Measurement of the whole body clearance of infused glycerol as a test of liver function after major hepatectomy.

Major liver resection can be used in the treatment of liver cancer. The functional capacity of liver parenchyma needs to be evaluated preoperatively because it conditions the outcome. We assessed whether the whole body clearance of glycerol, a substrate essentially metabolized in liver cells, may be suitable as a simple test of liver function. Seven patients after major hepatectomy, six patients after colectomy and 12 healthy subjects were studied. Patients were investigated on the first day after surgery. All participants were studied during a 150-min basal period followed by a 120-min infusion of 16 mumol kg-1 min-1 13C-labelled glycerol. Whole body glycerol clearance was calculated from the change in plasma glycerol concentration. Whole body glucose production was measured with 6,6 2H2 glucose infused as a tracer in the basal state and during glycerol infusion. In addition, 13C glucose synthesis was monitored to quantitate gluconeogenesis from glycerol. Patients after liver resection had higher plasma glycerol concentrations and lower whole body glycerol clearance than healthy subjects and patients after colectomy. They also had higher plasma glucagon concentrations. Their fasting glucose production was mildly elevated in the fasting state and did not change after glycerol infusion, indicating a normal hepatic autoregulation of glucose production. These results indicate that whole body glycerol clearance can be simply determined from plasma glycerol concentrations during exogenous glycerol infusion. It is significantly reduced in patients after major hepatectomy, suggesting that it constitutes a sensitive test of hepatic function. Its use as a preoperative testing procedure remains to be evaluated.

Effects of 2 different prior endurance exercises on whole-body fat oxidation kinetics: light vs. heavy exercise.

This study aimed to compare the effects of 2 different prior endurance exercises on subsequent whole-body fat oxidation kinetics. Fifteen men performed 2 identical submaximal incremental tests (Incr2) on a cycle ergometer after (i) a ∼40-min submaximal incremental test (Incr1) followed by a 90-min continuous exercise performed at 50% of maximal aerobic power-output and a 1-h rest period (Heavy); and (ii) Incr1 followed by a 2.5-h rest period (Light). Fat oxidation was measured using indirect calorimetry and plotted as a function of exercise intensity during Incr1 and Incr2. A sinusoidal equation, including 3 independent variables (dilatation, symmetry and translation), was used to characterize the fat oxidation kinetics and to determine the intensity (Fat(max)) that elicited the maximal fat oxidation (MFO) during Incr. After the Heavy and Light trials, Fat(max), MFO, and fat oxidation rates were significantly greater during Incr2 than Incr1 (p < 0.001). However, Δ (i.e., Incr2-Incr1) Fat(max), MFO, and fat oxidation rates were greater in the Heavy compared with the Light trial (p < 0.05). The fat oxidation kinetics during Incr2(Heavy) showed a greater dilatation and rightward asymmetry than Incr1(Heavy), whereas only a greater dilatation was observed in Incr2(Light) (p < 0.05). This study showed that although to a lesser extent in the Light trial, both prior exercise sessions led to an increase in Fat(max), MFO, and absolute fat oxidation rates during Incr2, inducing significant changes in the shape of the fat oxidation kinetics.

Health consultation : IBP Inc./tire chop facility targeted brownfields assessment, 1525 "O" Avenue, Fort Dodge, Webster County, Iowa (2007)

The Iowa Department of Natural Resources (IDNR) has requested the Iowa Department of Public Health (IDPH) Hazardous Waste Site Health Assessment Program to evaluate future health impacts of exposures at the formerly utilized IBP Inc./Tire Chop facility located at 1525 “O” Avenue, Fort Dodge, Iowa. This site has undergone a Targeted Brownfields Assessment conducted by the Contaminated Sites Section of the IDNR. This health consultation addresses potential health risks to people from future exposure to soil within the property boundary, and any health impacts resulting from contaminated groundwater beneath the site property from an evaluation of the data collected during the Targeted Brownfields Assessment. The information in this health consultation was current at the time of writing. Data that emerges later could alter this document’s conclusions and recommendations.

Free-breathing whole-heart coronary MRA with 3D radial SSFP and self-navigated image reconstruction.

Respiratory motion is a major source of artifacts in cardiac magnetic resonance imaging (MRI). Free-breathing techniques with pencil-beam navigators efficiently suppress respiratory motion and minimize the need for patient cooperation. However, the correlation between the measured navigator position and the actual position of the heart may be adversely affected by hysteretic effects, navigator position, and temporal delays between the navigators and the image acquisition. In addition, irregular breathing patterns during navigator-gated scanning may result in low scan efficiency and prolonged scan time. The purpose of this study was to develop and implement a self-navigated, free-breathing, whole-heart 3D coronary MRI technique that would overcome these shortcomings and improve the ease-of-use of coronary MRI. A signal synchronous with respiration was extracted directly from the echoes acquired for imaging, and the motion information was used for retrospective, rigid-body, through-plane motion correction. The images obtained from the self-navigated reconstruction were compared with the results from conventional, prospective, pencil-beam navigator tracking. Image quality was improved in phantom studies using self-navigation, while equivalent results were obtained with both techniques in preliminary in vivo studies.

Divergence and genetic variability among superior rubber tree genotypes

The objective of this work was to estimate the genetic variability and divergence among 22 superior rubber tree (Hevea sp.) genotypes of the IAC 400 series. Univariate and multivariate analyses were performed using eight quantitative traits (descriptors), including yield. In the univariate analyses, the estimated parameters were: genetic and environmental variances; genetic and environmental coefficients of variation; and the variation index. The Mahalanobis generalized distance, the Tocher agglomerative method and canonical variables were used for the multivariate analyses. In the univariate analyses, variability was verified among the genotypes for all the variables evaluated. The Tocher method grouped the genotypes into 11 clusters of dissimilarity. The first four canonical variables explained 87.93% of the cumulative variation. The highest genetic variability was found in rubber yield-related traits, which contributed the most to the genetic divergence. The most divergent pairs of genotypes are suggested for crossbreeding. The genotypes evaluated are suitable for breeding and may be used to continue the IAC rubber tree breeding program.

Cyanogenesis and the onset of tapping panel dryness in rubber tree

The objective of this work was to study the influence of cyanogenesis on the onset of irreversible tapping panel dryness (TPD) and the physiological and histological aspects of secondary phloem in the trunk (tapping panel) of rubber trees (Hevea spp.). Two cyanogenic compounds, linamarin and KCN, were applied separately on the trunk bark of healthy mature trees belonging to two Brazilian clones (Fx 4098 and Fx 3899). Changes in histology, latex pressure potential (ΨP) and cyanogenic potential (HCNp) were followed in the trunk inner barks. In addition, the HCNp levels were determined in TPD-affected plants of both clones. The applications of linamarin or KCN in healthy plants decreased latex ΨP, and formed tylosoids associated with in situ coagulation of latex. The clone Fx 4098 had the higher HCNp and showed the quicker and stronger responses to the cyanogenic compounds. Plants with TPD syntoms had a higher HCNp than the untreated healthy ones. Since histological changes are also structural markers of early TPD, it can be inferred that excessive release of cyanide can induce it in sensitive rubber clones

Assessment of rubber tree panels under crowns resistant to South American leaf blight

The objective of this work was to assess the performance of panel clones under crowns resistant to South American leaf blight (Microcyclus ulei). The experiment was carried out with 18 panel clones crown-budded with Hevea pauciflora x H. guianensis, in a Xanthic Ferralsol (Oxisol) in Manaus, AM, Brazil. The following parameters were evaluated: dry rubber yield, plant nutritional status, and anatomical and physiological characteristics of the latex vessels. In the first three years of evaluation, the panel clones IAN 2878, IAN 2903, CNS AM 7905, CNS AM 7905 P1, and PB 28/59 showed the highest dry rubber yield potential, while the clones IAN 6158, IAN 6590, and IAN 6515 should not be recommended for crown budding. Higher potassium and copper foliar content in panel clones were associated to an increase in dry rubber yield. The simultaneous evaluation of anatomical and physiological characteristics of latex is fundamental for the selection of panel clones in the Amazon region. Crown budding is an efficient technology for South American leaf blight management in endemic regions.

Different methods to assess yield temporal stability in rubber

The objective of this work was to assess, during six years, the temporal stability of natural rubber yield of 25 superior Hevea brasiliensis genotypes, using the Wricke, Eberhart & Russell, Lin & Binns, additive main effect and multiplicative interaction (AMMI) analysis, and harmonic mean of the relative performance of the genetic values (HMRPGV) methods. The IAC 40 and IAC 300 genotypes were identified as stable and high yielding by the Eberhart & Russell, Lin & Binns, HMRPGV, and AMMI Biplot methods. The ranking of the other more stable genotypes identified by these analyses was altered. The observed results in the AMMI Biplot agreed with those observed in the Wricke method for identifying stable, but lower yielding genotypes. The simultaneous use of different methods allows a more accurate indication of stable genotypes. Stability analyses based on different principles show agreement in indicating stable genotypes.

A whole body transportable indirect calorimeter for human use in the tropics.

A transportable, whole body indirect calorimeter, designed for use in the tropics, is described. The calorimeter was built to study energy expenditure of people having chronically or acutely low levels of food intake, and it will help to determine energy adaptations made by individuals with restricted food intake. The calorimeter comprises two units: a 27 m3 ventilated chamber connected to an office housing control and monitoring equipment. The system also allows the experimenter to assess the rate of energy expenditure by means of a ventilated hood or a baby respiration chamber. The incoming air flow rate is variable and is typically set at approximately 30 l/min. Carbon dioxide production (VCO2) and oxygen consumption (VO2) are continuously monitored by means of differential gas analysers via a computerized data acquisition unit. Gas production/consumption rates are measured with a delay of 80 s, the complete response to step changes in VCO2 or VO2 consumption being calculated over 15 min using the rate of change terms in the gas exchange equations. The total electrical power required for the whole system is 12 kW. The calorimeter has been functioning for nearly 4 years in a rural village of The Gambia during which ambient temperatures have ranged from 16 to 44 degrees C and dewpoints from -8 to 24 degrees C. The performance and accuracy of the calorimeter were tested using 20 per cent CO2 in N2 infusion and butane burning. Agreement between the theoretical and the measured values was found to be 99 per cent for VO2 and 100 per cent for VCO2 with a precision for both gases of +/- 10 ml/min over a 1-h period.

Prediction of direct and indirect genetic gains and genotypic correlations in rubber tree progenies

The objective of this work was to estimate the genetic parameters, genotypic and phenotypic correlations, and direct and indirect genetic gains among and within rubber tree (Hevea brasiliensis) progenies. The experiment was set up at the Municipality of Jaú, SP, Brazil. A randomized complete block design was used, with 22 treatments (progenies), 6 replicates, and 10 plants per plot at a spacing of 3x3 m. Three‑year‑old progenies were assessed for girth, rubber yield, and bark thickness by direct and indirect gains and genotypic correlations. The number of latex vessel rings showed the best correlations, correlating positively and significantly with girth and bark thickness. Selection gains among progenies were greater than within progeny for all the variables analyzed. Total gains obtained were high, especially for girth increase and rubber yield, which were 93.38 and 105.95%, respectively. Young progeny selection can maximize the expected genetic gains, reducing the rubber tree selection cycle.

Evaluation of Recycled Rubber in Asphalt Concrete, HR-330, Construction Report, 1991

Discarded tires present major disposal and environmental problems. The recycling of those tires in asphalt cement concrete is what this research deals with. The Iowa DOT and the University of Northern Iowa (UNI) are evaluating the use of discarded tires in asphalt rubber cement and rubber chip mixes. The project is located on US 61 between Blue Grass and Muscatine in Muscatine County. It contains four rubberized asphalt sections and control sections. One section consists of reacted rubber asphalt cement used in both the binder and surface courses, and one section, both lanes, contains a rubber chip mix. The reacted rubber asphalt and the rubber chip mixes were laid in July 1991. The project construction went well with a few problems of shoving and cracking of the mat. This report contains information about procedures and tests that were run and those that will be run. It also has a cost comparison since this is a major concern with the use of asphalt rubber. Evaluation of this project will continue for five years. Three more research projects containing rubberized asphalt were constructed in 1991 and another is to be constructed in 1992.

Evaluation of Recycled Rubber in Asphalt Concrete - Black Hawk County, HR-330B, Construction Report, 1992

The disposal of discarded tires has become a major problem. Different methods of recycling have been researched. Currently, Iowa is researching the use of ground recycled crumb rubber from discarded tires in asphalt rubber cement. Six projects have been completed in Iowa using asphalt rubber cement. This project is located on IA 947 (University Avenue) in Cedar Falls/Waterloo. The project contains one section with asphalt rubber cement used in both the binder and surface courses and one section using asphalt rubber cement in the surface course with a conventional binder. There are two control sections where conventional asphalt pavement was placed.

Accelerated digestion for high-throughput proteomics analysis of whole bacterial proteomes.

In bottom-up proteomics, rapid and efficient protein digestion is crucial for data reliability. However, sample preparation remains one of the rate-limiting steps in proteomics workflows. In this study, we compared the conventional trypsin digestion procedure with two accelerated digestion protocols based on shorter reaction times and microwave-assisted digestion for the preparation of membrane-enriched protein fractions of the human pathogenic bacterium Staphylococcus aureus. Produced peptides were analyzed by Shotgun IPG-IEF, a methodology relying on separation of peptides by IPG-IEF before the conventional LC-MS/MS steps of shotgun proteomics. Data obtained on two LC-MS/MS platforms showed that accelerated digestion protocols, especially the one relying on microwave irradiation, enhanced the cleavage specificity of trypsin and thus improved the digestion efficiency especially for hydrophobic and membrane proteins. The combination of high-throughput proteomics with accelerated and efficient sample preparation should enhance the practicability of proteomics by reducing the time from sample collection to obtaining the results.