MR-Intracranial pressure (ICP): a method to measure intracranial elastance and pressure noninvasively by means of MR imaging: baboon and human study

PURPOSE: To develop a noninvasive method for intracranial elastance and intracranial pressure (ICP) measurement. MATERIALS AND METHODS: Intracranial volume and pressure changes were calculated from magnetic resonance (MR) imaging measurements of cerebrospinal fluid (CSF) and blood flow. The volume change was calculated from the net transcranial CSF and blood volumetric flow rates. The change in pressure was derived from the change in the CSF pressure gradient calculated from CSF velocity. An elastance index was derived from the ratio of pressure to volume change. The reproducibility of the elastance index measurement was established from four to five measurements in five healthy volunteers. The elastance index was measured and compared with invasive ICP measurements in five patients with an intraventricular catheter at MR imaging. False-positive and false-negative rates were established by using 25 measurements in eight healthy volunteers and six in four patients with chronically elevated ICP. R:ESULTS: The mean of the fractional SD of the elastance index in humans was 19.6%. The elastance index in the five patients with intraventricular catheters correlated well with the invasively measured ICP (R:(2) = 0.965; P: <.005). MR imaging-derived ICPs in the eight healthy volunteers were 4.2-12.4 mm Hg, all within normal range. Measurements in three of the four patients with chronically elevated ICP were 20.5-34.0 mm Hg, substantially higher than the normal limit. CONCLUSION: MR imaging-derived elastance index correlates with ICP over a wide range of ICP values. The sensitivity of the technique allows differentiation between normal and elevated ICP.     

Hemodynamics of in-tandem stenosis of the internal carotid artery: when is carotid endarterectomy indicated?

BACKGROUND: Recent publications have pointed out the importance of evaluating patients with in-tandem stenosis and in particular the association of moderate stenosis of the extracranial internal carotid artery (ICA) with moderate or severe stenosis of the intracranial internal carotid artery. Such evaluations are needed in symptomatic patients before planning carotid endarterectomies because observations have shown that in some cases the removal of an extracranial lesion does not necessarily improve these symptoms. This paper examines the hemodynamic effects of in-tandem stenosis in the internal carotid artery. METHODS: Equations describing flow in arteries are modified to accommodate two regions of stenosis in tandem. An equivalent value of stenosis is derived such that two stenoses in tandem behave as a single stenosis with similar hemodynamic properties. The solution to this problem is solved mathematically and this was used to analyze the observations made in five studies published on in-tandem stenosis of the internal carotid artery. RESULTS: Equivalent stenoses for various values of extracranial and intracranial stenoses are presented. It was found that two stenotic lesions in tandem are not equivalent to a simple summation of both values. A graphical solution is presented to show the hemodynamic effects of both stenoses. CONCLUSIONS: The most critical determinant of hemodynamic compromise when two lesions are in tandem is the larger one. Hence removal of a more proximal lesion may have little effect on a larger distal lesion if the symptoms are due to hypoperfusion. It is important that one distinguish between hypoperfusion and thromboembolic causes of the symptoms. No conclusions about the risk of thromboembolic events after a carotid endarterectomy in the setting of a distal stenosis can be made from this study.     

Untersuchung zur Reliabilität und Validität der dreidimensionalen Funktionsanalyse des Kiefergelenks

Background

Movement disorders are concluded responsible for pain and temporomandibular dysfunction. No uniform standards have been established yet for functional analysis of the temporomandibular joint. Especially, there is a lack of evidence in terms of psychometric criteria of such measurements. The aim of this study was to evaluate the reliability and validity of a three-dimensional motion analysis of temporomandibular joint in healthy subjects.

Material and methods

30 healthy subjects (15 females and 15 males) aged between 18 and 40 years volunteered for the study. A physical examination as well as three repetitions of a 3D motion analysis of the temporomandibular joint were performed using ultrasound-propulsion based Zebris equipment. The whole procedure was repeated after seven days. ICC was calculated for reliability and Pearsons correlation coefficient for convergent validity of the apparative procedure as compared with the manual examination.

Results

Intrasession as well as intersession reliability was found very good (greater 0.8) for all movement directions. No substantial differences were found between the intra- and intersession reliability. Further high correlation’s were found between the manual examination and the 3D motion analysis in all parameters with exception of the maximal opening distance.

Discussion

Due to unique equipment used the results are barely comparable with other results reported yet. Motivation of the volunteers as well as pain avoidance strategy during maximal mouth opening performed very rarely in the daily living could be responsible for the low validity of this parameter.

Conclusions

The 3D movement analysis is a highly reliable and valid instrument for evaluating function of the temporomandibular joint. The measurement objectivity seems to be also high as indicated by the low difference between the intrasession and intersession reliability. Further research is needed to evaluate the psychometric quality of the method in patients suffering from temporomandibular dysfunction.     

Evidence for a putative bipolar disorder locus on 2p13-16 and other potential loci on 4q31, 7q34, 8q13, 9q31, 10q21-24, 13q32, 14q21 and 17q11-12

Bipolar disorder (BP) is a severe and common psychiatric disorder characterized by extreme mood swings. Family, twin and adoption studies strongly support a genetic component. The mode of inheritance is complex and likely involves multiple, as yet unidentified genes. To identify susceptibility loci, we conducted a genome-wide scan with 343 microsatellite markers in one of the largest, well-characterized pedigree samples assembled to date (373 individuals in 40 pedigrees). To increase power to detect linkage, scan statistics were used to examine the logarithm of odds (lod) scores based on evidence at adjacent chromosomal loci. This analysis yielded significant evidence of linkage (genome-wide P&<0.05) for markers on 2p13-16. Standard linkage analysis was also supportive of linkage to 2p13-16 (lod=3.20), and identified several other interesting regions: 4q31 (lod=3.16), 7q34 (lod=2.78), 8q13 (lod=2.06), 9q31 (lod=2.07), 10q24 (lod=2.79), 13q32 (lod=2.2), 14q21 (lod=2.36) and 17q11-12 (lod=2.75). In this systematic, large-scale study, we identified novel putative loci for BP (on 2p13-16, 8q13 and 14q21) and found support for previously proposed loci (on 4q31, 7q34, 9q31, 10q21-24, 13q32 and 17q11-12). Two of the regions implicated in our study, 2p13-14 and 13q32, have also been linked to schizophrenia, suggesting that the two disorders may have susceptibility genes in common.     

Investigation of the oxidation mechanism of hydroxypyridones and synthesis of some hydroxy-methylpyridones

Investigation of the Oxidation Mechanism of Hydroxypyridones and Synthesis of Some Hydroxy-methylpyridones 3- and 5-hydroxypyridone-(2) are not oxidized in water-free solvents; one molecule of water per molecule of hydroxypyridone is used up during oxidation. A reversible hydroquinone-quinone-system does not appear during the first phase of the reaction. 6-Methyl-hydroxypyridones are not oxidized. A covalent hydration of the hydroxypyridones in the absence of oxidizing agents could not be detected. A reaction mechanism is discussed. – The syntheses of 5-hydroxy-6-methylpyridone-(2), 5-hydroxy-4,6-dimethylpyridone-(2), 3-hydroxy-6-methylpyridone-(2) and 3-hydroxy-4,6-dimethyl-pyridone-(2) are described.     

New synthesis of 2-acyloxyimino-coumaranones

A New Synthesis of 2-Acyloxyimino-coumaranones The reaction of acetic anhydride with o-hydroxy-β-nitro-acetophenone does not yield 2-methyl-3-nitro-chromone, but 2-acetoxyimino-coumaranone (2-acetoxyimino-2,3-dihydrobenzofuranone-3). Other acid anhydrides give the same reaction; 2-benzoyloxyimino-, 2-veratroyloxyimino-and 2-(3,4-dibenzyloxy-benzoyloxyimino)-coumaranone were synthesized. Their degradation reactions and mass spectrometric fragmentations are discussed.     

The myocardiopathies of glycogenosis]

Thirty-three patients with glycogen abnormalities and myocardial disease were studied. 27 of them has type II glycogen disorders (Pompe's disease, with an intralysozymal deficit of acid maltase) and 6 with type III glycogen disorders Forbes disease, with a deficit in amylo-1-6-glucosidase). The picture of a type II abnormality in the infant is very standard: early onset, often neonatally; the association with asystole and muscular hypotonia and a characteristics clinical picture; invariable cardiomegaly and typical ECG findings (short PR interval, high voltage complexes). Death occurs before one year of age, treatment has limited effect, and attention is centred on the early discovery of heterozygotes and of diagnosis antenatally. The possibility of an obstructive type (4 out of 24) and a type with endocardial fibroelastosis (3 out of 24) must be emphasised. In the late onset myopathic form of type II disorder (3 cases), involvement of the myocardium is always found, but is of secondary importance in determining the clinical picture and natural history. The same can be said of type III disorders in which, despite the infrequency of asystole or significant cardiomegaly, a hypertrophic cardiomyopathy which may be obstructive can lead to sudden death in infancy (2 cases out of 6).     

Über die Oxydation einiger Hydroxypyridine,insbesondere des 2,5-Dihydroxypyridins

Oxidation of Hydroxy Pyridines, specially 2,5-Dihydroxypyridine The three monohydroxypyridines are not oxidized by peroxidase and hydrogen peroxide. Further, the six isomeric dihydroxypyridines were investigated: 4-hydroxy-pyridone-(2) is not attacked by peroxidase; on the other hand 5-hydroxy-pyridone-(2) and 6-hydroxypyridone-(2) are very easily oxidized forming intensively coloured intermediary compounds. From the oxidation of 5-hydroxy-pyridone-(2), two intermediates were isolated and identified as 2,2′,5,5′-tetrahydroxy-dipyridyl-(6,6′) and 2,2′,5,5′-tetrahydroxy-3,3′-diaza-diphenoquinone-(4,4′) or its tautomeric forms.