Disrupted topological properties of brain white matter networks in left temporal lobe epilepsy: a diffusion tensor imaging study

Mesial temporal lobe epilepsy (mTLE) is the most common drug-refractory focal epilepsy in adults. Although previous functional and morphological studies have revealed abnormalities in the brain networks of mTLE, the topological organization of the brain white matter (WM) networks in mTLE patients is still ambiguous. In this study, we constructed brain WM networks for 14 left mTLE patients and 22 age- and gender-matched normal controls using diffusion tensor tractography and estimated the alterations of network properties in the mTLE brain networks using graph theoretical analysis. We found that networks for both the mTLE patients and the controls exhibited prominent small-world properties, suggesting a balanced topology of integration and segregation. However, the brain WM networks of mTLE patients showed a significant increased characteristic path length but significant decreased global efficiency, which indicate a disruption in the organization of the brain WM networks in mTLE patients. Moreover, we found significant between-group differences in the nodal properties in several brain regions, such as the left superior temporal gyrus, left hippocampus, the right occipital and right temporal cortices. The robustness analysis showed that the results were likely to be consistent for the networks constructed with different definitions of node and edge weight. Taken together, our findings may suggest an adverse effect of epileptic seizures on the organization of large-scale brain WM networks in mTLE patients.

Neuroglobin - a potential biological marker of retinal damage induced by LED light

Neuroglobin (NGB), a protein highly expressed in the retina, has been shown to be up-regulated to protect neurons from hypoxic and ischemic injuries. It exhibits neuroprotective functions and plays an important role in the survival of neurons. Recent studies show that light-emitting diode (LED) white light emitted significant amounts of blue light (short-wavelength), which may be harmful to retinal cells, but the studies about biomarkers for evaluating the damage from LED white light are still insufficient. In our study, we found that NGB levels in the retina showed a twofold increase and peaked at 1h after a 1-h exposure to blue light (453 nm) which did not cause damage to the retina. However, retinal damage was observed after 2h of blue-light irradiation, which induced an approximate sevenfold increase of NGB levels as confirmed by Western blot and RT-PCR analysis. Immunofluorescence study demonstrated that NGB was predominantly up-regulated in the ganglion cell layer (GCL), plexiform layer (PL) and photoreceptor layer (PRL). We also examined Ngb mRNA and protein expression in the damaged retina induced by light of other wavelengths given equal photon fluxes. The LED red light (625 nm), green light (527 nm) and blue light (453 nm) increased the expression of NGB and caused TdT-mediated dUTP nick-end labeling-positive cells, especially in the blue-light group. In addition, a negative correlation between NGB and rhodopsin was observed. These findings suggested that there was a correlation between NGB expression and the severity of the retinal damage, indicating NGB's potential function as a biological marker of retinal damage induced by LED light.

Production and repair of implant-induced microdamage in the cortical bone of goats after long-term estrogen deficiency

SUMMARY

By using an ovariectomized goat model, we found that estrogen depletion decreases bone quality and makes it susceptible to screw-induced mechanical microdamage. Both diffuse microdamage and linear cracks accumulated up to 3 weeks after screw implantation, and the microdamage was repaired gradually after 4-8 months.

INTRODUCTION

The aim of this study was to observe the effect of long-term estrogen deficiency on the creation and repair of microdamage in cortical bone adjacent to bone screw.

METHODS

Cortical bone screws were placed in the tibial diaphyses 28 months after ovariectomy (OVX) or sham operation (Sham-Op) in female goats. The goats were euthanized at 0 day, 21 days, 4 months, and 8 months after screw implantation. Microdamage morphology and repair were examined in peri-screw bone using histomorphometric method, and the nanomechanical properties of peri-screw bone were examined with nanoindentation testing.

RESULTS

Tibiae from ovariectomized goats in which screws had been placed had significantly higher levels of diffuse microdamage and significantly more linear cracks than those from sham goats, and the diffuse microdamage was more obvious than linear cracks in the region adjacent to the implant. Both diffuse microdamage and linear cracks accumulated up to day 21 and then gradually repaired at 4 and 8 months after surgery. The trend for bone remodeling in each group was consistent with changes in the level of microdamage. Nanoindentation testing showed that both elastic modulus and hardness in peri-screw bone were significantly decreased in OVX group compared to Sham-Op group. The hardness and elastic modulus also showed a downward trend up to 4 months after screw implantation and then exhibited some recovery after 8 months.

CONCLUSIONS

Estrogen depletion decreases bone quality and makes it vulnerable to screw-induced mechanical damage, which may compromise the initial stability of an orthopedic implant.

Effect of chemical additives on Bacillus thuringiensis (Bacillales: Bacillaceae) against Plutella xylostella (Lepidoptera: Pyralidae)

To examine the effect of chemical additives on Bacillus thuringiensis (Berliner) against Plutella xylostella (L.), inorganic salts, nitrogenous compounds, protein solubilizing agents, and organic acids were selected and tested. The chosen materials are low in cost and environmentally safe. Results show that many inorganic salts can increase the activity of B. thuringiensis in a range of 1.31- to 3.08-fold. These include calcium acetate, calcium chloride, calcium hydroxide, calcium sulfate, calcium carbonate, sodium carbonate, sodium acetate, potassium hydroxide, potassium carbonate, potassium acetate, magnesium chloride, magnesium sulfate, and zinc sulfate. Nitrogenous compounds, including peptone, sodium nitrate, and ammonium nitrate, can enhance the activity of B. thuringiensis 1.62-, 1.32-, and 1.37-fold, respectively. Among the protein solubilizing agents, EDTA, urea, mercaptoethanol and dipotassium hydrogen phosphate increased the activity of B. thuringiensis 1.62- to 2.34-fold. Among the organic acids, maleic and citric acids boosted the activity 1.45- and 1.55-fold, respectively. Meanwhile, sodium benzoate and resorcinol led to 1.74- and 1.44-fold activity gains, respectively. Use of appropriate additives could provide great benefit not only in reducing the costs for field applications of biological insecticides but also by boosting the efficacy of B. thuringiensis.

Leptonic-decay-constant ratio f(K+)/f(π+) from lattice QCD with physical light quarks

A calculation of the ratio of leptonic decay constants f(K+)/f(π+) makes possible a precise determination of the ratio of Cabibbo-Kobayashi-Maskawa (CKM) matrix elements |V(us)|/|V(ud)| in the standard model, and places a stringent constraint on the scale of new physics that would lead to deviations from unitarity in the first row of the CKM matrix. We compute f(K+)/f(π+) numerically in unquenched lattice QCD using gauge-field ensembles recently generated that include four flavors of dynamical quarks: up, down, strange, and charm. We analyze data at four lattice spacings a ≈ 0.06, 0.09, 0.12, and 0.15 fm with simulated pion masses down to the physical value 135 MeV. We obtain f(K+)/f(π+) = 1.1947(26)(37), where the errors are statistical and total systematic, respectively. This is our first physics result from our N(f) = 2+1+1 ensembles, and the first calculation of f(K+)/f(π+) from lattice-QCD simulations at the physical point. Our result is the most precise lattice-QCD determination of f(K+)/f(π+), with an error comparable to the current world average. When combined with experimental measurements of the leptonic branching fractions, it leads to a precise determination of |V(us)|/|V(ud)| = 0.2309(9)(4) where the errors are theoretical and experimental, respectively.

MicroRNA-181b expression in prostate cancer tissues and its influence on the biological behavior of the prostate cancer cell line PC-3

We examined microRNA-181b (miRNA) expression in prostate cancer tissues and its effect on the prostate cancer cell line PC-3. Tissues from 27 cases of prostate cancer and 30 samples of normal human prostate were collected by surgical removal. Total miRNA was extracted, and the relative expression of miR-181b was quantified using RT-PCR. miR-181b ASO was transfected into prostate cancer PC-3 cells. miR-181b expression in transfected and non-transfected cells was measured using RT-PCR. Changes in cell apoptosis were measured using flow cytometry. MTT and cell growth curve methods were used to assess the influence of miR-181b expression on cell proliferation. The changes in cell invasive ability in vitro were detected using the Transwell chamber method. miR-181b was up-regulated in the prostate cancer tissues compared with the normal prostate samples. It was down-regulated after miR-181b ASO transfection into the prostate cancer PC-3 cells. Down-regulation of miR-181b in the PC-3 cell induced apoptosis, inhibited proliferation, and depressed invasion of PC-3 cells in vitro. As miR-181b is over-expressed in prostate cancer, its down-regulation could have potential as gene therapy for prostate cancer by inducing apoptosis, inhibiting proliferation and depressing invasion by cancer cells.

Combined isotope and enantiomer analysis to assess the fate of phenoxy acids in a heterogeneous geologic setting at an old landfill

Phenoxy acid herbicides and their potential metabolites represent industrial or agricultural waste that impacts groundwater and surface waters through leaching from old landfills throughout the world. Fate assessment of dichlorprop and its putative metabolite 4-CPP (2-(4-chlorophenoxy)propionic acid) is frequently obstructed by inconclusive evidence from redox conditions, heterogeneous geologic settings (e.g. clay till) and ambiguous parent-daughter relationships (i.e. 4-CPP may be daughter product or impurity of dichlorprop). For the first time, a combination of four methods was tested to assess transformation of phenoxy acids at a contaminated landfill (Risby site): analysis of (i) parent and daughter compound concentrations, (ii) enantiomer ratios (iii) compound-specific isotope analysis and (iv) enantiomer-specific isotope analysis. Additionally, water isotopes and chloride were used as conservative tracers to delineate two distinct groundwater flow paths in the clay till. Metabolite concentrations and isotope ratios of chlorinated ethenes demonstrated dechlorination activity in the area with highest leachate concentrations (hotspot) indicating favorable conditions also for dechlorination of dichlorprop to 4-CPP and further to phenoxypropionic acid. Combined evidence from concentrations, enantiomer ratios and isotope ratios of dichlorprop and 4-CPP confirmed their dechlorination in the hotspot and gave evidence for further degradation of 4-CPP downgradient of the hotspot. A combination of 4-CPP enantiomer and isotope analysis indicated different enantioselectivity and isotope fractionation, i.e. different modes of 4-CPP degradation, at different locations. This combined information was beyond the reach of any of the methods applied alone demonstrating the power of the new combined approach.

Emergence of resistance to fluoroquinolones and third-generation cephalosporins in Shigella flexneri subserotype 1c isolates from China

We report here on the first identification of Shigella flexneri subserotype 1c in China. We also report the emergence of resistance to ciprofloxacin and third-generation cephalosporins in this subserotype 1c for the first time. Isolates of seven strains circulating in China yielded three new sequence types and seven pulsed-field gel electrophoresis patterns, thus demonstrating the existence of high genetic diversity within the isolates. Overall, the seven isolates showed reduced susceptibility to ciprofloxacin; one isolate was ciprofloxacin resistant, whilst another developed resistance to ciprofloxacin, norfloxacin, cefotaxime and ceftriaxone.

Effect of risedronate on osteocyte viability and bone turnover in paired iliac bone biopsies from early postmenopausal women

It is unclear whether standard clinical doses of risedronate affect osteocyte viability. This study examined osteocyte viability and bone remodeling rate in early postmenopausal women (1-5 years after menopause) who were treated with a standard clinical dose of risedronate (5 mg/day, orally) for 1 year. Paired transiliac bone biopsies were obtained from 19 postmenopausal women at baseline and after 1-year treatment with placebo (n = 8, mean age 52.9 ± 3.4 years) or risedronate 5 mg/day (n = 11, mean age 52.5 ± 3.4 years). In these samples, we measured osteocyte- and bone remodeling-related variables in trabecular bone. In both the placebo and risedronate groups, empty lacunae were significantly decreased after 1-year treatment compared to baseline. There were no significant differences in osteocyte-related variables between placebo and risedronate. Risedronate significantly reduced bone-remodeling indices including mineralizing surface (MS/BS), bone formation rate (BFR/BS), and activation frequency (Ac.f). Risedronate treatment caused significantly lower MS/BS and Ac.f than placebo administration. In conclusion, risedronate 5 mg/day effectively inhibited bone remodeling but did not significantly reduce osteocyte viability in trabecular bone.

Practice and Attitudes towards CYP2D6 Testing for Patients on Tamoxifen among US Oncologists

Background: CYP2D6 genotype has been associated with breast cancer outcomes for patients on Tamoxifen (TAM) and testing is commercially available. In the context of emerging data regarding the clinical relevance of CYP2D6 testing (CYPT) and uncertainty regarding how test results should be used in practice, we evaluated current practice and attitudes with regard to this novel pharmacogenomic test among U.S. oncologists.Methods: A survey was mailed to all breast cancer oncologists identified at National Comprehensive Cancer Network (NCCNO) centers and a random sample of community based oncologists (CBO) identified from the American Society of Clinical Oncology directory. The survey evaluated knowledge of the CYP2D test, use of the test, requests for the test by patients and third parties, and response to hypothetical test results. Associations between practice setting and CYP2D6 knowledge, CYPT, and practice patterns were evaluated. All statistical tests were two-sided.Results: 201 of 459 (44%) oncologists responded, including 97/173 (56%) of NCCNO and 104/286 (36%) of CBO. While 90% of all oncologists were aware of CYPT, only 31% had ever ordered CYPT, and only 14% used CYPT for ≥ 10% of patients on TAM. 22% had received a request for CYPT from a 3rd party. While NCCNO were more likely to be aware of CYPT (98% vs. 82%, p < 0.001), and to receive requests for CYPT (33% vs. 12%, p < 0.001), CBO reported higher frequency of CYPT in routine practice (21% vs. 11%, p = 0.06). Despite rare use, 66% of CBO and 44% of NCCNO reported they would order the test upon patient request (p < 0.001). In hypothetical scenarios involving CYPT for patients on TAM, for premenopausal women with poor metabolism, 33% would make no change, while 38% would switch to ovarian suppression (OS) plus aromatase inhibitor (AI), 9% would switch to OS alone, and 8% would add OS to TAM. CBO were more likely to switch to OS + AI in this setting (47% vs. 31%, p < 0.02), while NCCNO were more likely to recommend no change (50% vs. 18%, p < 0.001). For premenopausal intermediate metabolizers, 33% of CBO would change management, compared to 8% of NCCN (p < 0.001), with addition of OS to TAM being most frequent among both groups. For postmenopausal women with poor metabolism the majority of both CBO and NCCNO would switch to AI (82% vs. 71%, p = 0.08). Among oncologists who indicated they might change management based on CYPT results, 43% had never ordered the test. Respondents cited data from randomized trials, and professional guidelines as most influential for decisions regarding ordering tests.Conclusion: Despite calls for increased CYP2D6 testing at academic meetings and occasional requests by 3rd parties, use of CYPT is currently infrequent in oncology practice. Greater familiarity with breast cancer management correlated with lower use of CYPT and greater reluctance to change management based on test results at this time. Diversity in practice patterns and knowledge suggests a need for greater consensus on CYPT in routine practice, and highlights the need for further clinical research in this area.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1077.

Immunogenicity of Ra1A and its tissue-specific expression in hepatocellular carcinoma

In order to understand the immunogenicity of a tumor-associated antigen (TAA), Ras family small GTP binding protein (Ra1A) in hepatocellular carcinoma (HCC), autoantibody responses to RalA were evaluated by enzyme-linked immunosorbent assay (ELISA), Western blotting and indirect immunofluorescence assay in sera from patients with HCC and sera from normal individuals. Immunohistochemistry (IHC) study with tissue array slides was also performed to analyze protein expression profiles of RalA in HCC and control tissues. This study demonstrated that RalA had a relative higher frequency of autoantibody response in HCC (20.1%) compared to liver cirrhosis (3.3%), chronic hepatitis (0%), and normal individuals sera (0%). RalA also showed a stepwise increased expression from normal liver tissues (26.7%), liver cirrhosis tissues (45.0%) to HCC tissues (63.3%). Sensitivity and specificity of anti-RalA antibody in detection of HCC was 20.1% and 99.3%, respectively. The data suggested that RalA might contribute to liver malignant transformation, and could be used as a potential tumor marker in HCC detection.

Exercise training improved insulin sensitivity and ovarian morphology in rats with polycystic ovary syndrome

Hyperandrogenism and hyperinsulinemia are major clinical features in women with polycystic ovary syndrome (PCOS). We hypothesized that serum insulin levels reduced by exercise could relieve hyperandrogenism and ameliorate polycystic ovarian morphology. Wistar female rats with 21-day-old were randomly divided into three groups: PCOS exercise (P-Ex), PCOS sedentary (P-Sed), and control sedentary (C-Sed). The rats with PCOS were induced by injection with testosterone propionate continuously. The exercise program was to swim with 120 min/d for two weeks. Fasting blood glucose (FBG) and insulin (FINS), estrogen (E (2)), progesterone (P), and testosterone (T) in serum were determined by RIA, and ovarian morphology was evaluated by Image-Pro Plus 6.0. The levels of FINS, E (2), and T in serum were significantly lower in P-Ex than in P-Sed. The ratios of FBG/FINS in P-Ex significantly increased in comparison with P-Sed. The levels of serum sex hormones in P-Ex were similar to C-Sed. There were no differences in blood glucose and serum progesterone among three groups. Ovarian morphology showed that the numbers of preantral follicles and atretic follicles significantly decreased, and the numbers of antral follicles and corpora lutea significantly increased in P-Ex compared with P-Sed. The changes of ovarian morphology in P-Ex were similar to C-Sed. These results demonstrated that short-term exercise training can improve insulin sensibility, decrease serum androgen levels, and recover normal ovarian morphology. The exercise training is the basic therapeutic means for PCOS.

Effect of (-)-gossypol (AT-101) on transcriptional regulation of Noxa and Puma and on Mcl-1-mediated cancer cell resistance to apoptosis

e14611

Background: AT-101 is being evaluated in Phase II clinical trials for the treatment of human cancers and demonstrates anticancer activity as a single agent and in combination with docetaxel. Despite extensive investigations, the mechanism of action for its antitumor activity is not completely understood. In this study, we have performed detailed investigations using a panel of human cancer cell lines on the mechanism of action for AT-101. Methods: A series of human breast and prostate cancer cell lines were utilized to evaluate the antitumor activity of AT-101. Cell growth inhibition, cell viability and apoptosis were determined by WST assay, trypan blue assay and flow cytometry, respectively. Gene specific siRNAs were used to knockdown target gene expression. Quantitative RT- PCR was performed to detect the mRNA levels of Puma and Noxa. Co-immunoprecipitation was carried out to detect the association between Mcl-1 and Noxa or Puma. Results: AT-101 induced apoptosis in both Bax/Bak-dependent and -independent manners in a variety of human cancer cell lines concomitant with increased expression of Noxa and Puma in a p53-independent manner. The up-regulation of Noxa was not observed in normal primary breast epithelial cells or normal-like human breast epithelial MCF-12F cells. Transcription inhibitor actinomycin D blocked AT-101-induced up-regulation of Puma and Noxa. Knockdown of Noxa or Puma attenuated AT-101-induced apoptosis. Furthermore, AT-101 effectively overcame Mcl-1-mediated cancer cell resistance to apoptosis. Co-immunoprecipitation studies demonstrated that Mcl-1 specifically associated with Noxa but not Puma. Conclusions: Our findings suggest that transcriptional up-regulation of pro-apoptotic Noxa and Puma contributes to the antitumor activity of AT-101, which plays a dominant role in antagonizing Mcl-1 and overcoming Mcl-1-mediated resistance to apoptosis of cancer cells. AT-101 functions as an antagonist of Bcl-2, Bcl-xL and Mcl-1 through direct binding to these proteins, as well as through upregulation of Noxa and Puma.

[Table: see text]

High expression levels of putative hepatic stem/progenitor cells biomarkers related to tumor angiogenesis and poor prognosis of hepatocellular carcinoma

e22121

Background: To investigate the prognostic values of putative hepatic stem/progenitor cells (HSCs/HPCs) biomarkers in hepatocellular carcinoma (HCC) patients. Methods: Fourteen biomarkers related with HSCs/HPCs or tumor angiogenesis were assessed by qRT-PCR and then validated by tissue microarrays (TMAs) in three independent cohorts of HCC patients underwent curative resection (n=67, 314 and 73). Results: Most of the biomarkers were found over-expressed in recurrent HCC patients by qRT-PCR. HSCs/HPCs biomarkers cytokeratin 19, ABCG2, CD133, Nestin, CD44 and angiogenesis agents CD34, VEGF and PD-ECGF, were confirmed as significant predictors for overall survival (OS) and/or relapse-free survival (RFS) in TMAs analysis. Compared with the low HSCs/HPCs profile group, patients with high HSCs/HPCs profile had significantly lower OS and RFS (p<0.0001), expressed higher VEGF levels (p = 0.012) and microvessel density (MVD, determined by CD34 immunostaining, p = 0.030). Based on Cox regression, a simplified model including CD133, CD44, Nestin, and MVD was constructed and confirmed as an independent predictor for OS (p<0.0001) and RFS (p<0.0001), regardless of alpha-fetoprotein level, tumor stage and recurrence time (p<0.0001 for all). Conclusions: High expression levels of HSCs/HPCs biomarkers are related to tumor angiogenesis and poor prognosis of HCC. The simplified model based on HSCs/HPCs and tumor angiogenesis profile can be used to classify HCC patients with high risk of tumor recurrence after operation.

No significant financial relationships to disclose.

Expression of CD24 as a predictor of prognosis of hepatocellular carcinoma after operation

e22043

Background: CD24 expression has previously been reported in hepatocellular carcinoma (HCC), although little is known about its prognostic significance. The aim of this study is to evaluate the relation of CD24 expression and its prognostic significance in HCC. Methods: CD24 expression in stepwise metastatic HCC cell lines and tumor tissues from 50 HCC patients was investigated by quantitative real-time reverse transcription-PCR and Western blot analyses. The role of CD24 was investigated by depletion CD24 expression in HCC cells through small-interfering RNA. Tumor tissue microarrays of 314 HCC patients who underwent resection between 1997 and 2000 were used to detect the expressions of CD24, β-catenin and PCNA expression. The prognostic significance was assessed using Kaplan-Meier survival estimates and log-rank tests. Results: CD24 was overexpressed in the high metastatic HCC cell line and in tumor tissues of recurrent patients. Depletion of CD24 caused a notable decrease in cell proliferation, migration and invasiveness in vitro. CD24 was confirmed as an independent predictor for overall survival (p<0.001) and relapse-free survival (p<0.001), regardless of recurrence time, AFP level, TNM stage and Edmondson stage. High expression of CD24 in HCC tissues was significantly associated cytoplasmic/nuclear accumulation of β-catenin (p=0.023), high tumor proliferate status (p=0.018) and diffused intrahepatic recurrence and distance metastasis (p=0.026). Adjuvant TACE after operation reduced the early recurrence (≤1 year) in CD24+ HCC patients (p=0.024), while there had no significant changes in CD24- patients (p=0.284). Conclusions: High expression levels of CD24 were related with high invasive and metastatic potential, high tumor proliferation status and activation of Wnt/β-catenin pathway. The expression of CD24 provides new prognostic information about HCC prognosis and targeted therapy to CD24+fraction in HCC may comprise a promising anti-recurrence strategy for HCC patients after surgery.

No significant financial relationships to disclose.

Magnetic resonance imaging of primary cerebral gliosarcoma: a report of 15 cases

BACKGROUND

Gliosarcomas are rare tumors with mixed glial and mesenchymal components. Many of their radiologic features resemble those of other primary brain malignancies.

PURPOSE

To investigate the magnetic resonance (MR) imaging features of gliosarcomas.

MATERIAL AND METHODS

We retrospectively reviewed the MR images, pathology reports, and clinical information of 11 male and four female patients aged 15-71 years to evaluate the location, morphology, enhancement, and other features of their pathologically confirmed gliosarcomas.

RESULTS

Apart from one tumor in the right cerebellar hemisphere, all were supratentorial. Two tumors were intraventricular, and four involved the corpus callosum. The tumors were well demarcated, with an inhomogeneous or cystic appearance and moderate-to-extensive surrounding edema. Thick walls with strong rim and ring-like enhancement were observed in 13 (87%). Seven (47%) showed intratumoral paliform enhancement.

CONCLUSION

Gliosarcoma demonstrates certain characteristic MR features, such as supratentorial and peripheral location, well-demarcated, abutting a dural surface, uneven and thick-walled rim-like or ring enhancement, as well as intratumoral strip enhancement. These findings, combined with patient age, can aid the differential diagnosis of gliosarcomas from more common primary brain tumors.