School Injury Among Ottawa-Area Children: A Population-Based Study

BACKGROUND:  Injuries are the leading cause of death among Canadian children and are responsible for a substantial proportion of hospitalizations and emergency department visits. This investigation sought to identify the factors associated with the likelihood of sustaining an injury at school among Ottawa-area children.
METHODS:  Children presenting to Ottawa-area hospitals and urgent care clinics from January to December 2002 (n = 24,074) were included for analysis. The frequency of school injuries by sex, age group, type of injury, and hospitalization was analyzed. Multivariate logistic regression was used to assess the factors associated with sustaining an injury at school. The school activities most associated with injury and the most frequent types of school injuries were assessed.
RESULTS:  A total of 4287 Ottawa-area children were injured at school in 2002, representing 18% of all injuries. Children aged 5-9 years and 10-14 years were more likely to have school injuries than older children (aged 15-19 years) (OR = 3.07, 95% CI = 2.77-3.40 and OR = 3.10, 95% CI = 2.83-3.37, respectively). The most frequently encountered school injuries were fractures (n = 1132) and musculoskeletal injury (n = 907). The most frequent mechanisms of school injuries were "playing" (n = 1004) and "informal sports" (n = 1503).
CONCLUSIONS:  Many children get hurt at school, particularly during informal recreation activities. Environmental modification and increased supervision are strategies that may reduce school injuries.     

Synergistic interaction between nicotine and social rewards in adolescent male rats

Rationale  Smoking typically begins during adolescence and is largely reinforced by social cues. During adolescence in rats, sensitivity to both social cues and drugs of abuse is enhanced. Objectives  We have previously demonstrated in adolescent male rats that a low dose of cocaine interacts with social reward to produce an enhanced conditioned place preference (CPP) relative to either reward given alone. The present study further examined the nature of drug–social reward interactions using nicotine. Methods  Dose–effect functions for nicotine-CPP were established using two different routes of administration (vehicle, 0.1, 0.3, and 0.6 mg/kg, SC and vehicle, 0.01, 0.03, and 0.06 mg/kg, IV). The effects of nicotine on social reward-CPP and social play behavior were next examined using parameters presumed to be sub-threshold for establishing social reward- and nicotine-CPP. Results  Dose-dependent nicotine-CPP was observed using both routes of administration. Two pairings of the initially non-preferred side of the apparatus with either SC nicotine or another adolescent rat failed to produce CPP when examined alone, but together produced a robust CPP despite nicotine reducing social play. This interaction effect was not observed with the IV nicotine. A final experiment demonstrated that the enhancement of CPP with the combination of rewards was not due to additive effects of weak, sub-threshold conditioning. Conclusions  These findings suggest that nicotine and social rewards interact synergistically in adolescent rats resulting in a greater, perhaps qualitatively different, reward than either reward given alone. Understanding drug–social reward interactions may provide new directions for development of preventions and interventions of adolescent smoking. Funding sources: This work was supported by grants R01DA11064, R21DA023123, and F31DA023746 from the National Institute on Drug Abuse (NIDA). The content is solely the responsibility of the authors and does not necessarily represent the official view of NIDA or the National Institutes of Health.     

Combined treatment with Denbinobin and Fas ligand has a synergistic cytotoxic effect in human pancreatic adenocarcinoma BxPC-3 cells

Background and purpose:

Human pancreatic carcinoma is a highly malignant cancer. Previous studies have shown that the decoy receptor 3 (DcR3) for Fas ligand (FasL) plays significant roles in tumour progression and immune suppression. In the present study, we evaluated the anti-cancer activity of a natural compound, denbinobin (5-hydroxy-3,7-dimethoxy-1,4-phenanthraquinone), through decreasing DcR3 levels in human pancreatic adenocarcinoma cell lines.

Experimental approach:

We used immunoprecipitation and ELISA assays to examine DcR3 levels, and used FACS to determine the percentage of cells with a sub-G1 DNA content.

Key results:

AsPC-1 and BxPC-3 human pancreatic cancer cells express high levels of DcR3. Denbinobin concentration-dependently decreased DcR3 levels in BxPC-3 cells. MTT and flow cytometry assays indicated that BxPC-3 was FasL-resistant because high concentrations (100 ng·mL⁻¹) of soluble FasL did not inhibit cell growth. However, combinations of denbinobin (3 µmol·L⁻¹) with lower concentrations of soluble FasL (10, 30 and 50 ng·mL⁻¹) or membrane-bound FasL, were synergistic on cell growth inhibition and apoptosis. Exogenous excess DcR3 reversed this synergistic effect. We observed no significant increase in the levels of surface Fas, cleaved forms of caspase-8, -3, -9, Bax, Bid, Bcl-xL, cytochrome c or mitochondrial membrane potentials following denbinobin treatment. However, denbinobin treatment increased the levels of apoptosis-inducing factor.

Conclusions and implications:

Denbinobin and FasL trigger a synergistic cytotoxic effect in human pancreatic adenocarcinoma cells. Denbinobin mediated a decrease in levels of DcR3, which played a major role in this synergistic effect, and also increased caspase-independent apoptosis, via apoptosis-inducing factor.     

Phase I Safety, Tolerability, and Pharmacokinetic Study of Recombinant Human Mannan-Binding Lectin

Mannan-binding lectin (MBL), a human plasma protein, plays an important role in the innate immune defence. MBL recognizes microorganisms through surface carbohydrate structures. Due to genetic polymorphisms, MBL plasma concentrations range from 5 to 10,000 ng/mL. Approximately 30% of the human population have low levels of MBL (below 500 ng/mL). MBL deficiency is associated with increased susceptibility to infections in immunosuppressed individuals, e.g., during chemotherapeutically induced neutropenia. Replacement therapy with MBL may be beneficial in this patient group, and recombinant human MBL (rhMBL) is in development as a novel therapeutic approach. To assess the safety, tolerability, and pharmacokinetics of rhMBL, a placebo-controlled double-blinded study was performed in MBL-deficient healthy male subjects. rhMBL was administered as both single intravenous (i.v.) infusions (0.01, 0.05, 0.1, and 0.5 mg/kg) and repeated i.v. infusions (0.1 or 0.3 mg/kg given at 3-day intervals). There were no difference in incidence and type of adverse events reported in the study between the groups of subjects receiving rhMBL and the placebo group. All adverse events reported as drug-related were mild and no serious adverse events were recorded. There were no clinically significant changes in laboratory evaluations, ECG or vital signs, and no anti-MBL antibodies were detected following rhMBL administration. After single i.v. doses of rhMBL the maximal plasma levels increased in a dose-dependent manner reaching a geometric mean of 9710 ng/mL±10.5% in the highest dose group (0.5 mg/kg), with an elimination half-life of approximately 30 h. No rhMBL accumulation in plasma was observed following repeat dosing. Administration of rhMBL restored the ability to activate the MBL pathway of the complement system without non-specific activation of the complement cascade.In conclusion, no safety or tolerability concern was raised following rhMBL administration no signs of immunogenicity detected, and an rhMBL plasma level judged sufficient to achieve therapeutic benefit (>1000 ng/mL) can be achieved.     

Effects of nicotine on visuo-spatial selective attention as indexed by event-related potentials

Nicotine has been shown to specifically reduce reaction times to invalidly cued targets in spatial cueing paradigms. In two experiments, we used event-related potentials to test whether the facilitative effect of nicotine upon the detection of invalidly cued targets is due to a modulation of perceptual processing, as indexed by early attention-related event-related potential components. Furthermore, we assessed whether the effect of nicotine on such unattended stimuli depends upon the use of exogenous or endogenous cues. In both experiments, the electroencephalogram was recorded while non-smokers completed discrimination tasks in Posner-type paradigms after chewing a nicotine polacrilex gum (Nicorette 2 mg) in one session and a placebo gum in another session. Nicotine reduced reaction times to invalidly cued targets when cueing was endogenous. In contrast, no differential effect of nicotine on reaction times was observed when exogenous cues were used. Electrophysiologically, we found a similar attentional modulation of the P1 and N1 components under placebo and nicotine but a differential modulation of later event-related potential components at a frontocentral site. The lack of a drug-dependent modulation of P1 and N1 in the presence of a behavioral effect suggests that the effect of nicotine in endogenous visuo-spatial cueing tasks is not due to an alteration of perceptual processes. Rather, the differential modulation of frontocentral event-related potentials suggests that nicotine acts at later stages of target processing.     

High Seroprevalence of Neutralizing Capacity against Human Metapneumovirus in All Age Groups Studied in Bonn,Germany

Human metapneumovirus (hMPV) infections occur frequently despite high rates of perpetual seroprevalence for all age groups. Analyses of ∼2,000 archived, randomly selected serum samples demonstrated that neutralizing capacities remain high, with a minor decrease for individuals over 69 years of age, leading to the hypothesis that reinfections occur because humoral immune responses play minor roles in the clearance of hMPV infections.The human metapneumovirus (hMPV) was first isolated in 2001 from children hospitalized with acute respiratory infections (ARIs) (18). hMPV belongs to the Paramyxoviridae family and is one of the major causes of upper and lower ARIs. By the age of five, nearly every child has been infected with hMPV (18). Since hMPV was first described, it has been reported from all over the world, with prevalences of infection ranging from 3.9 to 43% (12, 13). hMPV seems to have a seasonal distribution, like respiratory syncytial virus (RSV) and influenza virus. Infections occur mainly during the winter months (2, 14, 20). Up to now, two genotypes (A and B), each with two subgroups (A1 and A2 and B1 and B2, respectively), have been identified (11), but it is not known if the two genotypes represent two serotypes and if they lead to variations in the severity of clinical symptoms (19). Symptoms associated with a hMPV infection range from mild infections of the upper respiratory tract to severe lower respiratory tract infections like bronchiolitis and pneumonia. Wheezing, coughing, fever, and dyspnea are frequently observed (2, 9, 18). More-severe hMPV infections primarily affect infants and children, while otherwise healthy adults suffer solely from influenza-like illnesses. However, immunocompromised adults show exacerbated courses of asthma and chronic obstructive pulmonary diseases (8, 10, 21). For the elderly, only a few studies have been released, but it has been stated that hMPV infections often lead to hospitalizations and are associated with high mortality in the elderly (3-5). The aim of the present study was to analyze patient sera for the ability to neutralize hMPV and to investigate whether there are any differences among the different age groups.Serum samples from a total of 2,000 patient were randomly collected from the archives of the Institute of Virology of the University Hospital Bonn (which includes a large trauma center for the geographic area and a large obstetrics unit, resulting in many patients in the 20- to 50-year-old age range) and screened for neutralizing capacity, using the XTT-based neutralization test described previously (17).In brief, 5 × 10⁴ genome equivalents (geq) of hMPV cells in 50 μl of Dulbecco''s modified Eagle''s medium (DMEM) or 50 μl of DMEM without the virus was applied to the wells of a 96-well plate (Nunc, Karlsruhe, Germany). Afterward, 25 μl of sera was added to each well. Finally, 5 × 10⁴ HepG2 cells in 125 μl of medium were added to each well and preincubated for 30 min. The DMEM formulation was clear DMEM with 4.5 g liter⁻¹ glucose, 3% (vol/vol) fetal calf serum (FCS), 1% (vol/vol) 100× penicillin-streptomycin mixture (10,000 U/ml of penicillin and 10 mg/ml of streptomycin), 1% nonessential amino acids, 1% l-glutamine, and 1% sodium pyruvate (all from PAA, Austria).The cells were incubated for 7 days at 33.4°C and 5.0% CO₂. The confluence and morphology of the cells were controlled daily under an inverse microscope. At day 7, 150 μl of supernatant was removed from each well and discarded. The prewarmed (37°C) XTT test kit solutions were mixed by pipetting the coupling reagent into the yellow tetrazolium salt. Fifty microliters of the solution was added to each well, and the plate was incubated for 1 h at 33.4°C and 5.0% CO₂ before extinction was measured at 456 nm, with 650 nm as the reference measurement, in a 96-well plate reader. For additional verification of the results, cells were counterstained with crystal violet. To investigate the neutralizing capacity of the tested patients'' sera, the results of the XTT test of the cells infected with hMPV and treated with patients'' sera were compared to a reference dilution series and the results for the corresponding noninfected cells. The optical density (OD) value quotients for the infected and corresponding noninfected cells were calculated. A value less than 1 indicated that the sera had a neutralizing effect on the virus.For calibration purposes and as a quality control for each test, serial virus dilutions were run in parallel on each plate to ensure that the virus concentration in the inoculum was reciprocal to cell viability, as previously shown (17). As expected, the absorption rate increased with decreasing virus concentrations (Fig. ​(Fig.1a).1a). A reduction in half of the virus concentration was comparable to an increase in OD of approximately 0.04.Open in a separate windowFIG. 1.(a) Dilution series were performed for quality control. Cells were infected with decreasing amounts of hMPV and incubated for 7 days before an XTT test was performed. Data are given as means ± standard errors of the means (SEMs). (b) Evaluation of neutralizing capacity, using an XTT-based neutralization assay for children. Sera were grouped by age in order to elucidate putative breast-feeding-derived neutralization capacity. Data are given as means ± SEMs. (c) Sera from a total of 1,953 patients were screened for neutralizing capacity, using an XTT-based neutralization assay. Data are given as means ± SEMs. AU, arbitrary units; *, results significantly different from those for 0- to 9-year-old group (P ≤ 0.05).In total, 2,000 serum samples were initially included in the study. The sera were collected routinely as retained samples and archived for up to 10 years. Collection and archiving of the sera were in concordance with a vote by the local ethical committee. The serum samples were randomly selected and represent a cross section of the patient cohort admitted to our hospital during the last 10 years and reflect the demographic distribution of patients admitted to our hospital.Of the 2,000 serum samples tested, 49 were toxic per se for the cultured cells and could not be used for further evaluations. Of the remaining 1,951 serum samples, 1,879 (96.21%) showed neutralizing effects (Table ​(Table1).1). The majority of the negative serum samples were from cohorts of patients who were 0 to ≤2, 60 to 69, and 70 to 79 years old. The sera of the group of patients who were >2 to 9 years old showed the least virus neutralization capacity. Neutralizing capacity increased in patients 10 to 29 years old before it reached a plateau. On average, the neutralizing effect was ∼10% higher for patients 29 to 69 years old than for patients 0 to ≤2 years old and ∼20% higher than for patients >2 to 9 years old. Starting with patients 70 to 79 years old, a trend of decreasing neutralizing ability of the sera was seen (Fig. ​(Fig.1b).1b). Admittedly, the standard deviation for the older-patient groups is very high due to the small group size, but the results indicate that it may be worth conducting more-specific surveys on the elderly concerning neutralization potency.

TABLE 1.

Age distribution of patients and number of samples per group that tested positive or negative for neutralizing ability^a

Shared decision-making in breast cancer: discrepancy between the treatment efficacy required by patients and by physicians

Several factors can influence individual perceptions of the expected benefit of recommended adjuvant treatment for breast cancer. This study investigated differences between patients and physicians with regard to the required efficacy of treatment and the factors influencing patients' and physicians' willingness to accept different therapeutic options. A total of 9,000 questionnaires were distributed to patients with breast cancer, and 6,938 questionnaires were distributed to physicians treating breast cancer patients. The patients were asked for personal information and about their medical history and experiences during treatment. The physicians were asked about personal information and their specialty and work environment. The treatment efficacy required by the two groups was assessed using six virtual cases of breast cancer and the treatment regimens proposed, with specific benefits and side effects. A total of 2,155 patients and 527 physicians responded to the questionnaire (return rates of 23.9 and 7.6?%). Significantly different ratings between patients and physicians with regard to the expected benefit of certain treatment options were observed. The differences were noted not only for chemotherapy but also for antihormonal and antibody treatments. Whereas physicians had a quite realistic view of the expected treatment benefits, the patients' expectations were varied. Approximately one-fifth of the patients were willing to accept treatment regimens even with marginal anticipated benefits, whereas one-third required unrealistic treatment benefits. Several influencing factors that were significantly associated with the quality rating of treatment regimens in the groups of breast cancer patients and physicians were also identified. In contrast to physicians, many breast cancer patients required treatment benefits beyond what was realistically possible, although a large group of patients were also satisfied with minimal benefits. Individual factors were also identified in both groups that significantly influence thresholds for accepting adjuvant treatment, independently of risk estimates and therapy guidelines.     

Inhibition of cyclooxygenase-2 causes regression of gastric adenomas in trefoil factor 1 deficient mice

Cyclooxygenase-2 (Cox-2) expression is a marker of reduced survival in gastric cancer patients, and inhibition of Cox-2 suppresses gastrointestinal carcinogenesis in experimental animal models. To investigate the role of Cox-2 in gastric carcinogenesis in vivo, we utilized trefoil factor 1 (Tff1) deficient mice, which model the neoplastic process of the stomach by developing gastric adenomas with full penetrance. These tumors express Cox-2 protein and mRNA, and we have now investigated the effects of genetic deletion of the mouse Cox-2 gene [also known as prostaglandin-endoperoxide synthase 2 (Ptgs2)] and a Cox-2 selective drug celecoxib. Our results show that genetic deletion of Cox-2 in the Tff1 deleted background resulted in reduced adenoma size and ulceration with a chronic inflammatory reaction at the site of the adenoma. To characterize the effect of Cox-2 inhibition in more detail, mice that had already developed an adenoma were fed with celecoxib for 8-14 weeks, which resulted in disruption of the adenoma that ranged from superficial erosion to deep ulcerated destruction accompanied with chronic inflammation. Importantly, mice fed with celecoxib for 16 weeks, followed by control food for 9 weeks, redeveloped a complete adenoma with no detectable inflammatory process. Finally, we determined the identity of the Cox-2 expressing cells and found them to be fibroblasts. Our results show that inhibition of Cox-2 is sufficient to reversibly disrupt gastric adenomas in mice.     

Folate receptor alpha expression in lung cancer: diagnostic and prognostic significance

With the advent of targeted therapies directed towards folate receptor alpha, with several such agents in late stage clinical development, the sensitive and robust detection of folate receptor alpha in tissues is of importance relative to patient selection and perhaps prognosis and prediction of response. The goal of the present study was to evaluate the expression of folate receptor alpha in non-small cell lung cancer specimens to determine its frequency of expression and its potential for prognosis. The distribution of folate receptor alpha expression in normal tissues as well as its expression and relationship to non-small cell lung cancer subtypes was assessed by immunohistochemistry using tissue microarrays and fine needle aspirates and an optimized manual staining method using the recently developed monoclonal antibody 26B3. The association between folate receptor alpha expression and clinical outcome was also evaluated on a tissue microarray created from formalin fixed paraffin embedded specimens from patients with surgically resected lung adenocarcinoma. Folate receptor alpha expression was shown to have a high discriminatory capacity for lung adenocarcinomas versus squamous cell carcinomas. While 74% of adenocarcinomas were positive for folate receptor alpha expression, our results found that only 13% of squamous cell carcinomas were FRA positive (p<0.0001). In patients with adenocarcinoma that underwent surgical resection, increased folate receptor alpha expression was associated with improved overall survival (Hazard Ratio 0.39, 95% CI 0.18-0.85). These data demonstrate the diagnostic relevance of folate receptor alpha expression in non-small cell lung cancer as determined by immunohistochemistry and suggest that determination of folate receptor alpha expression provides prognostic information in patients with lung adenocarcinoma.