Neural response dynamics of spiking and local field potential activity depend on CRT monitor refresh rate in the tree shrew primary visual cortex

Entrainment of neural activity to luminance impulses during the refresh of cathode ray tube monitor displays has been observed in the primary visual cortex (V1) of humans and macaque monkeys. This entrainment is of interest because it tends to temporally align and thus synchronize neural responses at the millisecond timescale. Here we show that, in tree shrew V1, both spiking and local field potential activity are also entrained at cathode ray tube refresh rates of 120, 90, and 60 Hz, with weakest but still significant entrainment even at 120 Hz, and strongest entrainment occurring in cortical input layer IV. For both luminance increments ("white" stimuli) and decrements ("black" stimuli), refresh rate had a strong impact on the temporal dynamics of the neural response for subsequent luminance impulses. Whereas there was rapid, strong attenuation of spikes and local field potential to prolonged visual stimuli composed of luminance impulses presented at 120 Hz, attenuation was nearly absent at 60-Hz refresh rate. In addition, neural onset latencies were shortest at 120 Hz and substantially increased, by ～15 ms, at 60 Hz. In terms of neural response amplitude, black responses dominated white responses at all three refresh rates. However, black/white differences were much larger at 60 Hz than at higher refresh rates, suggesting a mechanism that is sensitive to stimulus timing. Taken together, our findings reveal many similarities between V1 of macaque and tree shrew, while underscoring a greater temporal sensitivity of the tree shrew visual system.     

Tolerance versus immune response — MicroRNAs as important elements in the regulation of the HLA-G gene expression

HLA-G is a class Ib HLA which has gained much attention due to its multiple functions on the immune system. HLA-G exerts several immunomodulatory effects, being beneficially implicated in embryo implantation and fetal survival but, conversely, being potentially detrimental in tumors and viral infections. Such a two-edged sword behavior suggest that HLA-G expression is under tight regulation. However, to date, little is known about the regulation of this gene and previous works have been unable to well correlate HLA-G regulation at the mRNA level with the polymorphic variants at the genomic level. Here we present the hypothesis that an element, which was until now neglected, might play a role in HLA-G expression regulation: MicroRNAs might participate in the regulation of the HLA-G gene expression through a putative microRNA binding site at its 3′ UTR region. Inside the 20 nt region of this microRNA binding site lies a C/G polymorphism, which was shown to be responsible for differential microRNA binding affinity and translation suppression. The role of microRNA binding on the regulation of HLA-G gene expression (and therefore on tolerance versus immune response) can be easily tested through relatively simple steps: Confirming the expression of those three complementary microRNAs in human cells which express HLA-G, followed by examination of the correlation between HLA-G mRNA and protein production controlling for HLA-G genotypes and microRNA levels; finally, selective inhibition of microRNA activity with anti-sense oligos restoring HLA-G production would access microRNA influence on HLA-G expression which, if confirmed, might help in the development of strategies to the management of several conditions in which HLA-G is involved, including pregnancy complications, transplantation, and cancer.     

A cross-cultural comparison between samples of Brazilian and German children with ADHD/HD using the Child Behavior Checklist

Introduction This study aims to assess cross-cultural similarities and differences in broadband psychopathology in two naturalistic clinical samples of children diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) combined type according to DSM-IV criteria or with Hyperkinetic Disorder (HD) according to ICD-10 criteria. Methods We compared two clinical samples of children with ADHD combined type (Brazil, N = 248) and HD (Germany; N = 154) to controls (Brazil N = 71; Germany N = 135) using the Child Behavior Checklist (CBCL). ROC-curves (Receiver Operating Characteristic) were determined to evaluate the discriminating validity of the CBCL Attention Problem scale. A two-factorial ANOVA was computed across all 8 scales of the CBCL. Results Although Brazilian parents reported significantly higher scores on all CBCL scales than German parents (P < 0.05), a similar CBCL profile was detected in both cultures. Conclusion Despite the use of different diagnostic systems (DSM-IV vs. ICD-10) and the presence of other clinical differences, the similar broadband psychopathological profile of the CBCL in the two samples provides evidence that dimensional symptoms associated with the categorical diagnosis of ADHD combined type might be comparable in two clinical settings with diverse cultural background.     

Therapeutic use of surfactant components in allergic asthma

Pulmonary surfactant is a complex mixture of lipids and proteins that reduces the surface tension at the air-liquid interface. In addition to its biophysical function, some surfactant components play an important role for the innate and adaptive immunity of the lung. A negative modulation of the surfactant function was observed in allergic asthma leading to the assumption that the therapeutic application of surfactant components might be beneficial in this disease. So far, there are a number of preclinical and already some clinical studies demonstrating various effects of different surfactant components that were administered with preventive or therapeutic aim in allergic asthma. This review summarizes the current knowledge on the possibilities to treat allergic asthma with surfactant components.     

Daily profile of circulating C-type natriuretic peptide in pre-ascitic cirrhosis and in normal subjects: relationship with renal function

OBJECTIVE: To investigate whether the C-type natriuretic peptide (CNP) has a role in the regulation of fluid and sodium homeostasis in normal subjects and in pre-ascitic cirrhotic patients. MATERIAL AND METHODS: The daily profile of CNP plasma levels was assessed by serial measurements (0700 h, 0900 h, 1800 h, 2300 h) in 10 pre-ascitic cirrhotic outpatients (age 56+/-4 years) and in 10 age-matched healthy controls (54+/-2 years) on a normal sodium diet (150 mmol/day) while carrying on their usual activities (mobile from 0700 h to 2200 h), after an equilibration period of 5 days. Daily diuresis and natriuresis were also monitored. RESULTS: Mean daily CNP was comparable in cirrhotic and healthy subjects (3.64+/-0.32 versus 3.20+/-0.20 pg/ml; p=0.139); CNP concentration showed a tendency towards a circadian fluctuation in healthy subjects (p=0.053) but not in patients (p=0.171). Mean daily CNP concentration significantly correlated with 24-h natriuresis (r=0.709; p=0.022) and urine volume (r=0.745; p=0.013) in patients but not in healthy subjects. CONCLUSIONS: CNP plasma levels appear to play a role in the water-sodium balance regulation in patients with pre-ascitic cirrhosis.     

Immunocompetent children account for the majority of complications in childhood herpes zoster

In a 2-year-long active surveillance conducted in all German pediatric hospitals, the incidence of hospitalization because of herpes zoster and the clinical picture of complications in children were assessed. Herpes zoster resulted in hospitalization of 244 children, 78 of whom were considered to be immunocompromised. Zoster ophthalmicus (n=29), meningoencephalitis (n=22), and zoster oticus (n=23) (11 cases had Ramsay Hunt syndrome) accounted for 59% of all complications (n=115). The incidence of hospitalization suggests that at least 1 in every 100 children with herpes zoster is hospitalized and that at least 1 in every 250 immunocompetent children with herpes zoster is hospitalized with complications.