The acute effect of cigarette smoking on the respiratory function and FENO production among young smokers.

INTRODUCTION: Smoking is known to have a long-term impact on lung function; however, the acute physiological response of smoking a single cigarette and the influential role of pack years and cigarettes per day on pulmonary indices remains an area of interest, especially among young smokers. METHODS: 50 naive smokers (ages: 18-26, 24 males: mean pack years 3.8) participated in this experimental study. Respiratory resistance (R), reactance (X), and impedance (Z) were assessed through impulse oscillometry. The participants' fraction of exhaled nitric oxide (FENO) was measured. All tests were performed immediately before and after smoking one single cigarette. RESULTS: Smoking a single cigarette was found to immediately increase airway impedance (Z 5 Hz) by 0.024 kPa/(L/s) (P = .002), airway resistance at R 5 Hz, R 10 Hz, and R 20 Hz by 0.024 kPa/(L/s)(P < .001), 0.016 kPa/(L/s)(P = .019), and 0.023 kPa/(L/s) (P = .007), respectively, after adjusting for BMI, age, gender, and pack years. FENO concentrations also decreased from 11.70 ppb to 9.85 ppb, P < .001. Sensitivity analyses indicated that the participants' number of pack years and cigarettes per day influenced pulmonary reactance at 10 Hz and 20 Hz, however only at baseline with these differences found to disappear immediately after smoking. CONCLUSIONS: The present study indicates that the consumption of a single cigarette may alter lung mechanics and FENO production among young smokers. Further research is needed to assess the mechanisms and washout period after which these parameters return to normal.

Acute pulmonary effects of sidestream secondhand smoke at simulated car concentrations.

1. Exposure to secondhand smoke (SHS) can occur in many places; however, regulations banning smoking may reduce the sources of exposure to SHS to personal areas such as the family car, a source of brief but potently intense exposure. 2. Fifteen non-smoking volunteers were exposed to sidestream SHS concentrations of 5000 µg/m(3), within a simulated car setting. The Fraction of Exhaled Nitric Oxide (FeNO) was calculated, dynamic flow volumes were assessed through spirometry; while airway impedance (Z), resistance (R), and reactance (X) was assessed through impulse oscillometry before and after exposure. 3. Exposure to sidestream SHS within this experimental condition did not affect dynamic flow volumes, however FENO decreased from 15.34 ppb to 11.15 ppb, (p < 0.001). Increases in airway resistance at R5Hz by 0.114 kPa/(L/s) (p = 0.002), at R10Hz by 0.093[kPa/(L/s)] (p = 0.006) and at R20Hz by 0.093[kPa/(L/s)] (p = 0.008) were noted. Correspondingly overall peripheral and central airway resistance was also found to increase by 40% (by 0.083 kPa/(L/s), p = 0.038) and 25% (by 0.045 kPa/(L/s), p = 0.047) respectively. 4. Brief but elevated exposure to sidestream SHS can alter airway resistance, and impedance indicating a potential additional mechanistic pathway between exposure to SHS and the development of respiratory disease. Further research is needed to verify these pilot results.

Physiologic effects of stress dose corticosteroids in in-hospital cardiac arrest (CORTICA): A randomized clinical trial.

Aim: Postresuscitation hemodynamics are associated with hospital mortality/functional outcome. We sought to determine whether low-dose steroids started during and continued after cardiopulmonary resuscitation (CPR) affect postresuscitation hemodynamics and other physiological variables in vasopressor-requiring, in-hospital cardiac arrest. Methods: We conducted a two-center, randomized, double-blind trial of patients with adrenaline (epinephrine)-requiring cardiac arrest. Patients were randomized to receive either methylprednisolone 40 mg (steroids group) or normal saline-placebo (control group) during the first CPR cycle post-enrollment. Postresuscitation shock was treated with hydrocortisone 240 mg daily for 7 days maximum and gradual taper (steroids group), or saline-placebo (control group). Primary outcomes were arterial pressure and central-venous oxygen saturation (ScvO2) within 72 hours post-ROSC. Results: Eighty nine of 98 controls and 80 of 86 steroids group patients with ROSC were treated as randomized. Primary outcome data were collected from 100 patients with ROSC (control, n = 54; steroids, n = 46). In intention-to-treat mixed-model analyses, there was no significant effect of group on arterial pressure, marginal mean (95% confidence interval) for mean arterial pressure, steroids vs. control: 74 (68-80) vs. 72 (66-79) mmHg] and ScvO2 [71 (68-75)% vs. 69 (65-73)%], cardiac index [2.8 (2.5-3.1) vs. 2.9 (2.5-3.2) L/min/m2], and serum cytokine concentrations [e.g. interleukin-6, 89.1 (42.8-133.9) vs. 75.7 (52.1-152.3) pg/mL] determined within 72 hours post-ROSC (P = 0.12-0.86). There was no between-group difference in body temperature, echocardiographic variables, prefrontal blood flow index/cerebral autoregulation, organ failure-free days, and hazard for poor in-hospital/functional outcome, and adverse events (P = 0.08->0.99). Conclusions: Our results do not support the use of low-dose corticosteroids in in-hospital cardiac arrest.Trial Registration:ClinicalTrials.gov number: NCT02790788 ( https://www.clinicaltrials.gov ).

Statins and cancer.

Statins have pleiotropic properties and might exert an effect even in the field of cancer. Statins competitively inhibit 3-hydroxy-3-methylglutaryl coenzyme (HMG-CoA) reductase, the major rate-limiting enzyme that controls the conversion of HMG-CoA to mevalonic acid. Specifically, inhibition of HMG-CoA reductase by statins has been proved to prevent the synthesis of mevalonic acid, a precursor of non-steroidal isoprenoids, which are lipid attachment molecules for small G proteins, such as Ras, Rho and Rac. Thus, statins may inhibit the synthesis of isoprenoids and thereby suppress the activation of small G proteins. In addition, statins exert pro-apoptotic, anti-angiogenic, and immunomodulatory effects, which may prevent cancer growth. Statins may inhibit the growth of a variety of cancer cell types, including breast, gastric, pancreatic, and prostate carcinoma, neuroblastoma, melanoma, mesothelioma and acute myeloid leukemia cells. They exert pro-apoptotic effects in a wide range of cancer cell lines, but with many differences in the sensitivity to statin-induced cell death among different cancer cell types. Regarding anti-angiogenic effects, multiple statin effects on blood vessel formation by inhibition of angiogenesis through down-regulation of pro-angiogenic factors, such as vascular endothelial growth factor, inhibition of endothelial cell proliferation and inhibition of adhesion to extracellular matrix by blocking intercellular adhesion molecules have been suggested. The molecular mechanisms of statin immunomodulation often implicate multiple pathways, regarding the regulation of genes encoding key molecules, which are involved in antigen presentation and subsequent immunomodulation. Another mechanism involves the down-regulation of the nuclear factor-kappa-B, which is responsible for the transcription of many genes involved in immunologic mechanisms, such as interferon-inducible protein-10, monocyte chemo-attractant protein 1 and cyclooxygenase-2. Statins have been associated with a significantly lower risk of breast, colorectal, ovarian, pancreatic, lung cancers and lymphoma in several observational studies. On the other hand, other studies, including meta-analyses have raised concerns about the safety of statins among elderly patients. A recent study upon the relationship between statin use (prior to cancer diagnosis) and cancer-related mortality in the entire Danish population from 1995-2009 in adults > 40 years of age has been conducted. As compared to statin non-users, patients using statins prior to cancer diagnosis were 15% less likely to die from any cause or cancer specifically. Further investigation is needed to elaborate on their mode of action as well as their true significance on cancer prevention and perhaps as an adjuvant to cancer chemotherapy.

Short-term pulmonary effects of using an electronic cigarette: impact on respiratory flow resistance, impedance, and exhaled nitric oxide.

BACKGROUND: Debate exists over the scientific evidence for claims that electronic cigarettes (e-cigarettes) have no health-related ramifications. This study aimed to assess whether using an e-cigarette for 5 min has an impact on the pulmonary function tests and fraction of exhaled nitric oxide (Feno) of healthy adult smokers. METHODS: Thirty healthy smokers (aged 19-56 years, 14 men) participated in this laboratory-based experimental vs control group study. Ab lib use of an e-cigarette for 5 min with the cartridge included (experimental group, n = 30) or removed from the device (control group, n = 10) was assessed. RESULTS: Using an e-cigarette for 5 min led to an immediate decrease in Feno within the experimental group by 2.14 ppb (P = .005) but not in the control group (P = .859). Total respiratory impedance at 5 Hz in the experimental group was found to also increase by 0.033 kPa/(L/s) (P < .001), and flow respiratory resistance at 5 Hz, 10 Hz, and 20 Hz also statistically increased. Regression analyses controlling for baseline measurements indicated a statistically significant decrease in Feno and an increase in impedance by 0.04 kPa/(L/s) (P = .003), respiratory resistance at 5 Hz by 0.04 kPa/(L/s) (P = .003), at 10 Hz by 0.034 kPa/(L/s) (P = .008), at 20 Hz by 0.043 kPa/(L/s) (P = .007), and overall peripheral airway resistance (ß, 0.042 kPa/[L/s]; P = .024), after using an e-cigarette. CONCLUSIONS: e-Cigarettes assessed in the context of this study were found to have immediate adverse physiologic effects after short-term use that are similar to some of the effects seen with tobacco smoking; however, the long-term health effects of e-cigarette use are unknown but potentially adverse and worthy of further investigation.