HER2, MET and FGFR2 oncogenic driver alterations define distinct molecular segments for targeted therapies in gastric carcinoma

Background:

Gastric cancer (GC) is a leading cause of cancer deaths worldwide. Since the approval of trastuzumab, targeted therapies are emerging as promising treatment options for the disease. This study aimed to explore the molecular segmentation of several known therapeutics targets, human epidermal growth factor receptor 2 (HER2), MET and fibroblast growth factor receptor 2 (FGFR2), within GC using clinically approved or investigational kits and scoring criteria. Knowledge of how these markers are segmented in the same cohort of GC patients could improve future clinical trial designs.

Methods:

Using immunohistochemistry (IHC) and FISH methods, overexpression and amplification of HER2, FGFR2 and MET were profiled in a cohort of Chinese GC samples. The correlations between anti-tumour sensitivity and the molecular segments of HER2, MET and FGFR2 alterations were further tested in a panel of GC cell lines and the patient-derived GC xenograft (PDGCX) model using the targeted inhibitors.

Results:

Of 172 GC patients, positivity for HER2, MET and FGFR2 alternations was found in 23 (13.4%), 21 (12.2%) and 9 (5.2%) patients, respectively. Positivity for MET was found in 3 of 23 HER2-positive GC patients. Co-positivity for FGFR2 and MET was found in 1 GC patient, and amplification of the two genes was found in different tumour cells. Our study in a panel of GC cell lines showed that in most cell lines, amplification or high expression of a particular molecular marker was mutually exclusive and in vitro sensitivity to the targeted agents lapatinib, PD173074 and crizotinib was only observed in cell lines with the corresponding high expression of the drugs' target protein. SGC031, an MET-positive PDGCX mouse model, responded to crizotinib but not to lapatinib or PD173074.

Conclusions:

Human epidermal growth factor receptor 2, MET and FGFR2 oncogenic driver alterations (gene amplification and overexpression) occur in three largely distinct molecular segments in GC. A significant proportion of HER2-negative patients may potentially benefit from MET- or FGFR2-targeted therapies.

Nin one binding protein expression as a prognostic marker in prostate carcinoma

BACKGROUND

To investigate the prognostic value of expression levels of nin one binding protein (Nob1) in prostate carcinoma.

METHODS

Nob1 protein levels were evaluated by Western blot in samples from 40 prostate carcinomas and matched adjacent non-neoplastic prostate tissues. Nob1 expression was also assessed by immunohistochemistry in samples from 300 prostate carcinoma and matched adjacent non-neoplastic prostate tissues, as well as 20 benign prostatic hyperplasia samples. The findings were compared with clinical and pathologic parameters and patient outcome.

RESULTS

Nob1 protein analysis showed significant differences between the prostate carcinomas and control groups tested. Immunohistochemical analysis showed that Nob1 positivity was higher in prostate carcinoma than that in paired adjacent non-cancerous tissues (58 vs 7 %, P < 0.001). Nob1 positivity was significantly associated with high Gleason scores and metastasis in patients. Nob1 expression was significantly associated with shorter biochemical recurrence-free survival (BCRFS). Multivariate analysis revealed that Nob1 is an independent marker for BCRFS.

CONCLUSIONS

These findings provide evidence that Nob1 is an indicator of poor prognosis in prostate carcinoma.

Genetic polymorphisms of LPL and HL and their association with the performance of Chinese sturgeons fed a formulated diet

It is very important to investigate the reasons for the large individual differences in individual performance of food acceptance when using formulated diets for the successful culture of larvae and juveniles of the Chinese sturgeon Acipenser sinensis. Genetic differences of the mitochondrial control region were investigated by direct sequencing in two groups of Chinese sturgeon, which were apt to accept or refuse formulated diets. Among 968-bp sequences, 111 variable sites were identified. One variable site showed close association with the individual performance of specimens fed with formulated diets. The commercial diet for Chinese sturgeons usually contains high levels of lipids. Lipoprotein lipase (LPL) and hepatic lipase (HL) are two members of the lipase gene family, which are essential for the utilization of dietary lipid. Single nucleotide polymorphisms (SNPs) in intron 7 were detected in the two experimental groups of Chinese sturgeons. We were able to demonstrate that one SNP in the LPL gene and one SNP in the HL gene showed close association with the performance of sturgeons on the formulated diet.

A nosocomial outbreak of KPC-2-producing Klebsiella pneumoniae in a Chinese hospital: dissemination of ST11 and emergence of ST37, ST392 and ST395

In China, Klebsiella pneumoniae carbapenemase (KPC) -producing K. pneumoniae isolates have been identified. However, little is known about the spread and outbreak of KPC-producing enterobacterial pathogens. In this study, 48 non-duplicated KPC-producing isolates were analysed for genetic relatedness by pulsed-field gel electrophoresis (PFGE), antimicrobial susceptibility by E-test, and sequence type (ST) by multilocus sequence typing. S1-PFGE and Southern blot were used for plasmid profiling, and PCR and subsequent sequencing were performed to determine the effects of genetic background on the blaKPC gene. From December 2011 to June 2012, an outbreak of the KPC-2-producing K. pneumoniae was observed. The 48 isolates of K. pneumoniae are categorized into eight PFGE types (A1, A2, A3, A4, B, C, D and E). The predominant pathogens of the outbreak were strains with PFGE types A1, A2 and A3, which all belong to ST11. Furthermore, ST37, ST392 and ST395 KPC-2-producing K. pneumoniae isolates have also been sporadically identified. The blaKPC-2 -carrying plasmids vary in size from 30 to 220 kb. The genetic environments of the blaKPC-2 gene for most strains were consistent with the genetic structure of blaKPC-2 on the plasmid pKP048. In conclusion, the dissemination and outbreak of KPC-2-producing K. pneumoniae isolates in this study appeared to be clonal, and ST11 K. pneumoniae was the predominant clone attributed to the outbreak. This is the first study to report the emergence and spread of KPC-producing K. pneumoniae ST392 and ST395 worldwide. Our findings suggest that horizontal transfer of Tn3-based transposons might mediate the spread of blaKPC-2 gene between different K. pneumoniae clones in China.

Clonal diversity of recurrently mutated genes in myelodysplastic syndromes

Recent studies suggest that most cases of myelodysplastic syndrome (MDS) are clonally heterogeneous, with a founding clone and multiple subclones. It is not known whether specific gene mutations typically occur in founding clones or subclones. We screened a panel of 94 candidate genes in a cohort of 157 patients with MDS or secondary acute myeloid leukemia (sAML). This included 150 cases with samples obtained at MDS diagnosis and 15 cases with samples obtained at sAML transformation (8 were also analyzed at the MDS stage). We performed whole-genome sequencing (WGS) to define the clonal architecture in eight sAML genomes and identified the range of variant allele frequencies (VAFs) for founding clone mutations. At least one mutation or cytogenetic abnormality was detected in 83% of the 150 MDS patients and 17 genes were significantly mutated (false discovery rate ≤0.05). Individual genes and patient samples displayed a wide range of VAFs for recurrently mutated genes, indicating that no single gene is exclusively mutated in the founding clone. The VAFs of recurrently mutated genes did not fully recapitulate the clonal architecture defined by WGS, suggesting that comprehensive sequencing may be required to accurately assess the clonal status of recurrently mutated genes in MDS.

Abstract S5-6: Activating HER2 mutations in HER2 gene amplification negative breast cancers

Background: Breast cancer genome sequencing projects, performed by the genome sequencing centers in the U.S., Canada, and the U.K., are elucidating the somatic mutations and other genomic alterations that occur in human breast cancer. These studies recently identified somatic HER2 mutations in breast cancers lacking HER2 gene amplification.

Results: Compilation of data from seven sequencing studies documented 22 patients with somatic HER2 mutations. These mutations clustered in three regions. The first cluster was at amino acid (aa) 309–310 (exon 8), located in the extracellular domain. These aa residues form part of the HER2 dimerization interface. The second cluster was at aa 755–781, located in the kinase domain (exons 19–20). This was the most common location for HER2 mutations, with 17 out of 22 patients having somatic mutations here. The third region was at aa 835–896, also in the kinase domain (exons 21–22). Using multiple experimental approaches (cell line experiments, in vitro kinase assays, protein structure modeling, and xenograft experiments), we tested seven of these HER2 mutations and showed that 4 of them are activating mutations that are sensitive to lapatinib and trastuzumab. Another 2 mutations were found to be lapatinib resistant and we determined their sensitivity to neratinib, canertinib, and gefitinib.

Conclusions: These findings biologically validate somatic HER2 mutations as good targets for breast cancer treatment, but the appropriate choice of targeted drug is dependent on the precise mutation present. This study is among the first to functionally characterize mutations identified by breast cancer genome sequencing. A prospective, multi-institutional clinical trial has been launched to screen for HER2 mutation positive patients and determine the clinical outcome of treatment with HER2 targeted drugs.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S5-6.

CCL2−2518 (A/G) polymorphisms and tuberculosis susceptibility: a meta-analysis

BACKGROUND

It has been found that the -2518 C-C motif ligand (CCL)-2 promoter variant increases the risk of developing active tuberculosis (TB).

OBJECTIVE

To study the association between -2518 variants and susceptibility to TB.

DESIGN

We searched Medline, PubMed and the Wan Fang databases for human genetic studies on whether the -2518 CCL2 polymorphism influences the expression of active TB. Articles published from January 1998 to November 2010 were included. A random effects model was conducted in the meta-analysis.

RESULTS

The CCL2-2518G allele (OR 1.51, 95%CI 1.11-2.04, P = 0.008) showed significant association with susceptibility to TB. In genotype analysis, the recessive model (CCL2 genotype GG, OR 1.66, 95%CI 1.19-2.33, P = 0.003) was slightly superior to the dominant model (G carrier genotypes OR 1.53, 95%CI 1.07-2.17, P = 0.018). These observations were prominent among Asians and Latin-Americans of Hispanic ancestry, but not in Africans from Ghana and South Africa. The presence of epistatic genes in one population but not in the other, environmental differences and pathogen virulence may account for this.

CONCLUSION

The CCL2-2518G allele increases the risk of developing TB in Asians and Hispanics.

P4-11-02: Insulin-Like Growth Factor-1 (IGF-1), Insulin-Like Growth Factor Binding Protein-3 (IGFBP-3) and Lobule Type among Women in the Nurses' Health Study II (NHS II)

In a previous analysis of women enrolled in NHSII, we found that among women diagnosed with benign breast disease (BBD), those with predominant type 1/no type 3 lobules were at lower risk of subsequent breast cancer compared to women with other lobule types. Additionally, studies in animal models suggest that higher levels of IGF-1, a polypeptide hormone involved in the proliferation/differentiation of normal mammary epithelium, may inhibit involution of breast lobules. However, the interaction between IGF-1 levels and lobule types in determining breast cancer risk has not been previously evaluated. Therefore, we examined the association between IGF-1 levels and lobule type among women with BBD.

Methods: We conducted a cross-sectional study among 484 women in NHSII with biopsy-confirmed BBD between 1993–2001 who had blood samples available for determining levels of IGF-1 and IGFBP-3. A pathologist, blinded to exposure status, classified lobule type on biopsy slides according to the number of acini per lobule (type 1 &lt; 12; type 2∼50; type 3∼80 acini). Lobule type was classified into (1) predominant type 1/no type 3 lobules or (2) other lobule types. Multivariate logistic models were used to assess the associations between plasma IGF-1, IGFBP-3, and IGF-1/IGFBP-3 levels with lobule type. Models were adjusted for age, IGF-1 batch and additional potential confounders in secondary analyses.

Results: In univariate analyses, older age at biopsy, higher body mass index, postmenopausal status, nulliparity, and lower IGF-1 levels were associated with predominant type1/no type 3 lobules (p&lt;0.05). In multivariate logistic models adjusting for age, higher IGF-1 levels were associated with a decreased risk of predominant type 1/no type 3 lobules (OR quartile 4 vs. quartile 1 = 0.35, 95%CI: 0.15−0.81). Greater IGF-1/IGFBP-3 ratio was also associated with a decreased risk of predominant type1/no type 3 lobules (OR quartile 4 vs. quartile 1 = 0.24, 95%CI: 0.10−0.57).

Abstract ES7-1: Next Generation Sequencing for the Clinician: A Breast Cancer Study

The ability to study genome-wide sequence alterations in cancer genomes has transformed our understanding of the intricacies of this disease. We have applied whole genome sequencing and analysis to tease apart the genomic predictors of aromatase inhibitor (AI) response, by selecting luminal breast cancer cases obtained within a clinical trial of aromatase inhibitor treatment (ACOSOG Z1031). Our study compared the constitutional genome to the cancer genome for patients that exhibit either a response or a resistance phenotype, based on their Ki67 IHC score following 4 month AI treatment and resection. My talk will highlight the process by which these genomes are sequenced and analyzed, and will provide our most recent insights into how the combination of the constitutional and somatic genomes determine whether a patient will respond to AI treatment.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr ES7-1.

Conformance Control of CSS and Steam Drive Process With a Carbamide Surfactant

Abstract

Based on physical modelling, this paper discusses the feasibility of injecting additives to control the conformance of the cyclic steam stimulation (CSS) and steam drive processes in the Biquan 10 Block of the Henan Oil Field. The lab test results show that waterflooding with the addition of a carbamide surfactant can decrease residual oil saturation by 4.7% and that steam drive with the addition of this same surfactant can improve the sweep volume and increase the oil recovery factor by 17.5%. Also, field application results confirmed that injecting this surfactant in the CSS and steam drive processes can increase oil production, lower steam-oil ratio (SOR) and improve the economic benefitssignificantly.

Introduction

The CSS process has been applied in developing the heavy oil reservoirs in the Henan Oil Field since the late 1980s. It has been clearly demonstrated that with increasing the cycles of steam stimulation, the oil production rate decreases and SOR can rapidly reach the economic limit. For improving the oil production rate and recovery factor, the steam drive process needs to be applied as a subsequent technology. However, the reservoir in the Henan Oil Field is thin and interbedded so it is a challenge to operate the conventional steam drive process. To reduce the steam channeling effect, a number of high temperature resistant plugging surfactants have been tested, but they could not achieve ideal and persistent results(1). This paper discusses the development of a new kind of conformance control agent ? carbamide surfactant. The lab testing results and field applications of the steam drive process with the addition of a carbamide surfactant in Well Group 577, Biqian 10 Block, Henan Oil Field, are described in detail below.

Mechanism and Physical Modelling

When the carbamide surfactant is injected into the reservoir with steam, carbamide decomposes into CO2 and NH3 under high temperatures. The decomposition can be expressed as follows:

Equation (available in full paper)

The physical modelling shows that, with increasing temperature and pressure, the carbamide decomposes even faster but its concentration does not affect the decomposition speed. The produced CO2 dissolves in heavy oil and NH3 can react with some acid in the oil. As a result, the heavy oil volume expands and viscosity decreases. At 50 °C, when the oil-carbamide solution (30 wt% carbamide) ratio is 4 to 1, the oil viscosity can be reduced by 73% to 80%. The single tube displacement efficiency test shows that adding carbamide solution (30 wt% carbamide) into hot water will increase the displacing efficiency by 6.5%.

Field Application and Discussion

Reservoir Geology and Production History

Well pattern 577 in the east of Biqian 10 block was selected for the field test. The well pattern is an inverted 9-spot with injector-producer spacing of 70 m and 100 m. The pay zone is the IV-9 layer of the H-3 interval in the Hetaoyuan Formation. The basic reservoir parameters are as follows:

Longitudinal pattern of regional brain volume change differentiates normal aging from MCI

BACKGROUND

Neuroimaging measures have potential as surrogate markers of disease through identification of consistent features that occur prior to clinical symptoms. Despite numerous investigations, especially in relation to the transition to clinical impairment, the regional pattern of brain changes in clinically normal older adults has not been established. We predict that the regions that show early pathologic changes in association with Alzheimer disease will show accelerated volume loss in mild cognitive impairment (MCI) compared to normal aging.

METHODS

Through the Baltimore Longitudinal Study of Aging, we prospectively evaluated 138 nondemented individuals (age 64-86 years) annually for up to 10 consecutive years. Eighteen participants were diagnosed with MCI over the course of the study. Mixed-effects regression was used to compare regional brain volume trajectories of clinically normal individuals to those with MCI based on a total of 1,017 observations.

RESULTS

All investigated volumes declined with normal aging (p < 0.05). Accelerated change with age was observed for ventricular CSF (vCSF), frontal gray matter, superior, middle, and medial frontal, and superior parietal regions (p < or = 0.04). The MCI group showed accelerated changes compared to normal controls in whole brain volume, vCSF, temporal gray matter, and orbitofrontal and temporal association cortices, including the hippocampus (p < or = 0.04).

CONCLUSION

Although age-related regional volume loss is apparent and widespread in nondemented individuals, mild cognitive impairment is associated with a unique pattern of structural vulnerability reflected in differential volume loss in specific regions. Early identification of patterns of abnormality is of fundamental importance for detecting disease onset and tracking progression.

Chlamydia pneumoniae infection, complement factor H variants and age-related macular degeneration

BACKGROUND/AIMS

Impaired inhibition of the alternative complement pathway by complement factor H (CFH) is linked to age-related macular degeneration (AMD) based on the strong association between CFH variant and AMD. Chlamydia pneumoniae (C pneumoniae) infection can trigger the alternative pathway, but the evidence for an association between C pneumoniae and AMD is contradictory. This study investigated whether C pneumoniae infection is associated with AMD and whether the presence of C pneumonia modulates AMD risk conferred by CFH variants.

METHODS

Genomic DNA extracted from peripheral blood of 148 advanced AMD patients and 162 controls was subjected to Taqman and PCR-RFLP for the CFH polymorphism and PCR for the C pneumoniae gene. Genomic DNA was also examined from microdissected macular cells from 59 AMD and 16 age-matched non-AMD archived slides. chi(2) testing was performed for case-control analysis.

RESULTS

C pneumoniae infection was associated with increased risk of AMD (OR = 2.17, p<0.017). A CFH variant was also linked to increased risk of AMD (OR = 1.98, p<0.0001). However, no relationship was found between risk-conferring CFH variant and C pneumoniae (OR = 1.81, p = 0.08).

CONCLUSION

There is a possible association between AMD and C pneumoniae infection, although CFH may not be directly involved in the pathogenesis of C pneumoniae infection-mediated AMD.

The role of hepatitis B virus x gene in development of primary hepatocellular carcinoma

Primary hepatocellular carcinoma (HCC) is one of the most common cancers occurring in human, and there is strong epidemiological evidence suggesting that persistent hepatitis B virus (HBV) infection is the most important risk factor for its development.HBx gene was found to be a transactivator recently. Its continuous expression in hepatocytes may transactivate cellular genes which can play a certain role in development of HCC. TheHBx gene fragment was used to construct a recombinant eukaryotic expression vector pCEP4 and introduced into HepG2 cells. The effect ofHBx gene on HCC cells growth and its molecular mechanism in HCC cells regulation were investigated.

Proteomic analysis of human bone marrow mesenchymal stem cells transduced with human telomerase reverse transcriptase gene during proliferation

OBJECTIVES

Previous studies have reported immortalization and tumorigenicity of human mesenchymal stem cells (hMSCs) transduced with exogenous human telomerase reverse transcriptase (hTERT). We also have established a line of hMSCs transduced with hTERT (hTERT-hMSCs) and we have cultured these cells for 290 population doublings (PDs) during which they demonstrated a large proliferation potential but with no tumorigenicity. The aim of this study was to investigate the protein expression profile of hTERT-hMSCs with two-dimensional gel electrophoresis and peptide mass fingerprinting by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, to be able to analyse the effects of exogenous hTERT on protein expression in hMSCs.

MATERIALS AND METHODS

We generated proteome maps of primary hMSCs and hTERT-hMSCs at PD 95 and PD 275.

RESULTS

A total of 1543 +/- 145 protein spots in gels of primary MSCs at PD 12, 1611 +/- 186 protein spots in gels of hTERT-hMSCs at PD 95 and 1451 +/- 126 protein spots in gels of hTERT-hMSCs at 275 PD were detected. One hundred of these were successfully identified, including 20 which were differentially expressed.

CONCLUSIONS

The results suggest that sustaining levels of prohibitin and p53 expression along with differential expression of proteins in hTERT-hMSCs provide an insight into lack of transforming activity of hTERT-hMSCs during cell proliferation.

Segmenting lung fields in serial chest radiographs using both population-based and patient-specific shape statistics

This paper presents a new deformable model using both population-based and patient-specific shape statistics to segment lung fields from serial chest radiographs. There are two novelties in the proposed deformable model. First, a modified scale invariant feature transform (SIFT) local descriptor, which is more distinctive than the general intensity and gradient features, is used to characterize the image features in the vicinity of each pixel. Second, the deformable contour is constrained by both population-based and patient-specific shape statistics, and it yields more robust and accurate segmentation of lung fields for serial chest radiographs. In particular, for segmenting the initial time-point images, the population-based shape statistics is used to constrain the deformable contour; as more subsequent images of the same patient are acquired, the patient-specific shape statistics online collected from the previous segmentation results gradually takes more roles. Thus, this patient-specific shape statistics is updated each time when a new segmentation result is obtained, and it is further used to refine the segmentation results of all the available time-point images. Experimental results show that the proposed method is more robust and accurate than other active shape models in segmenting the lung fields from serial chest radiographs.

Anti-tumor activity of letrozole in patients with recurrent advanced low malignant potential or low-grade serous ovarian tumors

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Purpose: To evaluate the clinical activity of oral Letrozole in patients with recurrent and advanced low malignant potential or low grade serous ovarian tumors and to determine the impact of steroid receptor expression on this observed activity. Methods: In a phase II design, we recruited patients with confirmed recurrent advanced stage low malignant potential tumors and recurrent low-grade serous carcinomas. Measurable disease was required. Steroid hormone expression (ER and PR), EGFR, and Her2/neu expression were determined on available pathological material by IHC from the initial surgery or at documentation of recurrent disease and blood was obtained before enrollment and every other month while on therapy. Letrozole was administered orally at a dose of 2.5 mg once a day. The endpoints were objective response rate assessed by Response Evaluation Criteria in Solid Tumor. Adverse events were graded using the National Cancer Institute Common Toxicity Criteria. Results: Thirteen patients meeting eligibility have been enrolled are evaluable for response and toxicity. From objective clinical parameters (RECIST) no patients had a CR or PR; five patients (38%) had disease stabilizations, eight patients had progressive disease. However, using criteria for CA 125 response, we obtained a complete serologic response in 2 of 13 patients (15%), and a partial serologic response in 2 additional patients (15%); marker stabilization was seen in 5 other patients (38%). CA125 increased in four patients (31%). We also detected the presence of ER, PR, EGFR, Her-2/Neu by IHC, and estradiol in the plasma by ELISA. No significant correlation was observed between tumor marker response and ER expression alone. However, when we evaluated the co-expression of ER/PR we found 3 of 5 (60%) patients had a serologic response compared to just 1 of 8 patients with ER+/PR- tumors (P=0.07). We observed no severe adverse events. Conclusion: Our preliminary data suggests that oral Letrozole has some antitumor activity in recurrent advanced low grade or borderline ovarian tumors and is well tolerated. The analysis of correlation between objective response and combined prediction markers including phosphorylated ER, PR, AKT, and IGFR is ongoing (Supported by CTRF).

No significant financial relationships to disclose.

Amoxicillin pharmacokinetics in pregnant women: modeling and simulations of dosage strategies

Amoxicillin is recommended for anthrax prevention in pregnancy. The objective of this study was to evaluate the pharmacokinetics of amoxicillin during pregnancy and postpartum (PP). Sixteen women received amoxicillin during gestation (18-22 weeks (T2) and 30-34 weeks (T3)) as well as 3 months postpartum (PP) to evaluate single-dose pharmacokinetics. Amoxicillin compartmental pharmacokinetic parameters were used to simulate amoxicillin concentration-time profiles following different dosage strategies. Amoxicillin CL(renal) (T2: 24.8+/-6.7 l/h, P<0.001; T3: 24.0+/-3.9 l/h, P<0.001; and PP: 15.3+/-2.6 l/h) and renal CL(secretion) (T2: 280+/-105 ml/min, P<0.002; T3: 259+/-54 ml/min, P<0.001; and PP: 167+/-47 ml/min) were higher during pregnancy than postpartum. Simulations suggest that amoxicillin concentrations adequate to prevent anthrax may be difficult to achieve during pregnancy and postpartum. Increases in amoxicillin CL(renal) and renal CL(secretion) reflect increases in filtration and secretory transport or diminished reabsorption in the kidneys. Amoxicillin may not be an appropriate antibiotic for post-anthrax exposure prophylaxis.

Rice endophyte Pantoea agglomerans YS19 promotes host plant growth and affects allocations of host photosynthates

AIMS

The aims of the study were to identify the effects of rice endophyte Pantoea agglomerans YS19 on host plant growth and allocations of photosynthates.

METHODS AND RESULTS

Endophytic diazotrophic YS19 showed nitrogen-fixing activity in N-free medium, and produced four categories of phytohormones which were indole-3-acetic acid, abscisic acid, gibberellic acid and cytokinin in Luria-Bertani medium. Inoculation of YS19 improved the biomass of the 12-day-cultivated host rice seedlings by 63.4% on N-free medium or by 18.7% on N-supplemented medium. Spraying of YS19 cell culture onto the rice plants at the premilk stage enhanced the transportation of the photosynthetic assimilation product from the source (flag leaves) to the sink (stachys) significantly. The formation of the plant sink was obviously inhibited when YS19 cell culture was applied at the late milk stage.

CONCLUSIONS

This research suggests that endophyte YS19 promotes host rice plant growth and affects allocations of host photosynthates.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings suggested that YS19 possesses the potential for increasing rice production in field application. Meanwhile, a suitable plant growth stage must be selected for the foliar spraying of YS19 cell culture.

Past adult lead exposure is linked to neurodegeneration measured by brain MRI

OBJECTIVE

To determine whether cumulative lead dose in former organolead workers was associated with MRI measures of white matter lesions (WML) and global and structure-specific brain volumes.

METHODS

MRIs, tibia lead, and other measures were obtained from 532 former organolead workers with a mean age of 56 years and a mean of 18 years since last occupational exposure to lead. Cumulative lead dose was measured by tibia lead, obtained by X-ray fluorescence, and expressed as microg lead per gram of bone mineral (microg Pb/g). WML were evaluated using the Cardiovascular Health Study grading scale. A total of 21 global and specific brain regions were evaluated.

RESULTS

A total of 36% of individuals had WML grade of 1 to 7 (0 to 9 scale). Increasing peak tibia lead was associated with increasing WML grade (p = 0.004). The adjusted OR for a 1 microg Pb/g increase in tibia lead was 1.042 (95% CI = 1.021, 1.063) for a CHS grade of 5+ (> or = 5 vs < 5). In linear regression, the coefficient for tibia lead was negative for associations with all structures. Higher tibia lead was significantly related to smaller total brain volume, frontal and total gray matter volume, and parietal white matter volume. Of nine smaller specific regions of interest, higher tibia lead was associated with smaller volumes for the cingulate gyrus and insula.

CONCLUSIONS

These data suggest that cumulative lead dose is associated with persistent brain lesions, and may explain previous findings of a progressive decline in cognitive function.

Biomarkers detected by proteomic analysis predicts breast cancer response to neoadjuvant chemotherapy

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Background: Neoadjuvant chemotherapy provides an excellent opportunity for objective assessment of treatment-induced tumor response and for studying biomarkers characteristic of therapy-induced tumor responses. Methods: Proteomic analysis of T3/T4 breast cancer was performed in patients with locally advanced breast cancer in a phase II clinical trial. The breast cancer specimen was obtained before and after four cycles of Taxotere/Carboplatin/±Herceptin treatment. Two proteomic approaches, SELDI mass spectrometry and Clontech Ab Microarray 500, were used to screen for protein biomarkers that predict response of breast cancer to chemotherapy. Results: Five tumors with pathologically complete response (pCR) and 29 tumors with various amounts of residual tumors (Non-pCR) were analyzed by SELDI-TOF using the NP 20 chip. The normalized mass signals were compared between pCR vs Non-pCR at each aligned location by Wilcoxon rank sum test. Statistically significant differences were found at 22 m/z locations using a liberal p <0.20 criterion. The best univariate predictor occurred at m/z 14960 (p=0.004), which correctly classified 5/5 pCR spectra (100%) and 24/29 Non-pCR spectra (83%). A multivariate classification tree developed using m/z 14960 and m/z 12138 intensities correctly classified all 34 spectra. Ab microarray analysis was performed on five pCR tumors and in five tumors with the largest residual cancer. The Internal Normalization Ratio (INR) was calculated and used to compare the difference of protein expression between the two groups. Eight differentially expressed protein biomarkers were selected with the criteria of a statistically significant (Student t, p<0.05) expression change of <0.77 or >1.3 fold. Three proteins (Tat-SF1, PYK2 and PTP1B) were higher, and five (E2F2, IL1b, FEN1, CDC37 and ACM1) were lower in tumors with pCR. The unsupervised hierarchical clustering of the 10 samples by these eight proteins completely separated the pCR tumors from the poor responders. Conclusions: Our study suggests that bothSELDImass spectrometry and antibody microarray may be used to predict the tumor response to neoadjuvant chemotherapy. Proteomic analysis may be useful in developing tailored chemotherapy for breast cancer.

[Table: see text]

Virus-induced chalazion

PURPOSE

To investigate a viral etiology in certain chalazia.

METHODS

A prospective study over 7.5 years of all newly presenting chalazia associated with diffuse follicular conjunctivitis but without any other aetiological factors. Patients were investigated for ocular or systemic infections by history, physical exam, slit-lamp exam, and/or histology of conjunctival biopsy (including transmission electron microscopy).

RESULTS

A total of 27 patients developed follicular conjunctivitis without meibomian gland dysfunction, blepharitis, or sexually transmitted diseases. Evidence for a viral aetiology included: recent systemic viral illness (15/27), recent contact with subjects with chalazia or follicular conjunctivitis (5/27), preauricular lymphadenopathy (4/27), viral corneal disease (4/27), or viral particles by ultrastructure (4/4).

CONCLUSIONS

Chalazia may be associated with viral conjunctivitis. Intralesional corticosteroids should be considered with great caution for viral-induced chalazia.

Dissemination of CTX-M type β-lactamases in Enterobacteriaceae isolates in the People’s Republic of China

Previously there have been a number of reports of extended spectrum beta-lactamase (ESBL) producing isolates of the family Enterobacteriaceae in Asia. We first reported the occurrence of bla(CTX-M) in Guangzhou, China, subsequently there have been reports of bla(CTX-M) from a number of other south Asian countries. Initial surveillance study data suggested that bla(CTX-M) might be widely distributed in China. This study examines the type of bla(CTX-M) occurring in other major population centres in China. Initial disk diffusion method susceptibility testing (NCCLS) selected ESBL producing Escherichia coli and Klebsiella pneumoniae isolates from Beijing and near Wuhan, PRC. After screening in both China and the UK, 13 isolates producing CTX-M ESBLs were identified and studied, 11 also produced TEM-1, and 4 also produced SHV-1. Sequence analysis of the bla(CTX-M) containing isolates revealed these isolates contained two different bla(CTX-M), three with bla(CTX-M-3) and 10 with bla(CTX-M-14). After comparison with other previously published studies in the English language, we conclude that the most prevalent bla(CTX-M) so far reported in Asia are bla(CTX-M-14) and bla(CTX-M-3).

Superinfection of Laodelphax striatellus with Wolbachia from Drosophila simulans

Wolbachia are maternally inherited, intracellular alpha-proteobacteria that infect a wide range of arthropods. They manipulate the reproduction of hosts to facilitate their spread into host populations, through ways such as cytoplasmic incompatibility (CI), parthenogenesis, feminization and male killing. The influence of Wolbachia infection on host populations has attracted considerable interest in their possible role in speciation and as a potential agent of biological control. In this study, we used both microinjection and nested PCR to show that the Wolbachia naturally infecting Drosophila simulans can be transferred into a naturally Wolbachia-infected strain of the small brown planthopper Laodelphax striatellus, with up to 30% superinfection frequency in the F(12) generation. The superinfected males of L. striatellus showed unidirectional CI when mated with the original single-infected females, while superinfected females of L. striatellus were compatible with superinfected or single-infected males. These results are, to our knowledge, the first to establish a superinfected horizontal transfer route for Wolbachia between phylogenetically distant insects. The segregation of Wolbachia from superinfected L. striatellus was observed during the spreading process, which suggests that Wolbachia could adapt to a phylogenetically distant host with increased infection frequency in the new host population; however, it would take a long time to establish a high-frequency superinfection line. This study implies a novel way to generate insect lines capable of driving desired genes into Wolbachia-infected populations to start population replacement.

[Application of dot immunogold filtration assay for diagnosis of Schistosomiasis japonica]

AIM

To quest for a simple and convenient assay for the diagnosis of schistosomiasis.

METHODS

Three monoclonal antibodies against different epitopes of antigens of S. japonicum were used to develop a dot immunogold filtration assay for detection of schistosomal antigen-antibody reaction on the membrane during the filtration process. The results could be read with the naked eye within a few minutes.

RESULTS

The sensitivity of the SEA assay was 16 ng/ml. In 69 serum samples from patients with chronic schistosomiasis, the positive rate and specificity of this assay were 60.8% and 95.2%, respectively. Dot-ELISA was used in detecting 137 serum samples from patients with chronic schistosomiasis, the positive rate and specificity were 54.7% and 94.6%, respectively. When sandwich-ELISA was used in detecting 118 serum samples from patients with chronic schistosomiasis, the positive rate and specificity were 61.9% and 95.7%, respectively.

CONCLUSION

The sensitivity and specificity of DIFA were similar to those of ELISA, but DIFA required less time and no special equipment.

Biocatalytic preparation of enantiopure ( R)-ketoprofen from its racemic ester by a new yeast isolate Citeromyces matriensis CGMCC 0573

The yeast strain CGMCC 0573 was identified as Citeromyces matriensis and shown to be capable of enantioselectively hydrolyzing ethyl ester of ( R)-Ketoprofen (2-(3-benzoylphenyl)propionic acid). The strain was isolated for the first time from soil samples through a new and efficient screening procedure in which the probability of obtaining active strains was greatly increased by using ethanol and Tween-80 alternatively as additives during the enrichment culture. Studies of the culture conditions and catalytic performance of Citeromyces matriensis CGMCC 0573 showed that the enzyme occurs constitutively in the cells and its production is enhanced by feeding with Tween-80 during the early period of cultivation. Yeast extract was found to be beneficial both for growth and for esterase production. The optimal temperature and pH for the bioconversion were 40 degrees C and pH 8.0, respectively. Biotransformation using resting cells cultured in a flask with baffles and magnetic stirring and in the presence of 50 mM substrate resulted in the production of ( R)-ketoprofen at 93% ee (enantiomeric excess) and at 42.6% conversion.

Isolation of an esterase-producing Trichosporon brassicae and its catalytic performance in kinetic resolution of ketoprofen

A yeast strain CGMCC 0574, identified as Trichosporon brassicae, was selected from 92 strains for its high (S) selectivity in the hydrolysis of ketoprofen ethyl ester. The effective strains of the microorganisms were isolated from soil samples with the ester as the sole carbon source. The ethyl ester proved to be the best substrate for resolution of ketoprofen among several ketoprofen esters examined. The resting cells of CGMCC 0574 could catalyze the hydrolysis of ketoprofen ethyl ester with an enantiomeric ratio of 44.9, giving (S)-ketoprofen an enantiomeric excess of 91.5% at 42% conversion.

Monoclonal antibodies: a new era in the treatment of non-Hodgkin's lymphoma

Monoclonal antibodies (MAbs) have been used as therapeutic agents for many years. In 1997, Rituxan (IDEC-C2B8, rituximab, MabThera) became the first MAb to be approved by the FDA for a cancer indication. Rituxan served to heighten interest in the therapeutic applications of MAbs. Herceptin (for patients with breast cancer) and Mylotarg (for patients with acute myeloid leukemia) were approved shortly thereafter. Literally dozens of antibodies are currently under investigation for a variety of malignant and non-neoplastic indications. Rituxan is effective in patients with low-grade or follicular, relapsed or refractory non-Hodgkin's lymphoma (NHL). The response rate and time to progression (responders) are in the 50% and 13 months range, respectively. It is also active in intermediate-grade NHL where a large randomized study, in combination with CHOP chemotherapy, has shown a statistically significant increase in complete response (CR) rate (75% vs. 60%), prolongation of 1 year event-free survival (69% vs. 49%) and of overall survival (83% vs. 68%) as compared to CHOP alone. This marks the first time that any agent has shown results superior to CHOP, the curative gold standard for this type of NHL. Other promising antibodies under clinical investigation include: Hu1D10; Anti CD19, 22, 52, and anti-Id antibodies. The safety profile, clinical activity, and mechanism of action of these MAbs make them ideal candidates for combination with chemotherapy or biologicals. Over the next few years, we will see very significant therapeutic advances emerge as this important research yields additional clinical results.