Brain stem, lead levels

The neonate is at risk for kemicterus if the serum unconjugated bilirubin level is higher than 17 mg/dL. Kemicterus is characterized by yellow staining of clusters of neuronal cell bodies in the basal ganglia, cerebellum, and brain stem, leading to motor and cognitive deficits or death. Immaturity and f)erhaps hypoxia make the blood-brain barrier permeable to bilirubin and contribute to the likelihood of kemictems. The biochemical basis of bilirubin encephalopathy is due to many causes inhibition of RNA and protein synthesis, carbohydrate metabolism (both cAMP-mediated and Ca " -activated), phospholipid-dependent protein kinases, enzymes involved in the electron transport system, and impaired nerve conduction. 

Blockade of the NET, eg, by the nonselective psychostimulant cocaine or the NET selective agents atomoxetine or reBoxetine, impairs this primary site of norepinephrine removal and thus synaptic norepinephrine levels rise, leading to greater stimulation of a and 3 adrenoceptors. In the periphery this effect may produce a clinical picture of sympathetic activation, but it is often counterbalanced by concomitant stimulation of k2 adrenoceptors in the brain stem that reduce sympathetic activation. 

Kallikrein is a proteinase enzyme, which converts kininogen to vasodilative kinin peptides. The human tissue kallikrein gene, in the form of naked pDNA (CMV-cHK), was directly delivered by intracerebroventricular injection into hypertensive rats. The expression of human tissue kallikrein protein was identified in the cortex, cerebellum, brain stem, hippocampus, and hypothalamus of the treated rats. The expression level and its effect could lead to understanding the role of vasodilative KKS on the pathogenesis of hypertension. 

Catecholamine levels in the obese-infected mice were reduced significantly in forebrain, but not in the brain stem (Lyons et al., 1982). In substantia nigra, CDV infection downregulates tyrosine hydroxylase (TH), the rate-limiting enzyme of dopamine synthesis, which leads to motor impairment of infected animals (Bencsik et al., 1996). 

Cohen, D.J., Johnson, W.T. and Caparulo, B.K. (1976). Pica and elevated blood lead level in autistic and atypical children. Am. J. Dis. Child., 130, 47-48 Coss, R.G. and Glohus, A. (1978). Spine stems on tectal intemeurons in jewel fish are shortened by social stimulation. Science (Washington, DC), 200, 787-790 Cumings, J.N. (1959). Heavy Metals and the Brain. Part 3 Lead, pp. 93-155. (Springfield, IL Thomas)... 

Did the eccentricities of the great artists stem from their being victims of low-level poisoning Lead and mercury are well known to affect the brain. Given the skills of today s forensic chemists it might one day be possible to reveal more about the great painters themselves provided we can find at least a strand of their hair or some part of their remains. 

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