Glucose, blood

The various topics in this chapter are listed by clinical application blood chemistry, tissues, cancer, and so forth. Certain topics may be difficult to assign to a particular clinical application. In such cases, the authors decision was to place the referenced paper in the most general application available. References to blood glucose, for instance, might appear in the sections headed Blood Glucose (7.1), Review articles (7.9), and Blood Chemistry (7.5). With hundreds of papers on each subject, we have chosen a cross section of the topics. This chapter is not intended to represent every paper published on the subject. 

Nevertheless, many authors have published on methods to predict blood glucose. In 1993 [9], Arnold and Marquardt published a paper modeling the NIR measurement of glucose in a protein-containing matrix. 

David Haaland et al. added to the modeling literature with a 1992 paper [15]. This work used whole blood for the model. Scanning from 1500 to 2400 nm, a PLS equation was developed on glucose-spiked whole blood. The range between 0.17 and 41.3 mM yielded an equation with a standard error of 1.8 mM. Four patients were used as models for this project. Cross-validated PLS standard errors for glucose concentration based on data obtained from all four subjects were 2.2 mM. When PLS models were developed on three patients blood samples and tested on the fourth, the glucose predictions were poor. The conclusion was that models must be developed for individual patients due to intersubject variability of blood chemistry. 

However, contradicting this work was a paper by Sternberg et al. [19]. This group claimed that tissue contained only 75% of the glucose level found in blood. Fortunately, NIR measurements are inclusive of blood and tissue. The calibration was based on a point of contact for each individual patient thus, the ratio of tissue to venous/arterial blood will be a constant. Correlation of the spectra to blood glucose readings is then acceptable. 

In order to model more correctly the in vivo realities of human body chemistry, phantoms (simulated biological conditions, containing fat, blood, skin, etc.) were built for simulated in vivo testing. Arnold et al. built phantoms of water, fat, and muscle tissue to mimic the skin of a patient [20]. They found that in vivo overtone spectra collected across human webbing tissue with a thickness of 6.7 mm could be simulated with a water layer thickness from 5.0 to 6.4 mm combined with a fat layer thickness from 1.4 to 4.2 mm. For the purposes of this study, animal tissue and fat were used there is little difference in composition between human and animal materials. They concluded that these phantom studies would help researchers develop patient-applicable methods. 

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Let s consider the following problem. Two sets of blood samples have been collected from a patient receiving medication to lower her concentration of blood glucose. One set of samples was drawn immediately before the medication was administered the second set was taken several hours later. The samples are analyzed and their respective means and variances reported. ITow do we decide if the medication was successful in lowering the patient s concentration of blood glucose ... 

Wang, J. Macca, C. Use of Blood-Glucose Test Strips for Introducing Enzyme Electrodes and Modern Biosensors, ... 

Commercially available kits for monitoring blood-glucose use an amperometric biosensor incorporating the enzyme glucose oxidase. This experiment describes how such monitors can be adapted to the quantitative analysis of glucose in beverages. 

Blood factors Blood flukes Blood glucose... 

Biosynthetic Human Insulin from E. coli. Insulin [9004-10-8] a polypeptide hormone, stimulates anaboHc reactions for carbohydrates, proteins, and fats thereby producing a lowered blood glucose level. Porcine insulin [12584-58-6] and bovine insulin [11070-73-8] were used to treat diabetes prior to the availabiHty of human insulin [11061 -68-0]. AH three insulins are similar in amino acid sequence. EH LiHy s human insulin was approved for testing in humans in 1980 by the U.S. EDA and was placed on the market by 1982 (11,12). 

Control of secretion of anterior pituitary hormones also includes inhibition by hormones produced by target organs. For example, CRH stimulates the anterior pituitary to secrete ACTH, which in turn stimulates the adrenal cortex to secrete corticosteroids. Corticosteroids then feed back to inhibit the secretion of ACTH. Feedback mechanisms are important for the control of most hormones. For example, insulin (qv) secretion from the pancreas increases in response to increased blood glucose resulting from ingestion of a meal. Insulin increases tissue uptake and metaboHsm of glucose, which lowers blood glucose and in turn reduces insulin secretion. 

The classic experiments of Von Meting and Minkowski in 1889 first impHcated the pancreas in regulating blood glucose levels removal of a dog s pancreas led directly to the development of hyperglycemia. Then in the early 1920s it was shown that an internal secretion of the pancreas could be isolated... 

Relative potency alone does not determine dmg selection because maximal effectiveness is similar for all agents. A single daily dose of any sulfonylurea, except tolbutamide, is sometimes adequate to control blood glucose in NIDDM patients. 

Metformin. Metformin [657-24-9] (1,1-dimethylbiguanide), mol wt 129.17, forms crystals from propanol, mp 218—220°C, and is soluble in water and 95% ethanol, but practically insoluble in ether and chloroform. Metformin, an investigational dmg in the United States, does not increase basal or meal-stimulated insulin secretion. It lowers blood glucose levels in hyperglycemic patients with Type II diabetes but has no effect on blood glucose levels in normal subjects. It does not cause hypoglycemia. Successful metformin therapy usually is associated with no or some weight loss. 

Fig. 4. Dose response for blood glucose measurement using a dry chemistry system having a water-borne, tough coating film. The numbers represent...

The U.S. market for dmgs to control blood glucose totals about 1 x 10 , equally divided between insulin and all other antidiabetic dmgs (33). Insulin sales ate expected to grow by about 10% annually, whereas the antidiabetic dmg market as a whole is expected to shrink by about 3%. The blood glucose monitoring market totals about 7.5 x 10 in the United States and is expected to grow at a rate of 10% annually. 

The notion that complex carbohydrates eHcit a gradual, steady secretion of insulin while sugars cause a sudden release of this hormone accompanied by a rapid drop in blood glucose has fostered the behef that hypoglycemia is affected by sucrose ingestion. However, research does not support this conclusion (63). 

Blood Glucose and Insulin Response. In humans, ingestion of sugar alcohols has shown a significantly reduced rise in blood glucose and insulin response, owing to slow absorption by the body. As a result, many foods based on sugar alcohols have been used safely in the diets of diabetics (208). 

In man, the metabolic pathways of mepirizole were distinct from those in experimental animals, since hydroxylation on each of the aromatic rings did not occur in man. Compound (752) was obtained by oxidation of the 3-methyl group to the carboxylic acid (a similar process occurs with 5-methylpyrazole-3-carboxylic acid, an active metabolite of 3,5-dimethylpyrazole). However, the carboxylic acid metabolite of mepirizole had no analgesic activity and did not decrease blood glucose. 

Antimony 0.006 0.006 Increase in blood cholesterol decrease in blood glucose Discharge from petroleum refineries fire retardants ... 

Insulin is a peptide hormone, secreted by the pancreas, that regulates glucose metabolism in the body. Insufficient production of insulin or failure of insulin to stimulate target sites in liver, muscle, and adipose tissue leads to the serious metabolic disorder known as diabetes mellitus. Diabetes afflicts millions of people worldwide. Diabetic individuals typically exhibit high levels of glucose in the blood, but insulin injection therapy allows diabetic individuals to maintain normal levels of blood glucose. 

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