Metabolic function glucose abnormalities

Measurements of regional cerebral blood flow by PET and of cerebral perfusion by SPECT often detect functional abnormalities before CT or MRI identifies morphological abnormalities 945 The PET method is a valuable tool for the estimation of regional glucose and oxygen metabolic rates and cerebral blood flow 946 PET and SPECT combined with principles of receptor binding permit imaging of receptors in the intact brain 946... 

A relatively new technique that uses radioactivity to study body processes and diagnose malfunctions is commonly called positron emission tomography (PET). In this technique radionuclides that decay by positron emission are incorporated into compounds. For example, brain function can be studied by incorporating 1gC into glucose, which is the main source of energy for the brain. By studying how this labeled glucose is metabolized in the brain, doctors can discover abnormalities caused by diseases such as cancer, Parkinson s disease, and epilepsy. 

The function of clinical chemistry in toxicology (as well as in human and veterinary medicine) is to provide, via laboratory analysis, evaluations of the qualitative and quantitative characteristics of specific endogenous chemical components present in samples of blood, urine, feces, spinal fluid, and tissues. The purpose is to help identify abnormal or pathological changes in organ system functions. The most common specimens used in clinical chemistry are blood and urine, and many different tests exist to test for almost any type of chemical component in blood or urine for example, blood glucose, electrolytes, enzymes, hormones, lipids (fats), other metabolic substances, and proteins. The tests used were all initially applied to human clinical medicine, and may not possess the same utility when performed as part of nonclinical toxicity studies in a wide variety of other species. 

Disturbances in lipid metabolism also may occur, resulting in transitory increase of blood values for cholesterol and triglycerides. Liver function and serum lipids should initially be monitored, typically at baseline and at weeks 4 and 8. Serious adverse effects of isotretinoin therapy include increased creatine phosphokinase and blood glucose, as well as photosensitivity, pseudotumor cerebri, excess granulation tissue, hepatomegaly with abnormal liver function tests, bone abnormalities, arthralgias, muscle stiffness, and headaches. ... 

Toxicity and interactions Neurotoxic effects are common and include peripheral neuritis, restlessness, muscle twitching, and insomnia. These effects can be alleviated (without blocking the antibacterial effect) by administration of pyridoxine. INH is hepatotoxic and may cause abnormal liver function tests, jaundice, and hepatitis. Fortunately, hepatotoxicity is rare in children. INH may inhibit the hepatic metabolism of dmgs, eg, phenytoin. Hemolysis has occurred in patients with glucose-6-phosphate dehydrogenase deficiency. A lupuslike syndrome has been reported. 

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