Electron-transfer-mediated decay and interatomic Coulombic decay from the triply ionized states in argon dimers

We report the first observation of electron-transfer-mediated decay (ETMD) and interatomic Coulombic decay (ICD) from the triply charged states with an inner-valence vacancy, using the Ar dimer as an example. These ETMD and ICD processes, which lead to fragmentation of Ar(3+)-Ar into Ar(2+)-Ar(2+) and Ar(3+)-Ar+, respectively, are unambiguously identified by electron-ion-ion coincidence spectroscopy in which the kinetic energy of the ETMD or ICD electron and the kinetic energy release between the two fragment ions are measured in coincidence.

The prognostic impact and stability of Isocitrate dehydrogenase 2 mutation in adult patients with acute myeloid leukemia

Although the clinical features of the Isocitrate dehydrogenase 2 (IDH2) mutation in acute myeloid leukemia (AML) have been characterized, its prognostic significance remains controversial and its stability has not been investigated. We analyzed 446 adults with primary non-M3 AML and found IDH2 R172, R140 and IDH1 R132 mutations occurred at a frequency of 2.9, 9.2 and 6.1%, respectively. Compared with wild-type IDH2, mutation of IDH2 was associated with higher platelet counts, intermediate-risk or normal karyotype and isolated +8, but was inversely correlated with expression of HLA-DR, CD34, CD15, CD7 and CD56, and was mutually exclusive with WT1 mutation and chromosomal translocations involving core-binding factors. All these correlations became stronger when IDH1 and IDH2 mutations were considered together. Multivariate analysis revealed IDH2 mutation as an independent favorable prognostic factor. IDH2(-)/FLT3-ITD(+) genotype conferred especially negative impact on survival. Compared with IDH2 R140 mutation, IDH2 R172 mutation was associated with younger age, lower white blood cell count and lactate dehydrogenase level, and was mutually exclusive with NPM1 mutation. Serial analyses of IDH2 mutations at both diagnosis and relapse in 121 patients confirmed high stability of IDH2 mutations. In conclusion, IDH2 mutation is a stable marker during disease evolution and confers favorable prognosis.

Erythropoietin promotes spinal cord-derived neural progenitor cell proliferation by regulating cell cycle

Erythropoietin (EPO) regulates the proliferation and differentiation of erythroid cells by binding to its specific transmembrane receptor (EPOR). The presence of EPO and its receptor in the CNS suggests a different function for EPO other than erythropoiesis. The purpose of the present study was to examine EPOR expression and the role of EPO in the proliferation of neonatal spinal cord-derived neural progenitor cells. The effect of EPO on cell cycle progression was also examined, as well as the signaling cascades involved in this process. Our results showed that EPOR was present in the neural progenitor cells and EPO significantly enhanced their proliferation. Cell cycle analysis of EPO-treated neural progenitor cells indicated a reduced percentage of cells in G0/G1 phase, whereas the cell proliferation index (S phase plus G2/M phase) was increased. EPO also increased the proportion of 5-bromo-2-deoxyuridine (BrdU)-positive cells. With respect to the cell cycle signaling, we examined the cyclin-dependent kinases D1, D2 and E, and cyclin-dependent kinase inhibitors, p21cip1, p27kip1 and p57kip2. No significant differences were observed in the expression of these transcripts after EPO administration. Interestingly, the anti-apoptotic factors, mcl-1 and bcl-2 were significantly increased twofold. Moreover, these specific effects of EPO were eliminated by incubation of the progenitor cells with anti-EPO neutralizing antibody. Those observations suggested that EPO may play a role in normal spinal cord development by regulating cell proliferation and apoptosis.

Abnormalities of 53BP1 in Basal-Like Breast Cancer

Background: Abnormalities in the DNA repair mechanism have been proposed to play a central role in the development of breast cancers. However the specific mechanism underlying DNA repair defects in sporadic breast cancer are mostly unknown. As 53BP1 plays a critical role in DNA repair response and has been identified as a potential tumor suppressor, its expression in basal-like breast cancer cell lines and clinical samples was investigated.Experimental Design: mRNA expression of 53BP1 was investigated in publicly available gene expression data sets. Protein expression of 53BP1 was evaluated in a large set of clinically annotated breast cancer specimens by immunohistochemistry. Analysis of 53BP1 and related proteins was performed in a set of human and mouse breast cancer cell lines.Results: Gene expression analysis demonstrated that a subset of basal-like breast cancer had decreased expression of 53BP1. Analysis of over 400 breast cancers in a tissue microarray showed that loss of 53BP1 staining was almost exclusively found in tumors that lacked ER, PR and HER2 expression; this "triple-negative" phenotype is characteristic of BLC. Approximately 42% of "triple-negative" breast cancers have abnormally low levels of 53BP1, while <2% of tumor that express either ER or HER2 lack 53BP1 expression. Tumors that have low 53BP1 expression are associated with worse distant metastasis free survival when compared to tumors with normal 53BP1 expression. A set of breast cancer cell lines with abnormal 53BP1 expression was also identified. 53BP1 abnormalities were present in some tumors and cell lines with known BRCA1 mutations.Discussion: These data suggest that a subset of basal-like breast cancers lack normal 53BP1 expression and imply that these tumors may have profound defects in DNA repair/check point function that could be exploited therapeutically. As 53BP1 abnormalities were found in some tumors with known BRCA1 mutations, this suggests that loss of 53BP1 may cooperate with abnormalities in the BRCA1-related DNA repair pathways in the pathogenesis of basal-like breast cancers. Data regarding the molecular mechanisms underlying 53BP1 abnormalities in breast cancer cell lines and samples will be presented.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1122.

Post-Neoadjuvant Chemotherapy Sentinel Lymph Node Biopsy Is Reliable in Breast Cancer: A Prospective Study in Chinese Patients

Background: Sentinel lymph node biopsy (SLNB) for breast cancer patients before chemotherapy is currently being practiced in a world wide scale. However, obvious disadvantage of a second surgical procedure after neoadjuvant chemotherapy (NAC) has been noted. Considering that metastasis in axillary lymph node would probably be eradicated by NAC making axillary lymph node dissection (ALND) completely unnecessary, SLNB performed after NAC could be a choice. Nonetheless, it is still controversial for a fear of impaired detection rate and accuracy. Therefore we carried out a prospective study by one single surgical team to compare SLNB between post-NAC patients and non-NAC patients.Methods: Operable invasive breast cancer patients confirmed by core needle biopsy before treatment with clinical N0 or N1 axilla were enrolled. Exclusion criteria included noninfiltrating cancer, inflammatory carcinoma and clinically fixed axillary lymph node. SLNB followed by ALND was performed in one single operation by the same surgical team for all patients either afer NAC or without NAC. Single methylene blue was used for SLN tracing with 2ml injected subcutaneously into the areola area and the mapping procedure was started 5 minutes later. SLN and ALND specimens were examined by 2 independent pathologists under standard pathological procedures.Results: From Dec 2007 to May 2009, 50 patients without NAC and 49 patients after NAC were prospectively enrolled. SLNB and ALND were performed as scheduled. In the post-NAC group, 19 had clinical N0 axilla and 30 had N1 axilla before treatment. SLNB was successful in 46 patients with 1.6 SLNs detected on average (range 1 to 5) and the average number of lymph nodes taken out in ALND was 15.4 (range 7 to 33). We found 9 with SLN(+)/ALN(+), 5 with SLN(+)/ALN(-), 2 with SLN(-)/ALN(+), and 29 with SLN(-)/ALN(-). In the non-NAC group, 40 had clinical N0 axilla and 10 had N1 axilla before surgery. SLNB was successful in 48 patients with 1.7 SLNs detected on average (range 1 to 6) and the average number of lymph nodes taken out in ALND was 16.8 (range 8 to 38). We found 4 with SLN(+)/ALN(+), 10 with SLN(+)/ALN(-), 1 with SLN(-)/ALN(+), and 33 with SLN(-)/ALN(-). Detection rate, accuracy, and false negative rate was 93.9% (46 of 49), 95.7% (44 of 46) and 11.8% (2 of 17) in post-NAC group and 96% (48 of 50), 97.9% (44 of 46) and 6.7% (1 of 15) in non-NAC group, respectively. There was no statistical difference between post-NAC group and non-NAC group in either detection rate (p=0.409), accuracy (p=0.525) or false negative rate (p=0.548).Conclusions: This prospective study in Chinese breast cancer population shows that post-NAC SLNB has both satisfactory detection rate and accuracy with acceptable false negative rate, being comparable to non-NAC patients. Our results also showed that using methylene blue only in SLNB for breast cancer is an ideal choice where radio detection method is not available.Summary of pathological resultsGrouppost-NAC (N=49)non-NAC (N=50)SLNB successful4648Average SLNs detected1.6 (range 1 to 5)1.7 ( range 1 to 6)Average ALNs taken out15.4 (range 7 to 33)16.8 (range 8 to 38)SLN+ / ALN-94SLN+/ ALN+510SLN- / ALN+21SLN- / ALN-2933 

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1014.

In vitro characterization and pharmacokinetics of dapagliflozin (BMS-512148), a potent sodium-glucose cotransporter type II inhibitor, in animals and humans

(2S,3R,4R,5S,6R)-2-(3-(4-Ethoxybenzyl)-4-chlorophenyl)-6-hydroxymethyl-tetrahydro-2H-pyran-3,4,5-triol (dapagliflozin; BMS-512148) is a potent sodium-glucose cotransporter type II inhibitor in animals and humans and is currently under development for the treatment of type 2 diabetes. The preclinical characterization of dapagliflozin, to allow compound selection and prediction of pharmacological and dispositional behavior in the clinic, involved Caco-2 cell permeability studies, cytochrome P450 (P450) inhibition and induction studies, P450 reaction phenotyping, metabolite identification in hepatocytes, and pharmacokinetics in rats, dogs, and monkeys. Dapagliflozin was found to have good permeability across Caco-2 cell membranes. It was found to be a substrate for P-glycoprotein (P-gp) but not a significant P-gp inhibitor. Dapagliflozin was not found to be an inhibitor or an inducer of human P450 enzymes. The in vitro metabolic profiles of dapagliflozin after incubation with hepatocytes from mice, rats, dogs, monkeys, and humans were qualitatively similar. Rat hepatocyte incubations showed the highest turnover, and dapagliflozin was most stable in human hepatocytes. Prominent in vitro metabolic pathways observed were glucuronidation, hydroxylation, and O-deethylation. Pharmacokinetic parameters for dapagliflozin in preclinical species revealed a compound with adequate oral exposure, clearance, and elimination half-life, consistent with the potential for single daily dosing in humans. The pharmacokinetics in humans after a single dose of 50 mg of [(14)C]dapagliflozin showed good exposure, low clearance, adequate half-life, and no metabolites with significant pharmacological activity or toxicological concern.

Association of Collagen Type I α1 (COLIA1) Sp1 Polymorphism with Osteoporotic Fracture in Caucasian Post-menopausal Women: a Meta-analysis

This study was designed to summarize quantitatively the evidence for a relationship between collagen type I α1 (COLIA1) Sp1 polymorphism and osteoporotic fracture risk in Caucasian post-menopausal women. This meta-analysis included 16 studies, which analysed 2294 patients with fractures and 10285 controls. The combined results showed that there was a significant difference in genotype distribution (SS odds ratio [OR] 0.72; Ss OR 1.18; ss OR 1.97) between patients with fractures and controls. When stratifying by the fracture site, it was found that: (i) patients with vertebral fractures had a significantly higher frequency of the Ss genotype and a lower frequency of the SS genotype than controls; and (ii) patients with non-vertebral fractures had a significantly higher frequency of the ss genotype and a lower frequency of the SS genotype than controls. This meta-analysis suggests that the COLIA1 Sp1 polymorphism may be associated with osteoporotic fracture in Caucasian post-menopausal women.

REP-PCR tracking of the origin and spread of airborne Staphylococcus aureus in and around chicken house

Staphylococcus aureus was used as an indicator to study the origin and spread of microbial aerosol in and around chicken houses. Air samples indoor, upwind (10 and 50 m), and downwind (10, 50, 100, 200, and 400 m) of four chicken houses were collected using Andersen-6 stages sampler. The concentrations of S. aureus were determined for every sample site. Isolation of S. aureus from chicken feces was performed according to the standard method. The genetic relationship among the isolates was determined by profiles of PCR-amplified repetitive extragenic palindromic (REP-PCR) elements. The results showed that the concentrations of S. aureus indoor of four chicken houses were higher than those upwind and downwind sites (P < 0.05 or P < 0.01), but there were no significant concentration differences among downwind sites (P > 0.05). The fingerprints and the phylogenetic tree indicated that a part of the S. aureus (55.6%, 10/18) isolates from indoor air had the same REP-PCR fingerprints as feces isolates. Consequently, most isolates (57.1%, 20/35) from downwind 10, 50, 100, 200, even 400 m had the same REP-PCR fingerprints as those from indoor or feces. These data indicated that some isolates from downwind and indoor originated from the chicken feces. However, those isolates from upwind had low similarity (similarity index 0.6-0.87) to those from indoor or feces. Therefore, the isolates upwind were not from the chicken feces or indoor. These results suggest that microbes in chicken feces can be aerosolized and spread indoor and outdoor, especially to downwind of the chicken houses. It should have an important epidemiological and public health significance.

PRACTICAL IMPLICATIONS

Thus, the use of S. aureus as an indicator to study the origin and spread of airborne pathogens from chicken houses is potentially useful for enhancing public health and understanding the airborne epidemiology of this pathogen. Meanwhile it can provide evidence for studying the spreading model of airborne pathogens.

First Report of Tobacco mosaic virus in Abutilon theophrasti in China

Velvetleaf (Abutilon theophrasti Medic), a tall, fecund, self-fertile annual plant in the family Malvaceae, is widely grown in China as a fiber crop and for its medicinal properties. In July of 2008, we observed diffuse chlorotic and necrotic spots on the oldest leaves of velvetleaf plants in the field in Shanxi Province. Sap extracts from six symptomatic plants were tested by direct antigen coated ELISA using polyclonal antibodies specific to Potato virus Y (PVY) and monoclonal antibodies specific to Tomato mosaic virus (ToMV), Cucumber mosaic virus (CMV), and Tobacco mosaic virus (TMV). Five of the six samples were negative for ToMV, CMV, and PVY but positive for TMV. Double-stranded RNA extracted from leaves of the five velvetleaf plants was used as template for reverse transcription (RT)-PCR as described by Krajačića et al. (1) and Li et al. (2) with some modifications. One-step RT-PCR was performed using a Quant One Step RT-PCR Kit (TIANGEN BIOTECH CO., LTD., Beijing, China) with sense (5'-CTGTTTAGCCGGTTTGGT-3'), and antisense (5'-TCCCTTTACGGACATCAC-3') primers (3) designed to specifically amplify a fragment of the movement protein coding region of TMV. The expected 470-bp fragments were amplified from dsRNA from these five plants and the amplicon from each plant was cloned and sequenced (GenBank Accession No. FJ873800). Comparisons of a consensus sequence derived from the five amplicons with the nucleotide sequences available in the NCBI database using BLAST showed 99% identity with TMV from South Korea (GenBank Accession No. AB354955) and Spain (Accession No. AJ308692) and 98% with TMV from China (Accession No. AF165190). The serological, RT-PCR results and sequence data revealed that these velvetleaf plants were infected by TMV. On the basis of the serological analysis and genome sequence comparisons, this isolate was tentatively designated as TMV-Velvetleaf. To our knowledge, this is the first report of TMV in Abutilon theophrasti Medic in China. References: (1) M. Krajačić et al. J. Chromatogr A. 1144:111, 2007. (2) H. Li et al. Agric. Sci. Chin. 6:86, 2007. (3) Y. B. Niu et al. Chin. Biotechnol. 29:76, 2009.

Granulocyte-macrophage colony-stimulating factor enhances wound healing in diabetes via upregulation of proinflammatory cytokines

BACKGROUND

Chronic ulceration, especially in diabetes, remains a substantial clinical problem. Exogenous granulocyte-macrophage colony-stimulating factor (GM-CSF) is efficacious in the treatment of chronic wound healing in both animal models and patients, but its role in diabetic wounds remains to be explored. Objectives Using a diabetic mouse model, to investigate the role of GM-CSF in wound healing.

METHODS

Clinical observation, histopathology, immunohistochemistry and cytokine assays.

RESULTS

There was a significant reduction (50%) in GM-CSF production in the wounds of the diabetics compared with nondiabetics. Exogenous GM-CSF substantially enhanced the wound healing in diabetic mice, accompanied by increased interleukin-6 and monocyte chemoattractant protein-1 production. The elevated cytokines correlated with increased neovascularization, and infiltration of macrophages and neutrophils. GM-CSF showed no beneficial effects in nondiabetic wound healing.

CONCLUSIONS

Our results provide useful guidelines for the clinical management of chronic ulceration in diabetes.

Studies on the pharmacokinetics and metabolism of a gamma-secretase inhibitor BMS-299897, and exploratory investigation of CYP enzyme induction

BMS-299897 is a gamma-secretase inhibitor that was effective in reducing amyloid beta-peptide (A beta) in transgenic mice and guinea pigs. Therefore, pharmacokinetic and drug metabolism studies were conducted in animals to support its clinical development. The compound appeared to have low to intermediate total body clearance and was orally bioavailable (24-100%). The oral absorption of BMS-299897 from solid dosage forms appeared to be dissolution rate-limited. BMS-299897 was distributed into extravascular space (V(ss) >or= 1.3 l kg(-1)), including brain (brain-to-plasma ratio = 0.13-0.50). BMS-299897 appeared to be a P-glycoprotein (P-gp) substrate as the brain-to-plasma ratio was two-fold higher in the mdr1a knockout mouse as compared with the wild-type. Apparent autoinduction by BMS-299897 was observed in murine and rat efficacy and toxicity studies. In vitro, BMS-299897 was a weaker inducer of cytochrome P450 3A4 (CYP3A4) and a weaker transactivator of human pregnane X receptor (hPXR) as compared with rifampicin. Induction of human UGT1A and UGT2B was evaluated in primary human hepatocytes, but the results were inconclusive. A low potential for autoinduction in humans was predicted at a clinical dose of 250 mg and the prediction was consistent with the findings from a clinical multiple-dose study with BMS-299897 in probable Alzheimer's patients.