The Effect of Cadmium on GFR Is Clarified by Normalization of Excretion Rates to Creatinine Clearance

Erroneous conclusions may result from normalization of urine cadmium and N-acetyl-β-D-glucosaminidase concentrations ([Cd]_u and [NAG]_u) to the urine creatinine concentration ([cr]_u). In theory, the sources of these errors are nullified by normalization of excretion rates (E_Cd and E_NAG) to creatinine clearance (C_cr). We hypothesized that this alternate approach would clarify the contribution of Cd-induced tubular injury to nephron loss. We studied 931 Thai subjects with a wide range of environmental Cd exposure. For x = Cd or NAG, E_x/E_cr and E_x/C_cr were calculated as [x]_u/[cr]_u and [x]_u[cr]_p/[cr]_u, respectively. Glomerular filtration rate (GFR) was estimated according to the Chronic Kidney Disease (CKD) Epidemiology Collaboration (eGFR), and CKD was defined as eGFR < 60 mL/min/1.73m². In multivariable logistic regression analyses, prevalence odds ratios (PORs) for CKD were higher for log(E_Cd/C_cr) and log(E_NAG/C_cr) than for log(E_Cd/E_cr) and log(E_NAG/E_cr). Doubling of E_Cd/C_cr and E_NAG/C_cr increased POR by 132% and 168%; doubling of E_Cd/E_cr and E_NAG/E_cr increased POR by 64% and 54%. As log(E_Cd/C_cr) rose, associations of eGFR with log(E_Cd/C_cr) and log(E_NAG/C_cr) became stronger, while associations of eGFR with log(E_Cd/E_cr) and log(E_NAG/E_cr) became insignificant. In univariate regressions of eGFR on each of these logarithmic variables, R² was consistently higher with normalization to C_cr. Our tabular and graphic analyses uniformly indicate that normalization to C_cr clarified relationships of E_Cd and E_NAG to eGFR.     

Different design scenarios related to an open loop groundwater heat pump in a large building: Impact on subsurface and primary energy consumption

A multidisciplinary methodology is proposed for analyzing opportunities to use existing boreholes and an open-loop groundwater heat pump to provide summer cooling needs for large university buildings in Turin (NW Italy). The approach starts from a model of the buildings to determine the time profile of the cooling load. This curve is then coupled with a model of the off-design behaviour of the heat pump, which allows calculation of its energy performance (coefficient of performance, electricity consumption, etc.) as well as profiles of water discharge to the aquifer in terms of mass flow rate and temperature.Covering the peak energy needs of the buildings requires a variable amount of groundwater during the day. This could be provided varying the withdrawals from the aquifer but, as possible alternatives, two storage system solutions are examined: (1) chilled water storage and (2) groundwater storage. Simulations show that in both cases the use of storage systems produces environmental advantages, as the extent of the thermal plume reduces significantly. Moreover, chilled water storage presents a benefit in terms of reduced total primary energy consumption. The additional costs incurred by storage systems could necessitate public funding as well as system optimization.     

The pedunculopontine tegmental nucleus and responding for sucrose reward.

Pedunculopontine tegmental nucleus (PPTg) lesions in rodents lead to increased sucrose consumption, but the psychological deficit behind this remains uncertain. To understand better the relationship between consumption of, and motivation for, sucrose, the authors trained rats to traverse a runway for 20% or 4% sucrose solution; after 7 days, concentrations were reversed. Control rats consumed more 20% than 4% sucrose solution and promptly altered run times in response to concentration change. PPTg-lesioned rats consumed normal quantities of 4% but more 20% sucrose solution than controls and took longer to alter their runway time following the concentration change. These data suggest that lesions of the PPTg do not alter motivation per se and might be better understood as inducing a response selection deficit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Controlling baseline trend in single-case research.

School psychologists commonly conduct interventions for individual students and evaluate their success through single-case research designs, most of which include a baseline observation period. However, concluding intervention effectiveness from a single-case design is problematic when pronounced baseline trend is evident. With positive baseline trend, interpretation of the measured mean difference between phases is ambiguous, and an invalid interpretation is probable. Although an adequate method for controlling baseline trend exists, it is rarely applied in published studies. This article seeks wider application of baseline trend control by describing a modified technique that blends more easily with visual analysis. A second goal of this article is to encourage better informed use of baseline trend control, by empirically demonstrating its need in published studies, and its impact on R2 effect sizes and on autocorrelation. Finally, baseline trend control is combined with elimination of autocorrelation, for results that can withstand the scrutiny of the broader research community. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus and response contingencies in the misbehavior of rats.

Misbehavior by rats was produced in Exps I (16 Wistar female albino rats) and II (15 Sprague-Dawley female albino rats) by pairing a ball bearing with food or by requiring contact with the ball bearing for food (Exps IV, 6 Ss, and V, 11 Ss). Misbehavior occurred before and after eating the food pellet. The frequency, complexity, and duration of prepellet misbehavior was increased by delay of food until after the ball bearing exited (or was programmed to exit) and by requiring contact with the bearing to obtain food. Alternative goal-directed behaviors occurred in Pavlovian contingencies in which food was delivered before the bearing was programmed to exit. Postpellet misbehavior tended to occur when food was delivered before the bearing was programmed to exit and before S released the bearing. Omission of food delivery on contact reduced the duration, complexity, and frequency of misbehavior, although experienced Ss continued to contact (Exp III, 15 Ss). Misbehavior was affected by both stimulus- and response-reward contingencies but showed characteristic organization and topography under both types of contingency. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fatty acid composition of maturingVernonia anthelmintica (L.) Willd. seeds. dihydroxyoleic acid—A possible precursor of epoxyoleic acid

Quantitative measurements of epoxyoleic acid and co-occurring fatty acids in maturingVernonia anthelmintica (L.) Willd. seeds were made to elucidate partially the mode of epoxyoleic biosynthesis. Free (+)threo-12,13-dihydroxy-cis-9-octadecenoic acid was the major component at an intermediate maturation stage, and is believed to be dehydrated to free epoxyoleic acid before incorporation into glycerides. Presented before the Division of Biological Chemistry, Am. Chem. Soc. meeting in St. Louis, Mo., 1961. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Effect of visual experience on the habituation of orienting behavior.

Three experiments studied the orienting behavior (OB) at 30, 60, 90, or 120 days old of male Long-Evans rats, of whom 88 were light-reared (LR) and 84 dark-reared (DR). OB was assessed by examining S's ability to interrupt ongoing licking and perform appropriate head and postural adjustments when presented with apparently moving or stationary light displays or tones. When the lights were first presented to the LR and DR Ss, their OB did not differ at any of the ages. However, age and visual experience did influence habituation and recovery of orienting with changes in the light display. The older DR Ss habituated with fewer repeated presentations of the light displays than the LR Ss and did not recover orienting as effectively to all the subsequent changes of the light displays. The younger LR and DR Ss did not differ reliably. Results are discussed with regard to the nature of the habituation process for rodents and the relation between visual experience and habituation of attentional responses. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Search for new industrial oils. IV

Summary Chemical screening of seed oils continues to reveal nature's diversity. This work provides leads to numerous species which warrant further research to investigate their oil and meal in greater detail, to appraise their crop potential, and to assess their practical value for providing new oilseeds. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U. S. Department of Agriculture. Agricultural Research Service, U. S. Department of Agriculture.     

PAR2-Induced Tissue Factor Synthesis by Primary Cultures of Human Kidney Tubular Epithelial Cells Is Modified by Glucose Availability

Coagulopathies common to patients with diabetes and chronic kidney disease (CKD) are not fully understood. Fibrin deposits in the kidney suggest the local presence of clotting factors including tissue factor (TF). In this study, we investigated the effect of glucose availability on the synthesis of TF by cultured human kidney tubular epithelial cells (HTECs) in response to activation of protease-activated receptor 2 (PAR2). PAR2 activation by peptide 2f-LIGRLO-NH₂ (2F, 2 µM) enhanced the synthesis and secretion of active TF (~45 kDa) which was blocked by a PAR2 antagonist (I-191). Treatment with 2F also significantly increased the consumption of glucose from the cell medium and lactate secretion. Culturing HTECs in 25 mM glucose enhanced TF synthesis and secretion over 5 mM glucose, while addition of 5 mM 2-deoxyglucose (2DOG) significantly decreased TF synthesis and reduced its molecular weight (~40 kDa). Blocking glycosylation with tunicamycin also reduced 2F-induced TF synthesis while reducing its molecular weight (~36 kDa). In conclusion, PAR2-induced TF synthesis in HTECs is enhanced by culture in high concentrations of glucose and suppressed by inhibiting either PAR2 activation (I-191), glycolysis (2DOG) or glycosylation (tunicamycin). These results may help explain how elevated concentrations of glucose promote clotting abnormities in diabetic kidney disease. The application of PAR2 antagonists to treat CKD should be investigated further.