Contact heat evoked potentials in normal subjects

Laser-evoked potentials are widely used to investigate nociceptive pathways. The newly developed contact heat stimulator for evoking brain response has the advantages of obtaining reliable scalp potentials and absence of cutaneous lesions. This study aimed to identify the most appropriate stimulation site with consistent cortical responses, and to correlate several parameters of the contact heat evoked potentials (CHEPs) with age, gender, and body height in normal subjects. CHEPs were recorded at Cz with a contact heat stimulator (Medoc, Israel) in 35 normal controls. The subjects were asked to keep eyes open and remain alert. The baseline temperature was 32 degrees C, and stimulation peak heat intensity of 51 degrees C was applied to five body sites: bilateral forearm, right dorsum hand, right peroneal area, and right dorsum foot. Reproducible CHEPs were recorded more frequently when stimulated at volar forearm (62.5%) than at the lower limbs (around 40%). The first negative peak latency (N1) was 370.1 +/- 20.3 ms, first positive peak latency (P1) was 502.4 +/- 33.0 ms, and peak to peak amplitude was 10.2 +/- 4.9 microV with stimulation of the forearm. Perceived pain intensity was not correlated with the presence or amplitude of CHEPs. No gender or inter-side differences were observed for N1 latency and N1-P1 amplitude. Also, no correlation was noted between N1 and age or body height. These results support future clinical access of CHEPs as a diagnostic tool.     

The Effect of Cognitive Behavior Therapy-Based Psychotherapy Applied in a Forest Environment on Physiological Changes and Remission of Major Depressive Disorder

Objective

Psychotherapeutic intervention combined with pharmacotherapy is helpful for achieving remission of depressive disorder. We developed and tested the effect of cognitive behavior therapy (CBT)-based psychotherapy applied in a forest environment on major depressive disorder.

Methods

We performed 4 sessions during 4 weeks (3 hours/session) in patients with major depressive disorder during pharmacotherapy. For the forest group, sessions were performed in the forest; for the hospital group, sessions were performed in the hospital. The control group was treated with the usual outpatient management.

Results

A total of 63 patients completed the study: 23 in the forest group, 19 in the hospital group, and 21 in the control group. Hamilton Rating Scales for Depression (HRSD) scores of the forest group were significantly decreased after 4 sessions compared with controls. Montgomery-Asberg Depression Rating Scales (MADRS) scores of the forest group were significantly decreased compared with both the hospital group and the controls. The remission rate (7 and below in HRSD) of the forest group was 61% (14/23), significantly higher than both the hospital group (21%, 4/19) and the controls (5%, 1/21). In heart rate variability (HRV) analysis, some measurements representing HRV and parasympathetic nerve tone were increased in the forest group after 4 sessions. The salivary cortisol levels of the forest group were significantly decreased.

Conclusion

CBT-based psychotherapy applied in the forest environment was helpful in the achievement of depression remission, and its effect was superior to that of psychotherapy performed in the hospital and the usual outpatient management. A good environment such as a forest helps improve the effect of psychotherapeutic intervention because it includes various natural instruments and facilitators in the treatment of depression.     

The positive and negative affect schedule: psychometric properties of the korean version

Objective

The Positive and Negative Affect Schedule (PANAS) was developed as a measure of positive affect (PA) and negative affect (NA). The aim here is to examine the factor structure and concurrent validity of the Korean version of the Positive and Negative Affect Schedule (K-PANAS) in a clinical sample in Korea.

Methods

K-PANAS was administered to a clinical sample in Korea. Internal consistency, test-retest reliability, and confirmatory factor analysis (CFA) were undertaken to examine the factorial structure and reliability of the K-PANAS.

Results

The reliability of K-PANAS is satisfactory. CFA showed that several of the models commonly used in Western populations provided an insufficient fit. The modified model provided a more adequate fit to the data.

Conclusion

The authors demonstrate that the K-PANAS has adequate psychometric properties, and that findings obtained in the West using PANAS were partially replicated.     

Deep brain stimulation of the nucleus accumbens core and shell: opposite effects on impulsive action

The nucleus accumbens is gaining interest as a target for deep brain stimulation in refractory neuropsychiatric disorders with impulsivity as core symptom. The nucleus accumbens is composed of two subterritories, core and shell, which have different anatomical connections. Here, we tested the hypothesis that stimulation of the nucleus accumbens core and shell would have different effects on impulsivity. Rats received bilateral stimulation at the level of the nucleus accumbens core or shell during a reaction time task. Stimulation of the nucleus accumbens core significantly decreased impulsivity, while stimulation of the shell increased it. Our results support the hypothesis that the nucleus accumbens is a potential target to treat neuropsychiatric disorders related to impulsivity by deep brain stimulation. However, different behavioral effects resulting from stimulation of the subterritories should be taken into account.     

Structural and diffusion tensor imaging of the fornix in childhood- and adolescent-onset schizophrenia

ObjectiveThere is emerging evidence that aberrations in the integrity of cerebral white matter tracts, especially those connected to limbic structures, play a role in the pathophysiology of schizophrenia. The fornix is the primary efferent neural pathway of the hippocampus and has been shown to be abnormal in adults with schizophrenia.MethodHigh-resolution structural magnetic resonance imaging and diffusion tensor images were obtained on 15 patients with childhood- and adolescent-onset schizophrenia and 15 age- and sex-matched controls. Measures of cross-sectional area and water diffusion properties were obtained on regions of interest of the fornix performed by a trained radiologist.ResultsThe volume of the fornix was significantly smaller (10.9%) in children and adolescents with schizophrenia compared to controls (Cohen d = 0.87, p = .025). There were no significant differences between the fractional anisotropy or mean diffusivity between the groups.ConclusionsThese findings suggest that the early stages of schizophrenia are associated with a decrease in fornix volume without microstructural white matter changes. The volume differences may reflect an early insult to neighboring brain regions (i.e., hippocampus), that could decrease the number of efferent fibers without necessarily disrupting fiber integrity. J. Am. Acad. Child Adolesc. Psychiatry, 2008; 47(7):826–832.     

Test-retest and between-site reliability in a multicenter fMRI study

In the present report, estimates of test-retest and between-site reliability of fMRI assessments were produced in the context of a multicenter fMRI reliability study (FBIRN Phase 1, www.nbirn.net). Five subjects were scanned on 10 MRI scanners on two occasions. The fMRI task was a simple block design sensorimotor task. The impulse response functions to the stimulation block were derived using an FIR-deconvolution analysis with FMRISTAT. Six functionally-derived ROIs covering the visual, auditory and motor cortices, created from a prior analysis, were used. Two dependent variables were compared: percent signal change and contrast-to-noise-ratio. Reliability was assessed with intraclass correlation coefficients derived from a variance components analysis. Test-retest reliability was high, but initially, between-site reliability was low, indicating a strong contribution from site and site-by-subject variance. However, a number of factors that can markedly improve between-site reliability were uncovered, including increasing the size of the ROIs, adjusting for smoothness differences, and inclusion of additional runs. By employing multiple steps, between-site reliability for 3T scanners was increased by 123%. Dropping one site at a time and assessing reliability can be a useful method of assessing the sensitivity of the results to particular sites. These findings should provide guidance toothers on the best practices for future multicenter studies.     

Elucidating the molecular physiopathology of acute respiratory distress syndrome in severe acute respiratory syndrome patients

Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury. It is a response to various diseases of variable etiology, including SARS-CoV infection. To date, a comprehensive study of the genomic physiopathology of ARDS (and SARS) is lacking, primarily due to the difficulty of finding suitable materials to study the disease process at a tissue level (instead of blood, sputa or swaps). Hereby we attempt to provide such study by analyzing autopsy lung samples from patient who died of SARS and showed different degrees of severity of the pulmonary involvement. We performed real-time quantitative PCR analysis of 107 genes with functional roles in inflammation, coagulation, fibrosis and apoptosis; some key genes were confirmed at a protein expression level by immunohistochemistry and correlated to the degree of morphological severity present in the individual samples analyzed. Significant expression levels were identified for ANPEP (a receptor for CoV), as well as inhibition of the STAT1 pathway, IFNs production and CXCL10 (a T-cell recruiter). Other genes unassociated to date with ARDS/SARS include C1Qb, C5R1, CASP3, CASP9, CD14, CD68, FGF7, HLA-DRA, IGF1, IRF3, MALAT-1, MSR1, NFIL3, SLPI, USP33, CLC, GBP1 and TAC1. As a result, we proposed to therapeutically target some of these genes with compounds such as ANPEP inhibitors, SLPI and dexamethasone. Ultimately, this study may serve as a model for future, tissue-based analyses of fibroinflammatory conditions affecting the lung.     

Genotypic distribution of rotavirus strains causing severe gastroenteritis in Gyeonggi province,South Korea,from 2003 to 2005

Rotavirus was present in 1,367 of 7,060 stool samples (19.4%) collected in Gyeonggi province of South Korea from 2003 through 2005. The predominant genotypes were confirmed as G4/P2A[6] (19.0%) followed by G3/P1A[8] (15.6%), G2/P1B[4] (9.3%), and G1/P1A[8] (6.5%). The predominant types of rotavirus by year were G3/P[8] in 2003, G4/P[6] in 2004, and G1/P[8] in 2005. The prevalent rotavirus genotypes changed constantly from 2003 to 2005. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Role of Cholinergic and Cytokine Regulation of T Cell Function in Stimulation and Inhibition of Immune Reactions in Intoxication by Organophosphorus Compounds in Different Doses

Experiments on outbred albino rats showed that administration of acetylcholine and aceclidine in a dose of 0.1 LD₅₀ for 3 days and of dimethyl dichlorovinyl phosphate (organophosphorus compound) in a single dose of 0.05 LD₅₀ stimulated the function of Th1 and Th2 lymphocytes and cytokine production by these cells. Dimethyl dichlorovinyl phosphate in a single dose of 0.5 LD₅₀ produced an opposite effect. Acetylcholine and aceclidine stimulated activity of acetylcholinesterase in T cells, while dimethyl dichlorovinyl phosphate in a single dose of 0.5 LD₅₀ inhibited it. During acute intoxication, the organophosphorus compound, depending on the dose, can stimulate (acetylcholine effect) and inhibit the immune reactions (acetylcholinesterase inhibition of T cells).     

Changes in the Cytokine Profile and Reduced Function of Lymphocyte Subpopulations in Subacute Tetrachloromethane Poisoning

Experiments on outbred albino rats showed that subacute poisoning with tetrachloromethane in a total dose of 1.0 LD₅₀ appreciably decreased blood concentrations of cytokines (IFN-γ, IL-2, IL-4, IL-6, IL-10), reduced the IFN-γ/IL-4 ratio in comparison with the control, and suppressed the immune reactions, which attests to greater damage to Th1 compared to Th2 lymphocytes. Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 147, No. 1, pp. 55-57, January, 2009