CB1 receptor expression and signaling are required for dexamethasone-induced aversive memory consolidation

The molecular processes that underlie long-term memory formation involve signaling pathway activation by neurotransmitter release, which induces the expression of immediate early genes, such as Zif268, having a key role in memory formation. In this work, we show that the cannabinoid CB1 receptor signaling is necessary for the effects of dexamethasone on the behavioral response in an inhibitory avoidance task, on dexamethasone-induced ERK phosphorylation, and on dexamethasone-dependent Zif268 expression. Furthermore, we provide primary evidence for the mechanism responsible for this crosstalk between cannabinoid and glucocorticoid-mediated signaling pathways, showing that dexamethasone regulates endocannabinoid metabolism by inhibiting the activity of the Fatty acid amide hydrolase (FAAH), an integral membrane enzyme that hydrolyzes endocannabinoids and related amidated signaling lipids. Our results provide novel evidence regarding the role of the endocannabinoid system, and in particular of the CB1 receptor, as a mediator of the effects of glucocorticoids on the consolidation of aversive memories.

P5996HDAC inhibition improves myofibrillar relaxation and metabolism in a feline model of HFpEF

Background

Heart failure (HF) with preserved ejection fraction (HFpEF) accounts for about 50% of all cases of HF and there are currently no effective therapies.

Purpose

To assess the effects of histone deacetylase (HDAC) inhibition on cardiac and mitochondrial function and the plasma metabolome in a large mammalian model of slow-progressive pressure overload with features of HFpEF.

Methods

Male domestic short hair cats (n=26, aged 2mo), underwent either sham (S) procedures (n=5) or aortic constriction with a customized pre-shaped band (n=21), resulting in slow progressive pressure overload during growth. 2 months post-banding, animals were treated daily with either 10mg/kg suberoylanilide hydroxamic acid (b+SAHA) (n=8), a pan-HDAC inhibitor, or vehicle (b+veh) (n=8) for 2 months. Serial in-vivo cardiopulmonary phenotyping was performed monthly, and invasive hemodynamic and gas exchange parameters were evaluated 4 months post-banding. Ex-vivo myofibril mechanical studies and blood-based metabolomic profiling were performed. Data is presented as mean±SEM.

Results

Echocardiography at 4-months post-banding revealed that b+SAHA animals had a significant reduction in left ventricular hypertrophy (LVH) and LA size vs. b+veh animals. Left ventricular end-diastolic pressure (LVEDP) and mean pulmonary arterial pressure (mPAP) were significantly lower in b+SAHA vs. b+veh. SAHA treatment also improved ex-vivo myofibril relaxation independent of LVH and this effect correlated with in-vivo improvements of LV relaxation. Furthermore, SAHA treatment preserved lung structure, and improved lung compliance and oxygenation, reflected by a decrease in alveolar-capillary wall thickness and intrapulmonary shunt. SAHA treatment also reduced perivascular fluid cuffs around extra-alveolar vessels, suggesting attenuated alveolar-capillary stress failure. Treatment with SAHA caused an increase in both oxygen consumption in-vivo and the percentage of type 1 skeletal muscle fibers (higher oxidative capacity). SAHA also increased mRNA levels of coactivators that regulate mitochondrial function and induced metabolic reprogramming towards mitochondrial oxidation preferentially utilizing fatty acids. SAHA treated HeLa cells showed a significant increase in oxidative phosphorylation and ATP production.

Effects of SAHA

Conclusion

These results show that slow-progressive pressure overload mimics critical features of HFpEF. SAHA can improve cardiac, pulmonary, and metabolic derangements caused by chronic pressure overload. Therefore, HDAC inhibition may be an interesting therapeutic strategy to treat the ever growing HFpEF population.

Acknowledgement/Funding

NIH [HL33921 to S.R.H, HL116848, HL127240 to T.A.M]; AHA [16SFRN31400013 to T.A.M.]; Medical University of Graz [M.W.], Stadt Graz [M.W.]

Abstract P1-20-03: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Dillon SR, Evans LS, Rickel E, Lewis KE, Swanson R, Levin SD, Wolfson M, Peng SL, Swiderek KM. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-20-03.

Public Health Mode Personalized Medicine: Risk Stratification for Breast Cancer Screening

Background: Breast cancer (BC) screening, primarily age-based, is a major public health program in many wealthy countries. At the same time, there is a dramatic increase in using genetics to support personalized medicine. These two approaches would seem antithetical. However, they can join powerfully with the possibility of using genetic information as the basis for a major shift from age-based to a risk-based BC screening programs. Aim: To assess the prospective cost-effectiveness of such a shift to risk-based BC screening requires representative population data on the relationships among a woman's age when a risk assessment is done, her family history of cancer in the context of pedigree data, and specific features of her genotype - comprising both the presence of rare genetic mutations like BRCA1/2 and recently derived polygenic risk scores. We use our newly developed Genetic Mixing Model (GMM) to estimate this joint distribution as the initial step in assessing the prospective cost-effectiveness of risk stratified BC screening in Canada. Methods: BOADICEA is a BC risk stratification algorithm already in wide use around the world, and in particular in Ontario, for high risk screening. A new version of BOADICEA incorporating a polygenic risk score has recently (will have) been published. We embedded the new core BOADICEA algorithm into the GMM. GMM thus provides the empirical foundation for assessing risk stratification for a representative population by constructing an estimate of the multivariate joint distribution of family history, presence of rare genetic mutations including BRCA1/2, and a polygenic risk score, derived from genome-wide association studies. Results: Using a polygenic risk score (PRS) would be far more useful for stratifying women according to their risk of breast cancer than the two most commonly used indicators at present: family history and rare genetic mutations. We have assessed a variety of combinations of these genetic indicators, in combination with offering universal risk assessment to women in Canada at various ages, and using different thresholds for categorizing women as being at high risk. The optimal age for risk assessment is in the 35 to 40 range. And the PRS is substantially more useful than family history or rare mutations for stratifying women for screening intensity by their risk of BC. Conclusion: Shifting from the current public health approach of primarily age-based screening for breast cancer, to one based on risk stratification, especially making use of recent advances in assessing polygenic risk, offers major potential benefits.

The OncoSim Cancer Simulation Platform: A Tool to Project the Population Effects of Cancer Control Interventions in Canada

Background: Cancer control interventions exert their effects over multiple decades. To evaluate diverse and competing opportunities to reduce future cancer burden it is desirable to understand long-term effects prior to any new program implementation or significant change. Internationally, modeling is becoming an accepted source of planning information for decision-makers. Aim: We will describe the construction and use of the OncoSim microsimulation model, which was developed to evaluate cancer control strategies in Canada. Methods: OncoSim is a suite of models (cancers of the lung, colorectum, cervix and breast, plus a composite 32-cancer model) used to address key policy questions and support decision-making. It is led by the Canadian Partnership Against Cancer with model development by Statistics Canada. OncoSim incorporates risk factors, cancer natural history, screening, treatment, survival and end-of-life care. Wherever possible it is informed by Canadian data sources. Models are calibrated to reproduce a range of cancer-specific statistics, e.g., current and historical Canadian cancer-specific incidence and mortality, smoking patterns, and results of screening. The site-specific models have undergone further validation by replicating reported short-term effects of cancer prevention and screening interventions. Users may customize interventions through modifying input parameters. Outputs include incidence, mortality, costs, cost-effectiveness, and resource utilization. Users from the public sector have access at no cost to OncoSim and receive extensive support from a multidisciplinary technical team. The model is continually updated to incorporate emerging knowledge. Results: OncoSim has been used to support cancer control decision-making at the national and provincial/territorial levels. Applications include: national guidelines recommendations for colorectal and lung cancer screening; comparison of cytology vs. HPV based cervical cancer screening; and integration of smoking cessation into low-dose CT lung cancer screening. Conclusion: Validated simulation models such as OncoSim can be a versatile and efficient tool for cancer control planners to evaluate and prioritize cancer control strategies.

Variability in the primary emissions and secondary gas and particle formation from vehicles using bioethanol mixtures

Bioethanol for use in vehicles is becoming a substantial part of global energy infrastructure because it is renewable and some emissions are reduced. Carbon monoxide (CO) emissions and total hydrocarbons (THC) are reduced, but there is still controversy regarding emissions of nitrogen oxides (NO_x), aldehydes, and ethanol; this may be a concern because all these compounds are precursors of ozone and secondary organic aerosol (SOA). The amount of emissions depends on the ethanol content, but it also may depend on the engine quality and ethanol origin. Thus, a photochemical chamber was used to study secondary gas and aerosol formation from two flex-fueled vehicles using different ethanol blends in gasoline. One vehicle and the fuel used were made in the United States, and the others were made in Brazil. Primary emissions of THC, CO, carbon dioxide (CO₂), and nonmethane hydrocarbons (NMHC) from both vehicles decreased as the amount of ethanol in gasoline increased. NO_x emissions in the U.S. and Brazilian cars decreased with ethanol content. However, emissions of THC, CO, and NO_x from the Brazilian car were markedly higher than those from the U.S. car, showing high variability between vehicle technologies. In the Brazilian car, formation of secondary nitrogen dioxide (NO₂) and ozone (O₃) was lower for higher ethanol content in the fuel. In the U.S. car, NO₂ and O₃ had a small increase. Secondary particle (particulate matter [PM]) formation in the chamber decreased for both vehicles as the fraction of ethanol in fuel increased, consistent with previous studies. Secondary to primary PM ratios for pure gasoline is 11, also consistent with previous studies. In addition, the time required to form secondary PM is longer for higher ethanol blends. These results indicate that using higher ethanol blends may have a positive impact on air quality.

IMPLICATIONS

The use of bioethanol can significantly reduce petroleum use and greenhouse gas emissions worldwide. Given the extent of its use, it is important to understand its effect on urban pollution. There is a controversy on whether there is a reduction or increase in PM emission when using ethanol blends. Primary emissions of THC, CO, CO₂, NO_x, and NMHC for both cars decreased as the fraction of ethanol in gasoline increased. Using a photochemical chamber, the authors have found a decrease in the formation of secondary particles and the time required to form secondary PM is longer when using higher ethanol blends.

Abstract P1-09-10: ICOSL anti-HER2 V-mAbs: Localizing engineered ICOSL costimulatory agonists to HER2+ tumors through trastuzumab

Background: The presence of tumor infiltrating lymphocytes (TILs) has been associated with improved prognosis in HER2+ breast cancer patients. Antigen specific TCR and costimulatory receptor signaling drive increases in TIL number, effector function, and tumor cytotoxicity. Improving the number and effector phenotype of tumor localized TILs has curative potential by enhancing the adaptive and memory immune response. Targeting HER2 with the monoclonal anti-HER2 antibody trastuzumabhas improved survival in HER2+ breast cancer patients and is known to increase peripheral type I immunity, which may be reflected by increased TILs.

The Immunoglobulin Superfamily (IgSF) includes a large, diverse family of immunotherapy targets expressed on immune cells and tumors. Transmembrane IgSF receptors,CD28 and inducible T cell co-stimulator (ICOS), related costimulatory molecules expressed on T cells, interact with CD80/CD86 and ICOS ligand (ICOSL), respectively, and play critical roles in T cell activation and adaptive immunity.The Alpine Immune Science's VIgDTM platform uses directed evolution to derive novel, therapeutically-applicable IgSF extracellular domains with tailored specificity and affinity. The vIgD platform has generated human ICOSL vIgDs capable of binding both ICOS and CD28, activating both pathways. To promote anti-tumor activity of TILs in HER2+ tumors, we developed trastuzumab-ICOSL “V-mAbs” consisting of trastuzumab fused to activating ICOSL vIgDs. These V-mAbs are designed to localize to HER2+ tumors and activate antigen-specific, resident T-cells through costimulatory receptor agonism.

Methods: V-mAbs were generated by fusing ICOSL vIgDs to either the N- or C- termini of the heavy and/or light chains of trastuzumab. V-mAb binding to CD28, ICOS or HER2 was measured by flow cytometric analysis of transfected cells or ForteBio analysis. V-mAb costimulatory activity was confirmed by immobilization in the presence of anti-CD3 in a primary human T cell assay. Finally, V-mAbs were co-cultured with HER2+ target cells and human T cells; T-cell activity was measured by proliferation, cytokine production, and target lysis.

Results: V-mAbs were successfully produced and bound to CD28, ICOS and HER2. In a plate bound costimulation assay, the V-mAbs increased the amount of IFN-gamma produced by T-cells stimulated with anti-CD3. When incubated with HER2+ target cells, V-mAbs promoted T-cell proliferation, cytokine secretion, and target cell lysis. Data from in vivo studies, to determine the impact of trastuzumab V-mAbs on HER2+ cancers, will be presented when available.

Conclusions: Trastuzumab-ICOSL V-mAbs are novel ICOS- and CD28-activating immunotherapies for HER2-positive tumors, promoting T-cell proliferation, cytokine secretion, and target cell lysis in a HER2 dependent fashion. The V-mAb platform has broad potential to enable tumor-localized immune modulation via the diverse array of IgSF members. Preclinical development of trastuzumab-ICOSL clinical therapeutics is in progress.

Citation Format: Rickel E, Evans L, Swanson R, Levin SS, Rixon M, Wolfson M, Bhandari J, MacNeil S, Hoover J, Kornacker M, Capuano I, Peng SL. ICOSL anti-HER2 V-mAbs: Localizing engineered ICOSL costimulatory agonists to HER2+ tumors through trastuzumab [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-09-10.

The OncoSim model: development and use for better decision-making in Canadian cancer control

The Canadian Partnership Against Cancer was created in 2007 by the federal government to accelerate cancer control across Canada. Its OncoSim microsimulation model platform, which consists of a suite of specific cancer models, was conceived as a tool to augment conventional resources for population-level policy- and decision-making. The Canadian Partnership Against Cancer manages the OncoSim program, with funding from Health Canada and model development by Statistics Canada. Microsimulation modelling allows for the detailed capture of population heterogeneity and health and demographic history over time. Extensive data from multiple Canadian sources were used as inputs or to validate the model. OncoSim has been validated through expert consultation; assessments of face validity, internal validity, and external validity; and model fit against observed data. The platform comprises three in-depth cancer models (lung, colorectal, cervical), with another in-depth model (breast) and a generalized model (25 cancers) being in development. Unique among models of its class, OncoSim is available online for public sector use free of charge. Users can customize input values and output display, and extensive user support is provided. OncoSim has been used to support decision-making at the national and jurisdictional levels. Although simulation studies are generally not included in hierarchies of evidence, they are integral to informing cancer control policy when clinical studies are not feasible. OncoSim can evaluate complex intervention scenarios for multiple cancers. Canadian decision-makers thus have a powerful tool to assess the costs, benefits, cost-effectiveness, and budgetary effects of cancer control interventions when faced with difficult choices for improvements in population health and resource allocation.

Using the Cancer Risk Management Model to evaluate colorectal cancer screening options for Canada

BACKGROUND

Several screening methods for colorectal cancer (crc) are available, and some have been shown by randomized trials to be effective. In the present study, we used a well-developed population health simulation model to compare the risks and benefits of a variety of screening scenarios. Tests considered were the fecal occult blood test (fobt), the fecal immunochemical test (fit), flexible sigmoidoscopy, and colonoscopy. Outcomes considered included years of life gained, crc cases and deaths prevented, and direct health system costs.

METHODS

A natural history model of crc was implemented and calibrated to specified targets within the framework of the Cancer Risk Management Model (crmm) from the Canadian Partnership Against Cancer. The crmm-crc permits users to enter their own parameter values or to use program-specified base values. For each of 23 screening scenarios, we used the crmm-crc to run 10 million replicate simulations.

RESULTS

Using base parameter values and some user-specified values in the crmm-crc, and comparing our screening scenarios with no screening, all screening scenarios were found to reduce the incidence of and mortality from crc. The fobt was the least effective test; it was not associated with lower net cost. Colonoscopy screening was the most effective test; it had net costs comparable to those for several other strategies considered, but required more than 3 times the colonoscopy resources needed by other approaches. After colonoscopy, strategies based on the fit were predicted to be the most effective. In sensitivity analyses performed for the fobt and fit screening strategies, fobt parameter values associated with high-sensitivity formulations were associated with a substantial increase in test effectiveness. The fit was more cost-effective at the 50 ng/mL threshold than at the 100 ng/mL threshold.

CONCLUSIONS

The crmm-crc provides a sophisticated and flexible environment in which to evaluate crc control options. All screening scenarios considered in this study effectively reduced crc mortality, although sensitivity analyses demonstrated some uncertainty in the magnitude of the improvements. Where possible, local data should be used to reduce uncertainty in the parameters.

Inflammatory agents involved in septic miscarriage

Even though the understanding of the cause of early pregnancy loss due to chromosomal abnormalities has improved, there is a dearth of knowledge of the causes of loss in euploid conceptuses. Maternal infections are a cause of abort in humans, but the mechanisms are not clear, so we have developed a murine model to study the mechanism of septic abortion by inducing embryonic resorption (ER) with lipopolysaccharide (LPS). We demonstrated that augmented production of nitric oxide (NO) and prostaglandins (PG) is involved in ER, and that inhibitors of their synthesis could prevent ER. Also, we observed an increase in the oxidative damage, evidenced by nitration of tyrosine proteins, due to the peroxynitrite anion. Since an association between chronic marijuana smoking and early miscarriage has been shown in women, we studied the participation of anandamide (AEA), the principal endocannabinoid, on the mechanism of action of LPS. We showed that LPS-induced NO synthesis and tissue damage were mediated by AEA, and that this endotoxin inhibited AEA degradation and increased its synthesis. These results suggest that several inflammatory molecules participate in the mechanism of early pregnancy loss and that their modulation could be useful tools to prevent it.

Remyelination after cuprizone-induced demyelination in the rat is stimulated by apotransferrin

Twenty-one-day-old Wistar rats were fed a diet containing 0.6% cuprizone for 2 weeks. Studies carried out after withdrawal of cuprizone showed histological evidences of marked demyelination in the corpus callosum. Biochemical studies of isolated myelin showed a marked decrease in myelin proteins, phospholipids, and galactocerebrosides as well as a marked decrease in myelin yield. Treatment of these animals with a single intracranial injection of 350 ng of apotransferrin at the time of withdrawal of cuprizone induced a marked increase in myelin deposition resulting in a significantly improved remyelination, evaluated by histological, immunocytochemical, and biochemical parameters, in comparison to what was observed in spontaneous recovery. Immunocytochemical studies of cryotome sections to analyze developmental parameters of the oligodendroglial cell population at the time of termination of cuprizone and at different times thereafter showed that in the untreated animals, there was a marked increase in the number of NG2-BrdU-positive precursor cells together with a marked decrease in MBP expression at the peak of cuprizone-induced demyelination. As expected, the amount of precursor cells decreased markedly during spontaneous remyelination and was accompanied by an increase in MBP reactivity. In the apotransferrin-treated animals, these phenomena occurred much faster, and remyelination was much more efficient than in the untreated controls. The results of this study suggest that apotransferrin is a very active promyelinating agent which could be important for the treatment of certain demyelinating conditions.

Labour market income inequality and mortality in North American metropolitan areas

OBJECTIVE

To investigate relations between labour market income inequality and mortality in North American metropolitan areas.

METHODS

An ecological cross sectional study of relations between income inequality and working age (25-64 years) mortality in 53 Canadian (1991) and 282 US (1990) metropolitan areas using four measures of income inequality. Two labour market income concepts were used: labour market income for households with non-trivial attachment to the labour market and labour market income for all households, including those with zero and negative incomes. Relations were assessed with weighted and unweighted bivariate and multiple regression analyses.

RESULTS

US metropolitan areas were more unequal than their Canadian counterparts, across inequality measures and income concepts. The association between labour market income inequality and working age mortality was robust in the US to both the inequality measure and income concept, but the association was inconsistent in Canada. Three of four inequality measures were significantly related to mortality in Canada when households with zero and negative incomes were included. In North American models, increases in earnings inequality were associated with hypothetical increases in working age mortality rates of between 23 and 33 deaths per 100 000, even after adjustment for median metropolitan incomes.

CONCLUSIONS

This analysis of labour market inequality provides more evidence regarding the robust nature of the relation between income inequality and mortality in the US. It also provides a more refined understanding of the nature of the relation in Canada, pointing to the role of unemployment in generating Canadian metropolitan level health inequalities.

[Heat shock proteins and malignancies of the female genital tract]

Heat shock proteins (Hsp) are cytoplasmic proteins that act as molecular chaperones for protein molecules in various intra-cellular processes. They play an important role in protein-protein interactions, including folding and conformation, and prevention of inappropriate protein aggregation. They are called "heat shock proteins" since they were first discovered in cells exposed to high temperatures. However, their synthesis is also accentuated under other stress conditions, such as exposure of the cell to inflammation, infection, ischemia, toxins, cytotoxic drugs and malignant transformation. Hsp have been classified into families according to their molecular weight. In ovarian carcinoma, over-expression of Hsp27 was associated with increased resistance to chemotherapy and a worse prognosis. In endometrial carcinoma, over-expression of Hsp70 was associated with poorly differentiated tumors and a worse prognosis, whereas over-expression of Hsp27 and Hsp90 were associated with well-differentiated tumors and better prognosis. The association between increasing expression of Hsp90 and better differentiation and prognosis seems to reflect high levels of sex steroid receptors in well-differentiated endometrial carcinomas. In cervical carcinoma, the presence of Hsp70 was associated with a worse outcome. Since Hsp are highly antigenic, their property to bind with tumor proteins and proteins produced by viruses may be used for the development of vaccines against cancers and viral diseases. It is speculated that examination of the lower genital tract secretions for IgA antibodies against Hsp will contribute to early detection of malignancies. Since Hsp may affect the growth of the tumor and its response to chemotherapy, it is speculated that using drugs that inhibit Hsp in combination with conventional chemotherapy may contribute to the improvement of the treatment results.

Taxol-induced apoptosis in human SKOV3 ovarian and MCF7 breast carcinoma cells is caspase-3 and caspase-9 independent

Taxol is used in chemotherapy regimens against breast and ovarian cancer. Treatment of tumor model cell lines with taxol induces apoptosis, but exact mechanism is not sufficiently understood. Our results demonstrate that in response to taxol, various cell types differentially utilize distinct apoptotic pathways. Using MCF7 breast carcinoma cells transfected with caspase-3 gene, we showed that taxol-induced apoptosis occurred in the absence of caspase-3 and caspase-9 activation. Similar results were obtained with ovarian SKOV3 carcinoma cells, expressing high level of endogenous caspase-3. In contrast, staurosporine-induced apoptosis in these cells was accompanied by proteolytic cleavage of pro-caspase-3 and induction of caspase-3 enzymatic activity. The effect of taxol appears to be cell type-specific, since taxol-induced apoptosis in leukemia U937 cells involved caspase-3 activation step. We conclude that a unique caspase-3 and caspase-9 independent pathway is elicited by taxol to induce apoptosis in human ovarian and breast cancinoma cells.

Activation of HTLV-I long terminal repeat by stress-inducing agents and protection of HTLV-I-infected T-cells from apoptosis by the viral tax protein

HTLV-I is etiologically implicated with tropical spastic paraparesis/HTLV-I associated myelopathy, adult T-cell leukemia and certain other diseases. However, after infection the virus enters into a dormant state, whereas the characteristics of the HTLV-I related diseases indicate that their genesis requires activation of the dormant virus by a Tax-independent mechanism. In the present study we demonstrate that a variety of stress-inducing agents (TPA, cisplatin, etoposide, taxol, and 3-methylcholanthrene) are capable of Tax-independent activation of HTLV-I LTR and that this activation is detected mainly in cells that are undergoing through the apoptotic process. Furthermore, it is demonstrated that both apoptosis induction and HTLV-I LTR activation are inhibited by Bcl-2 and by PKC, indicating that these two processes are mechanistically cross-linked. In addition, using an HTLV-I producing human T-cell line which permanently express the negatively transdominant tax mutant, Delta58tax, under the Tet-Off control system, we prove that the virally encoded Tax protein protects the host cells from apoptosis. Together, these data suggest that activation of the dormant virus in the carriers' infected T-cells by certain stress-inducing conditions and protecting these cells from the consequent apoptotic death by the viral Tax protein emerging after this activation, might be the basis for switching the virus from latency to a pathogenic phase.

The role of ERK 1/2 and p38 MAP-kinase pathways in taxol-induced apoptosis in human ovarian carcinoma cells

Taxol is an anticancer agent of natural origin with significant activity against a number of human cancers including ovarian and breast carcinomas. Its cytotoxic activity has been attributed to its ability to stabilize microtubules and to promote microtubule assembly. Recently it has become clearer that Taxol has additional activities including effects in cell signaling and gene expression. We have shown previously that Taxol activates ERK 1/2 MAP-kinases and results in the formation of GRB2/SHC complexes in murine macrophage-like RAW 267.4 cells. Here we demonstrate that Taxol activates ERK 1/2 and p38 MAP-kinases in human ovarian carcinoma cells with distinct kinetics. Activation of ERK1/2 has been observed at low concentrations of Taxol (1-100 nM) within 0.5-6 h, whereas longer exposure(24 h) to nanomolar concentrations of Taxol resulted in an abrogation of the ERK1/2 phosphorylation/activation. Higher concentrations (1-10 microM) resulted in a sharp inhibition of ERK1/2 activity. p38 kinase was activated by high concentrations (1-10 microM) of Taxol within 2 h and remained active for more than 24 h. The kinetic studies showed that these effects of Taxol coincided with an inhibition of proliferation, and the onset of apoptosis. The appearance of the fragmented chromatin visualized by DAPI staining, and DNA fragments seen on an agarose gel, coincided with the decrease in ERK1/2 activation and concomitant increase of the level of active p38 MAPK. The inhibitor PD98059 abrogated ERK 1/2 activation and increased the cytotoxic effect of Taxol. An inhibitor of p38 kinase, SB203580, protected the cells partially from Taxol and, unexpectedly, activated ERK 1/2 kinases. We conclude that the alternative use of ERK1/2 and p38 MAP-kinase pathways may be necessary for the transition from proliferation state to Taxol-induced apoptosisin human ovarian carcinoma cells.

Aurintricarboxylic acid decreases proliferative potential of SKOV3 and MCF7 human carcinoma cells

The effect of aurintricarboxylic acid (ATA) on cell growth and proliferative capacity was studied in human ovarian SKOV3 and breast MCF7 carcinoma cells. ATA moderately inhibited cell growth measured by a Neutral red assay after a 24-hour incubation of the cells in the presence of ATA. The ATA-treated cells displayed a markedly decreased capacity to proliferate, as was evident from a colony formation assay. The initial and delayed anti-proliferative effects of ATA were dose-dependent. Together, the results indicated that ATA offers the potential of being recognized as an anti-tumor drug, at least in certain types of cancers.

On measuring inequalities in health

In a recent series of papers, Murray et al. have put forward a number of important ideas regarding the measurement of inequalities in health. In this paper we agree with some of these ideas but draw attention to one key aspect of their approach--measuring inequalities on the basis of small area data--which is flawed. A numerical example is presented to illustrate the problem. An alternative approach drawing on longitudinal data is outlined, which preserves and enhances the most desirable aspects of their proposal. These include the use of a life course perspective, and the consideration of non-fatal health outcomes as well as the more usual information on mortality patterns.

Preliminary findings from the National Pre-ESRD Education Initiative

Regardless of age or race, more patients preferred peritoneal dialysis (PD) than would be expected from the current ratio of patients treated with PD in the U.S. The percent of patients choosing PD seems to be largely influenced by the scope of information they receive prior to therapy initiation. In the absence of thorough treatment option education, a significant number of patients may be assigned a therapy when, in reality, they would have selected an alternative option. There is a need to further understand the correlation between a practice's PD utilization rate and the extent to which patients are given dialysis treatment options.

Exposure to violence and victimization, depression, substance use, and the use of violence by young adolescents

OBJECTIVE

To examine the relationships among exposure to violence; tobacco, alcohol, and other substance use; depression; church attendance; and the use of violence among very young adolescents.

METHODS

An 86-item confidential questionnaire was administered to 722 sixth grade students (mean age = 11.9+/-0.8 years) attending 4 middle schools serving neighborhoods in and around public housing.

RESULTS

Boys had a higher mean violence scale score than girls (P < or =.0001), and students living in public housing had higher violence scale scores than other students (P< or =.0001). Self-reported use of violence was significantly associated with exposure to violence (r =.45); age (r =.28); frequency of church attendance (r = -.14); depression (r =.28); the probability of being alive at age 25 (r = -.09); the frequency of use of cigarettes (r =.39), alcohol (r =.37), and multiple substances (r =.38); and interest in a gang (r =.37). When all of these variables were analyzed with multiple linear regression, multiple substance use, exposure to violence, interest in a gang, male gender, cigarette smoking, and depression level accounted for 49.7% of the variation in the use of violence scale.

CONCLUSION

Recent multiple substance use and lifetime exposure to violence and victimization were the strongest correlates with the frequency that these youth reported using violence and carrying weapons.

Detection of tumor mutant APC DNA in plasma of patients with sporadic colorectal cancer

The aim of this study was to detect mutant APC DNA of tumor origin in the plasma of patients with sporadic colorectal carcinomas. The polymerase chain reaction (PCR) and the single strand conformation polymorphism (SSCP) procedures were employed to detect DNA alterations using primers to amplify the mutation cluster region of the APC gene. APC mutations were observed in 7 out of 11 archival colonic tumor specimens examined. Matching mutations in free plasma DNA of tumor origin were detected in 3 of the 7 patients (42.8%). The results of this preliminary report indicated the presence of APC DNA in plasma harboring the identical abnormal molecular signature of tumor APC DNA. Detection methods of mutant APC DNA in blood may prove useful in the screening and monitoring of patients at risk of or with colorectal cancer.

A model of inositol compartmentation in astrocytes based upon efflux kinetics and slow inositol depletion after uptake inhibition

Intracellular compartmentation of inositol was demonstrated in primary cultures of mouse astrocytes, incubated in isotonic medium, by determination of efflux kinetics after "loading" with [3H]inositol. Three kinetically different compartments were delineated. The largest and most slowly exchanging compartment had a halflife of approximately 9 hr. This slow release leads to retention of a sizeable amount of pre-accumulated inositol in the tissue 24 hr after the onset of uptake inhibition, as confirmed by the observation that the inositol uptake inhibitor fucose caused a larger inhibition of unidirectional inositol uptake than of inositol pool size, measured as accumulated [3H]inositol after 24 hr of combined exposure to the inhibitor and the labeled isotope. Based upon the present observations and literature data, it is suggested that the large, slowly exchanging compartment is largely membrane-associated and participating in signaling via the phosphatidylinositide second messenger system, whereas inositol functioning as an osmolyte is distributed in the cytosol and located in one or both of the compartments showing a faster release.

Occupational attainment, smoking, alcohol intake, and marijuana use: ethnic-gender differences in the CARDIA study

OBJECTIVES

To evaluate the prospective interrelationship of smoking, alcohol intake, marijuana use, and educational and occupational attainment of Black and White young adults.

METHODS

Logistic or mixed model linear regression were used to evaluate relationships between self-reported substance use, ethnicity, gender, college graduation, and four measures of occupational attainment.

RESULTS

College graduation in the next 10 years was negatively associated with smoking and marijuana use, but not daily alcohol consumption in all ethnic and gender groups. In Whites, marijuana use was associated with less prestigious occupations and lower family income, while smoking was unrelated and moderate daily drinking was positively associated. In Blacks, marijuana use was generally unrelated to occupational measures, while smoking and daily alcohol consumption were negatively associated.

CONCLUSIONS

Relationships between smoking, marijuana use, daily drinking, and occupational attainment were not universally negative in this age group. Substance use, particularly smoking, is associated with reduced occupational attainment in Blacks compared with Whites after considering sociodemographic factors potentially limiting educational progression and occupational attainment.

Nordidemnin potently inhibits inositol uptake in cultured astrocytes and dose-dependently augments lithium's proconvulsant effect in vivo

It has been suggested that inositol uptake across the cell membrane is of importance for maintenance of the inositol pool involved in lithium's therapeutic effect in bipolar disease and in the lithium-pilocarpine seizure test in freely moving rats (measuring the latency of a normally subconvulsive concentration of pilocarpine to seizure induction in the additional presence of lithium). We have tested this hypothesis by: 1) demonstrating an extremely high potency of nordidemnin as an inhibitor of myo-inositol uptake in primary cultures of mouse astrocytes; and 2) determining the dose-response correlation of a nordidemnin-induced decrease in the latency before appearance of seizures in the lithium-pilocarpine test after intracerebroventricular injection of minute samples (10 microl) of virtually isotonic saline solution.

Chronic treatment of human astrocytoma cells with lithium, carbamazepine or valproic acid decreases inositol uptake at high inositol concentrations but increases it at low inositol concentrations

Inositol uptake was measured at concentrations of 25, 40 and 50 microM in human astrocytoma cell cultures treated for 1-3 weeks with pharmacologically relevant concentrations of LiCl, valproic acid or carbamazepine as well as in control cultures that had not been treated with any drug. After at least 2 weeks of treatment, each of these 3 conventional anti-bipolar drugs increased the uptake significantly at 25 microM inositol, had no effect at 40 microM, and decreased it at 50 microM inositol. Reduction of the drug concentrations by 50% abolished the stimulation of uptake at 25 microM inositol by lithium and valproic acid and reduced that by carbamazepine. These findings may contribute to an understanding of the mechanisms of action for anti-bipolar medication, and explain the controversy in the literature whether or not brain inositol is reduced after chronic administration of lithium.

Maternal obesity and pregnancy outcome

BACKGROUND

Obesity, a common condition in developed countries, is recognized as a threat to health.

OBJECTIVES

To describe the distribution of weight in pregnant women and evaluate the influence of obesity on pregnancy outcome in a high parity northern Israeli population.

METHODS

The study included 887 women who gave birth in the Western Galilee Medical Center during the period August to November 1995. The patients were classified as underweight, normal weight, overweight, or obese according to body mass index. Maternal demographic, obstetric, and perinatal variables were compared. A control group of 167 normal weight women were matched with the obese group for maternal age, parity, and gestational age.

RESULTS

Obese mothers had a higher incidence of gestational diabetes and pregnancy-induced hypertension compared to normal weight mothers (5.4% vs. 1.8%, and 7.2% vs. 0.6% respectively, P < 0.01), a higher rate of labor induction (20.4% vs. 10.2%, P < 0.01), and a higher cesarean section rate (19.6% vs. 10.8%, P < 0.05). There was also a significant difference in the prevalence of macrosomia in the offspring (16.8% vs. 8.4%, P < 0.05).

CONCLUSION

Obese pregnant women are at high risk for complications during delivery and therefore need careful pre-conception and prenatal counseling, as well as perinatal management.

Communities mobilizing for change on alcohol: outcomes from a randomized community trial

OBJECTIVE

Communities Mobilizing for Change on Alcohol (CMCA) was a randomized 15-community trial of a community organizing intervention designed to reduce the accessibility of alcoholic beverages to youths under the legal drinking age.

METHOD

Data were collected at baseline before random assignment of communities to intervention or control condition, and again at follow-up after a 2.5-year intervention. Data collection included in-school surveys of twelfth graders, telephone surveys of 18- to 20-year-olds and alcohol merchants, and direct testing of the propensity of alcohol outlets to sell to young buyers. Analyses were based on mixed-model regression, used the community as the unit of assignment, took into account the nesting of individual respondents or alcohol outlets within each community, and controlled for relevant covariates.

RESULTS

Results show that the CMCA intervention significantly and favorably affected both the behavior of 18- to 20-year-olds (effect size = 0.76, p<.01) and the practices of on-sale alcohol establishments (effect size = 1.18, p<.05), may have favorably affected the practices of off-sale alcohol establishments (effect size = 0.32, p = .08), but had little effect on younger adolescents. Alcohol merchants appear to have increased age-identification checking and reduced propensity to sell to minors. Eighteen- to 20-year-olds reduced their propensity to provide alcohol to other teens and were less likely to try to buy alcohol, drink in a bar or consume alcohol.

CONCLUSIONS

Community organizing is a useful intervention approach for mobilizing communities for institutional and policy change to improve the health of the population.

Relation between income inequality and mortality: empirical demonstration

OBJECTIVE

To assess the extent to which observed associations at population level between income inequality and mortality are statistical artefacts.

DESIGN

Indirect "what if" simulation by using observed risks of mortality at individual level as a function of income to construct hypothetical state level mortality specific for age and sex as if the statistical artefact argument were 100% correct.

SETTING

Data from the 1990 census for the 50 US states plus Washington, DC, were used for population distributions by age, sex, state, and income range; data disaggregated by age, sex, and state from the Centers for Disease Control and Prevention were used for mortality; and regressions from the national longitudinal mortality study were used for the individual level relation between income and risk of mortality.

RESULTS

Hypothetical mortality, while correlated with inequality (as implied by the logic of the statistical artefact argument), showed a weaker association with states' levels of income inequality than the observed mortality.

CONCLUSIONS

The observed associations in the United States at the state level between income inequality and mortality cannot be entirely or substantially explained as statistical artefacts of an underlying individual level relation between income and mortality. There remains an important association between income inequality and mortality at state level over and above anything that could be accounted for by any statistical artefact. This result reinforces the need to consider a broad range of factors, including the social milieu, as fundamental determinants of health.

Management of protein and energy intake in dialysis patients

Malnutrition is not uncommon in patients with end-stage renal disease treated with maintenance dialysis. The presence of several abnormal parameters of nutritional status are reported to be predictive of poorer outcomes in these patients, compared to dialysis patients without evidence of malnutrition. This article describes methods that may be used to recognize the presence of malnutrition in end-stage renal disease patients and the management of protein and energy intake. Whether the correction of malnutrition will improve outcomes, such as morbidity and mortality, is unknown.

Nutrition impact of peritoneal dialysis solutions

All peritoneal dialysis (PD) solutions are designed to remove toxins and water, normalize the blood electrolyte profile, and provide alkali to help maintain acid-base balance. Different formulations, however, may have different effects upon nutrition status. Solutions with 40, as opposed to 35, mEq/l of sodium lactate have been found to promote weight and muscle mass gain and reduce hospitalization in malnourished PD patients. Glucose is varied to produce solutions with different ultrafiltration potential. The glucose absorbed from the PD solution has a protein-sparing effect. The high glucose concentrations necessary for sustained ultrafiltration over a long dialysis dwell, however, often produce appetite suppression and metabolic abnormalities. Solutions formulated with glucose polymers, instead of hypertonic glucose, may provide sustained ultrafiltration over long dwells with lower carbohydrate absorption and perhaps fewer metabolic effects. Amino acids can also be substituted for glucose at relatively low concentrations. A number of studies have shown that amino acids absorbed from the dialysis solution can provide nutritional benefit to malnourished PD patients.

Effectiveness of nutrition interventions in the management of malnourished patients treated with maintenance dialysis

Malnutrition is not uncommon in patients with end-stage renal disease treated with maintenance dialysis. In addition, malnutrition is associated with increased morbidity and mortality in these patients. A number of interventions have been undertaken to increase nutrient intake or to provide growth factors to induce anabolism. These interventions have met with varying degrees of success. The most efficient and effective method of managing malnutrition in the dialysis patient is still unclear. More research is needed to determine the most appropriate method of management of malnutrition.

Assessing ecologic proxies for household income: a comparison of household and neighbourhood level income measures in the study of population health status

This paper examines the validity of using ecologic measures of socioeconomic status as proxies for individual-level measures in the study of population health. Based on a representative 5% sample of households in a Canadian province, the study integrated three sources of information: administrative records of individual health care utilization, records of deaths and 1986 census records which contained information on household income and average neighbourhood income. Thirteen measures of health status were developed from these sources of information. The hypothesis that risk estimates derived from ecologic income measures will be attenuated relative to estimates obtained from household income was not supported. These results provide evidence for the use of ecologic-level measures of income in studies which do not have access to individual-level income measures.

Adolescent alcohol use and the community health agenda: a study of leaders' perceptions in 28 small towns

The study assessed leaders' perceptions of adolescent alcohol use as a public health issue in 28 small communities in northern Minnesota, as part of formative evaluation for a community-based intervention to reduce adolescent alcohol access and consumption. One hundred and eighteen leaders from five key community sectors were interviewed about their perceptions of social, health and alcohol-related problems in their communities. Analyses indicated that school representatives and police chiefs perceived adolescent alcohol use and related problems to be serious; newspaper editors mentioned other social problems more often; and mayors and business representatives did not perceive adolescent alcohol problems to be as serious. In relation to efforts to affect local policy, the study suggested government and business sectors in these communities may need to be educated about the problem to build its importance on the community agenda of health issues. Thus community leaders in some sectors may comprise a key target audience for intervention.

Rapid syncytium formation between human T-cell leukaemia virus type-I (HTLV-I)-infected T-cells and human nervous system cells: a possible implication for tropical spastic paraparesis/HTLV-I associated myelopathy

Tropical spastic paraparesis/HTLV-I associated myelopathy (TSP/HAM), is characterized by infiltration of human T cell leukaemia virus type-I (HTLV-I)-infected T-cells, anti-HTLV-I cytotoxic T cells and macrophages into the patients' cerebrospinal fluid and by intrathecally formed anti-HTLV-I antibodies. This implies that the disease involves a breakdown of the blood-brain barrier. Since astrocytes play a central role in establishing this barrier, the authors investigated the hypothesis that the HTLV-I infected T cells disrupt this barrier by damaging the astrocytes. The present study revealed the HTLV-I-producing T cells conferred a severe cytopathic effect upon monolayers of astrocytoma cell line in co-cultures. Following co-cultivation, HTLV-I DNA and proteins appeared in the monolayer cells, but after reaching a peak their level gradually declined. This appearance of the viral components was proved to result from a fusion of the astrocytic cells with the virus-producing T cells, whereas their subsequent decline reflected the destruction of the resulting syncytia. This fusion could be specifically blocked by anti HTLV-I Env antibodies, indicating that it was mediated by the viral Env proteins expressed on the surface of the virus-producing cells. Similar fusion was observed between the HTLV-I-producing cells and certain other human nervous system cell lines. If such fusion of HTLV-I-infected T cells occurs also with astrocytes and other nervous system cells in TSP/HAM patients, it may account, at least partially, for the blood-brain barrier breakdown and some of the neural lesions in this syndrome.

Intraperitoneal nutrition

Provision of nutrients through the peritoneum is as old as peritoneal dialysis (PD) itself. Studies with a shelf-stable amino acid-based dialysis solution have shown that the amino acids absorbed during one exchange quantitatively exceed the daily losses of proteins and amino acids. The supplementary amino acids are well tolerated and can induce protein anabolism in many malnourished PD patients, as is evident from increased nitrogen balance, insulin-like growth factor-1, and increased concentrations of serum proteins. Such solutions offer a convenient means of providing nutritional supplementation to address the major nutritional needs of PD patients.

Perceived abuse and neglect as risk factors for suicidal behavior in adolescent inpatients

The aim of this study was to assess relative risk of histories of different types of abuse (sexual, physical, and emotional) and neglect (physical and emotional) for suicidal behavior (attempts, ideation, and self-mutilation) in psychiatrically hospitalized adolescents. Seventy-one adolescent inpatients (34 boys, 37 girls) completed self-report measures of abuse and neglect, current suicidal ideation, and lifetime suicide and self-mutilation attempts. The prevalence of sexual and physical abuse was 37.5% and 43.7%, respectively, with 31.3% and 61% of youngsters reporting emotional and physical neglect. Fifty-one percent of youngsters had made suicide attempts, and 39% had self-mutilated. Suicide attempters were significantly more likely to be female, Latino, to report sexual, physical, and emotional abuse, and to endorse emotional neglect. In multivariate analyses, female gender, sexual abuse, and emotional neglect remained significant predictors of self-mutilation and suicidal ideation. Female gender and sexual abuse remained significant predictors of suicide attempts. These findings suggest that emotional neglect is an important and deleterious component of maltreatment experiences and may be a more powerful predictor of suicidal behavior in hospitalized adolescents than physical abuse, emotional abuse, and physical neglect.

Effectiveness of nutrition interventions in the pre-ESRD and the ESRD population

Malnutrition is present in approximately 40% of patients treated with maintenance dialysis, and several serum proteins that are associated with malnutrition are also associated with decreased survival in this patient population. This article will review interventions to treat malnutrition in patients with chronic renal failure, as well as those treated with maintenance hemodialysis and peritoneal dialysis. Effectiveness of the interventions, as well as the design of trials to evaluate these interventions, are discussed.