Glucose defect

In the area of consumer products, amperometric glucose sensors hold high potential. Industrially, process monitors for the manufacture of consumer chemicals are under development. However, replacement of defective reference electrodes, which in a laboratory environment may be trivial, may be prohibitively difficult m vivo or in an industrial process environment. 

Genetic deficiency of glucose-6-phosphate dehydrogenase, with consequent impairment of the generation of NADPH, is common in populations of Mediterranean and Afro-Caribbean origin. The defect is manifested as red cell hemolysis (hemolytic anemia) when susceptible individuals are subjected to oxidants, such as the an-timalarial primaquine, aspirin, or sulfonamides or when... 

The entry rate of glucose into red blood cells is far greater than would be calculated for simple diffusion. Rather, it is an example of facilitated diffiision (Chapter 41). The specific protein involved in this process is called the glucose transporter or glucose permease. Some of its properties are summarized in Table 52-3-The process of entry of glucose into red blood cells is of major importance because it is the major fuel supply for these cells. About seven different but related glucose transporters have been isolated from various tissues unlike the red cell transporter, some of these are insidin-dependent (eg, in muscle and adipose tissue). There is considerable interest in the latter types of transporter because defects in their recruitment from intracellular sites to the surface of skeletal muscle cells may help explain the insulin resistance displayed by patients with type 2 diabetes mellitus. 

DM is characterized by a complete lack of insulin, a relative lack of insulin, or insulin resistance. These defects result in an inability to properly use glucose for energy. DM affects an estimated 20.8 million persons in the United States, or 7% of the population. While an estimated 14.6 million persons have been diagnosed, another 6.2 million people who have DM are unaware they have the disease. Worldwide, the number of people with DM is expected to rise to 35% by the year 2025.1... 

B9. Baronciani, L., Zanella, A., Bianchi, P Zappa, M Alfinito, E, Iolascon, A., Tannoia, N., Beutler, E., and Sirchia, G., Study of the molecular defects in glucose phosphate isomerase-deficient patients affected by chronic hemolytic anemia. Blood 88,2306-2310 (1996). 

Liu, J.C., Anand, M. and Roberts, C.B. (2006) Synthesis and extraction of beta-D-glucose-stabilized Au nanoparticles processed into low-defect, wide-area thin-films and ordered arrays using CO2-expanded liquids. Langmuir, 22 (9), 3964-3971. 

Several mutant strains of R. eutropha that were made to possess defective competing metabolic pathways with the PHA biosynthetic pathway were developed for the enhanced PHA production. The isocitrate dehydrogenase leaky mutant of R. eutropha accumulated P(3HB) more favorably at a lower car-bon/nitrogen molar ratio and at a lower carbon concentration than the parent strain [82]. In batch culture, the final cell and P(3HB) concentrations, and P(3HB) yield on glucose were slightly increased. Also, in the P(3HB-co-3HV) biosynthesis, the molar fraction of 3HV and the 3HV yield on propionic acid increased due to the enhanced conversion of propionic acid to 3-hydroxyvaleryl-CoA rather than to acetyl-CoA and C02 in this mutant. Another mutant R. eu-... 

In the 1930s, Peters and co-workers showed that thiamine deficiency in pigeons resulted in the accumulation of lactate in the brainstem [ 15]. Furthermore, they showed that the addition of small quantities of crystalline thiamine to the isolated brainstem tissue from thiamine-deficient birds in vitro resulted in normalization of lactate levels. These findings led to the formulation of the concept of the biochemical lesion in thiamine deficiency. Subsequent studies showed that the enzyme defect responsible for the biochemical lesion was a-KGDH rather than pyruvate dehydrogenase (PHDC), as had previously been presumed. a-KGDH and PHDC are major thiamine diphosphate (TDP)-dependent enzymes involved in brain glucose oxidation (Fig. 34-4). 

Defective transport of glucose across the blood-brain barrier is caused by deficiency in the glucose transporter protein 703... 

Another class of carbohydrate and fatty acid metabolism disorders is caused by systemic metabolic defects that affect the brain. Glucose-6-phosphatase deficiency (glycogenosis type I, Von Gierke s disease)... 

De Vivo, D. C., Trifiletti, R. R., Jacobson, R. I., Ronen, G. M., Behmand, R. A. and Harik, S. I. Defective glucose transport across the blood-brain barrier as a cause of persistent hypo-glycorrhachia, seizures, and developmental delay. N. Engl. J. Med. 325 703-709,1991. 

Hemolytic anemia results from decreased RBC survival time due to destruction in the spleen or circulation. The most common etiologies are RBC membrane defects (e.g., hereditary spherocytosis), altered Hb solubility or stability (e.g., sickle cell anemia [see Chap. 34] and thalassemias), and changes in intracellular metabolism (e.g., glucose-6-phosphate dehydrogenase deficiency). Some drugs cause direct oxidative damage to RBCs (see Appendix 3). 

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