Pathophysiological impact of cigarette smoke exposure on the cerebrovascular system with a focus on the blood-brain barrier: expanding the awareness of smoking toxicity in an underappreciated area

The effectiveness of family counselling on reducing exposure to secondhand smoke at home among pregnant women in Iran

INTRODUCTION

Pregnant women are often exposed to secondhand smoke that affects them and their child. Our aim was to determine the effectiveness of family counselling using the BASNEF model on reducing exposure to secondhand smoke at home among pregnant women.

METHODS

A quasi-experimental study was conducted on 103 pregnant women exposed to secondhand smoke. They were selected using a multi-stage cluster sampling method and allocated into intervention (50 people) and control (53 people) groups. Four family counseling sessions using the BASNEF model were held for the intervention group while the control group received routine care. The outcomes were measured before and at one month after the last session of counselling.

RESULTS

In the timeframe before the intervention, the number of days in which there was reported exposure to secondhand smoke was 5.08 ± 1.1 in the intervention group, significantly decreasing to 3.5 ± 1.6 after the intervention (p<0.001). No significant change was observed in the control group (p=0.1). Also, the mean scores of all constructs of the BASNEF model increased significantly after the intervention compared to those of the control group (p<0.05).

CONCLUSIONS

Family counseling had a positive effect on decreasing the exposure to secondhand smoke at home among a sample of pregnant women. The BASNEF model is useful for implementing educational care programs in these settings.

The cerebrovascular and neurological impact of chronic smoking on post-traumatic brain injury outcome and recovery: an in vivo study

BACKGROUND

Traumatic brain injury (TBI) is among the most prevalent causes of cerebrovascular and neurological damage worldwide. To this end, tobacco smoke (TS) has been shown to promote vascular inflammation, neurovascular impairments, and risk of cerebrovascular and neurological disorders through oxidative stress (OS) stimuli targeting the blood-brain barrier (BBB) endothelium among others. It has been recently suggested that premorbid conditions such as TS may exacerbate post-TBI brain damage and impact recovery.

METHODS

Our study investigated the mechanisms underlying the exacerbation of TBI injury by TS using a weight drop model. For this purpose, male C57BL/6J mice, age range 6-8 weeks, were chronically exposed to premorbid TS for 3 weeks. Test animals were then subjected to TBI by guided vertical head weight drop using a 30 g metal weight free felling from an 80 cm distance before reaching the target. We analyzed the physical activity and body weight of the mice before TBI and 1 h, 24 h, and 72 h post-injury. Finally, mice were sacrificed to collect blood and brain samples for subsequent biochemical and molecular analysis. Western blotting was applied to assess the expression of Nrf2 (a critical antioxidant transcription factor) as well as tight junction proteins associated with BBB integrity including ZO-1, Occludin, and Claudin-5 from brain tissues homogenates. Levels of NF-kB (a pro-inflammatory transcript factor which antagonizes Nrf2 activity) and pro-inflammatory cytokines IL-6, IL-10, and TNF-α were assessed in blood samples.

RESULTS

Our data revealed that premorbid TS promoted significantly increased inflammation and loss of BBB integrity in TBI when compared to TS-Free test mice. Additionally, mice chronically exposed to TS before TBI experienced a more significant weight loss, behavioral and motor activity deficiency, and slower post-TBI recovery when compared to TS-free TBI mice.

CONCLUSION

The effects of premorbid TS appear consequential to the abrogation of physiological antioxidative and anti-inflammatory response to TBI leading to worsening impairments of the BBB, OS damage, and inflammation. These factors are also likely responsible for the retardation of post-traumatic recovery observed in these animals.

Biomarkers of Potential Harm: Summary of an FDA-Sponsored Public Workshop

Introduction

Since 2009, the United States (US) Food and Drug Administration (FDA) Center for Tobacco Products (CTP) has had the authority to regulate the manufacture, distribution, and marketing of tobacco products in order to reduce the death and disease caused by tobacco use. Biomarkers could play an important role across a number of FDA regulatory activities, including assessing new and modified risk tobacco products and identifying and evaluating potential product standards.

Methods

On April 4-5, 2016, FDA/CTP hosted a public workshop focused on biomarkers of potential harm (BOPH) with participants from government, industry, academia, and other organizations. The workshop was divided into five sessions focused on: (1) overview of BOPH; (2) cardiovascular disease (CVD); (3) chronic obstructive pulmonary disease (COPD); (4) cancer; and (5) new areas of research.

Results and Conclusions

The deliberations from the workshop noted some promising BOPH but also highlighted the lack of systematic effort to identify BOPH that would have utility and validity for evaluating tobacco products. Research areas that could further strengthen the applicability of BOPH to tobacco regulatory science include the exploration of composite biomarkers as predictors of disease risk, "omics" biomarkers, and examining biomarkers using existing cohorts, surveys, and experimental studies.

Implications

This paper synthesizes the main findings from the 2016 FDA-sponsored workshop focused on BOPH and highlights research areas that could further strengthen the science around BOPH and their applicability to tobacco regulatory science.

Atomic force microscopy and Raman spectra profile of blood components associated with exposure to cigarette smoking

Tobacco smoke contains several compounds with oxidant and pro-oxidant properties with the capability of producing structural changes in biomolecules, as well as cell damage. This work aimed to describe and analyse the effect of tobacco smoke on human blood components, red blood cell (RBC) membrane, haemoglobin (Hb) and blood plasma by Atomic Force Microscopy (AFM) and Raman spectroscopy. Our results indicate that tobacco induced RBC membrane nano-alterations characterized by diminished RBC diameter and increased nano-vesicles formation, and RBC fragility. The Raman spectra profile suggests modifications in chemical composition specifically found in peaks 1135 cm⁻¹, 1156 cm⁻¹, 1452 cm⁻¹ and intensity relation of peaks 1195 cm⁻¹ and 1210 cm⁻¹ of blood plasma and by change of peaks 1338 cm⁻¹, 1357 cm⁻¹, 1549 cm⁻¹ and 1605 cm⁻¹ associated with the pyrrole ring of Hb. The relevance of these results lies in the identification of a profile of structural and chemical alterations that serves as a biomarker of physiological and pathological conditions in the human blood components induced by tobacco exposure using AFM and the Raman spectroscopy as tools for monitoring them.

Tobacco smoke contains several compounds with oxidant and pro-oxidant properties with the capability of producing structural changes in biomolecules, as well as cell damage.

Contribution of cathepsin B-dependent Nlrp3 inflammasome activation to nicotine-induced endothelial barrier dysfunction

Recent studies indicate that endothelial Nlrp3 inflammasome is critically involved in the development of cardiovascular complications. However, it remains unknown whether endothelial inflammasome is involved in endothelial barrier dysfunction associated with smoking. This study aims to investigate the role of endothelial Nlrp3 inflammasome in nicotine-induced disruption of inter-endothelial tight junctions and consequent endothelial barrier dysfunction. The confocal microscopic analysis demonstrated that mice treated with nicotine exhibited disrupted inter-endothelial tight junctions as shown by decreased ZO-1 and ZO-2 expression in the coronary arterial endothelium, whereas the decreases in ZO-1/2 were prevented by Nlrp3 gene deficiency. In cultured endothelial cells, nicotine caused Nlrp3 inflammasome complex formation and enhances the inflammasome activity as shown by increased cleavage of pro-caspase-1, and interleukin-1β (IL-1β) production. Further, nicotine disrupted tight junction and increased permeability in an endothelial cell monolayer, and this nicotine-induced effect was prevented by silencing of Nlrp3 gene, inhibition of caspase-1, or blockade of high mobility group box 1 (HMGB1). Nicotine increased endothelial cell lysosomal membrane permeability and triggered the lysosomal release of cathepsin B, whereas these events were prevented by pretreating cells with a lysosome stabilizing agent, dexamethasone. Collectively, our data suggest that nicotine enhances cathepsin B-dependent Nlrp3 inflammasome activation and the consequent production of a novel permeability factor HMGB1, which causes disruption of inter-endothelial tight junctions leading to endothelial hyperpermeability. Instigation of endothelial inflammasomes may serve as an important pathogenic mechanism contributing to the early onset of vasculopathy associated with smoking.

Anti-Diabetic Countermeasures Against Tobacco Smoke-Dependent Cerebrovascular Toxicity: Use and Effect of Rosiglitazone

Tobacco smoking (TS) is one of the most addictive habit sand a main public health hazards, impacting the vascular endothelium through oxidative stress (OS) stimuli, exposure to nicotine, and smoking-induced inflammation in a dose-dependent manner. Increasing evidence also suggested that TS increases glucose intolerance and the risk factor of developing type-2 diabetes mellitus (2DM), which, along with TS, is connected to blood–brain barrier (BBB) injuries, and heightens the risk of cerebrovascular disorders. Although the exact mechanism of rosiglitazone (RSG) is unknown, our previous in vitro work showed how RSG, an oral anti-diabetic drug belonging to the family of thiazolidinedione class, can protect BBB integrity through enhancement of nuclear factor erythroid 2-related factor (Nrf2) activity. Herein, we have validated the protective role of rosiglitazone against TS-induced BBB impairment in vivo. Our results revealed that RSG as a peroxisome proliferator-activated receptor gamma (PPARγ), activates counteractive mechanisms primarily associated with the upregulation of Nrf2 and PPARγ pathways which reduce TS-dependent toxicity at the cerebrovascular level. In line with these findings, our results show that RSG reduces inflammation and protects BBB integrity. In conclusion, RSG offers a novel and promising therapeutic application to reduce TS-induced cerebrovascular dysfunction through activation of the PPARγ-dependent and/or PPARγ-independent Nrf2 pathway.

[The distribution of matrix metalloproteinases and their tissue inhibitors in the brain vascular bed exposed to chronic tobacco smoke]

AIM

To study the distribution of MMP-2 and MMP-9 and their inhibitors (TIMP-2 and TIMP-1 respectively) in the brain vascular bed of rats exposed to chronic tobacco smoke.

MATERIAL AND METHODS

Localization and expression of MMP-2, MMP-9, TIMP-2 and TIMP-1 in the pial branches (I-V order vessels), intracerebral arteries and capillaries of rats exposed to tobacco smoke were studied for 36 weeks. The level of enzymatic activity was assessed by the relative quantity of enzymopositive arteries and amount of fragments per 1 mm2 and rate of immunohistochemical reaction. Specific capillary density per mm2 of brain tissue and optical density of the immunohistochemical product were calculated.

RESULTS

MMP-2 and TIMP-2 were found in all segments of the arterial course in control animals. In rats exposed to tobacco smoking, the expression of MMP-2 increased only in intracerebral arteries and capillaries while TIMP-2 level decreased. MMP-9 and TIMP-1 were noted only in single vessels, mainly small pial and intracerebral arteries, in intact animals. In rats exposed to tobacco smoke, MMP-9 expression significantly increased in all segments of the arterial course whereas the increase in TIMP-1 was observed mainly in large pial arteries.

CONCLUSION

In physiological conditions, the dynamic balance between MMP-2 and TIMP-2 maintains basic tissue metabolism. Products of tobacco combustion are inductors of the inducible MMP-9 which promotes morphofunctional changes. The imbalance in MMP-9 - TIMP-1 system causes the degradation of extracellular matrix in different segments of the brain arterial course promoting the development of cerebral dysfunction.

Impact of Tobacco Smoke in HIV Progression: a Major Risk Factor for the Development of NeuroAIDS and Associated of CNS Disorders

Aim

With the advent of highly active and combination antiretroviral therapy have substantially increased the life expectancy of patients infected with human immunodeficiency virus (HIV). However, this has brought into sharp contrast the incidence of several 'Non-acquired immunodeficiency syndrome (AIDS) diseases such as NeuroAIDS which identifies a group of neurological disorders caused primarily by HIV-mediated damage to the central and peripheral nervous systems. Given the patients depleted immune condition, the use and abuse of drug and addictive substances such as tobacco smoking can further deteriorates their overall health and accelerate the progression and severity of the disease. In this review we detail the pathogenesis, progression and characteristics of HIV and the impact of tobacco smoking as a risk factor for the progression of the disease to NeuroAIDS. This is a poorly understood aspect of HIV-related complications that needs to be addressed.

Subjects and methods

Review of theoretical approaches and knowledge synthesis.

Results

Tobacco smoking is highly prevalent in HIV patients when compared to the general population. The oxidative damage and inflammatory stress caused by chronic smoking on the cerebrovascular system have been well established. Considering that HIV patients have an impaired immune system and smokers per se are more susceptible to viral and bacterial inflammatory neuropathologies than non-smokers, it is conceivable that tobacco smoking as a risk factor for the progression of HIV into NeuroAIDS and related neurological impairments.

Conclusion

Tobacco smoke (TS) may bring about a synergistic effect in the context of persistent inflammatory state and cerebrovascular damage which facilitate HIV infection and progression to NeuroAIDS when compared to non-smokers.

Cigarette Smoke Induces Intestinal Inflammation via a Th17 Cell-Neutrophil Axis

Epidemiological evidence finds cigarette smoking is a common risk factor for a number of diseases, not only in the lung but also in other tissues, such as the gastrointestinal tract. While it is well-documented that smoking directly drives lung inflammatory disease, how it promotes disease in peripheral tissues is incompletely understood. In this study, we utilized a mouse model of short-term smoke exposure and found increased Th17 cells and neutrophilia in the lung as well as in the circulation. Following intestinal inflammatory challenge, smoke exposed mice showed increased pathology which corresponds to enhanced intestinal Th17 cells, ILC3 and neutrophils within intestinal tissue. Using cellular depletion and genetic deficiencies, we define a cellular loop by which IL-17A and downstream neutrophils drive cigarette smoke-enhanced intestinal inflammation. Collectively, cigarette smoke induced local lung Th17 responses lead to increased systemic susceptibility to inflammatory insult through enhanced circulating neutrophils. These data demonstrate a cellular pathway by which inflammatory challenge in the lung can sensitize the intestine to enhanced pathological innate and adaptive immune responses.

A, Ravishankar, Reddy DC, Dhiman RK. Prevalence of Minimal Hepatic Encephalopathy in Patients With Liver Cirrhosis: A Cross-Sectional, Clinicoepidemiological, Multicenter, Nationwide Study in India: The PREDICT Study

BACKGROUND

The study aimed at assessing the prevalence and clinical profile of minimal hepatic encephalopathy (MHE) in patients with cirrhosis using neuropsychological assessment and at understanding the management practices of MHE in the Indian clinical setting.

METHODS

This cross-sectional, clinicoepidemiological study conducted at 20 sites enrolled liver cirrhosis patients with Grade 0 hepatic encephalopathy according to West-Haven Criteria. Patients were subjected to mini-mental state examination and those with a score of ≥24 were assessed using psychometric hepatic encephalopathy score. Short Form-36 questionnaire was administered to assess the impact on health-related quality of life.

RESULTS

Of the 1260 enrolled patients, 1114 were included in the analysis. The mean age was 49.5 years and majority were males (901 [81%]). The prevalence of MHE was found to be 59.7% (665/1114) based on the psychometric hepatic encephalopathy score of ≤-5. Alcohol-related liver disease was the most common etiology (482 [43.27%]) followed by viral infection (239 [21.45%]). Past smokers as well as those currently smoking were more likely to have MHE than nonsmokers. A significant association was found between tobacco chewing, smoking, alcohol consumption, diabetes, and the presence of MHE. Multivariable analysis revealed smoking as the only parameter associated with MHE. A total of 300 (26.9%) patients were on prophylaxis with lactulose/lactitol or rifaximin. These patients were less likely to have MHE as compared to those not on prophylaxis (odds ratio, 0.67; 95% confidence interval, 0.50-0.88; P = 0.005).

CONCLUSION

The disease burden of MHE is quite substantial in patients with cirrhosis with no apparent cognitive defect. Smoking, whether past or current, has significant association with the presence of MHE. Although MHE has been shown to adversely affect quality of life, prophylaxis for MHE is not routinely practiced in the Indian setting.The study has been registered under clinical trials registry of India (CTRI/2014/01/004306).

Potential neuroprotective role of astroglial exosomes against smoking-induced oxidative stress and HIV-1 replication in the central nervous system

INTRODUCTION

HIV-1-infected smokers are at risk of oxidative damage to neuronal cells in the central nervous system by both HIV-1 and cigarette smoke. Since neurons have a weak antioxidant defense system, they mostly depend on glial cells, particularly astrocytes, for protection against oxidative damage and neurotoxicity. Astrocytes augment the neuronal antioxidant system by supplying cysteine-containing products for glutathione synthesis, antioxidant enzymes such as SOD and catalase, glucose for antioxidant regeneration via the pentose-phosphate pathway, and by recycling of ascorbic acid. Areas covered: The transport of antioxidants and energy substrates from astrocytes to neurons could possibly occur via extracellular nanovesicles called exosomes. This review highlights the neuroprotective potential of exosomes derived from astrocytes against smoking-induced oxidative stress, HIV-1 replication, and subsequent neurotoxicity observed in HIV-1-positive smokers. Expert opinion: During stress conditions, the antioxidants released from astrocytes either via extracellular fluid or exosomes to neurons may not be sufficient to provide neuroprotection. Therefore, we put forward a novel strategy to combat oxidative stress in the central nervous system, using synthetically developed exosomes loaded with antioxidants such as glutathione and the anti-aging protein Klotho.

The effect of electronic-cigarettes aerosol on rat brain lipid profile

The electronic cigarettes (e-cigarettes, e-cigs) have become the most sought-after alternative to the traditional cigarettes, partly due to the widespread perception of safety. However, the high temperature reached by e-cig solutions can generate toxic compounds, some of which are listed as known human carcinogens. To evaluate the impact of e-cig aerosol on rat brain lipid profile, twenty male Sprague Dawley rats were exposed to 11 cycles/day (E-cig group), to consume 1 mL/day of e-liquid, for 5 days/week up to 8 weeks. Ten rats were sacrificed after 4 weeks (4w) and ten at the end of treatment (8w). The composition of total fatty acids, sterols and oxysterols of the lipid fraction of rat brains, was analyzed. The results of the E-cig group were compared with those of the control group (not exposed). After 8 weeks, the saturated fatty acids significantly raised up to 7.35 mg/g tissue, whereas polyunsaturated fatty acids decreased reaching 3.17 mg/g. The e-cig vaping increased both palmitic (3.43 mg/g) and stearic acids (3.82 mg/g), while a significant decrement of arachidonic (1.32 mg/g) and docosahexaenoic acids (1.00 mg/g) was found. Atherogenic (0.5) and thrombogenic (1.12) indices also increased in 8w treated animals. The e-cig aerosol significantly impacted the cholesterol homeostasis, since the latter at 8w (21.57 mg/g) was significantly lower than control (24.56 mg/g); moreover, a significant increase of 7-dehydrocholesterol (1.87 mg/g) was also denoted in e-cig group. The e-cig aerosol also reduced the oxysterol formation (19.55 μg/g) after 4 weeks of exposure, except for triol and 5α,6α-epoxycholesterol (α-EC). The principal component analysis (PCA) separated all E-cig from control groups, evidencing that oxysterols (except triol and 24(S)-hydroxycholesterol (24(S)-HC)) were inversely correlated to 7-DHC and TI. The present research revealed that e-cigs aerosol affected the lipid and cholesterol homeostasis in rat brain, which could contribute to the new occurrence of some neurodegenerative diseases.

Immune-regulating effects of exercise on cigarette smoke-induced inflammation

Long-term cigarette smoking (LTCS) represents an important risk factor for cardiac infarction and stroke and the central risk factor for the development of a bronchial carcinoma, smoking-associated interstitial lung fibrosis, and chronic obstructive pulmonary disease. The pathophysiologic development of these diseases is suggested to be promoted by chronic and progressive inflammation. Cigarette smoking induces repetitive inflammatory insults followed by a chronic and progressive activation of the immune system. In the pulmonary system of cigarette smokers, oxidative stress, cellular damage, and a chronic activation of pattern recognition receptors are described which are followed by the translocation of the NF-kB, the release of pro-inflammatory cytokines, chemokines, matrix metalloproteases, and damage-associated molecular patterns. In parallel, smoke pollutants cross directly through the alveolus-capillary interface and spread through the systemic bloodstream targeting different organs. Consequently, LTCS induces a systemic low-grade inflammation and increased oxidative stress in the vascular system. In blood, these processes promote an increased coagulation and endothelial dysfunction. In muscle tissue, inflammatory processes activate catabolic signaling pathways followed by muscle wasting and sarcopenia. In brain, several characteristics of neuroinflammation were described. Regular exercise training has been shown to be an effective nonpharmacological treatment strategy in smoke-induced pulmonary diseases. It is well established that exercise training exerts immune-regulating effects by activating anti-inflammatory signaling pathways. In this regard, the release of myokines from contracting skeletal muscle, the elevations of cortisol and adrenalin, the reduced expression of Toll-like receptors, and the increased mobilization of immune-regulating leukocyte subtypes might be of vital importance. Exercise training also increases the local and systemic antioxidative capacity and several compensatory mechanisms in tissues such as an increased anabolic signaling in muscle or an increased compliance of the vascular system. Accordingly, regular exercise training seems to protect long-term smokers against some important negative local and systemic consequences of smoking. Data suggest that it seems to be important to start exercise training as early as possible.

Cigarette Smoke Initiates Oxidative Stress-Induced Cellular Phenotypic Modulation Leading to Cerebral Aneurysm Pathogenesis

OBJECTIVE

Cigarette smoke exposure (CSE) is a risk factor for cerebral aneurysm (CA) formation, but the molecular mechanisms are unclear. Although CSE is known to contribute to excess reactive oxygen species generation, the role of oxidative stress on vascular smooth muscle cell (VSMC) phenotypic modulation and pathogenesis of CAs is unknown. The goal of this study was to investigate whether CSE activates a NOX (NADPH oxidase)-dependent pathway leading to VSMC phenotypic modulation and CA formation and rupture.

APPROACH AND RESULTS

In cultured cerebral VSMCs, CSE increased expression of NOX1 and reactive oxygen species which preceded upregulation of proinflammatory/matrix remodeling genes (MCP-1, MMPs [matrix metalloproteinase], TNF-α, IL-1β, NF-κB, KLF4 [Kruppel-like factor 4]) and downregulation of contractile genes (SM-α-actin [smooth muscle α actin], SM-22α [smooth muscle 22α], SM-MHC [smooth muscle myosin heavy chain]) and myocardin. Inhibition of reactive oxygen species production and knockdown of NOX1 with siRNA or antisense decreased CSE-induced upregulation of NOX1 and inflammatory genes and downregulation of VSMC contractile genes and myocardin. p47phox^-/- NOX knockout mice, or pretreatment with the NOX inhibitor, apocynin, significantly decreased CA formation and rupture compared with controls. NOX1 protein and mRNA expression were similar in p47phox^-/- mice and those pretreated with apocynin but were elevated in unruptured and ruptured CAs. CSE increased CA formation and rupture, which was diminished with apocynin pretreatment. Similarly, NOX1 protein and mRNA and reactive oxygen species were elevated by CSE, and in unruptured and ruptured CAs.

CONCLUSIONS

CSE initiates oxidative stress-induced phenotypic modulation of VSMCs and CA formation and rupture. These molecular changes implicate oxidative stress in the pathogenesis of CAs and may provide a potential target for future therapeutic strategies.

The blood-brain barrier in psychosis

Blood-brain barrier pathology is recognised as a central factor in the development of many neurological disorders, but much less is known about the role of the blood-brain barrier in psychiatric disorders. We review post-mortem, serum-biomarker, CSF-biomarker, and neuroimaging studies that have examined blood-brain barrier structure and function in schizophrenia and related psychoses. We consider how blood-brain barrier dysfunction could relate to glutamatergic and inflammatory abnormalities, which are increasingly understood to play a part in the pathogenesis of psychosis. Mechanisms by which the blood-brain barrier and its associated solute transporters moderate CNS availability of antipsychotic drugs are summarised. We conclude that the complex nature of blood-brain barrier dysfunction in psychosis might be relevant to many aspects of disrupted neuronal and synaptic function, increased permeability to inflammatory molecules, disrupted glutamate homoeostasis, impaired action of antipsychotics, and development of antipsychotic resistance. Future research should address the longitudinal course of blood-brain barrier alterations in psychosis, to determine whether blood-brain barrier dysfunction is a cause or consequence of the pathology associated with the disorder.

ROS-AKT-mTOR axis mediates autophagy of human umbilical vein endothelial cells induced by cooking oil fumes-derived fine particulate matters in vitro

Cooking oil fumes-derived PM_2.5 (COFs-derived PM_2.5) exposure can induce oxidative stress and cytotoxic effects. Here we investigated the role of ROS-AKT-mTOR axis in COFs-derived PM_2.5-induced autophagy in human umbilical vein endothelial cells (HUVECs). HUVECs were treated with different concentrations of COFs-derived PM_2.5, together with or without N-acetyl-L-cysteine (NAC, a radical scavenger) or 3-methyladenine (3-MA, an autophagy inhibitor). Cell viability was assessed with MTT assay, and ROS level was measured with DCFH-DA assay after the treatment. Transmission electron microscopy (TEM) was used to evaluate the formation of autophagosomes, while immunofluorescent assay and western blot were used to assess the expression of LC3-I/II and beclin 1. Proteins involved in the PI3K-AKT-mTOR signaling pathway were measured with western blot. The results showed that the treatment of COFs-derived PM_2.5 dose-dependently reduced the viability of HUVECs and increased the ROS levels in the cells. Both immunofluorescent assay and western blot showed that treatment with COFs-derived PM_2.5 significantly increased LC3-II and beclin 1 levels, as well as the ratio of LC3-II/LC3-I, which could be rescued by the co-incubation with NAC or 3-MA. TEM also confirmed the increased formation of autophagosomes in the cells treated with COFs-derived PM_2.5, while co-treatment with NAC evidently decreased autophagosomes formation. In addition, western blot also showed that the phosphorylation of PI3K, AKT, and mTOR all decreased by the treatment of COFs-derived PM_2.5, which was effectively rescued by the co-treatment with NAC. These findings demonstrate ROS-AKT-mTOR axis plays a critical role in HUVECs autophagy induced by COFs-derived PM_2.5.

Cigarette Smoking Triggers Colitis by IFN-γ+ CD4+ T Cells

The increased incidence of Crohn’s disease in smokers has been recently reported, suggesting a strong association of cigarette smoke (CS) with colitis. However, the mechanism of the action of CS on colitis has not yet been explored. Here, we demonstrate that CS exposure is sufficient to induce colitis in mice. Interestingly, the colitis is mainly mediated by Th1, but not Th17, responses. CD4⁺ T-cell depletion or T-bet/IFN-γ deficiency protects against the development of colitis induced by CS. Additionally, IFN-γ-producing CD4⁺ T cells play a substantial role in CS-induced colitis. The adoptive transfer (AT) of effector T cells from CS-exposed WT mice into colitis-prone mice caused these mice to develop colitis, while the AT of effector T cells from IFN-γ knock-out mice did not. These findings have implications for broadening our understanding of CS-induced pathology and for the development of novel therapeutic strategies to treat Crohn’s disease.

Monocyte count at onset predicts poststroke outcomes during a 90-day follow-up

BACKGROUND

Acute ischaemic stroke (AIS) triggers both systemic and neurovascular inflammation, influencing poststroke recovery. In smokers with AIS, inflammation might be further upregulated, increasing ischaemia/reperfusion injury. Here, the predictive value of leucocyte and adhesion molecules levels on poststroke outcomes was investigated.

MATERIALS AND METHODS

A total of 89 patients with AIS (n = 30 smokers and n = 59 nonsmokers) were recruited and evaluated 1, 7 and 90 days after the onset to assess stroke severity by the National Institute of Health Stroke Scale (NIHSS) score as well as clinical recovery at 90 days by the modified Rankin Scale (mRS). Lesion volume was assessed by noncontrast computed tomography. Haematological parameters, blood chemistry and soluble adhesion molecules were measured.

RESULTS

Smokers experienced a more severe stroke and at a younger age with respect to nonsmokers, moreover, they had higher circulating levels of monocytes, neutrophils and soluble adhesion molecules. Baseline monocytes positively correlated with stroke severity and disability across all time points in the overall cohort. No correlation was shown between adhesion molecules and poststroke outcomes. A monocyte count >0·63 × 10⁹ /L predicted worse stroke severity (defined as NIHSS ≥5) at day 90 independently of age, hypertension, thrombolysis and active smoking in the overall cohort. Similarly, a monocyte count >0·64 × 10⁹ /L predicted poor neurological recovery at day 90 (defined as mRS > 2).

CONCLUSIONS

Smoker had more severe AIS and higher leucocytes and adhesion molecule levels. In the overall cohort, monocyte count was an independent predictor of worse poststroke outcome. Although larger trials are needed, monocyte count might be a cheap prognostic parameter in AIS.

Genome-wide imaging association study implicates functional activity and glial homeostasis of the caudate in smoking addiction

Background

Nearly 6 million deaths and over a half trillion dollars in healthcare costs worldwide are attributed to tobacco smoking each year. Extensive research efforts have been pursued to elucidate the molecular underpinnings of smoking addiction and facilitate cessation. In this study, we genotyped and obtained both resting state and task-based functional magnetic resonance imaging from 64 non-smokers and 42 smokers. Smokers were imaged after having smoked normally (“sated”) and after having not smoked for at least 12 h (“abstinent”).

Results

While abstinent smokers did not differ from non-smokers with respect to pairwise resting state functional connectivities (RSFCs) between 12 brain regions of interest, RSFCs involving the caudate and putamen of sated smokers significantly differed from those of non-smokers (P < 0.01). Further analyses of caudate and putamen activity during elicited experiences of reward and disappointment show that caudate activity during reward (CR) correlated with smoking status (P = 0.015). Moreover, abstinent smokers with lower CR experienced greater withdrawal symptoms (P = 0.024), which suggests CR may be related to smoking urges. Associations between genetic variants and CR, adjusted for smoking status, were identified by genome-wide association study (GWAS). Genes containing or exhibiting caudate-specific expression regulation by these variants were enriched within Gene Ontology terms that describe cytoskeleton functions, synaptic organization, and injury response (P < 0.001, FDR < 0.05).

Conclusions

By integrating genomic and imaging data, novel insights into potential mechanisms of caudate activation and homeostasis are revealed that may guide new directions of research toward improving our understanding of addiction pathology.

Electronic supplementary material

The online version of this article (10.1186/s12864-017-4124-5) contains supplementary material, which is available to authorized users.

Impact of commercial cigarette smoke condensate on brain tissue co-cultured with astrocytes and blood-brain barrier endothelial cells

The purpose of the current study was to investigate the effect of two commercial cigarette smoke condensates (CCSC) on oxidative stress and cell cytotoxicity in human brain (T98G) or astrocytes (U-373 MG) in the presence of human brain microvascular endothelial cells (HBMEC). Cell viability of mono-culture of T98G or U-373 MG was markedly decreased in a concentration-dependent manner, and T98G was more susceptible than U-373 MG to CCSC exposure. Cytotoxicity was less prominent when T98G was co-cultured with HBMEC than when T98G was co-cultured with U-373 MG. Significant reduction in trans-epithelial electric resistance (TEER), a biomarker of cellular integrity was noted in HBMEC co-cultured with T98G (HBMEC-T98G co-culture) and U-373 MG co-cultured with T98G (U-373 MG-T98G co-culture) after 24 or 48 hr CCSC exposure, respectively. TEER value of U-373 MG co-cultured with T98G (79-84%) was higher than HBMEC co-cultured with T98G (62-63%) within 120-hr incubation with CCSC. Reactive oxygen species (ROS) generated by CCSC in mono-culture of T98G and U-373 MG reached highest levels at 4 and 16 mg/ml, respectively. ROS production by T98G fell when co-cultured with HBMEC or U-373MG. These findings suggest that adverse consequences of CCSC treatment on brain cells may be protected by blood-brain barrier or astrocytes, but with chronic exposure toxicity may be worsened due to destruction of cellular integrity.

Cigarette smoking is associated with amplified age-related volume loss in subcortical brain regions

BACKGROUND

Magnetic resonance imaging studies of cigarette smoking-related effects on human brain structure have primarily employed voxel-based morphometry, and the most consistently reported finding was smaller volumes or lower density in anterior frontal regions and the insula. Much less is known about the effects of smoking on subcortical regions. We compared smokers and non-smokers on regional subcortical volumes, and predicted that smokers demonstrate greater age-related volume loss across subcortical regions than non-smokers.

METHODS

Non-smokers (n=43) and smokers (n=40), 22-70 years of age, completed a 4T MRI study. Bilateral total subcortical lobar white matter (WM) and subcortical nuclei volumes were quantitated via FreeSurfer. In smokers, associations between smoking severity measures and subcortical volumes were examined.

RESULTS

Smokers demonstrated greater age-related volume loss than non-smokers in the bilateral subcortical lobar WM, thalamus, and cerebellar cortex, as well as in the corpus callosum and subdivisions. In smokers, higher pack-years were associated with smaller volumes of the bilateral amygdala, nucleus accumbens, total corpus callosum and subcortical WM.

CONCLUSIONS

Results provide novel evidence that chronic smoking in adults is associated with accelerated age-related volume loss in subcortical WM and GM nuclei. Greater cigarette quantity/exposure was related to smaller volumes in regions that also showed greater age-related volume loss in smokers. Findings suggest smoking adversely affected the structural integrity of subcortical brain regions with increasing age and exposure. The greater age-related volume loss in smokers may have implications for cortical-subcortical structural and/or functional connectivity, and response to available smoking cessation interventions.

Factors Associated with Occurrence of Radiation-induced Optic Neuropathy at "Safe" Radiation Dosage

BACKGROUND

Radiation-induced optic neuropathy (RION) is a rare, and often visually devastating, complication of radiation therapy (RT) near the anterior visual pathways.

METHODS

A retrospective case series of patients who developed RION at a tertiary medical center, followed by a case-control study comparing RION cases with matched controls who received RT.

RESULTS

Thirteen patients (18 eyes) with RION were identified. Radiation modalities included external beam photon radiation, whole brain radiation, stereotactic radiosurgery, proton beam, and unknown. Most patients received doses below published "safe" thresholds (<55 Gy; <8-10 Gy for stereotactic radiosurgery). There was no statistically significant difference in prevalence of vasculopathic factors between cases and controls; on subgroup analysis in three patients who received surprisingly low radiation doses, smoking (p=0.05) and hypertension (p=0.02) appeared more prevalent.

CONCLUSION

RION can occur at doses below published "safe" thresholds and with different RT modalities. Smoking and hypertension might be risk factors for RION.

Topographies of Cortical and Subcortical Volume Loss in HIV and Aging in the cART Era

OBJECTIVES

Studies of HIV-associated brain atrophy often focus on a priori brain regions of interest, which can introduce bias. A data-driven, minimally biased approach was used to analyze changes in brain volumetrics associated with HIV and their relationship to aging, viral factors, combination antiretroviral therapy (cART), and gender, and smoking.

DESIGN

A cross-sectional study of 51 HIV-uninfected (HIV-) and 146 HIV-infected (HIV+) participants.

METHODS

Structural MRI of participants was analyzed using principal component analysis (PCA) to reduce dimensionality and determine topographies of volumetric changes. Neuropsychological (NP) assessment was examined using global and domain-specific scores. The effects of HIV disease factors (eg, viral load, CD4, etc.) on brain volumes and neuropsychological were investigated using penalized regression (LASSO).

RESULTS

Two components of interest were visualized using principal component analysis. An aging effect predominated for both components. The first component, a cortically weighted topography, accounted for a majority of variance across participants (43.5% of variance) and showed independent effects of HIV and smoking. A secondary, subcortically weighted topography (4.6%) showed HIV-status accentuated age-related volume loss. In HIV+ patients, the cortical topography correlated with global neuropsychological scores and nadir CD4, whereas subcortical volume loss was associated with recent viral load.

CONCLUSIONS

Cortical regions showed the most prominent volumetric changes because of aging and HIV. Within HIV+ participants, cortical volumes were associated with immune history, whereas subcortical changes correlated with current immune function. Cognitive function was primarily associated with cortical volume changes. Observed volumetric changes in chronic HIV+ patients may reflect both past infection history and current viral status.

The effect of tobacco smoke exposure on the generation of reactive oxygen species and cellular membrane damage using co-culture model of blood brain barrier with astrocytes

Brain tissue is known to be vulnerable to the exposure by tobacco smoke. Tobacco smoke can induce generation of reactive oxygen species (ROS), causing inflammatory activity and blood-brain barrier (BBB) impairment. The aim of the present study was to investigate the effect of tobacco smoke on cell cytotoxicity, generation of ROS, and cellular membrane damage in astrocytes and BBB using a co-culture system. Cell viability of U373MG cells was reduced in a dose-dependent manner, ranging from 96.7% to 40.3% by tobacco smoke condensate (TSC). Cell viability of U373MG co-cultured with human brain microvascular endothelial cells (HBMECs) was 104.9% at the IC50 value of TSC. Trans-epithelial electric resistance values drastically decreased 80% following 12-h incubation. The value was maintained until 48 h and then increased at 72-h incubation (85%). It then decreased to 75% at 120 h. Generation of ROS increased in a dose-dependent manner, ranging from 102.7% to 107.9%, when various concentrations of TSC (4-16 mg/mL) were administered to the U373MG monoculture. When TSC was added into U373MG co-cultured with HBMECs, production of ROS ranged from 101.7% to 102.6%, slightly increasing over 12 h. Maximum exposure-generated ROS of 104.8% was reached at 24 h. Cell cytotoxicity and oxidative stress levels in the U373MG co-culture model system with HBMECs were lower than U373MG monoculture. HBMECs effectively acted as a barrier to protect the astrocytes (U373MG) from toxicity of TSC.

[Effects of chronic tabacco smoking on the cerebral blood flow]

AIM

To study an effect of chronic smoking on cerebral hemodynamics and cerebrovascular reactivity in different segments of the arterial system of the brain in men.

MATERIAL AND METHODS

Male patients enrolled in the study were divided into two groups: controls (n=11) and smokers (n=24) with index 30.7 pack-year smoking history. Haemorheological parameters: viscosity of blood, aggregation of erythrocytes, hematocrit, fibrinogen were evaluated in both groups. Using carotid duplex ultrasound (MyLab 50 Esaote, Italy), intima-media thickness (IMT) of common carotid arteries (CCA) was measured. Parameters of cerebral hemodynamics were evaluated using transcranial Doppler ultrasound (Nicolet Companion Biomedikal, USA). Tests of the cerebrovascular reactivity were used to study arteries of three levels: common carotid arteries, middle cerebral arteries (MCA) and pial arteries.

RESULTS

An increase in erythrocytes, hemoglobin, hematocrit, viscosity of blood, aggregation of erythrocytes and fibrinogen was found in the group of smokers compared to the control group. There were an increase in IMT of CCA by more than 50% and a decrease in the mean flow velocity in CCA in smokers. Also smoking decreased MCA mean flow velocity, but this decrease was 2-3 times smaller than in the common carotid arteries. Vasoconstrictor reactions prevailed in MCA, as indicated by the increase in the peripheral vascular resistance index. An increase in vasospastic reactions in pial arteries in smokers was discovered. At the same time, the vasodilatation reaction was maintained or not significantly reduced in pial arteries.

CONCLUSION

Chronic smoking is one of the significant factors causing changes in haemorheological parameters, damage of vascular wall, initiation of atherogenesis and disturbance of cerebral hemodynamics. The study of velocity characteristics and peripheral vascular resistance indices in the group of smokers revealed different reactions of different segments of the brain arterial system.

Comparison of color discrimination in chronic heavy smokers and healthy subjects

Background: Cigarette smoke is probably the most significant source of exposure to toxic chemicals for humans, involving health-damaging components, such as nicotine, hydrogen cyanide and formaldehyde. The aim of the present study was to assess the influence of chronic heavy smoking on color discrimination (CD). Methods: All subjects were free of any neuropsychiatric disorder, identifiable ocular disease and had normal acuity. No abnormalities were detected in the fundoscopic examination and in the optical coherence tomography exam. We assessed color vision for healthy heavy smokers ( n = 15; age range, 20-45 years), deprived smokers ( n = 15, age range 20-45 years) and healthy non-smokers ( n = 15; age range, 20-45 years), using the psychophysical forced-choice method. All groups were matched for gender and education level. In this test, the volunteers had to choose the pseudoisochromatic stimulus containing a test frequency at four directions (e.g., up, down, right and left) in the subtest of Cambridge Colour Test (CCT): Trivector. Results: Performance on CCT differed between groups, and the observed pattern was that smokers had lower discrimination compared to non-smokers. In addition, deprived smokers presented lower discrimination to smokers and non-smokers. Contrary to expectation, the largest differences were observed for medium and long wavelengths. Conclusions: These results suggests that cigarette smoking, chronic exposure to its compounds, and withdrawal from nicotine affect color discrimination. This highlights the importance of understanding the diverse effects of nicotine on attentional bias.

Probing cigarette smoke-induced DNA single-strand breaks and screening natural protective compounds by use of magnetic bead-based chemiluminescence

Magnetic bead (MB)-based chemiluminescence (CL) ELISA can be a sample-thrifty, time-saving tool for evaluation of cigarette smoke-induced DNA single-strand breaks (SSBs) with high specificity. This article describes a novel approach using immobilized oligonucleotide on MBs to determine cigarette smoke-induced DNA SSBs and screen some protective natural compounds. Typically, fluorescein-labeled DNA (FAM-DNA) was immobilized on the MBs and then oxidized by the smoke in the absence or presence of natural compounds, and a part of FAM-DNA was fragmented due to cigarette smoke-induced DNA SSB and then detached from MBs whereas other non-broken FAM-DNA still remained on MBs. Then, any broken FAM-DNA fragments, complex tobacco smoke matrix, and other stuff related with natural compounds were conveniently washed away by a magnetic force, and thus possible interfering substances were completely removed. Finally, those remaining non-broken FAM-DNA on MBs were reacted with HRP-labeled anti-fluorescein antibody and then detected by CL ELISA. CL signal was converted to molar concentrations of the FAM-DNA by interpolation from a pre-determined standard linear calibration curve. The level of DNA SSBs induced by cigarette smoke was thus calculated using the method. A library of 30 natural products was subsequently screened, and two among them were found to protect DNA from oxidative damage and thus may be promising compounds for the development of new drugs. The method developed will be useful for quantitative screening of drug genotoxicity in terms of induction of DNA SSBs. Graphical abstract ᅟ.

Cerebral oxygenation and sympathetic responses to smoking in young and middle-aged smokers

This study examined the effects of acute tobacco smoking on cerebral oxygenation and autonomic function in 28 male, habitual smokers of shorter young smokers (YSM) or longer middle-aged smokers (MSM) smoking history. Following baseline testing, participants undertook a smoking protocol involving the consumption of two cigarettes within 15 min. Measures of cerebral oxygenation and autonomic function were collected before, during, and 0 min, 30 min, 1 h, and 4 h post-smoking. Tissue saturation index (TSI) for MSM was greater than YSM during cigarette consumption ( p < 0.05). Moreover, MSM observed significant within-group changes for TSI during and post-cigarette consumption ( p < 0.05). Further, MSM observed an increase in low frequency (LF) band from 30 min to 1 h post-consumption, followed by a decline, whereas elevations above MSM were observed in YSM at 4 h ( p < 0.05). Both MSM and YSM showed a decrease in high-frequency (HF) band post-cigarette, while increased LF/HF ratio post-consumption was observed in YSM. A decline in the standard deviation of RR intervals, post-cigarette consumption was evident in MSM ( p < 0.05). Moreover, the root mean square of RR interval in both groups similarly decreased following cigarette consumption ( p < 0.05). Acute smoking affects heart rate variability, suggestive of vagal withdrawal, and maybe indicate an effect of smoking history. Additionally, prolonged smoking history alters cerebral microcirculatory responses to acute tobacco exposure in MSM.

Cigarette smoking and risk of adult glioma: a meta-analysis of 24 observational studies involving more than 2.3 million individuals

Background

Cigarette smoking has been shown to be a risk factor for adult glioma by some but not all studies. We conducted a meta-analysis to systematically assess the potential association.

Methods

PubMed and EMBASE were searched from the date of their inception to October 1, 2015, to identify relevant articles. Reference lists from these articles were reviewed to identify additional studies. Both cohort and case–control studies were included. Fixed-effects models were used to calculate the overall relative risk (RR) with corresponding 95% confidence intervals (CIs).

Results

The final analysis included 24 studies (seven cohort and 17 case–control studies), involving more than 2.3 million individuals. The combined RR was 1.04 (95% CI: 1.00, 1.09; P=0.073) for ever-smokers, 0.97 (95% CI: 0.88, 1.07; P=0.574) for current-smokers, and 1.07 (95% CI: 0.98, 1.16; P=0.130) for past smokers, with little evidence of heterogeneity. Omission of any single study from the analysis had little effect on the result. No evidence of publication bias was found. A small but statistically significant increase was found in past smokers in females (RR: 1.13, 95% CI: 1.00, 1.28; P=0.046) but not in males.

Conclusion

In general, there was no association between cigarette smoking and adult glioma. The small but statistically significant association in females requires further investigation.

From the Cover: Thirdhand Cigarette Smoke Causes Stress-Induced Mitochondrial Hyperfusion and Alters the Transcriptional Profile of Stem Cells

Thirdhand cigarette smoke (THS) was recently recognized as an environmental health hazard; however, little is known about it effects on cells. Mitochondria are sensitive monitors of cell health and report on environmentally induced stress. We tested the effects of low levels of THS extracted from terry cloth on mitochondrial morphology and function using stem cells with well-defined mitochondria. Concentrations of THS that did not kill cells caused stress-induced mitochondrial hyperfusion (SIMH), which was characterized by changes in mitochondrial morphology indicative of fusion, increased mitochondrial membrane potential (MMP), increased ATP levels, increased superoxide production, and increased oxidation of mitochondrial proteins. SIMH was accompanied by a decrease in Fis1 expression, a gene responsible for mitochondrial fission, and a decrease in apoptosis-related genes, including Aifm2, Bbc3, and Bid There was also down regulation of Ucp2, Ucp4, and Ucp5, genes that decrease MMP thereby reducing oxidative phosphorylation, while promoting glycolysis. These effects, which collectively accompany SIMH, are a prosurvival mechanism to rescue damaged mitochondria and protect cells from apoptosis. Prolonged exposure to THS caused a reduction in MMP and decreased cell proliferation, which likely leads to apoptosis.

Neuroprotection against vascular dementia after acupuncture combined with donepezil hydrochloride: P300 event related potential

Acupuncture can be used to treat various nervous system diseases. Here, 168 vascular dementia patients were orally administered donepezil hydrochloride alone (5 mg/day, once a day for 56 days), or combined with acupuncture at Shenting (DU24), Tianzhu (BL10), Sishencong (Extra), Yintang (Extra), Renzhong (DU26), Neiguan (PC6), Shenmen (HT7), Fengchi (GB20), Wangu (GB12) and Baihui (DU20) (once a day for 56 days). Compared with donepezil hydrochloride alone, P300 event related potential latency was shorter with an increased amplitude in patients treated with donepezil hydrochloride and acupuncture. Mini-Mental State Examination score was also higher. Moreover, these differences in P300 latency were identified within different infarcted regions in patients treated with donepezil hydrochloride and acupuncture. These findings indicate that acupuncture combined with donepezil hydrochloride noticeably improves cognitive function in patients with vascular dementia, and exerts neuroprotective effects against vascular dementia.

Electroacupuncture Therapy in Nicotine Dependence: A Double Blind, Sham-Controlled Study

INTRODUCTION

The number of non-pharmacological controlled studies is insufficient in the treatment of nicotine dependence (ND). Nevertheless, non-pharmacological treatments, such as electroacupuncture (EA), are becoming increasingly popular in the treatment of ND. The aims of this study were to determine the efficacy and safety of "true EA therapy" (TEAT) compared to those of "sham EA therapy" (SEAT) in ND treatment.

METHODS

Eligible patients who met the DSM-IV criteria for ND (n=450) were included in the study. This study was a double-blinded, sham-controlled clinical trial with a 4-week treatment period and 4-week follow-up conducted between June and December 2009 at a psychiatry outpatient clinic. One hundred and sixty four adult (≥18 years; 44 men, 120 women) cigarette smokers out of 450 patients who met the inclusion and exclusion criteria were enrolled in the study in a ratio of 1:1 to receive TEAT (n=84) or SEAT (n=80). Routine biochemical and hematological tests, chest X-Ray, and ECG were carried out; end-expired carbon monoxide (CO) levels were measured too. Clinical characteristics were obtained through the Fagerström Nicotine Dependence Test (FNDT), Hamilton Rating Scale for Depression (HRSD), and Hamilton Anxiety Scale (HAS). EA was carried out by a trademark device, Antismoke 3000®. Efficacy analyses were performed on "intent-to-treat analysis." Primary outcome was the differences from baseline to endpoint in mean FNDT, number of cigarettes smoked per day, and CO levels at week 4. Secondary outcomes were the same variables at week 8. These variables were assessed via analysis of covariance (ANCOVA).

RESULTS

Mean baseline FNDT, HRSD, HAS, and CO levels of the groups were statistically similar. TEAT and SEAT groups demonstrated no significant changes in the outcome variables and smoking cessation rates (35.7% and 30%, respectively). Of those remaining outside of the study, 8.3% were from the TEAT group and 8.7% were from the SEAT group; there was no statistical difference between the groups. The rate of treatment discontinuation was similar between the TEAT (44%) and SEAT (43.7%) groups (p>0.05). The rates of adverse events were not similar too.

CONCLUSION

This study showed that both TEAT and SEAT have similar efficacy and safety profiles in patients with ND.

Drugs of abuse and blood-brain barrier endothelial dysfunction: A focus on the role of oxidative stress

Psychostimulants and nicotine are the most widely abused drugs with a detrimental impact on public health globally. While the long-term neurobehavioral deficits and synaptic perturbations are well documented with chronic use of methamphetamine, cocaine, and nicotine, emerging human and experimental studies also suggest an increasing incidence of neurovascular complications associated with drug abuse. Short- or long-term administration of psychostimulants or nicotine is known to disrupt blood-brain barrier (BBB) integrity/function, thus leading to an increased risk of brain edema and neuroinflammation. Various pathophysiological mechanisms have been proposed to underlie drug abuse-induced BBB dysfunction suggesting a central and unifying role for oxidative stress in BBB endothelium and perivascular cells. This review discusses drug-specific effects of methamphetamine, cocaine, and tobacco smoking on brain microvascular crisis and provides critical assessment of oxidative stress-dependent molecular pathways focal to the global compromise of BBB. Additionally, given the increased risk of human immunodeficiency virus (HIV) encephalitis in drug abusers, we have summarized the synergistic pathological impact of psychostimulants and HIV infection on BBB integrity with an emphasis on unifying role of endothelial oxidative stress. This mechanistic framework would guide further investigations on specific molecular pathways to accelerate therapeutic approaches for the prevention of neurovascular deficits by drugs of abuse.

Descriptive epidemiology and risk factors of primary central nervous system tumors: Current knowledge

Although comparisons are difficult due to differences in methodologies, the annual incidence rates of central nervous system (CNS) tumors range from 8.5 to 21.4/100,000 population according to cancer registries, with a predominance of neuroepithelial tumors in men and meningiomas in women. An increase in the incidence of CNS tumors has been observed during the past decades in several countries. It has been suggested that this trend could be due to aging of the population, and improvements in diagnostic imaging and healthcare access, but these factors do not explain differences in incidence by gender and histological subtypes. Several etiological hypotheses related to intrinsic (sociodemographic, anthropometric, hormonal, immunological, genetic) and exogenous (ionizing radiation, electromagnetic fields, diet, infections, pesticides, drugs) risk factors have led to analytical epidemiological studies to establish relationships with CNS tumors. The only established environmental risk factor for CNS tumors is ionizing radiation exposure. However, for other risk factors, studies have been inconsistent and inconclusive due to systematic differences in study design and difficulties in accurately measuring exposures. Thus, the etiology of CNS tumors is complex and may involve several genetic and/or environmental factors that may act differently according to histological subtype.

Synthetic Oligodeoxynucleotides Containing Multiple Telemeric TTAGGG Motifs Suppress Inflammasome Activity in Macrophages Subjected to Oxygen and Glucose Deprivation and Reduce Ischemic Brain Injury in Stroke-Prone Spontaneously Hypertensive Rats

The immune system plays a fundamental role in both the development and pathobiology of stroke. Inflammasomes are multiprotein complexes that have come to be recognized as critical players in the inflammation that ultimately contributes to stroke severity. Inflammasomes recognize microbial and host-derived danger signals and activate caspase-1, which in turn controls the production of the pro-inflammatory cytokine IL-1β. We have shown that A151, a synthetic oligodeoxynucleotide containing multiple telemeric TTAGGG motifs, reduces IL-1β production by activated bone marrow derived macrophages that have been subjected to oxygen-glucose deprivation and LPS stimulation. Further, we demonstrate that A151 reduces the maturation of caspase-1 and IL-1β, the levels of both the iNOS and NLRP3 proteins, and the depolarization of mitochondrial membrane potential within such cells. In addition, we have demonstrated that A151 reduces ischemic brain damage and NLRP3 mRNA levels in SHR-SP rats that have undergone permanent middle cerebral artery occlusion. These findings clearly suggest that the modulation of inflammasome activity via A151 may contribute to a reduction in pro-inflammatory cytokine production by macrophages subjected to conditions that model brain ischemia and modulate ischemic brain damage in an animal model of stroke. Therefore, modulation of ischemic pathobiology by A151 may have a role in the development of novel stroke prevention and therapeutic strategies.

Smoking and adult glioma: a population-based case-control study in China

BACKGROUND

Smoking increases the risk of numerous cancers; however, an association of smoking with adult gliomas has not been found in a population.

METHODS

This case-control study included 4556 glioma cases (ICD-9 code 191.0-191.9) aged ≥ 30 years and 9112 controls from a national survey of smoking and mortality in China in 1989-1991. Controls from 325 255 surviving spouses of all-cause deaths were randomly assigned to cases in each of 103 areas according to sex and age groups at a ratio of 2:1. Smoking information was ascertained retrospectively by interviewing surviving spouses.

RESULTS

After adjustment for confounders, smoking increased the risk of glioma deaths by 11% (odds ratio [OR] = 1.11; 95% confidence interval [CI]: 1.03-1.21). Compared with non-smokers; the increased risk was 9% (OR = 1.09; 95% CI: 0.99-1.20) in men and 16% (OR = 1.16; 95% CI: 1.00-1.36) in women. The risk increased with age and doses. For individuals aged ≥ 50 years, smoking was associated with higher risk of glioma death by 25% (OR = 1.25; 95% CI: 1.15-1.38); this increased risk for smokers who smoked ≥ 20 cigarettes daily for ≥ 30 years was 53% (OR = 1.53; 95% CI: 1.34-1.74). There were similar findings in both men and women and with either pathology-based or non-pathology-based comparisons.

CONCLUSIONS

This study indicates that smoking is associated with glioma deaths in the Chinese population. Long-term heavy smoking could be a factor for risk stratification in individuals attending brain tumor clinics.

Bacoside A: Role in Cigarette Smoking Induced Changes in Brain

Cigarette smoking (CS) is a major health hazard that exerts diverse physiologic and biochemical effects mediated by the components present and generated during smoking. Recent experimental studies have shown predisposition to several biological consequences from both active and passive cigarette smoke exposure. In particular, passive smoking is linked to a number of adverse health effects which are equally harmful as active smoking. A pragmatic approach should be considered for designing a pharmacological intervention to combat the adverse effects of passive smoking. This review describes the results from a controlled experimental condition, testing the effect of bacoside A (BA) on the causal role of passive/secondhand smoke exposure that caused pathological and neurological changes in rat brain. Chronic exposure to cigarette smoke induced significant changes in rat brain histologically and at the neurotransmitter level, lipid peroxidation states, mitochondrial functions, membrane alterations, and apoptotic damage in rat brain. Bacoside A is a neuroactive agent isolated from Bacopa monnieri. As a neuroactive agent, BA was effective in combating these changes. Future research should examine the effects of BA at molecular level and assess its functional effects on neurobiological and behavioral processes associated with passive smoke.

Targeting Household Air Pollution for Curbing the Cardiovascular Disease Burden: A Health Priority in Sub-Saharan Africa

Household air pollution (HAP) is a major public health problem, particularly in sub-Saharan Africa where most of the populations still rely on solid fuels for cooking, heating, and lighting. This narrative review highlights the direct and indirect evidence of the important role of HAP in cardiovascular disease, especially in sub-Saharan African countries where highest rates of major cardiovascular disease and death are observed, and thus provides ample reason for promotion of preventive interventions to reduce HAP exposures in the region. There is an urgent need for efficient strategies to educate populations on the health issues associated with this health hazard, to provide affordable clean cooking energy for poor people and to promote improved household ventilation. High-quality data on household energy practices and patterns of HAP and related health issues are still needed for efficient policy making in this region.

Arterial stiffness as a risk factor for cerebral aneurysm

OBJECTIVES

A low ankle-brachial index (ABI) is associated with increased mortality and risk of myocardial infarction and stroke in the general population. Arterial stiffness can be assessed non-invasively by the measurement of brachial-ankle pulse wave velocity (PWV), a simple and reproducible method. Because the importance of ABI and baPWV in the pathogenesis of cerebral aneurysms remains uncertain, we aimed to measure ABI and baPWV in patients with intracranial saccular and dissecting aneurysms to clarify whether these aneurysms are associated with arterial stiffness and atherosclerosis.

MATERIALS AND METHODS

We prospectively investigated 78 patients diagnosed with intracranial saccular (n = 66) and dissecting (n = 12) aneurysms. The control group consisted of an age- and gender-matched normal population. We compared the clinical characteristics in patients with intracranial saccular aneurysms and controls, those with intracranial dissecting aneurysms and controls, and those who had cerebral aneurysms with and without subarachnoid hemorrhage. We also compared ABI and baPWV among saccular aneurysm locations and evaluated the correlation between the number of saccular aneurysms and ABI and baPWV.

RESULTS

Multivariate logistic regression analysis shows that hypertension and higher baPWV (>1400 cm/s) are significantly associated with saccular aneurysms. Simple regression analysis revealed no correlation between the number of saccular aneurysms and ABI (r = -0.064, P = 0.611), and baPWV (r = 0.007, P = 0.956).

CONCLUSIONS

The baPWV was associated with intracranial saccular aneurysms even after adjustment of hypertension and smoking. Assessment of the baPWV may aid the evaluation of the intracranial saccular aneurysm and the development of strategies for screening patients with intracranial saccular aneurysms.

Rethinking hypertensive kidney disease: arterionephrosclerosis as a genetic, metabolic, and inflammatory disorder

PURPOSE OF REVIEW

Hypertension is the attributed cause of approximately 30% of end-stage kidney disease cases in the United States, but there has been controversy as to whether benign hypertension is a cause of chronic kidney disease.

RECENT FINDINGS

The histology of chronic kidney disease attributed to nonmalignant hypertension is arterionephrosclerosis, with pathology in the terminal branches of the interlobular arteries, together with global glomerulosclerosis. The identification of coding region variants in APOL1, encoding apolipoprotein L1, has opened a new perspective on this debate. These variants are restricted to populations of recent African descent and are strongly associated with clinically diagnosed arterionephrosclerosis, particularly when there is moderate-grade or high-grade proteinuria or progression to more advanced levels of kidney dysfunction. Nevertheless, not all African Americans with hypertension who progress to end-stage kidney disease have two APOL1 risk variants, and individuals of European and Asian descent also manifest arterionephrosclerosis. Further, we do not understand the mechanisms by which APOL1 initiates pathology in the renal microcirculation.

SUMMARY

APOL1 nephropathy comprises a disease spectrum (perhaps with distinct endophenotypes), including focal segmental glomerulosclerosis, collapsing glomerulopathy, and arterionephrosclerosis. The terms hypertensive kidney disease and hypertensive nephrosclerosis have outlived their usefulness. It may be time to use the established, etiologically neutral term, arterionephrosclerosis, to consider whether this is a disease rather than a pathologic description, and to determine the causal role of various clinical correlates including aging, obesity, hyperlipidemia, smoking, chronic inflammation, and oxidative stress.

Alpha-7 nicotinic acetylcholine receptor agonist treatment reduces neuroinflammation, oxidative stress, and brain injury in mice with ischemic stroke and bone fracture

Bone fracture at the acute stage of stroke exacerbates stroke injury by increasing neuroinflammation. We hypothesize that activation of α-7 nicotinic acetylcholine receptor (α-7 nAchR) attenuates neuroinflammation and oxidative stress, and reduces brain injury in mice with bone fracture and stroke. Permanent middle cerebral artery occlusion (pMCAO) was performed in C57BL/6J mice followed by tibia fracture 1 day later. Mice were treated with 0.8 mg/kg PHA 568487 (PHA, α-7 nAchR-specific agonist), 6 mg/kg methyllycaconitine (α-7 nAchR antagonist), or saline 1 and 2 days after pMCAO. Behavior was tested 3 days after pMCAO. Neuronal injury, CD68(+) , M1 (pro-inflammatory) and M2 (anti-inflammatory) microglia/macrophages, phosphorylated p65 component of nuclear factor kappa b in microglia/macrophages, oxidative and anti-oxidant gene expression were quantified. Compared to saline-treated mice, PHA-treated mice performed better in behavioral tests, had fewer apoptotic neurons (NeuN(+) TUNEL(+) ), fewer CD68(+) and M1 macrophages, and more M2 macrophages. PHA increased anti-oxidant gene expression and decreased oxidative stress and phosphorylation of nuclear factor kappa b p65. Methyllycaconitine had the opposite effects. Our data indicate that α-7 nAchR agonist treatment reduces neuroinflammation and oxidative stress, which are associated with reduced brain injury in mice with ischemic stroke plus tibia fracture. Bone fracture at the acute stage of stroke exacerbates neuroinflammation, oxidative stress, and brain injury, and our study has shown that the α-7 nAchR agonist, PHA (PHA 568487), attenuates neuroinflammation, oxidative stress, and brain injury in mice with stroke and bone fracture. Hence, PHA could provide an opportunity to develop a new strategy to reduce brain injury in patients suffering from stroke and bone fracture.

Microfluidic immunoassay for rapid detection of cotinine in saliva

A microfluidic immunoassay is successfully developed for rapid analysis of cotinine saliva samples, which is a metabolite of nicotine and is widely used as a biomarker to evaluate the smoking status and exposure to tobacco smoke. The core microfluidic chip is fabricated by polydimethylsiloxane (PDMS) with standard soft lithography. Each chip is capable of eight parallel analyses of cotinine samples. The analyses can be completed within 40 min with 12 μl sample consumption. The linear detection range is 1 ~ 250 ng/ml and the minimum detectable concentration is 1 ng/ml respectively. The correlation coefficient of the calibration curve established from standard samples is 0.9989. The immunoassay was also validated by real saliva samples, and the results showed good reproducibility and accuracy. All the results were confirmed with traditional ELISA measurements. The result from microfluidic chip device and ELISA kits showed good correspondence, and the correlation coefficients are higher than 0.99. Compared with traditional technique, this microfluidic immunoassay is more economic, rapid, simple and sensitive, perfect for on-site cotinine measurements as well as for the evaluation of the exposure to tobacco smoking. Moreover, this immunoassay has potential to be applied in the analysis of other biomarkers in human saliva samples.

Smoking and increased Alzheimer's disease risk: a review of potential mechanisms

BACKGROUND

Cigarette smoking has been linked with both increased and decreased risk for Alzheimer's disease (AD). This is relevant for the US military because the prevalence of smoking in the military is approximately 11% higher than in civilians.

METHODS

A systematic review of published studies on the association between smoking and increased risk for AD and preclinical and human literature on the relationships between smoking, nicotine exposure, and AD-related neuropathology was conducted. Original data from comparisons of smoking and never-smoking cognitively normal elders on in vivo amyloid imaging are also presented.

RESULTS

Overall, literature indicates that former/active smoking is related to a significantly increased risk for AD. Cigarette smoke/smoking is associated with AD neuropathology in preclinical models and humans. Smoking-related cerebral oxidative stress is a potential mechanism promoting AD pathology and increased risk for AD.

CONCLUSIONS

A reduction in the incidence of smoking will likely reduce the future prevalence of AD.