A pilot study of visceral fat and its association with adipokines, stool calprotectin and symptoms in patients with diverticulosis

BackgroundComplications of diverticular disease are increasingly common, possibly linked to increasing obesity. Visceral fat could contribute to the development of symptomatic diverticular disease through its pro-inflammatory effects.ObjectiveThe study had 2 aims. A) to develop a semi-automated algorithm to measure abdominal adipose tissue from 2-echo magnetic resonance imaging (MRI) data B) to use this to determine if visceral fat was associated with bowel symptoms and inflammatory markers in patients with symptomatic and asymptomatic diverticular disease.DesignAn observational study measuring visceral fat using MRI together with serum adiponectin, leptin, stool calprotectin and patient-reported somatisation and bowel habit. Setting Medical and imaging research centres of a university hospital. Participants MRI scans were performed on 55 patients after an overnight fast measuring abdominal subcutaneous and visceral adipose tissue volumes together with small bowel water content (SBWC). Blood and stool samples were collected and patients kept a 2 week stool diary and completed a somatisation questionnaire.Main Outcome MeasuresDifference in the volume of visceral fat between symptomatic and asymptomatic patients.ResultsThere were no significant differences in visceral (p = 0.98) or subcutaneous adipose (p = 0.60) tissue between symptomatic and asymptomatic patients. However measured fat volumes were associated with serum adipokines. Adiponectin showed an inverse correlation with visceral adipose tissue (VAT) (Spearman ρ = -0.5, p = 0.0003), which correlated negatively with SBWC (ρ = -0.3, p=0.05). Leptin correlated positively with subcutaneous adipose tissue (ρ = 0.8, p 25 kgm-2) showed a moderate correlation between calprotectin and VAT (ρ = 0.3, p = 0.05). Somatization scores were significantly higher in symptomatic patients (p < 0.0003).ConclusionsIncreasing visceral fat is associated with lower serum adiponectin and increased faecal calprotectin suggesting a pro-inflammatory effect which may predispose to the development of complications of diverticulosis

Differential predictors for alcohol use in adolescents as a function of familial risk

Abstract: Traditional models of future alcohol use in adolescents have used variable-centered approaches, predicting alcohol use from a set of variables across entire samples or populations. Following the proposition that predictive factors may vary in adolescents as a function of family history, we used a two-pronged approach by first defining clusters of familial risk, followed by prediction analyses within each cluster. Thus, for the first time in adolescents, we tested whether adolescents with a family history of drug abuse exhibit a set of predictors different from adolescents without a family history. We apply this approach to a genetic risk score and individual differences in personality, cognition, behavior (risk-taking and discounting) substance use behavior at age 14, life events, and functional brain imaging, to predict scores on the alcohol use disorders identification test (AUDIT) at age 14 and 16 in a sample of adolescents (N = 1659 at baseline, N = 1327 at follow-up) from the IMAGEN cohort, a longitudinal community-based cohort of adolescents. In the absence of familial risk (n = 616), individual differences in baseline drinking, personality measures (extraversion, negative thinking), discounting behaviors, life events, and ventral striatal activation during reward anticipation were significantly associated with future AUDIT scores, while the overall model explained 22% of the variance in future AUDIT. In the presence of familial risk (n = 711), drinking behavior at age 14, personality measures (extraversion, impulsivity), behavioral risk-taking, and life events were significantly associated with future AUDIT scores, explaining 20.1% of the overall variance. Results suggest that individual differences in personality, cognition, life events, brain function, and drinking behavior contribute differentially to the prediction of future alcohol misuse. This approach may inform more individualized preventive interventions

Differential predictors for alcohol use in adolescents as a function of familial risk

Abstract: Traditional models of future alcohol use in adolescents have used variable-centered approaches, predicting alcohol use from a set of variables across entire samples or populations. Following the proposition that predictive factors may vary in adolescents as a function of family history, we used a two-pronged approach by first defining clusters of familial risk, followed by prediction analyses within each cluster. Thus, for the first time in adolescents, we tested whether adolescents with a family history of drug abuse exhibit a set of predictors different from adolescents without a family history. We apply this approach to a genetic risk score and individual differences in personality, cognition, behavior (risk-taking and discounting) substance use behavior at age 14, life events, and functional brain imaging, to predict scores on the alcohol use disorders identification test (AUDIT) at age 14 and 16 in a sample of adolescents (N = 1659 at baseline, N = 1327 at follow-up) from the IMAGEN cohort, a longitudinal community-based cohort of adolescents. In the absence of familial risk (n = 616), individual differences in baseline drinking, personality measures (extraversion, negative thinking), discounting behaviors, life events, and ventral striatal activation during reward anticipation were significantly associated with future AUDIT scores, while the overall model explained 22% of the variance in future AUDIT. In the presence of familial risk (n = 711), drinking behavior at age 14, personality measures (extraversion, impulsivity), behavioral risk-taking, and life events were significantly associated with future AUDIT scores, explaining 20.1% of the overall variance. Results suggest that individual differences in personality, cognition, life events, brain function, and drinking behavior contribute differentially to the prediction of future alcohol misuse. This approach may inform more individualized preventive interventions

Weak Environmental Magnetic Fields Inhibit Spontaneous Bioelectrical Activity in Snail Neurons

The interest in the evaluation of health effects due to EMF has accelerated in the last decades, mostly motivated by the occupational and environmental exposures to humans by such non-ionizing fields. The increasing exposure to electromagnetic fields has been suspected to contribute to the rising incidence of cancer in industrialized countries Despite detailed analysis which provide a wealth of accurate data on the effects of electromagnetic fields on nerve cells, a clear pictures of the mechanism and sites of action of ELF magnetic field in the range of environmental intensities is far from being accomplished and the ionic or metabolic processes underlying the observed effects have not been fully explained. The aim of this study was to evaluate the effects of 50 Hz magnetic fields in the range of environmental intensities on spike and neuronal excitability in snail neurons. We measured the bioelectric parameters of F1 neuron with the conventional intracellular recording in current clamp mode

Effects of Weak Environmental Magnetic Fields on the Spontaneous Bioelectrical Activity of Snail Neurons

We examined the effects of 50-Hz magnetic fields in the range of flux densities relevant to our current environmental exposures on action potential (AP), after-hyperpolarization potential (AHP) and neuronal excitability in neurons of land snails, Helix aspersa. It was shown that when the neurons were exposed to magnetic field at the various flux densities, marked changes in neuronal excitability, AP firing frequency and AHP amplitude were seen. These effects seemed to be related to the intensity, type (single and continuous or repeated and cumulative) and length of exposure (18 or 20 min). The extremely low-frequency (ELF) magnetic field exposures affect the excitability of F1 neuronal cells in a nonmonotonic manner, disrupting their normal characteristic and synchronized firing patterns by interfering with the cell membrane electrophysiological properties. Our results could explain one of the mechanisms and sites of action of ELF magnetic fields. A possible explanation of the inhibitory effects of magnetic fields could be a decrease in Ca2+ influx through inhibition of voltage-gated Ca2+ channels. The detailed mechanism of effect, however, needs to be further studied under voltage-clamp conditions

Reduction of F1 Neuronal Excitability by Exposure to 217 Hz Magnetic Fields from GSM 900 Mobile Phone

Objective: The aim of this study was to investigate the effects of a 217 Hz magnetic field ofmobile phone GSM 900 exposure on the bioelectric activity of F1 neuronal cells of the landsnail.Materials and Methods: According to the magnetic field measurement of the mobile phone,a range of flux intensities of magnetic fields (0.46 - 229 μT) at a frequency of 217 Hz wasproduced by magnetic field coils. The bioelectrical activity of F1 nerve cells at different timeintervals was recorded, using intracellular recording under current clamp conditions in control,sham and field exposed groups.Results: Magnetic field exposure decreased the amplitude of action potential and the firingfrequency of F1 nerve cells. Furthermore, it resulted in a significant (p<0.05) increase inthe amplitude of after hyperpolarization (AHP) and duration of action potential. Change inthe cell’s electrophysiological parameters was associated with a decrease in neuronal excitability.Magnetic field exposure affected also the resting membrane potential of F1 cells in abimodal fashion, including depolarization and hyperpolarization. Considering the exposurecondition, most of the alterations in the electrical activity of F1 nerve cells induced by magneticfields exposure were reversible.Conclusion: These findings suggest that 217 Hz magnetic fields of mobile phones with differentintensities affect the spontaneous bioelectrical activity of F1 nerve cells and exert inhibitoryeffects on neuronal excitability. There is evidence for the existence of an amplitudewindow and these electrophysiological alterations occur within this amplitude window. Thereversibility of the magnetic field- induced most electrophysiological alterations in the neuronalbehavior under our experimental conditions was observed

The Measurement of Low Frequency Magnetic Field of Two Kinds of GSM900 Mobile Phone

Introduction:  The  use  of  mobile  communication  systems  has  dramatically  increased  over  the  past  decade. Although many studies have been performed to determine the effect of radio frequency (RF) but  less attention has been paid to the possible biological impact of exposure to extremely low frequency  (ELF) components.   The objective of this study is two folds. One is to design the equipments needed for the measurement of  the ELF fields of two types of GSM900 mobile phone. Secondly, use a protocol suitable for an accurate  assessment of the ELF fields.  Materials  and Methods:  First  a  home-made  search  coil  was  provided  and  calibrated precisely  under  several experiments. Using Fast Fourier Transform, the power spectrum density of the induced voltage in  the search coil was analyzed and the amplitudes of 217 Hz and its harmonics were extracted and then the  distribution of magnetic field in the back side of mobile phones was determined.  Results: The values of B-field on the back side of the two kinds of GSM mobile phone were different.  They  were  between  50  to  160  µT in  Nokia  3310  and  14  to  30  µT in  Nokia  8310.  Considering  the  difference between the amplitudes of frequency components at 217 Hz and its harmonics in the two kinds  of mobile phone, a range of magnetic flux density at different times in a five day period was measured.  Discussion and Conclusion: These findings emphasize the need for considering the distribution of low  frequency magnetic field from mobile phone when biological effects of magnetic fields are studied. To  determine  the  intensity  windowing  effect,  one  must  consider  the  physical  characteristics  of  the  fundamental  frequency  component  wave  (217  Hz)  and  its  harmonics  produced  by  the  mobile  phone  similar to the one generated under a real situation

Analgetic effects of non-thermal GSM-1900 radiofrequency electromagnetic fields in the land snail Helix pomatia

Purpose : To investigate whether mobile phone radiation might affect snail nociception, employing radiofrequency (RF) electromagnetic fields (EMF) which, to our knowledge, have hitherto not been studied in a snail model. Exposure to extremely low frequency (ELF) magnetic fields has however been shown to significantly affect nociceptive responses. Materials and methods : In the present study, we exposed 29 land snails of the strain Helix pomatia to global system for mobile communications (GSM) EMF at 1900 MHz at the non-thermal level 48 mW/kg for 1 hour each and 29 snails were sham controls. The experiments took place during the onset of summer, with all snails being well out of hibernation. Before and after GSM or sham exposure, the snails were subjected to thermal pain by being placed on a hot plate. The reaction time for retraction from the hot plate was measured by two blinded observers. Results : Comparing the reaction pattern of each snail before and after exposure, the GSM-exposed snails were less sensitive to thermal pain as compared to the sham controls, indicating that RF exposure induces a significant analgesia (Mann-Whitney p < 0.001). Conclusion : This study might support earlier findings, describing beneficial effects of EMF exposure upon nociception

Calcium efflux of plasma membrane vesicles exposed to ELF magnetic fieldsutest of a nuclear magnetic resonance interaction model

The question whether very weak, low frequency magnetic fields can affect biological matter is still under debate. The theoretical possibility of such an interaction is often questioned and the site of interaction in the cell is unknown. In the present study, the influence of extremely weak 60?Hz magnetic fields on the transport of Ca2+ was studied in a biological system consisting of highly purified plasma membrane vesicles. We tested a newly proposed quantum mechanical model postulates that polarization of hydrogen nuclei can elicit a biological effect. Vesicles were exposed for half an hour at 32?degrees C and the calcium efflux was studied using radioactive 45Ca2+ as a tracer. A static magnetic field of 26?mu T and time-varying magnetic fields with a frequency of 60?Hz and amplitudes between 0.6 and 6.3?mu T were used. The predictions of the model, proposed by Lednev, that at a frequency of 60?Hz the biological effect under investigation would significantly be altered at the amplitudes of 1.3 and 3.9?mu T could not be confirmed. Bioelectromagnetics 33:535542, 2012. (c) 2012 Wiley Periodicals, Inc

Nonthermal GSM RF and ELF EMF effects upon rat BBB permeability

Since the late 1980s, our group has examined the effects of radiofrequency electromagnetic fields (RF-EMF), including pulse-modulated waves of the type emitted by mobile phones, upon the blood-brain barrier. In more than 2,000 rats, we have repeatedly demonstrated a passage of the rats' own albumin from the blood through the brain capillaries into the surrounding brain parenchyma at SAR values down to 0.1mW/kg. In most of these experiments, the animals were exposed in TEM-cells, ventilated by an external electrical fan at 50 Hz. In the present study, we examined whether the extremely low frequency (ELF) magnetic fields from the fan (50 Hz, 0.3-1.5 μT) might add to the RF effect. Sixty-four rats were divided into 4 groups: RF only, ELF only and RF + ELF exposure plus a sham group. The GSM-900 MHz RF exposure was at the very low, nonthermal, average whole-body SAR level 0.4 mW/kg. Demonstration of the normally occurring albumin extravasation in the basal hypothalamus is our inbuilt control proving that the staining is reliable. Two full series of staining of the whole material gave negative results for hypothalamus. Not until we changed to avidin, biotin, and antibodies from a third supplier, we received an acceptable staining. Twenty-five percent of the RF animals had a pathological albumin leakage, while the ELF and RF + ELF groups with three and two pathological findings, respectively, were not significantly different from the control group. We conclude that the use of external fans has had no major influence upon the result