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[Delayed postanoxic encephalopathy].

We report the case of a 9-year-old boy with delayed postanoxic encephalopathy. The patient improved after a period of coma and adult respiratory distress syndrome caused by benzodiazepine intoxication. Initial improvement appeared to be complete, but 9 days after discharge from the pediatric intensive care unit, extrapyramidal rigidity of the left arm became manifest. This event was followed by progressive neurologic impairment with involuntary, non-repetitive, but occasionally stereotyped movements, affecting distal, proximal and axial musculature in various combinations. On physical examination, passive movement of the left arm showed a plastic, lead-pipe rigidity with a ratchet-like cogwheel quality. Magnetic resonance imaging (MRI) was performed. Axial T 2 -weighted images of the brain showed characteristic signs of an ischemic area in the basal ganglia which were more evident in the right region, a finding consistent with anoxic-ischemic encephalopathy. Delayed postanoxic encephalopathy is a relatively uncommon and unexplained phenomenon which becomes manifest after an initial hypoxic-ischemic event that causes stupor or coma. The pathogenesis is unknown. Exceptionally, this syndrome can affect the basal ganglia more than the cerebral cortex and white matter. Initial improvement is followed after a variable period of time by relapse, progressing for weeks to months until the patient is left with permanent sequelae.

Child↗

Proportion of cells with paternal 11p15 uniparental disomy correlates with organ enlargement in Wiedemann-beckwith syndrome.

"Genetic mosaicism" describes the presence of two or more populations of cells within a single individual that differ in their genomic constitution. Although the occurrence of asymmetric overgrowth in Wiedemann-Beckwith syndrome (WBS) suggests that mosaicism has some role in the WBS phenotype, no direct evidence for this has been published. WBS is a congenital overgrowth syndrome with variable phenotype linked to the imprinted gene cluster on chromosome region 11p15. We have performed a molecular survey of multiple organs and tissues in a case of WBS with a high degree of mosaic paternal 11p15 uniparental disomy (UPD). The organs most severely affected were those with the highest percentage of cells with UPD. In particular there was a striking difference in the degree of mosaicism for 11p15 UPD between the extremely enlarged left adrenal and non-enlarged right adrenal gland. This result indicates that the proportion of paternal 11p15 UPD cells correlates with the tissue phenotype of WBS. Our results suggest that high proportions of abnormal cells result from a combination of stochastic events and cell selection. Mosaicism may explain the variable phenotypes including hemihyperplasia and predisposition to childhood cancers in WBS patients.

Adrenal Glands↗

The boundaries and copy numbers of Ti plasmid T-DNA vary in crown gall tumors.

The Ti plasmid DNA maintained in octopine-type crown gall tumor lines is variable, but always includes at least part of the Ti plasmid that maps over the region of Hind III fragment 1 of pTiB6-806. The right-hand boundary of transferred DNA (T-DNA) varies considerably among the three independent tumor lines examined; the left boundary was not located definitively. The T-DNA of two sibling clones of the same tumor line, E1 and E9, appears identical. The copy number of T-DNA in E9 tumor DNA appears higher for the right end (about 30 copies) than for the left end (approximately 1 copy).

Cell Line↗

[The time of eruption of the milk teeth in Down's disease].

In the literature, the time of emergence of milk teeth in patients with Down's disease is reported to be delayed. However, only a few authors can document this observation in controlled studies. This occasioned a fresh analysis of the time and sequence of the milk dentition. In 93 babies and infants with Down's disease, the time of emergence of 842 milk teeth was recorded. In the statistical analysis, mean and standard deviations were calculated: by means of analysis of variance, left-right differences and sex differences were tested. There are the following results: the emergence of milk teeth begins with an average time delay of six months. The first milk molars frequently emerge as the first or second tooth. Sex differences and differences between right and left with regard to the emergence of milk teeth cannot be demonstrated. Overall, the sequence of emergence is very variable. The delayed emergence of milk teeth must be regarded as a component of the general delay in development in Down's disease which in the region of the head affects both the growth of the jaw and the development of the motor activity of the mouth.

Aging↗

Differential enhancement of postischemic segmental systolic thickening by diltiazem.

Prolonged depression of segmental systolic thickening after brief coronary artery occlusion may result principally from events during reperfusion rather than during the ischemic interval. Thus, cellular calcium overload at reperfusion may be a mediator of contractile dysfunction after brief ischemia, and reduction of calcium entry by diltiazem, a calcium channel antagonist, may enhance recovery of systolic thickening after brief periods of ischemia. Thirteen awake unsedated dogs instrumented with hemodynamic catheters, left anterior descending coronary artery occluders and five to six pairs of intramyocardial sonomicrometers underwent two 15 min coronary artery occlusions with 24 h reperfusion. The order of infusion of diltiazem (15 micrograms/kg per min) or saline solution was alternated. Systolic thickening, hemodynamic variables and regional myocardial blood flow were measured serially over 24 h. Despite equally severe ischemic dysfunction during coronary occlusion, diltiazem-treated segments with systolic thinning during ischemia recovered control segmental thickening significantly earlier than saline solution-treated segments (at 30 versus 180 min of reperfusion). Blood pressure was mildly decreased during diltiazem treatment; therefore, a second group of 10 dogs underwent a similar occlusion and reflow period during infusion of nitroprusside to lower mean arterial pressure equivalently. Decreases in blood pressure in this group resulted in some improvement in segmental systolic function; however, this did not reach statistical significance at any time. Regional myocardial blood flows were similar in the saline solution- and diltiazem-treated groups during ischemia and reflow. Thus, it is concluded that 1) diltiazem infusion significantly enhanced recovery of segmental systolic thickening after 15 min of ischemia and 24 h of reperfusion; 2) the enhancement in segmental systolic function could not entirely be attributed to decreased mean arterial pressure; 3) improvement in postischemic segmental ventricular function was seen only in those segments with systolic thinning during ischemia; thus, segments with the most severe ischemic dysfunction benefited most; and 4) there were no important differences in regional myocardial blood flow during ischemia and reperfusion between saline- and diltiazem-treated animals.

Animals↗

Reliable detection of bilateral activation in human primary somatosensory cortex by unilateral median nerve stimulation.

In non-human primates, a bilateral representation of unilaterally presented somatosensory information can be found at the lowest level of cortical processing as indicated by the presence of neurons with bilateral receptive fields in the hand region of primary somatosensory (SI) cortex. In humans, such bilateral activation of SI is considered controversial due to highly variable detection rates for the much weaker ipsilateral response across different studies (ranging from 3% to 100%). Second-order blind identification (SOBI) is a blind source separation algorithm that has been successfully used to isolate neuronal signals from functionally distinct brain regions, including the left- and right-SI. SOBI-aided extraction of left- and right-SI responses to median nerve stimulation from high-density EEG has been previously validated against the fMRI and MEG literature. Here, we applied SOBI to EEG data and examined whether relatively weaker ipsilateral activations could be reliably detected across subjects. In single subject analysis, statistically significant somatosensory evoked potentials (SEPs) in response to unilateral stimulation were detected from both SI contralateral to and SI ipsilateral to the side of stimulation. Furthermore, these ipsilateral responses were observed in both the left and right hemispheres of all 10 subjects studied. Together these results demonstrate that unilateral stimulation of the median nerve, whether applied to the left or right wrist, can activate both the left- and right-SI, raising the possibility that in humans, unilateral sensory input may be bilaterally represented at the lowest level of cortical processing.

Adult↗

[Spatio-temporal organisation of EEG in sleep stages (author's transl)].

The purpose of this study was to test the hypothesis of the existence and independence of multiple generators of the sleep rhythms. Spatio-temporal analysis of the sleep EEG of 6 subjects was realised both visually and by multi-dimensional analysis of the parameters of spectral power (PS) and coherence (CH). Four results have been demonstrated: a relative decrease of the global CH during the transition from waking to deep sleep, with reappearance of high CH during paradoxical sleep (PS); (2) a negative correlation between the activities of frontal and occipital regions, mostly for alpha and theta frequencies; (3) a dominance of the activity of one hemisphere (the left here) during sleep, with a possible change of this dominance during paradoxical sleep; (4) a slow oscillation of power (SOP) with a periodicity of 1-5 min. variable according to subjects and sleep stages. These results suggest the existence of two partially independent groups of generators (anterior and posterior) for the slow frequencies of sleep.

Electroencephalography↗

Folbos, a new foldback element in rice.

A new class I foldback element, Folbos, has been discovered in O. sativa L. Its long terminal inverted repeats (IVRs) are 303 and 331 bp long and the left one encodes a short open reading frame of 76 codons. The IVRs consist of inner and outer domains, the latter built up of 6 tandem repeats of about 30 bp each. The central region is represented by 90 bp conservative stretch adjacent to a variable length (19-33 bp) A-tail, which in most cases includes the sequence 5'-TGACTT-3'. Folbos targets AT-rich regions and the insertion results in 7 bp target site duplications. Half of the copies found in annotated sequences of O. sativa japonica cv. Nipponbare are positioned in close proximity to (< 1kb) or within the transcribed regions, thus they have the potential to contribute to plant genome evolution.

Base Sequence↗

Perinatal gonadectomy exerts regionally selective, lateralized effects on the density of axons immunoreactive for tyrosine hydroxylase in the cerebral cortex of adult male rats.

The catecholamine innervation of the cerebral cortex is essential for its normal operations and is implicated in cortical dysfunction in mental illness. Previous studies in rats have shown that the maturational tempo of these afferents is highly responsive to changes in gonadal hormones. The present findings show that perinatal hormone manipulation also has striking, region- and hemisphere-specific consequences for cortical catecholamines in adulthood. The effect of perinatal gonadectomy on catecholamines was examined in representative sensory, motor, and association cortices of adult male rats by combining hormone manipulation with immunocytochemistry for tyrosine hydroxylase, a rate-limiting enzyme in catecholamine biosynthesis. Qualitative and quantitative comparison of immunoreactivity in rats perinatally gonadectomized or sham-operated revealed complex changes in gonadectomized subjects; in cingulate cortex, TH immunoreactivity was strongly and bilaterally diminished, in sensory and motor cortices, axon density was decreased in left hemispheres, but was minimally affected on the right, and in a premotor cortex, gonadectomy was without significant effect in either hemisphere. Corresponding analyses in gonadectomized rats supplemented with testosterone revealed a protective influence, albeit one in which TH immunoreactivity so showed regional and hemispheric variability in responsiveness to hormone replacement. These complex patterns of TH sensitivity suggest highly asymmetric hormone stimulation of cortical catecholamines. Such discriminative action may contribute to sex differences in the functional maturation and lateralization of the cortex and may also have bearing on disorders such as dyslexia, which show sexual dimorphisms, and in which functional laterality of the cortex may be particularly at issue.

Animals↗

Myocardial protection through cold cardioplegia using diltiazem, a calcium channel blocker.

During two hours of aortic clamping, two groups of 10 dogs each were given an intermittent infusion of a cold solution in the aortic root. In one group, the solution contained 20 mEq per liter of potassium chloride (KCl) and in the other, a calcium channel blocker (diltiazem). Left ventricular (LV) performance was measured by calculation of LV pressure, left ventricular end-diastolic pressure (LVEDP), cardiac index (CI), and stroke-work index (SWI). Regional myocardial function was assessed through ultrasonic crystals implanted in the subendocardial areas of both the left anterior descending (LAD) and circumflex coronary arteries. Dogs receiving KCl displayed deterioration of LV performance as evidenced by a return of maximal LV pressure, maximal rate of rise of LV pressure (dP/dtmax), CI, and SWI to 74 +/- 4%, 87 +/- 5%, 74 +/- 6%, and 59 +/- 6%, respectively, of the initial (before clamping) values. Animals that received diltiazem, on the other hand, had for the same variables a return to 85 +/- 4%, 99 +/- 7%, 129 +/- 8%, and 111 +/- 10% of the initial values. The rate of relaxation (peak negative dP/dt) decreased in both groups but less in dogs receiving diltiazem. Regional function in the area of the LAD and circumflex arteries showed little change in either group. We conclude that cold cardioplegia with a solution containing KCl or diltiazem protects the myocardium during prolonged ischemic cardiac arrest. Return of LV function on the whole is superior when diltiazem is used.

Animals↗

Use of myocardial tissue Doppler imaging for intraoperative monitoring of left ventricular function.

BACKGROUND: Detection of myocardial ischaemia during surgery is usually by assessment of regional wall motion using two-dimensional transoesophageal echocardiography (TOE). Tissue Doppler imaging (TDI) may assist this assessment and improve its accuracy. METHODS: We measured peak myocardial velocities in the anterior mid-wall of the left ventricle by TOE and pulsed-wave TDI in addition to transmitral flow velocity, two-dimensional echocardiography and cardiovascular variables. We studied 42 patients before and after coronary bypass surgery with left internal mammary artery grafts. RESULTS: Peak systolic and early and late diastolic velocity measurements of the anterior mid-wall were obtained in all patients. Variation between and within observers was small (<6%). Peak systolic thickening velocity correlated with visual assessment of anterior wall motion score, fractional area change of the left ventricle and left ventricular systolic wall stress. Because of the wide overlap of systolic velocity between the segments with normal and abnormal wall motion, it was not possible to separate normal from abnormal segments on the basis of TDI-derived velocity alone. The diastolic velocity in the anterior wall reflected the transmitral filling pattern. After surgery, the peak systolic and late diastolic anterior wall velocities increased (from 4.2 (95% confidence interval 4.0, 4.7) to 5.7 (4.8, 6.3) cm s(-1) and from 3.5 (3.2, 3.9) to 6.0 (5.1, 6.9) cm s(-1) respectively), while the ratio of early to late diastolic velocity decreased from 1.5 (1.2, 1.7) to 1.0 (0.8, 1.2). TDI changes characteristic of new myocardial ischaemia were not seen in any patient. CONCLUSION: Intraoperative measurement of TDI in the anterior wall of the left ventricle is feasible and provides additional quantitative information on both regional and global systolic and diastolic function. We found changes in myocardial velocities indicating improvement in the systolic and impairment in the diastolic function of the anterior wall of the left ventricle immediately after mammary artery grafting.

Aged↗

Regional variations of ultrasonic integrated backscatter in normal and myopathic left ventricles. A new multi-view approach.

The purpose of the present study was to determine whether the cyclic variation of integrated backscatter is measurable and quantifiable in all left ventricular walls and whether the information obtained using both parasternal and apical transducer positions can be used to identify changes in myocardial structure and contractility. The cyclic variation of integrated backscatter was measured from the parasternal long-axis, apical four-chamber and two-chamber views in 26 patients with idiopathic dilated cardiomyopathy (mean age 58 +/- 9 years; ejection fraction 29 +/- 10%) and compared with information obtained from 30 aged-matched healthy volunteers. For each subject, the cyclic variation of integrated backscatter was calculated from 16 predetermined regions-of-interest located within the myocardium of the basal and mid-segments of the left ventricle imaged from the long-axis view and also the basal mid and apical left ventricular segments imaged from the two apical views. The cyclic variation of integrated backscatter was found to be present in 100% of the analysed regions-of-interest in healthy volunteers and in 87.5% of the analysed regions-of-interest in patients with idiopathic dilated cardiomyopathy. The mean value of cyclic variation of integrated backscatter, averaged from all regions-of-interest in the idiopathic dilated cardiomyopathy group, was significantly reduced compared to that in the healthy volunteers group (3.2 +/- 2.5 dB [mean +/- SD] vs 4.8 +/- 2.9 dB, P < 0.0001). Additionally, the healthy volunteers group demonstrated marked regional variability in the magnitude of cyclic variation of integrated backscatter which closely followed the regional changes in the contractile function of the normal heart. These regional differences in the magnitude of the cyclic variation of integrated backscatter were only partially retained in the idiopathic dilated cardiomyopathy group, and suggest that a multi-view approach of the recording of cyclic variation of integrated backscatter can be of value to differentiate normal from myopathic myocardium and to quantify regional differences in myocardial contractile performance throughout the left ventricular walls.

Adult↗

Prefrontal cortex hemispheric specialization for categorical and coordinate visual spatial memory.

During visual spatial perception of multiple items, the left hemisphere has been shown to preferentially process categorical spatial relationships while the right hemisphere has been shown to preferentially process coordinate spatial relationships. We hypothesized that this hemispheric processing distinction would be reflected in the prefrontal cortex during categorical and coordinate visual spatial memory, and tested this hypothesis using functional magnetic resonance imaging (fMRI). During encoding, abstract shapes were presented in the left or right hemifield in addition to a dot at a variable distance from the shape (with some dots on the shape); participants were instructed to remember the position of each dot relative to the shape. During categorical memory retrieval, each shape was presented centrally and participants responded whether the previously corresponding dot was 'on' or 'off' of the shape. During coordinate memory retrieval, each shape was presented centrally and participants responded whether the previously corresponding dot was 'near' or 'far' from the shape (relative to a reference distance). Consistent with our hypothesis, a region in the left prefrontal cortex (BA10) was preferentially associated with categorical visual spatial memory and a region in the right prefrontal cortex (BA9/10) was preferentially associated with coordinate visual spatial memory. These results have direct implications for interpreting previous findings that the left prefrontal cortex is associated with source memory, as this cognitive process is categorical in nature, and the right prefrontal cortex is associated with item memory, as this process depends on the precise spatial relations among item features or components.

Adult↗

High count rate first-pass radionuclide angiography using a digital gamma camera.

In this study, first-pass radionuclide angiography (FPRNA) was performed using a digital single-crystal gamma camera. Twenty-nine men and six women (ages 43-80, mean 61 yr) underwent FPRNA in the supine position immediately prior to cardiac catheterization. Total counts/sec in the whole field-of-view in the right ventricular phase were 150,352 +/- 26,006. Background uncorrected counts in the representative cycle were 7,651 +/- 2,527 at end-diastolie and 4,904 +/- 2,314 at end-systolie. A linear correlation between FPRNA left ventricular (LV) ejection fraction and contrast LV ejection fraction gave an r = 0.95 with an s.e.e. of 0.05. Analyses of intra- and interobserver variability gave r = 0.99 and 0.98 and an s.e.e. of 0.02 and 0.03, respectively. Spearman-Rank correlation coefficients between FPRNA and contrast angiographic wall-motion scores were greater than 0.8 for all walls, while sensitivity/specificity were 0.86/0.90, 0.76/1.00, 0.76/1.00 for anterior, apical, and inferior wall-motion abnormalities, respectively. We conclude that satisfactory counting statistics for FPRNA can be obtained with a digital gamma camera, and that accurate and reproducible measurements of global and regional left ventricular function can be obtained with this technique.

Adult↗

Edematogenic and myotoxic activities of the Duvernoy's gland secretion of Philodryas olfersii from the north-east region of Argentina.

Philodryas olfersii is found in South America, from Amazonas to Patagonia. It is important to characterize the venom of P. olfersii, who inhabits the North-East region of Argentina, since snake venoms are known to exhibit considerable variability in composition and biological activities. In this work, mice weighing 18-20 g (n = 4 for each experimental group) were used. For the edematogenic activity mice were injected s.c. in the right foot pad with 50 microl of solutions containing different amounts of venom, whereas the left foot pad was injected with 50 microl of PBS. Two hours after injection mice were killed by cervical dislocation and both feet were cut off and weighed individually. For the myotoxic activity mice were injected i.m. with 100 microl of solutions containing 40 microg of venom. Blood samples were extracted after 1, 3, 6, 8, 10, 12, 14, 16 and 24 h of venom injection to determinate serum CPK activity and mice were sacrificed at the same time intervals to obtain the inoculated gastrocnemius muscle. They were fixed with Bouin solution and stained with Hematoxylin-Eosin. Results showed that P. olfersii venom exhibits a high edematogenic activity (MED = 0.31 microg) and a moderate myotoxic activity. Myonecrosis reached its highest level after 12 h of venom injection as shown by plasmatic CPK levels (5,401 +/- 330 IU/l) and microscopic assay. It demonstrates the potential toxicity of the venom of P. olfersii, who inhabits the North-East region of Argentina. It also reinforces the original warning concerning the potential danger of bites by colubrids.

Animals↗

Systolic long axis function of the left ventricle. Global and regional information.

OBJECTIVE: To compare global systolic measurements of mitral annular motion by M-mode and tissue velocity time integral, and annular velocity by pulsed and colour Doppler for precision and bias. Secondly, to compare the ability of annular motion to identify regional dysfunction with segmental analysis by strain rate imaging. DESIGN: Nineteen normal subjects and 19 patients with myocardial infarction were studied with echocardiography. RESULTS: There were significant correlations between ejection fraction (EF) and annular motion/velocity by all methods, ranging from 60 to 80%. Measurements had 95% limits of agreement intervals between 7.7 and 15.6 mm for annulus excursion and 8.8 cm/s for annulus velocities with biases between methods of 0.7-1.9 mm and 2.6 cm/s. Annular motion and velocity were reduced in the patients compared with the control group, but were depressed at all points so the infarcted region could not be identified. Only segmental analysis could identify the region of dyssynergy. CONCLUSION: Annular motion and velocity measure global function, but have high variability and measurements are method dependent. Only segmental analysis can identify regional dyssynergy. This is possible with strain rate imaging, but the precision is still too low for clinical use.

Adult↗

Myocardial contrast echocardiography for the assessment of coronary blood flow reserve: validation in humans.

OBJECTIVES: The aim of this study was to validate the use of myocardial contrast echocardiography to determine coronary blood flow reserve in humans. BACKGROUND: Although myocardial contrast echocardiography has been used to accurately quantify coronary flow reserve in animals, validation for its use in humans to measure flow reserve is lacking. METHODS: We analyzed the time-intensity curve from the anteroseptal region of the left ventricular short axis produced after a left main coronary artery injection of sonicated albumin before and after intracoronary administration of papaverine in 16 patients without angiographically significant coronary artery disease. The ratio of half-time of video intensity disappearance from peak intensity, variable of curve width, area under the time-intensity curve and corrected peak contrast intensity after papaverine compared with baseline were correlated with coronary flow reserve measured simultaneously with an intracoronary Doppler probe in the left anterior descending coronary artery. RESULTS: There was a strong inverse correlation with half-time of contrast washout and coronary flow reserve (r = -0.76, p = 0.0007) and a strong positive correlation between the variable of curve width (which is inversely proportional to curve width) and coronary flow reserve (r = 0.71, p = 0.002). There was a weak but significant inverse correlation between area under the time-intensity curve and coronary flow reserve (r = -0.54, p = 0.03) but no correlation between corrected peak contrast intensity and coronary flow reserve (r = -0.36, p = NS). Despite the strong correlation for the ratios for half-time of contrast washout and variable of curve width and actual coronary flow reserve measured with intracoronary Doppler probe, the transit time ratios consistently underestimated coronary flow reserve. CONCLUSIONS: Myocardial contrast echocardiography performed with left main coronary artery injections of sonicated albumin can be utilized to measure coronary flow reserve in humans. Transit time variable ratios (half-time of contrast washout and variable of curve width) derived from the time-intensity curve correlate most strongly with coronary flow reserve.

Adult↗

Interindividual differences of medial temporal lobe activation during encoding in an elderly population studied by fMRI.

Functional MRI (fMRI) is used to study medial temporal lobe (MTL) activation during encoding of new information into memory. In most studies, fMRI data of different subjects are averaged in standard coordinate space. However, interindividual differences in activation can be extensive, reflecting functional heterogeneity. Further, anatomical differences in brain structure cause additional variance and loss of registration accuracy. Such differences in structural and functional MTL characteristics may interfere with the efficiency of averaging data across subjects, and may become more significant with aging and dementia. The current study concerns the analysis of individual differences in MTL activation associated with episodic encoding.Twenty-nine healthy elderly men between 60 and 70 years old performed a simple face encoding task during fMRI scanning. Individual data were analyzed in native space, and compared to the group average in standard space (Talairach and Tournoux).MTL volumes between subjects varied between 6.34 and 11.27 cm(3), and had considerable variation when mapped to standard space. Eighteen of the 29 subjects showed MTL activity and activation patterns varied both in location and size (ranging from 0.11 to 1.78 cm(3)), with the strongest activation in the left posterior part of the MTL. In standard space, no region was significantly activated on a group level at a comparable alpha level. We conclude that while the majority of elderly subjects show MTL activation during episodic encoding of faces, there is considerable structural and functional variability between subjects. Group analysis in standard space may not be appropriate for studies of a complex structure such as the MTL, particularly not in aging and dementia.

Aged↗