Quantitative Magnetic Resonance Imaging of Human Brain Development: Ages 4-18

Brain magnetic resonance images (MRI) of 104 healthy childrenand adolescents, aged 4–18, showed significant effectsof age and gender on brain morphometry. Males had larger cerebral(9%) and cerebellar (8%) volumes (P < 0.0001 and P = 0.008.respectively), which remained significant even after correctionfor height and weight After adjusting for cerebral size, theputamen and globus pallidus remained larger in males, whilerelative caudate size was larger in females. Neither cerebralnor cerebellar volume changed significantly across this agerange. Lateral ventricular volume increased significantly inmales (trend for females), with males showing an increase inslope after age 11. In males only, caudate and putamen decreasedwith age (P = 0.007 and 0.05, respectively). The left lateralventricles and putamen were significantly greater than the rightP = 0.01 and 0.0001, respectively). In contrast, the cerebralhemispheres and caudate showed a highly consistent right greater-than-leftasymmetry (P < 0.0001 for both). All volumes demonstrateda high degree of variability. These findings highlight gender-specificmaturational changes of the developing brain and the need forlarge gender-matched samples in pediatric neuropsychiatric studies.     

氯仿重结晶棉酚的质量研究

报道了氯仿重结晶的棉酚的化学性质,样品在不同温度下干燥恒重后,经熔点、薄层层析、紫外光谱、红外光谱、X-射线衍射、热重量分析、元素(C,H,Cl)分析及棉酚合量测定等一系列的分析,确证了在60℃以下棉酚与氯仿成溶剂化物(solvate)。随着干燥温度的升高或在室温长时间的贮存,此现象逐渐消失,100℃真空干燥恒重后成为纯棉酚。     

A 2-year prospective follow-up study of children and adolescents with disruptive behavior disorders. Prediction by cerebrospinal fluid 5-hydroxyindoleacetic acid, homovanillic acid, and autonomic measures?

A 2-year prospective follow-up study of 100% (N = 29) of a sample of children and adolescents with disruptive behavior disorders found that the baseline lumbar cerebrospinal fluid monoamine metabolite concentration and autonomic nervous system activity predicted some subsequent outcomes. The 5-hydroxyindoleacetic acid concentration significantly predicted severity of physical aggression during follow-up. The skin conductance level significantly predicted institutionalization. Correlations were in predicted directions with lower cerebrospinal fluid 5-hydroxyindoleacetic acid concentrations and autonomic activity correlated with poor outcome. Moreover, in multivariate analyses, which included nonlaboratory measures as predictors, cerebrospinal fluid and autonomic measures still contributed significantly to the prediction. However, hypothesized predictions of cerebrospinal fluid 5-hydroxyindoleacetic acid concentrations for suicide attempts and of low autonomic nervous system activity for arrests were not supported thus far. Patients are still at risk; consequently, these results must be considered preliminary. Nonetheless, the results suggest that further investigation of relationships between biological factors and outcome of children with disruptive behavior disorders is warranted.     

The effect of methylphenidate on urinary catecholamine excretion in hyperactivity: a partial replication

Children with attention deficit disorder with hyperactivity were treated with methylphenidate HCl (0.74 +/- 0.2 mg/kg/day) for 2 weeks in an open trial to assess changes in the urinary excretion of catecholamines and behavior. The purpose of this study was to confirm earlier work that methylphenidate has a distinctly different effect on urinary 3-methoxy-4-hydroxyphenylglycol (MHPG) excretion as compared to earlier studies with dextroamphetamine. Results confirmed the earlier finding that methylphenidate does not significantly change urinary MHPG excretion. No significant relationship was found between behavioral change and any of the urinary catecholamines or metabolites measured.     

Concentration gradient of CSF monoamine metabolites in children and adolescents

Whether the lumbar cerebrospinal fluid (CSF) concentration gradient of monoamine metabolites found in adults is influenced by age or pubertal status was studied in 26 children ranging from 6.5 to 17.3 years of age. Homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) were assayed by high-power liquid chromatography (HPLC) with electrochemical detection. Eight patients were prepubertal (Tanner stage I). The slopes in units of picomoles/milliliter/milliliter for regression lines for CSF monoamine metabolite concentrations versus milliliter of CSF collected were 5.07 +/- 0.65, 10.13 +/- 2.0, and 0.67 +/- 0.22 for 5-HIAA, HVA, and MHPG, respectively, for the group as a whole. Significant correlations with age, height, weight, or Tanner stage were not found for the HVA or MHPG concentration gradients. Tanner stage and 5-HIAA slope were significantly correlated. Three of eight prepubertal patients had nonsignificant 5-HIAA gradients. CSF studies in pediatric populations must control for aliquot collected, as the size of the gradient could produce differences sufficient to mimic a "positive" clinical study if the aliquots collected are not the same.     

Human fibroblast tissue factor is inhibited by lipoprotein-associated coagulation inhibitor and placental anticoagulant protein but not by apolipoprotein A-II

Studies of proteins that inhibit tissue factor activity have generally been conducted using either an extracted tissue homogenate ("thromboplastin") or tissue factor protein reconstituted into phospholipid vesicles rather than with tissue factor expressed in cell membranes (its physiological environment). In the present study, a human fibroblast cell strain was used to evaluate the effects of lipoprotein associated coagulation inhibitor (LACI), placental anticoagulant protein (PAP), and apolipoprotein A-II (apo A-II) on human tissue factor in cell membranes. LACI was tested from 7.8 to 500 pmol/L on fibroblasts cultured at cell densities ranging from 3,500 to 9,925 cells/well, and caused a progressive inhibition of tissue factor activity. PAP was tested from 3.9 nmol/L to 1 mumol/L at cell densities ranging from 4,500 to 15,400 cells/well and caused up to 83% inhibition of tissue factor activity. Inhibition by these proteins appeared to be influenced by cell density as well as whether the cells were intact or disrupted. Apo A-II, up to 1 mumol/L, did not inhibit the tissue factor activity of intact or disrupted fibroblasts at any cell density examined even though it did inhibit the activity of tissue factor in phospholipid vesicles. Of these inhibitors of tissue factor-dependent activation of factor X, LACI was the most effective in suppressing the generation of factor Xa activity. The effects obtained with apo A-II are clearly dependent on the nature of the tissue factor preparation with which it is tested. The disparity between the inhibitory effect of apo A-II on the activity of tissue factor reconstituted into lipid vesicles and the absence of effect on the activity of tissue factor remaining in cell membranes serves to reemphasize the necessity of reexamining results obtained with model systems using as nearly physiological reagents as possible.