scholarly journals Secondhand Smoke Decreased Excitability and Altered Action Potential Characteristics of Cardiac Vagal Neurons in Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Junqing Sun ◽  
Shiyue Pan ◽  
Emma Karey ◽  
Yi-Je Chen ◽  
Kent E. Pinkerton ◽  
...  

Background: Secondhand smoke (SHS), a major indoor pollutant, is a significant risk factor for cardiovascular morbidity and mortality including arrhythmias and sudden cardiac death. Exposure to SHS can produce autonomic imbalance, as evidenced by reduced heart rate variability (HRV)—a clinical metric of cardiac vagal regulation. Currently, the mechanisms through which SHS changes the vagal preganglionic neuronal inputs to the heart to produce this remains unknown.Objectives: To characterize the effect of SHS on both the excitability and action potential (AP) characteristics of anatomically identified cardiac vagal neurons (CVNs) in the nucleus ambiguus and examine whether SHS alters small conductance calcium-activated potassium (SK) channel activity of these CVNs.Methods: Adult male mice were exposed to four weeks of filtered air or SHS (3 mg/m3) 6 h/day, 5 day/week. Using patch-clamp recordings on identified CVNs in brainstem slices, we determined neuronal excitability and AP characteristics with depolarizing step- and ramp-current injections.Results: Four weeks of SHS exposure reduced spiking responses to depolarizing current injections and increased AP voltage threshold in CVNs. Perfusion with apamin (20 nM) magnified these SHS-induced effects, suggesting reduced SK channel activity may serve to minimize the SHS-induced decreases in CVNs excitability. Medium afterhyperpolarization (a measurement of SK channel activity) was smaller in the SHS group, further supporting a lower SK channel activity. AP amplitude, rise rate, fast afterhyperpolarization amplitude (a measurement of voltage-gated channel activity), and decay rate were higher in the SHS group at membrane voltages more positive to 0 mV, suggesting altered inactivation properties of voltage-dependent channels underlying APs.Discussion: SHS exposure reduced neuronal excitability of CVNs with compensatory attenuation of SK channel activity and altered AP characteristics. Neuroplasticity of CVNs could blunt regulatory cardiac vagal signaling and contribute to the cardiovascular consequences associated with SHS exposure, including reduced HRV.

2008 ◽  
Vol 295 (2) ◽  
pp. H632-H639 ◽  
Author(s):  
Chao-Yin Chen ◽  
Drin Chow ◽  
Nipavan Chiamvimonvat ◽  
Kathryn A. Glatter ◽  
Ning Li ◽  
...  

Exposure to secondhand smoke (SHS), a major indoor air pollutant, is linked to increased cardiovascular morbidity and mortality, including cardiac arrhythmias. However, the mechanisms underlying the epidemiological findings are not well understood. Impaired cardiac autonomic function, indexed by reduced heart rate variability (HRV), may represent an underlying cause. The present study takes advantage of well-defined short-term SHS exposure (3 days, 6 h/day) on HRV and the susceptibility to arrhythmia in mice. With the use of electrocardiograph telemetry recordings in conscious mice, HRV parameters in the time domain were measured during the night after each day of exposure and 24 h after 3 days of exposure to either SHS or filtered air. The susceptibility to arrhythmia was determined after 3 days of exposure. Exposure to a low concentration of SHS [total suspended particle (TSP), 2.4 ± 3.2; and nicotine, 0.3 ± 0.1 mg/m3] had no significant effect on HRV parameters. In contrast, the exposure to a higher but still environmentally relevant concentration of SHS (TSP, 30 ± 1; and nicotine, 5 ± 1 mg/m3) significantly reduced HRV starting after the first day of exposure and continuing 24 h after the last day of exposure. Moreover, the exposed mice showed a significant increase in ventricular arrhythmia susceptibility and atrioventricular block. The data suggest that SHS exposure decreased HRV beyond the exposure period and was associated with an increase in arrhythmia susceptibility. The data provide insights into possible mechanisms underlying documented increases in cardiovascular morbidity and mortality in humans exposed to SHS.


2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
H. Day-Poulsen ◽  
P. Thomas ◽  
J.-Y. Loze ◽  
L. Fortan ◽  
W. Kerselaers ◽  
...  

Background:Metabolic syndrome - a significant risk factor for cardiovascular morbidity and mortality - is twice as prevalent among psychiatric patients (21-63%) as general populations (20-24%). Although there is an inherent illness-associated metabolic risk, medications do contribute. Atypicals vary in metabolic risk from high (clozapine, olanzapine), moderate (risperidone, quetiapine) to low (aripiprazole, ziprasidone) (ADA, 2004). Few studies have comprehensively measured cardiovascular risk or directly compared antipsychotics. Limited controlled data show that antipsychotic-induced metabolic abnormalities may be reversible, rationalizing the switch to a lower-risk agent (DeNayer, 2004). Non-HDL-cholesterol encompasses all atherogenic cholesterols and provides a marker of CV risk: an increase of 29ng/dL in diabetics is associated with 50% increased risk (Jiang, 2004). Non-HDL-cholesterol is independently associated with increased risk of non-fatal myocardial infarction and angina.Aim:This study will provide cross-European data from 13 countries on MS rates in schizophrenia and will assess antipsychotic metabolic profiles and benefits of antipsychotic switching.Methods:In this ongoing, 16-week, open-label, European multicentre study, 258 schizophrenia patients treated for ≥3 months with olanzapine, risperidone or quetiapine and who have MS will be randomized to switch to aripiprazole (Week 1: 5mg/day; Week 2: 10mg/day; flexible 10-30mg/day after Week 2) or continue with previous antipsychotic. the primary objective is to demonstrate superiority of aripiprazole versus atypicals on mean percentage change of fasting non-HDL-cholesterol from baseline to Week 16.Conclusion:This study will provide the first direct and comprehensive comparison of metabolic risk with various atypicals in Europe and should impact the future management of schizophrenia.


Crisis ◽  
2014 ◽  
Vol 35 (5) ◽  
pp. 330-337 ◽  
Author(s):  
Cun-Xian Jia ◽  
Lin-Lin Wang ◽  
Ai-Qiang Xu ◽  
Ai-Ying Dai ◽  
Ping Qin

Background: Physical illness is linked with an increased risk of suicide; however, evidence from China is limited. Aims: To assess the influence of physical illness on risk of suicide among rural residents of China, and to examine the differences in the characteristics of people completing suicide with physical illness from those without physical illness. Method: In all, 200 suicide cases and 200 control subjects, 1:1 pair-matched on sex and age, were included from 25 townships of three randomly selected counties in Shandong Province, China. One informant for each suicide or control subject was interviewed to collect data on the physical health condition and psychological and sociodemographic status. Results: The prevalence of physical illness in suicide cases (63.0%) was significantly higher than that in paired controls (41.0%; χ2 = 19.39, p < .001). Compared with suicide cases without physical illness, people who were physically ill and completed suicide were generally older, less educated, had lower family income, and reported a mental disorder less often. Physical illness denoted a significant risk factor for suicide with an associated odds ratio of 3.23 (95% CI: 1.85–5.62) after adjusted for important covariates. The elevated risk of suicide increased progressively with the number of comorbid illnesses. Cancer, stroke, and a group of illnesses comprising dementia, hemiplegia, and encephalatrophy had a particularly strong effect among the commonly reported diagnoses in this study population. Conclusion: Physical illness is an important risk factor for suicide in rural residents of China. Efforts for suicide prevention are needed and should be integrated with national strategies of health care in rural China.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Junya Arai ◽  
Jun Kato ◽  
Nobuo Toda ◽  
Ken Kurokawa ◽  
Chikako Shibata ◽  
...  

Abstract Background Impairment of activities of daily living (ADL) due to hemorrhagic gastroduodenal ulcers (HGU) has rarely been evaluated. We analyzed the risk factors of poor prognosis, including mortality and impairment of ADL, in patients with HGU. Methods In total, 582 patients diagnosed with HGU were retrospectively analyzed. Admission to a care facility or the need for home adaptations during hospitalization were defined as ADL decline. The clinical factors were evaluated: endoscopic features, need for interventional endoscopic procedures, comorbidities, symptoms, and medications. The risk factors of outcomes were examined with multivariate analysis. Results Advanced age (> 75 years) was a significant predictor of poor prognosis, including impairment of ADL. Additional significant risk factors were renal disease (odds ratio [OR] 3.43; 95% confidence interval [CI] 1.44–8.14) for overall mortality, proton pump inhibitor (PPIs) usage prior to hemorrhage (OR 5.80; 95% CI 2.08–16.2), and heart disease (OR 3.05; 95% CI 1.11–8.43) for the impairment of ADL. Analysis of elderly (> 75 years) subjects alone also revealed that use of PPIs prior to hemorrhage was a significant predictor for the impairment of ADL (OR 8.24; 95% CI 2.36–28.7). Conclusion In addition to advanced age, the presence of comorbidities was a risk of poor outcomes in patients with HGU. PPI use prior to hemorrhage was a significant risk factor for the impairment of ADL, both in overall HGU patients and in elderly patients alone. These findings suggest that the current strategy for PPI use needs reconsideration.


Author(s):  
P. Dubey ◽  
J. Shrivastava ◽  
B.P. Choubey ◽  
A. Agrawal ◽  
V. Thakur

BACKGROUND: Neonatal hyperbilirubinemia is a common medical emergency in early neonatal period. Unconjugated bilirubin is neurotoxic and can lead to lifelong neurological sequelae in survivors. OBJECTIVE: To find out the association between serum bilirubin and neurodevelopmental outcome at 1 year of age using Development Assessment Scale for Indian Infants (DASII). METHODS: A prospective cohort study was conducted in the Department of Pediatrics of a tertiary care institution of Central India between January 2018 and August 2019. Total 108 term healthy neonates, with at least one serum bilirubin value of >15 mg/dl, were included. Subjects were divided into three groups based on the serum bilirubin; group 1: (15–20 mg/dl) –85(78.7%) cases, group 2: (20–25 mg/dl) –17(15.7%), and group 3: (>25 mg/dl) –6(5.5%). Developmental assessment was done using DASII at 3, 6, 9, 12 months of age. RESULTS: Out of 108 cases, 101(93.5%) received phototherapy, and 7(6.5%) received double volume exchange transfusion. Severe delay was observed in 5(4.6%) and mild delay in 2(1.9%) cases in the motor domain of DASII at one year. Severe delay in the motor domain was associated with mean TSB of 27.940±2.89 mg/dl and mild delay with mean TSB of 22.75±1.76 mg/dl (p = 0.001). On cluster analysis, delay was observed in locomotion 1 score in 11(13%) cases (p = 0.003) and manipulation score in 6(7.1%) cases in group 1. CONCLUSION: Increased serum bilirubin was a significant risk factor for the delayed neurodevelopment in babies with neonatal jaundice. Even a moderate level of bilirubin significantly affects the developmental outcome.


BMJ Open ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. e048590
Author(s):  
Kewei Wang ◽  
Yuanqi Wang ◽  
Ruxing Zhao ◽  
Lei Gong ◽  
Lingshu Wang ◽  
...  

ObjectiveThe objective of this study was to evaluate the influence of secondhand smoke (SHS) exposure during childhood on type 2 diabetes mellitus, hypertension, hyperlipidaemia and coronary heart disease among Chinese non-smoking women.MethodsIn this cross-sectional study, the SHS exposure data in childhood were obtained using a questionnaire survey. Self-reported childhood SHS exposure was defined as the presence of at least one parent who smoked during childhood.ResultsOf the 6522 eligible participants, 2120 Chinese women who had never smoked were assessed. The prevalence of SHS exposure in the entire population was 28.1% (596). SHS exposure during childhood was not significant for the standard risk factors of type 2 diabetes mellitus (p=0.628) and hypertension (p=0.691). However, SHS was positively associated with hyperlipidaemia (p=0.037) after adjusting for age, obesity, education status, physical activity, alcohol consumption, current SHS exposure status, diabetes mellitus and hypertension. In addition, childhood SHS increased the occurrence of coronary heart disease (p=0.045) among non-smokers after further adjusting for hyperlipidaemia.ConclusionSHS exposure during childhood is associated with prevalent hyperlipidaemia and coronary heart disease in adulthood among non-smoking Chinese women.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ting-Chun Huang ◽  
Po-Tseng Lee ◽  
Mu-Shiang Huang ◽  
Pei-Fang Su ◽  
Ping-Yen Liu

AbstractPremature atrial complexes (PACs) have been suggested to increase the risk of adverse events. The distribution of PAC burden and its dose–response effects on all-cause mortality and cardiovascular death had not been elucidated clearly. We analyzed 15,893 patients in a medical referral center from July 1st, 2011, to December 31st, 2018. Multivariate regression driven by ln PAC (beats per 24 h plus 1) or quartiles of PAC burden were examined. Older group had higher PAC burden than younger group (p for trend < 0.001), and both genders shared similar PACs distribution. In Cox model, ln PAC remained an independent risk factor for all-cause mortality (hazard ratio (HR) = 1.09 per ln PAC increase, 95% CI = 1.06‒1.12, p < 0.001). PACs were a significant risk factor in cause-specific model (HR = 1.13, 95% CI = 1.05‒1.22, p = 0.001) or sub-distribution model (HR = 1.12, 95% CI = 1.04‒1.21, p = 0.004). In ordinal PAC model, 4th quartile group had significantly higher risk of all-cause mortality than those in 1st quartile group (HR = 1.47, 95% CI = 1.13‒1.94, p = 0.005), but no difference in cardiovascular death were found in competing risk analysis. In subgroup analysis, the risk of high PAC burden was consistently higher than in low-burden group across pre-specified subgroups. In conclusion, PAC burden has a dose response effect on all-cause mortality and cardiovascular death.


Author(s):  
Leah Shelef ◽  
Jessica M Rabbany ◽  
Peter M Gutierrez ◽  
Ron Kedem ◽  
Ariel Ben Yehuda ◽  
...  

Past suicide attempts are a significant risk factor for future suicidality. Therefore, the present military-based study examined the past suicidal behavior of soldiers who recently made a severe suicide attempt. Our sample consisted of 65 active-duty soldiers (61.5% males), between the ages of 18 and 28 years old (M = 20.4, SD ± 1.3). The inclusion criterion was a recent severe suicide attempt, requiring at least a 24 h hospitalization. This sample was divided into two groups, according to previous suicidal behavior, namely whether their first suicide attempt was before or after enlistment (n = 25; 38.5% and n = 40; 61.5%, respectively). We then examined the lethality and intent of the recent event in regard to this division. Four measures were used to assess the subjects’ suicidal characteristics: the Columbia Suicide Severity Rating Scale, the Self-Harm Behavior Questionnaire, the Suicidal Behaviors Questionnaire-Revised, and the Beck Scale for Suicide Ideation. No significant difference in the severity of the suicide attempts (either actual or potential severity) were found between those who had suicide attempts before enlistment and those who had their first attempt in the service. As a matter of fact, most of the suicide attempts that occurred for the first time during military service had used a violent method (58.3%, n = 21). Finally, using multivariate analyses, we found that current thoughts and behavior, rather than past suicidality, was the strongest predictor for the lethality of suicide attempts.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tayla R. Penny ◽  
Yen Pham ◽  
Amy E. Sutherland ◽  
Joohyung Lee ◽  
Graham Jenkin ◽  
...  

AbstractPreclinical and clinical studies have shown that sex is a significant risk factor for perinatal morbidity and mortality, with males being more susceptible to neonatal hypoxic ischemic (HI) brain injury. No study has investigated sexual dimorphism in the efficacy of umbilical cord blood (UCB) cell therapy. HI injury was induced in postnatal day 10 (PND10) rat pups using the Rice-Vannucci method of carotid artery ligation. Pups received 3 doses of UCB cells (PND11, 13, 20) and underwent behavioural testing. On PND50, brains were collected for immunohistochemical analysis. Behavioural and neuropathological outcomes were assessed for sex differences. HI brain injury resulted in a significant decrease in brain weight and increase in tissue loss in females and males. Females and males also exhibited significant cell death, region-specific neuron loss and long-term behavioural deficits. Females had significantly smaller brains overall compared to males and males had significantly reduced neuron numbers in the cortex compared to females. UCB administration improved multiple aspects of neuropathology and functional outcomes in males and females. Females and males both exhibited injury following HI. This is the first preclinical evidence that UCB is an appropriate treatment for neonatal brain injury in both female and male neonates.


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