Why the P600 is not just a P300: the role of the basal ganglia.

One of the important issues in event-related brain potential research is whether the language-related P600 and the P300 oddball effect are distinct components or not. We addressed this question by testing 14 aphasic patients, half of them with lesions including the basal ganglia and half of them with temporo-parietal lesions, in both an auditory oddball task and an experiment with auditory presented verb inflection violations. Whereas both patient groups displayed a clear P300 effect in the oddball experiment, only the group with temporo-parietal lesions showed a P600 in the language experiment. These data indicate that the basal ganglia seem to play a crucial role in the modulation of the P600, but not of the P300 component.     

Heritability of lung function: a twin study among never-smoking elderly women

Most studies on lung function heritability have been conducted in smokers and non-smokers using cross-sectional study design. Smoking patterns may, however, confound the contribution of genetic factors. We investigated heritability of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio longitudinally, excluding the effects of smoking. A sample of never smoking female twins (n = 374), aged 63-76 at baseline, answered health questionnaires and attended spirometry in years 2000 and 2003. Bivariate structural equation modeling, restricted to adequate spirometry performances (baseline n = 339, follow-up n = 252), was used to estimate genetic and environmental influences on consecutive measurements of FEV1, FVC, and FEV1/FVC. The best-fitting models included additive genetic and non-shared environmental effects. Heritability estimates of 32% and 36% for FEV1, 41% and 37% for FVC, while 46% and 16% for FEV1/FVC were found at baseline and at follow-up. Genetic correlation between FEV1 and FEV1/FVC heritability estimates approached unity, whereas correlation between FVC estimates was 0.80. Environmental correlations were 0.69 for FEV1, 0.62 for FVC, and 0.07 for FEV1/FVC. In never smokers, additive genetic and non-shared environmental effects explain the inter-individual variations in FEV1, FVC, and FEV1/FVC. One third of the variation in FEV1 and FVC is explained by genetic and two thirds by environmental effects. Between 2000 and 2003, environmental effects on FEV1/FVC changed, and the proportion of variance explained by environmental effects increased remarkably. Genetic effects on FEV1 and FEV1/FVC are common to consecutive measurements, whereas at follow-up, new genetic factors explained 14% of the observed variance in FVC.     

Who controls the placebo? Introducing a Placebo Quality Checklist for pharmacological trials

Randomised placebo-controlled trials (RCT) are an invaluable tool for testing the efficacy of new treatment strategies. The choice of placebo in an RCT can affect not only patients' physical and psychological response to a particular intervention, but also the trial setting, the success of patient blinding to the intervention, and therefore the outcome of the study and the efficacy of treatment in general. Therefore the placebo is intrinsically tied to the trial's methodology and results. However, although placebos are an important component in randomised trials, their quality is often left unquestioned. A placebo which was not properly validated may even have specific effects that lead to false negative results. To address this deficit, we propose a measure of placebo quality using the term placebo to assess the physical aspect of a dummy treatment used in the placebo group of a randomised controlled trial (RCT). The Placebo Quality Checklist (PQC) described here may help investigators select an appropriate placebo and help both investigators and critical readers interpret the findings of studies with more care.     

Delayed enhancement cardiac magnetic resonance imaging reveals typical patterns of myocardial injury in patients with various forms of non-ischemic heart disease

BACKGROUND: Late gadolinium-hyperenhancement (LHE) on cardiac Magnetic Resonance Imaging (CMR) has been linked to cardiovascular risk in ischemic and non-ischemic heart disease. We aimed to systematically categorize LHE-patterns in a variety of non-ischemic heart diseases (NIHD) and to explore their relationship with left ventricular (LV) function. METHODS: In a retrospective database search, 156 patients with NIHD who exhibited LHE on CMR were identified. All images were re-analyzed stepwise. LHE was correlated to LV functional parameters. Cardiac magnetic resonance (CMR) was conducted on 1.5 T scanners. RESULTS: Typically, LHE spared the subendocardium. Consistent LHE-patterns were observed in myocarditis, hypertrophic and dilated cardiomyopathy and systemic vasculitis. No conclusive LHE-patterns were observed in patients with aortic stenosis, arterial hypertension, lupus erythematosus, sarcoidosis, ventricular arrhythmia and in a mixed subgroup of rare NIHDs. There was no significant relationship between LHE and ejection fraction. There was no correlation between enddiastolic volume and LHE in either myocarditis (P = 0.13) or dilated cardiomyopathy (P = 0.62). LHE was unrelated to LV-mass in aortic stenosis (P = 0.13) and hypertrophic cardiomyopathy (P = 0.38). CONCLUSIONS: Distinct LHE patterns exist in various NIHDs and their visualization may ultimately aid diagnosis. Unlike in ischemic heart disease, the structure-function relationship does not appear to be strong.     

The roles of "face" and "non-face" areas during individual face perception: evidence by fMRI adaptation in a brain-damaged prosopagnosic patient

Two regions in the human occipito-temporal cortex respond preferentially to faces: 'the fusiform face area' ('FFA') and the 'occipital face area' ('OFA'). Whether these areas have a dominant or exclusive role in face perception, or if sub-maximal responses in other visual areas such as the lateral occipital complex (LOC) are also involved, is currently debated. To shed light on this issue, we tested normal participants and PS, a well-known brain-damaged patient presenting a face-selective perception deficit (prosopagnosia) [Rossion, B., Caldara, R., Seghier, M., Schuller, A. M., Lazeyras, F., Mayer, E. (2003). A network of occipito-temporal face-sensitive areas besides the right middle fusiform gyrus is necessary for normal face processing. Brain 126 2381-2395.], with functional magnetic resonance imaging (fMRI). Of particular interest, the right hemisphere lesion of the patient PS encompasses the 'OFA' but preserves the 'FFA' and LOC [Sorger, B., Goebel, R., Schiltz, C., Rossion, B. (2007). Understanding the functional neuroanatomy of acquired prosopagnosia. NeuroImage 35, 836-852.]. Using fMRI-adaptation, we found a dissociation between the coding of individual exemplars in the structurally intact 'FFA', which was impaired for faces but preserved for objects in the patient PS's brain. Most importantly, a larger response to different faces than repeated faces was found in the ventral part of the LOC both for normals and the patient, next to the right hemisphere lesion. Thus, following prosopagnosia, areas that do not respond preferentially to faces such as the ventral part of the LOC (vLOC) may still be recruited for compensatory or residual individual face perception. Overall, these observations indicate that several high-level visual areas in the human brain contribute to individual face perception. However, a subset of these areas in the right hemisphere, those responding preferentially to faces ('FFA' and 'OFA'), appear to be critical for this function.     

Relation between myocardial edema and myocardial mass during the acute and convalescent phase of myocarditis – a CMR study

Background

Myocardial edema is a substantial feature of the inflammatory response in human myocarditis. The relation between myocardial edema and myocardial mass in the course of healing myocarditis has not been systematically investigated. We hypothesised that the resolution of myocardial edema as visualised by T2-weighted cardiovascular magnetic resonance (CMR) is associated with a decrease of myocardial mass in steady state free precession (SSFP)-cine imaging.

Methods

21 patients with acute myocarditis underwent CMR shortly after onset of symptoms and 1 year later. For visualization of edema, a T2-weighted breath-hold black-blood triple-inversion fast spin echo technique was applied and the ratio of signal intensity of myocardium/skeletal muscle was assessed. Left ventricular (LV) mass, volumes and function were quantified from biplane cine steady state free precession images.11 healthy volunteers served as a control group for interstudy reproducibility of LV mass.

Results

In patients with myocarditis, a significant decrease in LV mass was observed during follow-up compared to the acute phase (156.7 ± 30.6 g vs. 140.3 ± 28.3 g, p < 0.0001). The reduction of LV mass paralleled the normalization of initially increased myocardial signal intensity on T2-weighted images (2.4 ± 0.4 vs. 1.68 ± 0.3, p < 0.0001).In controls, the interstudy difference of LV mass was lower than in patients (5.1 ± 2.9 g vs. 16.3 ± 14.2 g, p = 0.02) resulting in a lower coefficient of variability (2.1 vs 8.9%, p = 0.04).

Conclusion

Reversible abnormalities in T2-weighted CMR are paralleled by a transient increase in left ventricular mass during the course of myocarditis. Myocardial edema may be a common pathway explaining these findings.     

Pseudoradicular and radicular low-back pain--a disease continuum rather than different entities? Answers from quantitative sensory testing

To assess whether pseudoradicular low-back pain may be associated with subclinical sensory deficits in the distal extremity, we applied the quantitative sensory testing protocol of the German Research Network on Neuropathic Pain (DFNS) in 15 patients with pseudoradicular pain distribution. Sixteen age- and gender-matched healthy control subjects as well as 12 patients with radicular pain syndromes (L4-S1) were studied with the same protocol. Radicular pain was diagnosed using clinical criteria (pain radiation beyond the knee, motor-, sensory-, or reflex deficits, positive Laségue's test). Z-score QST profiles revealed a selective loss of vibration detection, detection of v. Frey hair contact, and cold detection in the affected dermatomes in the radicular pain group. The contralateral dermatome was also affected, but to a lesser degree. In patients with pseudoradicular pain, the sensory profile was similar, but sensory loss was less pronounced than in the radicular pain patients. There was no significant difference between the two patient groups. Vibration detection was the most sensitive parameter with 73% abnormal values in radicular and 47% in pseudoradicular cases. These data verified the sensitivity of QST to detect sensory loss in radicular compression syndromes, and support a neuropathic component in low-back pain with radiculopathy. In contrast to some central pain syndromes this sensory loss involved predominantly large fiber functions. The subclinical sensory loss in pseudoradicular cases suggests that these patients may also have a neuropathic component of their chronic pain. The spatial incongruence of pain and sensory loss in pseudoradicular pain, however, may also indicate that the two are not causally related.     

Deletion of the acid-sensing ion channel ASIC3 prevents gastritis-induced acid hyperresponsiveness of the stomach-brainstem axis

Gastric acid challenge of the rat and mouse stomach is signalled to the brainstem as revealed by expression of c-Fos. The molecular sensors relevant to the detection of gastric mucosal acidosis are not known. Since the acid-sensing ion channels ASIC2 and ASIC3 are expressed by primary afferent neurons, we examined whether knockout of the ASIC2 or ASIC3 gene modifies afferent signalling of a gastric acid insult in the normal and inflamed stomach. The stomach of conscious mice (C57BL/6) was challenged with intragastric HCl; two hours later the activation of neurons in the nucleus tractus solitarii (NTS) of the brainstem was visualized by c-Fos immunocytochemistry. Mild gastritis was induced by addition of iodoacetamide (0.1%) to the drinking water for 7 days. Exposure of the gastric mucosa to HCl (0.25M) caused a 3-fold increase in the number of c-Fos-positive neurons in the NTS. This afferent input to the NTS remained unchanged by ASIC3 knockout, whereas ASIC2 knockout augmented the c-Fos response to gastric HCl challenge by 33% (P<0.01). Pretreatment of wild-type mice with iodoacetamide induced mild gastritis, as revealed by increased myeloperoxidase activity, and enhanced the number of NTS neurons responding to gastric HCl challenge by 41% (P<0.01). This gastric acid hyperresponsiveness was absent in ASIC3 knockout mice but fully preserved in ASIC2 knockout mice. The current data indicate that ASIC3 plays a major role in the acid hyperresponsiveness associated with experimental gastritis. In contrast, ASIC2 appears to dampen acid-evoked input from the stomach to the NTS.     

Beurteilung myeloischer und lymphatischer Neoplasien bei beruflicher Benzolexposition

BACKGROUND AND PURPOSE: Benzene-caused hematologic diseases can be recognized as occupational diseases (ODs) if they fulfill the legal requirements specified under No. 1303 of the appendix of the German ordinance on ODs. The aim of this study is to analyze the most important criteria that determined whether these diseases were recognized or rejected as ODs according to No. 1303 in 2006. METHODS: In 2006, 70 suspected cases of OD No. 1303 reported in North Rhine-Westphalia were examined in terms of diagnosis, notifiers, cumulative benzene exposures, professions, coexposures, delays in notification, latency periods, interim periods, and recognition criteria. RESULTS: 70 benign and malignant diseases of myeloid and lymphoid origin were reported as suspected ODs, among them 41 B-cell non-Hodgkin's lymphomas (B-cell NHL). Latency periods ranged between 14 and 57 years (median 37; mean 36.3+/-11.4; n=45), estimated cumulative benzene exposures varied from 0 to 144 ppm-years (median 12; mean 11.4+/-22.8; n=59). Four of 70 suspected cases were recognized as OD No. 1303. In 37 cases (52.9%), the nature of the disease was assessed as being nontypical of OD No. 1303, in 50 cases (71.4%), no sufficient benzene exposure could be found. Mature-cell NHL and Hodgkin's lymphoma were not recognized as OD. Cumulative benzene exposures相似文献