Effect of Intrafix® SafeSet infusion apparatus on phlebitis in a neurological intensive care unit: a case-control study

OBJECTIVE

To investigate the effect of the Intrafix(®) SafeSet infusion apparatus on the incidence of phlebitis in patients being intravenously infused in a neurological intensive care unit (ICU).

METHODS

Patients aged > 12 years, with no history of diabetes mellitus and no existing phlebitis, requiring a daily peripheral intravenous infusion of ≥ 8 h with the total period lasting ≥ 3 days, were enrolled. Infusions were performed using the Intrafix(®) SafeSet or normal infusion apparatus. Incidence of phlebitis (scored according to the Infusion Nursing Standards of Practice of the American Infusion Nurses Society) was analysed.

RESULTS

Patients (n = 1545) were allocated to Intrafix(®) SafeSet (n = 709) or normal infusion (n = 836) groups, matched for age, gender and preliminary diagnosis. Incidence of phlebitis was significantly higher using normal infusion apparatus compared with the Intrafix(®) SafeSet (23.4% versus 17.9%, respectively).

CONCLUSION

Intrafix(®) SafeSet infusion apparatus significantly reduced the incidence of phlebitis in patients in the neurological ICU, compared with normal infusion apparatus, and may be suitable for use in routine clinical practice.

Detectability and reproducibility of plasma levels of chemokines and soluble receptors

BACKGROUND

Multiplex assays are available to measure an array of circulating chemokines, soluble cytokine receptors and growth factors. However, there is limited information regarding whether these analytes are suitable for large-scale epidemiological studies to assess their relationships with chronic diseases, including cancer.

METHODS

We examined detectability, assay repeatability, and 3-year within-subject reproducibility of plasma levels of 25 chemokines and 11 soluble receptors of cytokines and growth factors selected from the Human Millipore Panels. Plasma samples were obtained from 36 men (average age 62 years) and 17 women (average age 32 years) who participated in two epidemiological studies. Inter-assay and within-subject reproducibility were assessed by intraclass correlation coefficients (ICC).

RESULTS

All analytes, except lymphotactin (47% detectability), were detectable in >90% of plasma samples. Inter-assay reproducibility for all analytes in 36 men tested three times on separate days were good to excellent (ICCs: 0.71-1.00). Within-subject reproducibility in 17 women sampled three times in three years were excellent (ICC ≥ 0.75) for five chemokines (eotaxin, fractalkine, 6Ckine, eotaxin 3, and SDF-1α+β) and three soluble receptors (sIL-1R2, sIL-4R and sVEGFR2); ICCs were fair to good (0.4 ≤ ICC < 0.75) for 15 chemokines and eight soluble receptors. However, five chemokines (GRO, IP-10, MIP-1β, BCA-1, and MIP-3α) had ICC < 0.4, suggesting biological variability.

CONCLUSION

Multiplex assays for plasma levels of selected chemokines and soluble receptors showed good to excellent assay detectability and repeatability. Most analytes also had good 3-year within-subject reproducibility, indicating that a single measurement of these analytes may be used to assess biomarker-disease associations.

Autonomic nerve development contributes to prostate cancer progression

Nerves are a common feature of the microenvironment, but their role in tumor growth and progression remains unclear. We found that the formation of autonomic nerve fibers in the prostate gland regulates prostate cancer development and dissemination in mouse models. The early phases of tumor development were prevented by chemical or surgical sympathectomy and by genetic deletion of stromal β2- and β3-adrenergic receptors. Tumors were also infiltrated by parasympathetic cholinergic fibers that promoted cancer dissemination. Cholinergic-induced tumor invasion and metastasis were inhibited by pharmacological blockade or genetic disruption of the stromal type 1 muscarinic receptor, leading to improved survival of the mice. A retrospective blinded analysis of prostate adenocarcinoma specimens from 43 patients revealed that the densities of sympathetic and parasympathetic nerve fibers in tumor and surrounding normal tissue, respectively, were associated with poor clinical outcomes. These findings may lead to novel therapeutic approaches for prostate cancer.

Work Organization, Area Labor-market Characteristics, and Depression among U.S. Nursing Home Workers: A Cross-classified Multilevel Analysis

Associations between forms of work organization that follow globalization and depression were examined in U.S. nursing home assistants. A cross-sectional study of 539 nurse assistants in 49 nursing homes in three states in 2000 assessed nursing home ownership type, managerial style, wage policy, nurse assistants' emotional stresses, and area labor-market characteristics (county income inequality, median household income, and social capital) in relation to the prevalence of depression among the nurse assistants. A cross-classified multilevel analysis was used. For-profit ownership, emotional strain, managerial pressure, and lack of seniority pay increases were associated with depression. Labor-market characteristics were not associated with depression once work organization was taken into account. The deregulation of the nursing home industry that accompanies globalization is likely to adversely affect the mental health of nursing home assistants.

Testing the proportional hazards assumption in case-cohort analysis

Background

Case-cohort studies have become common in epidemiological studies of rare disease, with Cox regression models the principal method used in their analysis. However, no appropriate procedures to assess the assumption of proportional hazards of case-cohort Cox models have been proposed.

Methods

We extended the correlation test based on Schoenfeld residuals, an approach used to evaluate the proportionality of hazards in standard Cox models. Specifically, pseudolikelihood functions were used to define “case-cohort Schoenfeld residuals”, and then the correlation of these residuals with each of three functions of event time (i.e., the event time itself, rank order, Kaplan-Meier estimates) was determined. The performances of the proposed tests were examined using simulation studies. We then applied these methods to data from a previously published case-cohort investigation of the insulin/IGF-axis and colorectal cancer.

Results

Simulation studies showed that each of the three correlation tests accurately detected non-proportionality. Application of the proposed tests to the example case-cohort investigation dataset showed that the Cox proportional hazards assumption was not satisfied for certain exposure variables in that study, an issue we addressed through use of available, alternative analytical approaches.

Conclusions

The proposed correlation tests provide a simple and accurate approach for testing the proportional hazards assumption of Cox models in case-cohort analysis. Evaluation of the proportional hazards assumption is essential since its violation raises questions regarding the validity of Cox model results which, if unrecognized, could result in the publication of erroneous scientific findings.

Treatment-related changes in serum lipids and inflammation: clinical relevance remains unclear. Analyses from the Women's Interagency HIV study

Among 127 HIV-infected women, the magnitude of high-density lipoprotein cholesterol (HDLc) increases after HAART initiation predicted the magnitude of concurrent decreases in inflammation biomarkers. After HAART initiation, changes in low-density lipoprotein cholesterol (LDLc) and inflammation were unrelated. In the same population, predicted risk of coronary heart disease, based upon levels of standard clinical risk factors, was similar before and after HAART. Thus, it remains unknown whether short-term treatment-related changes in standard risk factors may appreciably change risk of cardiovascular disease (CVD).

A pooled analysis of 1,546 patients with AIDS-related lymphoma (ARL): An assessment of prognostic factors by treatment era

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Background: Management of ARL evolved in the last 2 decades. We previously reported prognostic factors in a pooled analysis of 1,546 patients with ARL, and here present analysis of these factors over time to determine if their prognostic significance has changed. Methods: Following a systematic review, we assembled individual patient data from 19 prospective phase 2/3 clinical trials (published 1993-2010) for ARL (n=1,546). Factors analyzed include age, sex, histology, CD4 count, prior history of (h/o) AIDS, & age-adjusted (aa) IPI. The endpoint was overall survival (OS) expressed as the hazard ratio (HR) for death. We used separate Cox proportional hazard models adjusted for the other covariates to determine the significance of each variable in the following time periods: pre-cART [combination antiretroviral therapy] (<1996; n=388), early cART (‘96-‘00; n=694), modern cART (‘01-‘04; n=282) & current era (‘05-‘10; n=182). We also combined all enrollments in one Cox model to test for difference in association with OS over enrollment periods. Results: Rituximab use was limited in the early cART (20%) compared with the modern cART (83%) and current (93%) eras. Histology & sex were not significantly associated with OS in any time period. Increasing age was associated with worse OS in the pre-cART (HR 1.02; p<0.01) and current (HR 1.05, p=0.04) eras. A prior h/o AIDS increased risk of death during early cART (HR 1.31, p=0.047) but was not significant after 2000. Meanwhile, baseline CD4 count <50 was a poor prognostic factor during early (HR 1.78, p<0.01) and modern cART (HR 2.76, p=0.001) eras, but not in the current era. The aaIPI predicted worse OS in each time period (pre-cART: HR 1.54, p<0.0001; early cART: HR 1.49, p<0.0001; modern cART: HR 1.52, p<0.01; current era: HR 2.34, p<0.0001). No significant interaction between each prognostic factor with enrollment was found. Conclusions: In this pooled analysis of 1,546 patients with ARL, aaIPI was the only consistently significant prognostic factor and its effect was magnified in the current era. HIV-related factors gained prognostic relevance in the early and modern cART era but may not be as relevant with current treatment strategies.

Emergency Physician Patterns Related to Anticoagulation of Patients with Recent-Onset Atrial Fibrillation and Flutter

Guidelines strongly recommend long-term anticoagulation with warfarin for patients with newly recognized AF who have high embolic risk by virtue of a CHADS₂ (Congestive Heart Failure, Hypertension, Age >65, Diabetes, History of Stroke) score ≥ 2. The goal of this study was to determine patterns of emergency department-initiated anticoagulation among eligible patients discharged from Canadian centers with an episode of recent-onset atrial fibrillation and flutter (RAFF) and determine if decision-making is driven by the CHADS₂ score or other factors. This was accomplished by examining health records using uniform case identification and data abstraction as well as centralized quality control; it was conducted in 8 Canadian university emergency departments over a 12-month period. Eligible patients for this analysis demonstrated RAFF requiring emergency management, were not already taking warfarin and were not admitted to hospital. Univariate analyses were conducted using T-test or Chi-square to select factors associated with anticoagulation initiation at a significance level of p < 0.15 and multiple logistic regression was employed to evaluate independent predictors after adjustment for confounders. Among 633 eligible patients, only 21 out of 120 patients (18%) with a CHADS₂ score ≥ 2 received anticoagulation and among 70 patients who were given anticoagulation only 21 (30%) had a CHADS₂ score ≥ 2. Independent predictors of anticoagulation included age by 10-year strata: (OR = 1.7; 95% CI 1.3 - 2.1), heparin use in the anticoagulation (OR = 9.6; 95% CI 4.9 - 18.9), a new prescription for metoprolol (OR = 9.6; 95% CI 4.9 - 18.9) and being referred to cardiology for follow-up (OR = 5.6; 95% CI 2.6 - 12.0). CHADS₂ ≥ 2 doubled the likelihood of being prescribed anticoagulation (OR= 2.0; 95% CI 1.5 - 3.5) but was not an independent predictor. It was thus determined that patients discharged from the emergency department in this study were not prescribed anticoagulation in keeping with current recommendations. This practice gap merits further investigation and may benefit from educational efforts or enhanced support for anticoagulation use from the emergency department.

Sample size requirements to detect an intervention by time interaction in longitudinal cluster randomized clinical trials with random slopes

In longitudinal cluster randomized clinical trials (cluster-RCT), subjects are nested within a higher level unit such as clinics and are evaluated for outcome repeatedly over the study period. This study design results in a three level hierarchical data structure. When the primary goal is to test the hypothesis that an intervention has an effect on the rate of change in the outcome over time and the between-subject variation in slopes is substantial, the subject-specific slopes are often modeled as random coefficients in a mixed-effects linear model. In this paper, we propose approaches for determining the samples size for each level of a 3-level hierarchical trial design based on ordinary least squares (OLS) estimates for detecting a difference in mean slopes between two intervention groups when the slopes are modeled as random. Notably, the sample size is not a function of the variances of either the second or the third level random intercepts and depends on the number of second and third level data units only through their product. Simulation results indicate that the OLS-based power and sample sizes are virtually identical to the empirical maximum likelihood based estimates even with varying cluster sizes. Sample sizes for random versus fixed slope models are also compared. The effects of the variance of the random slope on the sample size determinations are shown to be enormous. Therefore, when between-subject variations in outcome trends are anticipated to be significant, sample size determinations based on a fixed slope model can result in a seriously underpowered study.

Activation of mGluR4 promotes proliferation of rat neural progenitor cells while mediating activation of ERK1/2 signaling pathway

Metabotropic glutamate receptors (mGluRs) influence the proliferation and differentiation of neural progenitor cells (NPCs) in the brain. They may play a major role in neurogenesis during embryonic development and in the adult brain. In this study, we investigated the expression of mGluR4 in NPCs and its possible role in the proliferation of rat embryonic NPCs in vitro, the expression of cyclin D1 and the activation of signaling pathways of mitogen&mdash;activated protein kinases (MAPKs). The results showed that mGluR4 protein was expressed in NPCs in vitro. mGluR4 selective agonist VU0155041 promoted the proliferation of NPCs by increasing cell activity, diameter of neurospheres and cell division. In addition, mGluR4 siRNA decreased the proliferation of NPCs. The protein expression of cyclin D1 increased with VU0155041 treatment and decreased after siRNA treatment. We also demonstrated that activation of ERK1/2 signaling pathways was involved in the proliferation of NPCs. VU0155041 increased phosphorylation of p&mdash;ERK1/2 levels, and mGluR4 siRNA decreased p&mdash;ERK1/2 levels. Furthermore, p&mdash;p38 expression was decreased by VU0155041 but was increased by mGluR4 siRNA. ERK1/2 inhibitor U0126 attenuated the increase of proliferation and cyclin D1 induced by VU0155041. These findings indicate that mGluR4 promotes the proliferation of rat NPCs and cyclin D1 expression through activation of ERK1/2 signaling pathways in vitro, suggesting that mGluR4 may play an important role in brain development. This study will help to develop a new potential therapeutic agent for brain injury and for the prevention of neurodegenerative disorders.

A comparison of the polytomous logistic regression and joint cox proportional hazards models for evaluating multiple disease subtypes in prospective cohort studies

BACKGROUND

Polytomous logistic regression models are commonly used in case-control studies of cancer to directly compare the risks associated with an exposure variable across multiple cancer subtypes. However, the validity, accuracy, and efficiency of this approach for prospective cohort studies have not been formally evaluated.

METHODS

We investigated the performance of the polytomous logistic regression model and compared it with an alternative approach based on a joint Cox proportional hazards model using simulation studies. We then applied both methods to a prospective cohort study to assess whether the association of breast cancer with body size differs according to estrogen and progesterone receptor-defined subtypes.

RESULTS

Our simulations showed that the polytomous logistic regression model but not the joint Cox regression model yielded biased results in comparing exposure and disease subtype associations when the baseline hazards for different disease subtypes are nonproportional. For this reason, an analysis of a real data set was based on the joint Cox proportional hazards model and showed that body size has a significantly greater association with estrogen- and progesterone-positive breast cancer than with other subtypes.

CONCLUSIONS

Because of the limitations of the polytomous logistic regression model for the comparison of exposure-disease associations across disease subtypes, the joint Cox proportional hazards model is recommended over the polytomous logistic regression model in prospective cohort studies.

IMPACT

The article will promote the use of the joint Cox model in a prospective cohort study. Examples of SAS and S-plus programming codes are provided to facilitate use by nonstatisticians.

Power and sample size calculations for evaluating mediation effects in longitudinal studies

Current methods of power and sample size calculations for the design of longitudinal studies to evaluate mediation effects are mostly based on simulation studies and do not provide closed-form formulae. A further challenge due to the longitudinal study design is the consideration of missing data, which almost always occur in longitudinal studies due to staggered entry or drop out. In this article, we consider the product of coefficients as a measure for the longitudinal mediation effect and evaluate three methods for testing the hypothesis on the longitudinal mediation effect: the joint significant test, the normal approximation and the test of b methods. Formulae for power and sample size calculations are provided under each method while taking into account missing data. Performance of the three methods under limited sample size are examined using simulation studies. An example from the Einstein aging study is provided to illustrate the methods.

Improvement in stroke risk prediction: role of C-reactive protein and lipoprotein-associated phospholipase A2 in the women's health initiative

BACKGROUND

Classification of risk of ischemic stroke is important for medical care and public health reasons. Whether addition of biomarkers adds to predictive power of the Framingham Stroke Risk or other traditional risk factors has not been studied in older women.

METHODS

The Hormones and Biomarkers Predicting Stroke Study is a case-control study of blood biomarkers assayed in 972 ischemic stroke cases and 972 controls, nested in the Women's Health Initiative Observational Study of 93, 676 postmenopausal women followed for an average of eight-years. We evaluated additive predictive value of two commercially available biomarkers: C-reactive protein and lipoprotein-associated phospholipase A2 to determine if they added to risk prediction by the Framingham Stroke Risk Score or by traditional risk factors, which included lipids and other variables not included in the Framingham Stroke Risk Score. As measures of additive predictive value, we used the C-statistic, net reclassification improvement, category-less net reclassification improvement, and integrated discrimination improvement index.

RESULTS

Addition of C-reactive protein to Framingham risk models or additional traditional risk factors overall modestly improved prediction of ischemic stroke and resulted in overall net reclassification improvement of 6·3%, (case net reclassification improvement=3·9%, control net reclassification improvement=2·4%). In particular, high-sensitivity C-reactive protein was useful in prediction of cardioembolic strokes (net reclassification improvement=12·0%; 95% confidence interval 4·3-19·6%) and in strokes occurring in less than three-years (net reclassification improvement=7·9%, 95% confidence interval 0·8-14·9%). Lipoprotein-associated phospholipase A2 was useful in risk prediction of large artery strokes (net reclassification improvement=19·8%, 95% confidence interval 7·4-32·1%) and in early strokes (net reclassification improvement=5·8%, 95% confidence interval 0·4-11·2%).

CONCLUSIONS

C-reactive protein and lipoprotein-associated phospholipase A2 can improve prediction of certain subtypes of ischemic stroke in older women, over the Framingham stroke risk model and traditional risk factors, and may help to guide surveillance and treatment of women at risk.

Association of subclinical atherosclerosis with lipid levels amongst antiretroviral-treated and untreated HIV-infected women in the Women's Interagency HIV study

OBJECTIVE

We examined serum lipids in association with carotid artery intima-media thickness (CIMT) in HIV-infected and HIV-uninfected women.

METHODS

In 2003-4, among 1827 Women's Interagency HIV Study participants, we measured CIMT and lipids (high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), total cholesterol (TC), non-HDL-c). A subset of 520 treated HIV-infected women had pre-1997 lipid measures. We used multivariable linear regression to examine associations between lipids and CIMT.

RESULTS

In HIV-uninfected women, higher TC, LDL-c and non-HDL-c were associated with increased CIMT. Among HIV-infected women, associations of lipids with CIMT were observed in treated but not untreated women. Among the HIV-infected women treated in 2003-4, CIMT was associated both with lipids measured a decade earlier in infection, and with late lipid measurements.

CONCLUSION

Among HIV-infected women, hyperlipidemia is most strongly associated with subclinical atherosclerosis in treated women. Among treated women, the association appeared strongest early in the disease course.

c-Met: A potential therapeutic target for hepatocellular carcinoma

The approval of receptor tyrosine kinase (RTK) targeted agent sorafenib as the first effective drug for the systemic treatment of advanced hepatocellular carcinoma (HCC) represents a milestone in the treatment of this disease. A better understanding of HCC pathogenesis will lead to development of novel targeted treatments. As a typical member of the RTK family, c-Met represents an intriguing target for cancer therapy. The c-Met signaling pathway has been shown to be deregulated and to correlate with poor prognosis in a number of major human cancers. This review discusses the possibility of c-Met as a target in HCC treatment from the following respects: i) c-Met expression and activation profile in HCC, ii) relationship between c-Met and clinicopathologic state and prognosis of HCC, iii) role of c-Met signaling activity in HCC genesis and progression, and iv) strategy of c-Met pathway targeting therapy in HCC treatment.

CMR imaging assessing viability in patients with chronic ventricular dysfunction due to coronary artery disease: a meta-analysis of prospective trials

OBJECTIVES

The purpose of this study was to compare the diagnostic accuracy of cardiac magnetic resonance (CMR) assessing myocardial viability in patients with chronic left ventricular (LV) dysfunction due to coronary artery disease using 3 techniques: 1) end-diastolic wall thickness (EDWT); 2) low-dose dobutamine (LDD); and 3) contrast delayed enhancement (DE).

BACKGROUND

CMR has been proposed to assess myocardial viability over the past decade. However, the best CMR strategy to evaluate patients being contemplated for revascularization has not yet been determined. Some centers advocate DE CMR due to its high sensitivity to identify scar, whereas others favor the use of LDD CMR for its ability to identify contractile reserve.

METHODS

A systematic review of MEDLINE, Cochrane, and Embase for all the prospective trials assessing myocardial viability in subjects with chronic LV dysfunction using CMR was performed using a standard approach for meta-analysis for diagnostic tests and a bivariate analysis of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

A total of 24 studies of CMR evaluating myocardial viability with 698 patients fulfilled the inclusion criteria. Eleven studies used DE, 9 studies used LDD, and 4 studies used EDWT. Our meta-analysis indicates that among CMR methods, DE CMR provides the highest sensitivity as well as the highest NPV (95% and 90%, respectively) for predicting improved segmental LV contractile function after revascularization, followed by EDWT CMR, whereas LDD CMR demonstrated the lowest sensitivity/NPV among all modalities. On the other hand, LDD CMR offered the highest specificity and PPV (91% and 93%, respectively), followed by DE CMR, whereas EDWT showed the lowest of these parameters.

CONCLUSIONS

DE CMR provides the highest sensitivity and NPV, whereas LDD CMR provides the best specificity and PPV. In light of these findings, integrating these 2 methods should provide increased accuracy in evaluating patients with chronic LV dysfunction being considered for revascularization.

Quantitative assessment of invasive mena isoforms (Menacalc) as an independent prognostic marker in breast cancer

INTRODUCTION

Mena, an Ena/VASP protein family member, is a key actin regulatory protein. Mena is up-regulated in breast cancers and promotes invasion and motility of tumor cells. Mena has multiple splice variants, including Mena invasive (MenaINV) and Mena11a, which are expressed in invasive or non-invasive tumor cells, respectively. We developed a multiplex quantitative immunofluorescence (MQIF) approach to assess the fraction of Mena lacking 11a sequence as a method to infer the presence of invasive tumor cells represented as total Mena minus Mena11a (called Menacalc) and determined its association with metastasis in breast cancer.

METHODS

The MQIF method was applied to two independent primary breast cancer cohorts (Cohort 1 with 501 and Cohort 2 with 296 patients) using antibodies against Mena and its isoform, Mena11a. Menacalc was determined for each patient and assessed for association with risk of disease-specific death.

RESULTS

Total Mena or Mena11a isoform expression failed to show any statistically significant association with outcome in either cohort. However, assessment of Menacalc showed that relatively high levels of this biomarker is associated with poor outcome in two independent breast cancer cohorts (log rank P = 0.0004 for Cohort 1 and 0.0321 for Cohort 2). Multivariate analysis on combined cohorts revealed that high Menacalc is associated with poor outcome, independent of age, node status, receptor status and tumor size.

CONCLUSIONS

High Menacalc levels identify a subgroup of breast cancer patients with poor disease-specific survival, suggesting that Menacalc may serve as a biomarker for metastasis.

Risk of cervical precancer and cancer among HIV-infected women with normal cervical cytology and no evidence of oncogenic HPV infection

CONTEXT

US cervical cancer screening guidelines for human immunodeficiency virus (HIV)-uninfected women 30 years or older have recently been revised, increasing the suggested interval between Papanicolaou (Pap) tests from 3 years to 5 years among those with normal cervical cytology (Pap test) results who test negative for oncogenic human papillomavirus (HPV). Whether a 3-year or 5-year screening interval could be used in HIV-infected women who are cytologically normal and oncogenic HPV-negative is unknown.

OBJECTIVE

To determine the risk of cervical precancer or cancer defined cytologically (high-grade squamous intraepithelial lesions or greater [HSIL+]) or histologically (cervical intraepithelial neoplasia 2 or greater [CIN-2+]), as 2 separate end points, in HIV-infected women and HIV-uninfected women who at baseline had a normal Pap test result and were negative for oncogenic HPV.

DESIGN, SETTING, AND PARTICIPANTS

Participants included 420 HIV-infected women and 279 HIV-uninfected women with normal cervical cytology at their enrollment in a multi-institutional US cohort of the Women's Interagency HIV Study, between October 1, 2001, and September 30, 2002, with follow-up through April 30, 2011. Semiannual visits at 6 clinical sites included Pap testing and, if indicated, cervical biopsy. Cervicovaginal lavage specimens from enrollment were tested for HPV DNA using polymerase chain reaction. The primary analysis was truncated at 5 years of follow-up.

MAIN OUTCOME MEASURE

Five-year cumulative incidence of cervical precancer and cancer.

RESULTS

No oncogenic HPV was detected in 369 (88% [95% CI, 84%-91%]) HIV-infected women and 255 (91% [95% CI, 88%-94%]) HIV-uninfected women with normal cervical cytology at enrollment. Among these oncogenic HPV-negative women, 2 cases of HSIL+ were observed; an HIV-uninfected woman and an HIV-infected woman with a CD4 cell count of 500 cells/μL or greater. Histologic data were obtained from 4 of the 6 clinical sites. There were 6 cases of CIN-2+ in 145 HIV-uninfected women (cumulative incidence, 5% [95% CI, 1%-8%]) and 9 cases in 219 HIV-infected women (cumulative incidence, 5% [95% CI, 2%-8%]). This included 1 case of CIN-2+ in 44 oncogenic HPV-negative HIV-infected women with CD4 cell count less than 350 cells/μL (cumulative incidence, 2% [95% CI, 0%-7%]), 1 case in 47 women with CD4 cell count of 350 to 499 cells/μL (cumulative incidence, 2% [95% CI, 0%-7%]), and 7 cases in 128 women with CD4 cell count of 500 cells/μL or greater (cumulative incidence, 6% [95% CI, 2%-10%]). One HIV-infected and 1 HIV-uninfected woman had CIN-3, but none had cancer.

CONCLUSION

The 5-year cumulative incidence of HSIL+ and CIN-2+ was similar in HIV-infected women and HIV-uninfected women who were cytologically normal and oncogenic HPV-negative at enrollment.

Estimation and inference on correlations between biomarkers with repeated measures and left-censoring due to minimum detection levels

Statistical approaches for estimating and drawing inference on the correlation between two biomarkers that are repeatedly assessed over time and subject to left-censoring because minimum detection levels are lacking. We propose a linear mixed-effects model and estimate the parameters with the Monte Carlo expectation maximization (MCEM) method. Inferences regarding the model parameters and the correlation between the biomarkers are performed by applying Louis's method and the delta method. Simulation studies were conducted to compare the proposed MCEM method with existing methods including the maximum likelihood estimation method, the multiple imputation method, and two widely used ad hoc approaches: replacing the censored values with the detection limit or with half of the detection limit. The results show that the performance of the MCEM with respect to relative bias and coverage probability for the 95% confidence interval is superior to the detection limit and half of the detection limit approaches and exceeds that of the multiple imputation method at medium to high levels of censoring, and the standard error estimates from the MCEM method are close to ideal. The maximum likelihood estimation method can estimate the parameters accurately; however, a nonpositive definite information matrix can occur so that the variances are not estimable. These five methods are illustrated with data from a longitudinal human immunodeficiency virus study to estimate and draw inference on the correlation between human immunodeficiency virus RNA levels measured in plasma and in cervical secretions at multiple time points.

Vasohibin 2 is transcriptionally activated and promotes angiogenesis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) typically relies on angiogenesis for its malignant behavior, including growth and metastasis. Vasohibin 2 (VASH2) was previously identified as an angiogenic factor, but its role in tumorigenesis is unknown. Using quantitative PCR and western blot analyses, we found that VASH2 is overexpressed in HCC cells and tissues. Using chromatin immunoprecipitation, we detected histone modifications at the putative VASH2 promoter, with increased H3K4 trimethylation and H3 acetylation and decreased H3K27 trimethylation, suggesting that epigenetic mechanisms are responsible for the deregulated VASH2 transcription in HCC. Knockdown of VASH2 via siRNA inhibited the proliferation of the hepatoma cell lines by delaying cell cycle progression and increasing apoptosis. Importantly, we found VASH2 secreted in the culture supernatant, and co-expression of its secretory chaperone small vasohibin-binding protein (SVBP) further enhanced VASH2 secretion. The supernatant from HepG2 cells expressing VASH2 enhanced the proliferation, migration and tube formation of human umbilical vein endothelial cells, and knockdown of VASH2 significantly inhibited these effects. In an in vivo study using a nude mouse model, we found that exogenous VASH2 significantly contributed to tumor growth, microvessel density and hemoglobin concentration in the tumors. Further analyses showed that the VASH2-mediated increase in the transcription of fibroblast growth factor-2, vascular endothelial growth factor and vasohibin 1 may be the mechanism underlying these effects. Taken together, these data indicate that VASH2 is abnormally expressed in HCC cells as a result of histone modifications and that VASH2 contributes to the angiogenesis in HCC via an SVBP-mediated paracrine mechanism. These results indicate a novel and important role for VASH2 in HCC angiogenesis and malignant transformation.

A pooled analysis of 1,144 patients with HIV-associated lymphoma: Assessment of lymphoma-, HIV-, and treatment-specific factors on clinical outcomes

8005

Background: Non-Hodgkin Lymphoma (NHL) remains the most common malignancy in patients with HIV. Outcomes have significantly improved over the last decade, but there is no accepted consensus regarding the optimal initial therapeutic approach. Our objective was to assess the effects of clinical factors on response and survival. Methods: We performed a systematic review to search for prospective clinical phase II or III trials that assessed therapeutic interventions for HIV-associated NHL and assembled individual patient data from 16 trials published between 2000 and 2011 including 1144 patients (median N=62/trial, range 17-195). Treatment factors included type of chemotherapy (CHOP, N=642; EPOCH, N=178; CDE, N=191; intensive regimens, N=155) and rituximab use (N=542). Endpoints included complete response (CR), progression-free survival (PFS), and overall survival (OS). We used logistic regression and Cox proportional hazard models adjusted for age, sex, age-adjusted International Prognostic Index (IPI), baseline CD4 count, baseline HIV viral load, use of concurrent antiretroviral therapy, and histology. Odds ratios (OR) > 1 for CR denote improved CR, and hazard ratios (HR) < 1 indicate reduced risk of progression or death. Results: Among the lymphoma- and HIV-specific covariates evaluated, only a higher IPI score was associated with inferior CR rate, PFS and OS (p<0.001). Rituximab was associated with a higher CR rate (OR 1.75; p=0.017), better PFS (HR 0.39, p<0.001) and OS (HR 0.39, p<0.001); patients with a higher baseline CD4 count benefited more from rituximab (HR for OS 0.57 if baseline CD4 count ≥100/ul vs. <100/ul; p<0.001). For all histologies, initial therapy with the EPOCH regimen resulted in a better CR rate (OR 1.78, p=0.039), PFS (HR 0.61, p=0.032) and OS (HR 0.47, p<0.001) when compared to CHOP. Conclusions: In this pooled analysis including 1144 patients with HIV-associated NHL, the addition of rituximab to chemotherapy was associated with significantly improved CR rate, PFS, and OS, specifically for patients with a baseline CD4 count ≥100/uL. Treatment with infusional EPOCH was also more effective than CHOP.

Adipokines linking obesity with colorectal cancer risk in postmenopausal women

Mechanistic associations between obesity and colorectal cancer remain unclear. In this study, we investigated whether adipokines are risk factors for colorectal cancer and whether they may mediate its association with obesity. In a case-cohort study nested within the Women's Health Initiative cohort of postmenopausal women, baseline plasma samples from 457 colorectal cancer cases and 841 subcohort subjects were assayed for seven adipokines-adiponectin, leptin, plasminogen activator inhibitor-1 (PAI-1), resistin, hepatocyte growth factor, interleukin-6 (IL-6), and TNF-α. Serum insulin and estradiol values measured previously were also available for data analysis. After adjusting for age, race, smoking, colonoscopy history, and estrogen level, a low level of anti-inflammatory adiponectin and high levels of proinflammatory leptin, PAI-1, and IL-6 were associated with increased colorectal cancer risk, though only leptin remained significant after further adjustment for insulin [HRs comparing extreme quartiles (HR(Q4-Q1)), 1.84; 95% CI, 1.17-2.90]. Mediation analyses showed that leptin and insulin partially explained the association between waist circumference and colorectal cancer and attenuated it by 25% and 37%, respectively, with insulin being a significant mediator (P = 0.041). Our findings support the conclusion that adipokines involved in inflammation are associated with colorectal cancer risk, but that their effects may be mediated mostly by insulin, with leptin exerting an independent effect. Hyperinsulinemia and hyperleptinemia may therefore partially explain the adiposity association with colorectal cancer in postmenopausal women.

Abstract 4487: Inverse associations between soluble cytokine receptors and colorectal cancer risk

Laboratory studies have suggested that soluble receptors of proinflammatory cytokines could be anti-inflammatory by acting as decoy receptors, blocking binding of the cytokines to their membrane receptors, and hence inhibiting cytokine signaling. Thus, relatively high levels of soluble cytokine receptors and receptor antagonists may be protective factors against colorectal cancer, which is an inflammation-associated disease. This case-cohort study nested within the Women's Health Initiative Observational Study of postmenopausal women 50-79 years of age at baseline (1993-1998) examined whether baseline plasma levels of IL-1 receptor antagonist (IL-1Ra) and the soluble receptors of IL-6 (sIL-6R and sgp130), TNF (sTNF-R1 and sTNF-R2), and IL-1 (sIL-1R2) were inversely associated with colorectal cancer risk. Analytes were measured in 433 incident colorectal cancer cases and 823 subcohort members using multiplex assays (Millipore, Billerica, MA). Circulating levels of IL-6, TNF-α, insulin, and estradiol measured previously were also available for data analyses. IL-1Ra and the 5 soluble receptors did not correlate with each other or with their ligands (all correlations r &lt; 0.3), with the exception of sTNFR2, which was moderately correlated with sTNFR1 (r=0.51) and TNF-α (r=0.43). The table below shows the hazard ratios for colorectal cancer risk, when each analyte was entered separately into a Cox regression model adjusting for other colorectal cancer risk factors. Colorectal cancer risk decreased significantly with increasing levels of sIL-6R and sIL-1R2. The ratios of IL-6 or TNF-α to their soluble receptors were not associated with colorectal cancer risk. There were also no significant interactions between pairs of soluble receptors or between soluble receptors and their ligands. Increased circulating levels of sIL-6R and sIL-1R2 may confer protection against colorectal cancer. If our results are confirmed, these soluble receptors can be considered for chemoprevention.

Cytomegalovirus immunoglobulin G antibody is associated with subclinical carotid artery disease among HIV-infected women

BACKGROUND

Cytomegalovirus (CMV) infection has been implicated in immune activation and accelerated progression of immunodeficiency from human immunodeficiency virus (HIV) coinfection. We hypothesized that CMV is associated with vascular disease in HIV-infected adults.

METHODS

In the Women's Interagency HIV Study, we studied 601 HIV-infected and 90 HIV-uninfected participants. We assessed the association of CMV immunoglobulin G (IgG) level with carotid artery intima-media thickness, carotid artery distensibility, Young's elastic modulus, and blood pressures. Multivariable models adjusted for age, race/ethnicity, smoking, diabetes, and body mass index.

RESULTS

Mean CMV IgG levels were higher in HIV-infected women compared with HIV-uninfected women (P < .01). Among HIV-infected women, higher CMV IgG level was associated with decreased carotid artery distensibility (P < .01) and increased Young's modulus (P = .02). Higher CMV IgG antibody level was associated with increased prevalence of carotid artery lesions among HIV-infected women who achieved HIV suppression on antiretroviral therapy, but not among viremic or untreated HIV-infected women. Adjustment for Epstein-Barr virus antibody levels and C-reactive protein levels had no effect on the associations between CMV IgG levels and vascular parameters.

CONCLUSIONS

Cytomegalovirus antibody titers are increased in HIV-infected women and associated with subclinical cardiovascular disease. Host responses to CMV may be abnormal in HIV infection and associated with clinical disease.

Effect of long term low-fat dietary intervention on change in hemostatic factors: results from the Women's Health Initiative

Low-fat diet may play a role in prevention of cardiovascular disease (CVD) by altering the levels of hemostatic factors. There are yet limited data on the effects of low-fat diet on the circulating levels of these factors and existing studies are limited by small sample size and short duration of follow-up. We conducted an analysis in a subset of women (active arm = 723; control arm = 1036) within the Women's Health Initiative Dietary Modification Trial to investigate the long term effect of a low-fat diet on circulating levels of fibrinogen, factor VII concentration and factor VII activity among postmenopausal women aged 50-79 years. Using linear mixed effects model with random intercept and data from three follow-up visits (years 1, 3 and 6) we evaluated the change in each factor over time. Overall, the changes in these factors were small (less than 5%) in both the arms of the trials at the end of intervention and there was no significant difference in mean change between the two arms. Our results indicate that the low-fat dietary intervention was not associated with significant changes in hemostatic factors among postmenopausal women.

Meta-analysis: the diagnostic accuracy of lactose breath hydrogen or lactose tolerance tests for predicting the North European lactase polymorphism C/T-13910

BACKGROUND

  The diagnostic accuracy of two indirect tests of lactose digestion, lactose breath hydrogen and lactose tolerance tests, have not been systematically reviewed for comparison with available publications on genotype.

AIM

  To perform a meta-analysis of available studies that compares the north-European genetic polymorphism C/T-13910 with the lactose breath hydrogen and the lactose tolerance tests, to determine their ability to predict geno/phenotype relationships. We examine the effects of lactose loading dose, inclusion of children and latitudes of study centre on comparative outcome.

METHODS

  An electronic database of the literature as well as individual references in articles were searched with the theme of genetics of lactase and comparisons with breath or lactose tolerance tests were carried out. Random effect and fixed effect models were used for breath and lactose tolerance tests respectively, to report summary accuracy measures with 95% confidence intervals (CI).

RESULTS

  The search revealed 19 studies: 17 evaluated breath hydrogen, five lactose tolerance test (3/17 overlapped). Overall sensitivity was 0.88 (CI, 0.85-0.90), specificity was 0.85 (CI, 0.82-0.87) for breath test. Heterogeneity was explored by adjusting for studies including children, high or low dose lactose and to some extent by site of study. The lactose tolerance test showed sensitivity of 0.94 (0.9-0.97) and specificity of 0.90 (0.84-0.95) with a nonsignificant heterogeneity.

CONCLUSION

  The diagnostic accuracy of both tests individually reflects expected geno/phenotypes when the populations are well defined.

Cervicovaginal human papillomavirus (HPV)-infection before and after hysterectomy: evidence of different tissue tropism for oncogenic and nononcogenic HPV types in a cohort of HIV-positive and HIV-negative women

Human papillomavirus (HPV) is detected in nearly all cervical cancers and approximately half of vaginal cancers. However, vaginal cancer is an order of magnitude less common than cervical cancer, not only in the general population but also among women with HIV/AIDS. It is interesting therefore that recent studies found that HPV was common in both normal vaginal and cervical tissue, with higher prevalence of nononcogenic HPV types in the vagina. In our investigation, we prospectively examined HPV infection in 86 HIV-positive and 17 HIV-negative women who underwent hysterectomy during follow-up in a longitudinal cohort. Cervicovaginal lavage specimens were obtained semi-annually and tested for HPV DNA by polymerase chain reaction. To address possible selection biases associated with having a hysterectomy, subjects acted as their own comparison group--before versus after hysterectomy. The average HPV prevalence was higher in HIV-positive than HIV-negative women both before (59% vs. 12%; p < 0.001) and after hysterectomy (56% vs. 6%; p < 0.001). Multivariate random effects models (within-individual comparisons) demonstrated significantly lower HPV prevalence [odds ratio (OR) = 0.71; 95% confidence interval (CI) = 0.59-0.85) after hysterectomy. The association of HPV prevalence with hysterectomy was similar among HIV-positive and HIV-negative women. However, hysterectomy had greater effects on oncogenic (OR = 0.48; 95% CI = 0.35-0.66) than nononcogenic HPV types (OR = 0.89; 95% CI = 0.71-1.11; P(interaction) = 0.002). Overall, we observed greater reductions in oncogenic than nononcogenic HPV prevalence after hysterectomy. If correct, these data could suggest that oncogenic HPV have greater tropism for cervical compared to vaginal epithelium, consistent with the lower incidence of vaginal than cervical cancer.

A prospective investigation of coffee drinking and endometrial cancer incidence

Coffee drinking may be associated with reduced risk of endometrial cancer; however, prospective data are limited. Further, it is not clear whether any association between coffee and endometrial cancer differs according to coffee caffeine content. The association of coffee drinking with incidence of endometrial cancer was evaluated among 226,732 women, aged 50-71, enrolled in the NIH-AARP Diet and Health Study who completed a baseline epidemiologic questionnaire. Following a mean 9.3 years of follow-up, data were available for 1,486 incident endometrial cancer cases. Cox proportional hazards models were used to estimate associations of coffee with endometrial cancer incidence. Sub-group analyses were performed according to smoking status, hormone therapy use (HT) and body habitus. Coffee drinking was inversely related to incidence of endometrial cancer (hazard ratio [HR] comparing drinking of >3 cups/day versus no cups = 0.64, 95% CI, 0.51-0.80; P(trend) = 0.0004). The association of coffee with endometrial cancer risk was apparent for consumption of both regular (HR per cup = 0.90, 95% CI, 0.86-0.95) and decaffeinated coffee (HR per cup = 0.93, 95% CI, 0.87-0.99). The relation of coffee with endometrial cancer incidence varied significantly by HT use (P(interaction) = 0.03) with an association only apparent among HT-never users (HR comparing drinking >3 cups/day versus no cups = 0.54, 95% CI, 0.41-0.72; P(trend) = 0.0005). Endometrial cancer incidence appears to be reduced among women that habitually drink coffee, an association that does not differ according to caffeine content.

Spectrin isoforms: differential expression in normal hematopoiesis and alterations in neoplastic bone marrow disorders

Spectrins are large, rod-like, multifunctional molecules that participate in maintaining cell structure, signal transmission, and DNA repair. Because little is known about the role of spectrins in normal hematopoiesis and leukemogenesis, we immunohistochemically stained bone marrow biopsy specimens from 81 patients for αI, αII, βI, and βII spectrin isoforms in normal reactive marrow (NRM), myelodysplastic syndrome, myeloproliferative neoplasm, acute myeloid leukemia (AML) with well-characterized cytogenetic abnormalities, acute erythroid leukemia (EryL), and acute megakaryoblastic leukemia (MegL). In NRM, spectrin isoforms were differentially expressed according to cell lineage: αI and βI in erythroid precursors; αII and βII in granulocytes; and βI and βII in megakaryocytes. In contrast, 18 (44%) of 41 AMLs lacked αII spectrin and/or aberrantly expressed βI spectrin (P = .0398; Fisher exact test) and 5 (100%) of 5 EryLs expressed βII spectrin but lacked βI spectrin. The frequent loss and/or gain of spectrin isoforms in AMLs suggests a possible role for spectrin in leukemogenesis.

The relation of HLA genotype to hepatitis C viral load and markers of liver fibrosis in HIV-infected and HIV-uninfected women

BACKGROUND

Human leukocyte antigen (HLA) class I and II genotype is associated with clearance of hepatitis C virus (HCV) infection, but little is known regarding its relation with HCV viral load or risk of liver disease in patients with persistent HCV infection.

METHODS

High-resolution HLA class I and II genotyping was conducted in a prospective cohort of 519 human immunodeficiency virus (HIV)-seropositive and 100 HIV-seronegative women with persistent HCV infection. The end points were baseline HCV viral load and 2 noninvasive indexes of liver disease, fibrosis-4 (FIB-4), and the aspartate aminotransferase to platelet ratio index (APRI), measured at baseline and prospectively.

RESULTS

DQB1*0301 was associated with low baseline HCV load (β = -.4; 95% confidence interval [CI], -.6 to -.3; P < .00001), as well as with low odds of FIB-4-defined (odds ratio [OR], .5; 95% CI, .2-.9; P = .02) and APRI-defined liver fibrosis (OR, .5; 95% CI, .3-1.0; P = .06) at baseline and/or during follow-up. Most additional associations with HCV viral load also involved HLA class II alleles. Additional associations with FIB-4 and APRI primarily involved class I alleles, for example, the relation of B*1503 with APRI-defined fibrosis had an OR of 2.0 (95% CI, 1.0-3.7; P = .04).

CONCLUSIONS

HLA genotype may influence HCV viral load and risk of liver disease, including DQB1*0301, which was associated with HCV clearance in prior studies.

Transient versus persistent fear of falling in community-dwelling older adults: incidence and risk factors

OBJECTIVES

To investigate the incidence of fear of falling (FOF) and the risk factors associated with transient versus persistent FOF in community-dwelling older adults.

DESIGN

Prospective cohort study.

SETTING

Bronx County, New York.

PARTICIPANTS

Three hundred eighty participants without FOF at baseline in the Einstein Aging Study aged 70 and older.

MEASUREMENTS

FOF was assessed at baseline and during follow-up interviews at 2- to 3-month intervals for a minimum 2 years. Incident FOF was classified as transient or persistent FOF. Transient FOF was defined as new-onset FOF reported at only one interview, and persistent FOF was FOF reported at two or more interviews over a 2-year period.

RESULTS

Twenty-four-month cumulative incidence of incident FOF was 45.4%, with 60.0% of FOF being persistent. Predictors of incident FOF included female sex (adjusted hazard ratio (aHR)=1.55, 95% confidence interval (CI)=1.08-2.23), depressive symptoms (aHR=1.16, 95% CI=1.07-1.26), falls (aHR=1.50, 95% CI=1.01-2.21), and clinical gait abnormality (aHR=2.07, 95% CI=1.42-3.01). The proportion of participants with incident FOF increased linearly with increasing number of risk factors. Predictors for transient and persistent FOF were depressive symptoms and clinical gait abnormality. Female sex and previous falls were predictors of persistent but not transient FOF.

CONCLUSION

FOF status in older adults may change over time, with shared and distinct risk factors for persistent and transient FOF. Understanding the dynamic nature of FOF and these risk factors will help identify high-risk groups and design future intervention studies.

Molecular genotyping of Mycobacterium tuberculosis in Xi'an, China, using MIRU-VNTR typing

SETTING

The molecular genotyping of Mycobacterium tuberculosis is expected to lead to a better understanding of M. tuberculosis transmission in Xi'an, one of the largest cities in Western China.

OBJECTIVE

To characterize the population of M. tuberculosis strains circulating in Xi'an and to evaluate the feasibility of the mycobacterial interspersed repetitive units-variable number of tandem repeats (MIRU-VNTR) typing method.

DESIGN

A total of 195 M. tuberculosis clinical isolates from Xi'an were genotyped using spoligotyping and MIRU-VNTR.

RESULTS

Thirty-two different genotypes were identified by spoligotyping, with the Beijing family identified as the largest lineage (84.6%), followed by the T1 (3.08%), T2 (1.54%), H3 (1.03%) and U (1.03%) families. The Hunter-Gaston discriminatory index (HGDI) of spoligotyping is low (HGDI = 0.392). In contrast, 15-locus MIRU-VNTR shows a higher discriminatory power (HGDI = 0.998) than 12-locus MIRU-VNTR (HGDI = 0.948). By replacing the ETR C locus with the MIRU39 locus, the discriminatory power of 15-locus MIRU-VNTR is increased to 0.999.

CONCLUSIONS

The Beijing family accounts for the vast majority of M. tuberculosis isolates in Xi'an, China. The modified 15-locus MIRU-VNTR showed high HGDI and can be used as a first-line genotyping method in combination with spoligotyping in routine epidemiological investigations in Xi'an, China.

Iron homeostasis and distal colorectal adenoma risk in the prostate, lung, colorectal, and ovarian cancer screening trial

Red meat consumption has been positively associated with colorectal cancer; however, the biological mechanism underlying this relationship is not understood. Red meat is a major source of iron, which may play a role in colorectal carcinogenesis via increased crypt cell proliferation, cytotoxicity, and endogenous N-nitrosation. In a nested case-control study within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, we prospectively evaluated multiple iron exposure parameters, including dietary intake and serum measures of iron, ferritin, transferrin, total iron binding capacity (TIBC), and unsaturated iron binding capacity (UIBC) in relation to incident colorectal adenoma in 356 cases and 396 matched polyp-free controls. We also investigated variation in eight key genes involved in iron homeostasis in relation to colorectal adenoma in an additional series totaling 1,126 cases and 1,173 matched controls. We observed a positive association between red meat intake and colorectal adenoma [OR comparing extreme quartiles (OR(q4-q1)) = 1.59, 95% CI = 1.02-2.49, P(trend) = 0.03]. Serum TIBC and UIBC were inversely associated with colorectal adenoma (OR(q4-q1) = 0.57, 95% CI = 0.37-0.88, P(trend) = 0.03; and OR(q4-q1) = 0.62, 95% CI = 0.40-0.95, P(trend) = 0.04, respectively). Colorectal adenoma was not associated with serum ferritin, iron, or transferrin saturation or with polymorphisms in genes involved in iron homeostasis. Serum TIBC and UIBC, parameters that have a reciprocal relationship with overall iron load, were inversely related to colorectal adenoma, suggesting that individuals with lower iron status have a reduced risk of developing colorectal adenoma.

Endobronchial tuberculosis: an overview

Endobronchial tuberculosis (EBTB), of which the incidence has been increasing in recent years, is a special type of pulmonary tuberculosis. The endobronchial tuberculose focuses often injure the tracheobronchial wall and lead to tracheobronchial stenosis. The tracheobronchial stenosis may cause intractable tuberculosis and make patients become chronic infection sources of tuberculosis, or may even cause pulmonary complications and result in death. The etiological confirmation of Mycobacterium tuberculosis is most substantial for diagnosis. However, because the positive rate of acid-fast bacillus staining for sputum smears is low and the clinical and radiological findings are usually nondistinctive, the diagnosis of EBTB is often mistaken and delayed. For early diagnosis, a high index of awareness of this disease is required and the bronchoscopy should be performed as soon as possible in suspected patients. The eradication of Mycobacterium tuberculosis and the prevention of tracheobronchial stenosis are two most substantial treatment goals. To get treatment goals, the diagnosis must be established early and aggressive treatments must be performed before the disease progresses too far.

Ischemic post-conditioning attenuates the intestinal injury induced by limb ischemia/reperfusion in rats

The purpose of this study was to investigate the protective effects of ischemic post-conditioning on damage to the barrier function of the small intestine caused by limb ischemia-reperfusion injury. Male Wistar rats were randomly divided into 3 groups (N = 36 each): sham operated (group S), lower limb ischemia-reperfusion (group LIR), and post-conditioning (group PC). Each group was divided into subgroups (N = 6) according to reperfusion time: immediate (0 h; T1), 1 h (T2), 3 h (T3), 6 h (T4), 12 h (T5), and 24 h (T6). In the PC group, 3 cycles of reperfusion followed by ischemia (each lasting 30 s) were applied immediately. At all reperfusion times (T1-T6), diamine oxidase (DAO), superoxide dismutase (SOD), and myeloperoxidase (MPO) activity, malondialdehyde (MDA) intestinal tissue concentrations, plasma endotoxin concentrations, and serum DAO, tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) concentrations were measured in sacrificed rats. Chiu's pathology scores for small intestinal mucosa were determined under a light microscope and showed that damage to the small intestinal mucosa was lower in group PC than in group LIR. In group PC, tissue DAO and SOD concentrations at T2 to T6, and IL-10 concentrations at T2 to T5 were higher than in group LIR (P < 0.05); however, tissue MPO and MDA concentrations, and serum DAO and plasma endotoxin concentrations at T2 to T6, as well as TNF-α at T2 and T4 decreased significantly (P < 0.05). These results show that ischemic post-conditioning attenuated the permeability of the small intestines after limb ischemia-reperfusion injury. The protective mechanism of ischemic post-conditioning may be related to inhibition of oxygen free radicals and inflammatory cytokines that cause organ damage.

Reproductive history and risk of colorectal cancer in postmenopausal women

BACKGROUND

There are conflicting data regarding the role of sex hormones in colorectal cancer development. Whereas clinical trials data indicate that hormone therapy use reduces the risk of colorectal cancer, data from prospective cohort studies suggest that circulating estrogen levels are positively associated with colorectal cancer risk. A surrogate measure of lifetime estrogen exposure is reproductive history. We investigated the relationship between reproductive factors and the risk of colorectal cancer.

METHODS

Subjects were postmenopausal women enrolled in the National Institutes of Health-American Association of Retired Persons Diet and Health Study, a cohort of 214,162 individuals (aged 50-71 years) that included 2014 incident cases of colorectal cancer that occurred over a mean follow-up of 8.2 years. Questionnaires were used to collect data on reproductive factors, including ages at menarche, birth of first child, and menopause; parity, and use of oral contraceptives. Multivariable Cox proportional hazards models were constructed to examine associations between these reproductive factors and the risk of colorectal cancer, with adjustment for established colorectal cancer risk factors. All statistical tests were two-sided.

RESULTS

Age at menopause (≥ 55 vs < 40 years: hazard ratio [HR] = 1.50, 95% confidence interval [CI] = 1.23 to 1.83; P(trend) = .008) and age at birth of first child (≥ 30 vs ≤ 19 years: HR = 1.26, 95% CI = 1.01 to 1.58; P(trend) = .05) were positively associated with the risk of colorectal cancer. Among women with no history of hormone therapy use, age at menarche (≥ 15 vs 11-12 years: HR = 0.73, 95% CI = 0.57 to 0.94; P(trend) = .02) and parity (≥ 5 children vs no children: HR = 0.80, 95% CI = 0.63 to 1.02; P(trend) = .10) were inversely associated with the risk of colorectal cancer.

CONCLUSION

These data support a role for sex hormones in colorectal tumorigenesis and suggest that greater endogenous estrogen exposure may increase the risk of colorectal cancer in postmenopausal women.

A prospective study of inflammation markers and endometrial cancer risk in postmenopausal hormone nonusers

BACKGROUND

It is hypothesized that inflammation may mediate the relationship between obesity and endometrial cancer risk. We examined the associations of three inflammation markers, C-reactive protein (CRP), interleukin (IL)-6 and tumor necrosis factor (TNF)-α, with risk of endometrial cancer.

METHODS

A case-cohort study was nested within the Women's Health Initiative, a cohort of postmenopausal women. Baseline plasma samples of 151 incident endometrial cancer cases and 301 subcohort subjects not using hormones were assayed.

RESULTS

CRP, but not IL-6 or TNF-α, was positively associated with endometrial cancer risk after adjusting for age and BMI [HR comparing extreme quartiles (HR q(4)-q(1)) = 2.29; 95% CI = 1.13-4.65; P(trend) = 0.012). After additional adjustment for estradiol and insulin, this association was attenuated (HRq(4)-q(1) = 1.70; 95% CI = 0.78-3.68; P(trend) = 0.127). Obesity (BMI ≥ 30 kg/m(2)) was associated with endometrial cancer risk in an age-adjusted model. The obesity effect was reduced by 48%, 67%, and 77% when either estradiol, CRP, or insulin, respectively, was included in the model, and it became null when all three factors were adjusted for simultaneously.

CONCLUSIONS

The association between inflammation, as indicated by a relatively high level of CRP, and endometrial cancer risk may partially be explained by hyperinsulinemia and elevated estradiol. Nevertheless, all three factors contribute to and mediate the link between obesity and endometrial cancer in postmenopausal women not using hormones.

IMPACT

The association between obesity and endometrial cancer risk in postmenopausal women may be attributed to inflammation, insulin resistance, and elevated estrogen.

T cell activation predicts carotid artery stiffness among HIV-infected women

OBJECTIVES

HIV disease is associated with increased arterial stiffness, which may be related to inflammation provoked by HIV-related immune perturbation. We assessed the association of T cell markers of immune activation and immunosenescence with carotid artery stiffness among HIV-infected women.

METHODS

Among 114 HIV-infected and 43 HIV-uninfected women, we measured CD4+ and CD8+ T cell populations expressing activation (CD38+HLA-DR+) and senescence (CD28-CD57+) markers. We then related these measures of immune status with parameters of carotid artery stiffness, including decreased distensibility, and increased Young's elastic modulus, as assessed by B-mode ultrasound.

RESULTS

HIV infection was associated with increased CD4+ T cell activation, CD8+ T cell activation and CD8+ T cell senescence. Among HIV-infected women, adjusted for age, HIV medications, and vascular risk factors, higher CD4+CD38+HLA-DR+ T cell frequency was associated with decreased carotid artery distensibility (β=-2.00, 95% confidence interval [CI]=-3.86, -0.14, P=0.04) and increased Young's modulus (β=1.00, 95% CI=0.03, 1.97, P=0.04). These associations were affected little by further adjustment for CD4+ T cell count and viral load. Among HIV-infected women, higher frequencies of immunosenescent T cells, including CD4+CD28-CD57+ and CD8+CD28-CD57+ T cells, were also associated with decreased arterial distensibility. Among HIV-uninfected women, frequencies of activated or senescent T cells were not significantly associated with measures of carotid stiffness.

DISCUSSION

T cell activation and senescence are associated with arterial stiffness, suggesting that pro-inflammatory populations of T cells may produce functional or structural vascular changes in HIV-infected women.

Apparent diffusion coefficient histogram analysis stratifies progression-free survival in newly diagnosed bevacizumab-treated glioblastoma

BACKGROUND AND PURPOSE

Currently it is difficult to predict tumor response to anti-angiogenic therapy in individual patients. Our aim was to determine if ADC histogram analysis can stratify progression-free and overall survival in patients with newly diagnosed GBM treated "up-front" (ie, before tumor recurrence) with bevacizumab.

MATERIALS AND METHODS

Up-front bevacizumab-treated and control patients (n = 59 and 62, respectively) with newly diagnosed GBM were analyzed by using an ADC histogram approach based on enhancing tumor. Progression-free and overall survival was determined by using Cox proportional HRs and the Kaplan-Meier method with logrank and Wilcoxon tests.

RESULTS

For up-front bevacizumab-treated patients, lower ADC(L) was associated with significantly longer progression-free survival (median, 459 days for ADC(L) < 1200 versus 315 days for ADC(L) ≥ 1200 10(-6)mm(2)/s; P = .008, logrank test) and trended with longer overall survival (581 versus 429 days, P = .055). ADC values did not stratify progression-free or overall survival for patients in the control group (P = .92 and P = .22, respectively). Tumors with MGMT promoter methylation had lower ADC(L) values than unmethylated tumors (mean, 1071 versus 1183 10(-6)mm(2)/s; P = .01, 2-group t test).

CONCLUSIONS

Pretreatment ADC histogram analysis can stratify progression-free survival in bevacizumab-treated patients with newly diagnosed GBM. Lower ADC is associated with tumor MGMT promoter methylation, which may, in part, account for the favorable outcome associated with low ADC(L) tumors.

T cell activation and senescence predict subclinical carotid artery disease in HIV-infected women

Background. Individuals infected with human immunodeficiency virus (HIV) have increased risk of cardiovascular events. It is unknown whether T cell activation and senescence, 2 immunologic sequelae of HIV infection, are associated with vascular disease among HIV-infected adults.

Methods. T cell phenotyping and carotid ultrasound were assessed among 115 HIV-infected women and 43 age- and race/ethnicity-matched HIV-uninfected controls participating in the Women's Interagency HIV Study. Multivariate analyses were used to assess the association of T cell activation (CD38⁺HLA-DR⁺) and senescence (CD28⁻CD57⁺) with subclinical carotid artery disease.

Results. Compared with HIV-uninfected women, frequencies of CD4⁺CD38⁺HLA-DR⁺, CD8⁺CD38⁺HLA-DR⁺, and CD8⁺CD28⁻CD57⁺ T cells were higher among HIV-infected women, including those who achieved viral suppression while receiving antiretroviral treatment. Among HIV-infected women, adjusted for age, antiretroviral medications, and viral load, higher frequencies of activated CD4⁺ and CD8⁺ T cells and immunosenescent CD8⁺ T cells were associated with increased prevalence of carotid artery lesions (prevalence ratio_lesions associated with activated CD4⁺ T cells, 1.6 per SD [95% confidence interval {CI}, 1.1–2.2]; P = .02; prevalence ratio_lesions associated with activated CD8⁺ T cells, 2.0 per SD [95% CI, 1.2–3.3]; P < .01; prevalence ratio_lesions associated with senescent CD8⁺ T cells, 1.9 per SD [95% CI, 1.1–3.1]; P = .01).

Conclusions. HIV-associated T cell changes are associated with subclinical carotid artery abnormalities, which may be observed even among those patients achieving viral suppression with effective antiretroviral therapy.

A prospective evaluation of C-reactive protein levels and colorectal adenoma development

BACKGROUND

Inflammation is hypothesized to play a role in colorectal tumorigenesis. Circulating levels of C-reactive protein (CRP), a serologic marker of the inflammatory response, have been positively associated with colorectal cancer development in some studies; however, there are limited data on the relation of CRP with colorectal adenomas, established precursors of colorectal cancer.

METHODS

A nested case-control investigation of CRP levels and incident colorectal adenoma was conducted in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, a randomized trial of 154,942 individuals designed to test the efficacy of flexible sigmoidoscopy on colorectal cancer mortality when performed once, and then repeated 3 to 5 years later. Serum CRP levels were measured in baseline blood specimens from participants who were free of polyps in the left-sided colorectum at the baseline screening procedure, but who were found at the subsequent screen to have at least one colorectal adenoma (n=356), and in a set of polyp-free, frequency-matched controls (n=396).

RESULTS

In a multivariable logistic regression model that included established colorectal adenoma risk factors, a 1-unit increase in log CRP level was associated with a 15% reduction in risk of developing colorectal adenoma (OR=0.85, 95% CI, 0.75-0.98, Ptrend=0.01). This association did not differ according to body size, smoking behavior, gender, use of nonsteroidal antiinflammatory drugs, or adenoma location.

CONCLUSIONS

High circulating CRP levels may be protective against colorectal adenoma development.

IMPACT

Though at contrast with mechanistic data on inflammation and colorectal tumorigenesis, this finding is not inconsistent with prior results on CRP and colorectal adenoma and warrants further investigation.

Outcomes after an excisional procedure for cervical intraepithelial neoplasia in HIV-infected women

OBJECTIVE

To determine predictors of treatment failure and recurrence after surgical excisional procedures for CIN in HIV-infected women.

METHODS

A retrospective cohort study was conducted in which 136 eligible HIV-infected women treated for CIN between 1999 and 2005 were included. Data were abstracted from charts and computer databases. Treatment failures were defined as the presence of CIN 1+ at initial follow-up. Recurrences were defined as the presence of CIN 1+ subsequent to initial normal follow-up.

RESULTS

Treatment failure at initial follow-up was common, occurring in 51% of CIN 1 and 55% of CIN 2+. Most lesions detected at treatment failure were high grade (>70%), regardless of the grade of initial lesion. Significant risk factors for treatment failure were loop electrosurgical excision procedure (LEEP) compared to cold knife conization (RR=1.76; 95% CI: 1.15-2.64), and low CD4+ count (p=0.04). Among those with an initial normal clinical evaluation, 55% eventually recurred. As with treatment failure, most lesions detected at recurrence were high grade. Risk factors for recurrence included use of LEEP (hazard ratio [HR]=3.38; 95% CI: 1.55-7.39), higher HIV RNA level, and the presence of positive margins at treatment (HR=6.12; 95% CI: 1.90-19.73).

CONCLUSIONS

Most CIN treatment of HIV-infected women studied either failed or resulted in recurrence. Of particular concern, many of these subsequent lesions were high grade. Conization, however, was associated with significantly less failure/recurrence than LEEP. Clinicians treating CIN in HIV-infected women should avoid raising expectations of cure and instead focus on the achievable goal of cancer prevention until there are better therapies for this patient population.

Conventional and robust quantitative gait norms in community-dwelling older adults

OBJECTIVES

To develop and compare norms for widely used gait parameters in adults aged 70 and older using cross-sectional (conventional) and longitudinal (robust) approaches accounting for important confounders such as disease effects on gait.

DESIGN

Cohort study.

SETTING

General community.

PARTICIPANTS

Community-dwelling older adults (> 70, N = 824) without dementia or disability.

MEASUREMENTS

Eight quantitative gait parameters measured using an instrumented walkway.

RESULTS

Of the 824 subjects (conventional normal (CN) sample), 304 were included in a "robust normal" (RN) sample after excluding those with prevalent or incident clinical gait abnormalities developing within 1 year of the baseline assessment to account for disease effects on gait performance. Descriptively, the RN sample showed better performance on all selected gait variables than the CN sample. For instance, mean gait velocity ± standard deviation was 105.9 ± 17.9 cm/s in the RN sample, compared with 93.3 ± 23.2 cm/s in the overall CN sample. Applying one standard deviation below the mean (70.1 cm/s) derived from the CN sample to define slow gait, 15.9% (131) in the overall cohort were classified as abnormal, whereas the RN cut-off (88.0 cm/s) classified 39.7% (327) in the overall cohort as abnormal.

CONCLUSION

Cross-sectional conventional norms may underestimate gait performance in aging. Longitudinal robust norms provide more-accurate estimates of normal gait performance and thus may improve early detection of gait disorders in older adults.

Comparison of BIOMED-2 versus laboratory-developed polymerase chain reaction assays for detecting T-cell receptor-gamma gene rearrangements

Detecting clonal T-cell receptor (TCR)-gamma gene rearrangements (GRs) is an important adjunct test for diagnosing T-cell lymphoma. We compared a recently described assay (BIOMED-2 protocol), which targets multiple variable (V) gene segments in two polymerase chain reaction (PCR) reactions (multi-V), with a frequently referenced assay that targets a single V gene segment in four separate PCR reactions (mono-V). A total of 144 consecutive clinical DNA samples were prospectively tested for T-cell clonality by PCR using laboratory-developed mono-V and commercial multi-V primer sets for TCR-gamma GR. The combination of TCR-beta, mono-V TCR-gamma and multi-V TCR-gamma detected more clonal cases (68/144, 47%) than any individual PCR assay. We detected clonal TCR-beta GR in 47/68 (69%) cases. Using either mono-V or multi-V TCR-gamma primers, the sensitivities for detecting clonality were 52/68 (76%) or 51/68 (75%). Using both mono-V and multi-V TCR-gamma primers improved the sensitivity for detecting clonality, 60/68 (88%). Combining either mono-V or multi-V TCR-gamma primers with TCR-beta primers also improved the sensitivity, 64/68 (94%). Significantly, TCR-gamma V11 GRs could only be detected using the mono-V-PCR primers. We conclude that using more than one T-cell PCR assay can enhance the overall sensitivity for detecting T-cell clonality.