Plasma Neuropeptide Y Levels in Vasovagal Syncope in Children.

BACKGROUND: Vasovagal syncope (VVS) is the most common cause of syncope in children. Neuropeptide Y (NPY) plays an important role in the regulation of blood pressure (BP), as well as myocardial contractility. This study aimed to explore the role of plasma NPY in VVS in children. METHODS: Fifty-six children who were diagnosed with VVS (VVS group) using head-up tilt test (HUT) and 31 healthy children who were selected as controls (control group) were enrolled. Plasma NPY concentrations were detected. The independent t-test was used to compare the data of the VVS group with those of the control group. The changes in plasma NPY levels in the VVS group during the HUT, as well as hemodynamic parameters, such as heart rate (HR), BP, total peripheral vascular resistance (TPVR), and cardiac output (CO), were evaluated using the paired t-test. Furthermore, the correlations between plasma NPY levels and hemodynamic parameters were analyzed using bivariate correlation analysis. RESULTS: The BP, HR, and plasma NPY (0.34 ± 0.12 pg/ml vs. 0.46 ± 0.13 pg/ml) levels in the supine position were statistically low in the VVS group compared to levels in the control group (all P < 0.05). Plasma NPY levels were positively correlated with the HR (Pearson, R = 0.395, P < 0.001) and diastolic BP (Pearson, R = 0.311, P = 0.003) when patients were in the supine position. When patients in the VVS group were in the supine position, elevated TPVR (4.6 ± 3.7 mmHg·min-1·L-1 vs. 2.5 ± 1.0 mmHg·min-1·L-1, respectively, P < 0.001; 1 mmHg = 0.133 kPa) and reduced CO (1.0 ± 0.7 L/min vs. 2.4 ± 1.3 L/min, respectively, P < 0.001) were observed in the positive-response period compared with baseline values. The plasma NPY levels were positively correlated with TPVR (Spearman, R = 0.294, P = 0.028) but negatively correlated with CO in the positive-response period during HUT (Spearman, R = -0.318, P = 0.017). CONCLUSIONS: Plasma NPY may contribute to the pathogenesis of VVS by increasing the TPVR and decreasing the CO during orthostatic regulation.

Vitamin D and Cardiovascular Risk in Children.

OBJECTIVE: Vitamin D is a group of fat-soluble molecules that are structurally similar to steroids. Emerging data have led to the hypothesis that Vitamin D plays a role in the regulation of many physiological processes beyond calcium and phosphorus homeostasis. With this review, we aimed to summarize the changes in Vitamin D levels in children with cardiovascular diseases based on the literature. In addition, we also reviewed the potential mechanisms underlying cardiovascular diseases associated with Vitamin D deficiency or insufficiency. DATA SOURCES: The articles in English were searched from PubMed (1968-2016) and EMBASE (1991-2016), with the keywords of "Vitamin D AND cardiovascular diseases" and "Vitamin D AND children." STUDY SELECTION: Original articles and critical reviews about Vitamin D and cardiovascular risk in children were selected for review. Researches focused on adults were excluded. RESULTS: Studies have shown that several pediatric cardiovascular diseases may be associated with Vitamin D deficiency or insufficiency, including hypertension, orthostatic intolerance, and Kawasaki disease. CONCLUSIONS: Vitamin D may play a role in the regulation of the cardiovascular system. Further investigation would hopefully disclose the usefulness of Vitamin D as a biomarker for cardiovascular diseases in children.

Pathogenesis and Individualized Treatment for Postural Tachycardia Syndrome in Children.

OBJECTIVE: Postural tachycardia syndrome (POTS) is one of the major causes of orthostatic intolerance in children. We systematically reviewed the pathogenesis and the progress of individualized treatment for POTS in children. DATA SOURCES: The data analyzed in this review are mainly from articles included in PubMed and EMBASE. STUDY SELECTION: The original articles and critical reviews about POTS were selected for this review. RESULTS: Studies have shown that POTS might be related to several factors including hypovolemia, high catecholamine status, abnormal local vascular tension, and decreased skeletal muscle pump activity. In addition to exercise training, the first-line treatments mainly include oral rehydration salts, beta-adrenoreceptor blockers, and alpha-adrenoreceptor agonists. However, reports about the effectiveness of various treatments are diverse. By analyzing the patient's physiological indexes and biomarkers before the treatment, the efficacy of medication could be well predicted. CONCLUSIONS: The pathogenesis of POTS is multifactorial, including hypovolemia, abnormal catecholamine state, and vascular dysfunction. Biomarker-directed individualized treatment is an important strategy for the management of POTS children.

Structures, properties and nature of DMSO-XY (XY=ClF and BrF) complexes: redshift and blueshift of S=O stretch.

The DMSO-XY (XY=ClF and BrF) complexes have been investigated with quantum chemical calculations. In general, two minima complexes were found, one with an O···X halogen bond and the other one with a S···X halogen bond. The former is more stable than the latter. Additionally, one first order saddle point complex was also observed. The interaction energies in the S complexes suffer a prominent influence from the calculation methods. At the CCSD(T)/aug-cc-pVDZ level, the interaction energies are calculated to be -9.19 and -12.73 kcal/mol for the Cl and Br global minima, respectively. Both complexes have also been evidenced to be stable at room temperature. The SO stretch vibration exhibits a red shift at the global minimum but a blue shift at the local minimum, whereas the CSC and CH stretch vibrations move to high frequency in both cases. The energy decomposition analyses indicate that the electrostatic interaction plays a dominant role in stabilizing these halogen-bonded complexes.

Correlation of increased hippocampal Sumo3 with spatial learning ability in old C57BL/6 mice.

Age-related impairment of learning and memory is a common phenomenon in humans and animals, yet the underlying mechanism remains unclear. We hypothesize that a small ubiquitin-related modifier (Sumo) might correlate with age-related loss of learning and memory. To test this hypothesis, the present study evaluated age-related spatial learning and memory in C57BL/6 mice (25 aged 7 months and 21 aged 25 months) using a radial six-arm water maze (RAWM). After the behavioral test, the protein expression of Sumo3 was determined in different brain regions using Western blotting. The results showed that the 25-month-old mice had longer latency and a higher number of errors in both learning and memory phases in the RAWM task than the 7-month-old mice. Compared to the latter, the former's level of Sumo3 protein was significantly increased in the dorsal and ventral hippocampus. For the 25-month-old mice, the number of errors and the latency in the learning phase negatively correlated with the Sumo3 level in the dorsal hippocampus. These results suggest that increased Sumo3 in the hippocampus may be correlated with spatial learning ability in old C57BL/6 mice.

Identification of nose-to-brain homing peptide through phage display.

Brain delivery of drug molecules through the nasal passage represents a viable approach for bypassing the blood-brain barrier (BBB) but remains a major challenge due to lack of efficient homing carriers. To screen for potential peptides with the ability to transport into the brain via the nasal passage, we applied a C7C phage peptide display library (Ph.D.-C7C) intra-nasally to anesthetized rats and recovered phage from the brain tissue 45 min after phage administration. After three rounds of panning, 10 positive phage clones were selected and sequenced. Clone7, which exhibited highest translocation efficiency, was chosen for further studies. After nasal administration, Clone7 entered the brain within 30 min and exhibited translocation efficiency about 50-fold higher than a random phage. A 11-amino acid synthetic peptide derived from the displayed sequence of Clone7 (ACTTPHAWLCG) efficiently inhibited the nasal-brain translocation of Clone7. Both phage recovery results and fluorescent microscopy images revealed the presence of many more Clone7 phage in the brain than in the liver, kidney and other internal organs after the nasal administration, suggesting that Clone7 bypassed the BBB and entered brain directly. Furthermore, both Clone7 and the ACTTPHAWLCG peptide were found to be heavily distributed along the olfactory nerve after the nasal administration, further suggesting a direct passage route into the brain via the olfactory region. These results demonstrated the feasibility of using the in vivo phage display approach for selecting peptides with the nose-to-brain homing capability and may have implications for the development of novel targeting carriers useful for brain delivery.