Medically important ketones

Some biologically and medically important ketones are shown in Figure 11.38. 

Physical therapists and occupational therapists may help reinforce the importance of patient compliance during pharmacologic management of diabetes mellitus. Therapists can question whether patients have been taking their medications on a routine basis. Regular administration of insulin is essential in preventing a metabolic shift toward ketone body production and subsequent ketoacidosis, especially in patients with type 1 diabetes. In addition, therapists can help explain that adequate control of blood glucose not only prevents acute metabolic problems but also seems to decrease the incidence of the neurovascular complications. 

DKA is the most important and demanding medical emergency within the fields of diabetology and endocrinology. There is no generally accepted definition of DKA and in particular very mild cases may be problematic. As a minimum it seems reasonable to require that pH is below normal range and that levels of ketoacids (ketone bodies) in blood or urine are markedly elevated. As outlined in Table 1 there is a continuous deterioration from clinically insignificant stress ketosis to full blown severe ketoacidosis. In the US population it has been estimated that between 2% and 8% of hospital admissions in children with diabetes are due to DKA [7] and that the annual incidence rate of DKA in children is around 5 per... 

Dimethylacetamine, tetrahydrofuran, dichloromethane, methyl ethyl ketone, N,N-dimethylformamide, N-methylpyrrolidone, cyclopentanone, cyclohexanone, dioxane, and chloroform are the most commonly used solvents. Most of these are hazardous but used because they contribute to highly transparent product which is very desirable in medical devices. Transparent materials can only be made from transparent solutions. These solvents can dissolve polymers well and form clear solutions. Ease of solvent removal from the material is very important in formulation design. Obviously, no traces of solvents should remain in the medical devices since even trace amoimts may interfere with the treatment and the patient s health. An inappropriate solvent selection may cause the formation of crust as the solvent escapes. This leads to material discontinuity (e.g., pinholes) which renders the product inferior. This brings a discussion of solvent evaporation, the rheological properties of formulation, and formation of multilayer materials. 

Chemical compatibility/resistance is of particular importance to medical applications. Disinfectants represent one class of chemicals that includes Betadine , glutaraldehyde-based disinfectants, sodium hypochlorite solution (5 %), ethyl alcohol, isopropyl alcohol, hydrogen peroxide (3 %), and ammonium chloride-based disinfectant. Additionally, resistance to methyl ethyl ketone, saline solution, lipid-based compounds, and fatty acids is important. 

Securinine (1), the parent alkaloid of this astonishing family, was isolated by Murav eva and Ban kovskii from Securinega suffrutkosa (Pall.) Rehder during their work on the plants of Russian Far East. Its molecular ftirmula was estabhshed as CisHjsNOa. In addition, Soviet researchers determined the presence of a lactone moiety and extended conjugation by IR and UV spectroscopy. Further analysis of the structural information predicted the absence of N-methyl, O-methyl, hydroxyl, methylenedioxy, or ketone groups. Despite its unknown structure, 1 was approved for medical use in the USSR as a substitute of imported strychnine (see Section 8.1). The patents on its isolation, its dihydro and tetrahydro derivative, and various quaternary salts followed. Later, the structure of securinine (1) was simultaneously elucidated... 

Hydrolysis readily diminishes the lifetime of synthetic and natural polyesters. Scheme 3 shows the alkaline hydrolysis of poly(P-hydroxybutyrate) (PHB), the natural polyester belonging to the group polyhydroxyalkanoates (PHA), produced by micro-organisms which has application in above all medical materials [4]. The degradation product is often P-hydroxybutyric acid and when this reaction occurs in the human system, predominantly in the mitochondria, the compound is sometimes referred to as a ketone body (medical term, which is not related to the chemical term ketone). P-hydroxybutyrate is, together with other compounds, the fuel of respiration and a quantitatively important source of energy for micro-organisms. 

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