A-Acetyl aspartate

FIND Fagerstrom test for nicotine dependence NR not reported NA not applicable NAA A -acetyl-aspartate Glu glutamate Gin glutamine Cho choline ... 

CBF, Cerebral blood flow CCAo, common carotid artery occlusion cGMP, cyclic guanine monophosphate ICAM-1, intercellular adhesion molecule-1 ICAo, internal carotid artery occlusion MCAo, middle cerebral artery occlusion NAA, A-acetyl-aspartate NOS, nitric oxide synthase SD, Sprague-Dawley SH, spontaneously hypertensive SOD, superoxide dismutase TUNEL, transferase dUTP nick-end labeling. 

Using long TEs, the signal from most metabolites in the brain is lost, except that of choline (Cho), creatine (Cr), A -acetyl aspartate (NAA) and lactate (Miller, 1991). Conversely, short TEs allow for identification of many other metabolites (e.g., myoinositol, glutamate, glutamine and glycine). 

A/-acetyl aspartate NAA 2.0 and 2.05 Largest peak in normal spectra Marker for functional neurons (reflects neuronal and axonal integrity) Increases with age Decreases in most cerebral insults, including degenerative diseases Decreases in hypothyroidism Increases only in Canavan disease... 

Recently, Yekkala et al. [144,145] have proposed an HPLC method with fluorescence detection. The method involves a rather laborious sample preparation due to the peculiar nature of the substrate involved (teeth), including pulverization, demineralization, hydrolysis of dentin and derivati-zation with o-phthaldialdehyde and A-acetyl-L-cysteine in order to obtain the enantioseparation of aspartic acid. Using a similar procedure, Benesova et al. [146] found that, in comparison with GC, HPLC provides shorter analysis time and higher sensitivity. 

Moore, G.J., Bebchuk, J.M., Hasanat, K., Chen, G., Seraji-Bozorgzad, N., Wilds, I.B., Faulk, M.W., Koch, S., Glitz, D.A., Jolkovsky, L., and Manji, H.K. (2000b) Lithium increases5N-acetyl-aspartate in the human brain in vivo evidence in support of bcl-2 s neurotrophic effects Biol Psychiatry 48 1-8. 

D., and Ketter, T.A. (2000) Decreased dorsolateral prefrontal N-acetyl aspartate in bipolar disorder. Biol Psychiatry 47 475 81. 

Magnetic resonance spectroscopy studies of COS patients revealed decreases in the ratio of N-acetyl aspartate to creatine (a putative marker of neuronal density) in the frontal cortex (Thomas et ah, 1998) and hippocampus (Bertolino et ah, 1998). These results were similar in direction and extent to those seen in adult patients. 

A magnetic resonance spectroscopy (MRS) study examined correlates of repetitive violence in 13 mildly mentally retarded individuals and 14 controls (Critch-ley et al., 2000). Concentrations and ratios of N-acetyl aspartate (NAA) and creatine phosphocreatine (Cr-l-PCr) were assayed. The NAA and CR-I-CR concentrations reflect neuronal density and high-energy phosphate metabolism, respectively. Violent patients had lower prefrontal concentrations of NAA and Cr-l-PCr and a lower NAA/Cr-l-PCr ratio in the amyg-dalohippocampal complex than that in controls. Within the violent group, prefrontal NAA concentration correlated with aggression frequency. 

Fig. 4.15. Perfusion images (PI) and spectroscopic imaging maps of lactate and N-acetyl-aspartate (NAA) before and after embolic occlusion of the middle cerebral artery. Thrombolysis was applied 1.5 h after embolism and lead to a partial reperfusion of the affected territory (upper row). There was a clear increase in lactate that was partially reversed upon thrombolytic reperfusion. NAA maps showed a decreased signal in the ischemic hemisphere that did not recover. [Reproduced with permission from Franke et al. (2000)]...

Callicott JH, Egan MF, Bertolino A, Mattay VS, Langheim FJ, et al. 1998. Hippocampal N-acetyl aspartate in unaffected siblings of patients with schizophrenia A possible intermediate neurobiological phenotype. Biol Psychiatry 44 941 -950. 

Clark JB. 1998. N-acetyl aspartate A marker for neuronal loss or mitochondrial dysfunction. Dev Neurosci 20 271-276. 

Stanley JA, Vemulapalli M, Nutche J, Montrose DM, Sweeney JA, et al. 2007. Reduced N-acetyl-aspartate levels in schizophrenia patients with a younger onset age A singlevoxel lh spectroscopy study. Schizophr Res 93 23-32. 

Fig. 23.2. Axial T2-weighted image showing location of a spectroscopy voxel over the posterior limb of the internal capsule of each hemisphere together with the spectra obtained from the right and left internal capsules of a patient with subcortical stroke (Pendlebury et at. 1999). The N-acetyl aspartate (NAA) peak is reduced on the side of the affected right hemisphere consistent with damage to the descending motor pathways.

C2- and D2-symmetric dioxatetraaza 18-membered macrocycles such as 14 and 15 have been prepared by a chemoenzymatic method involving ( )-fraiw-diaminocyclohexane as starting material (eq 26). Good enantiomeric discrimination was observed with tetraprotonated species (/ ,/ )-14 and the D-enantiomer of N-acetyl aspartate. 

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