Age-matched Normal Subjects Research Articles

Motion perimetry identifies nerve fiber bundlelike defects in ocular hypertension.

To determine whether patients with ocular hypertension (OHT) have elevated motion perimetry thresholds. Motion perimetry uses a customized computer graphics program to detect the ability to identify a coherent shift in position of 50% of dots in a defined circular area against a background of fixed dots. Motion size threshold is defined as the smallest circular area in which dot motion is detected. Subjects respond by touching the area of the computer monitor with a light pen where motion stimuli are perceived. Reaction times (milliseconds) to stimuli and localization error (number of pixels from target center) are also obtained for each trial. University hospital ophthalmology clinic. Twenty-seven patients with OHT and 27 age-matched normal subjects. One eye was tested in each subject. Random dot motion stimuli size thresholds and total deviation probability plot data, reaction times, and spatial localization errors. The patients with OHT had more abnormal test points in the total deviation probability plot analysis compared with the controls (P < .001, chi 2). The abnormal test points were concentrated in the superior and inferior nasal regions. Six subjects had nerve fiber bundlelike defects to motion stimuli. Six subjects (5 overlapping with the probability plot analysis) had abnormal glaucoma hemifield test results. The patients with OHT also had significantly greater localization errors. Motion threshold perimetry may be a more sensitive method to detect visual field abnormalities in OHT than conventional automated perimetry.

An accelerated increase of plasma adrenomedullin in acute asthma

A novel vasorelaxant peptide, adrenomedullin (AM), has been isolated from the acid extract of human pheochromocytoma. We have recently shown that AM inhibits histamine- and acetylcholine-induced bronchoconstriction in anesthetized guinea pigs in vivo, and this bronchodilatory effect is long-lasting. Here, we measured plasma AM concentrations in nine patients with an acute attack of bronchial asthma. The results were compared with values in 30 age-matched normal control subjects and seven age-matched stable asthmatic patients. The mean AM concentrations of patients with an acute asthma attack (98 ± 22 pg/mL) were clearly higher than those of normal control subjects (18 ± 2 pg/mL) and stable asthmatic patients (21 ± 3 pg/mL). Reverse-phase high-performance liquid chromatography (HPLC) showed that the major component of plasma immunoreactive AM in patients with an asthma attack and in normal subjects equally corresponded to authentic human AM(1–52). Our results suggest that plasma AM is markedly increased in many of the patients during an acute attack of bronchial asthma, but it is not observed in stable asthmatic patients. Although this report is preliminary, the observed increase of circulating AM during an acute asthma attack may represent a compensatory mechanism against the bronchoconstriction, probably through its bronchodilatory action.

The processing of morphology and syntax in aphasia: A test of the fast decay and slow activation hypotheses

Abstract Two tasks were designed to test the hypothesis that the syntactic processing deficit of non-fluent agrammatic aphasic patients may be due to either the fast decay or slow activation of syntactic information. Eight non-fluent aphasics, 11 fluent aphasics, and 15 age-matched normal control subjects participated in two auditory lexical decision tasks as well as a grammaticality judgement task. In three types of sentence structures the sentence-final word created either a grammatical sentence or a violation of a particular syntactic rule or constraint. To examine possible deficits in computational speed, the interval between the sentence frame and the sentence-final target word was set at either 100 ms (short ISI) or 1000 ms (long ISI) in the lexical decision tasks. Increased reaction time to targets in ungrammatical sentences is indicative of sensitivity to syntactic violations. With fast decay of syntactic information, sensitivity would be predicted at short but not long ISIs. With slow activation,...

Doppler echocardiographic index for assessment of global right ventricular function

Echocardiographic assessment of right ventricular function remains difficult and challenging. However, there is considerable clinical need for a simple, reproducible, and reliable parameter of right ventricular function in patients with right-sided heart disease. The purpose of this study was to assess the clinical value of a Doppler-derived index, combining systolic and diastolic intervals of the right cycle, in assessing global right ventricular function in patients with primary pulmonary hypertension. The study population comprised 26 consecutive patients with primary pulmonary hypertension and 37 age-matched normal subjects. The sum of right ventricular isovolumetric contraction time and isovolumetric relaxation time was obtained by subtracting right ventricular ejection time from the interval between cessation and onset of the tricuspid inflow velocities with pulsed-wave Doppler echocardiography. An index of combined right ventricular systolic and diastolic function was obtained by dividing the sum of both isovolumetric intervals by ejection time. The index was compared with available parameters of systolic or diastolic function, clinical symptoms, and survival. Right ventricular isovolumetric contraction time and isovolumetric relaxation time were prolonged significantly in patients with primary pulmonary hypertension (85 ± 41 msec and 135 ± 43 msec) compared with normal subjects (38 ± 7 msec and 49 ± 9 msec, respectively; p < 0.001). Ejection time was shortened significantly in patients with pulmonary hypertension (241 ± 43 msec versus normal [322 ± 21 msec]; p < 0.001). However, the index was the single most powerful variable to discriminate patients with primary pulmonary hypertension from normal subjects (0.93 ± 0.34 versus 0.28 ± 0.04; p < 0.001) and was the strongest predictor of clinical status and survival. The index was not significantly affected by heart rate, right ventricular pressure, right ventricular dilation, or tricuspid regurgitation. It is well known that right ventricular systolic and diastolic dysfunction coexist in patients with primary pulmonary hypertension. This article reports the use of an easily obtainable Doppler-derived index that combines elements of systolic and diastolic function. This index appears to be a useful noninvasive means that correlates with symptoms and survival in patients with primary pulmonary hypertension.

The temporal frequency response function of pattern ERG and VEP: changes in optic neuritis

Steady-state pattern electroretinograms (PERGs) and visual evoked potentials (VEPs) in response to sinusoidal gratings (2 c/deg), sinusoidally counterphased at closely spaced temporal frequencies (TFs) between 4 and 28 Hz, were recorded from 11 patients with unilateral optic neuritis (ON; 11 affected eyes and 10 healthy fellow eyes) and 7 age-matched normal subjects (7 eyes). Amplitude and phase of responses' second harmonics were measured. Responses' apparent latencies were estimated from the rate at which phase lagged with TF. When compared to control values, mean PERG and VEP amplitudes of ON eyes were reduced (by about 0.4 log units) at both low (5–10 Hz) and high (16–20 Hz) TFs. Mean PERG amplitudes of fellow eyes were selectively reduced at low TFs (by about 0.3 log units). Mean PERG apparent latencies of both ON and fellow eyes were delayed (by 15 and 9 ms, respectively). Mean VEP apparent latency of ON eyes was delayed at both low and high TFs (by 24 and 30 ms, respectively), while that of fellow eyes was selectively delayed at high TFs (by 28 ms). The results in ON eyes indicate non-selective abnormalities of PERG and VEP generators responding at both low and high TFs. VEP TF losses may be in part accounted for by corresponding PERG losses. In the fellow eyes of patients, more selective PERG and VEP TF abnormalities may suggest differential impairment of retinal and postretinal subsystems responding better to low and high TFs (i.e. parvo-and magnocellular streams).

Swallowing disorders in head and neck cancer patients treated with radiotherapy and adjuvant chemotherapy.

The nature of swallowing problems was examined in nine patients treated primarily with external-beam radiation and adjuvant chemotherapy for newly diagnosed tumors of the head and neck. All subjects underwent videofluorographic examination of their swallowing. Three analyses were completed, including the following: observations of motility disorders, residue, and aspiration; temporal analyses; and biomechanical analyses. Oropharyngeal swallow efficiency was calculated for the first swallow of each bolus. Swallow motility disorders were observed in both the oral and pharyngeal stages. Seven of the nine patients demonstrated reduced posterior tongue base movement toward the posterior pharyngeal wall and reduced laryngeal elevation during the swallow. Oropharyngeal swallow efficiency measures were significantly lower in the nine irradiated patients than in age-matched normal subjects. Between patients and normal subjects, significant differences were found in the measures of timing and distance of pharyngeal structural movements during the swallow, as well as in the measures of coordination during the swallow. Although treatment of head and neck cancer with external-beam radiation is designed to provide cancer cure and preserve organ functioning, oral and pharyngeal motility for swallow can become compromised if external-beam radiation treatment is provided to either the larynx or tongue base regions.

The temporal frequency response function of pattern ERG and VEP: changes in optic neuritis

Steady-state pattern electroretinograms (PERGs) and visual evoked potentials (VEPs) in response to sinusoidal gratings (2 c/deg), sinusoidally counterphased at closely spaced temporal frequencies (TFs) between 4 and 28 Hz, were recorded from 11 patients with unilateral optic neuritis (ON; 11 affected eyes and 10 healthy fellow eyes) and 7 age-matched normal subjects (7 eyes). Amplitude and phase of responses' second harmonics were measured. Responses' apparent latencies were estimated from the rate at which phase lagged with TF. When compared to control values, mean PERG and VEP amplitudes of ON eyes were reduced (by about 0.4 log units) at both low (5–10 Hz) and high (16–20 Hz) TFs. Mean PERG amplitudes of fellow eyes were selectively reduced at low TFs (by about 0.3 log units). Mean PERG apparent latencies of both ON and fellow eyes were delayed (by 15 and 9 ms, respectively). Mean VEP apparent latency of ON eyes was delayed at both low and high TFs (by 24 and 30 ms, respectively), while that of fellow eyes was selectively delayed at high TFs (by 28 ms). The results in ON eyes indicate non-selective abnormalities of PERG and VEP generators responding at both low and high TFs. VEP TF losses may be in part accounted for by corresponding PERG losses. In the fellow eyes of patients, more selective PERG and VEP TF abnormalities may suggest differential impairment of retinal and postretinal subsystems responding better to low and high TFs (i.e. parvo-and magnocellular streams).

Doppler index combining systolic and diastolic myocardial performance: Clinical value in cardiac amyloidisis

Objectives. This study was designed to determine the clinical value of a Doppler-derived index of combined systolic and diastolic myocardial performance in the assessment of cardiac amyloidosis.Background. Cardiac amyloidosis is an infiltrative disease with diastolic and systolic dysfunction. Therefore, the index of myocardial performance combining systolic and diastolic time intervals could be a useful predictor of clinical outcome in cardiac amyloidosis.Methods. The study included 45 patients with biopsy-proved amyloidosis and 45 age-matched normal subjects. All patients had typical echocardiographic features of amyloid cardiac involvement.t A Doppler-derived index, defined as the sum of isovolumetric contraction time and isovolumetric relaxation time divided by ejection time, was measured from left ventricular outflow and mitral inflow Doppler velovity profiles recorded during routine echocardiography. The index as well as conventional systolic or diastolic echocardiographic/Doppler variables were related to subsequent outcome.Results. The isovolumetric contraction and relaxation times were prolonged and ejection time was shortened (p < 0.001) in patients with amyloidosis compared with that in normal subjects, resulting in a marked increase of the index from normal values (p < 0.001). In the amyloid group the index was highest in patients with a low stroke index or with both shortened mitral deceleration time and lower ejection fraction. By univariate analysis, New York Heart Association functional class, the index, ejection fraction and mitral deceleration time were significant predictors of outcome. However, by multivariate stepwise regression analysis, functional class and the index were the only independent predictors of survival.Conclusions. The Doppler-derived index of combined systolic and diastolic myocardial performance correlates with global cardiac dysfunction and is a useful predictor of clinical outcome in patients with cardiac amyloidosis.

Improvement of Atherosclerosis and Stiffness of the Thoracic Descending Aorta With Cholesterol-Lowering Therapies in Familial Hypercholesterolemia

The thoracic aorta is frequently involved in atherosclerotic lesions associated with familial hypercholesterolemia (FH). Transesophageal echocardiography (TEE) allows quantitative evaluation of the wall properties of the thoracic aorta. Using TEE, we tested whether atherosclerosis of the thoracic aorta in FH could be improved by cholesterol-lowering therapies. The subjects investigated were 22 FH patients and 22 age-matched normal subjects. The descending aorta (DA) was divided into four longitudinal portions of equal length. Atheromatous lesions of each portion of the DA were scored by character and extension of lesions by biplane two-dimensional TEE. The scores of atheromatous lesions from all four portions of the DA were added together to give the total atheromatous score (TAS). We also measured instantaneous dimensional changes of the DA in a cardiac cycle by M-mode TEE and blood pressure by a cuff method and calculated the stiffness parameter beta (In[SBP/DBP]/[Dmax-Dmin]/Dmin), where SBP is the systolic arterial blood pressure, DBP is the diastolic arterial blood pressure, Dmax is the maximum aortic dimension during the ejection period, and Dmin is the minimum aortic dimension during the preejection period. TAS was higher in FH (3.70 +/- 1.32) than normal (0.62 +/- 0.54, P < .0001) subjects. Beta in FH (10.35 +/- 4.87) was greater than in normal (5.10 +/- 1.25, P < .0001) subjects, but there were no significant differences of DA dimensions between the groups. In both normal subjects and FH patients, beta correlated with age (r = .52, P < .02 and r = .59, P < .005, respectively). In FH patients, beta and TAS correlated well with pretreatment total cholesterol levels (r = .43, P < .05 and r = .60, P < .005, respectively). In 12 of 22 FH patients, strict cholesterol-lowering therapies with diet and cholesterol-lowering drugs (pravastatin and probucol) were undertaken for 13 months. Cholesterol levels were significantly decreased from 333 +/- 45 to 219 +/- 39 mg/dL (P < .0001); this was associated with significant decreases in beta and TAS (from 9.88 +/- 5.03 to 7.88 +/- 3.92, P < .005, and from 3.61 +/- 1.50 to 2.94 +/- 1.22, P < .0005, respectively). In FH patients, the incidence and severity of morphological and physiological atherosclerosis of the DA were significantly higher than in age-matched normal subjects. A significant regression of atherosclerosis was achieved by strict cholesterol-lowering therapies in relatively young FH patients.

Motor skill learning in Parkinson's disease

The motor performance of patients with Parkinson's disease is degraded, but it is unclear whether their motor learning (adaptation learning and skill learning) ability is impaired. To assess the ability of these patients to learn motor tasks, we studied nine Parkinson's disease patients and eight age-matched normal (control) subjects who repetitively traced, as rapidly and accurately as possible, irregular geometric patterns with normal and mirror-reversed vision. The outcome was measured by statistical analysis and graphic plotting of values for actual and standardized performance variables and correlation of data from initial and final performance variables with indicators of disease severity. The results showed that, with normal vision, total movement time was reduced in both patients and normal subjects, but movement errors increased with repetition, apparently reflecting a speed-accuracy trade-off and adaptation learning. With mirror-reversed vision, total movement time and movement errors were reduced equally with repetition in both groups. These concomitant improvements in time and accuracy violate the rule of speed-accuracy trade-off and suggest that this behavior reflects true motor skill learning. We conclude that patients with Parkinson's disease do not differ from normal subjects in the processes of motor adaptation and motor skill learning.

Motor skill learning in Parkinson's disease

The motor performance of patients with Parkinson's disease is degraded, but it is unclear whether their motor learning (adaptation learning and skill learning) ability is impaired. To assess the ability of these patients to learn motor tasks, we studied nine Parkinson's disease patients and eight age-matched normal (control) subjects who repetitively traced, as rapidly and accurately as possible, irregular geometric patterns with normal and mirror-reversed vision. The outcome was measured by statistical analysis and graphic plotting of values for actual and standardized performance variables and correlation of data from initial and final performance variables with indicators of disease severity. The results showed that, with normal vision, total movement time was reduced in both patients and normal subjects, but movement errors increased with repetition, apparently reflecting a speed-accuracy trade-off and adaptation learning. With mirror-reversed vision, total movement time and movement errors were reduced equally with repetition in both groups. These concomitant improvements in time and accuracy violate the rule of speed-accuracy trade-off and suggest that this behavior reflects true motor skill learning. We conclude that patients with Parkinson's disease do not differ from normal subjects in the processes of motor adaptation and motor skill learning.

Neutrophil CD11b Expression in Patients with Venous Disease

Objective: To determine whether neutrophil CD11b, a marker of neutrophil adhesion, differs in patients with varying degrees of severity of venous disease, and to compare the values obtained with those of age-matched normal control subjects. Design: Prospective study, measuring white cell count and neutrophil CD11b expression in whole blood using a fluorescent-labelled monoclonal antibody in a flow cytometer. Setting: The Middlesex Hospital Vascular Laboratory, a referral centre for the investigation of venous disease. Patients: Ten patients with uncomplicated varicose veins, 10 patients with skin changes of lipodermatosclerosis (LDS), and 20 age-matched control subjects with no history or clinical finding of venous disease. Results: Higher levels of CD11b were found in patients with uncomplicated varicose veins compared with their controls (median 4.6 cf. 1.43 for normal controls, P = 0.005, Mann-Whitney U-test, difference between medians 2.7, 95% confidence interval 1 to 4.6), and lower levels in patients with LDS (median 1.22 cf. 1.53 for normal controls, p = 0.028, Mann-Whitney U-test, difference between medians 0.45, 95% confidence interval 0.02 to 1.3). There was no difference in the white cell or neutrophil count between the patient and control groups. Conclusions: This study demonstrates increased neutrophil surface CD11b expression in patients with uncomplicated varicose veins, but decreased levels in patients with LDS. This might be due to up-regulation of CD11b in some neutrophils with subsequent adhesion, so that only those with low expression remained in the peripheral circulation. Alternatively, this might represent either down-regulation or chronic exhaustion of neutrophil CD11b in these patients.

Neural Networks to Identify Glaucoma With Structural and Functional Measurements

Neural networks can recognize patterns and classify complex variables. We assessed the ability of neural networks to discriminate between normal and glaucomatous eyes by using structural and functional measurements. Several neural network algorithms were tested with a database of 185 eyes of patients with early glaucomatous visual field loss (average mean defect, 4.5 dB) and 54 eyes of age-matched normal control subjects. The information used included automated visual field indices (mean defect, corrected loss variance, and short-term fluctuation) and structural data (cup/disk ratio, rim area, cup volume, and nerve fiber layer height) from computerized image analysis. A back propagation network with two intermediate layers assigned an estimated probability of being glaucomatous to each eye and correctly identified 88% of all eyes with 90% sensitivity and 84% specificity. The same neural network trained with only structural data correctly identified 80% of the eyes with 87% sensitivity and 56% specificity, and when trained with functional data only, it correctly identified 84% of the eyes with 84% sensitivity and 86% specificity. Analysis of several optic nerve and visual field variables by neural networks can help identify early glaucomatous damage and assign an estimated probability that early damage is present in individual patients.

Cortical glucose metabolism in psychiatric wandering patients with vascular dementia

The cerebral metabolic rate for glucose (CMR glc) in 18 patients with vascular dementia (VD) and 15 age-matched normal subjects was measured with positron emission tomography (PET) and the 18F-flurodeoxyglucose technique. Nine of the 18 VD patients manifested abnormal wandering behavior with some psychiatric symptoms: they showed relatively spared CMR glc, which was higher than that of nonwandering patients, especially in the bilateral frontal lobes, left parietal lobe, left temporo-parieto-occipital region, left occipital lobe, and cerebellum. The results suggest that psychiatric wandering behavior of patients with VD could be correlated with partial sparing of CMR glc in the regions listed below.

Tidal breathing analysis as a measure of airway obstruction in children three years of age and older.

This study was designed to evaluate the value and applicability of tidal breathing pattern analysis to assess airflow obstruction in young children. The time needed to reach maximal tidal expiratory flow (TME) divided by total expiratory time (TE) was measured in 228 healthy children 3 to 11 yr of age, 64 patients with asthma, and 12 children with cystic fibrosis. In 70 patients both TME/TE and forced maximal expiratory flow volume (MEFV) parameters were measured. The mean TME/TE in healthy subjects was 43.0 +/- 7.6%. The within-subject reproducibility was high (repeatability index, 5.3%). In the asthmatic patients the mean TME/TE was significantly lower (30.0 +/- 8.2%, p < 0.001), and it increased to 36.5 +/- 7.9% after bronchodilation (n = 44, p < 0.001). The TME/TE level of the subgroup of patients with asthma and FEV1/FVC > or = 0.80 was lower when compared with age-matched normal subjects (30.9 +/- 8.5, p < 0.0001), but it was in a higher range when compared with asthmatics with FEV1/FVC < 0.80 (25.9 +/- 7.9, p < 0.001). In the cystic fibrosis group the mean TME/TE was 27.4 +/- 10.7% without a significant change after bronchodilation. TME/TE correlated significantly with MEFV parameters. Tidal breathing analysis proved easy to perform in children older than 3 yr of age. The TME/TE ratio may be a reliable and simple indicator for airway obstruction.

Increased circulating adrenomedullin, a novel vasodilatory peptide, in sepsis.

Human adrenomedullin (hAM), a potent vasodilatory peptide originally identified in pheochromocytoma, has been shown to be present in various human tissues and circulate in human plasma. We measured plasma concentrations of immunoreactive hAM in patients with sepsis who had been admitted to intensive care unit (ICU). Plasma hAM concentrations in 12 septic patients upon entering the ICU were extremely elevated (107 +/- 139 fmol/ml: mean +/- SD) compared to those of 16 age-matched normal subjects (7.9 +/- 3 fmol/mL). Among 10 patients with normal renal function, plasma hAM levels either decreased or increased during the hospital course; the former group survived and the latter group succumbed. Two patients with acute renal failure had markedly elevated plasma hAM levels during the early course, which declined rapidly during the recovery course. High performance liquid chromatography of plasma extracts from one patient with acute renal failure revealed a single major component of immunoreactive hAM coeluting with authentic hAM (1-52) during acute and recovery phase. Plasma hAM concentration showed positive correlations with heart rate, right atrial pressure, and serum creatinine concentration, but not with other hemodynamic variables. These data suggest that a marked increase in circulating hAM in sepsis may be caused by its decreased clearance and/or its enhanced synthesis by multiple organ dysfunction, and that increased endogenous hAM may be involved in the mechanism of cardiovascular abnormalities associated with sepsis.

Pathophysiology of chronic left ventricular dysfunction. New insights from the measurement of absolute myocardial blood flow and glucose utilization.

Chronically dysfunctional myocardium may improve after coronary revascularization. This condition was thought to be due to a chronically reduced myocardial blood flow (MBF). Recently, however, it has been shown that in patients without previous infarction but with chronic left ventricular dysfunction, baseline MBF was normal. To study the pathophysiology of chronic left ventricular dysfunction in patients with previous infarction, regional MBF (milliliter per minute per gram of water-perfusable tissue) and glucose utilization (MRG; micromoles per minute per gram) during hyperinsulinemic euglycemic clamp were measured with positron emission tomography in 30 patients before bypass. At baseline, 133 myocardial segments were normal, and 107 were dysfunctional. After revascularization, 59 of 107 segments improved, while 48 of 107 were unchanged. MBF was 0.92 +/- 0.25 mL.min-1.g-1 in normal segments, 0.87 +/- 0.31 mL.min-1.g-1 in improved segments (P = NS versus normal), and 0.82 +/- 0.40 mL.min-1.g-1 in unchanged segments (P < .05 versus normal). In 90% of the dysfunctional segments, MBF was > 0.42 mL.min-1.g-1, a cutoff value corresponding to the mean MBF minus 2 SD in normal segments. The MRG was 0.71 +/- 0.14 mumol.min-1.g-1 in 9 age-matched normal subjects, 0.45 +/- 0.19 mumol.min-1.g-1 (P < .01) in normal segments, 0.44 +/- 0.14 mumol.min-1.g-1 in improved segments (P = NS versus normal), and 0.34 +/- 0.17 mumol.min-1.g-1 in unchanged segments (P < .01 versus normal and improved). The results suggest that resting MBF measured with 15O-labeled water in chronically dysfunctional segments is not reduced and that the myocardium of these patients is less sensitive to insulin than that of normal subjects.

Serum total and specific IgE levels in children infected with human immunodeficiency virus

BACKGROUND: Human immunodeficiency virus (HIV) infection is associated with polyclonal B-cell activation, and elevated IgE levels are found in infected adults. Chronic nasal symptoms, sinusitis, and otitis media are particularly common in children infected with HIV. The possible allergic cause of nasal symptoms in children infected with HIV has not been explored. OBJECTIVE: The study was designed to evaluate the relationship between HIV infection and IgE levels in a group of children infected with HIV. METHODS: Total serum IgE was measured by enzyme immunoassay and compared with values for age-matched normal subjects. Specific IgE was determined by RAST test to Dermatophagoides pteronyssinus, American cockroach, Bahia grass, short ragweed, cat, and oak. Lymphocyte subpopulations were determined by standard flow cytometry. RESULTS: Fifty-seven total IgE and 342 specific IgE levels were determined from 29 infected children (19 girls and 10 boys; ages, 7 to 150 months; mean age, 49 months). Initial IgE levels of 29 subjects ranged from 1.4 to 787.6 IU/ml (mean = 123.4 ± 34.4 IU/ml). Nine of 29 (31%) subjects had initial IgE levels greater than two standard deviations higher than age-matched normal subjects. No patients had detectable specific IgE to any of the six aeroallergens. There was no correlation, as determined by linear regression analysis, between IgE levels and absolute CD4 number or CD4:CD8. CONCLUSION: Elevated total but not specific IgE is common in children infected with HIV and does not correlate with absolute CD4 lymphocyte count, suggesting that the elevated IgE level reflects a somewhat independent polyclonal activation of B lymphocytes. (J A LLERGY C LIN I MMUNOL 1996;97:692-7.)

Physical Training Improves Endothelial Function in Patients With Chronic Heart Failure

Chronic heart failure is associated with endothelial dysfunction including impaired endothelium-mediated, flow-dependent dilation (FDD). Since endothelial function is thought to play an important role in coordinating tissue perfusion and modulating arterial compliance, interventions to improve endothelial dysfunction are imperative. To assess the potential of physical training to restore FDD, 12 patients with chronic heart failure were studied and compared with FDD of 7 age-matched normal subjects. With a recently developed high-resolution ultrasound system, diameters of radial artery were measured at rest, during reactive hyperemia (with increased flow causing endothelium-mediated dilation), and during sodium nitroprusside, causing endothelium-independent dilation. Determination of FDD was repeated after intra-arterial infusion of NG-monomethyl-L-arginine (L-NMMA, 7 mumol/min) to inhibit endothelial synthesis and release of nitric oxide. The protocol was performed at baseline, after 4 weeks of daily handgrip training, and 6 weeks after cessation of the training program. FDD was impaired in heart failure patients compared with normal subjects. L-NMMA attenuated FDD, indicating that the endothelial release of nitric oxide is involved in FDD. Physical training restored FDD in patients with heart failure. In particular, the portion of FDD inhibited by L-NMMA (representing FDD mediated by nitric oxide) was significantly higher after physical training (8-minute occlusion: 8.0 +/- 1% versus 5.4 +/- 0.9%; P < .05; normal subjects: 9.2 +/- 1%). These results indicate that physical training restores FDD in patients with chronic heart failure, possibly by enhanced endothelial release of nitric oxide.

Proton magnetic resonance spectroscopic imaging in patients with cerebellar degeneration.

Using proton magnetic resonance spectroscopic imaging, we studied the cerebellum of 9 patients with cerebellar degeneration and of 9 age-matched normal control subjects. This technique permits the simultaneous measurement of N-acetylaspartate, choline-containing compounds, creatine/phosphocreatine, and lactate signal intensities from four 15-mm slices divided into 0.84-ml single-volume elements. Because patients with cerebellar degeneration often show substantial atrophy on magnetic resonance imaging (MRI), we specifically chose to analyze the spectroscopic signals only from tissue that did not have an atrophic appearance on the MRI. The spectroscopic findings showed a significant reduction of N-acetylaspartate in all parts of the cerebellum, a significant correlation with MRI scores of cerebellar atrophy, and a significant correlation with clinical rating scores of cerebellar disturbance. Our method of analysis suggests the presence of a neurodegenerative process in cerebellar areas that do not appear to be atrophic on the MRI. Some limitations of proton magnetic resonance spectroscopic imaging in the present study were related to the partial field inhomogeneity characteristics of the posterior fossa, the anatomical location of the cerebellum, and the particularly severe cerebellar atrophy in some of the patients.