Limits on spin-independent couplings of WIMP dark matter with a p-type point-contact germanium detector

We report new limits on a spin-independent weakly interacting massive particle (WIMP)-nucleon interaction cross section using 39.5 kg days of data taken with a p-type point-contact germanium detector of 840 g fiducial mass at the Kuo-Sheng Reactor Neutrino Laboratory. Crucial to this study is the understanding of the selection procedures and, in particular, the bulk-surface events differentiation at the sub-keV range. The signal-retaining and background-rejecting efficiencies were measured with calibration gamma sources and a novel n-type point-contact germanium detector. Part of the parameter space in the cross section versus WIMP-mass implied by various experiments is probed and excluded.

Limit on the electron neutrino magnetic moment from the kuo-sheng reactor neutrino experiment

A search of neutrino magnetic moment was carried out at the Kuo-Sheng Nuclear Power Station at a distance of 28 m from the 2.9 GW reactor core. With a high purity germanium detector of mass 1.06 kg surrounded by scintillating NaI(Tl) and CsI(Tl) crystals as anti-Compton detectors, a detection threshold of 5 keV and a background level of 1 kg(-1) keV(-1) day(-1) at 12-60 keV were achieved. Based on 4712 and 1250 h of reactor ON and OFF data, respectively, the limit on the neutrino magnetic moment of mu(nu;(e))<1.3x10(-10)mu(B) at 90% confidence level was derived. An indirect bound of the nu;(e) radiative lifetime of m(3)(nu)tau(nu)>2.8x10(18) eV(3) s can be inferred.

Stereoselective synthesis of delta-lactones from 5-oxoalkanals via one-pot sequential acetalization, Tishchenko reaction, and lactonization by cooperative catalysis of samarium Ion and mercaptan

By the synergistic catalysis of samarium ion and mercaptan, a series of 5-oxoalkanals was converted to (substituted) delta-lactones in efficient and stereoselective manners. This one-pot procedure comprises a sequence of acetalization, Tishchenko reaction and lactonization. The deliberative use of mercaptan, by comparison with alcohol, is advantageous to facilitate the catalytic cycle. The reaction mechanism and stereochemistry are proposed and supported by some experimental evidence. Such samarium ion/mercaptan cocatalyzed reactions show the feature of remote control, which is applicable to the asymmetric synthesis of optically active delta-lactones. This study also demonstrates the synthesis of two insect pheromones, (2S,5R)-2-methylhexanolide and (R)-hexadecanolide, as examples of a new protocol for asymmetric reduction of long-chain aliphatic ketones.

Polymer-supported benzotriazoles as catalysts in the synthesis of tetrahydroquinolines by condensation of aldehydes with aromatic amines

Four polymer-supported benzotriazoles were prepared by linkage of 5-(hydroxymethyl)benzotriazole and benzotrizaole-5-carboxylic acid with Wang resin, Merrifield resin, and (monomethoxy)poly(ethylene glycol). The solid-phase and liquid-phase syntheses of tetrahydroquinolines were achieved by two-pair coupling reactions of aldehydes and aromatic amines using these polymer-supported benzotriazoles as the promoters. The ether-type benzotriazole prepared by loading 5-(hydroxymethyl)benzotriazole onto Merrifield resin turned out to be the catalyst of choice. Thus, a series of tetrahydroquinoline products were obtained in high purity by simple filtration, and the resin was recovered for reuse without loss of activity.

Synthesis of Ferrocenyl Alkenes, Dienes, and Enynes via Samarium Diiodide Promoted Tandem Addition and Dehydration of Ferrocenyl Carbonyls with Halides

A practical method for preparation of ferrocenyl alkenes, dienes, and enynes from ferrocenyl carbonyls was explored. A one-pot operation using samarium diiodide to promote the condensation reactions of ferrocenecarboxaldehyde, acetylferrocene, benzoylferrocene, and butanoylferrocene with benzyl bromides, allyl bromide, propargyl bromide, and 1-bromo-3-chlorobutane gave the olefinic products in very high yields. The condensation reactions were also achieved by using catalytic amounts of SmI(2) with magnesium to regenerate the divalent samarium reducing agent.

Translocation breakpoints in FHIT and FRA3B in both homologs of chromosome 3 in an esophageal adenocarcinoma

Common fragile sites have been proposed to play a mechanistic role in chromosome translocations and other rearrangements in cancer cells in vivo based on their behavior in vitro and their co-localization with cancer translocation breakpoints. This hypothesis has been the subject of controversy, because associations have been made at the chromosomal level and because of the large number of both fragile sites and cancer chromosome breakpoints. Tests of this hypothesis at the molecular level are now possible with the cloning of common fragile site loci and the use of fragile site clones in the analysis of rearranged chromosomes. FRA3B, the most frequently seen common fragile site, lies within the large FHIT gene. It is now well established that this region is the site of frequent, large intragenic deletions and aberrant transcripts in a number of tumors and tumor cell lines. In contrast, only one tumor-associated translocation involving the FHIT gene has been reported. We have found translocations in both homologs of chromosome 3 in an early-passage esophageal adenocarcinoma cell line. This cell line showed no normal FHIT transcripts by reverse transcription polymerase chain reaction. Subsequent chromosome analysis showed translocations of the short arms of both homologs of chromosome 3: t(3;16) and t(3;4). The breakpoints of both translocations were shown by fluorescence in situ hybridization and polymerase chain reaction to be in the FHIT gene, at or near the center of the fragile site region. Using rapid amplification of cDNA ends with FHIT primers, a noncoding chimeric transcript resulting from t(3;16) was identified. These data provide direct support for the hypothesis that FRA3B, and likely other common fragile sites, may be "hot spots" for translocations in certain cancers, as they are for deletions, and that such translocations have the potential to form abnormal chimeric transcripts. In addition, the results suggest selection for loss of a functional FHIT gene by the translocation events.

Characterization and esterification of hemicelluloses from rye straw

Hemicelluloses were extracted with 10% KOH/0.5% Na(2)B(4)O(7). 10H(2)O from delignified rye straw. Esterification of the hemicelluloses with various acyl chlorides was performed in a homogeneous N,N-dimethylformamide and lithium chloride system using 4-(dimethylamino)pyridine catalyst and triethylamine as a neutralizer. The degree of substitution was controlled between 0.37 and 1.65. Under an optimum condition (sample 14, molar ratio 3:1), >90% of the free hydroxyl groups in native hemicelluloses were stearoylated at 75 degrees C for 40 min. Meanwhile, the products were characterized by FT-IR and GPC techniques as well as their solubilities. The molecular mass measurements (31400-123300 g mol(-)(1)) showed only a minimal degradation of the macromolecular hemicelluloses during rapid reactions at 48-75 degrees C for 20-40 min.

[Plasmodium falciparum: antimalarial activities of antisense oligodeoxyribonucleotides targeted to histidine-rich protein genes in vitro]

OBJECTIVE

To study the inhibition of growth of Plasmodium falciparum cultured in vitro with antisense oligodeoxyribonucleotide (AS ODN) against histidine-rich proteins (HRP).

METHODS

The ODNs against HRP II and HRP III were synthesized and used to study the antimalarial activities in vitro. Plasmodium falciparum (FCC1/HN strain, China) were exposed to AS DONs for 48 h, and the growth inhibition was determined by microscopic examination.

RESULTS

At 1 mumol/L, all ODNs inhibited parasite growth and development in a target-independent manner. However, when the ODN concentrations were between 0.01 and 0.5 mumol/L, the AS ODN significantly inhibited the growth and development of P. falciparum compared with ODN controls (P < 0.01). Inhibition by the sense strand ODN did not differ significantly from the control group (P > 0.05).

CONCLUSION

Blockade of the expression of HRP II and HRP III AS ODN could inhibit P. falciparum cultured in vitro.

Physicochemical and structural characterization of alkali soluble lignins from oil palm trunk and empty fruit-bunch fibers

Six alkali soluble lignin fractions were extracted from the cell wall materials of oil palm trunk and empty fruit-bunch (EFB) fibers with 5% NaOH, 10% NaOH, and 24% KOH/2% H(3)BO(3). All of the lignin fractions contained rather low amounts of associated neutral sugars (0.8-1.2%) and uronic acids (1.1-2.0%). The lignin fractions isolated with 5% NaOH from the lignified palm trunk and EFB fibers gave a relatively higher degree of polymerization as shown by weight-average molecular weights ranging between 2620 and 2840, whereas the lignin fractions isolated with 10% NaOH and 24% KOH/2% H(3)BO(3) from the partially delignified palm trunk and EFB fibers showed a relatively lower degree of polymerization, as shown by weight-average molecular weights ranging between 1750 and 1980. The results obtained by alkaline nitrobenzene oxidation showed that all of the lignin preparations contained a high proportion of noncondensed syringyl units with small amounts of noncondensed guaiacyl and fewer p-hydroxyphenyl units. The lignin fraction extracted with 5% NaOH from the lignified EFB fiber was mainly composed of beta-O-4 ether-linked units. Small amounts of 5-5', beta-5, and beta-beta' carbon-carbon linkages were also found to be present between the lignin structural units. Further studies showed that uronic, p-hydroxybenzoic, and ferulic acids in the cell walls of palm fibers were esterified to lignin.

CD10 antigen expression correlates with the t(14;18)(q32;q21) major breakpoint region in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a common morphologic term for a biologically diverse group of lymphomas. The chromosome translocation, t(14;18)(q32;q21), and its associated bcl-2 gene rearrangement are generally associated with follicular lymphomas. Some investigators, however, proposed that the presence of the t(14;18) in DLBCL suggests a possible follicle center cell origin and might correlate with a higher relapse rate after therapy. The CD10 antigen is expressed in a majority of follicular lymphomas but is also seen occasionally in DLBCLs. In this study, we examined 26 DLBCLs for CD10 expression by flow cytometric analysis and tested them for the t(14;18)(q32;q21) major breakpoint region by a polymerase chain reaction-based method. bcl-2 protein expression was analyzed by an immunoperoxidase method. Of the 26 DLBCLs, 9 (35%) were CD10 positive. bcl-2 protein was expressed in 7 (78%) of 9 CD10-positive cases and in 9 (53%) of 17 CD10-negative cases (P = .4). The t(14; 18) translocation was present in 6 (67%) of 9 CD10-positive cases but in only 2 (17%) of 12 CD10-negative cases (P = .03). Five cases did not yield amplifiable DNA for analysis. In summary, no difference in bcl-2 protein expression was seen in CD10-positive versus CD10-negative DLBCLs, but CD10-positive DLBCLs were significantly more likely than CD10-negative DLBCLs to harbor the t(14;18) translocation. This suggests that CD10 might be a marker of follicle center cell origin in DLBCL.

Gene amplification and high-level expression of human pro-urokinase cDNA in Chinese hamster ovary cells

Human Pro-Urokinase (Pro-UK) is expressed in CHO-DHFR- cells at high efficiency by co-transfecting the mouse dhfr gene and Pro-UK cDNA under the control of the SV40 late promoter. After gene co-amplification, the product level could reach 2-3 micrograms/10(6) cells/24 h in the presence of 5 x 10(-6) mol/L MTX, and the levels can be further raised to 3.5-4 micrograms/10(6) cells/24 h by PMA superinduction. The copy number of Pro-UK cDNA in the genomes of host cells is about 200-300 copies/cell. The Western blot analysis shows that the recombinant Pro-UK has similar molecular weight to its natural counterpart, and also the amidolytic activity of the product is determined by S-2444 assay.

Activation of melatonin receptor sites retarded the depletion of norepinephrine following inhibition of synthesis in the C3H/HeN mouse hypothalamus

The aim of the present study was to determine the effect of activation of melatonin receptor sites on the activity of noradrenergic neurons in the C3H/HeN mouse brain. Changes in noradrenergic activity were assessed by measuring norepinephrine (NE) levels in the hypothalamus, frontal cortex, and hippocampus following inhibition of NE synthesis with alpha-methyl-p-tyrosine (alpha-MpT) (300 mg/kg, i.p., 2 h). 6-Chloromelatonin (1-30 mg/kg, i.p.) significantly retarded the alpha-MpT-induced decrease in NE levels in the hypothalamus, but not in hippocampus and frontal cortex. This effect was observed at 30 min and 60 min after 6-chloromelatonin administration and was dose dependent. At noon, when the levels of endogenous melatonin are low, the melatonin receptor antagonist luzindole (30 mg/kg, i.p., 30 min) did not affect the depletion of NE by alpha-MpT; however, it (1-30 mg/kg) completely antagonized the 6-chloromelatonin-induced reduction of NE depletion elicited by alpha-MpT in hypothalamus. These results suggest that activation of melatonin receptor sites in brain of C3H/HeN mouse retarded the depletion of NE elicited by alpha-MpT. At midnight, when the levels of melatonin are high, luzindole (30 mg/kg) significantly accelerated the depletion of NE by alpha-MpT in hypothalamus, but not in frontal cortex or hippocampus, suggesting activation of melatonin receptor sites by endogenous melatonin. We conclude that activation of melatonin receptor sites in C3H/HeN mouse brain by endogenous melatonin inhibits the activity of noradrenergic neurons innervating the hypothalamus.

Autoradiographic localization of 2-[125I]iodomelatonin binding sites in the brains of C3H/HeN and C57BL/6J strains of mice

The present study uses in vitro autoradiography to localize 2-[125I]iodomelatonin binding sites in the brains of two strains of mice, the C3H/HeN and the C57BL/6J, which have been shown to exhibit differences in pineal melatonin content. We found a differential pattern of distribution of 2-[125I]iodomelatonin binding sites between the two strains with the suprachiasmatic nucleus, paraventricular nucleus of the thalamus, and the median eminence/pars tuberalis regions labelled in both strains. These studies should help to interpret behavioral changes due to activation of melatonin receptors in these strains of mice.

Effects of melatonin agonists and antagonists on reproduction and body weight in the Siberian hamster

This study examined whether melatonin-induced inhibition of testicular weight and body weight in vivo could be antagonized by luzindole, a competitive melatonin receptor antagonist, or methysergide, a competitive serotonin receptor antagonist. Adult male Siberian hamsters were exposed to a long photoperiod (16L:8D) and given daily injections of drugs 3 h before lights off for 7 weeks. Hamsters treated with melatonin (0.375 mg/kg) exhibited testicular regression and loss of body weight. These effects were also marked in hamsters treated concomitantly with melatonin (0.375 mg/kg) and luzindole (10 mg/kg). In other studies, chronic injections of luzindole (30 mg/kg) to juvenile hamster failed to antagonize testicular regression induced by either melatonin injections or exposure to a short day photoperiod (12L: 12D). In contrast, concommitant injections of methysergide (6.25 mg/kg) and melatonin attenuated testicular regression and loss of body weight. When administered alone, neither luzindole nor methysergide affected testicular weight or body weight, whereas chronic injections of 5-methyoxyluzindole (10 mg/kg) mimicked the inhibitory effects of melatonin. 5-Methoxyluzindole inhibits 2-[125I]-iodomelatonin binding to median eminence/pars tuberalis membranes with an affinity similar to that of melatonin. Luzindole shows lower affinity for the inhibition of 2-[125I]-iodomelatonin binding than melatonin, which may explain why luzindole is not an effective melatonin receptor antagonist when administered in vivo. Methysergide, which has a very low affinity for inhibition of 2-[125I]-iodomelatonin binding, probably inhibits the effects of melatonin by blocking serotonergic neurotransmission.

Observation of activity of IL-2 produced by mononuclear cells in tumor draining lymph-node

The activity of IL-2 produced by mononuclear cells in draining lymph-onde and peripheral blood from patients with cancer was investigated. It was found that, though the activity of IL-2 produced by peripheral blood mononuclear cells from these patients became much lower, the activity of IL-2 produced by draining lymph node mononuclear cells from the same donors showed no decline, in contrast to non-malignant patients and healthy controls. What is more, the NK cells of tumor draining lymph-nodes responded as strong to xenogenous IL-2 as those of draining lymphnodes from patients with non-malignant disease. The results suggested that some of the immune functions of tumor draining lymph-node mononuclear cells might be more stable than those of peripheral blood mononuclear cells in patients suffering from cancer, and that local injection of xenogenous IL-2 might enhance the anti-cancer activity of tumor draining lymph-node.