Modified SuperCurve Method for Analysis of Reverse-Phase Protein Array Data

Reverse-phase protein arrays (RPPAs) are widely used in biological and biomedical fields of study. One of the most popular analytic methods in RPPA data analysis is the SuperCurve method, which requires estimation of the background fluorescence level. This estimation is usually not accurate and has sample bias and spatial bias. Here, we propose a taking-the-difference method to overcome this problem. Briefly, for each two consecutive RPPA cycles, we subtract the later cycle from the earlier cycle, transforming the m-cycle data into m-1 cycle of data. This removes most of the background fluorescence noise. We then use the m-1 cycle of data to fit a new model accordingly derived from the SuperCurve model. To evaluate our proposed method, we compare the accuracy and precision between our proposed model and the original SuperCurve model by testing them on both real and simulated datasets. For both situations, our modified model shows improved results. The modified SuperCurve method is easy to perform and the taking-the-difference idea is recommended for application to all current methods of RPPA data analysis.

Medication Routines and Adherence Among Hypertensive African Americans

Poor adherence to prescribed medication regimens remains an important challenge preventing successful treatment of cardiovascular diseases such as hypertension. While studies have documented differences in the time of day or weekday vs weekend on medication adherence, no study has examined whether having a medication-taking routine contributes to increased medication adherence. The purpose of this study was to: (1) identify patients' sociodemographic factors associated with consistent medication-taking routine; (2) examine associations between medication-taking consistency, medication adherence, and blood pressure (BP) control. The study included black patients with hypertension (n = 190; 22 men and 168 women; age, mean±standard deviation 54 ± 12.08 years) who completed a practice-based randomized controlled trial. Findings showed that medication-taking consistency was significantly associated with better medication adherence (F = 9.54, P = .002). Associations with the consistency index were not statistically significant for diastolic BP control (odds ratio, 1.319; 95% confidence interval, 0.410-4.246; P = .642) and systolic BP control (odds ratio, 0.621; 95% confidence interval, 0.195-1.974; P = .419).

Long-term effectiveness of accelerated hepatitis B vaccination schedule in drug users

OBJECTIVES

We demonstrated the effectiveness of an accelerated hepatitis B vaccination schedule in drug users.

METHODS

We compared the long-term effectiveness of accelerated (0-1-2 months) and standard (0-1-6 months) hepatitis B vaccination schedules in preventing hepatitis B virus (HBV) infections and anti-hepatitis B (anti-HBs) antibody loss during 2-year follow-up in 707 drug users (HIV and HBV negative at enrollment and completed 3 vaccine doses) from February 2004 to October 2009.

RESULTS

Drug users in the accelerated schedule group had significantly lower HBV infection rates, but had a similar rate of anti-HBs antibody loss compared with the standard schedule group over 2 years of follow-up. No chronic HBV infections were observed. Hepatitis C positivity at enrollment and age younger than 40 years were independent risk factors for HBV infection and antibody loss, respectively.

CONCLUSIONS

An accelerated vaccination schedule was more preferable than a standard vaccination schedule in preventing HBV infections in drug users. To overcome the disadvantages of a standard vaccination schedule, an accelerated vaccination schedule should be considered in drug users with low adherence. Our study should be repeated in different cohorts to validate our findings and establish the role of an accelerated schedule in hepatitis B vaccination guidelines for drug users.

Bone marrow characteristics associated with changes in infarct size after STEMI: a biorepository evaluation from the CCTRN TIME trial

RATIONALE

Despite significant interest in bone marrow mononuclear cell (BMC) therapy for ischemic heart disease, current techniques have resulted in only modest benefits. However, selected patients have shown improvements after autologous BMC therapy, but the contributing factors are unclear.

OBJECTIVE

The purpose of this study was to identify BMC characteristics associated with a reduction in infarct size after ST-segment-elevation-myocardial infarction.

METHODS AND RESULTS

This prospective study comprised patients consecutively enrolled in the CCTRN TIME (Cardiovascular Cell Therapy Research Network Timing in Myocardial Infarction Evaluation) trial who agreed to have their BMCs stored and analyzed at the CCTRN Biorepository. Change in infarct size between baseline (3 days after percutaneous coronary intervention) and 6-month follow-up was measured by cardiac MRI. Infarct-size measurements and BMC phenotype and function data were obtained for 101 patients (mean age, 56.5 years; mean screening ejection fraction, 37%; mean baseline cardiac MRI ejection fraction, 45%). At 6 months, 75 patients (74.3%) showed a reduction in infarct size (mean change, -21.0±17.6%). Multiple regression analysis indicated that infarct size reduction was greater in patients who had a larger percentage of CD31(+) BMCs (P=0.046) and in those with faster BMC growth rates in colony-forming unit Hill and endothelial-colony forming cell functional assays (P=0.033 and P=0.032, respectively).

CONCLUSIONS

This study identified BMC characteristics associated with a better clinical outcome in patients with segment-elevation-myocardial infarction and highlighted the importance of endothelial precursor activity in regenerating infarcted myocardium. Furthermore, it suggests that for these patients with segment-elevation-myocardial infarction, myocardial repair was more dependent on baseline BMC characteristics than on whether the patient underwent intracoronary BMC transplantation.

CLINICAL TRIAL REGISTRATION INFORMATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00684021.

Slow and steady cell shrinkage reduces osmotic stress in bovine and murine oocyte and zygote vitrification

STUDY QUESTION

Does the use of a new cryoprotectant agent (CPA) exchange protocol designed to minimize osmotic stress improve oocyte or zygote vitrification by reducing sublethal cryodamage?

SUMMARY ANSWER

The use of a new CPA exchange protocol made possible by automated microfluidics improved oocyte and zygote vitrification with superior morphology as indicated by a smoother cell surface, higher sphericity, higher cytoplasmic lipid retention, less cytoplasmic leakage and higher developmental competence compared with conventional methods.

WHAT IS KNOWN ALREADY

The use of more 'steps' of CPA exposure during the vitrification protocol increases cryosurvival and development in the bovine model. However, such an attempt to eliminate osmotic stress is limited by the practicality of performing numerous precise pipetting steps in a short amount of time.

STUDY DESIGN, SIZE, DURATION

Murine meiotically competent germinal vesicle intact oocytes and zygotes were harvested from the antral follicles in ovaries and ampulla, respectively. Bovine ovaries were obtained from a local abattoir at random stages of the estrous cycle. A total of 110 murine oocytes, 802 murine zygotes and 52 bovine oocytes were used in this study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Microfluidic devices were fabricated using conventional photo- and soft-lithography. CPAs used were 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for equilibration solution and 15% EG, 15% DMSO and 0.5 M sucrose for vitrification solution. End-point analyses include mathematical modeling using Kedem-Katchalsky equations, morphometrics assessed by conventional and confocal microscopy, cytoplasmic lipid quantification by nile red staining, cytoplasmic leakage quantification by fluorescent dextran intercalation and developmental competence analysis by 96 h embryo culture and blastomere quantification.

MAIN RESULTS AND THE ROLE OF CHANCE

The automated microfluidics protocol decreased the shrinkage rate of the oocyte and zygote by 13.8 times over its manual pipetting alternative. Oocytes and zygotes with a lower shrinkage rate during CPA exposure experienced less osmotic stress resulting in better morphology, higher cell quality and improved developmental competence. This microfluidic procedure resulted in murine zygotes with a significantly smoother cell surface (P < 0.001), more spherical cellular morphology (P < 0.001), increased cytoplasmic lipid retention in vitrified and warmed bovine oocytes (P < 0.01), decreased membrane perforations and cytoplasmic leakage in CPA-exposed murine zygotes (P < 0.05) and improved developmental competence of vitrified and warmed murine zygotes (P < 0.05) than CPA exposure using the current clinically used manual pipetting method.

LIMITATIONS, REASONS FOR CAUTION

It is necessary to design the microfluidic device to be more user-friendly for widespread use.

WIDER IMPLICATIONS OF THE FINDINGS

The theory and approach of eliminating osmotic stress by decreasing shrinkage rate is complementary to the prevalent osmotic stress theory in cryobiology which focuses on a minimum cell volume at which the cells shrink. The auto-microfluidic protocol described here has immediate applications for improving animal and human oocyte, zygote and embryo cryopreservation. On a fundamental level, the clear demonstration that at the same minimum cell volume, cell shrinkage rate affects sublethal damage should be broadly useful for cryobiology.

STUDY FUNDING/COMPETING INTERESTS

This project was funded by the National Institutes of Health and the University of Michigan Reproductive Sciences Program. The authors declare no conflicts of interest.

Maternal exposure to fine particulate pollution during narrow gestational periods and newborn health in Harris County, Texas

It remains unclear when the fetus is most susceptible to the effects of particulate air pollution. We conducted a population-based study in a large urban area to evaluate associations between preterm birth (PTB) and fetal growth and exposures to fine particles (PM(2.5)) during narrow periods of gestation. We identified 177,816 births during 2005-2007 among mothers who resided in Harris County, Texas at the time of delivery. We created three mutually exclusive categories of mildly (33-36 completed weeks of gestation), moderately (29-32 weeks of gestation), and severely (20-28 weeks of gestation) PTB, and among full term infants, we identified those who were born small for their gestational age. Using routine air monitoring data, we generated county-level daily time series of estimated ambient air levels of PM2.5 and then computed exposure metrics during every 4 weeks of a mother's pregnancy. We evaluated associations in each 4-week period using multiple logistic regression. A 10 μg/m(3) increase in PM(2.5) exposure in the first 4 weeks of pregnancy significantly increased the odds of mildly, moderately and severely PTB by 16, 71 and 73 %, respectively. Associations were stronger when infants with birth defects were excluded. Our findings indicate an association between PM(2.5) and PTB, with stronger associations for moderately and severely PTB infants. Efforts should continue to implement stricter air quality standards and improve ambient air quality.

Genetic variant predicts bevacizumab-induced hypertension in ECOG-5103 and ECOG-2100

BACKGROUND

Bevacizumab has broad anti-tumour activity, but substantial risk of hypertension. No reliable markers are available for predicting bevacizumab-induced hypertension.

METHODS

A genome-wide association study (GWAS) was performed in the phase III bevacizumab-based adjuvant breast cancer trial, ECOG-5103, to evaluate for an association between genotypes and hypertension. GWAS was conducted in those who had experienced systolic blood pressure (SBP) >160 mm Hg during therapy using binary analysis and a cumulative dose model for the total exposure of bevacizumab. Common toxicity criteria (CTC) grade 3-5 hypertension was also assessed. Candidate SNP validation was performed in the randomised phase III trial, ECOG-2100.

RESULTS

When using the phenotype of SBP>160 mm Hg, the most significant association in SV2C (rs6453204) approached and met genome-wide significance in the binary model (P=6.0 × 10(-8); OR=3.3) and in the cumulative dose model (P=4.7 × 10(-8); HR=2.2), respectively. Similar associations with rs6453204 were seen for CTC grade 3-5 hypertension but did not meet genome-wide significance. Validation study from ECOG-2100 demonstrated a statistically significant association between this SNP and grade 3/4 hypertension using the binary model (P-value=0.037; OR=2.4).

CONCLUSIONS

A genetic variant in SV2C predicted clinically relevant bevacizumab-induced hypertension in two independent, randomised phase III trials.

Detailed analysis of bone marrow from patients with ischemic heart disease and left ventricular dysfunction: BM CD34, CD11b, and clonogenic capacity as biomarkers for clinical outcomes

RATIONALE

Bone marrow (BM) cell therapy for ischemic heart disease (IHD) has shown mixed results. Before the full potency of BM cell therapy can be realized, it is essential to understand the BM niche after acute myocardial infarction (AMI).

OBJECTIVE

To study the BM composition in patients with IHD and severe left ventricular (LV) dysfunction.

METHODS AND RESULTS

BM from 280 patients with IHD and LV dysfunction were analyzed for cell subsets by flow cytometry and colony assays. BM CD34(+) cell percentage was decreased 7 days after AMI (mean of 1.9% versus 2.3%-2.7% in other cohorts; P<0.05). BM-derived endothelial colonies were significantly decreased (P<0.05). Increased BM CD11b(+) cells associated with worse LV ejection fraction (LVEF) after AMI (P<0.05). Increased BM CD34(+) percentage associated with greater improvement in LVEF (+9.9% versus +2.3%; P=0.03, for patients with AMI and +6.6% versus -0.02%; P=0.021 for patients with chronic IHD). In addition, decreased BM CD34(+) percentage in patients with chronic IHD correlated with decrement in LVEF (-2.9% versus +0.7%; P=0.0355).

CONCLUSIONS

In this study, we show a heterogeneous mixture of BM cell subsets, decreased endothelial colony capacity, a CD34+ cell nadir 7 days after AMI, a negative correlation between CD11b percentage and postinfarct LVEF, and positive correlation of CD34 percentage with change in LVEF after cell therapy. These results serve as a possible basis for the small clinical improvement seen in autologous BM cell therapy trials and support selection of potent cell subsets and reversal of comorbid BM impairment.

CLINICAL TRIAL REGISTRATIONS URL

http://www.clinicaltrials.gov. Unique identifiers: NCT00684021, NCT00684060, and NCT00824005.

Phenotypic effects of maternal immune activation and early postnatal milieu in mice mutant for the schizophrenia risk gene neuregulin-1

Risk of schizophrenia is likely to involve gene × environment (G × E) interactions. Neuregulin 1 (NRG1) is a schizophrenia risk gene, hence any interaction with environmental adversity, such as maternal infection, may provide further insights into the basis of the disease. This study examined the individual and combined effects of prenatal immune activation with polyriboinosinic-polyribocytidilic acid (Poly I:C) and disruption of the schizophrenia risk gene NRG1 on the expression of behavioral phenotypes related to schizophrenia. NRG1 heterozygous (NRG1 HET) mutant breeding pairs were time-mated. Pregnant dams received a single injection (5mg/kg i.p.) of Poly I:C or vehicle on gestation day 9 (GD9). Offspring were then cross-fostered to vehicle-treated or Poly I:C-treated dams. Expression of schizophrenia-related behavioral endophenotypes was assessed at adolescence and in adulthood. Combining NRG1 disruption and prenatal environmental insult (Poly I:C) caused developmental stage-specific deficits in social behavior, spatial working memory and prepulse inhibition (PPI). However, combining Poly I:C and cross-fostering produced a number of behavioral deficits in the open field, social behavior and PPI. This became more complex by combining NRG1 deletion with both Poly I:C exposure and cross-fostering, which had a robust effect on PPI. These findings suggest that concepts of G × E interaction in risk of schizophrenia should be elaborated to multiple interactions that involve individual genes interacting with diverse biological and psychosocial environmental factors over early life, to differentially influence particular domains of psychopathology, sometimes over specific stages of development.

Use of latent class analysis approach to describe drug and sexual HIV risk patterns among injection drug users in Houston, Texas

Following latent class analysis (LCA) approach we examined patterns of HIV risk using two related domains of behavior: drug use, and sexual activity among 523 injection drug users (IDUs) recruited into the 2009 National HIV behavioral surveillance system. Using posterior probability of endorsing six drug and sexual items, we identified three distinct classes representing underlying HIV risk. Forty percent of our participants were at highest risk, 25 % at medium risk, and 35 % at lowest risk for HIV infection. Compared to the Lowest-risk class members, the Highest-risk class members had riskier drug and sexual behaviors and had higher prevalence of HIV cases (6 vs. 4 %). This analysis underscores the merit of LCA to empirically identify risk patterns using multiple indicators and our results show HIV risk varies among IDUs as their drug and sexual behaviors. Tailored and targeted prevention and treatment interventions for the dual risk pattern are required rather than for drug or sexual risk in silos.

Effects of newly developed chemotherapy regimens, comorbidities, chemotherapy-related toxicities on the changing patterns of the leading causes of death in elderly patients with colorectal cancer

BACKGROUND

Abundant evidences have shown that newly developed chemotherapy regimens improved 5-year survival rate of colorectal cancer (CRC) patients over the past two decades. However, their impact on risk of death from leading causes among elderly patients is still poorly understood.

PATIENTS AND METHODS

A retrospective cohort study of 69 718 elderly CRC patients with their first primary tumors in 1992-2009, identified from the 12 areas of Surveillance, Epidemiology, and End Results-Medicare linked database with their Medicare claims up to 2010. Multivariate Cox regression models were used to assess the effect of newly developed chemotherapy regimens, comorbidities, and chemotherapy related toxicities on cause-specific death and their temporal patterns among elderly CRC patients.

RESULTS

The leading causes of death among CRC patients were CRC, circulation disorders, and secondary cancers, which accounted for 51.4%, 25%, and 4.6% of all-cause death, respectively. Patients diagnosed in more recent diagnostic time periods were significantly less likely to die of CRC [period 2: 5-year hazard ratio = 0.94, 95% confidence interval (CI) 0.90-0.97; period 3: 0.86, 0.83-0.90], circulation disorders (period 2: 0.94, 0.88-1.00; period 3: 0.80, 0.75-0.87), and more likely to die of secondary cancer (period 3: 1.42, 1.20-1.68) compared with those diagnosed in period 1. Charlson comorbidities index and the selected pre-existing comorbidities were significantly associated with increased 5-year risk of death from all three leading causes. Both hematological and gastric toxicity were associated with reduced risk of death from CRC and circulation disorders. The association between diagnostic time period and risk reduction in death from CRC depended on chemotherapy treatment (P < 0.0001). Subgroup analyses showed that the chemotherapy-dependent significant risk reduction was seen in patients with stage II-III CRC, patients without comorbidities, and patients without toxicities (P < 0.0001 for all).

CONCLUSION

The newly developed chemotherapy regimens were associated with the decreased risk of mortality from CRC.

Enrichment of ovarian cancer stem-like cells is associated with epithelial to mesenchymal transition through an miRNA-activated AKT pathway

OBJECTIVES

Evidence has indicated that ovarian epithelial cancer-type cells under serum-free culture conditions can form spheroid cells and exhibit characteristics expected of cancer stem-like cells (CSCs). However, the mechanism by which differentiated ovarian cancer cells acquire stem-cell properties during CSC enrichment has needed to be elucidated. Recent studies have demonstrated that induction of epithelial to mesenchymal transition (EMT) can generate CSCs and be associated with tumour aggressiveness and metastasis.

MATERIALS AND METHODS

Ovarian epithelial cancer cell lines, SKOV3 and HO8920, were cultured for spheroid cells and adherent cells. CSC enrichment was investigated using MTT assay, flow cytometery and qRT-PCR and expression level of PI3K/AKT pathway components was analysed by western blotting.

RESULTS

Compared to adherent cells, the spheroid cells expressed mesenchymal markers highly and exhibited significantly more motility; we also observed increases in phosphate AKT1 levels in the spheroid cells. Moreover, transfection of miR-20a or miR-200c led to corresponding reduction in endogenous PTEN protein, while AKT1 and phosphate AKT1 levels were upregulated in miRNAs-transfected cells. Finally, PI3K/AKT pathway inhibitor LY294002 reduced expressions of mesenchymal markers and stem-cell gene activity in spheroid cells, enhancing sensitivity of spheroid cells to paclitaxel treatment.

CONCLUSIONS

Our findings demonstrate that EMT contributed to enrichment of ovarian CSCs in vitro, making EMT targeting in epithelial ovarian cancer a novel therapeutic option.

KLF5 strengthens drug resistance of ovarian cancer stem-like cells by regulating survivin expression

OBJECTIVES

Ovarian cancer stem-like cells (CSCs), which can form non-adherent sphere cells in a stem-cell selection culture system, exhibit stemness and drug resistance to chemotherapeutics, which are properties not observed in differentiated cells. Recent studies have demonstrated that Kruppel-like factor 5 (KLF5) is involved in cell proliferation and mediates cell survival and tumourigenesis. Here, we investigated the role of KLF5 and its downstream target survivin, in strengthening drug resistance of ovarian CSCs.

MATERIALS AND METHODS

Ovarian cancer cell line SKOV3 was cultured under serum-free conditions and differentiating conditions to promote formation of sphere cells and differentiated cells, respectively. siRNA-KLF5 was used to knock down KLF5, and survivin expression vector was used to overexpress survivin. Cells were further analysed by qPCR, immunofluorescence staining and western blotting. Chromatin immunoprecipitation (ChIP) assay and electrophoretic mobility shift assay (EMSA) were performed to investigate the relationship between KLF5 and survivin expression. Drug resistance was examined by MTT and apoptosis assays.

RESULTS

KLF5 was highly expressed in the ovarian cancer cell line SKOV3 sphere cells, accompanied by elevated survivin expression. Silencing KLF5 by small interfering RNA in sphere cells down-regulated survivin expression, which also sensitized the sphere cells to apoptosis induced by chemotherapeutic drugs (cisplatin or paclitaxel). Furthermore, ChIP assay, survivin overexpression and EMSA results indicated that KLF5 controlled survivin expression by directly binding the surivin promoter in the cells.

CONCLUSIONS

The KLF5-mediated signalling pathway is a potential target for elimination of ovarian CSCs.

Temporal trends in the leading causes of death among a large national cohort of patients with colorectal cancer from 1975 to 2009 in the United States

PURPOSE

To assess the distribution of proportion of deaths from causes other than colorectal cancer (CRC) over time and temporal trends of cause-specific cumulative incidence of death due to six leading causes in patients with CRC.

METHODS

Overall, 375,462 patients with CRC in nine Surveillance, Epidemiology, and End Results registries from 1975 to 2009 were included. Competing risks proportional hazards regression was used to examine the effect of diagnostic periods on the risk of cause-specific death.

RESULTS

From 1975 to 2009 by 5-year interval, the proportion of deaths from causes other than CRC increased significantly with diagnostic periods according to the lengths of follow-up (P < .0001). The 5-year risk of death significantly decreased with diagnostic periods for all-cause, CRC, and circulation diseases among all age groups (<65, 65-74, and ≥75 years) but increased for chronic obstructive pulmonary disease, diabetes, and Alzheimer disease among patients aged 65 years or older.

CONCLUSIONS

Deaths due to causes other than CRC increased significantly over time regardless of tumor stage and site but more sharply in those with early-stage and distal colon cancer. The increasing leading causes of death are chronic obstructive pulmonary disease, diabetes, and Alzheimer disease, which may be prevented or delayed substantially by modification or intervention in lifestyle or other factors.

A hybrid method in combining treatment effects from matched and unmatched studies

The most common data structures in the biomedical studies have been matched or unmatched designs. Data structures resulting from a hybrid of the two may create challenges for statistical inferences. The question may arise whether to use parametric or nonparametric methods on the hybrid data structure. The Early Treatment for Retinopathy of Prematurity study was a multicenter clinical trial sponsored by the National Eye Institute. The design produced data requiring a statistical method of a hybrid nature. An infant in this multicenter randomized clinical trial had high-risk prethreshold retinopathy of prematurity that was eligible for treatment in one or both eyes at entry into the trial. During follow-up, recognition visual acuity was accessed for both eyes. Data from both eyes (matched) and from only one eye (unmatched) were eligible to be used in the trial. The new hybrid nonparametric method is a meta-analysis based on combining the Hodges-Lehmann estimates of treatment effects from the Wilcoxon signed rank and rank sum tests. To compare the new method, we used the classic meta-analysis with the t-test method to combine estimates of treatment effects from the paired and two sample t-tests. We used simulations to calculate the empirical size and power of the test statistics, as well as the bias, mean square and confidence interval width of the corresponding estimators. The proposed method provides an effective tool to evaluate data from clinical trials and similar comparative studies.

Was mandatory quarantine necessary in China for controlling the 2009 H1N1 pandemic?

The Chinese government enforced mandatory quarantine for 60 days (from 10 May to 8 July 2009) as a preventative strategy to control the spread of the 2009 H1N1 pandemic. Such a prevention strategy was stricter than other non-pharmaceutical interventions that were carried out in many other countries. We evaluated the effectiveness of the mandatory quarantine and provide suggestions for interventions against possible future influenza pandemics. We selected one city, Beijing, as the analysis target. We reviewed the epidemiologic dynamics of the 2009 H1N1 pandemic and the implementation of quarantine measures in Beijing. The infectious population was simulated under two scenarios (quarantined and not quarantined) using a deterministic Susceptible-Exposed-Infectious-Recovered (SEIR) model. The basic reproduction number R0 was adjusted to match the epidemic wave in Beijing. We found that mandatory quarantine served to postpone the spread of the 2009 H1N1 pandemic in Beijing by one and a half months. If mandatory quarantine was not enforced in Beijing, the infectious population could have reached 1,553 by 21 October, i.e., 5.6 times higher than the observed number. When the cost of quarantine is taken into account, mandatory quarantine was not an economically effective intervention approach against the 2009 H1N1 pandemic. We suggest adopting mitigation methods for an influenza pandemic with low mortality and morbidity.

Influence of safety warnings on ESA prescribing among dialysis patients using an interrupted time series

Background

In March, 2007, a black box warning was issued by the Food and Drug Administration (FDA) to use the lowest possible erythropoiesis-stimulating agents (ESA) doses for treatment of anemia associated with renal disease. The goal is to determine if a change in ESA use was observed following the warning among US dialysis patients.

Methods

ESA therapy was examined from September 2004 through August 2009 (thirty months before and after the FDA black box warning) among adult Medicare hemodialysis patients. An interrupted time series model assessed the impact of the warnings.

Results

The FDA black box warning did not appear to influence ESA prescribing among the overall dialysis population. However, significant declines in ESA therapy after the FDA warnings were observed for selected populations. Patients with a hematocrit ≥36% had a declining month-to-month trend before (−164 units/week, p = <0.0001) and after the warnings (−80 units/week, p = .001), and a large drop in ESA level immediately after the black box (−4,744 units/week, p = <.0001). Not-for-profit facilities had a declining month-to-month trend before the warnings (−90 units/week, p = .009) and a large drop in ESA dose immediately afterwards (−2,487 units/week, p = 0.015). In contrast, for-profit facilities did not have a significant change in ESA prescribing.

Conclusions

ESA therapy had been both profitable for providers and controversial regarding benefits for nearly two decades. The extent to which a FDA black box warning highlighting important safety concerns influenced use of ESA therapy among nephrologists and dialysis providers was unknown. Our study found no evidence of changes in ESA prescribing for the overall dialysis population resulting from a FDA black box warning.

Drug and sexual HIV risk behaviours related to knowledge of HIV serostatus among injection drug users in Houston, Texas

This study examines the association between drug and sexual HIV risk behaviours and knowledge of HIV serostatus among a sample of injection drug users, recruited into the 2009 National HIV Behavioral Surveillance project. We calculated prevalence ratios and associated 95% confidence intervals of reporting a given risk behaviour comparing injection drug users unaware of their serostatus and HIV-negative to HIV-positive injection drug users. Of 523 participants, 21% were unaware of their HIV serostatus. The three groups were not different from each other in terms of drug-use behaviours; however, injection drug users unaware of their HIV serostatus were 33% more likely to report having more than three sexual partners in the past 12 months and 45% more likely to report having unprotected sex compared to HIV-positive injection drug users. We observed markedly higher prevalence of sexual risk behaviours among injection drug users unaware of their serostatus, but drug-use risk behaviours were similar across the groups.

A new method for quantitative real-time polymerase chain reaction data analysis

Quantitative real-time polymerase chain reaction (qPCR) is a sensitive gene quantification method that has been extensively used in biological and biomedical fields. The currently used methods for PCR data analysis, including the threshold cycle method and linear and nonlinear model-fitting methods, all require subtracting background fluorescence. However, the removal of background fluorescence can hardly be accurate and therefore can distort results. We propose a new method, the taking-difference linear regression method, to overcome this limitation. Briefly, for each two consecutive PCR cycles, we subtract the fluorescence in the former cycle from that in the latter cycle, transforming the n cycle raw data into n-1 cycle data. Then, linear regression is applied to the natural logarithm of the transformed data. Finally, PCR amplification efficiencies and the initial DNA molecular numbers are calculated for each reaction. This taking-difference method avoids the error in subtracting an unknown background, and thus it is more accurate and reliable. This method is easy to perform, and this strategy can be extended to all current methods for PCR data analysis.

Optimal allocation of sample sizes to multicenter clinical trials

In this article, we discuss an approach for optimal sample size allocation in designing multicenter clinical trials. The method we studied was adapted from a stratified sampling survey design. The sample size allocated to centers is a function of the center's treatment cost, the standard deviation of the endpoint, and the availability of patients. We illustrate our approach using two hypothetical scenarios derived from our experiences in designing and conducting multicenter clinical trials. Simulation results are also presented.

Thinking big by thinking small: application of microfluidic technology to improve ART

In Vitro Fertilization (IVF) laboratories often carry a penchant to resist change while in the pursuit of maintaining consistency in laboratory conditions. However, implementation of new technology is often critical to expand scientific discoveries and to improve upon prior successes to advance the field. Microfluidic platforms represent a technology that has the potential to revolutionize the fundamental processes of IVF. While the focus of microfluidic application in IVF has centered on embryo culture, the innovative platforms carry tremendous potential to improve other procedural steps and represents a possible paradigm shift in how we handle gametes and embryos. The following review will highlight application of various microfluidic platforms in IVF for use in maturation, manipulation, culture, cryopreservation and non-invasive quality assessment; pointing out new insights gained into functions of sperm, oocytes and embryos. Platform design and function will also be discussed, focusing on limitations, advancements and future refinements that can further aid in their clinical implementation.

Progression of myopia and high myopia in the Early Treatment for Retinopathy of Prematurity study: findings at 4 to 6 years of age

PURPOSE

To report the prevalence of myopia and high myopia in children <6 years of age born preterm with birth weights <1251 g who developed high-risk prethreshold retinopathy of prematurity and who participated in the Early Treatment for Retinopathy of Prematurity trial.

METHODS

Surviving children from the cohort of 401 participants who had developed high-risk prethreshold ROP in one or both eyes underwent cycloplegic retinoscopy at 6 and 9 months corrected age and yearly between 2 and 6 years postnatal age. Eyes were randomized to receive treatment at high-risk prethreshold ROP or conventional management with treatment only if threshold ROP developed. Myopia (spherical equivalent ≥0.25 D) or high myopia (≥5.00 D) in eyes at 4-, 5-, and 6-year examinations was reported.

RESULTS

At ages 4, 5, and 6 years, there was no difference in the percentage of eyes with myopia (range, 64.8%-69.9%) and eyes with high myopia (range, 35.3%-39.4%) between earlier treated and conventionally managed eyes.

CONCLUSIONS

Approximately two-thirds of eyes with high-risk prethreshold ROP during the neonatal period are likely to be myopic into the preschool and early school years. In addition, the increase in the proportion of eyes with high myopia that had been observed in both earlier-treated and conventionally managed eyes between ages 6 months and 3 years does not continue between ages 3 and 6 years.

Randomized double-blind controlled trial of bovine lactoferrin for prevention of diarrhea in children

OBJECTIVE

To determine the effect of bovine lactoferrin (bLF) on prevention of diarrhea in children.

STUDY DESIGN

We conducted a community-based randomized double-blind placebo controlled trial comparing supplementation with bLF vs placebo. Previously weaned children were enrolled at 12-18 months and followed for 6 months with daily home visits for data collection and supplement administration. Anthropometric measures were done monthly.

RESULTS

Five hundred fifty-five children were randomized: 277 to bLF and 278 to placebo; 65 dropped out; 147 894 doses were administered (92% compliance). Overall there were 91 446 child-days of observation and 1235 diarrhea episodes lasting 6219 days. The main pathogens isolated during diarrheal episodes were norovirus (35.0%), enteropathogenic E coli (11.4%), Campylobacter (10.6%), enteroaggregative E coli (8.4%), enterotoxigenic E coli (6.9%), and Shigella (6.6%). The diarrhea incidence was not different between groups: 5.4 vs 5.2 episodes/child/year for bLF and placebo, respectively (P = .375). However, the diarrhea longitudinal prevalence was lower in the bLF group vs placebo (6.6% vs 7.0%, P = .017), as well as the median duration of episodes (4.8 vs 5.3 days, P = .046), proportion of episodes with moderate or severe dehydration (1.0% vs 2.6%, P = .045), and liquid stools load (95.0 vs 98.6) liquid stools/child/year, P < .001). There were no adverse events related to the intervention.

CONCLUSIONS

Although there was no decrease in diarrhea incidence, longitudinal prevalence and severity were decreased with LF.

Effect of the use and timing of bone marrow mononuclear cell delivery on left ventricular function after acute myocardial infarction: the TIME randomized trial

CONTEXT

While the delivery of cell therapy after ST-segment elevation myocardial infarction (STEMI) has been evaluated in previous clinical trials, the influence of the timing of cell delivery on the effect on left ventricular function has not been analyzed.

OBJECTIVES

To determine the effect of intracoronary autologous bone marrow mononuclear cell (BMC) delivery after STEMI on recovery of global and regional left ventricular function and whether timing of BMC delivery (3 days vs 7 days after reperfusion) influences this effect.

DESIGN, SETTING, AND PATIENTS

A randomized, 2 × 2 factorial, double-blind, placebo-controlled trial, Timing In Myocardial infarction Evaluation (TIME) enrolled 120 patients with left ventricular dysfunction (left ventricular ejection fraction [LVEF] ≤ 45%) after successful primary percutaneous coronary intervention (PCI) of anterior STEMI between July 17, 2008, and November 15, 2011, as part of the Cardiovascular Cell Therapy Research Network sponsored by the National Heart, Lung, and Blood Institute.

INTERVENTIONS

Intracoronary infusion of 150 × 106 BMCs or placebo (randomized 2:1) within 12 hours of aspiration and cell processing administered at day 3 or day 7 (randomized 1:1) after treatment with PCI.

MAIN OUTCOME MEASURES

The primary end points were change in global (LVEF) and regional (wall motion) left ventricular function in infarct and border zones at 6 months measured by cardiac magnetic resonance imaging and change in left ventricular function as affected by timing of treatment on day 3 vs day 7. The secondary end points included major adverse cardiovascular events as well as changes in left ventricular volumes and infarct size.

RESULTS

The mean (SD) patient age was 56.9 (10.9) years and 87.5% of participants were male. At 6 months, there was no significant increase in LVEF for the BMC group (45.2% [95% CI, 42.8% to 47.6%] to 48.3% [95% CI, 45.3% to 51.3%) vs the placebo group (44.5% [95% CI, 41.0% to 48.0%] to 47.8% [95% CI, 43.4% to 52.2%]) (P = .96). There was no significant treatment effect on regional left ventricular function observed in either infarct or border zones. There were no significant differences in change in global left ventricular function for patients treated at day 3 (−0.9% [95% CI, −6.6% to 4.9%], P = .76) or day 7 (1.1% [95% CI, −4.7% to 6.9%], P = .70). The timing of treatment had no significant effect on regional left ventricular function recovery. Major adverse events were rare among all treatment groups.

CONCLUSION

Among patients with STEMI treated with primary PCI, the administration of intracoronary BMCs at either 3 days or 7 days after the event had no significant effect on recovery of global or regional left ventricular function compared with placebo.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00684021.

Clustered drug and sexual HIV risk among a sample of middle-aged injection drug users, Houston, Texas

Recent studies have reported a clustered pattern of high-risk drug using and sexual behaviors among younger injection drug users (IDUs), however, no studies have looked at this clustering pattern in relatively older IDUs. This analysis examines the interplay and overlap of drug and sexual HIV risk among a sample of middle-aged, long-term IDUs in Houston, Texas. Our study includes 452 eligible IDUs, recruited into the 2009 National HIV Behavioral Surveillance project. Four separate multiple logistic regression models were built to examine the odds of reporting a given risk behavior. We constructed the most parsimonious multiple logistic regression model using a manual backward stepwise process. Participants were mostly male, older (mean age: 49.5±6.63), and nonHispanic Black. Prevalence of receptive needle sharing as well as having multiple sex partners and having unprotected sex with a partner in exchange for money, drugs, or other things at last sex were high. Unsafe injecting practices were associated with high-risk sexual behaviors. IDUs, who used a needle after someone else had injected with it had higher odds of having more than three sex partners (odds ratio (OR) = 2.10, 95% confidence interval (CI): 1.40-3.12) in last year and who shared drug preparation equipment had higher odds of having unprotected sex with an exchange partner (OR = 3.89, 95% CI: 1.66-9.09) at last sex. Additionally, homelessness was associated with unsafe injecting practices but not with high-risk sexual behaviors. Our results show that a majority of the sample IDUs are practicing sexual as well as drug-using HIV risk behaviors. The observed clustering pattern of drug and sexual risk behavior among this middle-aged population is alarming and deserve attention of HIV policy-makers and planners.

Imaging of highly malignant osteosarcoma with iodine-123-vascular endothelial growth factor

OBJECTIVE

Vascular endothelial growth factor (VEGF) is an important angiogenic factor, and its receptors have been shown to be overexpressed in various human carcinomas. In this study, we investigated the role of scanning with iodine-123 ((123)I)-labelled VEGF(165) in patients with highly malignant osteosarcoma.

METHODS

Two patients (a 15-year-old female and a 14-year-old male) with osteosarcoma were injected with 140 MBq [<130 pmol (<5 µg) VEGF(165) per patient] of (123)I-VEGF(165). Dynamic acquisition was initiated immediately after administration and carried out until 30 min after injection. Whole-body images were done in anterior and posterior views at various time points. All patients underwent single-photon emission tomography imaging.

RESULTS

(123)I-VEGF(165) scans were positive in these patients. Sequential images clearly showed increased (123)I-VEGF(165) activity in osteosarcoma lesions. The tumour lesions were still visualized in whole-body images and single-photon emission tomography examinations 2 h after injection. Intravenous injection of (123)I-VEGF(165) did not cause any side effects.

CONCLUSION

Our results suggest that (123)I-VEGF(165) receptor scintigraphy may be useful for the visualization of highly malignant osteosarcoma and/or metastasis and the angiogenic activity of the tumour.

miR-21, miR-17 and miR-19a induced by phosphatase of regenerating liver-3 promote the proliferation and metastasis of colon cancer

Background:

Phosphatase of regenerating liver-3 (PRL-3) is an oncogene known to promote tumour metastasis, especially in colorectal cancer (CRC). Here, we demonstrate that the miR-21, miR-17 and miR-19a expressions induced by PRL-3 are involved in the proliferation and metastasis of colon cancer.

Methods:

Microarray analysis and quantitative reverse-transcription polymerase chain reactions (qRT–PCR) were used to investigate the changes in miRNA expression due to the overexpression of PRL-3. Transwell chamber invasion assays, CCK-8 proliferation assays and RNA interference assays were used to explore the effects of PRL-3 on miR-21, miR-17 and miR-19a expression in colon cancer cells. Immunohistochemistry and qRT–PCR were performed in colon cancer tissues to evaluate the expression of PRL-3, signal transducer and activator of transcription 3 (STAT3), miR-21, miR-17 and miR-19a.

Results:

Our study demonstrated that the overexpression of PRL-3 in colon cancer cells induced the expression of miR-21, miR-17 and miR-19a by activating STAT3. Subsequently, these microRNAs contributed to the increased proliferation and invasiveness of the colon cancer cells. Positive correlations between PRL-3 and these microRNAs were also observed in matched primary colon cancer tissues and metastatic lesions.

Conclusion:

miR-21, miR-17 and miR-19a induced by PRL-3 contribute to the proliferation and invasion of colon cancer.

Effect of transendocardial delivery of autologous bone marrow mononuclear cells on functional capacity, left ventricular function, and perfusion in chronic heart failure: the FOCUS-CCTRN trial

CONTEXT

Previous studies using autologous bone marrow mononuclear cells (BMCs) in patients with ischemic cardiomyopathy have demonstrated safety and suggested efficacy.

OBJECTIVE

To determine if administration of BMCs through transendocardial injections improves myocardial perfusion, reduces left ventricular end-systolic volume (LVESV), or enhances maximal oxygen consumption in patients with coronary artery disease or LV dysfunction, and limiting heart failure or angina.

DESIGN, SETTING, AND PATIENTS

A phase 2 randomized double-blind, placebo-controlled trial of symptomatic patients (New York Heart Association classification II-III or Canadian Cardiovascular Society classification II-IV) with a left ventricular ejection fraction of 45% or less, a perfusion defect by single-photon emission tomography (SPECT), and coronary artery disease not amenable to revascularization who were receiving maximal medical therapy at 5 National Heart, Lung, and Blood Institute-sponsored Cardiovascular Cell Therapy Research Network (CCTRN) sites between April 29, 2009, and April 18, 2011.

INTERVENTION

Bone marrow aspiration (isolation of BMCs using a standardized automated system performed locally) and transendocardial injection of 100 million BMCs or placebo (ratio of 2 for BMC group to 1 for placebo group).

MAIN OUTCOME MEASURES

Co-primary end points assessed at 6 months: changes in LVESV assessed by echocardiography, maximal oxygen consumption, and reversibility on SPECT. Phenotypic and functional analyses of the cell product were performed by the CCTRN biorepository core laboratory.

RESULTS

Of 153 patients who provided consent, a total of 92 (82 men; average age: 63 years) were randomized (n = 61 in BMC group and n = 31 in placebo group). Changes in LVESV index (-0.9 mL/m(2) [95% CI, -6.1 to 4.3]; P = .73), maximal oxygen consumption (1.0 [95% CI, -0.42 to 2.34]; P = .17), and reversible defect (-1.2 [95% CI, -12.50 to 10.12]; P = .84) were not statistically significant. There were no differences found in any of the secondary outcomes, including percent myocardial defect, total defect size, fixed defect size, regional wall motion, and clinical improvement.

CONCLUSION

Among patients with chronic ischemic heart failure, transendocardial injection of autologous BMCs compared with placebo did not improve LVESV, maximal oxygen consumption, or reversibility on SPECT.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00824005.

Astigmatism progression in the early treatment for retinopathy of prematurity study to 6 years of age

PURPOSE

To examine the prevalence of astigmatism (≥ 1.00 diopter [D]) and high astigmatism (≥ 2.00 D) from 6 months after term due date to 6 years of age in preterm children with birth weight of less than 1251 g in whom high-risk prethreshold retinopathy of prematurity (ROP) developed and who participated in the Early Treatment for ROP study.

DESIGN

Observational cohort study.

PARTICIPANTS

Four hundred one infants in whom high-risk prethreshold ROP developed in 1 or both eyes and were randomized to early treatment (ET) versus conventional management (CM). Refractive error was measured by cycloplegic retinoscopy. Eyes were excluded if they underwent additional retinal, glaucoma, or cataract surgery.

INTERVENTION

Eyes were randomized to receive laser photocoagulation at high-risk prethreshold ROP or to receive treatment only if threshold ROP developed.

MAIN OUTCOME MEASURES

Astigmatism and high astigmatism at each study visit.

RESULTS

For both ET and CM eyes, there was a consistent increase in prevalence of astigmatism over time, increasing from 42% at 4 years to 52% by 6 years for the group of ET eyes and from 47% to 54%, respectively, in the CM eyes. There was no statistically significant difference between the slopes (rate of change per month) of the ET and CM eyes for both astigmatism and high astigmatism (P = 0.75).

CONCLUSIONS

By 6 years of age, astigmatism of 1.00 D or more developed in more than 50% of eyes with high-risk prethreshold ROP, and nearly 25% of such eyes had high astigmatism (≥ 2.00 D). Presence of astigmatism was not influenced by timing of treatment, zone of acute-phase ROP, or presence of plus disease. However, there was a trend toward higher prevalence of astigmatism and high astigmatism in eyes with ROP residua. Most astigmatism was with-the-rule (75°-105°). More eyes with type 2 than type 1 ROP had astigmatism by 6 years. These findings reinforce the need for follow-up eye examinations through early grade school years in infants with high-risk prethreshold ROP.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Validation of the gravity model in predicting the global spread of influenza

The gravity model is often used in predicting the spread of influenza. We use the data of influenza A (H1N1) to check the model's performance and validation, in order to determine the scope of its application. In this article, we proposed to model the pattern of global spread of the virus via a few important socio-economic indicators. We applied the epidemic gravity model for modelling the virus spread globally through the estimation of parameters of a generalized linear model. We compiled the daily confirmed cases of influenza A (H1N1) in each country as reported to the WHO and each state in the USA, and established the model to describe the relationship between the confirmed cases and socio-economic factors such as population size, per capita gross domestic production (GDP), and the distance between the countries/states and the country where the first confirmed case was reported (i.e., Mexico). The covariates we selected for the model were all statistically significantly associated with the global spread of influenza A (H1N1). However, within the USA, the distance and GDP were not significantly associated with the number of confirmed cases. The combination of the gravity model and generalized linear model provided a quick assessment of pandemic spread globally. The gravity model is valid if the spread period is long enough for estimating the model parameters. Meanwhile, the distance between donor and recipient communities has a good gradient. Besides, the spread should be at the early stage if a single source is taking into account.

Fractional Brownian motion and long term clinical trial recruitment

Prediction of recruitment in clinical trials has been a challenging task. Many methods have been studied, including models based on Poisson process and its large sample approximation by Brownian motion (BM), however, when the independent incremental structure is violated for BM model, we could use fractional Brownian motion to model and approximate the underlying Poisson processes with random rates. In this paper, fractional Brownian motion (FBM) is considered for such conditions and compared to BM model with illustrated examples from different trials and simulations.

Kriged and modeled ambient air levels of benzene in an urban environment: an exposure assessment study

BACKGROUND

There is increasing concern regarding the potential adverse health effects of air pollution, particularly hazardous air pollutants (HAPs). However, quantifying exposure to these pollutants is problematic.

OBJECTIVE

Our goal was to explore the utility of kriging, a spatial interpolation method, for exposure assessment in epidemiologic studies of HAPs. We used benzene as an example and compared census tract-level kriged predictions to estimates obtained from the 1999 U.S. EPA National Air Toxics Assessment (NATA), Assessment System for Population Exposure Nationwide (ASPEN) model.

METHODS

Kriged predictions were generated for 649 census tracts in Harris County, Texas using estimates of annual benzene air concentrations from 17 monitoring sites operating in Harris and surrounding counties from 1998 to 2000. Year 1999 ASPEN modeled estimates were also obtained for each census tract. Spearman rank correlation analyses were performed on the modeled and kriged benzene levels. Weighted kappa statistics were computed to assess agreement between discretized kriged and modeled estimates of ambient air levels of benzene.

RESULTS

There was modest correlation between the predicted and modeled values across census tracts. Overall, 56.2%, 40.7%, 31.5% and 28.2% of census tracts were classified as having 'low', 'medium-low', 'medium-high' and 'high' ambient air levels of benzene, respectively, comparing predicted and modeled benzene levels. The weighted kappa statistic was 0.26 (95% confidence interval (CI) = 0.20, 0.31), indicating poor agreement between the two methods.

CONCLUSIONS

There was a lack of concordance between predicted and modeled ambient air levels of benzene. Applying methods of spatial interpolation for assessing exposure to ambient air pollutants in health effect studies is hindered by the placement and number of existing stationary monitors collecting HAP data. Routine monitoring needs to be expanded if we are to use these data to better assess environmental health risks in the future.

Disease modeling by gene targeting using microRNAs

Zebrafish have proved to be a popular species for the modeling of human disease. In this context, there is a need to move beyond chemical-based mutagenesis and develop tools that target genes that are orthologous to those that are implicated in human heritable diseases. Targeting can take the form of creating mutations that are nonsense or mis-sense, or to mimic haploinsufficiency through the regulated expression of RNA effector molecules. In terms of the latter, we describe here the development and investigation of microRNA (miRNA)-based directed gene silencing methods in zebrafish. Unlike small interfering RNAs (siRNAs), miRNA-based methods offer temporal and spatial regulation of gene silencing. Proof-of-concept experiments demonstrate the efficacy of the method in zebrafish embryos, which provide the foundation for developing disease models using miRNA-based gene-targeting.