Energy of the

The low-lying isomeric state of ^{229}Th provides unique opportunities for high-resolution laser spectroscopy of the atomic nucleus. We determine the energy of this isomeric state by taking the absolute energy difference between the excitation energy required to populate the 29.2-keV state from the ground state and the energy emitted in its decay to the isomeric excited state. A transition-edge sensor microcalorimeter was used to measure the absolute energy of the 29.2-keV γ ray. Together with the cross-band transition energy (29.2 keV→ground) and the branching ratio of the 29.2-keV state measured in a recent study, the isomer energy was determined to be 8.30±0.92 eV. Our result is in agreement with the latest measurements based on different experimental techniques, which further confirms that the isomeric state of ^{229}Th is in the laser-accessible vacuum ultraviolet range.

Bendamustine-120 plus rituximab therapy for relapsed or refractory follicular lymphoma: a multicenter phase II study.

The optimal dose, schedule, and other aspects of bendamustine plus rituximab treatment remain unclear for patients with relapsed or refractory follicular lymphoma (FL). Herein, we analyzed the efficacy of bendamustine combined with rituximab (RB-120) treatment for Japanese patients with relapsed or refractory FL. This phase II clinical trial included patients with relapsed or refractory FL who received 375 mg/m2 rituximab on day 1 and 120 mg/m2 bendamustine on days 2 and 3 every 28 days for up to 6 cycles. The primary endpoint was the overall response rate (ORR), and the secondary endpoints included the complete response (CR) rate, progression-free survival (PFS), overall survival (OS), and safety. Thirty-seven patients were enrolled in the trial (median age 62 years, range 42-75 years). All patients were previously treated with rituximab-containing chemotherapy, and 83.8% were previously treated with the R-CHOP regimen. A median of 5 cycles (range 1-6) and 48.6% of patients completed 6 cycles. The ORR was 91.9% (95% confidence interval [CI] 78.1-98.3%), with a CR rate of 86.5% (95% CI 71.2-95.5%). The 3-year PFS and OS were 70.9% (95% CI 52.3-83.3%) and 88.9% (95% CI 73.1-95.7%), respectively, with the median 39.5 months follow-up duration. The most-frequently observed grade 3/4 adverse events were hematologic: lymphopenia (95%) and neutropenia (70%). No treatment-related deaths were observed. RB-120 showed a good efficacy with equivalent toxicities, compared with the bendamustine 120 mg/m2 monotherapy. However, the problem of high drop-out incidences cannot be ignored.

Epilepsy and exacerbation of brain injury in mice lacking the glutamate transporter GLT-1.

Extracellular levels of the excitatory neurotransmitter glutamate in the nervous system are maintained by transporters that actively remove glutamate from the extracellular space. Homozygous mice deficient in GLT-1, a widely distributed astrocytic glutamate transporter, show lethal spontaneous seizures and increased susceptibility to acute cortical injury. These effects can be attributed to elevated levels of residual glutamate in the brains of these mice.

[The involvement of c-Abl and D40 (AF15q14/CASC5) proteins in the regulation of cell proliferation and cancer].

Although c-Abl and D40 proteins are localized predominantly in nucleus, they are involved in different cellular processes. c-Abl is a tyrosine-kinase that takes part in protein phosphorylation on tyrosine. Recently D40 has been identified as a component of outer kinetochore complex. Despite of functional differences between c-Abl and D40 proteins, they have some similarities. First, high expression levels of c-Abl and D40 were observed not only in proliferating somatic cells, such as tumors, but also in healthy human testis. The increased expression levels of c-Abl and D40 protein in spermatocytes and acrosome of spermatids indicate their role in meiosis and spermatogenesis. Second, both proteins interact with specific regions of chromatin and are involved in the regulation of cell growth and division. Third, ABL and D40 (AF15q14) genes are involved in chromosomal translocations that subsequently form chimeric oncoproteins BCR-ABL, TEL-ABL and MLL-AF15q14 in human leukaemia. Finally, both proteins interact with the tumor suppressor pRb protein and subsequently can lead to regulation of the cell proliferation. The possible regulatory pathways that are controlled by c-Abl and D40 proteins are described here in details.

Enhanced immunogenicity of the cultured rat fibrosarcoma KMT-17 by cultivation in a low concentration of fetal calf serum.

We examined in different culture conditions alterations in the tumorigenicity and immunogenicity of an A3 clone that had been derived from a rat fibrosarcoma KMT-17. When a fetal calf serum concentration in a culture medium was lowered from 10 to 1%, the tumorigenicity was diminished while the immunogenicity was enhanced in a reversible manner; this was accompanied by a reversible prolongation of the in vitro doubling time. These phenomena were not due to an increase in the quantities of the original tumor-associated antigen and/or of the rat major histocompatibility complex (RT1) but seemed to be due to the appearance of a unique antigen(s) that was detected by an antibody taken from rats immunized with A3 tumor cells cultured in the low fetal calf serum concentration; this antigen(s) may consist of glycoprotein and exist as a crypt antigen(s). These phenomena were measured by an absorption test and flow cytometric analysis. Our observations suggest that the in vitro culture condition of tumor cells, in particular their culturing in the low fetal calf serum concentration medium, modifies the surface of tumor cells and causes a diminishment in their tumorigenicity and an enhancement of their immunogenicity.

Crystal structure of 3-(adenin-9-yl)propionhistamide hydrochloride monohydrate and the role of protonation in protein-nucleic acid interactions.

The three-dimensional structure of 3-(adenin-9-yl)propionhistamide hydrochloride, as a model of interactions between the protonated imidazolyl group and adenine moiety, has been determined by X-ray crystallography. The crystal data are a = 10.314 (1), b = 7.854 (1), c = 20.780 (1) A, beta = 92.765 (4), Z = 4, Dm = 1.32 g X cm-3, space group P2(1)/n. The imidazolium group interacts with adenine moiety by stacking. A comparison with the related neutral derivatives leads to a hypothesis that adenine stacks with the protonated, but not with the neutral, imidazolyl group. Such a characteristic behaviour of the imidazolyl group depending on protonation was shown by ultraviolet and NMR spectroscopy, and by polarographic experiments in solution. We note that a role of the essential histidine in RNAase reaction is a switch between capture and ejection of the substrate, which depends upon proton uptake and its release, respectively.

Molecular analysis of the GCF gene identifies revisions to the cDNA and amino acid sequences(1).

GC factor (GCF) was reported as a transcriptional regulator that binds to a specific GC-rich sequence in the epidermal growth factor receptor (EGFR) gene promoter and represses its expression. In this paper, we present the data on three revisions of the cDNA sequence that lead to significant changes of the amino acid sequences of the published GCF. Firstly, 5'-rapid amplification of cDNA end (5'-RACE) analysis revealed that the 308 nucleotides of 5'-end of the previously published GCF cDNA does not exist at the 5'-end of the RACE product. Simultaneously, the correct 5'-end cDNA sequence of 31 nucleotides was identified. Secondly, the 'T' at the position 787 of the published GCF cDNA was not observed. Finally, a new sequence of 114 nucleotides was identified between the positions 851 and 852 of the published cDNA sequence. The revisions result in a GCF cDNA of 2661 nucleotides that encodes a protein of 781 amino acids, replacing the highly basic region of the amino-terminus of the published GCF with a new sequence of 147 amino acids. In this era of massive gene cloning and sequencing, this study is a warning to the biological research of recent years.

Spectroscopic studies on lambda cro protein-DNA interactions.

Spectroscopic (circular dichroism and fluorescence) and thermodynamic studies were conducted on lambda Cro-DNA interactions. Some base substitutions were introduced to the operator and the effects on the conformation of the complex and thermodynamic parameters for dissociation of the complex were examined. It was found that, (1) in the specific binding of Cro with DNA which has a (pseudo) consensus sequence, DNA is overwound, while in non-specific binding it is unchanged, or rather unwound; (2) substitution of central base-pairs or the introduction of a mismatched base-pair at the center of the operator reduces the extent of DNA conformational change on Cro binding and lessens the stability of the Cro-DNA complex, even though there is apparently no direct interaction between Cro and DNA at these positions; (3) stability of the complex increases with the degree of DNA conformational change of the same type during binding; (4) in some cases of specific binding, there are three states in the dissociation of the complex as observed by salt titration: two conformational states for the complex depending on salt concentration and, in non-specific binding, dissociation is a two-state transition; (5) the number of ions involved in interactions between Cro and 17 base-pair DNA is about 7.7 for NaCl titrations; (6) dissociation free energy prediction of the Cro-DNA complex by simple addition of the dissociation free energy change of a single base-pair substitution agrees with our experimental results when DNA overwinding occurs during binding, i.e. in specific binding.

Endothelin-A receptor-mediated prostanoid secretion via autocrine and deoxyribonucleic acid synthesis via paracrine signaling in human bronchial epithelial cells.

It is known that serum promotes squamous differentiation of airway epithelial cell culture in vitro. We investigated which types of epithelial cells produce endothelins (ETs) and ET-evoked cellular responses in cultured human bronchial epithelial cells (HBECs). Squamous cells, not basal cells (nondifferentiated), secrete ET-1 actively. Specific binding of [125I]ET-1, not [125I]ET-3, was observed in squamous as well as basal cells, demonstrating the existence of only the ETA receptor. ET-1 together with epidermal growth factor stimulated synergistic DNA synthesis in basal cells, whereas ET-1 alone did not. Serum failed to induce DNA synthesis in HBECs, indicating terminal differentiation into squamous cells. ET-1 (1-100 nM) dose-dependently stimulated PGE2 (0.6-2.8 ng/10(5) cells) and thromboxane B2 release (4-30 pg/10(5) cells) from squamous HBECS, but not from basal cells. Western blot analysis showed that both squamous and basal HBECs expressed inducible and endothelial nitric oxide synthase, whereas ET-1 failed to stimulate nitric oxide synthase expression. Our findings suggest that secreted ET-1 from squamous cells evokes the release of prostanoids in an autocrine manner, and stimulates DNA synthesis in basal cells as a comitogen in a paracrine manner. Thus, it is likely that ET-1 secreted from HBECs plays an important role as a local, autocrine, and paracrine modulator in airway responses.

Identification and characterization of a novel trans-membrane protein gene, pdh1, from Schizosaccharomyces pombe.

We have cloned a new gene, pdh1, from genomic DNA of fission yeast Schizosaccharomyces pombe. pdh1 is actively transcribed as 1400-nucleotide mRNA in vegetatively growing cells and can code for a 226 amino acid polypeptide (pdh1p). Computational structural prediction has revealed that the pdh1p is a highly hydrophobic protein with seven transmembrane domains. The prediction has also detected a possible C-kinase phosphorylation site within the longest hydrophilic loop.

Contraction of smooth muscle by activation of endothelin receptors on autonomic neurons.

Endothelin receptors, predominantly of the ETB type, were localized to cell bodies, processes, and varicosities of cholinergic and adrenergic intramural autonomic neurons that were present in primary cultures of guinea pig tracheal smooth muscle. Stimulation of the neuronal ETB receptor produced a tetrodotoxin-sensitive increase in the intracellular calcium concentration in neurons which was followed by contraction of the neighboring smooth muscle cells. These observations suggest that endothelins can induce smooth muscle contraction by means of a neuronally mediated mechanism, in addition to their direct actions on the smooth muscle.

Autocrine receptors for endothelins in the primary culture of endothelial cells of human umbilical vein.

Human umbilical vein endothelial cells (HUVECs) in primary culture produced and secreted endothelin 1 (ET-1) actively. Specific binding of [125I]ET-1 to these cells was not detectable because of the saturation of ET receptors with endogenously produced ET-1. However, addition of phosphoramidon, an inhibitor of ET-converting enzyme, to the medium reduced the production of ET-1 and thus the receptors on HUVECs were made available for exogenously added [125I]ET-1. Binding studies using phosphoramidon-treated HUVECs indicated the existence of a non-isopeptide-selective type (ETB) of ET receptor with a Kd of 17 pM. This receptor is thought to be involved in ET-induced vasodilation in an autocrine manner in vivo.

Breast carcinomas with immunocytochemical detection of aromatase in fine-needle aspirates: report of three cases.

Three postmenopausal women with breast carcinoma underwent the fine-needle aspiration (FNA) preoperatively, and these specimens were stained by the antiaromatase antibody. We evaluated the identification of the aromatase immunoreactivity in breast carcinoma specimens obtained from both FNA and surgery. FNA specimens showed positive intracellular immunoreactivity of aromatase in these cases. The presence for aromatase in FNA specimens was identified with that in the surgical specimens. To our knowledge, the present cases are the first to report the aromatase staining of FNA specimens. The immunoreactivity of aromatase in FNA specimen may be useful to estimate the effectiveness of new aromatase inhibitors in patients with breast carcinoma. HUM PATHOL 32:348-351.

Synergistic effects of the myc and ras oncogenes on ganglioside synthesis by BALB/c 3T3 fibroblasts.

The effects of oncogene activation on glycosphingolipid (GSL) synthesis by a mouse fibroblast clonal cell line were studied. A transfectant that expressed the activated ras gene showed a definite change in the composition of acidic GSLs, probably an increase in polysialoganglioside, while one that expressed the myc gene showed only a slight change. Neither transfectant grew in soft agar. However, another transfectant, which expressed both the myc and ras genes, and grew in soft agar, showed a more dramatic increase in the acidic GSL component. Thus, activations of the myc and ras oncogenes have a synergistic effect on GSL synthesis during transformation.

Nickel-promoted alkylative or arylative carboxylation of alkynes.

[reaction: see text]. 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 beta,beta'-disubstituted, alpha,beta-unsaturated carboxylic acids in a highly regio- and stereoselective manner.

Synthesis of carbapenam skeletons using a ruthenium-catalyzed cyclization.

Carbapenam is a very important skeleton of beta-lactam antibiotics, and it has a highly strained structure. When enynes 9 were treated with RuH(2)CO(PPh(3))(3) (10 mol %) in toluene upon heating, carbapenams 10 were obtained in good yields.

Distinct chromosomal deleted regions defining different subsets of head and neck tumors.

The aim of this work is detecting the loss of heterozygosity (LOH) and its relationship with the development and progression of head and neck cancer. Matched normal and tumor DNA from 81 patients with head and neck cancer were examined for LOH using six microsatellite repeat markers mapped to chromosomal regions 3p13, 6q13, 9p21, 11p15, 17p13.1, and 17q22. LOH frequency at a locus ranged from 21% to 55%. The highest frequencies were at 3p (41%), 9p (48%), and 17p (54%). Thirty-two of 81 tumor samples showed allelic loss at more than one region. Significant associations were found between LOH at 3p and 9p (P = 0.001), 9p and 11p (P = 0.03), and 9p and 17p (P = 0.007). LOH at 11p was frequent in tumors from the oral cavity (5/17), oropharynx (2/7), and hypopharynx (5/10), but absent in tumors from the larynx (0/11) (P = 0.02), and LOH at 17q was observed in tumors from oral cavity (10/30) and hypopharynx (3/9), but not in tumors from the oropharynx (0/10) or larynx (0/13) (P = 0.003). In addition to that, the occurrence of allelic losses at 9p and 17p strongly correlates to tobacco smoking (P = 0.03 and P = 0.006, respectively) and alcohol intake (P = 0.01 and P = 0.005, respectively). These results suggest that tumors from different sites have different LOH patterns and corroborate with epidemiological data implicating tobacco and alcohol in the etiology of head and neck tumors.

Increases of vascular endothelin-converting enzyme activity and endothelin-1 level on atherosclerotic lesions in hyperlipidemic rabbits.

The aim of this study was to investigate vascular endothelin-converting enzyme activity and the tissue level of endothelin-1 in the aorta related to atherosclerotic lesions in high cholesterol diet-fed rabbits. Rabbits were fed two atherogenic diets, 0.5% and 1.5% cholesterol, and a normal diet for 16 weeks. Vascular endothelin-converting enzyme activity in the aortic arch and thoracic aorta was significantly increased (2.0-4.4 times) by the atherogenic diet as compared with the normal diet group as well as the levels of lipids and lipid peroxide in plasma were significantly increased. Tissue endothelin-1 levels in both aortas were also elevated (2.3-6.8 times), corresponding well to the increased tissue enzyme activity. In contrast, plasma endothelin-1 levels increased only in the 1.5% cholesterol diet group (2.7 times). These results indicate that the endothelin-converting enzyme activity and the corresponding endothelin-1 level in the vascular walls increase in association with the development of atherosclerotic lesions.

Cocaine-induced liver injury in mice is mediated by nitric oxide and reactive oxygen species.

The modulating effects of nitric oxide (NO) and reactive oxygen species on cocaine-induced hepatotoxicity were examined by measuring plasma alanine aminotransferase activity and by carrying out histological studies. Liver injury was induced by a single injection of cocaine in adult male ICR mice. Pretreatment with aminoguanidine (an inhibitor of NO synthase), N-methyl-D-glucamine dithiocarbamate complex with iron ion (II) (Fe2+(MGD)2, a trapping reagent of NO) or deferoxamine complex with iron ion (III) (Fe3+-deferoxamine, a scavenger of NO) produced a marked inhibition of the hepatotoxicity induced by cocaine. In addition, pretreatment with allopurinol (an inhibitor of xanthine oxidase) and 1,3-dimethylthiourea (a scavenger of hydroxyl radical) also produced a potent inhibition. These findings suggest that a hydroxyl radical produced by the reaction of NO and superoxide anion (O2-) via peroxynitrite may be involved in the pathogenesis of cocaine hepatotoxicity.