Search

Inadequate feeding practices contribute to poor nutrition among Peruvian children. In response, Peru's Lambayeque Regional Government funded an initiative in its four poorest districts to improve nutrition counselling skills of health-service professionals (HP). The study aimed to identify factors associated with successful communication of optimal nutrition practices to caregivers. Counselling data were collected in six health establishments in two of the four poorest Lambayeque districts. A thematic content analysis was completed for 30 direct observations of counselling by staff in the national child growth and development monitoring programme, 26 exit interviews with caregivers, 12 in-depth interviews (5 HP and 7 caregivers), and 5 home observations. Type and training of HP influenced messages given. Nurses focussed on multi-micronutrient powders and iron-rich foods; nutritionists targeted dietary diversity, food consistency, and frequency of feedings. Caregivers reported feeling more comfortable when HP used positive verbal communication and non-verbal cues. Language was a barrier (non-Quechua speaking HP), as were high HP turnover, remoteness of villages, and limited attending hours, all of which reduced opportunities for nutrition education. Learning materials and group demonstrations facilitated comprehension, but cultural beliefs prevented the adoption of some messages. Both HP and caregivers were invested in improving infant and young child feeding practices. Trained HP demonstrated skills for effective nutrition counselling. Inclusion of nutrition education and counselling training in all HP's curriculum, as well as in-service refresher training, is recommended to ensure all HP possess the knowledge and communication skills needed in the health services. [ABSTRACT FROM AUTHOR]

Objectives: Little is known about cardiac hemodynamics in the fetus with transposition of the great arteries and intact ventricular septum (TGA‐IVS). Better understanding of the fetal physiology in TGA‐IVS would help to provide insights into specific clinical complications observed after birth, in particular neonatal hypoxia and pulmonary hypertension. The aim of this study was to assess cardiac hemodynamics in fetuses with TGA‐IVS by performing systematic longitudinal echocardiographic follow‐up from diagnosis to delivery. Methods: This was a longitudinal retrospective study of fetuses referred between 2010 and 2018 to the Sainte‐Justine University Hospital Centre. Complete assessment of cardiac hemodynamics was performed in fetuses with TGA‐IVS at 18–22, 28–32 and 35–38 weeks' gestation, which were compared with normal fetuses matched for gestational age. The maximum diameter of the foramen ovale was measured using two‐dimensional echocardiography under the guidance of color Doppler echocardiography. Fetal cardiac hemodynamics were analyzed according to postnatal preductal transcutaneous oxygen saturation (TcSO2) < 65% or ≥ 65%, as a neonatal outcome, in fetuses with TGA‐IVS. Results: In total, 59 fetuses with TGA‐IVS and 160 normal fetuses were included. Global cardiac output was significantly higher in fetuses with TGA‐IVS than in controls, mainly owing to higher global pulmonary output, while global systemic cardiac output did not differ between TGA‐IVS fetuses and controls throughout pregnancy. Aortic flow (right ventricular output in fetuses with TGA‐IVS, left ventricular output in controls) was significantly higher in fetuses with TGA‐IVS than in normal fetuses. Ductal flow was significantly lower in fetuses with TGA‐IVS at every timepoint, and this difference increased considerably after 28–32 weeks. In parallel, the diameter of the foramen ovale was significantly smaller in fetuses with TGA‐IVS at 28–32 and 35–38 weeks, with a stagnation in growth after 28 weeks, compared with continuous growth in normal fetuses. Most of these cardiac hemodynamic anomalies in fetuses with TGA‐IVS were already present at 18–22 weeks, and the differences became greater at 28–32 weeks' gestation. TGA‐IVS neonates with TcSO2 < 65% had lower fetal left ventricular output, higher diastolic ductal retrograde flow and smaller foramen ovale at 28–32 weeks, compared with fetal values in those with postnatal TcSO2 ≥ 65%. Conclusions: Compared with normal fetuses, those with TGA‐IVS undergo a complex redistribution of blood flow during the second half of pregnancy, with higher global pulmonary flow, lower ductal flow (with negative diastolic flow at the end of pregnancy) and a smaller foramen ovale. In addition, fetal cardiac hemodynamic anomalies observed at 28–32 weeks' gestation were associated with lower postnatal TcSO2. These observations may provide a better understanding of premature closure of the foramen ovale and postnatal hypoxia that are specific to TGA‐IVS physiology. © 2019 International Society of Ultrasound in Obstetrics and Gynecology [ABSTRACT FROM AUTHOR]

Atmospheric physics is represented in numerical models by parameterizations that use resolved‐scale information to estimate the effects of physical processes on the atmospheric state. Over time, our understanding of these processes improves, new techniques are introduced to represent physics in a numerical model, and increased resolution changes the relative importance of different parameterizations within the system. As a result, the physical parameterization packages of numerical weather prediction (NWP) models undergo regular updates as older schemes are replaced with newer ones that offer an improved, and often more complex, depiction of relevant physical processes. Such changes are typically combined with a rebalancing of the physics suite because of strong interactions between parameterization schemes and the presence of compensating errors in the system. In this study, a major update to the package of physical parameterizations used in Canadian operational NWP is introduced. The primary goals of this effort were to improve the global energy budget and to facilitate an increase in the vertical resolution of operational configurations. Both of these objectives were achieved, along with a significant improvement in guidance quality for global and regional prediction systems. Key Points: An updated suite of parameterizations for atmospheric physics is developed for Canadian NWPRepresentation of the global energy budget is improved in the model climatologySignificant improvements in guidance quality are seen in upper‐air, surface, and precipitation scores [ABSTRACT FROM AUTHOR]

The article discusses the Observing System Research and Predictability Experiment (THORPEX), a global research program built to improve the accuracy of high-impact weather predictions, and mentions the science of prediction. Topics include various subprograms of the THORPEX Science Plan, like predictability and dynamical processes (PDP), the development of an interactive forecast system, and aspects of high-impact weather systems.

Rationale 18F- FDG- PET/ CT has a potential role in the early detection of haemophilic arthritis, at a time when treatment may still avoid further joint degeneration. The purposes of this pilot study were to determine the ability of 18F- FDG- PET/ CT to detect inflammatory changes associated with blood-induced arthropathy in knees of a rabbit model. Methods Ten juvenile rabbits were imaged at baseline and weeks 5 and 17 post intraarticular autologous blood injections ( ABI). Five rabbits in group 1 (G1) had ABI into the same knee joint every 2 weeks (total, eight injections). Five rabbits in group 2 (G2) had only two injections into the same knee, at weeks 5 and 17. Images were assessed visually and semi-quantitatively by measuring maximal standardized uptake values ( SUVmax) and standardized uptake ratio ( SUR = SUVmax in affected knee/ SUVmax in non-affected knee). Results More rabbits in G1 than G2 presented with positive chronic inflammatory synovial scores at week 17. Mean iron staining scores in injected knees were greater for G1 than for G2 ( P = 0.049). No increased uptake was identified in the injected knees in any of the rabbits at baseline or at week 5. At week 17, all G1 rabbits demonstrated increased uptake in their affected knees with higher mean SUVmax (1.5) than normal knees (1.0) ( P < 0.02). None of the G2 rabbits showed asymmetric increased uptake. The SUR of G1 was higher at week 17 compared to baseline ( P < 0.01) and week 5 ( P < 0.01). The SUR at week 17 was higher for G1 than for G2 (1.13) rabbits ( P < 0.01). Conclusion 18F- FDG- PET is able to detect the inflammatory changes associated with haemophilic arthropathy in this experimental model. [ABSTRACT FROM AUTHOR]

SUMMARY A class of axisymmetric horizontal flows dominated by strong heat or mass sources are considered here, which systematically arise in multiscale atmospheric and oceanic flows in various spatiotemporal scales such as hurricane embryos. Various linear and nonlinear analytical solutions are proposed, and several examples are given to illustrate them. On the basis of the proposed exact solutions, stability of the flow under various conditions is examined. The proposed exact solutions serve as benchmarks for validation of numerical models. A Chebyshev pseudospectral model is also developed for these flows. The numerical results are compared with the developed analytical solutions as well as a high-resolution numerical solution, which showed an excellent performance of the numerical model in terms of numerical diffusion and oscillation. The numerical method is also efficient because expensive calculations such as LU decomposition are only needed once, at the beginning of calculations. The model could be used in studying small-scale and multiple-scale phenomena such as hot towers and hurricane embryos, which are the subject of future studies. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Summary: We compared the distribution of vertebral fractures in adults and children and found that fractures occurred in different locations in the two age groups. This likely relates to the different shape of the immature spine. Introduction: We hypothesized that the anatomical distribution of vertebral fractures (VF) would be different in children compared to adults. Methods: We compared the distribution of VF defined using the Genant semi-quantitative method (GSQ method) in adults ( N = 221; 545 fractures) and in children early in the course of glucocorticoid therapy ( N = 44; 94 fractures). Results: The average age in the adult cohort was 62.9 years (standard deviation (SD), 13.4 years), 26% was male, the mean lumbar spine Z-score was −1.0 (SD, 1.5), and the corresponding T-score was −2.4 (SD, 1.4). The pediatric cohort median age was 7.7 years (range, 2.1-16.6 years), the mean lumbar spine Z-score was −1.7 (SD, 1.5), 52% was male, and disease categories were acute lymphoblastic leukemia (66%), rheumatological conditions (21%), and nephrotic syndrome (14%). The VF distribution was biphasic in both populations, but the peaks differed in location. In adults, the peaks were at T7/T8 and at T12/L1. In children, the focus was higher in the thoracic spine, at T6/T7, and lower in the lumbar spine, at L1/L2. When children were assessed in two age-defined sub-groups, a biphasic VF distribution was seen in both, but the upward shift of the thoracic focus to T6 was observed only in the older group, with the highest rates of fracture present between ages 7 and 10 years. Conclusions: These results suggest that the anatomical distribution of VF differs between children and adults, perhaps relating to the different shape of the immature spine, notably the changing ratio of kyphosis to lordosis. [ABSTRACT FROM AUTHOR]

Using knockout and transgenic technology, genetically modified animal models allowed us to understand the role of glucagon signalling in metabolism. Mice with a global deletion of the glucagon receptor gene (Gcgr) were designed using gene targeting. The phenotype of Gcgr−/−mouse provided important clues about the role of Gcgr in foetal growth, pancreatic development and glucose and lipid homeostasis. The lack of Gcgr activation was associated with: (i) hypoglycaemic pregnancies, poor foetal growth and increased foetal-neonatal demise; (ii) altered cytoarchitecture of pancreatic islets; (iii) altered glucose, lipid and hormonal milieu; (iv) reduced gastric emptying; (v) altered body composition and protection from diet-induced obesity; (vi) altered energy state; (vii) impaired hepatocyte survival; (viii) altered metabolic response to prolonged fasting and exercise and (ix) prevented development of diabetes in insulin-deficient mice. In contrast, mice overexpressing the Gcgr on pancreatic β-cells displayed an increase insulin secretion, pancreatic insulin content and β-cell mass, and partially protected against hyperglycaemia and impaired glucose tolerance when fed a high-fat diet. These findings suggest that glucagon signalling plays a significant role in the regulation of glucose and lipid homeostasis. Treatment options designed to block Gcgr activation may have negative implications in the treatment of diabetes. [ABSTRACT FROM AUTHOR]

We investigated the possibility of performing electroretinography (ERG) in non-pharmacologically dilated eyes using brighter flash (time-integrated) luminance. Photopic ( N = 26; background 25.5 cd·m, white LED flashes) and scotopic ERG ( N = 23, green LED flashes) luminance response functions were obtained simultaneously in a dilated (DE) and non-dilated eye (NDE). In the NDE, photopic V b-wave amplitude was reduced by 14% ( P < 0.0001), implicit time prolonged ( P < 0.0001), and retinal sensitivity (log K) decreased by 0.38 log units ( P < 0.0001) with no effect on a-wave. Using a xenon strobe light ( N = 6) to increase flash luminance, V remained lower by about 12% in the NDE ( P = 0.02). V with LED and xenon was achieved at 3.9 ± 1.0 cd·s·m and 3.3 ± 0.81 cd·s·m in the DE and 10.6 ± 1.2 cd·s·m and 12.3 ± 1.90 cd·s·m in the NDE, that is an increase of 0.43 and 0.57 log unit ( P < 0.0001), respectively. Increasing background luminance by 0.50 log units (80 cd·m, N = 4) resulted in implicit time normalization but not V amplitude. Rod V was decreased by 7% in NDE ( P < 0.05) and sensitivity reduced by 0.40 log units ( P < 0.0001), but our data suggest that the luminance may have not been sufficient to reach V in all participants in the NDE and that the sensitivity change may have been due to an inadequate inter-stimulus interval. For the photopic ERG, increasing flash luminance is not sufficient to compensate for the smaller pupil size, whereas for the scotopic ERG, more data are needed to establish proper inter-stimulus interval to perform recordings in a non-pharmacologically dilated. [ABSTRACT FROM AUTHOR]

The 2010 Winter Olympic and Paralympic Games took place in Vancouver, British Columbia, Canada, on 12--28 February and 12--21 March 2010, respectively. Weather forecasting presents specific challenges at the various Olympic venues, which are located in complex coastal terrain and are often characterized by tricky weather conditions, such as high winds, low visibility, and rapidly varying precipitation types and intensity. In addition to its current operational products, and in order to provide the best possible guidance and support to the Olympic Forecast Team, Environment Canada has developed several experimental numerical weather prediction systems for the games. These include 1) a regional ensemble prediction system (REPS), 2) high-resolution numerical modeling (down to 1-km horizontal grid spacing), and 3) surface modeling at the microscales (100-m grid spacing). The REPS is based on the limited-area version of the Global Environmental Multiscale model (GEM-LAM), with 20 members at 33-km horizontal grid spacing. The high-resolution models include 2.5- and 1-km grid-spacing configurations of the GEM-LAM, with improved cloud microphysics, geophysical fields, and radiation and cloud--radiation interactions. Finally, two innovative approaches are used to adapt and refine forecasts locally and to better predict surface characteristics, such as snow conditions and near-surface air temperatures. A microscale 2D surface system covers the Olympic venues with forcing from the operational regional and global models. Based on a similar strategy, a single-point model uses surface observations as forcing. The configurations of these experimental numerical weather prediction systems are described, together with some examples and verification results from the winters of 2008 and 2009 using the enhanced mesoscale observing network recently set up for the Olympics. [ABSTRACT FROM AUTHOR]

The light/dark cycle is the most important circadian clock synchronizer for mammals and humans. Circadian rhythms of dopamine and melatonin production in the retina have been reported to follow the light and dark cycle, but their impact on rod and cone functioning is not clear. The purpose of this study was to assess diurnal variations (morning vs. evening) in retinal function as measured with the photopic and scotopic electroretinogram (ERG). We also tried to correlate our results with the presence or absence of melatonin secretion in the saliva. Photopic and scotopic luminance–response functions were obtained in 29 participants at 11:00 (when melatonin should not be present) and 23:00 (when melatonin should be present). From the luminance–response function, Vmax, log K and slope parameters were derived. In scotopic condition, a significant increase of 6% in Vmax amplitude was observed in evening compared to morning ( P = 0.03) along with a prolonged b-wave implicit time of 8% ( P = 0.01) and an increase in rod sensitivity in evening compared to morning ( P = 0.02). As expected, these changes in rod function were accompanied by a higher concentration of melatonin in saliva samples in the evening ( P = 0.01). In photopic condition, only a prolonged a-wave implicit time of 5% was observed in evening when compared to morning ( P = 0.02). Our findings suggest that the rod system is favored during night time, when circulating melatonin is present. Although statistically significant changes were observed, the day vs. night difference observed in the present study appears to be too small to impact significantly upon clinical assessment of retinal function. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Physics is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Under normal physiological conditions, glucagon signalling is important in glucose homeostasis. Hyperglucagonaemia or altered insulin:glucagon ratio plays a role in maintaining hyperglycaemia in subjects with type 2 diabetes. It has been reported that glucagon receptor knockout ( Gcgr −/−) mice develop normally and have lower plasma glucose on a normal diet. The goal of the current research was to further investigate the role of glucagon signalling in metabolic control and glucose homeostasis. Gcgr −/− mice were challenged with a high-fat diet (HFD) and with streptozotocin, which induces beta cell damage. They were then analysed for whole-body and serum metabolic phenotypes as well as pancreatic islet morphology. In comparison with wild-type mice, Gcgr −/− mice exhibited decreased body weight and food intake, reduced plasma glucose levels, and improved oral and intraperitoneal glucose tolerance. Elevated glucagon-like peptide-1 levels and reduced gastric emptying were also observed in Gcgr −/− mice, which also had reduced HFD-induced hyperinsulinaemia and hyperleptinaemia, and were resistant to the development of hepatic steatosis. In addition, Gcgr −/− mice were resistant to STZ-induced hyperglycaemia and pancreatic beta cell destruction. This study demonstrates that blocking glucagon signalling by targeted Gcgr gene deletion leads to an improvement in metabolic control in this mouse model. [ABSTRACT FROM AUTHOR]

The retina is among the most metabolically active tissues in the body, requiring a constant supply of blood glucose to sustain function. We assessed the impact of low blood glucose on the vision of C57BL/6J mice rendered hypoglycemic by a null mutation of the glucagon receptor gene, Gcgr. Metabolic stress from moderate hypoglycemia led to late-onset loss of retinal function in Gcgr-/- mice, loss of visual acuity, and eventual death of retinal cells. Retinal function measured by the electroretinogram b-wave threshold declined >100-fold from age 9 to 13 months, whereas decreases in photoreceptor function measured by the ERG a-wave were delayed by 3 months. At 10 months of age Gcgr-/- mice began to lose visual acuity and exhibit changes in retinal anatomy, including an increase in cell death that was initially more pronounced in the inner retina. Decreases in retinal function and visual acuity correlated directly with the degree of hypoglycemia. This work demonstrates a metabolic-stress-induced loss of vision in mammals, which has not been described previously. Linkage between low blood glucose and loss of vision in mice may highlight the importance for glycemic control in diabetics and retinal diseases related to metabolic stress as macular degeneration. [ABSTRACT FROM AUTHOR]

This paper introduces the three-dimensional Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), which treats atmospheric dynamics, radiation, and chemistry interactively for the height range from the earth’s surface to the thermosphere (approximately 250 km). It is based on the latest version of the ECHAM atmospheric general circulation model of the Max Planck Institute for Meteorology in Hamburg, Germany, which is extended to include important radiative and dynamical processes of the upper atmosphere and is coupled to a chemistry module containing 48 compounds. The model is applied to study the effects of natural and anthropogenic climate forcing on the atmosphere, represented, on the one hand, by the 11-yr solar cycle and, on the other hand, by a doubling of the present-day concentration of carbon dioxide. The numerical experiments are analyzed with the focus on the effects on temperature and chemical composition in the mesopause region. Results include a temperature response to the solar cycle by 2 to 10 K in the mesopause region with the largest values occurring slightly above the summer mesopause. Ozone in the secondary maximum increases by up to 20% for solar maximum conditions. Changes in winds are in general small. In the case of a doubling of carbon dioxide the simulation indicates a cooling of the atmosphere everywhere above the tropopause but by the smallest values around the mesopause. It is shown that the temperature response up to the mesopause is strongly influenced by changes in dynamics. During Northern Hemisphere summer, dynamical processes alone would lead to an almost global warming of up to 3 K in the uppermost mesosphere. [ABSTRACT FROM AUTHOR]

Background: The goal of this study was to evaluate the accuracy of computerized tomography (CT) and 99mTc-white blood cell (WBC) scintigraphy versus colonoscopy in assessing inflammatory bowel diseases (IBD) in a large population of children.Methods: In a patient population of 313 consecutive children who had a 99mTc-WBC scan, 106 colonoscopies were done within a median time interval of 8 days of the 99mTc-WBC scan. One hundred and three CT scans were performed on 84 patients.Results: Of the 42 CT scans obtained within a short time interval after the 99mTc-WBC scan, 21 (50%) were normal. In the 21 children with a positive 99mTc-WBC scan, 62% (13/21) of the CT scans underestimated the bowel wall inflammation in at least one segment. In the children with a negative 99mTc-WBC study, there were 17 negative CT examinations and 4 examinations showing an abnormal terminal ileum. When CT was compared with colonoscopy in assessing inflammation, there were five true-negative CT, two true-positive CT, no false-positive, and seven false-negative CT examinations. When 99mTc-WBC scintigraphy was compared with colonoscopy in assessing inflammation, there were seven true-positive, two false-negative, five true-negative, and no false-positive 99mTc-WBC studies. The 99mTc-WBC scan was positive in five patients with a false-negative CT examination. Of the total 103 CT scans obtained, 53 (51%) were normal. Four abscesses (3.8%) were demonstrated by CT.Conclusions: 99mTc-WBC scintigraphy is more sensitive than CT for detecting inflammation of the bowel wall. The incidence of complications from IBD in this retrospective study was much lower than had been previously reported. [ABSTRACT FROM AUTHOR]

Background: A significant percentage of children newly diagnosed with acute lymphoblastic leukemia (ALL) present with vertebral fracture(s). In the pan-Canadian Steroid Induced Osteoporosis in Pediatric Populations (STOPP) study, a longitudinal natural history of ALL, 17% of children presented with at least a single lumbar fracture at diagnosis. Understanding the influences on bone fragility early in the disease process would have significant benefit when coordinating care for children when initiating treatment. Methods: We examined data taken around the time of diagnosis of 188 children (ages 2.5 to 16.9) newly diagnosed with ALL. We compared 29 children with vertebral fractures (mean age 6.49 (4.08)) to those 157 (7.15 (3.85)) without vertebral fractures. Measures included areal BMD (DEXA), fractures (x-ray), Tanner stage, (from pictures), pain (self-report), nutrition (7 day recall) and activity from the HAES. Gluccocorticoid (GC) exposure was derived from clinical records. Results: Analyses of variance found NSD between the two groups in age, gender, Tanner stage, Ca intake or VitD intake (both %RDA), inactive hours, change in activity from pre-illness levels, GC exposure by mass or surface area, ALL risk classification, or duration from symptom onset until diagnosis. The non-fracture group had significantly higher (p<.002) lumbar BMDa z-scores. The fracture group reported significantly more back pain (p<.001) and significantly (p<.02) more somewhat active hours (walking, etc.) in the two weeks prior to assessment. Poisson regression analysis (Likelihood Ratio Chi-Square value = 132.768, p=0.001) demonstrated a significantly elevated risk of fractures with decreased BMDa Z-scores (p<.001) and increased age (p<.02), BMI z-score (p<.001), pain (p<.004), and total weekly somewhat active hours (p<.001). No other variables had significant effects. Discussion: These results suggest that the older children in the STOPP study, with greater mass and greater durations of activity, appear to be at elevated risk of lumbar fractures at diagnosis. For some children, the pathological effects of ALL on bone may lead to rapid increases in bone fragility. As a consequence stress from previously normal activity levels may be sufficient to provoke lumbar fractures. As high intensity activity is often suppressed in illness, attention to lower intensity weight-bearing activity is warranted. [ABSTRACT FROM AUTHOR]

We reviewed 312 (99m)Tc leukocyte (99m)Tc-WBC studies to evaluate the sensitivity and specificity of (99m)Tc-WBC for identifying small-bowel and gastric inflammation in children with Crohn's disease. The (99m)Tc-WBC scans were interpreted blindly and compared to the results of colonoscopy with biopsies and surgical specimens. In 46 children, total colonoscopy was done within a few days of a (99m)Tc- WBC scan and in 13 others surgical specimens were available. Of the 37 children in whom the terminal ileum was visualized endoscopically (24) or surgically (13), the WBC-Tc(99m) scan showed a similar degree of inflammation in 33. The sensitivity of (99m)Tc-WBC scanning was 91% and the specificity 96%. The scans allowed evaluation of inflammation in the terminal ileum in 22 children in whom the endoscopist did not cannulate it; the scans were abnormal in 10 of these 22 children. In the children with no ileoscopy the results of the (99m)Tc-WBC scan were consistent with the laboratory values, the gastroenterologist's clinical assessment, and long-term clinical follow-up. Finally, the scans of 46 controls did not reveal any false-positive findings in the terminal ileum. Five children with gastritis documented by gastroscopy had normal (99m)Tc-WBC scans and upper gastrointestinal barium studies. This study demonstrates in a large number of normal and abnormal children with different pre-test probabilities of having inflammatory bowel disease that scintigraphy is reliable in identifying small-bowel inflammation. [ABSTRACT FROM AUTHOR]

The mouse ob gene encodes leptin, an adipocyte hormone that regulates body weight and energy expenditure. Leptin has potent metabolic effects on fat and glucose metabolism. A mutation of the ob gene results in mice with severe hereditary obesity and diabetes that can be corrected by treatment with the hormone. In lean mice, leptin acutely increases glucose metabolism in an insulin-independent manner, which could account, at least in part, for some of the antidiabetic effect of the hormone. To investigate further the acute effect of leptin on glucose metabolism in insulin-resistant obese diabetic mice, leptin (40 ng x g(-1) x h(-1)) was administered intravenously for 6 h in C57Bl/6J ob/ob mice. Leptin increased glucose turnover and stimulated glucose uptake in brown adipose tissue (BAT), brain, and heart with no increase in heart rate. A slight increase in all splanchnic tissues was also noticed. Conversely, no increase in skeletal muscle or white adipose tissue (WAT) glucose uptake was observed. Plasma insulin concentration increased moderately but neither glucose, glucagon, thyroid hormones, growth hormone, nor IGF-1 levels were different from phosphate-buffered saline-infused C57Bl/6J ob/ob mice. In addition, leptin stimulated hepatic glucose production, which was associated with increased glucose-6-phosphatase activity. Conversely, PEPCK activity was rather diminished. Interestingly, hepatic insulin receptor substrate (IRS)1-associated phosphatidylinositol 3-kinase activity was slightly elevated, but neither the content of glucose transporter GLUT2 nor the phosphorylation state of the insulin receptor and IRS-1 were changed by acute leptin treatment. Hepatic lipid metabolism was not stimulated during the acute leptin infusion, since the content of triglycerides, glycerol, and citrate was unchanged. These findings suggest that in ob/ob mice, the antidiabetic antiobesity effect of leptin could be the result of a profound alteration of glucose metabolism in liver, BAT, heart, and consequently, glucose turnover. Insulin resistance of skeletal muscle and WAT, while not affected by acute leptin treatment, could also be corrected in the long term and account for some of leptin's antidiabetic effects. [ABSTRACT FROM AUTHOR]

The mechanisms underlying the increase in energy expenditure during leptin treatment are not clear. We recently showed that a 5-h intravenous or intracerebroventricular infusion of leptin elevated basal glucose uptake in skeletal muscle (SM) and brown adipose tissue and increased whole-body glucose turnover in C57Bl/6J mice (Kamohara S, Burcelin R, Halaas JL, Friedman JM, Charron MJ: Acute stimulation of glucose metabolism in mice by leptin treatment. Nature 389:374-377, 1997). We extended the previous study by measuring steady-state levels of uncoupling protein (UCP)-2 mRNA and UCP-3 mRNA in white adipose tissue (WAT) and SM. Leptin by intravenous or intracerebroventricular infusion for 5 h was associated with a decrease in UCP-2 mRNA in WAT (47-52%) and UCP-3 mRNA in SM (33-37%). Because overexpression of UCP-2 or UCP-3 can depolarize the inner mitochondrial membrane, suppression of UCP-2 mRNA and UCP-3 mRNA may in fact lower respiratory demands in WAT and SM. This is consistent with the parallel suppression of cytochrome oxidase subunit IV (COX-IV) mRNA in WAT (35-39%) after leptin infusion. COX-IV mRNA in SM did not respond to acute leptin treatment. Mitochondrial inorganic phosphate carrier (P1C) mRNA was also suppressed in WAT (33-35%) by either method of leptin infusion, but only intravenous infusion of leptin reduced P1C mRNA in SM (40%). Denervation suppressed mRNA levels for UCP-2 (49%), UCP-3 (36%), and COX-IV (59%) and eliminated the acute response to leptin in SM. The comparable response to leptin under intravenous or intracerebroventricular infusion and the loss of responsiveness after denervation strongly suggest that the acute effects of leptin involve central signaling pathways. [ABSTRACT FROM AUTHOR]

Background. Studies have suggested that scans with technetium-tagged white blood cells (WBC-Tc99m) may be equal to endoscopy in the assessment of extent and activity of inflammatory bowel disease (IBD). Objective. We have retrospectively examined the accuracy of WBC-Tc99m scans in differentiating continuous from discontinuous colitis in pediatric IBD. Materials and methods. There were 207 children in the study (96 boys, 111 girls, median age 13 years). This included 29 controls – children with no gastrointestinal disease (NL) who underwent WBC-Tc99m scans for other medical problems. Scans were obtained at 30 minutes and 2–4 hours following injection. Scans were interpreted as showing continuous colitis, discontinuous colitis, or no colitis. Results. In the 77 children with active Crohn's disease (CD) of the colon, the scans revealed discontinuous uptake in 63 children and continuous uptake in 14. In the 29 children with ulcerative colitis (UC), 23 scans showed continuous uptake and 6 revealed discontinuous uptake. Two of these 6 showed focal activity near the appendix, and subclinical appendicitis could not be excluded. Another child was bleeding and the scan could have been misinterpreted as showing small- bowel inflammation. In the last three patients, skip areas were clearly identifiable. In none of these last three patients were the biopsies typical of CD (i. e., no granuloma was identified) nor was inflammation patchy. In summary, of the 106 scans showing inflammation, 6 were classified into the wrong group. Conclusion. These data show that WBC-Tc99m scanning can be useful in distinguishing discontinuous from continuous colitis. [ABSTRACT FROM AUTHOR]

A set of criteria was developed to standardize assessment of DMSA renal scintigraphy which were performed to evaluate children for acute pyelonephritis and renal scarring. This study was undertaken to assess intra- and interobserver variability in the interpretation of DMSA renal scintigraphy using these criteria. Renal contours and parenchyma were assessed in three zones. Contours were assessed as normal or abnormal and parenchymal defects were evaluated in terms of character, shape and degree in three regions (upper and lower pole and midzone). Two nuclear medicine physicians blindly reviewed 57 DMSA scintigraphy on two occasions each. Disagreement of each observer's evaluation of the same scintigraphy on two different occasions was described as intraobserver variability, and the comparison between readings by each of the two observers was described as interobserver variability. High levels of intra- (95.9% and 90.6% respectively, p < 0.05) and interobserver agreement (84.4%, p < 0.05) were demonstrated. There were minor differences in inconsistencies between the two kidneys or different kidney zones. We conclude that standardization of criteria resulted in higher intra- and interobserver consistency in interpretation of DMSA scintigraphy. [ABSTRACT FROM AUTHOR]

Glucose transporters are a family of membrane proteins which mediate glucose uptake across the cell membrane. The facilitative glucose transporter proteins are products of unique genes and are expressed in a tissue-specific manner. They are very similar structurally, containing 12 putative membrane spanning domains. Functionally they vary in their affinity for glucose and sensitivity to hormones such as insulin. Glucose homeostasis depends mainly on controlled changes in glucose transport in insulin-responsive tissues such as skeletal muscle and adipose cells where both glucose transporter 1 and glucose transporter 4 are expressed. Glucose transporter 4 is the major glucose transporter in these tissues and translocates from an intracellular vesicle to the cell membrane in response to insulin. Alterations of the level of expression of these glucose transporters should result in changes in insulin sensitivity and modification of whole-body metabolism. To test these hypotheses transgenic mouse models have been generated which overexpress glucose transporters in specific tissues or in the whole body. Glucose transporter 1 and glucose transporter 4 have been overexpressed specifically in skeletal muscle and glucose transporter 4 specifically in adipose tissue. Mice have also been made which overexpress glucose transporter 4 in the whole body. Using homologous recombination technology to disrupt the glucose transporter 4 gene, a 'knockout' mouse has been created which expresses no glucose transporter 4. The metabolic consequences of these genetic manipulations on the level of expression of glucose transporters in the mouse are reviewed. The future applications of transgenic mouse technology in creating models which mimic human diseases are also discussed. [ABSTRACT FROM AUTHOR]

Investigates whether disruption of GLUT-4 gene in mice effects isometric and shortening contractile performance of dorsal flexor muscle. Role of the gene in glucose uptake during muscle contraction; Evidence for increased muscle fatigability in GLUT-4 deficient mice; Relationship between enhanced susceptibility to fatigue and decline in muscle carbohydrates.

An abstract of the conference paper "Identification of predictors of bone mineral density trajectories in pediatric Systemic Lupus Erythematosus patients," by E. D. Silverman, and colleagues, is presented.

We evaluated the sensitivity and specificity of Technetium-99m (99mTc)-white blood cell (WBC) for identifying terminal ileum inflammation in children with Crohn's disease (CD). In 40 children, total colonoscopy was done within a few days of a 99mTc-WBC scan carried out to evaluate the inflammation in children with CD. In 38 patients the intensity and the location of inflammation shown on the 99mTc-WBC scan of the colon were similar to the biopsy result of the colonoscopy. The sensitivity of the 99mTc-WBC scan was 97% in assessing colonic inflammation compared with colonoscopy. The 99mTc-WBC scan allowed evaluation of inflammation in the terminal ileum in 21 patients in whom the endoscopist did not cannulate the terminal ileum. Of the 19 patients in whom the terminal ileum was visualized endoscopically (14) or surgically (5), the 99mTc-WBC scan findings showed a similar degree of inflammation in 17. The 99mTc-WBC scan was abnormal in 10 of these 21 children in whom the gastroenterologist did not reach the terminal ileum. In these children with no ileoscopy the results of the 99mTc-WBC scan were consistent with the laboratory values, the gastroenterologist's clinical assessment and with long-term clinical follow-up. Finally, the 99mTc-WBC scan of 83 controls did not reveal any false-positive findings in the terminal ileum (colonoscopy result available in 30 controls). When total colonoscopy or ileoscopy is not performed or when contrast radiography is negative or unable to differentiate CD from lymphoid nodular hyperplasia, scintigraphy can demonstrate the presence of ileitis and/or colitis. [ABSTRACT FROM AUTHOR]