Disposal Activity Research Articles

Effect of 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside infusion on in vivo glucose and lipid metabolism in lean and obese Zucker rats.

Activation of AMP-activated protein kinase (AMPK) with 5-aminoimidazole-4-carboxamide-1-beta-D-ribofurano-side (AICAR) increases glucose transport in skeletal muscle via an insulin-independent pathway. To examine the effects of AMPK activation on skeletal muscle glucose transport activity and whole-body carbohydrate and lipid metabolism in an insulin-resistant rat model, awake obese Zuckerfa/fa rats (n = 26) and their lean (n = 23) littermates were infused for 90 min with AICAR, insulin, or saline. The insulin infusion rate (4 mU.kg(-1).min(-1)) was selected to match the glucose requirements during AICAR (bolus, 100 mg/kg; constant, 10 mg.kg(-1).min(-1)) isoglycemic clamps in the lean rats. The effects of these identical AICAR and insulin infusion rates were then examined in the obese Zucker rats. AICAR infusion increased muscle AMPK activity more than fivefold (P < 0.01 vs. control and insulin) in both lean and obese rats. Plasma triglycerides, fatty acid concentrations, and glycerol turnover, as assessed by [2-13C]glycerol, were all decreased in both lean and obese rats infused with AICAR (P < 0.05 vs. basal), whereas insulin had no effect on these parameters in the obese rats. Endogenous glucose production rates, measured by [U-13C]glucose, were suppressed by >50% during AICAR and insulin infusions in both lean and obese rats (P < 0.05 vs. basal). In lean rats, rates of whole-body glucose disposal increased by more than two-fold (P < 0.05 vs. basal) during both AICAR and insulin infusion; [3H]2-deoxy-D-glucose transport activity increased to a similar extent, by >2.2-fold (both P < 0.05 vs. control), in both soleus and red gastrocnemius muscles of lean rats infused with either AICAR or insulin. In the obese Zucker rats, neither AICAR nor insulin stimulated whole-body glucose disposal or soleus muscle glucose transport activity. However, AICAR increased glucose transport activity by approximately 2.4-fold (P < 0.05 vs. control) in the red gastrocnemius from obese rats, whereas insulin had no effect. In summary, acute infusion of AICAR in an insulin-resistant rat model activates skeletal muscle AMPK and increases glucose transport activity in red gastrocnemius muscle while suppressing endogenous glucose production and lipolysis. Because type 2 diabetes is characterized by diminished rates of insulin-stimulated glucose uptake as well as increased basal rates of endogenous glucose production and lipolysis, these results suggest that AICAR-related compounds may represent a new class of antidiabetic agents.

Impact of implementation of an embryo storage fee on embryo disposal activity

Objective: To examine the impact of implementation of a new fee for continued storage of cryopreserved embryos on the rate of requests for disposal of embryos. Design: Retrospective cohort study. Setting: A university-based assisted reproduction program. Patient(s): All patients with cryopreserved embryos. Intervention(s): Implementation of a semiannual embryo storage fee of $100 to cover administrative and laboratory costs. Main Outcome Measure(s): The number of embryo disposal requests before and after implementation of the embryo storage fee was compared in relation to the activity of the cryopreserved embryo program as measured by number of frozen embryo transfers. Result(s): Annual requests for embryo disposal from 1992 through 1997 ranged from zero to three, which represented 0–5% of the annual frozen embryo program activity. In contrast, a significantly higher number of disposal requests (10, representing 18% of program activity) were received in 1998. Conclusion(s): Fees for storage of cryopreserved embryos seem to influence patients’ decisions about disposal of cryopreserved embryos.

Evaluation of disposal limits for shallow land burial facilities: Application to the back end of nuclear fuel cycle

The limits on disposal rates and activity concentrations in radioactive wastes have been computed using different release scenarios for about 26 radionuclides commonly encountered in a shallow land burial facility originating from the back end of nuclear fuel cycle. These limits are then segregated for major specific radionuclides/groups of radionuclides on the basis of a critical scenario/critical pathway concept indicating signatory radionuclides for monitoring purposes. Disposal rates and activity concentrations of short lived ß, γ radionuclides and 137Cs are limited by the external exposure route to occupational workers. The well-water-drinking pathway limits the disposal rates and activity concentrations of 3H and long lived ß, γ radionuclides having low K d owing to their rapid migrational characteristics. The dwelling-inhalation pathway restricts activity concentration limits of α bearing wastes.

Feeding Habits of Winter Flounder (Pleuronectes americanus) in a Habitat Exposed to Anthropogenic Distribution

The feeding habits of the winter flounder (Pleuronectes americanus) were examined in a habitat subjected to chronic anthropogenic disturbance by organic and inorganic nutrient disposal and shipping activity. The macrobenthic community was numerically dominated by the types of polychaetes and amphipods found in a disturbed community. Little variability was found in the diets of 151 winter flounder (100–300 mm total length) in 4 size-classes. Combining all size-classes, winter flounder were found to feed on 18 different genera of macrobenthos. Amphipods and polychaetes dominated the diet. These groups provided from 12–25% of the diet by weight, 16–48% by number, and had index of relative importance values between 552 and 2 510. Major prey items were the amphipod, Ampelisca abdita and the polychaete, Streblospio benedicti. These diets were compared to those winter flounder captured in habitats where benthic assemblages were not exposed to human perturbation. Regardless of habitat, winter flounder fed on primarily the most abundant and active benthic species. This study supports the contention that winter flounder are in general, opportunistic feeders and usually feed on the most abundant and available prey source.

Testing the waters: An analytical framework for testing the political feasibility of scenario-based proposals for disposing of CO2 in the oceans

Industrial nations need an array of arrangements to meet obligations for the Rio Treaty CO 2 emissions standards for the year 2000. Ocean storage of power plant CO 2 emissions is one option. Two strategies seem feasible: 1) Transfer CO 2 directly from the power plant by pipeline to the appropriate ocean depth and release it through diffusers; 2) transport contained CO 2 to an offshore site and diffuse it by pipe to appropriate depths. However, jurisdictional location of the disposal site, the environmental consequences of the diffused CO 2 on water quality and living resources, and public understanding and acceptance will ultimately influence decisions. Legality will be tested by The London Dumping Convention, The Law of the Sea Convention, the RIO Treaty and Agenda 21. Public acceptance will depend on public trust. This paper presents a decision framework based on the two ocean disposal scenarios above. It allows scientists and policy-makers to examine these strategies using legal and socio-political baseline parameters. Both disposal strategies, if determined feasible, would have added costs necessary to assure the public of the integrity of the disposal activity. This decision framework helps policy makers formulate questions, determine trade-offs, and ultimately decide the practicality of the CO 2 Ocean Disposal strategy.

Operator liability for directors and officers under CERCLA

CERCLA Section 107(a) imposes liability on “operators”; of facilities where there has been a release or threatened release of hazardous substances. However, CERCLA contains no clear definition of “operator.”; Therefore, it has been left to the courts to interpret the term. Courts dealing with issues of corporate director and officer liability under CERCLA Section 107(a) have differed in their approach to such liability. Some have determined that CERCLA does not change the traditional rule of corporate liability, holding that directors or officers are liable only if they were directly involved in the disposal activity leading to the release or threatened release. Others have found liability where directors or officers exercised control over the facility where the release or threatened release occurred, even if they had no involvement in or awareness of the actual disposal activities. A third group has found liability where officers or directors had the capacity to control disposal activities, even if that ...

Glycogen synthase activity in two rat models of hypertension

Several studies on both humans and animal models have reported a pathogenetic relationship among hyperinsulinism, insulin resistance, and hypertension. We have previously evaluated whole body glucose disposal and insulin sensitivity in different models of hypertensive rats, showing an increase rather than an impairment of glucose metabolism, which in turn was due to an improved ability of insulin to channel the absorbed glucose towards the nonoxidative disposal. Aiming to confirm our previous findings we performed the direct assay of skeletal muscle glycogen synthase on tissue samples from the previous clamp studies, as a rate limiting step enzyme of glycogen synthesis, under conditions of physiologic hyperinsulinemia and euglycemia. Glycogen synthase was assayed on samples from rectus muscle tissues of spontaneously hypertensive rats and high sodium, one kidney, one figure-8 hypertensive rats. Compared to controls, our data show an increased activity of glycogen synthase in the hypertensive animals, which is consistent with the increased glycogen synthesis previously reported. In conclusion, under our experimental conditions, hypertension and chronic hyperadrenergism are associated with an increased ability of insulin to stimulate glucose uptake and disposal. These latter effects are mainly due to an increase in nonoxidative disposal and glycogen synthase activity.

Abdominal obesity is associated with insulin resistance and reduced glycogen synthase activity in skeletal muscle

Insulin resistance is commonly associated with obesity. The present study was performed to investigate the relative importance of total fat mass versus localization of adipose tissue in insulin-stimulated glucose disposal (R d) and skeletal muscle glycogen synthase (GS) activity in obese individuals. Twenty obese women with an average body mass index (BMI) of 37.8 ± 1.3 kg/m 2 and a waist to hip ratio (WHR) ranging from 0.78 to 1.02 were examined during basal conditions and following hyperinsulinemia (hyperinsulinemic euglycemic clamp). To accurately determine body composition, the following three methods were used: anthropometric measurements, dual-energy x-ray absorptiometry scanning (DEXA-scan), and bioelectric impedance measurements. In addition, indirect calorimetry and muscle biopsy were performed. Insulin-stimulated glucose R d was negatively correlated with WHR ( R = −.52, P < .025) whereas there were no correlations with BMI or percent fat ( R = .16, NS and R = .16, NS, respectively). Furthermore, a negative correlation between WHR and insulin stimulation of GS activity in skeletal muscle was found ( R = −.62, P < .005). In contrast, BMI and percent fat were not correlated with the insulin effect on GS activity in skeletal muscle ( R = .34, NS and R = −.35, NS, respectively). The concentration of nonesterified fatty acids (NEFA) during hyperinsulineamia was strongly correlated with WHR and abdominal localization of adipose tissue (determined by DEXA-scan; R = .60, P < .005 and R = .60, P < .007, respectively). Moreover, lipid oxidation during hyperinsulinemia was positively correlated with WHR ( R = .58, P < .007), whereas there was no correlation with BMI or percent fat ( R = .31, NS and R = .29, NS, respectively). Finally, NEFA concentrations during hyperinsulinemia were negatively correlated with insulin-stimulated glucose R d ( R = .73, P < .0009). We conclude that in a group of massively obese women localization of adipose tissue in the abdominal region (assessed by various techniques) was accompanied by impaired insulin-stimulated glucose R d, decreased capacity of insulin to stimulate GS activity in skeletal muscle, and higher circulating NEFA concentrations during the hyperinsulinemic period. In contrast, no correlations between BMI, percent fat, or other measurements of total amount of adipose tissue and these variables were found. Finally, the sophisticated measurements (DEXA-scan and bioelectric measurements) were not superior to BMI and WHR in predicting insulin resistance in this group of obese women.

Gliclazide and insulin action in human muscle

Sulfonylureas are widely used drugs in the treatment of NIDDM when diet treatment is unsuccessful. In addition to their pancreatic effects sulfonylureas have been reported to have insulin-like and insulin-potentiating actions in vitro with respect both to glucose transport and glycogen synthase activation in isolated adipocytes and hepatocytes from rats. Glycogen synthesis in muscle accounts for the major part of non-oxidative glucose metabolism during insulin stimulation. Treatment with gliclazide of patients with NIDDM has been shown to be associated with a potentiation of both insulin-mediated glucose disposal and insulin-stimulated glycogen synthase activity in skeletal muscle. Muscle insulin receptor binding or insulin receptor kinase activity was shown not to be affected by gliclazide treatment. Whether the improved insulin sensitivity and improved insulin action on skeletal muscle glycogen synthase during gliclazide treatment is due to a direct or an indirect action of the drug is discussed.

Changes in Muscle Glucose Metabolism in Type 1 Diabetes

Patients with type 1 diabetes are characterized by an average 40% reduction in the insulin sensitivity. In newly diagnosed patients, insulin resistance is due to insulin deficiency and its metabolic consequences. After the beginning of insulin therapy, insulin sensitivity transiently improves, but deteriorates again after 6-9 months of insulin therapy. Insulin resistance is mainly due to a reduction in glucose uptake by muscle tissue. There are similar relative reductions in both oxidative and nonoxidative glucose disposal. When glucose disposal is determined under similar plasma glucose and insulin concentrations, glucose oxidation, the activity of pyruvate dehydrogenase and glycogen synthase are all reduced. If glucose disposal rate in diabetic patients is normalized by glucose mass action, both oxidative and nonoxidative glucose disposal and glycogen synthase activity become normal. As the normalization of glucose disposal occurs in the face of unchanged muscle glucose-6-phosphate concentrations, this suggest that reduced glucose disposal is secondary to reduced glucose transport in type 1 diabetes.

Insulin response of components of whole-body and muscle carbohydrate metabolism in humans.

We measured total body insulin-mediated glucose uptake, carbohydrate oxidation, storage (nonoxidative disposal), muscle glycogen synthase activity, and muscle glucose 6-phosphate (G-6-P) content in response to five levels of insulinemia (means 16, 52, 152, 573, and 5,550 microU/ml) in 16 male glucose-tolerant volunteers. Insulin dissociation constants (KDs) for disposal, storage, and synthase activity (but not for oxidation) are coincident, suggesting that storage via glycogen synthesis could be a major determinant of glucose disposal. Increases in glucose disposal were associated with decreases in muscle G-6-P concentration. These data suggest that the principal control over carbohydrate disposal is exerted after G-6-P. The coincidence of insulin sensitivities for disposal, storage, and synthase activity suggest that storage via glycogen synthesis could be a major determinant of glucose disposal.

Hazardous waste remedial action — Picillo Farm, Coventry, Rhode Island; an overview

Following the discovery of buried chemical wastes which caused a fire and explosion at the Picillo Farm in Coventry, Rhode Island, the State of Rhode I A hydrogeological site investigation was conducted which included ground and surface water monitoring, seismic studies and ground penetrating radar. Fo Cleanup of the first trench began in summer 1980 and concluded that fall, with 2300 barrels being removed. Planning for the second trench excavation an In November 1980, invitation to bid on the excavation and disposal of barrels from the so called northwest trench was requested. When the U.S. EPA offe Subsequently, Rhode Island decided to assume the excavation portion of the project and dispose of the wastes as far as funding would allow. Mobilizatio In the excavation phase of the work effort, a total of 4400 barrels of hazardous wastes were removed: 40% contained liquid hazardous waste, 40% solid h Site preparation, placement of work areas, excavation and waste transfer techniques, air quality monitoring and operational problem areas are among top This paper addresses the chronology of events which took place during the 1981 cleanup efforts, comments upon the variety of problems encountered and d The cleanup of unauthorized hazardous waste sites presents varied operational and environmental problems. This paper attempts to provide insight into t Field and off-site disposal analyses proved to be a problem in terms of turnaround time and procedural techniques. Particular attention must be paid to One of the primary operational constraints involves reducing the risk of injury and adverse health effects to personnel working on site and the surroun Funding of a project of this scope must account for the significant unknown factors associated with hazardous wast cleanup, i.e., What is the amount an Every attempt must be made closely monitor contractual obligations. Thorough negotiations and understanding prior to commencement of a project will red No hazardous waste disposal activity can be risk free. Therefore, safety precautions are paramount. Yet budget limitations are real and require conside The generation of contaminated soil poses a significant disposal problem. Successful efforts were made to limit this problem in Phase II in terms of th Finally, and most importantly, all activities should be closely coordinated with any citizens organization or affected group that deals with the issues

Empirical Study of the Households's Production of Refuse Within the Framework of a New Consumer Theory

The paper focuses on linking refuse (combustible solid waste) from household consumption activities to consumer behaviour and to the municipal delivery of refuse collection services. The theoretical framework used in conceptualizing the refuse disposal process and its relationship to household consumption behaviour is based on Lancaster-Muth-Becker's new approach to consumer theory. Within the framework, a household behaviour with respect to consumption activities and associated refuse is described as a utility maximization problem. The objective is a utility function over the characteristic space, where the major characteristic yielded by household's refuse disposal activity is assumed to be the cleanliness of private space. Constraints include: three sets of technological relations linking goods purchased, refuse disposed, and the characteristics produced through a collection of consumption activities, residential environment of household, and the type of municipal collection services; a budget constraint which incorporates the alternative municipal financing of service, general revenue financing and pricing of refuse; and the public production of collection service which is a function of the total amount of refuse and of tax to be collected.Data required for the estimation of technological relations were secured through survey questionaires with the random sample of 1000 households, conducted in the eight municipalities of the Tokyo Metropolitan Region during Nov. 25-Dec. 1 of 1979. These eight municipalities employ different collection services in terms of frequency of service (twice a week and thrice a week) and of site of collection (backyard and curbside). Data on residential environments of surveyee were obtained through observations of sites, pictures, and maps.Due to the difficulty of integrating the residential environmental quality into a few indices, we categorized via the use of “Hayashi's Quantification Theory” the residential environments of surveyee into five homogeneous environments. In each categorized environment, linear stochastic forms of technological relations were estimated using ordinary least squares procedures. The empirical results were utilized to evaluate the alternative municipal policies concerning the financing of collection service. The results show that the pricing scheme is preferred to customary method of general revenue financing. For the former exerts not only an income effect but also a substitution effect upon households' refuse production, while the latter exerts only an income effect.