Clinical presentation of young people (10–24 years old) with brain tumors: results from the international MOBI-Kids study

Journal of Neuro-Oncology - We used data from MOBI-Kids, a 14-country international collaborative case–control study of brain tumors (BTs), to study clinical characteristics of the tumors in...     

Obesity and risk of malignant melanoma: A meta-analysis of cohort and case–control studies

Although obesity is an established risk factor for several cancer types, its possible role in the aetiology of malignant melanoma remains unclear. This meta-analysis aims to examine the association between obesity and melanoma risk, exploring any tentative gender-specific associations. After the identification of eligible studies, we estimated pooled effect estimates (odds ratios and relative risks), undertook a meta-regression analysis and analysed separately risk of malignant melanoma among males and females in relation to body mass index (BMI) and body surface area (BSA). Out of the 21 eligible articles, 11 used a case–control design encompassing 4460 cases/6342 controls; 10 used a cohort design whose total size comprised 7895 incident cases/6,368,671 subjects. Among males, the pooled effect estimate was 1.31 (95% confidence interval (CI): 1.18–1.45) for overweight and 1.31 (95% CI: 1.19–1.44) for obese. Meta-regression revealed no significant slope, most probably due to the underlying plateau in effect estimates. Among females, no significant association was documented; the pooled effect estimate for overweight and obese subjects was 0.98 (95% CI: 0.92–1.05) and 0.99 (95% CI: 0.83–1.18), respectively. Noticeably, there was evidence for confounding between sunlight exposure and obesity in females. All results were reproducible upon analyses on BSA. In conclusion, overweight and obesity are associated with increased risk of malignant melanoma among males. Meticulous assessment of sunlight exposure is needed especially in women, since self limited public sun exposure may be prevalent among overweight or obese females. Higher-order associations between BMI and melanoma risk should be addressed and examined by the future studies.     

Periods of rest in fMRI contain individual spontaneous events which are related to slowly fluctuating spontaneous activity

fMRI studies of brain activity at rest study slow (<0.1 Hz) intrinsic fluctuations in the blood‐oxygenation‐level‐dependent (BOLD) signal that are observed in a temporal scale of several minutes. The origin of these fluctuations is not clear but has previously been associated with slow changes in rhythmic neuronal activity resulting from changes in cortical excitability or neuronal synchronization. In this work, we show that individual spontaneous BOLD events occur during rest, in addition to slow fluctuations. Individual spontaneous BOLD events were identified by deconvolving the hemodynamic impulse response function for each time point in the fMRI time series, thus requiring no information on timing or a‐priori spatial information of events. The patterns of activation detected were related to the motor, visual, default‐mode, and dorsal attention networks. The correspondence between spontaneous events and slow fluctuations in these networks was assessed using a sliding window, seed‐correlation analysis, where seed regions were selected based on the individual spontaneous event BOLD activity maps. We showed that the correlation varied considerably over time, peaking at the time of spontaneous events in these networks. By regressing spontaneous events out of the fMRI signal, we showed that both the correlation strength and the power in spectral frequencies <0.1 Hz decreased, indicating that spontaneous activation events contribute to low‐frequency fluctuations observed in resting state networks with fMRI. This work provides new insights into the origin of signals detected in fMRI studies of functional connectivity. Hum Brain Mapp, 2013. © 2012 Wiley Periodicals, Inc.     

The association between CagA status and the development of esophagitis after the eradication of Helicobacter pylori

BACKGROUND: Strains of Helicobacter pylori with the cytotoxine-associated gene A (cagA) are linked to severe forms of gastroduodenal disease. Although eradication of H. pylori may predispose to the development of reflux esophagitis, the effects of CagA status on risk of esophagitis after successful H. pylori treatment are not known.

METHODS: We studied 50 consecutive patients without esophagitis in whom H. pylori was eradicated successfully. CagA status was determined by immunoblotting sera from patients against H. pylori antigens. Patients underwent upper gastrointestinal endoscopy before eradication and 6, 12, 18, and 24 months after eradication or when reflux symptoms occurred. Biopsy specimens of the antrum and corpus were evaluated for gastritis before H. pylori eradication and at the end of the study. The sum of the scores for acute and chronic inflammation (both measured on a 0 [absent] to 3 [severe] scale) comprised the total gastritis severity score.

RESULTS: In a multivariate proportional hazards regression analysis, positive CagA serology (hazard ratio [HR] = 10, 95% confidence interval [CI]: 1.3 to 81) and moderate-to-severe corpus gastritis (total severity score ≥4) before eradication (HR = 2.3, 95% CI: 1.2 to 6.1) were independent risk factors for the development of esophagitis after H. pylori eradication.

CONCLUSION: Patients infected with strains of H. pylori that are cagA-positive are at increased risk of developing esophagitis after eradication of H. pylori.     

Effect of chronic exercise on DNA fragmentation and on lipid profiles in rat skeletal muscle

The concentration and fatty acid composition of phospholipids in animal cells are important determinants of membrane function. Membrane function may influence apoptosis, a biological process that is crucial for the normal development and function of the body. Few and conflicting data exist regarding the effect of chronic exercise on apoptosis in skeletal muscle, and no data exist regarding the effect of chronic exercise on the fatty acid composition of individual muscle phospholipids. We therefore examined the effects of 8 weeks of voluntary wheel running on DNA fragmentation (an index of apoptosis) and on the concentration and fatty acid composition of individual muscle phospholipids and ceramide (a lipid involved in apoptotic signalling) in rat gastrocnemius muscle by comparing 11 trained and 14 untrained male Wistar rats. The trained animals had significantly ( P < 0.05) higher cytochrome c oxidase activity (an index of aerobic adaptation) and lower phosphatidyl inositol concentration compared with their untrained counterparts. Groups did not differ in DNA fragmentation or any other lipid parameter. Our findings suggest that chronic wheel running did not affect apoptosis or the concentration and fatty acid composition of most phospholipids and ceramide in rat gastrocnemius muscle. Given the participation of several phospholipids and ceramide in apoptotic signalling, it appears that the lack of changes in the lipid parameters is in agreement with the lack of change in DNA fragmentation with exercise.     

Incidence and time trends of childhood lymphomas: findings from 14 Southern and Eastern European cancer registries and the Surveillance,Epidemiology and End Results,USA

Purpose

To describe epidemiologic patterns of childhood (0–14 years) lymphomas in the Southern and Eastern European (SEE) region in comparison with the Surveillance, Epidemiology and End Results (SEER), USA, and explore tentative discrepancies.

Methods

Childhood lymphomas were retrieved from 14 SEE registries (n = 4,702) and SEER (n = 4,416), diagnosed during 1990–2014; incidence rates were estimated and time trends were evaluated.

Results

Overall age-adjusted incidence rate was higher in SEE (16.9/10⁶) compared to SEER (13.6/10⁶), because of a higher incidence of Hodgkin (HL, 7.5/10⁶ vs. 5.1/10⁶) and Burkitt lymphoma (BL, 3.1 vs. 2.3/10⁶), whereas the incidence of non-Hodgkin lymphoma (NHL) was overall identical (5.9/10⁶ vs. 5.8/10⁶), albeit variable among SEE. Incidence increased with age, except for BL which peaked at 4 years; HL in SEE also showed an early male-specific peak at 4 years. The male preponderance was more pronounced for BL and attenuated with increasing age for HL. Increasing trends were noted in SEER for total lymphomas and NHL, and was marginal for HL, as contrasted to the decreasing HL and NHL trends generally observed in SEE registries, with the exception of increasing HL incidence in Portugal; of note, BL incidence trend followed a male-specific increasing trend in SEE.

Conclusions

Registry-based data reveal variable patterns and time trends of childhood lymphomas in SEE and SEER during the last decades, possibly reflecting diverse levels of socioeconomic development of the populations in the respective areas; optimization of registration process may allow further exploration of molecular characteristics of disease subtypes.

     

Diet and peripheral arterial occlusive disease: the role of poly-, mono-, and saturated fatty acids

A case-control study concerning the association between diet and peripheral arterial occlusive disease was conducted in Athens, Greece. The case series consisted of 100 patients with this disease, whereas controls were 100 patients with conditions requiring minor surgical care who were admitted to the same teaching hospital. Diet was ascertained through a semiquantitative food frequency questionnaire. Nutrient intakes for individuals were estimated by multiplying the nutrient content of a selected typical portion size for each specified food item by the frequency that the food was used per month and summing these estimates for all food items. Data were analyzed using multiple logistic regression procedures, controlling for total energy intake by taking nutrient residuals and by using multivariate nutrient density models. Saturated fatty acids (odds ratio (OR) and 95% confidence interval (CI) contrasting the 75th centile (upper) with the 25th centile = 1.96 and 1.14-3.39), proteins (OR = 2.86, 95% CI 1.47-5.55), and dietary cholesterol (OR = 6.07, 95% CI 2.74-13.46) were associated with increased risk of peripheral arterial occlusive disease, whereas polyunsaturated fatty acids (OR = 0.48, 95% CI 0.24-0.93) and crude fiber (OR = 0.33, 95% CI 0.17-0.64) were related to reduced risk. Monounsaturated fatty acids and, by inference, olive oil occupy an intermediate neutral position between polyunsaturates and saturates (corresponding OR = 1.14, 95% CI 0.68-1.91). Higher intakes of fiber and vitamin C were associated with lower risk of peripheral arterial occlusive disease. The low occurrence of atherosclerotic diseases in Greece and other Mediterranean countries may be due to the substitution of olive oil in place of saturated fats and/or the consumption of a diet high in vegetables, fruits, and other fiber-containing foods.