Human chorionic gonadotrophin (hCG) enhances immunity against L. tropica by stimulating human macrophage functions

During pregnancy, there are important changes in hormone levels such as the huge production of human chorionic gonadotropin (hCG), which is supposed to influence the immune system. The aim of this study was to investigate the effect of hCG on immune response against Leishmania, through the evaluation of the functions of human macrophages infected with L. tropica. This study demonstrated that hCG significantly increased the NO production by rHu‐IFNγ‐primed macrophages then infected with L. tropica, which was correlated with decrease in the number of infected macrophages as well as the number of amastigotes per macrophage in a dose‐dependent manner; however, the greatest effect was shown with the 250 U/mL concentration. The addition of the same concentration of hCG to rHu‐IFNγ‐primed macrophages caused also a major increase in both IL‐6 and IL‐12p40 production. In conclusion, hCG enhances different macrophage functions involved in immunity against L. tropica.     

Technology-aided programs to support exercise of adaptive head responses or leg-foot and hands responses in children with multiple disabilities

Objective: Assessing the effectiveness of technology-aided programs to help three children with multiple disabilities exercise adaptive head or leg-foot and hands responses independently.

Method: The response selected for the two children included in Study I was head rotation (i.e. movements of at least 25 degrees to the left that could start from a full right position as well as from other positions). The responses selected for the child included in Study II involved forward movement of the left leg-foot and forward movement of his hand(s) to touch objects. Tilt or optic microswitches were used to monitor the responses and a computer system regulated the stimuli contingent on them.

Results: The responses targeted in the two studies showed large frequency increases during the intervention phases of the studies (i.e. when followed by stimulation).

Conclusion: Technology-aided programs can be a useful resource to help children with multiple disabilities exercise relevant responses independently.     

Delaying forelimb responses by microstimulation of macaque V1

Electrical microstimulation of macaque V1 has previously been shown to delay saccadic eye movements made to a punctate visual target placed in the receptive field of the stimulated neurons. It remains unclear whether this delay effect is specific to the oculomotor system or whether the effect can be demonstrated in the skeletomotor system as well. To address this question, a rhesus monkey was trained to depress a left or right lever with its respective hand in response to a visual target presented in the left or right hemifield. On 50% of trials, a 100 ms train of stimulation consisting of 100 μA, 0.2-ms anode-first pulses was delivered to the neurons before the onset of the visual target. Stimulation of V1 delayed the execution of the lever response when the visual target was positioned within the receptive field of the stimulated neurons. We suggest that the delay effect induced by microstimulation of V1 is largely due to a disruption of the visual signal as it is transmitted along the geniculostriate pathway.     

IAPS includes photographs that elicit low-arousal physiological responses in healthy volunteers

This article describes pleasant IAPS pictures that elicit low-arousal rather than the high-arousal physiological responses previously reported in the literature. Thirty-two International Affective Picture System (IAPS) photographs were grouped into 4 sets of 8 photographs: highly pleasant-arousing (sexual content and adventures), highly pleasant-relaxing pictures (landscapes, flowers or babies), neutral on both valence/arousal, and highly unpleasant-arousing ones. These stimuli were shown to 24 healthy Brazilian University students (12 males) who had their physiological responses recorded [corrugator and zygomatic facial electromyography activity, skin conductance, heart rate, and peripheral temperature]. Zygomatic EMG differentiated low-arousal pleasant photographs from high-arousal pleasant stimuli of the same valence.     

Children's skin conductance level and reactivity: Are these measures stable over time and across tasks?

The stability of children's skin conductance level during baselines (SCL-B) and SCL reactivity (SCL-R) were examined longitudinally. During two laboratory sessions (T1 and T2), 2 years apart, children participated in procedures during which they were exposed to two stressors namely exposure to an audiotaped conflict between two adults, and a problem solving task. Children ranged in age between 6 and 13 years at T1. Measures of SCL-B and SCL-R during the two stressors were obtained. Findings illustrated the temporal stability of SCL-B and SCL-R to the star-tracing task over 2 years. Results also indicated stability in SCL-R to the two stressors (argument and problem-solving) examined within the same session at either T1 or T2. These results support the proposition that SCL-B and SCL-R constitute stable individual differences at the ages examined, and build on the scant longitudinal literature on psychophysiological development in children.     

Leaf saponins of Quillaja brasiliensis enhance long-term specific immune responses and promote dose-sparing effect in BVDV experimental vaccines

Saponin-based adjuvants are promising adjuvants that enhance both humoral and T-cell-mediated immunity. One of the most used natural products as vaccine adjuvants are Quillaja saponaria bark saponins and its fraction named Quil A®. Despite that, its use has been restricted for human use due to safety issues. As an alternative, our group has been studying the congener species Quillaja brasiliensis saponins and its performance as vaccine adjuvants, which have shown to trigger humoral and cellular immune responses comparable to Quil A® but with milder side effects. Here, we studied a semi purified aqueous extract (AE) and a previously little characterized saponin-enriched fraction (QB-80) from Q. brasiliensis as vaccine adjuvants and an inactivated virus (bovine viral diarrhea virus, BVDV) antigen co-formulated in experimental vaccines in mice model. For the first time, we show the spectra pattern of the Q. brasiliensis saponins by MALDI-TOF, a novel and cost-effective method that could be used to characterize different batches during saponins production. Both AE and QB-80 exhibited noteworthy chemical similarities to Quil A®. In addition, the haemolytic activity and toxicity were assessed, showing that both AE and QB-80 were less toxic than Quil A®. When subcutaneously inoculated in mice, both fractions promoted long-term strong antibody responses encompassing specific IgG1 and IgG2a, enhanced the avidity of IgG antibodies, induced a robust DTH reaction and significantly increased IFN-ɣ production in T CD4⁺ and T CD8⁺ cells. Furthermore, we have proven herein that AE has the potential to promote dose-sparing, substantially reducing the dose of antigen required for the BVDV vaccines and still eliciting a mixed Th1/Th2 strong immune response. Based on these results, and considering that AE is a raw extract, easier and cheaper to produce than commercially available saponins, this product can be considered as candidate to be escalated from experimental to industrial uses.