Nicotine treatment for ulcerative colitis

Electronic hookah (waterpipe) vaping reduces vascular endothelial function: the role of nicotine

Vaping has risen substantially in recent years, particularly among young adults. Electronic (e-) hookahs are a newer category of vaping devices touted as safer tobacco alternatives. Although e-hookah vaping acutely reduces endothelial function, the role of nicotine and the mechanisms by which it may impair endothelial function remain understudied. In a randomized crossover study, we investigated the acute effects of vaping e-hookah, with and without nicotine, as compared with sham on endothelial function assessed by brachial artery flow-mediated dilation (FMD), among 18 overtly healthy young adults. To determine the role of changes in circulating factors in plasma on endothelial cell function, human umbilical vein endothelial cells (HUVECs) were cultured with participants' plasma, and acetylcholine-stimulated nitric oxide (NO) production and basal reactive oxygen species (ROS) bioactivity were assessed. Plasma nicotine was measured before and after the sessions. E-hookah vaping with nicotine, which acutely increased heart rate (HR) by 8 ± 3 beats/min and mean arterial pressure (MAP) by 7 ± 2 mmHg (means ± SE; P < 0.05), decreased endothelial-dependent FMD by 1.57 ± 0.19%Δ (P = 0.001), indicating impairment in endothelial function. Vaping e-hookah without nicotine, which mildly increased hemodynamics (HR, 2 ± 2 beats/min and MAP 1 ± 1 mmHg; P = ns), did not significantly impair endothelial function. No changes were observed after sham vaping. HUVECs cultured with participants' plasma after versus before e-hookah vaping with nicotine, but not without nicotine or sham vaping, exhibited reductions in endothelial cell NO bioavailability and increases in ROS bioactivity (P < 0.05). Plasma nicotine concentrations increased after vaping e-hookah with nicotine (6.7 ± 1.8 ng/mL; P = 0.002), whereas no changes were observed after vaping e-hookah without nicotine or sham (P = ns). Acute e-hookah vaping induces endothelial dysfunction by impairing NO bioavailability associated with increased ROS production, and these effects are attributable to nicotine, not to nonnicotine constituents, present in the flavored e-liquid.NEW & NOTEWORTHY Despite safety claims heavily advertised by the hookah tobacco industry, acute e-hookah vaping induces in vivo endothelial dysfunction by impairing ex vivo NO bioavailability associated with increased ROS production. These effects are attributable to nicotine, not to nonnicotine constituents, present in the flavored e-liquid.

Conception and reality: Outcome of SARS-CoV-2 infection and vaccination among Hungarian IBD patients on biologic treatments

Introduction

Inflammatory bowel disease potentially elevates the risk of infections, independently from age, while the disease activity and medical treatment(s) can also increase the risks. Nevertheless, it is necessary to clarify these preconceptions as well during the COVID-19 pandemic.

Methods

An observational, questionnaire based study was conducted in Hungary between February and August 2021. 2 questionnaires were completed. The first questionnaire surveyed the impact of the pandemic on patients with biologic treatments and assessed the severity and outcome of the infection, whereas the second one assessed vaccination rate and adverse events.

Results

472 patients participated in the study. 16.9 % of them acquired the infection and 6.3 % needed hospitalization. None of them required ICU care. Male sex elevated the risk of infection (p = 0.008), while glove (p = 0.02) and mask wearing (p = 0.005) was the most effective prevention strategy. Nevertheless, abstaining from community visits or workplace did not have an impact on the infection rate. Smoking, age, and disease type did not elevate the risk. UC patients had poorer condition during the infection (p = 0.003); furthermore, the disease activity could potentially worsen the course of infection (p = 0.072). The different biological treatments were equally safe; no difference was observed in the infection rate, course of COVID-19. Azathioprine and corticosteroids did not elevate the infection rate. 28 patients (35.0 %) suspended the ongoing biologic treatment, but it had no impact on the disease course. However, it resulted in changing the current treatment (p = 0.004). 9.8 % of the respondents were sceptic about being vaccinated, and 90 % got vaccinated. In one case, a serious flare-up occurred.

Discussion

Most patients acquired the infection at workplace. Biologic therapies had no effect on the COVID-19 infection, whereas male sex, an active disease, and UC could be larger threat than treatments. Vaccination was proved to be safe, and patient education is important to achieve mass vaccination of the population.

Evolving Experimental Platforms to Evaluate Ulcerative Colitis

Ulcerative colitis (UC) is a multifactorial disease defined by chronic intestinal inflammation with idiopathic origins. It has a predilection to affect the mucosal lining of the large intestines and rectum. Management of UC depends upon numerous factors that include disease pathogenesis and severity that are maintained via medical or surgical means. Chronic inflammation that is left untreated or managed poorly from a clinical stance can result in intestinal ulceration accompanied by resulting physiological dysfunction. End-stage UC is mediated by surgical intervention with the resection of diseased tissue. This can lead to numerous health-related quality of life issues but is considered a curative approach. Regimens to treat UC are ever evolving and find their basis within various platforms to evaluate and treat UC. Numerous modeling systems have been examined to delineate potential mechanisms of action. However, UC is a heterogenous disease spanning unknown genetic origins coupled with environmental factors that can influence disease outcomes and related treatment procedures. Unfortunately, there is no one-size-fits-all model to fully assess all facets of UC. Within the context of this review article, the utility of various approaches that have been employed to gain insight into different aspects of UC will be investigated.

Medicinal nicotine in COVID-19 acute respiratory distress syndrome, the new corticosteroid

The cholinergic anti-inflammatory pathway (CAP) refers to the anti-inflammatory effects mediated by the parasympathetic nervous system. Existence of this pathway was first demonstrated when acetylcholinesterase inhibitors showed benefits in animal models of sepsis. CAP functions via the vagus nerve. The systemic anti-inflammatory effects of CAP converges on the α7 nicotinic acetylcholine receptor on splenic macrophages, leading to suppression of pro-inflammatory cytokines and simultaneous stimulation of anti-inflammatory cytokines, including interleukin 10. CAP offers a novel mechanism to mitigate inflammation. Electrical vagal nerve stimulation has shown benefits in patients suffering from rheumatoid arthritis. Direct agonists like nicotine and GTS-1 have also demonstrated anti-inflammatory properties in models of sepsis and acute respiratory distress syndrome, as have acetylcholinesterase inhibitors like Galantamine and Physostigmine. Experience with coronavirus disease 2019 (COVID-19) induced acute respiratory distress syndrome indicates that immunomodulators have a protective role in patient outcomes. Dexamethasone is the only medication currently in use that has shown to improve clinical outcomes. This is likely due to the suppression of what is referred to as a cytokine storm, which is implicated in the lethality of viral pneumonia. Nicotine transdermal patch activates CAP and harvests its anti-inflammatory potential by means of an easily administered depot delivery mechanism. It could prove to be a promising, safe and inexpensive additional tool in the currently limited armamentarium at our disposal for management of COVID-19 induced acute hypoxic respiratory failure.

The Relationship between Smoking, Raynaud's Phenomenon, Digital Ulcers, and Skin Thickness in the Waikato Systemic Sclerosis Cohort

OBJECTIVES

Systemic sclerosis (SSc) is a heterogeneous complex autoimmune connective tissue disease with variable presentation as a consequence of multisystem involvement. One of the key features of SSc is Raynaud's phenomenon along with vascular endothelial dysfunction that leads to digital ulcers (DUs). Raynaud's tends to be triggered by decreasing thermal gradient exposure, while stress and smoking also play a role. DUs arising as a consequence of severe Raynaud's and vasculopathy are a major cause of morbidity and disability in SSc. We set out to determine the relationship between smoking, Raynaud's phenomenon, DUs, and skin thickness in our Waikato Systemic Sclerosis cohort.

METHODS

The Waikato Systemic Sclerosis (SSc) database was used to extract data. Variables collected included demographics, age of diagnosis, SSc subtypes, age at first non-Raynaud's phenomenon, medications used for treatment of Raynaud's phenomenon or ulcers, and maximal modified Rodnan skin score (mRSS). Raynaud's phenomenon and finger DUs (severity for each over the past week and since diagnosis) and a Scleroderma Health Assessment Questionnaire (SHAQ) visual analog 10 cm scale were collected. The lead rheumatologist completed a physician's assessment of Raynaud's and the disease severity questionnaire.

RESULTS

Of the cohort of 143 patients, 100 patients were eligible to complete the questionnaires. Seventy-five patients returned completed questionnaires. Of these, the majority were female (88%), 52 (69.3%) had limited cutaneous systemic sclerosis (lcSSc), 17 (22.7%) had diffuse cutaneous systemic sclerosis (dcSSc), and 6 (8%) had an overlap syndrome. Thirty-six (48%) had a smoking history (in the time frame of collection of serial data). Mean ± standard deviation (SD) pack-years smoked were 17.11 ± 15.29 years. Thirty-five participants had a history of DUs, with a median of 4 DU (range 1-20). Of 17 patients with dcSSc, 12 (70.6%) had ulcers in comparison with 17 of 52 (32.7%) patients with lcSSc. There was a significant relationship between SSc subtype and the number with ulcers (X² = 10.1, P = 0.007). There was also a significant relationship between physician severity of Raynaud's and presence of ulcers (t = 6.1, P < 0.001), which was not evident between patients' severity of Raynaud's and presence of ulcers (t = 1.9, P = 0.06). On the SHAQ score, smokers had significantly worse Raynaud's phenomenon over the prior week (t = 3.08, P = 0.03) and were more likely to note DUs over the preceding week, although the latter was not statistically significant (t = 1.95, P = 0.055). There was no association between smoking and skin thickness as measured by mRSS (r = 0.23, P = 0.19).

CONCLUSION

Our study demonstrates that smokers have had worse Raynaud's phenomenon over the past week and they were also more likely to note DUs with a trend toward significance but not statistically significant most likely due to our small sample size. Our study also demonstrated that patients with dcSSc had more ulcers in comparison with lcSSc. This study justifies physicians strongly recommending smoking cessation in patients with SSc.

Ectoines as novel anti-inflammatory and tissue protective lead compounds with special focus on inflammatory bowel disease and lung inflammation

The compatible solute ectoine is one of the most abundant and powerful cytoprotectant in the microbial world. Due to its unique ability to stabilize biological membranes and macromolecules it has been successfully commercialized as ingredient of various over-the-counter drugs, achieving primarily epithelial protection. While trying to elucidate the mechanism of its cell protective properties in in-vitro studies, a significant anti-inflammatory effect was documented for the small molecule. The tissue protective potential of ectoine considerably improved organ quality during preservation. In addition, ectoine and derivatives have been demonstrated to significantly decrease inflammatory cytokine production, thereby alleviating the inflammatory response following organ transplantation, and launching new therapeutic options for pathologies such as Inflammatory Bowel Disease (IBD) and Chronic Obstructive Pulmonary Disease (COPD). In this review, we aim to summarize the knowledge of this fairly nascent field of the anti-inflammatory potential of diverse ectoines. We also point out that this promising field faces challenges in its biochemical and molecular substantiations, including defining the molecular mechanisms of the observed effects and their regulation. However, based on their potent cytoprotective, anti-inflammatory, and non-toxic properties we believe that ectoines represent promising candidates for risk free interventions in inflammatory pathologies with steeply increasing demands for new therapeutics.

Effects of tobacco cigarettes, e-cigarettes, and waterpipe smoking on endothelial function and clinical outcomes

Tobacco smoking is a leading cause of non-communicable disease globally and is a major risk factor for cardiovascular disease (CVD) and lung disease. Importantly, recent data by the World Health Organizations (WHO) indicate that in the last two decades global tobacco use has significantly dropped, which was largely driven by decreased numbers of female smokers. Despite such advances, the use of e-cigarettes and waterpipes (shisha, hookah, narghile) is an emerging trend, especially among younger generations. There is growing body of evidence that e-cigarettes are not a harm-free alternative to tobacco cigarettes and there is considerable debate as to whether e-cigarettes are saving smokers or generating new addicts. Here, we provide an updated overview of the impact of tobacco/waterpipe (shisha) smoking and e-cigarette vaping on endothelial function, a biomarker for early, subclinical, atherosclerosis from human and animal studies. Also their emerging adverse effects on the proteome, transcriptome, epigenome, microbiome, and the circadian clock are summarized. We briefly discuss heat-not-burn tobacco products and their cardiovascular health effects. We discuss the impact of the toxic constituents of these products on endothelial function and subsequent CVD and we also provide an update on current recommendations, regulation and advertising with focus on the USA and Europe. As outlined by the WHO, tobacco cigarette, waterpipe, and e-cigarette smoking/vaping may contribute to an increased burden of symptoms due to coronavirus disease 2019 (COVID-19) and to severe health consequences.

Transdermal Nicotine as a Treatment Option for Ulcerative Colitis: A Review

Ulcerative colitis (UC) is primarily a disease of non-smokers or ex-smokers. Since there have been previous claims of the beneficial effects of transdermal nicotine, researchers studied its efficacy to include it in the treatment regimen: to prevent remissions and as maintenance therapy. This review aims to evaluate the efficacy of transdermal nicotine as a treatment option for mild to moderately active ulcerative colitis. We shortlisted 22 articles after a careful analysis and elimination process. These articles were reviewed and analyzed, and it was found that transdermal nicotine in combination with conventional therapy was more beneficial than individual treatment with either. Further controlled studies evaluating the appropriate dosage for remission and maintenance treatment needs to be done.

Risk of severe COVID-19 disease with ACE inhibitors and angiotensin receptor blockers: cohort study including 8.3 million people

BACKGROUND

There is uncertainty about the associations of angiotensive enzyme (ACE) inhibitor and angiotensin receptor blocker (ARB) drugs with COVID-19 disease. We studied whether patients prescribed these drugs had altered risks of contracting severe COVID-19 disease and receiving associated intensive care unit (ICU) admission.

METHODS

This was a prospective cohort study using routinely collected data from 1205 general practices in England with 8.28 million participants aged 20-99 years. We used Cox proportional hazards models to derive adjusted HRs for exposure to ACE inhibitor and ARB drugs adjusted for sociodemographic factors, concurrent medications and geographical region. The primary outcomes were: (a) COVID-19 RT-PCR diagnosed disease and (b) COVID-19 disease resulting in ICU care.

FINDINGS

Of 19 486 patients who had COVID-19 disease, 1286 received ICU care. ACE inhibitors were associated with a significantly reduced risk of COVID-19 disease (adjusted HR 0.71, 95% CI 0.67 to 0.74) but no increased risk of ICU care (adjusted HR 0.89, 95% CI 0.75 to 1.06) after adjusting for a wide range of confounders. Adjusted HRs for ARBs were 0.63 (95% CI 0.59 to 0.67) for COVID-19 disease and 1.02 (95% CI 0.83 to 1.25) for ICU care.There were significant interactions between ethnicity and ACE inhibitors and ARBs for COVID-19 disease. The risk of COVID-19 disease associated with ACE inhibitors was higher in Caribbean (adjusted HR 1.05, 95% CI 0.87 to 1.28) and Black African (adjusted HR 1.31, 95% CI 1.08 to 1.59) groups than the white group (adjusted HR 0.66, 95% CI 0.63 to 0.70). A higher risk of COVID-19 with ARBs was seen for Black African (adjusted HR 1.24, 95% CI 0.99 to 1.58) than the white (adjusted HR 0.56, 95% CI 0.52 to 0.62) group.

INTERPRETATION

ACE inhibitors and ARBs are associated with reduced risks of COVID-19 disease after adjusting for a wide range of variables. Neither ACE inhibitors nor ARBs are associated with significantly increased risks of receiving ICU care. Variations between different ethnic groups raise the possibility of ethnic-specific effects of ACE inhibitors/ARBs on COVID-19 disease susceptibility and severity which deserves further study.

The Gateway Reflex, a Novel Neuro-Immune Interaction for the Regulation of Regional Vessels

The gateway reflex is a new phenomenon that explains how immune cells bypass the blood-brain barrier to infiltrate the central nervous system (CNS) and trigger neuroinflammation. To date, four examples of gateway reflexes have been discovered, each described by the stimulus that evokes the reflex. Gravity, electricity, pain, and stress have all been found to create gateways at specific regions of the CNS. The gateway reflex, the most recently discovered of the four, has also been shown to upset the homeostasis of organs in the periphery through its action on the CNS. These reflexes provide novel therapeutic targets for the control of local neuroinflammation and organ function. Each gateway reflex is activated by different neural activations and induces inflmammation at different regions in the CNS. Therefore, it is theoretically possible to manipulate each independently, providing a novel therapeutic strategy to control local neuroinflammation and peripheral organ homeostasis.

Neural inhibition of inflammation: the cholinergic anti-inflammatory pathway

The innate immune system is activated by infection and injury to release pro-inflammatory cytokines, which activate macrophages and neutrophils and modulate specific cellular responses. The magnitude of the cytokine response is critical, because a deficient response may result in secondary infections, while an excessive response may be more injurious than the original insult. We recently described a neural pathway, termed the `cholinergic anti-inflammatory pathway', that reflexively monitors and adjusts the inflammatory response by inhibiting pro-inflammatory cytokine synthesis. Efferent signals in the vagus nerve provide a direct mechanism for neural regulation of the immune response that is rapid, localized, and integrated. Vagus nerve stimulation inhibits the release of TNF, HMGB1, and other cytokines, and protects against endotoxemia and ischemia-reperfusion injury. This newly identified physiological mechanism of maintaining immunological homeostasis suggests that novel therapeutics may effectively modulate inflammatory responses by activating the cholinergic anti-inflammatory pathway.

Transdermal Nicotine Application Attenuates Cardiac Dysfunction after Severe Thermal Injury

Background. Severe burn trauma leads to an immediate and strong inflammatory response inciting cardiac dysfunction that is associated with high morbidity and mortality. The aim of this study was to determine whether transdermal application of nicotine could influence the burn-induced cardiac dysfunction via its known immunomodulatory effects. Material and Methods. A standardized rat burn model was used in 35 male Sprague Dawley rats. The experimental animals were divided into a control group, a burn trauma group, a burn trauma group with additional nicotine treatment, and a sham group with five experimental animals per group. The latter two groups received nicotine administration. Using microtip catheterization, functional parameters of the heart were assessed 12 or 24 hours after infliction of burn trauma. Results. Burn trauma led to significantly decreased blood pressure (BP) values whereas nicotine administration normalized BP. As expected, burn trauma also induced a significant deterioration of myocardial contractility and relaxation parameters. After application of nicotine these adverse effects were attenuated. Conclusion. The present study showed that transdermal nicotine administration has normalizing effects on burn-induced myocardial dysfunction parameters. Further research is warranted to gain insight in molecular mechanisms and pathways and to evaluate potential treatment options in humans.

Surgical management of ulcerative colitis in the era of biologicals

PURPOSE

Proctocolectomy has been a curative option for patients with severe ulcerative colitis. In recent years, there has been a growing use of medical salvage therapy in the management of patients with moderate to severe ulcerative colitis. We aimed at reviewing the role of surgical management in a time of intensified medical management on the basis of published trial data. The aim was to determine the efficacy of aggressive medical versus surgical management in achieving multifaceted treatment goals.

METHODS

A comprehensive search of Pubmed, Medline, the Cochrane database was performed. Abstracts were evaluated for relevance. Selected articles were then reviewed in detail, including references. Recommendations were then drafted based on evidence and conclusions in the selected articles.

RESULTS

The majority of patients with UC will not need surgery. However, steroid-refractoriness and steroid-dependence signal a subset of patients with more challenging disease. Biological therapy has been shown to achieve short-term improvement and temporarily reduce the need for a colectomy. However, there is a substantial financial and medical price to pay because a high fraction of these salvaged patients will still need a curative colectomy but may be exposed to the negative impact of prolonged immunosuppression, chronic illness, and a higher probability to require 3 rather than 2 operations. Proctocolectomy with ileo-anal pouch anastomosis-performed in 1, 2, or 3 steps depending on the patient's condition-remains the surgical procedure of choice. Even though it has its share of possible complications, it has been associated with excellent long-term outcomes and high levels of satisfaction, such that in the majority of patients they become indistinguishable from unaffected normal individuals.

CONCLUSIONS

The current data demonstrate that use of medical salvage therapy in the treatment of UC will likely continue to grow and evolve. Consensus is being developed to better define and predict failure of medical therapy and clarify the role of the different treatment modalities. For many patients, sacrificing the nonresponsive diseased colon is an underused or unnecessarily delayed chance to normalize their health and life. Biologicals in many instances may have to be considered the bridge to that end.

Inflammatory response to burn trauma: nicotine attenuates proinflammatory cytokine levels

OBJECTIVE

The immune response to an inflammatory stimulus is balanced and orchestrated by stimulatory and inhibitory factors. After a thermal trauma, this balance is disturbed and an excessive immune reaction with increased production and release of proinflammatory cytokines results. The nicotine-stimulated anti-inflammatory reflex offsets this. The goal of this study was to verify that transdermal administration of nicotine downregulates proinflammatory cytokine release after burn trauma.

METHODS

A 30% total body surface area full-thickness rat burn model was used in Sprague Dawley rats (n = 35, male). The experimental animals were divided into a control group, a burn trauma group, a burn trauma group with additional nicotine treatment, and a sham + nicotine group with 5 experimental animals per group. The last 2 groups received a transdermal nicotine administration of 1.75 mg. The concentrations of tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 were determined in homogenates of hearts, livers, and spleens 12 or 24 hours after burn trauma.

RESULTS

Experimental burn trauma resulted in a significant increase in cytokine levels in hearts, livers, and spleens. Nicotine treatment led to a decrease of the effect of the burn trauma with significantly lower concentrations of tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 compared to the trauma group.

CONCLUSIONS

This study confirms in a standardized burn model that stimulation of the nicotinic acetylcholine receptor is involved in the regulation of effectory molecules of the immune response. Looking at the results of our study, further experiments designed to explore and evaluate the potency and mechanisms of the immunomodulating effects of this receptor system are warranted.

Safety evaluation and risk assessment of electronic cigarettes as tobacco cigarette substitutes: a systematic review

Electronic cigarettes are a recent development in tobacco harm reduction. They are marketed as less harmful alternatives to smoking. Awareness and use of these devices has grown exponentially in recent years, with millions of people currently using them. This systematic review appraises existing laboratory and clinical research on the potential risks from electronic cigarette use, compared with the well-established devastating effects of smoking tobacco cigarettes. Currently available evidence indicates that electronic cigarettes are by far a less harmful alternative to smoking and significant health benefits are expected in smokers who switch from tobacco to electronic cigarettes. Research will help make electronic cigarettes more effective as smoking substitutes and will better define and further reduce residual risks from use to as low as possible, by establishing appropriate quality control and standards.

Influenza virus-induced lung inflammation was modulated by cigarette smoke exposure in mice

Although smokers have increased susceptibility and severity of seasonal influenza virus infection, there is no report about the risk of 2009 pandemic H1N1 (pdmH1N1) or avian H9N2 (H9N2/G1) virus infection in smokers. In our study, we used mouse model to investigate the effect of cigarette smoke on pdmH1N1 or H9N2 virus infection. Mice were exposed to cigarette smoke for 21 days and then infected with pdmH1N1 or H9N2 virus. Control mice were exposed to air in parallel. We found that cigarette smoke exposure alone significantly upregulated the lung inflammation. Such prior cigarette smoke exposure significantly reduced the disease severity of subsequent pdmH1N1 or H9N2 virus infection. For pdmH1N1 infection, cigarette smoke exposed mice had significantly lower mortality than the control mice, possibly due to the significantly decreased production of inflammatory cytokines and chemokines. Similarly, after H9N2 infection, cigarette smoke exposed mice displayed significantly less weight loss, which might be attributed to lower cytokines and chemokines production, less macrophages, neutrophils, CD4⁺ and CD8⁺ T cells infiltration and reduced lung damage compared to the control mice. To further investigate the underlying mechanism, we used nicotine to mimic the effect of cigarette smoke both in vitro and in vivo. Pre-treating the primary human macrophages with nicotine for 72 h significantly decreased their expression of cytokines and chemokines after pdmH1N1 or H9N2 infection. The mice subcutaneously and continuously treated with nicotine displayed significantly less weight loss and lower inflammatory response than the control mice upon pdmH1N1 or H9N2 infection. Moreover, α7 nicotinic acetylcholine receptor knockout mice had more body weight loss than wild-type mice after cigarette smoke exposure and H9N2 infection. Our study provided the first evidence that the pathogenicity of both pdmH1N1 and H9N2 viruses was alleviated in cigarette smoke exposed mice, which might partially be attributed to the immunosuppressive effect of nicotine.

The α4 nicotinic receptor promotes CD4+ T-cell proliferation and a helper T-cell immune response

Smoking is a common addiction and a leading cause of disease. Chronic nicotine exposure is known to activate nicotinic acetylcholine receptors (nAChRs) in immune cells. We demonstrate a novel role for α4 nAChRs in the effect of nicotine on T-cell proliferation and immunity. Using cell-based sorting and proteomic analysis we define an α4 nAChR expressing helper T-cell population (α4(+)CD3(+)CD4(+)) and show that this group of cells is responsive to sustained nicotine exposure. In the circulation, spleen, bone marrow, and thymus, we find that nicotine promotes an increase in CD3(+)CD4(+) cells via its activation of the α4 nAChR and regulation of G protein subunit o, G protein regulated-inducer of neurite outgrowth, and CDC42 signaling within T cells. In particular, nicotine is found to promote a helper T cell 2 adaptive immunologic response within T cells that is absent in α4(-/-) mice. We thus present a new mechanism of α4 nAChR signaling and immune regulation in T cells, possibly accounting for the effect of smoking on the immune system.

Carbachol alleviates rat cytokine release and organ dysfunction induced by lipopolysaccharide

BACKGROUND

To observe the influence of carbachol on inflammatory cytokine release and its protective role on organ function in rat endotoxemia model, and, furthermore, to investigate its receptor mechanism in rat peritoneal macrophages in vitro.

METHODS

In the animal experiments, Wistar rats were subjected to lipopolysaccharide (LPS) injection (5 mg/kg body weight) to establish an endotoxemia animal model, and carbachol/nicotine was given 15 minutes after LPS injection. Serum contents of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 were determined with enzyme-linked immunosorbent assay 4 hours after LPS injection. Plasma alanine aminotransferase, creatine kinase-MB, and diamine oxidase contents were detected 24 hours after LPS injection. In cell experiments, rat peritoneal macrophages were collected and initially pretreated with atropine (muscarinic cholinergic receptor antagonist) or α-Bungarotoxin (an antagonist that specifically binds α7 subunit of nicotinic cholinergic receptor), then with carbachol or nicotine, and finally stimulated with LPS. Contents of TNF-α, IL-6, and IL-10 in supernatant were assayed by enzyme-linked immunosorbent assay. Furthermore, macrophages were exposed to nicotine and carbachol of high concentration and then stained with fluorescein isothiocyanate-labeled α-bungarotoxin and observed with fluorescent confocal microscopy.

RESULTS

Carbachol inhibited expression of TNF-α and IL-6 after LPS injection and had no significant effect on IL-10 in rat endotoxemia model. It also inhibited the increase of plasma alanine aminotransferase and creatine kinase-MB contents whereas restored the inhibited plasma diamine oxidase activity. Cell experiments also showed that increases of TNF-α and IL-6 after LPS stimulation could be significantly inhibited by carbachol or nicotine, whereas IL-10 was not apparently altered. Atropine did not downregulate the inhibitive effects of both carbachol and nicotine, whereas α-bungarotoxin significantly downregulated these effects. Fluorescent confocal microscopy showed that nicotine and carbachol pretreatment markedly reduced the intensity of binding between fluorescein isothiocyanate-labeled α-bungarotoxin and macrophages.

CONCLUSION

The results suggested that both carbachol and nicotine play a role in the anti-inflammatory process and organ function protection through the α7 subunit of nicotinic cholinergic receptor.

Inflammatory bowel disease

Inflammatory bowel diseases (IBDs) encompass ulcerative colitis, Crohn's disease, and indeterminate colitis, all of which are characterized by remission and exacerbation of gastrointestinal symptoms, and a variety of extraintestinal manifestations including those affecting the oral cavity. Although not particularly a cause for mortality, inflammatory bowel diseases are associated with significant morbidity and impact on the quality of life. This article reviews clinical presentation, diagnostic criteria, and therapeutic modalities for the 2 main types of inflammatory bowel disease and discusses manifestations of these conditions in the oral cavity. The role of the oral health care provider in timely recognition and referral for medical work-up as well as management of oral complaints is also emphasized.

Chronic nicotine inhibits inflammation and promotes influenza infection

Epidemiological data suggest an association between smoking, respiratory infections, and impaired wound healing. Inflammation is critical in the body's defense against pathogens and in the wound-healing process. Although nicotine is used to treat some inflammatory conditions, the mechanism of this action is largely unknown. To determine how nicotine affects inflammation, rats and mice were exposed to nicotine via miniosmotic pumps, and the inflammatory response to turpentine or influenza virus was assessed. Results showed that while nicotine suppressed the migration of leukocytes to the inflammation/infection site, it increased the influenza titer in the lung. The decreased inflammation correlated with lower chemotaxis/chemokinesis of peripheral blood mononuclear cells (PBMC) toward formyl-methionyl-leucyl-phenylalanine and monocyte chemoattractant protein-1 without affecting the density of their respective receptors. However, nicotine suppressed the chemokine-induced Ca(2+) response in PBMC, indicating impaired chemokine signaling. Thus, because nicotine suppresses leukocyte migration, it might contribute to the delayed wound healing and increased incidence of respiratory infections among smokers.

Management of refractory inflammatory bowel disease

One of the most challenging aspects of the management of inflammatory bowel disease is the high frequency of incomplete or absent response to medical therapy. Although many patients may be truly refractory to medical therapy, a lack of response may indicate several possibilities, including incorrect diagnosis, progression of disease extent, intestinal complication, superinfection, underdosing of therapy, monotherapy instead of combination therapy, or medication intolerance. This article provides a practical general approach to refractory inflammatory bowel disease patients encountered in clinical practice.

Dextran sodium sulphate-induced colitis perturbs muscarinic cholinergic control of colonic epithelial ion transport

1. Neuronal cholinergic input is an important regulator of epithelial electrolyte transport and hence water movement in the gut. 2. In this study, colitis was induced by treating mice with 4% (w v(-1)) dextran sodium-sulphate (DSS)-water for 5 days followed by 3 days of normal water. Mid-colonic segments were mounted in Ussing chambers and short-circuit current (Isc, indicates net ion movement) responses to the cholinergic agonist, carbachol (CCh; 10(-4) M)+/-tetrodotoxin, atropine (ATR), hexamethonium (HEX), naloxone or phenoxybenzamine were assessed. 3. Tissues from mice with DSS-induced colitis displayed a drop in Isc in response to CCh (-11.3+/-3.3 microA/cm(2)), while those from control mice showed a transient increase in Isc (76.3+/-13.0 microA/cm(2)). The DeltaIsc in colon from DSS-treated mice was tetrodotoxin-sensitive, atropine-insensitive and was reversed by hexamethonium (HEX+CCh=16.7+/-7.8 microA/cm(2)), indicating involvement of a nicotinic receptor. 4. CCh induced a drop in Isc in tissues from controls only when they were pretreated with the cholinergic muscarinic receptor blocker, atropine: ATR+CCh=-21.3+/-7.0 microA/cm(2). Nicotine elicited a drop in Isc in Ussing-chambered colon from both control and DSS-treated mice that was TTX-sensitive. 5. The drop in Isc evoked by CCh challenge of colonic tissue from DSS-treated mice or ATR+CCh challenge of control tissue was not significantly affected by blockade of opiate or alpha-adrenergic receptors by naloxone or phenoxybenzamine, respectively. 6. The data indicate that DSS-colitis reveals a nicotinic receptor that becomes important in cholinergic regulation of ion transport.

Medical therapy for ulcerative colitis

Although newer therapeutic agents are being developed for the treatment of inflammatory bowel disease, aminosalicylates and corticosteroids remain the mainstay of treatment for UC (Tables 2-5). Patients who do not respond to these agents or become steroid dependent require immunomodulatory therapy or curative surgery. Cyclosporine represents the greatest treatment advance for UC in 10 years. The role of nicotine, heparin, antibiotics, probiotics, and SCFA in the treatment of UC is less clear, but these agents may offer an alternative therapeutic approach for patients intolerant or nonresponsive to standard therapy.

Enantiospecific synthesis of annulated nicotine analogues from D-glutamic acid. 7-Azabicyclo[2.2.1]heptano[2.3-c]pyridines

The conformationally restricted nicotinoid (1S,4S)-7-methyl-7-azabicyclo[2.2.1]heptano[2,3-c]pyridine dihydrochloride has been prepared enantiospecifically from D-glutamic acid. The method involved a lithium cis-2,6-dimethylpiperidide-mediated intramolecular anionic cyclization of (2S,5R)-N-(tert-butyloxycarbonyl)-5-[3-(4-N-chloropyridinyl]proline methyl ester in tandem with a standard decarboxylation sequence. Reductive amination afforded the desired N-methylated [2.2.1]bicyclonicotinoid. Cyclization of the corresponding iodopyridinylproline methyl ester, obtained via ultrasound-facilitated chloro-iodo exchange, was also effected.

Vagus nerve stimulation attenuates the systemic inflammatory response to endotoxin

Vertebrates achieve internal homeostasis during infection or injury by balancing the activities of proinflammatory and anti-inflammatory pathways. Endotoxin (lipopolysaccharide), produced by all gram-negative bacteria, activates macrophages to release cytokines that are potentially lethal. The central nervous system regulates systemic inflammatory responses to endotoxin through humoral mechanisms. Activation of afferent vagus nerve fibres by endotoxin or cytokines stimulates hypothalamic-pituitary-adrenal anti-inflammatory responses. However, comparatively little is known about the role of efferent vagus nerve signalling in modulating inflammation. Here, we describe a previously unrecognized, parasympathetic anti-inflammatory pathway by which the brain modulates systemic inflammatory responses to endotoxin. Acetylcholine, the principle vagal neurotransmitter, significantly attenuated the release of cytokines (tumour necrosis factor (TNF), interleukin (IL)-1beta, IL-6 and IL-18), but not the anti-inflammatory cytokine IL-10, in lipopolysaccharide-stimulated human macrophage cultures. Direct electrical stimulation of the peripheral vagus nerve in vivo during lethal endotoxaemia in rats inhibited TNF synthesis in liver, attenuated peak serum TNF amounts, and prevented the development of shock.