Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Evidence for the direct two-photon transition from ψ(3686) to J/ψ

The two-photon transition ψ(3686)→γγJ/ψ is studied in a sample of 1.06×10(8) ψ(3686) decays collected by the BESIII detector. The branching fraction is measured to be (3.1±0.6(stat)(-1.0)(+0.8)(syst))×10(-4) using J/ψ→e(+)e(-) and J/ψ→μ(+)μ(-) decays, and its upper limit is estimated to be 4.5×10(-4) at the 90% confidence level. This work represents the first measurement of a two-photon transition among charmonium states. The orientation of the ψ(3686) decay plane and the J/ψ polarization in this decay are also studied. In addition, the product branching fractions of sequential E1 transitions ψ(3686)→γχ(cJ) and χ(cJ)→γJ/ψ(J=0,1,2) are reported.

First observation of the M1 transition ψ(3686)→γη(c)(2S)

Using a sample of 106×10(6) ψ(3686) events collected with the BESIII detector at the BEPCII storage ring, we have made the first measurement of the M1 transition between the radially excited charmonium S-wave spin-triplet and the radially excited S-wave spin-singlet states: ψ(3686)→γη(c)(2S). Analyses of the processes ψ(3686)→γη(c)(2S) with η(c)(2S)→K(S)(0)K(±)π(∓) and K(+)K(-)π(0) give an η(c)(2S) signal with a statistical significance of greater than 10 standard deviations under a wide range of assumptions about the signal and background properties. The data are used to obtain measurements of the η(c)(2S) mass (M(η(c)(2S))=3637.6±2.9(stat)±1.6(syst) MeV/c(2)), width (Γ(η(c)(2S))=16.9±6.4(stat)±4.8(syst) MeV), and the product branching-fraction (B(ψ(3686)→γη(c)(2S))×B(η(c)(2S)→KKπ)=(1.30±0.20(stat)±0.30(syst))×10(-5)). Combining our result with a BABAR measurement of B(η(c)(2S)→KKπ), we find the branching fraction of the M1 transition to be B(ψ(3686)→γη(c)(2S))=(6.8±1.1(stat)±4.5(syst))×10(-4).

Measurements of the mass and width of the η(c) using the decay ψ(3686)→γη(c)

The mass and width of the lowest-lying S-wave spin singlet charmonium state, the η(c), are measured using a data sample of 1.06×10(8) ψ(3686) decays collected with the BESIII detector at the BEPCII storage ring. We use a model that incorporates full interference between the signal reaction, ψ(3686)→γη(c), and a nonresonant radiative background to describe the line shape of the η(c) successfully. We measure the η(c) mass to be 2984.3±0.6±0.6 MeV/c(2) and the total width to be 32.0±1.2±1.0 MeV, where the first errors are statistical and the second are systematic.

First observation of η(1405) decays into f(0)(980)π0

The decays J/ψ → γ π+ π- π0 and J/ψ → γ π0 π0 π0 are analyzed using a sample of 225×10(6) J/ψ events collected with the BESIII detector. The decay of η(1405) → f(0)(980)π0 with a large isospin violation is observed for the first time. The width of the f(0)(980) observed in the dipion mass spectra is anomalously narrower than the world average. Decay rates for three-pion decays of the η' are also measured precisely.

Spin-parity analysis of pp¯ mass threshold structure in J/ψ and ψ(3686) radiative decays

A partial wave analysis of the pp¯ mass-threshold enhancement in the reaction J/ψ→γpp¯ is used to determine its J(PC) quantum numbers to be 0(-+), its peak mass to be below threshold at M=1832(-5)(+19)(stat)(-17)(+18)(syst)±19(model) MeV/c(2), and its total width to be Γ<76 MeV/c(2) at the 90% C.L. The product of branching ratios is measured to be BR[J/ψ→γX(pp¯)]BR[X(pp¯)→pp¯]=[9.0(-1.1)(+0.4)(stat)(-5.0)(+1.5)(syst)±2.3(model)]×10(-5). A similar analysis performed on ψ(3686)→γpp¯ decays shows, for the first time, the presence of a corresponding enhancement with a production rate relative to that for J/ψ decays of R=[5.08(-0.45)(+0.71)(stat)(-3.58)(+0.67)(syst)±0.12(model)]%.

ηπ+ π- resonant structure around 1.8 GeV/c(2) and η(1405) in J/ψ → ωηπ+ π-

We present results of a study of the decay J/ψ → ωηπ+ π- using a sample of (225.2 ± 2.8) × 10(6) J/ψ events collected by the BESIII detector, and report the observation of a new process J/ψ → ωX(1870) with a statistical significance of 7.2σ, in which X(1870) decays to a(0)(±)(980)π±. Fitting to ηπ+ π- mass spectrum yields a mass M = 1877.3 ± 6.3(stat)(-7.4)(+3.4)(syst) MeV/c(2), a width Γ = 57 ± 12(stat)(-4)(+19)(syst) MeV/c(2), and a product branching fraction B(J/ψ → ωX) × B(X→a(0)(±)(980)π±) × B(a(0) (±)(980) → ηπ±) = [1.50 ± 0.26(stat)(-0.36)(+0.72) (syst)] × 10(-4). Signals for J/ψ → ωf(1)(1285) and J/ψ → ω η(1405) are also clearly observed and measured.

Observation of χ(c1) decays into vector meson pairs φφ, ωω, and ωφ

Using (106±4)×10⁻⁶ ψ(3686) events accumulated with the BESIII detector at the BEPCII e⁺e⁻ collider, we present the first measurement of decays of χ(c1) to vector meson pairs φφ, ωω, and ωφ. The branching fractions are measured to be (4.4±0.3±0.5)×10⁻⁴, (6.0±0.3±0.7)×10⁻⁴, and (2.2±0.6±0.2)×10⁻⁵, for χ(c1)→φφ, ωω, and ωφ, respectively, which indicates that the hadron helicity selection rule is significantly violated in χ(cJ) decays. In addition, the measurement of χ(cJ)→ωφ provides the first indication of the rate of doubly OZI-suppressed χ(cJ) decay. Finally, we present improved measurements for the branching fractions of χ(c0) and χ(c2) to vector meson pairs.

Confirmation of the X(1835) and observation of the resonances X(2120) and X(2370) in J/ψ→γπ+π-η'

With a sample of (225.2±2.8)×10(6) J/ψ events registered in the BESIII detector, J/ψ→γπ(+)π(-)η(') is studied using two η(') decay modes: η(')→π(+)π(-)η and η(')→γρ(0). The X(1835), which was previously observed by BESII, is confirmed with a statistical significance that is larger than 20σ. In addition, in the π(+)π(-)η(') invariant-mass spectrum, the X(2120) and the X(2370), are observed with statistical significances larger than 7.2σ and 6.4σ, respectively. For the X(1835), the angular distribution of the radiative photon is consistent with expectations for a pseudoscalar.

Evidence for ψ' decays into γπ0 and γη

The decays ψ'→γπ(0), γη and γη' are studied using data collected with the BESIII detector at the BEPCII e(+)e(-) collider. The processes ψ'→γπ(0) and ψ'→γη are observed for the first time with signal significances of 4.6σ and 4.3σ, respectively. The branching fractions are determined to be B(ψ'→γπ(0))=(1.58±0.40±0.13)×10(-6), B(ψ'→γη)=(1.38±0.48±0.09)×10(-6), and B(ψ'→γη')=(126±3±8)×10(-6), where the first errors are statistical and the second ones systematic.

A novel HER2-positive breast cancer phenotype arising from germline TP53 mutations

INTRODUCTION

The Li-Fraumeni Syndrome is caused by a germline TP53 mutation and is associated with a high risk of breast cancer at young ages. Basal (triple negative) breast cancers are now well recognised to be a typical sub-type of breast cancer developing in a large proportion of BRCA1 gene carriers. We considered whether a similar narrow sub-type of breast cancer was found in TP53 gene mutation carriers.

OBJECTIVE

A hypothesis generating study to investigate whether there are specific breast tumour characteristics associated with germline TP53 mutations.

METHODS

Pathological characteristics in 12 breast cancers arising in nine patients carrying pathogenic TP53 mutations were compared to a reference panel of 231 young onset breast tumours included in the POSH study.

RESULTS

Patients carrying a TP53 mutation showed a significantly higher likelihood of developing a breast cancer with Human Epidermal growth factor Receptor (HER2) amplification (83%) when compared to the cohort of young onset breast cancer cases (16%); ER and PR status were equivalent between groups.

CONCLUSION

These findings suggest that breast cancer developing on a background of an inherited TP53 mutation is highly likely to present with amplification of HER2.

Effects of hydrogen plasma treatment on the electrical and optical properties of ZnO films: identification of hydrogen donors in ZnO

Wurtzite ZnO has many potential applications in optoelectronic devices, and the hydrogenated ZnO exhibits excellent photoelectronic properties compared to undoped ZnO; however, the structure of H-related defects is still unclear. In this article, the effects of hydrogen-plasma treatment and subsequent annealing on the electrical and optical properties of ZnO films were investigated by a combination of Hall measurement, Raman scattering, and photoluminescence. It is found that two types of hydrogen-related defects, namely, the interstitial hydrogen located at the bond-centered (H(BC)) and the hydrogen trapped at a O vacancy (H(O)), are responsible for the n-type background conductivity of ZnO films. Besides introducing two hydrogen-related donor states, the incorporated hydrogen passivates defects at grain boundaries. With increasing annealing temperatures, the unstable H(BC) atoms gradually diffuse out of the ZnO films and part of them are converted into H(O), which gives rise to two anomalous Raman peaks at 275 and 510 cm(-1). These results help to clarify the relationship between the hydrogen-related defects in ZnO described in various studies and the free carriers that are produced by the introduction of hydrogen.

Measurements of h(c)(1P(1)) in psi' decays

We present measurements of the charmonium state h(c)(1P(1)) made with 106x10(6) psi' events collected by BESIII at BEPCII. Clear signals are observed for psi'-->pi0 h(c) with and without the subsequent radiative decay h(c)-->gamma eta(c). First measurements of the absolute branching ratios B(psi'-->pi0 h(c)) = (8.4+/-1.3+/-1.0) x 10(-4) and B(h(c)-->gamma eta(c)) = (54.3+/-6.7+/-5.2)% are presented. A statistics-limited determination of the previously unmeasured h(c) width leads to an upper limit Gamma(h(c))<1.44 MeV (90% confidence). Measurements of M(h(c)) = 3525.40+/-0.13+/-0.18 MeV/c2 and B(psi'-->pi0 h(c)) x B(h(c)-->gamma eta(c)) = (4.58+/-0.40+/-0.50) x 10(-4) are consistent with previous results.

A Novel Tumour-Based Test To Identify Breast Cancer Due to BRCA1 and BRCA2 Mutations

Background: Family history and young onset are the usual indicators of an underlying genetic predisposition to breast cancer development. BRCA1 associated breast tumours are more likely to be ER negative and express “basal” markers, however most patients with ER negative/ basal marker positive breast cancers (especially young onset) do not have inherited BRCA1 mutations. BRCA1 and BRCA2 gene carriers may have novel treatment options available and may need to consider future cancer prevention strategies. Genetic counselling and germline mutation analysis remains a relatively expensive option that is not appropriate for most breast cancer patients.Aim: To design a sensitive and specific pathology based predictor that would improve identification of BRCA1 and 2 gene carriers.Method: We assembled a training panel of breast cancer tumour blocks from 67 BRCA1, 71 BRCA2 associated and 105 sporadic young onset cases (≤ 40 years at diagnosis). All gene carriers were diagnosed before 50 years and were matched to sporadic cases for ER status. Tissue micro arrays (TMAs) were assembled and subjected to immunohistochemical analysis with a panel of 18 antibodies. DNA was extracted from micro dissected tumour tissue and matched patient lymphocytes and subjected to high resolution tiling path microarray-based Comparative Genomic Hybridisation (aCGH). Using robust statistical approaches, regions significantly differentially lost, gained or amplified in BRCA1, BRCA2 and controls were identified. Probes for chromogenic in situ hybridisation (CISH) for amplified regions were generated.Results: Two differentially amplified clones in BRCA1 cases designated P1 at 3q25.31 and P2 at 3q25.2 and one in BRCA2 cases, P3 at 20q13.13, were identified and amplifications validated in the training set using CISH. Logistic regression analysis of the panel comprising CISH and IHC markers was used to develop the best predictor. The best predictor for BRCA1 gene carriers was a combination of P1, ER and HER2. This combination outperformed all combinations of immunohistochemical markers, including ER and basal markers; the Positive Predictive Value (PPV) was 87.5% and NPV 92% giving a Receiver Operator Characteristic (ROC) curve with an AUC of 0.92 (CI 0.88-0.97). The BRCA2 signature panel is currently being evaluated. These BRCA1 and BRCA2 predictor panels are being validated in a new set of TMAs comprising 223 tumours from the POSH study1.Conclusion: This tumour based predictor for BRCA1 and BRCA2 carriers may prove useful to identify gene carriers at low a priori chance of having a mutation, to direct BRCA1/2 targeted treatment approaches and to identify familial non BRCA1/2 cases that may be suitable for new gene discovery studies.1. Eccles D et al. BMC Cancer 2007; 7(1):160.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5032.

Friction models incorporating thermal effects in highly precision actuators

This paper presents two models based on the LuGre model for friction with consideration of thermal effects. In Model I, parameters in the LuGre model are considered as temperature dependent. In Model II, parameters in the LuGre model are considered as temperature independent; while a temperature-dependent function is added to the temperature-independent LuGre model. Both models are experimentally evaluated, which shows that both can effectively incorporate thermal effects but Model II has better accuracy. Since these models are developed in the context of the motion system, they should be readily incorporated in motion control algorithms for effective control of motion systems with friction if temperature rise is significant in these systems.

Disruption of ETV6 in intron 2 results in upregulatory and insertional events in childhood acute lymphoblastic leukaemia

We describe four cases of childhood B-cell progenitor acute lymphoblastic leukaemia (BCP-ALL) and one of T-cell (T-ALL) with unexpected numbers of interphase signals for ETV6 with an ETV6-RUNX1 fusion probe. Three fusion negative cases each had a telomeric part of 12p terminating within intron 2 of ETV6, attached to sequences from 5q, 7p and 7q, respectively. Two fusion positive cases, with partial insertions of ETV6 into chromosome 21, also had a breakpoint in intron 2. Fluorescence in situ hybridisation (FISH), array comparative genomic hybridization (aCGH) and Molecular Copy-Number Counting (MCC) results were concordant for the T-cell case. Sequences downstream of TLX3 on chromosome 5 were deleted, leaving the intact gene closely apposed to the first two exons of ETV6 and its upstream promoter. qRT-PCR showed a significant upregulation of TLX3. In this study we provide the first incontrovertible evidence that the upstream promoter of ETV6 attached to the first two exons of the gene was responsible for the ectopic expression of a proto-oncogene that became abnormally close as the result of deletion and translocation. We have also shown breakpoints in intron 2 of ETV6 in two cases of insertion with ETV6-RUNX1 fusion.

Constitutive expression of the nifA gene activates associative nitrogen fixation of Enterobacter gergoviae 57-7, an opportunistic endophytic diazotroph

AIMS

This study was undertaken to investigate whether a nitrogen-fixing bacterium Enterobacter gergoviae 57-7, which was isolated from surface-sterilized maize (Zea mays L.) roots, can colonize in roots and whether constitutive expression of the nifA gene encoding the transcriptional activator of nitrogenase genes can activate nif gene expression in planta.

METHODS AND RESULTS

Maize seedlings grown in an agar medium were inoculated with Ent. gergoviae strains containing the green fluorescent protein reporter gene. Root colonization and expression of the dinitrogenase reductase gene (nifH) by Ent. gergoviae were observed by confocal laser scanning microscopy. gfp-tagged Ent. gergoviae was observed to colonize predominantly in cortical aerenchyma of primary and lateral roots and in stellar parenchyma cells and xylem vessels of primary roots. In planta nifH :: gfp expression was not detected but after a constitutively expressed nifA gene was introduced into Ent. gergoviae.

CONCLUSIONS

Enterobacter gergoviae 57-7 is an opportunistic endophyte because it can live in soil and colonize in maize roots in the gnotobiotic agar culture. In agreement with previous (15)N-dilution evidence that Ent. gergoviae 57-7 did not fix N(2) in association with maize in pots whereas a derivative E7 containing a constitutively expressed nifA gene promoted plant growth partly through associative nitrogen fixation, constitutive expression of the nifA gene can activate bacterial nif gene expression in planta.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study and our previous studies suggest that manipulation of the promoter of the nifA gene in a nitrogen-fixing bacterium having a high colonization competence is a practical and promising approach to achieve a stable associative nitrogen fixation for cereals.

Effect of site-directed PEGylation of trichosanthin on its biological activity, immunogenicity, and pharmacokinetics

Trichosanthin (TCS) is a type I ribosome-inactivating protein (RIP) with multiple biological and pharmacological activities. It has been approved effective in the clinical treatment of AIDS and tumor, but its strong immunogenicity and short plasma half-life have limited the clinical administration. To reduce the immunogenicity and prolong the plasma half-life of this compound, three TCS muteins (M(1), M(2) and M(3)) and two PEGylated TCS muteins (PM(1) and PM(2)) were constructed by site-directed mutagenesis and PEGylation, respectively. Compared with the unmodified TCS, both PEGylated TCS showed a 3- to 4-fold decrease in immunogenicity, a 0.5- to 0.8-fold decrease in non-specific toxicity, and a 4.5- to 6-fold increase in plasma half-life. But there is a problem of activity reduction. The increased circulating half-life in vivo may compensate for the reduced activity. Together with the other benefits of PEGylation such as reduced immunogenicity and toxicity, it is worthwhile to further explore the potential application of the PEGylated TCS as a better therapeutic agent for AIDS and tumor.

Results after change of treatment policy for rectal cancer – report from a single hospital in China

BACKGROUND

Great changes have occurred in the management of rectal cancer. This study presents the outcome of total mesorectal excision (TME) for rectal cancer in a single Chinese institution and evaluates TME's role in the comprehensive management of rectal cancer.

METHODS

We reviewed the data of rectal cancer patients surgically treated by three colorectal surgeons from January 2000 to August 2004. Patients who received surgical resection for rectal cancer from January 1996 to December 1999, before the introduction of TME, were chosen as controls. Data regarding characteristics of patients and tumors, surgical procedures, postoperative complications, and results of follow-up were collected for analysis.

RESULTS

Three hundred and seventy-seven patients with rectal cancer were enrolled in our study, with 175 patients in the TME group and 202 as controls. Mortality and morbidity rates were 1% and 14% in TME patients and 1% and 31% in controls, respectively. The TME group had a shorter operation time and hospital stay, and less bleeding, wound and urinary complications. The local recurrence (LR) rate was 6% and 12% in the TME and the control groups, respectively (P<0.05). With a median follow-up of 35 months, the actuarial 5-year survival rate was 66%. Consistent with the univariate analysis result, multivariate analysis demonstrated that TNM stage, tumor grade, age, and surgeons were independent prognostic factors. TME was not an independent prognostic factor for patients' survival.

CONCLUSIONS

TME is a safe and efficient option in reducing LR. However, it is not an independent predictor for patients' survival. In addition to the standardized usage of TME, further knowledge on the molecular mechanism of cancer is needed.

Mapping the antigenic determinants and reducing the immunogenicity of trichosanthin by site-directed mutagenesis

Trichosanthin (TCS) is a type I ribosome-inactivating protein (RIP) possessing multiple pharmacological properties. One of its interesting properties is to inhibit human immunodeficiency virus (HIV) replication but its strong immunogenicity has limited the repeated clinical administration. To map the antigenic determinants and reduce the immunogenicity of TCS, two potential antigenic sites (YFF81-83 and KR173-174) were identified by computer modeling, and then three TCS mutants namely TCS(YFF81-83ACS), TCS(KR173-174CG), and TCS(YFF-KR) were constructed by site-directed mutagenesis. The RI activity and DNase-like activity of the three constructed TCS mutants were similar to natural TCS but with much lower immunogenicity. Results suggested that the two selected sites are all located at or near the antigenic determinants of TCS. In toxicity studies, the LD(50) of the three TCS mutants was not different from natural TCS. These findings would be useful in designing a better therapeutic agent for AIDS.

Comparison of blood counts in splenic, renal and mesenteric arterial and venous blood in post-pubertal rabbits

OBJECTIVES

To compare blood counts between arterial and venous blood to and from visceral organs and indirectly look into the function of the organs.

METHODS

Splenic, renal and superior mesenteric arterial and venous blood samples were obtained from the arteries and veins in 38 post-pubertal rabbits and blood profile, including complete and differential blood counts, haemoglobin concentration and haematocrit, were measured with an automatic haematology analyser.

RESULTS AND CONCLUSIONS

The rabbit spleen released a large amount of leucocytes (both lymphocytes and granulocytes) into the splenic venous blood (a venous increase of 33% in total leucocyte count), and also received more leucocytes (36-58% more in terms of concentration) from the artery than the kidney or intestine. Significantly fewer red blood cells were present in the renal venous blood than in the arterial blood (a venous reduction of 5% in erythrocyte count), but it remains to be clarified why and how the reduction was induced. More than 3-4% of water might be taken into the mesenteric venous blood during microcirculation (a venous reduction of 3-4% in erythrocyte-related parameters) and a significant number of leucocytes (mainly large leucocytes) in the mesenteric blood capillaries might migrate into the surrounding intestinal tissue (a venous reduction of 13% in leucocyte count).

Residues of organochlorinated pesticides in eggs of water birds from Tai Lake in China

The levels of organochlorine compounds in eggs of water birds from the colony on Tai Lake in China were studied. The eggs were collected in 2000 and belonged to the following species: 65 samples of black-crowned night heron (Nycticorax nycticorax), 36 samples of little egret (Egretta garzetta), 26 samples of cattle egret (Bubulcus ibis) from 13 clutches and 43 samples of Chinese pond heron (Ardeola bacchus) from 17 clutches. Dichlorodiphenyltrichloroethane (DDT) and its derivates (DDE and DDD), hexachlorocyclohexane (HCH) and its isomers (alpha-HCH, beta-HCH, gamma-HCH, delta-HCH), heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, endrin aldehyde, alpha-endosulfan, beta-endosulfan, and endosulfan sulfate were determined in the laboratory by gas chromatography. The data showed that DDE had the highest levels in all the samples, followed by beta-HCH. The mean levels of DDE among the water bird species were in the order as follows: black-crowned night heron (5464.26 ng/g, dry weight) > Chinese pond heron (2791.12 ng/g, dry weight) > little egret (1979.97 ng/g, dry weight) > cattle egret (660.11 ng/g, dry weight). DDT and its metabolites accounted for 90% of the total organochlorines, except that it was only 73% for cattle egret. The differences of the residue among the bird species were statistically significant and could be attributed to their variations in prey and habitat. Although the DDE burdens in Tai Lake were much lower than 8 microg/g (wet weight) which are thought to have significant adverse effects on black-crowned night herons, they would be expected to increase the risk of adverse effects on survival of chicks of herons and egrets, particularly black-crowned night heron, based on the critical value of 1 microg/g (wet weight) DDE. The burdens of HCHs in this study were higher and the cyclodienes were lower than those found elsewhere.

Substrate induction of isomaltulose synthase in a newly isolated Klebsiella sp. LX3

AIMS

Production of isomaltulose by newly isolated Klebsiella sp. LX3.

METHODS AND RESULTS

The bacterial isolate LX3, which transforms sucrose to isomaltulose and trehalulose, has been isolated from a soil sample in Singapore. Morphological and biochemical analysis, as well as 16s rRNA sequence demonstrated that the isolate could represent a new member of genus Klebsiella. The strain has several interesting features. The immobilized cells of Klebsiella sp. LX3 convert more than 99% of sucrose to products that consist of more than 87% of isomaltulose, 11.6% of trehalulose, and <1% of glucose.

CONCLUSIONS

The production of isomaltulose synthase in isolate LX3 is inducible by its substrate sucrose and the sugars containing a fructofuranosyl group.

SIGNIFICANCE AND IMPACT OF STUDY

It would be useful for future biotechnological applications to understand the structural features or motifs of the isomaltulose synthases that determine the sucrose conversion efficiency and the ratio of the conversion products.

[Comparison of tumor suppressor gene deletion between squamous cell carcinoma and adenocarcinoma lung cancer in Chinese]

OBJECTIVE

To prove the hypothesis that there may be different tumor suppressor genes (TSGs) involved in genesis of squamous cell carcinoma (SCC) and adenocarcinoma (ADC) in non-small cell lung cancer (NSCLC) in the Chinese.

METHODS

Twenty-two microsatellite markers flanking to or within 13 identified or candidate TSGs were used to detect loss of heterozygosity (LOH) in these regions in the specimens of 28 SCC patients and 13 ADC patients.

RESULTS

Our data demonstrated frequent allelic loss of FHIT, p53, IFNA, VHL and p16 both in SCC and ADC. Three genes, PRLTS, PTEN and p57, showed statistically significant differences in the LOH frequency between SCC and ADC.

CONCLUSION

The comparison of LOH frequencies between SCC and ADC indicates possible correlation between specific tumor suppressor genes and each type of lung cancer. The results also suggest that more attention should be paid to the PRLTS gene, which may play an important role in the development of ADC.

A comparison between microsatellite analysis and cytology of urine for the detection of bladder cancer

We have studied, in a blinded fashion, cytology and microsatellite analysis on urine sediments of 143 Chinese with or without bladder lesions. Microsatellite analysis succeeded in all 143 individuals, while cytology could not be performed on 42 subjects due to insufficient urine samples. Both microsatellite analysis and routine urine cytology succeeded in 81 bladder cancer patients. Seventy-three patients (90%) were identified by microsatellite analysis, while only 41 patients (51%) were identified by cytology. However, four patients were identified by routine cytology but not by microsatellite analysis. Our results proved that microsatellite analysis is more sensitive than routine cytology but the two methods are complementary to each other.

[Loss of heterozygosity on chromosome 9p13-23 in microdissected laryngeal squamous cell carcinoma by microsatellite analysis]

OBJECTIVE

Loss of heterozygosity (LOH) studies indicate that allelic loss associated with the development of head and neck of squamous cell carcinoma occurs most frequently at 9p21-22. However, the target of chromosome 9p21-22 loss has been the source of significant debate. A putative tumor suppressor gene, p16, has been identified at the 9p21 location, but genetic alterations of p16 located in this region are unusual. To refine the hot spots of LOH on chromosome 9p13-23 will be helpful to find other putative tumor suppressor genes in laryngeal squamous cell carcinoma.

METHODS

The sections of paraffin-embedded tumor tissues were microdissected to enrich for neoplastic cells. LOH on 9p13-23 was analyzed in a set of 42 paired blood and tumor samples using polymerase chain reaction (PCR) with 13 highly polymorphic microsatellite markers.

RESULTS

Of the 42 total tumors, 41(97.6%) showed LOH in at least one of the microsatellite markers tested at the chromosome 9p13-23 region. The most frequently deleted marker was D9S162 with in 17 of 19 (89.5%) informative samples. The marker D9S171, which is located in 9p21, had LOH detected in 12 of 15 informative cases (80.0%). LOH at the D9S1748 marker (closest to the p16 gene locus) was detected in 18 of 36 informative cases (50.0%). Fine deletion mapping also revealed two minimal regions of LOH encompassing markers D9S161-D9S171 at 9p21 and IFNA-D9S162 at 9p22-23.

CONCLUSION

These findings imply the high frequency of LOH at 9p13-23 in laryngeal squamous cell carcinoma and the presence of at least two as yet unidentified tumor suppressor genes in 9p13-23 region. Those putative tumor suppressor genes may become inactivated during the progression of the laryngeal squamous cell carcinoma.

[Synthesis and characterization of meso-tetra-(4-palmitoyloxyphenyl)porphyrin]

The meso-tetra-(4-palmitoyloxyphenyl)porphyrin(TPPPH2) was synthesized by esterification reaction with meso-tetra-(4-hydroxyphenyl)porphyrin(THPPH2) and Palmityl chloride as reactant. This product was separated and purified by column chromatography with silica gel as fixed phase and chloroform as washing agent, and characterized by means of elemental analysis, UV-visible spectrum, infrared photoacoustic spectrum and 1H NMR. The main spectra of UV, IR and 1H NMR were measured and investigated.

[Abnormalities of tumor suppressor genes at chromosome 3p in lung cancer]

OBJECTIVE

To investigate the allelic loss of heterozygosity in three tumor suppressor genes, Fhit, hMLH1 and VHL, located at three corresponding regions 3p14-cen, 3p21.3-22 and 3p25-26 with a high fregnency in lung cancer and to evaluate the expression of Fhit protein in the tumor tissue of lung cancer.

METHODS

Microsatellite analysis was performed by using the primers that amplified polymorphic sequences inside or flanking to the three genes in the tumor tissues collected from 45 cases of primary lung cancer. Immunohistochemical staining was performed to detect the expression of Fhit protein in the tumor tissues from 17 out of the 45 cases.

RESULTS

For loci D3S1234, D3S1300 and D3S4103 that are located in the intron of Fhit gene, LOH was found in informative cases as 62.9%, 63.6% and 59.5%, respectively. In D3S1561 and D3S1612 that are linked with hMLH1 gene, LOH was detected in 54.5% and 63.2% of informative cases, respectively. LOH was found in 64.3% and 41.7% of informative cases, at D3S1038 and D3S1283, respectively, which are flanked to VHL gene. Expression of Fhit protein was down regulated in tumor tissues of 11 out of 17 cases (64.7%); among 10 of the 11 samples, LOH was detected at one or more of the microsatellite loci tested.

CONCLUSION

High frequency loss of one allele in tumor suppressor genes Fhit, hMLH1 and VHL was observed in the tumor tissues of lung cancer, indicating that it may play a role in carcinogenesis of human lung, and may provide some new approaches to early gene detection for lung cancer. Loss of one allele of Fhit gene may be one of the mechanisms for down regulation of Fhit protein expression in lung cancer.

[Organochlorine residues in eggs of night heron breeding in Yuantouzhu, Wuxi and their functions as bioindicator]

This study analyzed chlorinated pesticides in eggs of night heron breeding in Yuantouzhu, Tai lake. The HCH isomers, DDT, DDD, DDE, endrine and heptachlor epoxide were detected out in egg samples. The residue level and the percent of detection of beta-HCH and p,p'-DDE were significantly high. The mean value of p,p'-DDE was 0.906 microgram/g dry weight. Most of the chlorinated pesticides in samples from Wuxi were higher than those of Gongqing city, Jiangxi province. Oppositely, the hatching rate of night heron egg in Wuxi region was lower than that in Gongqing city. It may be related to the difference of DDE residual levels. Using organochlorine residue in eggs of water-fowls as an indicator for environmental quality assessment is feasible.

Detecting bladder cancer in the Chinese by microsatellite analysis: ethnic and etiologic considerations

BACKGROUND

Microsatellite analysis of urine sediments has shown promise as a highly sensitive and specific technique for the detection of bladder cancer. However, most studies have been conducted in Western countries with Caucasian subjects. We explored the potential of microsatellite analysis for detecting bladder cancer in Chinese people.

METHODS

We performed microsatellite analysis of surgical specimens and urine sediment cells collected from Chinese patients with bladder tumors. Those microsatellite markers giving clearly readable patterns and showing susceptibility to alterations were used as a panel to detect primary tumors. A blinded study of additional patients with bladder cancer was performed to investigate the practical value of this panel for detecting bladder cancer. All statistical tests were two-sided.

RESULTS

Thirty-eight bladder tumors and corresponding urine sediment specimens were initially screened for 60 microsatellite markers from 18 chromosomes. Nine markers, most of which were different from those that had been used for Western patients, with frequent alterations in the initial patients were selected for further analysis. In the subsequent blinded experiment, microsatellite alterations were observed in urine sediments from 22 (96%) of 23 patients with bladder cancer and from all three patients with inverted papilloma. None of the urine sediments from the one patient with bladder lipoma, from the one patient with neurofibroma, or from the 12 individuals without evidence of bladder tumor showed any microsatellite alterations.

CONCLUSIONS

Microsatellite analysis of urine sediments could be a practical method for detecting bladder cancer in the Chinese. Our identification of different microsatellite markers highlights possible ethnic and etiologic disparities between the Chinese and Western bladder cancer patients.

Molecular and cytogenetic alterations in early stage of carcinogenesis of human lung

In an attempt to reveal the genetic and epigenetic abnormalities in early stage of carcinogenesis of human lung cancer, a human bronchial epithelial cell line was immortalized by transfection with the Simian virus early region genes (SV40T); the biological features of the stable transfected cells were compared to human non-small cell lung cancer (NSCLC) specimens. The immortalized bronchial epithelial cells did not develop tumors but premalignant lesions in animal models. However, several genetic changes, including chromosome deletion and aneuploidy, altered expression of oncogenes and tumor suppressor genes occur not only in invasive NSCLC (human specimens) but also in the early stage of lung carcinogenesis (premalignant lesions) in this transfection model.

[Discussions on some problems related to fluid inclusion analysis by SXRF]

X-ray fluorescence experiments were carried out at Beijing Synchrotron Radiation Facilities (BSRF) using synchrotron radiation as excitation source. The samples were made by mixing national reference standard GBW07106 and certain amount of reagent NaCl and KCl, and pressed into pellets. The purpose of the experiment is to verify the detection ability of the XRF setup at BSRF for elements in geological samples, especially for light elements. The beam size was 20 x 20 microns2, and the current in the storage ring was about 40 mA. The gap between the sample and the Si(Li) detector was 2 cm. With measuring time of 200 sec., The relative and absolute detection limits for 10 elements have been calculated. The sampling depth and sampling weight, which are critical in individual fluid inclusion analysis, have also been estimated. Some problems concerning the individual fluid inclusion analysis by SXRF, such as inclusion depth determination, effect of the inclusion depth on XRF intensity etc., are discussed based on the experiment results.

[Joint effects of arsenic and lead on lipid peroxidation of human and rat erythrocytes]

The authors observed the joint effects of arsenic and lead on lipid peroxidation(LPO) in vitro and in vivo. In vitro, the authors used the extracted erythrocyte membrane of health adult men and divided them into three exposed groups. The first group was exposed to As2O3 (0, 0.4, 2.0 and 10.0 mmol/L). The second group was exposed to PbAc2 (0, 0.08, 0.4 and 2.0 mmol/L). The third group was exposed to As(10 mmol/L) + Pb (0.08 mmol/L). The results show that there is interaction between As and Pb on LPO of erythrocyte membrane. In vivo, the authors measured LPO levels of rat's plasma, blood glutathione(GSH) and superoxide dismutase(SOD) activity. By using 2 x 2 factorial design, Wistar rats were gavaged with As2O3 2.4 mg/(kg.d) and PbAc2 30 mg/(kg.d) as well as both arsenic and lead in water for 10 days. The results show that in the As-Pb treated rats, the levels of LPO did not change significantly, the GSH levels and SOD activity decreased significantly. The results of factorial analysis revealed a synergic effect of As-Pb on SOD activity.

High level expression and secretion of Fc-X fusion proteins in mammalian cells

We have developed a general expression system that enhances the production and secretion of proteins in mammalian cells. The protein of interest is expressed as a fusion to a signal peptide and the Fc fragment of immunoglobulin as the N-terminal fusion partner, which can direct the cellular processes into expressing and secreting high levels of many different types of proteins. These include secretory proteins, enzymes and soluble domains of membrane proteins, as well as nuclear and regulatory proteins. Typical expression levels of these proteins from stable cell lines ranged from several to 100 microg/ml in conditioned media. The Fc domain helps to solubilize hydrophobic proteins and provides a handle for easy detection and purification of the fusion proteins; and it can be cleaved off by treatment with protease if desired.

Rapid and sensitive detection of Chlamydia trachomatis using a ligatable binary RNA probe and Q beta replicase

A simple assay format was developed for the direct detection of C. trachomatis rRNA utilizing ligation of recombinant MDV-1 probe RNA fragments hybridized to 23S rRNA after capture and release from a solid support. Assay background (equivalent to 10(4) targets) was suppressed by blocking sequences in the 5' MDV reporter probe fragment complementary to the 3' fragment by prehybridization of a DNA oligonucleotide. A pair of reporter fragments bearing a deletion within the region, obtained by a hydrid-selection-amplification protocol, yielded a low level of assay background which was reduced to < 2% with a blocker directed against the remaining pairing sequence. This probe set showed a sensitivity of 10(3) molecules of 23S rRNA (> 95% responding) and could detect a single elementary body (EB) of Chlamydia trachomatis or 1-10 EB added to a clinical matrix of pooled negative human cervical swab samples. The time of first appearance of amplification products by real-time fluorescence detection showed a linear response to log increases in the target level over a 10(5)-fold range, permitting the determination of target level within an order of magnitude. The assay showed approximately 10(9)-fold discrimination over Chlamydia pneumonae (TWAR) rRNA. High levels of cultured C. albicans, E. coli, S. aureus, or N. gonorrhoeae had no detectable effect on assay background or the ability to detect a single elementary body.

Comparison of amplified Q beta replicase and PCR assays for detection of Mycobacterium tuberculosis

Because of the long time required to isolate Mycobacterium tuberculosis in culture, there is an acute need for simple rapid methods for direct detection of M. tuberculosis from human sputum specimens. We have developed and characterized quantitative manual Q beta replicase and PCR assays for M. tuberculosis. The Q beta replicase assay was based on reversible target capture of M. tuberculosis 23S rRNA followed by amplification of a replicatable detector probe with Q beta replicase. For PCR assays, primers generating a 370-bp amplification product from the IS6110 insertion element were used in combination with a control plasmid containing an internal deletion in the IS6110 amplicon. Serial dilutions of M. tuberculosis were spiked into sputum and subjected to digestion and decontamination with N-acetyl-L-cysteine and NaOH. Assay conditions were optimized for hybridization and sample processing chemistries in order to maximize sample utilization. Following assay optimization, the sensitivities of the Q beta replicase and PCR assays of spiked sputum samples were 0.5 and 5.0 CFU per assay reaction, respectively. The effects of sputum matrix on each assay were examined by testing 20 patient sputum samples which had been cultured for M. tuberculosis. The culture-positive samples included smear-positive and smear-negative samples. The results of the Q beta replicase assay were not inhibited by sputum and were in 100% agreement with those of culture, including detection of 10 culture-positive specimens. However, using an internal control plasmid coamplified with each PCR as an indicator, we detected PCR inhibition in 9 of 20 samples tested. Decreasing the amount of sample assayed in the PCR 24-fold alleviated the inhibitory effects in all but two specimens, one of which was culture positive. The decreased sample utilization also resulted in a false-negative result with a third specimen which was culture positive for M. tuberculosis. Quantitative smear results and QB replicase assay estimates of the number of organisms present in these specimens were in close agreement. The QB replicase assay performed well in comparison with both culture and PCR and should offer a rapid means for detecting and controlling infection due to M. tuberculosis.

Comparison of characteristics of Q beta replicase-amplified assay with competitive PCR assay for Chlamydia trachomatis

In order to study infections due to Chlamydia trachomatis, we have compared semiquantitative PCR and Q beta replicase-amplified assays for detection of this organism. The PCR assay was directed against the C. trachomatis 16S rRNA gene. Quantitation was accomplished by adding known amounts of a plasmid containing a truncated segment of the 16S rRNA gene target to chlamydia-containing samples and then amplifying with a common primer set. The Q beta replicase assay consisted of reversible target capture of C. trachomatis 16S rRNA, which was followed by amplification of an RNA detector probe in the presence of the enzyme Q beta replicase. In a clinical matrix, the lower limit of detection of both the PCR and Q beta replicase assays was five elementary bodies. The Q beta replicase and PCR assays were quantitative over 10,000- and 1,000-fold ranges of organisms, respectively. Analysis of the effects of endocervical matrix on amplification was accomplished by examining 94 endocervical specimens by each technique. Both assays detected five of six culture-confirmed specimens as well as three culture-negative specimens. PCR inhibitors were detected in 13 specimens. The Q beta replicase assay, in contrast, showed no evidence of sample inhibition. The Q beta replicase and PCR assays should allow quantitative investigation of infections due to C. trachomatis. In addition, because it targets highly labile RNA, the Q beta replicase assay may facilitate investigations into the role of active persisting infection in culture-negative inflammatory conditions.

Molecular cloning and nucleic acid sequencing of Chlamydia trachomatis 16S rRNA genes from patient samples lacking the cryptic plasmid

We have examined the relationship between Chlamydia trachomatis found in clinical samples in which the cryptic plasmid was absent and known serovars of C. trachomatis. PCR and RNase protection assays were used to compare 12 C. trachomatis serovars and a plasmidless L2 serovar strain with the reactivity of clinical specimens taken from patients with pelvic inflammatory disease (PID) containing the C. trachomatis 16S rRNA gene and 16S rRNA but lacking plasmid DNA. Serovars D, E, H and I were unreactive in either or both of the PCR and RNase protection assays. The plasmidless L2 strain had reactivities indistinguishable from the nucleic acids found in the PID clinical specimens. Serovar D, the plasmidless L2 strain, and nucleic acids from two of the PID specimens were further compared by amplifying, cloning and sequencing the 16S rRNA genes detected in these samples. The sequences of the 16S rRNA genes detected in the PID clinical samples and the 16S rRNA gene of the plasmidless C. trachomatis variant were indistinguishable from previously reported sequences of the C. trachomatis 16S rRNA. Serovar D showed five base changes over the same region. We conclude that although these clinical samples lack the C. trachomatis cryptic plasmid, they do contain C. trachomatis nucleic acid.

Molecular cloning of chick cardiac muscle tensin. Full-length cDNA sequence, expression, and characterization

Here we describe the molecular cloning of 7.1-kilobase cDNA encoding chick cardiac muscle tensin. It contains an open reading frame of 1,744 amino acid (aa) residues. Sequence analysis reveals that, in addition to the previously noted SH2 domain (Davis, S., Lu, M. L., Lo, S. H., Lin, S., Butler, J. A., Druker, B. J., Roberts, T. M., An, Q., and Chen, L. B. (1991) Science 252, 712-715), tensin contains virtually all of the known sequence (362 aa) of insertin, an actin-capping protein that allows actin monomer to be "inserted" (Schroer, E., and Wegner, A. (1985) Eur. J. Biochem. 153, 515-520). Moreover, tensin shares partial homology with actin (46.7% identity in 30 aa), beta-spectrin's actin-binding consensus (40% identity in 26 aa), BCR (40% identity in 25 aa), catenin alpha (35% identity in 45 aa), synapsin Ia (25.6% identity in 156 aa), IL-3 receptor (20.2% identity in 384 aa), and IL-2/EPO receptors (14% identity in 20 aa). Recombinant full-length tensin, tagged with an influenza-derived epitope, was over-expressed by a baculovirus system and purified to apparent homogeneity. It migrates as a 200-kDa protein in SDS-polyacrylamide gel electrophoresis, similar to the native tensin. The structure of the tensin molecule has been characterized by light scattering, electron microscopy, and gel filtration. Nine monoclonal antibodies recognizing different regions of tensin have been prepared and characterized. The epitope-tagged recombinant tensin gene was subcloned into a pRcCMV vector and transfected into NIH 3T3 cells. Immunofluorescence stainings with monoclonal antibodies specific for chick tensin (not cross-reactive with mouse tensin) showed that the expressed protein is indeed localized at focal contacts, as that of native tensin.