Quantum non-demolition readout of an electron spin in silicon.

While single-shot detection of silicon spin qubits is now a laboratory routine, the need for quantum error correction in a large-scale quantum computing device demands a quantum non-demolition (QND) implementation. Unlike conventional counterparts, the QND spin readout imposes minimal disturbance to the probed spin polarization and can therefore be repeated to extinguish measurement errors. Here, we show that an electron spin qubit in silicon can be measured in a highly non-demolition manner by probing another electron spin in a neighboring dot Ising-coupled to the qubit spin. The high non-demolition fidelity (99% on average) enables over 20 readout repetitions of a single spin state, yielding an overall average measurement fidelity of up to 95% within 1.2 ms. We further demonstrate that our repetitive QND readout protocol can realize heralded high-fidelity (>99.6%) ground-state preparation. Our QND-based measurement and preparation, mediated by a second qubit of the same kind, will allow for a wide class of quantum information protocols with electron spins in silicon without compromising the architectural homogeneity.

A novel Fe(II)/α-ketoglutarate-dependent dioxygenase from Burkholderia ambifaria has ß-hydroxylating activity of N-succinyl l-leucine.

An Fe(II)/α-ketoglutarate-dependent dioxygenase, SadA, was obtained from Burkholderia ambifaria AMMD and heterologously expressed in Escherichia coli. Purified recombinant SadA had catalytic activity towards several N-substituted l-amino acids, which was especially strong with N-succinyl l-leucine. With the NMR and LC-MS analysis, SadA converted N-succinyl l-leucine into N-succinyl l-threo-ß-hydroxyleucine with >99% diastereoselectivity. SadA is the first enzyme catalysing ß-hydroxylation of aliphatic amino acid-related substances and a potent biocatalyst for the preparation of optically active ß-hydroxy amino acids.

Quantitative estimation of exchange interaction energy using two-electron vertical double quantum dots.

We use Pauli-spin blockade in two-electron vertical double quantum dots to quantitatively estimate the exchange energy J in a wide range of interdot level detuning Delta and fully compare it with calculations. Pauli-spin blockade is lifted via a singlet- (S-)triplet (T) transition mediated by hyperfine coupling, which abruptly occurs in our devices when the S-T transition energy or J is compensated by the Zeeman energy. We use this feature to derive J depending on Delta between the S-S and T-T resonances. The obtained J versus Delta including the resonance effect is perfectly reproduced by Hubbard model calculations.

Evaluation of functional relationships for predicting mainstream smoke constituent machine yields for conventional cigarettes from the Japanese market.

The objective of this study was to predict mainstream smoke constituent yields for conventional filter cigarette brands on sale in Japan between 2004 and 2005. Mainstream smoke was generated under ISO machine smoking conditions. Developed functional relationships indicate the validity of benchmarking even for a market which is characterized by a diversity of tobacco blend types. Smoke yields were in general well predicted by linear regression with "tar" (R2>or=0.7). Blend-type-sensitive analytes like tobacco-specific nitrosamines showed improved prediction relationships after blend stratification or regressing against nitric oxide (NO, R(2)>0.7). Relationships calculated from 83 exploratory brands were validated with a subset of 23 validation brands. Seventy-five to one-hundred percent of the validation brand yields were inside the 95% prediction intervals. The mean-relative prediction error over all analytes was 24% after stratification. Smoke constituents yields analyzed in 2002 from 96 Japanese market products were well predicted and indicate the model validity over time. Similar relationships were observed when comparing American blended filter cigarette yields from Japan and worldwide markets. Consistent with reported results from previous benchmark studies and market surveys mainstream smoke constituent yields are well predictable when "tar" (and NO) yields are known.

Expression of activation-induced cytidine deaminase decreases throughout the life.

Activation-induced cytidine deaminase (AID) is an RNA editing enzyme, which contributes to generation of new functional genes from a restricted number of genes of plant and animal genome. This enzyme was involved in the process of somatic mutation and class switching in vertebrate. Since the rate of somatic mutations is variable throughout ontogeny, we have studied the transcription of AID in 3 to 24 month-old Balb/c mice. Our results demonstrate a significant decrease of the transcription of the AID gene with aging. The decreased AID activity is not related to variation of phenotypic and functional properties of B cells throughout the life. This observation can explain the low rate of somatic mutation in aged animals.

A repressor element in the 5'-untranslated region of human Pax5 exon 1A.

B-cell-specific activator protein (BSAP) encoded by the Pax5 gene plays a critical role during B-cell development. We have analyzed the 5'-flanking region plus the 5'-untranslated region (5'-UTR) of human Pax5 exon1A to clarify its regulatory mechanisms. Functional dissection of these regions by luciferase reporter assays indicated that a cluster of regulatory elements acts as a strong repressor between +320 and +453. Insertion of this segment between the heterologous simian virus 40 (SV40) promoter and the luciferase gene in both the sense and reverse orientation sharply reduced the luciferase activity, but insertion into the upstream of the SV40 promoter did not. This suggests that this segment must be located in the 5'-UTR to function effectively. A search through databases with the sequence of this segment did not reveal any known DNA binding factor site. Electrophoretic gel mobility shift assay (EMSA) experiments demonstrated that unknown factors bound to the fragment +408 to +429. Insertion of this fragment between the SV40 promoter and the reporter gene strongly suppressed the luciferase activity. Competitive EMSA indicated that the region between nucleotides +413 and +427 encompassed the binding site of the unknown factors and was hence regarded as a repressor element. Mutagenesis in this element significantly recovered reporter gene activity. These results suggest that the segment +320 to +453, especially the repressor element +413 to +427, in the 5'-UTR is involved in the regulation of Pax5 gene expression.

Angiotropic B-cell lymphoma with hemophagocytic syndrome associated with syndrome of inappropriate secretion of antidiuretic hormone.

A case of angiotropic B-cell lymphoma associated with hemophagocytic syndrome (HPS) has been reported. In addition to fever, pancytopenia, hepatosplenomegaly, and lack of lymphadenopathy, unique clinical features, such as syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and pulmonary infarction, were manifested. Both soluble interleukin-2 receptor (sIL-2R) and IL-6 were elevated in the patient's sera in addition to an increase of serum lactate dehydrogenase and ferritin. In contrast, tumor necrosis factor-alpha and interferon-gamma were within normal ranges. Serum antibodies against Epstein-Barr virus and cytomegalovirus showed a past infection pattern. An autopsy examination revealed systemic intravascular proliferation of lymphoma cells with a B-cell phenotype, confirming the diagnosis of angiotropic B-cell lymphoma. Moreover, SIADH was suggested to result from the infiltration of tumor cells into the pituitary gland. Triple association of angiotropic B-cell lymphoma, HPS and SIADH is quite rare. Therefore, the present case seems to be helpful for clarifying the mechanism for HPS of non-Hodgkin's lymphoma with B-cell origin.

The expression and activation of matrix metalloproteinase-2 in rat brain after implantation of C6 rat glioma cells.

It has been reported that matrix metalloproteinases (MMPs) are highly expressed in malignant glioma cells and that this increased expression may facilitate the invasiveness of tumor cells. The authors investigated the expression and enzymatic activity of MMPs in rat brain during the growth of malignant gliomas at different time intervals. C6 rat glioma cells were unilaterally implanted into rat cerebral hemispheres. After 7 or 14 days, these brain tissues were prepared for SDS-PAGE zymography, Western blotting, immunohistochemistry, and in situ zymography. SDS-PAGE zymography and Western blotting revealed that the expression of proMMP-2 in rat brains with C6 glioma cells was significantly higher than that in normal or the sham-operated rat brains, and that the activated form of MMP-2 was detected only in the former but not in the latter. On immunohistochemistry, C6 glioma cells presenting invasive growth into the rat brain parenchyma and vessels demonstrated MMP-2 immunoreactivity. On in situ zymography, foci of invasive C6 glioma cells in rat brain tissue showed gelatinolytic activity. These results suggest that expression and activation of MMP-2 may be one of the crucial steps for glioma cell invasion into the brain parenchyma in vivo.

Identification of breakpoint cluster regions at 1p36.3 and 3q21 in hematologic malignancies with t(1;3)(p36;q21).

The reciprocal translocation t(1;3)(p36;q21) is associated with myelodysplastic syndromes (MDSs) and acute myeloid leukemia (AML) characterized by trilineage dysplasia, in particular dysmegakaryocytopoiesis, and a poor prognosis. As yet no molecular genetic analyses of the t(1;3) have been reported. In four patients with t(1;3), all of whom had AML-M4, which evolved from MDS, the breakpoints at 3q21 clustered within a 60-kb region centromeric to the breakpoint of the inv(3)(q21q26), whereas the breakpoints at 1p36 clustered within a 90-kb region at 1p36.3. The presence of novel clusters in both the 3q21 and 1p36 breakpoints (BCRs) suggests a common, underlying molecular mechanism for the development of t(1;3)-positive MDS/AML. The Ribophorin I (RPN1) gene close to the BCR at 3q21 was highly expressed without gross structural changes, whereas the GR6 gene located within the BCR at 3q21 was not expressed. No other highly expressed genes were isolated in a 150-kb region at 3q21. Thus, it is likely that a gene at 1p36.3 is activated by the translocation of the 3q21 region or a gene important for transformation lies on 3q21, outside the 150-kb region. Further characterization of the BCRs at 1p36.3 and 3q21 should provide important insights into the molecular genetic mechanisms involved in the genesis of t(1;3)-positive MDS/AML. Genes Chromosomes Cancer 27:229-238, 2000.

Expression of matrix metalloproteinases in the chronic subdural haematoma membrane.

To study the role of matrix metalloproteinases (MMP) in the development of chronic subdural haematoma, we investigated the expression and activity of MMPs (MMP-1, -2, -3, -7 and -9) and tissue inhibitors of MMP (TIMP-1 and -2) in capsules of chronic subdural haematoma from 10 patients. Outer membranes of chronic subdural haematoma were immunostained for MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2. Moreover, we confirmed MMP activity in membranes by SDS-PAGE zymography and in situ zymography. These results suggest that MMP degrades extracellular matrix in outer membranes of chronic subdural haematoma, which is thought to decrease their integrity followed by direct haemorrhage and exudation of oedematous fluid from membrane vessels into the haematoma cavity.

Analysis of the proliferative potential of tumor cells after stereotactic radiosurgery for recurrent astrocytic tumors.

We analyzed the effectiveness of stereotactic radiosurgery (SRS) for recurrent astrocytic tumors histologically. Five patients were followed by pathological examination after radiosurgery treatment of recurrent astrocytic tumors. Histological diagnoses at the time of the last operation before SRS were Daumas-Duport grade II in two patients and grade IV (glioblastoma) in three patients. No histological diagnoses at the time of SRS were identified in any patients. Contrast enhanced lesions enlarged gradually on magnetic resonance (MR) images after SRS, and local control by SRS was judged as progressive disease radiologically in all patients. Four of five patients received re-operation after SRS, and the other patient died without re-operation and underwent post-mortem examination. After SRS, Ki-67 labeling indices (LIs) of recurrent astrocytomas initially diagnosed as grade II were 2.6% and 1.1%. These LIs were relatively lower than those of the control group of patients with recurrent grade II astrocytomas that were not treated by SRS. Ki-67 LIs of three glioblastomas after SRS were 23.5%, 18.6%, and 17.8%. These LIs were significantly lower than those before SRS (2.3%, 4.5%, and 0.9%). In the autopsy case, there was a significant difference between the LI of tumor cells in the radiosurgically treated region (0.9%) and that in the untreated region (29.2%). These results suggest that the proliferative potential of malignant astrocytic tumors in the radiosurgically treated area is reduced after SRS, and that radiological enlargement of enhanced lesions on MR images is due to propagation of the residual tumor cells that were not covered by radiosurgical target volume or to radiation necrosis. SRS may be a useful therapeutic tool in multidisciplinary treatment of malignant gliomas.

In vivo anti-tumor activity of a novel indolocarbazole compound, J-107088, on murine and human tumors transplanted into mice.

J-107088 (6-N-(1-hydroxymethyl-2-hydroxy)ethylamino-12,13-dihydro-2,10-dihydroxy- 13-(beta-D-glucopyranosyl)-5H-indolo[2,3-a]-pyrrolo [3,4-c]carbazole-5,7(6H)-dione) is a derivative of NB-506, an indolocarbazole compound previously reported as an anti-tumor agent targeting topoisomerase I. The optimal administration schedule of J-107088 was found to be intermittent injections. The GID75 (75% growth inhibiting total dose) values of J-107088 against LX-1 lung cancer and PC-3 prostate cancer when given by intermittent injection (twice a week for 2 consecutive weeks) were 200 and 15 mg/m2, respectively, whereas the 10% lethal dose (LD10) values of J-107088 against LX-1- and PC-3-bearing mice were 578 and 1200 mg/m2. The ratio of LD10/GID75 indicates the therapeutic window of an anti-tumor agent. Although the ratios of doxorubicin, paclitaxel and cisplatin against PC-3 were <0.3, <0.5 and <0.2, J-107088 showed the widest therapeutic window among the anti-tumor drugs tested. J-107088 was also effective on cells that had acquired resistance related to P-glycoprotein. Furthermore, J-107088 was found to be highly effective in inhibiting proliferation of micro-metastases of tumors to the liver in mice. Therefore, J-107088 is considered to be a promising candidate as an anti-tumor drug for treatment of solid tumors in humans.

Activation of EVI1 transcripts with chromosomal translocation joining the TCRVbeta locus and the EVI1 gene in human acute undifferentiated leukemia cell line (Kasumi-3) with a complex translocation of der(3)t(3;7;8).

A cell line (Kasumi-3) established from acute myeloid leukemia (AML-M0) had unique phenotypes of undifferentiated leukemia cells with expression of both T cell and myeloid antigens. Kasumi-3 cells with t(3;7)(q26;q22) highly expressed a 6 kb transcript of EVI1, which is located on chromosome 3q26. Therefore, we further characterized the chromosomal breakpoint by pulsed-field gel electrophoresis near EVI1. We identified and isolated the chromosomal breakpoint at approximately 80 kb upstream from the 5' end of EVI1. Sequence analysis of the breakpoint revealed that the whole Vbeta region from T cell receptor beta (TCRbeta) at 7q35 was translocated to the upstream of EVI1. A 1.0 kb TCRbeta transcript was expressed in the Kasumi-3 cells, suggesting that TCRbeta rearrangement occurred as Dbeta-Jbeta joining events. Fluorescence in situ hybridization analysis revealed that the inverted chromosome 7q22-q35 segment between TCRbeta and the region proximal to the erythropoietin gene at 7q22 was translocated to the region distal to EVI1 in der(3). Since the telomeric region of chromosome 8 q was also translocated to the inverted chromosome 7q22-q35 segment in der(3), the chromosomal abnormalities of der(3) were defined as being der(3)t(3;7;8)(3pter-3q26::7q35-7q22::8q22 -8qter). It is suggested that a translocated enhancer element in the TCRbeta locus and/or loss of a negative regulatory element near EVI1 might function to enhance the EVI1 expression. Therefore, the enhanced EVI1 expression may contribute to the development of a subset of undifferentiated leukemia.

Ecotropic viral integration site-1 is activated during, and is sufficient for, neuroectodermal P19 cell differentiation.

Expression of the ecotropic viral integration site-1 (Evi1) proto-oncogene during murine embryonal development is observed by in situ hybridization in primary head folds and neural crest-derived cells associated with the peripheral nervous system and embryonic mesoderm. To elucidate whether expression of Evi1 is involved in early neuroectodermal or mesodermal differentiation, we used murine embryonal carcinoma P19 cells as a model for the study of early embryonic differentiation. After retinoic acid (RA) treatment with aggregation, expression of Evi1 was detected during neural differentiation in P19 cells. However, Evi1 was not expressed in P19 cells during mesodermal differentiation after DMSO treatment with aggregation. Enforced expression of Evi1 in P19 cells induced neuron-specific microtubule-associated protein-2 microtubule-associated protein-2 and TrkA expression in the absence of RA under monolayer culture. After incubation with RA with aggregation, the Evi1 clones expressed microtubule-associated protein-2 continuously but did not express glial fibrillary acidic protein as an astrocyte marker protein until 12 days of culture. Thus, the overexpression of Evi1 leads to neural differentiation of P19 cells and blocks further differentiation into astrocytes by RA treatment, suggesting that Evi1 might be an important transcription factor for regulation of early neuroectodermal differentiation.

Microsatellite instability in lymphoid leukemia and lymphoma cell lines but not in myeloid leukemia cell lines.

Microsatellite instability (MSI) represents a defect in the DNA mismatch repair system and has been shown to take part in the genesis and/or progression of several human malignancies. In hematological malignancies, the relevance of MSI has been a matter of controversy. Therefore, 29 microsatellite loci were examined for MSI in 57 leukemia and lymphoma cell lines by PCR analysis. Ladder formation of bands representing MSI was observed at multiple loci in 6 of 24 lymphoid leukemia/lymphoma cell lines and in 0 of 33 myeloid leukemia cell lines. Analysis for the BAT-26 and BAT-25 loci confirmed the presence of MSI in five of six lymphoid cell lines exhibiting ladder formation of bands. Thus, at least 5 out of 24 (21%) lymphoid leukemia/lymphoma cell lines were considered as being MSI-positive. These results indicate that MSI contributes to the development of lymphoid but not to myeloid malignancies.

Production of amyloid beta protein precursor as a proteinase inhibitor by human astrocytic tumors.

The production of amyloid beta protein precursor (APP), which is a potent inhibitor of matrix metalloproteinases and serine proteinases, in human astrocytic tumors (n = 17) and normal brain tissues (n = 3) was investigated. We found proteinase inhibitory activity at around 120 kD by trypsin reverse zymography in the culture media of explant cultures of anaplastic astrocytomas and glioblastomas, but not in those of astrocytomas and normal brain tissues. Immunohistochemistry using a monoclonal antibody against human APP demonstrated that APP was detectable mainly in tumor and endothelial cells. Semiquantative analysis of western blotting revealed that immunoreactivity for APP in the culture media of tumor explant cultures appeared to be increased associated with the malignancy of astrocytic tumors. These findings suggest that APP production may be related to the malignant progression of human astrocytic tumors.

Nutrient removal and starch production through cultivation of Wolffia arrhiza.

Wolffia arrhiza, a small weed found mostly in tropical and subtropical water environments, exhibits a high growth rate and consequently absorbs large amounts of nitrogen and phosphorus. Its vegetative frond contains 40% protein on a dry weight basis and its turion, which is the dormant form, has a similar starch content. The applicability of this weed to nutrient removal from secondary-treated waste water combined with starch resource production was evaluated. The nitrogen and phosphorus removal capabilities of the vegetative frond and the optimal conditions for inducing of the formation of turions from harvested biomass of vegetative fronds for the production of starch were investigated using artificial nutrient solutions. The vegetative frond showed high contents of nitrogen (6-7% of the total dry weight) and phosphorus (1-2% of the total dry weight). The nutrient removal rates of the vegetative frond were estimated to be 126 mg-N/m(2)/d and 38 mg-P/m(2)/d under a continuous flow condition. For turion formation from the vegetative fronds, a low nutrient concentration and a high plant density were most effective. Under the optimum conditions, the starch production rate was estimated to be 6 g-starch/m(2) (nutrient removal tank)/d.

J-104,871, a novel farnesyltransferase inhibitor, blocks Ras farnesylation in vivo in a farnesyl pyrophosphate-competitive manner.

Farnesylation of the activated ras oncogene product by protein farnesyltransferase (FTase) is a critical step for its oncogenic function. Because squalene synthase and FTase recruit farnesyl pyrophosphate as a common substrate, we modified squalene synthase (SS) inhibitors to develop FTase inhibitors. Among the compounds tested, a novel FTase inhibitor termed J-104,871 inhibited rat brain FTase with an IC50 of 3.9 nM in the presence of 0.6 microM farnesyl pyrophosphate (FPP), whereas it scarcely inhibited rat brain protein geranylgeranyltransferase-I or SS. The in vitro inhibition of rat brain FTase by J-104,871 depends on the FPP concentration but not on the concentration of Ras peptide. Thus, in vitro studies strongly suggest that J-series compounds have an FPP-competitive nature. J-104,871 also inhibited Ras processing in activated H-ras-transformed NIH3T3 cells with an IC50 value of 3.1 microM. We tested the effects of lovastatin and zaragozic acid A, which modify cellular FPP levels, on Ras processing of J-104,871. Lovastatin, a hepatic hydroxymenthyl coenzyme A reductase inhibitor that reduced the cellular FPP pool, increased the activity of J-104,871, whereas 3 microM zaragozic acid A, an SS inhibitor that raised the FPP level, completely abrogated the activity of J-104,871 even at 100 microM. These results suggest that J-104,871 inhibits FTase in an FPP-competitive manner in whole cells as well as in the in vitro system. Furthermore, J-104,871 suppressed tumor growth in nude mice transplanted with activated H-ras-transformed NIH3T3 cells.

Long-term evaluation of reconstruction of the sellar floor with a silicone plate in transsphenoidal surgery.

OBJECT: The authors have used a silicone plate for reconstruction of the sellar floor during rhinoseptoplastic transsphenoidal surgery because it has greater elasticity and is easier to carve than nasal septal cartilage and sphenoid sinus bone. This study was designed to evaluate the usefulness of this technique based on the authors' experience during the past 7.6 years. METHODS: A silicone plate was used to reconstruct the sellar floor in 69 consecutive patients with sellar tumors that included 60 pituitary adenomas and nine Rathke's cleft cysts. The patients ranged in age from 16 to 82 years (mean 52 years). The postoperative position of the silicone plate could be clearly identified on sagittal or coronal magnetic resonance (MR) imaging as a very low intensity plate (void signal). No displacement or migration of the implanted silicone plate was observed on follow-up MR imaging in any patient. Infections of the lesion such as a pituitary abscess were not observed clinically or radiologically in any patient. Of the 16 patients with intraoperative cerebrospinal fluid (CSF) leakage, only one patient who had a ghost sella developed postoperative CSF rhinorrhea. In all seven patients who underwent repeated surgery for residual or recurrent tumor, the silicone plate that had been placed at the initial procedure was covered with a relatively thin fibrous capsule and the plate was well preserved. The silicone plate was easily removed at reoperation and was useful for detection of the sellar floor window made previously. CONCLUSIONS: These results indicate that a silicone plate can be useful for reconstruction of the sellar floor in rhinoseptoplastic transsphenoidal surgery.