Functional target volume delineation for radiation therapy on the basis of positron emission tomography and the correlation with histopathology

Accurate target volume delineation becomes more and more important for modern high-precision radiotherapy. During the last years, molecular imaging using positron emission tomography (PET) has been shown to be of high clinical impact on diagnosis, staging and/or restaging of many malignancies. Therefore, the integration of PET-data into the radiotherapy planning process is of high interest in radio-oncology. During the last years a number of automatic and semi-automatic PET-based volume delineation methods have been developed which will be presented in this review. We will not only describe those algorithms currently used in clinical settings, but also present some of the latest developments in this highly dynamic field of research. Furthermore, validation of different segmentation approaches against histopathology is discussed.

An effective lifestyle intervention in overweight children: findings from a randomized controlled trial on "Obeldicks light"

BACKGROUND & AIMS

Randomized controlled trials (RCT) have demonstrated the effectiveness of lifestyle interventions in obese children. However, the effectiveness of interventions for overweight, but no obese children has not been demonstrated yet by RCTs.

METHODS

A total of 66 overweight (BMI>90th< or =97th percentile) children (mean age 11.5+/-1.6 years, 58% females, mean BMI 23.4+/-1.5kg/m(2)) were randomized into a control group (CG) (n=32; no intervention for a duration of 6 months) or intervention group (IG) (n=34; 6 months intervention "Obeldicks light" based on physical activity, nutrition education, and behaviour counselling). BMI, waist circumference, skinfold thickness, bioimpedance analyses, blood pressure, physical activity based on questionnaires, and three-day-weighed dietary records were determined at baseline (T0) and 6 months (T1) later. Degree of overweight was calculated as BMI-SDS. Comparisons were performed on an intention-to-treat approach.

RESULTS

The drop-out rate was 3% in IG and 16% in CG. At T1, 94% of the children in IG decreased their BMI-SDS and 24% of them were normal weight. The changes between T0 and T1 in BMI-SDS differed significantly (p<0.001) between IG and CG (CG: +0.05+/-0.19 BMI-SDS; IG: -0.26+/-0.22 BMI-SDS). Similar findings were observed for blood pressure, waist circumference, skinfold thickness, and fat mass based on bioimpedance analyses. In the IG, energy, fat and sugar intake decreased significantly between T0 and T1, while no significant changes were observed in the CG.

CONCLUSIONS

The lifestyle intervention was associated with an improvement of dietary patterns and was effective in reducing degree of overweight, fat mass, waist circumference, and blood pressure.

Para-[(123)I]iodo-L-phenylalanine in patients with pancreatic adenocarcinoma: tumour uptake, whole-body kinetics, dosimetry

Recently, p-[(123)I]iodo-L-phenylalanine (IPA) was clinically validated for brain tumour imaging. Preclinical studies demonstrated uptake of IPA into pancreatic adenocarcinoma suggesting its diagnostic application in patients with pancreatic tumours. The aim was to study the tumour uptake of IPA in patients with pancreatic adenocarcinoma and to analyse its biodistribution and dosimetry to assess the radiation dose resulting from its diagnostic use.

PATIENTS, METHODS

Seven patients with pancreatic adenocarcinoma underwent whole-body scintigraphies and SPECT up to 24 h after administration of 250 MBq of IPA. Tumour uptake of IPA was assessed visually. Time activity curves and the corresponding residence times were determined for whole-body, kidneys, liver, spleen, lung, heart content, brain, and testes. Mean absorbed doses for various organs and the effective dose were assessed based on the MIRD formalism using OLINDA/EXM.

RESULTS

IPA exhibited no accumulation in proven manifestations of pancreatic adenocarcinomas. IPA was exclusively eliminated by the urine and showed a delayed clearance from blood. Residence times were 0.26 +/- 0.09 h for kidneys, 0.38 +/- 0.19 h for liver, 0.15 +/- 0.07 h for spleen, 0.51 +/- 0.20 h for lungs, 0.22 +/- 0.07 h for heart content, 0.11 +/- 0.05 h for brain, 0.014 +/- 0.005 h for testes and 6.4 +/- 2.2 h for the remainder. The highest absorbed doses were determined in the urinary bladder wall and in the kidneys. According to the ICRP 60 the effective dose resulting from 250 MBq IPA was 3.6 +/- 0.7 mSv.

CONCLUSION

Para-[(123)I]iodo-L-phenylalanine can be used in diagnostic nuclear medicine with acceptable radiation doses. Besides its proven validity for brain tumour imaging, IPA does not appear to be suitable as tracer for pancreatic cancer.

Estimating the impact of alcohol consumption on survival for HIV+ individuals

Alcohol consumption is associated with decreased antiretroviral adherence, and decreased adherence results in poorer outcomes. However the magnitude of alcohol's impact on survival is unknown. Our objective was to use a calibrated and validated simulation of HIV disease to estimate the impact of alcohol on survival. We incorporated clinical data describing the temporal and dose-response relationships between alcohol consumption and adherence in a large observational cohort (N=2,702). Individuals were categorized as nondrinkers (no alcohol consumption), hazardous drinkers (consume > or =5 standard drinks on drinking days), and nonhazardous drinkers (consume <5 standard drinks on drinking days). Our results showed that nonhazardous alcohol consumption decreased survival by more than 1 year if the frequency of consumption was once per week or greater, and by 3.3 years (from 21.7 years to 18.4 years) with daily consumption. Hazardous alcohol consumption decreased overall survival by more than 3 years if frequency of consumption was once per week or greater, and by 6.4 years (From 16.1 years to 9.7 years) with daily consumption. Our results suggest that alcohol is an underappreciated yet modifiable risk factor for poor survival among individuals with HIV.

Migration from can coatings: Part 2. Identification and quantification of migrating cyclic oligoesters below 1000 Da

Metal cans for food use can be coated with lacquers based on polyester resins. Recent research has focussed on the identification and quantification of migrants released by coatings that are potentially absorbable (below 1000 Da). The presented method describes a procedure that was optimized to hydrolyse the polyester migrants into their monomers, polyvalent acids and polyols. The polyols were identified by gas chromatography with flame ionization detection GC-FID and the acids by high-performance liquid chromatography (HPLC) coupled with an ultraviolet and an electrospray ionization-mass selective detector (HPLC-ESI-MSD/UVD), respectively. With the knowledge of the polyester monomers, it was possible--at least tentatively--to identify the main components in the migrate as cyclic oligoesters by HPLC-ESI-MSD/UVD. A cyclic oligomer, CYCLO [3IPA (isophthalic acid) 3EG (ethylene glycol)] was synthesized and characterized by infrared, nuclear magnetic resonance and mass spectrometry as well as by elementary analysis for further confirmation. To determine the amount of migrating cyclic oligoesters, the response of the migrating substances was compared using different detectors, UVD, MSD and evaporative light scattering detector (ELSD). The response of the ELSD was dependent on the molecular weight of the analytes that reduced the accuracy of this detection type. The wavelength with the same absorption coefficient for IPA and terephthalic acid (TPA) was obtained at 232 nm. The UV(232nm) response of an oligoester is proportional to the number of its IPA/TPA moieties, which was verified for several TPA/IPA esters. The amount of the migrating oligoesters was determined using an UV(232nm) calibration of a commercially available TPA ester and the number of IPA/TPA moieties molecules gained from the ESI-MSD spectra. According to this method, the amount of migrating oligoesters below 1000 Da in the 95% ethanol migrate varied from 0.1 to 0.6 mg dm(-2) (0.6-3.6 mg kg(-1) food) in the examined coatings. The determined amounts account for about 50% of the total migrate below 1000 Da.

Migration from can coatings: Part 3. Synthesis, identification and quantification of migrating epoxy-based substances below 1000 Da

Bisphenol A-derived glycidyl ethers as well as its reaction products with other lacquer components can migrate into the packed food from epoxy-based can coatings. A sensitive and selective method is presented using high-performance liquid chromatography coupled with ultraviolet light, fluorescence and electrospray ionization-mass selective detection for the identification and quantification of all migrants with a bisphenol A backbone and a molecular weight below 1000 Da, an estimated boundary for the absorption in the gastrointestinal tract. The identification of migrants was confirmed by microreactions of technical bisphenol A diglycidyl ether with solvents and phenols, which provided the fragmentation pattern of the mass selective detection and relative retentions of 42 different bisphenol A-related substances. It was shown by calibration of different isolated and synthesized bisphenol A derivatives that the fluorescence response relies on the amount of bisphenol A moiety in the respective molecule. Therefore, all migrating bisphenol A-related substances below 1000 Da were determined as bisphenol A diglycidyl ether equivalents using a calibration (fluorescence detection) of the commercially available bisphenol A diglycidyl ether monomer. The limit of quantification was set at 5 microg bisphenol A diglycidyl ether equivalents kg(-1) (or 0.8 microg dm(-2)). This method was validated for epoxy coatings (0.1 microg dm(-2) limit of detection and 24 microg bisphenol A-related substances below 1000 Da dm(-2) standard deviation, corresponding to 4.4% relative standard deviation). The quantification could be extended by combining the fluorescence response and structural information gained from the mass spectra, which provides more accurate results for each migrant. The calculation is based on the calibration of the bisphenol A chromophore content of the molecule. According to this method, the amount of migrating bisphenol A-related substances below 1000 Da in the acetonitrile extract (assuming a worst case) varied from about 0.4 to 0.7 mg dm(-2) in the examined coatings. The determined amounts comply with about 50% of the total migrate below 1000 Da.

[Tick bites and borreliosis in children attending forest kindergarten: a challenge for prevention]

AIM

The aim of this study was to analyse the influence of preventive measures on the risk of being bitten by a tick and of suffering from borreliosis in children attending so-called 'forest kindergartens' (nurseries located in forested areas where children spend all-season full-time outdoors), compared to children attending regular kindergartens. In addition, we aimed to analyse sources of information and the risk of being bitten more than once.

METHODS

53 kindergartens (25 forest kindergartens, 28 regular kindergartens) in the state of Baden-Württemberg, Germany participated in this study and protective parental behaviour was recorded. In a prospective cohort study, the numbers of tick bites and cases of borreliosis were recorded monthly (March to October 2004) using a questionnaire. The influence of preventive measures was estimated using multivariate log-binomial regression.

RESULTS

Altogether, 1707 children of 'forest kindergartens' (506 children) and regular kindergartens (1201 children) were included. Parental protective behaviour was significantly better in forest kindergartens compared to regular kindergartens. There were no substantial differences between effect estimates after stratification for parental protective behaviour. For children attending a 'forest kindergarten, the adjusted risk ratio of being tick bitten was 2.6 (3.3-3.0) which was only slightly different from the unadjusted risk, ratio.

CONCLUSION

Although protective parental behaviour in 'forest kindergarten' children was significantly better compared to regular kindergarten, children in forest kindergartens are at a considerable risk of tick bites and borreliosis. Implementing effective preventive measures against borreliosis represents a public health challenge.

Effect of ethanol on cardiac single sodium channel gating

Alcohol in modest and higher doses has the potential to induce cardiac arrhythmias. The most famous alcohol-related arrhythmia is the "holiday heart syndrome". Furthermore, there is a clear association between excessive alcohol consumption and the risk of sudden cardiac death. However, the acute effects of ethanol on arrhythmia induction are not well understood. The effect of ethanol on single cardiac sodium channels has not been studied yet. To elucidate the effect of ethanol on human cardiac sodium channels we performed a patch clamp study in HEK-293 cells overexpressing the human cardiac sodium channel. We used HEK-293 cells overexpressing the human cardiac sodium channel (Na(1.5)). Single channel gating was investigated by the cell-attached patch clamp technique. Sodium channel currents were elicited by depolarizing pulses from -120 to -20mV for a duration of 150ms. Single channel availability, open probability and peak average current were assessed baseline and after addition of ethanol in increasing concentrations (0.50 per thousand (10.9mM), 1.00 per thousand (21.7mM), 2.00 per thousand (43.5mM) and 4.00 per thousand (87.0mM)). We found a concentration-dependent reduction of open probability which was statistically significant at 2.00 per thousand ethanol (66.5+/-14% of control). At higher concentrations (4.00 per thousand) also availability decreased to 66.5+/-11.0% of control. This resulted in a significant decrease of peak average current at 2.00 per thousand and at 4.00 per thousand ethanol (61.8+/-7.4 and 53.0+/-8.2% of control). For the first time the present study demonstrates acute inhibitory effects of ethanol on single cardiac sodium channel gating and provides one potential mechanism for the well known clinical observation that ethanol triggers supraventricular and ventricular arrhythmias.

Explaining variability in the relationship between antiretroviral adherence and HIV mutation accumulation

OBJECTIVES

Determining the relationship between antiretroviral adherence and resistance accumulation is important for the design and evaluation of adherence interventions. Our objective was to explain heterogeneity observed in this relationship.

METHODS

We first conducted a systematic review to locate published reports describing the relationship between adherence and resistance. We then used a validated computer simulation to simulate the patient populations in these reports, exploring the impact of changes in individual patient characteristics (age, CD4, viral load, prior antiretroviral experience) on the shape of the adherence-resistance (A-R) curve.

RESULTS

The search identified 493 titles, of which 3 contained relevant primary data and 2 had sufficient follow-up for inclusion (HOMER and REACH cohorts). When simulating HOMER, the A-R curve had a high peak with a greatly increased hazard ratio (HR) of accumulating mutations at partial compared to complete adherence (simulation, HR 2.9; HOMER, HR 2.7). When simulating REACH, the A-R curve had a shallow peak with a slightly increased hazard of accumulating mutations at partial adherence (simulation, HR 1.2; REACH, HR 1.4). This heterogeneity was primarily attributable to differences in antiretroviral experience between the cohorts.

CONCLUSIONS

Our computer simulation was able to explain much of the heterogeneity in observed A-R curves.

Chronic L-Arginine Supplementation Enhances Endurance Exercise Tolerance in Heart Failure Patients

The purpose of the study was to determine the potential beneficial effect of six weeks oral L-arginine supplementation (LAS) on endurance exercise, an important determinant of daily-life activity in patients with chronic stable heart failure (CHF). After an initial incremental maximal exercise test, CHF patients performed an identical thirty-minute interval endurance exercise test before and after six weeks with (L-arginine group; ARG) or without LAS (control group; CTL). Hemodynamic, respiratory, and metabolic parameters were determined at rest, during exercise, and during recovery. Mean heart rate decreased throughout exercise and recovery after LAS (- 8.2 +/- 1.4 b x min(-1); p = 0.003 and - 6.7 +/- 1.6 b x min(-1); p < 0.001, respectively), systemic blood pressure and respiratory parameters remaining unchanged. Resting L-argininaemia increased from 102 +/- 11 to 181 +/- 37 micromol x l(-1) (p < 0.004) and exercise-induced peak increase in plasma lactate was blunted after LAS (4.13 +/- 0.75 vs. 3.13 +/- 0.39 mmol x l(-1); p = 0.02). No significant change was observed in the control group. In heart failure patients, six weeks oral LAS enhances endurance exercise tolerance, reducing both heart rate and circulating lactates. This suggests that chronic LAS might be useful as a therapeutic adjuvant in order to improve the patient's physical fitness.

Complete genome sequence of Vibrio fischeri: a symbiotic bacterium with pathogenic congeners

Vibrio fischeri belongs to the Vibrionaceae, a large family of marine gamma-proteobacteria that includes several dozen species known to engage in a diversity of beneficial or pathogenic interactions with animal tissue. Among the small number of pathogenic Vibrio species that cause human diseases are Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus, the only members of the Vibrionaceae that have had their genome sequences reported. Nonpathogenic members of the genus Vibrio, including a number of beneficial symbionts, make up the majority of the Vibrionaceae, but none of these species has been similarly examined. Here we report the genome sequence of V. fischeri ES114, which enters into a mutualistic symbiosis in the light organ of the bobtail squid, Euprymna scolopes. Analysis of this sequence has revealed surprising parallels with V. cholerae and other pathogens.

New multiple antigenic peptide-based enzyme immunoassay for detection of simian immunodeficiency virus infection in nonhuman primates and humans

Infections with human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2, respectively) are zoonotic infections. In Africa, the potential exists for additional cross-species transmissions from at least 33 different species of simian immunodeficiency virus (SIV)-infected nonhuman primates (NHPs) through hunting and butchering of these animals for food. Here we describe a highly sensitive and specific enzyme immunoassay (EIA) with chemically modified, multiple antigenic peptides (MAPs) developed for the detection and discrimination of antibodies to SIV genetic lineages. The SIV EIA was developed by using a comprehensive array of MAPs covering two envelope gene regions from all of the SIV lineages for which env sequences were available. Assay sensitivity was evaluated by using 63 plasma or serum samples obtained from primates naturally or experimentally infected with SIVs from 10 genetic lineages. Assay specificity was determined by using 97 known SIV-negative plasma specimens from these same species. Also used in the evaluations were 369 human samples: 198 HIV seronegative, 170 HIV-1 and/or HIV-2 seropositive, and 1 from a human SIVsm infection. Overall assay sensitivity and specificity were 100% with both immunodominant region (IDR) and V3 region MAPs. Although SIV env sequences from talapoin monkeys were not available for specific MAP inclusion, 5 (100%) of 5 SIVtal-infected samples were detected through cross-reactivity with other SIV IDR MAPs used in the assay. The one human SIVsm infection was identified. In conclusion, our SIV MAP EIA proved to be highly sensitive and specific for detecting SIV infections in NHPs and humans. As shown with SIV-infected talapoin monkeys, this assay has the potential to detect previously unidentified SIV strains and should be suitable for sentinel surveillance for potential new cross-species transmissions of SIVs to humans.