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A new method for preparing neutron monitors has been developed by using an ink-jet printer. A solution including gold, which is a monitor element for neutrons, is sprayed out uniformly onto a paper sheet in this method. Uniformity of the prepared monitor was found to be within a range of a few percent. The preparation procedure is simple and uses commercially available equipment without need for special modifications. Neutron distribution can be measured using a neutron monitor prepared by the method reported here.

N116Y, H-RAS mutant, has dominant negative activity in the RAS function and a suppressive effect on the growth of various types of cancer cells. However, a replication error of N116Y is of potential concern for carcinogenesis in clinical application. To decease the concern, we constructed modified N116Y by deleting the carboxyl terminus, which is necessary for the oncogenic function of Ras. One of the C-terminal deletion mutants of N116Y, N116Y-Cdel2 showed a growth-suppressing effect on various human cancer cell lines in vitro: the cervical cancer cell line HeLa, the pancreatic cancer cell line PCI43, the colon cancer cell lines SW480 and LoVo, and the tongue cancer cell line SAS. In addition, the suppressive effect of N116Y-Cdel2 on LoVo cells was also observed in vivo using a non-viral gene transfer vector, HVJ envelope. Our experiments suggest that the modified N116Y is a potential candidate gene for human cancer gene therapy.

The clinical applicability of dynamic single photon emission tomograpy (SPET) using a dual-head gamma camera equipped with a slip-ring rotational mechanism, referred to as serial SPET, was examined in the present investigation. Serial SPET enables the production of tomographic images for any arbitrary time frame from an arbitrary range of data to 360°. In a pre-clinical evaluation, a correlation between radioactivity concentration and serial SPET counts was evaluated in a phantom with continuous changes in 99mTc concentration. A differential value was obtained from each pair of SPET images; moreover, moving average approximation processing was investigated with respect to the elimination of noise in the data. In 11 and one patient presenting with cerebrovascular disease and meningioma, respectively, changes in SPET counts were evaluated when 99mTc ethyl cysteinate dimer (99mTc-ECD) was continuously administered at a constant rate in the resting state. Furthermore, in six of 11 subjects with cerebrovascular disease, changes occurring in SPET counts were examined by using acetazolamide loading while continuously administering 99mTc-ECD at a constant rate. Consequently, serial SPET enabled the evaluation of changes in radioactivity concentration over time in both the phantom and preliminary clinical studies. Data analysis by differential processing utilizing moving average approximation processing enabled the detection of minor changes in radioactivity concentration. An increase of 15.1±5.4 was observed in SPET counts of the unaffected cerebral hemisphere with acetazolamide loading. The response of the affected hemisphere was less prominent. These findings suggest that serial SPET would be an effective technique for the pharmacokinetic analysis of radiopharmaceuticals in vivo.

Apoptotic cell death, characterized by chromatin condensation, nuclear fragmentation, cell membrane blebbing, and apoptotic body formation, is also accompanied by typical mitochondrial changes. The latter includes enhanced membrane permeability, fall in mitochondrial membrane potential (Deltapsi(m)) and release of cytochrome c into the cytosol. Gelsolin, an actin regulatory protein, has been shown to inhibit apoptosis, but when cleaved by caspase-3, a fragment that is implicated as an effector of apoptosis is generated. The mechanism by which the full-length form of gelsolin inhibits apoptosis is unclear. Here we show that the overexpression of gelsolin inhibits the loss of Deltapsi(m) and cytochrome c release from mitochondria resulting in the lack of activation of caspase-3, -8, and -9 in Jurkat cells treated with staurosporine, thapsigargin, and protoporphyrin IX. These effects were corroborated in vitro using recombinant gelsolin protein on isolated rat mitochondria stimulated with Ca(2+), atractyloside, or Bax. This protective function of gelsolin, which was not due to simple Ca(2+) sequestration, was inhibited by polyphosphoinositide binding. In addition we confirmed that gelsolin, besides its localization in the cytosol, is also present in the mitochondrial fraction of cells. Gelsolin thus acts on an early step in the apoptotic signaling at the level of mitochondria.

Rat colonic mucosa contains ETA and ETB receptors with Kd values for endothelin (ET)-1 of 32 and 11 pM and maximal binding capacities of 277 and 181 fmol/mg protein, respectively. In muscle-stripped rat colon without tonic nerve activity in Ussing chambers, the serosal addition of ET-1, ET-3 and IRL1620 inhibited amiloride-sensitive noncoupled Na+ entry and enhanced diphenylamine-2-carboxylate-sensitive Cl- secretion, producing a sustained decrease and a transient increase in the short-circuit current (Isc) and the transepithelial conductance, respectively. EC50 values of ET-1, ET-3 and IRL1620 and the maximal changes in Isc were 2.0, 10.2 and 10.9 nM and -12.7, -7.0 and -7.1 muA/cm2, respectively for the Na+ entry; these values were 50, 220 and 225 nM and +57.3, +47.3 and +21.3 muA/cm2, respectively, for the Cl- secretion. FR139317 (100 nM) inhibited ET-1-induced Na+ and Cl- movements, shifting the concentration-response curves to the right (EC50 = 25 nM and 1 microM, respectively), and inhibited ET-3 (> 100 nM)-induced Cl- movement, decreasing the maximal response to 35%, but it did not inhibit either ET-3-induced Na+ movement nor IRL1620-induced Na+ and Cl- movements. The removal of serosal Ca++ reduced 100 nM ET-1- and IRL1620-evoked changes in Isc by 50% and 70% for the Na+ entry and by 80% and 100% for the Cl- secretion, respectively. Indomethacin (1 microM) also reduced changes in Isc by 30% and 70% for the Cl- secretion but did not affect the Na+ entry. Our results show that ETA and ETB receptors regulate Na+ and Cl- transport by different mechanisms.

A new Hepatitis B virus (HBV) DNA integrant clone DA2-6, isolated from a human hepatocellular carcinoma (HCC) genomic library, was tested for its ability to transactivate expression of other genes. DA2-6 consists of 3.7 kb flanking cellular sequences and an integrated 2.8 kb HBV DNA which covers the region of preS, S, and the 3′ truncated X. Using a chloramphenicol acetyltransferase (CAT) assay, a number of cellular and viral promoters were transactivated by DA2-6,and the spectrum of transactivational effect was the same as that by the wild type X gene of the virus. Deletion mutant analyses indicated that the transactivation function of DA2-6 is expressed by the region that encodes a truncated X-cell fusion product.

1. To study endothelin (ET) receptors in guinea‐pig stomach, ET‐binding assays and in vitro autoradiography were performed on fundic cell suspensions and on sections of the fundus, respectively. ETA and ETB receptor subtypes were found to coexist in the parietal cells. 2. Endothelin 1 (ET‐1) added to the (basolateral) bathing solution was found to activate noisy whole‐cell Cl‐ currents within about 1 min in both single, isolated parietal cells and those within gastric glands obtained from the fundus. 3. ET‐1‐induced Cl‐ currents were rapidly blocked by a Cl‐ channel blocker (NPPB) added to the (basolateral) bathing solution in a concentration‐dependent manner with a half‐maximum inhibition concentration of 33 microM. 4. The anion selectivity sequence of the ET‐1‐induced conductance was I‐ > Br‐ > Cl‐ > F‐, corresponding to Eisenman's sequence I. 5. Changes in extracellular pH between 5 and 8 did not affect the ET‐1‐induced activation of Cl‐ currents. 6. Similar activating effects were also observed with ET‐3 and a specific ETB receptor agonist (IRL1620). An ETB receptor antagonist (IRL1720) prevented the ET‐1 effect, whereas an ETA‐selective antagonist (FR139317 or BQ123) failed to antagonize the ET‐1 effect. 7. In the whole‐cell mode, unitary Cl‐ channel events could be observed in association with ET‐1‐activated macroscopic currents. The single‐channel conductances were around 200 and 350 pS at negative and positive membrane potentials, respectively. 8. It is concluded that gastric parietal cells of guinea‐pig possess pH‐insensitive ‘maxi’ Cl‐ channels coupled to ETB receptors in the basolateral membrane.

Hirschsprung's disease (HSCR) is a congenital intestinal disease, characterized by the absence of ganglion cells in the distal portion of the intestinal tract. Recently, three susceptibility genes have been identified in HSCR, namely the RET protooncogene, the endothelin B (ETB) receptor gene (EDNRB), and the endothelin-3 (ET-3) gene (EDN3). To investigate whether mutations in EDNRB could be related with HSCR in non-inbred populations in Japan, we examined alterations of the gene in 31 isolated patients. Three novel mutations were detected as follows: two transversions, A to T and C to A at nucleotides 311 (N104I) and 1170 (S390R), respectively, and a transition, T to C at nucleotide 325 (C109R). To analyze functions of these mutant receptors, they were expressed in Chinese hamster ovary cells. S390R mutation did not change the binding affinities but caused the decreases in the ligand-induced increment of intracellular calcium and in the inhibition of adenylyl cyclase activity, showing the impairment of the intracellular signaling. C109R receptors were proved to be localized near the nuclei as an unusual 44-kDa protein with the extremely low affinity to endothelin-1 (ET-1) and not to be translocated into the plasma membrane. On the other hand, N104I receptors showed almost the same binding affinities and functional properties as those of the wild type. Therefore, we conclude that S390R and C109R mutations could cause HSCR but that N104I mutation might be polymorphous.

The bacterial fusion protein between glutathione S-transferase and the central conserved region of human p53(GST-p53) was purified and fixed on the beads and then used in the binding assay with radiolabeled cell extract from human hepatocarcinoma cell line, Hep3B. The binding asssay disclosed the presence of cellular proteins that interact with GST-p53 but not with GST. SV40 large T antigen abrogated the bindings of two cellular proteins with molecular weights of 50 kda and 40 kda. The binding of the proteins to p53 was observed in a cell cycle-dependent manner. These two proteins are candidate cellular proteins which regulate the function of p53.Copyright 1994, 1999 Academic Press, Inc.

HBV DNAs are often found in integrated forms in human hepatocellular carcinoma (HCC). Discovery of a transactivation function coded by a limited region of the HBV genome has prompted us to survey our collection of HBV integrants with flanking cellular sequences, asking whether they might exhibit a transactivation function. In transient cotransfection assays using the HepG2 cell line, six out of the twelve integrants showed transactivation effects on the expression of cellular genes such as c-fos. These results strongly demonstrate that the transactivating effects of integrated HBV DNA are widely distributed, and some of these effects might be correlated to hepatocarcinogenesis.

Despite the high degree of homology (91%) between the nucleotide sequences of the Friend-mink cell focus-forming (MCF) and the Moloney murine leukemia virus (MuLV) genomic long terminal repeats (LTRs), the pathogenicities determined by the LTR sequences of the two viruses are quite different. Friend-MCF MuLV is an erythroid leukemia virus, and Moloney MuLV is a lymphoid leukemia virus. To map the LTR sequences responsible for the different disease specificities, we constructed nine viruses with LTRs recombinant between the Friend-MCF and Moloney MuLVs. Analysis of the leukemia induced with the recombinant viruses showed that a 195-base-pair nucleotide sequence, including a 75-base-pair nucleotide Moloney enhancer, is responsible for the tissue-specific leukemogenicity of Moloney MuLV. However, not only the enhancer but also its downstream sequences appear to be necessary. The Moloney virus enhancer and its downstream sequence exerted a dominant effect over that of the Friend-MCF virus, but the enhancer sequence alone did not. The results that three of the nine recombinant viruses induced both erythroid and lymphoid leukemias supported the hypothesis that multiple viral genetic determinants control both the ability to cause leukemia and the type of leukemia induced.

Bone marrow (BM), adult peripheral blood (aPB), and umbilical cord blood (CB) samples contain small proportions of CD34+ cells that include virtually all hematopoietic progenitor cells. Myeloperoxidase (MPO) is considered to be selectively expressed in cells committed to granulomonocytic differentiation. Using flow cytometry and an antibody against MPO, we studied at which stage of normal hematopoietic differentiation CD34+ cells being to express MPO. We consistently observed a characteristic MPO/CD34 staining pattern and found that 35% +/- 9% of CD34+ BM cells express MPO. The MPO+ CD34+ subset and the CD33+ CD34+ subset were of similar size and overlapped considerably. MPO+ CD34+ cells expressed high levels of HLA-D molecules, were weakly CD71/transferrin receptor positive to negative, were CD45RA+ and lacked the CD45RO isoform of the leukocyte common antigen. Additionally, MPO+ CD34+ cells were on average larger in size than MPO- CD34+ cells. Virtually identical phenotypic features have previously been described for in vitro colony-forming granulomonocytic progenitor cells. In vitro clonogenic assays performed with MPO-enriched and MPO-depleted fractions of CD34+ BM cells performed by us also suggest, but do not formally prove, that at least a portion of MPO+ CD34+ cells have in vitro cluster (10 to 50 cells/colony) or colony-forming unit granulocyte-macrophage (> or = 50 cells/colony) forming capacity. CD34+ cells from CB and aPB resembled CD34+ BM cells in that considerable proportions of them coexpressed CD33. However, in contrast to BM, CD34+ cells from CB and aPB samples lacked significant MPO expression and, in line with this, the majority of them (CB, 59% +/- 7%; aPB, 66% +/- 5%) coexpressed CD45RO.

An X-ray study has been carried out in order to investigate the premartensitic phenomena in AuCd alloys. We observed diffuse satellite reflections nearq=(1/3, 1/3,0) and Huang scattering around funda-mental Bragg reflections above the transition temperature to the martensite phase. Satellites observed on (H, K, 0) plane shift off from the commensurate positions, and the shift or the 'incommensurability' forms swirl patterns. These features are the same as the results reported by S. M. Shapiroet al.in a NiTi(Fe) alloy. The results have been discussed in terms of the MLR (modulated lattice relaxation) model and a heterogeneous two phase model.

We have demonstrated that the gibbon ape leukemia virus (GALV) enhancer AP-1 element and the simian virus 40 AP-1 enhancer element bind different factors in HeLa nuclear extracts. A 39-kilodalton HeLa nuclear protein and the c-fos protein bind to the GALV element. Antibodies to c-fos abolish binding to the GALV AP-1 site. In contrast, anti-c-fos immunoglobulin fails to inhibit formation of the simian virus 40-specific complex from extracts of HeLa cells. Thus, AP-1-binding complexes are subject to compositional variation at different binding sites.

A negative element has previously been localized to a 57-base pair segment approximately 300 base pairs upstream of the human c-mycpromoter P1. Within this element, a 26-base pair region was protected in vitrofrom DNase I digestion with a HeLa cell nuclear factor(s). Two specific DNA-protein complexes were identified in gel retardation assays using HeLa cell nuclear extracts and an oligonucleotide probe spanning the footprinted region. Exonuclease and chemical footprint analyses suggested that the binding sites for both complexes are almost entirely overlapping. One of the complexes was eliminated by oligonucleotide competitors possessing known AP-1 binding sites. This same complex reacted strongly with anti-fosimmunoglobulin suggesting a role for c-fosin governing c-mycexpression. Precipitation of fosprotein bound to c-mycDNA that was immobilized on beads confirmed the involvement of c-fosin a specific complex with the c-mycupstream sequence. In contrast, the other complex seen by the c-mycprobe could not be competitively inhibited by AP-1 binding sites and was not affected by anti-fosantibody. Instead, this complex was efficiently eliminated by unlabeled oligonucleotides containing the octamer DNA motif found in immunoglobulin gene promoters. Purified octamer-binding proteins formed stable complexes with the 26-base pair c-mycsequences. These results demonstrate that degeneracy in the consensus recognition sequences of these distinct factors allows each of them to bind the c-mycnegative element. The interaction of known transcriptional activators with a negative element suggests that the same factors can mediate both transcriptional activation and repression.

A homopurine/homopyrimidine-like sequence is found 100-150 base pairs upstream of the human c-myc promoter P1. This element, termed the CT-element, has been shown to augment expression from P1, and it serves as a positive transcriptional element when coupled to a heterologous promoter in vivo and in vitro. Synthetic oligonucleotides comprising this element were used to form DNA-protein complexes in electrophoretic mobility shift assays. By using conventional and affinity methods, 61- and 34-kDa proteins were shown to be associated with these complexes. Amino acid sequence analysis and immunological methods have identified these proteins as heterogeneous ribonucleoprotein particle (hnRNP) proteins K and A1. Surprisingly, hnRNP protein K binds to the pyrimidine-rich strand of the CT-element in a sequence-specific manner as well as to the double-stranded molecule. Cotransfection of vectors encoding hnRNP protein K in the sense or anti-sense orientations with reporter plasmids driven by wild-type or mutant CT-elements demonstrates that hnRNP protein K augments gene expression in a cis-element-dependent manner. Taken together, these results suggest that hnRNP protein K may play a role in the transcriptional regulation of the human c-myc gene.

Syntheses of α-silyl-β,β‘-dialkyl α,β-unsaturated carboxylic acids were achieved from silylated alkyne, carbon dioxide, and a zinc reagent using a catalytic amount of nickel complex in the presence of an excess amount of DBU. The regioselectivity of the introduction of CO2 into disubstituted alkyne is dependent on the electronic property of the substituent R on the alkyne because the thermodynamic stability of oxanickelacycle IV or V should be affected by conjugation of the substituent R with the carboxyl group in IV or V.

Nickel-mediated sequential addition of carbon dioxide and aryl aldehydes into terminal allenes is reported. The reaction proceeded in a diastereoselective manner to afford α-methylene-γ-hydroxy carboxylic acids, which allowed stereoselective preparation of cis-β,γ-disubstituted α-methylene-γ-lactones.

Novel synthetic procedure of heterocycles was developed using nickel-mediated alkylative carboxylation, and the total synthesis of erythrocarine was achieved using this method and RCM of dienyne as the key steps.

Nickel-promoted alkylative or arylative carboxylation of terminal alkynes via a carbon dioxide fixation process was investigated. In the presence of a stoichiometric amount of a zero-valent nickel complex, the reaction of alkynes with CO2 gave a nickelacycle, which was reacted with various organozinc reagents under very mild conditions to provide β,β‘-disubstituted, α,β-unsaturated carboxylic acids in a highly regio- and stereoselective manner.

Carbapenam is a very important skeleton of β-lactam antibiotics, and it has a highly strained structure. When enynes 9 were treated with RuH2CO(PPh3)3 (10 mol %) in toluene upon heating, carbapenams 10 were obtained in good yields.

Summary A 500 mg intramuscular dose of carbenicillin produced peak levels averaging 147µg/ml after three hours in the first day full-term newborn infants, and 172µg/ml after one to two hours in infants five days of age. The fall of blood levels thereafter was delayed and serum half-life averaged 4.2 and 2.2 hours in both groups, almost four times and twice as long, respectively, as that reported in adults. Absorption from the injected site was also delayed in young newborns, as was shown by the delayed serum peak and small estimated absorption rate constant. This must be taken into consideration if the intramuscular route is chosen in young newborn infants. On the basis of serum half-life, an administration interval of 12 hours was recommended for newborns younger than four days, and eight hours for those five days of age or more.

Summary Following an intramuscular dose of 5.0 mg of tobramycin in eight full-term newborn infants, peak levels averaging 2.69 ± 0.70µg/ml were attained after 30 to 60 minutes. The serum half-life thereafter correlated inversely to postnatal age during the first seven days after birth. Pharmacokinetic analysis revealed that in newborn infants the elimination rate was markedly declined, but the absorption rate was nearly the same as that in older children. Average urinary recovery within eight hours was as low as 26.8%, which suggested accumulation of this antibiotic in the renal tissue.

A low threshold current of 47 mA at 20°C has been obtained in a tensile-strained index-guided AlGaInP LD emitting at 625nm, which has an active region consisting of five 8 nm-thick QWs with a lattice mismatch of −0.9%. It is shown that optimisation of the tensile-strained QW structure is very useful in improving the performance of AlGaInP LDs at wavelengths shorter than 630 nm.

CW oscillation at a wavelength shorter than 630 nm, which depends on the Al content incorporated into a tensile-strained single-quantum-well active region of AlGaInP LDs, is investigated. A threshold current of 112 mA at 20°C is attained in a quaternary (AlxGa1−x)InP (x = 0.1) SQW LD emitting at 615 nm.

Gratisin, a peptide antibiotic which shows activity against Bacillus subtilis 720, has been isolated from Bacillus brevis Y‐33. Synthetic studies have shown that the "gratisin"‐related peptide (I) exhibits the same activity against B. subtilis as gramicidin S‐1. In order to investigate the structure‐activity relationship of (I), its analogues (II) and (III) are synthesized using common methods.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The cyclotetradecapeptides (Ia)‐(Id), analogues of gramicidin S (II), are prepared in order to investigate the contribution of the ring size and the amino acid sequences around the proline residue to the antibiotic activity and conformation.