Resonant elastic x-ray scattering (REXS) is an exquisite element-sensitive tool for the study of subtle charge, orbital, and spin superlattice orders driven by the valence electrons, which therefore escape detection in conventional x-ray diffraction (XRD). Although the power of REXS has been demonstrated by numerous studies of complex oxides performed in the soft x-ray regime, the cross section and photon wavelength of the material-specific elemental absorption edges ultimately set the limit to the smallest superlattice amplitude and periodicity one can probe. Here we show – with simulations and REXS on Mn-substituted Sr3Ru2O7 – that these limitations can be overcome by performing resonant scattering experiments at the absorption edge of a suitably-chosen, dilute impurity. This establishes that – in analogy with impurity-based methods used in electron-spin-resonance, nuclear-magnetic resonance, and Mössbauer spectroscopy – randomly distributed impurities can serve as a non-invasive, but now momentum-dependent probe, greatly extending the applicability of resonant x-ray scattering techniques.
To investigate the toxic effects of ethylenediaminetetraacetic acid disodium salt (EDTA), a corneal penetration enhancer in topical ophthalmic formulations, on DNA in human corneal epithelial cells (HCEs), and to investigate whether the effect induced by EDTA can be inhibited by high molecular weight hyaluronan (HA).
Cells were exposed to EDTA in concentrations ranging from 0.00001 to 0.01% for 60 min, or 30 min high molecular weight HA pretreatment followed by EDTA treatment. The cell viability was measured by the MTT test. Cell apoptosis was determined with annexin V staining by flow cytometry. The DNA single- and double-strand breaks of HCEs were examined by alkaline comet assay and by immunofluorescence microscope detection of the phosphorylated form of histone variant H2AX (γH2AX) foci, respectively. Reactive oxygen species (ROS) production was assessed by the fluorescent probe, 2′, 7′-dichlorodihydrofluorescein diacetate.
EDTA exhibited no adverse effect on cell viability and did not induce cell apoptosis in human corneal epithelial cells at concentrations lower than 0.01%. However, a significant increase of DNA single- and double-strand breaks was observed in a dose-dependent manner with all the concentrations of EDTA tested in HCEs. In addition, EDTA treatment led to elevated ROS generation. Moreover, 30 min preincubation with high molecular weight HA significantly decreased EDTA-induced ROS generation and DNA damage.
EDTA could induce DNA damage in HCEs, probably through oxidative stress. Furthermore, high molecular weight HA was an effective protective agent that had antioxidant properties and decreased DNA damage induced by EDTA.
hyaluronan; EDTA; DNA damage; ROS; corneal epithelial cell
Sirtuin 3 (Sirt3), a major mitochondrial NAD+-dependent deacetylase, targets various mitochondrial proteins for lysine deacetylation and regulates important cellular functions such as energy metabolism, aging, and stress response. In this study, we identified the human 8-oxoguanine-DNA glycosylase 1 (OGG1), a DNA repair enzyme that excises 7,8-dihydro-8-oxoguanine (8-oxoG) from damaged genome, as a new target protein for Sirt3. We found that Sirt3 physically associated with OGG1 and deacetylated this DNA glycosylase and that deacetylation by Sirt3 prevented the degradation of the OGG1 protein and controlled its incision activity. We further showed that regulation of the acetylation and turnover of OGG1 by Sirt3 played a critical role in repairing mitochondrial DNA (mtDNA) damage, protecting mitochondrial integrity, and preventing apoptotic cell death under oxidative stress. We observed that following ionizing radiation, human tumor cells with silencing of Sirt3 expression exhibited deteriorated oxidative damage of mtDNA, as measured by the accumulation of 8-oxoG and 4977 common deletion, and showed more severe mitochondrial dysfunction and underwent greater apoptosis in comparison with the cells without silencing of Sirt3 expression. The results reported here not only reveal a new function and mechanism for Sirt3 in defending the mitochondrial genome against oxidative damage and protecting from the genotoxic stress-induced apoptotic cell death but also provide evidence supporting a new mtDNA repair pathway.
Sirt3; OGG1; mitochondria; DNA repair; apoptosis
The aim of this study was to diagnose microvascular invasion in patients with solitary hepatocellular carcinoma (HCC) from pre-operative CT imaging.
102 patients with solitary HCC who underwent curative hepatectomy were retrospectively included in our study. The pre-operative 3-phase CT imaging and laboratory data for the 102 patients were reviewed. Tumour size, tumour margin, peritumoral enhancement and α-fetoprotein level were assessed. Surgical pathology was reviewed; tumour differentiation, liver fibrosis score and microvascular invasion were recorded.
The histopathological results revealed that 50 HCCs were positive and the other 52 were negative for microvascular invasion. Univariate analysis revealed that tumour size (p=0.036), higher Edmondson–Steiner grade (p=0.047) and non-smooth tumour margin (p<0.001) showed statistically significant associations with microvascular invasion. Multivariate logistic regression analysis showed that non-smooth tumour margin had a statistically significant association with microvascular invasion only (p<0.001). The sensitivity, specificity, positive predictive value and negative predictive value of the non-smooth tumour margin in the prediction of microvascular invasion were 66%, 86.5%, 82.5% and 72.6%, respectively.
Non-smooth tumour margin in pre-operative CT had a statistically significant association with microvascular invasion. More aggressive treatment should be considered in HCC patients with suspected positive microvascular invasion.
The effect of bisphenol A (BPA) on the reproductive system is highly debated but has been associated with meiotic abnormalities. However, evidence is lacking with regard to the mechanisms involved. In order to explore the underlying mechanisms of BPA-induced meiotic abnormalities in adult male rats, we exposed 9-week-old male Wistar rats to BPA by gavage at 0, 2, 20 or 200 μg/kg body weight (bw)/day for 60 consecutive days. 17β-Estradiol (E2) was administered at 10 μg/kg bw/day as the estrogenic positive control. Treatments with 200 μg/kg bw/day of BPA and E2 significantly decreased sperm counts and inhibited spermiation, characterized by an increase in stage VII and decrease in stage VIII in the seminiferous epithelium. This was concomitant with a disruption in the progression of meiosis I and the persistence of meiotic DNA strand breaks in pachytene spermatocytes,and the ataxia–telangiectasia-mutated and checkpoint kinase 2 signal pathway was also activated; Eventually, germ cell apoptosis was triggered as evaluated by terminal dUTP nick-end labeling assay and western blot for caspase 3. Using the estrogen receptor (ER) antagonist ICI 182780, we determined that ER signaling mediated BPA-induced meiotic disruption and reproductive impairment. Our results suggest that ER signaling-mediated meiotic disruption may be a major contributor to the molecular events leading to BPA-related male reproductive disorders. These rodent data support the growing association between BPA exposure and the rapid increase in the incidence of male reproductive disorders.
bisphenol A; meiocyte spreading; meiosis; spermatogenesis; stage of seminiferous epithelium
The role of the serine protease HtrA2 in neuroprotection was initially identified by the demonstration of neurodegeneration in mice lacking HtrA2 expression or function, and the interesting finding that mutations adjacent to two putative phosphorylation sites (S142 and S400) have been found in Parkinson's disease patients. However, the mechanism of this neuroprotection and the signalling pathways associated with it remain mostly unknown. Here we report that cyclin-dependent kinase-5 (Cdk5), a kinase implicated in the pathogenesis of several neurodegenerative diseases, is responsible for phosphorylating HtrA2 at S400. HtrA2 and Cdk5 interact in human and mouse cell lines and brain, and Cdk5 phosphorylates S400 on HtrA2 in a p38-dependent manner. Phosphorylation of HtrA2 at S400 is involved in maintaining mitochondrial membrane potential under stress conditions and is important for mitochondrial function, conferring cells protection against cellular stress.
HtrA2; Cdk5; phosphorylation; mitochondria; Parkinson's disease
Pinellia pedatisecta agglutinin (PPA) is a specific mannose-binding plant lectin accumulated in the tuber of P. pedatisecta. In the work presented, the cytotoxicity of PPA to cancer cells was investigated through exogenous expression. A PPA gene was transduced into normal and cancer cell lines through plasmid vectors, and the effect of PPA expression was examined. Results showed that PPA translocated into the nucleus, colocalized with DNA and induced cell death. A mannose-binding motif and a V103-W130 region directed the nuclear translocation of PPA. Coprecipitation, mass spectrometry and western blotting analysis further indentified that PPA was associated with the methylosome, which contains methylosome protein 50 and protein arginine methyltransferase 5 (PRMT5). Knockdown of PRMT5 significantly inhibited the PPA-induced cell death, suggesting that PPA used the methylosome as a target. Furthermore, Ad.surp-PPA, an adenovirus vector in which the PPA gene was controlled by a survivin promoter (surp), selectively inhibited the proliferation of cancer cell lines. Taken together, the expression of PPA gene elicited significant cytotoxicity to cancer cells through targeting the methylosome and might be developed into a novel agent in cancer gene therapy.
methylosome; Pinellia pedatisecta agglutinin; MEP50; PRMT5; nuclear translocation
Knowing the inter-unit variability, especially the technological error, is important when using many physiological measurement systems, yet no such inter-unit analysis has been undertaken on duplicate automated gas analysis systems. This study investigated the inter-unit performance of two identical ParvoMedics TrueOne 2400 automated gas analysis systems during a range of submaximal steady-state exercises performed on an electromagnetic cycle ergometer. Fifteen adult males were tested on two separate days a rest, 30, 60, 90, and 120 Watts with the duplicate gas analysis units arranged (1) collaterally (2 min of steady-state expired gas was alternately passed through each system), and (2) simultaneously (identical steady-state expired gas was passed simultaneously through both systems). Total within-subject variation (biological + technological) was determined from the collateral tests, but the unique inter-unit variability (technological error between identical systems) was shown by the simultaneous tests. Absolute percentage errors (APE), coefficient of variations (CV), effect sizes and Bland–Altman analyses were undertaken on the metabolic data, including expired ventilation (VE), oxygen consumption (VO2) and carbon dioxide production (VCO2). The few statistically significant differences detected between the two duplicate systems were determined to have small or trivial effect sizes, and their magnitudes to be of little physiological importance. The total within-subject variations for VO2, VCO2 and VE each equated to a mean CV and mean APE value of ~4 and ~6 %, whilst the respective inter-unit technological errors equated to ~1.5 and ~2.1 %. The two ParvoMedics TrueOne 2400 systems demonstrated excellent inter-unit agreement.
Variation; Agreement; Technological error; ParvoMedics; Gas analysis
Circulating endothelial cells (CECs) are a candidate biomarker for monitoring angiogenesis in cancer. Circulating endothelial cell subsets are mobilised by angiogenic mediators. Because of the highly angiogenic phenotype of renal cell carcinoma (RCC), we sought to assess the potential of CECs as a marker of RCC in patients with von Hippel-Lindau (VHL) disease and those with sporadic RCC.
We performed multicolour flow cytometry to enumerate CECs in patients with RCC, patients with VHL disease with and without RCC, and normal subjects. Two subsets of CECs were evaluated: mature CECs (mCECs) and circulating endothelial progenitors (CEPs).
In patients with VHL disease and RCC and those with sporadic RCC (N=10), CEPs and the CEP:mCEC ratio were higher than in normal subjects (N=17) (median CEPs: 0.97 vs 0.19 cells μl−1, respectively, P<0.01; median CEP:mCEC: 0.92 vs 0.58, respectively, P=0.04). However, in patients with VHL without RCC, CECs were not increased. In paired pre- and post-nephrectomy RCC patient samples (N=20), CEPs decreased after surgery (median difference 0.02 cells μl−1, −0.06 to 1.2; P=0.05).
Circulating endothelial progenitors were elevated in RCC, but not in patients with VHL without RCC. Circulating endothelial progenitor enumeration merits further investigation as a monitoring strategy for patients with VHL.
circulating endothelial cells; von Hippel-Lindau (VHL) disease; renal cancer; biomarker; angiogenesis
Previous studies have shown the feasibility of using diffusion tensor imaging (DTI) as a noninvasive imaging modality to evaluate neurodegeneration in humans and animals. The axial and radial diffusivities derived from DTI were demonstrated to be sensitive markers for axonal and myelin damage, respectively. This study used DTI to evaluate optic nerve degeneration in wild-type and slow Wallerian degeneration (WldS) mutant mice. Longitudinal DTI was performed on optic nerves following high intraocular pressure-induced transient retinal ischemia. The axial diffusivity of wild-type nerves decreased 30% (P<0.05) at 3 days and 40% (P<0.05) at 5–30 days after transient elevation of intraocular pressure. In contrast, the axial diffusivity of WldS nerves did not change at 3 days; decreased by 20% (P<0.05) at 5 days, and continued to decrease by 30% (P<0.05) at 15 days and 40% (P<0.05) at 30 days after transient intraocular pressure elevation, suggesting delayed axonal damage in WldS mice. Radial diffusivity increased 200% (P<0.05) at 15–30 days in the wild-type mice and 100% (P<0.05) at 30 days in the WldS mice after transient intraocular pressure elevation, suggesting delayed myelin damage in WldS mice. DTI detected damage was confirmed with immunohistochemistry using phosphorylated neurofilament and myelin basic protein for assessing axonal and myelin integrity, respectively. These findings support the use of DTI not only to evaluate the progression of neurodegeneration but also to noninvasively demonstrate WldS mutation to delay the Wallerian degeneration.
diffusion tensor imaging; axial diffusivity; radial diffusivity; WldS mouse; axon degeneration; myelin damage
Parathyroid adenomas can contain clonal rearrangements of chromosome 11 that activate the cyclin D1 oncogene through juxtaposition with the PTH gene. Here we describe such a chromosomal rearrangement whose novel features provide clues to locating elusive cis-regulatory elements in the PTH gene and also expand the physical spectrum of pathogenetic breakpoints in the cyclin D1 gene region. Southern analyses of the parathyroid adenoma revealed rearrangement in the PTH gene locus. Analysis of rearranged DNA clones that contained the breakpoint, obtained by screening a tumor genomic library, pinpointed the breakpoint in the PTH locus at 3.3 kb upstream of the first exon. Accordingly, highly conserved distal elements of the PTH 5’ regulatory region were rearranged at the breakpoint approximately 450 kb upstream of the cyclin D1 oncogene, resulting in overexpression of cyclin D1 mRNA. Thus, PTH-cyclin D1 gene rearrangement breakpoints in parathyroid tumors can be located far from those previously recognized. In addition to expanding the molecular spectrum of pathogenetic chromosomal lesions in this disease, features of this specific rearrangement reinforce the existence of one or more novel cis-enhancer/regulatory elements for PTH gene expression and narrow their location to a 1.7kb DNA segment in the distal PTH promoter.
hyperparathyroidism; parathyroid neoplasia; parathyroid hormone; PTH; cyclin D1
Virulent factors produced by pathogens play an important role in the infectious process, which is regulated by a cell-to-cell communication mechanism called quorum sensing (QS). Pseudomonas aeruginosa is an important opportunistic human pathogen, which causes infections in patients with compromised immune systems and cystic fibrosis. The QS systems of P. aeruginosa use N-acylated homoserine lactone (AHL) as signal molecules. Previously we have demonstrated that Panax ginseng treatment allowed the animals with P. aeruginosa pneumonia to effectively clear the bacterial infection. We postulated that the ability to impact the outcome of infections is partly due to ginseng having direct effect on the production of P. aeruginosa virulence factors. The study explores the effect of ginseng on alginate, protease and AHL production. The effect of ginseng extracts on growth and expression of quorum-sensing (QS)-controlled virulence factors on the prototypic P. aeruginosa PAO1 and its isogenic mucoid variant (PAOmucA22 or PDO300) was determined. Ginseng did not inhibit the growth of the bacteria, enhanced the extracellular protein production and stimulated the production of alginate. However, ginseng suppressed the production of LasA and LasB and down-regulated the synthesis of the AHL molecules. Ginseng has a negative effect on the QS system of P. aeruginosa, which might be part of the mechanisms that ginseng helped the bacterial clearance from the animal lungs in vivo in our previous animal study. It is possible that enhancing and repressing activities of ginseng are mutually exclusive as it is a complex mixture, as shown with the HPLC anaylsis of the hot water extract of ginseng that was performed in this study. Though ginseng is a promising natural synergetic remedy, it is important to isolate and evaluate the ginseng compounds associated with the anti-QS activity.
Ginseng; Pseudomonas aeruginosa; anti-quorum sensing; LasA; LasB; Alginate
Using two in vivo methods, microdialysis and rapid in situ electrochemistry, this study examined the modulation of extracellular glutamate levels by endogenously produced kynurenic acid (KYNA) in the prefrontal cortex (PFC) of awake rats. Measured by microdialysis, intraperitoneal (i.p.) administration of KYNA's bioprecursor L-kynurenine dose-dependently elevated extracellular KYNA and reduced extracellular glutamate (nadir after 50 mg/kg kynurenine: 60% decrease from baseline values). This dose-dependent decrease in glutamate levels was also seen using a glutamate-sensitive microelectrode array (MEA) (31% decrease following 50 mg/kg kynurenine). The kynurenine-induced reduction in glutamate was blocked (microdialysis) or attenuated (MEA) by co-administration of galantamine (3 mg/kg, i.p.), a drug that competes with KYNA at an allosteric potentiating site of the α7 nicotinic acetylcholine receptor. In separate experiments, extracellular glutamate levels were measured by MEA following the local perfusion (45 min) of the PFC with kynurenine (2.5 μM) or the selective KYNA biosynthesis inhibitor S-ethylsulfonylbenzoylalanine (S-ESBA; 5 mM). In agreement with previous microdialysis studies, systemic kynurenine application produced a reversible reduction in glutamate (nadir: −29%), whereas perfusion with S-ESBA increased glutamate levels reversibly (maximum: +38%). Collectively, these results demonstrate that fluctuations in the biosynthesis of KYNA in the PFC bi-directionally modulate extracellular glutamate levels, and that qualitatively very similar data are obtained by microdialysis and MEA. Since KYNA levels are elevated in the PFC of individuals with schizophrenia, and since prefrontal glutamatergic and nicotinic transmission mediate cognitive flexibility, normalization of KYNA levels in the PFC may constitute an effective treatment strategy for alleviating cognitive deficits in schizophrenia.
α7 Nicotinic receptor; Astrocytes; Microelectrode array; Schizophrenia
We measured the effects of non-nucleoside reverse transcriptase (RT) inhibitor-resistant mutations K101E+G190S, on replication fitness and EFV-resistance of HIVNL4-3. K101E+G190S reduced fitness in the absence of EFV and increased EFV-resistance, compared to either single mutant. Unexpectedly, K101E+G190S also replicated more efficiently in the presence of EFV than in its absence. Addition of the nucleoside-resistance mutations L74V or M41L+T215Y to K101E+G190S improved fitness and abolished EFV-dependent stimulation of replication. D10, a clinical RT backbone containing M41L+T215Y and K101E+G190S, also demonstrated EFV dependent stimulation that was dependent on the presence of K101E. These studies demonstrate that non-nucleoside reverse transcriptase inhibitors can stimulate replication of NNRTI-resistant HIV-1 and that nucleoside-resistant mutants can abolish this stimulation. The ability of EFV to stimulate NNRTI-resistant mutants may contribute to the selection of HIV-1 mutants in vivo. These studies have important implications regarding the treatment of HIV-1 with combination nucleoside and non-nucleoside therapies.
HIV-1; drug resistance; drug-dependent stimulation of replication; replication fitness; non-nucleoside reverse transcriptase inhibitors; nucleoside reverse transcriptase inhibitors
To assess the relationship between serum C3 or C4 levels and lupus renal flare, C3 and C4 levels were measured bimonthly in 71 lupus nephritis patients for a mean of 35 months, during which time 70 renal flares were identified. Comparing baseline, pre-flare, and at-flare values indicated that neither C3 nor C4 levels decreased pre-flare, but both decreased on average significantly at flare. However, sensitivity/specificity for C3 (75%/71%) and C4 (48%/71%) were low. To account for other influencing factors, multiple regression was performed that included bimonthly values of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), and genotype data on C3 (S/F), CRP (1846G > A), and the complement regulator factor H (Y402H). This analysis revealed that reduced levels of C4, but not C3, were independently associated with the two-month pre-flare period. Conversely, reduced levels of C3, but not C4, were independently associated with the flare visit. Significant pro-flare interactions included low C3 levels with the factor H 402HH-encoding genotype, and low CRP levels with the C3 F allele. Together these data suggest that C4 activation is critical for initiating renal flare while C3 activation is involved in the actual tissue damage, and that these effects are influenced by genetic variability in complement activation and regulation.
C3; C4; lupus nephritis; renal flare
Fluctuations in the endogenous levels of kynurenic acid (KYNA), a potent α7 nicotinic and NMDA receptor antagonist, affect extracellular dopamine (DA) concentrations in the rat brain. Moreover, reductions in KYNA levels increase the vulnerability of striatal neurons to NMDA receptor-mediated excitotoxic insults. We now assessed the role of a key KYNA-synthesizing enzyme, kynurenine aminotransferase II (KAT II), in these processes in the rodent striatum, using KAT II KO mice—which have reduced KYNA levels—and the selective KAT II inhibitor (S)-4-(ethylsulfonyl)benzoylalanine (S-ESBA) as tools. S-ESBA (applied by reverse dialysis) raised extracellular DA levels in the striatum of KYNA-deficient mice threefold and caused a much larger, 15-fold increase in wild-type mice. In the rat striatum, S-ESBA produced a 35% reduction in extracellular KYNA, which was accompanied by a 270% increase in extracellular DA. The latter effect was abolished by co-infusion of 100 nM KYNA. Intrastriatal S-ESBA pre-treatment augmented the size of a striatal quinolinate lesion by 370%, and this potentiation was prevented by co-infusion of KYNA. In separate animals, acute inhibition of KAT II reduced the de novo synthesis of KYNA during an early excitotoxic insult without enhancing the formation of the related neurotoxic metabolites 3-hydroxykynurenine and quinolinate. Taken together, these results provide further support for the concept that KAT II is a critical determinant of functionally relevant KYNA fluctuations in the rodent striatum.
astrocytes; excitotoxicity; Huntington's disease; kynurenine aminotransferase II; neuroprotection
Tumor angiogenesis has been associated with poor prognosis in patients with metastatic melanoma (MM). Microtubule stabilizers and cyclooxygenase (COX)-2 inhibitors, alone and in combination, have shown inhibitory effects on endothelial cells and tumor angiogenesis. Angiogenesis, the growth of new blood vessels, is necessary for tumor growth and progression. Thus, we tested the safety and efficacy of a low dose of paclitaxel and celecoxib in patients with MM.
Patients received paclitaxel 10mg/m2 for 96 hours weekly by CIV and celecoxib 400 mg po/bid. Systemic tumor response was assessed at 6 week intervals. Tumor measurements at the end of Cycle 1 were used as the baseline for assessment of tumor progression. Patients with unacceptable toxicity or disease progression after Cycle 2 relative to the end of Cycle 1 were taken off study.
Twenty patients were enrolled. Twelve (60%) had received 2 or more prior systemic therapies. Three patients did not receive treatment due to rapid disease progression. Treatment related grade 3–4 toxicities were limited to catheter-related complications. One patient achieved a partial response and 3/20 (15%) patients had stable disease for greater than 6 months. Median time to progression was 57 days (95% CI: 43–151) and median overall survival was 212 days (95% CI: 147–811 days.
Low-dose, CIV paclitaxel and oral celecoxib can produce disease stabilization in a significant proportion of heavily pre-treated patients with MM. These findings support a role for metronomic therapy in this disease.
metastatic; melanoma; metronomic; Cox-2; clinical trial; phase II
The Florida Center of Excellence for Biomolecular Identification and Targeted Therapeutics (FCoE-BITT, www.bitt.usf.edu, located on the Tampa campus of the University of South Florida (USF), is a comprehensive center that enhances interactions between scientists and engineers to identify molecules of human health significance and to develop novel methods for use in diagnosis, prevention and treatment of human disease. FCoE-BITT encompasses the full range of product development, from discovery to commercialization. It is expected to create an infrastructure that supports collaboration across several academic units (USF Health, USF College of Arts and Sciences, USF College of Engineering) and move research into commercial applications through its close collaboration with various technology transfer resources. In support of this mission, the FCoE-BITT recently opened three fee-for-service core laboratories: the Proteomics Core, the NMR Core and the Biotechnology Development and Testing Facility. The Proteomics Core supports large-scale protein isolation, identification and characterization (mass spectrometry, differential expression profiling, analysis of post-translational modifications of proteins, quantitative proteomic analyses). The NMR Core utilizes two Varian NMR systems (600 and 800 MHz) for protein structure biology and dynamics determinations, and for structural analyses of natural and synthetic organic molecules for pharmaceutical development. The Biotechnology Development and Testing Facility provides equipment for material fabrication/analysis and for performing in vitro tests on biological samples, four suites for eukaryotic and bacterial cell culture (to biosafety level 2) as well as custom testing services, consultation and training for drug discovery, drug delivery and medical device/sensor development projects. These three FCoE-BITT core laboratories serve USF faculty and students, external academic institutes and regional companies.
Few studies have examined the association between passive smoking and the risk of oesophageal and gastric adenocarcinomas. In a population-based case–control study with 2474 participants in Los Angeles County, there was no evidence that passive smoking had any appreciable effect on oesophageal or gastric adenocarcinomas.
passive smoking; oesophageal adenocarcinoma; gastric adenocarcinoma; case-control study; cigarette smoking; polychotomous logistic regression
This study demonstrates that a combination of unconventional electron microscopy techniques provides a quantitative means of assessing the degree of monodispersity of gadolinium (Gd) diethylenetriamine pentaacetic acid-conjugated polyamidoamine (PAMAM) dendrimers, which are designed for diagnostic imaging and delivering chemotherapeutics. Specifically, analysis of images acquired in the scanning transmission electron microscopy mode yields the distribution of molecular weights of individual dendrimers, whereas analysis of images acquired in the energy-filtering transmission electron microscopy mode yields the distribution of Gd atoms bound to the dendrimer nanoparticles. Measured compositions of Gd-conjugated G7 and G8 PAMAM dendrimers were consistent with the known synthetic chemistry. The G7 dendrimers had a mass of 330 ± 4 kDa and 266 ± 4 Gd atoms (± standard error of the mean). The G8 dendrimers had a mass of 600 ± 8 kDa and 350 ± 5 Gd atoms (± standard error of the mean). This approach will be particularly attractive for assessing the mass, composition and homogeneity of metal-containing organic nanoparticles used in nanomedicine.
dendrimer; EFTEM; energy-filtered transmission electron microscopy; gadolinium; mass measurement; scanning transmission electron microscopy; STEM
Low–moderate risk alleles that are relatively common in the population may explain a significant proportion of the excess familial risk of ovarian cancer (OC) not attributed to highly penetrant genes. In this study, we evaluated the risks of OC associated with common germline variants in five oncogenes (BRAF, ERBB2, KRAS, NMI and PIK3CA) known to be involved in OC development. Thirty-four tagging SNPs in these genes were genotyped in ∼1800 invasive OC cases and 3000 controls from population-based studies in Denmark, the United Kingdom and the United States. We found no evidence of disease association for SNPs in BRAF, KRAS, ERBB2 and PIK3CA when OC was considered as a single disease phenotype; but after stratification by histological subtype, we found borderline evidence of association for SNPs in KRAS and BRAF with mucinous OC and in ERBB2 and PIK3CA with endometrioid OC. For NMI, we identified a SNP (rs11683487) that was associated with a decreased risk of OC (unadjusted Pdominant=0.004). We then genotyped rs11683487 in another 1097 cases and 1792 controls from an additional three case–control studies from the United States. The combined odds ratio was 0.89 (95% confidence interval (CI): 0.80–0.99) and remained statistically significant (Pdominant=0.032). We also identified two haplotypes in ERBB2 associated with an increased OC risk (Pglobal=0.034) and a haplotype in BRAF that had a protective effect (Pglobal=0.005). In conclusion, these data provide borderline evidence of association for common allelic variation in the NMI with risk of epithelial OC.
risk of ovarian cancer; polymorphism; oncogene; association studies
Recent studies have detected mutations in the EDA gene, previously identified as causing X-linked hypohidrotic ectodermal dysplasia (XLHED), in two families with X-linked non-syndromic hypodontia. Notably, all affected males in both families exhibited isolated oligodontia, while almost all female carriers showed a milder or normal phenotype. We hypothesized that the EDA gene could be responsible for sporadic non-syndromic oligodontia in affected males. In this study, we examined 15 unrelated males with non-syndromic oligodontia. Three novel EDA mutations (p.Ala259Glu, p.Arg289Cys, and p.Arg334His) were identified in four individuals (27%). A genetic defect in the EDA gene could result in non-syndromic oligodontia in affected males.
EDA gene; oligodontia; mutation; non-syndromic
The search for genetic variants associated with ovarian cancer risk has focused on pathways including sex steroid hormones, DNA repair, and cell cycle control. The Ovarian Cancer Association Consortium (OCAC) identified 10 single-nucleotide polymorphisms (SNPs) in genes in these pathways, which had been genotyped by Consortium members and a pooled analysis of these data was conducted. Three of the 10 SNPs showed evidence of an association with ovarian cancer at P⩽0.10 in a log-additive model: rs2740574 in CYP3A4 (P=0.011), rs1805386 in LIG4 (P=0.007), and rs3218536 in XRCC2 (P=0.095). Additional genotyping in other OCAC studies was undertaken and only the variant in CYP3A4, rs2740574, continued to show an association in the replication data among homozygous carriers: ORhomozygous(hom)=2.50 (95% CI 0.54-11.57, P=0.24) with 1406 cases and 2827 controls. Overall, in the combined data the odds ratio was 2.81 among carriers of two copies of the minor allele (95% CI 1.20–6.56, P=0.017, phet across studies=0.42) with 1969 cases and 3491 controls. There was no association among heterozygous carriers. CYP3A4 encodes a key enzyme in oestrogen metabolism and our finding between rs2740574 and risk of ovarian cancer suggests that this pathway may be involved in ovarian carcinogenesis. Additional follow-up is warranted.
ovarian cancer; genetic susceptibility; oestrogen metabolism; CYP3A4; pooled-analyses