A METHOD TO IDENTIFY AND LOCALIZE A SINGLE HOT PARTICLE IN THE LUNGS USING AN ARRAY OF HIGH-PURITY GERMANIUM DETECTORS FOR IMPROVED ESTIMATE OF THE DEPOSITED ACTIVITY.

A new method has been developed to identify and localize a single hot particle in the lungs using an array of four high-purity germanium detectors. The method is based upon calculating a set of three count rate ratios (generated by each individual detector in the array) that are evaluated in sequence to designate whether the measured deposition can be associated with a hot particle rather than the default assumption of a uniform activity distribution. Identification and localization of the hot particle are determined from a single in vivo measurement in which detectors are positioned above and below the thorax. The method was tested using an anthropomorphic thorax phantom in which point sources of 241Am, 137Cs and 60Co were individually inserted in the lungs at 15 different locations and were measured using a scanning bed whole-body counter. Depending upon source location and photon energy, a bias of -35% up to +76% could be introduced by falsely assuming a uniform activity distribution in the lungs. This bias would directly translate to an erroneous dose estimate to the lungs. It was demonstrated that by using the appropriate detector efficiencies for the single hot particle, the bias associated with the activity determination is reduced to <10% and ~2% in average.

Implementation of a triage monitoring program for internal exposure to short-lived radionuclides in Israel-challenges and recommendations.

Monitoring internal exposure to short-lived radionuclides is challenging, due to the frequent measurements required. ISO Standard 16 637 and the Swiss Personal Dosimetry Ordinance describe a screening measurement (triage monitoring) conducted in the workplace to identify workers suspected of internal exposure. Based on a previous study that examined the feasibility of using several commonly found radiation monitors in Israel in a triage monitoring program, we conducted a pilot study towards the implementation of triage monitoring in nuclear medicine facilities in Israel. The pilot study was conducted while considering the current Israeli regulations and local safety culture. We implemented the triage monitoring program in three nuclear medicine facilities in Israel, with a total of 55 monitored workers. The pilot study consisted of two stages: a short-term stage conducted in the largest manufacture of radiopharmaceuticals in Israel and a long-term stage in two nuclear medicine departments in Israel. During the first stage of the study, participants were asked to conduct a daily measurement at the end of the workday and send a urine sample to the national internal dosimetry laboratory. The second stage lasted 5 months in a major hospital and 18 months in a regional hospital. The workers were asked to perform the measurement at the end of the shift and send a urine sample if a defined threshold had been crossed. The mean participation rate in the long-term stage (>70%) indicates that implementation of the triage monitoring program could be successful in Israel. Based on the findings of the study, practical recommendations are listed: suitable monitoring devices, allocating a monitoring location, time of measurement, training of the workers, record keeping and coordination with a certified dosimetry laboratory. The pilot study recommendations were submitted to the Israel Institute for Occupational Safety and Hygiene at the Ministry of Labor, Social Affairs and Social Services.

Home and neighbourhood built environment features in family-based treatment for childhood obesity.

BACKGROUND: Family-based behavioural weight loss treatment (FBT) for childhood obesity helps families develop strategies to facilitate healthy choices in their home and other environments (e.g. home neighbourhood). The current study examines how the home food environment, both pre-FBT and post-FBT, and the neighbourhoods in which families live are associated with child weight and weight-related outcomes in FBT. METHODS: Parent-child dyads (n = 181) completed a 16-session FBT programme and completed home environment, anthropometric and child dietary/activity assessments at pre-FBT and post-FBT. Parents reported on availability of food, electronics and physical activity equipment in the home. The neighbourhood food and recreation environments around each dyad's residence was characterized using existing data within a geographic information system. RESULTS: Families successfully made healthy home environment modifications during FBT. Regression models showed reducing RED (e.g. high-energy-dense and low-nutrient-dense) foods and electronics in the home during FBT had positive effects on child weight and weight-related outcomes. No neighbourhood food or recreation environment variables were significantly related to outcomes, although having a larger density of public recreation spaces was associated with increases in physical activity at the trend-level. CONCLUSIONS: Modifying the home environment, specifically reducing RED foods and electronics, may be particularly important for FBT success.

Delay discounting and utility for money or weight loss.

OBJECTIVE: Obesity is related to a bias towards smaller immediate over larger delayed rewards. This bias is typically examined by studying single commodity discounting. However, weight loss often involves choices among multiple commodities. To our knowledge, no research has examined delay discounting of delayed weight loss compared with other commodities. METHODS: We examined single commodity discounting of money and cross commodity discounting of money and weight loss in a sample of 84 adults with obesity or overweight statuses interested in weight loss. The exchange rate between money and weight loss was calculated, and participants completed two delay discounting tasks: money now versus money later and money now versus weight loss later. RESULTS: Participants discounted weight loss more than money (p < 0.001). When participants were divided into those who preferred weight loss (n = 61) versus money (n = 23), those who preferred money over weight loss discounted weight loss even more than individuals that preferred weight loss (p = 0.003). CONCLUSIONS: Greater discounting of weight loss for those who preferred money suggest that idiosyncratic preferences are related to multiple commodity discounting, and greater discounting of weight loss across all participants provide insight on important challenges for weight control.

AN ESTIMATION OF THE EXPOSURE OF THE POPULATION OF ISRAEL TO NATURAL SOURCES OF IONIZING RADIATION.

The radiation dose to the population of Israel due to exposure to natural sources of ionizing radiation was assessed. The main contributor to the dose is radon that accounts for 60% of the exposure to natural sources. The dose due to radon inhalation was assessed by combining the results of a radon survey in single-family houses with the results of a survey in apartments in multi-storey buildings. The average annual dose due to radon inhalation was found to be 1.2 mSv. The dose rate due to exposure to cosmic radiation was assessed using a code that calculates the dose rate at different heights above sea level, taking into account the solar cycle. The annual dose was calculated based on the fraction of time spent indoors and the attenuation provided by buildings and was found to be 0.2 mSv. The annual dose due to external exposure to the terrestrial radionuclides was similarly assessed. The indoor dose rate was calculated using a model that takes into account the concentrations of the natural radionuclides in building materials, the density and the thickness of the walls. The dose rate outdoors was calculated based on the concentrations of the natural radionuclides in different geological units in Israel as measured in an aerial survey and measurements above ground. The annual dose was found to be 0.2 mSv. Doses due to internal exposure other than exposure to radon were also calculated and were found to be 0.4 mSv. The overall annual exposure of the population of Israel to natural sources of ionizing radiation is therefore 2 mSv and ranges between 1.7 and 2.7 mSv.

Friends and social contexts as unshared environments: a discordant sibling analysis of obesity- and health-related behaviors in young adolescents.

OBJECTIVE: This study examines the contribution of best friends' weight and the peer social context (time spent alone versus with friends) as sources of unshared environment associated with variability in weight and health behaviors among weight-discordant siblings. METHODS: Pairs of same-sex biologic siblings (N=40 pairs; ages 13-17) were originally recruited as part of a study evaluating putative factors contributing to differences in adiposity among weight-discordant siblings. Siblings were asked to bring their best friends to the laboratory and siblings and friends' height and weight were objectively measured. Siblings also completed multi-pass dietary recalls to assess energy intake and sugar sweetened beverage (SSB) consumption. Siblings' physical activity was measured using accelerometry. Experience sampling methodology was used to assess sedentary behaviors/screen time and the number of occasions siblings spent alone and in the presence of friends. Multilevel models were used to estimate the relationships between predictors (best friends' zBMI, time spent alone or with friends) and outcomes (siblings' zBMI and obesity-related health behaviors). RESULTS: Best friends' zBMI was the best predictor of participants' zBMI, even when controlling for child's birth weight. Best friends' weight (zBMI) further predicted participants' SSB intake and time engaged in sedentary behaviors. Being active with friends was positively associated with participants' overall physical activity, whereas spending time alone was negatively associated with accelerometer counts regardless of siblings' adiposity. CONCLUSIONS: A friends' weight and the social context are unshared environmental factors associated with variability in adiposity among biologically-related weight-discordant siblings.

Two pathways of proton transfer reaction to (triphos)Cu(η(1)-BH4) via a dihydrogen bond [triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane].

The interaction of the η(1)-tetrahydroborate copper(i) complex (triphos)Cu(η(1)-BH4) () with proton donors [CF3CH2OH (TFE), (CF3)2CHOH (HFIP), (CF3)3COH (PFTB), PhOH, p-NO2C6H4OH (PNP), p-NO2C6H4N[double bond, length as m-dash]NC6H4OH (PNAP), CF3OH] was a subject of a combined IR spectroscopic and theoretical investigation. Spectral (Δν) and thermodynamic (ΔH) parameters of dihydrogen bond (DHB) formation were determined experimentally. The terminal hydride ligand (characterized by the basicity factor Ej(BH) = 0.87 ± 0.01) is found to be a site of proton transfer which begins with nucleophilic substitution of BH4(-) by the alcohol oxygen atom on the copper center (BH pathway). The activation barrier computed for (CF3)2CHOH in CH2Cl2 - ΔG = 20.6 kcal mol(-1) - is in good agreement with the experimental value (ΔG = 20.0 kcal mol(-1)). An abnormal dependence of the reaction rate on the proton donor strength found experimentally in dichloromethane is explained computationally on the basis of the variation of the structural and energetic details of this process with the proton donor strength. In the second reaction mechanism found (CuH pathway), DHB complexes with the initial ROH coordination to the bridging hydride lead to B-Hbr bond cleavage with BH3 elimination. "Copper assistance" via the CuO interaction is not involved. This mechanism can be evoked to explain the occurrence of proton transfer in coordinating solvents.

Radon concentrations in different types of dwellings in Israel.

The average radon concentration in Israeli dwellings was assessed by combining the results of a 2006 radon survey in single-family houses with the results of a 2011 radon survey in apartments of multistorey buildings. Both surveys were based on long-term measurements using CR-39 detectors. The survey in multistorey buildings was intended to assess the influence of recent practices in the local building industry on the radon concentrations. These practices include the use of building materials with higher concentrations of the natural radionuclides in the last 20 y than before, as well as the improvement in sealing techniques over that period. Another practice in place since the early 1990 s is the building of a shielded area in every apartment that is known as an RSS (residential secure space). The RSS is a room built from massive concrete walls, floor and ceiling that can be hermetically sealed and is intended to protect its residents from a missile attack. The influence of the above-mentioned features on radon concentrations was estimated by dividing the participating apartments into two groups: apartments in buildings >20 y, built using building materials with low concentrations of the natural radionuclides, regular sealing and without an RSS and apartments in buildings newer than 10 y, built using building materials with higher concentrations of the natural radionuclides, improved sealing and including an RSS. It was found that the average radon concentration in apartments in new buildings was significantly higher than in old buildings and the average radon concentration in single-family houses was significantly higher than in apartments in multistorey buildings. Doses due to indoor radon were estimated on the basis of the updated information included in the 2009 International Commission on Radiological Protection statement on radon.

Fidaxomicin, a new treatment for Clostridium difficile infections.

Clostridium difficile is currently the most important cause of infectious diarrhea in the United States. Fidaxomicin, a macrolide antibiotic, was recently approved for treatment of C. difficile infections (CDIs). In vitro studies demonstrate that fidaxomicin has a narrow spectrum of activity against C. difficile with minimal effect on the gut flora. Clinical trials indicate that fidaxomicin is as effective as vancomycin for treatment of CDI with fewer recurrences. Additionally, fidaxomicin has minimal systemic absorption with few adverse side effects. Thus, fidaxomicin is an attractive new alternative for treatment of CDI.

Sensitization of food reinforcement is related to weight status and baseline food reinforcement.

BACKGROUND: Food reinforcement is an empirical index of motivation to obtain food. Higher levels of food reinforcement are associated with increased energy intake and increased body weight. Food reinforcement can vary over repeated food presentations, as people may show reduced reinforcing value if they satiate to repeated reinforcers, or they may show sensitization, or an increase in reinforcing value with repeated presentations. Over the past few years, our laboratory has been studying the impact of repeated administration of large portions of high energy density snack foods on food reinforcement. We have shown in three separate studies that the majority of non-obese individuals become satiated after 2 weeks of the same snack food administration, but that a subset of obese individuals sensitize after this same manipulation. OBJECTIVE: The purpose of the study presented here was to identify predictors of reinforcer satiation or sensitization. SUBJECTS: For the analyses presented here, we combined data sets from three previous studies for a total of 67 adult participants. RESULTS: We found that higher body mass index (BMI) and higher baseline motivation to eat predicted sensitization, and baseline motivation to eat moderated the effects of BMI, such that higher baseline responding for food predicted sensitization in obese individuals, but satiation in non-obese individuals. CONCLUSIONS: These data suggest that repeated exposure to high energy density snack foods may result in sensitization to those foods, with similar effects as drugs of abuse in susceptible individuals, and that an individual's BMI and baseline responding act as predictors of this response.

Initial use of portable monitoring versus polysomnography to confirm obstructive sleep apnea in symptomatic patients: an economic decision model.

BACKGROUND: When using portable (level III and level IV) studies to "rule in" obstructive sleep apnea (OSA) in symptomatic patients, the pre-test probability (P) needs to be sufficiently high to minimize patients with negative tests who require full polysomnography. METHODS: We used a theoretical decision analysis model to assess the pre-test probability above which it would be appropriate to use portable studies to rule in disease in symptomatic patients with suspected OSA. For the base case, we considered a symptomatically sleepy patient referred with a probability of OSA of P. We determined the lower threshold of P appropriate for a clinical algorithm based upon an initial ambulatory study compared to initial diagnosis with PSG by comparing costs using the PSG algorithm with a diagnostic algorithm involving initial assessment with a portable study. RESULTS: In our base case, the pre-test probability above which portable testing would be less costly than initial diagnostic PSG would be 0.47. When an initial split night study was compared to portable testing, the pre-test probability above which portable testing was more economically attractive was greater (0.68). Values of P, however, varied considerably depending on values of many variables, including costs of diagnostic testing and CPAP compliance. CONCLUSIONS: Using a decision model, we have developed a theoretical framework to ascertain the pre-test disease probability above which portable studies would be economically attractive as an initial test in the assessment of patients with suspected OSA.

Phenomenology of prolonged febrile seizures: results of the FEBSTAT study.

BACKGROUND: Febrile status epilepticus (FSE) has been associated with hippocampal injury and subsequent mesial temporal sclerosis and temporal lobe epilepsy. However, little is known about the semiology of FSE. METHODS: A prospective, multicenter study of the consequences of FSE included children, aged 1 month through 5 years, presenting with a febrile seizure lasting 30 minutes or more. Procedures included neurologic history and examination and an MRI and EEG within 72 hours. All information related to seizure semiology was reviewed by three epileptologists blinded to MRI and EEG results and to subsequent outcome. Inter-rater reliability was assessed by the kappa statistic. RESULTS: Among 119 children, the median age was 1.3 years, the mean peak temperature was 103.2 degrees F, and seizures lasted a median of 68.0 minutes. Seizure duration followed a Weibull distribution with a shape parameter of 1.68. Seizures were continuous in 52% and behaviorally intermittent (without recovery in between) in 48%; most were partial (67%) and almost all (99%) were convulsive. In one third of cases, FSE was unrecognized in the emergency department. Of the 119 children, 86% had normal development, 24% had prior febrile seizures, and family history of febrile seizures in a first-degree relative was present in 25%. CONCLUSIONS: Febrile status epilepticus is usually focal and often not well recognized. It occurs in very young children and is usually the first febrile seizure. Seizures are typically very prolonged and the distribution of seizure durations suggests that the longer a seizure continues, the less likely it is to spontaneously stop.

Whole brain and localized magnetization transfer measurements are associated with cognitive impairment in patients infected with human immunodeficiency virus.

BACKGROUND AND PURPOSE: Patients infected with human immunodeficiency virus (HIV) are susceptible to cognitive deterioration. This study investigated the utility of magnetization transfer (MT) imaging for quantification of brain tissue alterations associated with cognitive deficits in patients with HIV. MATERIALS AND METHODS: MT ratios (MTR) were derived for whole brain and for regions of interest (ROIs) in the basal ganglia and white matter in 11 HIV and 12 control subjects. Relationships with severity of cognitive impairment and specific neuropsychological deficits were also evaluated. RESULTS: MTR values for normalized whole brain histogram peak height, whole brain histogram mean, and all examined ROIs were reduced in the HIV subjects. Normalized histogram peak height and mean for whole brain, as well as means for the corpus callosum, basal ganglia, and frontal white matter (FWM), were significantly correlated with severity of cognitive impairment. MTR values for white matter regions (corpus callosum, FWM, and centrum semiovale) were correlated with specific cognitive deficits. CONCLUSION: Quantitative MTR measurements, determined for the whole brain and for vulnerable ROIs, are sensitive to neuropathologic changes associated with cognitive impairment in HIV-infected patients.

Sewage and community shower drains are environmental reservoirs of Fusarium solani species complex group 1, a human and plant pathogen.

In two recent studies, clinical isolates in the Fusarium solani species complex (FSSC) were sequenced; one of the most common lineages was FSSC Group 1 (FSSC 1), a phylogenetic species that is synonymous with F. solani f. sp. cucurbitae race 2, a pathogen of cucurbit fruits. FSSC 1 was also identified in sink and shower drains in two hospitals. The environmental sources of FSSC 1 are important for understanding the epidemiology of both human and plant diseases caused by this organism. FSSC 1 was detected in sewage influent at all six tested urban wastewater treatment plants (WWTPs) in California with a concentration ranging from 75 to 413 colony-forming units (cfu) l(-1), a mean of 246 +/- 52 cfu l(-1) and a median of 254 cfu l(-1). During the treatment process, the concentration of FSSC 1 in the solid and liquid fractions diminished. FSSC 1 was detected in five and six of 14 community shower drains by culturing and polymerase chain reaction, respectively, whereas FSSC DNA was detected in all drains. FSSC accounted for 17 +/- 6% (n = 14) of the total fungal DNA in the drains. FSSC 1 was rarely isolated from post-harvest cucurbit fruits and was not found in cucurbit fields in California.

Biomarkers of HIV-1 CNS infection and injury.

While it is clear that HIV-1 can cause CNS dysfunction, current approaches to classification and diagnosis of this dysfunction rely on syndromic definitions or measures of abnormality on neuropsychological testing in the background context of HIV-1 infection. These definitions have been variably applied, offer only limited sensitivity or specificity, and do not easily distinguish active from static brain injury. Supplanting or augmenting these approaches with objective biologic measurements related to underlying disease processes would provide a major advance in classification, diagnosis, epidemiology, and treatment assessment. Two major avenues are now actively pursued to this end: 1) analysis of soluble molecular markers in CSF and, to a lesser degree, in blood, and 2) neuroimaging markers using anatomic, metabolic, and functional measurements. This review considers the rationale and prospects of these approaches.

Updated research nosology for HIV-associated neurocognitive disorders.

In 1991, the AIDS Task Force of the American Academy of Neurology published nomenclature and research case definitions to guide the diagnosis of neurologic manifestations of HIV-1 infection. Now, 16 years later, the National Institute of Mental Health and the National Institute of Neurological Diseases and Stroke have charged a working group to critically review the adequacy and utility of these definitional criteria and to identify aspects that require updating. This report represents a majority view, and unanimity was not reached on all points. It reviews our collective experience with HIV-associated neurocognitive disorders (HAND), particularly since the advent of highly active antiretroviral treatment, and their definitional criteria; discusses the impact of comorbidities; and suggests inclusion of the term asymptomatic neurocognitive impairment to categorize individuals with subclinical impairment. An algorithm is proposed to assist in standardized diagnostic classification of HAND.

Treatment options for type 2 diabetes in adolescents and youth: a study of the comparative efficacy of metformin alone or in combination with rosiglitazone or lifestyle intervention in adolescents with type 2 diabetes.

Despite the increased prevalence of type 2 diabetes mellitus (T2DM) in the pediatric population, there is limited information about the relative effectiveness of treatment approaches. This article describes the rationale and design of a National Institutes of Health-sponsored multi-site, randomized, parallel group clinical trial designed to test the hypothesis that aggressive reduction in insulin resistance early in the course of T2DM is beneficial for prolongation of glycemic control, as well as improvement in associated abnormalities and risk factors. Specifically, the trial compares treatment with metformin with two alternate approaches, one pharmacologic (combining metformin treatment with rosiglitazone) and one combining metformin with an intensive lifestyle intervention program. The Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study recruits 800 patients over a 4-yr period and follows them for a minimum of 2 yr and maximum of 6 yr. Patients are 10-17 yr of age, within 2 yr of diagnosis of diabetes at the time of randomization, lack evidence of autoimmunity, and have sustained C-peptide secretion. The primary outcome is time to loss of glycemic control, defined as a hemoglobin A1c >8% for 6 consecutive months. Secondary outcomes include the effect of the alternative treatments on insulin secretion and resistance, body composition, nutrition, physical activity and fitness, cardiovascular risk monitoring, microvascular complications, quality of life, depression, eating pathology, and resource utilization. TODAY is the first large-scale, systematic study of treatment effectiveness for T2DM in youth. When successfully completed, this study will provide critical new information regarding the natural history of T2DM in youth, the benefits of initiating early aggressive treatment in these patients, and the efficacy of delivering an intensive and sustained lifestyle intervention to children with T2DM.

Identification of Fusarium solani f. sp. cucurbitae Race 1 and Race 2 with PCR and Production of Disease-Free Pumpkin Seeds.

Fusarium solani f. sp. cucurbitae causes a fruit rot of cucurbits and is classified into two races that are actually distinct species: F. solani f. sp. cucurbitae race 1 (Fsc1) and race 2 (Fsc2). Because Fsc1 and Fsc2 are not easily distinguished morphologically, we developed a polymerase chain reaction (PCR) assay for rapid identification. Taxon-specific primers were designed from translation elongation factor 1-α sequences. Because clean seed is critical for disease control, we conducted experiments to determine if we could predict whether seed would be infected based on a visual rating of the fruit at harvest. In two trials in commercial pumpkin fields, eight fruit in each of four categories were selected: asymptomatic fruit, mildly infected fruit, severely infected fruit but without lesions extending into the seed cavity, and severely infected fruit with at least one lesion extending into the seed cavity. Isolates from both lesions and seed were identified as Fsc1 based on the PCR assay. No infected seed were recovered from fruit in which the surface was lesion-free or in which a lesion extended less than midway through the fruit flesh. Consequently, a rapid, visual inspection and exclusion of symptomatic fruit should be sufficient to obtain uninfected seed, even in infested fields.