Effect of smoking and abstention on oxidative burst and reactivity of neutrophils and monocytes

The impact of smoking on complications after operatively treated ankle fractures--a follow-up study of 906 patients

OBJECTIVES

This study on patients with operatively treated ankle fractures aimed to investigate the impact of smoking on postoperative complications and especially deep wound infections.

DESIGN

Cohort study with prospective follow-up.

SETTING

University-associated teaching hospital with advanced trauma care.

PATIENTS

A consecutive series of patients (n = 906) operatively treated for an acute ankle fracture during a 3-year period was identified. For the analysis, the patients were categorized as nonsmokers (n = 721) and smokers (n = 185). Data were collected from the department database and completed with a review of the patients' medical charts.

MAIN OUTCOME MEASURES

Postoperative complications.

RESULTS

Follow-up data at 6 weeks were available for 98.2% of the patients. Postoperative complications of any kind (30.1% versus 20.3%, P = 0.005) as well as deep wound infections (4.9% versus 0.8%, P < 0.001) were more common among smokers than nonsmokers. Multivariable analyses showed that smokers had six times higher odds of developing a deep infection compared with nonsmokers. A more complicated fracture, associated diabetes mellitus, and unsatisfactory operative fracture reduction also enhanced the risk of postoperative complications.

CONCLUSIONS

We conclude that cigarette smoking increases the risk of postoperative complications in patients operatively treated for an ankle fracture. Smoking is a considerable risk factor. Therefore, physicians, nurses, and other healthcare professionals should strive to support patients to stop smoking while still under acute treatment.

Morpho-functional modifications of human neutrophils induced by aqueous cigarette smoke extract: comparison with chemiluminescence activity

Cigarette smoking plays an important role as a cause of morbidity and mortality in humans, involving respiratory, cardiovascular, digestive and reproductive systems. Tobacco smoke contains a large number of molecules, some of which are proven carcinogens. Although not fully understood, polymorphonuclear leukocytes seem to play a crucial role in the mechanisms by which tobacco smoke compounds are implicated in smoke-related diseases. In this paper the effects of an aqueous cigarette smoke extract on the expression of adhesion molecules of polymorphonuclear leukocytes together with the changes in the cell morphology have been related to the chemiluminescence activity. The results obtained show that polymorphonuclear leukocytes treated with aqueous cigarette smoke extract are significantly impaired, as suggested by the changes of chemiluminescence activity, of membrane receptors (CD18, CD62), myeloperoxidase expression and of cell morphology. Altogether the present data indicate that treated polymorphonuclear leukocytes are ineffectively activated and therefore unable to phagocytize zymosan particles.

Postoperative complications in smoking patients treated with implants: a retrospective study

PURPOSE

To identify the risk of complications (eg, implant loss, infection, peri-implantitis, and mucositis) in a group of patients treated with osseointegrated implants and to assess the effect of smoking on this risk.

MATERIALS AND METHODS

A retrospective cohort study of patients treated in the Unit of Implantology, University of Barcelona Faculty of Dentistry was performed. All patients had already undergone prosthetic treatment, and the minimal follow-up time after implant surgery was 6 months.

RESULTS

A total of 295 patients fulfilled the inclusion criteria; 56.9% were women and 43.1% were men. They received a total of 1,033 implants. There were 209 complications (32 cases of implant loss, 2 cases of infection, 70 cases of peri-implantitis, and 105 cases of mucositis). The smoking habit was associated with an increased risk of complications (P = .008).

CONCLUSION

Smokers had an increased risk of complications, including infection, implant loss, mucositis, and peri-implantitis, compared with nonsmoking patients.

Increased leptin/leptin receptor pathway affects systemic and airway inflammation in COPD former smokers

Background

Leptin, a hormone produced mainly by adipose tissue, regulates food intake and energy expenditure. It is involved in inflammatory diseases such as chronic obstructive pulmonary disease (COPD) and its deficiency is associated with increased susceptibility to the infection. The leptin receptor is expressed in the lung and in the neutrophils.

Methods

We measured the levels of leptin, tumor necrosis factor alpha (TNF-α) and soluble form of intercellular adhesion molecule-1 (sICAM-1) in sputum and plasma from 27 smoker and former smoker patients with stable COPD using ELISA methods. Further we analyzed leptin and its receptor expression in sputum cells from 16 COPD patients using immunocytochemistry.

Results

In plasma of COPD patients, leptin was inversely correlated with TNF-α and positively correlated with the patient weight, whereas the levels of sICAM-1 were positively correlated with TNF-α. In sputum of COPD patients leptin levels were correlated with forced expiratory volume in 1 second/forced vitality capacity. Additionally, increased levels of sputum leptin and TNF-α were observed in COPD former smokers rather than smokers. Further the expression of leptin receptor in sputum neutrophils was significantly higher in COPD former smokers than in smokers, and the expression of leptin and its receptor was positively correlated in neutrophils of COPD former smokers.

Conclusion

Our findings suggest a role of leptin in the local and systemic inflammation of COPD and, taking into account the involvement of neutrophils in this inflammatory disease, describe a novel aspect of the leptin/leptin receptor pathway in the regulation of host defense after smoking cessation.

Cigarette smoke-exposed neutrophils die unconventionally but are rapidly phagocytosed by macrophages

Pulmonary accumulation of neutrophils is typical for active smokers who are also predisposed to multiple inflammatory and infectious lung diseases. We show that human neutrophil exposure to cigarette smoke extract (CSE) leads to an atypical cell death sharing features of apoptosis, autophagy and necrosis. Accumulation of tar-like substances in autophagosomes is also apparent. Before detection of established cell death markers, CSE-treated neutrophils are effectively recognized and non-phlogistically phagocytosed by monocyte-derived macrophages. Blockade of LOX-1 and scavenger receptor A, but not MARCO or CD36, as well as pre-incubation with oxLDL, inhibited phagocytosis, suggesting that oxLDL-like structures are major phagocytosis signals. Specific lipid (β-carotene and quercetin), but not aqueous, antioxidants increased the pro-phagocytic effects of CSE. In contrast to non-phlogistic phagocytosis, degranulation of secondary granules, as monitored by lactoferrin release, was apparent on CSE exposure, which is likely to promote pulmonary inflammation and tissue degradation. Furthermore, CSE-exposed neutrophils exhibited a compromised ability to ingest the respiratory pathogen, Staphylococcus aureus, which likely contributes to bacterial persistence in the lungs of smokers and is likely to promote further pulmonary recruitment of neutrophils. These data provide mechanistic insight into the lack of accumulation of apoptotic neutrophil populations in the lungs of smokers and their increased susceptibility to degradative pulmonary diseases and bacterial infections.

Effect of nicotine, cotinine and cigarette smoke extract on the neutrophil respiratory burst

AIMS

To determine the effect of nicotine, cotinine and cigarette smoke extract (CSE) on the neutrophil respiratory burst and their effect on activation of the nuclear factor-κB (NFκB) pathway in oral epithelium.

MATERIALS AND METHODS

Neutrophils from periodontally healthy individuals were treated with nicotine, cotinine and CSE before stimulation with Fusobacterium nucleatum, IgG-opsonized Staphylococcus aureus and Escherichia coli lipopolysaccharide. Total and extracellular reactive oxygen species (ROS) generation was determined by luminol/isoluminol chemiluminescence. Activation of NFκB in oral epithelial cells was determined by immunocytochemistry.

RESULTS

Smoke extract alone caused increased neutrophil extracellular isoluminol-dependent chemiluminescence, not detectable with luminol. However, pre-treatment with smoke extract reduced both total and extracellular ROS generation in response to all stimuli. Nicotine and cotinine had no effect on the neutrophil respiratory burst. Smoke extract, nicotine and cotinine did not induce oral epithelial cell NFκB activation.

CONCLUSIONS

These data demonstrate that smoke extract reduces the ability of neutrophils to generate ROS after stimulation with F. nucleatum and IgG-opsonized S. aureus but, at high concentrations, stimulates extracellular ROS generation. During periodontitis, cigarette smoking may differentially affect neutrophil function, generally preventing elimination of periodontal pathogens but, in heavy smokers, also stimulating ROS release and oxidative stress mediated tissue damage.

Interventions for preoperative smoking cessation

BACKGROUND

Smokers have a substantially increased risk of postoperative complications. Preoperative smoking intervention may be effective in decreasing this incidence, and surgery may constitute a unique opportunity for smoking cessation interventions.

OBJECTIVES

The objective of this review was to assess the effect of preoperative smoking intervention on smoking cessation at the time of surgery and 12 months postoperatively and on the incidence of postoperative complications.

SEARCH STRATEGY

The specialized register of the Cochrane Tobacco Addiction Group was searched using the free text and keywords (surgery) or (operation) or (anaesthesia) or (anesthesia). MEDLINE, EMBASE and CINAHL were also searched, combining tobacco- and surgery-related terms. Most recent search April 2010.

SELECTION CRITERIA

Randomized controlled trials that recruited people who smoked prior to surgery, offered a smoking cessation intervention, and measured preoperative and long-term abstinence from smoking and/or the incidence of postoperative complications.

DATA COLLECTION AND ANALYSIS

The authors independently assessed studies to determine eligibility. Results were discussed between the authors.

MAIN RESULTS

Eight trials enrolling a total of 1156 people met the inclusion criteria. One of these did not report cessation as an outcome. Two trials initiated multisession face to face counselling at least 6 weeks before surgery whilst six used a brief intervention. Nicotine replacement therapy (NRT) was offered or recommended to some or all participants in seven trials. Six trials detected significantly increased smoking cessation at the time of surgery, and one approached significance. Subgroup analyses showed that both intensive and brief intervention significantly increased smoking cessation at the time of surgery; pooled RR 10.76 (95% confidence interval (CI) 4.55 to 25.46, two trials) and RR 1.41 (95% CI 1.22 to 1.63, five trials) respectively. Four trials evaluating the effect on long-term smoking cessation found a significant effect; pooled RR 1.61 (95% CI 1.12 to 2.33). However, when pooling intensive and brief interventions separately, only intensive intervention retained a significant effect on long-term smoking cessation; RR 2.96 (95% CI 1.57 to 5.55, two trials).Five trials examined the effect of smoking intervention on postoperative complications. Pooled risk ratios were 0.70 (95% CI 0.56 to 0.88) for developing any complication; and 0.70 (95% CI 0.51 to 0.95) for wound complications. Exploratory subgroup analyses showed a significant effect of intensive intervention on any complications; RR 0.42 (95% CI 0.27 to 0.65) and on wound complications RR 0.31 (95% CI 0.16 to 0.62). For brief interventions the effect was not statistically significant but CIs do not rule out a clinically significant effect (RR 0.96 (95% CI 0.74 to 1.25) for any complication, RR 0.99 (95%CI 0.70 to 1.40) for wound complications).

AUTHORS' CONCLUSIONS

There is evidence that preoperative smoking interventions including NRT increase short-term smoking cessation and may reduce postoperative morbidity. The optimal preoperative intervention intensity remains unknown. Based on indirect comparisons and evidence from two small trials, interventions that begin four to eight weeks before surgery, include weekly counselling, and use NRT are more likely to have an impact on complications and on long-term smoking cessation.

Exogenous factors in the immunotoxicity of oral PMN

Current evidence indicates that periodontal disease is frequently due to inappropriate levels of gingival granulocyte functions. Reason of this failure may be the toxic effects of a number of local or systemic exogenous factors, capable of spreading through the gingival crevice environment, and strongly conditioning the granulocyte activities. The wide list includes bacteria and granulotoxic products, hedonistic drugs (mainly tobacco), and chemotherapeutic agents (especially antimicrobials used for preventing or reducing the accumulation of dental plaque). Almost always, their presence induces a time- and/or dose-dependent toxicity.

Smoking attenuates wound inflammation and proliferation while smoking cessation restores inflammation but not proliferation

Full-thickness 5 mm punch biopsy wounds were made lateral to the sacrum in 48 smokers and 30 never smokers. After 1 week, the wounds were excised and fixed. The smokers were then randomized to continuous smoking or abstinence with a transdermal nicotine patch or a placebo patch. The sequence of wounding and excision was repeated after 4, 8, and 12 weeks. All excised tissue was stained with hematoxylin-eosin and immunohistochemically for macrophages (CD68), procollagen 1 N-terminal propeptide (PINP) in fibroblasts, and endothelial cells (CD31). The cellularity was assessed and scored by two independent histopathologists, and for the analysis, proportional odds models and random effect models for repeated measurements were applied. Macrophages and PINP-stained fibroblasts were reduced in the smokers' wounds (0.28 [0.14-0.58] [OR, 95%CI]; p=0.01 and 0.37[0.19-0.70]; p<0.01, respectively, when compared with never smokers' wounds). Inflammation scores were marginally affected. Following smoking cessation, inflammatory cell infiltration and macrophages in the wounds increased. PINP-stained fibroblasts were unaffected. Neovascularization was not affected by smoking or abstinence. Wound inflammation and fibroblast proliferation were attenuated in smokers, suggesting delayed healing. Abstinence from smoking restores inflammation, but does not affect proliferation. These findings suggest a pathophysiologic mechanism for postoperative wound infection and dehiscence in smokers and why smoking cessation appears to reduce wound infection but not dehiscence.

Anastomotic leakage after anterior resection for rectal cancer: risk factors

OBJECTIVE

The study aimed to identify risk factors for clinical anastomotic leakage (AL) after anterior resection for rectal cancer in a consecutive national cohort.

METHOD

All patients with an initial first diagnosis of colorectal adenocarcinoma were prospectively registered in a national database. The register included 1495 patients who had had a curative anterior resection between May 2001 and December 2004. The association of a number of patient- and procedure-related factors with clinical AL after anterior resection was analysed in a cohort design.

RESULTS

Anastomotic leakages occurred in 163 (11%) patients. In a multivariate analysis, the risk of AL was significantly increased in patients with tumours located below 10 cm from the anal verge if no faecal diversion was undertaken (OR 5.37 5 cm (tumour level from anal verge), 95% CI 2.10-13.7, OR 3.57 7 cm, CI 1.81-7.07 and OR 1.96 10 cm, CI 1.22-3.10), in male patients (OR 2.36, CI 1.18-4.71), in smokers (OR 1.88, CI 1.02-3.46), and perioperative bleeding (OR 1.05 for intervals of 100 ml blood loss, CI 1.02-1.07).

CONCLUSION

Anastomotic leakage after anterior resection for low rectal tumours is related to the level, male gender, smoking and perioperative bleeding. Faecal diversion is advisable after total mesorectal excision of low rectal tumours in order to prevent AL.

Smoking is a major risk factor for wound dehiscence after midline abdominal incision; case-control study

BACKGROUND

The incidence of acute fascial wound dehiscence (AFWD) after major abdominal operations is as high as 3%. AFWD is associated with mortality rates of 15-20%. Male gender, advanced age and numerous systemic factors including malignancy hypoproteinemia and steroid use have been associated with increased risk. The aim of the present study was to investigate the association between smoking prevalence and AFWD.

METHODS

Middlemore Hospital records were retrieved from the 1997-2006 period for patients who had undergone midline abdominal surgery and developed AFWD. A return to the operating theatre for closure of the fascial dehiscence was required for study group inclusion. Each patient in the study group was matched to two control patients who had been admitted in the same year for surgery and who had a similar initial surgical intervention. Conditional logistic regression was used to calculate odds ratios with 95% confidence intervals, representing the risk of developing fascial wound dehiscence in smokers compared with the non-smoking group.

RESULTS

There were 52 patients (32 male, 20 female) and 104 controls (64 male, 40 female). Median age for both groups was 63 years. A history of heavy tobacco use (> or =20 pack-years) was more prevalent in those who had AFWD (46%) compared with the control group (16%; P = 0.0002; odds ratio 3.7).

CONCLUSIONS

Smoking is associated with an increased incidence of acute fascial wound dehiscence following laparotomy. It is not known whether smoking is a causal or a surrogate factor.

Reactivation of inflammatory bowel disease in a mouse model of depression

BACKGROUND & AIMS

Patients with inflammatory bowel disease (IBD) frequently also have depression, yet little is known of its role in IBD pathogenesis. We investigated whether the development of depression after the establishment of chronic inflammation reactivates an acute relapse of IBD and underlying pharmacologic mechanisms in mouse models.

METHODS

Colitis was induced by administration of dextran sulfate sodium (DSS) or dinitrobenzenesulfonic acid to C57BL/6 mice. Depression was induced by olfactory bulbectomy or chronic intracerebroventricular injection of reserpine. Colitis was reactivated by subsequent exposure to DSS or dinitrobenzenesulfonic acid. Some mice were given the antidepressant desmethylimipramine. Acute DSS-colitis was induced in mice lacking the alpha 7 subunit of the nicotinic acetylcholine receptor (alpha 7nAchR), and vagotomy was performed. Disease severity and colon tissue histology and inflammation were evaluated. Levels of C-reactive protein and proinflammatory cytokines were determined by enzyme-linked immunosorbent assay analysis of colon samples and macrophage culture.

RESULTS

Induction of depression reactivated inflammation in mice in which colitis had been established and become quiescent. The induction was associated with impaired cholinergic inhibition of proinflammatory cytokine secretion by macrophages and mediated by alpha 7nAchR on these cells; macrophages isolated from depressed mice showed increased proinflammatory cytokine secretion. Depression-induced reactivation of colitis was prevented by desmethylimipramine and accompanied by a normalization of proinflammatory cytokine secretion.

CONCLUSIONS

Depression reactivates dormant chronic colitis via the alpha 7nAchR. These findings encourage closer monitoring of behavior for signs of depression in IBD patients because treatment might prevent inflammatory conditions. Furthermore, alpha 7nAchR agonists might achieve this effect without the need for psychotropic medication.

Tobacco use increases susceptibility to bacterial infection

Active smokers and those exposed to secondhand smoke are at increased risk of bacterial infection. Tobacco smoke exposure increases susceptibility to respiratory tract infections, including tuberculosis, pneumonia and Legionnaires disease; bacterial vaginosis and sexually transmitted diseases, such as chlamydia and gonorrhoea; Helicobacter pylori infection; periodontitis; meningitis; otitis media; and post-surgical and nosocomial infections. Tobacco smoke compromises the anti-bacterial function of leukocytes, including neutrophils, monocytes, T cells and B cells, providing a mechanistic explanation for increased infection risk. Further epidemiological, clinical and mechanistic research into this important area is warranted.

Anastomotic leaks after anterior resection for mid and low rectal cancer: survey of the Italian Society of Colorectal Surgery

BACKGROUND

The aim of the survey was to assess the incidence of anastomotic leaks (AL) and to identify risk factors predicting incidence and gravity of AL after low anterior resection (LAR) for rectal cancer performed by colorectal surgeons of the Italian Society of Colorectal Surgery (SICCR).

METHODS

Information about patients with rectal cancers less than 12 cm from the anal verge who underwent LAR during 2005 was collected retrospectively. AL was classified as grade I to IV according to gravity. Fifteen clinical variables were examined by univariate and multivariate analyses. Further analysis was conducted on patients with AL to identify factors correlated with gravity.

RESULTS

There were 520 patients representing 64% of LAR for rectal cancer performed by SICCR members. The overall rate of AL was 15.2%. Mortality was 2.7% including 0.6% from AL. The incidence of AL was correlated with higher age (p<0.05), lower (<20 per year) centre case volume (p<0.05), obesity (p<0.05), malnutrition (p<0.01) and intraoperative contamination (p<0.05), and was lower in patients with a colonic J-pouch reservoir (p<0.05). In the multivariate analysis age, malnutrition and intraoperative contamination were independent predictors. The only predictor of severe (grade III/IV) AL was alcohol/smoking habits (p<0.05) while the absence of a diverting stoma was borderline significant (p<0.07).

CONCLUSION

Our retrospective survey identified several risk factors for AL. This survey was a necessary step to construct prospective interventional studies and to establish benchmark standards for outcome studies.

The influence of nicotine on granulocytic differentiation - inhibition of the oxidative burst and bacterial killing and increased matrix metalloproteinase-9 release

Background

Neutrophils leave the bone marrow as terminally differentiated cells, yet little is known of the influence of nicotine or other tobacco smoke components on neutrophil differentiation. Therefore, promyelocytic HL-60 cells were differentiated into neutrophils using dimethylsulfoxide in the presence and absence of nicotine (3-(1-methyl-2-pyrrolidinyl) pyridine). Differentiation was evaluated over 5 days by monitoring terminal differentiation markers (CD11b expression and formazan deposition); cell viability, growth phase, kinetics, and apoptosis; assessing cellular morphology and ultrastructure; and conformational changes to major cellular components. Key neutrophil effector functions (oxidative burst, bacterial killing, matrix metalloproteinase release) were also examined.

Results

Nicotine increased the percentage of cells in late differentiation phases (metamyelocytes, banded neutrophils and segmented neutrophils) compared to DMSO alone (p < 0.05), but did not affect any other marker of neutrophil differentiation examined. However, nicotine exposure during differentiation suppressed the oxidative burst in HL-60 cells (p < 0.001); inhibited bacterial killing (p < 0.01); and increased the LPS-induced release of MMP-9, but not MMP-2 (p < 0.05). These phenomena may be α-7-acetylcholine nicotinic receptor-dependent. Furthermore, smokers exhibited an increased MMP-9 burden compared to non-smokers in vivo (p < 0.05).

Conclusion

These findings may partially explain the known increase in susceptibility to bacterial infection and neutrophil-associated destructive inflammatory diseases in individuals chronically exposed to nicotine.

Hyper-reactive PMNs in FcγRIIa 131 H/H genotype periodontitis patients

BACKGROUND

Receptors for the Fc part of IgG (FcgammaRIIa) on polymorphonuclear leukocytes (PMN) mediate phagocytosis and cell activation. Previous results show that one of the genetic variants of the FcgammaRIIa, the 131 H/H, is associated with more periodontal breakdown than the R/R. This may be due to hyper-reactivity of the H/H-PMNs upon interaction with bacteria.

AIM

To study whether the FcgammaRIIa genotype modifies the PMN reactivity in periodontitis patients.

MATERIAL AND METHODS

A cohort of 98 periodontitis patients was genotyped. From these, 10 H/H and 10 R/R consented to participate. PMNs were incubated with immune serum-opsonized Actinobacillus actinomycetemcomitans (A.a.). Phagocytosis, degranulation (CD63 and CD66b expression), respiratory burst and elastase release were assessed.

RESULTS

Patients of the H/H genotype showed more bone loss than those with the H/R or R/R genotype (p=0.038). H/H-PMNs phagocytosed more opsonized A.a. than did R/R-PMNs (p=0.019). The H/H-PMNs also expressed more CD63 and CD66b than did the R/R-PMNs (p=0.004 and 0.002, respectively) and released more elastase (p=0.001).

CONCLUSIONS

The genotyping results confirm previous reports that more periodontal destruction occurs in the H/H genotype than in the H/R or R/R genotype. The functional studies indicate a hyper-reactivity of the H/H-PMN in response to bacteria, which may be one of several pathways leading to more periodontal breakdown.

Skin and Soft Tissue Infections in Older Adults

Skin and soft tissue infections (SSTIs) are a common cause of morbidity in older patients. Because of changes in skin consistency, immunosenescence, and the presence of underlying skin conditions and comorbid conditions, elderly persons are at high risk for SSTIs. Specific community- and hospital-associated SSTIs are reviewed in this article with particular emphasis on the epidemiology, prevention, risk factors, and treatment of SSTIs in older patients.

The alpha7 nicotinic acetylcholine receptor as a pharmacological target for inflammation

The physiological regulation of the immune system encompasses comprehensive anti-inflammatory mechanisms that can be harnessed for the treatment of infectious and inflammatory disorders. Recent studies indicate that the vagal nerve, involved in control of heart rate, hormone secretion and gastrointestinal motility, is also an immunomodulator. In experimental models of inflammatory diseases, vagal nerve stimulation attenuates the production of proinflammatory cytokines and inhibits the inflammatory process. Acetylcholine, the principal neurotransmitter of the vagal nerve, controls immune cell functions via the alpha7 nicotinic acetylcholine receptor (alpha7nAChR). From a pharmacological perspective, nicotinic agonists are more efficient than acetylcholine at inhibiting the inflammatory signaling and the production of proinflammatory cytokines. This 'nicotinic anti-inflammatory pathway' may have clinical implications as treatment with nicotinic agonists can modulate the production of proinflammatory cytokines from immune cells. Nicotine has been tested in clinical trials as a treatment for inflammatory diseases such as ulcerative colitis, but the therapeutic potential of this mechanism is limited by the collateral toxicity of nicotine. Here, we review the recent advances that support the design of more specific receptor-selective nicotinic agonists that have anti-inflammatory effects while eluding its collateral toxicity.

Evaluation of postoperative peritoneal adhesion formation following perioperative nicotine administration

PURPOSE

The primary step in postoperative peritoneal adhesion formation involves the exudation of fibrin through permeable mesenteric capillaries. Nicotine, the most potent constituent of cigarette smoke, augments the release of vascular endothelial growth factor (VEGF), which increases vascular permeability. The objective of this study was to evaluate the effect of nicotine on postlaparotomy abdominal adhesions.

METHODS

CD-1 mice were randomized to receive, ad libitum, either water alone (as 2% sucrose solution) or water mixed with 100 microg/mL nicotine (to obtain blood levels equivalent to a 1 pack/day smoker) (n = 32 mice per group). After 1 wk, all mice underwent laparotomy to induce adhesion formation using the same experimental method (consisting of laparotomy with cecal abrasion to achieve serosal punctuate hemorrhage). Fourteen days later, all animals were sacrificed for adhesion grading (0 to 3) by a blinded observer. Additionally, peritoneal lavage fluid from separate mice receiving either water or nicotine water before their surgery or else undergoing sham laparotomy was retrieved at 2, 6, and 24 h postoperatively (4 mice per group/time point) and assessed for VEGF concentrations.

RESULTS

The nicotine treated group had a mean +/- SEM adhesion score of 2.4 +/- 0.2, which was significantly greater than that of the control group (1.2 +/- 0.2) (P < 0.05, Mann Whitney U test.). This correlated with a significant increase in peritoneal VEGF levels occurring at 6 and 24 h in the nicotine group.

CONCLUSION

Peritoneal adhesion formation after surgery is increased in mice receiving nicotine perioperatively. This effect may be mediated through a direct augmentation of peritoneal VEGF release by nicotine with a subsequent increase in mesenteric endothelial permeability. These findings could have significant implications for smokers undergoing intra-abdominal surgical procedures.

The potential association between smoking and endodontic disease

The aim of this review was to analyse the literature to assess the possibility of an association between smoking and endodontic disease and the prognosis of endodontically treated teeth. The review of the prognosis of endodontically treated teeth involved taking account of any potential associations with smoking and endodontic disease and marginal periodontitis, and smoking and prosthodontic outcomes. In addition, the role of smoking in implant failure and surgical wound healing was analysed with a view to drawing parallels regarding the possible implications of smoking on the outcome of surgical endodontics. A MEDLINE and Cochrane library search including smoking and various endodontic keyword searches identified three papers which discussed the variables, and did not just mention them separately in the text. The literature demonstrates a paucity of evidence relating smoking with endodontic disease and prognosis, but nevertheless presents evidence of a possible influence on the prognosis of endodontically treated teeth in smokers and a likely increase in surgical complications. The possible merits of a smoking cessation protocol prior to surgical endodontics are also discussed.

Transdermal nicotine patch enhances type I collagen synthesis in abstinent smokers

Cigarette smokers deposit less collagen, expressed as hydroxyproline, in granulation tissue than nonsmokers. We studied the effect of abstinence from smoking and transdermal nicotine patches on deposition of hydroxyproline, proline, type I procollagen, and total proteins. Fifty-four healthy smokers were studied during 10 days of smoking and again from days 10 to 20 following smoking cessation. After the first 10 days of abstinence they were randomized to double-blind treatment with transdermal nicotine patches of 25 mg/day or placebo for a period of 10 days. During this period and during smoking, an expanded polytetrafluoroethylene tube was implanted into the subcutis. Following removal of the implant, total amino acids and peptides were extracted. Hydroxyproline and proline were analyzed by high-pressure liquid chromatography, type I procollagen was analyzed by enzyme-linked immunoassay, and total proteins were determined colorimetrically. In the 39 subjects who complied with the study protocol, abstinence from smoking did not affect the deposition of hydroxyproline, proline, type I procollagen, or total protein in the implants. During abstinence, the type I procollagen level increased by 18% in the transdermal nicotine patches group and decreased by 10% in the placebo group (p<0.05). We conclude that 20 days of abstinence from smoking does not affect collagen deposition in granulation tissue. However, in abstinent smokers, transdermal nicotine patches appears to increase type I collagen synthesis.

Effect of lifestyle, gender and age on collagen formation and degradation

Historically, inappropriate lifestyle with an inadequate dietary intake of vitamin C has been associated with poor wound healing as a clinical manifestation of scurvy. In modern times, clinical evidence produced over the past few decades indicates that a modern lifestyle factor, such as smoking, together with biologic characteristics, like old age and male gender, are risk factors for abdominal wall hernia and recurrence. The pathologic pathways for these clinical observations are unclear. Yet, evidence from animal and human studies suggests that these exogenous and endogenous factors may have a negative impact on collagen metabolism, enhancing degradation and impairing formation.

Evidence-Based Protocol for Diabetic Foot Ulcers

BACKGROUND

Diabetic foot ulcers are the single biggest risk factor for nontraumatic foot amputations in persons with diabetes. Foot ulcers occur in 12 to 25 percent of persons with diabetes and precede 84 percent of all nontraumatic amputations in this growing population. Because of the high incidence of foot ulcers, amputations remain a source of morbidity and mortality in persons with diabetes. Strict adherence to evidence-based protocols as described herein will prevent the majority of these amputations.

METHODS

The collective experience of treating patients with neuropathic diabetic foot ulcers in four major diabetic foot programs in the United States and Europe was analyzed.

RESULTS

The following protocol was developed for patients with diabetic foot ulcers: (1) establishment of good communication among the patient, the wound healing team, and the primary medical doctor; (2) comprehensive, protocol-driven care of the entire patient, including hemoglobin A1c, microalbuminuria, and cholesterol as well as early treatment of retinopathy, nephropathy, and cardiac disease; (3) weekly objective measurement of the wound with digital photography, planimetry, and documentation of the wound-healing process using the Wound Electronic Medical Record, if available; (4) objective evaluation of blood flow in the lower extremities (e.g., noninvasive flow studies); (5) débridement of hyperkeratotic, infected, and nonviable tissue; (6) use of systemic antibiotics for deep infection, drainage, and cellulitis; (7) off-loading; (8) maintenance of a moist wound bed; (9) use of growth factor and/or cellular therapy if the wound is not healing after 3 weeks with this protocol; and (10) consideration of the use of vacuum-assisted therapy in complex wounds.

CONCLUSIONS

In diabetic foot ulcers, availability of the above modalities, in combination with early recognition and comprehensive treatment, ensures rapid healing, minimizes morbidity and mortality rates, and eliminates toe and limb amputations in the absence of ischemia and osteomyelitis.

Risk factors for tissue and wound complications in gastrointestinal surgery

BACKGROUND

Surgical site infections and disruption of sutured tissue are frequent complications following surgery. We aimed to assess risk factors predictive of tissue and wound complications in open gastrointestinal surgery.

METHODS

Data from 4855 unselected patients undergoing open gastrointestinal surgery from 1995 through 1998 were recorded in a clinical database and validated. The database embraced variables related to patient history, preoperative clinical condition, operative findings and severity, and the surgeon's training. Variables predictive of surgical site infection and dehiscence of sutured tissue within 30 days after surgery were assessed by multiple logistic regression analysis.

RESULTS

Following elective operation, the incidence of tissue and wound complications was 6% compared with 16% in emergency surgery (P < 0.001). These complications resulted in prolonged hospitalization in 50% of the patients and a 3-fold higher risk of reoperation but not increased mortality. Factors associated with complications following elective operations were smoking, comorbidity, and perioperative blood loss. Following emergency operations, male gender, peritonitis, and multiple operations were predictors of complications. Irrespective of elective or emergency surgery, the type of operation was a predictor of complications.

CONCLUSION

Factors known to affect the process of tissue and wound healing are independently associated with tissue and wound complications following gastrointestinal surgery.

Mechanisms of action of environmental factors--tobacco smoking

AIM

To review the potential biological mechanisms underlying the effects of tobacco smoking on periodontitis.

MAIN FINDINGS

Smoking has major effects on the host response, but there are also a number of studies that show some microbiological differences between smokers and non-smokers. Smoking has a long-term chronic effect on many important aspects of the inflammatory and immune responses. Histological studies have shown alterations in the vasculature of the periodontal tissues in smokers. Smoking induces a significant systemic neutrophilia, but neutrophil transmigration across the periodontal microvasculature is impeded. The suppression of neutrophil cell spreading, chemokinesis, chemotaxis and phagocytosis have been described. Protease release from neutrophils may be an important mechanism in tissue destruction. Tobacco smoke has been found to affect both cell-mediated immunity and humoral immunity. Research on gingival crevicular fluid has demonstrated that there are lower levels of cytokines, enzymes and possibly polymorphonuclear cells in smokers. In vitro studies have shown detrimental effects of nicotine and some other tobacco compounds on fibroblast function, including fibroblast proliferation, adhesion to root surfaces and cytotoxicity.

CONCLUSION

Tobacco smoking has widespread systemic effects, many of which may provide mechanisms for the increased susceptibility to periodontitis and the poorer response to treatment.