Four-color laser white illuminant demonstrating high color-rendering quality

Solid-state lighting is currently based on light-emitting diodes (LEDs) and phosphors. Solid-state lighting based on lasers would offer significant advantages including high potential efficiencies at high current densities. Light emitted from lasers, however, has a much narrower spectral linewidth than light emitted from LEDs or phosphors. Therefore it is a common belief that white light produced by a set of lasers of different colors would not be of high enough quality for general illumination. We tested this belief experimentally, and found the opposite to be true. This result paves the way for the use of lasers in solid-state lighting.

Insulin-like growth factor-2 (IGF-2) activates estrogen receptor-α and -β via the IGF-1 and the insulin receptors in breast cancer cells

The estrogen receptor (ER) is a primary target for breast cancer (BC) treatment. As BC progresses to estrogen-independent growth, the insulin-like growth factor-1 receptor (IGF-1R) and the ER interact in synergistic cross-talk mechanisms, which result in enhanced activation of both receptors' signaling cascades. Insulin-like growth factor-2 (IGF-2) is critical in BC progression and its actions are mediated by the IGF-1R. Our previous studies showed that IGF-2 regulates survival genes that protect the mitochondria and promote chemoresistance. In this study, we analyzed BC cells by subcellular fractionation, Western-Blot, qRT-PCR, and siRNA analysis. Our results demonstrate that IGF-2 activates ER-α and ER-β, and modulates their translocation to the nucleus, membrane organelles, and the mitochondria. IGF-2 actions are mediated by the IGF-1R and the insulin receptor. This novel mechanism of IGF-2 synergistic cross-talk signaling with ER-α and ER-β can promote estrogen-independent BC progression and provide new therapeutic targets for the treatment of BC patients.

Non-laxative CT colonography with barium-based faecal tagging: is additional phosphate enema beneficial and well tolerated?

OBJECTIVE

The purpose of this study was to investigate the efficacy and tolerance of an additional phosphate enema prior to non-laxative CT colonography (CTC).

METHODS

71 patients (mean age 80 years, 28 male, 43 female) underwent non-laxative CTC following 4 oral doses of diluted 2% w/w barium sulphate. Patients were invited to self-administer a phosphate enema 2 h before CTC. An experienced observer graded the volume of retained stool (1 (nil) to 4 (>75% bowel circumference coated)), retained fluid ((1 (nil) to 4 (>50% circumference obscured)), retained stool tagging quality (1 (untagged) to 5 (≥75% to 100%) tagged) and confidence a polyp ≥6 mm could be excluded (yes/no) for each of six colonic segments. Tolerance of the enema was assessed via questionnaire. Data were analysed between those using and not using the enema by Mann-Whitney and Fisher's exact test. 18/71 patients declined the enema.

RESULTS

There was no reduction in residual stool volume with enema use compared with non-use either overall (mean score 2.6 vs 2.7, p = 0.76) or in the left colon (mean 2.3 vs 2.4, p = 0.47). Overall tagging quality was no different (mean score 4.4 vs 4.3, p = 0.43). There was significantly more retained left colonic fluid post enema (mean score 1.9 vs 1.1, p<0.0001), and diagnostic confidence in excluding polyps was significantly reduced (exclusion not possible in 35% segments vs 21% without enema, p = 0.006). Of 53 patients, 30 (56%) found the enema straightforward to use, but 4 (8%) found it unpleasant.

CONCLUSION

Phosphate enema use prior to non-laxative CTC leads to greater retained fluid, reducing diagnostic confidence, and is not recommended.

Brain polysomes: response to environmental stimulation

Polysomes have been isolated from rat brain and characterized by their appearance in the electron microscope and by their sedimentation in sucrose density gradients. Rats were isolated for 3 days in the dark and were then returned to the light for 15 minutes. The polysomes in brain, but not in liver, decreased in rats deprived of light and increased in those stimulated with light. These findings together with an increased capacity for protein synthesis in the brain in vitro and in vivo suggest that an increase in the activity of messenger RNA in the brain may result from environmental changes.

Genetic Susceptibility as a Possible Risk Factor for Breast Cancer

Background: Established risk factors for breast cancer (BC) only explain 25% to 47% of BC incidence. The Gail model is commonly used to assess BC risk and determine eligibility for prevention trials. Unfortunately, it has a discriminatory accuracy of 58% at the individual level. A greater understanding of BC risk factors is needed to offer improved risk stratification and prevention. It is plausible that BC risk may be related to deficiencies or abnormalities in DNA repair and cell cycle checkpoints because of their importance in maintaining genomic integrity. Recent epidemiologic studies support this hypothesis. In this pilot project, the bleomycin mutagen sensitivity assay (MSS), a measure of genetic susceptibility was performed on women of low, intermediate, and high risk based on commonly used risk models to determine if there was any correlation between MSS and established BC risk factors.Methods: Women in the Prevention Clinic at RPCI consented to donate blood for this study as part of the Data Bank and BioRepository (DBBR). Gail and Claus Models were calculated using CancerGene. Women were stratified into three groups low (&lt;20%), intermediate (20%-35%), and high (&gt; 35%) lifetime BC risk. For logistic regression analysis, women were grouped into low risk (&lt;20%) and high risk (≥20%). MSS in blood lymphocytes were performed at LCCC using fresh blood samples. The mean values of MSS were compared between low, intermediate, and high risk groups using Wilcoxon-Mann-Whitney tests. Multivariate logistic regression was used to analyze the relationship between BC risk groups and MSS.Results: A total of 78 women were enrolled in the study. MSS were performed on 70 blood samples and 67 had evaluable slides. There were 30, 26 and 11 women in the low, intermediate, and high risk groups respectively. The mean age was 49.1 years. There was no statistical difference between the three groups with respect to age, race, menopausal status, proportion of patients with a family history of BC or another cancer, and smoking status (never, former, or current). The mean MSS score was not significantly different among the three risk groups: mean ±SD = 0.86±0.37, 0.84±0.37 (p=0.565), and 0.76+0.44 (0.361) for low, intermediate and high risk groups respectively. Spearman correlation revealed that MSS score did not correlate with Gail lifetime BC risk score (r=-0.054, p=0.668) or Claus model-10 year risk score (r=-0.057, p=0.722). Using the median in low risk women as a cut point, when women who had higher MSS score were compared with women had lower MSS score, the adjusted OR was 1.16 (95% CI, 0.29 to 4.57), adjusted for age, race, smoking status, BMI and menopausal status. When the MSS score were categorized into quartiles, no significant dose-response relationship was observed.Conclusions: In this pilot study, there was no correlation between commonly used breast cancer risk assessment models based on hormonal, family and biopsy history and the MSS in our study population. Previous case-control studies have consistently shown that MSS is significantly associated with BC risk. The lack of correlation between mutagen sensitivity and Gail or Claus risk score suggests that mutagen sensitivity may measure the host susceptibility factors that are not considered by Gail or Claus risk models.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6067.

Variants in the BRCA1/Fanconi-Anemia Repair Pathway and Taxane-Induced Neuropathy in SWOG S0221

Background: Taxane-induced peripheral neuropathy is a dose-limiting side effect that leads to suboptimal cancer treatment and diminished quality of life. The mode of taxane neurotoxicity is unclear, but may be through stabilization of microtubules and induction of spindle checkpoint, leading to cell cycle arrest at G2/M. Fanconi Anemia (FA) genes, including FANCD2, and FANCA, appear to be involved in G2/M phase checkpoint maintenance as well as spindle checkpoint in response to internal and external signals, such as taxane treatment. Thus, we hypothesized that variants in FA genes could impact severity of taxane-induced neuropathies.Methods: Using DNA extracted from blood collected from 893 breast cancer patients participating in a trial evaluating metronomic dosing of cyclophosphamide, doxorubicin and paclitaxel (S0221), we genotyped for single nucleotide polymorphisms (SNPs) that represent all of the variability across FANCA (44 SNPs) and FANCD2 (24 SNPs) in all race/ethnicity groups, as well as a panel of ancestry informative markers to control for potential population stratification, using Illumina GoldenGate platform. SNPs with minor allele frequency (MAF) less than 0.10 and those out of Hardy Weinberg Equilibrium (HWE) proportions (p&lt;0.001) were removed from analyses. Ordinal regression was used to test for allelic and haplotypic association with grade 3 or 4 toxicities relative to 0, 1, and 2 toxicities, adjusting for age, genetic admixture index and treatment arm. To adjust for multiple testing, permutation analyses were performed on both single SNP and haplotype models.Results: Eighteen SNPs in FANCD2 and 38 SNPs in FANCA passed MAF and HWE proportion requirements. For FANCD2, 4 SNPs spanning 67.5 Kb (rs7648104, rs2272125 [coding SNP], rs6786638 and rs644215), were significantly associated with taxane-induced neuropathy (p&lt;0.001) after controlling for multiple testing, with each SNP resulting in approximately a twofold increase in odds of severe taxane-induced neuropathy. Haplotype estimation showed that all 18 SNPs comprise a single haplotype. Two major (&gt;1% frequency) haplotypes were found. The frequencies of the risk haplotype in cases (patients with grade 3 or 4 neuropathy) and controls (patients with ≤ grade 2 neuropathy) were 0.25 and 0.15, respectively. Ordinal regression analyses were highly significant (p&lt;0.0005); patients with at least one copy of the risk haplotype had more than a twofold increased risk of grade 3 or 4 taxane-induced neuropathy (OR=2.2, 95% CI 1.44, 3.44). For FANCA, no SNPs or haplotypes were significantly associated with grade 3 or 4 neurotoxicity, either prior to or after correction for multiple testing.Conclusions: These results indicate that the Fanconi-Anemia pathway may be important for neurological sensitivity to taxanes, and that genotypic markers might be able to be used to identify patients at increased risk for severe taxane-induced neuropathy. Further studies will elucidate potential associations with survival outcomes.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2001.

A Gynecologic Oncology Group study of associations between polymorphisms in ABC transporter genes (ABCB1, ABCC2, and ABCG2) and outcome in advanced stage epithelial ovarian cancer treated with platinum and taxane chemotherapy

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Background: This study evaluated the relationship between known functional variants in three ATP-binding cassette (ABC) transporter genes (ABCB1 [MDR1], ABCC2 [MRP2], and ABCG2 [BCRP]) and clinical outcomes in epithelial ovarian cancer (EOC). These genes induce resistance to multiple anticancer drugs and some polymorphisms appear to affect expression, stability or activity of these transporters. Methods: Genotypes for common polymorphisms in ABCB1 (G2677T/A, A893S/T -RS2032582 and C3435T, synonymous-RS1045642), ABCC2 (G1249A, V417I-RS2273697), and ABCG2 (C421A, Q141K-RS2231138) were determined in normal blood DNA from 385 women with optimal stage III ECO who participated in a randomized phase III trial (GOG 172 or 182) and were treated with intravenous or intraperitoneal platinum+paclitaxel. Associations between polymorphisms and progression-free survival (PFS) and overall survival (OS) were examined using logrank test and adjusted Cox regression analysis. Results: The genotype distribution for the C421A polymorphism in ABCG2 was 80.7%, 18.5% and 0.8% for CC, CA and AA, respectively. Median time to disease progression or death for the CA+AA versus (vs.) CC genotype in ABCG2 was 30.3 vs. 18.1 months (p = 0.023), or 69.8 vs. 51.6 months (p = 0.172), respectively. After adjusting for clinical covariates, women with the CA+AA vs. CC genotype in ABCG2 had a significant reduction in the risk of disease progression (hazard ratio [HR] = 0.67, 95% confidence interval [CI] = 0.49–0.91, p = 0.01) but not death (HR = 0.77, 95% CI = 0.56–1.08, p = 0.125). The results were consistent across treatments. Adjusted Cox modeling demonstrated that polymorphisms in ABCB1 (G2677T/A or C3435T) and ABCC2 (G1249A) were not associated with PFS or OS. Conclusions: The ABCG2 C421A polymorphism, but not the ABCB1 G2677T/A, ABCB1 C3435T, or ABCC2 G1249A polymorphism, appears to be an independent prognostic factor for disease progression in optimal stage III EOC treated with platinum + paclitaxel therapy.

No significant financial relationships to disclose.

Effect of 25 hydroxy vitamin D status on serological response to influenza vaccine in cancer patients

e20575

Background: Increasing epidemiologic data suggest association of vitamin D deficiency with influenza epidemic. Vitamin D acts as an immune modulator and stimulates the expression of protective anti-microbial peptides. We conducted a prospective influenza vaccination study to determine the influence of vitamin D status on serological response to flu vaccine in cancer patients. Methods: Cancer patients at Roswell Park Cancer Institute were offered trivalent (H1N1, H3N2, B/Malaysia) Flu vaccine (Fluzone, 2006–7) and sera collected for hemagglutination inhibition (HI) assay titers. Response to vaccination was defined as ≥ 1:40 titer ratio or a 4 fold increase in HI titer at 3 months post vaccination, against any of the 3 strains. Chi-square tests were performed to compare serological response between the groups with lowest and highest quartiles of baseline 25 (OH) vitamin D (D) level. Logistic regression model was used using other covariates such as age, gender, cancer type, and chemotherapy (CT) as controls. Results: 85 patients with colorectal, 35 with prostate, 1 with anal and 1 with gastric adenocarcinoma participated in the study. Median age was 62 years (range: 24–87 years), 85 (70%) were males. Overall serological response was 59%. Median baseline D level was 42.9 ng/mL (range: 4.0–92.8 ng/mL); lowest and highest quartiles were 26.9 and 53.4 ng/mL. There was no association between serological response and baseline D level (p=0.42) or the lowest and highest quartiles of D level (p=0.6). The odds of response did not vary by sex (p=0.95). CRC patients (OR-0.051; 95% CI-0.013 to 0.209; p<0.0001) were less likely to respond. Few patients (n=20; 16%) were D deficient (<20ng/mL), 43 had D < 32ng/mL .70 patients (54.7%) were on vitamin D supplements. Among those in whom the dose of supplement was known (46),the median daily vitamin D supplement dose was 2000 IU (800–9000 IU).There was no association between serological response and dose (p=0.09). There was no difference in the response rates among patients on D supplement 44/70 (62.9%) versus those not on any D supplement 28/52 (53.8%)(p=0.32). Conclusions: Vitamin D status, in a population in which vitamin D supplementation was commonly used, did not affect serological response to influenza vaccine.

No significant financial relationships to disclose.

A monoclonal antibody identifying a T-cell marker in the horse

A cell surface molecule of equine T lymphocytes was identified and characterized using a mouse monoclonal antibody, HT23A. The molecule was detected on all T cells but not on other cells in peripheral blood, with the possible exception of a small subpopulation (about 5%) of B cells, as assessed by indirect immunofluorescence and flow cytometry. HT23A labelled T cell areas of horse lymph nodes and spleen when used in an indirect immunoperoxidase assay on frozen sections. Macrophages and neutrophils were not labelled by the antibody nor were frozen sections of horse liver, kidney, or brain. HT23A precipitated a molecule of approximately 69 kDa from 125Iodine labelled horse lymphocytes.

At least two loci encode polymorphic class I MHC antigens in the horse

Six monoclonal antibodies and ten alloantisera were used to precipitate cell surface molecules of approximately 44 kDa (class I MHC antigens) from radiolabelled equine peripheral blood lymphocytes. All ten antisera were raised against antigens of a single donor horse (horse 0834, ELA-A2,-A2). Four methods of producing antisera were compared: one or two pregnancies, skin allografting, and skin grafting followed by pregnancy. Immunization by pregnancy appeared to produce antibodies against class I products only, while skin grafting raised antibodies to class II antigens as well. Nine of the antisera were raised across an entire MHC haplotype barrier, while one recipient carried the ELA-A2 antigen of the donor. The pregnancy antiserum raised across this barrier probably identifies a second polymorphic class I locus in the horse. Sequential immunoprecipitation using this antiserum in the first stage and an anti-MHC haplotype antiserum or monoclonal antibody reagent in the second stage supported this hypothesis. Gene products of this second ELA class I locus are immunogenic in pregnancy.

The cholesterol transport inhibitor U18666a regulates amyloid precursor protein metabolism and trafficking in N2aAPP "Swedish" cells

Cholesterol transport is a key regulator of amyloid precursor protein (APP) processing and beta-amyloid (Abeta production, implicated in Alzheimer's disease. Perturbation of cholesterol transport can be pharmacologically induced by the class II amphiphile 3-beta-[2-(diethylamino)ethoxy]androst-5-en-17-one, U18666a; however, the mechanisms by which U18666a controls APP metabolism and trafficking have not been elucidated. We proposed to determine how U18666a regulates APP holoprotein metabolism and trafficking in N2a mouse neuroblastoma cells stably expressing the human APP protein. Secretion of Abeta1-40 was reduced in U18666a-treated cells. U18666a elevated the steady state level of the APP holoprotein but not APP mRNA levels. U18666a increased sAPPalpha secretion and intracellular alpha-CTF/C83 levels but intracellular betaCTF/C99 levels were reduced. The increase in APP protein level was due to decreased catabolism rather than increased APP synthesis. Interestingly, U18666a regulated APP trafficking and increased the level of the holoprotein at the cell surface for alpha-secretase processing and reduced internalization for beta-secretase processing. These data demonstrate that U18666a effects on cholesterol transport function to regulate amyloid precursor protein metabolism and trafficking.

Pre-ischemic exercise reduces matrix metalloproteinase-9 expression and ameliorates blood-brain barrier dysfunction in stroke

Exercise reduces ischemia and reperfusion (I/R) injury in the rat stroke model. We investigated whether pre-ischemic exercise ameliorates blood-brain barrier (BBB) dysfunction in stroke by reducing matrix metalloproteinase (MMP)-9 expression and strengthening basal lamina. Adult male Sprague-Dawley rats were subjected to a 30 min exercise program on a treadmill 5 days a week for 3 weeks. Stroke was induced by a 2-h middle cerebral artery (MCA) occlusion using an intraluminal filament in the exercised and non-exercised groups. Brain infarction was measured and neurological deficits were scored. BBB dysfunction was determined by examining brain edema and Evans Blue extravasation. Expression of collagen IV, the major component of basal lamina essential for maintenance of the endothelial permeability barrier, was quantitatively detected by Western blot and immunocytochemistry. Ex vivo techniques were used to compare collagen IV-labeled vessels in response to ischemic insult. Temporal relationship of expression of MMP-9 and its endogenous inhibitor, the tissue inhibitors of metalloproteinase-1 (TIMP-1), was determined by real-time PCR for mRNA and Western blot for protein during reperfusion. Brain edema and Evans Blue leakage were both significantly (P<0.01) reduced after stroke in the exercised group, in association with reduced brain infarct volume and neurological deficits. Western blot analysis indicated that exercise enhanced collagen IV expression and reduced the collagen loss after stroke. Immunocytochemistry demonstrated that collagen IV-labeled vessels were significantly (P<0.01) increased in exercised rats. In the ex vivo study, after exercised brains were incubated with ischemic brain tissue, a significantly (P<0.01) higher level of collagen IV-labeled vessels was observed as compared with non-exercised brains following the same treatment. The ex vivo study also revealed a key role of MMP-9 in exercise-strengthened collagen IV expression against I/R injury. TIMP-1 protein levels were significantly (P<0.01) increased by exercise. Our results indicate that pre-ischemic exercise reduces brain injury by improving BBB function and enhancing basal lamina integrity in stroke. This study suggests that the neuroprotective effect of physical exercise is associated with an imbalance of MMP-9 and TIMP-1 expression.

PROPHYLACTIC ADMINISTRATION OF PONAZURIL REDUCES CLINICAL SIGNS AND DELAYS SEROCONVERSION IN HORSES CHALLENGED WITH SARCOCYSTIS NEURONA

The ability of ponazuril to prevent or limit clinical signs of equine protozoal myeloencephalitis (EPM) after infection with Sarcocystis neurona was evaluated. Eighteen horses were assigned to 1 of 3 groups: no treatment, 2.5 mg/kg ponazuril, or 5.0 mg/kg ponazuril. Horses were administered ponazuril, once per day, beginning 7 days before infection (study day 0) and continuing for 28 days postinfection. On day 0, horses were stressed by transport and challenged with 1 million S. neurona sporocysts per horse. Sequential neurologic examinations were performed, and serum and cerebrospinal fluid were collected and assayed for antibodies to S. neurona. All horses in the control group developed neurologic signs, whereas only 71 and 40% of horses in the 2.5 and 5.0 mg/kg ponazuril groups, respectively, developed neurologic abnormalities. This was significant at P = 0.034 by using Fisher exact test. In addition, seroconversion was decreased in the 5.0 mg/kg group compared with the control horses (100 vs. 40%; P = 0.028). Horses with neurologic signs were killed, and a post-mortem examination was performed. Mild-to-moderate, multifocal signs of neuroinflammation were observed. These results confirm that treatment with ponazuril at 5.0 mg/kg minimizes, but does not eliminate, infection and clinical signs of EPM in horses.

Analysis of air contrast barium enema, computed tomographic colonography, and colonoscopy: prospective comparison

BACKGROUND

The usefulness of currently available colon imaging tests, including air contrast barium enema (ACBE), computed tomographic colonography (CTC), and colonoscopy, to detect colon polyps and cancers is uncertain. We aimed to assess the sensitivity of these three imaging tests.

METHODS

Patients with faecal occult blood, haematochezia, iron-deficiency anaemia, or a family history of colon cancer underwent three separate colon-imaging studies--ACBE, followed 7-14 days later by CTC and colonoscopy on the same day. The primary outcome was detection of colonic polyps and cancers. Outcomes were assessed by building an aggregate view of the colon, taking into account results of all three tests.

FINDINGS

614 patients completed all three imaging tests. When analysed on a per-patient basis, for lesions 10 mm or larger in size (n=63), the sensitivity of ACBE was 48% (95% CI 35-61), CTC 59% (46-71, p=0.1083 for CTC vs ACBE), and colonoscopy 98% (91-100, p<0.0001 for colonoscopy vs CTC). For lesions 6-9 mm in size (n=116), sensitivity was 35% for ACBE (27-45), 51% for CTC (41-60, p=0.0080 for CTC vs ACBE), and 99% for colonoscopy (95-100, p<0.0001 for colonoscopy vs CTC). For lesions of 10 mm or larger in size, the specificity was greater for colonoscopy (0.996) than for either ACBE (0.90) or CTC (0.96) and declined for ACBE and CTC when smaller lesions were considered.

INTERPRETATION

Colonoscopy was more sensitive than other tests, as currently undertaken, for detection of colonic polyps and cancers. These data have important implications for diagnostic use of colon imaging tests.

US physicians' attitudes toward genetic testing for cancer susceptibility

Genetic testing for an inherited susceptibility to cancer is an emerging technology in medical practice. Little information is currently available about physicians' attitudes toward these tests. To assess US physicians' opinions on unresolved issues surrounding genetic testing, a 15-min survey was administered to a stratified random sample of 1,251 physicians from 8 specialties, selected from a file of all licensed physicians in the US (response rate = 71.0%). Dependent measures included physicians' attitudes toward genetic counseling and testing qualifications, availability of guidelines, patient confidentiality and insurance discrimination issues, and clinical utility of genetic tests. More than 89% of physicians reported a need for physician guidelines, 81% thought that patients with positive genetic test results are at risk for insurance discrimination, and more than 53% thought that it was difficult to ensure the confidentiality of test results. Almost 25% indicated that genetic tests for cancer susceptibility have too many inaccurate or ambiguous results; nearly 75% thought that clear guidelines are not available for managing patients with positive test results. Only 29% of physicians reported feeling qualified to provide genetic counseling to their patients. More than 84% of oncologists considered themselves qualified to recommend genetic testing to their patients compared with 40% of primary care physicians (PCPs), and 57% of tertiary care physicians (TCPs). US physicians expressed great uncertainty about issues surrounding genetic testing for cancer susceptibility. Results of this national survey underscore the need to provide physicians with clear guidelines on the use of genetic cancer susceptibility tests and effective medical training on their appropriate implementation.