylococcus aureus V8 protease. Last, the 11 tryptic peptides were put in order. Of seven cysteine residues, six were linked by disulfide bonds (between Cys25 and Cys74, Cys89 and Cys98, and Cys195 and Cys208); Cys176 was free. The enzyme consisted of 208 amino acid residues and had a molecular weight of 22,391. It consisted of only one polypeptide chain without a chitin-binding domain. The length of the chain was almost the same as that of the catalytic domains of class IL chitinases. These findings suggested that this enzyme is a new kind of class IIL chitinase, although its sequence resembles that of catalytic domains of class IL chitinases more than that of the class IIL chitinases reported so far. Discussion on the involvement of specific tryptophan residue in the active site of PLC-A is also given based on the sequence similarity with rye seed chitinase-c.

The effect of a secreted form of beta-amyloid-precursor protein on intracellular Ca2+ increase in rat cultured hippocampal neurones

1. The effects of secreted forms of beta-amyloid-precursor proteins (APP(S)s) on the intracellular Ca2+ concentration ([Ca2+]i) were investigated in rat cultured hippocampal neurones. APP695S, a secretory form of APP695, attenuated the increase in [Ca2+]i evoked by glutamate. In addition, APP695S itself evoked an increase in [Ca2+]i in 1 or 2 day-cultured hippocampal cells, but not in 7 to 13 day-cultured cells. 2. Eighty-one percent of neurones which were immunocytochemically positive for microtubule-associated protein 2 responded to APP695S with an increase in [Ca2+]i. 3. APP695S induced a transient rise in [Ca2+]i even in the absence of extracellular Ca2+ and produced an elevation in inositol-1,4,5-trisphosphate (IP3) in a concentration-dependent manner from 100 to 500 ng ml(-1). In the presence of extracellular Ca2+, APP695S caused a transient rise in [Ca2+]i followed by a sustained phase at high [Ca2+]i, suggesting Ca2+ entry from the extracellular space. 4. The [Ca2+]i elevation was mimicked by amino terminal peptides of APPs, but not by carboxy terminal peptides. 5. These results taken together suggest that APP695S induces an increase in [Ca2+]i in hippocampal neurones through an IP3-dependent mechanism that changes according to the stage of development.

Isolation and characterization of chitinase isoforms from the bulbs of four species of the genus Tulipa

Six chitinase isoforms, designated TBC-1 to TBC-6, were purified to homogenity from the bulbs of four species (Tulipa bakeri, T. tarda, T. turkestanica, and T. praestans) of the genus Tulipa by CM-cellulose column chromatography, Butyl-Toyopearl 650M hydrophobic column chromatography, gel filtration on Sephadex G-75, and Mono-S fast protein liquid chromatography (FPLC). The chitinases had molecular weights of 30,000 and isoelectric points of 5.2 to 6.1. These chitinases were found to proteins with similar amino acid compositions and N-terminal sequences. The tulip chitinases all had two half-cystine residues, one more than gladiolus bulb class IIIb chitinase, but many fewer than chitinases of plant class I (15-17 Cys residues/mol), II (5-8 Cys residues/mol), or III (6 Cys residues/mol). The N-terminal sequences of tulip chitinases were similar to the sequence of the gladiolus chitinase, but did not resemble sequence of any class of plant chitinase. The optimal pH of these chitinases toward glycolchitin was pH 5. TBC-1 hydrolyzed (GlcNAc)6 into (GlcNAc)2, (GlcNAc)3, and (GlcNAc)4, and hydrolyzed (GlcNAc)5 into (GlcNAc)2 and (GlcNAc)3.

Complete amino acid sequence of chitinase-a from bulbs of gladiolus (Gladiolus gandavensis)

The complete amino acid sequence of gladiolus bulb chitinase-a (GBC-a) was determined. First the tryptic peptides from GBC-a after it was reduced and S-carboxymethylated were sequenced and then the peptides were further studied by chemical cleavage of the enzyme. GBC-a consisted of 274 amino acid residues and had a molecular mass of 30,714 Da. Two consensus sequences essential for chitinase activity by plant class III chitinases were conserved in GBC-a, although its sequence similarity with plant class III chitinases was less than 20%. Sequence comparison of GBC-a with sequences of other proteins in a protein identification resource (PIR) showed that the GBC-a sequence was 33% similar to that of narbonin, a seed storage 2S globulin from narbon beans.

Involvement of amyloid precursor protein in functional synapse formation in cultured hippocampal neurons

Amyloid precursor protein (APP) is known to be widely expressed in neuronal cells, and enriched in the central and peripheral synaptic sites. Although it has been proposed that APP functions in synaptogenesis, no direct evidence has yet been reported. In this study we investigated the involvement of APP in functional synapse formation by monitoring spontaneous oscillations of intracellular Ca2+ concentration ([Ca2+]i) in cultured hippocampal neurons. As more and more neurons form synapses with each other during the culture period, increasing numbers of neuronal cells show synchronized spontaneous oscillations of [Ca2+]i. The number of neurons that showed synchronized spontaneous oscillations of [Ca2+]i was significantly lower when cultured in the presence of monoclonal antibody 22C11 against the N-terminal portion of APP. Moreover, incubation with excess amounts of the secretory form of APP or the N-terminal fragment of APP also inhibited the increase in number of neurons with synchronized spontaneous oscillations of [Ca2+]i. The addition of monoclonal antibody 22C11 or secretory form of APP did not, however, affect MAP-2-positive neurite outgrowth. These findings suggest that APP play a role in functional synapse formation during CNS development.

Secreted form of beta-amyloid precursor protein activates protein kinase C and phospholipase Cgamma1 in cultured embryonic rat neocortical cells

The secreted form of beta-amyloid precursor protein (sAPP) has been reported to exert various biological activities in cultured neurons. The signal transduction mechanisms underlying these physiological functions of sAPP remain unclear. We now report that treatment of neural cells with the secreted form of APP695 (sAPP695) leads to dose- and time-dependent increase in phosphorylation of the endogenous substrates with a molecular mass of 80, 57 and 43 kDa. Pretreatment of cells with protein kinase C (PKC) inhibitor H-7 reduced phosphorylation of the 80- and 43-kDa proteins in a dose-dependent manner. The effect of sAPP695 on the phosphorylation is mimicked by phorbol 12-myristate-13-acetate (PMA). Downregulation of PKC by prolonged treatment of cells with PMA abolished sAPP695-enhanced phosphorylation of the 80- and 43-kDa proteins, indicating PKC is involved in the sAPP695-enhanced phosphorylation of these proteins in the cells. We also suggest that the 80- and 43-kDa proteins phosphorylated by sAPP695-stimulation are the major PKC substrates myristoylated alanine-rich C-kinase substrate and growth-associated protein-43. Furthermore, we demonstrate that tyrosine phosphorylation of phospholipase Cgamma1 and formation of inositol 1,4,5-trisphosphate were increased by sAPP695-stimulation. These observations suggest that sAPP695 induces the activation of the signaling pathways through a stimulation of phosphoinositide-PKC cascade.

Renal primitive neuroectodermal tumor: a morphologic, cytogenetic, and molecular analysis with the establishment of two cultured cell lines

We report two patients with renal primitive neuroectodermal tumor (PNET) in whom the diagnosis was established by both a cytogenetic and a molecular analysis. Histologically, both renal tumors were composed of uniform immature round cells with a positive immunoreactivity for O13 (p30/32 MIC2). The cytogenetic analysis with in situ hybridization (chromosome painting) demonstrated reciprocal translocation t(11;22)(q24;q12) specific to PNET in the cultured cells derived from each tumor. The reverse transcriptase-polymerase chain reaction (RT-PCR) in both tumors demonstrated EWS/ FLI-1 fusion transcripts, representing the molecular equivalent of t(11;22). A Southern blot analysis also confirmed EWS gene rearrangement in both renal tumors. In addition, the authors also established two new cell lines (designated as FU-RPNT-1 and FU-RPNT-2) from renal PNETs. When transplanted into athymic mice, FU-RPNT-1 and FU-RPNT-2 reproduced and maintained the morphologic and molecular characteristics of the original tumors. In conclusion, the detection of t(11;22) and EWS/FLI-1 fusion transcripts is considered to provide a novel adjunctive method for diagnosing renal PNET. These newly established cell lines thus may be used to investigate the biologic behavior related to renal PNETs.

Purification and characterization of two chitinase isoforms from the bulbs of gladiolus (Gladiolus gandavensis)

Two chitinase isoforms, designated GBC-a and GBC-b, were purified from the bulbs of gladiolus (Gladiolus gandavensis) using CM-cellulose column chromatography followed by Butyl-Toyopearl 650 M hydrophobic column chromatography, gel filtration on Sephadex G-75, and Mono-S FPLC. GBC-a and GBC-b are weakly acidic and weakly basic proteins with molecular masses of 30 kDa, and isoelectric points of 6.0 and 7.5, respectively. GBC-a and GBC-b were found to be homologous proteins with similar amino acid compositions and N-terminal sequences. The number of half-cystine residues in GBC-a and GBC-b was only one each, which is much lower than those of plant class I (15-17 Cys residues/mol), class II (5-8 Cys residues/mol), and class III (6 Cys residues/mol) chitinases. The N-terminal sequences of GBC-a and GBC-b were completely different from those of plant three classes of chitinases. The optimal pHs of these chitinases toward glycolchitin were pH 5. GBC-a hydrolyzed (GlcNAc)5 into (GlcNAc)2, (GlcNAc)3 and (GlcNAc)4, and (GlcNAc)5 into (GlcNAc)2 and (GlcNAc)3.

A four-disulphide-bridged toxin, with high affinity towards voltage-gated K+ channels, isolated from Heterometrus spinnifer (Scorpionidae) venom

A new toxin, named HsTX1, has been identified in the venom of Heterometrus spinnifer (Scorpionidae), on the basis of its ability to block the rat Kv1.3 channels expressed in Xenopus oocytes. HsTX1 has been purified and characterized as a 34-residue peptide reticulated by four disulphide bridges. HsTX1 shares 53% and 59% sequence identity with Pandinus imperator toxin1 (Pi1) and maurotoxin, two recently isolated four-disulphide-bridged toxins, whereas it is only 32-47% identical with the other scorpion K+ channel toxins, reticulated by three disulphide bridges. The amidated and carboxylated forms of HsTX1 were synthesized chemically, and identity between the natural and the synthetic amidated peptides was proved by mass spectrometry, co-elution on C18 HPLC and blocking activity on the rat Kv1.3 channels. The disulphide bridge pattern was studied by (1) limited reduction-alkylation at acidic pH and (2) enzymic cleavage on an immobilized trypsin cartridge, both followed by mass and sequence analyses. Three of the disulphide bonds are connected as in the three-disulphide-bridged scorpion toxins, and the two extra half-cystine residues of HsTX1 are cross-linked, as in Pi1. These results, together with those of CD analysis, suggest that HsTX1 probably adopts the same general folding as all scorpion K+ channel toxins. HsTX1 is a potent inhibitor of the rat Kv1.3 channels (IC50 approx. 12 pM). HsTX1 does not compete with 125I-apamin for binding to its receptor site on rat brain synaptosomal membranes, but competes efficiently with 125I-kaliotoxin for binding to the voltage-gated K+ channels on the same preparation (IC50 approx. 1 pM).

Purification, characterization, and synthesis of three novel toxins from the Chinese scorpion Buthus martensi, which act on K+ channels

Three novel toxins belonging to the scorpion K+ channel-inhibitor family were purified to homogeneity from the venom of the Chinese scorpion Buthus martensi. They have been identified according to their molecular mass (3800-4300 Da) and their neurotoxicity in mice and characterized as 37-amino acid peptides. One of them shows 81-87% sequence identity with members of the kaliotoxin group (named BmKTX), whereas the other two, named BmTX1 and BmTX2, show 65-70% identity with toxins of the charybdotoxin group. Their chemical synthesis by the Fmoc methodology allowed us to show that BmKTX, unlike BmTX1 and BmTX2, possesses an amidated C-terminal extremity. Toxicity assays in vivo established that they are lethal neurotoxic agents in mice (LD50s of 40-95 ng per mouse). Those toxins proved to be potent inhibitors of the voltage-gated K+ channels, as they were able to compete with [125I]kaliotoxin for its binding to rat brain synaptosomes (IC50s of 0.05-1 nM) and to block the cloned voltage-gated K+ channel Kv1.3 from rat brain, expressed in Xenopus oocytes (IC50s of 0.6-1.6 nM). BmTX1 and BmTX2 were also shown to compete with [125I]charybdotoxin for its binding to the high-conductance Ca2+-activated K+ channels present on bovine aorta sarcolemmal membranes (IC50s of 0.3-0.6 nM). These new sequences show multipoint mutations when compared to the other related scorpion K+ channel toxins and should prove to be useful probes for studying the diverse family of K+ channels.

[Japanese cases of hyperostosis frontalis interna]

Although hyperostosis frontalis interna is common in the western countries, it has been rarely reported in the literature in Japan. We had a chance to observe 5 cases diagnosed as hyperostosis frontalis interna. They were found among 10,902 patients who came to our hospital from August 1, 1993 to September 30, 1995. All the patients in these five cases are females aged 67 to 85 (mean = 74.2 years). Four of the 5 cases had been treated as hypertension, 2 as diabetes mellitus, and 1 as hyperlipoidemia. Two cases were accompanied by unruptured aneurysms. The pathology of one case accompanied by chronic subdural hematoma revealed no apparent development of Haversian systems of bone. It seems that the prevalence of this disease in Japan would increase from now on due to the fact that the life style and the diet among Japanese people has been getting westernized.

5,6-Cis-penems: broad-spectrum anti-methicillin-resistant Staphylococcus aureus beta-lactam antibiotics

5,6-cis-Penem derivatives have been synthesized and evaluated as anti-MRSA antibiotics. The cis-penems 5 and 6 showed potent activities against not only MRSA but also a wide variety of bacteria including beta-lactamase-producing microorganisms. These compounds were designed to have high affinity to the penicillin-binding protein 2a of MRSA and to form stable acyl intermediates with beta-lactamases by blocking the deacylating water molecule.

Further studies on thermal denaturation of pyruvate dehydrogenase complex from Bacillus stearothermophilus

Thermally induced changes in pyruvate dehydrogenase complex (PDC) from B. stearothermophilus were examined mainly at temperatures from 60 degrees to 70 degrees C. Accompanied by inactivation of pyruvate decarboxylase, light scattering decreased, and ANS fluorescence increased. These changes including the inactivation were approximately first-order reactions, and the values of rate constants were greatly dependent on temperature. Chromatographic studies showed that any polypeptides were in associated forms and that final products were aggregates (> 230S) and an assembly (48S) smaller than PDC. The aggregates and assembly were rich in decarboxylase and lipoate acetyltransferase, respectively. It was suggested that, during the thermal denaturation, a decarboxylase was dissociated from PDC and immediately involved in aggregates.

Structure-activity relationships of penem antibiotics: crystallographic structures and implications for their antimicrobial activities

Twelve closely related crystal structures of the penem derivatives revealed a characteristic short contact of the oxygen atom in the C2 side-chains with the S1 atom. The side-chain conformations of the crystal structures showed a good correlation with the antimicrobial activity. In particular, the penems which show high antimicrobial activity have similar torsion angles for S1-C2-C1'-C2', suggesting that the disposition of the C2' atom would be important for binding to penicillin-interacting enzymes. Two conformations of the C6 hydroxyethyl group were observed in the crystal structures. Of those two, the conformation with a larger torsion angle (delta = 179.2 degrees) is deduced to be the enzyme-bound conformation in the Michaelis complex.

The amino acid sequence of mitogenic lectin-B from the roots of pokeweed (Phytolacca americana)

The complete amino acid sequence of pokeweed lectin-B (PL-B) has been analyzed by first sequencing seven lysylendopeptidase peptides derived from the reduced and S-pyridylethylated PL-B and then connecting them by analyzing the arginylendopeptidase peptides from the reduced and S-carboxymethylated PL-B. PL-B consists of 295 amino acid residues and two oligosaccharides linked to Asn96 and Asn139, and has a molecular mass of 34,493 Da. PL-B is composed of seven repetitive chitin-binding domains having 48-79% sequence homology with each other. Twelve amino acid residues including eight cysteine residues in these domains are absolutely conserved in all other chitin-binding domains of plant lectins and class I chitinases. Also, it was strongly suggested that the extremely high hemagglutinating and mitogenic activities of PL-B may be ascribed to its seven-domain structure.

Inhibition of fructose-6-phosphate,2-kinase by N-bromoacetylethanolamine phosphate in vitro and in vivo

Fructose-6-phosphate,2-kinase/fructose-2,6-bisphosphatase (Fru-6-P,2-kinase/Fru-2,6-BPase), a bifunctional enzyme, catalyzes the synthesis and degradation of a potent activator, fructose-2,6-bisphosphate (Fru-2,6-P2), of phosphofructokinase, and has been postulated to be an important enzyme in the regulation of glycolysis in mammalian tissues. The purpose of this study was to determine whether or not N-bromoacetylethanolamine phosphate (BrAcNHEtOP), a specific active site-directed inactivator of Fru-6-P,2-kinase, is useful for studies on the role of Fru-6-P,2-kinase in the regulation of glycolysis in vivo. BrAcNHEtOP inactivated purified recombinant rat testis-type Fru-6-P,2-kinase as well as Fru-6-P,2-kinase in a rat liver extract, with half maximum inactivation concentrations of 2 and 15 mM, respectively, on 30 min incubation at 30 degrees C. The increases in Fru-6-P,2-kinase activity and the Fru-2,6-P2 concentration in livers, prepared from fasted rats, induced by high glucose (50 mM) perfusion were suppressed in parallel after pre-perfusion with 1 to 10 mM BrAcNHEtOP, dose-dependently. Five hours after intraperitoneal injection of BrAcNHEtOP (50 to 150 mg/kg) into mice, the Fru-6-P,2-kinase activity and Fru-2,6-P2 concentration in livers had decreased in parallel, dose-dependently. These effects continued for 24 h and were accompanied by decreases in the fructose-1,6-bisphosphate, triose phosphates, and lactate contents, although the contents of glucose-6-phosphate and fructose-6-phosphate did not change. These results suggested that BrAcNHEtOP inactivates Fru-6-P, 2-kinase, resulting in a decrease in the Fru-2,6-P2 level, which causes inactivation of phosphofructokinase and consequently inhibition of glycolysis in liver. Furthermore, the suppressed levels of Fru-6-P,2-kinase activity and metabolites in mice livers were sustained by daily injection of BrAcNHEtOP for 4 days, and body weight gain was also suppressed during the administration of BrAcNHEtOP. These results suggested that BrAcNHEtOP will be a useful reagent for studying the role of Fru-6-P,2-kinase in vivo.

Neurotropic pyrimidine heterocyclic compounds. II. Effects of novel neurotropic pyrimidine derivatives on astrocytic morphological differentiation

Astrocytes play an important role in supporting nerve regeneration after brain injuries. In this study, the effects of novel neurotropic synthesized pyrimidine compounds on astrocytic morphological differentiation were examined. Treatment of protoplasmic cultured astrocytes with 2-piperidino-5,6-dihydro-7-methyl-6-oxo(7 H)pyrrolo[2,3-d]pyrimidine maleate (MS-430) and the related compounds caused astrocytic process formation in 60 min. The morphology of MS-430-treated cells was similar to that of dibutyryl cAMP (DBcAMP)-treated cells. The astrocytic process formation by MS-430 was observed within 60 min and the maximum effect was obtained at the drug concentration of 0.5-1.0 mM. Rhodamine-phalloidin staining showed that astrocytic cytoskeletal actin was reorganized by MS-430 and DBcAMP. MS-430 did not increase cAMP accumulation in cultured astrocytes. These results suggest that the neurotropic pyrimidines induced astrocytic morphological differentiation through a cAMP-independent mechanism.

GB virus C and hepatitis C virus infections in hemodialysis patients in eight Japanese centers

RNA of a putative non-A to E hepatitis virus, designated GB virus C (GBV-C), was detected in 40 (6.2%) of 645 hemodialysis patients, at a frequency significantly higher than in 3 (0.9%) of 336 blood donors in Japan (p < 0.001). A history of transfusion was more frequent (88 vs. 58%, p < 0.001), the duration of dialysis was longer (13.2 +/- 7.9 vs. 7.9 +/- 6.5 years, p < 0.001), and the detection of hepatitis C virus RNA was more often (38 vs. 18%, p < 0.01) in the 40 patients with GBV-C RNA than in the 605 patients without it. The prevalence of GBV-C RNA varied widely from 0 to 10% among the 8 dialysis centers. These results indicate that hemodialysis patients would be at increased risk of GBV-C transmitted by transfusions. The detection of GBV-C RNA in the 5 patients without a history of transfusion and a high prevalence restricted to certain dialysis centers would reflect nosocomial infection.

Developmental changes in functional EEG asymmetry: a multivariate autoregressive modeling approach

To investigate the functional asymmetry of the electroencephalogram (EEG) in the developing brain, we analyzed quantitatively the different components of simulated EEG (SEEG) in a model before and after cutting off the intercerebral interaction. Original EEG (OEEG) recordings were obtained from 374 normal children aged 3-12 years. The SEEGs were computed from the OEEG after applying 'ARdock', a new multivariate autoregressive (AR) modeling method. Subsequently, the univariate AR and component analysis was applied on OEEG and SEEG. The F value was computed from Mahalanobis' distance between both AR coefficients of component activities for age, EEG derivation and frequency band. Our analysis showed developmental lateralities in the alpha band at the frontal pole in 5 and 12 year old children, and at the central region in 8 and 11 year old children. Our results suggest that the intercerebral interactions develop at approximately 5 years of age at the left frontal pole during the period of maturation of alpha band activity and after 8 years of age when it replaced theta band activity. The present method of analysis may have a wide clinical application in the analysis of normal and abnormal EEGs.

Color Center Laser-Microwave Double Resonance Spectroscopy of the nu1 Vibrational State of HCCF

Rotational transitions of fluoroacetylene in the nu1 (CH stretch) vibrational state have been observed by the laser-microwave double resonance technique using a color center laser as a radiation source in the 3 &mu;m region. The rotational constant and centrifugal distortion constant in the nu1 state were determined to be 9684.310(16) MHz and 2.68(62) kHz, respectively, where the uncertainties given in parentheses correspond to 2.5 standard deviations.