Individual differences in resting heart rate variability moderate thought suppression success

Individual differences in heart rate variability (HRV) at rest are thought to represent an individual's capacity for self‐regulation, but it remains unclear whether HRV predicts control over unwanted thoughts. The current study used a thought suppression paradigm in which participants recorded occurrences of a personally relevant intrusive thought over three monitoring periods. Among those instructed to suppress, higher levels of HRV were associated with greater declines in intrusions across the monitoring periods; no such relationship was found among those assigned to a control condition. Resting HRV also interacted with spontaneous thought suppression effort to predict intrusive thought frequency. In both cases, these HRV‐related differences in thought suppression success predicted the generalized distress symptoms common to depression and anxiety. These findings enhance understanding of the relationships between HRV and cognitive control and highlight how individual differences in self‐regulatory capacity impact thought suppression success and emotion regulation.     

Two‐year stability of individual differences in (para)sympathetic and HPA‐axis responses to public speaking in childhood and adolescence

Long‐term stability of individual differences in stress responses has repeatedly been demonstrated in adults, but few studies have investigated the development of stability in adolescence. The present study was the first to investigate the stability of individual differences in heart rate, parasympathetic (RMSSD, pNN50, HF), sympathetic (LF/HF, SC), and HPA‐axis (salivary cortisol) responses in a youth sample (8–19 years). Responses to public speaking were measured twice over 2 years. Stability was moderate for absolute responses and task delta responses of HR, RMSSD, pNN50, and HF. Stability was lower for SC and task delta responses of LF/HF and cortisol. Anticipation delta responses showed low stability for HR and cortisol. The latter was moderated by age or puberty, so that individual differences were more stable in more mature individuals. The results support the suggestion that stress responses may be reset during adolescence, but only for the HPA axis.     

It's not too late: The onset of the frontocentral P3 indexes successful response inhibition in the stop‐signal paradigm

The frontocentral P3 event‐related potential has been proposed as a neural marker of response inhibition. However, this association is disputed: some argue that P3 latency is too late relative to the timing of action stopping (stop‐signal reaction time; SSRT) to index response inhibition. We tested whether P3 onset latency is a marker of response inhibition, and whether it coincides with the timing predicted by neurocomputational models. We measured EEG in 62 participants during the stop‐signal task, and used independent component analysis and permutation statistics to measure the P3 onset in each participant. We show that P3 onset latency is shorter when stopping is successful, that it is highly correlated with SSRT, and that it coincides with the purported timing of the inhibition process (towards the end of SSRT). These results demonstrate the utility of P3 onset latency as a noninvasive, temporally precise neural marker of the response inhibition process.     

Ambulatory measurement of the ECG T‐wave amplitude

Ambulatory recording of the preejection period (PEP) can be used to measure changes in cardiac sympathetic nervous system (SNS) activity under naturalistic conditions. Here, we test the ECG T‐wave amplitude (TWA) as an alternative measure, using 24‐h ambulatory monitoring of PEP and TWA in a sample of 564 healthy adults. The TWA showed a decrease in response to mental stress and a monotonic decrease from nighttime sleep to daytime sitting and more physically active behaviors. Within‐participant changes in TWA were correlated with changes in the PEP across the standardized stressors (r = .42) and the unstandardized naturalistic conditions (mean r = .35). Partialling out changes in heart rate and vagal effects attenuated these correlations, but they remained significant. Ambulatory TWA cannot replace PEP, but simultaneous recording of TWA and PEP provides a more comprehensive picture of changes in cardiac SNS activity in real‐life settings.     

不同产地桔梗皂苷成分HPLC指纹图谱比较研究

目的：研究不同产地的桔梗药材皂苷指纹图谱,为桔梗的质量控制与生产提供参考依据。方法：采用DB101大孔树脂纯化精制桔梗皂苷,应用HPLC-ELSD法测定全国9省市自治区39批桔梗样品皂苷类化学成分指纹图谱。色谱条件：选用Agilent HC-C₈（4.6 mm×250 mm,5μm）柱,流动相为乙腈-0.5%乙酸系统,梯度洗脱;进样量6 μL;流速0.5 mL·min^-1;漂移管温度90℃;氮气流速1.2 mL·min^-1。结果：以内蒙古赤峰产区牛家营子镇6批样品共有指纹图谱为参照,发现各产区桔梗药材品质存在较大差异,其品质与各地桔梗栽培用种种源不规范和生态环境差异及药材干燥、贮藏等初加工方式密切相关。结论：在桔梗栽培生产中,应加强桔梗种源基地建设,规范用种,合理制定桔梗生产区划,规范桔梗产地加工。     

Forced expression of fibroblast growth factor 21 reverses the sustained impairment of liver regeneration in hPPARαPAC mice due to dysregulated bile acid synthesis

Peroxisome proliferator activated receptor α (PPARα) stimulates hepatocellular proliferation is species-specific. Activation of mouse, but not human, PPARα induces hepatocellular proliferation, hepatomegaly, and liver cancer. Here we tested the hypothesis that human and mouse PPARα affects liver regeneration differentially. PPARα-humanized mice (hPPARα^PAC) were similar to wild type mice in responding to fasting-induced PPARα signaling. However, these mouse livers failed to regenerate in response to partial hepatectomy (PH). The liver-to-body weight ratios did not recover even 3 months after PH in hPPARα^PAC. The mouse PPARα-mediated down-regulation of let-7c was absent in hPPARα^PAC, which might partially be responsible for impaired proliferation. After PH, hPPARα^PAC displayed steatosis, necrosis, and inflammation mainly in periportal zone 1, which suggested bile-induced toxicity. Quantification of hepatic bile acids (BA) revealed BA overload with increased hydrophobic BA in hPPARα^PAC. Forced FGF21 expression in partial hepatectomized hPPARα^PAC reduced hepatic steatosis, prevented focal necrosis, and restored liver mass. Compared to mouse PPARα, human PPARα has a reduced capacity to regulate metabolic pathways required for liver regeneration. In addition, FGF21 can compensate for the reduced ability of human PPARα in stimulating liver regeneration, which suggests the potential application of FGF21 in promoting hepatic growth in injured and steatotic livers in humans.     

Cumulative index of health deficiencies as a characteristic of long life

OBJECTIVES: To describe the accumulation of aging-associated health disorders using a cumulative measure known as a frailty index (FI) and to evaluate its ability to differentiate long- and short-life phenotypes as well as the FI's connection to aging-associated processes in older people. DESIGN: Retrospective cross-sectional and longitudinal studies. SETTING: The National Long-Term Care Survey (NLTCS) data that assessed health and functioning of U.S. older individuals (> or =65) in 1982, 1984, 1989, 1994, and 1999 were analyzed. The NLTCS sample in each survey represents a mixture of longitudinal and cross-sectional components. PARTICIPANTS: Approximately 5,000 individuals in each survey. MEASUREMENTS: A cumulative index of health and well-being deficiencies (disabilities, signs, diseases) was calculated as a count of deficits observed in an individual divided by the total number of all considered deficits. RESULTS: Men and women who died before the age of 75 and those who died after the age of 85 exhibited remarkably similar FI frequency patterns despite the 10-year age difference between age profiles in these samples. Long life is consistently characterized in longitudinal analyses by lower FIs. FI dynamics are found to be strongly sex sensitive. CONCLUSION: The FI appears to be a sensitive age-independent indicator of sex-specific physiological decline in aging individuals and a sex-specific discriminator of survival chances. The FI is a promising characteristic suitable for improving sex-sensitive forecasts of risks of adverse health outcomes in older people.     

Child Food Insecurity Is Associated with Energy Intake among Fourth- and Fifth-Grade Girls

BackgroundFood insecurity is associated with poor diet and obesity among adult women, but evidence among children is mixed, and few studies have examined differences between boys and girls.ObjectiveThis study examined the relationship between self-reported food insecurity and dietary intake among boys and girls.DesignCross-sectional survey data were used from the Children’s PowerPlay! Campaign evaluation.Participants and settingIn all, 3,547 fourth- and fifth-grade students (9 to 11 years old) from 44 San Diego-area elementary schools in 2012 completed diary-assisted 24-hour recalls and a questionnaire that included five questions from the Child Food Security Assessment.Main outcome measuresIndividual dietary components (including total energy, nutrients, and sugar-sweetened beverages), Healthy Eating Index-2010 scores, and meal patterns (such as meal sizes and missed meals) were derived from 24-hour recalls.Statistical analysesMultivariable linear and logistic regression models were used to estimate the relationships between food insecurity and diet characteristics.ResultsGirls with the highest food insecurity consumed 135 total kilocalories (P<0.005) and 60 snack kilocalories (P<0.05) more per day than girls with no food insecurity. These relationships were absent among boys.ConclusionsFood insecurity among girls in grades 4 and 5 was associated with higher energy intake. Findings support the need for further research to better understand the nature of this relationship and its implications for energy balance.