Age-matched Normal Control Subjects Research Articles

Decreased Levels of Serum Brain-Derived Neurotrophic Factor in Male Pediatric Patients with Depression

Background: Brain-derived neurotrophic factor (BDNF) plays an important role in the pathophysiology of ma- jor depressive disorder (MDD). Several meta-analyses have shown decreased serum levels of BDNF in adult patients with MDD, but there has been no report on the serum levels of BDNF in pediatric patients with depression. In this study, we investigated whether serum levels of BDNF are altered in pediatric patients with depression. Methods: We measured serum BDNF levels in the following four groups: male pediatric patients with depression (n = 13), female pediatric patients with depression (n = 17), and age-matched normal control subjects (n = 10 for Male, n=12 for Female). Patients were evaluated using the Children's Depression Rating Scale Revised (CDRS-R). Serum levels of BDNF were measured with the sandwich ELISA method. Results: Serum levels (6.97 ± 3.69 ng/mL (mean ± SD)) of BDNF in male pediatric patients with depression were signifi- cantly (p=0.019) lower than those (10.67 ± 3.11 ng/mL) in the male control group. However, there was no difference be- tween the female pediatric patients with depression (9.29 ± 4.61 ng/mL) and the female control group (10.21 ± 4.79 ng/mL). Furthermore, there was no correlation between serum levels of BDNF and CDRS-R scores in the pediatric pa- tients with depression. Interestingly, there was a significant negative correlation (r = -0.683, p=0.010) between the serum BDNF levels and the duration of illness in male, but not female, pediatric patients with depression. Conclusions: This study suggests that low BDNF levels may play a role in the pathophysiology of male pediatric patients with depression.

Detecting cognitive impairment by eye movement analysis using automatic classification algorithms

The Visual Paired Comparison (VPC) task is a recognition memory test that has shown promise for the detection of memory impairments associated with mild cognitive impairment (MCI). Because patients with MCI often progress to Alzheimer's Disease (AD), the VPC may be useful in predicting the onset of AD. VPC uses noninvasive eye tracking to identify how subjects view novel and repeated visual stimuli. Healthy control subjects demonstrate memory for the repeated stimuli by spending more time looking at the novel images, i.e., novelty preference. Here, we report an application of machine learning methods from computer science to improve the accuracy of detecting MCI by modeling eye movement characteristics such as fixations, saccades, and re-fixations during the VPC task. These characteristics are represented as features provided to automatic classification algorithms such as Support Vector Machines (SVMs). Using the SVM classification algorithm, in tandem with modeling the patterns of fixations, saccade orientation, and regression patterns, our algorithm was able to automatically distinguish age-matched normal control subjects from MCI subjects with 87% accuracy, 97% sensitivity and 77% specificity, compared to the best available classification performance of 67% accuracy, 60% sensitivity, and 73% specificity when using only the novelty preference information. These results demonstrate the effectiveness of applying machine-learning techniques to the detection of MCI, and suggest a promising approach for detection of cognitive impairments associated with other disorders.

Antioxidant activity in children with ADHD – a comparison in untreated and treated subjects with normal children

Introduction: Attention deficit hyperactivity disorder (ADHD) is a frequently encountered clinical condition in children. Based on DSM IV-TR criteria it can be sub-classified into three distinct types namely hyperactiveimpulsive, inattentive and combined. Materials and Methods: In the present study, salivary antioxidant activity (AOA) in children with ADHD was compared with age-matched normal control subjects, both as a whole and also with regard to the three subtypes. Additionally, the effect of therapy on the altered AOA levels was investigated following short term (<3 months) and long term (1–3 years) treatments. AOA and catalase activities in the saliva were estimated employing previously reported biochemical procedures. Results: While AOA is decreased in ADHD patients as compared to normal subjects, statistically significant decrease is seen only in the combined and the hyperactive-impulsive subtypes. Restoration of AOA and catalase activities is seen only after sustained therapy and not in the short term. Conclusion: It is concluded that ADHD is associated with decrease in AOA and this should possibly also be addressed for limiting the long term outcomes of this condition.

Contribution of the Pedunculopontine Nucleus on Walking in Stroke Patients

Objectives: We attempted to investigate changes of the pedunculopontine nucleus (PPN) according to walking ability in chronic stroke patients, using diffusion tensor imaging (DTI). Methods: 55 consecutive chronic stroke patients who were not able to walk due to injury of the corticospinal tract (CST) at stroke onset and 22 age-matched normal control subjects were recruited. We measured the values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the PPN and assessed the walking ability of each patient. Results: In patients who were able to walk independently, the FA value of the PPN in the affected hemisphere was increased without change of the ADC value (p < 0.05). Increase of the FA value was positively correlated with the degree of walking ability (p < 0.05). In contrast, the ADC value was increased in the affected hemisphere of patients who could not walk, without change of the FA value (p < 0.05). This increase of the ADC value was negatively correlated with the degree of walking ability (p < 0.05). Conclusion: We found that the neuronal activity of the PPN in the affected hemisphere was increased in stroke patients who were able to walk independently. Therefore, we think that the PPN in the affected hemisphere contributed to walking ability in stroke patients with CST injury.

Bayesian Parameter Estimation for Characterizing the Cyclic Variation of Echocardiographic Backscatter to Assess the Hearts of Asymptomatic Type 2 Diabetes Mellitus Subjects

Previous studies have shown that effective quantification of the cyclic variation of myocardial ultrasonic backscatter over the heart cycle might provide a non-invasive technique for identifying the early onset of cardiac abnormalities. These studies have demonstrated the potential for measurements of the magnitude and time delay of cyclic variation for identifying early onset of disease. The goal of this study was to extend this approach by extracting additional parameters characterizing the cyclic variation in an effort to better assess subtle changes in myocardial properties in asymptomatic subjects with type 2 diabetes. Echocardiographic images were obtained on a total of 43 age-matched normal control subjects and 100 type 2 diabetics. Cyclic variation data were generated by measuring the average level of ultrasonic backscatter over the heart cycle within a region of interest placed in the posterior wall of the left ventricle. Cyclic variation waveforms were modeled as piecewise linear functions, and quantified using a novel Bayesian parameter estimation method. Magnitude, rise time and slew rate parameters were extracted from models of the data. The ability of each of these parameters to distinguish between normal and type 2 diabetic subjects, and between subjects grouped by glycated hemoglobin (HbA1c) was compared. Results suggest a significant improvement in using measurements of the rise time and slew rate parameters of cyclic variation to differentiate ( P < 0.001) the hearts of patients segregated based on widely employed indices of diabetic control compared to differentiation based on the magnitude of cyclic variation.(E-mail: james.g.miller@wustl.edu)

The Effect of Thalamic Hemorrhage on the Fornix

ABSTRACTObjectives: The fornix is indirectly connected to the anterior thalamus via the mamilothalamic tract. There has been no diffusion tensor tractography (DTT) study on the effect of thalamic hemorrhage on the fornix. Using DTT, we attempted to investigate the effect of thalamic hemorrhage on the fornix in patients with thalamic hemorrhage. Subjects and Methods: Twenty-one consecutive patients with thalamic hemorrhage and 21 age-matched normal healthy control subjects were recruited. DTT data were acquired at an average of 21 days after onset. We measured fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the three parts of the fornix (column, body, and crus) respectively. Results: FA values of the affected and unaffected hemispheres in the patient group were lower than those of the control group in all three parts of the fornix (p < .05). By contrast, compared with the control group, the ADC value was found to be increased only in the body (p < .05). Conclusions: According to our results, the FA value decrement with increased or normal ADC value in the patient group seems to indicate neuronal loss in the fornix, which appeared to be ascribed to secondary degeneration following thalamic hemorrhage.

Introduction the paper: Posterior fossa decompression and the cerebellum in Chiari type II malformation: A preliminary MRI study, by Salman M

The present paper focuses on the possible role of posterior fossa decompression performed in early infancy as a potential aid in preventing cerebellar atrophy progression in children with spina bifida aperta and Chiari II malformation. MR findings in a very limited sample group of children (four cases), operated on in the first 2 years of life for their Chiari II malformation, are compared with those obtained in a group of 28 Chiari II malformation not operated on patients and those of 10 age-matched normal control subjects. An increase in mean MR CSF volume within the cerebellar fissures and the fourth ventricle in operated children, if compared with the CSF volume in non-operated patients and the one of normal subjects is the base for indicating a very early surgical correction. In other words, the operated children would have more space available for postnatal cerebellar growth. There are a number of controversial issues concerning this proposal, that have suggested the claim for comments from people experienced in the field; only to cite some of the possible discussion points: 1) The hindbrain embryological development is completed by the second month of embryological life, and hindbrain abnormalities are already completely defined by that time. 2) The rate of children with open spina bifida becoming symptomatic for a Chiari II malformation is relatively low and might not be enough to justify an early preventive surgery, even in a selected proportion of patients. 3) As the same authors state, in spite of a lower rate of Chiari II malformations in patients with open spina bifida operated on in utero, previous studies suggest that cerebellar structures width on postnatal MR is not different, when the Chiari II malformation is present, if the repair of the spinal defect is performed during fetal life or after birth. 4) The surgical risks of a preventive posterior cranial fossa decompression in neonates should not be underestimated and balanced with the only eventual advantage I can foresee of this kind of surgical timing, which is the possible prevention of hindbrain signs in case of shunt malfunction in shunted patients.

Changes in red nucleus after pyramidal tract injury in patients with cerebral infarct

We investigated red nucleus (RN) changes in patients with a cerebral infarct, using diffusion tensor imaging (DTI). Forty-nine consecutive stroke patients with pyramidal tract(PT) injury (mean age, 62.1 years; range, 41 to 75) and 46 age-matched normal healthy control subjects (mean age, 58.9 years; range, 41 to 75) with no history of neurologic disease were recruited. DTI was performed using a 1.5-T system during the early stage, after cerebral infarct (8-l21 days after onset). DTIs were acquired using a sensitivity-encoding head coil at 1.5 T. We measured fractional anisotropies (FAs) and apparent diffusion coefficients (ADCs) of RNs in the upper midbrain, and assessed the motor function of affected extremities. Mean FA of RNs in affected hemispheres was higher than in unaffected hemispheres (P < 0.05), however, no difference was observed between the unaffected control hemispheres (P> 0.05). However, mean ADC values of RNs were no different between control hemispheres and a patient's affected and unaffected hemispheres (P> 0.05). It appears that RN in affected hemispheres show elevated levels of neuronal activity during the early stage in patients with a corona radiata infarct, which suggests that RNs in affected hemispheres are used to compensate for PT injury.

Periodontal Conditions in Elderly Men With and Without Osteoporosis or Osteopenia

The purpose of this case-control study is to investigate the periodontal conditions in elderly men with and without osteoporosis or osteopenia and to determine their possible association with periodontal destruction. A total of 200 community-dwelling Chinese males (age range: 69 to 78 years; mean ± SD age: 71.9 ± 3.3 years) were recruited from the Jockey Club Center for Osteoporosis Care and Control, The Chinese University of Hong Kong, including 67 subjects with osteoporosis, 66 subjects with osteopenia, and 67 age-matched normal control subjects based on bone mineral density at the hip, spine, and whole body measured by dual-energy x-ray densitometry. All subjects were interviewed using questionnaires and received a full-mouth periodontal examination. Subjects with osteoporosis exhibited a significantly higher percentage of sites with clinical attachment loss (AL) > or= 6 mm compared to subjects with osteopenia (P <0.05); subjects with osteoporosis also showed a greater percentage of sites with interproximal gingival recession (GR) > or = 5 mm than did control subjects (P <0.05) after excluding smokers. Subjects with osteoporosis were more likely (odds ratio = 3.3; P <0.05) to exhibit interproximal GR > or = 5 mm than were control subjects. Osteoporosis remained significantly associated with severe clinical AL and interproximal GR after adjusting for age, supragingival plaque, and number of teeth lost. This study suggests that osteoporosis is associated with severe clinical AL and interproximal GR in elderly Chinese men.

A-Kinase Anchoring Proteins

The heart is a sophisticated organ that continuously pumps blood to ensure that oxygen and nutrients reach the brain, other organs, and peripheral tissue. The right side of the heart pumps blood to the lungs, where oxygen is taken up and carbon dioxide is removed. The left side of the heart then pumps blood to the rest of the body, where oxygen and nutrients are delivered to tissues. This cycle is sustained by the repeated contraction of cardiomyocytes, specialized muscle cells that are designed to contract and respond rapidly to physiological stimuli. Normally, contraction of atrial and ventricular myocytes is activated by action potentials that originate in the sinoatrial node in the wall of the right atrium, often referred to as the pacemaker of the heart. Coupling of this electric signal to contraction (EC coupling) in cardiac myocytes is initiated with Ca2+ influx through L-type Ca2+ channels, which activates intracellular Ca2+ release via ryanodine receptors located in the sarcoplasmic reticulum (SR) and thus induces a global increase in [Ca2+]i that triggers contraction.1,2 The rate at which the sinoatrial node myocytes fire action potentials is modulated by 2 opposing nervous systems. The sympathetic nervous system uses the catecholamine hormones noradrenaline and adrenaline to increase the force and rate of atrial and ventricular contraction. In contrast, the parasympathetic nervous system releases the neurotransmitter acetylcholine to reduce action potentials from the sinoatrial node. Together, these neural systems ensure that cardiac output is matched to the physiological needs of the organism, a process that is often termed “stimulus-response coupling.” Although numerous signal-transduction cascades are operational in cardiomyocytes, G-protein–coupled receptor–signaling pathways play a prominent role. Agonists such as noradrenaline, adrenaline, angiotensin II, and endothelin-1 promote the interaction of their respective receptors with a G-protein heterotrimer comprising α-, β-, …

A Comparison of Visual Field Sensitivity to Photoreceptor Thickness in Retinitis Pigmentosa

To explore the relationship between visual field sensitivity and photoreceptor layer thickness in patients with retinitis pigmentosa (RP). Static automated perimetry (central 30-2 threshold program with spot size III; Humphrey Field Analyzer; Carl Zeiss Meditec, Inc., Dublin, CA) and frequency domain optical coherence tomography (Fd-OCT) scans (Spectralis HRA+OCT; Heidelberg Engineering, Vista, CA) were obtained from 10 age-matched normal control subjects and 20 patients with RP who had retained good central vision (better than 20/32). The outer segment (OS+) thickness (the distance between retinal pigment epithelium [RPE])/Bruch's membrane [BM] to the photoreceptor inner-outer segment junction), outer nuclear layer (ONL), and total retinal thickness were measured at locations corresponding to visual field test loci up to 21 degrees eccentricity. The average OS+ thickness in the control eyes was 63.1 +/- 5.2 microm, varying from approximately 69 microm in the foveal center to 56 microm at 21 degrees eccentricity. In patients with RP, OS+ thickness was below normal limits outside the fovea, and thickness decreased with loss in local field sensitivity, reaching an asymptotic value of 21.5 microm at approximately -10 dB. The ONL thickness also decreased with local field sensitivity loss. Although relative OS thickness was linearly related to visual field loss at all locations examined, a slightly better correlation was found between the product of OS and ONL thickness and visual field loss. In patients with RP with good foveal sensitivity, the OS thickness and the product of OS thickness and ONL thickness (assumed to represent the number of photoreceptors) decreases linearly with loss of local field sensitivity. In general, in regions where perimetric sensitivity loss is -10 dB or worse, the OS+ thickness approaches the thickness of the RPE/BM complex.

CORRELATION BETWEEN THICKENING OF THE INNER AND OUTER RETINA AND VISUAL ACUITY IN PATIENTS WITH EPIRETINAL MEMBRANE

The purpose of this study was to examine the relationship between thickening of the inner and outer retinal layers and visual acuity in patients with idiopathic epiretinal membrane. We examined 30 eyes of 30 patients and 25 eyes of 25 healthy volunteers as age-matched normal control subjects. The inner (between the vitreoretinal interface and the outer border of inner plexiform layer), outer, and full retinal thickness at the fovea, parafovea, and perifovea were measured using spectral-domain optical coherence tomography. Thickening ratios of both the inner and outer retina were greater in the fovea than in the other macular regions (P < 0.0001). Inner foveal retinal thickening was significantly greater than outer foveal retinal thickening (P < 0.0001). However, outer retinal thickening in the fovea (r = 0.644, P < 0.001), parafovea (r = 0.616, P < 0.001), and perifovea (r = 0.410, P = 0.025) was significantly correlated with visual acuity; inner retinal thickening was not. Visual acuity tended to be worse, although not significantly so, in eyes with photoreceptor disruption. Epiretinal membrane-induced retinal damage associated with visual acuity seems to be located within the outer retina external to the inner plexiform layer.

Increased levels of 4-hydroxynonenal and acrolein in the brain in preclinical Alzheimer disease

Previous studies demonstrate increased levels of 4-hydroxynonenal (HNE) and acrolein in vulnerable brain regions of subjects with mild cognitive impairment and late-stage Alzheimer disease (LAD). Recently preclinical AD (PCAD) subjects, who demonstrate normal antemortem neuropsychological test scores but abundant AD pathology at autopsy, have become the focus of increased study. Levels of extractable HNE and acrolein were quantified by gas chromatography–mass spectrometry with negative chemical ionization, and protein-bound HNE and acrolein were quantified by dot-blot immunohistochemistry in the hippocampus/parahippocampal gyrus (HPG), superior and middle temporal gyri (SMTG), and cerebellum (CER) of 10 PCAD and 10 age-matched normal control (NC) subjects. Results of the analyses show a significant ( P < 0.05) increase in levels of extractable acrolein in the HPG of PCAD subjects compared to age-matched NC subjects and a significant decrease in extractable acrolein in PCAD CER. Significant increases in protein-bound HNE in HPG and a significant decrease in CER of PCAD subjects compared to NC subjects were observed. No significant alterations were observed in either extractable or protein-bound HNE or acrolein in the SMTG of PCAD subjects. Additionally, no significant differences in levels of protein carbonyls were observed in the HPG, SMTG, or CER of PCAD subjects compared to NC subjects.

Alterations of zinc transporter proteins ZnT-1, ZnT-4 and ZnT-6 in preclinical Alzheimer's disease brain.

Our previous studies demonstrate alterations of zinc (Zn) transporter proteins ZnT-1, ZnT-4 and ZnT-6 in vulnerable brain regions of subjects with mild cognitive impairment (MCI), and early and late stage Alzheimer's disease (AD), suggesting disruptions of Zn homeostasis may play a role in the pathogenesis of AD. A preclinical stage of AD (PCAD) has been described in which subjects show no overt clinical manifestations of AD, but demonstrate significant AD pathology at autopsy. To determine if alterations of ZnT proteins occur in PCAD, we measured ZnT-1, ZnT-4 and ZnT-6 in the hippocampus/parahippocampal gyrus (HPG) and cerebellum (CER) of seven PCAD subjects and seven age-matched normal control (NC) subjects using Western blot analysis and immunohistochemistry. Our results show a significant decrease (P < 0.05) of ZnT-1 in HPG of PCAD subjects, along with an increase of ZnT-4 in PCAD CER and ZnT-6 in PCAD HPG, but a significant decrease in PCAD CER compared to NC subjects. Confocal microscopy of representative sections of HPG shows altered ZnTs are associated with neurons immunopositive for MC-1, a monoclonal antibody that identifies neurons early in formation of neurofibrillary tangles. Overall, our results suggest that alterations in Zn transport proteins may contribute to the pathology observed in PCAD subjects before onset of clinical symptoms.

Smaller insula and inferior frontal volumes in young adults with pervasive developmental disorders

Enlarged head circumference and increased brain weight have been reported in infants with pervasive developmental disorders (PDD), and volumetric studies suggest that children with PDD have abnormally enlarged brain volumes. However, little is known about brain volume abnormalities in young adults with PDD. We explored gray matter (GM) volume in young adults with PDD. T1-weighted volumetric images were acquired with a 3-T magnetic resonance scanner from 32 males with high-functioning PDD (23.8±4.2 years; Full Scale Intelligence Quotient [FSIQ]=101.6±15.6) and 40 age-matched normal male control subjects (22.5±4.3 years; FSIQ=109.7±7.9). Regional GM volumes were compared between the two groups using voxel-based morphometry (VBM) with the Diffeomorphic Anatomical Registration using Exponentiated Lie algebra (DARTEL). Compared with the control group, the high-functioning PDD group showed significantly less GM in the right insula, the right inferior frontal gyrus, and the right inferior parietal lobule. A conservative threshold confirmed considerably smaller volumes in the right insula and inferior frontal gyrus. In these areas, negative correlations were found between Autism Spectrum Quotient scores and GM volume, although no significant correlations were found between each subject's FSIQ and GM volume. No regions showed greater GM volumes in the high-functioning PDD group. The insular cortex, which works as a relay area for multiple neurocognitive systems, may be one of the key regions underlying the complex clinical features of PDD. These smaller GM volumes in high-functioning PDD subjects may reflect the clinical features of PDD itself, rather than FSIQ.

A deformation‐based morphometry study of patients with early‐stage Parkinson’s disease

Previous volumetric magnetic resonance imaging (MRI) studies of Parkinson's disease (PD) utilized primarily voxel-based morphometry (VBM), and investigated mostly patients with moderate- to late-stage disease. We now use deformation-based morphometry (DBM), a method purported to be more sensitive than VBM, to test for atrophy in patients with early-stage PD. T1-weighted MRI images from 24 early-stage PD patients and 26 age-matched normal control subjects were compared using DBM. Two separate studies were conducted, where two minimally-biased nonlinear intensity-average were created; one for all subjects and another for just the PD patients. The DBM technique creates an average population-based MRI-average in an iterative hierarchical fashion. The nonlinear transformations estimated to match each subject to the MRI-average were then analysed. The DBM comparison between patients and controls revealed significant contraction in the left cerebellum, and non-significant trends towards frontal, temporal and cingulate sulcal expansions with frontal and temporal white matter contractions. Within the patient group, the unified PD rating scores were highly correlated with local expansions in or near sulci bordering on frontal and temporal cortex. Our results suggest that DBM could be a sensitive method for detecting morphological changes in early-stage PD.

Platelet Serotonin Transporter Function and Heart Rate Variability in Patients with Panic Disorder

Many studies showed abnormal serotonin transporter (5-HTT) function and heart rate variability (HRV) in panic disorder patients. The present study investigated the relationship between HRV power spectral analysis findings and platelet serotonin uptake in panic disorder patients. Short-term HRV over 5 min and platelet serotonin transporter uptake parameters (Vmax and Km) were measured both in 45 patients with panic disorder and in 30 age-matched normal healthy control subjects. Low frequency power (LF) normalized unit (nu) and LF/high frequency power (HF) were significantly higher, whereas HF and HF nu were lower in the patient group than in the control group. Vmax and Km were all significantly lower (i.e., reflects decreased 5-HTT function) in patients with panic disorder than in normal controls. In the patient group, Km was negatively correlated with LF/HF and LF nu whereas no such correlations between them were found in the control group. By multivariate analysis based on multiple hierarchical linear regression, a low Km independently predicted an increased LF nu even after controlling for age, sex, and body mass index in the patient group. These results suggest that impaired 5-HTT function is closely related to dysregulation of autonomic nervous system in panic disorder.

Diffusion Tensor Imaging in Arginase Deficiency Reveals Damage to Corticospinal Tracts

Individuals with a proximal urea cycle disorder, such as carbamoyl phosphate synthetase deficiency 1 or ornithine transcarbamylase deficiency, may present with encephalopathy resulting from hyperammonemia. The clinical presentation of arginase deficiency is considerably different, characterized by progressive spasticity involving the lower extremities and usually dementia. Diagnosis may be delayed, and patients are often thought to have cerebral palsy. The true etiology of brain injury in arginase deficiency is unknown, but is not thought to be due to hyperammonemia and brain swelling, the mechanism of injury recognized in ornithine transcarbamylase deficiency. Elevated arginine could augment nitric oxide synthesis, leading to oxidative damage. The hypothesis for the present study was that specific brain vulnerability in arginase deficiency would involve microstructural alterations in corticospinal tracts and that this finding, as measured by diffusion tensor imaging, would differ from age-matched control subjects and those with ornithine transcarbamylase deficiency. Diffusion tensor imaging data were compared for a 17-year-old male patient with arginase deficiency, age-matched normal control subjects, and age-matched individuals with ornithine transcarbamylase deficiency. Significant differences were found in suspected areas of interest, specifically in the corticospinal tracts. This finding confirms the hypothesis that the mechanism of injury in arginase deficiency, although still unknown, is unlikely to be similar to that causing ornithine transcarbamylase deficiency.

Sympathetic nervous function and the effect of the catechol-O-methyltransferase Val158Met polymorphism in patients with panic disorder

BackgroundSympathetic nervous function abnormalities have long been suggested to be a possible etiology of panic disorder (PD). Catechol-O-methyltransferase (COMT) affects sympathetic activities, and the COMT Val158Met polymorphism has been suggested to be related to PD. The authors examined the relationship between sympathetic nervous function and the COMT Val158Met polymorphism in PD patients. MethodsFifty-eight patients [Val/Val (51.7%) and Met allele carriers (48.3%)] and 58 age-matched normal control subjects [Val/Val (56.9%) and Met allele carriers (43.1%)] were compared in terms of finger skin temperature, which is known to be a useful marker of sympathetic nervous function. ResultsA significant COMT Val158Met polymorphism×diagnosis interaction was found. Specifically, the met allele was found to be associated with a lower skin temperature in PD patients. ConclusionThese results suggest that the COMT Met allele is related to the higher sympathetic nervous function observed in PD.

Retinal nerve fiber layer thickness in chronic renal failure without diabetes mellitus

To evaluate the retinal nerve fiber layer (RNFL) thickness in patients with chronic renal failure (CRF) without diabetes mellitus by using optical coherence tomography (OCT). Sixty-six eyes of 33 patients with CRF were evaluated. Eighteen patients have been treated with hemodialysis (group 1) and 15 patients have been treated with peritoneal dialysis (group 2). The RNFL thicknesses were assessed before and after the hemodialysis in group 1. None of these patients had diabetes mellitus. Forty eyes of 20 age-matched normal control subjects were assessed in group 3. An RNFL thickness protocol was used to acquire circular scans of 3.4 mm in diameter around the optic nerve. For each eye, RNFL thicknesses were evaluated in 4 quadrants. All of the measurements were automatically calculated by the existing OCT software. All normal subjects and CRF patients underwent comprehensive ophthalmologic examination. The mean and quadrantal RNFL thickness values in patients with CRF were compared with the control group. The mean RNFL thickness values in patients with CRF were statistically significantly lower than the control group. Differences between the RNFL thickness values in group 1 and group 2 and the predialysis and postdialysis measurements were not statistically significant. The RNFL thickness in CRF without DM, which was measured by OCT-3, was found to be significantly decreased. The presence of CRF can be a source of false positive results and lead to overestimation of glaucomatous optic neuropathy.