Ultrastructural changes in platelet membranes due to cigarette smoking

Bone regeneration in implant dentistry: Which are the factors affecting the clinical outcome?

The key factors that are needed for bone regeneration to take place include cells (osteoprogenitor and immune-inflammatory cells), a scaffold (blood clot) that facilitates the deposition of the bone matrix, signaling molecules, blood supply, and mechanical stability. However, even when these principles are met, the overall amount of regenerated bone, its stability over time and the incidence of complications may significantly vary. This manuscript provides a critical review on the main local and systemic factors that may have an impact on bone regeneration, trying to focus, whenever possible, on bone regeneration simultaneous to implant placement to treat bone dehiscence/fenestration defects or for bone contouring. In the future, it is likely that bone tissue engineering will change our approach to bone regeneration in implant dentistry by replacing the current biomaterials with osteoinductive scaffolds combined with cells and mechanical/soluble factors and by employing immunomodulatory materials that can both modulate the immune response and control other bone regeneration processes such as osteogenesis, osteoclastogenesis, or inflammation. However, there are currently important knowledge gaps on the biology of osseous formation and on the factors that can influence it that require further investigation. It is recommended that future studies should combine traditional clinical and radiographic assessments with non-invasive imaging and with patient-reported outcome measures. We also envisage that the integration of multi-omics approaches will help uncover the mechanisms responsible for the variability in regenerative outcomes observed in clinical practice.

Principles of minimize bleeding and the transfusion of blood and its components in operated patients - surgical aspects

One of the target of perioperative tratment in surgery is decreasing intraoperative bleeding, which increases the number of perioperative procedures, mortality and treatment costs, and also causes the risk of transfusion of blood and its components. Trying to minimize the blood loss(mainly during the operation) as well as the need to transfuse blood and its components (broadly understood perioperative period) should be standard treatment for a patient undergoing a procedure. In the case of this method, the following steps should be taken: 1) in the preoperative period: identyfication of risk groups as quickly as possible, detecting and treating anemia, applying prehabilitation, modyfying anticoagulant treatment, considering donating one's own blood in some patients and in selected cases erythropoietin preparations; 2) in the perioperative period: aim for normothermia, normovolemia and normoglycemia, use of surgical methods that reduce bleeding, such as minimally invasive surgery, high-energy coagulation, local hemostatics, prevention of surgical site infection, proper transfusion of blood and its components if it occurs; 3) in the postoperative period: monitor the condition of patients, primarily for the detection of bleeding, rapid reoperation if required, suplementation (oral administration preferred) nutrition with microelements (iron) and vitamins, updating its general condition. All these activities, comprehensively and in surgical cooperation with the anesthesiologist, should reduce the blood loss and transfusion of blood and its components.

Impacts of cigarette smoking on blood circulation: do we need a new approach to blood donor selection?

Smoking is a major public health problem and is considered the leading cause of preventable death worldwide. Gas-phase smoke carries bioactive substances and toxic compounds, affecting human health and reducing life spans. The negative effects of smoking on red blood cell (RBC) quality include destroying RBCs and increasing carboxy hemoglobin (COHb). Smoking increases the concentrations of heavy metals such as cadmium (Cd) and lead (Pb) in the blood. Moreover, tobacco smoking has been found to be associated with heightened platelet (PLT)-dependent thrombin level which will induce a prothrombotic state. Smoking may affect the blood circulation of donors, and subsequently the blood components, and ultimately the recipients of transfusion. Nevertheless, there are no restrictions on smoking for volunteer blood donor screenings currently. We reviewed the articles about the influence of smoking on smokers' blood circulation as well as the impact of donated blood products on transfusion when these smokers act as blood donors. We aim to attract blood collection centers' attention to strengthen the management of blood donors who smoke, avoiding their use in massive transfusion protocol and susceptible recipients, especially pediatric ones.

Effects of smoking on controlled hypotension with nitroglycerin during ear-nose-throat surgery

Background and Aim

In this study, the aim was to research the effects of smoking habits on controlled hypotension administered with nitroglycerin during ear-nose-throat surgery.

Materials and Methods

This study administered controlled hypotension with nitroglycerin and total intravenous anesthesia to a total of 80 patients undergoing septoplasty operations. The patients were divided into two groups of 40 non-smokers (Group 1) and 40 smokers (Group 2). Intravenous propofol infusion was used for anesthesia maintenance. Nitroglycerin with 0.25-1 μg/kg/min dose was titrated to provide controlled hypotension. During this process, the hemodynamic parameters of patients, total propofol and nitroglycerin amounts used, operation duration, and duration of controlled hypotension were recorded at the end of the operation. At the end of the operation, the surgeon assessed the lack of blood in the surgical field with Fromme Scale.

Results

Fromme scale values were significantly higher in Group 2 compared to Group 1. The MAP values at 10, 20, 30 min, and end of operation were lower, while 10- and 20-min heart rate values were higher in Group 2 compared to Group 1.

Conclusion

Nitroglycerin, chosen for controlled hypotension to reduce hemorrhage in the surgical field during nasal surgery, was shown to cause more pronounced hypotension and reflex tachycardia due to endothelial dysfunction linked to nicotine in patients who smoke. Despite lower pressure values in the smoking group, the negative effects of nicotine on platelet functions combined with similar effects of nitroglycerin to increase bleeding amounts.

Ex vivo platelet morphology assessment of chronic myeloid leukemia patients before and after Imatinib treatment

Chronic myeloid leukemia (CML) is a myeloproliferative disease and the first line treatment is through the administration of Imatinib, a first generation tyrosine kinase inhibitor. Thrombocytosis and bleeding irregularities are common in CML, however, the morphological variations in CML patients' platelets are not well documented. In this study, ex vivo platelet morphology of control participants, as well as CML patients were assessed before and after Imatinib treatment. The topographical and structural morphology of platelets were determined via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Qualitative data of SEM and TEM revealed that CML patient's platelets were prone to aggregation and coagulation at time of diagnosis; the samples that were not aggregated at time of diagnosis showed typical discoid shaped platelets, which was comparable to control participants' platelets. TEM results of CML patients' platelets at diagnosis showed that internal granular constituents including dense bodies were decreased in comparison to control participants. In all CML patients, platelets appeared activated after 6 months of treatment with Imatinib with membrane structure abnormalities and constituent variations. Research to date has primarily focused on the effects of CML on leukocyte populations, however, the results of the current study implicate the impact of CML pathogenesis on platelets, seemingly as a result of alterations in normal hematopoiesis. In addition, the impact of Imatinib treatment on platelet morphology was also established, indicating an increase in platelet activation. Recognizing and understanding the impact of CML disease progression on platelets is of importance to aid improved patient treatment.

Platelet Function, Role in Thrombosis, Inflammation, and Consequences in Chronic Myeloproliferative Disorders

Platelets are conventionally defined as playing a vital role in homeostasis and thrombosis. This role has over the years transformed as knowledge regarding platelets has expanded to include inflammation, cancer progression, and metastasis. Upon platelet activation and subsequent aggregation, platelets release a host of various factors, including numerous pro-inflammatory factors. These pro-inflammatory factors are recruiters and activators of leukocytes, aiding in platelets’ immune regulating function and inflammatory function. These various platelet functions are interrelated; activation of the inflammatory function results in thrombosis and, moreover, in various disease conditions, can result in worsened or chronic pathogenesis, including cancer. The role and contribution of platelets in a multitude of pathophysiological events during hemostasis, thrombosis, inflammation, cancer progression, and metastasis is an important focus for ongoing research. Platelet activation as discussed here is present in all platelet functionalities and can result in a multitude of factors and signaling pathways being activated. The cross-talk between inflammation, cancer, and platelets is therefore an ideal target for research and treatment strategies through antiplatelet therapy. Despite the knowledge implicating platelets in these mentioned processes, there is, nevertheless, limited literature available on the involvement and impact of platelets in many diseases, including myeloproliferative neoplasms. The extensive role platelets play in the processes discussed here is irrefutable, yet we do not fully understand the complete interrelation and extent of these processes.

The Effect of Tobacco Smoking on Adverse Events Following Adult Complex Deformity Surgery: Analysis of 270 Patients From the Prospective, Multicenter Scoli-RISK-1 Study

STUDY DESIGN

Post-hoc analysis of a prospective, multicenter cohort study.

OBJECTIVE

To analyze the impact of smoking on rates of postoperative adverse events (AEs) in patients undergoing high-risk adult spine deformity surgery.

SUMMARY OF BACKGROUND DATA

Smoking is a known predictor of medical complications after adult deformity surgery, but the effect on complications, implant failure and other AEs has not been adequately described in prospective studies.

METHODS

Twenty-six patients with a history of current smoking were identified out of the 272 patients enrolled in the SCOLI-RISK-1 study who underwent complex adult spinal deformity surgery at 15 centers, with 2-year follow-up. The outcomes and incidence of AEs in these patients were compared to the nonsmoking cohort (n = 244) using univariate analysis, with additional multivariate regression to adjust for the effect of patient demographics, complexity of surgery, and other confounders.

RESULTS

The number of levels and complexity of surgery in both cohorts were comparable. In the univariate analysis, the rates of implant failure were almost double (odds ratio 2.28 [0.75-6.18]) in smoking group (n = 7; 26.9%)) that observed in the nonsmoking group (n = 34; 13.9%), but this was not statistically significant (P = 0.088). Surgery-related excessive bleeding (>4 L) was significantly higher in the smoking group (n = 5 vs. n = 9; 19.2% vs. 3.7%; OR 6.22[1.48 - 22.75]; P = 0.006). Wound infection rates and respiratory complications were similar in both groups. In the multivariate analysis, the smoking group demonstrated a higher incidence of any surgery-related AEs over 2 years (n = 13 vs. n = 95; 50.0% vs. 38.9%; OR 2.12 [0.88-5.09]) (P = 0.094).

CONCLUSION

In this secondary analysis of patients from the SCOLI-RISK-1 study, a history of smoking significantly increased the risk of excessive intraoperative bleeding and nonsignificantly increased the rate of implant failure or surgery-related AEs over 2 years. The authors therefore advocate a smoking cessation program in patients undergoing complex adult spine deformity surgery.

LEVEL OF EVIDENCE

2.

Red blood cells donated by smokers: A pilot investigation of recipient transfusion outcomes

BACKGROUND

Current regulations do not require blood collection facilities to ask donors about cigarette smoking, and the prevalence of nicotine and its metabolites in blood products is not well established. Although smokers have higher hemoglobin (Hb) levels, smoking may adversely affect the quality of donated red blood cells through higher carboxyhemoglobin (COHb) content and premature hemolysis.

STUDY DESIGN AND METHODS

Red blood cell (RBC) unit segments from 100 unique donors were tested for nicotine and its metabolite cotinine by mass spectrometry and for COHb spectrophotometrically. Outcomes were evaluated retrospectively in adult non-bleeding patients receiving single RBC units.

RESULTS

Thirteen of 100 RBC segments (13%) were positive for cotinine at levels consistent with current smoking (> 10 ng/mL). The cotinine positive RBCs showed significantly greater COHb content compared to cotinine negative units (median 3.0% vs. 0.8%, p = 0.007). For patients transfused cotinine-positive units, there was no significant change in their vital signs following transfusion and no transfusion reactions were observed. However, patients transfused cotinine-positive units showed significantly reduced hematocrit and hemoglobin increments (median +1.2% and +0.4 g/dL) following transfusion compared to patients receiving cotinine negative units (median +3.6% and +1.4 g/dL) (p = 0.014).

CONCLUSION

Thirteen percent of RBC units tested positive for cotinine at levels consistent with active smoking, accordant with the estimated national smoking rate of 15.5%. Cotinine-positive RBC units had greater COHb content and showed reduced hematocrit and hemoglobin increments following transfusion. These preliminary results should be validated in a larger cohort.

Incidence and Risk Factors of Postoperative Hematoma Requiring Reoperation in Single-level Lumbar Fusion Surgery

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

The purpose of the present study was to examine the incidence and risk factors for postoperative hematoma requiring reoperation in patients undergoing single-level lumbar fusion surgery.

SUMMARY OF BACKGROUND DATA

Postoperative hematoma can cause devastating neurological consequences after spine surgery. Risk factors for hematoma in specific spine procedures have not been well established.

METHODS

A cohort of patients undergoing single-level lumbar fusion surgery was constructed from the 2012 to 2013 American College of Surgeons National Surgical Quality Improvement Program dataset using Current Procedural Terminology codes (22533, 22558, 22612, 22630, and 22633). In cases requiring reoperation within 30 days after initial surgery, postoperative hematoma was identified using the ICD-9 code 998.1. Risk factors for postoperative hematoma were assessed with logistic regression modeling.

RESULTS

Of 5280 patients undergoing single-level lumbar fusion surgery, 27 patients (0.5%) developed a postoperative hematoma requiring reoperation for hematoma evacuation. A heightened incidence of postoperative hematoma was found in patients who were smokers (1.0% vs. 0.4% for nonsmokers, P = 0.016) or who had a diagnosis of bleeding disorder (3.8% vs. 0.5% for those without bleeding disorder, P = 0.007). Multivariate logistic regression analysis indicated that the adjusted odds ratios for postoperative hematoma associated with smoking and bleeding disorder were 3.34 (95% confidence interval, 1.15-9.71) and 10.2 (95% confidence interval, 1.9-54.8), respectively.

CONCLUSION

Smoking and bleeding disorder appear to be major risk factors for postoperative hematoma requiring reoperation after single-level lumbar fusion surgery. Intervention programs targeting patients with these risk factors are needed to reduce their excess risk of postoperative hematoma.

LEVEL OF EVIDENCE

3.

Effect of cigarette smoke on monocyte procoagulant activity: Focus on platelet-derived brain-derived neurotrophic factor (BDNF)

Cigarette smoke (CS) activates platelets, promotes vascular dysfunction, and enhances Tissue Factor (TF) expression in blood monocytes favoring pro-thrombotic states. Brain-derived neurotrophic factor (BDNF), a member of the family of neurotrophins involved in survival, growth, and maturation of neurons, is released by activated platelets (APLTs) and plays a role in the cardiovascular system. The effect of CS on circulating levels of BDNF is controversial and the function of circulating BDNF in atherothrombosis is not fully understood. Here, we have shown that human platelets, treated with an aqueous extract of CS (CSE), released BDNF in a dose-dependent manner. In addition, incubation of human monocytes with BDNF or with the supernatant of platelets activated with CSE increased TF activity by a Tropomyosin receptor kinase B (TrkB)-dependent mechanism. Finally, comparing serum and plasma samples of 12 male never smokers (NS) and 29 male active smokers (AS) we observed a significant increase in microparticle-associated TF activity (MP-TF) as well as BDNF in AS, while in serum, BDNF behaved oppositely. Taken together these findings suggest that platelet-derived BDNF is involved in the regulation of TF activity and that CS plays a role in this pathway by favoring a pro-atherothrombotic state.

Smoking is Associated with Increased Blood Loss and Transfusion Use After Lumbar Spinal Surgery

BACKGROUND

Little is known about the association between smoking and intraoperative blood loss and perioperative transfusion use in patients undergoing spinal surgery. However, we found that although many of the common complications and deleterious effects of smoking on surgical patients had been well documented, the aspect of blood loss seemingly had been overlooked despite data reported in nonorthopaedic sources to suggest a possible connection.

QUESTIONS/PURPOSES

We asked: (1) Is smoking associated with increased estimated blood loss during surgery in patients undergoing lumbar spine surgery? (2) Is smoking associated with increased perioperative transfusion usage?

METHODS

Between 2005 and 2009, 581 lumbar decompression procedures (with or without fusion) were performed at one academic spine center. Of those, 559 (96%) had sufficient chart documentation to categorize patients by smoking status, necessary intra- and postoperative data to allow analysis with respect to bleeding and transfusion-related endpoints, and who did not meet exclusion criteria. Exclusion criteria included: patients whose smoking status did not fit in our two categories, patients with underlying coagulopathy, patients receiving anticoagulants (including aspirin and platelet inhibitors), history of hepatic disease, history of platelet disorder or other blood dyscrasias, and patient or family history of any other known bleeding disorder. Smoking history in packs per day was obtained for all subjects. We defined someone as a smoker if the patient reported smoking up until the day of their surgical procedure; nonsmokers were patients who quit smoking at least 6 weeks before surgery or had no history of smoking. We used a binomial grouping for whether patients did or did not receive a transfusion perioperatively. Age, sex, number of levels of discectomies, number of levels decompressed, number of levels fused, and use of instrumentation were recorded. The same approaches were used for transfusions in all patients regardless of smoking history; decisions were made in consultation between the surgeon and the anesthesia team. Absolute indications for transfusion postoperatively were: a hemoglobin less than 7 g/dL, continued symptoms of dizziness, tachycardia, decreased exertional tolerance, or hypotension that failed to respond to fluid resuscitation. Multiple linear regression analyses correcting for the above variables were performed to determine associations with intraoperative blood loss, while logistic regression was used to analyze perioperative transfusion use.

RESULTS

After controlling for potentially relevant confounding variables noted earlier, we found smokers had increased estimated blood loss compared with nonsmokers (mean, 328 mL more for each pack per day smoked; 95% CI, 249-407 mL; p < 0.001). We also found that again correcting for confounders, smokers had increased perioperative transfusion use compared with nonsmokers (odds ratio, 13.8; 95% CI, 4.59-42.52).

CONCLUSIONS

Smoking is associated with increased estimated surgical blood loss and transfusion use in patients undergoing lumbar spine surgery. Patients who smoke should be counseled regarding these risks and on smoking cessation before undergoing lumbar surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Cardiovascular Effects of Exposure to Cigarette Smoke and Electronic Cigarettes: Clinical Perspectives From the Prevention of Cardiovascular Disease Section Leadership Council and Early Career Councils of the American College of Cardiology

Cardiovascular morbidity and mortality as a result of inhaled tobacco products continues to be a global healthcare crisis, particularly in low- and middle-income nations lacking the infrastructure to develop and implement effective public health policies limiting tobacco use. Following initiation of public awareness campaigns 50 years ago in the United States, considerable success has been achieved in reducing the prevalence of cigarette smoking and exposure to secondhand smoke. However, there has been a slowing of cessation rates in the United States during recent years, possibly caused by high residual addiction or fatigue from cessation messaging. Furthermore, tobacco products have continued to evolve faster than the scientific understanding of their biological effects. This review considers selected updates on the genetics and epigenetics of smoking behavior and associated cardiovascular risk, mechanisms of atherogenesis and thrombosis, clinical effects of smoking and benefits of cessation, and potential impact of electronic cigarettes on cardiovascular health.

Transient ischemic attack during smoking: The thrombotic state of erythrocytes and platelets illustrated visually

Transient ischemic attack (TIA) is an important predictor of future ischemic events, including stroke. Due to the typically brief period of neurologic dysfunction, patients often overlook the importance of reporting a TIA. We have recently shown that platelet activation plays an important role in TIA pathology. In a similar vein, smoking is associated with a hypercoagulable state and is also one of the important risk factors for stroke. Here we present an interesting case where a 61-year-old male, with hypercholesterolemia, and a previous heart valve replacement, developed a TIA 5 months after he started smoking. Subsequent to the event, Warfarin dosage was monitored monthly using the international normalized ratio (INR). We compared erythrocyte and platelet morphology of healthy individuals, that of smokers, individuals who had a diagnosed TIA (without smoking), and the patient. The erythrocytes from the case study are ultrastructurally similar to that of a smoker, while his platelets are similar to that of smokers and TIA patients who do not smoke. We conclude that smoking exacerbated the chronic inflammation induced by hypercholesterolemia, causing changes in his erythrocyte morphology and platelet activation, and suggest that ultrastructure here explains the clinical manifestations of the thrombotic state of this patient.

Viscoelasticity and Ultrastructure in Coagulation and Inflammation: Two Diverse Techniques, One Conclusion

The process of blood clotting has been studied for centuries. A synopsis of current knowledge pertaining to haemostasis and the blood components, including platelets and fibrin networks which are closely involved in coagulation, are discussed. Special emphasis is placed on tissue factor (TF), calcium and thrombin since these components have been implicated in both the coagulation process and inflammation. Analysis of platelets and fibrin morphology indicate that calcium, tissue factor and thrombin at concentrations used during viscoelastic analysis (with thromboelastography or TEG) bring about alterations in platelet and fibrin network ultrastructure, which is similar to that seen in inflammation. Scanning electron microscopy indicated that, when investigating platelet structure in disease, addition of TF, calcium or thrombin will mask disease-induced alterations associated with platelet activation. Therefore, washed platelets without any additives is preferred for morphological analysis. Furthermore, morphological and viscoelastic analysis confirmed that thrombin activation is the preferred method of fibrin activation when investigating fibrin network ultrastructure.

Eryptosis as a marker of Parkinson's disease

A major trend in recent Parkinson's disease (PD) research is the investigation of biological markers that could help in identifying at-risk individuals or to track disease progression and response to therapies. Central to this is the knowledge that inflammation is a known hallmark of PD and of many other degenerative diseases. In the current work, we focus on inflammatory signalling in PD, using a systems approach that allows us to look at the disease in a more holistic way. We discuss cyclooxygenases, prostaglandins, thromboxanes and also iron in PD. These particular signalling molecules are involved in PD pathophysiology, but are also very important in an aberrant coagulation/hematology system. We present and discuss a hypothesis regarding the possible interaction of these aberrant signalling molecules implicated in PD, and suggest that these molecules may affect the erythrocytes of PD patients. This would be observable as changes in the morphology of the RBCs and of PD patients relative to healthy controls. We then show that the RBCs of PD patients are indeed rather dramatically deranged in their morphology, exhibiting eryptosis (a kind of programmed cell death). This morphological indicator may have useful diagnostic and prognostic significance.

Comparison of platelet ultrastructure and elastic properties in thrombo-embolic ischemic stroke and smoking using atomic force and scanning electron microscopy

Thrombo-embolic ischemic stroke is a serious and debilitating disease, and it remains the second most common cause of death worldwide. Tobacco smoke exposure continues to be responsible for preventable deaths around the world, and is a major risk factor for stroke. Platelets play a fundamental role in clotting, and their pathophysiological functioning is present in smokers and stroke patients, resulting in a pro-thrombotic state. In the current manuscript, atomic force and scanning electron microscopy were used to compare the platelets of smokers, stroke patients and healthy individuals. Results showed that the elastic modulus of stroke platelets is decreased by up to 40%, whereas there is an elasticity decrease of up to 20% in smokers' platelets. This indicates a biophysical alteration of the platelets. Ultrastructurally, both the stroke patients and smokers' platelets are more activated than the healthy control group, with prominent cytoskeletal rearrangement involved; but to a more severe extent in the stroke group than in the smokers. Importantly, this is a confirmation of the extent of smoking as risk factor for stroke. We conclude by suggesting that the combined AFM and SEM analyses of platelets might give valuable information about the disease status of patients. Efficacy of treatment regimes on the integrity, cell shape, roughness and health status of platelets may be tracked, as this cell's health status is crucial in the over-activated coagulation system of conditions like stroke.

Albumin stabilizes fibrin fiber ultrastructure in low serum albumin type 2 diabetes

Serum albumin is an essential plasma protein that serves an important function in maintaining osmotic pressure. Low levels of this protein are associated with the kidney failure and hemodialysis that are often seen in diabetic patients who are at high risk of thrombotic events. In diabetes, fibrin fiber nets are changed to form dense matted deposits (DMDs, or parafibrin). Here the authors investigate whether parafibrin is also present in diagnosed low-albumin diabetes patients and whether the addition of human albumin to plasma from low-albumin diabetes type 2 individuals may change the architecture of the fibrin nets. The authors show that the addition of albumin to plasma of low-albumin diabetes patients progressively caused the DMDs typically found in these patients to revert back to ultrastructure typically seen in healthy individuals. This disease has an extremely complicated pathophysiology and thus cannot be considered as a simple condition. This study shows that serum albumin levels may play an important role in the structure of fibrin fibrils, making them more susceptible to the fibrinolytic degradation and elimination from the circulation.