Nitric oxide-mediated blood flow regulation as affected by smoking and nicotine

Evaluation of serum nitric oxide synthase levels in patients with coronary slow flow based on corrected TIMI frame count

Introduction

The coronary slow flow phenomenon (CSFP) finding in angiography is characterized by the delayed filling of the terminal vessels without significant epicardial coronary disease. The endothelium performs a vital role in cardiovascular homeostasis by releasing vasoactive substances. Endothelial cells produce nitric oxide (NO) as one of these essential compounds. Three isoforms of nitric oxide synthase (NOS) are endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), and induced nitric oxide synthase (iNOS). We aimed to determine the role of NOS in the development of CSFP as the first human study.

Material and methods

A total of 129 patients who met the inclusion criteria were enrolled in the study. The patients were classified into five groups based on the results of coronary angiography: Group 1 without coronary artery disease (CAD) and without CSF, group 2 without CAD and with CSF, group 3 with CAD (< 50%) and without CSF, group 4 with CAD (50-90%) and without CSF, and group 5 with CAD and CSF. The serum level of NOS was determined in the participants. Coronary flow was quantified in patients with CSFP using the corrected TIMI frame count (CTFC) method, and the correlation between the levels of this biomarker and CTFC was investigated.

Results

In this study, the NOS serum levels were not significantly correlated with the mean CTFC. Since the total amount of NOS was measured as a result of 3 isoforms of this enzyme, the lack of correlation could be related to increased iNOS level and decreased eNOS concentration.

Conclusions

These results should be confirmed by more human studies.

Cigarette Smoke-Induced Respiratory Response: Insights into Cellular Processes and Biomarkers

Cigarette smoke (CS) poses a significant risk factor for respiratory, vascular, and organ diseases owing to its high content of harmful chemicals and reactive oxygen species (ROS). These substances are known to induce oxidative stress, inflammation, apoptosis, and senescence due to their exposure to environmental pollutants and the presence of oxidative enzymes. The lung is particularly susceptible to oxidative stress. Persistent oxidative stress caused by chronic exposure to CS can lead to respiratory diseases such as chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), and lung cancer. Avoiding exposure to environmental pollutants, like cigarette smoke and air pollution, can help mitigate oxidative stress. A comprehensive understanding of oxidative stress and its impact on the lungs requires future research. This includes identifying strategies for preventing and treating lung diseases as well as investigating the underlying mechanisms behind oxidative stress. Thus, this review aims to investigate the cellular processes induced by CS, specifically inflammation, apoptosis, senescence, and their associated biomarkers. Furthermore, this review will delve into the alveolar response provoked by CS, emphasizing the roles of potential therapeutic target markers and strategies in inflammation and oxidative stress.

Efficacy of urine loss ratio for prognosis of urinary continence after radical prostatectomy: A retrospective cohort study in a single Japanese institution

PURPOSE

The usefulness of the urine loss ratio in the early postoperative period for prognosis of long-term urinary continence after radical prostatectomy has not been fully determined.

MATERIALS AND METHODS

All patients who underwent radical prostatectomy for prostate cancer at our institution between November 2015 and March 2021 were retrospectively included. We investigated the rate of continence achievement 1 year after surgery, as well as the associated risk factors for reduced continence achievement, classified by every 10% of the urine loss ratio.

RESULTS

Of the 100 patients with available urine loss ratio data, 66 achieved urinary continence. Ninety-three percent of patients with urine loss ratios of ≤10%, 40%-75% of patients with urine loss ratios of 11%-80%, and 20%-36% of patients with urine loss ratios of >80%, achieved continence. The logistic regression analysis showed that the urine loss ratio severity, body mass index (BMI) of >25 kg/m², and smoking history were unfavorable to achieve urinary continence. A BMI of ≤25 kg/m² was favorable for urinary continence achievement, but only up to an 80% urine loss ratio. Nonsmokers achieved continence well, even with a urine loss ratio of >80%.

CONCLUSIONS

Classifying patients into three groups based on their urine loss ratios is potentially useful for urinary continence prognosis. Smoking and obesity were risk factors for continued urinary incontinence, although the prognostic accuracy was expected to improve when considering the severity of the urine loss ratio.

Recent Smoking History Is Not Associated with Adverse 30-Day Standardized Postoperative Outcomes following Microsurgical Reconstructive Procedures of the Upper Extremity

Background: Upper extremity (UE) microsurgical reconstruction relies upon proper wound healing for optimal outcomes. Cigarette smoking is associated with wound healing complications, yet conclusions vary regarding impact on microsurgical outcomes (replantation, revascularization, and free tissue transfer). We investigated how smoking impacted 30-day standardized postoperative outcomes following UE microsurgical reconstruction. Methods: Utilizing the National Surgical Quality Improvement Program, all patients who underwent (1) UE free flap transfer (n = 70) and (2) replantation/revascularization (n = 270) were identified. For each procedure, patients were stratified by recent smoking history (current smoker ≤1-year preoperatively). Baseline demographics and standardized 30-day complications, reoperations, and readmissions were compared between smokers and nonsmokers. Results: Replantation/revascularization patients had no differences in sex, race, or body mass index between smokers (n = 77) and nonsmokers. Smokers had a higher prevalence of congestive heart failure (5.2% vs 1.0%, P = .036) and nonsmokers were more often on hemodialysis (15.6% vs 10.4%, P = .030). Free flap transfer patients had no differences in age, sex, or race between smokers (n = 14) and nonsmokers. Smokers had a longer length of stay (6.6 vs 4.2 days, P = .001) and a greater prevalence of chronic obstructive pulmonary disorder (COPD; 7.1% vs 0%, P = .044). Recent smoking was not associated with increased odds of any 30-day minor and major standardized surgical complications, readmissions, or reoperations following UE microsurgical reconstruction via free flap transfer or replantation/revascularization. Baseline diagnosis of COPD was also not a predictor of adverse 30-day outcomes following free flap transfer. Conclusion: Recent smoking history was not associated with any 30-day adverse outcomes following UE microsurgical reconstruction via replantation/revascularization or free flap transfer. In light of these findings, further investigation is warranted, with particular focus on adverse events specific to free flaps and replantation/revascularization.

Cigarette smoking and erectile dysfunction: an updated review with a focus on pathophysiology, e-cigarettes, and smoking cessation

Introduction

Cigarette smoking has major health implications and causes substantial damage to all organ systems. Approximately one-third of men are active smokers worldwide, and most men are unaware that cigarette smoking can contribute to erectile dysfunction (ED).

Objectives

This article aims to provide a comprehensive overview of research conducted on cigarette smoking and ED, with a particular focus on pathophysiology, electronic cigarettes (e-cigarettes), and smoking cessation.

Methods

A manual literature search was conducted on all research conducted on cigarette smoking and ED up to October 2022.

Results

Substantial evidence is now available showing that past and current cigarette smoking has dose-dependent associations with ED in studies controlling for age and important health comorbidities. Cigarette smoke contains nicotine, carbon monoxide, oxidant chemicals, and metals that can damage the endothelium and disrupt erectile processes. For current smokers, smoking abstinence can strengthen the endothelium and reverse diminished erectile function. The effect of e-cigarettes on endothelial damage and ED remains largely untested. E-cigarettes expose users to fine and ultrafine particles and toxins that can increase risk of cardiovascular injury, but these acute effects appear less potent than conventional cigarettes (long-term cardiovascular effects are still unknown). E-cigarettes are therefore likely to have less harmful effects on ED than conventional cigarettes.

Conclusions

Smoking cessation programs that focus on nicotine replacement therapy (transdermal patches, gum, or inhalers), behavioral counseling, social support, and education programs can be effective approaches to ED treatment in active smokers. Temporarily transferring from regular cigarettes to e-cigarettes—which transmit some of the same carcinogens as conventional cigarettes and are likely to have some long-term cardiovascular effects that disrupt erectile function—might also be useful for long-term smoking cessation and treatment of ED.

Skin necrosis following sclerotherapy. Part 2: Risk minimisation and management strategies

Tissue necrosis is a serious but rare complication of sclerotherapy. Early detection and targeted management are essential to prevent progression and minimise serious complications. In the first instalment of this paper, we reviewed the pathogenic mechanisms of post-sclerotherapy necrosis. Here, we describe risk minimisation and management strategies.

Risk factors must be addressed to reduce the chance of necrosis following sclerotherapy. These may be treatment-related including poor choice of sclerosant type, concentration, volume or format, poor injection technique, suboptimal ultrasound visualisation and treatment of vessels in high-risk anatomical areas. Risk factors specific to individual patients should be identified and optimised pre-operatively.

Tissue necrosis is more likely to occur with extravasation of irritant sclerosants such as absolute alcohol, sodium iodide, bleomycin and hypertonic saline, whereas extravasation of foam detergent sclerosants rarely results in tissue loss. Proposed treatments for extravasation of irritant sclerosants include infiltration of an isotonic fluid and hyaluronidase. Management of inadvertent intra-arterial injections may require admission for neurovascular observation and monitoring for ischaemia, intravenous systemic steroids, anticoagulation, thrombolysis and prostanoids infusion when required. Treatment of veno-arteriolar reflex vasospasm (VAR-VAS) necrosis follows the same protocol involving systemic steroids but rarely requires hospital admission and may not require anticoagulation.

In general, treatment of post-sclerotherapy necrosis is challenging and most proposed treatment measures are not evidence-based and only supported by anecdotal personal experience of clinicians. Despite all measures, once the necrosis has set in, it is very difficult to reverse the process and all measures described here may only be useful in prevention of progression and extension of the ulceration.

Mid to long-term measures include addressing exacerbating factors, management of medical and psychosocial comorbidities, treatment of secondary infections and referrals to relevant specialists. All ulcers should be managed with compression and prescribed dressing regimes in line with the healing stage of the ulcer.

Changes in Magnetic Resonance Signal Fluctuation in Superior Sagittal Sinus: Deterioration of Arteriolar Vasomotor Function of Young Smokers

(1) Cerebral arteriolar vasomotor function is vital for brain health and has been examined through CO₂ inhalation or breath-holding, which are both challenging for patients. We have developed a non-invasive method to evaluate this function with magnetic resonance imaging (MRI) by utilizing respiration-induced natural changes in partial pressure of arterial CO₂ (PaCO₂). In this study, we applied this method for 20s to evaluate the chronic effect of a few years smoking on the cerebral arteriolar vasomotor function. (2) A single slice (five slice thicknesses: 15 mm to 7 mm) perpendicular to the superior sagittal sinus of was imaged successively for 45 s using spin-echo echo-planar imaging by 3T MRI for ten smokers (24.5 ± 1.6 years) and ten non-smokers (24.3 ± 1.4 years), respectively. The venous oxygenation fluctuation (ΔY_r) caused by the respiration-induced changes of PaCO₂, which reflects the arteriolar vasomotor function, was calculated from the time series MR signal changes of superior sagittal sinus. (3) The ΔY_r values of the smokers (0.7 ± 0.6) were significantly lower than those of the non-smokers (1.3 ± 0.8) (p = 0.04). (4) Degeneration of the cerebral arteriolar vasomotor function due to chronic smoking (even after 20s) was demonstrated by our non-invasive MRI-based method.

Secondhand Smoke Exposure Impairs Ion Channel Function and Contractility of Mesenteric Arteries

Cigarette smoke, including secondhand smoke (SHS), has significant detrimental vascular effects, but its effects on myogenic tone of small resistance arteries and the underlying mechanisms are understudied. Although it is apparent that SHS contributes to endothelial dysfunction, much less is known about how this toxicant alters arterial myocyte contraction, leading to alterations in myogenic tone. The study's goal is to determine the effects of SHS on mesenteric arterial myocyte contractility and excitability. C57BL/6J male mice were randomly assigned to either filtered air (FA) or SHS (6 h/d, 5 d/wk) exposed groups for a 4, 8, or 12-weeks period. Third and fourth-order mesenteric arteries and arterial myocytes were acutely isolated and evaluated with pressure myography and patch clamp electrophysiology, respectively. Myogenic tone was found to be elevated in mesenteric arteries from mice exposed to SHS for 12 wk but not for 4 or 8 wk. These results were correlated with an increase in L-type Ca2+ channel activity in mesenteric arterial myocytes after 12 wk of SHS exposure. Moreover, 12 wk SHS exposed arterial myocytes have reduced total potassium channel current density, which correlates with a depolarized membrane potential (Vm). These results suggest that SHS exposure induces alterations in key ionic conductances that modulate arterial myocyte contractility and myogenic tone. Thus, chronic exposure to an environmentally relevant concentration of SHS impairs mesenteric arterial myocyte electrophysiology and myogenic tone, which may contribute to increased blood pressure and risks of developing vascular complications due to passive exposure to cigarette smoke.

Modulation of preeclampsia by the cholinergic anti-inflammatory pathway: Therapeutic perspectives

The cholinergic anti-inflammatory pathway (CAP) is vital for the orchestration of the immune and inflammatory responses under normal and challenged conditions. Over the past two decades, peripheral and central circuits of CAP have been shown to be critically involved in dampening the inflammatory reaction in a wide array of inflammatory disorders. Additionally, emerging evidence supports a key role for CAP in the regulation of the female reproductive system during gestation as well as in the advent of serious pregnancy-related inflammatory insults such as preeclampsia (PE). Within this framework, the modulatory action of CAP encompasses the perinatal maternal and fetal adverse consequences that surface due to antenatal PE programming. Albeit, a considerable gap still exists in our knowledge of the precise cellular and molecular underpinnings of PE/CAP interaction, which hampered global efforts in safeguarding effective preventive or therapeutic measures against PE complications. Here, we summarize reports in the literature regarding the roles of peripheral and reflex cholinergic neuroinflammatory pathways of nicotinic acetylcholine receptors (nAChRs) in reprogramming PE complications in mothers and their progenies. The possible contributions of α7-nAChRs, cholinesterases, immune cells, adhesion molecules, angiogenesis, and endothelial dysfunction to the interaction have also been reviewed.

Retrospective study on rib fractures: smoking and alcohol matter for mortality and complications

Background

Rib fractures and substance use are both common in trauma patients, but there is little data on how smoking and alcohol use may be associated with outcomes in these patients. We assessed the association between smoking or alcohol use disorder (AUD) and outcomes in patients with rib fractures.

Methods

We used institutional databases to conduct a retrospective review of patients with rib fractures at the only American College of Surgeons-verified adult level 1 trauma center in a rural state between 2015 and 2019. The key exposure variables were smoking and AUD. The key outcome variables were mortality and pulmonary complications (pneumonia, adult respiratory distress syndrome, and pneumothorax). We used multivariable regression for analysis and directed acyclic graphs to identify variables for adjustment.

Results

We identified 1880 eligible patients with rib fractures, including 693 (37%) who were smokers and 204 (11%) who had AUD. Compared with non-smokers, smokers were younger, more often male, and had lower mortality rates. Regression showed that smokers had a lower likelihood of mortality (OR 0.48; 95% CI 0.27 to 0.87; p=014). Likelihood of pneumonia, ARDS, and pneumothorax was not different between smokers and non-smokers. Compared with patients without AUD, patients with AUD were older, more often male, and had higher likelihood of pneumonia and lower likelihood of pneumothorax. Regression showed that patients with AUD had higher likelihood of pneumonia (OR 1.82; 95% CI 1.24 to 2.68; p=0.002) and lower likelihood of pneumothorax (OR 0.51; 95% CI 0.33 to 0.75; p=0.002).

Discussion

In trauma patients with rib fractures treated at a level 1 trauma center over 5 years, smoking was associated with decreased risk of mortality. These findings have implications for risk stratification and clinical decision-making for patients with rib fractures.

Level of evidence

III

Piper sarmentosum Roxb. Attenuates Vascular Endothelial Dysfunction in Nicotine-Induced Rats

Exposure to cigarette smoke is an important risk factor for cardiovascular diseases. Nicotine is an addictive compound in cigarette smoke that triggers oxidative stress, which leads to vascular dysfunction. Piper sarmentosum Roxb. is a herb with antioxidant and vascular protective effects. This study evaluated the potential protective effect of the aqueous extract of P. sarmentosum leaf (AEPS) on vascular dysfunction in rats induced with prolonged nicotine administration. A total of 22 male Sprague-Dawley rats were divided into control (normal saline, oral gavage [p.o.]), nicotine (0.8 mg/kg/day nicotine, intraperitoneally [i.p.]), and nicotine + AEPS groups (250 mg/kg/day AEPS, p.o. + 0.8 mg/kg/day nicotine, i.p.). Treatment was given for 21 days. Thoracic aortae were harvested from the rats for the measurement of vasorelaxation, vascular nitric oxide (NO) level, and antioxidant level and the assessment of vascular remodeling. Rats treated with AEPS had improved vasorelaxation to endothelium-dependent vasodilator, acetylcholine (ACh), compared with the nicotine-induced rats (p < 0.05). The presence of endothelium increased the maximum relaxation of aortic rings in response to ACh. Compared with the nicotine group, AEPS enhanced vascular NO level (p < 0.001) and increased antioxidant levels as measured by superoxide dismutase activity (p < 0.05), catalase activity (p < 0.01), and reduced glutathione level (p < 0.05). No remarkable changes in aortic histomorphometry were detected. In conclusion, P. sarmentosum attenuates vascular endothelial dysfunction in nicotine-induced rats by improving vasorelaxation and enhancing vascular NO and antioxidant levels.

Cold-induced vasodilation in abstinent smokers with and without a 12-hour nicotine patch

This study was designed to identify the effects of a 12-h nicotine patch administration on cold induced vasodilation (CIVD) in healthy young chronic smokers following 16 h of abstinence from smoking. Two laser Doppler probes and temperature thermocouples were placed on the dorsal part of the distal phalanx of the middle and ring fingers of 7 smokers (>12 cigarettes/day). Following 16 h of abstinence from smoking, smokers were tested with and without administration of a 21 mg transdermal nicotine patch (NicoDerm^® ). Each participant's right hand was immersed in cold (~5°C) water for 40 min. Cutaneous vascular conductance (CVC) was calculated from non-invasive arterial finger blood pressure and skin blood flow and expressed as a percentage of peak CVC observed during hand skin heating to 44°C. For comparison purposes, the CIVD response of a non-smoking cohort without nicotine patch (n = 10) was also examined. Baseline CVC was similar in smokers and non-smokers (27.8 ± 12.6 CVC % peak). The initial vasoconstriction during cold-water immersion decreased skin blood flow to 4.0 ± 3.9 CVC % peak in both smokers and non-smokers. The onset of CIVD in smokers (4.5 ± 1.5 min) was delayed compared to non-smoker (3.3 ± 0.8 min, p < .05). The area under the CVC %peak-time curve during cold-water immersion averaged 1250 ± 388 CVC %peak · min in non-smokers which was larger (p < .05) than smokers with or without nicotine (789 ± 542 and 862 ± 517 CVC %peak · min, respectively). Chronic smoking impaired the CIVD response to cold-water immersion of the hand; however, the impaired CIVD response in 16 h of abstinence from smoking was not influenced by application of a 21 mg transdermal nicotine patch.

Nicotine and vascular dysfunction

Cigarette smoking is the single most important risk factor for the development of cardiovascular diseases (CVDs). However, the role of nicotine, the addictive component of all tobacco products, in the development of CVD is incompletely understood. Although increased public awareness of the harms of cigarette smoking has successfully led to a decline in its prevalence, the use of electronic cigarettes (e-cig) or electronic nicotine delivery system has increased dramatically in recent years because of the perception that these products are safe. This review summarizes our current knowledge of the expression and function of the nicotinic acetylcholine receptors in the cardiovascular system and the impact of nicotine exposure on cardiovascular health, with a focus on nicotine-induced vascular dysfunction. Nicotine alters vasoreactivity through endothelium-dependent and/or endothelium-independent mechanisms, leading to clinical manifestations in both cigarette smokers and e-cig users. In addition, nicotine induces vascular remodelling through its effects on proliferation, migration and matrix production of both vascular endothelial and vascular smooth muscle cells. The purpose of this review is to identify critical knowledge gaps regarding the effects of nicotine on the vasculature and to stimulate continued nicotine research.

Early Detection of Negative Smoking Impacts: Vascular Adaptation Deviation Based on Quantification of Circulated Endothelial Activation Markers

Introduction

Smoking can cause vascular damage in the form of an inflammatory reaction characterized by endothelial activation. Endothelial activation forms a pathological adaptation pattern so that it can induce the atherogenesis process. Several markers, such as E-selectin, platelet-derived micro particles (PMPs) and hematopoietic stem cell (HSC) can identify the activation of endothelial in circulating blood. Therefore, the deviation of vascular adaptation due to smoking can be detected early through the feedback mechanism between E-selectin, PMPs, and HSC.

Purpose

This study aims to analyze the initial picture of the negative impact of smoking on vascular adaptation by measuring E-selectin, PMPs, and HSC in the peripheral blood circulation. Participant criteria and methods: Peripheral blood samples (5 mL) were taken from each participant, both the smoking group (n = 30) and the non-smoker group (n = 31) to obtain peripheral blood mononuclear cells (PBMNC). PBMNC was isolated using ficoll-based gradient centrifugation. The flow cytometry assay method used to measure the E-selectin, PMPs and hematopoietic stem cells.

Results

The mean of circulating E-selectin in smokers was higher than that of non-smokers. On the other hand, the average number of PMPs and HSCs in smokers was lower than non-smokers.

Conclusion

Smoking increases the risk of accelerated vascular block formation, as indicated by an increase in the amount of circulating E-selectin. The increase in E-selectin in the blood vessels mediates the increased adhesion of PMPs in the vascular area so that the number of circulating PMPs in smokers decreases. The decrease in circulating PMPs decreases the signal of vascular repair, which is characterized by a decline in the number of HSCs.

Gender-biased kidney damage in mice following exposure to tobacco cigarette smoke: More protection in premenopausal females

Multiple clinical studies documented renal damage in chronic cigarette smokers (CS) irrespective of their age and gender. Premenopausal female smokers are known to exert a certain cardiovascular and renal protection with undefined mechanisms. Given the multiple demographic variables within clinical studies, this experimental study was designed to be the first to assess whether gender‐biased CS‐induced kidney damage truly exists between premenopausal female and age‐matched C57Bl6J male mice when compared to their relative control groups. Following 6 weeks of CS exposure, cardiac function, inflammatory marker production, fibrosis formation, total and glomerular ROS levels, and glomerulotubular homeostasis were assessed in both genders. Although both CS‐exposed male and female mice exhibited comparable ROS fold change relative to their respective control groups, CS‐exposed male mice showed a more pronounced fibrotic deposition, inflammation, and glomerulotubular damage profile. However, the protection observed in CS‐exposed female group was not absolute. CS‐exposed female mice exhibited a significant increase in fibrosis, ROS production, and glomerulotubular alteration but with a pronounced anti‐inflammatory profile when compared to their relative control groups. Although both CS‐exposed genders presented with altered glomerulotubular homeostasis, the alteration phenotype between genders was different. CS‐exposed males showed a significant decrease in Bowman's space along with reduced tubular diameter consistent with an endocrinization pattern of chronic tubular atrophy, suggestive of an advanced stage of glomerulotubular damage. CS‐exposed female group, on the other hand, displayed glomerular hypertrophy with a mild tubular dilatation profile suggestive of an early stage of glomerulotubular damage that generally precedes collapse. In conclusion, both genders are prone to CS‐induced kidney damage with pronounced female protection due to a milder damage slope.

Nitric oxide's physiologic effects and potential as a therapeutic agent against COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for COVID-19 pneumonia, a pandemic that precipitates huge pressures on the world's social and economic systems. Disease severity varies among individuals. SARS-CoV-2 infection can be associated with e.g. flu-like symptoms, dyspnoea, severe interstitial pneumonia, acute respiratory distress syndrome, multiorgan dysfunction, and generalized coagulopathy. Nitric oxide (NO), is a small signal molecule that impacts pleiotropic functions in human physiology, which can be involved in the significant effects of COVID-19 infection. NO is a neurotransmitter involved in the neural olfactory processes in the central nervous system, and some infected patients have reported anosmia as a symptom. Additionally, NO is a well-known vasodilator, important coagulation mediator, anti-microbial effector and inhibitor of SARS-CoV replication. Exhaled NO is strongly related to the type-2 inflammatory response found in asthma, which has been suggested to be protective against SARS-CoV-2 infection. Several reports indicate that the use of inhaled NO has been an effective therapy during this pandemic since the ventilation-perfusion ratio in COVID-19 patients improved afterwards and they did not require mechanical ventilation. The aim of this mini-review is to summarize relevant actions of NO that could be beneficial in the treatment of COVID-19.

Metastasis-Specific Gene Expression in Autochthonous and Allograft Mouse Mammary Tumor Models: Stratification and Identification of Targetable Signatures

Breast cancer metastasis is a leading cause of cancer-related death of women in the United States. A hurdle in advancing metastasis-targeted intervention is the phenotypic heterogeneity between primary and secondary lesions. To identify metastasis-specific gene expression profiles we performed RNA-sequencing of breast cancer mouse models; analyzing metastases from models of various drivers and routes. We contrasted the models and identified common, targetable signatures. Allograft models exhibited more mesenchymal-like gene expression than genetically engineered mouse models (GEMM), and primary culturing of GEMM-derived metastatic tissue induced mesenchymal-like gene expression. In addition, metastasis-specific transcriptomes differed between tail vein and orthotopic injection of the same cell line. Gene expression common to models of spontaneous metastasis included sildenafil response and nicotine degradation pathways. Strikingly, in vivo sildenafil treatment significantly reduced metastasis by 54%, while nicotine significantly increased metastasis by 46%. These data suggest that (i) actionable metastasis-specific pathways can be readily identified, (ii) already available drugs may have great potential to alleviate metastatic incidence, and (iii) metastasis may be influenced greatly by lifestyle choices such as the choice to consume nicotine products. In summary, while mouse models of breast cancer metastasis vary in ways that must not be ignored, there are shared features that can be identified and potentially targeted therapeutically. IMPLICATIONS: The data we present here exposes critical variances between preclinical models of metastatic breast cancer and identifies targetable pathways integral to metastatic spread. VISUAL OVERVIEW: http://mcr.aacrjournals.org/content/molcanres/18/9/1278/F1.large.jpg.

Elevated pigment epithelium-derived factor induces diabetic erectile dysfunction via interruption of the Akt/Hsp90β/eNOS complex

AIMS/HYPOTHESIS

Diabetes mellitus erectile dysfunction (DMED) is a common complication of diabetes. The level of pigment epithelium-derived factor (PEDF) is significantly upregulated in the serum of individuals with obesity and diabetes. However, whether elevated PEDF levels contribute to DMED remains unknown. This study aimed to investigate the pathogenic role of PEDF and its related mechanism in DMED.

METHODS

We enrolled 65 men, of whom 20 were nondiabetic control participants, 21 participants with diabetes but without erectile dysfunction, and 24 with DMED. The International Index of Erectile Function (IIEF-5) questionnaire was administered to evaluate erectile function. Plasma PEDF in diabetic participants and streptozotocin (STZ)-induced diabetic animals was detected by ELISA. Erectile function was evaluated by measuring the intracavernous pressure (ICP) and the ICP/mean arterial pressure (MAP) ratio in STZ-induced diabetic rats treated with PEDF-neutralising antibody (PEDF-Ab), db/db mice treated with PEDF-Ab, and Pedf knockout mice with STZ-induced diabetes. The overexpression of PEDF was implemented by intraperitoneal injection of recombinant PEDF and intracavernous injection of PEDF-expressing adenovirus. A mechanistic study was performed by immunofluorescence staining, bimolecular fluorescence complementation (BiFC), immunoprecipitation and western blotting.

RESULTS

We found that the plasma level of PEDF was significantly higher in participants with DMED compared with diabetic counterparts without erectile dysfunction and nondiabetic controls. Interestingly, PEDF levels were negatively correlated with plasma nitrite/nitrate levels and erectile function in DMED patients and STZ-induced diabetic rats. Furthermore, overexpression of PEDF significantly suppressed ICP and endothelial nitric oxide synthase (eNOS) phosphorylation in control rats. In contrast, the PEDF-Ab and Pedf knockout ameliorated ICP and eNOS phosphorylation in diabetic rats and mice. Mechanistically, PEDF promoted the membrane translocation of Hsp90β and directly bound to the amino acid residues 341-724 of Hsp90β on the endothelial cell surface, subsequently blocking intracellular Hsp90β/Akt/eNOS complex formation and downregulating eNOS phosphorylation.

CONCLUSIONS/INTERPRETATION

These results indicate that elevated PEDF levels contribute to impaired erectile function by suppressing Hsp90β-mediated eNOS phosphorylation and that PEDF may represent a novel therapeutic target for diabetic erectile dysfunction. Graphical abstract.

Review article: impact of cigarette smoking on intestinal inflammation-direct and indirect mechanisms

BACKGROUND

The inflammatory bowel diseases, Crohn's disease and ulcerative colitis are related multifactorial diseases. Their pathogenesis is influenced by each individual's immune system, the environmental factors within exposome and genetic predisposition. Smoking habit is the single best-established environmental factor that influences disease phenotype, behaviour and response to therapy.

AIM

To assess current epidemiological, experimental and clinical evidence that may explain how smoking impacts on the pathogenesis of inflammatory bowel disease.

METHODS

A Medline search for 'cigarette smoking', in combination with terms including 'passive', 'second-hand', 'intestinal inflammation', 'Crohn's disease', 'ulcerative colitis', 'colitis'; 'intestinal epithelium', 'immune system', 'intestinal microbiota', 'tight junctions', 'mucus', 'goblet cells', 'Paneth cells', 'autophagy'; 'epigenetics', 'genes', 'DNA methylation', 'histones', 'short noncoding/long noncoding RNAs'; 'carbon monoxide/CO' and 'nitric oxide/NO' was performed.

RESULTS

Studies found evidence of direct and indirect effects of smoking on various parameters, including oxidative damage, impairment of intestinal barrier and immune cell function, epigenetic and microbiota composition changes, that contribute to the pathogenesis of inflammatory bowel disease.

CONCLUSIONS

Cigarette smoking promotes intestinal inflammation by affecting the function and interactions among intestinal epithelium, immune system and microbiota/microbiome.

Passive Cigarette Smoking Impact on Blood Pressure Response to Epinephrine and Felypressin in 1K1C Hypertensive Rats Treated or not with Atenolol

Background

Cigarette smoking is usually associated with hypertension and may modify vasoconstrictor response.

Objective

The present study aimed to analyze and compare the interaction of passive cigarette smoking and hypertension on epinephrine and felypressin blood pressure effects after intravascular injection.

Method

45-day male Wistar rats had the main left renal artery partially constricted and the right kidney removed (1K1C model). Rats were placed in the chamber for exposition to passive cigarette smoking (10 cigarettes) during 10 min (6 days a week). Hypertensive rats received atenolol (90 mg/kg/day) by gavage for two weeks. Hypotensive and hypertensive response, response duration and heart rate were recorded from direct blood pressure values. The significance level was 5%.

Results

Passive cigarette smoking increased maximal hypertensive response to epinephrine in normotensive and 1K1C-atenolol treated rats and to felypressin only in 1K1C-atenolol treated rats; it also reduced epinephrine hypotensive response. Epinephrine increased heart rate in normotensive and hypertensive passive smokers or non-smoker rats. Comparing the two vasoconstrictors, epinephrine showed greater hypertensive response in normotensive smokers, 1K1C-atenolol treated smokers and non-smokers. However, in normotensive-nonsmoker rats, felypressin showed a greater and longer hypertensive effect.

Conclusions

Our results suggest that passive cigarette smoking may reduce epinephrine vasodilation and increase hypertensive response when compared to felypressin. Therefore, felypressin may be safe for hypertensive patients to avoid tachycardia and atenolol interaction, but for normotensive and non-smoker patients, epinephrine may be safer than felypressin.

The Effect of Nitric Oxide on Remote Ischemic Preconditioning in Renal Ischemia Reperfusion Injury in Rats

Although remote ischemic preconditioning (RIPC) is an organ-protective maneuver from subsequent ischemia reperfusion injury (IRI) by application of brief ischemia and reperfusion to other organs, its mechanism remains unclear. However, it is known that RIPC reduces the heart, brain, and liver IRI, and that nitric oxide (NO) is involved in the mechanism of this effect. To identify the role of NO in the protective effect of RIPC in renal IRI, this study examined renal function, oxidative status, and histopathological changes using N-nitro-L-arginine methyl ester (L-NAME), an NO synthase inhibitor. Remote ischemic preconditioning was produced by 3 cycles of 5 minutes ischemia and 5 minutes reperfusion. Blood urea nitrogen, creatinine (Cr), and renal tissue malondialdehyde levels were lower, histopathological damage was less severe, and superoxide dismutase level was higher in the RIPC + IRI group than in the IRI group. The renoprotective effect was reversed by L-NAME. Obtained results suggest that RIPC before renal IRI contributes to improvement of renal function, increases antioxidative marker levels, and decreases oxidative stress marker levels and histopathological damage. Moreover, NO is likely to play an important role in this protective effect of RIPC on renal IRI.

Effect of Paired Associative Stimulation on Corticomotor Excitability in Chronic Smokers

Chronic smoking has been shown to have deleterious effects on brain function and is an important risk factor for ischemic stroke. Reduced cortical excitability has been shown among chronic smokers compared with non-smokers to have a long-term effect and so far no study has assessed the effect of smoking on short-term motor learning. Paired associative stimulation (PAS) is a commonly used method for inducing changes in excitability of the motor cortex (M1) in a way that simulates short-term motor learning. This study employed PAS to investigate the effect of chronic cigarette smoking on plasticity of M1. Stimulator output required to elicit a motor-evoked potential (MEP) of approximately 1 mV was similar between the groups prior to PAS. MEP response to single pulse stimuli increased in the control group and remained above baseline level for at least 30 min after the intervention, but not in the smokers who showed no significant increase in MEP size. The silent period was similar between groups at all time points of the experiment. This study suggests that chronic smoking may have a negative effect on the response to PAS and infers that chronic smoking may have a deleterious effect on the adaptability of M1.

Deletion of nicotinic acetylcholine receptor alpha9 in mice resulted in altered bone structure

Alterations in bone strength and structure were found in knockout (KO) mouse strains with deletion of several acetylcholine receptors. Interestingly, the expression of the nicotinic acetylcholine receptors (nAChR) subunit α10 was down-regulated in osteogenic differentiated mesenchymal stem cells of patients with osteoporosis whereas the expression of subunit α9 was not altered. Since nAChR subunits α9 and α10 are often combined in a functional receptor, we analyzed here the bone of adult female KO mice with single deletion of either nAChR alpha9 (α9KO) or alpha10 (α10KO). Biomechanical testing showed a significant decrease of bending stiffness and maximal breaking force in α9KO compared to their corresponding wild type mice. Furthermore, an increase in trabecular pattern factor (Tb.Pf) and structure model index (SMI) was detected by μCT in α9KO indicating reduced bone mass. On the mRNA level a decrease of Collagen 1α1 and Connexin-43 was measured by real-time RT-PCR in α9KO while no alteration of osteoclast markers was detected in either mouse strain. Using electron microcopy we observed an increase in the number of osteocytes that showed signs of degeneration and cell death in the α9KO compared to their wild type mice, while α10KO showed no differences. In conclusion, we demonstrate alterations in bone strength, structure and bio-marker expression in α9KO mice which imply the induction of osteocyte degeneration. Thus, our data suggest that nAChR containing the α9 subunit might be involved in the homeostasis of osteocytes and therefore in bone mass regulation.

Does dietary nitrate say NO to cardiovascular ageing? Current evidence and implications for research

CVD are characterised by a multi-factorial pathogenesis. Key pathogenetic steps in the development of CVD are the occurrence of endothelial dysfunction and formation of atherosclerotic lesions. Reduced nitric oxide (NO) bioavailability is a primary event in the initiation of the atherosclerotic cascade. NO is a free radical with multiple physiological functions including the regulation of vascular resistance, coagulation, immunity and oxidative metabolism. The synthesis of NO proceeds via two distinct pathways identified as enzymatic and non-enzymatic. The former involves the conversion of arginine into NO by the NO synthases, whilst the latter comprises a two-step reducing process converting inorganic nitrate $({\rm NO}_3^ - )$ into nitrite and subsequently NO.

Inorganic ${\rm NO}_3^ - $ is present in water and food, particularly beetroot and green leafy vegetables. Several investigations have therefore used the non-enzymatic NO pathway as a target for nutritional supplementation (${\rm NO}_3^ - $ salts) or dietary interventions (high-${\rm NO}_3^ - $ foods) to increase NO bioavailability and impact on cardiovascular outcomes. Some studies have reported positive effects of dietary ${\rm NO}_3^ - $ on systolic blood pressure and endothelial function in patients with hypertension and chronic heart failure. Nevertheless, results have been inconsistent and the size of the effect appears to be declining in older individuals. Additionally, there is a paucity of studies for disorders such as diabetes, CHD and chronic kidney failure. Thus, whilst dietary ${\rm NO}_3^ - $ supplementation could represent an effective and viable strategy for the primary and secondary prevention of age-related cardiovascular and metabolic diseases, more large-scale, robust studies are awaited to confirm or refute this notion.

Invasion-inhibiting Effects of Gaseous Components in Cigarette Smoke on Mouse Rectal Carcinoma Colon-26 Cells

We investigated the anti-metastatic action of nicotine- and tar-removed cigarette smoke extract (CSE) on highly metastatic mouse Colon-26 cells using syngeneic BALB/c mice. Colon-26 cells were injected into the spleen of mice, cells were grown in the spleen as the primary lesion, and some metastasized from the spleen to liver and established a metastatic lesion. CSE (10, 30, and 100%) was intraperitoneally administered daily to the mice for 14 days after tumor inoculation. As a result, the relative spleen weights of CSE-administered mice did not differ significantly from those of the control mice. However, the relative liver weights of CSE 30%-administered mice significantly decreased compared to control mice. In order to identify the active component in CSE, we examined the action of methyl vinyl ketone (MVK) on the invasiveness of Colon-26 cells. MVK significantly reduced the invasiveness of cells. MVK may be a candidate active component of CSE.

Smoking as an Independent Risk Factor for Postoperative Complications in Plastic Surgical Procedures: A Propensity Score-Matched Analysis of 36,454 Patients from the NSQIP Database from 2005 to 2014

BACKGROUND

Smoking has been associated with wound healing complications and overall morbidity in multiple specialties, including plastic surgery. From 2005 to 2014, smoking prevalence among U.S. adults decreased from 20.9 percent to 16.8 percent. This study aims to investigate whether smoking prevalence among plastic surgery patients paralleled the national trend and whether smoking was an independent risk factor for postoperative complications.

METHODS

The 2005 to 2014 American College of Surgeons National Surgical Quality Improvement Program database was used to examine smoking prevalence and 30-day postoperative complications in 36,454 patients who underwent common plastic surgical procedures with extensive planes of dissection. Patients were propensity score-matched for demographics and comorbidities. Smokers were stratified by pack-years.

RESULTS

Compared to the national trend, a significantly smaller percentage of plastic surgical patients were smokers (p = 0.01), with a less dramatic decline in prevalence. Smokers had significantly increased deep incisional surgical-site infections, incisional dehiscence, and reoperation (p < 0.01 for all). However, superficial surgical-site infection rates were not significantly different (p = 0.18). Smokers with 11 or more pack-years had significantly increased deep surgical-site infection (p < 0.01) and reoperations (p < 0.01). There were no significant differences in graft/prosthesis/flap loss (p = 0.07), bleeding (p = 0.40), sepsis (p = 0.87), or venous thromboembolism (p = 0.16) rates between smokers and nonsmokers.

CONCLUSIONS

This is the first large-scale propensity score-matched database analysis isolating smoking as a risk factor for postoperative complications in plastic surgical procedures. Smoking was an independent risk factor for deep incisional surgical-site infection, incisional dehiscence, and reoperation. Interestingly, superficial surgical-site infection rates were not significantly different. The authors recommend continued judicious patient selection and preoperative smoking counseling to optimize postoperative outcomes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Cardiovascular effects of linalyl acetate in acute nicotine exposure

Backgroud

Smoking is a risk factor for cardiovascular diseases as well as pulmonary dysfunction. In particular, adolescent smoking has been reported to have a higher latent risk for cardiovascular disease. Despite the risk to and vulnerability of adolescents to smoking, the mechanisms underlying the effects of acute nicotine exposure on adolescents remain unknown. This study therefore evaluated the mechanism underlying the effects of linalyl acetate on cardiovascular changes in adolescent rats with acute nicotine exposure.

Methods

Parameters analyzed included heart rate (HR), systolic blood pressure, lactate dehydrogenase (LDH) activity, vascular contractility, and nitric oxide levels.

Results

Compared with nicotine alone, those treated with nicotine plus 10 mg/kg (p = 0.036) and 100 mg/kg (p = 0.023) linalyl acetate showed significant reductions in HR. Moreover, the addition of 1 mg/kg (p = 0.011), 10 mg/kg (p = 0.010), and 100 mg/kg (p = 0.011) linalyl acetate to nicotine resulted in significantly lower LDH activity. Nicotine also showed a slight relaxation effect, followed by a sustained recontraction phase, whereas nicotine plus linalyl acetate or nifedipine showed a constant relaxation effect on contraction of mouse aorta (p < 0.001). Furthermore, nicotine-induced increases in nitrite levels were decreased by treatment with linalyl acetate (p < 0.001).

Conclusions

Taken together, our findings suggest that linalyl acetate treatment resulted in recovery of cell damage and cardiovascular changes caused by acute nicotine-induced cardiovascular disruption. Our evaluation of the influence of acute nicotine provides potential insights into the effects of environmental tobacco smoke and suggests linalyl acetate as an available mitigating agent.

Upper-extremity Deep Vein Thrombosis Complicating Apheresis in a Healthy Donor

Venous thrombus was recognized in the upper extremity of a 53-year-old man after blood donation. The patient presented with a 15-day history of swelling in the left upper-extremity that started 6 hours after apheresis. Contrast-enhanced computed tomography revealed clots in the deep veins of the left arm and the peripheral pulmonary artery. Blood donation had proceeded smoothly, and the patient had no thrombotic predisposition, except for a smoking habit. The thrombus resolved following anticoagulant therapy, and the patient' s clinical course was uncomplicated. Despite a thorough investigation, the cause of this thrombus remains unknown.

A decade of e-cigarettes: Limited research & unresolved safety concerns

It is well known that tobacco consumption is a leading cause of preventable deaths worldwide and has been linked to major diseases ranging from cancer to chronic obstructive pulmonary disease, atherosclerosis, stroke and a host of neurological/neurodegenerative disorders. In the past decade a number of alternative vaping products have hit the market, rapidly gaining consumers especially among the younger population. Electronic nicotine delivery systems or e-cigarettes have become the sought-after product due to the belief that they are much safer than traditional cigarettes. However, inadequate research and lack of regulatory guidelines for both the manufacturing process and the content of the vaping solution of the e-cigarette has become a major concern. Highly debated and unresolved questions such as whether e-cigarettes may help smokers quit and whether e-cigarettes will promote the use of nicotine among non-smokers add to the confusion of the safety of e-cigarettes. In this review article, we summarize the current understanding (and lack thereof) of the potential health impacts of e-cigarettes. We will also highlight the most recent studies (in vivo/in vitro) which seem to conflict with the broad safety claims put forward by the manufacturers. Finally, we provide potential solutions to overcome the research gap of the short and long-term health impact of e-cigarettes.

Protection from cigarette smoke-induced vascular injury by recombinant human relaxin-2 (serelaxin)

Smoking is regarded as a major risk factor for the development of cardiovascular diseases (CVD). This study investigates whether serelaxin (RLX, recombinant human relaxin-2) endowed with promising therapeutic properties in CVD, can be credited of a protective effect against cigarette smoke (CS)-induced vascular damage and dysfunction. Guinea pigs exposed daily to CS for 8 weeks were treated with vehicle or RLX, delivered by osmotic pumps at daily doses of 1 or 10 μg. Controls were non-smoking animals. Other studies were performed on primary guinea pig aortic endothelial (GPAE) cells, challenged with CS extracts (CSE) in the absence and presence of 100 ng/ml (17 nmol/l) RLX. In aortic specimens from CS-exposed guinea pigs, both the contractile and the relaxant responses to phenylephrine and acetylcholine, respectively, were significantly reduced in amplitude and delayed, in keeping with the observed adverse remodelling of the aortic wall, endothelial injury and endothelial nitric oxide synthase (eNOS) down-regulation. RLX at both doses maintained the aortic contractile and relaxant responses to a control-like pattern and counteracted aortic wall remodelling and endothelial derangement. The experiments with GPAE cells showed that CSE significantly decreased cell viability and eNOS expression and promoted apoptosis by sparkling oxygen free radical-related cytotoxicity, while RLX counterbalanced the adverse effects of CSE. These findings demonstrate that RLX is capable of counteracting CS-mediated vascular damage and dysfunction by reducing oxidative stress, thus adding a tile to the growing mosaic of the beneficial effects of RLX in CVD.

Endothelial Nitric Oxide Synthase T-786C Mutation, Prothrombin Gene Mutation (G-20210-A) and Protein S Deficiency Could Lead to Myocardial Infarction in a Very Young Male Adult

INTRODUCTION:

Myocardial infarction is a rare medical event in young people. The main reasons include congenital coronary abnormalities, coronary artery spasm, and coronary thrombosis due to hypercoagulable states (hereditary and acquired).

AIM:

We present a case of a young male adult with myocardial infarction caused by a combination of gene mutations and anticoagulation protein deficiency.

CASE PRESENTATION:

A 19 years old young man was admitted to our hospital complaining of chest pain during the last two weeks. The patient did not have any known cardiovascular risk factors, except a positive family anamnesis. Subacute inferior nonST segment myocardial infarction was diagnosed according to the patient’s history, electrocardiographic and laboratory findings. Coronary angiography revealed suboclusive thrombus in the proximal, medial and distal part of the right coronary artery (TIMI 2). Percutaneous coronary intervention was performed. Anticoagulant and antiagregant therapy (heparin, acetilsalicilic acid and clopidogrel) according to protocol was started. The hospital stay was uneventful. Homozygous endothelial nitric oxid synthase (eNOS) T-786-C mutation, heterozygote prothrombin gene mutation (G-20210-A), and protein S deficiency were verified from the thrombophilia testing. Other trombophilic tests were normal. Three months after discharge from hospital another coronary angiography was performed. It revealed normal coronary arteries. Four years after the attack, the patient is free of symptoms and another cardiovascular event.

CONCLUSION:

Combination of genetic mutations and anticoagulation protein deficiency could be a reasonable cause for myocardial infarction in a very young male adult without any other cardiovascular risk factors.

The protective effect of melatonin on smoke-induced vascular injury in rats and humans: a randomized controlled trial

Smoking is one of the most harmful lifestyles in the world. Very few studies have investigated the effects of melatonin in smoke-induced vascular injury. This study was designed to investigate whether melatonin could protect rats and humans from smoke-induced vascular injury. 32 male rats and a double-blind randomized controlled trial (RCT) containing 63 participants formed the subjects of this study. In rats, 10 mg/kg of melatonin was intraperitoneally injected. Blood samples and abdominal artery were harvested two weeks later. Melatonin decreased the expression of platelet endothelial cell adhesion molecule-1 (CD31), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and endothelin-1 (ET-1) compared with the smoke exposed group (P < 0.05), whereas endothelial nitric oxide synthase (eNOS), nuclear erythroid 2-related factor 2 (Nrf2), NAD(P)H quinone oxidoreductase 1 (NQO-1), catalytic glutamate cysteine ligase (GCLC) and heme oxygenase-1 (HO-1) recovered markedly (P < 0.05). In humans, 3 mg/day of melatonin was taken orally by the participants. Blood samples were drawn at baseline and after two weeks of treatment. Compared with the oral placebo group, melatonin decreased the concentration of fibrinogen (Fbg) (P = 0.04) and free fatty acids (FFA) (P = 0.04) in smokers, along with the decreased expression of ICAM-1, VCAM-1 and ET-1 (P = 0.004, P = 0.001, P < 0.0001, respectively). In contrast, Nrf2 and HO-1 expression were markedly increased (P = 0.0001, P = 0.0049, respectively) after smokers took melatonin orally. In summary, our present data suggest that melatonin could ameliorate smoke-induced vascular injury.

Recent Marijuana Use and Associations With Exhaled Nitric Oxide and Pulmonary Function in Adults in the United States

BACKGROUND

The medical and recreational use of marijuana is now legal in some parts of the United States; the health effects are unknown. We aimed to evaluate associations between recent marijuana use and exhaled nitric oxide (eNO) and pulmonary function.

METHODS

We performed a cross-sectional study of 10,327 US adults participating in the National Health and Nutrition Examination Survey in the years 2007 to 2012. We examined associations between marijuana use and eNO, FEV1, FVC, the FEV1/FVC ratio, and forced expiratory flow (midexpiratory phase) (FEF25%-75%) by weighted linear regression.

RESULTS

In the study population, there were 4,797 never users, 4,084 past marijuana users, 555 participants who used marijuana 5 to 30 days before the examination, and 891 participants who used marijuana 0 to 4 days before the examination. Current marijuana use in the past 4 days was associated with 13% lower eNO (95% CI, -18% to 8%). FVC was higher in past users (75 mL; 95% CI, 38-112) and current users in the past 5 to 30 days (159 mL; 95% CI, 80-237) and in users within 0 to 4 days of the examination (204 mL; 95% CI, 139-270) compared with never users. All associations remained unchanged and statistically significant in sensitivity analyses excluding current and past tobacco users.

CONCLUSIONS

Current marijuana use was associated with lower levels of eNO and higher FVC. The lower eNO in marijuana smokers suggests that short-term exposure to marijuana may, like tobacco, acutely affect the pulmonary vascular endothelium and impair airflow through the small airways.

Association between smoking and the risk of acute mountain sickness: a meta-analysis of observational studies

BACKGROUND

People rapidly ascending to high altitudes (>2500 m) may suffer from acute mountain sickness (AMS). The association between smoking and AMS risk remains unclear. Therefore, we performed a meta-analysis to evaluate the association between smoking and AMS risk.

METHODS

The association between smoking and AMS risk was determined according to predefined criteria established by our team. Meta-analysis was conducted according to the PRISMA guidelines. We included all relevant studies listed in the PubMed and Embase databases as of September 2015 in this meta-analysis and performed systemic searches using the terms "smoking", "acute mountain sickness" and "risk factor". The included studies were required to provide clear explanations regarding their definitions of smoking, the final altitudes reached by their participants and the diagnostic criteria used to diagnose AMS. Odds ratios (ORs) were used to evaluate the association between smoking and AMS risk across the studies, and the Q statistic was used to test OR heterogeneity, which was considered significant when P < 0.05. We also computed 95% confidence intervals (CIs). Data extracted from the articles were analyzed with Review Manager 5.3 (Cochrane Collaboration, Oxford, UK).

RESULTS

We used seven case-control studies including 694 smoking patients and 1986 non-smoking controls to analyze the association between smoking and AMS risk. We observed a significant association between AMS and smoking (OR = 0.71, 95% CI 0.52-0.96, P = 0.03).

CONCLUSIONS

We determined that smoking may protect against AMS development. However, we do not advise smoking to prevent AMS. More studies are necessary to confirm the role of smoking in AMS risk.

Protection of coronary endothelial cells from cigarette smoke-induced oxidative stress by a new Mn(II)-containing polyamine-polycarboxilate scavenger of superoxide anion

Oxidative stress plays a major role in cardiovascular injury and dysfunction induced by cigarette smoke. Smoke-borne pro-oxidants impair endothelial function and predispose to thrombosis, inflammation and atherosclerosis. This in vitro study evaluates whether Mn(II)(4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diacetate).2H2O (Mn(II)(Me2DO2A)), a polyamine-polycarboxilate, Mn(II)-containing O2(-) scavenger, has a direct protective action on guinea pig coronary endothelial (GPCE) cells exposed to cigarette smoke extracts (CSE). Mn(II)(Me2DO2A) (1-10μmol/l) was added to the culture medium together with CSE and maintained for 4h. In parallel experiments, the inactive congener Zn(II)(Me2DO2A), in which Zn(II) replaced the functional Mn(II) center in the same organic scaffold, was used as negative control. Mn(II)(Me2DO2A), mostly at the higher doses (5 and 10μmol/l), significantly increased GPCE cell viability (trypan blue assay), improved mitochondrial activity (MTT test, mitochondrial membrane potential Δψ), reduced cellular apoptosis (mPTP, caspase-3 activity, TUNEL assay), decreased intracellular ROS levels (H2DCFDA), lipoperoxidation (BODIPY 581/591) and decreased protein nitrosylation. Of note, Zn(II)(Me2DO2A) did not preserve cell viability. These findings suggest that Mn(II)(Me2DO2A) is a promising O2(-) scavenging compound able to protect from cigarette smoke-induced oxidative cell injury. In perspective, should its efficacy be confirmed in future in vivo studies, this molecule might represent a therapeutic or preventive drug to counteract cigarette smoke toxicity.

Early physiological markers of cardiovascular risk in community based adolescents with a depressive disorder

BACKGROUND

Depression is recognised as an independent cardiovascular risk factor in adults. Identifying this relationship early on in life is potentially important for the prevention of cardiovascular disease (CVD). This study investigated whether clinical depression is associated with multiple physiological markers of CVD risk in adolescents from the general community.

METHODS

Participants aged 12-18 years were recruited from the general community and screened for depressive symptoms. Individuals with high and low depressive symptoms were administered a diagnostic interview. Fifty participants, 25 with a current depressive episode and 25 matched healthy controls, subsequently completed cardiovascular assessments. Variables assessed were automatic brachial and continuous beat-to-beat finger arterial blood pressure, heart rate, vascular functioning by pulse amplitude tonometry following reactive hyperaemia and pulse transit time (PTT) at rest. Blood samples were collected to measure cholesterol, glucose and glycohaemoglobin levels and an index of cumulative risk of traditional cardiovascular risk factors was calculated.

RESULTS

Depressed adolescents had a significantly lower reactive hyperaemia index and shorter PTT, suggesting deterioration in vascular integrity and structure. Higher fasting glucose and triglyceride levels were also observed in the depressed group, who also had higher cumulative risk scores indicative of increased engagement in unhealthy behaviours and higher probability of advanced atherosclerotic lesions.

LIMITATIONS

The sample size and number of males who completed all cardiovascular measures was small.

CONCLUSIONS

Clinically depressed adolescents had poorer vascular functioning and increased CVD risk compared to controls, highlighting the need for early identification and intervention for the prevention of CVD in depressed youth.

Recent advances in research on nitrergic nerve-mediated vasodilatation

Cerebral vascular resistance and blood flow were widely considered to be regulated solely by tonic innervation of vasoconstrictor adrenergic nerves. However, pieces of evidence suggesting that parasympathetic nitrergic nerve activation elicits vasodilatation in dog and monkey cerebral arteries were found in 1990. Nitric oxide (NO) as a neurotransmitter liberated from parasympathetic postganglionic neurons decreases cerebral vascular tone and resistance and increases cerebral blood flow, which overcome vasoconstrictor responses to norepinephrine liberated from adrenergic nerves. Functional roles of nitrergic vasodilator nerves are found also in peripheral vasculature, including pulmonary, renal, mesenteric, hepatic, ocular, uterine, nasal, skeletal muscle, and cutaneous arteries and veins; however, adrenergic nerve-induced vasoconstriction is evidently greater than nitrergic vasodilatation in these vasculatures. In coronary arteries, neurogenic NO-mediated vasodilatation is not clearly noted; however, vasodilatation is induced by norepinephrine released from adrenergic nerves that activates β1-adrenoceptors. Impaired actions of NO liberated from the endothelium and nitrergic neurons are suggested to participate in cerebral hypoperfusion, leading to brain dysfunction, like that in Alzheimer's disease. Nitrergic neural dysfunction participates in impaired circulation in peripheral organs and tissues and also in systemic blood pressure increase. NO and vasodilator peptides, as sensory neuromediators, are involved in neurogenic vasodilatation in the skin. Functioning of nitrergic vasodilator nerves is evidenced not only in a variety of mammals, including humans and monkeys, but also in non-mammals. The present review article includes recent advances in research on the functional importance of nitrergic nerves concerning the control of cerebral blood flow, as well as other regions, and vascular resistance. Although information is still insufficient, the nitrergic nerve histology and function in vasculatures of non-mammals are also summarized.

PI3K/Akt-independent NOS/HO activation accounts for the facilitatory effect of nicotine on acetylcholine renal vasodilations: modulation by ovarian hormones

We investigated the effect of chronic nicotine on cholinergically-mediated renal vasodilations in female rats and its modulation by the nitric oxide synthase (NOS)/heme oxygenase (HO) pathways. Dose-vasodilatory response curves of acetylcholine (0.01–2.43 nmol) were established in isolated phenylephrine-preconstricted perfused kidneys obtained from rats treated with or without nicotine (0.5–4.0 mg/kg/day, 2 weeks). Acetylcholine vasodilations were potentiated by low nicotine doses (0.5 and 1 mg/kg/day) in contrast to no effect for higher doses (2 and 4 mg/kg/day). The facilitatory effect of nicotine was acetylcholine specific because it was not observed with other vasodilators such as 5′-N-ethylcarboxamidoadenosine (NECA, adenosine receptor agonist) or papaverine. Increases in NOS and HO-1 activities appear to mediate the nicotine-evoked enhancement of acetylcholine vasodilation because the latter was compromised after pharmacologic inhibition of NOS (L-NAME) or HO-1 (zinc protoporphyrin, ZnPP). The renal protein expression of phosphorylated Akt was not affected by nicotine. We also show that the presence of the two ovarian hormones is necessary for the nicotine augmentation of acetylcholine vasodilations to manifest because nicotine facilitation was lost in kidneys of ovariectomized (OVX) and restored after combined, but not individual, supplementation with medroxyprogesterone acetate (MPA) and estrogen (E2). Together, the data suggests that chronic nicotine potentiates acetylcholine renal vasodilation in female rats via, at least partly, Akt-independent HO-1 upregulation. The facilitatory effect of nicotine is dose dependent and requires the presence of the two ovarian hormones.

Effect of co-administration of morphine and nicotine on cardiovascular function in two-kidney one clip hypertensive (2K1C) rats

Cardiovascular morbidity and mortality are potentiated with smoking and hypertension. The aim of this study was to investigate the effects of morphine and nicotine co-administration on cardiovascular function in two-kidney one-clip hypertensive (2K1C) rats. Thirty-two male rats were divided into four groups as follow: Vehicle, morphine, nicotine and nicotine + morphine. All drugs were administered for 8 weeks. Baroreflex sensitivity (BRS), heart rate and blood pressure were measured using a Power Lab data acquisition. Plasma rennin activity (PRA) and serum concentration of nitric oxide (NO) were measured using Elisa method. To induce hypertension, the renal artery of left kidney was clipped for 8 weeks. A significant decrease in systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) was observed in nicotine + morphine group compared to vehicle and nicotine groups (p<0.05). Serum concentration of NO was lower in nicotine + morphine group compared to morphine group and significantly higher than nicotine group. The BRS was lower in the nicotine + morphine group compared to other groups. The PRA level was higher in nicotine + morphine compared to morphine group but it was higher than nicotine group. This study demonstrated that prolonged co-consumption of morphine and nicotinedecreased PRA and blood pressure and increased the serum concentration of NO in hypertensive rats. Co-administration of morphine and nicotine decreased BRS in 2k1c hypertensive rats probably via central nervous system.

ARB affects nicotine-induced gene expression profile in human coronary artery endothelial cells

AIM: To investigate the effects of nicotine and nicotine plus angiotensin II receptor blocker (ARB) on the gene expression profile of human coronary artery endothelial cells (HCAECs).

METHODS: The changes in gene expression profiles in HCAECs treated with nicotine and nicotine plus ARB olmesartan were analyzed by DNA microarray. In nicotine-treated HCAECs, 432 genes selected by P < 0.01 were greater than 1.5-fold compared with the untreated cells. Data were analyzed using IPA (Ingenuity^® Systems, www.ingenuity.com).

RESULTS: The gene expression levels of tumor necrosis factor-α, collagen type 1, matrix metalloproteinase-10, and disintegrin and metalloprotease domain 8, which are related to “cardiovascular function and disease”, were significantly increased. In canonical pathway analyses using IPA, “atherosclerosis signaling” was strongly affected by nicotine treatment and this effect was reduced by co-incubation with ARB olmesartan. These data indicate that the deleterious cardiovascular consequences of cigarette smoking may, at least in part, be due to the nicotine-induced gene expression profile related to “atherosclerosis signaling”.

CONCLUSION: The inhibitory effect of ARB against the nicotine-induced gene expression profile may possibly induce anti-atherosclerotic effects that are independent of those from lowering the blood pressure.