Clinical features of cases of influenza A (H1N1)v in Osaka prefecture, Japan, May 2009

This report describes the clinical characteristics of influenza A(H1N1)v virus infection in Osaka. By the end of May, 171 cases had been reported in Osaka. Most patients were from one school. No patient had a serious underlying medical condition.Clinical symptoms were mild and resembled those of seasonal influenza. The sensitivity of the rapid antigen test was 77%. Antivirals were given to the majority of the cases. Early antiviral treatment may have shortened the duration of fever.

Epidemiology of influenza A(H1N1)v virus infection in Japan, May - June 2009

Between 9 May and 4 June 2009, a total of 401 laboratory-confirmed cases of influenza A(H1N1)v virus were reported in Japan, from 16 of the 47 Japanese prefectures. The two areas most affected were Osaka prefecture and Kobe city where outbreaks in high schools occurred leading to school closures. To date all cases have had symptoms consistent with seasonal influenza and no severe or fatal cases have been reported.

The virtues of a deliberately mis-specified disease model in demonstrating a gene-environment interaction

OBJECTIVES

This study seeks to assess the impact of measurement errors in cumulative exposure on estimates of a gene-environment interaction in a nested case-control study in occupational epidemiology. In the approach considered here, exposure intensity is assessed at the group level and the exposure duration individually (both with error). Genetic susceptibility is assumed to be known exactly. Differences in "gene" are assumed to affect disease risk only in exposed subjects.

METHODS

Three data analysis strategies were considered: one using a correctly specified disease model (exposure and exposure-gene interaction), and two using mis-specified disease models, one with "gene" as the only risk factor ("gene-only" model) and the other with main effects of both gene and exposure along with their interaction ("full" model).

RESULTS

In simulations, estimates of the gene-environment interaction based on the correctly specified disease model were greatly attenuated and power was diminished appreciably even when errors in exposure were modest. Significant associations were detected more frequently in the gene-only model when errors in exposure were large. When the "full" mis-specified model was fitted to the simulated data, it yielded erratic estimates. This is illustrated in an analysis of the interaction of cumulative exposure to organophosphate pesticides and paraoxonase gene on the risk of chronic neuropsychological effects among farmers who dip sheep.

CONCLUSION

If "gene" contributes to disease risk only in the presence of exposure, the existence of the gene-environment interaction can be efficiently inferred from a deliberately mis-specified "gene-only" disease model in nested case-control studies.

Pathway analysis of microarray data via regression

Pathway analysis of microarray data evaluates gene expression profiles of a priori defined biological pathways in association with a phenotype of interest. We propose a unified pathway-analysis method that can be used for diverse phenotypes including binary, multiclass, continuous, count, rate, and censored survival phenotypes. The proposed method also allows covariate adjustments and correlation in the phenotype variable that is encountered in longitudinal, cluster-sampled, and paired designs. These are accomplished by combining the regression-based test statistic for each individual gene in a pathway of interest into a pathway-level test statistic. Applications of the proposed method are illustrated with two real pathway-analysis examples: one evaluating relapse-associated gene expression involving a matched-pair binary phenotype in children with acute lymphoblastic leukemia; and the other investigating gene expression in breast cancer tissues in relation to patients' survival (a censored survival phenotype). Implementations for various phenotypes are available in R. Additionally, an Excel Add-in for a user-friendly interface is currently being developed.

Bacterial components regulate the expression of Toll-like receptor 4 on human mast cells

OBJECTIVES AND DESIGN

The aim of this study was to investigate whether the exposure of mast cells (MCs) to bacterial components affects the expression of Toll-like receptor (TLR) 4, and to elucidate the behavior of MCs during the early response to infection.

MATERIALS

Two human MC lines, HMC-1 and LAD2, were employed. Messenger RNA expression was observed by RT and real-time PCR. TLR4 expression was determined by Western blotting. TNF-alpha secretion was analyzed with ELISA. The degranulation ratio was measured with betahexosaminidase assay.

RESULTS

Although bacterial components increased TLR4 mRNA, only lipopolysaccharide (LPS) augmented the TLR4 protein expression. LAD2 pre-treated with LPS for 8 h resulted in 2-fold increased TNF-alpha secretion on LPS restimulation.

CONCLUSION

These results suggest that the exposure of MCs to LPS may reinforce the innate immune system due to up-regulation of MC TLR4, followed by increased TNF-alpha release.

Long-term complications of neuroblastoma: A report from the Childhood Cancer Survivor Study

9544

Background: Neuroblastoma (NB) survivors can develop many complications from their treatment. We evaluated long-term morbidity and mortality in a large cohort of NB survivors. Procedures: Late effects data from 5-year NB survivors diagnosed between 1970–1986 enrolled in the Childhood Cancer Survivor Study (CCSS) were collected from self-administered questionnaires. 832 survivors and 3,899 siblings were included. Treatment data were abstracted from the medical records of all survivors. Late mortality, second malignant neoplasm (SMN), and chronic health conditions were analyzed in relation to treatment factors. Results: 42 survivors (6%) died more than 5 years after their diagnosis (standardized mortality ratio [SMR]:4.8; 95% CI 3.5–6.5). Causes of death included: disease recurrence (n=23), SMN (n=6) (SMR: 8.5; 95% CI 3.1–18.4), cardiac (n=1) (SMR 2.9; 95% CI 0.04–16.0), pulmonary (n=1) (SMR 4.8; 95% CI 0.1–26.5), external causes (n=4), other and unknown (n=11). 33 developed a SMN (standardized incidence ratio [SIR] 8.6; 95% CI 5.9–12.1): thyroid (n=7), renal (n=6), soft tissue sarcomas (n=3), acute myeloid leukemia (n=2), breast cancer (n=2) and other (n=13). Exposure to radiation therapy (RT) (p=0.003) and to VP-16 (p=0.04) were significant risk factors for SMN. 38% of the survivors reported at least one chronic health condition. Compared to siblings, they were more likely to report any chronic condition (risk ratio [RR] 14.7; 95% CI, 12.4–17.6). The most common prevalent conditions included: musculoskeletal (RR 49.8; 95% CI, 27.9–88.8), endocrine (RR 36.2; 95%CI 24.1–54.5), sensory (RR 21.5; 95%CI, 14.6–31.7) and neurological (RR 13.1; 95% CI 10.8–16). A multivariable Poisson regression analysis revealed the following associations: laminectomy (RR 8.6; 95% CI 3.5- 21) and chest RT (RR 2.8; 95% CI 1.3–6.5) as risk factors for scoliosis; age < 1 year at diagnosis (RR 1.9; 95% CI 1.4–2.6) and laminectomy (RR 3.5; 95% CI 2.4–5.3) for neurological complications; for hearing loss, increasing cumulative dose of cisplatin (for ≥ 600 mg/m2 RR 52.8; 95% CI 10.2–272.5); and RT to the neck (RR 6.6; 95% CI 2.4–18) for hypothyroidism. Conclusions: NB survivors are at risk of developing chronic conditions. Long-term surveillance is required for early detection of these complications.

No significant financial relationships to disclose.

Obesity in adult survivors of childhood acute lymphoblastic leukemia: A follow-up report from the Childhood Cancer Survivor Study

9518

Background: We previously reported an association between ≥ 20 Gy cranial radiotherapy (CRT) and obesity in adult survivors of childhood ALL. This follow-up study aimed to determine if, with time, (1) the prevalence of obesity and (2) the rate of BMI change were increased in ALL survivors in comparison with sibling controls. Methods: A longitudinal cohort comparing 1,451 adult survivors of childhood ALL (mean age 32.3 years) to 2,167 siblings of childhood cancer survivors (mean age 35.9 years). BMI was calculated from self- reported heights and weights and used to determine the prevalence of being overweight (25.0 ≤ BMI < 30.0) or obese (BMI ≥ 30.0). Polytomous logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for being overweight or obese among ALL survivors compared to sibling controls. BMIs at baseline and follow-up (with a mean interval of 7.8 years) were used to calculate mean BMI increases per year occurring between these timepoints. Results: Age- and race-adjusted ORs for obesity among survivors compared with siblings are shown in the table . Notably, 10–19 Gy CRT was associated with an increased likelihood of being obese in comparison with siblings. In longitudinal analysis, survivors who were treated with CRT had a significantly greater net increase in BMI/year in comparison with siblings. At follow-up, 69.7% of females treated with ≥ 20 Gy CRT prior to the age of 10 were overweight (31.1%) or obese (38.6%). Conclusion: Cranial radiotherapy ≥ 10 Gy employed in the treatment of childhood ALL is strongly associated among both male and female survivors with increases in the prevalence of obesity and average BMI gains over time. Female survivors who received CRT ≥ 20 Gy, particularly those treated at a younger age, were most affected.

[Table: see text]

No significant financial relationships to disclose.

Multiscale processing of mass spectrometry data

This work addresses the problem of extracting signal content from protein mass spectrometry data. A multiscale decomposition of these spectra is used to focus on local scale-based structure by defining scale-specific features. Quantification of features is accompanied by an efficient method for calculating the location of features which avoids estimation of signal-to-noise ratios or bandwidths. Scale-based histograms serve as spectral-density-like functions indicating the regions of high density of features in the data. These regions provide bins within which features are quantified and compared across samples. As a preliminary step, the locations of prominent features within coarse-scale bins may be used for a crude registration of spectra. The multiscale decomposition, the scale-based feature definition, the calculation of feature locations, and subsequent quantification of features are carried out by way of a translation-invariant wavelet analysis.

Troglitazone and 9cis,11trans,13trans-conjugated linolenic acid: comparison of their antiproliferative and apoptosis-inducing effects on different colon cancer cell lines

BACKGROUND

We have previously reported that troglitazone, a synthetic ligand for peroxisome proliferator-activated receptor gamma (PPARgamma), and bitter gourd seed oil rich in 9cis,11trans,13trans-conjugated linolenic acid (9c,11t,13t-CLN) prevent colon carcinogenesis. To evaluate the chemotherapeutic effect and potency of these compounds on colon cancer cells, we investigated their antiproliferative and apoptosis-inducing effects using different human colon cancer cell lines.

METHODS

The antiproliferative and apoptosis-inducing effects of troglitazone and 9c,11t,13t-CLN were evaluated and compared using HT-29, DLD-1 and Caco-2 cells at different stages of enterocytic differentiation.

RESULTS

Troglitazone and 9c,11t,13t-CLN decreased cell viability and induced apoptosis in three colon cancer cell lines. The susceptibility of HT-29, which expresses PPARgamma at high levels, to troglitazone and 9c,11t,13t-CLN was higher than that of Caco-2 cells with low levels of PPARgamma.

CONCLUSION

Troglitazone and 9c,11t,13t-CLN exhibited more effective chemotherapeutic effects on HT-29 cells than on Caco-2 cells.

Folic acid supplementation during methotrexate immunosuppression is not associated with early toxicity, risk of acute graft-versus-host disease or relapse following hematopoietic transplantation

Methotrexate (MTX) is used as an immunosuppressive agent for acute graft-versus-host disease (GVHD) prophylaxis following hematopoietic cell transplantation (HCT). Concerns that folate intake may impair MTX effectiveness or selectively rescue leukemic cells have led to variations in clinical practice regarding supplemental folic acid during MTX administration. A retrospective, observational study was undertaken to determine the association between folic acid intake (days 0-18 post transplant) and MTX toxicity and efficacy following HCT. The study population consisted of 311 adult patients who received a myeloablative HCT for chronic myelogenous leukemia, all four scheduled doses of MTX, and did not require leucovorin rescue. Multiple linear regression models were used to assess the relationships between folic acid intake (days 0-18 post-HCT) and oral mucositis index (OMI) scores, time to engraftment and risk of detectable acute GVHD. No statistically significant differences in mean OMI scores, time to engraftment, risk of acute GVHD, days to acute GVHD, risk of relapse or survival were observed when comparing patients taking, on average, <400 (14%), 400 (58%) or >400 microg (28%) folic acid per day. Our results suggest that concurrent folic acid supplementation does not change MTX effectiveness or toxicity in this patient population.

Metamodels of bias in Cox proportional-hazards and logistic regressions with heteroscedastic measurement error under group-level exposure assessment

In occupational epidemiology, group-based exposure assessment entails estimating the average exposure level in a group of workers and assigning the average to all members of the group. The assigned exposure values can be used in epidemiological analyses and have been shown to produce virtually unbiased relative-risk estimates in many situations. Although the group-based exposure assessment continues to be used widely, it is unclear whether it produces unbiased relative-risk estimates in all circumstance, specifically in Cox proportional-hazards and logistic regressions when between-worker variance is not constant but proportional to the true group mean. This question is important because (i) between-worker variance has been shown to differ among exposure groups in occupational epidemiological studies and (ii) recent theoretical work has suggested that bias may exist in such situations. We conducted computer simulations of occupational epidemiological studies to address this question and analysed simulation results using 'metamodelling'. The results indicate that small-to-negligible bias can be expected to result from heteroscedastic between-worker variance. Cox proportional-hazards models can produce attenuated risk estimates, while logistic regression may result in overestimation of risk gradient. Bias caused by ignoring the heteroscedastic measurement error is unlikely to be large enough to alter the conclusion about the direction of exposure-disease association in occupational epidemiology.

Function and quality-of-life of survivors of pelvic and lower extremity osteosarcoma and Ewing's sarcoma: the Childhood Cancer Survivor Study

Limb-sparing surgeries have been performed more frequently than amputation based on the belief that limb-sparing surgeries provide improved function and quality-of-life (QOL). However, this has not been extensively studied in the paediatric population, which has unique characteristics that have implications for function and QOL. Using the Childhood Cancer Survivor Study, 528 adult long-term survivors of pediatric lower extremity bone tumours, diagnosed between 1970 and 1986, were contacted and completed questionnaries assessing function and QOL. Survivors were an average of 21 years from diagnosis with an average age of 35 years. Overall they reported excellent function and QOL. Compared to those who had a limb-sparing procedure, amputees were not more likely to have lower function and QOL scores and self-perception of disability included general health status, lower educational attainment, older age and female gender. Findings from this study suggest that, over time, amputees do as well as those who underwent limb-sparing surgeries between 1970 and 1986. However, female gender, lower educational attainment and older current age appear to influence function, QOL and disability.

Experimental determination of minimal stimulation current and period for electrical thrombosis in dogs

SUMMARY

Endovascular surgery has been proposed as an alternative treatment for cerebral aneurysms. However, for wide neck and large sized lesions it is very difficult to obtain complete occlusion and tissue organization. The present study was conducted to examine the efficacy of electrical thrombosis for cerebral aneurysms and parent arterial occlusions using Interlocking Detachable Coils (IDCs), focusing on the minimum current volume and stimulation time required for stable electrical thrombosis formation. We used ten mixed-breed adult dogs (in the study body weights 9-12 kg; males: 5, females: 5). Guiding catheter sand microcatheters were introduced into both sides of the distal external carotid artery (ECA) and placed at the same level. To prevent migration, IDCs (4 mm x 12 cm) were placed in the ECA without being detached. After confirming no vessel occlusion, we applied a positive current (2-6 mA) to the coil on one side and performed angiography every ten minutes to observe whether vessel occlusion with electrothrombosis had occurred. It was determined that to achieve complete occlusion of the external carotid arteries in mixedbreed dogs, a minimum stimulation current of 4mA and a minimum stimulation time of ten to 20 minutes are required.